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CHEMICAL  ESSAYS, 


PRINCIPALLY    RELATING    TO. 


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THE  ARTS  AND  MANUFACTURES 


OF 


THE  BRITISH  DOMINIONS. 


Bt  SAMUEL  PARKE S,  F.L.S.  M.R.L  F.S.A.  Ed. 

Member  of  the  Royal  Asiatic  Society  of  Great  Britain  and  Ireland, 

Fellow  of  the  Creoloeical  and  Astronomical  Societies  of  London. 

And  of  the  Wemerian,  Horticultural  and  Highland  Societies  of  SootUnd; 

Member  of  the  American  Philosopnical  Society,  and 

Master  of  Arts  of  Yale  College,  Connecticut : 

Member  of  the  Jmperial  Natural  I^storr  Society  or  Moscow, 

The  Academy  of  Sciences,  Arts  and  Belles  Lettre^  at  Dijon, 

And  the  Academy  of  Medicine  at  BCarseilles ; 

Honorary  Member  of  the  Rojral  Geolc^cal  Society  of  Cornwall, 

The  Antiquarian  Society  of  Newcastle  upon  Tyne, 

The  Agricultural  Societies  of  Philadelphia  and  Massachusetts,  and 

The  Society  for  the  Promotion  of  National  industry  and  the  Arts  at  Lisbon  ; 

Corresponding  Member  of 
The  Literary  and  Philosophical  Society  of  Manchester ;  the  Academy 

of  Natural  Sciences  in  Philadelpnia ;  the  Philomathique 
Society  of  Paris ;  and  the  Imperial  Agricultural,  and  Physico- Medical 

Societies  of  luoscow,  Stc. 

AUTHOR    OF 
THE  CHEMICAL  CATECHISM,  THE  RUDIMENTS  OF  CHEMISTRYr 

cj-c    ^c. 


THE  SECOND  EDITION, 

Greatly  enlarged,  and  illutirated  unth  twenty-four  Plates  of  Machinery 

and  Chemical  Apparatus, 


VOL.  II. 

Hontion: 

PRINTED    FOR    THE    AUTHOR; 

AND   PUBLISHED   BY   BALDWIN,    CRADOCK,    AND   JOY, 

PATERNOSTER- ROW. 

1823. 


Cnterrti  at  dtattonrrs'  (^alU 


PRINTED  BT  R.  TAYLOR,  8H0K-LANK,  LONDON. 


DESCRIPTION  OF  THE  PLATES 


THE  SECOND  VOLUME. 


ApPAHATUS  for  mtiking  charcoal  and  distilling  pyro ligneous 


ELCid. 


:.l   1 


;tion  of  a  charcoal  cylinder  when  fixed 
B  cut  lengthwise  through  the  middle. 


Siresenta  a 
urnace.     1 
to  show  the  internal  v 

Fig.  2  is  8  contrary  section  of  tlie  same  cylinder,  the  end,  or 
front  wall  being  in  thi»<  case  taken  away  to  show  how  (he  fire 
plays  round  it  before  il  passes  off  by  the  chimney. 

Fig.  3  is  an  elevation  of  the  building  which  incloses  a  cylin- 
der when  properly  fixed,  together  with  the  fire-place,  the  tube* 
to  carry  off  the  acid  and  gas,  the  wine  casks  to  receive  pyro- 
1  igneous  acid,  &c.  complete. 

Fig.  4.  The  outer  shutter,  to  contain  the  stopping  or  luting 
which  makes  the  cylinder  air-tiglit  during  the  operation  of  di- 
stilling the  acid  and  charring  the  wood. 

Fig.  5.  The  inner  shutter,  or  stopper  to  prevent  the  stopping 
from  gelling  among  the  charcoal. 

PLATE  XVI. 

This  drawing  is  the  representation  of  a  reverberatory  furnace 
for  preparing  alkalies.  The  peculiar  advantage  of  this  furnace 
in  preference  to  the  one  described  in  Plate  XVII.  consists  in  the 
arcn  by  which  it  b  covered.  It  will  be  observed  that  this  arch 
springs  from  the  ground,  instead  of  from  the  floor  of  the  oven 
which  is  usual ;  and  this  has  the  effect  of  binding  the  brick- 
work together  much  better  than  it  can  be  done  by  bands  of  iron 
or  by  any  other  expedient.   When  the  abutments  are  good,  and 


1 


VI  DESCRIPTION  OF  THE  PLATES 

the  arch  properly  loaded,  such  a  furnace  will  endure  much 
longer  than  any  of  those  on  the  usual  construction.  The  whole 
is  drawn  to  a  scale  of  \  of  an  inch  to  a  foot,  and  the  separate 
parts  may  be  thus  described : 

A  is  the  door  by  which  the  oven  is  charged. 

BB  the  bridge  which  divides  the  oven  from  the  fire-place.  It 
is  of  a  considerable  thickness,  and  measures  9  inches  from  the 
top  to  the  floor  of  the  oven. 

C  C  the  ash-pit. 

D  an  iron  damper  for  regulating  the  draught  of  the  fire-place. 

£  is  the  passage  from  the  oven  to  the  chimney. 

G  is  the  floor  of  the  oven,  which  should  be  paved  with  the  best 
fire-bricks  set  on  edge,  or  covered  with  a  thick  plate  of  iron. 
The  latter  mode  is  the  best,  when  it  is  intended  to  be  employed 
for  decomposing  the  sulphates  of  soda  or  potash. 

H  is  the  fire-place  closed  by  an  iron  hopper  as  described  at 
page  158,  vol.  i. 

I  the  fire  bars  of  the  same  construction  as  those  mentioned  in 
describing  Plate  XVII. 

K  K  K  the  main  arch  which  covers  the  whole  of  the  furnace. 
The  part  below  the  floor  of  the  oven  may  be  built  with  good 
stock -bricks ;  but  those  parts  which  are  within  reach  of  the  fire 
must  be  composed  of  the  best  fire-bricks. 

L  is  a  line  upon  the  brick-work  of  the  elevation,  which  has 
been  engraved  to  show  the  altitude  of  the  oven -floor. 

PLATE  XVII. 

The  elevation  and  plan  of  a  reverberatory  furnace  on  an 
improved  construction.  The  separate  parts  may  be  thus  de- 
scribed: 

A  is  the  door  by  which  the  oven  is  charged,  the  size  of  which 
may  with  convenience  be  9  indies  by  12  inches. ' 

JB  B  B  are  three  strong  iron  bands  which  go  on  each  side  of 
the  furnace.  These  are  fastened  together  by  cross  bars  of  iron 
which  go  through  the  brick- work  of  the  furnace,  and  over  the 
top  of  it,  and  are  bound  tight  against  the  walls  by  screws  and 
bars,  as  shown  in  the  engraving. 

C  the  ash-pic 

D  an  iron  damper  which  runs  within  a  groove  in  the  brick- 
work of  the  chimney,  to  regulate  the  draught  or  entirely  stop  it 
at  deatore. 

fe  the  pasaage  from  the  oven  to  the  chimney. 

F  is  a  faint  line  On  the  wall  of  the  elevation  to  show  how  the 
ardi  of  Che  roof  lessens  in  height  as  it  approaches^  the  chnnney. 
This  is  designed  for  throwing  the  flame  more  down  upon  the 


IN  THE  SECOND  VOLUME. 


Vll 


tnatrrials  before  it  enters  the  chimney,  and  has  the  effect  of  ren- 
dering the  temperature  of  the  oven  the  same  in  all  its  parts. 
G  is  the  floor  of  the  oven,  4  feet  long  and  2  feet  2J  inches 

H  is  the  fire-place  with  an  iron  hopper  such  as  is  described  at 
page  158,  vol,  i. 

1  are  the  fire  bars,  with  their  ends  projecting,  as  shown  in  the 
elevation,  for  the  convenience  of  drawing  them  easily  whenever 
it  may  be  necessary  either  to  cool  the  furnace  or  take  out  the 
clink^TB.  When  the  bars  of  a  furnace  are  fixed  in  this  manner, 
they  may  be  readily  taken  out  with  a  pair  of  ton^,  and  then 
the  whole  of  the  contents  of  the  fire-place  will  fall  mlo  the  ash- 
pit. 

K  is  the  bridge  which  divides  the  floor  of  the  oven  from  the 
fire-place.  This  should  be  14  inches  thick  ami  (I  inches  high, 
and  built  with  the  best  fire-bricks.  It  is  important  to  build  it 
vrilh  very  clone  joints  and  with  fire  clay  instead  of  mortar,  as  the 
bridge  usually  wants  repair  before  any  other  part  of  the  furnace. 

As  this  drawing  Ls  an  exact  representation  of  a  very  useful 
reverberatory  furnace  which  was  erected  at  my  own  manufac- 
tory, it  may  perhaps  be  acceptable  if  I  annex  the  mea-tures  of 
the  principal  parts,  for  the  guidance  of  those  persons  who  may 
be  desirous  of  constructing  a  similar  Aimace. 

The  whole  length  measured  on  the  outside  is  8  feet,  the 
width  4  feet  2  inches,  and  the  height  from  the  floor  to  the  top 
of  the  covering  4  feet  6  inches.  The  fire-place  17  inches  by 
20  inches,  the  ash-pit  10  inches  wide,  and  2  feet  4  inches  from 
the  ground  to  the  underside  of  the  fire-bars.  The  height  of  the 
oven  from  the  floor  of  it  to  the  underside  of  the  arch  is  1 7  inchea 
at  the  bridge,  and  12  inches  if  measured  at  the  chimney.  The 
measures  of  the  oven  floor,  the  door  and  the  bridge,  have  been 
noticed  before. 

PLATE  XVI H. 

This  plate  contains  a  collection  of  some  of  the  most  useful 
chemical  utensils  which  can  be  made  in  earthenware.  They 
may  thus  be  briefly  described  ; 

A  is  an  earthenware  still  in  two  parts,  with  a  ledge  round  the 
neck  of  the  body  to  hold  lute  or  water,  as  may  he  moat  suitable 
to  the  deration  to  be  performed  in  it. 

B  a  aieve  of  earthenware  in  three  parts.  1  is  the  .sieve  part 
whh  a  groove  round  the  bottom  for  the  convenience  of  adapting 
a  piece  of  muslin  to  it  in  the  usual  way.  2  'm  the  cover  which 
fitK  in  tight  to  prevent  any  dust  escaping  during  its  agitation  j 
ftnd  3  is  the  Tcssel  adapted  to  No.  1 ,  for  receiving  such  parts 


•  •• 


yill  DESCaiPTION  OF  THB  Pf4AT£S 

of  the  powder  to  be  sifted  which  passes  through  the  muslin.  The 
only  advantaces  which  this  utensil  has  oyer  those  in  common 
use  consist  m  its  superior  cleanliness^  nnd  in  die  ease  with 
which  light  powders  may  be  brushed  out  of  it. 
.  C  are  crucibles  both  open  and  covered^ — ^Those  made  with 
Wedgwood's  fire  ware  are  for  some  purposes  preferable  to  any 

D  is  an  aur-tight  jar  with  a  lid  applicable  to  many  useful 
DUrposes.  4  1^  a  ledg^  running  round  the  inside  of  the  jar. 
S.'k,  a  trpujg^h  .round  the  outside  of  the  jar  to  receive  the  lid. 
Wpcn  the  lid  is  pu^  on^  the  trough  is  to  be  filled  with  mercury, 
oil,  water,  or  putty,  in  order  to  make  the  whole  air-tight.  6  is 
the  cover  with  holes  to  receive  tubes  if  necessary,  or  they  may 
be  closed  by  earthen  stoppers. 

E  an  adapting  tube  of  earthenware  nseful  for  many  purposes 
in  at  lal^ratory. 

',  G,.a  galvanic  trough  of  queen's  ware  for  experiments  in  Vol- 
taic,electricity. 

Pa  pneumatic  trough  of  earthenware  with  a  shelf,  &c,  of  the 
iis;ual  construction. 

R  an  earthenware  retort  of  the  usual  form. 

PLATE  XIX. 

I9  the  representation  of  crown  glass  in  its  various  states  from 
the  time  it  is  taken  out  of  the  furnace  until  it  becomes  a  perfect 
circular  sheet  of  window  glass.  The  whole  is  fully  explained 
in  the  Essay,  page  195. 

PLATE  XX. 

'Apparatus  for  the  preparation  of  oxymuriate  of  soda,  oxymu- 
riate  of  magnesia,  &c.  for  the  use  of  calico-printers. 

A  is  the  furnace  for  heating  the  materials  which  furnish  the 
oxymuriatic  gas. 

B  a  cast-iron  vessel  containing  water,  and  forming  a  water- 
bath  for  the  reception  of  the  still  marked  C. 

C  the  body  of^  the  still,  which  should  be  made  of  lead,  and 
properly  adapted  both  in  form  and  size  to  the  cast-iron  water- 
Dafh  in  whicn  it  stands,  d  d  are  water  lutes  for  the  top  of  the 
still  to  drop  into  >  a  convenient  contrivance  for  keeping  the  ap- 
paratua  tight^  and  preventing  the  gas  from  escaping  into  ibe 
atmoflphere. 

E  die  top  or  head  of  the  still,  made  of  lead,  and  sufikienlly 
large  to  allow  of  its  dipping  six  inches  into  the  gutter  of  watei 


IN   THE   SECOND    VOLUME. 


IX 


which  surroundu  the  still.  By  this  simple  contrivance  the  head 
can  be  put  on  or  taken  off  at  pleasure  and  without  difficulty, 
f  f  f  are  pipes  and  lutes  for  the  different  parts  of  the  apparatus. 

G  G  is  a  stirrer,  with  a  square  frame  of  wgad  covered  with 
lead,  attached  to  it  for  the  purpose  of  agitating  the  materials 
within  the  still. 

H  a  bent  funnel  passing  through  the  cover  of  the  atill,  for 
pouriBg  in  the  diluttld  sulphuric  acid. 

I  is  a  small  intermediate  vessel,  partly  filled  with  water,  and 
desired  I41  arrest  any  un combined, muriatic  acid  which  may  oc>    ' 
casionally  arise  from  the  still  during  the  procesn. 

K  represents  the  large  receiver  of  lead  charged  with  the  al- 
kaline sulutioD.  This  prepared  liquor  is  intended  to  receive 
and  absorb  all  the  oxymuriatic  acid  gas  that  comes  from  tha 
Htill,  and  when  sufficiently  saturated  it  is  drawn  off  by  the  cock 
N  for  use. 

L  is  aa  opening  for  filling  the  reservoir,  occasionally  cleans- 


IQgll 


I,  ic. 


M  M  M  the  agitator  for  coastantly  stirring  the  alkaline  solu- 
tion,  and  which  is  necessary  to  promote  the  absorption  of  the 
ga^.  In  large  works  this  is  moved  by  a  poi>er  from  the  steam 
engine 

N  is  the  cock  for  drawing  off  the  finished  liquor  as  mentioned 

The  glass  bottle,  which  appears  in  the  same  plate,  containB 
twa  bubbles  of  glass  ;  one  is  seen  at  bottom,  the  other  tloatinff 
on  the  surface  of  the  liquor.  This  is  recommended  as  a  smaB 
and  useful  apparatus  for  ascertaining  the  specific  gravity  of  the 
oxymuriateof  soda.  Its  advantages,  together  with  the  mode  of  | 
usmg  it,  are  fully  deiicribed  In  Vol.  I.  page  236. 

PLATE  XXI. 

Is  descriptive  of  an  apparatus  far  bleaching  cotton  goods. 
Fig.  I  is  a  section  of  the  bucking  apparatus,  which  may  be  thus 
deacnbed. 

A  is  the  boiler  for  heating  the  alkaline  ]^. 

B  represents  a  *ery  large  wooden  vessel  In  which  the  calicoes 
are  placed. 

C  the  cock  and  pipe,  by  means  of  which  the  hot  lye  is  con- 
veyed upon  the  goods. 

O  Is  a  square  box  designed  for  spreading  tlie  lye  over  the 
calicoes  within  the  vessel  It. 

E  a  pump  for  raising  the  liquor  again  out  of  the  vessel  B, 
from  whence  it  ii  conveyed  by  the  spout  1  back  into  the  boiler  Ai' 

F  Ik  the  funiace  for  heating  the  lye. 


X  DESCRIPTION    OF  THE   PLATES 

G  repreeents  the  false  bottom  of  the  calico  vessel,  full  of  holes 
for  tiie  passage  of  the  lye  when  it  has  run  through  the  goods 
under  operation. 

H  18  a  round  wooden  staff  which  completely  fits  a  hole  at  the 
bottom  of  the  bucking  vessel.  It  is  called  a  duck,  and  is  in- 
tended to  be  pulled  up  whenever  it  is  designed  to  run  off  the 
spent  alkaline  liquor. 

I  is  the  spout  for  conveying  the  liquor  back  to  the  boiler  as 
above  mentioned.  In  some  houses  the  boiler  is  fixed  below  the 
bucking  vessel,  and  the  pump  is  placed  within  the  boiler  as  de- 
scribed in  page  271. 

Fig.  2  is  the  representation  of  a  common  whale-boiler. 

A  IS  a  metallic  boiler  to  be  fixed  in  brick-work,  similar  to 
that  in  fig.  1 . 

B  B  is  the  top  part  of  wood,  called  a  crib,  with  the  bottom 
full  of  holes.  In  this  the  calicoes  are  placed  one  above  another, 
often  amounting  to  many  hundred  pieces  at  one  operation. 

C  is  the  pipe  through  which  the  lyes  boil  up,  and  d  d  is  the 
umbrella  suspended  over  the  pipe  for  the  purpose  of  spreading 
the  lyes  more  effectually  as  they  fall  down  again  upon  the  goods. 

This  apparatus  for  bleaching  possesses  several  advantages. 
The  perforated  wooden  vessel  preserves  the  calicoes  from  be- 
mg  injured  by  coming  in  contact  with  the  boiler,  while  the  pres- 
sure occasioned  by  so  great  a  weight  of  goods  frequently  in- 
creases the  temperature  of  the  lye  by  some  degrees  higher  than 
it  would  acquire  in  an  open  vessel,  and  this  additional  heat  has 
a  powerful  effect  in  bleaching.  By  this  contrivance  there  is  no 
necessity  for  pumping  ;  for,  so  long  as  the  lye  in  the  vessel  A 
actually  boils,  a  constant  stream  will  flow  through  the  pipe  C 
upon  the  goods  in  B,  and  thus  a  perpetual  circulation  may  be 
kept  up  till  the  goods  have  attained  the  desired  whiteness. 

PLATE  XXII. 

Is  descriptive  of  some  peculiar  modes  of  purifying  water.  Figs.  I , 
2,  and  3,  represent  a  glass  apparatus  invented  by  Mr.  Pepys 
for  filtering  small  quantities  of  water  or  other  fluid,  and  may  be 
thus  described. 

Fig.  2  is  a  glass  vessel  with  a  rib  of  tinned  iron  going  round 
the  inside  of  it  near  the  top.  This  rib  has  many  notches  upon 
it,  and  these  are  designed  tor  receiving  a  number  of  small  glass 
rods  as  shown  in  the  drawing,  fig.  1.  These  are  intended  for 
supporting  a  sheet  of  filtering  paper  or  any  other  kind  of  filter 
which  may  be  placed  within  the  jar.  When  this  vessel  is  charged 
with  the  liquor  proposed  to  be  filtrated,  the  cover  d,  which 


IN   THE    SECOND    VOLUME.  xi 

complMcly  fits  it,  ifi  put  on  to  preserve  the  conl«nts  from  dust 
or  other  accidental  iiopurities. 

Fig  3  is  a  glass  vessel  for  receiving  the  fluid  as  it  filtrates 
from  No.  2  ;  therefore,  when  the  apparatus  is  to  be  used,  the 
two  reiwels  are  adapted  to  each  other,  the  parts  marked  a  and 
b  being  accumtely  ground  to  fit;  and  when  put  together,  the 
whole,  except  the  top,  has  the  appearance  as  shown  at  fig.  I. 
This  apparatus  is  sold  by  Messrs.  Knieht,  of  Foster  Lane,  the 
price  U.  Hi.  dd.  to  2 (.  2 J.  each,  according  to  their  size,  &c.     ' 

Fig.  4  is  a  section  of  an  improved  water  reservoir,  fitted  up, 
some  time  a^o  on  a  lai^e  scale  in  Scotland. 

A  is  a  flexible  pipe  of  leather  for  the  purpose  of  allowing  the 
tube  B  to  nlt«r  its  position  according  to  the  height  of  the  water 
within  the  reservoir. 

ft  is  a  metallic  tube  with  a  rose-head,  to  allow  of  the  passage  i 
of  water,  and  yet  prevent  the  entrance  of  impurities  which'  J 
might  accidentally  noat  upon  its  surface.  * 

C  is  a  hollow  ball  of  copper  swimming  on  the  water  for  the  ] 
purpose  of  keeping  the  rose-head  always  near  the  surface,  in  ' 
order  th;it  no  water  may  be  ever  drawn  but  what  comes  fronj  *1 
the  KUrfiK'e  of  the  reservoir. 

D  K  U  a  wooden  trough  for  carrying  off  the  waste  water, 
iinil  preventing  the  overflow  of  the  reservoir. 

F  10  a  large  iron  pi|ie  for  conveying  the  water  from  the  spring,  J 
into  the  trough  G,  firmly  fixed  within  the  reservoir.  "< 

For  the  advantages  of  this  peculiar  construction  of  a  watef  J 
lank.  Me  puges  374  and  .t!)!.  Hic. 

PLATF,  XXIII. 

Tliis  is  a  plao  of  a  convenient  apparatus  first  employed  atH 
Paris  for  the  production  of  sal' ammoniac.  -|^ 

A  A  are  two  furnaces  for  decomposing  common  salt,  each  14*J 
feci  long  by  7  feet  6  inches  wide.  1 

B  B  B  B  arc  pipes  of  bricks,  each  2  feet  wide,  which  goH 
through  the  wall  dividing  the  workshops,  and  conduct  the  vort  ' 
pours  of  muriate  acid  gas  into  the  chamber  C.  ' 

,C  is  the  leaden  chamber  where  the  muriatic  acid  gas  and  tbt 
nmmoniacal  gas  meet  for  the  production  of  muriate  uf  ammo- 
nia, or  sal-ammoniac. 

D  D  are  flues  belonging  to  the  two  furnaces  A  A  for  carrying 
off  the  smoke  of  ihe  lire-pliicw,  Tliese  are  1-1  inches  bv  24 
inches  each,  and  are  carried  up  together,  and  at  hist  united  in- 
to one  chimney  above  ilie  lop  of  the  building, 

K  K  ore  pipes  belonging  to  the  two  furnaces  A.  each  14 
tndics  wide,  connected  with  Ihe  chimneys,  and  designed  for 


Xll  DESCRIPTION   OF  THE    PLATES 

carrying  off  the  muriatic  acid  gas  by  that  conveyance  into  the 
atmospnere,  when  the  furnaces  are  used  for  the  production  of 
soda  without  making  sal-ammoniac. 

F  F  are  cast-iron  plates  or  dampers^  which  open  or  shut  the 
communication  of  the  pipes  £  with  the  chimneys  at  pleasure. 

G  G  are  similar  iron  dampers  which  cut  off  or  determine  the 
passage  of  the  muriatic  acid  gas  into  the  leaden  chamber  C. 

H  is  a  gcound  plan  of  the  kiln  for  burning  the  animal  matters 
designed  to  produce  ammonia. 

J  a  leaden  pipe  to  convey  the  ammoniacal  gas  into  the  cham- 
ber C. 

K  is  a  hde  through  the  arch  or  superior  part  of  the  kiln, 
which  is  desini^d  to  receive  an  eolipile  from  whence  the  steam 
of  hot  water  is  forced  into  the  chamber  C,  at  the  same  moment 
when  the  acid  and  alkaline  gases  are  entering  the  same  recep- 
tade. 

M  the  kiln  chimney. 

N  is  a  flight  of  steps  leading  to  the  ash-pan. 

O  a  pipe  by  which  the  chamber  is  emptied  of  the  liquid  mu- 
riate of  ammonia  when  necessary. 

P  a  flight  of  steps  leading  unaer  the  chamber  C. 

Q  a  door  to  enter  into  the  said  chamber. 

The  peculiar  advantage  of  this  apparatus  is,  that  while  the 
muriatic  acid  gas  is  passing  into  the  chamber  C,  at  that  mo- 
ment another  stream  of  ammoniacal  gas  is  entering  the  same 
chamber  from  the  kiln  H,  which  occasions  a  mutual  conden- 
sation and  prevents  any  loss.  For  further  particulars  see  page 
453  of  this  volume. 

PLATE  XXIV. 

This  plate  contains  two  representations  of  Mr.  Lucas*s  fur« 
nace  for  converting  cast-iron  cutlery  to  good  steel  cutlery. 

Fig.  1  is  a  front  view  of  the  furnace  complete. 

B  B  are  cast-iron  bearers  for  supporting  the  grate  bars. 

D  foundation  wall  below  the  floor  of  the  work -shop  for  sup- 
porting the  interior  of  the  furnace. 

£  £  the  two  fire-places  for  heating  the  furnace.  2  is  the 
dome  or  arch  of  the  mmace.  3  3  the  internal  side  of  the  front 
wall,  in  which  is  an  aperture  4,  by  which  the  workman  enters 
to  place  the  iron  cylinders  holding  the  goods.  This  being  done, 
the  aperture  is  walled  up  as  shown  in  the  engraring,  except 
two  holes  left  in  the  bottom  of  the  wall  marked  5  5. 

H  is  the  chimney  for  conveying  away  the  smoke  of  the  fire- 
places. 

Fig.  2  is  a  perpendicular  section  of  the  same  furnace,  pre- 
aenting  a  side  view  of  its  internal  parts,  and  showing  how  the 


IN    THE   SECOND    VOLUME.  Xlii 

iron  cylinders  whUh  hold  (he  casUiron  culkry  are  exposeii  to 
the  action  or'  the  lire.  The  several  parts  may  be  thus  described  : 

A  kIiows  the  length  and  depth  of  the  ash-pit. 

B  is  tlie  representation  of  one  of  the  grate  bars  at  lult  leng;th, 

E  the  fire-place. 

F  the  opening  for  supplying  the  fire  with  fuel. 

G  a  dotted  line  to  show  the  heiglit  of  the  shop  floor. 

1  I  the  outside  wall  of  the  furnace. 

K  K  the  iron  cylinders  a.<i  they  stand  3  in  height  in  the  fur- 
nace, the  lowermost  of  which  are  raised  a  few  inches  from  the 
platform  by  being  plitced  on  pieces  of  brick,  the  intention  of 
which  is  to  afford  the  hre  access  to  every  part  of  them.  In  de- 
Hcribing  the  other  parts  of  this  furnace  it  may  be  said,  that  2  is 
the  dome  of  the  furnace  ;  4  is  the  temporary  wall  which  is 
built  up  to  close  the  aperture  spoken  of  in  deacribing  the  ele- 
vation 5g.  I,  and  which  in  that  drawing  is  marked  4:  5  is  one 
of  the  holes  left  at  the  bottom  of  the  said  wall ;  7  is  another 
temporary  wall  of  loose  bricks )  G  is  the  space  between  the  two 
walls )  8  the  chimney ;  9  an  opening  in  the  outer  wall,  the 
Mime  width  as  4 ;  10  a  east-iron  bearer  reaching  across  the 
opening  to  support  the  front  of  the  chimney, 

PLATE  III. 

trrAttATV*    FOB    BOIMNO    BV    UBANE    OF    TIIR    CIHCUI4ATION  OP 

HEATED  on.. 

Fig.  I  is  an  elevation  of  the  apparatus,  which  may  be  thus 
described : 

A  is  a  wrought'iron  veasel  for  heating  the  oil,  similar  to  the 
boiler  of  a  steam  engine.  It  is  set  in  brick-work,  with  a  lire 
under  it  of  a  moderate  size,  and  without  any  flues  round  the 
Hides,  so  that  the  whole  action  of  the  lire  is  upon  the  bottom. 
It  is  made  of  an  oblong  fuira,  and  its  length  should  exceed  its 
breadth  as  much  as  the  situation  in  which  it  is  placed  will  allow. 
The  size  depends  upon  the  quantity  of  oil  to  be  heated,  or  the 
liquor  which  is  to  be  evaporated,  and  it  is  observable  that  the 
more  the  surlace  presented  to  the  lire  exceeds  the  evaporating 
Murface,  the  greater  will  be  the  economy  of  fuel,  whale  oil, 
free  from  sediment,  is  found  to  answer  better  than  any  other 
for  this  purpose,  and  the  quantity  necessary  to  be  employed,  is 
merely  sufficient  to  cover  the  bottom  of  the  vessel  to  the  depth 
of  six  or  eight  inches. 

B  is  a  thermometer  for  ascertaining  the  heat  of  the  oil. 

C  is  a  small  tube  opening  at  the  lower  end  into  the  oil  ves- 
sel, while  the  upper  extremity  posse*  into  a  long  flue,  called  a 
•team  vent,  and  communicating  with  the  atmosphere.  This  pipe 


XIV  DESCRIPTION    OF   THE    PLATES. 

serves  three  different  purposes :  the  first  is,  that  before  the 
pump  beffins  to  work  in  the  morning,  there  is  a  quantity  of  air 
contained  in  it,  and  it  is  necessary  that  there  should  be  a  vent 
fior  that,  when  the  pump  is  set  to  work,  in  order  to  prevent 
any  compression  in  the  inside  of  the  vessel.  The  next  is,  that 
with  a  common  suction  pump  it  is  necessary  there  should  be  a 
communication  with  the  atmosphere.  Thirdly,  it  is  designed 
to  carry  off  the  aqueous  vapour  from  the  fresh  oil,  which  has  a 
very  bad  smell,  and  such  vapours  would  injure  the  sugars,  if 
they  got  abroad  in  the  sugar-house. 

D 18  a  cast-iron  pump  with  a  spring  metallic  piston  commu- 
nicating with  the  oil- vessel  A,  by  means  of  its  suction  pipe  E. 
It  b  set  in  motion  in  the  usual  manner,  by  some  mechanical 
power. 

F  is  a  copper  vessel,  the  bottom  of  which  is  covered  in  the 
inside  by  a  coil  of  pipe,  communicating  at  one  of  its  ends  with 
the  pump  at  G,  and  at  the  other  end  with  the  oil  vessel  through 
the  pipe  H.  Through  this  coil  of  pipe,  the  heated  oil  circulates, 
and  being  surrounded  on  all  sides  by  the  liquid  in  the  pan  F, 
it  gives  out  about  100^  of  its  heat  in  its  passage,  and  returns 
to  the  oil  vessel  to  obtain  a  fresh  increase  of  temperature. 
This  pan  is  surrounded  by  brick-  or  wood-work,  to  prevent  cool- 
ing.   Of  course  it  has  no  fire  under  it. 

Fig.  2  is  a  ground  plan  of  the  same  apparatus  in  which  the 
coil  of  pipe  in  the  evaporating  vessel  F  may  be  seen. 

A  18  the  oil  vessel  in  which  are  inserted  the  thermometer  B 
and  the  vent  pipe  C. 

D  is  the  pump. 

E,  G.  The  pipes  forming  the  communication  between  the  oil 
vttsel  and  evaporating  pan,  which,  after  chrculating  in  the  form 
of  a  coil,  passes  out  at  the  centre  of  the  bottom^  and  returns  to 
the  oil  vessel  by  the  pipe  H. 


CONTENTS 


VOL.  11. 


Pages. 
Essay    9.  On  the  Fixed  Alkalies •  •  •       3 

10.  On  Ekirthenware  and  Porcelain.  •     73 

1 1.  On  the  Manufacture  of  Glass  •  •   167 

12.  On  Bleaching    257 

13.  On  Water 355 

14.  On  Sal-Ammoniac    437 

15.  On  Edge  Tools 471 

16.  On  the  Manufacture  of  Tin-Plate  651 


Additional  Notes 583 

Table  of  Equivalent  Numbers  . .  621 
List  of  Books  quoted    •  • 649 


.   .  '  « 


CHEMICAI.   ESSAYS. 


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CHEMICAL  ESSAYS. 


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ESSAY  IX. 


ON 


THE   FIXED   ALKALIES. 


VOL.  II. 


B 


ESSAY    IX. 


THE    FIXED    ALKALIES. 


f  ROM  the  nature  and  origin  of  this  class  of 
bodies,  it  is  evident  that  mankind  must  have  ar- 
rived at  a  considerable  degree  of  civilization  before 
either  of  the  alkalies  could  have  been  brought  into 
general  use  :  we  shall,  however,  be  able  to  demon- 
strate that  they  were  employed  in  very  remote  pe- 
riods of  antiquity. 

To  those  who  are  unacquainted  with  chemical 
■ubjects,  and  who  have  never  had  an  opportunity 
of  examining  these  substances,  it  will  be  impossible 
to  convey  a  full  idea  of  their  nature  and  properties 
by  any  description  that  can  be  given  of  them  ; 
though  it  miiy  be  said,  that  when  in  a  state  of  pu- 
rity, their  chief  characters  are,  an  acrid  and  peculiar 
t«ste  ;  that  they  have  the  property  of  changing  blue 
v^table  juices  to  a  green ;  have  a  great  affinity 
for  animal  and  vegetable  oils,  with  ivhich  they  unite 


4  ON  THE   FIXED   ALKALIES. 

to  form  soap,  the  oils,  or  other  fatty  substances, 
being  in  this  way  rendered  miscible  with  water ; 
that  they  themselves  are  also  very  soluble  in  water ; 
and  lastly,  which  is  one  of  their  most  decisive  cha* 
racteristics,  that  they  readily  combine  with  and  neu- 
tralize the  acids,  forming  neutral  salts,  which  differ 
in  their  appearances  and  properties  according  to  the 
nature  of  the  respective  acids,  or  alkalies,  of  which 
the  salts,  are  composed. 

There  are  only  three  proper  alkalies  at  present 
known,  viz.  the  two  fixed  alkalies  i,  and  the  volatile 
alkali.  The  former,  which  are  known  by  the  names 
of  potash  and  soda,  will  constitute  the  principal  sub- 
ject of  the  present  Essay. 

The  word  iutimum,  which  was  in  use  among  the 
ancient  Romans,  is  evidently  derived  from  /ir,  wfaich 
signifies  a  lye  made  with  ashes  :  it  therefore  appears 
.  that  the  preparation  of  the  fixed  alkalies  from  the 
ashes  of  certain  burnt  vegetables,  must  have  been 
known  very  early ;  especially  as  /tjra,  another  Latin 
term,  signifies  a  worker  in  ashes.  Both  of  these 
words  are  used  in  the  same  acceptation  by  Colu- 
mella <  and  also  by  Pliny  3,  who  flourished  in  the 
century  immediately  preceding  the  commencement 
of  the  Christian  era. 

Marcus  Terentius  Varro,  the  renowned  Roman 
general,  who  wrote  in  the  first  century,  affords 
other  evidence  to  the  same  purpose ;  for  he  tells  us 

>  Lithia,  which  has  been  discovered  since  this  Essay  was 
written,  will  be  noticed  hereafter. 
*  lib.  xii.  cap.  41.  '  Nat,  Hist  lib.  xiv.  cap.  2. 


ON   THE    FIXED    ALKALIES.  5 

that  some  of  the  inhabitants  upon  the  Rhine,  being 
in  want  of  sea-salt,  used  a  substitute  which  they 
procured  from  some  species  of  wood  *.  These  peo- 
ple had  probably  learnt  a  method  of  neutralizing 
the  alkali  which  their  forests  afforded  them,  so  as 
to  form  a  salt  that  would  answer  some  of  the  pur- 
poses to  which  our  culinary  salt  is  generally  ap- 
plied. 

That  the  ancient  Romans  were  acquainted  with 
the  fixed  alkalies,  or  with  one  of  them  at  least,  is 
evident  from  a  circumstance  that  occurred  in  ex- 
ploring one  of  the  streets  of  the  ancient  city  of 
Pompeii,  which  was  overwhelmed  by  an  eruption  of 
Vesuvius  in  the  79th  year  of  the  Christian  era.  On 
examining  the  excavations  that  were  made  on  the 
spot  where  this  famous  city  formerly  stood,  a  com- 
plete soap-boiler's  shop  was  discovered,  with  soap 
in  it  which  had  evidently  been  made  by  the  com- 
bination of  oil  and  an  alkali.  This  soap  was  still 
perfect,  though  it  had  been  manufactured  more 
than  seventeen  hundred  years  ^. 

Aristotle,  who  flourished  nearly  four  hundred 
years  before  Christ,  says  that  the  ashes  of  cer- 
tain burnt  reeds  and  bulrushes,  when  macerated  in 
water,  yield  a  plentiful  supply  of  salt  ** :  and  accord- 
ing to  one  of  the  sacred  writers,  who  lived  still 
earlier,  his  cotemporaries  were  not  only  acquainted 


*  Varro  De  Re  Ruttica,  lib.  i.  cap.  7. 
'  See  Miss  Starke's  Letters  from  Italy. 

*  Meteor  n.  cap,  i. 


6  ON  THE   FIXED  ALKALIES. 

with  the  alkalies,  but  had  learnt  to  apply  them  to 
some  of  the  common  purposes  of  life7. 

It  does  not  with  certainty  appear  which  of  the 
fixed  alkalies  was  first  known,  though  I  concttve 
fhexe  i$  some  reason  for  assigning  the  priority  to 
aoda  as  having  been  first  in  use  for  domestic  pur- 
poses, as  nature  afibrds  it  to  the  inhabitants  of  se- 
veral parts  of  the  East  without  any  contrivance  or 
preparation  of  their  own.  It  appears  likewise  to 
have  been  known  by  the  term  niirum  s,  and  it  is  so 
described  by  several  of  the  ancient  writers. 

In  the  ninth  century,  an  Arabian  author  of  the 
name  of  Geber  describes  soda  very  distinctly,  and 
actually  distinguishes  it  from  potash.  But,  on  the 
other  hand,  Pliny  has  as  plainly  told  us  that  the 
Germans  of  his  day  used  potash  in  making  soap ; 
so  that  the  matter  of  priority  will  probably  ever  re- 
main in  uncertainty. 

The  word  alkali  is  of  Arabian  origin,  and  is  de- 
rived from  Kali,  the  name  of  a  species  of  vegetable 
from  which  soda  is  generally  extracted.  If  we  be- 
lieve Albertus  Magnus  9,  the  word  signifies  ySar 
amariiiuUniSf  *^  the  dregs  of  bitterness  ;**  the  parti- 
cle AL  having,  as  he  says,  been  added  by  the  Arabs, 

^  '^Thcni^h  thou  wash  thee  with  natron,  and  take  thee  mudi 
soap,  vet  thine  ini^uitv  is  marked  before  me."  Jeremiah  ii.  22. . 

*  Mr.  Delaval,  m  the  preface  to  his  ingenious  work  entitled 
"  An  Experimental  Inquiry  into  the  Came  of  the  Changee  y 
Colour^  in  opake  and  coloured  Bodies,^  remarks  that  **  tifie  ni- 
trum  of  the  ancients  is  sufficiently  characterized  and  distin- 
guished from  the  modem  nitre,  by  its  readily  forming  glass, 
when  mixed  with  sand,  and  exposed  to  the  fire.**    Kfr.  Delaval 


ON    THE    FIXED    ALKALIES.  7 

with  the  design  of  expressing  the  superiority  of  the 
article  obtained  from  the  plant  over  the  plant  it- 
self '".  In  the  days  of  Pliny  the  word  Kali  was, 
throughout  Egypt,  generally  used  to  signify  a  cer- 
tain vegetable  abounding  in  alkaline  salt,  which 
grew  on  the  8ea*shore,  on  the  banks  of  the  Nile, 
and  on  the  confines  of  the  river  Belus  in  Syria  i'. 
^e  same  word  is  in  use  also  with  us,  and  has  the 
same  signification. 

The  alkalies  have  a  very  peculiar  taste,  so  dif- 
ferent from  that  of  all  other  bodies,  that  it  will  be 
no  difficult  matter  for  the  student,  when  he  has 
once  made  himself  acquainted  with  it,  to  recognise 
them  at  all  times  by  this  peculiarity  alone  ;  but  as 
these  substances,  when  in  a  dry  and  pure  state,  are 
very  corrosive,  and  would  not  fail  to  blister  the 
tongue,  it  will  always  be  necessary,  for  this  pur- 
pose, to  dilute  them  plentifully  with  water. 

A  little  soda,  or  American  peartash,  on  the  point 
of  a  penknife,  might  be  dissolved  in  a  wine-glass  of 
water,  and  then  tasted  with  safety.  This  small 
quantity  will  flavour  the  water  sufficiently,  and  ex- 
hibit the  taste  which  I  have  just  noticed  as  peculiar 
to  this  class  of  substances. 


probably  did  not  know  that  our  nitre,  when  mixed  with  sand, 
aod  exposed  to  the  Gre.  will  make  good  glass.  For  an  expla- 
luUioo  of  thii,  see  the  Kssay  on  GIb.^s  in  this  volume. 

•  Thtatrum  Chemkum,  ii.  470.  Thomson,  8to,  1804,  vol.  i. 
463. 

"•  Fourcfoy**  System  of  Chemklry,  vol.  ii.  253. 

"  Dallowe'i  Edition  of  Boerhaawe'i  Elements  of  Chtmisiry, 
4lo,vol.  i.  pagr  440. 


8l  on  thk  fixed  alkalies. 

It  is  another  propertjr  belonging  to  the  alkalies, 
that  they  change  many  of  the  blue  vegetable  juices, 
such  as  the  violet  and  mallow  flowerst  to  a  green ; 
though  if  litmus  be  treated  with  either  potash  or 
soda,  the  colour  will  be  rendered  rather  more  in- 
tensely blue.  By  making  this  experiment,  whiiOi 
may  be  done  without  any  peculiar  apparatus  or  ex- 
pense, this  characteristic  of  the  alkalies  will  be  im- 
printed on  the  mind,  so  as  never  to  be  effaced. 

Let  the  student  prepare  a  solution  of  the  potash 
or  pearlash  of  commerce,  and  when  a  little  of  this 
is  poured  into  a  wine-glass  containing  one  of  the 
common  bltie  vegetable  decoctions,  the  whole  will 
immediately  be  changed  to  di  green.  If  a  few  drops 
of  diluted  sulphuric  acid  be  then  added,  the  alkali 
will  be  saturated,  and  the  colour  will  in  some  mea- 
sure be  restored ;  and  by  adding  a  very  little  more 
of  the  acid,  the  whole  fluid  will  assume  a  beautiful 
crimson.  Hot  water  poured  on  a  few  slices  of  the 
red  cabbage  will  produce  a  blue  decoction,  very 
suitable  for  this  experiment ;  or  a  strong  infusion 
of  the  drie&  flowers  of  the  red  rose  will  answer  the 
same  purpose. 

Although  the  alkalies,  as  has  just  been  stated, 
convert  the  blue  vegetable  juices  to  a  green,  they 
produce  a  deep  brown  in  the  vegetable  yellows. 
Thus,  if  a  few  drops  of  the  solution  of  potash  or  of 
soda  be  added  to  an  infusion  of  turmeric,  the  yellow 
will  instantly  be  converted  to  a  brown ;  and  this 
new  colour  will  be  permanent,  unless  it  be  after- 
wards  treated  with  an  acid,  which  has  the  power  of 


ON    THE    FIXED    ALKAL1E3.  9 

restoring  the  original  yellow ;  acids  and  alkalies, 
according  to  the  predominance  of  either,  having 
theproperty  of  alternately  changing  the  hue  of  most 
vegetable  colours.  Hence  the  great  use  of  this 
class  of  substances  in  the  arts,  especially  in  dyeing, 
and  in  the  manufacture  of  several  of  the  blue  and 
green  colours  which  are  prepared  for  the  painter. 

The  potash  and  pearlash  of  commerce  were 
thought  to  be  pure  simple  substances,  until  Dr. 
Black,  in  the  year  1756,  satisfactorily  proved  that 
they  all  contain  a  considerable  portion  of  carbonic 
acid.  The  readiness  with  which  Ume  deprives  this 
alkali  of  its  carbonic  acid  may  be  shown  by  the  fol- 
lowing very  simple  experiment.  Pour  a  little  clear 
solution  of  carbonate  of  potash  into  &  wine-gtass  of 
transparent  lime  water  ;  and  tliougli  both  liquors 
were  perfectly  limpid  as  the  purest  water  while  se- 
parate, they  will  instantly  become  turbid  on  mix- 
ture ;  for  the  Ume,  absorbing  the  carbonic  acid  from 
the  alkali,  will  be  converted  to  carbonate  of  lime  or 
chalk,  which,  being  an  insoluble  compound,  will 
precipitate  in  a  white  powder. 

The  largest  consumption  of  the  alkalies  is  chiefly 
in  the  making  of  soap  and  glass.  The  principal 
part  of  the  kelp  that  is  prepared  on  the  coasts  of 
Wales,  Scotland,  and  Ireland,  is  employed  in  the 
6r8t  of  these  compounds,  besides  some  thousand 
tons  of  barilla  annually  imported  frum  the  Conti- 
nent, particularly  from  Spain,  and  from  certain 
iilands  in  the  Mediterranean. 

In  the  manufacture  of  soap,  these  rough  alkalies 


10  ON   THE    FIXED   ALKALIES. 

are  bruised  by  means  of  a  borse-mill ;  and  when 
mixed  with  a  portion  of  quick-lime  sufficient  to  de« 
prive  them  of  their  native  carbonic  acid,  or  fixed 
air  as  it  was  formerly  called,  they  are  put  as  lightly 
as  possible  into  large  cast-iron  vats  cafMe  of  hold* 
ing  from  one  to  five  or  six  tons  each. 

When  these  vats  are  thus  charged,  water  is  let 
in  until  it  rises  an  inch  or  two  above  the  sorfiice 
of  the  materials,  care  being  taken  that  it  run  on  in  a 
regular  gentle  stream,  so  as  not  to  render  the  chai^ 
too  solid,  which  would  prevent  the  lye  from  running 
properly  through  it.  The  design  of  the  water  is  to 
dissolve  the  alkali  that  is  contained  in  the  kelp,  or 
barilla,  and  in  this  way  to  separate  it  from  the  va^ 
jrious  insoluble  matters  which  these  articles  always 
contain. 

The  lime  does  not  impart  any  of  its  own  pro« 
perdes  to  the  lye  or  the  soap,  as  is  often  believed ; 
it  is  employed  merely  to  deprive  the  alkali  of  tha 
carbonic  acid  which  has  just  been  noticed,  and 
which  would  incapacitate  the  alkali  for  forming  that 
intimate  union  with  the  oil  or  tallow  which  is  re* 
quired  to  render  the  whole  into  a  perfect  soap,  so- 
luble in  water. 

When  the  charge  has  stood  thus  covered  with  the 
fluid  for  twelve  hours  or  more,  the  wooden  plug 
near  the  bottom  of  the  vat  is  loosened,  and  the  al- 
kaline lye  which  has  been  formed  is  suffered  to  run 
off  gradually  into  a  large  iron  receiver,  fixed  under- 
neath and  below  the  floor  of  the  manufactory.  Thb 
is  called  lye  of  the  first  running ;  and,  being  the 


ON   THE    FIXED    ALKALIES. 


II 


Strongest,  it  is  generally  reserved  for  the  last  ope- 
rations in  tlie  manufactory.  The  lixivium  which 
has  run  from  an  adjoining  but  weaker  vat,  is  now 
pumped  upon  that  which  has  just  been  drained, 
and  the  whole  is  suffered  to  remain  at  rest  as  be- 
fore. The  liquor  is  thus  pumped  from  beneath  one 
vat  upon  the  contents  of  another,  and  that  again  is 
replenished  from  the  adjoining  one,  day  after  day, 
in  regular  succession,  until  the  last  of  the  series, 
which  has  frequently  been  covered  with  simple 
water,  is  thought  to  be  entirely  spent.  When  this 
is  the  case,  the  plugs  are  at  once  taken  out  of  the 
whole  row  of  vats,  and  the  contents  are  suffered  to 
drain  for  some  time,  preparatory  to  their  being  cast, 
as  it  is  called,  which  is  performed  in  the  following 
manner: — The  ashes  of  the  spent  vat  are  first 
thrown  out  as  a  refuse  article;  and  when  this  vat  is 
entirely  empty,  the  contents  of  the  adjoining  one 
are  thrown  in,  and  so  on  to  the  end  of  the  row,  or 
to  the  beginning  of  the  series,  when  the  first  vat, 
being  then  empty,  is  re-filled  with  a  new  charge  of 
kelp  or  barilla.  The  plugs  are  now  replaced,  and 
(he  ashes  in  each  vat  are  again  covered  with  the 
weak  lye  from  the  receiver  that  is  immediately  un- 
demeatl)  it.  Thus  the  whole  of  the  alkali  and  al- 
kaline  salts  are  dissolved,  and  the  lixivium  formed 
at  a  small  expense  of  labour.  By  suffering  the  ashes 
thus  to  drain  themselves  entirely  dry,  and  then 
casting  them  with  large  shovels  into  another  vat, 
such  parts  as  may  have  become  conglomerated  are 
broken,  so  that  every  thing  which  is  soluble  has  a 


12  ON   THE   FIXED   ALKALIES. 

chance  of  coming  in  contact  with  the  fluid,  and  of 
being  dissolved  by  it. 

This  narrative  might  perhaps  have  appeared  with 
more  propriety  in  an  essay  upon  soap-making ;  but 
while  treating  expressly  on  the  fixed  alkalies,  I  was 
desirous  of  describing  the  method  by  which  they 
can  be  rendered  caustic  at  the  least  expense. 

The  alteration  which  is  produced  in  the  alkalies 
of  commerce  by  the  admixture  of  quick-lime  is  so 
manifest,  and  is  attended  with  such  important  con- 
sequences, that  the  circumstance  ought  never  to 
be  forgotten  by  those  who  are  engaged  in  any  of 
the  manufactories  where  large  quantities  of  potash 
or  soda  are  consumed :  for  in  some,  the  quality  of 
the  manufactured  article  is  much  influenced  by  the 
state  of  the  alkali ;  and  in  others,  very  great  savings 
might  be  made  by  using  caustic  potash,  or  so- 
da >^,  in  cases  where  the  mild  alkalies  are  now  em« 
ployed.  • 

Many  instances  of  these  peculiar  efiects  might 
be  adduced :  but  I  shall  select  one  from  the  deter- 
sive property  of  the  alkalies,  that  will  sufliciently 
elucidate  the  practice  which  I  am  now  attempting 
to  enforce. 

In  scouring  woollen  yarn  to  free  it  from  the  oil 
which  is  combined  with  it  in  combing  and  spin- 
ning, it  is  no  uncommon  thing  for  the  workmen  to 


"  A  remarkable  instance  of  the  economy  of  using  caustic  in- 
stead of  mild  alkali  may  be  seen  in  the  Essay  on  Bleaching,  in 
a  subsequent  part  of  this  volume. 


ON   TU£    FIXED   ALKALIES. 


13 


1  large  boiler  of  1 


lissolving  Aine- 
rican  or  Russian  pearlash  in  water,  by  means  of 
heat.     When  tliis  liquor  is  hot,  they  immerse  their 
brown  yarn  in  it,  and  soon  find  it  sufficiently  freed 
from  the  oil  and  other  filth  that  is  attached  to  it. 
More  is  then  immersed,  hut  tliis  takes  a  longer 
time  to  become  clean  ;  and  the  next  parcel  longer 
still ;   till  at  length  it  is  so  far  spent  as  to  have  little 
or  no  effect  upon  the  yarn,  and  is  therefore  suffered 
to  run  away  to  make  room  for  a  fresh  lixiviation, 
although  one  half  of  the  alkali  in  the  former  one  is 
not  consumed.     Instead  of  proceeding  in  this  way, 
let  the  workman  mix  a  quantity  of  potash  witii  one- 
fourth  of  its  weight  of  fresh  burnt  quick-lime,  (if 
pearlash  be  used,  one-half  its  weight  of  lime  should 
be  taken,)  put  it  into  a  vat,  or  into  an  iron  pan» 
and  then  by  the  addition  of  water  make  a  lixivium 
from  it,  as  described  above,  and  put  only  so  much  of  ' 
this  into  the  hot  water  as  is  necessary  to  scour  that  1 
quantity  of  wool  or  yarn  which  is  usually  cleansed  1 
at  once.     Then  let  him  add  a  few  quarts  more  for  1 
the  next  parcel,  and  proceed  in  this  way  until  the  j 
whole  be  finished,  and  he  will  find  that  any  given  | 
quantity  of  work  may  be  done  with  more  expedi- 
tion, and  with  less  than  half  the  alkali  that  is  usually 
employed. 

The  lye  made  in  the  common  mode  operates  very 
well  at  first,  because  a  portion  of  the  alkalies  of 
commerce  is  generally  in  a  caustic  state ;  but  as 
soon  as  this  is  saturated  with  the  oil  of  the  yarn,  the 
remaining,  and  often  the  greater  part,  having  no  ef- 


14  ON  THE   FIXED   ALKALIES. 

feet  in  the  way  they  use  it,  it  thrown  away  as  use- 
kss^  and  is  a  total  loss  to  the  manufiieturer.  Many 
thousand  pounds,  I  believe,  are  thus  lost  to  the 
communis  annuallyj  which  might  be  saved  by  a 
general  knowledge  of  this  simple  fact,  that  alkalies 
will  not  combine  with  oUagifums  matter^  unless 
they  are  actually  in  a  state  of  causticity.  The 
greater  part  of  our  American  pearlash  is  combined 
with  a  very  large  portion  of  carbonic  acid^  and 
therefore  it  is  not  in  a  condition  to  combine  with 
oil ;  but  let  it  be  divested  of  this  acid,  and  it  will 
not  only  form  an  intimate  union  with  whatever  <nl 
or  grease  it  comes  in  contact  with,  but  it  will  ren« 
der  these  impurities  so  completely  soluble  in  watar, 
that  the  whole  will  be  as  easily  washed  out  from  the 
yarn,  and  dissolved,  as  if  it  were  sugar  or  salt. 

Potash,  as  has  before  been  mentioned,  is  pte- 
pared  from  the  ashes  of  burnt  wood,  and  is  chiefly 
manufactured  in  those  countries  where  there  is  an 
abundant  supply  of  timber.  It  is  observable,  that 
in  the  middle  of  the  last  century  it  was  not  known 
how  to  make  either  potash  or  pearlash  in  any  part 
of  North  America,  equal  in  quality  to  that  which 
had  usually  been  imported  from  Russia.  This  was^ 
however,  at  length  effected  by  the  persevering  en- 
deavours of  a  Mr.  Thomas  Stephens,  who  about 
the  year  1753  received  a  grant  from  the  Parliament 
of  England  for  his  encouragement  '3.   The  Russian 


"  See  TAc  Method  and  plain  Process  for  making  Potash,  by 
Thomaft  Stephens^  4to^  with  plates.  London. 


ON   THE    FIXED    ALKALIES.  15 

method  of  making  potash  from  large  wood  is 
fiiUy  described  by  Boerhaave  in  his  System  of  Cke- 
mistry'**:  he  has  also  given  ample  directions,  in 
the  same  work  ",  how  Tsrious  smaller  vegetables 
may  be  managed  in  different  circumstances^  so  as 
to  be  burnt  for  the  production  of  potash  '^ ;  and 
though  there  may  be  few  cases  in  which  his  pro- 
cesses would  answer,  in  this  country,  on  a  large  scale, 
yet  a  perusal  of  his  narrative  will  not  fail  to  give  the 
reader  a  very  correct  idea  of  the  methods  for  ob- 
taining this  singular  substance.  More  economical 
directions,  however,  and  perhaps  the  best  hitherto 
devised,  may  be  seen  in  the  j4nnales  de  Chimie  ". 

It  ha£  generally  been  imagined  that  the  alkali 
which  is  procured  from  vegetables  is  the  creature 
of  fire  ;  but  I  know  of  one  case  (and  there  may  he 
many  orfiers)  in  which  vegetables  are  employed  for 
the  sake  of  the  alkali  they  contain,  without  previ' 
ousty  burning  tliein.  I  refer  to  the  operation  of 
fulling  woollen  cloth. 

When  woollen  cloth  comes  from  the  hands  of 
the  weaver,  it  is  carried  to  the  fulling  mill,  where 


**  Dallowe'K  edition  of  Boerhaave's  Elements  of  Chemutry, 
vol.  i.  page  443. 

"  ifrW.  vol.  ii.  page  28 — 35. 

■■  The  Earl  of  Dundonald  has  proposed  the  cultivniion  of  the 
connnon  plant  called  Tanug,  the  Tanacetum  of  Linnteua,  for  the 
production  of  this  iilkiili,  oMerCing  that  it  will  yield  more  pot- 
wh  than  can  be  procured  from  an  equal  weight  of  any  other 
regetable.  The  Kinlanders  obtain  u  green  dye  fmm  this  plant. 
See  Dr.  Withering's  Sifstematie  .4rrnng*ment  of  Briliih  Planta, 
vol.  iii.  page  872. 

"  Tom.  xix.  page  l^7—l'J3. 


16  ON  THE   FIXED   ALKALIES.  ^ 

it  undergoes  a  long-continued  beating  by  ponderous 
wooden  hammers,  which  are  moved  with  consider- 
able force  by  a  large  water*wheel.  By  this  treat- 
ment the  cloth  becomes  considerably  thicker,  closer, 
and  better;  losing  in  its  length  and  breadth  ex- 
actly in  proportion  to  its  increased  thickness.  But 
it  is  rather  a  curious  circumstance,  that  no  woollen 
cloth  will  thicken  by  this  operation  until  it  be  cB- 
vested  of  the  oil  or  grease  which  the  wool  had  ac- 
quired in  the  process  of  combing  and  carding.  To 
effect  this,  the  following  articles  are  made  use  of, 
viz.  an  earth  which  is  principally  brought  from 
the  county  of  Kent,  call^  fuUers'-earth,  common 
hard  soap,  and  a  portion  either  of  potash,  or  the 
crystals  of  soda. 

In  the  county  of  York,  however,  where  there  aie 
many  hundreds  of  poor  weavers  who  work  in  thdr 
own  small  cottages,  and  produce  perhaps  one  piece 
of  cloth  only  in  a  week  or  a  fortnight,  it  is  cus- 
tomary for  them  to  take  it  to  a  public  mill,  with 
the  necessary  quantity  of  scouring  materials,  and 
there  to  superintend  the  operation,  until  the  cloth 
is  brought  to  that  thickness  which  they  conctdve 
will  occasion  it  to  s^ll  niost  to  their  advantage. 

Now  I  understand  it  is  no  unusual  thing  for  those 
poor  people  who  wish  to  avoid  the  expense  of  buy- 
ing alkalies,  to  send  their  wives  and  children  to  an 


**  In  the  Annates  de  Chinde  for  the  year  1791,  there  is  a 
paper,  by  Bouvier,  on  the  analysis  of  the  Fwci.  See  vol.  ix. 
page  83—95. 


ON    THE    FIXED    AI.KALIKS.  IT 

adjoining  common  to  collectycr/i,  which  they  throw 
into  the  mill  with  the  piece,  where  its  alkaline  juices 
are  expressed  '^  and  worked  into  the  cloth ;  and  tliat 
by  this  as  good  an  effect  is  produced  as  if  soda  or 
potash  bad  been  employed.  And  in  other  cases, 
where  soap  and  alkali  have  been  used,  and  too  small 
ft  quantity  of  these  has  been  taken,  so  that  the  cloth 
will  not  thicken  sufhciently,  a  small  parcel  of  fern 
will  occasion  the  operation  to  commence,  and  it 
will  then  go  on  as  well  as  could  be  desired.  Some 
of  the  lower  class  of  weavers  derive,  as  I  have  been 
told,  considerable  advantage  from  their  knowledge 
of  this  very  valuable  plant  '9, 

Potash  may  also  be  procured  from  the  ashes  of 
burnt  peat :  but  this  Is  not  a  source  from  which  it 
is  generally  obtained  ;  nor  do  I  know  that  the  me- 
thod is  at  all  practised  any  where  but  in  the  High- 
lands of  Scotland,  where  the  poor  inhabitants  have 
leamt  how  to  make  the  soap  for  their  domestic 
uses,  from  the  ashes  of  their  own  peat  fires  *?.  A 
letter  from  Glenesk  in  North  Britain,  on  the  ma- 
nufacture of  alkali  from  peat,  was  published  some 
years  ago  in  the  Tradesmaji's  Ma^azine^^, 

Potash  may  likewise  be  obtained  from  saltpetre, 
by  heating  it  sufHciently  with  charcoal,  or  any  car- 


■*  See  a  paper  by  Monge  on  the  Fulling  of  Woollen  Cloth  in 
the  sixth  volume  of  the  AnnaUt  4e  Chimie,  pages  300 — 3 1 1 . 

•"  A  curious  account  of  the  method  by  which  peat  is  con- 
imA  from  the  tops  of  the  mountains  in  Cnmberland,  by  the 
neiKhbouring  peasantry,  is  described  in  West's  Guide  lo  the 
hSit*,  in  Cumberland,  tVeitmoreUind,  Sec.  page  96. 

"  TTie  TradetmmCn  ny  Cnmmerrial  MH^'-iiine,  vol.ii.  p.  51". 


18  ON   THE    FIXED  ALKAUES. 

bonaceous  matter  that  will  decompose  its  acid.  In 
this  way  one  hundred  weight  of  nitre  will  yield 
nearly  half  a  hundred  weight  of  pure  potash ;  and 
whenever  the  relative  prices  of  American  fiotash 
and  nitre  will  admit  of  it»  the  latter  siibstafiefe  may 
be  employed  with  profit  for  the  production  of  this 
alkali.  During  our  dispute  witii  America,  when 
the  importations  of  pot-*  and  pearl-ash  were  so  small 
as  to  occasion  a  considerable  advance  on  the  cus^ 
tomary  prices  of  those  articles,  a  large  quantity  ot 
saltpetre  was  consumed  in  Great  Brit^  for  the 
above  purpose ;  and  for  the^^f^  kinds  of  flint  glfiss, 
saltpetre  may  generally  be  substituted  for  potadi 
with  advantage. 

Potash  has  been  obtained  in  Germany,  in  pretty 
large  quantities,  from  the  pyroligneous  acid,  by 
pouring  this  acid  on  wood  ashes,  and  then  fluidng 
the  whole  in  a  furnace  of  brick  or  stone.  The  pro- 
cess is  described  by  Glauber,  in  his  JMiraculum 
Mundi,  with  considerable  minuteness  ^.  Where 
saw-dust,  straw,  the  tendrils  of  the  hop,  or  bean- 
haums  can  be  had  in  abundance,  it  might  perhaps 
be  advantageous  to  soak  such  materials  in  this  add, 
and  then  to  burn  and  flux  the  whole  into  a  saleable 
ash.  But  the  oil  should,  if  possible,  be  previously 
separated  as  much  as  possible  from  the  pyroligneous 
acid. 

Macquer  relates,  that  in  some  parts  of  Germany 
potash  is  prepared  from  the  same  parcels  of  wood 

^  Glauber,  Chemical  Wwks,  folio,  page  188. 


ON   THE    KIXEU    ALKALIES. 


19 


of  wluch  charcoal  is  made.  A  number  of  tubes 
made  of  plate  iron  or  of  copper,  are  so  disposed  in 
the  pile  of  wood  intended  to  be  burnt  into  char- 
coal, that  the  acid,  &c.  is  collected  in  reservoirs; 
and  when  the  oil  is  separated  the  fluid  is  boiled  in 
iron  vessels,  and  the  residuum  is  converted  by  cnl- 
cinstion  to  an  alkali  *3, 

Potash  is  a  component  part  of  pumice-stone,  and 
of  some  other  mineral  productions.  Professor  Abil- 
gaart  found  that  this  alkali  formed  also  a  consti- 
tuent part  of  animal  blood  2*  ;  but  it  seldom  occurs 
in  other  animal  substances,  except  in  very  minute 
qnantittee. 

Before  I  close  this  account  it  may  be  useful  to 
remark,  that  the  buyers  of  American  potash  gene- 
rally prefer  that  whicli  breaks  red,  whicli  is,  as  I  ap- 
prehend, a  mere  prejudice ;  for  1  have  reason  to 
think  that  this  colour  arises  chiefly  from  the  pre- 
face of  sulphur,  and  perhaps  oxide  of  iron,  neither 
of  which  can  be  of  any  use  where  a  good  alkali  is 
required.  I  have  ascertained  that  some  English 
makerB  of  potash  who  are  acc]uainted  with  this  effect 
of  sulphur,  designedly  add  a  portion  of  that  sub- 
stance to  their  ash,  while  it  is  in  a  state  of  fusion  ; 
and  by  taking  a  little  from  the  melted  mass  after 
every  addition  of  the  sulphur,  and  suffering  that  to 
cool  for  examination,  they  are  easily  enabled  to 


•■  S«  Ihc  article 

'  Alkali,"   in  Macqucr's 

Chemical  Di,- 

lunutry,  toI.  i. 

"  PwkiTHon'ii   itfp' 

•,ri,„-k<    awmicl.  lourll 

edilion.  IWO/, 

(»R»  1 1 . 

20  ON  THE   FIXED   ALKALIES. 

bring  the  whole  to  that  colour  which  will  best  suit 
the  market. 

Whenever  this  alkaK  is  employed  for  nice  pur- 
posesy  the  article  called  pearlasK  is  generally  pre- 
ferred to  potash.    This  is  prepared  by  a  long  con- 
tinued calcination  of  potash,  at  a  low  heat,  whereby 
the  sulphur  and  carbon  which  it  contdns  are  mostly 
burnt  off.     But  as  all  the  pearlash  which  comes 
from  Russia  and  America  contains  a  considerable 
proportion  of  neutral  salts,  it  has  long  been,  and 
still  continues  to  be,  our  task  to  deprive  it  of  these 
adulterations.     And  lately,  several  persons  in  va- 
rious parts  of  this  kingdom  have  established  manu- 
factories for  preparing  this  alkali,  and  have  pro- 
duced considerable  quantities,  and  comparativdy  in 
a  state  of  great  perfection,  from  various  chemical 
residuums,  which  were  formerly  rejected  as  of  no 
value. 

In  the  neighbourhood  of  Birmingham  there  were 
formerly  some  very  considerable  manufactories  of 
pot-  and  pearl-ash ;  and  I  have  understood  that  the 
makers  were  enabled  to  sell  both  articles  of  as  good 
quality  and  as  cheap  as  the  foreign. 

Having  thus  fully  treated  ^on  the  history  and 
origin  of  potash ;  on  its  various  sources  foreign  and 
domestic;  and  on  its  nature  and  properties,— -it  will 
now  be  proper  to  give  some  account,  however  con- 
cise, of  the  several  salts  which  are  formed  by  its 
means,  or  which  contain  potash  as  one  of  its  prin- 
cipal ingredients. 


ON   THE    FIXED    AI.KALIEs.  2\ 

j4ertale  of  potash,  formerly  called  digestive  salt 
of  Sylvius. — It  is  in  the  form  of  plates  or  prismatic 
crystals.  These  dissolve  in  their  own  weight  of 
water  at  60°.  The  solution  has  an  acrid  saline 
taste.     The  salt  is  composed  of 

1  proportional  of  potash  =     45 

1        ditto        of  acetic  Bciil      =     48 

93 

Ammonio-svlphate  of  potash. — ^This  salt  is 
formed  by  adding  amnionic  to  the  bi-sulphate  of 
potash.  The  process  is  described  by  Link  in  Crell's 
Annals  for  1796,  voi.  i.  p.  26.  It  has  a  bitter  taste 
like  the  common  alkaline  sulphates,  and  crystallizes 
in  brilliant  plates,  which  are  not  altered  by  exposure 
to  the  air.     The  salt  consists  of 

Sulphate  or  potash CO 

Sulphate  of  a 


Atttimoniaic  of  potash. — This  is  a  white  powder 
possessing  an  acrid  and  metallic  taste.  It  dissolves 
in  boiling  water,  but  is  scarcely  acted  upon  by  cold 
water.    According  to  Berzelius,  it  is  composed  of 

■    Antimonic  acid 79.2 

Potash 20,8 

100.0 

/tntitnonlte  of  potash.  In  an  Essay  on  Chemical 
Nomenclature,  Berzelius  states  this  salt  to  be  com- 
posed of 

AntintonioiiN  aciil 76.r> 

Potash ^3^ 

100.0 


22  ON  THE   FIXED   ALKALIES. 

See  Nichol8on*s  Journal^  vol.  xxxv.  p.  44.    This 
salt  is  insoluble  in  cold,  but  soluble  in  boiling  water. 

Arseniate  of  potash. — ^This  salt  is  formed  by  sa- 
turating arsenic  acid  with  potash.  It  is  deliquescent 
when  exposed  to  the  air,  and  is  incapable  of  cry- 
stallization. It  renders  syrup  of  violets  green,  but 
has  no  effect  on  an  infusion  of  turnsole. 

Arsemte  of  potash. — ^This  is  a  very  soluble  and 
incrystallizable  salt.  It  is  formed  by  boiling  white 
arsenic  in  a  solution  of  potash.  This  salt  is  the 
most  important  ingredient  in  Fowler*s  tastekgs 
ague  drop. 

Aurate  of  potash. — ^This  compound  is  intro* 
duced  here,  on  the  authority  of  Pelletier.  This 
chemist  has  stated  that  pure  potash  is  capable  of 
dissolving  the  oxide  of  gold,  and  has  named  the 
compound  aurate  of  potash. 

Ben%oate  of  potash. — ^This  is  a  deliquescent  salt, 
very  soluble  in  water.  If  this  salt  be  digested  with 
benzoic  acid,  a  bibenzoate  will  be  produced  in  aci- 
cular  and  lamellar  crystals,  which  require  ten  parts 
of  cold  water  for  their  solution.  See  Bucholz, 
Annates  de  Chimie,  vol.  Ixxxiv.  page  311. 

Bicarbonate  of  potash. — ^This  salt  is  usually 
made  by  passing  carbonic  acid  gas  into  a  solution 
of  potash  in  water,  and  evaporating  the  fluid  to  the 
point  of  crystallization.  The  crystals  which  sepa- 
rate are  in  the  form  of  fouf-sided  prisms,  with  di- 
hedral summits.    Tlie  dry  salt  consists  of 

2  proportionah  of  carbonic  acid    =     41.4 
1       ditto  of  potash  =     45.0 

864 


ON   THE    FIXED    ALKALIES. 

Wtien  crystallized  it  consists  of 

Dr\'  salt 80.4 

Water 8,5 


Birtarseniate  of  potash. — A  salt  formerly  known 
by  the  name  of  the  arsenical  neutral  .salt  of  Mac- 
quer.  It  may  be  formed  by  adding  arsenic  acid  in 
excess  to  potash,  and  evaporating  the  solution.  The 
salt  appears  in  quadrangular  crystals,  terminated  by 
four-sided  pyramids.  It  is  much  employed  for  the 
cure  of  agues.  It  is  soluble  in  water;  and,  like  the 
adds,  it  changes  the  blue  juices  of  vegetables  to  a 
red.     It  is  composed  of 

1  proportioni^  of  potash  <=  M 

2  ditto         of  arsenic  acid  =  133 

178 
Sinoxalate  of  potash  is  formed  merely  by  dis- 
solving the  crystals  of  oxalate  of  potash  in  oxalic 
acid.  It  also  exists  ready  formed  in  wood-sorrel, 
the  Oxalis  acetosella  of  Linnaeus.  When  extracted 
it  is  sold  under  the  improper  name  of  essential  salt 
ofU'uuins.     It  is  composed  of 

1  proportional  of  polosh  =s         4.'> 

2  ditto        of  oxulic  acid         =         1 1 


Biphosphale  of  potash. — ^This  salt  is  easily  form- 
ed by  dissolving  pliosphate  of  potash  in  phosphoric 
acid,  and  evaporating  the  liquor  to  the  point  of  cry- 
stalllzalion.     Il  crystallizes  in  -iiuall  striated  prisms 


24  ON   THE   FIXEJO  ALKALIES. 

which  are  exceedingly  soluble  in  water.  The. salt 
when  dry  has  the  specific  gravity  of  2.85 1.  Hassen- 
fratz,  Annales  de  Chvnde^  tome  xxviii.  page  14. 

BistUphate  of  potash. — Tbb  salt,  which  is  the 
arcanum  duplicatum  of  the  old  chemists,  inay  be 
formed  by  boiling  the  common  sulphate  of  potash 
in  sulphuric  acid.  It  generally  separates  firom  its 
water  of  solution  in  needle-shaped  crystals,  wludi 
are  soluble  in  two  parts  of  water  at  60^.  This  salt 
contains  twice  as  much  acid  as  the  sulphate  of  pot- 
ash. See  Dr.  Wollaston*s  paper  on  Super-salts  and 
Sub-salts  in  the  Phil.  Trans,  for  1808. 

Bitartrate  of  potash  is  the  common  tartar  of 
commerce.  It  exists  in  the  juice  of  the  grape,  and 
when  deposited  on  the  sides  of  wine-casks  is  known 
by  the  name  of  argol.     It  is  composed  of 

2  proportionals  of  acid        s       125 
1       ditto         of  potash     =        45 

170 

This  salt  requires  1 20  parts  of  water  at  60^,  or  30 
parts  at  212^,  for  its  solution. 

Boletate  of  potash. — ^The  boletic  acid  is  obtained 
from  the  juice  of  the  Boletus pseudo^igniarius.  The 
boletate  of  potash  was  formed  by  Braconnot :  but 
all  that  he  has  said  of  it  is,  that  it  is  very  soluble  in 
water,  that  it  is  not  easily  procured  in  crystals,  and 
that  other  acids  precipitate  the  boletic  acid  from  it. 
See  Annates  de  Chimie,  tome  Ixxx.  page  278. 

Borate  of  potash. — ^This  salt  may  be  obtdned 
either  in  a  dry  mass  or  crystallized.     The  crystals 


ON   THE    FIXED    ALKALIES.  'Jo 

iie  quadrangular  prisms,  unalterable  by  exposure 
to  the  air.  The  properties  of  this  salt  are  little 
known.  Berzelius  attempted  to  ascertain  its  con- 
stituent parts,  but  without  success.  It  may  be 
procured  by  boiling  boracic  acid  in  a  solution  of 
potash. 

Camphoratc  of  potash  may  be  made  by  satu- 
rating a  solution  of  carbonate  of  potash  with  cam* 
phoric  acid. — The  salt  crystallizes  in  regular  hex- 
agons, which  are  soluble  in  about  100  parts  of  water 
at  60°,  or  in  S.")  parts  at  212°.  It  is  soluble  in 
alcohol,  and  the  solution  burns  with  an  intense  blue 
flame. 

Carbonate  of  potash. — Large  quantities  of  this 
salt  are  imported  into  this  country  under  the  names 
of  potash  and  pearlash — articles  very  generally 
known.  It  is  sometimes  procured  from  nitre,  and 
also  ft'om  tartar.  If  these  salts  are  submitted  to  a 
red  heat  with  carbonaceous  matter,  their  acids  are 
separated  thereby,  and  carbonate  of  potash  is  formed. 
It  consists  of 

Carbonic  acid 20.7 

Potash 45.0 


Chlorate  of  potash,  formerly  called  hyper-oxy- 
muriate  of  potash,  is  made  by  passing  a  current  of 
chlorine  gas  into  a  solution  of  potash,  or  carbonate 
of  potash  in  water.  It  crystallizes  in  thin  plates. 
Whenmixed  with  sulphur  or  phoapliorus  it  explodes 
by  trilaration.     See  an  iiccounl  of  many  of  these 


26  ON  THE   FIXED   ALKALIES. 

experiments  in  the  Chemical  Catechism.  This  salt 
is  composed  of 

1  proportional  of  chloric  acid       =s        71 
1       ditto       ofpotadi  =s       45 

116 

Chramate  of  potash. — ^According  to  Vauquelui, 
there  are  two  species  of  this  salt,  viz.  the  neatral 
chromate,  and  the  bichromate.  The  former  is  of 
a  pale  lemon  colour,  the  latter  of  an  orange  ydlow 
colour.  They  both  crjrstallize  in  small  prisms.-— 
AmnaUs  de  Chbnie,  tome  hoc.  page  88. 

Citrate  of  potash. — This  salt  has  been  already 
described  in  the  Essay  on  Citric  Acid,  vol.  i.  p.  578. 

Cohanbate  of  potash. — By  boiling  the  columbic 
add  in  a  solution  of  potash,  this  salt  is  produced 
in  white  scales  resembling  those  of  boracic  add. 
When  the  mineral  acids  are  added  to  a  solution  of 
this  salt,  the  columbic  acid  is  separated  in  the  form 
of  a  white  powder.  See  Hatchett,  Phil.  Trans. 
for  1802- 

Ferrocyanate  of  potash  is  a  salt  much  used  in 
calico-printing. — It  may  be  prepared  by  digesting 
Prussian  blue  in  a  hot  solution  of  caustic  potash. 
It  is  a  triple  salt,  composed  of  hydrocyanic  acid, 
potash,  and  oxide  of  iron.  It  crystallizes  in  fine 
cubic  and  tabular  crystals  of  a  bright  yellow  colour, 
and  unchangeable  in  the  air.  See  the  Eissay  on  Ca- 
lico-printing, vol.  i.  page  205 . 

Ferroiartrate  of  potash  may  be  made  by  digest- 
ing iron  filings  with  tartar,  in  the  proportion  of  one 


ON   THE   FIXED   ALKALIES.  27 

part  of  iron  with  two  parts  of  tartar,  and  then  holl- 
ing  the  mass  in  a  proper  quantity  of  water  to  dis- 
solve the  triple  salt  which  is  formed  by  the  pro- 
cess. In  the  old  pharmacopoeias  this  salt  was  known 
by  the  name  of  Tariari-z.ed  tincture  of  Mars. 

Fluale  of  polash. — ^This  salt  may  be  formed  by 
the  combination  of  pure  potash  with  fluoric  acid. 
Heat  is  given  out  on  the  mixture,  and  by  subsequent 
evaporation  the  salt  is  obtained.  It  is  deliquescent, 
and  very  soluble  in  water.  It  may  be  decomposed 
by  the  mere  addition  of  sulphuric  acid,  which  com- 
bines with  the  alkali  and  liberates  the  acid  in  the 
form  of  vapour. 

Gal/ate  of  polash. — The  properties  of  this  salt 
are  not  known. 

Hydrate  of  potash. — The  fixed  alkalies  contain 
a  considerable  portion  of  water,  even  after  they  have 
undergone  a  red-heat.  Hence  the  alkalies  of  com- 
merce are  always  in  tlie  state  of  hydrates.  The  hy- 
drate of  potash  consists  of 

I  proportional  of  [lolash  =  "15.0 

I       diito       ofwoU;r  =  8.5 


Hydrxodatc  of  potash  is  formed  by  dissolving 
carbonate  of  potash  in  hydriodie  acid.  Dr.  Thom- 
son has  stated  the  constituents  of  the  salt  to  be, 

Hydriodie  add 100.00 

Polaeli 38.09 


See  Gay-Lussac,  ylnnaks  dc  Chm'te,  xci.  p. . 


28  ON   THE   FIXED   ALKALIES. 

Hydroguretted  sulphui^i  of  potash. — This  salt- 
may  be  formed  by  mixing  flour  of  sulphur  with  a 
solution  of  hydro-siilphuret  of  potash,  and  digesting 
the  mixture  in  a  gentle  heat  Thus  an  adcUtional 
portion  of  sulphur  will  be  dissolved,  and  an  hydro- 
guretted sulphuret  of  potash  formed,  which  is  a  salt 
of  a  deep  yellow  colour,  with  a  very  pungent  and 

bitter  taste. 

HydrostUpkuret  of  potash  may  be  produced  by 
saturating  potash  with  sulphuretted  hydrogen.  The 
fluid  will  be  colourless  and  transparent,  and  on  eva- 
poration will  yield  crystals  not  unlike  those  of  sul- 
phate of  soda.  See  Vauquelin,  AnnaUs  de  Chimie^ 
tome  xlii.  page  40. 

Hyperoxymuriate  of  potash. — This  salt  is  the 
same  as  the  one  already  described  under  the  mcnre 
modern  name  of  Chlorate  of  potash. 

Hypophosphite  of  potash. — ^This  is  a  deliquescent 
salt,  very  soluble  either  in  water  or  alcohol  When 
submitted  to  heat,  phosphorus  and  phosphuretted 
hydrogen  escape,  and  the  salt  is  converted  to  phos- 
phate of  potash.  See  Dulong,  Annalesde  Chkme 
et  Phys.  tome  ii.  page  142. 

Hyposulphite  of  potash. — This  salt  is  prepared 
by  treating  hydrosulphuret  of  potash  with  liquid 
sulphurous  acid,  and  evaporating  the  solution  to  the 
point  of  crystallization.  On  cooling,  needle-formed 
crystals  are  produced,  which  have  a  bitter  taste,  and 
deliquesce  when  exposed  to  the  atmosphere. 

lodate  of  potash. — ^This  is  a  white  salt  in  very 
minute  crystals.    It  is  not  altered  by  the  air ;  but  if 


ON    THE    FIXEn    ALKALIES.  29 

heated  to  redness,  oxygen  gas  is  given  off,  and  iodide 
of  potassium  is  produced.  One  hundred  parts  of 
water  at  14^°  centr.,  or  57^°  of  Fahrenheit,  will  dis- 
solve 7.43  parts  of  this  salt.  Gay-Lussac,  Anjiales 
de  Chimie,  tome  xci.  page  74, 

Lactate  of  potash  may  be  obtained  by  satu- 
rating carbonate  of  potash  with  lactate  of  lime. 
The  salt  has  the  appearance,  when  the  water  is  abs- 
tracted by  evaporation,  of  a  yellowish  brown  gum 
of  a  soft  consistence.  It  is  soluble  in  heated  al- 
cohol. 

Malate  of  potash  is  a  deliquescent  salt,  and  so 
extremely  soluble  in  water  as  to  be  incapable  of 
crystalli2ing. 

Meconiaie  of  potash  forms  itself  in  four-sided 
tables,  which  are  soluble  in  two  parts  of  water  at 
60*,  and  composed  of 

Potash 60 

Meconic  acid 27 

WaWr  J3 


See  Brande's  Manual^  vol.  iii.  page  71. 

Mellate  of  potash  is  a  salt  which  crystallizes  in 
elongated  prisma.  By  a  further  addition  of  the 
acid,  a  supermellate  may  be  formed.  Vauquelin, 
Annates  de  Chimie,  tome  xxxvi.  page  209. 

Molybdatc  of  potash  may  be  formed  by  digesting 
molybdic  acid  in  a  solution  of  potash.  The  salt 
crj'stallizes  in  small  rhomboids,  running  into  one 
another.  These  are  soluble  in  hot  water  ;  but  the 
niolybdie  acid  may  be  precipitated  tlierefrom  by  the 


30  ON   THE   FIXKJ>   ALKALIES. 

addi^n  of  sulphuric  or  muriatic  add*  See^Abmahs 
de  Chmie^  tome  viii*  page  106f 

Muriaie  of  potash. — Tbi^  salt  is  in  fiict  af^hk^ 
ride  of  potassium,  consisting  of 

Potassium       .    •    # 37,5  ^ 

Chlorine 33^ 

71.0 

It  crystallizes  in  cubes  which  deliquesce  rapidly 
in  the  atmosphere.  It  was  formerly  called  Salt  of 
Sylvius,  and  Regenerated  sea-salt.  In  philosophic^ 
chemistry  it  is  very  much  employed  to  produce  ar* 
tificial  cold. 

Nitrate  of  potash^  or  what  is  usually  called  Salt<> 
petre,  is  produced  naturally  in  some  particular  di- 
stricts in  all  hot  countries :  but  that  which  is  con* 
sumed  here  is  chiefly  brought  from  the  East  Inches. 
It  crystallizes  in  hexagonal  prisms.  One  hundred 
parts  of  water  at  60^  dissolve  fourteen  parts  of  this 
salt,  and  boiling  water  dissolves  more  than  its  own 
weight.  This  salt,  according  to  Dr.  Wollaston, 
is  composed  of 

Nitric  acid 53^4 

Polash •   .    .    .     .    46.46 


100.00 

Nitrite  of  potash  is  a  salt  which  was  first  ob- 
served by  Scheele.  His  process  for  preparing  it  is 
to  fill  a  large  crucible  with  nitre,  and  keep  it  in  a 
red-heat  for  half  an  hour.  During  this  time  a  por- 
tion of  oxygen  escapes,  and  what  remains  in  the 
crucible  is  nitrite  of  potash,  a  salt  which  will  deli- 
quesce when  exposed  to  the  action  of  the  air. 


ON   THE   FIXED   ALKALIES. 


31 


Oxalate  of  potash. — This  salt  is  formed  by  dla- 
solving  potash  in  a  solution  of  oxalic  acid.  It  cry- 
stallizes in  flat  rhomboids,  soluble  in  three  parts  of 
water  at  60°.     It  is  composed  of 


) 


1  proportional  of  oxalic  acid        = 
1        ditto       ofpataeh  = 


35.5 
45,0 


Oxychlorate  of  potash,  which  is  a  very  insoluble 
salt,  crystallizes  in  elongated  octocdrons.  It  con- 
sists of 

I  proportional  of  oxyehloric  acid      ^     8(i 
1        ditto       ofpotasli  =     43 

It  is  unalterable  in  the  air,  and  possesses  no  bleach- 
ing properties  whatever. 

Ojcymuriate  of  potash. — The  same  as  the  salt 
which  Chenenx  named  liyijer-oxy muriate,  and 
which  lias  already  been  described  under  the  name  of 
Chlorate  of  potash,  which  see. 

Phosphate  of  potash. — ^This  salt  may  be  pro- 
duced by  adding  carbonate  of  potash  to  hot  phos- 
phoric acid  until  the  point  of  saturation  be  attained. 
If  the  solution  be  mucb  concentrated  and  then  suf- 
fered to  cool  gradually,  small  prismatic  crystals  of 
phosphate  of  potash  will  be  obtained,  consisting  of 
1  proportional  of  potiisli  ^     45 

1        ditto       of  phosphoric  acid      =     2G 

?1 
Pho-vphilc  of  potash. — Tliis  is  a  deliquescent  salt, 
incapable  of  crystallization.     Its  properties,  or  even 
its  component  parts,  nre  not  yet  known. 


32  ON   THE   FIXED   ALKALIES. 

Prussiaie  of  potash.' — This  salt' has  beeii  al- 
ready described  under  the  name  of  Ferrocyanaie  of 
potash.    See  page  26  of  this  volume. 

Quadro^alate  of  potash  was  discovered .  by  Dr. 
Wollaston.  When  the  Binoxalate  of  Potash  men- 
tioned at  page  23  is  digested  in  dilute  nitric  or  mu- 
riatic acid,  a  part  of  the  alkali  is  taken  up,  and  a  salt 
remains  consisting  of  four  times  as  much  oxalic  acid 
as  exists  in  oxalate  of  potash.     It  is  formed  of 

4  proportionals  of  oxalic  acid  35.5  x  4  =  142 
1        ditto         of  potash  =     45 

Sadactate  of  potash. — Scheele  has  treated, on 
this  salt  in  his  Essay  on  the  Sugar  of  Milk.  He  de- 
scribes the  salt  to  be  in  small  crystals  soluble  in 
eight  times  their  weight  of  water  at  212^. 

Silicate  of  potash  was  known  to  the  old  che- 
mists. It  may  be  prepared  by  fusing  three  parts 
of  good  potash  with  one  part  of  ground  silica,  both 
calculated  by  weight.  The  resulting  compound 
forms  a  kind  of  glass  on  cooling  which  is  soluble  in 

water.     The  solution  thus  formed  is  called  liquor 
silicwn. 

Sorbaie  of  potash. — ^The  sorbic  acid  was  disco- 
vered in  1815  by  Mr.  Donovan  in  the  juice  of  the 
berries  of  the  mountain  ash.  United  with  potash 
this  acid  forms  two  distinct  salts,  viz.  the  sorbate  of 
potash  which  is  incrystallizable,  and  the  bisorbate, 
which  gives  permanent  crystals  soluble  in  water, 
but  insoluble  in  alcohol. 

Subcarbonaie  of  potash. — ^This  salt  is  well  known 


ON    THE    FIXED    ALKALIES. 


33 


under  the  names  of  potash,  pearlash,  and  salt  of 
tartar.  It  consists  of  one  proportional  of  potash  = 
45+one  of  carbonic  acid=20.7. 

Suberate  of  potash  is  best  prepared  by  digesting 
suberic  acid  with  a  solution  of  crystallized  carbonate 
of  potash.  The  salt  crystallizes  in  prisms,  and  these 
are  very  soluble  in  water. — .'innales  de  Chimie, 
tome  xxiii.  page  51. 

Sultphosj)hate  of  potash. — ^This  salt  has  been 
formed  by  fusing  pure  potash,  with  the  phosphate  of 
this  alkali,  in  a  platinum  crucible.  It  is  either  a 
white  solid,  or  a  white  powder,  according  to  the 
mode  of  its  preparation.  Sanssurejun.  determined 
it  to  consist  of 


J'hosphor 


Succinate  of  potash  is  a  salt  which  crystallizes  in 
small  prisms,  deliquesces  in  the  air,  and  is  very  so- 
luble in  water.     Its  taste  is  saline  and  bitter, 

StUphate  of  potash. — This  salt,  which  is  the  same 
as  the  sal  de  duobus  of  the  old  chemists,  is  produced 
U  a  residuum  in  large  ({uantities  by  the  makers  of 
nitric  acid,  and  is  sold  under  the  name  of  sal eniantm. 
It  has  a  saline  bitter  taste,  and  when  dissolved  in 
water  crystallizes  for  the  most  part  in  short  six- 
sided  prisms,  terminated  by  hexangular  pyramids. 
It  is  composed  of  lUt)  sulphuric  acid+ 1 12,35  pot- 
uh^about  47  add  and  53  base.  See  Am 
Ckhnie,  tome  Ixxvii.  page  84, 

VOL.  II.  D 


de 


34  DN   THE   FIXED   ALKALIES. 

Sulphite  of  potash. — This  salt,  which  was  Cor- 
merly  known  by  the  name  of  the  sulphurous  salt  of 
Stahl,  may  be  formed  by  passing  sulphurous  acid 
gas  into  a  saturated  solution  of  very  pure  carbonate 
of  potash,  until  the  effervescence  entirely,  ceases. 
The  solution  becomes  warm  during  the  combinar- 
tion,  and  the  salt  crystallizes  on  cooling  in  the  fomi 
of  rhomboidal  plates.  These  by  exposure  to  tlie 
air  are  converted  to  sulphate  of  potash.  See  a  me- 
moir by  Fourcroy  and  Vauquelin  in  Nicholson*s 
Journal^  4 to,  vol.  i.  page  317* 

Sulphuret  of  potassium  is  formed  by  the  fusion 
of  a  mixture  of  sulphur  and  potash.  This  was  fop* 
merly  called  liver  of  sulphur,  and  consists  of 

1  proportional  of  potassium       =       Z7JS 
1       ditto  of  sulphur  =;        15.0 

52.5 

Superoxalate  of  potash. — This  salt  has  already 
been  described  under  the  name  of  binoxalate  of 
potash,  which  see. 

Superphosphate  of  potash. — ^The  same  as  the* 
biphosphate  described  at  page  23  of  this  volume. 

Supersulphate  of  potash. — ^This  salt  is  the  same 
as  the  one  already  described,  at  page  24,  under  the 
name  of  bisulphate  of  potash. 

Supertartrate  of  potash  is  the  same  as  the  bi- 
tartrate  mentioned  at  page  24,  and  commonly  known 
by  the  name  of  cream  of  tartar. 

Tartrate  of  potash  is  formed  by  adding  a  quan- 
tity of  potash  to  the  last-named  salt,  sufficient  to 


36  ON   THC   FIXED   ALKALIES. 

gins  to  liquefy,  it  decomposes  the  nitre  with  a  vi« 
olent  eflfervescenoe,  the  nitric  acid  is  driven  ofi^  and 
the  oxide  dissolves  in  the  potash.  The  mass  when 
cold  very  much  resembles  an  enamel.  It  dissolves 
in  boiling  water,  and  the  solution  on  cooling  depo- 
sits an  imperfectly  crystallized  white  powder.  This 
is  tellurate  of  potash.  It  has  a  slight  metalUc  taate, 
and  acts  feebly  as  an  alkali  on  vegetable  blues. 
— ^Tliomson,  vol.  ii.  page  665.  Berzelius,  Nichol- 
son*s  •loumalf  vol.  xxxvi.  page  130. 

TViple  prussiate  of  potash. — ^This  is  the  same 
as  the  ferrocyanate  of  potash  already  described. 

Thngsiate  of  potash  is  a  salt  which  may  be  pre- 
pared by  dissolving  the  oxide  of  tungsten  in  a  strong 
solution  of  carbonate  of  potash.  \Vh^i  this  satu- 
rated solution  is  concentrated  by  evaporation  a  white 
powder  falls  down,  which  is  the  tungstate  of  potash. 
This  salt  deliquesces  when  exposed  to  the  air,  and 
consequently  is  very  soluble  in  water. 

Urate  of  potash. — ^This  salt  is  stated  by  Dr. 
Thomson  to  be  a  white  powder  nearly  similar  to 
uric  acid  in  appearance  and  solubility.  It  is  also 
soluble  in  a  lye  of  caustic  potash. 

Zumate  of  potash. — ^Zumic  acid  is  obtained  by 
a  peculiar  process  from  rice.  It  was  first  desemb^ 
by  Braconnot,  but  the  name  which  it  now  bears 
was  given  by  Dr.  Thomson.  The  zumate  of  pot- 
ash is  a  deliquescent  salt,  incapable  of  crystalliza- 
tion, and  soluble  in  alcohol. — Awnales  de  Chimie, 
tome  Ixxxvi.  page  84. 


ON    THE    FIXED    ALKALIES.  liT 

The  Other  alkuli  of  which  we  have  to  treat,  is  soda, 
which  is  also  known  by  the  names  of  natron,  ba- 
rilla, mineral  alkah,  and  fossil  alkali.  This  sub- 
stance is  met  wltli  in  abundance,  and  even  used  for 
various  purposes,  in  China,  Persia,  in  the  environs 
of  Smyrna  and  Tripoli  *5,  and  in  general  all  over 
the  East,  as  well  as  on  the  northern  coast  of  Africa, 
in  Hungary,  and  Siberia.  It  likewise  occurs  in  the 
state  of  carbonate  of  soda  in  many  of  the  mineral 
waters  of  Germany  *6, 

Native  soda  is  also  found  in  large  cjuantities,  on 
tlie  surface  of  the  ground,  in  the  plains  of  the  Delta 
in  Egypt,  from  whence  it  is  brought  to  this  country 
under  the  name  of  natron.  It  occurs  likewise  in 
the  same  state  in  the  East  Indies,  and  in  the  islands 
of  Sicily  and  TenerifF.  These  islands  furnish  us 
also  with  a  large  quantity  of  soda,  in  the  form  of 
barillft,  which  is  chiefly  consumed  in  the  soap  trade, 
as  already  mentioned. 

Barilla  is  likewise  imported  in  very  considerable 
quantities  from  Spain.  This  is  made  by  the  in- 
cineration of  the  saLsola  soda,  a  marine  plant,  which 
18  so  highly  valued  by  the  Spaniards,  that  the  ex- 
portation of  the  seed  is,  by  the  law  of  the  country, 
punishable  with  death.     It  is  cultivated  with  great 


**  See  Hopaon's  Translation  of  Weigleb's  System  ofChana- 
"?.  page  103. 

•■  M.  Bngge,  Swedish  Consul  at  Tripoli,  has  published  a  par- 
ticnlai  account  of  the  way  in  which  native  soda  is  found.  See 
Mcmoiri  of  llie  Acadeiity  of  Stockholm,  torn,  .xxxiv.  page  140. 
An  account  of  the  mnnnerof  obtainiaj^lt  in  China  may  be  seen 
in  the  »aiiic  work,  torn,  ■x\-\'w.  pnge  170. 


38  ON   THE    FIXED    ALKALIES. 

care  in  the  neighbourhood  of  Alicant  and  Cartha- 
gena,  for  the  production  of  barilla ;  but  that  of 
Alicant  is  generally  the  most  esteemed. 

And  here  we  must  not  omit  to  mention  the 
manufacture  of  kelp,  upon  our  own  shores,  and 
which  is  so  considerable  as  to  furnish  the  English 
market  with  many  thousand  tons  of  soda  annually. 
The  manufacture  of  this  article  was  introduced  into 
the  Highlands  of  Scotland  about  the  year  )  730,  by 
a  gentleman  of  the  name  of  MacLeod,  who  brought 
the  art  of  cultivating  it  from  Ireland.  From  the 
year  1740  to  1760,  the  manufactured  kelp  was 
generally  sold  at  about  45^.  per  ton.  Since  then 
it  has  gradually  advanced  in  price  to  11/.  or  12/* 
per  ton. 

Since  the  manufacture  of  kelp  has  been  intro*- 
duced  into  the  Orkneys,  small  farms  of  forty  pounds 
a  year  have  risen  to  300/.  a  year  ^  ;  and  *'  it  is  said 
that  Lord  MacDonald  of  the  Isles  realizes  ten  thou- 
sand  pounds  a  year  from  his  kelp  shores  alone, 
which  his  ancestors  looked  upon  as  of  no  value 
whatever.  So  much  indeed  are  the  proprietors  of 
the  sea*coast  now  impressed  with  the  value  and 
importance  of  the  kelp  manufacture,  that  they  have 
found  the  means  of  producing  it  on  the  very  sands. 
They  place  stones  within  flood-mark  of  the  sea, 
which  are  soon  covered  with  ware^  as  it  is  com* 
monly  called,  and  which  is  the  vegetable  substance 
from  which  kelp  is  made^.** 

^  Jameson's  Account  of  the  Scottuth  Isles,  vol.  ii.  page  244. 
*®  Tradesman's  Magazine, 


r 

1  The  liritis 


ON    THE    riXEn    ALKALIES.  ',i9 

The  British  kelp  is  prepared  by  tlie  liurnitig  of 
various  plants  of  tlie  genus  of  the  salsola  of  Lin- 
neua,  (the  common  sea-wrack,)  and  similar  to  the 
.salsola  soda  of  the  Spaniards ;  but  the  article  which 
is  procured  from  these  plants  is  much  inferior  to 
barilla,  inasmuch  as  it  contains  a  large  portion  of 
neutral  salts,  a  quantity  of  potash,  and  a  much 
larger  proportion  of  carbonaceous  matter  than  is 
generally  found  in  the  former  articled. 

In  making  either  barilla  or  kelp,  the  weed  is  col- 
lected into  heaps  to  ferment ;  it  Is  then  spread  to 
dry  in  the  air,  and  is  afterwards  burnt  to  ashes  in 
ovens  made  with  brick  or  stone,  and  built  within 
the  ground.  By  increasing  the  heat,  the  alkali  in 
the  ashes  melts,  and  calcines  the  whole  into  one 
solid  mass.  When  cold,  it  is  broken  up  with  iron 
bars  into  large  ponderous  masses,  and  in  that  state 
it  is  Bent  to  market.  The  best  account  that  I  have 
teen  of  the  manufacture  of  kelp  is  in  Jameson's 
"Mineralogy  of  the  Scoitish  Isles  so ;"  and  in  a 
paper  by  Mr.  Beaton,  which  has  been  printed  in 
'/%e  Repertory  of  Arts  3',  from  tlie  Prize  Essays 
y  the  Highland  Society  of  Scotland^.  Some 
furtlier  information  may  be  obtained  from  Dr.  An- 


*  ¥oTU  new  explnnation  of  an  imporlimt  dilTerence  between 
kelp  find  bnriUa,  see  a  note  un'ler  the  article  "Alkaliei,"  in 
7^  Chemical  Catechkm,  tenth  edition,  p&ge  130,  131. 

'*  Quarto,  London,  vol.  ii.  page  2\A. 

"  Vol.  xii.  page  243. 

"  An  Bccount  of  the  kilns  which  nre  generally  made  use  of 
fw  the  manufacture  of  kelp,  may  be  seen  in  the  Transacliom  of 
the  tUghland  Soaety,  vul.  i.  page  24,  &c. 


40  ON   THE   FIXED   ALKALIES. 

derson*s  Account  of  the  Hebrides ;  and  from  my 
own  *^  Prize  Essay  on  Kelp  and  BariHa**  in  the  fifth 
volume  of  the  Transactums  of  the  Utghkmd  So^ 
ciety  of  Scotland^  pages  65 — 122. 

Here  it  will  be  proper  to  endeavour  to  correct  an 
error  which  the  purchasers  of  kelp  and  barilla  in 
general  labour  under.  It  often  happens  that  a  lot 
of  kelp  or  barilla  lies  a  long  time  in  the  merchant's 
warehouse^  until  by  the  action  of  the  air  the  greater 
part  of  the  large  lumps  fell  into  pieces^  which  gives 
the  whole  a  vQry  different  appearance  from  what  it 
had  at  the  time  of  importation. 

Whenever  I  have  had  occasion  to  examine  sudi 
a  parcel  in  company  with  the  buyers  of  the  artieie^ 
I  have  never  failed  to  observe  the  great  depredattoo 
in  price  which  such  a  lot  always  suffers  from  this 
circumstance.  I  have  seen  persons,  who  would  not 
buy  it  at  any  price ;  and  it  is  no  uncommon  thing 
for  people  to  refuse  a  very  valuable  parcel  of  this 
kind,  when  it  might  have  been  bought  considerably 
below  its  real  worth. 

Had  these  men  been  chemists,  they  would  have 
known  that  the  fixed  alkalies  are  imperishable^  and 
that  no  length  of  time  can  injure  them^  provided 
they  are  kept  in  a  situation  where  they  cannot  be 
dissolved  by  moisture,  or  washed  away  by  the 
rain. 

In  bargaining  for  such  alkalies,  a  chemist  would 
calculate  how  much  carbonic  acid  and  water  have 
been  absorbed  since  their  importation ;  and  then, 
having  made  that  deduction,  he  would  know  that 


42  ON   THE    FIXED    ALKALIES. 

Strong  phial  that  will  pour  well ;  some  litmus-paper 
of  both  kinds,  viz.  blue  and  red ;  a  bottle  of  the  so- 
lution of  muriate  of  platinum  ;  and  some  sulphuric 
acid  diluted  with  pure  water  until  it  be  reduoedt 
when  cold,  to  the  specific  gravity  of  1,100. 

Some  respectable  chemical  writers,  in  describing 
the  method  of  analysing  alkalies,  have  directed  ui 
to  take  a  given  portion  of  the  sulphuric  add  of 
commerce,  and  dilute  it  with  a  given  pcnrtioiiof 
water ;  but  as  the  sulphuric  acid  of  the  shops  variei 
very  much  in  strength,  it  is  impossible  by  this  iiie» 
thod  to  attain  accurate  results.  The  only  method 
that  can  be  depended  upon,  is  that  of  redudng  the 
acid  to  some  certain  specific  gravity.  That  whieh 
I  have  found  the  most  convenient,  is  the  specific 
gravity  of  1,100,  and  this  is  generally  attained  by 
mixing  about  six  parts  of  water  with  one  part  of 
the  best  oil  of  vitriol  of  commerce,  both  fo  be  es>- 
timated  by  weight  and  not  by  measure. 

When  any  parcel  of  kelp  or  barilla  is  to  be  ex* 
amined,  it  will  be  proper  to  select  as  fair  an  average 
sample  as  possible.  This  can  only  be  done  by 
taking  several  lumps  from  differejit  parts  of  the 
heap,  by  breaking  a  small  piece  from  each  of  these 
lumps,  and  mixing  them  with  a  fair  prq>ortioii  of 
the  small  which  may  belong  to  the  lot.  The  sam* 
pie  should  then  be  pulverized  in  an  iron  mortar» 
that  the  whole  may  be  more  completely  mixed; 
and  a  small  quantity  of  this^  say  about  an  ounce, 
should  be  returned  into  the  mortar  and  ground  to 
an  impalpable  powder,  that  the  alkali  may  be  dis- 


ON    THE    FIXED    ALKALIES.  -4^ 

solved  out  of  it  with  greater  ease  and  certainty. 
Things  bting  thus  prepared,  the  aniilysis  is  to  be 
proceeded  with  in  the  following  manner: 

Take  the  weight  of  one  hundred  grains  of  the  al- 
kaline powder,  put  it  into  a  convenient  vessel,  and 
pour  over  it  a  two-ounce  measure  of  pure  water. 
Stir  the  mixture  with  a  piece  of  glass,  repeating  it 
DOW  and  then  during  the  space  of  a  few  hours. 
When  the  insoluble  matter  has  been  suffered  to 
subside,  pour  the  supernatant  liquor  upon  a  paper 
filter,  and  add  another  measure  of  water  to  the  re- 
siduum, which  should  be  well  stirred  once  or  twice, 
and  then  be  suffered  to  remain  as  before.  It  is  ne- 
cessary to  attend  to  the  circumstance  of  filtrating 
the  solution  :  otherwise  there  might  be  a  portion 
of  lime  or  carbonate  of  Ihne  in  it,  which  would  ab- 
sorb part  of  the  acid  employed  in  the  analysis,  and 
occasion  an  inaccurate  result.  When  this  lixivium 
lias  been  thus  filtrated,  the  residuum  itself  should 
be  put  upon  the  filter,  and  small  portions  of  water 
poured  over  it  occasionally,  until  the  water  passes 
through  it  devoid  of  taste  and  colour. 

These  solutions  are  now  to  be  mixed,  and  put 
into  a  convenient  vessel,  in  which  they  should  boil 
until  the  whole  is  reduced  to  about  two  or  three 
ounces,  when  it  will  be  sufficiently  concentrated  for 
the  examination,  which  should  be  conducted  in  the 
following  manner : 

Take  about  two  ounces  of  diluted  sulphuric  acid, 
aaabovemenlioned,  of  the  specific  gravity  of  1,100; 
and  having  weighed  it  accurately,  together  with  the 


44  ON   THE    FIXED    ALKAUE9. 

phial,  note  down  the  united  weight  of  both  in  grains. 
Then  pour  a  portion  of  the  acid  very  gradually  into 
the  alkaline  solution,  and  stir  it  well  with  a  ghtt 
rod,  till  the  effervescence  occasioned  by  the  escape 
of  the  carbonic  acid  has  ceased. 

A  slip  of  the  reddened  litmus-paper  should  bow 
be  dipped  into  the  solution ;  and  if  this  becomi^ 
blue,  it  shows  that  the  liquid  still  contains  alUBy 
and  that  more  acid  must  be  added.  In  the  hepih 
ning  I  generally  put  one  drachm  in  measure  of  the 
diluted  acid  to  the  lixivium  after  every  trial  with  the 
test  paper.  This,  however,  must  now  be  done  cau- 
tiously, taking  care  to  stir  the  mixture  well  aflter 
every  addition  of  the  acid. 

When  the  effervescence  becomes  less,  and  the 
test  paper  receives  only  a  slight  blue  tinge  by  im- 
mersion in  the  lixivium,  the  add  should  be  added  still 
more  gradually,  and  by  a  very  few  drops  at  a  time, 
that  no  more  acid  may  be  employed  than  is  abac- 
lutely  requisite  for  the  complete  saturation  of  the 
alkali ;  which  may  be  known  by  the  cessation  of  the 
effervescence,  the  unchangeable  appearance  of  the 
test  paper  on  immersion,  and  the  separation  of  the 
sulphur  which  was  held  in  solution  by  the  alkali, 
and  which  separates  when  the  alkali  becomes  satu- 
rated with  an  acid. 

The  alkali  having  been  in  this  way  rendered  neu- 
tral, the  reminder  of  the  acid  with  its  phial  is  to' be 
weighed  again,  to  ascertain  how  much  of  the  £luted 
sulphuric  acid  has  been  consumed ;  and  this  will 
show  the  precise  quantity  of  real  alkali  which  b 


ON   THE    FIXED    ALKALIES. 


45 


contained  in  tlie  SEtmple  under  examination,  when 
it  is  known  how  much  acid  an  alkali  in  a  state  of 
purity  is  capable  of  taking  up. 

In  order  to  provide  a  scale  for  calculating  this,  I 
took  100  grains  of  dry  potash  purified  by  means  of 
alcohol ;  and  having  treated  it  with  the  diluted  sul- 
phuric acid  of  tlie  specific  gravity  of  1,100, 1  found 
that  it  required  exactly  520  grains  of  the  acid  to 
saturate  it.  In  like  manner  I  treated  pure  soda ; 
but  100  grains  of  this  alkali  rccjuire  812  grains  of 
acid  of  the  same  strength  for  its  saturation. 

These  results  being  considered  as  the  basis,  it  is 
easy,  by  the  rule  of  proportion,  to  calculate  how 
much  real  alkali  there  is  in  any  sample  of  kelp,  na- 
tron, or  barilla,  by  the  weight  of  acid  required  to 
saturate  it. 

But  as  the  two  alkalies  combine  with  different 
portions  of  acid,  the  analysis  cannot  be  accurate  un- 
less it  be  ascertained  whetlier  the  alkali  in  tlie  sam- 
ple be  soda  only,  or  a  mixture  of  soda  and  potash  ; 
and,  if  it  be  of  tlie  latter  kind.  In  what  relative  pro- 
portions these  alkalies  exist. 

Tlie  most  useful  test  in  this  case  is  the  liquid 
muriate  of  platinum,  made  by  dissolving  the  cry- 
stals of  that  salt  in  pure  water  ;  for,  if  a  drop  of  this 
reagent  be  added  to  a  small  quantity  of  any  alkaline 
solution,  a  yellow  precipitate,  which  is  a  triple  com- 
pound of  potash,  oxide  of  platinum  and  muriatic 
acid,  will  appear  if  tliealkalicontain  potash;  where- 
as, if  it  be  a  solution  of  soda  only,  no  precipitate 
will  occur.     If  the  alkali  under  examination  should 


46  ON   TH£   FIXED   ALKALIES. 

contain  nmriate  of  potash,  (which,  however,  vary 
rarely  occurs,)  this  would  likewise  produces  pre^ 
cipitate,  and  might  occasion  deceptkw ;  for'the 
muriate  of  platinum  detects  all  the  smks  of  potHsb 
as  well  as  pure  potash.  Should  a  sample  be  tn^ 
pected  to  contain  this  salt,  a  small  portion  of  the 
Uxivium  might  be  supersaturated  with  sulphuric 
acid,  by  which  means  the  muriatic  acid  would  be 
driven  off  and  easily  detected  by  its  peculiar  smdly 
or  by  presenting  ammoniacal  gas  ;  and  the  potarii, 
in  the  form  of  sulphate,  would  be  separated  by  its 
crystallizing  before  the  sulphate  of  soda. 

There  are  several  other  methods  by  which  IIms 
fixed  alkalies  may  be  distinguished  from  each  other^ 
These  are  alt  described  in  The  ChemiccU  Catechimm^ 
tenth  edition,  page  1 27,  &c.  The  use  of  muriate 
of  platinum  has  often  been  stated  to  be  a  new  me- 
thod of  detecting  potash ;  but  in  justice  to  the  me« 
mory  of  Margraff  it  ought  to  be  known,  that  he 
pointed  it  out  for  this  especial  purpose  more  thm 
seventy  years  ago  3*. 

Soda  in  its  pure  state  is  very  similar  in  the  caoe* 
tici^  of  taste  to  that  of  potash  ;  though  in  its  usual 
condition  it  does  not  so  readily  absorb  water  from^ 
the  atmosphere  ;  on  the  contrary,  its  crystals  effloi- 
resce,  and  entirely  lose  their  water  of  crystallization 
by  such  exposure.  If,  however,  pure  soda  be  ren« 
dered  very  dry  and  then  moistened  with  water,  it  witt 
absorb  the  water  with  avidity,  and  heat  will  be  given 

'*  See  Macquer*R  Chemical  Dictionary,  the  article  Alkali. 


ON   THE    FIXED    ALKALIES.  4T 

out  during  this  absorption,  owing  to  llie  water  be- 
coming actually  solidified  by  the  alkali. 

Although  soda  is  ao  analogous  to  potash  in  many 
of  its  habitudes,  that  it  can  only  on  certain  occa" 
sions  be  distinguished  by  chemical  tests,  yet  the  ac- 
tion of  these  two  alkalies  in  some  manufactures, 
and  the  combinations  they  fortik,  are  so  dissimilar, 
that  we  are  under  the  necessity  of  considering  them 
to  be  perfectly  distinct  bodies. 

The  most  remarkable  difference  in  the  effects  of 
these  nlkalies,  when  employed  in  manufacturing 
processes,  is  in  the  articles  of  soap  and  glass.  In 
that  of  glass,  the  mineral  alkali  more  easllv  com- 
bines with  the  silica ;  consequently  the  frit  is  formed 
with  greater  facility  and  certainty.  It  has  also  been 
s&id  tliat  soda  produces  a  glass  of  greater  hardness  : 
but  of  this  there  is  some  doubt. 

In  the  manufacture  of  common  hard  snap,  soda 
is  an  essential  ingredient.  Pure  potash  will  also 
combine  with  oil  or  tallow,  and  form  a  complete 
soap ;  and  it  is  by  this  alkali  that  all  the  so/i  soap  is 
made  which  Is  prepared  in  Great  Britain.  But  if 
more  than  a  certain  proportion  of  potash  be  used 
in  the  manufacture  of  hard  soap,  although  the  soap 
might  have  sufficient  consistence,  and  appear  per- 
fectly good  when  finished,  its  character  would  be 
entirely  changed  the  first  day  of  its  exposure  to  the 
action  of  the  air  in  dump  weatiier  ;  for  it  would  tlien 
become  soft,  flexuous,  and  unsaleable.  Great  losses 
were  formerly  sustained  by  many  manufacturers  of 
soap,  from  their  ignorance  of  this  circumstance. 


48  ON  THB   FIXED   ALKALIES. 

However,  if  this  imperfect  soap  be  dissolved  in  hot 
water,  and  brought  to  a  boiling  heat,  and  wbSit 
boiling,  a  sufficient  pordon  of  common  salt  be  add- 
ed, the  moment  these  substances  come  in  contact 
with  each  other,  the  potash  will  quit  the  tallow  to 
unite  with  the  muriatic  acid  of  the  salt,  and  the 
soda  will  then  supply  its  place,  and  combine  with  the 
tallow,  so  as  to  form  a  hard,  firm  and  saleable  soap.  • 

Having  already  given  some  account  of  the  salts 
of  potash,  it  will  now  be  proper  to  notice  the  prin- 
cipal salts  which  have  been  formed  by  means  of  so- 
da. These  may  frequently  be  known  from  the  for- 
mer by  their  greater  degree  of  solubility  in  wateft 
andby  their  containing  much  water  of  crystallizatioiiy 
though  to  this  there  are  some  exceptions.  They 
may  also  be  distinguished  from  the  salts  of  potash  by 
their  yielding  no  precipitate  when  treated  with  tarta- 
ric acid  or  with  a  solution  of  muriate  of  platinum. 

Acetate  of  soda. — ^This  salt  was  known  in  the  old 
pharmacopoeias  by  the  name  of  cfystallized  JbUated 
earth*  It  crystallizes  in  prisms  similar  to  sulphate 
of  soda;  but  these  cannot  be  obtained  unless. the 
solution  contains  an  excess  of  soda.  It  consists  of 
29.5  soda-f-48  acetic.acid. 

Arsemate  of  soda. — This  salt  differs  from  ar- 
seniate  of  potash,  inasmuch  as  it  crystallizes  in  six- 
sided  prisms;  whereas  the  latter  is  incapable  dP 
crystallization.  If  there  be,  however,  an  excess  of 
acid  in  the  solution,  the  arseniate  of  soda  will  not 
crystallize. 


ON   THE    FIXED    ALKALIES. 


■49 


Arsenile  of  soda. — This,  like  the  arseiiite  of  pot- 
ash, is  incapable  crystallization,  being  a  thick  yellow 
liquid,  with  an  odour  that  is  peculiarly  nauseous. 
I'his  salt  is  decomposable  by  heat,  and  the  aiseni- 
0U8  acid  escapes  in  vapour.  According  to  Professor 
Brande-''*,  the  srsenite  of  soda  is  a  compound  of 

I  proportional  ofarsenious  acid      =s      54 
I  ditto  of  !<oda  =      32 


Benzoate  of  jorfa.— Unlike  its  correspondent 
salt  of  potash,  which  is  deliquescent,  this  salt  efflo- 
resces  in  the  atmosphere,  but  its  taste  is  similar, 
and  it  is  also  very  soluble  in  water.  Ilie  crystals 
likewise  are  considerably  larger  than  the  crystals  of 
benzoate  of  potash. 

Bicarbonate  of  soda. — This,  like  the  bicarbonate 
of  potash,  may  be  prepared  by  passing  a  stream  of 
carbonic  acid  gas  into  a  solution  of  the  soda  of  com- 
merce. This  process  produces  a  solid  mass  of  the 
salt,  which  when  dried  is  usually  pulverized  for  sale. 
If  the  bicarbonate  of  soda  be  exposed  to  a  red-heat, 
it  will  lose  exactly  one-half  of  its  carbonic  acid,  and 
thereby  be  reduced  to  common  carbonate  3^.  It 
may  be  observed,  that  this  suit  is  found  native  in 
some  parts  of  Africa  in  considerable  quantities,  and 
has  been  imported  into  this  country,  and  sold  under 
the  name  of  trona.  There  is  a  process  in  the  Lon- 
don Pharraacopteia  for  preparing  this  bicarbonate, 

"  Table  of  prime  equivalent  iminbcra,  pfige  12.  ^ 
'"  IVoliiwton,  Philo*.  Tram.  1808. 


do  '*     ON   THE   FIXED   ALKALIES. 

by  treating  the  carbonate  of  soda  with  carbonate  of 
ammonia,  which  see. 

Borate  of  soda  is  readily  formed  by  saturating 
common  borax  with  the  boracic  acid ;  borax  itself 
being  a  sub-borate  of  soda.  According  to  Berg^ 
man,  two  pounds  of  borax  will  require  one  ppQiid 
of  boracic  acid  for  its  saturation. 

Camphorate  of  soda  is  similar  to  camphorate  of 
potash  in  most  of  its  properties,  and  may  be  formed 
in  the  same  manner.  Its  crystals  are  in  irregular 
forms,  but  they  may  be  obtained  very  white  and 
transparent.  If  submitted  to  heat,  the  acid  bums 
with  a  beautiful  blue  flame  at  the  firsts  and  after- 
wards with  one  of  a  purple  hue.  In  the  year  1798 
Mons.  Bouillon  Lagrange  read  an  Essay,  before  the 
Philomathique  Society  of  Paris,  on  the  propertiea 

of  the  camphoric  salts^  and  the  method  of  preparing 
them  37. 

Carbonate  of  soda.  This  salt,  which  is  era- 
ployed  in  large  quantities  in  the  manufactures  of 
the  country,  is  usually  produced  from  three  distinct 
sources,  viz.  from  the  barilla  of  Spain  and  Sicily, 
from  the  kelp  which  is  made  on  our  own  shores, 
and  from  a  native  production  which  is  brought  from 
Egjrpt  under  the  name  of  natron.  It  crystallizes 
in  octohedrons,  with  a  rhombic  base,  forming  a  so- 
lid with  ten  faces.     The  dry  salt  consists  of 

Soda 29.5 

Catbonic  acid 2Xi,7 

3^  Annales  de  Chimie,  xxvii.  pages  19—41. 


ON  THE   FIXED   ALKALIES.  51 

The  ciystallized  salt  consists  of 

Carbonate  of  soda 50.2 

7  waters 8.5  x  7  s  59.5 

109.7 

• 

Ckromate  of  soda  is  a  crystallizable  salt  of  an 
orange  colour.  If  a  solution  of  chromate  of  soda 
be  added  to  a  soludon  of  lead,  copper,  iron,  mer- 
€tiiy»  or  silver,  it  forms  an  insoluble  precipitate, 
varying  in  colour  according  to  the  nature  of  the 
metallic  solution  into  which  it  is  poured.  In  the 
sohitions  of  zinc,  tin,  and  some  other  metals  it 
forms  no  precipitate^. 

CUrate  of  soda, — ^This  salt  agrees  in  several  of 
its  properties  with  citrate  of  potash.  It  crystallizes 
in  hexahedral  tables,  and  is  soluble  in  two  parts  of 
water»at  56^  and  effloresces  when  exposed  to  the 
air.  It  is  considered  by  Vauquelin  to  be  composed 
of 

Citric  add 60.7 

Soda 39^ 

100.0 

Mr.  Brande  makes  it  to  consist  of 

1  proportional  of  citric  acid       =s       55.5 
1        ditto        of  soda  ss       29.5 

85.0 

Fluate  of  soda  is  formed  by  pouring  a  solution 
of  pure  soda  into  fluoric  acid.    The  salt  crystallizes 

on  cooling.     It  has  less  taste  than  fluate  of  potash, 

—  -  -  -  -     .    ■  ■  .  ■     . .  ,   ■  ■— ».^— ^-^ — ^^-^-1 — «^^ 

*  See  John,  AtmaU  of  PhUosopky,  voL  it.  page  425. 

e2 


52  ON   THE    FIXED   ALKALIES. 

and  is  not  altered,  like  that  salt,  by  exposure  to  the 
air. 

Hydrate  of  soda  is  a  compound  of  caustic  soda 
and  water.  Though  this  alkali  be  purified  as  much 
as  possible  by  lime  and  alcohol,  and  afterwards  by 
fusion,  it  will  still  contain  a  portion  of  water.  It 
consists  of  29.5  protoxide  of  sodium-}- 8.5  water. 

Hydrosulphuret  of  soda  crystallizes  in  four-sided 
prisms,  terminated  by  quadrangular  pyramids.  Its 
taste  is  intensely  bitter,  though  the  crystals  are  trans- 
parent and  colourless.  It  is  very  soluble  in  water, 
and  deliquesces  in  the  air,  during  which  process  the 
solution  acquires  a  green  colour. 

For  some  account  of  the  formation  of  this  salt, 
see  the  article  sulphuret  of  soda. 

lodate  of  soda.— 'This  salt  has  been  formed  and 
examined  by  Gay  Lussac.  It  may  be  made  by  dis- 
solving iodine  in  a  solution  of  pure  soda.  It  forms 
itself  in  small  prismatic  crystals. — Annales  de  Chi" 
mie^  tome  xci. 

Lactate  of  soda, — ^This  salt  is  very  similar  to 
lactate  of  potash.  It  has  been  examined  by  Ber- 
zelius,  who  thinks  the  two  salts  can  only  be  distin- 
guished by  analysis. 

Malate  of  soda. — ^This  salt  is  uncrystallizable, 
^ery  soluble  in  water,  and  deliquescent  in  the  at- 
mosphere. 

Molybdate  of  soda  agrees  with  molybdate  of  pot- 
ash in  many  of  its  properties ;  but  it  is  more  soluble 
in  water,  and  affords  transparent  crystals,  which  are 
unalterable  by  exposure  to  the  atmosphere. 


OK  THE.  FIXED   ALKALIES;  53 

Muriate  of  soda  is  one  of  the  most  abundant 
salts  in  nature.  It  is  the  chief  ingredient  in  sea*^ 
water,  it  abounds  in  salt  springs  in  most  parts  of 
the  world,  and  is  found  in  immense  masses  in  the 
county  of  Chester  in  the  form  of  rock- salt.  A  va« 
luable  paper  by  Dr.  Henry  on  the  various  kinds  of 
common  salt,  will  be  found  in  the  Philosophical 
Transactions  for  181 0,  page  89,  &c. 

When  pure  it  consists  of  22  sodium  -f-  33.5 
chlorine. 

Nitrate  of  soda  is  the  cubic  nitre  of  the  old  che- 
mists. It  forms  itself  in  rhombic  crystals,  which  re- 
quire three  parts  of  water  at  60^  for  their  solution. 
It  has  in  a  slight  degree  the  property  of  deliques- 
•eence,  and  is  soluble  in  less  than  its  own  weight  of 
water  at  2 12^     It  is  a  compound  of 

Soda 29.5 

Nitric  acid 50.5 

80. 

Dr.  Lewis  has  treated  at  length  on  the  nature  of 
this  salt  39. 

Oxalate  of  soda  is  a  salt  which  appears  in  small 
crystals  like  grains  of  sand.  This  salt  dissolves  in 
cold  water  with  difficulty,  but  is  perfectly  soluble  in 
hot  water.  Its  taste  is  cooling  and  bitter,  and  it 
falls  to  powder  when  submitted  for  some  time  t9a 


*  Philosophical  Commerce  of  the  ArtSj  page«  6^^646. 


54  ON  THE   FIXED   ALKALIES. 

gentle  heat.    According  to  Prbfessor  Brande  ^,  it 
consists  of 

1  proportional  of  oxalic  acid       ss      35.5 
1       ditto       of  soda  =       29.5 


65.0 

Vogel  of  Bayreuth  makes  this  salt  to  consist 
of 

Oxalic  acid 54.77 

Soda 45.23 


100.00 

Phosphate  of  soda, — ^This  is  the  salperlatum  d 
the  old  chemists.  It  possesses  a  very  mild  saline 
taste^  and  on  this  account  was  introduced  into  the 
practice  of  medicine  by  Dr.  George  Pearson.  It 
consists  of 

Soda 293 

Phosphoric  acid 26.0 

55.5 

When  crystallized,  the  proportions  are  very  diffe- 
rent, as  the  crystals  contain  more  than  half  their 
weight  of  water.  These  are  often  used  in  the  arts 
as  a  metallic  flux. 

Phosphite  of  soda. — ^The  properties  of  this  salt 
are  not  much  known.  It  has,  however,  been  seen 
that  the  hjrpophosphite  of  soda  is  very  soluble  both 
in  water  and  in  alcohol.  Annales  de  Chimie  et 
Phys.  tome  ii.  page  142. 

^^  Manual  of  Chemistry,  vol.  iii.  page  348. 


ON   THE    KIXEU    ALKALIES.  Si) 

Silieale  of  soda. — This  salt  may  be  formed  in 
the  same  way  as  silicate  of  potash,  with  the  sub- 
stitation  of  the  mineral  for  the  vegetable  alkali. 
Glass  is  a  siipersillcate,  cotitaining  a  considerable 
excess  either  of  potash  or  soda.  See  the  Essay  on 
the  Manufacture  of  Glass,  in  this  voUmie. 

Subborate  of  soda  is  brought  from  the  East  In- 
dies in  a  very  impure  state,  and  sold  under  the  name 
of  tincal.  Formerly  none  but  the  Dutch  were  ca- 
pable of  purifying  it ;  but  now  this  is  well  done 
both  in  France  and  in  England,  and  when  purified 
is  called  borax.  The  crystals  are  irregular  Iiexen- 
gular  prisms,  which  are  slightly  efflorescent.  These, 
according  to  Bergman,  are  composed  of 

flomt-ic  acid .f  4 

Sodu 17 

Water 49 


Borucic  acid  is  usually  procured  from  this  salt 
by  the  affHsion  of  sulphuric  acid ;  but  its  chief  con- 
sumption is  as  a  flux,  and  by  the  braziers  for  solder. 

Suberale  of  soda. — This  salt  difi'ers  from  the 
suberate  of  potash  chiefly  in  the  circumstance  of  its 
being  incapable  of  crystallization ;  whereas  suberate 
of  potash  crystallizes  in  prisms.  The  best  account 
we  have  of  these  salts  will  be  found  in  a  copious 
extract,  in  the  Annales  de  Chimic,  from  a  memoir 
on  cork,  and  on  the  combinations  of  its  acid,  read 
to  the  Institute  of  Paris  by  Bouillon  I^a  Grange*'. 


56  ON   TH£   FIX£P   AL|LAL1£S. 

Succinate  of  soda. — ^This  salt  differs  in  several 
respects  from  succinate  of  potash.  It  crystallizes 
in  hard  transparent  four-sided  and  hexagonal  prisms, 
which  are  unchangeable  in  the  air ;  whereas  the  sue* 
cinate  of  potash  is  extremely  soluble,  is  crystallized 
with  difficulty,  and  the  salt,  which  is  in  the  form  of 
very  small  prisms,  readily  deliquesces  in  the  atmo- 
sphere. 

.  Sulphate  of  soda. — ^This  is  the  std  mirabUe  of 
the  old  chemists,  and  has  been  long  known  in  this 
country  under  the  name  of  Glaubers  salt.  It  usu- 
ally crystallizes  in  large  four-sided  prisms,  hard  and 
transparent ;  hut  they  effloresce  when  exposed  long 
to  the  atmosphere,  and  fall  into  powder.  Sulphate 
of  soda  is  produced  in  considerable  quantities  by  the 
makers  of  muriatic  acid.     It  is  composed  of 

1  proportional  of  acid  s=  37^ 

1       ditto         of  soda  =  29^ 

67.0 

or. 

Sulphuric  acid 56 

Soda _44 

100 

When  crystallized  it  consists  of 

Dry  sulphate  of  soda 67 

Water 85 

T52 

Sulphite  of  soda.  This  is  a  crystallizable  salt, 
not  quite  so  soluble  as  the  sulphate  of  soda.  It 
consists  of 

1  proportional  of  sulphurous  acid    ss  30.0 
I        ditto        of  soda  =:  29.5 


ON  THE.  FIXED  ALKAi.l£8;  5?. 

The  crystals  are  composed  of  one  proportional  of 
the  salt  and  eight  proportionals  of  water  ^. 

Sulphuret  of  soda* — ^Wben  sulphur  and  soda  are 
fused  together,  a  red  compound  is  formed,  whose 
taste  is  bitter  and  otherwise  disagreeable.  This  is 
sulphuret  of  soda.  For  an  account  of  its  nature 
and  properties,  see  Vauquelin,  Amiales  de  Chimiey 
tome  xli.  page  190.  When  this  sulphuret,  which 
is  very  deliquescent,  is  dissolved  in  water,  it  pro*' 
duces  a  yellow  solution  of  hydrosulphuret  of  soda. 

Supertartrate  of  soda  is  readily  obtained  by  add* 
ing  tartaric  acid  to  a  solution  of  tartrate  of  soda. 
Tbenard  has  treated  upon  this  salt.  See  Annates 
de  Chimie^  tome  xxviii.  page  12. 

Tartrate  of  soda.  This  salt  may  be  formed  by 
the  direct  union  of  tartaric  acid  and  soda*  It  19 
composed  of 

1  proportional  of  tartaric  acid      =s       62^ 
1        ditto       of  soda  =       29.5 


92.0 

It  crj^tallizes  in  needle-formed  crystals,  which  are 
much  more  soluble  in  water  than  the  tartrate  of 
potash. 

Tungstate  of  soda.  This  salt  differs  much  from 
the  tungstate  of  potash  already  described,  as  it 
ciystallizes  in  solid  elongated  hexahedral  tables  ; 
whereas  the  latter  is  incapable  of  crystallization,  and, 
when  concentrated  as  much  as  possible,  deliquesces 

♦•  Dr.  Tliorason,  vol.  ii.  page  449. 


58  ON  THE   FIXED   ALKALIES. 

by  exposure  to  a  damp  atmosphere.  Tungstate  of 
soda,  which  may  be  prepared  by  dissolving  tungstie 
acid  in  a  solution  of  soda,  is  soluble  in  four  parts  of 
cold,  or  two  parts  of  boiling  water.  Vauquelin  and 
Hecht  have  investigated  the  nature  of  the  salts 
formed  with  tungstie  acid  ^. 

Urate  of  soda.  This  salt  is  in  the  form  of  a 
white  powder,  having,  according  to  Dr.  Thomson, 
the  same  appearance  as  pure  uric  acid  ^.  It  is  so* 
luble  in  a  lye  of  caustic  soda. 

It  had  for  many  years  been  usual  to  consider  the 
fixed  alkalies  to  be  simple  undecomposable  bodies; 
but  when  the  present  modes  of  chemical  analysis 
were  adopted,  it  was  soon  suspected  that  soda  and 
potash  would  ultimately  be  found  to  be  compound 
substances.  Morveau  had  long  ago  published  an 
opinion  that  the  fixed  alkalies  were  not  simple  sub- 
stances ;  and  in  the  first  edition  of  T7te  Chemical 
Catechism^  printed  in  the  year  1806,  I  fully  ex- 
pressed my  opinion  of  the  compound  nature  of  these 
bodies.  In  the  year  1807  a. very  important  paper 
was  read  by  Sir  Humphry  Davy  before  the  Royal 
Sodety,  on  the  agencies  of  galvanism  in  the  decom- 
position of  a  variety  alkaline  and  earthy  salts.  The 
experiments  which  he  detdled  in  that  paper  were 
sufficient  to  produce  an  alteration  in  all  our  former 
ideas  of  chemical  affinity,  as  they  proved  decisively 


*^  Journal  des  Mines,  No.  xix.  page  80. 
<*  System  of  Chemistry,  vol.  ii.  page  454. 


ON  THE  FIXED  ALKALI £8.  59 

that  the  formation  of  all  chemical  compounds  may 
depend  on  the  electrical  state  of  the  materials  of 
which  they  are  composed.  Soon  afterwards,  by 
means  of  the  large  galvanic  apparatus  at  the  Royal 
loititution,  this  philosopher  was  enabled  to  decom* 
pose  the  fixed  alkalies,  and  to  exhibit  their  metallic 
bases  in  an  insulated  and  separate  state. 

It  was  on  the  19th  day  of  November,  in  the  year 
1809,  that  Sir  Humphry  Davy,  in  a  paper  read 
before  the  Royal  Society,  announced  that  he  had 
soooeeded  in  his  attempts  to  decompose  these  bo- 
diet.— -Of  so  much  consequence  are  these  disco* 
vtries,  and  so  very  interesting  is  the  paper  which 
details  them,  that  I  am  sure  I  shall  be  expected  in 
aD  Essay  on  the  fixed  alkalies  not  to  withhold  such 
an  abridgement  of  it,  as  will  give  the  reader  a  cor* 
feet  idea  of  the  important  matter  which  it  contains^ 
and  also  of  the  several  circumstances  which  were 
connected  with  discoveries  which  are  in  themselves 
as  truly  valuable  as  they  are  brilliant  and  original. 

In  the  first  attempts  which  Sir  Humphry  Davy 
made  for  the  decomposition  of  the  fixed  alkalies,  he 
entirely  failed,  in  consequence  of  his  having  acted 
upon  their  aqueous  solutions.  He  afterwards  used 
potash  in  the  state  of  igneous  fusion,  and  acted  upon 
it  by  an  electrical  power,  which  was  produced  firom 
a  galvanic  battery  of  1 00  plates,  of  6  inches  square, 
highly  charged. 

Here  some  brilliant  phenomena  were  produced. 
A  most  intense  light  and  a  column  of  flame  were 
exhibited,  which  seemed  to  be  otving  to  the  deve- 


60  ON  THE   FIXED   ALKALIES. 

lopment  of  combustible  matter ;  and  when  the  or* 
der  was  changed,  so  that  the  alkali  was  brought  ia 
contact  with  the  negative  side  of  the  battery,  a6ri* 
form  globules,  which  inflamed  in  the  atmosphere^ 
rose  through  the  potash.  Being,  however,  unaUe 
to  collect  the  products  of  decomposition  by  this 
means,  he  had  then  recourse  to  pure  potash  in  its 
usual  state,  and  depended  on  electricity  alone  for 
Its  fusion,  as  well  as  its  decomposition. 

A  small  piece  of  pure  potash,  moistened  a  little 
by  the  breath,  was  placed  upon  an  insulated  disc  of 
platinum,  connected  with  the  negative  side  of  a 
battery  consisting  of  100  plates  of  6  inches  and  loO 
of  4  inches  square,  in  a  state  of  intense  activity, 
and  a  platinum  wire,  communicating  with  the  po* 
sitive  side,  was  brought  in  contact  with  the  upper 
surface  of  the  alkali.  Under  these  circumstances  % 
vivid  action  soon  commenced.  The  potash  began 
to  fuse  at  both  its  points  of  electrization,  and  small 
globules  having  a  high  metallic  lustre,  and  precisely 
similar  in  visible  characters  to  quicksilver,  appeared, 
some  of  which  burnt  with  explosion  and  bright 
flame.  These  globules,  which  appear  to  be  metal* 
lie,  are  the  basis  of  potash,  that  alkali  being  com- 
posed of  this  peculiar  base  and  oxygen. 

Soda,  when  acted  upon  in  the  same  manner,  ex- 
hibited an  analogous  result,  and  these  effects  equally 
took  place  in  the  atmosphere,  and  when  the  alkali 
was  acted  upon  in  the  vacuum  of  an  exhausted  re- 
ceiver :  but  these  globules  could  not  in  either  case 
be  produced  from  cpysfallized  idkvAiGs. 


ON  THB   FIXED   ALKALIES.  6t 

'  When  a  globule  of  the  base  of  potash  was  ex- 
posed to  the  atmosphere,  it  immediately  attracted 
oxygen,  and  a  white  crust  formed  upon  it,  which 
proved  to  be  pure  potash.  When  the  globules  were 
strongly  heated  and  then  suspended  in  oxygen  gas, 
%  rapid  combustion  with  a  brilliant  white  flame  was 
produced,  and  these  metallic  globules  were  con- 
verted to  an  alkali,  whose  weight  greatly  exceeded 
that  of  the  combustible  matter  consumed. 

When  Sir  Humphry  Davy  had  thus  detected  the 
bases  of  the  fixed  alkalies,  he  had  considerable  diffi- 
culty to  preserve  and  confine  them,  so  as  to  examine 
their  properties  and  submit  them  to  experiments. 
He  found,  however,  that  in  recently  distilled  naphtha 
tlieyniay  be  preserved  many  days,  and  that  their  phy* 
ncal  properties  may  be  easily  examined  in  the  atmo- 
sphere, when  they  are  covered  by  a  thin  film  of  it. 

The  basis  of  potash,  at  60^  Fahrenheit,  is  only 
imperfectly  fluid ;  at  70°  it  becomes  more  fluid ; 
and  at  150°  its  fluidity  is  perfect,  so  that  different 
globules  may  be  easily  made  to  run  into  one.  ^t 
5(r  it  becomes  a  soft  and  malleable  solid,  which 
has  the  lustre  of  polished  silver ;  and  at  about  the 
freezing  point  of  water  it  becomes  harder  and  brit- 
tle, and  when  broken  in  fragments  exhibits  a  cry- 
stalline texture  of  perfect  whiteness  and  high  metal- 
lic splendour. 

To  be  converted  into  vapour,  it  requires  a  tem- 
perature approaching  that  of  a  red -heat.  It  is  an 
excellent  conductor  of  heat,  and  a  perfect  conductor 
of  electricity. 


62  ON  THE   FIXED   ALKALIES. 

Resembling  the  metals  in  all  these  properties,  it 
is,  however,  remarkably  different  from  any  of  them 
in  specific  gravity ;  for  it  will  not  sink  in  douUe 
distilled  naphtha,  whose  specific  gravity  is  only  .770, 
that  of  water  being  considered  as  1 .000.  Sir  Hum* 
phry  Davy  has  determined  by  experiment  that  its 
specific  gravity  is  to  that  of  mercury  as  10  to  SSS* 
which  gives  a  proportion  to  that  of  water  nearly  as  6 
to  1 0 ;  so  that  it  is  the  lightest  metallic  body  known. 
When  this  substance  is  introduced  into  chlorine 
gas,  it  burns  spontaneously  with  a  bright  red  ligfat» 
and  chloride  of  potash  is  formed.  When  thrown 
upon  water,  it  decomposes  it  with  great  violence^ 
and  instantaneous  explosion  is  produced  with  bril* 
liant  flame,  and  a  solution  of  pure  potash  b  the 
result.  When  a  globule  is  placed  upon  ice,  not 
even  the  solid  form  of  the  two  substances  can  pre^ 
vent  their  union ;  for  it  instantly  bums  with  a  bright 
flame,  and  a  deep  hole  is  made  in  the  ice,  whidi  is 
found  to  contain  a  solution  of  potash.  When  a 
gfebule  is  dropped  upon  moistened  turmeric  pq>er» 
it  instantly  bums,  and  moves  rapidly  upon  the  pi^ 
per,  as  if  in  search  of  moisture,  leaving  behind  it  a 
deep  reddish  brown  trace. 

So  strong  is  the  attraction  of  the  basis  of  potash 
for  oxygen,  that  it  discovers  and  decomposes  the 
small  quantities  of  water  contained  in  alcohol  and 
ether,  even  when  they  are  carefully  purified.  When 
thrown  into  the  mineral  acids,  it  inflames  and  bums 
on  the  surface.  In  sulphuric  add,  sulphate  of  pot* 
ash  is  formed  ;  in  nitric  acid,  nitrous  gas  is  disen* 


ON  THE   FIXED   ALKALIES  63 

jptgtd^  and  nitrate  of  potash  formed.  When  brought 
in  contact  with  a  piece  of  phosphorus,  and  pressed 
upon,  there  is  a  considerable  action  ;  they  become 
fluid  together,  bum,  and  produce  phosphate  of  pot- 
ash.     When  a  globule  is  made  to  touch  a  globule 
of  mercury  about  twice  as  large,  they  combine  with 
considerable  heat :  the  compound  is  fluid  at  the 
tefpperature  of  its  formation  ;  but  when  cool  it  ap- 
pears as  a  solid  metal,  similar  in  colour  to  silver. 
If  this  compound  be  exposed  to  air,  it  rapidly  ab- 
sorbs oxygen  ;  potash  which  deliquesces  is  formed ; 
nid  in  a  few  minutes  the  mercury  is  found  pure  and 
unaltered.     When  a  globule  of  the  amalgam  is 
thrown  into  water,  it  rapidly  decomposes  it  with  a 
Umng  noise,  potash  is  formed,  hydrogen  disen- 
gaged, and  the  mercury  remains  free.     The  basis 
of.  potash  readily  reduces  metallic  oxides  when 
heated  in  contact  with  them.    It  decomposes  com- 
mon glass  by  a  gentle  heat,  and  at  a  red  heat  effects 
a  change  even  in  the  purest  glass. 

In  his  experiments  on  soda.  Sir  Humphry  Davy 
has  discovered  that  its  base,  like  that  of  potash,  is 
white,  opaque,  and  has  the  lustre  of  silver.  The 
property  of  welding,  which  belongs  to  iron  and  pla- 
tinum, at  a  white  heat  only,  is  possessed  by  tbb 
•obstance  at  common  temperatures.  It  is  very  si- 
milar in  its  more  obvious  properties  to  the  base  of 
potash ;  but  it  has  greater  specific  gravity,  being 
thai  of  water  nearly  as  nine  to  ten,  or  as  .9348  to 
to  10.000.  In  oxygen  gas  it  produces  a  white 
flame,  and  sends  forth  bright  sparks,  occasioning  a 


64.  ON   THE    FIXED   ALKALIES. 

very  beautiful  effect.  In  chlorine  gas  it  bums  ?i« 
vidly,  with  numerous  scintillations  of  a  bright  red 
colour.  In  the  quantity  of  one-fortieth,  it  renders 
mercury  a  fixed  solid,  of  the  colour  of  silver,  and 
forms  an  alloy  with  tin.  When  amalgamated  with 
mercury,  the  amalgam  will  combine  with  other  me* 
tals.  Sir  Humphry  Davy  tried  this  with  iron  and 
platinum,  and  had  reason  to  believe  that  these  la^ttf 
metals  remain  in  combination  with  the  mercury, 
even  when  deprived  of  the  new  substance  by  expo* 
sure  to  the  air. 

The  whole  of  the  sixth  chapter  of  this  very  in* 
teresting  paper  is  occupied  with  the  detail  of  several 
curious  and  ingenious  experiments  to  ascertain  the 
proportions  of  the  bases  and  oxygen  in  the  two  find 
alkalies  ;  from  whence  he  concludes  that  100  parts 
of  potash  consist  of  about  84  basis,  and  16  oxygen ; 
and  100  parts  of  soda  consist  of  about  76  or  77 
basis,  and  24  or  23  oxygen ;  or  that  potash  may  be 
considered  as  consisting  of  about  6  parts  basis,  and 
1  of  oxgen  ;  and  soda  of  7  basis,  and  2  oxygen. 

In  reply  to  the  question,  whether  the  bases  of 
potash  and  soda  should  be  called  metals,  it  might 
be  said  that  they  agree  with  metals  in  opacity,  lus- 
tre, malleability,  conducting  powers  as  to  heat  and 
electricity,  and  in  their  qualities  of  chemical  com- 
bination. Even  their  low  specific  gravity  does  not 
appear  a  sufficient  reason  for  making  them  a  new 
class  ;  for  amongst  the  metals  themselves  there  are 
remarkable  differences  in  this  respect,  platinum  be- 
ing^ nearly  four  times  as  heavy  as  tellurium ;  and 


ON  THE  FIXED  ALKALIES.  65 

teOuriam  is  Mi  tnuch  more  than  six  times  as  heavy 
as  the  basis  of  soda.  Conceiving  the  basis  of  the 
two  fixed  alkalies  to  be  metals.  Sir  Humphry  Davy 
has  named  one  Potassium,  and  the  other  Sodium, 
adopting  that  termination  which,  by  common  con- 
sent,  has  been  applied  to  other  newly  discovered 
metals* 

In  concluding  this  very  important  communica- 
don.  Sir  Humphry  Davy  remarks  that  an  immense 
variety  of  objects  of  research  is  presented  in  the 
powers  and  affinities  of  the  new  metals  produced 
from  the  alkalies.  In  themselves  they  will  un- 
ifoobtedly  prove  powerful  agents  for  analysis ;  and, 
faai^g  an  affinity  for  oxygen  stronger  than  any 
odier  known  substances,  they  may  possibly  super- 
the  application  of  electricity  to  some  of  the 
unded  bodies^. 

In  sciences  kindred  to  chemistry,  the  knowledge 
of  tlie  nature  of  the  alkalies,  and  the  analogies  aris- 
ing in  consequence,  will  open  many  new  views ; 
tl^  may  lead  to  the  solution  of  many  problems  in 
geology,  and  show  that  agents  may  have  operated 
in  the  formation  of  rocks  and  earths,  which  have 
not  hitherto  been  suspected  to  exist. 

With  respect  to  the  properties  of  potassium,  it 
may  be  said,  in  addition  to  those  already  detailed, 
that  it  is  ductile,  and  of  the  consistence  of  soft  wax ; 
and  though  originally  of  great  lustre,  it  immedi« 

^  A  more  extended  view  of  the  connexion  between  electrical 
wd  diemical  attraction  may  be  seen  in  Sir  Humphry  l)avy*« 
Elements  of  Chetnical  Philosophy,  vol.  i,  page  1 58-— 173. 

VOL.  H.  F 


I  I  ^  k*  I, 


aod 


66  OK  THE   FIX£D  ALKilLIBS. 

ately  loses  its  brilliancy  by  exposure  to  the  air.  At 
a  temperature  higher  than  that  at  which  water  oon^ 
geala,  it  is  a  bard  and  brittle  substance ;  and  at  a 
red  heat  becomes  dissipated  in  vapour.  But  it  iS| 
perhaps,  one  of  the  most  curious  properties  of  tbes^ 
metalloids,  that  if  an  alloy  be  formed,  composed  of 
one  part  of  potassium  and  three  of  sodium,  the 
compound  will  continue  fluid  at  the  low  tempera- 
ture of  32^ 

Since  the  first  edition  of  these  Essays  was  pub- 
lished, a  new  fixed  alkali  called  iiihia  has  been  dis« 
covered  in  the  petalite,  a  mineral  brought  from  th^ 
mine  of  Utoen  in  Sweden.  This  discovery  was 
made  by  M.  Arfvredson,  a  young  Swedish  che- 
mist* The  mineral  called  spodumene  also  affixdi 
the  same  substance,  and  it  has  likewise  been  fbiai4 
in  crystallized  iepidoiiie. 

When  iiihia  is  submitted  to  the  action  of  the 
voltaic  pile,  it  becomes  decomposed ;  and,  similar 
to  potash  and  soda,  a  metallic  substance  of  great 
brilliancy  and  highly  combustible  is  separated  from 
it.  Hence  it  appears  that  lithia,  like  the  other  fixed 
alkalies,  is  a  metallic  oxide,  and  from  hence  its  me^ 
tallic  base  is  called  lithium. 

During  the  first  analysis  of  the  petalite,  M.  Arf- 
vredson  supposed  its  alkali  to  be  soda ;  but  he  soon 
found  that  it  differed  from  that  alkali,  and  that  it 
may  be  distinguished  both  from  potash  and  soda 
by  its  power  of  neutralizing  a  much  larger  quan- 
tity of  any  acid. 


ON   THE   FIXED   ALKALIES.  6/ 

the  other  alkalies,  lithia  is  very  soluble  in 
water;  and  its  solution,  like  theirs,  possesses  an  acrid 
and  nauseous  taste.  According  to  Vauquelin,  li- 
thia attracts  carbonic  acid  from  the  atmosphere  with 
great  avidity,  and  in  neutralizing  the  acids  is  more 
powerful  even  than  magnesia.     It  consists  of 

Lithium 55.2 

Oxygen 44.8 

100.0 

Several  salts  have  already  been  formed  by  the  ar- 
fificial  combination  of  this  new  alkali  with  the  acids» 
the  chief  of  which  are  the  chloride,  the  iodide,  and 
die  sulphuret  of  lithium ;  and  the  sulphate,  the  ni- 
trate, the  muriate,  the  phosphate,  and  the  carbonate 
off  lithia.  Of  these,  the  sulphate  of  lithia  crystal- 
Szes  in  small  prisms  of  a  shining  white  colour.  It 
B  more  fusible  and  soluble  than  sulphate  of  potash, 
and,  unlike  that  salt,  its  taste  is  not  bitter,  but 
merely  saline.  The  muriate  and  nitrate  of  lithia 
are  both  deliquescent  salts ;  while  the  carbonate  is 
efflorescent  and  sparingly  soluble  in  water. 

Lithia,  like  the  other  fixed  alkalies,  has  the  pro- 
perty of  converting  the  vegetable  blues  to  a  green, 
and  of  turning  the  vegetable  yellows  brown.  It  is 
^try  sparingly  soluble  in  alcohol. 

In  speaking  of  the  fixed  alkalies  in  connexion 
with  the  trade  of  the  country,  I  might  have  observed 
that  there  are  other  sources  from  which  the  manu- 
facturer may  derive  an  abundant  supply  of  the  mine- 
ral alkali,  besides  those  already  mentioned.     I  refer 

f2 


I* 


68  ON  THE   FIXED   ALKALIES.  ' 

more  particularly  to  the  immense  depositories  of  sea- 
salt  which  occur  in  various  parts  of  the  world,  par- 
ticularly in  Hungary,  Poland,  Hussia,  Spiun^i  and 
America,  and  to  that  inexhaustible  source,  the  ocean 
itself,  in  wliich  prodigious  quantities  of  the  same 
saline  body  are  perpetually  held  in  soIuUon. 

The  rocks  of  salt  in  the  British  Islands  are  far 
from  inconsiderable ;  but  the  many  thousands  of 
tons  of  it  which  are  continually  washing  our  shores, 
would  furnish  a  most  plentiful  supply  for  every  pur- 
pose whatever,  whether  for  manufacture,  agricul* 
ture47,  or  any  other  branch  of  the  arts.  Its  de- 
coniposition,  so  as  to  separate  the  soda,  would  not 
be  difficult ;  and  should  this  be  effected,  it  wpuld 
preclude  the  necessity  of  sending  the  wealth  of  the 
kingdom  to  foreign  countries  for  the  purchase  of 
mineral  alkali,  would  our  Government  allow  us  to 
take,  without  duty,  that  which  Nature  offers  so  pro- 
fusely for  our  acceptance. 

I  am  desirous,  however,  of  inserting  here  a  neoes- 


^  Near  Cordova  in  Spam  there  in  a  mountain  of  roek  salt 
500  feet  high,  and  three  miles  in  circumference,  But  the  larger 
mass  of  this  salt  hitherto  discovered,  is  on  the  Missouri  river  in 
Louisiana,  and  this  is  80  miles  long,  45  miles  in  width,  and  of  a 
prodigious  height. 

*''  Sea  salt  is  perhaps  of  still  more  importance  to  the  gnurier 
than  to  the  mere  agriculturist,  which  is  shown  by  the  fatteninff 
quality  of  our  salt  marshes,  and  by  the  avidity  with  which  all 
Neat  Cattle  devour  their  food  when  sprinkled  with  salt.  See 
*'  A  Letter  to  the  Farmers  and  Graziers  of  Great  Britcdn,  on  the 
advantages  of  using  Salt  in  theifarious  branches  of  agricuUwre, 
and  in  feeding  all  kinds  of  farming  stock ;  with  a  large  Appendix 
of  Proofs  and  Illustrations!*  By  the  author  of  these  Essays. 
The  fourth  edition,  price  2s, 


ON   TH£   FIXED   ALKALIES.  69 

8ary  caution. — ^The  late  Bishop  Watson,  in  the 
first  volume  of  his  Chemical  Essays^  page  136, 
jttks  f*  Whether  the  alkaline  part  of  rock  salt  may 
not  be  obtained  by  calcining  it  in  conjunction  with 
charcoal  in  open  fires  ? ''  This  passage,  I  suspect, 
has  occasioned  many  persons  to  expend  much  mo- 
ney and  time  on  a  fruitless  attempt ;  for  I  can  as- 
sure the  reader  that  I  have  submitted  several  hun- 
dred weights  of  this  salt,  mixed  with  a  large  portion 
of  ground  charcoal,  to  an  intense  heat  in  a  reverbe- 
ralory.  furnace  4^,  where  it  was  frequently  stirred  by 
a  strong  iron  rake  for  thirty-six  hours,  and  yet  no 
deoomposition  whatever  was  effected. 

If  Government  would  allow  us  either  rock  salt, 
or  sea  water,  free  of  duty,  various  means  entirely 
diflferent  from  those  suggested  by  Dr.  Watson  might 
be  devised  for  producing  an  abundant  supply  of  the 
alkali  in  question. 

In  the  nineteenth  volume  of  the  An7iales  de  Chi" 
$me  there  is  a  very  valuable  memoir  by  those  emi- 
nent chemists,  Le  Blanc,  Dez^,  and  Pelletier,  and 
irfiich  was  published  by  order  of  the  Committee  of 
Public  Safety  during  the  period  of  republicanism 
in  France,  that  gives  various  methods  by  which 
muriate  of  soda  (common  salt)  might  be  decom- 
posed^and  the  alkali  prepared  for  sale,  so  as  to  su- 
persede the  necessity  of  buying  Spanish  barilla. 

This  memoir,  which  is  very  long  and  circumstan- 

*•  Drawings  of  the  best  kind  of  reverberatpry  furnaces  for  the 
decomposition  of  the  alkaline  sulphates  are  given  in  the  plates^ 
Nos.  xvi.  and  xvii. 


70  ON   THE   FIXED   ALKALIES* 

tial  in  its  details,  offers  so  many  interesting  const- 
derations  to  the  people  of  France,  that  an  English- 
man must  be  devoid  of  all  patriotic  feelings  who 
could  read  it  without  wishing  it  were  in  his  power 
to  offer  some  other  source  of  revenue  to  the  const* 
deration  of  his  own  Grovemment,  or  some  article 
equally  efficient  in  its  produce,  to  be  accepted  as  a 
commutation  for  the  present  impolitic  duties  on 
salt^. 

This  subject  has  often  occupied  the  attention  of 
Pkirliament,  and  the  Reports  of  its  G>mmittees  con- 
tain a  variety  of  arguments  and  facts  to  show  the 
existing  necessity  for  the  total  repeal  of  the  present 
laws  relating  to  salt.  The  difficulties  which  have 
arisen  whenever  this  business  has  been  brought  un- 
der consideration,  have  been  many,  and  some  of 
them  so  perplexing,  as  hitherto  to  have  prevented 
the  success  of  the  several  applications  to  the  L^s- 
lature  for  the  removal  of  the  present  impost.  I  do 
hope,  however,  that  the  time  is  not  far  distant  when 
the  matter  will  be  again  taken  up  by  some  compe- 
tent individual,  who  will  indefatigably  pursue  his 
object  to  its  complete  accomplishment,  and  who  mil 
no  doubt  be  well  supported  in  so  patriotic  a  scheme 
for  the  benefit  of  the  British  nation. 


^  For  an  account  of  the  progress  which  has  been  made  in 
pealing  the  duty  on  salt,  see  the  Appendix.  Also  a  book  enti- 
tled "  Thougtits  on  the  Laws  relating  to  Salt."'  By  the  Author  of 
these  Essays.  Sold  by  Baldwin,  Cradock^  and  Joy,  Paternoster 
Row,  London. 


ESSAY   X. 


ON 


EARTHENWARE 


AND 


PORCELAIN. 


ESSAY    X. 


ON 


EARTHENWARE 


AND 


PORCELAIN. 


4 

1H£  origin  of  Earthenware  and  Porcelain  may 
probably  be  ascribed  to  accident.  It  is  very  pos- 
sible that  the  peculiar  changes  which  clay  experi- 
ences on  being  burnt  in  the  fire,  may  have  afforded 
to  some  of  the  early  inhabitants  of  the  world  the 
first  hints  for  applying  this  earth  to  a  variety  of 
useful  purposes. 

When  mankind  had  no  shelter  from  the  dews  of 
the  night,  or  the  burning  sun  of  noon-day,  but 
what  could  be  derived  from  the  trees  of  the  forest, 
bow  anxious  must  they  have  been  to  improve  their 
condition,  and  how  solicitous  to  discover  some 
mode  of  fortifying  their  miserable  huts  against  the 
vicissitude  of  the  seasons  !  It  is  therefore  not  un- 
likely that  baked  clay  in  the  form  of  bricks  was 
made  use  of  for  this  important  purpose  in  an  early 


74  ON   EARTHENWARE 

stage  of  society.  This  applicaUon  of  it  is  indeed 
known  to  have  been  very  ancient.  The  celebrated 
Tower  of  Babel,  2,200  years  before  Christ,  was 
built  with  bricks  > ;  and  when  the  Israelites  so- 
journed in  Egypt  600  years  afterwards,  their  task* 
masters  employed  them  chiefly  in  this  kind  of  ma- 
nufactory *.  Bricks  of  clay  were  used  also  by  other 
nations  of  antiquity.  The  Romans  in  particular 
had  acquired  great  skill  in  the  method  of  maldngi 
and  also  in  the  manner  of  burning,  their  bridn. 
This  will  appear  by  a  comparison  of  the  bricks  that 
compose  any  of  their  edifices,  with  those  of  the  pre- 
sent day.  The  Roman  wall  at  St.  Alban*s  (the  an- 
dent  city  of  Verulam)  is  a  direct  proof  of  this  as- 
sertion 3. 

It  was  probably  not  long  after  the  employment  of 
day  in  making  bricks,  that  mankind  learnt  the  ait 
of  using  it  in  various  other  ways  ^,  and  aequu^ 
methods  of  moulding  it  into  vessels  of  capacity,  and 
utensils  for  culinary  purposes.    Accordingly  the 

'  **  And  they  said  one  to  another.  Let  us  make  bricks^  aad 
burn  them  thoroughly.**     Genem  xi.  3,  4. 


'  "And  the  Egyptians  made  the  children  of  Israel  to 

with  rigour.  And  they  made  their  lives  bitter  with  hard  bond- 
age^ in  mortar  and  in  bricks.**  Exodusi,  13,  14.  See  abb 
chap.  V.  verses  6—19. 

5  See  Mr.  J.  Webster's  Letter  to  Bishop  Littleton,  on  this 
subject,  in  the  2d  vol.  of  the  ArcfuBologia,  page  184.  See  also 
some  observations  on  the  Ruins  of  a  Roman  wall  at  Yoifc^  bf 
Martin  Lister^  Esq.,  in  the  Phil,  Transactions,  vol.  xiii.  p.  23V. 
The  bricks  in  this  wall  were  1 7  inches  long,  1 1  mches  tmnd, 
and  2^  inches  thick^  and  they  were  all  extremely  hard. 

*  From  the  accounts  of  many  respectable  travellers  into 
Egypt^  wc  learn  that  the  inhabitants  of  that  country^  when  they 


AND    FORCELAIN.  75 

most  uncient  writers  we  have,  mention  earthen  ves- 
sels ',  and  they  speak  of  them  as  if  they  had  been 
fti  use  hotn  time  immemorial.  It  appears  also 
that  cotisiderable  pains  were  taken  in  tempering 
the  day  for  these  purposes,  for  we  read  that  this 
piiooess  was  performed  by  treading  it  with  the  naked 

-  In  the  fifth  volume  of  the  Archaologia  is  an 
ieeount  of  two  vases,  of  great  antiquity,  which 
were  found  on  the  Mosquito  shore  in  South  Ame- 
rica, and  which  are  now  in  the  possession  of  Lord 
fiBllsborough.  The  account  of  them  is  transmit* 
ted  by  Governor  Pownal,  who  says,  **  It  is  a  de- 
ekled  feet  that  they  were  made  in  South  America, 
and  that  they  are  curious  exemplars  of  some  of  the 
first  ^orts  of  human  ingenuity,  and  remains  of 
what  are  become  antiquities  even  among  the  In- 
dians.** He  also  says  that  remains  of  ancient  pot* 
teriea  have  been  discovered  high  up  the  Black  Ri- 
ver, en  the  Mosquito  coast,  and  that  Father  D. 


ipUied  to  make  their  granaries  secure^  put  their  seal  on  a  hand- 
(ol  of  clay  spread  over  the  lock  of  the  door ;  and  as  it  appears 
from  the  testimony  of  the  most  ancient  book  now  extant  ^the 
book  of  Job)  that  this  was  practised  in  the  earliest  times^  it  is 
more  than  probable  that  clay  was  then  used  for  several  other 
ioyporlant  purposes.  Norden,  part  i.  page  72.  Dr.  Pocock, 
foL  i.  mige  26.    Job  xxxviii.  14. 

»  "but  the  earthen  vessel  wherein  it  is  sodden  shall  be 
broken.'*  Leoit.  vi.  28.  "  And  the  Priest  shall  take  water  in 
an  earthen  vessel.**  Numb,  v.  1 7.  "  Thou  shalt  break  them  with 
a  rod  of  iron,  thou  shalt  dash  them  in  pieces  like  a  potter's 
vessel."  Psalm  ii.  9. 

•  "  And  he  shall  come  upon  princes  as  upon  mortar,  and 
as  the  potter  treadeth  clay."     Isaiah  xli.  25. 


76  ON   EARTHENWARE 

Acuina  mentions,  that  some  of  the  Indians  on  the 
river  of  the  Amazons  had  carried  this  ancient  ma- 
nu&ctory  to  a  great  extent,  so  as  even  to  establish 
a  traffic  for.  it  with  the  neighbouring  naUoBs  7. 

From  a  variety  of  testimonies  we  learn  that  the 
Greeks  very  early  acquired  proficiency  in  the  arts 
of  pottery.  Mr.  Fordyce,  in  describing  the  tbeatce 
of  Herculaneum,  has  told  us,  that  th^  had  odb« 
trived  how  to  form  earthen  vessels  which  had  the 
property  of  increasing  the  voices  of  their  actors  ®. 

According  to  Herodotus,  however,  vessels  of 
earthenware  were  in  his  time  extremely  scarce,  and 
highly  esteemed  by  the  nations  around  them; 
"  Twice  in  every  year,**  says  he,  "  there  are  e«* 
ported  from  different  parts  of  Greece  to  Hgfftt 
and  from  Phoenicia  in  particular,  wine  seconed  in 
earthen  jars,  not  one  of  which  jars  b  afterwards,  to 
be  seen ;  for  the  principal  magistrate  of  every 
town  is  obliged  to  collect  all  that  are  imported  to 
the  place  where  he  resides,  and  send  them  to  Meo^ 
phis.  The  Memphians  fill  them  with  water,  and 
afterwards  transport  them  to  the  Syrian  deserts. 
Thus  all  the  earthen  vessels  carried  into  Egypli 
and  there  carefully  collected,  are  continually  added 
to  those  already  in  Syria  9^" 

And  yet,  from  a  passage  in  Juvenal,  who  wrote 
in  the  first  century  of  the  Christian,  sera,  and  five 


^  Archwologia,  vol.  v.  p.  318. 

*  Memoirs  concenw^  Herculaneum,  by  W.  Fordyce,  MA. 
London,  8vo,  1750,  p.  16. 

*  Deloe's  Herodotus,  book  iii.  8.  6. 


ASD  PORCELAIN.  77 

hondred  yesurs  posterior  to  Herodotus,  it  seems  that, 
Rotwithstanding  the  former  scarcity,  earthenware 
was  then  made  in  great  plenty  in  Egypt. 

"  Hac  sevit  rabie  imbelle  et  inutile  vulgus, 
VwmdtLjictiUbus  solitum  dare  vela  phfuelis, 
Et  brevibas  pictse  remis  incumbere  testae  **/' 

On  these  lines  it  may  not  be  amiss  to  transcribe 
ihe  commentary  of  Mr.  Harnier.  *^  Juvenal/*  says 
h^  *f  describes  the  boats  of  the  Egyptians  as  if  they 
were  of  earthenware,  and  not  one  of  the  variorum 
notes  explains  this^  though  it  may  be  easily  done 
from  modern  travellers.  All  that  is  meant  is,  that 
sometimes  the  Egyptians  make  use  of  rafts,  which 
were  made  to  float,  by  means  of  empty  vessels  of 
evthenware  fastened  underneath  them.** 

••  In  order  to  cross  the  Nile,"  Norden  tells  us, 
^  the  inhabitants  have  recourse  to  the  contrivance 
of  a  float  made  of  large  earthen  pitchers,  tied  close 
together,  and  covered  with  leaves  of  palm  trees. 
The  man  that  conducts  it  has  commonly  in  his 
mouth  a  cord,  with  which  he  fishes  as  he  passes 
on.  These  are  undoubtedly  the  earthenware  boats 
of  Juvenal.** 

•*The  word  piclie  is  not  to  be  understood  as 
signifying  their  being  beautified  with  a  variety  of 


»  Juven.  Sat.  xv.  ver.  126—128. 

"  who  drive  with  little  sail 

Their  earthen  boat  before  the  summer  ^e. 
Or  through  the  tranquil  water  8  easy  swell 
Work  the  short  paddles  of  their  painted  shell/ 

Hudson's  Juv.  4 to,  London  1607,  p.  288. 


tf 


78  OM   EAtTITEKWARE 

colours ;  but  means  their  being  nibbed  with  some 
substance  that  might  fill  up  the  pores  so  as  to  pre*' 
vent  the  water  penetrating  into  the  cavity  of  the 
pitchers,  which  if  it  did  in  a  considerable  degree, 
might  occasion  the  sinking  of  this  kind  of  vessel ; 
for  the  Egyptian  earthenware  is  said  to  be  very 
porous.** 

**  It  may  be  proper  to  observe  that  these  floats 
are  not  constructed  to  pass  up  and  down  the  Nile 
like  boats,  or  designed  to  carry  goods  upon  thetai^ 
though  they  may  occasionally  be  put  to  that  use ; 
it  is  only  an  easy  way  which  they  have  discovered 
of  conveying  their  earthenware  from  Upper  Egypt, 
where  it  is  made,  to  the  lower  parts  of  that  coun- 
try ;  where  on  their  arrival  the  float  is  takeii  to 
pieces,  and  the  pitchers  sold  to  the  inhabitants  ii.^ 

According  to  Vitruvius,  who  wrote  in  the  time 
of  Augustus  Caesar,  the  ancient  Romans  made 
their  water-pipes  of  potter's  clay.  These  were  ge- 
nerally two  inches  thick,  and  joined  together  with 
common  mortar  mixed  up  with  oil.  ^Vhen  they 
had  a  joint  to  make,  they  employed  also  a  piece  of 
free-stone,  which  they  pierced  through  to  reoAve 
the  two  ends  of  the  pipes  to  strengthen  and  secure 
them  in  the  manner  of  a  bandage.     Some  of  these 


"  Manner's  Ohservatians  on  diverse  Passages  of  Scripture, 
Dr.  Clarke's  edition,  vol.  I.  page  90 — 94. 

**  Switzei^s  Hydrostatics,  4to,  1729,  p.  116. 

"  In  the  Philosophical  Transactions,  vol.  xv.  page  101 7>  ia 
an  account  of  a  fine  Roman  earthen  vessel  found  near  York, 
with  the  figure  of  a  female  face  upon  it,  of  the  natural  size.  It 
was  sent  to  the  Asbmolean  Museum  in  Oxford. 


AND   PORCELAIN.  79 

pipes  were  taken  up  a  few  years  ago  in  Hyde 
ftirkw. 

The  people  of  Britain  in  ancient  Umes  were  far* 
nisked  with  earthen  vessels  by  the  Phoenicians; 
and  they  no  doubt  soon  learnt  to  make  others  in 
imitation  of  them.  Many  urns  of  eartlienware, 
supposed  to  have  been  the  workmanship  of  the  an- 
dent  Britons,  have  been  found  in  barrows  in  diffe- 
rent parts  of  this  kingdom.  It  is  also  well  known 
that  the  Romans  made  use  of  earthenware,  and 
that  they  greatly  excelled  in  the  art  of  making  it  i^; 
as  well  as  in  the  manufacture  of  bricks  and  tiles  i^. 
Vestiges  of  several  of  their  great  potteries  i^  are 
stiU  ^cemible  in  many  parts  of  this  island  i^. 

Tliere  is  reason  to  believe  that  there  was  once  a 
eoDstderable  manufactory  of  Roman  earthenware, 
on  a  small  island  which  2000  years  ago  stood  in 
the  mouth  of  the  Thames,  at  the  back  of  Margate 
Sandy  now  known  by  the  name  of  the  Queen*s 
Channel,  at  about  two  leagues  from  the  coast. 
Governor  Pownal,  who  has  written  a  memoir  on 


**  Oiraldus  Cambrensis^  in  his  Topography  of  Wales,  written 
b  Ibc  12th  century,  describes  Caerleon  in  Monmouthshire,  the 
•nciait  I§ca  Silurum  of  the  Romans,  as  containing  stately  pa- 
laces covered  with  gilt  tiles.  Itinerary  of  Archbishop  Baldwin, 
page  83G. 

^  In  the  Philosophical  Transactions,  1695,  vol.  xix.  p.  319, 
is  Ml  account  of  a  Roman  Pottery  discovered  iabout  two  miles 
firood  Leeds,  the  old  LeogeoUum.  The  village  that  succeeded 
the  old  pottery  is  now  called  Potter  Newton.  Philosophical 
trauactions,  1700,  vol.  xxii.  page  564. 

**  Henry*8  History  of  Great  Britain,  2d  edit.  8vo,  vol.  ii. 
page  140.     Borlase's  Antiq,  of  Cornwall,  page  236. 


80  ON   EARTHENWARE 

this  subject,  says  that  fishermen  have  occasionaliyi 
for  many  years,  taken  up  with  their  nets  complete 
pieces  of  earthenware  from  this  particular  spot. 
They  aire  all  of  coarse  workmanship ;  but  he  sup* 
poses  that  this  was  a  manufactory  specially  em- 
ployed in  making  earthen  vessels  to  be  used  ac- 
cording to  the  Roman  ritual  in  their  religious  ce- 
remonies. Each  vessel  has  Atillianus,  the  name 
of  the  maker,  neatly  inipressed  upon  it  ^7. 

It  is  probable  that  the  early  inhabitants  of  the 
world  arrived  nearer  to  perfection  in  the  modelling 
of  clay,  and  in  the  making  of  earthen  wares,  than 
in  the  management  of  any  other  manufactures} 
for  in  the  kingdoms  of  China  and  Japan  '8,  not 
only  common  earthenware,  but  even  porcekdn  ^^ 
of  very  excellent  quality,  was  made  long  before  the 
commencement  of  the  Christian  asra. 

''  First  China's  iions^  with  early  art  elate^ 
Form*d  the  gay  tea-pot  and  the  pictured  plate  > 
Saw  with  illumined  brow  and  dazzled  eyes 
In  the  red  stove  vitrescent  colours  rise  ^ } 


*'  Archaohgia,  vol.  v.  page  282,  &c. 

'*  This  manu^ture  is  still  of  great  importance  in  China. 
At  present  **  there  are  five  hundred  furnaces  at  work,  and  nearly 
a  million  of  men  employed,  at  King-to-Ching,  a  province  of 
Kian-si."  Chaptal's  Elements  of  Chemistry,  8vo,  1791,  vol.  ii. 
page  94. 

»»  Whitaker,  in  his  Account  of  the  Course  of  Hannibal  over 
the  Alps,  says,  that  the  name  Porcelain  comes  from  the  herir 
Purslain,  which  has  a  purple-coloured  flower,  like  to  the  an* 
cient  china,  which  was  always  of  that  colour.  Vol.  i.  8vo^  1794/ 
page  55. 

*>  ''No  colour  is  distinguishable  in  the  red-hot  kiln  of  fttt 
potter,  but  the  red  itself,  till  the  workman  introduces  a  smalt 


AND    PORC£LAIN.  81 

Specked  her  tall  beaken  with  enameird  8tan> 
Her  montter-joMes  and  gigantic  jars ; 
Smeared  her  h^ge  dragons  with  metallic  hues. 
With  golden  purples,  and  cobaltic  blues ; 
Bade  on  wide  hiUs  her  porcelain  castles  glare*'. 
And  glased  pagodas  tremble  in  the  air.*' 

It  appears  also  that  porcelain,  as  well  as  earthen* 
nare^  was  made  in  ancient  Egypt ;  for  several  small 
etrthen  figures  are  frequently  found  deposited  with 
the  Egyptian  mummies,  resembling  them  in  shape, 
and  covered  with  a  blue  glazing  similar  to  that  of 
die  Chinese  porcelain.  Du'Halde  has  said  that 
iKfiB  lazuli  abounds  in  Egypt,  and  hence  some  have 
supposed  that  this  blue  has  been  produced  by  ultra* 
marine*^.  This,  however,  could  not  have  been  the 
Cise,  as  it  is  now  well  known  that  any  colour  made 
from  lapis  lazuli  would  instantly  be  destroyed  by 
the  intense  heat  of  a  potter's  oven^. 

Anxious  to  ascertain  what  article  could  have  been 
employed  to  produce  so  beautiful  a  colour  in  such 
early  times,.  Mr.  Delaval  broke  off  a  piece  of  the 
Uoe  enamel  from  one  of  these  small  images,  and 
Bobmitted  it  to  a  variety  of  experiments  and  to  the 


of  dry  wood;  which  by  producing  a  white  flame  renders 
iBLthe  other  colours  visible  in  a  moment."    Darwin. 

*'  lliis  refers  to  the  porcelain  buildings  of  the  Chinese.  An 
•ecoiint  of  a  very  singular  one  will  be  found  in  the  Chemical 
Caitchitm,  tenth  edition^  page  103. 

<*  Norden  has,  however,  Mien  into  this  error.  See  his  Tm- 
Mli,partii  p.  76,  76. 

^  oee  Klaproth,  AnnaUideChmie,  xxi.  p.  150,  and  Guyton  on 
the  colouring  Principle  of  the  Lapis  Lazuli,  in  the  xxxivth  vol. 
<Kf  the  .Attnale$  de  Chimie,  p,  tS  -,  also^  in  Nicholson's  Journal, 
4to,  vol.  i.  p.  77,  and  vol.  iv.  p.  31 1 . 

VOL.  II.  G 


82  ON   EARTHBNWARJC 

action  of  several  chemical  tests.  In  all  these  cases, 
the  results  were  exactly  what  he  would  have  ex- 
pected had  he  operated  on  a  piece  of  modem  ena* 
md  which  had  been  coloured  with  the  blue  oxide 
of  cobalt^;  the  very  article  which  the  potters  of 
the  present  day  employ.  What  an  idea  doea  this 
give  of  the  attainments  of  the  Egyptians,  more,  than 
two  thousand  years  before  the  science  of  chemisbry 
had  made  any  progress  in  Europe ! 

That  porcelain  was  not  uncommon  in  Eurtqpe 
during  the  first  century  of  the  Christian  sera,  is  evi* 
dent  from  the  discoveries  that  were  made  in,  the 
excavations  of  those  cities  which  were  destrc^edby 
the  eruption  of  Vesuvius  in  the  first  yeatf  of  the 
reign  of  the  emperor  Titus.  For,  according  to  the 
catalogue  made  by  Bajrardi,  there  were  no  kts.thao 
193  vases  and  other  utensils  of  earthenware  and 
porcelain  taken  out  of  the  ruins  of  Herculaneuro^. 

We  are  not  however  to  suppose  that  these  poroe- 
lun  vessels  were  of  European  manufacture ;  for  we 
are  expressly  informed  that  the  first  porcelain  whidi 
tvas  seen  at  Rome  was  brought  thither  firom  Pontus 
in  Asia,  by  the  victorious  army  of  Pompey,  and 
that  this  was  only  sixty-four  years  before  ChtiMtfi. 

This  in  some  measure  apcounts  for  the  great  ex- 
cellence which  the  Persians  have  arrived  at  in  this 
elegant  art.  Sir  John  Chardin,  who  travelled 
through  Persia  about  the  middle  of  the  17th  cen- 

^  See  **  An  Experimental  tnguiry  into  the  Cau$e  of  lie 
Changes  of  Colours  in  Opake  and  Cokmrtd  Bodiesr  By'Bd- 
ward  Hussey  Delaval,  4 to,  London,  1777. 


AND   FORCELAm.  83 

tmy,  hat  taken  notice  of  their  beautiful  porcelain, 
and  quotes  a  passage  from  Propertius,  one  of  the 
writets  of  the  Augustan  age,  to  show  the  antiquity 
of  the  art  among  that  people^. 

Tlie  Etruscans,  who  were  probably  a  colony  from 
Phoenicia,  are  noted  by  the  early  writers  for  their 
csusdHence  in  the  manufacture  of  porcelain.  Dr. 
IXurmn,  who  was  intimately  acquainted  with  the 
gread  Mr;  Wedgwood,  find  knew  all  his  sources  of 
information,  supposes  that  their  principal  manufac* 
lories  were  about  Nola,  at  the  foot  of  Vesuvius^  and 
dmt  they  teamt  the  art  from  the  Chinese.  This 
degant  writer  has  thus  given  his  testimony  to  the 
sojperiority  of  their  productions : 

^  Etbubia  !  next  beneath  thy  magic  hands 
(Sdes  the  quidc  wheel,  the  plastic  clay  expands  : 
Kmed  whh  fine  touch,  thy  fingers  (as  it  tnrns) 
Mark  the  nice  bounds  of  vases,  ewers«  and  urns  -, 
Roaod  each  fiur  fonn  in  lines  immortal  trace 
Unoopied  Beauty,  and  ideal  Grace.'* 

Tke  art  of  painting  vases  in  the  manner  of  the 
BStraacans  has  been  lost  for  ages,  and  this  is  sup- 
posed,  by  the  author  of  the  Dissertations  on  Sir 
William  Hamilton*s  Museum,  to  have  happened  in 
die  time  of  Pliny.  The  honour  of  the  recovery  of 
due  long-lost  art  does  not  however  belong  to  the 
late  Mr.  Wedgwood,  as  has  been  asserted;  for 


^  See  the  Ist  vol.  of  Martyn  and  Lettice's  History  of  the  An^ 
lifiitlief  of  Herculaneum. 
•»  Pliny,  I.  xxxvii.  §  2. 
^  Sir  Jdhn  Chardin*s  Travels  in  Persia,  folio,  London,  l6BBi 

g2 


84  ON    EARTHENWARE 

though  he  was  the  first  to  imitate  the  correct  and 
beautiful  forms  of  the  Etruscan  vases  and  the  paint*- 
ings  upon  them,  his  vases  were  painted  by  a  dif- 
ferent process  from  that  which  was  employed  on  the 
urns,  &c.  of  the  ancients^. 

Mr.  Harmer  informs  us  that  the  best  Asiatic 
porcelain  is  manufactured  at  l^iraz,  the  capital  of 
that  province,  which  is  distinguished  from  the  other  ' 
provinces  of  that  country  by  the  name  of  PenuA 
properly  so  called ;  also  at  Metched,  the  capital  of 
Bactriana ;  at  Yesd,  and  at  Kirman,  in  Caramania ; 
and  in  particular  in  a  town  of  Caramania  called 
ZorendL  The  earth  of  which  these  vessek  are 
made,  is  a  pure  enamel  within,  as  well  as  withottt* 
like  that  of  the  Chinese  porcelain ;  its  grain  is  as 
fine,  and  it  is  as  transparent ;  so  that  it  frequently 
equals  and  sometimes  even  excells  that  of  the  Chi- 
nese, its  varnish  is  so  exquisite. 

The  Persian  porcelain  has  another  excellence, 
that  it  resists  fire,  so  as  not  only  to  allow  of  water 
being  boiled  in  it,  but  the  vessels  for  the  express 
purpose  of  boiling  are  made  of  it.  It  is  so  hard, 
that  it  is  employed  in  making  mortars  for  grinding 
colours,  and  for  pounding  other  things ;  and  also 
for  the  moulds  for  making  bullets.  The  materials 
of  which  this  beautiful  porcelain  is  made  are  glass 
and  the  small  pebbles  found  in  rivers,  ground  very 
fine ;  with  a  slight  mixture  of  argillaceous  earth. 


*  See  the  Catalogue  of  Cameos,  Intaglios,  &c.  8vo,  printed 
tor  CadeU,  1773. 


AND   PORCELAIN.  85 

It  is  said  that  the  potters  of  the  city  of  Yesd,  in 
Ganiuania,  already  mentioned,  sent  one  day  to  the 
potters  of  Ispahan,  as  it  were  in  defiance,  a  porce- 
hifi  vessel,  which  would  hold  six  English  quarts  of 
water,  and  yet  weighed  only  the  eighth  part  of  an 
OttDoe^.  I  mention  this  anecdote,  to  show  what 
perfection  the  inhabitants  of  Persia  have  attained 
in  this  manufacture. 

In  connexion  with  this  account  of  the  excellence 
of  the  Persian  porcelain,  it  is  related  that  in  the 
year  1066,  an  ambassador  of  the  Dutch  East  India 
Company  having  brought  many  rich  presents  for 
the  Persian  court,  and  ignorant  of  the  value  which 
tbb  people  set  upon  their  own  manufacture,  brought, 
among  other  articles,  fifty- six  pieces  of  old  China 
poroeliun ;  and  that  the  king  when  he  saw  them 
laughed  heartily  in  derision,  asking  with  an  air  of 
<xintempt  what  they  were.  The  Dutch  merchants 
frequently  mix  this  Persian  porcelain  with  that  of 
Qiina  in  what  they  send  to  Holland^,  for  the  sup- 
ply of  that  market. 

'  The  Barbarini  or  Portland  vase,  has  sometimes 
been  adduced  as  a  proof  that  the  ancients  had  ar- 
rived at  great  excellence  in  the  manufacture  of 
.porcelain.  This  beautiful  piece  of  antiquity  was  dis- 
covered in  the  tomb  of  Alexander  Severus,  who 
'died  so  early  as  the  year  235,  and  the  late  Duchess 
of  Portland  actually  paid  a  thousand  guineas  for  it* 


••  Harnier's  Observations,  vol.  i.  p.  75. 
^°  Ibid.  vol.  i.  i>.  74,  75. 


86  ON    EARTHENWARE 

But  unfortunately  for  such  a  speculation,  this  ex- 
quisite piece  of  workmanship  is  not  made  of  poroe* 
kin,  but  of  glass. 

A  thick  coat  of  white  semi-transparent  glass 
covers  the  whole  of  thb  urn,  which  is  itsdf  ntiads 
of  a  deep  blue  glass,  and  the  white  oovenng  appem 
to  have  been  cut  by  the  lapicbry  in  the  same  way 
as  the  subjects  of  antique  cameos  on^coknmd 
grounds.  Siracides  idates  that  the  andents  .had 
also  the  art  of  covering  earthen  vessels  with  a  crast 
of  glass.  Mr.  Wedgwood's  imitation  of  this  €lq;ant 
piece  of  antiquity  is  however  of  pmvdah^  and  dei^ 
serves  every  conmiendation  that  can  be  bestowed 
upon  it.  The  history  of  thb  production  may  be 
given  in  a  few  words. 

Several  of  the  nobility  and  gentry  bring  deranoiia 
of  having  a  copy  of  thb  beautiful  piece  of  antiqui^ 
they  engaged  Mr.  Wedgwood  to  endeavour  to  ind^ 
tate  it ;  and  he  actually  produced  a  vase  which  far 
el^ance  and  beauty  was  considered  to  be  folly 
equal  to  the  original.  The  subscription  was  fior 
fifty  vases  at  50/.  each ;  and  notwi^standing  the 
large  sum  to  which  thb  subscription  amounted^ 
sudi  heavy  expenses  were  incurred  in  their  febricft- 
tion  tiiat  Mr.  Byeriey,  the  partner  of  Mr.  Wedgwoo4» 
has  assured  me  that  they  lost  mon^  by  the  tindtep- 
taking.  Mr.  Webber  the  artist  recdved  five  hundred 
guineas  for  moddling  it. 

In  attempting  the  history  of  the  manufacture  of 
European  porcelain,  it  may  be  remarked,  that  al- 


AND   PORCELAIN.  8/ 

ibougfa  porcelain  had  been  brought  into  this  quar- 
ter of  the  world  before  Christ,  as  has  been  nieiition- 
ed  above,  there  is  reason  to  believe  that  the  Lntro- 
duetion  of  the  knowledge  of  making  porcelain  in 
Sttrape  was  but  of  late  years^  as  will  be  seen  in  tl\e 
sequd^l.  Porcelain  is  not  made  even  now  in  the 
Indies.;  what  is  consumed  there  is  all  imported 
eitfier  from  Persia,  Japan,  or  China,  and  the  other 
kiigdoms  between  China  and  Pegu. 

The  English  cannot,  I  presume,  lay  claim  to 
modi  exeellence  in  their  manufacture  of  earthen- 
wwe  before  the  time  of  the  late  Mr.  Wedgwood, 
irtio  began  his  indefatigable  researches  about  the 
ynr  1750 :  for,  in  the  be^nning  of  tlie  last  century, 
all  the  best  tiles  and  even  the  finer  sort  of  bricks 
mete  imported  from  Denmark,  Germany,  and  Hol- 
knd  ^»    Not  but  that  bricks  and  tiles  of  clay  had 
long  been  made  amongst  us  ;  for  there  is  an  act  of 
parliament  now  on  the  statute  books,  that  was  pass- 
ed in  the  reign  of  Edward  IV  ^,  which  directs  the 
timfi  for  digging  the  earth,  the  manner  of  making 
the  bricks,  &c.;  and  it  is  so  expressed,  that  we  have 
iwaoa  to  conclude  that  bricks  had  been  made  in 
Eoig^and  from  time  immemorial.    While  on  this 
article  I  am  desirous  of  mentioning  that  there  b  a 
paper  on  the  process  of  burning  bricks,  in  the  third 
volmne  of  Bergman's  Chemical  Essays,  and  that  it 


''  Harmer's  Observations,  vol.  i.  p.  75. 
^  Houghton*8  Collections  for  the  Improvement  of  Husbandry 
and  Trade,  vol.  ii.  p.  26. 
«  Sec  1 7th  Edward  IV,  cap.  4. 


88  ON    EARTHENWARE 

contains  many  hints  which  may  be  useful  to  those 
who  are  engaged  in  that  occupation. 

It  seems  strange  that  our  remote  ancestors  did 
not  arrive  at  greater  perfection  in  the  manufacture 
of  all  these  articles,  when  it  is  considered  that  the 
island  produces  not  only  a  great  variety  of  clays» 
but  also  all  the  other  materiab  necessary  for  the 
production  of  the  best  earthenware  and  porcelain : 
Dr.  Martin  Lister,  who  wrote  in  the  latter  pert  of 
the  seventeenth  century,  distinguishes  no  less  than 
two-and-twenty  different  sorts  of  clay  in  Brittto 
which  fell  under  his  own  observation^.  Moreover, 
the  exquisite  pieces  of  workmanship  which  were  pro- 
duced at  different  periods  by  the  English  sculpton, 
show  that  there  was  no  deficiency  of  genius  and 
skill  among  our  artists,  who  probably  concdvtd 
that  the  working  in  clay  was  beneath  their 
attention. 

Walter  de  Colecester,  sacrist  of  the  abbey  of  St 
Alban*s,  is  mentioned  by  Matthew  Paris,  his  contem- 
porary, as  an  admirable  statuary ;  and  several  of  his 
works  are  described  as  exquisitely  beautiful  ^. 

Three  English  artists  of  London,  whose  names 
are  recorded,  made  the  celebrated  alabaster  tomb  of 
John  IV,  duke  of  Brittany,  carried  it  over  to  Nants 
in  a  finished  state,  and  erected  it  in  the  cathedial 
there,  A.  D.  140836. 


•«  PhU.  Trant.  No.  164,  page  255.  Campbell's  Political  Sur 
vey  of  Great  Briiam,  4to,  1774,  vol.  ii.  pag;e  16. 
'^  M.  Paris.  Vitte  Abbatum,  p.  80^  &c. 
**  Rymer's  Fotdera,  torn.  viii.  page  5 10. 


AND   PORCELAIN.  89 

Pliny  informs  us,  that  FraxiteleSy  the  famous  sta- 
tuary of  antiquity,  used  to  say  that  *'  the  invention 
of  modelling  clay  into  figures  had  given  birth  to  the 
art  of  making  statues  of  marble  and  of  bronze  ^.** 
Bat  Dr.  Shaw  tells  us,  the  Grecian  artists  did  not 
li^n  to  use  marble  either  in  sculpture  or  building 
till  the  year  720  before  Christ.  The  Jewish  peo- 
ple might  probably  employ  it  two  or  three  hundred 
years  sooner,  which  is  about  the  time  that  ivory 
houses  and  ivory  palaces  are  mentioned  in  the 
Scriptures^. 

In  returning  from  this  digression,  I  have  to  ob- 
serve, that  the  common  stoneware,  and  that  called 
white  enamel,  have  been  made  in  various  countries 
of  Europe  ever  since  the  fifteenth  century.  The  for- 
mer of  these  is  distinguished  by  a  glaze  made  by 
means  of  muriate  of  soda ;  the  latter  is  covered  with 
a  real  glass,  rendered  opaque  by  the  white  oxide  of 
tiri^D.  Stoneware  is  the  only  article  of  pottery  that 
can  be  employed  for  chemical  purposes,  where  a 
great  heat  is  required.  Macquer  says  that  our  best 
common  stoneware  is  the  most  perfect  pottery  that 
can  be,  and  that  it  has  all  the  essential  qualities  of 
the  finest  old  Japanese  porcelain.  Mr.  Pott,  the 
author  of  Lithogeognosia^  has  written  a  treatise 
expressly  to   explain  the  requisite  perfections  of 

•"  Plin.  lib.  XXXV.  §  45. 

*  Shaw's  Travels  in  Barbary  and  the  Levant,  page  172. 
I  Kings,  chap.  xxii.  verse  39.  Amos  iii.  15. 

^  Tlie  oxides  of  many  other  metals  are  used  in  different 
branches  of  jpottery,  as  will  be  shown  in  connexion  with  the 
latter  part  of  this  subject. 


00  ON    EARTHEKWARE 

stoneware  for  the  purpose  of  chemical  vessels;  but  I 
conodve  that  what  is  made  at  Lambeth  Dear  Lon^ 
don  by  the  best  of  those  manufiEicturers,  is  suscepti- 
ble of  but  little  improvement.  For  boiling  syrups^ 
and  for  many  other  culinary  purposes,  the  Lambeth 
stoneware  is  the  best  article  that  can  possibly  be 
employed ;  as  it  is  cheap,  will  stand  a  great  bea^ 
and  is  perfectly  wholesome ;  whereas  many  of  the 
earthen  utensils  used  in  our  kitchens  are  gland 
with  lead,  and  consequently  are  extremely  danger- 
ous.  Several  years  ago.  I  adverted  to  this  suljject 
in  another  work ;  but  I  was  desirous  of  repeating 
the  admonition  now,  because  I  consider  the  health 
of  the  communis  must  be  impaired  by  the  frequent 
use  of  earthen  vessels  which  are  covered  with  the 
common  Stafibrdshire  glaze.  The  acetic  add  will 
readily  dissolve  the  oxide  of  lead ;  hence  the  boiling 
of  pickles,  and  the  making  of  other  culinary  prepa^ 
rations  in  such  vessels,  must  be  highly  improper. 

The  wlute  enamel  ware  was  brought  to  its  present 
state  of  perfection  by  Bernard  de  Prissy,  a  native 
of  the  diocese  of  Agen,  in  the  province  of  Guienne 
in  France;  a  spot  celebrated  for  being  the  birth- 
place  of  the  memorable  Joseph  Scaliger  ^. 

Fkdissy  was  in  a  low  station  of  life ;  but  he  was 


^  Scaliger  is  caUed  mmnarable,  because  he  was  not  only 
well  versed  in  all  the  sciences,  but  understood  thirteen  diffieieiit 
languages.  It  has  been  said  thai  he  was  the  most  learned  man 
that  any  ag^  ever  produced.  The  variety  of  subjects  on  which 
he  wrote  with  applause  is  truly  astonishing. 


ANP   FO&CELAIN.  91 

coiment  for  his  knowledge,  industry,  and  talents. 
Thtte  were  indeed  so  many  interesting  traits  in  his 
drnider,  that  I  trust  I  riiall  be  excused  if  I  redte 
a  few  of  the  chief  drcumstances  of  his  history; 

He  is  sud  to  have  been  a  skilful  painter  upon 
l^asa  ^S  but  he  was  more  generally  known  as  a  cher 
miift.  Originally  he  was  a  land  surveyor  and 
dititightsinaii ;  but  his  taste  for  natural  history  led 
kkiLto  abandon  this  employment,  and  induced  ium 
to  Imvel  for  instruction  over  the  whole  of  France 
and  Lower  Crermany.  An  accidental  circumstance 
Anm  into  his  hands  a  cup  of  enamelled  pottery ; 
aady  foam  that  time,  his  whole  attention  and  for- 
tmewere  taken  up  in  experiments  on  enameb^« 
Nothing  can  be  more  interesting  than  the  narra- 
tive which  he  himself  has  given  of  his  labours. 

