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A   DICTIONARY 


OF 


APPLIED    CHEMISTRY 


VOL.  I. 


A    DICTIONARY 


OF 


APPLIED    CHEMISTRY 


BY 

Sib  EDWARD  THORPE,  C.B.,  LL.D.,  P.RS. 

KMSRITUt  PBOrcaSOB  or  CiUIIBAL  OBSmnSI  AMD  MRBOTOB  OW  TBI  OBBMIOAL  LABORATOBtM 

or  THB  nCPBBIAL  OOLLBOB  OP  0CIBBOB  ABO  TBCHKOLQOT,  80UTB   EBBBIBOTOX,   LONDOW  ; 

LaTB  PBZBOIPAL  OP  THB  OOYBBBXBBT  LABORATORY,  AKD  A  PAST  PRBSIDRBT  OP 

TBB  OBBMIOAL  fOOIBTT  ABD  OP  THB  bOClBTT  OP  CHBMIOAL  IBDUBTRT 


A88I8TBD    BY    EMINENT    CONTRIBUTORS 


VOL.  L 


REVISED  AND  ENLARGED  EDITION 


WITH    ILLVSTRATI0N8 


LONGMANS,    GREEN,    AND    CO. 

39  PATBRNOSTER  ROW,    LONDON 

FOURTH  AYSNUK  ft  SOth  STREET,  NEW   YORK 
BOMBAY,  CALCUTTA,  AND  MADRAS 
1921 
All  righf   r€*erv$d  LIBRARY 

UNIVERSITY  OF  CALIFOBtf 
DAVIS 


PREFACE 


The  publication  of  the  present  edition  of  this  work  has  been  delayed  by  circum- 
stances arising  out  of  the  Great  War.  Some  of  those  who  contributed  to  previous 
editions  were  actively  engaged  as  combatants ;  others  were  employed  in  munition 
work  or  in  industries  closely  associated  with  such  work,  and  consequently  were 
unable  to  find  time  or  opportunity  to  revise  their  articles  until  the  conclusion  of 
hostilities.  Some  valued  contributors  were  no  longer  with  us,  and  it  was 
necessary  to  make  fresh  arrangements  in  regard  to  new  writers.  Provision  also 
had  to  be  made  for  additional  articles  necessitated  by  the  development  of  chemical 
industry  since  the  date  of  the  previous  edition.  From  the  fact  that  practically 
the  whole  chemioal  energies  of  the  country  were  concentrated  on  the  prosecution 
of  the  war  it  was  impossible  to  make  rapid  progress  with  the  revision  of  a  work 
of  this  magnitude. 

It  has  become  a  truism  to  say  that  Applied  Chemistry  has  exercised  a  profound 
influence  on  the  character  and  direction  of  the  war.  It  is  equally  true  that  the 
war  has  exercised  a  great  influence  on  Applied  Chemistry.  It  has  led  to  an 
enormous  expansion,  more  or  less  permanent,  of  certain  branches,  both  in  this 
country  and  abroad.  New  products  have  been  made, -new  processes  have  been 
devised,  and  established  methods  have  been  improved  and  extended.  In  spite  of 
the  economic  and  other  evils  which  have  followed  in  its  train,  there  can  be  no 
doubt  that  the  war  will  be  found  to  have  permanently  affected  for  good  the 
progress  of  manufacturing  chemistry  in  this  country,  and  indeed  in  all  English- 
speaking  countries.  Whilst  the  disturbance  and  strain  of  the  past  half-dozen  years 
have  seriously  afiected  the  development  of  pure  science  and  the  output  of  chemical 
research,  Applied  Chemistry  has  been  quickened  in  certain  directions.  The 
financial  and  industrial  collapse  which  has  overthrown  our  late  enemies  will,  it  may 
be  presumed,  tend  still  further  to  accelerate  the  expansion  of  our  own  chemical 
manufactures.  Germany,  for  the  present  at  all  events,  no  longer  holds  the 
supreme  position  in  certain  branches  in  chemical  industry  that  she  enjoyed  prior 
to  1914,  and  it  may  be  doubted  whether,  under  her  altered  social  and  economic 
conditions,  she  will  ever  recover  it. 

It  is  too  soon  to  be  in  a  position  to  chronicle  all  the  results,  as  regards  chemical 
manufacture,  which  have  arisen  from  the  intensive  application  of  chemists  during 
the  past  strenuous  years.  Much  is  of  a  character  that  in  the  present  disturbed 
state  of  the  world  it  would  be  inexpedient  to  make  public.     On  certain  matters. 


148 


▼i  PREFACE. 

indeed,  no  authoritative  information  can  be  obtained.  This  will  explain  why 
manufacturing  detaUs  of  several  new  processes  in  connection  with  munitions  have 
not  been  given. 

The  entire  work  has  been  carefully  revised,  and  so  much  new  matter  included 
that  it  has  been  found  necessary  to  enlarge  it,  and  six  volumes  will  certainly  be 
needed,  and  it  is  possible  that  a  seventh  will  be  required.  It  is  to  be  hoped  that 
in  its  present  form  the  book  may  still  be  considered  as  a  reasonably  adequate 
presentation  of  the  state  of  contemporary  knowledge  concerning  the  applica- 
tions of  Chemical  Science. 

A  list  of  the  contributors,  with  the  titles  of  their  articles,  is  prefixed  to  the 
several  volumes.  Their  names  and  standing  are  a  sufficient  guarantee  that,  as  in 
previous  editicms,  every  effort  has  been  made  to  make  the  Dictionary  a  faithful 
record  of  the  present  relations  of  chemistry  to  the  arts  and  sciences. 


ABBEEVIATIONS 

OP  THE  TrriiES  OP  JOUBNAIiS  AND  BOOKS. 


A.wt6Tm  Chcnt.  J. 
Amer.  J,  Pharm. 
Afntr*  J.  Sci» 
AndL  Fis.  Quim, 
Analyti    .    .    . 
AnnaUn   .    .     . 
Ann,  Ohim.  anal. 

Antt,  Umtn,  • 
Ann,  Fdlsif, .    . 
Ann,  Inst,  Pcuteur 
Ann,  Phynk,     . 
Ann,PJw»ique  . 
Annali  Chim,  Appl 
Apoih,ZeU.  .    . 
Arch,  Pharm,     . 
AtH  B.  Aecad, 
Lined  .    .    . 
BentL  a.  Trim.  . 


Ber,  DeuL  pharm, 

Get 

Bied,  Zentr,  .    . 

^^'4}»Cn£m.  J, 

^Bioehem.  Zeitsch 

BT8W6T9  </•       •      ■ 

BvU,  Imp,  In»t 
Bull.  Soc.  ckim. 
Chem,  Ind.    .    . 
Chem,  News  .    . 
Chem,  Soc,  Proe. 
Chem,  Soc.  Trans, 
Chem,  Weekblad 
Chem,  ZeU,  .    . 
Chem.  Zentr.     . 
Compt.  rend. 

DingL  poly.  J.   . 
FOrber-ZeU. .     . 
FHlck.  a.  Hanb. 
FrdL    .... 
QoMM,  chim.  ital. 
Helv.  Chim.  Acta 
Jahrb.  Min. ,    . 
J,  Amer,  Chem.  Soc 
J,  Bd.  Agtie.     . 
J.  Franklin  Inst. 
J.  Ind.  Eng.  Chem 
J.  Inst.  Brewing 
J.  Pharm.  Chim. 
J,  Phys.  Chem. 
J,  VT.  Chem. 
J.  Buss.  Phys,  Chem 

Soc  .... 
/.  Soc  Chem.  Ind 
J,  Soc.  Dyers.    . 
J.  Tokyo  Chem.  Soc 
J,  Washington  Acad 

Sei 

KoUoid  Zeitsch. 
Met.  d  Chem.  Eng 
Min.  Mag.    .    . 
MonatsK  .    .    . 

F'hamSt  J.     .    , 
Pharm.  ZeU. 


American  Chemical  Journal. 

American  Joamal  of  Pharmacy. 

American  Joamal  of  Science. 

Analee  de  la  Socledad  Espaiiola  Fisioa  y  Quimica. 

The  Analyst. 

Annalen  der  Ghemie  (Justus  Liebig). 

Annales  de  Ohimie  analytique  appUqu^e  k  rindostrie,  k  T  Agriculture, 

k  la  Pharmacie  et  4  la  Biologie. 
Annales  de  Ohimie. 
Annales  des  Falsifications. 
Annalee  de  I'lnstitut  Pasteur. 
Annalen  der  Physik. 
Annales  de  Physique. 
Annali  di  Ohimica  Applicata. 
Apotheker-  Zeitung. 
Arohiy  der  Pharmaide. 

Atti  della  Beale  Acoademia  del  Lincei. 
Bentley  and  Trimen.    Medicinal  Plants. 
Berichte  der  Deutschen  ohemischen  Qesellsohaft. 

Beriohte  der  Deutschen  pharmazeutischen  Gesellschaft. 
Biedermann*s  Zentralblatt  fiir  Agrikulturohemie  und  rationellen 

Landwirtschafts-Betrieb. 
The  Bio-Chemical  Journal. 
Bioohemische  Zeitschrift. 
Brewer's  Journal. 
Bulletin  of  the  Imperial  Institute. 
Bulletin  de  la  Society  chimique  de  France. 
Chemische  Industrie. 
Chemical  News. 

Journal  of  the  Chemical  Society  of  London.    Proceedings. 
Journal  of  the  Chemical  Society  of  London.    Transactions. 
Chemisch  Weekblad. 
Chemiker  Zeitung. 
Chemisches  Zentralblatt. 
Comptes  rendus  hebdomadaires  des  Seances  de  TAoad^mie  des 

Sciences. 
Dingler's  polytechnisches  Journal. 
Farber-Zeltung. 

Fliickiger  and  Hanbury.    Pharmacographia. 
Friedlander's  Fortschritte  der  Teerfarbenfabrikation. 
Gazzetta  chimica  italiana. 
Helvetica  Chimica  Acta. 

Neues  Jahrbuch  fiir  Mineralogie,  Geologic  und  Palaeontologie. 
Journal  of  the  American  Chemical  Society. 
Journal  of  the  Board  of  Agriculture. 
Journal  of  the  Franklin  Institute. 
Journal  of  Industrial  and  Engineering  Chemistry. 
Journal  of  the  Institute  of  Brewing. 
Journal  de  Pharmacie  et  de  Chimie. 
Journal  of  Physical  Chemistry. 
Journal  fiir  praktische  Chemie. 

Journal  of  the  Physical  and  Chemical  Society  of  Russia. 
Journal  of  the  Society  of  Chemical  Industry. 
Journal  of  the  Society  of  Dyers  and  Colounsts.   ^ 
Journal  of  the  Tokyo  Chemical  Society. 

Journal  of  the  Washington  Academy  of  Sciences. 

KoUoid-Zeitschrift. 

Metallurgical  and  Chemical  Engineering. 

Mineralogical  Magazine  and  Journal  of  the  Mineralogical  Society. 

Monatshefte  fiir  Chemie  und  yerwandte  Theile  anderei  Wissen- 

Bchaften. 
Pharmaceutical  Journal. 
Pharmaceutische  Zeitung. 


ABBREVIATIONS  OF  THE  TTTLBS  OP  JOURNALS  AND  BOOKS. 


PMl,  Mag.    .    .    . 
PhU.  Trans. .    .     . 
Phot.  J.    ,    .    .    . 
Proc.  Boy.  Soc. 
]^roc.  itoy.  Soc.  Edin. 
Bee  t/rav.  chim. .    . 
Trans.  Faraday  Soc 
Zeitsch.  andL  Chem. 
Zeitsch.angew.  Chem. 
Zeitsch.  anorg.  Chem. 
Zeitsch,  NaJir. 

(jeMissm,  •    •    • 
Zeitsch.  iJjffentl 

Chem 

Zeitsch.  physikal. 

Chem 

Zeitsch.  physiol. 
Chem 


PhiloBophioal  Magazine  (The  London,  Edihbargh  and  Dablin). 

PhiloBophical  Transactions  of  the  Royal  Society. 

Photographic  Jonrnal. 

Proceedings  of  the  Royal  Society. 

Proceedings  of  the  Royal  Sociel^  of  Edinburgh. 

Reoenil  des  travaoz  chimiques  des  Pays-Bas  et  de  la  Belgique. 

Transactions  of  the  Faraday  Society. 

Zeitschrift  fiir  analytdsche  Ghemie. 

Zeitschrift  fiir  angewiandte  Ghemie. 

Zeitschrift  fur  «norganische  Ghemie. 

Zeitschrift  fiir  Untersuchong  der  Nahrongs-  und  GenussmitteL 

Zeitschrift  fiir  5fientliche  Ghemie. 

Zeitschrift  f  Or  physikalische  Ghemie,  Stochiometrie  und  Verwandt- 
scliaftslehre. 

Hoppe-Seyler's  Zeitschrift  fur  physiologisohe  Ghemie. 


LIST   OF   CONTEIBUTOES 

TO  VOLUME  I. 


Dr.  B.  F.  ARMSTRONG,  P.LO.,  F.R.S.  (Afeasra.  /.  Orosfield  A  Sans,  Ltd.,  Warrington), 
[AmyiiAns;  Bbbad.] 

Dr.  G.  H.  BAILEY  {Ths  British  Aluminium  Company,  KirUochleven,  N.B.),  [ALUMonuM, 
Alums,  axcd  AiiUHcnuM  Compounds.] 

0. 0.  BANNISTER,  Esq.,  F.LO.,  A.R.S.M.  {Messrs.  Edward  Biley  d  Harboard).  [Ahtimony  ; 
Bismuth  (Mstai.i.ubq;  of).] 

Dr.  GEORGE  BARGER,  M.A.,  P.R.S.,  Professor  of  Chemistry  in  relation  to  Medicine  in 
the  University  of  Edinburgh,  [AcoNiTiinB  and  thb  Aconitb  Alkaloids  ;  Adbxnalinb  ; 
Aloxs  ;  Absca  Nut  ;  Abistoloohinb  ;  Bstainbs  ;  Bboom  Tops.] 

Dr.  G.  BARGER,  M. A,' F.R.S.,  and  Dr.  F.  L.  PYMAN.    [Alkaloids.] 

G.  8.  BLAKE,  Esq.,  AR.S.M.,  B.Sc,  M.I.M.M.    [Babium  ;  Calcium.] 

J.  S.  S.  BRAME,  Esq.,  F.I.C.,  Professor  of  Chemistry,  Boyal  Naval  College,  Qreenwich,  8,E, 

[ACETTIiSNB,  COMMEBCIAL  APPLICATIONS  OF;   BOILBB  InCBUSTATIONB  AND  DEPOSITS.] 

JOHN  F.  BRIGGS,  Esq.  {British  Cellulose  Co.,  Derby).    [Acetic  Anhydbidb.] 

HAROLD  BROWN,  Esq.,  The  Imperial  Institute,  London.    [Balata.] 

Dr.  J.  C.  CAIN,  Editor  of  the  Journal  of  the  Chemical  Society,  London,  [Aniline  ,*  Aniline 
Salt;  Azo-CoLOUBiNa  Mattbbs;  Benzene  and  its  Homologues.] 

W.  H.  COLEMAN,  Esq.    [Cabbolio  Acid.] 

Dr.  HAROLD  G.  COLMAN,  F.LC,  Formerly  Chief  Chemist  to  the  Birmingham  Corporation 
Qas  Dept.    [Ammonia.] 

JAMES  OONNAH,  Esq.,  B.A.,  B.Sc,  F.LC,  Deputy  Principal,  The  Government  Laboratory, 
London.    [Absinth;  Absinthin;  Abbinthol;  Abback;  Bbandt.] 

Dr.  W.  DITTMAR,  F.R.8.    [Balance.] 

Dr.  ARTHUR  £.  EVEREST,  F.LC.    [Anthooyanins.] 

Dr.  ARTHUR  J.  EWINS.     [Caffeine  and  the  Alkaloids  of  Tea,  Coffee  and  Cocoa.] 

THOMAS  FAIRLEY,  Esq.,  F.LC.     [Aspibatobs.] 

Professor  C.  S.  GIBSON,  O.B.E.,  M.  A(Oxon.  and  Cantab.),  M.So.(Mano.),  F.LC.    [Amyl.] 

Dr.  W.  D.  HALLIBURTON,  F.R.C.P.,  M.R.C.S.,  F.R.S.,  Professor  of  Physiology,  Univer- 
sity  of  London.    [Bile;  Blood;  Bone.] 

Dr.  J.  T.  HEWITT,  M.A.,  F.R.8.,  Emerihu  Professor  of  Chemistry ,  East  London  College, 
University  of  London.    [Acbidine  Dyestuffs.] 

J.  W.  HINCHLEY,  Esq.,  A.R.S.M.,  F.LC,  Professor  of  Chemical  Engineering,  Imperial 
College  of  Science  ana  Technology,  South  Kensington,    [Autoclave.] 

JOHN  HOLMES,  Esq.,  F.C.S.,  The  Qovemmmt  Laboratory,  London.    [Alcoholometby.] 

Dr.  JULIUS  HUEBNER,  M.So.,  F.LC,  Director  of  Dyeing  and  Paper-making  Departments, 
Manchester  Municipal  College  of  Technology.    [Bleacbinq.] 

H.  W.  HUTCHIN,  Esq.  {The  Cornish  Consolidated  Tin  Mines,  Canibome).    [Absbnic] 

HERBERT  INGLE,  Esq.,  B.So.,  F.LC,  late  Chief  Chemist  to  the  Transvaal  Agricultural 
Department.  [Albubonb  Gbatns;  Almond;  Apple;  Apbicot;  Abgin-inb;  Abbowboot; 
ABsnoHOKB ;  Ash  ;  AspAifiious ;  Avocado  Peab  ;  Banana  ;  Babley  ;  Batatas  ;  Bean  ; 
Bebt-boot;  Betainb;  Bilbbbby;  Blackbebbibs  ;  Bban;  Bbead  Fbuit;  Bbussbls 
Bfbouts;  Buckwheslt;  Cabbaoe.] 


X  LIST  OF  CONTRIBUTORS. 

Dr.  R.  LESSING,  Consulting  Chsmist,  London.    [Bbomihs.] 

Dr.  JULIUS  LEWKOWITSCH,  M.A.,  P.G.L  (Bevised  by  O.  A.  MiUhsll,  Esq,,  B.A.,  F.I.C.) 
[Adipookbx;  Anacasdium  Nut;  Abachis  Oil;  Bassia  Oils;  Bbh  Oil;  Bohs  Fat; 
BOBNKO  Tallow;  Brazil  Nuts;  Oaoao  Buttbb.] 

Dr.  IDA  SMEDLEY  MaoLEAN.    [Balsams.] 

JOHN  J.  MANLEY,  Esq.,  M.A.,  Magdalen  College,  Oxford,    [Balance.] 

Dr.  F.  A.  MASON,  M.A.(Oxon.)  {The  British  Dyestuffs  Corporation,  LtdX  [Aoetals  • 
Aobttlbnb;  Aldehyde;  Azims  (Sufpl.).]  *  ' 

CHARLES  A.  MITCHELL,  Esq.,  B.A.,  ¥1,0.  (Messrs.  Beaufoy  d  Co.,  London),  [Acetto 
Acid  ;  Acobn  Oil  ;  ASbatbd  ob  Minebal  Watebs  ;  Anacabdium  Obientalb  *  Beech- 
nut Oil;  Behenio  Acid.]  ' 

T.  S.  MooBE,  Esq.,  M.A.(Ozon.),  B.So.(Lond.),  Professor  of  Chemistry,  HoUoway  College, 
[Amines;  Amino  Acms.] 

Dr.  G.  T.  MORGAN,  O.B.E.,  A.R.C.S.,  F.LC,  F.R.S.,  Professor  of  Chemistry  in  the  Univer> 
sity  of  Birmingham.      [Acidimetby    and    Alkalimetbx;     Analysis;     Antimonials 
Obganio;  Absenicals,  Obqanic]  ' 

Professor  A.  G.  PERKIN,  F.R.8.,  F.I.C,  Department  of  Colour  Chemistry  in  the  University 
of  Leeds.  [African  Mabiqold  ;  Aloabbobin  ;  Alkanbt  ;  Annatto  ;  Abchil  ;  Asbabg  ; 
Atbanobin;  Babbatic  Acid;  Babwood;  Biqnonia  Tbcoma;  Bbazil  Wood;  Buck' 
thobn;  Butea  Fbondosa.] 

Dr.  F.  MOLLWO  PERKIN,  F.LC,  Consulting  Chemist,  London.  [Bleotboohemioal 
Analysis.] 

Professor  W.  H.  PERKIN,  LL.D.,  F.R.S.,  and  Dr.  ROBERT  ROBINSON,  F.LC,  F.R.S. 
{of  the  British  Dyestuffs  Corporation  {Huddersfield),  Ltd.),  cCssisted  bv  Rev.  F.  H.' 
GORNALL,  M.So.    [Alizabin  and  Allied  Coloubino  Mattebs.] 

J.  A.  PICKARD,  Esq.,  B.So.,  A.R.CS.,  F.I.C.    [Aoetins  ;  Allyl.] 

Dr.  F.  L.  PYMAN,  Professor  of  Technological  Chemistry  in  the  University  of  Manchester,  and 
in  the  Manchester  Municipal  College  of  Technology.  [Bebbebinb  ;  Bbbbebine  and  the 
Bbbbeuib  Alkaloids.] 

Dr.  HENRY  ROBINSON,  M.A.    [Anesthetics.] 