He  exhibits  himself  as  building  and  rebuilding^ 
Uafomaces,  always  on  the  eve  of  success ;  worn  out 
by  fadMmr  and  misfortune ;  the  derision  of  the  pub- 
lie  ;  the  object  of  the  angry  remonstrances  of  his 
wife;  and  then  as  being  reduced  to  such  an  extremi- 
^  as  to  burn  his  furniture,  and  even  some  of  the 
wood-work  of  his  house,  to  keep  his  fornaces  going. 


*r^ 


^  In  the  time  of  Palissy  the  art  of  painting  upon  glan  was 
iieaily  lost.  In  this  country  it  was  classed  with  £e  artss 
noLmrM  -,  but  Mr.  Walpole  has  shown,  by  a  regular  series  of 
aitkts  and  their  performances^  that  this  secret  was  never  entirely 
lost.    Walpole*s  Anecdotes  of  Painting. 

*  The  modem  enamel  pamting  is  quite  a  different  art.  This 
tMt  invented  by  John  Petitot  of  Geneva.  An  account  of  hiii 
experiments  and  discoveries  may  be  seen  in  the  Biographical 
Dictionary,  article  Petitot^  and  dso  in  Grainger's  Biographical 
Hiit«ry,  vol.  ii.  p.  288. 


92  ON   EARTHENWARE 

His  workman  presses  him  for  money,  he  strips  him- 
self, and  gives  him  part  of  his  clothes.  But  at 
length,  by  dint  of  indefatigable  labour,  constancy, 
and  genius,  he  arrived  at  the  desired  d^ee  of  per- 
fection, which  gained  him  the  esteem  and  cbnside- 
•nttion  of  the  greatest  men  of  his  age. 

He  was  the  first  who  formed  a  collection  of  liatQ* 
ral  history  at  Paris.  He  even  gave  lectures  on  that 
science,  and  received  a  moderate  subscription  from 
each  of  his  auditors,  under  the  obligation  of  retam* 
ing  it  four-fold  if  any  thing  he  taught  should  prove 
false.  He  was  the  author  of  many  singular  books 
on  subjects  of  agriculture,  fire,  earth,  salts,'  &e. 
that  are  now  very  difficult  to  be  found,  and  it  it  to 
him  especially  that  Buffon  is  indebted  for  many 
useful  hints. 

F^lissy  was  the  first  who  ventured,  in  the  face  of 
the  priests,  to  affirm  that  fossil  shells  and  calcareous 
mountains  are  the  remains  of  real  shells ;  he  was 
also  the  first  who  taught  the  true  theory  of  springs^ 
and  was  in  all  respects  an  eminent  and  accomplished 
man. — The  very  form  of  his  works  exhibits  a  proof 
of  original  genius;  they  consist  of  dialogues  be- 
tween Theory  and  Practice,  in  which  Practice  is 
always  the  instructor,  while  Theory  is  represented 
as  a  scholar  proud  of  his  own  understandings  but 
indocile  and  ignorant. 

The  high  reputation  he  acquired,  and  the  obliga- 
tions under  which  his  countrymen  stood  indebted 
to  him,  were  however  not  sufficient  to  defend  him 
from  the  persecution  of  the  Lieague ;  for,  being  a 


AND    PORCELAIN.  93 

pfotestant,  Matthew  deLawnay^,  one  of  the  greatest 
hamticB  of  his  day,  caused  him  to  be  drafi^d  to  the 
Bastile  at  the  age  of  ninety  years,  where  he  i^igna-' 
liacd  himself  by  acts  of  firmness  and  heroism. . 

His  reply  to  Henry  III.  deserves  to  be  comme-' 
morated.  '*  My  good  man,**,  says  the  King,  ''if  you 
ctnnot  reconcile  yourself  to  the  matter  of  religion, 
I  dwU  be  compelled  to  leave  you  in  the  hands  of 
any  enemies.**  '*  Sire,**  said  Palissy,  "  I  was  per- 
fiectly  ready  to  surrender  my  life  ;  and  if  the  action 
edttU  have  been  accompanied  with  any  regret, 
etrtainly  it  must  have  vanished,  after  hearing  the 
gieat  King  of  France  say,  '  I  am  compelled.*  This, 
Siie^  is  a  situation  to  which  neither  yourself,  nor 
tfiose  who  force  you  to  act  contrary  to  your  own 
disposition,  can  ever  reduce  me,  because  I  am  pre- 
pared for  death ;  and  because  neither  Your  Majesty 
nor  your  whole  people  have  the  power  to  compel  a 
MBiple  potter  to  bend  his  knee  before  the  images 
which  he  fabricates**  **  This  venerable  man  died 
about  the  year  1590. 

Several  of  the  nations  of  Europe  at  the  dawn  of 
the  eighteenth  century,  could  not  but  regret  that  the 
knowledge  of  the  manufacture  of  porcelain  had  not 
been  introduced  among  them.     At  this  time,  how- 


^  Hiis  man  must  not  be  confounded  with  the  celebrated  De 
IjHuiay  who  wrote  "  Remarks  on  the  Roman  Jurisprudence,'! 
and  died  in  1693. 

^  Chaptai*s  Elements  of  Chemistry,  vol.  ii.  p.  90 ;  and  the 
Ikpgr&pMcal  Dictionary,  article  Palissy. 


94  ON   KARTHENVirARE 

ever,  a  fortunate  drcumttaiice  aroused  the  attenfSoii 
of  the  French  people,  and  directed  it  to  this  inqport* 
antsuliject. 

Francis  D*EntreooUes,  who  had  resided  ntanf 
years  in  China  as  a  Christian  missionary,  a  man  of 
insinuating  manners,  and  of  a  mild  and  affiibk  de» 
portnienty  had  the  address  to  procure  spedmena  of 
the  materials  used  by  the  natives  in  their  poreehap» 
and  these  he  sent  to  France  with  a  summary  doi^ 
scription  of  the  Chinese  processes.  *    - 

It  may  appear  strange  that  so  jealous  a  peo[4e-ai 
the  Chinese  are  known  to  b^  should  have  allowed 
of  European  missionaries  being  settled  among  thems 
The  ecdesiastical  historian  Mosheim  has,  howetvsiq; 
investigated  this  subject,  and  it  is  highly  amunng 
to  read  his  account  of  the  arts  which  the  JendtB 
practised  to  interweave  the  doctrines  of  Jeaus  ndth 
those  of  Confucius^  and  to  learn  how  they  ingn^ 
tiated  themselves  with  the  inhabitants  of  that 
country^. 

When  the  specimens  arrived  in  France,  the  cde* 
brated  Reaumur  undertook  a  series  of  eacperiments 
to  discover  die  method  of  imitating  the  Chinese 
]miductions ;  and  he  persevered  with  amazing  in* 
dustry  until  he  had  obtained  the  main  object  ha 
had  in  view. 

The  difficulties  which  he  had  to  encounter; 
the  mistakes  he  made  during  the  investigation ;  the 
cause  of  those  mistakes,  and  the  extent  of  his  sue* 


mmm 


^  See  an  octavo  pampUel  printed  by  Tonaon  in  1760,  eo- 
titled  "  Authentic  Memoirs  or  the  Christian  Church  in  Cldna." 


AND   PORCELAIN.  95 

aie  all  well  detuled  in  the  French  DicUonaiy 
of  Chemistry,  translated  by  Mr.  Keir,  and  wiU  be 
found  under  the  article  Porcelain.  Mr.  Reaumur 
himself  in  the  years  1727  and  1729  also  publbhed 
a  foil  account  of  hb  prepress  in  this  inquiry,  in  two 
QBcmoirB  addressed  to  the  Academy  of  Sciences^ 
and  which  were  printed  in  their  Transactions. 
•  WUle  Reaumur  was  engaged  in  these  experi- 
ments, porcelain  was  begun  to  be  manufactured  in 
Snony,  and  soon  afterwards  other  manufactories 
of  it  started  up  in  different  parts  of  Germany.  We 
had  also  an  establishment  for  making  it  at  Chelsea; 
and  since  that  period  various  companies  in  dififerent 
parts  of  England,  France,  and  Italy,  have  been 
founded  for  the  same  purpose. 

Tlie  first  person  who  made  porcelain  for  sale  in 
Sacxony  was  the  Baron  Botgar,  and  it  is  probable 
that  bis  was  the  first  manufactory  of  real  porcelain 
in  Europe.  In  order  as  much  as  possible  to  pre- 
serve this  art  as  a  secret,  the  works  were  rendered 
impenetrable  to  any  but  those  who  were  imme- 
diately employed  in  them^. 

M.  De  la  Condamine,  in  his  journey  into  Italy, 
irittted  a  manufactory  of  porcelain  established  at 
Florence  by  the  Marquis  de  Ginori,  governor  of 
Le^iom,  where  he  saw  statues  and  groups  half  as 
laige  at  nature,  and  modelled  firom  some  of  the 
finest  antiques.    He  describes  the  body  of  the  ware 

^  See  the  Travels  of  Jonas  Hanway,ia  4  volumes,  4to,Loii- 
doD,  1753. 


96  ON    £ARTH£NWAR£ 

as  being  equal  to  the  best  Chinese  manufactOM^^ 
and  that  it  would  be  extremely  beautiful  if  it  had  m 
whiter  glaang;  but  that  the  Marquis  was  determined 
to  use  only  such  materials  as  were  found  io  hia 
own  country.  How  superior  are  the  advantages 
which  the  English  nobility  possess  for  improfing 
the  manufactures  of  these  kingdoms,  if  it '  wcfe 
thought  becoming  in  them  to  attend  ta  such  ob- 
jects !  In  France,  the  Count  de  Lauraguais  engaged 
in  the  pursuit  of  improvements  in  porcelain .  §at 
several  years  with  uncommon  ardour  and  succesfe* 
French  Chefnical  Dtciionary.  \', 

The  estabiishuients  of  the  most  consequence 
among  the  moderns  are,  one  at  £>resden  ;  the  King 
of  Prussians  own  manufactory  at  BerHn ;  and  the 
extensive  works  which  belonged  to  the  late  King 
of  France  at  Sevres^,  near  Paris.  There  is  also  ft 
considerable  establishment  for  the  manufacture  of 
porcelain  at  Montpellier ;  a  descriptive  account  ^ 
which,  together  with  the  process  for  making  the 
peculiar  glaze  which  is  employed  there,  was  pub- 
lished some  years  ago  in  the  Annales  de  CAimie^ 

Frederick  the  Second,  King  of  Prussia,  had  con- 
ceived so  high  an  opinion  of  tlie  importance  of  the 
manufactory  at  Dresden,  that  when  he  conquered 
Saxony  he  took  many  of  the  best  workmen  away  by 
force,  and  transported  them  to  his  own  pottery  at 

^"^  For  an  interesting  account  of  the  establishment  aad 
management  of  the  manufactory  at  Sevres,  Kee  the  Memoir 
of  Brongniart,  the  superintendant  of  the  works.  PhUm  Mag. 
vol.  xiii.  p.  342  -,  and  vol.  xiv.  p.  17,  &c 

*•  Annales  de  Chimie,  tome  ii.  p.  73 — 85. 


AND    PORCELAIN.  97 

Berlin  <9.  This  manufactory  at  Berlin  since  the  year 
1763  has  been  carried  on  for  His  Majesty*s  own 
private  account,  with  success  and  with  good  taste. 
Fife  hundred. men  have  constant  employment  in  it, 
and  large  quantities  of  the  porcelain  are  annually 
eiported^. 

Mr.  Jonas  Hanway,  in  the  account  of  his  travels, 
has  published  a  parUcular  detail  of  an  immense 
eottection  of  porcelain  which  is  laid  up  in  the  Chi- 
nese palace  at  Dresden.  The  whole  recital  would 
be  uAsuitable  to  these  Essays ;  but  the  following 
particulars  will  show  how  the  Elector  of  Saxony 
valued  himself  on  account  of  the  perfection  to  which 
die  manufacture  of  porcelidn  had  arrived  in  his 
dominions^>. 

"  The  vaults  of  this  palace,"  says  he,  "  consist  of 
foorteen  apartments  filled  with  Chinese  and  Dresden 
porcelain.  One  would  imagine  there  was  sufficient 
to  stock  a  whole  country ;  and  yet  they  say,  with 
an  air  of  importance,  that  a  hundred  thousand 
pieces  more  are  wanted  to  complete  the  intention 
of  furnishing  this  single  palace.** 

Here  are  a  great  number  of  porcelain  figures  of 
wolves,  bears,  leopards,  &c.,  some  of  them  as  big  as 


<•  Wnoolls  Memoirs  of  the  Courts  of  Berlin,  Dresden,  *c 
2  vols.  8to,  London,  1806. 

^^  Bosching's  Tour;  and  the  Appendix  to  the  Monthly  Review, 
voL  Iv.  p.  554. 

*'  The  potters  of  Dresden  were  always  as  curious  in  the  ma- 
aagement  of  their  ovens  as  they  are  in  the  roanu^ture  of  their 
pojccloiu.  Nothing  but  white  wood  is  employed  for  heating 
the  kilM,  and  this  is  never  used  till  it  is  become  thoroughly  dry^ 

VOL.  II.  H 


98  ON    EARTHENWARE 

the  life  ;  a  prodigious  variety  of  birds,  and  a  curious 
collection  of  different  flowers.  A  clock  is  preparing 
for  the  gallery,  whose  bells  are  to  be  also  of  porce* 
lain  :  I  heard  one  of  them  proved,  and  think  they 
are  sufficient  to  form  any  music ;  but  the  hamnftcn 
must  be  of  wood.** 

Here  are  forty*eight  large  China  vases,  which  ap- 
pear to  be  of  no  use,  nor  any  way  extraordinary, 
except  for  their  great  size ;  and  yet  His  Polish  Ma^- 
jesty  purchased  then)  of  the  late  King  of  Pru^a  at 
the  price  of  a  whole  regiment  of  dragoons^.** 

In  the  course  of  the  narrative,  Mr.  Hanway  men- 
tions one  very  interesting  circumstance,  via.  that' 
samples  of  the^^/  efforts  to. make  china  in  Saxony 
were  laid  up  by  the  King  of  Poland  in  this  pakee, 
together  with  specimens  of  all  the  improvaments, 
in  their  several  gradations,  from  the  first*  till  the 
time  when  the  manufactory  arrived  at  its  utmoct 
state  of  perfection^;  an  idea  truly  philosophical, 
and  which  reflects  more  honour  on  his  memoiy 
than  the  bartering  away  the  liberties  of  his  sulgects 
for  pieces  of  foreign  porcelain. 

The  passion  for  collecting  porcelain  has  been 
common  in  most  countries.  Dr.  Campbell  remarks 


^  An  Historical  Account  of  the  BriiUh  Trade  over  the 
Sea,  with  a  Journal  of  Travels,  by  Jonas  Hanway,  4  voli.  4to, 
London,  1753. 

^  The  potters  in  Saxony  are  so  exact  in  the  n»anageiiieot  of 
their  manofiEictories,  that  they  employ  none  but  the  purest  rain- 
water for  soaking  the  clay;  ana  they  prepare  the  day  only 
twice  a  jtat,  at  the  equinoxes  3  conceiving  that  at  those  1 
the  water  is  less  contaminated  With  foreign  ingredients. 


AND   PORC£LAIM.  90 

tiii^  "  to  Ormus,  at  the  proper  season  of  the  je^r^ 
resorted  the  merchants  from  Persia,  Arabia,  and 
Turkey.  At  these  seasons/*  he  says,  "  the  city  wore 
a  n£w  face*  die  outsides  of  the  houses  were  adorned 
with  cabioets  of  porcelain,  and  with  beautiful  paint* 
mg^ ;  and  all  the  riches  of  the  East  blazed  in  the 
eyes  of  the  captivated  spectator^*" 

The  greatest  part  of  the  earthenware  that  is  now 
made  in  England  is  manufactured  in  a  particular 
district  of  about  ten  miles  extent,  well  known  by 
the  name  of  the  Staffordshire  Potteries  ^.  Here 
earthenware  has  probably  been  made  ever  since  the 
time  of  the  Romans  ^ ;  but  there  did  not  appear  to 
have  been  any  ambition  among  the  manufacturers 
to  improve  the  art,  or  to  produce  any  works  of  taste, 
till  the  late  Mr.  Wedgwood  engaged  in  the  busi- 
ness. This  most  excellent  man  brought  modellers 
from  Italy  and  from  other  parts  of  the  continent, 
whom  he  engaged  at  high  wages ;  and  he  also  con- 
stantly employed  a  competent  chemist  in  experi* 
ments  ^,  that  nothing  mightbe  wanting  which  could 
eoodoce  to  extend  the  employment  of  earthenware 
throughout  Europe,  or  that  could  in  any  way  teod 

•  PoUHcal  Survey,  vol.  i.  p.  37. 

**  Seme  account  of  this  manufactory  may  be  seen  in  Plot's 
Bittoff  cf  StaffbrdsUre ,  in  Arthur  Youngs  Six  Months  Tour 
IboMg^  iheffofth  of  England,  in  4  vols.  8vo,  London,  1770  ; 
in  A%in'8  Account  of  the  Country  round  Manchester ;  atnl  in  ike. 
Chemical  Catechism,  chap.  r.  page  1 1 0. 

*  In  sinking  pits  very  evident  remains  of  Roman  potteoes 
}smt  been  discovered,  and  at  a  considerable  depth  bekm  the 
present  smfEKie  of  the  land. 

^^  See  the  first  vol.  of  these  Essays,  page  22. 

H  2 


100  ON    EARTHENWARE 

to  give  a  permanency  to  the  staple  manufactory  of 
the  county  which  had  given  him  birth. 

The  tribute  which  an  elegant  modem  poet  has 
paid  to  the  peculiar  industry  and  genius  of  this  very 
eminent  man»  is  so  just,  and  at  the  same  time  so 
beautiful,  that,  I  do  hope,  no  reader  of  taste  will 
blame  me  for  its  insertion. 

* 

**  Gnomes  !  as  you  now  dissect  with  hammers  fine 
Tlie  granite  rock^  the  noduled  flint  calcine ; 
Grind  with  strong  arm,  the  circling  chertz  betwixt. 
Your  pure  kaolins  and  petuntses  mixt  ^ ; 
0*er  each  red  saggar*8  ^'  burning  cave  preside. 
The  keen-eyed  Fire-Nymphs  blazing  by  your  side  \ 
And  pleased  on  Wedgwood  ray  your  partial  smile, 
A  new  Etruria  decks  Britannia's  isle.-— 


«« 


To  call  the  pearly  drops  from  Pity*s  eye  j 
Or  stay  Despair's  disanimating  sigh. 
Whether,  O  Friend  of  Art !  the  gem  you  mould 
Rich  with  new  taste,  with  ancient  virtue  bold ; 
Form  the  poor  fetter'd  Slave  on  bended  knee  ^ 
From  Britain's  sons  imploring  to  be  free ; 
Or  with  fair  Hope  the  brightening  scenes  improve. 
And  cheer  the  dreary  wastes  of  Sydney-<;ove ) 


**  Kaolin  is  the  name  of  a  native  earth  found  in  China,  and 
emploved  by  the  potters  of  that  country  as  one  of  the  principal 
ingredients  in  their  porcelain.  Petuntse  is  a  siliceous  stone 
found  also  in  China,  and  is  the  other  ingredient  with  which  they 
form  the  body  of  their  porcelain*  The  former  answers  to  our 
china  clay,  the  latter  to  our  Cornish  granite.  A  more  detailed 
account  of  the  nature  of  petuntse  may  be  collected  from  the 
article  *'  Porcelain"  in  Macquer's  Chemical  Dictionary ;  from 
Watson's  Chemiciil  Euays,  vol.  ii.  page  274,  and  Murray's  By» 
item  of  Chemistry  vol.  ii.  page  253. 

^  oaggar  is  the  technical  name  of  those  coarse  earthen  vca- 
sels  in  which  plates  and  all  the  smaller  articles  of  pottery  tie 
placed  before  they  are  submitted  to  the  heat  of  the  potter's  oven. 

^  Alluding  to  two  cameos  of  Mr.  Wedgwood's  manufiic- 
tare  ;  one  of  a  Slave  in  chains,  of  which  he  gratuitously  diatribu- 


r. 


•  fi' 


AND   PORCELAIN.  101 

Or  bid  Mortality  rejoice  and  mourn 

0*er  the  fine  forms  on  Portland's  mystic  urn  ^^*' 

•*  Whether^  O  Friend  of  Art !  your  gems  derive 
Fine  forms  from  Greece^  and  fabled  gods  revive ; 
Or  bid  from  modern  life  the  portrait  breathe. 
And  bind  round  Honour*s  brow  the  laurel  wreath  -, 
Buoyant  shall  sail,  with  Fame*s  historic  page, 
Elach  fiur  medallion  o-'er  the  wrecks  of  age  -, 
Nor  Time  shall  mar,  nor  Steel,  nor  Fire,  nor  Rust, 
Touch  the  hard  polish  of  the  immortal  bust.'* 

In  justification  of  the  very  handsome  tribute 
which  the  poet  has  thus  paid  to  the  immortal  Wedg- 
wood, it  is  proper  to  observe,  that  amidst  a  collec- 
tion of  the  most  beautiful  medallions  of  British  and 
Foreign  Worthies,  the  manufactory  at  Etruria  pro- 
duces vases  and  urns  in  imitation  of  jasper  and  other 
variegated  stones ;  a  fine  black  porcelain,  of  which 
very  beautiful  vases  and  bas-reliefs  are  made,  after 
antique  patterns  ;  Etruscan  vases  ornamented  with 
encaustic  paintings,  after  the  antique  ;  and  bas-re- 
liefs of  a  white  composition,  on  coloured  grounds, 
so  as  to  have  the  effect  of  enlarged  cameos.     To 


ted  many  hundieds,  to  excite  the  humane  to  attend  to  and  to 
•Mist  in  the  abolition  of  the  slave  trade ;  and  the  other  a  cameo 
of  Hope,  attended  by  Peace  and  Art  and  Labour  -,  which  was 
nade  of  argillaceous  earth  procured  from  Botany-Bay,  to  which 
place  he  sent  many  of  them^to  show  what  their  materials  were  ca- 
pable of,  and  to  encourage  the  industry  of  the  inhabitants. 

*'  Accurate  drawings  of  the  various  designs  on  the  different 
parts  of  this  curious  vase  may  be  seen  in  Darwin*s  Botanic  Gar- 
dm,  part  i.  A  very  interesting  story  has  also  been  written  by  Miss 
Edgeworth,  founded  on  the  circumstance  of  Mr.  Wedg- 
wood's imitation  of  this  valuable  piece  of  antiquity.  It  is  enti- 
tM  "The  Prussian  Vase,**  and  will  be  found  in  the  Ist  volume 
of  the  M&ral  Talet.  I  mention  this  the  rather  because  it  contains 
a  ine  eulogium  upon  our  inestimable  trial  by  Jury. 


102  OS   SARTHBNWARE 

the  late  Mr.  Wedgwood  the  country  is  indebted  for 
all  these  discoveries  in  the  art  of  pottery. 

Notwithstanding  the  energy  with  which  Mr. 
Wedgwood  devoted  his  inventive  talents  and  che- 
mical knowledge,  to  the  improvement  of  his  fa- 
vourite manufacture,  during  the  course  of  a  long 
and  industrious  life,  I  have  no  doubt  that  che- 
mistry might  still  confer  many  benefits  on  the  pot- 
ter's art,  if  the  manufacturers  in  general  would  be- 
stow such  an  education  upon  their  children  as  wouM 
enable  them  to  pay  a  proper  attention  to  the  eulli^ 
vation  of  this  science. 

Impressed  with  this  idea^  I  have  myself  frequently 
inspected,  several  of  the  largest  manufactories  cl 
earthenware  in  this  kingdom,  as  well  as  maAy 
others  of  inferior  note,   and  have  examined  their 

• 

various  processes  with  the  utmost  care  and  atten- 
tion. A  residence  of  several  years  at  Stoke-upon- 
Trent,  in  the  midst  of  the  Stafibrdshire  potteries, 
aflbrded  me  the  best  opportunities  for  this  purpose, 
and  enabled  me  to  make  those  inquiries  at  mylei- 
sure,  and  to  acquire  that  information  which  none 
but  an  inhabitant  could  easily  have  obtained. 

It  will  not,  however,  be  necessary  for  me,  wfaUe 
giving  an  account  of  this  manufactory  as  at  present 
conducted,  to  go  much  into  detail ;  because,  if  this 
were  the  object  I  had  in  view,  it  would  be  necessary 
to  devote  a  volume  or  more  to  the  purpose ;  for  I 
am  acquainted  with  few  manufactories  in  which  the 
operations  are  more  numerous  and  diversified. 

On  this  account,  I«faallcontent  myself  with  giving 


such  an  outline  of  the  business  as  will  afford  the 
general  reader  a  correct  idea  of  the  nature  of  the 
difierent  operations ;  and  at  the  same  time  shall 
propose,  for  the  consideration  of  the  manufacturers 
themselves,  such  hints  for  the  improvement  of 
some  of  the  processes,  as  I  conceive  to  be  worth 
tlittr  attention. 

Before  I  proceed  to  a  descriptive  detail  of  the 
several  processes  in  the  manufactory  of  earthen- 
ware, it  will  be  proper  to  say  a  few  words  on  the 
nature  of  the  different  materials  which  are  usually 
employed  to  form  the  body  of  the  ware  itself. 

It  is  well  known  that  the  chief  ingredients  are 
^j  and  flint ;  the  former  of  which,  when  pure,  is 
koown  to  Chemists  by  the  name  of  alumina  and 
the  latter  by  the  name  of  silica  ;  and  that  no  kind 
of  earthenware  can  ever  be  perfect,  unless  it  be 
made  of  a  suitable  sort  of  clay  ^,  and  in  that  pro- 
portion only  which  shall  be  correspondent  to  the 
quantity  of  flint  employed.  The  experience  of  ages 
has  confirmed  this,  and  has  proved  thatgood  pottery, 
M  Vauquelin  has  remarked,  differs  from  bad,  less  in 
the  diversity  of  its  elements,  than  in  their  propor- 
tions. How  crude  have  been  the  notions  of  men 
respecting  the  chemical  nature  of  bodies!  The 
great  Buffon  *^  considered  clay  to  be  merely  silica  at- 
tenaated,  and,  as  it  were,  rotted  by  the  action  of 
water,  the  air,  and  the  sun/' 

Baum^  was  of  opinion  that  sulphuric  acid  is  a 

^  Nfacquer^f  Paper  on  Clays,  in  the  Memain  of  the  Academy 
for  lAe  ywr  1 758,  is  highly  deserving  of  perusal. 


104  ON   EARTHENWAHE 

component  part  of  all  days,  and  that  the  difierenoe 
which  is  observable  in  different  samples  of  this 
earth  is  chiefly  owing  to  variation  in  the  quantity 
of  this  acid — ^but  this  opinion  is  also  erroneous. 


'  4 


There  are  four  kinds  of  clay  in  common  use  is 
the  Staffordshire  potteries  ^,  and  they  are  knowor 
by  the  following  appellations,  viz.  Black  chy» 
Cracking  clay,  Brawn  clay»  and  Blue  clay.  The 
two  former  are  the  produce  of  the  south  of  Devon* 
shire,  the  others  arc  brought  from  the  Isle  of  Pmr- 
beck  in  the  county  of  Dorset.  With  regard  to  the 
price  of  these  clays,  that  of  the  two  first  is  14^.  per 
ton,  delivered  on  board  the  vessel,  or  44^.  when 
delivered  in  the  potteries.  The  price  of  the  tw^ 
latter  is  2  Is.  on  board,  or  from  48^.  to  52r.  pet 
ton,  when  delivered  to  the  works. 

The  biack  clay  takes  its  name  from  the  colour 
which  it  usually  bears,  and  this  is  derived  from  ft 
quantity  of  bitumen  or  coaly  matter  which  it  contains. 
This  carbonaceous  portion  is,  however,  entirely  con- 
sumed when  the  clay  passes  through  the  potter>l 
oven,  for  the  articles  made  with  it  become  when 
properly  fired  of  a  good  white  ^.     It  is,  indeed,  a 


*^  For  the  properties  of  the  best  porcelain  clay  consult 
French  Chemical  Dktumary,  article  C2<qf,  or  Chaptai  s  Ckemkr 
ry  applied  to  the  Arts,  vol.  iii.  p.  225. 

**  The  Roman  potters  must  have  learnt  that  the  native  ch^ 
difier  veiy  much  in  their  nature  and  properties,  for  they  had  dif- 
ferent names  to  distinguish  them  ;  such  as  Argilla  for  potter*s 
clay;  Terra  pmgmt,D\Bick  clay;  LewiirgUUm,  vrYdte  chsf ; 
Terra  sIgiUarii,  fine  clay ;  and  Tasconmrn,  the  clay  for  cmciblea. 


AND   FORCELAIN.  105 

emioo8  hic^  that  the  blacker  this  clay  is  when  it  is 
&Bt  dug,  the  more  white  will  the  earthenware  be 
whidi  b  made  with  it. 

The  second  kind,  called  crackings  has  acquired 
its  name  from  a  property  which  it  has  of  occasion- 
iag  the  ware  to  crack  during  the  fir»t  process  of 
bamiog,  or  while  making  it  into  biscuit,  if  by  acci- 
dent a  larger  quantity  than  usual  of  it  has  been 
employed.  But  notwithstanding  this  singular  pro- 
perty>  the  manufacturers  are  fond  of  it,  on  account 
of  its  extreme  whiteness.  It  is,  however,  always  dan- 
gerous to  use  it  unless  it  be  employed  with  judge* 
menty  because  it  has  a  peculiar  tendency  to  crack 
ereo  when  mixed  with  the  usual  proportion  of  silica* 
Efcry  kind  of  clay,  when  dried  without  any.admix- 
tufc^  will  be  liable  to  this  inconvenience ;  because, 
Upure  argillaceous  earth  be  made  sufficiently  soft 
to  be  modelled  by  the  potter's  wheel,  it  will  shrink 
one  inch  in  twelve  during  the  process  of  drying,  and 
this  will  inevitably  produce  the  effect  in  question. 

The  tliird  kind  which  I  have  mentioned,  is  what 
is  known  by  the  name  of  brown  day.  The  excel* 
leooy  of  this  sort  is,  that  it  burns  white,  without 
danger  of  its  cracking  like  the  last  species,  although 
it  ks  liable  to  another  imperfection  which  is  termed 
crazing.  Some  manufacturers,  however,  employ 
this:  clay  largely,  while  others,  on  account  of  this 
peculiar  property,  refuse  it  entirely. 

Crazing  is  a  technical  term  to  denote  the  crack- 
ing of  the  glaze.  It  is  believed  that  this  generally 
arises  from  a  defective  union  of  the  glaze  with  the 


I   I    -,  i 


t06  ON  EAanuNWAiue 

body,  owing  to  the  day,  or  the  mUtiik^  of  tbe  day 
with  tbe  otber  materials  bdog  ill  calculated  to  receive 
the  glaze  properly.  But  may  it  not  be 
rather  by  the  g^ze  itself  being  not  perfectly 
ble  ?  I  suspect,  hovever,  that  it  more  frequently  orir 
ginates  from  the  drcurostanoe  of  the  ware  heing 
drawn  out  of  the  oven  before  it  has  dme  to  cool  gm? 
dually,  and  lor  the  glass  to  become  properly  aaocal^ 
ed.  See  the  artide  AtmeaUng^  in  the  Essay  on 
Glass  in  this  volume.  If  lime  be  mixed  with  tbe 
materials  which  form  die  body  of  the  warc^  that 
will  unavoidably  occasion  the  cnudng  of  the  glase. 

The  fourth  kind,  called  blue  day^  is  considemd 
to  be  the  best,  and,  indeed,  it  always  costs  the  high« 
est  price.  This  not  only  bums  white,  but  it  forMt 
a  very  solid  kind  of  ware,  and  will  bear  a  larger  pro- 
portion of  flint  than  any  other ;  and  it  is  well  known 
to  potters,  that  the  greater  the  quantity  of  silica^ 
die  whiter  will  be  tbe  earthenware ;  though  if  mote 
of  this  species  of  earth  should  be  employed  tbaa 
the  clay  will  admit,  it  would  occasion  the  goods  to 
crack  in  the  second  burning.     Both  this  and  the 

brown  clay  are  now  much  used  for  making  ■  poree* 
lain6». 

It  requires  much  practice  to  be  enabled  to  «n* 
derstand  the  nature  of  clays  suffidently  to  erofdoy 
tliem  in  pottery  to  the  best  advantage.     Dr.  L»ris, 


'^  An  interesting  enumeradon  of  a  variety  of  other  uses  to 
which  clay  may  be  i^lied,  will  be  found  in  Fourcroy*s  SyfUm 
9f  Qhamkni,  vol  ii.  p.  207. 


A1U>  PORCSLAIK.  107 

m  his  Notes  to  ^^feumann's  Cbemi&try»  has  given 
tfie  Ttsidts  of  many  eacperiments  on  the  mixture 
of  day  with  the  diffsrent  earths  and  earthy  com« 
poands  for  the  purposes  of  making  pottery,  which 
any  ha  read  widi  advantage  by  those  who  are  de* 
afoos  of  investigating  this  subject®.  Cbaptal 
speaks  of  a  wliite  earth  from  Ayoree  in  North  Ame- 
liea,  which  the  French  potters  employ.  Would 
aot  tibis  be  of  equal  value  to  our  manufacturers  ? 

Slioay  or  pore  flint,  as  I  have  stated  above,  is 
liheiRse  an  important  article  in  the  manufactwe  of 
eardianware ;  forming,  in  general,  a  fourth,  a  fifth, 
or  a  nxth  part  of  the  whole  of  the  bulk  of  the  pre- 
pmed  laixture  or  paste,  when  taken  by  weight. 

There  is  however  one  remarkable  difference  in 
the  pioperties  of  silica  and  alumina,  which  has  a 
veiy  manifest  effect  on  porcelain.  Pure  silica  is 
tranaparent ;  but  the  thinnest  lamina  of  alumina  is 
entiidf  opake. 

Alumina  has  such  an  affinity  for  silica  that  it 
wiU  nnite  with  it  even  in  the  humid  way,  and  form 
a  Uad  of  mortar,  which  will  harden  by  time,  and 
he  afterwards  incapable  of  decomposition  by  the  ac- 
tioa  ol  the  atmosphere.  This  combination  is  the 
bans  of  many  of  the  gems  and  precious  stones. 

Much  of  the  flint  used  in  England  is  brought 
from  the  neighbourhood  of  Lame  in  the  county  of 
Antrim,  in  Ireland ;  but  as  this  comes  out  of  a  bed 


^  Lewis's  Newsann,  London,  1773,  roL  i.  p.  SO,  &c. 


108  ON   EARTHENWARE 

of  limestone,  it  is  not  so  good  for  the  potter's  use 
as  the  chalk  flint.  The!  price  of  the  latter  is  at  this 
time  about  35^.  per  ton,  delivered  in  the  Stafibrd- 
shire  potteries.  The  flint  which  is  most  approved 
is  procured  chiefly  from  Gravesend,  where  it  ia 
found  imbedded  in  the  chalk  ^.  It  is  usually  sold 
at  40^.  per  ton,  delivered  at  the  works. 

The  English  potters  procure  their  flint  on  these 
low  terms,  because  the  people  who  are  employed  in. 
Kent  and  the  neighbouring  counties  in  getting  the 
limestone  and  chalk,  are  obliged  to  raise  the  flint 
also ;  which  being  in  their  way,  the  proprietors  cf 
the  quarries  are  glad  to  ged  rid  of  it  even  at  a  fery 
inferior  price. 

It  has  been  suggested  by  a  friend  of  mine»  that 
an  inexhaustible  source,  for  supplying  the  maau* 
facturers  with  very  excellent  flint,  would  be  the  sei^ 
shore ;  and  that  a  person  conversant  with  chemistry 
might  readily  examine  a  few  samples  of  pebbles,  mod 
determine  which  were  most  suitable  for  making 
good  pottery.  On  the  coast  of  Sussex  alone,  par- 
ticularly about  Brighton,  there  is  enough  of  shingle^ 
as  it  is  called,  to  serve  the  whole  of  the  British  em» 
pire  for  ages,  and  at  no  other  cost  than  the  carriage. 
Such,  indeed,  is  the  abundance  and  inconvenieoee 
of  this  natural  production,  that  it  would  be  worth 
while  for  the  inhabitants  of  Brighton  to  give  a  small 
premium  to  encourage  its  exportation. 

For  making  the  finer  kinds  of  earthenware  a  con- 

^  Snica  is  also  a  component  part  of  various  other  stones,  and 
is  the  basis  of  rock  crystal,  quartz,  agate,  &c. 


AND   PORCELAIN.  109 

liderable  quantity  of  Cornish  clay  is  also  used, 
known  commonly  by  the  name  of  China-clay.  This 
is  the  decomposed  fel-spar  of  the  granite ;  and  it 
IS  prepared  in  Cornwall  by  the  clay- merchants 
AemselveSy  before  it  is  transmitted  to  the  Stafford- 
shire potteries. 

There  are  huge  masses  or  rather  mountains  of 
iriiite  granite  in  Cornwall,  and  in  some  parts  of  the 
eoon^  this  is  found  to  be  partially  decomposed ; 
and  it  b  where  this  is  the  case,  that  the  mineral  is 
raised  and  prepared  for  the  purpose  of  making 
earthenware  and  porcelain,  it  having  been  discover- 
edsome  years  ago,  by  Mr.  Cookworthy  of  Plymouth j 
that  this  mineral  furnishes  us  with  the  true  kaolin^ 
aod  also  with  the  petuntse  of  the  Chinese. 
.  Gfaranite  is  composed  of  quartz,  fel-spar,  and 
Buca :  and  Mr.  Gerhard  found,  in  making  an  expe* 
liment  on  granite,  that  the  fel-spar  melted  into  a 
transparent  glass ;  under  it  the  mica  lay  in  the 
ferm  of  a  black  slag,  and  the  quartz  remained  uilal- 
tensdft. 

To  render  the  decomposing  granite  of  Cornwall 
fit  for  the  manufacturer,  the  following  method  is 
adopted.  Tlie  stone  is  broken  up  by  means  of  a 
piekaxe^and  then  thrown  into  a  stream  of  running 
wileffi'  This  washes  off  the  light  argillaceous  parts 
and  keeps  them  in  suspension,  whilst  the  quartz 
and  the  mica,  thus  separated,  are  allowed  to  subside 
near  the  place  where  the  stone  is  first  raised. 


^  Nicholson's  Chmkal  Dictkmary. 


UO  ON  EAJlTHEIfWAlUE 

At  the  end  of  these  rirulets  are  m  certain  Vmd  of 
eatdh-pools,  where  the  water  is  at  last  arrested,  and 
time  is  albwed  for  the  pure  claj,  with  wfaacb  the 
watar  is  thus  charged,  to  separate  entirely  from  it. 
A4  soon  as  all  the  dajr  has  subsided,  the  iMer  » 
drawn  out  of  these  receptacles.  The  solid  matter 
is  then  dug  up  in  square  blodcs,  and  laid  on  wtiat 
are  called  iirmees,  which  are  several  connected  series 
of  strong  shelves,  ierected  so  as  to  allow  of  a  pioper 
circulation  of  air,  in  order  that  the  clajr  thiq^  be 
more  effectually  dried  for  sale.  It  is  then  piidBd 
in  casks  and  sent  to  the  Staffordshire  potteries,  and 
cbewhere,  mider  the  name  of  €hina-clv|r.  TkoM 
prepared,  it  is  extremely  white,  and  in  idie  state  of 
an  impalpable  powder.  It  may  bere  be  obaeiMd 
that  none  of  the  native  clays  are  entirely  free  from 
foreign  ingredients.  If  pure  ai^iHaoeous  earth  be 
aequired,  it  can  only  be  procin^  from  alum,  wUeh 
may  be  dissolved  in  water,  and  then  decompoaed  bff 
anlaUcBdi.  In  this  process  the  pure  clay  wU  snb* 
side,  which  should  then  be  thoroughly  washed  £ar 


The  price  of  the^  Comiah  clays  is  eondderiUjr 
higher  tiian  that  of  any  other  kind ;  but  for  many 
of  tbeteer  purposes  of  pottery,  they  are  absolqtcly 
kicBopeoeable.  They  ate  very  smooth  and  dueCik^ 
and  their  extreme  whiteness  is  very  remaikabla.  It 
was  analysed  by  Mr.  Wedgwood,  and  fidoond  to  coii*- 
sist  of  60  parts  alumina  and  20  ctf  silica. 

The  Cornish  clay  is  also  extremely  useful  for  ma- 
king crucibks,  as  it  wiU  not  fuse  by  the  addition  of 


AND   PORCELAIN.  Ill 

any  of  the  common  fluxes.  In  using  these  ccuoibles, 
howevcTi  they  should  always  be  put  witlun  others 
which  are  of  little  value ;  the  inner  ones  will  then 
acquire  the  heat  gradually,  otherwise  they  would  be 
m  gnat  danger  of  breaking. 

Besides  the  clays  already  mentioned,  some  of  the 
Ccmdah  granite  itself  is  often  used  with  the  clay  on 
aecotint  of  the  binding  quality  which  it  possesses, 
and  its  knitting  as  it  were  the  other  materials  more 
^toaely  by  its  fusibility,  it  being  naturally  more  fu- 
$aUie  than  the  earths  usually  employed  in  this  mana- 
licloty :  for  it  is  a  curious  fact^  that  neither  clay, 
sDica»  nor  lime,  will  melt  singly ;  but  by  mixing 
dieae  three  species  in  due  proportions  the  greatest 
degree  of  fusibility  is  acquired  %. 

Having  thus  briefly  described  the  several  articles 
wluch  are  most  commonly  employed  in  making  pot- 
tery,  it  will  now  be  necessary  to  explain  in  what 
manner  these  are  separately  prepared  for  use. 

Tlie  flints  are  managed  in  this  way :  they  are 
first  burnt  in  a  kiln  constructed  for  the  purpose,  and 
somewhat  similar  in  form  to  a  common  lime«kiln ; 
and  then  they  are  ground  between  very  hard  stones 
by  a  great  power,  which  is  given  either  by  the 
WAttr-wheel  or  by  a  steam-engine.  In  construct- 
ing the  apparatus  the  purity  and  hardness  of  the 
atones  are  of  very  material  consequence ;  for  should 

^  More  on  this  subject  maybe  seen,  under  the  article  Clay, 
in  hUuo^aat^B^ddUimu  to  the  Frtm:h  ChtwUcal  DirliAuify. 


112  ON   £ARTHENWARK 

theycontain  calcareous  earth,  a  portion  of  thiswouU 
be  abraded  during  the  grinding  of  the  flint,  whicli 
would  prove  very  detrimental  to  the  pottery  of  which 
it  formed  a  part. 

To  enable  the  operator  to  expedite  the  prooets, 
and  at  the  same  time  to  grind  the  flints  finer,  a 
quantity  of  water  is  thrown  into  the  niill  with  them, 
so  that  the  article,  when  finished,  has  much  the 
appearance  and  the  consistence  of  cream.  The 
health  of  the  workmen  is  also  preserved  by  this  exp 
pedient;  for,  before  this  method  was  adopted, 'the 
atmosphere  of  the  room  often  became  charged  witli 
the  finer  particles  of  the  flint,  which,  entering  into 
the  lungs,  sometimes  produced  the  most  disastrous 
consequences. 

The  grinding  the  flint  with  water  was  first  prac- 
tised by  the  celebrated  Brindley,  well  known  for  his 
skill  in  the  construction  of  inland  canals.  The 
mills  now  in  use  were  also  invented  by  him ;  and 
are  composed  of  a  very  hard  siliceous  stone  called 
chert,  which  is  found  in  abundance  in  the  ndgh* 
bourbood  of  Bakewell  in  Derbyshire. 

I  have  already  hinted,  that  it  is  important  to  at* 
tend  t6  the  nature  of  the  stone  which  is  employed 
in  these  mills,  and  some  years  ago  I  was  told  of  a 
very  severe  loss  which  was  sustained  by  many  of 
the  large  potters,  in  consequence  of  their  having 
been  supplied  with  great  quantities  of  prepared  flint 
which  had  been  ground  by  stones  containing  a  con- 
siderable portion  of  carbonate  of  lime,  which  being 
mixed  with  the  flint,  and  eventually  with  the  mate- 


AND    PORCELAIN.  1  i J 

rial  itself,  occasioned  to  the  body  of  manufacturers 
a  loss  of  many  thousand  pounds. 

In  order  to  prepare  the  clay,  it  is  first  mixed  with 
water  to  the  consistence  of  cream :  the  design  of  this 
is,  that  it  may  be  the  more  easily  passed  through  the 
sieves,  and  intimately  united  with  the  ground  Aiut, 
which  could  not  be  done  with  uniformity  and  cer- 
tainty  if  these  earths  were  mixed  dry. 

The  mixture  of  the  clay  ai!d  water  in  the  first  in- 
stance, is  generally  effected  by  means  of  long  wooden 
instruments,  which  the  men  move  bactfwards  and 
forwards  witli  considerable  force  throughout  the 
whole  mass.  It  is  an  operation  of  great  labour, 
and  is  disting-iisbed  by  the  term  bltmging. 

The  ground  6int  is  mixed  in  a  similar  way  with 
water,  and  the  stirring  is  continued  until  it  become 
one  uniform  fluid  mass.  I5ut  these  earths,  the 
clay  and  the  flint,  are  always  blunged  separate/t/; 
because,  if  otherwise,  and  the  two  earths  were  mixed 
before  being  deprived  of  their  impurities,  whicli 
cannot  be  done  till  they  are  brought  into  a  fluid 
state,  it  would  be  impossible  to  observe  the  requi- 
sitfi  proportions  of  each. 

The  Purification  of  these  earths  is  eflected  by  a 
process  similar  to  that  which  the  chemist  calls 
Elutriation.  When  the  earth  has  been  well  broken 
8od  thoroughly  mixed  with  water,  it  is  put  into  vats, 
or  other  large  vessels;  and  when  it  has  stood  long 
enough  for  the  grosser  parts  to  subside,  the  fluid 
containing  the  Bner  particles  is  drawn  off  by  a  plug, 
and  reserved  for  use. 


114  ON   £AllTtIENWAR£ 

In  every  preparation  of  these  materials  for  the 
formation  of  earthenware  or  porcelain,  it  is  of  th^ 
utmost  consequence  to  attend  to  the  relative  quan- 
tities of  each :  ther^ore,  whenever  thesis  mixtures 
of  the  fluid  clay  with  the  liint  are  to  be  made,  they 
are  always  done  with  some  nicety,  an  attention 
being  paid  to  the  specific  gravity  of  each  of  the  fluids, 
which  is  either  made  heavier,  or  diluted  further 
with  water,  as  the  case  may  require.  The  mixttift 
of  clay  and  water  after  it  has  passed  once  through 
the  sieve,  is  generally  brought  to  the  specific  gra* 
vityof  24  oz.  the  wine  pint.  A  pint  measiire  ik 
tl)e  ground  flint  and  water,  when  in  the  satne  state,  is 
usually  32  ounces. 

When  the  clay  and  the  flint  are  mixed  in  suita- 
ble proportions,  the  whole  mass,  in  this  state  of  se- 
mifluidity,  is  passed  through  the  sieves  to  take  odt 
any  remaining  impurities,  and  also  to  detain  those 
particles  which  have  not  been  sufficiently  levigated. 
The  fixture  is  then  passed  through  the  finest,  silk 
lawn,  to  ensure  the  certainty  of  no  unbroken  pieces 
remainmg  in  it,  and  to  reduce  the  whole  to  a  state  of 
the  utmost  uniformity  and  smoothness  ^. 

The  next  object  is,  to  separate  the  water  which 
has  been  employed  with  such  profusion,  and  the 
readiest  way  of  effecting  this  is  found  to  be  by  the 
direct  application  of  heat.  The  mass  is  therefore 
now  poured  into  very  long  brick  troughs,  which 


^^  A  curious  account  of  Ihe  Spanish  method  of  preparing  tbe 
clay  (br  making  the  alcarazas,  or  wine-coolers^  may  be  seen  in 
a  Memoir  by  Lasteyrie,  in  the  Journal  ties  Mine$  for  1798. 


ANU    ruHCEL^IK. 


1]5 


are  built  with  flue^  under  them  of  a  sul^cient  size 
to  afibrd  heat  enough  to  produce  an  ebullition  in 
the  mixture;  and  this  is  continued  until  so  ipuch 
of  die  water  is  evaporated  as  will  reduce  the  mass 
to  the  desired  consistence. 

The  evaporation  is,  indeed,  never  carried  beyond 
a  certain  point ;  because,  if  thiji  mixture  of  thti 
earths  were  allowed  to  become  nearly  dry,  it  would 
not  be  kneadable  by  the  usual  methods  ;  neither 
could  it  be  worked,  by  the  liand  or  the  whe^l,  into 
any  of  ttiose  forms  ivliich  it  may  be  the  intention  or 
the  interest  of  tlie  potter  to  impart  to  it. 

I  ought  to  have  mentioned,  that  the  mixture  of 
the  clay  and  the  flmt  with  water,  is  known  in  the 
trade  by  the  qaipe  of  slip  ;  tliat  the  place  in  whicU 
it  is  kept  is  the  slip-house ;  and  the  trough  OP 
whicli  it  is  boiled  is  called  the  slip-kiln. 

Wten  the  mixture  lias  been  tlius  brought  to  a 
proper  consistence,  it  ought  to  be  kept  for  a  consi- 
derable tiine,  that  the  materials  may  become  more 
intimately  upiled  than  tliey  can  ever  be  by  me|;e 
mechanical  force :  hut,  in  general,  this  is  not 
much  attended  to,  although  every  manufacturer  is 
fully  aware  of  its  importance.  Want  of  room,  <^ 
time,  and  often  of  capital,  occasions  it  to  be  some- 
tiincs  used  warm  from  the  slip-kiln,  and  not  un- 
comntonly  when  it  has  been  lying  for  only  a  few 
hours  or  days.  In  China  it  is  no  unusual  thing  for 
the  prepared  clay  to  remain  from  14  to  20  years 
before  it  is  thought  to  be  in  a  lit  state  for  use  ;  and 
I  bnve  heard  of  some  districts  where  it  is  custo- 


116  OK   EARTHENWARE 

mary  for  a  father  to  prepare  as  much  porcelain-clay 
as  will  be  sufficient  for  the  use  of  his  son  through- 
out the  whole  period  of  his  life. 

When  the  dried  mass  has  been  removed  from 
the  kiln,  the  next  process  is  that  of  tempering  it, 
which  is  effected  by  first  beating  it  with  mallMs, 
and  then  turning  it  and  beating  it  again,  and  again, 
with  small  spades,  or  paddles,  as  the  workmen  call 
them,  until  it  is  thought  to  be  as  well  tempered  as 
it  can  be  by  these  operations. 

It  should  be  recollected  that  this  is  not  pure  di^, . 
but  a  mixture  of  all  the  ingredients.  Vauqu^n 
says  that  **  Silex  constantly  forms  at  least  two-thirds 
of  most  pottery ;  alumine  from  a  fifth  to  one-third ; 
lime  from  one  five-hundredth  to  one  twenty-hun- 
dredth part ;  and  iron  from  the  minutest  quantity  to 
twelve  or  fifteen  per  cent.** 

The  mass,  after  the  operation  of  beating,  under- 
goes a  process  called  slaving.  For  this  purpose 
it  is  removed,  in  the  state  of  large  lumps,  to  a  con* 
venient  bench  or  table,  where  a  man  having  cut  it 
across  with  a  brass  wire,  unites  it  again  by  slapping 
one  of  the  halves  down  upon  the  other  with  all  hb 
force ;  he  then  cross-cuts  it  again  and  agun,  and 
as  often  unites  it  by  main  force,  as  before. 

This  cutting  the  clay  in  pieces  and  slapping  it 
together,  is  a  laborious  operation  ;  but  it  must  al- 
ways be  continued  until  the  air-bubbles,  which  the 
mass  at  first  contained  in  great  abundance,  are  all 

driven  out  of  it ;  because,  if  the  air  was  not  thus 
carefully  expelled  from  the  clay,  it  would  escape 


AND   FORCfiLAIN.  117 

when  it  became  rarified  in  the  oven^  and  this  would 
prodace  such  blisters  as  would  spoil  the  manufac- 
tured goods.  On  this  account  the  slapping  is  con- 
^tinued  unUl  the  mass  exhibits,  wherever  it  may  be 
.ent^  a  perfectly  smooth  and  homogeneous  surface. 

Of  late  years  Mr.  Wedgwood  and  some  other 
eomiderable  potters  have^  however,  employed  an 
apparatus  invented  by  Mr.  Thomas  Lowe  of  Not- 
.tingham,  which  effects  all  these  purposes  at  once.  It 
is  moved  by  a  steam-engine,  and  performs  all  these 
(operations  with  a  surprising  economy  of  time  and 
kboor.  It  first  breaks  the  burnt  flint ;  it  then  grinds 
it  in  water,  and  another  part  of  the  apparatus  per- 
forms the  hitherto  laborious  operation  of  blunging^ 
the  day  in  water  and  breaking  it  into  a  semi- 
floid  and  uniform  mass.  When  this  is  done,  it  is 
nm  off  and  sifted  by  several  sieves  of  different  de- 
grees of  fineness,  all  which  are  moved  by  the  same 
power«  Tliis  earthy  fluid  then  runs  down  to  a  lower 
loom,  where  it  goes  through  other  sieves  in  the  same 
way.  In  like  manner,  another  part  of  the  apparatus 
squeezes  the  dried  clay,  to  save  the  expensive  ope- 
talion  of  slapping^  described  at  page  116;  after 
which  it  passes  to  an  iron  cylinder  full  of  knives, 
where  it  is  cut  into  pieces  with  great  expedition  ; 
which  saves  the  expense  of  cutting  it  by  hand  with 
brass  wires,  as  before  mentioned.  This  receptacle 
if  not  properly  a  cylinder,  but  a  large  hollow  inverted 
cone  of  iron,  and  the  knives  are  fixed  in  an  upright 

••  This  is  the  technical  term,  biit  doubtless  it  is  a  corruption 
6f  the  word  plunging. 


118  OK   BAlttH£NWAR£ 

shaft  which  revolves  tHthtil  it  flfid  passes  thhnigh 
its  centre;  Thede  knives  are  so  contrived  that  the 
clay,  as  it  is  ciit,  ib  forced  lower  and  lower  by  HWj 
revolutibn,  until  at  llisb  it  is  pressied  by  the  ptttMr 
of  the  machinery  thtdugh  a  square  hol^  neiir  iShIt 
bottom  of  the  ap))aratus,  from  whence  it  is  r^nldved 
as  it  MU,  and  is  carried  in  blocks  to  the  otht^r  partis 
of  the  manufactory. 

The  clay  having  undergone  thesis  varied  opM- 
tion^,  it  is  now  (it  for  being  formed  into  any  fthip^ 
or  employed  for  any  purpose,  for  whith  it  isdesiglittfl. 
Accordingly,  it  is  fashioned  into  various  forWis  V^ 
means  of  a  variety  of  moulds  made  of  plb^ttf  bf 
Paris ;  or  put  into  ad  great  a  diversity  ot  ^fmpik  Vf 
the  |)olter's  wheel. 

Nothing  ts  JFobnd  to  answer  so  well  for  knAkki|; 
the  potter^s  moulds  ais  plaster  of  Paris ;  betiMiii, 
when  righi  prepared;  it  h^  the  property  of  Ab* 
sorbing  the  water  SO  very  rapidly  from  the  Waft, 
that  it  Occasions  it  to  slip  out  of  the  mould,  or  tb 
dlf/tV^  itself  eA^ity,  as  the  technical  phrase  is. 

To  prepaid  the  piaster  for  making  the  moulieh^  it 
is  first  grotind  ih  a  mill  exactly  siniilar  tb  tJtet 
which  is  geherijilly  used  for  grinding  corn  By  MettAfs 
of  a  pair  of  flour  stoheb  ;  it  is  theA  b^ked,  or  t%tber 
boiled  ^,  to  expell  the  Water  which  i§  one  ^f  ltd  cbtft- 
ponent  parts  when  in  a  nsitive  state. 


^*  Boiled,  ThU  may  appear  to  be  an  incongruous  expression 
when  applied  to  a  dry  earthy  substance ;  but  the  fact  is,  that 
when  the  ground  plaster  is  heated  it  has  so  much  the  appear- 


AND   PO&C£LAiNV  i  19 

Hm  plaster,  whicli  is  the  native  sulphate  of  lime, 
is  boiled  in  very  long  brick  troughs^  having  a  fire 
flue  running  underneath  them.  The  man  who 
saperintends  the  process  has  a  handkerchief  tied 
over  his  mouth  for  safety;  as  the  small  particles 
getting  upon  the  lungs,  or  into  the  stomach,  have 
been  found  to  be  very  injurious  to  the  health  of  the 
operator. 

When  this  plaster  has  been  thus  deprived  of 
water,  it  is  in  the  state  of  a  soft  and  impalpable 
powder  ;  and  if  its  own  proportion  of  water  be  again 
mixed  with  it»  it  will  immediately  set  into  a  hard 
eompact  mass.  It  is  this  property  which  renders  it 
ao  peculiarly  fit  for  making  the  potter  s  moulds. 

The  manipulations  by  which  the  different  artl- 
des  of  earthenware  are  made,  are  so  various  and 
multiplied,  that  it  would  be  very  difficult,  if  not 
impossible,  to  describe  them.  They  can  be  known 
Only  by  those  who  have  had  oppoilunities  of  visit- 
ing a  pottery.  A  short  outline  of  these  processes 
mil  however  be  expected  from  me,  and  may  be  ac- 
eeptable  to  the  generality  of  my  readers. 

Much  of  the  common  earthenware  is  formed  by 
means  of  the  potter's  wheel,  which  is  a  round  board 
'tttlached  to  a  lathe,  and  capaUe  of  being  moved 
ilraieby,  either  rapidly  or  otherwise,  as  the  occasion 
may  require^  This  round  board  moves  in  a  horizon- 


^•■ 


ance  of  ebullition,  that  the  term  which  I  have  employed  is  made 
of  by  the  workmen  universally.    The  finished  article  is  al- 
eallcd  hoUed  plaster. 


120  ON   EARTHENWARE 

tal  position ;  and  when  in  use,  the  clay  which  b  to 
be  fashioned  is  fixed  on  the  centre  of  it ;  and  it  is 
put  in  motion  dther  by  a  person  who  constantly 
attends  it  when  at  work,  or  by  means  of  a  treadle 
which  is  moved  by  the  foot  of  the  workman  him- 
self. 

As  the  clay  revolves  upon  this  machine,  the  work^ 
man  either  models  it  by  his  fingers,  or  forms  it,  by 
means  of  an  instrument  which  he  holds  in  his  hand, 
into  any  kind  of  circular  shape  that  he  may  desire ; 
and  when  the  object  is  to  make  a  number  of  vesaelt 
exactly  similar  to  each  other,  the  size  is  generaHy 
determined  by  a  gauge  fixed  without  the  circumfet- 
rence  of  the  revolving  wheel,  but  projecting  ovtr  it 
in  such  a  manner  that,  whenever  the  yielding  day 
is  spread  out  until  it  touch  this  gauge,  the  artisk 
knows  that  the  article  which  he  is  making  hat  at- 
tained the  exact  figure  which  he  intends. 

The  potter*s  wheel  is  probably  the  most  ancient 
of  the  manufacturing  instruments  now  in  use.  It 
was  known  to  the  author  of  that  book  in  the  Jewish 
Scriptures,  which  claims  the  highest  antiquity  of 
any  writings  we  have,  and  who  must  have  lived  at 
least  3000  years  ago.  This  simple  instrument 
has  however  of  late  years  been  much  improved  by 
adapting  a  strap  to  it,  which  passes  over  a  large 
taper  cylinder  of  wood,  by  means  of  which  the  artitft 
is  enabled  to  increase  or  diminish  the  rapidity  of  the 
motion  at  pleasure.  This  contrivance  is  known  to 
mechanics  by  the  name  of  the  cone  pulley. 

In  going  through  a  pottery^  it  will  be  observed. 


AMD   PORC£LAIN.  12] 

that  all  the  articles  are  very  thick  and  coarse  when 
they  come  from  the  wheel.  This  is  perhaps  un* 
avicddable.  They  are  therefore  taken  to  a  lathe, 
where  the  extra  quantity  of  clay  is  removed,  in  the 
same  manner  as  the  wood-turner  forms  his  work 
by  shaving  off  successive  portions  of  the  wood, 
lliese  parings  of  clay  are  afterwards  kneaded  as 
before^  and  then  worked  over  again  for  similar  pur* 
poses. 

It  la  curious  to  notice  the  great  variety  of  circular 
tbinga  that  may  thus  be  made  by  means  of  the  pot- 
ter*8  wheel ;  but  it  must  be  remembered  that  this 
machine  is  calculated  only  for  cylindrical,  conical, 
<Nr  round  articles,  and  not  for  such  as  are  of  an 
ovi^  or  an  irregular  form.  All  such  are  made  in 
plaater  moulds,  which  divide  in  halves  for  the  con^ 
venience  of  taking  out  the  ware  whenever  it  is  found 
to  be  sufficiently  dry  to  be  removed.  The  handles 
of  cups  and  jugs  are  also  made  in  moulds,  and  these 
are  sAerwards  put  on  the  vessels  for  which  they 
were  designed. 

The  consumption  of  sulphate  of  lime,  gypsum,  of- 
alabaster,  (for  this  substance  is  known  by  these  vari- 
ous names,)  is  so  considerable  for  making  the 
moulds  for  plates  and  dishes,  that  in  the  course  of 
the  year  many  tons  of  worn  out  moulds  are  thrown 
away  as  useless,  I  would  suggest,  that  these  might 
be  ground  and  used  as  manure,  instead  of  purchas- 
ing  fresh  gypsum  for  that  purpose^ 

As  the  plaster  moulds  absorb  water  with  avidity, 
the  articles  which  are  made  in  them  dry  much 


122  CM   EARTHEKWAILE 

sooner  than'  would  generally  be  imagiiu^  For 
instance,  the  moulds  on  which  the  common  table* 
plates  are  formed,  are  put  into  a  very  temptsrate 
ttove  as  the  plates  are  made,  and  in  about  two  hours 
Ihe  whole  will  be  dry  enough  to  be  removed  to  aiake 
room  for  a  fresh  parcel.  In  the  usual  way  of  con^ 
ducting  a  manufactory,  evety  mould  b  capable  of 
taking  four  or  five  fresh  plates  in  the  course  of  a  dxf 
of  twelve  hours.  The  plate-stove  is  generally  m 
very  small  room  built  with  bricks,  and  shelved  with 
boards  from  the  floor  to  the  ceiling.  It  is  usually 
heated  by  an  iron  pipe  which  passes  through  it^ 

When  the  plates  are  removed  from  this  ston^ 
they  are  taken  off  the  moulds,  and  pared  round  die 
^ges  with  a  small  knife ;  and  when  they  have  been 
slightly  polished  by  the  hand,  they  are  laid  by  to 
become  hard  enough  for  the  biscuit  oven. 

fVom  this  short  account  it  may  be  easily  con- 
ceived that  a  common-sized  pottery  must  require  a 
great  deal  of  rocHn,  especially  as  every  article,  wfao- 
ther  made  by  the  wheel,  the  lathe,  or  the  moulds, 
aiAUSt  be  spread  out  upon  shelves  to  dry:  and  this 
-reminds  me  of  an  expedient  which  I  lately  obaervisd 
at  the  works  of  an  ingenious  potter  in  StaffiNrdshii^ 
land  which  I  conceive  to  Iw  so  £ar  an  improvemeot 
upon  the  old  practice,  as  to  deserve  being  mentioned, 
'and  which  I  have  the  leave  of  the  proprietor  to  make 
public 

The  improvement  to  which  I  refer,  h  that  of 
having  a  >cfaaniber  shelved  entirely  round,  not  with 
Mones  t>r  boards  ns  is  osual,  but  with  shelves,  of 


ANH   PORCELAIN.  IStS 

prepares  plasteir  made  as  smooth  aB  poliBhed  marbto, 
a^d  of  the  thickness  of  an  inch  and  a  half  eadh. 

Updo  these  plaster  shelves,  instead  of  those  of 
wood  and  stdne  as  commonly  adopted  at  othisr 
works,  the  goods  are  placed  to  dry :  and  the  great 
advantage  which  must  accrue  to  the  manuftitsturei: 
from  the  practice  is  very  obvious ;  for  the  plasteir 
ndl  only  absorbs  the  water  sooner,  but  the  arlitles 
will  dry  ttiore  regularly  and  unifontily  thah  they  pols^ 
^ly  can  when  plated  upon  substances  which  ca^«- 
aot  abstract  the  water.  Being  persuaded  olP  th^ 
atility  of  this  expedient^  I  have  no  hesilatibh  iki  r6- 
eemmendiitg  it  for  general  imitation.  MoreOter> 
why  iiiay  not  the  floors  Of  a  pottef's  wa^ehou^^  be 
oovetM  with  plaster  ?  The  e^pen^e  Would  be  very 
ioeonsid&rabte,  and  then,  whenever  th^e  wer^  tM 
in  use  for  storing  the  finished  ware,  they  might  be 
ad^ntageously  employed  in  hastenihg  the  drying 
of  iSase  goods  newly  made. 

In  soitietrounties  it  is  usual  to  form  the  fl06i%  of 
cheese  chambers  with  plaster,  and  I  have  been  toM 
'that  the  cheese  becomes  sooner  ripe  oti  thiese  iftoors 
dnrn  on  others ;  though  Mr.  Twamley  di^eO^  thaft 
-k  should  not  be  placed  on  plaster  ^i^til  tiiM  ha^ 
been  •allowed  for  the  first  moisture  to  ^xade  atid 
waporatfe  70. 

An  important  iibprovement  might  be  made  in 
the  manufacture  of  eaMhenware,  if  it  were  poissiiblk 


^  JaMh  TVamiey  On  }t>airying,  8vo,  Warwick,  1^84,  p,  VOO.* 


1 24  OM    £ A&THEN WARE 

to  contrive  an  expeditious  mode  of  ispreadiog  tbe 
goods  out  80  as  they  might  always  dry  gradually. 
The  property  which  clay  has  of  contracting  by  heat 
or  by  drying  is  well  known,  and  tbe  exoellenoe 
of  earthenware  depends  in  a  great  measure  on  its 
bebg  stiy  gradually  dried  before  it  be  exposed  to 
the  kiln. 

When  the  articles  of  pottery  have  been  m  oddled 
or  fashioned  to  the  design  of  the  artist  by  any  of 
the  foregoing  methods,  and  have  been  partially 
dried,  either  by  an  exposure  to  the  action  of  the  at* 
mosphere,  or  by  placing  them  for  a  certain  time  in 
stoves  or  drying  rooms  constructed  for  the  purpoaei 
they  are  carried  to  the  potter's  oven,  where  they  are 
placed  in  deep  oval  boxes  made  of  fire  clay.  These 
jare  called  seggars ;  anp  being  flat  "at  bottom,  one 
of  these  vessels  forms  a  cover  for  another,  so  that 
the  workmen  are  enabled  without  difficulty  to  place 
them  in  piles  nearly  to  the  top  of  the  oven,  wUcfa 
is  a  large  building  of  brick,  in  the  form  of  a  conCf 
and  very  similar  to  a  common  glass-house* 

When  the  oven  is  properly  filled,  heat  is  applied 
by  means  of  ignited  coal,  which  b  thrown  into 
several  receptacles  built  on  the  outside,  but  com- 
municating,  by  means  of  flues,  with  the  inner  part. 
These  are  called  mouths ;  they  stand  about  four 
feet  in  hdght  from  the  ground,  and  project  about 
three  feet  from  the  sides  of  the  kiln* 

In  the  beginning  the  heat  is  kept  at  a  low  state ; 
but  after  a  lapse  of  twelve  hours  it  is  gradually  in- 
creased, and  the  augmentation  of  temperature  is 


AND   PORCELAIN.  125 

continued  until  the  kiln  and  its  contents  acquire 
the  proper  maximum. 

An  attention  to  the  degree  of  baking  is  an  object 
of  extreme  importance.  Vauquelin  has  remarked 
tfiat  ^^the  heat  should  be  such  as  to  expel  the  mois- 
ture, and  agglutinate  the  parts  which  enter  into  the 
composition  of  the  paste ;  but  incapable  of  effecting 
the  fusion,  which,  if  too  far  advanced,  will  render 
the  ware  of  so  homogeneous  a  texture  as  to  become 
bfittle7i." 

It  has  been  found  that  alumina  loses  0.46  of  its 
weight  even  when  the  fire  is  not  urged  beyond  the 
temperature  of  ignition  for  silver;  wlience  it  ap« 
peart  that  it  contidns  nearly  half  its  weight  of  water, 
and  it  does  not  part  with  the  last  portion  but  with 
great  difficulty. 

The  operation  of  burning  usually  lasts  two  days 
and  two  nights.  This,  however,  varies  in  the  dif- 
ferent charges ;  and  the  fireman  judges  when  the 
ware  is  sufficiently  burnt,  by  examining  the  trial 
jrfeees  which  are  placed  in  those  parts  of  the  oven 
where  they  may  be  taken  out  with  ease,  and  with- 
out causing  any  diminution  of  the  heat. 

These  trial  pieces  are  made  of  the  common  red 
day,  of  the  Staffordshire  brick-makers.    It  is  found  . 
in  the  Potteries,  and  has  the  property  of  changing 
its  colour  at  every  change  .of  temperature :  there- 
fore, by  comparing  one  of  these,  taken  out  of  each 

**  Vauouelin*8  Re/Uctions  on  the  QualUies  of  Pottery ,  com* 
aaaicated  to  the  Philomathic  Society  at  Paris. 


126  ON   SAftTH£NWAt£ 

part  of  the  oven,  with  a  trial  piece  madfi  of  the  aamo 
kind  of  clay  and  properly  burnt,  and  ivbid)  1$  kept  w 
purpose  for  a  standard,  theisxact  state  of  Ae  wana  w> 
der  operation  may  at  any  time  be  exaotly  kDOWtt. 

All  the  eommon  ware  undergoes  two  brings ;  that 
is,  when  it  has  been  sufficiently  dried  in  the  aiTf  it 
is  put  into  an  oven  and  made  into  wha(  is  called 
Oseuii,  which  is  earthenware  partially  burnt^ 

Many  ladies  are  in  the  habit  of  buying  jahiafl.W 
the  state  of  biscuit,  for  the  purposes  of  painting  and 
gilding.  When  they  have  imparted  their  ^TO  ^ 
signs,  these  are  sometimes  returned  to  the  poMfTf 
who  burnishes  die  ffM  and  completes  the  balmg* 
This  is  mentioned  with  the  view  of  dinecting  thwa 
females  who  may  not  be  already  acquainted  iriUl 
tt,  to  a  new  object  Cor  ti^  exercise  of  their  taste  and 
genius,  and  also  for  the  better  .expJaoaUon  af  Ilia 
nature  of  biscint  ware. 

All  the  jBnglish  carth^ware  and  cbioa  ^nAw? 
goes  tills  previous  firing,  because,  were  it  not  %f9^ 
made  into  biscuii,  it  would  not  bear  to  be  immivafd 
in  the  mixture  of  lead  and  water,  called  the  gfaffp^ 
without  suffering  injury  thereby :  that  is,  it  woald 
not  iiail  to  be  rendered  soft,  and  liable  to  be  pff 
out  of  form,  by  its  absorption  of  the  water.  I^^f 
ther  would  it  sustain  the  process  of  printing,  nor  |d^ 
low  of  its  being  painted  upon  with  any  good  effect* 

The  composition  of  the  Chinese  porcelain  is  di£Ee« 
rent,  and  its  nature  is  now  pretty  accurately  known. 
Mr.  John  Bradley  Blake,  who  was  settled  as  a  resi- 


AND  FOaCSLAIN.  127 

dent  Supercargo  at  Canton,  and  died  there  at  the 
age  of  29^  sent,  a  short  time  before  his  death,  to 
Mr.  Saniuel  Moore,  the  then  Secretary  to  the  Society 
for  the  Promotion  of  the  Arts,  specimens  of  the 
eaitba,  clajs,*8and,  stones,  and  other  materials  used 
Iq  Biaking  the  true  Nankin  porcelain,  all  which 
Mir.  Moore  put  into  the  hands  of  the  late  Mr,  Wedg-' 
wood*  who  from  these  materials  produced  ^ome 
{rfecea  of  excellent  porcelain,  and  declared  that  those 
cinrtha  vere  so  complete  a  set  of  specimens,  that  be 
had  no  doubt  of  their  being  the  true  materials  of  the 
Oriental  porcefadn.  Had  Mr.  Blake  lived,  further 
infonnation  mmld  have  been  procured. 

It  was  ascertained  by  Mr.  Blake,  and  we  have 
leahit  from  other  sources,  liiat  in  Chiaa  the  earth<- 
enware  and  porcelain  are  merely  dried  in  the  air 
More  glazing  ;  as  their  composition  so  eSectually 
reaists  irater,  that  it  can  be  immersed  in  an  aque- 
ras  glaze,  without  being  first  made  into  biscuit,  and 
eonteqnently  that  the  Chinese  are  enabled  to  huro 
tlieir  ware  by  one  single  firing. 

It  b  therefore  a  desideratum  with  the  potters  of 
this  country,  to  find  some  substance  to  mix  with 
the  clay  which  shall  give  it  the  property  of  resisting 
the  action  of  water  before  it  has  undergone  the  first 
burning.  This  would  be  a  great  acquisition  to 
our  English  manufacturers,  because  it  would  not 
only  be  a  saving  of  fueU  but  a  great  economy  of 
dme  and  of  the  expense  of  wages,  as  one  operation 
would  be  thereby  entirely  saved. 

Dr.  Woodward  mentions  the  Soap  Rock  at  the 


128  OK  EARTHENWARE 

Lizard  Pbint,  and  the  steatites  in  other  placet, .  as 
very  likely  to  make  good  porcelain  7t.  Dr.  Camp* 
bell  also,  who  seems  to  understand  this  sabjeet, 
strongly  recommends  this  article  to  be  employed  in 
the  manufacture  of  china  7S.  Whether  steatites  will 
improve  the  body  of  the  ware,  as  above  mentioned,  I 
do  not  know,  but  I  know  it  has  been  used  at  some 
of  our  porcelain  works  in  considerable  quantities. ' 

Should  the  English  potter  be  able  to  make  die 
body  of  his  ware  equal  to  that  of  the  East,  it  woaU 
then  be  necessary,  as  I  apprehend,  to  discover  adnie 
other  material  for  the  glaze ;  because,  if  our  ware 
were  burnt,  as  it  is  in  China,  by  one  operation,  tiie 
earth  would  contract  more  than  the  glaze,  and  eoa« 
sequently  the  latter  must  either  crack,  or  portiaHy 
fly  off. 

I  hazard  this  opinion,  because  I  know  that  in 
China  the  glaze  is  infinitely  better  than  ours,  inas- 
much as  it  consists  purely  of  fel-spar,  and  is  ao  ex. 
tremely  hard  that  it  cannot  be  operated  upon  by  nstf 
of  our  common  cutting  instruments.  Even  the 
wheel  of  the  glass-grinder  will  not  touch  it ;  whereas 

ours  becomes  scratched  and  defaced  by  commonusage 
and  ordinary  wear  74. 

If  the  glaze  on  porcelain  be  too  thick,  this  will 
occasion  it  to  break ;  it  is  therefore  important  to  ap- 


^  Woodward*s  History  ofFotsUt,  vol.  i.  page  6. 

^'  PoUtical  Survey  of  Great  BriUun,  vol.  ii.  page  19. 

^*  This  remark  18  not  applicable  to  aU  the  European  porodaia  I 
for  that  made  in  Saxony,  and  in  some  other  parts  of  Germany,  is 
equal  to  the  best  Oriental  china. 


-^   AND  PORCELAIN.  129 

-ply.m  thin  glase,  the  fusibility  of  which  should  be  as 
vnmAj  as  possible  approaching  to  that  of  the  body 
of  the  ware,  in  order  that  the  combination  nn^y  be 
JBOie  tntimate  and  lasting.  Cbaptal  djcseribes  a 
l^bM  which  perhaps  our  potters  may  imitate  with 
adiaatage.  *'  It  consists,**  says  he,  '*  in  mixing  the 
Mrth  of  Murviel  in  water,  and  dipping  the  pottery 
diefdin.  When  dry,  they  are  plunged  into  a  second 
water,  in  which  levigated  green  glass  is  mixed* 
lUa  covering  of  vitreous  powder  fuses  with  the  clay 
of.  Murviel,  and  the  result  is  a  very  smooth,  very 
wfaitei  and  very  cheap  glazing  75. 

31ie  great  durability  of  the  Oriental  china  is  its 
nain  excellence.  We  make  porcelain  in  this  coun- 
trf  whidi  is  equally  beautiful ;  and,  if  the  symmetry 
of  the  figures  and  the  merit  of  the  painting  be  con- 
ttdeied,  fieur  more  elegant,  although  it  possesses  a 
Issa  degree  of  tenacity  and  hardness  76.  We  have, 
indeed,  lately  noticed  the  introduction  of  what  is 
called  stone-china,  which  is  made  very  thick  and 
dttnasy  to  imitate  some  of  the  best  productions  of 
the  jBast :  the  glaze  upon  this,  however,  is  as  poor 
and  aoft  as  upon  other  English  china. 

Is  it  not  natural  then  to  ask.  Why  do  not  our 

P  Cluiptal*B  JSIementf  o/'CA^mu/ry,  English  Transl.,  vol  ii. 
|M«88. 

^  It  in  probable  that  the  heaviest  and  most  compact  china 
wXL  always  prove  to  be  the  most  durable.  Dr.  Watson,  in 
t^iM  the  specific  gravity  of  several  spedmens  of  pottery, 
iMnd  that  a  cubic  foot  of  cream-coloured  ware  weighed  1988 
avoirdupois  I  of  flint  ware,  2188  ounces;  of  Bristol 
2340  oupces  >  and  of  East  Indian  china,  2346 


VOL.  II.  K 


130  ON   EARTHENWARE 

pottdrs  make  use  df  a  better  glaze  77^  especially  as  the 
county  of  Cornwall  can  furnish  felspar  in  abundance 
and  af  a  reasonable  price  ? 

The  true  answer  to  this  question  seems  to  be 
this :  that  our  ovens  are  not  capable  of  fusing  $, 
glaze  similar  to  that  which  is  employed  in  China  7*. 
The  heat  of  the  potter*s  oven  in  that  country  must 
be  tremendous.  The  materials  could  not  be  vi- 
trified as  we  see  them,  with  less  heat  than  would 
fuse  Cornish  granite. 

An  ingenious  mode  of  discovering  wheb  the 

glaze  on  china  is  not  sufficiently  hard^  has  beea 

giving  by  the  late  Mr.  Nicholson.    It  consists  in 

dropping  a  small  quantity  of  strong  ink  upon  it,  diy^ 

ing  this  before  the  fire,  and  then  washing  it.    If  the 

gla^e  be  too  soft,  an  indelible  brown  stain  will )» 
main  upon  it.  77 

It  must  here  be  remarked,  that  for  those  wfad 
-choose  to  incur  the  expense,  there  is  poroelnn 
manufactured  in  soiAe  parts  of  this  kingdom  wUdi 

is  more  durable  than  (hat  commonly  made  in  the 



^  In  Uie  vear  1 803,  Professor  Proust,  of  Madrid,  paUUicd 
some  remarks  on  the  glazes  of  pottery.  See  his  paper  in  the 
Joamol  de  Phffsiqiie,  under  the  tiUe  of/'  A  Memoir  on  tinainff 
.Copper  Vessels."  Extracts  from  this  production  wiU  be  firona 
in  uie  Philosophical  Magazine,  vol.  xxi.  p.  313. 

^  The  fbsitelity  of  the  earthy  compounds  depends  iipoa  their 
proportions.  Lime  and  clay  are  separately  infusible ;  but,  in  das 
proportions,  the  mixture  is  capable  of  forming  a  perfect  |;lass. 

'0  Chemical  Dictionary,  article  Pottery ,  Svo,  Loadoa^  1809. 

^  CampbeirsPoIt<ica2  Survey  of  Great  Briiain,  voK  ii.jp.  18. 

*>  Dresden  diina  was  formerly  in  such  hifh  estimatkni  in  iWs 
country,  that  in  the  year  1763  a  single  serviee  of  it  was  sold  hf 
auction  m  London,  at  Mr.  Uhlhoflfs  sale,  for  1 1 5  poniids. 
tleman^s  Magaz.  vol.  xxxiii.  p.  312. 


AND   H>ECfiSLAIN.  ,  131 

Staffoifdshire  potteri^.  Such  was  formerly  the  Boiir 
dniit,  und  that  also  made  at  Chelsea  ^ ;  and  I  have 
been  er^bly  itiformed,  the  china  now  manufactured 
at  Worcester  is  nearly  equal  to  the  best  Dresden  st, 
or  to  the  true  Nankin,  in  all  those  properties  which 
gife  the  hiost  value  to  this  production  df  art. 

h  is  worthy  of  dbservatioii,  that  while  the  King 
of  Finissia  Was  pursuing  every  possible  method  of 
adviumng  and  extending  the  manufoctory  at  Bar- 
fin  **9  the  works  at  Worcester  continued  to  improve 
yew  after  year,  without  psLtronage^  ahd  that  they 
wcM  brought  to  their  present  perfection  solely  by 
the  genius  and  enterprise  of  the  proprietors. 

Of  late  years  a  porcelain  manufacftdry  of  consii* 
deisbl^  consequence  has  been  established  at  Coal- 
^ert  in  the  county  of  Salop.  Some  peculiar  kindi 
of  Cliina»  both  serviceable  and  beautiful,  are  pro^ 
at  these  works. 


Tlie  common  heat  of  the  potter*s  kiln  in  En-^ 
l^aiUl  is  about  6(f  of  Wedgwood's  pyrometer  ^, 
fMA  is  equal  to  8*877  degrees  of  Fahrenheit  fof 


*»■ 


Uti^mim^ 


*  la  order  to  enoDUrage  this  manuftustory,  and  make  its  pre-. 
jlMlkMi|iiiiore  generally  known^  the  King  made  presents  of 
esi^phrte  setvices  of  the  Dresden  porcelain  to  all  the  soTereign 
idecctia  Germany. 
^  iPor.  an  account  of  the  construction  of  Wedgwood's  pyro- 
iter  fhe  reader  is  referred  to  the  Ixxiid  and  several  of  the  sub- 
aa^aetit  volumes  of  the  Pkilosophkal  Trmuaetiom,  or  to  Mur- 
lajr^s  Sffsiem  of  Chemistry,  vol.  i.  p.  150.  The  pieces  of  baked 
dHh  which  he  employed  for  the  pyrometers  were  andysed  by 
VpM|ilr1in,  who  states  them  to  have  consisted  of  silica  64,  alu- 
auaa  25,  charcoal  6^  oxide  of  iron  0*2^  water  6*2.  Nicholson's 
4to  Journal,  vol.  iii.  p.  265. 

k2 


132  O^   EARTHENWARE 

the  cheapest  cream-coloured  ware,  and  ^boat  80^  of 
Wedgwood  for  the  Staffordshire  porcelun ;  though 
I  have  reason  to  believe  that  the  manubcturers  <tf 
the  best  cream-coloured  ware  seldom  allow  the  heat 
of  the  kiln  to  exceed  45^  of  Wedgwood*8  pyrometec. 
It  must  be  recollected,  however,  that  we  fire  twkc^ 
and  that  these  heats  refer  to  what  are  employed  in 
converting  the  ware  into  what  is  called  biscuit. 

I  am  not  myself  acquainted  with  the  respective 
temperatures  at  which  the  other  porcelain  maqufae- 
turers  fire  their  ware ;  but  Dr.  Henry  has  stated  that 
the  Worcester  china  vitrifies  at  94,  that  the  Chel- 
sea porcelain  is  fired  at  105,  and  the  Derby  at  112 
of  Wedgwood. 

.  In  the  Staffordshire  potteries  the  temperature  of 
the  gloss-oven  is  generally  about  10^  of  Wedgwood, 
or  2  *3/7  degrees  less  of  Fahrenhdt  than  the  heat  of 
the  biscuit  oven.  The  reason  of  diis  is,  that  theie 
may  never  be  any  danger  of  the  ware,  in  this  last 
operation,  undergoing  a  higher  degree  of  heat  than 
it  experienced  in  the  first  burning ;  it  being  abso- 
lutely necessary  for  the  operator  to  be  carefid  of 
this  point,  because,  as  clay  will  continue  to  contract 
by  every  addition  of  heat,  it  must  follow,  that  should 
it  ever  be  pushed  beyond  that  degree  which  it  aus- 
tuned  in  the  state  of  biscuit,  the  body  of  the  ware 
would  experience  a  greater  contraction,  and  conse- 
quently every  piece  within  the  oven  would  either 
become  crooked,  or  the  glaze  would  be  injured. 
The  firing  of  the  gloss-oven  generally  requires  from 
12  to  14  hours. 


AND  PORCELAIN.  133 

The  gitnng  for    the  common  cream-coloured 
earthenware  consists  usually  of  certain  portions  of 
fithaige  of  lead  and  ground  flints,  mixed  with  as 
rnoeh  water  as  will  form  them  to  the  consistence  of 
thin  eream,  which  is  found  to  he  a  state  the  most 
soitaUe  for  the  immersion  of  the  ware.    One  hun- 
dred pounds  of  litharge  and  40  pounds  of  ground 
ffints  are  the  common  proportions ;  hut  it  is  usual 
%i4ake  80  pounds  of  Cornish  granite  to  100  pounds 
of  lilbarge,  whenever  that  is  used  instead  of  flintsj 
Flint  is  the  article  which  is  employed  in  making 
gliae^ibr  the  porcelain  as  well  as  for  the  coarse 
(earthenware,  it  being  nearly  all  silica.     Klaproth 
found  common  flint  to  consist  of  ignited  silica  98 
parts,  Ume  0*50,  alumina  0*25,  ignited  oxide  of 
inm  0*25  parts,  volatile  in  the  fire,  1 .  84 

For  the  finer  kinds  of  earthenware  and  for  porce- 
kin,  it  is  made  with  white  lead,  ground  flint  glass, 
ground  silica,  and  common  salt.  Some  manufac- 
torers^  however,  add  other  materials ;  most  of  those 
who  auperintend  this  department  imagining  that 
dM!y  possess  a  valuable  secret,  and  that  in  conse- 
qnence  of  it  their  glaze  is  much  better  or  cheaper 
dmn  that  of  others. 

In  all  manufactories  it  is  found  necessary  to  vary 
die  composition  of  the  glaze,  according  to  the  na- 
ture of  the  materials  which  form  the  body  of  the 
ware ;  and  the  former  cannot  be  perfect  unless  it  be 


^  Klaproth*8  Anatyticdl  Eisays,Yo\.  i,  p.  42. 


134  ON  sarthinwake 

'eapaUe  of  eontraGling  and  lixpsndifig  bf  beftt  And 
coU,  ia  tl^e  same  pfoportkm  as  the  ware  itself  «riH 
iQontraot  or  expand bjr diange  of  teilipflratiin^.Tbt 
miter  of  the  articde  Porodain  ia  tbe-FVemb  CSice 
mieal  Dictionary  yerjr  foropedjr  fanarjis  that,  f^a 
glass  wluch  malm  a  fine  glaadng  for  one  pmdditeb 
wiUiaakea  wrjr.bad  glaapg  fot  anothw  spit/of 
fioroelain,  will  erackin  nuflty  plaoss^  and  faafaUt 
Instre.  The  gla«ng  must  be  apjiropriafied  tp  die 
density  of  the  wars  and  the  ingiedients  of  itsmOiT 
position.^ 

As  the  number  of  potters  has  inmased  fMjr 
mueh  ^thin  the  last  SO  years,  the  competitiM  hm 
become  so  great  that  every  manufiietwer  is  wider 
the  necesnt]^  of  consulting  economy,  and  of  ^onwr 
times  sacrifidng  the  utili^  and  gioodaess  pi  lim 
ware,  for  the  sake  ather  of  appearances  or  of  adopts 
ing  the  dieltpest  modes  of  manu&cture  that  cap  be 
devised. 

To  one  of  these  causes,  may  he  atlnbut^  :the 
introduction  oibonesintQ  the  manufacture  ^ poiMr 
lain.  Of  thb  article  there  is  now  so  large  a  oon? 
sumption  in  the  Staffordshire  potteries,  that  some 
of  the  great  manufacturers  have  extensive  roeoss 
which  are  used  solely  for  the  reception  of  bones. 
Animal  bones  are  composed  of  lime  and  phosphone 
acid,  in  different  proportions  according  to  the  age 
and  species  of  the  respective  animak  to  which  they 
belonged.  These  are  either  bought  of  the  indigent 
bone-collectors  in  the  country,  and  then  burnt  and 
ground  by  the  potter,  or  they  are  purchased  ready 


buf  at  wd  gTQimd  for  use,  diiieody  from  thpse  whp 
distill  mlatite  alkali  qr  spirit  .<)f  h^ftshorik  ][( ii^^ 
kowever^.  gcpuerally  known  to  the  ohina  manufnet 
tuners,  that  this  article  .is  ipjutioiii$  to  the  textute  of 
the  ivare;  its;  mo,  theveforey  cannot  be  justified  on 
any  account  whatever. 

'  I  fdlow  that  ground  bon^  have  the  c^eet  of  ren- 
dqpiiig  the  goods  very  white,  and  also  that  they  prot 
diott  ^:  transparent  appearance ;  but  I  doubt  whe* 
^Wf  Uiis  be  a  real  transparency,  or  only  a  deception. 
Thus  far,  however,  one  may  venture  to  assert,  that 
the  modern  English  porcelain,  which  has  the  usual 
proportion  of  bones  in  its  composition,  is  of  niuch 
kis  specific  gravity  than  it  ought  to  be  ^,  and  is 
lOy  iq[it  to  crack  with  hot  water.  As  the  base  of 
aainiaL  bones  is  phosphate  of  lime,  it  might  be 
moith.  while  for  the  potter  who  is  determined  to 
use  bones,  to  try  whether  the  native  phosphate  of 
lime^  can  be  useful  in  making  porcelain^  and  if 
phoqphate  of  alumina  may  also  be  employed  in  this 
maiiu&cture. 

.  la  returning  to  the  subject  of  glazing,  it  will  be 
proper  to  state  that  the  common  earthenware  would 
be  too  porous,  and  many  kinds  of  fluids  would  pass 

• 

^  For  the  specific  gravity  of  good  porcelain^  see  Note  76,  page 
129. 

^'  A  memoir  by  Hassenfratz  '^  On  the  native  phosphate  of 
lime**  may  be  seen  in  the  Annales  de  Clumie^  tome  i.  page  191  • 
likewise  some  "  Remarks  on  phosphate  of  alumina  and  on  a 
immntain  of  calcareous  phosphate^*'  by  Proust^  in  the  same 
Tohmie^page  196. 


136  ON   BAETHBNWARIS 

through  it)  were  it  not  defended  by  an  artifidal 
eovering  or  permanent  glaze.  It  became  necessary 
therefore  to  contrive  a  composition  which  aboidd 
vitrify  and  flow  in  the  fire»  so  as  to  cover  these 
materials  of  earth  mth  an  entire  coating  of  perfisM 
glass. 

Such  a  glaze  having  been  found  in  a  mixture  of 
oxide  of  lead  ^  and  silica^,  as  mentioned  aboive,  a 
certain  proportion  of  each  of  these,  ground  to  an 
impalpable  powder,  is  thrown  into  a  tub  of  water, 
and  stirred  therein  till  the  mixed  powder  becomes 
suspended  and  uniformly  dispersed  throughout  the ' 
fluid. 

The  glaze  having  been  thus  prepared,  it  is  ap^ 
plied  to  the  ware  in  the  following  manner.  A 
workman  to  whom  this  duty  belongs,  receives  the 
goods  from  a  boy,  who  delivers  them  to  him  one  at 
a  time;  and  as  he  receives  each  single  piece,  he 
dips  it  in  the  liquid,  lets  it  drain  for  a  moment, 
and  then,  placing  it  on  a  board  standing  beade 
him,  he  is  ready  to  receive  another  piece,  which  he 
immerses  in  like  manner. 

It  is  in  this  way  that  the  glaze  is  applied  to  all 
the  various  articles  which  are  made  of  the  common 
earthenware ;  and  as  it  is  only  partially  baked  or  in 
the  state  of  biscuit,  when  it  is  immersed  in  the  glaze, 

*^  The  French  potten,  instead  of  an  oxide  of  lead,  use  the 
common  galena  or  sulphuret  of  lead  for  this  purpose. 

"  Silica  was  formerly  known  by  the  name  of  the  vUryiahb 
earth,  because  mixed  with  an  aDoui  it  possesses  the  properly  of 
fusing  into  a  transparent  glass. 


AMB  POKCfiLArN.    •  137 

t  raffidcnt  quantity  attaches  itself  to  the  fliurfieide, 
whieh^  when  it  has  been  fosed,  will  form  over  it 
a  49oaiplete  covering  of  glass.  This  mixture  has 
great  fusibility,  though  silica  alone  does  not  melt 
in  the  focus  of  the  most  powerful  burning  mirror. 
Mr.  Hare,  however,  fused  it  completely  by  submit- 
Aig  it  to  the  flame  of  a  stream  of  mixed  oxjrgeri  and 
hydrogen  gases,  and  found  that  it  formed  when  cold 
a  kind  of  enamel  ^. 

There  are,  however,  strong  objections  to  this 
mode  of  glaring  pottery.  The  men  who  work  in 
it  for  a  considerable  time  are  apt  to  become  para- 
]f6c,  probably  from  the  lead  90 ;  and  where  acids, 
ivlnch  have  the  power  of  dissolving  the  lead,  are 
emplcqred  in  preparing  condiments  for  our  food, 
sndi  a  glaze  must  be  extremely  unwholesome. 

Aware  of  the  pernicious  effects  of  lead,  when 
taken  into  the  stomach,  M.  Fourmy,  an  ingenious 
manuAicturer  at  Paris,  has  prepared  water- coolers, 
in  winch  he  has  employed  lava  for  the  glaze,  instead 
of  the  deleterious  metallic  covering  which  is  more 
eommonly  used  for  that  purpose.  Pumice-stone 
has  also,  as  I  understand,  been  used  for  covering 
eardienware,  and  with  very  good  effect. 

Some  of  the  French  potters,  at  the  suggestion  of 
Cbaptal,  have  substituted  common  flint  glass  for 
lead  in  their  glaring,  and  have  found  it  not  only 


^  PkUotophkal  Magazine,  vol.  xiv.  p.  304. 
^  Some  directions  for  the  prerention  of  this  mslady  will  be 
bond  in  The  Chemical  Catecfusm,  tenth  Edition,  p.  tOl. 


LS8  ON  MAMTmmmAME 

safer,  but  more  eeonomical.  They  grind  broken 
flint  glass  to  a  fine  powder ;  and  when  this  is  mixed 
with  a  due  portioa  of  elay  and  wafer,,  the  goods  ant 
dipped  into  it,  as  onr  potters  dip  their  ware* 

The  potters  of  Bristol  and  J^iambeth  glaw  thdf 
stone  ware  witb  common  salt.  When  the  0ven  hw 
acquired  a  certaia  temperature,  the  salt  is  eastiq^ 
and  the  vapours  arising  from  it  attach  theoEiadhm 
to  the  goods,  and  completely  cover  them.  Tb^ 
alkali  of  the  salt  probably  combines  witb  the  dUca 
of  the  ware,  and  forms  a  true  glass  upon  their  sur- 
faces. 

The  English  potters  are  however  fond  of  usiQg 
a  glaze  made  with  lead  and  silica,  because,  wlpitp 
ever  the  articles  may  be  which  are  employed  for  tbit 
purpose,  it  is  necessary  to  give  them  a  he(it  suffi- 
cient to  idtrify  the  materials  and  convert  them  mto 
a  peirfect  glass ;  and  when  the  best  articles  are  Buude 
use  of  in  forming  a  glaze,  the  heat  which  is  em^ 
ployed  must  be  very  considerable;  whereas  lead 
alone  will  readily  fiise  and  form  a  glaze  that  may  be 
finished  at  a  very  low  heat  indeed.  This,  however, 
if  used  alone,  would  make  a  glaze  too  soft,  andfo 
extremely  fusible  that  it  would  be  apt  to  run  veqr 
much  towards  the  lower  parts  of  the  ware,  and  leave 
the  upper  ones  imperfectly  covered. 

Half  a  century  ago  our  potters  were  so  oardess 
in  their  manner  of  applying  the  salt  glaze  to  the 
stone  wares  of  Stafibrdshire,  that  large  importations 
were  made  from  FVance  and  Holland,  where  the 
manufacture  was  better  conducted ;  and  had  it  not 


AKD  'BOnCBLAIN«  139 

bMR  far  Mr«  Wedgwood^s  timely  indention  of  the 
Qnesn's  ivare^  it  is  probable  that  the  best  part  of  the 
thMie  weald  long  ago  have  been  lost  to  tins  oountry. 
A  vari^  is  sometiipes  given  to  thp  glasse  by  mbc- 
ia^  eertain  didder  of  the  metals,  especially  that  of 
esMcry  or  Mbemnse  the  filings  of  copper ;  but  this 
enotoed  glaae  is  generdly  applied  only  partially. 
Mad  merely  for  goods  of  inferior  quality.  The 
edges  of  oommoq  plates  are  sometimes  coloured  by 
dda  method.  9i 

It  k  about  sixty  years  since  the  plain  cream-eo- 
leuicd  ware  of  Mp.  Wedgwood  was  introduced.  At 
that  time  this  unadorned  and  simple  article  was 
UiOQght  sufficient  for  every  purpose  where  porce- 
hio  was  not  employed  ;  and  the  neatness  and  olean* 
Bnesa  of  its  appearance  gave  it  sudi  a  decided  pre- 
fbrenoe  that  her  late  Majesty  allowed  the  worthy  in- 
ventor to  call  it  QueerCs'tuare ;  but,  when  a  de- 
mand arose  for  more  expensive  services  of  pottery^, 
rteoorse  was  had  to  the  pencil.  From  that  period 
a  great  number  of  artists  have  been  constantly  em* 
jdoyed  in  painting  earthenware  as  well  as  porcelain^ 
and  often  great  taste  is  displayed  in  these  produc- 
tions. 

It  must  not  however  be  imagined  that  painting 
on  earthenware  was  a  new  invention.     The  paint* 

^  The  beautiful  black  glaze^  which  is  seen  on  a  peculiar  sort 
of  ware  made  at  Nottingham^  is  composed  of  2 1  parts  by  weight 
of  while  lead,  5  of  flints,  and  3  of  the  oxide  of  manganicse.  Up- 
son's Chemiciil  Essays,  toI  ii.  page  271. 


140  ON   EARTHENWARE 

ings  of  the  ancients  of  this  kind  are  rare  and  valo- 
able.  The  Marquis  Marcello  Vehuti,  in  lib  de- 
scription of  the  curiosities  found  in  the  iineiaBt  ciljr 
of  Heraclea^  speaks  of  one  upon  slaie,  representing 
a  muse  crowned  mth  Uiurd,  with  a  musical  instm^ 
ment  hanging  on  her  shoulders,  which  was  faaaA 
in  one  of  the  subterraneous  cavities,  and  is  described 
as  being  then  in  the  possession  of  Signor  Nioob 
Vagnucci  of  Cortona,  one  of  the  principal  Support- 
ers of  the  Academy  of  Tuscany  £^. 

Nevertheless,  it  must  not  be  concealed  thatChap- 
tal  has  shown,  that  the  Romans  of  the  first  oenCory 
were  not  acquainted  with  any  of  the  metallic  fluaes 
with  which  die  modems  fix  and  vitrify  the  coverings 
of  their  pottery.  For  the  particulars  consult  his  vcqr 
instructive  account  of  certain  colours  which  weoe 
found  in  the  shop  of  a  colour^merchant  in  one  ci  dm 
streets  of  the  ancient  Pbmpeia,  especially  as  he  has 
there  told  us  what  was  the  composition  of  the  glaae 
which  the  potters  of  that  day  did  actually  emplogf  9. 

To  return  to  the  consideration  of  the  paintings  on 
English  earthenware,  it  must  be  observed  that  the 
variety  of  effect  is  produced  by  means  of  the  diffe- 
rent metallic  oxides,  each  of  which  affords  a  diflferent 
colour,  and  these  colours  are  again  multiplied  by 
such  mixtures  of  two  or  more  of  the  oxidized  metals, 
as  experience  has  shown  to  be  useful. 

In  employing  these  various  colours,  the  ground 


»  Skurray's  TVojif loliofi,  8vo,  London,  1750,  page  107. 
^  Jnnales  de  Chimie,  tome  Ixx,  p.  22. 


AHD  PORCELAIN.  141 

6odde  is  first  mixed  with  a  prepared  flux»  which  is 
tlso  redoeed  to  an  impalpable  powder,  and  then 
this  mixture  is  well  incorporated  with  gum  water, 
the  acid  of  tar,  oil  of  turpentine,  or  some  other  es* 
lential  oil,  as  may  be  most  suitable,  in  point  of  ex* 
penae  or  otherwise,  for  the  goods  on  which  it  is  to 
be  employed.  The  fluids  are  used  merely  to  lay  on 
the  colour ;  for  it  u  necessary  that,  whatever  oil  be 
cuqployed,  it  should  have  the  property  of  evapora* 
tiDg  entirely. 

The  preparations  which  are  commonly  used,  are 
the  metallic  oxides  and  their  combinations  with 
aei^  Thus  cobalt  yields  a  blue ;  antimony  and 
sihrer  g^ve  yellows  and  oranges ;  platinum  a  silver 
oolaurO*;  gold  violet  and  purple;  copper  the 
gtttOM ;  while  the  reds,  the  browns,  and  the  blacks, 
aie  derived  from  iron. 

The  oxide  of  cobalt  employed  in  the  pottery 
b  usually  prepared  from  zaffre,  which  is  an  expen- 
jBve. article  imported  from  Saxony,  though  a  few 
years  ago  very  fine  oxide  of  cobalt  was  procured 
fiNmi  G>rnwall ;  for  preparing  autimonial  yellows, 
the  crude  antimony  is  first  calcined  with  four  times 
its  weight  of  nitre,  and  is  then  mixed  with  a  cer- 
tain proportion  of  vitrified  lead.  The  precipitate  of 
Cassius  is  the  article  which  is  generally  used  for  the 
production  of  violets  and  purples,  though  sometimes 


**  Some  obsenrations  by  Klaprolhon  the  uses  of  platinum  in 
pottery^  may  be  seen  in  the  Pfdl,  Mag.  vol.  xvii.  p.  135. 


14S  ON   EARTBBNWARE 

the  oxide  of  gold  precipated  by  bopper  is  employisd. 
For  gteens»  the  copper  has  usually  been  taken  in  thte 
state  of  a  precipitate ;  but  some  potters  httvefontid 
an  artible  of  more  value  in  thfe  pure  oxide  of  eoppeir^ 
which  they  prociiie  by  placing  sheets  of  copper  Ift 
the  oVens  ih  which  the  ware  is  glaced :  and  it  haft 
lately  bden  discovered  that  a  small  portion  of  eopi- 
per  mixed  with  the  iron  tery  much  increases  dte  ib^ 
tensity  of  the  blacks  on  earthenwan^.  BesidlSi; 
iron  itself  is  capable  of  giving  a  great  variety  of  M^ 
lours,  according  to  the  way  in  which  it  is  managed. 
Fbr  instance,  the  black  oxide  of  this  liietal  prodcloed 
by  the  action  of  heated  air  only,  will  be  a  v&y  dti^ 
fei«nt  article  when  used  as  a  pigment  from  an  okldtt 
of  iron  prepared  by  other  means. 

It  is  here  necessary  to  remark^  that  in  palttf£^ 
on  the  biscuit  no  oil  is  us^ ;  the  inetaUic  Oldltes 
are  mixed  with  water  only ;  and  it  is  owing  lb  tMH 
circumstance  that  such  ware  may  be  glazed  at  <ibce 
without  being  put  into  an  oven,  as  is  the  lease  wilil 
those  goods  which  are  known  by  the  appdlatioti  ef 

For  certain  purposes,  however,  the  pldndng  li 
performed  tgMm  the  glaze,  as  some  colours  iMttM 
be  injured,  and  others  destroyed^  by  the  heat  of  thd 
glos^oven«  Thus,  Where  iron  is  employed  to  pro* 
duce  blacks  or  browns^  the  painting  is  always  done 
tgnm  the  glaze ;  the  ware  is  then  finished  in  an  ena^ 
mel-oven,  at  about  6^  of  Wedgwood's  pyrometer. 

Some  metallic  oxides  are  used  for  another  inten- 
tion besides  that  of  pidnting,  viz.  for  the  purpose  of 


AND   PORCELAIN.  143 

covering  the  ware  entirely  on  the  exterior,  as  is  the 
case  when  the  sulphuret  of  antimony  is  employed 
for  producing  a  common  kind  of  yellow  ware ;  and 
also  for  those  articles  known  by  the  names  of  gold 
and  3ILVRK  LUSTRE.  The  first  of  these  lustres  it 
effected  by  means  of  gold,  the  latter  by  the  oxide  of 
platinum.  For  gilding  porcelain  the  metal  is  used 
in  its  metallic  state.  To  procure  it  in  a  pulverized 
form,  it  is  dissolved  in  aqua  regia,  and  then  the  acid 
is  driven  off  by  heat,  and  the  gold  remains  ;  this  is 
then  mixed  with  borax  and  gum-water,  which  form 
together  a  proper  vehicle  for  fixing  it  upon  the  goods. 
After  this  it  is  baked,  and  finished  by  burnishing; 
For  preparing  the  lustre  ware,  as  it  is  called,  the 
oxide,  of  whatever  kind  it  may  be,  is  mixed  with 
some  one  of  the  essential  oils,  and  in  that  state  it  is 
brushed  upon  the  surface  of  the  articles.  It  should 
have  been  observed,  that  when  the  manufacturer  in- 
tends to  make  lustre-ware,  the  articles  are  glazed 
before  the  gold  or  the  platinum  is  applied.  For 
gold-lasiie,  the  ware  is  made  of  a  red  clay,  which, 
when  burnt  and  glazed,  shows  so  much  of  its  colour 
through  the  covering  af  gold,  as  is  sufficient  to  give 
the  goods  that  peculiar  brown  tint  which  is  always 
observable  on  this  singular  kind  of  pottery. 

When  the  metallic  oxide  has  been  properly  ap- 
plied to  the  surface  of  the  goods,  they  are  carried 
to  an  enamelling-oven,  where  the  heat  dissipates 
the  oxygen,  and  restores  these  precious  metals  to 
their  metallic  state, — I  cannot  say  quite  to  their  pri- 
mitive metallic  brilliancy.because  this  is  often  much 


144  ON   EARTHKNWARE 

iDJuredbjr  the  fluid  menstruum  employed  in  the  ope- 
ration.   The  great  difference  which  there  is  in  the 
appearance,  of  this  ware,  especially  in  that  which  is 
covered  with  platinum^  can  only  be  thus  accounted 
for.    Some  of  it  looks  like  silver,  while  the  articles 
from  other  manufiactories  are  more  like  iron  oc  steel* 
I  once  imagined  that  this  variation  might  arise 
from  a  different  mode  of  preparing  the  o»de  of  pla- 
tinum.   I  therefore  prepared  two  samples,  of  this 
oxide,  the  one  precipitated  by  caustic  aamKinia» 
and  the  other  by  muriate  of  ammonia ;  but,  when  I 
had  them  tried  by  an  experienced  potter,  both  pro- 
duced precisely  the  same  colour. 
'  I  wish  some  manu&cturer  would  attempt  to  pro- 
duce this  ware  by  mixing  the  oxide  of  platinum  with 
pure  water  only ;  for  in  that  case  I  am  persuaded 
the  ware  when  finished  would  be  as  white  as  the  pla- 
tinum itself. 

The  potters  of  Eng^d  have  derived  great  advan- 
tage from  the  introduction  of  the  printing  press. 
The  use  of  this  valuable  machine,  which  is  com* 
paratively  of  late  date,  has  enabled  these  manufise- 
turers  to  produce  a  greater  variety  of  patterns,  and 
of  neater  execution,  than  could  possibly  be  acquired 
at  a  small  expense  by  the  pendl. 

As  this  is  a  curious  branch  of  the  business,  it 
will  be  proper  to  describe  it  a  little  more  particularly. 
It  consists  in  first  printing  the  intended  pattern 
with  some  metallic  colour,  chiefly  the  oxide  of  cobalt^ 
on  what  is  called  silver  paper,  and  then  in  transfer- 


ANU    POHCELAIN. 


145 


ring  thecolourfrom  the  paper  to  the  surface  of  the 
porcelain.  This  style  of  colouring  earthenware  is  a 
very  successful  imitation  of  the  old  blue  porcelain  of 
China,  and  of  late  years  has  been  the  means  of 
extending  the  consumption  of  British  pottery 
throughout  Europe  more  than  any  other  improve- 
ment in  the  manufactory ;  for  the  potters  of 
China  are  totally  unacquainted  with  the  printing-  . 
press,  and  consequently  all  their  designs  are  pro- 
duced by  the  pencil  alone. 

This  mode  of  imparting  designs  to  the  surface  of 
earthenware  or  porcelain,  and  which  is  known  in 
the  trade  by  the  appellation  of  blue  printing,  is 
managed  somewhat  in  the  following  manner  : 

One  man  constantly  attends  the  press,  which  is 
very  similar  to  our  cunimon  copper-plate  printing- 
press  ;  and  as  soon  as  he  has  applied  the  colour — 
which  is  laid  on  the  copper  in  the  same  manner  as 
the  copper-plate  printers  apply  the  ink — he  lays  it 
upon  a  hot  iron,  to  thin  tlie  oil  with  which  the  co- 
lour is  always  mixed  for  this  purpose.  The  oil 
which  is  used  is  a  peculiar  preparation  of  boiled 
linseed  oil.  When  the  colour  upon  the  copper- 
plate is  thus  reduced  to  a  proper  consistence,  a  sheet 
of  silver  paper  is  laid  over  it,  and  the  workman 
passes  it,  with  the  paper,  through  the  press. 

For  blue  printing,  the  oxide  of  cobalt  is  the  only 
mineral  which  is  employed.  This  is  largely  pre- 
pared in  the  Stafibrdshire  potteries,  and  sells  from 
40*.  to  (it)*,  the  pound,  according  to  its  intensity 
and  goodness.     Indeed,  such  improvements  have 


146  ON   EARTHENWARE 

been  made  in  the  manufacture  of  this  colour,  that 
the  Chinese  potters  are  iiow  supplied  from  England 
with  all  the  cobalt  they  consume- 
When  the  paper  comes  from  the  printing*presa^ 
it  is,  of  course,  found  to  be  stamped  with  the*  in* 
tended  pattern.  It  is  then  delivered,  while  wet  with 
the  colour,  to  a  girl,  who  cuts  off  the  superfluoai 
.paper  with  a  pair  of  scissars,  and  passes  it  to  another 
.^rl,  who  immediately  applies  it  to  a  piece  of  biseint 
ware,  and  then  delivers  it  to  a  third,  who  fixes  it 
more  firmly  by  rubbing  it  very  hard  with  a  pieafc  of 
flannel  tightly  rolled  up  in  the  form  of  a  short  csp 
Under. 

The  design  of  this  hard  rubbing  is  to  force  the 
jcolour  into  the  pores  of  the  ware.  When  the  pi|peri 
which  have  been  thus  applied  have  lain  on  for  abwt 
.an  hour,  the  colour  is  generally  found  to  be  mffir 
ciently  fixed  to  admit  of  their  beiog  detaebedL 
This  is  effected  by  putting  the  articles  into  a  tub. of 
•water,  where  the  paper  soon  beeoiiies  soft  and 
pulpy  enough  to  allow  of  its  being  peeled  off  hjf 
gentle  friction,  leaving  the  fiill  impression  of  the 
pattern  upon  the  biscuit. 

Tlie  papers  having  been  removed,  the  waieis 
suffered  to  stand  a  sufficient  time  to  become  dry,« 
and  then  it  is  put  into  an  oven  at  a  low  lieat^  far 
the  purpose  of  dissipating  the  oil,  and  preparing  it 
for  receiving  the  glaze. 

It  must  be  obvious  that  it  is  necessary  to  empkqr 
a  glaee  which  is  transparent,  in  order  to  give  fttll 
effect  to  the  brilliancy  of  the  cobalt  colour. .  A 


AND   PORCELAIN.  147 

little  of  this  blue  oxide  is  also  generally  mixed  with 
tbe  glaze»  for  the  same  purpose  as  laundresses  epi* 
ploy  smak  with  their  starch,  viz.  to  increase  the 
whiteness,  by  subduing  any  yellow  tint  that  might 
otheiwise  impair  its  lustre. 

:  Here  I  eantiot  avoid  observing,  that  it  would  be 
ift  important  acqmsition  if  some  suitable  artiele, 
bilMd  of  oil,  could  be  discovered  for  mixing  with 
the '^  (flours  which  are  employed  in  printing  on 
Mrtkenware,  |tnd  which  could  be  of  such  a  nature  as 
not  to  require  to  be  burnt  off  previously  to  the  appli«- 
emioil  of  the  glaze.  It  appears  to  me  to  be  wort4i 
iridleto  institute  a  series'  of  experiments  for  this 
fiurticolar  object ;  because,  if  it  could  be  attained, 
iriMii  immense  quantities  of'  printed  goods,  besides 
which  are  ornamented  by  the  pencil,  might  be 
ipktely  finished  with  two  firings,  instead  of 
which,  on  the  present  plan,  such  goods  al* 
wi^  require !  Were  it  on  no  other  account  than 
itm  expense  of  this  vehicle,  it  is  desirable  to  find 
CMitetitute.  Some  of  the  first  enamel-painters 
ttunk  it  necessary  to  use  even  the  best  rectified 
oil  of  amber^  and  this,  of  late  years,  has  been  very 
cntly; 

-'Another  idea  occurs  to  me '  respecting  printed 
fWe^  which,  however  fanciful  it  may  now  appear, 
vili,  1  doubt  not,  some  time  or  other  be  realized. 
What  I  refer  to  is,  the  possibility  of  printing  two 
mt  three  diflferent  colours  at  onee,  like  the  Lancashire 
calico-printers.  This,  I  presume,  would  be  a  dis- 
tofeiy  of  great  importance  to  every  ttlaniiftfeturer  of 

l2 


148  ON    £ARTHBNWAR£ 

fine  earthenware  or  porcelidn.  See  Essay  IV.  vol.  i 
page  306,  and  also  the  engraved  plate,  No.  xi.  of 
the  machine  by  which  the  calico-printers .  impart 
two  or  three  distinct  colours  at  once.  ,i 

A  red  oxide  of  iron  more  brilliant  than  iuny  hi- 
therto employed  would  be  also  a  valuable  aoqiwi'- 
tion.  X^at  which  is  commonly  used  is  procured, 
from  green  vitriol  by  calcination ;  but  I  would  sog-i 
gest  that  a  much  fiber  colour  might  be  prepaiyed 
from  nitrate  of  iron,  and  advise  the  potter  to  tilfi? 
several  portions  of  it  and  precipitate  the  iron  by  tbe 
difierent  alkalies,  each  in  a  state  of  caustici^ ;  and 
by  these  means  he  would  readily  discover  wbidi 
produced  die  best  and  the  brightest  colour.  If 
four  distinct  precipitates  were  made,  viz.  one  with 
lime,  another  with  potash,  a  third  witli  soda,  aodft 
fourth  with  ammonia,  it  is  jurobable  they  would  be 
found  to  be  of  ytry  different  value  for  the  purpoae 
of  painting  on  china.  The  alkaline  carbonates- 
would  probably  give  precipitates  of  inferior  quali* 
ties ;  but  by  a  subsequent  calcination  the  Oarbonio: 
acid  would  be  separated,  and  something  valuable 
might  be  produced. 

In  making  this  experiment,  it  will  be  necessary 
to  prove  all  these  diffisrent  oxides  on  exactly  the 
same  kind  of  porcelMn,or  the  result  might  be  deeqK 
tive ;  for  it  is  well  known  to  practical  men,  that  the 
oxide  of  iron  will  not  produce  the  same  fine  red 
upon  common  china,  as  it  will  upon  the  hard  porce- 
lain which  is  glazed  with  felspar. 

The  residuum  wluch  is  produced  by  those  makers 


AND   PORCELAIN.  149 

of  aqua-fortis  ^rho  use  sulphate  of  iron  instead  of 
sulphuric  add,  might  answer  a  good  purpose,  if 
thoroughly  freed  from  the  alkaline  salt  which  it 
always  contains. 

It  was  my  intention  to  have  offered  some  remarks 
on  the  manufacture  of  crucibles,  retorts  and  other 
diettiical  vessels,  which  are  required  to  sustain  a 
great  heat ;  but  having  already  extended  this  Essay 
inoeh  beyond  its  proposed  limits^  I  must  content 
myself  with  merely  referring  to  those  authors  who 
have  already  treated  on  this  subject.  The  most  im- 
portant of  these  is  Pott,  who  wrote  a  work  expressly 
upon  it  9^,  as  I  have  already  mentioned  9^. 

I  shall  detain  the  reader,  however,  just  to  notice 
iliiit  the  chief  difficulty  which  the  manufacturer  finds 
ki  preparing  such  utensils  as  crucibles,  &c.  is,  that 
if  the  portion  of  silica  were  employed  which  is  neces- 
nry  to  give  sufficient  compactness,  the  ware  would, 
from  this  very  circumstance,  be  liable  to  become 
useless ;  because  many  of  our  chemical  articles  have 
die  property  of  dissolving  silica.  An  expedient  has 
therefore  been  adopted  of  mixing  a  large  portion  of 
qM  pottery  with  the  fresh  clay,  which  gives  it  the 
4esired  weight,  and  yet  is  not  liable  to  be  dissolved 
by  the  alkalies  like  pure  flint  or  sand. 
'  I  am  moreover  desirous  of  suggesting,  whether  it 

— I-  ■  -  I  -  r-" — 

**  lUhogeognosie  Pyrotechnique,  ou  Examen  Chymique  des 
Bgrret  et  des  Torres.  12mo,  2  vols.  Paris,  1753. 

^  See  p.  89  of  this  volume  -,  Nicholson's  Chemical  Dictionary, 
8fo,  article  Potteiy ;  or  The  French  Chemical  Dictionary,  un- 
der the  same  article.  .    . 


%:st^ 


150  ON   EARTHEN  WAKE 

might  not  be  advisable  to  mix  alumina  and  silica  in 
certain  proportions ;  and,  having  knciaded  this  mix- 
ture into  balls,  to  bum .  them  in  an  oven  at  Ae 
highest  temperature  the  mixture  can  endure ;  anid 
whether  such  a  preparation  would  not  be  more  suit- 
able.for  grinding  with  fresh  clay,  than  the  old  piots 
which  have  hitherto  been  used  for  this  purpose.  ..I 
imagine  that  vessels  made  in  this  way  would  stand 
heat  and  cold  better,  because  the  pores  of  th^  old 
stuff  are  often  so  close,  that  it  cannot  expand  and 
contract  by  alternations  of  temperature  as  it  ought 
to  do.  I  mean,  however^  very  soon  to  ascertain  -dus 
by  some  direct  and  decisive  experiments^ 

I  am  informed  by  a  Sheffield  manufacturer,  thfrt 
their  cast-steel  makers  mix  ground  coke  with  the 
best  Stourbridge  clay,  and  that  their  crucibles  lot 
melting  steel  are  made  with  this  mixture.  Puve 
earthenware  is  not  fit  for  crucibles,  or  for  any  vM- 
sels  that  must  expand  or  contract  by  change  of  ten> 
perature.  Tliis  has-been  long  known ;  Dryden  no- 
tices it  in  one  of  his  poems. 

It  is  said  that  in  France  the  very  best  crudbleb 
which  they  have,  are  made  with  fine  day  mixed 
up  with  old  ground  butter  pots ;  and  that  these  are 
composed  of  a  peculiar  kind  of  stone  ware,  which 
is  manufactured  in  Normandy  97. 

Where  crucibles  are  required  for  melting  metals, 
those  made  with  plumbago  are  decidedly  the  best ; 

but  these  are  unsuitable  for  other  purposes  of  the 

--  ^  -  —  ■■--  —  -  —  ^^ 

^'  See  the  article  Pottery  in  the  second  vol.  of  The  French 
Chemical  Dictiofwry, 


AND   PORCELAIN.  Ul 

laboratory,  especially  when  salts  and  alkaline  fluxes 
are  employed  in  any  process. 

InApaper  by  Vandermonde,  Monge,  and  BerCbbl- 
let  on  the  ^labufaGture.of  steel,  arid  which  was  pub« 
Ushed  by  order  of  the  Committee  of  Public  Safety  in 
Baris  in  the  second  year  of  the  republic,  they  say, 
^One  ci  the  ^eatest  difficulties  we  find  in  this 
cofmtiy  (France)  is  to  procure  good  crucibles  ^.^ 
The  art  of  pottery  in  a  manufacturing  country  like 
Great  Britain  is  in  all  its  parts  truly  important. 

More  than  eighty  years  ago  the  celebrated  Reau* 
mur,  in  making  some  trials  on  glass,  discovered, 
tiiat  if  a  vessel  made  of  the  common  green  boitle- 
gjass  be  submitted  to  the  heat  of  a  potter's  oven, 
imbedded  in  a  mixture  of  sand  and  ground  sulphate 
tflime,  the  glass  of  which  it  is  composed  will  be 
dumged  in  its  appearance,  and  acquire  some  of  the 
properties  of  the  best  Oriental  china ;  become  so 
hard  as  to  strike  fire  with  steel ;  be  semi-transpa- 
-ftiA  like  porcelain,  and  will  endure  sudden  changes 
of  temperature  without  breaking.  An  account  of 
these  results  was  given  in  the  Memoirs  of  the  Royal 
Academy  of  Sciences  for  the  year  1739  . 

Having  mentioned  this,  I  have  only  room  to  add, 
that  the  late  Dr.  Lewis,  who  conceived  highly  of 
this  discovery,  made  many  experiments  to  ascertain 
its  nature  and  importance,  the  particulars  of  which, 
together  with  several  most  judicious  remarks  upon 


^  An  abridgement  of  this  memoir  was  afterwards  published 
in  the  19th  vol.  of  the  Jnnales  de  Chiwne,  page  13 — 46. 


152  ON    EARTHENWARE 

them,  will  be  found  in  his  celebrated  work  on  the 
commerce  of  the  arts  9^. 

The  subject,  however,  appears  to  me  to  be  high- 
ly deserving  of  still  further  investigation,  especially 
as  useful  vessels  of  a  difficult  form  may  be  made 
more  easily  of  glass  than  of  earthenware.  If,  there* 
fore,  a  cheap  and  certain  method  of  fedoTvaing  tUs 
species  of  cementation  could  be  adopted,  the  ope^ 
rative  chemist  would  have  it  in  his  power  to  procuie 
a  greater  variety  of  chemical  vessels,  and  those  not 
only  more  durable  but  of  more  convenient  forms 
than  he  can  possibly  obtain  by  any  other  meana.  I 
wish  some  potter  would  commence  a  manufiBUStory 
of  this  kind.   Such  ware  would  be  highly  usefal  fior 
many  domestic  purposes,  to  which  none  of  the  com* 
mon  pottery  can  be  applied  either  with  conveoieooe 
or  safety. 

In  returning  to  the  subject  of  earthenware,  it  is 
proper  I  should  state  my  opinion,  that  chemical 
vessels  are  often  injured  by  the  oxide  of  iron  origi- 
nally pertaining  to  the  clay  itself,  asit  acts  like  aflux, 
rendering  this  earth  too  fusible  to  admit  of  a  proper 
union  with  the  siliceous  material  of  the  grouod 
pottery,  which  is  employed  in  the  manufacture  of 
such  articles.  A  question  arises  here,  whether  oapide 
of  iron  alone  is  prejudicial  in  this  way,  although 
its  sulphuret,  the  pyrites,  may.  It  may,  perhaps, 
be  worth  while  to  decide  this  by  experiment.  Mac- 
quer  says,  that  if  a  bit  of  pyrites  be  left  in  day 

*  Commercium  PhUoBophtco-Technicum,  p.  230 — 255^ 


AMD  PORCELAIN.  153 

which  18  to  be  exposed  to  a  baking  fire,  it  will  form^ 
a.caidty  in  the  ware,  and  that  this  maybe  known  hy 
the  ehrcumstance  of  the  cavity  being  stained  black. 

There  b  an  old  pamphlet  of  9  pages  in  the  Lon-' 
fkm  Institution/  without  title-page  or  date,  on  ma- 
Inng  porcelain,  in  which  the  writer  speaks  of  a  prac- 
fbee  tiie  Qiihese  have  of  purifying  the  earth  they 
ttoploy  for  the  glaze,  by  means  of  aqua-fortis.  On 
reading  this,  it  occurred  to  me,  that  it  might  perhaps 
be  worth  trying,  whether  this  expedient  could  be 
adopted  with  advantage  in  purifying  such  of  our 
di^  as  are  designed  for  the  finest  purposes. 

For  those  articles  in  which  the  chemical  nature 
of  the  body  of  the  ware  is  of  importance,  it  would 
fcrtiaps  be  advisable  always  to  wash  the  clay  tho- 
mogfaly ;  for,  if  pyrites  be  contained  in  it,  the 
greater  part  of  this  would  subside,  on  account  of 
its  superior  specific  gravity,  while  the  argillaceous 
earth  remained  suspended  by  the  water.  For  che- 
mical jars,  still-heads,  &c.,  a  small  portion  of  iron 
would  probably  not  be  injurious.  Vauquelin 
analysed  the  clay  of  which  Hessian  crucibles  are 
wmde,  and  found  it  to  consist  of  8  parts  oxide  of 
iron,  combined  which  69  of  silica,  22  alumina,  afid 
1  carbon. 

Clay  which  contains  lime  is  equally  improper  for 

.^  manufacture  of  chemical  vessels.     If  a  clay  be 

Mspected  to  contain  lime,   or  rather  carbonate  of 

lime,  it  may  readily  be  discovered  by  an  acid, 

wlucb,  if  this  earth   be  present,  will  occasion  an 


154  ON^  EARTHENWARS 

eflfervescenoe.    M^n  lime  does  not  exceed  fife  or 

six  per  cen  W  it  i4>peiar8  to  do  no  harm  to  t\ie  ^uali^ 
of  the  pottery ;  but  when  mpre  abundant,  it  cpm^ 
Huinicates  too  great  a  degree  of  fusibility :  in  Hce 
manner  l^ere  are  cases  in  which  an.  admixture  of 
the  oaddeof  iron  is  useful  and  even  oecessary. 

In  the  manufacture  of  what  is  called  DeUware  it 
has  been  customa.7  to  mix  .  portion  of  ferrugiooui^ 
clay  with  the  other  ingredients,  because  of  its  pos- 
sessing a  binding  quality  from  which  other  species 
are  exempt.  The  following  are  the  usual  pro|itfr-> 
tions :  Two  parts  of  red  clay,  three  of  blue  daji, 
and  five  of  marie  i^.  Most  of  the  red  clay  is  in- 
debted to  iron  for  the  colour  which  it  assumes; 
but  when  iron  enters  in  any  considerable  quantity 
into  the  composition  of  the  finer  kinds  of  :ear(heiit 
ware,  it  imparts  either  a  red  or  a  brown  tinge. to 
it ;  and  besides  this,  it  adds  more  fusibility  to  H 
than  even  lime. 

Recollecting  the  circumstance  just  menUoiie4 
respcicting  delfware,  it  .occurred  to  me,  in  reading 
one  of  the  volumes  of  the  ArcfuEohgiOf  that  a  ioqp- 
tain  iron-ore  found  in  Scotland  would  probably  h? 
useful,  when  mixed  in  a  small  proportion,  for  some 
articles  of  pottery.  I  will  give  an  abstract  of  ihfi 
passage  which  cai^ght  my  attention ;  and  if  any  in- 
genious manufacturer  should  be  able  to  avail  ^him- 
self of  this  hint,  and  convert  it  to  profit,  I  shall  be 

»  ■  '     '  -III 

^^  See  Macquer^8'C/^tcaII>te/toffafy/ article  Delfware. 


AND   PORCELAIN.  455 

iqmoed,  and  shall  at  any  time  be  glad  to  be  in- 
fimned  of  the  result,  and  the  respective  particulars 
which  attended  it. 

In  the  Highlands  of  Scotland  some  very  singular 
ftndent  walk  are  to  be  seen,  which  consist  of 
'^  stones  piled  rudely  upon  one  another,  and  firmly 
cemented  together  by  a  matter  which  has  been  vi- 
(rifled  by  means  of  fire,  and  which  forms  a  kind  of 
lotificial  rock  that  resists  the  vicissitude  of  the 
weather,  better  than  any  artificial  cement  that  ha^ 
ever  yet  been  discovered.** 

Mr.  James  Anderson,  the  person  who  has  writ- 
ten upon  these  curious  remains  of  antiquity,  has 
fMnd  that  through  all  the  northern  parts  of  Scot- 
land*  ia  peculiar  kind  of  iron  ore  of  ft  very  vitrescir 
Ue  nature  is  in  great  abundance.  Hence  he  aqp- 
|KiM8  that  ^*  when  the  walls  were  reared  and  made 
^as  firm  as  could  be  by  dry  stones  piled  one  iq|>on 
iiiother,  the  interstices  between  them  were  filled 
Ifhh  jthis  vitrescible  iron  ore,  and  the  whole  sup- 
ported by  a  backing  of  loose  stones  piled  behind  it. 
When  this  wall  was  thus  far  completed,  nothing 
more  was  necessary  to  give  it  the  entire  finishing, 
but  to  kindle  a  fire  all  round  it,  sufficiently  intense 
to  melt  the  vitrescible  ore,  and  thus  to  cement  the 
whole  into  one  coherent  mass>o^** 

Dr.  Lewis  has  related  a  remarkable  instance  of 


>°'  Jrchaologia,  vol.  v.  p.  255,  where  also  may  be  'seen  an 
account  of  a  fortification  of  this  kind  in  the  county  of  Ross, 
with  a. print  of  it,  accompanied  by  some  ingenious  obaervatioiis 
worthy  of  attention. 


156  ON    EARTHENWARE 

the  affinity  of  iron  for  silica.    Having  immersed 

some  pieces  of  green  glass  in  the  red  oxide  of  iron 

which  remains  after  the  acid  has  been  expelled  from 

green  copperas,  and  baked  it  for  severd  hours  in 

the  upper  chamber  of  a  wind  furnace,  the  glass  and 

oxide  of  iron  were  found  to  have  run  together  into 

a  black  mass,  of  sufficient- hardness  to  strike  fire 

freely  with  steel.     "  It  is  remarkable,**  says  he, 

^*  that  a  metallic  substance  so  refractory  in  the  fire» 

should  be  so  greatly  disposed  to  melt  with  green 
glass  w.*' 

Nothing  can  be  of  more  importance  to  a  potter 
than  a  thorough  knowledge  of  the  properties  of  the 
different  kinds  of  cla}^.  Dr.  Campbell,  in  his 
Political  Survey  of  Great  Britain,  states  that  w6 
have  not  less  than  twenty-two  distinct  species  i^; 
and  Macquer,  who  examined  more  than  eight  hun- 
dred specimens,  says  that  in  all  that  number  he  did 
not  find  one  that  was  entirely  free  from  metallic 
matter  »o*. 

There  is  only  one  method,  however,  by  which 
clajrs  can  be  examined  with  any  accuracy,  and  that 
is  by  the  aid  of  chemistry.  Such  of  my  readers  who 
are  potters  but  not  chemists,  will  therefore  allow 
me  to  advise  them  to  lose  no  time  in  acquiring  the 


'^  Commercium  PhilosopMcO'Technicum,  p.  245. 

>^  Campbeirs  L^olUical  Survey  of  Great  Britain,  vol.  Um]fA6. 
Morton's  Natural  HUtory  of  Northamptonshire,  p.  71. 

^  Macqiier*s  Memoir  upon  Clays,  presented  to  the  Frcndi 
Academy  in  1762^  and  abridged  in  the  Drench  Che$nical  Die* 
tUmary,  under  the  article  Clay. 


AMD  PORCELAIN.  15/ 

knowledge  of  analysing  eartha  and  minerals.  Am- 
ple directions  for  the  attainment  of  this  art  will  be 
found  in  Kirwan*s  Elements  of  Mineralogy  i05^  or  ta 
Klaproth*8  Analytical  Essays  ^^ ;  and  I  conceive  it 
impossible  that  any  manufacturer  will  ever  regret 
the  time  which  it  may  be  necessary  for  him  to  de- 
vote to  the  acquisition  of  that  elementary  knowledge 
which  would  enable  him  to  consult  these  distin- 
guished writers  with  pleasure  and  advantage  W. 

One  or  two  instances  of  the  mistakes  which  may 
occur  in  the  examination  of  mineral  substances, 
when  they  are  not  submitted  to  chemical  analysis^ 
will  be  sufficient  to  show  the  importance  of  this 
inquiry,  and  will,  I  hope,  induce  the  junior  practi- 
tioners at  least,  to  adopt  this  advice,  and  enter  upon 
that  course  of  study  which  will  be  most  likely  to 
sflford  profit  as  well  as  entertainment. 

The  precious  stones  were  formerly  classed  with 
uKceous  fossils ;  and  until  Bergman  and  Klaproth  ^^ 
aaudysed  several  of  them,  they  were  generally  sup- 
posed to  be  entirely  composed  of  silica  combined 
with  a  portion  of  colouring  matter,  to  which  they 
were  solely  indebted  for  their  distinctive  characters 
mnd  appearances.  An  accurate  analysis  of  several 
of  these  gems,  particularly  of  the  Sapphire,  the 


w*  Printed  in  2  vols,  8vp,  London,  1794. 

*^  Translated  from  the  German,  in  2  vols.  8vo,  London, 
1801. 

^  See  more  on  this  subject  in  vol.  i.  p.  21. 

^  See  Bergman's  Essay,  entitled  "  A  Dissertation  on  the 
BaHh  of  Gems,'*  in  his  Collection  of  Essays,  vol  ii.  pNige  76^^ 
121  ',  and  Kluproth's  jlnalytkal  Essays  before  mentioned. 


158  ON   EARTHENWARE 

Topnz,  the  Hyaciotb,  and  the  Ruby»  has,  however, 
proved  that  either  alumina^  or  adrcone,  and  not  si* 
Uca,  is  in  these  instances  the  predominant  ihgredB- 
ent;  The  Sapphire,  according  to  Klaprbth,  con* 
sists  of  clay  98*50,  oxide  of  iron  1,  Kme  0*50. 
The  Topaz  consists  of  clay  46,  silica  39,  lime  8, 
iron  6.  The  Hyacinth  of  zircone  70,  silica  25, 
oxide  of  iron  0-50,  loss  4-50.i<^  The  R«byii 
comp6sed  of  clay  40,  silica  39,  lineie  9,  and  iron 
10.110 

The  well-known  article  called  Fuller's  BarUi,from 
its  saponaceous  texture  had  been  supposed  to  con* 
sist  almost  entirety  of  clay  or  alumina ;  Imt^  on  iB 
accurate  analysis,  it  has  been  ascertained  thi^  dw 
earth  which  enters  into  its  composition  in  the 
largest  proportion  is  silica.  According  to  the  ansi* 
lysis  of  Bergman,  Fuller's  Earth  consists  of  sillbi 
5 1*8,  alumina  25,  lime  3*3,  magnesia  0*7,  iron'0'7, 
water  15*5.  Hence  it  may  be  accounted  for,  .why 
it  falls  into  a  powder  when  put  into  water,  and  il 
incapable  of  forming  a  ductile  paste.  On  the  coil* 
trary,  Emery,  which  had  very  much  the  appearibci 
of  sand  or  ground  silica,  is  for  the  most  part  argil- 
laceous earth  or  alumina,  and  the  siliceous  earth  Is 
in  k  Very  inconsiderable  quantityi^i. 

The  last  instance  which  I  shall  adduce  is  one 


>^  Klaproth*s  Analytical  Essays,  vol.  i.  page  198. 

>*<^  Bergman*s  Essays,  vol.ii.  p.  101. 

"*  Emerv  from  the  Isle  of  Naxos  is  composed  of  alumina  80, 
silica  3>  and  iron  4,  undissolved  3  parts.  Tennant*s  Analym, 
Phil.  TransJor  1802,  p.  401. 


AMD   PORCELAIN.  159 

that  is  intimately  connected  with  our  subject,  and 
i^bich  shows  decisively  how  necessary  it  is  for  a 
potter  to  be  capable  of  undertaking  a  chemical 


The  porceliain  earth  of  Baudifiero  was  pro- 
Doonced  by  Macquer  and  Baum^  to  be  a  clay  su- 
perior iti  quality  to  that  which  was  then  employed 
lA  the  manufactory  belonging  to  the  French  King 
at  Sevres ;  and  on  their  authority  this  was  general- 
ly believed,  till  Mr.  Giobert  discovered  that  not  a 
{lartide  of  clay  could  be  found  in  it^'^.  For,  when 
this  chemist  attempted  to  convert  it  into  alum,  he 
fahnd,  to  his  great  surprise,  nothing  but  very  pure 
drystals  of  Epsom  salt,'  or  sulphat  of  magnesia. 
Af^  this,  Giobert  analysed  this  mineral  with  great 
fikre;  and  found  it  to  consist  of  magnesia  68,  car- 
bonic acid  12,  silica  15*6,  sulphat  of  lime  1*0, 
and  water  3.113 

Since  that  period  niagnesian  earth  has  been  much 
emplojred  in  the  composition  of  porcelain,  it  having 
bem  ascertained  that  a  small  portion  of  it  prevents 
that  great  degree  of  contraction  which  always  takes 
plaoe  in  the  fire,  when  clay  and  silica  alone  are 
made  use  of.  The  Cornish  steatites  or  soap  rock 
being  a  mineral  containing  magnesia,  some  of  the 
Bnglish  potters  now  employ  it  for  this  purpose. 

I  have  understood,  that  in  England  the  Steatites 


'**  See  Murray's  Sysiem  of  Chemistry,  vol.  ii.  p.  253. 
**^  Nicholson's  Journal,  vol.  xii.  p.  277,  from  the  Journal  de 
Physique,  vol.  Ix. 


160  ON    EARTHENWARE 

was  first  used  by  the  porcelaia  manufacturers  at 
Worcester,  and  that  they  pud  at  the  rate  of  201; 
per  ton  for  it.  In  a  well-known  publication  it  has 
been  stated  that  much  of  the  land  is  in  possession 
of  the  great  Staffordshire  houses,  who  have  taken 
leases  of  it  for  the  purpose  of  possessing  themselves 
of  this  very  valuable  natural  production.  I  learnt^ 
however,  in  the  year  1615,  from  most  respectable 
authority,  that  Steatites  had  then  never  been  em^ 
ployed  by  the  Staffordshire  potters. 

The  Steatites  of  Cornwall  occurs  at  the  lAzard 
Point,  in  a  serpentine  mountain  which  it  cuts 
through  in  small  perpendicular  veins,  called  rake* 
veins.  The  finest  sort  is  white,  with  blueish  or  nd^ 
dish  spots,  resembling  marble.  The  best  analysis 
of  this  mineral  gives  silica  48,  magnesia  20*50^ 
alumina  14^  oxide  of  iron  1,  water  15*50,  loss  1.  ^^ 

It  might  perhaps  be  worth  while  for  the  glass- 
makers  to  try  the  effect  of  a  small  mixture  of  Stea* 
tites  with  the  materials  of  which  they  make  tbeii^ 
large  crucibles ;  because,  if  it  prevent  that  gteat 
degree  of  shrinking  to  which  they  are  now  liable, 
it  would  be  very  advantageous. 

I  have  been  informed  by  an  eminent  maker 
of  plate  glass,  that  their  crucibles,  which  are  at 
first  32  inches  deep,  will  not  measure  more  than 
29  inches  when  they  have  undergone  the  heat  of 
the  oven  and  become  thoroughly  baked ;  and  that 

■»♦  Klaproth*s  Analytical  Essays,  vol.  i.  p.  464. 


AND    PORCELAIN.  101 

Eis  conlractloii  lias  occasioned  very  great  loss, 
especially  in  respect  to  the  excise  duty. 

These  glass-house  pots  are  very  large  vessels, 
being  made  to  measure  nearly  as  much  in  diameter 
at  the  top,  as  in  depth,  consequently  the  shrinking 
on  the  whole  is  very  great ;  and  as  the  officer  of 
excise  gauges  them  before  they  are  burnt,  the  manu- 
facturer incurs  a  loss  of  duty  upon  as  much  glass 
as  might  be  contained  in  the  depth  of  3  inches,  and 
this  loss  recurs  every  time  such  crucible  is  charged  ; 
BO  that  a  manufacturer  who  pays  5000/.  per  annum 
in  duty,  must  pay  dOU/.  every  year  more  than  was 
contemplated  by  the  legislature. 

I  am  very  glad  however  to  have  it  in  my  power 
to  inform  my  readers,  that  since  this  was  written 
for  the  first  edition  of  this  work  the  hardship  there 
complained  of  is  entirely  removed,  the  Government 
having  made  an  alteration  in  the  mode  of  collect- 
ing the  duty  on  glass  ;  for,  instead  of  gauging  the 
crucibles,  the  duty  is  now  charged  on  the  finished 
glass  itself  according  to  its  actual  weight. 

Having  ventured  to  offer  these  observations,  I 
shall  conclude  with  a  few  hints  which  to  practical 
men  may  perhaps  be  useful. 

There  is  a  clay  found  in  the  territory  of  Sienna, 
in  the  province  of  Tuscany,  csMed  J'ossii  meai,  and 
by  Kirwan  Argillomurite,  which  is  capable  of  making 
hard  compact  bricks  that  will  float  in  water,  either 
baked  or  unbaked.  M.  Fabroni,  who  examined 
some  of  these  bricks  in  consequence  of  their  having 

VOL.  n.  M 


i 


162  ON   EARTHENWARE 

been  mentioned  by  Pliny  ^'^  sayi  that  they  may  be 
of  great  use  in  the  construction  of  reverberaUuy 
furnaces ;  for  they  are  such  bad  conductors  of  heat, 
that  although  one  of  such  bricks  should  be  made 
completely  red  hot  from  one  end  to  its  middle^  aay 
person  may  take  it  up  in  his  hand  by  the  other  end 
with  impunity  11^.  May  it  not  then  be  worth  while 
to  inquire,  whether  a  clay  possessed  of  similar  pib^ 
perties  cannot  be  found  in  Great  Britain  ? 

Moreover,  considering  the  improvements  wUch 
have  been  made  in  the  manufacture  of  potttiy^ 
might  it  not  be  easy  to  make  bricks  to  imitate  atOD^s^ 
and  yet  be  as  durable  as  the  bricks  now  in  use  ?  - 

By  means  of  Uie  metallic  oxides,  would  it  not  be 
posttble  at  a  cheap  rate  to  stain  bricks  of  any  iDO- 
lour^  and  might  not  such  bricks  be  made  to  inutale 
marble? 

In  the  Eissay  on  Barytes,  vol.  i.  page  3 17,  I  have 
stated^  that  Mr.  Wedgwood  employed  the  ml* 
phate  of  that  earth  in  the  manufacture  of  jasper; 
but  if  pure  barjrtes  itself  or  strontites  could  be  pcbr 
cured  without  much  expense,  might  not  these  also 
be  used  with  advantage  in  some  of  the  branchiia  cl 
pottery  ?  A  method  of  employing  sulphate  of  baiy» 
tes  in  pottery  is  indeed  alluded  to^  by  Sage,  in  one 
of  the  volumes  of  the  Journal  de  Physique.  **The 
Chinese,**  says  he,  <*  know  the  remarkable  property 
which  gum  adracanth  has  of  giving  a  coherence  ta 


"»  Sec  Pliny'8  Natural  HUtary,  lib.  xxxv.  cap.  14. 
»•  See  PhUa9ophkal  Magazine,  vol.  ii.  p.  180. 


.    AMD  EORCELAIN.       .  IAS 

minute  stony  substances,  which  are  then  unalterable 
hf  fire ;  and  that  if  this  gum  be  mixed  with  pounded 
salphate  of  barytes,  it  may  be  formed  into  masses 
iririA  nmther' alter  their  shape  nor  solidity  from' 
aqporaie-  to  an  iritiense  fire  *  >7.**  I  have  not  heard 
thsrt  any  English  potter  has  yet  availed  himself  of 
this  suggtistiom 

'^The  snfphates  of  barytes  and  strontites  may  be 
had  cheap  aiid  in  abundance ;  and  all  that  would 
be  necessary  is  to  roast  them  in  a  reverberatory  fur- 
umi  with  some  combustible  matter,  to  convert  them 
iillQ^  iaiphurets,  and  then  the  remaining  ffulphur, 
sboold  it  prove  injurious,  could  be  separated  by  a 
sriMM|oent  process  ^i^.  In  this  way  an  ingenious 
loaovfeeturer  might  probably  gain  unexpected  prb- 
fili^'fand  improvements  from  one  or  both  of  these 
eiitha; 

In  concluding  this  Essay,  I  trust  I  shall  stand  ex- 
cused, if  I  endeavour  to  confirm  an  opinion  already 
pven,  that  a  potter  should  never  employ  a  new 
pofodun-clay  without  previous  analysis  ;  for  there 
are  few  of  these  clays  that  can  be  employed  with 
the  certainty  of  a  good  result,  unless  some  fusible 
material  be  used  with  them  ;  and  the  quantity  of 
this  can  only  be  known  by  a  chemical  examination 
of  the  clay  in  question.  The  necessity  of  analysis 
will  appear  from  the  comparison  of  the  chemical 

"^  See  the  Retrospect  of  Philoiophical  Discoveries,  vol.  i. 
p.  50. 

***  Ad  account  of  a  process  by  which  this  might  be  efiected 
nay  be  seen  in  Essay  V.  vol.  i.  p.  861. 

m2 


164    ON  EARTHENWARE  AND  PORCELAIN. 

nature  of  three  of  these  native  productions.  The 
porcelain  earth  of  Limoges,  and  which  is  often  met 
without  any  admixture,  is,  according  to  Hassettfirati, 
composed  of.  62  parts  silica,  19  alumina,  12  mag- 
nesia, and  7  sulphate  of  barytes ;  whereas  the  poree- 
lain-clay  of  Cornwall  is  a  compound  of  20  per  cenL 
of  silica  and  60  per  cent  of  alumina ;  while  that 
found  in  the  department  of  the  Loire  in  France^  of 
a  beautifully  white  colour,  consists  entirely  of  car- 
bonate of  magnesia  and  silica. 

The  business  of  a  potter  affords  so  large  a  fidd 
for  the  exercise  of  taste  and  genius,  and  the  art  it- 
self is  so  intimately  connected  with  chemical  k&o#- 
ledge  and  experience,  that  it  would  be  superfloolas 
to  urge,  by  further  arguments,  the  absolute  nteet- 
sity  of  cultivating  the  science  of  chemistry,  in  onle^ 
to  arrive  at  perfection  in  any  branch  of  the  aaana- 
facture. 


ESSAY   XI. 


ON 


THE   MANUFACTURE 


OP 


GLASS. 


ESSAY    XI. 


ON 


THE  MANUFACTURE  OF  GLASS. 


Among  the  various  productions  of  art,  there  is, 
perhaps,  no  one  so  truly  surprising,  when  we  con- 
sider the  materials  from  which  it  is  formed,  as  that 
of  glass.  It  is  the  only  instance  that  I  recollect  of  a 
lubatance  perfectly  transparent  being  produced  by  the 
union  of  two  dissimilar  and  entirely  opake  bodies*. 
Many  of  the  ancients  who  wrote  on  Glass  seem 
however  to  have  known  nothing  of  its  real  nature. 
Agricola,  lib.  xii.  **  de  Metallis^  calls  it  a  concrete 
juice ;  Vincent  Belluascensis,  lib.  xi.  calls  it  as  tone ; 
tod  Fallopius  classes  it  with  the  middle  minerals. 

Different  opinions  have  been  held  respecting  the 
etymology  of  the  word  glass.  Some  have  derived 
the  term  from  its  resemblance  to  ice  {glac%es)% 
while  others  suppose  it  to  be  derived  from  glastumy 
the  English  woad,  a  vegetable  which  is  employed  in 
dyeing  bluCy  glass  having  generally  a  tinge  of  blue 
in  its  appearance  i. 

"  Sec  "  r^  Art  of  Glass;'  by  H.  Blancourt,  8vo,  London, 
1699,  p.  6.  both  text  and  note. 


16S  ON  THE  MANUFACTURE  OF  GLASS. 

The  date  of  this  elegant  and  useful  invention  is 
involved  in  great  obscurity  s.  According  to  Pliny, 
the  first  vessels  of  glass  were  made  in  the  dty  of  Si- 
don  9 ;  but  Loysel  asserts  that  the  glass  works  of 
the  Phoenicians  were  in  high  renown  more  than 
three  thousand  years  ago,  and  that  they  had  merely 
depdts  for  the  sale  of  their  glass  at  Sidon  and  a| 
Tyre  ^.  The  Egyptians  also  lay  claim  to  having 
first  made  it,  and  say  that  they  were  instructed  in 
the  art  by  the  great  Hermes  ^. 

Flavins  Vopiscus,  who  wrote  the  lives  of  Tadtus 
and  others,  in  the  rdgn  of  Dioclesian,  observes,* 
when  speaking  of  Alexandria,  that  "it  was  very* 
rich,  abounding  in  corn  ;  and  that  no  one  in  the- 
dty  was  idle,  for  that  one  part  of  the  poorer  inhft** 
bitants  were  employed  in  the  manufacture  of  paper, 
and  the  other  in  making  glass  J"    A  late  travdler 
who  explored  the  interior  of  Egypt,  has  also  as- 
sured  us  that  the  ancient  inhabitants  of  that  coun- 
try made  glass  6. 

Pliny  attributes  the  invention  of  glass  entirely  to 
chance,  and  relates,  that  it  was  first  made  in  Syrifr 
by  some  mariners  who  were  driven  on  shore  on  the 
banks  of  the  river  Bel  us ;  and  who,  having  occasion 


*  See  Dr.  Menrit's  Preface  to  his  Translation  of  Neri's  Art  of 
G/otf,  London,  12mo^  1662,  and  the  Introduction  to  Bias- 
court's  work  above  mentioned. 

*  Pliny,  lib.  xxxvi.  cap.  26. 

*  Essai  sur  VArt  de  la  Verterie,  par  le  C.  Loysel,  8vo,  Pkris, 
an  viii.  Discours  Pr^lhninaire,  p.  I . 

*  Blancourt's  Art  of  Glass,  p.  9. 

^  Be]zoni*8  Researches  in  Egypt,  S^c.  quarto^  page  1 73. 


OH  THB  MANUFACTURE  OF  GLASS.  189 

to  make  large  fires  on  the  sands,  burnt  the  kali 
wluch  abounded  on  that  shore ;  and  that  the  alkali 
of  the  plant  uniting  with  a  portion  of  the  sand  on 
which  the  fire  stood,  produced  the  first  stream  of 
melted  glass  that  had  ever  been  observed  7. 

However  this  may  be,  there  can  be  no  doubt  of 
glass  having  been  in  use  during  the  time  of  Pliny, 
as  it  is  often  mentioned  not  only  by  him,  but  by 
many  contemporary  authors.  The  city  of  Hercu- 
laneum,  which  was  destroyed  about  this  period  by 
an  eruption  of  Vesuvius,  contained  glass.  Besides 
utensils  of  glass,  a  large  sized  plate  of  the  same 
OMDpound  was  taken  from  one  of  the  excavations. 
Josephus  relates,  that  not  far  from  Mount  Carmel 
there  is  a  round  valley  full  of  a  clear  sand  fit  for 
making  glass ;  and  that  when  the  place  has  been 
onptied  for  this  purpose,  the  wind  from  the  moun- 
tains fills  it  again  immediately^.  But  this  historian 
could  have  known  nothing  of  the  nature  of  the  ma- 
nufacture of  glass ;  for  he  asserts,  that  any  metal 
when  thrown  upon  this  sand  will  be  instantly  con- 
verted into  glass,  and  that,  if  glass  be  cast  upon  it, 
the  glass  itself  will  likewise  be  changed  into  sand9. 

Tacitus  mentions  the  river  Belus,  but  he  speaks 
more  rationally  of  the  glass  which  was  made  in  that 
neighbourhood  than  Josephus.  He  says,  that  this 
fiver  flows  into  the  sea  of  Judea,  at  the  mouth 
whereof,  the  sand  that  is  taken  up,  in  consequence 


^  Pliny,  lib.  v.  cap.  19. 

•  History  of  the  fVars  of  the  Jews,  book  ii.  chap.  9. 

*  Ibid,  book  ii.  chap.  1 7. 


)70  ON  THE  MANCTFACTCRE  t>r  GUkSB. 

of  the  great  quandt^  of  nitre  contained  in  it,  is  by 
the  heat  of  a  furnace  readily  converted  into  ^ait ; 
and  that  although  the  shore  be  amall,  the  aand  is 
inexhaustible  10. 

The  time  when  glass  was  discovered  is  unknoiwn. 
Herodotus  and  Diodorus  Sicujus  rdate  that  the 
Ethiopians  formerly  inclosed  their  dead  bodies  in 
glass,  and  that  the  ancient  Egyptians  made  glass  of 
a  dark  colour  in  imitation  of  that  manufiactured  in 
Ethiopia.  But  their  magnificent  cups  ennce  m 
considerable  knowledge  in  the  art  of  making  glass;* 
and  of  which  the  Emperor  Ebdrian,  then  residing  at 
Alexandria,  thus  writes  to  the  consul  Servius :  **  I 
have  sent  to  you,**  says  he,  "  some  Alassian  cups  ot 
various  colours,  given  to  me  by  the  priest  of  the 
temple.  They  are  dedicated  to  you,  and  partica- 
larly  to  my  sister ;  and  I  desire  that  you  will  always 
produce  them  at  your  feasts  on  holidays  i^** 

Several  ancient  writers  relate,  that,  in  the  rdgn 
of  Tiberius,  an  eminent  Roman  architect  acqiured 
great  celebrity  from  the  manner  in  which  he  bad 
repaired  a  large  portico  in  the  city,  which  was  gi^ng 
way  and  seemed  likely  to  fiall ;  and  that  on  account 
of  his  popularity,  or  some  other  such  cause,  the 
emperor  banished  him  from  Rome,  forbidding  him 
ever  to  return  again.  This  individual,  it  is  further 
stated,  when  in  banishment,  made  experiments  on 
glass,  and,  having  discovered  a  mode  of  rendering 


10  Blanc(mri*8  Art  of  Glass,  p.  14. 

11  Bergman's  Physical  Essays,  vol.  iii.  page  33. 


OK  TRE  MANUFACTURE  OF  CLASS.  T^l 

it  malleable,  ventured  again  to  Rome  and  found 
means  of  presenting  one  of  bis  glasses  to  Hberius, 
ia  the  bape  of  not  only  being  pardoned  for  return- 
ing witbout  leave,  but  baving  his  sentence -altoge* 
ther  remitted ;  and  tbat^  on  the  contrary,,  the  em? 
peror  was  displeased  at  the  invention,  supposing 
that  it  would  tend  to  lower  the  value  of  gold  ;  and 
having  learned  from  him  that  no  one  was  acquainted 
with  the  method  but  himself,  he  ordered  his  head 
to  be  immediately  struck  off,  that  the  dangerous 
secret  might  not  transpire  >^.  Pliny  relates,  that  an 
artist  who  had  acquired  the  art  of  making  mallea- 
ble i^ss^  had  his  house  destroyed  by  the  enraged 
populace. 

i'  Blancourt  asserts,  that  an  ingenious  Frenchman, 
ui  the  reign  of  Lewis  the  Just,  also  discovered  the 
art  of  making  malleable  glass,  and  that  he  present- 
ed a  fine  image  or  bust,  made  with  such  glass,  to 
the  Cardinal  Richlieu ;  who,  foreseeing  the  injury 
which  such  an  invention  would  do  to  the  glass  ma- 
aubcture,  ordered  the  artist  into  perpetual  impri- 
sonment 13. 

We  read  of  glass-houses  being  in  use  sery  early 
in  the  city  of  Tyre :  and  there  is  reason  to  believe 
that  great  part  of  the  known  world  was  at  one  time 
supplied  with  glass  by  the  Tynans,  though  it  ap- 
pears uncertain  whether  the  great  manufactories 
were  in  their  city  or  in  Phoenicia,  as  before  men- 
tioned.    It  has  also  been  said,  that  glass-houses 

-    **  Dion  Cassius^  Hist.  Rom.,  Isidorus,  and  Petroniun  Arbiter. 
"  Blancourt '»  Art  of  Glas$,  p.  15. 


]7t  OM  THE  MANUFACTURE  OF  GLASS. 

were  erected  in  Great  Britain  before  it  vms  visited 
by  the  Romans. 

It  is  very  uncertain  wheti  glass  was  first  employ- 
ed for  the  transmission  of  light  and  other  optiod 
purposes,  or  how  long  any  of  the  nations  of  Bu* 
rope  have  enjoyed  the  benefit  of  glass  windows.  -  I 
think  I  have  read  that  the  best  buildings  in  Her- 
culaneum  had  windows  made  with  a  sort  of  trans- 
parent talc  ^1 

One  of  our  oldest  English  historians,  Bede,  tells 
us  that  in  the  seventh  century  it  was  not  known 
how  to  make  window  glass  in  England ;  and  that 
in  the  year  674,  the  Abbot  Benedict  sent  for  arttsls 
from  abroad  to  glaze  the  church  and  monastery  ojF 
Weremouth  in  the  county  of  Durham.  These 
men  came  probably  from  Venice;  for  the  first  ghM 
that  was  manufactured  in  Europe  was  made  there. 
Loysel  thinks  that  the  emigration  of  refugee  artists 
of  Phoenicia  to  Italy  brought  the  glass  trade  first 
among  them>^.  We  learn  also  from  Bede  that  the 
agents  of  the  Abbot  *'  brought  several  glass-makers 
with  them  when  they  returned,  who  not  only  per- 
formed the  work  required  by  Benedict,  but  in« 
structed  the  English  in  the  art  of  making  window 
glass  for  themselves,  also  glass  for  lamps,  drinking- 
vessels,  and  other  uses  i^.** 

Notwithstanding  the  interest  which  so  important 

'^  Seean  Account  of  the  Antiquities  of  Herculaneum  translated 
from  the  Italian  by  Messrs.  Martyn  and  Lettice^  in  quarto,  with 
engravings. 

'^  Euai  sur  tArt  dt  la  Verrerie,  Discours  PrAmiuaire,  p.  3. 

^*^  See  Bede*6  History  of  fVeremouth. 


ON  THE  MANUFACTURB  OF  GLASS.  173 

an  application  of  glass  was  likely  to  occasion,  it  is 
probable  that  glazed  windows  were  not  common  in 
these  kingdoms  until  several  centuries  after  thte 
period  above  mentioned.  Dr.  Henry  says  positive- 
ly, that  although  the  art  of  making  glass  was  in- 
troduced in  the  seventh  century,  it  was  afterwards 
so  much  neglected,  that  no  private  house  had  glass 
windows  till  after  the  conclusion  of  the  tenth  cen- 
tury ^7.  Before  that  period  the  windows  of  houses 
and  even  of  cathedral  churches  admitted  the  light 
through  fine  linen  cloths  or  lattices  of  wood  ^K 

To  prevent  the  surprise  that  may  be  occasioned 
to  some  persons,  by  the  assertion  that  glass  win- 
dows are  comparatively  but  of  late  introduction  in 
Europe,  it  may  be  remarked,  that  there  are  some 
countries  on  the  face  of  the  globe  which  have  never 
yet  enjoyed  this  luxury.  This  is  the  case  at  pre- 
sent at  Rio-de- Janeiro  in  South  America;  for  a 
friend  of  mine,  who  is  largely  concerned  in  the  ma- 
nu&cture  of  glass,  sent  a  considerable  quantity  of 
window  glass  cut  into  panes  of  different  sizes,  to  that 
country,  when  the  court  of  Portugal  removed  thi- 
ther, in  expectation  of  making  a  great  advantage  of 
it :  but,  when  it  arrived,  the  captain  of  the  vessel 
had  the  mortification  of  learning  that  there  were  no 
window-frames  in  any  of  their  houses,  and  conse- 
quently the  glass  would  be  useless.  The  glass  was 
dierefore  sold  for  embellishing  the  images  of  the 


»^  Henry's  History  of  Great  BrUain,  8vo,  vol.  iv.  p.  118. 
»■  William  of  Malmsbury  De  GesttM  Pontifie,  p.  149. 


1 74  OK  TH£  M  AN  U  PACTU  RE  W  OLASft. 

saints,  it  being  customary  to  decorate  the  walls  of 
every  house  with  such  images  and  statues  with  glass 
before  them,  something  in  the  way  in  whidi  stuffisd 
birds  are  preserved  in*  this  country. 

It  would  seem  that  glass  had  not  been  long  ia 
common  use  for  windows,  or  for  the  mere  trims* 
mission  of  light,  before  the  Monks  became  desirous 
of  decorating  it  with' ornamental  paintings;  -for  the 
art  of  painting  on  glass  Was  brought  into^  this  eoiiiit. 
try  in  the  early  part  of  the  thirteenth  centtuy, 
during  the  reign  of  King  John^t^;  it  having  beat 
)>ractised  in  France  some  time  before  that  peribd, 
and  must  then  have  arrived  at  a  considerable  degree 
of  perfection,  for  it  appears  that  the  windows  ih 
the  Abbey  of  St.  Denys  were  painted  in  the  tweM)dl 
century.  The  subjects  of  these  paintings  were  tlM 
representation  of  tlie  first  Croisade,  in  ten  diffierenfc 
compartments,  of  which  the  engravings  may  be  sees 
in  Mont&ueon  ^.  ■     •* 

So  late  as  iii  the  thirteenth  and  fourteenth  cen* 
turies,  the  houses  of  the  lower  cliasses  in  En^aftd 
had  not  glass  windows.  Nor  is  it  improbable  that 
such  windows  were  thought  very  magnificent  even  m 
iehurehes ;  for  Chaucer,  who  wrote  towards  the  htter 
end  of  this  period,  in  describing  the  dress  of  his  pa^ 
rish  clerk  Absalom,  says  that  the  upper  parts  of  his 
shoes  were  cut  in  imitation  of  the  church  window  *k 


»•  Walpole*8  Anecdote*  of  Pamting,  p.  5. 
^  Montfaucon^  Les  Monuments  de  la  Monarclue  Franfoue, 
folio,  Paris  1729,  tome  i.  p.  384. 
•»  Chaucer's  fVorks,  p.  26. 


OM  TUB  MANUFACTURE  OF  GLASS.  1 76 

It  is  generally  understood,  that  the  houses  in  Italy 
were  the  first  in  Europe ,  that  were  decorated  with 
glass  windows;  that  the  custom  was  klopted  iik 
France  soon  afterwards  i  and  that  the  French  na^ 
tion  enjoyed  that  luxury  a  considerable  time  before 
England  availed  herself  of  the  improvement. 

Even  now,  in  some  of  the  least  civilized  parts  of 
the  Russian  Empire,  a  kind  of  laminated  gypsum 
ealkd  ta^ns  speculariSy  found  in  abundance  in  that 
country,  is  used  in  windows  as  a  substitute  for  glass; 

Coloured  glass,  or  glass  stained  during  its  manii^ 
bctnre,  was  known  to  the  ancient  Greeks  and  Ro» 
mails ;  but  it  is  only  of  late  years  that  the  English 
ardsts  have  acquired  a  knowledge  of  this  process. 
Dogdale  informs  us»  that  when  the  citizens  of  LoU'^ 
dkm  in  the  reign  of  Henry  V.  undertook  to  beautify 
Si.  FauFs,  one  John  Prudde,  a  glazier  in  Westmin* 
Iter,  engaged  to  glaze  the  chapel  ^  with  glass  from 
beyond  the  seas,  of  the  finest  colours,  of  blue,  yd- 
low,  red,  purpure,  sanguine,  and  violet,  and  of  all 
oiher  colours  that  shall  be  best  to  embellish  the 
matters,  images  and  stories  that  shall  be  delivered 
toi  him,  by  patterns  on  paper,  in  rich  colour,  at  his 
idiarges  ».** 

From  this  testimony  it  appears  that  glass  in  con- 
siderable quantities  was  made  on  the  continent  of 
Europe  earlier  than  in  this  country.  In  Bohemia 
glass  is  now  made  to  a  very  great  extent.  There 
are  even  many  towns  that  are  dependent  upon  this 

*"  Dogdale'ii  Ant\quiHe»  of  Warwkkihire,  vol.  i.  p.  446. 


1 76     OK  TH  E  M ANU  FACTU  RE  OF  GLASS . 

manufactory,  and  the  continent  is  chiefly  supplied 
by  tliese  artists.  Their  practice  is  to  fix  upon  a 
lai^  wood,  and  cut  down  timber  enough  to  allow 
them  room  to  build.  With  this  timber  they  erect 
a  wooden  house,  together  with  sheds  and  ware* 
houses  ;  they  then  dig  for  clay  to  make  the  furdace : 
when  this  is  ready  they  cut  down  timber  for  fuel, 
and  from  the  ashes  of  the  fuel  and  those  of  the 
brush-wood  they  prepare  the  alkali  for  th^  use  of 
the  manufactory.  When  the  wood  is  cleared^  and 
their  fuel  exhausted,  these  buildings  are  pulled  down, 
and  the  workmen  remove  to  another  district. 

The  Government  of  France,  in  the  early  part  ci 
the  fourteenth  century,  took  great  pains  to  improve 
the  manu&cture  of  glass,  and  ordained  that  none  but 
gentlemen  or  the  sons  of  the  nobility  should  be  al- 
lowed to  exercise  the  trade,  or  even  to  work  as  arti^ 
ficers  in  the  manuftictories  of  this  most  highly  es- 
teemed commodity  ^.  In  consequence  of  this  in« 
junction,  a  company  of  persons  of  this  description 
was  incorporated,  and  obtained  many  important 
privileges  and  immunities  from  the  state,  particu- 
larly that  of  being  allowed  to  work  at  this  curious 
art  without  derogating  from  their  nobility.  It  is 
indeed  asserted,  by  the  writer  who  is  the  best  au- 
thority  we  have  on  this  subject,  that  there  never  was 
an  instance  of  anyone  being  attainted  to  whom  these 
privilege^  had  been  granted ;  for  they  conducted 
themselves  so  irreproachably,  that  their  honours 

«  Blancourt's  Art  of  Glass,  p.  24. 


ON  THK  MANUFACTURE  OF  GLASS.  177 

were  invariably  transmitted  inviolate  to  their  poste- 
rity**- 

It  was,  probably,  the  success  of  the  Venetians  in 
tbia  elegant  art  which  induced  the  French  authori- 
ties to  interest  themselves  in.  promoting  its  esta- 
Uitjiment ;  for  it  appears  that,  in  the  thirteenth 
oentory,  these  people  had  established  a  manufactory 
of  large  glass  mirrors  at  Murano,  a  populous  vil- 
lage within  one  mile  of  Venice,  where  mirrors  of 
sodi  an  uncommon  size  were  made  that  they  asto;- 
niabed  all  Europe  s^.  Henry  III.  King  of  France, 
when  visiting  Venice,  was  so  charmed  with  the 
IPQfk  of  the  artificers  at  Murano,  that  he  ennobled 
both  them  and  their  posterity  ^. 

In  the  year  1453,  Anthony  de  Brossard,  Lord  of 
Sl  Martin  and  Prince  of  the  blood  royal,  finding 
the  business  of  glass-making  to  be  so  considerable, 
and  knowing  that  it  did  not  derogate  from  nobility, 
obtained  a  grant  from  the  Prince  to  establish  a  glass- 
house in  his  own  county,  with  prohibition  of  any 
other ;  and,  in  consequence  of  this,  the  elder  sons.of 
dijit  family  continued  uninterruptedly  to  exercise 
the  art  till  the  latter  end  of  the  sixteenth  century, 
when  the  proprietor  was  killed  while  commanding 
a  troop  at  the  siege  of  Chartres.  Some  time  before 
tUa  period,  the  Messieurs  de  Caqueray,  gentlemen 

of  ancient  extraction,  procured  the  right  of  glass- 

— ^^—i ^■~—  ■        ■  ■       ■  ■■ 

••  Blancourt'8  Art  of  Glass,  p.  28. 

^  Bi»ching*8  Geography,  vol.  iii.  p.  83.  Misson^s  Voyage  to 
It^,  vol.  i.  part  i.  p.  300. 

*"  Bi]8ching*8  Geography,  vol.  iii.  p.  83.  Mis8on*8  Voyage  to 
ItoJJif^Tol.  i.p.301. 

VOL.  II.  N 


178  ON  THE  MANUFACTURE  OF  GLASS. 

making  by  an  alliance  in  marriage  which  one  of 
their  ancestors  in  the  year  1468  contracted  virith  s 
daughter  of  the  Lord  of  St.  Martin  above  mentioned, 
who  gave  up  half  of  his  right  to  the  monopoly  of 
glass  for  part  of  her  marriage  portion.  This  grimt 
was  afterwards  confirmed  in  the  Chamber  of  Ac- 
counts of  the  French  Government  *7. 

On  the  death  of  Anthony  de  Brossard,  the  younger 
sons  of  his  family  undertook  to  carry  on  the  art, 
and  continued  it  for  more  than  a  century.  Whedwr 
the  trade  continues  still  in  the  same  line,  I  have  not 
hitherto  been  able  to  ascertain. 

An  ancient  family  of  the  name  of  Vaillani  also 
obtained  the  grant  of  a  glass-house  as  a  recompenafc 
for  their  valour  and  public  services,  together  witb  a 
poignard  d*or,  on  azure,  for  their  arms^.  Mr. 
Blancourt,  who  long  resided  in  France,  likewise  IHH 
tices  that,  at  the  time  he  wrote,  they  had  many  other 
great  families  among  them,  who  were  dei>oena^ 
from  gentlemen  glass-makers  that  had  dedined 
following  the  art,  and  that  some  of  these  had  been 
honoured  with  purple,  and  with  the  highest  AvgA- 
ties  and  offices  in  the  state. 

Here  it  may  be  observed  that  the  art  of  grinding 
land  cutting  glass  for  ornamental  purposes  was  nctt 
practised  till  about  the  beginning  of  the  1 7th  ceh^ 
tury.  The  inventor  is  said  to  have  been  Caspar 
Lehmann,  who  obtained  in  the  year  1609,  from  the 
Emperor  Rodolphus  II.,  the  title  of  ^*  Glass-cutter 

*'  Blancourt*8  Art  of  Glass,  p.  30.  «•  J6id.  p.  30. 


ON  THE  MANUFACTURE  OF  GLASS.  1/9 

to  the  Court  «9."  The  art  of  engraving  on  glass  by 
fluoric  acid  was  introduced  by  Henry  Swanhard,  an 
artist  of  Nuremberg,  in  the  year  1 670.  ^ 
'  The^lass  made  in  France  had  never  been  equal 
to  that  fabricated  in  Italy.  But,  while  the  great 
Colbert  ^^  was  Minister  of  that  country,  a  fortunate 
eveiift  enabled  that  eminent  man  to  lay  the  founda- 
tion of  this  manufactory  in  the  way  which  they  had 
so  long  desired. 

CirtBxn  French  artists,  established  at  Venice, 
found  means  to  obtain  at  Miirano  an  exact  know- 
hdga  of  the  processes  employed  in  the  fabrication 
^  I^bte  glass,  and  they  returned  to  France  with  th^ 
hope  of  enriching  their  native  land  with  that  splendid 
btanch  of  art  and  of  commerce.  The  Minister  re- 
eehied  them  graciously ;  and,  having  empowered 
titnetn  to  select  such  a  situation  as  they  might  deeni 
theb^  suited  to  their  undertakhig,  they  established 
tttdnselves  in  the  year  1665  at  Tourlaville,  neat 
OberbOurg  s^.  This  Company  afterwards  obtained 
l^^^ikteiitfor  making  plate  glass,  and  an  advance  of 
IS^CKX)  livres  for  four  years  was  grafited  them  b^ 
tte  FVen^ch  Government. 

'  ■  In  the  year  1688,  Abram  Thevart,  an  ingenious 
ifainnfiacturer,  made  a  proposal  to  the  Court  for 
wHmg  glass  mirrors,  and  engaged  that  they  should 

*  Beckmann,  vol.  iii.p.  223. 

*  NichoIson*8  4to  Journal,  vol.  iv.  p.  1 . 

>>  Something  more  respecting  this  extraordinary  man  will 
be  found  in  vol.  i.  pp.  180  and  195. 
^  Loysel  Ditcours  Pr^Uminaire,  pp.  5  and  6. 

n2 


180  ON  THE  MANUFACTURE  OF  GLA88. 

be  of  a  larger  size  than  any  ever  before  made^. 
This  individual  obtained  likewise  a  patent  to  con- 
tinue for  thirty  years ;  and  the  first  plates  which  be 
cast34  were  made  at  Paris,  and  were  of  the  extrtcv- 
dinary  dimensions  of  84  inches  by  50  inches,  a 
size  which  surprised  all  the  artists  of  that  day  ^. 

Notwithstanding  this  success,  not  more  than 
three  years  elapsed  before  these  proprietors  fonnd 
it  expedient  to  remove  their  establishment  to  St. 
Gobin,  in  the  department  of  the  Aisne  ^,  and  there 
they  laid  the  foundation  of  a  manufactory  which 
is  still  in  a  flourishing  condition,  and  is  perhaps 
the  most  important  one  of  the  kind  which  is  yet  in 
enstence. 

In  these  stupendous  works,  plates  for  mirrors  aie 

now  made  of  the  vast  size  of   105  inches  in  height 

by  60  inches  in  breadth  ;  and  when  they  have  been 

properly  annealed  they  are  conveyed  to  the  Gobelips 

in  Paris  to  be  polished  ^.    The  double  convex  lens 

which  I  have  described  in  the  Essay  on  Temperatii^y 

vol.  i.  page  86,  was  made  in  the  same  mani^K^ 

tory.     The  instrument  described  above  has  be^ 

broken,  and  the  Government  have  since  caused  to 
be  fabricated  at  the  same  manufactory  a  massive 

plate  of  2  metres  diameter  by  0*067  in  thiekneM» 

weighing  500  kilogrammes;  the  largest  piece  of 

'^  Mirrors  of  glass  were  attempted  to  be  made  in  the  andent 
glass-houses  of  Sidon ;  but  the  artists  could  not  succeed  in  the 
attempt.     Pliny,  lib.  xyxvi.  cap.  26. 

^  A  very  interesting  and  instructive  paper  on  the  antiqidty  d 
metallic  mirrors  may  be  read  in  Beckmann*s  History  of  Imfm' 
tions,  vol.  iii.  p.  J64. 


ON  THE  MANUFACTURE  OF  Gl^S^S.  181 

workmanship  in  glass  that  was  ever  executed,  being 
in  English  measure  2^  inches  thick,  6  feet  6  inches 
in  diameter,  and  weighing  eleven  hundred  pounds 
avoirdupois. 

It  18  now  time^  however,  for  us  to  look  into  the 
progress  of  this  manufacture  in  England.  The 
method  of  working  in  glass,  as  we  have  already 
seen,  was  introduced  here  so  early  as  the  seventh 
century  ;  but  I  am  inclined  to  think  that  for  many 
ages  our  artificers  made  no  improvement  whatever 
in  this  curious  art.  Their  business  was  probably 
confined  to  the  manufacture  of  coarse  window  glass, 
and  the  most  rude  kind  of  culinary  and  drinking 
vessels. 

Nevertheless,  about  the  middle  of  the  sixteenth 
century  this  country  began  to  acquire  eminence  in 
the  manufacture  of  glass,  of  which  we  have  abundant 
evidence :  thus  in  the  year  1575  one  of  the  London 
glass-houses  was  destroyed  by  fire ;  and  Holinshed, 
speaking  of  it,  says,  "The  same  house  which  had 
consumed  great  quantities  of  wood  in  making  fine 
irinkmg'glasses  is  now  itself  consumed  38.** 

Manufactories  of  considerable  consequence  were 
afterwards  established  at  Crutched  Friars,  and  in 
the  Strand,  London  ;  and  these  were  much  encou- 


^  Savary  Dici.  de  Commerce,  tome  iii.  p.  87.  Beckmaniij 
voLiii.p.  216. 
^  Loysel  Discours  PrHminaire,  p.  7. 
*^  BuBching's  Geography ,  vol.  ii.  p.  398. 
"  Holinshed's  Chronicle,  p.  1261. 


182  ON  THE  MANUFACTURE  OF  GLASS. 

raged  bjr  King  James  .1.  and  Charles  I.»  who  both 
prohibited  the  importation  of  all  foreign  glasa^  ex- 
cepting that  of  the  most  inferior  kinds  ^. 

The  former  of  these  monarchs,  as  an  expedient 
to  raise  money  without  the  aid  of  Parliament,  grant- 
ed to  Sir  Robert  Mansel  an  exclusive  patent  for 
making  glass,  and  allowed  it  to  be  given  out,  that 
tbb  monopoly  was  afforded  him  in  consideration  of» 
and  as  a  reward  for»  his  having  substituted  pit  cod 
for  wood  in  its  manufacture ;  and  that  on  the  same 
ground  he  should  be  allowed  the  exclusive  privilege 
of  importing  drinking- vessels  and  every  other  arlide 
of  glass  from  Italy,  which  could  be  made  there  of  a 
finer  quality  than  had  at  that  time  been  produced 
in  England  ^.  Common  pit  coal  is  however  tlie 
fuel  which  is  now  employed  throughout  England  for 
making  all  kinds  of  glass. 

In  the  reign  of  King  Charles  the  Second  a  Mr. 
Ravenscroft  very  materially  improved  the  niannfiBU>- 
ture  of  flint  glass.  He  is  said  to  have  made  all  lands 
of  glass  drinking- vessels  of  a.quali^  fully  equal  to 
any  that  were  then  manufactured  abroad. 

The  Duke  of  Buckingham,  who  had  brought 
workmen  from  Venice  for  the  purpose^  was  likewise 
the  means  of  establishing,  about  the  year  1670,  a 
considerable  work  at  Lambeth  for  the  manufacture 
of  fm^  plate  glass  ^^ 


^  Rymer,  tome  xix.  p.  663. 

^0  Campbell's  Political  Survey  of  Great  Britain,  vol.  ii.  p.  28. 
*■  Houghton's  Collections  on  Husbandry  and  Trade,  vol.  ii. 
p.43. 


cm  THE  MANUFACTURE  OF  GhASS.  183 

Thus  by  degrees  was  the  manufacture  of  every 
land  of  glass  introduced  into  this  country ;  and  the 
trade  made  such  rapid  progress  amongst  us,  that 
in  ^  year  1696  there  were  no  less  than  ninety 
glass-houses  in  the  different  parts  of  the  kingdom. 
Of  this  number  twenty-four  were  in  London  and 
,Southwark,  seventeen  at  Stourbridge,  eleven  ai|t 
Newcastle-upon-Tyne,  and  nine  at  Bristol.  The 
l€8t  were  dispersed  in  those  other  counties  of 
England  where  coal  is  readily  procured.  Of  these 
different  manufactories  forty- two  were  called  Bottle- 
houses,  or  such  as  were  chiefly  employed  in  making 
the  common  black  bottles ;  five  were  employed  for 
larown  glass;  twenty-seven  for  flint,  green,  and 
other  ordinary  glass ;  two  in  making  plate-glass  for 
mirrors,  &c. ;  and  fourteen  were  exclusively  appro- 
priated to  the  manufactures  of  window  glass^^. 

We  may  naturally  suppose  that  such  a  variety  of 
establishments  would  give  a  permanence  to  any 
manufacture.  This  has  really  been  the  case ;  for, 
at  this  day,  the  art  of  glass-making  has  become  one 
of  the  staple  manufactures  of  our  country. 

It  has  already  been  shown  that  there  are  five  dif- 
ferent kinds  of  glass-houses  in  this  kingdom ;  but 
before  we  attempt  to  describe  any  of  the  operations 
.which  are  performed  in  them,  it  will  be  necessary 
to  enumerate  them  afresh,  as  they  are  now  rather 
differently  distinguished  from  what  they  were  a 


^  See  further  particulars  in  Houghton's  CoUecHons,  vol.  ii. 
p.  48. 


184  ON  THE  MANUFACTURE  OF  GLASS. 

hundred-and-twenty  years  ago,  the  time  of  which 
we  have  just  been  speaking. 

The  English  glass-houses  are  now  known  by  the 
names  of  the  Crown  or  Window  glass-house ;  the 
Broad  glass-house ;  the  ^o//^-house ;  the  FUnt^ 
house ;  and  the  P/a/^-glass-house.  The  glass  trade 
of  Great  Britain  has  indeed  become  so  consideraMe, 
that  in  general  there  are  separate  and  distinct  esta- 
blishments for  each  of  these  species  of  glass.  I 
know  of  no  instance  of  the  same  proprietors  being 
concerned  in  more  than  one  or  two  of  these  dif- 
ferent branches  of  glass-making. 

It  will  be  most  convenient,  however,  and  the 
nature  of  the  whole  manufacture  will  probably  be 
better  understood,  if  we  begin  the  account  of  the 
different  manipulations,  by  a  description  of  the  me- 
thod which  is  adopted  in  making^t;i/  glass.  Hie 
following  is  the  process : 

Lynn  Sand 3  cwt. 

Red  Lead 2  — 

Pearlash 1  — 

To  these  are  added  a  very  small  quantity  of  nitre, 
of  manganese,  and  of  white  arsenic;  and  when 
these  materials  have  been  well  mixed,  the  whole  are 
combined  with  about  one-fourth  of  their  weight  of 
old  broken  flint  glass.  These  proportions  are  fire- 
quently  a  little  varied,  each  manufacturer  having 
his  own  ideas  and  peculiar  practical  knowledge  on 
the  respective  properties  of  every  ingredient. 

It  should  however  be  mentioned,  before  we  pro- 
ceed, that  some  houses,  instead  of  Lynn  sand,  use 


OK  tHE  MANUFACTURE  OF  GLASS.  l85 

ft  irery  white  sand  from  Alum-bay  in  the  Isle  of 
Wight,  and  others  procure  it  from  Maidstone  in 
Kent ;  and  that  the  pearlash  is  always  previously 
purified  for  this  purpose.  The  following  is  the  pro- 
eesa: — First,  it  is  dissolved  in  water,  and  suffered  to 
lemain  some  time  undisturbed,  to  allow  the  impu- 
rities and  contingent  matters  to  subside ;  after  this 
the  clear  solution  is  submitted  to  the  action  of  heat, 
to  expel  the  water  and  to  reduce  the  alkali  again  to 
a  dry  state.  One  hundred  weight  o{ first  ^  Ame- 
tiean  pearlash  is  thus  generally  reduced  to  70  or  80 
pounds. 

The  materials  being  mixed,  they  are  then,  by  a 
few  shovels  full  at  ^  time,  cast  into  the  crucible, 
previously  brought  to  a  white  heat ;  and  as  these 
melt,  tnore  is  thrown  in  until  the  pots  or  crucibles 
are  all  full,  care  being  taken  that  the  same  tem- 
perature is  continued  till  the  ingredients  are  tho- 
roughly united,  and  the  whole  formed  into  a  per- 
fectly transparent  glass.  The  operation  requires 
generally. from  20  to  30  hours. 

Flint  glass  is  known  to  be  perfect  when  the  silica 
is  all  dissolved,  and  the  paste  is  entirely  free  from 
sand  specks  and  air  bubbles.  This  however  is  never 
the  case  till  the  highest  point  of  heat  is  attained, 
and  the  metal  (a  technical  term  of  the  workmen 
for  glass  in  a  state  of  fusion)  has  become  sufficiently 

^'  The  potash  and  pearlash  of  America  are  sorted  into  three 
kinds  by  Government  Officers  chosen  for  the  purpose  \  and  they 
mark  the  casks  first,  seconds,  or  tHrda,  according  to  their  re- 
spective qualities. 


186  ON  THE  MANUFACTURE  OF  GJ*A8S. 

fluid  to  allow  of  the  carbonic  acid  gas .  and  other 
volatile  matters  to  rise  freely  through  the  mass  and 
escape.  It  is  usual  to  ascertain  the  purity  of  the 
glass,  by  taking  out  a  few  ounces  and  blowing  if 
into  the  shape  of  a  long  pear,  with  a  small  cayi^ 
within.  This  when  cold  is  inspected,  as  a  kind  of 
proof  or  sample  of  the  state  of  the  glass  in  fusioou . 

When  the  glass  is  found  to  be  completely  fonnedi 
the  workmi^n  dip  their  instruments,  which  are  long 
hollow  tubes  of  iron,  into  the  melted  metal,  and# 
turning  them  about  several  times,  they  collect^  <mi 
the  point  of  the  instrument,  as  much  of  it  as  thcf 
require  for  any  particular  purpose  which  they  QQay 
have  in  view.  Then,  by  blowing  with  the  luoutb 
and  rolling  the  hot  metal  upon  a  smooth  horizontal 
iron  plate,  they  form  it  intp  any  shape  that  may  be 
desired,  such  as  glasses,  decanters,  phials,  &e» 

This  part  of  the  process  is  extremely  interesting 
and  even  captivating  to  those  who  have  never  before 
seen  the  operation ;  for,  without  inspecting,  no  one 
can  form  an  adequate  idea  of  the  facility  with  which 
the  workmen  form  all  sorts  of  vessels  and  instru*' 
ments  of  this  very  curious  and  valuable  material. 

As  it  may  be  difficult  for  some  persons  who  have 
not  seen  a  glass-house  to  conceive  how  so  mu<A 
glass  in  the  state  of  melting,  as  is  necessary  for 
making  a  large  vessel,  can  be  taken  up  on  the  end  of 
an  iron  tube,  it  is  proper  to  state,  that  every  time 
the  workman  dips  the  instrument  into  the  crucible 
of  melted  glass  he  exposes  it  a  moment  to  the  cur- 
rent of  air,  which  chills  the  surface,  and  enables  an- 


ON  TH£  MANUFACTUKE  OF  GLASS.  187 

other,  portion  of  me^l  to  attach  itself  to  the  former:; 
find  this  he  repeats  till  he  has  collected  a  quantity 
sufl&eient  for  his  purpose. 

'■  In  the  large  houses,  many  workmen  are  con- 
(litantly  employed  both  day  and  night,  because  it  is 
necessary  that  the  work  should  go  on  without  inter- 
mission, till  all  the  metal  in  the  furnace  be  e^* 
baoBted.  Ea^h  of  these  men  has  a  boy  to  attend 
him ;  and  these  children  are  perpetually  employed 
ID  carrying  the  articles,  the  moment  they  are  made, 
one  by  one,  to  the  Her  or  annealing  furnace,  where 
they,  are .  kept  for  many  hours,  in  order  that  they 
may  cool  gradually. 

The  lier  is  a  very  long  heated  chamber,  furnished 
with .  many  shallow  iron  pans,  called  Iter^pans  or 
frmches,  for  holding  the  goods ;  and  these  are 
moved  further  and  further  from  the  fire  by  means 
of  )a  set  of  pulleys  and  a  windlass,  till  they  are 
brought  to  the  other  end  of  the  gallery,  where  the 
temperature  is  so  much  reduced,  that  in  general 
the  articles  are  all  sufficiently  cool  to  be  taken  out 
with  safety. 

I  observe  in  passing  that  the  term  lier-pan  is 
perhaps  derived  from  the  French  word  lieVy  to  bind 
or  knit  togethei* ;  from  an  idea  that  the  glass  was 
not  completely  formed,  or  its  particles  properly 
united^  until  it  had  gone  through  the  process  which 
wenowoall  annealing;  and  that  the  word Jrai&Aes 
h  derived  probably  from  the  French  fraiche^  cool, 
or  refiraichirj  to  cool. 

This  process  of  annealing  is  absolutely  necessary 


188  OK  THE  MANUFACTURE  OF  GLASS* 

for  the  production  of  perfect  glass,  whatever  may 
be  the  kind,  or  whatever  the  form  of  the  article 
which  is  made  with  it.  Hence,  it  may  be  under- 
stood why  glasses  often  break  without  any  apparent 
cause ;  for,  whenever  this  happens,  it  may  be  attri- 
buted  to  imperfect  annealing,  unless  one  side  of  a 
piece  be  more  exposed  than  the  other  to  heat  or 
cold ;  for  then  it  will  inevitably  crack,  because  glass 
is  a  worse  conductor  of  heat  than  any  manufactured 
commodity  with  which  we  are  acquainted.  This 
property  of  glass  being  a  non-conductor  of  heat,  is 
often  exemplified  in  a  curious  manner  in  the  glass- 
house. The  following  is  a  case  that  may  be  men- 
tioned. When  a  crucible  full  of  liquid  glass  breaks 
by  accident,  a  large  tub  of  water  is  brought  to  the 
mouth  of  the  oven,  and  the  fluid  metal  is  laded 
with  all  possible  expedition  into  it,  to  prevent  its 
running  into  the  furnace  and  being  lost  among  the 
ashes.  When  this  large  mass  of  glass  has  been 
some  little  time  in  the  water,  its  surface  will  become 
nearly  cold,  while  the  centre  of  it  will  be  red  ho^ 
and  continue  so  for  several  hours  after  the  outside 
has  been  cold  enough  to  be  handled  with  safety. 

Having  thus  given  a  very  brief  account  of  the 
method  of  making  flint  glass,  it  may  be  remarked, 
that  either  of  the  fixed  alkalies,  with  a  due  propor- 
tion of  flint  or  sand,  will,  without  any  other  ingre- 
dient, make  a  pure  and  transparent  glass.  A  cen- 
tury ago  the  best  glass  was  always  made  from 
ground  flints  :     hence  it  was   that   white  glass 


ON  THE  MANUFACTURE  OF  GLASS.  189 

acquired  the  name  of  flint  glass ;  but  when  it  was 
discovered  that  good  sand  is  nearly  all  siliceous 
earth,  this  was  substituted  for  flints. 

The  other  materials,  viz.  the  lead,  manganese, 
nitre,  and  arsenic,  are  therefore  added  with  different 
intenUons;  and  the  proportions  which  are  noted 
above  are  sometimes  praried,  for  the  sake  of  pro- 
ducing a  glass  of  a  quality  different  from  that  which 
18  usually  made. 

Thus,  the  lead  is  employed  with  the  design  of 
giving  a  greater  degree  of  fusibility  to  the  silica,  to 
add  weight  to  the  glass,  to  enable  such  of  it  as  is 
designed  for  ornamental  work  to  take  a  higher 
polish,  and  to  render  it  less  liable  to  break  by  sud- 
den changes  of  temperature. 

Besides  the  several  uses  of  lead  which  I  have 
enumerated,  it  has  another  effect  upon  all  orna- 
mental flint  glass,  which  is  of  great  importance; 
for  it  has  the  property  of  increasing  the  refractive 
power  of  the  glass ;  and  hence  we  are  enabled  to 
decompose  the  solar  rays  of  light,  by  means  of  a 
glass  prism,  into  what  are  called  the  prismatic 
colours.  Lead  is  a  simple  combustible,  and  so  are 
the  diamond  and  hydrogen.  It  was  Sir  Isaac 
Newton  who  first  suggested  that  the  diamond, 
from  its  refractive  power,  was  of  a  combustible 
nature,  and  that  water  also  must  have  something 
in  its  composition  that  would  burn,  as  it  breaks  the 
rays  of  light.  Thus  can  we  account  for  the  supe- 
rior beauty  of  the  English  flint  glass.  Plate-glass 
possesses  no  such  brilliancy. 
The  employment  of  oxide  of  lead  in  tlie  manu* 


190  ON  THE  M ANUFACTURB  OF  GLASS. 

fiftcture  of  glass  is  very  ancient.  In  the  coUecti<m 
of  antiquities  at  St.  Denis,  an  ancient  mirror  was 
shown  which  was  said  to  have  belonged  to  VirgiL 
It  was  an  oval  glass,  14  inches  in  length  and  12  in 
breadth,  and  weighed  30  pounds.  This  was  fdand 
on  analysis  to  consist  of  artificial  glass,  mixed  witH 
a  considerable  portion  of  lead^. 

To  explain  the  use  of  the  other  ingredients,  it 
may  be  said  that  the  manganese  and  the  nitare  are 
of  service  in  destroying  whatever  carbonaceous  sub- 
stances may  be  in  the  mixture.  The  white  oxide 
of  arsenic  is  also  used  mth  the  same  intentiooi 
The  employment  however  of  this  dangerous  iogre^ 
dient  ought  surely  to  be  discontinued  in  the  maun* 
facture  of  drinking-vessels,  because  wherever  the 
glass  contains  an  overdose  of  alkali,  it  is  liable  to 
be  attacked  by  acids  i:  therefore  acidulous  wini^ 
standing  long  in  a  decanter  might  abstract  some  of 
the  poisonous  oxide,  and  produce  infinite  mischief 
But  this  is,  I  fancy,  seldom  employed  now,  except 
where  the  manager  suspects  that  the  materials  havi6 
been  either  not  sufficiently  purified,  or  that  the 
calcination  had  not  been  properly  conducted ;  each 
of  these  articles  having  the  property  of  abstracthig 
the  carbon,  and  dissipating  it  in  the  form  of  car* 
bonic  acid  gas,  leaving  the  glass  whiter  a^nd  more 
transparent.  There  is  however  some  nicety  always 
i'equired  in  the  use  of  the  oxide  of  arsenic ;  for, 
though  it  makes  the  glass  whiter,  it  will  giv^  it  an 


<♦  See  Hist,  de  VAcad,  dts  Sciences  it  Paris,  ann^e  1787, 
p.  412  J  and  Beckmann^  vol.  iii.  p.  210. 