Sir  THOMAS  K.  ROSE,  D.So.,  F.I.C,  The  BoyaX  Mint,  London.    [Assaying.] 

Dr.  WALTER  ROSENHAIN,  F.R.S.,  The  Naiiondl  Physical  Laboratory,  Teddington. 
[Amalqam;  Annealino.] 

L.  JL  SPENCER,  Esq.,  M.A.,  F.G.S.,  Mineral  Department,  British  Museum.  [Abbasiteb; 
Adamite;  Aeschynite;  Aqalite;  Aoalmatolitb ;  Agate;  Alaite;  Allantfe;  Alsto- 
nite;  Alum  Shale;  Alunite;  Alunogbn;  Amazon-Stone;  Ambeb;  Amblygonitbi; 
Amethyst  ;  Amfangabeite  ;  Anatase  ;  Ancylitb  ;  Andalusite  ;  Andesine  ;  Andesite  ; 
Andobitb  ;  Anglesite  ;  Anhydbite  ;  Anebbitb  ;  Apatite  ;  Aphthitalite  ;  Abagonite  ; 
Abdenntte;  Abgentite;  Abgybodite;  Asbbstos;  Ataoamtfe;  Autunitb;  Azinite; 
Azubite;  Baddeleyite;  Baeumlebite;  Bakebite;  Babytes;  Babyto-CaiiOite  ; 
Basal f;  BastnIsite;  Bauxite;  Bbckeltte;  Bellite;  Benitoite;  Bebyl;  Bebze- 
ltantte;  Bbbzblite;  Betafite;  Bismite;  Bismuthinite  ;  Bismutite;  Bloedite; 
Blomstbandine ;  Bloodstone;  Blue  Ibon-Eabth;  Bog  Ibon  Obb;  Bole;  Bobagite; 

BOBAX ;  BOBNITE  ;  BOBONALBOOALCITB  ;  BOSTONTFE  ;  BOUBNONITE  ;  Bbaunite  ;  Bbazilite  ; 

Bboohantite;    BBdOGEBiTE;    Bbucite;    Buhbbtonb;    Bxtilding    Stone;    Buntkup- 
PEBEBz;  Calamine;  Calayebite;  Caloitb.] 

Dr.  ARTHUR  L.  STERN,  F.I.C  {Messrs,  Bass,  BateUff  d  Gretton,  Ltd.,  Burton-on-TrenCi 
[Bbewing.]  • 

GEORGE  STUBBS,  Esq.,  CB.E.,  F.LC,  The  Government  Laboratory,  London.    [Buttbb.] 

Dr.  M  A.  WHITELY,  O.B.E.,F.LC.,A.R.C.S.,  Lecturer  on  Organic  Chemistry,  Imperial  College 
of  Science  and  Technology,  8.  Kensington.  [Adenine  ;  Alanine  ;  Allantoin  ;  Alloxan  ; 
Alloxaktin;  Abginase;  Abginine;  Aspabagine;  Abpabtio  Acid.] 

Dr.  OTTO  N.  WITT,  Polytechnic,  Charlottenburg.  [Azinbs  :*  with  an  Addendum  by  Dr. 
F.  A.  Mason.] 


DICTIONABY 

OF 


APPLIED    CHEMISTEY. 


AAL,  AX,  ACH,  AFCH.  Native  names  for 
the  roots  of  Morinda  iinctcria  and  M,  dtrifoUa, 
employed  in  Tariona  parts  of  India,  under  the 
general  trade  name  of  Snranji,  as  a  dyesti^ff, 
more  especially  for  dyeing  reds,  purples,  and 
ehooolates. 

ABACA.  A  species  of  fihre  derived  from 
Musa  iextUia  (N^),  obtained  mainly  from  the 
Philippine  Islands,  and  used  in  the  manu- 
facture of  mats,  cordage,  Ac.  It  is  also  known 
under  other  names,  including  'Manilla  hemp,* 
'Menado  hemp,'  'Gebu  hemp,*  '8iam  hemp,* 
and  *  White  rope.'  Less  valuable  fibres  are 
obtamed  from  other  species  of  Musa,  such  as 
M.  sapieiUum  (Linn.),  xhe  banana  and  plantain, 
which  yield  banana  fibre  and  plantain  nbre. 

ABAMONE.  Trade-name  for  a  pharma- 
ceutical preparation  of  magnesium  phospho- 
tartrate. 

ABIES.  The  generic  name  of  the  Silver  Firs. 
A.  alba  (Mill.)  [A.  peeiiwUa  (DC.)]  furnishes 
timber  very  similar  to  the  white  deied  of  Pieea 
exeehOf  the  common  spruce.  It  is  the  source 
of  *  Stnsbuiv  turpentine,'  containing  free  abienie, 
dbiehrie,  ana  a-  and  finilnetinolie  adds,  and  an 
amorphous  substance  abidortsent  an  ethereal  oil 
of  agreeable  aromatic  odour,  a  bitter  principle 
and  colouring  matter  (Tsohiroh  und  Weigel,  Arch. 
Pharm.  1900,  238,  411). 

A,  CanadeMis  is  the  source  of  Canada  balsam, 
which  contains  eanadic,  eanadolie,  and  a-  and  iS- 
eanadindlie  aoida,  an  ethereal  oil,  canadoresen ; 
and  small  quantities  of  succinic  add  and  a  bitter 
substance.  The  adds  contain  no  methoxyl 
groups  and  give  the  cholesterol  reactions,  in- 
dudmg  that  of  Tsohugaeff  ({.e.  1000,  238,  487). 

ABIETBMB.  A  hydrocarbon  obtained  by 
distilling  the  terebinthinate  exudation  of  Pintu 
sabiniana  (Doug.),  a  coniferous  tree  indigenous  to 
Calif  omia,  and  growing  on  the  dry  slopes  of  the 
foothJIlB  of  the  Sierra  Nevada  and  on  the  hills 
idong  the  coast,  and  known  locally  as  the  Nut  pine 
or  INgger  pine.  To  procure  the  exudation,  the 
tree  dimng  winter  is  notched  and  guttered  at  a 
convenient  height  from  the  eround,  and  the 
resin  on  distilution  yields  the  liquid  hydro- 
carbon. The  crude  oil  was  met  with  in  San 
Francisco  as  an  article  of  commerce  under  the 

Vou  L—r. 


names  of  'Abietene,'  'Erasine,'  'Aurantine»* 
and  'Thioline,*  and  was  used  for  removing 
ffrease-spots,  paint-stains,  Ac,  from  clothing. 
It  is  a  nearly  colourless  mobile  liquid  of  powerful 
aromatic  smell,  recalling  that  of  oil  of  oranges. 

Abietene  has  been  shown  by  Thorpe  to  consist 
almost  entirely  of  normal  heptane^  C7H,,,  mixed 
with  a  small  quantity  of  a  resin  to  which  its 
characteristio  smell  ox  orange  oil  is  due  (Thorpe, 
Chem.  Soo.  Trans.  35,  296 ;  Sohorlemmer  and 
Thorpe,  Phil.  TTans.  174,  269 ;  v.  alio  Blasdale, 
J.  Amer.  Chem.  Soo.  1901,  162). 

Schoxger  (J.  Ind.  Eng.  Chem.  1913,  6,  971) 
has  shown  that  the  volaUle  oil  of  Pinus  j^tyi 
consists  of  about  96  p.o.  of  n-heptane  and  6  p.o. 
of  an  aldehyde,  apparently  citronellal. 

Abietene  is  also  the  name  given  to  the  hydro- 
carbon which  is  obtained  as  an  oil  by  the  reduc- 
tion  of  abietic  acid  (q.v,)  (Easterfleld  and  Bagley, 
Chem.  Soo.  Trans.  1904,  1238 ;  Kraemer  and 
Spilker,  Ber.  1899,  2953,  3614).  Its  formula  is 
CitHtt,  and  it  ii  probably  deoahydroretene,  as, 
when  carefully  purified,  and  reduced  with 
phosphorus  and  nydriodio  add,  it  yields  a 
nuoreioent  hydrocarbon  identical  with  the  do- 
decahydroretene  of  Liebermann  and  Spiegel 
(Ber.  1889,  780). 

ABIETIC  AGED.  An  acid  obtained  by  digesUng 
colophony  with  dilute  alcohol  and  recrystaUising 
the  product  from  methyl  alcohol  (Maly,  Annalen, 
129, 54 ;  132, 249) ;  or  by  saturating  an  alcoholic 
solution  of  colophony  with  h^dr<^en  chloride 
and  subsequently  recrystallismg  the  product 
(Fluckiger,  J.  1867,  727  ,*  e/.  Cohn,  Chem.  Zeit. 
1916,  &,  791).  It  can  also  be  obtained  by 
distilling  colophony  under  reduced  pressure 
or  with  superheated  steam  (Easterfield  and 
Baglev,  Chem.  Soc.  Trans.  1904, 1238).  Natural 
colopnony  is,  in  fact,  a  vitreous  modifica- 
tion of  abietic  add.  It  oooun  in  resin  spirit, 
from  which  it  may  be  obtained  by  extraction 
with  ether,  shaking  with  sodium  carbonate 
solution  and  then  acidifying.  It  is  obtained 
in  a  purer  condition  bv  recrystaUising  from 
acetic  add,  forms  colourless  tnanguiar  plates; 
m.p.  166^-167°  (Tschireb  and  Wollf,  Arch. 
Pharm.  1907,  1;  153''-154<'  (Mach,  Monatsh. 
1893,    186;     160''-152''    (EUingson,   J.    Amer. 

B 


ABTETrC  ACID. 


Chem.  Soc.  1914,  36,  325).  The  melting-point 
appears  to  be  influenced  by  the  manner  of  heat- 
ing.     Ocean    also    in    Storax.     [a]    —67-8®. 

Aocording  to  Easterfield  and  Bagley  and  Mach, 
it  is  a  derivative  of  phenanthrene,  and  has  the 
formnla  Gi^H^sO,,  whilst  Levy  (Ber.  1906, 3043), 
Koritschoner  (J.  Soc.  Chem.  Ind.  1907,  641), 
Fahrion  (J.  Soc.  Chem.  Ind.  1907,  264),  and 
Vesterbeig  (Ber.  1907,  120)  represent  its  com- 
position as  C,4H,oO|.  Aocoroing  to  Strecker 
(Annalen,  160,  131),  Duvemoy  (Annalen,  148, 
143),  and  Easterfield  and  Bagley  (^.c),  abietic 
acid  is  identical  with  sylvlo  acid ;  it  is  not 
identical  with  pimaric  acid,  which  yields  abietic 
acid  on  distiUation  under  reduced  pressure. 
By  distilling  abietic  acid  under  ordinaiy 
pressure,  or,  better,  by  treatment  with  hydriodio 
acid,  carbon  dioxide  is  evolved,  the  hydrocarbon 
abietene  CigH|A  being  formed  (£.  and  B.  /.c  ; 
Levy,  l.c. ;  Kraemer  and  Spilker,  Ber.  1899, 
3614).  Oxidation  with  nitric  acid  yields  dinitro- 
propane  and  /ran^-cyclo-hexane  1 : 2-dicarboxylic 
acia.  Distillation  with  sulphur  converts  abietic 
acid  into  retene,  CigHig  (E.  and  B.,  Ix, ;  Vester- 
berg,  Ber.  1903,  4200).  Oxidation  with  potas- 
sium permanganate  yields  an  acid  OieUieOs, 
m.p.  123*'  (BCaoh,  Monatsh.  1894,  627) ;  and  a 
method  has  been:  devised  by  Endemann  (D.  B.  P. 
183328 ;  Chem.  Zentr.  1907, 1.  1607)  to  oxidise 
resinous  materials,  containing  abietic  acid,  to 
resin  acids  and  malonic  acid. 

Abietic  acid  is  related  to  retene  and  pinene, 
contains  a  cydfa-hexane  ring  and  an  MO-propyl 
group,  and  has  its  carboxyl  group  attached  to  a 
tertiary  carbon  atom  (Levy,  Zeitsoh.  anorg. 
Chem.  1913,  81,  146). 

Sodium  and  poUusium  abietates  are  prepared 
by  direct  neutralisation;  the  silver  ('vmite), 
copper  (pale  blue),  calcium,  barium,  strontium, 
cobalt  (Ubvender),  nickel  (^greenish-yellow),  iron 
(light  brown),  tine,  chromtum  (greenish-yellow), 
aluminium,  manganese  (pale  pinl)»  and  cadmium 
salts  are  obtained  by  precipitation  of  solutions 
of  salts  of  the  respective  metals  by  a  solution 
of  the  alkaline  abietate  (EUingson,  f.c). 

It  is  converted  by  the  hydrogenation  method 
of  Willst&tter  and  Hatt  into  hydroabietic  acid 
OigH„0„m.p.l76*»-179**,[a]i^«-16-86%  identical 

with  the  acid  obtained  by  Maly  by  reduction 
with  sodium  amalgam  and  alcohol.  For  the 
optical  isomerism  of  the  abietio  adds,  see 
Schulz,  Chem.  Zeit.  1917,  41,  666. 

Detection  and  Estimation. — ^The  following 
colour  reactions  may  be  used  for  detecting 
abietio  acid:— /I)  3  vols,  of  oono.  hydro- 
chloric acid  ana  1  voL  of  ferric  chloride  sol. 
§ive  a  violet  red  colouration ;  (2)  sulphuric  acid 
issolves  abietic  acid  to  a  red  solution;  (3)  when 
heated  with  dry  chloroform,  acetic  anhydride 
and  sulphuric  acid,  a  purple  red  colour  is  pro- 
duced ohangins  through  violet  and  blue  to  a 
greenish  black  (Mach.  l.c. ).  In  order  to  estimate 
abietic  acid  in  resins,  &c.,  10  grms.  of  the  sub- 
stance are  refluxed  with  20-26  c.0.  of  10  p.c. 
alcohoiio  potash  lor  |  hour  on  a  water-bath ;  the 
resulting  soap  is  decomposed  with  dilute  hydro- 
chloric acid,  and  the  separated  resin  filtered  off, 
washed  with  cold  water  and  dried.  It  is  then 
powdered  and  extracted  with  60  c.c.  of  hot 
petroleum  ether.  From  this  solution  abietic  acid 
18  precipitated  by  ammonia,  filtered  off,  dried  on 
the  water-bath,  and  the  ammonia  expelled  by 


gentle  heating.  The  residue  represents  the 
amountof  crude  abietio  acid  in  the  sample  (Rebe, 
Chem.  Zentr.  1907,  L  997). 

Abietic  acid  (or  colophony)  is  used  in  assisting 
the  growth  of  lactic  or  butyric  ferments,  as  it 
favours  the  production  of  that  which  is  present 
in  the  sieater  quantity  and  suppresses  the 
other.  It  promises  to  be  of  great  use  in  the 
fermentation  industry  in  preventing  infection 
(Effront^  Compt.  rend.  136,  1666),  (v.  Colo- 
phony). 

ABISOL.  Trade  name  for  a  40  p.c.  solution 
of  sodium  bisulphite.  Used  as  a  disinfectant 
and  preservative. 

ABBASIVES.  The  various  hard  substances, 
chiefly  of  mineral  origin,  used  for  abrasive  pur- 
poses fall  naturally  into  the  following  groups,  in 
which  the  hardness  is  roughly  inversely  propor- 
tional to  the  complexity  of  chemical  composition. 

Elements, — Diamond  (g.v.)  is  the  harde^  of 
aD  substances  (hardness  b  10  on  Mohs's  scale). 
Inferior  matoial  of  no  use  for  gems  is  known  as 
bo  art  (or  bort),  and  is  crushed  to  powder  and 
much  used  by  lapidaries.  Diamond  powder  is 
the  only  material  with  which  diamond  iteeU  can 
be  ground  and  polished.  Embedded  in  the  edge 
of  a  thin  disc  of  soft  iron,  diamond  powder 
is  largely  used  for  cutting  gem-stones  and  thin 
sections  of  rock  specimens,  and  also  for  slicing 
larger  blocks  of  the  harder  ornamental  stones. 
A  black,  compact  variety  of  diamond  known  as 
carbonado  f  carbonate  *  or  '  carbon')  is  em- 
bedded in  the  steel  crowns  of  rock-drills. 

Amonffst  artificial  products,  steel  and  some 
other  hard  metals  are  used  for  abrasive  purposes. 
The  so-called  crushed  steel,  made  by  ouenching 
white-hot  crucible  steel,  is  used  in  the  stone- 
cutting  trade.  Tantalum  is  an  extremely  hard 
metal  and  may  in  future  find  some  apphcation 
depending  on  hardness. 

Carbides. — Carborundum^  {q.v.)  or  silicon 
carbide,  CSi  (B.=9h),  is  prepared  artificially  in 
the  electric  furnace  from  petroleum-coke  and  the 
purest  quartz-sand,  ana  is  produced  in  larae 
quantities  at  Niagara  Falls.  It  is  largely  made 
into  sharpening  stones  and  grinding  wheels; 
and  sold  under  a  variety  of  trade-names,  e,g, 
crystolon,  exolon,  samite,  &c.  In  lapidaries* 
work  it  has  to  a  large  extent  taken  the  place  of 
corundum ;  but  although  harder  than  corundum, 
it  has  the  disadvantaffe  of  beins  more  brittle, 
and  it  soon  rubs  to  flour.  Caroide  of  boron, 
CBe»  and  silicide  of  boron,  SiB,,  are  also  remark- 
able on  account  of  their  intense  hardness  (H. 
Moissan,  Compt.  rend.  1894,  cxviii,  666). 

Oxides, — CTorundum  {q,v,)  Al^Os  ia»  next 
to  diamond,  the  hardest  of  minerals  (H.  ^  9). 
The  impure  variety,  emery  {q,v.),  is  not  tpuifb  so 
hard.  The  crushed  and  graded  material  is  made 
into  corundum  wheels  and  emery  paper,  and  is 
much  used  in  lapidaries'  work.  Artificial 
corundum,  known  by  the  trade-names  of 
'  alundum,*  '  aloxite,'  *  adamite,'  '  borocarbone,' 
kc,  is  now  manufactured  in  considerable 
amounts  at  Niagara  Falls,  by  fusing  bauxite  in 
an  electric  furnace.  *  Corubin '  is  also  an 
artificial  corundum,  formed  as  a  by-product  in 
the  Goldschmidt  thermite  process. 

Quartz  {q.v,)  SiO,  (H.  =  7),  and  its  several 

>  So  named  by  K.  Q.  Achesoo,  In  1893.  from  carbon  and 
oonindam,  becanae  before  it  bad  been  analyaed,  it  was 
tbooght  to  be  a  compound  of  carbon  and  alnmioA. 


ABSINTH. 


varieties  find  eztenfllve  applications.  Millstones 
and  grindstones  are  made  of  quartz-rock, 
quartzite,  burrstone  (or  buhrstone),  grit,  or 
sandstone  {q.v.) ;  while  soythe-stones,  oilstones 
and  whetstones  {q,v.)  consist  of  homstone, 
lydian-stone  and  other  compact  varieties  of 
quartz.  In  the  form  of  sand,  quarta  is  usckI  as  a 
sand-blast,  in  sconring-soap,  for  cutting  and 
grinding  marble,  making  sand-paper,  &o.  Tri- 
poli or  mfosorial  earth  is  a  powdery  varietv  of 
opal  (hydrated  silica),  and  is  used  for  polishmg. 

SHicaUs.—Q^Tnet  (q.v,)  (H.  =  6^-7))  is 
used  for  making  *  emery '  paper  and  cloth ;  and 
felspar  (q.v.)  (H.=6)  is  also  used  to  a  small 
degree.  Silicate  rooks  are  employed  to  a  small 
extent ;  e.g.  pumice  for  polishing,  and  the  mill- 
stone lava  (leudte-nephefine-tephrite)  of  Nieder- 
mendiff  on  the  Rhine,  for  millstones. 

References, — J.  V.  Lewis,  Abrasives  (Mineral 
Industry,  New  York,  1916,  1917,  xxv,  22-33) ; 
F.  J.  Katz,  Abrasive  Materials  (Mineral  Resources 
of  the  United  States,  U.S.  Geol.  Survey,  1916, 
1916,  ii,  6&-80);  H.  Ries,  Economic  Geology 
(New  York,  1916,  284-297,  with  bibliograuhy). 