OK  THE  MANUFACTURE  OF  GLASS.  lAl 

opake  or  rather  an  opal  appearance,  if  too  mucK  of 
it  be  employed.  Some  manufacturers  of  flint  glass 
have  discontinued  it  altogether,  because  they  con- 
ceive that  the  lead  renders  the  arsenic  too  volatile 
to  be  of  much  sendee. 

The  next  species  of  glass  to  be  described  is  that 
which  is  known  in  the  trade  by  the  name  of  crown* 
glasSj  being  in  fact  the  best  sort  of  window  glass 
which  is  made  in  this  country. 

The  apparatus  employed  in  the  manufacture  of 
CROWN-GLASS  are,  a  reverberatory  furnace  for  caU 
cining  the  materials;  a  large  furnace  containing 
the  pots  or  crucibles  for  melting  these  materials  and 
forming  them  into  glass  ^^ ;  and  other  furnaces  for 
heating  or  annealing  the  crucibles,  previously  to 
Iheir  being  employed.  Besides  these,  there  are 
others  which  contain  no  crucibles,  but  are  merely 
employed  for  re-heating  the  metal  time  after  time, 
to  enable  the  workmen  to  keep  it  sufficiently  ductile 
for  being  thrown  into  such  forms  as  they  require. 
The  bottoming-hole  and  the  flashing-furnace^  as 
they  are  called,  both  come  under  this  description. 
There  are  many  other  technical  terms  in  this  busi- 
ness: but  they  are  all  formed  either  from  the  Italian 
or  the  French  language,  glass  having  been  long 
made  in  those  countries,  and  it  was  ^rom  them  that 
this  art  passed  into  the  other  states  in  Europe. 

^*  One  of  these  furnaces  generally  takes  four  or  six  pots ; 
and  these  are  so  large^  that  some  of  them  are  capable  of  holding 
more  than  a  ton  weight  of  gloss. 


192  ON  THE  M ANUFACTUR£  OF  GLASS. 

The  materials  which  are  employed  in  makiog. 
the  best  crown  glass  are  as  follow : 

Fine  Lynn  Sand 6  bushds. 

Orkney  Kelp 12 

These  are  the  usual  proportions ;  but  some  kelp 
will  vitrify  more,  and  some  less  sand  than  has  been 
mentioned,  because  of  the  variation  which  there  is 
in  the  quality  of  what  is  called  best  kelp. 

Orkney  kelp  is  preferred  for  window  glass,  be- 
cause it  makes  it  of  a  better  colour  than  the  Westr 
em  Isle  or  the  Scotch  kelp.  This  is  probably  owing 
to  the  sand  of  the  latter  containing  more  iron.  Mr. 
Bowles,  the  celebrated  maker  of  crown-glass  at 
Cock-hill,  Ratcliffe-highway,  London,  always  used 
Spanish  barilla  instead  of  kelp,  and  his  glass  was 
ever  preferred  to  that  of  others.  This  gentleman 
had  also  an  establishment  at  Vauxhall  for  making 
plate-glass :  but  the  concern  has  been  abandoned 
for  more  than  twenty  years,  the  proprietor  having 
retired  with  an  ample  fortune. 

It  appears  to  me,  that  it  would  be  a  better  prac- 
tice to  dry  the  materials  thoroughly,  and  then  to 
apportion  them  by  weight  instead  of  by  measure  as 
above  mentioned.  By  repeated  inquiries  I  have 
indeed  learnt  that  one  of  the  large  manufacturers 
has  adopted  this  method,  and  that  the  following 
are  his  general  proportions : 

Irish  Kelp,  dried  and  ground    .    .     .    450  lU. 

Lynn  Sand,  dried 325  — 

Slacked  and  Sifted  Lime     ....      25  — 

800  lbs. 


ON  THE  MANUFACTURE  OF  GLASS.  193 

These  materials,  when  thoroughly  mixed,  are 
calcined  for  about  two  hours  in  a  degree  of  tem- 
perature inferior  to  that  of  fusion  ;  the  fusion  being 
in  some  measure  prevented  by  constantly  stirring 
the  mass,  which  occasions  a  fresh  surface  to  be 
perpetually  presented  to  the  action  of  the  fire,  and 
also  favours  the  escape  of  the  aqueous,  gaseous,  and 
other  volatile  matters  which  are  required  to  be  dissi- 
pated by  the  process.  The  heat  is  then  increased 
till  the  whole  becomes  pasty ;  and  it  is  preserved 
in  this  state  for  three  or  four  hours  more,  constantly 
stirring  the  mass  during  the  whole  period.  The 
vnaterials,  which  are  still  in  a  soft  and  pasty  state, 
are  at  length  removed  from  the  furnace,  and,  ad- 
vantage  being  taken  of  the  softened  state  of  the 
mass,  the  whole  is  put  very  hastily  into  the  form  of 
square  cakes,  which  are  known  to  the  workmen  by 
the  name  oi  frit,  the  operation  itself  being  called 
fritting.  Some  years  ago  I  remember  to  have  been 
very  much  at  a  loss  to  account  for  it,  why  it  was 
necessary  to  make  the  glass  first  into  frit,  and  why 
it  might  not  be  begun  and  finished  by  one  process; 
but  I  now  understand  that  whenever  this  previous 
operation  is  not  performed,  the  alkali  is  apt  to  be 
driven  off  by  the  heat  of  the  furnace,  before  it  has 
time  to  combine  sufficiently  with  the  silica ;  whereas, 
in  the  operation  of  fritting,  the  temperature  is 
powerful  enough  to  effect  this,  and  yet  not  equal  to 
volatilize  the  uncomhined  alkali. 

Tlie  manufacturers  of  glass,  I  trust,  will  not  be 
displeased  at  my  remarking  on  a  circumstance  which 

VQL.  II.  O 


194  ON  THE  MANUFACTURE  OF  GLASS. 

18  of  more  consequence  than  many  persona  are 
aware  of.  From  my  own  experiments,  I  am  wu^ 
ranted  in  saying  that  pure  alkali  evaporates  at  & 
lower  temperature  than  is  generally  imagpine<L 
Hence  great  attention  ought  to  be  paid  in  pfeparing 
Ihe^^^,  not  to  ^ve  it  too  great  a  heat,  or  to  remova 
it  from  the  calcining  oven  before  it  be  thoroogfalf 
prepared ;  otherwise,  the  alkali  will  fly  off  in  vapour 
instead  of  combining  mth  the  silica.  This  may  be 
often  seen  arising  as  a  vapour  from  the  surftiee  of 
the  crucibles  in  a  glass-house  furnace.  There  is 
on  this  account  an  advantage  in  using  soda  in  pie* 
ference  to  potash,  because  soda  combines  mom 
readily  with  the  siliceous  earth  ^. 

The  manufacturers  are  desirous  of  keeping  Ae 
frit  as  long  as  they  can ;  and  hence  it  is  that  tlM 
cakes  are  seldom  employed  immediately,  but  an 
generally  piled  up  in  a  comer  of  the  manufiM^tocy 
for  future  use,  it  being  a  prevailing  idea,  thai  the 
frit  is  better  the  older  it  is ;  and  I  have  been  in* 
fidrmed  that  some  of  the  opulent  makers  have  a 
r^ular  succession  of  it  in  store,  and  never  use  any 
that  is  not  twelve  months  old. 

To  prepare  for  making  crown-glass,  this  frit  is 
put  into  crucibles  in  the  melting  furnace;  and  when 
the  crucibles  are  filled,  old  glass  is  piled  upon  the 
frit,  as  high  as  it  can  be  placed  with  safety.     The 


i^-^ 


^  An  explanation  of  the  process  of  fritting^  and  an  accooat 
of  the  construction  of  the  fritting  ovens  in  France^  may  be  seen 
in  EnqfclopMe,  ou  Diet  Universe!,  SupplemeiU,  tome  tL 
quarto,  Yverdon,  1776,  p.  618. 


ON  THE  MANUFACTURE  OF  GLASS. 


19a 


furnace  is  then  made  liot,  and  the  heat  is  regularly 
increased  till  it  acquire  the  maximum,  at  which 
state  it  is  continued  for  30  or  -40  hours.  During 
this  time  the  materials  become  so  thoroughly  united 
as  to  form  one  perfectly  homogeneous  and  trans- 
parent mass  of  fused  metal,  fit  for  the  fabrication 
of  sheets  of  best  window  glass. 

To  make  this  species  of  glass,  the  workman  com- 
mences the  operation  as  he  would  in  the  flint-house, 
already  described.  He  dips  the  long  iron  pipe 
into  the  melted  metal,  and  by  repeated  dippings 
gathers*?  as  much  of  it  round  the  end  of  the  pipe 
as  he  knows  by  experience  will  be  enough  to  form 
a  table  of  glass.  A  tab/e  is  tlie  workman's  phrase 
for  a  circular  sheet  of  finished  window-glass.  These 
are  generally  4  feet  in  diameter,  and  weigh  10,  lOJ, 
or  I  i  pounds  each.  Twelve  of  these  is  called  a 
sitle  or  a  crate  of  glass. 

When  the  lump  of  metal  is  properiy  attached  to 
the  lHpe>  it  is  rolled  frequently  backwards  and  for* 
wuds  upon  a  polished  iron  table,  to  change  it  from 
a  globular  to  a  cylindrical  form.  The  workman 
thea  blows  down  the  tube,  to  which  the  red-hot 
piece  of  glass  is  attached  ;  and  by  this  means,  and 
a  continuatioa  of  the  rolling,  it  becomes  expanded 
into  a  form  similar  to  figure  A,  in  Plate  XIX., 
and  which  is  called  by  the  workmen  a  Parisiemie. 
He  then  carries  it  to  the  mouth  of  the  melting 


"  Til  gather  i»  a  technical  tmn,     The  meUl  which  U  taken 
'    ~    a  ii  called  a  gaifiaring. 
o2 


196  ON  THEMANUPACTURE  OF  GLASS. 

furnace  to  heat  it  afresh,  that  it  may  be  in  a  proper 
state  for  being  further  expanded  by  the  breath,  till 
it  takes  the  form  described  by  figure  B ;  ivhen  it  is 
immediately  transferred  to  the  furnace  called  the 
bottaming-hole^  to  be  again  heated;  and  this  en- 
ables  the  workman  to  enlarge  it,  by  the  mere  foice 
of  his  breath,  till  it  acquire  the  form  described  at 
figure  C ;  after  which,  by  heating  it  and  blowing 
afresh,  it  assumes  the  shape  of  figure  D.  Tlie 
artist  having  brought  it  into  this  latter  form,  the 
next  object  is  to  affix  another  working  iron  to  the 
opposite  side  of  the  piece  to  enable  him  to  detach 
with  safety  the  first  instrument.  The  intentioo  of 
this  contrivance  will  be  rendered  manifest  as  we 
proceed  in  our  description  of  the  process. 

To  efiiect  this,  the  workman  takes  the  glass  which 
haiB  been  so  far  modelled,  to  a  table  covered,  vrith 
ashes,  which  are  designed  to  prevent  the  adhesion 
of  the  glass  to  the  table,  and  also  to  preserve  the 
glass  from  too  great  a  reduction  of  temperature  $ 
and  while  lying  there,  a  supernumerary  worknian 
brings  another  working  iron^,  with  a  small  lump 
of  hot  metal  at  the  end  of  it ;  and  this  he  attadies 
to  the  piece  of  glass  under  operation,  at  the  letter 
>,  exactly  opposite  to  Zy  the  place  where  the  first 
iron  is  still  united. 

.  Having  by  means  of  this  small  lump  of  fiesh 
glass  attached  a  new  working  iron,  it  becomes  neces- 


^  This  instmmeQt  differa  from  the  former,  in  ha  not  bieing  a 
tube,  but  a  rod  of  solid  iron.    It  is  called  a  punt  or  poRfti. 


ON  THE  MANUFACTURE  OF  GLASS.  197 

aary  to  withdraw  the  fonner,  as  before  mentioned,, 
and  this  18  effected  by  the  usual  expedient.  The 
workman  wets  the  end  of  a  small  iron  utensil  with 
a  little  Gold  water ;  with  this  he  touches  the  glass  at 
ktter  Z^  where  it  produces  a  crack ;  then  by  a  smart 
stroke  he  detaches  the  old  instrument  from  it,  which 
leaves  a  hole  in  the  piece  of  glass  of  about  two 
ioches  in  diameter,  and  which  has  then  the  appear- 
ance shown  by  figure  E. 

,  A  new  working  iron  being  now  attached  to  the 
gbtts  exactly  at  the  opposite  point  to  that  where  the 
former  one  adhered,  the  workman  carries  it  by  the 
pont^  or  new  rod,  to  the  flashing  furnace,  and  turn- 
ingit  gently  in  his  hand,  holds  it  a  few  minutes  at  the 
$|iiall  opening  called  the  nose  hole.  This  is  a  tech- 
meal  name  by  which  these  openings  are  known  to  the 
workmen  in  the  North  of  England.  Agricola  and 
other  old  writers  on  glass  called  them  boccas.  This 
small  opening  into  the  large  furnace  is  contrived 
merely  for  the  purpose  of  heating  that  part  of  the 
HJlass  to  which  the  cold  water  had  been  applied. 
By  this  means  it  is  put  in  a  proper  condition  to  be 
introduced  into  the  larger  opening  in  the  same  fur- 
nace^ where  it  acquires  heat  by  degrees  till  the  ope- 
rator perceives  that  the  whole  mass  has  again  be- 
come sufficiently  ductile.  He  then  begins  to  turn 
it  quicker  and  quicker,  holding  it  the  whole  time 


^  These  instruments  are  smaller  and  lighter  than  the  blow- 
ing irons^  and  consequently  more  manageable  in  these  latter 
parts  of  the  process,  when  it  is  necessary  to  make  them  rerolve 
m  the  hand  with  greater  velocity. 


WB  ON  THE  MANUFACTURE  OF  OLASS^. 

at  the  mouth  of  the  oven,  till  it  becomes  so  mmb 
aoftened,  that  merely  by  the  centrifugal  force  com^ 
munioated  by  the  rafud  revolution  of  the  iron  inalniF 
ment  to  which  it  is  attached,  and  which  requiies 
great  dexterity  on  the  pcurt  of  the  workman,  Alt 
whole  mass  opens  itself  by  degrees,  extendingtetbir 
and  further  till  it  assumes  the  form  of  FO  mui 
H  in  succession ;  and  when  it  has  attuned  tbt  fa** 
ter  figure,  it  flies  entirely  open  m  an  imtmmi^  as 
shown  at  iT,  and  becomes  one  immense  droidar 
sheet  of  glass,  48  or  50  inches  in  diameter,  and  cf 
one  uniform  thickness.  It  was  formerly  thought  to 
be  a  great  acquisition  to  be  able,  by  this  procMb 
to  make  a  perfect  table  of  glass  four  feet  in  diinie- 
ter;  but  I  understand  that  Messrs.  Attwood  and 
Smith,  formerly  Hammond  and  Smith,  of  Cades 
head  in  the  county  of  Durham,  are  enabled  to  ffo- 
duce  tables  of  five  feet,  which  are  the  more  vdhiabli^ 
as  they  yield  larger  squares  than  were  ever  mads, 
except  in  plate  glass ;  and  the  quality  of  it  is  of  die 
best  kind.  The  centre  of  the  table  of  glass,  wtiaN 
the  punting  iron  was  attached,  is  of  course  some- 
what thicker,  and  is  known  to  the  workmen  by  die 
name  of  the  huUs  eye.  Notwithstanding  tfaisy  it 
is  curious  to  observe  how  very  uniform  in  thickaess 
all  the  rest  of  the  plate  is. 

This  account  of  the  varied  manipulations  is  pre* 
sented  to  my  readers  in  considerable  detail,  together 
with  drawings  of  the  glass  in  every  stage  of  its  pro- 
gress ^,  because  I  believe  the  production  of  diis  pe- 

^  See  the  engraving,  Plate  XIX.,  prefixed  to  this  Essay. 


ON  THE  MANUFACTURE  OF  GLASS.  Id9 

culiar  species  of  glass  to  be  one  of  the  most  curious 
and  interesting  processes  which  any  of  the  manufac- 
tures of  this  or  any  other  country  can  exhibit.  The 
teneicity  of  heated  glass  is  sliown  in  a  very  striking 
manner  by  this  operation  ;  for  thougli  the  plate  be 
50  inches  in  diameter,  and  not  more  tlian  a  line  in 
thickness,  it  bears  to  be  revolved  in  the  hands  of 
the  workman  with  considerable  celerity;  and  when 
it  changes  by  its  centrifugal  power  from  figure  H  to 
figure  K,  it  expands  with  a  force  sufttcient  to  dash 
it,  if  it  were  cold,  into  ten  thousand  pieces.  The 
workmen  assured  me  that  this  circumstance  never 
foils  to  arrest  the  attention  of  every  visitor. 

When  the  crown-glass  is  thus  finished,  the  per- 
fect plate  is  removed  into  the  annealing  arch,  and 
there  placed  on  its  edge  that  it  may  become  properly 
tempered  by  gradual  cooling,  as  is  practised  in  the 
manufacture  of  every  other  sort  of  glass.  It  is  a 
very  nice  point  to  regulate  the  temperature  of  the 
annealing  arch  for  a  small  excess  of  heat  would 
render  the  plates  so  soft  that  they  would  bend  out 
of  the  perpendicular  and  be  much  injured:  on  the 
contrary,  if  the  furnace  be  not  hot  enough  there  is 
great  danger  of  the  plates  flying  in  pieces,  though 
if  this  should  not  happen  the  defect  would  inevitably 
he  discovered  by  the  glazier ;  since  glass  so  imper- 
fectly annealed  is  operated  upon  by  the  diamond 
with  great  difficulty,  and  it  is  alnio.st  impossible 
ever  to  cut  it  with  exactness. 

In  the  fabrication  of  crown-glass,  nothing  is  of 
more  importance  than  to  keep  the  meldng  furnace 


200  ON  THE  MANUFACTURE  OF  GLA8I; 

at  its  full  beat  during  the  whole  time  of  the  opera-* 
tion ;  for,  whenever  the  men  fedl  asleep,  whidi 
they  are  apt  sometimes  to  do,  the  heat  of  the  oven 
gets  checked,  and  it  is  almost  impossible  to  faring 
it  again  to  the  former  temgierature. 
-  This  arises  from  the  peculiar  property  wfaicb 
glass  possesses,  that  of  being  a  slow  conductor  of 
heat ;  and,  unfortunately,  the  further  the  glass  is  ad-' 
vanced  towards  perfection  the  greater,  will  be  its 
liability  to  damage  from  this  cause ;  and  therefiore 
the  more  solicitous  should  the  manufacturer  b^i 
to  watch  this  part  of  the  process.  This  accident  is 
of  such  frequent  occurrence,  that  it  alone  has  been 
the  chief  means  of  occasioning  crown-glass  to 
be  divided  into  four  classes,  viz.  fi^ts,  seconds^ 
^lirds,  and  fourths ;  between  the  two  extremes  of 
which  there  is  a  difference  of  50  per  cent,  in  price. 
Indeed,  if  the  excise  duty  be  put  out  of  considera- 
tion, the  glass  of  the  fourth  quality  nets  the  manu* 
facturer  less  than  half  the  price  of  the  first.  In  one 
of  the  largest  crown-houses  which  I  have  seen, 
where  they  make  1800  tables,  or  150  sides  per 
week  throughout  the  year,  they  consider  one-half  to 
two-thirds  of  this  quantity  to  consist  of  seconds  and 
thirds.  When  the  firsts  were  sold  at  6/.  10^.  per 
side,  the  thirds  brought  only  4/.  1 8^.,  the  duty  being 
paid  by  the  maker. 

The  next  species  to  be  described  is  Broad-glass^ 
or  inferior  window  glass.  This  is  quite  a  distinct 
manufacture  from  that  of  crown-glass,  and  the  pro* 


oil  THE  MANUFACTURE  OF  GLASS.  201 

oess  of  fabricating  it  is  also  totally  dissimilar.  The 
materals  which  are  employed,  and  the  method  of 
eonduding  the  operation,  are  as  follow : 

Six  bushels  of  soap-boilers*  waste  ^  i,  three  bushels 
of  kelp,  and  four  bushels  of  sand  are  mixed  together 
and  cast  into  a  calcining  furnace.   But  there  is  no 
ibiolute  rule  for  the  proportions,  because  the  two 
first  of  these  materials  are  as  variable  in  their  qua- 
lities as  can  well  be  conceived,  and  therefore  the 
operator  is  always  guided  by  his  own  judgement 
in  apportioning  the  respective  quantities,  and  no-* 
thing  but  practice  can  direct  him. 
^  I  have  not  found  that  the  proprietors  of  those 
houses  where  broad-glass  is  made  lay  any  stress  on 
the  fineness  of  the  sand  ;  but  this  is  certainly  an  im« 
portant  circumstance.     Loysel  has  stated,  as  the 
result  of  his  own  experience,  that  if  coarse  sand  be 
osed^  21bs.  of  pure  alkali  must  be  put  to  every  41bsk 
of  sand,  or  it  will  not  melt ;  whereas  if  the  sand 
were.very  fine,  lib.  of  pure  soda  would  be  sufficient. 
Hence  it  follows,  that  there  remains  in  the  finished 
l^assy  as  a  constituent  part  of  its  substance,  only 
one  half  of  the  alkali  at  first  employed.   The  other 
tialf  is  dissipated  during  the  process,  and  entirely 
lost^. 

-. .  The  process  of  calcining  the  materials  requires 
from  twenty  to  thirty  hours,  and  is  designed  to  burn 
off  all  the  inflammable  and  heterogeneous  matters 

^'  Tliis  is  the  refuse  article  which  is  spoken  of  at  page  1 1  of 
tlus  vohune. 
"  Loysel,  page  180. 


20}  OV  TH£  MANUFACTUER  OF  OsAtS. 

which  would  spoil  the  colour  of  the  ^ass,  at  well  is 
enchnger  its  boiliiig  over  when  it  came  into  the 
melting  furnace.  It  is  observable  that  the  mate* 
rials  are  not  suffered  to  melt  while  in  the  calcining 
fomace^  but  are  kept  at  a  great  heat  and  stiried 
very  frequently  with  an  iron  rake,  wfaieh  ftunlitafeea 
the  separation  of  the  gas,  and  completes  the  eom^ 
bostion  of  all  sndi  contingent  matters  as  ate  eajpai* 
ble  of  this  change. 

When  the  mass  has  been  thus  properly  calcusadj 
it  is  removed  with  iron  shovels  while  red  hol^  and 
carried  to  the  melting  furnace,  where  the  pota  MS 
entiiely  filled  with  it ;  and  in  the  course  of  twelve 
or  fifteen  hours  of  exposure  to  a  due  degree  of  beat» 
the  whole  will  become  perfect  glass.  To  form  tkk 
into  sheets,  the  following  method  is  pursued :    ' 

The  glass  is  withdrawn  from  the  pots  by  iron 
tubes  in  the  way  already  described  for  the  flint  and 
crown-glass  ^,  and  it  is  blown  into  globes,  or  rathav 
into  hollow  cones^  of  about  a  foot  diameter.  It 
must  be  recollected  that  all  glass,  the  large  plate* 
glass  excepted,  whatever  be  its  form,  whether  that 
of  an  electrical  tube,  a  goblet,  a  decanter,  or  a  sheet 
of  window  glass,  is  all  fiashioned  from  a  hoUow 
sphere  produced  by  the  action  of  the  breath.  That 
is,  a  piece  of  fluid  metal  is  first  blown  into  a  hoUow 
globe,  and  then  it  is  moulded  by  the  workman  into 
the  desired  shape.  When  these  globes  are  formed^ 
they  are  carried  again  to  the  mouth  of  the  oven,  and 

»  See  pages  180  and  195. 


OM  TH£  MAMUrACTUHE  OF  GLA8B.  203 


vhik  there,  one  side  is  touched  with  a  cold  iron 
dipped  in  water.  Tliis  produces  a  cracl^  which 
cons  along  it  longitudinally  in  nearly  a  direct  line. 
When-  this  crack  is  produced,  the  cone  is  opened 
iqion  a  smooth  iron  plate  fixed  at  the  mouth  of  the 
famace,  and  it  then  forms  a  sheet  of  thin  transpa- 
mt  window  glass  in  a  shape  somewhat  like  that  of 
a  fiui.  In  a  few  minutes  this  becomes  hard  enough 
to  admit  of  being  removed  to  the  annealing  apart* 
swttt,  that  its  temperature  may  gradually  diminish. 
This  spedes,  which  is,  probably,  the  first  that  was 
ever  manufactured  for  the  use  of  mndows,  is  called 
kvad  or  spread  window-glass,  to  distinguish  it 
fiom  what  is  termed  the  crown-glass. 

Another  kind  not  yet  described,  is  a  green  glass, 
known  to  the  trade  by  the  name  of  Bottle-glass, 
and  the  works  at  which  it  is  manufactured  are  call- 
ed boHle-houses. 

To  make  this  species  they  take  three  bushels  of 
soap-makers*  waste  ashes,  and  one  bushel  of  coarse 
liver  sand.  Sometimes  a  portion  of  kelp  is  also 
added,  but  this  is  not  used  in  all  manufactories. 
These  materials  are  calcined  either  in  a  distinct  fur« 
naee,  or  in  arches  attached  to  the  furnace  of  fusion, 
where  they  are  kept  at  a  red  heat  for  twenty  or 
thirty  hours  ^.  From  thence  the  mixture  is  removed, 
sdU  of  a  red  heat,  to  the  melting  furnace,  where  by 

••  Ncri  prescribes  only  10  or  12  hours,  see  Merrct's  Trans- 
lition,  page  272 ;  but  I  have  reason  to  think  that  the  modem  is 
the  better  practice. 


204  OM  THE  MANUFACTURE  OF  GLASS. 

means  of  iron  shovels  the  pots  or  crucibles  are  filled 
with  it^and  an  intense  heat  is  again  applied.  Byoon« 
tinning  the  materials  in  this  high  temperature  for 
twelve,  fifteen,  or  eighteen  hours  longer,  they  be- 
come perfectly  fused  and  converted  into  a  true  glais^ 
fit  for  making  wine  bottles,  garden  bell  glassesy  die? 
mical  retorts,  aquafortis  carboys,  and  any  other 

large  vessels  for  chemical  laboratories  or  other  pure 
poses. 

These  articles  are  all  fashioned  by  a  method  si- 
milar to  that  which  has  been  described  under  the 
article  flint  glass  ^,  excepting  half-pint,  pinty  and 
quart  bottles,  which  are  blown  in  a  mould  either  «f 
iron  or  brass.  These  goods  are  likewise  removed^ 
while  yet  very  hot,  to  the  annealing  furnace,  for  the 
purpose  already  mentioned  in  describing  the  other 
species  of  glass. 

The  bottle  metal  is  peculiarly  fit  for  making 
chemical  carboys,  as  it  bears  the  action  of  all 
the  mineral  acids  without  sustaining  any  injury ; 
whereas  flint  glass,  which  is  usually  made  with,  a 
large  portion  of  lead,  is  very  unfit  for  any  chemi- 
cal purpose  that  requires  much  heat.  Bottle-glasi^ 
which  is  always  made  without  lead,  will  bear  a  greater 
heat  without  melting,  and  therefore  is  much  better 
adapted  to  many  of  our  operations. 

A  few  observations  now  present  themselves  as  Oja- 
cessary  to  be  offered  on  the  process  of  bottle-glass^  be- 
fore we  proceed  with  the  remainder  of  our  subject. 

The  soap-makers*  residuum  contains  a  very  great 

■I  ■  ■  ,    .  I    .  ■  11^ 

»»  See  the  Text  at  pages  18f0^188. 


ON  THE  MANUFACTURE  OF  GLASS.  205 

proportion  of  carbonate  of  lime,  which  is  better 
for  this  purpose  than  lime  itself,  inasmuch  as  k 
helps  to  decompose  the  sulphates  of  soda  and  pot- 
ash, which  are  always  contained  more  or  less  in 
■oap  waste,  as  well  as  in  kelp  and  the  other  alka- 
lies of  commerce. 

There  must  be  a  great  loss  in  using  the  sand 
in  its  coarse  state,  for  the  reasons  already  assigned. 
In  some  glass-houses  on  the  Continent  it  is  usual 
.to  b^t  the  sand  red  hot,  and  then  throw  it  sud- 
denly into  cold  water,  in  the  same  way  as  the  pot- 
tors  treat  their  flint  to  break  it  into  smaller  grains. 
yfhj  might  not  our  manufacturers,  *  where  coal 
is  cheap,  adopt  this  practice  ?  If  pains  were  also 
taken  to  wash  the  Woolwich  sand  repeatedly  in 
seferal  waters,  the  colour  of  the  glass  made  with 
it,  would,  I  conceive,  be  much  improved. 

Government  will  not  allow  the  makers  of  this 
species  of  glass  to  use  any  but  the  commonest  river- 
sand,  lest  the  glass  should  be  too  good,  and  the 
•revenue  be  defrauded  by  its  being  applied  to  pur- 
poses lor  which  the  best  glass  is  generally  used, 
and  which  pays  a  higher  duty.  The  greatest  pro- 
pMtion  of  the  sand  which  is  used  in  bottle  glass  is 
obtained  from  the  river  Thames  at  Woolwich. 

I  have  reason  to  believe  that  at  most  of  our 
jBliglish  bottle-houses,  the  calcining  is  conducted 
in  arches  communicating  with  the  furnace  in  which 
the  metal  is  founded.  In  those  houses  which  I  hav^ 
seen  there  is  an  arch  at  each  corner  of  the  main 
fiimace,  and  in  these  arches  the  materials  remain 


206  ON  THE  M AMUFACrU  RE  OF  GLASS. 

not  only  the  whole  time  of  fomiding  the  former 
parcel  of  glass,  hot  also  during  the  time  of  its  being 
worked  up  into  bottles,  &e.  which  is  generally  10 
or  12  hours  more.  Care  is  taken  at  the  latter  part 
of  this  period  to  bring  the  calcined  mixtore  in  tlie 
arches  to  such  a  temperature,  that  it  may  be  moved 
immediately  from  thence  into  the  hot  crucibles 
without  danger  of  breaking  them. 

In  the  neighbourhood  of  Newcastle-upon-TfBi^ 
bottle-glass  is  made  very  profitably  from  a  mixtnre 
of  lime  and  sea  sand,  the  mass  having  been  ftrit 
repeatedly  wet  widi  salt-water.  Where  glass  Is 
tbnis  attempted  to  be  made  without  any  alkali,  ei6- 
eept  what  is  contained  in  the  muriate  of  soda,  Hmfe 
is  absolutely  necessary ;  for  this  earth  when  in  eon- 
junction  with  silica  seems  in  a  high  temperature 
to  have  the  power  of  decomposing  common  salt. 

1  cannot,  however,  speak  decisively,  because  I  ham 
doubts  on  this  subject.  I  wish  some  manufitctnrer, 
who  has  a  favourable  opportunity  for  making  the 
experiment,  would  have  the  goodness  to  satisfy  me 
upon  tills  point.  The  alkaline  sufyfhaies  I  know 
are  decomposed  by  a  mixture  of  charcoal  and  oor- 
bonaie  of  lime  in  a  high  temperature. 

The  preference  which  is  given  to  the  Orkney 
kelp,  may»  I  suspect,  be  accounted  for  on  sitnffaor 
principles.     This  species  of  kelp  contains  usttally 

2  cwt.  of  lime  in  every  ton,  produced  from  the  fA- 
eineration  of  the  sea  shells  which  are  entangled  in 
the  weed,  and  this  lime  is  useful  in  decomposing 


on  THE  MANUFACTURE  OF  GLASS.  207 

the  mnriate  of  soda  which  is  always  contained  more 
or  less  in  every  kind  of  kelp. 

The  only  species  of  glass  which  now  remains  lo 
be  described  is  that  of  Plate-glass.  Of  this  there 
are  two  kinds,  viz.  the  one  made  by  blowing  and 
opening,  somewhat  similar  to  the  mode  of  making 
the  spread  window -glass  already  described;  the 
other  is  produced  by  casting  upon  a  table  in  a  way 
something  like  that  of  forming  sheet  lead.  Plate 
glass  of  a  considerable  size  may  be  made  by  the 
first  of  these  methods,  but  the  largest  mirrors  can 
only  be  made  by  casting.  Much  of  the  small  plate 
is  consumed  in  the  navy  and  by  merchant  vessels 
for  glazing  the  cabin-windows,  as  no  other  kind  of 
glass  can  be  depended  upon  in  rough  weather. 

There  are,  I  believe,  only  two  establishinenta 
throughout  the  united  kingdom  for  the  fabrication 
of  plate-glass.  Tlie  first  and  most  considerable  is 
at  Ravenhead  in  Lancashire,  where  the  largest 
plates  in  the  world,  and  inferior  to  no  foreign  plates, 
■re  made,  and  these  are  produced  by  casting.  The 
other  is  at  East  Smithfield,  London,  where  the 
work  is  performed  by  blowing. 

I  express  myself  in  this  decided  manner  respect- 
ing the  work  at  Ravenhead,  in  order  to  counteract 
the  declaration  of  an  eminent  French  manufacturer, 
who  has  thought  proper  to  publish  the  following 
statement! — "All  that  the  English  glass-hooses 
do,  may,"  says  he,  "be  executed,  and  in  fact  Is 
executed,  with   more  facility  in  ours.     But  they 


4 


208  ON  THK  MANUFACTURE  OF  Gi.ASS. 

« 

are  obliged  to  give  up  to  us  the  fabrication  oiplaie* 
glass,  and  of  our  fine  light  glass,  made  with  pure 
saline  fluxes  ^7.** — Those  who  have  seen  the  superb 
collection  of  English  plate-glass  which  is  constantly 
on  show  at  Blackfriars,  will  be  not  a  little  surprised 
at  the  unqualified  nature  of  this  assertion. 

In  the  formation  of  good  plate-glass,  the  first 
consideration  is  that  of  preparing  the  soda,  this  be- 
ing the  species  of  alkali  which  is  usually  employed, 
and,  I  believe,  from  sound  reasoning,  always  pre- 
ferred for  plate-glass.  To  procure  the  soda  for  this 
purpose,  muriate  of  soda  (common  salt)  is  decom- 
posed by  means  of  sub-carbonate  of  potash,  both 
salts  being  in  a  state  of  solution  and  assisted  by 
heat.  After  this,  a  portion  of  the  muriate  of  pot- 
ash is  separated  from  the  solution  by  priority  of  cry- 
stallization, when  the  remaining  alkaline  solution 
is  boiled  to  dryness  and  reserved  for  use.  For« 
merly  kelp-ashes  and  even  weed-ashes  wm«  em- 
ployed, without  any  previous  lixiviation,  in  making 
plate-glass.  Consequently  the  glass  was  then  co- 
loured, and  not  so  brilliant  as  the  modern.  In  the 
great  work  at  St.  Gobain  they  used  nothing  but 
wood-ashes  for  many  years. 

After  the  alkaline  salt  has  been  prepared  as  above, 
it  is  in  some  measure  necessary  to  analyse  it,  with  a 
view  to  ascertain  how  much  real  alkali  is  contained  in 
it,  and  hence  how  much  sand  such  a  salt  will  require. 
When  this  is  known,  the  calculation  is  made  with- 


"  Loysel,  piige  86. 


ON  THE  MANUFACTURE  OF  GLASS.  209 

oat  difficulty;  for  it  has  been  found  that  one  pound 
of  pure  soda  is  sufficient  for  four  pounds  of  sand ; 
and  if  this  quantity  of  sand  be  employed,  a  hard 
compact  glass  will  be  produced  that  cannot  be  in- 
jured by  the  action  of  water,  or  even  any  of  the 
common  mineral  acids.  But  where  so  large  a  pro- 
portion of  silica  is  used,  it  is  necessary  to  employ  a 
heat  not  less  than  1 8,000^  of  Fahrenheit,  it  having 
been  determined  that  silica  is  dissolved  by  alkali  in 
proportion  to  the  height  of  the  temperature  at 
which  the  founding  is  conducted. 

On  the  principle  that  one  pound  of  soda,  free 
from  every  impurity,  will  be  sufficient  for  four 
pounds  of  sand,  then,  if  the  prepared  alkali  should 
eontuiL40  per  cent,  of  real  soda^  which  is  about 
the  usual  quantity,  the  remainder  being  muriate 
of  potash,  carbonic  acid,  and  water,  the  operator 
would  take  160  lbs.,  of  sand  to  every  100  lbs.  of 
such  salt.  Upon  these  data,  therefore,  the  follow- 
ing proportions  of  the  materials  will  produce  a 
class  suitable  for  the  best  plates : — 

'  lb.. 

Lynn  sand,  previously  well  washed  and  dried    .    .  720 

Alkaline  salt  prepared  as  above 450 

Qnick-lime  slacked  and  sifted 80 

Nitre    .    .    .    .  , 25 

CnHet,  or  broken  plate-glass 425 

1700 

These  quantities  of  the  different  materials  are 
Quired  to  produce  one  pot  of  metal;  and  if  the 

VOL,  II.  p 


210  ON  THE  MANUFACTURE  OF  GLASS. 

process  be  well  conducted,  this  will  make  1200  lbs. 
of  good  plate-glass.  This  will,  however,  depehd 
in  Some  measure  on  the  size  of  the  establishment. 
Loysel  has  given  a  detailed  account  of  the  principal 
dimensions  of  the  French  houses  for  making  plate- 
glass,  and  has  introduced  it  by  saying  that  those 
proportions  have  already  served  as  a  model  in  se- 
veral glass-houses,  and  that  experience  has  justified 
his  opinion  of  their  goodness  ^. 

Dr.  Merret  calculates  that  1  cwt.  of  sand  yields 
150  pounds  of  glass^.  This  produce  is,  hbtir- 
ever,  greater  than  can  be  realized,  if  the  founding 
be  properly  conducted. 

The  whitest  sand  which  I  ever  saw  is  found  in 
the  Isle  of  Wight,  at  Alum  Bay,  very  near  the 
Needles.  I  suspect  this  would  make  finer  glass  thaoi 
the  Lynn  sand  above  mentioned.  When  I  was  In 
the  county  of  Hants,  I  inquired  the  price  6f  this 
very  peculiar  sand,  and  found  that  it  is  sold  at  12^. 
per  ton,  delivered  at  Yarmouth  in  the  Isle  of  Wigfat^ 
on  board  the  vessels  which  go  thither  for  it.  The 
importance  of  pure  sand  for  the  manufacture  of 
glass  has  been  acknowledged  for  many  ages.  For 
more  than  a  thousand  years  before  the  commence- 
ment of  the  Christian  era,  the  sand  found  od  the 
shore  of  Belus,  a  river  in  Phoenicia,  wias  reckoned 
the  only  kind  fit  for  making  glass ;  and  even  after 
the  time  of  Christ  it  was  collected,  and  taken  away 


^^  See  his  work  on  Glass,  page  86. 
*•  Observatums  on  Neri,  page  211. 


^I^H         ON  THE  MANUFACTURE  OF  GLASS.  211 

by  vessels  that  came  annually  from  foreign  coun- 
tries, as  Strabo,  Josephus,  Tacitus  and  others 
affirm. 

Lime  is  employed  on  account  of  the  property 
which  it  gives  to  glass,  of  being  a  better  conductor 
of  heat,  and  consequently  rendering  it  less  liable  to 
break  by  sudden  change  of  temperature ;  and  be- 
cause such  glass  cuts  more  readily  by  a  diamond 
than  that  which  is  purely  siliceous.  It  is  important, 
however,  to  use  quick-lime,  and  not  the  carbonate, 
as  the  latter  occasions  so  much  swelling  of  the  ma- 
terials as  to  endanger  their  flowing  over  the  sides 
of  the  crucibles. 

The  quality  of  the  lime  is  of  considerable  im- 
portance. Lime  for  this  purpose  has  sometimes 
been  made  with  stone  brought  as  ballast  from 
Gibraltar,  and  it  answered  better  than  the  chalk 
lime  in  the  neighbourhood  of  London.  I  am  in- 
fortned.  however,  that  the  best  lime  for  the  glass 
bosiness  is  that  of  St.  Vincent's  Rock,  near 
Bristol. 

Nitre  is  very  effectual  towards  depriving  the  ma- 
terials of  every  species  of  carbonaceous  matter ; 
ind  hence  it  improves  the  colour  of  the  glass,  its 
oxygen  uniting  with  the  carbon,  and  forming  with 
it  carbonic  acid  gas,  which  goes  off  in  vapour. 
Nitre  has  also  the  property  of  rendering  glass  more 
transparent. 

Before  we  proceed  further  on  our  subject  I  wisli 
to  inform  my  readers,  that,  for  the  production  of 
the  soda,  the  glass  manufacturer  is  allowed  com- 


212  ON  THE  MANUFACTURE  OF  GLASS. 

men  salt  free  of  duty ;  which  is  a  circumstance  of 
considerable  importance,  especially  as  I  have  rea-' 
son  to  believe  that  there  are  some  glass-makers  in 
the  kingdom  who  are  not  aware  of  the  full  value  of 
their  privilege  in  this  respect.  Every  manuiactiinr 
of  glass  is  entitled  to  this  allowance,  whatever  the 
species  of  glass  may  be  which  he  is  in  the  practice 
of  manufacturing;  I  have  therefore  thought  it 
would  be  rendering  an  acceptable  sendee  to  some 
individuals  to  inform  them  how  they  may  ica* 
dily  decompose  common  salt,  and  also  how  dis* 
pose  of  the  residuum  to  advantage  which  arisci 
from  the  process. 

It  will  be  necessary  in  the  first  place  to  make  an 
entry  of  a  room  for  making  mineral  alkali,  oxflua 
for  glass,  as  it  is  termed  in  the  act  of  parlia* 
ment^;  and  when  due  notice  has  been  given  to 
the  officer  of  excise  who  surveys  in  the  district,  die 
manufacturer  may  commence  the  business.  The 
following  is  the  process  which  has  usually  been 
adopted  by  those  makers  of  glass  who  prepare  their 
own  alkali : — 

Any  quantity  of  common  salt  is  dissolved  in  a 

boiler  of  hot  water,  and  nearly  double  its  w^|;lit 

of  American  or  Russian  pearl-«sh  is  added  to  ife 

This  mixture  will  produce  a  double  decomposition, 

and  two  new  salts  will  be  produced,  viz.  muriate  of 

potash  and  carbonate  of  soda.  I  know  indeed  of 
one  manufactory  where  only  5  cwt.  of  pearUash  is 

«>  See  the  38th  of  Geo.  III.  cap.  89,  |  1 16. 


ON  THE  MANUFACTURE  OF  GLASS.  213 

employed  to  decompose  3  cwt.  of  muriate  of  soda, 
and  I  doubt  not  that  when  the  pearl-ash  is  good 
this  quantity  will  be  sufficient,  because  we  know 
that  t(K)  lbs.  of  pure  subcarbonate  of  potash  are 
equivalent  to  SSlbs.  of  muriate  of  soda. 
•  When  the  liquor  in  which  these  salts  liave  been 
Asaolved  is  concentrated  by  evaporation  to  a  cer- 
tain* point,  which  may  be  easily  known  by  a  little 
csCperience,  the  muriate  of  potash  will  crystallize ; 
and  then  the  remaining  alkaline  liquor  may  be 
fdrther  Evaporated  till  the  carbonate  of  soda  be  re- 
eofered  in  a  dry  state.  The  mineral  alkali  thus 
produced  maybe  used  instead  of  purified  pearl-ash, 
in  the  manufacture  of  the  finest  kinds  of  glass,  and 
the  muriate  of  potash  may  be  sold  for  the  purpose 
of  making  alum,  for  which  it  is  a  very  suitable 
mlU  '  It  is  important  not  to  use  iron  vessels  for 
Ifak  purpose  where  it  can  be  avoided  ;  for,  if  the 
aHnli  be  designed  for  the  superior  kinds  of  glass, 
there  will  be  a  chance  of  its  gaining  colour  froni 
metallic  impregnation. 

An  especial  act  of  parliament  was  passed  so 
ktdy  as  the  year  1813  to  permit  glass-makers  to 
fispose  of  the  muriate  of  potash  obtained  in  this 
way»  on  paying  an  impost  of  20s.  per  ton^i. 

I  conceive  it  might  be  worth  while  for  a  scienti- 
flc  glass^maker  to  institute  a  series  of  experiments 
to  determine  whether  muriate  of  potash  or  muriate 
<rf  soda,  in  their  entire  form,  might  not  be  em- 


61 


See  pages  3  and  9  of  the  Act  already  quoted. 


214  OM  T»E  MANUFACTURE  OF  GLASS.' 

ployed  to  advantage  in  making  some  species  of 
glass.       •  •    > 

It  appears  to  me  that  every  glass-maker  shodU 
prepare  his  own  alkali,  because  he  has  the  exdtt^ 
sive  advantage  of  a  drawback  of  the  whole  of  the 
duty  on  the  salt  employed,  and  he  will  then  have 
a  more  suitable  alkali  for  his  business ;  and  coin 
udering  that  soda  will  saturate  more  silica. tbu 
potash,  the  saving  will  be  very  considerable  on  the 
amount  of  the  alkali  consumed.  * 

Provided  soda  could  be  procured  at  the  samt 
price  as  pearl-ash,  it  would  be  preferable  on  anothtt 
ground,  viz.  that  the  same  degree  of  temperatuM 
will  always  produce  a  more  fluid  metal;  conse* 
quently  this  alkali  ought  exclusively  to  be  used  fof 
making  cast  plate-glass. 

*  The  maker  of  mineral  alkali  for  glass  will  \mn 
a  duty  of  20^.  per  ton  to  pay  on  the  whole  of  ihe 
soda  produced ;  but  as  he  has  the  liberty  of  finislH 
ing  his  process  before  the  duty  becomes  chai]ge* 
able,  he  may  contrive  to  pay  only  upon  the  pvfi 
alkali,  which  will  amount  to  a  very  trifling  im- 
post^. 

■    I-' 

In  resuming  the  relation  of  the  process  of  maldng 
plate-glass,  I  feel  much  difficulty  in  marking  out, 
without  being  tedious,  the  exact  line  of  description, 
80  as  to  render  the  account  in  any  degree  interest^ 
ing ;  for  I  am  aware  that,  were  I  to  enter  into  all 

^  See  38th  of  Geo.  111.  cap.  89,  §  2. 


ON  TH£  MANUFACTURS  OF  GLASS.  21$ 

the  minutis  of  this  business,  the  mere  detail  would 
of  itself  occupy  a  volume.  The  following  circum- 
atances,  however,  which  all  refer  to  the  method 
of  making  plate-glass  by  the  process  of  blowings 
seem  to  deserve  our  attention. 

Id  order  to  acquire  an  idea  of  the  expense  of 
erecting  and  keeping  in  repair  a  furnace  for  making 
plate-glass,  the  reader  may  consult  the  Translator's 
Notes  to  Beckmann*s  History  of  Inventions^.  He 
aays  a  furnace  for  preparing  the  glass  for  casting 
la^  glass  plates,  before  it  is  fit  to  be  set  at  work, 
ooats  3,500  pounds.  A  furnace  for  a  plate-glass- 
wock,  where  the  plates  are  made  by  blowing,  will 
of  course  cost  considerably  less. 

When  the  materials  employed  have  been  suf- 
ficiently comminuted  and  properly  united  by  turning 
fhem  frequently  backwards  and  forwards  upon  a 
floor,  the  crucibles  within  the  furnace  are  carefully 
filled  with  the  mixture,  the  conciator  or  founder 
taking  care  to  have  the  furnace  previously  made  as 
hot  as  possible.  Ten  hours  generally  elapse  before 
these  materials  are  totally  melted  ;  for  during  this 
time  the  pots  are  much  cooled,  and  the  fusion 
checked  by  the  repeated  addition  of  fresh  portions 
of  the  materials. 

*'  The  solvent  power  of  a  saline  flux  upon  silica 
in  a  state  of  fusion,  is  proportioned  to  the  extent 
of  surface  presented  to  its  action  and  the  existing 
force  of  aggregation.     Thus,  if  a  mixture  of  one 

«^  Vol.  ifi.  p.  206.  ed.  1814. 


216  ON  THE  MANUFACTURE  OF  GLASS. 

part  of  fixed  alkali  with  two  of  quartz  reduced  to 
powder,  be  put  into  a  crucible  exposed  for  a  doe 
time  lo  the  heat  of  a  glass-furnace,  the  vitrification 
will  be  complete ;  but  if  the  quartz  be  mixed  m 
lumps  instead  of  powder,  vitrification  will  only  take 
place  on  the  surface  and  in  strata ;  a  portion  of  the 
alkali  will  be  dissipated  by  the  fire,  a  small  quan* 
tity  of  glass  will  be  produced,  and  there  will  remain 
a  great  portion  of  the  quartz  unmelted^." 

The  articles  being  all  melted,  the  next  object  is 
to  refine  the  metal  thoroughly ;  and  this  is  effected 
by  continuing  the  heat  at  its  maximum  for  seveial 
hours  longer,  till  all  the  neutral  salts,  the  aqueons^ 
carbonaceous,  and  gaseous  matters  have  disappeared* 
and  the  glass  is  become  free  from  specks  or  glo- 
bules of  air,  and  destitute  of  colour.  To  describe 
this  state  the  workmen  employ  a  technical  phrase 
and  say  that  the  metal  is  become  piam ;  and  whep 
it  is  announced  that  the  glass  is  quite  plain,  they 
mean  that  it  is  entirely  finished  and  quite  perfect ; 
whereas  in  the  crown-glass-houses  the  metal  at  this 
stage  of  the  preparation  is  said  to  he^ne,  meaning 
that  it  is  refined  or  purified  by  the  dissipation  of 
the  air  bubbles,  &c. 

When  the  contents  of  all  the  crucibles  are  brought 
exactly  to  this  state,  a  workman  goes  into  the  ash- 
pit, or  cave,  as  it  is  called,  and  carefully  closes  up 
the  openings  between  the  bars  of  the  grate  with  a 
composition  consisting  of  clay  and  cut  straw,  to 

^  Loysel  sur  VAri  de  la  Verrerie,  page  18. 


ON  TRE  MANUFACTURE  OF  GLASS.  217 

prevent  the  introduction  of  any  air  into  the  furnace 
through  the  (ire-place,  which  would  endanger  the 
rupture  of  the  pots,  and  produce  too  rapid  a  cool- 
ing of  •  the  furnace.  Some  excellent  directions  for 
the  construction  of  furnaces,  so  as  to  prevent  the 
walls  from  cracking,  are  given  by  Loy&el  in  his* 
work  on  glass^. 

It  is  necessary  in  this  stage  to  secure  every  open- 
ing into  the  furnace ;  because  when  the  metal  has 
hecomeplainy  it  is  not  in  a  fit  state  for  being  worked 
into  plates  of  glass  by  the  process  of  blowing ;  for 
at  this  high  temperature  it  would  be  too  fliiid  to 
ddhere  to  the  irons  when  dipped  into  it,  or  to  pre- 
serve the  shape  which  it  is  necessary  to  give  it  be- 
fore it  can  be  converted  into  a  plane  surface  fit  for 
bring  made  into  mirrors.  It  must  therefore  be 
^dlowed  to  cool  gradually  for  nine  or  ten  hours 
after  every  orifice  has  been  closed,  as  before  men- 
tioned. 

The  temperature  of  the  prepared  metal  being 
diU8  reduced  to  the  working  state,  it  is  modelled 
in  a  manner  very  similar  to  that  of  flint-glass,  al- 
ready described^.  A  workman  dips  an  iron  pipe 
into  the  crucible,  and  having  taken  out  a  little  of 
the  fused  glass  upon  the  point  of  the  iron,  waits  a 
moment  till  that  has  adhered :  he  then  dips  it  in 
•gain  and  rolls  another  portion  round  the  former : 
this  he  repeats,  till  he  finds  he  has  taken  up  enough 


•*  Loysel^  page  5 1 . 

^  See  the  former  part  of  this  Essay,  pages  186,  187. 


218  ON  THE  MANUFACTURE  OF 

for  his  purpose.  Then,  by  blowing  down  the  irc» 
tube,  he  expands  the  mass  of  glass  a  little,  and  pnOf 
duces  a  hoUowness  within  it :  this  he  enlarges  by 
repeated  blowings  till  it  forms  a  globe  of  12  or  14 
inches  in  diameter,  or  more,  according  to  the  size 
of  the  intended  glass-plate. 

At  St.  Gobin  it  is  usual  to  sprinkle  with  water 
the  first  portion  of  metal  that  .is  taken  up  on  the 
point  of  the  iron,  in  order  to  make  it  adhere  better 
to  the  instrument,  and  thus  be  able  to  support  a 
greater  weight  of  glass  in  the  subsequent  immer- 
sions in  the  crucible. 

The  next  object,  in  this  stqge  of  the  process,  i| 
to  convert  the  globe  into  a  cylinder.  This  the  work- 
man effects  by  giving  the  rod  to  which  the  soft  glfUf 
is  attached,  the  motion  of  a  pendulum.  It  is  theq 
heated  afresh  at  the  mouth  of  the  fumape,  and  a 
hole  is  punched  in  the  centre  of  that  end  of  the 
cylinder  which  is  furthest  off  the  working  rod.  This 
IS  done  with  an  iron  chisel  and  mallet ;  and  as  the 
glass  is  previously  softened  by  heat,  there  is  no  dan- 
-ger  in  the  operation.  The  orifice  which  has  beeQ 
thus  made  is  afterwards  widened  by  an  instrument 
kept  for  the  purpose ;  and  then,  a  pair  of  shears 
being  introduced,  a  slit  is  made  in  the  cylinder  of 
glass  extending  to  one  half  of  its  length. 

It  being  necessary,  however,  that  the  cylindrical 
form  should  for  the  present  be  preserved,  another 
workman  applies  a  temporary  rib  of  glass,  which  has 
been  previously  attached  to  a  working  rod,  across 
that  end  of  the  cylinder  which  has  thus  been  cut 


ON  THE  MANUFACTURE  OF  GLASS. 


21!) 


open.  This  inatrument,  whicli  is  called  a  pontif, 
is  not  hollow  like  the  blowing  irons,  but  is  merely 
s  metallic  rod  about  6  feet  long.  In  France  the 
pontil  for  making  plate-glass  has  a  bar  of  iron 
across  the  end  of  it,  forming  a  T,  and  the  rib  of 
glasv  designed  to  be  attached  to  the  cylinder  is  put 
witbin  B  sht  in  the  edge  of  the  cross  bar,  which  is 
designed  for  that  purpose. 

When  this  is  done,  the  other  rod  is  detached,  in 
order  to  allow  of  that  end  of  the  cylinder  being  also 
heated,  opened,  and  slit  up  with  shears  as  before 
practised.  The  whole  of  the  cylinder  being  thus 
divided,  the  pontil  is  detached  from  it,  and  the  glass 
is  carried  to  the  spreading  oven,  where  it  is  laid 
upon  an  elevated  floor  covered  with  a  thick  stratum 
of  sand,  to  prevent  the  adhesion  of  the  glass  In  its 
fioftened  state.  In  a  few  minutes  it  is  pushed  on 
to  an  adjoining  apartment,  where  it  is  quickly  placed 
in  a  Vertical  poiiltion  to  anneal,  ^o  much  care  ia 
necessary  in  this  business,  and  the  work  is  so  labo- 
rious, that  one  man  seldom  makes  more  than  10 
or  12  plates  in  the  course  of  24  hours. 

The  annealing  kiln  or  oven  having  been  thus 
filled  with  the  plates  of  glass,  each  standing  on  its 
edge,  the  doors  and  the  chimney  are  closed  and 
carefully  luted  with  clay,  to  prevent  the  possibility 
of  any  cold  air  entering  the  chamber  for  the  space 
of  twelve  or  fourteen  days  ;  after  which  the  lutings 
ore  gradually  loosened,  and  the  glass  is  removed 
into  an  open  part  of  the  glass-house  to  attain  by 
i  the  temperature  of  the  surrounding  atmo- 


220  ON  THE  MANUFACTURE  OF  GLASS. 

sphere.  •  When  an  hour  or  two  has  elapsed^  these 
plates  may  be  carried  with  safety  to  the  cutting- 
room,  and  there  they  are  trimmed  round  the  edges 
with  a  diamond,  and  by  other  means,  to  prepare 
them  for  the  operation  of  grinding.  According  to 
Pliny,  the  ancients  used  diamond  powder  for  polish- 
ing the  precious  stones :  but  Beckmann  says  thit 
the  first  mention  of  a  diamond  being  used  for 
writing  on  ^/a^.9  occurs  in  the  sixteenth  century. 
Francis  I.  of  France  wrote  the  following  lines  wiih 
his  diamond  ring  upon  a  pane  of  glass,  to  let  the 
duchess  of  Estampes  know  that  he  was  jealous : 

''  Souvent  femme  vane, 
Mai  habil  qui  8*y  fie.** 

The  ancients  must  however  have  been  acquainted 
with  our  method  of  grinding  glass,  for  Pliny  speaks 
of  its  being  turned  by  the  wheel  and  engraved  on 
like  silver^. 

To  describe  all .  the  preparations  and  conve- 
niences of  the  grinding  apartment  in  an  English 
plate-glass-house,  together  with  the  varied  pro- 
cesses of  rubbing  down  the  plates  to  one  uniform 
thickness,  would  extend  this  Essay  beyond  its  pre- 
scribed bounds  :  but  an  outline  of  this  part  of  the 
business  must  be  given.  And  with  regard  to  the 
uniformity  of  thickness,  this  is  necessary  not  only 
for  mirrors  but  for  the  navy,  where  the  superin- 
tendants  are  very  circumspect  in  having  the  glass 
all  of  the  defined  thickness.     There  is  an  o£Bicer  at 

•7  Lib.  xxxvi.  §  26. 


ON  THE  MANUFACTUKE  OF  GLASS. 


221 


each  of  His  Majesty's  dock-yards  who  is  provided 
with  a  gauge  to  measure  it,  and  whose  duty  it  is 
to  reject  all  those  squares  that  do  not  correspond  to 
the  fixed  rule.  Tlie  size  which  is  most  commonly 
used  is  of  the  thickness  of  3-l6ths  of  an  inch. 

In  the  grinding  apartment  the  glass  plates  de- 
signed for  mirrors  or  other  purposes,  to  which  plate- 
glass  is  applied,  are  imbi.'dded  in  plaster  of  Paris 
upon  a  suitable  table  or  bench,  care  being  first  taken 
to  fix  them  perfectly  horizontal.  When  the  table 
is  thus  Blled,  other  plates  are  attached  by  plaster  of 
Paris  to  another  plane  surface ;  and  these  being 
suspended  over  the  lower  table,  are  made  to  traverse 
bya  regular  motion  upon  the  surface  of  the  former. 
This  is  effected  by  means  of  a  power  obtained  from 
a  steam-engine;  and  when  the  upper  set  of  plates 
are  thus  set  in  motion,  the  attendant  casts  a  certain 
quantity  of  sand  and  occasionally  a  little  water  be- 
tween the  two  surfaces:  it  may  therefore  easily  be 
conceived  that,  by  continuing  this  motion  with 
repeated  additions  of  sand  and  water,  both  surfaces 
will  be  abraded  and  ground  down  to  any  thickness 
that  the  operator  may  require.  When  these  plates 
are  properly  ground  by  a  succession  of  sands  of 
different  degrees  of  fineness,  which  are  all  distin- 
guished by  well-known  numbers  in  the  same  way 
as  the  sportsman  distinguishes  his  leaden  shot,  the 
plates  are  detached  from  the  plaster  of  Paris;  and 
having  been  turned  so  as  to  present  the  other  side, 
they  are  reset  in  the  plaster,  and  the  same  opera- 
tiona  are  rep< 


222  ON  TH£  MANUFACTURE  OF  GLA89. 

There  is  a  process  which  precedes  this,  called 
ruffing^  and  other  manrpulations,  before  this  biisi* 
ness  of  grinding  is  finished.  But  these  are  so  vt* 
Tied  and  moltiplied  that  it  is  impossible  to  describe 
them  without  more  prolixity  dian  I  am  willing  to 
impose  upon  my  readers ;  and  even  then  the  manu- 
factory must  be  visited  before  I  could  be  thoroughly 
understood^. 

'  It  may,  nevertheless,  be  noticed,  that  the  process 
of  grinding  reduces  every  hundred  weight  of  rough 
plates,  independently  of  breakage,  to  less  than  half 
B' hundred,  and  that  the  glass  which  is  ground  off 
is  deemed  unfit  for  any  other  purpose  of  glassy 
making^  except  that  of  black  bottles,  because  it  is 
mixed  with  so  large  a  portion  of  common  rivet 
sand.  It  has  therefore  generally  been  either  sold 
at  a  very  low  rate  for  scouring  pewter,  &c«  or  en* 
tirely  thrown  away :  and  I  remember  having  cal* 
tnklated  some  years  ago,  on  the  supposition  of  from 
dne-faalf  to  two-thirds  of  the  glass  being  abraded, 
that  the  loss  of  real  glass  at  the  London  plate-house 
cannot  be  less  than  two  tons  per  week,  and  the  sAnd 
exfpended  will  weekly  amount  to  at  least  sixteen  or 
twenty  tons. 

'    A  method  has  however  been  contrived  of  satdng 
the'  whole  of  this  refuse,  and  preserving  it  in  a  state 

^"  These  operations  are  conducted  differently  in  France^  as 
may  be  seen  by  consulting  Eneychp.  ou  Diet,  Universel,  Supp, 
tome  ri.  page  647 — 654. 

^  It  is  the  large  quantity  of  iron  that  is  contained  in  river 
sand  which  renders  Ms  ground  glass  so  unfit  for  being  formed 
again  into  plate-glass. 


ON  THE  MANUFACTURE  OF  GLASS.  223 

fit  for  being  again  formed  into  any  of  the  best 
species  of  glass.  It  consists  in  grinding  the  plates 
mtkh  pure  flinty  instead  of  the  liver-sand  hitherto 
employed ;  therefore,  when  the  flints  have  been 
ground  so  as  to  have  no  admixture  of  iron  with 
them,  this  residuum  is  very  fit  for  the  purpose  above 
mentioned,  and  the  glass  contained  in  it  may  be 
^estimated  at  more  value  than  an  equal  weight  of 
pure  cQllet70.  In  the  operation  of  grinding  the 
plates,  three  or  four  tons  of  prepared  flints  are 
e^ual  in  effect  to  20  tons  of  sand ;  the  work  is  done 
in  much  less  time ;  and  the  abraded  matter,  instead 
of  being  a  cumbrous  and  useless  mass,  is  actually 
an  estimable  residuum,  admirably  adapted  to  the 
purposes  of  the  manufactory,  and  capable  of  yield- 
ing considerable  profit7i. 

In  resuming  the  subject,  I  have  only  to  add,  that 
when  the  grinding  is  finished,  the  next  process  is 
that  of  smoothing^  which  may  indeed  be  considered 
to  be  a  continuation  of  the  grinding  process  ;  but 
this  is  performed  by  the  hand,  and  with  emery  of 
diflkrent  fineness,  instead  of  sand. 

Emery  is  imported  in  very  hard  solid  lumps; 
these  are  ground  by  a  powerful  mill,  and  then  sifted. 
TTie  finer  parts  which  pass  though  the  sieve  are  se- 


^  CuUet  is  a  technical  term  for  old  broken  glass. 

7>  A  patent  has  been  taken  out  for  this  method  of  grinding 
plate-glass.  It  is  dated  9  th  of  August  1813,  and  the  specifi- 
cstioii  18  printed  in  the  25  th  volume  of  the  Repertory  of  Arts, 
Second  Series,  page  134. 


224  ON  THE  MANUFACTURE  OF  GLA38. 

patated .  into  portions  of  different  degrees  of  fine- 
ness, by  a  peculiar  apparatus  constructed  for  the 
purpose;  but  the  effect  is  produced  by  a  prooest 
somewhat  similar  to  that  of  eluirtation^  an  operar 
tion  well  known  to  chemists. 

Emery,  which  is  used  for  polishing  metals  as  well 
as  glass,  is  a  native  substance  consisting  of  iron, 
alumina,  and  silica.  It  is  brought  from  diffeitat 
parts  of  the  continent,  but  it  is  found  no  where  in 
such  abundance  as  in  the  mountains  on  the  western 
coast  of  the  Island  of  Naxia,  the  most  fertile  of  all 
the  islands  in  the  Archipelago.  It  occurs  so  pleor 
tifully  there,  that  the  adjoining  cape  has  acquired 
the  name  of  Cape  Emery  72.  According  to  Mr. 
Boyle,  its  specific  gravity  is  400.  From  the  analy; 
sis  of  Mr.  Smithson  Tennant,  emery  is  composed  of 
80  parts  of  alumina,  3  silica,  and  4  iron  73.  Ine 
emery  which  is  used  in  making  scouring  paper  has 
lately  been  much  adulterated  by  the  admixture  of  old 
bottle  glass,  which  is  ground  fine  for  the  purpose. 
The  common  sand-paper  is  covered  with  a  mixture 
of  this  ground  glass  and  sharp  sand. 

The  last  operation  is  that  ol  polishing.  This  is 
done  with  colcothar  of  vitriol^  and  is  a  process  of 
only  a  few  hours.  The  plates  are  then  well  washed, 
and  squared  by  a  diamond  for  sale.  Such  are  die 
processes  by  which  that  kind  of  plate-glass  is  made 
which  is  produced  by  blowing. 


'^  See  Bu8ching*8  Geography,  vol.  ii.  page  154. 
^3  Fhiloiophical  Transactions  for  1802,  page  400. 


ON  THE  MANUFACTURE  OF  GLASS. 


225 


Idttle  can  be  known  of  those  manufuctories  where 
large  mirrors  are  made  by  casting,  as  the  proprie- 
tors have  always  conducted  their  works  with  the  ut- 
most caution  and  secrecy.  There  are,  indeed,  only 
two  establishments  of  the  kind  that  I  know  of;  the 
one  at  the  Castle  of  St.  Gobin  in  the  forest  of  Fere, 
in  tlie  department  of  the  Aisne,  in  France,  as  before 
ineotioned,  and  the  other  at  Ilavenhead  near  St. 
Helens,  in  the  county  of  Lancaster.  The  build- 
ings at  St.  Gobin  are  so  various  and  extended,  that 
tliey  are  said  to  resemble  a  large  town  more  tlian  a. 
single  manufactory  74.  Tliey  make  plate>glass  in 
France  likewise  by  the  process  of  blowing,  similar 
to  that  of  our  manufactory  at  East  Smilhfield.  One 
of  these  establishments  is  at  Tour-la-Ville  near 
Cherbourg,  formed  in  the  year  1 665  under  the  pa- 
tronage of  Colbert  during  his  administration,  and 
designated  by  the  name  and  style  of  "The  manu- 
factory for  blown  mirror-glasa." 

The  manufactory  at  Ravenliead  was  established 
about  the  year  1771  or  177'')  and  the  proprietors 
were  incorporated  by  an  Act  of  Parliament  of  the 
13tb  of  Geo.  III.  cap.  38,  by  the  name  and  style 
of  The  Governor  aad  Company  of  the  Sritish 
Cast-plate  Manufacturerx,  with  certain  privileges 
and  immunities  which  are  accurately  defined  in  the 
Act. 

From  this  period  a  very  considerable  trade  was 
carried  on  by  tliia  corporate  body  till  the  year  1794, 


226  ON  THE  MAKUFACTURE  OF  GLASS. 

wh^  the  Gimpany  was  *'  compelled  to  sell  thdr 
property  for  payment  of  their  debts.**  These  gie 
the  words  of  the  Act  of  the  38th  Geo*  III.  cap.  )7* 
by  which  it  also  appears  that  the  joint  capital 
amounted  to  60,000/.  and  the  money  borrowed  to 
67,535/.  The  estabKshment  was  afterwards  par* 
chased  for  the  benefit  of  several  persons  who  cairied 
on  the  manufactory  under  the  Act,  until  its  expin- 
tion,  and  afterwards  as  a  private  company  until -the 
year  1798;  when  a  new  Company,  consisting  of  ei(^* 
teen  most  respectable  individuals,  was  incorpocated 
by  an  Act  of  the  38th  of  His  late  Majesty,  entitled 
^*  AnAct  to  incorporate  certain  persons  for  the  pnr^ 
pose  of  continuing  a  manufactory  of  plate*{^aas.* 
This  Act  bears  date  the  7th  May,  1798^  to  oontinpe 
for  the  term  of  2 1  years,  and  from  thence  until  di^ 
end  of  the  then  next  session  of  parliament.  Tbe- 
capital  stock  to  be  one  hundred  thousand  ponndi^ 
and  divided  into  shares  of  one  hundred  pounds 
each. 

In  consequence  of  the  secrecy  which  has  always 
been  observed  in  the  conduct  of  this  manu&ctoiy, 
a  detail  of  the  various  manipulations  lor  the  fonna- 
tion  of  cast  plate-glass  could  hardly  beexpected.  But 
since  the  first  edition  of  these  Eissays  went  to  pres^ 
I  have  been  fortunate  enough  to  be  allowed  to  gs 
through  the  whole  of  these  very  extensive  works 
and  to  examine  the  various  operations  usually  car- 
ried on  there,  and  which  I  was  allowed  to  see  in 
consequence  of  my  having  taken  the  precautioq  to 
procure  a  letter  of  introduction  from  the  Committee 


OK  THE  MANUFACTURE  OF  GLASS.  22/ 

in  London,  without  which  I  understood  the  resident 
Managers  would  not  have  been  justified  in  admitting 


The  first  thing  the  attendant  showed.  me»  was 
the  operation  of  grinding  the  plates,  which  is  a  con- 
cern of  great  magnitude.  Those  plates  which  are 
derigned  for  mirrors  and  other  purposes  where  the 
sorfiace  must  be  perfectly  true,  are  firmly  imbedded, 
m  m  horizontal  position,  upon  a  wooden  table  or 
phtfonn,  and  these  are  made  to  revolve  one  upon 
the  other  by  strong  mechanical  powerobtained  from 
a  ateam  engine,  and  by  these  means  they  grind 
OM- another;  sand  and  water  being  occasionally 
thtown  in  between  them,  and  afterwards  emery  and 
water  in  a  way  very  similar  to  the  method  already 
dcrcribed  at  page  22 1  when  treating  on  the  manufac- 
tvre  of  plate-glass  by  blowina;.  It  is  observable 
that  the  plates  of  glass  are  ground  in  pairs,  and  to 
see  80  many  of  these  of  several  feet  diameter  in 
one  room,  moving  in  all  directions  by  means  of 
machinery  and  with  considerable  velocity,  asto- 
nished me  not  a  little. 

When  by  this  method  the  plates  are  ground  to 
one  uniform  thickness,  they  are  detached  from  the 
beds  of  plaster  and  removed  to  the  polishing  room. 
Here  the  process  is  performed  by  an  article  called 
eolcoihar  of  vitriol y  which  is  merely  sulphate  of 
iron  first  calcined  to  redness  and  then  reduced  to 
an  impalpable  powder.  This  colcothar  is  spread 
upon  a  piece  of  hat-felt,  which  is  attached  to  a  very 
singular  kind  of  machine  kept  in  constant  motion 

tt2 


S28       an  the  mawutactuke  of  glam. 

%y  means  of  a  powder  oommunicated  by  the  steam 

The  last  process  of  polishing  is  performed  by  ^ 
4iand.  This  is  managed  by  women,  who  Inverse 
TMie  plate  of  glasa  over  the  aor&oe  of  another,  ^with 
great  velocity  and  adroitness.  The:article  wlucb  is 
-used  in  this  finishing  process  is  called  iutiy.  it  is 
4he  white  oxide  <if  tin  finely  levigated.  Ttm  woifc 
being  completed,  the  plates  are  well  washed  milk 
water,  and  then  taken  to  the  cutting-room,  vAmat 
they  aresqnared  for  sale,  as  described  at  page  224. 

When  I  had  examined  these  processes,  the  f;oide 
conducted  me  to  the  Foundry,  whidi  is  the  graat 
Yoom  containing  the  melting  furnaces,  the  taUelbr 
casting,  and  the  annealing  ovens.  The  buildkig 
containing  aU  these  is  very  lofty,  and  by  fiv  the 
largest  room  under  one  roof,  that  has  ever  yet  been 
^erected  in  Great  Britain.  It  is  339  feet  long,  and 
155  feet  in  width. 

The  furnace  for  founding  the  metal  and  the  ovens 
for  heating  the  crucibles,  occupy  a  very  long  range 
in  the  middle  of  this  immense  room :  they  stand  ia 
a  longitudinal  direction,  and  fill  up  about  one  third 
of  the  whole  area. 

The  method  of  heating  the  furnace  is  very  impor- 
tant ;  but  as  I  was  not  at  the  manufactory  vidien  this 
operation  was  performed,  I  am  unwilling  to  at- 
tempt to  describe  it.  The  mode  adopted  at  the 
Castle  of  St  Gobin  is,  however,  too  curious  for  a  de- 
scription of  it  to  be  omitted.  Two  persons  stripped 
to  their  shirts  run  round    tlie    furnace   without 


ON  THE  MANUFACTURE  OF  GLASS. 


229 


making  the  least  stop,  and  with  a  speed  equal  to 
seven  leagues  in  six  hours :  as  they  go  along  thejr 
take  up  two  small  billets  of  wood,  of  about  1^  or  2 
inchea  in  diameter,  which  are  cut  for  the  purpose ; 
these  tbey  throw  into  the  first  opening,  and  continu- 
ing their  course  do  the  same  at  the  second,  and  at 
every  other  opening  into  the  furnace.  This  circuit 
they  continue  without  interruption  for  six  hours  suc- 
cessively, and  then  are  relieved  by  others  who  con- 
tinue the  same  course  till  the  glass  is  completely  fi- 
nished. It  has  been  thought  surprising  that  the  fre- 
quent application  of  two  such  small  parcels  of 
wood,  and  which  are  consumed  in  an  instant^ 
should  keep  the  furnace  to  the  proper  degree  ol 
heat,  which  is  such  that  a  large  bar  of  iron  laid  at  one 
of  the  mouths  of  the  furnace,  becomes  red-hot  in 
less  than  half  a  minute '7^. 

At  Ravenhead  a  row  of  aDoealing  ovens  stands 
on  each  side  of  the  foundry,  occupying  the  greatest 
part  of  the  side  walla  of  the  building.  These  are 
each  16  feet  wide  and  forty  feet  deep.  The  ar- 
niDgement  of  these  ovens  is  such  that  the  plates 
of  glass  cau  be  deposited  in  them  immediately  as 
tbey  are  cast,  in  order  that  tlit-y  tnay  cool  as  gradu- 
ally as  possible  ;  and  the  floor  of  each  is  contrived 
to  be  oD  an  exact  level  with  the  casting  table,  for  the 
more  easy  removal  of  the  platestnto  them.  When 
each  oven  has  received  its  destined  quantity,  it  is 


*'  Supplfinfitl  lo  Iht  Frmch  Enci/tlnpmlut,  tome  vi 
1776,  |Nige  62>i.     R«n'&  Cj/isloptdia,  Artide  ti/iui. 


330  ON  THE  MANUFACTURE  6t  GLA98. 

shut  up  by  an  iron  door,  and  this  is  secured  all 
round  with  mortar  to  prevent  any  access  of  atmo- 
^heric  air.  The  plate  glass  remains  in  these  avmm 
about  a  fortnight,  when  it  is  taken  out,  and  removed 
to  the  store-room.  This  process  of  annealing  Is 
one  of  the  most  important  in  the  whole  manufiw- 
tbry.  If  it  were  neglected,  the  plates  of  glass  wodU 
be  liable  to  crack  at  every  change  of  temperatnie; 

The  most  curious  part  of  this  business,  howevtr, 
is  the  process  of  casting  the  plate*glass,  which  is 
conducted  somewhat  in  the  following  manner  »— - 
When  the  metal  has  been  properly  prepared  and 
has  become  completely  refined  and  settled,  it  ir 
laded  into  smaller  crucibles  called  cisterns^  wbidi 
stand  in  the  same  furnace.  In  these  vesseb  it  re- 
mains some  hours  longer,  or  until  they  beeoroe  of 
a  white  heat  throughout,  which  is  one  of  the  fint 
criterions  by  which  the  workmen  judge  of  its  fitness 
for  being  formed  into  plates.  When  the  glasa  has 
acquired  that  exact  degree  of  temperature  which  has 
been  found  by  experience  to  be  best  suited 'for  its 
flowing  properly  under  the  roller,  the  crucible  canh 
taining  the  fluid  nietal  is  taken  out  of  the  fumabeby 
means  of  a  crane  and  placed  upon  a  low  carriage 
for  the  conveniency  of  moving  it  to  the  casting  taUe, 
which  is  aometimes  a  considerable  distance  from 
the  melting  furnace. 

When  the  crucible  of  hot  metal  is  brought  near 
the  table,  it  is  raised  by  a  crane  with  a  pair  of  galK* 
pers  a  few  feet  from  the  ground,  to  give  the  work- 
men an  opportunity  of  scraping  the  scoria  from  the 


ON  THE  MANUFACTURE  OF  CLASS. 


231 


bottom  and  outer  sides  of  the  crucible,  which  other- 
wbe  might  drop  off,  and  spoil  the  beauty  of  the 
plates.  The  pot  of  glass  is  then  let  down  to  the 
ground  and  the  scum  is  very  carefully  taken  off;  it 
is  then  wound  up  again  by  means  of  the  crane,  and 
when  at  a  sufficient  height,  is  gently  swung  over 
the  upper  end  of  the  casting  table,  where  it  is  drawn 
on  one  side,  and  by  a  peculiar  contrivance  for  throw- 
ing the  crucible  into  an  inclined  position,  n  torrent 
of  melted  glass  is  suddenly  poured  out  on  the  smooth 
iron  surface  beneath  it.  The  crucible  ii  no  sooner 
emptied  of  the  metal,  all  of  an  intense  red-heat, 
than  the  iron  roller  is  set  in  motion,  and  by  this 
massive  instrument  the  whole  of  the  glass  is  spread 
out  into  one  single  sheet  of  a  great  size,  and  of  an 
uniform  thickness  ;  the  thickness  of  the  plate  being 
determined  by  ribs  of  brass  which  ate  hxed  one  on 
each  side  of  the  casting  table,  and  upon  which  the 
iron  roller  runs.  The  length  of  each  plate  is  how- 
ever in  some  measure  determined  by  the  quantity 
of  metal  which  the  crucible  happens  to  contain  ; 
and  if  it  should  have  held  more  than  was  absolute- 
ly necessary  for  covering  the  surface  of  the  table, 
the  rxtra  quantity  falls  into  a  vessel  of  water  and 
is  employed  in  the  next  operation. 

The  spectacle  of  such  a  vast  body  of  melted  glasn 
poured  at  once  from  an  immense  crucible  on  a  me- 
tallic table  of  great  magnitude,  is  truly  grand  ;  and 
the  variety  of  colours  which  the  plate  exhibits  im- 
mediately after  the  roller  has  passed  over  it,  renders 
this  an  operation  far  more  hplendid  and  interesting 


L 


282  ON  THE  MANUFACTUAB  OF  GLAitf^ 

than  can  possibly  be  described.  Indeed  tbe  cfiect 
wbiob  it  produces  is  quite  inconceivable  to  aaeh  as 
have  not  been  eye-mtnesses  of  the  roanipulatioiit  m 
this  surprising  establishment. 

Notwithstanding  the  immense  scale  upon  wUdi 
the  manu&ctorj  in  Lancashire  is  established,  it  ap- 
pears to  me^  that  it  dififers  from  the  one  in  London 
more  in  the  circumstance  of  the  plates  being  aui, 
than  in  the  composition  of  the  glass  itaelf. 

From  information  which  I  have  received  by  vari- 
ous channels,  I  apprehend  the  founding  the  DMtal 
is  tlie  same  at  both  places ;  but  that  at  Ravenhead, 
when  the  metal  is  made  ready  it  b  removed  into 
other  receptacles  called  cisterns,  as  already  mention* 
ed,  and  so  contrived  that  they  may  be  readily  boitled 
out  of  the  furnace  when  every  thing  is  in  a  state  of 
preparation,  and  the  fluid  body  poured  from  them 
at  once^  and  as  quickly  as  possible,  upon  the  tidile^ 
where  the  plate  of  glass  is  ultimately  formed. 

This  table  formerly  consisted  of  one  massive  plate 
of  copper  twelve  feet  long  and  of  a  proportionate 
width,  ground  and  polished  so  as  to  present  throuj^ 
out  an  uniformly  smooth  sur&ce.  It  was  soon 
found,  however,  that  copper  is  an  improper  metal 
for  the  purpose,  it  being  liable  to  crack  from  the 
sudden  transition  of  the  heat  from  the  torrent  of 
melted  glass  poured  upon  it. 

Several  copper  tables  having  been  thus  rendend 
useless,  and  a  vast  expense  incurred  in  substituting 
one  new  copper  table  after  another,  the  managen 
at  length  came  to  the  determination  of  trying  iron. 


ON  THE  MANUFACTURE  OF  GLASS. 


233 


mid  ticcordingly  a  cast-iron  table  of  great  tliickness 
was  forthwith  prepared  for  the  purpose.  This  im- 
mense mass  of  iron  weighed  so  many  tons  that  il 
was  necessary  to  build  a  peculiar  kind  of  csrriiige 
to  transport  it,  and  the  other  expenses  of  convey- 
ing it  from  the  iron  foundry  to  the  glass  works 
were  enormous.  This  tab!*;,  like  the  former  ones 
of  copper,  was  fixed  upon  a  suitable  frame,  and  this 
is  supported  by  casters,  for  the  convenience  of 
moving  the  table  from  the  mouth  of  one  annealing 
oven  to  another. 

^Vhether  il  must  be  attributed  to  the  extra  thick- 
ness of  this  metallic  table  or  to  any  other  cause,  it 
maybe  difficult  to  determine;  but  this  certainly 
answered  the  intended  purpose,  and  appears  to  have 
sustained  no  injury  whatever  from  the  frequent  and 
8udden  accessions  of  heat  to  which  it  has  been  ex- 
posed. When  I  saw  it,  it  had  been  in  constant 
use  for  some  years,  and  I  was  told  that  the  propri- 
etors thought  il  would  last  for  any  length  of  time 
that  they  could  possibly  require  it. 

It  should  have  been  remarked,  that  as  soon  as 
tliese  plates  have  become  fixed  by  cooling,  they  are 
thrust  by  main  strength  oft'  the  table  and  gradually 
slipped  into  the  annealing  oven  immediately  con- 
tiguous, and  there  they  are  treated  like  the  smaller 
plates  already  described,  excepting  in  one  circum- 
stance, that  of  their  being  spread  out,  one  by  one, 
in  a  horizontal  jwsition,  instead  of  being  piled  on 
their  edges,  as  they  usually  have  been  in  those 
works  where  plate-glass  is  made  by  blowing. 


234  OM  THX  ICANUFACTUKB  OF  GLASf  • 

The  reader  may  conoeive  the  advaotage  whidi 
must  result  from  this  arrangementy  when  the^  vast 
size  of  these  plates  is  considered.  The  method  6i 
blomog  answers  extremely  well  for  small  ptatea^  or 
for  plates  which  do  not  exceed  4  feet  in  length  and 
2  feet  3  in  breadth ;  but  when  laiger,  they  have  not 
a  sufficient  thickness  to  bear  the  grinding^  and 
besides,  no  man  could  have  strength  sufficient  to 
wield  in  his  arms  that  quantity  of  glass  whidi  is 
required  to  form  such  immense  plates  as  are  made 
at  Ravenhead. 

.  How  very  advantageous  it  is  to  the  Company  to 
sell  large  plates,  may  be  seen  in  the  following  taUe, 
which  I  have  formed  from  a  tariff  of  the  prices  of 
the  different  sized  polished  plates  of  glass,  which 
was  published  and  sold  by  the  bookseUers  in  1704» 
in  a  small  volume  of  100  pages.  The  first  column 
contidns  the  number  of  square  feet  in  each  plal^ 
and  the  opposite  ones  their  respective  prices^  un* 
silvered. 

Feet.                                              £,  t.  d. 

6 4  00 

12 14  5  0 

20 36  14  0 

SO  . 74  11  0 

42 156  12  0 

48 225  10  0 

54 306  4  0 

60 395  0  0 

The  proprietors  of  this  establishment  announce 
however,  by  public  advertisement,  that  they  have 
constandy  on  sale  at  their  warehouse,  Blackfriars 


OM  THE  MANUFACTURE  OF  GLABS.  285 

BrU^  London,  glass*plates  of  the  enormous  size 
of  six  feet  by  twelve  feet  each. 
•  Thftt  one  plate  should  contain  more  than  seventy 
iqoafe  feet  of  glass,  and  yet  have  a  surfttce  perfectly 
tme,  is  really  astonishing ;  and  when  we  consider 
that  there  is  only  one  establishment  in  the  world 
fimt  can  at  all  compare  with  the  works  at  Raven- 
bead,  we  need  not  hesitate  in  pronouncing  the  latter 
to  be  the  most  curious  and  interesting  manufactory 
in  the  British  empire. 

In  concluding  the  account  of  the  manufacture  of 
plate-glass,  it  must  be  noticed  that  the  great  ex- 
penses necessarily  attendant  upon  the  making  of 
cast  plates  have  obliged  some  of  the  artists  in  France 
to  return  to  the  old  method  of  blowing ;  and  some 
have  been  so  fortunate  in  improving  this  branch  of 
nannfacture,  that  plates  are  now  formed  in  that 
eountry,  by  blowing,  which  are  64  Flemish  inches 
in  height  and  23  in  breadth,  (in  English  measure 
60  inches  by  21^  inches,)  a  size  which  it  had  been 
impossible  to  attain  before,  except  by  the  process 
of  casting.  The  mass  of  matter  necessary  for  this 
purpose,  weighing  more  than  a  hundred  pounds,  is 
by  the  workman  blown  into  the  shape  of  a  large 
beg ;  it  is  then  reduced  to  the  form  of  a  cylinder, 
and,  being  cut  up,  is  by  stretching,  rolling  with  a 
smooth  iron,  and  other  means  not  yet  known  but 
to  those  employed  in  the  art,  transformed  into  an 
even  plane7<5. 

I 

^  Bcckinann*8  Hutary  of  Inventions,  vol.  iii*  page  207. 


236    cm  XB£  MANUrACTURR  OP  GUkM. 

Hanng  thus  briefly  described  the  modes,  ef 
making  the  five  different  species  of  glass,  it  mi^  be 
proper  to  advert  to  a  recent  discovery  in  the  srtt 
and  then  to  say  a  £eir  words  on  the  properliea  of 
giass  itsdf. 

The  Ascovery  to  wlucb  I  refer  is  thai  oi  ^mn 
incrustations^  for  which  a  patent  has  been  obtained 
mider  the  name  of  CrysiaUo'Cermmie,  by  Mesiia» 
Peilatt  and  Green  of  St.  PkuFs  Chureh'yafdy  Loo* 
don  77,  In  describing  this  el^nt  and  ingenioiii 
manufiftctory,  I  cannot  do  better  than  avail  mysdf 
of  Mr.  Pellatt*s  own  memoir  on  the  snbject 

The  ancients  were  not  altogether  ignorant  of  tins 
art ;  but  their  incrustations  were  very  imperfect  is 
consequence  of  their  not  being  in  possession  of  a 
substance  for  forming  the  device  or  figure  to  be 
inserted  within  the  body  of  the  glass,  that  waa  less 
fusible  than  the  glass  itself. 

About  forty  years  ago,  a  man  u&ctnier  in  Bohemia 
attempted  to  incrust  m  glass  small  figures  sadc 
with  a  peculiar  kind  of  clay ;  but  bis  experiments 
were  in  but  few  instances  successful,  in  consequence 
of  the  day  not  being  adapted  to  adhere  prc^perly  to 
the  glass.  It  was,  however,  firom  the  Bohemian 
that  the  idea  was  caught  by  some  French  raann- 
focturers,  who,  after  having  expended  a  considerable 
sum  in  the  attempt,  at  length  succeeded  in  inenisl- 
ing  several  medallions  of  Buonajmrte,  which  were 

^  See  a  Memoir  on  the  Origin,  Progreu  and  Improvemeniof 
GloMt  Manufactures :  includi$tg  an  jiccount  of  the  tatent  €rf' 
staHo^Cermiie,  mr  Glass  Incrusta^ons.  QnsrUs  Loadoo  1821. 


ON  THE  MANUFACTUHE  OF  GLASS.  23? 

BoM  at  an  enormous  price.  From  the  extreme 
dtfliculty  of  making  these  medallions,  and  their 
almost  invariably  breaking,  very  few  were  finished; 
and  I  understand  that  the  French  have  since  then 
contented  themselves  with  confining  the  art  to  the 
decoration  of  small  trinkets,  &£. 

A  patent  has,  however,  as  before  mentioned, 
been  recently  taken  out  in  this  country  for  making 
these  ornamental  incrustations  ;  and  if  we  may 
judge  from  the  manner  of  their  execution,  they 
promise  to  produce  a  new  era  in  the  art  of  glass- 
making.  By  this  process,  ornaments  of  any 
description,  heraldic  crests,  or  portraits  of  any  vari- 
ety of  colour,  may  be  introduced  into  tlie  glass,  so 
as  to  become  perfectly  imperishable.  It  mnst  be 
understood  that  the  substance  of  which  these  devices 
are  composed  is  less  fusible  than  glass,  incapable  of 
generating  air,  and  at  the  same  time  susceptible  of 
contraction  or  expansion,  as,  in  the  course  of  manu- 
facture, the  glass  becomes  hot  or  cold.  Tlie  orna- 
mental figures  are  introduced  into  the  body  of  the 
glass  U'hi/e  hot,  by  which  means  they  become 
actually  incorporated  with  it. 

The  composition  used  in  the  patent  incnistations, 
and  which  does  great  credit  to  tlie  taste  and  che- 
mical acquirements  of  Messrs.  Pellatt  and  Green, 
is  of  a  silvery  appearance,  which  has  a  very  superb 
effect  when  introduced  into  richly  cut  glass.  And 
as  miniatures  and  other  paintings  may  be  enamelled 
upon  it,  without  the  colours  losing  any  of  their 
brilliancy,  it  may  be  adapted  to  any  purpose  that 
the  taste  or  judgement  of  the  artist  may  suggest. 


238         ON  THE  MANUFACTURE  OF  GLASS. 

A  most  important  advantage  to  be  derived  from 
this  etegant  invention,  respects  the  preservation  of 
dates  and  inscriptions.  Casts  of  medals  and  coins 
present  no  equal  securi^  for  perpetuating  them. 
Had  this  art  been  known  to  the  ancients,  it  would 
have  preserved  to  us  many  interesting  memorials. 
The  inscription,  when  once  incnisted  in  a  solid 
block  of  crystal,  like  the  fly  in  amber,  will  eSee^ 
tually  resist  for  ages  the  destructive  action  of  the 
atmosphere. 

In  reverting  to  the  nature  of  glass  as  a  chemical 
compound,  it  may  be  said  that  glass  possesses  se* 
veral  distinct  and  very  remarkable  properties  which 
may  be  enumerated  in  the  following  order.  It  is 
transparent  and  elastic,  it  possesses  strong  elecbical 
powers,  is  ductile  and  fusible  by  heat,  becomes 
very  brittle  by  sudden  change  of  t<^mperature,  and 
is  imperishable  in  the  fire.  Dr.  Merret  has  enu- 
merated no  less  than  26  distinct  properties  which 
glass  possesses,  some  of  which  were  new  to  me  and 
curious  78. 

It  is  the  ductility  of  glass  which  qualifies  it  for 
being  fashioned  into  such  numerous  shapes  and 
employed  for  such  a  variety  of  purposes.  Dr. 
Merret  says,  that  when  James  Howell  was  at  Ve- 
nice he  saw  a  complete  galley,  with  all  her  masts, 
sails,  cables,  tackling,  poop,  forecastle,  anchon, 
and  her  long  boat,  all  made  in  glass  79,     Cardan 

^  See  page  214  of  his  Translation  of  NerVs  Art  of  GUm, 
^  Translation  of  Neri  on  Glass,  page  314. 


OM  THE  MANUFACTURB  OF  GLASS.  239 

idates  that  he  saw  a  cart  with  two  oxen  in  it,  made 
m&kf^aM,  and  yet  small  enough  to  be  covered  with 
the  wing  of  a  fly  ^. 

The  transparency  of  ^lass  is  not  a  little  sar« 
piiang,  when  we  consider  that  it  is  formed  of  sub- 
slanoea  which  in  themselves  are  perfectly  opake. 

It  was  the  transparency  of  glass  which  occa* 
sioned  it  to  be  so  much  esteemed  by  the  ancients. 
The  emperor  Nero  paid  6000  sestertia,  nearly  equal 
to  50,000/.  sterling,  for  two  small  transparent  glass 
Clips  with  handles  8  ^  Glass  not  transparent  was 
then  in  common  use  for  various  domestic  utensils, 
ako  a  red  coloured  opake  glass  called  vitrum  hama' 
iimon,  probably  from  lutmatitis  the  blood  stone  ^. 
Some  of  the  windows  in  the  ancient  city  of  Pom- 
pdi  were  glazed  with  a  thick  sort  of  glass^  but  this 
was  only  semi*transparent^.  Martial,  however, 
mentions  glass  in  such  a  manner  as  shows  it  to 
have  been  common  in  his  time  for  drinking  vessels, 
and  also  of  so  transparent  a  texture  as  to  admit  an 
accurate  examination  of  the  liquor  contained  in 
Aem84. 

''  No6  bibimus  vitro,  tu  mjrrha  Pontice :  quare  ? 
Prodat  perspicuus  ne  duo  vina  calix  *\** 

There  must,  indeed,  have  been  a  considerable 

^  De  Farietate,  lib.  x.  cap.  52.    •^  Pliny,  lib.  xxxvi.  cap.  26. 

•  Pliny,  lib.  xxxvi.  cap.  67. 

**  Miss  Starke*s  Letters  from  Italy, 

^  On  the  knowledge  of  the  ancients  respecting  glass,  see 
Dr.  Falconer  in  the  Memoirs  of  the  Literary  and  PhUosopkkal 
Sodetw  of  Manchester,  vol.  ii.  page  95—105. 

••  Mart.  Epig.  iv.  86. 


240  cm  TB£  MAMUFACni RE  OF  4»«Afl8« 

Dumber  of  makers  of  g}«BS,  in  ancient  Roine^  lor 
we  jread  of  their  faanng  a  district  near  tbe  Appian 
gate  assigned  them  for  carr3ring  on  the  nmxmbf^ 
tory.  Tlie  elasticity  of  glass  naay  be  proved  by  a 
pane  of  common  window^glass,  which  may  be  bent 
out  of  a  straight  line  and  yet  will  retncn  ngain  to 
its  place  without  being  fcactured ;  and  if  glass  be 
run  out  very  fine  like  a  thread,  it  may  be  leaded 
round  the  finger  without  breaking. 

One  of  the  most  elastic  of  aU  known  bodies  i$ 
glasa.  If  it  be  drawn  into  fioe  strings,  it  may  be 
)ient  into  a  complete  circle,  and  held  in  that  poai*' 
Xion  for  any  length  of  time  without  impairiag  ito 
elastacity ;  for  the  moment  the  pressure  is  tewsmci 
it  recovers  its  form,  and  beccmies  a  straight  rod  as 
before. 

A  few  years  ago  a  person  travelled  thron^^  most 
(of  the  counties  of  England  to  exhibit  the  spinning 
pf  glass.  He  would  spin  many  hundred  yards  of 
it,  jand  as  fine  as  silk,  in  a  minute. 

In  consequence  of  the  ready  excitability  of  glass 
by  friction,  and  its  impermeability  to  electricity^  St 
is  the  only  material  which  is  now  made  use  of  for 
the  construction  of  electrical  cylinders. 

Unannealed  glass  possesses  some  very  singular 
properties.  Vessels  of  capacity  made  with  sudi 
glass  will  often  bear  a  considerable  Uow  from  tvith- 
out,  and  yet  be  shivered  to  pieces  by  the  smallest 
fragment  of  stone,  even  less  than  a  pea,  if  dropped 
in  the  inside ;  and  the  thicker  the  bottom  the  more 
easily  will  the  effect  be  produced.     Cups  pf  green 


ON  THE  MANUFACTURE  OF  OLA88.  241 

g^asSy  some  of  them  three  inches  thick  at  bottom, 
fend  which  had  borne  the  shock  of  a  musket  ball 
dropped  from  a  considerable  height,  were  shivered 
into  fragments  by  letting  a  bit  of  flint  weighing  only 
two  grains  drop  into  them  ^. 

The  brittleness  which  glass  acquires  by  sudden 
dMUUge  of  temperature,  and  its  indestructibility  in 
the  fire,  are  properties  which  alone  might  furnish 
inatter  for  many  interesting  obser?ations,  and  much 
curious  speculation,  to  one  who  would  undertake  to 
write  entirely  on  this  subject ;  but  the  size  to  which 
Ham  essay  has  already  attained  will  oblige  me  to 
pMS  on  to  enumerate  some  of  the  principal  desi** 
dnata  in  glass-making,  preparatory  to  a  few  de- 
sultory hints  which  I  propose  to  ofier,  and  which 
I  presume  may  be  worthy  of  the  consideration  of 
ill  who  are  engaged  in  this  important  though  at 
tltt  same  time  hazardous  undertaking. 

Tke  most  obvious  desiderata  in  the  manufacture 
of  glass  appear  to  me  to  be  the  following,  viz. 

Riiat.  To  discover  an  easy  and  eflectual  method 
of  exBfnining  the  different  kinds  of  clay,  and.de* 
termining  which  is  most  suitable  for  the  manufac- 
ture of  the  furnaces  and  crucibles. 

Seoandly.  To  ascertain  the  best  form  of  the 
wious  sized  pots  or  crucibles,  as  well  as  the  thick- 
neao  required  in  each  according  to  its  magnitude, 
bm  supporting  the  pressure  of  the  melted  glass  at 

tbr  di&rent  varieties  of  temperature. 

— -  -  ^^^-~^^~^ 

*  See  the  Philosophical  Transactions,  Nos.  475,  509,  &  5 15, 
and  the  Dlibtin  Literary  Journal,  8vo.  1746,  vol.  iii.  page  154. 

VOL.  II.  R 


242  ON  THE  MANUFACTURE  OF  GLASS. 

Thirdly.  To  devise  a  better  and  more  certain 
mode  of  moulding  the  crucibles,  so  that  they  shall 
not  be  liable  to  burst  during  the  formation  of  the 
glass. 

Fourthly.  To  prepare  glass  by  some  method 
which  shall  dissipate  the  gaseous  products  com- 
pletely, and  at  the  same  time  unite  the  maternb 
more  uniformly  and  with  greater  certainty  than  has 
ever  yet  been  done  by  any  of  the  modes  already 
practised. 

Fifthly.  To  make  glass  with  the  muriates  of 
potash  and  soda,  without  the  previous  decoa^posi'* 
tion  of  these  salts,  and  of  as  good  quality  aa  that 
which  is  made  with  the  carbonates,  sulphates,  and 
sulphurets  of  those  alkalies. 

Sixthly.  To  discover  some  preparation  of  pit 
coal,  or  other  combustible  materials,  which  shall 
produce  as  great  a  degree  of  heat  and  flame  in  the 
furnaces  as  wood,  and  yet  be  as  fit  in  every  other 
respect  for  making  glass. 

Seventhly.  To  anneal  glass  more  effectually  and 
with  greater  certainty  than  can  be  done  by  the 
methods  usually  adopted  for  that  purpose. 

Eighthly.  To  devise  some  new  mode  of  charging 
the  duty  on  glass  fairly  and  bond,  fide  on  such  glass 
only  as  shall  be  saleable,  so  as  to  relieve  the  manu- 
facturer from  the  interference  of  excise  officers, 
during  the  time  of  operation,  and  which  shall  leave 
him  at  full  liberty  to  melt  and  remelt  the  materials, 
to  make  experiments,  or  to  institute  new  processes 
whenever  he  may  see  occasion,  without  his  render- 


ON  THE  MANUFACTURE  OF  GLASS.  243 

ing  himself  liable  to  the  operation  of  any  penal 
statute. 

On  these  several  desiderata,  the  following  obser- 
vations present  themselves. 

It  has  been  determined  by  Loysel  that  an  argil- 
laceous earth  which  contains  at  least  95  per  cent. 
of  quartz  and  alumina,  and  less  than  5  per  cent. 
of  carbonate  of  lime  and  oxides,  may  be  employed 
in  most  of  the  small  white  glass  works,  where  the 
fire  is  not  very  intense ;  but  that  the  proportion  of 
alumina  and  quartz  ought  to  be  97  in  each  100 
pounds  when  it  is  to  be  employed  in  the  great  fur- 
naces for  plate  and  bottle  glass,  especially  for  the 
Cabrieation  of  the  crucibles  ^. 

The  same  writer  states,  that  the  materials  of 
which  these  are  made  ought  to  be  infusible  in  the 
d^ree  of  heat  which  is  necessary  to  be  employed ; 
not  susceptible  of  corrosion  by  the  action  of  the 
mixtures  in  fusion,  and  capable  of  taking  and  pre- 
serving those  forms  which  are  found  to  be  most 
suitable  for  these  constructions  ^8.  The  best  di- 
rections that  have  ever  been  given  on  the  necessary 
thickness  of  the  crucibles  are  to  be  seen  in  the 
same  work  ^.  Some  experiments  on  this  subject 
having  been  made  by  him,  he  formed  a  valuable 
table  for  the  use  of  the  manufacturers  of  glass,  to 
show  the  respective  thickness  of  the  crucibles  of  va- 
rious diameters,  all  which  are  estimated  according 


^  Loysel,  Essai  sur  VArt  de  la  Verrerie,  page  16. 
••  Ibid,  page  5.  •*  Ibid,  page  58. 

k2 


244  ON  THE  MANUFACTURE  OF  OLAS9. 

to  tha  different  degrees  of  the  tenacity  of  the  nui« 
terialsdo. 

In  addition  to  the  various  remarks  which  I  have 
made  on  the  construction  of  the  crucibles,  I  am 
desirous  of  annexing  the  following  important  ob- 
servations. 

'^Pottery/*  says  Loysel,  "is  one  of  the  moot 
difficult  and  delicate  parts  of  the  ari  of  gla$8-* 
making,  and  merits  the  strictest  attention.  If  the 
pottery  is  perfect,  the  artist  has  the  power  to  ma- 
nage the  action  of  the  heat,  to  vary  at  pleasures  the 
vitrifiable  compositions,  to  regulate  the  meltings 
the  refining,  and  the  whole  works.  He  knows  be^ 
forehand  the  products  of  his  fabrication,  and  A' 
rects  it  to  his  greatest  advantage.  If  on  the  con- 
tra the  pottery  is  bad,  all  is  confusion.  The 
fiiT^  co^t  of  the  materiids^  their  preparationj^  ao4 
the  expense  of  the  workmanship,  turn  to  entWf 
loss,  and  the  ruin  of  the  proprietor  is  inevitable. 
No  expense  therefore,  or  care,  ought  to  be  spared 
to  procure  good  pottery  9\" 

The  Ekiglish  glass-makers  labour  under  an  in- 
convenience which  is  not  felt  in  France  and  some 
other  countries  on  the  Continent  of  Europe.  ^ 
consequence  of  their  heating  their  furnaces  with 
pit  coal  they  are  under  the  necessity  of  making  their 
best  flint  glass  in  covered  pots ;  and  as  the  heat  is 
much  lower  in  the  interior  of  a  covered  crucible 
than  in  an  open  one,  we  are  obliged  to  make  our 


^  Loysel,  Essai  sur  I* Art  de  la  Verrerie,  page  269. 
«|  Ibtd.  page  57. 


ON  THE  MANUFACTURE  OF  GLASS. 


245 


gHss  of  more  fusible  materials;  and  consequently, 
byuiiing  a  large  portion  of  lead,  and  less  silica,  we 
produce  a  softer  glass  than  is  prepared  by  those  who 
have  an  abundance  of  wood  fuel. 

It  appears  to  me  tliat  there  can  be  no  certainty 
in  the  process  of  annealing  without  the  use  of  a 
pyrometer;  and  as  the  glass  manufacturers  have 
frequently  to  make  experiments  on  clays,  have  not 
such  persons  excellent  opportunities  of  contriving 
Buch  an  instrument  as  would  suit  not  only  this  pur- 
pose, but  serve  for  the  large  furnace  also  ?  Glass 
made  with  alkali  and  silica  only,  is  more  difficult 
to  anneal  with  certainty  than  such  as  contains  lime 
and  lead  in  its  composition. 

It  was  formerly  a  common  notion  that  soda  was 
belter  calculated  for  making  glass  than  potash:  but 
of  late  years  this  appears  to  have  been  doubted ;  for 
many  eminent  glass-makers  now  say  that  they  can 
make  as  good  glass  with  potash  as  soda.  The  an- 
cients made  use  of  soda  for  the  formation  of  glass. 
The  mixture  of  sand  and  soda,  before  it  became 
perfect  glass,  wrs  called  ainmonUrum.  I  am,  how> 
ever,  of  opinion  that  snda  is  pn-ferable  for  glass, 
inasmuch  as  it  requires  more  silica  for  its  satura- 
tion than  potash ;  and  it  will  not  be  denied  that 
the  greater  the  quantity  of  the  siliceous  earth  which 
can  be  made  to  enter  into  the  composition  of  glass, 
the  harder  will  that  glass  be,  and  the  less  liable  to 
be  injured  by  abrasion.  This  extra  power  of  satu- 
ration holds  good  also  with  the  acids,  for  100 
parts  of  soda  combine  with  \7'i  parts  of  dry  nitric 


246  ON  THE  MANUFACTURE  OF  GLASS. 

acid,  128  parts  of  solid  sulphuric  acid,  or  88  paits 
of  dry  muriatic  acid ;  whereas  potash  takes  up  only 
1 14  parts  of  nitric,  84  of  sulphuric,  or  68  parts  of 
muriatic  acid. 

In  making  glass,  "  if  the  combination  be  such 
that  in  1000  parts  there  remain  only  200  or  evefl 
only  150  parts  of  alkali,  the  glass  is  hard,  clear, 
brilliant  and  transparent,  and  approaches  the  beauty 
of  rock  crystal.  The  excellence  of  flint  glass  is  in 
direct  ratio  to  the  quantity  of  silica,  and  in  inverse 
ratio  of  the  quantity  of  alkali  Q^." 

Moreover,  soda,  as  was  before  mentioned,  will 
make  a  more  fluid  metal,  and  thus  the  manu&G- 
turer  will  at  all  times  be  more  likely  to  separate  all 
the  sandiver,  for  this  rises  with  more  difficulty  to 
the  surface  when  the  glass  is  made  with  potash ;  and 
it  is  well  known  that,  wherever  any  of  the  sandiver 
or  glass-gall  remains  in  the  finished  glass,  it  will 
occasion  striae,  clouds  or  bubbles,  either  of  which 
very  much  lessen  its  value. 

When  plate-glass  is  to  be  made  with  potash,  it 
is  generally  thought  requisite  to  add  some  borax  to 
the  composition  to  render  the  metal  more  fluid, 
otherwise  it  is  apt  to  stiffen  before  the  plates  can 
be  completely  formed.  This  is  another  objection 
to  the  use  of  potash  for  this  particular  species  of 
glass.  On  these  accounts  it  is  of  importance  al- 
ways to  use  soda  for  plate-glass,  and  also  for  such 
flint  glass  as  is  intended  to  be  employed  for  par- 

^  Loysel^  Essai  sur  VAri  de  la  Verrerie,  page  113. 


ON  THE  MANUFACTURE  OF  GLASS.  247 

tieular  purposes ;  especially  for  such  articles  as  are 
equired  to  sustain  much  wear. 

It  13  however  generally  imagined  that  potash  will 
make  the  whitest  glass,  though  such  glass  is  more 
apt  to  be  seedy,  as  the  workmen  call  it,  that  is,  to 
be  full  of  very  loinute  specks,  which  greatly  impair 
its  beauty,  and  diminish  its  value. 

A  friend  of  mine  in  the  glass  trade  lias  however 
assured  me  tliat  he  never  could  make  flint  glass, 
even  with  the  purest  soda,  so  perfectly  white  as  he 
could  with  pearl-ash,  though  he  repeated  the  ex- 
periment many  times  and  with  every  precaution. 

Since  then  I  have  had  an  opportunity  of  ex- 
amining several  specimens  of  flint  glass  made  with 
soda  and  others  with  potash  ;  and  I  am  now  inclined 
to  think  that  very  brilliant  flint  glass,  perfectly  pel- 
lucid and  colourless,  cannot  be  niiide  with  soda, 
but  that  potash  is  absolutely  necessary  for  this  par- 
ticular species  of  glass.  Tlie  potash  ought  how- 
ever to  undergo  a  complete  purification  from  all 
neutral  salts,  before  it  be  employed  for  wine  glasses 
or  for  any  kind  of  ornamental  flint  glass. 

It  may  in  some  cases  be  safer  to  use  soda,  be- 
cause, where  tow  much  alkali  has  been  employed, 
such  glass  will  be  less  likely  to  be  injured  by  ex- 
posure to  the  atmosphere  in  damp  situations  than 
glass  made  with  the  vegetable  alkali,  which  is  al- 
ways liable  to  deliquescence.  I  am,  perhaps,  jus- 
tified in  this  observation  by  a  remark  of  Dr.  Mer- 
rit,  in  his  examination  of  Neri's  Art  of  Gloss. 
"lu  old  windows  of  French  glass,  in  that  part," 


246  ON  THE  MANUFACTURE  OF  GLASS. 

says  he,  *^  which  lies  towards  the  air,  you  may  dis- 
cern pieces  of  salt ;  and  in  the  finest  glass,  where 
there  is  a  great  proportion  of  salt  to  the  sand,  you 
shall  find  that  such  glasses  standing  long  in  sub- 
terraneous places,  will  fall  to  pieces,  the  union  of 
the  salt  and  sand  decaying.**  Fourcroy  also  says, 
that  gla^s  made  with  soda  is  best  for  holding  the 
mineral  acids,  as  such  glass  is  decomposed  with 
more  difficulty  by  acids  than  such  as  is  made  with 
potash  93. 

Borrichius  relates,  that  he  saw  several  glass  la- 
cry  matories  dug  up  at  Rome  which  had  Isdn  in  the. 
ground  several  hundred  years,  and  that  the  glass 
was  split  into  an  infinite  number  of  lamina  like 
the  Muscovy  talc,  and  yet  these  laminae  were 
smooth  and  transparent  9^.  This  effect  was  pro- 
bably occasioned  by  the  use  of  potash  in  the  glass, 
and  the  emplo}rment  of  too  large  a  quantity  of  that 
alkali. 

I  would  not, ,  however,  in  these  remarks  be  mis- 
understood ;  for  it  is  impossible  to  be  sure  of  having 
perfect  glass  unless  an  extra  quantity  of  alkali  be 
employed :  but  then  care  must  be  taken  to  prolong 
the  process  till  the  whole  of  this  excess  be  sepa- 
rated from  the  mass  and  volatilized. 

Shaw  has  a  remark  to  the  same  purpose.  **  In 
order,**  says  he,  "  to  give  our  glass  the  desired  de- 
gree of  hardness,  it  is  proper  to  continue  it  long  in 
the  fire,  which  is  constantly  found  to  add  strength 

y^  Fourcroy's  System  of  Chemistry,  vol.  ii.  page  387. 
^  Borrichius  de  Ortu  et  Progressu  Chemicp. 


ON  THE  MANUFACTURE  OF  GUkSS.  240 

and  hardness  to  glass.  Common  glass,  by  being 
constantly  kept  in  a  strong  fusion  for  a  month  or 
six  weeks,  has  become  of  a  stony  hardness,  ap- 
proaching to  the  native  hardness  of  the  flint  or  sand 
employed  in  its  preparation  9^.^ 

I  am  rather  surprised  that  sulphate  of  soda  has 
not  been  more  employed  in  this  manufacture ;  be- 
cause, if  this  salt  be  fused  with  plenty  of  carbona- 
ceous matter,  it  will  soon  be  converted  to  a  sul- 
phuret ;  and  when  in  this  state,  the  heat  of  the 
furnace,  combined  with  the  affinity  which  the  al- 
kali has  for  the  silica,  would  separate  the  sulphur 
entirely,  and  leave  the  alkali  as  capable  of  com- 
bining with  the  siliceous  matter  as  if  it  had  origi* 
nally  been  pure  soda. 

It  is  necessary  to  remark  that  in  this  case  an 
abundance  of  charcoal  must  be  used,  because,  if 
any  undecom posed  sulphate  of  potash  or  sulphate 
of  soda  be  left  in  the  glass,  it  will  form  what  are 
called  salt-blisters. 

In  like  manner^  I  apprehend,  American  potash 
might  possibly  be  employed  instead  of  pearlash ; 
for,  though  more  contaminated  with  sulphur,  this 
would  be  separated  by  the  heat  of  the  glass-house 
furnace,  and  the  result  would  be  advantageous; 
inasmuch  as  potash  is  usually  cheaper  than  pearl- 
ash,  and  yet  contains  more  alkali.  There  can, 
however,  be  no  doubt  that  potash  would  do  equally 
well  for  decomposing  common  salt,  because  much 
of  its  impurity  would  be  separated  in  that  opera- 


*»*  Shaw's  Chemical  Lectures,  page  427.  ^-^  " 


/-■  ■■■-\ 


250  ON  THE  MANUFACTURE  OF  Gl^ASS; 

tion,  and  the  remainder  would  be  got  rid  of  in  the 
process  of  fritting  the  glass. 

I  have  also  to  recommend  that  frequent  attention 
be  paid  to  the  price  of  salt-petre,  because  I  am  per*- 
suaded  that  whenever  this  article  is  at  a  low  r«te 
it  must  be  advisable  to  employ  it  for  flint  and 
crown  glass  in  preference  to  American  pearlash; 
inasmuch  as  it  contains  a  large  portion  of  alkrii, 
and  is  free  from  those  neutral  salts  with  which  pot- 
and  pearl-ash  of  every  kind  are  contaminated. 
Where  metallic  oxides  have  been  employed  to  co* 
lour  glass,  either  for  windows  or  for  the  imitation 
of  the  precious  stones,  nitre  is  found  to  be  of  great 
use,  as  it  tends  to  preserve  the  metallic  oiddes  in  a 
high  state  of  oxidizement,  and  thus  imparts  great 
vivacity  to  the  colours.  Nitre  is  composed  of  47 
per  cent,  pure  potash  and  53  per  cent,  of  diy  ni* 
trie  acid. 

Agricola  knew  the  value  of  nitre  in  making  glass. 
"  The  first  place,"  says  he,  '*  must  be  given  to  aaU* 
petre,  the  second  to  fossil  salt  96.** 

It  has  been  said  that  borax  (subborate  of  soda) 
will  make  a  harder  glass  than  either  of  the  pure  al- 
kalies. Borax  consists  of  34  parts  of  boracic  acid, 
17  parts  of  soda,  and  49  parts  of  water  9'7. 

This  saline  substance  was  known  to  the  ancient 
Romans.  We  read  of  the  Circus  in  the  time  of 
one  of  the  early  Caesars  being  covered  with  vermi- 
lion and  borax  9^.     Whether  borax  or  itfictU  couW 


^  Agricola  De  Re  Metallica,  ^  Bergman. 

^  Suetonius  in  Vita  Caligula,  §  18. 


ON  THE  MANUFACTURE  OF  GLASS.  251 

be  procured  in  quantity  cheap  enough  to  be  em- 
ployed in  glass-making,  I  know  not.  Dr.  Shaw 
relates,  that  with  four  ounces  of  borax  and  one 
ounce  of  fine  white  sand  he  formed  a  pure  glass, 
which  was  so  hard  that  it  cut  common  glass  like 
the  diamond  99. 

It  would  be  advantageous,  I  conceive,  if  some 
method  could  be  devised  of  frequently  stirring  the 
fluid  metal  in  the  crucibles,  so  as  always  to  ensure 
the  production  of  glass  that  shall  have  a  perfectly 
homogeneous  character.  In  a  former  part  of  this 
Essay  I  have  mentioned  the  circumstance  of  veins 
Orstrise  appearing  in  flint  glass.  These  might  ge- 
DeraUy  be  prevented' by  the  adoption  of  the  expe- 
ffient  which  is  now  suggested,  because  they  arise 
horn  the  want  of  due  uniformity  in  the  mixture  of 
the  compound  mass.  Mr.  Keir,  the  translator  of 
Macquer's  Chemical  Dictionary ^  and  who  was  him- 
self formerly  engaged  in  the  manufacture  of  glass 
H  Stourbridge,  says,  ^*  The  reason  why  flint  glass  is 
more  subject  to  veins  than  any  other  glass  is,  be* 
eanse  it  is  composed  of  materials  of  more  different 
densities  >«>.- 

Loysel  has  shown  that  the  various  specific  gravi- 
ties of  the  different  comjK)unds  which  are  formed, 
lodi  as  those  with  alkali  and  silica ;  alkali  and 
elay ;  and,  lastly,  alkali  with  the  metallic  oxides ; 
ire  fully  sufficient  to  account  for  the  production  of 

^  Shaw's  Chemical  Lectures,  page  426. 
»«>  See  his  note  in  vol.  iii.  of  the  Dictionary^  under  the  article 
Vitryication. 


SfiS  ON  THE  MANUFACTURE  OF  GLASS* 

these  imperfections,  and  that  nothing  but  a  mort 
uniform  mixture  of  the  different  materials,  toge« 
ther  with  complete  fusion,  can  prevent  their  ap 
pearance. 

'*  Glass  made  at  a  great  degree  of  heat  will 
always  be  lighter  than  that  made  at  a  lower  tempe* 
rature.  The  first  contains  more  silica  and  less 
alkali,  whereas  the  specific  gravity  of  glass  Bug* 
ments  according  to  the  greater  quantity  of  b\U& 
that  is  combined  with  it/*  *^  Glass  made  to  coit* 
tain  8U  silica  and  20  alkali  will  have  a  specific  gra* 
vity  of  2.36,  whereas  that  which  is  composed  of  54 
silica  and  46  alkali  will  be  2.54.*'  loi  Might  it  not 
be  advisable  for  the  proprietor  of  every  glass-house 
to  take  the  specific  gravity  of  each  pot  of  metal 
when  finished  ?  as  this  would  always  be  a  guide  to 
show  whether  the  workmen  had  observed  due  care 
in  keeping  the  furnace  at  a  proper  degree  of  teili* 
perature. 

In  treating  this  subject,  Loysel  remarks,  tbit 
*'  glass  made  with  silica  and  the  fixed  alkalies  has 
a  specific  gravity  of  2.3  to  2.4 ;  that  formed  with 
alkali  and  clay  2.5  ;  that  with  alkali  and  chalk  2^7 
to  2.8  ;  the  oxide  of  manganese  if  vitrified  by  itsdf 
3.2  or  3.3 ;  while  the  glass  made  with  oxide  of  leMl 
will  be  7.2  to  73  of  specific  gravity."  When  thmt 
different  kinds  of  vitrified  products  occur  in  the 
same  crucible,  and  a  complete  mixture  of  them  baa 


»<*'  Loysel,  Essai  sur  tJrt  de  la  Verrcrie,  page  207. 


ON  THE  MANUFACTURE  OF  GLASS.  25^ 

not  been  effected,  it  is  not  surprising^  he  observes, 
tbmt  the  glass  should  be  imperfect  ^^. 

The  art  of  making  glass  seems  to  depend  upon 
the  successful  or  perfect  union  of  two  or  more  me- 
tallic oxides  which  have  an  affinity  for  each  other. 
On  tbi^  principle  it  is  that  potash,  an  oxide  of  pot- 
Matum,  and  silica,  the  oxide  of  silicium,  are  fused 
together  and  form  glass.  One  part  of  silica  and 
two  parts  of  borate  of  soda  unite  and  form  a  trans- 
parent colourless  glass.  One  part  of  silica  and 
three  of  oxide  of  lead  form  good  green  glass,  and 
it  18  well  known  at  all  the  iron  furnaces  Uxat  si- 
licat  when  united  to  the  oxide  of  iron,  produces 
a  perfect  black  glass  of  extreme  hardness  and 
durability. 

I  have  only  one  observation  more,  viz.  that  the 
proprietors  of  the  respective  manufactories  we  have 
been  describing,  ought,  in  the  construction  of  the 
furnaces  and  the  fabrication  of  the  crucibles,  to 
wave  all  considerations  of  economy  in  the  expendi- 
tare^  because  no  sacrifice  can  be  too  great  to  obtain 
such  as  will  constantly  sustain  a  very  elevated 
temperature  without  injury.  It  has  been  already 
shown  '<^,  that  where  glass  is  to  be  made  with  the 
least  possible  quantity  of  alkali,  a  high  degree  of 
heat  must  be  employed,  and  it  is  indeed  on  this  cir- 
cumstance that  the  economy  of  glass-making  seems 
chiefly  to  depend. 


«•»  Essai  sur  VArt  de  la  Verrerie,  Loysel^  page  183. 
'^  See  an  observation  on  temperature^  page  209. 


254  ON  THE  BIANUFACTURE  OF  GLASS. 

The  principal  Acts  of  Parliament  now  in  force 
respecting  the  manufacture  and  sale  of  glass,  ace 
as  follow — viz.  19th  Geo.  II.  cbi^.  12;  17th  Geo. 
III.  chap.  39;  24th  Geo.  III.  chap.  4 1 ;  35th  Geo. 
m.  chap.  114;  38th  Geo.  III.  chap.  33;  38th  Geo. 
m.  chap.  89 ;  and  the  43d  Geo.  III.  chap.  69. 
In  the  53d  Geo  III.  an  Act  passed,  intitled  "  An 
Act  for  allowing  glass  makers  to  dispose  of  the 
muriate  of  potash  arising  in  the  manufacture  of 
flux  for  glass,  and  for  charging  a  duty  of  excise  of 
20^.  per  ton  thereon,  to  take  date  from  the  5th  day 
of  July,  1813." 


ESSAY   XII. 


ON 


BLEACHING. 


ESSAY  XII. 


ON 


BLE  AC  KING. 


riiAX  and  hemp  were  employed  in  the  fabri- 
caUon  of  cloth  many  ages  ago^  and  in  those  early 
times  such  cloth  was  highly  esteemed  ;  it  must 
therefore  long  before  that  period  have  been  dis- 
covered that  these  fabrics  were  improved  in  colour 
by  exposure  to  the  action  of  the  atmosphere.  The 
eflfect  of  hot  water  in  whitening  brown  linen  would 
also  soon  arrest  the  attention  of  mankind;  and 
when  it  became  a  practice  with  the  early  inhabitants 
of  Asia  to  employ  certain  earths  and  alkaline  plants 
in  the  operations  of  washing  and  scouring  their  gar- 
ments^, the  whitening,  as  well  as  the  detersive  pro- 
perties of  these  vegetables,  could  not  fail  to  be 
observed,  and,  by  degrees,  would  naturally  occasion 
the  introduction  of  regular  processes  for  bleaching; 
and  that  this  art  was  practised  very  early,  is,  I  think, 

»  See  Essay  IV.  vol.  i.  p.  242. 

•  See  Goguet's  Origin  of  Laws,  8^c.,  vol.  i.  p.  132. 

VOL.    II.  S 


258  ON   BLEACHING. 

evident  from  the  great  progress  which  it  had  made 
in  the  beginning  of  the  Christian  era^. 

That  the  ancients  had  learnt  some  method  of 
rendering  their  linen  extremely  white,  may  be  sup- 
posed from  many  remarks  which  are  interspersed 
among  their  writings.  Homer  speaks  of  the  gar« 
ments  of  his  countrywomen  in  a  way  that  leaves  no 
doubt  of  their  being  clothed^  occasionally  at  least, 
in  fvhiie  vestments. 

"  Each  gushing  fount  a  marble  cisteni  fills. 
Whose  polish'd  bed  fecciTes^fte  Ming  rills. 
Where  Trojan  dames,  ere  yet  alarm*d  by  Greece^ 
Wa8h*d  their  hxr  garments  in  the  days  of  peace^/' 

There  (s  however  a  passage  of  Pfiny,  an  andidlr 
whom  I  have  often  quoted,  and  who  published  Us 
Natural  History  in  the  first  century,  which  to  mm 
tqipears  perfectly  conclusive. 

**  Of  late  days,"  says  he,  ^  there  were  seen  io  ^ 
amphitheatres  of  the  Emperor  Nero,  fine  cuituas 
of  blue  asure  colour  like  the  sky,  and  the  very  floor 
of  the  ground  under  men*s  feet,  was  coloured  ltd. 
But  for  all  these  paintings  and  rich  dyes,  yet  When 
all  is  done,  the  white  linen  held  the  pre-emintiiee 
Btill,  and  was  highly  esteemed  above  all  colouraO ' 

Pliny  has  likewise  informed  us,  that  the  Q91A 


'  A  writer  of  the  first  century,  speakine  of  linen  garmenti, 
says, "  The  fine  lawn  made  from  the  flax  cmled  Bfsmu,  whtierf 
onr  "wives  and  dames  at  home  set  so  much  store  by,  for  to  t^ 
and  deck  themselves,  groweth  in  Acaia,  and  I  find  that  in  oU 
tines  it  was  sold  as  dear  as  gold."  Holland's  Plm^,  90L  ii^p*^. 

^  Pope*s  lUad,  book  xxii.  line  201. 

*  Holland's  Pliny,  vol.  ii.  p.  5. 


ON  BLEACHING.  259 

and  BritoM  of  his  time  were  acquainted  with  a  mer 
thod  of  bleaehing  linen  cloth,  and  he  tlius  describes 
their  process.  **  After  the  flax  is  spun  into  yarn, 
it^tnust,**  says  he,  **  be  bleached  and  whiten^  by 
being  pounded  several  times  in  a  stone  mortar  with 
wmter :  and  lastly,  when  it  is  woven  into  cloth,  it 
mast^be  beaten  again  upon  a  smooth  stone  with 
broftd-headed  cudgels,  and  the  more  frequently  it  is 
beaten  it  wiU  be  the  whiter  and  softer  ^.'^  The  same 
autbor  tells  us  that  they  sometimes  put  the  roots 
ff  wild  poppies  into  the  water,  to  make  it  more 
efficacious  in  bleaching  linen  7.  "  There  is  a  kind 
of  poppy  (says  he)  much  sought  after  for  bleaching 
Knett  cloth ;  for,  being  scoured  therewith^  it  is  wx)n^ 
dmfol  bow  white  and  pure  they  will  look.  And  yet 
jitople  are  grown  to  this  disorder  and  vaio  enormity, 
ditt  Aty  have  essayed  to  stain  and  dye  their  linen 
tato-ollher  colours,  as  well  as  their  woollen  cloths^/' 

We  learn  from  Theophrastus,  who  was  the  son 
0f  a^fiiller  in  the  Isle  of  Lesbos,  and  who  wrote  300 
JMHB  before  Christ,  that  lime  was  then  employed  in 
hieacbing.  He  relates,  that  a  ship  partly  loaded 
irilh  linen,  and  partly  with  lime  for  bleaching  it, 
WIS  destroyed  by  the  accidental  access  of  water  to 
the  lime. 

^though  it  should  be  proved  that  the  bleaching 
sf  liDcn  is  a  process  of  very  great  antiquity,  it 
ati)D8t  not,  however,  be  supposed  that  any  peopte 


^  Fliof *«  HUt.  Nat.  lib.  xix.  cap.  1 .  §  9. 

'  Ibid.  lib.  XX.  cap.  19.  §  2.     ^  HoUand*A  Pliny,  vol.  ii.  p.  5. 

s2 


260  ON  BLEACHING. 

were  acquainted  Mdth  it  in  the  earliest  stages  of 
their  society,  or  before  they  had  acquired  some  de- 
gree of  civilization. 

The  vestments  of  the  early  inhabitants  of  the 
world  discovered  neither  art  nor  industry.  They 
made  use  of  such  as  nature  presented,  and  needed 
the  least  preparation.  Some  nations  covered  them- 
selves with  the  bark  of  trees,  others  with  leaves,  or 
bulrushes,  rudely  interwoven  s.  The  skins  of  ani- 
mals were  also  universally  used  as  garments,  worn 
without  preparation,  and  in  the  same  state  as  they 
came  from  the  bodies  of  the  animak  9. 

In  process  of  time  recourse  was  had  to  the  wool 
of  animals  i<),  and  this  led  to  the  further  discovery  of 
the  art  of  uniting  the  separate  parts  into  one.ooo* 
tinned  thread,  by  means  of  the  spindle ;  and  thb 
would  consequently  lead  to  the  next  step,  the  in- 
vention of  weaving,  which,  according  to  Demo- 
critus,  ni'ho  flourished  four  hundred  years  before 
Christ,  arose  from  the  art  of  the  spider,  who  gmdes 
and  manages  the  threads  by  the  weight  of  her.own 
body  1 1 .  That  the  invention  of  weaving  was  lopg 
prior  to  the  tin)e  of  Democritus,  appears  from  the 
sacred  writings  i*. 

•  Strabo,  lib.  xi.  p.  781 .     Senec.  Epist.  xc.  p.  406. 

^  Lucretius,  lib.  vi.  ver.  1011.     Pausanias,  lib.  xt.  c.  38. 

1°  Fifteen  hundred  years  before  the  Christian  era,  the  pe^de 
X)f  Palestine  knew  the  value  of  the  fleece  of  their  sheep,  and 
had  regular  seasons  for  collecting  it.  See  Genesis,  zxxi.  19, 
and  xxxviii.  12 — 14. 

^>  Goguet,  vol.  i.  p.  125. 

1*  See  Genesis  xiv.  23.  The  original  is,  "  a  thread  of  the 
woof"     Also  see  Genesis  xxiv.  65. 


ON  BLEACHING.  2f)  I 

After  the  art  of  weaving  had  beeii  invented,  it 
was  probably  not  long  before  flax,  hemp,  and  cot- 
ton, were  employed  in  the  fabrication  of  garments, 
especially  as  the  President  Goguet  has  abundantly 
proved  that  vestments  of  cotton  were  in  use  in  the 
Patriarchal  ages  '^  ;  and  there  can  be  no  doubt  that 
in  the  time  of  Christ  several  nations  had  acquired 
great  proficiency  in  the  manufacture  of  linen  cloth. 

Pliny  describes,  as  growing  in  the  higher  parts  of 
Egypt,  the  cotton  shrub  of  which  clotli  was  made, 
and  "  of  wliich,"  he  says,  "  the  Egyptian  priests 
were  wont  to  have  sfirp/esses,  in  which  they  took  a 
singular  delight '+."  He  also  tells  us  '^  that  vest- 
ments of  cotton  were  worn  by  the  ancient  Egyp- 
tians; !ind  more  than  a  thousand  yt^ars  before  the 
commencement  of  the  Christian  era,  Moses  speaks 
of  robes  of  linen,  and  commands  his  people  "  not 
to  wear  a  garment  of  divers  sorts,  as  of  woollen  and 
linen  together  ""."  The  dress  of  the  ancient  Baby- 
lonians consisted  of  a  tunic  of  lawn,  which  they 
wore  next  to  their  skin.  It  descended,  in  the 
eastern  mode,  to  their  feet  '7.  The  Athenians  wore 
long  robes  of  fine  linen  dyed  purple  '*. 

It  is  not  likely  that  the  materials  of  which  we 
have  been  speaking  were  long  employed  in  the 
manufacture  of  garments,  before  some  method  was 
adopted  of  improving  their  colour    by   artificial 

"  Goguet,  book  ii.  p.  127.  '*  Holland's  P/uip,  ?ol.u.  p.  3. 

"  Pliny,  lib,  %ix.  J  -i.  ">  Deuteronomy  xxii.  1 1 . 

"  Goguet.  vol.  iii.  p.  187.  Herodot.  lib,  i.  n.  195. 
"  Thucyd.  lib.  i.  p.  (j.  □.  (i. 


262  ON  BLEACHING. 

means,  as  has  bden  already  hinted.  Tins  wi&  ap- 
peav  still  more  pvobabie^  wbcn  we  consider  tlwt 
some  of  the  early  inhabitants  of  the  irorld  had  m^ 
9eni  meifaods  which  ia  themselves  tended  teiy 
mtidi  to  whiten  ttnen  and  cotton  dodk 

The  evidence  of  Viinj  is  alone  sufficient  to  proie 
the  tnith  of  dus  assertion.  *'  The  Faventine  doKhr 
says  he,  ^is  always  for  whiter  than  the  AlUaB, 
which  is  ordinarily  brown  when  it  is  new  woven,  and 
before  it  be  bleached.  The  Retovine  linen,  is  C9h 
eeeding  fine;  the  thread  itself  is  more  even  (if  eveiier 
may  be)  than  that  which  the  spider  spinnetb.**  ^  I 
myself  have  seen  so  fine  and  small  a  thread  •f 
Cumes  flax,  that  a  whole  net  knit  thereof^  would 
pass  through  the  ring  of  a  man's  finger.  I  ham 
also  known  one  man  carry  so  many  of  them  (casilf) 
as  would  go  round  and  compass  a  whole  foreat  ^t.^ 

There  is  a  passage  in  Job,  the  most  andeot 
book  extant,  in  which  the  writer  speaks  of  washing 
his  garments  in  a  pit  with  the  herb  jBarithf  whieh 
was  probably  a  plant  that  furnished  an  alkali  ^. 
Homer  describes  Nausicaa  and  her  companions 
washing  their  clothes  by  treading  them  with  their 
feet  ^1 ;  and  according  to  Pliny,  the  ancient  Greeks 
and  Romans  were  acquainted  with  the  detenive 


'y  Holland's  Pliny,  book  xix.  chap.  1. 

^  See  Job  ix.  30.  The  Hebrew  text  has  Bor ;  but  the  Wat 
eommentatore  think  it  is  the  sam£  with  the  Borith  of  Jeremiah 
ii.  22..  and  of  Malachi  iii.  2.  The  latter  of  these  passages  our 
translatoiS  have  rendered  Fuller's  soap, 

2'  Odyss.  lib.  vi.  ver.  92  .  . 


cm  iaKACHiN<».  t08 

properdw  of  several  kindt  of  earth  ^,  m  well  as  of 
aeferal  plants,  which  they  employed  hi  scouring 
linen  ® . 

In  like  manner,  throughout  France  and  some 
other  parts  of  the  Continent^  the  vegetable  called 
Wake  Robin  or  Cuckewpint,  the  Arum  macu* 
laitmi  of  Linn%us,  was  formerly  much  used  in 

The  juiees  of  this  plant  are  said  to 
Ihe  property  of  dissolving  the  resinous  colour* 
matter,  and  rendering  the  cloth  white  ^. 

in  the  passage  of  Homer,  in  which  he  describes 
the  princess  Nairaicaa  and  her  damsels  washing 
the  robes  of  state  for  her  intended  nuptials,  it  ap- 
fMBTsr  ^t  they  were  acquainted  with  the  bleaching 
pDiver  of  the  atmosphere.  Indeed  the  President 
Qoguet  si^poses  that  all  the  linen  Mad  cotton 
dresoeo  ci  ancient  times  were  washed  and  bleached 
Mity  ^,  The  passage  is  translated  by  Pope  with 
spirit;  but  he  has  omitted  the  circumstance  of 
tkeir  treading  the  garments  with  their  feet.  This 
is  the  narrative. 

''  They  seek  the  cisterns  where  PheRoian  damet 
Wash  their  fair  garments  in  the  limpid  sti^antf  ; 
Where  gathering  into  depth  from  falling  rills. 
The  lucid  wave  a  spacious  bason  fills. 
Then  emulous  the  royal  robes  they  lave. 
And  plunge  the  vestures  in  the  cleansing  wave ; 


**  For  an  account  of  the  particular  kind  of  earths  which  the 
Bomans  employed  in  bleaching,  see  Pliny,  cap.  100. 
•*  Pliny,  lib.  xxxv.  §  57  -,  lib.  xxvii.  §  88. 
•*  Dr.  Lewis's  Neumann,  vol.  ii.  p.  226. 
^  Goguct,  vol.  ii.  p.  110. 


264  ON'BL£ACfiING. 

(The  yestures  cleans'd  o*eispreacl  tbe  nhelly  sand, . 
Their  snowy  lustre  whitens  all  the  strand :) 
Then  with  a  short  repast  relieve  their  toil. 
And  o*er  their  limbs  diffuse  ambrosial  oil  $ 
And  while  the  robes  imbibe  the  solar  ray, 
0*er  the  green  mead  the  sporting  virgins  play  ; 
They  sport,  they  feast ;  Nausicaa  lifts  her  voice. 
And  warbling  sweet,  makes  earth  and  heaven  rejoice.'* 

I  would  not  lay  too  much  stress  on  the  evidence 
afforded  by  this  passage,  as  Mr.  Pope  has  made  use 
of  some  epithets  which  are  not  warranted  by  ^ 
original.  The  Scriptures,  however,  contain  amf4e 
testimony  of  the  use  of  linen  garments  in  tiaiea  of 
remote  antiquity.  *    ; 

Having  hazarded  these  few  introductory  re- 
marks, it  may  perhaps  be  .convenient  to  divide  the 
subject  itself  into  two  parts,  consisting  of  the  Ea- 
ropean  methods  of  bleaching  before  the  discovery 
of  chlorine  gas,  and  of  the  practices  which  have 
been  adopted  since  that  period.  I  shall  then  con? 
elude  this  Essay  with  a  brief  account  of  some  of 
the  present  most  important  desiderata  in  bleaching, 
accompanied  with  such  hints  or  proposals  wUch, 
on  a  chemical  review  of  the  subject,  may  suggest 
themselves  as  proper  to  be  submitted  to  the  consi- 
deration of  practical  men. 

Half  a  century  ago  the  linens  of  Holland  were 
the  most  esteemed  of  any  in  Europe,  and  this  arose 
in  a  great  measure  from  the  superior  skill  of  the 
Dutch  in  bleaching.  An  account  of  the  process 
in  the  great  work  at  Haarlem,  and  which  I  copy 
from  a  scarce  book,  printed  in  the  year  1754,  en- 


ON  BLEACHING.  265 

tilled  "  Select  Essays  on  Cwnmercey  ifc.^  will 
therefore,  I  trusty  not  be  uninteresting  to  the  mo- 
dern bleacher. 

"  The  whitening  grounds  of  Haarlem/'  says  the 
author,  '*  are  situated  about  a  league  from  the  city 
gates,  and  the  most  considerable  of  all  is  in  the 
neighbourhood  of  the  village  Bloemendaal.  The 
eause  of  the  wonderful  whiteness  in  the  Dutch 
doths  is  ascribed  to  the  lye-ashes  of  Muscovy,  and 
to  the  water  of  their  downs ;  which  is  nothing 
else  than  sea-water^,  which,  filtrating  through  the 
downs  and  mountains  of  sand,  bursts  out  perfectly 
•weet  and  clear. 

"When  a  piece  of  linen  is  to  be  bleached,  it  is 
in  the  first  place  steeped  in  a  lixivium  or  lye,  where 
other  cloth  hath  been  trod  ;  afterwards  it  is  trod  in 
a  new  lye  of  lye-ashes  ^,  poured  upon  it  boiling 
hot.  This  is  boiled  in  large  copper  caldrons,  and 
is  never  poured  upon  the  cloth  till  it  is  as  clear  as 
wine.  The  linen  is  left  eight  days  in  this  lye,  after 
which  it  is  washed  and  pressed  in  this  manner. 
<  "  They  empty  some  buckets  of  butter-milk  into 
wooden  vessels  fixed  in  the  groimd^^  ;  then  they 
throw  in  a  piece  of  linen,  which  three  men  tread 


••  A  prejudice  formerly  existed  on  the  Continent,  that  no 
perfect  bleaching  could  ever  be  performed  on  grounds  that  are 
situated  at  any  very  considerable  distance  from  the  sea. 

"^  Soon  after  the  introduction  of  bleaching  into  this  island, 
the  Dutch  monopolized  the  pearl-ashes  of  Europe,  and  the  two 
merchants  who  bought  them,  afterwards  supplied  this  country 
at  double  or  triple  the  original  price.  Home  on  Bleaching,  [it  16. 

«•  See  Essay  MI.  vol.  i.  p.  477. 


S6ft  ON  BL£iLGHIKG. 

with  their  feet  as  invck  as  poesftle.  Afterwvds^ 
they  pour  in  more  botter-milk  %  and  then  another 
piece  of  cloth,  proceeding  thus  alternately  till  tbe 
Tess^  are  nearly  iUled,  when  they  fey  j^nka  over 
the  linen^  npoA  which,  they  raise  a  hrge  rotmd  jriese 
of  wood>  or  great  stake,  tonehii^  the  lowei  side  ef 
a  beam,  between  which  and  the  stiJce  th^  drife 
wedges,  to  press  the  cloth.  Six  or  seven  days  aiker, 
they  take  the  cloth  out  of  these  vessels ;  and  if  h 
be  not  white  enough,  they  steep  it  as  we  ha^re  de- 
scribed above.  Afterwards  it  is^  m^ashed,  and  spredl 
out  upon  the  ground  to  bleach.  It  must  be  re-' 
marked  that,  after  every  dipping,  the  cloth  is  waahad 
first  with  black  soap,  then  with  clear  water,  and, 
after  each  of  these  operations,  is  wrung  by  meaoa 
of  a  machine  that  turns  with  a  wheel.*' 

It  will  not  much  interrupt  this  narrative  %a  re* 
mark,  that  at  this  period,  no  one  attempted  to  ex^ 
plain  the  operation  of  the  atmospliere  in  bleaching. 
Many  years  afterwards,  Mons.  BerthoUet,  in  ofdet 
to  be  able  to  account  for  the  effect  of  croftang  Kiien 
and  cotton  goods,  examined  the  dew  which  falls 
from  the  atmosphere,  and  also  that  which  tran» 
spires  from  the  grass,  and  found  both  to  contain  a 
sufficient  portion  of  oxygen  to  destroy  the  colour  of 
turnsol  paper  30. 


^  For  coarse  linens  it  was  usual  to  employ  sours  made  by 
the  fermentation  of  bran  and  water^  instead  of  butter-mUk. 
This  was  prepared  in  different  ways^  as  may  be  'seen  in  Dr. 
HoiA^'s  work,  p.  34. 

^  Annales  de  Chimie,  tome  ii.  p.  158 


ON  BUbACHING.  S4I7 

**  The  whitening  grounds  are  cut  with  canals  in 
maaixf  places,  that  there  may  be  no  trouble  of 
fetching  water  from  a  distance.  The  cloth  is  wa- 
tered with  long  narrow  shovels  made  in  the  shape  of 
a  usythe.  The  water  of  these  canals  comes  from 
Ae  downs,  and  it  is  that  which  contributes  most  to 
tlie  lustre  of  the  Dutch  cloth.  To  prevent  the 
water  from  becoming  thick  and  muddy,  they  are 
extremely  careful  in  cleaning  their  canals.  The 
washing  tubs  are  built  in  with  bricks,  with  two  trap 
doors^  or  sluices,  for  admitting  or  excluding  the 
water,  according  as  it  is  necessary ^i. 

^*  The  greatest  part  of  the  Dutch  cloth  is  made 
of  Silesia  thread,  and  the  linen  wrought  at  Haarlem 
and  Almelo  is  infinitely  superior  to  that  of  all  the 
other  manufectories.  But  the  greatest  part  of  that 
which  b  bleached  at  Haarlem,  is  cloth  from  Silesia 
and  Overyssell ;  where  flax  grows  in  great  abun- 
dance. All  these  foreign  cloths,  after  being  soft- 
ened, whitened,  and  having  obtained  a  gloss,  at 
Haarlem,  are  transported  to  different  parts  of  the 
world,  and  sold  under  the  appellation  of  Dutch 
cloths,  or  Hollands/' 

Such  was  the  process  in  Holland  ^2  sixty  or  se- 
venty years  ago,  when  few  persons,  comparatively, 
had,  in  this  country,  turned  their  attention  to  the 


*'  In  hot  seasons  this  practice  is  very  efficacious.  In  the 
East  Indies^  linens  and  cottons  are  at  this  day  bl^iched  by  mere 
CEpoeure  on  the  grass^  accompanied  with  frequent  watermg. 

^*  An  account  of  a  Dutch  process  somewhat  different  nrom 
tfiis,  may  be  seen  in  Dr.  Home's  work,  p.  23. 


I 


268  ON  BLEACHING. 

subject.  From  a  circumstance  which  accidentally 
came  to  my  knowledge,  I  have  reason  to  think  that 
the  Irish  acquired  the  art  of  bleaching  after  the 
Dutch  method,  long  before  either  the  Scotch  or  the 
English.  The  superiority  of  the  Dutch  linens,  how-^ 
ever,  at  length  awakened  a  laudable  emulation 
among  the  British  manufacturers,  especially  the 
Scotch,  who  for  several  years  much  excelled  the 
English  in  the  process  of  bleaching  all  kinds  of 
goods  made  with  hemp  or  flax,  although  they  had 
formerly  been  in  the  practice,  and  even  so  lately  as 
the  year  1752,  of  sending  all  the  linens  which  had 
been  made  in  their  country  over  to  Haarlem  to  be 
bleached. 

To  send  so  heavy  an  article  to  Holland,  to  be 
returned  again  to  this  country,  was  a  tax  upon  tlie 
British  munufacturer,  which  vva3  not  likely  to  be 
long  endured,  especially  as  all  the  goods  which  had 
been  manufactured  the  preceding  year  were  usually 
senjt  over  in  the  month  of  March,  and  were  never 
returned  to  Scotland,  in  a  finished  state,  until  the 
month  of  October ;  and  then  it  was  necessary  to 
send  them  to  London  to  be  sold,  where  they  were 
disposed  of  under  the  denomination  of  Scotch 
Hollands. 

Other  instances  might  be  adduced  in  abundance, 
to  show  the  inconveniences  which  the  manufactu- 
rers of  this  country  endured  in  the  middle  of  the 
last  century,  from  a  want  of  that  chemical  know- 
ledge which  any  man  may  now  easily  acquire,  ^t 
present  one  circumstance  occurs  to  me,  which  is 


ON   BLEACHING. 


2G9 


connected  with  our  subject,  and  may  deserve  to  be 
mentioned. 

In  the  year  1749,  an  Irishman,  who  had  learnt 
something  of  the  nature  and  ait  of  bleaching,  settled 
in  the  north  of  Scotland,  and  established  a  work 
there  for  the  purpose  of  bleaching  Scotch  goods. 
This  individual  applied  to  some  of  the  most  emi- 
nent of  the  Scotch  manufacturers,  who  were  so 
pleased  with  the  prospect  of  being  nble  to  bleach  at 
home,  that  they  readily  intrusted  him  with  goods 
to  bleach.  These,  however,  were  so  ineffectually 
managed,  that  their  owners  were  compelled  to  send 
them  over  to  Holland  to  be  cleared  and  finished. 
TTie  next  parcel  which  these  proprietors  furnished 
him  with,  were  bleached  no  better;  for,  after  having 
kept  them  in  operation  the  whole  of  that  summer, 
and  half  of  the  next,  the  goods  were  returned  very 
much  injured,  and  even  rendered  tender  by  the 
process.  In  the  course  of  a  few  years,  however,  this 
same  person  became  an  excellent  practical  bleacher; 
all  the  neighbouring  manufacturers  employed  him, 
and  from  that  period  no  more  goods  were  sent  to 
Holland.  The  consequences  of  this  were  two-fold  : 
the  Scotch  manufiiclurers  ivere  mucli  benefited ; 
and  this  persevering  individual  acquired  great  opu- 
lence from  the  profits  of  the  business  which  he  had 
established.  For  the  detail  of  these  circumstances 
I  am  indebted  to  a  gentleman  of  science,  an  inde- 
fatigable Member  of  the  British  Parliament,  who 
collected  them  from  the  manuscripts  of  his  father. 


270  ON  JOJKi^HIIiG. 

w>bo  was  an  eminent  finen  manuCactnrer  in  fte 
north  of  Scotland. 

It  would  occupy  too  much  room  in  theae  pages 
to  describe  separately  each  of  the  processes  that 
were  formerly  adopted  in  these  kingdoms  for 
•bleaching ;  but,  as  that  of  flax  yam  was  one  of  the 
roost  important,  I  have  thou^t  it  worth  while  tb 
relate  how  this  was  conducted,  under  an  idea  that 
such  a  detail  will  prove  interesting  to  the  youog 
bleacher,  who  has  yet  had  no  opportunity  of  wit- 
nessing any  operation  but  that  which  is  effected  by 
chlorine  gas,  or  the  salts  which  are  formed  by  its 
means. 

In  several  parts  of  these  Islands  the  preparatiofi 
of  flaxen  yarn  for  the  manufacture  of  various  kindi 
of  goods,  is  a  business  of  ^ry  considerate  ^ecoM^ 
qnence;  it  is  (or  at  least  has  been)  one  of  the  atapk 
trades  of  the  country. 

A  pound  of  linen  yarn  cannot  be  bleached  at  lets 
than  four  times  the  expense  of  bleaching  a  pound 
d  cotton  yam.  The  reason  is,  that  the  quantify  of 
colouring  and  resinous  matter  to  be  abstracted 
from  the  one  is  much  greater  than  from  the  othet. 
The  thread  made  with  flax  mil  lose  27  per  eeot 
of  its  original  weight  before  it  becomes  perfeetly 
bleached ;  whereas  cotton  j^am  will  lose  only  4^tor 
5  per  cent,  by  a  similar  operation.  The  following 
was  the  process  usually  adopted  for  bleaching  flaxes 
yam. 

The  first  operation,  that  of  steeping^  is  extremely 


ON  BLEACHING.  271 

Biinple.  It  consists  merely  in  immersing  the  brown 
yam  in  hot  water,  or  otherwise  allowing  it  to  ma- 
cerate cold  in  waste  alkaline  lyes.  'When  pure 
water  only  was  used,  the  goods  were  generally  kept 
in  it  for  three  or  four  days,  whereas  with  cold 
alkaline  waste  lyes  forty-eight  hours  were  usually 
deemed  sufBcient. 

The  intention  of  steeping  was  to  occasion  a  kind 
of  vegetable  fermentation,  which  loosened  the  sa- 
liva  employed  in  spinning  the  yarn,  and  so  far  se- 
parated tlie  other  impurities  attached  to  it,  that  the 
whole  were  afterwards  easily  removed  by  washing  in 
river  or  spring  water,  and  wliich,  in  large  concerns, 
was  usually  performed  by  machinery. 

The  next  operation  was  that  of  boiling  in  an 
alkaline  lye,  or  bucking,  after  which  the  skeins  were 
exposed  on  the  grass  for  two  or  three  weeks,  and 
then  boiled  or  bucked  a  second  time,  again  well 
washed,  and  then  crofted  as  before.  Bucking  is  a 
technical  term  for  boiling,  or  steeping,  in  hot  alka- 
line lyes,  in  an  apparatus  which  is  so  contrived  that 
the  lye  flows  alternately  over  the  goods  and  into  a 
heated  copper*.  From  this  a  pump,  which  is  usually 
worked  by  steam,  throws  it  again  on  the  goods, 
tlirough  which  it  percolates  till  it  reaches  the  bot- 
tom of  the  vessel,  when,  by  the  removal  of  a  plug, 
it  is  run  off  again  into  the  boiler,  where  it  becomes 
again  heated,  and  from  whence  it  is  pumped  up  as 
before,  and  the  process  goes   on  uninterruptedly 

*  A  drawing  of  thU  appamtiu  will  be  seen  in  Plate  No.  XX!. 


272  OK  BLEACmNG. 

for  many  hours.  According  to  Dr.  Home,  clear 
sunshine,  with  a  very  little  wind,  is  the  best  weather 
for  bleaching 9^.  Crofting  is  a  technical  phrase  for 
the  act  of  exposing  linen  or  cotton  goods  on  the 
grass.  These  alternate  operations  of  bucking,  wash- 
ing, and  crofting,  were  generally  repeated  four  or  five 
times,  each  time  lessening  the  strength  of  the  alka- 
line lixivium  in  which  the  bucking  was  performed. 

The  next  process  was  that  of  sotmng^  which 
consisted  in  soaking  the  jrarn  in  milk  which  bad 
become  acidulous  by  age,  and  which  was  usually 
employed  for  the  first  time  immediately  after  tlie 
fourth  or  the  fifth  repetition  of  the  bucking  or  the 
boiling  operation.  In  this  liquor,  which  was  tedi^ 
nically  called  the  first  sour^  the  goods  generally  hy 
for  two  or  three  weeks,  or  until  such  time  as  the 
scum  began  to  crack  and  subside,  when  they  were 
usually  taken  out  and  submitted  to  a  repetition  of 
the  several  operations  already  described. 

Thus,  whenever  the  goods  had  been  once  soured, 
the  operations  of  bucking,  washing,  souring,  and 
crofting,  were  repeated  in  regular  rotation,  until 
tlie  yarn  came  to  a  good  colour,  and  was  estedtned 
perfectly  clean.  And  it  should  be  remarked,  that 
these  alternate  applications  of  the  alkali  and  the 
acid,  in  this  mode  of  bleaching,  were  absolutely 
necessary  to  give  the  oxygen  of  the  atmosphere  an 
opportunity  of  acting  upon  the  colouring  matter, 
and  preparing  it  for  the  next  operation.     In  these 

'^  Home  on  Bleaching,  page  70. 


ON  BLEACHING.  S73 

operations  the  alkali  probably  carbonizes  the  co- 
louring matter,  or  puts  it  in  a  suitable  state  for  the 
oxygen  to  convert  it  into  carbonic  acid,  or  into  a 
gaseous  substance,  easily  carried  away  by  the  wind, 
viz.  carbonic  acid  gas.  F'or  if  any  portion  of  the 
alknli  was  left  in  the  goods  when  they  were  laid 
on  the  meadow,  it  would  not  only  prevent  the 
whitening  process  from  going  on  properly,  but 
would  impair  the  strength  of  the  article,  and  in  like 
manner,  though  in  a  less  degree,  the  goods  would 
be  injured  by  the  remaining  acid  ;  but  by  the  con- 
trivance of  using  the  acid  and  the  alkali  alternately, 
each  of  them  becomes  neutralized,  the  resulting 
salt  has  no  injurious  action  on  the  fabric,  and 
yet  it  is  in  a  state  for  being  easily  removed  by 
washing  in  pure  water.  In  these  latter  operations 
a  portion  of  soap  was  always  employed,  it  having 
been  found  that  this  had  the  effect  of  making  the 
goods  handle  better,  and  also  of  cleansing  them 
more  effectually. 

This  method  of  bleaching  was  extremely  tedious, 
so  much  80,  that  if  the  first  operation  was  begun  in 
the  month  of  March,  the  goods  were  seldom  finished 
before  September ;  and  such  as  were  laid  on  the 
grass  for  the  first  time  at  Midsummer,  were  only 
about  half  bleached  that  year,  and  were  laid  by  to 
be  finished  in  the  spring  of  the  following  year.  The 
probable  reason  why  the  proprietors  of  bleaching 
grounds  took  no  measures  to  prevent  this  interrup- 
tion of  the  process  was,  because  they  had  found  by 

VOL.  II.  T 


274  ON  in4jKAcmNG. 

experience  that  the  atmosphere  during  the  numtht 
of  March,  April, ^nd  May ^,  acted  more  ef&cmi*^ 
ousljT  in  whitening  the  goods. 

About  the  middle  of  the  last  century^  these-  le- 
diouB  operations  were  much  shortertedj  by  the  em*" 
jdoyment  of  sulphuric  acid,  instead  of  sour  milk ; 
an  improvement  first  suggested  by  Dr.  Home,  m 
consequence  of  the  new  and  important  proctei 
adopted  about  that  time  by  Dr.  Roebuck,  for  mm* 
nufaoturing  sulphuric  acid,  which  reduced  that  add 
to  one-fourth  of  its  original  price  ^. 

The  public  was,  however,  much  alanned  by  die 
introduction  of  this  acid,  on  account  of  itaeoin* 
aive  nature,  till  Dr.  Home  published  a  voluniebn 
bleaching,  in  which  he  stated  how  much  the  sul- 
phuric acid  is  always  diluted  for  thb  purposfv  tsd 
that  *^  he  had  kept  linen  in  a  strong  sour  of  oil-of 
vitriol  for  many  months,  and  that  the  cloth 
as  strong  after  it  was  taken  out  as  when  it 
put  in  36.- 

No  sooner  was  this  new  agent  employed  in 
bleaching,  than  it  was  discovered  that  one  sourinff 
with  sulphuric  acid  might  be  finished  in  12,  18,  or, 
at  most,  in  24  hours ;  whereas  every  souring  by 
the  milk  process  required  from  two  to  six  wedks» 


^  In  bleaching,  the  ancients  always  gave  a  preference  to  the 
dews  which  fall  in  the  month  of  May.  See  MimoiredeBkmMr 
ment  des  ToUes,  &c.  AnnaUs  de  Chimie,  tome  ii.  p.  159. 

^  See  Essay  VII.  vol.  i.  page  476. 

^  Home  on  Bleaching,  p.  88. 


ON  BLEACHING.  22fi 

according  to  the  state  of  the  weather  and  other  ad? 
yqadtiDUs  dreuinstances.  Besides^-  aourt;  of  this 
description  hasten  very  ^fast  to  cocruption.  Indeed^ 
as  the.  milk  is  generally  kept  .very  long/  it  is  often 
oomipled  before  it  is  used,  and  then,  without  act* 
ingas  an  acid,  it  has  all  the  bad  effects  of  putre* 
fiction  in-  injuring  the  fibre  and  weakening  the 
doth ;.  whereas  the  sours  made  with  sulphuric  acid 
an  not  liable  to  putrefaction. 
.  Berthollet  says  that  he  mode  comparative  .ex* 
periments  on  the  effects  of  sour  milk  and  sulphuric 
aodr  and  found  the  latter  not  only  to  be  more  effi- 
oacious^  but  to  produce  a  better  white  ^.  /  The 
mere  introduction  of  sulphuric  acid  occasioned 
meh  an  improvement  in  the  art  of  bleaching,  that 
tba  whole  process  might  then  have  been  easily  £• 
nUied  in  four  months,  though  it  had  formerly  re- 
qnired  seven  or  eight  months  for  its  completion. 

The  most  important  discovery,  however,  in  this 
business  is  that  of  the  oxy-muriatic  acid  (or  chlo- 
nne),  and  its  application  in  whitening  goods  made 
either  of.  linen  or  cotton.  The  introduction  of 
thia  article  forms  absolutely  a  new  era  in  the  history 
of  this  art;  for  it  not  only  expedites  the  process 
iorprisinglyy  but  has  become  the  means  of  reducing 
the  practice  of  bleaching  to  a  perfect  science. 

For  this  most  important  discovery  we  are  in- 
debted to  Scheele,  who  in  the  year  1774  first 
fonned  chlorine  by  art,  and  afterwards  ascertained 


p««-p*" 


'^  Annalet  de  Chimie,  tome  ii.  p.  159. 

t2 


S78  ON  BLlACBINOi 

iu  powte  in  destroying  vegetable  coloun^;  id« 
AbUgh  it  appeMV  that  at  first  he  inviestigated  Hi 
tMvtte  tnore  as  a  matter  of  curiosity  than  dl  me. 

Several  years  seem  to  have  elapsed  before  any 
oM  thought  of  applying  Uie  peculiar  ptopardes  of 
this  singular  gas  to  any  important  purpose;  and  I 
prdsume  it  was  not  suspected  that  this  poiveffri 
agent  might  be  employed  in  any  considend>le  prt^ 
cess  of  bleaching  linen  or  cotton  until  about  die 
year  1784. 

Hie  first  person  who  made  experiments  upon 
thitgasy  with  a  view  to  its  successfiil  aj^pKcatiiMi 
in  the  arts^  was  M*  BerthoUet,  the  French  dieiinat# 
who  in  the  Journal  de  Physique  for  June  178Bi 
And  i^ain  in  the  number  for  August  l/SS,  e^ 
piliified  the  nature  of  its  action  on  vi^etable  66* 
hHirSy  and  suggested  how  it  might  be  raiployecl  wMb 
advantage  in  any  of  the  existing  establishments*' 

III  tlie  year  1787,  the  Academy  of  Montpdier 
trar^fitnitted  to  Ghaptal  several  observations  dli 
ehlorine,  in  order  to  their  being  printed  in  die 
Nattofial  Memoirs  for  that  year ;  and  a  report  oo 
die  Subject  of  this  communication  was  immediate 
pteMnted  to  the  Royal  Academy  of  Sciences.  TUt 
nj^Wt)  which  contains  many  very  interesdi^  fmt6* 
culars,  ^Ms  afterwards  given  to  the  world  in  tte 
Aknaks  4e  CkinUe^. 

jil>A*i— ^*^  I  I  ■  ii  III  11 1  I   i^<i^*-^.^i»^— ^*         ■    I  ■ —— i^ii— ^aiJ— la— — »>»^ 

^•6ee  Snibt  Omdefd  Eui^  of  Charie$  WiUUm  Sthmk, 
tnmslsted  by  Beddoes,  fix>in  the  TrentacHont  of  the  Acfldem§ 
cf  SdeticBt  at  Stockholm,  p.  90. 

^  Arnmim  de  Chimk,  tome  i.p.  Q9. 


ON  BLEACHING.  277 

In  the  early  part  of  tbe  year  1787,  Mr.  Copland, 
Professor  of  Natural  Philosophy  in  Marischal  Col- 
lege, Aberdeen,  was  accompanying  the  present 
Duke  of  Gordon  in  his  travels  on  the  Continent, 
and  they  passed  some  weeks  at  Geneva,  with  Pro- 
fessor de  Sauasure,  under  whoBe  direction  His 
Grace  had  studied  in  the  early  part  of  his  life  ;  and 
he  showed  these  travellers  the  experiment,  which 
they  had  already  heard  of,  but  had  never  before 
seen,  of  discharging  vegetable  colours  by  means  of 
chlorine  gaa. 

Impressed  with  the  idea  of  the  importance  of 
this  discovery  to  our  manufactures.  Professor  Cop- 
land, on  his  return  home,  comnmnicated  all  the 
circumstances,  and  displayed  the  properties  of  the 
new  gas,  to  some  particular  friends  of  mine,  eminent 
manufacturers  in  that  neighbourhood,  who  imme* 
diately  entered  upon  a  course  of  experiments  for 
the  preparation  of  chlorine,  with  a  Woolfe's  appa- 
ratus, and  obtained  a  very  satisfactory  result. 

Tliis  was  about  the  end  of  July,  in  the  year  1787, 
and  from  that  time  these  gentlemen  continued  to 
apply  this  mode  of  bleaching  in  their  manufactory, 
especially  for  finishing  such  orders  as  were  limited 
in  point  of  time.  But,  in  applying  this  discovery 
to  actual  practice  on  a  large  scale,  they  very  soon 
perceived  tliat  the  circumstance  of  the  gas  being 
prepared  in  an  apparatus  of  glass,  would  be  a  seri- 
ous obstacle  to  its  general  adoption;  and  therefore, 
when  they  came  to  extend  its  application  to  toiler 


278  '  ON  BLEACHING. 

quantities,  they  made  use  of  vessels  of  white  wood 
insteJBid  of  glass. 

The  gentlemen  of  whom  I  now  speak,  and  to 
whom  Professor  Copland  communicated  the  infor- 
mation he  had  obtained,  were  Messrs.  Milnes,  of 
the  house  of  Grordon,  Barron,  and  Co.,  of  Aber^ 
deen  ;  and  I  have  reason  to  believe,  that  theirs  was 
the  first  actual  application  of  chlorine  to  the  pur* 
pose  of  bleaching  either  linen  or  cotton  goods  for 
sale  in  Great  Britain. 

In  the  early  stage  of  the  business,  the  chlorine 
gas  was  procured  by  the  distillation  of  the  common 
muriatic  acid,  from  the  black  oxide  of  manganese; 
the  direction  which  Scheele  had  given  for  tlus  pur- 
pose being  to  mix  4  pounds  of  the  acid  with  4 
pounds  of  water,  and  then  to  distill  this  mixture  in 
a  well  luted  apparatus,  from  one  pound  of  the 
black  oxide  of  manganese,  and  to  collect  the  gas  in 
a  large  receiver  of  cold  water. 

The  last  survivor  of  the  Milnes  above  mentioned, 
was  the  late  Patrick  Milne,  Esq.  several  years  repre- 
sentative in  Parliament  for  the  borough  of  CuIIen; 
It  was  this  gentleman  who  first  informed  me  of  the 
circumstances  just  related,  and  to  him  I  was  in- 
debted for  several  important  facts  contained  in  this 
Essay. 

Fearful,  however,  lest,  in  consequence  of  lapse  of 
time^  my  friend  might  have  forgotten  or  mistaken 
some  circumstiance,  I  took  the.  precaution  of 
writing  to  Professor  Copland,  who  replied,  that  be 


ON  BLEACHING.  270 

perfectly  recollected,  and  acquiesced  in  all  the  par- 
ticulars of  my  statement.  In  addition  to  this  testi- 
mony  His  Grace  the  Duke  of  Gordon,  with  the  ut- 
most afTability  and  condescension,  has  suggested, 
that,  as  it  may  add  to  tlie  authenticity  of  the  ac- 
count, I  am  at  perfect  liberty  to  make  use  also  of 
his  name,  either  in  my  publication  or  in  any  other 
way  in  connexion  with  this  subject. 

At  the  time  of  which  I  have  been  speaking,  M. 
BerthoUet  had  been  engaged  for  twelve  months  in 
investigating  the  nature  of  chlorine  gas  for  the 
purpose  of  ascertaining  the  best  and  most  econo- 
mical methods  of  applying  it  in  whitening  cotton 
and  linen  cloth.  Just  then,  Mr.  James  Watt,  of 
the  Soho,  Birmingham,  happening  to  be  at  Paris, 
M.  BerthoUet  invited  that  eminent  man  to  witness 
his  experiments  ;  and  it  appears  that  he  communi- 
cated to  iiim,  without  reserve,  the  full  amount  of 
the  discoveries  which  he  had  made  in  the  new  pro- 
cess of  bleaching.  From  some  documents  which 
have  been  printed  on  this  subject,  it  would  seem 
that  tliis  unreserved  intercourse  between  these  two 
great  men,  was  kept  up  for  a  considerable  time,  or 
at  least  until  Mr.  Watt  had  made  himself  ac- 
quainted with  the  whole  of  the  favourable  results, 
as  well  as  the  repeated  difficulties  which  M.  Ber- 
thoUet had  experienced  in  the  prosecution  of  this 
business. 

On  the  return  of  Mr,  Walt  to  Great  Britain,  he 
appears  to  have  lost  no  time  in  communicating  the 
wbote  of  the  information  he  had  obtained,  to  hU 


280  pN  BLEACHIIiG. 

relaUve  Mr.  MacGregor,  a  large  bleacher  at  Gbt- 
gow;  for,  in  his  subsequent  correspondenoe  mth 
M.  BerthoUet,  he  informed  him,  that  he  bad  ap- 
plied his  discovery  to  real  practice,  and  in  his  first 
attempt  had  bleached  five  hundred  pieces  of  dotfi 
by  the  new  method.  He  adds  that  .Mr.  Mac 
Gregor  was  so  highly  satisfied  with  the  resnlty  Aai 
he  had  determined  to  continue  the  process. 

Abundant  evidence,  indeed,  might  be  obtained 
from  Scotland,  to  show  that  Mr.  Watt  did  not  re- 
lax in  his  endeavours  until  he  had  established  the 
new  process  in  Mr.  MacGregor^s  bleach-field  on  a 
permanent  basis.  We  have  seen  that  he  continued 
a  correspondence  with  Berthollet  for  a  consideraUe 
time  on  the  subject ;  and  Dr.  Henry  assulres  mcv 
that  he  has  in  his  possession  a  number  of  ketten 
which  passed  between  his  father,  Mr.  Tlionaai 
Henry,  and  Mr.  Watt,  in  the  year  1788,  on  ibt 
business  in  which  they  were  both  so  zealously  en* 
gaged.  In  one  of  these  letters,  which  bears  the 
date  of  the  23d  of  February  1788,  Mr.  Watt  in- 
forms  Mr.  Henry,  that  at  that  very  time  1500 
yards  of  linen  were  bleaching  by  the  new  procesi 
under  his  cUrection ;  and  desires  that  this  circum* 
stance  may  be  stated  to  a  meeting  of  the  manufise* 
turers  and  merchants  of  Manchester,  then  called 
by  public  advertisement,  for  a  purpose  to  be  here- 
after mentioned. 

I  have  been  more  circumstantial  in  these  details^ 
because  I  had  been  charged  with  having  too  sli^tlj 
passed  over  the  exertions  which  were  made  by  Mr. 


ON  BLEACHING.  281 

Watt  to  introduce  the  bleaching  by  chlorine  into 
Great  Britain.  For,  however  the  question  may 
stand  respecting  the  claims  of  priority,  I  was  fully 
aware  at  the  lime  when  the  first  edition  of  these 
Essays  was  published,  of  the  obligations  the  coun- 
try was  under  to  that  gentleman  upon  this  parti- 
cular business,  as  will  appear  from  the  following 
passage : — 

"  I  have  no  doubt",  said  I,  "  that  Mr.  Watt  was 
the  first  person  in  Great  Britain  who  introduced 
science  into  tlie  bleaching  process  ;  for,  before  his 
connexion  with  Mr.  MacGregor,  whose  daughter 
he  had  married,  the  whole  operation  of  bleaching 
was  merely  the  effect  of  observation  and  practice. 
In  justice  to  Mr.  Watt,  it  must  also  be  remarked, 
that  Mr,  MacGregor's  work  was  much  improved 
by  the  former  gentleman,  long  before  he  became 
acquainted  with  BerthoUet,  and  several  years  before 
be  witnessed  his  experiments  with  oxy-muriatic 
acid*." 

When  these  circumstances  are  all  considered,  it 
may  be  difficult,  at  this  distance  of  time,  to  deter- 
mine wliether  chlorine  gas  was  first  employed  in 
the  bleach-field  of  Mr.  MacGregor  at  Glasgow,  or 
in  the  works  belonging  to  Messrs.  Milnes  at 
Aberdeen ;  or,  in  other  words,  whether  Professor 
Copland  or  Mr.  Watt  is  entitled  to  the  credit  of 
having  first  introduced  gas  bleaching  into  some  of 
the  then  existing  establishments  of  Scotland.     Be 


[^fceU^^gteidltion  of_theie  Emm,  vol.  jr.  nagt  55. 


382  ON.BJLSACHINO. 

thiB^  however,  as  it  may,  it  is  pretty .  clear  thai 
both  these  gentlemen  were  zealously  engaged  in 
the  san^  undertaking  about  the  same  period,  and 
that  the  process  was  fiiUy  established  at  Aberdeen 
and  at  Glasgow  long  before  it  was  employed  in  uKf 
other  part  of  Great  Britain. 

But  to  pursue  the  account.:  In  the  year  1786^ 
the  attention  of  several  persons  at  Manchester,  par- 
ticularly that  of  Mr.  Thomas  Henry  ^^  was  directed 
to  the  subject,  and  an  experimental  examinatiim 
of  the  nature  of  the  new  bleaching  agent  waa  en^ 
tered  upon  by  several  individuals  who  had  usnalfy 
been  engaged  in  different  pursuits,  but  who  were 
all  stimulated  by  the  hope  of  obtaining  either  fo^ 
vate  or  public  advantage  from  the  result  of  their  in- 
ve^tigations.  Just  now,  however,  an  unexpected 
circumstance  occurred,  which  was  thought  likdy 
to  be  very  injurious  to  the  town  and  trade  of  Man* 
Chester,  and  this  had  the  effect  of  uniting  the  ef- 
forts of  those  persons  in  that  town  and  neighbours 
hood,  who  had  been  endeavouring  to  acquire  a 
knowledge  of  the  new  process  of  bleaching  by  means 
of  chlorine  gas.  MM.  Bourbollon  de  Bonnueil 
and  Co.  French  Chemists,  had  applied  to  the  En* 
glish  Parliaipent  for  an  exclusive  right  to  the  in? 
vention  of  a  liquid  for  whitening  linen  and  cottcm 
in  a  shorter  time  than  by  the  old  method ;  and  this 
■■    ■  '       '  .  '        .  .  ' 

^>  The  person  here  referred  to  is  the  late  Thomas  He^iji 
Esq.  F.R.S.  President  of  the  Literary  and  Philosophical  Society 
of  Manchester ;  and  author  of  several  works  on  a  Tariety  of  in- 
teresting subjects. 


ON.  BLEACHING;  283 

80  .  darmed  the  printers  and  bleachers  of  Man- 
diesiery  that  a  meeting  of  the  manufacturers  and 
ihtecfaants  of  the  town  was  called  by  public  ad- 
vertisement for  the  express  purpose  of  consi"- 
daring  the  plans  and  the  petition  of  the  said  fo- 
reigners. 

At  this  meeting  half  a  piece  of  calico  was  pro- 
duced which  had  been  bleached  immediately  before, 
by  Messrs.  Cooper,  Baker  and  Taylor,  by  the 
new  method ;  and  at  the  same  meeting  Mr.  Tho- 
mas Henry  produced,  not  indeed  half  a  piece,  but 
lialf  a  yard  of  calico,  which  he  had  just  bleached 
by  chlorine  gas.  What  was  wanting,  however,  in 
quantity,  was  made  up  by  the  quality  of  the  work; 
and  the  smaller  specimen  was  declared  to  be  su- 
perior in  whiteness  to  the  larger  one. 
'  The  result  of  the  public  meeting  was,  that  in 
consequence  of  the  specimens  of  bleached  calico 
which  had  been  produced,  and  of  the  facts  stated 
by  Mr.  Henry,  and  Mr.  Tlioinas  Cooper,  who  was 
abo  a  man  eminent  for  scientific  attainments,  and 
of  a  letter  from  Mr.  Watt  to  Mr.  Henry,  which 
was  read  to  the  meeting,  stating  that  he  had  at  that 
Tery  time  1500  yards  of  linen  bleaching  by  the  new 
proeiess  \mder  his  direction,  the  members  for  the 
county  were  instructed  to  oppose  the  petition  above 
mentioned,  when  presented  to  Parliament.  The 
consequence  of  this  was,  that  the  petition  was  re- 
fused ;  and  afterwards,  when  the  same  people  made 
application  for  a  patent  to  secure  to  themselves 
the  sole  right  of  selling  a  bleaching  liquid,  Mr. 


284  ON  BIJUCHIMO* 


Henry  drew  up. a  Memorial,  which  was  pmeotid 
to  the  attomey^general  against  the  claim  of  die  pe^ 
titioners,  and  which  contributed  in  a  conndendde 
degree  to  thdr  want  of  success.  This  daewncMt 
is  dated  July  2d  1788,  and  contains  an  aqeomlt 
of  the  processes  then  actually  practised  •  bf  Bfr* 
Henry,  and  comprehends  every  thing  -at  ithis^day 
known  respecting  the  use  of  dilorine  gas  in  bleadi^ 
ing,  with  the  exception  of  the  application  of  liioa 
to  the  condensation  of  the  gas.  This  doenmea^ 
which  is  still. preserved,  places  bqron4  aU  coirtni* 
versy  Mr.  Henry's  right  to  rank  among  the  ^t  in- 
pro  vers  of  the  process  of  bleaching. 

I  was  not  aware  of  these  bets  when  the  fomqi 
edition  of  these  Essays  was  published,  or  I  wooU 
not  have  withheld  them  from  that  public  iwhidiis 
indebted  to  Mr.  Henry  for  many  patriotic  and 
benevolent  exertions  during  the  course  of  a  lon^ 
useful  and  honourable  life  ^ . 

That  I  might  give  a  faithful  detail  of  these  par* 
ticulars,  I  have  availed  myself  of  the  account  polk 
lished  by  his  son.  Dr.  William  Henry,  in  one  of 
the  early  volumes  of  Dr.  Thomson's  Annals  of 
Philosophy^. 

Soon  after  the  Manchester  meeting  of  wfaidb*! 
have  spoken,  Mr.  Charles  Taylor,  a  calieo-prinler 


**  For  some  account  of  the  yarious  wntings  of  the  late  Mr. 
Thosiaa  Henry,  see  *'  A  Tribute  to  bis  Memory,*'  publ}iriied:tt 
the  3d  vol.  Second  Series  of  the  Memoirs  of  the  Liierarji  oai 
PhiUmcphkal  Society  of  Manchester,  page  204 — 240. 

*^  See  Thomson's  AnnaU,  toI.  vi.  page  421-^24. 


ON  BLEACHING.  285 

of  Manchester**,  in  conjunction  with  Mr.  Tho- 
mas Cooper,  also  of  Mancliester  *^,  bleached  a 
whole  piece  of  cotton  by  the  new  process,  and 
printed  and  calendered  it  fit  for  the  market  in  less 
than  three  days.  The  success  of  this  experiment 
was  so  decisive  and  unexceptionable,  tliat  Mr. 
Cooper  and  some  other  neighbouring  gentlemen 
were  induced  to  establish  at  Raikes,  near  Bolton, 
in  Lancashire,  a  bleaching  concern  of  very  con- 
siderable magnitude,  to  be  dependent  entirely  upon 
the  agency  of  chlorine  gas. 

Little  doubt  could  now  be  entertained  that  the 
new  process  would  eventually  be  brought  into  ge- 
neral use  :  and  it  will  be  seen  hereafter  that  it  soon 
found  its  way  into  other  parts  of  Great  Britain  be- 
sides Aberdeen,  Glasgow,  and  Manchester. 

I  have  already  adverted  to  the  circumstance  of 
M.  BerthoUet  being  the  first  scientific  chemist  who 
directed  his  attention  to  an  inquiry  into  the  uses 
of  chlorine  gas  in  the  arts;  and  have  also  observed 
that  he  gave  several  memoirs  on  the  subject  to  tlie 
Academy  of  Sciences,  all  of  which  are  preserved  in 
their  collections  for  the  year  1785. 


**  "Hiis  gentleman,  was  afterwards  elected  Secretary  to  the 
Society  inatitul«cl  in  London  for  the  Encouragement  of  Arts, 
Hanumcturea  and  Commerce. 

"•This  gentleman  who  removed  to  America,  and  was  ap- 
pointed one  of  the  Judges  of  the  United  States,  has  lately  puli- 


liahed  a  short  Memoir  on  Bleaching, 
the  Amtrican  Philosophical  Socielfi,  with  drawings  of  a' 
ratua  suitable  for  the  use  of  private  lamilies.  See  vol. 
Series,  quarto,  page  317,  Dr.  Thomas  Cooper  is  r 
President  of  Columbia  College,  in  South  Carolina. 


"/ 


286  ON  BLEACHING. 

In  the  year  178^,  which  was  one  year  after  those 
favourable  specimens  of  the  fiacUities  of  tb^  new 
method  of  bleaching  had  been  exhibited  in  Man- 
Chester,  as  mentioned  above,  M.  Berthollet  brou^ 
the  subject  again  before  the  public  in  a  masteriy 
memoir,  entitled  *^  Du  Blanchhnent  des  ToUeg  et 
des  F%ls  par  FAdde  nniriatique  oxighi^^  ei  de 
quelques  atiires  Propricies  de  cetie  Liqueur  reta^ 
iives  aux  ArtsT  In  this  memoir  he  gave  a  very 
circumstantial  account  of  the  system  of  bleaching 
by  the  new  method,  with  ample  directions  to  the 
manufacturers  respecting  the  construction  of  an 
improved  apparatus  for  the  purpose  of  preparing 
the  bleaching  liquid^. 

•  From  this  memoir  it  appears,  that  gas-bleadnAg 
was  now  adopted  in  various  parts  of  France^/ and 
that  the  chief  obstacle  to  itis  being  brought  into  ge* 
neral  use  was  the  want  of  a  convenient  and  safe 
apparatus  for  the  production  of  the  chlorine  gaa: 
though,  besides  the  inconvenience  of  forming  the 
gas,  great  objections  were  continually  made  to  the 
noxious  nature  of  the  fumes,  which  very  much  an-^ 
noyed  the  workmen.  In  what  manner  this  latter 
difficulty  was  surmounted  will  be  seen  in  the  se- 
quel. The  great  desideratum  was  however  accom* 
plished  by  Berthollet,  and  it  formed  the  main  object 


^  See  AnnaUi  de  Chmie,  tomeii.  p.  151 — 190^  and  tomevi. 
p.  204. 

'  ^7  A  very  particular  account  of  the  methods  of  bltaching  in 
Picardy,  and  also  at  Anjou,  is  given  by  Mr.  Nicholson  in  his 
8vo  Chemical  Dictionary,  article  Bleaching. 


ON  BL£At*HINO.  fS7 

of  his  memoir  to  explidid  rery-  miiluiely  the  con- 
stroction  and  principle  of  the  apparatus  he  had 
ODDtiiwd^  together  with  the  proportion  of  the  ma- 
Ceriab  for  distillation,  so  as  to  render  the  practice 
of  ehemical  bleaching  general  and  efficacious.  His 
direetions  are,  to  use 

6  ounces  of  pulverized  oxide  of  mangunese, 

1  lb.  of  sea  salt, 

12  ounces  of  sulphuric  acid,  and 

12  ounces  of  water. 

A  folio  plate,  accurately  engraved,  accompanies 
the  volume,  with  letters  of  reference,  and  such  an 
ample  description  that  nothing  c^n  be  mistaken. 

Other  writers  advise  proportions  different  from 
those  above  given.  Thus,  Mr.  Rupp  directs  3  parts 
of  manganese,  8  of  salt,  6  of  oil  of  vitriol,  and  12 
of  water  ^ ;  whereas  Tennant  advises  equal  parts  of 
the  three  former,  and  water  equal  to  the  oil  of  vi- 
trioly  hy  measure^  as  noticed  at  p.  293.  In  France, 
the  usual  proportions  are  these :  3  parts  of  manga- 
nese, 10  of  the  salt,  7  of  the  sulphuric  acid,  and  9 
parts  of  water.  But  Sir  Humphry  Davy  says,  per- 
haps on  the  authority  of  Mr.  Duffy  of  Dublin,  that 
**  the  best  proportions  are  3  parts  of  common  salt 
ui  weight,  1  part  of  manganese  finely  powdered, 
and  2  parts  of  oil  of  vitriol."  He  has,  however, 
given  no  directions  as  to  the  quantity  of  water  with 
which  the  sulphuric  acid  ought  to  be  diluted;  which 
is  an  important  consideration. 

♦•  See  Manchester  Memoirs,  vol.  v.  p.  301. 


288  ON  BLEACHING* 

The  memoir  by  BerdioUet,  before  mentioned 
contains  so  many  interesting  particulars  respecting 
the  progress  of  the  new  art,  that  it  wonld  be  im^^ 
possible  for  me  to  do  justice  to  the  subject  yKibiA 
I  have  undertaken  to  elucidate,  Aintbout  repeating 
some  of  the  circumstances  related  by  this  very  acute 
writer. 

At  first  he  was  perplexed  by  the  discovery  that 
the  cloth  was  injured  by  the  process ;  but  in  sub* 
sequent  experiments  he  found  that,  when  the  liquor 
was  considerably  diluted,  he  was  enabled  to  bleadi 
without  impairing  the  strength  of  thq  fobric.  An- 
other difficulty  he  had,  which  arose  from  the  doth 
sometimes  becoming  yellow  after  an  interval  of  a 
few  weeks,  and  this  occasioned  him  much  trouble 
However,  when  he  began  to  try  the  alternate  ac- 
tion of  the  chlorine  gas  and  alkaline  lyes,  he  dis- 
covered that  he  was  able  to  procure  a  perfect  and 
permanent  white  ^.  I  doubt  not  that  Berthollet 
speaks  here  of  his  success  in  bleaching  cotton, 
because  the  process  which  he  describes  always 
leaves  a  yellowness  on  linen  goods,  which  can  onhf 
be  removed  by  a  few  days  exposure  on  the  grass. 

In  the  mean  time,  while  M.  Berthollet  was  en- 
gaged in  these  experiments,  a  Mr.  Bonjour,  who 
had  been  an  assistant  to  Berthollet  in  his  first  at- 
tempts, connected  himself  with  a  Mr.  Constant,  a 
cloth  finisher  at  Valenciennes,  for  the  purpose  of 
forming  a  bleaching  establishment  at  that  town ; 


*^  Annaksxk  Chimie,  tome  ii.  pp.  158,  159. 


ON  BLEACHING.  209 

but,  owing  to  the  violent  opposition  of  the  neigh- 
bouring bleachers,  they  were  unable  to  procure 
ground  for  the  purpose  on  any  reasonable  terms. 

In  this  difficulty,  a  patriotic  French  nobleman, 
the  Count  de  Bdlaing,  who  favoured  the  enterprise, 
and  was  made  acquainted  with  the  extent  of  the 
opposition,  gave  them  possession  of  a  piece  of  land 
at  some  distance  from  the  town,  which  had  all  the 
necessary  conveniencies  for  the  business.  Here  a 
large  establishment  was  formed  in  the  course  of 
the  year  1788;  but  notwithstanding  the  support 
which  the  proprietors  had  thus  received,  the  oppo- 
rition  of  the  old  bleachers,  and  the  inveterate  pre- 
judices of  the  neighbourhood,  were  so  great,  that 
Mens.  Bonjour  was  under  the  necessity  of  iad- 
dressing  the  National  Bureau  of  Commerce  on  the 
occasion.  The  chief  prejudice  arose  from  the  cir- 
cnmstance  of  the  new  proprietors  intending  to  sub- 
stitute chemical  bleaching  for  the  old  process  of 
ashing  and  crofting. 

Soon  after  this  period,  some  manufacturers  at 
Javelle,  near  Paris,  announced  in  several  journals, 
that  they  had  discovered  a  particular  liquor,  which 
they  called  the  Lye  ofJavelle^  having  the  property 
of  bleaching  cloth  by  a  few  hours  immersion.  This 
composition,  which  was  immediately  analysed  by 
Berthollet,  was  found  to  be  nothing  more  than  a 
solution  of  the  oxy-muriate  of  potash ;  and,  on  his 
attempting  to  prepare  the  solution,  he  immediately 
perceived  that  the  addition  of  the  potash  to  the 
water  caused  it  to  imbibe  the  gas  sooner,  and 

VOL.  II.  u 


j^uit  it  likewise  formed  |t  more  eoxiceataraitocl  U(]|ior. 
'This  wa^  similar  to  the  liquid  which  i^  nqw  soM  19 
London  in  small  bottles^  under  the  name  of  hkwiicli* 
ing  liquid,  for  the  use  of  private  families.  A  con- 
venieat  article  for  this  purpose  may  be  prepared  \j 
rineiying  the  gas  which  arises  from  the  dismia^mn 
of  3  pounds  of  common  salt  and  1  pound  of  oma* 
gaveie,  ii^^  H  repeiY^r  containing  1  pound  of  best 
American  pearl-^^h  dissolved  in  4  pounds  of  watcf . 
Two  pounds  of  sulphuric  acid  previously  dilutedvntb 
4  pounds  of  water,  will  be  sufficient  for  extrtcatiDf 
the  gas^.  from  the  materials  above  mentioned. 

At  the  time  when  BerthoUet  published  the  Wlh 
pioir  from  which  I  have  taken  some  of  the  forq[oii;| 
particulars,  few  persons  in  England  were  acquaint^l 
with  any  mode  of  bleaching  by  means  of  chlorinc^eB* 
cept  when  in  the  state  of  gas ;  and  in  this  way  many 
att$a^>ts  were  made,  in  various  places,  by  some  of 
the  best  informed  and  most  practical  men  in  thfir 
respective  districts. 

At  Nottingham,  some  considerable  manu&oto^ 
rers  succeeded  tolerably  well  in  bleaching  small 
parcels  of  linenfyam,  linen,  and  cotton  hosc^  wnA 
other  small  goods,  which  they  effected  in  the  folkNr- 
ing  manner :  The  articles  having  been  suspeniM 
within  large  wooden  boxes,  each  of  which  had  a 
close  bottom  capable  of  holding  water  ^,  the  gas 


^  Am  excellent  apparatus  for  gas  bleaching  was  inyented^ 
Mr.  Rupp.  A  description  of  it  may  be  seen  in  the  5th  voL  i 
the  Memoirs  of  the  Manchester  Fhilosophical  Society,  page  2W 
-313. 


ON  BLEACIUNC4  281 

was  conveyed  into  these  receptacles;  and»  to  pretent 
any  iiQiiry  by  the  immediate  application  of  the  gas^ 
the  gboda  were,  by  means  of  a  frame  and  puUey» 
let  down  occasionally,  and  indeed  frequently^,  into 
the  water  beneath.  But  by  this  method  there  was 
great  difficulty  in  exposing  all  the  surfaces  of  the 
goods  equally,  without  which  no  perfect  bleaching 
can  ever  be  effected. 

This  practice  was  continued,  however,  with  con-» 
siderable  advantage,  though  not  without  its  incon* 
veniendes,  until  the  manufacturers  of  Javelle,  be- 
fiM€. mentioned,  having  been  disappointed  in  thmr 
commercial  prospects  at  home,  came  over  to  £n« 
glandy  and  settled  at  Liverpool,  for  the  purpose  of 
mannfacturing  the  solution  of  oxy-muriate  of  pot* 
aak,  which  they  proposed  to  sell  to  the  English 
bkaachers  in  bottles,  and  which  they  still  denomi- 
nated the  Liquor  de  Javelle. 

These  men,  although  they  h^  been  unable  to 
introduce  their  article  in  France,  so  that  it  might 
have  been  consumed  in  sufficient  quantities  to  an^ 
wwx  their  purpose,  were  so  sanguine  respecting  the 
tale  of  it  in  England,  that  they  applied  to  the  Bri- 
tiih  FtoUament  for  an  exclusive  right  to  the  ipven* 
tion,  for  the  term  of  28  years,  as  before  mentioned. 
Fortunately,  however,  one  of  the  gentlemen  who 
fint  applied  the  oxy-muriatic  acid  to  the  purposes 
of  bleaching  in  this  country,  as  mentioned  at  page 
Vil^  happening  to  be  in  the  gallery  of  the  House 
of  Commons  at  the  time    the  application    waii 

u2 


292  ON  BLEACHING. 

made  in  behalf  of  these  foreigners,  he  took  imnie- 
diate  measures  to  inform  the  principal  .members 
that  this  was  not  a  new  process ;  that  he  himsdf 
had  long  ago  prepared  an  article  equally  efficacious, 
and  that  he  would  be  ready  to  substantiate  the 
truth  of  his  statement  when  required.  This  repre- 
sentation, together  with  the  petition  from  the  town 
of  Manchester,  had  the  desired  effect — ^the  purpose 
of  these  Frenchmen  was  defeated,  and  the  act  whidi 
they  had  petitioned  for,  was  not  obtained. 

Notwithstanding  this  disappointment,  these  geni* 
tlemen  continued  to  carry  on  their  work  at  liver- 
pool  for  a  considerable  time :  but,  from  the  artide 
being  bulky,  and  from  its  constant  loss  of  strength 
by  the  action  of  light,  or  by  exposure  to  the  air,  itut 
obstacles  to  its  consumption  continued  to  augment^ 
until  in  the  end  they  were  obliged  to  relinqoiali  the 
establishment  altogether. 

After  this,  a  Mr.  Foy,  who  had  been  one  of  thdr 
operators  at  Liverpool,  waited  upon  some  of  the 
principal  manufacturers,  and  proposed,  for  a  consi- 
derable premium,  to  erect  for  them  the  necessaiy 
apparatus,  and  to  instruct  them  in  the  process  <rf 
making  the  Liquor  de  Javelle  at  their  respective 
works. 

This  proposal  was  acceded  to  by  many,  and  die 
oxy-muriate  of  potash  was  for  some  time  generally 
employed.  The  combination  of  potash  with  the 
chlorine  has  the  effect,  however,  of  weakening  its 
bleaching  power ;  but  this  is  more  than  compen- 


ON  BLEACHING.  293 

satec!  hy  the  circumstance  of  this  compound  being 
less  obnoxious  to  the  workmen  than  the  oxy-muri- 
attc  acid  alone. 

In  the  year  1798,  Mr.  Tennant,  of  Glasgow, 
took  out  a  patent  for  a  new  bleaching  liquor,  which 
was  a  solution  of  chloride  of  linte  instead  of  that  of 
oxy-muriate  of  potash,  and  which  he  engaged  to 
sell  much  cheaper  than  the  article  that  had  been 
prepared  by  the  foreigners  ;  but  as  this  was  also 
sold  in  a  liquid  state,  one  of  the  main  objections  to 
the  Liquor  de  Javelle  still  remained. 

In  order,  however,  to  remove  this  objection,  Mr. 
Tennant  undertook  to  convey  to  several  manufac- 
turers for  the  sum  of  200/.  to  be  paid  by  each,  a 
right  to  work  under  his  patent;  and  this  proposal 
having  been  accepted  by  many  of  the  principal 
manufacturers,  this  method  of  chemical  bleaching 
was  soon  very  generally  adopted  throughout  the 
kingdom . 

The  drawback  of  the  duty  on  salt,  which  since 
this  period  has  been  granted  by  Parliament  to  all 
those  who  make  these  preparations  for  their  own  use, 
has  induced  not  only  the  bleachers,  but  also  some 
of  the  large  calico-printers,  to  make  their  own 
bleaching  liquors,  especially  since  the  legal  deter- 
mination respecting  the  validity  of  Mr,  Tennant's 
patent ;  so  that  an  apparatus  for  this  purpose  is 
now  considered  to  be  a  necessary  adjunct  to  most 
of  the  printing  establishments  in  the  north  of 
England. 

The  following  is  Mr.  Tennant's  process:  In  a  re* 


S94  jwmhBf^cmw;^ 

omer  containing  ]40  gallons  of  water  (trine 
snre)  he  dissolved  30  pounds  of  commoa  sdty  far 
the  purpose  of  giving  greater  specific  gravity  to  tlie 
water:  the  salt  bong  dissolved^  lie  then  addled  00 
poutods  of  quick  lime  in  an  impalpable  powder^  In 
charging  the  retort  for  the  production  of  the  gn 
30  pounds  of  powdered  manganese  were  mixed  widi 
an  equal  wdght  of  common  salt,  and  to  thb  mh* 
ture  were  introduced  30  pounds  of  sulphuric  acid, 
previobaly  diluted  with  18  pounds  of  water.  Tbeae 
are  the  proportions  which  were  originally  gifen  fay 
Mr.  Tennant  in  the  specification  of  his  patents  He 
directed  that  the  contents  of  the  receiver  should  be 
agitated  constantly  during  the  whole  of  the  distil- 
lation. 