ABBASTOL  or  Asaprd  -  Etnuoh  Trade 
names  for  the  calcium  salt  of  iS-naphthol- 
sulphonio  acid,  Ga(GioH70SO,)t,3H,0,  used  in 
the  olarifioation  and  preservation  of  wines.  The 
maximum  quantity  needed  for  tlus  purpose  is 
10  erms.  per  hectolitre.  According  to  Noelting 
ana  Dujardin-Beaumetz  and  Stackler,  the  sub- 
stance is  harmless  from  a  hygienic  point  of  view 
(see  Mon.  ScL  1894,  8,  257 ;  J.  Soc.  Ch^m.  Ind. 
1894,  177,  534).  To  detect  its  presence, 
SanffM-Ferri^  proceeds  as  follows  (Compt. 
rend.  1893,  117,  796) :  200  o.o.  of  the  wine  i» 
boiled  for  an  hour  in  a  reflux  apparatus  wHih 
8  0.0.  of  hydrochloric  acid,  when  the  abrastol 
is  hydrolysed  to  /9-naphthol,  which  may  be 
extracted  with  benzene,  and  the  residue  left 
after  distilling  the  benzene  soL  taken  up  with 
chloroform.  A  fragment  of  potash  is  dropped 
into  the  chloroform  solution,  which  is  Loued 
for  2  mins.,  when  a  blue  colouration  ii  pro- 
duced changing  to  green  and  finally  beoomiiw 
yellow.  0*1  grm.  per  litre  may  thus  be  detected. 
The  presence  of  abrastol  in  no  wav  vitiates  the 
determination  of  potassium  sulphate  (J.  Soc. 
Chem.  Ind.  1894, 177).  Sinibaldi  (Mou.  SoL  7, 
S42)  has  given  the  following  method :  25  c.c.  of 
the  wine  are  neutralised  by  ammonia  and  shaken 
with  25  CO.  of  amyl  alcohoL  After  separation, 
the  amyl  alcohol  is  boiled  to  expel  ammonia,  and 
when  oold  is  shaken  with  0-25  o.c.  ferric  chloride 
soL  A  grey-blue  colouration  denotes  abrastoL 
Gabutti  (ChenL  Zentr.  1904,  2,  370)  proceeds 
in  a  simflar  way,  but  instead  of  ferric  chloride, 
employs  phosphorio  acid  and  formaldehyde 
solution,  when,  in  presence  of  abrastol,  a 
green  fluorescence  is  produced.  (For  other 
methods,  v.  Sanna  Pintus,  J.  Soc.  Ghem.  Ind. 
1900,  933;  Briand,  Gompt.  rend.  1894,  118, 
925 ;  Garietti,  Ghem.  Zentr.  1909,  2,  72.  For 
colour  reactions, «.  Barral,  J.  Pharm.  Ghim.  1903, 
18,  [S]  206;  Sak>mone,  Ghem.  Zentr.  1907,  i.  306.) 

(For  a  review  of  the  various  methods  of  detec- 
tion, V.  Vitali,  Apoth.  Zeit.  1908,  23,  507 ;  J.  Soc. 
Ghem.  Ind.  1908,  830.) 

ABRAUM  SALTS.  {Qeie.  Ahraunualze  :  '  salts 
to  be  removed.')  The  mixed  salts  found  over- 
laying  the   rook-salt  deposit   at   Stassfurt»   in 


Prussia.  These  consist  mainly  of  rock  salt ; 
Camalltte,  a  double  chloride  of  potassium  and 
magnesium  ;  ^y2vin«,  or  potassium  chloride  ;  and 
Kieseriie,  or  magnesium  sulphate,  v.  Potasshtm. 

ABRIN.  A  brownish  vellow  soluble  substance 
obtained  from  the  seeds  of  Ahrtu  preetUoriua 
(Indian  liquorice  or  Jequirity).  Gontains  a 
poisonous  proteid,  resembling,  if  not  identical 
with,  rioin.  Lethal  dose,  according  to  Robert,  is 
only  000001  grm.  per  kilo  body-weight  i  1.6.  1 
to  100,000,000. 

ABROTINE  GtiH,,ONa  is  a  crystalline 
diacid  fluorescent  alkaloid  from  Artemisia 
abroianum,  somewhat  resembling  quinine  (Gia- 
cosa,  Jahresber.  1883,  1356). 

ABSINTH.  (Absinthe,  Fr. ;  Wermuthex- 
tract.  Get.)  One  of  Ihe  best-known  liqueurs  or 
cordials  (q.v.),  is  made  chiefly  at  Lyons,  Mont- 
pellier  snd  Pontarlier  in  France,  and  in  fonner 
years  (vide  infrn)  at  Neufob&tcl  in  Switzerland. 
It  is  a  highly  intoxicating  spirituous  liquor 
flavoured  with  oil  of  wormwood  (Artemisia 
absirUhium,  nat.  ord.  Compasita)  and  other 
essential  oils  as  angelica,  anise,  cinnamon, 
cloves,  fennel,  hyssop,  peppermint,  &o.  (t7.  Oils, 
Essential). 

There  are  three  distinct  processes  in  the 
manufacture  of  absinth,  viz. :  maceration,  dis- 
tillation, and  colouration.  The  leaves  and  flower- 
tops  of  Artemisia  absinthium,  together  with  the 
other  flavouring  ingredients  (which  vary  in  kind 
and  quality  according  to  the  requirements  of  the 
different  manufacturers)  are  digested  with  spirit 
for  periods  varying  from  12  hours  to  10  days, 
according  to  the  temperature  of  the  infusion  and 
the  strength  of  the  spirit  used.  The  French 
manufacturers,  as  a  rule,  digest  for  short  periods 
at  the  temperature  of  an  ordinary  water  bath, 
and  with  spirit  containing  about  85*  alcohol, 
whilst  the  owiss  maceration  process  was  con- 
ducted at  air  temperature  with  spirit  somewhat 
below  British  *  proof '  strength,  or  about  50* 
alcohol. 

The  infusion  is  distilled  and  the  distillate  trans- 
ferred to  the  colouring  vessel  containing  small 
absinth  leaves,  balm  and  hyssop,  dried  and  finely 
divided.  This  vessel  is  hermetically  sealed  and 
is  eently  heated  by  steam  to  a  temperature  of 
60^  in  order  to  extract  ohlorophylL  After 
cooling,  the  green  liquor  is  drawn  off,  and 
strained,  if  necessary,  through  a  hair  sieve.  The 
colouring  is  sometimes  separately  prepued  and 
added  as  required  to  the  colourless  distillate. 
Occasionally  the  latter  is  sweetened  by  the  addi- 
tion of  about  5  p.0.  by  weight  of  crushed 
white  sugar.  Ghlorophyll  for  imparting  the 
men  colour  to  absinth  (and  other  liqueurs)  ia 
frequently  obtained  from  nettles,  pareley,  and 
spinach,  and  is  free  from  objection  provided  the 
vegetable  matter  is  sound. 

On  keeping,  genuine  absinth  assumes  the 
yellowish  tmt  appreciated  by  connoisseurs,  and 
its  qualities  generally  are  improved  by  ageu 
Many  objectionable  varieties  of  absinth  are, 
however,  on  the  market,  made  from  inferior 
spirit,  to  which  essences  and  resins  are  added,  the 
former  to  give  a  fictitious  flavour  and  the  latter 
to  produce  the  opalescence  which  occurs  ^  in 
genuine  absinth  on  the  addition  of  water,  owing 
to  the  liberation  of  the  essential  oils,  resinous 
bodies,  and  colouring  matters  derived  from  the 
plants  and  seeds  used  in  its  manufacture.     Other 


ABSmTH. 


colouring  matteoi  than  ohlorophyll  are  also 
employ ed,  as  indigo,  sulphate  of  copper,  picric 
aoid  and  turmerio  or  other  vegetable  colour. 
Gum  benzoin,  goiaoam  and  rosin  are  also  used 
to  produce  '  milkiness '  on  dilution,  and  even 
chloride  of  antimony  is  said  to  have  been  em- 
ployed for  this  purpose. 

To  detect  adulteration  it  is  usually  suffi- 
cient to  determine  the  essential  oils,  resins, 
and  colouring  matters  {vide  Hubert,  Ann. 
Chim.  anaL  6,  409,  and  Kivi^re  and  Hubert, 
Mon.  ScL  1895,  566).  According  to  Hubert, 
absinth  has  a  specific  gravity  of  0*8966  to 
0*9982,  and  alcoholic  strength  of  47  to  72 
p.0.  by  volume  of  absolute  idcohoL  The 
average  results  of  twelve  samples  expressed  as 

frams  per  litre  were  as  follows :  essential  oils, 
•5  to  5*0;  extractive,  0*36  to  1*72;  acids, 
0024  to  0*288;  aldehydes,  0005  to  0*155;  fur- 
f urol, 0*0002 to 0-007 ; ethers, 0005 to 0-123.  The 
strength  of  absinth  as  imported  into  the  United 
kingdom  varied  from '  proof '  to  about  20  oV%r 
proof,  and  rather  more  than  3000  eallons  were  im- 
ported annually  before  the  war.  The  amount  rose 
to  4000  gallons  in  1915,  since  when  its  importation 
into  the  United  Kingdom  has  been  prohibited. 

Although  genuine  absinth,  taken  in  modera- 
tion, has  valuable  qualities  as  a  cordial,  sto- 
machic, and  febrifuge,  its  characteristic  bitter 
principle,  absinthiin  (g.v.),  is  an  active  poison, 
having  a  very  injurious  effect  upon  the  nervous 
system  of  those  addicted  to  the  habitual  and 
immoderate  consumption  of  absinth.  Legal 
measures  have  thereiore  been  taken  in  various 
European  countries  to  control,  restrict,  or  even 
prohioit  its  sale.  In  France,  liqueurs  may  not 
contain  more  than  1  gram  per  litre  of  oil  of 
wormwood  or  other  oil  of  similar  toxic  nature, 
whilst  in  Belgium  and  Swizerland  the  manufac- 
ture and  aeSd  of  absinth  have  been  entirely 
prohibited.  J.  C. 

AB8INTHIN  or  AB8INTHII1I  C^fi^^O..  The 
bitter  principle  extracted  from  the  dried  leaves 
of  large  absinth  or  wormwood  {Artemisia 
absinthtum)  is  an  active  poison »  and  it  is  to 
its  presence  in  oil  of  wormwood  that  the  toxic 
effect  of  absinth  (g.v.)  appears  to  be  due. 

Various  formiuA  have  been  assigned  to  this 
substance,  the  differences  being  due  to  the 
difficulty  of  obtaining  it  in  a  pure  state  (Mein, 
Annalen,  8, 61 ;  Luck,  Annalen,  78, 87 ;  Kromayer, 
Arch.Pharm.  [2]  108,  129). 

Pure  crystallised  absinthiin  was  first  isolated 
by  Duquesnel  (Bui.  de  Therapeutique,  107,  438). 
Senger  obtamed  absinthiin  as  a  pale  yellow 
amorphous  substance  melting  at  65*  and  naving 
the  empirical  formula  Cifi^fi^.  This  formula 
was  confirmed  later  by  Bourcet,  who  found  that 
the  pure  substance  crystallises  in  fine  white 
prismatic  needles  melting  at  68',  the  amorphous 
lorm  and  lower  melting-point  found  by  Senger 
being  probably  due  to  traces  of  a  resinous 
impurity. 

According  to  Senger  and  Bourcet,  absinthiin 
is  a  glucoside,  free  from  nitrogen,  and  is  decom- 
posed by  the  action  of  dilute  acids,  or  even  bv 
boiling  with  water,  into  dextrose,  a  volatile  oil, 
ftnd  a  solid  resinous  bodv  of  the  aiomatio  series. 
It  is  soluble  in  alcohol,  ether,  chloroform,  or 
benzene;  difficultly  soluble  in  light  petroleum, 
water,  though  more  soluble  in  cold  than  in 
boiling  water.     It  gives  a  precipitete  with  tannic 


aeid  and  with  sold  chloride,  which  is  reduced  on 
warming ;  yields  volatile  fatty  acids  on  oxidation 
with  nitric  acid,  and  oxalic  and  picric  acids  with 
potassium  chromate  and  sulphuric  acid.  With 
Fidhde's  reagent  it  gives  a  brown  colour,  ohan|r. 
ing  to  vk>let,  then  mue ;  and  with  sulphuric  aoid 
brown,  passing  through  green  to  blue  (SenjEer, 
Arch.  Pharm.  230,  103 ;  and  Bourcet,  Bull  Soo. 
ohun.  [31  19,  537).  J.  C 

ABSUTHOL  Ci,Hi.O.    The  essential  prin- 
iple  of  oil  of  wormwooa  derived  from  Ariemisia 


cipi 


abnyiihium  (nat.  ord.  CompoBUa)^  a  plant 
indigenous  to  most  European  countries  and  com- 
paratively recently  mtzoduced  mto  the  United 
States  of  America,  whence  increasing  supplies  of 
the  cheaper  qualities  of  wormwood  oil  are  now 
obtained. 

Although  the  oil  obtained  by  the  disUllatbn 
of  wormwood  has  been  known  for  at  least  four 
centuries,  ite  dhemical  composition  was  first 
systematically  Investigated  in  1845,  when  Leblanc 
(Compt.  rencL  21,  379)  showed  that  ite  principal 
constituent,  boiling  at  203°,  has  the  formula 
C  iqHi  eO.  This  was  confirmed  later  by  Gladstone 
and  other  investigators  (Chem.  Soc.  Trans.  17, 1), 
and  by  Beilstein  and  Kupffer  (Annalen,  170, 290), 
who  ^ave  to  the  product  the  name  *  dbsiiUhtiL^^ 
and  identified  ite  dehydration  product  with 
cymene. 

Methods  for  the  identification  of  absinthol 
have  been  described  by  Guniasse  (J.  Pharm. 
Chim.  1907,  25  (180-2))  and  Enz  (Ohem.  Zentr. 
1911,  ii.  576),  but  these  can  hardly  be  accepted 
as  conclusive  of  the  presence  of  wormwood, 
since  thujone  occurs  in  other  plante.  A  negative 
reaction,  however,  proves  the  absence  of  worm- 
wood. 

'  Semmler  (Ber.  25,  3350)  proved  absinthol  to 
be  a  ketone  identical  with  thujone  or  tanaoetone, 
which  occurs  laigely  in  other  essential  oils,  as  oil 
of  tansy,  sace,  and  Aikmina  bareiieri.  It  is  a 
colourless  oiJy  liquid  of  pleasant  odour,  strongly 
dextroiototory  (about  +68''),  boils  at  203^ 
density  0-9126  at  20'',  and  refractive  index 
1*4495. 

Though  isomeric  with  camphor,  it  differs  from 
that  body  in  combining  with  sodium  bisulphite 
and  in  not  being  converted  into  camphoric  add 
by  means  of  nitric  acid,  nor  into  campho- 
oarboxylic  add  by  treatment  with  carbon 
dioxide  and  sodium.  With  melted  potash  it 
fldves  a  resin,  but  no  add.  When  heated  with 
PaSf  and  ZnCl,  it  yidds  cymene  (Beilstein  and 
Kupffer,  Ber.  6,  1183;  Annalen,  170,  290; 
Wnght,  Chem.  Soc.  Trans.  27,  1  and  319; 
Semmler,  Ber.  25,  3343  and  27,  895).       J.  C. 

ABUTILON  INDICUM  (Sweet),  PETAREE 
or  TUBOCUTY.  The  bark  of  this  malvaceous 
tree  consiste  of  long,  thin,  tough  fibrous  strips 
(bast  fibres),  and,  according  to  Svmock  (Phann. 
J.  [3]  8,  383)  and  others,  is  worthy  of  attention 
as  a  source  of  fibre. 

ABYSSINIAN  GOLD.  A  yellow  aUoy  of  90*7 
parte  of  copper  and  8*3  of  dnc  The  ingot  is 
plated  on  one  side  with  gold,  and  is  then  rolled 
out  into  sheete,  from  which  artides  of  jewelleiy 
are  formed  in  the  usual  way,  the  amount  of 
gold  on  the  finished  article  varying  from  0*03  to 
1  *03  p.c.  Known  also  as  Tahni  g3d.  The  term 
is  sometimes  applied  in  trade  to  Aluminium 
Bronze. 

ACACIA  BARK.    Aeadm  Cortei:^  B.  P.    The 


AGETALS. 


dried  bark  of  Acacia  arabica  (Willd)  and  of  A. 
decurrens  (WiUd). 

ACACIA  CATECHU  (WiUd)  or  KHAIR  is  a 
tree  growing  in  variooB  parts  of  India.  Its  un- 
ripe pods  and  wood,  oy  deoootion,  yield  a 
cateono  (Agricolt.  Ledger,  1895,  No.  1,  and 
1896,  No.  35),  known  by  the  name  of  Cutoh  or 
Kutoh,  which  must  not  be  oonfoonded  with  the 
officinal  oatechu  {Catechu  wUidum).  It  is  used 
in  the  preparation  of  some  leathers  and  by  dyers. 
The  timl)er  is  also  used  for  construoti(mal  and 
other  purposes. 

ACACIA  GUM  V.  Qums. 

AC AHTHTTE.  A  form  of  silver  sulphide  found 
at  tiie  Enterprise  mine,  near  Rico,  in  black 
crystals  of  ortnorhombio  halnt  (Chester,  Zeitsoh. 
Kryst.  Min.  1896,  26,  526). 

ACAROm  RESm  or  BOTANY  BAY  RESIN 
9.  Xanthorrhcea  Bdhanu,  art.  Balsams. 

ACCIPENSERINE*  A  protamine  belonsing  to 
the  sturine  group  found  in  the  testis  of  Acci- 
penaer  steUattu.  Composition  of  the  sulphate : 
C,,H,,0^u,4HaS0«  (Kura^^ff,  Zeitoch.  physiol. 
Chem.  1901,  32,  197). 

ACENAPHTHENEQUINONE.  iSfeeQuiNONES. 

ACEBDOL.  Trade-name  for  calcium  per- 
manganate. 

ACETAL  (diethyl  acetal ;  ethylidene  diethyl 
ether;  ethanediol  (1 : 1)  diethyl  ether)  CcHi^Oi, 
or  CH,CH(0C,H5),.     See  Acbtals. 

ACEtTALS.  Acetals  are  the  ethers  and  esters 
derived  from  the  so-called  (^emtnoZ-glycols,  which 
are  themselTes  for  the  most  part  incapable  of 
existence;  such  glycob  possess  the  general 
formulae— 

R.^    .OH 

B,/  \)H 

(where  Ri  and  R,  may  be  either  hydrogen  or 
aliphatic  or  aromatic  radicals) ;  they  split  up  at 
onoe  into  water  and  the  corresponding  anhydrous 
compound,  which  may  be  an  aldehyde  or  a 
ketone ;  thus,  in  the  case  of  ordinary  acetalde- 
hyde,  we  have  the  relationi^ps : 

CH,CH(OCOCH,),  CH,CH(00,H6), 

Etl^lidene  dlaoetate.  Acetal. 

±(CH,CO)jO  iCjHjOH 

%H,CHO^ 

Acetaidehyde. 

[CH,CH(OH),] 
Ethylidene  glycol. 

Acetals  may  thus  be  given  the  general  formula : 

R,^^OR. 

(where  Ri  and  R,  are  any  alkyl  or  aryl  radicals, 
and  Rt  and  R4  any  acidyl,  alkyl  or  aralkyl 
radicals). 

We  may  distinguish  two  types  of  acetals, 
according  to  whetner  the  products  are  alkyl 
ethen  or  add  esters ;  the  term  *act.tal '  is  more 
usually  applied  to  the  former  class. 

(a)  Didlkyi  Ethers  of  gem.'Qlycols  (Acetals  of 
Aldehydes  and  Ketones). 

They  are  produced  by  heating  alcohol  and 
an  aldehyde  alone,  but  the  yield  ib  very  poor 
(Genther,  Annalen,  126,  62).  A  better  yield 
is  obtained  by  adding  a  sinail  quantity  of  a 


catalyst  such  as  ferric  chloride,  or  a  trace  of 
acid  to  the  mixture  (Trillat  and  Cambier,  Compt. 
rend.  118,  1277).  Still  better  is  the  method  of 
Fischer  and  Glebe  (Ber.  30,  3053;  31,  545), 
consisting  in  passing  1  p.o.  of  hydrochloric 
acid  into  the  mixture  and  neating,  or  allowing 
to  stand  for  some  time ;  after  washing  with  a 
little  dilute  potassium  carbonate  solution  tie 
product  is  dried  over  anhydrous  potassium 
carbonate  and  fractionated,  the  yield,  however, 
is  only  about  50  p.c.  in  the  case  of  diethyl  acetal, 
as  the  reaction  is  reversible  : 

R-CH0+2C,H,0H  ^    RCH(OC,H.),+H,0 

Acetals  may  also  be  made  by  passing  pure 
phosphine  through  the  cooled  mixture  of 
aldehyde  and  akohol  (Girard,  Compt.  rend. 
91,  629). 

The  most  convenient  method  for  the  pre- 
paration of  acetals  is,  perhaps,  that  described 
by  King  and  Mason  (Eng.  Pat.  101428),  consist- 
ing in  treating  a  mixture  of  an  aldehyde  and  an 
alcohol  with  certain  metallic  salts — or  their 
saturated  aqueous  solutions — such  as  the 
chlorides  or  nitrates  of  aluminium,  calcium, 
cerium,  magnesium,  manganese,  &o.,  thus  50 
grams  acetaidehyde  and  120  grams  95  p.c. 
alcohol  are  mixed  and  then  20  grams  anhydrous 
calcium  chloride  are  added.  The  mixture 
becomes  warm,  and  is  allowed  to  stand  for  some 
time,  with  occasional  shaking.  It  has  then 
separated  into  two  layers,  the  upper  of  which  is 
removed,  washed  with  water,  then  with  sodium 
carbonate  solution,  dried  over  calcium  chloride, 
and  finally  over  anhydrous  potassium  carbonate. 
It  is  then  fractionated,  and  yields  120  grams 
acetal,  or  90  p.o.  of  theory.  The  addition  of  a 
small  quantity  of  an  acid  has  the  effect  of 
causing  the  reaction  to  take  place  more  quickly. 

It  IS  also  possible  to  prepare  certain  acetal-3 
by  heating  another  acetal  with  the  desired 
alcohol : 

RCH(0R,),+2R,-0H 

T=i  R-CH(0R,),+2Ri-0H 

Thus  on  heating  ordinary  diethyl  acetal  with 
excess  of  methyl  alcohol  it  is  converted  almost 
completely  into  dimethyl  acetal  (Delepine, 
Compt.  rend.  132,  968;  Bull.  Soc.  chim.  [3], 
26,  074).  The  converse,  however,  does  not  hold 
good,  since,  on  heating  dimethyl  acetal  with 
excess  of  ethyl  alcohol  practically  no  reaction 
occurs  (Geuther  and  Bachmann,  Annalen,  218, 
44).  In  general,  the  series  of  acetals  can  be 
descended  by  heating  any  member  of  the  group 
with  an  alcohol  containing  a  smaller  number  of 
carbon  atoms  than  is  present  in  its  alcohol 
residue.  If  a  little  hydrochloric  acid  be  added 
a  balanced  reaction  takes  place,  and  a  certain 
proportion  of  all  the  possible  products  is  ob- 
tained, the  products  of  higher  molecular  weight 
predominating  (Del6pine,  Compt.  rend.  132, 
331,  968).  Another  seneral  method  of  wide 
applicability  is  that  of  Claisen  (Ber.  29,  1007  ; 
31,  1010 ;  40,  3903),  consisting  in  treating  the 
aldehyde  or  ketone  with  orthoformic  ester  in 
alcoholic  solution  in  presence  of  a  suitable 
catalyst,  such  as  mineral  acids,  oxalic  acid, 
ferric  chloride,  ammonium  chloride,  sulphate  or 
nitrate,  &c.  (c/.  also  Arbusow,  Ber.  40,  3301 ; 
Claisen,  ibid.  40,  3912).  Orthoformic  esters  can 
also  react  with  alkyl  magnesium  salts  to  yield 


ACETAL8. 


Aoetals  (Bodrouz,  Oompt.  rand.  138,  700; 
TschitBchibahin,  Ber.  37,  186),  or  with  haloce- 
imted  fatty  esters  in  proflenoe  of  zinc  (Tsohitscni- 
babin,  J.  prak.  Ghem.  [2]  72,  326 ;  Glaisen,  Ber. 
31,  1010) : 

(0,H40),-0H0C,H.+Br-CH(CH,)-C00R+Zn 
=(C,H,0),CHCH(CHJ-COOR+C^,OZnBr 

(C,H,0),CH-CH(CH,)-COOR 
-^  {C,HjO),CH-CH(CHJ-COOH 

•^  (C,HjO),CHCH,CH, 

Certain  spedal  methods  for  production  of  aoete^ 
are  availablo  for  formylal  and  diethyl  acetal, 
and  will  be  noted  later. 

Oeneral  Properties. — ^The  true  acetals,  or 
dialkyl  ethers  of  gem-glycols,  are  colourless 
liquids  of  pleasant  ethereal  odour,  which  can  be 
dutilled  without  decomposition.  The  lower 
members  are  somewhat  soluble  in  water,  by 
which  they  are  slowly  hydrolysed ;  in  presence 
of  dilute  adds  the  hydrolysis  is  almost  instan- 
taneous; thev  are  stable  to  alkalis  even  on 
boiling.  With  various  metallic  salts  such  as 
magnesium  or  zinc  iodides,  calcium  chloride  or 
magnesium  bromide,  double  compounds  are 
formed,  e.g.  :»feBr,+2CH,(C0CHa)„  m.p.  112° ; 
MgI,+20H,<3B[(OC,H5)„  m.p.  86*  (Timmer- 
mans,  Ohem.  Zentr.  1007, 1,  1007).  The  acetals 
form  hydrates  in  certain  cases;  thus,  diethyl 
formvlal  forms  a  hydrate  0Ha(OO,Hs)2-H,O, 
which  is  a  liquid  of  b.p.  74*-76*,  with  an  odour 
of  rum,  and  dissolves  in  16  parts  water  at 
20°  0. ;  the  higher  homologues  also  form  mono- 
hydrates,  boibng  at  lower  temperatures  than 
the  acetals  themselves  (TriUat  and  Cambier, 
Oompt.  rend.  118,  1278). 

Tne  acetals  are  of  considerable  use  in  place 
of  the  free  aldehydes  or  ketones  for  synthetic 
pmnposes,  on  the  one  hand,  owing  to  their 
higher  boiling-points  {e.g.  acetaldehyde,  b.p.  20° ; 
diethyl  aoetu,  b.p.  103°),  and  also  to  the  fact 
that  alcohol  and  not  water  is  split  off  in  the 
condensation,  which  has  a  marked  effect  on  the 
yield.  Thus  in  preparing  vinyldiaootoneamine 
b^  condensing  acetaldehyde  or  paraldehyde  witli 
diacetoneamine  add  olalate  (Fischer,  Ber. 
17, 1793  ;  Heintz,  Annalen,  178,  326  ;  191, 122  ; 
Harries,  Ber.  29,  522),  only  a  poor  yield  of 
product  is  obtained  even  on  prolonged  heating  ; 
out  if  acetal  be  substituted  tne  reaction  is  com- 
plete in  a  few  hours  with  almost  quantitative 
yield  (e/.  King,  Mason  and  Sohryver,  Eng.  Pat. 
101738)  owing  probably  to  the  absence  of  the 
inhibiting  effect  of  water. 

In  addition,  the  acetals  can  be  readily 
halogenated  and  converted  into  amino-,  hydroxy-, 
alkoxy-,  Ac,  derivatives,  which  react  like  the 
corresponding  aldehydes. 

They  can  be  separated  from  their  aqueous 
solutions  by  the  addition  of  concentrated 
calcium  chloride  solution.  They  are  misdble 
with  alcohol  and  ether ;  their  vapours  or  solu- 
tions in  alcohol,  benzene,  or  acetone  slowly 
harden  dry  gelatine  films  (Beckmann  and 
Soharfenbeiger,  Chem.  Zentr.  1896,  ii.  930). 
When  heatea  in  a  sealed  tube  with  glacial  acetic 
acid  the  corresponding  aldehyde  is  obtained 
(BeilBtein,  Annalen,  112,  239). 

Mixed  acetals  ocmtainhig  two  different 
alcohol  residues  have  been  dracribed  by  Bach- 
maon  (/.c),  but  according  to  Riioenoamp 
(Annalen*  226»  271)  and  Fritz  and  Schumacher 


(Annalen,  279,  306),  these  consist  of  mixtures 
of  two  acetals  in  molecular  proportions^  Del^- 
pine^  however  (Compt.  rend.  132,  331,  968), 
daims  to  have  obtained  mixed  aoetivls. 

Fonnylals  CH,*(OR),. 

Methylal  GH,-(OCH,),  (dimethyl  formylal), 
b.p.  41-3°-41-7°,  sp.  gr.  0*862,  can  be  obtained 
by  treatiag  a  mixture  of  methyl  alcohol  and 
40  p.c.  formaldehyde  solution,  wiui  solid  caldum 
chloride  and  a  little  hydrochloric  add  (Fischer 
and  Giebe,  Ber.  30,  3054).  It  can  also  be 
obtained  by  treating  methylene  chloride  with 
sodium  methylate  (Amhold,  Annalen,  240, 
197),  and  also  bv  treating  chlormethyl  alkyl 
ether  CHJOR)Gi  (obtained  by  condensing 
formaldehyoe  and  alcohol  with  excess  of  hydro- 
chloric acid)  with  sodium  methylate  (Favre, 
Compt.  rend.  119,  284;  Bull.  Soc.  chim.  [3] 
11,  879;  Henry,  Ber.  26,  Ref.  933;  Compt. 
rend.  119, 426 ;  de  Sonay,  Ber.  27,  Ref.  337) ;  or 
bv  heating  polyoxymethylene  and  the  required 
alcohol  with  1  to  4  p.c.  ferric  chloride  for  2-10 
hours  (TriUat  and  Cambier,  Compt.  rend.  118, 
1277).  It  can  be  used  for  various  condensations 
in  place  of  formaldehyde,  and  is  a  good  solvent 
for  many  oiganic  compounds.  {Cf.  also  Kane, 
Annalen,  19,  175 ;  Malaguti,  Annalen,  32,  65 ; 
Renard,  Ann,  chim.  phys.  [6]  17,  290 ;  Briihl, 
Annalen,  203,  12,  26 ;  Fileti  and  de  Gaspari, 
Gazz.  chim.  Ital.  27,  ii.  293 ;  Trillat,  Compt. 
rend.  137,  187;  Del^pine,  Bull.  Soc.  chun. 
[3]  25,  364;  Favre,  Bull.  Soc.  chim.  [3] 
11,  1096;  Bruhl,  Ber.  30,  169;  Berthdot, 
Compt.  lend.  126,  675;  Trillat  and  Cambier, 
Compt.  rend.  118,  1277;  Brochet,  BulL  Soc. 
chim.  [3]  13,  687.) 

The  following  f ormvlals  are  known,  but  the 
higher  members  are  of  little  importance  : — 

Diethyl  methylal  CH,(OC,H,)„  b.p.  87°; 
sp.  gr.  0-834  (20°)  (Amhold,  Ic. ;  Greene,  Chem. 
News,  60,  76 ;  Pratesi,  Ber.  16,  1870 ;  Favre, 
I.e. ;  Trillat  and  Cambier,  Compt.  vend.  118, 
1278). 

Dipropyl  methylal  CR^iOC JS.^)^,  b.p.  136° ; 

9>.  ST.  0*834  (20°)  (Amhold,  f.c. ;    Trillat  and 
iEunoier,  l.c.;   Favre,  Bull.  Soc.  chim.  [3]  11, 
881). 

Di'ieopropyl  methylal  CH,(OC«H;)„  b.p. 
118° ;  sp.  gr.  0*831  (20°)  (Amhold,  I.c. ;  Trillat 
and  Cambier,  {.c). 

Di-iaobvtyl  methylal  CHJOCaH,),,  b.p.  164° ; 
sp.  gr.  0*824  (20°)  (Amhold,  l.c. ;  Gorbow  and 
Elesder,  Ber.  20,  Ref.  778 ;  Trillat  and  Cambier, 

I.C.). 

Di-isoamylmethylal  CH,(OCtHii)t.  b.p.  206° ; 
sp.  AT.  0*835  (20°)  (Amhold,  f.c. ;  TriUat  and 
(Sunoier,  l.c.). 

Dihexyl  methylal  CH,(OC,H„),-f  H,0,  b.p. 
174°-175°;  sp.  gr.  0*822  (15°)  (TriUat  and 
Cambier,  {.c). 

LHoctyl  methylal  CH,(0C»Hi7)„  b.p.  289° ; 
sp.  gr.  0*848  (16°)  (Amhold,  l.c. ;  Trillat  and 
Cambier,  l.c.). 

Cf/clohcaganol  formal  (CaHiiO),-CH,  is  pro- 
duced from  cyclohexanol,  40  p.c.  formaldehyde 
solution  and  hydrochloric  acid  (Murat  and 
Cathala,  J.  Pharm.  Chim.  6, 289). 

Aeetals  CH,CH(OR),. 

Dimethyl  acetal  CH,CH(OCH,)a  occurs  in 
crude  wood-spirit,  b.p.  63° ;  sp.  ar.  0*866  (22°) 
(Dancer,  Aniialen,  132,  240;  Alsbeig,  Jahiesb. 
f.  Chem.  1864,  486 ;   Geuther  and  Bachmann, 


AOETALa 


Annalen,  218»  44 ;  Schiff,  Annalen,  220,  104 ; 
223,  74). 

Diethyl  aeekU  CH,CH(OC«H.).  (usually 
known  simply  as  *Aoetal*)  (=etnylidene  di- 
ethyl ether;  ethane-diol-(l :  l)-dietiiyl  ether) 
(c/.  DSberainer,  Gm.  4.  806 ;  Liebig,  Annalen, 
6,  26;  14,  166;  Stas.  Ann,  Chim.  Phys.  [3] 
19,  146 ;  Wnrtz,  Ann.  Chim.  Phys.  [3]  48,  70 ; 
Geuther,  AntuJan^  126, 63). 

To  prepare  aoetal  by  Wurta's  method,  2  parts 
aloohof  are  added  to  a  mixture  of  3  parts  man- 
ganese dioxide,  3  parts  sulphurio  acid  and  2  parts 
water,  and,  after  the  effervescenoe  first  produoed 
has  subsided,  the  whole  is  heated  at  100*  until 
3  parts  have  distilled  over.    The  product  is 


with  solution  of  calcium  chloride  and  the  ethereal 
layer  which  separates  is  distilled.  The  product 
contains  aldehyde  and  ethyl  acetate  in  fl^ddition 
to  acetal ;  to  remove  these  it  is  shaken  with  con- 
centrated aqueous  potash,  the  brown  liquid 
separated  from  the  aqueous  layer  is  distilled, 
and  the  distillate  shaken  with  c^ium  chloride. 
It  is  then  heated  with  twice  its  volume  of  con- 
centrated aqueous  soda  in  sealed  tubes  at  100* 
for  24  hours,  separated  from  the  soda,  distUled, 
the  distillate  again  rectified :  the  fraction  100*- 
105*,  which  constitutes  the  greater  portion,  is 
aoetaL 

In  addition  to  its  formation  as  a  by-product 
in  the  oxidation  of  alcohol,  acetal  can  also  be 
obtained  from  a  mixture  of  acetaldehyde  (1  voL) 
and  absolute  alcohol  (2  vols.)  (1)  by  heating  with 
acetic  acid  (}  voL)  for  12  hours  at  100*  (Geuther, 
Annalen,  126,  63);  (2)  by  cooling  in  a  freezing 
mixture,  passing  dry  h^diogen  cmoride  to  satu- 
ration, and  decomposmg  me  resulting  mono- 
ohlorether  with  sodium  ethozide  (Wurts  and 
FrapoUi,  Compt.  rend.  67,  418 ;  Annalen,  108, 
223) ;  or  (3)  oy  cooling  a  mixture  of  equal 
volumes  to  —21*,  and  passing  a  current  of  pure 
hydrogen  phosphide  for  24  hours  (Engel  and 
Girard,  Compt.  rend.  92,  692 ;  J.  1880,  694). 

The  most  convenient  method  is  that  of 
King  and  Mason  (E.  P.  101428,  vide  supra). 
On  a  technical  scale  considerable  interest 
attaches  to  the  production  of  diethvl  acetal  from 
acetylene  by  a  modification  of  the  process  of 
KutBcherow  for  preparing  acetaldehyde  from 
acetvlene  and  water  in  the  presence  of  a  mercury 
catalyst  (c/.  Kutscherow,  Ber.  14,  1540;  42, 
2769).  Thus  the  Chemisohe  Fab.  Griesheim 
Elektron  (£.  P.  14246,  1913)  describe  the  pro- 
duction of  ethers  of  ethylidene  glycol  by  the 
action  of  acetvlene  upon  lucohols  in  the  presence 
of  mercury  salts.  They  are  stated  to  be  solvents 
for  cellulose  esters.  Boiteau  (E.  P.  16806, 1914) 
describes  the  production  of  ethylidene  ethers 
by  a  similar  method  ;  and  in  E.  P.  16919,  1914, 
a  further  modification  is  claimed,  consisting 
in  forming  the  catalyst  in  eitu,  e.g.  bv  adding 
mercuric  oxide  or  the  mercury  salt  of  a  weak 
acid  to  the  liquid,  and  then  adding  sulphuric 
acid  to  form  the  sidphate. 

Acetal  is  a  colourless  liquid  with  agreeable 
odour:    b.p.   104'',  and  sp.  gr.  0*821  at  224'' 

I  The  b.p.  is  giveo  as  in  the  original  paper,  but, 
inasmacb  as  b.p.  of  acetal  Is  104".  it  seems  probable 
that  05°  ii  a  misprint  for  some  lilgher  temperature — 
sayl06^ 


(Stas,  Annalen,  64,  322) ;  b.p.  103 -7*- 104*3*  at 
744-4  mm.,  and  sp.  gr.  08314  at  20''/4''  (Bnihl, 
Annalen,  203»  26).  It  is  soluble  in  18  vob.  of 
water  at  26*,  and  the  solubility  increases  as  the 
temperature  rises.  Acetal  is  misoible  in  all 
proportions  with  alcohol  and  ether,  does  not 
reduce  ammoniacal  silver  solution,  and  is  un- 
altered on  exposure  to  air;  platinum  black, 
however,  oxidises  it  first  to  acetaldehyde  and 
subsequently  to  acetic  acid.  For  formation  and 
hydrolysis,  see  Lapworth  and  Fitzgerald  (Proc. 
Chem.  Soo.  24,  163). 

Acetal  has  some  solvent  power  for  cellulose 
esters.  A  use  for  aoetal  is  suggested  by 
Ostromisslensky,  consisting  in  preparing 
erythrene  (butadiene)  from  it  by  passing  over  a 
heated  catalyst,  such  as  alumina  at  360''-460* 
(J.  Russ.  Phys.  Chem.  Soc.  47,  1472,  1609 ;  c/. 
also  Boiteau,  E.  P.  16806,  1914).  Piotet  (Ber. 
46,  2688;  £.  P.  17678,  1914)  describes  the 
production  of  a  synthetic  alkaloid,  which  ho 
terms  coralydine,  by  condensing  tetrahvdro- 
papaverine  and  aoetal  in  16  p.c.  hydrocnloric 
aoid  on  the  water-bath;  the  product  exists 
in  two  isomeric  forms,  a-  and  /3-. 

On  heating  with  phosphorus  pentoxide  the 
elements  of  alcohol  are  removed  from  acetal, 
leaving  vinyl  ethyl  ether ; 

CH,CH(OC,H5),-C,H50H  -  CH,:CHOC,H, 

which  foims  a  liquid,  b.p.  36*6*  ;  sp.  gr.  0'702 
(14*5*),  and  is  split  up  by  dilute  sulphuric  acid 
into  aoetaldehvde  and  alcohol  (Wislicenus, 
Annalen,  192,  106 ;  Henry,  Compt.  rend.  100, 
1007;  Nef.  Annalen,  298,  327;  Claisen,  Ber. 
31,  1021 ;  Tschitschibabin,  J.  prak.  Chem.  [2] 
74, 424).  When  heated  with  acetic  anhydride  to 
160*  one  eth^l  group  is  replaced  by  an  acetyl 
group  yieldmg  *  acetaldenyde-ethyl  acetate,* 
CH,-CH(0CaH5)(0C0CH,),  b.p.  126^-130*; 
sp.  gr.  0'941.  On  boiling  with  water  it  splits 
up  into  acetaldehyde,  ethyl  alcohol,  and  acetic 
acid  (Claisin,  Ber.  31,  1018). 

Acetal  does  not  give  the  iodoform  re  action 
until  shake  n  with  a  few  drops  of  hydrochloric 
acid,  whereby  the  aoetal  is  hydrolyscd  to  alcohol 
and  aldehyde.  Estimation  in  presence  of  paral- 
dehyde, see  Orton  and  McKie,  TianB.  Chem.  Soc. 
109,  184. 

Derivatives. — ^Mdno-,  dl-,  and  trichloracetal 
are  obtained  as  intermediate  products  in  the 
preparation  of  chloral  bypassing  chlorine  through 
80  p.c.  alcohol  (Lieben,  Ann.  Chim.  Phys.  [3] 
62,  313;  Patem6,  Compt.  rend.  67,  766). 
According  to  Krey  (J.  1876,  476),  a  better  yield 
of  these  derivatives  is  obtained  if  a  mixture  of 
2  parts  absolute  alcohol,  3  parts  manganese 
dioxide,  3  parts  sulphuric  acid,  and  2  parts 
water  is  heated  until  ^  of  the  liquid  has  distilled 
over  and  chlorine  is  passed  through  the  well- 
cooled  distillate  uatil  it  shows  signs  of  turbidity. 
In  either  case  tUe  product  is  washed  with 
water,  dried  over  calcium  chloride,  and  sub- 
mitted to  fractional  distillation.  The  fraction 
80°- 120°  contains  chiefly  aldehyde  and  com- 
pound ethers,  120°-170°  chiefly  monochloracetal, 
170°-185°  dichloracetal  (Licben,  i.e.),  and  the 
fraction  boiling  above  185°  contains  trichloracetal 
(Patemb,  I.e.).  These  compounds  may  then 
be  obtained  in  the  pure  stale  by  repeated 
fractionation. 

A  better  method  of  obtaining  monochloracetal 


8 


ACETAL8. 


it  by  pjUMimg  chloriiie  thioiigh  well-oooled  94-09 
p.c.  abohol  nniil  the  chJorinAtod  nrodnet  ha* 
a  tp.  gr.  l-itt-l-fKI  at  26^  Hall  tiie  original 
▼olniiie  <A  alcohol  is  added  and  the  mixture 
heated  a  few  houn  at  Sff-W.  The  iiee  add 
is  remored  by  calcium  carbonate;  the  oil 
washed  with  water,  dried  and  fractionated. 
The  proDortion  of  di-  and  to-  ehloro-deriyatiTes 
formed  depeiidi  on  the  amoont  of  chlorine  added 
(FritMh,  innalen,  279,  288). 

MMoeUaraedal  CH^-CHCOCsH  J,  (lieben, 
Annalen,  146,  193;  Patemd,  Mazsara,  Ber.  6, 
1202 ;  Klien,  J.  1876,  336 ;  Nattecer,  Monateh. 
3,  444  ;  5,  497  ;  Wiflticeniu,  Annalen.  192, 106 ; 
Frank,  Annalen,  206,  341 ;  Fritaoh,  Atin»lA«^ 
279, 300)  is  a  ookmrlesa  liquid,  having  an  aromatic 
etherealodottr;b.p.  156'*;sp.gr.  1  •0418  at  0°,  1*026 
at  W  (Klien) :  166*'>16r  (Antenrieth,  Ber.  24, 
IGO).  When  heated  with  bleaching  powder  it 
jrields  di-  and  triehloraoetal,  chloroform,  and 
chlorinated  acetaUehyde  (Ckddberg,  J.  pr. 
Chem.  [2]  24, 107). 