Some  time  after  Mr.  Tennant  had  made  tboM 
arrangements  with  several  of  the  manufoMiliiren, 
some  spirited  individuals  undertook  to  impugn  tbe 
validity  of  his  patent ;  the  consequence  of  wfaidi 
wasy  that  on  the  question  being  submitted  to  a  le« 
gal  decision^  the  cause  went  in  favour  of  the  pob* 
lie,  and  the  right  of  patent  was  lost. 

Since  this  determination,  which  gave  great  satia* 
fiiction  to  the  whole  body  of  manufacturers,  cbeie 
has  been  no  impediment  to  the  method  of  bleacfaiBg 
by  chlorine  gas ;  and  this  chemical  agent  was  fer 
some  time  prepared  at  most  of  the  great  works  by 
the  proprietors  themselves,  and  according  to  the 
process  above  mentioned,  with  perhaps  some  tri- 
fling  variations. 
.  In  the  year  1798,  the  same  year  in  which  Mr.  Ten- 


ON  BLEACHING. 


295 


nant  introduced  the  process  of  combining  the  chlo- 
rine gas  with  lime,  an  Act  was  passed  "  to  allow 
the  drawback  of  tlie  whole  of  the  duties  then  pay- 
able upon  all  salt  of  English  manufacture  which 
should  be  used  and  consumed  in  making  the  oxy- 
muriatic  acid,  provided  such  salt  should  be  mixed 
with  the  other  materials,  in  the  presence  of  an  officer 
of  Excise,  and  in  the  proportions  of  atleast20pounds 
weight  of  sulphuric  acid,  20  pounds  weight  of 
manganese,  and  10  pounds  weight  of  water,  to 
every  56  pounds  weight  of  salt^'.  This  boon, 
which  is  really  very  important  to  the  national  in- 
terests, was  thankfully  received  by  the  manufactu> 
rers  and  bleachers,  and  all  the  large  proprietors  im- 
mediately availed  themselves  of  it. 

The  peculiar  advantages  of  combining  the  chlo- 
rine gas  with  lime  or  potash,  consists  in  this  cir- 
cumstance, that  the  saline  solution  gives  out  the 
gas  gradually  to  the  goods  which  require  bleaching, 
but  does  not  give  it  out  with  facility  to  the  atmo- 
sphere. In  consequence  of  this,  the  operation  of 
bleaching  is  now  not  injurious,  nor  even  very  dis- 
agreeable, to  the  workmen ;  whereas  in  the  for- 
mer process,  when  the  gas  was  merely  received 
into  water,  it  was  given  out  again  so  freely,  that 
no  roan  could  long  endure  to  work  in  it,  or 
even  for  any  considerable  time  to  superintend  the 
operation. 

The  preparation  of  chlorine,  and  the  manufac- 


>  See  the  3Sth  Geo.  111.  citp.  89,  (  8»,  p.  853. 


296  ON  BLEACHING. 

ture  of  bleaching  powder,  are  always  disagreeable 
and  dangerous  operations,  and  ought  not  to  be  un- 
dertaken by  any  but  experienced  men.  That  emi* 
nent  French  chemist,  M.  Pelletier,  lost  his  li£e  bj 
inhaling  a  large  quantity  of  chlorine  gas ;  and  I 
have  lately  been  informed  of  another  instance  of  the 
fatal  effects  of  this  potent  agent,  which  occurred 
very  soon  after  its  discovery  by  Scheele.  Mr.  R04 
of  Ringsend  near  Dublin,  a  young  man  eager  in 
the  pursuit  of  chemical  knowledge,  died  after  a 
very  short  illness,  in  consequence  of  his  inspiring 
this  gas  too  freely,  while  engaged  in  making  expe- 
riments to  investigate  its  nature  and  properties. 

In  resuming  the  account  of  the  process  of  bleach- 
ing it  may  be  observed,  that,  in  addition  to  the 
foregoing  advantages,  resulting  from  the  combinap 
tion  of  lime  with  the  chlorine,  the  saving  in  in- 
terest of  capital  is  incalculable,  as  will  appear  from , 
one  or  two  considerations. 

In  bleaching  iinen  goods,  in  a  great  work,  where 
one  large  parcel  follows  another,  in  regular  succes- 
sion, and  through  the  different  operations,  five 
weeks  is  as  much  as  is  now  ever  allowed  for  tbdr 
completion,  and  a  small  parcel  can  be  begun  and 
finished  in  a  few  days ;  whereas,  by  the  old  pro- 
cess, the  effect  could  never  be  fully  produced  in 
less  than  eight  months,  as  I  have  before  mentioned. 
Now,  a  country  person  who  weaves  only  a  single 
piece  of  cloth,  may  bleach  it  himself,  and  have  it 
immediately  ready  for  market.  Indeed,  were  these 
poor  weavers  properly  instructed,  it  would  be  of  great 


ON  BLEACHING.  '19? 

semcetothe  manufacturing  Interests  of  the  nation. 
The  introduction  of  chlorine  has  also  taught  the 
scientific  bleacher  to  understand  the  nature  of  his 
materials,  and  the  proper  use  of  them.  Thus,  the 
economical  workman  of  the  present  day  brings  all 
bis  alkaline  lixiviums  to  the  most  caustic  state,  and 
then  reduces  them  by  water  to  the  proper  degree  of 
strength  for  his  respective  operations.  I  have  the 
pleasure  of  being  acquainted  with  the  proprietors 
of  a  Urge  bleach-field,  who  have  told  me,  that 
they  formerly  used  12  cwt.  of  Dantzic  weed  ashes 
to  bleach  a  ton  and  a  half  of  linen  yarn ;  but  that 
since  they  have  learnt  how  to  ascertain  the  good- 
ness of  the  material  by  chemical  analysis,  they  are 
enabled  to  finisli  the  same  quantity  of  yarn  with 
2  cwt.  of  caustic  American  potash,  which  costs 
them  not  more  than  one  fourth  of  their  original 
expenditure.  Here  is  a  manifest  proof  of  the  incal- 
culable value  of  chemical  knowledge  to  a  manufac- 
turer. The  solution  of  chloride  of  lime  the  eco- 
nomical bleacher  treats  also  in  the  same  way,  and 
ascertains  Its  strength  not  merely  by  the  hydrometer 
proof,  but  by  the  real  degree  of  power  which  It  has 
of  discharging  vegetable  colours.  The  difference 
between  the  hi/dromeler  strength  and  the  discharge 
strength  is  very  important ;  because,  if  the  former 
only  be  attended  to,  the  liquor  may  be  so  strong 
of  muriate  of  lime  as  to  have  a  proper  specific  gra- 
vity and  yet  have  a  very  weak  effect  in  bleaching ; 
whereas,  if  the  article  be  made  up  merely  by  its 
discharging  strength,  or  its  power  of  depriving  a 


298  ON  BUUCItlKC. 

solution  of  indigo  of  its  colour,  it  may  be  r^t  in 
this  respect,  and  ytet  contain  so  mudi  muiiata  of 
lime  as  would  be  injurious  to  the  goods  bleached  bgr 
it.  Sir  H.  Davy  for  the  purpose  of  experimnt 
boiled  some  linen  in  a  strong  solution  of  muriate 
of  lime,  and  found  the  fabric  of  the  dotli  mmk 
impaired  by  the  process* 

Moreover,  the  bleaching  of  linen  yam  wat  for- 
merly very  seldom  accomplished  with  less  than  firom 
33  to  35  per  cent,  of  waste,  whereas  the  waafee  now 
is  not  more  than  26  or  27  per  cent.  This^  of  it- 
self, is  a  presumptive  proof  that  the  goods  are  less 
injured,  and  evinces  the  superiority  of  the  present 
practice.  Berthollet  has  very  properly  remarikiedy 
Uiat  *^  by  the  old  method  the  small  bleacher  was 
always  obliged  to  sell  his  doth  to  a  disadvantage; 
the  large  manufacturer  had  his  capital  locked  up 
for  a  longer  time  than  is  now  necessary ;  and  the 
consumer  had  not  so  good  or  so  strong  cloth  as  lie 
may  now  have  by  the  new  process.  Hie  bringing 
back  into  agriculture  the  vast  quantity  of  land  for- 
merly employed  for  bleaching,  and  this  at  the  finest 
season  of  the  year,**  he  adds,  **  is  likewise  no  small 
advantage  ».** 

The  difference  in  the  quantity  of  the  waste  by  tiie 
two  processes  arises  from  a  circumstance  that  is 
not  much  known,  but  which  alone  ought  to  be  suf* 
ficient  to  remove  the  prejudice  which  is  generally 
entertdned  against  what  is  called  chemical  bleadi- 

^  Jnnalet  de  Chimie,  tome  ii.  p.  184, 


ON  BLEACHING.  290 

ing,  viz.  that  the  chlorine  process  when  properly 
conducted  removea  only  the  resinous  matter  and 
other  filth  ;  whereas  the  long;  exposure  on  the  grass, 
and  the  various  and  reiterated  operations  of  the  old 
method,  waste  also  a  part  of  the  fibre  itself,  and 
consequently  weaken  the  whole  fabric. 

This  reminds  me  of  another  erroneous  idea  which 
is  Tery  prevalent  and  ought  to  be  corrected,  viz.  that 
no  kind  of  acid  can  be  employed  with  effect  in 
bleaching,  without  the  cloth  sustaining  an  injury. 

I  have  heard  of  a  dispute,  which  arose  only  a 
few  years  ago,  between  a  confidential  agent  of  the 
British  Government  and  the  principals  of  a  large 
manufacturing  establishment,  who  had  a  great 
quantity  of  white  canvass  refused  because  it  was 
discovered  that  diluted  sulphuric  acid  had  been  em- 
ployed in  bleaching  it,  after  it  had  been  stipulated 
that  the  process  should  be  completed  without 
acids.  In  fomiing  this  contract,  the  proprietors 
of  the  bleach-works  had  an  eye  only  to  the  prohibi- 
tion of  what  was  then  called  the  oxy-niuriatic  add 
and  its  compounds,  never  having  conceived  an  idea 
of  bleaching  without  the  employment  of  some  kind 
of  sours  to  remove  the  adhering  alkali.  VVhat 
tended  to  confirm  the  prejudice  was  this,  that  an 
appeal  had  been  made  to  an  eminent  chemist,  who 
bad  declared  that  the  use  of  acids  in  bleaching  must 
always  be  injurious. 

In  opposition,  however,  to  this  authority,  I  have 
no  hesitation  in  pronouncing  that  no  good  bleaching 
can  ever  be  effected  without  acids.  There  would  be 


300  ON  BLEACHING. 

no  safety  in  doing  it,  and  it  is  what  no  experieneeci 
bleacher  would  ever  attempt ;  because,  were  acidi 
not  to  be  employed  to  neutralize  the  alkali  wludi 
had  been  used  in  the  previous  operation,  the  alkali 
which  remained  would  not  fail,  when  assbted  bf 
the  sun*s  rays,  to  injjire  and  in  some  measure  de* 
stroy  the  cloth.  This  effect  is  so  certain,  that  it 
will  happen  to  the  goods  should  they  ever  be  lud 
on  the  grass  only  after  one  single  operation  with- 
out being  soured.  This  sometimes  occurs  firoin 
the  carelessness  of  the  workmen ;  but  whenever 
this  happens  in  summer,  it  can  always  be  detected 
by  the  master,  as  the  colour  of  the  goods  will  be 
deteriorated,  and  they  will  have  become  what  the 
bleacher  calls  lye-bumi. 

Now  that  I  have  ventured  these  remarks,  the 
next  step  will  be  to  give  an  account  of  some  of  the 
MODERN  processes  in  bleaching,  which  I  shall  en- 
deavour to  do  with  as  much  brenty  as  is  consistent 
with  perspicuity.  It  will  be  most  convenient  to 
begin  with  the  process  of  bleaching  linen  yam  and 
linen  cloth. 

In  effecting  this,  the  same  methods  are  followed, 
as  far  as  to  the  fourth  or  fifth  bucking,  as  were  for* 
merly  employed  in  bleaching  linen  long  before  the 
application  of  chlorine,  and  which  have  already 
been  detailed  at  page  270 — 273;  only  good  washing 
is  resorted  to  instead  of  crofting.  This  being  pre- 
mised, the  remaining  operations  may  be  described 
with  less  difficulty. 


ON  BLEACHING. 


301 


it  may  be  asked,  Why  is  not  ctilorine  now  em- 
ployed in  these  first  processes  of  bleaching  linen 
goods  ?  The  reason  is,  because  it  would  be  too 
expensive  j  for  there  would  be  a  greater  expendi- 
ture of  the  chlorine  gas  in  the  removal  of  the  filth 
and  the  resinous  matter  than  is  now  incurred  in  the 
whole  process,  and  these  are  all  taken  out  in  a 
much  cheaper  way  by  the  sohitiiHi  of  alkali  and  by 
repeated  wushings  in  pure  water.  The  solution  of 
chlorine  is  not  necessary  for  tliu  removal  of  the  re- 
sin, but  it  is  indispensable  in  discharging  the  co- 
louring  matter  and  the  c:irbon. 

It  should  be  recollected,  that  no  bleaching  can 
ever  be  carried  on  to  advantage,  unWs  the  water 
be  pure  and  in  great  abundance.  Hence  Scotland 
seems  to  be  peculiarly  calculated  for  such  establish- 
ments; for,  as  I  have  been  informed,  there  are 
many  parts  of  that  kingdom  which  abound  with 
spring  water  that  comes  from  the  granite  rocks 
nearly  in  a  state  of  absolute  purity. 

After  the  fourth  or  fifth  bucking,  the  goods  are 
,  immersed  in  a  solution  of  chloride  of  lime,  and  are 
then  well  washed  by  machinery  in  pure  water. 
I  They  are  now  carried  to  the  souring  vessels  con- 
taining a  portion  of  very  dilute  sulphuric  acid  ;  and 
when  taken  out  of  these  vessels,  they  are  again  vtell 
washed  in  water ;  and  lastly,  they  are  submitted 
once  more  to  the  alkaline  process  mentioned  at 
pap  271. 

TTiis  kind  of  goods  requires  at  least  three  immer- 
Bions  in  the  solution  of  chloride  of  time,  followed 


302  on  BLEACHING. 

by  an  equal  number  of  altecnate  immemionB  in  the 
sours  and  in  the  alkaline  solotion,  carefiiUjr  tnd 
thoroughly  washing  them  in  pure  water  between 
each  of  these  prooesses.  It  shonld  be  remeinbeied, 
however,  that  linens  require  generally  a  greater 
number  of  immersions  in  the  bleaching  liquor  tlM& 
cottons,  and  abo  tihat  the  preparation  be  less  diluted 
with  water. 

By  this  method  of  bleaching,  linen  goods  con^ 
stantly  acquire  a  yellowish  tinge;  this  however  H  so 
superficial,  that  mere  exposure  to  the  air  for  a  fifsr 
days  generally  removes  it.  The  goods  are  then  fi- 
nished by  boiling  them  for  a  short  time  in  a  dilute 
solution  of  pearlash  and  white  soap.  This  last  ope^ 
ration  has  the  effect  of  removing  the  disagreeable 
odour  which  otherwise  would  for  a  long  time  be  at* 
tached  to  every  article  bleached  by  this  process.  It 
must  here  be  remarked,  that  when  cotton  goods  .are 
bleached  after  this  manner,  there  is  no  necessity  for 
crofting ;  as  the  yellow  tinge  just  mentioned  daM 
not  appear  in  them  when  finished;  any  stain  of  that 
kind  being  completely  removed  by  the  sulphuric 
acid,  though  this  acid  will  not  remove  it  from  linen 
goods^. 

We  may  also  notice,  that  bleaching  with  chlo-^ 
ride  of  lime  will  not  answer  for  those  cotton  goodtf 
which  are  designed  for  the  madder  copper,  because 
the  sours,  (diluted  sulphuric  acid,)  however  perfect 
the  washing  may  be,  will  fix  the  earth  within  the 

^  See  the  account  of  BerthoUet's  experience  in  this  parti- 
cular at  page  288. 


ON  UBACHINO.  SOS 

poret  of  die  cloth  ^;  and  although  the  lime  Uius 
find,  maj  he  in  a  very  minute  quantity,  indeed  so 
niaiite  as  not  to. be  detected  in  any  other  way»  its 
eSeet  will  not  fail  to  be  seen  when  the  goods  have 
been  passed  through  the  decoction  of  madder.  The 
aolphate  of  lime  being  a  mordant  for  the  madder, 
H  urill  inevitably  occasion  a  stain,  and  arrest  the  co- 
Umi  on  those  parts  of  the  cloth  which  are  designed 
tabe  preserved  white. 

Whenever  this  salt  becomes  fixed  within  the 
pores  of  the  cloth  designed  for  madder  work, 
it  wOl  most  certainly  produce  stains  in  the  white 
ground  which  cannot  be  removed  by  crofting.  I 
suspect  this  is  an  evil  of  more  usual  occurrence  than 
many  printers  imagine ;  for  I  have  seen  the  kiers, 
which  are  large  wooden  vessels  used  in  bleaching, 
covered  on  their  insides  with  sulphate  of  lime.  This 
appearance  shows  that  the  workmen  did  not  wash 
the  goods  completely  when  they  came  out  of  the 
iOiirs.  Some  bleachers,  indeed,  designedly  omit 
washing,  because  they  imagine  that  the  portion  of 
the  acid  which  adheres  to  the  cloth  is  useful  In  giv- 
IPg  activity  to  the  chlorine. 

I  have  likewise  to  notice  another  fault  in  this  de- 
partment of  the  business,  viz.  that  of  using  pieces 
of  sheet  lead  occasionally  for  lining  or  securing  parts 
of  the  kier  which  are  thought  to  be  in  danger  of  leak- 
ing. This  is  improper ;  because  the  sulphur,  which 
ip  always  contained  more  or  less  in  potash,  acts  up- 

**  See  an  account  of  the  Scotch  mode  of  bleaching  calicoes 
for  the  madder  copper,  in  a  subsequent  part  of  this  Essay. 


304  ON  BLEACHING. 

on  the  lead,  and  gives  it  a  red  coat  of  sulphuret  of 
lead,  which  will  stain  the  goods  coming  in  contact 
with  it.  I  have  also  seen  bowking-houses  where 
the  goods  have  sustained  an  injury  from  the  iron 
nails  used  in  the  roof  of  the  building ;  for  where  the 
roofs  of  such  buildings  are  put  together  with  nuls, 
the  steam  from  the  boiling  vessels  will  be  condensed 
by  the  tiles,  and  the  water  resulting  therefrom,  wash- 
ing off  the  oxide  of  iron  from  the  corroded  nails, 
will  inevitably  stain  the  white  calico  on  which  it  frdk. 
To  construct  a  building  in  the  best  manner  for 
bleaching,  there  ought  to  be  no  iron  in  the  roof,  nor 
any  lime  employed  in  the  inner  side  of  the  walls,  as 
the  smallest  quantity  of  lime  or  iron  would  materi- 
ally injure  those  white  calicoes  which  are  designed 
for  printing. 

On  these  accounts,  the  large  printers  who  bleach 
their  own  goods,  frequently  use  oxy-muriate  of  pot- 
ash or  oxy-muriate  of  soda  for  all  the  cottons  wUch 
are  to  be  dyed  with  madder.  This  was  recommend- 
ed so  long  ago  as  the  year  1789,  by  Mr.  Thomas 
Henry  of  Manchester  and  M.  D^croisille,  and  was 
afterwards  communicated  by  BerthoUet  to  M.  Ober- 
kamp,  an  eminent  calico-printer  at  Jouy,  as  an  agent 
for  clearing  the  whites  of  maddered  goods .  M.  Ober- 
kamp  immediately  embraced  the  proposal,  and  con- 
tinued the  practice  ever  after  ^^.  It  is  a  curious  dr- 
cumstance,  that,  although  this  plan  of  clearing  the 
whites  of  printed  goods  originated  in  a  great  mea- 

'^  See  Annales  de  Chimie,  tome  ii.  p.  187. 


ON    BLEaCHINR. 


305 


9UK  at  Manchester,  none  of  the  English  printers 
shonld  have  been  aware  of  the  importance  of  the 
practice  till  more  than  twenty  years  after  its  intro- 
duction at  Jouy-  To  get  rid  of  the  selenite,  or  ra- 
ther to  prevent  its  bein^  formed,  attempts  have  been 
made  to  vary  the  process  by  following  ihe  dip  in  the 
solution  of  chlorine  with  an  immediate  immersion 
in  the  alkaline  solution  instead  of  the  immersion  in 
the  sours;  but  this  has  always  failed  of  success. 

It  ia  a  common  opinion,  that  the  manufacturers 
give  the  preference  to  the  new  process  of  bleaching 
on  account  of  its  being  cheaper,  and  because  the 
materials  for  chemical  bleaching  cost  less  than  those 
which  were  employed  in  the  old  method ;  but  this 
is  not  the  fact.  Bleaching  by  the  new  process  is  m 
much  dearer  as  is  the  amount  of  the  cost  of  the  so- 
lution of  chloride  of  lime  :  but  the  great  economy 
ia  in  the  saving  of  labour  ;  in  the  certainty  and  se- 
curity of  the  process  ;  in  the  less  degree  ofwaste^^j 
in  the  shortness  of  the  time  employed  ;  and  in  the 
comparative  smallness  of  the  interest  «|>on  the  capi- 
tal engaged  in  the  buKiness. 


There  is  a  considerable  trade  now  carried  on  in 
the  bleaching  of  hose.  The  following  Is  the  pro- 
cess usually  adopted,  the  accuracy  of  which  may  be 
relied  on,  as  it  was  communicated  to  me  some  years 
ago  by  one  of  the  partners  in  an  extensive  manu- 
factorVt  who  had  came  to  London  for  the  purpose 


"^  Far  an  explanation  of  this  see  page  2 


306  ON   BLEACHING.  ' 

of  consulting  me  respecting  some  difficulties  Xvhidt 
had  occurred  in  their  manufactory^  and  which  at 
that  time  were  attended  with  considerable  loss  and 
inconvenience. 

Although  it  may  be  considered  a  digression^  some 
persons  may  be  glad  to  be  informed  that  the  stodc* 
ing-loom  was  invented,  about  the  year  1590,  by  the 
Rev.  Wm.  Lee  of  St.  John's  College  Cambridge^ 
This  gentleman  being  desirous  of  bringing  the  ma« 
ebine  into  general  use,  and  unable  to  procure  any 
remuneration  from  the  Government  of  his  own 
country,  he  went  over  to  Rouen  in  Normandy,  wheie 
some  spirited  individuals  undertook  to  introduee 
him  to  the  French  Minister,  who  gladly  afforded  him 
protection  and  patronage.  He  had  previously  ^ 
plied  to  Queen  Elizabeth ;  and  it  must  appear  note 
little  extraordinary  that  this  monarch  should  have 
refused  him  her  support,  when  it  is  recollected  what 
patronage  she  afforded  to  Daniel  Houghsetter  and  to 
many  other  foreigners,  whom  she  had  invited  from 
different  places  on  the  continent  of  Europe  to  iir^ 
struct  her  subjects  in  useful  arts,  and  in  the  estib^ 
blishment  of  new  manufactures. 

In  the  establishments  for  the  manufacture  of  cM- 
ton  hose,  the  stockings  are  first  scoured  in  soap  and 
water,  to  divest  them  of  the  oil  and  other  impuit- 
ties  applied  in  the  process  of  weaving ;  because  the 
weavers  of  cotton  hose  always  dissolve  mutton  suet 
in  melted  soap,  and  pass  the  goods  through  the  mix- 
ture. This  serves  a  double  purpose ;  it  occasions 
the  thread  to  work  better,  and  renders  the  goods 


ON    BLEACHING.  307 

heavier  when  they  are  returned  in  a  finished  atate 
to  the  owner. 

It  is  in  consequenceof  this  practice  that  the  bleach- 
er is  under  the  necessity  of  scouring  such  goods  in 
a  solution  of  soap  made  scalding  hot ;  for  it  would 
be  in  vain  to  attempt  to  bleach  them  without  first 
divesting  them  of  this  tallow,  and  of  tlie  dust  and 
other  impurities  which  will  unavoidably  be  attached 
to  it.  To  obtain  this  the  more  eliectually,  they  are 
removed  from  the  scouring  vessels  into  pure  water 
and  thoroughly  washed,  the  water  being  changed  as 
often  as  is  considered  necessary.  Many  inexpe- 
rienced persons,  who  have  begun  the  business  of 
bleaching  and  also  that  of  dyeing,  have  failed  of 
success  in  consequence  of  their  not  being  aware  of 
the  absolule  necessity  there  is  for  observing  the  ut- 
most cleanbness  in  both  these  occupations. 

The  second  process  consists  in  boiling  tiie  hose 
in  a  weak  alkaline  solution,  made  by  dissolving  three 
pounds  of  American  pearlash  in  three  hundred  gal- 
lons of  water.  ^Vhen  boiled  in  this  lixivium,  tbey 
are  merely  rinsed  in  clear  water,  and  are  then  con^ 
ttidered  to  be  suHiciently  prepared  for  being  submit- 
ted to  the  action  of  the  bleaching  liquor.  The 
bleacher  of  piece  goods  would  consider  this  to  be  a 
very  weak  lixivium,  for  in  that  process  it  is  not  an 
unusual  thing  todissolve  the  above  weight  of  caustic 
potash  in  so  small  a  quantity  as  ten  gallons  of  water. 

The  bleaching  liquor  for  cotton  hose  is  prepared 
by  mixing  six  or  eight  quarts  of  the  solution  of  chlo- 
ride of  lime,  in  the  state  in  which  it  is  prepared  at 


S08  .  ON  EL£ACBING» 

the  stilly  with  20  gallons  of  water;  In  this  nuao* 
ture  the  hose  are  immersed,  and  they  are  auflferad 
to  remain  an  hour  and  a  half  or  two  hoars.  iSbfCf 
are  then  taken  ont^-  and  waslied  thoroughly  in  jooU 
water,  *  ....  * 

The  process  of  immersion  in  the  bleaching  liqiud 
is  now  repeated,  and  this  is  followed  by  boiling  the 
goods  in  an  alkaline  lixivium,  as  before..  .Theaa-pm^ 
cesses  of  steeping  in  the  chloride  of.  lime  aiid«iif 
boiling  in  a  solution  of  alkali,  are  .rqpeated  km 
times  alternately,  and  then  the  hose  are 
found  to  be  bleached  suffidently.  The 
there  is  for  these  repeated  steepings  in  the  sohitiM 
of  the  chloride  of  lime,  may  be  thus  ^^p^^inr^ 
«  The  chlorine  that  is  liberated  decomposes  a  poiAMMa 
of  the  water,  the  oxygen  of  which  combinea  :wilh 
the  colouring  matter,  and  renders  it  soluble^  in  :the 
alkali,  '.  * 

These  processes  bdng  finished,  the  goods  are 
then  immersed  in  diluted  sulphuric  acid,  which  hm 
been  so  much  lowered  with  water,  that  it  is  bcoome 
little  more  acidulous  than  vinegar,  and  naay  be 
taken  into  the  mouth  with  perfect  safety.  .  Tlus 
carries  off  any  earth  or  other  matter  not  snffideitd^ 
soluble  in  the  alkali.  The  steeping  in  this  wtak 
acidulous  liquor  is  generally  continued  about  three 
hours,  though  sometimes  the  hose  aresuflbredM 
remain  in  it  for  a  whole  night. 

It  has  been  found,  by  repeated  experiments,  that 
so  long  as  the  goods  are  actually  immersed  ia  tbe 
sours,  tiiey  sustain  ho  ii^ory ;  whereas^  if  th«y  w«re 


ON  BLEACHING.  JU9 

taken  out  and  suffered  to  become  dry,  their  tex- 
ture would  be  much  weakened,  and  the  damage 
would  be  irreparable  ^7.  This,  I  have  no  doubt,  is 
occasioned  by  tiie  evaporation  of  the  water,  by 
whicli  the  sulphuric  acid  attached  to  the  goods 
becomes  concentrated  and  caustic. 

To  divest  the  hose  of  the  remans  of  the  sulphu- 
ric add,  they  are  washed  many  times  in  cold  water, 
and  even  submittc^d  to  the  action  of  a  kind  of  full- 
ing mill,  called  fal/ers,  which  cleanses  these  goods 
more  effectually  than  could  be  done  by  any  other 
method.  But  so  difficult  is  it  to  remove  the  lost 
portions  of  the  sulphuric  acid,  that  the  manufactu- 
reri  find  it  necessary,  even  after  all  this  washing,  to 
immerse  them  in  a  hot  solution  of  soap  and  vege- 
table alkali,  to  finish  their  purification.  The  pro- 
portions are  4  pounds  of  white  soap,  1  pound  of 
best  pearlush,  and  150  gallons  of  water.  This  pro- 
cess is  technically  called  scalding.  This  removes 
tlie  disagreeable  smell  of  the  chlorine  gas,  at  the 
same  time  that  it  improves  the  appearance  of  the 
goods  to  the  eye,  and  occasions  them  to  feel  softer. 

The  hose  are  now  carried  again  to  the  fallers; 
where  they  are  scoured  and  beaten  in  soap  and 
water,  as  before,  the  remains  of  which  are  perfectly 
washed  out  with  successive  portions  of  pure  cold 
water.  This  is  said  to  complete  the  process  of 
bleaching. 


'  See  an  account  of  Dr.  Home  8  experiment  on  this  subject, 
'^jofthii  Es«iy. 


3 10  ON  BLEACHING. 

•  These  goods  are  afterwards  exposed  to  another 
process  called  getting  np^  which  is  performed  in 
the  following  manner*  They  are  put  into  a  copper 
of  hot  water,  containing  a  weak  solution  of  'soap^ 
with  the  addition  of  a  little  indigo,  sufficient  to 
give  them  a  tinge  of  blue,  and  then  they  are  le^ 
turned  to  the  fallers  to  be  scoured  in  a  still  stronger 
solution  of  soap.  This  solution  is  strong  enough 
to  produce  an  actual  lather,  and  the  remains  of  it 
are  thoroughly  washed  out  with  cold  water,  which 
finishes  what  is  called  the  cleansing  process.  The 
whitening  effect  of  indigo  when  laid  on  a  yellow 
ground  is  very  remarkable,  and  is  well  known  to 
laundresses. 

When  the  operator  has  very  fine  goods  to  bleacb»* 
he  has  recourse  to  a  process  somewhat  diflferent, 
which  consists  in  immersing  them  in  a  very  hot 
solution  of  soap,  with  the  addition  of  a  little  ground 
indigo.  The  hot  soap  gives  them  a  gloss  which  is 
much  approved  of  and  occasions  them  to  handle 
better  than  common  hose,  and  the  indigo  improve^ 
their  colour.  The  common  goods  are  immersed  in 
indigo  and  water  only. 

When  all  these  successive  operations  have  been 
duly  practised,  the  hose  are  then  removed  to  the 
drying  stove,  where  care  is  taken  that  they  shall  be 
dried  completely.  From  this  they  are  carried  to  a 
room  called  the  brimstone  stove,  where  they  arc 
entirely  enveloped  by  the  vapours  of  sulphurous, 
acid  gas,  arising  from  the  burning  of  sulphur  in  a 
close  chamber. 


ON  BLEACHING.  31  I 

The  use  of  this  process  is  to  decompose  any  por- 
tion of  aoap  that  may  still  be  attached  to  the  sur- 
face of  the  goods ;  for  it  has  been  found  that,  if 
they  are  laid  up  for  any  considerable  length  of  time 
without  their  having  undergone  this  operation,  the 
smallest  poition  of  soap  remaining  in  them  will 
occasion  them  to  turn  yellow.  The  manufacturer 
would,  indeed,  be  glad  to  dispense  with  the  use  of 
soap  altogether ;  but  there  is  no  article  besides  this 
that  will  elTectualiy  take  away  the  smell  of  the  chlo- 
rine gas. 

When  the  hose  are  returned  from  the  brimstone 
stove,  they  are  slightly  damped  with  common  water, 
to  prepare  them  for  the  finishing  operation,  known 
by  the  name  of  dressing.  This  consists  in  drawing 
each  stocking  separately  on  a  stocking-leg  board, 
in  whith  state  they  are  either  put  ooiieetively  into  a 
powerful  press,  or  ironed  singly  with  a  hot  box-iron. 

These  are  the  method'*  which  are  generally 
adopted  in  bleaching  and  finishing  thread  and  cot- 
ton hose^B,  and  they  appear  to  be  so  well  adapted 
to  their  respective  purposes,  that  but  very  few  re- 
marks upon  them  will  be  needful. 

It  occurs  to  me,  however,  that  the  goods  might 
be  materially  injured  were  they  ever  to  be  put  into 
the  brimstone  stove  in  a  damp  state ;  for  the  vapour 
would  then  be  condensed  upon  them  in  the  form  of 


*'  The  prices  nt  Nottingham,  for  bleaching  and  finishing 
hose,  are  generally  from  '2s.  ta  2t.  3d,  per  dozen  pair;  for 
pieces  of  calico  measuring  28  yards  the  ueual  charge  is  U.  6d. 


312.  ON  BLBACHIKO.' 

sulphurous  acid  ;  and  when  treated  afterwards  mth 
the  hot  iron,  tbia  acid  would  become  concentrated 
aiid  impair  the  texture.  Whea  the  hose  are  dressed 
by  the  press  only,  it  is  not  so  necessary  to  attend  to 
this  .  circumstance.  Another  injury  would  lesull 
from  this  management,  viz.  that,  being  put  damp 
into  the  stove,  some  parts  would  retain  more  water 
than  others;  and  here,  I  conceive,  dark  spots  woiild 
arise  should  the  goods  be  laid  by  for  a  condderaUe 
time  undisturbed,  a  circumstance  which  often  ac« 
tually  happens  in  the  shop  of  the  retailer. 

Only  one  thing  more  occurs  to  me,  which  is  this, 
that  the  omission  of  weaving  the  blue  and  the  red 
lines  in  the  top  of  hose  which  are  intended  to  be 
bleached,  will  conduce  to  injure  the  credit  of  the 
manufacturer  in  foreign  markets^*  I  propose,  how* 
ever,  to  offer  a  few  remarks  on  this  at  the  close  of 
the  EiS&ay. 

Nothing  has  yet  been  said  of  the  method  of 
bleaching  calicoes  for  the  use  of  the  prinier;  for 
this  embraces  a  great  number  of  questions,  and  is  a 
subject  of  very  considerable  difiiculty.  The  fol- 
lowing is  the  process  which  is  generally  adopted  in 
the  neighbourhood  of  Manchester,  and  throughout 
the  county  of  Lancaster. 

When  the  goods  have'been  fired  to  remove  ths 
nap,  as  described  in  Elssay  IV.  vol.  i.  pages  262,263; 


^J  At  the  desire  of  a  respectable  bleacher  in  the  county  of 
Nottingham,  I  published  a  few  years  ago  some  obserratioDs  on 
this  subject  in  the  Tradesman's  Magazine.    See  vol.  ii.  p.  105. 


OM  BLEACHING.  313 

tbeyjtfesteeped  for  a  certaio  time  in  pure  water» 
imudly  until  so  much  of  the  inopurities  is  loosened 
firom  them  as  occasions  a  very  sensible  fermentation 
in  die  water^  the  time  varying  from  twelve  to 
twenty-four  houre ;  or  in  soap  and  water,  or  in 
an  alkaline  lye  which  has  been  already  used  in  the 
process  of  buckings  or  bowking,  as  it  is  commonly 
called  in  this  district.  This  appears  to  me,  how- 
ever, to  be  a  very  bad  practice,  because  such  lyes  are 
always  very  dirty  and  loaded  with  resinous  matter 
and  other  filth  of  a  similar  kind  to  that  which  it  is 
the  object  of  the  bleacher  to  remove.  How  niuch 
better  would  it  be  to  boil  down  such  waste  lyes,  or 
evaporate  the  water  from  them  by  means  of  a  vane 
to  be  turned  by  the  steam  engine,  and  then  to  re- 
cover the  alkali  by  some  economical  process !  No- 
thing but  pure  water,  or  clean  lye,  or  good  white 
aoap  and  water,  ought  ever  to  be  employed  for  these 
steeps.  The  temperature  at  which  this  steeping  is 
conducted  varies  from  that  of  100  to  160  or  180 
degrees,  according  to  circumstances  or  the  parti- 
cular views  of  the  operator. 

The  pieces  are  then  washed  in  pure  water;  in 
large  works  this  is  done  by  means  of  a  dash-wheel, 
which  washes  them  more  effectually  than  they 
oould  be  by  any  other  method  ;  and  then  they  are 
immediately  bucked  ^,  or  boiled  in  a  solution  of 

^  For  an  account  of  the  bucking  apparatus,  see  the  descrip- 
tion of  the  plates  which  accompany  this  volume,  and  also  page 
371  of  this  Essay. 


314  ON  BLEACHING. 

caustic  potash,  and  the  boiling  is  continued  for 
eight  or  ten  hours.  From  the  boilers  thejr  m 
again  taken  to  the  wash-wheel,  and  cleansed  tho« 
roughly.  The  process  of  boiling  is  repeated  two  or 
three  times,  taking  care  to  wash  wdl  after  evay 
operation.  Each  of  these  boilings  is  usually  coim 
tinued  for  the  same  length  of  time,  but  care  is 
taken  that  the  alkaline  lixivium  be  reduced  in 
strength  at  every  repetition  of  the  process.  In  lai|^ 
concerns,  where  the  process  of  bleaching  is  conti* 
nually  going  on  night  and  day,  the  boiling  is  geniM 
rally  done  in  the  night,  and  the  subsequent  opoa* 
tion  of  washing  is  performed  in  the  day  time.  After 
two  of  these  boilings,  some  people  pass  the  goods 
into  the  sours,  whereas  others  do  not  sour  them 
until  they  have  been  three  or  four  times  boiled. 

The  goods  are  then  laid  on  the  grass  for  two  or 
three  days;  or,  if  crofting  be  not  employed,  an 
effect,  similar  to  that  which  would  be  produced  by 
exposure  to  the  atmosphere,  is  obtained  by  an  im« 
mersion  in  a  solution  of  chloride  of  lime,  of  about 
the  specific  gravity  of  1*005.   In  this  they  steep  foe 
twelve  hours;   and   then   they  are  removed  into 
sulphuric  acid,  diluted  with  about  forty  times  its 
weight  of  pure  water.  Mr.  Murray  says  that  this  last 
souring  imparts  a  much  finer  whiteness  to  the  doth 
than  it  would  acquire  without  this  treatment,  as  it 
dissolves  the  remaining  colouring  matter  which  had 
resisted  the  action  of  the  alkali  and  oxygenated  add, 
as  well  as  a  small  quantity  of  iron  contained  in  all 


ON  BLEACHING.  315 

▼egetabfe  matter,  or  deposited  on  the  cloth  from  the 
alkaline  lyes  ^1. 

After  this,  the  pieces  are  washed  with  the  greatest 
eare  in  successive  portions  of  water,  and  are  then 
hang  up  in  the  dry-houses,  to  be  dried  completely 
for  use,  by  a  current  of  atmospheric  air,  which  is 
perpetually  passing  through  them. 

When  the  operation  is  to  be  performed  on  fine 
cloth,  it  is  usual  to  boil  once  or  twice  more  in  a  still 
weaker  solution  of  potash,  and  to  finish  them  in 
strong  sours,  made  by  the  mixture  of  one  measure 
of  sulphuric  acid  with  46  measures  of  water,  or  one 
pound  of  the  acid  to  twenty-five  pounds  of  water. 
This  is  not  because  fine  cloths  require  the  most 
Meaching,  but  on  account  of  such  cloth  being  gene* 
rally  used  for  the  finest  kind  of  printing ;  for  the 
heaviest  pieces  are  generally  the  most  difficult  to 
Ueach  perfectly.  In  some  houses  it  is  customary 
to  lessen  the  weight  of  the  potash  one-third  for 
every  subsequent  boiling.  / 

Some  printers,  instead  of  potash,  use  lime  water, 
and  others  even  cream  of  lime  for  the  first  bowking; 
washing  and  souring  being  adopted  the  same  as  if 
potash  were  employed ;  but  in  these  cases  care  is 
taken  not  to  allow  the  liquor  to  acquire  more  than 
a  scalding  heat. 

This  is  truly  a  cheap  method ;  but  I  conceive  it 
to  be  a  very  bad  practice,  because  where  this  mode 
is  adopted  plenty  of  selenite  will  unavoidably  be 

^*  Miiimy's  Chemistry,  2d  edition,  vol.  ii.  p.  660. 


310  ON   BL£ACHIN6. 

formed  in  the  cloth»  and  nothing  will  perfectly  re- 
move it.  It  is  well  known  to  many  printers  wboae 
works  are  situated  upon  rivers,  that  if  a  piece  which 
has  been  thorqugbly  prepared,  should  by.  accident 
drop  into  the  river  at  the  time  of  flood,  wbea  the 
water  is  charged  with  eartb»  it  would  be  entirdy 
spoiled  for  the  madder  copper.  No  kind  of  souring, 
nor  any  mode  of  treatment,  which  we  are  at  pre- 
sent acquainted  with,  would  repair  the  injury. 

Some  printers  use  the  common  potaah  of  cam^ 
merce,  while  others  employ  an  alkali  which  has 
been  made  completely  caustic  by  lime;  othen^ 
again,  mix  a  portion  of  soft  soap  with  the  potash 
for  one  or  two  of  the  first  bowkings ;  so  far  are  these 
manufacturers  from  being  agreed  as  to  every  parti- 
cular respecting  these  operations. 

I  must  not,  however,  forget  to  mention  that  in 
large  works,  after  every  process  of  ashing,  souring, 
or  bleaching,  the  pieces  are  submitted  to  a  power- 
ful press,  usually  one  of  Bramah's,  to  force  out  the 
chemical  liquor  which  remains  in  them ;  and  that 
it  is  from  the  press  they  are  taken,  either  to  the 
river  or  the  wash-wheel,  for  further  purification. 
Some  of  the  printers  have  not  yet  adopted  the  use 
of  the  press ;  but  the  professed  bleachers  are  awaie 
of  its  importance,  and  employ  it  constantly.  In 
several  works,  I  find  it  is  a  common  practice  to  pass 
the  goods  through  a  pair  of  wooden  rollers  made 
of  sycamore :  these  force  out  a  great  deal  of  impu- 
rity, and  they  make  all  the  pieces  of  an  equal  dry- 
ness.   This  is  not  general,  but  I  consider  it  to  be 


ON  BLEACHING.  317 

an  eligible  practice,  and  that  it  ought  to  be  per- 
formed after  every  operation. 

Although  I  have  now  given  a  short  account  of 
the  processes  which  are  employed  in  bleaching 
common  calicoes,  or  what  is  known  in  some  di- 
stricts by  the  tenn  of  surface-bleaching,  I  still  con- 
sider tlie  series  of  operations  to  be  very  imperfect, 
because  the  goods  thus  bleached  artf  often  unfit  for 
the  purposes  for  which  they  are  intended,  and  very 
frequent  and  serious  losses  have  been  sustained  in 
consequence  of  it,  as  every  printer  can  testify. 
Tiiis  is  very  severely  felt  by  those  who  print  for 
hire,  as  such  printers  are  expected  to  make  allow- 
ances for  all  imperfect  work,  and  these  are  often  so 
enormous  as  to  absorb  all  the  cost  of  materials  and 
the  expense  of  printing. 

A  knowledge  of  this  circumstance  first  induced 
me  to  turn  my  attention  to  the  subject  of  blenching; 
and  the  hope  of  being  able  to  ofl'er  some  useful  hints 
to  the  consideration  of  practical  men  laid  the  foiin> 
dation  of  this  Essay. 

From  frequent  and  repeated  conversations  with 
many  of  the  most  intelligent  bleachers  in  various 
parts  of  the  kingdom,  1  have,  1  presume,  clearly 
ascertained  that,  in  preparing  goods  for  the  pur- 
pose of  calico-printing,  the  following  are  the  most 
important  desiderata. 

First.  To  form  such  a  preparation  of  bleaching 
liquid,  with  the  respective  materials  so  nicely  ba- 
Uoced.  that  neither  the  salt,  nor  the  fluid  which 


318  ON  BLEACHING. 

which  temains  after  the  abstraction  of  the  4^1oriiie, 
shall  have  any  injurious  effect  upon  the  fabric  of  the 
cloth.  Those  who  bleach  with  chlorine  should 
never  lose  sight  of  the  circumstance,  that  coniuioo 
muriatic  acid  is  always  produced  at  the  moment 
when  the  oxygen  of  the  water  unites  with  the  co- 
louring matter ;  and  that  this  acid,  if  not  corrected 
by  other  ingredients,  will  have  an  unfavourable  ae- . 
tion  on  the  goods  under  operation.  Sir  Humphiy 
Davy  says,  that  he  has  tried  the  muriate  of  lime 
which  remains  after  the  common  process  of  bleach 
ing,  and  that  he  found  cloth  which  he  boiled  in  U 
to  be  considerably  weakened ;  but  that,  if  chloridt 
of  magnesia  were  substituted  for  chloride  of  lim^ 
the  muriate  of  magnesia  which  results  would  not 
impair  the  fabric. 

Secondly.  To  bleach  the  calicoes  in  so  perfect  a 
manner  that  each  piece  of  every  parcel  shall  be 
completely  fit  for  madder-work;  that  is,  when 
deared  after  being  dyed  in  a  madder-copper,  that 
the  whites  shall  be  uniformly  good  and  free  from 
those  stains  which  the  superintendants  in  this  de- 
partment of  our  manufactures  call  spangs.  For 
this  purpose,  some  manufacturers  lay  great  stress 
on  the  use  of  an  apparatus  somewhat  similar  in  its 
principle  to  a  Papin's  digester,  and  known  by  the 
name  of  a  whaU^boUer.  For  a  description  of  tMl 
vessel,  see  the  Plate  No.  xxi.  and  the  explana  ion 
of  it  at  the  beginning  of  this  volume. 

Thirdly.  To  prepare  calicoes,  so  that  they  shall 
^readily  take  a  light  and  uniform  shade  in  the  blue 


ON*  BLEACHING.  819 

tmt.  .  Qoth  dried  in  summer  and  in  the  open  air, 
when  the  atmosphere  is  dry  and  warm,  dips  much 
more  freely' in  the  blue  vat  than  that  which  is  dried 
in  winter,  especially  in  frosty  weather,  when  the 
pieceji  require  more  exposure.  In  like  manner^ 
atove-drying  is  never  esteemed  so  good  as  tenter* 
drying,  for  any  purpose  of  fine  printing. 

In  dipping  pale  blues,  the  printer  often  sustains 
great  loss  by  the  pieces  coming  out  of  the  vat  with 
white  streaks,  so  as  to  render  it  necessary  to  bleach 
diem  afresh,  and  then  to  appropriate  them  for  the 
reception  of  other  colours.  This  is  occasioned  by 
'm  substance  existing  in  the  cloth,  which  resists  the 
action  of  the  blue-vat,  and  yet  is  not  of  sufficient 
consequence  to  rise  to  a  spang  when  it  is  afterwards 
passed  into  the  madder  copper.  *^ 

Every  man  has  a  different  process  for  preparing 
his  blue-vats ;  therefore  the  want  of  uniformity  in 
the  shade  of  these  colours  may  sometimes  arise 
from  the  vats  being  in  bad  order,  or  it  may  be 
owing  to  the  employment  of  bad  indigo.  I  would 
suggest  that  it  might  perhaps  be  advisable  to  appro- 
priate a  vat  of  either  the  finest  Guatamala,  or  of 
the  purest  East  Indian  indigo,  entirely  to  the  pur- 
pose of  dyeing  paie  blues ;  and  that  where  the  style 
of  work  will  allow  of  it,  (though  it  often  will  not,)  it 
might  be  worth  while  to  try  whether  superior 
bunging,  previously  to  the  blue  dipping,  would  pre- 
vent the  evil  complained  of. 

Fourthly.  To  prepare  any  number  of  pieces 


320  OK  BLBACRING. 

which  shall  be  fit  for  both  the  above  purfxtaes,  jti 
still  be  preserved  perfectly  sound. 

It  is  evident  to  me  that,  in  effecting  these  pointSi 
the  main  difficulty  originates  with  the  weaver ;  and 
therefore,  to  those  who  are  not  conversant  with  the 
business,  it  may  be  advisable  to  explain  how  this 
happens,  before  we  attempt  to  suggest  a  remedy. 

llie  weaver  of  calicoes  generally  proceeds  tfaas . 
Having  a  fine  warp  delivered  to  him,' frequently 
spun  beyond  what  the  staple  of  the  cotton  audio* 
rizes,  and  consequently  not  capable  of  bearing  aiich 
hardship,  he  is  compelled  to  throw  in  as  much  weli 
as  will  make  the  cloth  of  a  very  close  texture ;  biy 
only  aim  being  to  accomplish  this  object  with  the 
least  possible  trouble,  and  at  the  least  expense*    " 

As  soon,  therefore,  as  he  has  fixed  the  warp  m 
the  loom  and  stretched  it  out  ready  for  weaving;  be 
dresses  it^  by  rubbing  it  longitudinally  betiveeA 
two  brushes  which  have  been  previously  dipped  te 
a  paste  made  of  potatoes,  or  flour  and  water.  This 
paste  is  generally  suffered  to  become  sour  before  it 
is  used,  and  frequently  it  is  kept  in  an  iron  kettle 
till  this  change  takes  place. 

When  this  dressing  has  become  dry,  in  order  to 
make  the  warp  still  smoother,  he  applies  a  different 
dressing,  made  with  such  greasy  or  oleaginous  matp 
ters  as  he  can  the  most  easily  procure.  This  gene- 
rally is  either  tallow  or  butter,  and  is  sweet  or  ran* 

■  ■>■ 

«=  See  Essay  IV.  vol.  i.  page  264. 


ON  BLEACHING. ,  32 1 

dd,  as  may  accidentally  happen ;  but  tallow  is  the 
article  which  is  the  most  commonly  used,  and  it  is 
iapplied  in  the  following  manner.  The  weaver  hav- 
ing prepared  a  hot  iron^  he  takes  that  in  one  hand 
and  a  lump  of  tallow  in  the  other,  and  pressing  them 
together,  the  tallow  becomes  partially  melted  and 
drops  in  patches  on  various  parts  of  the  warp. 
This  is  afterwards  dispersed  and  spread  over  the 
wibole  warp,  by  means  of  the  brushes  which  were 
eniployed  to  spread  the  paste  before  mentioned. 

Instead  of  tallow,  why  might  not  soft  soap  be 
employed  ?  It  would  be  desirable  for  some  manu- 
&cturer  to  give  this  a  fair  trial.  Should  it  answer 
the  weaver^  purpose,  it  might  afterwards  be  readily 
removed  by  washing.  See  an  observation  on  this 
rabject  in  vol.  i.  page  264. 
.  It  will  be  manifest  to  those  who  have  considered 
this  mode  of  procedure,  that  the  subsequent  spread- 
ing of  the  tallow  cannot  be  effected  without  the 
grease  being  left  in  the  largest  quantity  on  those 
places  where  it  was  first  applied  ^.  Accordingly, 
it  is  found  that  these  spots  are  often  particularly 
diacemible  when  the  goods  come  to  be  dyed,  al- 
though the  operator  may  have  supposed  that  they 
fpere  well  cleaned,  having  undergone  the  usual 
motine  of  steeping,  boiling,  souring,  bleaching, 
washing,  printing,  and  dyeing.  For  an  account  of 
aomemethods  for  examining  the  goodness  of  the 


« 


May  not  this  be  the  origin  of  what  are  called  copper-stains^ 
tioned  in  the  following  parugraph  ? 
rni.    ¥1  V 


mentioned 
VOL.  II 


32ft  ON   BLEACHING. 

bleaching  of  white  ^ieoes,  see  the  Essay  on  Calico 
Printing,  vol.  i.  page  265. 

Printed  calicoes  are  also  often  stained  in  largeK 
blotches,  though  not  so  conspicuous  as  those  just 
mentioned,  but  evidently  arising  from  grease ;  ge« 
nerally  covering  a  larger  portion  of  the  cloth,  and 
very  difficult  to  be  removed.  The  workmen  distiB* 
guish  these  by  the  name  of  copper  stains,  supponog 
them  to  have  arisen  in  the  madder-copper  from  an 
unequal  application  of  the  heat.  This,  however,  b 
Undoubtedly  an  erroneous  opinion. 

In  reviewing  the  preceding  observations  the  M* 
lowing  questions  suggest  themselves. 

If  grease  be  the  chief  impediment  to  perfect 
bleaching,  what  are  the  best  means  of  removing  it? 
Are  any  of  the  alkaline  solutions  we  have  mehtioaedL 
capable  of  effecting  its  removal  Y  In  answer  to  this 
query,  I  would  say,  Take  caustic  potash,  properIy£f 
luted  with  water,  and  not  the  dirty  waste  Ijre,  an 
article  often  resorted  to.  For,  in  preparing  for  fin^ 
madder  work,  I  am  confident  that  what  is  considecf 
ed  to  be  a  cheap,  economical,  and,  I  may  be  per* 
mitted  to  add,  dirty  mode  of  bleaching,  can  never 
do.  On  the  contrary,  for  such  work,  the  most  ex* 
pensive  bleaching  will  generally  prove  to  be  the 
cheapest  eventudly ;  for  the  pieces  have  a  better 
chance  of  being  perfect,  and  the  dyeing  materials 
will  go  further. 

Is  soap  (either  soft  or  hard)  of  any  service  in  die 
process  of  steeping,  or  that  of  boiling  ?  Is  lime  of 


ON   BLEACHING.  323 

ittelf  a  solvent  for  grease  ?  If  lime  should  be  found 
to  be  adequate  to  this  purpose,  is  there  any  proba- 
bility of  its  injuring  the  texture  of  the  cloth  when 
used  in  the  manner  already  described  ?  And  is  there 
not  some  danger  of  particles  of  this  earth  remaining 
in  the  cloth  after  the  most  careful  washing,  and  of 
its  forming  a  sulphate  of  lime  by  immersion  in  the 
sdtirs^  ?  • 

When  goods  have  turned  out  spangged,  is  it  ad* 
disable,  in  order  to  prevent  a  repetition  of  the  evil^ 
and  will  it  be  consistent  with  the  preservation  of  the 
texture  of  the  cloth,  to  have  recourse  to  more  of  the 
alkali,  to  greater  heat,  or  to  more  frequent  boilings!^ 
Or  is  any  other  plan  preferable  to  all  or  any  of  these? 
Where  perfect  work  is  required,  I  conceive  the  pro- 
per answer  to  this  query  to  be  this.  Let  the  alka-< 
Hue  lye  be  reduced  in  strength,  and  then  let  the  usual 
niitnber  of  boilings  be  doubled.  That  is,  let  them 
b^' boiled  at  least  seven  or  eight  times. 
•  On  the  principle  of  boiling  in  a  vessel  somewhat 
analogous  to  a  Papin*s  digester,  what  degree  of  heat 
dan  be  employed  with  safety  to  the  cloth  ?  It  will 
be  seen,  that  in  the  common  process  of  boiling  the 
pieces,  the  lye  being  weak  and  exposed  to  the  pres- 
sure of  the  atmosphere  it  can  never  much  exceed 
the  temperature  of/212^. 

What  is  the  substance  contained  in  cotton  which 
resists  the  action  of  the  blue-vat,  or  of  cold  water, 
and  yet  does  not  act  as  a  mordant  in  the  madder 
copper  ?  I  am  disposed  to  think  that  this  is  a  ques- 


.  .i 


*^  For  an  answer  to  this,  see  pagen  ^02,  303. 

y2 


324  ON   BLEACHING. 

tion  which^  in  the  present  state  of  chemical  know- 
ledge, no  one  is  able  to  answer,  although  it  b  well 
known  to  every  printer  of  the  present  day,  that  such 
a  substance  does  exist,  and  that  it  often  occaaoos 
much  trouble  and  perplexity. 

Is  it  originally  in  the  cloth,  or  is  it  acquired  du- 
ring the  bleaching  process,  or  by  tlie  goods  bang 
improperly  kept  after  they  have  undergone  all  the 
processes  of  bleaching  ?  This  is  not  Ukely  ever  to 
be  the  case ;  for  I  well  know  that  the  appearances 
to  which  I  refer  are  often  seen  in  goods  which  are 
dyed  and  printed  directly  from  the  hands  of  the 
bleacher. 

What  is  the  cause  of  those  marks  called  copper- 
stains,  already  noticed  ?  Are  they  owing  to  a  portion 
of  alkali  being  left  in  the  cloth  during  the  c^pera- 
tions  of  bleaching,  or  may  they  be  ascribed  to  insnf- 
iicient  washing  after  the  process  of  dunging  ?  These 
are  certainly  not  copper-stains,  but  are  possiUy 
owing  to  improper  bleaching.  It  is  likely,  indeed, 
in  most  cases,  that  these  would  not  have  appeared^ 
had  the  bleaching  been  prolonged  or  the  different 
operations  oftener  repeated. 

The  whole  of  these  questions  seem  to  arise  na- 
turally from  a  due  consideration  of  this  subject,  and 
all  of  them,  I  believe,  have  at  one  time  or  other 
been  proposed  to  me  by  various'  practical  men,  for 
my  opinion ;  a  circumstance  which  convinces  roe 
that  much  remains  to  be  done  before  the  art  of 
bleaching  calicoes  for  the  use  of  the  printer  shall 
have  attained  that  degree  of  perfection  of  which 
many  other  arts  can  already  boast. 


ON    ULEaCHING. 


325 


AVhen  the  process  of  bleaching  by  chlorine  was 
first  practised,  the  art  of  calico  printing  may  be  said 
to  have  been  in  its  infancy,  and  consequently  very 
little  variation  was  then  made  in  the  operation  of 
bleaching  the  brown  pieces,  whatever  might  have 
been  the  style  of  work  for  which  they  were  intended. 
When  the  competition  was  less,  the  perfection  of 
bleaching  was  comparatively  of  small  importance. 
Out  now  the  case  is  materially  altered,  and  all  the 
best  printers  know,  that  the  common  routine  of  pro- 
cesses, and  such  as  I  have  described  at  page  3 1 S,  is 
insuBicient  for  bleaching  calicoes  which  are  design- 
ed for  best  madder-work.  The  common  mode  of 
bleaching  is  not  sufficient,  because  goods  so  treated 
are  never  fully  bleached  internally;  and,  therefore, 
when  they  come  into  the  madder-copper,  the  re- 
maining impurities  will  in  some  measure  rise  to  the 
surface,  and  there  becoming  a  mordant  for  the  mad- 
der, will  occasion  those  parts  of  the  cloth,  which 
were  intended  to  be  preserved  white,  to  acquire  an 
indelible  stain,  or  at  least  will  inevitably  produce 
what  are  called  dull  whites. 

To  remedy  this,  nothing  will  prove  effectaal,  I 
suspect,  but  to  increase  the  number  of  the  opera- 
tions, as  mentioned  above,  and  to  conduct  every 
process  with  the  strictest  regard  to  cleanliness,  and 
to  the  purity  of  the  articles  employed.  Here  I  had 
more  particularly  in  mind  the  practice  of  using  old 
dirty  alkaline  solutions  ;  but  it  will  also  be  equally 
impossible  to  produce  fine  bleaching  where  the 
goods,  at  all  times  of  the  year,  can  be  washed  odIjt 


326  as  BLEACHING. 

in  a  rim ;'  becaiise  in  time  of  flood  the'  water  UnSi 
be  eharged  with  calcareous  earthy  which  aftervaidii 
when  they  are  immersed  in  the  snlphmic  Actd,  nA 
lorm  an  insolable  selenite  within  ihe  porea  of  tbk 
doth.  Although  there  is  an  evident  impropcielf  m 
using  waste  lyes,  or  such  as  had  before  been  em^ 
ployed  in  any  cleansing  process^'  the  most  cirenfii^ 
spect  manufacturers,  for  common  work  or  in  what 
they  call  surface  bleaching,  do  often  boil  sudi  goodi 
in  a  lye  which  had  been  used  before  in  some  of  the 
latter  processes  of  the  finest  bleaching. 

Having  had  reason  to  conclude  that  many  of  die 
Scotch  printers  are  already  aware  of  this,  because! 
know  that  a  great  deal  of  very  excellent '  bleaching 
is  accomplished  in  Scotland,  I  have  procured  from 
a  scientific  printer  ih  that  part  of  the  kingdom,  an 
6xact  account  of  the  plan  he  pursues  whenever,  he 
bleaches  calicoes  for  madder-work,  or  resist-woik, 
or  for  the  fine  pale  blue-dipping,  and  which  he  as^ 
sures  me  I  may  recommend  with  confidence.  'The 
following  concise  outline  of  the  process  will,  I  trd^ 
be  sufficiently  explicit  to  be  understood  by  iiof 
practical  man. 

The  goods  having  been  singed  and  steeped  in 
pure  water,  as  is  customary  in  common  bleaching, 
they  are  passed  through  a  pair  of  rollers  to  press 
out  the  impurities  which  have  been  loosened  by  the 
steeping.  It  must  here,  however,  be  observed, 
that  where  the  expense  of  one  extra  dyeing  catfbe 
afforded,  the  process  might  be  very  mufch  improved 
by  stewing  the  brown  calicoes  for  thirty  or  kttf 


ON  BLKICUING.  32/ 

houis  before  singeing,  because  this  would  separate 
mnch  of  that  impurity  which  usually  becomes  fixed 
in  the  stuff  on  its  being  passed  over  the  hot  cy- 
linders. WTien  the  pieces  have  been  tlius  singed, 
steeped,  and  pressed,  tbey  are  boiled  four  times,  ten 
or  twelve  hours  at  each  time,  in  a  solution  of  caustic 
potash,  of  the  sperific  gravity  of  from  I '0127  to 
1*0 166,  washing  them  carefully  and  thoroughly  in 
pure  water  between  each  of  these  boilings.  They 
are  then  immersed  in  a  solution  of  the  chloride  of 
potash,  originally  of  the  strength  of  1'0625,  and 
afterwards  reduced  with  twenty-four  times  its  mea- 
sure of  water.  The  specific  gravity  of  the  chloride 
of  lime  or  of  potash,  is  not  an  absolute  rule  for  tliia 
determination  of  the  bleaching  power  of  either; 
for,  sometimes  the  specific  gravity  will  be  what  it 
ought  to  be,  and  yet  the  liquor,  owing  tu  the  impu- 
rity of  the  materials,  will  be  nearly  effete.  For  this 
reason,  the  solution  of  indigo  is  generally  employed 
to  ascertain  the  goodness  of  all  bleaching  liquors. 
When  the  preparation  is  good,  the  proportions 
mentioned  above  will  whiten  cotton  goods  com- 
pletely in  eight  hours.  In  this  preparation  they  are 
however  generally  sufl'ered  to  remain  twelve  hours. 
It  is  of  importance  to  remark,  that  here  the  common 
bleaching  liquor  (chloride  of  lime)  cannot,  without 
injury,  be  substituted  for  chloride  of  potash. 

Some  printers  take  the  pieces  from  this  solution, 
and,  while  wet,  lay  ihem  on  the  grass,  and  there 
expose  them  to  the  sun  and  weather  for  two  or 
three  days.  From  thence  they  are  removed  to  the 
sours,  made  of  the  specific  gravity  of  about  1  •0254 


328  ON  BLEACHING. 

at  the  temperature  of  110  degree^s  of  Fahrenheit.  In 
bleaching  common  goods,  and  such  as  are  not  de- 
signed for  the  best  printing,  the  specific  gravi^  of 
the  sours  is  varied  from  that  of  1*0146  to  that 
of  1*0238,  if  taken  when  they  become  of  the  tem^ 
perature  of  the  atmosphere.  In  these  they  are 
suffered  to  lie  for  five  or  six  hours,  after  which  tbejr 
are  taken  to  the  wheel  and  washed '  thoroughly. 
When  this  operation  is  finished,  they  are  submitted 
to  four  more  boilings  as  before,  with  a  solution  of 
caustic  potash ;  taking  care  to  wash  well  betweenr 
each  of  these  boilings.  Somttimes peari-ash^  made 
caustic,  is  used  for  the  last  of  these  boilings,  lest 
the  sulphur,  which  always  exists  in  the  potaah  of 
comnierce,  should  impair  the  whites.  They  are 
then  immersed  in  the  diluted  chloride  of  potash,  of 
the  strength  before  mentioned ;  after  which,  tbcjl^ 
are  well  washed  in  pure  water,  and  then  wiocbecl 
for  half  an  hour  in  common  sours.  The  last  prot 
cess  is  that  of  careful  washing  in  plenty  of  clean 
water,  after  which  they  are  not  put  into  the  stove, 
but  are  immediately  hung  up  in  the  airing  sheds  to 
dry  gradually.  I  know  several  print-works  where 
it  would  be  impossible  to  produce  fine  bleaching 
because  they  are  not  supplied  with  a  sufficieAGy. 
of  water.  For  this  purpose  the  water  must  be 
good,  and  there  ought  to  be  plenty  of  it, at  all 
seasons. 

The  number  of  operations,  as  here  described,  is 
great ;  but  I  know  of  no  other  mode  of  procedure 
by  which  perfect  bleaching  is  so  likely  to  be  effected 
at  all  times  and  in  all  seasons,  without  disappoints^ 


ON  BtEACHlNG.  329 

tnent  It  must  here  be  remarked,  that,  for  the  best 
purposes  of  printing,  it  would  not  be  sufHcient  to 
take  goods  which  have  been  bleached  in  the  common 
way  and  finish  these  by  the  better  process;  because 
the  selenite  deposited  in  the  cloth  by  that  opera- 
tion, will  for  ever  spoil  them  for  madder  colours ; 
at  least,  a  printer  who  is  curious  in  his  work  would 
not  dare  to  use  such  for  those  purposes. 

I  have,  however,  been  informed  that  the  proprie- 
tors of  some  of  the  Scotch  establishments  still  per- 
sist in  bleaching  calicoes  without  any  preparation 
of  chloride  whatever ;  and  one  of  the  partners  in  a 
concern  of  considerable  consequence  in  the  county 
of  Chester,  has  also  assured  me  tliat  he  has  always 
eontinued  to  bleach  by  the  old  method  ;  and  that  he 
has  nothing  to  depend  upon  but  the  frequent  repe- 
titions of  the  alternate  processes  of  ashing,  sour- 
ing, and  crofting,  for  the  production  of  good  whites. 
It  nevertheless  appears  to  me,  that  this  must  occa- 
sion great  waste  of  time,  and,  where  the  calicoes 
are  to  be  employed  for  the  best  work,  must  be 
very  uncertain  in  the  result.  Knowing  that  good 
printing  is  regularly  produced  at  this  establishment, 
I  confess  I  do  not  understand  how  the  proprietors 
eontrive  to  succeed  without  the  employment  of  a  so- 
lution of  chloride  of  lime,  or  some  such  substance. 

In  the  Essay  on  Calico  Printing  I  have  already 
remarked  that  the  German  linen  cloth  is  better  than 
the  Irish;  and  yet,  in  consequence  of  the  Irish 
cloth  being  bleached  and  finished  in  a  superior 
manner,  that  this  has  always  the  preference  in  fo- 


330  0»  BLKACHINOfe 

reign  markets.  In  endeavouring'  to  account r  for 
this,  I  apprehend  we  must  look  to  ail  imporfeaat 
tional  institution*  known  by  the  name  of  the 
Board  of  Irelandy  which  has  done  every  thing  in  its 
power  to  improve  the  staple  article  of  the  kiagdomi 
and  has  the  sovereign  controul  in  every  misttar-«H 
bting  to  the  linen  manu&ctiire.  Some  of  their  're- 
gulations deserve  to  be  mentioned. 

In  Ireland,  every  bleacher  must  stamp  bia  amn 
name  on  the  end  of  every  web^;  heace.  it  can 
always  be  ascertained,  by  mere  inspeotion,  ntoa 
the  bleaching  has  been  performed.  Again,  should 
any  goods  be  improperly  bleached,  so  that  the  texr. 
ture  is  injured,  the  bleacher  is  liable  to  be  coni^ 
pelled  to  take  back  the  whole  of  them,  and  f9f 
every  expense  of  carriage,  however  far  they  mwf 
have  been  conveyed  from  the  spot  where  they  were 
finished.  In  this  case  the  bleacher  is  also  subjected 
to  a  considerable  fine.  So  certain  is  the  inflietioii 
of  this  penalty  in  case  of  a  complaint  being  pro* 
perly  lodged  against  a  delinquent,  that  some  years 
ago,  when  the  bleaching  process  was  not  condudsd 
with  that  care  with  which  it  is  at  present,  several  p^« 
sons  actually  travelled  through  many  of  the  coon* 
ties  of  Eingland  and  Scotland  for  the  purptee  of 
collecting  from  the  mercers  all  such  damaged  Irish 
linens,  and  for  which  they  paid  good  prices,  in 
order  to  be  entitled  to  receive  the  fines. 


"^  A  web  is  a  technical  term  among  all  weavers  and  bleacfaeiSi 
both  in  Great  Britain  and  Ireland,  for  a  piece  of  linen  cloth. 


ON  BLBACHING.  SSI 

•The  best  r^ulations  may,  however^  be  super- 
feded  and  often  evaded.  Accordingly  4t  is  well 
known  that  many  hundred  thousands  of  pieces  of 
calicoes  are  made  and  finished  in  Lancashire,  and 
stiffened  in  a  peculiar  way,  to  imitate  the  Irish 
finens,  particularly  those  made  at  Colerain,  and 
that  they  have  the  name  of  this  place  stamped  upon 
them.  Is  not  this  a  proper  subject  for  the  inter- 
ference of  the  legislature?  though  the  Irish,  in 
thdr  turn,  practise,  as  I  understand,  a  similar  de« 
teption  in  the  manufacture  of  thread. 
*«  It  is  notorious  that  a  kind  of  linen  thread  made  at 
Pkdsley,  in  Scotland,  and  known  by  the  name  of 
Nuns-thread,  has  the  preference,  and  is  the  best  for 
use.  In  consequence  of  the  character  which  this 
thread  has  acquired,  the  Irish  have  now  begun  a 
similar  manufacture,  and  scruple  not  to  usher  theirs 
ibtD  the  market  under  the  sanction  of  a  stamp 
bearing  the  name  of  Paisley. 

In  like  manner,  an  article  called  Irkkle^  and  some 
species  of  thread  resembling  that  which  is  made  in 
Holland,  are  now  manufactured  in  large  quantities 
in  Scotland,  and  sold  under  a  Dutch  stamp;  the 
method  of  making  these  articles  having  been  stolen 
from  Holland,  and  brought  into  Scotland  half  a 
eentury  ago.  Thus,  self-interest  is  apt  to  be  the 
leading  motive  with  mankind  in  all  nations. 

In  resuming  the  subject  of  bleaching,  it  will  be 
necessary  to  mention  that  the  chloride  of  soda, 
spoken  of  in  describing  the  mode  which  the  Scotch 
printers  adopt  in  bleaching  calicoes^  is  now  em- 


332  ON  BLEACHING. 

ployed  also  in  clearing  the  whites  of  maddered 
goods^  and  that  this  has  almost  entirely  supcnrseded 
the  operation  of  crofting,  which  was  a  tedious  and 
expensive  process  ^.  The  method  is  to  mix  a  stnaU 
portion  of  the  chloride  of  soda  with  a  large  qoantity 
of  warm  water,  and  then  to  suffer  the  maddered 
pieces  to  lie  in  this  preparation  till  the  grounds  be- 
come perfectly  white. 

This,  which  is  one  of  the  last  improvements  in 
calico  printing,  is  of  very  considerable  importance'; 
for,  the  finest  ginghams,  as  they  are  called,  and 
the  most  expensive  chintz  work,  which  contun  t 
variety  of  very  delicate  colours,  and  formerly  re- 
quired  many  weeks  exposure  on  the  grass,  can  now 
be  cleansed  in  a  few  hours,  so  as  to  produce  the 
most  perfect  whites,  without  impairing  any  of  the 
colours  themselves. 

In  conducting  this  process^  it  is  of  the  utmost 
consequence  to  attend  to  the  precise  strength  of  the 
preparation  of  chlorine^,  that  it  may  be  strong 
enough  to  clear  the  whites  completely,  and  yet  in- 
capable of  discharging  or  impairing  any  of  the 
printed  colours.  This  is  usually  ascertained  by 
means  of  a  very  dilute  solution  of  sulphate  of  in- 
digo, prepared  in  the  following  manner. 

One  pound  of  the  best  Spanish  indigo  that  can 

^  This  application  of  the  chloride  of  soda  has  already  been 
slightly  mentioned  in  vol.  i.  page  284^  and  at  page  304  of  this 
volume. 

^7 1  have  procured  a  drawing  of  one  of  the  most  approved  of 
the  apparatus  now  employed  for  making  the  chloride  of  aoda 
for  this  particular  purpose.    See  Plate  20. 


ON  OLEACHIMG.  ^33 

be  procured,  is  to  be  ttlssolved  by  the  usual  metliod, 
in  four  pounds  ol*  concentrated  sulphuric  acid. 
Tliese  proportions  will  generally  saturate  each  other. 
When  the  whole  of  the  indigo  is  dissolved,  one 
part  by  mwisure  of  this  sohitlon  is  to  be  diluted 
witli  sixteen  parts  by  meiisure  of  water,  and  then 
it  will  be  fit  for  use.  To  obviate  any  deception 
wtiich  might  arise  in  case  of  a  difference  in  the 
quality  of  the  indigo,  it  is  always  best  to  preserve 
some  of  the  old  solution,  and  then,  having  com- 
pared the  new  with  this,  to  alter  the  proportion  of 
water  a  little,  if  this  be  found  necessary.  Tlie 
quantity  of  water  which  is  employed  in  diluting  the 
solution  of  indigo  is  not  very  material,  provided  the 
operator  accustoms  himself  to  the  use  of  one  cer- 
tain determinate  proportion;  and  indeed  this  test 
is  used  of  various  degrees  of  strengtli  according  to 
the  fancy  of  different  printers ;  but  one  printer 
should  always  use  it  of  one  particular  strength. 

The  object  in  making  this  preparation  is  to  have 
a  standard  always  at  hand,  by  which  the  printer 
can  with  precision  ascertain  the  exact  strength  of 
any  of  his  bleaching  Hquor ;  and  this  is  always 
to  be  determined  by  the  quantity  of  it  that  is  re- 
quired to  destroy  the  colour  of  any  given  portion  of 
the  test,  or  vice  versa. 

In  employing  this  reagent,  it  is  customary  to 
have  two  long  graduated  glass  tubes,  in  one  of 
which  the  diluted  sulphate  of  indigo  is  put,  and  in 
the  other  tlie  bleaching  liquor.  By  gradually 
pouring  some  of  the  former  tuto  the  latter,  it  is 


334  ON  BLEAGftIN6^. 

immediately  seen  how  much  of  the  coloured  test  is 
destroyed,  by  a  given  number  of  parts  of  the  pre* 
paration  of  chlorine.  This,  however,  for  the  lea* 
sons  already  adduced  ^,  is  not  a  sufficient  test  tX 
itself  for  ascertaining  the  goodness  of  a  bleaching 
liquor  without  attending  also  to  its  specific  grai^ty. 

BerthoUet  has,  indeed,  said  that  Mr.  Watt  had 
told  him  that  the  indigo-test  will  not  accurate)^ 
show  the  strength  either  of  chloride  of  soda  or  pot- 
ash ;  and  he  also  adds,  that  a  decoction  of  cochi- 
neal is  a  better  test,  for  that  it  completely  answcM 
every  purpose,  and  is  not  liable  to  occasion  any 'dif^ 
ception.  I  know  not,  however,  on  what  princtpfc 
this  opinion  is  founded. 

While  speaking  of  tests,  it  may  perhaps  be  worth 
while  to  mention,  that  this  same  eminent  chenml 
has  proposed  the  bleaching  liquor  itself  as  a  useful 
test  for  proving  the  goodness  of  colours  on  printed 
calicoes.  By  taking  a  shred  from  the  piece  of  c«* 
lico  intended  to  be  tried,  and  another  shred  of  a 
similar  colour  from  a  piece  known  to  be  printed 
with  /ast  colours,  and  then  putting  both  pieces  at 
once  into  a  preparation  of  chlorine,  it  will  soon  b^ 
seen  which  pattern  can  best  resist  the  power  of  tb6 
bleaching  fluid.  ' 

The  compressed  steam  of  boiling  water  has  beeit 
lately  employed  instead  of  chlorine  in  bleacfaiDg 
cottons.  It  is  said  that  this  method  of  bleaching 
has  long  been  practised  in  some  parts  of  the  Ea^t! 

•*  Sec  page  297  of  this  volume. 


ON  BLBACHINQ,  338 

Chaptal  was  the  first  writer  who  recommended  it 
to  the  European  bleacher  %•  By  the  continued  and 
alternate  immersion  of  cotton  goods  in  an  alkaline 
liquor,  and  the  exposure  of  them  to  the  action  of 
the  vapour  arising  from  the  same  lixivium  when 
heated  to  22(f  or  230^  the  goods  are  said  to  be 
whitened  very  effectually  without  the  fttbric  sus^ 
tuning  any  injury.  The  resinous  and  other  co- 
louring matter  of  the  cloth,  which  is  insoluble  in  a 
dilute  solution  of  alkali  at  the  temperature  of  boil- 
ing water,  becomes  soluble  in  this  menstruum, 
when  heated  a  few  degrees  beyond  that  point.  The 
operation  consists,  first,  in  immersing  the  goods  in 
the  alkaline  lixivium,  and  then  exposing  them  to 
the  heated  aqueous  vapour ;  and  these  methods  are 
pursued  alternately  till  the  whitening  is  completely 
attained. 

This  mode  of  bleaching  linen  goods  has  been 
adopted  in  France  for  domestic  washing.  Chaptal 
tried  it  on  200  psur  of  sheets  belonging  to  the  hos-* 
pital  of  the  Hotel-Dieu  of  Paris,  with  the  utmost 
raocess.  The  linen  was  perfectly  cleansed,  and  the 
expense  was  reduced  in  the  proportion  of  four  to 
aeven  ^.  I  have  had  no  opportunity  of  observing 
the  effect  of  this  process  myself:  but  I  can  easily 
eonceive  that  a  superior  temperature  may  be  of 


r 

^  See  his  Chemistry  applied  to  the  Arts,  vol.  iii.  p.  100. 
Ddam^therie  also  wrote  a  memoir  upon  it  in  the  Journal  de 
Physique  for  the  year  1801,  at  p.  305,  of  which  some  account 
maybe  seen  in  Nicholson's  4to  Journal,  toI.  iy.  p.  469. 

^  For  the  details  see  Annates  de  Chimie,  tome  xxxviii.  p.  29 1 . 


336  ON  BLEACHING. 

service  in  bleaching  7i,  because  I  have  noticed  that 
when  brown  calicoes,  which  have  undergone  only 
one  boiling,  have  lain  all  night  in  the  kier,  or  whale 
boiler  7S,  those  parts  of  the  pieces  which  had  been 
in  immediate  contact  witli  the  iron  fountain^  stand- 
ing in  the  middle  of  the  apparatus,  were  quite 
white,  while  the  others  were  very  little  improved  in 
colour  by  the  operation.  This  I  attribute  to  the 
lengthened  continuance  of  a  high  temperature,  a^  a 
great  degree  of  heat  is  always  communicated  to  the 
middle  of  the  vessel,  by  the  constant  circulaUon  of 
the  boiling  liquor  through  the  fountain,  the  metallic 
part  of  which,  at  times,  may  perhaps  exceed  the 
temperature  of  2 1 2^. 

The  bleaching  of  linen  and  cotton  goods  by 
means  of  compressed  steam,  will  however  be  always 
attended  with  some  difficulty  on  account  of  the 
danger  of  the  bursting  of  the  apparatus  by  the 
force  x)f  the  coniin.ed  vapour,  if  the  valves  should 
ever  be  improperly  loaded:  but,  notwithstanding 
this  objection,  it  appears  to  me  that  the  practice 
deserves  further  investigation  ;  for  it  would  doubt- 
less be  a  great  advantage  to  the  arts,  if  it  were  pos^ 
sible  to  bleach  our  manufactured  goods  in  as  short 
a  time  as  they  are  at  present  finished,  and  yet  save 
the  expense  of  chlorine  altogether.  The  apparatus 
employed  for  this  purpose  in  Great  Britain  is  gene- 

71  SeTeral  instances  of  changes  produced  by  alteration  of 
temperature  may  be  seen  in  Essay  II.  vol.  i.  page  176 — 194. 

^  For  an  explanation  of  the  nature  of  this  apparatUM  see  tlie 
description  of  the  plates  which  accompany  this  volume. 


ON  BLEACHING.  '83^ 

tally  made*  with  large  slabs  of  stone  mmped  toger 
ther  with  iron^  and  sufficientlj  massy  to  sustain  the 
eflects  of  great  pressure  ^\ 

It  was  originally  my  intention  to  haveofiered 
wme  remarks  on  the  methods  of  bleaching  wool 
.and  woollen  goods^  silk,  bees-wax,  writing  paper^ 
books,  prints,  &c. :  but  as  the  Essay  has  already 
exceeded  its  prescribed  bounds,  I  must  content 
myself  by  merely  referring  the  reader  to  the  sources 
from  whence  he  may  obtain  some  information  oo 
these  subjects. 

Wool  has  usually  been  bleached  by  the  fumes 
arising  from  the  slow  combustion  of  sulphur,  an 
jurticle  which  was  employed  sixteen  hundred  yean 
.ago  for  the  same  purpose  It  has,  however,  been 
found  that  this  mode  only  whitens  the  surface  of 
the^  goods :  therefore,  of  late  years,  recourse  has, 
in  some  instances,  been  had  to  the  liquid  sulphu- 
rous, acid,  which  bleaches  wool  more  effectually 
than  that  acid  does  when  in  a  gaseous  state.  Some 
account  of  the  usual  process  by  the  means  of  sulphu- 
rous acid  gas,  may  be  seen  in  Pajot  Des  Charmes* 
Art  of  Bleaching,  translated  by  Nicholson,  -  8vo. 
London,  1799,  page  28U  The  burning  of  brim- 
atone  in  atmospheric  air  is  called  the  slow  com- 
bttition,  in  opposition  to  the  burning  it  in  oxy- 
gen gas,  or  by  the  mixture  of  nitre ;  but  Stahl  has 
shown  that  in  bleaching  woollen,  the  slower  the 

^*  An  ample  description  of  that  used  in  France  may  be  seen 
b  a  work  by  M.  D'Orelly,  entitled  "  Es$n%  tur  le  BUinckiment;' 
sold  by  Deterville,  Paris. 

VOL.  II.  Z 


336  ON  BLBACfilNC^. 

sulphur  is  burnt,  the  more  eflfect  will  it  produce. 
Apuldus,  who  lived  in  the  time  of  the  Antoninet, 
tdls  an  anecdote,  in  the  romance  of  the  Golden 
Ass,  of  a  man  who  had  an  illicit  amour  being  nearly 
suflbcated  at  the  house  of  a  faller,  by  having  ISA 
lumself  under  a  wicker  coop  which  had  been  enn 
ployed  to  whiten  cloth  by  the  fumes  of  burning  sul- 
phur ''*.  It  appears  from  this  story,  that  the  andent 
fullers  bleached  thdr  woollen  cloths  by  hanglog 
them  round  an  apparatus  made  of  wicker  work,  and 
then  setting  fire  to  a  portion  of  sulphur  placed  un- 
derneath it.  Messrs.  Roland,  Laplatiere  and  Alhrd, 
who  were  general  inspectors  of  manufoctures  in 
France,  published  several  memoirs  on  the  Ueadnng 
of  wool,  and  the  above  account  by  Charmes  appeals 
to  have  been  taken  from  these  papers. 

In  bleaching  bees-wax  the  following  is  the  pnh 
cess,  as  it  is  usually  conducted  in  England.  Com- 
mon bees-wax  is  melted  upon  hot  water ;  and  whtt 
in  a  fluid  state,  it  is  laded  out  of  the  copper,  toge- 
tlier  with  a  part  of  the  water,  into  a  wooden  vesseli 
and  in  this  it  is  allowed  to  remain  a  few  hours  far 
the  impurities  to  subside  from  it.  The  purified  wax 
is  then  put,  while  still  hot,  into  a  cullender  full  of 
holes,  through  which  it  runs,  and  falls  upon  a  re- 
volving metallic  roller,  which  dips  into  cold  water 
contained  in  a  vessel  placed  underneath.  As  the 
melted  wax  runs  through  the  cullender  upon  the 
revolving  roller,  the  motion  of  the  cylinder  forms  it 


'^  See  book  ix.  p.  136,  edit.  Scrivenii,  Amst.  1624. 


ON  BLEACHING.  339 

into  thin  shavings,  which  cool  as  they  come  in  con- 
tact with  the  water,  and  fall  in  an  accumulated  heap 
into  the  water  below.  These  slmvings  of  wax  being 
now  in  a  suitable  form  for  absorbing  oxygen,  they 
are  taken  out  of  the  tub,  and  exposed  in  a  field  to 
tlie  action  of  the  atmo&phere  till  they  become  suffi- 
ciently white. 

A  memoir  by  Baum^  on  the  bleaching  of  silk  will 
be  found  in  Nicholson's  4to  Journal,  vol.  i.  pp.  32 
and  88.  This  memoir,  which  is  extremely  interest- 
ing, was  first  published  in  the  Journal  de  Physique  ". 
The  method  consists  in  digesting  the  silk  in  a  large 
quantity  of  spirit  of  wine  previously  mixed  with  a 
few  ounces  of  muriatic  acid.  Some  account  of  the 
bleaching  of  bees-wax  may  be  seen  in  Fourcroy's 
System  of  Cliemisiry "'. 

The  specifications  of  several  patents  which  have 
been  obtained  of  late  years  for  divers  modes  of 
bleaching  paper,  may  be  read  in  the  Repertory  of 
Arts  :  and  ample  directions  for  bleaching  oM  cop- 
per-plate engravings  and  old  printed  books,  will  be 
found  in  Cliaptal's  System  of  Cliemistry  applied 
to  the  Arts,  or  in  the  English  translation  of  that 
work  ".  A  memoir  by  Loysel  on  the  bleaching  of 
pulp  for  making  paper  may  be  seen  in  the  Annates 
de  Chiraie". 

Sig.  Fabbroni,  Superintendant  of  the  Royal  Ca- 
binet of  the  Grand  Duke  of  Tuscany,  communi- 

«  Tome  xlii.p.375— 39!), 

"  VoL  X.  p.  483,  and  in  Chnnnei,  p,  207. 

"  Cliaptul,  vol.  iii,  p.  108. 


340  ON  BLEACHIKG. 

cated  to  Dr.  Duncan,  jun.;  of  Ediiihurgh,;  A^  ytrf 
simpte  and  ingenious  mode  of  bleaching  old  printSp 
which  may  be  found  in  Nicholson's  4to  Jourajal; 
vol.  ii.  p.  265.  Chaptal  presented  an  Essay  on  this 
subjfetet  to  the  Academy  of  Montpellier,  and  this 
was  afterwards  published  in  the  Memoirs  of  the 
Royal  Academy  for  the  year  }  787.  The  Repott 
of  Messrs.  Lavoisier  and  BerthoUet  on  this  piper 
may  also  ^  seen  in  the  Annales  de  Chimiey  tome 
i.  p.  69. 

Th^  art  of  bleaching  has  also  been  introduced  i|f 
late  years  into  the  straw  manufactory.  The  ntti- 
nufacture  of  straw  into  the  form  of  hats  for  f^maki 
has  become  very  considerable^  and  consequ<ently  ifla- 
portant,  especially  as  it  gives  employment.to  a  vefy 
great  number  of  the  children  of  the  poor*  I  have 
not  yet  learned  the  methods  employed  for  biaidi- 
ing  the  straw  when  it  is  intended  for  whiie  hats, 
but  a  friend  of  mine  has  assured  me  that  the  smi* 
phurous  acid  is  employed.  This  acid  is  very  effise- 
tual  for  the  removal  of  fruit  stains  from  linen  or 
cotton  garments.  All  that  is  necessary  is 'first  .to 
damp  the  places  thomughly,  and  then  to  bum  two 
or  three  common  brimstone  matches  close  to  them. 
The  gas  from  the  sulphur  will  combine  with  the 
water  and  form  sulphurous  acid,  which'  will  rtty 
soon  occasion  the  spots  to  disappear. 

The  chlorides  have  also  been  applied  to  this  pur- 
pose»  but  they  are  said  to  weaken  the  vegetable 
fibre.  This,  however,  must  be  owing,  as  I  imagine, 
to  their  being  employed  in  too  concentrated  a  state. 


ON   BL£ACHING.  341 

I  have  now  only  to  make  a  few  desultory  obser- 
vations which  I  conceive  may  be  useful,  and  with 
these  1  shall  close  the  Essay. 
.  In  a  large  bitching  establishment  it  is  of  great 
importance  to  knowliow  to  procure  manganese  of 
the  best  quality.  There  are  several  mines  of  this 
mineral  in  various  parts  of  these  islands;  but  I  know 
of  none  equal  to  that  which  is  raised  at  Upton  Pine, 
in  the  county  of  Devon.  Most  other  kinds  are  of 
little  value  to  the  bleacher,  inasmuch  as  they  require 
-m  larger  portion  of  sulphuric  acid  and  yet  produce 
less  oxygen.  Even  the  manganese  from  Upton  Pine 
IB  of  various  qualities.  That,  however,  which  con- 
tains the  largest  proportion  of  the  crystallized  oxide 
}b  generally  to  be  preferred. 

Being  desirous  of  obtaining  the  best  information 
TCspecting  manganese,  I  took  an  opportunity,  in  the 
year  1810,  of  visiting  this  celebrated  mine,  where, 
from  the  proprietors  themselves  and  from  some  of 
the  intelligent  inhabitants  of  the  neighbourhood,  I 
learnt  several  particulars  which  may  be  worth  re- 
cording. 

This  mine  is  situated  between  the  two  turnpike 
iQBils  from  Exeter  to  South  Moulton,  and  from 
Exeter  to  Crediton,  and,  as  far  as  I  could  collect, 
had  then  been  worked  about  forty  years ;  though  at 
Unt  the  quantity  of  the  manganese  that  was  raised 
was  small,  as  it  was  then  employed  only  in  the 
•manufacture  of  glass,  and  in  some  processes  in  the 
Stpiffordshire  potteries.  This  mine,  which  produces 
the  best  oxide  of  manganese  that  has  ever  been  raised 


342  ON  BLEACHIN«^ 

in  these  idngdoim,  was  aoddentally  discovefed  by  a 
person  passing  along  the  road ;  as  the  nuneral  oA' 
ginally  came  out  at  the  sur&oe  of  the  ground,  and 
the  roads  in  the  neighbourhood  were  occasionaBy 
repaired  with  it.  The  mine  is  on  the  estate  of.  Sir 
Henry  Starford  Northcote,  Bart,  of  Pines-Jioose ; 
and  I  learn  that  the  first  persons  who  occaAmedjt 
to  be  worked  were  Nicholas  Williams  and  ZaofaK- 
riah  Kangdon,  of  the  dty  of  Exeter,  Esquires,  who 
turquired  much  wealth  by  the  profits  of  theundei^ 
taking.  Both  these  gentlemen  being  since  dead, 
and  the  lease  having  expired,  the  mine  is  come  into 
other  hands,  and  the  sum  piud  per  ton  for  the 
royalty  b  very  much  advanced. 

Some  thousand  tons  of  manganese  and  loose  earth 
having  been  removed,  the  mine  is  now  in  sudi  a 
state  as  to  allow  persons  to  descend  into  it  by  a  wind- 
ing path  cut  within  the  hill,  and  which  conducts  to 
the  foot  of  a  perpendicular  rock  fifty  feet  high. .  The 
entrance  into  that  part  of  the  mine  which  is  now 
worked  is  through  an  archway  cut  in  the  fece  of  this 
rock.  An  immense  quantity  of  manganese  having 
been  raised  since  this  entrance  was  made,  the  exca- 
vations are  now  of  considerable  extent,  the  upper 
ground  being  supported  by  large  masses  of  manga- 
nese which  are  left  for  pillars.  Here,  by  help  of  a 
pick-axe,  I  broke  off  some  fine  specimens  of  the  lu- 
neral. 

At  some  distance  from  the  entrance  of  whidi  I 
have  been  speaking,  two  shafts  are  sunk  of  the  depth 
of  fifty  feet  each,  which  lead  to  the  lowest  part  of 


ON  BLEACHING.  M6 

the  mine,  and  winch  I  was  desirous  of  exploring, 
as  I  could  distinctly  hear  the  men  at  work  under  my 
feet :  but  being  told  that  I  could  not  descend  with- 
out being  thoroughly  wet,  and  having  no  dress  with 
tne  6t  for  the  undertaking,  I  was  induced  to  decline 
the  offer  which  the  superintendant  made  of  accom- 
panying me,  In  order  to  drain  the  mine  as  well  as 
possible,  without  an  engine,  they  sink  as  low  as  they 
can  in  the  first  instance,  and  then  work  upwards  to 
get  the  mineral.  The  part  which  I  explored  is  50 
feet  below  the  surface  of  the  ground,  and  the  part 
they  were  then  working  is  50  feet  lower  still. 

The  captain  of  the  works  informed  me  that  the 
load  runs  north-east  and  south-west;  and  from  his 
account  I  calculate  that  it  dips  regularly  at  an  angle 
of  40  degrees.  In  some  places  the  vein  is  twelve 
feet  thick,  in  othera  nut  more  than  two  feet.  The 
capel,  as  they  call  it,  which  covers  the  mineral,  is  a 
bard  rock  composed  of  a  mixture  of  sand,  red  clay, 
and  manganese.  Notwithstanding  the  increased  de- 
mand for  the  oxide  of  manganese,  for  the  purposes 
of  bleaching,  it  seems  likely  that  this  single  mine 
may  be  capable  of  supplying  the  whole  island  for  a 
century  yet  to  come. 

It  is  usual  with  the  bleacher,  to  cast  away  the  re- 
siduum ofthe  stills  as  a  worthless  article;  but  surely 
if  some  competent  person  were  employed  to  sepa- 
rate the  sulphate  of  manganese  from  the  sulphate 
of  soda,  and  this  were  done  on  the  spot  where  the 
residuum  is  produced,  the  alkaline  sulphate  would 
be  productive  of  considerable  profit.    In  Uke  man- 


344  ON  bleaching; 

ner  might  the  waste  solations  of  chlorine  be  turned 
to  a  good  account.  The  discovery  of  Hnmboldt, 
that  a  weak  solution  of  such  preparations  has-  the 
property  of  accelerating  and  enlarging  the  growth' 
of  v^etilibles,  I  have  already  nbticed  under  the  ar^ 
tide  Chlorine  in  The  Chemical  Catechism^  1  Otb 
Edition^  chap.  vK.  page  153 ;  and  I  am  noWanidous 
to  remark,  that  gardeners  whose  grounds  are  in  the 
neighbourhood  of  bleach-fields,  would  do  well  io 
availing  themselves  of  all  the  advantages  their  situa* 
tion  affords  them  for  making  experiments  on  •  this 
interesting  and  important  subject.  BerthoUet,  in 
the  memoir  already  mentioned,  observes,  that  he 
had  himself  abstracted  the  soda  from  this  residuuitii 
but  that  he  could  not  explain  the  methods  because 
they  were  confided  to  him  as  secrets.  Whatever 
difficulties  may  attend  the  production  of  soda  from 
this  refuse,  surely  sulphate  of  soda  might  be  easily 
separated  from  it,  and  this  would  always  meet  a 
ready  sale  under  the  name  of  Glauber's  salt. 

Since  writing  the  above,  I  have  been  introduced 
to  a  gentleman  resident  in  the  midst  of  the  Lanca* ' 
shire  bleachers,  who  has  constructed  a  large  appa- 
ratus consisting  of  boilers  and  crystallizing  vessels, 
for  purifying  this  residuum,  and  has  completely  suc- 
ceeded in  procuring  from  it  many  tons  weight  of 
very  fine  Glauber's  salt.  Government  has  however 
lately  forbidden  the  sale  of  the  residuum  ;  and  con«  * 
sequently  this  extensive  apparatus  is  become  useless. 

A  very  worthy  company  of  Scotch  bleachers  with 
>vhotn  I  am  acquainted,  and  who  have  built  several 


ON  ^leaching;  34 £► 

hundred  cottaged  on  their  estate  for  the  use  of  their 
wminnen  and  their  families^  have  occasionally  put 
thiaresiduum  to  the  following  valuable  purpose, 
which  merits  public  attention'. 
•  Whenever  there  is  an  appearance  of  fever  in  lanjr 
one-of  thiese  houses,  one  of  the  managers  orders  the 
whole  of  the  family  out  of  it ;  and  then  placing  a 
pan  containing  a  portion  of  this  residuum,  recently 
ttken  from  one  of  the  stills,  over  a  chafing-dish  of 
burning  charcoal  in  the  middle  of  one  of  the  lower 
ntoms,  he  shuts  up  the  house,  that  every  part  of  it 
nday  be  completely  filled  with  the  chlorine  gas,  which 
th^  heat  separates  from  these  materials,  and  which 
quickly  neutralizes  or  destroys  all  the  putrid  miaa- 
ntata^  and  renders  the  habitation  perfectly  safe  and 
wholesome.  This  practice  has  been  adopted  for  the 
last  twenty  years,  and  during  the  whole  of  this  time 
there  has  been  no  virulent  or  infectious  fever  in  iany 
family  belonging  to  the  manufactory  '^ 

.  la  resuming  the  subject  of  bleaching,  it  is  ne-> 
oessary  to  remark,  that  too  much  attention  cannot 
be  pcdd  to  the  method  of  ascertaining  the  strength 
of  the  bleaching  liquid.  I  have  reason  to  believe 
that  many  bleachers  rely  solely  on  the  evidence 
which  the  specific  gravity  affords  them,  for  any 
knowledge  they  obtain  of  the  goodness  of  their  pre- 
parations of  chlorine.  I  would  therefore  once  more 
warn  these  people  against  such  reliance,  and  again 

^  See  a  Report  on  the  Construction  of  Mephitic  Engines 
W  the  Annalct  de  Cfwnie,  vi.  page  86-*-120. 


% 


346  ON  BLBAC0IN0, 

urge  the  neoessity  of  having  recouiw  to  thd  Smm 
blue,  already  recommended*  or  to  some  other  ib- 
fidliUe  test  in  addition  to  the  proof  afforded  by  At 
spedfic  gravity ;  it  being  impoBuble  ever  to  aoqitite 
a  suflBdent  knowledge  of  the  real  bleaching  pMer 
of  the  Uquid,  without  employing  both  these 
^ods  in  conjunction,  •  • 

In  bleacliing  with  chlorine,  it  is  also  of 
quence  to  expose  all  the  surfaces  equally,  aad  in 
proper  succession;  for,  when  the  goods  lie  one 
upon  anodier,  the  gas  does  not  properly  peneknle 
them,  and  they  are  never  uniformly  bleached: 
whereas,  in  the  bucking  process,  with  the  solutifNi 
of  potash,  they  are  disposed  as  it  were  in  masaetof 
a  considerable  thickness,  and  the  operation  still 
goes  on  well.  It  was  probably  the  knowle^^e  af 
this  circumstance  which  has  induced  many  Ueadiors 
to  have  their  vessels  constructed  very  broad  and 
shallow;  but  this  has  occasioned  another  very  se- 
rious inconvenience.  The  chlorides  being  moie 
liable  to  lose  the  chlorine  the  greater  the  surCsoe  of 
the  apparatus  be  in  which  the  liquors  are  expoaed, 
it  is  more  difficult  for  the  men  to  secure  themsdves 
from  injury,  and  the  waste  is  much  more  conrider- 
able.  Where  there  is  a  contrivance  for  exposing 
all  the  surfaces  equally  to  the  action  of  the  bleach- 
ing liquor,  the  deeper, the  vessels  are  in  comparison 
of  their  diameter,  the  better  will  they  be  adapted  to 
convenience  and  economy. 

It  is  also  important  to  rinse  the  goods  imme- 
diately after  they  come  out  of  the  alkaline  liquet. 


ON  BLEACHING.  347 

It  is  no  unusual  thing  for  the  manufacturer  to  al- 
low them  to  lie  in  heaps  for  a  considerable  time  be- 
fore washing.  But  this  I  conceive  to  be  a  bad 
practice ;  for  while  the  goods  are  warm  the  pores 
nre  open,  and  the  Blth  which  has  been  loosened  by 
the  recent  action  of  the  alkali,  will  be  more  effec- 
tually removed  by  washing  immediately  than  if  they 
be  allowed  to  lie  till  they  become  cold. 

In  order  that  no  waste  of  alkali  should  arise  in 
the  process  of  boiling  or  bucking  the  calicoes,  it  has 
been  customary  with  many  persons  to  use  the  lyca 
a  second  and  a  third  time,  as  stated  at  pages 
313  and  322,  and  often  to  the  great  injury  of  the 
goods  which  are  so  treated.  Instead  of  this,  I 
would  advise,  that  all  such  impure  lyes  should  be 
concentrated  by  evaporation,  and,  when  of  a  due 
consistence,  removed  from  the  evaporating  pan  to 
the  floor  of  a  small  reverberatory  furnace  similar  to 
tlioae  described  in  the  plates,  and  mentioned  in  the 
note  vol.  ii.  page  69.  Where  there  is  a  conve- 
nience for  fully  concentrating  such  waste  lyes  by 
evaporation,  a  common  baker's  oven  might  be  em* 
ployed  for  the  subsequent  calcination,  provided  the 
precautions  were  taken  in  heating  it  which  are  ad- 
vised by  Pajot  des  Charmes,  p.  67  of  liis  well- 
known  work  on  this  subject.  In  such  a  furnace 
they  would  easily  be  purified,  because  a  gentle  cal- 
cination would  burn  the  colouring  matter  and  re- 
store the  alkali  to  its  original  state.  In  districts 
where  coal  can  be  had  cheap,  and  the  consumption 
of  alkali  is  considerable,  this  would  be  a  very  eco- 
nomical process. 


348  ON  BLSAGHING/ 

Nothing  now  remains  but  to  redeem  the  pledge 
which  I  gave  at  page  3 12,  to  offer  a  few  remarks  oil 
the  introduction  of  the  blue  and  red  stripes,  which 
are  often  seen  at  the  top  of  cotton  hose.  But  these 
remarks  must  be  very  brief. 

Since  the  introduction  of  chlorine  in  the  process 
of  bleaching  hose,  at  least  since  its  nature  and  ope^ 
ration  have  been  so  well  understood,  the  caiefbl 
bleacher  is  under  no  apprehension  of  injuring  the 
articles  which  are  committed  to  his  care,  and  hak 
no  difficulty  whatever  in  ascertaining  the  real  quan- 
tity that  may  be  absolutely  necessary  for  the  bleach- 
ing of  any  particular  parcel  of  goods. 

The  remark  of  an  eminent  French  writer  vcfj 
much  confirms  what  I  have  said  at  page  298,  ott 
the  preference  which  should  always  be  given  •!• 
chemical  bleaching  when  properly  conducted; 
''Thread  bleached  by  the  oxygenated  muriatie 
acid,**  says  he,  ''  may  be  used  by  the  sempstress 
with  much  more  speed  and  briskness  than  thread 
of  the  same  quality  bleached  in  the  field ;  it  is  less 
brittle,  and  may  be  struck  much  more  effectually 
home  to  its  place  in  weaving,  and  does  not  move 
afterwards.  I  received,**  says  he,  "this  valuablt 
information  from  impartial  and  unprejudiced  manu- 
facturers".** 

Notwithstanding  the  bleacher  of  hose  may  easily 
determine  the  real  quantity  of  bleaching  liquid  to 
be  used,  yet  there  is  still  considerable  risk  in  the 


**  Pajot  dcs  Chnrmcs  on  Bleaching,  translated  by  Nichobon, 
page  138. 


ON  B&BACHING.  ^  S49 

proeiesn, '  and  a:danger  of  the-  texture  of  the  articles 
bdag  in  some. measure  iojured  if.  the  operation  be 
conducted  with  carelessness,  or  by  those  who.  are 
onacquainted  with  thie  .properties  of  the  bleadutig 
liquor.  Oti  this  account,  therefore,  it  is  desirable 
that  the  public  ,  should  be  acquainted  with  a  test 
^t  would  in  every  case  show,  whether  the  che« 
mieals  had  been  properly  applied  or  not ;  or,  in 
okher  words,  whether  the  goods  which  an  indivi<* 
dual  ihay  be  about  to  purchase,  have  or  have  not 
been  impaired  by  the  process  of  bleaching. 
*  The  makers  of  thread  and  cotton  hose  were  so 
convinced  of  the  importance  of  having  a  test  of 
this  kind,  that  some  few  years  ago  the  principal 
manufacturers  adopted  the  practice  of  running  a 
fine  of  vat-blue  thread  dyed  very  dark,  or  of  Tur* 
lDey«-red'%  along  the  top  of  each  stocking;  and 
tboae  bleachers  only  were  employed  by  them  who 
oouM  render  the  hose  beautifully  white,  without 
cflBunng  the  blue  or  red  stripes,  or  even  lessening 
their  intensity  of  colour. 

The  chloride  of  lime  will  destroy  indigo^blue  or 
Ihe  Turkey-red  dye,  if  it  be  used  of  a  considerable 
stvength  ;  and  yet  it  may  be  so  diluted,  that  it 
will  be  strong  enough  to  bleach  linen  or  cotton 
goods  effectually,  and  still  be  incapable  of  injuring 
the  colours  above  mentioned.  On  this  account  it 
appears  to  me  that  these  dyes  will  always  afford 

**  These  are  two  of  the  most  permanent  dyes ;  but  1  know 
of  no  colour  that  will  resist  a  very  strong  preparation  of 
dilorine. 


360  OH  B&RAcmKa^ 

esfcellent  tests  for  aMfertaining  when  the  bleadny 
process  has  been  properly  or  impropeify  eo» 
ducted. 

Great  advantages  might  indeed  aecme  to  the 
manufactures  of  this  country  if  the  makers  of  ^phdn 
calicoeSy  dimities^  hempen  cloths,  cambrics^  and 
Irish  Hnensy  as  well  as  the  makers  of  cotton  hbiei 
would  adopt  die  method  of  running  a  lineof  sndi 
&3loured  threads  along  one  of  the  edges  of  tfaeii 
goods,  before  they  send  them  to  be  Ueached;  and 
that  they  would  employ  no  bleacher  who  would  ml 
engage  to  presenre  Uiose  colours  entiie,  and  of  their 
original  perfection  or  intensity.  •   •  ' 

Were  this  to  become  a  general  practice,,  tbe  poib' 
lie  would  soon  learn  the  importance  of  pofcbi^ng 
no  goods  but  such  as  contain  that  baid^  of  sttenglh 
and  goodness,  and  the  nation  would  be  aore  of 
preserving  that  superiority  in  the  foreign  mntet 
to  which  it  has  been  accustomed,  but  whickfaas 
lately  been  so  much  endangered  by  the  uncertainty 
with  which  the  modern  practice  of  bleaching  has 
been  attended.  Until  something  of  this  kind  be 
established,  no  one  can  be  certain  of  the  quality  4if 
the  goods  he  purchases.  In  buying  linen  and  cot* 
ton  hose,  he  may  indeed  at  present  avail  himself 
of  the  precaution  I  have  been  recommending,  as 
there  are  now  white  hose  in  abundance  in  the  hmuv 
ket  which  contain  these  kinds  of  coloured  lines  in 
perfection,  and  which  show  that  the  goods  hav^  un^ 
dergone  the  necessary  ordeal,  and  have  come  forth 
from  it  uninjured.     The  design  of  this  detail  is  to 


ON  BLfiACHING.  351 

cortvlnce  tlie  public,  that  it  would  be  to  Uieir  nd- 
vaotuge  to  demand  that  the  same  attention  should 
be  paid  to  the  bleaching  of  every  other  kind  of 
goods,  whether  they  be  manufactured  of  linen  or 
cotton. 

It  is  a  common  practice  In  the  neighbourhood 
of  Manchester,  in  the  process  called  singeing,  as 
described  at  page  262  vol.  i,  of  these  Essays,  to  pass 
fustians  and  some  other  kinds  of  goods.  In  a  damp 
state,  over  a  red-hot  cast-Iron  roller ;  and  though 
every  part  of  the  piece  comes  in  actual  contact  with 
the  red-hot  cylinder,  the  business  is  conducted  so 
adroitly,  that  the  goods  sustain  no  injury  what- 
ever ;  whereas.  If  there  were  any  irregularity  in  the 
movement,  the  goods  must  be  burnt.  Just  so  it 
is  in  bleaching.  If  the  articles  be  suffered  to  lie 
too  long  in  the  bleaching  liquor,  or  if  that  be 
improperly  prepared,  mischief  will  be  done ;  but 
in  the  hands  of  proper  people  this  can  never 
happen. 

The  following  are  some  of  the  sources  from 
whence  further  information  may  be  obtained  on  the 
subject  of  this  Essay.  *'  A  Memoir  on  Hyperoxy- 
muriatic  Salts,"  by  Dollfus,  in  Annales  de  Chimie, 
tome  1.  page  225. — "  Additions  to  the  Description 
of  the  Bleaching  Process  in  France,"  by  M.  Ber- 
thollet,  tome  vi.  of  the  same  work,  page  204. — 
"  A  Letter  from  M.  D.  Hellancourt  to  M.  Lavoi- 
sier, giving  an  Account  of  the  Method  of  bleaching 
Cloth  in  Beauvoisis  in  Flanders,  and  in^X*ower  Pi- 
caady,"  tome  vii,  page  263 — 277. — "  Memoir  on 


852  ON  9L£ACHINO. 

the  Diatillatipti  of  Manganese  vj^ith  Sulphuric  Acid," 
by  Vauqudin  and  Bouvier,  tome.  yii.  page  287.rT* 
'<Tbe  Manner  pf  preparing,  fit  all .  tknes, .  and  j/a 
aU  places,  s  and  at  little  coat,  a  saponaceoys  Lj* 
quor  for  whitening  Cloth."  Pelletier,  tome  xix. 
page  349. 


ESSAY  XIII. 


ON 


WATER. 


VOL.  II. 


2a 


ESSAY  XIII. 


ov 


WATER. 


In  die  beginning  of  the  last  centuiy  it  ms  sup- 
poted,  that  there  were  four  elementary  bodies  in 
Btenre,  and  that  this  terrestrial  world  was  entirely 
connpoyd  of  those  elements.  Of  these  first  prin- 
dplost  WATER  was  one ;  and  ccHisequeilitly  this  was 
rinrays  considered  to  be  a  simple  substance  that 
0Dtered  into  the  composition  of  most  other  bodies^ 
but  was  itself  incapable  of  decomposition. 

Boerhaave  says,  that  it  was  in  consequence  of 
Moses  having  delivered  a  tradition  that  the  Spirit 
of  God,  brooding  upon  the  face  of  the  waters,  had 
oommunicated  to  them  a  prolific  virtue,  that  the 
MHnent  Persians  looked  upon  water  as  the  principle 
of  all  bodies  > . 

Many  other  ancient  nations  considered  water  to 
be  the  first  principle  of  all  created  things.  Milton 
likewise  favours  the  idea : 


«•■»■ 


■  See  Genesis  i.  ver.  2. 
2  A  2 


356  ON  WATER. 


"  On  the  watery  calm 


His  brooding  wings  the  spirit  of  God  outspread. 
And  vital  virtue  infus'd^  and  vital  warmth 
lliroughout  the  fluid  mans  *.** 

The  same  doctrine  is  als(o  taught  in  the  Koran. 
**  Do  not  tlie  unbelievers  know  that  the  heavens  and 
the  earth  were  solid,  and  I  clave  the  same  in  sunder, 
and  made  every  living  thing  of  water  3  .^'' 

Of  late  years,  however,  it  has  been  discovered^ 
that  this  notion  of  the  simplicity  of  water  is  er- 
roneous, and  that  the  four  substances  which  the 
ancients  had  fixed  upon  as  the  simple  elements  of 
Nature  are  themselves  all  compound  bodies. 

Water  is  composed  of  oxygen  and  hydrogen  Ui 
the  proportions  of  85  parts  by  weight  of  tlie  for? 
mer  to  1 5  of  the  latter;  so  that  85  ounces  of  oiqrgeii 
gas  when  united  with  15  ounces  of  hydix^jeo  fi9 
will  form  100  ounces  of  water.  These  are  wbal 
are  deemed  the  usual  proportions :  but  they  cannot 
be  considered  as  absolutely  and  undeniably  corree^ 
because  the  quantity  of  aqueous  vapour  which  the 
gases  usually  contain  renders  it  difficult,  if  not  al- 
together impossible,  to  produce  an  accurate  e^tir 
mate  ^.  Some  experiments  by  Ritter  seem  to  pn>TB 
that^i>2;€^  water  contains  a  less  proportion  of  oxy- 
gen. These  were  communicated  by  Proft^aor 
Jameson  to  Mr.  J.  Murray,  who  has  given  an  in- 
teresting account  of  them  in  the  2nd  volume  of  his 


*  Paradise  Lost,  book  vii.  line  234. 
'  See  Sale's  Koran,  vol.  ii.  page  155. 
^  See  a  Memoir  by  Humboldt  and  Gay-Lussac  on  this  sub- 
ject in  vol.  liii.  of  the  JnnaUs  de  Chimie,  pp.  239 — 259. 


ON  WATER.  357 

Sjrstem  of  Chemistry.  The  most  beautiful,  and 
apparently  the  most  decisive  of  these  experiments, 
is  that  of  diffusing  in  various  portions  of  water  a 
quantity  of  newly  prepared  white  prussiate  of  iron, 
(a  substance  which,  by  the  blue  colour  it  assumes 
when  it  receives  oxygen,  is  a  very  delicate  test  of 
that  principle,)  and  excluding  the  action  of  atmo- 
spheric air  by  a  thin  layer  of  oil  on  the  surface  of  the 
liquid.  These  vessels  were  exposed  to  various  de* 
grees  of  cold,  and  as  soon  as  the  water  in  either  of 
them  froze,  the  white  precipitate  became  bltie. 

Since  the  compound  nature  of  water  has  been 
understood,  many  ways  have  been  discovered  of 
decomposing  and  re-forming  it  from  its  original 
elements  ^  so  that  there  is  now  no  longer  the  least 
dofibt  either  of  its  composition,  or  of  the  propor- 
tion of  each  of  the  elements  of  which  it  consists. 

Water  may  be  decomposed  by  the  agency  of 
some  combustible  substances;  also  by  means  of 
common  and  Voltaic  electricity.  Vegetables  of  all 
kinds,  while  alive  and  fresh,  are  likewise  furnished 
with  organs  for  the  decomposition  of  water,  by 
whicb  they  appropriate  its  hydrogen  and  part  of  the 
oxygen  to  the  formation  of  oil,  sugar,  starch,  and 
numberless  others  of  the  combinations  to  which 
we  apply  the  term  vegetable  principles. 

Fish,  especially  those  of  the  cetaceous  tribe,  con- 
stantly decompose  water  and  live  upon  its  hydrogen. 

*  A  description  of  Mr.  Cuthbertson*8  apparatus  for  producing 
water  by  the  combustion  of  hydrogen  in  oxygen  gas,  will  be 
found  in  the  Philosophical  Magazine,  vol.  ti.  page  317. 


358  ON  WATER. 

We  have  also  reason  to  believe  that  some  tcrresti ial 
animals  are  endowed  with  the  sannie  fecultjr.  Ccrant 
Ramfurd  has  very  satisfoctoriiy  shown^  that  die 
surprisingly  small  qaanti^  of  solid  food  wfaidi  u 
sufficient  for  nourishment  when  converted  into  rich 
and  palatable  soup,  is  owing  to  the  cuUnaiy  piOM 
cess  having  prepared  the  water  for  decomporitioii^ 
and  that  this  is  ultiiHately  effected  during  die  id 
of  digestion  ^.  I  suspect  that  tainted  wooden  vi^ 
^Is  have  the  property  of  decomposing  water.  It 
is  related  in  the  Philosophical  Transactions,  that  a 
Company  of  English  who  had  provided  themadtes 
with  good  wholesome  water  at  8t.  Jago,  whiek  was 
put  into  hogsheads,  found  on  their  arrival  at  the 
Istatld  of  Borneo,  that  the  water  was  beoonw  ««> 
ceedidgly  fetid,  and  that  it  emitted  a  vapour  wUdi 
caught  fire  dn  a  lighted  candle  being  brought  near 
It.  An  account  of  a  similar  change  in  some  water 
taken  from  the  Thames,  may  be  seen  in  the  same 
work  7.  It  is  a  curious  fetct,  that  if  an  electric 
spark  be  passed  through  oxygen  and  hydrogen 
gases,  whatever  may  be  the  proportions  of  the 
mixture,  85  parts  by  weight  of  oxygen  and  15  of 
hydrogen  will  be  the  only  proportions  that  unite  to 
form  wliter,  and  that  the  remainder  will  still  con- 
tinue in  the  state  of  gases. 

Thete  can  be  no  doubt  that  water  is  also  decotn- 
posed  in  many  of  our  chemical  processes,  and 

that  the  effects  which  are  produced  in  some  of  our 

.  I.  •■         ■  .  ■■      '  .,■■.■,),. 

^  Ramford'ft  Esstofs,  toI.  i.  ptLge  1 94-^02. 

7  Phili6sophkal  Tnrumc^mu,  No.  2G8>  p8ge  838, 


ON  WATER.  359 

maQabcturing  operations  are  owing  entirely  to  tlie 
same  cause.     I  will  adduce  one  instance. 

Considerable  advantage  is  derived  by  tbe  wooUen- 
dyera  from  the  use  of  water  in  the  preparation  of 
rasped  logwood.  As  the  wood  is  cut  into  chips, 
they  sprinkle  It  abundantly  with  water,  and  in  tliat 
moiatened  state  it  is  thrown  into  large  heaps,  and 
sometimes  into  bins  of  great  size,  where  it  is  suf- 
fered to  lie  as  long  as  is  convenient.  By  this  treat* 
ment  the  chips  become  heated,  or  they  ferment 
a&  the  dyers  call  it,  and  thus  undergo  a  very  re- 
markable change;  for,  after  having  lain  a  few 
months  in  this  state,  they  give  out  the  colouring 
matter  in  the  dyeing  copper  much  more  easily ; 
and  any  given  quantity  of  such  chips  will  produce  a 
more  intensedye  than  could  have  been  obtained  from 
an  equal  quantity  of  chips  which  had  not  been  thus 
treated.  It  is  difficult  to  account  for  this,  unless 
we  suppose  that  the  water  becomes  in  part  decom- 
posed, and  that  its  oxygen,  uniting  with  the  vege- 
table colouring  matter,  renders  it  more  intense, — 
similar  to  the  c[ise  of  fruits,  which  deepen  in  co- 
lonr  as  they  ripen,  by  their  gradual  absorption  of 
oxygen  *•. 

From  the  observations  which  I  have  made  during 
the  superintendance  of  a  variety  of  chemical  pro- 
cesses, I  think  I  am  justified  in  asserting  that, 
whenever  this  subject  comes  to  be  thoroughly  in- 
vestigated, it  will  be  found  that  water  has  more  to 

'  See  "  A  Memoir  on  the  Colouring  of  Vegetable  SubBt»nc« 
by  Oxygen,"  in  Annali;i  de  Cluiaie,  tome  t.  page  80— 91.   ... 


i 


300  OK.  WATER. 

do  in  influencing  the  results  of  most  of  the  opef» 
tions  of  nature  and  art  than  has  generally  been  ima^ 
gined.  This  will  perhaps  appear  probaUe, .  wfaea 
it  is  considered  that  water  is  a  solvent  for  the  alka- 
lies as  well  as  for  almost  all  saline  bodies,  mUB, 
and  earths ;  .and  that  by  its  decomposition  it  ofben 
imparts  oxygen  to  one  principle  and  hydrogen  ta 
another  9, 

It  is  from  this  idea  that  I  am  induced  to  fix  upon 
water  as  one  of  the  subjects  of  these  Essays,  with 
a  view  of  directing  the  attention  of  our  various 
artists  and  manufacturers  to  this  one  particubc 
point.  .       .;i 

.The  subject  is  so  important,  and  embraces  sodi 
a  variety  of  matter*  that  it  would  be  impossible  in 
the  course  of  a  short  essay  to  enter  into  that  amplM 
fication  of  detail  which  the  matter  deserves.  •  A 
history  of  the  different  opinions  respecting  water, 
and  of  the  progress  of  the  various  discoveries  H>  in 
this  branch  of  natural  philosophy,  will  therefeie 
not  be  expected ;  but  if  such  evidence  can  be  ad* 
duced  as  will  be  sufficient  to  convince  the  inquiring 
reader  that  the  most  common  fluid  we  have,  vid 
that  which  is  the  least  thought  of,  is  capable  of 
effecting  the  most  important  changes  in  the  ma* 

*  This  flnid  must  also  possess  the  power  of  dissolviBg  catim  y 
for  by  what  other  means  can  this  be  conveyed  into  Sie  vege- 
table organs  so  as  to  form  the  tigneous  fibre  > 

*^  The  discovery  of  the  decomposition  of  water  has  enlaiged 
the  sphere  of  chemical  knowledge  very  surprisingly,  particukrly 
with  regard  to  several  phienomena  respecting  t^  roetab,  wbkn 
otherwise  must  have  remaiQed  totally  inexplicable. 


ON   WATER.  351 

lerkla  on  which  he  operates",  or  of  producing 
molts  which  will  at  times  disappoint  all  his  ex« 
pectations ;  something  will  be  done  towards  in- 
forming the  public  mind»  or,  at  least,  the  young 
flunufiieturer  will  be  furnished  with  an  idea  that 
nay  be  of  use  to  him  in  the  conduct  of  some  of 
those  processes  which  it  will  be  his  business  to 
superintend. 

'  Water  exists  in  four  separate  and  distinct  forms, 
?i&  in  the  state  of  ice;  in  that  of  a  fluid;  in  the 
state  of  vapour ;  and  in  a  state  of  chemical  combi- 
nation with  other  bodies. 

.The  most  simple  form  in  which  it  is  probable 
that  water  will  ever  be  exhibited,  is  that  of  ice  ^ 
for  by  the  mere  combination  of  ice  with  caloric 
fiiid  water  will  be  formed,  and  a  further  portion 
of  caloric  will  convert  this  fluid  into  steam,  the 
most  attenuated  aqueous  vapour  being  nothing 
meve  than  ice  dissolved  and  rarefied  by  the  solvent 
and  expansive  power  of  caloric. 

Besides  these  difierent  appearances  of  water,* 
iriiich  are  familiar  to  every  one,  water  is  known  to 
csdst  in  chemical  combination  with  other  bodies, 
forming  an  essential  part  of  their  substance,  and 
contributing  towards  the  semblance,  forms  and  qua* 
Ktiea  which  they  respectively  exhibit ;  but  in  these 
eases  it  undergoes  so  considerable  a  degree  of  con« 
dcnsation,  that  it  loses  all  the  common  characters 


"  Scheele  dissolved  even  glass  by  boijing  r  small  quantity  of 
dialilled  water  for  several  days  in  a  matrass  made  of  that  mate* 
rial.    See  the  Preface  to  his  Trvatise  on  Air  and  Fire. 


362  OK  WATER. 

of  water.  The  water,  in  diese  instances^  unitea  10 
certain  definite  proportions,  and  such  compoundt 
ace  known  to  the  modern  chemist  by  the  name  of 
hydrates. 

Some  students  at  Florence  having  provided  a 
hollow  globe  of  gold,  filled  it  with  water  and  dioi 
submitted  it  to  the  action  of  Jt  very  powerful  press? 
but  they  were  not  able  to  produce  any  condensalioii 
of  the  fluid  whatever,  though  the  press  was  soffi- 
ciently  powerful  to  ooeasion  the  water  to  exude 
dirough  the  pores  of  the  metallic  vessel  in  whieb  it 
was  inclosed  '*.  Notwithstanding  this,  the  desev^ 
tion  of  an  instrument  invented  by  Mons.  Abich 
fear'  the  compression  of  water  will  be  found  in  ^ 
Mohtldy  Review,  vol.  facviii.  p.  1/6. 

'  Zimmisnnan  states  that  water  may  be  compietared 
so  as  to  produce  a  diminution  of  ita  bnlk  neai]^ 
equal  to  l-24th  part,  giving  it  a  specific  gcavi^ 
even  greater  than  that  of  sea  water  ". 

Canton  long  ago  proved  the  expansibility  of  watan 
but  Mr.  Jacob  Perkins  has  latdy  contrived  an  iiH 
atrument  which  he  calls  a  Pieaometer,  in  wfaidi.he 
has  subjoHed  water  to  a  pressureof  326  atmoq>hera^ 
and  has  succeeded  in  increasing  its  density  3.5  pec 
cent.  ^*  Nature  however,  as  has  already  been  hinted 
effects  the  condensation  of  water  in  many  of 'her 
operations,  and  it  will  be  sufficient  to  estaUisb 

■  ■■■■II  I  I       II    ii.i         !■      ■     I  I       ■     ■■■■       I  I  ■!    , 

1*  EMsa^t  of  N€tlMT(A  Bspenmm^  made  in  ikt  4oadSme  dd 

Gmento,  Waller*s  Translation^  4to,  London  1684,  page  20S. 

*^  Treatue  of  the  EUuticUy  0/  Water,   Amsterdam. 
'^  Quar^er^  J(mrna/^Sci£itce,Yol.  z.  p«399. 


ON   WATBR.  S63 

the  troth  of  the  assertion  just  to  mention  a  few  ex*" 
amples* 

It  is  an  axiom  in  chemical  science,  that  bodies 
in  acquiring  condensation  give  out  caloric  '^.  Thus 
WBltif  always  parts  with  caloric  in  the  act  of  freez- 
ing; though  it  takes  such  a  form  during  its  crystal- 
lisation as  disguises  the  actual  condensation  of  its 
parts,  and  occasions  a  diminution  of  its  specific  gra- 
yiCy.  But  water  thrown  upon  quick  lime  gives  out 
moie  heat  than  it  does  in  the  act  of  freezing :  con- 
sequently it  becomes  more  condensed  when  com- 
bined with  the  lime,  than  when  it  exists  in  the  state 
of  ioe. 

If  a  hot  saturated  solution  of  sulphate  of  soda  be 
Ctorked  up  in  a  glass  bottle  contdning  a  thermome- 
lek*,  and  then  laid  aside  to  acquire  the  temperature 
<»{  the  atmosphere,  the  solution  will  cool  without 
the  salt  crystallizing.  When  the  whole  has  become 
sufficiently  cold,  and  the  degree  noted  at  which  the 
mercury  stands  in  the  thermometer,  if  the  cork  be 
then  removed  to  admit  the  atmospheric  air,  the  salt 
frill  instantly  shoot  into  crystals,  and  the  mercury 
will  rise  in  the  thermometer  several  degrees.  What 
0aa  this  rise  of  the  thermometer  be  owing  to,  if 
it  be  not  to  the  water  parting  with  its  caloric  as  it 
miites  with  the  sulphuric  salt  and  becomes  con- 
densed in  the  newly  formed  crystals  ? 

This  salt,  which  will  preserve  its  figure  and  so^ 
~  -  •■  — -  -     -  -  -   - 

*^  The  constant  rise  of  tenapersture  in  the  atmosphere  after 
rain,  is  owing  to  the  aqueous  vapour  gifing  out  caloric  while  it 
is  dMuiging  into  water. 


364  ON   WATER. 

lidity  so  long  as  it  retains  this  water  in  its  oompo- 
sition,  will  become  smooth  and  pulverulent,  when 
it  loses  the  water  of  crystallization,  by  exposure  to 
the  action  of  the  atmosphere.  Those  who  are  con- 
versant with  salts  well  know,  that  some  lose  the 
water  of  crystallization  and  eflioresce,  while  others 
absorb  water  and  deliquesce,  by  exposure  to  the  at- 
mosphere. Sulphate  of  soda,  borate  of  soda,  sul- 
phite of  lime,  and  phosphite  of  soda,  belong  to  the 
first;  and  muriate  of  lime,  muriate  of  magnesia, 
and  nitrate  of  lime,  belong  to  the  latter  of  these 
classes. 

Sometimes  one  salt  will  rob  another  of  its  water 
of  crystallization.  Thus,  crystallized  muriate  of  lime 
will  take  the  water  from  the  crystals  of  carbonate  of 
soda.  If  both  salts  be  inclosed  in  the  same  vessel, 
and  yet  not  in  contact,  the  carbonate  of  soda  mil 
fall  into  powder  and  the  muriate  of  lime  will  be-> 
come  fluid.  Should  nitric  acid  ever  be  required  of 
greater  specific  gravity  than  it  can  be  procured  by 
the  usual  methods,  I  suspect  it  might  be  concen- 
trated by  inclosing  it  in  an  air-tight  vessel  with  a 
portion  of  the  heaviest  sulphuric  acid ;  for  this, 
having  so  determinate  an  afiinity  for  water,  would 
probably  abstract  more  of  it  from  the  nitric  acid 
than  could  be  taken  away  by  any  other  means. 

Not  only  the  artificial  but  also  the  natural  salts, 
whether  they  be  earthy,  alkaline  or  metallic,  are 
chiefly  indebted  to  their  respective  portions  of  water 
for  their  transparency,  for  their  crystalline  appear- 
ance, and  even  in  part  for  their  solidity. 

Few  of  the  saline  productions  of  nature  are  bet- 


ON    WAT£R.  365 

ter  known  than  sulphate  of  liine,  or  common  plaster 
of  Puisy  which  when  taken  out  of  the  earth  is  a 
attbstance  very  hard  and  compact.  For  the  use  of 
maaonsy  statuaries,  and  some  other  artists,  this 
earthy  salt  is  broken  into  small  pieces,  and  then 
aubmitted  to  the  heat  of  a  common  oven  to  dissi- 
|Nite  so  much  of  the  water  of  its  composition  as  can 
be  separated  by  this  means.  After  this  operation. 
the  aulpliate  of  lime  may  be  easily  reduced  to  the 
alate  of  a  soft  impalpable  powder. 

.When  the  plaster,  which  h^  beefi  thus  prepared, 
is  to  be  used,  the  workman,  in  order  to  give  it  its 
<mginal  solidity,  mixes  it  with  a  certain  portion  of 
water,  and  then  pours  it  hastily  into  moulds,  to  form 
statues,  busts,  cornices,  or  other  ornamental  work 
for  which  it  in  generally  employed.  In  this  instance 
tbe  dried  plaster  has  such  an  affinity  for  water  and 
a  capacity  to  regain  what  it  had  lost,  that  it  instantly 
attracts  and  condenses  a  very  considerable  quantity, 
and  the  whole  becomes  changed  into  one  entire  and 
very  compact  mass  ^^. 

Pure  alumina  has  a  similar  affinity  for  water,  and 
the  union  is  so  intimate  that  it  is  almost  impossible 
ever  to  separate  the  water  with  which  it  has  been 
united.  Saussure,  who  made  experiments  on  this 
subject,  declares  that  this  earth  has  so  powerful  an 
attraction  for  water,  that  it  will  retain  a  tenth  of  its 
weight  of  that  fluid,  even  though  it  be  submitted 
to  a  heat  that  will  fuse  iron. 


'*  See  Essay  on  Earthenware^  vol.  ii.  p.  1 18, 


i366  ON   WATER). 

•  Potash  after  having  been  sttboutted  to  a  red  heat 
IS  found  to  ffetain  more  than  IS'  per  ceiit.»  and  aoda 
fiearly  10  per  cent.,  of  water  ^.  Accorduig  te-the 
tinalysis  of  D*Areet,  the  proportion  of  water  is  wea 
greater  tftian  this '^ 

Seeing  then  that  water  has  so  great  an  afl&ni^ 
for  many  bo^es^  and  that  it  imparts  transpartnG|r 
to  one  and  hardness  to  another^  it  is  surely  wmth 
while  to  examine  whether  it  may  not  fulfill  an  ioh 
portant  office  in  some  medianioal  and  mannfittstlip 
fing  processes  in  which  its  operation  has  been  least 
snspeoted. 

If  a  perfectly  compact  x^nidble  be  well  filled  walk 
dry  chalk,  and  then  submitted  to  the  strongest  ^hcst 
4hat  is  usually  raised  in  a  common  fire*plaic^  itmill 
be  extremely  difficult,  |f  not  impossible,  tb€QSii«l 
4be  ii^le  of  the  -chalk  into  lime.  But  if  a  hale 
be  perforated  in  the  bottom  of  the  crucible,  and  dds 
£xed  in  a  situation  where  a  current  of  aqueous  va- 
pour, or  atmospheric  air,  can  freely  pass  through  it, 
the  carbonic  acid  will  be  separated,  and  the  fime 
completely  formed,  in  less  time  and  with  less  heat 
than  it  could  have  been  effected  at  without  such  an 
accession.  The  water  aids  the  separation  of  the 
carbonic  acid,  and  enables  it  to  pass  off  in  the  form 
of  gas.  This  fact  was  first  communicated  to  me  hf 
Mr.  Dalton  of  Manchester ;  and  my  own  observa- 
tions have  since  confirn^d  the  truth  of  his  statement 


■'  Berard  in  Annates  de  Chimie,  tome  Ixxii.  p.  96. 
'*  Annates  de  Cfrntie,  tome  Ixviii.  p.  175 — 190. 


ON    WATER.  3fi7 

1  -Qw  common  lime  kilns  are  all  built  with  an 
opening  at  tlie  bottom,  for  the  removal  of  the  litne 
when  burnt.  This  allows  of  a  constant  current  of 
atmospheric  air  through  the  whole  mass  of  stone, 
and  consuquently  a  considerable  portion  of  water 
b  convej'ed  to  it  during  the  whole  progress  of  the 
operation.  I  would  therefore  suggest  to  the  burn- 
ers of  lime,  that  it  may  be  worth  while,  whenever 
they  draw  the  contents  of  a  kiln  not  sufficiently 
burnt,  (which  often  happens,)  to  notice  whether  the 
atmosphere  had  not  been  in  an  unusually  dry  state 
at  that  period,  and  whetiier  the  imperfection  of  the 
Ume  should  not  have  been  ascribed  rather  to  this 
than  any  other  cause. 

Should  this  be  found  to  be  the  case,  the  incon- 
venience might  be  obviated  by  placing  a  broad  ves- 
sel of  water  at  tlie  mouth  of  each  kiln ;  because  the 
heat  of  the  Idtn  would  occasion  a  constant  evapora- 
tion from  its  surface,  and  the  current  of  air  which 
>ets  through  tlie  kiln  would  convey  the  aqueous  va- 
pour to  every  part. 

In  like  manner,  there  is  reason  to  believe  that 
quick  lime  would  not  combine  with  carbonic  acid, 
however  long  it  might  be  exposed  to  its  action,  pro- 
vided water  were  not  present ;  and  that  the  mortar 
or  cement  employed  in  buildings  would  never  ac- 
quire the  hardness  of  which  it  is  capable,  were  it 
rot  for  the  gradual  absorption  of  the  water  of  the 
atmospliere. 

I  have  been  told  that  the  Earl  of  Stanhope  has 
formed  an  establishment  fur  burning  lime  on  some 


368  ON   WAT£R.' 

new  principle,  and  that  he  furnisbet  it  in  a  stale'  of  * 
greater  purity  than  it  can  be  had  elaewhere.     .  .  ^ 

Vegetable  fermentation  cannot  take  place  witln 
out  water;  and  I  suspect  that  the  excellence  of  wine 
and  all  other  fermented  liquors  depends  in  a  gMat 
measure  on  the  proportion  which  the  water  bean  to 
that  of  the  sugar  and  the  mucilage,  llie  perfectioni 
of  the  process  of  malting,  as  is  well  known  to  all  good 
maltsters,  depends  in  a  great  measure  on  the  condi, 
being  properly  sprinkled  with  water.  In  forming 
solutions  of  the  metals  in  the  muriadc  and  some 
other  acids,  the  water  becomes  decomposed  in  pro^. 
portion  as  its  oxygen  is  required  to  oxidixe  tlie  men 
tal,  and  its  hydrogen  escapes  through  the  fluid  in 
the  form  of  gas.  This  in  some  degree  acoounti 
for  the  great  loss  of  weight  which  is  always  expe- 
rienced in  making  the  solutions  of.  tin. and  otbct  • 
metals. 

Here  it  may  perhaps  not  be  amiss  to  advert  to  a  . 
circumstance  which  may  involve  the  safety  of  some 
individuals.     What  I  allude  to  is  this ;  that  those 
persons  who  are  in  the  habit  of  preparing  large 
quantities  of  muriate  of  tin,  are  perpetually  liable 
to  misfortunes  by  an  explosion  of  tlie  hydrogen  gai 
which  escapes  during  the  process.     Very  lately^.a  .• 
friend  of  mine  in  the  country  was  much  cut  in  the  . 
face  and  otherwise  injured  by  the  fragments,  of  an 
apparatus  in  which  this  operation  was  going  ont 
and  uhich  burst  with  a  tremendous  report,  in  con* 
sequence  of  a  lighted  candle  having  been  incau- 
tiously brought  too  near  it. 


ON    WATER.  3CU 

Though  water  is  decomposed  and  a  loss  of  weight 
is  sustained  in  many  chemical  operations,  ivater,  on 
the  contrary,  is  often  produced  in  certain  cases  of 
combustion,  where  the  presence  of  this  fluid  is  least 
suspected;  and  this  may  influence  the  results  of 
many  operations  in  a  way  that  is  quite  inexplicable 
to  those  who  are  unacquainted  with  the  principles 
of  chemistry.  Spirits  of  wine,  oils,  wax,  tallow,  and 
many  other  substances,  always  produce  water  du- 
ring their  combustion.  If  a  cold  glass  vessel  he 
inverted  over  the  flame  of  burning  alcohol,  water 
may  be  collected  that  is  perfectly  free  from  taste  or 
smell,  and  in  every  respect  like  distilled  water.  One 
pound  of  alcohol  will  produce  eighteen  ounces  of 
water  ". 

The  PURITY  of  the  water  that  is  employed  in 
some  of  our  manufactures  is  an  object  of  the  most 
material  consequence.  A  few  instances  may  easily 
be  adduced  to  substantiate  the  truth  of  this  asser- 
tion. 

In  the  processes  of  bleaching,  dyeing,  and  calico- 
printing;  in  those  of  refining  sugar,  of  brewing  malt 
liquors ;  in  the  manufacture  of  paper,  and  in  many 
others  which  might  be  enumerated  ;  the  quality  of 
the  article  is  much  influenced  by  the  nature  of  the 
water  which  has  been  employed  in  its  production. 

More  than  two  thousand  years  ago  Hippocratis 
wrote  expressly  on  the  difference  observable  in 
waters.     Celsus  gave  directions  for  examining  the 


"  This  subject  is  further  elucidated  ii 
The  Chemiral  Calechitm, 


the  12th  diopter  of 


370  OK  :WM*BHi 

tpf^fic  gnntjr  of  water  %  and  Pliny  attemptel  to 
direct  hift  icadars  hovfr  to  distinguish  the  aalubriow 
from  that  whidi  is  imwholeepme.  Bat,  till  the  titdt 
of. Boyle  or  tbmihls  the  end  of  the  aefenteenth  eM* 
terj^  no  means  had  been  derised  of  analysing  wattiv 
ov  of  pronduncii^g  with  certainty  on  its  nature  and 
properties. 
.  There  is  a  letter  still  extant  firom  Synesids^  st 
Christian  bishop  of  the  fifth  century,  to  the  female 
philosopher  Hjrpida,  under,  whom  be  had  formeriy 
studied,  in  which  he  comjdains  of  b^g  iU ;  says 
that  he  wishes  to  use  a  hydrosct^phot^  and  reqacsts 
that  she  would  cause  one  to  be  constructed  for  him. 
^*  It  is  a  cylindricad  tube,**  he  adds,  "  of  the  lAm  ef 
a  reed  or  pipe.  A  line  is  drawn  upon  it  lengthidss^ 
which  is  intersected  by  others,  and  these  pointi  tat 
the  weight  of  water.**  It  b  probable  that  the  bishop 
was  in  an  infirm  state,  that  his  physicians  had  4V- 
dered  him  to  drink  none  but  pure  water,  and  that 
the  instrument  he  wanted  was  one  similar  to  our 
hydrometer  for  the  purpose  of  examining  the  we^bt 
of  diflbriBRtT#aters»  in  orderto  ascertain  which  would 
be«be8t 'fbr  his  uae/r    ;wj 

: )  Those  which  are  geDomlly  known  by  the  appellap 
tidn  of  hatd^  water^  hold  certain  salu  in  sohil300» 
and  are  unfit  for  pivate  use  as  well  as  for  manube- 
turing  processes.  Frequently,  however,  according 
to  the  remark  of  Be^man,  the  sum  of  all  the  saUne 
aubstahces  dissolfed  in  a  mineral  water  does  not 


*»  Celsus  De  Medicina,  lib  ii.  cap.  18. 


ON    WATER  371 

ceed  a  six-lliou&atidlh  part  of  its  weight,  and  yet  may 
be  composed  of  six  or  eight  difterent  substances. 
Mr.  Dalton  asserts,  from  the  result  of  his  own  ex- 
periments, that  tlie  hardest  spring  water  seldom  con- 
tains so  much  as  one-thousandth  part  of  its  weight 
of  any  foreign  body  m  solution  ". 

Nature,  who  in  her  inexhaustible  bounty  gives  us 
distilled  water  from  heaven,  has  so  ordained  it,  that 
there  are  few  districts  of  much  extent  where  spring 
wattff  may  not  also  be  found,  whicli  is  sufficiently 
pure  for  most  purposes  either  of  manufacture  or 
domestic  economy  *'. 

It  may  here  be  remnrked,  that  in  sinking  wells  it 
is  important  to  line  them  with  free-stone,  and  not 
with  bricks  as  is  usual,  because  most  of  the  bricks 
which  ore  made  in  this  country  have  the  property 
of  hardening  the  water;  whereas  the  stone  has  not 
this  effect. 

Nearly  seventy  years  ago  Dr.  Home  explained 
why  hard  water  is  injurious  to  dyers  and  bleachers. 
It  ifl  related  by  him  that  Mr.  Samuel  Hart,  who 
waa  a  ct;lebrated  bleacher  in  the  middle  of  tbe 
last  century,  was  about  to  establish  a  new  bleach- 
field  in  a  particular  place,  which  seemed  favourable 
for  his  purpose  on  account  of  the  appearance  of  tbe 


'  W  rfew  Si/ilem  oj  Chemical  Philosophy,  p.  27r, 
'  <*  1>iiB  Msertion  ik  somewhat  canlradicted  by  Ur.  Plot  in 
hill  Hutory  of  Stafiortkhire,  who  relates  n  case  of  a  well  wliicli 
wax  aunic  in  that  county  to  ihc  depth  of  S.COO  Teet,  without 
meeting  with  water :  but  this  was  ii  nire  instance.  See  Joum. 
'x^MB.  1060,  p.  14. 
»,W^^-  Q    „  9  >■■■■     I-'     M    ■■■  .1 


372  ON    WATftR. 

water  aiid  the  abundance  of  the  supply;  but  vvbeo 
he  eame  to  examine  it  by  some  of  the  best  ehiairi- 
tial  means  then  known,  it  wm  found saitnpnre,  that 
he  deemed  it  expedient  to  form  his  imeiided  eafa^ 
blishment  on  another  spot*^.  Most  of  our  spring 
water  contains  common  salt,  mth  catboiiattt^aad 
muriate  of  lime;  but  it  is  the  sulphate  of  lime  vhidi 
constitutes  what  we  call  hard  water.  -       .-  I".2i  .^ 

In  coal  districts,  where  the  coal  oecoirs*  near  the 
surface  of  the  ground,  the  brboks  and  rivers  in^^tbe 
neighbourhood  are  often  contaminated:  by  ihe 
suit  of  the  decomposition  of  the  sulphuretof  i 
called  martial  pyrites,  which  is  washed  into -tbem 
by  the  rains.  I  know  of  one  instance  in  Yoff)Bhu^ 
^ere  ah  establishment  for  scouring  and.  dycii% 
'woollen  yarn  miist  have  been  entirely  brokw  bp 
frdm  this  cause  aloOe,  if  the  proprietors  hailr^Mt 
found  the  means  of  leading  a  current  of  water  frbm 
^n  adjacent  spring  for  the  supply  of  the  maniifiw- 
tory.  ..  :      .  .  -7/ 

They  had  been  in  the  habit  of  using  the  water 
ironi  the  river  Calder,  which  has  constantly  a  por> 
tion  of  the  coal-pit  water  running  into  it ;  and  in 
the  summer  months,  or  in  very  dry  seasons  whan 
there  is  less  good  water  to  dilute  the  coal-pit  streaos, 
the  Calder  water,  for  most  of  the  purposes  for  whi^ 
a  dyer  requires  it,  is  rendered  nearly  useless.  This 
had  long  been  a  cause  of  vexation  and  inconveni- 
ence to  these  individuals,  when  the  bursting  of  ^one 

.— — : : .    1     - 

^  Experiments  on  Bleaching,  by  Dr.  Home,  8vo,  Ekliidmigb 

1756,  p.  281—288.  .  *       ' 


ON    WATER.  373 

of  theworn-outcoal-piu  so  inundated  the  bed  of  the 
Calder  with  the  solution  of  sulphate  of  iron,  that  its 
water  became  totally  un6t  for  their  purpose;  and 
this  induced  them  to  resolve  upon  incurring  the  ex- 
pense of  supplying  themselves  from  another  source. 
The  establishment  of  which  1  have  been  speaking 
is  not  a  large  one,  and  yet  the  proprietors  have  re- 
peatedly assured  me  that  the  consumption  of  soap 
in  scouring  their  woollen  yarn  is,  in  consequence  of 
the  softness  of  the  present  water,  so  much  dimi- 
nished OS  to  occasion  a  saving  to  them  of  more  than 
(ifty  pounds  per  annum.  I  am  also  acquainted  with 
some  gentlemen  in  the  north  of  Scotland  who  are 
proprietors  of  a  very  extensive  establishment  for 
bleaching  and  printing  calicoes,  and  who  for  many 
years  had  been  in  the  habit  of  bleaching  with  the 
water  from  the  river  Don,  but  liad  long  been  dis- 
satisfied with  the  uncertainty  that  attended  all  their 
processes,  and  which  they  could  ascribe  to  nothing 
but  the  impurity  of  the  water. 

These  gentlemen  possessing  much  chemical 
knowledge,  at  length  came  to  the  determination  of 
analysing  the  waters  of  all  tlie  neighbouring  springs, 
and  then  to  bleach  a  parcel  of  goods  with  llie  ut* 
most  care  in  that  which  appeared  to  possess  the 
greatest  purity.  The  result  answered  their  most 
sanguine  expectations.  Less  alkali  was  required 
in  the  process,  and  the  difference  in  the  appearance 
of  the  finished  goods  was  very  considerable  and  ob- 
vious. 

When  the  superiority  of  this  spring  of  water  was 


I 

L 


374  ON  wateH. 

thus  ascertained,  the  individtals  above  referred  to 
were  at  the  expense  of  conducting  it  in  pipes  far 
three  miles  through  their  own  estate,  taking  eai^ 
to  divert  the  waters  of  those  springs  which  contained 
iron  into  another  channel :  the  good  water  was  made 
to  empty  itself  into  one  vast  cistern,  capable  of  cml- 
taining  many  thousand  gallons,  made  with  ilMn  4i 
Scotch  granite  put  together  with  Roman  cement, 
and  securely  ptiddled  on  the  outside  with  day.  In 
this  reservoir  there  are  some  contrivances  for  the 
receiving  of  the  ti^ater  and  for  its  delivery  to  Ae 
works,  which  I  intend  to  describe  in  another  piit 
of  this  Eissay.  The  construction  of  this  reservoir, 
and  the  expense  of  bringing  the  water  from  so  gicit 
a  distance,  amounted  to  more  than  two  thbinasd 
pounds ;  but  the  adtanti^es  accruing  to  the  tnana* 
factory  from  the  possession  of  this  excellent  water 
have  been  so  great  and  important,  that  some  of  the 
proprietors  have  informed  me  that  they  have  no 
cause  to  regret  the  amount  of  the  expenditure* 
independently  of  an  elueidation  of  our  present  siib* 
ject,  I  consider  this  to  be  a  striking  insiance, 
among  many  others  whieh  are  daily  occurring^  of 
the  benefit  derived  to  the  arts  from  the  <^ultivaUon 
of  chemical  science. 

I  may  here  remark,  that  in  the  conveyance  of 
water  from  a  considerable  distance  it  is  of  great  im- 
portance to  ascertain  how  much  of  that  fluid  a  pipe 
of  a  given  bore  will  deliver  in  a  certain  time  ;  be* 
cause  iron  pipes  are  apt  to  oxidize  on  the  inside 
and  contaminate  the  water,  unless  they  be  kept 


ON  WATKR.  370 

nearly  full ;  whtireas,  when  they  are  not  large 
enough  to  take  olT  the  quantity  which  is  liiUDHH 
into  them,  they  are  Huble  to  burst". 

To  those  persons  who  have  no  idea  that  dif- 
ference of  water  can  produce  such  important  effeiets 
in  bleaching,  I  would  earnestly  recommend  the  re- 
petition of  the  following  easy  experiment.  Take 
lialf  a  pint  of  distilled  water — drop  into  it  a  single 
drop  of  the  tincture  of  galls  and  an  equal  quantity 
of  solution  of  sulphate  of  iron,  and  let  the  whol<j 
be  stirred  with  a  glass  rod.  Or.  observing  tlie  ef- 
fect which  this  minute  quantity  of  these  reagents 
has  produced  in  the  water,  it  will  be  perceived  that 
only  a  very  slight  change  of  colour  has  been  occa' 
sioned  by  it ;  whereas,  if  an  equal  quantity  of  spring 
water  be  added  to  the  former  mixture,  tite  whole 
will  immediately  become  black. 

In  some  processes  of  calico-printing  tlie  perfec- 
tion of  the  water  is  of  great  moment,  and  to  the 
dyer  of  tine  colours  pure  water  is  indispensable ;  but 
the  case  which  has  just  been  related  refers  chiefly 
to  the  bleaching  of  linen  and  calicoes,  which  can 
never  take  a  perfect  white  if  the  water  employed  be 
contaminated  with  saline  substances  or  with  mine- 
rals of  a  metallic  nature.  The  term  pure  water  is 
not  intended  to  be  taken  in  the  strictest  sense  of  the 


**  Penons  deairoufl  of  solving  lhi»  problem  may  cotiRult  the 
Second  Book  of  Newton's  Prinri/Jio;  Betidor'n  Arehilecture 
Ifydraitliijue ;  Roberlion  in  the  Philottpliical  Traniaetion*  tot 
I  lis ;  or  a  DUiertatum  on  the  Forte  of  Hunn'mg  Water.  \n  a 
volume  of  "  DineTlatioiu  on   Rural  Suljecls,  8vo,  prini«d  for 


8^6  ON   WAT£R. 

WHfds,  for  nia  water  itself  is  iiot  absdutdjr  pun; 
SMti' water,  fi4i«n  coUeoted  by  spouts  from  the  tops 
of  buildings,  b  found  to  have  dissolved  a. portion  of 
sdlenite  froib^the  tiks ;  and  if  caught  in  an  open 
MA^  it  is  gentrallf  contaminated  by  the  heterogo* 
neow  partider  which  are  always  flimting  ia  the  at* 
nMB|>here.  For.  the  purposes. of  chemical  anal)^ 
nMlring  can  be  depended  opon  but  distilled  waftsv. 
Tte  ancient  chemists,  howeirer,  always  picfemA 
nnn  water  for  all  their  processes. 

In  reference  to  bleaching  it  may  he  worth  while 
t6  mention,  that  there  are  many  manufacturing,  di- 
stikts  in  this  kii^om  which  are  situated  near  to 
peat  mosses,  some  of  which  are  of  consideraUe  flK« 
tent;  and  that  all  such  places  are  very  improper  Son 
the  establishment  of  bleach-works,  because  at  flood 
time  these  marshes  pour  into  the  a^yacent  riws 
large  quantities  of  iron  in  a  state  of  solution  wUdi 
contaminate  the  waters  for  many  miles. 

A  remarkable  instance  of  the  impurity  of  spring 
water  occurs  in  PortugaL  In  several  parts  of  that 
kingdom  the  waters  are  so  hard  that  for  many  pur* 
poses  they  are  entirely  useless.  The  following  is 
a  case  of  peculiar  difficulty. 

The  wool  which  is  produced  in  Spain  and  Bo^ 
tugal  contains  so  much  animal  oil  and  other  im* 
purities,  that  when  scoured  it  will  not  produce  more 
than  half  its  original  weight,  and  in  some  cases 
three  pounds  will  not  'yield  more  than  one  pound 
of  clean  wool  fit  for  the  English  market.  As  these 
wools  pay  a  considerable  duty  to  the  Spanish  and 


ON  n-ATERl  OBPI- 

Portuguese  Governments  on  their  exportation,  the 
Spaniard  finds  it  his  interest  to  clean  them  tho- 
roughly before  they  are  shipped  for  sate  to  Britain 
or  elsewhere ;  but  in  Portugal  tlie  merchant  cannot 
avail  himself  of  this  expedient,  because  the  waters 
of  that  country  are  unfit  for  the  operation. 

I  know  a  merchant  who  has  an  establishment  in 
Portugal  for  the  purchase  of  wool  and  for  the  sale 
of  English  woollen  cloth,  and  he  informs  me  that  he 
is  under  the  necessity  of  shipping  very  large  parcels 
of  wool  in  its  original  state,  which  occasions  a  great 
reduction  of  profit,  merely  for  want  of  the  means 
of  having  this  wool  properly  washed  in  Portugal. 

i  suggested  to  thia  gentleman  the  scheme  of  col- 
lecting urine  for  the  purpose.  I  stated  that  this 
fluid,  when  it  becomes  stale,  produces  a  large  por- 
tion of  volatile  alkali,  and  that  the  addition  of  a 
small  quantity  of  quick  lime  would  remove  its  of- 
fensive smell  and  render  it  fit  for  any  operation  of 
washing  or  scouring:  and  that  it  would,  if  added 
in  a  aiuall  proportion  to  hard  water,  render  such 
water  soft  imd  fit  for  any  detersive  process  what- 
erer.  But  he  assured  me  that  this  could  not  be 
done;  for  that  the  inhabitants  of  this  country  have 
so  much  pride,  and  so  little  idea  of  the  importance 
of  manufactures,  or  of  any  economical  improve- 
ments, that  it  would  be  impossible,  by  any  re- 
ward, to  induce  the  poorest  man  In  the  country  to 
engage  in  such  an  occupation. 

The  ancient  Romans  had  recourse  to  urine  for 
seauripg  woollen  cloths.     It  is,  indeed,  probable 


378  ONi  WAT£m. 

that  it  was  more  largely  employed  by  tbem  for  drii 
purpose  than  even  by  the  modems^  from  the  cb- 
etimatance  of  the  Emperor  Vespasian  hai^diig  liid 
a  tax  upon  it,  which  remained  long;  ior  Ibroe^  and 
oontinued  to  be  exacted  for  more  than  SOO  yeaii* 
The  scourers  of  old  were  so  eareftil  vMh/e  ooUaeiidIi 
of  this  article,  that  the  Government  exfmted  the  pay- 
ment of  the  tax  even  from  those  who  kept^erttle, 
veeiigalpro  urma  jmmenicrum.  Athanasinai  hew* 
ever,  although  he  was  the  most  frugal  and  econo- 
mical of  all  the  Roman  emperors,  rdieved  his  peo- 
ple from  this  odious  impost  ^. 

It  is  probable  diat  the -ancients  had  no  in- 
ception of  the  method  above  mentioned,  of  aweel- 
ening  stale  urine,  because  it  appears  tfiat  tiie 
scourers  at  Rome  were  all  obliged  to  reside  in  the 
most  unfrequented  parta  of  the  city  ^. 

The  fullers  of  doth  and  scourers  of  wool  in  an- 
cient Rome  consid^^  this  article  to  be  so  impdr* 
tant  and  necessary  for  the  support  of  their  respec- 
tive occupations,  that  they  contrived  a  variety  iA 
methods  of  collecting  it,  all  which  may  be  seen  in 
the  xxviiith  book  of  Pliny's  Natural  History. 

In  returning  from  this  digression  to  the  recon- 
sideration of  the  nature  of  spring  and  river  water, 
it  may  be  observed  that  the  instance  which  has  been 
adduced  of  the  difficulty  there  is  in  cleansing  wod 

^  duetoniu8*a  Life  of  Ve^^anan,  §  23. 
^  Gibbon,  vol.  vii.  octavo  edit.  p.  101.    Bedunaiui,  foL  in. 
page  251. 
^.  PUny,  Vb,  xxviii.  §  6  fltc 


r 


OK    WATER.  379 

Trt*  Portygal,  shows  in  &  striking  manner  that  n 
cheap  and  easy  method  of  purifying  the  spring  wa- 
ters of  tliat  country  must  be  n  desideratum  of  great 
national  importance. 

It  is  my  more  immediate  buainess,  however,  to 
direct  iny  attention  to  the  improvement  of  the 
trade  and  manufactures  of  the  British  dominions; 
and  to  this  end  I  shall  proceed  to  give  some  di- 
rections for  the  choice  of  spring  water,  and  shall 
endeavour  to  point  out  some  of  the  best  means 
which  can  be  employed  to  purify  it  for  the  use  of 
manufacturers  or  for  domestic  purposes,  in  those 
situations  where  one  kind  of  water,  and  that  only, 
can  be  easily  obtained  in  sufficient  quantity. 

It  would  extend  this  Bssay  to  too  great  a  length 
to  lay  down  rules  for  the  complete  nnalysis  of  all 
the  various  kinds  of  water  which  these  islands  pro- 
duce, especially  as  Dr.  Kirivan  and  others  have 
mitten  expressly  on  this  branch  of  the  subject: 
but  some  directions  for  ascertaining  tlie  corn/farative 
goodness  of  water  may  be  of  especial  service  to  the 
mamifacturing  part  of  the  community,  and  this 
may  perhaps  be  done  without  occupying  much 
room,  or  occasioning  fotigue  to  the  general  reader; 
and  it  may  be  observed,  as  we  proceed,  that  it  is  of 
consequence  also  to  the  agriculturist  to  be  able,  in 
some  measure,  to  analyse  water ;  for  those  who 
have  studied  the  subject  of  irrigation,  and  carefully 
observed  its  effects,  have  found  that  the  benefits 
resulting  from  th»  _gra(»iw_TOfyimich_d^nd 


380  OK  wATxm. 


upon  the  nature  of  the  water  whirii  is  easploftd^. 
Efen  hones  will  refuse  hard  Water  when!  tbef  have 
long  heen  accustomed  id  soft  **• 

In  examining  water,  the  first  thing  to  be  alf 
tended  to  is  its.  specific  gravity*';  and  I  coochide, 
from  a  remark  which  is  made  bj  PKny^.tbatlUs 
method  of  trying  the  purity  of  viTater  wit  kaoMi 
to  hn  contemporaries.  *'Good  Water,*  ssgra  ht, 
"ought  to  ha?e  neither  tastie  nor  odoor  at  alL 
Some  there  be  who  judge  of  their  wholesomeness 
by  the  balance,  and  they  keep  WdgUng  and  poiziag 
of  waters  one  against  another  '^** 

There  can  be  no  doubt  of  the  importance  <rf  at> 
tending  fo  the  spedfic  gravity  of  spring  or  rivsr 
water,  as  this  alone  will  often  lead  to  a  knowledge 
of  its  nature  and  purity ;  for  those  waters  which  are 
the  most  unfit  for 'culinary  purposesi  or  for  tlie  use 
of  jnanufsdurers,  are  generally  specifically  heavior 
in  proportion  to  their  impurity.  If,  therefore,  a 
samplie  of  water  should  prove  to  be  of  the  aame 
weight,  or  but  a  little  heavier  than  rain  or  diatilled 
water,  and  devoid  of  colour,  taste,  and  smell,  it 
may  generally  be  pronounced  to  be  fit  for  most  pur^ 
poses,  either  of  the  arts  or  of  domestic  economy* 
-  Should  it  be  intended  to  prosecute  the  examina- 
tion further,  it  will  be  an  easy  experiment  to  put  a 


«•  See  BoBweirs  Treatise  an  Watering  Meadows,  p.  10,  &c. 
»  Baynard  an  Cold  Bathi^,Bv6,  London,  1752,  p.  299. 
^  Directionft  for  taking  the  specific  graviw  of  flaids  wiU  be 
found  in  the  Third  Essay,  vol.  i.  p.  1 99—238. 
^^  Holland's  PUny,  book  xxid;  chap.  3. 


OS   WATER, 


3,SI 


thiit  stice  or  two  of  white  soap  into  a  clean  glass 
tumbler,  and  tht- n  to  pour  half  a  pint  of  the  water 
over  it,  which  is  required  to  be  examined.  When 
this  has  stood  undisturbed  far  half  an  hour,  the  ap- 
pearance of  the  water  will  be  a  good  evidence  of  its 
relative  purity,  as  it  will  then  be  seen  whether  it  be 
what  is  called  hard,  and  consequently  impure,  water, 
or  otherwise.  The  Spanish  soap,  usually  known  by 
the  name  of  Castile  soap,  an  article  sold  by  the 
chemists,  and  which  is  made  of  soda  and  oil  of 
olives  or  oil  of  almonds,  is  the  best;  but  good 
English  white  soap  will  generally  be  found  very 
suitable  for  the  purpose.  A  little  Venice  soap  dis- 
solved in  alcohol  will  form  a  test  by  which  the  com- 
parative hardness  of  water  may  be  determined  in  an 
instant. 

Water  which  holds  any  of  the  earths  In  solution. 
or  any  of  the  metallic  or  earthy  s;ilts,  has  the  pro- 
perty of  decomposing  soap,  while  pure  water  will 
completely  dissolve  it.  In  the  former  case  the  alkali 
ceparates,  and  the  earth  combines  with  the  oil  or 
the  tallow ;  in  the  latter,  the  aoap  is  decomposed 
by  double  affinity,  the  acid  uniting  with  the  alkali, 
while  the  earth  or  the  metal  combines  with  the  oil, 
and  forms  an  earthy  or  metaUic  soap.  In  both  in- 
stances the  new  compound  is  insoluble,  which  oc- 
casions the  coagulation  above  mentioned.  It  may 
therefore  be  said  that  in  this  experiment,  if  the  fluid 
present  a  smooth  equable  appearance,  without  any 
white  flakes  or  curdly  particles  interspersed  among 
it,  the  water  may  be  considered  good ;  otherwise  k 


374  ON  WATEH. 

thus  ascertidiied,  the  individfials  above  tefemd  to 
were  at  the  expense  of  conducting  it  in  pipes  far 
three  miles  through  their  own  estate,  takittg  esit 
to  divert  the  waters  of  those  springs  which  contained 
iron  into  another  channel :  the  good  water  wsts  Uide 
to  eniptjr  itself  into  one  vast  cistern,  capable  of  eiW- 
talriing  many  thousand  gallons,  made  with  ilUbt  if 
Scotch  granite  put  together  with  Roman  cmneitt^ 
aiid  securely  puddled  on  the  outside  with  duf*  In 
this  reservoir  there  are  some  contrivances  for  the 
receiving  of  the  wster  and  for  its  delivery  te  Ac 
works,  which  I  intend  to  describe  in  another  piit 
df  this  Essay.  The  construction  of  this  reservmri 
and  the  expense  of  bringing  the  water  from  so  gratt 
a  distance,  amounted  to  more  than  two  thbitwiid 
pounds ;  but  the  advantages  accruing  to  tbe  tnm* 
factory  from  the  possession  of  this  excellent  niter 
have  been  so  great  and  important,  that  some  cf  the 
proprietors  have  informed  me  that  they  have  no 
cause  to  regret  the  amount  of  the  expenditure* 
Independently  of  an  elucidation  of  our  present  sub- 
ject, I  consider  this  to  be  a  striking  inocanoe, 
among  many  others  which  are  daily  occunib|^  of 
the  benefit  derived  to  the  arts  from  the  cultivation 
of  chemical  science. 

I  may  here  remark,  that  in  the  con veyftniie  of 
water  from  a  considerable  distance  it  is  of  great  im- 
portance to  ascertain  how  much  of  that  fluid  a  pipe 
of  a  given  bore  will  deliver  •  in  a  certain  time  ;  be* 
cause  iron  pipes  are  apt  to  oxidize  on  the  inside 
and  contaminate  the  water,  unless  they  be  kept 


ON  WATER,  'A70 

■     M. 

nearly  fiill ;  whereas,  when  they  uie  nut  large 
enough  to  take  off  the  quantity  which  is  thrown 
into  them,  tliey  are  liuble  to  burtit'*. 

To  those  persons  who  liave  no  idea  that  d\i* 
ference  of  water  can  produce  such  important  effects 
in  bleaching,  I  would  earnestly  recommend  the  re- 
petition of  the  following  easy  experiment.  Taite 
lialf  a  pint  of  distilled  water — drop  into  it  a  single 
drop  of  the  tincture  of  galls  and  an  equal  quantity 
of  solution  of  sulphate  of  iron,  and  let  the  whole 
be  stirred  with  a  glass  rod.  Or.  observing  the  ef- 
fect which  this  minute  quantity  of  Uiese  reagents 
has  produced  in  the  water,  it  will  be  perceived  that 
only  a  very  slight  change  of  colour  has  been  occa- 
sioned by  it :  whereas,  if  an  equal  quantity  of  spring 
water  be  added  to  the  former  mixture,  the  wliote 
will  immediately  become  black. 

In  some  proretises  of  cahco-printing  tiie  perfec- 
tion  of  the  water  is  of  great  moment,  and  to  the 
dyer  of  fine  colours  pure  water  is  indispensable ;  but 
the  case  which  has  just  been  related  refers  chiefly 
to  the  bleaching  of  linen  and  calicoes,  which  can 
never  take  a  perfect  white  if  the  water  employed  be 
contaminated  with  saline  substances  or  with  mine- 
rals of  a  metallic  nature.  The  tsTtn  pure  water  is 
not  intended  to  be  taken  in  the  strictest  sense  of  the 


'*  Penons  deairous  of  solving  iWa  problem  may  concuU  the 
Second  Book  of  Newton's  Principia ;  Belidor'B  jtrchilteturt 
Hgdravliquf  ;  Robertson  in  the  Phili>»aphicat  TraiuoflUm*  far 
1738  ;  or  a  DUsertalum  on  the  Force  of  RunniHg  Water,  in  a 
volume  of  "  Disiertaliom  on  Rural  Sulfjecta,  8vo,  pritltwl  for 
-  "        Ht^doB.  1775." 


d^0  ON   WAT£ft. 

tMttds,  'for  nia  water  itself  is  not  absolutdy  pint; 
SMh'  water,  n^tti  coUeoted  by  spouts  from  iJie  tops 
of  buil(Ungs»  is  found  to  have  dissolved  a  portion  of 
s^nite  froitiithe  tiles;  and  if  caught  in  an  open 
fM^  it  is  generallf  contaminated  by  tlie  heteroge* 
nebw  partidesf  which  are  always  flrating  in  die'at« 
niM|>here.  For.  the  purposes. of  chemical  analyw 
Mrtnng  can  be  depended  upon  but  distilled' watw. 
TIfe'  ancient  chemists,  however,  always  piefieneA 
rais  water  for  all  their  processes. 

In  reference  to  bleaching  it  may  he  worth  while 
t6  ^mention,  that  there  are  many  manu&cturing.fi* 
striets  in  this  kingdom  which  are  situated  near  to 
peat  mosses,  some  of  which  are  of  considerable  ea- 
tent;,«0d  that  all  such  places  are  veiy  improper  Un 
the  establishment  of  bleach-worka,  because  at  flood 
tune  these  marshes  pour  into  the  adjacent  riven 
large,  quantities  of  iron  in  a  state  of  solution  whidi 
cdntamiaate  the  waters  for  many  miles. 

A  remarkable  instance  of  the  impurity  of  spring 
water  occurs,  in  Portugal.  In  several  parts  of  that 
kingdom  the  waters  are  so  hard  that  for  many  pur* 
poses  they  are  entirely  useless.  The  following  is 
a  case  of  peculiar  difficulty. 

The  wool  which  is  produced  in  Spain  and  Pop 
tugal  contains  so  much  animal  oil  and  other  un'- 
purities,  that  when  scoured  it  will  not  produce  more 
than  half  its  original  weight,  and  in  some  cases 
three  pounds  will  not  ^yielcl  more  than  one  pound 
of  clean  wool  fit  for  the  English  market.  As  these 
wools  pay  a  considerable  duty  to  the  Spanish  and 


ON  WATEHl  ■  a/^' 

Portuguese  Governments  on  their  exportation,  the 
Spaniard  finds  it  his  interest  to  clean  them  tho- 
roughly before  they  are  sliipped  for  sale  to  Britain 
or  elsewhere ;  but  in  Portugal  the  mercliant  cannot 
avail  himself  of  thi»  expedient,  because  the  waters 
of  that  country  are  unfit  for  the  operation. 

I  know  a  merchant  who  has  an  establishment  in 
Portugal  for  the  purchase  of  wool  and  for  the  sale 
of  English  woollen  cloili,  and  he  informs  me  that  he 
is  under  the  necessity  of  shipping  very  large  parcels 
of  wool  in  its  original  state,  which  occasions  a  great 
reduction  of  profit,  merely  for  want  of  the  means 
of  having  this  wool  properly  washed  in  Portugal. 

I  suggested  to  this  gentleman  the  scheme  of  col- 
lecting urine  for  the  purpose.  I  stated  that  this 
fluid,  when  it  bi^comes  stale,  produces  a  large  por- 
tion of  volatile  alkali,  and  that  the  addition  of  a 
small  quantiiy  of  quick  lime  would  remove  its  of- 
fensive smell  and  render  it  fit  for  any  operation  of 
\TB&hing  or  scouring :  and  that  it  would,  if  added 
in  a  small  proportion  to  hard  water,  render  such 
water  soft  and  ht  for  any  detersive  process  what- 
ever. Bui  he  assured  me  that  this  cnuld  not  be 
done;  for  that  the  inhabitants  of  this  country  have 
so  much  pride,  and  so  little  idea  of  the  importance 
of  manufactures,  or  of  any  economical  improve- 
ments, that  it  would  be  impossible,  by  any  re* 
ward,  to  induce  the  poorest  man  in  the  country  to 
engage  in  such  an  occupation. 

The  ancient  Romans  had  recourse  to  urine  for 
wriog  woollen  cloths.     It  is,  indeed,  probable 


378  ONi  WATER. 

that  it  was  more  largely  employed  by  thfem  fcir  tUi 
purpose  than  eren  by  the  modem9»  from  the  cb- 
etimatanoe  of  the  Emperor  Vespasim  baiviiig  Wd 
a  tax  upon  it,  which  remained  long  in  tone,  and 
oontintied  to  be  exacted  for  more  than  200  yeaii*. 
The  scourers  of  old  were  so  eareftil  in  the  ooUisetidtt 
of  this  article,  that  the  Government  exittrtedtlie  piqf- 
ment  of  the  tax  even  from  those  who  kept^oMki 
veeiigalpro  wnna  jumenierum.  Athanasiu8»  boW« 
ever,  although  he  was  the  most  frugal  and  econo- 
mical of  all  the  Roman  emperors,  rdieved  his  plsa- 
pie  from  this  odious  impost^. 

It  is  probable  diat  the  ancients  bad  no  cm- 
eeption  of  the  method  above  mentioned,  of  sweet- 
ening stale  urine,  because  it  appears  that  the 
scourers  at  Rome  were  all  obliged  to  reside  in  the 
moat  unfrequented  parts  of  the  dty  ^. 

The  fullers  of  cloth  and  sccmrers  of  wool  in  tin- 
cient  Rome  considered  this  article  to  be  so  impor- 
tant and  necessary  for  the  support  of  their  respec- 
tive occupations,  that  they  contrived  a  variety  df 
methods  of  collecting  it,  all  which  may  be  seen  in 
the  xxviiith  book  of  PUny*s  Natural  History. 

In  returning  from  this  digression  to  the  recM- 
ttderaiion  of  the  nature  of  spring  and  river  water, 
it  may  be  observed  that  the  instance  which  has  been 
adduced  of  the  difficulty  there  is  in  cleansing  wool 


t  i 


^  Saetonia8*8  lAfe  of  Veapaman^  %  23. 
^  Gibbon,  vol.  vii.  octavo  edit.  p.  101.    Beckmano^  voL  in. 
pdge251. 
^.  VXxttf,  lib.  xzviii.  (  6  Stc 


r 


ON    WATER.  379 

Iti  Portugal,  sliowB  in  a  striking  manner  that  11 
cheap  and  easy  method  of  purifying  the  spring  wa- 
ters of  that  country  must  be  a  deBideratnm  of  great 
national  importance. 

It  IB  my  more  immediate  business,  however,  to 
direct  my  attention  to  the  improvement  of  the 
trade  and  manufactures  of  the  British  dominions; 
and  to  this  end  I  shall  proceed  to  give  some  di- 
rections for  the  choice  of  spring  water,  and  shall 
endeavour  to  point  out  some  of  the  best  means 
which  can  be  employed  to  purify  it  for  the  use  of 
manufacturers  or  for  domestic  purposea,  in  those 
situations  where  one  kind  of  water,  and  that  only, 
can  be  easily  obtained  in  sufficient  quantity. 

It  would  extend  this  Essay  to  too  great  a  length 
to  lay  down  rules  for  the  complete  analysis  of  all 
the  various  kinds  of  water  which  these  islands  pro- 
duce, especially  as  Dr.  Kirwan  and  others  have 
written  expressly  on  this  bmnch  of  the  subject ; 
bat  some  directions  for  ascertaining  tlie  eompaTat'we 
goodness  of  water  may  be  of  especial  service  to  the 
manufacturing  part  of  the  community,  and  this 
may  perhaps  he  done  without  occupying  much 
room,  or  occasioning  fatigue  to  the  general  reader; 
and  it  may  be  observed,  as  we  proceed,  that  it  is  of 
consequence  also  to  the  agriculturist  to  be  able,  it» 
some  measure,  to  analyse  water;  for  those  who 
have  studied  the  subject  of  irrigation,  and  carehilly 
observed  its  effects,  have  found  that  the  benefits 
rewilting  from  thp ^practice  wry  mudnjiwend 


'380  ON    WAT£E. 

upon  the  nature  of  the  water  which  is  'esiplofad^. 
Even  horses  will  refuse  hard  water  when:  ibey  faavr 
long  been  accustomed  to  soft  **. 

In  examining  water,  the  first  tluog  to  be  at* 
tended  to  is  its  specific  gravity*^;  and  I  eonchule. 
from  a  remark  which  is  made  by  FKnyi  thatthb 
method  of  trying  the  purity  of  UTater  wat  kmnni 
to  his  contemporaries.  **Good  ^^tet^  nys  he, 
"  ought  to  have  neither  taste  nor  odour  at  alL 
Some  there  be  who  judge  of  their  wholesomeness 
by  the  balance,  and  they  keep  woghing  add  poiaag 
of  waters  one  against  anothiBr  'K** 

There  can  be  no  doubt  of  the  importance  of  at- 
tending to  the  specific  gravity  of  spring  or  river 
water,  as  this  alone  will  often  lead  to  a  knowledge 
of  its  nature  and  purity ;  for  those  waters  which  are 
the  most  unfit  for  culinary  purposes,  or  for  tlie  use 
of  manufadurers,  are  generally  specifically  heavier 
in  proportion  to  their  impurity.  If,  therefore^  a 
sample  of  water  should  prove  to  be  of  the  tavse 
weight,  or  but  a  little  heavier  than  rain  or  distilled 
water,  and  devoid  of  colour,  taste,  and  smell,  it 
may  generally  be  pronounced  to  be  fit  for  most  pur^ 
poses,  either  of  the  arts  or  of  domestic  economy* 

Should  it  be  intended  to  [prosecute  the  examina- 
tion further,  it  will  be  an  easy  experiment  to  put  a 


**  See  Boswell's  Treatise  on  fVatering  Meadows,  p.  10,  &c. 
^  Baynard  on  Cold  Bathi^,  6v6,  London,  17S2,  p.  299. 
^  Directiona  for  taking  the  specific  gravity  of  fluids  will  be 
found  in  the  Third  Essay,  vol.  i.  p.  1 99-— 238. 
^^  Holland's  Pliny ^  book  xxxi.  chsp.  3. 


ON    WATER,  y,SI 

'riltn  sKce  or  two  of  white  soap  into  a  clean  glass 
tumbler,  and  then  to  pour  half  a  pint  of  the  water 
over  it,  wliich  is  required  to  be  examined.  When 
lhi»  has  stood  undisturbed  for  half  an  hour,  the  ap- 
pearance of  the  water  will  be  a  good  evidence  of  its 
relative  purity,  as  it  will  then  be  seen  whether  it  be 
what  la  called  hard,  and  consequently  impure,  water, 
or  otherwise.  The  Spanish  soap,  usually  known  by 
the  name  of  Castile  soap,  an  article  !>oId  by  the 
chemists,  and  which  is  made  of  soda  aud  oil  of 
olives  or  oil  of  almonds,  is  the  best;  but  good 
English  white  soap  will  generally  be  found  very 
suitable  for  the  purpose.  A  little  Venice  soap  dis- 
solved in  alcohol  will  form  a  test  by  which  the  com- 
parative  hardness  of  water  may  be  determined  in  an 
instant. 

Water  which  holds  any  of  the  earths  in  solution, 
or  any  of  the  metallic  or  earthy  salts,  has  the  pro- 
perty of  decomposing  soap,  while  pure  water  will 
completely  dissolve  it.  In  the  former  case  the  alkali 
separates,  and  the  earth  combines  with  the  oil  or 
the  tallow  ;  in  the  latter,  the  soap  is  decomposed 
by  double  affinity,  the  acid  uniting  with  the  alkali, 
while  the  earth  or  the  metal  combines  with  the  oil, 
and  forms  an  earthy  or  metaUic  soap.  In  both  in- 
stances the  new  compound  is  insoluble,  which  oc- 
casions the  coagulation  above  mentioned.  It  tnay 
therefore  be  said  that  in  this  experiment,  if  the  fluid 
present  a  smooth  equable  appearance,  without  any 
white  flakes  or  curdly  particles  interspersed  among 
it,  the  water  may  be  considered  good  ;  otherwise  it 


4 


382  ON   WAT£E. 

must  be  deemed  bard,  and  this  in  proportion  to  tfaft 
quantity  of  tbe  white  insoluble  matter  wbi^b  ia.p9^ 
ceived  in  it. 

One  of  the  aubstances  most  commonly  fbimd  ip 
water,  and  the  most  injurious  to  mamifiietuffctiay  is 
iron.  To  discover  the  presence  of  iroOi  pruiaiate 
of  potash,  or  tincture  of  galls,  may  be  empl^yed^ 
The  first  of  these  reagents  will  occasion  a  Urn  co- 
lour in  the  water  if  iron  be  present ;  the  tinctuie 
of  galls  will  produce  at  first  a  purple  and  dien  a 
black  tinge. 

These  short  directions  will  be  enough,  to  enable 
manu&cturers  in  general  to  ascertain  whether  tbe 
water  in  thdr  vicinity  has  a  d^ree  of  purity  suf- 
ficient for  their  respective  purposes :  and  wherever 
a  complete  analysis  is  required,  recourse  must  be 
bad  to  Kirwan  »,  or  to  some  other  chemical  writer 
who  has  given  the  proper  directions  for  conducting 
such  an  examination*  In  pursuing  this  inc^uii]^ 
*'  Bergman*s  Physical  and  Chemical  Elssaya,'*  '*  Ik, 
Henry's  Elements  of  Experimental  Ciiemistry,** 
^'Dr  Thomson's  and  Murray's  Systems  of  Che- 
mistry," and  the  fourth  volume  of  '^  Fourcroy's 
General  System  of  Chemical  Knowledge,**  may  aU 
be  read  with  advantage. 

It  may  however  be  worth  while  to  embrace  this 
opportunity  of  showing  that  brooks,  rivers^  and 
springs,  are  liable  to  be  contaminated  with  a  variety 


^  See  An  Essai/  an  the  AnalysU  of  Mineral  Watert,  \rf  Ridiard 
Kirwan,  Em].  F.R.S.  8to.    London,  1799. 


OM  WATSft*  388 

of  impurities,  ell  of  wbicll  may  be  detected  bj  che- 
nMl-retgentB  in  the  fbUowiog  order.  Other  sub* 
ttaocesbowever,  besidestboie  which  are  enumerated 
ia  the  aobjaiwd  list,  have  been  found  in  nataral 
WBtfTS  t  but  as  these  are  aueh  as  are  chiefly  to  be 
it  bas  not  been  tfaougfat  necessary  to 
etbe  oatak^e. 

flats'  .|f|||-^| 

£    :  i  8 
3    :  '• 


2  »  ^5,s=-?      " 


a  _ 


**  Thia  of  test  magnenia  wan  fint  Kcommended  b/  Dr. 
WollMton.  For  the  method  of  nuuui^Dg  it,  see  Dr.  Mebfy's 
CkMtHry,  vol.  ii.  page  431 . 


384  ON  WATER. 

The  manufacturer  having  ascertuned^  by  means 
of  one  or  more  of  these  tests,  that  the  water  upon 
his  premises  is  not  fit  for  his  purpose,  it  then  be- 
comes a  question  of  prudence. whethcsr  he  shall 
attempt  to  purify  thb  water,  or  search  for  aome 
other  source  from  whence  he  may  draw  aoch  nrb 
naturally  pure  enough  for  the  use  of  his  mami- 
factory. 

It  is  probable  that  in  many  parts  of  this  kingdom 
such  a  search  would  be  crowned  with  success.  Dr. 
Home  has  stated  that  **  the  water  of  the  Edinburgh 
wells  not  only  thoroughly  dissolves  soap,,  and  retains 
its  transparency  when  salt  of  tartar  is  mixed  with 
it,  but  even  shows  no  lactescency  when  nitrate  of 
mercury  is  dropped  in*^/* 

The  means  which  might  be  adopted  for  the  puri- 
fication of  water  are  various,  and  nature  lierself 
makes  use  of  several  of  them  in  order  to  present  os 
with  this  article  of  the  first  necessity,  in  a  state  of 
sufficient  perfection  for  all  the  common  purposes 
of  life ;  and  among  other  operations  she  chiefly  em- 
ploys those  of  distillation  and  filtration. 

The  most  contaminated  waters  on  the  face  of  tbe 
earth  are  daily  purified  by  the  action  of  the  8un*s 
beams,  which  separate  the  limpid  particles  from 
the  polluted  mass  and  elevate  them  into  clouds, 
from  whence  they  are  distilled  in  showers  of  nun, 
hail  or  snow.  The  hills  and  mountains  of  the 
globe  also  perform  a  similar  office,  by  allowing  tbe 
waters  in  their  vicinity  to  percolate  through  them, 

'•  Home*8  Experiments  on  Bleaching,  p.  252. 


ON  WATER.  3SS 

and 'hence  are  presented  to  us  in  various  degrees 
6f  piirkjr,  atiscordhig  to  the  nature  of  the  dtffeifent 
strata  of  earths  or  minerals  through  which  they 
have  permeated  ^. 

The  former  of  these  methods  is  successfully  imi- 
tated whenever  we  prepare  distilled  water ;  but  thid 
k  ar  procicss  which  is  too  expensive  for  most  manu« 
bcturing  purposes.  The  latter,  that  of  percolation, 
majF  be  copied  by  art  on  a  large  scale ;  and  the 
wMer  which  is  thus  purified,  may  be  employed  for 
abme  tises  wi£h  considerable  advantage.  Here^ 
however,  we  can  only  strain  off  some  common  con* 
tii^ofit  matters  without  changing  the  soluble  prin* 
^plte  ;  while  nature,  by  her  superior  powers,  can 
even  decompose  what  is  injurious,  and  cause  the 
iiA|mrities  to  subside  or  separate  entirely. 

I  have  often  thought  that  at  those  large  works 
where  a  steam-engine  is  constantly  employed,  a  suf<> 
fideat  quantity  of  distilled  water  for  all  the  nicer 
purposes  might  be  collected  from  the  waste  steam,  if 
a  proper  receptacle  were  contrived  for  condensing  it. 
The  advantages  that  would  accrue  from  such  an  ar- 
ntDgement  to  the  dyer  of  rich  colours,  and  to  the 
printer  of  fine  calicoes,  are  incalculable. 

Here  it  may  be  observed,  that  when  fresh  water 
becomes  scarce  at  sea,  excellent  soft  water  may  be 
raadily  procured  for  the  use  of  the  ship's  crew,  by 
diBtilling  the  salt  water  With  some  wood-rashes  or 

^  Those  springs  which  arise  out  of  limestone  rocks  are  ge- 
nerally hard ;  whereas,  the  waters  which  have  filtrated  through 
a  long  extent  of  gravel  are  often  extremely  soft. 

VOL.  II.  2  c 


386  ON   WATER. 

Other  vegetable  alkali.  A  memoir  expressly  on 
this  subject  may  be  seen  in  the  Philosophical 
Transactions  for  the  year  1758. 

I  had  some  time  since  an  opportunity  of  ex- 
amining the  plan  of  an  extensive  reservoir,  at  that 
time  making  by  a  very  ingenious  manufacturer  for 
the  sole  purpose  of  filtrating  tvater,  and  which  was 
pf  the  enormous  size  of  sixty  yards  long  and  forty 
yards  wide.  This  vast  receptacle  was  formed  near 
the  side  of  a  river,  and  sunk  several  feet  below  the 
surface  of  the  adjacent  ground.  When  the  Ml 
had  been  carried  out  to  a  depth  which  was  thoogfai 
sufficient,  several  broad  trenches  were  sunk  a  foot 
or  two  deeper  than  the  main  bottom,  and  these 
were  filled  with  boulder  stones  or  very  large  pebUea^ 
to  prevent  the  possibility  of  these  passages  for  the 
water  from  ever  being  filled  up.  Over  these,  and 
over  the  whole  bottom  of  the  reservoir,  a  large  bed 
of  gravel  was  laid,  and  then  the  remainder  of  the 
pit  was  filled  up  with  fine  screened  sand. 

In  using  this  reservoir,  it  was  the  intention  of 
the  proprietors  to  fill  it  with  water,  by  means  of  a 
pump  fixed  within  the  river,  and  worked  bytb^ 
steam-engine ;  and  it  was  considered  that  the  water 
would  be  purified  in  its  passage,  while  pervading 
the  sand  and  gravel ;  that  the  trenches  below  would 
be  constantly  full  of  pure  water,  and  that  the  manu- 
factory would  be  furnished  with  a  perpetual  and 
transparent  limpid  stream^ 


,87 


^'  The  waters  of  the  Seine  arc  purified  somewhat  in  this  way 
for  the  use  of  the  inhabitants  of  Paris.  The  Egyptians  purity 
their  river  water  with  alum. 


OS  WATER.  387 

I  have  not  yet  heard  of  the  success  of  this  pro- 
ject, but  I  have  no  doubt  of  its  answering  fully  all 
the  expectations  of  the  projectors:  though  it  must 
be  recollected  by  those  who  may  be  desirous  of  prac- 
tising this  mode  of  purification,  that  it  is  only  ca- 
pable of  separating  the  argillaceous  earth,  or  such 
impurities  as  are  merely  suspended  in  the  water, 
and  not  any  of  the  earths  or  salts  which  are  chemi- 
cally combined  or  dissolved  in  it. 

In  making  a  reservoir  of  this  kind,  there  are  many 
circumstances  to  be  attended  to,  wliieh  may  appear 
insignificant  in  themselves,  and  yet  the  neglect  of 
one  of  them  may  be  sufficient  to  defeat  the  whole 
of  the  intention.  Thus,  if  precautions  are  not  taken, 
worms  will  burrow  through  the  bottom  and  sides 
of  sucb  receptacles,  and  by  the  passages  thus  form- 
ed will  divert  the  water  from  the  bed  of  the  filtrat- 
ing materials  into  other  channels. 

To  guard  against  this,  it  is  necessary,  when  the 
bed  of  the  reservoir  has  been  well  puddled  witii  clay, 
to  lay  a  thin  coat  of  coal-ashes  o\ev  it,  and  to  secure 
the  sides  in  the  same  manner ;  it  having  been  found 
that  this  will  effectually  prevent  these  small  animals 
from  penetrating. 

It  13  also  necessary,  when  the  gutters  are  filled 
with  the  boulder  stones,  to  cover  them  with  long 
straw  to  prevent  tlie  gravel  from  running  among 
them.  The  same  expedient  should  likewise  be 
adapted  afterwards,  when  all  the  gravel  has  been 
laid  on,  to  prevent  the  sand  which  is  then  to  be 
1  over  from  running  among  it ;  but  where  a 
2  c  2 


388  ON  WATER. 

large  sum  is  to  be  expended  in  one  of  these  reser- 
Toirs,  I  would  earnestly  recommend  that  the  adviee 
of  a  person  should  be  taken  who  has  had  e^qperienct 
in  these  matters. 

.  In  pursuing  the  subject  of  purifying  waters  fiir 
(he  use  of  pur  respective  manufactories,  I  mniU 
i^emark  that  it  is  right  to  encourage  the  growth  of 
weeds,  and  the  different  kinds  of  aquatic  v^etable% 
in  all  large  reservoirs  of  water  belonging  to  so^ 
establishments,  as  they  have  the  faculty  of  vecy  ma- 
terially purifying  the  water  in  whidi  thqf  gnm* 
Some  very  interesting  dissertations  oa  thia  imbjeet 
will  be  found  in  Priestley's  Experiments  on  Air,  &a 
under  the  article  «  G«..n  vegetable  matter  fl<»tu« 
on  stagnant  water  «.''    Hard  waters  have  the  pro- 
perty of  retarding  animal  and  vegetaUe  pntveCie* 
tion ;  but  when  putrefaction  does  take  place  ia  soidi 
waters,  it  alters  their  quality,  and  they  become  ptt^ ' 
tirely  soft  ^.    The  antiseptic  quality  of  hard  waCeis 
was  known  to  Celsus,  an  eminent  physician  of  the 
first  century.    "  If  this  were  the  proper  place,**  sqfs 
Dr.  Home,  **  we  could  easily  account  for  all  the  bad 
effects  of  hard  water  on  the  human  body ;  and  show 
that  by  the  separation  of  the  acid  from  the  t^iepr 
trial  base,  which  will  happen  in  the  body,  seversl 
diseases  must  arise.    These  unwholesome  effects  of 
hard  water  may  be  pri^vented  by  previously  mixing 


^  See  the  5th  vol.  of  Priestley's  Experiments  on  Air,  being 
the  second  of  his  Observations  on  Natural  Philosophy,  Binnin|^ 
ham,  octavo,  1781,  p.  16 — 63. 

^'  See  Dr.  Home's  Treatise  on  Bleaching,  p.  229. 


OYI  WAT£il.  389 

alkaline  salts  with  it  '^.  Some  waters  are  purified 
sufficiently  for  manufacturing  purposes,  merely  by 
an  exposure  to  the  action  of  the  atmosphere.  Thus, 
some  chalybeate  waters  deposit  the  iron  id  a  thin 
pdlicle  on  their  surface,  owing  to  its  becoming  in- 
soluble by  its  absorption  of  oxygen.  I  know  also 
of  an  instance  at  a  print  work,  where  a  very  shallow 
itream  of  water,  which  ran  through  the  works,  was 
ftnind  too  impure  for  many  of  their  purposes ;  but 
when  the  same  rivulet  had  passed  these  premises, 
and  had  reached  another  work  which  belonged  to 
the  same  proprietors,  situated  at  a  considerable  di- 
stance from  the  former,  it  was  always  found  to  be 
6t  for  most  of  their  operations. 
'  A  large  portion  of  the  spring  water  of  this  coun- 
try is  tendered  unfit  for  many  manufacturing  pur- 
|MNies  by  the  selenite  which  is  contained  in  it ;  but 
surely  such  water  might,  at  a  trifling  expense,  be 
sufficiently  purified  for  most  occasions,  unless  the 
eonsumption  of  it  were  so  large,  as  that  this  cir- 
iromstance  alone  would  create  an  insurmountable 
{Ejection. 

Water  contaminated  by  selenite  (sulphate  of  lime) 
may  be  rendered  pure  by  means  of  a  solution  of 
barytes  **,  an  article  which  may  be  prepared  at  a 
toroparatively  small  expense,  and  would  be  of  in- 
ealculable  advantage  in  many  processes  of  art.     I 


^  Home*s  Experments,  pa^  295. 

♦'  For  the  method  of  keeping  barytes  in  a  state  of  purity, 
tee  Essay  V.  vol.  i.  page  344. 


390  ON  WATER. 

have  here  in  view  the  preparation  of  barytic  eirtfa 
from  the  common  Derbyshire  cauk.  as  described  in 
vol.  i.  p.  361,  and  which  I  conceive  would  be  suffi- 
ciently  pure  for  this  purpose.  All  that  would  be 
necessary  would  be  to  drop  the  solution  of  that 
earth,  by  degrees,  and  in  small  portions,  into  the 
water  intended  to  be  purified,  till  it  occasions  no 
further  precipitate.  In  this  way  pure  water  might 
at  any  time  be  had  for  chemical  experiments ;  for, 
if  too  much  of  the  barytic  solution  should  by  aoci- 
dent  be  employed,  the  carbonic  acid  inherent  in  the 
water,  or  that  of  the  atmosphere,  will  soon  combine 
with  it,  and  occasion  it  to  precipitate  along  with  the 
decomposed  selenite.  I  cannot  however  recomroted 
the  water  purified  in  this  way  to  be  used  for  domes- 
tic purposes,  as  the  barytic  earth  is  poisonous. 