JHchloracdal  GHC1,*CH(0G,H.),  (Jaoobsen, 
Ber.  4, 217  ;  Pinner,  Ber.  5, 148 ;  Annaten,  179, 
34;  Krey,  l.e,;  Patemd,  Annalen,  149,  372; 
100, 134) ;  b.p.  183''-184'' ;  n.  gr.  11383  at  14^ 
When  treatea  witii  hydrocarDons  it  forms  oom- 
poands  of  the  type  CuX^'CCit  (Fritsch,  Annalen, 
279,219;  WiecbeU,  Annalen,  279, 337 ;  Batten- 
befg,  Annalen,  279,  324). 

Trichhracekd  OCl,-CH(OCaH,),  (Byasson, 
Bull.  8oo.  chim.  32,  304 ;  Wnrtz,  Frapolli,  J. 
1872,  438) ;  b.p.  197'' ;  204-8''  at  768-7  mm. 
Pateni6,  Pisati  J.  1872,  303),  sp.  gr.  1-2813. 
When  heated  with  conoentntod  snlphuric  add 
it  yields  chloral. 

Triehhnuxial  GcHna,0,.  Obtained  by  the 
action  of  chlorine  on  alcohol  (lieben,  Patemb, 
Krey»  ^»c>);  crystallises  in  monodinic  needles 
resembling  caffeine ;  m.p.  89®. 

Mandbromauial  (Pinner,  Ber.  6,  149 ;  Wis- 
lioenns,  Annalen,  192,  112;  Fischer  a.  Lund- 
steiner,  Ber.  26,  2661 ;  Frenndler  a.  Ledm, 
Compt.  rend.  1906,  140,  794) ;  b.p.  8^-82**  at 
27-28  mm.  (Frenndler).  According  to  F.  a.  L.  a 
cheap  method  of  making  monobromacetal  is  by 
brominatin^  paraldehycto  at  0**  with  constant 
shaking,  nuxmg  with  absolute  alcohol,  and  after 
standing  12  hours  pouring  into  an  ice-cold  sd. 
of  potasdum  carbonate.  The  separated  oil  is 
dried  and  fractionated  in  vaeuA, 

MonoiodoaeekU,  b.p.  100**  at  10  mm. ;  sp.  gr. 
1-4944  at  Id*'  (Hesse,  Ber.  1897,  30,  1438). 

Aminoaeetal  NH.*CHsCH(OC,H,)| was  first 
prepared  by  Wohl  bv  treating  chloracetal 
witb  ammonia  (Ber.  21,  616).  It  can  ako  be 
prepared  by  redudng  nitroacetal  (b.p.  14®; 
m.p.  89®-9P,  from  ioaoaoetal  and  silver  nitrite) 
with  sodium  and  alcohol.  It  forms  a  colourless 
oil  of  b.p.  172^-174®,  with  a  strong  amine 
smell;  it  emnlrifies  with  a  little  water,  but 
diaMlves  on  adding  more  water,  and  can  be 
separated  from  the  solution  by  the  addition  of 
soud  alkali.  It  is  of  some  importance  as  a 
synthetic  agent,  as  it  readily  condenses  with 
aromatic  aldehydes  to  form  derivatives  of  iso- 
qulnoline : 

/.    ^OHO  H,N  CH 


u 


+    CH, 


/ 


(C,H40),CH 


CH 


^^  +2C,H,0H 


Snbstitated  alkylaminoaoetals  are  also  known 
(Paal  and  van  Gember,  Aichiv.  der  Phaim. 
246,306;  Stormer and PlraU, Ber.  30, 1604). 

Aceitd  sulphide  (acetal^  sohilude) 
r(G,H.0),-CH-CH^].8  has  been  pimaied  by 
Fischer  (Ber.  42,  1070)  1^  heating  chloncetal 
with  aqneons  potaaBinm  sulphide  at  120°-160®  G. 
It  forms  a  eolouriess  liquid,  b.p.  280®  G.  (750 
mm.).  It  dissolves  readfly  in  water,  from  which 
it  can  be  precipitated  by  salt,  and  is.  decompoeed 
by  boiling  witn  1  p.c  hydrochkric  add. 

Chhro4ri€lki/l^jpiia9pkinoaedal  is  described  by 
CaldweU  (Trans.  Chem.  8oa  109, 283).  Prepared 
by  heatinff  monochloraoetal  and  triethylphos- 
phine ;  it  rarms  a  viscous  liquid  of  overpowering 
odour.  The  flnrrwattniuling  bcomo  oompound  is 
also  described.  They  are  hydrolysed  to  the 
respective  aldehydes. 

Dipropyl  acdal  CH,-GH(0-GJH,)^  b.p.  147® ; 
sp.  gr.  0-825  (22°)  (de  Giran^  Gompt.  rend. 
91,  629). 

Di^nrhuiyl  aedal  GH,-GH-(OG«H,)„  b.p. 
198®-200®  (King  and  Mason,  £ng.  Pat.  101428). 

Di'iso-iuttfl  aedtd  GH,-GH(0G4H,)„  Kp. 
170® ;  sp.  gr.  0*816  (22®)  (Glaus  and  Trainer, 
Ber.  19,  3W)6;  de  Giraid,  Gompt.  rend.  91, 
629). 

Di'iMHMm^  aedal  GH,-GH(GG,Hi,)„  b.p. 
211®;  sp.  or.  0-835  (15®)  (Alsbog,  Jahreeb.  I. 
Ghemie.  1864,  485 ;  Glaus  and  Trsiner,  I.e.). 

Various  other  aoetals  have  been  prepared* 
but  are  for  the  most  part  unimportant;  the 
following  may  be  noted : — 

AcnMn  dtetikyi  aeeUd  GH. :  GH-GH(OG»Hs)., 
b.p.  123-5®;  sp.  gr.  0*8453  (15®);  R>tfingly 
soluble  in  water,  miscible  with .  alcohol  and 
ether;  hydrolysed  by  cold  hydrochloric  acid 
(Wohl,  Ber.  31,  1796.  For  reactions,  see  Wohl, 
I.C.;  Wohl  and  Emmerich,  Ber.  33,  2761; 
Wohl  and  Schwdtcer,  Ber.  40,  92).  Acrolein 
itseU  reacts  with  orthoformio  ester,  kc,  to 
yidd  the  ethaxy  derivative  of  propicmaldehyde 
aceUd GH,(0G,H4)-CH,-GH(0GiH J„  b.p.  184®- 
186®  (Claisen,  Ber.  29,  2933  ;  31,  1014 ;  Fischer 
and  Giebe,  Ber.  30, 3066).  Simibrly,  crotonalde- 
hyde  yields  fi-ethoxy-butyraildehyde  aedal 
GH,-CH(OG,H,)-GH,.GH(OG,Hj)„  b.p.  73®- 
74®/  14  mm.  (Giaisen,  Z.c). 

CfoUyiuMehyde  diethffi  aceUd,  see  Wohl  and 
Frank  (Ber.  35, 1904). 

Propargyldldehjfde  diethf/l  acetal 
GH:G<3H(0G,H,), 

forms  an  oil  with  a  camphor-like  odour,  b.p.  140® 
(Claieen,  Ber.  29,  2933;    31,  1016,   1022;  36, 
3664,3668;  40,3907). 
Qlycerine  aldehyde  acetal 

GH,(OH)GH(OH)-GH(OG,H,), 

from  acrolein  acetal  (Wohl,  Ber.  31,  1799). 

Aoetals  derived  from  ketones  can  be  obtained 
by  the  action  of  the  hydrochlorides  of  f ormimino- 
ethers  or  phenylacetimino-ethers  (Claisen,  Ber. 
31,  1012;  40,  3908;  Rdtter  and  Hess,  Ber. 
40,3023). 

Acetone  dimethyl  acetal  (CH,),-C(OCH,)„ 
b.p.  83. 

Acetone  diethyl  acetal  (CHJ,-C(OC,Hjj, 
b.p.  114®. 


ACETALS. 


9 


Glycol  aeeUd,  see  Fumer  (Ber.  5,  160),  Verley, 
(Chem.  Zentr.  1899,  ii.  919). 

Bikifl  glyoxtd  acdal  CtH,0*Cfi(00«H,)„ 
b.p.  62*'-68''  / 10-12  mxn.  (Dakin  and  Dudley, 
Trans  Chem.  Soo.  106,  2463;  c/.  also  Am. 
Chem.  Abstr.  7,  3343  ;  8,  2262). 

The  monoeaochaiides  form  derivatiTes  termed 
glucosides  (9. v.),  which  are  related  to  aoetals, 
and  it  is  probable  that  the  true  aoetals  are 
intermediate  products  in  their  formation : 

HO-CH,[CH(OH)1j5CHO+2HOCH, 

=H,0+HOCH,[CH{OH)ltCH{OCH,), 

and  these  acetals  then  split  off  one  moleoule  of 
alcohol  to  form  the  glucosides  (£.  Fischer,  Ber. 
28,  1146),  which  are  thus  the  oyclic-7-anhydro 
deriyatives  of  the  half -acetals  of  the  mono- 
saccharides. 

Aromatle  aeetols.  The  mono-  and  di-  acetal 
derivatives  of  catechol  are  obtained  by  heating 
the  monosodium  derivative  of  catechol  with 
monochloracetal  (Moreau,  Compt.  rend.  126, 
1666). 

Vertey  describes  the  production  of  methyl 
acetals  ol  aromatic  glyc<us  which  are  jasmine 
perfumes,  and  may  oe  prepared  synthetically 
or  from  natural  extract  of  jasmine,  which  con- 
sbts  essentially  of  the  methyl  acetal  of  phenyl 
glycol  (Eng.  Pat.  4779,  1898) ;  this  suhstanoe : 

/Y^H,-CH. 

^^    O         O 


is  produced  by  heatins  phenyl  slycol  and 
formic  aldehyde  with  dilute  sulphuric  acid. 
It  forms  an  oil,  b.p.  101^  /  12  mm.,  and  is 
identical  with  the  natural  perfume.  If  acetal- 
dehyde  be  used  in  place  of  formaldehyde  the 
ethyl  acetal  is  formed,  b.p.  103°  / 12  mm. 

DiethyWenzaldehyde  acetal  CeH^CHCOCsHt). 
may  be  prepared  by  the  method  of  Fischer  and 
Giebe  (Cc)  bv  treating  the  aldehyde  with  6 
times  its  weight  of  1  p.c.  ethyl  alcoholic  hydro- 
chloric acid,  and  heating  to  100°  for  60  hours, 
cooling,  diluting  with  water,  and  extracting 
with  ether ;  or,  better,  by  Claisen's  method : 
37*6  grams  benzieddehyde,  67  fframs  orthoformio 
ester,  and  49  grai&s  alcohol,  and  0*76  gram 
ammonium  chloride  are  refluxed  for  10  minutes. 
The  product  is  then  distilled  from  the  accom- 
panying formic  ester  (b.p.  82°),  and  after  further 
purification  with  potassium  carbonate  is 
nactionated,  the  acetal  diwtiUing  over  between 
217°  and  223°.  Yield  62  mms  or  97  p.c.  of 
theory.  A  trace  of  h^drocnloric  acid  may  also 
be  used  as  a  catalyst  m  place  of  the  ammonium 
chloride  (Chusen,  I.e.). 

(6)  Acidyl  derivaiives  of  gem-Olycole. 

The  diaoyl  derivatives  corresponding  to  the 
true  aoetals: 

5;>c(o-coR,), 

(Ri  and  R,=alkyl  or  hydrogen)  have  hitherto 
been  of  slisht  importance  in  industry  ;  recently, 
however,  we  diaoetyl  esters  of  ethyhdene  glycol 
have  come  into  prominence  as  a  means  for  the 
production  of  acetic  anhydride.  They  may  be 
prepared    by   condensing    acid  chlorides   wi  h 


carbonyl  compounds  to  a-ohloralkyl  fatty  esters, 
and  then  treating  these  with  silver  or  potassium 
salts  of  the  same  or  different  acids 

CH,-CH<o<X)-CH,+^«0"^"^» 

=Aga+cH.cH<:g:^:^i{;» 

(Schiff,  Ber.  9,  306 ;  Geuther  and  Rubencamp, 
Annalen,  226,  273).  Acidyl  derivatives  of 
methylene  glycols  can  be  obtained  by  treating 
methylenedihalogenides  with  the  sUver  salts  m. 
fatty  acids : 
CH,I,-f2AgOCOCH,=2AgI-fCH,(OCOCH,), 

(Butlerow,  Annalen,  107,  111;  Amhold, 
Annalen,  240,  204),  or  by  condensing  polyoxy- 
methylenes  with  acid  chlorides  or  anhydrides 
in  presence  of  zinc  chloride 

RCO>^"^^"«"    R-COO>^"" 

(Descud6,  Bull.  Soc.  chim.  [3]  27,  867). 

The  following  derivatives  are  known  i-^ 

Mdhylene  diacdaU  CHJOCOCH^,,  b.p. 
170°  (Butlerow,  Annalen,  107,  111 ;  Descudd, 
Bull.  Soc.  chim.  [3]  27,  1216). 

Eihylidene  diacetaU  CH,CH(OCOCU,).,  b.p. 
169°;  sp.  gr.  1073  (16°)  (Geuther,  Annalen, 
106,  249;  Schiff,  Ber.  9,  306;  Franchimont, 
Rec.  trav.  chim.  1,  248 ;  Geuther  and  Ruben- 
camp,  Annalen,  226,  273). 

Eihylidene  dipropionate  CH|CH(OCOC,Hs)„ 
b.p.  192°;  sp.  gr.  1-020  (16^)  (Geuther  and 
Rubencamp,  Ic. ;  cf.  also  Eng.  Pat.  14246, 1913). 

Eihylidene    dtbiOyraU    C^s-CH(OCO0,H;)„ 
b.p.   216°;    sp.  gr.  0986  (16°)  (Geuther  and 
Rubencamp,  i.c.). 
'  EihyUaene  di-i»otnlerianate 

CH,-CH(0C0-C4H,)„ 
b.p.  226°;     sp.  gr.  0*947  (16°)  (Geuther  and 
Rubencamp,  I.c), 

Of  these  ethyUdene  diaeekUe  is  hj  far  the 
most  important ;  it  is  now  made  technically  by 
passing  aoetvlene  into  acetic  acid  containing 
a~meroury  salt  as  catalyst 

C,H,-f  2CH,C00H= CH,CH(0  COCH,) , 

TheChemisch  Fab.  Griesheim  Elektron  (Eng. 
Pat.  14246,  1913)  claim  the  prodnotion  of  esters 
of  ethylidene  glycol  and  vmyl  alcohol  by  the 
action  of  acetylene  upon  compounds  containing 
carboxyl  groups  in  the  presence  of  mercury 
salts ;  the  esters  are  stated  to  be  solvents  for 
cellulose  esters;  in  an  example,  260  grams  of 
anhydrous  acetic  acid  are  mixed  with  10  grams 
mercury  sulphate  and,  at  60°-80°  C,  dry 
acetylene  is  passed  through  until  action  ceases. 
'Ae  product  on  distillation  yields  80-00  p.c.  of 
the  theoretical  amount  of  the  ester. 

Boiteau  (Eng.  Pat.  16919,  1914)  claims  a 
modification  consisting  in  forming  the  required 
catalyst  in  the  substance  heated.  For  example, 
mercuric  oxide,  or  a  mercury  salt  of  a  weak 
acid,  such  as  acetic  acid,  is  (Ussolved  in  slacial 
acetic  acid,  sulphuric  acid  is  then  added,  and 
acetylene  passed  in. 

The  Soc.  Chim.  des  Usines  du  Rh6ne  describe 
(Eng.  Pat.  112766)  a  further  modification  in 
which  ethylidene  diacetate  is  prepared  bv  the 
reaction  of  acetylene  on  glacial  acetic  acid  m  the 
presence  of  mercury  acetate  and  aromatic  or 
aliphatic  sulphonic  acids.     In  Eng.  Pat.  112766 


10 


ACETAL8. 


the  same  patentees  claim  also  the  use  of  mercury- 
acetate  uid  sulphnrio  eaten,  eg.  methylene 
snlphato. 

The  dJAoetio  ester  obtained  by  any  of  these 
proceeaes  splits  up  on  heating  into  acetaldehyde 
(or  paraldenyde)  and  aoetio  anhydride : 

CH,CH(OCOCH,),=CH,CHO+0(CO-CH,), 

Thus,  the  Bosnische  Elektrizitats  A.  Q.  (En^. 
Pat.  23190,  1914)  claim  the  production  of  acetic 
anhydride  by  heating  ethylidene  diacetate  above 
its  boiling-point,  or  by  heating  it  with  catalysts, 
such  as  sulphuric  acid  or  mercuric  sulphate. 
The  Soc.  Chmi.  dee  Usines  du  Rhdne  (£ng.  Pat. 
110906)  describe  the  production  of  acetic 
anhydride  and  paraldehyde  by  heating  ethylidene 
diacetate' under  reduced  pressure  in  tne  presence 
of  catalysts,  such  as  acids  or  acid  salts.  For 
instance,  400  parts  of  the  ester  and  8  parts  of 
sulphuric  acid  (66^  B6.)  are  placed  in  a  suiteble 
vessel  and  heated  to  70^-80^0.  at  a  pressure  of 
100  mm.  In  two  hours  350  parte  of  a  mixture 
of  paraldehyde  and  acetic  anhydride  distil 
over.  (The  boiUng-point  of  ethylidene  diacetete 
.  at  100  mm.  is  about  1 IS^'  C.)  (Of.  also  Eng.  Pat. 
131399,  Soc.  Chim.  des  Usinos  du  Rhdne.)  The 
diacetete  can  also  be  made  by  heating  acetalde- 
hyde with  acetic  anhydride  (Greuther,  Annalen, 
106,  249),  but  the  yield  is  poor,  and  the  method 
is  without  technical  importance. 

Bemylidene  diaceiaU  0«HsCH(OCOCH,)„ 
m.p.  46*»-46* ;  b.p.  220*  (226^-230*),  can  hb 
prepared  by  heating  20  grams  benzyl  chloride 
witn  36  grams  lead  peroxide  and  80  c.c.  boiling 
acetic  acid  (Bodroux,  BuU.  Soc.  chim.  [3]  21, 
331) ;  by  refluxing  20  grams  benzaldehyde  with 
20  grams  acetic  anhydride  and  10  grams  acetic 
acid  for  3  hours  at  ISO^-ISO"*  (Nef,  Annalfen, 
298,  277),  or  by  passing  air  through  a  mixture 
of  benzaldehyde  and  acetic  anhydride  containing 
a  trace  of  acetic  acid  (Freer  and  Novy,  Am. 
Ghem.  J.  27,  160).  In  complete  absence  of 
acetic  acid  no  action  occurs.  It  is  only  slowly 
attacked  by  boiling  with  sodium  carbonate 
solution  or  "by  treatment  with  soda  Ive,  but  is 
hydrolysed  by  cold  concentrated  sulphuric  or 
nitric  adds.  {Cf.  also  Wicke,  Annalen,  102,  368  ; 
Qeuther,  ibid.  106,  251 ;  Limpricht,  ibid.  139, 
321 ;  Beilstein  and  Kuhlberg,  ibid.  146,  323 ; 
and  Zeit.  f.  Chemie.  1867,  277;  1868,  172; 
Chem.  Zentr.  1908,  1,  1831 ;  1909,  2,  1220.) 

F.  A.  M. 

ACETAMIDE  C,H,NO,  or  CH,.CONH,.' 
(Hofmann,  Ber.  15, 980;  Schulze,  J.  pr.  Chem. 
[2]  27,  512;  Keller,  J.  pr.  Chem.  [2]  31,  364; 
Aschan,  Ber.  31,  2344 ;  Kundig,  Annalen,  105, 
277;  Abel,  J.  Soc.  Chem.  Ind.  1899,  51^) 
Acetemide  is  usually  prepared  by  the  dry 
distillation  of  ammonium  acetate ;  a  better  yield 
(91*7  p.c.)  and  a  purer  product  is  obtained  by 
distilling  ammonium  diacetete  in  the  special 
apparatus  described  by  FranQois  (J.  Pnarm. 
Chim.  23,  230).  Between  136*  and  195*  acetic 
acid  and  water  are  evolved,  and  at  195*- 
222*  some  acetemide  passes  over.  When  the 
temperature  remains  constent  at  222*  the  dis- 
tillation is  stopped,  the  residue  beins  pure 
acetemide.  A  nearly  theoretical  yield  is  obtemed 
by  saturating  a  mixture  of  ethyl  acetete  and 
ammonia  wiw  dry  ammonia  gas  at  — 10*,  and 
after  stending,  fractionating  in  vacud  (Phelps, 
Amer.  J.  Soi.  24, 429). 