When  barytes  is  not  to  be  had,  and  in  all  cases 
where  it  would  be  improper  to  employ  that  earth, 
such  water  may^  be  rendered  soft,  though  not  per- 
fectly pure,  by  the  addition  of  a  small  quantity  of 
the  sub-carbonate  of  potash  (the  pearlash  of  the 
shops)  or  a  few  of  the  crystals  of  soda.  Either  (tf 
these  alkalies  will  combine  with  the  sulphuric  acid 
and  precipitate  the  lime ;  and  when  a  sufficient  time 
has  been  allowed  for  the  deposit  to  be  formed,  sueh 
water  will  be  fit  for  every  culinary,  and  for  most 
manufacturing  or  domestic  purposes.  Where  there 
is  the  convenience  of  proper  reservoirs,  this  is  a 
most  effectual  way  of  softening  hard  waters ;  and 
for  every  purpose  of  washing  or  scouring,  the  effect 
may  be*  produced  at  a  still  cheaper  rate  by  means  of 


^^*  ON  WATER.  391 

stale  urine.  This  might  be  sweetened  as  directed 
at  page  377,  and  then  poured  into  the  water  by  de- 
grees tilt  the  object  was  completely  attained. 

The  great  desideratum,  however,  with  bleachers, 
dyers,  and  caiico-printers,  is  to  discover  a  cheap 
method  of  precipitating  iron  from  any  of  those  wa- 
ters in  which  it  may  be  dissolved,  as  the  salts  of  iron 
held  in  solution  by  the  waters  of  brooks  and  rivers 
are  often  very  injurious  in  the  practice  of  those  tirts. 

The  solvent  of  the  iron  in  these  cases  is  often,  if 
not  generally,  sulphuric  acid ;  therefore,  in  those 
situations  where  it  is  convenient  to  have  cisterns  or 
other  reservoirs  for  the  water,  the  solution  of  pure 
barytes  might  be  employed  with  equal  effect.  The 
barytic  earth  would  immediately  seize  the  sulphuric 
acid  and  precipitate  it;  and  the  iron,  having  thus 
lost  its  solvent,  would  fall  also.  This  precipitation 
of  these  impurities  will  commence  immfdiately  upon 
tlie  application  of  the  barytes :  and  when  the  whole 
has  remained  a  few  hours  undisturbed,  the  water 
will  be  6t  for  use.  It  will  be  obvious  that  care  must 
be  taken  to  add  no  more  of  the  barytic  solution 
than  is  absolutely  necessary  to  throw  down  the  iron ; 
otherwise,  when  the  iron  has  been  separated,  the 
water  will  be  found  to  be  contaminated  by  the  re- 
agent itself.  In  Scotland  the  poor  get  up  their 
own  household  linen,  and  bleach  it  themselves  in 
their  own  gardens.  Dr.  Home  relates  the  case  of 
a  poor  woman  who  watered  some  webs  she  was 
bleaching,  from  :t  spring  near  her  own  housi-.     To 


302  (W  WATUI» 

ber  greiat  ^uirprise,  they  became  redder  jmd  roMer 
evj^ry  dfiy.  ^e  atiribut€d  it  to  witchcraft ;  iraputad 
the  crime  to  the  neighbour  she  hated  moat ;  and 
9okl  the  cloths  for  a  trifle.  The  Doctor  itfterwalrds 
analysed  the  water,-  and  found  it  imitained  iram 
To  discover  whether  the  iron  be  hdd  in  sidutiott 
by  the  sulphuric,  the  muriatic,  or  the  carbonic  aeid^ 
treat  it  with  a  small  quantity  of  the  nitrate:  of  ;ha^ 
rytes.  If  this  throws  down  a  yellow  preci[nlatei 
and  the  water  loses  its  bvackiah  taste,  it  may  be  con- 
cluded that  the  iron  is  dissolved  by  tbe  former  of 
these  acids ;  but  if  these  effects  are  not  producfid* 
some  other  acid  must  be  considered  to  be  the  aolr 
veDt .  .Boiling  the  water  will  show  whether  it  is  ear^ 
bbnic  acid  that  holds  it  in  solution.  «. 

In  cases  where  no  danger  would  arise  hom-M 
small  portion  of  lime,  waters  may,  indeed,  be^  di- 
vested of  iron  merely  by  the  addition  of  a  little  oi 
this  earth  in  powder  ^'.  It  would  be  proper  to  use 
fresh  burnt  lime ;  and  should  more  of  this  be  eoH 
ployed  than  is  necessary  to  separate  the  iron,  the 
superabundant  quantity  may  be  precipitated  by  at 
lowing  it  time  to  absorb  carbonic  acid  £rom  the  at^ 
mosphere.  And  where  time  could  not  be  spared 
for  the  completion  of  this  process,  the  ju^cious  ap- 
plication of  a  very  small  quantity  of  sulphuric  add 
would  separate  the  whole  in  the  course  of  twen^- 


^*  Pliny  speaks  of  purifying'brackish  water  with  chalky  whicli 
is  a  subcarbonate  of  lime.'  See  lib.  xxiv.  cap.  1 . 


ON  WATER.  303 

fanrlibtiny  and  leave  the  mass  of  water  in  a  state 
of  fionty  fit  for  any  purpose  either  of  manu&cture 
Of  ddmestic  economy. 

To  accomplish  this  on  a  large  scale  it  will  be  ne^ 
oe>iary  to  have  two  reservoirs,  which  might  adjoin 
eaek  other»  and  then  the  impurities  would  be  sub* 
aiding  in  one»  and  its  water  becoming  fit  for  use  by 
tbetime  the  water  of  the  other  was  expended. 

From  repeated  observations  I  am  convinced  that 
hatge  sums  of  money  have  been  needlessly  spent  in 
Ae  purchase  of  expensive  cements  for  making  un- 
dei^ound  water*  cisterns,  and  that  brick  walls  pro- 
pady  built  and  well  puddled  with  clay  are  fully  suf* 
fident  for  the  purpose.  I  have  myself  more  than 
OBce  eonstructed  a  large  underground  cistern  in 
Hib  manner,  which  held  perfectly  tight  for  several 
ymiBf  and  probably  would  last  at  least  a  century. 
A  detail  of  the  methods  which  I  pursued  would  ocr 
eapy.  more  room  than  I  can  spare ;  but  I  refer  the 
leader  to  a  work  where  he  may  obtain  an  abund- 
ance of  useful  information  on  this  subject,  vul 
fiwitzer's  System  of  Hydrostatics,  in  2  vols,  quarto, 
London  1729,  vol.  i.  p.  1 29,  illustrated  with  a  cop- 
per-plate engraving  of  the  sections  of  several  reser- 
voirs of  different  forms  and  dimensions.  Vitruvius 
WKfB  that  the  ancients  constructed  their  underground 
mstems  with  a  composition  made  of  lime-mortar, 
«nd  and  pebbles,  well  beaten  together  ^. 

The  reservoir  mentioned  at  page  374,  and  formed 

*^  Vitruv.  dc  ArchiUciura,  lib.  viii.  cap.  6. 


394  ON    WATER. 

for  the  use  of  a  large  print  work  and  bleaching  es* 
tablishment  in  the  north  of  Scotland,  was  confltnicl- 
ed  with  a  different  intention.  This^was  designed 
chiefly  to  form  a  receptacle  for  purer  water  than  tibat 
which  they  had  been  accustomed  to  use»  and  aho 
that  the  water  to  be  employed  in  the  manafiMtoiy 
should  be  constantly  exposed  to  the  purifying  infltt- 
ence  of  the  atmosphere.  It  were  wdl  if  all  our  mar 
nufacturers  were  equally  circumspect. — In  China 
there  is  a  certain  lake  surrounded  with  villages  and 
full  of  inhabitants,  who  are  absolutely  drawn  ihitfaer 
by  a  persuasion  that  the  silk  washed  in  that  lake  de> 
rives  from  thence  a  lustre  not  to  be  obtained  in  any 
other  way**. 

Since  the  former  part  of  this  Essay  was  written, 
I  l>ave  been  favoured,  by  one  of  the  proprietors  of 
the  reservoir  just  alluded  to,  with  a  particular  ae- 
count  of  its  construction,  and  also  of  the  expedioDts 
they  adopted  in  order  to  procure  a  regular  suj^y 
of  water,  and  have  it  delivered  to  the  works  in  a 
state  of  sufficient  purity  for  all  their  purposes. 

The  reservoir,  which  is  formed  with  large  slabs 
of  Scotch  granite,  put  together  with  Parker's  oe* 
tnenty  is  fifty  feet  long,  thirty  feet  wide,  and  ten 
feet  deep.  This  receptacle  is  filled  with  water  con- 
veyed thither  by  iron  pipes,  from  a  spring  at  three 
miles  distance,  the  water  of  this  spring  having  been 
found  to  be  the  purest  of  any  in  the  neighbourhood. 

It  is  observable  that  the  reservoir  is  very  shallow 

^*  Du  Halde,  Description  dc  V Empire  dc  la  Chine,  torn.  i. 
p.  127. 


ON    WATEil.  305 

in  comparison  with  its  extent,  and  tliis  form  was 
given  to  it  in  order  that  a  large  surface  of  water 
should  be  constantly  exposed  to  the  atmosphere. 
The  design  of  tliis  will  be  immediately  perceived, 
when  it  is  understood  that  tliis  water  passes  through 
a  bed  of  lime-stone,  and  that  when  it  is  delivered  at 
the  reservoir  it  holds  a  portion  of  that  earth  in  so- 
lution. For  by  this  exposure  of  it  to  the  air,  it 
loses  that  excess  of  carbonic  acid  which  dissolved 
the  carbonate  of  lime,  and  then  this  earth  from  ita 
natural  insolubility  separates,  and  falls  to  the  hot- 
tom  of  the  cistern.  Mr.  Cavendish  determined 
that  1200  grains  of  water  impregnated  with  fixed 
air  and  yet  not  fully  aerated,  coidd  hold  in  solution 
one  grain  of  challf.  Berthollet  in  M^m.  Paris. 
1780,  p.  127,  states,  that  500  grains  of  water/w/Zy 
impregnated  with  fixed  air  can  hold  one  grain  of 
aerated  lime;  and  Kirwan  has  shown,  that  when 
the  proportion  of  water  to  that  of  chalk  is  very  con- 
wderable,  for  instance,  as  12,000  to  one,  then  the 
weight  of  fixed  air  necessaiy  to  keep  the  lime  in  so* 
lution  is  about  half  its  weight  when  aerated  ;  and 
if  the  proportion  of  water  be  still  more  considerable, 
a  stiU  smaller  weight  of  fixed  air  is  required.  He 
also  states,  thqt  if  the  weight  of  the  carbonic  acid 
which  is  united  to  water  exceeds  that  of  the  chalk, 
it  will  dissolve  it  let  its  volume  with  respect  to  that 
of  the  water  be  ever  so  small ".  It  having,  however, 
been  foreseen  that  the  precipitate  of  calcareous 


'  Kirwan  on  Hie  .Uali/vi  "f  Mineral  Ifaltr,  page  20. 


396  OK  WATER;; 

ear^  wotild  oon^ntly  aocumiilate  in  'An  Toer* 
voir,  and  soon  becomie  considerable,  the  water  from 
the  pipe  of  conveyance  is  not  allowed  to  nush  hk  at 
the  suT&ce,  but  is  deli^red  into  a  ci^cious  woodMf 
trough  which  goes  nearly  to  the  bottom  of  the  cistern. 
By  this  contrivance  no  water  can  enter  but  iett  thi  bot^ 
torn,  and  there  it  becomes  distributed,  without  oosih 
sioning  the  least  disturbance  to  the  surfece ;  wlnrii 
is  a  point  of  ^considerable  consequence,  especiaHym 
the  manufactory  is  supplied,  as  will  be  explained 
hereafter,  only  from  the  uppermost  stratum. 

At  first  an  inconvenience  arose  from  the  circim* 
stance  of  conveying  the  water  from  the  spring  in 
iron  pipes,  as  those  parts  which  were  not  constimdy 
covered  with  water  became  oxidized  by  the  action 
of  the  atmosphere!  and  in  consequence  of  this  the 
contents  of  the  reservoir  were  soon  contaminated 
by  iron  in  a  considerable  degree.  However^  by 
adapting  a  stop-cock,  and  otherwise  preventing  ibe 
circulation  of  air  within  the  pipes,  the  iron  is  nbw 
presetved  from  solution,  and  the  complaint  of  having 
a  chalybeate  water  is  no  more  heard. 

It  being  a  main  object  with  the  proprietors  of 
this  manufactory  to  improve  the  water  by  expo^g 
it  to  the  action  of  the  air,  in  the  way  already  noted, 
they  conceived  that  the  upper  stratum  must  always 
be  the  purest,  and  therefore  they  determined  nev^ 
to  draw  any  off  for  the  use  either  of  bleaching  or 
calico  printing  but  from  the  ^rface,  and  this  tb^ 
effect  by  the  following  expedient. 

A  copper  pipe,  with  a  large  stop-cock  attached 


ON    WATElt.  397 

to  it,  Is  firmly  fixed  in  one  side  of  the  reservoir,  at 
a  convenient  distance  front  the  bottom  ;  and  at  that 
end  of  the  pipe  which  is  within  the  water,  a  fleidble 
tube  of  leather  about  1 8  inches  long  is  affixed  and 
supported  upon  rings  of  copper,  sewed  withinside 
to  prevent  the  pressure  of  the  water  from  occasion- 
ing the  leather  to  collapse.  It  will  be  obvious  that 
where  the  water  is  not  to  be  consumed  close  to  the 
reservoir,  a  series  of  pipes,  instead  of  the  stop-cock, 
might  be  attached  to  the  flexible  tube,  and  thus  the 
water  might  be  conveyed  to  anyjiistance.  To  the 
other  end  of  tliis  flexible  pipe,  one  of  copper  is  fixed, 
with  a  rose-head,  as  it  is  called,  at  tlie  other  extre- 
mity ;  that  is,  this  end  of  the  pipe  is  pierced  full  of 
small  holes  for  the  entrance  of  the  water,  and  thin 
U  surmounted  by  a  large  air  ball  made  of  thin  cop- 
per so  as  to  be  capable  of  swimming  in  water.  By 
this  contrivance,  whatever  depth  of  water  there  may 
be  in  the  reservoir,  one  half  of  the  air  ball  is  always 
out  of  the  water,  as  shown  in  the  drawing",  for 
the  flexible  tube  allows  it  to  rise  or  fall  with  the 
water,  and  consequently  the  perforated  end  of  the 
copper  pipe  at  which  the  water  enters  is  never  more 
than  an  inch  or  two  beneath  the  surface,  bo  that 
none  but  the  very  purest  portion  of  water  within  the 
reservoir  can  ever  be  drawn  off  for  use. 

It  appears  to  me,  thai  this  is  a  very  simple  and 
effectual  contrivance  for  obtaining  good  water;  and 
the  improvements  which  have  obviously  appeared  in 

"  Sec  the  Plate  prefixed  to  this  Gmay,  fig.  4. 


398  0N   WATER. 

several  of  the  processes  of  this  establishment  justiff 
my  recommpendatioh  of  the  scheme,  and  induce  me^ 
to  say  that  it  is  my  decided  opinion  that  a  Bimfltf 
one  should  be  adopted  not  only  at  other  workit  ift 
Scotland,  but  throughout  the  British  dominions  Vf 
all  those  bleachers  or  printers  whose  situations  Irilt- 
adihit  of  it. 

Dr.  Campbell,  when  treating  of  the  waters  of 
Great  Britain,  makes  an  observation  much  to  oiir 
purpose :  '* Nature,**  says  he,  '4s  said  to  be  BfrioitAer* 
to  some  people  and  a  step-dame  to  others ;  but  the 
real  truth  is,  that  Providence  is  kind  alike  to  alV 
and  it  is  industry  only  that  makes  a  difference  be^ 
tween  nations ;  for  those  who  contemplate  her  gifts/ 
and  study  how  to  make  use  of  them,  very  rari^ 
fail  of  finding  their  pains  rewarded,  even  txyototf 
their  expectations*'.** 

But  to  return  to  our  subject.  The  necessity  therij 
is  of  pure  water  for  the  use  of  the  bleacher  has  be^n 
fully  explained  in  the  foregoing  Essay ;  but  to  the 
printer  of  fine  calicoes  it  is,  perhaps,  of  still  greater 
importance.  Such  water  must  be  used  in  every  pro*^ 
cess  from  the  first  to  the  last  for  the  light  coloured 
prints ;  for  a  single  operation  either  of  dunging^' 
washing  or  dyeing  such  pieces  in  common  waters- 
would  spoil  the  delicacy  of  the  grounds,  and  d^ 
cidedly  impair  the  beauty  of  the  goods. 

Bleachers  are  not  always  aware  of  the  loss  they 
sustain,  in  the  extra  consumption  of  potash,  by  the 

^7  Polkkal  Survey  (^Britain,  quarto^  vol.  i.  p.  109. 


ON   WATER.  399 

use  of  hard  water ;  nor  are  they  apprised  that  the 
saline  substances  which  render  the  water  hard,  must 
either  be  all  neutralized  or  decomposed  at  tlie  ex- 
pense of  the  alkali,  before  such  water  can  be  ren? 
dered  efficient  in  any  of  their  processes.  A  table 
of  the  comparative  power  of  various  substances  with 
r^;ard  to  softening  and  hardening  of  water,  will  be 
Sound  in  the  work  of  Dr.  Home  already  quoted, 
page  249.  Likewise  several  curious  experiments  on 
the  effects  of  different  waters  in  sundry  culinary 
operations,  pages  288 — 298. 

Brewers  of  malt-liquors  labour  under  as  great  an 
inconvenience  from  the  use  of  hard  water;  for  it  is 
well  known  that  the  largest  portion  of  extractive 
matter  cannot  be  drawn  or  separated  from  the 
vegetable  substance  by  means  of  such  water.  The 
annual  profit  of  a  brewer  must  therefore  in  a  great 
measure  depend  upon  the  purity  of  the  water  he 
emplojrs,  as  well  as  on  the  goodness  of  his  malt^. 

To  the  grower  of  flax  for  the  operation  of  steep- 
ing, soft  water  is  of  the  utmost  consequence.  In 
such  water  the  process  usually  goes  on  with  regu- 
larity and  safety^  whereas  in  water  that  has  a  con* 
siderable  degree  of  hardness,  the  flax  may  lie  month 
after  month  until  its  texture  be  injured,  and  still 
the  ligneous  matter  will  not  be  properly  separated. 
The  intention  of  steeping  is  to  loosen  the  harl  or 
bark  of  the  flax  from  the  bun  or  woody  part  of  the 


*•  See  the  Letters  on  Brewing,  in  the  Essaj/s  of  the  Dublin 
Society,  octavo^  London,  1740,  page  203. 


400  ON  WATKR. 

plant;  and  this  is  accomplished  by  a:  solution.  oC-Ae 
mocikigtnous  substaooe  which  occasions  them  la 
cohere*  Putrefiaction  bang  the.  meana  emfdoyed 
to  attain  that  end>  hard  water  niu«t  be  impropervfbr 
steeping,  because  all  such  waters  have  the  piopei^ 
of  resisting  the  putrefisctive  process.  Dr.  Hmcm^ 
who  made  many  experiments  on  this  paiticolar 
brandi  of  our  subject  ^y  assures  us  that  flas  vamy  lie 
even  four  or  five  months  in  moss^water  beSoR  it 
will  be  sufficiently  steeped.  Hence  he  recommendi 
''that  the  steeping  should  be  made  a  bosiiiess  dir 
stinct  from  .the  raising  of  flaai)**  and  says  that  in 
Holland  it  is  managed  by  lint-dressers»  who  boy  the 
ilax  standing  on  the  ground,  and  carry  it  to  thrir 
own  premises  to  steep.  He  has  sdso  remarked  AiKt 
the  flax,  when  properly  watered,  acquires  a  sli{ipefy 
oiliness  on  its  skin,  owing  to  a  solution  of  the  toii^ 
cilage ;  but  Pliny*s  rule  is  still  the  most  otttun, 
•*  Maeeratos  indicio  esi  membranm  ItMpaihr  *.•* 
-  Should  these  cursory  observations  be  the  means 
of  exciting  a  wish  in  any  of  our  agriculturists  tb 
pursue  the  investigation  of  this  subject,  I  would  re- 
commend to  their  perusal  a  series  of  letters  on  tbto 
management  of  flax,  published  in  the  Essays  of  the 
Dublin  Society,  already  quoted ;  and  as  this  book  is 
not  commonly  to  be  met  with,  I  shall  transenbe  a 
passage  or  two  in  confirmation  of  the  foregoing  as- 
sertions. 

**  Two  parts  in  three  of  those  who  deal  in  flax,** 

*•  See  his  Treatise  <m  Bleaching,  page  318- 
«>  Plinii  Hist,  Nat.  lib.  xix. 


ON   WATER.  '^l 

MKjfB  the  writer  of  these  letters^  'f  seem  to  think  that 

^  eveiy  kind.of  water  is  equally  good :  but  this  is 

^*  certainly  a  considerable  mistake,  and  has  done 

^  more  injury  to.  the  linens  of  this  kingdom  than 

^  our  people  are  aware  of.  :  Notwithstanding  the 

**  best. endeavours  of  our  bleachers,  our  linens  are 

^  greatly  inferior  to  those  of  the  Dutch  in  colour, 

'^  and  I  know  no  more  likely  cause  for  it  than  the 

'f* Impurity  of  the  water  employed.     The  clearest, 

^  ttiUest,  sq/iesi  water  is  the  best  *^** 

.     ¥>Hence  the  necessity  of  having  settled  flax- 

^  dressers  resident  in  convenient  habitations,  and 

'^'disposed  in  various  places  about  the  countiy.  Our 

-f^J^erant  undertakers  .take  the  water  as.Uiey  find 

'**  it,  good  or  bad,  as  the  place  where  they  are  em- 

.^  ployed  affords  it :  therefore,  let  their  skill  be 

**  otherwise  what  it  will,  this  single  circumstance 

**  must  defeat  their  best  endeavours.** 

f  The  most  eligible  situation  for  the  flax-dresser 
is.  in  the  neighbourhood  of  a  large  lough,  or  a 
'^  still  river,  where  there  is  a  convenient  spot  for 
'*  laying  out  his  ponds  and  reservoirs.  The  dresser 
*^  who  would  perfectly  succeed  must  have  ponds  of 
^  difierent  kinds,  for  a  small  pond  is  less  liable  to  / 

*^  disturbance  from  winds  than  a  large  lake.  *Tis 
-'^ |Mt)bable,  our  people  may  object  to  the  cost;  but 
^  I  beg  leave  to  refer  them  to  the  Dutch,  who  find 
**  by  experience  that  the  best  conveniencies  are  air 
•*  ways  the  cheapest." 

»>  Letter  by  R.  M.  No.  31,  dated  Nov.  8th  1737,  in  the 
DMm  Eisays^pt^c  \3\, 

VOIf.  II.  2  D 


9€ 
€9 


402  oif  wAxfiH. 

*^  As  a  situation  fevourable  in  every  drcumstance 
^'  cannot  ahvays  be  ol»tuned,  the  flax*dresser  nu^ 
'*  ttt  down  with  safety  in  any  place  where  there  b 
**  abundance  of  water^  and  room  for  resenrmn» 
^  though  the  watet  should  not  prove  of  the  best 
"  and  softest  kind,  spring  waters  exoqited»  wfaidi 
^*  obstinately  retun  their  harshness.  Any  stream 
sufficient  to  supply  him,  may  mth  proper  care  be 
^  made  serviceable  to  his  purpose.  Admittan^  it 
into  his  ponds  betimes^  and  allowing  it  a  Umgat 
season  to  deposit,  and  receive  the  influence  of  the 
sun  and  air,  will  make  incU£ferent  water  equal  to 
^e  best.  Where  he  has  capadous  ponds,  'tis  the 
dresser's  fault  if  he  has  not  good  water.  Who- 
ever has  such  ponds  may  always  procure  good  wa- 
ter, and  without  them  nothing  but  a  scaree  and 
lucky  situation  can  afibrd  success  "*•** 


CI 

« 
c< 
i< 
ic 
cc 
c« 

fC 


From  the  experiments  which  I  have  m3rsdf  made 
in  DYEING,  I  am  convinced  there  are  few  of  the 
dye-woods  or  other  vegetable  substances  that  are 
employed  in  that  art,  which  will  yield  their  cohiun 
freely  to  any  but  pure  water.  Dr.  Bancroft  dSioo- 
vered  that  if  logwood  be  boiled  in  distilled  water,  h 
will  give  a  yellow  decoction  ^,  whereas  we  all  know 
that  a  decoction  of  this  wood  when  made  with  com* 
mon  spring  water  is  of  a  full  red,  or  a  dark  blood- 
colour. 


M  See  Essays  of  the  Dubim  Society^  Letter  32d^  page  1S5. 
^'  Bancroft's  PkHosophf  <^ permanent  Colimrs,  vai/u.  p.  341. 


ON    WATER.  403 

By  the  experiments  of  Dr.  Percival  It  has  been 
ascertained,  that  soft  water  acts  more  powerfully  as 
a  menstruum  on  vegetable  bitters  and  astringents 
than  hard  pump  water,  and  that  it  dissolves  some 
resinous  bodies  without  any  medium,  or  at  least 
with  a  much  smaller  proportion  of  mucilage  than  is 
commonly  employed  ". 

The  baneful  effects  of  impure  water  on  the  hu- 
man constitution  have  been  already  noticed  in  a  for- 
mer part  of  this  Essay  ";  and  I  am  now  desirous 
of  impressing  upon  my  readers  the  importance  of 
their  examining  the  nature  of  the  water  they  drink, 
and  of  advising  them,  should  it  be  impure,  to  adopt 
some  of  the  means  already  recommended  for  ob- 
taining it  in  a  slate  of  greater  perfection.  Hero- 
dotus relates,  that  in  Ethiopia  the  inhabitants  live 
to  be  an  hundred  and  twenty  years  old  ;  that  they 
eat  animal  food  and  drink  the  water  of  their  own 
country,  which  is  so  light  that  wood  will  not  swim 
upon  it,  and  that  it  is  the  use  of  this  water  that  pro- 
longs their  lives  ^.  Dr.  Percivnl  says  that  the  Spa- 
niards are  entirely  exempt  from  many  of  our  cuta- 
neous diseases ;  and  the  reason  he  assigns  for  this 
remarkable  fact  is,  that  the  air  of  Spain  is  clear  and 


"   EiperimcnltandOlneTmtioni  on  Ibe  Pump  JValer  of  Man- 
Chester,  by  Dr.  Percival,  octavo,  London  1769. 
"  See  page  388. 
*"  HcTodotin,  lib.  iii.  cap.  125. 

•iDi 


404  ON   WATER. 

sciehe,  and  the  water  they  drink  pure  and  whole- 
some**. 

In  the  water  of  the  Pei-ho  river  in  China,  tihe 
mud  is  suspended  in  such  large  quantities  as  to  ren- 
der it  scarcely  potable.  This  water  is,  howevjBri 
quickly  refined  for  use  by  the  following  simple  pro- 
cess. A  small  lump  of  alum  is  put  into  the  h<d- 
low  joint  of  a  bamboo,  which  is  perforated  unth  s^ 
vera!  holes.  The  water  taken  from  the  river  is  stir- 
red about  with  this  bamboo  for  three  or  four  mi- 
nutes, during  which  the  earthy  particles  umtiqg 
with  the  alum  are  precipitated  to  the  bottom,  leav- 
ing the  water  above  them  pure  and  dear.  Persons 
of  rank  in  China  are  so  careful  about  the  quali^  of 
the  water  intended  for  thdr  own  consumplioby  that 
they  seldom  drink  any  but  what  has  been  distilled  "• 

Not  only  the  Chinese  are  careful  bbout  the  qua- 
lity of  the  water  they  drink,  but  from  the  most  au- 
thentic information  it  appears,  that  the  inhabitants 
of  some  parts  of  the  East  Indies  have  always  bera 
aware  of  the  importance  of  drinking  the  very  purest 
water.  Mr.  Harmer  relates,  that  the  Hindoos  go 
sometimes  to  great  distances  to  fetch  water,  and 
then  they  boil  it  that  it  may  not  be  hurtful  to  tra- 
vellers :  after  this,  they  stand  from  morning  until 
night  in  some  great  road  where  there  is  neither  pit 

nor  rivulet,  and  offer  it,  in  honour  of  their  gods^  to 

■  —  -*"  — 

^  Percival's  Observatioru  on  the  Waters  of  Manche$ter. 

"  Macariney*s  EmboMtw  to  China,  bv  Sir  George  Staunton, 
Bart.  2  vols,  quarto,  London^  1797,  vol.  ii.  page  68. 


be  drunk  by  the  passengers  *•.  It  was  to  tliis  hu- 
nune  custom  that  an  eminent  teacher  probably  re- 
ferred, when  he  told  his  adherents  that  if  they  gave 
a  cup  of  cold  water  in  /tis  name,  thev  should  hot 
lose  their  reward. 


A  short  time  ago  a  very  neat  and  convenient  ap- 
paratus in  glass,  for  filtrating  small  quantities  of 
water  or  other  fluids,  was  contrived  by  Mr.  William 
Haseldine  Pepys,  and  has  been  sold  in  considerable 
numbers  by  Messrs.  Knights,  in  Foster  lane, 
Cheapside.  Tbis  instrument,  I  conceive,  must  be 
useful  for  many  purposes  besides  that  of  purifying 
water,  and  therefore  I  have  obtained  leave  to  make 
a  drawing  of  it  to  accompany  this  Essay  *°. 

The  method  of  purifying  water  recommended  by 
Professor  Parrot  of  Paris,  and  which  consists  in 
passing  it  through  sand  or  charcoal  placed  within  a 
targe  inverted  syphon,  appears  to  promise  a  success- 
ful result.  It  will  be  found  under  the  article  "  Fil- 
traUon"  in  Dr.  Willich's  Do?iieslic  Encyclopedia, 
vol.  ii.  page  276.  Several  excellent  modes  of  raising 
water  are  also  well  described  in  the  same  work,  un- 
der the  article  "  Water,"  in  vol,  iv.  page  292. 

It  was  formerly  a  general  complaint  that  the 
health  of  maritime  people  was  much  injured  by  the 
internal  use  of  water  which  had  become  in  some 
degree  putrid  by  age,  or  in  other  words  by  being 

"  See  the  JMiatic  MixeeUang,  CoIcutU  edit.  1786,  vol,  ii. 
p.  M2. 
""Seethe  Plate  prefixed  to  thbi  Bway,  fig.  i.  U.  and  ii». 


406  ON   WATER. 


kept  stagnant  for  so  long  a  period  as  is'soinetuiMi 
necessary  on  long  voyages.  In  modem  tiniei»  horn 
ever,  various  expedients  hare  been  contrived  to  ok 
viote  this  great  inconvenience.  Dr.  Stephen  Hdai 
discovered  that  good  wholesome  water  may  be  piQr 
cured  on  a  voyage  by  the  distillation  of  sea  watOTf 
if  |lb.  of  chalk  be  previously  mixed  with  every  gal* 
Ion  of  water  put  into  the  still.  A  remarki^le  d^ 
cumstance  respecting  the  obtaining  of  firesh  water 
at  sea  by  those  who  may  be  so  unfortunate  ntfi 
have  their  ship  frozen  up  in  the  ice  all  winter*  k 
related  by  Mr.  Boyle.  '<An  old  sea  ciqptain,**  he 
says,  *^  assured  him,  that  when  his  ship  wius  iift- 
mured  with  ice  in  the  frigid  zone,  so  that  they  cpnU 
not  in  a  long  time  get  so  much  as  a  barrel  of  ni^ 
water,  he  made  weUs  of  the  thick  pieces  of  ie^  to 
receive  the  liquor  of  the  thawed  ice,  and  found  tbp 
water  (though  on  the  main  sea)  to  be  good  £rei^ 
water  fit  for  drinking,  for  dressing  thdr  meat,  and 
other  uses,  and  that  he  never  feared  the  want  of 
fresh  water  in  those  seas  ^^*' 

I  am  happy  to  embrace  this  opportunity  of  sug- 
gesting to  those  who  may  have  to  supply  large  vt^ 
sels  with  stores,  that  it  b  always  advisable  to  make 
choice  of  hard  water  for  the  use  of  the  ship's  cnew, 
as  this  resists  putrefoeUon,  and  consequently  wiU 
keep  good  much  longer  than  sq/i  water.  The  la- 
convenience  of  having  none  but  hard  water  to  use 


«i  Boyle's  Observations  on  Cold,  London  1683^  Appendixt 
p.  15. 


ON    WATER.  407 

for  the  different  culinary  and  domestic  purposes, 
and  the  danger  resulting  from  the  continued  drink' 
ing  of  such  water,  can  be  easily  obviated  by  the  use 
of  an  alkali,  which  might  be  employed  occasionally 
to  precipitate  the  impurities,  and  on  such  quantities 
only  as  would  be  required  for  the  wants  of  those  on 
board,  as  before  directed  at  page  390. 

Such  ships  as  are  fitted  out  from  the  port  of  Lon* 
don  usually  take  in  their  supply  of  water  from  the 
Thames,  as  this  water  is  said  to  possess  propertien 
whidi  render  it  peculiarly  fit  for  sustaining  a  long 
sea-voyage.  At  first,  after  being  kept  for  some  time, 
it  turns  in  some  degree  putrid  and  offensive,  pro- 
bably from  some  kind  of  fermentation  ;  after  which 
it  again  becomes  pure  and  palatable,  so  as  to  serve 
better  than  ali  others  for  sea-stock.  Although  the 
question  is  of  great  consequence,  1  have  never  yet 
heard  any  rational  explanation  of  this  phenomenon. 
"  Water  taken  from  the  New  River  in  London,  says 
a  writer  in  the  Philosophical  Transactions,  stank 
very  much  after  being  kept  stagnant  tor  eight  days, 
but  when  it  arrived  at  Virginia  it  again  became 
sweet**,"  The  water  of  the  Rhone,  if  it  be  suffered 
to  stand  for  the  impurities  to  subside,  and  then  be 
put  into  earthen  vessels,  will  not  putrefy  by  heat, 
though  it  will  soon  become  fetid  if  put  into  wooden 


408  OK  WATER. 

"Dr.  Priestley^  in  his  Observations  on  Air,  rehto^ 
on  the  testimony  of  Mr.  Garrick»  that  the  ffew^ 
voirs  for  water  in  the  town  of  Harwich  are  generally 
very  foul  on  their  sides  and  at  the  bottom ;  and  tfasit 
provided  these  are  not  cleansed  of  what  adheres  to 
them,  they  always  preserve  the  water  sweet,  otber* 
mse  it  will  become  fetid  and  unfit  for  use,  and  tU 
vessel  will  not  recover  its  sweetness  till  the  ^Mn 
and  bottom  grow  very  foul  again.  Dr.  Priestfey 
supposes^  that  what  they  call  impurities  is  menify 
vegetating  matter  that  adheres  to  the  Mdes  of  tbs 
vessel,  and  imbibes  every  thing  tending  to  putie^ 
fection  ^.  May  not  the  change  which  is  effected  ia 
the  Thames  water  be  attributed  to  a  similar  eause  ? 
A  curious  feet  has  indeed  been  recorded  by^Dr. 
Boerhaave  respecting  the  preservation  of  water  ia:a 
wholesome  state  under  the  equator  and  between  the 
tropics,  where  stagnant  waters  always  breed .  an  ia- 
numerable  quantity  of  insects,  and  soon  becotine 
extremely  putrid.  Water,  he  says,  which  has  thai 
spontaneously  grown  offensive,  may  be  easily  rettf 
dered  wholesome  again,  and  this  merely  by  occa- 
sioning  it  to  boil  for  a  moment ;  for  this  operatioD 
will  destroy  the  animalcula,  which,  with  the  rest  of 
the  impurities,  will  subside,  and  then  the  addilaon 
of  a  very  small  quantity  of  any  strong  acid,  partioo- 
larly  the  sulphuric,  will  render  it  fit  for  use..  Or  if 
a  small  portion  of  sulphuric  acid  be  put  to  the  wa- 


^  Observations  on  Air,  vol.  ii.  page  185. 


OK  WATER.  400 

ter  at  the  first,  this  will  preserve  it  from  animateula 
or  from  putrefying  ^. 

-  I  ronst  not  however  suffer  this  part  of  the  sub- 
jaJBt  to  pass  over  without  inserting  a  caution  re- 
cpecting  the  use  of  leaden  reservoirs  and  pumps  of 
lead,' for  the  preservation  and  conveyance  of  water 
designed  for  drinking,  because  I  have  reason  to  be- 
iSeve  that  this  practice  has  been  attended  with  many 
^my  fatal  consequences. 

The  poisonous  nature  of  lead  when  taken  into 
the  stomach  in  a  state  of  solution  is  now  pretty  ge- 
aerally  known ;  but  as  lead  when  immersed  in  water 
18  not  soluble  in  that  fluid,  persons  are  apt  to  ima- 
gine that  ho  noxious  effects  can  arise  from  the  use 
tyf'Ieaden  pipes  and  cisterns.  But,  though  pure  wa- 
ter of  itself  will  neither  dissolve,  nor  oxidize  this 
metal,  yet  the  oxygen  of  the  atmosphere  combined 
with  the  action  of  the  water  will  convert  it  to  an 
cadde^  when  it  absorbs  carbonic  acid  gas  with  avi- 
dity firom  the  air,  and  this  renders  it  capable  of  so- 
hition.  The  oxides  of  lead  are  insoluble  in  water, 
but  a  small  portion  of  any  acid,  even  one  of  the 
weakest  kind  (carbonic  acid),  will  render  them  so- 
Ibble.  So  small  a  portion  as  16  parts  of  carbonic 
acid  is  sufficient  to  acidify  83  parts  of  oxide  of 
lead,  the  whole  of  which  then  becomes  soluble  in 
water,  impregnated  with  carbonic  acid. 

The  white  line  which  may  be  seen  at  the  surface 
of  the  water  in  leaden  cisterns,  is  occasioned  by  the 


^  Dallowe*8  Trantlatitm  of  Boerhaave,  vol.  i.  page  348. 


410  OM  WATBR. 

oxidizement  of  the  metal ;  and  a$  diis  oxidfl  abwifal 
the  carbonic  acid  of  the  atmoaphore,  the  aside  nf 
lead  becomea  converted  to  carbonate  of  lead*  and 
18  taken  into  the  stomach  of  those  who  drink  iIk 
water  which  has  been  standing  in  such  reoqitoeiea. 
Dr.  Percival^  Dr.  Johnstone,  Sr'6«  Baker,  Dr* 
liunbe,  and  other  physidans,  have  related  many 
deplorable  instances  of  individuals  and  even  nMe 
ftunilies  being  taken  off  by  this  inudious  poison.  I 
have  myself  reason  to  believe  that  some  yeaif  ago 
I  lost  an  amiable  and  highly  valued  relative  in  tUs 
way,  and  therefore  am  desirous  of  inserting  aq  -m^ 
count  of  these  fitcts,  in  the  hope  of  recalling  theat- 
tention  of  the  public  to  the  state  of  thdr  rcscrnsiw 
for  water,  and  thus  being  the  humble  means  ^  pMfe^ 
longing,  if  not  of  saving,  the  lives  of  many  indivir 
duals. 

It  is  necessary,  however,  to  offer  a  few  remarks 
on  some  of  the  properties  peculiar  to  water,  and  OD 
the  various  applications  of  this  important  fluid.  Tkf 
more  obvious  properties  of  water  have  been  man- 
tioned  in  the  early  part  of  this  paper,  but  there  aia 
several  others  to  which  it  is  also  necessary  to  b^ 
vert. 

The  different  appearances  and  forms  which  water 
is  capable  of  assuming  have  already  been  slightly 
noticed.  Some  further  particulars  however,  de- 
serve our  attention. — In  the  state  of  elastic  vapour 
it  is  perfectly  transparent,  or  invisible  to  the  eye. 
In  this  condition  it  is  completely  soluble  in  atmo- 


ON  WATEtt.  41  i 

spheric  air;  and  though  it  may  by  increase  of  tem- 
perature be  attenuated  in  so  remarkable  a  degree, 
yet  caloric,  or  the  matter  of  heat  necessary  to  con- 
vert it  into  vapour,  is  incapable  of  occasioning  any 
permanent  change  or  alteration  in  the  chemical  na- 
ture of  this  fluid. 

Atmospheric  air  and  water  act  reciprocally  on 
each  other.  The  former  dissolves  aqueous  vapour, 
and  water  dissolves  or  absorbs  atmospheric  air.  In 
its  natural  state,  water  is  generally  esteemed  to  be 
850  times  heavier  than  atmospheric  air ;  but  waters 
differ  a  little  in  their  specific  gravity.  I  found  that 
a  bottle  which  would  hold  only  42.58  grains  of  di- 
stilled water  at  the  temperature  of  60°  would  contain 
4200  grains  of  New  River  water,  or  4262  grains  of 
pump  water  such  as  rises  in  Goswell  Street,  London. 

Christopher  Clavius,  the  eminent  German  ma- 
thematician, poured  some  water  into  a  bolt-head, 
and  then  seated  the  mouth  of  its  neck  hermetically, 
and  marked  with  a  diamond  the  place  to  which  the 
water  rose  ul  that  time :  he  then  hung  it  up,  and 
eighty  years  afterwards  it  was  found  in  Kircher's 
etudy,  just  as  full  as  it  was  at  first ". 

The  great  fluidity  of  water  is  one  of  its  most 
remarkable  properties".  It  is  this  which  renders 
it  80  useful  in  many  of  the  mechanical  arts,  some 


*  Dallowe'a  Kdltion  of  Boerhaate,  vol.  i.  j»gc  326. 
■"  This  property  hatii  furnished  ShaVeKpeftre  with  one  of  his 
bcMitiful  similes ; 

"  Men's ciil  manners  live  in  brass,  Ihcir  virtues 
We  write  in  water." 


412  ON  WATER. 

of  which  I  shall  particularize  hereafter ;  and  it  if 
owing  to  this  that  it  has  always  a  tendency  to  find 
its  own  level.  Hence  it  has  for  many,  ages  been 
employed  to  determine  the  plane  of  the  bttim^ 
and  for  other  philosophical  purposes.  The  aobent 
power  of  water  is  increased  by  removing  the  atmo- 
spheric pressure  from  its  surfece. 

The  experiment  mth  the  solution  of  sulphate  «f 
soda,  related  at  page.  363  of  this  Essay,  though 
introduced  for  another  purpose,  is  sufficient,  to  provf 
this  fact  also ;  for  the  water  holds  all  the  s^  jn 
solution,  no  longer  than  the  bottle  is.  closely  ooikr 
ed;  and  as  soon  as  the  action  of  the  atmosphere  19 
restored,  part  of  the  salt  precipitates  in  a  crystal 
line  form.  Hence,  I  conceive  it  to  be  extremdj 
desirable  to  try  whether  some  important  eflEects  in 
ihe  art  of  dyeuig,  or  rather  in  the  prooeqsM  ^ 
extracting  the  colouring  matter  of  vegetable  sulfr 
stances,  by  means  of  water,  might  not  be  produced 
by  conducting  those  operations  in  a  partial  vacuunu 

Another  circumstance  respecting  water  is,  that 
its  specific  gravity  is  le^ened,  except  in  particular 
cases,  by  increase  of, temperature.  This  fluid  might 
consequently  be  expected  to  increase  in  its  specific 
gravity  in  exact  ratio  with .  its  reduction  of  tempe> 
rature ;  and  this  is  found  by  experiment  to  bq  ac- 
tually the  case,  till  it  be  reduced  to  42^  of  Fahren- 
heit ;  but  after  that  it  becomes  specifically  lighter 
by  every  further  abstraction  of  caloric,  and  ftimishes 
a  memorable  instance  of  one  of  those  deviaUons 
from  the  usual  course  of  nature  which  its  omni- 


ON   WATER.  4IJ 

sclent  and  beneficent  Author  h&a  appointed  for  the 
preservation  of  the  world,  and  the  welfare  and  feli- 
city of  its  inhabitants.  I  need  not,  however,  par- 
ticularize, because  the  fact  has  already  been  suffi- 
ciently explained  in  the  first  volume  of  these  Essays*". 

In  a  variety  of  ciiemical  operations  it  is  import- 
ant to  know  the  specific  gravity  of  the  water  em- 
ployed. A  Table  of  its  specific  gravity  from  30°  to 
80°  Fahrenheit  will  be  found  in  the  84th  vol.  of  the 
Philosophical  Transactions,  and  also  in  the  1st  vol. 
of  Mr.  Biande's  Manual,  where  it  is  accompanied 
by  an  example  of  its  use  in  reducing  the  weight  or 
bulk  of  water  employed  in  any  case,  to  that  which  it 
would  have  at  any  other  common  temperature.  The 
solvent  power  of  water  is  generally  influenced  by  its 
specific  gravity. 

Having,  in  the  foregoing  paragraph,  adverted  to 
the  solvent  power  of  water,  that  circumstance  has 
reminded  me  of  a  table  of  the  solution  of  salts 
which  I  constructed  some  time  ago  for  my  own  use. 
This  table  has  been  extremely  serviceable  in  my 
own  laboratory :  I  shall  therefore  insert  it,  in  the 
hope  that  it  may  be  of  some  use  to  many  of  those 
persons  who  may  take  the  trouble  of  perusing  these 
volumes.  I  cannot  vouch  for  its  perfect  accuracy 
in  every  instance,  as  some  of  the  experiments  are 
dtfHcult  to  accomplish;  but  I  believe  it  will  be  found 
to  be  sufficiently  correct  for  every  purpose  of  real 
business. 


'  See  EMny  I!,  vol.  i.  puges  58— G2. 


4 14 


OH  WATER. 


A  New  TUile  of  die  Qmatity  of  Water  required  to 
dissolve  100  Pounds  of  each  of  the  MIowing  Silts. 


Sdto. 


Sul{4uUe  of  Magnesia,  100  lbs. 
'  Ammonia    .    .    . 

Potash    .    .    .    . 

super   .    . 


Soda 

Alumina  and  Potash  • 


Nitrate  of  Lime 
■  ■  Magnesia 

Ammonia 

■  Soda  .     . 

^  Potash    . 

— ——  Strontites 

Barytes  . 


Muriate  of  Lime 
Strontites 

■  Magnesia 
Soda  .    . 

Pot»h    . 

■  Ammonia 
Barytes 


Phosphate  of  Ammonia 
Soda  .     . 


Oxy-muriate  or  Chlorate  of  Potash 

Borax 

Carbonate  (sub)  Ammon.      .    . 

super,  ditto      .     .     . 

— —  sub.  Soda    .... 
super,  ditto      .    .    . 

sub.  Potash      .    .    . 

■     super,  ditto      .    .    . 


At  OOP. 


100 
200 

1670 
200 
500 

2000 
25 
100 
200 
300 
720 
500 

1120 
50 
84 
100 
286 
300 
340 
560 
400 
400 

2000 

1180 
200 

200 


400 


BoQiBf; 


75 
190 
500 
100 
224 
133 

20 

60 

100 

50 

335 


280  1 

100 

180 
200 
304 
590 
100 

100 


125 


■  V- 


The  ancients  seem  to  have  had  very  confused 
notions  of  the  changes  which  are  produced  in  the 
specific  gravity  of  water  by  variation  of  temperature. 
All  the  information  that  Piiny  gives  on  the  subject 


ON  WATER. 


41£ 


19  comprised  iii  a  single  sentence,  and  even  this  is 
calculated  to  convey  an  erroneous  idea.  "All 
water,"  says  he,  "grows  to  be  heavier,  after  that 
mid-winter  is  once  passed*'." 

It  appears,  however,  that  the  contraction  and 
expansion  of  water  by  change  of  temperature  were 
well  known  to  the  early  chemists.  Bacon  and 
Boyle'"  have  both  written  expressly  on  the  subject; 
but  I  know  of  no  author  (except  Sir  Charles  Blag- 
den  and  Mr.  John  Dalton)  who  has  made  any  direct 
experiments  to  determine  what  kind  of  ratio  is  ob- 
served by  this  Buid,  in  its  variation  of  bulk  by  the 
addition  or  abstraction  of  caloric.  A  Table  com- 
piled by  the  former  of  these  philosophers  will  be 
found  at  the  latter  end  of  Chapter  3.  of  The  Che- 
mical Catechism,  1 0th  edition,  page  76,  and  that 
by  Mr.  Dalton  I  now  copy  from  his  own  work". 

A  Table  of  the  force  of  the  vapour  from  water, 
in  every  temperature  from  that  of  the  congelation 
of  mercury,  or  40'  below  zero  of  Fahrenheit,  to 
325*  of  that  thermometer,  is  given  in  Rees's  Cyclo- 
pedia ''*■  Some  important  observations  on  the  use 
of  steam  in  the  processes  of  decoction,  solution, 
diiitillation,  &c.,  will  be  found  in  the  Appendix  in 
an  Additional  Note  to  the  Essay  on  Water. 


^  Holland's  Plimf,  book  xxxi.  chap.  5, 

™  £jcp«riniefi<al  Hiilory  of  Cold,  by  the  Honourable  Robert 
Boyle  i  quarto,  London  1683,  paged  92  and  1 13. 

"  See  Dalion's  New  Sytlem  of  Chemical  Plulotophy,  Part  I. 
page  29. 

"  See  Cyclopedia,  vol.  xxxiv.  signature  D,  page  6. 


416 


ON   WATER. 


Mr.  Dalton-s  IWle  of' 1fa6  Expanitoh  of  Water 
by  Change  of  Tempemture. '      . 


Temper»- 

• 

TtBxptn- 

ture  accor. 
to  Fahran^ 

Ezp^pnon. 

tore  socor. 
to  Fahion- 

Expansion. 

belt. 

heit. 

120 

100236 

122« 

101116 

22 

100090 

132 

101367 

32 

100022 

142 

101638 

42 

100000 

152 

101934 

52 

100021 

162 

102245 

62 

100083 

172 

102575 

72 

100180 

182 

102916 

82 

100312 

192 

103265 

92 

100477 

202 

103634 

102 

100672 

212 

104012 

112 

100880 

I  have  no  doubt  that  the  foregoing  Table  yerj 
accurately  shows  the  variations  of  bulk  in  a  deter- 
minate quantity  of  water ;  but  it  having  occurred 
to  me  that  one  formed  in  a  different  manner  might 
possibly  be  more  useful  to  our  manufacturers  and 
other  practical  men,  I  undertook,  some  time  ago, 
a  series  of  experiments  for  that  purpose,  and  the 
following  Table  was  the  result.  The  specific  gn- 
vity-bottle  and  scales  which  were  chosen  on  this 
occasion,  are  described  in  Vol.  I.  page  501,  lAid 
are  the  same  as  were  employed  in  making  the  Su^ 
phuric  Acid  Tables  which  are  printed  in  the7A 
Essay. 


ON  WATER. 


4J7 


A  New  Table  of  the  Expansion  and  Contraction  of 
Water  by  Change  of  Temperature.  The  Baro- 
meter at  29^  Inches. 


Temp. 

Contents  in  grains 

Temp. 

Contents  in  nains 
of  a  bottle  h^ing 

ac.  to 

of  a  bottle  holding 

ac.  to 

Fsfaren- 

4365  grains  of 

Fahren- 

4265 grains  of 

hot. 

pure  water  at  42^. 

heit. 

pure  water  at  42^. 

320 

4260 

920 

4240 

34 

«    4261 

96 

4237 

36 

4262 

100 

4234 

38 

4263 

102 

4232 

40 

4264 

108 

4228 

42 

4265 

112 

4226 

44 

4264 

120 

4220 

46 

4263 

126 

4214 

48 

4262 

134 

4208 

50 

4261 

140 

4199 

52 

4260 

146 

4191 

5G 

4259 

150 

4185 

60 

4258 

154 

4180 

64 

4257 

162 

4172 

68 

4256 

170 

4160 

70 

4255 

178 

4150 

74 

4254 

184 

4142 

80 

4252 

192 

4130 

84 

4249 

200 

4116 

88 

4245            ) 

Flattering  myself  that  this  table  may  be  of  v^ry 
euential  use  in  many  cases  of  real  business^  I  am 
deurous  of  giving  an  example  of  its  application 
before  I  pass  on  to  any  other  branch  of  the  subjec,t. 
Suppose  a  boiler,  or  other  vessel  of  capacity,  to 
kold  4260  pints,  or  532^  gallons  of  water  at  any 
temperature  on  the  range  of  Fahrenheit's  scale  be- 
tween 32  and  52  degrees,  by  looking  at  the  figures 
opposite  to  150  in  the  second  column  of  tempe- 
rature, it  will  be  seen  that  such  boiler  would  con- 


VOL.  II. 


418  ON  WATER. 

tain  only  4185  pints,  or  little  more  than  &23  gal- 
lons, if  heated  to  that  degree ;  and  op  looking  at 
the  last  line,  it  will  appear  that  such  vessd  wmild 
hold  only  4116  pints,  or  514^  gallons,  at  200^: 
therefore,  should  a  boiler  be  completely  filled  by 
532^  gallons  of  water  of  the  temperature  of  52^, 
no  less  than  18  gallons  of  it  would  flow  over  the 
sides  of  the  vessel  before  the  remainder  could  be 
heated  to  20(r.  The  maximum  of  the  densi^  of 
water  is  at  about  42^:  this  fluid  therefore  becomes 
of  less  specific  gravity,  whether  it  be  heated  above 
or  cooled  below  that  point.  This  accounts  for  the 
seeming  anomaly  in  the  table,  by  which  it  appears 
that  water  occupies  the  same  room  at  32°  at  it  does 
at  52°.'» 


There  are  some  phenomena  of  water  which 
inexplicable,  though  the  authorities  I  have  for  them 
cannot  be  disputed. 

If  water  be  thrown  into  a  crucible  of  melted  glass 
in  a  high  state  of  incandescence  in  a  glasa-house 
furnace,  the  globules  of  water  will  dance  upon  the 
surface  of  the  melted  glass  for  a  considerable  tiHM^ 
like  so  many  globules  of  mercury  upon  a  drmv^ 
head ;  but  if  a  small  quantity,  or  even  a  pint»  of 
water  were  to  be  thrown  into  such  a  crucible  befeie 
the  glass  is  completely  fused  and  while  the  sandiver 
b  upon  its  surface,  the  water  would  be  rarefied  inte 


7*  See  this  more  fully  en>lained  in  th«  Manchester , 

vol.  V.  page  374,  or  in  the  Notes  to  the  3d  chapter  of  The  Che* 
mieal  Catechism, 


OK  WATER.  419 

ateam  in  an  instant,  an  explosion  would  be  the  con** 
aequence,  and  the  furnace  would  probably  be  bldwn 
into  pieces. 

In  like  manner  does  water  sooner  evaporate  from 
a  plate  of  iron  that  is  heated  to  a  red-heat  only^ 
than  from  one  tliat  has  been  brought  to  a  welding 
heat»  or  nearly  to  the  point  of  fusion. 

Again,  in  the  manufacture  of  black  bottles  it  fre- 
quently happens,  while  the  workmen  are  engaged 
in  moulding  and  blowing  the  bottles,  that  the  me- 
tal becomes  more  cooled  than  they  could  desire,  so 
that  they  find  it  necessary  to  give  directions  to  their 
attendants  to  throw  in  more  coal  and  increase  the 
Are.  This,  however  carefully  it  may  be  done,  will 
sometimes  produce  so  much  dust  that  the  surface 
of  the  glass  becomes  covered  with  carbonaceous 
matter.  Whenever  this  occurs,  it  occasions  such 
a  motion  within  the  crucible,  that  the  metal  appears 
as  though  it  were  actually  boiling ;  and  if  it  were 
to  be  used  in  this  state,  every  bottle  would  be 
speckled  throughout  and  full  of  air  bubbles.  But  at 
it  would  be  very  inconvenient  to  wait  for  the  whole 
of  this  carbonaceous  matter  to  be  consumed  by  com« 
bastion,  and  as,  by  being  partly  mixed  with  the 
l^ats  itself,  it  might  occasion  it  to  boil  over  the 
sides  of  the  crucible,  it  was  thought  very  desirable 
to  discover  an  easy  and  immediate  remedy  for  the 
aeeident,  and  this  has  been  found  in  common 
water. 

Whenever  the  accident  occurs,  the  workman 

2e2 


420  ON   WATBR. 

throws  a  little  water'  into  each  crucible ;  and  this 
has  the  effect,  not  only  of  stilling  the  mass  imiiie>- 
diately,  but  it  renders  the  metal  as  smooth  and  ptne 
as  before.  This  curious  and  almost  instantaneoas 
effect  is  probably  owing  to  the  water  becoming  da- 
composed>  and  affording  its  oxygen  to  the  ooaU 
dust,  and  converting  it  to  carbonic  acid  gas,  wtnch 
immediately  escapes  and  is  dissipated  in  the  Umxh 
sphere. 

Nothing  now  remains  but  to  describe  some  of 
the  various  uses  to  which  water  has  been  applied 
in  different  parts  of  the  world,  a  knowledge  of  wUdi 
I  conceive  may  be  turned  to  advantage  by  soim 
classes  of  readers.  .  •  >. 

In  enumerating  the  several  purposes  to  whidi 
water  has  been  applied  in  all  ages  and  countries, 
I  shall  slightly  pass  over  the  account  of  the  murical 
instruments  of  antiquity  which  were  made  to  plqr 
various  tunes  by  means  of  the  pressure  of  water; 
and  shall  also  decline  any  lengthened  detail  of  the 
methods  which  were  formerly  adopted  by  supersd* 
tion  for  the  trial  of  supposed  delinquents,  by  the 
immersion  of  the  unhappy  individuals  in  water,  as 
these  are  matters  more  of  curiosity  than  utili^  and 
improvement. 

Andrew  Brice,  in  describing  one  of  the  palaets 
of  the  Grand  Duke  of  Florence,  says, ''  The  pilasters 
are  adorned  with  an  organ,  which  by  means  oS 
water  plays  several  tunes;**  and  in  a  note  states, 


ON   WATER.  421 

that  such  tiydraulic  organs  are  to  be  seen  in  several 
grottos  in  Italy ^*.  The  invention,  however,  is  not 
modern;  for  Cresibus  of  Alexandria,  wbo  lived  in 
the  reign  of  Ptfilemy  Euergetes,  is  said  to  have  con- 
trived them.  Archimedes  and  Vitruvius  have  left 
desciiptionfl  of  the  instrument,  and  we  find  tlie  figure 
of  one  on  the  reverse  of  a  large  medallion  of  Vb- 
lentinian. 

It  was  formerly  a  custom  in  several  countries  to 
weigh  those  that  were  suspected  of  magic,  it  being 
generally  imagined  that  sorcerers  were  specifically 
lighter  than  other  men.  This  was  the  origin  of  the 
practice  of  throwing  tlie  accused  person  into  water; 
when,  if  his  body  floated  upon  the  surface,  he  was 
convicted  of  witchcraft  and  burnt,  but  if  it  sunk  to 
the  bottom  he  was  acquitted.  M.  Ameilhon  has 
published  a  curious  paper  In  the  37th  vol.  of  the 
Memoirs  of  the  Iloyal  Academy,  on  this  particular 
subject,  in  wlueli  he  endeavours  to  sliow  the  proba- 
bility that  some  of  these  miserable  persons  did  ac- 
tually float  on  the  water.  He  states  that  among 
the  multitude  of  persons  subject  to  hysteria  and 
other  similar  complaints  there  are  several  who  can- 
not sink  in  the  water;  and  hence  he  concludes  that 
the  pretended  magicians  and  sorcerers  who  floated 
when  tried  by  the  water -or  deal ,  were  persons  deeply 
affected  with  nervous  disorders.  Pomme,  the  cele- 
brated French  physician,  in  bis  Traile  des  Affec- 
tions Vapoitreitses,  supports  the  same  opinion. 

''  Brice's  Geograpkkal  Dktiotutrj/,  folio,  London  1/59, 
vol.  i,  page  57-1. 


L 


422  ON  WATEH. 

Water  may  be  employed  as  a  mechanical  poller 
in  some  of  our  large  manu£BCturiDg  concerns  with 
great  advantage.  In  the  448th  Number  of  the  Phi* 
losophical  Transactions,  page  231,  there  is  a  de^ 
scription  of  a  very  ii^enious  water-bellows,  invent* 
ed  by  Mr.  Triewald,  for  the  use  of  iron  feigcs  and 
other  furnaces,  where  a  great  heat  is  to  be  produced 
by  forcing  a  large  quantity  of  atmospheric  air  lafeo 
the  fire-place.  Since  the  publication  of  that  account, 
water-bellows  upon  diflerent  constructions  have  been 
employed  in  various  parts  of  this  kingdom,  for  die 
business  already  mentioned,  and  also  by  those 
makers  of  utensils  in  iron  called  iron-founders; 
bwt  the  power  which  may  be  thus  given  by  wateria 
so  great,  and  the  principle  is  in  itself  so  siBii|de^ 
that  I  cannot  help  wishing  it  were  more  univeiMdl]^ 
known ;  for  I  am  confident  that  it  might  be  brai^t 
into  greater  practice,  and  extended  to  a  multipKcky 
of  aits  and  manufactures  to  which  it  has  not  yet 
been  applied.  It  is  not  possible,  however,  to  give 
the  reader  an  accurate  idea  of  this  curious  mechar 
nical  contrivance  without  a  drawing ;  I  must  there^ 
foffe  refer  him  to  the  copper-plate  engraving  whidi 
accompanies  the  account  of  it  jn  the  number  of  die 
Philosophical  Transactions  above  mentioned  ^\ 

Bellows  moved  by  water  have  been  long  in  use  at 
the  iron  forges  in  Sweden ;  and  water-bellows  on  a 


^*  A  pbii€  of  this  machine^  acoMnpaiued  br  a  descriplieii  «f 
ita.  several  parts,  may  also  be  seen  in  the  10th  volume  of  Badr 
(Uun*s  Mem/Qtrt  of  the  Royal  Society j,  octavo^  London  1741, 
page  396. 


ON    WATER.  4ZO 

dWerfrnt  construction,  and  which  are  employed  at  Ti' 
voUin  Italy.are  described  in  one  of  the  early  volume* 
ofthe  Philosophical  Transactions;  but  those  by  Mr. 
Triewatd  are  more  simple  and  on  a  better  principle. 

In  some  particular  situations,  water  is  very  pro- 
fitably employed  in  drawing  coals  and  other  niine- 
Tftla  from  the  bowels  of  the  earth.  Thirty  years 
ago  I  recollect  having  been  much  gratified  in  view- 
ing an  apparatus  of  this  kind  which  was  then  at 
work  in  the  coal  district  of  Derbyshire,  I  think 
somewhere  near  Ham ;  it  may  be  thus  described : 

Two  wooden  vessels,  or  buckets  hooped  with 
iron,  are  fastened  one  at  each  end  of  a  very  thick 
hempen  rope,  and  this  rope  is  made  to  pass  over  a 
large  wheel  which  is  fixed  exactly  per)(en(licular  to 
the  mouth  of  the  shaft  of  the  mine.  In  the  com- 
mencetnent  of  the  operation,  one  of  thtise  empty 
buckets  is  first  lowered  to  the  bottom  of  the  pit, 
and  when  it  is  filled  with  coals,  a  boy  who  is  sta- 
tioned above,  and  close  to  the  mouth  of  the  pit, 
lowers  the  end  of  a  leathern  pipe  which  he  holds  in 
his  hand,  and  this  immediately  fills  the  upper  buc- 
ket with  water.  This  being  now  heavier  than  the 
loaded  bucket  below,  it  begins  to  descend  with  con- 
siderable velocity  into  the  mine,  while  the  other 
ascends  with  equal  speed  and  soon  arrives  at  the  sur- 
face, charged  with  the  coal  Or  other  mineral  design- 
ed to  be  raised.  When  the  bucket  of  water  reaches 
the  bottom  of  the  pit,  it  is  interrupted  by  a  strong 
iron  pin  placed  vertically  in  the  ground,  exactly 
in  the  centre  of  the  spot  where  tlie  bucket  must 


424  ON   WATER. 

test ;  and  this  pin  forces  up  a  large  valve  in  the 
bottom  of  that  receptacle,  allowing  the  whole  mass 
of  water  to  escape  in  an  instant.  The  vessel  which 
has  arrived  at  the  top  of  the  pit  being  emptied,  this 
is  now,  in  its  turn,  filled  with  water^  while  the  inen 
below  are  loading  the  other  mth  the  mineral,  which 
is  then  to  be  raised  by  the  power  of  the  descending 
water,  as  before ;  the  buckets  continuing  to  ascend 
and  descend  in  rotation  and  without  interruption. 
The  specific  gravity  of  water  being  only  a  trifle 
greater  than  that  of  a  mass  of  loose  coal,  this  cir* 
cumstEince  renders  water  peculiarly  fit  for  the  use 
of  a  colliery  in  the  manner  above  described.  t 

'  It  is  obvious  however  that  this  contrivance  can- 
not be  adopted  every  where ;  but  I  am  perauadad , 
there  are  many  places  in  this  kingdom  where  mine^ 
nds  are  raised  at  a  very  great  expense,  thou^ 
their  situations  are  in  every  respect  favourable  finr 
the  employment  of  this  machine;  and  it  is  this 
consideration  which  made  me  desirous  of  explain^ 
ing  the  scheme  in  this  Eissay. 
'  Mines  are,  moreover,  frequently  opened  on  the 
side  of  a  hill  or  mountain ;  and  as  springs  of  water 
are  generally  to  be  found  in  those  situations,  this 
method  might  be  employed  in  all  such  places,  pro- 
vided there  be  either  a  rivulet  at  the  bottom  of  the 
mine,  or  that  a  fissure  in  the  rock  can  be  found,  to 
carry  ofi^  the  descending  water. 

I  had  forgotten  to  remark,  that  in  pronding  a 
stream  for  setting  this  apparatus  in  motion,  all  diat 
is  needful  is,  to  fix  a  wooden  spout  into  the  side  of 


ON  WATER.  425 

ft  pool  or  other  contiguous  reservoir  of  water,  exactly 
et^en  with  the  surface  of  the  water,  and  then  to  adapt 
a  flexible  tube  of  leather  or  other  suitable  material 
to  that  end  of  the  trough  which  comes  to  the  mouth 
iKlf  the  mine.  In  considering  this  arrangement,  it 
will  be  seen  that  the  mere  elevation  of  the  leathern 
end  of  the  pipe  a  few  inches  only,  will  entirely  pre- 
vent the  running  of  the  water ;  the  machine  there- 
JTore  may  be  kept  in  motion  at  any  time  by  a  child ; 
ftfid  when  it  is  not  at  work,  all  that  is  required  is  to 
fai^ng  the  end  of  the  pipe  upon  a  hook  fixed  iii  a 
post  at  the  side  of  the  pit,  when  the  current  will  in- 
stantly cease. 

•  I  might  here  attempt  to  describe  the  various  me- 
thods of  raising  water  from  great  depths ;  but  as 
this  would  lengthen  the  Essay  more  than  would  be 
desirable,  I  must  refer  the  inquiring  reader  to  Nichol- 
son's quarto  Journal  of  Natural  Philosophy,  where 
be  will  find  several  elaborate  memoirs  on  that  sub- 
ject, accompanied  with  plans  and  engravings  ^\ 

A  gentleman  in  the  neighbourhood  of  London, 
who  is  desirous  of  having  a  reservoir  of  water  at  the 
top  of  his  house,  has  it  in  contemplation  to  supply 
ithy  means  of  a  common  smoke  jack :  this  machine, 
which  will  be  in  constant  action,  is  to  work  an  end- 
lett  chain,  to  which  a  great  number  of  small  cups, 
ciqpable  of  holding  one  or  two  ounces  of  water  each, 
are  to  be  attached,  and  these  by  the  usual  contrivance 
will  empty  themselves  into  the  cistern  in  succession 
as  they  ascend. 

^'  See  Nichol8on*8  Journal,  quarto,  vol.  iv.  p.  165—466. 


426  ON  WATER. 

The  fertility  <^  Eg3rpt  in  consequeRce  of  the  an* 
ttual  inundation  of  tbe  Nile,  is  a  matter  of  gencfal 
notoriety ;  and  many  of  tbe  well  informed  agrkndk 
turists  of  these  kingdoms,  availing  themselvei  of 
the  knowledge  of  this  fact,  do  periodically  rapi% 
their  estates  with  artificial  currents  of.  water^  wd 
derive  great  benefit  from  the  practice. 
•    The  Chinese  have  long  known  how  to  value  the 
practice  of  watering  land  artificially.  **  I  observed/* 
says  Van  Braam,  **  several  mills  which  raise  tba 
water  of  the  river  above  the  banks,  whence  it  riuis 
into  reservoirs,  to  be  afterwards  diffused,  by  mcaas 
of  canals  and  aqueducts,  over  the  fields  that  requite 
irrigation.    These  mills  are  of  simple  constructioOt 
and  entirely  composed  of  an  assemblage  of  tUn 
bamboos,  except  the  axle-tree  of  the  wheel,  whkh 
is  of  timber.     In  no  part  is  the  smallest  pieee  «f 
iron  or  any  other  metal  employed.   The  whole  ma- 
chine, as  well  as  I  was  able  to  judge,  is  from  18  to 
28  feet  in  dianieter  ^*.*'     Being  myself  one  of  thos^ 
who  have  never  entertained  a  fear  of  the  state  being 
injured  by  the  land  becoming  too  productive,  and 
recollecting  that  it  wa^  said  of  old,  that  he  deserved 
well  of  his  country  who  could  make  two  blades  of 
grass  to  grow  where  only  one  grew  before,  it  is  ii^ 
cumbent  on  me  to  recommend,  in  the  most  forci* 
ble  terms,  the  practice  of  irrigation,  and  to  urge  its 
general  adoption.     M«  Desmarets  has  given  a  me- 


*"  Van  Brwim*s  Embassff  kkthe  Court  of  the  Emperor  of  CluMa, 
London  1798,  vol.  i.  page  72. 


0»  WATEIU  427 

moir  on  the  best  method  of  watering  meadowy,  in 
the  3d  volume  of  Memoirs  of  Agriculture,  published 
hy  the  Royal  Society  of  Agriculture  at  Paris.  A 
Hery  satisfM^tory  account  of  the  way  in  which  water 
aflla  on  the  different  organs  of  plants,  and  assists  ve- 
getadon,  may  be  read  in  Fourcroy*8  System  of  Che- 
mistry^. Several  memoirs  containing  ample  in- 
stmctions  for  the  general  nmnagement  of  the  business 
gf  irrigation  may  be  seen  in  the  Bath  Agricultural 
Bapera,  in  the  Transactions  of  the  Society  of  Arts» 
Vid  in  other  similar  puUications.  But  I  shall  |M>t 
haEve  mis-spent  my  time,  if,  by  making  an  extract  or 
two  from  the  works  of  some  of  the  best  writers  on 
the  subject,  I  should  be  the  means  of  exciting  the 
attention  of  any  of  our  practical  farmers,  so  aa  to 
induce  them  to  adopt  this  very  important  and  ad« 
vantageous  mode  of  culture. 

,  The  Reverend  Mr.  Wright  says  **  that  land  by 
Kgular  methods  of  watering,  whatever  be  its  kind 
and  quality,  is  increased  to  double  or  treble  ita 
former  value;  that  land  under  this  management 
does  not  require  dung,  but  is  itself  a  constant  source 
of  manure  to  other  fields ;  and  that  it  raises  grass 
in  the  spring  a  month  sooner  than  the  same  fields 
could  otherwise  be  made  to  yield  it^^. 


71  Fourcroy,  vol.  viii.  oage  359 — 366. 

7*  See  '*An  Account  of  the  Advantages  and  Methods  of  Waters 
ing  Meadows  by  Art,  as  practised  in  the  County  of  GUmcester,** 
By  the  Rev.  T.  Wright.  Small  8vo,  London  ]  789.  More  in- 
fermation  may  still  be  obtained  from  a  Letter  which  this  Gen- 
tleman wrote  to  the  Editors  of  the  Monthly  Review,  and  which 
b  printed  in  the  78th  volume  of  that  work^  at  page  671. 


428  ON  WATER. 

Mr.  Boswell,  who  has  written  a  more  elaborate 
treatise  on  this  subject,  says,  "  It  is  inconceivable 
what  twenty- four  hours  water  properly  conveydl 
over  the  land  will  do  in  a  dry  season ;  a  beaatifiii 
verdure  will  arise  in  a  few  days,  where  a  parchei^ 
rusty  soil  could  only  be  seen ;  and  one  acre  wBl 
then  be  found  to  maintain  more  stock  than  tin 
acres  without  such  management.  Moreover,  almdst 
the  whole  of  the  expense  in  this  mode  of  cultivatton, 
is  the  actual  manual  labour  of  a  class  of  people  who 
can  be  employed  in  no  other  way  for  the  support 
of  their  families ;  consequently  the  expenses  H^n  be 
comparatively  but  small,  though  the  imprbvemMt 
must  be  great  and  durable'*.'* 

Flooding,'*  sajrs  another  writer  on  this  subject, 

is  truly  the  best  of  all  improvements  where  it  can 
be  effected,  and  there  ought  not  to  be  a  single  atire 
of  land  neglected  which  is  capable  of  this  practice*".* 

It  is  related  of  Mons.  Pestre,  a  skilful  physida'n 
and  an  enlightened  cultivator  of  land  among  the 
Cevennes  mountains,  that  at  the  first  threatenings 
of  a  storm  he  used  to  clothe  himself  in  a  long  gar- 
ment of  oil  cloth,  with  an  enormous  hat  of  tinned 
iron  firmly  fixed  by  means  of  straps.  Thus  de- 
fended, he  hastened  into  the  midst  of  his  posses- 
sions, where  alone,  with  a  mattock  in  his  hand,  he 
directed  the  water  to  the  feet  of  his  trees,  and  col- 


'*  Bosweira  Treatise  on  ff^atering  Meadows,  illustrated  with 
five  copper-plates.  Third  edition,  octavo,  London,  1 792,  page  12. 
*^  Kent*s  Hints  to  the  Landed  Interest,  London,  Oct.  1775. 


ON  WATER.  4'i9 

lected  tiie  surplus  in  cavities  which  he  had  formed 
in  the  rock  itself.  By  these  exertions  he  constantly 
prevented  injurious  inundations  on  his  estate,  and 
procured  water  for  his  ground  at  such  times  when 
the  burning  heats  rendered  it  necessary.  His  neigh- 
bours, who,  as  usual  in  such  cases,  at  first  derided 
him,  were  constrained  to  admire  his  industry  and 
envy  his  gains  ;  for,  in  consequence  of  this  labour, 
he  quadrupled  the  usual  product  of  his  grounds. 

There  is  a  most  interesting  and  highly  entertain- 
ing memoir  on  the  means  of  improving  mountain- 
ous districts,  and  from  which  I  extracted  this  ac- 
count, in  the  3d  volume  of  Nicholson's  quarto 
Journal  of  Natural  Philosophy,  &c.  page  '295. 
"  Mucli  has  been  already  done,"  said  the  late 
amiable  Dr.  Percival  at  the  conclusion  of  his  Essay 
on  the  Oreliis  Boot,  "forthe  advancementofagri- 
culture,  but  the  earth  still  teems  with  treasures 
which  remain  to  be  explored.  The  bounties  of 
nature  are  inexhaustible,  and  will  for  ever  employ 
the  art  and  reuard  the  industry  of  man." 

Another  equally  striking  proof  of  the  influence 
of  water  on  vegetation  maybe  found  in  the  very  re- 
markable industry  of  the  gardeners  who  cultivate 
the  marshes  near  Paris.  From  these  marshes, 
situate  all  around  that  great  city,  they  derive  large 
profits  ;  they  cover  the  ground  with  abundant  and 
uninterrupti'd  crops,  and  they  are  indebted  for  this 
almost  astonishing  series  of  vegetable  production  to 
the  enormous  quantity  of  water,  which  they  are  in- 


430  ON   WATER. 

cessantly  conveying  into  their  grounds**,  and  to  the 
continual  waterings  with  which  they  fertilise  them**. 

We  read  of  a  very  extraordinary  stream  of  water 
that  supplies  the  public  baths  of  St.  Philips  in 
Tuscany^  which  carries  a  peculiar  kind  of  eardi.  or 
earthy  salt,  in  its  current.  This  earth,  when  it  is 
collected  and  condensed  in  the  cavides  of  any  body 
that  is  employed  to  oppose  its  course,  acquires  the 
nature,  hardness,  and  colour  of  alabaster,  and  as- 
sunies  the  forms  of  the  caviUes  in  which  it  is  thus 
collected.  The  ingenious  Mr.  Latapie,  conviaoed 
by  repeated  experiments  of  this  singular  property 
of  the  water  of  these  baths,  had  moulds  made  qj[ 
several  single  figures,  and  even  groups ;  and,  by 
placing  them  in  a  certain  manner  against  the  currei^l 
of  this  stream,  he  collected  in  their  cavities  the 
earth  in  question,  and  thus  formed  basso  relwqs 
of  beautiful  alabaster.  This  success  enabled  him  at 
length  to  establish  a  manufacture,  which  has  ren- 
dered the  finest  productions  of  sculpture  more  easily 
attainable  in  that  part  of  the  country  than  Uiey  had 
hitherto  been,  and  much  more  precious  by  the  ac« 
curacy  of  the  copy". 

'*  One  might  imagine  that  Moses  was  acquainted  with  the 
advantage  of  irrigation  to  agriculture  and  gardening.  '^  A  river,'* 
says  he,  '*  went  out  of  Eden  to  water  the  garden.**  Genesis, 
chap.  ii.  ver.  10. 

**  Fourcroy's  System  of  Chemistry,  vol.  viii.  page  359. 

^  For  an  account  of  this  singular  manufactory  see  Roskt^s 
Journal  for  June  1776  ;  or  the  Monthly  Review  for  November 
1776,  page  391. 


ON    WATER.  431 

But  it  would  be  an  endless  attempt  to  endeavour 
to  enumerate  all  the  various  kinds  of  water  which 
have  been  noticed  by  the  respective  writers  who 
have  given  ns  accounts  of  their  travels  into  different 
parts  of  the  world.  I  therefore  conclude  with  the 
more  pleasing  task  of  inviting  the  contemplative 
reader  to  devote  a  moment  or  two  to  the  recollec- 
tion of  a  few  of  the  more  obvious  advantages  which 
we  derive  in  every  quarter  of  the  globe  from  the 
possession  of  water. 

Water  is  indispensable  as  the  beverage  of  man 
and  other  animals ;  as  the  medium  for  conveying 
nourishment  to  vegetables;  and  for  rendering  ef- 
fective those  important  senses  of  sight,  taste,  and 
smell.  It  has  been  well  remarked,  that  that  most 
wonderful  machine  the  eye  can  only  represent  ob- 
jects to  our  senses  by  the  means  of  humours  com- 
posed chiefly  of  water  ;  and  that  the  glassy  coats  of 
this  important  organ  must  lose  their  transparency, 
were  they  not  constantly  moistened  with  water. 

I  am  supported  in  this  assertion  by  the  testimony 
of  an  anatomist  of  great  credit  and  respectability. 
"  Because,"  says  he,  "tlie  outermost  coat  of  the  eye 
might  be  pricked,  and  this  humour  let  out,  there- 
fore nature  hath  made  provision  to  repair  it  by  the 
help  of  certain  wa/tr-pipes,  or  lymphieducts,  in- 
serted into  the  bulb  of  the  eye,  proceeding  from 
glandules  that  separate  this  water  from  the  blood**." 

"  Ray's  Phi/tito-Theulogicni  Ducouritet. 


432  ON   WATER. 

In  like  manner  with  regard  to  sfuell^  the  respective 
odours  of  bodies  are  collected,  blended,  perfected, 
and  preserved,  by  means  of  water ;  nor  could  thejr 
be  conveyed  to  the  proper  nerves  had  not  nature 
supplied  these  parts  with  humidity,  at  once  to  lubri- 
cate the  vessels,  and  to  collect  the  odoiifierous  exha« 
lation .  * '  The  use  of  this  pituitar  says  Mr.  Gioper. 
**  is  to  keep  the  membrane  soft.  By  this  means  the 
ol&ctory  nerves  expanded  on  this  membrane,  are 
rendered  capable  of  the  perception  of  odoriferous 
effluvia,  which  otherwise  the  dryness  of  the  part 
would  destroy^.**  Neither  is  any  body  sapid,  unksi 
it  either  contain  water  or  be  dissolvable  therein  j 
for  it  is  well  known  that  those  substances  which  an 
most  soluble  in  water,  soonest  imprint  the  sense  o| 
taste  upon  the  organs  which  are  desUned  to  recdve 
that  impression :  a  dry  tongue  can  no  more  taste 
than  dry  nostrils  smell,  or  a  dry  eye  distinctly  see"*. 

The  most  beautiful  tints  of  flowers^  would  also 
be  unable  to  please  us  if  they  were  divested  of  water; 
nor  would  any  of  the  products  of  the  vegetable 
kingdom  be  capable  of  fermentation,  were  it  not  for 
the  intervention  of  this  important  fluid.  Clay  would 
be  mere  useless  dust  without  water,  and  incapable 
of  being  modelled  into  any  of  the  beautiful  forms 

*^  Mr.  William  Cooper's  Dissertation  on  the  Smelly  published 
in  Drake's  Anatomy,  vol.  ii.  London^  Third  Edition,  page  313. 
•^  See  Dr.  C.  Lucns  on  Water,  8ro,  London  1 75  G,  page  79. 
^  Even  the  lustre  of  the  diamond  is  often  compared  to  water : 

"  *Tis  a  good  form. 

And  rich:  here  is  a  water,  look  ye." 

Shakespcark. 


ON    WATER.  43) 

in  which  we  now  see  it,  or  applied  to  any  of  ita 
present  important  uses.  Lime  and  sand  might  be 
mixed  and  blended  for  ever  without  their  forming 
a  compact  mass ;  but  by  the  addition  of  water  they 
acquire  the  property  of  hardening,  and  of  forming 
for  an  excellent  cements  and  durable  habitations^. 

Almost  all  chemical  operations  require  the  pre- 
sence of  water,  and  many  others  cannot  be  conducted 
to  any  advantage  without  its  assistance.  The  most 
powerful  and  heterogeneous  salts,  if  perfectly  dry, 
may  be  mixed  without  any  seeming  effect ;  and  few 
if  any  decompositions  could  be  produced  without 
the  agency  of  this  alUpervading  and  important  fluid. 
The  processes  of  decoction,  solution,  distillation, 
precipitation,  and  crystallization,  are  all  dependent 
upon  water  for  their  success.  Starch,  glue,  and 
every  other  kind  of  mucilage,  owe  their  tenacity  to 
water ;  and  it  is  probable  that  most  of  the  sub- 
stances on  the  face  of  the  earth  would  fall  into 
shapeless  or  pulverulent  masses,  useless  and  inert, 
were  it  not  for  the  binding  effects  of  this  most  ac- 
commodating and  wonderful  fluid'*. 

There  are  also  various  reasons  for  believing  that 
the  salubrity  of  the  atmosphere  is  preserved  by 
means  of  water  ;  and  we  are  surely  not  a  little  in- 


;  that  thne  lUHertians  have  already-  been  obun- 
danily  proved  by  difierent  iliustrations  in  the  former  part  of 
Ibis  Etuay.     See  pages  363—366. 

•  Pemons  deairoufi  of  investigating  this  curiotis  subject  may    ■ 
read  the  firat  volume  of  Boerhaave's  EUtnenli  of  Chematrj/ 
with  great  advantage ;    also  Campbell's  Political  Survey  of 
Orent  Britain,  quarto,  vol.  i.  chap.  v.  pages  67 — 133. 
VOL.  II.  2  F 


434  ON   WAT£Jl. 

• 

debted  to  the  Great  original  Contriver  of  all  things 
for  that  immense  accumulation  of  this  fluid  which 
is  collected  in  the  ocean,  by  means  of  which  we  are 
enabled)  without  labour  or  fatigue,  to  visit  every 
clime  oh  the  surface  of  our  globe ;  to  barter  the 
valuable  products  of  each  with  one  another ;  and  to 
interchange  all  the  important  blessings  of  religion, 
literature,  science,  civilization,  and  the  arts. 


?:SSAY  XIV. 


ON 


S  A  L-A  M  M  O  N  I  A  C. 


2f2 


ESSAY  XIV. 


SAL-AMMONIAC. 


DAL-AMMONIAC,  or  Muriate  of  Ammonia,  is  a 
peculiar  neutral  salt,  well  known  to  the  ancients. 
From  the  name  which  this  production  has  always 
borne,  it  is  extremely  probable  that  it  was  first  col- 
lected at  Ammonia,  a  country  which  occupies  the 
midland  part  of  Libya  in  Africa,  closely  bordering 
on  Egypt. 

Several  eminentmen  had  the  nameof^/wnomW. 
One,  who  was  the  preceptor  of  Plutarch,  flourished 
in  the  time  of  Nero.  Ammonius  Saceas  was  the 
master  of  Origen,  the  great  apologistof  Christianity ; 
and  there  was  another  philosopher  of  this  name 
who  lived  in  the  6th  century,  a  disciple  of  Proclus 
and  himself  the  preceptor  of  the  celebrated  Simpli- 
cius,  who  wrote  the  Commentary  upon  Epictetus. 

The  ancient  Temple  of  Jupiter  Ammon  was 
also  situated  in  the  country  above  mentioned,  and 
the  proprietors  of  the  stables  for  the  reception  of 
the  camels  of  the  pilgrims  had  contrivances  for  pre- 
serving the  urine  of  these  animals  for  the  manu- 


438  ON    SAL-AM>|ONIAC. 

facture  of  sal-ammoniac  ^  In  consequence  of  thii, 
the  traffic  in  muriate  of  ammonia  became  very  ecm- 
i  derable,  and  the  ancient  Grreeks  and  Romans,  who 
employed  this  singular  salt  for  many  purpoMi^  ffo- 
cured  their  supply  from  that  quarter.  In  proens 
of  time,  the  native  E^ptians  also  learnt  how  to 
make  sal-ammoniac,  and  for  many  ages  the  wliok 
of  Europe  had  no  means  of  obtaining  thiB  salt,  ex- 
cept by  importing  it  from  that  country. 

According  to  Pococke  and  Niebuhr,  manofiscto- 
ries  in  later  times  were  erected  for  the  express  pur- 
pose of  making  this  saline  compound,  at  Dsjise,  fX 
Geeza,  and  at  Rosetta  a  sea-port  on  the  coast  of  Alex- 
andria, as  it  was  found  impossible  for  thei  i<4i^llf 
Europe  to  besuppUed  from  the  original  makiufiMoiy. 

In  the  year  )7M  Geoffiroy,  a  eielebriit^  ^clfietflik 
and  physician  of  Paris,  read  to  the  Academy  %,iat- 
moir  on  the  composition  of  muriate  of  ammoiiia^^iMl 
gave  it  as  his  opinion  that  it  came  from  BgyptaJMl 
was  the  product  of  sublimation.  In  the  year  i^W 
he  published  an  account  of  a  series  of  experimeoti, 
to  prove  that  sal-ammoniac  might  be  made  profitih 
bly  in  Europe. 

Little  was  known  however  of  the  methods  by 
which  this  salt  was  procured  in  Egypt,  until  die 
year  1719,  when  Lemere,  the  French  Cons^  at 
Grand  Cairo,  sent  an  account  of  its  manufacture  to 
the  Academy  of  Sciences  at  Paris,  who  published  it 
in  one  of  the  volumes  of  their  Transactions.  I 
suspect  this  French  Consul  to  have  been  a  diifereM 

•  '  Plinyi  lib.  xxxi.  cap.  7. 


ON    SAL-AMMONIAC.  439 

person  from  Nicholas  Lemery,  the  celebrated  cbe» 
mUt  of  Rouen,  who  I  believe  died  early  in  the  eigh- 
teenth century.  He  might  perhaps  have  been  a 
son  of  the  aforementioned  Nicholas,  for  he  was  also 
an  eminent  chemist  and  likewise  physician  to  the 
French  king.  The  following  is  liowever  an  abridged 
detail  of  the  process,  as  given  by  Lemere. 

The  natives  of  Egypt  (says  he)  collect  for  this 
purpose  the  excrements  of  camels,  oxen,  and  othtr 
animals  which  feed  on  saline  plants.  These  excre- 
ments are  dried  by  applying  them  to  the  surface  of 
walls ;  and  wlien  they  are  sufficiently  dry,  they  are 
burned  as  fuel  in  their  common  household  fires.  It 
is  from  the  soot  afforded  by  these  burning  sub- 
stances that  the  muriate  of  ammonia  is  extracted. 
For  this  purpose  the  i^oot  is  put  into  large  glass  bot- 
tles 1 8  or  19  inches  in  diameter,  terminating  in  a 
neck  several  inches  high.  These  glasses  are  filled 
to  within  four  6ngers  breadth  of  the  neck,  and  gra- 
dually heated  for  7'1  hours.  Towards  the  second 
day  the  muriate  of  ammonia  sublimes,  and  adheres 
to  the  upper  part  of  the  bottles.  When  the  process 
is  finished  and  the  whole  apparatus  has  been  well 
cooled,  the  ve:isels  nre  broken,  and  the  lumps  of  am- 
inoniacal  salt  are  token  out  for  sale*.  Five  [wunds 
of  the  soot  procured  from  the  burning  of  this  ex- 
crementitious  matter  are  expected  to  produce  one 
pound  of  muriate  of  ammonia. 

Here  it  may  be  worth  observing  that  the  soot  of 
NeH*castle  coals  will  produce  an  abundance  of  sal- 


440  ON   SAL-A10fDNlAC;4 

anunoniac.  Some  few  yean  ago  there  was  a  eon- 
•uderable  manu&Gtbiy  of  this  salt  in  the  ndghboar- 
iiood  of  London,  which  was  supplied  entirely  hy  the 
common  soot  collected  from  the  chimnejra  in  tfie 
thetropolis. 

Respecting  the  African  sal-ammoniac,  other 
writers  relate,  that  as  sea  salt  is  always  given  bbpi- 
oiisly  to  the  camels,  during  their  journeys  in  die 
caravans  over  the  Desert  to  Alexandria,  their  urine 
and  dung  consequently  become  very  replete  mth  the 
salt.  The  dung  of  these  animals  being  burnt  ia 
the  public  ovens  for  hatching  chickens  for  tfae^  ca- 
ravans, and  also  in  their  common  fires  for  culinaiy 
purposes,  tlie  volatile  salt  is  produced  in  the  loo^ 
and  this  requires  only  to  be  purified  by  sublimatiiNK 
in  order  to  form  the  cakes  of  muriate  of  ammoiua 
wluch  are  exported  to  Europe. 

Chaptal  relates,  that  he  obtained  sal-ammoniac 
from  the  soot  of  cow-dung  and  that  of  horses^  whidi 
run  wild  in  the  immense  plains  of  Camargue  and 
Crau,  and  upon  theborders  in  the  numerous  marahes 
in  the  vicinity  of  the  Mediterranean,  but  that  he 
soon  found  he  could  only  procure  it  from  the  dung 
of  these  animals  while  they  continued  to  live  do 
marine  plants. 

Another  account  of  the  Egyptian  manufacture  mij 
be  seen  in  Hasselquist's  Travels  in  the  Levant,  b 
difiers  in  some  respects  from  the  foregoing,  but  it  b 
extremely  interesting.  He  relates  that  the  poor  inha- 
bitants of  Egypt  are  occupied  for  several  months  of 
the  year  in  collecting  the  excrementitious  products 
already  spoken  of ;  that  they  mix  these  with  cut 


ON    SAL-AMMONIAC. 


441 


straw  to  assist  its  drying  ;  that  when  dried  they  use 
it «  fuel,  having  in  reality  no  other  kind  ;  ind  that 
they  make  a  business  of  collecting  the  soot  from 
nil  parts  of  the  country  to  sell  to  the  sal-ammo- 
niac makers  at  Grand  Cairo. 

When  the  origin  of  this  volatile  salt  had  thus 
been  made  known,  it  was  soon  discovered  that  it 
was  a  compound  body ;  that  it  emsted  ready  formed 
in  some  parts  of  the  earth  ;  and  that  it  consisted  of 
a  peculiar  alkaline  substance,  in  close  union  with 
muriatic  acid. 

The  acid  which  was  found  to  be  one  of  its  com- 
ponent parts  had  been  known  for  a  century  before, 
»nd  employed  for  a  variety  of  purposes ;  but  thie 
"Was  not  the  case  H-ith  its  base,  the  ammonia,  or 
Volatile  alkali,  which  engaged  the  attention  of  che- 
inists  for  many  years  afterwards,  and  long  before 
its  nature  and  properties  were  at  all  understood,  or 
that  it  had  been  even  suspected  to  be  any  thing 
more  than  a  simple  undecomposnble  body. 

Tournefort  was  the- first  chemist  who  asserted 
that  sal-ammoniac  is  composed  of  muriatic  acid  and 
ammonia:  he  made  this  known  in  the  year  1700. 
Muriate  of  ammonia  is  sometimes  found  in  the  en- 
virons of  volcanoes,  and  in  a  state  of  solution  in 
some  lakes  in  Italy  and  Tuscany  ".  It  exists  also  in 
^e  mountains  of  Tartary,  in  Thibet,  and  in  the 
grottos  in  the  vicinity  of  Pouzzola  *.  This  salt  is 
likewise  found  in  the  country  of  the  Kalmucks,  and 


i  Roxier'i  Journal,  xvi,  page  362. 

L  fWrcroy's  S^item  of  Ckmkal  Knou^Mge,  vol.  i 


44^  ON   SAL* AMMONIAC. 

sent  from  thence  into  various  parts  of  RusMa  far 
sde.  The  specific  gravity  of  muriate  of  anunoidft 
is  1.420*;  it  is  soluble  in  rather  more  than  tlirte 
•times  its  own  weight  of  water  in  the  temperatnie 
of  60^,  and  in  an  equal  weight  of  water  whep  !it 
212*.     Its  solution  produces  cold. 

According  to  the  Baron  Riedesel,  muriate  'of 

ammonia  is  found  plentifully  in  the  neighbourhood 

of  Mount  Etna.    He  remarks  that  *'  the  lava  is  aM 

various  and  beautiful  like  that  of  Vesuidus»  <rf  wbieb 

above  forty  kinds  have  been  collected,  for  diat  the 

lava  of  this  mountain  contains  chiefly  iron  and  Jof- 

ammoniac  *.    Wiegleb  states,  that  sal-ammoniae  m 

met  with  at  the  apertures  and  fissures  of  theinla^ 

■nal  crater  of  Mount  Vesuvius,  but  that  the  subB- 

.mation  is  never  observed  till  twcr  months  after  the 

•eruption  ^  i 

Basil  Valentine,  who  wrote  in  the  15th  oentuiy^ 
spieaks  of  sal-ammoniac ;  and  Geber,  who  lived  6(10 
years  earlier,  classes  it  among  volatile  bodies,  ^sbA 
gives  directions  about  subliming  it  ^ 

In  the  year  1773,  Dr.  Priestley  separated  the 
ammonia  from  sal-ammoniac  by  means  of  quicA 
lime,  and  exhibited  this  alkali  for  the  first  time  in 
the  state  of  gas.  He  may  therefore  be  said  to  have 
been  the  real  discoverer  of  ammoniacal  gas  ^    This 

^  Bp.  Watson  states  it  to  be  1 .4.'>0.  ^eRChemical  Essa^M,y.  67. 

•  Riedesers  Travels  through  Sicily,  3rc.  translated  by  Foster, 
8vo>Ix)ndon  1779. 

'  Hopson's  Translation  of  Wiegleh,  p.  226. 

^  SecK\Ji»&^WTranslationofGeber*sWorks,hoit{doii  1678,p.7. 

»  See  Priestley*8  Experiments  on  Air,  octavo^  London  1781, 
vol.  i.  page  166. 


ON    SAL-AMMONIAC.  4J3 

gaseous  substance  was  afterwards  examined  by  him 
in  various  ways,  and  be  even  succeeded  in  decom 
posing  it  by  means  of  electricity;  but  it  does  not 
appear  that  lie  had  conceived  any  idea  of  the  nature 
of  its  composition,  though  he  seems  to  have  been 
well  acquainted  with  the  compound  nature  of  the 
salt  from  which  he  extracted  the  alkaline  gas.  The 
honour  of  this  latter  discovery  was  reserved  for 
Scheele  and  Bergman;  and  about  the  year  1785 
BerthoUet  published  a  meuioir  which  confirmed  the 
account  previously  given  by  the  foregoing  chemists, 
that  oninionia  is  a  compound  of  nitrogen  and  by* 
drogen.  Btrthollet  pronounced  ammonia  to  be  a 
compound  of  1  '2 1  parts  by  weight  of  nitrogen,  with 
29  of  hydrogen,  proportions  which  have  since  been 
almost  exactly  confirmed  by  other  chemists  '".  Jt 
is  probable,  however,  that  the  real  composition  of 
ammonia  is  13  nitrogen,  and  3  hydrogen,  wiiicb 
will  make  its  equivalent  number  Ui.  Muriate  of 
ammoniH,  or  sal-ammoniac,  is  composed  of  one  pro. 
portional  of  ammonia  l(j  combined  with  one  pro- 
portional of  muriatic  acid  34.5,  and  its  equivalent 
number  is  50.5. 

Piue  ammonia  is  knoivn  only  in  the  state  of  gas. 
This  gas  has  a  very  pungent  and  acrid  smell,  but 
when  plentifully  diluted  with  utmospherlc  air  its 
odour  is  rather  pleasant  and  refreshing;  it  is  a  co- 
loniless  gas,  and  being  much  lighter  than  alinu- 
speric  air,  it  is  of  course  volatile. 

Ammonia  is  also  caustic  and  corrosive,  and  will 


rMfytoira  dc  I' Acadimie  rff«  .s 


,  I /(*,),  page  3 


444  ON  Mja^AMMtmiMCj 


unite,  mtb  oil  into  a  satHMiaorout  coiiqpouMi ;  Imt 
it  bw  not  the  power  of  acting  tblent^  on  ommri 
snbstances  liketlie  fixed  alkalies^  potash,  and  soda. 

Ammonia  is  capable  of  uniting  witii  otioit  'Of .  the 
aeids,  and  forming  with  them  neutral  salts.  Hius 
we  have  carbonate  of  ammonia,  nitrate  of  ammonia, 
sulphate  of  ammonia,  muriate  of  anunonia,  and 
Other  salts,  with  this  alkali  for  their  base. 

The  sulphate  and  muriate  of  ammonia  have  been 
found  native  in  the  ncig^ibourhood  of  volcanoes  and 
in  other  parts  of  the  globe;  the  triple  salt  oaifed 
phosphate  of  soda  and  ammonia  is  found  in  hnmaa 
urine; and  since  the  decomposition  of  sal-anmiosusB 
has  been  understood,  several  other  salts  have  been 
formed  in  the  laboratory  by  its  means  for  porpoMs 
of  medidne  and  for  various  uses  in  the  arts. '  Klajp^ 
toth  analysed  a  spedmen  of  native  sal-ammoniae 
from  Mount  Vesuvius,  and  found  it  to  be  an  uncoil* 
taminated  muriate  of  ammonia,  free  from  aulpbitoie 
acid,  though  the  salt  must  have  been  generated  in 
an  atmosphere  impregnated  with  su^hureous  ex- 
halations. He  considers  this  salt  to  be  a  prodoet 
of  the  mountain ;  that  its  basis,  the  ammomi^  is 
composed  of  the  hydrogen  and  nitrogen  from  the 
Water,  and  the  atmospheric  air,  which  during  tbat 
great  chemical  operation  of  nature  undeigo  decom* 
position ;  and  that  this  ammoniacal  gas,  uniting 
with  the  acid  gas  from  the  decomposed  muriate  irf 
soda  of  the  sea  water  which  finds  its  way  into  tiie 
volcano,  forms  tlie  muriate  of  ammonia  in  question". 


**  KiapnMn  diial9UcalEm^,v6Lii.  fag^W. 


ON    SAL-AMMONIAC. 


445 


The  Bokarian  Tartary,  a  district  of  Usbeck  Tar- 
Ury,  in  Asia,  also  furnislit^  a  native  muriate  of 
■mmotuH.  Klaproth  examined  a  specimen  of  thi> 
salt,  and  found  it  to  consist  of 

Muriate  of  Ammonia  .....     97.50 
Sulp)iate  of  Ammonia       ....      2^0 


We  have  also  fluate  of  ammonia,  the  arseniate  of 
ammonia,  the  acetate  of  ammonia,  the  oxalate  of 
aiDmonia,  andthephosphateof  ammonia  ;  the  latter 
of  these  Is  much  employed  as  a  Hux  for  the  blow* 
npe,and  in  makingpastes  to  imitate  precious  stones. 

None  of  the  aniinoiiiacal  salts  however  are  con- 
sumed or  manufactured  In  such  abundance  as  the 
muriate  of  ammonia,  the  immediate  subject  of  this 
Kssay;  its  uses  and  application  are  very  general 
and  too  various  to  be  enumerated,  though  the  men- 
tion of  a  few  of  them  will  show  the  great  import* 
ance  of  this  saline  compound. 

It  is  employed  by  the  dyer  to  moderate  the  action 
of  nitric  acid  In  tlie  preparation  of  nitrate  of  tin, 
and  also  to  modify  the  hue  of  some  particular 
colours.  Tlie  alkaline  part  of  this  salt  is  employed 
by  dyers  in  connection  with  archil,  an  article  which 
cannot  be  prepared  without  ammonia.  It  is  like- 
wise used  by  certain  artists  in  the  process  of  solder- 
ing; by  the  workers  In  copper  and  iron,  to  prevent 
the  oxidizenient  of  the  metallic  surfaces  which  they 
intend  to  cover  with  tin;  in  pharmacy,  for  the 
preparation  of  several  important  medicines ;  by  the 

"  KlMpcolb's  Analytical  EmrnrB,  vol.  ii.  page  71. 


446  ON  sals-ammoniac: 

makers  of  snuff,  in  order  to  render  that  arti^ 
inore  stimulant  and  poignant;  and  by  the  manu- 
facturing and  philosophical  chemist,  Icnt-  the  pro^ 
duction  of  artificial  cold ;  for  analysing  oertno  me-* 
tallic  substances ;  for  the  extraction  of  pure  liquid' 
ammonia,  and  for  the  preparation  of  the  ammoni- 
.  acal  salt  with  which  smelling-bottles  are  filled,  and 
which  on  account  of  its  solid  form  is  in  a  variety  of 
ways  convenient  and  useful.  I  have  been  informed 
by  a  chemist  of  Birmingham,  that  not  less  than  20 
tons  of  sal-ammoniac  are  annually  consumed  in 
that  town  by  the  workers  in  metal  only. 

When  chemists  had  discovered  the  methods  of 
separating  the  volatile  alkali  from  sal-ammoniac^ 
and  had  become  generally  acquainted  with  ibe.^ 
nature  of  this  gas^  attempts  were  soon  made  to  did* 
cover  other  sources  from  whence  it  might  be  pi^  * 
cured,  besides  that  of  muriate  of  ammonia.     It  llrid 
been  perceived  that  it  was  frequently  disengi^ged; 
from  animal  and  vegetable  substances  when  in*  a ' 
state  of  putrefaction ;  it  was  therefore  natural  to 
examine  a  variety  of  these  substances  for  its  pro- 
duction, and  it  was  soon  found  that  fish,  animal 
horns,  bones,  hoofs,  &c.  when  submitted  to  dry 
distillation,  would  yield  this  curious  and  peculiar 
substance  in  abundance.   It  should  be  remembered 
that  all  the  above  animal  substances  yield  ammonia  - 
exactly  in  proportion  to  the  quantity  of  nitrogen  con-* 
tainedin  them.    Dr.  Austin  asserts,  that  ammonia 
is  always  formed  where  iron  rusts  in  water  which  has 
a  constant  communication  with  the  atmosphere. 

'*  See  the  Pful.  Trans,  vol.  Ixxviii.  page  379. 


ON    SAL-AMMONIAC.  447 

A  plentiful  source  of  ammonia,  accessible  to  ttie 
people  of  all  countries,  and  at  all  seasons,  having 
thus  been  discovered,  it  immediately  became  a 
desideratum  how  to  combine  it,  at  a  cheap  rate'*, 
with  muriatic  acid,  so  as  to  form  uiuriate  of  am- 
nionic, and  preclude  the  necessity  of  sending  in 
future  to  Egypt  for  a  supply  of  this  useful  and  im- 
portant salt;  and  this  gave  rise  to  the  several  ma* 
nufactories  established  in  different  parts  of  Kuropt^ 
for  this  purpose. 

Wiegleb,  the  eminent  German  chemist,  says 
that  the  first  European  sal-ammoniac  manu- 
factories were  established  in  England  and  Scotland; 
that,  soon  after  tliese,  one  was  set  up  at  Paris  by 
Baum^  and  then  another  at  Brunswick  in  Ger- 
many, in  the  year  1759,  by  two  brothers  of  the 
nameofGravenhorsts,  which  were  followedbydivers 
others.  In  the  year  1756,  a  very  considerable  ma« 
nubctory  of  this  salt  was  established  by  Messrs. 
Dovin  and  Hutton  at  Edinburgh '\ 

When  the  ammonia  had  been  procured  as  above 
mentioned,  the  most  obvious  method  of  forming 
sal-ammoniac  was  that  of  a  direct  mixture  of  the 
acid  with  the  alkali ;  but  when  the  first  cost  of  the 
two  materials,  the  muriatic  acid  and  the  ammonia, 
was  considered,  together  with  the  great  loss  of  gas 
wbich  is  always  sustained  by  the  mixture  of  these 
two  volatile  substances,  it  was  found  that  the  pro- 


•  Various  proposah  to  this  end  were  printed  in  the  first 
une  of  Weber'H  Phyiico-Chemical  Magazine  for  1 780. 
|^,.5m  Hugo  Aniot'«  lhitor<j  of  Edinburgh,  Ito,  pnge  601 . 


448  cm  SAii-AkCMONiAC. 

eet8»  thus  eonducted,  could  not  be  carried  on  to 
mny  advantage  in  thia  country. 

At  thia  period  hovvever  the  resourcea  of  diemnta 
had  become  much  augmented,  and  evevf  emiaeat 
practitioner  in  Europe  waa  banning  to  »ml  Idm^ 
aelf  of  the  method  of  forming  neviF  suba taneea  -kjr 
meana  of  thuble  eleeihfe  jaiiracikm^  or  an  inter^ 
change  of  principles,  arising  from  the  nnxtuie  of 
different  compounds,  one  of  the  most  vakiaUa 
branches  of  chemical  science. 

Here  it  may  be  remarked,  that  Stahl  aeema  to 
have  been  the  first  person  who  propagated  the  idea; 
that  a  compound  substance  could  not  be 
posed  without  the  intervention  of  some  other 
stance  which  has  a  superior  afl&nity  for  on^of-lfct 
component  parts  of  the  original  compound,  la 
the  year  1718  Geoffiroy  published  the  first  taUeaf 
chemical  affinity.  This  table  waa  enlarged  aad 
improved  by  Grellert  in  the  year  1750,  and  in  the 
year  1775  Bergman  gave  to  the  world  his  ineati 
mable  treatise  on  elective  attractions,  wbi^  was 
published  in  English  in  the  year  1785 :  and  aince 
then  our  knowledge  of  the  subject  has  been  muok 
increased  by  Morveau,  Kirwan,  WoUaston,  and 
other  eminent  labourers  in  this  important  depart- 
ment of  science. 

The  knowledgeof  the  property  which  several  of  the 
salts  possess  of  mutually  decomposing  each  ether, 
naturally  laid  the  foundation  for  the  discovery  of  a 
more  economical  method  of  forming  the  muriate 
of  ammonia,  so  as  to  avoid  the  great  loss  of  gas 
which  idways  happens  on  the  direct  mixture  of  Kqiiid 


ON  SAX-AMMONIAC.  449 

tmmbnU  with  muriatic  acid,  of  which  there  h^A 
hitherto  been  so  much  complaint. 
/  This  ingenious  method  consists  in  first  saturating 
ibe  alkali  with  sulphuric  acid,  which  may  be  done 
with  little  or  no  loss  of  the  ammoniacal  gas,  and  then 
decomposing  the  sulphate  of  ammonia'*  which  is  thusi 
formed,  by  the  mixture  of  a  determinate  portion  of 
muriate  of  soda.  In  this  process  it  is  observable  that 
tiM  sulphuric  acid  is  not  entirely  lost,  for  it  com^* 
bines  with  the  soda,  and  produces  Glauber's  salt. 
V  The  result  of  this  mixture  and  of  the  reciprocal 
decomposition  of  the  two  salts  just  mentioned, 
bong  muriate  of  ammonia  and  sulphate  of  soda,  it 
i9<Kistomary  to  concentrate  the  saline  mass  byeva- 
peration  to  that  point  at  which,  when  the  liquor 
beeomes  cold,  the  sulphate  of  soda  will  separate  it- 
self by  priority  of  crystallization,  and  then  to  boil 
die' remaining  fluid  to  a  dry  shit,  which,  by  an  ade- 
quate  degree  of  heat,  is  afterwards  sublimed  into 
Mrfid  cakes  of  sal-ammoniac,  for  sale. 
.'  By  this  process  most  of  the  sal-ammoniac  made 
lA  this  country  has  for  many  years  post  been  pre- 
paired.  But  the  price  of  the  English  salt  has  been' 
90  high,  owing  to  the  first  cost  of  the  materials  and 
tbe'cxpense  of  the  process,  that  the  foreign  sal-am- 
moniac has  been  sold  much  cheaper ;  so  that  most 
of  the  consumers  have  given  the  preference  to  the 


'*  Sulphate  of  ammonia  consUU  of  one  proportional  of  am- 
monia 1 6 + sulphuric  acid  37' 5,  which  makes  its  equivalent  num- 
ber 53  5. 

VOL.  II.  2  G 


AW  ON  SAL»AMMONlA€. 

titter,  and  this  has  occasioned  the  consunaption  oi 
the  Englbh  to  be.  limited  and  very  incM>D8iderable. 
This  state  of  things  has  however  lately  undeigooe  a 
coinplete  revolution ;  and  from  some  circumstanctt 
to  be  adverted  to  hereafter,  sal-ammoniac  can  nom 
be  prepared  in  England  as  cheaply  as  in  any  pert  ot 
the  world. 

Sal-ammoniac  does  not  acquire  any  new  psoperi 
ties  by  the  process  of  sublimation.  In  some  works 
on  the  continent  it  is  never  sublimed,  but  meie^ 
inspissated  by  evaporation,  and  then  moulded  into 
the  shape  of  a  cone.  In  saying  that  the  consuoieiA 
preferred  the  Jbreign  sal-ammoniac,  I  do  not  OMaa 
that  this  was  on  account  of  its  quaUly,  because  it  is 
undoubtedly  more  impure  than  that  which  is  made 
at  home ;  it  was  its  price  which  gave  it  this  prepoiH 
derance. 

A  more  economical  process  than  the  one  alveadf 
described,  for  making  this  very  important  salt,  WM 
devised  some  years  ago.  This  consisted  in  decom.-. 
posing  the  impure  solution  of  carbonate  of  ammonia 
by  means  of  gypsum,  or  sulphate  of  lime ;  and  a. 
Mr.  Minish  of  Whitechapel  obtained  a  patent  fior 
the  discovery.  Perfectly  dry  sulphate  of  lime  oon« 
sists  of  one  proportional  of  lime,  or  oxide  of  caldum, 
26 '5+ one  proportional  of  sulphuric  acid  37*5,  and 
its  equivalent  number  is  64. 

In  conducting  the  patent  process,  the  rough 
spirit  as  it  is  called^  or  the  aqueous  product  of  the 
distillation  of  bones,  is  digested  upon  ground  plas«. 
ter  of  Paris ;  when,  in  consequence  of  a  double  de* 


ON    SAL-AMMONIAC. 


451 


composition,  carbonate  of  lime  is  formed,  which  pre- 
cipitates, and  sulphate  of  ammotiia,  which  remains 
in  the  solution.  The  fluid  containing  the  sulphate 
of  ammonia  is  then  poured  from  the  precipitate 
upon  a  definite  quantity  of  muriate  of  soda"  {com- 
mon salt),  when  another  change  takes  place,  which 
gives  sulphate  of  soda  and  muriate  of  ammonia ; 
and  these  are  then  treated  and  separated  as  the 
others,  by  sublimation. 

This  process  was  carried  on  for  several  years — 
till  the  term  for  which  the  patent  was  granted  ex- 
pired, when  the  proprietor  relinquished  the  concern, 
and  retired  from  business  with  an  ample  fortune, 
acquired  by  the  manufacture  of  sal-ammoniac, 
merely  in  consequence  of  the  great  superiority  of 
bis  process. 

Another  method  of  making  sal-ammoniac  was 
inTented  by  Dr.  Hector  Campbell,  which  consisted 
in  mixing  the  solutions  of  muriate  of  soda,  sulphate 
of  magnesia",  and  rough  carbonate  of  ammonia 
technically  called  bone  spirit.  This  process,  in  a 
theoretical  view  of  it,  appeared  likely  to  be  profita- 
ble, as  it  would  give,  if  the  decompositions  were 
complete,  three  valuable  products  for  sale,  vi^  sal- 
ammoniac,  carbonate  of  magnesia,  and  Glauber's 


"  Muriateof  soda,  in  solution,  consists  of  soda  29  S-|-muria- 
\\e  %c\i'M'o,  which  make;  its  oquiralpnt  number  64  ;  but  when 
desiccated  it  may  be  said  btimnsist  of  21^  sodium +33.5  of  chlo- 
rine, whicli  gives  its  equivalent  nombet  hb.h. 

"  Sulphate  of  mi^jneaia,  when  perfectly  dry,  consists  of  184 
ormaj^aosia  +37.^  of  suliihuric  acid,  and  its  equivalent  number 
i»56. 

2g2 


L 


452  ON   SAL-AMMONIAC. 

salt ;  but  I  have  reason  to  think  that  it  has  proved 
otherwise^  or  the  concern  would  not  have  been  al« 
together  relinquished*  I  have  also  some  doubt  as 
to  the  separation  of  the  muriatic  acid  from  the  com* 
mon  salt  by  this  mixture,  because  we  know  that  van* 
riate  of  soda  and  sulphate  of  magnesia  are  not  in^ 
compatible  salts»  for  they  are  constantly  found  toge- 
ther in  considerable  quantities  in  the  waters  of  the 
ocean. 

Much  has  been  ^aid  at  different  times  about  the 
liege  process  of  making  sal-ammoniac;  wbidi 
consists  in  mixing  small  sea  coal,  common  salt,  and 
the  soot  produced  from  pit  coal,  and  then  unitang 
these  into  a  paste  with  tempered  clay  and  water. 
The  mass  is  afterwards  formed  into  slabs  in  the 
form  of  flat  tiles,  and  these  are  then  placed  in  a  fur? 
tiace  with  bones,  Idd  stratum  isuper  stratum,  and 
the  product  of  the  combustion  collected  in  appro^ 
priated  chambers.  When  these  furnaces  are  set 
to  work,  they  are  generally  kept  burning  for  five  or 
six  months. 

This  appears  to  me  to  be  a  better  process  than 
that  of  mixing  the  ammonia  with  liquid  muriatic 
acid ;  but  I  am  inclined  to  think  it  is  too  tedious 
an  operation  ever  to  become  profitable  in  this 
country  '*.  Weber  states  that  the  soot  of  the  Dutch 
turf  yields  also  a  perfect  sal-ammoniac  by  sublima- 
tion.   The  Earl  of  Dundonald  advises  to  mix  fresh 


*'  An  ample  account  of  tiie  Liege  method  will  be  found  in 
ChaptaVs  Chemistry  applied  io  the  Arts,  together  with  an  ac- 
count of  the  manner  of  conducting  the  sublimation .  See  vfA.'w* 
page  178. 


ON  SAL-AMMONIAC.  433 

slacked  lime  with  ground  peat,  and  then  to  distill 
for  ammonia. 

In  the  year  1794,  Leiievre,  Pelletier,  D'Arcet, 
mnd  Giroud,  eminent  French  chemists,  were  em- 
ployed by  the  Committee  of  Public  Safety  in  Pbris, 
to  make  a  Report  on  the  divers  means  of  extracting 
aoda  from  sea  salt  with  advantage ;  and  they,  in 
their  account  of  that  process,  have  given  one  which' 
was  at  that  time  conducted  by  M.  Leblanc,  at  St. 
Denb  near  Paris,  for  the  manufacture  of  sal-am- 
moniac*^. 

His  method  consists  in  decomposing  muriate  of 
soda  by  sulphuric  acid  in  a  kind  of  reverberatory 
fomace,  the  floor  of  which  is  covered  with  lead ;  and 
as.  the  current  of  muriatic  gas  is  determined  into  an 
adjoining  leaden  chamber,  it  is  there,  at  the  same 
instant,  met  by  a  current  of  volatile  alkali,  produced 
from  a  variety  of  animal  matters,  which  they  burn 
in  three  cylinders  of  iron,  placed  in  a  furnace,  side 
by  side  of  each  other. 

.  In  this  process,  the  vapours  of  the  muriatic  salt 
are  condensed  in  the  leaden  chamber,  not  only  by 
^eir  combination  with  the  ammonia'',  but  also  by 
means  of  an  eolipile,  which  was  heated  by  the  same 

^  An  extract  from  this  Report  was  printed  in  the  Annales  de 
Chimie,  torn.  xix.  page  58. 

*'  If  the  stopper  be  taken  out  of  a  phial  of  muriatic  acid,  in 
tlie  presence  of  some  li(}uid  ammonia,  it  will  be  seen,  b^  ^he 
cloua  of  muriate  of  ammonia  in  vapour  which  will  appear  m  the 
■Imosphen*,  how  eager  these  gases  are  to  unite  to  form  the  new 
compound. 


454  QN  «AI.»AMMeKIAC. 

furaace  in  which  the  iroa  cylimlere  were  fixied  for 
the  combustion  of  the  animal  substances. 

The  decomposition  of  the  muriate  of  soda  was 
not,  however,  entirely  finished  in  this  operatioii»  be- 
cause the  sheet  of  lead  which  covered  the  floor  #C 
the  reverberatory  furnace  could  not,  without  m^ 
ing,  endure  a  degree  of  heat  sufficiently  strong  to 
effect  this  purpose.  The  operator  therefore  mows 
the  matter  into  a  third  reverberatoiy  furnace  pavied 
with  brickj  where  it  receives  a  degree  of  heat  8ii£> 
ficient  to  make  it  enter  into  fiision,  and  complele 
the  decomposition.  It  was  necessary  for  the  pr^ 
prietors  of  this  establishment  to  complete  the  de* 
composition  of  the  common  salt,  because  the  ecoi-' 
Bomy  of  their  process  consisted  in  the  employmeDt 
of  the  alkaline  residuum  for  the  production  of  ccf* 
stallized  soda. 

This  ingenious  method  of  making  sal^ammoome 
is  described  likewise  in  the  second  volume  of  the 
Journal  de  Physique  for  the  year  1794,  p.  134,  md 
it  is  there  accompanied  with  a  copper-plate  en* 
graving  of  the  ground-plan  of  the  furnaces  and  other 
apparatus  employed  in  the  process.  This  i^paratw 
is  so  very  different  from  any  thing  which  I  haw 
seen  in  this  country,  and  at  the  same  time  is  so  well 
contrived  for  the  purpose,  that  I  have  thought  it 
worth  while  to  copy  it  and  have  it  engraved^  to 
accompany  this  Essays- 
There  is,  however,  a  mode  of  making  sal-ammo* 


^  See  Plate  23  at  page  437  of  this  volume. 


OV  SAL-AMMOMAC.  4o5 

niac,  which  I  conceive  would  be  more  economical 
than  any  of  those  already  mentioned.  It  con^sts 
in  the  employment  of  the  bittern  of  the  salt-works, 
or  the  mother-waters  which  remain  after  the  ex- 
traction of  common  salt  from  sea  water.  This  is 
not  a  mere  theoretical  notion,  for  the  process  has 
more  than  once  been  acted  upon,  and  at  this  time 
large  quantities  of  sal-ammoniac  are  actually  made 
according  to  this  principle  in  some  parts  of  Scot- 
land. 

The  desire  of  making  this  valuable  and  economi- 
cal process  for  preparing  muriate  of  ammonia  from 
the  bittern  of  the  salt-pans  more  generally  known, 
was  the  motive  that  induced  me  to  render  the  ma- 
nufacture  of  sal-ammoniac  one  of  the  subjects  of 
these  Essays. 

Ttie  preparation  of  this  important  salt  by  means 
of  bittern  is  not,  as  I  have  said,  a  new  process,  for 
I  recollect  reading  an  account  of  it  many  years  ago 
in  one  of  the  volumes  of  the  Annates  de  Chimie**, 
and  in  other  works ;  but  knowing  the  Board  of 
Excise  in  England  would  neither  allow  the  use  of 
bittern,  nor  even  the  burnt  pickings  of  the  salt-pans, 
free  of  excise  duty,  I  imagined  this  to  he  one  of 
those  processes  which  are  interdicted  by  the  high 
price  of  the  materials,  till  an  accidental  circumstance 
which  occurred  a  few  years  ago  recalled  my  atten- 
tion to  the  bubject  in  a  very  particular  manner. 


'■>  See  .innalei  tie  C'ftimie,  Wm,  xs.  pngt  IS6. 


456  ON  8AL-?AMMOMIAC« 

Mr.  Astley  of  the  town  of  BorrowstonesB  near 
Leith,  who  had  taken  out  a  patent  for  the  oianufao 
ture  of  sal-ammoniac  by  combustion,  in  which  ht 
proposed  to  burn  bones,  blood^,  and  other  animal 
matters,  with  the  bittern,  proceeded  by  due  conne 
of  law  against  a  gentleman  of  the  same  town  for 
having  infringed  his  patent,  and  the  cause  came 
to  be  tried  before  the  Lords  of  Session  in  Scotland. 
The  question,  however,  not  having  been  determined 
by  the  Court,  it  was  agreed  between  the  parties  to 
defer  final  judgement  until  the  opinions  of  soaie 
practical  chemists  in  London  should  be  obtained  oa 
the  subject;  and  it  was  during  my  examinatidd 
before  the  Commissioner  appointed  by  the.  Lords 
of  Session  to  take  our  report,  that  I  first  obtained 
the  information  that  the  Board  of  Excise  allows  the 
inhabitants  of  Scotland  the  bittern  of  the  salt-works 
free  of  duty. 

On  acquiring  a  knowledge  of  this  fact,  a  questioB 
immediately  occurred — If  the  inhabitants  of  one 
part  of  the  empire  are  allowed  an  article  which  -is 
capable  of  being  used  in  our  manufactories  duty 
free,  why  should  not  the  same  indulgence  be  uni* 
versal  in  England  and  Ireland,  as  well  as-  in  Scot^ 
land  ? 

Reflecting  still  more  and  more  on  this  subject, 
and  knowing  that  the  riches  of  a  country  depend 
in  a  great  measure  on  its  producing  within  itself 

^  Dr.  Thomson  says,  that  if  the  fibrous  part  of  blood  be  left 
in  wvXct  it  soon  putrifies,  and  then  yields  more  ammonia  than 
any  other  animal  substance. 


ON  SAL-AMMONIAC.  457 

most  of  the  articles  required  for  its  own  consump- 
tion, I  think  it  right  to  make  this  circumstance 
more  generally  known ;  in  the  hope  that  some  com- 
petent person,  possessing  tiie  advantages  of  capital 
and  a  favourable  locality  of  situation,  would  petition 
the  legislature  for  leave  to  commence  such  an  under- 
taking, and  thus  relieve  the  country  from  the  neces- 
sity of  sending  into  another  quarter  of  the  globe  for 
a  supply  of  this  valuable  and  necessary  commodity. 

If  a  company  of  persons  accustomed  to  the  manu- 
facture of  sal-ammoniac  was  established  in  the 
neighbourhood  of  any  of  the  salt-works  in  Cheshire, 
or  near  the  salt-pits  of  Droilwich  in  Worcestershire, 
and  could  obtain  permission  from  Government  to 
use  the  bittern  which  is  produced  at  either  of  those 
establishments,  and  which  at  present  is  thrown  away 
as  a  useless  residuum,  I  am  certain  that  such  a  com- 
pany would  be  enabled  to  afford  the  article  in  ques- 
tion much  cheiiper  than  the  English  sal-ammoniac 
has  been  sold  for  many  years  past,  and  at  a  rate 
which  would  effectually  prevent  the  importation  of 
ammoniacal  salt  from  any  part  of  the  East.  There 
are  considerable  salt-works  in  the  Isle  of  Wight, 
and  on  the  opposite  coast  at  Lymington  in  Hamp- 
shire ;  but  at  both  th(.-se  establishments  the  salt  is 
procured  by  the  evaporation  of  sea  water. 

About  a  century  ago,  a  work  of  the  kind  which 
I  have  here  recommended,  was  established  by  one 
Goodwin  a  cheraiat  of  London  *,  in  which  he  pro- 


"  iHttilulei  of  Etfitrimental  Chrmistrg,  2  volur 
printed  by  Nounc, Luiidon  1759,  voL  i.  ))iige  34/. 


468  OK  ftAL-AMMONIAC» 

jduced  sd-ammoniac  by  mixiog  the  bittern  of 
water  with  putrid  urine ;  but  where  thb  manofiMS- 
lory  was  situated  I  have  not  been  able  to  learn. 
Beum^  formed  a  similar  establbhment  in  France 
where  he  decomposed  the  muriate  of  magnesia  con- 
tained in  the  bittern  of  sea  water,  by  means  of  a 
rough  ammoniacal  liquor  procured  from  the  distil* 
lation  of  animal  substances. 

I  find  also,  from  the  testimony  of  Mn  Dossier 
that  a  like  establishment  was  formed  about  the  year 
1740,  under  the  sanction  of  a  patent « ;  but  he  doci 
not  inform  us  either  of  the  names  of  the  party,  or 
of  the  place  where  their  operations  were  conducted^ 
though  it  appears  from  the  form  of  his  narrative^ 
that  both  these  establishments  were  dissolved  in 
consequence  of  their  great  distance  from  Ae  saltr 
works  whence  the  bittern  was  produced,  and  the 
inevitable  expense  of  the  remote  conveyance  of  an 
article  of  so  much  bulk  and  little  value*  Tliese 
obstacles  would  not  however  intervene,  were  a  mah 
nufactory  to  be  established,  as  I  propose,  in  the  im- 
mediate vicinity  of  a  salt-work ;  because  bones  and 
other  refuse  animal  matter  can  be  obtiuned  any 
where. 

The  chrysalides  of  silk-worms  are  very  produ^ 
tive  of  carbonate  of  ammonia.  Hence  several  di- 
stricts in  Italy,  and  other  parts  of  the  continent, 
might  be  found  where  a  manufacture  of  thb  alkali 
could  be  established  with  advantage. 

It  still  however  appears  to  me,  as  I  suggested 


to 


Instiiiites  of  Experimental  Oienmtry,  vol.  i.  page  348. 


ON  SAL-AMMONIAC.  459 

several  years  ago  in  another  publication  *^,  that  the 
best  situation  for  a  manufacture  of  ammonia  is  oh 
the  sea  coast,  where  [nlchards,  herrings,  or  the  dog« 
fish,  arrive  in  such  immense  shoals  as  to  be  perio* 
dically  employed  in  manure  for  land.  The  dog- 
fish (the  Squalus  canicula  of  Linnaeus)  is  caught 
mtt  along  the  coast  of  Scotland  from  Peterhead  to 
Bamff.  They  generally  follow  the  herrings,  and 
night  probably  be  caught  wherever  shoals  of  her- 
rings are  found.  The  value  to  the  fishers  is  in  the 
liver,  of  which  they  make  oil:  therefore,  the  carcase, 
sfter  extracting  the  liver,  is  sold  for  manure.  They 
are  caught  with  hand  lines,  and  sometimes  in  such 
quantities  that  the  boats  come  in  as  deeply  loaded 
iur  they  can  swim.  The  dog-fish  is  usually  from 
80  inches  to  36  inches  in  length,  and  they  are  sold, 
ilter  the  extraction  of  the  liver,  at  2^.  6e£  per  bun* 
Ared,  consisting  of  140  fish,  and  seven  of  these 
hundreds  weigh  about  a  ton.  By  proper  manage- 
ment, the  body  of  this  fish  would  certainly  prove  a 
Tery  profitable  article  for  the  production  of  am« 
fiionia. 

At  Bamberg,  in  the  circle  of  Franconia,  the  Ger- 
mans have  long  been  accustomed  tq  boil  the  sedi- 
ment of  the  salt-pans  with  stale  urine,  and  sell  it 
eheap  for  making  sal*ammoniac.  A  similar  kind  of 
nit  is  still  prepared  in  the  neighbourhood  of  Vienna. 
In  several  other  parts  of  Germany,  and  particularly 
in  the  vicinity  of  Gottenburgh,  ammonia  is  pre- 


^  See  Chemical  Catechitim,  c\wp,  vi.  p.  137. 


460  ON  SAL-AM  MOKI AC. 

pared  from  the  dregs  which  remmn  after  the  ex« 
pression  of  train  oil.  Why  might  not  the  .  whale 
blubber  be  employed  for  the  distillation  of  .am? 
monia  ?  Means  might  be  devised  for  correcting 
its  offensive  smell,  and  rendering  it  very  productive 
of  volatile  alkali. 

The  ingenious  Mr.  Dossie,  already  mentioned^ 
who  was  a  manufacturing  chemist  of  the  la9t  cent 
tury,  and  who  had  the  honour  of  being  one  of  the 
first  English  writers  who  undertook,  with  a  noble 
superiority  to  all  considerations  of  private  advan* 
tage,  to  describe  and  elucidate  many  of  the  most 
important  chemical  processes  without  reserve^  jias, 
however,  fallen  into  a  considerable  error  respecting 
the  use  of  bittern ;  an  error  which  has  probably 
misled  many,  and  may  have  been  the  occasion  of 
deterring  some  individuals  from  establishing  the 
identical  mode  of  making  sal-ammoniac  which  I 
am  now  so  anxious  to  explain  and  recommend.  In 
order  to  correct  this  mistake,  I  shall  copy  what  this 
respectable  writer  has  advanced  upon  the  subject  *\ 
and  shall  then  endeavour  to  explain  how  this  mis- 
conception has  arisen. 

He  sayb,  that  ^*  in  the  English  manufactures  of  $al« 
'*  ammoniac,  the.  vitriolic  ammoniacal  salt,  which 
'*  greatly  resembles  the  true  sal-ammoniac,  in  itsap-. 
*'  pearances  and  qualities,  has  generally  been  pro- 
**  duced  instead  of  the  true,  as  the  sal  cathariicum 

*•  Mr.  Dossie  was  author,  not  only  of  Th«i  Chetnivtd  JntttU 
tutes  already  mentioned,  but  also  of  a  very  useful  work  entitled 

The  Elabofuloru  laid  open^  &.c.  octavo,  London  1/58. 


cc 


ON  9AL*AMM0NIAC;  4Gt 

••  amarum^  a  vitriolict>'terrene  neutral  salt,  con- 
'*  tained  in  the  bittern  or  mothers,  left  after  the  ex-' 
'*  traction  of  the  salt  from  se&-water,  was  employed 
^  for  furnishing  the  acid.** 

**  The  reason  of  this  substitution  of  the  vitriolic 
*'  acid  for  the  other,  was  owing  to  this  circumstance, 
**  that  the  spirit  of  salt  is  not  found  naturally  in  any 
*'  other  state  than  combined  with  the  natron  in  the 
''  form  of  sea  salt ;  which  natron  attracting  the  acid 
with  a  power  superior  to  that  of  the  volatile  al-^ 
kaline  salt,  such  acid  could  not  be  brought  to 
combine  with  the  volatile  salt,  without  some  pre- 
vious analysis  or  separation  were  made  of  it  from 
^  that  stronger  alkali.  This  is  indeed  practicable, 
**  by  means  of  distillation  with  oil  of  vitriol ;  or  by 
*'  burning  the  animal  substances,  designed  to  pro- 
*'  duce  the  volatile  salt,  together  with  the  sea  salt; 
*'  in  which  case  the  spirit  being  separated,  com- 
•'  bines  with  the  volatile  alkali  as  it  is  formed  \ti  the 
*'  burning  matter,  and  the  combined  elements  sub- 
"  lime  in  the  form  of  the  true  sal-ammoniac. 

**  But  such  a  previous  distillation  of  the  spirit  is 
*'  laborious  and  expensive;  and  the  burning  the  ma- 
''  terials  and  salts  together,  as  this  is  only  to  be 
'*  done  with  an  open  fire,  and  ndt  in  a  close  vessel, 
•*  (the  separation  of  the  spirit  not  being  to  be  ef- 
fected but  on  the  principle  of  combustion,)  oc- 
casions the  dissipation  of  a  great  part  of  the  salt 
produced.  Also,  the  principle  of  combustion  re- 
quiring solid  materials  to  be  employed  to  afford 
*'  the  volatile  salt,  this  excludes  the  use  of  urine.** 


«t 

cc 

fC 


462  as  SAL-AMMONIAC. 

The  conclusion  which  Mr.  Doissie  draws  from 
what  he  has  said,  viz.  that  pure  sal-ammoniac  can- 
not be  made  by  the  admixture  of  carbonate  of  am* 
monia  with  bittern,  appears  to  have  been  occasion- 
ed by  his  supposing  that  sea-water  condsts  only  of 
muriate  of  soda  and  sulphate  of  magnesia;  wh^'eas, 
a  large  portion  of  magnesian  muriate  is  also  con* 
tained  in  it.  This  becomes  decomposed  as  soon 
as  it  is  added  to  the  ammoniacal  liquor,  and  the  re- 
sult, as  for  as  the  muriate  of  magnesia  is  concemect 
is  the  formation  of  a  true  sal-ammoniac. 

Before  I  proceed,  it  may  be  observed  that  a  con- 
siderable degree  of  practical  experience  is  necesaaiy 
in  order  to  enable  a  manufacturer  to  produce  a  neat 
article  of  sal-ammoniac  by  this  process  of  sublima- 
tion. With  a  moderate  heat  it  attaches  itself  to  tlie 
surface  of  the  vessel  in  a  loose  spongy  state,  and  is 
then  called  powers  of  sal-ammoniac ;  whereas,  if 
this  volatile  salt  be  raised  by  a  strong  fire,  a  soGd 
sublimate  is  obtained ;  but  if  the  heat  be  too  in- 
tense, part  of  the  product  is  in  danger  of  being  dis- 
sipated and  lost. 

The  extraction  of  the  ammonia  on  the  principle 
of  combustion  adverted  to  by  Mr.  Dossie,  must 
doubtless  arise  from  the  necessity  of  a  constant 
supply  of  fresh  atmospheric  air ;  for  I  recollect  Dr. 
Woodhouse  of  Pennsylvania  asserts,  that  if  he  luted 
his  stills  he  could  never  obtain  the  proper  quantity 
of  ammonia;  but  when  he  operated  without  lute  he 
procured  five  times  as  much  of  this  alkali  from  any 
determinate  quantity  of  bones  as  he  otherwise  could. 


ON  SAL-AMMONIAC.  46$ 

When  urine  is  employed  for  the  production  of 
ammonia,  it  is  necessary  to  keep  it  till  it  becomes 
putrid,  this  alkali  being  one  of  the  products  of  pu« 
trefaction.  In  summer  cne  week  will  generally  suf- 
fice, but  in  cold  weather  it  ought  to  be  kept  three 
weeks  or  a  month. 

It  is  not,  however,  very  surprising  that  Mr. 
Doasie  should  have  fallen  into  the  error  respecting 
the  bittern  just  noticed;  for  even  Fourcroy,  wlio 
died  but  lately,  overlooked  the  magnesian  muriate,^ 
^sA  describes  the  waters  of  the  ocean  as  contdning 
only  **  muriate  of  soda,  sulphate  of  magnesia,  sul-« 
phate  of  lime,  and  much  extractive  matter  ^J* 

On  the  contrary,  Bergman^s  analysis  of  a  sample 
of  water  taken  up  at  the  depth  of  sixty  fathoms^. 
shows  no  portion  of  magnesian  sulphate.  The 
anidysis  of  sea- water  by  Liavoisier,  which  gives  1958 
l^arts  of  solid  matter  of  various  kinds  in  10,000. 
garts  of  sea  water,  is  as  under : 

1375  muriate  of  soda, 
256  muriate  of  lime  and  magnesia, 
156  muriate  of  magnesia, 

84  sulphate  of  magnesia  and  soda, 

87  lime. 


1958 


TTie  latest  analysis    which   can    be   depended 
upon,  and  perhaps  the  best,  is  that  by  the  late 

•  Fourcroy's  System  of  Chemical  Knowledge,  vol.  iv.  p.  409. 


464  ON  SAL-AMMONIAC. 

Dr.  Murray  ^,  who  obtsdned  by  the  evaporation'  of 
a  pint  of  sea  water. 

Common  salt  ISOii  graini 

Muriate  of  magnesia  23i) 

Sulphate  of  magnesia  15.5 

•    Sulphate  of  lime  7. 1 


226.1 

By  this  estimate  U  appears  that  the  proportioQ 
of  muriate  of  lime,  and  muriate  of  magnesia,  in  sea- 
water  is  considerable ;  I  am,  therefore,  fully  justi- 
fied in  recommending  the  use  of  bittern  for  the 
preparation  of  the  ammoniacal  muriate,  and  the 
production  of  magnesia. 

Another  advantage  will  also  result  from  the  use 
of  this  refuse  article,  which  is  this,  that  the  sulphate 
of  magnesia  may  also  be  rendered  efficient  towards 
the  production  of  sal-antmoniac ;  inasmuch  as  it 
will  decompose  the  liquid  carbonate  of  ammonia, 
and  form  ammoniacal  sulphate,  which,  by  the  ad- 
dition of  common  salt,  may  at  any  time  be  con- 
verted to  the  true  anlmoniacal  salt  of  which  we  are 
now  treating.  If  the  process  be  thus  improved  and 
carried  to  its  full  extent,  the  products  for  sale  will 
be  sal-ammoniac,  carbonate  of  magnesia,  and  Glau- 
ber^s  salt. 

It  is  important  to  remark,  that  the  mixture  ot  a 
proportion  of  sulphate  of  ammonia  with  the  true  sal- 


^  TramacHons  of  the  Royal  Sociehf  of  Edinburgh,  vol.  viiL 
p.  205, 


ON  SAL-AMMONIAC, 


465 

aihiiiohiac  will,  for  many  purposes,  be  no  injiiiy :  for 
instance,  the  ammoniacaJ  sulphate  is  well  adapted  to 
the  soldering  of  metals,  and  equally  applicable  with 
the  muriate  of  that  alkali  for  the  preparation  of  liqaid 
ammonia,  although  it  is  not  quite  so  productive  of 
alkali. 

Some  further  information  on  the  affinities  of  am- 
monia and  on  several  of  its  compounds,  may  be  ob- 
tained from  Lewis's  edition  of  Neumann's  Clicfnis- 
try,  vol.  i.  pages  336 — 3.53  ;  Fourcroy's  System  of 
Chemical  Knowledge,  vol.  ii.  pages  323 — 354,  and 
vol.  iii.  pages  272 — 284  ;  in  several  of  the  volumes 
of  the  Annales  de  Chimie ;  and  in  the  Quarterly 
Journal  of  Science,  vol.  iv.  page  268,  vol.  v.  pages 
74  and  368,  vol.  ix.  page  405,  vol.  xiii.  page  226, 
and  vol.  xiv.  page  203. 

On  the  nature  and  properties,  and  on  the  forma- 
Uon  and  decomposition  of  muriate  of  aminoBJa,  Or 
sal-ammonlnc,  the  Annales  de  Chimie  may  be  con- 
sulted, viz.  Weatrumb  on  its  decomposition  by  mag- 
nesia and  carbonate  of  magnesia,  vol.  ii.  pages  1 18 
— 136 ;  Vogler  on  its  effects  with  madder  In  dyeing 
Knen  and  cotton,  vol.  iv.  pages  115  and  144  >  Dr. 
Btflgden  on  its  use  in  freezing  water,  page  238  ; 
on  its  analysis,  vol,  "xiv.  page  210  ;  Hassenfratz  on 
its  speci&c  gravity,  vol.  xxviii.  page  13  ;  Fourcroy 
and  Vauquelin  on  the  change  in  the  form  of  its 
crystal  by  its  union  with  urea,  vol.  xxi.  page  67, 
and  vok  xxxii.  page  130;  on  its  extraction  from 
urine,  page  162  ;  Mons.  Virey  on  its  formation  in 
volcanoes,  vol.  xxxvi.  page  290  ;  Vauquelin  on  its 

VOL.   11.  2  H 


k 


466  ON  SAL-AMMONIAC. 

existence  in  tobacco,  vol.  bun.  ptge  153 ;  Bera^Vi 
on  its  composition,  vol.  Ixxix.  page  233,  aodiol. 
Ixxid.  pages  5— -13. 

Although  I  have  given  so  man3r  processes  for 
making  muriate  of  ammonia,  I  must  not  omit'  to 
advert  to  another  source  from  whence  thb  sah  has 
of  late  years  been  obtained.  By  the  disUUatiob  of 
common  pit^oal  to  procure  carburetted  hydrogn 
gas  for  the  purposes  of  illumination,  a  oonudefafale 
quantity  of  ammoniacal  liquor  is  obtuned  in  te 
condensing  vessel.  This  liquor,  which  contains  a 
portion  of  carbonate  and  sulphate  of  ammonia  in 
solution,  is  sold  to  the  makers  of  sal-ammonias^ 
who  obtain  the  salt  from  it  by  the  following  pro- 
cess. It  is  first  treated  with  sulphate  of  lime^  sflail 
afterwards  with  sulphuric  add,  which  is  adddi 
gradually  until  the  whole  of  the  carbonate  ol  am- 
monia is  decomposed,  and  a  sulphate  of  ammonia 
formed.  By  subsequent  evaporation  of  the  supay 
fluous  liquor  the  sulphate  of  ammonia  is  obtained 
in  crystals.  At  other  times  common  salt  is  added 
to  the  solution  of  sulphate  of  ammonia ;  and  this, 
by  the  play  of  chemical  affinities^  produces  two  new 
salts,  viz.  sulphate  of  soda,  and  muriate  of  am- 
monia. The  liquor  containing  these  two  salts  is 
then  reduced  in  quantity,  by  evaporation^  to  that 
point  at  which  it  is  known  by  experience  that  the 
sulphate  of  soda  will  sepamte  itself  on  codling. 
When  this  salt  has  been  removed,  the  remaining 
liquor  is  then  evaporated  till  the  muriate  of  am- 
monia will  crystallize,  as  has  already  been  described 


ON  MAUAMMONIAC. 


4fl7 


at  p«ge  449.  After  tills  the  muriate  of  ammonia  is 
dried  carefully,  and  tlien  by  the  usual  process  of 
sublimation,  it  is  formed  into  cakes  of  the  true  sid- 
amnMHiiftc.  I  refrain  from  stating  the  [uoduct  of 
muriate  of  ammonia  that  may  be  obtained  fron 
any  given  quantity  of  the  ammoniacal  liquor,  as 
there  is  perhaps  no  article  of  commerce  that  variei 
more  in  quality  than  this  residual  liquor.  At  the 
large  gas  works  in  Worsliip  Street.  London,  where 
every  thing  is  conducted  with  great  judgement  and 
ability,  1  have  understood  that  care  is  taken  to  pre- 
ser\'e  all  the  ammoniacal  liquor,  and  endeavours  are 
made  to  sell  it  of  one  uniform  quality. 

Having  thus  entered  rather  fully  into  the  merits 
of  this  subject,  and  having  especially  explained  the 
process  of  making  sal-ammoniac  by  means  of  bit- 
tern, I  have  now  only  to  remark,  that  I  have  no 
doubt,  when  a  proper  application  is  made  to  the  le- 
gislature to  release  the  bittern  of  the  salt-works 
from  the  cognisance  of  the  excise  when  employed 
for  the  manufacture  of  sal-ammoniac,  that  the 
people  of  England  will  be  put  in  as  favourable  a 
situation  in  this  respect  as  those  of  Scotland ;  the 
first  object  of  every  British  senator,  next  to  that  of 
preser\'ing  the  tranquillity  of  the  state,  being  to 
strengthen  the  resources  and  encourage  the  manu- 
factures of  the  country. 

Ormus,  the  celebrated  depot  for  the  sale  of  the 

merchandize  of  the  ancients,  and  the  grand  capital 

of  an  Arab  monarch,  is  in  itself  the  most  parched 

and  barren  spot  in  the  world,  where  the  people  re- 

2  II  2 


408  O^  SAL-AMMOKIAIC. 

eeived  even  the  water  they  drank  from  a  neigfaboiu^ 
ing  country :  but  it  became  rich  by  the  cultivalioa 
of  trade,  and  the  commerce  of  this  otherwise^  nu- 
serable  island  made  it  the  envy  of  the  surrounding 
nations  "• 

Long  has  the  island  of  Britain  in  like  manner 
enjoyed  the  blessings  and  luxuries  which  arise  from 
an  extended  trade ;  and  though  we  are  now  in  the 
possession  of  the  greatest  part  of  the  traffic  of  the 
world,  we  must  not  expect  to  preserve  this  piood 
pre-eminence,  unless  the  Government  determine  to 
pay  the  most  sedulous  attention  to  our  most  mi- 
nute interests  as  a  manufacturing  and  commordsl 
people. 


• » 


'^  See  Canpben'8  Poit<ic0l  Surveff  of  Great  BrUm^tfomf^^ 
ro\,  I  page  36; 


ESSAY  XV. 


ON 


THE  MANUFACTURE  OF 


EDGE  TOOLS. 


ESSAY  XV. 


ON 


THE  MANUFACTURE  OF 
EDGE  TOOLS. 


1  HE  history  of  the  invention  of  edge  tools  is  in- 
volved in  much  obscurity.  The  materials  employed 
by  the  ancients  for  making  them  were  various ;  but 
the  metal  in  general  use  in  modern  times  and 
among  civilized  nations  for  the  fabrication  of  such 
instruments,  is  iron ;  though  this  metal  varies  in  its 
nature,  and  is  differently  prepared  according  to  the 
purposes  to  which  the  instrument  or  weapon  is  ap* 
plicable. 

Although  iron  was  known  befare  the  Deluge, 
yet  there  is  reason  to  believe  tbc^t  the  method  of 
making  it  was  afterwards  lost.  Tubalcaio,  wbo  lived 
nearly  four  thousand  years  before  the  commence- 
ment of  the  Christian  aera,  was  "  an  instructor  of 
every  artificer  in  brass  and  iron  *  ;**  and  we  are  told 
that  Abraham  took  a  knife  to  slay  his  son  Isaac  *. 

•   Genesis  iv.22.  •  Ibid.  xxii.  10. 


472  ON  THE  MANUFACTURE 

In  these  early  times  mention  is  also  made  of 
shears^  and  of  the  shearing  of  sheep';  and  yet 
many  of  the  ancient  nations  knew  nothing  of  iroo, 
but  used  stones,^  flints,  the  horns  and  bones  of  va- 
rious animals,  the  bones  and  shells  of  fish,  reeds, 
and  thorns,  for  every  purpose  in  which  the  modemi 
now  use  edge  tools  of  iron  and  steel  \ 

Cutting  instruments  of  stone  are  frequently  fodnd 
10  various  parts  of  Asia  and  Europe,  particular^ 
in  the  tombs  of  the  andent  inhabitants  of  Peru*; 
and  in  Carmania,  a  province  of  Persia,  hanunen 
frequently  occur  which  are  made  entirely  of  stone. 
These  are  known  by  the  name  of  Cerauma,  or 
thunder-stones,  and  are  preserved  in  some  cabinets., 
They  are  perforated  for  the  reception  of  handles,  in 
the  place  most  proper  for  recdving  them,  so  as  to 
leave  no  doubt  of  their  having  been  intended  fill' 
hammers,  and  used  in  the  same  way  as  we  empkj 
such  implements  at  the  present  day  \ 

There  is  a  very  circumstantial  account  of  the 
stone  weapons  of  the  andents,  accompanied  wiih 
several  copper-plate  engravings,  in  Dr.  Woodward's 
History  of  Fossils.  The  same  writer  informs  us 
that  Captain  Dampier  found  such  implements  still 
in  use  at  Guam,  one  of  the  Ladrone  Islands,  and 
also  in  Nova-Britannia,  an  island  lying  south  of 


'  Genesis  xxxi.  19.  also  xxxriii.  \2,  13. 

*  Goguet'8  Origin  of  Laws,  ^c.  vol.  i.  page  140. 

^  Ihui.  vol.  i.  page  156. 

^  Agricola  De  Natura  Fossilium,  lib.  v.  cap.  13.  pag.  262 


OF  EDGE  TOOLS.  473 

the  equator  und  the  furthest  to  t)ie  east  of  any  then 
known '. 

Herodotus,  in  describing  the  ceremonies  wltich 
the  Arabians  observe  in  making  alliances,  suys,  that 
"  OR  these  occasions  some  one  who  is  connected 
with  both  parties  stands  betwixt  them,  and  with  a 
sharp  stone  opens  a  vein  of  the  hand  of  those  who 
are  about  to  contract.  He  then  takes  a  piece  of 
the  vest  of  each  person  and  dips  it  in  their  blood  •. " 

The  ancient  embaliners  of  Egypt  were  in  the 
habit  of  using  an  Ethiopian  stone  for  opening  the 
dead  bodies,  in  order  to  take  out  the  bowels  ' ;  and 
it  may  be  presumed,  from  its  being  the  practice  to 
circumcise  with  a  sharp  flint'",  that  edge  tools  of 
iron,  if  they  were  known,  were  not  very  common 
among  any  of  the  primitive  nations. 

Heaiod,  who  lived  probably  a  thousand  years 
before  the  time  of  Christ,  says  plainly,  that  "  the 
plough-share  was  made  with  a  species  of  very  hard 
oak " ;  and  from  his  manner  of  describing  the 
ploughs  that  were  then  employed,  there  is  no  reason 
to  suppose  that  any  iron  was  used  in  constructing 
them. 


'  Woodward's  Uitlon/  of  FouiU,  oclavo,  London  1/28, 
page  40. 

■  Beloe's  Herodottu,  book  iii.  §  8. 

•  HerodotiM,  lib.  ii.  n.  86.  Goguct's  Origin  of  Lattt,  vol.  i. 
puge  198. 

'<•  "  Then  Zippomli  look  a  sharp  stone,"  &c.  Etodvi  w.  2h. 

"   Hesiod.  Oper.  eil>i«,vcr.  436.  Gogucfs  Ur/^in  o/taiii, 

tol.  ii.  p.  m5. 


474  ON   TRB  "BlANUFACtURE 

Tlie  following  is  a  modern  trandation  of  the 
passage  to  which  I  allude : 

"  If  hill  or  field  supply  un  ilex  bought 
Of  bending  6gare  like  tiie  downwani  pkmgh, 
Benr  it  away  ^  this  dinaUe  rematna, 
U'liile  thy  .strong  steers  in  ridges  cleave  the  plains ; 
If  with  firm  nails  thy  artists  join  the  whole. 
Affix  the  share-beam^  and  adapt  the  pole  ^*.'* 

Dr.  Kinvan,  the  late  president  of  the  Royal  Irish 
Academy,  who  had  travelled  much  on  the  conti- 
nent of  Europe,  used  to  relate,  when  apeaking  of 
the  dilBcuIty  of  introducing  improvements  in  the 
arts  and  manufactures,  and  of  the  prejudices  enter- 
tained for  old  practices,  that,  in  Normandy,  the 
farmers  had  heen  so  long  accustomed  to  the  use  of 
ploughs  whose  shares  were  made  entirely  of  wood, 
that  they  could  not  be  prevailed  on  to  make  .trial 
of  those  with  irony — that  they  considered  them  to 
be  an  i3le  and  useless  innovation  on  the  long  esta- 
blished practices  of  their  ancestors ;  and  that  they 
carried  these  prejudices  so  far  as  to  force  the  Go- 
vernment to  issue  an  edict  on  the  subject.  And 
even  to  the  last,  they  were  so  obstinate  in  their  at- 
tachment to  plough-shares  of  wood,  that  a  tumul- 
tuous opposition  was  made  to  the  enforcement  of 
the  edict,  which  for  a  short  time  threatened  a  re- 
bellion in  the  province. 

On  the  arrival  of  the  Saxons  in  Great  Britain, 
our  ancestors  were  in  as  low  a  state  of  civilization. 


'•  Kltoirs  Translation  o/Hesiod't  IVorks  and  Days^  line  586 
—591. 


OF    EDGE  TOOLS.  4?^ 

One  of  their  laws  enacts,  that  no  man  should  un- 
dertake to  guide  a  plough  who  could  not  make  one, 
and  that  the  cords  with  whicl]  it  is  drawn  should 
be  formed  of  twisted  willows  ". 

We  have  no  testimony  that  Moses  made  use  of 
iron  in  any  part  of  the  tabernacle  which  was  pre- 
pared in  the  wilderness ;  neither  have  we  any  evi- 
dence that  Solomon  employed  that  metal  in  the:ton- 
Btruction  of  the  Temple  at  Jerusalem  ";  though,  in 
times  antecedent  to  these  periods,  they  made  iron 
axes  for  hewing  wood  ",  and  tools  of  iron  for  cut- 
ting stones  ". 

It  was  probably  the  difficulty  which  the  Hebrews 
found  in  making  iron,  and  the  consequent  scarcity 
of  that  metal,  which  occasioned  its  not  being  em- 
ployed for  purposes  of  building,  and  it  was  perhaps 
of  too  great  value  to  be  brought  into  common  use 
in  those  remote  times ;  a  conjecture  which  seems  to 
be  warranted  by  the  language  of  their  great  law- 
giver himself,  who  tells  the  people  in  his  description 
of  Palestine,  that  it  is  "  a  land  whose  stones  are 
iron,  and  out  of  whose  hills  they  may  dig  brass  ".'* 

A  few  centuries  after  this  period.  Homer  de- 
scribes Achilles  as  offering  a  large  quoit  of  iron  for 


"   Lfges  IValticar,  |tage  283. 

"  See  Goguel,  vol.  i.  page  ICl, 

II  ••  When  It  noa  goeth  into  the  wood  witii  htx  neif^hbour. 
hew  wood,  and  the  hra<I  slippeth  from  the  helvp,"  &c.     Dcute-    . 
toTwtmy  xix.  5.  In  the  original  Hebrew  il  is,  "  the  iron  f,l\}i\Kt)i 
from  the  wood"  as  may  i>e  seen  in  the  margin. 

'*  DcuUron-img  x\y\i.$.  ''    Ibid,  vUilt. 


476  ON  TH£  MAKUFACTURE 

one  of  the  prizes  at  the  games  instituted  in  honoar 
of  Pfttfoclus ;  from  whence  it  would  appear  that  dus 
metal  was  still  an  artide  of  considerable  value. 

''  Hien  hurl'd  the  hero,  thundering  on  the  ground 
A  maas  of  iron,  (an  enonnous  round,) 
Whose  weight  and  size  the  arding  Greeks  admire. 
Rude  from  the  furnace,  and  but  shaped  by  fire. 
Let  him  whose  might  can  hurl  this  bowl,  arise. 
Who  furthest  hurls  it,  take  it  as  his  (vize  **.** 

Madame  Dacier  on  this  passage  remarks^  "  It 
must  be  rememberedt  that  in  tiiose  times  tram  was 
very  scarce ;  and  a  sure  sign  of  this  scard^  b,  tlMt 
their  arms  were  usually  of  brass."* 

If  any  kind  of  edge  tools  of  iron  were  ia  use  at 
thb  period,  their  employment  must  have  been  qoii* 
fined  to  but  few  individuals;  for  several  andent  au- 
thors assert  tiiat  Dsdalud,  the  Greek  architect  fAo 
flourished  in  the  age  immediately  succeeding^  that 
in  which  the  temple  was  built,  knew  nothing  of  the 
saw.  The  invention  of  this  instrument  they  aacribe 
to  the  nephew  of  Deedalus*  who,  as  they  say,  hav- 
ing accidentally  met  mth  the  jaw  of  a  serpent  which 
he  used  with  success  to  divide  a  small  piece  of  wood, 
thus  acquired  the  first  idea  of  the  use  of  sudi  an 
implement  ^%  and  soon  afterwards  formed  a  metal- 
lic instrument  in  imitation  of  it  ^. 


'*  Pope'8  Homer's  lUad,  book  xxiii.  Une  973. 

i«  Diodorus  Siculus,  lib.  iv.  p.  319.  Ovid.  Meiam.  Ub.  ym. 
verae241. 

^  The  invention  of  the  potter's  wheel  is  also  attributed  to 
thifi  young  architect. 


or  EDGE  TOOLS.  477 

Of  all  the  m«tals,  tliere  is  none  wli'ich  is  so  uni- 
versally distributed  over  the  face  of  the  eartli  as 
iron;  but  the  heat  which  is  necessary  for  the  sepa- 
ration of  it  from  the  ore  is  so  intense,  that  we  can- 
not wonder  at  many  nations  remaining  long  en- 
tirely ignorant  of  its  use,  and  even  of  its  existence  ; 
or  that,  when  the  knowledge  of  making  it  was  lost 
at  the  Flood,  a  long  period  should  elapse  before  this 
curious  art  was  entirely  recovered. 

Accordingly,  we  find  that  spears  and  other  in- 
struments for  exterminating  wild  beasts,  and  even 
implements  of  agriculture  ",  were  formerly  made 
with  gold  and  silver  ;  and  in  confirmation  of  this, 
Diodorus  Siculus  says  that  tlie  Arabians,  "because  ■ 
they  have  abundance  of  gold,  and  contrarily  are  in 
want  of  brass  and  iron,  exchange  the  one  for  the 
other  with  merchants  "."  Jonston  says,  that  "  at 
the  island  of  Zabur,  fourteen  pounds  of  iron  were 
bartered  for  250  pounds  of  gold  *'." 

As  the  wants  of  mankind,  however,  increased, 
many  of  the  purposes  to  which  these  precious  me- 
tals were  applied  were  accomplished  by  means  of 
copper,  this  being  a  metal  more  easy  to  be  procured 
than  malleable  iron.  Thus  we  find  that  the  do- 
mestic implements  and  most  of  the  instruments  of 
war  of  antiquity,  which  in  our  times  are  occa^on- 


•'  DiodoTUs  SiculuH,  lib.  i.  p.  19.  Gopiet's  Origin  of  t^ws, 
&c.  vol.  i.  p.  153  8ic. 

^  Ci^n'it  rrofutdfim,  folio,  London,  16.'>3,pHgr  141. 

"  Jonston'n  History  of  tbt  IVondtrful  Thiti«t  of  Nature, 
folio.  London  169?,  ptigc  123. 


A 


478  ON  TKK  Ai AN  UFACTU  RE 

ally  found  in  every  quarter  of  the  globe^  at?  all 
either  of  copper  or  brass.  UaUl  very  btely,  indeed^ 
all  the  edge  tools  that  were  in  use  in-,  the  ialaad  nf 
Japan  were  of  copper,  or  made  with  some  aUojrcf 
that  metal  ^. 

It  is  related  among  some  of  the  earliest  bistori*> 
cal  facts  now  on  record,  that  l^meon  land  Iievi^  two 
of  the  sons  of  Jacob,  entered  Sechem  ^word  io 
hand,  to  slaughter  the  inhabitants  of  that  city  ^;  bot 
it  is  very  probable,  as  the  President  Gk)gu^  bw 
shown,  that  these  swords  were  not  of  steel  Imt  d 
copper :  therefore,  if  the  Hebrews  had  the  meaM  of 
hardening  and  tempering  copper,  as  it  has  been.M? 
serted,  very  powerful  weapons  may  have  been  tomH 
with  it,  especially  if  they  alloyed  it  with  some;oth<r 
metal  or  metals,  as  was  the  practice  Math  tbcmt 
cient  inhabitants  of  Peru,  when  they  employed  it 
in  the  fabrication  of  edge  tools  ^^.  » 

The  abundance  of  celts  and  other  instruments  of 
antiquity,  found  in  every  country  of  Europe,  as  well 
as  in  a  variety  of  places  in  other  quarters  of  the; 
globe,  shows  that  copper  and  brass  were  formerly 
in  very  general  use.  Macrobius,  who  wrote  in  the 
fourth  century,  tells  us,  that  when  the  ancnent 
Etruscans  intended  building  a  new  city,  they  markr 
ed  out  its  limits  with  a  coulter  of  brass ;  and  that 
the  priests  of  the  Sabines  were  in  the  habit  of  cut- 

^  See  Goguet*8  Origin  of  Laws,  vol.  i.  page  158. 

**  Genesis  xxxiY,  25. 

•'  Goguel,  vol.  i.  page  159. 


OF  EDGE  TOOUt  479 

ting  their  hair  with  a  knife  of  ^he  same  metal  '\ 
In  the  sacred  books  we  read  of  fetters  of  brass.  See 
Judges  xvi.  2L 

There  is  one  circumstance,  however,  which  shows 
that  instruments  of  steel  were  known  to  the  ancient 
Egyptians,  and,  after  them,  to  the  Greeks  and  Ro- 
mans. What  I  refer  to  is  the  existence  of  obelisks, 
statues  and  urns  of  porphyry ^  which,  though  of 
undoubted  antiquity,  are  curiously  carved  and  eix- 
graved,  in  a  way  which  could  not  have  been  eflfect- 
ed  with  tools  of  a  common  temper.  It.  has  been 
generally  understood  that  nothing  but  emery  or 
diamond  powder  would  touch  porphyry,  and  I  be- 
Ueve  we  have  no  tools  at  the  present  day  that  are 
capable  of  engraving  it.  The  porphyry  obelisks  at 
Rome  are  however  not  only  very  curiously  carved* 
but  graven  also  with  hieroglyphics;  and  though 
these  are  distinctly  cut,  the  obelisks  themselves 
have  not  suffered  in  the  least  by  their  exposure  to 
the  weather  through  so  long  a  series  of  ages.  This 
shows  their  extreme  hardness,  and  how  highly  the 
tools  must  have  been  tempered  by  which  they  were 
sculptured  and  engraved.  Among  other  notices  in 
the  8th  volume  of  the  Philosophical  Transactions, 
at  page  6014,  *Uo  retrieve  the  art  of  hardening 
and  tempering  of  steel  for  cutting  of  porphyry,'*  is 
mentioned  as  an  important  desideratum.  See  more 
on  this  subject  in  the  Appendix. 

In  the  time  of  the  Grecian  historian  Agathar- 

•^  Macrobim,  Saturnalia,  lib.  v.  cap.  19.  page  512. 


480  ON  THB  MANUFACTURE 

cides,  who  lived  nearly  two  handred  yean  beioie 
Christ,  chisels  and  hammers  of  copper  were  ntj 
commonly  found  among  the  rubbish  of  old  nuniei : 
and  since  that  period  hatchets  of  copper  have  been 
discovered  in  the  tombs  of  the  ancient  Peruvians  **• 
AH  these  may  probably  hax-e  been  very  useful  uten- 
sils, especially  if  the  fttbricators  of  them  were  ae- 
quainted  with  any  method  of  giving  bardneas  to  that 
metal.  ' 

It  may  here  be  remarked,  however,  that  became 
no  iron  instruments  of  considerable  antiquity  are 
now  found,  we  are  not  to  conclude  that  the  andenti 
never  employed  iron  for  such  purposes ;  for  it  k 
easy  to  imagine  that  tools  of  iron  or  steel  may  iMwe 
existed,  and  been  destroyed  by  the  hand  of  ttma. 
Iron  is  so  necessary  for  the  support  of  animal  aodl 
vegetable  life,  that  nature  has  endowed  it  widi  an 
affinity  for  oxygen,  carbon  and  sulphur,  mudi 
greater  than  that  of  most  other  metals,  in  order  that 
it  might  be  universally  distributed.  It  is  thereficMre 
difficult  to  conceive  how  an  implement  of  iron  could 
lie  in  the  ground  for  a  thousand  years  without  be- 
ing destroyed. 

But  to  return  to  our  subject.  The  President 
Goguet,  a  writer  of  great  credit,  and  whom  I  hav$ 
often  quoted  in  this  Essay,  has  asserted  that  the 
Count  de  Caylus,  who  died  nearly  sixty  years  ago^ 
had  discovered  the  art  of  tempering  copper,  *'  so 


^  Many  authorities  for  these  fiicts  may  be  seen  in  Graguet*K 
Origin  of  Laws,  vol.  i.  page  158. 


OF    EDGE   TUOL'J.  481 

as  to  bear  the  griiidBtoiie,  and  be  possessed  of  all 
the  properties  of  iron"  for  tlie  purpose  of  manufac- 
turing edge  tools  ''.  I  am,  iiowever,  constrained 
to  say  that  I  very  much  doubt  tlie  accuracy  of  this 
account,  though,  if  it  were  so,  it  is  much  to  be  la- 
mented thnt  he  did  not  impart  the  secret  for  the 
purpose  of  its  being  made  public.  Sage,  however, 
has  announced  that  by  combining /*Ao^/ior/w  with 
copper,  he  has  made  it  resemble  steel  in  colour, 
grain,  and  hardness,  and  absolutely  fit  for  a  variety 
of  purposes  to  which  steel  has  hitherto  been  ap- 
plied "', 

If  we  inquire  respecting  the  state  of  the  metallic 
arts  among  the  ancient  Britons,  it  will  appear,  from 
the  prodigious  numbers  of  copper  instruments  of 
different  sizes  and  kinds  which  have  been  found  in 
this  country,  such  as  axes,  swords,  spear-heads,  ar- 
row-heads, &c.,  all  of  which  are  known  among  an- 
tiquaries by  llie  general  name  of  cells,  that  our  an- 
cestors were  well  acquainted  with  the  art  of  form- 
ing metallic  copper  in  any  way  which  they  thought 
proper  ". 

So  lately  as  the  year  1735,  more  than  one  hun- 
dred of  these  copper  celts  were  found  on  Easterly- 
moor,  twelve  miles  from  the  city  of  York,  together 
with  several  lumps  of  metal  intermixed  with  a  quan- 
tity of  foundry  cinders,  so  that  there  can  be  no 


*•  Goguet,  page  159. 

*  See  NidmLson'a  Jtmntol,  octavo,  vol.  ix.  page  2G8. 
"  See  Leland-«  Itinerary,  vol.  i,  page  117.    Henry's  History 
of  Great  BriUiin,  vol.  ii.  page  138, 
VOL.  n,  2  I 


482  ON  THE   VAKUFACi:UR£ 

doubt  of  there  having  foriperly  beep  a  jbrge  i|t  thai 
place  for  makipg  wch  articled  ^. 

The  war-chariots  of  the  ancient  Britons  afibrd 
abundant  pro<^  th^t  they  were  expert  ip  t)ie  work- 
ing of  metals  as  w41  as  in  the  mo^lU^g  of  wood. 
*^  The  Covinus^  says  Dr«  Henry,  "  was  ^  WAr-eha« 
riot,  and  a  very  terrible  instrument  of  destructiop* 
being  armed  with  sharp  scythes  and  hooks  for  CMt** 
ting  and  tearing  all  who  were  so  unhappy  as  to  Goiw 
within  its  reach.  It  held  few  men,  but  was  de- 
signed to  be  driven  with  great  force  and  rapidity, 
and  to  do  execution  chiefly  with  its  hooks  ap4 
scythes  "•** 

Notwithstanding  the  abundance  of  iron  ore  wfaidi 
this  country  affords,  it  appears  that  the  uae  of  iqfN 
tallic  iron  is  comparatively  but  of  late  introductioo: 
for  at  the  time  of  the  first  Roman  invasion,  thk 
metal  was  so  scarce  and  rare  a  commodity  thai  the 
Britons  fabricated  their  money  with  it,  and  even 
the  trinkets  for  adorning  their  persons  **.  But 
when  the  Romans  had  made  themselves  masters  of 
the  country  they  established  imperial  foundries  for 
making  iron,  and  built  forges  for  manufacturing 
spears,  lances,  battle-axes  and  implements  of  ewtf 
kind,  in  different  parts  of  the  kingdom  ^. 

Accordingly  we  find  that  the  oi&nsive  armour  of 


'*  Borlase's  Antiquities  of  Cornwall,  page  283. 
^^  Mela^  lib.  iii.  cap.  6.    Tacitus,  Fita  Jgricolis,  cap.  36. 
^  Cssar,  de  Bella  Gallico,  lib.  v.  cap.  12.     Henry's  History 
of  Great  Britain,  vol.  ii.  page  139. 
3*  Henry,  page  140. 


OF   SDG£   TOOLS.  483 

the  cavalry  in  the  time  of  William  the  Conqueror 
was  a.long  spear  or  laoce  pointed  with  steely  very 
sharp  and  well  tempered ;  the  long  and  broad  sword 
double-edged,  and  a  short  dirk  or  dagger  ^. 

Tlie  mention  of  these  weapons  affords  me  the  op- 
portunity of  saying,  that  in  the  Annales  de  Chimin 
there  is  an  account  of  a  considerable  treatise  by 
Vandermonde  on  the  manufacture  of  bayonets  and 
the  blades  of  sabres.  This  work,  which  was  under- 
taken  by  order  of  the  Committee  of  Public  S^ety, 
contains  a  very  minute  detiul  of  the  Various  mani« 
pulations  in  the  manufactory  at  Klingental,  in  the 
department  of  the  Lower  Rhine,  accompanied  mtb 
nine  copper-plate  engravings ;  and  the  treatise  is 
spoken  of  by  the  editors  of  the  French  Journal  in 
terms  of  the  highest  approbation  ^. 

The  art  of  working  in  iron  and  steel  had  arisen  to 
such  a  state  of  improvement  in  the  10th  century, 
that  even  the  horses  of  some  of  the  chief  knights 
and  barons  were  covered  with  steel  and  iron  ar- 
mour. Artificers  who  wrought  in  iron  were  so 
highly  regarded  in  those  warlike  times,  that  every 
military  officer  had  his  smith,  who  constantly  at- 
tended his  person,  to  keep  his  arms  and  armour  in 
order.  The  chief  smith  was  an  officer  of  consider* 
able  dignity  in  the  courts  of  the  Anglo-Saxons,  and 
Welsh  kings,  where  he  enjoyed  many  privileges, 
and  his  weregeld  was  much  higher  than  that  of  any 


'•  Hoveden's  Annals,  page  350,  col.  1. 
'^  Annates  de  CInmie,  tome  xix.  page  47. 

2  I  2 


484  ON  THE  MANUFACTURE 

Other  artificer.  In  the  Welsh  court  the  kiog^s 
smith  sat  next  to  the  dofneatie  chaplain,  and  was 
entitled  to  a  draught  of  every  kind  of  liquor  that 
was  brought  into  the  hall  *. 

The  skill  which  our  ancestors  acquired  under  the 
instruction  of  the  Romans,  seems  never  to  have 
been  lost ;  for  at  the  battle  of  Hamildon  in  the  jear 
140*2,  the  repulse  of  the  Scots  appeare  to  have  been 
entirely  owing  to  the  goodness  and  excellent  teoi* 
per  of  the  arrows  which  were  employed  by  the  Eng- 
lish army.  Even  the  armour  of  the  Eiarl  of  I>o«g^ 
which  had  been  three  years  in  making,  was  perf> 
rated  by  them ;  for,  as  the  account  states,  ^  thqr 
were  so  sharp  and  strong  that  no  armour  could 
pel  them  »." 

Dr.  Martin  Lister  was  of  opinion  that  the 
cients  made  their  instruments  hardf  and  comerled 
them  into  ^eel^  by  one  and  the  same  operation ; 
that  they  first  fashioned  them  out  of  good  soft 
wrought-iron,  and  then  boiled  them,  as  he.  cat- 
presses  it,  in  fluid  cast-iron.  I  have  no  doubt  bat 
that  good  steel  might  be  made  by  this  process  ^. 

We  read  but  little  of  swards  in  the  beginning  of 
the  15th  century,  though  no  doubt  they  were  then 
in  use,  since  there  is  the  evidence  of  Geofirey  Chan- 
cer, who  died  only  two  years  before  the  memorable 


'•  Henry's  History  of  Great  BrUain,  octavo^  toI.  iy.  p.  127. 

^  Walsingham's  Historia  Brevis,  page  366.     Heniy,  toI.  x. 
page  193. 

*^  See  Philosophical  Transactions,  rot.  xvii.  page  665. 


'         l...tt1. 


OF    EDGE   TOOLS. 


battle  of  Hamildon  was  fuught,  that  Sheffield  was, 
even  then,  famous  for  its  cutlery : 

"  A  dagger  hanging  at  his  belt  he  hod, 

Made  o(  an  ancient  sword's  well  tempered  blade  ; 

He  wore  a  Sheffield  whittle  in  his  hose*'." 

Table-knives,  which  probably  were  not  in  use 
in  the  time  of  Chaucer,  were  first  made  io  London 
in  the  year  1563,  by  one  Thomas  Matthews  of 
Fleet-bridge  ".  I  have  not  been  able  to  ascertain 
the  date  of  the  introduction  of  other  kinds  of  cut- 
ting instruments  ;  but  when  the  utility  and  conve- 
nience of  these  domestic  implements  were  once  ex- 
perienced, there  can  be  no  doubt  that  the  practice 
of  using  them  quickly  became  very  general,  and 
that  manufactories  of  knives  and  other  edge  tools 
were  consequently  soon  established  in  various  parts 
of  the  kingdom.  But  in  whatsoever  manner  this 
may  have  been,  what  has  been  offered  will  suffice 
to  give  the  reader  some  idea  of  the  progress  of  the 
art  of  cutlery,  and  of  its  gradual  introduction  into 
this  country. 

It  is  time  now,  however,  to  say  a  word  or  two  re- 
specting the  design  of  this  Essay,  which  is  princi- 
pally intended  to  explain  some  of  the  most  impor- 
tant of  the  modern  processes  in  tempering  edge 
tools,  and  to  point  out  such  improvements  as  have 
occurred  to  me  while  examining  some  of  the  ma- 

"  Chaucer's  Canterbary  Talei. 

"  See  Tht  praent  State  of  Great  Britain,  London  1683, 
page  77. 


486  ON   TBI  MANVfACTURE 

nipuliitions  of  the  virioas  artists  who  are  now  em- 
ployed in  the  diflferent  branches  of  cutlery,  and  in 
the  manufacture  of  steel  ^^  both  in  its  cementation 
and  the  operation  called  tilting. 

Good  edge  tools  cannot  be  made  without  steel, 
which,  according  to  the  analysis  of  Vauquefin,  is 
generally  nothing  more  than  soft:  iron  combined 
with  a  small  portion  of  carbon,  silica  and  phospho- 
rus, and  Sometimes  a  minute  quantity  of  manga- 
nese ^.  Steel  acquires  the  magnetic  property  bet- 
ter than  iron.  Hence  good  mariners*  compaMS 
cannot  be  made  without  needles  of  steel.  The  dif- 
ferent kinds  of  steel  may  in  some  measure  be  known 
by  their  specific  gravities^.  The  smell  ofpirtrid 
garlic,  which  is  emitted  by  steel  when  dissolving  in 
diluted  sulphuric  acid,  is  probably  owing  to  the 
small  portion  of  phosphorus  contained  in  this  com- 
pound metal. 

Our  makers  of  steel  always  use  Swedish  iron  for 
this  purpose.  That  which  comes  from  Roslagen,  a 
district  in  the  neighbourhood  of  Upsal,  is  the  best 
The  steel  which  is  produced  from  it  is,  in  its  first 


^^  For  an  account  of  the  methods  of  making  steel  coosuk 
Cramer^s  Elements  of  the  Art  of  Assaying  Metals,  octavo, 
London,  1741,  page  344 — 350 ;  the  article  Stiiei«  in'  Mbc- 
quer's  Chemical  Dictionary,  vol.  iii.5.  or  Chi^tal*s  Ckemkiry 
applied  to  the  Arts,  vol.  ii.  page  197. 

**  Vauquelin,  from  the  Journal  des  Mines,  in  Nicholson's 
Quarto  Journal,  vol.  i.  page  210. 

**  See  Dr.  George  Pearson  *ft  Memoir,  in  the  PkiloMphical 
Transactions  for  1795,  page  324. 


OF   £DGE  TOOLS.  487 

state,  denominated  blistered  steel.  A  very  particu-* 
lar  account  of  the  method  of  making  steel  at  Da- 
lecarlia  in  Sweden,  will  be  found  under  the  article 
Sieel  in  Keir^s  Translation  of  Macquer*s  Chemical 
Dictionary.  The  various  sorts  of  steel  are  made 
by  very  different  managements,  and  are  thus  ren- 
dered suitable  for  as  many  diflferent  purposes. 

It  may,  however,  be  noticed  that  the  largest 
English  steel-works  are  at  Newcastle-upon-Tyne, 
at  Masbro  near  Sheffield,  at  Stourbridge,  at  Bir- 
mitigham,  and  at  the  Brades.  At  Newcastle  be- 
tween twenty-five  and  thirty  thousand  weight  of 
ftlKel  is  cemented  at  a  single  operation,  in  two  cases 
contained  in  one  furnace.  The  operation  lasts  five 
days  and  five  nights. 

There  are  five  kinds  of  steel  generally  employed 
in  this  country ;  viz.  blistered^  shear,  spur,  star, 
and  cast  steel.  The  cheapest  sort  of  edge  tools, 
and  all  articles  of  minor  importance,  are  usually 
madie  with  the  first-mentioned  kind,  united  to  a 
large  proportion  of  bar-iron.  Clothiers'  shears, 
firmer  chisels,  plane-irons,  coopers'  adzes,  scythes, 
reaping-hooks  and  large  knives,  are  commonly  made 
with  what  is  called  shear  steel.  The  spttr  and  the 
star  steel  are  used  only  for  particular  purposes,  and 
these  according  to  the  fancy  of  the  master  cutler  **. 
Besides  these,  there  is  also  a  Gennan  steel  which 
is  made  immediately  from  the  iron  ore,  by  simple 


<«  Memoire  sur  VAcier,  Sec.     By  J.  J.  Perry,  Correspondent 
of  the  Hoyul  Acjideiny  of  Beziers,  &c.  8vo.  Parif*,  1779. 


488  ON   THK   MANUFACTURE 

fusion.  Vandermonde  and  his  associates  have  pub- 
lished an  account  of  the  mode  of  producing  it  ^V 

Shear  steel  is  prepared  by  a  peculiar  process. 
Several  bars  of  common  steel  are  laid  together  and 
regularly  heated  in  an  appropriate  furnace,  until 
they  acquire  the  welding  temperature,  when  tb^ 
are  beaten  together  by  a  massy  forge-hanmier,  and 
then  drawn  out  again  into  bars  for  sale.  By  diis 
second  operation  the  blisters  are  removed,  and  the 
texture  of  the  metal  is  much  improved. 

Mr.  Joseph  G>llier  to  his  observations  on  Iron 
and  Steel  in  the  Manchester  Memoirs  has  annexed 
a  drawing  of  a  furnace  for  converting  bar  iron  into 
steel,  with  a  full  description  thereof,  which  is  wortfi 
the  attention  of  persons  interested  in  this  subject  **. 
An  abstract  from  this  paper,  together  with  the 
plate,  may  b^  seen  in  Nicholson's  Journal  **. 

The  different  kinds  of  iron  and  steel  vary  veiy 
much  in  price.  The  following  were  the  prices  of 
most  of  the  sorts  in  the  London  market,  when  the 
first  edition  of  this  work  went  to  press.  If  I  can 
obtain  an  accurate  account  of  the  present  prices^  I 
will  give  it  in  the  Appendix  to  this  volume. 

Common  bar  iron,  1 5^.  and  1 6^.  per  cwt. 

Best  Swedish  iron,  22^.  and  24^.  per  cwt. 

Common  steel,  usually  called  blistered  steel,  60^. 
to  66^.  per  cwt. 


'*''  See  Nicholson's  Quarto  Journal,  vol.  ii.  page  64. 

*^  Manchester  Memoirs,  vol.  v.  page  109. 

*^  Nicholson's  Quarto  Journal,  vol.  iii.  page  88, 


OF    EDGE   TOOLS. 


Shear  steel, 
Star  steel. 


i    1 

J.84.¥.  to  I 


I  100a-,  per  cwt. 

Spur  steel, 

Cast  steel  rolled  into  sheets,  \0d.  to  I'ld.  per  lb. 

Cast  steel  drawn  into  bars,  1^-.  to  Hrf.  per  lb. 

The  high  price  of  Swedish  iron  is  owing  to  the 
great  superiority  of  its  quality  when  compared  with 
common  English  iron ;  and  this  is  attributed  to 
the  circumstance  of  its  being  manufactured  with 
wood  charcoal,  whereas  most  of  the  English  iron  is 
prepared  by  means  of  mineral  coke.  The  Swedish 
iron,  however,  differs  very  much  in  its  quality ; 
even  one  part  of  the  same  bar  will  often  be  of  much 
greater  value  than  the  other.  Formerly  the  wire- 
workers  in  Yorkshire  used  to  go  to  Shefheld  to  buy 
foreign  iron,  on  account  of  the  circumstance  above 
mentioned :  it  was  ubual  with  tliem  to  cut  the  bars 
into  two-feet  lengths,  and  then  to  select  only  sucli 
pieces  as  were  fit  for  their  purpose,  leaving  the 
other  to  be  converted  into  steel.  It  is  no  unconi- 
mon  thing  to  find  a  bar  of  foreign  iron  tough  on 
one  side  and  quite  hard  and  brittle  on  the  other. 
If  such  iron  be  exposed  to  the  weather,  this  would 
soon  become  apparent  by  one  side  rusting  and  the 
other  remaining  quite  clean,  owing  probably  to  the 
unequal  distribution  of  the  carbon  in  its  manufac- 
ture. 

I  have  also  been  informed  that  we  have  no  artist 
in  England  who  can  make  iron-wire  fit  for  musicnt 
instruments,  and  that  all  such  wire  is  imported 
from  Holland,  and  sold  at  very  extravagant  prices. 


4§0  ON   THE  MANITFACtURE 

The  larger  kind,  such  as  is  used  in  a  piado^fiorte, 
cannot  be  bought  for  less  than  8d.  or  lOd.  pti 
ounce. 

With  regard  to  dost  steel,  the  best  penknives, 
scissars,  and  razors;  fine  saws,  surgical  instruments, 
and  every  edge  tool  which  requires  a  fine  polish,  to- 
gether with  a  great  variety  of  impkments  employlDi 
in  cutting  iron,  are  now  all  made  with  cast  steel. 

There  are  several  cogent  reasons  for  the  pte^* 
ence  of  cast  steel,  for  its  nature  is  totally  dUSTerrat 
from  that  of  every  other  species.  The  pfoportiofls 
of  the  substances  which  combine  with  iron  to  Mn- 
vert  it  into  steel  are  comparatively  very  minute ;  it 
is  therefore  necessary  that  these  should  be  intimate- 
ly and  uniformly  blended  with  the  whole  mass,  txtd 
this  is  better  efiected  by  fusion  than  in  any  otber 
way.  By  the  fusion  which  this  particular  steel  un- 
dergoes, the  grain  becomes  closer,  and  the  metal 
consequently  much  harder.  These  causes  are  suf*' 
ficient  to  account  for  cast  steel  bearing  a  higher 
{)olish  than  most  other  kinds. 

Five-and-twenty  years  ago  the  French  had  no 
knowledge  of  the  process  by  which  we  prepare  cast 
steel.  The  Committee  of  Public  Safety,  however, 
were  very  desirous  of  having  the  French  cutlers  in- 
structed in  this  art,  and  they  commissioned  Van- 
dermonde,  Monge,  and  BerthoUet  to  investigate 
the  mode  of  its  preparation.  Some  time  afterwards, 
these  eminent  chemists  published  a  memoir  on  the 
subject ;  and,  in  the  true  spirit  of  republicanism, 
they  recommended  the  dilapidutlon  of  the  principal 


OF   SD6£  TOOLS.  491 

buildings  and  establishments  of  the  ancient  monar- 
chy ;  and,  considering  the  changes  which  have  since 
taken  place  in  their  government,  it  is  arousing  to 
observe  their  enthusiasm.  -  **  Fellow-citizens,**  say 
they,  *^  let  us  convey  to  our  forges  those  expensive 
balustrades  and  railings  which  have  nothing  to  de- 
fend, and  if  we  find  them  to  possess  the  qualities  of 
good  iron,  let  us  convert  them  into  steel.**  But  it 
is  probable  that  these  individuals  were  afterwards 
ashamed  of  such  barbarous  sentiments,  for  I  ob- 
served, when  the  memoir  was  republished  in  the  An- 
nales  de  Chimie,  the  passage  which  I  have  just  quo- 
ted was  omitted  *^. 

The  superior  beauty  of  those  instruments  which 
are  made  with  cast  steel  would  have  occasioned  a 
very  great  consumption  of  this  article,  had  it  not 
.been  for  the  difficulty  of  welding  or  uniting  it  pro- 
perly with  iron,  and  which,  at  first,  occasioned  it 
.to  be  employed  only  for  those  smaller  instruments, 
jB^uch  as  lancets  and  penknives,  which  are  generally 
made  entirely  of  steel. 

However,  it  is  necessary  to  be  a  littie  more  explicit 
on  this  part  of  our  subject.  Bar-iron  cannot  be 
welded  to  another  piece  of  iron  unless  both  be 
heated  to  nearly  60^  of  Wedgwood*s  pyrometer, 
which  is  equal  to  8. 877^of  Fahrenheit's  scale,  and  is 
called  the  w^idivig-heBt  ^^ ;  but  if  cast  steel  be  heated 

*>  Annates  de  Chimie,  tome  xix.  page  42. 
.    ^^  For  an  account  of  some  experiments  by  Sir  James  HaU  on 
the  temperatures  of  iron,  see  the  sixth  volume  of  the  Edinburgh 
Pkilosophical  Transactions,  page  7 1 . 


492  ON  THE  BiANUKACTURE 

to  this  point,  it  would  be  fused,  and  nin  frmn  under 
the  hammer ;  and  hence  it  was  for  a  long  'time 
deemed  impossible  to  use  it  in  conjunction  with 
iron,  in  the  same  manner  as  the  other  kinds  of  sted 
are  employed. 

Some  nicety  is  required  even  in  the  process  of 
welding  iron,  that  the  outside  of  the  metal  does  not 
oxidize  too  much  and  fly  off  in  scales,  before  tiie 
inside  is  brought  up  to  a  welding-heat  When, 
therefore,  a  skilful  workman  is  about  to  weld  two 
pieces  of  iron,  be  carefully  observes  the  progress  of 
the  heat ;  and  if  one  becomes  too  hot,  he  rolls  it  in 
sand  to  preserve  it  horn  the  action  of  the  atnio* 
sphere ;  and  when  one  piece  acquires  the  necessary 
temperature  before  the  other,  be  covers  that  wiA 
sand  while  he  brings  the  corresponding  piece  up  to 
a  sufficient  heat  for  it  to  unite  properly  with  the 
former.  Silica  when  mixed  with  the  oxide  of  iron 
forms  a  very  fusible  compound,  which  covers  the 
work  under  operation,  and  prevents  a  further  oxida* 
tion  of  the  metal. 

I  have  said  that  it  was  formerly  deemed  impossi- 
ble to  unite  cast  steel  to  iron  by  welding ;  but  about 
thirty  years  ago  it  was  discovered  by  Sir  Thomas 
Frankland^  who  made  many  experiments  on  this 
subject,  that  if  the  cast  steel  be  made  only  of  a 
tc;Ai/^*heat,  and  the  iron  of  a  welding-heat,  the 
steel  will  then  be  soft  enough  to  unite  with  the  iron, 
and  yet  the  former  will  not  become  fluid  by  Uie 
operation.     It  will,  however,  be  proper  to  give  the 


OF    EDGE   TOOLS.  493 

necessary  temperatures  to  the  two  metals  separately, 
and  then  to  unite  them  at  one  single  lieat". 

Since  this  important  discovery,  cast  steel  has 
been  brought  into  more  extensive  use,  and^the  in- 
struments which  are  thus  constructed  are  much  bet- 
ter than  those  which  are  made  entirely  of  cast  steel. 
The  circumstance  of  an  instrument  having  its  back 
made  of  iron,  renders  it  not  so  apt  to  fly  from  the 
work  to  which  the  edge  or  steel  part  is  applied,  and 
eventually  less  liable  to  break. 

Mr.  Nicholson,  in  his  annotations  on  a  Memoir 
by  Vandermonde  and  others,  informs  us,  he  is  con- 
vinced from  his  own  experience  that  cast  steel  is  pre- 
ferable not  only  for  polished  steel  goods,  but  also  for 
cold  chisels  and  all  hard  gravers  for  turners  in  metal. 

I  have  been  the  more  desirous  of  mentioning 
these  particulars,  because,  on  a  late  journey  into  the 
country,  I  have  conversed  with  several  ingenious 
cutlers,  who  had  no  idea  that  it  was  possible  to  unite 
iron  and  cast  steel  by  the  operation  of  welding. 
Many  artists,  long  after  the  invention  of  cast  steel, 
used  to  unite  it  to  the  iron  by  means  of  rivets. 
Hoes  are  still  made  by  riveting  or  screwing  the  back, 
together  with  the  eye,  upon  a  blade  made  with 
cast  steel. 

Besides  the  various  sorts  of  steel  already  enume- 
rated, there  is  a  peculiar  kind  which  is  manufactured 
at  Bombay,  called  wootz,  which  admits  of  a  higher 


'  See  the  Philatophical  Traiuact'toni  for  the  year  i  /  95,  page 


494  ON  THE   MAMUrACTURE 

temper  than  any  other  steel ".  Mr.  Stodart  of  dx 
Strand  forged  a  piece  of  wootz  for  a  penknife^  at 
the  temperature  of  ignition  in  the  dark.  '  It  Aen 
received  the  requisite  temper  at  460^,  and  the  edge 
became  as  fine,  and  cut  as  well,  as  the  best  «ateel 
instrument.  From  this  experiment,  this  ingenioos 
artist  gave  it  as  his  opinion  that  wootz  is  sapeiioi; 
for  many  purposes,  to  any  steel  used  in  this  coon* 
try.  He  thought  it  would  carry  a  finer,  a  stronger, 
and  a  more  durable  edge  and  point,  and  that  heaet 
it  might  be  particularly  valuable  for  lancets  and 
other  fine  chirurgical  instruments  ^. 

I  have  thought  it  right  to  relate  these  particnlarsj 
because  there  is  a  probability  that  the  Freneh  and 
the  Americans  will  be  competitors  mth  us  for  the 
trade  of  the  continent  ^ ;  and  I  esteem  it  of  gmat 
importance,  that  no  opportunity  should  be  n^Ieeted 
of  directing  the  attention  of  our  respective  artists  to 
every  circumstance  that  can  have  a  tendency  to  pre- 
serve the  superiorty  of  our  national  manufactures^ 

Mr.  Mushet  of  the  Clyde  Iron-works,  a  gentlemaA 
who  has  probably  paid  more  attention  than  any  other 
individual  in  Europe  to  the  properties  of  iron  and 
steel,  has  written  an  interesting  paper  on  the  pro* 
perties  of  wootz,  in  which  he  gives  an  account  of  the 

^  See  an  account  of  experiments  on  wootz^  in  the  85th  vo^ 
Itime  of  the  Philosophical  Transactions  for  the  few  1795^  psge 
322. 

^  Philosophkal  Transactions,  rol.  85,  page  326.  Mr.  Farar 
day  on  the  Analysis  of  Wootz,  in  The  Quarterly  Journal  of 
Science,  vol.  vii.  page  288. 

**  The  Americans  have  for  several  years  past  directed  their 


OF   £DG£   TOOLS.  495 

separate  analysis  of  five  cakes  of  this  foreign  pro* 
duction,  which  he  undertook  at  the  desire  of  Sir 
Joitqph  Banks  and  sent  to  the  Royal  Sodety.  The- 
memoir  is  printed  in  the  Philosophical  Transact 
tions  and  in  Nicholson's  Journal.  In  concluding 
this  important  communication,  he  makes  the  follow* 
ing  remarks  on  the  East  Indian  ore  from  which 
wootz  is  made :  **  The  possession,'*  says  he,  **  of 
this  ore  for  the  fabrication  of  steel  and  bar-iron, 
might  to  this  country  be  an  object  of  the  highest 
importance.  At  present,^  he  adds,  *'  it  is  a  subject 
of  regret,  that  such  a  source  of  wealth  cannot  be 
annexed  to  its  capital  and  talent*^.** 

The  methods  which  are  employed  in  making 
edge  tools,  are  almost  as  various  as  the  articles 
themselves.  It  cannot,  therefore,  be  expected  that 
I  should  describe  in  detail,  or  even  completely  un** 
derstand,  the  nature  of  every  process,  especially  as  I 
was  never  personally  engaged  in  any  branch  of  the 
manufacture.  The  enumerating  of  a  few  of  the 
more  important  of  the  manipulations,  on  which 
the  artists  chiefly  rely,  will,  I  trust,  be  deemed  suf- 
ficient. 

The  cooper's  adze  and  the  carpenter's  axe  are 


attention  to  the  manufacture  of  iron  and  steel.  A  valuable  me- 
moir on  this  subject,  by  Mr.  Daniel  Little^  will  be  found  in  the 
1st  volume  of  the  Memoirs  of  the  American  Societ)'  of  Arts^ 
quarto,  printed  at  Boston,  1785. 

^  Phihiophical  Transactions,  vol.  95,  for  the  year  1805,  page 
175.  Nicholson's  Journal,  vol.  xi.  pages  221  and  284. 


496  ON   THE   MANUFACTURE 

first  formed  by  the  white-smith  in  iron,  together 
with  the  eye  for  the  hdve.  This  being  finished, 
the  instrument  is  again  heated,  and  then  the  edge 
of  the  cutting  part  is  slit  down  with  a  chisel,  and 
this  slit  filled  with  a  thin  piece  of  steel,  of  a  cor- 
responding size  and  form.  The  iron  which  had 
been  slit  open  is  then  folded  down  upon  the  steel, 
and  the  whole  is  again  submitted  to  the  action  of 
the  fire  till  the  metal  acquire  a  welding-heat,  when 
the  sledge-hammer  quickly  unites  the  iron  and  the 
steel  into  one  compact  mass.  When  the  white- 
smith is  desirous  of  finishing  these  implements  in 
the  best  manner,  he  allows  them  to  be  beaten  oa 
the  anvil  more  than  is  absolutely  necessary  for  put- 
ting them  into  the  proper  form,  because  the  more 
the  metal  is  hammered  the  tougher  it  becomes; 
This  is  the  chief  reason  why  horse-nail  stubs  are 
chosen  for  making  chains  and  other  works  in  iron 
which  require  great  tenacity. 

Scythes  and  such  other  large  instruments  are 
forged  at  the  mill,  by  means  of  a  large  hammer 
moved  by  water.  The  process  is  called  skelping. 

Augers,  gouges,  large  chisels,  table-knives'*, 
razors,  and  other  instruments  of  a  similar  bulk,  are 
forged  upon  a  large  anvil  by  the  principal  workman, 
aided  by  an  assistant  called  the  striker^  who  stands 

^'^  The  method  which  is  adopted  of  converting  old  naUs  into 
bar-iron  is  curious^  and  may  be  seen  fully  described  in  Aikiii's 
Chemical  Dictionary,  vol.  i.  page  600. 

-''  A  very  particular  description  of  the  mode  of  forging  table- 
knives  and  forks  will  be  found  in  vol.  x.  of  Rees*s  Cyclopaedia, 
Sig.  4  N,  article  "  Cutlery .'* 


OF    EDGE   TOOLS.  497 

on  the  side  of  the  anvil  opposite  to  that  where  the 
chief  operator  stands,  and  puts  in  a  heavy  blow 
with  a  sledge-hainraer  occasionally,  while  the  former 
is  fashioning  the  instrument  with  a  small  hand  ham- 
mer, and  turning  it  round  on  the  anvil,  that  it  may 
receive  now  and  then  a  blow  from  the  sledge-ham- 
mer  on  those  places  where  he  perceives  that  it  is  re- 
quired. This  is  usually  done  ivith  considerable 
adroitness,  and  by  these  means  such  instruments 
are  fashioned  in  a  quarter  of  the  time  that  would  be 
necessary  for  the  purpose  if  they  were  forged  by  a 
single  workman. 

For  making  the  articles  which  are  enumerated  in 
this  list,  shear-steel  is  generally  employed,  as  it  is 
necessary  such  instruments  should  be  entirely  free 
from  flaws ;  and  this  would  not  be  the  case  were 
the  common  steel  to  be  used  for  them.  A  facility 
is  given  to  the  forging  razors  and  some  other  in- 
struments, by  the  steel  being  previously  drawn  out 
to  a  correspondent  size  at  the  tilting-forge. 

Pfenknives,  lancets,  gravers,  surgical  instruments, 
and  other  small  edge  tools,  are  generally  forged  on 
a  small  anvil  lirmly  fixed  within  a  large  one  in  order 
to  give  greater  steadiness.  These  are  usually 
fashioned  out  of  steel  only,  and  forged  by  one  work- 
man singly  and  alone.  Scissars  are  also  forged  by 
a  single  hand:  but  the  anvil  on  which  they  are 
fashioned  is  of  a  peculiar  construction,  having  bosses 
or  (lieSy  and  beak  irons  of  various  sizes  occasionally 
adapted  to  it,  so  as  to  suit  the  different  shapes  and 
VOL.    II.  2  k 


498  ON  THE  MANUFACTURE 

dimensions  of  the  separate  parts  of  these  particular 
instruments. 

The  beak-iron,  or  bickernasit  is  sometimes  calledt 
is  a  round  taper  instrument  fixed  upon  an  anvil  in 
an  horizontal  direction,  and  designed  for  fashioning 
hollow  work  upon,  which  could  not  be  beaten  upon 
the  straight  face  of  the  anvil.  Some  anvils  have 
beak-irons  adhering  to  them,  and  others  have  square 
holes  at  one  end  for  a  moveable  beak-iron  to  drop 
into. 

It  should  have  been  noticed,  that  many  other 
tools  besides  the  axe  and  the  adze  are  originaDj 
forged  out  of  a  piece  of  iron^  with  a  little  steel  wdd- 
ed  to  it  for  the  cutting  part  of  the  instrument.  I 
have  also  heard  of  one  instance  in  which  the  steel 
is  aflBxed  to  a  tool  of  cast  iron,  and  that  an  excel- 
lent instrument  is  produced  by  this  method.  Tlus 
is  in  the  manufacture  of  Bingley*s  patent  plane-ironst 
which  are  constructed  in  the  following  manner. 

It  is  well  known  that  it  is  the  circumstance  of 
drawing  down  the  ^ A^ar-steel  under  the  tilt  hammer 
that  gives  it  the  superiority  over  common  steel. 
Mr.  Bingley  therefore  thought  that,  if  he  could  roll 
out  his  steel  much  thinner  than  it  had  ever  been 
done  before,  he  should  improve  its  quality;  and 
accordingly  a  very  thin  piece  of  steel  is  let  into  the 
face  of  a  plane-iron  made  of  cast  iron ;  and»  as  the 
steel  for  this  particular  purpose  has  to  go  through  the 
rollers  several  times  to  make  it  sufficientlv  thin,  it 
becomes  of  a  peculiar  texture,  and  the  tool  made 


OF  EDGE  TOOLS.  499 

with  it  in  found  to  suit  the  joiner  iniioli  better  than 
tlie  phine- irons  lieretofore  in  use. 

In  the  manufacture  of  edge  tools,  the  process 
which  immediately  succeeds  the  forging  is  that  of 
hardening.  All  these  cutting  instruments  are  there- 
fore fashioned  when  the  metal  is  in  its  originally 
soft  state;  and  when  they  have  attained  the  intended 
forms,  they  are  heated  afresh  to  a  particular  tem- 
perature suitable  to  the  article.  When  they  have 
acquired  that  degree  of  heat,  they  are  instantly 
plunged  into  cold  water,  which  gives  them  gi'eat 
hardness,  and  renders  tliem  capable  of  cutting  soft 
iron  or  even  steel. 

Tlie  best  cutlers  have  ascertained  that  it  is  always 
desirable  not  to  give  an  instrument  a  greater  de- 
gree of  heat  by  this  operation  tlmn  is  absolutely 
necessary ;  but  this  will  be  better  understood  as  we 
proceed  in  describing  that  process". 

Nothing  augments  the  hardness  of  steel  but  in- 
creasing the  coldness  of  the  water ;  and  hence  some 
have  had  recoui'se  to  the  solution  of  salts  in  the 
water  to  be  employed  in  hardening  A  stream  of 
ranning  water  will  make  steel  harder  than  stilt 
water,  as  fresh  portions  of  the  same  fluid  are  inces^ 
santly  presented  to  the  lieated  metal.  Some  cut- 
lers have  assured  nie  that  they  can  make  the  best 
instruments  when  they  employ  urine  in  the  process 
of  hardening.     May  not  this  be  attributable  to  the 


'  Sm  Nirbolnnn's  Quarto  Journal,  vol.  W.  pa^  I2H. 

2k2 


'•< 


500  ON  THB  MANUFACTURE 

phosphoric  salts  contuned  therein,  as  it  has  been 
demonstrated  that  phosphorus  is  one  of  the  com- 
ponent parts  of  steel  ? 

It  is  now  generally  understood  that  hardening 
by  means  of  the  strong  mineral  acids  has  no  pecd- 
liar  advantage ;  but  I  find  that  Reaumur;  from  his 
own  experience,  recommends  the  use  of  diluted  ni- 
trie  acid^.  For  the  discoveries  which  this  eminent 
man  made  respecting  the  conversion  of  iron  ulto^ 
steel,  the  Duke  of  Orleans  settled  a  pension  upon 
him  of  1 2,000  livres  a  year;  and,  at  his  request,  this 
was  settled  upon  the  Academy,  to  be  applied  after 
his  death  for  defraying  the  expenses  of  future 
attempts  to  improve  the  .arts*^ 

Experience  has  proved  that  instruments  wfaidi 
are  the  hardest  acquire  the  keenest  edge  and  are 
the  most  capable  of  cutting ;  but  then  a  great  de^ 
gree  of  hardness  always  occasions  the  metal  to  be 
brittle ;  and  when  the  edge  is  very  fine,  such  instru- 
ments are  useless  for  dividing  hard  substances, 
because  the  sharp  part  is  not  tenacious  enough  to 
endure  the  operation  without  snapping  asunder.  It 
is  necessary  therefore  to  be  content  with  less  hard* 
ness  in  order  to  obtain  the  requisite  tenacity,  and 
this  is  effected  by  the  operation  called  tempering. 

Hence,  when  an  instrument  has  been  proporly 
hardened,  it  must  be  softened  again  in  some  mea- 
sure, or  to  that  degree  which  is  thought  to  be  most 


^  See  L'Art  de  convertir  U  Fer  en  jicier,  par  M.  Reaumur^ 
page  359. 
"*  Chalmers,  vol.  xxvi.  pages  93, 94. 


OF  EDGE  TOOLS, 


501 


suitable  for  that  particular  purpose  for  which  it  is 
intended.  To  effect  tills,  it  is  heated  ag^n  only 
to  a  certain  point,  which  is  usually  determined  by 
the  colour  which  the  metal  assumes,  and  then  it  is 
instantly  plunged  into  cold  water.  This  is  called 
letting  it  down  to  the  proper  temper. 

In  France  it  has  been  the  practice,  in  hardening 
small  steel  instruments,  to  cover  them  with  soft 
soap  and  then  to  roll  them  in  common  salt.  This 
treatment  prevents  the  articles  from  scaling,  and 
does  not  prevent  the  hardening.  The  salt  fluxes 
to  a  glass  which  covers  the  metal  and  protects  it 
from  OMdizement  "*■ 

Pliny  informs  us,  that  in  his  time  the  more  de- 
licate iron  instruments  were  steeped  in  oil  to  quench 
them,  leat  they  should  grow  too  hard  and  brittle 
with  water*^.  On  the  contrary,  Jonston  says  that 
"if  iron  be  plunged  in  vinegar  it  will  endure  no 
hammering,  but  will  sooner  break  than  draw "." 
The  Iiacedsemontans,  who  made  their  coins  of  iron 
rods,  were  used  to  steep  them  in  vinegar  when  red 
hot,  that,  being  thus  rendered  brittle,  they  might 
never  be  put  to  any  other  use". 


Mr.  Rhodes,  an  eminent  cutler  of  Sheffield,  has 
published  some  very  important  observations  on  the 
process  of  hardening  steel.  "Articles  manufactured 
of  steel   for  the  purposes  of  cutting,"  says  Mr. 

"  Berthoud's  Treatiie  on  Marine  Clockt.  Quarto,  Para  1 773. 
"'  Pliny,  lib.  xxxiv.  cap.  14. 

"  Jonslon*  Hiilory  of  (At  Things  of  Nalarc,  page  123. 
"'  Plutarch,  in  fila  Lyvurgi. 


502  OV  THE  MANUFACTURE 

Rhodes,  *^  are,  almost  without  an  exception,  hard- 
ened from  the  anvil ;  in  other  words,  they  are  taken 
from  the  forger  to  the  hardener  without  under- 
going any  intermediate  process ;  and  such  is  the 
accustomed  routine,  that  the  mischief  it  confeuns 
has  escaped  observation.  The  act  of  forging  pro* 
duces  a  strong  scale  or  coating,  which  is  spread 
over  the  whole  of  tlje  blade ;  and,  to  make  the  evil 
still  more  formidable,  this  scale  or  coating  ia  un- 
equal in  substance,  varying  in  proportion  to  die 
degree  of  heat  communicated  to  the  steel  in  forging; 
it  is,  partially,  almost  impenetrable  to  the  action 
of  water  when  immersed  for  the  purpose  of  hard- 
ening. Hence  it  is  that  different  degrees  of  hard- 
ness prevail  in  nearly  every  razor  manufactured: 
this  is  evidently  a  positive  defect ;  and  so  long  as 
it  continues  to  exist,  great  difference  of  temperature 
must  exist  likewise/* 

*^  Razor-blades  not  unfrequently  exhibit  the  fact 
here  stated  in  a  very  striking  manner:  what  are 
termed  clouds,  or  parts  of  unequal  polish,  derive 
their  origin  from  this  cause ;  and  clearly  and  £- 
stinctly,  or  rather  distinctly  though  not  clearly^ 
show  how  far  this  partial  coating  has  extended,  and 
where  the  action  of  the  water  has  been  yielded  to, 
and  where  resisted.  It  certainly  cannot  be  matter 
of  astonishment,  that  so  few  improvements  have 
been  made  in  the  hardening  of  steel,  when  the  evil 
here  complained  of  so  universally  obtains,  as  almost 
to  warrant  the  supposition  that  no  attempt  has 
ever  been  made  to  remove  it.     The  remedy,  how- 


OF  EDGE  TOOLS.  503 

ever,  is  easy  and  simple  in  the  extreme,  and  so 
evidently  efficient  in  its  application,  that  it  cannot 
bat  excite  surprise,  that,  in  the  present  highly  Im- 
proved state  of  our  manufactures,  such  a  commu- 
nication should  be  made  as  a  discovery  entirely  new. 

"  Instead  of  the  customary  mode  of  hardening 
the  blade  from  the  anvil,  let  it  be  passed  im- 
mediately from  the  handsof  the  forger  to  thegiinder; 
a  slight  application  of  the  stone  will  remove  tlie 
whole  of  the  scale  or  coating,  and  the  razor  will 
then  be  properly  prepared  to  undergo  the  operation 
of  hardening  with  advantage.  It  will  be  easily 
ascertained,  that  steel  in  this  state  heats  in  the  fire 
with  greater  regularity,  and  that  when  immeraedt 
the  obstacles  being  removed  to  the  immediate  ac- 
tion of  the  water  on  the  body  of  the  steel,  the  latter 
becomes  equally  bard  from  one  extremity  to  the 
other.  To  this  may  be  added,  that,  as  the  lowest 
possible  heat  at  which  steel  becomes  hard  is  indu- 
bitably the  best,  the  mode  here  recommended  will 
be  found  the  only  one  by  which  the  process  of 
hardening  can  be  effected  with  a  less  portion  of  fire 
than  is,  or  can  be,  required  in  any  other  way." — 
"  These  observations  are  decisive,  and  will,  in  all 
probability,  tend  to  establish  in  general  use  what 
cannot  but  be  regarded  as  a  very  important  improve- 
ment in  the  manufacturing  of  edged  steel  instru- 
ments^." 

It  has  always  been  difficult  to  explain  how  the 

*°  See  an  Et$ay  on  the  JUanufaclUTe  of  it  Raior,  by  E.  Rbodci, 
eullerj  Sheffield,  octuvo,  jiHgc  20. 


L 


504  ON  THE  MANUFACTURE 

water  acts  in  hardening  iron  and  steel ;  it  is  a  sub- 
ject that  has  ever  been  involved  in  obscurity,  and  I 
do  not  recollect  to  have  seen  any  plausible  conjee* 
ture  or  theoretical  view  offered  upon  it. 

It  is  well  known  that  the  hotter  any  piece  of  iron  is 
made  and  the  more  quickly  it  is  cooled,  the  harder  it 
will  become  in  its  texture.  May  this  not  be  owing 
to  the  loss  of  its  lateni  heat  ?  When  the  metal  is 
heated,  its  latent  caloric  probably  becomesy^  ca- 
loric, and,  by  being  suddenly  plunged  into  cold 
water,  it  cools  so  rapidly  that  it  has  not  time  to 
combine  with  the  matter  of  heat  so  as  to  fix  it  in 
a  latent  state.  This  seems  the  more  probably 
because  it  is  generally  allowed  that  iron  and  sted 
owe  their  malleability  to  their  latent  heat^^ 

This,  which  at  present  is  a  mere  speculation, 
may  perhaps  deserve  investigation,  and,  by  way  of 
prosecuting  the  inquiry,  I  should  propose  the  fol- 
lowing experiment.  Let  two  bars  of  iron  be  heated 
equally ;  cool  one  of  them  quickly  and  the  other 
slowly,  and  then  notice  what  difference  there  is  in 
the  time  required  to  make  each  of  them  hot  by  the 
mere  act  of  hammering  them  upon  an  anvil ;  for, 
I  presume  the  bar  which  possesses  the  most  latent 
caloric  will  the  soonest  be  heated  to  any  given  de- 
gree of  temperature  by  this  operation ;  in  which, 
however,  the  weight  of  the  hammer,  the  frequency 


^7  The  philosophical  reader  will  understand  what  is  meant  by 
the  terms  sensible  and  latent  heat.  Those  who  are  not  aware  of 
the  different  states  in  which  the  matter  of  heat  exists  in  bodies 
may  be  referred  to  Chap.  Ill.ofllic  Chemical  Catechism. 


OF  EDGE  TOOLS.  60o 

of  the  strobes  and  their  number,  with  all  other  cU- 
cuinstances,  should  be  equal,  in  order  for  the  result 
of  the  experiment  to  be  accurate. 

But,  whatever  may  be  the  fate  of  this  experiment, 
I  am  desirous,  before  we  proceed  with  the  subject, 
to  make  one  observation  on  the  property  which  iron 
possesses,  almost  exclusively,  of  acquiring  various 
degrees  of  hardness  and  of  becoming  soft  again  at 
any  time,  as  occasion  may  require. 

It  should  be  remembered,  however,  that  steel 
differs  from  iron  in  this  circumstance, — that  if  it  be 
made  red-hot  and  then  immediately  plunged  into 
cold  water,  it  becomes  much  harder  than  it  is  pos- 
sible to  make  iron  by  such  treatment.  It  may 
however  at  any  time  hereafter  be  softened  again, 
merely  by  heating  it  afresh  and  then  allowing  it  to 
cool  gradually. 

The  property  which  iron  and  platinum  possess 
of  welding  is  very  important,  as  has  before  been 
remarked ;  but  were  it  not  for  this  singular  quality 
in  iron,  of  being  hardened  and  softened  at  pleasure, 
and  which  seems  to  me  to  be  a  striking  and  pecu- 
liar adaptation  of  a  material  to  the  uses  for  which  it 
was  originally  designed,  none  of  the  arts  dependent 
Upon  the  uses  of  this  metal  could  have  been  brought 
to  the  perfection  which  they  have  now  attained ; 
and  if  it  were  possible  for  iron  and  steel  to  lose  this 
property  of  becoming  hard  and  soft,  such  arts,  how- 
ever complete  they  may  now  be,  would  be  lost 
with  it. 


506  ON   THE   MANUFACTURE 

I  recollect  having  been  very  forcibly  impressed 
with  this  idea  when  I  first  visited  a  manufisctory  of 
printers*  types  ^.  There  the  largest  steel  punches 
which  are  employed  in  maldng  the  brass  mtoabb 
for  receiving  the  type^-metal,  and  some  of  these  are 
very  heavy,  are  all  formed  by  other  punches ;  and 
the  largest  and  deepest  letters  are  cut  out  in  diis 
manner,  by  main  force.  As  these  tools  of  sted  are 
not  hardened  till  they  are  completely  formed  by 
others  that  are  already  hardened,  the  latter  cut  oat 
the  former  with  as  little  difficulty,  to  all  appear- 
ance, as  if  they  were  operating  upon  a  piece  of  tin 
or  lead ;  and  yet  these  same  articles,  which  are  cot 
with  so  much  ease,  require  only  to  be  submitted  to 
the  hardening  process,  and  then  they  will  be  as  ca» 
pable  of  operating  upon  soft  iron  or  steel,  and  of 
cutting  either  of  them  as  readily  into  any  shi^  as 
they  were  themselves  cut  when  in  their  original 
state  of  native  steel. 

Here  I  should  be  guilty  of  great  injustice  if  I 
were  to  omit  to  notice  the  improvements  in  soften- 
ing and  hardening  iron  and  steel  which  have  been 
discovered  by  Messrs.  Perkins  and  Fairman  of  Lon- 
don, and  employed  by  them  in  preparing  steel  plates 
on  which  they  engrave  bankers*  notes.  The  methods 
are  kept  secret ;  but  Mr.  Brande  has  published  a  veiy 
curious  and  interesting  account  of  what  the  inven- 

'*  A  f\ili  account  of  the  method  of  making  printers'  types 
will  be  found  in  the  fifteenth  volume  of  Rees*s  Cycloptedia,  ar- 
ticle "  Foundry." 


OF    EDGE    TOOLS. 


tore  have  been  enabled  to  do  by  these  means,  ac- 
companied by  a  most  beautiful  specimen  ™. 

In  the  manufacture  of  edge  tools  the  most  im- 
portant process,  as  was  before  mentioned,  is  that  of 
tempering.  But,  to  effect  this  in  the  best  manner 
possible,  there  must  be,  as  Mr.  Nicholson  "  has 
happily  expressed  it,  "  a  precise  mean  between  too 
"  soft  and  too  brittle,  which  will  be  best  suited  for 
*'  the  respective  purposes  to  be  accomplished.  A 
"  spring  must  be  tenacious,  and  need  not  be  very 
"  hard.  A  knife  for  cutting  leather  and  other  soft 
"  substances,  must  be  somewhat  harder  than  a 
**  spring.  Penknives  and  razors  must  be  still 
"  harder ;  and  files  and  tools  for  working  metal 
"  must  be  hardest  of  all ;  though,  even  in  these, 
"  care  must  be  taken  not  to  destroy  their  tenacity 
"  by  making  them  too  hard." 

Hence  it  will  be  apparent  that  great  nicety  must 
always  be  observed  in  the  operation  of  tempering  ; 
and  if  due  care  be  not  taken,  there  can  be  but  little 
chance  of  the  instruments  ever  fulfilling  the  respec- 
tive purposes  for  which  they  are  designed.  The 
temper  of  a  lancet  is  generally  the  highest  of  any 
polished  steel  instrument,  and  therefore  it  is  merely 
owing  to  its  being  so  very  thin  that  it  springs  a  little 
at  the  extreme  point. 

The  usual  mode  of  ascertaining  the  temperature 
to  which  any  edge  tool  has  arrived,  is  by  attending 

••  The  Quarttrly  JoUTnal  of  Science,  sol.  ix.  page  1 21. 
*•  Nicholson's  Quarto  Jimrnal,  vol.  i.  page  381. 


SOS  ON   THE   MANUFACTURE 

during  the  operation  to  the  shades  of  colaur,  which, 
as  the  metal  becomes  more  and  more  heated,  the 
bright  parts  assume  in  rotation,  and  then  w)ien  it 
has  acquired  that  particular  hue  which  may  be  de- 
sired, removing  it  firom  the  fire  into  wfiter.  But 
the  nature  of  the  operation  is  such,  that.tlus  must 
always  be  attended  with  some  uncertainty,  espe- 
cially as  Afferent  tools  require  difiereot  manage- 
ment in  the  process,  and  it  is  often  a  very  imiier- 
tdn  task  to  give  the  same  temperature  to  every  part 
of  the  same  instrument. 

«  It  was  on  account  of  these  and  some. other  diffi- 
culties which  the  makers  of  edge  tools  constantly 
labour  under,  that  I  was  induced  to  turn  my  attri- 
tion to  the  subject,  trusting  that  I  should  be  en- 
abled to  suggest  to  the  unscientific  cutler,  wmt 
improvement  in  this  most  important  tiiough  veiy 
uncertun  branch  of  the  art.  But,  in  order  that  the 
reader  may  be  better  able  to  appreciate  what  I  have 
to  propose^  I  shall  first  show  what  particular  co- 
lours are  usually  required  for  the  tempering  of  a  few 
of  the  instruments  which  are  most  in  demand,  and 
then  explain  some  of  the  methods  now  practised 
for  the  attainment  of  some  peculiar  purpose. 

This  detail  of  the  gradation  of  colours,  I  have 
copied  from  Mr.  Nicholson's  account  of  some  ex- 
periments by  Mr.  Stodart  '*,  and  from  Mr.  Aikin : 
but  the  opinions  of  scientific  men  on  the  cause  of 
these  variations  of  colour,  have  been  very  different ; 


'*  Nicholson's  Quarto  Journal^  vol.  iv.  page  129. 


OF   EDGE   TOOLS. 


509 


and  in  my  opinion  all  of  them  are  very  unsatisfac- 
tory. Sir  Isaac  Newton  supposed  that  the  size  of 
the  metallic  particles  must  have  been  altered  by  the 
action  of  the  fire.  Later  writers  have  attributed 
these  changes  to  the  different  degrees  of  oxidize- 
inent  which  the  steel  undergoes ;  and  M.  Prieur 
has  endeavoured  to  account  for  them  by  supposing 
that  they  are  occasioned  by  an  alteration  in  the  ar- 
rangement of  the  particles,  and  that  the  colours  are 
apparently  in  concentric  rings.  TTiis  he  has  en- 
deavoured to  explain  by  tlie  feathers  of  the  peacock, 
the  neck  of  the  pigeon,  the  duck's  wing,  &c.  " 


In  tempering  edge  tools  the  first  colour,  which 
appears  at  430°  of  Fahrenheit,  is  very  pale  and  only 
a  little  inclining  to  the  yellow  ;  this  is  the  tempera- 
ture at  which  lancets  are  usually  tempered. 

At  a  little  higher  temperature,  say  450°,  the  pale 
straw  colour  appears,  which  is  a  heat  suitable  for 
the  best  razors  and  most  of  the  surgical  instru- 
ments. Then  comes  ihc  full  yellow,  at  470^,  which 
is  proper  for  common  razors,  penknives,  and  some 
other  implements  of  surgery. 

By  increasing  the  temperature  to  490^  the  brotvn 
colour  will  be  produced,  which  is  generally  looked 
for  by  those  who  have  to  temper  garden-hoes  '*, 
small  shears,  and  scissars,  and  all  those  chisels  which 
are  designed  for  cutting  cold  iron.     Then  at  SIC 


"  Atmalet  de  Chimit,  tome  Ixi.  poge  154—1/9. 
"  Some  workmen  prefer  460"  or  470"  for  garden-hoes  And 
such  like  implemenU. 


510  ON  THE .  MANUFACTURE 

comes  the  brown,  dappled  with  purpU  spots,  which 
shows  the  proper  heat  for  tempering  axes,  firmer- 
chisels,  plane-irons,  and  pocket-knives.  The  next 
colour  in  succession  is  the  purple,  at  530^,  the  heat 
at  which  table-knives  and  large  shears  are  usually 
tempered.  The  next  is  the  bright  blue^  at  55(f  , 
which  will  give  a  proper  temper  to  swords,  watdi* 
springs,  springs  for  trusses,  bell-springs,  &c.  Thett 
comes  ikitJnU  blue,  at  560^  which  being  the  hi{^* 
est  spring  temper  is  usually  employed  for  small  fine 
saws,  daggers,  augers,  &c.  This  is  the  proper  heat 
also  for  tempering  most  of  those  instruments  wludi 
require  to  be  elastic.  The  last  degree  in  succes- 
sion is  the  dark  blue  approaching  to  black,  wfaidi 
shows  itself  at  600^  and  is  the  softest  of  all  the 
gradations  of  temper,  when  the  metal  becomes  suit- 
able to  few  other  instruments  than  hand  and  pit 
saws,  which  are  necessarily  made  very  soft  in  die 
first  instance,  that  the  workmen  may  be  able  to  file 
them  up  and  set  them  whenever  they  find  occasion 
for  it,  without  being  obliged  to  soften  them  eveiy 
time  that  operation  is  to  be  performed.  This  great 
heat  is  likewise  employed  in  tempering  some  par* 
ticular  kinds  of  springs. 

Some  curious  facts  respecting  the  properties  of 
blued  steel  are  related  by  Mr.  Nicholson  on  the  tes- 
timony of  Mr.  Stodart,  who  says  ^Hhat  he  has  found 
the  spring  or  elasticity  of  the  steel  to  be  greatly  im- 
paired by  taking  off  the  blue  with  sand-paper  or 
otherwise ;  and,  what  is  still  more  striking,  that  it 
may  be  restored  again  by  the  blueing  process^  with- 


OF    EDGE   TOOLS.  3|| 

out  any  previous  hardening  or  otlier  additional 
treatment "," 

Extraordinary  as  these  facts  may  appear,  they  have 
been  fully  confirmed  by  a  manufacturer  of  Sheffield, 
who  signs  T.  B.  (probably  Mr.  Boulsover)  and  who 
writes  thus : — ■"  I  took,"  says  he,  "a  steel  plate  30 
'nches  long,  1 2  broad,  and  about  ,04  thick ;  I  hard- 
ened it  in  a  composition  of  oil  and  tallow,  and  after- 
wards tempered  it  down  to  a  spring  temper  ;  it  was 
now  so  elastic  as  to  recover  its  position  after  being 
bended — by  hammering  it  to  set  it  straight,  it  lost 
a  part  of  its  elasticity ;  after  being  ground  in  the  same 
manner  as  a  saw,  the  elasticity  became  still  less, 
having  nearly  returned  to  the  same  state  as  bc:fore 
hardened  : — it  was  then  very  uniformly  heated  un- 
til it  became  blue ;  it  now  recovered  the  whole  of 
its  elasticity : — after  being  glazed  bright  upon  a 
glazier  coated  with  emery,  the  elasticity  was  found 
to  be  impaired,  but  in  a  less  degree  than  when  it 
was  ground ; — the  same  effect  was  also  produced 
by  rubbing  with  emery  or  sand-paper,  and  also  by 
burnishing ;  invariably  the  elasticity  was  recovered 
by  blueing,  and  hence  this  is  always  the  last  opera- 
tion in  the  manufacture  of  elastic  steel  plate  ^*." 

Every  maker  of  edge  tools  well  knows  that  their 
temper  is  indicated  by  the  colour  which  they  as- 
sume ;  thus  by  observing  the  progress  of  the  co- 
lours, he  is  guided  in  operating  on  the  different 


"  Nicholson's  Journal,  vol.  J 
''  Ibid.  vol.  xiv.  page  26C. 


,  page  63. 


512  ON  THE   MANUFACrtJRE 

kinds  of  instruments,  experience  alone  being  the 
rule  in  these  cases ;  but  in  order  to  obtain  the 
most  favourable  results  in  some  instances  of  nioetj, 
there  are  other  minutise  which  require  much  care 
and  observation. 

Thus,  in  tempering  penknives  and  other  took 
which  have  a  thick  back  and  a  very  Jlne  edge,  they 
are  always  laid  with  the  backs  downwards,  dther  in 
heated  sand  or  on  a  hot  iron  plate ;  otherwise  they 
would  become  too  soft  at  the  edge,  before  the  backs 
could  be  entirely  heated. 

In  hardening  knife  blades  it  is  usual  to  plunge 
them  perpendicularly  into  the  water,  to  prevent  their 
warping  by  being  cooled  with  too  great  rapidity. 
And  here  it  may  be  remarked,  that  if  steel  be  heated 
only  to  that  point  when  it  begins  to  become  red  in 
the  dark,  and  then  plunged  into  cold  water,  such 
metal  will  not  become  hard.  The  heat  for  harden- 
ing must  indeed  be  so  great,  that  in  winter  the 
workman  is  obliged  to  take  the  chill  off  the  water 
before  the  goods  are  immersed  in  it,  to  prevent 
them  from  cracking  by  the  suddenness  of  the  trans- 
ition.  Mr.  Stodart  says  that  one  of  his  workmei 
makes  up  his  charcoal  fire  with  shavings  of  /eaiktr^' 
finding  that  this  is  effectual  in  preventing  the  toob 
from  cracking  by  this  process  ^^. 

For  the  best  methods  of  preventing  the  warping 
of  steel  instruments  in  the  operation  of  hardening, 
a  paper  by  Mr.  E.  Lydiatt  may  be  consulted  with 


'^'^  Nicholson's  Quarto  Journal,  vol.  iv.  page  128. 


OF    EDGE   TOOLS.  513 

advantage  ;  there  are  few  cutlers  who  could  not  de- 
rive some  valuable  information  from  its  perusal ". 

For  hardening  very  small  instruments  various 
other  schemes  have  been  adopted.  Thus,  fine  drills 
and  sniail  gravers  are  hardened  by  heating  them 
with  a  blow-pipe  over  a  candle,  and  then  running 
them  instantly  into  the  body  of  the  same  candle. 
In  this  way  only  one  instrument  can  be  hardened 
at  a  time ;  and  as  such  minute  tools  would  be 
cooled  too  much  before  they  could  possibly  be  im- 
mersed in  water,  this  expedient  has  been  adopted, 
and  succeeds  sufficiently. 

Formerly  some  cutlers  employed  suet,  oil,  solu- 
tions of  sal-ammoniac  and  other  salts  for  immers- 
ing the  heated  goods  into  in  the  process  of  harden- 
ing ;  but  these  methods  are  now,  I  believe,  all  aban- 
doned. Mr.  Nicholson  has  staled  that  "  Mr.  Sto- 
dart  has  not  found  that  any  advantage  is  obtained 
from  the  use  of  salt  in  the  water,"  though  he  adds 
that  "questions  respecting  the  fluid  to  be  used  in 
hardening  are,  properly  speaking,  applicable  only  to 
files,  gravers,  and  such  tools  as  are  intended  to  be 
left  at  the  extreme  of  hardness^"."  It  was  found,  in- 
deed, that  oil  had  an  injurious  eflect,  and  that  such 
cutting- instruments  as  had  been  hardened  by  being 
plunged  into  cold  oil  would  never  take  a  fine  edge. 

I  know,  however,  an  artist  who  makes  a  large 
quantity  of  truss  and  other  springs,  and  who  has  very 


"  See  Nicholson's  Joumul,  vol.  xxxiv.  page  3 
"  Nicholson's  QiiRrto  Joumal.  vol.  i».  pat;*  I 
VOL,    It.  2  I. 


i 


514  ON   THE   MANUFACTURE 

ingeniously  taken  advantage  of  this  property  which 
oil  has  of  giving  steel  a  coarse  grain.  He  conceived 
that  if  the  steel  were  less  compact  than  usual,  such 
springs  would  have  greater  elasticity ;  and  this  he 
has  long  found  to  be  the  fact :  he  therefore  now 
hardens  all  his  springs  by  heating  them  till  they  ac- 
quire the  full  blue  colour,  and  then  pliihges  them 
into  a  vessel  of  cold  linseed  oil. 

Saw-makers  temper  their  goods  in  a  different  way. 
They  rub  them  over  with  suet  or  other  grease,  and 
then  heat  them  gradually  until  the  temperature  of 
each  tool  is  raised  sufficiently  to  set  fire  to  the 
grease  of  itself,  and  occasion  it  to  blaze.  By  this 
means  they  are  thought  to  acquire  a  temper  equal 
to  what  would  be  obtained  by  heating  them  in  the 
usual  way  till  they  became  of  a  deep  blue.  The 
operation  is  called  blazing.  The  great  manufactory 
of  saws  is  at  Sheffield,  and  there  this  practice  is 
observed.  It  usually  brings  the  article  to  the  tem- 
perature of  about  600^  of  Fahrenheit. 

Mr.  Hardy,  a  skilful  artist,  who  has  written  on  the 
construction  of  Time-pieces,  says  ^Uhat  the  saw- 
makers  first  harden  their  plates  in  the  usual  manner, 
in  which  state  they  are  more  or  less  contorted  or 
warped,  and  are  brittle, — ^that  they  then  blaze  them ; 
which  process  deprives  them  of  all  springiness,  so^ 
that  they  may  be  bended  and  hammered  quite  fiUit, 
which  is  a  delicate  part  of  the  art  of  saw- making ; — ^ 
and  that  they  blue  them  on  a  hot  iron,  which  ren- 
ders them  stiff  and  springy  without  altering  the 
flatness  of  their  surface.**     He  adds  that  '^  soft  un- 


OF  EDGE  TOOLS.  515 

hardened  steet  may  be  rendered  more  elastic  by 
blueing,  and  that  hard  steel  is  more  expansible  by 
heat  than  soft"." 

I  know  of  no  instruments,  however,  which  require 
so  great  nicety  in  hardening,  as  the  files  which  are 
intended  for  sharpening  carpenters'  hand-saws.  The 
saws  themselves  being  made  of  cast-steel  are  ex- 
tremely hard,  and  therefore  the  file  must  be  still 
harder  before  it  can  make  any  impression  upon  them. 
But  there  is  a  difficulty  attending  this  process, 
namely,  that  if  these  small  instruments  be  made 
any  harder  than  is  absolutely  necessary,  they  be- 
come  brittle,  and  their  teeth  will  be  liable  to  fly  at 
every  stroke.  I  mention  this,  because  1  consider 
that  a  method  of  bringing  these  small  tools  to  a 
proper  temper,  with  certainly,  is  an  object  well 
worth  the  pursuit  of  persevering  and  ingenious  men. 

In  file-making,  the  great  desideratum  is  to  unite 
tenacity  with  hardness.  If  steel  for  this  particular 
purpose  were  made  with  animal  instead  of  vegetable 
charcoal,  this  excellence  might  probably  be  attained. 

It  is  rather  a  digression  from  the  subject  of  hard- 
ening steel  instruments,  but  it  may  be  acceptable  to 
several  of  my  readers  to  mention,  that  Mr.  G.  Cum- 
berland of  Bristol  has  recommended  the  tuaking  of 
large  files  with  a  compound  of  clay  and  ground 
silica,  and,  when  they  become  sufficiently  dry,  to 
form  the  teeth  by  the  pressure  of  muslin  of  various 
degrees  of  fineness ;  after  which  they  are  to  be  burnt. 


'  Nicholwn'i  Jmimal,  vol.  xii.  page  63. 


516  ON   THB   MANUFACTURE 

to  bring  them  to  the  hardness  of  the  best  sfame* 
ware  ^.  Such  tools  might  be  made  much  cheaper 
than  the  commonest  steel  files,  and  for  many  pur* 
poses  that  might  be  mentioned  they  would  be  of 
great  utility. 

In  visiting  a  manufactory  of  files,  I  could  not 
avoid  noticing  an  expedient  which  the  workmen 
adopt  in  the  process  of  hardening  that  instramen^ 
and  which  is,  perhaps,  as  perfect  and  efficient  as 
any  they  could  have  been  directed  to  by  the  most 
correct  knowledge  of  chemical  science,  though  it 
was  doubtless  the  mere  result  of  accident  and  obr 
servation,  without  the  aid  of  any  theory  whatever., 

Some  of  the  large  files  are  very  thick,  and  require 
to  be  submitted  to  an  intense  heat  in  order  to  give 
them  the  requisite  degree  of  hardness ;  and  yet  the 
teeth  of  these  instruments  are  sometimes  so  deli- 
cate, that  the  action  of  the  fire,  aided  by  that  of  the 
atmosphere,  would,  if  they  were  unprotected,  be 
quite  sufficient  to  convert  them  at  one  heat  to  a 
crumbling  oxide,  and  of  course  to  render  the  tool 
useless.  These  manufecturers  therefore  make  a 
mixture  of  common  salt  and  powdered  bone-asl;i 
with  grounds  or  settlings  of  ale ;  and  when  these  be- 
come of  a  proper  consistence,  each  file  is  completely 
covered  with  it  before  it  is  thrust  into  the  body  of 
the  fire. 

When  first  covered  with  this  preparation,  they 
are  laid  one  by  one  at  some  distance  above  the  fire, 

^  Nicholson's  Octavo  Journal^  vol.  xxv,  page  257. 


OF    EDGE    TOOLS.  51/ 

and  across  some  slight  bars  of  iron  fixed  within  the 
brick-work  on  purpose  to  receive  them.  Here  they 
acquire  a  sufficient  degree  of  heat  just  to  bake  on 
the  mixture,  and  harden  it  so  as  to  prevent  its  re- 
moval by  the  friction  of  the  coals  as  it  is  put  into 
the  fire-place,  Wlien  this  is  properly  baked  on, 
they  are  heated  red-hot,  and  inuuediately  plunged 
into  cold  water,  or  some  other  fluid,  to  complete  the 
hardening  process.  This  is  done  rather  slowly,  and 
at  the  same  time  care  is  taken  to  introduce  them 
into  the  water  in  a  perpendicular  position,  which  is 
necessaiy  to  prevent  these  instruments  from  warping 
by  the  sudden  transition.  Diluted  sulphuric  acid  was 
formerly  employed  for  this  purpose,  it  being  ima- 
gined that  it  rendered  the  files  harder ;  but  this  has 
lately  been  given  up,  and  recourse  is  now  generally 
had  to  coldwater  only.  Reaumur  recommends  aqua- 
fortis for  this  purpose "',  as  before  mentioned ;  but  I 
apprehend  it  is  not  better  than  cold  water  alone. 

Though  the  mode  just  described  may  be  perfect, 
the  composition  of  the  article  with  which  the  files 
are  covered  may  perhaps  be  still  improved.  Thus, 
several  artists  mix  some  antma/ substance  with  the 
saline  compound,  and  this  is  likely  to  be  a  conside. 
rable  improvement.  On  the  contrary,  some  file- 
makers  use  common  flour  instead  of  bone-ash,  and 
mix  it  with  the  saturated  s61ution  of  salt  tilt  the 
whole  acquires  the  consistence  of  treacle.    There  is 


518  ON   THE   MANUFACTURE 

an  advantage  in  this  mixture,  namely,  that  a  mere, 
single  immersion  of  the  files  in  it  is  sufficient  to 
coat  them  entirely,  and  perfectly  protect  them  from 
oxidizement. 

I  had  forgotten  to  mention,  that  when  these  in- 
struments have  been  tempered  in  the  manner  al*. 
ready  described,  they  are  well  washed  in  water^  and. 
then  brushed  with  dry  coke-dust,  which  makes  them 
quite  clean,  and  gives  them  a  considerable  degree 
of  brightness. 

It  has  been  recommended  to  make  files  for  some 
particular  trades,  with  iron,  and  then  to  case-harden 
their  surfaces,  because  such  files  would  bend,  and 
hence  might  be  made  useful  for  many  purposes  to 
which  common  steel  files  cannot  well  be  applied. 
This  method  of  preserving  the  teeth  of  files  and  rasps 
while  tempering,  is  described,  under  the  idea  that 
a  general  knowledge  of  it  might  perhaps  furnish  some 
useful  hints  respecting  the  preservation  of  metals, 
especially  iron,  from  oxidizement  during  the  pro- 
gress of  this  and  other  similar  processes  in  the  arts. 

From  these  few  observations  the  reader  may  con- 
ceive, that  the  discovery  of  some  certain  and  infedr 
lible  mode  of  imparting  liny  specific  degree  of  heat  to 
iron  or  steel,  that  may  be  necessary  for  the  processes 
of  hardening  and  tempering,  must  be  an  important 
desideratum  in  the  manufactory  of  edge  tools. 

In  the  year  1 789  Mr.  David  Hartley  took  out  a 
patent  for  a  method  of  tempering  steel  by  the  aid 


OF    EDGE   TOOLS.  519 

of  a  pyrometer  or  ihennometer  applied  near  to  the 
surface  of  the  article,  and  at  the  same  time  recom- 
mended the  use  of  heated  oil,  in  which  he  says  many 
dozens  of  razors  or  other  tools  might  be  tempered 
at  once  with  the  utmost  facility,  and  the  vaiioua 
degrees  of  heat  necessary  for  the  different  purposes 
might  speedily  be  determined  by  experiment*'. 

When  I  first  saw  this  announced  in  the  public 
journals,  it  immediately  occurred  to  me  that  the 
principle  might  be  improved  upon,  and  if  a  bath  of 
oil,  or  of  some  kind  of  fusible  metal,  were  contrived 
for  the  tempering  of  every  species  of  edge  tool,  that 
a  greater  degree  of  certainty  would  be  given  to  this 
operation,  than  the  persons  who  have  generally  the 
conductofsuch  manufactories  have  ever  experienced. 

Influenced  by  these  views  of  the  subject,  I  deter- 
mined long  ago,  that  I  would  embrace  some  oppor- 
tunity of  instituting  a  series  of  experiments,  to  de- 
termine at  H  hat  degrees  of  temperature  all  the  com- 
mon kinds  of  oil  enter  into  ebullition,  and  also  the 
melting  points  of  several  metallic  compounds,  in 
order  to  be  able  to  furnish  the  practical  cutler  with 
a  few  tables,  from  whence  he  might  leacn  how  to 
construct  a  bath  in  which  he  could  at  all  times  im- 
part the  desired  temper  to  the  particular  instru- 
ments of  his  manufacture,  with  the  utmost  certainty 
and  with  unusual  dispatch.  These  experiments 
have  been  performed,  and  those  results  which  were 
deemed  most  important  will  be  given  in  a  tabular 
form  in  the  Appendix  to  this  volume. 

**  Mr,  Nicholson  htu  given  some  account  of  this  patent  in 
Ihc  first  volume  of  his  Qiurto  Journal,  page  382. 


520  ON  THE  MANUFACTURE 

In  the  application  of  this  principle  of  tempering 
edge  tools  in  a  fluid  menstruum,  whether  metallic 
or  otherwise,  it  will  be  advisable  to  have  the  bath 
which  is  to  contain  the  heated  fluid,  made  of  east- 
iron,  which  should  vary  in  form  and  size  so  as  to 
adapt  it  to  the  particular  sort  of  tools  or  iii8tni*> 
ments  which  are  to  be  tempered  within  it.  And 
where  the  business  is  considerable,  it  would  be  con- 
venient to  have  two  such  baths  fixed  in  brickwork^ 
adjoining  to  each  other  and  heated  by  the  same  fiir^ 
with  registers  to  cut  off  the  communication  of 
either  of  them  with  the  fire-place  at  pleasure,  so 
that  one  might  be  heating  while  the  workman  was 
tempering  his  goods  in  the  other. 

Many  advantages  would  result  firom  this  method 
of  tempering  edge  tools.  In  the  first  place,  there 
could  never  be  any  uncertunty  as  to  the  d^ree  of 
temper  which  the  articles  would  acquire ;  for,  when 
the  manufacturer  had  once  ascertained  whidi  of 
(he  metallic  baths  was  suitable  for  any  particular 
kind  of  edge  tool,  all  that  would  be  necessary  would 
be  to  arrange  the  goods  in  rows  upon  the  surfisce 
of  the  congealed  metal,  to  light  a  fire  underneath 
the  containing  vessel,  and  then  carefully  to  observe 
when  the  surface  of  the  fusible  metal  b^ns  to 
melt.  As  soon  as  this  takes  place,  the  edge  tools 
are  immediately  to  be  removed  and  plunged  into 
cold  water,  by  which  means  the  whole  parcel  irill 
have  acquired  exactly  the  same  temper. 

Secondly,  where  instruments  have  a  thick  back 
and  a  fine  edge,  it  is  almost  impossible  ever  to  give 
them  an  uniform  temper  by  the  old  method ;  for 


w 


OF    EDGE    TOOLS.  521 

there  will  always  be  a  danger  of  the  edge  being 
lowered  too  much  before  the  other  parts  become 
regularly  heated  throughout.  This  difficulty  occurs 
particularly  in  razors,  where  the  thickness  of  the 
back  is  always  a  formidable  obstacle  to  the  attain- 
ment of  an  uniform  regularity  of  hardness.  It  may 
however  be  determined  by  means  of  nitric  acid, 
whether  a  razor  or  other  polished  edge  tool  be  of 
an  equal  degree  of  hardness  :  for,  on  applying  this 
acid  to  bright  steel,  the  black  tinge  will  appear 
more  speedily  and  strongly  upon  the  hard  parts  than 
on  the  rest  of  the  surface".  The  inconvenience 
attendant  on  ihe  manufacture  of  this  particular 
instrument  has  been  so  great,  that  Messrs.  Rhodes 
and  Champion,  eminent  cutlers  of  Sheffield,  have 
invented  what  they  call  the  "  New  frame-bladed 
Razor,"  in  which  the  back  and  the  finger-hold  are 
made  with  an  alloy  of  copper,  not  subject  to  rust, 
and  the  blad-.;  only  is  made  with  steel.  These  blades 
being  nearly  as  thin  at  the  back  as  at  the  edge, 
they  can  be  tempered  without  incurring  the  danger 
already  mentioned ;  and  when  one  of  these  is  let 
into  the  copper  back,  it  becomes  a  complete  instru- 
ment. This  however  is  attended  with  a  consider- 
able additional  expense,  which  would  be  unneces- 
sary if  the  plan  of  the  metallic  bath  be  adopted. 

In  the  hardening  of  large  files  and  rasps,  which 
require  to  lie  a  considerable  time  in  the  fire  before 
they  become  heated  throughout,    this   expedient 


522  ON   THE  MANUFACTURE 

would  be  of  incalculable  advantage ;  indeed,  I  know 
of  no  instrument,  except  the  gcythe,  and  the  pit- 
saw,  which  might  not  be  tempered  with  more  cer- 
tainty by  means  of  a  fluid  bath  than  by  the  proeeu 
in  common  use.  And  there  is  no  reason  for  ex- 
cepting these  but  their  great  size,  which  would  ren- 
der the  tempering  of  them  in  metallic  baths  both 
troublesome  and  expensive. 

When  the  sword  was  the  chief  weapon  of  war, 
it  must,  as  Mr.  Nicholson  has  observed,  have  been 
an  object  of  great  interest  and  demand  to  give  to 
its  blade  a  durable  keen  edge,  and  a  d^ree  of  firm- 
ness or  strength,  which,  without  rendering  it  un- 
wieldy, should  ensure  the  warrior  against  exposure 
to  the  fatal  accident  of  its  breaking  in  the  act  of 
combat. 

Formerly,  no  man  in  Great  Britain  knew  how 
to  temper  a  sword  in  such  a  way  that  it  would  bend 
for  the  point  to  touch  the  heel  and  spring  back  again 
uninjured,  except  one  Andrew  Ferrara,  who  resided 
in  the  Highlands  of  Scotland.  The  demand  which 
this  man  had  for  his  swords  was  so  great  that  he 
employed  workmen  to  forge  them,  and  spent  all  hb 
own  time  in  tempering  them  ;  and  found  it  neces- 
sary, even  in  the  day-time,  to  work  in  a  dark  cellar, 
that  he  might  be  better  able  to  observe  the  progress 
of  the  heat,  and  that  the  darkness  of  his  workshop 
might  favour  him  in  the  nicety  of  the  operation. 
Had  this  ingenious  artist  thought  of  a  bath  of  oil, 
he  might  have  heated  this  by  means  of  a  furnace 
underneath  it,  and  by  the  use  of  a  thermometer,  to 


r 


OF    EDGK   TOOL!..  523 

the  exact  point  which  he  found  necessary;  though 
it  is  inconvenient  to  have  to  employ  a  thermo- 
meter for  every  distinct  operation.  Or,  if  he  had 
been  in  possession  of  a  proper  bath  of  fusible  metal, 
he  would  have  attained  the  necessary  certainty  in 
his  process,  and  need  not  have  immured  himself  in 
a  subterranean  apartment. 

The  swords  which  were  formerly  in  the  highest 
repute,  were  made  at  Damascus  in  Syria.  The  me- 
thod by  which  these  were  made,  has  long  been  lost ; 
or  perhaps  it  was  never  thoroughly  known  to  Euro- 
peans ;  but  it  is  supposed  that  they  were  formed  by 
alternate  layers  of  extremely  thin  plates  of  iron  and 
steel  bound  together  with  iron-wire,  and  then  firmly 
cemented  together  by  welding.  These  weapons 
never  broke,  even  in  the  liardetst  eontlict,  and  yet 
they  retained  so  powerful  an  edge,  that  the  armour 
made  like  net-work  with  scales  of  iron,  or  with  small 
iron  rings,  called  coats  uf  mail,  was  instantly  divi- 
ded under  their  force. 

This  manufactory  at  Damascus  had  formerly  the 
greatest  reputation  throughout  Europe  and  through 
a  great  part  of  Asia;  but  In  the  latter  end  of  the 
fourteenth,  or  at  the  beginning  of  the  fifteenth  cen- 
tury, Timour  Bee,  usually  called  Tamerlane,  on  his 
conquest  of  Syria  **,  carried  away  all  the  best  work- 
ers in  steel  from  Damascus  to  Persia ;  and  we  know 


•*  Gibbon's  Hittory  of  the  Dteline  and  Full  nf  the  Roman 
Empirf,  vol.  xii.  pag:ca  21  and  '!.>. 


5i24  ON   THE   MANUFACTURE 

SO  little  of  Persia,  that  it  may  be  difficult  now  to 
ascertidn  whether  this  peculiar  manufectory  is  s^l 
carried  on  in  that  country  or  not. 

A  writer  in  Nicholson's  Journal,  who  bad  the 
opportunity  of  examining  a  real  Damascm  bbde, 
which  had  cost  the  possessor  twelve  guineas  at  Gin- 
stantinople,  has  thus  described  it :  *'  It  had  (says 
he)  a  dull  grey  or  blueish  appearance,  was  scarody 
harder  than  common  steel  from  the  forge,  was  not 
easily  bended,  and  when  bended  bad  no  sprii^  to 
recover  its  figure.  Its  back  was  smooth,  as  were 
also  two  narrow  sloped  surfaces  which  formed  its 
edge  under  an  angle  of  about  40  d^ees ;  but  its 
flat  sides  were  every  where  covered  with  minnle 
waving  lines  in  masses  in  all  directions,  not  cross- 
ing each  other,  and,  for  the  most  part,  running^ 
the  direction  of  its  length.  The  lines  were  in  ge- 
neral as  fine  as  harpsichord  wire,  not  extremely  wdl 
defined  nor  continued ;  and  their  distinction  firom 
each  other  was  effected  by  no  perceptible  indenta- 
tion of  the  surface,  but  rather  by  the  succession  of 
parts  differing  in  the  degree  of  polish  or  brightness.* 

*'  I  was  informed,*'  says  the  writer  of  the  menunr, 
**  that  if  any  part  of  this  blade  were  made  smooth 
by  grinding  or  whetting,  the  wavy  appearance,  call- 
ed the  water,  could  be  again  produced  by  means  of 
lemon  juice ;  and  that  its  excellencies  were,  that  it 
could  be  depended  upon  not  to  break ;  and  that  it 
would  cut  deeper  into  a  soft  substance,  such  as  a 
pack  of  wool,  or  into  flesh,  than  any  other  kind  of 
sword  blade.** 


r 


OF    EDGE   TOOLli.  525 

"I  infer  therefore,"  adds  the  writer,  "that  the 
Damascus  steel  is  in  fact  a  mechanical  mixture  of 
steel  and  iron  ;  that  it  is  incapable  of  any  consider* 
able  degree  of  hardness,  and  consequently  is  in  no 
danger  of  breaking  from  its  brittleness;  that  its  te- 
nacity is  ensured  not  only  from  the  admixture  of 
iron,  but  likewise  from  the  facility  with  which  its 
soundness  may  be  ascertained  throughout,  by  the 
same  process  which  exhibits  the  water  or  fibrous 
appearance ;  and,  lastly,  that  the  edge  of  a  weapon 
formed  of  this  material  must  be  rough,  on  account 
of  the  different  resistance  which  the  two  substances 
afford  to  the  grindstone,  in  consequence  of  which  it 
will  operate  as  a  saw,  and  more  readily  cut  through 
yielding  substances  than  such  cutting  tools  as  are 
formed  of  a  more  uniform  substance  **." 

The  conjectures  of  this  writer  respecting  the  me- 
thods by  which  these  blades  were  manufactured  at 
Damascus,  and  the  account  of  the  experiments 
which  he  himself  undertook  for  the  purpose  of  en- 
abling him  to  imitate  them,  are  extremely  interest- 
ing and  instructive,  so  much  so  that  I  have  no  he- 
sitation ill  recommending  the  whole  paper  to  the 
perusal  of  all  those  who  are  curious  in  the  manu- 
facture of  edge  tools. 

The  account  of  an  experiment  by  Mr.  Stodart 
for  imitating  the  Damascus  blades  may  be  seen  in 
Nicholson's  octavo  Journal,  vol.  vii.  page  120.  A 
paper  by  Mr.  Troughton  on  the  expansion  of  steel 
will  be  found  in  the  same  work,  vol.  ix.  page  230. 


526  ON  THS  MANUFACTURE 

I  would  not  have  it  understood  that  I  wish  to  lay 
any  claim  to  the  merit  of  the  discovery  of  metallie 
baths  for  the  tempering  of  edge  tools,  because  I 
know  of  two  or  three  individuals  who,  for  sonae  {wr- 
ticular  articles,  have  for  several  years  adopted  this 
expedient ;  but  I  have  reason  to  believe  that  the  fev 
cutlers  who  have  been  in  the  habit  of  tempering  in 
a  fluid  bath,  have  always  employed  a  thermometer; 
whereas  the  object  of  my  experiments  is  to  fumisli 
a  list  of  baths,  either  of  which  may  be  used  mth  eer^ 
tainty,  without  employing  that  instrument.  More* 
over,  as  the  practice  is  very  much  confined,  and 
few  workmen,  comparatively,  have  aqy  idea  that  it 
would  be  possible  to  render  such  a  method  avttl- 
able,  I  was  desirous  of  explaining  its  prindpks, 
and  of  furnishing  a  scale  by  which  the  manufsicto- 
rer  might  acquire  the  means  of  tempering  any  in- 
strument whatever,  in  such  a  manner  as  will  render 
it  entirely  suitable  to  the  purpose  for  which  it  is  in- 
tended. 

It  has  also  occurred  to  me,  that  by  numbering 
the  different  baths  in  a  regular  gradation,  the  work- 
man will  never  have  any  thing  respecting  the  pro* 
cess  to  charge  his  memory  with,  except  the  recol- 
lection of  the  number  of  the  bath  which  he  will 
have  to  employ  for  his  own  particular  purpose.  But 
what  has  been  offered  on  this  subject  must  suffice^ 
as  I  have  some  other  observations  to  make  before 
I  conclude  this  Essay. 

"  It  is  a  generally  prevailing  opinion,"  says  Mr. 
Rhodes,  "  amongst  men  accustomed  to  the  process 
"  of  hardening  steel,  that  if  it  be  overheated  pre- 


r       «•  viou 


OF    EDGE   TOOLS.  527 

viously  to  immersion,  an  extra  portion  of  heat  is 
**  likewise  required  to  reduce  it,  or  what  is  termed 
*'  lei  it  down,  to  a  proper  degree  of  hardness  ;  and 
*'  that  without  this  a  good  cutting  edge  cannot 
"  possibly  be  produced.  This,  indeed,  to  say  the 
"  least  of  it,  is  a  miserable  and  ineffectual  attempt 
"  to  remedy  one  error  by  the  Introduction  of  an- 
"  other.  That  this  is  an  extremely  injurious  opi- 
*'  nion,  and  that  it  operates  perhaps  more  than  any 
"  other  cause  whatever,  to  produce  a  mass  of  infe- 
"  rior  cutlery,  must  he  obvious  to  every  one  who 
"  thinks  at  all  upon  the  subject. 

"  It  may  be  laid  down  as  a  position,  which  is  not 
*'  in  much  danger  of  being  controverted,  that  the 
"  lowest  possible  heat  at  which  steel  becomes  hard 
"  is  indubitably  the  best ;  and  that  to  impart  to  it 
"  any  extra  portion,  is  essentially  to  affect  its  most 
*'  valuable  properties.  If  over-heated,  the  pores  of 
"  steel  become  open  and  expanded,  the  Bneness  of 
"  its  texture  is  annihilated,  and  it  is  rendered  so 
•'  extremely  susceptible  of  injury  from  the  influ- 
"  ence  of  heat,  that  a  small  portion  acting  upon  it, 
*'  when  it  is  in  this  state,  entirely  destroys  its  ca- 
"  pability  of  sustaining  a  cutting  edge. 

'*  It  must  not  be  inferred  from  these  remarks, 
"  that  any  degree  of  temper  whatever  will  operate 
*'  to  restore  to  steel  the  pure  properties  of  which  it 
"  has  been  deprived  by  being  over-heated.  Work- 
"  men,  hoivever,  acting  under  the  influence  of  the 
"  preposterous  opinion  here  deprecated,  manifest 
"  great  carelessness  in  the  performance  of  this  very 


528  ON  THE  MANUFACTURE 

<^  critical  operation,  always  imagining  the  evil  ef- 
**  fects  of  this  carelessness  may  be  remedied  by  re- 
''  sorting  to  a  practice  most  palpaUy  erroneous  *•* 

From  the  information  which  I  have  collected  in 
various  quarters^  I  am  inclined  to  think  that  the 
bad  temper  of  many  of  our  small  edge  tods  may 
be  attributed  to  improper  management  in  tilting 
the  steel ;  I  therefore^  on  a  late  journey  to  the  north 
of  England,  embraced  that  opportunity  of  visiting 
the  public  forge  which  is  employed  by  most  of  die 
cutiers  in  the  town  of  Sheffield,  and  where  these 
manufacturers  send  their  steel  to  be  drawn  out  into 
bars  of  different  forms  and  of  different  sizes,  accord' 
ing  to  the  various  purposes  for  which  it  is  intended. 
I  observed  that  the  process  of  tilting,  or  drawingonl 
into  fine  bars,  is  conducted  in  the  following  manner. 

The  steel,  which  is  usually  in  bars  of  24.  inches 
square  and  about  24-  feet  long,  is  put,  several  ban 
together,  into  a  wind  furnace,  that  it  may  be  suffi- 
cientiy  softened  by  heat  to  render  it  quite  ductile 
under  the  forge  hammer.  This  hammer,  which  is 
very  weighty,  is  moved  by  a  water-wheel,  and  strikes 
incessantly  upon  an  anvil  fixed  immediately  beneath 
it.  By  means  of  this  appanftus  the  heated  bars  may 
be  drawn  down  to  any  size  which  the  manuCacturer 
requires ;  and  one  man  and  a  boy  are  all  the  hands 
which  are  necessary  for  performing  the  work. 


^  An  Essay  on  the  Manufacture  of  a  Razor,    By  E.  Rhodes. 

Sheffield,  octavo,  1809,  p.  18. 


OF    EDGE    TOOLS. 

To  conduct  this  operation  the  inaii  seats  himself 
in  a  hanging  wooden  seat,  very  similar  in  appear- 
ance to  one  of  the  wooden  planks  suspended  to  a 
pair  of  large  scales,  and  which  is  fixed  to  the  ceil- 
ing by  foui'  strong  iron  wires,  in  such  a  position 
as  to  swing  directly  opposite  to  the  anvil  on  which 
the  steel  is  to  be  laid  and  drawn  into  bars. 

When  the  man  has  properly  fixed  himself  in  this 
seat,  the  boy  brings  him  one  of  the  heated  bars  and 
slides  it  under  the  forge  hammer.  The  workman 
immediately  takes  charge  of  it,  and  moves  it  a  little 
either  backwards  or  forwards  according  to  his  judge- 
ment, every  time  the  hammer  rises,  so  that  every 
part  of  the  metal  in  its  turn  may  be  uniformly  sub- 
mitted to  the  action  of  the  forge  hammer.  By  this 
repeated  hammering  the  steel  is  soon  drawn  very 
fM)n»deriibly  thinner  i  and  wlien  the  workman  finds 
that  it  is  becoming  too  cold  for  the  forging  to  make 
the  proper  impression  upon  it,  it  is  once  more  or 
oftener  heated  in  the  furnace,  and  as  often  submit- 
ted to  the  action  of  the  tilting  hammer,  until  it  be 
reduced  to  the  desired  size  and  shape. 

As  only  one  extremity  of  the  bar  ia  at  first  sub- 
mitted to  the  action  of  the  hammer,  and  aa  it  is  ne- 
cessary to  slide  it  gradually  further  and  further  un- 
derneath it,  the  workman  is  under  the  necessity  of 
approaching  nearer  to  the  anvil  or  of  receding  from 
it,  every  time  the  hammer  rises  or  falls.  To  enable 
him  therefore  to  do  this  with  facility,  there  is  a 
small  well  of  about  a  foot  deep,  sunk  within  the 
floor  for  the  reception  of  his  legs,  and  directly  under. 

VOL.  u.  2  M 


L 


530  ON   THE   MANUFACTURE 

that  part  of  the  ceiling  to  which  hb  seat  is  sus- 
pended. Things  being  thus  arranged,  the  operator 
is  enabled  by  a  slight  motion  of  his  foot,  and  with- 
out any  painful  exertion,  to  move  himself  dther 
backwards  or  forwards  as  his  work  requires. 

While  I  attended  this  operation,  I  observed  that 
very  different  degrees  of  heat  were  given  to  the 
strong  bars  in  order  to  soften  them  for  the  tilt  ham- 
mer ;  and  I  can  readily  conceive  that  the  injoij 
whieh  I  have  spoken  of  as  being  done  to  bar-sled 
at  the  tilting-house,  may  be  entirely  attributed  to 
this  circumstance — the  unequal  or  superfluous  ap- 
plication of  heat. 

I  observed,  also,  that  those  bars  which  were  un- 
necessarily heated,  threw  off  a  prodigious  numbor 
of  thin  scales  at  every  blow  of  the  hammer;  and 
when  I  made  inquiry  respecting  this,  I  was  inform- 
ed that  the  manufacturers  generally  expect  that  the 
steel  which  they  send  to  this  establishment  will  lose 
five  per  cent,  in  weight  by  the  operation  of  tilUng; 
and  that  when  the  bars  are  heated  more  than  ne- 
cessary, this  loss  is  always  proportionably  greater. 
The  charge  usually  made  for  drawing  steel  into  fine 
bars,  is  from  5s.  to  6^.  6^.  per  cwt.  according  to 
the  size  required. 

After  I  had  visited  this  public  forge  and  witnessed 
the  carelessness  with  which  the  bar-steel  is  heated» 
I  felt  extremely  desirous  of  ascertaining  the  degree 
of  effect  produced  on  cast-steel  by  being  brought 
to  too  high  a  temperature,  not  doubting  that  the 
badness  of  many  of  our  edge  tools  might  be  chiefly 


OF  EDGE  TOOLS. 

ascribed  to  this  cause.  Therefore,  before  I  left 
Sheffield,  I  procured  a  small  bar  of  cast-steel,  and 
baving  borrowed  the  use  of  a  hearth,  I  made  the 
following  experiment. 

The  bar  of  steel  was  first  broken  into  three  pretty 
equal  parts  ;  I  then  heated  one  of  these  to  a  low  red 
heat,  and  immediately  cooled  it  by  sinking  it  very 
gradually  into  a  trough  of  cold  water.  The  second 
was  heated  considerably  more,  even  to  a  full  red,  and 
cooled  in  the  same  manner.  The  third  was  brought 
to  an  intense  while  heat,  and  then  instantly  quench- 
ed in  cold  water,  like  the  preceding  parts. 

Afterwards,  on  breaking  a  small  piece  from  one 
end  of  each  of  these  bars,  the  following  appearances 
presented  themselves,  which  completely  satisfied  me 
of  the  decisive  nature  of  the  experiment.  Tlie  first 
exhibited  a  very  fine,  close,  and  compact  grain ;  llie 
second  was  of  a  much  coarser  texture;  and  the 
grain  of  the  third  was  analogous  in  all  respects,  and 
quite  as  coarse  as  that  of  a  piece  of  common  cast- 
iron. 

It  is  well  known  that  cast-steel  is  brittle  and  use- 
less before  it  be  tilted,  or  drawn  out  by  the  forge- 
hammer  ;  but  if  it  be  heated  too  much  for  this  ope- 
ration, the  texture  of  the  metal  will  be  so  much  al- 
tered by  this  excess  that  it  will  be  rendered  entirely 
unfit  for  the  fabrication  of  fine  instruments.  It  may 
here  however  be  mentioned,  that  such  steel  as  will 
suit  one  implement  is  often  not  fit  for  another. 
That  which  has  the  tnoat  blisters  is  generally  the 


k 


'2  m  2 


532  ON   THE   MANUFACTURE 

hardest  and  fittest  for  files,  Sic.;  but  the  softest 
steel,  or  that  which  approfM^h^s  the  nearest  to  the 
state  of  wrought  iron,  is  most  suitable  for  many 
other  purposes. 

There  is  another  circumstanoe  which  militates 
very  much  against  the  perfection  of  the  finer  aort  of 
edge  tools,  namely,  the  velocity  that  is  given  to  the 
motion  of  the  stones  on  which  the  instnimenta  aie 
usually  ground  and  polished.  The  workmen  at 
Sheffield  are  not  paid  for  their  time,  but  by  the 
piece,  or  according  to  the  quantity  of  work  finished ; 
it  is  consequently  their  interest  to  use  the  utmost 
dispatch,  and  urge  the  grinding-stones  to  the  most 
rapid  motion,  because  the  amount  of  the  work  will, 
in  fact,  he  in  proportion  to  the  celerity  of  the  le* 
volving  stones. 

At  Sheffield  the  stones  are  usually  moved  either 
by  a  steam-engine  or  a  powerful  water-wheel ;  there- 
fore any  degree  of  velocity  may  be  given  to  them,  by 
simply  moving  the  strap  to  a  pulley  of  a  larger  or 
smaller  diameter.  This  indeed  has  sometimes  been 
pushed  to  such  an  extent,  that  the  stones,  merely  by 
the  centrifugal  force  which  they  had  thus  acquired, 
have  been  dashed  into  innumerable  pieces,  and 
have  occasioned  the  death  of  the  workmen  and  by^ 
standers. 

Those  who  have  paid  attention  to  the  process  of 
tempering  steel  will  readily  conceive  the  great  in- 
jury that  a  fine  edge  tool  is  likely  to  suffer  from  the 


OF    EDGE   TOOL".  533 

accumulnted  Iieat  occasioned  by  a  revolving  grind- 
stone, or  other  rough  mineral  substance  in  rapid 
motion.  This  is  an  evil  of  great  magnitude  ;  but 
unless  men  of  real  principle  be  found  who  would 
willingly  engage  in  this  employment,  and  be  content 
that  tiieir  own  interests  should  be  subservient  to 
that  of  their  master,  and  that  their  first  aim  be  to 
give  perfection  to  the  quality  of  the  goods  they  fa- 
bricate, I  am  afraid  that  no  effectual  remedy  can  be 
adopted. 

In  a  late  voluminous  and  very  respectable  publi- 
cation it  is  said,  that  the  ff^ickersleij  stone  is  usually 
employed  for  grinding  edge  tools,  because  this  stone 
has  the  peculiar  property  of  not  heating  to  a  great 
d^ree  any  substance  ground  upon  it.  This  appear- 
ed to  me  to  be  so  very  extraordinary  that  I  deter- 
mined to  make  an  inquiry,  on  my  next  journey  into 
Yorkshire,  respecting  this  circumstance.  I  have 
since  however  been  assured  by  some  of  the  most  ex- 
tensive cutlers  at  Sheffield,  that  the  assertion  is 
without  foundation,  and  that  there  are  other  reasons 
for  the  preference  which  is  often  given  to  this  par- 
ficular  stone. 

Wickersley  is  a  village  situated  between  Rothe- 
ram  and  Doncaster,  about  ten  miles  north-east  of 
Sheffield.  From  the  inquiries  which  I  have  made, 
I  learn  that  this  stone,  which  is  of  a  light-buff  co- 
lour, with  a  slight  shade  of  red  intermingled,  is  used 
for  grinding  all  the  fine  hard  steel  goods,  such  as 
razors,  penknives,  and  the  best  scissars  ;  and  it  is 
preferred  for  tliese,  not  because  it  produces  a  less 


I        preferr 


534  ON   THE   MANUFACTURE 

degree  of  heat  in  the  operation  ^»  but  from  the  fine* 
ness  of  its  texture,  from  the  rapidity  with  whidi  it 
cuts,  and  from  its  not  hemg  subject  to  have  hud 
or  knotty  places  interspersed  in  it»  an  imperfection 
to  which  most  other  grindstones  are  liable.  Hie 
workmen  in  general  give  the  preference  to  these 
stones  for  articles  made  with  hard  steel ;  bat  soft 
or  unhardened  goods,  such  as  fork-shanks,  for  ex«> 
ample,  are  usually  ground  with  a  stone  whidi  pot? 
sesses  a  much  greater  degree  of  hardness. 

In  the  Supplement  to  the  JEncyciopedia  Briton- 
fuca,  article  Cutlery,  mention  is  made  of  a  green 
stone  found  in  some  parts  of  the  old  pavement  of 
London^  as  the  only  known  material  capable  of 
giving  to  lancets  the  smooth  edge  which  they  re* 
quire.  This  stone,  which  is  now  extremely  rare 
and  valuable,  is  a  soft  hornstone.  Its  analysis  has 
been  published  by  Mr.  Faraday  *. 

Another  kind  of  edge  tool  remains  to  be  de- 
scribed,  which  is  made  of  cast-iron  and  afterwards 
converted  into  steel.  The  method  of  conducting 
this  process  was  discovered  by  Mr.  S.  Liucas  of 
Sheffield,  and  he  has  obtained  a  patent  for  the  in- 
vention. In  order  that  all  classes  of  readers  may 
be  able  to  appreciate  the  merits  of  this  very  inge- 

^  It  appears  from  a  memoir  by  Mr.  Nicholson,  that  hard  tal- 
low may  be  applied  to  grindstones  with  g^at  advantage,  for 
lessening  the  quantity  of  heat  usually  developed  in  the  opera- 
tion of  grinding.  He  has  explained  its  action  on  true  chemical 
principles.     See  Quarto  Journal,  vol.  i.  page  131. 

•^  $>ec  Mr.  Bninde's  Quarterly  Journal,  vol.  vii.  page  400. 


OF    EDGE   TOOLS. 


535 


nious  process,  it  will  be  necessary  to  explain  what 
constitutes  the  difference  in  the  various  sorts  of  iron, 
and  likewise  in  what  respect  this  differs  from  steel. 

Iron  is  found  in  the  state  of  an  ore  in  the  bowels 
of  the  earth,  and,  in  abstracting  from  this  an  useful 
metal,  the  first  product  is  generally  cast-iron,  which 
owes  its  fusibility  to  the  combination  of  carbon  and 
o:q'gen*.  This  varies,  however,  in  quality  accord- 
ing to  the  quantity  of  carbon  combined  with  it; 
and  consequently  such  kinds  are  selected  as  are 
thought  to  suit  the  different  purposes  to  which  they 
are  to  he  applied.  That  whicli  contains  the  most 
carbon  is  chosen  for  small  castings  and  for  the 
□eater  kinds  of  ornamental  work,  while  the  harder 
metal,  which  has  less  carbon,  is  always  preferred 
for  railways,  water-wheels,  and  all  other  large  arti- 
cles which  are  designed  to  sustain  much  wear. 

It  is  necessary  that  the  carbon  be  intimately 
united  with  the  metal  to  form  good  pig-iron.  This 
accounts  for  the  preference  which  is  always  given 
to  that  iron  which  is  made  with  wood-charcoal,  for 
this  enters  more  readily  into  combination  with  the 
iron  than  even  the  best  mineral  coke.  When  coke 
is  employed  in  the  process  of  making  pig-iron,  that 
which  is  the  softest  is  always  found  to  be  the  best, 
while  the  hard  coke  is  selected  for  heating  the  blast 
furnaces. 

Wrought  iron  is  malleable  though  very  infusible, 


"  I  duubl  Ihe  presence  of  ojtygcn  in  Lost-in 
compatible  with  cnrbon  in  a  high  tempcrntUK. 


,  it  being  in- 


k 


536  ON   THE   MANUFACTURE 

and  it  acquires  these  changes  in  its  properties  by 
continued  heat  and  repeated  hammering,  whidi 
dq>rive  the  metal  in  a  great  measure  of  the  oxygai 
and  carbon  ^  wiiich  occasioned  its  great  fosibifi^ 
when  in  the  state  of  cast  iron.  But  it  Taries  very 
much  in  its  quality,  according  to  the  mode  oi  its 
preparation,  and  the  nature  of  the  coke  or  diarcoal 
which  has  been  employed  in  its  manufacture. 

Sieel  differs  from  wrought  as  weU  as  from  cast 
iron,  in  having  resumed  a  small  portion  of  carhoBs 
and  likewise  by  containing  a  very  minute  propor- 
tion of  silica  and  phosphorus  ®^  Steel  is  a  most 
important  preparation  of  iron;  for  it  possesses  tiie 
malleability  of  wrought  iron  without  its  infusibili^, 
and  also  has  the  fusibility  of  cast-iron  without  the 
Imttleness  of  that  substance.  It  completely  onilcB 
the  malleability  of  the  one  with  the  fusibility  of  the 
other.  A  particular  account  of  the  methods  by 
which  steel  was  usually  prepared  in  the  middle  of 
the  last  century  is  given  by  Mr.  Dossie  in  his 


*  Mr.  Mushet  has  published  the  following  table  of  the  pro- 
portions of  carbon  in  the  different  kinds  of  iron  and  steel.  See 
Phil.  Mag.  vol.  xiii. 

Soft  cast  steel ^i^ 

Common  ditto ,^ 

Ditto  harder    ^ 

Ditto  too  hard  for  drawing . .  ^ 

White  cast  iron   ^ 

Mottled  ditto ,\y 

Black  ditto t^ 

''  An  account  of  the  process  of  making  native  steel  by  the 
.simple  fusion  of  an  iron  ore  found  in  Stirta^  ts  given  in  the  An- 
fifties  de  ChimiCy  tome  xix.  p.  18 — 2D. 


r 


OF    EDGE    TOOLS. 


537 

tutes  *.  Some  Recount  of  the  jfresent  modes  of 
making  both  the  bUstered  and  the  shear  steel  has 
already  been  given.  Cast-steel,  according  to  Mr. 
Aikin,  is  made  by  the  following  process: — 

"The  finest  kind  of  steel,  called  English  cast 
steel,  is  commonly  prepared,"  says  he,  *'  by  break- 
ing to  pieces  the  blistered  steel,  and  then  melting 
it  in  a  crucible  with  a  flux  composed  of  carbona- 
ceous and  vitrifiable  ingredients.  The  vitrifiable 
part  of  the  mixture  is  of  use  only  inasmuch  as  it  is 
a  fusible  body,  which  flows  over  the  surface  of  the 
metal  in  the  crucibles,  and  prevents  the  access  of 
the  oxygen  of  the  atmosphere.  Broken  glass  is 
sometimes  used  for  this  purpose. 

"  When  the  metal  is  thoroughly  fused,  it  is  cast 
into  ingots,  which  by  gentle  heating  and  careful 
hammering  are  tilted  into  bars.  By  this  proeess 
the  steel  becomes  more  highly  carbonized  in  pro- 
portion to  the  quantity  of  flux,  and  in  consequence 
is  more  brittle  and  fusible  than  before.  Hence  it 
surpasses  all  other  steel  in  uniformity  of  texture, 
hardness,  and  closeness  of  grain,  and  is  the  mate- 
rial employed  in  all  the  Bnest  articles  of  English 
cutlery  *'." 

Tiiree  or  four  years  ago,  Oostad  Muhainmed  All 
described  in  the  Laboratory  of  the  Royal  Institution 
of  Great  Britain  the  method  of  making  cast-steel 

"  Dojuie's  Inslilutet  of  Experimental  Chemiairy,  vol.  ii.  pages 
375—388. 

»>  Aikin'M  C^(Mit(i(  Dii-tioiiarg,  nrtid*:  Iron,  vol.  i.  p.  602. 


538  ON   THE   MANUFACTURE 

in  Persia.  The  iron,  he  said,  is  brought  from  the 
mountains :  a  square  place  is  built  up,  about  four 
feet  in  the  side,  and  five  or  six  feet  high,  the  waUs 
eight  or  nine  inches  tliick ;  stones  of  a  slaty  kind 
are  placed  in  the  inside  about  18  inches  from  die 
bottom,  so  as  to  form  a  grate;  below  this  is  a  cham- 
ber  for  the  reception  of  the  melted  steel,  and  above 
it  is  placed  the  iron  in  bars,  and  charcoal  intow 
mingled  together.  There  are  three  apertures  above 
the  grate  into  the  furnace,  into  which  air  is  pro- 
pelled from  bellows  worked  by  men  sitting ;  a  fire 
is  lighted,  and  the  heat  rsised ;  fresh  charcoal  is 
thrown  on  as  that  in  the  furnace  bums  away ;  and 
as  the  iron  becomes  carbonized,  it  melts  and  fidk 
through  the  grate  as  fluid  cast-steel,  into  the  cham- 
ber beneath,  from  whence  it  is  taken  and  cast  into 
ingots. 

To  prepare  the  cast-steel,  three  or  four  hundred 
weight  of  iron  is  placed  in  such  a  furnace,  and  there 
is  a  loss  of  about  one-third  firom  oxidation,  and 
adhesion  to  the  sides.  The  operation  requires  from 
two  to  three  days,  with  constant  blowing.  M.  Mu- 
hammed  described  the  charcoal  that  was  employed, 
as  being  exceedingly  hard  and  heavy,  and  very  un- 
like our  charcoal,  but  did  not  know  of  what  wood 
it  was  made  **. 

The  invention  by  Mr.  Lucas,  of  converting  edge 

^  Quarterly  Journal  of  Science,  vol.  viii.  page  160. 


OF    EDGE   TOOLS. 


5-i'J 


tools  made  of  cast-iron  into  good  steel,  nppears  to 
be  an  important  improvement.  It  consists  in  stra- 
tifying the  cast  articles,  in  cylindrical  metallic  ves- 
sels, with  native  oxide  of  iron  pulverized,  or  sand 
containing  oxide  of  Iron,  and  then  submitting  the 
whole  to  a  regular  heat  in  a  furnace  built  for  the 
purpose.  It  is  not  necessary  that  the  oxide  em- 
ployed should  be  a  nafive  oxide,  any  artificial  oxide 
being  equally  effective ;  that  kind  which  can  be  had 
cheapest  is  therefore  generally  preferred.  The  ope- 
ration may  he  thus  explained: — 

The  cast-iron,  of  which  this  cutlery  is  made,  U 
brittle  in  the  first  instance,  like  other  cast-iron,  in 
consequence  of  the  carbon  contained  in  it ;  but  the 
great  heat  which  it  undergoes,  aided  by  the  pulve- 
rized oxide,  separates  the  carbon  :  this  uniting  with 
the  oxygen  of  the  ground  oxide  of  iron,  is  dissi- 
pated in  the  state  either  of  carbonic  oxide  or  carbo- 
nic acid  gas,  and  the  goods  are  tlien  converted  into 
a  state  very  similnr  to  that  of  good  cast-steel  cutlery. 

To  prevent  misconception,  it  may  be  necessary 
to  state,  that  cast-iron  which  contains  a  large  pro- 
portion of  carbon  is  less  brittle  than  that  which  is 
combined  with  a  smaller  quantity.  It  can  also  be 
tiled  and  cut  with  a  cold  chisel,  while  the  latter,  al- 
though it  may  be  more  readily  broken,  effectually 
resists  the  action  both  of  the  chisel  and  the  61e.  In 
conformity  with  these  facts,  small  machinery  made 
of  common  cast-iron  may  be  softened  merely  by  ce- 
mentation with  a  larbonaceous  substance,  thereby 


540  ON   THB   MANUFACTURE 

Augmenting  its  dose  of  earbon,  and  rendering  it  ca- 
pable of  being  smoothed  by  the  file. 

I  understand  that  the  best  pig-iron  is  alvrays 
dhosen  for  making  the  various  articles  of  cutlery, 
while  the  poorest  iron  ore,  if  free  from  sulphur, 
Aiay  be  pulverized  and  stratified  with  them  to  aflbrd 
oxygen. 

After  several  years  experience,  Mr.Thomas  Lucas 
has  been  enabled  to  bring  this  process  to  such  a  state 
of  perfection,  that  his  cast  cutlery  will  bear  a  polish** 
equally  brilliant  mth  the  best  cast-steel  goods,  as  I 
can  testify  from  my  own  observation ;  and  will  also 
take  as  fine  an  edge,  so  that  some  of  the  best  judges 
of  cutlery  cannot  distinguish  the  difierence.  When, 
however,  the  cast  cutlery  wares  which  have  been  thus 
annealed,  are  submitted  to  the  usual  processes  of 
hardening  and  tempering,  they  are  apt  to  be  more 
brittle  than  those  edge  tools  which  are  made  in  the 
usual  way  with  the  best  steel. 

It  has  also  been  found  that  by  varying  the  pro- 
cess small  pig-iron  castings  can  be  converted  into 
good  malleable  iron:  in  consequence  of  this  the 
Patentee  now  makes  a  great  variety  of  small  iron 
utensils  by  castings  which  were  formerly  made  only 

^  Directions  by  Messrs.  Stodart  and  Hume  for  presenriii^ 
polished  steel  instruments  from  rust  by  means  of  an  ethereal  so- 
lution of  gold^  are  given  in  Nicholson's  Journal,  vol.  xi.  p.  215. 
A  paper  by  Mr.  Stodart  on  covering  steel  with  platinmn  ii 
printed  in  the  same  volume^  page  262.  See  also  a  paper  on 
the  same  subject  by  Guyton  Niorveau  in  the  Annates  de  Chimie, 
tome  77,  page  297. 


OF   EDGE   TOOLS.  541 

on  the  anvil  of  the  blacksmitli ;  and  when  he  has 
converted  the  metal  to  the  quality  of  soft  malleable 
iron,  these  articles  are  found  to  be  equally  fit  for  a 
great  variety  of  purposes,  and  can  be  afforded  at  a 
much  lower  rate  than  similar  goods  which  have  been 
modelled  by  hand,  as  heretofore.  He  has  become 
80  complete  a  master  of  this  business,  that  he  can 
convert  cast-iron  goods  either  into  the  state  of 
wrought  iron  or  steel  at  pleasure. 

Mr.  Lucas  has  shown  me  articles  made  with  pig- 
iron  which  appeared  perfectly  malleable.  I  have  seen 
cast  nails  which  would  bend  like  common  wTOught 
iron  nails,  and  small  articles  that  would  bear  even  to 
be  welded  together  by  the  usual  process. 

In  conducting  these  operations,  he  has  sometimes 
observed  that  when  dark  or  highly  carburetted  cast- 
iron  is  fused  in  small  quantities,  plumbago  is  sepa- 
rated, and  the  metal,  by  thus  losing  a  part  of  its 
carbon,  becomes  white.  Here  a  question  occurs ; 
— Why  did  not  the  plumbago  separate  on  the  first 
cooling  ?  Is  it  not  probable  that  crude  iron  com- 
bined with  a  certain  portion  of  carbon,  is  thereby 
rendered  capable  of  dissolving  and  retaining  in  com- 
bination a  quantity  of  plumbago,  in  the  same  man- 
ner ns  water  saturated  with  carbonic  acid,  will  dis- 
solve un  extra  portion  of  carbonate  of  linte  ? 

I  have  also  to  observe,  that  the  steel  which  the 
Patentee  makes  by  the  process  of  cementation,  pos- 
SMses,  in  common  with  that  manufactured  in  the 
usual  way,  the  susceptibility  of  being  powerfully 


542  ON  THE   MANUFACTURE 

magnetized,  and  appears  to  retain  the  magnetic 
property  as  well  as  other  steel.  He  has  indeed  in 
his  possession  a  small  instrument  in  the  form  of  a 
horse-shoe  magnet,  made  with  cast-iron  and  after- 
wards converted  by  his  peculiar  process  to  steel, 
which  he  has  had  magnetized,  and  it  is  now  capa- 
ble of  sustaining,  by  its  magnetic  power,  a  wdgfat 
nearly  equal  to  three  pounds. 

I  have  only  to  add  that  Mr.  Lucas  has  very  obli* 
gingly  furnished  me  with  a  drawing  of  the  furmioe 
which  he  employs  in  these  processes,  and,  with  fais 
permission,  I  have  thought  it  worth  while  to  have 
a  copper-plate  engra^ng  of  it  made  to  accompany 
this  Essay. 

Since  the  publication  of  the  former  edition  of 
these  Essajrs^  Messrs.  Stodart  and  Faraday  have  uik 
dertaken  a  series  of  very  important  experiments  on 
the  alloys  of  iron  and  steel,  with  various  other  me- 
tals; the  object  of  which  was,  first  to  ascertain 
whether  any  alloy  could  be  artificially  formed,  bet- 
ter for  the  purpose  of  making  cutting  instruments 
than  steel  in  its  purest  state ;  and,  secondly,  whe- 
ther any  such  alloys  would,  under  similar  circum- 
stances, prove  less  susceptible  of  oxidation.  An 
account  of  these  experiments  having  been  given  in 
considerable  detail,  both  in  the  Philosophical  Trans- 
actions, and  in  the  Quarterly  Journal  of  Science, 
I  trust  that  a  careful  abridgement  of  all  the  papers 
on  this  subject,  or  at  least  a  transcript  of  the  most 


OF  EDGE  TOOLS.  543 

important  results  of  the  several  experiments,  will 
be  useful  and  highly  acceptable  to  the  public. 

These  Experimentalists  found  that  by  combining 
a  very  small  portion  of  alumina  with  good  steel,  an 
artificial  wooiz  was  produced,  which,  when  the  sur- 
face was  polished,  gave,  on  the  application  of  dilute 
sulphuric  acid,  the  beautiful  damask  appearance 
which  has  hitherto  peculiarly  belonged  to  the  Asi- 
atic steel.  It  is  remarkable  that  the  wootz,  although 
repeatedly  fused,  retains  the  peculiar  property  of 
presenting  a  damasked  surface,  when  forged,  polish- 
ed,  and  acted  upon  by  dilute  acid**. 

"Platinum,  rhodium,  gold,  silver,  nickel,  copper 
and  tin  were  alloyed  with  both  English  and  Indian 
steel,  and  in  various  proportions.  All  these  metals 
have  an  affinity  for  steel  sufficiently  strong  to  make 
them  combine ;  and  this  is  so  remarkable  with 
platinum,  that  it  will  fuse  when  in  contact  with 
steel,  at  a  heat  at  which  the  steel  it&elf  is  not  af- 
fected". 

"  When  one  part  of  silver  to  500  parts  of  steel 
were  properly  fused,  a  very  perfect  button  was  pro- 
duced. The  specimen  forged  remarkably  well,  al- 
though very  hard.  By  a  delicate  test  every  part  of 
the  bar  gave  silver.  This  alloy,  they  say,  is  deci- 
dedly superior  to  the  very  best  steel,  and  this  ex- 
cellence is  unquestionably  owing  to  combination 
witli  a  minute  portion  of  silver.  It  has  been  repeat- 
edly made,  and  always  with  equal  succeatt.    Various 

•°  The  Quarterly  Journal  of  Sritnce,  vol.  ix,  page  320. 
"  ;f<u/.  page  325. 


544  ON  THS  MANUFACTURE 

cutting  tools  have  been  made  from  it  of  the  beil 
quality.  This  alloy  is  perhi^  only  inferior  to  that 
of  steel  with  rhodium,  and  it  may  be  procured  at  a 
small  expense;  the  value  of  siher  where  the  pn^* 
portion  is  so  small,  is  not  worth  naming ;  it  intt 
probably  be  applied  to  many  important  purposes  \m 
the  arts  •*. 

^  The  alloys  of  steel  with  platinum,  when  both 
are  in  a  state  of  fusion,  are  very  perfect,  in  every 
proportion  that  has  been  tried.  Equal  parts  I7 
weight  form  a  beautiful  alloy,  which  takes  a  &at 
polish,  and  does  not  tarnish ;  the  colour  is  the  finest 
imaginable  for  a  mirror.  The  specific  gravity  of 
this  beautiful  compound  is  &'862. 

''  The  proportions  of  platinum  that  appear  to  tin* 
prove  steel  for  edge  instruments  ac^  from  1  to  3 
per  cent. ;  1  *5  per  cent,  will  probably  be  very  nearly 
right  ^ 

**  The  alloys  of  steel  with  rhodium  9xe  Kkely  to 
prove  highly  valuable.  The  scarcity  of  that  mdal 
must,  however,  operate  against  its  introduction  to 
any  great  extent.  This  aHoy  was  made  at  the  sug- 
gestion of  Dr.  Wollaston.  The  proportions  of  rho- 
dium used,  were  from  1  to  2  per  cent.  The  valu- 
able properties  of  the  rhodium  alloys  are  hardness, 
with  sufficient  tenacity  to  prevent  cracking  either 
in  forging  or  in  hardening.  This  superior  hardness 
is  so  remarkable,  that  in  tempering  a  few  cutdng 

**  Quarterly  Journal  of  Science,  vol.  ix.  page  326. 
^»  Ibid,  page  328. 


OF    FDGE   TOOLS.  o45 

articles  made  from  the  alloy,  tliev  required  to  be 
heated  full  3(f  of  Fahrenlieit  liigiier  tlian  tlie  best 
wootz,  woolz  itself  requiring  to  be  heated  full  40" 
above  the  best  Engtihli  cast-steel.  Thennoinetrical 
degrees  are  named,  that  being  the  only  accurate 
method  of  tempering  steel  '*'." 

"  Gold  forms  a  good  alloy  with  steel.  Experi- 
ence does  not  yet  enable  us,  say  they,  to  speak  of 
its  properties.  It  certainly  does  not  promise  to  be 
of  the  same  value  as  the  alloys  of  silver,  platinum 
and  rhodium  '"'." 

The  authors  conclude  this  valuable  paper  by 
observing  that,  "  from  the  facility  of  obtaining 
silver,  it  is  probable  that  its  alloy  with  steel  is  the 
most  valuable  of  those  we  have  made.  To  enu- 
merate its  applications  would  be  to  name  almost 
every  edge  tool.    It  is  also  probable  that  it  will 

prove  valuable  for  making  dies,  especidlly  when 
combined  with  the  best  Indian  steel  '"*." 

In  a  subsequent  paper  '*"  these  Experimentalists 
give  an  account  of  the  manufacture  of  the  alloys 
upon  a  larger  RCale.  In  these  experiments  they  dis- 
covered, with  regard  to  the  silver  alloy,  that  "  steel 
will  only  retain  one  iOOdth  part  in  union ;  when 
more  was  used,  it  either  evaporated,  or  separated 
as  the  button  cooled,  or  was  forced  out  in  forging. 
The  alloy  was  excellent,  and  the  trifling  addition 


100   Quarlertg  Journal  of  Science,  vol.  is.  pa^329. 
•"'  /fcirf.  page  329.  '"  iftirf.  page  329. 

""  FhilKHophu'il  Trantartiolu  for  the  yeur  1 822,  jmri  it,  pages 
253—270. 


546  ON  THE  MANUFACTURE 

of  price  furnishes  no  obstacle  to  its  general  em^ 
ployment,** 

'^  Steel  alloyed  with  the  lOOdth  part  of  platimis^ 
though  not  so  hard  as  the  silver  alloy,  has  moie 
toughness ;  hence  its  value,  where  tenaci^  as  well 
as  hardness  is  required :  the  extra  cost  is  mooe 
than  repaid  by  its  excellence. 

'^The  action  of  adds  on  these  allojrs  is  curioov 
and  especially  in  respect  to  that  of  platinuniy  wUdi 
is  acted  upon  by  diluted  sulphuric  acid  with  infi- 
nitely greater  rapidity  than  the  unalloyed  ataeL; 
indeed,  an  acid  that  scarcely  touches  the  pure  sted, 
dissolves  the  alloy  with  energetic  eflfervescenoe. 
This  is  probably  referable  to  electrical  excitatioa** 

It  is  remarkable  that  when  pure  iron  is  substi- 
tuted for  steel,  the  alloys  so  formed  are  mudi  leu 
subject  to  oxidation.  Hiree  per  cent,  of  iridimn 
and  osmium,  fused  with  some  pure  iron,  gave  a 
button,  which,  when  forged  and  polished,  was  ex- 
posed, with  many  other  pieces  of  iron,  steel .  and 
alloys*  to  a  moist  atmosphere ;  it  was  the  last  of  all 
showing  any  rust.  The  colour  of  this  compound 
was  a  distinct  blue'<^. 

Dr.  Brewster  states  that  Mr.  Stodart  favoured 
him  with  specimens  of  several  of  these  alloys  for 
optical  purposes ;  and  though  various  plates  of  po- 
lished steel  kept  beside  them  for  more  than  a  year, 
were  all  affected  with  rust,  yet  not  one  of  the  alloys 
had  suffered  the  least  change  '"\ 

'^  Quarterly  Journal  of  Science,  vol.  xiy.  pase  378. 

*^'  The  Edinburgh  Philosophical  Journal,  vol.  vii.  page  350. 


r 


OF  EDCE  TOOLS. 


So  important  were  these  discoveries  of  MesSrb, 
Stodart  and  Faraday  considered  in  France,  that 
"The  Society  for  the  Encouragement  of  National 
Industry"  directed  a  Special  Commission  to  repeat 
their  experiments  and  report  on  the  value  of  the 
several  alloys  which  they  had  descrihed.  This  Re- 
port was  printed  in  the  year  1821  and  is  highly 
flattering  to  our  English  Chemists"".  A  second 
Report  was  made  to  the  same  society  in  the  name 
of  the  Committe  of  Mechanical  Arts,  on  the  Steel 
Damasked  Blades  of  M,  Degrand-Gurgey  of  Mar- 
seilles, in  which  the  Committee  speak  of  *'  la  pr^- 
cieuse  d^couverte  de  MM.  Stodart  et  Fjiraday,"  and 
promise  at  some  future  time  to  repeat  all  tlie  expe- 
riments which  led  to  those  discoveries ;  especially 
those  whereby  our  countiymen  were  enabled  to 
give  to  steel  that  property  of  damasking  which  for- 
merly belonged  exclusively  to  the  Indian  wootz"". 
When  the  public  had  been  informed  of  the  suc- 
cess which  had  attended  the  experiments  of  Messrs. 
Stodart  and  Faraday,  M.  Berthier  was  induced  to 
try  the  effect  to  he  obtained  by  adding  a  portion  of 
chromium  to  steel.  "Two  alloys  of  cast-steel  and 
chromium  were  made,  one  with  O.Oi,  the  other 

'*  Rapport  fait  A  la  SociM  iC Encouragement  pour  Vtndut- 
trie  NationaU,  an  Nom  d'une  Commisiion  Sp/tHaU,  tar  let  Aaat 
Damast^  de  M.  Sir,  ffenry,  &e.  Par  M.  H^ricart  de  Thury. 
A'  Paris,  Quarto  1821. 

'"  Serond  Rapport  fait  li  la  Soci^li  d' Eacouragemenl  pour 
t'Induitrie  Nationate,  au  Noin  ilu  Com'U^  det  Arli  M^chaniqita, 
tUT  let  Lamfs  Damau^ei  de  M.  Degrand-Gurgey  de  Mar- 
uille.  Par  M.  Le  Vicomle  Hericart  de  Thury.  Quarto,  Pari* 
1821. 

2  N  S 


548  ON  THE  MANUFACTURE  OF  EDGE  TOOLS. 

with  0.015  of  chromium.  These,  he  says^  both 
forged  well,  the  first  better  than  cast-steel.  A  knife 
and  a  razor  were  made  from  them,  and  both 
proved  very  good ;  their  edges  were  hard  and  solid, 
but  their  most  remarkable  character  was  the  fine 
damask  they  took,  when  washed  over  with  sut 
phuric  acid.  This  damask  was  composed  of  white 
silvery  veins,  and  nearly  resembled  that  given  by 
the  alloy  of  steel  and  silver.  The  white  parts  are 
probably  pure  chromium,  on  which  acids  have  no 
action.  This  chromic  steel  was  prepared  by  fusing 
together  cast-steel  and  the  alloy  of  chromium  and 
iron  »«».- 


^  QuarterbfJournalof  Science, vo\.in.paige  174.    JmiaUt 
de  Ckimie  et  de  Phytiqite,  tome  xvii.  page  55. 


ESSAY  XVI. 


ON 


THE    MANUFACTURE 


TIN-PLATE. 


ESSAY    XVI. 


ON 


THE  MANUFACTURE  OF 


T  I  N-PL  ATE. 


[First  printed  in  the  Memoirs  of  the  Literaet  and  Philo- 
sophical Society  of  Manchester,  Vol.  III.  New  Series, 
and  copied  from  thence  into  the  Annates  de  Chimie  et  de 
Phytique,  tome  xii.  for  the  year  1819,  page  153.] 


As  the  processes  in  this  manufacture  are  more 
numerous  and  complicated  than  is  generally  ima- 
gined, it  may  be  advisable  to  preface  the  account 
with  an  enumeration  of  some  of  those  properties  of 
tin  which  will  be  most  likely  to  explain  the  ratio- 
nale of  the  principal  operations. 

Tin  has  a  great  affinity  for  several  of  the  other 
metals — particularly  for  zinc,  mercury,  copper, 
antimony,  lead  and  iron  ;  and  owing  to  these 
affinities,  its  employment  in  the  arts  is  very  con- 
siderable. 


552  ON  THE  MANUFACrrURE 

Tin,  with  zinc,  forms  a  metal  of  close  grain,  veiy 
useful  for  many  purposes,  especially  for  the  forma- 
tion o{  pewter.  The  zinc  is  found  to  impart  great 
hardness  to  the  tin,  without  lessening  its  ductility. 

The  combination  of  mercury  and  tin,  in  whidi 
the  tin  is  dissolved  by  the  mercury  into  a  very  goft 
amalgam^  is  largely  employed,  as  is  well  known, 
in  silvering  the  backs  of  mirrors,  and  for  other  pur- 
poses in  the  arts.  An  amalgam  of  tin  of  greater 
consistence  was  formerly  in  use  in  the  museuois  of 
Paris  for  closing  the  mouths  of  glass-bottles  con- 
taining sundry  curious  and  valuable  preparations. 

0>pper  is  also  alloyed  with  tin  for  various  pur- 
poses of  manufacture.  This  metallic  mixture  is 
employed  in  making  what  are  called  bronze  sta- 
tues ;  for  casting  bells,  and  pieces  of  artillery,  and 
also  for  the  fabrication  of  medals  and  medallions. 
In  some  of  these  cases  the  tin  is  mixed  with  copper, 
on  account  of  its  property  of  rendering  the  copper 
more  fusible;  and  this  was  probably  the  reason 
why  the  ancient  Romans  used  that  metal  in  the 
greater  part  of  their  brass  coinage.  It  is  owing  to 
the  affinity  of  tin  for  copper,  that  vessels  of  capia- 
city,  made  with  the  latter  metal,  for  culinary  and 
other  purposes,  are  so  readily  covered  with  a  coat- 
ing of  tin,  to  preserve  them  from  the  action  of 
substances  which  would  not  fail  to  erode  copper,  if 
unprotected  by  some  such  covering.  The  affinity 
of  tin  for  copper  is  further  exemplified  by  the  pro- 
cess of  whitening  pt7i6\  which  is  effected  by  boiling 


or  TIN  TLATF,.  553 

the  pins  with  granulated  tin  in  a  lie  made  with 
nluni  and  tartar'. 

An  useful  alloy  is  likewise  formed  by  the  mixture 
nf  tin  and  antimony.  This  metallic  compound  is 
very  white,  extremely  hard,  and  unll  bear  a  very 
fine  polish.  On  these  accounts  it  13  employed  in 
making  specula  for  telescopes,  and  also  for  the  ma- 
nufacture of  rolled  plates  to  engrave  music  upon. 

The  next  metal  which  I  have  mentioned  as  uni> 
ting  readily  with  tin,  is  lead.  This  metal  will 
combine  with  tin  in  any  proportion ;  and  in  most 
proportions  the  lead  acquires  a  greater  degree  of 
fusibility  by  its  union  with  the  tin.  It  is  this  allov 
which  forms  plumbers'  solder  ;  but  that  compound 
is  prepared  with  different  proportions  of  tin,  accord- 
ing to  the  purpose  for  which  it  is  intended.  The 
article  called  tin-foil,  used  for  lining  tea-cnddics, 
for  coating  electrical  jars,  and  for  other  purposes, 
is  also  made  from  a  mixture  of  these  two  metals. 

But  what  is  more  relevant  to  the  subject  of  this 
paper,  is  the  chemical  affinity  which  subsists  be- 
tween tin  and  iro?i.  One  of  the  strongest  proofs 
of  this  affinity  is  derived  from  the  circumstance 
that  even  casl-'non  may  be  tinned  in  the  same  man- 
ner as  wrought-iron.  Of  late  years,  cast-iron  sauce- 
pans, and  pots  of  a  large  size,  are  permanently  tin- 
ned on  their  inner  surfaces,  to  prevent  the  liquors 
which  arc  boiled  in  them  from  acquiring  any  stain 
by  a  partial  dissolution  of  the  iron.     Many  other 

'  An  int*ri'»ling  Memoir  (by  M.  GarfoUn)  on  ihc  Tinning  of 
common  Pina,  will  be  found  in  thr  Journal  de  Phi/rique,  1789. 


554  ON  THE  MANUFACTURE 

articles,  such  as  bridle^bits^  common  stirrups,  small 
nails,  &c.  are  now  made  much  cheaper  than  for* 
merly,  by  first  fabricating  them  in  cast-iron,  and 
then  covering  them  with  a  thin  coat  of  dn,  by  the 
immersion  of  them  in  a  hot  mass  of  that  metal  in 
a  $tate  of  fluidity. 

That  these  efiects  are  owing  to  chemical  affinity, 
cannot  be  doubted,  when  it  is  considered,  that  in 
all  these  cases  the  pores  of  the  iron  are  in  some 
degree  actually  penetrated  by  the  tin. 

In  the  manufacture  of  im^plate,  which  I  am  now 
about  to  describe,  a  similar  effect  is  produced,  and 
also  by  the  same  means.  Plates  of  iron  properly 
prepared,  are  immersed  in  a  large  mass  of  melted 
tin,  which  is  kept  hot  by  a  fire  constantly  burning 
underneath  it ; — the  consequence  of  which  is,  that 
the  tin  in  some  measure  penetrates  the  iron,  and 
this  attaches  other  tin  to  it,  so  that  the  whole  sur* 
face  of  the  iron  acquires,  by  this  means,  a  complete 
covering  of  that  metal. 

As  no  accurate  account  has  ever  yet  been  given 
of  the  various  processes  by  which  this  is  effected, 
the  following  outline  may  probably  be  acceptable 
to  the  public. 

English  bar-iron  of  the  finest  quality,  called  tin* 
iron,  and  which  is  generally  prepared  with  cAarcoat 
instead  of  mineral  coke,  and  made  with  the  great- 
est care,  for  this  particular  purpose,  is  first  cut  to 
the  necessary  length,  and  then  rolled  at  the  mill, 
by  a  process  which  is  peculiar  to  this  manufacture. 


OF  TIN  PLATE.  655 

into  plates  of  the  requisite  thirnifss,  and  of  such 
fomi  &s  is  suitable  for  the  business.  These  plates 
are  then  cut  by  hand-shears  to  the  sizes  suitable  for 
the  different  markets  *.  And  as  the  shearer  shears 
the  plates,  he  piles  them  in  heaps,  occasionally 
putting  one  plate  the  cross  way,  to  keep  each  box 
separate.  Two  hundred  end  twenty-five  plates  are 
called  a  box ;  but  they  are  not  put  into  boxes  of 
wood  in  this  stage  of  the  operation.  The  iron 
plates  now  go  into  the  hands  of  the  sca/cr,  who 
takes  them  from  the  shear-house,  and  bends  each 
of  them  singly  across  the  middle,  into  this  form  A  , 
preparatorj'  to  their  being  cleaned  for  tinning,  and 
for  the  conveniency  of  putting  them  into  the  scaling 
furnace,  as  will  be  more  fully  explained  hereafter. 

This  furnace,  or  oven,  is  heated  by  flame  thrown 
into  it  from  a  hr6-pla0e  of  a  peculiar  construction  ; 
ajid  it  is  this  flame  that  scales  the  plates,  which  are 
put  into  the  oven  in  rows,  and  arranged  three  in 
each  row,  until  the  oven  is  full.  It  will  be  obvious 
that  if  they  lay  flat  on  the  floor  of  the  oven,  the 
flame  could  play  only  on  one  side  of  each  plate, 
whereas,  by  being  bent  in  the  form  already  de- 
scribed, the  flame  can  operate  equally  on  both  sides. 
It  may  here  be  remarked  that  the  form  of  all  tin- 
plates,  one  sort  excepted,  is  that  of  a  parallelogram, 
and  that  if  a  piece  of  stiff  paper,  or  pasteboard, 

^  These  plates  arc  generally  cut  ti/  hitnd  -,  but  an  ingeniom 
whitesmilh  in  GlamorganKbirc  n  few  years  ago  invented  a  me- 
thod of  shearing  them  by  'i  machine.  This  machine  is  worket) 
by  a  water-whccl,  anil  will  shear  100  boxes  per  day  ;  whereas 
a  hnnd-shcnrrr  cannot  complete  more  than  25  boxes  in  the 
Munc  pcriotl  of  tiiQc,  .  1<  <         • 


656  ON  THE  MANUFACTURE 

13f  inches  long,  and  10  inches  wide,  be  bent  in 
the  centre  at  an  angle  of  about  sixty  degrees,  and 
then  put  to  stand  on  the  two  ends,  we  shall  have 
the  form  of  a  plate  No.  1 .  properly  bent  for  the 
scaling  oven. 

The  operation  of  cleansing^  as  it  is  called,  and 
which  is  preparatory  to  the  process  of  scaling  is 
commenced  by  steeping  the  plates  for  the  space  ci 
four  or  five  minutes,  in  a  mixture  of  muriatic  add 
and  water,  in  the  proportion  of  four  pounds  of  add 
to  three  gallons  of  water.  This  quand^  of  the 
diluted  acid  will  generally  be  sufficient  for  eighteen 
hundred  plates,  or  eight  boxes  of  225  plates  eadi. 

When  the  plates  have  been  steeped  for  the  time 
prescribed,  they  are  taken  out  of  the  liquor,  and 
placed  upon  the  floor,  three  in  a  row,  and  then  by 
means  of  an  iron  rod  put  under  them,  they  are 
conveyed  to  a  furnace  heated  red-hot,  where  they 
remain  until  the  heat  takes  off  the  scale,  the  re- 
moval of  which  was  the  object  in  submitting  them 
to  that  high  temperature. 

When  this  is  effected,  the  plates  are  taken  to  a 
floor,  where  they  are  suffered  to  cool ;  they  are  then 
straightened,  and  beaten  smooth  upon  a  cast-iron 
block.  The  workman  knows  by  the  appearance  of 
the  plates  during  this  operation,  whether  they  have 
been  well  scaled  ;  for  if  they  have,  that  is,  if  the 
rust  or  oxide  which  was  attached  to  the  iron  has 
been  properly  removed,  they  will  appear  mottled 
with  blue  and  white,  something  like  marbled  paper. 
The  operation  that  we  have  now  been  describing 
is  called  scaling. 


OF  TIN  PLATE.  557 

As  it  is  impossible  the  plates  can  go  tlirougli 
this  process  without  being  in  some  measure  warped, 
or  otherwise  disfigured ;  they  are  now  rolled  a  second 
time,  between  a  pair  of  cast-iron  rollers,  properly 
hardened  and  finely  polished.  This  operation  makes 
both  sides  of  the  plates  perfectly  smooth,  and  im- 
parts a  sort  of  polish  to  their  surfaces.  These 
rollers  are  each  about  17  inches  long,  and  12  or  13 
inches  in  diameter ;  but  I  am  inclined  to  think 
that  if  the  diameter  was  greater ',  they  would  set 
the  plates  flatter,  and  do  the  work  better  in  every 
respect. 

The  technical  name  of  this  apparatus  is  roiis, 
not  rollers.  All  the  rolls  which  are  employed  in 
rolling  plates,  either  hot  or  cold,  in  this  manufac- 
tory, are  A«rrf  rolls  ;  and  there  is  as  much  difference 
between  a  pair  of  hard  cast-iron  rolls,  and  a  pair  of 
so/i  rolls,  although  they  may  both  be  run  out  of 
the  same  pot  of  metal,  as  there  is  between  iron  and 
steel,  Ttie  workmen  inform  me  that  the  difference 
is  entirely  occasioned  by  the  manner  of  casting 
them — tlie  soft  rolls  being  cast  in  aand,  whereas 
the  hard  rolls  are  formed  by  pouring  the  metal  into 
a  thick  cast-iron  box — and  that  the  metal,  by  coming 
in  contact  with  the  cold  box  is  sufficiently  chilled 
to  render  the  whole  face  of  the  roll  entirely  hard. 
The  difference  in  the  temper  of  these  two  kinds  of 


^  Since  tVic  above  was  written,  I  have  submitted  the  manu- 
kcript  to  a  gentleman  who  i*  very  largely  engaged  in  the  manu- 
fiicture  of  tm-pUtM,  and  he  telU  mc  that  the  cold  rolls  which 
»n  employed  in  hii  work,  are  30  incites  in  diameter. 


558  ON  THE  MANUFACTURE 

rolls  18  SO  great,  that  when  diey  are  put '  into  the 
lathe  to  be  turned  perfectly  true,  the  turnings  fram: 
the  one  will  be  ^th  of  nn  inch  in  thickness,  wbilst, 
the  turnings  which  come  from  the  odier  are  not 
larger  than  very  fine  needles.  The  temper  of  cast- 
iron  thus  varying  acootding  to  the  nature  of  the 
mould  into  which  it  is  poured,  is  a  circumstance 
that  appears  to  me  to  be  deserving  of  attention  in 
the  manufacture  of  a  varie^  of  other  utensils  em^ 
ployed  in  the  arts*. 

These  rollers  are  used  without  heat;  but  they  are- 
screwed  down  very  close  one  upon  the  other,  onty 
leaving  bare  room  for  the  plates  to  pass,  that  the 
utmost  attainable  degree  of  pressure  may  be  gi^nsir 
to  them.       This  last  operation  is  called  cour 

ROLLING. 

When  the  plates  have  undei^one  this  praeess^ 
they  are  put  one  by  one  into  troughs  filled  with  a 
liquid  preparation  called  the  ties. 

This  is  merely  water  in  which  bran  has  been 
steeped  for  nine  or  ten  days  until  it  has  acquired 
a  sufficient  acidity  for  the  pitrpose.  The  design  of 
putting  the  plates  into  the  troughs  singly^  is,  that 
there  may  be  more  certainty  of  the  liquor  getting 

*  The  art  of  making  good  hard  rolls  appears  to  be  very  im- 
perfectly understood^  b^use  the  difficult^  of  producing  them 
18  very  great.  Not  one  in  three  can  be  caUed  thoroughly  good. 
For^  if  they  are  not  sufficiently  hardened  on  the  surface,  they 
will  not  wear ;  whereas,  if  they  are  made  hard  throughout,  or 
struck  hard  to  the  centre^  as  the  workmen  call  it,  they  wfll  gene- 
rally crack  across  the  middle  and  become  useless.  This  fault 
is  quite  independent  of  air  bubbles  or  flaws,  which  are  always 
discoverable  in  turning  by  the  lathe. 


OF  TIN   PLATE. 


559 


between  them,  and  both  the  sides  of  every  plate 
being  soaked  alike  in  tlie  lies.  In  this  liquor  they 
remain  for  ten  or  twelve  hours  standing  on  the 
edges ;  but  they  are  turned,  or  inverted,  once  during 
that  time.  This  operation  is  called  working  in  the 
lies. 

The  next  operation  is  that  of  steeping  in  a  mix- 
ture  of  sulphuric  acid  and  water,  in  proportions 
which  vary  according  to  the  judgement  of  the  work- 
men. 

The  trough  in  which  this  operation  is  conducted, 
is  made  with  thick  lead,  and  the  interior  is  divided 
by  partitions  of  lead.  Each  of  these  divisions  is  by 
the  workmen  called  a  hule,  and  each  of  them  will 
contain  about  one  box  of  plates.  In  the  diluted 
sulphuric  acid  which  is  in  the  different  compart- 
ments of  this  vessel,  the  plates  are  agitated  for  about 
an  hour,  or  until  they  have  become  perfectly  bright, 
and  entirely  free  froTii  the  black  spots  which  are 
always  upon  tbem  when  they  are  first  immersed  in  it. 

Some  nicety  however  is  required  in  this  opera- 
tion ;  for,  if  they  remain  too  long  in  the  acid,  they 
will  become  stained,  or  blistered  by  it,  as  the  work- 
men term  it;  but  practice  enables  a  careful  ope- 
rator to  judge  of  the  time  when  they  ought  to  be 
removed.  This,  however,  is  one  of  the  most  diffi- 
cult parts  of  the  business,  as  few  men  like  to  work 
in  it ;  though  I  understand  that  a  good  pickler  is 
highly  valued  by  his  employers,  and  obtains  great 
wages.  It  is  necessary  to  notify  that  this,  and  the 
former  process  Hith  tlte  acidulated  water,  are  both 


560  ON  TH£  MANUFACTURE 

hastened  by  giving  to  those  menstrua  an  increase 
of  temperature ;  and  •  this  is  effected  by  means  of 
heated  flues  which  run  under  each  trough.  little 
additional  heat  is  necessary  in  summer,  however, 
as  90^  or  100^  of  Fahrenheit  is  a  temperature  suf- 
ficiently high  for  either  of  these  operations. 

When  the  plates  come  out  of  the  pickle,  they 
are  put  into  pure  water,  and  scoured  in  it  with  hemp 
and  sand,  to  remove  any  remaining  oxide,  or  rust 
of  iron  that  may  be  still  attached  to  them ;  for, 
wherever  there  is  a  particle  of  rust  or  even  Atsi 
upon  them,  there  the  tin  will  not  fix ;  and  they  arr 
then  put  into  fresh  water  to  be  there  preserved  for 
the  process  of  tinning.  The  design  of  putting  the 
plates  into  pure  water,  after  they  come  out  of  the 
sours,  is  to  prevent  their  becoming  again  oxidised ; 
for  it  has  been  found  that  after  these  operationt 
they  will  acquire  no  rust,  although  they  should  be 
kept  twelve  months  immersed  in  water. 

It  will  be  perceived  that  all  these  processes  are 
nothing  more  than  preparatory  measures  for  the  ope- 
ration which  is  to  succeed,  viz.  that  of  tinning. 

For  this  purpose  an  iron  pot  is  nearly  filled  with 
a  mixture  of  block  and  grcnn  tin,  in  a  melted  state ; 
and  a  quantity  of  tallow  or  grease,  sufficient,  when 
melted,  to  cover  the  fluid  metal  to  the  thickness  of 
four  inches,  is  put  to  it.  However,  as  some  per- 
sons  may  not  be  acquainted  with  the  difference 
between  block  and  grain  tin,  it  may  be  remarked, 
before  we  proceed,  that  the  metal  known  in  com- 
merce by  the  name  of  block  tin,  is  prepared  eitlter 


OV  TIN   I'LATE,  501 

from  the  mineral  called  tin-stone,  or  tlie  one  known 
in  Cornwall  by  the  name  of  tin-pyrites,  whilst  the 
article  called  grain  tin  is  .smelted  from  an  ore  which 
is  found  in  grains,  called  stream  tin  ore,  imder  beds 
of  alluvial  soil,  in  low  situations,  whither  in  the 
course  of  ages  it  has  been  washed  from  the  hills 
by  a  succession  of  torrents  of  rain.  The  former, 
which  is  produced  in  the  grtntest  abundance,  is 
always  contaminated  wltli  a  portion  of  iron,  sul- 
phur, and  otlier  injurious  substances,  and  is  there- 
fore only  employed  for  common  purposes ;  while 
the  grain  tin,  which  is  nearly  free  from  every  im- 
purity, and  usually  from  twenty  to  thirty  shillings 
per  hundred  weight  dearer,  is  used  in  many  pro- 
cesses of  dyeing,  and  in  all  other  cases  where /«rtr 
tin  is  required.  I  am  also  desirous  of  remarking, 
that  in  my  opinion  it  would  be  more  protitahte  to 
the  proprietor  of  a  tin-plate  work,  if  he  were  to  use 
grain  tin  alone,  or  grain  tin  mixed  with  that  kind 
which  is  known  by  the  name  of  "  Refined  Tin," 
because  these  kinds  not  only  contain  less  dross,  but 
they  melt,  as  I  know  by  my  own  experience,  into  a 
more  fluid  metal ;  and  consequently,  nmre  would 
run  off  the  plates  in  the  operation  of  tinning,  and 
less  tin  would  be  consumed.  At  present  these 
manufacturers  use  the  block  and  grain  tin,  in  equal 
proportions. 

When  the  tin-pot  has  been  charged  in  the  way 
above  mentioned,  the  metal  is  heated  from  a  fire- 
place underneath  it,  and  by  fines  which  go  round 

VOL,  II.  2  o 


562  ON  THE  MANUFACTURE 

the  pot,  until  it  is  as  hot  as  it  can  be  made  widi- 
out  actually  inflaming  the  grease  which  siprims  upon 
its  surface.  The  use  of  the  grease  is  te  preserve 
the  tin  from  the  action  of  the  atmosphere,  and  coo* 
seijuently  to  prevent  it  from  oxidizing.  By-  mdlii^ 
a  little  tin  or  lead  in  an  iroii  ladl^  and»  when  the 
dross  is  skimmed  off,  putthig  *  a  morsd  of  Uiiait 
iqpon  the  metallic  fluid,  the  efiiect  of  the  tallow  ia 
deansing  the  face  of  the  metal:  will  be  evident.  Hit 
workmen  also  say,  that  it  increases  the  afl&nity  iif 
tfyeiron  for  the  tin,  or,  as  they  exjMress  it,  that  it 
makes  the  iron  plates  take  the  tin  better.  ^' 

It  is  curious  that  burnt  grease^  or  any  kind  of 
empyreumatic  fat,  effects  this  purpose  better  tlita 
pure  fipesh  tallow. 

r  Another  pot,  which  is  fixed  by  the  side  of  the 
tin-pot,  is  filled  with  grease  only ;  and  in  this  the 
prepared  plates  are  immersed,  one  by  one,  befoif 
they  are  treated  with  the  tin ;  and  when  the  pot  is 
filled  with  them,  they  are  suffered  to  remain  in  il 
so  long  as  the  superintendant  thinks  necessary.  If 
they  remain  in  the  grease  an  hour,  they  are  found 
to  tin  better  than  when  a  shorter  time  is  allowed 
them. 

'  Ftom  this  pot  they  are  removed,  with  the  grease 
^tlU  adhering  to  them,  into  the  pot  just  before 
spoken  of,  which  contains  the  body  of  melted  tin ; 
and  in  this  they  are  placed  in  a  vertical  position. 
Three  hundred  and  thirty-eight  or  three  hundred 
lind  forty  plates  are  usually  put  into  this  pot  at 


OF  TIN  PLATE. 


56:i 


once';  and  for  the  sake  of  their  being  tlioroughly 
tinned,  tbey  usually  remain  in  it  one  hour  and  a 
half;  but  occasionally  more  time  is  required  to 
complete  this  operation. 

When  the  plates  have  lain  a  sufficient  time  im- 
mersed in  the  melted  tin,  they  are  taken  out  and 
placed  upon  an  iron  grating,  that  the  superfluous 
raetal  may  drain  from  them;  but,  notwithstanding 
this  precaution,  when  they  become  cold  there  is 
always  more  metal  found  adhering  to  them  than  is 
necessary;  and  this  is  taken  off  by  a  subsequent 
process  called  was/ting.  As  this  process  is  rather 
complicated,  it  will  be  necessary  to  describe  it  with 
some  minuteness. 

In  the  iirst  place,  the  wash-man  prepares  an  iron 
pot  which  he  nearly  fills  with  the  best  grain  tin  in 
a  melted  state — another  pot  of  clean  melted  tallow, 
or  lard  free  from  salt — a  third  pot  with  notliing 
witliin  it  but  a  grating  to  receive  tlie  plates — and 
a  fourth,  called  the  Hsting-pot,  with  a  little  melted 
tin  in  it,  about  enough  to  cover  the  bottom  to  the 
depth  of  a  quarter  of  an  inch.  The  whole  will 
however  be  better  understood  by  referring  to  the 
following  drawing,  which  exhibits  tlie  several  vessels 


'  It  ii  immaterial  how  many  plates  xn  put  into  the  lin-pot 
at  once — but  this  number  n  luually  fixed  upon,  because  it 
aroounts  to  Fibout  one  box  ami  a  half  of  pistes  :  though,  as  they 
are  mil  in  edgewise,  it  is  necessary  the  pot  sliould  be  nearly 
filled,  to  prevent  their  falling  down — in  which  case  they  coul^ 
not  be  got  out,  through  so  heavy  a  body  of  metal,  without  much 
difficulty. 


k 


2o2 


664 


ON  THB  MANUFACTURE 


iti  the  order  in  which  they  stand  in  the  maoa- 
fitctory,  all  supported  by  lubstaptial  bridC-worii. 


The  building  in  which  the  pots  are  fixed  is  called 
the  Stow.     The  plates  are  worked  from  the  right 
to  die  left  of  the  stow,  as  will  be  evident  by  attend- 
ing  to  the  uses  of  the  separate  pots. 
,        No.  1.  represents  the  tin-pot. 

2.  The  wash-pot  with  the  parUng  within  it. 

3.  The  grease-pot. 

',  4.  The  pan,  conUuning  a  grating  at  the 
bottom*.  <■ 

^'  ■-'■'    5.  The  list-pot. 

The  drawing  represents  the  surface  of  the  pots. 
The  asterisks  show  the  places  where  the  workmai 
stand,  and  also  mark  those  pots  which  have  heated 
flues  under  them.     No.  4  has  no  fire  under  it. 


*  This  pan  is  designed  for  the  reception  of  the  plates  as  die 
boy  takes  them  out  of  the  greaiie-pot.  It  hat  no  fire  under- 
neath it. 


OF  TIN  PLATE.  566 

The  parting  in  the  wash-pot  No.  2  is  a  late  im- 
provement. The  design  of  it  is  to  keep  the  dross 
of  the  tin  from  lodging  in  that  part  of  the  vessel 
where  the  last  dip  is  given  to  the  plates.  By  using 
the  common  tin  in  the  first  process  of  tinning,  much 
oxide,  or  dross,  adheres  to  the  surface  of  the  plates, 
and  this  runs  off  in  the  wash-pot,  and  comes  to  the 
face  of  the  new  metal ;  but  this  parting  enables  the 
operator  to  prevent  it  from  spreading  over  the 
whole  surface  of  the  pot.  Were  it  not  for  this 
parting,  the  wash-man  must  skim  the  oxide  off  the 
fluid  metal  every  time  he  puts  plates  into  it. 

The  pots  of  which  I  have  given  a  sketch  being 
all  in  a  state  of  fitness,  the  wa^h-man  commences 
his  part  of  what  remains  of  the  business,  by  putting 
the  plates  which  have  undergone  the  various  ope- 
rations hitherto  described  into  the  vessel  of  grain- 
tin,  called  the  wash-pot'.  The  heat  of  this  large' 
body  of  melted  metal  soon  melts  all  the  loose  tin 
on  the  surface  of  these  plates,  and  so  deteriorates 
the  quality  of  the  whole  mass,  that  it  is  usual,  when 
sixty  or  seventy  boxes  have  been  washed  in  the 
grain  tin,  to  take  out  the  quantity  of  a  block,  say 
three  hundred  weight,  and  replenish  the  wash-pot 
with  a  fresh  block  of  pure  grain-tin.  These  ves- 
sels generally  hold  three  blocks  each,  or  about  half 


'  None  but  grain-lin  is  ever  put  into  this  vessel  ;  for  the 
wtiole  of  the  common  dn  which  is  consumed  in  such  manu- 
ftictoriee,  is  used  in  the/rif  process,  viz.,  that  which  is  called 


r 


9K  ON  THE  MANUFACTURE 

a  ton  weight  of  metal.  That  which  is  taken  out 
of  the  wash-pot  when  it  is  replenished  with  pure 
metal,  is  given  to  the  tin*man  to  put  into  his  pot. 

When  the  plates  are  taken  out  of  the  wash-pot, 
they  are  carefully  brushed  on  each  side  with  a  brush 
of  hemp  of  a  peculiar  kind,  and  made  expressly  for 
the  purpose.  As  this  part  of  the  business  requires 
considerable  adroitness  and  expedition,  it  may  be 
worth  while  to  explain  it  a  little  more  in  detail. 

The  wash-man  first  takes  a  few  plates  out  of  tlie 
wash-pot,  and  lays  them  together  before  him  on 
the  stow  ;  he  then  takes  one  plate  up  with  a  pair 
of  tongs,  which  he  holds  in  his  left  baiMl,  and  with 
a  brush  held  in  his  right  hand  brushes  one  side  of 
the  plate ;  he  then  turns  it,  and  brushes  the  other 
side,  and  immediately  dips  it  once  more  into  the 
hot  fluid  metal  in  the  wash-pot,  and  without  letting 
it  out  of  the  tongs  instantly  withdraws  it  again, 
and  plunges  it  into  the  grease-pot  (marked  No.  3) 
adjoining  to  the  wash-pot  from  whence  he  had  just 
taken  it. 

A  person  who  has  not  seen  the  operation,  can 
form  but  a  very  inadequate  idea  of  the  adroitness 
with  whicl)  this  is  performed :  practice,  howeTer, 
^ves  the  workman  so  much  expedition,  that  he  is 
enabled  to  make  good  wages,  although  he  obtains 
only  three-pence  for  the  brushing  and  metallic- 
washing  of  225  plates.  I  am  informed  that  an 
expert  wash-man,  if  he  makes  the  best  of  his  time, 
will  wash  25  boxes,  consisting  of  5625  plates,  in 


OK  TEN  PLATE.  56/ 

twelve  hours ;  notwithstanding  every  plate  must  be 
brushed  on  both  sides,  and  dipped  twice  into  the 
pot  of  melted  tin. 

Why  the  plates  should  be  dipped  twice  during 
this  part  of  their  manufacture,  may  perhaps  require 
some  explanation.  It  must  be  recollected  that 
they  are  brushed  quite  hot,  and  before  the  tin  is 
set;  therefore,  if  they  had  not  the  last  dip,  the  marks 
of  the  brush  would  be  visible.  Moreover,  the 
brush  takes  the  greatest  part  of  the  tin  off  them, 
so  that  if  they  were  removed  to  the  grease-pot  with> 
out  being  re-dipped,  the  hot  grease  would  take  off 
what  remained. 

The  only  use  of  the  grease-pot  is  to  take  off  any 
superfluous  metal  that  may  be  upon  the  plates: 
but  this  is  an  operation  that  requires  great  atten- 
tion, because,  as  the  plate  is  immersed  in  the  grease 
while  the  tin  is  in  a  melting,  or  at  least  in  a  soft, 
state  upon  it,  a  part  rnust  run  off,  and  tlie  remain- 
der become  less  and  less  while  the  plate  continues 
in  it;  therefore,  if  these  plates  should  ever  be  left 
in  the  melted  tallow  longer  than  is  absolutely  neces- 
sary, they  will  doubtless  require  to  be  dipped  a 
third  time  in  the  tin.  On  the  other  hand,  if  the 
plates  were  to  be  finished  without  passing  through 
the  grease,  they  would  retain  too  much  of  the  tin, 
which  would  be  a  loss  to  tlie  manufacturer;  and 
besides,  the  whole  of  the  tin  would  appear  to  be  in 
waves  upon  the  iron. 

It  is  abo  equally  necessary  to  attend  to  the  tem- 
perature of  the  melted  tallow,  which  must  be  colder 


ON  THE  MANUFACTURE 

or  bo'tter  in  proportion  as  the  plates  are  thicker  or 
thinner ;  for  if,  when  the  tallow  is  of  a  proper  tem- 
perature for  a  thin  plate,  a  thick  one  was  to  be  put 
into  it,  it  would  come  out,  not  of  the  colour  of  tin 
as  it  ought  to  be,  but  as  yellow  as  gold.  The 
reason  of  this  is  evident.  Tlie  thick  plate  contains 
more  heat  than  a  thin  one,  and  consequently  re- 
quires the  tallow  to  be  at  a  lower  temperature.  On 
the  contrary,  if  a  parcel  of  thin  plates  were  to  be 
worked  in  a  pot  of  tallow  which  had  been  prepared 
for  thick  plates,  such  a  pot  would  not  be  hot  enough 
to  effect  the  intended  purpose. 

It  is  a  common  observation  that  in  most  of  our 
manufactures,  and  in  all  chemical  specuUtions, 
theory  and  practice  are  generally  at  variance;  but 
there  are  few  manufactures,  perhaps,  where  there  are 
so  many  minutia  which  would  escape  the  notice 
of  a  casual  observer,  and  yet  that  require  to  be 
carefully  attended  to,  in  order  to  produce  a  good 
result,  as  inthat  which  we  have  now  been  describing; 
and  should  the  perusal  of  this  paper  occasion  but 
one  individual  to  pause,  who  was  about  to  enter 
into  a  new  concern  with  which  he  was  only  pnrtialljri 
acquainted,  I  shall  have  written  to  a  good  purpose. 

But  to  return  to  the  process.  When  the  ulutes 
are  sufficiently  brushed,  they  are  again  iinm* 
one  by  one  in  t'  ,1  ■  ■  f  i  lu  i  ;i  ,,  as  hu  alrad/j 
been  remarktil  u  thk  tht^are 

put  into  tlif  |U'  ■  M.ir**-  ' 

pot   liri-      ■  > 

to     p.'.   > 


OF  TIN  I'LATE.  &Si) 

and  this  part  of  the  process  is  conducted  in  the 
following  manner  : 

When  tile  wash-man  has  passed ^w  of  the  plates 
through  the  melted  tin,  and  from  thence  into  the 
pot  of  tallow  above  mentioned,  a  boy  takes  out  one 
of  them  and  puts  it  into  the  empty  pot  to  cool, 
and  the  wash-man  puts  in  the  sixth  plate.  The 
boy  then  takes  out  &  second  plate,  and  lays  it  to 
cool  likewise;  when  the  man  puts  in  his  seventh, 
and  so  they  go  on,  in  this  regular  manner,  until 
the  whole  of  the  parcel  is  finished. 

In  consequence  of  the  plates  being  immersed  ia 
the  melted  tin  in  a  vertical  position,  there  is  always, 
when  they  have  become  cold,  a  wire  of  tin  on  the 
lower  edge  of  every  plate  which  is  necessary  to  be  re- 
moved, and  this  is  done  by  a  boy,  called  the  list- 
boy,  who  takes  tlie  plates  when  they  are  cool  enough 
to  handle,  and  puts  the  lower  edge  of  each,  one  by 
one,  into  the  list-pot,  which  is  the  vessel  that  was 
before  described,  as  containing  a  very  small  quantity 
of  melted  tin,  and  the  same  as  that  which  I  have 
marked  No.  5.  When  the  wire  of  tin  is  melted 
by  this  last  immersion,  the  boy  takes  out  the  plate, 
and  gives  it  a  smart  blow  with  a  thin  stick,  which 
disengages  the  wire  of  superfluous  metal,  and  this 


MUn^  oO.  1. 

jitvrs  only  a  faint  stripe  in  the  place 

whf.' 

'i.(i.     This  mark  may  be  dts- 

cuvtr> 

[)la       -'lich  is  exposed  for  sale; 

the  ■ 

■pjl^             !ture  of  them,  call  it 

.he       y 

IB^I 

^^^^1             to  cleanse  the  plates 

570  ON  THE  MANUFACTURE 

beta  the  tallcnr.  This  is  done  by  means  of  bran, 
and  as  they  are  cleansed  they  are  put  into  MnNig 
wooden  boxes,  or  bDxes  of  skeet-iroHt  made  exactly 
to  fit  them ;  and  this  oompletes  the  wbc^  biuincwai 
Bach  box  contuns  a  determinate  numba  of  plates] 
and  the  following  table  will  show  the  different  siiia 
of  tin  plate  whi<ji  are  made  in  Great  Aitiun,  aod 
the  marks  by  which  each  kind  is  known  in  cooh 


Common.. 
Do ... . 


.No.  1 


Do 

.  Chwi No. 

Two  Cross 

Three  Cross 

Four  Crow    

CoramoD  Doubles 

Cross  Doubles 

Two  Cross  do. , ,  . , , 

Three  Cross  do 

Four  Cross  do 

Com.  small  Doubles. 

Cross  do do. . 

Two  Cross. . . .  do. . 

■Piree  do do.  . 

Four   do do. . 

Wasters  Com.    No. 
Cross 


Inch 
13iby  10 
13]  W  94 
12}  by  9i 
13j  l^  10 


16Jbyl24 


I3jby  10 
13}  l^  10 


21 ! 


of  TIN  PLATE. 


371 


A  Lilt  oflhf  Current  H'bttltiaU  Pricet  of  Tm-Plale  in  Lnndon. 


CNo.  I.  .. 
C  2.  .. 
C  3.  .. 
X  No.  I .. . 
XX  I.  .. 
XXX  1.  .. 

CD  

XD  

XXD 

XXXD  .... 

CSD 

XSD 

XXSD  .... 
Wasters  CI 
Do.  XI  ... . 


WeigbU       emchBol 


Sept-lStT 


170|-1 
191   >2( 
2I2IJ 

143  J  ^■ 


73II  '• 


Having  given  so  detailed  an  account  of  the  manu- 
facture of  tin-jilate,  it  may  be  expected  that  I  should 
say  a  few  words  on  the  origin  of  the  art. 

Formtrly  none  of  the  Englisih  workers  in  iroD  or 
tin  had  any  knowledge  whatever  of  the  methods  hy 
which  this  useful  article  could  be  produced;  our 
ancestors,  from  time  immemorial,  having  supplied 
themselves  with  it  from  Bohemia  and  Saxony.  The 
establishment  of  this  manufacture  in  those  districts, 
was  doubtless  owing  to  their  vicinity  to  the  tin 
mines  in  the  circle  of  Brsgebirg,  which,  next  to 
those  of  Cornwall,  are  the  largest  in  Europe.  The 
ore  which  is  found  there  is  not  the  tin-pyritca,  but 


57*2  ON  THE  MANUFACTURB 

the  mineral  called  tin^stone ;  and  it  is  carious  that 
it  should  occur  in  abundance,  both  on  the  Bohe- 
mian and  Saxon  sides  of  the  mountain  group: 
accordingly,  manufactories  of  tinned  iron  have  been 
established  in  both  those  kingdoms.  Alluvia^ 
deposits  of  grain-tin  are  also  found  in  the  same  vi- 
cinity. 

From  the  time  of  the  invention  of  tin-plate  to 
the  end  of  the  seventeenth  century,  not  only  Eo- 
gland  but  also  the  whole  of  Europe  depended  upon 
the  manufactures  of  Bohemia  and  Saxony  for  their 
supply.  However,  about  the  year  1 665  Mr.  Andrew 
Yarranton,  encouraged  by  some  persons  of  property, 
lindertook  to  go  over  to  Saxony  to  acquire  a  know- 
ledge of  the  art ;  and  on  his  return,  several  parcek 
of  tin-plate  were  made  of  a  superior  quality  to  those 
which  we  had  been  accustomed  to  import  from 
Saxony ;  but  owing  to  some  unfortunate  and  un- 
foreseen circumstances,  which  are  all  detailed  by 
Mr.  Yarranton  in  his  very  valuable  publication*, 
the  manufactory  was  not  at  that  time  established  in 
any  part  of  Great  Britain. 

As  it  is  now  difficult  to  procure  a  copy  of  the 
work  from  which  I  have  obtained  a  knowledge  of 
the  manner  in  which  this  manufactory  was  brought 
into  England,  an  abridgement  of  the  author's  own 
account  of  the  transaction  will  probably  be  interest- 
ing to  the  public. 

■     ■  ■  ■■■^ 

• 

*  England* s  Improvement  by  Sea  and  Land,  with  many  plates 
of  Plans,  Charts,  &c.  in  two  parts,  by  Andrew  Yarranton,  Gent. 
Part  I.  Quarto.  London^  1677.  Part  II.  London,  1681. 


OF  TIN  PLATE.  573 

"Knowing,"  says  Mr.  Y'arranlon,  "  the  useful- 
"  ness  of  tin-plates,  and  the  goodness  of  our  metals 
'*  for  that  purpose,  I  did  (about  sixteen  years  since') 
"endeavour  to  find  out  the  way  for  making  there- 
"  of;  whereupon,  I  acquainted  a  person  of  much 
"  riches,  and  one  that  was  very  understanding  in 
"the  iron  manufacture;  who  was  pleased  to  say, 
"  tliat  he  had  often  designed  to  get  the  trade  into 
'*  England,  but  never  could  find  out  the  way.  Upon 
"  which  it  was  agreed,  that  a  sum  of  monies  should 
"  be  advanced,  by  several  persons,  for  the  defraying 
"  my  charge  of  travelling  to  the  place  where  these 
"plates  were  made;  and  from  thence  to  bring 
"  away  the  art  of  making  them.  Upon  which,  an 
"  able  fire-man,  that  well  understood  the  whole 
"  nature  of  iron,  was  made  choice  of  to  accompany  ' 
"  me ;  and  being  fitted  with  an  ingenious  inter' 
"  preter,  that  well  understood  the  language,  and 
"  that  hud  dealt  much  in  that  commodity,  we 
"marched  first  for  Hamburg,  tlien  to /-i/^aWc/- ; 
"  and  from  thence  to  Dra'isdai,  the  duke  of  Aax- 
"  allies  Court,  where  we  had  notice  of  the  place 
"  where  the  plates  were  made;  which  was  in  a  large 
"  tract  of  mountainous  land,  running  from  a  place 
"called  Seger-Hvtton,  unto  a  town  called  j-Iwe, 
"  being  in  length  about  twenty  miles;  the  tin- works 
"  being  there  fixed  upon  a  great  nver  running  clear 


i  AaXitA  February  2n(l,  I66I  *,  1  therefore 
conclude  that  Mr.  Yanantun's  journey  to  Saxony  must  have 
been  about  the  year  1665. 


U 
U 


fi74  ON  THS    MANUFACTURE 

<<  along  the  valley,  and  also  upon  some  little  rivulets 
^'  that  run  out  of  the  mountains  of  Bohemia  and 
Saxony;  and  coming  to  the ^ works,  we  wet^  veiy 
civilly  treated,  and, .  eontiwy  to  our  expectation^ 
^  we  had  much  libekty  tio  view,,  and  see  the  wiuks 
go--with  the  way  and  mawer  of  their  worldiig 
and  extendi^  the  plates^  as  also 'ihe  .'perfect  view 
<*0f  such  materiak  as  tb^  used  in  clearing,  the 
^  plates,  to  make  them. fit  to  take*tin,.withihe  wqr 
^  they  use  in  tinning  them  .over,  when  deansd  firmn 
their  rust  and  bladmess*     And' having  (aawe 
judged)   sufficiently  ^  ohtained  the  whole  art  of 
nraking  and  tinning  the  plates,  we  then  came  far 
England,  where  the  several  persons  concerned  in 
^^  theafiair  thought  fit  to  make  some  trial  in  making 
^  some  small  quantities  of  plates  and  tinniag  themj 
'*  which  was  done*;  and  all  workmen  that  wrought 
upon  them  agreeing  that  the  plates  were  much 
**  better  than  those  whidi  were  made  in  GernGMuiy; 
upon  which,  preparation  was  making  to  set  this 
beneficial  thing  at  work  ;'-^but,  it  being  under^ 
**  stood  at  London,  a  fatbnt  was  trnmpt  up,  and 
the  patentee  was  countenanced  by  some  persons 
^  of  quality—and  what,  with  the  patent  being  in 
'^  our  way,  and  the  richest  of  our  partners  being 
'*  afraid  to  offend  great  men  in  power,  who  had 
their  eye  upon  us,  it  caused  the  thing  to  cool, 
and  the  making  thereof  was  neither  proceeded  in 
"  by  us,  nor  possibly  could  be  by  him  that  had  the 
^'  patent ;  because  neither  he  that  hath  the  patent. 


4€ 
£* 
€€ 


U 


OF   TIN    PLATE.  575 

*'  nor  those  that  have  countenanced  him,  can  make 
*'  one  plate  fit  for  use'"." 

This  enterprising  individual,  who  spent  the  great- 
er  part  of  his  life  in  promoting  schemes  for  the  good 
of  his  country,  and  who,  in  the  opinion  of  Bishop 
Watson,  ought  to  have  had  a  statue  erected  to  his 
memory,  proceeds  to  inform  us,  that  before  they 
were  stopped  by  the  patent  they  had  made  "  many 
"  thousand  plates  from  iron  raised  in  the  forest  of 
"  Dean,  and  tinned  them  over  with  Cornish  tin, 
"  and  the  plates  proved  far  better  than  the  German 
"  plates,  by  reason  of  the  toughness  and  flexible- 
"  ness  of  our  forest  iron.  One  Mr.  Dison,  says  he, 
"  a  tinman  in  Worcester,  one  Mr.  Lydiale  near 
"  Fleet-bridge,  and  one  Mr,  Harrison  near  the 
*'  Kingsbench,  have  wrought  many,  and  they  know 
"  their  goodness"." 

In  anotlier  place  this  interesUog  writer  informs 
us,  that  "when  he  was  in  Saxony  the  different  es- 
*'  tablishments  for  making  tin-plates  were  very  nu- 
'*  raerous,  and  that  most  of  them  belonged  to  the 
*'  duke"."  "The  trade,"  says  he,  "is  so  great, 
"  that,  by  computation,  no  less  than  SO.CKX)  men 
"  depend  upon  It ;  and  when  the  plates  are  finished, 
'*  they  are  sent  by  land  to  Lipsick,  from  thence  to  the 
"  Elbe  river,  and  so  down  to  Hamburg,  and  from 
"  thence  sent  by  sea  as  fur  as  trade  is  known  '■*." 
"  There  was,"  says  tie,  "  no  tin  any  where  in  Eu- 
"  rope,  except  in  Cornwall,  until  a  Corni&h  man 

'"  Engtand't  Im^Toemml,  Ac.  page  149 — 152,  Part  U. 
"  Pwfe  173.  "  Page  )ji.  "  Page  \7i. 


576  ON  THE   MANUFACTURE 

<^  found  tin  in  the  mountains  of  Saxony,  near  a  town 
**  called  j^we,  where  his  siaiue  is  yet  to  be  seen. 
**  The  tin  works  are  fixed  upon  a  great  river  running 
*^  down  the  valley ;  and  the  tin,  iron  and  woods, 
**  grow  in  and  upon  the  mountains  adjoining  to 
'*  both  sides  the  river ;  and  those  tin-works  have 
<*  proved  so  beneficial  to  the  place,  that  there  are 
^*  several  fine  cities  raised  by  the  riches  proceeding 
<<  therefrom  '*r  He  adds,  ''  The  trade  of  making 
tin*plates  was  about  sixty  years  since  fixt  in  Bo^ 
hernia,  and  had  there  long  continued ;  but  the 
'  woods  decaying,  and  there  being  at  that  time  a 
wise  duke  of  Saxony,  willing  and  ready  to  im- 
prove his  own  revenue,  and  his  subjects,  did  ac- 
cept of  directions  how  this  trade  might  be  brought 
away  and  fixt  in  the  duke  of  Saxony*s  territories  " 
**  — A  Romish  Priest,  converted  to  be  a  Lutheran, 
**  was  the  chief  instrument  in  the  whole  aflair,  until 
"  it  was  perfected — and  a  Cornish  miner,  a  Protest- 
ant, who  had  been  banished  out  of  England  for 
his  religion,  found  out  the  tin  in  Saxony — both 
**  which  persons  proved  instruments  of  great  wealth 
**  to  that  duke  and  country  '*.'' 

Tlie  following  particulars  which  I  have  collected 
respecting  Mr.  Yarranton,  will  justify  Bishop  Wat- 
son in  the  opinion  he  has  given  of  him. 

He  was  bound  as  an  apprentice,  early  in  life,  to 


€€ 
€€ 
€t 
€€ 
<« 
€€ 


»*  Yarranton,  part  ii.  page  176.  **  Ibid,  page  178. 

^^  Saxony  Is  separated  from  Bohemia  by  only  a  chain  of 
mountains  called  the  Erzegeberg ;  which  in  Gennan  sigrnifies 
hills  that  contain  mines. 


OF   TIN    PLATS.  677 

a  linen  draper,  but  after  some  years  he  left  that  si* 
tuation  in  disgust.  In  the  year  lfi5'2  lie  took  some 
iron  works,  which  he  carried  on  for  several  years ; 
and  during  this  period  he  made  regular  surveys  of 
the  three  great  rivers  in  England,  and  hy  means  of 
associations  whicli  were  formed  by  himself,  he  ren- 
dered three  other  rivers  navigable  :  he  studied  agri- 
culture with  such  effect,  that  many  of  the  arable  es- 
tates in  the  midland  counties  were  rendered  doubly 
productive  by  the  new  methods  of  husbandry  which 
he  either  brought  from  abroad,  or  discovered  ; — he 
laid  a  plan  for  the  junction  of  the  Thames  and  Se- 
vern at  that  spot  where  of  late  years  this  very  scheme 
has  been  effected  ;— he  proposed  the  cutting  of  se- 
veral navigable  canals,  half  a  century  before  any  such 
project  had  been  executed  in  this  country.  He  made 
the  necessary  surveys  and  planned  docks  for  the  cities 
of  London  and  Dublin  ; — besides  his  journey  to 
Saxony  already  mentioned,  he  went  to  Holland, 
under  the  patronage  of  the  ancestors  of  some  of  our 
present  nobility,  to  examine  the  inland  navigations 
of  the  Dutch,  and  to  investigate  the  nature  of  their 
linen  manufactures ; — and  on  his  return  promul- 
gated the  plan  for  a  new  manufacture  of  linens, 
which  he  calculated  would  employ  all  the  poor  of 
England.  He  published  schemes  for  the  improve- 
ment of  our  national  fisheries  ;  he  made  several  tours 
through  Ireland,  for  the  express  purpose  of  planting 
new  manufactures  and  devising  the  increase  of  the 
staple  trades  of  that  country:  he  made  a  regular 
survey  and  estimate  of  the  expense  of  rendering  the 
VOL.    II.  2  p 


578  ON   THE   MANUFACTURE 

river  Slade  in  Ireland  navigable,  for  the  purpose  (rf 
bringing  timber  down  to  the  coast  for  His  Majesty  8 
navy;  and  rendered  many  other  signal  services  to 
his  country. 

Notwithstanding  Mr.  Yarranton  had  so  com- 
pletely introduced  the  knowledge  of  making  tin- 
plate  into  this  country,  I  do  not  find  that  any  aia- 
nufacture  of  that  article  was  established  in  these 
kingdoms  until  some  time  between  the  years  1720 
and  1730,  which  must  have  been  long  after  Mn 
Yarranton's  death.  The  first  establishment  of  this 
kind  was,  I  believe,  fixed  in  Monmouthshire,  where 
it  continued  to  flourish  many  years  ". 

About  the  time  that  this  manufactory  was  esta- 
blished, the  amiable  and  intelligent  M.  Reaumur, 
to  whom  the  French  are  indebted  for  a  new  mode 
of  graduating  the  thermometer,  and  for  many  dis- 
coveries and  improvements  in  the  arts  *% — under- 
took to  discover  the  method  of  making  tin-plates 
for  the  French  people.  This  eminent  man,  whose 
mind  was  cast  in  a  mould  very  similar  to  that  of 
Mr  Yarranton,  but  who  possessed  more  science, 
never  relinquished  any  thing  which  he  undertook; 
and  accordingly,  notwithstanding  the  innumerable 
difficulties  which  he  had  to  encounter,  at  length  suc- 


'^  Upon  further  inquiry,  I  find  that  this  was  at  the  tO¥m  of 
Ponty  Pool  3  and  it  is  remarkable,  that  after  the  lapse  of  nearly 
1 00  years  the  manufacture  has  recently  been  re-established  at 
the  same  town  on  a  very  extensive  scale. 

*^  It  was  Mons.  Reaumur  who  was  the  means  of  introducing 
into  France,  the  methods  of  making  Porcelain.  See  Essay  <m 
Porcelain,  page  94. 


OF   TIN    PLATE.  5/9 

ceeded  in  acquiring  such  a  knowledge  of  the  prin- 
ciples of  the  manufacture,  as  enabled  him  to  instruct 
several  people  in  the  vicinity  of  Paris,  in  an  art 
which,  until  then,  had  never  been  practised  in  that 
country. 

Soon  after  the  time  of  which  I  am  speaking,  se- 
veral similar  manufactories  were  erected  in  Great 
Britain ;  and  now  the  establishments  of  this  nature 
are  so  numerous  and  extensive  in  many  parts  of  these 
kingdoms,  that  the  manufacture  of  tin-plate  is  be*- 
come  of  great  national  importance,  and  more  than 
one  hundred  thousand  boxes  of  these  plates  are  an- 
nually exported. 


2  p2 


APPENDIX. 


ADDITIONAL    NOTES 


THE    SECOND    VOLUME. 


NOTKS  TO  ESSAY  IX. 


1.  Nilrum.—Pagc  6.  line  10. 

N ITRUM  or  nalrvn  wiis  willioul  doubt  known  to  the  ancients, 
ihoug'h  we  have  no  evidence  that  nitre  was.  In  the  rroverbw  of 
Solomon,  chap.  xxv.  ver.  20,  it  'a  said,  thai  "  As  he  ihat  taketh 
away  a  garmenl  in  caU  weather,  and  as  vinegar  upon  iiitr&,  so 
is  he  thnt  sings  BongH  to  a  heavy  hcnri ;"  here  the  word  ought 
certainly  to  be  nitrum  or  natron,  for  on  this  vinegar  would  oc- 
casion a  violent  effervescence,  though  not  upon  salt-petre  or 
nitre.  "A  memoir  on  an  extraordinary  collection  ofsult-petre, 
which  was  made  in  France  during  the  years  1794  and  1795, 
also  on  B  new  method  of  refining  this  salt,  by  C.  A.  Prieur," 
will  be  found  in  the  Antuiiei  de  Chimie,  tome  \x.  page  298. 

An  account  of  a  remarkable  cave  in  Kentucky  in  the  United 
States  of  America,  cdled  Mammoth  Cave,  which  contains  an 
extraordinary  quantity  of  salt-petre,  may  be  seen  in  the  Arcturo- 
liigia  Americana,  pages  355— 3C I, 

2.  Very  curroiive. — Page  7,  line  IC. 
Thifi  alkali  in  its  pure  state  is  so  corrosive  that  it  is  employed 
by  the  surgeons  for  what  is  called  their  Polentiiil  cautery.  Boer- 
haave  relates,  that  an  unfortunate  man  who  fell  iniu  u  boiling 
copper  of  a  lixivium  of  caustic  potash,  bad  all  the  soft  parts  of 
his  body  dissolved,  and  nothing  remained  but  his  bones. — See 
Dnilow  s  edition  of  BoLThauve's  EUmmtt  of  Cht-mittry,  quarto, 
vol.  ii.  page  -13.     Dreadful  accidents  have  somctimca  happened 


584  ADDITIONAL   NOTES. 

from  persons  having  swallowed  caustic  alkali.  The  late  Dr. 
Johnstone,  an  eminent  physician  of  Worcester,  when  writing 
on  this  subject  remarks,  that  "  it  will  perhaps  require  8  or  10 
grains  of  caustic  alkali  to  destroy  texture,  for  a  small  quantity 
would  be  neutralized  by  the  carbonic  acid  it  meets  with  in  the 
passage,  or  by  the  contents  of  the  stomach  itself.** — Johnstone 
on  mineral  poisons,  page  151).  See  also  an  article  under  the 
title  of"  Causticity"  in  the  Additwns  to  Macquer's  Dicikmarff 
of  Chemistry,  octavo,  vol.  ili. 

3.  Barilla  imported, — Page  9,  line  28. 

A  gentleman  who  is  just  returned  from  Spain,  where  lie  has 
resided  several  months,  has  obtained  the  following  informatiOD. 
"  The  best  barilla  usually  exported  to  Ireland  grows,**  he  says, 
"  in  the  neighbourhood  of  Alicant.  It  is  gathered  from  the 
months  of  August  to  October.  A  considerable  quantity  of  the 
finest  quality  is  sent  to  Paris,  of  which  their  superior  crystal 
glass  is  made.  It  is  usually  purchased  in  November ;  and  a 
curious  circumstance  is  connected  with  the  bargain,  viz.  that 
though  the  price  be  Jixed  when  the  barilla  is  received  by  the 
merchant,  the  latter  obliges  himself  to  make  good  any  advanoe 
which  may  take  place  until  Christmas-day  -,  so  that  of  oouise 
cargoes  arrive  at  their  destination,  and  are  disposed  of,  befbie 
their  real  cost  is  known.  When  the  crop  promises  to  be  scaa^, 
it  is  necessary  to  bribe  the  farmers  by  anticipated  payments. 
Abundance  of  barilla  is  made  at  Carthagena,  and  throughout 
the  province  of  Valentia.*' 

4.  Rendered  caustic, — Page  12,  line  7. 

As  it  is  important  to  those  who  use  large  quantities  of  the 
fixed  alkalies  to  know  when  a  proper  quantity  of  lime  has  been 
used  to  render  them  caustic — the  following  directions  will  pro- 
bably be  acceptable  to  many  individuals.  When  the  solution 
of  caustic  alkali  is  prepared,  take  a  little  of  the  clear  liquor  in  a 
wine-glass,  and  breathe  into  it  through  a  small  glass  tube,  or 
otherwise  add  a  few  drops  of  a  clear  solution  of  subcarbonste 
of  potash ;  for  if  there  be  a  redundance  of  lime,  the  dissolved 
earth  will  absorb  carbonic  acid  from  the  carbonate  of  potash  or 
from  the  human  breath,  and  this  will  render  the  liquor  turbid. 
If  this  treatment  should  not  occasion  the  liquor  to  become  tur- 
bid, it  should  then  be  treated  with  a  little  lime-water ;  and  if 
this  occasions  a  turbidness,  it  shows  that  the  liquor  contains 
carbonated  alkali,  and  consequently  has  not  had  a  suflScient 
(quantity  of  lime  ;  whereas,  if  the  lime  be  in  due  proportion,  the 
lixivium  will  suffer  no  chanee  from  the  addition  of  the  abova 
tests,  nor  will  it  effervesce  with  acids. 


ADDITIONAL   NOTES. 


683 


5.  Caustic  potaih. — Page  \2,  line  17. 
s  for  prepnring  caustic  potash  in  a  dry  «tate,  will 
be  found  in  Boerhaave's  Etemenls  of  Chemistrif,  quarto,  vol.  U. 
DB^  42.  Whenever  il  is  necessary  to  open  a  bottle  of  pure  al- 
kali, it  should  be  done  in  a  dry  air,  or  near  a  lire,  and  then  the 
stopper  immediately  returned  and  carefully  secured  by  wax  ui 
at  first.  Directions  for  the  preparation  of  pure  potash  and  sods 
by  means  of  alcohol  nre  given  by  Dr.  Henry  in  his  EUmenlt 
of  Experimental  Chetaufrif,  vol.  i.  page  255.  See  also  Davy, 
in  the  Philosophical  Transactions  for  1808,  page  355  :  and  the 
Euay  on  Water,  vol.  ii.  page  366.  An  account  of  the  method 
which  Lowitz  has  adopted  for  obtaining  tlie  alkalies  of  the 
grentest  purity,  in  n  crystallized  state,  will  be  found  in  Nichol- 
son's Quarto  Journal,  vol.  i.  page  164. 

6.  Fern.— Page  17,  line  I. 

A  chemical  friend  who  ha.s  had  much  experience  in  the  pre- 
paration of  the  fixed  alkalies,  and  who  reque>^ted  that  I  would 
allow  him  the  perusal  of  my  Essay  on  that  subject,  has  sent  me 
the  following  remarks  on  what  I  have  said  respecting  the  agency 
of  Fern  in  milling  woollen  cloth  ;  and  which  he  attributes  not 
to  the  alkali  which  it  contains,  but  merely  to  its  mechanical 
operation  on  the  cloth.  As  1  should  not  deal  candidly  with  my 
readers  if  I  withheld  these  remarks,  I  here  give  them  exactly  aa 
I  have  received  them.  "  I  entertain  strong  doubts,"  says  he, 
"  of  the  juices  of  fern  or  any  other  vegetable  plant  containing 
an  alkali  in  a  free  state,  having  always  considered  iitcineratim 
to  be  an  essential  process  for  the  development  of  that  suit.  I 
have  made  several  experiments  on  the  kelp  weed  and  other  of 
the  fuci,  but  could  never  perceive  the  least  trace  of  free  alkali 
in  their  expressed  juice,  although  the  oshex  produced  by  burn- 
ing them  always  gave  indications  of  its  presence.  These  vege- 
tables probably  contain  neutral  salts,  (the  sulphates  of  potash 
and  soda  for  example,)  which  undergo  a  decomposition  in  the 
fire,  and  in  which  their  own  carbon  probably  acts  as  a  powerful 
agent.- 

7.  AV(p.~-Page  38,  line  5. 

Jameson  stales,  that  barUla  contains  from  8^  to  23  per  cent, 
of  pure  alkali  divested  of  water  and  carbonic  acid,  and  that 
kelp  contains  from  2  to  5  per  cent.  From  an  analysis  which  1 
myself  mode  of  three  parcels  of  barilla  in  the  year  1801,  one  of 
which  wBsfromAlicanl,  another  from  Carthagena,  and  the  third 
from  Teneriffe,  all  of  which  were  at  that  lime  esteemed  to  be  the 
bnt  samples  in  the  London  market  i  i  found  that  112  lbs,  of 


586  ADDITIONAL   NOTES. 

the  first  contained  19  lbs.  2  oz.  of  pure  dry  caustic  alkali  ^  ]  12 
lbs.  of  the  second  contained  22|-  lbs.  of  alkali ;  and  the  Tene- 
rifk  22^  lbs.  which  was  esteemed  much  better  than  is  usually 
•brought  from  that  island. 

Four  parcels  of  barilla  which  I  examined  with  great  care  on 
the  4th  of  June  18 10^  were  found  to  be  composed  as  under. 
The  first  parcel  consisted  of  19  parts  pure  soda^  22  of  neutral 
salts  and  carbonic  add^  and  59  of  insoluble  matter.  The  se- 
cond parcel  gave  18  per  cent,  of  pure  alkali^  21  of  neutral  salts, 
&c.,  and  61  of  insoluble  matter.  Another  contained  10^  uore 
alkali/ 24  neutral  salts,  kc,,  65  of  insoluble  matter,  and  ^  loss. 
The  fourth  parcel  consisted  of  1 1  parts  of  pure  alkali^  20  neutnl 
salts,  &c.,  and  69  of  insoluble  matter. 

Two  other  samples  were  analysed  on  the  1st  of  February 
1813  :  one  of  which  contained  3O4  per  cent,  of  pure  dry  sods, 
lOf  neutral  salts,  9  carbonic  acid  and  50  insoluble  matter.  This 
was  the  best  sample  of  barilla  that  I  ever  recollect  to  have  come 
under  my  examination.  Kelp  is  of  very  various  quality ;  I  have 
seen  some  which  contained  8  per  cent,  and  others  whidi  would 
not  yield  one  per  cent,  of  pure  soda.  The  particulars  of  the 
analysis  of  several  parcels  of  kelp  and  barilla  which  I  made  kx 
the  Highland  Society  of  Scotland  in  the  year  1816  will  be  found 
in  the  5  th  vol.  of  the  Transactions  of  that  Society,  page  65,  &c 

8.  Kelp  ovens. — Page  39,  line  13. 

The  ovens  in  which  kelp  is  made  are  generally  of  the  rudest 
kind,  being  nothing  more  than  excavations  within  the  ground, 
lined  with  rough  unhewn  stones.  I  would  earnestly  recommend 
it  to  the  proprietors  of  our  kelp  shores  to  erect  one  or  more  re- 
verberatory  furnaces  similar  to  those  described  in  the  plates 
which  accompany  the  Essay  on  the  fixed  Alkalies  j  for  by  means 
of  such  furnaces  a  greater  heat  would  be  produced,  and  the  mat- 
ter might  be  stirred  with  greater  convenience ;  and  hence  there 
would  be  a  more  effectual  decomposition  of  the  muriate  of  soda 
by  means  of  the  vegetable  alkali  which  these  plants  always  fur- 
nish in  abundance.  By  such  management  I  apprehend  much 
of  the  Irish  and  Scotch  kelp  might  be  rendered  of  double  its 
present  value.  See  the  plates  No.  16  and  17,  and  the  descrip- 
tions given  of  them  at  the  beginning  of  this  volume. 

9.  Soda  for  glass, — Page  47,  line  16. 

Since  this  paragraph  was  written,  1  have  investigated  the 
nature  of  the  comparative  effects  of  soda  and  potash  in  making 
glass  'j  and  1  am  now  convinced  that  a  harder  glass  may  be  made 


ADDITIONAL   NOTES.  00/ 

with  soda  Uian  it  u^pussiblc  to  produce  frumpotush  only,  and  that 
soda  therefore  ought  always  to  be  made  choice  of  for  making 
plate  glass.     See  the  Eway  on  Glass,  vol.  il.  page  245 — 248. 

10.  Oil  soap. —  ["age  47,  lire  20. 

It  Is  well  known  that  olive  oil  produces  better  soap  than  an^ 

other  substunce.     I  am  therefore  anxious  to  suggest  whether  it 

might  not  be  a  desimble  thingfor  Governrneni  to  encourage  the 

g'owih  of  olive-trees  in  some  of  the  British  colonies,  or  in  some 
vourable  district  jn  the  British  settlements  in  the  East  Indies, 
The  oil  would  in  time  form  an  important  branch  of  commerce, 
especially  if  enough  were  produced  to  supply  all  our  soap-ma- 
nufactories :  and  this  would  render  the  countrymore  independent 
of  Russia  ;  which  is  a  very  important  object.  A  comi>etent 
opinion  of  the  volue  of  this  oil  for  the  manufacture  of  soap, 
when  compared  with  others,  both  vegetable  and  animal,  may 
be  obtained  by  perusing  n  memoir  in  the  Annalei  de  Chimit, 
tome  xix.  pages  289 — 311.  The  idea  of  recommending  the 
cultivation  of  the  olive  occurred  to  me  on  reading  the  following 
passage  :  *'  The  olive-tree,"  says  Savaiy,  "  has  almost  disap- 
peared from  Attica.  The  Albanians  and  Turks,  who  have  al- 
ternately ravaged  Greece,  seem  to  have  been  intent  on  destroy- 
ing it.  Within  twenty  years  they  cut  down  two  hundred  thou* 
sand  feet  of  these  trees.  The  island  of  Crete  has  not  suflered 
the  same  fate.  The  olive-trees,  which  delight  in  a  sandy  soil,  -l 
a  mild  temperature,  and  the  vicinity  of  the  sea,  grow  in  abun-  ' 
dance  on  the  hills  and  in  (he  plains.  Their  produce  conslitutoi 
the  chief  wealth  of  the  inhabitants,  and  their  principal  branch 
of  commerce.  Exclusive  of  the  prodigious  consumption  of  oil 
by  the  iuhabilants,  besides  what  the  iSirks  of  Cauea  moke  use 
of  in  the  manufacture  of  soap,  which  they  export  tliroughout  the 
Levant,  the  Turks  annually  load  four -and -twenty  ships  with  oil, 
containing  on  an  average  one  hundred  and  fifty  tons  each."—  ' 
Savary's  Letter*  on  dreece,  octovo,  1 7S8,  page  3B I . 

1 1.  .Vi>  Humphry  Daiy. — Page  59,  line  8. 
After  this  paragraph  was  printed,  1  discovered  a  trifling  ei 
in  the  date  which  I  have  given  to  the  first  decomposition  of  the  ! 
alkalies  by  Sir  H,  Davy;  for  I  now  perceive  thai  the  paper  I 
which  1  mention  as  having  been  read  before  the  Royal  Society,  i 
contained  a  detail  of  his  sub$ei]itent  experiments,  the  discovery 
itself  having  been  announced  in  the  preceding  year  (It^Oti),  and  J 
the  particulars  of  it  described  in  the  volume  of  The  Fhilmophicat  i 
Trantartioni  for  that  vear. 


598  ADDITIONAL   NOTBa. 


12.  Depositories  of  salt, — Page  68,  line  1. 

Notwithstanding  these  immense  masses  of  salt  found  in  m- 
rious  parts  of  the  world,  there  are  places  where  salt  has  never 
yet  been  discovered :  this  is  the  case  in  many  parts  of  Africa. 
Mungo  Park  relates  that  "  the  greatest  of  all  luxuries  in  the 
interior  of  Africa  is  salt.  It  would,"  says  he,  '*  appear  strange 
to  an  European  to  see  a  child  suck  a  piece  of  rock  salt  as  if  ii 
were  sugar.  This,  however,  I  have  frequently  seen  ;  althongfa 
the  poocer  class  of  inhat^itants  are  so  very  rarely  indulged  with 
this  precious  article,  that  to  say  '  A  man  eats  salt  with  his  pro- 
visions,* is  the  same  as  saying '  He  is  a  rich  man.*  1  have  suf- 
fered great  inconvenience  myself  from  the  scarcity  of  this  artide. 
The  long  use  of  vegetable  food  creates  so  painful  a  longing  fiMr 
salt,  that  no  words  can  sufficiently  describe  it."  Park  s  Tntveis 
into  the  Interior  of  Africa,  quarto,  1799.  Some  persons  have 
imagined  that  it  is  an  useless  an4  pernicious  practice  to  take 
salt  with  our  food ;  but  the  abov^  testimony  seems  to  decide 
that  question.  On  looking  over  a  work  printed  by  Kearsley,  in 
small  octavo,  1768,  I  find  the  following  experiment  is  related: 
"  I  put/*  says  the  author,  "  two  ounces  of  milk,  warm  as  it 
comes  i^om  the  cow,  into  a  tea-cup  with  a  little  common  ndt 
I  put  the  same  quantity  and  of  equal  warmth  into  another  tea- 
cup, without  salt.  Then  dropping  a  very  little  distill^  vinesar 
into  each,  a  hard  curd  presently  appeared  in  that  milk  which 
had  no  salt  in  it,  while  the  other  with  the  salt  was  scarcely  al- 
tered.'" 


tt 


13.  Salt  mines  of  Poland.'-?Bige  68,  line  3. 

"  We  read  of  a  salt  mine  in  Poland,  one  mile  from  Cracow, 
which  is  200  fathoms  below  the  surface,  where  there  were  1000 
men  constantly  employed.  In  order  to  descend  into  this  stu- 
pendous work,  it  was  customary  for  the  person  descending  to 
fasten  himself  by  a  cord  to  the  main  rope,  and  then  to  take  an- 
other man  on  his  lap.  The  large  rope  being  then  lowered  a 
little,  a  third  person  made  a  seat  for  himself  with  a  rope  fast- 
ened to  the  main  rope,  taking  another  on  his  lap  ;  and  being 
also  let  down  a  little  way,  he  gave  an  opportunity  for  another 
pair  to  fasten  themselves  in  the  same  way  :  in  which  manner 
thirty,  forty,  or  more  people  were  let  down  at  once ;  of  whom 
the  first  having  touched  the  ground  at  the  bottom,  steps  out  and 
goes  aside,  the  rest  following  him  in  regular  order  and  doing 
the  like.  Thus  they  descended  to  the  depth  of  100  fathoms  ; 
and  after  passing  through  several  passages  they  came  to  certain 
ladders  by  which  they  descended  1 00  fathoms  deeper."     Philo- 


ADDITIONAL    NOTK3.  o83 

mpkual  Trdttiarlwim  for  1070,  puge  10'J9.  In  llie  same  vo- 
lume there  is  an  account  of  the  discovery  of  amine  of  very  hard 
rock  snit  at  Rotherton  in  Cheshire,  upwards  of  30  yards  below 
tlie  surface  of  the  earth. 

The  salt  mine  above  mentioned  is  at  the  town  of  Wielitaka^ 
a  Getmun  mile  from  Cracow  :  it  is  the  largest  in  Europe,  imd  | 
has  been  constuntly  worked  for  more  tlun  600  years :  it  is  eleven 
hundred  feet  in  uidth,  and  6,700  feet  in  length.  The  aubter' 
ninean  passages  or  galleries  are  very  spacious,  and  in  many  of 
them  altars  or  chapels  are  hewn  out  of  the  salt-rock,  in  these  i 
chapels,  crucifixes  or  the  images  of  saints  arc  set  up ;  and  s 
light  is  kept  continually  burning  before  them.  The  places  where 
the  salt  is  hewn  out  of  the  mine,  are  called  chambers  ;  and  some 
of  these  are  so  spacious  that  a  large  church  might  be  inclosed 
in  one  of  them.  When  candles  are  brought  into  these  placeSi 
the  numerous  rays  of  light  reflected  by  the  crystab  of  salt  emit 
a  surprising  lustre.  About  600,000  quintals  of  salt  are  annualtf 
dug  out  of  the^e  mines,  lliat  part  of  the  mine  wluch  has  been 
most  excavated,  and  which  appears  like  a  vast  plain,  is  inter- 
spersed nith  clusters  of  huts  belonging  to  the  miners  and  theu  , 
families,  many  hundreds  of  whom  are  bom  and  (inbh  their  lives 
in  this  subterranean  inclonure. 

"There  are  salt  mountains,"  sap  Jonston,  "  in  India,  par- 
ticularly al  Oiomeuus,  where  it  is  cut  out  of  quarries  like  slonf ; 
and  the  custom  arising  from  it  is  mure  to  their  kings  than  what 
they  receive  from  gold  and  pearls."  Jonston 's  Hitioty  of  Nature, 
P.M. 

14.  Decomposlliott  o/in».— Page  69,  line  12. 

Several  patents  having  been  obtained  at  different  times  by 
various  individuals,  for  their  peculiar  methods  of  procuring  sode 
from  sea  salt,  and  having  myself  many  years  ago  devoted  much 
time  and  expense  to  the  investigation  of  this  subject,  I  am  glad    < 
that  1  have  it  in  my  power  to  furnish  my  readers  with  a  li>t  of  ] 
those  patents,  which  at  the  time  were  registered  among  other  i 
chemical  manuscripts,  as  being  those  which  appeared  to  m    *" 
possess  the  most  merit. 

James  King,  dated  March  4th,  -  -  1780 
Alexander  Kordvce,  August  1st,  -  -  1781 
Earl  of  Dundon'ald,  February  28th,-  1/95 
Hobert  Hoaksley,  July  20th,  -  ...  1796 
George  Hodson,  February  28th,  .  -  1797 
Mr.  llodsun  obtained  a  patent  for  the  same  object,  whidl   I 

bore  dale  August  30,  179!^;  but  the  mode  therein  described  J 

will  not  efTect.  the  desired  purpose. 


59Q  ADDITIONAL   NOTES. 

\Vh))e  on  the  subject  of  Sea-salt,  I  embrace  the  opportunity 
of  mentioning  a  nt-w  purpose  to  which  salt  has  been  applied, 
and  which  certainly  deserves  to  be  registered  for  the  beneGt  of 
the  public.  Some  merchants  of  Liverpool,  who  in  the  year  18  i^ 
had  prepared  several  hundred  carboys  of  oil  of  vitriol  to  be  eX' 
ported  to  America,  hod  them  stowed  on  board  two  sliips,  and 
filled  up  all  the  vacant  spaces  between  the  baskela  with  common 
gatt  to  prevent  the  bottles  from  being  broken  by  the  motion  of 
the  vessels.  Proposals  for  the  insurance  of  these  precious  car- 
goes were  sent  to  Lloyd's,  and  the  eircumstance  of  the  stowage 
in  salt  was  mentioned  to  induce  the  underwriters  to  insure  at 
a  lower  premium.  Some  gentleman,  however,  who  knew  the 
effect  which  would  be  produced  by  the  affusion  of  oil  of  vitriol 
upon  salt,  saw  the  proposals  at  Lloyd's,  and  stated  that  if  a  sin- 
gle bottle  should  by  any  accident  become  broken  on  the  passage, 
every  individual  on  board  would  inevitably  be  suRbcated.  It 
was,  however,  eoo  late  to  take  any  precautionary  measures,  !6t 
the  vessels  had  then  both  actually  sailed.  "Die  names  of  the 
ships  which  were  then  crossing  the  Atlantic  in  such  a  perilous 
situation  were  the  Leieis  and  the  Margaret,  I  believe  both  of 
Liverpool.  Should  either  of  these  vessels  have  sprung  a  leak,  no 
as  to  dissolve  much  of  the  salt,  the  stowage  of  the  carboys  woidd 
have  been  loosened,  and  some  of  the  bottles  would  unavoidably 
have  been  broken,  by  the  rocking  of  the  ship. — Here  we  Iwv'c 
another  instance  how  necessary  it  is  that  all  cks.ses  of  society 
should  become  acquainted  with  the  elements  of  chemical  science. 

1.1.  Rnek  ../i^— Page  09,  line  3. 
It  is  very  important  to  the  curers  of  provisions  lo  employ  the 
purest  salt  which  lliey  can  obtain.  This  is  deemed  so  neces- 
sary,  that  some  of  the  Irish  provision -curers  have  been  in  the 
habit  of  using  foreign  salt,  preferring  it  chiefly  on  account  of 
itt  size  and  hardness  of  grain,  and  imagining  that  it  must  on 
these  accounts  be  belter  than  the  English  salt  for  their  purpose. 
It  has,  however,  been  proved  that  the  purest  and  best  salt  now 
known  is  that  which  is  made  from  the  rock  salt  of  Cheshire.  It 
has  been  usual  to  dissolve  the  mineral  salt  in  sea  water,  and 
then  re-crj'stallize  it;  but  as  sea  water  besides  muriate  of  soda 
contwns  ako  much  muriate  and  sulphate  of  magnesia,  both 
which  are  injurious  in  the  process  of  curing  either  fleah  or  fish, 
Messis.  Londons  of  Norlhwich  have  obtained  a  patent  for  re- 
fining rock  salt  merely  by  fusing  it  in  a  reverberatory  furnace. 
Their  salt  is  therefore  without  the  impurities  of  sea  water,  and 
also  without  either  the  water  of  cr)'staUization  or  water  of  ad- 
hcaion  :  hence  it  Ls  superior  in  iti  purity,  solidity,  and  magai- 


ADDITIONAL   NOTES. 

tude  of  grun,  to  any  imported  foreign  salt  whatever.  The 
samples  which  I  have  exitmined  of  this  salt  appear  to  be  very 
clear,  and  it  has  a  property  which  1  never  observed  in  any  other 
salt — tliat  it  does  not  decrepitate  in  the  fire.  The  bay-talt  im- 
ported into  this  country,  and  hitherto  bo  much  approved  for 
many  purposes,  is  all  made  by  the  evaporation  of  sea-water, 
and  consequently  must  be  extremely  impure.  The  price  of  com- 
mon salt  in  Cheshire,  without  duty,  lb  il.  i>erton  ;  the  price  of 
Messrs.  Londons'  redned  salt  is  21.  per  ton. 

General  Slalemenl  of  some  of  the  Resalti  of  Dr.  Henry'i  valiia' 
bte  Experimenlt  oil  carious  Kinds  of  Common  Sail. 


1000Putab}wei2htorew:hkiiidof]li>»).  ^lUy  ^^-  ^^* 


St,  Ubes  BaySall 

Oleron  Salt 

Scotch  Suit  from  Sea  water . 
Common  LymingtonSalt. . . 
Cheshire  crushea  Hack 

—  forthe  Fisheries 

—  Common 

—  Stoved 


4^  35  i 
I?      "■■ 


See  Dr.  Henry's  "  Memoir  on  the  Analysis  of  several  Varieties 
of  British  and  Foreign  Salt,"  in  the  Philoiophical  Trataactioai 
for  ISIO,  pag«89. 


NOTES  TO  ESSAY  X. 

ON    EABTHBNW4HK    AMD    FOHCELAIN. 

Ifi.  Roman  trie**,— Page  74,  line  8. 
Bbick-hakino  was  esteemed  un  art  of  great  consequence  by 
the  ancient  Romans;  in  proof  of  which  the  following  evidence 
presents  itself  Abdala.  the  slave  who  wailed  on  the  person 
of  the  empress  Livia  the  wife  of  Augustus,  was  set  over  all  the 
■laves  Ihnt  made  bricks ;  and  in  the  year  1 738,  on  exploring  the 
remains  of  the  ancient  city  of  Heroiclea,  it  was  observed  that  one 
of  the  bricks  bore  the  name  of  Abdala  and  also  that  of  his  mis- 
tress the  empress.  This  appears  the  more  extraordinary,  be- 
cause soon  after  the  time  of  Augustus  a  law  was  enacted,  or- 
daining lliat  no  architect  should  be  allowed  to  affix  hix  name 


592  ADDITIONAL   NOTES. 

upon  any  part  of  a  building  which  he  had  erected^  even  fhoof^ 
it  should  hiBivebeen  built  at  his  own  expense. — See  ADetcnptim 
of  the  fint  Discoveries  of  the  ancient  CUy  of  Neraelea,  trunslilfd 
byWickes  Skurray>  octavo,  1750,  page  58. — Pliny  aa]^  that 
'*  Euryalus  and  Hyperbius,  two  brothers,  at  Athens,  caused  the 
first  brick- and  tile-kiln  to  be  erected,  yea  and  houses  thereof  to 
be  made ;  whereas  before  that  time  men  dwelled  in  holes  and 
caves  within  ground.  Gellius  is  of  opinion  that  Doxina  the  son 
of  Coelus  devised  the  first  houses  that  were  made  of  earth  or 
day.** — Holland's  Pliny,  voL  i.book  vii.  page  188. 

17.  Water-pipes,— ?ag^  78,  line  19. 

Some  idea  of  the  state  of  the  potter*s  art  among  the  anciart 
Romans  may  be  conceived  from  the  following  passage  in  Pliny. 
'*  How  beneficial,**  says  he,  "  is  the  earth  unto  us  in  yiddin 
us  conduit-pipes  for  conveying  water,  tiles  flat  yet  hooked  and 
made  with  crotchets  at  one  end  to  hang  upon  the  sides  of  the 
roof,  chamfered  to  lye  in  gutters  to  shoot  off  water,  curbed  fat 
crests  to  claspe  the  ridg^  on  both  sides,  to  say  nothing  of  the 
vessels  that  be  turned  with  the  wheel  and  wrought  round  ;  yet 
and  great  tuns  and  pipes  of  earth  devised  to  contain  wine  and 
water  also !  In  re^rd  of  which  Numa  ordained  at  Rome  a 
seventh  confraternity  of  potters.** — Pliny*s  Natural  HiMtaqf, 
book  XXXV.  chap.  12,  page  55 1. 

18.  Roman  earthenware, — Page  79,  line  16. 

A  large  vessel  of  Roman  earthenware  was  found  during  the 
winter  of  1813  at  Ambleside  in  the  countv  of  Westmorelaod. 
where  it  Ls  supposed  an  old  Roman  city  originally  stood.  But 
the  most  interesting  detail  that  1  have  met  with  of  their  earthen 
vessels  is  in  the  account  of  the  discovery  of  the  ancient  dty  of 
Heraclea,  as  described  by  Marquis  Don  Marcello  di  Vinuti,  in 
a  work  already  quoted.  *'  Through  a  door  of  white  marble,** 
says  the  marquis,  ''  we  came  into  a  room  1 4  yards  long  and 
eight  broad,  which  led  into  another  room  of  the  same  length, 
but  almost  square.  Round  the  inside  of  both  these  rooms  there 
ran  along  close  to  the  wall,  about  half  a  yard  high,  a  kind  of 
bench  covered  with  a  marble  pavement,  which  seemed  at  first 
sight  to  have  been  used  for  a  seat ;  but  on  coming  to  examine 
it  nearer,  I  perceived  on  the  top  some  round  stones  or  8top|des 
of  marble  ;  which,  being  removed,  I  found  were  the  covers  of 
some  great  earthen  jars,  set  in  with  mortar,  the  necks  of  whidi 
were  inclosed  just  within  the  bench.  These  vessels  were  of  a 
roundish  form,  and  would  hold  ten  barrels  Tuscan  measure  each. 


ADUITIONAI.   KOTES. 

On  aiie  of  thtue  ve&sels  waa  this  inBcription  :  Orvs.  Doliahe. 
ViKiaiuu.  The  names  which  were  on  the  handles  and  necks 
of  these  vessels  were  the  namen  of  the  makers.  Thoite  wrote 
with  ink  were  the  names  of  the  owners  of  the  liquor  eantained 
within  ;  and  Ly  reason  of  the  multiplicity  of  names,  it  i 
gined  to  have  been  a  cellar  for  the  use  of  the  Holdiere  whi 
atalioneit  there  to  guard  the  walls  -,  and  that  whosesoever  name 
was  wrote  on  the  vessel,  to  him  belonged  the  wine  contitincil 
therein,  whether  he  bouglit  it,  or  it  was  his  allowance."  Skurray's 
translation  of  the  Dacription  of  the  Disroveriea  at  Hprmiea,  page 
1 10.  We  have  other  evidence  that  the  Romans  knew  how  to 
make  very  large  veasels  in  earthenware.  Pliny  nays  that 
"  Vitellius,  while  he  was  emperor,  caused  a  charger  to  lie  made 
and  finished  tliat  cost  a  miUion  of  sesterces,  fur  the  making 
whereof  there  was  a  furnace  built  on  purpose  in  the  field," — 
Pliny'M  Natural  Hitlonj,  Holland's  tranxlation,  folio,  vol.  ii.  book 
XXXV.  chap.  12,  page  ^51.  I  Huspect,  however,  that  Pliny 
must  have  been  misinformed  as  to  the  price  of  this  vessel,  for  a 
million  of  Roman  seuterces  are  equal  to  more  than  eight  thou' 
sand  pounds  of  our  money. 

It  is  generally  believed  that  the  ancient  Egyptians  had  also 
made  great  progress  in  the  knowledge  of  the  manufacture  of 
Earthenwitre.  Monx.  Belionisat's,"  The  art  of  varnishing  and 
baking  the  varni.sh  on  clny.  were  in  such  perfection  that  I  doubt 
if  it  could  be  imitated  at  present,"  and  this  remark  was  the  re- 
sult of  h»  own  observations.  Belzoni's  Researchet  in  Egypt, 
quarto,  page  J  73.  ' 

19.  LapU  latuU.—?age  tjl,  line  17- 

This  mineral,  says  Guyton,  "  may  be  urged  to  a  red  heat, 
and  even  lose  0,2  of  its  weight,  without  any  visible  alteration 
in  its  colour  ;  but  with  a  stronger  heat,  such  as  that  of  the  fur- 
nace of  an  enameller,  its  colour  changes  lo  gt^y-" — Guyton, 
jfTUutU*  de  Chimie,  tome  xixiv.  page  .^8.  Mr.  Delaval  supposes 
that  the  colour  produced  from  lapis  lazuli  was  applied  to  the 
painting  of  porcelain,  after  the  ware  had  undergone  the  heat  of 
the  furnace,  and  before  the  introduction  of  cobalt. — Delaval's 
Inquiry  ilo  the  Caute  of  the  Changes  of  Colours  in  opake  and 
cohured  Bodies,  4to,  London  1 777,  page  58. 

20.     Bernard  lie  Palitsy. — Page  90,  line  2 1 . 

Palissy  is  said  by  Fontcnelle  lo  have  gone  as  far  in  the  cha- 

'      la  genius  without  learning  could  carry 

n,  when  in  his  pleasant  moments,  used 

his  trade  as  a  potter,  that"  he  had  no 

■2  a 


Uissy 

racter  of'^  a  philosophi 

1^1.1  eminent  t 

y,  in  reference  ■ 


594  ADDITIONAL  ^  NOT£S. 

property  whatever,  except  heaven  and  earth,*' — Nouveau 
Hist  art.  Palisbt,  viii.  page  261.  No  one  can  have  read  the 
History  of  the  Life  of  Palissy  without  wishing  to  know  every  thing 
respecting  him.  For  an  account  of  the  books  published  Inr  him, 
and  of  the  nature  of  his  writings,  the  reader  may  consult  Platt*t 
Jewel  House  of  Art  and  Nature,  part  ii.  quarto,  London  1594. 

21.  A  collection  of  natural  history, — Page  92,  line  7. 

It  may  be  worth  noting,  that  a  very  satisfectory  view  of  the 
importance  of  the  study  of  natural  history  may  be  seen  in 
Mr  Stillingfleet's  Calendar  of  Flora,  The  work,  which  pro- 
mised to  be  of  the  utmost  importance  in  this  science,  was  planned 
by  Mons.  Martini  of  Benin.  It  was  entitled  An  Utuoend 
Dictionary  of  Natural  History,  He  lived,  however,  only  to 
finish  four  volumes ;  and  thou^  these  contain  nearly  700  pi^pes 
each,  he  did  not  get  through  Uie  second  letter  of  the  alphabtt 
The  author  died  in  1778,  and  I  am  not  informed  wheraer  the 
work  has  ever  been  continued. 

22.  Etruscan  vases, — Page  101,  Ime  19. 

A  beautiful  collection  of  Engravings  of  the  ancient  vases  io 
the  British  Museum  and  elsewhere,  has  been  published  by 
Mr.  Moses,  with  dissertations  on  the  vases  of  antiquity.  This  su- 
perb work  is  entitled  A  Collection  of  Vases,  AUars,  Paierm, 
Tripods,  Candelabra,  Sarcophagi,  8(c,from  various  Museuwu  and 
Collections,  engraved  on  170  Plates,  by  Henry  Mosch^  with  histo- 
rical Essays,  quarto,  1814.  The  most  superb  work  of  this  kind 
is  Sir  William  Hamilton's  Collection  of  Engravings  from  ancient 
Vases,  mostly  of  pure  Greek  Workmanship.  Three  imperial 
folio  volumes,  Naples  1791 — 1795. 

23.  C^.— Page  104,  line  5. 

Among  the  different  methods  of  sinking  pits  to  a  consideim- 
ble  depth  for  getting  clay,  there  is  one  practised  at  Forges  (de- 
partment of  the  Lower  Seine)  which  deserves  to  be  distinguished 
for  its  simplicity  and  economy. — It  escaped  me  while  writing 
the  Essay,  but  1  must  not  omit  to  refer  to  it  here.  For  the  de- 
tail, see  Loysel  sur  VArt  de  la  Verrerie,  page  43. 

24.  Decomposed  felspar. — Page  109,  line  3. 

Felspar  in  its  native  state  is  one  of  the  best  materials  for 
glazing  porcelain  ;  but  the  clay  which  results  from  it  by  its  de- 
composition is  totally  infusible.  This  circumstance  was  unac- 
countable until  VauqueUn  analysed  the  felspar,  and  found  that 
it  contained  potash.  To  this  therefore  must  its  fasibilit v  beattri- 


r 


ADDITIONAL    NOTES. 


bated.     The  fullowing  w  the  Hnalysis  whicli  lie  W.vi  given  of 
this  mineTa] ; 

Silica 62.BH 

Alumina    ....  17.02 


Oxide  of  Iron 
Potaali       .     . 
Lous     .     .     .     . 

I 

.     13 
.       3,15 

100.00 

it  is  proper  to  mention  that  some  persons  hnve  ol^ecteri  to 
the  use  of  felspar  when  containing  its  full  complement  ut  pot- 
ash, as  a  glaze  for  some  sorts  uf  porcelain  ;  because,  wherever 
a  glaze  contnins  too  much  of  either  of  the  fixed  alkalies,  it  is 
apt  to  contract  and  expand  unequally  or  in  a  different  ratio  from 
the  biidy  of  the  ware.  There  is  the  same  inconvenience  attend- 
ing tht'  use  of  powdered  glass  for  a  glaze,  which  will  sometimes 
either  fly  off  the  porceltiin,  or  become  cracked  in  various  places 
on  its  surface,  by  »udden  change  of  temperature.  For  an  ac- 
count of  the  composition  of  a  daze  employed  in  China,  see 
The  Pfiiloiophkal  Trantacliont,  No,  2" 


I,  261,  page  524. 
— I'age  124,  line  20. 
n  1  was  not  uwnre  thai  the  potter 


25.   Form  of  a 
When  the  text  was 
oven.t  which  are  now  built  are  not  conei,  but  are  constructed  ir 
the  form  of  o  cylinder,  mounted  by  a  dome, 

26.  An  unmholaiome  glaze. — Page  137,  line  l(j. 
In  addition  to  what  1  have  said  respecting  the  danger  of 
uain);  a  glaze  of  lead  on  any  of  the  articles  made  in  earthen- 
ware which  are  to  be  employed  in  preparing  condiments  for  nur 
food,  I  must  add  another  caution,  which  is,  never  to  prepare 
pickles  or  any  thing  in  which  linegnr  is  used,  in  jars  of  cream- 
coloured  ware ;  for  this  ware  is  always  glazed  with  lead,  and 
the  lead  being  soluble  in  vinegar  would  impart  a  poisonous 
<]uality  to  the  prep;iralions  contained  in  it.  When  will  the. 
community  entertain  propiT  notions  respecting  the  delete- 
rious properties  uf  thi^  msidious  poison  r  In  Lancashire  I  have 
observed  it  is  a  common  practice  to  have  brewing-coupcra  con'- 
stnicted  with  the  bottom  of  copper,  and  the  whole  sides  of  lead. 
In  the  same  county  the  dairies  are  furnished  with  milk-paiu 
made  of  lead  ;  and  when  I  expostulated  with  some  individuals 
on  the  danger  of  this  practice,  I  was  told  that  leaden  milk-pans 
throw  up  the  cream  much  better  than  vessels  of  miy  other  kind. 
In  some  parts  of  the  north  of  England  it  is  customary  for  the 


999  AOniTIONAL   NOTES. 

inn-keepeni  to  prepare  mint-salad  by  bruuJng  and  grin^g  At 
vegetable  in  a  large  wooden  bowl  with  a  bait  of  lead  of  twel« 
or  fourteen  pounds  weight.  In  this  opemtion  the  mint  is  cut, 
and  portions  of  the  lend  are  ground  off  at  everj- revolution  of 
the  ponderous  instrument. 

27.  ^ntimunij. — Page  HI,  line  13. 
The  pottern  generally  use  the  common  ntlphuret  of  nntimony, 
without  being  aware  of  the  quantity  of  snlphur  which  it  con- 
tains. As  this  u  the  cheapest  form  in  which  antimony  can  be 
obtained,  it  answers  very  well  for  some  purposee  ;  but  where 
fine  colours  are  required,  a  pure  oxide  of  anliniony  would  pro- 
bably  be  preferable,  as  the  presence  of  so  large  a  portion  rf 
sulphur  is  highly  injurious  where  a  beautiful  colour  is  designed 
to  be  obtained.  The  glass  of  ottlimony  would  surely  be  prefer- 
able to  tlie  siitphuret ;  for  Proust  has  determined  that  the  glaM 
of  antimony  consists  of  one  part  of  sulphuret  of  antimouy  com- 
bined with  eight  parts  of  the  pure  oxide  of  this  metal. 