Acetamide  forms  white  hexagonal  crystals 
which  are  odourleas  when  pure,  and  melt  at 
81*-82*  (Hofmann,  Ber.  14,  2729 ;  Mason,  Chem. 
Soo.  Trans.  1889,  107 ;  Meyer,  Ber.  22,  24 ; 
Forstor,  Chem.  Soc.  Trans.  1898,  791;  Nicol, 
Zeitsch.  anoi^.  Chem.  15,  397),  boils  at  222* 
(cor.)  [Kiindig],  is  readily  soluble  in  water, 
and  when  heated  with  acids  or  alkalis  is  con- 
verted into  aoetio  acid  and  ammonia  (Coninck, 
Compt.  x«nd.  121,  893  ;  126,  907  ;  127,  1028 ; 
Dunsten  a.  Dymond,  Qiem.  Soc.  Trans.  1894, 
220;  Guebet,  Compt.  rend.  129,  61).  Chlorme, 
led  into  fused  acetamide,  yields  acetehloramide 
CHa'CONHCl;  and  bromine,  in  the  presence  of 
dilute  aqueous  potash  or  soda  yields  acetbrom- 
amide,  which  on  distillation  with  concentrated 
aqueous  soda  is  converted  into  methylamine 
(Hofmann,  Ber.  15,  408);  Buchner  and  Papen- 
dieck,  Ber.  25,  1160;  Selivano£f,  Ber.  26,  423; 
Fran9oi8,  Compt.  rend.  147,  680;  148,  173; 
Behrend  a.  Schreiber,  Annalen,  318,  371). 
Acetemide  acts  both  as  a  base  and  an  acid 
(Pinner  and  Klien,  Ber.  10, 1896),  combining  with 
hydrogen  chloride  or  nitric  acid,  and  formins 
compounds  in  which  a  metel  tekes  the  place  (u 
oneatomof  hydrogen,  as  C|H,0'NHAff  (Strecker, 
Annalen,  103,  321 ;  Tafel  and  Enock,  Ber.  23, 
1550;  Bhhcher,  B«r.  28,  432;  Hofmann  and 
Bagge,  Ber.  41,  312;  Titherley,  Chem.  Soc 
Trans.  1897,  467).  According  to  Forster  (Chem. 
Soo.  Trans.  1898,  783),  mercury  aoetemide  is  a 
powerful  dehydrogenising  agent  and  owins  to  ite 
tendency  to  exchange  ite  mercury  for  hydrogen 
when  the  latter  is  atteched  to  nitrogen,  particu* 
larly  when  hydroxyl  groups  are  in  proximity, 
it  can  be  employed  as  a  convenient  means  of 
detecting  primary  and  secondary  hydrar.ines 
and  primary  hyuroxylamines.  It  has  also  a 
marked  tendency  to  form  additive  compounds 
(Morgan,  Chem.  Soc  Proc.  1906,  23).  The 
hydrogen  in  the  NH,  group  has  also  been  replaced 
by  alkyl  groups  (Titherley,  Chem.  Soc  Trans. 
1901, 396, 411, 413).  Acetemide  forms  molecular 
compounds  of  the  type  CH,*CONH|,X,  where 
X  =  an  organic  or  inorganic  acid  or  an  inorganic 
salt  (Titherley,  {.c. ;  ^pin,  Ann.  CShim.  Phys. 
[7]  5,  99).  When  acetemide  is  treated  with 
formaldehyde,  paraldehyde,  or  trioxymetihylene, 
condensation  producto  of  the  type  R-NH-CHgOH 
are  obteined;  these  producto  are  of  value  as 
antiseptics  and  as  solvente  for  uric  acid  (J.  Soc. 
Chem.  Ind.  1906,  283).  Mono-,  di-,  and  tri- 
chloracetemide  (Willm,  Annalen,  102,  110; 
Geuther,  J.  1864,  317 ;  Pinner  and  Fuchs,  Ber. 
10,  1066 ;  Malasuti,  Annalen,  56,  286 ;  aoez, 
Annalen,  60,  261 ;  Bauer,  Annalen,  229,  165 ; 
Dootson,  Chem.  Soc.  Trans.  1899,  171 ;  Swartz, 
Chem.  Zentr.  1899,  [L]  588 ;  Clermont,  Compt. 
rend.  133,  737).  Bromo-dialkyl-acetemide  (J* 
Soc.  Chem.  Ind.  1904,  1238)  and  other  halogen 
derivatives  have  also  been  prepared  (Selivanoff, 
J.  Russ.  Phys.  Chem.  Soc.  24,  132;  Broohe, 
J.  pr.  Chem.  T2],  50,  97 ;  Conrad,  Ber.  29, 1042 ; 
Zinoke  and  Kegel,  Ber.  23,  230;  Willstatter,  Ber. 
37, 1775;  Steinkopf,  Ber.  41,  3571  ^  Swartz,  Lc; 
Francesconi,  Qazz.  chim.  iteL  33,  226 ;  Batz, 
Monatsh.  1904,  25,  687;  Einhom,  Annalen, 
343, 203;  Finger,  J.  pr.  Chem.  1906,  [ii]  74, 153). 

The  acetemido  /3-naphthaquinones  and  some 
of  their  halosen  derivatives  which  may  be  used  in 
dyeing  (Kenrmann  and  Zimmcrli,  Matis,  and 
Locker,  Ber.  31, 2405;  Kehrmann  and  Aebi,  Ber. 


AOBTANILIDE. 


U 


32,  932 ;  KAhrmann  and  Wolfi,  Ber.  33,  1538) 
and  other  acetamide  derivatives  have  been  pre- 
pared (J.  Soc.  Chem.  Ind.  1894,  60;  Lumi&re, 
Bull.  Soc.  chim.  1903,  ilL  30, 966;  Ratz,  Monatsh. 
26,  1487 ;  Miolati,  Gazz.  chim.  ital.  23,  190). 

Diaeetamide  O^H^NO,,  or  NH(0,H30),  and 
its  derivatiyes  {see  Gautier,  Z.  1869,  127 ; 
Hofmann,  Ber.  14,  2731;  Hentschel,  Ber.  23, 
2394;  Curtius,  Ber.  23,  3037;  Mathews,  Amer. 
Chem.  J.  20,  648;  Konig,  J.  pr.  Chem.  1904,  [ii.]' 
69,  1;  Troeger,  J.  pr.  Chem.  69,  347;  Triacet- 
amide  C,HsKO„  or  N(CsH,0),  and  its  deriva- 
tives (Me  Wiohelhaos,  Ber.  3,  847). 

ACETAHIUDB  O^jNHCOCH,,  also 
known  as  Antifebrin,  ia  prepared  by  heating 
together  glacial  acetic  ada  and  aniline  for  some 
time. 

For  an   account   of  its  preparation   on   a 

manufacturing   scale,  see  MuUer,   Chem.   2ieit. 

'    1912,  36,  1055  :   quoted  by  Cain,  *  Manufacture 

of  Intermediate  Products  for  Byes/  Macmillan 

&  Co.,  p.  61. 

By  substituting  thioacetic  acid  for  acetic  acid 
the  reaction  proceeds  more  rapidly  and  at  a 
lower  temperature  (Pawlewski,  Ber.  1898,  661). 
Aoetanilide  may  also  be  prepared  by  heatixig 
1  part  of  aniline  with  1}  parts  of  dilute  acetic 
acid  or  of  crude  p3rroligneou8  acid  under  pressure 
at  150^-160*'  (Matheson  &  Co.,  Eng.  Pat.  6220 
and  D.  R.  P.  98070 ;  J.  Soc.  Chem.  Ind.  1897, 
659). 

A  simple  laboratory  method  consists  in 
gently  boning  a  mixture  of  equal  weights  of 
aniline  and  acetic  acid  with  2-  3  p.c.  of  zinc 
chloride  under  a  reflux  condenser  tor  3  hours, 
when  the  whole  is  poured  into  water  and  the 
acetanilide  re-GrystauiBed  from  water.  The  use 
of  pure  aniline  obviates  the  necessity  of  de- 
coloriaing  with  animal  charcoal. 

The  substance  melts  at  114*2°  (Beissert,  Ber. 
1890,  2243),  at  115''-116''  (Hantzsch  and  Eresae, 
Ber.  1894,  2529),  and  boils  without  decomposi- 
tion at  303-8''  (oorr.)  (Pictet  and  Cr6pieux,  Ber. 
1888,  1111),  at  305''  (corr.)  (Perkin,  Chem.  Soc. 
Trans.  1896,  1216) ;  it  is  soluble  in  hot  water, 
alcohol,  or  ether. 

Acetimilide  is  hydrolyaed  at  100°  by  caustic 
potash  or  by  ^drochloric  acid,  but  not  by' 
sulphuric  acid  (Btantzsch  and  Fresse,  Ber.  1894, 
2529);  it  is  rapidly  decomposed  by  chromic 
add,  liberating  carl)on  dioxide,  and  producing 
colouring  matters  (De  Coninck,  Compt.  rend. 
1899,  503).  It  reacts  with  zinc  chloride  at  180° 
with  the  formation  of  the  yellow  dye  flavaniline 
(Brautigam,  Pharm.  Zeit.  44,  75). 

By  treating  a  solution  of  acetanilide  in 
sulphuric  acid  with  a  mixture  of  nitric  and 
sulphuric  acids  and  hydrolysing  the  product,  it 
is  converted  into  p-nitroamline 


NH 


■<: 


\ 


NO, 


Acetanilide  is  present  in  the  urine  of  cows 
(Petermann,  Ann.  Chim.  anal.  1901,  165).  It  is 
largely  used  in  headache  powders  and  to  adulte- 
rate drugs,  such  as  phenacetin.  It  seems  to 
act  physiologicaliy  by  the  slow  liberation  of 
*^'1i"<»^  and  may  thus  give  rise  to  aniline  poison- 
ing. It  is  oxidised  to  some  extent  in  the 
b(xiy  to  p-aminophenol.  For  methods  of 
estimation  v.  Puckner,  Ph.  Rev.  1905,  302, 
and  Seidell,  Amer.  Chem.  J.  1907,  1091.     The 


following  reactions  may  be  used  for  detecting 
its  presence :  (1)  bromine  water  added  to  a 
solution  of  acetanilide  in  acetic  acid  gives  a 
white  crystalline  predpitate  of  p-bromacetani- 
lide,  m.p.  167° ;  (2)  evaporation  of  a  solution 
to  dryness  with  mercurous  nitrate  gives  a 
green  mass,  changing  to  blood  red  on  aiddition 
of  a  drop  of  concentrated  sulphuric  acid;  (3) 
ferric  chloride  gives  no  blood-red  colouration 
with  acetanilide,  thus  distinguiflhing  it  from 
phenacetin  and  antipyrine. 

D&riixUivea. — Chloracetanilides  (Jones  and 
Orton,  Chem.  Soc.  Trans.  1909,  1056) ;  Nitro- 
aoetanilides  (HoUeman  and  Sluiter,  Bee.  trav. 
chim.  1906,  208). 

ACETIC  ACID.  Acide  AcUique.  Essigsdure. 
Acidum  Aceticum.  CaH^G,  t.e.  CH,COOH,  or 
CjH.OOH. 

Acetic  acid  occurs  in  nature  in  the  juices  of 
many  plants,  especially  trees,  either  as  free  acid 
or,  generally,  as  the  caldum  or  potasdum  salt ; 
and,  in  the  form  of  orcanic  acetates,  in  the  oils 
from  many  seeds.  It  is  stated  to  be  present  in 
larger  quantities  when  the  plants  are  kept  from 
the  light.  It  exists  in  certain  animal  fluids ; 
B6chimip  states  it  to  be  a  normal  constituent 
of  milk.  Gmelin  and  Geiger  have  found  it  in 
mineral  waters,  doubtless  from  the  decomposition 
of  organic  matter. 

Being  a  very  stable  body  both  at  the  ordinary 
and  at  msh  temperatures,  it  is  found  as  a  pro- 
duct of  me  decompodtion  or  destructive  dis- 
tillation of  many  organic  substances.  Acetic 
acid  was  first  shown  by  Lavoisier  to  be  formed 
by  the  oxidation  of  alcohol.  Its  true  compod- 
tion  was  ascertained  by  Berzelius  in  1814,  and 
in  1821  E.  Davy  (Schwdgger's  J.,  1821,  1,  340) 
proved  that  it  was  formed,  together  with 
water,  by  the  oxidation  of  alcohol,  without  the 
formation  of  carbonic  acid  as  had  been  previoudy 
supposed.  It  was  this  observation  which  led 
Dobereiner  {ibid.  8,  321)  to  explain  acetic 
fermentation  as  a  simple  process  of  oxidation. 

Preparation. — ^Acetic  acid  is  produced  by  the 
oxidation,  decomposition,  and  destructive  dis- 
tillation of  many  organic  bodies.  The  greater 
part  of  that  used  in  commeree  is  obtained  by 
the  destructive  distillation  of  wood. 

Hawley  and  Palmer  (Eighth  Int.  Cong.  Appl. 
Chem.  1912  [4]  Grig.  Comm.  6,  138)  have  shown 
that  the  temperature  within  the  retort  above 
320°  has  but  little  influence  on  the  yidd  of 
acetic  acid  obtained  in  the  destructive  distilla- 
tion of  wood.  They  obtained  the  following 
average  amounts  of  100  p.c.  acid  from  samplco 
of  the  body  wood  and  dabs  {i.e.  body  wood  and 
bark  together)  of  the  hard  woods  commonly 
used  for  the  distiUation  in  U.S.A. :  Birch,  6*50 ; 
beech,  5*55 ;  maple,  4*95 ;  red  gum,  5*16 ; 
chestnut,  5*32  ;  hickory,  4'61 ;  and  oak,  4*70 
p.c,  calculated  on  the  o^  weight  of  the  wood. 

Acetic  acid  may  also  be  obtained  by  boiling 
sawdust  with  water  under  a  pressure  of  6  atmos. 
Under  these  conditions  Bcrgstrom  (Papierfabr. 
1913,  11,  305)  obtained  from  117  to  1-37  p.c. 
of  acetic  acid,  and  0*19  to  0'23  p.c.  of  formic 
acid  from  coniferous  woods  (spruce,  pine),  and 
more  than  twice  as  much  acetic  acid,  and  rather 
less  formic  acid  from  birch  and  other  deciduous 
woods.  Analogous  results  were  obtained  by 
destructive  distillation  of  the  woods,  and  for 
this  reason  lime  acetates  made  from  the  wood 


12 


ACfiTANILlDE. 


of  decidaoos  trees  contain  leas  formic  acid  than 
those  prepared  from  coniferous  wood. 

In  Raisin's  process  (Fr.  Pats.  446871  and 
446878,  1911)  sawdust  is  hydrolysed  at  about 
150^  by  means  of  sulphurous  acid  and  steam, 
and  the  acid  vapours  are  condensed  and  neutral- 
ised with  soda.  Calvert  (Eng.  Pat.  10687, 
1913)  claims  a  method  of  producing  acetic  acid 
by  the  destructive  distillation  of  coffee  husks 
in  a  retort  provided  with  a  screw  conveyor. 

In    1910   the   amount   of   acetate   of   lime 

Produced  in  U.S.A.  from  hard  woods  was 
52,772,000  lb.3.,and  the  amount  of  acetic  acid 
in  1909  was  51,963,000  lbs.,  the  bulk  of  which 
was  used  in  the  manufacture  of  dyes  and  paper 
(Palmer,  Oil,  Paint,  and  Drug  Rep.  March  9, 
1914). 

A  method  of  obtaining  acetic  acid  by  the 
destmotive  distillation  of  ooal,  lignite,  ftc,  has 
been  patented  (Behrens,  Ger.  Fat.  275049, 
1913).  Ethylenic  compounds  are  isolated  from 
the  gases  by  means  of  sulphuric  add,  mixed 
with  carbon  dioxide,  uid  heated  to  about  400**. 
About  75  p.c.  of  the  ethylenic  compounds  are 
thus  converted  into  aoetafdehyde,  which  is  then 
oxidised  to  acetic  acid  (vide  infra). 

Manujadure  of  Acetic  Acid  from  Alcohol, — 
Alcohol  may  be  converted  into  aoeUc  acid  by 
powerful  oxidising  agents,  such  as  chromic 
acid,  nitric  acid,  Ac.  Advantage  may  be  taken 
of  the  fact  that  spongy  platinum  or  platinum 
black  has  the  property  of  absorbing  oxygen,  and 
thus  acting  as  a  powerful  oxidising  agent.    If 

3K>ngy  platinum  oe  placed  over  a  vessel  of 
cohol  with  free  access  of  air,  the  platinum 
absorbs  at  the  same  time  the  oxygen  and  the 
alcohol  vapour,  which  combine  Sad  produce 
acetic  acid  and  water : — 

CH,CH,OH+0,=CH,COOH+OH, 
Alcohol.  Acetic  add. 

In  addition  to  acetic  acid,  aldehyde  (acetic 
aldehyde)  is  produced,  which  is  intermediate 
in  coinposition  between  alcohol  and  acetic 
acid.  It  is  formed  by  the  removfd  of  two 
atoms  of  hydrogen  from  the  alcohol  and  their 
replacement  by  an  atom  of  oxygen : — 

CH,'CH,OH+0=:CH,CHO+H,0 
Alcohol.  Aldehyde. 

In  presence  of  excess  of  oxygen  aldehyde 
forms  acetic  acid.  Aldehvde  is  a  very  volatile 
liquid,  and  is  liable  to  be  lost  before  its  conver- 
sion into  acetic  acid ;  it  is  therefore  neoessaiy  in 
all  cases  where  acetic  acid  is  produced  by  the 
oxidation  of  alcohol  to  allow  free  access  of  air. 

This  method  produces  a  very  pure  acetic 
acid,  but  on  account  of  the  initial  cost  of  the 
platinum  (whidi,  however,  is  not  in  any  way  in- 
jured by  use)  it  is  not  extensively  used  on  the 
manufacturing  scale. 

Numerous  patents  have  been  taken  out  for 
the  oxidation  of  alcohol  or  acetaldehyde  to 
acetic  acid.  In  Behrens*  process  (Ger.  Pat. 
223308,  1908)  alcohol  is  oxidised  to  aldehyde  by 
the  action  of  air  in  the  presence  of  platinum  as 
catalyst.  The  aldehyde  is  separated  by  frac- 
tional distillation,  and,  after  the  addition  of 
dilute  sulphuric  acid  to  make  it  electrically 
conductive,  it  is  electrolytically  oxidised.  The 
bulk  of  the  acid  produced  may  then  be  recoveied 
by  a  single  distillation  in  a  column  still. 

In  a  later  patent   of   Behiens  (Eng.   Pat. 


I  28839,  1910),  the  alcohol  is  oxidised  by  the 
catalytic  action  of  zinc  oxide  at  about  350^ 
9sdA  the  aldehyde  then  oxidised  by  contact  with 
oxysen  in  an  absorbing  tower. 

According  to  anotner  process  patented  by 
the  Chem.  Fabr.  Grieaheim-Elektron  (Eng.  Pat. 
17424,  1911),  acetaldehyde  is  oxidised  by  means 
of  air  in  the  presence  of  acetic  acid  or  a  chlorine 
derivative  thereof,  a  catalyst,  such  as  vanadium 
pentoxide,  or  uranium  oxide,  being  also  used  to 
promote  the  reaction;  or  the  aldehyde  may 
first  be  oxidised  by  exoess  of  oxygen  (Eng.  Pat. 
8076,  1912). 

'ihib  addition  of  small  amounts  of  manganese 
compounds  promotes  the  oxidation,  without  the 
risk  of  explosion  attending  the  use  of  compounds 
of  vanadium,  chromium,  or  cerium  (Consortium 
Elektrochem.  Ind. ;  Fr.  Pat.  460971,  1913). 

By  mixing  the  acetaldehyde  with  about  1 
p.c.  of  eerie  oxide  or  other  catalyst,  and  treating 
it  with  oxygen  under  a  pressure  of  about  2 
atmospheres,  or  with  air  at  about  5  atmospheres, 
about  95  p.c.  of  the  theoretical  yield  of  anhydrous 
acetic  acid  is  obtainable  (Farbenwerke  voim. 
Meister,  Lucius  and  Bruning ;  Eng.  Pat.  10377» 
1914). 

The  Badische  Anilin  u.  Soda  Fabr.  (Ger.  Pat. 
294724,  1914)  has  claimed  a  process  of  oxidising 
acetaldiehyde  by  means  of  air  or  oxygen  in  the 
presence  of  iron  compounds  and  organic  salts 
of  alkalis,  alkaline  earths,  aluminium  or  mag- 
nesium. The  reaction  is  stated  to  take  place 
rapidly,  and  without  the  aid  of  heat,  whilst  no 
per-acids  are  produced. 

In  Hlbbert's  process  (U.S.  Pat.  1230899, 
1917),  wood  charcoal  previously  saturated  with 
strong  acetic  acid  is  used  as  the  contact  material 
for  the  oxidation  of  acetaldehyde  by  means  of 
oxycen. 

Manufaciure  from  Acetylene, — ^A  French 
patent  (360249,  1906)  describes  the  preparation 
of  acetic  acid  from  acetylene.  Acetylene  is 
passed  into  a  solution  of  a  normal  mercuric 
salt,  which  precipitates  mercury  aoetylidc. 
The  liquid  ia  then  boUed,  when  aldehyde  is 
formed  and  the  mercuric* salt  re-formed.  The 
aldehyde  is  then  oxidised  to  acetic  acid. 

An  electrolytic  process  of  oxidisinff  acetylene 
to  acetic  acid  has  tocu  patented  by  the  Farben- 
fabr.  vorm.  Bayer  u.  Co.  (Fr.  Pat.  467778,  1913), 
the  acetylene  being  oxidised  by  the  use  of  a 
solution  of  sulphuric  acid  or  other  acid  as 
electrolyte,  in  presence  of  a  mercury  compound. 
In  another  patent  by  the  same  firm  (Fr.  Pat. 
467515,  1914),  the  acetylene  is  passed  through 
a  solution  of  hydrogen  peroxide,  or  a  persulphate 
at  about  30°-40^,  m  the  presence  of  mercury  or 
a  mercury  compound,  ^e  resulting  liquid  will 
contain  about  25  p.c.  of  acetic  acid. 

The  oxidation  process  may  also  be  accelerated 
by  the  use  of  other  catalysts  in  addition  to 
mercury,  with  or  without  the  simultaneous 
application  of  pressure  (Fr.  Pat.  471253,  1914). 

Acetic  acia  may  also  be  produced  without 
preliminary  isolation  of  acetaldehyde  by  oxidising 
acetylene  in  an  organic  acid  medium,  such  as 
acetic  acid,  by  means  of  oxygen,  acting  in  the 
presence  of  the  requisite  quantity  of  water  and 
of  a  catalyst,  such  as  iron  oxide  or  vanadium 
pentoxide.  The  best  results  are  obtained  by 
introducing  the  acetylene  and  oxygen  alternately 
in  small  quantities  into  the  acid  medium  (Chem. 


ACETANTLIDE. 


IS 


Fabr.    Gri^Bheim-Elektron,    Fr.    Pat.    473168, 
1914). 

Aceiie  Add  bff  FermeniaHon  Processes. — 
Serenl  species  d  bacteria  are  capable  of  oon- 
Yerting  aloohoUc  Uqiiide  into  acetic  add.  The 
Sfwcies  fint  recognisecU  as  f onninff  films  on  sour 
wine  and  yin^ar,  was  termed  Myeoderma  by 
Persoon,  in  1922,  althoogh  he  did  not  associate 
them  with  the  deyelopment  of  acidity.  Even 
since  it  has  been  recoonised  that  the  pellicle 
was  not  the  prodnct  of  yeasts  or  mould-funffi 
the  name  has  snnrived,  and  is  still  frequently 
used  as  a  generic  term  for  the  acetic  bacteria. 
The  TiewB  of  Stack,  pablished  in  1863,  that  the 
Mjfooderma  aceli,  or  '  mother-of-vinegar,'  con- 
sisted of  an  aggregation  of  bacteria  was  not 
accepted  in  1868by  Pasteur;  bat  Cohn,in  1872, 
indaded  these  micro-organisms  among  the 
bacteria. 

Hanwen,  in  1878  {see  Compt.  rend.  Lab. 
Carlsbeig,  1894  [iii] ;  1900  [y.]),  isoUted  three 
speciea,  which  he  tenned  Baderium  aceti, 
B.  PasUunanum^  and  B.  KlUzmgianymf  and 
showed  that  they  differed  from  one  another  in 
form  and  in  the  nature  of  the  pellicles  which 
they  produced  when  grown  in  aiodhoUo  culture 
media. 

Numeroos  other  species  of  acetic  bacteria 
haye  been  described,  such  as  Bacillus  xyUnus 
(Brown,  J.  Ghem.  Boa  1886,  30,  432;  Ploc. 
CheuL  Boa  1887,  87) ;  B.  cxydans^  B,  acdosus, 
B.  aedigenus,  B,  curvus,  B.  xylinoides,  &c. 
(Henneberg,  Oentralbl.  f.  Bakt.  1909,  24,  13) ; 
and  B.  rcmcens  (Beijerinok ;  Gentralbl.  f .  Bakt. 
1898, 4, 209).  Althoiuh  each  of  these  differed  in 
properties  taid  in  producing  different  inyolution 
forms,  there  is  some  reason  for  conduding  that 
some,  at  least,  of  them  are  not  distinct  spedes, 
but  yarieties  modified  by  their  enyironment. 

In  1906  Buehner  and  Qaunt  (Annalen,  1906, 
349,  140)  separated  an  acetic  enzyme  by 
extracting  the  sooglosal  pellide  of  '  mother-of  • 
yiuMar '  with  acetone.  The  preparations  were 
oq;Mu[>Ie  of  oxidising  alcohd  to  acetic  add,  and 
had  also  the  power  possessed  by  the  Uying 
bacteria  of  oxioisiiig  propyl  alcohol  to  propionic 
add.  An  enzyme  separated  in  this  way  from 
Hansen's  B.  aceti  has  been  shown  by  Widand 
(Ber.  1913,  46,  3327)  to  be  capable  of  rei>ladn£ 
palladium  as  a  catalyst  for  the  oxidation  m 
alcohol  into  acetic  add. 

For  the  production  of  acetic  add  from 
alcoholic  '  washes '  by  the  action  of  liying  acetic 
bacteria,  the  liquid  must  contain  a  suitable 
proportion  of  nutrient  substances  (phosphates, 
nitrogenous  substances),  &c.,  and  there  must 
be  a  regulated  supply  of  air  (see  Manufacture 
of  Vinegar,  infra). 

For  the  manufacture  of  the  so-caUed  '  spirit 
add,*  a  crude  yinegar  containing  from  10  to  12 
p.c.  of  acetic  acid  is  first  made  by  a  fermentation 
process  from  an  aitifidally  prepared  wash 
composed  of  potato  spirit  with  nutrient  sub- 
stances. This  is  known  as  Essiasprit  or 
SprOessig,  and  is  a  common  commerdal  product. 
It  Is  concentrated  by  neutralisation  with  lime, 
evaporation  of  the  Uquid  to  dryness,  and  dis- 
tilhmon  of  the  crude  caldum  acetate,  as 
described  below.  Owing  to  its  more  pleasant 
aroma  spirit  add  of  80  p.o.  strength  fetches  a 
higher  price  in  the  market  than  ordinary  acetic 
acid. 


A  process  of  obtaining  acetic  acid  by  a 
fermentation  process  from  the  Japanese  sea- 
weed Fueus  eattnescenee^  has  been  described  by 
Takahashi  (J.  Ghem.  Ind.,  Tokyo,  1916,  19,  30). 
The  seaweed  is  mixed  with  water  and  3  to  5 
p.a  ol  lime,  which  is  added  in  succesriye  small 
quantities,  and  the  mixture  is  kept  at  30**  for 
2  weeks.  The  yield  of  acetic  acia  is  increased 
by  the  addition  of  f  ucose. 

Distillation  of  Acetic  Add, — ^The  concentfoted 
or  gtadal  add  is  usually  prepared  by  the  dis- 
tillation of  a  dry  acetate  with  an  equiyalent 
quantity  of  strong  sulphuric  acid,  or  add 
potasdum  or  sodium  sulpnate. 

Sodium  acetate  is  generally  used.  The 
anhydrous  salt  is  fused  on  sheet-iron  pans,  6  feet 
by  4  feet,  care  being  taken  that  no  sparks  reach 
the  dried  salt,  as  it  would  then  iffnite  and  bum 
like  tinder.  The  mass  is  cooled,  broken  into 
small  lumps,  and  distilled  with  concentrated 
sulphuric  add.  The  first  portion  distilling  con- 
tains the  water,  the  later  portion  is  collected 
and  cooled;  when  crystals  haye  formed  the 
still  liquid  portion  is  vemoyed,  the  crystals  are 
melted  and  redistilled  as  before,  producing  the 
glacial  acid. 

When  a  solution  of  caldum  chloride  is  mixed 
with  a  solution  of  calcium  acetate,  cr3rstalB  of 
calcium  aceto-chloride  CSaC|H40|G35H.O 
gradually  separate.  These  crystals  may  be 
produced  in  compaiatiye  punty  eyen  when 
impure  brown  acetate  of  lime  is  used.  To  obtain 
acetic  add  ordinary  commerdal  or  '  distilled ' 
acetate  of  lime  Ib  mixed  with  the  proper  pro- 
portion of  calcium  chloride,  and  the  solution  is 
concentrated  by  eyaporation  until  it  crystallises ; 
the  mother  liquor  is  poured  from  the  crystals 
and  concentrated  with  the  production  of  a 
second  crop  of  crystals ;  this  is  repeated  until 
about  four  crops  haye  been  produced.  The 
crystals  are  dissolyed  in  water,  filtered  through 
animal  charcoal,  mixed  with  about  10  p.c.  of 
calcium  chloride,  and  recrystaUised.  The  crystals 
are  distilled  with  a  mixture  of  1  part  sulphuric 
add  of  sp.  gr.  1*84  and  2  parts  water,  and  the 
acetic  acid  concentrated  in  the  usual  way.  The 
glacial  acid  may  also  be  prepared  by  the  dis- 
tillation of  di-  or  add-acetate  of  potasdum, 
which,  when  heated,  decomposes  into  acetic 
acid  and  the  normal  potasdum  acetate.  If 
ordinary  acetic  add  be  heated  with  normal 
potasdum  acetate,  the  acid  acetate  ia  formed, 
and  a  weaker  acid  at  first  distils  oyer ;  as  the 
temperature  rises,  the  diacetate  begins  to  decom- 
pose, and  the  (Ustillate  increases  in  strength 
until  the  glacial  acid  passes  oyer.  When  the 
temperature  reaches  300°  the  distillate  becomes 
coloured  from  the  decompodtion  of  the  acid 
(Melsens,  Annalen,  52,  274;  Gompt.  rend. 
19,  611). 

In  Ghute*s  method  of  preparing  acetate  of 
lime  the  yapours  from  oruoe  pyrohgneous  acid 
are  brought  into  contact  with  a  stream  of  water 
mixed  with  lime.  The  temperature  of  the 
liquid  is  kept  at  about  lOO""  by  the  addition  of 
quicklime  (U.S.  Pat.  939980,  1909). 

Scott  and  Henderson  (Eng.  Pat.  6711,  1896) 
purify  the  crude  acetates  by  filing  with  sodium 
hypochlorite  until  nearfy  decolorised.  The 
solution  is  then  cooled  and  allowed  to  settle. 
The  dear  liquid  ii  decanted  and  crystallised.  The 
crystals  are  of  great  purity. 


14 


ACETANILTBE. 


Another  method  of  romoying  organic  impuri- 
ties is  to  boil  the  crade  acetates  with  lime,  an 
iron  salt,  and  a  bleaching  agent  (Zinkeisen, 
U.S.  Pat.  1213724,  1917). 

Scott  (Eng.  Pat.  12952,  1897)  has  patented 
a  process  vhioh  dispenses  with  lime  in  the 
manniaotiire  of  acetic  aeid.  He  distils  the  crude 
acid  at  100%  and  fractionally  condenses  the 
vapours.  The  acid  collects  mainly  in  the  first 
portions. 

Crude  acetates  may  be  decomposed  with 
"RfiO^  or  HGl,  and  the  acetic  add  distilled  in 
noeuo  (Thom^n,  J.  Soc.  Chem.  Ind.  1896, 357) ; 
or  crude  acetic  acid  may  bo  treated  with  oxygen 
under  pressure,  filtered  through  charcoal  and 
distiUea  over  pure  sodium  acetate  (Schmidt, 
Eng.  Pat.  1896,  25100). 

Hochstetter  (J.  Soc.  Chem.  Ind.  1902,  1469) 
prepares  pure  acetic  acid  by  heating  pure  sodium 
acetate  with  dry  Ha  at  120^' ;  whilst  Plater 
and  Sybm  patented  a  process  of  obtaining 
acetic  add  oy  the  electrolysis  of  alkali  acetates. 

According  to  the  patent  process  of  Farben- 
fabr.  vorm.  Bayer  u.  €k>.  (Qer.  Pat.  220705, 
1907)  the  onide  acetote  is  heated  to  about  130'', 
the  pressure  within  the  still  reduced  to  about 
jt  atmosphere,  and  sulphuric  acid  introduced. 
The  disulate  is  olaimea  to  contain  only  traces 
of  sulphur  dioxide. 

In  Prater's  continuous  process  (Fr.  Pat. 
449035,  1911)  sulphuric  addfis  sprinkled  pro- 
gressively on  the  acetate  in  a  series  of  com*- 
partments,  the  material  being  mechanically 
transferred  from  one  compartment  to  the  next, 
whilst  the  liberated  acetic  add  is  condensed  in 
the  upper  part  of  the  apparatus. 

Another  method  of  distiUation  makes  use 
of  a  hot  rotating  surface  upon  which  a  mixture 
ci  acetate  and  sulphuric  add  is  mechanically 
spread.  The  acetic  acid  is  condensed,  and  the 
solid  reddue  ia  removed  from  the  hot  cylinders 
by  means  of  scrapers  (Brauer,  U.S.  Pat.  1196329, 
1916). 

Aromalle  or  ndleal  finegar.— Before  the 
discovery  of  pyroligneous  add  strong  acetic  acid 
was  prepared  by  the  distiUation  of  ordinary 
vinegar,  or  of  orystallised  verdisris,  whence 
it  was  popularly  known  as  diHuUd  verdigris. 
This  product,  which  was  distilled  from 
earthenware  retorts,  formed  the  aromatic  or 
radical  vinegar  of  the  apothecaries,  but  the 
method  is  now  obsolete.  It  owed  its  name 
to  its  pleasant  odour,  laigdy  due  to  acetone, 
which  IS  always  produced  when  acetates  of 
heavy  metab  are  distilled^  but  camphor  and 
essential  oils  were  frequently  added  to  increase 
or  modify  the  smell.  Commeroial  aromatic 
vinegar  is  now  made  by  adding  essential  oils 
and  spices  to  pure  diluted  acetic  add. 

Ocnceniratton  and  PurifiaUion. — ^The  acetic 
Aoid  obtained  by  the  distiUation  of  crude 
acetates  of  Ume  is  usuaUy  concentrated  by  the 
redistillation  of  united  similar  fractions  in  a 
oolunm  stiU,  whilst  organic  impurities  are 
oxidised  by  the  addition  of  potaadnm  per- 
manganate or  dichromate  prior  to  the  distillation. 

Accordii^  to  a  patent  process  of  the  Chem. 
Fabr.  Grieeheim-Elektron  (Ger.  Pat.  230171, 
1909)  anhydrous  copper  sulphate  ia  used  to 
dehvdrate  the  acid  during  the  distiUation ; 
whilst  meta-phosphoric  acid  is  used  for  the 
same  purpose   in  another  patent   (Ger.   Pat. 


282263,  1914).  GaUtzenstein  (A.  angew.  Chem. 
1916,  29,  148)  has  described  a  patent  process  of 
obtaining  glacial  acetic  acid  from  duute  acid 
by  extraction  with  an  immisdble  solvent,  such 
as  dichloroethylene,  and  claims  that  90  p.c.  of 
the  theoretical  yield  may  thus  be  obtained. 

In  anotherjprooess  (Harbuiger  Chem.  Werke 
Schdn  u.  Co.,  Ger.  Pat.  292959, 1915)  the  dUute 
acid  is  treated  with  potasdum  acetate,  and  the 
resulting  double  compound  of  potasdum  acetate 
and  acetic  acid  wnich  separates  from  the 
solution  is  redistiUed. 

An  electrolytic  method  of  purification 
(French,  U.S.  Pat.  1104978,  1914)  is  based  on 
the  decompodtion  of  impurities  by  means  of 
an  dectric  current,  the  strength  of  which  ia 
regulated  to  prevent  material  decompodtion  of 
acetic  acid. 

Formic  acid  and  tarry  matters  may  be 
removed  bv  redistilling  the  crude  acid  wiUi  an 
equal  weight  of  70  p.c.  sulphuric  acid  at  about 
130°,  at  which  temperature  formic  acid  is 
destroyed,  whilst  acetic  acid  i^  not  appreciably 
attacked  (A.  Gorhan,  U.S.  Pat.  1210792,  1917). 

Properties. — ^The  stoongest  add  soUdifies  at 
16*6*"  (Bousfield  and  Lowry,  Chem.  Soc.  Ptoo, 
1911,  27,  187)  in  tabular  or  prismatic  glistening 
crystals.  The  glacial  add  may  be  cooled  to 
—  10°  without  soUdification,  even  when  agitated, 
but  on  the  addition  of  a  crystal  of  tiie  ludd  the 
whole  soUdifies  and  the  temperature  rises  to 
16-7°. 

The  speoifio  gravity  of  the  crystals  at  1574° 
is  1  -0607  (MenddtefF,  J.  1860,  7).  They  mdt  to  a 
mobUe  colourless  Uquid  of  sp.  gr.  1-0543  at  1674° 
(Petterson,  J.  pr.  Chem.  [2]  24,  301),  1-0496  at 
20°/4°  (Briihl),  1-05148  at  18°/4°,  and  1-04922 
at  20°/4''  (Bouafidd  and  Lowry,  2.c.),  which  boUs 
at  118-5°  at  760  mm.  (Perkhi),  118-1°  (corr.) 
(Thorpe  and  Rodger).  The  liquid  is  unin- 
flammable, but  the  vapour  bums  with  a  blue 
flame  producing  water  and  carbon  dioxide. . 

BoiUKQ-poiNT  OF  Glagial  Aoetio  Aoid  undeb 
VARIOUS  P&BSSUBBS  (Lamioft). 


Pressure. 

Boiling 
point. 

1 
Presanre. 

mm. 
560 
360 
160 

Boiling 
point. 

Pressure. 

BoUing 
point. 

1160 
960 
700 

132 
126 
119 

°0. 

109 
96 
73 

nun. 
60 
30 

48 
31 

When  passed  through  a  red-hot  tube  only 
a  small  portion  is  decomposed,  produdnff  carbon, 
acetone,  benzene,  fto.  The  strong  acid  Dlackena 
when  heated  with  concentrated  sulphuric  add, 
evolving  sulphurous  and  carbonic  anhydrides. 

Nitric  and  chromic  adds  have  no  action ;  for 
this  reason  acetic  add  is  frequentiv  uaed  as  a 
solvent  for  oi^anio  substances  sucn  as  hydro- 
oarbons,  which  are  to  be  subjected  to  the  action 
of  chromic  acid.  Chlorine  under  the  inflnenoa 
of  sunlight  replaces  a  portion  of  the  hydrogen^ 
and  pn^uoes  mono-,  du  and  trichloracetic  acids. 
Similarly,  bromine  produces  dibromacHie  acid. 

Commeroial  acetic  acid  contains  impurities 
which  react  with  bromine  and  chlorine  in  the 
dark,  whereas  pure  acetic  acid  is  not  attacked 


ACETANILIDE. 


16 


by  these  halogens  in  the  dark.  These  impurities 
can  be  removed  by  distilline  the  acid  over 
phosphoric  oxide,  only  traces  ofacetio  anhydride 
being  formed  in  the  process  (Orton,  Edward,  and 
Ku^,  Ghenu  Soo.  Proc.  1911,  27,  120). 

Fore  acetic  acid  is  not  decomposed  by  direct 
sunlight,  which,  however,  effects  the  decomposi- 
tion of  acetaldehyde,  with  the  liberation  of 
methane  and  carbon  monoxide.  Direct  rays 
from  a  menmry  vapour  lamp  decompose  both 
acetaldehyde  and  acetio  acid,  the  latt^  yielding 
carbon  monoxide  and  dioxide  and  39  p.c.  m 
combustible  gases  (Berthelot  and  Gaudechon, 
Compt.  rend.  1913,  156,  68). 

On  the  addition  of  water  to  the  glacial  acid 
heat  is  evolved  and  the  density  increases  until 
20  p.o.  of  water  is  present ;  from  this  strength  to 
23  p.o.  of  water  the  density  remains  stationary. 
Further  dilution  lowers  the  density,  so  that 


either  dilution  or  concentration  from  this  point 
will  produce  an  acid  of  diminished  density. 
An  acid  containing  only  43  p.o.  of  acid  has  the 
same  density  as  the  glacial  aoid«  This,  together 
with  the  slight  difiFerence  between  the  density  of 
acetic  add  and  water,  renders  it  impossible  to 
determine,  with  any  precision,  the  percentage  of 
acid  by  means  of  the  hydrometer. 

No  definite  hydrates  of  acetic  acid  ore  known 
(De  Coppet,  Ann.  Chim.  Phys.  [7]  16,  276; 
Colles,  Ghem.  Soc.  Trans.  1906,  1247),  although 
the  break  which  occurs  in  the  curve  of  the 
solidification  points  at  about  37  p.c.  of  water 
suggests  the  formation  of  a  hydrate 

GgH40,+2H,0 

The  following  table  shows  the  density  of 
aqueous  acetic  acid  at  16^  and  20**  (Oudemans, 
Jahresber.  Fortsch.  Ghem.  1886,  302)  :— 


DnrSITT  OF  AQUSOUS   ACKTIO  AoID   (OUDEMAIfS). 


FA 

Density 

p.c 

il 
D«wit7 

P.C. 