It  is  well  known  that  a  custom  has  obtained  Irom  time  im- 
memorial among  the  Eastern  women,  of  tingeing  the  eyebrom 
and  eyelashes  with  some  metallic  ore  to  increase  their  bbdl- 
ness,  and  it  has  generally  been  supposed  that  this  was  dnlf- 
mong  3  but  from  some  circumstances  mentioned  by  tmvellen, 

rrlicularly  the  effect  which  candle-light  had  upon  the  colour, 
am  inclined  to  lielieve  that  the  article  employed  for  thit 
purpose  was  black-lead,  and  not  antimony.  See  Dr.  Shaw*! 
Travels  in  Barbanj  and  the  Ltn-ant,  page  229  ;  Lady  M.  W. 
Montague's  Leilers,  vol.  ii.  page  32  ;  and  Clnrke'a  edition  of 
Harmer's  Ohgervations  on  variout  Passages  of  Scripture,  vol,  if. 
page  334,  { 

28.  Printing  press, — Page  M-l,  line  20. 
If  we  consider  the  many  beautiful  coins  and  medals  whi<A' 
the  ancients  produced  when  the  Roman  empire  was  in  all  ili 
glory  ;  likewise  the  carnelian  and  agate  seals  which  they  en- 
graved for  stamping  on  soft  wax ;  together  with  the  practics 
which  was  very  general  among  that  people,  of  having  thdr 
names  impressed  in  coital  letters  on  the  large  earthen  jars  ia 
whkrh  they  kept  their  wine,  we  cannot  avoid  being  Kurpriud 
that  they  never  arrived  at  some  method  of  printing  books.  Aa 
interesting  dissertation  on  this  subject  may  be  seen  iu  the  PW- 
lotopkUal  Transactions,  No.  ^oO,  p.  38S  ;  or  in  Baddam's  Mf- 
moirs  of  the  Royal  SocUly,  vol.  x.  p.  459.  Procopius,  in  ha 
Hist.  Arcana,  says,  that  the  Emperor  Justin,  not  being  able  10 
write  his  name,  had  a  thin  piece  of  board,  through  which 
cut  boles  in  form  of  the  four  6rst  lelieis,  whii '  '  " 


r 


ADDITIONAL    NOTES. 


m 

paper,  iinil  served  to  direct  the  point  or  his  ptn.  Kor  the  date 
of  the  origin  of  printing  on  paper,  see  the  let  vol.  of  Ihece  Ea- 
snys,  p.  3. 

29.  Crucibkt  and  reior/j.— Page  J49,  line  fi, 

The  Indians  of  Louisiana  form  their  culinary  utensiU  with 
clay  mixed  with  a  sort  of  calcined  mica.  Of  tliis  composition 
they  also  make  crucililes  capable  of  enduring  the  strongest  heat 
they  can  produce.  The  f^alena,  which  is  found  there  in  abun- 
dance, is  fused  in  these  crucibles,  by  exposing  it  to  a  strong 
heat,  in  a  sort  of  funiace  made  by  excavating  a  bank  of  earth, 
and  forming  a  chimney  through  the  top  of  the  cave  to  produce 
a  strong  draught  of  air.  The  lead  thus  obtained  h  employed 
only  for  the  pur|X)se  of  sinking  their  fishing  nets. 

There  we  remains  of  many  ancient  potteries  in  tlie  neigh- 
bourhood of  Salem  in  the  United  States,  on  the  shore  of  lake 
Erie.  On  the  Ohio  and  Mississippi,  they  are  found  of  a  more 
recent  era.  In  the  ancient  sepulchral  barrows,  vessels  are  found 
equal  to  any  now  manufiiclured  in  any  part  of  the  world.  Two 
covers  of  vessels  were  found  in  Ross  county  highly  polished  nnd 
mode  ofa  calcareous  breccia;  fragments  of  these  were  examined 
by  my  friend  Professor  Silliman,  of  Yale  College,  Connecticut; 
and  were  found  to  be  ec|ual  in  texture  and  execution  to  ves- 
seb  of  a  similar  material  now  manufactured  in  Italy.  See  Ar- 
thaologia  Jmericana,  vol.  i.  pages  219 — 227. 

Directions  for  coating  and  preserving  stone  wore  retorts  are 
inserted  in  The  Reperlorif  of  Arlt  and  Manu/acturen,  vol.  i. 
page  310. 

30.  Old  pottery. —Page  j-lD,  line  23. 

The  introduction  of  old  ground  pottery  into  the  manulacture 
of  stone  chemical  vessels  was  a  great  improvement ;  but  I  am 
surprised  to  see  how  near  the  ancients  were  to  making  this  dis- 
covery. Pliny  says,  "  There  is  means  found  to  make  a  strong 
kind  of  mortar  or  cement  by  the  broken  aheards  of  potters*  ves- 
sels, if  the  same  be  ground  mto  powder  and  tempered  with  lime, 
and  the  ordering  it  in  this  manner  causeth  it  to  be  mote  firm 
and  last  the  longer,  and  such  they  call  s^iinn."  The  more  one 
reads  of  this  author,  the  more  astonished  one  is  at  the  extent 
■nd  variety  of  his  knowledge.  Pliny's  Natural  llhtory,  vol,  li 
book  XXXV.  chap.  1 2,  p.  55 1 . 

31.  jlncknl  wnlU. — Page  155,  line  5, 
For  information  relative  to  the  tise  of  volcanic  lomw  ni  em- 
ployed by  the  ancients  for  making  their  cost  ^-nulLi  and  walls. 
I  would  recommend  to  the  reader,  the  perusal  of  a  small  vo- 


598  ADDITIONAL   NOTES., 

lume  entitled  An  Account  of  some  German  Volcanoes  and  their 
Productions,  by  R.  E.  Raspe,  London,  octavo,  1776,  page  124, 
&c  ;  also  A  Dissertation  on  the  Roman  Walls  in  Britain,  in  the 
Appendix  to  the  second  volume  of  Henry's  History  of  Great 
Britain,  octavo,  page  469  ;  and  The  History  of  the  Roman  tt^aU 
which  crosses  the  Island  of  Britain,  by  W.  Hutton,  second  edition, 
octavo,  London  1813. 


NOTES  TO  ESSAY  XL 

ON    GLASS. 

32.  Coloured  glass. — Page  175,  line  11. 

Strabo,  who  visited  Alexandria  in  the  first  century,  was  toM 
by  the  workmen  there,  that  their  country  afforded  an  ingredient 
without  which  coloured  glass  couldnot  be  made.  Strabo,  lib.  xvi. 
page  758.  There  is  in  the  British  Museum  a  mummy  of  great 
antiquity  which  is  covered  with  beads  of  coloured  glass.  Ac- 
cording to  Seneca,  coloured  glass  has  been  made  in  Europe  for 
more  than  2000  years.  "  Democritus,*'  says  he,  **  brought  into 
Europe  the  method  of  making  coloured  glasses,  and  thereby 
counterfeiting  gems."     Seneca's  Epistles,  90. 

33.  Manganese, — Page  190,  line  9. 

For  a  further  explanation  of  the  action  of  the  black  oxide  of 
manganese  in  purifying  flint  glass,  consult  the  article  "  Glass" 
in  Aikin's  Chemical  Dictionary,  or  Loysel  Sur  I* Art  de  la  Ver- 
rerie,  page  J  68,  §  101.  When  too  much  of  this  oxide  has  been 
employed,  so  as  to  occasion  a  purple  colour  in  the  glass,  it  a 
usual  for  the  workmen  to  thrust  a  piece  of  wood  into  the  mass 
of  melted  metal,  which  quickly  abstracts  the  colour.  This  oxide 
imparts  its  colour  to  glass  only  when  it  Ls  in  a  high  state  of 
oxidizement :  the  wood  therefore  becoming  carbonized  abstracts 
a  part  of  the  oxygen,  and  the  colour  of  the  glass  disappears. 

34.  Virgits  glass  mirror. — Page  190,  line  2. 

This  must  have  been  an  uncommon  utensil  at  the  time  in 
which  Virgil  lived,  for  in  that  age  and  long  afterwards  mirrors 
were  usually  metallic.  Job  describes  the  heavens  as  a  molten 
looking-glass ;  and  by  the  order  of  Moses  the  brazen  laver  of 
the  priests  was  manufactured  with  the  mirrors  of  the  women 
assembling  at  the  tabernacle.  Exodus,  chap,  xxxviii.  verse  8. 
Valerian  made  the  Emperor  Probus  a  prcBent  of  a  silver  cup. 


ADUITIUNAL    NOTtS. 

the  iiuide  of  which  was  cut  into  mirroni.  I'liny  and  Scneta  re- 
late that  every  young  woman  in  their  times  expected  to  have  t, 
silver  mirror.  Ptiny,  hook  xxxiv.  chap.  17.  Indeed  the  mir- 
ror-maken  of  Home,  who  were  genemily  sJlversmithH,  were  so 
numerous  that  they  were  formed  into  a  company.  If  any  thing 
further  were  wanting  to  prove  that  the  most  ancient  mirron 
were  metalhc,  a  circumstance  might  be  mentioned  which  is  re- 
corded by  Martial,  of  a  lady  in  ancient  Kume  who  knocked 
down  her  hair-dresser  with  the  mirror,  because  he  had  not  put 
her  hair  into  that  form  which  she  preferred.  The  mirrors  of  the 
present  day  are  in  fact  all  metallic,  and  indeed  they  would  be 
of  little  use  if  it  were  not  for  the  metallic  cuat  at  the  back  of 
them.  For  a  method  of  laying  tinfoil  upon  the  backs  of  mir- 
ron, see  EncyclopMie,  mi  Diclionnaire  VnWemet,  Supplement. 
tome  vi.  page  G5-1. 

"  llie  ancient  inhabitants  of  some  parts  of  North  America 
employed  mirrors  of  isinglass  (iriicn  membranacea) ,  which  were 
mode  of  great  thickness.  Hnd  they  been  otherwise,  they  would 
not  have  reflected  the  light.  Such  mirrors  have  been  found  in 
6fty  different  barrows  in  that  country."  Arrhteologia  Ameri- 
cana, vol.  i.  page  225, 

35.  recAfiirnffermi.— Page  191,  line  23. 

'l*he  technical  terms  in  the  glass  trade  ore  most  of  them  taken 
from  the  Itnlian  or  French,  but  eome  are  derived  fi-dm  the  Ger- 
man language.  PontiUii  \s  from  the  Italian,  meaning  any  thing 
drawn  to  a  point  or  derived  from  a  point.  CacelUllii,  the  head 
or  crown  of  the  reverberatory  furnace,  is  also  from  the  Italian. 
Schroicer  is  the  room  at  the  end  of  the  tier,  where  the  goods  are 
received  when  annealed  -,  this  is  from  the  German.  Fraiclie  is 
the  iron  pan  in  which  the  glass  is  placed  to  be  cooled  or  an- 
nealed. ParceUas  is  a  kind  of  pincers  with  a  spring  back,  which 
is  in  constant  use  in  those  houses  where  flint  glass  is  made. 
These  terms  are  all  still  employed  by  the  glass-makers  of  Great 
Briuun. 

36.  rAediainofirf— Page220,  line4. 

There  is  something  very  mysterious  respecting  the  action  of 
the  diamond  in  cutting  glasN.  Any  person  observing  the  cer- 
tainty and  apparent  ease  with  which  a  skilful  glazier  performs 
that  operation,  would  imagine  it  to  be  no  more  difficult  than  to 
rule  lines  upon  paper  with  a  pen  or  a  pencil.  TTiere  is,  never- 
theless, scarcely  a  single  manual  operation  within  the  compass 
of  the  ordinary  arts,  which  requires  a  more  delicate  sleight  of 
hand.  liut  the  most  curious  circumstance  attending  it  is,  that 
if  the  surface  of  tlic  pane  of  glass  be  cut  or  scratched  with  the 


k 


em 


ADDITIONAL   NOTES. 


diamond,  the  glass  will  not  break  io  the  exact  line  which  the 
ditunond  has  market),  but  the  ftaelure  will  be  irre^lur,  and 
the  pane  in  al!  probnbilily  spoiled;  whereas  an  experienced  cut- 
ter will  divide  a  sheet  oi  glass  into  ns  many  squares  as  be  haa 
occasion  for.  without  imprinting  any  visible  murk  whalcrer  on 
the  surface ;  though,  if  the  sheet  of  glaw  he  esamioed  before  it 
is  actually  broken  into  its  intended  divisions,  it  will  be  srcn 
that  it  is  entirely  cut  through  except  at  the  uppermost  aiirfece- 

Not  be'mg  able  to  account  for  this  singnlar  circuinsUmce,  1 
consulted  b  gentleman  of  considerable  ac»)uirenient»,  one  of  the 
proprietors  of  the  Tyne  window-glass  works  ;  and  he  rety  obli- 
gingly furnished  nie  with  the  following  remarks  on  the  sut^eci : 
"  It  is  necessary,"  says  he,  "  that  the  diamond  ahonld  be  of  ■ 
regular  rhomboidBl  form  ;  or,  at  least,  that  it  should  have  coe 
regular  smooth  edge  and  rliomboidal  point,  of  which  the  angle* 
miMt  be  well  defined  and  of  a  particular  degree  of  aculenen.  A 
diamond,  or  spark  ns  it  is  railed,  wliirli  happens  to  be  rathn 
large  will  rarely  answer  on  this  account,  ita  angles  being  gene- 
rally too  obtuse. 

"  Jt  is  only  at  one  particular  point  that  the  diamond  will  pro- 
duce a  cut  i  and  this  point  depends  on  so  nice  a  degree  of  ob- 
tuseness  or  acuteness  in  the  angles  forming  the  extreme  point 
and  ridge,  that  it  can  be  only  guessed  at  before  trial  upon  llic 
glass  itself.  Any  deviatmn  of  the  diainond  from  one  paitirolar 
poNJtioii  nnd  inclination  to  the  surtisre  of  the  glass.  ocntsionFd 
by  the  minutest  variation  of  the  hand,  will  entirely  prevent  the 
cut.  It  may  appear  singular,  but  it  is  a  fact,  that  In  thin  respect 
the  ear  is  the  cutter's  sole  guide.  He  judge*  by  n  peculiar 
creaking  of  the  glass,  as  the  fracture  therein  pnrHoes  the  counc 
of  the  dmmond,  if  ila  inclination  be  correct ;  otherwise  he  vnrie« 
it  till  he  Rnds  it,  and  pursues  it  by  the  same  means  to  the  end 
of  the  cut.  He  cannot  leave  off  in  the  middle,  not  beinz  able 
Io  reproduce  a  cut  al  the  very  point  where  his  diamond  fint 
comes  in  contact  wHh  the  glass,  nor  o(  course  to  depend  en 
the  fracture  passing  out  of  one  into  the  other  line.  If  tkU 
peculiar  creaking  sound  be  not  produced,  the  effect  ia  only  a 
scratch  upon  the  surface,  such  as  is  made  by  the  diamonds  set  , 
for  the  purpose  of  merely  writing  upon  glass  ;  and  it  is  in  min 
to  expect  the  fracture  to  follow  the  course  of  this  line. 

"  Wliere  llie  cut  is  perfectly  good,  it  should  be  an  internal 
fracture  unaccompanied  with  any  scratch,  or  any  visible  tmpret- 
sion  upon  the  surface  whatever ;  fer,  in  proportion  as  any  such 
superficial  injury  is  produced,  the  coroplelencss  of  the  inicmil 
fraclure  Is  diminished.  This  fracture,  therefore,  which  w  ctdleif 
n  cut  from  its  resemblance  thereto  in  its  effect,  as  also  in  the  si- 
milarity of  itt  appeaiance  to  n  rent  cut  prtKtiiced  on  iny  otiltr 


ADDITIONAL   NOTES. 

substance  by  n  sliarp-edged  insirumcnl,  but  which  lias  cluscil 
again,  (the  ex[>ression  being  further  counlpnanced  \iy  the  nharp 
rorm  of  that  part  of  the  liiamond  which  comes  in  contact  with 
the  glass,}  is  redly  no  cut  Ht  uti,  nor  does  the  diamond  »o  much 
as  enter  the  surface. 

"  The  reason  why  the  internal  fracture  is  imperfect  in  propor- 
tion as  the  surface  is  injured,  appears  to  be,  that  the  injury  of  the 
surface  h  nothing  else  than  the  <lislocation,  in  small  conchuidat 
fragments,  of  such  particles  as  the  dianwnd  comes  succcKively 
in  contact  with,  by  which  its  perpendicular  pressure  is  eluded,  or 
dissipated  laterally  in  producing  those  smaH  e\cavations  orfrai- 
lurcs,  taking;  a  direction  immediatelv  back  to  the  surface. 

"  The  diamond,  apparently,  wears  down  its  cutting  point  by 
long  use,  though  it  will  stand  the  work  of  an  ordinary  glazier 
for  many  yearn  ^  and  the  change  nt  tost  is  not  visible  to  the  eye, 
und  only  apparent  by  its  being  no  Ioniser  fit  to  produce  a  ctil. 
No  endeavour  hath  hitherto  succeeded  In  forming  an  artificial 
cutting  point ;  which  is  not  to  be  wondered  at,  since  we  know 
that  a  change  of  form  not  perceptible  to  the  eye  is  sufficient  lo 
destroy  the  effect. 

"The  breakage  made,  even  at  the  manufactories,  by  the 
most  practised  cutters,  arising  from  the  delicacy  necessary  to 
be  observed  in  the  use  of  this  inBtruraent,  is  very  considerable  ; 
and  that  mode  by  glaiitrB  in  {^ncml.  wht>  being  )e^s  practised 
operate  with  timidity,  is  mucli  more  so.  It  was,  therefore, 
very  natural  that  attention  should  be  directed  to  the  means  of 
givmg  this  operation  n  mechanical  precision ;  but  nothing  suc- 
cessful was  attained  till  about  the  year  1814,  when  letters  pa- 
tent were  granted  for  instruments  by  which  this  object  is  at 
once  carried  to  perfection.  By  the  use  of  one  of  these  instru- 
ments, n  person  not  nt  all  accustomed  to  a  diamond  may  pro- 
duce a  j>erfeci  cut.  over  a  table  of  glass  so  uneven  in  iLi  surface 
that  the  most  skilful  workman  with  n  common  glazier's  dia- 
mond would  not  be  able  to  produce  a  cut  of  anykind  upon  it. 
This  consists  in  giving  the  diamond  perfect  play,  and  at  the 
same  time  affording  it  such  guides  and  support  as  effectually 
prevent  It  from  being  affected  by  the  unsteadiness  of  the  hand 
or  unevenness  of  surface,  in  respect  of  its  inclination  lo  the 
plane  of  the  table  ;  whereby  the  diamond,  being  once  well  set 
or  mounted  in  iiA  carriage.  Womes  equally  certain  in  the  hands 
of  every  person. 

"  This  patent  instrument  is  now  sold  upon  constructions  va- 
riously modified  by  Henrv  Hammond  and  Co.  at  their  window- 
^lasB  warehouse.  No,  12'",  High-Holbom,  these  persons  being 
principnily  int^rtsml  in  the  potent  right." 


602  ADDITIONAL  NOTfi8. 

Having  examined  some  of  these  patent  instruments  myuM, 
1  think  it  right  to  say  that  the  invention  appears  to  me  to  be 
very  ineenious^  and  that  this  or  some  other  instrument  cod- 
structed  upon  a  similar  principle  will  supersede  the  *  diamondi 
in  common  use.  This  little  implement  was  invented  by  an  in- 
genious watch-maker  in  Leicestershire,  of  the  name  of  Shaw, 
who  was  led  to  the  consideration  of  the  subject  by  the  desire 
of  a£Fording  some  assistance  to  a  relative  who  is  a  glazier,  and 
who,  in  consequence  of  a  paralytic  affection  of  the  hand,  had 
found  a  difficulty  in  cutting  his  glass  by  the  usual  method. 

Since  the  first  publication  of  these  remarks.  Dr.  Wollaaton 
has  made  some  experiments  on  cutting  with  the  diamond,  and 
has  read  a  paper  on  the  subject  to  the  Royal  Society.  He 
found  how  extremely  difficult  it  is  for  a  person  unaccustomed 
to  the  use  of  a  diamond,  to  cut  with  it.  He  says,  "  Although 
I  could  tear  the  surface  to  a  considerable  depth,  I  could  by  no 
means  command  the  direction  of  the  fracture.**  The  Doctor's 
paper,  which  contains  much  curious  matter,  will  be  found  in 
the  Philosophical  Transactions  for  1816,  vol.  cvi.  pages  265— 
269.  It  is  entitled  "  On  the  Cuttmg  Diamond.*'  It  was  read 
to  the  Society  on  the  second  of  May  18 16. 


NOTES  TO  ESSAY  XII. 

ON    BLEACHING. 

37.  A  fuller. —Vage  338,  line  5. 

The  anecdote  to  which  I  allude  in  this  note  is  told  by  Apuleius 
at  great  length.  The  substance  of  it  is  this  :  that  the  fuller  un- 
expectedly bringing  home  a  friend  to  sup  with  him  at  the  in- 
stant when  the  wife  was  engaged  with  her  gallant,  she,  on  the 
sudden  alarm,  hides  him  in  a  wicker  apparatus  which  had  just 
been  employed  to  bleach  garments  by  the  fumes  of  burning  sul- 
phur.— Contegit  viminea  cavea ;  qu€B  lacinias  drcumdatas,  suf- 
fusa  candido  Jumo  sulfuris,  inalbabat.  Presently,  while  they  are 
at  supper,  the  gallant,  stifled  with  the  fumes,  sneezes  aloud  -,  the 
fuller  removes  the  coop,  and  the  poor  panting  half-smothered 
culprit  is  discovered.  Apuleius  De  Asino  aureo,  edit.  Scriverii, 
Amst.  1624,  lib.  ix.  p.  136. 

38.  A  line  of  coloured  threads, — Page  350,  line  8. 
In  recommending  the  practice  of  running  a  line  or  two  of 


r 


ADDITIONAL   NOTES.  603 

raat-dyed  coloured  threads  along  one  uf  the  edges  of  all  cali- 
coes, dimities,  &c.  it  may  appear  that  I  advised  the  Adoption  of 
this  method  on  printed  aa  well  ok  on  plain  calicoes  ;  I  therefore 
embrace  the  opportunity  which  thb  Appendix  sifords  me,  of 
distinctly  stating,  that  the  expedient  to  which  1  refer  can  never 
be  of  any  use  for  printed  cottons,  neither  had  I  tliem  in  my  mind 
when  I  gave  the  recommendation,  because  1  well  know  that  the 
>'aned  processes  to  which  white  calicoes  are  usually  submitted 
by  the  printer,  would  inevitably  destroy  the  indigo  blue  and 
|)robably  the  Turkey  red  line  also.  It  can  be  of  use,  as  a  test 
of  gooci  bleaching,  only  on  Nuch  goods  as  are  intended  to  re- 


NOTKS  TO  ESSAY  XIII. 


39,  Green  vegetable  matter. — Page  388,  line  H. 
"  The  tranaition,"  says  Sprengel,  "  of  one  organical  kingilom 
of  nature  into  the  other,  and  the  impossibility  of  separating  the 
two  bynn  exact  line  of  demarcation,  becomes  obvious  to  those 
who,  with  Needham,  Hriratley,  and  Ingenhousz,  have  observed 
the  metamorphosis  of  the  anitnalcula  infusoria  into  real  con- 
lervK.  To  mejie  this  experiment,  no  particular  infusions  are  re- 
quired i  a  vessel  filled  with  pump-waler,  and  e<i])05ed  to  the 
sun,  without  being  agitated,  Ls  sufficient  for  the  purpose.  First 
of  all,  a  delicate  green  covering  is  seen  to  be  formed  on  the  sur- 
foce  of  the  water,  consisting  of  numberless  and  infinitely  mi- 
nute molecules,  that  manifest  animal  motion  ;  the^e,  after  some 
time,  disappear,  and  are  transformed  into  vegetable  filaments, 
which,  like  all  green  surfaces  of  plants,  yield  oxygen  gas  when 
exposed  to  the  influence  of  the  sun."  Sprengel's  fnlrorfuction 
to  thr  Sludg  of  Cri/ptogamous  Planti,  ocUvo,  London  1810, 

40.  Lead  nil  iiuidioM  pviton. — Page  286,  line  10. 
In  the  province  of  Pnitou  there  was  formerly  a  disease  called 
the  colic  of  Poituii :  but  this  is  no  lunger  common  either  in 
France  or  Germany,  Bince  the  lun-s  of  these  countries  have 
made  the  adulteration  of  wine  with  lead,  punishable  by  death. 
A  similar  disease  was  prevalent  in  the  counties  of  Hereford, 
Gloucester  and  Worcester,  when  leaden  utensils  were  emploved 
in  making  ctder.  Ur.  Baker,  who  was  physician  to  Her  late 
Miqesty.  thcQuccn  of  George  III.,  relates  that  this  disenaeWM 


604  ADDITIONAL   MOTXS. 


prevalent  in  the  cider  districtfi  of  Devonshire,  and  that 
on  inquiry  he  found  the  stones  which  compose  the  diodsr 
troi^  in  which  the  i^les  are  groond,  to  be  crannied  together 
by  iron^  with  melted  lead  poored  into  the  interatices  ^  and  sko 
that  many  dder  presses  were  to  be  seen  whidi  were  lined  en- 
tirely with  lead.  Dr.  Saunders  actoaily  procmned  4^  grains  of 
lead  from  18  quarts  of  Devonshire  bottled  cider. — See  At^  Eumf 
on  the  Endemicd  Colic  nf  Devonshire,  by  George  Baker,  M  J>. 
London  1767.  Dr.  Franklin  has  stated,  that  leaden-vfonas 
were  formeriy  used  at  Boston  in  America,  for  the  djatfllatam  of 
rum,  and  that  such  disorders  were  produced  in  consequoice  of 
this  practice,  that  the  Government  found  it  expedient  to  enact 
a  law  forbidding  the  use  of  any  worms  for  stills  except  such  only 
as  were  made  of  pure  tin.  Some  interesting  observations  oa 
the  danger  of  employing  leaden  vessels  for  holding  water,  or  for 
culinary  purposes,  will  be  (bund  in  Dr.  Lambe*s  Essay  on  ike 
Properties  of  Spring  Water,  8vo,  1803. 

41.  The  fullers  in  ancient  Rome. — Page  378,  line  18. 

The  inhabitants  of  Rome,'  except  the  lower  orders  of  people, 
generally  wore  white  woollen  gannents,  but  especially  at  pub- 
lic festivals.  Ovid  Fasti  i.  79.  This  made  fullers  as  necessary 
as  laundresses.  They  were  for  the  most  part  slaves,  but  some- 
times free ;  for  an  inscription  in  the  collection  of  F&brettus,  c.  4. 
page  333,  mentions  the  Collegium  PuUonum,  the  Fullers*  Cohh 
pony  at  Rome.  The  place  where  the  fullers  worked  was  gene- 
rally in  the  fields,  on  account  of  the  offensive  nature  of  their 
business.     Hence  Plautus  Asin,  V.  ii.  57. 

It  appears,  from  the  testimony  of  ancient  writers,  that  the 
fullers  first  threw  the  clothes  into  water,  where  they  trod  them 
with  their  feet.  Hence,  as  Horapollo,  Hieroglyphics,  i.  65,  has 
observed,  the  Egyptians  expressed  a  fuller  by  the  representa- 
tion of  two  human  feet  in  water.  This  washing  by  treading 
with  the  feet,  the  Romans  called  Consilium,  d  ConsiUendo.  In 
order  to  provide  themselves  with  urine,  the  fullers  placed 
earthen  pitchers  at  the  comers  of  the  streets.  See  Martial  xii.58. 

The  clothes,  having  been  thus  repeatedly  trodden  upon  in 
water  and  urine,  were  laid  upon  a  block  and  beaten  with  staves 
or  battledors.  It  was  with  one  of  these,  acco^ing  to  a  fragment 
of  Hegesippus  preserved  by  Eusebius,  that  the  Jews  beat  the 
i^)08tle  James  the  younger  until  he  died.  When  the  dotbtt 
had  been  trodden  and  beaten,  they  were  hung  up  for  the  water 
to  drain  from  them.  They  then  scoured  them  with  fullers*  earth 
^nd  a  portion  of  nitre  :  after  this  they  fumigated  them  with  sul- 
phur ',  then  they  carded-  them  with  a  sort  of  thistle,  and  last  of 


ADDITIONAL    NOTES. 

all  they  applied  challc  in  some  way  or  other  to  brighten  the  co- 
lour,  as  Fliny  says  sxxv.  17.  Fcro*  autem  et  pret'tMOt  coloreg 
fmoUil  cmolia,  el  quodam  colore  eihilarat  conlrittatoii  tutphure. 
Schoeltgenio  On  the  ancient  Metlioda  of  Fulliag.  See  aUo  7^ 
pretenl  StaU  of  the  Repubik  of  LeHert.  »ol.  i.  page  150. 

42.  Erpannon  of  water. — Page  4 1-3,  line  6. 


It  has  been  observed  that  stone  buildings  are  generally  most 
decayed  on  that  side  which  faces  the  north.  I  think  lhi<i  may 
he  attributed  to  the  expansion  of  the  water  within  the  stone  du- 
ring the  act  of  freezing.  Thus  the  external  atones  of  bridges 
become  saturated  ivith  water  when  the  river  rises  just  before 
the  commencement  of  a  very  severe  frost ;  and  when  tlie  river 
subaides,  the  water  within  their  pores  suddenly  freezes,  and  this 
action  bursts  the  stone  in  all  oirections.  Aware  of  thb  effect 
of  frost,  the  proprietors  of  the  Strand-bridge,  over  the  Thames 
nt  London,  have  chosen  Scotch  granite,  which  being  impervioua 
to  water  con  never  be  injured  in  this  way. — The  other  three 
large  bridges  in  the  metropolis  arc  built  with  Portland  stone, 
and  these  are  all  rapidly  decaying. 

43.  Proceuei  of  decoction,  dUtUlalion,  lie. — Page  433,  line  14. 

Steam  has  long  bpeii  employed  for  the  purposes  of  evspon- 
tion  and  distillation  in  the  laboratory  belonging  to  the  Apothe- 
caries' Company  of  London  ;  and  very  lately  its  use  has  been 
considerably  extended,  and  n  more  complete  apparatus  for  ef- 
fecting a  great  variety  of  processes  of  solution,  evaporation, 
and  dlitillation,  by  the  agency  of  steam,  has  been  erected.  This 
extensive  apparatus  won  constructed  by  Mr.  Mtunwnring  under 
the  direction  of  W.  T.  Brande,  Esij,,  who  has  furnished  me  wiA 
the  following  description  of  the  whole  : 

The  steam  laboratory  is  a  brick  building  lighted  from  above, 
about  50  feet  long,  lofty  and  well  ventilated  by  apertnres  in  the 
roof.  The  steam  is  supplied  from  two  boilers  placed  in  build- 
ings separate  from  the  laboratory ;  the  largest  of  which  is  of 
the  common  waggon  shape,  made  of  copper,  and  calculated  for 
the  supply  of  a  si-c-horse  steam  engine.  It  is  furnished  with  a 
float-stone,  which  acts  by  means  of  a  lever  u|>on  an  index  placed 
in  the  laboralor)-  for  the  purpose  of  showing  the  level  of  the 
water ;  vrith  a  mercurial  gauge  indicating  the  pressure  of  the 
steam,  which  is  usually  worked  at  between  7  and  8  inches; 
and  with  a  safety  valve  which  opens  whenever  the  prcsmre  ex- 
ceeds that  which  is  capable  of  supporting  12  inches  of  mercury 
in  the  syphon.     A  f<»rcing-pump  is  aho  annexed  to  the  boiler. 


606  ADDITIONAL  NOTES. 

by  which  it  is  occasionally  supplied  with  hot  water  resulting 
(ram  the  condensation  of  the  steam  in  the  various  vessels. 

The  main  steam  pipe,  which  is  6  inches  in  diameter,  is  con- 
ducted round  the  laboratory  in  a  cavity  of  brick-work  covered 
by  moveable  cast-iron  plates,  and  is  accompanied  by  a  smaDei 
pipe,  which  receives  and  conveys  the  water  resulting  from  tiie 
condensation  of  the  steam  into  a  dstern  properly  supplied  with 
valves,  whence  it  is  occasionally  pumpea  back  into  the  boiler. 
A  small  steam  pipe  with  a  register-cock  passes  to  each  of  the 
stills  and  evaporators,  each  of  which  also  sends  off  a  condensed 
liquor-pipe  into  the  main  for  its  reception. 

The  boilers  and  evaporators  are  twelve  in  number  :  4  are  of 
pewter,  1  of  iron,  and  7  of  copper.  Four  of  these  are  cBfMt 
of  holding  from  150  to  300  gallons;  four  contain  about  100 
gallons ;  and  four  from  10  to  20  gallons  :  there  are  also  some 
smaller  vessels  of  the  same  kind,  generally  used  as  water  batio. 

The  stills  are  seven  in  number  :  of  these  the  largest  contttns 
500  gallons,  and  has  a  distinct  worm-tub  3  two  contain  200 
gallons  each,  and  one  contains  150  gallons ;  these  are  of  a^ 
per.  There  is  also  a  pewter  still  of  about  30  gallons,  and  one 
of  lead  for  the  distillation  of  ether.  These  5  stills  have  two  con- 
densing tubs.  Lastly,  there  is  a  still  which  with  its  head  and 
worm  are  entirely  of  stone-ware  }  it  is  chiefly  employed  for  di- 
stilling spirit  of  nitric  ether. 

With  the  exception  of  the  leaden  ether-still,  all  the  above 
vessels  are  heated  by  the  circulation  of  steam  upon  their  exte- 
rior, being  coated  with  cast-iron  jackets,  and  having  a  space 
between  the  two  of  about  half  an  inch  diameter,  into  which  the 
steam  passes  from  the  main  by  the  reg^ter  cocks,  and  from 
which  the  condensing  pipes  pass  off.  A  blow-cock  is  attached 
to  each  vessel,  to  allow  of  the  escape  of  the  air  when  the  steam 
is  first  turned  on. 

The  other  boiler  above  adverted  to  is  calculated  for  the  pro- 
duction of  high-pressure  steam,  with  a  pressure  of  100  lbs.  on 
the  square  inch  -,  it  is  applied  in  another  part  of  the  building 
to  various  purposes  of  evaporation,  solution,  decoction,  &c.,  ana 
in  addition  onlv  supplies  the  ether  still  in  the  steam  laboratory, 
which  is  heated  by  a  coil  of  leaden  pipe  by  which  the  tempera- 
ture requisite  for  the  production  of  ether  from  alcohol  and  sul- 
phuric acid  is  obtained.  The  waste  steam  of  these  boilers  is 
condensed  into  a  large  cistern  of  water  in  another  part  of  the 
building. 

Independent  of  the  saving  of  fuel  in  consequence  of  the 
employment  of  steam  as  above  described,  there  result  from  it 
other  more  important  advantages,  such  as  safetv  from  fire  in  the 


ADDITIONAL   NOTES. 

(ItsdllBtion  of  spirituous  acid  ethereal  preparntions  ;  prevention 
oi  burning  or  orempyreumu  in  the  evaporation  of  extractn  ;  and 
exclusion  uf  the  duat  and  smoke  which  fires  under  the  separntv 
vessels  would  necessarily  occnalon. 

Besides  the  distillatory  and  evaporatory  appnmtuB,  there 
are  also  two  large  drying  stoves  heated  by  steam,  and  seveml 
wooden  and  other  vessels  for  saline  solutions,  &c.  which  are  oc- 
CMionally  adapted  to  the  steam  apparatus,  and  heated  by  an 
immense  coil  of  leaden  pipe. 

This  lengthened  description  of  the  apparatus  at  ApothecarieK' 
Hall  hna  been  given  for  the  purpose  of  showing  the  great  trco- 
nomy  of  using  steam  in  all  the  common  operations  of  a  chemi- 
cal labomtory.  Another  expedient  for  evaporating  heavy  or 
viscous  fluids  with  safety  and  economy,  has  ^o  been  lately  in- 
troduced, which  consist!)  in  making  oil  at  a  high  temperature 
the  medium  hy  which  Ihe  heat  is  conveyed. 

In  the  refining  of  sugur,  great  inconvenience  had  arisen  frum 
the  circumstance  of  the  sugar  being  usually  boiled  by  a  naked 
fire,  which  generally  bums  a  port  of  the  sugar,  and  occasions  a 
portion  of  the  remainder  to  be  converted  into  raolasaes,  which 
IS  more  a  product  of  the  fire  than  n  natural  educt  from  the  ran 
sugar.  In  consequence  of  this,  Mr.  Daniel  Wilson  invented  a 
mode  of  boiling  sugar  in  coppers  without  lire-places,  merely  by 
forcing  heated  whale-oil  through  a  coil  of  metallic  pipes  lying  in 
the  mid§t  of  the  syrup  within  the  boiler. 

For  a  full  account  of  this  important  apparatus,  which  in  my 
opinion  might  be  employed  with  great  advantage  in  many  pro- 
cesses besides  that  of  refining  sugar,  the  reader  is  referml  to 
an  octavo  volume  entitled  j1  Report  of  the  Trial  of  the  jlctUin 
braught  bg  Mestrs.  Severn,  King  and  Co,  againit  the  Imperial 
liauranee  Company,  before  Lord  Chief  Justice  DalliiM  and  a 
Special  Juri/.SiC.  and  to  some  papers  of  mine  in  the  30th,  21st, 
and  23d  Numbers  of  the  Jimmal  of  Science,  Literature  and  the 
Arl>.  edited  at  tlie  Royal  Institution  of  Gnat  Uritoin.  The  uses 
of  the  several  iiartu  of  the  Ap|iaratus  will  be  easily  understood 
by  referring  to  the  I'late  No.  III.  and  to  the  "  General  Expla- 
nation uf  thf  Plates"  in  thin  volume. 


608  ADDITIONAL  NOT£S. 

NOTES  TO  ESSAY  XIV. 

ON   SAL-AMMONIAC. 

44.  Knoum  to  the  ancients. — Page  437,  line  2. 

It  was  not  until  after  the  Essay  on  Sal-ammoniac  was 
that  I  bcx»me  acquainted  with  Professor  Beckmann*s  opinion 
respecting  the  pretended  antiquity  of  this  salt.  My  readea 
must  however  now  be  informed^  that  this  learned  man  has  as* 
serted  that  the  sal-ammoniac  of  the  ancients  was  nothin|^  moit 
than  impure  marine  salt.  He  acknowledges  the  name  is  old; 
but,  says  he,  '^  as  those  who,  in  consequence  of  the  name,  oqb- 
sidered  the  alumen  of  the  ancients  to  be  onr  alum,  and  their 
futrum  to  be  our  salt-petre,  were  in  an  error,  we  shooU  be 
equally  so  were  we  to  consider  their  sal-ammoniac  to  be  the 
same  as  ours.*'  Dioscorides  and  Pliny  speak  of  sal-ammonjac 
in  some  places  as  though  it  were  common  salt )  but  Pliny  sayi 
flJso  that  it  was  found  in  the  dry  sandy  deserts  of  Africa,  as  nr 
as  the  oracle  of  Ammon ;  and  on  the  other  side  of  the  question. 
Columella,  in  a  prescription  for  the  eye,  recommends  rock-saU, 
either  Spanish^^ifimoniocoi,  or  Cappadocian^ — See  Beckmann*8 
History  of  Inventions  and  Discoveries,  London  1814,  vol.  iv. 
page  360.  Sal-ammoniac  was  however  most  certmnly  known 
m  the  15th  century,  as  Agricola  describes  it  as  a  salt  entirely 
dissipated  in  the  fire,  and  as  employed  in  the  production  of  a 
celestial  blue  colour;  and  Biringoccio,  who  wrote  in  1540,  re- 
commends nitric  acid  prepared  with  sal-ammoniac  for  dissolviag 
gold. 

45.   Uses  of  ammonia. — Page  445,  line  16. 

In  addition  to  the  list  of  uses  of  ammonia  which  I  have  eou- 
merated,  1  wish  to  notice  that  a  modem  traveller  has  related 
the  case  of  an  Indian  who  was  bitten  by  a  rattle-snake,  and 
perfectly  cured  in  a  few  days  by  the  external  and  internal  use 
of  volatile  alkali  alone,  although  the  poor  creature  lay  at  the 
point  of  death,  and  betrayed  the  most  dreadful  symptoms.  The 
writer  recommends  the  trial  of  the  volatile  alkali  also  for  the 
cure  of  hydrophobia.  "  If  (says  he)  the  poison  which  is  com- 
municated by  the  bite  be  of  an  acid  nature,  no  remedy  can  be 
more  efficacious,  nor  exert  a  more  direct  action  on  the  destruc- 
tion of  this  poison,  than  ammonia,  which  would  neutralize  the 
animal  acid ;  but  hitherto,  I  believe,  the  experiment  has  not 
been  made." — Travels  in  South  America  by  Don  Felix  di  Azara, 
4  volumes  octavo,  Paris  1809. 


ADDITIONAL    NOTES. 


G09 


46.  jiniinal  bonei. — Page  4-16,  line  23. 
"  Having  awn,"  snya  Van  Bmam,  "  a  pretty  large  veuel  go 
by,  Inden  with  the  bonea  of  animnlx,  1  was  desirous  or  knowing 
for  what  purpose  they  were  intended  ;  and  wan  tuld  that  they 
lire  to  be  burnt,  and  that  the  cindera  ore  to  be  put  on  the  ground 
fown  with  rice,  when  the  plant  is  about  a  foot  high,  and  before 
the  water  is  let  into  the  fields." — Van  Brunm's  Kmbiuig  ta  thi 
Court  of  Ihe  Emperor  of  China,  vol.  ii.  JJage  147-  There  are 
few  rehiee  articles  which  afford  a  better  manure  than  bonea  ; 
but  1  iihould  be  glad  to  Vnow  whether  the  Chinese  hure  din- 
covered  a  ihethod  of  procuring  carbonate  of  ammonia  from  them, 
1  am  pereuadcd  that  no  animal  matter  whatever  ought  to  be 
despised  by  the  maker  of  sal-ammoniac;  especially  ifhismanu- 
bclory  is  situated  in  a  country  where  mineral  coal  w  rot  (o  be 
procured  :  even  the  oldest  and  the  driest  bonea  will  yield  a 
considerable  quantity  of  ammonia. 


NOTES  TO  ESSAY  XV. 


L 


4".  Initrumml*  of  tttme. — Page  472,  line  8. 
In  the  1st  volume  of  the  Tramaclinm  of  the  American  Aali- 
guarian  Socitig,  an  antique  axe-head  is  described,  made  of  a 
Mpecics  of  green  stone  equal  to  ^Egyptian  gnintte  and  jralixhed 
in  the  neatest  manner.  In  the  same  work  mention  is  made  of 
a  fi«h->ipear,  with  six  or  seven  long  prongs,  perfectly  separated 
and  baH>ed,  carved  out  of  calcedony.  It  is  difficult  to  conceive 
how  such  instruments  could  have  been  made  even  by  means  of 
steel  instruments.     Page  230. 

48.  Oold  and  ji/ier.— Page  477,  line  13. 
The  lavish  employment  of  these  precious  metals  by  the  an- 
cienbt  is  recorded  by  all  the  early  hiKtorians.  A  few  instances 
may  be  adduced.  The  first  anchors  were  not  made  of  iron,  but 
of  stone,  and  sometimes  of  wood.  These  latter  were  loaded 
with  lead.  Several  writers  relate  that  the  Phienicians,  in  their 
first  voyages  into  Spain,  having  amassed  more  silver  than  their 
■hips  could  contain,  took  the  lead  from  their  anchors,  and  sup- 
plied its  place  with  silver.  Goguet's  Origin  of  Lawi,  he.  vol.  i. 
page  292  E)iodorus  says  that  "  the  tomb  of  King  Simandius 
was  environed  with  acirele  of  gold  three  hundred  and  siMy-five 
VOL.    II.  2  K 


610 


ADDITIONAL   NOTES; 


cubits  about,  and  tt  foot  and  a  half  thick. "  "  Semirarais  erected 
in  Babylon  three  statues  of  gold,  one  of  which  was  forty  fett 
high  and  weighed  a  thouaand  Babylonian  talents.  For  lhe»e 
statues  there  was  a  table  or  altar  of  gold  forty  feet  long  aad 
twelve  feet  broad,  weighing  fifty  talents."  Cogan's  Diodonu 
Sicului,  folio,  pages  34  and  '6.  We  read  that  Solpmon  receiwd 
666  talents  of  gold  (more  than  27  tons  weight)  in  one  yew, 
1  Kings,  ch.  \.  ver.  i4.  llie  historian  proceeds  to  relate (hii 
"  all  his  drinking- vessels  were  of  gold,  and  all  the  vessels  of  tt* 
bouse  of  the  forest  of  Lebanon  were  of  pure  gold,  none  were  tl 
silver  ;  it  was  nothing  accounted  of  in  the  dava  of  Soloinon." 
Ibid,  verse  2 1 .  Herodotus  informs  us  that  the  Scythians  placed 
cups  of  pure  gold  in  the  sepulchres  of  their  kings.  We  are  nbe 
told  by  Pliny,  that  his  contemporaries  employed  the  predou 
metals  in  great  abundance  for  omumenting  their  horses  i 
carriages.  Nero  and  his  Empress  shod  their  favourite  hor 
with  gold  and  silver. 

A  very  remarkable  instance  of  profusion  in  the  use  of  golda 
recorded  in  a  letter  from  Paul  DemidoiT,  Esq.  at  Petersburg.^ 
Mr.  Peter  Collinson,  dated  September  17th,  1764,  and  is 
served  in  the  2nd  volume  of  the  jlrr.haologia.     "  In  the  d 
which  constitutes  the  southern  boundary  of  Siberia  at  50  NoH 
latitude,  between  the  rivers  Irtish  and  Obalet,  are  many  tu 
or  barrows,  where  the  borderers  have  long  been  in  the  pra 
of  digging  for  treasures.     The  Russian  court,"  says  Mr.  D 
doff,  "  being  informed  of  these  depredations,  sent  a  princi 
officer,  with  sufficient  troops,  to  open  such  of  these  tumuUflj 
were  too  large  for  the  marauding  parties  to  undertake,  and] 
secure  their  contents.     This  officer,  on  taking  a  su 
numberless  monuments  of  the  dead  spread  over  this  great  4 
sert,  concluded  that  the  barrow  of  the  largest  dimensioi 
probably  contained  the  remains  of  the  prince  or  chief : 
was  not  mistaken  ;  for,  after  removing  a  very  deep  covering 
earth  and  stones,  the  workmen  came  to  three  vaults,  constm 
ed  of  stones,  of  rude  workmanship  ;  of  which  a  view  is  exhibit 
in  the  engraving.      That  wherein  the  prince  v/a»  deposiM 
which  is  the  centre,  and  the  largest  of  the  three,  was  easily  J 
Etinguished  by  the  sword,  spear,  bow,  quiver,  and  arrow  wv 
lay  beside  him.     In  the  vault  beyond  him,  towards  which  I 
feet  lay,  were  his  horse,  bridle,  saddle,  and  stirrups.    The  b  ' 
of  the  jprince  lay  in  a  reclining  posture,  on  n  »Aief  of  pure  g 
extending  from  head  to  foot,  and  another  sheet  of  gold,  a 
like  dimensions,  was  spreud  over  him.     He  was  wrapt  in  i 
mantle  bordered  with  gold,  and  atudded  with  rubies  and  ( 
raids.     His  head,  neck,  breast,  and  arms  tiakcd,  aad  w 


r 


ADDITIONAL   NOT£S. 


any  ornament.  In  the  lesser  vault  lay  the  princess,  dUlin- 
guished  by  her  female  ornaments.  She  was  placed  reclining: 
a^nst  the  wall,  with  a  gold  chain  of  many  links,  set  with  ru- 
bies, round  her  neck,  and  gold  bracelets  round  her  arms.  The 
head,  breast,  and  arms,  were  naked.  The  body  was  covered 
with  a  rich  robe,  but  without  any  border  of  gold  or  jewels,  and 
was  laid  on  a  ihcet  of  Hue  gold,  and  covered  over  mth  another. 
The  four  sheets  of  gold  weighed -lOIbs.  The  robes  of  bolh  looked 
fnir  and  complete  j  but,  on  touching,  crumbled  into  dust."  See 
"  An  Account  of  certain  Tartarian  Antiquities,"  with  a  copper- 
[riate  engraving  of  the  bturow  containing  the  Prince  and  Prin- 
cess with  their  habilioienls,  4c. — Jrclurologia,  vol.  ii.  page  22:i. 

49.  Obelisks  nf  porphijTy. — Page  479,  line  7. 
Diodorus  relates,  that  "  at  the  entrance  of  the  sepulchre  of 
King  Simandius  waii  a  gate  of  porphyry  480  feet  long,  and  ()72 
ficet  high."  Cogan's  £>io(Juruj  Sicu/uj,  page  32.  Lord  Valentia 
relates,  that  "at  Axnm  are  the  ruins  of  a  great  number  of  obe- 
lisks, some  of  which  have  been  Sculptured,  while  olhera  have 
not.  The  beautiful  one  which  remains  erect  has  been  very  in- 
correctly delineated  by  Bruce  ;  but  Mr.  Salt,  who  was  attracted 
to  it  by  its  grandeur,  has  given  an  elegant  drawing  of  it.  7'hough 
nearly  SO  Jeet  high,  it  is  formed  of  a  single  block  of  granite, 
curiously  carved,  and  in  excellent  proportions.  No  decisive 
opinion  can  be  formed  of  its  antiquity. "  Lord  Valentia's  Voy- 
ages and  Travtln  to  India,  Ceyltm,  tile  Red  Sea,  Alymnia,  and 
Egypt,  3  voU,  quarto,  London  1809. 

|i  There  are  three  celebrated  obelbks  of  porphyrjj  in  Egypt, 

called  the  Needles  of  Cleopatra.     One  of  these  is  at  Grand 

i  Cairo,  the  other  two  at  the  eastern  end  of  the  palace  in  the 
city  of  Alexandria.  There  are  also  ancient  porphyry  busts  of 
several  of  the  Roman  Emperors  still  preserved  in  the  palace  of 
the  Thuilleries  at  Paris.  On  the  porphyry  pillars  of  Egypt,  and 
on  the  methods  which  it  has  been  supposed  the  ancients  adopted 

I  in  cutting  and  polishing  porph\-ry,  the  following  works  may  be 
consulted.   Dr.  Lister  in  the  Phil.  Trans.  No.  203.   Dr.  Robert 

1       Huntington  in  the  fAif.  rrim.  No.  I(il,  pnge624>orBaddam'a 

/  Memoiri  of  the  Hoifal  Society,  vol.  ii  page  2^6.  Birch's  Hii- 
torj  of  the  Royal  Society,  vol.  i.  page  23^,  and  vol.  ii.  page  73. 
Boyle's  U'orh  ahridifed  by  Shaw,  vol.  i.  page  IL 1 .   Da  CosU'S 

'      Natural  Hulory  of  FouiU,  page  285. 

50.  Art  of  forming  copper. — Page  481,  line  20. 

K{  know  that  the  Anglo-Saxons  had  acquired  thr  art 
2  «  2 


(n2 


ADDITIONAL   NOTES, 


of  working  in  brass  and  copper,  from  an  incident  which  lln"  his- 
torian has  roiated  of  King  Edgar.  It  was  the  custom  in  hi» 
time,  ihal  a  whole  company  drank  out  of  a  single  vessel,  which 
WM  handed  from  one  to  another.  "  To  prevent  quarrrb,  Kii^ 
Edgar,"  he  says,  "  commanded  the  drinking- vesseb  to  be  maile 
with  knobs  of  bra.ss  on  the  inside  at  certain  distances  from  cadt 
other;  and  decreed  that  no  person,  under  a  certain  penalty, 
should  either  drink  himself,  or  compel  another  to  drink,  at  oet 
draught,  more  than  from  one  of  these  knobs  to  another. 
h^illiatn  of  MalmeibuTij,  book  ii.  page  31, 

When  the  ancients  employed  copper  for  making  weapons  4; 
war,  they  hardened  the  metal  by  an  admixture  of  tin,  Maif 
such  instruments  are  still  preserved  in  the  cabinets  of  the  cu- 
rious.    See  Nicholson's  quarto  Journal,  vol.  i,  page  468. 

51.  Ifar-cJioriof.— Page  4S*.>,  line  3. 
The  Britons  and  ancient  Greeks  and  Romans  were  not  ll 
only  people  who  employed  chariots  in  the  field  of  battle.  A|^ 
plan,  an  historian  eminent  for  fidelity,  relates  that  the  army  d 
Ptolemy  Philadelphus  king  of  Egypt  consisted  of  200,000  fao^ 
40,000  horse,  300  elephants,  and  2000  armed  chariots.  S« 
Dr.  Gillies's  Hislon/  of  the  World,  2  vols.  4lo,  London  Ib08 


In  the 
chariots 


■  Diodorus  Sicutus,  our  ancestors  in  Briuun 
I  the  field  of  battle.     See  his  Hatojy,  chap.  ' 


235.     Mr.  Pegge,  however,  asserts  that  these  were  diffe^eIl^|| 
constructed  from  those  used  at  Troy.     See  "  Observation*  of^ 
the  Chariots,  &c.  of  the  ancient  Britons,"  Jrcheeologia,  toI.  H 
article  24, 

52.  Imperiiil/oundrics. — Page  482,  line  22. 
Uliat  has  been  said  of  the  foundries  which  were  established 
in  this  country  by  the  Romans  for  making  iron  might  be  coo- 
firmed,  if  there  were  any  doubt  of  the  fact,  by  a  circumstance 
which  occurred  about  forty  years  ago  in  Wales,  near  the  towi 
of  Brecknock.     In  October  1783,  as  some  labourers  were  fdl-* 
ing  a  tree,  the  roots  of  which  tore  up  the  earth,  some  small  p)'i 
lars  were  presented  to  view.     It  afterwards  appeared  that  ihat^ 
belonged  to  a  Roman  work  consisting  of  three  baths  [  one  boC^ 
the  two  others  cold.    The  state  of  this  curious  relic  is  desrriW] 
by  Mr,  Hay,  who  has  also  given  a  good  engraving  of  iL 
one  of  the  passages  lo  the  baths  was  found  a  bar  of  matii 
iron,  four  feel  long.     See  Arckeeologia,  vol.  vii.     At  this  pt 
few  persons  in  Europe  were  acquainted  with  a  method  of  makii 
cut  ling- instruments  either  of  iron  or  steel ;  for  it  is  related  tl 
the  inhabitants  of  the  northern  countries  of  Europe  beliei 


ADDITIONAI.  N0TE8.  (113 

thnt  Bwords  were  mode  by  I'eititiD  py^ies  who  were  roncealed 
in  tlie  mountainli.     Bcrgraan's  Physical  Euayt,  vol.  iii.  p.  89. 

53.   Fint  made  in  London. — Page  435,  line  7. 


art  of  making  urmour  and  offensive  weapons  of  slee),  it  seems 
extraordinary  that  bo  long  a  period  should  have  intervened  be- 
Tore  they  acquired  the  metliod  of  mikking  the  most  useful  im- 
plemeots  of  commoa  life  in  that  metal.  It  has  already  been 
nhown  that  table-kniveii  were  not  fabricated  in  London  until 
the  year  1563  ;  and  it  is  related  by  Slowe,  that  needles  were 
not  sold  in  Cheapside  until  the  reign  of  Queen  Mary,  and  then 
they  were  made  by  a  Spanish  Negro,  who  refused  to  discover 
the  secret  of  his  art. 

Even  the  pin  was  not  known  in  England  till  towards  the 
middle,  or  latter  end,  of  the  reign  of  Henry  VIII,  j  the  ladies 
until  then  using  ribbons,  loops,  skewers  made  of  wood,  of  brass, 
silver,  or  gold.  At  first  the  pin  was  so  ill  made,  that  in  the 
S4th  year  of  the  king,  parliament  enacted  that  none  should  be 
sold  unless  they  be  "  double-headed,  and  have  the  headdes  sou- 
dered  fostc  to  the  shimke  of  the  pynne,"  &c.  Hut  this  inter- 
ference hod  such  an  influence  on  the  manufacture,  that  the  pub- 
lic could  obtain  no  supply  until  the  obnoxious  act  was  repealed. 
On  referring  to  the  Statute  Book,  I  find  that  the  aci  of  repeal, 
which  passed  in  the  3'th  year  of  the  sam^  reign,  contains  the 
following  clauses,  which  tend  to  show  how  cautious  the  Legis- 
lature ought  to  be  not  to  interfere  with  any  manufactory  which 
they  do  not  perfectly  understand.  The  act  of  repeal  having  re- 
cited the  former  act,  it  then  goes  on  to  say,  "  At  which  tyrae 
the  pynners  playnly  promised  to  serve  the  kyngen  liege  people 
wel  and  sufficiently,  and  at  a  reasonable  price.  And  fur  as 
much  as  sens  the  makying  of  the  saide  act  there  hath  ben  scar- 
citee  of  pynnes  within  this  reabne  that  the  kynges  liege  people 
have  not  ben  wel  nor  competetly  served  of  such  pynnes  nor  ar 
like  to  be  served  nor  the  pynners  of  this  retdm  (us  it  doelh  nowe 
manifestly  appere)  be  hnble  to  serve  the  people  of  this  realme 
accordyng  to  their  smed  promise.  In  considerocion  whereof  it 
maie  please  the  kyng,  &c.  that  it  maie  be  adjudged  and  demed 
from  hensforthe  ^uatrate  and  nihilated  and  to  M  repealed  for 
ever."     Slal.  Henrid  Octavi  xxxvii.  c^.  13. 

54.  Damascus  aoordi. — Page  523,  line  8, 

The  sabres  of  Damascus  have  ^ven  rise  to  a  curious  art  in 

ibc  working  uf  irun  and  steel  called  Damutktmmg,  which  cun- 


ADDITIONAL    NOTES. 

slsts  in  diaking  Intisiuns  therein  and  filling  those  up  with  goW 
or  silver  wire.  Tlits  pracesH  is  employed  chiefly  in  enritibg 
sword  blades,  and  the  locks  of  pistols.  Dr.  Rces  in  the  Cyclo- 
ptcdia  vol.  xi.  has  described  the  method  by  which  this  artificial 
damasking  is  eflecterl,  and  which  1  think  wortli  transcribing. 

"  The  name  which  this  art  bears,  shows  the  place  of  its  ori- 
gin, or  at  least  the  piece  where  it  has  been  practised  in  the 
greatest  perfection,  viz,  the  city  of  Damascus  in  Syria  ;  though 
M.  Felibien  attributes  the  perfection  uf  the  art  to  hn  coantry- 
man  Cursinet,  who  wrought  under  the  reign  of  King  Henry  IV. 

Damaskeening  is  partly  mosaic  work,  partly  engraving,  and 
partly  carving:  as  mos^c  work,  it  consists  of  pieces  inlaid  ;  as 
engraving,  tbemetal  is  indented  or  cut  in  creux;  and  as  carving, 
gold  and  silver  are  wrought  therein  in  relievo. 

There  are  two  ways  of  damaskeening ;  in  the  first,  which  is 
the  most  beautiful,  the  artbts  cut  into  the  metal  with  a  gnivw 
and  other  tools  proper  for  engraving  on  steel,  and  afterwanl* 
fill  up  the  incisions  or  notches  with  a  pretty  thick  silver  or 
gold  wire,  in  the  other,  which  is  only  superficial,  they  content 
themselves  to  make  hatches,  or  strokes  across  the  iron,  &c 
vrith  a  cutting  knife,  such  as  is  used  in  making  small  Sle».  As 
to  the  fiist,  it  is  necessary  the  gravinp  or  incisions  be  made 
in  the  dove-tail  form,  that  the  gold  or  silver  wire,  which  is  tliniat 
forcibly  into  ihem,  may  adhere  the  more  strongly.  As  to  the 
second,  which  is  the  more  usual,  the  method  '»  this :  Having 
heated  the  steel  till  it  changes  to  a  violet  or  blue  cvlour,  they 
hatch  it  over  and  across  with  the  knife,  then  draw  the  ensign 
or  ornament,  intended,  on  this  hatching,  with  a  fine  brass  point 
or  bodkin.  This  done,  they  take  fine  gold  wire,  and  conduct- 
ing or  chnsin^  it  according  to  the  figures  already  designed,  they 
sink  it  carefiUly  into  the  hatches  of  the  metal  with  a  copper 
tool."  Some  of  this  work  is  very  durable  and  extremely  bean* 
tiful.     See  pages  523 — 32i),  and  page  543  of  this  volume. 

S5.  Metallic  iolftn.— Page  52fi,  line  2. 

TTie  following  Tables  having  been  constructed  from  actus) 
experiment,  for  the  purpo.fe  of  enabling  the  working  cutler  to 
prepare  various  kinds  of  metallic  batlis,  1  am  desirotis  of  pre^ 
cing  them  with  a  few  words  explanatory  of  the  methods  I  par- 
sued  in  making  the  experiments. 

In  order  to  conduct  these  experimenls  with  as  much  accuracy 
as  possible,  I  procured  two  bright  iron  ladtes  capable  of  holding 
four  ounces  of  water  each.  In  one  of  these  the  mixed  metids 
were  melted ;  and  when  the  alloy  was  completely  fused  and 


ADDITIONAL   NOTES.  615 

thoroughly  mixed,  it  was  poured  into  llie  other  laitle  *,  and  k 
thermometer  gradunted  to  620"  immersed  in  it.  As  the  melted 
compound  cooled,  the  thermometer  progressively  fell :  this  mo- 
lion  wiu  can-fully  waUhed,  and  at  the  moment  when  the  mer- 
cury censed  to  sink,  the  degree  at  wliich  tlie  instrument  rtood 
wa^  Hcctimtely  noted  down,  ns  the  point  of  fusion  of  that  par- 
ticular alloy.  Tlie  same  plan  was  followed  in  every  instance  : 
nnd  there  was  the  lens  difficulty  in  doing  this,  because  it  usually 
happened  that  the  mercury  sunk  with  great  regularity  white  the 
melted  metal  was  in  the  act  of  cooling  and  still  in  a  fluid  state, 
until  it  stopped  altogether  j  and  at  ttiat  moment  the  mercury 
was  observed  to  rise  one  degree +,  TTiia  evidently  noted  a 
change  in  the  state  of  the  metal,  and  appeared  to  me  to  be  the 
exact  point  which  oui^ht  to  be  noted  as  the  degree  of  tempera- 
ture at  which  complete  fusion  ceases  and  the  state  of  solidity 
commences. 

The  Table  No,  1.  was  constructed  from  the  results  of  the  first 
■et  of  experiments  with  tin,  lead,  and  bismuth  ;  tho^e  No  U. 
and  111,  show  the  melting  points  of  several  compocnds  made 
with  tin  and  lead  only.  These  lu-st  alloys  will  prove  more  use- 
ful to  the  working  cutler,  because  such  baths  can  be  constructed 
cheaper  than  those  which  contain  bismuth,  and  the  melting 
pointt  are  generally  higher. 


Table,  No.  I. 

A  npTc  Table  of  the  different  Temperatures  at  whtcA  the 
JvUoteing  Metallic  Compounds,  made  with  Bismuth, 
Lead,  and  Tin,  respectively  melt. 


6  bismuth,  h  lead,  and  3  tin  melt  a: 

S  bismuth,  G  lead,  3  tin 

S  bismuth,  8  lead,  3  tin 

8  bismuth,  S  lead,  A  tin 

8  bismuth,  S  lead,  6  tin 


*  AlUiough  this  iidic  wu  not  put  ana  lh»  ckucoal  Arc  like  llie  other 
in  which  ihe  umuIi  wi3c  mclud.  «srf  wu  lakcn  to  keq>  it  hc4,  itut  il 
might  not  diill  the  Buid  silo;  too  mucb  whin  il  wh  poarnl  into  it. 

t  Th«  bulb  of  the  thCTmoinM«r  mi  dwi^  put  into  the  r*nlrt  ot  tb« 
tncllcd  niBivs  oxl  <n  ""  cum  wu  allawrd  to  go  to  tht  bottom  uf  it  »  ■•  to 
MHKh  Uw  iRjfl  ladle,  leit  tliis  ihouU  not  cool  in  ili*  tuat  gndition  u  tb* 
laid  melml. 


616  ADDITIONAL   NOT£8« 


Pnrta  of  metal  Parts  of  Parts.  Degree  oT 

by  weight. 


8  bismuth,  8  lead,  and  8  tin  melt  at  254 

8  bismuth,  10  lead,  8  tin  266 

8  bismuth,  12  lead,  8  tin  270 

8  bismuth,  16  lead,  8  tin  300 

8  bismuth,  16  lead,  10  tin  304 

8  bismuth,  16  lead,  12  tin  294 

8  bismuth,  16  lead,  14  tin  290 

8  bismuth,  16  lead,  16  tin  292 

8  bismuth,  16  lead,  18  tin  298 

8  bismuth,  16  lead,  20  tin  304 

8  bismuth,  16  lead,  22  tin  312 

8ii.bismuth,  16  lead,  24  tin  316 

^  bismuth,  18  lead,  24  tin  312 

8  bismuth,  20  lead,  24  tin  310 

8  bismuth,  22  lead,  24  tin  308 

8  bismuth,  24  lead«  24  tin  310 

8  bismuth,  26  lead,  24  tin  320 

8  bismuth,  28  lead,  24  tin  330 

8  bismuth,  30  lead,  24  tin  342 

8  bismutli,  32  lead,  24  tin  352 

8  bismuth,  32  lead,  26  tin  348 

8  bismuth,  32  lead,  28  tin  332 

8  bismuth,  32  lead,  30  tin  328 

8  bismuth,  32  lead,  32  tin  320 

8  bismuth,  32  lead,  34  tin  318 

8  bismuth,  32  lead,  36  tin  320 

8  bismuth,  32  lead,  38  tin  322 

8  bismuth,  32  lead,  40  tin  324 

Table,  No.  II. 

A  7iew  Table  of  the  different  Temperatures  at  which  ^- 

jyeral  Metallic  Compounds  made  xvith   Tin  and  Lead 
only,  respect itfely  melt. 


se^ 


Parts. 

PartB.                                Teinp. 

4  tin 

and 

4  lead  melt  at     372® 

5  tin 

4  lead                  352 

6  tin 

4  lead                  336 

7  tin 

4  lead                  338 

8  tin 

4  lead                  340 

9  tin 

4  lead                   544 

10  tin 

•1  lead                   348 

ADDITIONAL   NOTES. 


617 


Pai-U. 

11  tin 

12  tin 

13  tin 

14  tin 

15  tin 

16  tin 

17  tin 

18  tin 

19  tin 

20  tin 
22  tin 
24  tin 

4  lead 

5  lead 

6  lead 

7  lead 

8  lead 

9  lead 

10  lead 

11  lead 

12  lead 

13  lead 

14  lead 

15  lead 

16  lead 

17  lead 

18  lead 

19  lead 

20  lead 

21  lead 

22  lead 

23  lead 

24  lead 

25  lead 

26  lead 

27  lead 

28  lead 

29  lead 

30  lead 
32  lead 
34  lead 
36  lead 
38  lead 


ParU. 

and       4  lead   melt  at 
4  lead 


4 
4 
4 
4 
4 
4 
4 
4 
4 
4 

4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 


lead 
lead 
lead 
lead 
lead 
lead 
lead 
lead 
lead 
lead 


n 
n 
n 
n 
n 
n 
n 
n 
n 


t 
tin 


m 
n 
in 
in 
in 
n 
n 
m 
in 
in 
n 
in 
in 
in 
in 
m 
in 
in 
m 
n 
m 


Temii. 

3520 

356 

360 

362 

364 

367 

370 

372 

375 

378 

380 

382 

372 

390 

412 

420 

442 

460 

470 

476 

482 

486 

490 

494 

498 

502 

505 

509 

512 

515 

517 

518 

519 

520 

523 

525 

527 

529 

530 

532 

535 

538 

540 


S18  ADDITIONAL  WOTXS. 


40  lead       and 

42  lead 

44  lead 

46  lead 

48  lead 

50  lead 

52  lead 

54  lead 

56  lead 

58  lead 

60  lead 

62  lead 

64  lead 

66  lead 

68  lead 

70  lead 

100  lead 


4  tin    meh  at 

5A2? 

4  tin 

544 

4  tin 

546 

4  tin 

548 

4  tin 

550 

4  tin 

551 

4  tin 

552 

4  tin 

554 

4  tin 

555 

4  tin 

556 

4  tin 

557 

4  tin 

557 

4  tin 

557 

4  tin 

557 

4  tin 

557 

4  tin 

557 

4  tin 

558 

taat 

612 

The  following  Table,  marked  No.  III.,  consists  chiefly  of  a 
selection  from  the  aforesaid  alloys,  of  such  mixtures  as  appear 
to  me  to  be  suitable  for  certain  purposes  of  the  working  cutler. 
Such  manu&cturers,  therefore,  will  need  only  to  look  in  the 
Table  for  the  name  of  the  edge  tool  which  they  have  occasion 
to  temper,  and  opposite  thereto  they  will  find  the  proportion 
of  each  metal  that  Ls  necessary  to  form  a  bath  for  tempering 
that  particular  instrument.  When  the  alloy  is  in  u.se,  a  quan- 
tity of  tallow  or  grease  ought  to  be  put  with  it  -,  as  this  will 
swim  upon  the  melted  mass,  and  prevent  the  oxidation  of  the 
metals.  When  the  process  of  tempering  is  finished,  the  me- 
tallic alloy  should  always  be  marked  with  the  number  that  is 
attaclied  to  it  in  the  Table,  as  this  will  prevent  mistakes  in  the 
selection  of  the  baths  for  fiiture  operations. 


r 


auditionai,  notes 

No,  III. 


A  nro}  TuMe  of  the  Composition  of  MetaUic  Batlis  for  the 
Use  of  fPorking  Cutlers. 


1 

of  llw  Bath. 

T,m,*r. 

Lancets,  in  a  Bath  composed  of 

7    lead  4  tin 

420" 

2 

Olher  Nurgical  inatnimenta 

7*  lend  4  tin 

430 

3 

Razors,  &c 

8    lead  4  tin 

442 

4 

of  surgery     

8^  lead  4  tin 

4.10 

5 

Lai^r  penknives,  scalpels,  &c. 

10    lead  4  tin 

470 

fi 

SciRsars,   uheani,  gnrdeii   hoea. 

told  chisels,  Ac 

14   lead  4  tin 

490 

7 

A\ta,  firmer  chiselx,  plane- ituns. 

pocket -knives,  &c 

19    lead  4  tin 

509 

H 

Table-knives,  laige  shears,  fire. 

30    lead  4  tin 

5;io 

» 

Swords,  wBlch-springs,  lie.     . . 
Large  springs,  dag^rs,  augers. 

48    lead  J  tin 

550 

1U 

small  fine  saws,  &c 

50    lead  2  tin 

558 

11 

Pit-jinws,  hnnd-enm,  and  some 

particular  springs     

Boiling  lins*  oil 

600 

12 

Arliclea  which  require  to  be  still 

Melting  lead 

612 

In  making  the  experiments  which  laid  the  foundation  of  the 
Tables  No.  Tl.  and  III.  several  curious  anomalies  were  observed 
which  deserre  particular  notice.  Tin  itself  tnelto  at  the  tem- 
perature of  440"  of  Fahrenheit,  pure  lead  at  612°.  but  a  mix- 
ture ot'  equal  weights  of  these  two  metals,  as  will  appear  by  the 
inspection  of  the  Table  No.  11.,  became  fusible  at  372^;  with 
the  addition  of  one  part  more  of  tin  the  compound  melts  at  352", 
and  another  part  of  tin  added  to  the  former  mixture  renden  the 
whole  fusible  at  S'Sti" ;  but  after  this,  ever}- addition  of  tin, 
though  this  i.s  the  mote  fu»>ible  metal  of  the  two,  renklen  the 
compound  still  more  and  more  infusible. 

In  entering  upon  the  second  course  of  experiments  for  Ta- 
ble II.,  I  began,  as  before,  with  four  parts  of  lead  and  four  of  tin  ; 
but  instead  of  increasing  the  tin  as  in  the  first  series,  I  suffered 
that  to  remain  the  same,  and  made  an  addition  of  lead  for  each 


620*  AJDDITIONAL   NOTES. 

new  experiment ;  and  this,  as  might  have  been  expected,  had 
the  effect  of  increasing  the  degree  of  temperature  of  the  melt- 
ing point  at  every  fresh  iMifUin  of  the  lead,  until  I  attained 
the  temperature  of  557*«  when  the  further  additions  of  lead 
made  no  alteratioa  in  the  fusBnlity  of  the  compound. 

Having  endeamured  in  vain  to  account  for  this  very  singular 
anomaly,  I  at  last  imagined  that  owing  to  the  large  quantity  of 
lead,  compared  with  tin,  which  was  exposed  to  the  fire,  at  every 
melting,  as  much  lead  might  each  time  be  converted  to  an  oxide 
as  was  equal  to  the  new  lead  perpetually  added,  and  that  this 
might  occasion  the  alloy  to  be  more  fusible  than  was  expected. 
Therefore,  to  put  this  suspicion  to  the  test,  I  emptied  the  ladle 
entirely,  and  took  fresh  portions  of  both  the  metals  in  the  pro- 
portions of  70  of  the  one  and  4  of  the  other.  Here  I  was  sur- 
prised to  find  that  the  fusing  point  was  still  55  7^  I  then  melted 
]  00  parts  of  lead  with  4  of  tin  3  but  in  this  case  the  fusing  point 
appeared  to  be  rather  under  558**,  whereas  on  leaving  out  the 
4  parts  of  tin  and  immersing  the  thermometer  in  lead  only,  the 
mass  always  began  to  congeal  when  the  mercury  in  the  instru- 
ment had  sunk  to  6 12^ 

Before  1  close  this  subject,  I  wish  to  remark  that  seveial . 
writers  have  differed  very  much  in  their  accounts  of  the  point 
at  which  lead  becomes  fusiUe.  Su:  Isaac  Newton  states  it  to 
be  540^  Dr.  Lewis  near  540^,  Cloud*  548^^,  Morveau  590*, 
Irvine  and  Guyton  594^,  Dalton  610<>,  and  Crichton  612^. 
This  disparity  has  been  occasioned,  as  I  apprehend,  by  some  of 
these  eminent  experimentalists  having  employed  lead  of  an  im- 
pure quality ;  because  I  found  that  a  very  minute  portion  of  tin 
increases  its  fusibility  in  a  surprising  degree. 

This  effect  of  tin  upon  lead  I  discovert  very  soon  after  I  be- 
gan these  experiments ;  and  therefore,  to  ensure  the  purity  of 
Uie  lead,  I  procured  some  for  myself  by  the  reduction  of  li* 
tharge ;  and  I  can  venture  to  state  with  confidence  that  the 
fusing  point  of  lead  is  612^,  as  that  which  I  obtained  in  the  way 
above  mentioned  would  not  melt  until  it  had  acquired  that  tem- 
perature. 


*  Memoir  by  Mr.  Joseph  Cloud,  assayer  of  the  Mint  in  the  United 
States,  entitled  **  An  Attempt  to  ascertain  the  fusing  Temperature  of  Me^ 
tals,**  in  the  Trantaetwru  of  the  American  Pkiotophkal  Sockty,  New  Series, 
vol.  i.  page  169. 


A  TABLE 


or   THE 


EQUIVALENT   NUMBERS 


OF 


VARIOUS  SUBSTANCES, 


MOST   OF  WHICH   ARE   MENTIONED    IN   THESE   E86AYS. 


BUBSTANCEI. 


Add  acetic  

arsenic    

arsenious 

benzoic    , 

boletic 

boracic 

camphoric  .... 

carbonic 

chloric 

chloriodic  . . . , 
chlorocarbonic 
chlorocyanic  . 

chromic  

citric  (dry)  . . . 


EquiTalenI 
Nnmber. 


48 

G6.5 

59 

112 

? 

20 
? 

207 

71 
151.25 

46.7 
57.9 
43.5 
55.8 


CoMPOiilTION. 


? 

Arten.  44  -f  oxy.  22.5 
Arsen.  44  +  oxy.  15 


Boron  5  +  oxy.  15 

Carb.  57  -h  oxy.  15 
Chlor.  33.5  -h  oxy.  37.5 
lod.  117.75 +  chl.  33.5 
Chlor.  33.5  4  carb.  oxide  13.2 
Chlor.  33.5  +  cyan.  24.4 

Chr.  28.5  -f  o«y-  1^ 

Carb.  22.8  +  oxy.  30  -f  hyd.  3 


622 


AN    ALPHABETICAL   TABLE 


Substances. 


Acid  citric  crystallized  .... 

'         colambic 

ferroc]ranir 

•^—  fluoboric 

■         fluoric 

—  gallic    

—  bydriodic 

—  bydrocyanic    

•^—  bydropbospborous  . . 
»-»  bypopbotpborous  .... 
-^—  byposulpburic    

—  byposulpburous     .... 

iodic 

lactic    

—  malic    • 

^—^  meconic 

molybdic 

molybdous 

■         muriatic 

nitric^  dry 

— ,  liquid(sp.gr.1 .60) 

— -  nitrous 

oxalic  

crystal*,  4  waters 


EqoiTalfvt 
Namber. 


72.8 
116.5 

? 
20.? 
16? 
69.7 
1 18.75 
26.4 
46.5 
14.76  ? 
33.76  ? 
22.6? 
166.26 

? 
66? 
21? 
66.5 
59 
346 
50.6 
67.6 
43 

36.6? 
69.5 


Composition. 


Cit  ac.  56.8  +  water  17 
Col.  139  -f  oiry.  7.5 

Fluor.  16  +  boron  5. 

Fluor.  16  +  byd.  1 

Carb.  34.2  +  ozy.  225  +  byd.a 

lod.  117.75 -f  byd.  1 

Carb.  11.4  +  nit.  13  +  hyd.  1 

Pbos.  ac.  37  +  water  8.S 

? 
Sulpb.  16  +  oxy.  I8.75 1 
Sulpb.  16  +  oxy.  7^  ? 
lod.  117.76  +  oxy.  37.5 

Composition  unknowou 

Moly.  44  -f  oxy.  22.5 
Moly.  44  +  ox.  15 
Chlor.  33.6  +  hyd.  1 
Nitrog.  13  -f  oxy.  37.5 
Nitr.  acid  50.6  -f-  water  17 
Nitrog.  13  +  oxyg.  30 

Oxal.  acid  36.5  4-  water  34 


OF   CHEMICAL   KAUIVALENTS. 


623 


Substances. 


Acid  ozychloric  

oxyodic  

—  phoflphoric 

—  phosphorous 

•^—  prussic    

•^—  saccholactic 

selenic 

sorhic J 

suheric   

succinic 

sulphuric  (dry) 

•^— liquid  (sp.gr.  1.86) 

sulphurous 

tartaric    

tungstic 

uric 

zumic 

Alomium 

Alum  (dry)  

———crystallized  (26  waters) 

Alumina    

•^—acetate 

■        sulphate 

Ammonia 


Equi  Talent 
Number. 


86.0 
166.26 
26 
18.6 
26.4 
? 

62.6 

same  as 
malic. 

? 

47.3 

37.6 

46 

30. 

62.6 
112.6 

33.? 
? 

16.6 
243 
420 

24 

72 

61.6 

16 


Composition, 


Chlo.  33.6  +  oxyg.  62.6 
Iodine  11775  -f  oxy.  37^60 
Phosp.  11.  -f  oxy.  16 
Phosp.  11.  -f  oxy.  7-6 
Carb.  11.4  +  nitr.  13.  +  hyd.  1 
Composition  unknovm. 
Selenium  37.6  +  oxy.  16 

Composition  unknown. 

Carbon  22  8  +  oxy.  22.6  +  hyd.  3 
Sulp.  15  -f  22.6  oxy. 
Sulp.  ac  37.6  -f  water  8.6 
Sulph.  16  -f  oxyg.  16 

? 
Tung.  90  -f  oxy.  22.6 

Composition  unknown. 


Sulph.  alumin.  123+biaulp.potl80 
Alum,  dry  243  -f  water  187 
Alumium  16.6  -|-  oxyg.  7*6 
Alumina  24  -f-  ac.  acid  48 
Ox.  alum.  24  +  sulp.  add  37.6 
Nitrog.  13  +  hyd.  3 


AN    ALPHARETICAL   TABLE 


SUBSTINCSI. 

K<|iil<>l«l 

C0»li.0.1T.ON. 

64 

Amm.  16  +  >cel.  mc.  4t< 

82.6 
126 

Adud.  16  +  ben.  ac.  112 

36.7 

AnuQ.  16  +  carb.  kc  20-7 

67-4 

Amm.  16+CMb.  »d<l4l.4 

. chlorMa 

87 

Amm.  l6  +  cUor.acid71 

69.5 

Amm.  16  +  chrom.  acid  43.6 

71J 
50.5 

Amm.  16  +  citr.  acid  56.8 

^^^^ 

MBUte 

51.5 

Amm.  16.  +  oxaL  ac.  35.5 

pWphaW   

42 

Amm.  16  +  phot.  ac.  26 

34.5 

Amm.  16  +  p|.<».  ac.  18.5 

iuccinftte 

63J 
fi3.6 

.ulphate 

Awm.  16  +  «ulp.  ac.  37.5 

• sulpbite  

76 

Amm.  16  +  aulp-  ac.  60 

78.5 

Antimony 

4S 

iodide  

162.7 

Anlim.  45  +  iod.  117.6 

62  5 

Antim.  45  +  oiy.  7-5 
Antim.  45  +  oiy.  15 

oxide  2iid 

60 

»ulph«te 

90 

Oxid.  antim.  52.5  +  .u|p.  ^  37J 

sulpburrt 

60 

Antim.  45  +  sulp.  IS 

OF   CHEMICAL    EttUIVALENTS. 


625 


Substances. 

AntiiiioDy,  oxalate  of 
phosphate  .... 
phosphuret .... 


tartrate 


Anenic 


acid 


chloride 


muriate 


white  oxide. 


sulphuret 


AioCe 


Barium 


chloride 


iodide 


oxide 


•■*—  peroxide  . . 

•^—  phosphuret 

sulphuret  . . 

Barytes 


acetate    . 

arseniate 

arsenite 

benzoate 
VOL.  II. 


Equivalent 
Number. 


88 

78.5 

66 
115 

44 

66.5 
ill 
128 

59.0 

59 

13 

65.0 
98.6 

182.7 

72.5 

80.0 

76 

80 

72.5 
120.5 
139.0 
131.5 
184.5 

2s» 


Composition. 


Ox.  ant.  52.5  +  ox.  ac.  35.5 
Ox.  ant.  52.5  +  ph.  ac.  26 
Ant.  45  +  phosp.  11 
Ox.  ant.  52.5  -|-  tar.  ac.  62.5 

Ars.  44  +  oxyg.  22.5 
Ars.  44  -f  chlorine  67 
Oxy.  ars.  59  +  mur.  ac.  69 
Ars.  44  +  oxyg.  15 
Ars.  44  +  sulphur  15 


Bar.  65  -f-  chlorine  33.5 
Barium  65  +  iodine  1 1 7*7 
Bar.  65  -|-  oxyg.  7-5 
Bar.  63  -f  oxyg.  15.0 
Bar.  65  -|-  phosp.  1 1 
Bar.  65  +  sulphur  15 
Bar.  65  -|-  oxyg.  7-5 
Bar.  72.5  +  ac.  ac.  48 
Bary.  72  5  -f  ar4.  acid  66.6 
Bary.  72.5  +  arsen.  ac.  59 
Bar.  72.5  +  benz.  ac.  112 


AN    ALFHABBTICAL   TABLB 


StIBSTAMCES. 

X'^r 

BwTtM,  borate  of 

92.5 

Bar.  72.5  +  bor.  «c  20 

—  CBmphoiate    

I 

•^— carbonntf    ...  

935 

Barries  72.5  +  caA.  ae.  2a7 

tUorate  

I4S.5 

Bar.  72.5  +  cblo.  «c  71 

chromate 

116 

Bwy.  72.5  +  chr.  Bc.  416 

Bar.  72.5  +  dt.  ac.  S&8 
Bary.  72.6  +  fluor.«id  16 

Siiate  

88.5 

—  g^^ 

lasji 

Bar.  72.5  +  gal.  ac  59.? 

bydnile    

BI.Q 

Bar.  72.5  +  water  8.6 

crjstailiied     „ 

»2.6 

Bar.  72.5  +  water  170 

191JJ 

Bar.  72.6  + hyd.BcIia; 

227.76 

Bar.  72.60  +  iod.  ac.  1S5JS 

Budrte 

138.5 

Bar.  72.5  +  tuaL  m.  66 

139 

Bar.  72.6  +  mol.  ac.  66.6 

in? 

Bar.  72.5  +  mur,  ac  3i£ 

123 

Bar.  72.6  +  nit.  ac.  50.5 

crystalliied  .... 

MO 

Nilr.Bar.  123  + water  17 

108 

Bar.  72.6 +  oi.ae.  365 

phosphate  

98.6 

Bar.  72.5  +  phos.  ac.  26 

91 

Bary.  72.5  +  phos.  ac.  145 

phMphur^l 

?6 

125 

Bary.  725  +  ael.  add 52.5 

} 
119,8 

Bar.  72.5  +  ,uc.  ac.  4/3 

OF  CHEMICAL    EQUIVALENTS. 


627 


Substances. 


Barytesy  sulphate  of 

— —  salpbite  

^-»  solphuret    

— -  tartrate    

^    tuQgstate 

—— orate    

— —  zomate    

Bitmuth    

acetate 

arseniate     

chloride 

dtrate 

iodide  

nitrate 

oxalate 

oxide    

sulphate 

solphuret.  .   

tartrate    

Borax    

Boron 

Caldum 

— •  chloride  


Rqtti  Talent 
NttmlMT. 


110 
102.5 

80 

135 

185 

105.5 

? 

66.5 
122 
140.5 
100 
129.8 
184.2 
124.5 
129.5 

74 
111.5 

81.5 
136.5 

49.5 


Composition. 


Bar.  72.5  +  sulp.  ac.  37.5 
Bar.  72.5  +  sulp.  ac.  30 
Barium  65  -{-  sulphur  15 
Bar.  72.5  +  tar.  acid  62.5 
Bar.  72.5  +  tung.  acid  1 12.5 
Bar.  72.5  +  ur.  ac.  33 


Ox.  bM.  74  +  ac.  ac.  48 
Ox.  bi».  74  +  ar.  ac.  66.5 
Bismuth  66.5  -|-  chlorine  33.5 
Ox.  bism.  74  +  citr.  ac.  hBS 
Bism.  66.5  -j-  iod.  117.7 
Ox.  bism.  74  +  nitr.  acid  60.5 
Ox.  bis.  74  +  oxal.  ac.  35.5 
Bis.  66.5  -h  oxy.  7.5 
Ox.  bis.  74  +  sulp.  acid  37.5 
Bism.  66.5  -{-  sulphor  15 
Ox.  bis.  74.  +  tar.  add  62.5 
Soda  29.5  +  bor.  add  SO 


19 

52.5       I  Caldum  19  +  chlor.  33.5 

2s2 


628 


AM   ALPHABETICAL  TABLE 


Substances. 

BqniTalent 
Nttiulm'. 

CuMpoaiTioff.  ' 

Calcium^  fluoride  of  

34 

Calc.  19  +  fluorine  15 

iodide 

136.7 

Calc.  19  +  iodine  1177 

—  oxide   

26.6 

Calc.  19  -f  oxyg.  J^S 

30 

Cal.l9-f  phos.  11 
Cal.  19  -h  sulp.  15 

sulphuret    

34 

Calomel    

223.5 

Mercury  190  +  chhrnnedS^ 

Carbon 

6.7 

hydrochloride    

46.9 

Chlo.  33.5  -f  def.  gms  1^4 

-— —  perchloride 

111.9 

Carb.  11.4  + chlor.  100.5 

protodiloride 

39.2 

Carb.  5.7  +  chlorine  333 

oxide    

13.2 

Carb.  5.7  -h  oxy.  7-6 

16.7 

Carb.  6.7  -f  phosphomt  11 

sulphuret    

36.7 

Carb.  6.7  -h  sulp.  30 

Carburet  of  mtrogen 

24.4 

Carb.  11.4  +  nitrog,  13 

Carburetted  hydrogen  .... 

6.7 

Carb.  6.7  -h  hyd.  1 

Chloride  of  nitrogen 

147 

Nitr.  13.  -f  chl.  134 

Chlorine    

33.5 

Chloric  ether  

46.9 

Chlor.  33.6  -}-  olef.  gas  13.4 

71 

Chlor.  33.6  +  oxyg.  37.5 

Chromium    

28.6 

Ist  oxide    

36 

Chrome  28.6  -f  oxyg.  73 

2nd  oxid  (acid) 

43.6 

Chrome  28.6  -f  oxyg.  15 

Citrate  of  ammonia 

71.8 

Citr.  ac.  66.8  -f-  amm.  16 

barytes 

128.3 

Citr.  ac  66.8  -f  barytes  723 

OF   CHEMICAL    ESkUIVALENTS. 


629 


Substances. 


CitrjLte  of  bbmuth 

cobalt 

copper 

iron 

lead 

lime 

magnesia    . . 

manganese.. 

mercury  .... 

nickel 

potash 

silver   

soda 

strontites    . . 

tin.. 

zinc 

Cobalt   

■         arseniate . . . . 

dtrate 

oxalate    . . . . 

oxide    

sulphate  . . . . 

tartrate  . . . . 
Columbium 


Equivalent 
Number. 


129.8 
93.8 

186.6 
89.3 

160.3 
82.3 
74.3 
91.8 

263.3 
91.3 

100.8 

165.8 
86.3 

107.8 

118.8 
96.3 
30.6 

104.6 
93.8 
73.6 
38 
76.6 

100.6 

139 


Composition. 


Cit.  ac.  66.8  -|-  ox.  bismuth  74 
Cit.  ac.  65.8  +  ox.  cobalt  38 
Cit.  ac.  11 1.6  4-  ox.  cop.  76 
Cit.  add  65.8  -j-  ox.  iron  33.6 
Cit.  add  55.8  +  ox.  lead  104  6 
Citr.  ac.  56.8  -f-  lime  26.5 
Citr.  add  66.8  +  mag.  18.5 
Citr.  acid  55.8  +  ox.  mang.  36 
Citr.  add  56.8  -f  ox.  mere.  197.5 
Citr.  ac-  55.8  -f  ox.  mc.  36.6 
Citr.  add  55.8  +  pot.  45 
Citr.  add  55.8  +  ox.  silv.  1 10 
Citr.  ac.  56.8  -f-  soda  29.6 
Citr.  add  55.8  -f-  stron.  52 
Citr.  ac.  55.8  -f  ox.  tin  63 
Citr.  ac.  55«8  +  ox.  zinc  40.6 


Ox.  cob.  38  -f  ars.  ac  66.5 
Ox.  cob.  38  -|-  dtr.  add  66.8 
Ox.  cob.  38  -f  oxal.  ac.  35.6 
Cobalt  30.    -h  oxygen  7-6 
Ox.  cob.  38  +  sulp.  ac.  37*5 
Ox.  cob.  38  -h  tar.  add  62.6 


630 


AN    AkPHABfiTICAL   TABLE 


Substances. 


Rquiralaaft 
Number. 


Columbate  of  potash 


Copper  ..... 
-——acetate 


carbonate, 
citrate  ... 
•  muriate   . 


nitrate 


oxalate  of 


&  ammonia,  oxalate  of 
&  potash,  oxalate  of  .. 
&  sodi^  oxalate  of . . . . 


oxide 


2iid 


perarseniate   

protarseniate 

sulphate 

crystallized  .... 


sulphite  . 
succinate , 
tartrate 


Corrosive  sublimate 


Cyanogen 


Diamond 


191.5 
60 

171 

9C7 
18&6 
144 
176 
146 
197.5 
226.5 
211 

67.6 

76 
208 

134 

160 

235 

105 

114.8 

200 

257 

24.4 

5.7 


CoMPOsmoK. 


Col.  acid  146.5  4- 


45 


Ox.  copp.  75  -h  Acet  add  96 
Ox.  oopp.  75  +  caib.  acid  fiOJ 
Ox.  copp.  75  -H  citr.  add  111.6 
Ox.  copp.  75  -h  m.  ac  69 
Ox.  cop.  75  -H  n.  ac.  1<H 
Ox.  cop.  75  -j-  ox.  ac.  71 
Oxalate  cop.  146  -h  osaL  '■a.Sl 
Oxalate  cop.  146  +  ox.  potaah  88 
Oxalate  cop.  146  -h  oxaL  aaiaii 
Copp.  60  +  oxyg.  7*6 
Cop.  60  +  oxy.  15 
Ox.  cop.  75  -f  ars.  ac.  133 
Ox.  copp.  67.5  +  ara.  ac  66^6 
Ox.  cop.  75  +  sulp.  ac.  75 
Ox.  cop.  75  +  s*  a.  75  +  irtLi 
Ox.  cop.  75  -f  sul.  ac  30 
Ox.  copp.  67.5  +  sue  acid  47<3 
Ox.  cop.  75  +  tar.  add  126 
Mercury  190  -f  chlorine  d7 
Carb.  11.4  +  nitr.  13 


OF   CHEMICAL    EttUIVALENTS. 


631 


Substances. 


Flttoboric  gas  

Fluorine 

Gludnum 

CHucina 

Gold    

chloride   

muriate    

nitrate 

oxide    

phosphuret .... 

sulphuret 

Gam   

Gonmiate  of  lead 

Hydrofluoric  acid 
Hjdrophosphoric  gas 

Iiydrogen 

■  ■       carburetted .... 
— —  phosphuretted 
— —  sulphuretted  . . 

Inm 

— —  acetate 


Eqoivalmit 
NnnibCT'* 


20 
15 

20 
27.6 

97 

130.5 
139 
155 
104.5 
108 
127 

85 
274.5 

16 

13 

1 

6.7 
12 
16 

117.75 
26 
81.5 


Composition. 


Fluorine  15  +  hor.  5 


Glucinum  20  -f  oxygen  7.5 

Gold  97  -h  chlorine  33.5 
Ox.  gold  104.5  +  mur.  ac.  34.5 
Ox.  gold  104.5  +  n  add  50.5 
Gold  97  4-  oxygen  7-5 
Gold  97  +  phosphorus  1 1 
Gold  97  +  sulphur  30 

Gum  170  +  oxide  lead  104.5 

Fluorine  15  -h  hydrogen  1 
Phosp.  1 1  +  hyd.  2 

Carbon  5.7  +  hydrogen  1 
Phos.  11  +  hyd.  1 
Sulp.  15  +  hyd.  1 


Oxide  iron  33.5  +  acet.  add  48 


AN  ALPHABETICAL  TABLE 


Iron,  carbonatr  of 

^^— lat  chloride    

Zod  chloride   

chromate 

gtlUte 

muriite    

pecmuriate 

pemitTBte    

■ oxBlste 

oiide    

peroxide 

photphate 

phoapburet   

lulphate  (drv)    . . , 

——■  cry  stal'^C  7  waters] 

Bulphuret    

faiaulphuret 

peranenUte   

protaneniate 


76.26 
77 

93.3 


33.5 
37.25 


71 
130.5 


Oiide  iron  33.5  +  cub.  ac  S0l7 
Iron  26  +  chlorine  33.6 
Iron  26  +  chlorine  50.25 
Ox.  ir.  33  &  +  clir.  ac.  43.5 
Ox.ir.33  5  +citr.  ac66.8 

iron  33  5  +  gal.  ac  6!L7 
Ox.  iron  33.5  +  mur.  ac.  34.6 

iron  37.25  +  mur.  ac.  Cl.Tt 
Ox.  iron  33.5  +  nitr.  wid  fiOki 
Ox.  ir.  37.25  +  ■>■  add  7&7f 
iron  SaS  +  ox.  K.  3U 
Iron  26  +  oxyg.  7.5 
in26  +  oxrKen  11.25 
:.  iron  33.6  +  ph.  acid  26 
111  26  +  pboip.  1 1 
Ox  iron  33,5  +  luc.  add  47  J 
iron  33.5  +  sulp.  add  37.5 
D17  s.  iron  71  +  water  69.6 
n  26  +  sulphur  IS 
n  26  +  gulp.  30 
.  iron  37.25  +  ars.  «ad  99.76 
Ox.  Iron  33.5  +  an.  ac.  66.6 
iiun  33,6  +  tar.  acid  £2.5 


OF    CHEMICAL   EAUIVALENTS. 


SUBJTANCBS, 

"':;::;r' 

COMCOMTION. 

97 

Ox.  Ind  I04.S  +  -Mt.  >cid  48 
Ox.  led  l«.6  +  ui-  Kid  66.6 
Ox.  le^  104.5  +  ben  add  112 
Ox.  lead  104.5  +  cub.  ac.  20.7 

12G.2 

rblonrte    

175.5 

Ox.Ie«lie4.6  +  chlor.»c7l 

Alorido 

130 J 

L««]  97  +  chloriDe  33.S 

dumute  

ua 

Ox.  lead  104  5  +  chr.  k.  43.5 

Ox.  leu)  104.5  +  dtr.  mad  55.8 
Ox.  lead  104.6  +  gallic  acid  69.7 

g«II«t«  

IM.2 

165 

Ox.  lead  104.5  +  n.  ac.  50.fi 
Ox.  lead  20)  +  nit.  ac.  50.5 

259.6 

mihtp 

140 

Ox.  lead  104.5  +  oial.  ac.  35.5 

wddelrt  

1(M.6 

Lead  97  +  oiy.  7JS 

2iid 

|r)d.35 

L«^  97 +  M7- 11-25 

Srd  

\vi 

Lead  97  +  oiy.  16.0 

Ox.  lead  104.6  +  ph.  ac.  26 
Oi.  lead  104.5  +  ph.  ac.  I8.S 

ph<»pW"- 

12a 

Uad  97  +  ph<».  1 1 

I5i.e 
I't^ 

Oi.  leMl  104.6  +  xilp.  ac.  37.5 
Ox.  lead  104.6  +  .iilp.  ac.  30 

•"IjAfte 

l,U6 

112 

Lead  97  +  »ulph<ir  15 

UrtnUc 

16/ 

Ox.  lead  104.5  +  lar.  ac.  62.5 

AN    ALFUABETICAI.  TABLE 


StfOSTANCBG. 

NumUCT. 

c,.^.™«». 

Lead,  tcutrate  of,  tuid  potath 

274-6 

Oi.lead  104.5 +Ur.acl26+pt 

26.6 

Calcium  19  +  oxfg.  7.6 

Ume26.6+ac  ac.48 

anenUte 

93 

lime  26.6  +  an.  ac.  6&5 

Lime  26.5+  bonEokaiU  lU 

46,5 

Lime26J  +  bor.  ac.  SO 

Lime  26.6 +  c«H>.  AC  Sa7 

rhlorale     

97.6 

Lime  26.5 +  chlor.  add  71 

70 
82.3 

Lime  26.6  +  chr.  ac  43.fi 

-^dliftte  

L>me26.&  + citric  acid  6U 

hvil    t 

lime  26.5  +  water  8.5 
lime  26.6 +brd.  add  118.7 

Lime  26.5+  i»ur.  ac.34i 
Lime  26.5  +  nitr.  ac.fiO.^ 

oxidate 

62 

Lime26^  +  oiBlicac.36J 

oiyiodate 

Lime  26.6  +  oiyod.  a6i  IKi! 
Lime  26.6 +pho..ac.» 
Lime2C.6  +  pliM.ac.&2 

Lime  26.5+  sulp.  arid  37.6 
Sulp.  lime  64  +  water  17 

OTstBllized  

81 

s"lpWte 

66.6 

lime  26.6 +  s>ilp.  add  30 

LithU 

16.5 

Lith.  9  +  uiTiF.  7.5 

OF   CHEMICAL   SairiVALENTS. 


SuBtTANCES. 

Number. 

Composition. 

37.2 

87.6 
67 
42.6 
54 

U 
4i.6 

16.5 

18.5 

66.6 

86 

38.5 

39.2 

59.9 

89.5 

74,3 

27 
137.2 

63 

69 

54 

44.5 

66.8 

UMt.  16.6  +  catb.  ac.  20.7 

Lithia  16.5  +  nitr.  add  50.5 

pfco.ph.te 

"Ipfc*" 

Lithin  16.5  +  phoa.  add  26 
IJthia  16.5  +  >ulp   acid  37-6 

chloride  

ijih.  9.  +  chlor.  33.5 

Mag.  18.6  +  aceUcBdd48 
Mogn.  ia5  +  ani.ac66.5 
Mag.  las  +  bor.  acid 20 
Mag.  18.5  +  cart.,  acid  20.? 
Mag.  ia5+  carb.scid4i.4 
Mag.  18.6  +  chlor.  add  ?1 
Mag.  18.6 -t-citr.  add  66.8 
Magn.  18.5  +  watw  8.5 
Magn.  18.5+  hfd.Knd  118.7 
Magn.  18.5  +  mur.  add  34.fi 
MagQ.  16.6  +  nitr.  add  50.5 
Mag.  18.5  +  ox.  ac.  36.6 
Magn.  16.6  +  phot,  add  26 
M-gn.  18,6  +  futdn.  acid  473 

bontc 

biMTboutc 

(Uant«  .. 

dtnte 

hydato   

kTModalG 

•ealate    

-  (rfmiphatc 

■  luccinMc 

636 


AN   ALPHABETICAL  TABLE 


Substances. 


Magnesia,  sulphate  of  .... 

—crystallized  ..•. 

sulphite 

Magnesium 

chloride  

— -  oxide   

Manganese  

— —  acetate 

— — -  arseniate 

— — -  carbonate    

■  chloride 

•^— dtrate 

muriate   

— -»  nitrate 

— ^  oxalate    

oxide  I  st     

2nd    

3d  peroxide     . . 

— — —  phosphate 

•— —  phosphuret    

succinate  

—  sulphate 

Marble   

Mercury 


BqairataBt 

Ifunbor. 


66 
115.6 

48.6 

11 

44.5 

18.5 

28.5 

84 
102.5 

56.7 
62 
91.8 
63 
86.5 
71.5 
36 
39.7 
43.5 
62 
39.5 
83.3 
73.5 
47.2 
190 


CowpoamoN. 


Magn.  18.5  +  solp.  add  37^5 
8ulp.  magn.  56  +  water  S$£ 
Magn.  18.5  -|-  sulp.  acid  30 

Magn.  11.  +  chlorine  33i^ 
Magn.  II  -)-  oxyg.  7*5 

Ox.  man.  36  +  acet.  ac48 
Ox.  man.  36  +  ar.  ac.  66.5 
Ox.  nuuig.  36  -f  carb.  ac  i0l7 
Mang.  28.5  -h  chlorine  33w6 
Ox.  mang.  36  -h  dtr.  ac  5&8 
Ox.  nuuig.  28.5  -|-  mur.  ac  M 
Ox.  mang.  36+  nit^addSOlS 
Ox.  man.  36  -f  ox.  ac  35.5 
Mang.  28.5  +  oxygen  7*5 
Mang.  28.5  -h  oxygen  1 1.25 
Mang.  28.5  -|-  oxj^en  15 
Ox.  mang.  36  +  phos.  addSS 
Mang.  28.5  -f-  phosphorus  II 
Ox.  man.  36  +  sue.  add  47<3 
Ox.  mang.  36  +  sulp.  add37i 
Lime  26.5  +  carb.  acid  20.7 


OF   CHEMICAL   EQUIVALENTS. 


637 


Substances. 


Mercury,  acetate  of    

arseniate     

perarseniate   

borate    

perborate 

carbonate    

bicarbonate     

chloride  

bichloride 

citrate 

cyanuret 

hydriodate 

iodide    

per 

nitrate 

pemitrate 

■upemitrate 

oxalate 

>'—  peroxide    . . 

phosphate 

perphosphate    

sulphate 

>  persulphate 


Equivalent 
Number. 


245.5 

264 

338 

217.5 

245 

218.2 

2464 

2235 

257 
253.3 
238.8 
316.2 

307.7 

425.4 

248 

306 

460.5 

233 

197.5 

205 

223.5 

257 
235 
280 


Composition. 


Ox.  mer.  197.5  -f  a.  acid  48 

Ox.  mer.  197.5  -|-  ars.  ac.  66.5 

Ox.  mer.  205  +  ars.  ac.  133 

Ox.  mer.  197.5  -}-  bor.  ac.  20 

Ox.  mer.  205  -f  bor.  ac.  40 

Ox.  mer.  197.5  +  car.  ac.  20.7 

Ox.  mer.  205  +  carb.  ac.  41.4 

Mer.  190  +  chlo.  33.5 

Mer.  190  +  chlorine  67 

Ox.  mer.  197.5  -f  citr.  acid  55.8 

Mer.  190  +  cyan.  48.8 

Ox.  man.  197.5  +  hyd.  ac  118.7 

Mer.  190+  iodine  117.7 

Mer.  190  +  iodine  235.4 

Ox.  m.  197.5  +  nit.  ac.  50.5 

Ox.  m.  205  +  nit.  ac.  101 

Ox.  m.  410  +  n.  ac.  50.5 

Ox.  mer.  197*5  -|-  oxal.  ac.  35. 5 

Mer.  190-hoxy.  7.5 

Mer.  190  -h  oxy.  15 

Ox.  m.  197  5  -h  p.  acid  26 

Ox.  m.  205  +  p.  acid  52 

Ox.  m.  197.5  -h  sulp.  ac.  37.5 

Ox.  m.  205  +  >ulp.  ac.  75 


638 


AN 


TABLE 


SUBSIAKCBS.. 


Mercuiy,  soksvlplisfee  of  »•    i   242*5 


-^—  sulphite 

-—  solphnxet 

bkulphvrct   ... 

tartrate    ....••••»..• 

tiitrate  and.  potash  .. 

Molybdtota  of  ammonia  • .  •  • 
lead 


EqnWalsnt 


potash 
soda.. 


Molybdenum.  , 
— ^  ist  onde 
2Dd<Utto 


3d  ditto  . 
sulphuiet 


Nickel 


borate 


carbonate 
chloride  . 


citrate 

ferro-sulphate 

hydrate    

iodide 


227^ 
205 
230 
260 
367.5 
82.5 

171 
111.5 
96 

44 
51.5 
59 
66.5 

74 


28 

55.5 

56.2 

61.5 

91.3 

144 
44 

145.7 


CoBCPosmoif. 


Ox  m. 205+  8«lp.ac37^ 
Ox.m.  197.5  -h  svL  ac.3ll 
AL190  +  sulphur  15 
Mercury  190  +  sulphur  39 
Ox.  mer.  197^  +  tw.  ae.  €i 
Ox.mer.197.5H-  tarjw.l»ff 
Amm.  16  -f  m.  ac  <i6b5 
Ox.  lead  104.5  +  m-  actti 
P6tash  45  -f  m.  ac  66g5 
Soda  29.5  -f  m.  ac  66.5 

Molyb.  44  -j-  oxy.  7^ 
Molyfo.  44  -h  oxy.  15 
Molyb.  44  -h  oxy.  225 
Molyb.  44  +  sulp.  30 


Ox^n.  35.5  -I-  bor.  ac.  20 
Ox.  nic.  35^  -|-  car.  ac.  20.7 
Nic.  28  +  chlor.  33.5 
Ox.  a.  35.5  +  cit.  ac.  55.8 
Ox.  n.'35.5  -f  sul.  ac  75-f  osJrJ 
Ox.  nick.  35.5-1-  water  8JS 
Nick.  28+  iod.  117.7 


OF  CHBMICAb   ECIUIVALENTS. 


639 


Substances. 

I    Nickel,  nitrate  of   

oxalate    

oxide    

phosphate 

photphuret 

•ulphate 

—  crystallized  . . . . 

sulphuret    

— —  tartrate    

Nitrous  gas ^ 

or  S 

Nitric  oxide > 

Nitrogen  

— »-  chloride  of 

Nitrous  oxide 

Olefiant  gas 

Oxygen 

Oxychloric  acid    

noaphuretted  hydrogen 

Phosphorus 

»—  sulphuret  of  

Platinum  

—  muriate    

Potash  (dry) 


Equivalent 
Nainber. 


86 

71 

35.5 
61.5 
39 
73 

132.5 
43 
98 

28 

13 

147 
20.5 

6.7 
7.5 
86 

12 
11 

37 
90? 
? 
45 


Composition. 


Ox.  nick.  35.5  +  n.  ac.  60.5 

Ox.  nick.  35.5  -f-  ox.  ac.  35.5 

Nick.  28  +  oxy.  7*5 

Ox.  nick.  35.5  -f  phos.  ac.  26 

Nkk.  28  -h  phos.  1 1 

Ox.  nick.  35.5  -f  sulp.  ac  37.5 

Sulp.  nick.  73  +  water  59l5 

Nick.  28 -h  sulp.  15 

Ox.  nick.  35.5  +  tar.  ac.  ^.5 

Nitr.  13  -h  oxy.  15 


Nitr.  13  +  chlorine  134 
Nitr.  13  -h  oxy.  7-5 

Carb.  5.7  +  hydr.  1 

Chlorine  33.5  -f-  oxy.  52.5 
Phos.  1 1  -H  hydr.  1 

Phos.  22  +  sulphur  15 


Potassium  37.5  -f  oxy.  7*5 


640 


AN   ALPHABETICAL  TABLE 


SuBfTANCES. 

Potash,  acetate  of 

— —  anunonio-sulphate    . . 
^—  arsemate • 

—  binaneniate   

— ^arsenite  

benzoate 

borate 

— ^  carbonate    

—  bicarbonate 

—  —  crystallized  .... 
— ^  chlorate 

—  chromate 

— ^  citrate    

—  columbate 

— ^  fluate 

— ^  gallate     

hydrate 

—  hydriodate  

—  hydrosulphuret 

—  hypophosphite 

— — hyposulphite 

—  iodate  

—  molybdate  

—  muriate    


BqnWalenl 
NmnlMr. 


93 
136 
111.5 
178 
104 

167 
66 

65.7 

86.4 

94.9 

116 

88.5 

100.8 

1915 

61? 

104.7 
53.5 
163.75 
61 
? 
? 
200.2 
111.5 
71 


Composition. 


Potash  45  +  acet.  acsd  48 
Pot.  45  -f  sulp.  ac.  75  -H  ana 
Pot.  45  -h  ars.  add  66.5 
Potash  45  -f  arsen.  add  133 
Potash  45 -f  arsenknu  sod  0 
Pdtash  45  -f  bensoic  add  lU 
Pot  45  +  bor.  ac  20 
Potash  45  +  carb.  add2QL7 
Potash  45  -f  carb.  ac4L4 
Dry  salt  86  4  +  wsler8i; 
Potash  45  +  d&L  ac  71 
P6tash  45  +  chromic  add  43i 
Potash  45  4-  dtr.  ac.  55.8 
Potash  45  -h  col.  add  146.5 


Potash  45  +  fluor.  add  16 
Pot.  45  -h  gall,  acid  59.7 
Potash  45  + water  8.5 
Pot.45-hhyd.ac.  118.75 
Pot.  45  -H  sulphuretted  hydrsg 


Pot.  45  -h  iod.  ac.  155.2 
Pot.  45  -f  mol.  acid  66.5 
Potassium  37.6  -f  chlorine3& 


OF   CHEMICAL   laUIVALBNTS. 


«41 


SuaiTANCBI. 

^i';^:' 

PotMh,  nitrue  of    

9S.6 

Pot.  45  +  nit  w.  MS 

88 

PoUih'16  +  iiiti«ujMU43 
PotMli45  +  «u).«dd36.5 

ot*\M 

80.6 

116 

Pot.  46  +  ox.  add  71 

.upercUte   

IIG 

Poi.46  +  oi.mcid7l 

18? 

Potuh45-fox.mc.  143 

oxrchl<,n,K 

131 

PoUab4S  +  o»r.cM.M.86 

oiymuri-t, 

116 

PotMb  46  +  chloric  kU  71 

71 

Potuh  45  +  phoi.  (c.  26 

. biphoiplMte    

9- 

PotMh  45  +  phot.  Mid  52 

,ubpho.ph..e 

116 

Potuh  90  +  pfaoi.  uHd  26 

97 

Pot.  45  +  phos  «cid  62 

63.6 

Pbt.46  +  phoi,w.  18.6 

lubcarboiute 

657 

Potuh  45  +  c.rb.  K.  20,7 

Hirrinntr 

9S.3 

PoUih  45  +  .uc  Mid  47J 
Pot.46  +  .ulp.ac.37.5 

.ulphite 

82.6 

120 

Potuh  45  +  Bulp.  add  75 

.ttp*r...lph.f    

130 

Pot.  46  +  snip,  add  75 

76 

Pot.  45  +  Bulp.  ac.  30 
Potft.b  45  +  iw.  acid  62.6 
Potash  45  +  Ur.  arid  125 

.^bitutrate 

170 

■^—  lupf  rtartrats 

170 

Pot.  46  +  tar.  acid  125 

lungiute 

167-6 

Ptttuh  45 -Unng.  acid  112.5 

64% 


AN   ALFHABBTICAL  TABELB 


SuBSTANCBt. 


Pdtassium....... 

diloride  ... 

iodide  •.... 

—  peroxide  . . , 

—  phosphuret. 

protoxide 

sulphuret 

Prossicgas  «... 
acid 

Selenium 

—  add 

oxide   .... 

sulphuret. . 

Silica 

Silicium 

Silver 

acetate. . . . 

arseniate . . 

— ^  carbonate 

chloride  . . 

— —  chromate . . 

dtrate  . . . . 

cyanuret  . . 


EqniTalmt 
Nmmlier. 


37.5 

71 
166.25 

60 

48  6 

46 

62.6 

26.4 


376 

62.6 

46 
120 

30? 

16? 
102.6 
168 
176.6 

130.7 

136 

163.5 

166.8 

161.3 


CoMPosinoM. 


Pot.  376  -f  chlo.  33.6 
Potasnum  37-5  +  iodine  1177^ 
FotasMum  37.5  H-  oz3^geii  88i 
P6t  37.6  +  phosp.  1 1 
Potassium  37.5  +  ozygev7.6 
Pot.  37.6  +  sulp.  1 5 
Carb.]].4  4-  nitrog.  13 
Carb.  11.4  +  mtr.  13  -f  ky.  1 


Selen.  37.6  4-  oxygcii   6 
Selen.  37.5  4-  oxygen  7.6 
Selenium  75  +  sulphur  46 
Silicium  15  -f~  oxygen  16 


Ox.silv.  110  -facet,  add  48 
Ox.  silv.  110  -f-  ars.  ac.  66  6 
Ox.  silv.  1 10  -h  carb.  ac  2a7 
Silver  102.5  +  chlorine  316 
Ox.  silv..  1 10  +  chr.  add  43^ 
Ox.  silv.  1 10  -f  utr.  add  663 
Silv.  102.5  +  cyanog.  48.8 


OF  CHEMICAL  BAUIVALBNTS. 


043 


Substances. 


fiUver,  molybdate  of 

■  ■       nitrate 

oxalate 

oxide    

phosphate  

phosphuret 

sulphate 

sulphuret    

tartrate    

tartrate  of,  and  potash 

tungstate    

8oda 

»- —  acetate    

arseniate 

arsenhe 

benzoate 

borate 

carbonate    

bicarbonate 

chlorate  

oxychlorate    

chromate 

citrate    

fluate 


EqaiTalfliit 
Number. 


176.5 

160.5 

145.^ 

110 

136 

113.5 

1476 

117.5 

172.5 

280 

222.5 

29-6 

775 

96 

88.5 

141.5 

49.5 

50.2 

70.9 

100.5 

115.5 

73 

85.3 

45.5 
9 


CoMPOSITIOfC. 


T     9 


Ox.  silv.  110  +  m.  a.  66.5 

Ox.  silv.  1 10  +  nitr.  ac.  50.6 

Ox.  silv.  1 10  -f  ox.  ac.  35.5 

Silver  102.5  -f-  oxyg.  7.5 

Ox.  silv.  110  +  p.  a.  26 

Silver  102.5  +  phosp.  II 

Ox.  silv.  110  + s.ac.  37.5 

Silver  102.5 +  sulp.  15 

Ox.  s.  1 10  +  tar.  acid  62.5 

Ox.  s.  no  +  tar.  ac.  125  +  pot.  49 

Ox.  8. 1 10  +  tung.  ac.  1 12.5 

Sodium  22  +  oxy.  7  5 

Soda  29.5  +  ac  acid  48 

Soda  29.5  +  ars.  ac.  66  5 

Soda  29.5  +  arsenious  acid  59 

Soda  29.6  +  ben.  ac.  1 12 

Soda  29.6  +  bor.  acid  20 

Soda  29.6  +  carb.  ac.  20.7 

Soda  29.6  +  car.  ac.  41.4 

Soda  29.6 +  chl.  acid  71 
Soda  29  6  +  chl.  acid  86 
Soda  29.6  +  chrom.  add  43.6 
Soda  29^  +  citr.  acid  65.8 
Soda  29.6  + floor,  add  16 


644 


AN   ALPHAUSTICAL  TABLE 


SUBSTANCBS. 

BquiTsleat 
NwBber. 

Composition. 

Soda,  hjrdrate  of   

38 

Soda  29.5  +  ^^a^"*  8.5 

iodate    

184.75 

Soda  29.5  +  iod  ac.  155.25 

—  molybdate 

96 

Soda  29.5  +  mol.  acid  66.5 

64 

loas 

Soda  29.5  4-  mur.  acid  34.5 

ozjrmuriate    

Soda  29  5  +  chlo.  acid71 

—  nitrate 

80 

Soda  29.5  -|-  nitr.  ac.  50.5 

— —  oxalate 

65 

Soda  29.5  +  oz.  acid  35.5 

-—  phosphate 

55.5 

Soda  29.5  +  pl^os.  acid  26 

81.5 

Soda  29.5  +  phos.  add  52 

48 

Soda  29.5  +  phos.  acid  185 

—  succinate 

76.8 

Soda  29.5  -f  sue.  add  47^ 

sulphate    

67 

Soda  29.5  +  sulp.  ac.  37^ 

crystallized  .... 

152 

Sulp.  soda  67  +  water  85 

bisulphate  

104.5 

Soda  29.6  +  sulp.  ac.  75 

sulphite 

595 

Soda  29.6  +  sulp.  ac.  30 

37 

Sodium  22  +  sulphur  15 

92 

Soda  29.5  -f  tar.  ac.  62.5 

Soda  29.5  -f  tar.  ac.  125  +  pot  4$ 

and  potash   

199.5 

— —  tungstate 

142 

Soda  29  5  -f  tung.  acid  1 12.5 

Sodium 

22 
100.5 

chlorate 

Ox  sod.  29  5  -f  cUor.  ac.  71 
Sod  22  -f  chlor.  33.5 

chloride 

555 

iodide  

139.76 

Sod.  22  + iod.  117.75 

— —  peroadde     

33.25 

Sod.22  +  oxy.  11.25 

or   CHEMICAL   EAUIVALENTS. 


8..™k.„. 

CoMPosmoM. 

—  julphuret 

33 
37 
Cii 

100 
118.6 

12 

73.7 
123 
107,8 

611.5 
2(»7.3 

Bfi.5 
H12.5 

87.6 

7rt 

h;>.3 

811.5 
82 

1N.6 
4J.& 

7a 

tfi2.2 
62 
fiS.5 

Sod.  2-i  +  phoi.  1 1 
Sod  22  +  aulp.  16 

Slron.  52  +  nc.  ic.  43 

Strmilites  52  +  »ra.  acid  66.5 

CKbonate 

Btronlites  52  +  curb.  Bcid  207 
StronUUs  52  +  dilor.  tcid  71 

Slrontites  52  +  water  8.5 

iod... 

. 

Slronliles  52  +  mur.  mc.  34.S 

Sl^.■^til^^52  -(-  nil.  uc.  50  6 

8t™r..f.2+  ox-«<:.;-i5  5 

Stiwito  5-' +  phns, -rdSfi 

IrrLc 

Stran   5-2  4-  i-utdn.  udd  47.3 

Slron.  52  +  aulp.  noid  37-5 

StionUles  t>2  +  tir.  m.  62.5 

Stron.44.5  +  <:hlor.33S 

Strou.  44.5  +  tnrfincM?.? 

oxide 

phwphuret  

Strcn.  44  5  +  o»v.  75 
8tront.«.5  +  pho..  11 

940 


4K  AUPHAMSTICAL  TAULB 


SUBSTANCM. 


BtroDtium,  sulphuret  of  ••• 


BqalTalMit 


Sulphur 

Sttlphorftted  kydrogen 


Tamiate  of  lead 
TeUurium 


chloride 
ozido   .. 


Tin 


acetnte 


chloride  Ist 
chloride  2nd 


citrate 


muriate  . . 
permuriate 
nitrate  .... 


oxalate 

oxide    .... 
oxide  2nd 
phosphuret 
succinate.. 


&9S 

15 

16 


304.5 

70 
44.0 
55.5 
111 


aneniate 129.5 


sulphate 


89 

122.5 
118.8 
97.6 
139.5 
113.5 
98.5 
63 
70.5 
66.5 
110.3 
100.6 


Composition. 


Stront.  44.5  +  a  nip.  15 


Bnlpliar  15  -f>  hydrog.  1 


'^annin  200  -f  ox.  lead  lOU 

Tellurium  36.5  +  chL  3^5 
Tellurium  36^  +  oxj.  7.5 


Ox.  tin  63  H-  acet.acid48 
Ox.  Un  63  H-  ara.  add  66.5 
Tin  55  5  -h  chlorine  33.5 
Tin  55.5  -f  chlorine  67 
Ox.  tin  63  +  citr.  add  55.8 
Ox.  tin  63  +  mur.  ac  34.5 
Ox.  tin  70.5  -f-  m.  ac.  69 
Ox.  tin  63  4-  nit  ac.  50.5 
Ox.  tin  63  -f-  ox.  add  35.5 
Tin  55.5  4-  oxyg.  7  5 
Tin  55.5  +  oxy.  15 
Tin  55.5  +  phosp.  1 1 
Ox.  tin  63  +  sue.  add  47.3 
Ox.  tin  63  -f  sulp.  ac.  37-5 


or  CHEMICAL   BAUIVALBNTS. 


64/ 


Substances. 


Tin,  sulphuret  of 
— -  tartrate    . . . . 

Tungsten 

tuDgstic  acid 

fime 

manganese  . . 

Uric  acid 

Water    

Yttrium 

Yltria 

acetate 

arseniate. . . . 

borate 

carbonate  . . 
chlorate  . . . . 
chloride  . . . . 

citrate 

muriate   . . . . 

nitrate 

oxalate  . . . . 
oxide    


RqaiTalani 
Namber. 


70.6 
125.6 

90 

112.6 
139 
148.6 

33 

8.6 

30 
37.5 


33 

88.5 
107 

60.5 

61.2 
111.5 

66.5 

96.3 

76 

91 

76 

40.6 


Com  rosin  ON. 


Tin  55.5  +  sulp.  16 

Oz.  tin  63  +  tar.  acid  62.6 

Tung.  90  -f  oxyg.  22.6 
Tung,  acid  M2.5  +  lime  26.5 
Tung,  acid  1 12.5  -f  ox.  mang.  36 


Oxyg.  7.5  +  hydrog.  I 


Yttrium  30  -f  oxyg.  7.6 


Oxide  zinc  40.5  -f-  acet.  acid  48 
Ox.  zinc  40.5  +  ars.  ac.  66.6 
Ox.  zinc  40.5  -f-  bor.  ac.  20 
Ox.  zinc  40.5  -f  carb.  ac.  20.7 
Ox.  zinc  40.5  -f  ch.  ac.  71 
Zinc  33  +  chlorine  33.6 
Ox.  zinc  40.5  -|-  citr.  ac.  66.8 
Ox.  zinc  40.5  +  mur.  ac.  34.6 
Ox.  zinc  40.6  +  n.  a.  60.6 
Ox.  zinc  40.5  -f  ox.  ac.  36.6 
Zinc  33  -I-  oxyg.  76 


«48 


TABLE  OF  CHEMICAL  BOUIVALEMTS. 


SUBITANCSS. 

Niunbcr. 

CoMPOtrrioif. 

2Bdc,  pboaphate  of 

66.5 

44 

87.8 
.78 
137^ 

70.5 

48 
103 

35 

42.5 

Oj.  anc 406  +  ph.  mc,26' 

&Dc33  +  phosp.  11 

Oz.  zinc  40.5  -f  i uc  add  47.3 

sulphate 

f  ttlphite 

— -Bulphuret 

Ox.  sine  40.5  +  sulp.  ac  37.6 
Sulph.  anc  7B  4-  water  59.5 
Qz.  zinc  40.5  +  zulp.  ac  30 
Zinc  33  +  tulp.  15 
Qz.  zinc  40.5  4-  tar.  ac.  62.5 

Zircomum 

iSrconia 

Zinc  35  +  ozyg.  7.5 

*■■        -  v 

V.«'  I  -  >/ 


J.         neat 
A   LIST  OFTHE   WORKS 

QUOTED  IN  THE   ESSAYS. 


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Plates.  Olford  1663 

^^ ,  A  Continuation  of  New  Eiperimenti,  Fhyaico-Mecbanicat,  toucb-i 
ing  the  Spring  and  Wt'ight  of  the  Air.  and  iheir  Eflecti,  hr.  Ac. 
By  the  Hon.  Robert  Boyle.  Fvllow  of  ih«  Royal  Society.  4io.  with 
Platea.  Oiford  IKiig 

— .  The  Aerial  Noclilnca ;  or  tome  New  Phanomena,  and  a  I'Toceia 
of  a  FactiliuUB  Self-ilnning  SubM■nc■.^  Bythe  Hon.  Robert  Boyle, 
F.R3.      Thin  diwdccidw.  London  leao 

New  Eiperimcnts  and  GburvnIJons  touching  Cold,  or  an  ETperi- 

nuntal  Hisiory  of  Cold,  &c.  ;  with  an  Account  of  Freeiing,  bnnghl 
10  the  Royal  Sodetj  by  Dr.  Himt,  V.  R.  S.  By  ihe  Hon.  Robert 
Boyle,  F.B.S.  4la.  London  t6SS 


652  LIST  OF  WORKS  €IU0T£D: 

Bt^fe.— The  Fhiloaophical  Workiof  the  Hon.  Robert  Boyle,  abridged  bj 
Dr  Shew.  In  S  Tolumes,  4to.  1T3S 

— -.  The  Works  of  the  Honounble  Robert  Boyle.  Andrew  MiDar^i 
edition,  in  5  volumet  folio.  Londoo  ]  744 

•— -•  Medicina  HydroHtatica;  or  Hydroitatics  applied  to  Materia  Me- 
dica.  By  Robert  Boyle.  4to.  Losidoo  168S 

Brand.  Hie  Hiitory  and  Antiquities  of  the  Town  and  County  of  New. 
castle-upon-iyoe.     By  Jolm  Bnuod,  M. A,  F.S. A.  &c.    S  vols.  4to. 

London  1789 

Brande. — Outlines  of  Geology ;  being  the  Substance  of  a  Coarse  of  Leo- 
tures  delivered  in  the  Theatre  of  the  Royal  Institution^  in  the  Yesr 
1816,  by  Wm.  Thomas  Brande,  Sec  R.S.,  Professor  of  Chemistiy  at 
the  R.I^  &c,  &c  8to.  Loodoo  1817 

■  A  Table  of  FHme  Eouivalent  Numbers ;  drawn  up  for  the  use 

of  the  Chemical  Students  in  the  Royal  Institution.    By  ^W?illiam  T. 
Brande,  F.R.S.,  &c.  London 

A  Manual  of  Chemistry,  by  W.  T.  Brande,  F.R.&  &c   Seoond 


edition.  In  S  Tolumes,  8to.  18S1 

JSrice.'-'A  Unirersal  Geographical  Dictionary,  more  especially  of  the 
British  Dominions.     By  Andrew  Brice,  of  Exeter.    In  2  Tola,  folia 

1759 

Bruce. — ThiTels  to  discover  the  Source  of  the  Nile,  in  the  Yean  from 
1768  to  1773.  In  5  volumes,  4to.  Edinburgh  1790 

Brttce.'^The  Life  and  Acts  of  the  Most  Victorious  Robert  Bnioe^  King 
of  Scotland.  By  John  Barbour,  Archdeacon  of  Aberdeen.  Care- 
fully corrected  from  the  Edition  by  Andrew  Hart  in  16SCX  quarts 

Edinburgh  1758 

Buchanan.'^  An  Essay  on  the  Warming  of  Mills  and  other  BuiltOngs  fay 
Steam.  By  Robertson  Buchanan,  Civil  Engineer.  8vo.  Glasgow  1807 

-«— .  A  Treatise  on  the  Economy  of  Fuel,  and  Management  of 

Heat ;  with  Tables  and  Plates.     By  Robertson  Buchanan.  Svo. 

Glasgow  1815 

A<^^.— Natural  History,  General  and  Particular,  translated  by  WiUian 
Smellie  from  the  French  of  the  Count  de  Buffbn,  in  18  vols.  8va 

London  1791-S 

Butching.'^A  New  System  of  Geography.  By  A.  F.  Busching,  D.D., 
and  Professor  in  the  University  of  Gottingen.  Translated  from  the 
German.  In  6  vols.  4to.  London  1763 

Caledonian  Horticultural  Society.'^Memolrs  of  the  Caledonian  Horticul- 
tural Society.  2  vols.  8vo.  Edinburgh  1814-17 

Cafmi^n.— Britannia ;  or  a  Chorogmphical  Description  of  Great  Britain 
and  Ireland.  By  William  Camden,  Clarenccux  King  at  Arms. 
Translated  and  Revised  by  Edmund  Gibson,  D.D.  &c.  2  volumes, 
folio.  London  1723 

Campaigns.'^CampAgnes  des  Armdes  Fran9aiscs,  &c.;  or  the  Campaigns  of 
the  French  Armies  in  Spain  and  Portugal  in  the  years  1808  aiiid  1809. 
Vol.  I.  containing  the  Statistical  Description  of  Spain,  &c.    ocuvo. 

Paris  1809 

Campbell.^ A  Political  Survey  of  Britain.  By  John  Campbell,  LL.D. 
2  vols.  4to.  1774 

Oato.— M.  Porcius  Cato  concerning  Agriculture.  Translated  by  the  Rev. 
T.  Owen,  M.A.  &c.  8vo.  London  1 80S 

Caoallo.''--A  Complete  Treatise  of  Electricity,  in  Theory  and  Practice ; 
with  original  Experiments.  By  Tiberius  Cavallo.  8vo.  London  17T7 

■■         .  A  Treatise  on  Magnetism,  in  Theory  and  Practice ;  with  origi- 


LIST  OF  WORKS  QUOTED. 


Dtl  ExperimcDU.     Bj  TIberiu<  CiTallo,   F.R.8.  At.     Illu 
wilh  Cojipir-ptatH.     The  tbird  Edition,  wiita  ■  Sup[dnDci>l. 

London  I  MO 

Crltut. — A.  Comelii  Cplu  Mnixdim  Libri  Octo,  ex  Rvcenuonc  Lmnudi 
TurgB.  Alo.  Lugduni  Butavomni  178S 

OnJiivn. — The  OcDpn]  Biafrnphlcal  Dietioatrf;  cooMining  iin  Ae- 
coiinl  of  the  Lives  and  Wiitinm  of  the  most  eminent  nnons  in 
e^iTj  Nation,  |>srticularly  ihe  Britlsb  and  Irinhj  from  the  *Brh'«t 
■ccouaLt  to  the  prewnt  Time.  A  new  Edition,  rerited  and  ta- 
larged,  by  Alriander  Chalmen,  F.S.A.      In  38  vol*.  Sto. 

London  1813-17 

Oaj^lal.— Element*  of  Chemistr?.  By  M.  I.  A.  Chafital.  Pro&wor  of 
Chemi^iy  u  lUunCpeiier,  &c.  Trnniilalcd  liom  ilie  French  bf  Mr. 
Nicholmn.   InSToliima^o.  London  1791 

■  Cheminry  ii|)|ilifd  to  Art*  and  ManiifaclniTHi.  By  M.  I.  A. 
ChRpUi,  Member  and  Treasurer  of  the  French  Seiulr,  Mcmtwr  of 
the  Nuinnal  Iniliiute,  &c  &c.  Tnuukiled  frtnn  ibe  French.  In  four 
voli.  Dto.  London  IHOT 

dkordin.— Tlie  1'raieli  of  Sir  John  ChaMin  into  Penia  and  the  EaM 

luliei,  coniuining  the  Author'i  Voyage  from  Pwu  to  tipahan.  folio, 

London  I6M 

Charma. — Tlie  Art  of  Bieach'oi^  I^coe-gooda.  Couont,  and  Threadi  of 
every  Dcscriplion.  Illuttraicd  with  9  large  Plans  in  4to.  Bj  i>ajiH 
diH  Cliorms,  Inspector  of  Manufaitum,  Metnbu  of  the  Lf  ccum  of 
Ana,  tec.  Translated  from  the  Freiieb.  8to.  London  JT99 

Ciauarr. — The  Work*  of  Geoffrey  Ctuunr.  Compared  with  the  former 
Editionn,  and  many  valuable  M5S.  Bj  Jului  Utry,  Student  of 
Oirist  Church,  Oion.  folio.  Lornkm  ITMI 

Cbinh. — TraTeU  in  various  Countries  of  Europe,  Asa,  and  Africa.  Jij 
&<lward  Daniel  Cluke,  LL.D.    Iu1*oU.-IIo.         London  ISlO-16 

. ,  llie  Gas  Blow.pipe,  or  Art  of  Fusion,  by  burning  die  Gbhoui 

Con>tituenii  of  Water  ;  givinn  tlx  History  of  the  Fhilomphical  Ap. 
pamiui  so  denominated ;  ibe  Proofs  of  Analogy  in  lu  0|K'r«iioiii  to 

Account  of  Experiment^  -ith  this  Blow-pipe.  By'E.  D.  Cli^k^ 
LL.D.,  Profeswrof  Mineralogy  in  the  UniTenity  of  Camhridn,  Ac 
Btu.  Land.  IH 1 9 

Ctlbvlumi. — Soc  Philoiopbicat  Colteciions, 

CVmiruiu. — The  Theorf  and  Piacticc  of  Brewing.  By  Michael  Cora- 
brune,  Fnwcr.  tinted  with  Pcrmiwion  of  the  Mastw,  Waidms, 
and  Court  of  AHiitanta  of  the  Wor^pful  Company  of  Brewen.  4io. 
■ewed.  DodsJcy.  London  ITrtI 

CsmnuHiciiJhMI.— London  Medical  Communicatiom.  In  9  lolumes  ""o. 
JohiBon.  London  ITB4,  IT90 

ConHntr. — A  Description  of  Ceylon;  conloining  an  Account  of  the 
Country,  Inhobiunls,  and  Natural  Productions.  By  Jame*  Conli- 
ner,  A.M.   In  3  mis.  4ta.  with  95  EngnTings.  London  IBOT 

CgWi.— Hydioiilatical  and  Pneumatieal  Lectures.  By  Roger  Colet,  A.M. 
late  ProfeuoT  uf  Astronomy  and  Experimental  lltiloaaphy  at  Cant- 
bridge.  The  tecond  edition,  by  Robert  Smith,  D.D.,  Uauer  of  Tri- 
nity College,  Cambridge.  Hto.     Plain.  Cambridge  1147 

CnMwr.— ElcmenU  of  the  Art  of  Aeuyiog  Metali.  Id  two  Parts;  the 
Hnt  ranlaining  the  "nwory,  tbe  aeeond  tbe  Practice,  of  the  (aid  Ait. 
By  John  An£ew  Cramer,  M,D.  Tranilaud  from  the  Latin.  Illus- 
trated with  Copper-platt*.  To  which  ar.  addtd.  Notes  and  Obscr- 
Titioni  no)  in  the  Original.    8vo .  London  1 T4  [ 


654  LIST  OF  WOEK8  aUOTBD. 

^vnilx.— The  History  of  Offenhiidy  Ac  Bj  Dftvid  Cisnts.    Tnttdatcd 
from  the  High  Dutdi.  3  ndi.  8flo.  1766 

CVtR^^iircf.— Experiments  and  Observations  on  Animal  Heat.    Bj  Adair 
Crawford,  M.D.,  F.R.SS.  L.  and  E.    The  second  ediUon.  8vo. 

London  1788 

£>«tf.— Crell*8  Chemical  JonnaL   Translated  from  th«  German.   3  veU 
8vo.  T^ondon  1791-88 


Dai»0r.— L'lliade  d^Homcn^  traduite  en  Fkan^oisy  a«ec  daa  Rcmn^iMk 
Par  Madame  Dacier.  S  Tok.  12mo.  Amsterdam  1781 

Da  Costa.'^A  Natural  History  of  Fossils.  By  Emanuel  Mendea  da  Costs* 
F.R.S.  and  F.A.S.»  and  Member  of  tint  Imperial  Academy  JVBiCmiw 
Curiotorum  of  Germany.  4to.  London  1757 

Dakon.'^A  New  System  of  Chemical  Fhilosopfay,  Ftat  L*  bj  J^u  Xlal- 
ton.  Bto.  Bfancfaeater  1608 

^.  Ditto,  Part  II.,  by  the  same.  1810 

DoriMn.— Phytologia,  or  llie  Philosophy  of  Agricnltnre  and  Gardeaia^ 
&c.  By  Erasmus  Darwin,  M.D.,  F.R.S.&C.  4to.  London  1800 

■  Botanic  Garden,  with  Philosophical  Notes.  S  Tolumea,  Svo. 

1799 


Dory.— Chemical  and  Philosophical  Researches;  chiefly  concerning  Ni- 
trous Oxide,  or  Dephlogisdcated  Nitrous  Air,  and  its  RespintioiL 
By  Humphry  Davy.  8to.  London  1800 

— -.  Elements  of  Chemical  Philosophy.  By  Sir  Humphry  DaTy,  LL.D. 
&c.  &c.  Svo.  London  1818 

.  Elements  of  Agricultural  Chemistry,  in  a  Course  of  Lectmcs  ftr 
the  Board  of  Agriculture.  By  Sir  Humphry  Davy,  LL.  D.  F.R.SS. 
L.  and  E.,  M.K.I.  &c.  4to.  London  1813 

-*— .  On  the  Safety  Ltoip  for  Coal  Miners;  with,  some  Reaeerdica  oo 
Flame.  By  Sir  Humphry  Davy.  Svo.    Printed  for  R.  Hunter. 

London  1818 

Delaval.'^  An  Experimental  Ii^quiry  into  the  Cause  of  the  Changes  of  Co- 
lours in  Opake  and  Coloured  Bodies.  By  Edward  Hussy  Debval, 
F.R.S.    4to.  London  1777 

Diodortts  Siculus.-^The  History  of  Diodonis  Siculus,  containing  all  that 
is  most  memorable  and  of  greatest  Antiquity  in  the  first  Ages  of  the 
World,  until  the  War  of  Troy.  Done  into  English  by  Henry  Cogan, 
Gent,  folio.  Lcmdon  1653 

Dion  Cassius. ^^The  History  of  Dion  Cassius,  abridged  by  XipUlin. 
Done  from  the  Greek  by  Mr.  Mannitig,  in  9  vols.  Svo.    Lond.  1704 

Dusrrfa/tonf.— -Miscellaneous  Dissertations  on  Rural  Subjects.  8vo.  Ro> 
binson.  Lt  ndon  1775 

Dossie. — The  Elaboratory  laid  open.  By  Robert  Dossie.  6vo.  Load.  1758 

.  Institutes  of  Experimental  Chemistry,  &c.,  by  the  Author  of 

"  The  Elaboratory  laid  open."  8  vols.  Svo.  London  1759 

Drake. — Anthropologia  Nova ;  or  a  New  System  of  Anatomy.  By  J^rocs 
Drake,  M.D.,  F.R.S.  The  third  edition,  in  S  vols.  8vo.   Lond.  1727 

Dublin  5oct6'/y.— Essays  and  Observations  on  Trade,  on  the  Husbandry  at 
Flax,  on  the  Linen  Manufacture,  on  Brewing,  &c.  By  a  Society  of 
Gentlemen  in  Dublin.  8vo.  Dublin  1740 

Dugdale.^'^The  Antiquities  of  Warwickshire  illustrated  from.  Rccocds, 
Leiger  Books,  Manuscripts,  Charters,  &c.  By  Sir  William  Dugdalc. 
The  second  edition,  in  two  volumes,  folio ;  revised  by  Dr.  Thomas, 
Rector  of  Exhall.  London  1730 

Du  Ifo/df.— Description  Geoeraphiqne  et  Historique  de  TEmpiiv  de  hi 
Chine.  Par  J.  B.  Du  Hiude.  4  vols,  folio.  I^ris  1770 


LIST  OF  WORKS  UUOTED, 
Oviattn. — "Hm  Edinburgh  N«w  Dispcnuiorr-    By 


— TiM  Edinburgh  1 
1.  M.D.,  IltgiusPori 
or  Edinliurgb,  Jkc. 


DuwUinaM A  Trenllw 

betwwn  AgricuJture 
Ibe  Soil,  Sm.  ice.    B; 


Etlii.   Rto. 

ElmMaM—Tliiv 
Rtgit.  8va 


iVr&rr,— TraveUthmuBli  IWly  in  1771  and  1772.  BvJ.  J.  Frrlirr,  P™. 
fwMTof  Nalural  liHtorynt  Mitttu  in   Cou  -  - 

from  the  GenruB  by  H.  E.  Riupe.  Bto. 

Fergvian, — Lectures  on  Select  Sutgedx  in  Mechanics,  llydroatiidc*,  &c. 
By  Junes  FeijpiMin.  Bra. 

--  ■  FiTjpiwin'a  Lectures  on  Select  Subjectiu    Willi  Vote*,  ai 

Appendix,  Adapted  (o  the  Pn 

By  David  BrcwEier,  A.M.     Serond  edition,  in  3  to1>.  Sto.,  with  a 
4lo  Volume  of  Plate*.  Etlinb.  lUCie 

Fnrdi/ct. — Memoir*  couceming  Herculaneum,  by  Vni.  Fordyce,  M.A. 
Sio.  London  IIJO 

Feurcny.—Eltiamti  of  Cbemittry  and  Nalunl  HiMoiy.  By  A.  F. 
Fouicivy.  Fiftli  edition,  wiih  Noies  by  Dr.  John  Tbonuonof  Edin- 
burgh, in  three  voli.  Bvo.  Edinb.  IMX) 
■  I  -■  A  General  Sy.tem  of  Chemical  Knoitledgp,  and  its  Applica- 
tion to  the  Phenomena  of  Nature  and  Art.  By  A.  F.  Fourcroy,  of 
the  National  Inuilule  of  Fiance,  Couniellor  of  Slate,  Prafea^ur  of 
Chemistiy,  &c.  &c.  I  n  eleven  >ol>.  8vo.  ToDsLued  from  ihe  French 
by  William  Nicholson.                                                          London  IH04 

Fu!luime.—An  E*dy  on  Combustion,  viih  a  Tieir  to  a  New  An  of 
Dyeing  and  Painiinfri  ifherein  Uic  Phlogistic  aod  Aniiphlogittic 
llypo^cac*  aic  proved  erroncout.    By  Mr*.  FuUuune.    octavo. 

(TrAm, — The  Worki  of  Gcber,  Ibe  tnont  funnua  Ambiu  Prince  aad  Ph<> 
lowphar.  Faithfully  Englished  by  R.  K.,  a  Lo*cr  of  Cbymiatry. 
duoilechno.  London  167S 

Gdlerl. — Mvtallurgic  Chemistry  )  being  a  Syrtetn  of  Mineralogy  in  gene- 
ral, and  of  all  ibeAro  arising  from  lh>«  Science,  Ac.  TraiuUted  from 
the  German  of  C.  E.  Cellen  by  I.  S.  8vo.  London  1776 

Ctt&nR.— The  Hittocy  of  the  Decline  and  Fall  of  the  Roman  Empire. 
By  Edward  Gibbon,  Em}.  In  laroU.eto.  London  IROT 

GUIin. — The  History  of  the  World  from  the  Keign  of  Aleiander  Is  thai 
ofAugustui.  ByJohn  CUlie*,  LL.D.,  F.K.S.&C.   3  volv  4tD. 
London  II 

Glauber. — The  Workt  of  Jc*n  Rudolph  Glauber;  containing  a  greiU 
~    Variety  of  ChoicB  Secrela  in  the  working  of  Metallic  Minea,  and  the 


656  LIST  OF  WORKS  OUOTBD. 

-  Sepanrtionof  MetoU.  T^wi>liM«diiilo£n|^lqr  ChikCaplMrPKfcK^ 
tpl&o,  IxmdoB  1689 

GUniberj-^A  Descriptkm  of  New  PhDoic^hical  Furnaces,  or  a  New  An 
of  Distilliiig :  divided  into  five  Farts.  By  John  Rudolph  Glauber. 
Set  forth  in  English  by  J.  FMnd,  M.D.  4to.  London  1651 

Goguet.'^The  Orira  qf  La^  Arts*  and  Sdeoces,  Ac.  Translated 
from  the  French  of  the  President  Da  GogueL     In  S  rolume^  8va 

£dinbar|^  1775 

Gottm^pntw— Conunentotiones  Societatis  Reeue  Sdentiamm  Gattingenu» 
&c.;  or.  Memoirs  and  Transactions  of  the  Royal  Society  of  Gottin- 
gen.  In  1 1  vols.  4to.  Gottingen  1779-93 

Gottfin^w^ Description  of  a  Portable  Chest  of  Chemistry,  or  complelB 
Collection  of  Chemical  Tests,  invented  by  J.  F.  A.  GottUng,  PhiC 
of  Chemistry  at  Jena  in  Saiony.  Translated  from  the  original  Ger* 
man.  12mo.  London  1791 

CrUBin^tfr.— >A  Biographical  History  of  England,  from  Egbelt  to  the  Be- 
volution.  By  Rev.  J.  Grainger,  '\^car  of  Shipkke.  4  vola.  Svo.  4tfi 
edition.  LrfMidoo  1904 

Ooy.— Letters  A-om  Canada,  in  the  Tears  1806-8;  showing  the  present 
State  of  Canada,  its  Productions,  &c  By  Hugh  Gray,    octavo. 

London  1809 

Gfrfn.-«Principles  of  Modem  Chemistry,  systematically  arranged.  By  l>. 
Frederic  Charles  Gren,  late  IVofessor  at  Halle  in  Saxony.  IVu» 
lated  from  the  German.   Illustrated  with  Plates.    2  Tola.  6vo. 

London  1800 

Giw.— >The  Anatomy  of  Plants^  with  an  Idea  of  a  Philosophical  Histovy 
of  Plantb;  and  several  other  Lectures,  read  before  the  Royal  Society. 
By  Nehemiah  Grew,  M.D.,  F.RS.  &c  folio.  1589 

ITamtfton.— Camp!  Phlegnei ;  Observations  on  the  Volcanoes  of  the  TVo 
Sicilies,  as  they  have  been  communicated  to  the  Royal  Sodcty  of 
London.  By  Sir  William  Hamilton,  K.B.,  F.RS.  To  which  a  pew 
and  accurate  Map  is  annexed,  with  54  Plates  coloured  from  Nature. 
S  vols,  royal  folio.  Naples  1776 

J^anuMiy.— An  Historical  Account  of  the  British  Trade  over  the  Caspisa 
Sea ;  with  a  Journal  of  Travels  through  Russia,  Persia,  &c  By 
Jonas  Hanway,  Merchant.  4  vols.  4to.  London  1753 

Aormer.*— Observations  on  divers  Passages  of  Scripture,  illustrated  by 
means  of  Circumstances  mentioned  in  Books  of  Voyages  and  Travels 
into  the  East.     By  the  Rev.  Thomas  Harmer.     4  volumes,  Sva 

London  1776-87 
'  Ditto,  with  Additions  by  the  Rev.  Adam  Clarke.     8vo.  4  vok 

1808 

ITaMf/fuuf.— Voyages  and  Travels  in  the  Levant,  in  the  Tears  1749.59. 

Written  in  the  Swedish  Language  by  the  late  Frederick  Hasselquist, 

M.D.,  and  published  by  Charles  Linnaeus,  Professor  of  Botany  at 

Upsal,  and  Member  of  all  the  learned  Societies  in  Europe.     8va 

London  1766 
/r(ffl(rf.— The  Art  of  Dyeing  Wool  and  Woollen  Stuffs.*  By  M.  Hellot, 
Member  of  the  Royal  Academy  of  Sciences.     Translated  from  the 
French,  by  Order  of  the  Dublin  Society,  for  the  Use  of  the  Dyers  of 
Ireland.  12mo.  Dublio  1767 

Henckel, — Pyritologia;  or  a  History  of  the  Pyrites,  the  principal  Body  in 
the  Mineral  iun^dom.  The  whole  compiled  from  a  Collection  of 
Samples ;  from  visiting  Mines ;  fh>m  an  Intercourse  with  Nataial- 
ists  and  Miners ;  but  chiefly  from  a  Course  of  Chemic^ 


LIST  OV  WORKS  QUOTED;  657 

Tnmlaln)  fhnn  (be  German  or  I.  F.  Hcnckel,  ChteT  Director  of  Ihe 
Minn  si  Prcyberg  in  Saiony.  Sto.  Ixindon  IT5T 

Jfmrv.— ElementM  nf  Eincrimcnlal  Chtmatrj.  By  Willism  Henry, 
M.D.,  P.R.S.  &e.  The  Tth  edit,  in  9  fol^.  Sto.  London  IS t5 

,   The  Elemenlnof  Eipeiinunul  Clictnistry.    By  Villiun  Henry, 

F.(LS.,  Vice- Preodentnf  the  Lileru;  nnd  Phiiosopliiral  Society  at 
ManchHter,  &c.  ftc.  The  BIh  edition.    In  S  roll.  8va.      Lond.  IBIS 

. .  The  History  of  Great  Britain.  By  Uobcrt  Ileory,  D.  D.    Fourth 

cditioD,  13  toll.  Bto.  London  1603 

HerodMiu. — Hiatoire  d'Herodotp,  tnduite  du  Crie,  arcc  Ae»  NoIsl  P«r 
Fetru*  H.  Lercher.   9  toIi.  Sto.  1803 

.   Herodotui,  translated  rrom  the  Greek,  with  Notes.     By  the 

Iter.  Wm.  Belw.    In  four  toilnms,  Svo.  The  M  edit.      Lond.  180S 

Ilfriin. — Elementsof  Chemiatry  ;  comprehending  ■  Vorietyof  F«ct»  and 
Views  which  liaie  never  iKforc  been  communicated  to  Hu  World. 
Intended  for  tiis  Use  of  Farmen,  HaDUfacturFn,  Dyen,  and  other 
ArtisuH.    By  Kobert  Heron.  Bto.  pp.  e-J8.  London  IHOO 

Haied, — 'llio  llemains  of  Ilesiod,  tranilated  from  the  Greek  into  En- 
gliih  Verse;  with  a  Preliminary  Diuenation  and  Notts.  By  Charte* 
Aliniham  Elton.  ISma  London  1809 

Hig^iu. — Ei|ieriment«  and  Otwerrationi  made  with  a  view  of  improiing 
the  Art  of  compoJng  and  applying  Unlcareoui  Cements  &t-  By 
Bryan  Higgins.  M.U.  Bvo.  London  ITW 

.  An  E«y  on  the  Theory  and  Prvdice  of  Bleaching;  wherem 

the  .Sulphuret  of  Lime  t*  rccnmnrtided  as  a  Sulntiluta  for  Potooh. 
By  William  Higgtn.i,  M.R.I.A.,  Pmfemr  of  Chemiitnr  and  Mltte- 
ralogy  at  the  Repmilory  of  the  Dublin  Society.  Sto.     London  1799 

Highland  Ricuty. — Prize  Eiaays  and  Tronnclions  of  the  Highland  Socjeij 
of  Scotland,  vol.  i.  Svo.  3d  edition.  Eitinb.  IBIS 

~^ .  Ditto,  vol.  S,  3,  and  i.  Edinb.  1S0S-J6 

-.  Ditto,  part  1.  of  vol.  S.  Edinh.  !fll7 

J7u>ury. — llie  Hiklory  of  tiie  Worka  of  tlic  Learned.    In  1 3  voli.  quarto. 
London  16fl9.17ll 

Httiiigitifd.—The  Historic  of  England,  from  the  Time  that  it  was  fii>t 

inlubiled,  undll  the  'fime  that  it  t.m  lul  conquered.    By  Raphaal 

HolingHhed.    (  Commonly  nlled  bia  Chraniclei).    2  volumei,  folio. 

London  1^86 

HoUand.—A  Oenenl  View  of  the  Agriculture  of  Cheshire,  &c.  By 
Henry  Holland,  Member  of  the  Rmal  Medinl  Soc  of  Bdinborgb. 
8vo.  London  I  SOS 

Home. — Experiments  on  Bleaching,    By  Francis  Home,  M.  D.    Svo. 

Edinburgb  IT5S 

.    The  Principle*  of  Amcullure  and   Vegetation.     By    Frsnci* 

Home,  M.D.,  Fellow  of  the  Itoyil  College  of  Fhytidang  in  Edin- 
burgh.  Svo.  Millar.  London  1758 

Homrr. — The  IKad  of  Homer,  translated  hy  Alexander  Pope.  A  new 
edition,  with  Nom  Critical  and  Dhistrativr,  by  Gilbert  Wakefleld, 
U.A.  In  5  vols.  royalHvo.  Irftndon  IBOC 

■  The  Odyssey  of  Homer,  tnmUted  by  A.  Pope.  With  Noua,  by 

Gilbert  WakeHeld,  B.A.,  in  4  vols,  royal  avo.  London  IfWW 

ffwih-.— Philbwphical  Collections,  by  Robert  Hooke,  F.R.S.  For  ih« 
Yean  I6T:>,  1660,  1631  and  1683.  I  voL  4to.  London  IG83 

Hapion. — A  General  System  of  ChemtiCry,  Theoretical  and  Practical; 
digested  and  anwiged  with  a  particular  view  to  Its  Application  W  (ha 
Artfc  Taken  chirfy  from  the  Germu  of  M.  Wiegleb.  By  C.  R. 
Hop«n,  M.D.  Atm.  LocdoD  1789 

VOL.  II.  ■  2  U 


658  LIST  OF  WORKS  «lUOT£D. 

Home.^EaBnys  concerning  Iron  and  Steel ;  with  an  Appendix  on  char- 
ring Pit-coal,  so  as  to  render  it  a  proper  SoccfidaiiettTn  for  charred 
Wood-coaL  By  H.  Home.  London  177S 

fibi<gA/<m.— Husbandry  and  Trade  Improved ;  being  a  Collection  of  many 
▼aluable  Materials,  communicated  by  sereral  eminent  Members  of 
the  Royal  Society.  By  John  Houghton,  F.R.S.  With  m.  PrefiMv^ 
and  useful  Indexes,  by  Richard  Bradley,  F.R.S.     S  toIs.  octavo. 

London  1737. 

ITiillDn.— The  History  of  the  Roman  Wall  which  croesea  the  Isiand  of 
Britain  from  the  German  Ocean  to  the  Irish  Sea.  By  W.  Huttoo, 
F.A.S.S.   The  2d  edition,  8to.  London  I81S 

/mitim.— Elements  of  Science  and  Art;  being  a  Familiar  Introduction  to 
Natural  Philosophy  and  Chemistry.  By  John  Imison.  A  new  edit.. 
2  vols.  8vo.  London  180S 

/riMit.— A  Voyage  up  the  Red  Sea,  on  the  Coasts  of  Arabia  and  Egypt, 
&C.  By  Eyles  Irwin.  4to.  London  171K> 

Jbrn^ton.— An  Outline  of  the  Mineralogy  of  the  Shetland  Islands,  and  of 
the  Island  of  Arran.  By  Robert  Jameson,  Member  of  the  Royal 
Medical  and  Natural  Hi^ry  Societies,  Edinburgh,  &c   Small  4to. 

Edinburgh  1796 

.  Mineralogy  of  the  Scotdsh  Isles ;  with  Dissertations  upon  Fett 

and  Kelp,  &c.    Illustrated  with  Maps  and  Plates.    By  R.  Jameson, 

F.R.  and  A.SS.  of  Edin.  &c.  &c  2  vols.  4to.  London  1800 

■.  A  System  of  Mineralogy.  By  Robert  Jameson,  Regius  Piofessor 


of  Natural  History,  &c  in  the  University  of  Edinbur;g^  2d  editkm, 
S  vols.  8vo.  Edinb.  1816 

J^^nr«.— A  Treatise  on  Diamonds  and  Pearls.  By  David  Jeflfries,  Jevrd- 
ler.  8vo.  London  1751 

JbiJUfu.— The  History  and  Description  of  the  City  of  Exeter  and  its  Envi- 
rons.  Ancient  and  Modem.  By  Alexander  Jenkins.  8vo.  Exeter  180S 

JbAfUon.— History  of  the  Progress  and  Present  State  of  Animal  Chemi- 
stry. By  W.  B.  Johnson,  M.B.  3  vols.  8vo.  London  1808 

Johnstone.— 'An  Essay  on  Mineral  Poisons,  by  John  Johnstone,  M.B. 
Physician  in  Birmingham;  of  Merton  College,  Oxford;  Fellow  of 
the  Royal  Med.  Soc.  Edinb.,  &c.  and  late  Physician  to  the  General 
Infirmary,  Worcester.    8vo.  Evesham  1795 

Jonston.'^A  History  of  the  Wonderful  Things  of  Nature,  &c.  By  John 
Jonston.   folio.  1557 

Josejihus.— The  Genuine  Works  of  Flavins  Josephus,  the 'Jewish  Histo- 
rian. Translated  from  the  Greek  by  William  Whiston,  M.A.  folio. 

London  1737 

Journal.^  A  Literary  Journal.     Published  quarterly,  from  October  1744 

until  June  1749.    Complete  in  5  vols.  8vo.  Dublin  1744.49 

— -;-.  Journal  de  TEcole  Polytechnique,  ou  Bulletin  du  TravaQ  frit 

a  cette  Ecole,  15  Cahiers.  8  vols.  4to.  P^  1809 

.    The   Edinburgh   Philosophical  Journal.     Conducted  by   Dr. 

Brewster  and  Professor  Jameson.  8  vols.  8vo.  Edinb.  182$. 

.  Le  Journal  de  S^avans,  S23  vols.  12mo.  1665—1773 

■  Journal  de  Physique,  de  Chimie,  d'Histoire  Naturelle  et  (ks 

Arts ;  avec  des  Plainches  en  tailledouce.    84  volumes,  quarto. 

Paris  1777-1817 

.  Journal  des  Mines,  public  par  le  Conseil  dea  Mines  de  TEmpira 

Francois.  38  vols.  8vo.  Par.  an.  iii.  1796-1815 

— .  Journals  of  the  Royal  Institution  of  Great  Britain.  ^^tJL  i. 


LIST  OF  WORKS  ttUOTED.  659 

octato.   .  Sold  at  the  Huiue  of  Iha  InMhutton,    Alb«marlc-itrcct.  ' 

Juurnal. — Tlie  Journal  of  SciciH^  and  the  ArU.  Edilfd  M  die  Royal 
iDSIit.  of  Great  Britajn.    I'4  vols,  Std.  IBIC.33 

jHiuta. — FrancJici  Juiiii  F.  F.  ik  Pictura  Vstcrum  Libri  Im.    4(0. 

AniMcrdun  1G9T 

Jiitrtiol. — The  Sadrea  nf  JuTenat,  (ranslaled  and  iUunralcd.  B;  Francia 
Ilodgujit,  A.  M.  of  King*!  College,  Cambridge.  4to.       Lond.  I80T 

iWrg.—The  Uoivor™!  Cambin,  and  Cominrrcial  liutruclor.    In  3  noli. 

4lo.   By  I-fltrick  Kelly,  I.L.D.  Londoc  1811 

Knit — Uinta  to  GcntlemeD  of  Lauded  Propcny.    By  Nathaniel  Kent  of 

FuUum.  Svo.  London  1 775 

AldJ— Oullinen  of  Mineralogy.     By  J.  Kidd.  M.D..  Profe«or  of  Chc- 

nuMry  b  Ihs  Uniicraity  of  Oiford.  3  *oU.  Rto.  Oiford  IS09 

jnrwan.-~An  Earinulp  of  the  Trmpcialure  of  difierent  Latiludn.    By 

Richard  Kiraan,  Eau.   F.ILS.,  and  Member  ut  the  Academis  of 

SlacUiulin,  Upial.  Dijon,  Ar.  Svo.  London  ITa7 
.  ElemcnUofMinonlugy.  By  It.  Kirwan,  F.R-S.  M.It.I.A.  &c. 

ad  edit.  3  toll.  Bro.  London  1791-6 
.  Ad  Esaay  on  die  Analyus  of  Minend  Walen.  By  R.  Kirwan, 

Eaq.  F.R.8.  &c.  Sto.  Lond.  1799 

■  Gi.-ological  Esaayn.     By  Richard  Kirwan,  F^.  F.R.SS.  Lond. 

uul  Edinb.,  M.n.I.A.  &c.  &c.  8>o.  London  1T99 

Jla^imfA.— Analytical  Eauyt  (awards  promoting  tho  Oiemicat  Knowledge 

of  Mineral  SubUances.    By  Martin  Henry  Klaprolli,   Profe«ra  of 

Cbeminnr,  &c.  &c.   Translated  IVoni  tlic  German.  Svo.  vol.  i.  Lond. 

1801.  voL  ii.  Svo.  Lond.  1804 

i.i  Dictioiiiuure  de  Chimie.  Pit  M.  H.  Klaproih  et  T.  ffoHt 

4toU.8to.  Pari.  1810 

V«>r,— An  Hintorical  UaUtionoftheUIandofC^loD.  By  Robt.  Knoi. 

folio.  London  1681 

i'lrran. — The  Koran,  commonly  called  the  Alcoran  of  Mahonuned,  trani- 

lated  from  the  original  Arabic,  with  eiplauatarj  Noica,  Stc,  by  Gto, 

Sole,  Genl.  S  toIi.  Svo.  London  1801 

or  a  Ssrio  of  Eiperi- 

Hnplete  Coune  of  that 

Si:ieacc      Bv  J.   B.   Bouillon   Lagrange,  ProfeaKir  in  the  Cmtral 

Schooln  of  Ivis,  and  in  the  School  of  Pharmacy,  Ac,  &c.   llluMralcd 

with  ITlTatefc  Traiulatcd  Cram  the  French.  ItTOla-Svo.   Lond.  ISOO 

IjiJtotttan,- — New  Voyages  to  North  Amenca ;  containing  an  Account  of 

&c.  With  S3  Mapi  and  Plaici.  Trandated  from  the  Fivnch  of  the 
Bamn  Lahonlan.  In  9  voU.  Svo.  3d  edition.  London  1735 

Jji  Ln rule.— Notice  »ur  U  Vie  et  lea  OuTnue*  de  Lavoiiier.  Par  Jeromo 
lie  La  Lande.  Svo.  Pari»  1797 

Lanbt, — Keaearches  into  the  Properties  of  ^ring  Water ;  with  Medical 
Cautiuni,  illustrated  by  Caiea,  against  the  L'h  of  Lad  in  the  Can* 
uruction  of  Pump*,  Waler.pipei,  Ciitemi,  &c.  By  WUliam  Lanbe, 
M.D.  8to.  London  IHoe 

Zavuuw'. — Eaaaja,  Pbyvcal  and  Cfaemicat,  by  M.  L«T<nucr,  Meabtrof 
tho  Royal  Aodemy  of  ScieoCM  at  Pariii  &c  VoL  I.  TtuhUmI 
from  the  French,  with  Notei,  and  an  Appendia,  by  ThoOM*  Henry, 
F.R.S.  Svo.  Lot>dDal776 

—  ■■■  —  .  Etcmenti  of  ^enuHry  in  a  nem  Synenutic  Order,  containing 

2u  2 


€60  LIST  OF  WORKS  aUOTED. 

aH  the  Modern  Ducoveriei.  Illsgtrated  by  13  Copper-Opiates.  By  ML 
liiToiaier,  Member  of  the  Academies  and  Sodeties  of  Puis,  London, 
Orleaiu,  Bologna,  Banl,  &c.  Translated  ftom  the  F^rench  by  Bobeit 
Kerr,  F.R.  and  A.SS.  Ediob.  Fowtfa  edit.  8to.  Edinb.  1799 

Leigh.'^Tht  Natural  History  of  Lancaahire  and  Cheshire.    By  Charks 
Leigh,  F.It.S.  folio.  Oxford  1700 

Xelsiid.— The  Itinerary  of  John  Leland  die  Antiquaory,  publbhed  by 
Mr.  Thomas  Heame.  The  third  edition,  in  9  toIs.  Sto.  Oxford  1770 

Xem^ry.— A  Course  of  Chymistry,  &c.     By  Nicholas  Lemoy,  M.D. 
The  third  edition ;  tramlated  from  the  8th  edition  in  F^cn^.    Sra 

London  1696 

Zedte^-^An  Experimentil  Inquiry  into  the  Nature  and  F^rt^wgation  of 
Heat  By  John  Leslie.  Sro.  Illustrated  by  9  Copper-plates.  Mawmao. 

London  1804 

I    II.  A  Short  Account  of  Experiments  and  Instruments  dependiitt  on 
the  Relalions  of  Air  to  Heat  and  Moisture.  By  J.  Leslie,  F.R.S.£.» 


IVofeeeor  of  Mathematics  in  the  University  of  Edinbur^.  8vo. 

£dinb.l81S 

X«f ITM.— Lettres  Edifiantes  ct  Curieuses,  escrites  des  Misaons  Etrsngoi. 

ISmo.  27  Tols.  Paris  1707-49 

XMit.— Commerdum  FhihMophioo-Technicum ;   or,  the  Fhilosoplikal 

Conunerceof  Arts :  designed  asan  Attempt  to  improve  Arts,  Trades 

and  Mannfactures.    By  W.  Lewis,  M.B.  and  F.R.S.    quarto. 

London  1763 
Xc9Ml.<-£sBai  sur  TArt  de  la  Vcirerie.    Par  C.  Loysd.  octavo. 

Pans,  an«  Tin.  oa  180O 
XMeM.— An  Essay  on  Waters.  In  three  Ptats.  By  C.  Lucas,  M.D.  8vo. 

London  1758 

XlKyvfmt.— The  Nature  of  Things :  a  didactic  Poem.   TVunslated  froni 

the  Latin  of  Titus  Lucretius  Cams,  and  illustrated  with  Notes  Fhijb- 

logical  and  Explanatory,  by  John  Mason  Good.    In  2  volumes^  4kx. 

London  1805 

JlaonrfYMy.— An  Authentie  Account  of  an  Embassy  from  the  King  of 
Great  Britain  to  the  Emperor  of  China.  From  the  Papers  of  the 
Earl  of  Macartney.  By  Sir  George  Staunton,  Bart.  F.R.S.  &c  In 
two  vols.  4to.,  besides  a  fblk>  volume  of  Plates.  London  1797 

Ifoc/uiv.— Observations  on  the  Geology  of  the  United  States  of  America ; 
WTth  some  Remarks  on  tiie  E0ect  produced  on  the  Nature  and  Ferti- 
lity of  Soils,  by  the  Deoomm>sition  of  the  different  Chases  of  Rocks; 
and  an  Application  to  the  Fertility  of  every  State  in  the  Union,  in 
reference  to  the  accompanying  Geological  Map.  With  tvro  FI^bl 
By  ^l^lliam  Machire.  8vo.  Riiladelphia  1817 

Miaemter, — Elements  at  die  Theonr  and  Phictiee  of  Chemistry.  TVans- 
lated  from  the  French  of  M.  Macquer,  Member  of  the  Royal  Acad, 
of  Sciences,  and  Professor  of  Medicine  in  the  University  of  l^ris. 
In  2  vols.  Svo.  London  1757 

A  Dictionary  of  Chemistry;  eontaining  the  Tlieory  and  PtactiDt 

of  that  Sdence,  with  fbll  Explanations  of  the  Fundamental  Princi- 
ples of  the  Arts,  Trades,  and  Manufiu3tures  dependent  upon  Chonis- 
try.    TVanskted  from  the  French.   The  second  edit.    In  S  vob.  8vo. 

Lonihm  1777 

Jlacro6mf.<»Aur.  Theodosius  Macrobins.   Per  To.  Car.  Zeunium.  8vo. 

Lipde  1774 

Ifadoar.— The  History  and  Antiquities  of  the  Exchequer^  takoi  from  Re- 
cords. By  IhonoB  Medox.  lai^  Iblio,  London  I7IT 


LIST  OF  WORKS  Ot'OTKD. 


Bnncbn  uf  Science,  lie.        ,  

Sa  vols.  Bvo.  London  lTS>e.lS8I 
.  The  Neir  Agricultural  and  CcHntnercul  Maguutc^or  Ganeral 

Ucpaduyy  uf  Ant,  Muiui'sctiim,  and  Commerce.  In  S  tola.  Bvo. 
LonHoa  1811  and  ISIS 

.  The  L'nivcnal  Maguine  of  Knowledge,  Ac  In  IIS  fola.  Hto. 

London  1T4T-Ia03 
Manual.— The  GoldBiutb'i  IVIaDuali  or.  The  Sccreuof  the  Goldnnitta'a 

Art.   13nio.  Loodon  I6T6 

Manden. — The  History  oT  Sumalra ;  cnnlnmingBn  Aciviint  of  theKitui«l 

IVoduCtioiuor  the  Island,  &c.  By  W.  Manden,  F.ILS,4Ml  Lob.  HSS 
Uarlita. — Ad  UiUTcnal  Dictionaiy  of  Natuial  HiUoty,  in  Gennan,  by 

M.  Maniai.  4  tols.  6to.  inih  pUln.  Bcilm  and  Stelin  ITTS 

Maurice. — Indiui   AntHniides;  or  Diavrtaluini  TcUliie  10  the  Anc 

Oeogiaphical  Diiiuona  of  HiDdonui,  Ac.  &c  By  the  Rev.  Thonw 

Maurice.  In  7  vols.  8vo.  London  ISOO 

A/dTw. — 'Ihe  Dlinerslogy  and  Grolocy  of  Derbyshire  i  dcscritnng  Ihc  Pro- 
ductions of  the  Mines  and  the  PiHlion  of  the  Strata,  I'lbOui^  by 

Engraving  he.  lly  J.  Miwe.  No.  149,  Stiuid.  Lnnil.  8vo.  (as  dalf) 
.  'IVaveLt  m  the  Iiiuriorof  Bradl.  By  Joha  Maw*,  Author  of '■  Tba 

Mioenlt^  of  Dcibyshirv,"  &e.  4to.  Loudon  IS  15 
.  TreaiJse  on  Diamonds  and  Fndous  StODes ;  including  their  His- 

loiy,  Nsluni  and  Conuxicrcial ;  with  colouml  Platos.  Uy  J.  Hawc. 

Second  edition.  Svo.  London  ISIJ 

JUa^ii'.— Tractatui  i|uini]ue  Medico- PhyHci,  Ac.    Studio  Joh.  Mayow, 

LL.D.  M  McJici ;  nccnon  (.'-oil.  Omu.  Anun.  in  Univ.  Oion.  Sodt 

Xto.     Oionii  c  i-hcairo  Slieldonianu.  An.  Dom.  1«T1 

ilcdieal  and  P/tyricnl  Ji,Hmal^—iiriiia.l  and  Physical  Jouioal,  from  Vol. 

15  to  Ibe  pratiit  Time.  8to.  London  1806,  Ac 

Urdicnl  TrOK^KtiifU — Medical   Transactjons  by  the  College  of  PhjtsU 

dans  in  London.  5  vols.  Bvo.  London  1785-1811 

Jfi^moipe— Mir  I'Acicr,  Ac,  par  J.  J.  Perrey.  Correspondent  of  the  Royal 

Acadnay  of  Ueiian,  and  Hononfy  AaodaM  at  the  Society  of  Atta 

at  Geneva.  Svo.  I^iis  1779 
jr/motrci.— MctnoirendeUSociAtdBHcdednede  Paris.  Par.  1778 
.  Mcmoitvi  do  TAcadeinio  Iniporiale  tt  Royale  det  Sdcncc*  et 

de^  Belln  LetlrRi  di  Bruielles.  4  vols.  4to.  BiuiMla  17n-e9 

Uemoin—ot  tht  Lilcroiy  and  Philosophical  Society  of  Manchcsta'.   Fiva 

vols,  evo.'  1T85-9B 

.  Ditto,  Kew  Serin,  in  3  vols.  1B19 

...  Memoirs  of  the  AnKricao  Academy  of  .Art!  and  Sciences.  One 

vol.  4ta  UoitDn  I7S5 

3irtaU.—  \  Collection  of  Scarce  and  Valuable  Tmtiae*  upon  Metals, 

Hinea,  and  Minerals.   In  four  Parts.  8vo.  London  1738 

JtfiBrr.^-i'bysical  and  Metaphyseal  loiguirica.  By  Walter  MiUer,  of  Perth. 

Sto.  London  I  HOG 

JfimDn.— A  New  Vo)'*g«  lo  Italy,  with  curious  Obwrvations  on  several 

Mber  Countnes.  In  3  vols.  Hvo.  By  Maiimilian  Ulwon.  Lond.  IT39 
HilHnjn       Thr  Works  al  Lwly  Mtrj  Wortley  Montagu,  including  her 

Corrcapondencd  Ac.    Publiihed,  by  pomiiaioa,  fnnn   her  Genuine 

Papers.  Stb  edition.  In  Svolunm,  iSmo.  I^ndon  ISOS 

Jl/AnMSfvint^-'llM  Spirit  of  La**(  inuulated  from  the  Fimch  of  the 

Bum  De  Wmlitquku.   Tenth  edition.  V  vol*.  London  1773 


662  UdT  OF  WORKS  aUOTED. 

JI^4ml/!itiCon.—L*  Antiquity  Expliqu6e  et  Repmentfe  en  Figures,  cvec 
Supplement  10  vols.  foL  Fkiis  172S-4 

J/brton.— The  Katunl  History  of  Northamptoiiahire,  with  some  Account 
of  tbe  Antiquities.    Bt  J.  Morton,  M.A.  &c.  fblio.         LondL  I71S 

Uotes.'-A  Collection  of  Vases,  Altan,  FMersp,  THpods,  Ganddsbra, 
Stfcopluigi,  &c  from  ▼arioos  Museums  &&,  engnnred  on  170  Fktca. 
By  Heniy  Moses.  With  Historioal  EaMys.  4to.  LoodoB  1814 

Jl/tcntw.<— A  CompantiTe  View  of  the  Huttonian  and  Neptunian  Systans 
of  Geology;  m  answer  to  the  IllasiiBtioos  of  the  Huttonian  Theorf 
of  the  Earth  by  Professor  Playfimr.  8to.  Edinburgh  18Q9 

■  u  A  Syrtem  of  Chemistiy.  By  J.  Murray,  Lecturer  on  Chemistry, 
and  on  Materia  Medica  and  Pharmacy.  In  4  toUu  8to.  Sd  edit. 

Edinbu  1809 

■  A  Companion  and  usefbl  Guide  to  the  Beauties  in  the  Western 
Islands  of  Scotland,  and  in  the  Hebrides.  By  the  Hon.  Mrs.  Mnnay. 
2  Tols.  8vo.  London  1799^1808 

AUffiiilA.— Elements  of  Affriculture.  By  John  Naismitfa,  Andxar  of 
the  "  General  View  of  3ie  Agriculture  of  Clydesdale^"  &c.  &c  Bwtk 

Lofidoa  1810 
Abi.— Tlie  Art  of  Making  Glass.  TVanslated  fiom  the  Italian  of  Anto- 
nio Neri.  By  Dr.  Merret.  12mo.  London  166S 
ASnifNonn.— Hie  Chemical  Woilu  of  Caspar  Neumann,  M.D.,  Professor 
of  Chemistry  at  Berlin,  F.R.8.  &c.,  abridged  and  methodised ;  with 
larffs  Additions,  containing  tbe  later  Discoveries  and  Improrementi 
made  in  Chemistry,  and  the  Arts  depending  thereon.  By  ^^Onm 
Lewis,  M.B.,  F.R.S.    The  second  edition,  in  two  volumes.    Svo. 

London  177S' 

NewUm. — Isaad  Newtoni  Opera  quae  exstant  omnia.   ComrnentariBflhis- 

tiabat  Samuel  Horsley,  LL.D.  &c.  5  vols.  4to.        Londion  1779-8S 

Nicholmm^^A  Journal  of  Natund  Philosophy,  Chonistiy,  and  the  Arts. 

Illustrated  with  Engravings.  By  William  Nicholson.  In  5  vols.'4to. 

London  1797-1808 

— .  A  Journal  of  Natural  Philosophy,  &c,  from  January  180S  to 

1813.  36  vols.  Bvo.  London  1 809- IS 

•.  A  Dictionary  of  Practical  and  Theoretical  Chemistry,  vrith  its 


Application  to  the  Arts  and  Manufactures,  and  to  the  Explanatioa  of 
the  Phenomena  of  Nature.    By  William  Nicholson.    Thick  8vo. 

London  1808 
iViefruAr.— Voyage  en  Arable,  &c.,  par  C.  Niebuhr.    2  vols.  4to. 

Amsterdam  1776 
^tfrdrn.— Voyage  d*Egypte  et  de  Nubie,  par  M.  Frederic  Louis  Norden, 
Capitainc  des  Vaisseaux  du  Roi.    'IV)me  premier,   folio. 

Copenhague  1755 

Olearius. — Voyages  faits  en  Musoovie  et  Perse,  &c.    Par  Adam  Olearius. 

2  vols,  folio.  Leyde  1719 

Oric%.— Essai  surle  Blanchement.  By  M.  D'Orelly.  Sold  by  Deterrille. 

Pkris  18S0 

Bi^.— Natural  Theology;  or  Evidences  of  the  Existence  and  Attributes 
of  the  Deity,  collected  from  the  Appearances  of  Nature.  By  William 
Paley,  D.D.,  Arcbdeaoon  of  Carlisle.  5th  edit.  8va      London  1803 

Paris. —  Pharmacologia ;  or  the  History  of  Medicinal  Substances,  &c 
By  John  Ayrton  Paris,  M.D.,  F.L.S.  &c.  Fourth  edition.  8vo. 

•    London  1820 


LIST  OF  WORKS  ftUOTED.  fiflS 

Parij-~-TnJeU  in  the  Interior  Districts  of  Afiin.  By  Itlungo  IVk, 
Surgnni.  With  ui  Appendii,  by  Mijor  lUnnell.  4ta.      Lroid.  I7£>9 

/■□rJ-iiuDn.— The  CHcmical  Pocket- Book,  or  MemonuMU  Chemica:  ar- 
cxnged  iuB  Cumpcndium  of  Cbcmiitrjr.  By  June  Parkinwn,  Tint, 
ton.    Fourth  Edition,  with  the  lilcat  Diwoverio.  Crown  octaia 

London  I  SOT 

< .  Organic  Rcmmliu  of  a  rortner  World.    An  Eiaminalion  of  the 

Miuenliied  Remain*  of  the  Vi^ctablea  and  Animals  of  tlie  Antedi- 
luvinn  World,  generally  termed  Giinin«>u&  Fouil*.  By  J.  Parkin. 
too,  Hoiton.  3  tol^  4to.  Londun  IMH-1 1 

Pavtanias.— The  Detrription  of  Greece,  by  Paunniaa.    TnuuUted  rrom 

the  Greek,  with  Notes,  bj  Thomai  Taylor.   Three  volume*,  oUbto. 

London  IT94 

FtaTion.—A  TranUalion  of  the  Tabic  of  Cbeminl  Nomenclature  pro- 
poaed  by  Dp  Guylon  and  othen ;  to  vhidi  are  nilnoined  Tables  of 
Elective  Att>vtioni,ltc.  By  G,  Peanon,  M.D.  SH  edil.-tto.  Li>n.lT99 

Peilat.—A  Menunr  on  the  Oripn.  IVogms,  and  Improvmieni  of  Gltm 
M»nu(ictutea;  including  an  Aeeount  of  ibe  Fateni  (.'iy^aUit.Centmie, 
or  Glaw  InCTiKtation^    By  Apsley  Pellnti,  Jun.   Iio.   London  1831 

fVntumf.— A  TourinScatlaiuClT6».  Sy  IVoUS  PeniiaDL  -lib  edition. 
•Vo.  London  1776 

PerriuU. — EsMyi  Medical,  Hiilot^ioil,  and  ElperitnentaL  By  IIwb. 
PeTcivn),  M.D.,  Fellow  ofihe  Royal  Society,  aitd  of  the  Sodctj  of 
Antiquaries,  London.   In  9  rol*.  Bvo.  London  1776 

iVmiw. — A  Voyage  round  the  World,  performed  in  the  Yeari  17B5, 
ne«.  1787,  and  I7M8,  by  the  BouHoIe  and  Aunibibe,  under  the 
cuuimand  of  J.  K.  G.  dc  la  I'^rouw.  IVatnilated  from  the  French. 
In  S  volume*,  igtinrtoi  with  ■  folio  Alias  of  Plates  and  Charts. 

London  1799 

FrilHi  -~F1cUi  Minor ;  ilw  Ijiwi  of  Art  lud  Nitun,  m  Amying  and 

Itcfinina  MelaK    Ily  Sit  John  Pcttus,  Knigbi.  (olio.      L<uid.  IGt)6 

■  Fodinip  H<;5i1fs ;  or  the  Hisiory,  Laws,  and  Places  of  the  chief 

Mines  and  Mineral  Works  in  EngUnd,  Wales,  and  Ireland.  By  »> 
John  Petlu),  Kn-f-lil.  foUo.  London  1670 

FhilHpt. — An  Elemvntnry  Introduction  to  the  Knowledge  of  Mineralogy. 
By  William  Plilllips,  Member  of  the  Geological  Sudoty.   l3]no. 

London  ISIS 

—  ■  i»  A  Selection  of  Facts  from  the  best  Authorities,  arranged  so  at 
(o  form  an  Outline  of  the  Geidogy  uf  Engbind  and  Walea.  With  ■ 
Map  and  S.-c::.>ii>  of  the  Strgis.  By  William  Philhps  M.G.S., 
Author  of  "  (>i!tlines  of  Minenkwy  and  Geology,"  and  of  "  An 
Elemenlary  Inlio^lui-tion  to  Mineral^y,"  &e.    ISmo.       Lond.  1S18 

FhOaioiilncal  T^nutriimi. — Philasophical  IVaniactionE,  from  the  Year 
ISeStothepteMiiiTime.    In  ll'J  vols.  4to.  London  16C5-IB3S 

lYotU.— The  J«wel'Housc  of  Art  and  Nature;  with  New  EiperimenW 
in  Ituhbandry,  l&tillalion,  Jkc.  By  Hugh  Platte,  of  Liocolnes  Inne, 
Gentleman.    410.  ISM 

i'ltn^.— Niiunll  Iliston'e,  By  Caius  Plinius  Secundus.  Translatwl  by 
Philemon  Holland.  9  voU.  folio.  London  IGOI 

H«(.— The  Natural  History  of  Staflbrdshire.  By  Bohen  Plot,  LU  D.. 
Keeper  of  the  Aahmolcan  Mu&auin,  and  IVofwor  of  Chemistry  in 
Uw  t'niveruty  of  Oxford,   fol.  Oion.  1686 

/ViUaraA.— Plulardi's  Lives.  Translated  from  the  original  Creek,  with 
Note*  critical  and  hisiorical,  and  a  Life  of  Plutarch.  By  Jolin  L^ng. 
home,  D.D.,Knd  Willum  Unghoine,  M.A.  The  fiih  edition,  in  C 
volf.  Svo.  LcodoB  IBOl 


684  usT  or  works  auoT£D» 

JI^m/^.— A  General  View  of  the  Agncultore  of  Sfaropehira^  with  Ob> 
lenratknis.  Dnwn  vm  for  tbe  Consideration  of  the  Boerd  of  Agri- 
cultuie.  By  Jottepk  riymlej,  M*  A«,  Arcfadeeoan  of  SelofH  ice  Bm. 

London  I80S 

J\»codfaf.— A  DeKripdon  of  the  East,  and  some  other  Coontrics.  By 
Bichard  Pococke,  LL.D.,  F.R.S.  2  toIs.  folio.         London  1743-5 

i^Mnet.— A  General  History  of  Dmgi.  By  Peter  Pomet.  Repoblisbed 
l^hisSon  Jos.  Pomet,in2Tola.  4to.  London  1735 

Pstt.— Lithogeognosie  Pyrotechnique,  on  Bzamen  Chymiqne  dea  Pienei 
ec  del  Terres  en  general,  &c.  Par  M.  J.  Pott,  R^imaeiir  en  Cfajr- 
mie  de  Beriin.  8  toIs.  ISmo.  Puis  1758 

Friaileiy. — Hutoryand  Present  State  of  Electricity,  widi  original  Eipe- 
riments.  By  Joseph  Priestley,  LL.D.,  F.R.S.  Hie  4tfa  edition.  4tn. 

London  1775 

■p  .  A  Familiar  Introduction  to  the  Study  of  Electridtj.    By  Jos. 

Priestley,  LL.D.,  F.R.S.    Hm  fourth  edition,  8to.     London  1786 
Experiments  and  Obseprations  on  different  Kinds  of  Air,  and 


other  Branches  of  Natural  Philosophy  connected  with  the  SqljecL 
In  3  Tols.,  being  the  former  six  vols,  abridged  and  methodised,  wiih 
many  Additions.  By  Joseph  Priestley,  LL.D.  &c  Sfo.  with  Platesi 

Binnini^iam  1790 
Experiments  and  Observitions  relating  to  the  Analyaia  of  Atmo- 


mberical  Air,  &c.  Read  before  die  American  Fhilosopfaical  Sorieiy, 
Feb.  5  and  19,  1796.    By  Joseph  Priesdey,  LL.D.  &c.    Sro. 

Philadelphia  179S 
Hie  History  and  Bresent  State  of  Discoreries  relating  to  Vi- 


sion.  Light,  and  C<^oun,  By  Joseph  Priesdey,  LL.D1.,  F.R.S.  In 
2  voU.  4to.  with  Plates.  London  177S 

J^vcDMS.— The  Secret  History  of  the  Court  of  the  Emperor  Justiniaa. 
Written  by  Pkocopius  of  Cesatea.  Faithfblly  rendered  into  FngliA, 
12nio.  London  1674 

JBoi^mf.— Happort  fait  i  la  Sod^t^  d* Encouragement  pour  Tlndostrie 
Nationalc,  au  Nom  d*une  Commission  Spcdale  sur  les  Aders  Da- 
masses  de  M.  Sir  Henry,  &c.    Par  M.  H^ricart  de  Hiury.    4to. 

Pans  18S1 

II  Second  Rapport  fait  k  la  Soci^t^  d*£ncourageraent  pourTIndu- 

strie  Nationale,  au  Nom  du  Comit6  des  Arts  M^chaniques,  sur  les 
Lames  Damass^es  de  M.  Degrande-Gurgey,  de  Marseille.  Par  M. 
le  Vicomte  H^ricart  de  Thury.  4to.  Paris  1821 

Matjte, — An  Account  of  some  German  Volcanoes,  and  their  IVoducdons, 
by  R.  £.  Raspe.  8vo.  London  1776 

JEUty. — Three  Fhydco-Theological  Piscowses.  By  John  Ray,  F.  R.&  8vo. 

London  1713 

J{€aiimiir.— L*Art  de  convertir  le  Fer  en  Aden  Par  M.  Reaumur. 

PsrisHSS 

JReei, — The  New  Cyclopaedia,  or  Universal  Dictionary  of  Arts,  Sciences, 
and  literature.  By  Abraham  Rees,  D.D.,  F.R.S.  4to. 

Jlqxrrtofy.— The  Repertory  of  Arts,  Manufactures,  and  Agriculture; 
consisting  of  Original  Communications,  Spedfications  of  Patent  In* 
▼entions.  Practiced  and  Interesting  Papers,  &c  57  vok.  8fo. 

London  1794-1822 

HepuJbtic  oJJLeUers, — The  Present  State  of  the  Republic  of  LetterB,.in  18 
vols.  8to.  Published  monthly.  London  1728-86 

i^^lro^pcc/.— Retrospect  of  Philosophical,  Mechanical,  Chemical,  and 
Agricultural  Discoveries.  8  vols,  8vo.  London  1806-13 


LIST  Ol"  WOilKS  aUOTED. 


G65 


SctietD. — Tlid  Monthly  Hetjen',  or  Literwy  JounuL  St  rolumo,  8*0. 

London  1T4»-B9 

.  The  Moaihly  BeTfci.  Enlvged.  New  Sena.  100  vols.  Sto. 

I^odoolTlO-ISXS 

RaJiardmn. — The  Clicniinl  FriDcipIra  of  [bo  Metallic  Arts,  dcvgned 
ebie&j  for  the  Uw  oT  ItlanufBiturrra  1  willi  an  Account  of  th* 
principal  Diteasa  incideai  to  (he  dilltvent  AnJGcm,  aiul  the  Mean* 
of  Prerentkin  and  Cuie.  By  WilUoiti  lUchanLiaa,  Sur^n,  F.S.  A. 
&c.  Sid.  Birmingham  1T90 

Rhoda.—Aa  Enay  ontbe  Maniiiiiclurt  of  ■  Razor.  By  E.  Ithodo,  Cut- 
ler, Sheffield.  Svo.  1809 

Jltcflnp/.— Travel*  through  Scily,  Ma){ua  GrEcia,  und  EfCTpt.  By  Baron 
RiedeKl  I'nuuUted  froiu  tbe  Cennan  by  J.  R.  Fonter.  octavo. 

London  ITT9 

Rcierlnm.—The  lliitory  of  Atuetica.  By  William  Robertson,  D.D., 
Piincipat  of  the  L'mvcrsly  of  Edinburgb,  Ac.  Tbe  tenth  edidon,  la 
4  vols.  Svo.  London  IB08 

BMtiiim. — All  Euoy  lowanb  a  Natural  History  of  Wtstniorcland  and 
Cumbeiland.  Uy  Thonui  ltot»nsoa,  Hector  of  OutJiv  in  Cumber* 
laod.  Svo.  London  ITGR 

Rupi/anL — >E«uy<i  Political,  Elcooomical,  uiil  PhiloM^hical.  By  Ben].  I 
'Count  of  itumfurii  3  voU.  8vo.  London  J  800    ' 

■  ■-  lluknophical  Papcn.  By  Benjamin  Count  of  Rtunford.  Vol.  I,   j 
Svo.  London  1S0~ 

Bustea.—Tba  Natural  llhMry  at  Aleppo.   By  Aletandet  Ruuell,  M.I 
The  !td  edition,  enlarged  atid  iUunralRi,  with  NotM.  by  Patrick  J 
Runell,  M.D.  and  F.K.8.  Tuo  rols.  iw.  London  ITM  1 

B'jntr. — Frxdern,  Convciilionn.  Litenr,  ct  cujuKunijue  Geiteria  .\ett  1 
Puhlica,  inter  litga  AngUa  et  alios  quoivii  Imperalorei,  licg*^  1 
Prindpea.  viil  Cunununiiaie^ab  anno  not  ad  auaum  1654.  Aoei^  f 
rune  'llioma  Itymer.  SO  rati,  fullo.  Ilolnxs'i  cd.       Lond.  IT^-U    ' 

.Vimiy.— Dictiannaire  Univcnel  de  Commerce,  d'lIiMoire  Nalurelle,  t 
dis  Aru  et  Metiers.  I'ai  Jaqua  Savaiy.  4  vob.  folio. 

■■.  LcltCTi  on  Uieece,  with  Cumpaiaiivc  Itomacki  on  tt! 

Pnntnt  Stati-,  &c.    'IranaUted  (hna  tbe  French  of  M.  Stvary. 

HciaU. — Chemical  Obncwations  and  EiperimenU  on  Air  and  Fire.  Bj 
Chariea  William  Schecle,  Member  of  tbe  Royal  Aodemy  at  Stoche  ' 
holm  i  with  a  Prebtoiy  Introduction  by  Torb«ni  BeT]|:mtuin.  Tram* 
latad  fttxn  tbe  Oerman  by  J.  R.  Former,  LL.U.,  F.R.Sl  and  &A. 
To  irbidi  areadded,  Notcaby  Rich.  Kirwan,  Eaq.  F.R.S.;  witha  L«^ 
tertobin  &oi)i  JaacphPriotley.LL.D.,  F.S.S.   Svo.  London  I T80    / 

.  The  Chemical  Eaay.  of  Charles  Willi»io  Scheele.     -        ■       -    ' 

from  the  'IVanuctioii*  of  the  Acadaay  of  fideacei  at 
With  Addition!.  Svo.  1 

A'cAirnv— Journal  de  Qiimie.    Ttr  D.  AleuDder  Schcrcr.  o 

Lripw  I79S 

SrAwlgmiu.— Antiquilnta  Triiurxet  Fullonir,  a  MUiquonin  Ta 
rum  lieliquiii  coudmc.  A  Christianu  Scboettgeoio.  Tiajevi 
Itlirnum,  apud  Gulidmum  Kroon.  lAno. 

*rvrfufr<.— Scripiores  Hei   RtiMica  Vcleres  Latini,  Cato,  Varro,  C 
.    mrlla,  &c.  J.  M.  Gei.neri.  Svob.  4io.  L^p^  1779 

Smeca,—Tbt  Fpiitle*  of  Ludia  Anovui  Seneca.    With  l*>v<t  AhdoMm 
tioni.  &c   By  Thoma.  MorcU,  D.D.  In  !>  vok  4lo.         Load.  I7M 
*"       '      ir  ObservatioiK  reUtfnK  lo  several  l^ru  of  Hartary  urf    I 


»'a 


666  LIST  OF'  WORKS  CtUOTED/ 

theLerant.  The  lecond  edition.   ByThooias  Shaw/  D.D.,  F.R.SL 
4tD.  London  1757 

Shaw. — Three  Essays  in  Artificial  Philosopb j,  or  Universal  Chemistry,  by 
Peter  Shaw,  M.D.  8vo.  London  17S1 

^— .  Essays  for  the  ImpfOTemeDt  of  Arts,  ManuAictures,  and  Com- 
merce, by  means  of  Chemistry.  Sro.  London  1761 

ABitfium.— The  American  Journal  of  Science  and  Arts.  Conducted  by 
Benjamin  Silliman,  Professor  of  Chemistry,  &c.  in  Tale  Cc^ege.  5 
vols.  8vo.  1818-SS 

ArtnuAtre.— A  Series  of  Popular  Chemical  Essays ;  containing  Instances 
of  the  Application  of  Chemistry  to  the  Art5,&c.  By  Fenwick  Sioim- 
shire,  M.D.  &c  2  vols.  iSmo.  London  1808 

SmUh,'-' An  Introduction  to  Fhysiolofncal  and  Systematical  Botany.   By 

James  Edward  Smith,  M.D.,  F.R.S.,  &c.  Svo.  London  1807 

>.  The  Ancient  and  Present  State  of  the  County  and  City  of  Cork. 

By  Charles  Smith,  M.D.  In  8  vols.  8vo.  Dublin  1774 

SmyUL — The  Effects  of  Nitrous  Vapour  in  preventing  and  destroying 
Contagion,  Sec  &c.  By  Jas.  Carmichael  Smyth,  M.D.,  F.R.S.  8vou 

Londim  1799 

Society  tf  j9(fme.*-Essay9  on  the  Spirit  of  Legislation  in  the  Encounge- 
ment  of  Agriculture,  Manufactures,  and  Commerce.  Trandated 
from  the  Original  Essays,  in  French ;  which  gained  the  Pkemiuma 
offered  by  the  Society  of  Berne  in  Switaerland.  Svo.-     London  177S 

ifl^pefr.— An  Inquiry  into  the  Causes  of  the  Errors  and  Irresnilarities  in 
ascertaining  the  Strengths  ci  Spirituous  Liquors  by  the  HydrtMneCer. 
By  William  Speer,  Assayer  of  Spirits  in  Dublin.  Svo.    London  1804 

i^wvi.— History  of  the  Royal  Society,  by  Thomas  Sprat,  Bishop  of  Ro- 
chester. 4to.  London  1667 

Spren^, — An  Introduction  to  the  Study  of  Cryptogamous  Plants.  By 
Kurt  Sprengel,  D.M.,  Professor  of  Botany  at  Halle,  &c  TVana- 
lated  from  the  German.  8vo.  London  1807 

Starke. — Letters  from  Italy.  By  Miss  Mariana  Starke.  S  volumes,  8vo. 

London  179S-8 

5kafti/«s.— The  Statutes  at  Large,  edited  by  Owen  RuflThead,  &c.  Twenty, 
two  vols.  4to.  1769-181 1 

Stqthens.— 'The  Method  and  Plain  Process  of  making  Potash ;  published 

in  consequence  of  the  Encouragement  granted  by  Parliament.  4to. 

-    By  Thomas  Stephens.  London 

StSHngJleet, — Miscellaneous  Tracts  relating  to  Natural  History,  Hus- 
bandry and  Physick;  to  which  is  added.  The  Calendar  of  Flora. 
By  Benjamin  Stillingfleet.  2d  edit.  8vo.  London  1763 

l^orch, — The  Picture  of  Fetentburgh.  From  the  German  of  Hen.  Storch, 
College  Assessor  of  the  Cabinet  in  the  Chancery  of  His  Excellency 
Count  Besborodko.  Svo.  London  1801 

St,  Pierre.^^Etudes  de  la  Nature.  Nouvelle  ^tion,  revue  et  corrig^ 
Par  Jacques  Bemardin  Henri  de  St.  Pierre.  Svo.  5  vols.  Paris  1804 

Suetonhu.'^The  Lives  of  the  First  Twelve  C«esars.  Translated  from  the 
Latin  of  C.  Suetonius  Tranquillus,  with  Annotations,  &c.  by  Alex. 
Thomson,  M.D.  Svo.  London  1796 

SwUiser. — An  Introduction  to  a  General  System  of  Hydrostaticks  and  Hy- 
drauUcks,  Philosophical  and  Phurticid.  By  Stephen  Switzer.  In  two 
vols.  4to.  with  Plates,  London  1729 

TVnord.— Traite  de  Chimie  Elementaire,  Th^rique  et  Pratique.  Par 
L  J.  Tlienard,  Membre  de  Tlnstitut  Imperial  de  France,  &c.  &c. 
4  vohi.  Svo.  Paris  1813-16 


LIST  OF  WORKS  ftUOTED. 

TkndamaH¥i. — Codci  T1icod«i>mu»,  cum  PerpetuiH  C 

Gothufrcdi.  &r.  e  (ak.  folia.  (.uplutu  ItiHS 

TAemnm. — A  Sysutn  of  Chemiary,  in  4  voln.    By  Tbonui  'IlioinKin, 

M.D,,  F.R.3.  kc.  The  fifth  edit.  Svo.  Luodon  ISIT 

■ .  Atiiuii  of  Philowphy,  or  Miguinc  of  ChcmiiDT,  Minenttogr, 

&c.    By  Thoraas  Thomson.  M.D.,V.ll.S.ic.  8»o.  10  voli. 

ThomI« 

a  1B04 

TkucydiiUi. — Tlie  Miilor?  of  the  CrecUn  W«r,  in  eight  Bnoki.  Wiiltea 
^  'llmcTdidn.  Trannlitwl  by  Thomu  Hobbes  of  Malmibury.  Th» 
3d  edition,  in  2  vub.  Bfu.  London  1 733 

Ilmtf.— A  Viow  of  the  Ruwiui  Eni|iire.  to  the  clo»  of  the  PreiCDt  Cen- 
tury. By  WUliim  Toofce.  V.  ILS.  In  3  vols.  Svo.  London  1799 

TraHKKliant. — 'IVansadion)  of  the  Sodety  tnitituted  U  London  for  the 
Eneouragnnuiit  of  Arts,  MiinufACtum,  aod  Commerec.  Svo.  forty 
volunm.  idndon  ITSfl-lSSS 

u  of  the  Royd  Society  of  EJinburgh.  9  voU.  Ito. 
Edinburgh  ITSH-lSUt 

.  Truuactiani  of  thu  linnean  Sodaj.    13  vola.  quarto. 

London  IT9M833 

. .  Tnnuctions  of  llie  Society  of  the   Antiquariei  of  Scotland. 

vol.  L  llo.  Edinburgh  1799 

.  Tnumctioni  of  (he  Royal  Iridi  Academy,  12  voIl  4to> 

Dublin  17B7-ISI5 

■   TransactioDS  of  the  Arocrican  Philoaophical  Society-   quarin. 

G  vobk  Philadelphia  1TS9-1804 

.  IVanutetioui  of  tbe  Amcricaa  PbiloMFphical  Society,  New  Se. 

lie*, vol.  i.  4lo.  I'hiladelphia  IStS 

.  'nanuciiom  oTitie  Geological  Society,  established  Kovembcr 

13th,   1B07.    In  5  vol  UUU9  4to.  with  iicpanie  Volume*  of  the  I>lati«. 
Lotidon  IBIl-ig 

.  Tianiactlons  of  tlic  Royal  Geological  Society  of  Cornwall,  jiu 

stilutcd  Feb.  1  llh,  ISM.  vol.  i.  Svo.  London  181S 

Trail. — Letters  on  Icelamli  canlaininf;  Obaervationi  on  the  Cinl,  lAte- 
rary,  atul  Natiiial  History,  Antiquilie*,  Voleaaoea,  Baaltea,  Hot 
(^ngs,  &c.  made  during  a  Voyage  undertaken  in  Iba  Yaar  1778, 
by  Sir  Joseph  Batifco,  Bart.  F.R.8.  j  aMisledby  Dr.  Solander.  F.R.S. 
and  cevnal  other  literary  Ccntlcmco.  Written  by  Uno  Von  Tral, 
D.D.  e*o.  London  ITSO 

Tunu-r. — An  Account  of  an  Embaisy  to  the  Coun  of  the  Ttshoo  Lwna  in 
Tibet.  By  Captain  Samuel  Turner  1  Willi  Minenilogical  Obserratioai 
by  Robert  Saundm.  4ta.  London  IB06 

Timnitei/. Dairying  eicniplifled ;  or,  Tlie  BuMDm  of  rhnim  iinllng 

digtsled  under  vaiioui  Uestb.     I)y  Jouah  Tminley.   octaio. 

Warwick  1784 

(jn._ A  Dictionary  of  Chemistiy,  on  the  Bads  of  Mr.  Nicholson's  Ac. 

By  Andrew  LVe.  M.D.,    I'nirniW  of  the  AnderMnian   Institution, 

Member  af  the  Geological  Society,  &c.  Svo.  London  I  S3 1 

Valmigin. A  Treatise  on  Diet,  or  the  Management  of  Human  life.   By 

Francin  do  VaUngin,  M.D.  Svu.  HfiS 

I'lilnUia. — Voya|{nand  Travels  in  India,  Cejion.  ihe  Reil  Sea,  Ac.  lly 
George  ViKounl  Valaalia.  In  3  vola.  4lu.  Ltmdon  IHW 


668  hin  OF  WORKS  ayoTsp. 

Vdaiut  Flaeeui.'^C,  Vilerii  Flaod  Argonauticon  Libri  octo,  cum  NoCb 
▼■riorum,  cunmte  Petro  Bunnamio.  4Co.  Ijtadm  1794 

Fa»  Ursom.— An  aatbentic  Account  of  the  Embossj  of  the  Dutch  Eett 
India  Company  to  the  Emperor  of  China,  in  the  Yean  1794  and 
1795.  Tranalaled  ftom  the  Oiigimd  of  A.  £.  Van  Braam.  InS  voli. 
8to.  JLoodon  1796 

TbiMtL^A  Description  of  the  Firat  Discoreries  of  the  ancient  Qtj  of 
HenKlea,  &c.  TVanslated  from  the  original  Italian  of  the  Mai^nii 
Don  Marcello  di  Vinuti,  by  Wickea  Skurraj.  Svo.         T«ondnn  1750 

Fip^.— >The  Georgics  of  Virgil,  transhUed  into  English  Verse  by  WiU 
liam  Sotheby,  Eeq.  F.R.a  &c  8to.  London  1800 

m  L  The  Works  of  VvgO,  in  Latinand  En^ish.  The  Enii^ish  Tkans- 
latioDS  by  the  Rev.  Christopher  Pitt  and  Rev.  Joseph  Warton.  In 
4  volumes,  Brou  London  175S 

FilrMnif.— The  Architecture  of  M.  A^trurius  PoUio,  translated  frun  the 
Latin  by  Wm.  Newtoiiy  Architect.  3  vols.  foL     Loud.  1791 


ITolltfr.— -  An  Account  of  some  remarkable  IKscoveries  in  the  Production 
of  artificial  Cold,  &c.  By  Richard  Walker.  8to.  OxHord  1796 

IFa8if.^-The  Natural  History  and  Andquities  of  Northumberland,  &c. 
In  8  Tols.  4to.  By  John  Wallis,  A.M.  London  1769 

ITo^pofe.— The  Works  of  Horace  Walpole,  Earl  of  Orford.  In  five  toIs. 
4to.  London  179a 

.  Anecdotes  of  Paintinc  in  England ;  with  some  Account  of  the 
Principal  Artists,  and  Incidental  Notes  on  other  Arts.  Collected  by 
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The  Sd  edition,  in  5  Tolumes  Svo.  London  1782 

ITobti^AaOT.— Histona  Breris  Thonue  Walsingham,  ah  Edvardo  JMno 
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ITonl.— The  Young  Mathematician's  Guide.  By  John  Ward.  Sto. 

London  1771 

yotfofi.— Chemical  Essays.  By  R.  Watson,  D.D.,  F.R.&,  and  R^his 
IVofessor  of  Divinity  in  the  University  of  Cambridge.  The  5th  edit. 
In  5  vols.  London  1789 

Wedgwood,'— A  Catalogue  of  Cameos,  Intaglios,  &c.  By  Josiah  Wedg- 
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JFdZf.— -An  Essay  on  Dew,  and  the  several  Appearances  connected  with  it. 
By  William  Charles  Wells,  M.D.  and  F.R.SS.  of  London  and  Edin. 
The  second  edition.  8vo.  London  1815 

Werner, — A  Treatise  on  the  External  Characters  of  Fossils.  By  A.  G. 
Werner,  Counsellor  of  Mines,  &c.  Translated  from  the  German  by 
Thomas  Weaver.  8vo.  Dublin  1805 

West.-^A  Guide  to  the  Lakes  in  Cumberland,  Westmoreland,  and  Lanca- 
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Willich. — The  Domestic  Encyclopaedia ;  or  A  Dictionary  of  Facts  and 
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8vo.  By  Arthur  Young.  London  1777 


671 

INDEX 

TO  BOTH  THE  VOLUMES. 


Ajw  Nollet  c 

Abich,  hU  instrumei 
»nK  water,  i 


the  cooling  of 
t,  for  comprei- 


AHIgaart,  Profestor,  ii,  19 

Abradeil  glau,  ii.  £33 

Aoulemy  e^ublishixl  by  the  Klec- 

tor  Pnlntine,  i.  4[) 

of  Sciences  of  France,  i.  4G1 

of  FrsDcc,  it*  n^artl  for  uo- 

nufacturei,  i.  4S1 
Acciilcnu  in  coal  minei,  L  138 

from  osjmuriatic  gas,  IL  Sflfl 

from  spontaneous   combus- 

UOQ,  I.  103 
Accurate  weight!  for  inking  ipeci- 

fic  graviiiL>s,  i.  034 
Acetate  of  alumina,  L  259 

a  caution  reipectine,  t.  281 

of  alumina  by  Beruiollct,  i. 


n  storing  it, 


an  observation 

i.271 

of  boryles,  i.  345 

of  babies,  procesi  for  pre- 
paring, i.  3io 

abetter  process  for  nuking. 


i.  346 


,i.  259 


of  iron,  how  prettared.  L  877 

of  iron  and  aJumina,  L  ?77 

Aceto-citric  acid,  L  583 

Achilles  his  offering  of  a  quoh  of 

iron,  ii.  476 
Acids  necessaiy  in  all  blenching. 


Acid  and   alkali  emploved  altCT- 
nalely  in  bleaching,  ii.  £73 

acetic,  i.  346 

botctic,  L  349 

carbonic,  L  368 

dtric,  i.  a3 

muriatic,  E  453 

nitric,  i.  339 

oxalic,  ii.  23 

inroligneoui,  i.  878.  S80 

sebacic,  i.  38 

sulphuric.  L  465 

how  formed,  i.  473 


i.354. 


i.3« 


Afts  of  parliament  in  favour  of 

glass-making,  ii.  313 
respecting  glass. 


Advke  to  gardeners,  ti.  344 

respecting  the  construction 

of  water  rcserroin,  ii.  387 

Adulteration  of  liquid  substances 
not  accurately  discorered 
by  specific  gravity.  J,  SB 

Adulterations  of  iemon-juice  hoir 
detected,  i.  5S6 

Aeronaut,  his  use  of  sulphuric 
acid.  i.  SSO 

Affinities  altered  by  change  of  tem- 
perature, i.  117 

Aficlius  on  analysing  sulphate  of 
barytes  i.  315 

Agate,  collections  of.  i.  4S5 

Agatiicd  wood  at  Dclgradc,  i.  435 

Agricota  on  glaM,  ii.  167 

on  the  use  of  nitre  in  glass, 

ii.  £50 

AgriculWuT  improved  by  Ch^mifc 


672 


Il^DEX. 


Mr,  heated,  its  effect  on  the  body, 

L71 
breathed  by  Sir  Joseph  Banks, 

&c.  1.  71 
— —  the  effect  of  a  sheet  of,  L 
144 

■  its   property    of   defending 

from  cold,  i.  143 
— ^-  and  water  act  reciprocally  on 

each  other,  ii.  411 
Alabaster-tomb  of  the  Duke  of 

Brittany,  il  88 
Albany  river,  i.  55^ 
Albettus  Magnus,  ii.  6 
Alcuraias  manufiu:tured  in  Spain, 

i.  108 
Alchemists  of  Europe,  L  4 
,  a  proclamation  respecting, 

i.606 
Alchemy,  attempt  at  its  reviral, 

i.  G06 
Alcohol  of  sulphur,  i.  390 
-»— -in  boming  produces  water, 

ii.  309 
Alkali,  origin  of  the  word,  ii.  6 
^— ^  minml,  home  preparatian 

of,  i,  191 
— *-  nature  of  its  action  in  bleach- 
ing, iL  309 
— :—  proper  for  plate  plass,  it.  214 
— »-  Its  use  in  bleaching,  ii.  s?72* 

309 

—  caustic  in  calico-printings  L 

263 

■  the  temperature  of  its  eva- 

poration when  melted,  ii. 

194 
Alkalies,  fixed,  their   character, 

ii.  3 
— -  three  species  of,  \k  4 
— —  antiquity  of  their  use,  iL  5 
— —  known  to  Aristotle,  ii.  5 
--^—  their  peculiar  taste,  ii.  7 
their    effect    on    vegetable 

juices,  ii.  8 

■  of  great  use  in  dyeing,  ii.  9 

—  employed  in  soap  and  glass, 

ii.9 

—  mode  of  their  preparation  for 

soap,  iL  10 

how  rendered  caustic,  ii.  10 

— —  the  economy  of  using  them 

caustic,  ii.  12.  584 


Alkalies,  siud  to  be  prodaced  by 

fire,  ii.  15 
■  ■        chemical  tests  for,  ii.  8 

how  distinguished,  ii.  4. 46 

imperishable  by  age,  iL  40 

*—  manufacture  of,  i.  191 

■  the  chief  consumptioo  o^ 

iL9 
— •—  combine  with  diflfereot  por- 
tions of  acid,  ii.  45 
—— i-  fixed,  certain  differences  in, 

ii.  47 
—  their  change  by  carbonic  acid 

first  explained  by  Dr.  Black, 

ii.9 
— -» their  compound  nature,  iL  58 
rough,  their  improvement  by 

age  explained,  iL  40 
fixed,  their  corrosive  nature^ 

ii.583 

■  directions  for  examiniiig  the 

state  of  their  caottidty,  i. 
584 

directions  for  preparing  them 

in  a  state  or  purity,  ii.  585 

■  decomposed  by   &t  Hum- 

phry Davy,  ii.  59 
a  nistory  of'^their  fest 

position,  ii.  59 
the  proportions  of  their 

and  oxygen,  iL  64 
Alkaline  sulphates  decomposed  by 

barytes,  i.  361 
materials,  necessi^  of  ana- 
lysing for  glass,  ii.  206 
Allen  and  Pepys  on  the  formatioo 

of  charcoal,  i.  409 
Alloy  of  platinum  and  silver,  L  224« 

ii.  543 
-~—  of  platinum  and  iron,  L  284 

of  tin  and  copper,  i.  224 

— — -  of  mercury  and  barium,  L 

356 

of  iron  and  potassium,  L  428* 

of  potassium  and  sodium, 

n.  66 

of  steel  and  platinum,  ii.r54S 

—  of  steel  with  silver,  iL  543 
— -  of  steel  with  silver  valuable 

for  making  dies,  ii.  545 

of  gold  with  sted,  «,  545 

Alleys  of  sted  with  rfaodiom,  ii* 

544 


AUoji  of  mmI  and  platinum  re* 

marlcably  aSected  by  ac!ds, 

;i.  546 
of  iron  lera  lubiect  to  oxida- 
tion than  ulloys  of  tted, 

!i.546 

of  iron  and  iridium,  ii.  S4S 

oroiDitum  and  iroD  niit  with 

ttifficultjr,  u.  548 
metsliic,  ih«r  melting  pointi, 

i.  224 
Alum,  tho  fint  manutactory  or, 

i.  3G 
■        unknown  to  the  Greeki  and 

Itomans,  i.  6S5 
— -  of  the  ancients  wa*  probably 

menial  vitriol,  i.  635 
iti  mnnufacture  brought  into 

Europe,  i.  625 

an   Asiatic   aiipcretition  re- 

specting, i.  636 

when  fint  made  in  England, 

i.flS5 

English    manufactories    of, 

i.e26 
manufactory  of,  near  Rome, 

1.620 

native,  t.  S21 

Alum-stone,  i.  522 

Alum  J>ay,  the  aand  there,  ii.  SIO 

Aluniins,  pure,  to  prepare,  ii.  110 

its  aftini^  for  water,  ii.  365 

i»  loM  of  weight  by  heat, 

ii.  125 

•  and  nlica,thdr  affinity,!).  107 

Aluminous  mordant  of  India,  i.  354 
Amalgam  for  electrical  machines, 

i.  89 

of  potosiium,  ii.  63 

of  sodium,  ii.  64 

Amriih  on,  M.,  on  the  trial  for 

witchcraft    b;    meant    of 

water,  ii.  421 
America,  change  of  cUmate  in,  i.  56 
Ajneriean  potath  for  glan.ii.  249 
bark,  its  use  in  calico^riat- 

ing,  i.  305 
flmir     for    cal!co-f>rintiag, 

i.  26g 
potaih,  the  kindi  of,  diitin* 

guiihed,  ii.  1S5 

iron  «nd  mmI,  ii.  494 

VOL.  IT.  2 


X.  873 

Americuu,  ttar  sttcD^on  to  iIm 
manuftcture    of  iron  anJ 
)ieel,ii.494 
Ammonia,  its  composition,  ii.  448 

its  properties,  ii.  443  , 

produced  from  urine,  iL  4fl3 

procured  artiiicially,  ii,  44S 

from  what   aubstancet  belt    , 

procured,  ii.  446  __ 
and  muriatic  acid,  experiment 

with.  ii.  453 

its  al{iaitie«.  ii.  463 

various  writers  upon,  ii.  46&^ 

its  compound  nature esplaij^ 

cd  by  BerthoUet,  iL  443     , 

a  product  of  putrefactioii^.  j 

ii.  463 

uses  of,  ii.  445.  608 

used  as  a  cure  for  the  bite  of 

the  rattlesnake,  ii.  608 
manufacture  of,  on  the  *eft< 

coast,  ii.  459 

native  sulphate  of,  i.  522 

citrate  of,  i.  576 

subcarbonatc  of,  L  383 

Anuiioniacol   gaii    discovered     by 

Dr.  Priestley.  iL  44J 
decomposed  by  clectri* 


-  salts. 


.444 


salt,  how  made  in  Gennanj, 
iL  459 
liquor  of  the  ga»-worki,  ii. 

Ammo-nitrum  of  the  ancieoti,  iL 

245 
.\mmonius,  the  preceptor  of  PIu. 

larch,  ii.  437 

Saccas,  ii.  437 

the  preceptor  of  Simpliciiu 

ii.  437 
Amphitheatre  of  Rome.  i. 
Amphitheatres  of  Nero,  u.  258 
'  \nBgnun  of  Roger  Bacon,  L  ?"" 
inalyiis,    i'     ' 


— —  of  barilla,  A-c.  u  27 

of  carbonate  of  baryte*,  L 

of  fulleni*  earth  by  " 


-  of  Heel  bjVauqucUn,  i 


674 


INDEX. 


Anatomists,  their  employment  of 
frigoiific  mixtiffes,  L  121 

Anchors  first  made  of  stone,  iL  609 

^-—  of  wood  loaded  with  lead, 
iL609 

Andent  poipl^  i«  686 

—  walls,  n.  597 

— —  potteries  discorered  in  the 

United  States,  iL  597 
_  domestic  implements  of  cop- 
per, iL  477 
i*— -  patent  for  ^ass,  iL  182 
Andersonian  Institution,  i.  7 
Andes,  have  difoent  climates  ao- 

cortfing  to  the  eleyation,L  55 
Anecdote  of  poisoning,  L  13 
■        by  Martial,  of  a  lady  in  Rcmie, 

iL599 
—- ^  respecting  wax  for  resisting 

colours,  L  288 
of  early  Scotdi  bleaching, 

n.269 
of  a  bleacher  of  anUquity, 

iL338 
respecting  private  bleaching, 

iLd91 

— >—  of  a  Roman  architect,  n.  170 
Anecdotes  respecting  the  bladL- 

lead  mine,  L  440 
Anglezark  lead  mine,  i.  321 
•^—  the  author'svisit  to  this  mine* 

L324 
— — -  its  present  state  described, 

L326 

—  visited  by  Frenchmen,  L  327 

—  account  of  several  occur- 

rences there,  L  328 

—  inquiry  respecting,  further 

prosecuted,  L  330 
Animal  heat,  L  68 

heat,  the  same  in  all  climates, 
L6d 

heat,  contrivance  for  modi- 
fying, L71 

temperament,  its  uniformity, 
L74 

heat,  production  of,  L  614 

heat,  preservation  of,  L  614 

food,  prepared  by  freezing, 
L116 

bonef  used  as  a  manure  in 
China,  iL  609 


Animal  charcoal,  L  412L  n.  515 

—  charcoal  for  hardmiag  Mei, 

S.515 
■    food,  an  expedient  for  pre- 
tervii^  L418 

—  heat,    SrawfonPs     rzperi- 

mcntson,L65 
and  vegetable  charcoal,  how 

^stinunnshed,  L  414 
Animals,  difoent  mecbanism  o( 

L63 
their  power   of  produd^g 

cold,  L  73 

Annealing  fornaoe  of  the  ^aM- 
hoose^iL  187 

»—  cast  cudeiy,  iL  540 

ofglass,iL219_ 

— — —  of  crown  ^ass,  S.  199 

plate  glass*  iL  233 

ovens  for  cast  (JatedaM,n.  8S8 

Anomalies  in  the  fusibin^  of  dm- 
tallic  compounds,  i.  223 

in  the  rodting  pobila  of  ma- 
tures of  lead  and  tin,L  2S4 

Anthony  de  Brossafd,  sIms  home 
of,  iL  177 

Antliracoiite,  L  447 

Anti-attntioD  pnrte^  its  oob^mhk 

tion,  i.437 
Antimoniate  of  barytes,  L  348 
Antimonite  of  barytes,  L  348 
Antimony,  a  case  of  poisoning  hf, 

used  bjr  the  potters,  5.  596 

Andquity  of  chamag  stakes,  L  425 
Anti-septic  quality  m  hard  water, 

ii.388 
Anvil,  a  peculiar  one  for  scissar^ 

ii.497 
Apartments,  how  cooled  in  India, 

L108 
Apothecaries'  Company  ofLondon, 

their  laboratory,  ii.  605 
Apparatus,  galvanic,  i.  90 
— — >  employed  in  fireezing  water, 

L123 

glas8,for  burning  sulphur,L474 

— ^  for  squeezing  day  at  Etruria, 

u.  117 

for  drying  calicoes,  described, 

L272 

—  for  freezing  mercury,  L  123 


Apparatui,  new  one,  for  buniDg 
the  iliamonil,  i.  SOS 

for  making  churcoul,].  3&6 

^—  for  extracting  ihe  caluur  of 
dye-wood,  1.  4 IB 

for  making  crowu  ctau,  u. 

191 

for  hacking  linen,  iL  371 

for  bleaching  byitcaDi,ii.33(! 

for  the  compression  of  water. 


453 

~  at  Apo^iccarics'  Hiill.fiill  de~ 
scription  of,  ii.  605 

Apuldus,  nil  anecdote  on  bleach- 
ing by  stdpbur,  iL  338 

Aquafortii  recommcuded  by  Rcau- 
ir  for  tempering  fikea,  ii. 


517 


It  Burstall,  i.  2d 


slico-pnnten, 
i.  278 

carboys  of  gla>$  for,  ii.  304 

Aquatic  v<9cla1ilcs,  their  ctlect  in 
punfj-ing  water,  iL  SSS 

Arabian  mravans,  their  mode  of 
cooling  water,  i.  109 

Arabs,  account  of  their  saiis,  i.  345 

Archimedes,  i.  5.  85.  201 

set  fire  to  the  ships  of  the 

nomaiis,  i.  85 

how  ho  found  the  spociSc 

gravity  of  gold,  L  221 

the  use  of  tnis  piece  of  ht»- 

tory,  i.  3i8 

his  error  explained,  i.  324 

his  De  ialidcntibm  hunido,  i. 

201 

— —  his  method  of  determining 
metallic  alloys  by  their  spe- 
cific j^Tity   fallacious,   i. 


Architect,  an  caiinent  Roman,  bn- 
niihed  for  his  popularity, 
iL  170 

Architeoi  of  Rome  not  allowed  to 
affix  their  names  on  build- 
ings, ii.  &01 

Areometer,  L  illB 


ix.  676 

Areometer    fur    fluids  described, 

LCO!) 
for  solids,  i.  SIO 

—  BBUin6's,for  soils,  L  218 

how  prepared  by  him,  i.  811 

a  term  employed  by  Hom- 

bei^.L^IO 

forspiHis,L8I3 

Arfvredson,  M.,  of  Sweden,  iL  66 

Argol,  iL  34 

Armour  of  the  Anglo-Snxons,  iL 

■IH3 

—  '  of  the  ancient  Normans,  ii, 

of  the  nncient  Dritish,  ii.  483 

of  thcEarl  of  Douglas,  ii.  484 

Aroma  of  the  bop,  how  preserved, 

L175 
Arrangements  necessary  for  mak- 
ing dtric  acid,  i.  543 
Arrows  of  the  English  in  1 408,  ii. 

484 
Arsenic,  its  use  in  glass,  ii.  IDO 

the  difficulty  of  combining  it 

with  lead,  iL  190 
Arseniate  of  barytcs,  L  348 
Arscnitc  of  bai^tes,  i.  318 
Artificers  in  iron  in  crcot  eslim^ 
tion  formerly,  li.  4fi3 

of  Mnrano    ennobled    by 

Henry  III.,  Li.  177 
Arum  maculatum,  ii.  263 
contiuns  a  largo 

portion  ofheat,L614 
Asbestos  fused  by  Ilolfman,  i,  f(4 
Ashing  in  calico-printing,  L  863 
Ash-pit  doors,  i.  155 

-  better  than  registers. 


L  150 

Asiatic  porcelain,  places  of  its  ma- 
nufacture, li.  84 

Astley,  Mr.,  his  patent  for  sal- 
ammoniac,  iL  456 

Atmosphere,  its  use  in  prcsorving 
the  warmth  of  the  earth, 
i.  140 

Atmospheric  air,  inhalation  of,  i.65 

Atomic  system,  L  3H4 

Attrnclion.  double  elective,  li.  44S 

Attrition,  experiments  on,  i,  M 

Atigco,  gouges  and  ctus^  how 
mode,  ii.  4W 
x2 


676 


INDEX. 


Aulus  GeUiiu,  i.  466 

Ausdiiy  Dr^  on  the  formation  of 

ammonia,  iL  446 
Authors,  a  list  of,  on  hydrostadct^ 

L218 
Axes,  how  made,  iL  495 
Ayoree,  the  white  earth  of,  ii.  107 

B. 

Bacon,  Roger,  the  discoverer  of 

gunpowder,  i.  193 
— ^->  Francb,  L6nl  Chancellor,  L 

4.41 
■  his  process  of  fineezing 

water,  I.  119 

the  first  rational  expe- 


rimentalist, L  4 
—  his  anagram  for  describ- 
ing gunpowder,  L  393 
Chemistry  peculiarly  in- 


debted to  him,  i.  4 

—  his  character,  L  606 

—  the  first  writer  who  re- 
commended a  mixture  of 
snow  and  salt  for  fineexing 
water,!.  119 

—  on   spedfic  gravity,   i 


20^ 


V  and  Boyle  on  the  ex- 

pansion of  water,  iL  415 

Bagging  of  oil,  u  182 

BaEer,  Sir  George,  on  the  poison 
of  lead,  it  410 

Balance,  the  antiauity  of,  i.  201 
i   '  directions    tor   choosmg;  i. 
207 

Baldwin's  phosphorus,  i.  128 

Ballast  for  ships,  i.  16 

Bancroft  on  permanent  colours,  L 
19 

<— —  Dr.,  his  experiments  on  log- 
wood, ii.  402 

Bandana  handkerchiefs,  L  288 

Bands  for  furnaces,  L  167 

Banks,  Sir  Joseph,  his  experiments 
on  respiration,  i.  71 

Barberini  or  Portland  vase,  ii.  85 

Barberry  punch,  i.  573 

Barclay's  Argenis,  some  account 
of,  i.  121 

Barilla,  ii.  37  . 


Barilla  imported  firom  Spain,  iL  9 

its  manufiurture,  iL  39 

-—  and  kelptdiffisrence  of,  iL  39 
■    directions  £o^  analysts  o(  n. 

41 
employed  for  crown  gla«,  it. 

192 
— —  the  finest  Spanish,  sent  to 

P&ris,ii.584 
Bar-iron,  its  difovooe  from  cast 

iron,  iL535 
-^—  for  tin-plate  prepared  with 

charcoal,  iL  554 
Barium,  L  334 

how  obtamed,  L  356 

chloride  o(  i.  342 

— ^  oxide  o(  L  334 
Baroselenite,  L  314 

analys^  by  Kli4>rotb,  L  631 

Barrow,  curious  account  of  the 

opening  of  one  in 

ii.610 
Bartholdus  Schwaitx,  L  394 
Bartholin  on  the  mrdirinal 

of  snow,  L  112 
Baiytes,  enajron,  L  313 
— —  its  orfgmal  names,  L  313 
■  difi^ent  chemists  who  have 

treated  of  it,  L  323 

—  its  action  on  the  stomach  of 

animals,  L  331 

how  obtained  pure,  L  333 

hydrate  of,  L  335 

three  hydrates  of,  L  336 

its  peculiar  properties,  ip  336 

nitrate  of,  L  338 

muriate  oii  i.  341 

—  citrate  of,  L  576 
sulphate  of,  L  633 

the  facility  of  its  ciyttallisa> 

tion,  L  342 
-— —  and  strontites,  their  resen* 

blance,  L  343 
— —  gives  a  yellow  colour  to  flame^ 

L344 

—  how  best  preserved,  L  344 

—  acetate  ot,  i.  345 

pure^  preparation  oC  L  634 

«—»  bow  procured  by  Pdleticri 

«—  a  process  for  the  preparatioo 
of,  L  319 


INDEX. 


677 


Bnrytes,  a  French  process  for  pre- 
paring, i.  319 

——  used  in  the  manufacture  of 
jasper  pottery,  ii.  162 

—  and  strontitcs,  difference  be- 

tween, i.  343.  633 
-T—  its  solubih'ty  in  water,  i.  344- 

—  for  the  arts,  how  to  be  pre- 

pared, i.  361 

—  decomposed  by  Sir  II.  Davy, 

i.  :^6 

remarks  on  its  uses,  i.  358 

—  proposals  for  experiments  on, 

in  making  pottery,  ii.  16:^ 
'      an  agent  for  purifying  water, 
ii.  389 

—  singular   circumstances   re- 

specting its  medicinal  use, 

i.359 
Bar}'tic  salts  poisonous,  i.  331 
-f-—  poison,  nature  of,  i.  331 
— ^  crystals,  i.  335 

—  cements,  i.  360 

—  water,  i.  344 

—  chemical  tests,  L  338 
Basalt,  Sir  James  Hall's  experi- 
ments on,  i.  189 

■        employed  in  glass-making, 

i.  189 
Basil  Valentine,  i.  466 
Baton  of  ice,  filled  with  ¥rine,  i.  1 21 
Basso-relievos  formed  in  running 

water,  ii.  430 
Baths  of  St.  Philip,  ii.  430 

—  for  tempering  steel,  ii.  520 
Batteries,  electrical,  i.  8!) 
Battle  of  Hamildon  in  1402,  ii.  484 
Baume  on  clay,  ii.  103 

—  on  bliNiching  silk,  ii.  339 

his  areometer,  i.  209 

for  salts,  i.  212 

— — —  for  spirits,  i.  213 
»— manufacture  of  sal-anunoniac, 

ii.  458 
Bayonets,  French  manufacture  of, 

i.  483 
Bay-salt,  foreign,  ii.  591 
B^ik-irons  or  Bickerns,  ii.  498 
Beaumont  on  the  coal-damp,  i.  97 
Beckmann  on  writing  upon  glass, 

ii.220 
-«-^  on  the  antiquity  of  sal-am- 
moniac, ii.  608 


Beddoes,  Dr.,  on  frigorific  mix* 
tures,  i.  125 

Beds  of  retorts,  for  oil  of  vitriol^ 
1.533 

Bellain^,  Count  dc,  ii.  289 

— — —  his  efforts  in  the  art  of  gas- 
bleaching,  ii.  288 

BeU-metal,  its  specific  gravitj, 
i.  224 

Belzoni,  Mons.,  his  account  of 
Eg^-ptian  pottery,  ii.  593 

Benzoate  of  bar}'tes,  i.  349 

Bergman  on  brick-making,  ii.  87 

—  on  elective  attraction,  ii.  448 

—  on  the  earth  of  gems,  ii.  167 

on  mineral  water,  ii.  370 

his   analysis   of    sea-water, 

ii.  463 

Berlin-china,  the  exertions  of  the 
king  to  encourage  its  ma- 
nufacture, ii.  131 

Bernard  de  PaKssy,  ii.  593 

Berthier  on  the  alloy  of  chromium 
¥rith  steel,  ii.  547 

Berthollet  on  the  dung  of  the  cow, 
i.  275 

his  obscn'ations  on  madder, 

i.  283 

on  decomposition  of  oil,  i.378 

—  on  dew,  ii.  266 

■  first  employed  chlorine  in 
bleaching,  ii.  276 

his  memoir  on  bleaching, 

ii.  286 

—  his  materials  for  bleaching, 

ii.  287 

— *—  his  difficulties  in  gas  bleach- 
ing, ii.  288 

some    remarks  of   his   oa 

bleaching,  iL  298 

— —  and  Watt  on  the  indigo  test, 
ii.  334 

Beunie,  Mons.,  on  soils,  i.  9 

Billets  of  wood  agatized,  L  426 

Binffley*s  patent  piano-irons,  ii.49S 

Birds,  how  preserved  at  Hudson's 
Bay,  i.  142 

Birds-cherry,  produces  citric  add, 
i.  572 

its  infusion  in  wine,  &c. 

i.572 

Biscuit-ware  of  the  potter  de- 
scribed, iL  126 


678 


INDEX. 


Biscuit-ware,  method  of  painting 

on,  iL  14£ 
Binmithy  citrate  of,  i.  576 
Bistre,  its  preparation,  L  413 
Bittern  of  salt-works,  iL  455 
-^— why  so  proper  for  making 

sal-emmoniac,  ii.  464 
7>-~  in  Scotland,  allowed  free  of 

duty,  iL  456 
Black,  Dr^  his  chemical  lectures, 

L6 

his  theory  of  latent  heat,  L  7 

-»—  his  discovery  of  latent  heat, 

L64 
— ««  on  breathing,  L  141 
■        on  chimneys,  L  170 
— -—  discovery  of  carbonic  add, 

L369 
<— —  on  the  consumption  of  smoke, 

L170 
— —  his  discovery  respecting  the 

alkalies,  iL  9 
-■       on  alkaline  carbonates^  iL  9 
Black  produced  by  iron  and  mad- 
der, L  280 
Black-ash,  L  37 
*-'—  preparation  of,  i.  612 
Blacks,   now  dyed    on  calicoes, 

L278 
Black-lead  mine  in  Borrowdale, 

when  discovered,  i.  440 

■  method  of  securing, 

L442 
— —  pencils  first  made,  L  433 

—  expense  of  procuring,  i.  445 

—  value  of  the  mine,  L  445 

—  quantity  raised  at  Borrow- 

dale, 1.  445 

—  its  prices,  i.  446 

—  names  of  the  proprietors  of 

the  mine  of,  i.  446 
^—-  annual  consumption  of,  i.  446 
Blacksmith,  his  expedient  for  pro- 
ducing fire,  i.  102 
Blagden,  on  the  freezing  of  mcr- 
cuT}',  i.  68 

—  his  experiments  on  heat,L  72 
Blake,  Mr.  John  Bradley,  his  at- 
tempts to  improve  pottery, 
iL  126 

Blancourt,his  account  of  malleable 

glass,  ii.  171 
Blazing,  saws,  process  of,  ii.  514 


Bleachers'  residuuiii,  of  use  in  gar- 
denings ii.  344 

^—  residuum  efiectual  in  pre- 
venting infectious  fever,  n. 
345 

waste  lyes,  u.  ^7 

— *—  method  of  regenentiiK^ 
iL347 

Bleachers,  how  regulated  in  Ire- 
lam^  iL  330 

Bleaching,a  chemical  nroccsi^  L  21 
an  essay  on,  IL  257 
r,i.38.    11.339 


pimer, 
caucof 


icoes,L261 
the  goodness  o^  proved,  L 

265 

of  the  ancient  Britons,  iL  259 

proundi  at  Haarlem,  iL  264 

Its  introduction  in  Sootlancl^ 

iL269 

—  the  old  process  tedious,  iL 

273.  329 

with  sour  milk,  iL  £75 

at  Nottin^mm,  iL  &0 

apparatus  of  the  printers,  iL 

293 
by  gas,  its  advantages^  n.  296 

—  thedifierence  of  waste  in^  iL 

298 

the  modem  process  of,iL  309 

•^— -  by  chloride  of  potash,  n.  304 

liauor  for  hose,  iL  307 

calicoes  for  the  printer,  ii, 

312 

questions  concermng,  iL  322 

hints  for  improving  the  art 

of,  u.  322 

of  wool,  ii.  337 

bees  wax,  ii.  338 

of  straw,  ii.  340 

liquid,  test  for,  ii.  345 

■         vessels,  iL  346 

—  a  test  for,  proposed,  iL  350 
treatises  on,  ii.  351 

liquor  for  private  fiunilies,iL 

290 

Bleach-works  must  not  be  esta- 
blished in  some  districts, 
ii.376 

Block.cutting,  i.  268 

—  printing  of  calicoes,  L  267 
tin  prepared  from  tin-slone^ 

ii.  561 


^^^^^^^^^^^H 

INDEX.                                             679 

Borate  of  bor)tei.i.  349 

i.  13 

copadty  of,  for  ctloric,  i.  G4 

elus.  iL  246 
employed  by  Dr.  Shaw  ia 

arterial  and  venous,  i.  66 

making  pla».ii.a51 

^—  the  colour  of,  L  608 

known  to  the  ancients,  ii.250 

its  cliangc  of  colour,  L  67 

Boring  of  copper  cylinders,  i.  307 

Bluc-primingorihe  potter,  ii.  H3 

of,  i.  434 

BoBwell,  on  watering  ineadowi,  ii. 

ihcglaM  employed  for.ii.H? 

43» 

Dottie  glass,  i.  189 

vat.  art  of  mBldnr.  i.  2«5 

iHcthotJ  of  rcpleiiijlung,  L 

manufacture  of,  ii.  SOS 

materials  for,  ii.  203 

itW 

method  of  &shioning.  i),  £04 

BlueJ  steel,  curiom  properties  of. 

apeculiar  kind  made  atNcw- 

ii.510 

castle,  ii.  306 

Boots  oftbe  ancient  Egrptinna,  ii .  "7 

Bounties  on  the  export  of  manu. 

Boitilr  [cnipcrature,  how  prescrv- 

racturodj;oods,i.459 

eel.  1.  141 

Bourbollon  do  HonnucSI,  ii.  2SZ 

Bovcy  eoaJ,  i.  435 

Bow  china,  ii.  131 

mistry  to  medicine,  i.  1 1 

Boyle,  Mr.,  ht>  treatise  oo  cold. 

on  vineenr-malunB,  L  33 

on  water,  ii.  433 

i.  114 

on  the  purification  of  water 

cold,  LI  19 

under  tlie  equator,  ii.  408 

Duilcn,  remarki  on  scHing,  i.  159 

on  the  nnifiml  production 

of  cold,  LIU 

of  briclc,  for  coop,  i.  1 69 

•^—  on  the  freeiins  of  animal 

BoUing,  theory  of,!.  74 

food,!.  117                                         J 

his  citpcdient  for  frecrinc  th« 

water,      conv^cd     under 

ground,  i,  140 

hunioursofthecye.  i.  131 

his  syphon  of  ice,  i.  ISO 

nolciMeofbarytc8,i.349 

on  specific  gravity,  i.  202 

Boletic  acid,  i.  349 

on  procuring  frt^)  water  U 

Doictu«  pscudo  iuniariu*.  L  349. 

sci,  ii.  406 

m.  iL  24 

B«h^Tj<:ho,L7 

Dologna  .lones;  i.  310 

Bmmuli's    press    employed     by 

bleachers,  iL  311) 

scribed,  i.  6«3 

Bronde,    \fr.  Professor,    on  Uw 

Uombaiinc  prcssea,   an  improve- 

blood, i.  13 

ment  in  them  «iigee>U-d.  i. 
623 

his  cxucriment*  on  cnrbu. 

retted  hydropsn  gas,  L  370 

Dunes,  aaima],  analy^  of^  ii- 134 

■  injurioui  toporcclaio,  ii.  135 

--^  employed  id  pottery,  ii.  134 
di&tiUatiou  of,  for  Muooiua, 

on  iho  economy  of  go*  iIId- 

minntlon.  L  3?? 

U.4&0 

Bone  >i>irit,  a.  4,^1 

3!ll 

Elonjnnr,  Mr.,  «  l-Verxh  Ulcacbrr, 

mi  the  "nnh-is  of  pluinbi>i(t>. 

ii.  28S 

i,  4.14 

1 

^80 


INDEX. 


Brande,  Mr.  Professor,  on  the  coal 

formation,  i.  453 
■■■  ■     on  the  analysis  of  Chdten- 

ham  water,  L  528 
.Ai— •  on  the  chemical  apparatnv  at 

Apothecaries'  HaU,  ii.  605 
Brandies,  how  purified,  L  419 
Bnnning  of  calicoes,  i.  2S2 
Brass  introduction  of,  i.  36 

■  ■      manufacture  of,  i.  61 1 
Breedon  limestone,  L  10 
Breweries,  i.  175 

Brewing  fermented  liquors,  L  31 
Brewster,  Dr.,  on  Mr.  Stodart's 

alloys  of  steel,  ii.  546 
Brice,  on  hydraulic  oi^gans,  ii.  4i20 
Bricks^  their  antiquity,  IL  74 
— —  on  the  choice  of,  L  164 
•—  process  of  burning,  ii.  87 
——  of  fossil  meal  float  in  water, 
ii.  161 
■  bad   conductors   of 

heat,  n.  162 
Bricklayer,  on  the  choice  of,  L 152. 

164 
Brick-making,  an  art  of  great  con* 
sequence  among  the  Ro- 
mans, iL  591 
Brid^ofTra[an,L4£5 
Brilliants,  their  value,  i.  367 
Brimston»4tove  for  hose,  ii.  310 
Britain,  observations  on  the  trade 

of,  ii.  468 
British  IskeSf  proposal  respecting, 

1.58 
— —  manufactures,  their  preemi- 
nence, i.  194 
—  gum,  i.  269 

■  manufacture  of^  describ- 
ed, i.  629 

a  large  quantity  of,  seiz- 


ed by  the  Excise,  i.  630 

Broad-glass,  ii.  200 

Brodie,  Mr.,  his  objection  to 
Crawford's  theory,  i.  68 

Bmce,  his  opinion  respecting  the 
purple  of  Tyre,  i.  626 

Brugnatelli's  method  of  preserving 
citric  acid,  i.  541 

Brussels,  industry  of  its  inhabi- 
tants, i.  457 

Buchanan  on  heat,  i.  145 

Bucking,  a  technical  term,  ii.  271 


Buddie's  report  on  the  safety  lamp, 

i.  137 
BuQbn,  some  account  of,  L  204 

—  his  singular  notion  reelecting 

the  temperature  of  the  pla- 
nets, i.  52 
— r~  his  combination  of  bumtng 

mirrors,  i.  86 
— —  on  climate,  i.  52 
on  the  specific    gravity  of 

minerals,  i.  204 
— —  his  crude  notion  of  siHca,  n. 

103 
Bulbs  for  ascertaining  the  weight 

of  fluids,  L  236 
Buonaparte,  medallions  of,  in  Cry- 

staOfhCerame,  iL  233 
Burning  mirror,  an  economical  use 

of,  i.  87 
Burnt  bone,  its  use  in  pottery, 

ii.  134 
Bussy,  on  purification  by  diarcoal, 

L421 
Butter-milk     forraeriy    used    in 

bleaching,  iL  £08 

C. 

Caesar,  Julius,  i.  6 

Calcination  of  the  materials  for 

bottle  glass,  ii.  205    ' 
Calendering  calicoes,  i.  267 
Calico-printers  require  pure  water, 

iL375 

—  souring  L  266 
Calico-printmg,  i.  241 
chemical,  L  18 

—  improvements  in,  L  20 

in  Great  Britain,  i.  258 

in  India,  L  253 

modem  practice  of,  in  India, 

L255 

surface  machines,  i.  307 

Calicoes,  dressing  of,  i.  262 

—  mode  of  printing,  i.  267 

—  for  printing,  how  bleached, 

ii.  312 
Caloric,  its  distribution,  i.  51 
how  distributed  by  the  blood, 

L66 
capacity  for,  L  63.  614 

—  free  and  latent,  i.  64 

—  conducting  of,  L  145 


ISDKX.                                        ()8I                 J 

Cimpbell.  Dr.  John,  on  the  wattn 

Coat-iron,  cutlery,  how  conrerted 

of  Great  Rritaia,  U.  3n9 

to  steel,  ii.  639 

Dr  H  .  hit  method  a(  ii»- 

Cait-iron    goods   c<>nrerted    into 

wroiiKt>tironor>t»l,ii.64t 

Cast-iron  tinned,  ii.  553 

CandJai,  mBnuficlure  of,  i.  i'!> 

Cast-nails  made  flexible,  ii.  fill 

how  belt  preierTed,  i.  29 

Caxtptaic  glass,  how  mHde.ii  231 

Cunel  oial.  i.  447 

Caitiog  of  plate   gliiss   a   grand 

Cannon,  iron,  when  Grat  miide  in 

spectacle,  ii.  231 

EnjcUnd,  i.  637 
Caolon't  iih.)9phoriii,  i.  12^ 

CasUsterl,  the  making  of,   i.  15. 

ii.  <90 

Caoutchouc,   i.  466 

process  for  making,  it.  537 

C*p»dtiM   of  bodies   for  c-loric. 

difficulty  of  welding,  ii.  491 

i.  614 

foimerly  iinited  to  iron  by 

CBqucrny,  Meisrii.  de,  ohtain  the 

rivets,  ii.  493 

rifihtof  mukina  glaii,  ii.  177 
Caral  weights,  i.  22f 

how  made  in  Pemia.  il.  637 

Casta  of  medaU  and  coins,  how 

Carbon,  an  es^y  on.  i.  365 

preserved  in  glass.  Ii.  233 

iti  properties,  i,  367 

Caustic   alkali,    dreadful   effect* 

held   in  loliition  by  water. 

from,  ii.  5S3 

Q.  360 

potash  in  a  dry  slate,  direc- 

bow    separated     from    the 

blo«d.  1.  67 

lime    necessary   for    plate- 

iti  proportions  in  iron  and 

gla».  ii   211 

steel,  li.  536 

Causticity  of  ntkalies,  how   pro- 

CorboDate of  barytes,  i.  32fl.  360 

duced,  ii.   12 

it!  decomposition,  i.  353 

Caxton,  William,  iho  first  English 

^ilUcit  trade  in,  1.323 

printer,  i.  6U6 

r..rboidc  Mid,  L  368. 

Ciiylul,  Coui>t  of,  bis  discovery  of 

properties  of,  i.  369 

Celesline,  i.  .^2J 

'  iti  affinity  for  wRter,  >i.  .366 

diuolred  by  water,  i.  370 

Celsus  and  Pliny  on  water,  ii.  369 

^ »ourx;e»  of,  1. 370 

Celts  of  antiqaity.  il  A/H 

i.37f 

Cement  of  the  ancients  for  waler- 
cUtems,  U.  393 

Carbonic  oiide,  i.  372 

''  inhalation  of,  i.  374 

Cements  made  with  baryiei.  i.  .161 

Carbonic  oxide  pa,  produces  apo- 

Cerauniaorthunderslonea.ii. 472 

plexy,  i.  374 

Chalk  and   limestone    early    ex- 

Carburet of  nitrogen,  i.  337 

ported  From  England,  i,  646 

Carburetted  hydroKcn  gai,  i.  376. 

Chaloner,  Thomas,  >.  JC 

609 

Chaplal  on  domestic  washing,  IL 

335 

i.3S4 

on  bleaching   by  means  of 

Caspar  Lebiminii,  glass-cutter  to 

compressed  ileani,  it.  336 

the  Court,  ii.  178 

on  bleaching  old  prinls.ii  340 

Cwiius,  the  purple  precipitate  of, 
iwedinChina,  ii.  141 

bis  glare  for  pottery.  iL  !29 

i.  42^ 

DuUeabTe  iron,  ii  540 

his  account  of  French   aal- 

rarictie,  of,  ii.  635 

Charcual,  lU  pieparalion,  i.  396 

682 


INDEX. 


CKarooaly  Its  oomparative  value  as 

fuel,  i.  148 
— —  its  nature,  i.  392 
— —  for  gunpowder,  i.  402 
'■         a  bad  conductor  of  heat,  i.4 15 
I        extemporaneous,  i.  406 
— — >  found  in  Herculaiieum,  i.  407 
•*—  quantities  obtained  by  Allen 

and  Pepys,  i.  409 
•—  its  porosity,  i.  392. 410 
■  its  selection  for  different  pur- 
poses, i.  410 

■  ■     pigment  of,  i.  41 1 
»—  from  oil  r^se,  i.  412 

■  ■       of  resins,  i.  4 13 
-»—  animal,  i.  414 

—  perfectly  infusible,  i.  415 
•—  Its  use  in  domestie  economy, 

i.418 
— —  its  action  in  purifying  various 
substances,  L  421 
'■  its  uses  in  the  arts,  i.  422 
'       employed  in  manufacturing 
iron,  i.  428 

—  Elisabeth's  restriction  in  mak- 


ing, i.  429 
!S  thi 


Charles  the  aeronaut,  i.  51 

Charmes  on  bleaching,  i.  21 

Charred  turf,  i.  150 

Charring  of  timber,  i.  423 

— —  of  wood,  facts  respecting,  i. 

407 
— —  of  living  chesnut  trees,  i.  427 
Chaucers  account  of  English  edge- 
tools,  ii.  485 
Chemical  black,  how  made,  i.  279 

—  bleaching,  its  advantages,  ii. 

305 
■         discharges,  i.  20 

—  furnaces,    observations     on 

erecting,  L  G15 
■"      knowledge,     important    in 
bleaching,  ii.  297 
lectures,   a  national  advan- 
tage, i.  7 
— — •  mordants  of  antiquity,  i.  251 

—  residuums,  i.  28 

—  tests  for  bleachers,  ii.  334 

vessels  of  stone-ware,  ii.  90 

Chemist,  his  peculiar  resources, 

1.42 
Chemistry,  an  essay  on  itj  impor- 
tance, i.  1 


Chemistry  Interesting  to  evtiy  na- 
tion, i.  8 

— —  its  value  to  land-owners,  i.  8 

-<— —  eminently  indebted  to  Lord 
Bacon,  i.  4 

-^—  should  be  a  brandi  of  educa- 
tion, i.  6 

—  its  importance  in  detecdng 

poisons,  L  13 

—  its  use  in  dyeing,  L  18 
— ■  ■  to  tanners,  L  23 

■  to  glassmsdcers,  L  S3 

— ^— —  to  soapmakers,  L  27 
— -^—  to  brewers,  L  32 

to  sugar-refiners,  i.  34 

Chemistry,  its  use  to  refinen  of 

gold  and  silver,  i.  35 
-^—  o/use  to  paper-makers,  L  38 

—  knowledge  of,  usefiol  in  gar- 

dening, i.  41 

--—  its  use  to  the  Frendi  manu- 
facturers, i.  461 

^—  gives  the  habit  of  investiga- 
tion, i.  44 

Cherry  abounds  idth  citric  add,  L 
572 

Chimney  registers,  L  156 

walls,!.  168 

Chimneys,  remarks  on,  1.  156 

China  blue  dipping,  i.  184.  295 

Chinese  porcelain,  i.  21 

pedlars,  i.  59 

lands  obtained  from  the  sea, 

i.  196 

method  of  purifying  water, 

U.404 

their  practice  of   watering 

land  artificially,  ii.  426 
Chintz  printing,  i.  302—305 
Chlorate  of  barytes,  i.  350 

—  of  potash,  accident  with,  L 100 
Chloric  ether,  i.  385 

Chloride  of  lithium,  ii.  67 

of  lime,  i.  261.  ii.  302 

— — its  use  in  handker- 
chief printing,  i.  300 

its  action  in  bleach- 


ing, u.  308 

—  of  barium,  i.  342 
Chlorine,  its  diicovery,  ii.  275 
^—  its  introduction  m  bleachine, 

ii.  275 

—  introduced  in  Scotland,  il  277 


Chlorine  (FiLi,  diuiger  of  inhgiUiig, 

preparations,  the  strrngth  of, 

in  bleaching,  of  great  iiii- 
portance,  u.  332 

convcrU  gum  to  c 

i.  &18 

Cliloro-carbonic  acid,  i.  374 

Chlorocjanic  acid,  i.  388 

CholMMLunp,i.  371 

Cbromate  of  baryto,  i.  3.W 

Chromic  atccl,  boir  urepared,  ii. 

Chrrsalidei  ofailk- 
ductive  oft 
Citrate  a(  barytcs,  i.  3ul 

of  lirae,  i.  545 

• ■  cautions  in  making, 

i.  S'la 

quantity    procured 


IS  very  pro- 


■         ntnbluhmtnl  for  makbg,  i. 

544 
directions    for  crystalliiing, 

i.  iti^.  553 
eitabliihment    for,    in   the 

iiland  of  Sicily,  i.  563 
found  in  icveial  veiretablci, 

i.  672 

its  chemical  affiniliei,  i.  573 

the  form  of  ita  crTstali,  i.  574 

its  composition,  i.  574 

. uses  of,  i.  680 

its  action  on  miUt,  i.  580 

its  action  with  opium,  i.  580 

of  use  in  djreing,  i.  583 

used   lai^ely  by  the  calico- 
printers,  i.  584 
Citric  and  tartaric  acids,  theirdif- 

ference,  i.  575 
—  salts,  list  of,  i.  57G 
Citrons  of  Canada,  i.  5C7 
Citron  wood,  i.  540 
— —  tables  highly  prized  bj  the 

Romans,  i,  644 
Clariie,  Dr.,  his  mode  of  producing 

barium,  i.  357 
CUy,  ancient  method  of  temper- 

ing.  ii.  75 
~—  its  vttiiciy  in  Dritain,  ii.  S8 


Clay,  huwprepat  ed  In  Saxony,  ii. 98 

— I —   four  kinds  employed  in  the 

potteries,  ii.  104 

prices  of,  in  Slafibrdshlrc,  iL 

104 
how  prepared   in   Stafford- 
shire, u.  113 

for  the  Alcarazas  of  Spain, 

how  prepared,  ii.  114 
the  tempcriurprocess  in  Staf- 
fordshire, u.  1 16 

different  properties  of,  Ii.  156 

Stourbridge,  i.  166 

pill,  mode  of  sinkinK,  11.594 

Its  various  uses,  ii,  UKi 

Clays,  how  distinguished  by  Iho 

Romans,  ii.  104 
Clayton,  Dr.  John,  the  discoverer 

of  coal  gas,  i.  381 
Cleansing  calicoes,  i.  265 
Cleanlioesi    occesiary     to    good 

bleaching,  u.  325 
Clement  and  Ueaormes,  i.373 

on  sulpburctof  carbon,  i.  390 

their  theory  of  the  formation 

of  sulphuric  add,  i.  491 
Climate,  variety  of,  i.  50. 62. 62 

causes  of  changes  in,  i.  70     : 

Clock-making,    when  firat  iotnH  - 
duced,  i.  468  ^ 

Cloth,  fulUng  of,  ii.  15 
Cloudberry  of  Norway,  L  672 
Coal,  mineral,  i.  448 
Coals,  ciostilication  of,  i.  433 
Coal,  on  the  methods  of  cokeinr, 
i.  15 

on   the   methods  of  econo- 

miring,  i.  17i) 
■      the  waste  of,  explained,  1.1/0 

best  kind  for  funushing  gas, 

i.376 

variety  of  its  strata,  i.  453 

of  Stointhorue,  1.  454 

n  singular  kind  found  at  Sea- 
ton,  i.  454 

thrown  up  from  the  sea,  i.  464 

sometimes    &rcs    spontauo* 

ously,  i.  104 
Coals,  specific  gravity  of,  L  449 
Coal  of  ['ontetaivc,  i.  449 
Cools,  observations  on   the  cod- 

BumptioQ  of,  i.  147 
Caal-piis,  tnflammaUc  air  of,  i.  453 


I 


684 


INDEX. 


C<Mi)f » tulphimmSf  to  be  avoided,  i. 

Coal,  an  ecoBomieal  stopper  for 
lumace  mouths,  i.  159 

—  its  boundary  line  in  Scotland, 

i.456 

■  district  of,  in  Britain,  i.  456 
— —  damp,  method  of  destroyuM;, 

i.  452 

■  L       mines,  ezploeions  in,  i.  44 

—  ^as,  cost  of,  L  377 
r —  tar,  i.  401 
Cobalt-blue,  L  41 

■f      citrate  o^  i.  576 
Cocbineal  employed  by  the  an- 
cients, i.  252 
Cmns  of  iron,  andent,  iL  501 
Coke,  its  Various  uses,  i.  430 

orens,  i.  15.  174. 430 

-»—  for  making  iron,  L  429 

— - — the  kind  most   resembling 

charcoal,  i.  15 
■■        grOtind  with  day  for  making 
«         cmdbles,  ii.  150 
'  ■  '    new  method  of  making,  i.  431 
Colbert's  encouragement  of  mana- 

ftctures,  i.  179 
— -^  his  care  of  French  artists,  i. 

195 
Cold,  method  of  modifying,  i.  140 
'         provisions  of  nature  against, 
i.  140 

—  artifidal,  directions  for  pro- 

ducing, i.  125 
.      the  greatest  degree  of,  hither- 
to observed,  i.  125 
-—  produced  by  evaporation,  in- 
stances of,  L  108 

■  '       theory  of  its  production  by 

snow  and  salt,  i.  1 1 9 
Collier,  his  furnace   for    making 

steel,  ii.  488 
Collieries,  mode  of  lighting,  i.  31 
Colour,  for  pencil  blue,  how  pre- 
pared, i.  289 
'  t      shades  of,  in  tempering  steel, 
iL508 

■  of  logwood  improved  by  wa- 

ter, ii.  359 
Colours,  chenxical,  i.  19 
— ^ —  on  the  extraction  of,  L  186 

■  various,  produced  from  mad- 

der,  L  276 


Cdoori  employed  io  Solomon's 

temple,  i.  247 
.        in   the  Jewish    tabemade, 
obaervations  on,  L  247 

on  Indian  calicoes  imparted 

by  tbe  pencnl,  i.  628 

vegetable,  changed  by  alka- 
lies, ii.  8 

— ^-  various,  produced  by  chemi- 
cal dischaige,  L  291 

how  applied  to  oaUcoes  in 

India,  L  256 

Coloured  linens,  their  antiquity, 
L  246.  248 

—  stripes  on  cotton  hose,  iL 
348 

Colleges  established  by  the  Ro- 
mans for  teaching  weaving, 
L246 

Colomns,  basaltic,  L  190 

Combustion,  theories  of,  L  75 

new  theory  of,  L  76 

■         not  destruction,  L  80 

the  products  of,  i.  81 

^— —  produced  by  the  mixture  of 
fluids,  i.  103 
.  ice   and   potas- 

sium, i.  103 
■  spontaneous  cases  of,  L  103 
ofthe  human  bo- 


dy, i.  106 
Combustibles  and  incombustiblei, 

L76 
Committee  of  Public  Safety  on  cast 

sted,  iL  490 
Composts,  on  the  management  of, 

L  10 
Compressed  steam  used  in  bleach- 

ing,  U.  334 
Condensation  of  water,  ii.  362 
Conductors  for  lightning,  i.  93 
Confectionary,  when  first  prepar- 
ed with  ice,  i.  122 
Cooling  of  fluids  by  ether,  i.  1 10 
Cooper  8  dissertation  on  the  Smell, 

u.  432 
Cooper,  Dr.  Thomas,  of  America, 

ii.285 
Cooper's  adze,  how  made,  ii.  495 
Copland,  Mr.  Professor,  ii.  277 
Copland  and  Watt,   their  claims 

respecting  gas    bleaching, 

ii.281 


INDEX.                                        68&                  1 

Copper  iniuti  of  Coniwail,  i.  36 

CryophoruiofWalluton. !.  126 

art  of  tempering  for   edge- 

Crystal,  a  remarkable  one  ol  tnt- 

tools,  >i.  4dl) 

phwe  of  b«ryte»,  i.  315 
Crystal liiation  of  salts,  1.  37 

and  br«M,  the  art  of  working. 

kaowntotheAnglo-SuEoni, 

Cryslallo  Cetamie,  patent  for,  ii. 

ii.  611 

236 

implements  of  great  wtlqni- 

tT,  ii.  480 

Codbenr,  i.  39 

cell,  abundant,  ii.  481 

CuUnary  utensiU,  use  of  double 

various  solution,  of,  i.  284 

ones,  i.  143 

printing,  i.  284 

citrate  of,  i.  576 

Cumberland-,  oulheti  flies,  ii.  515 

plate-printing  on   china,  ii. 

Cuthbertson's  apparatus  for  pro- 

HS"^ 

ducing  water  by  combus- 

piate^^en^^avifg. bleaching 

tion.  Ii.  S67 

Cutlery,  iU  progress  in  England, 

Comiih  clay,  ii.  ]fl9 

ii.485 

Knnite,  ii.  11)9 

ComwaJl,  tin  minei  of,  i.  627 

472 

instruments  improved  by  the 

i.249.     ii.  261 

addition  of  .il»er,ii,  546 

miU),ereLti(.nof,  1.173 

Cyanogen  and  iodine,  i.  369 

Corinus,  a   terrible  war-chariot. 

Cylinder  charcMl.i  397 

il.  482 

printing,  i.  306 

Coiwell,  Mr.,  i.  5S4 

Cynosbatua  vtl  rosa  canins,  uied 

Criwford.  Dr.,  hit  MperimenUon 

heat,  i.  63 

D. 

en  respiration,  i.  65 

on  muriate  of    bsrytc*,    i. 

Dacier,  Madame,  on  the  andent 

W2 

scarcity  ofiron.  U.  476 

on  the  barytic  lalti,  L  634 

Crayoosofcharcoal,  i,  411 

152 

Cranne.  a  technical  term  in  pot- 

Dalton, Mr,,  on  hard  water,  ii.  371 

tery,  ii.  105 

i>ii  the  density  of  water,  i. 

Creil,  on  citric  add,  i.  562 

207 

Crofting  calicoes,  u.  272 

hia  table  of  the  eipaoiion  of 

CfonttM's  lugar  patent,  t.  4I!> 
Crown-glas*.  ii.  191 

water,  ii.  416 

on  the  expansion  of  gases,  i. 

236                           * 

the  procei*  of  formlDg,  IL 

1!)5 

on  lime  burning,  ii.  .'tfi6 

his  experiment  on  the  forma- 

dirided  into  (our  clutei,  U. 

tion  of   sulphuric   acid,  L 

200 

492 

Cruciblei,  on  the  mftnufsctur*  of, 

hi*  table  of  the  boiling  point 

ii.  149 

of  sulphuric  acid  at  different 

for  glais-mftking.  1.  H5 

deniiiies.  i.  518 

how  made  in  Prance,  ii.  ISO 

Dumnti'us  swords,  ii.  52).  613 

of  clay  and  calcined  mica,  ii. 

sword  blade  described,  ii.524 

597 

ed  alloy  of  steel  and  chro- 

i, 372 

mium,  ii,  543 

686 


INDES. 


DunukeenSng,  the  art  of,  iL  614 
DavieSy  Dr.,  oq  the  areometer,  i. 

210 
his  tables  of  speciic  ffraFitT, 

1.210 
'        his  observations   on  mixed 

metals,  i.  223 
Davy,  Sir  Humphry,  on  tanning, 

■  on  the  diamond,  L  366 

on  orassic  gas  and  pmssic 
aad,i.  ^ 

■  on  charcoal,  L  413 

'  on  the  formation  of  sulphuric 
add,  i.  493 

-— »  on  the  agencies  of  galvanism, 
U.58 

*»—  his  discovery  that  the  affini- 
ties of  bodies  are  altered  by 
tfadr  states  of  electridty, 
it.  69 

-  ■—  his  decomposition  of  the  al- 

kalies, iL  59 
— —  a  detail  of  these  discoveries, 
ii.59— 66 

■  his  decomposition  of  carbonic 

add,  i.  371 
his  attempt  to  breathe  car- 
bonic oxide,  L  374 
— —  his  investigation  of  the  fire- 
damp, L  128 

■  his  safety  lamp,  i.  43 

■  ■  ■  his  own  remarks  on  the  safe- 

ty lamp,  i.  139 
■     his  observation  on  the  con- 
struction of  the  universe, 
i.81. 

Davy,  Dr.  John,  the  discoverer  of 
chlorocarbonic  add,  i.  374 

'■  his  reason  for  nanung  it  Phos- 
sene  gas,  i.  375 

Dedmu  weights,  i.  208 

Decoction  of  Dark  for  dyeing,  i.  186 

Decoction,  distillation,  8^.  pro- 
cesses, ii.  605 

Decompositions  produced  by  ex- 
treme cold,  i.  117 

"-—  of  water  may  produce  com- 
bustion, i.  lOj 

—  of  sulphate  of  barytes,  i.  319 
Delanidtherie  on  steam  bleaching, 

ii.335 
Delfware,  manufacture  of,  ii.  154 


Democritos  of  Thrace,  L  42 

■        on  the  origin  of   iff  vhg, 

U.260 
Denuty  of  bodKes,  L  2(^ 
Description   of    the    magaaest 

nune,  H.  341 
DedderaUia  giaaa  BMkiiMr»&  Ml; 

— ooaervatwitts  01I9  n.  smj 
Desiderata  in  Kif^fi^fwg  cidieoeiy 

fi.317 
Desmarets  on  the  best  method  of 

watering  meadows,  fi.  427 
Devonshire  nunes  of  pianganesi^ 

ii.34i 
Dew,  its  effect  in  UeachiBg,  u.  266 
IKamond,  i.  366 

method  of  valuing,  L  366 

of  the  Emperor  of  Rus^ 

i.367 

method  of  polishing,  L  367 

~— -  decomposes  the  rays  of  fiiAt^ 

i.367 
— •  of  BradI,  L  367 
burnt  at  Florence,  L  369 

—  burnt  by  Lavoisier,  i.  3G9 
•^— -  a  curious  account  of  its  ac- 
tion in  cutting  elass,  a.  599 

Diamond8,laige  size  of  some^  L  636 
Dibutates  of  Sicyon,  i.  21 
Discharge  woric  in  printings  i.  291 
Discharges  by  dtric  add,  i.  295 
DistUUdon,  i.  33.  174 

of  pyroligneous  add,  L  401 

a  process  capable  of  great 

improvement,  i.  610 
Distilleries,  i.  146 
Dis^  on  the  manuCMture  of  dtiic 

acid,  i.  552 
— —  on  the  produce  of  dtrate  of 

lime,  i.  570 

—  on  flavouring  lemonade,  1.582 
Dog^h,  nroposal  respecting,  b. 

DolUus  on  hyperoxymuriatic  salts, 

ii.351 
Dome  and  back  copper,  i.  175 
D'Orelly*s  apparatus  for  bleadiing 

by  steam,  ii.  337 
Domestic  implements  of  antiquity 

made  with  copper,  ii.  477 
Doors  of  fire-places,  i.  153 
for   reverbcratory  furnaces, 

i.  157 


Doora,  double,  uie  of,  i.  1-13 
Doasie,  Mr.,  on  furnawB,  i.  JSa 
on  the  prcpajaHon  of  ateel, 


'        hisuccoantof  uJ-ammooiac, 

ii.460 
Dragoons,  a  regiment  of,  bartered 

for  porcelain,  ii.  98 
Drebbcliiu.  the  inventor  of  the 

scarlet  ilye,  i,  20 
Drwdcn  porcelain,  ii.  Dfi 
Drills  of  steel,  bow  hardened,  ii. 

513 
Drfing  printed  calicoes,  i.  272 
Du  Buisson's   procesn  for  conccn- 

traUae  lemon  juice,  1.  542 
Dundonold,  EatI,  hi»  treatise  on 

Bgriuultiirc,  i.  9 

Dung  of  the  cow,  its  use  in  print- 
ing, i.  260 

Dunging  process  of  the  calico 
printers,  i.  260 

cdicoes,  i.  273 

— ^  macbino,  i,  273 

Durability  ofcharowl,  i.  411 

Dutch  bleaching,  ii.  264 

DutT  on  lalt  allowed  for  bleachinir, 
ii.295  " 

Djeing,  a  chemical  process,  i.  18 

• antiquity  of,  i.  2-18 

-^—  with  madder,  i.  193 

Dyen  and  bleachers  require  pure 
water,  il  372 

Dyers'  vnts  of  antiquity,  L  352 

Dye-woods,  manogcmeat  of,  i.  186 

decoctions  oi,  made  in  ves- 


Early  life  of  Mr.  Yarranton,  li.  577 
Earthen  conduit  pipes  of  the  Ro- 
mans, ii.  592 

veitelt,  Roman,  ii.  73 

reMcis  of  the   Phcenicians, 

il.  79 
Earthenware,  an  essay  on.  ii.  73 
mauufiicture  of,  i.  21 


EX.  687 

Elarthenwnre  ani  porcelain,  i.  17^ 

material)  for,  ii.  103 

evidences   o(    its   antiquity, 

ii.  75 

ancient  traffic  in,  iL  7G 

ofEgypt.  ii.  77      . 

boats  of  antiquity,  u.  77 

English,  ii.  S7 

manufacture  of,  improved  by 

Mr.  Wedgwood,  u.  87 

a  caution  rcspccUog,  ii.  90 

while  enamel,  ii.  90 

burning  of,  ii.  120 

manufacture  of,  in  Egypt,  U. 

593 
Earths,  their  analysis  important 

to  the  potter,  it  166 

for  scouring  linen,  ii.  2C3 

Economical  Society  of  I'aiis   on 

the  English  alloys  of  steel, 

ii.  547 
Economy  of  using  soft  water,  iL 

373 
Edge-toots,  essay  on  the  maoufttc- 

tureof,  il.471 

oF  ancient  nations,  ii.  472 

of  Japan  made  with  an  alloy 

of  copper,  ii,  47s 
of  itecl  known  to  the  ancient 

Egyptian!,  U.  479 
some  of  the  varioui  methods 

of  mailing,  ii.  495 
—  —  motive  (or  writing  on  their 

manufacture,  ii.  508 
tempered  at  various  tempe- 

certain  raioutiB  respecting, 

ii.512  "^^ 

cause  of  their  wBipiog,  ii.El2 

improved  mode  of  tempering, 

imured  by  grinding,  ii.  53S     ] 

of  cait4riLiD,  ii.  534 

made  with  vaiiotii  metallic 

alloys,  ii.  542 

formed  with  an  alloy  of  iteel 

and  chromium,  ii.  54>l 

Edgeworth'i  Prussian  vaic,  ii.  1 0 1 

Edinburgh  spring-water  remark- 
ably pure,  ii.  o84 

Efflorescence  and  deliquescence  of 
salts,  ii.  364 

Egypt,  fertility  of.  ii.  426 


688 


INDEX. 


Bgyptiaa  obeHskSy  i.  16 
-^—  mummies,  i  242 

embalmers,  ii  473 

method  of   calico  printiag» 

i.  250 
— —  8al-ammoniac»  ii.  438 
£ir]rptians,  their  antipathy  to  wool, 

i.  249 

—  clum  the  invention  of  gla8t» 

11.  168 

. magnificent  glast  cops  of,  U. 

170 

Elastic  bitumen,  i.  455 

Elasticity  of  glass,  instances  of, 
ii.  240 

Electricity,  i.  89 

a  mode  of  producing  com- 
bustion, i.  89 

—  on  the  excitation  of,  i.  89 
..^—  voltaic,  i.  90 
Electrical  kite,  i.  92 

kite,    cautions     respecting, 

i.94 
Electrical  and  chemical  attraction, 

ii.  65 
Electrical    excitability    of   glass, 

ii.  240 
Elk  and  rein  deer,  i.  53 
Ellicott*s instrument  for  measuring 

the   expansion  of  metals, 

i.235 

John,  on  the  specific  gravity 

of  the  diamond,  i;  636 

Emery,  ii.  1 58 

a  native  substance,  i.  224 

from  whence  procured,  i.  224 

bow  prepared  for  glass  grind- 
ing, ii.  223 

Emperor  of  China,  declaration  of, 
i.  460 

Empyreuma  of  brandies,  i.  419 

Empyreumatic  fat  more  efficacious 
in  tinning  than  fresh  tal- 
low, ii.  5o2 

Enamel  painting,  il  91 

England  formerly  supplied  with 
tin  plates  from  Bohemia 
and  Saxony,  ii.  571 

English  cloths  formerly  bleached 
in  Holland,  ii.  268 

— —  process  for  making  sal- 
ammoniac,  ii.  449 

Engraving  on  porphyry,  ii.  479 


Engraving  of  bankers*  notes,  ii. 
506 

Bnthusiasm  of  the  French  respect- 
ing making  steel,  ii.  490 

Entrecolles,  Francis  de,  ii.  94 

Epsom  salt,  its  action  on  vege- 
tables, i.  10 

Equivalent  numbers,  the  theory  of, 
i.342 

—  an  extensive  Table  of, 

ii.  621 

Ersgebirg,  tin  mines  of,  ii.  571 

Essay  on  the  importance  of  che- 
mistry, i.  1 

Essays  on  the  management  of  flax, 
ii.  400 

of  the  Dublin  Society,  n.400 

Establishment  of  the  manofscture 
of  tin-plate  in  Paris,  iL  579 

Ether,  its  eff(H:t  in  producing  eold, 
i.  110 

Ethereal  solution  of  gold,  ii.  540 

.Ethiopians  inclosed  their  dead  in 
glass,  ii.  170 

Etmria,  an  account  of  its  mann- 
factory,  ii.  101 

Etruscans  noted  for  fine  porceluo, 
U.  83 

Etruscan  vases,  u.  594 

Eudoxus  the  astronomer,  i.  83 

Europe  formerly  colder  than  it  b 
at  present,  i.  54 

Evelyn,  Sir  George,  on  weights  and 
measures,  i.  200 

Expansion  of  gases  by  heat,  i.  235 

Expedients  for  preserving  the 
warmth  of  provisions,  i.  146 

—  for  producing  permanent  co- 

lours, i.  25>9 
Elxperiment  of  glass  heated  on  a ' 

revolving  grit  stone,  i.  102 

on  dunging  calicoes,  i.  274 

on  burning  lime,  ii.  366 

on  the  quality  of  water,ii.375 

on  tempering  iron  and  ateel, 

ii.  504 

on  heating  steel,  ii.  531 

on  blueing  steel,  ii.  51 1 

—  for  condensing  water,  iL362" 
Explosions  of  the  fire-damp,  i.  127 
Eye,  aqueous  humours  of,  ii.  431 
Eyes,  of  animals,  frozen  for  dissec- 
tion, i.  121 


INDEX. 


689 


p. 

Fabbroni  on  bleachiog  old  priott, 

11.339 
Fahrenheit,   his  thermometer,   i. 

'   120.237 
Falconer,  Dr.  on  the  pBSU  of  the 

ancients,  U.  23§ 
Faraday,  Mr.,  hit  discovery  of  hy- 
driodide  of  carbon,  i.  337 
"his   analysis    of  a    peculiar 
bone,  ii.  534 

on  the  analysis  of  wootz,  ii. 

494 

—  on  perchloride  of  carbon,  i. 

385 
on  protochloride  of  carbon, 

1.386 
on  the  alloys  of  iron  and  steel, 

ii  542 
Parish,  Professor,  his  lectures,  i.  7* 
Felspar,  its  analysis  by  Vauquelin, 

U.  595 
the  best  glaze  for  porcelain, 

ii.  594 
Felting  of  hats,  i.  40 
Females  destroyed  by  spontaneous 

combustion,  i.  107 
Fermentation,  acetous,  i.  33 

—  vinous,  i.  32 

Fern  employed  in  fulling,  ii.  16 

its  use   in   milling  wooUen 

cloth,  ii.  585 
Ferrara,  Andrew,  his  mode  of  tem- 
pering swords,  ii.  522 
Fiery  ground  of  Staffordshire,  i.  105 
Files,  an  expedient  for  hardening, 
ii.516 

—  how  finished,  ii.  518 

— —  of  case-hardened  iron,  ii.  518 

i manufactory  of,  ii.  515 

of  earthenware,  ii.  515 

Filtrating  water,  ii.  3S5 
Fine  lawn  of  Achaia,  ii.  258 
Fire,    expedients  for  producing, 
1.82 

—  venerated  by  the   ancients, 

i.  82. 

■  an  ancient  image  of  life,  i. 

82 

■  worshipped  by  the  Persians, 

1.83 

VOL.  II.  2 


Fire  unknown  to  some  nations* 

i  83 

procured  from  the  sun,  i.  84 

■    ■  its   production  by  collision, 

i.  84.  96 

produced  by  phosphorus,  i  98 

— —  produced    by    compression, 

i.  100 

—  produced  by  compression  of 

air,  i.  101 

—  procured  by  percussion,  i.  102 

—  produced  by  friction,  i.  102 
damp  of  the  collieries,  i.  127. 

452 
chemical  nature  of,  i. 

128 
its    combination    with 

oxygen,  i.  136 

—  places  of  furnaces,  i.  160 

<■ bars,   their  construction,   L 

162 
— —  lute,  directions  for  making, 

i.  166 
management  of,  i.  171 

—  some  memoirs  on  the  pre- 

vention of,  i.  466 
— —  subterranean,  i.  105 
Fish  decompose  water,  ii.  .357 
oil,  how  purified,  i.  25 

—  thrown  from  ii  volcano,  i.  63 
Flame,  its  nature,  i.  132 

its    peculiar    temperature, 

1.132 

Flax  called  byssus,  ii.  258 

dresser,  best  situation  for, 

ii.  401 

its  early  cultivation,  i.  242 

— ^—  method  of  bleaching  in  Hoi- 
land,  ii.  400 

Flaxen  yarn,  how  bleached,  ii.  270 

Flint  a  native  oxide,  i.  96 

—  and  steel  of  the  Laplanders, 

i.  84 

and  steel,  their  employment 

in  the  collieries,  i.  96 

—  glas^,  cause  of  its  superior 

brilliancy,  ii.  H9 

glass  in  potters*  glaze,  ii.  137 

— ^  glass,    process  of   making, 

ii.  184 
— — >its  price  in  the    potteries, 

ii.  108 


090 


INDEX. 


Flints,  ipround,  formerly  used  in 

glass^  ii.  188 
—  bow   prepared    for  pottery, 

ii.  1 11 
Fluate  of  barytes,  i.  351 
Flues  for  furnaces^  i.  170 
Fluids,  the  specific  gravity  of,  bow 

estimated,  i.  208 
Fordyce,  Dr.,  on  the  colours  of 

light,  i.  75 
'  his  heated  chamber,  i.  71 

Forging  of  small  edge  tools,  ii.  497 
Formate  of  barytes,  i.  351 
Forsyth's  percussion  gunpowder, 

i.  100 
FossU  alkali,  ii.  37 

meal,  ii.  161 

Founderies  estabUshed  inthiscoun^ 

trv  by  the  Romans,  ii.  612 
Foarcroy  s  account  of  sea-water, 

ii.  463 
'  on  the  diamond,  i.  366 

on  the  mucilage  of  lemon 

juice,  i.  595 

« his    proposals    for   making 

citric  acid,  i.  562 

Fourmy,  Mr.,  on  the  potter's 
fflaze,  ii.  137 

Fowler  s  drop,  ii.  22 

Fowling-pieces,  i.  192 

Foy,  Mr.,  his  bleaching  pro|)osa], 
ii.  292 

France,  young  nobility  of,  formerly 
laboured  in  the  manufac- 
tory of  glass,  ii.  1 76 

Frankland,  Sir  Thomas,  on  cast- 
steel,  ii.  492 

Franklin  on  lightning  and  electri- 
city, i.  92 

French  cutlers,  ii.  490 

gunpowder,  i.  406 

— —  manufacturers,  their  atten- 
tion to  chemistry,  i.  461 

method  of  hardening  steel 

instruments,  ii.  501 
Frigorific  mixtures,  materials  for, 

i.  124 

of  Mr.  Boyle,  i.  120 

Frit,  its  preparation,  ii.  193 
Frittingu)vens  in  France,  ii.  194 
Frozen  mercury,  experiment  with, 

i.  68 


Fruit  stains,  method  of  remonng 

firom  linen,  ii.  340 
—  artificially  frozen  at  Fnis, 

i.  121 
Foci,  its  analysis,  iL  16 
Fuel,  comparative  beat  of,  L  148 
— —  on  the  oeconomy  o^  L  147 
— — -  manufectured,  L  450 
Fugitive  dyet,  i.  309 
Fumame,  Mrs.,  her  experiments, 

i.392 
Fuller,  anecdote  of,  ii.  602 
Fullers  earth,  u.  16. 158 
Fullers  in  ancient  Rome,  ii.  378. 

604 

soap  of  the  Hebrews,  ii.  262 

FuUing-inill,  iL  15 

■  for  hose,  ii.  309 
the  process  of,  expbuned,  iL 

15 
Furnace  bars,  varieties  of,  L  162 
Furnaces,  best  method  of  feeding, 

L170 

■  '         a  curious  noode  of  heatno^ 

at  St  Gobin,  iL  228 
— -  doors  and  frames,  i,  153 
'  for  annealing  caat4ron  cut- 

lery, ii.  542 

—  for  plate-glass,  expense  ci, 

u.  215 

—  on  their  erection,  i.  152 

— — —  on  the  method   of  heating 
them,  L  157 
I  reverberatory,  ii.  69 

Fusibility  of  earthy  compounds, 
'  iL  130 

Fusion  of  basalt,  i.  188 

— -  of  chalk  and  marble,  L  188 

G. 

Gallate  of  barytes,  L  352 

of  iron,  L  279 

Galvanic  battery,  Mr.  Children*!, 
L90 

—  of  the  Royal  Institution,  L  91 
Galvanism,  i.  90 

—  powerful  effects  of,  i.  92 
Game,  preserved  by  charcoal,  L 

418 
Gardeners  of  Paris,  iL  429 
Garments,  anciently  of  bulmshe, 

ii.260 


INDEX.                                              G9I                     1 

Gu  UemchinK  lntroduc«d  tX  Man- 

01099,  used  in  the  time  of  PUdv, 

chraler.  u.  283 

ii.  169 

introduEed  in  Fnnc»,  ii.  286 

found  in  the  ruins  of  Her- 

culaneum,  Ii.  169 

i.376 

mtdltable,   discovered  by  k 

lightB.  i.  30 

tint  ouplayed,  i.  30 

bouses  of  theTyriansiil?! 

procured  from  oil  «ecd'.i.379 

bouses,  earlr  one*  in  Great 

ilB  produce  from  coal,  i.  37ti 

Britain,  ii.  172 

work,  in  WorBbip-Hreel.  U. 

■167 

into  England,  ii.  172 

Owea  expelled  horn  the  lungs,  i. 

Ute  introduction    of. 

intoEurope.  ii.  173 

quanlily  nhsoriwd  by  chnr- 

the  art  of  painting  on,  first 

coul.  i.  410 

introduced,  ii.  174 

ipcciiic  grtvitv  of,  i.  624 

lheircapacityforcaloric,i.68 

the   art  of   slainini;,   Utely 

known  in  England,  ii   176 

Gay  Liuinu  on  the  formalion   of 

stained,  knowntotlieCreekl 

chlorocyHDic  Hcid,  i.  JH8 

andRomau!,  ii.  17S 

quantity  of  made  in  Bohe- 

nitrogen, i.  397 

mia,  U.  175 

Geber.  John,  u  chemist  of  the  8th 

substitute  for, InRussia.ii.  1 75 

converted  to  a  kind  of  uor- 

B    nan  of  great    acquire- 

menls,  >.  fid? 

celnin,  ii.  151 
hiitory  of  the  manufuture 

ill  Bohemia,  ii.  17'i 

Oellert-!.  table  of  affinitiei.  ii.  44B 

in  Frame,  ii.  176 

monUc,  ii.  438 

making  considered  honoar-' 

able  m  France,  il.  179 

his   table  of  chenJoI    aiB- 

niilei,  ii.  418 

grinding  and  cutting  when 

German   linen    doth  better  thui 

introduced,  ij.  178 

the  Irish,  Ii.  339 

known  to  the  andents,ii.220" 

steel,  i.  16.  ii.  487 

engraving  on.  by  fluoric  add. 

tinder.  J.  405 

u.  179 

Germination  of  leedi,  i.  39 

house,  establishment  of,  at 

GiU'a  apparaliu  for  taking  sprcilic 

TourUriUe,  ii.  179 

gravilie..  i.  228 

houses  established  in  Ull- 

msnufuclure,  ii.  95 

doQ.  ii.  1:^1 

Gioi*.  PUvio,  i.  3 

of.  inEngland,  It   181 

nlance-coal,  1.  447 

pit-coal    first   wed   In    tfaa 

manul>clure  of,  iL  182 

a  change  in  collecting  the 

liontef.     their     number   In 

duty  upon.  Ii.  161 

1696.  u.  lai 

houses,   fife  different  kindt 

ot.u.   167 

of,  ii.  183 

house  Ucr.ii.  197 

two  opake  bodiea,  il.  )67 

method  of  ucrrtiining  tht 

purity  of,  ii.  186 

when  inrented,  ii.  163 

utensils,  how  formed, ii.  IBS 

2 

^^^ 

692 


INDEX. 


Glass  a  bad  conductor  of  heat, 
ii.187 

■  its  nature  as  a  chemical  com- 

pound, ii.  238 

—  2o  distinct  properties  of,  ii. 

238 

its  ductility,  ii.  238 

its  transparency,  ii.  239 

of  the  ancient  Romans,  ii.  239 

—  in  the  windows  of  Pompeii, 

ii.  239 
— —  drinking. vessels  of  antiquity, 

ii.239 
eminently  elastic,  ii.  240 

—  impermeable  to  electricity,  ii. 

240 
unannealed,     curious     pro- 

perdcs  of,  ii.  240 

gnnding,  an  improvement  in, 

u.  222 
■■  incrustations,  ii.  236 

incrustations,  made  in  Bo- 
hemia, ii.  236 

—  utensils,  how  formed,  ii.  186 
'—  observations    on   annealine, 

ii.  245 

gall,  ii.  246 

for  holding  acids,  ii.  248 

—  lachrymatories  at  Rome,  ii. 

248 

of  peculiar  hardness  made  by 

borax,  ii.  251 

■  made  by  the  union  of  me- 

tallic oxides,  ii.  253 

of  antimony,  ii.  596 

ancient  coloured,  ii.  598 

trade,  technical  terms  in,  ii. 

599 

—  annealing  ovens  at  Raven- 

head,  ii.  229 

plates,  how  cast  at  Raven- 
head,  ii.  230 

Glass-maker  allowed  salt  dutyfree, 
ii.  211 

Glass-makers*  crucibles,  L  179. 
ii.  160. 

—  pots,  construction  of,  in  bak- 

in;;,  ii.  161 

—  method  of  decomposing  salt, 

ii.  212 
Glass-making,  i.  22 
technical  terms  of,  ii.  191 


GlaM-making,  denderata  in,  iL  241 

—  the  circumstance  on  which  its 

economy  depends,  ii.  253 
Glass  mirror,  a  French  one  of  on- 
common  size,  ii.  180 
——-^  mirrors,  manufactory  oC  at 

Murano,  ii.  177 
manufactories  of^  at  St.  Go' 

bin,  ii.  180 

antiquity  of,  iL  180 

Glastum,  or  woadi,  of  the  anciecti, 

i.  259 
Glauber  on  making  sulphuric  add. 

1468 

his  salt,  L  29.  ii.  56 

Glauberite,  L  524 

Glaze  of  china,  a  chemical  test  fav 

ii.  130 

—  how  applied  to  pottery,  n. 

128.  136 

of  the  French  potters,  iL  196 

Glazed  windows  still  unknown  at 

Rio  de  Janeiro,  iL  173 
Glazing  of  pottery  a   pemidoot 

operation,  ii.  137 

of  earthenware,  ii.  128 

Glucina,  citrate  of,  i.  577 
Goettling,  on  the  collection  of  hy- 
drogen, i.  151 

his  book  on  tests,  i.  14 

Goguet,  on  the  bleaching  of  the 

ancients,  ii.  263 
Gold,  statues  of,  in  Babylon,  iL 

610 
and   silver,    lavish   cmploj- 

nient  of,  by  the  ancieDts, 

ii.  609 

and  silver  refining,  i.  35 

scarpe  mountain,  i.  440 

touch-holes  of  gun-locks,  L 

192 
Good,  Dr.,  on  temperature,  i.  71 
Gordon,  Barron,  and  Co.,  ii.  278 
Government,  an  instance  of  its  in- 
jurious interference  in  the 

glass. trade,  ii.  205 
Gradation  of  colours  in  tempering 

edge  tools,  ii.  509 
Grain-tin  found  in  Bohemia  and 

Saxony,  ii.  572 
prepared  from  an  ore  called 

stream  tin-ore,  iL  561 


INDEX. 


693 


Granite  of  Cornwall,  ii.  109 

—  Comith,  employed  in  pot- 

tery, ii.  Ill 
Grants',  Mess.,  new  and  extensive 

manufactory,  i.  630 
Graviroeter  ofGuyton,  L  212 
Gravity,    absolute    and    specific, 

i.  200 

—  definition  of,  i.  200 

■  comparative,  i.  206 
Grease,agreat  impediment  to  good 

bleaching,  ii  322 

—  its  mischievous  effects  on  ca- 

licoes, i.  265 
— —  used  in  making  tin-plate,  iL 

562 
Grecian  statuaries,  ii.  89 
Greek-fire  of  antiquity,  i.  637 
Greeks,  their  proficiency  in  the 

arts  of  pottery,  ii.  76 
Green  stone  for  setting  lancets, 

ii.  534 

—  vegetable  matter  of  Priestley, 

ii.  603 
Gren  on  sulphate  of  soda,  i.  1 15 
Grindinc-stoncs  of  Sheffield,    ii. 

532 
Guhliche,  his  process  for  making 

aceto-citric  acid,  i.  583 
Gum    converted    to  citric   acid, 

i.  648 

—  largely  employed  in  calico- 

printing,  1.  268 
Gum  Senegal,  i.  2(>9 
Gnm  tragacanth,  i.  268 
Gun-barrels,  hardening  the  breech 

of.  i.  193 
Gunpowder,a  chemical  compound, 

i.  36 

■  its  composition,  i.  393 
its  manufacture,  i.  636 

—  the  peculiar  strength  of  the 

Bntish,  i.  405 
Guyton  and  Camy  on  chemical 
residuums,  i.  362 

—  on  charcoal,  i.  416 
his  pyrometer,  L  192 

H. 

Haarlem  bleaching  grounds  ii.  265 
Hadley,    Dr.,    on    the    Egyptian 
mummies,  i.  242 


Haldane,  Colonel,  on  electrical  bat- 
teries, i.  89 

Hales,  Dr.,  on  the  distillation  of 
sea-water,  ii.  406 

Hall,  Sir  James,  his  experiments 
on  iron,  ii.  491 

—  his  experiments  on  tempe- 

rature, i.  188 
Hamildon,  the  battle  of,  ii.  484    . 
Hammond  and  Co.,  their  patent 

for  an  instrument  for  cutr 

ting  glass,  ii.  601 
Hannibars  passage  over  the  Alpa, 

i.  6. 
Hard  water  the  best  for  irrigation, 

i.9 

—  fittest  for  ship-board,  ii.  406 
how  softened,  iL  407 

injurious  in  brewing,  ii.  399 

—  unfit  for  horses  and  cattle, 

ii.  380 

—  unwholesome  effects  of,  u. 

388 
Hard  waters,  ii.  370 

—  of  Portugal,  ii.  376 
Hardening  of  edge  tools,  iL  499 
of  filers,  iL  515 

Hardy,  Mr.,  on  steel-plates,  ii.  514 

Harper  and  Wilson's  patent  for 
purifying  tar,  i.  639 

Hartley  s  (David)  patent  for  tem- 
pering steel,  ii.  518 

on  tempering  edge  tools,  iL 

519 

Hasselquist's  account  of  the  manu- 
facture of  sal-ammoniac  in 
Egypt,  ii.  440 

Hassenfratz  on  the  manufacture  of 
iron,  i.  428 

— —  bis  table  of  nitric  tolutioos, 
L638 

Hatchets  of  copper  used  by  the  aiw 
cients,  ii.  480 

HatcheU,  Charles,  Esq.  i.  24 

on  elastic  bitumen,  i.  455 

— —  his  analysis  of  retinasphal- 
tum,  L  456 

—  on  tannin,  L  393 
Flat-felts,  i.  40 

Hauffmaun  on  the  theory  of  dye- 
ing, i.  632 

Heat,  how  produced  by  combus- 
tioni  L  76 


694 


IKD£X. 


Heat,  the  matter  of,  1. 47 

method  of  modifyingy  i.  107 

—  methods   for  preserringy  i. 

146 
»*—  on  the  economf  of,  i.  1 7^ 
Heath,  a  good  yellow  dye,  L  185 
Heaths,  on  the  cultivation  of,  i.  9 
Henry,  Mr.  Thomas,  ii.  280 

—  his  merit  vnih  regard  to  the 

bleaching  process,  ii.  284 
■         a  tribute  to  his  memory,  iL 

284 
Henry,  Dr.  WilUam,  his  apparatus 

for  freezing  mercury,  i.  123 
his  experiments  on  coal  gas, 

i.379 
his  experiments  on  common 

salt,  ii.  691 
memoirs  on  coal  gas,  i.  380 
on  spontaneous  combustion, 

i.  104 
on  the  temperatures  of  the 
porcelain  ovens,  ii.  132 
Heraldic  crests  preserved  in  the 

centre  of  glass,  ii.  237 
Hercynian  forest,  i.  54 
Herodotus  on  Arabian  alliances, 

U.473 
— -  on  pure  water,  ii.  403 
I         on  tlie  earthenware  of  his 

time,  ii.  76 
Hesiod  on  the  plough-shares  of  an- 
tiquity, ii.  473 
Hiirs  and  Haddock*s    patent  for 

making  sulphuric  acid  from 

martial  pyrites,  i.  642 
Hindoos,  their  practice  of  offering 

water  to  strangers,  ii.  404 
Hippocrates  on  water,  ii.  369 
Hoepfher  on  sulphate  of  barytes, 

i.3l3 
Homberg*s  areometer,  i.  210 
experiment  on  vinegar,  i.  34 

■  memoir  on  specific  gravity, 

i.204 
Home,    Dr.,   his    experiment  in 
bleaching,  ii.  274 

■  his  observations  on  the  French 

Academy,  i.  461 
'         on  agriculture,  i.  8. 

■  on  hai*d  water,  ii.  371  •  388 

■  oil  the  water  of  Edinburgh, 

ii.  384 


Honeyitone  of  Werner,  L  456 
Hooke,  Mr.,  on  the  alloy  of  tin  end 

silver,  i.  223 
Hope,  Dr.,  on  barytes,  L  324 
Hopper-doors  for  fomaces,  i.  158 

Hom-quicksilver,  i.  526 
Home's  essays  on  iron  and  steel, 
i.429 

—  on  making  coke,  I.  429 
Horse-oail  stubs,    thttr  employ- 
ment, iL  496 

Hose,  bleaching,  iL  290. 305 
— -  bleaching,  a  test  for,  iL  349 

price  of,  ii.  311 

Hot-bouses  heated  by  steam,  L  618 
Houghsetter,  Daniel,  L  36.  610 
Houses  secured  from  lightning,L93 
the  first  made  of  earth  or 

clay,  ii.  592 
Hudsons  Bay,  climate  of,  L  70 
Human  body,  the  temperature  o4 

L63 
Humboldt  and  Gay  Lussac  on  wa- 
ter, n.  356 
Humboldt  on  enlargingthe  growth 

of  vegetables,  Ii.  344 
Hume  on  the  solution  of  barytic 

salts,  L  339 
Hume's  permanent  white,  L  318 
Hydrate  of  barytes,  L  335 
Hydrates,  u.  362 

—  alkaline,  ii.  27 
Hydraulic  organs  of  the  andeats, 

U.421 
Hydriodate  of  barytes,  i.  352 
Hydriodide  of  carbon,  i.  387 
Hydrocyanic  or  prussic  acid,  i.  388 
Hydrogen  employed  for  the  pro- 
duction of  heat,  L  151 
Hydrometers  for  spirits,  i.  215 
Hydroscopium  of  Synesius,  ii.  370 
Hypasia*s  areometer,  i.  209 

I. 

Ice  employed  in  the  salmon  fish- 


enes.  i. 


117 


basins  used  as  a  receptacle 

for  wine,  i.  121 
cups  of  Mr.  Boyle,  i.  120 
dealers  in  France,  i.  113 


Ice  housf,  useful  to  the  chvwist, 
i.  IIG 

—  -- houses,  their  antiquity,  i.  113 
Mr,  Boyle  1   account 

of.i.  114 
hov  formed  at  lapahau,  i.  1 15 

bow  produced  ID Itaiv.i.  lla 

imported  from  On^eDland,  i. 

113 

makers  at  Benares,  i.  109 

nuking  at  Calcutta,  i.  1 14 

mouDtaina  of  Greenland,!.  Tit 

specific  gravity  uf,  i.  "0 

—  at  Spitsbergen,  i.  /U 


if  gait  n 


i.  IH 


itl^gh( 

prepared   in  the  middle  of 

.ummer,  i.  123 

produced  artiRdally  at  Ben- 
gal, i.  10!) 

produced    expeditiously    by 

ether,  i.  110 

the  want  of,  luppUed,  i.  1 1 1 

Imposts,  excessive,  the  ruin  of  ma- 
□ulocturers,  i.  196 

Improvement  in  bleaching  cali- 
coes, 1.  284 

Improvemeiita  in  calico-prioiing, 
1.20 

in  soap-making,  i.  28 

Incorruptibility  of  charcoal,  i.  424 

India  abounds  in   colouring  tub- 


124!) 


II 


Indian 

ilccl,'ii.  493 

Indigo,  the  Dianagement  of,  for 
calico-printing,  i.  'JACi 

how  deoxidized,  i.  285 

ten,  directiom  Cor  making, 

ii.  332 

vau,  I.  184 

Infusibility  of  charcoal,  i.  415 

Ink  of  the  ancienu,  i.  C3D 

Inkle,  ii.  331 

Instrumrnts,  new  ones  bir  produc- 
ing fire  by  compression,  i. 
102 

Intense  light,  I.  609 

lodnte  of  barytes,  L  352 

Iodide  of  lithium,  ii.  67 

liith  bleaching,  i.  262 

Iron,  an  instance  of  its  increase  of 
weight,  i,  16 


foreign,   irregulariiy  of,  ii. 

48y 

fouodert,  remarks  on,  i,  16 

injurious  in  bleaching,  ii.  39 1 

its   remarkable    uiEnity    for 

silica,  ii.  156 

—  liquor  of  the  calico-printer, 

i,  254 
made  with  wood  charcoal,  ii. 


ore  of  the  firest  of  Dean,  i. 

17 

ore  found  in  Stiria,  ii.  5J6 

ores  abundant,  1. 428 

plates  tinned  with  a  mixture 

of  block  and  grain  tin,  ii. 

560 
red  oxide  of,  for  the  potter, 

ii.  143 

stills,  observations  on,  i.  147 

luperiority  of  that  mode  with 

charcoal,  i.  428 

•  Swedish,  ii.  486 

the  antiquitT  of  its  manufac- 
ture, it.  471 
the  basis  of  many  colours,  i. 

293 

muversallydistTibuted,ii.477 

knowledge  of  making  it  lost 

at  the  Flood,  u.  477 

vitriol,  i.  524 

water-pipes,  how  prevented 

from  oxidising,  ii,  396 

white  prnsBiate  i.f,  li.-'l-S" 

wire,  impoited  from  Holland, 

u.  489 
Ironing,  an  observatioD  respecting. 

Irrigation,  ii.  3?9 

importance  of  in  agriculture. 


696 


INDEX. 


Irrigation,  rewards  for,  in  Persia, 

i.  180 
Isinglass  and  tan,  i.  187 
Isiis  and  Osiris,  i.  ^-il 
Islet's  patent  greeny  i.  294 
Italy,    glass   windows  first  used 

there,  ii.  1 76 
Ivory  palaces,  ii.  89 

J. 

Javelle,  liquor  of,  ii.  291 

Jet,  i.  44/ 

Johnstone,  Dr.,  on  mineral  poisons, 
ii.  584 

Johnstone  ahd  Lambe,  Drs.,  on  the 
poison  of  lead,  ii.  410 

Josephus,  his  account  of  sand  fit 
for  making  gluss,  ii.  J  69 

Jkilius  Caesar,  the  dismay  of  his 
army  on  approaching  Bri- 
tain, i.  6 

Jupiter  Ammon,  temple  of,  ii.  437 

Jurin,  Dr.,  on  weighing  hydrosta- 
Ucally,  i.219 

K. 

Kali  of  Pliny,  ii.  7 

Kaoxin  of  the  Chinese,  ii   100 

Keir,  Mr.,  on  the  imperfections  of 

flint-glass,  ii.  251 
Kelp,  ii.  9 

' weed,  how  cultivated,  ii.  38 

manufacture  of,  ii.  38.  tr-9 

— —  introduced  by  MacLeod,  ii.  38 
■         its  variution  in  price,  ii.  38 

ovens,  ii.  39.  686 

u  prize  essay  on,  ii.  40 

buyers  of  often  deceired,  ii.  40 

a  hint  to  purchasers  of,  ii.  40 

'  improved  by  a^e,  ii.  41 

— —  directions  for  the  analysis  of, 

ii.  41 
~  the  particulars  of  some  ana- 

Ivi'es,  ii.  585 

—  —  in  plass-raakin/j,  ii.  192 
Kilns  for  kelp-buming,  it.  39 
Kircher  on  the  burning-grlasies  of 

Archimedes,  i  85 
Kirwan  on  the  analysis  of  water, 
ii.  379 

—  —  on  climate,  i.  50.  62 


Kirwan  on  the  dififeolty  of  iBCni- 
ducing  improremeiits,  iL 
474 

Klaproth  on  native  s«]p«mmoiitac, 
U.444 

Koran  of  Mahomet  on  water,  ii.  356 

Kunkells*  phosphorus,  i.  128 

L. 

Labelye  on  specific  gravities,!.  218 

Lahontan,  Baron,  oo  citric  acid, 
i.  567 

Lake  of  Geneva,  i.  57 

Lakes,  circulation  of  caloric  in 
them,  i.  60 

— — the  deepest  never  freeze,!.  59 

Lamp-black,  its  manufacture,!. 4 12 

Land,  cultivated  rationally  by  L»* 
voisier, !.  1 1 

^—  how  preserved  !n  Thibet  from 
tornadoes,  i.  142 

improved  by  regular  water- 
ings, ii.  427 

owner,  chemistry  important 

to,  i.  8 

Lapis  lazuli,  ii.  81 

the  eflfect  of  heat  on  its 

colour,  ii.  593 

Lapis  specularis  used  in  Russia  for 
windows,  ii.  175 

Lauraguais,  Count  de,his  improve- 
ments of  porcelain,  ii.  96 

Lava  employed  as  a  glaze  on  earth- 
enware, ii.  1 37 

Lavoisier,  a  chemical  farmer,  i.  11 

—  and  RerthoUet  on  bleaching 

prints,  ii.  340 
^—  his  theory  of  combustion,  L 

7S 
his      discovery     respecting 

combustion,  i.  jy 

on  respiration,  i.  67 

his  analysis  of  sea-water,  iL 

463 
Lead,  an  insidious  poison,  ii.  603 
citrate  of,  i.  5/7 

—  —  fusibility  of,  ii.  620 

glaze,  very  unwholesome,  ii. 

595 

its  use  in  glass,  ii.  189 

improper  for  cider  presses . 

ii.  604 


INDEX. 


697 


Lend,  the  antiqaity  of  its  ute  Id 
glass,  iL  189 

—  vitriol,  i.  525 

Leaden  boilers,  advice  respecting, 
i.  488 

■■  chambers  for  making  sul- 
phuric acid,  i.  483 

— erection  of,  i.  530 

— ,  necessary  appendages 

to,  L  630 

—  cisterns,  caution  against,  ii. 

ii.  409 

—  milk-pans,  ii.  595 
Leather,  duty  on,  i.  25 

—  improvements  in,  L  179 

—  first  made  by  Tvchius,  i.  23 
Leblanc's,  M.,  manulkcture  of  sal« 

ammoniac,  ii.  453 

Lectures,  chemical,  a  national  ad- 
vantage, i.  7 

Lee,  Wm.,  inventor  of  the  stock- 
ing-loom, ii.  306 

Lemere's  account  of  Egyptian  sal- 
ammoniac,  ii.  438 

Lemon-juirc,  an  experiment  on, 
1.  588 

directions  for  the  choice  of, 

i.  585 
'      employed  largely  in  the  navy, 
i.  581 

—  how  adulterated,  i.  586 

—  causes  of  its  deterioration, 

i.  589 
■     how  concentrated  in  Sicily, 
i.  56:^ 

—  how  treated  for  the  navy, 

i.  582 

—  its  strength  ascertained,    i. 

589 

—  methods  of  purifying,  i.  540 

—  methods  of  preserving,  i.  045 
mode  of  sci)arating  the  mu- 
cilage of,  I.  645 

purified  by  freezing,  i.  541 

Lemonadicrs  of  Paris,  i.  122 
Lentulus  Spinter,  i.  245 
Lepidolite,  ii.  66 

Leslie,  his  experiments  on  cooling 
liquids,  i.  144 

—  on  tliy  capacities  of  bodies 

for  calonc,  i.  61 4 
Lewis,  Dr.,   his  experiments  on 
days,  ii.  106 


Lewis,  Dr.,  his  method  of 

specific  gravities  L  226 

his  notes  on  Newmann,  i.  16 

*—  on  the  making  of  accurate 

weights,  i.  207 
on    tiie  specific  gravity  of 

metallic  alloys,  i.  2ii2 
Liege  process  of  making  sal-ammo> 

niac,  ii.  452 
Lier-pans,  ii.  187 
Light  and  heat  produced  by  cook 

pression,  i.  101 
colours  of,  i.  75 

—  decomposed  by  the  diamond, 

L367 

Lignum-vitie,  its  produce  of  char* 
coal,  i.  409 

Limb,  the  loss  of  one,  occasioned 
by  antimony,  i.  14 

Lime  anciently  employed  in  bleach- 
ing, ii.  259 

—  burniiie,  a  hint  respecting, 

ii.  367 

^-^- burnt  by  means  of  inflam- 
mable gas,  i.  105 

citrate  of,  i.  577 

employed  in  bowking  cali- 
coes, ii.  315 

employed  in  crown-glass,  iL 

192 

in  agricultiu^,  i.  10 

its   quality,  very  important 

for  making  glass,  iL  211 
■     its  use  to  soapmakers,  iL  10 

lactate  of,  ii.  29 

Limc-mortar,  i.  617 

Limestone,  magnesian,  L  10 

Linen  cloth,  its  anticjuity,  i.  245 

Linens  of  Holland,  ii.  264 

Linen-board  of  Ireland,  its  regu-^ 
lations,  ii.  330 

Linen,  the  difficulty  of  bleaching, 
ii.  270 

Liquor  silicum,  ii.  32 

Lister,  Dr.,  on  ancient  edge-tools. 
L16 

—  on  the  manufacture  of  steeL 

ii.  484 
Lithia,  ii.  66 

sulphate  of,  ii.  67 

— *—  muriate  of,  ii.  67 
— —  nitrate  of,  ii.  67 

—  carbonate  oC  ii.  67 


698 


IHOBX. 


Lhluuiiiy  iL  66  ^ 

oxide  of,  ii.  66 
Litmus  papery  its  uses,  iL  44 
little,  Mr.  Daniel,  on  iron  and 

fteel,  iL  495 
lixivium,  its  derivadoo,  ii.  4 
Loadstone,  i.  3 
■  ■       remarkable  one  found  in  De- 

yonshire,  i.  605 
Lodmess,  i.  59 
J^ogvood,  how  prepared  for  the 

dyer,  ii.  359 

—  interdicted  by  Elizabeth,  i. 

310.  632 
London  bleaching  liquid,  iL  290 
London  manufactory  of  sal-ammo- 
niac, ii.  457 
London,  mean  temperature  of,  L 

56 
London,  Mr.,   his  tmparatus  for 
ascertaining  the  weight  of 
fluids,  i.  236 
London  plate  glass-house,  ii.  232 
Lowprice  of  calico-printing,  L309 
Lowitz,  his  directions  for  procuring 
large  crystals  of  atric  add, 
L559 
hb  directions  for  purifying 
salts,  L  422 
^—  on  artificial  cold,  i.  125 
— ^  on  the  purification  of  salts, 

L421 
Loysel,  his  observations  on  glass- 
making,  ii.  243 
— •  on  the  sand  proper  for  glass- 
making,  ii.  201 

—  on   the   specific    gravity  of 

glass,  ii.  251 
■     on  the  construction  of  cru- 
cibles, ii.  244 

—  on  wood-fuel,  i.  148 
Lucas,  his  patent  edge-tools,  ii. 

534 

his  steel,  capable  of  being 

magnetised,  ii.  542 

Lungs,  on  their  construction,  i. 
65 

Lustre-ware,  ii.  143 

Lydiatt  on  the  warping  of  edge- 
tools,  ii.  512 

Lye,  alkaline,  how  prepared,  ii.  10 

Lye-burnt  calicoes,  ii.  300 

Lye  of  Javellc,  ii.  289 


Ljmphediicta  of  the  eye^  iL431 
Lyno  tandy  iL  184 

If. 

Mac  DooaU,  Lord,  a  great  kdp 

grower,  H.  38 
Mac  Chvgor,  the  Scotch  bleacher, 

iL280 
Madiine,  curious  one  in  Himgary, 

1.101 
—  for  cutting  tin  plates,  n.  555 
Macquer*8  arsenical  salt,  fi.  23 
Macrobitts  on  some  edge-toob  of 

anfi(]inty,  iL  478 
Madder,  cahEvaiiofi  of,  L  182 
■  ■  process  in  caUoo-printiiig^  L 

276 
•— —  its  properties,  i.  276 

roots,  grinding  of,  L  294 

— *-  two  dolours  contained  in,  i 

283 
Maddered  goods,  hcyw  cleared,  fi. 

332 
Ma^^  those  suspected  of,  fenacri j 

tried  by  water,  iL  421 
Magnena,  dtrate  of,  L  578 

'  its  use  in  porceUdo,  iL  159 
■'  sulphate  of,  promotes  veg^ 

tation,  i.  10 
Magnesian  limestone,  L  10.  281. 

608 
Miuran,  Monsieur,  i.  53 
Malate  of  barytes,  i.  352 
Malic  acid  procurable  from  lemon 

J'uice,  i.  545 
le  glass,  the  discoverer  of, 
executed  by  Tiberius,  ii. 

171 
«— -  a  subsequent    inventor    of, 
imprisoned    by   Richelieu, 

ii.l71 
Malting  of  barley,  i.  32 

remark  on,  ii.  368 

Mammoth  cave,  ii.  583 
Manganese,  citrate  of,  i.  578 
— -  its  use  in  glass,  ii.  190 

■     residuum,  ii.  343 
—  would  accelerate  vegetation, 

iL344 
the  action  cf  its   oxide  in 

purifying  flint  glass,  ii.  598 
»-^  whence  procured,  U.  341 


INDEX.                                             699                  J 

Manner  of  printiDg  calicod,  i.  370 
Maniel's,   ^r  Robert,  pateal  for 

Mercury  first  frozen  by  art  iit  Ox- 

ford, i.  1-23 

maLing  glass  with  coal  fuel. 

froien  in  Russia,  i.  69 

ii.  182 

and  tin,   umolgam  of,  used 

for  mirrors,  iLMi 

i.  193 

ManufKtorin  heated  by  iteam,  i. 

plate  glus.ii.  210 

173 

Metals  afrMted  by  chanue  of  at- 

 of  iteel  in  EDgland,  ii.  487 

mospheric  teniperalure,  i. 

613 

the  water,  ii.  369 

asccrlMned  by  their  specific 

ManufMture  of  ciowB  dMa  Wljhly 

gravity,  i.  206 

of  printers"  types,  ii.  506 

increase  of  wdght  in.  i,  79 

Manufacturers  of  England  prover- 

 melted  at  the  distance  of  40 

bial  for  enterpriie.  i.  196 

feet,  i.  87 

miitry,  t.  14 

phenomena    in    burmng,   i. 

79 

the   consequenee<    of   their 

purity  of,  i.  624 

Metallic  alloy   that  will    fuse  at 

Maourel,  laUoe  and  eurthf,  1.  10 

202,  i.  224 

Matcet,  Dr.,  on  sulpburet  of  car- 

 aUoys  cannot  be   estimated 

bon,  i.  390 

by  their  tpeciftc  grarity,  L 

Mnrgraaf  on  ctilamiDe,  i.  36 

222 

arts  of  the  ancient  Uriloiu, 

Mariner-s  compass,  i.  3.  605 

iL48l 

Mariniu  Ghetaldus  on  specific  gr*- 

baths,  ii.  614 

vitie,,  i.  2(M 

baths  for  cutlera,  ii.  619 

tables    in    the    pUtc    glut 

vily.  i.  204 

works,  iL  232 

Mannor  metallicum,  1.313 

oxides,  i.  608 

Man,  tartariied  tincture  of,  «.  26 

employed  in  potters 

Martial  pyrites,  no  w  used  in  making 

glase.  ii.  139 

sulphuric  add.  i.  642 

Mflscagnine,  i.  622 

specific  grarily,  i.  2LNi 

Matter  indestructible,  i.  80 

Metalloids  in  the  alkaUes.  iL  64 

Means  to  be  adopted  for  purifying 
water,  ii.  384 

Method  of  detectiogb«Jlyblc«hed 
linens,  ii.  603 

Meat  effectually  preserved.  1.  418 

Mcxia,  PcUr,  i.  394 

the   process   of  (reeling  at 

ThiW,i.ll6 

Miine,  Patrick,  esq.,  u.  278 

Milton  on  water,  ii.  355 

Medical  diipute,  an  account  of,  i. 

Mine  at  Upton  Hoe,  it  34) 

12 

Mineral  alkaU,  ii.  37 

electricity,  i.  89 

Minerals,  anulpis  of,  i.  8 

Medicine  dependent  upon  chemis- 

 the  Emperors  oollectioo  oft 

try,  i.  1 1 

i.425 

Miners'  lamp.,  history  of,  1.  12? 

MelUlite,  i.  4t>6 

safety  lamp,  i.  43 

Memoir  on  vegetable  colours,  ii. 

their  confidence  in  the  safety 

369 

Ump,  i.  137 

MephUio  enginM.  ii.  345 

Mi,iesofAnKleMrk.l.32i 

Mcicurj .  citrate  of.  \.  578 

Minisb,  his  patrol  mclhDd  of  mak- 

—      torneoui,  i-  S26 

700 


IND£X. 


Mirrors,  l«rpr«  one*  cait  by  The- 

vart,  ii.  180 
"     ■  of  isinglass  employed  by  the 

ancient  inhabitants  of  North 

America,  ii.  599 
—      plain  and  concave,  i.  87 
Mixture  of  fluids*  i.  2'25 
'     -  of  some  fluids  will  prodace 

combustion,!.  1U3 
■■■■     of  sulphuric  acid  and  water, 

i.225 
Mixtures  of  ardent  spirits,  i.  225 
Molasses,  purified,  i.  418 
Moirs  cabinet  of  minerals,  i.  426 
Molybdate  of  barytes,  1.  352 
Moore,  Mr.  Samuel,  on  the  colour- 
ing artificial  gems,  i.  423 
Mordants,  chemical,  i.  19 
■         explained,  i.  258 
■■        howapplied  to  calicoes,!.  268 
-— —  used  in  maddering,  i.  276 
Morgan  on  the  colours  of  light,  i.  75 
Morocco  leather,  i.  26.  609 
Mortar,  the  best  to  be  used  for 

chemical  furnaces,  i.  616 
'  '    of  the  ancients,  i.  617 
Moses,  Mr.,  his  collection  of  an- 
cient vases,  ii.  594 
Mother-waters  of  citric  acid,  i.  555 
Mountainous    districts  improved, 

ii.  429 
Muhammed,  M.,  on  Persian  steel, 

ii.  5,38 
Murdoch,  Mr ,  first  employed  coal 

gas  for  illumination,  i.  381 
-— —  rewarded  by  the  Royal  So- 
ciety, i.  383 
Muriacit  of  Werner,  i.  525 
Muriate  of  barytes,  i.  34 1  ■ 

directions  forosing, 

i.360 

first    employed    by 

Crawford,  i.  358 
of  lime,  i.  125 

injurious  to  cloth,  ii. 

2i^8 

acts    injuriously  in 

bleaching,  ii.  318 
— —  of  potash,  produced  by  glass- 

makers,  ii.  213 
— —  of  soda,  ii.  451 

of  tin,  accident  in  making,  ii. 

368 


Muriate  of  tin  used  in  dyeing  yel- 
lows, i.  301 

Murray,  Dr.,  his  analyus  of  sea- 
water,  ii.  463 

Muschenbroekfhis  table  of  s] 
gravities,  i.  205 

Mttshet  on  the  preparation  of  chir- 
coal,  i.408 

—  Mr.,  on  woots,  ii.  434     • 
Musical  water-instruments,  iL  420 
^ —  wire,  u.  489       " 
Myrobalans  employed  in  dyttog^  L 

254 

N. 

Natbnal  manufactures,  ii.  494 
Native  barytic  salts,  i.  320 
— —  sal-ammouiac,  ii.  444 
■■  sulphuric  acid,  i.  466 
——materials,  great  importance 
of  employing  in  the  coun- 
try, i.  641 
Natron,  ii.  37 

,  %yptian,  i.  526 

Natural  history,  the  importanoe  ol 

its  study,  ii.  594 
Nature,  a.  deviation  from  its  usual 

course,  i.  60 
Nausicaa  and  her  companions,-  ii. 

262 
Needles  of  Cleopatra,  iu  61 1 
Neri  on  glass,  i.  23 
Nero  s  cups  of  glass,  ii  239 
Neumann  on  the  varieties  of  char^ 

coal,  i.  410 
Newfoundland,  climate  of,  i.  56 
Newton,  Sir  Isaac,  his  burning  mir- 
ror, i.  88 

—  his  conjecture  respecting  tiie 

diamond,  ii.  189 

—  his  fondness  for  chemistry, 

17  _ 

—  his  opinion  of  the  cause  of 

chang^e  of  colour  in  edge 
tools,  ii.  509 

—  on  specific  gravity,  i.  203 

—  his    conjectures    respecting 

water,  i.  203 
Nicholson  on  tempering  steel,  ii. 
607  ^     ^         ' 

Nicholson's  areometer,  i.  210 

improvement     in    grinding 

edge  tools,  ii.  534 


XNPEX. 


701 


Nitrate  of  Iron,  I.  278 

-  of  silver,  i.  587 

Nitre  employed  to  obtain  potash, 
ii.  18 

■  first  employed  for  produciDg 

cold.i.  1*18 
'■        its  uie  in  makinflr  fflasi,  ii. 

190.211 
'■       its  use  in  making  coloured 

gla;s,  ii.  i?50 
— -  the  method  of  refining,  i.  178 

native  of  Molfetta,  i.  627 

Nitric  acid,  proposal  for  concen- 
trating, ii.  364 

'  acid    employed     in    calico 

printing,  i.  297 

■  acid  employed  in  purifying 

clay,  ii.  153 
Nitrum,  or  Natron,  ii.  5^^ 

known  to  the  ancients,  ii.  6. 

583 
Nobles  of  Venice,  i.  196 
Nottingham  black  glaxe,  ii.  139 
Number  of  operations  in  bleaching, 

ii.  328 
■  of  plates  tinned  by  one  man 

in  a  day,  ii.  566 
Nuns-thread,  U.331 


O. 


Obelisks,  Egyptian,  i.  16 

—  of  porphyry,  ii.  611 

—  statues,  &:c.  of  porphjrry,  ii. 

479 

Obercamp,  Mr,  of  Jouy,  ii.  304 

Observations  on  the  property 
which  iron  possesses  of  be- 
ing hardened  and  softened 
at  pleasure,  ii.  505 

Odin  mine,  i.  455 

Oil  and  coal  gas,  comparative 
value  of,  i.  378 

•»— <-  baths  for  tempering  edge- 
tools,  ii.  619 

■  heated,  employed  in  refining 

sugar,  ii.  607 

■  its  effect  when  used  for  har- 

dening steel,  ii.  513 
— «-  its  use  in  the    northen  re- 
gions, i   143 
■  merchants,  i.  182 

of  Titriol  by  the  bell,  i.  474 


Oil  presses,  management  of,  i.  181 

produce  of  in  burning,  L  7^ 

-  soap,  ii.  587 

Old  iron,  its  reduction,  i.  16 

Old  pottery,  of  great  use  in  the 

manufacture    of   chemical 

vessels,  ii.  597 
Olefiant  gas,  i.  383 
Olfactory  nerves,  ii.  432 
Olive  oi!,  use  of  in  8oap-nuUcing« 

587 
'■        tree,  cultivation  of,  ii.  587 
Operation  of  tinning  iron,  ii.  5G2 
Operations  in  calico-printing,  i.  261 
Opium,    its  effects  counteracted, 

i.  580 
Ores,  metallic,  i.  36 

of  cobalt,  i.  41 

Orkney  kelp,  why  best  for  bottle 

glass,  ii.206 
Ormus,  the  ancient  merchandize  of, 

ii.  467 
■         raised  to  eminence   by  ita 

commerce,  ii.  468 
Oven  girls  of  Germany,  i.  71 
Oxalate  of  barytes,  i.  352 
Oxalis  acetosella,  ii.  23 
Oxalic  acid  from  gum,  i.  643 
Oxides,  metallic,  ii.  140 

• 

P. 

Padding  of  calicoes,  i.  291 
Painting  upon  glass,  ii.  91 
Paisley  thread,  ii.  331 
Pale  blue  dipping,  ii.  319 
Palissy,  Bernard  de,  ii.  90 

his  reply  to  Henry  III.,  ii.  93 

Pallaropoors  of  Madras,  L  255 
Paper-making,  i  38 
Paracelsus,  i.  42 

-  his   improvement  of    phar- 

macy, i.  J 1 
Paralysis  of  the  potter,  ii.  137 
Paris  gardeners,  ii.  429 

lighted  with  oil  gas,  i.  379 

Parker's  burning  lens,  i.  SS 
Parkinson's  printing  machines,  i. 

307 
Parliamentary  representation,  to« 

equality  of  accounted  for, 

i.  457 
Parrot  coal  of  Scotland,  i.  448 
Parting,  business  of,  L  35 


702 


INDEX. 


Fiste  of  the  calico-printer,  i.  268 
Patent  method  of  grinding  pUt»- 

glass,  u.  223 
Patterns,  how  sketched  in  India, 

i.255 
Panli  on  the  barberry,  i.  573 
Paulus  .^gineta,  i.  27 
Pays  de  Vaud,  i.  460 
Pearl-ashy  different  kinds  of,  ii.  186 
■■       prepared,  ii.  20 
Pearl  of  Cleopatra,  i.  33 
Peat,  its  properties  as  fuel,  i.  149 
— •  expense  of  getting  in  Soot- 
land,  i.  149 
— —  in  Cumberland,  ii.  17 

inflamed    spontaneously,   L 

104 

add  of,  Ld99 

Pellatt,  Mr.,  his  memoir  on  glass 

incrustations,  ii.  236 
P^Uetier's  s«9onaceous  liquor,  ii. 

352 
— —  on  muriate  of  barytes,  i.  359 

on  strontites,  i.  343 

■    killed  by  chlorine,  ii.  296 
Pencil,  blue,  process,  i.  289 
Pentateuch,  hooks  of,  i.  246 
Pepys,  hb  apparatus  for  filtrating 

water,  405 
■         on  freezing  mercury,  i.  124 
Perchloride  of  carbon,  i.  385 
Percival,  Dr.,  on  agriculture,  u. 

429 
—  on  lead,  ii.  410 
Pericles  the  Athenian,  i.  195 
Perkins  and  Fainnan*s  improve- 
ment in  engraving,  iL  506 
Perkinses  compression  of  water,  ii. 

362 
Permanency  of  Indian  colours,  L 

256 
Peroxide  of  barium,  i.  337 
Persians,  the  excellence  of  their 

porcelain,  ii.  82 
-^—  their  idea  of  water,  ii.  355 
Perspiration,  phenomenon  of,  i.  72 
Pestre,  Mens.,  interesting  account 

of,  ii.  428 
Petalite,  ii.  66 

Petitot,  John,  of  Geneva,  ii.  91 
Petty,  Sir  William,  on  dyeing,  i. 

18 
Petuntse  of  China,  ii.  100 


Pharmacopceisi, lormalsa of,  L  II 
I^uurmacy  much  indelited  to  P^ 

racilsns,  L  II 
Phials  dried  eztemponuseoosly,  L 

110 
Plulip  of  flUes,  L  1 1 
Philfaipo^  BIr.,  intiodiiced  ■aorocco» 

1.26 
Phillips  and  Lee  of  Manchester,  L 

382 
Phosnida,  glass  works  of,  ii.  168 
Phflsnidans  reduced  commerce  to 

a  science,  i.  250 

traded  to  Britain,  i.  251 

—^  the  most  andentdyen,i  251 
Phosgene  gas,  L  375 
Phosphate  of  barytes,  L  353 
— -»  of  lime,  ii.  135 
— -»  of  soda  and  ammonia,  iL  444 
Phosphoric  matches,  i.  99 
Phosphorus,  its  discovery,  i.  98 

—  may  be  procuredfroiii  urine, 

U.499 

— —  generally  found  in  ateel,  n. 
486 

— —  its  produce  of  acid  by  com- 
bustion, L  80 

Phosphuret  of  barytes,  L  355 

— -^-  of  barium,  i.  356 

of  carbon,  i.  391 

—  of  copper  for  cutting  instru- 

ments, ii.  481 
Piezometer,  ii.  362 
Pig4ron,  its  manufacture,  i.  15 
Pins  first  made  in  this  country,  ii. 
613 
■     the  tinmng  of,  ii.  552 

—  whiteninff  process  of,  ii.  552 
Pint  measure  defined,  i.  586 
Pipe-day  employed  in  calico  print- 
ing, i.  296 

Pipes  for  conveying  steam,  i.  146 
Pit-coal,  remarks  on,  i.  15 

—  a  bad  conductor  of  heat,  i. 

160 
Pit-coals,  variety  of,  L  451 
Pitchey  bog-iron  ore,  i.  524 
Plan  for  getting  the  tin-plate  trade 

into  England,  iL  573 
Planetary  bodies,  i.  51 
Planished  covers,  i.  146 
Plantations,  national,  of  wood  for 

gunpowder,  L  405 


INDEX.                            703           I 

Plnmbi^o,  i.  4ai 

country,  i.  640 

crucible*,  i.  433.  ii.  150 

Wrie.,U.  flS 

it.  Tarious  uses,  i.  436 

of  P^,,  ii.  365 

FUte-Klua,  patent  for,  ii.  179 

its  use  in  America,  i.  433 

Polidote  Virgil,  i.  394 

the  Duke  of  BucVingha:n, 

Polish,  superior,  of  cast-sleel,  li. 

U.  182 

4!)0 

monufnctoriM  oF.  ii.  207 

Polished  steel  covered  with  plati- 

 materials  for  mail i tig,  ii.  209 

made  byblowin(r,ii.^l5.  235 

num,  ii.  540 

Poli.hing  glass,  L  224 

215' 

Poppies    pmployed   In  bleaching. 

employed  by  the  navy,  ii.  220 

the  method  of  RrindinK.  iL 

Porcelain,  an  essay  on.  ii.  73 

221 

made  by  casting,  i.  22S 

of  China  and  Japan,  ii.  SO 

French    eitablinhments   for. 

manufiicture     at     King-to- 

i.226 

Ching,  ii,  80 

origin  of  the  word,  ii.  80 

ii,  225 

the  hiitory  of  its  fint  eito- 

of  Persia,  its  prculiar  pro- 

hliihment, ii.  226 

perties,  ii.  H2.  84 

from  Pontua  in  Asia,  ii.  82 

of  comparativriy  late  manu- 

 a  tariff  of  the  pricei  of,  ii. 

facture  in  liiurope.  U.  8? 
th«  Alt  of,  ttolcD  ttAm  China, 

234 

Platinum,  important  use  of,  i.  134 

ii.  M 

impnrM    great    tenacity   lo 

works  ofSaiony.iL  95 

Meel.  ii.  546 

of  Florence,  n.  95 

in  oxide  employed  in  cover- 

ing earthenware,  ii.  143 

96 

a  singular  use  of,  1.  533 

of  Monipclller,  i!  96 

iw  uie  in  the  safety  lamp,  i. 

manufacture  at  Beriin,  ii.  97 

134 

muriateof,  u.  41 

ofnt  DrMden,ii.97 

used  for  touch-holei.  i.  192 

cabinets  of  at  Ormui.ii    99 

Teiieti  for  aulphuiic  add.  i. 

works  at  Coalporl,  ii.  131 

535 

the  temperatutet  at  which  it 

PUtinuiu  and  sHver.  alloy  of.  i.  224 

shouUi  be  burnt,  ii.  132 

menti,  U.  501 

earth  of  Bandlffeco.  il  159 

on  the    reUtiTc    weight   of 

ii.  163 

grain,  i.  'iOl 

on  the   specific    grarity  of 

of,  u.  16-1 

water,  ii.  414 

his  history  of  the  first  iuven- 

tionof,ii.  164 

tionofgla»,  >i.  168 

of  France,    how    com- 

Ilott, Dr.,  hi*  account  of  sponti- 

posed,  u.  164 

neoua  combustion,  i.  105 

Porosity  of  charcoal,  i.  392-410 

on  turf-cxitting.  i.  150 

Porphyr)-.  11.  hardness,  i.  IG 

obelisks  of,  ii.  fil  1 

^^^^^^^^^^^^^^^^^^1 

704 


INDEX* 


Porphyry,  ancieot  butts  o(  ii.  611 
Portland  ?ase,  U.  86 
Potash,  ii  9 

—  carbonate  of,  ii.  9 

—  Russian  mode  of  makinff,  ii. 

14 

—  preparation  of,  ii.  14 

'         procured  from  burnt  peat,  ii. 

17, 

■  obtained  from  saltpetre,  ii.  17 
•—  nitrate  of,  ii  18 

■      procured  from  pyroligneous 
acid,  ii.  18 
«—  how  prepared  in  Germany, 
ii.  18 

—  its  colour  accounted  for^  ii. 

19 

■  found  in  blood,  ii.  19 

— -  English  manufactories  of,  ii. 
20 

—  acetate  of,  ii.  21 

'         anmionia,  sulphate  of^  ii.  21 
;         antimoniate  of,  ii.  21 

■  antimonite  of,  ii.  2 1 

—  arseniate  of,  ii.  22 

—  arsenite  of,  ii.  22 

—  aurate  of,  ii.  22 

■  benzoate  of,  ii.  22 

—  bibenzoate  of,  ii.  22 

bicarbonate  of,  ii.  22 

—.  binarseniate  of,  li.  23 

■        binoxalate  of,  ii.  23 
biphosphate  of,  ii.  23 

—  bisulpbate  of,  ii.  24 
— -—  boletate  of,  ii.  24 

—  bitartrate  of,  ii.  24 

borate  of,  ii.  24 

camphorate  of,  ii.  25 

—  carbonate  of,  ii.  25 

chlorate  of,  i.  98.  ii.  25 

hyperoxymuriate  of,  ii.  25. 28 

—  chromate  of,  ii.  26 

■  bichromate  of,  ii.  26 

citrate  of,  i.  678.  ii.  26 

— —  columbate  of,  ii.  26 

—  ferrocyanate  of,  ii.  26.  32 

ferrotartrate  of,  ii.  26 

fluate  of,  ii.  27 

gallate  of,  ii  27 

hydrate  of,  ii.  27 

hydriodate  of,  ii.  27 

hvdroguretted  sulphuret  of, 

u.  28 


Pbtasby     hydroAulphuret    of^    H. 

28 
hypophosphite  of,  ii.  28 

■  hypo^lphite  of,  iL  28 

■  iodate  <rf,  ii.  28 
*■  —  lactate  of,  ii.  29 
-■■ '  '  malate  of,  ii.  29 
•—- —  mecouiate  o^  ii.  29 

mellate  of,  ii.  29 

supermellate  of,  ii.  29 

— —  moiybdate  of,  ii.  29 

■  muriate  of,  ii.  30 

■  •       nitrate  of,  ii.  30 

—  nitrite  of,  ii.  30 

—  oxalate  of,  iL  31 

oxychlorate  of,  ii.  31 

—  ozymuriate  of,  ii.  31 

■  phosphate  of,  ii.  31 
— -  phosphite  of,  ii.  31 

—  prussiate  of,  ii.  32 

—  quadrozalate  of,  ii.  32 

■  saclactate  of,  ii.  32 

<- silicate  of,  ii.  32 

~— «  sorbate  of,  ii.  32 

bisorbate  of,  ii.  32 

subcarbonate  of,  ii.  32 

— —  suberate  of,  ii.  33 

Bubphosphate  of,  ii.  33 

— —  succinate  of,  ii.  33 

sulphate  of,  ii.  33 

sulphite  of,  ii.  34 

—  tartrate  of,  ii.  34 

supertartrate  of,  ii.  34 

superoxalate  of,  ii.  34 

—  superphosphate  of,  ii.  34 

biphosphate  of,  ii.  23.  34 

supersulphate  of,  ii.  34 

tartrate  of,  and  soda,  ii.  35 

—  tartrate  of,  and  antimony,  it 

35 
— —  tellurate  of,  ii.  35 
triple  prussiate  of,  ii.  36 

—  tungstate  of,  ii.  36 
— ^  urate  of,  ii.  36 

zumate  of,  ii.  36 

a  test  for,  ii.  45 

■  analysis  of,  ii.  64 

—  when   to  be    preferred    for 

flint  glass,  ii.  246 
-^—  its  affinity  for  wate^t  ii.  366 
Pot-  and  pearl-ash,  ii.  25 
Potassium,  chloride  of,4i.  30 
its  characters,  ii.  61 


INDEX. 


705 


Potassium,  its  metallic  nature,  il. 

64 
— ^  its  properties,  ii.  65 

—  method  of  preserving,  ii.  61 

—  sulphuret  of.  ii.  .'14 

Pott  on  chemical  vessels,  ii.  89 
Potters  of  Yesd,  ii.  S5 
— ^—  ovens,  how  heated  at  Dres- 
den, ii.  97 

moulds,  ii.  1 18 

Mrheel,  ii.  119 

moulds,  a  hint  respecting,  ii. 

121 

—  —  chambers,    an  improvement 

in,  siiggested,  ii.  122 
'        oven,  English,  ii.  124 
— —  kiln,  its  temperature,  ii.  131 
gloss-ovenj,  temperature  of, 

ii.  132 
cream-coloured     glaze,    its 

oomposition,  ii.  133 

glaze,  variety  of,  ii.  134 

^—  printing  press,  ii.  144 

— — •  use  of  chemistry  to,  ii.  164 

—  wheel,  its  invention,  ii  476 
^— •  ovens,  in  the  form  of  a  cylin- 
der, ii.  595 

Pottery,  an  important  desideratum 
in,  ii.  127 

—  for  glass-making,  ii.  244 
its  comparative  durability,  ii. 

130 
'  '    specific  gravity  of  different 
kinds  o^  ii.  129 
Pownal,  Governor,  ii.  75 
Praxiteles,  the  statuary,  ii.  89 
Precious  stones,   analysis    of,    ii. 

156  ^ 

Preparation  of  calicoes,  i.  267 
Pressing  of  woollen  cloths,  i.  187 
Price,  Dr.  James,  the  last  alche- 
mist, i.  606 
Prices  for  bleaching  hose,  ii.  311 
of  iron  and  steel,  ii.  488 

—  of  tin-plate,  ii.  571 
Priestley,  Dr.  Joseph,  i.  43 

on  aerial  electricity,  i  93 

first  decomposed  aaunonia, 

ii.  443 
— —  his  discovery  respecting  tkm 

blood,  i.  13 
— ^  on  stagnant  water,  ii.  408 

VOL.  II.  2 


Priestley,  Dr.,  on  the  growth  of 
vegetable  matter  on  stag- 
nant water,  ii.  388 

the  discoverer  of  ammoniacal 

gas,  ii.  442 

the   discoverer  of  carbonic 

oxide,  i.  372 
Prieur  ou  the  varied  colours  of  po- 
lished steel,  ii.  509 
Principle,  the  living,  in  vegetahlca, 

i.  141 
Printed  books,  method  of  cleaning 

ii.  339 
Printers'  types,  i.  1 7.  ii-  506 
Printing,  invention  of,  i.  3.  i.  606 

silk  handkerchieJfiB,  L  288 

—  press,  ii.  596 
Problem  of  Rouelle,  i.  368 
Process  of  the  ancient  fuUe   ,  iL 
6(M 

of   bleaching  by  sulpburottt 

acid  gas,  ii.  337 

of  bleaching  in  Holland*  IL 

261} 

of  bleaching  in  Scotland,  ii. 

32rt 

for  bleaching  hose,  ii.  305 

for  chintz  work,  i,  302 

of  dressing  hose,  ii.  311 

for  forming  brcMui  glass,  iL 
201 

for  making  cast-steel,  ii.  537 

of    making    plate-glass    l^ 

blowing,  ii.  217 

of  making  sal-ammoniac  in 

Egypt,  it  439 

of  tilting  steel,  ii.  528 

of  welding  iron,  ii.  492 

Proclus,  his   burning  mirrors,    L 

85 
Profit  in  making  steel  ezplained* 

i.  16 
Prometheus,  the  fable  of,  i.  83 
Proof  spirit,  i.  214 
Protochloride  of  carbon,  i.  386 
Proust,  on  china  glaze,  ii.  J  30 

on  tanning,  i.  25 

Prunus  cerasus,  its  gum  extreasely 

nutritive,  i.  647 
— described  by  Vifgil,  i. 

647 
Prussian  blue,  i.  39 


706 


INDEX. 


Prassiate  of  potash,  its  use    in 
printing,  i.  295 

Pmssic  g^,  or  cariraret  of  nitro- 
gen, L  387 

Public    meeting    respecting  gas- 
bleaching,  ii.  283 

Pumice-stone,  iu  19 

— a  glaze  for  pottery,  ii. 

137 

Ptare    water     necessary  to    the 
bleacher,  ii.  398 

Purple  of  the  ancients,  i.  39 

Putrefaction,  vegetable,  i.  10 

Pjrritous  coal,  danger  of  keeping, 
i.  104 

Pyroligneous  add,  i.  398 

-        singular  case  respect- 
ing its  distillation,  i.  402 

tar,  i.  399 

Pyroligtiite  of  alumina,  i.  280 

ofirou,  i.  278 

Pyrometer,  importance  of,  i.  191 

of  Wedgwood,  ii  131 

its  use  in  glass-making,  ii. 

245 

Qnartation,  i.  35 

Queen's  ware,  its  introduction,  ii. 

139 
Quercitron  bark,  i.  186.  277 
Quito,  city  of,  i.  55 

R. 

Rafts   floated  by  earthenware,  ii. 

77 
Ravenscroft,  Mr.,  improved   the 

quality  of  flint-glass,  ii.  182 
Reaumur,  his  discoveries,  i.  196 
his  experiments  on  porcelain, 

ii.  94 

—  on  hardening  steel,  ii.  500 

■  ■  ■  his  pension  for  his  disco- 
veries in  making  steel,  ii. 
500 

—  the  inventor  of  a  new  mode 

of  grraduating   thermome- 
ters, ii.  578 
"  .     his  experiments  on  tin-plate, 

a.  578 


Redaction  of  old  iron,  i.  16 
Refined  tin,  ii.  561 
Refiners,  aqua-fbrtis,  i.  25 
Reservoir  for  water,  constroction 
of,  ii.  374 

—  for  filtrating  water,  iL  385 
construction  of  a  peculiar  one, 

ii.394 

—  of  water,  how  supptied  by  a 
smoke  jack,  ii.  4^ 

Resin,  its  manufocture,  i.  413 
Resist  work,  in  calico-printing,  L 

284 
Respiration,  some  account  of,  L  65 

G7 
Retinasphaltum,  i.  455 
Reussite,  i.  527 
Reverberatory  furnaces,  i.  156 
Rewards    for    manufacturers,    i. 

177 
Rhine  and  Danube  frozen,  i.  53 
Rhodes,    his  important   observa- 
tions on  hardening  steel,  iL 
5^)1.526 

—  on  the  manu&cture  of  razors, 

U.502 
— -  on  the  temperature  of  iron 

and  steel,  ii.  503 
his  frame-bladed  razors,  ii. 

521 
Rhodium    effects    a    remarkable 

change  in  steel,  ii.  544 
Richman,  circumstances  attending 

his  death,  i.  94 
Richter*s  process  of  making  sul- 
phuric acid,  1.  560 
Riedesel,    Baron,   on  muriate  of 

ammonia,  ii.  442 
Rittenhous,   on  the  expansion  of 

wood,  i.  235 
Ritter  on  ice,  ii.  356. 
River  Calder,  ii.  372 
River  sand,  none  but  the  conmioo- 

est  kind  allowed  to  be  used 

in  making  bottle  glass,  ii. 

205 
River  St.  Lawrence,  i.  56 
Rivers,  how  preserved  fluid,  i.  61 
Robertson,  Dr.,  on  clinmte,  i.  56 
Robinson's    experiments    on    the 

gravity  of  water,  i.  207 
Rochelle  salt,  ii .  35 


INDEX,                                             707                  1 

nobk-Hit,  it.  68. 590 

Sage,  his  experiment!  on  charred 

impolic*  of  taxing,  i.  S35 

turf.  i.  I&l 

mountain  of.  in  Sp«in.  ii.  68 

in  Loui-lam.  ii.  68 

on  the  use  of  baryte*  in  pot- 

tery.ii.  162 

Kof,   Mr.,  deiirovfd  by  chlorine 

Sails  of  matting,  i.  244 

eu<.  ii.  2W 
Rocbuct,  Dr..  bii  improTeiupnt  of 

known   to  the   ancients,  ii. 

the  maaufoclurc  of  luiuhu- 

437.  608 

ric  acid,  i.  476 

made  Ht  Qecta,  and  at  Ro- 

hb  character,  i.  477 

setu,  ii.  438 

further  pmicular.  of,  i.  478 

procured  from  loot  in  ^ypt. 

Rulund  .nd  Co.  on  bleaching  by 

ii.439                        ^"^ 

sulphur,  u.  -am 

its  vanou*  use*,  ii.  445 

Roman  briubi  and  tilca.  ii.  74.  7'J 

earthenware,  u.  Wl 

in  Europe,  JL  44? 

furnished  from  the  chimneys 

ii.79 

in  the  metropolis,  ii.  440 

pottery  at  Leeds,  ii.  79 

difficultie*  in  •ublinung  for 

veiielB  of  csrthcoware,  ii. 

sale,  u.  462 

ays.  593 

tbe   advantages  of   making 

Romans,  their  restriction!  of  com- 

from bittern,  ii.  464 

merce,  >.  1 U5 

a  now  source  for  its  produc- 

Romai, Monsieur,  on  the  elwlricid 

tion,  U.  466 

kite.  i.  M 

procured  from   coal-gas,  ii. 

RoueUe  the  younger,  i.  368 
Rowley  Rag,  i.  IStt 

466 

abounds  in  the  lava  of  Vcsu- 

Royal  Institution  galvanic  battery. 

viuj.  ii.  J4i 

Ltd 

tnnkm   at  Grand  Cairo,  ii. 

Royal  nunes  of  England,  i,  469 

441 

Rumford^s  caperin^m  mth  a  re- 

 first  analysed  by  Toamefort, 

ii.  441 

volving  cylinder,  i,  102 

native,  ii.  441 

on  the  density  of  water,  i. 

its   chenucal    properties,   u. 

207 

442 

on  fuel,  i.  147 

improved  French  process  for. 

on  the  nunauemeot  of  fuel,  i. 

ii.  453 

I&l 

on  the  nutritive  property  of 

sition,  ii.  44a 

water,  ii.  358 

procured  from  tutf,  ii.  452 

the  late  Count!  prise  esiay. 

pntent,  law  proceedings  re- 

i.48 

ipecUng.  ii.  4G6 

Sal  de  duobus.  ii.  33 

Sal  eniium,  ii.  33 

8. 

Si.Une  manures,  i   10 

Sallola-soda,  iL  37 

Safely-liunp    of   Sir  H     Davy,  i- 

Sal  rairabile,  ii.  66 

616 

periatum.  ii.  54 

Sand  from  Alum-buy.  U.  185 

drat  ioti-oduced,  i.  131.  127 

a  national  benefit,  i   13.-< 

price  of,  ii.  210 

ea.ay  imitated,!.  138 

of  the  river  Belus,  <1.  210 

its   action    thowii  by  ether. 

how  biofceo  on  thecuDtloenl 

i.  138 

tot  making  glaia,  iL  2(15 

•iz 

1 

^^^^^^^^^^^^^^^^^^H 

708 


INDEX. 


8aad-paper,  new  kind  of,  i.  224 

Sandiver,  ii.  246 

Salt,  its  use  in  horticultare,  i.  41 

—  its  use  to  the  grazier,  ii.  68 

■  the  purest  made  from  lock- 

salt,u.  590 
■■        when  first  made  in  England, 
i.  458 

■  ■  ■      observations  on  the  duty  of, 

1.362 

■  on  the  repeal  of  the  duties 

on,  H.  70 

■  of  lemons,  ii.  23 

—  petre,  i.  612 

— refining,  i.  178 

■  '  when  to  be  employed 
in  glass-making,  ii.  250 

—  mines  of  Poland,  ii.  588 

—  French  methods  of  decom- 

posing, ii.  69 

decomposition  of,  ii.  589 

— ^  depositions    of,    in   various 

parts  of  the  world,  ii.  588 

—  ridue  of  in  Africa,  ii.  588 
— ^  sulphurous  of  Stahl,  ii.  34 

used  in  glazing  stoneware, 

ii.  138 

of  Sylvius,  ii.  21.  30 

—  of  hartshorn,  i.  420 

— —  blisters  in  glass,  ii.  249 
Salts  crystallization  of,  i.  178 

of  barytes,  i.  347 

—  employed  for  the  production 

of  cold,  i.  1 18 
— —  purified  by  charcoal,  i.  41 9 

proper   for    frigorific    mix- 

tures, i.  124 

of  ammonia,  ii.  444 

—  alkaline,  ii.  4. 

indebted  to  \rater  for  some 

of  their  properties,  ii.  364 

of  lithia,  ii.  6^7 

Sapphire,    topaz,    and    hyacinth, 

their  analysis,  ii.  158 
Sasso,  the  hot  springs  of,  i.  527 
Saussure  on  the  gases   absorbed 

by  charcoal,  i.  410 
-^—  on  alumina,  ii.  365 
Saw,  its  invention,  ii.  476 
— ^  makers  of  Sheffield,  ii.  514 
Scales,  directiont  for  the  choice 

of^  i.  207 


Scaliger,  the  memorable,  iL  90 
Scaling-furnace    for    tio-platey  n. 

555 
Scarlet  dye,  discovery  of,  i.  20 
Scheele,  the  discoverer  of  chlorine, 

ii.  275 
— —  on  manganese,  i.  31 3 

process     for    concentrating 

dtric  acid,  i.  643 
ScheSer,  Peter,   the   inventor  of 

printing,  i.  3. 
■■        his  table  of  the  mixtures  of 

tin  and  lead   iialladous,  L 

224 
Schools,  chemical,  in  France,  L  7 
Sdssars,  bow  formed,  iL  497 
Scotch  method  of   bleaching,   iL 

326 

• handkerchief  printing,  i.  298 

Scouring  of  hose,  ii.  306 
Sculptors,  English,  ii.  88 
Sea  salt,  ii.  67 
Sea,  temperature  of,  i.  58 

water,   various  aoaUrsis   of, 

U.463 

wrack,  ii.  39 

Seed-crushers,  i.  181 
Seffuin  on  tanning,  i.  25 
Seleniate  of  barvtes,  i.  353 
Sevres,  porcelam  of,  ii.  96 
Shaw  on  glass-making,  ii.  248 
Shawls  of  the  present  Asiatics,  I 

254 
Shear,  spur,  and  star  steel,  ii.  487 

steel,  how  made,  ii.  488 

Shingle  on  the  coast   of  Sussex, 

ii.  108 
Ship  Ajax  destroyed  by  a  heap  of 

pyritous  coal,  i.  106 
Siberia,  gold  found  in  the  tumuli 

ofii.  610 
Sienna,  clay  of,  ii.  161 
Sightening  in    calico-printing,   L 

269 
Silesinn  thread,  ii.  267 
Silica,  a  native  oxide,  i.  96 
its  quantity  in  flint  glass,  ii. 

246 

and  alumina,  a  remarkable 

difference  in,  ii.  107 
SUicate  of  barytes,  i.  354 
Silk-workers  in  France,  i.  183 


Silk-bleschiog,  ii.  339 
Silver,  rtd  ore  of,  J.  aS7 

citrate  of.  i.  578 

probably  tlio  b«t  metal  ti 

unite  with  itee>,  U,  548 
Singeing' of  ctdicoH,  i.  77-  262.  ii 

3&1 


Smith,  Sir  Junes  Edward,  on  the 

anim  maculatuni,  i.  614 
Snow,  artiildat,  i.  101 

of  Lebanon,  i.  Ill 

Soup,  maDul«ciiire  of,  i.  37 

its  antiquity,  i.  27 

known  to  the  andeot  Romans, 


waste,  i.  608 

decomposed  by  impure  water, 

ii.  381 
loft,  ii.  47 
Soap,  boilers,  i.  109 
shop  found  in  ancient  Pom- 

So^-maken'    rrailuum  imed  iii 
bottle-gW,  ii.  204 

lyes,  i.  28 

Soap-Diaking,French  report  on ,  i.  S7 
Soda,  ii.  4H 

sulphate  of.    used  in  glass- 
making,  i.  i^ 

acetate  of,  ii.  48 

borate  of,  ii,  50 

chloride  of,  i.  S61 

camphorate  of,  ii.  SO 

CBrl)K>naie  of,  ii.  60 

chromatc  of,  ii.  51 

citralo  of,  i.  679.  ii.  fil 

(luate  of,  ii.  51 

hydrate  of,  ii.  61 

hvdroculphuret  of,  ii.  hi 

todaie  ot.  ii.  58 

lactate  of  ii.  62 

malate  of,  ii.  52 

—  mol^bdato  of,  ii.  52 

munate  of,  ii.  S3 

nitrate  of,  ii.  53 

oxalate  of,  ii.  53 

photphate  of,  ii.  54 


Soda,  pbonildte  of.  ii.  64 

B^scnlte  of,  ii.  4S 

benioace  of,  ii.  48 

bicarbonate  of.  ii.  48 

bicarbonate  of,  found 

ii.  49 

silicMe  of,  ii.  63 

iub4>orate  of,  ii.  65 

subcrate  ot^  ii.  55 

succinate  of,  ii.  56 

sulphate  of,  ii  56 

sulphite  of,  ii.  66 

nilphuret  of,  ii.  67 

supertartrate  of,  ii. 

tartrate  of,  ii.  67 

iiingstatc  of,  ii.  57 


native,  ii.  37 

component  parts  of,  ii.  64 

in  soa|>-mBking,  ii.  47 

various  patents  for  procuring 

from  sea-salt,  ii  S8S 
one  reason  for  preferring  in 

slass.makine,  li.  1S4 
why  preferable  to  potash,  ii. 

il4.  245 


makes  harder  glass  than  pot- 
ash, ii.  587 

its  superior  power  in  satu* 

rating  silicn,  ii.  S4S 
Sodium  and  ice  produce  combus- 
tion,!. 103 

protoxide  of.  ii.  62 

iiiett)od  of  preserving,  H.  61 

its  cbaruoteristics,  ii.  63 

— ~  ita  metallic  nature,  ii.  64 
Soft  water,  how  to  be  procured  at 
see,ii  385 

of  consequence  to  the  grower 

offlax,  ii.  399 
Soho  manufactnry.  i.  3SS 
Soils,  traniinosition  of.  i.  B 

sour,  now  iniproved,  i.  10 

Solder,  plumber*!,  d.  663 

Solution  of<at»,i.  17S 

Solvent  power  (H^  water  increased, 

i.  167 
Soot  of  Newcastle  coals,  abounds 

in  sal-ammoniac,  ii.  439 
Souring  with  sulphuric  acid,  ii.  174 


710 


INDEX. 


Spears  formerly  made  of  gold  juad 
silver,  n.  477 

Specific  graTity,  i.  199 

bottle,  i.  208 

■  no  criterion  for  metallic  al- 
loys, L  222 

— —  of  compounds,  how  calcu- 
lated, 1.  226 

^-^-  of  solids,  how  ascertained, 

1.217 
■    calculated  by  the  vrine  pint, 
i.  233 

-^—  how  ascertained  by  decimal 
arithmetic,  L  216 

its  use  in  the  classification  of 

minerals,  i.  205 

its  use  in  various  manufac- 
tures, i.  205 

Speculation  respecting  printing  on 
earthenware,  u.  147 

Spedding,  his  machine  for  pro- 
ducing light,  i.  97 

prat's  History  of  the  Royal  So- 
ciety, i.  18 

Spring-sieve  for  printing,  L  289 

Spring- water,  ii.  372 

on  the  choice  of,  ii.  379 

Spodumene,  ii.  66 

Spontaneous  combustion,  i.  103 

Squalut  canicula  of  Linnaeus,  ii. 
459 

Stafibrdshire  potteries,  antiquity 
of,  ii.  99 

Stahl  on  bleaching  woollens,  ii. 
337 

on  chemical  decompositions, 

ii.448 

Standard  of  weights  and  measures, 
i.200 

Starch-making,  i.  39 

States,  true  policy  of,  i.  457 

Statues  of  porphyry,  i.  16 

of  Isis,  i.  249 

Steam,  its  latent  caloric,  i.  72 

-*—  comparative  bulk  of,  i.  73 

on  conducting  it,  i.  146 

engine,  i.  6 

engine  boilers,  i.  618 

— ^  chests  of  the  calico-printer, 
i.271 

pil)€8,  i.  417 

—  cooking  apparatus,  i.  417 


Steam  applied  in  Finnace  to  the 

purposes  of  distillatioii,  L 

640 
Steam  bleaching,  iL  335 

.' economy  of,  iL  336 

laboratory  at  Apothecaries' 

hall,  u.  605 
Steatites  in  earthenware,  ii.  128 

of  Cornwall,  iL  159 

Steel  works,  i.  16 

of  the  ancients,  L  16 

cast,  the  making  of,  L  15 

the  profit  of  its  manufacture, 

L16 

made  by  digesting  wrought 

iron  in  fluidcast-iroDy  iL  484 

for  magnets,  ii.  486 

blistered,  iL  487 

varieties  of,  ii.  487 

—  varies  in  its  time  of  acquiring 

rust,  ii.  489 
— —  altered  remarkably  by  the 

blueing  process,  ii.  510 
— ^  springs,  iL  510 

of  Damascus,  ii.  525 

made  with  animal  charcoal, 

ii.515 

—  drills,  mode  of  hardening, 

iL  513 

injured  in  tilting,  ii.  528 

its  chemical  diflerence  from 

iron,  ii.  536 
combined  with  alumina,  ii. 

543 
improved  by  a  small  addition 

of  silver,  ii.  543 
improved  by  a  small  addition 

of  platinum,  ii.  544 
and  chromium,  allov  of^  iL 

547 
St.  Gobin  glass  manufactory,  iL 

218 
Stephens,  Mr.,parliamentary  grant 

to,  ii.  14 
Still,  economical  one,  i.  174 
Stills,  on  setting,  L  152 
Stocking-loom  mvented,  iL  306 
Stodart,  Mr.,  on  wootz,  ii.  494 
en  the  Damascus  blades,  iL 

525 
— ^  and  Faraday  on  some  allop 

of  iron  and  steel,  ii.  542 


Slone-coal,  i.  450 

Stone  bauiiners  of  ancteitt  Perua, 

ii-  472 
weapons  of  the  ancients,  ii. 


47^ 


i.  129 


lustnunents  of,  ii.  6(H) 

w»rc  retorts,  method  of  pre- 

•emng,  ii.  69/ 

ware,  in  durabililj,  ii,  90 

Iiow  glued,  ii.  138 

B  pra|KMul  for  ioiproving.  ii. 

Scoiirbridac  day.  i.  166 

.Slove  of  the  ai^-rcfiner,  L  193 

Sioving  of  printed  calicoes,  i.  184. 

370 
Strabo,  1.  i49 
Sinw-hleschiag,  iu  340 
Stronciles    confounded   with   bft- 

ri-in,  i.  34.1 
and  bur)'lca,  how  diitinguiih- 

ed,  i.  313 

saita  of,  i.  343 

power  of  taturatinc  addt,  i. 

31.1 
irivesaKsrlct  colour  to  flame, 

i.344 

citrate  of,  i.  579 

Slub-niuld  converted  to  bsr-jron, 

ii.  496 
Siibtimotion  of  tal-amntoniac,  U. 

450 
Substance*,  their  varied  power  in 

conduccinK  caloric,  I.  149 
Subttnnlive  and  adjective  coloun, 

i.258 
Succinnte  of  barytcs,  i.  354 
Sugar,  i.  610 

refining,  i.  34.  174 

new  mode  of  bailing,  L  35 

rcBncd  by  cbnrcod,  i.  419 

ofmUk.  II.3S 

Sulphate  of  potash,  i.  S9 

of  alumina,  i.  fi£l 

of  itnintitea,  i.  5S3 

ofcobali,  i.  533 

of  copper,  i.  fi23 

ofbarjle*.  i.  315.  5« 


;ii 


Sulphate  of  baryte^,  employed  it 
pottery,  i.  317 


of  magnesia,  i-  626.  ii.  451 

of  iron  known  to   Pliny,  i. 

466 

of  iron,  native,  i.  466.  5*4 

of  Ume,  i.  525 

of  lime,  injurioui  to  eolicoe*, 

ii.  303 

of  Mda,  i.  609 

of  toda,  native,  t.  628 

of  M>da  for  gla»4naking,  ii. 


of  bai^'tes  and  > 

pottery,  ii.  11>3 
Sulphur,  a  aiaple   substance,    i. 

469 

whence  procured,  i.  469 

ita  comlnintion,  i.  470 

process  oTpreparing,  i.  470 

iti  purity  bow  Mc«srtained, 

i.47S 

Tariety  of,  i,  478 

combustion  of,  i.  473 

its  nature,  i.  471 

flowers  pf,  i,  47? 

roll,  i.  472 

liver  of,  ii.  34 

employed  early  in  bleaching 

i  4ti5 
bleaching,  the  antiquity  of, 

ii.  XtM 
Sulphurct  ofborytcs  i.  318.  356 

of  cupper,  1,  472 

of  carbon,  i.  300 

of  iron.  iL  372 

of  lithium,  ii.  67 

Sulphuric  Hcid,  on  essay  upon,  i. 


465 
-  niaimliu'turv. 


-  manufacture  eitnhlished  in 

tKrroinahun,  L  476 
•  h)  inanulaclure  in  other  parts 

of  England  and  inScotland, 


712 


IMDEX. 


Bolphurlc  Mad  known  to  Gec^ge 

i^cda,  in  1642,  i.  467 
■■        first  described  by  I>ornea8i  i. 

467 
..^  its  early  manufmctare,  i.  467 
*—-  its  maniifiRCture  in  Germany, 

L468 
— —  how  manufactured  at  Bleyl, 

i.  468 
^-— formeriy  made  in  glass,  i. 

474 

Dr.  Ward's  patent  for,  i  474 

when  first  made  in  leaden 

chambers,  i.  476 
— — -  its  manufacture  established 

in  London,  i.  480 

■  —  large    establishment   of    at 

Battersea,  i.  481 

— —  its  sale  greatly  esrtxnded  by 
its  introduction  in  bleach- 
ing, i.  483 

modem  method  Of  making, 

i.484 

— —  directions  for  concentrating, 
i.  486 

— — -  cautions  respecting,  i.  487 

-— —  antidote  against  its  poison, 
i.493 

■  account  of  an  acddent  from 

swallowing,  L  494 

..  its  distinguishing  characte- 
ristics, i.  494 

i— —  its  affinity  for  water  shown, 
i.  494 

effect   of   its  mixture  with 

water,  i.  495 

its  retention  of   caloric,    i. 

496 

. a  caution  in  mixing  with  wa- 
ter, i.  498 

■  method  of  forming  a  table  of, 

i.499 

uses  of  the  table,  i.  503 

-^—  determined    by  its    specific 

gravity,  i.  206 
-^ —  native,  i.  528 

formed  in  urine,  i.  528 

properties  of,  i.  489.  493 

—  how  purified,  i.  489 

anecdote  respecting  its  ma- 
nufacture, i.  510 

'  a  caution  respectinff  diluting 
it  in  winter,  i.  511 


8uUphmic  acid,  esperioMiits  cm  k» 
freeiiii^,  i.  oil 

its  chemical  affinities,  L  513 

■         its  boiling  point,  L  613 
~  variations  in  its  specific  gra- 
vity, i.  513 
■■    ■  ■  a  tabular  view  of  these  wh 
ations,  L  514 

—  method  of  constructing  this 

table,  L  516 
its  law  of  expansion  ^ffef«nt 

finom  that  of  water,  i.  617 
its  strength  how  ascertained 

byMr.  Dalton,  L517 
«— table  of  its  bolting  point  at 
various  dm-ees  of  density, 
i.518 

—  its  various  uses,  i.  519 

—  the  true  theory  of  its  forma* 

tion,  i.  531 

doubts  respecting  its  proper 

dilution    for   decomposing 
the  citrate  of  lime,  i.  646 
'  ■  formerly  made  from  sulphate 
of  iron,  L  642 

—  when  first  tised  in  bleaching, 

ii  274 

amount  of  its  consumptioo, 

i.  503 

—  its  use  in  calico-printinir.  i. 

266  K     — s, 

its  composition,  i.  490 

a  tedious  process  when  made 

from  copperas,  i.  469 
Sulphuric  salts,  decomposition  of. 

i.  191 

a  law  respecting,  i.  529 

decomposed  by  carbon,  i.  367 

Sulphurous     acid     employed    in 

bleaching,  ii.  33/ 

gas,  i.  490 

Sun  not  the  source  of  caloric,  L  51 
Supercarburetted  hydrogen,  i.  383 
Surface  bleaching,  ii.  317 
Surplices  of  the  Egyptian  priests. 

ii.  261 
Swords  of  Damascus,  iL  523 

in  the  fifteenth  century,  iL  484 

Sword-^nakers  of  Damascus  car- 

i-ied  oflr  to  Persia,  it  523 
Sylvius,  salt  of,  ii.  21 
Synesius,  his  letter  to  Hyuatia.  i. 

201.  ii.  370 


Ifplien,  a  ntW  oM  liiT  drtwipg 
fulphuric  acid,  i.  634 


Tabk  of  carnt  wcighti,  i.  2-J9 
of  carrits   Tor  fluid*   lighter 

thui  water,  1  '^l 
(if  cunits,   with  the  cam- 

iponding    weights   of   the 
•       i,233 


I.  196 


2a5 


ot  the  iptdfir  grarity  of  the 

melab,  i.  'M 
of  the   specific  gmvitiei  ot 

sulphuric  add,  >.  50-l 
of  the  temperature*  produced 

by  ihe  mixture  of  aulphi 


i,  41*6 


iragent*   ascd   to  detect 
impurities  in  water,  ii.  3t<3 

of  the  aolutioii  of  wlls,  ii.  1 M 

of  Ihe  proportion*  of  carbon 

in  iron  and  steel,  ii.  636 
ot  metallic  teniperatures,  W. 


Tacitus,  hii  acxount  of  the  aand 

ofthe  river  U«lai,ii.  16!t 
Tallow,  choice  of,  i.  ^ 

method  of  purifying,  i.  30 

employed  in  wearing    cali- 

CDFi,  i.  264    ii.  J2I 
used  \o  tinning,  it*  tempera- 
ture gf  great  conieqnence, 
ii  5fi7 
Tamarind  aboundi  with  citric  acid, 

i.  5?3 
Tan,  artificial,  i.  24 
~ —  iti  affinity  for  gelaline.  1.  2A 

old,  first  eni|>loyed,  i.  S5 

prepared  for  fuel,  i.  149 

• —    ill  arpuation  by  mariate  of 
tin,  i.  \»6 


EX.  713 

Tan,  precipitated   by  idnglmi,   L 

m 

Tanacetum  of  Linnffius,  ii.  I& 
Tanners  of  9>outhwark,  i.  l?:) 

their  refuse,  i.  25 

Tanttin,  artificial,  i.  3>I3 
Tanning,  i,  23 

ofhidcn,!.  179 

Tar,    pyroligneout,  propoied  ht 

colouring  gUti,  L  423 
Tartar,  ii.  24 

a  dispute  respecting,  i.  12 

cream  of,  ii.  34 

soluble,  ii.  35 

emetic,  ii.  36 

Tartftrian  antiquities,  account  of, 

ii.  611 
Tartrate  of  barytes,  i.  354 
Technical  t^rms  In  glass-making, 

ii.  191 

—  In  the  manufactuie   of  tin* 

plate,  ii.  667 
Teeth  of  files,  lv>w  preserved  in 

tempering,  il.  S18 
Telescopes,  specula  for,  ii.  563 
Temperature,  remarha  on,  i.  47 

. the  term  defined,  i.  48 

naiuril  and  artilicial,  i.  &0 

its  importance  in  manuftc- 

lares,  i.  176 

its  importance   in  chrmicMl 

proceFies,  i.  1/6 
attention  ti>,  of  universal  uti- 
lity, i.  1!»3 

to  be  attended  to  in  taking 

the  specific  gravities  of  b^ 
dies,  i.  236 

proper  for  maddering,  \.  2S3 

at  which  tin-plate  it  made,  ii. 

660 
tome  ancient  modes  of  re- 
ducing, 1.  1 10 
Tempering  edge-tools,  ii,  4t<6.  500 

of  saws,  ii.  614 

swords,  ii  622 

Temple  at  Ephesus,  ' 
Tennant's  memoir  oi 

i.  367 
Tennant,  Mr.,  hit  patent,  ii.  293 
his  bleaching  process,  ii. 


714 


INDBX 


Tern  ponderoaa,  L  313 
Test  papers^  L  590 

for  pure  watcr>  iL  381 

— —  for  water  oontainiiig  iron,  u. 

382 
— for  water  oontaimng  selenitef 

1L389 
— ^  for  citric  acid,  i.  586 
Thales,L42 

Theodore,  Elector  Paladne,  L  49 
Theophrastos,  Eresius,  L  396 
Theory  of  calico-printiiogy  i.  260 
Thermometer,  its  use  to  manufoo- 

•  tm«rs,  i.  180 
Thermometers,  the  different  ones 

described,  i.  64 
—  proposed  by  Kirwan,  i.  64 

■  ■         —  Dr.  Murray,  i.  64 
Therart,   his    patent  for  casting 

glass  mirrors,  ii.  179 
Thomson,  Dr.,  on  phosphuret  of 

caroon,  i.  391 
■■        on  znmic  acid,  i.  354 
I         on  some  facts  respecting  ci- 
tric acid,  i.  6% 
-  on  the  production   uf  am- 
monia, iL  456 
Thread,  ancient, its  fineness,  ii.  262 
— >  bleaching,  ii.  348 
Tilting  of  steel,  iL  628 
Tin  an  object  of  merchandize  to 

the  Phcsnidans,  i.  251 
J—  refining  and  working  of,i.  627 
.^ —  a  remark  on  it3  specific  gra- 
vity, L  225 
.  ■■■-  its  affinity  for  several  other 
metals,  ii.  551 

■  ■— '  and  zinc,  alloy  of,  ii.  551 

I  -■  amalgam  of,  used  for  closing 
the  mouths  of  bottles,  u. 
552 

— ■  and  copper,  alloy  of,  used  for 
various  purposes  of  manu- 
facture, ii.  552 

— —  and  copper,  alloy  of,  used  by 
the  ancient  Romans  in  their 
brass  coinage,  ii.  552 

and  lead,  alloy  of,  ii.  553 

.— -  and  antimony,  alloy  of,  ii.  553 

in   Saxony  discovered  by  a 

Cornish  miner,  ii.  576 

— —  trade,  carried  from  Bohemia 
to  Saxony,  ii.  576 


Tin  trade  introdnoed  into  Sazctay 
by  a  Romiah  priest,  iL  576 

— ^  foil,  ii.  553 

pyrites,  of  Cornwall,  ii.  561 

nunea  of  ErBgebir;g,  u.  571 

plate,  an  Essay  on,  ii.  551 

plate,  process  of  making:,  E. 

554 
plates  steeped  in  a  mixture 
of  muriatic  acid  and  water, 
ii.556 

— — made     near    Awe    in 

Saxony,  iL  573 

ori^  of  the  art  of,  ii. 

571 

made  by  Yarranton,  iL 

575 

— ^ establishments  belong- 
ing to  the  Duke  of  Saxony, 
u.  5/5 

—  — — manufacture  in  Mon* 
mouthshire,  ii.  578 

— —  — ^  manufacture  of  great 
national  importance,  L  579 

Tincal,  ii.  55 

Tincture  of  Indian  iron,  L  1 1 

Tinning,  process  of,  ii.  560 

Tombs  of  the  ancient  Peruvians,  ii. 
480 

Tools,  steel,  of  the  ancients,  L  16 

Tools,  iron,  of  the  Hebrews,  ii, 
475 

Trial  pieces  of  the  potter,  ii.  125 

Trona,  ii.  49 

Troughton,  on  the  expansion  of 
steel,  ii.  525 

Trudaine,  Monsieur,  his  burning- 
glasses,  i.  86 

Tschimhausen,hisbuming.glasses, 
i.  85 

Tungstate  of  barytes,  i.  354 
Tunics  of  the  Babylonians,  ii.  261 
Turf  in  the  Scottish  Isles,  i.  149 

employed  as  fuel,  i.  149 

Turkey-red,  i.  283 

discharge  work,  i.  297 

Twaddle's,  areometers,  L  215 
Type-founders,  L  1 7 
Tyre,  famous  for  its  purple  colour. 
L  251 


u. 

Ul(nmarii>«,  ii.  81 

(Jreiiiiim,  citrate  of,  i.  680 

Urate  of  baiTtea,  i.  354 

Utc,  Dr..  his  lecturri,  i,  7 

on  the  mixture  of  fluid),  i. 

225 
on  the  fbrmatioQ  of  aulpburic 

acid,  i.  490 
Urine  employed  in  luanufactiires. 


Vnlangin,  Dr.,  on  perspiration,  i. 

Vatenlia,  Lord,  his  travcli  in  lodtB, 

i.  G19 
VulcriiH  Fluceuii,  i.  24S 
Vuu  Braam  on  trariiUDg  rooms  in 

China,  i.  615 
on   the  Chinese   method  of 

wntering   iheir    lands,    Ii. 

4-2R 
VuuJcimDnde  on  the  mRnuractiiie 

of  bnyonets,  ii.  4t<3 

on  making  steel,  ii.  486 

and  others  on  crucibles,  ii. 

IM 
Vdn  Helmond  on  charcoal,  i.  408 
Vnriegatrd  clotbi.  of  SIdon,  i.  346 
h-makinj;,  i.  3'J 


Varnish   ^m   pyroUgneous  add, 

i.  401 
Varro,  Marcus  Terentius,  ii.  4 
Vaiei  of  antiquity,  ii.  75 
number  (^  in  Herculaneum, 

Vats  ofthe  soap-boiler,  i].  10 
Vuiiquelin  on  the  tamarind,  i.  573 
bis  tiLble  of  sulpburlc  acid,  i. 

508 

an  error  in  tbU  table,  i,  609 

on  the  melliblp,  i.  456 

bis  analysis  of  tlessian  cru* 

ciblcs,  ii.  153 
on  the  earth  of  pyroracteis, 

ii.  131 
on  pottery,  ii.  103 


on  steel,  iL  4S(> 

V^«table  putrefactioo,  i.  10 
oils  recommended  to  the  ca- 
lico-wearer, i.  264 
Vegetables   decompose   water,  ii. 

367 
Venetian  houses,  i.  437 
Veniun,  how  preserved  in  Siberia, 

i,  117 
Vessels  For  dyeing  scarlet,  i,  252 
Villalpandus,  Kuplista.  i.  204 
ViUette's  concave  rairror,  i.  86 
Vinegar-making,  i.  32 

Egyptian,  i.  33 

itj   use   in    preventing    the 

combuttion  of  wood,  i  466 

«lo»M,i.  610 

its  effect  in  hardening  iron, 

iL50l 

raris.i.  177 

Buggeitionsrcspertjng.i,  177 

Virgil  on  the  juice  of  the  citron,  i. 
647 


Vogler  on  the  use  of  sal-ammoniac 
in  dyeing,  ii.  466 

Volcanoes  productive  of  sal-am- 
moniac, ii.  441 


Wake-robin  nsed  in  bleaching,  ii. 

263 
Walker,  Mr.,  bis  first  attempt  to 
freeir  mercury,  i.  123 

his  apparatus  fiir  ditto,  L  124 

Walls  of  Ibe  Romans,  iL  74 
curious  ones   in  the   High- 
lands, ii,  155 
Walter  de  Colecester,  ii.  88 
War-chariots  employed  in  Bgypt, 
ii.  613 

of  the  Britons,  ii  482 

Ward,   Dr.,   the   first    maker   of 

sulphuric  acid,  i.  473 
Warlike  inslrumeota  of  Copper,  il. 
612 


716 


IKDBX. 


Wafter^  hard  prderaUe  to  soft  fior 
land,  i.  9 

■  a  curious  change  in  its  den- 

sity, i.  61 

■  ■»  its  latent  caloric,  L  66 

— — -  ceases  to  boil  in  a  certain 

atmosphere,  i.  72 
-^—  made  to  boil  by  a  revolving 

cylinder,  i.  102 

■  expedient  of  the  caravans 

for  cooling,  i.  109 
— ^  how  procured  at  Hudson's 
Bay,  i.  142 

—  preserved  by  oil  from  freez- 

ing, i.  143 
-»—  the  datum  for  detennimng 
specific  gravities,  i.  207  - 

—  the  weight  of  a  cubic  foot  of, 

i.207 
-»—  weight  of  the  wine  pint,  i.  503 

—  pnnfied  by  charcoal,  i.  420 

—  impregnated  with  carbonic 

acid,  i.  418 

—  expansion  of,  ii.  605 
'—  its  expansive  force,  L  613 
-»—  a  new  table  of  its  expansion 

and  contraction,  ii.  417 
an  essay  on,  iL  355 

—  opinion  of  the  ancients  re^ 

specting,  ii.  355 
•^—  its  composition,  ii.  356 
— ^  decomposition  of,  ii.  357 
.         decomposed  in  chemical  pro- 
cesses, ii.  358 

—  formed  by  the  electric  spark, 

ii.358 

■  its  use  in  cutting  logwood, 

ii.359 

-»—  its  various  effects  in  chemi- 
cal processes,  ii.  360 

— -—  eusts  in  four  separate  states, 
ii.  361 

-— —  exists  in  chemical  combina- 
tion with  bodies,  ii.  361 

■  unites  with  bodies  in  definite 

proportions,  ii.  362 

condensed  by  quick  lime,  ii. 

363 

■  parts  with  caloric  in  uniting 

with  salts,  ii.  363 

—  of  crystallization,  ii.  364 

■  its  action  on  plaster  of  Paris, 

ii.  365 


Water  necessary  in  fermentaldoii, 

U.368 
-»—  decomposed  by  metals,  iL 

368 

—  produced  in  some  chemical 

processes,  ii.  369 

' its  purity  often  of  great  con- 
sequence, iL  369 

comoarative  goodness  of,  u. 

to  be  chosen  by  its  specific 

gravity,  ii.  380 

purified  by  distillation,  iL  384 

purified  by  filtration,  ii:  384 

purified  by  the  operations  of 

nature,  ii.  385 

purified  by  the  growth  of 

vegetables,  ii.  3& 
contuning  selenite  purified, 

ii.  389 
how  purified  from  iron.  iL 

391 
purified  by  exposure  to  the 

atmosphere,  ii.  396 
importimce  of  drinking  such 

as  is  pure,  ii.  403 
how  purified  in  China,  iL  404 

—  how  procured  by  the  Hin* 

doos,  ii.  404 
French  method  of  filtrating, 

ii.  405 
supply  of  for  ship-board,  ii. 

of  the  Rhone,  ii.  407 

cisterns  of  lead,  ii.  409 

its  various  properties,  ii.  410 

—  specific  gravity  of,  ii.  411 
its  unchangeable  nature,  ii. 

411 
its  solvent  power,  ii.  412 

variation  in  its  specific  gra- 

vity, ii.  412 
^—  its  solvent  power  influenced 

by  its  specific  gravity,  n. 

413 
quantity  requisite  to  dissolve 

sundry  salts,  iL414 
curious  phenomena  respect- 
ing, ii.  418 
a  singular  effect  of,  in  malring 

boUlcglass,  ii.  419 
-^—  methods    of    raising    from 

great  depths,  ii.  425 


INDEX. 


717 


Water,  advaOUges  deriTed  from,  ii. 

431 
^-—  its  effect  in  perfecting  sight, 

taste  and  smell,  ii.  431 
its  influence  in  cbcnucal  ope- 
rations, ii.  433 

some  of  its  peculiar  uses  in 

the  arts,  ii.  433 

pipes,  of  earthenware,  ii.  692 

of  antiquity,  ii.  78 

of  iron,  ii.  374 

protected,  i.  145 

treatises  on,  ii.  375 

Water-ordeal  of  superstitious  ages, 

ii.  421 
Water.bellows,  ii.  422 

used    in    Sweden    and 

Italy,  ii.  422 

—  employed  in  drawing   coals 

from  the  earth,  ii.  423 
Waterings  of  the  Paris  gardens,  ii. 

429 
Waters     producing    inflammable 

gas,  i   106 
■  how  rendered  hard,  ii.  370 

of  the  baths  in  TuscHny,  ii.  430 

Watson,  Bishop,  on  decomposing 

salt,  ii  69 
his  opinion  of  Yarranton,  ii. 

675 
on  the  specific  gravity  of  pot- 
tery, ii.  129 

on  charcoal,  i.  408 

Watts,  his  experiments  on  fusing 

basalt,  i.  188 
his  exertions    to   introduce 

gas  bleaching,  ii.  279 

hi.H  fire  lute,  i.  165 

his  first  ideas  on  the  steam 

engine,  i.  6 

on  basaltic  columns,  i.  190 

Zealand  madder  i.  283 

Wax,  how  bleached,  u.  338 
how  employed  in  printing,  i. 

287 
Wearmouth  monastery  glazed  by 

foreign  artists,  ii.  172 
Weaver  of  calicoes,  ii.  320 

injudicious  practices  of,ii.320 

Weaving  and  dressing  calicoes  by 

steam,  i.  628 
Weaving,  its  invention,  i.  243.  ii. 

260 


Wedgwood,  Jotiah,  1.21 
Wedgwood,  Thomas,  bb  ezperi* 

ment,  i.  102 
—  bis  pyrometer,  i.  192 

i'aaperware,  i.  317 
lis  imitation  of  the  Portland 

vase,  ii.  86 
'—  his  expedients  for  imprcmng 

earthenware,  ii,  99 
— — -  an  elegant  tribute  to  his  me* 

mory,  ii.  100 

his  Etruscan  vases,  ii.  101 

cream  colour  ware^  ii.  139 

Weighing  hydrostatically,  i.  218 
Weight,  increase  of,  by  oombut* 

tion,  i.  79 
Weld,  a  yellow  dye,  i.  186. 227 
Welding  heat,  ii.  491 

of  iron,  ii.  492 

Well  of  immense  depth  in  Staf* 

fordshire,  ii.  3/1 
Well-sinking,  u.  371 
Westrumb   on   crystallized  dtrio 

acid,  i.  653 
Whale-blubber,  ii.  460  . 

boiler,  described,  ii.  318 

White  cloths,  a  proposal  respect* 

ing,  ii.  350 
Whitening  of    cloths  by  the  an« 

cients,  ii.  257 
Whites,  how  preserved  in  calico- 
printing,  i.  287 
Wickeriley-stone,  ii.  533 
Wiegleb  on  the  manufacture   of 

sal-ammoniac,  ii.  447 

on  wood  fiiel,  i.  148 

Wilson,  Mr.  Daniel,  his  patent  for 

boiling  sugar  by  means  of 

oil,  ii.  607 
Window  or  broad  glass,  ii.  202 
Windows,  method  of  cleaning  in 

Russia,  i.  119 
of  St.  Denis,  when  painted^ 

ii.  174 
the  action  of  double  ones.  t. 

143 
Wine  coolers,  i.  108 
Wine,  an  improvement  in  cooliiy 

proposed,  i.  108 

cut  with  hatchets,  L  64 

Wine-making,  ii.  368 
Wine-pint,  its  capacity,  L  502 
Wire  tor  piano-fortcs,  iL  490 


718 


INBEX. 


Wire  gauze,  its  great  cooling  power, 
il30 

—  workers,  iL  489 
Witherite,  L  3:21 

Witter,  his  accident  with  carbonic 

oxide,  L  374 
Woad  and  indigo,  i.  258 
WoUaston,  Dr.,  his  new  method 

of  freezing,  i.  126 

—  on  the  cutting  diamond,  ii. 

602 

—  on  super  salts,  ii.  24 
Wood-«shes   formerly   employed 

for  plate-glass,  ii.  208 
Wood  burned  in  water,  L  84 

—  converted  to  an  agate,  L  425 

—  fuel  best  for  making  glass, 

iL244 
choice  of,  L  148 

—  in  decaying  decomposes 
water,  ii.  358 

^—'  its  loss  in  charring,  i.  407 

—  of  the  citron,  i.  644 

—  the  kinds  bcsst  for  charcoal, 

i.405 

Woodhouse,  Dr.,  on  the  produc- 
tion of  ammonia,  ii.  462 

Wool,  formerly  to  export  was 
felony,  L  458 

—  of  Spain  and  Portugal,  ii  .376 

—  scourers  in  ancient  Rome, 

iL378 

—  the  antiquity  of  collecting, 

iL260 
Wool-sacks,  why  placed  in   the 

House  of  Lords,  i.  459 
Woollen-cloth  abhorred   by  the 

Egyptians,  i.  249 
manufacture  of  Flanders,  L 

458 
■  manufactures  protected  in 

England,  i.  459 

—  manufactures  of  the  ancient 

Britons,  i.  641 

—  manufacture   improved    by 

the  Romans,  i.  d41 
Woolwich  sand,  ii.  205 
Wort,  boiling  of,  i.  175 
Wootz,  EngUsh,  ii.  543 

—  of  Bombay,  ii.  493 


Worcester  china,  ii.  131 

Worms  of  stills,  i.  174 

Wright,  Rev.  T.,  on  irrigatioD,  L  9 

Writers,  several,  on  bleaching,  ii. 
351 

^—  to  be  consulted  on  the  pu- 
rity of  water,  ii.  382 

Writings  found  in  Herculaneuni, 
I  411 

W>iikyn  de  Worde,  L  606 

Y, 

Yam,  woollen,  scouring  of,  ii.  1*2 
Yarranton,  Mr.  Andrew,  iL  67^ 
his  journey  to  Saxony  to  see 

the  tin-plate  manufactories, 

iL  572 
interesting  account   of  bis 

journey,  iL  573 
his  return  with   the  process 

of  tinning,  ii.  574 

his  various  plans  for  improv- 

'  ing  the  country,  ii.  577 

his  proposed  plan    for  the 

junction  of  the  Thames  and 
Sevam,  iL  577 

planned    docks    for   Dublin 

and  London,  ii.  577 
his  journey  to   Holland  to 

examine    the   linen-nianu- 

factures,  iL  577 
Yellow,  method  of  dyeing,  i.  185 
requires  peculiar  care  in  dvc- 

ing,  i.  277 

Z. 

Zaffre,  i.  41 

Zeno  on  ponderable    substances 

L  612 
Zimmerman  on  the  compression  of 

water,  ii.  362 
Zinc,  L  611 

-  citrate  of,  i.  580 

for  brass-making,  i.  36 

native  sulphate  o£^  L  528 

Zumate  of  bar3rtcs,  i.  354 

Zumic  acid  named  by  Dr.  Thom- 
son, i.  354 


THE   END. 


Pnnted  br  Richard  TViylor, 
Shoe^Une,  London. 


CORRIGENDA. 

Vol.  I.     Page  38,  line  1  of  the  note,  /or  chlorate  irad  chloride. 

—  40,  line  20,^/ar  tartareous  read  tartanc. 

—  65t  line  20,  Jbr  arterial  read  venous. 

66t  line  7,  after  caloric  add  and  is  converted  into  water. 

— ^  79,  line  1 2,  for  incipient  read  slow. 

264,  liM  28,  dele  the  word  Unseed. 

284,  line  7,  for  oxyxnuriate  read  chloride. 

314,  line  20  et  pasfttm,ybr  cauk  read  cawk. 

351,  line  \8,  for  55,5  read  55.8  and  consequently  128.S 

—  352,  line  21,  for  it  is  a  superraalate  read  it  has  an  add  taate. 
354,  line  IS,  Jbr  46.7  insert  47.3 

«—  393,  line  l,jor  non-conductor  retui  conductor. 

422,  line  2  of  the  note,/ar  page  270,  read  pages  165  &  8S7. 

— ^  427,  note  •,  for  page  25,  read  page  3:1. 

470,  line  4,  dele  the  words  slowly,  and. 

520,  tuw  2\yfor  Rabc,  read  Rabcl. 

note  *,  for  page  41  read  page  40. 
— —  574,  line  24,  far  precipitated  from  their  solutions  by,  read  de- 
composed by. 

578,  line  %  for  55.5  read  55.8 

— -  626,  Unc  41,  for  page  63  read  page  59. 

VoL  II.  Page  29,  Une  6, for  saturating  read  decomposing. 

«—  30,  line  S,for  rapidly  read  slightly. 

39,  Une  15,  for  calcines  read  combines. 

44,  line  27,  for  rendered  neutral  read  neutralited. 

«—  62,  line  2,  for  any  read  most. 

■  55f  line  4,  for  super  read  sub. 

— «-    67,  line  10,  for  s^ts  retul  compounds. 

481,  note^tfbr  page  117  read  page  127. 


Works  published  by  the  same  Author. 


The  CHEMICAL  CATECHISM,  with  Tables,  Notes,  Illu- 
strations and  Experiments.  The  Tenth  Edition,  greatly  enlarged, 
and  illustrated  with  New  Engravings.  In  one  thick  volume  octavo, 
price  148.  in  extra  boards. 

The.  RUDIMENTS  of  CHEMISTRY;  iHustrated  by  Expen- 
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Third  Edition,  carefully  corr«ked,  fuid  adapted  to  the  present  State 
of  Chemical  Science.  )n  one  neat  pocket-volume,  price  7s.  boards. 

THOUGHTS  on  the  LAWS  relating  to  SALT,  as  they  affect 
the  Fisheries,  Agriculture,  and  Manufactures  of  the  Kingdom ; 
with  Reasons  for  the  Repeal  of  those  Laws,  arranged  under  distinct 
and  separate  heads.  To  which  is  prefixed,  the  whole  of  the  Author's 
Evidence  given  before  the  Honourable  the  Board  of  Trade  on  the 
tame  sulject.     In  one  volume  octavo,  price  7s.  6d. 

A  LETTER  to  the  FARMERS  and  GRAZIERS  of  GREAT 
BRITAIN,  on  the  Advantages  of  using  Salt  in  the  various  Branches 
of  Agriculture,  and  in  Feeding  all  Kinds  of  Farming  Stock  ;  with 
a  large  Appendix  of  Proofs  and  Illustrations.  The  ^urth  Edition, 
octavo,  108  pages.     Price  2s. 

This  Letter  is  designed  to  explain  the  different  Methods  of  ap- 
plying Salt  to  Land,  so  that  it  may  act  as  a  Manure,  while  it  pro- 
tects the  various  Crops  from  the  ravages  of  Grubs,  Worms,  and 
Insects.  Instructions  are  also  given  for  mixing  the  salt  in  various 
proportions  with  the  Food  of  Live  Stock,  so  as  to  promote  their 
mttening,  and  preserve  them  in  health  and  vigour.  A  List  of  the 
Agricultural  Societies  in  England  and  Wales,  and  of  the  Premiums 
offered  by  the  Board  of  Agriculture,  and  the  Highland  Society  of 
Scotland,  for  Experiments  with  Salt  in  Husbandry,  are  contained 
in  the  Work. 


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