Denaltj 

itP 

20° 

1»» 

ao» 

1»» 

OOP 

0 

0*9992 

0-9983 

34 

10469 

10426 

68 

1-0726 

1-0679 

1 

10007 

0-9997 

36 

10470 

1-0437 

69 

1-0729 

1-0683 

2 

10022 

10012 

36 

10481 

1-0448 

70 

10733 

1-0686 

3 

10037 

10026 

37 

10492 

10468 

71 

1-0737 

i-ofto 

4 

10062 

10041 

38 

10602 

1-0468 

72 

1-0740 

1-0691 

5 

1-0067 

1-0056 

39 

10513 

1-0478 

73 

10742 

1-0693 

6 

1-0033 

1-0069 

40 

10523 

1-0488 

74 

10744 

1-0695 

7 

1-0098 

1-0084 

41 

10533 

1-0498 

75 

10746 

1-0697 

8 

10113 

1-0098 

42 

1-0643 

10607 

76 

10747 

1-0699 

9 

10127 

10112 

43 

1-0662 

1-0616 

77 

10748 

1-0700 

10 

10142 

1-0126 

44 

10662 

1-0625 

78 

10748 

1-0700 

11 

10167 

10140 

46 

10671 

1-0634 

79 

1-0748 

10700 

12 

10171 

10164 

46 

10680 

10543 

80 

10748 

1-0699 

13 

10186 

10168 

47 

1-0589 

1-0551 

81 

10747 

1-0698 

14 

1<0200 

1-0181 

48 

10598 

10559 

82 

10746 

10696 

16 

1-0214 

10195 

49 

10607 

1-0567 

83 

1-0744 

1-0694 

16 

10228 

10208 

60 

10615 

10575 

84 

10742 

10691 

17 

1-0242 

1-0222 

61 

10623 

10583 

85 

1-0739 

1-0688 

18 

1-0266 

1-0236 

62 

10631 

1-0690 

86 

1-0736 

1-0684 

19 

1-0270 

1-0248 

63 

1-0638 

1-0597 

87 

10731 

10679 

20 

1-0284 

1-0261 

64 

1-0646 

10604 

88 

10726 

10674 

21 

1-0298 

10274 

66 

10663 

1-0611 

89 

10720 

1-0668 

22 

10311 

1-0287 

66 

1-0660 

10618 

90 

10713 

10660 

23 

10324 

1-0299 

67 

1-0666 

1-0624 

91 

10706 

10652 

24 

10337 

10312 

68 

1-0673 

1-0630 

92 

1-0696 

10643 

25 

10360 

1-0324 

69 

1-0679 

1-0636 

93 

1-0686 

10632 

26 

10363 

10336 

60 

10685 

10642 

94 

10674 

10620 

27 

1-0375 

1-0348 

61 

10691 

1-0648 

95 

10660 

10606 

28 

1-0388 

10360 

62 

1-0697 

1-0663 

96 

10644 

10689 

29 

1-0400 

1-0372 

63 

1-0702 

10658 

97 

1-0625 

10670 

30 

1-0412 

1-0383 

64 

1-0707 

10663 

98 

10604 

10649 

31 

1-0424 

10394 

65 

1-0712 

10667 

99 

1-0580 

1-0525 

32 

1-0436 

1-0406 

66 

1-0717 

10671 

100 

10553 

1-0497 

33 

10447 

1-0416 

67 

1-0721 

1-0676 

The  addition  of  a  small  quantity  ox  water 
lowers  the  melting-point  of  the  glacial  acid 
considerably,  as  shown  by  the  tabk  at  top  of 
p  16 :   Dahms  (Ann.  Ghim.  Phys.  [7]  18,  141). 

The  tables  on  p.  16  of  the  solidification  points 
of  mixtures  of  acetio  acid  and  water  are  of  use 
in  determining  the  strength  of  acetic  acid. 


Acetic  acid  is  monobasic,  but  forms  bath  acid 
and  basic,  as  well  as  normal  salts.  It  dissolves 
certain  metallic  oxides,  as  those  of  lead  and 
copper,  forming  basic  acetates. 

The  action  of  acetic  acid  on  aluminium  is  a 
matter  of  technical  importance,  since  aluminium 
stills  are  in  use  for  distilling  the  acid.     Alumi- 


n  in  dianolved  by  boiling  90  p.o.  aoetto  add 

with  the  tormntion  of  tta  ineoluble  gelatinons 
buio  Boetate  A1(0*C0GH,),0H,  which  probably 
a  protective  coating  upon  the  snrfaoe  of 
urn  pl&nt.  With  the  dilation  of  tile 
acid  the  rate  of  the  Bolation  rapidly  increaaM, 
and  90  p.c.  aoetio  acid  disBolvea  abont  10  timea 
as  mnch  aJnmininin  in  a  given  time  aa  9S  p.o. 
acid,  whilst  dilute  acid  attaoks  the  metal  very 
rapidly.  Slight  variations  in  the  strength  often 
have  a  pronounced  influence  on  the  solvent 
action,  the  addition  of  0-06  p.o.  of  water  to  a 
corroaive  acid  being  anffident  in  some  oases  to 
arreet  the  action  (Seligman  ajid  Williams,  J. 
8oc.  Chem.  Ind.  1916,  X,  88). 

The  moat  suitable  metals  for  the  conitmo- 
tion  of  acetic  acid  plant  are  block  tJn  and  gon- 
metal  containing  a  sufficient  proportion  of  tin. 

Aoetio  aoid  boa  a  pongent  sour  tast«,  and 
when  strong  blistors  the  skm.  The  glacial  acid 
has  no  action  on  litmus,  jDot  on  addition  of 
water  becomes  powerfully  acid.  It  is  not 
affected  by  the  electiio  current,  probably  because 
a  bad  oondnotor,  but  when  a  little  aulpburie 
acid  ia  added  tJie  oncrent  deoompoaes  it,  pro- 
dacinf,  according  to  Renard  (Ann.  Chlm,  Pnys, 
[S]  16,  289),  carbon  dioxide,  carbon  monoxide 
and  oxygen.  Alkali  acetatea  when  electrolysed 
are  decompoeed  into  hydrogen  and  alkali 
hydroxide  which  appear  at  the  negative  pole, 
and  ethane  and  caA>bn  dioxide  at  the  poaitive 

Aoetio  aoid  mizea  with  alcohol  and  ether 
a  all  proportiona.  It  dissolves  resins,  gelatin, 
fibrin,  albumin,  essentiai  oils,  &a.  Phoaphoma 
and  sulphur  are  somewhat  soluble  in  the  warm 

Acetic  aoid  is  laigely  osed  in  the  preparation 
ot  the  acetatea  of  copper,  aluminium,  iron,  lead, 
&c. ;  aa  pyiolignoons  acid  in  calioo  printing, 
and  the  curing  of  herrings,  h^ma^  &o.  ;  m 
''      preparation    of    vamiahea    and    oolouring 

ttera  ;  in  the  laboratory  and  certain  iuduatriea 
as  a  solvent;  f or  domeatio  use ;  in  photography; 
and  in  medicine  as  a  local  irritant  and  to  allay 
fever,  and  in  the  form  of  smelling  salts. 

Analysit, — Commercial  glocud  add  should 
contain  not  leas  than  98-9  p.o.  of  absolute  acid. 
""  .„-....,,  j^  below 

.  _.  ..  _j. agitated 

with   1   volame  of  aoid,   no  turbidity  will  be 


produced  if  the  acid  contain  97  p,o.  or  upwards. 
Acid  of  99'JI  p.o.  produces  no  taA)idity  with  aoy 
pron^rtion  M  ttupentine  (Bardy,  Chem.  News, 


40,18). 

A  very  delicate  teat  for  the  preamoe  ot  water 
is  to  mix  the  add  with  an  equal  bulk  of  carbon 
diaulphide  in  a  dry  tutie,  and  warm  with  tiie 
hand  for  a  few  minutes ;  in  preaenoe  of  a  traoe 
of  water  the  liquid  becomee  turbid. 

The  commercial  acid  may  contain  sulphuric 
acid,  aulphat«fl,  sulphurous  acid,  hydrochlorio 
add,  chlorides,  nitratca.  araenio  (derived  from 
Bulphurio  add),  and  copper,  lead,  zino,  iron, 
and  tin  derived  from  the  vessels  used  in 
the  monufactore. 

The  pKaence  of  sulphuric  acid  or  sulphates 
ia  shown  by  the  production  of  a  white  precipi- 
tate with  barium  chloride.  To  the  filtered  solu- 
tion bromine  or  chlorine  water  is  added,  pro- 
ducing, if  sulphurous  aoid  be  present,  a  further 
I  precipitate   ol   barium  sulphate.     HydrocUoTM 


ACETIC  ACID. 


17 


aeid  and  chlorides  are  detected  and  estimated 
by  means  of  silver  nitrate. 

In  testing  for  metals  a  considerable  balk 
of  the  acid  should  be  eyaporated ;  a  few 
drops  of  hydrochloric  add  are  added,  and  a 
corrent  of  hydrogen  snlphide  passed  through 
the  liquid  ;  a  black  or  brown  colouration  or  pre- 
cipitate indicates  lead  or  copper.  Copper  may 
also  be  detected  in  the  evaporated  liquid  by  the 
brown  precipitate  produced  on  the  addition  of 
potassium  frarocyanide,  and  estimated  by  electro- 
deposition.  Iron  may  also  be  detected  by  the 
ferrocyanide  test.  To  test  for  zinc,  the  solution, 
after  the  passage  of  hydrogen  sulphide,  is 
filtered,  nearly  neutralised  with  ammonia,  and 
sodium  acetate  added,  when  zinc  will  be  pre- 
cipitated as  white  sulphide.  For  arsenic 
Reinsch's,  Marsh's,  or  the  electrolytio  test  may 
be  used. 

Small  quantities  of  acetic  acid  may  be  recog- 
nised by  neutralising  the  liquid  with  potassium 
hydroxide,  addins  arsenious  oxide,  evaporating 
to  dryness,  and  heating  the  residue,  wnen  the 
characteristic  smell  of  cacodyl  is  evolved. 

To  det^mine  the  free  acetic  acid  in  a  solu- 
tion it  is  usual  to  titrate  a  weighed  quantity  with 
sodium  hydroxide  solution  standardised  against 
acetic  acid  of  known  strength  or  hydrogen 
potassium  tartrate  (Stillwell  and  Gladding). 

As  indicator  litmus  may  be  used,  but  as  it  is 
rendered  blue  by  the  normal  sodium  acetate,  it 
is  preferable  to  use  phenol-phthalefn,  to  which 
that  substance  is  neutral ;  this  is  also  more 
sensitive,  and,  where  coloured,  the  liquid  may 
be  considerably  dilated  without  impairing  the 
delicacy  of  the  reaction. 

To  estimate  small  percentages  of  water  in 
acetic  acid,  the  solidifying-point  may  be  deter- 
mined and  the  percentage  lound  by  the  tables 
before  given. 

Commercial  glacial  acetic  acid  usually  con- 
tains formic  acid  in  proportions  of  about 
0*02  to  0*8  p.c.  Methods  of  separating  and 
estimating  formic,  acetic,  propionic,  and  butyric 
acid  in  a<unixtuie  are  given  in  Zeit.  anal.  Chem. 
1899,  38,  217.  For  the  estimation  of  formic 
acid,  Fincke  (Apoth.  Zeit.  1910,  727)  boils  the 
acid  under  a  reflux  condenser  with  sodium 
acetate  and  mercuric  chloride,  and  separates 
and  weighs  the  precipitated  caramel.  Another 
method  has  been  cased  upon  the  fact  that  formic 
acid  will  expel  acetic  acid  from  acetates.  The 
acid  is  neutralised  with  sodium  hydroxide, 
evaporated,  and  the  residue  dried  at  126°,  and 
weighed.  It  is  then  evaporated  with  formic 
acid  two  or  three  times,  and  the  residue  again 
dried  at  125°.  The  difference  between  the 
weights  corresponds  to  the  amount  of  acetic  acid 
expelled.  The  results  for  formic  acid  are  about 
0*02  p.c.  too  high,  and  those  for  the  acetic  aci^ 
too  low  (Heermann,  Chem.  Zeit.  1916,  39,  124). 
According  to  the  B.  P.  (1914)  test  the  absence 
of  formates  is  shown  by  the  acid  not  darkening 
immediately  when  treated  with  ammonia 
solution  and  heated  with  silver  nitrate  solution. 

Chapman  (Analyst,  1899,  24,  114)  describes 
a  method  for  the  estimation  of  isovaleric  acid 
in  acetic  add. 

The  presence  of  acetic  anhydride  may  be 
ascertained  by  the  red  precipitate  of  amorphous 
selenium  obtained  on  treating  the  acid  with 
selenious  oxide  or  sodium  selenite.  pure  glacial 

Vol  I^— r. 


acetic  acid  remainini;  clear  in  this  test  (Klein, 
J.  Ind.  £ng.  Chem.  1910,  2,  389).  Another 
sensitive  test  is  based  upon  the  fact  that  acetic 
anhydride  reacts  with  certain  aniline  derivatives, 
notably  2  :  4-dichloro-aniline,  to  form  insoluble 
anilides,  which  can  be  separated  and  indireotiy 
estimated  as  chloroamine  (Edwards  and  Orton, 
Chem.  Soo.  Proc.  1911,  27,  121). 

Aceto-acetic  acid  may  be  detected  by  the 
violet  colouration  which  it  gives  with  sodium 
nitroprusside  and  ammonia,  followed  by  insuffi- 
cient acid  to  neutralise  all  the  ammonia  (Harding 
and  Ruttan,  Biochem.  J.  1912,  6,  446). 

■The  acetic  acid  in  acetates  may  be  esti- 
mated by  distilling  about  1  gram  of  the  salt 
nearly  to  dryness  with  10  c.c.  of  a  40  p.c.  solu- 
tion of  pho^horic  acid  (free  from  mtrio  and 
other  volatile  acids) ;  water  is  added  and  the 
distillation  repeated  to  remove  the  last  traces  of 
acetic  acid ;  the  distillates  are  mixed  and  titrated 
as  above  with  standard  alkali.  This  method  of 
distillation  may  also  be  used  for  highly  coloured 
solutions  of  acetic  acid  where  direct  titration  is 
not  practicable ;  or  the  method  of  distillation 
with  formic  acid,  described  above,  may  be 
employed. 

Most  commercial  acetic  acid  contains  traces 
of  tarry  substances,  though  the  proportion  is 
much  less  in  acids  which  have  been  purified  by 
treatment  with  permanganate.  The  permissible 
'limit  for  such  empyreumatio  substances  in 
glacial  acetic  acid  is  prescribed  by  a  B.  P.  (1914) 
test,  according  to  which  2  c.c.  of  the  acid  should 
not  decolorise  within  half  a  minute  a  mixture  of 
3  drops  of  a  1  p.c.  solution  of  poljassium  per- 
manganate and  10  C.C.  of  water. 

MANUTAGTmS  OF  VlNEOAR. 

The  term  '  vinegar,*  as  its  derivation  implies, 
was  originally  applied  to  wine  which  had  become 
sour,  but  is  now  used  to  describe  all  products 
made  by  the  acetic  fermentation  of  alcoholic 
liquids,  the  particular  kind  of  vinegar  being 
usually  indicated  by  a  prefix,  such  as  *  wine 
vinegar,'   *  malt    vinegar,    *  cider  vinegar,*   or 

*  spirit  vinegar.*  The  terms  'beer  vinegar* 
and  '  alegar,  which  are  to  be  found  in  the  Acts 
of  Parliament,  are  now  obsolete. 

From  whatever  material  vinegar  is  derived 
the  essentials  of  the  process  are  the  same.  An 
alcoholic  liquid  of  a  suitable  strength  must  be 
subjected  to  the  oxidising  action  of  acetic 
bacteria,  in  the  presence  of  suitable  nutrient 
substances,  and  of  a  regulated  supply  of  air. 

Wine  vinegar.  (Fr.  Vinaigre ;  Ger.  Weijiesaig,) 
In  the  wine  district  of  Orleans,  which  has  been 
celebrated  for  centuries  for  the  production  of 
wine  vinegar  of  fine  aroma  and  flavour,  the 
original  method  was  to  add  a  little  vinegar  to 
sour  wine,  and  to  expose  the  mixture  to  the 
air  in  open  casks.  This  primitive  method  was 
still  in  use  as  late  as  1876,  although  most  vinegar 
makers  in  France  had  long  discarded  it  for  the 

*  Orleans  process,*  in  which  the  wine  is  acetified 
in  a  series  of  casks  packed  with  shavings  and 
provided  with  holes  for  the  admission  of  air. 

Full-bodied  wines  are  selected  for  the  manu- 
facture, and  if  they  contain  above  10  p.c.  alcohol 
they  are  suitably  diluted  with  weaker  wines. 
The  wine,  before  being  fermented,  is  usually  left 
for  some  time  in  contact  with  beech  shavings, 

o 


Ig 


ACBTTO  AOTB. 


on  wUoh  the  lees  are  deposited,  rendering  the 
wine  brighter.  A  certain  amoiint  of  extrwotive 
matter  is,  however,  necessary  for  the  develop- 
ment of  the  bacteria,  and  if  the  wine  be  old  and 
the  matter  deposited,  the  fermentation  is  much 
retarded.    Wme  one  year  old  is  preferred. 

The  '  Vinaigreiie  *  is  nsuaUy  a  building  of 
southern  aspect;  the  rooms  in  which  the  pro- 
cess is  conducted  are  low-roofed,  and,  in  order 
to  admit  air,^the  walls  are  provided  with  open- 
ings which  can  be  dosed  when  the  temperature 
is  not  sufficiently  hish. 

Sets  of  casks  of  well-seasoned  oak,  bound 
with  iron  hoops,  each  holding  from  60  to  100 
gallons  are  supported  on  their  sides  in  rows 
about  18  inches  from  the  floor,  one  set  being 
frequently  placed  above  another,  in  which  case 
those  nearest  the  roof  are  found  to  work  most 
rapidly.  Each  cask  is  bored  with  two  holes  in 
the  front  end,  a  lareer  one,  the  '  eye,'  for  the 
addition  of  wine  or  die  removal  of  vinegar,  and 
a  small  one  for  the  admission  of  air. 

When  first  used  the  casks  are  thoroughly 
scalded  with  boiling  water  to  remove  extractive 
matter,  filled  to  a  third  of  their  capacity  with 
boiling  strong  vinegar,  and  allowed  to  stand  for 
eight  days;  from  that  time  wine  is  added  in 
charges  of  about  10  pints  every  eight  days  until 
the  casks  are  not  more  than  two-thirds  full; 
after  a  further  interval  of  14  days  a  portion, 
vaiying  from  10  gallons  to  half  the  total  bulk, 
18  drawn  of!  and  the  periodical  addition  of  the 
wine  continued.  The  temperature  of  the 
chambers  should  be  about  2^,  and  is  kept  up 
when  necessary  with  a  stove.  In  order  to 
a -certain  if  the  fermentation  is  completed  at 
the  end  of  the  usual  time,  the  workman  plunges 
a  white  spatula  into  the  licjuid ;  if  a  reddish 
froth  adheres,  more  wine  is  added  and  the 
temperature  raised;  a  white  froth  indicates 
the  completion  of  the  process.  More  than  eight 
days  are  sometimes  required  to  complete  the 
oxidation,  in  which  case  stronger  wine  and  a 
higher  temperature  may  be  used.  The  sluggish- 
ness may,  however,  be  due  to  the  casks  becoming 
foul,  which  occurs  usually  after  about  six  years^ 
working.  The  deposit  of  aigol,  yeast  sediment, 
&c.,  is  thoroughly  remov^,  and  the  casks 
cleansed  and  recharsed  with  hot  vinegar  as  in 
the  case  of  new  caucs.  Good  casks  will  often 
last  twenty-five  years. 

When  working  satisfactorily  each  cask  will 
produce  about  twice  its  capacity  of  vinegar 
annually. 

Refore  storing,  the  vinegar  is  usually  passed 
throuffh  the  *  rapes  *  where  it  is  '  brightened  * 
and  the  acctiBcation  completed. 

The  drawback  of  the  Orleans  process  is  that 
it  is  excessively  slow,  but,  on  the  other  hand, 
the  slow  working  promotes  the  formation  of  the 
esters  to  which  French  wine  vinegar  owes  its 
reputation. 

In  other  parts  of  France  and  in  Holland  and 
on  the  Rhine  the  followins  method  is  used. 
The  wine  is  placed  in  two  laige  upright  tuns 
about  0  feet  high  and  4  feet  wide,  open  to  the 
air.  Each  tun  has  a  perforated  false  bottom 
about  12  inches  above  tne  true  bottom  ;  on  this 
is  placed  a  quantity  of  vine  cuttings,  stalks, 
^c,  Ro  as  to  expose  a  large  surface  for  the  forma - 
tiun  of  <he  fungus.  One  of  the  vat8  is  half,  and 
the  other  completely,  filled.     The  acetification 


progresses  more  rapidly  in  the  former;  this, 
after  twenty-four  hours,  is  filled  from  the  fuU 
cask,  in  which  the  action  then  increases.  This 
alternate  transference  is  continued  daily  until 
the  acetification  is  complete.  The  most  favour- 
able temperature  is  about  24°.  The  vinegar  is 
run  off  into  casks  containing  chips  of  birch  wood 
on  which  the  lees  settle,  and  in  about  fourteen 
days  being  thus  clarified  is  stored  in  close  casks 
for  the  market. 

This  method  is  described  in  a  letter  published 
by  the  Royal  Society  in  1670  (Phil.  Trans.  Roy. 
Soo.  1670,  V.  2002). 

In  CIaudon*s  process  of  acetification  the 
wine  is  fermented  in  a  series  of  superposed 
closed  shallow  vessels,  so  constructed  that  air 
currents  can  be  conducted  over  the  surface  of 
thin  layers  of  the  wine.  This  is  more  rapid 
than  the  ordinary  Orleans  process. 

Malt  vinegar  (Mahgetreide  Bieressig).  The 
vinegar  industry  in  this  country  has  developed 
out  of  the  brewing  industry,  and  the  connection 
between  the  two  industries  is  clearly  shown  in 
the  Revenue  Act  of  Charles  II.  (1673),  in  which 
the  so-called  '  vin^ar  beer  *  produced  in  the 
'  common  breweries '  was  changed  a  duty  of 
6d,  per  barrel  as  against  1^.  Sd,  upon  six-billing 
beer.  It  is  very  probable  that  most  of  tJie 
vinegar  first  made  in  England  was  a  product 
of  the  brewery  which  had  become  aociaentally 
sour,  and  was  then  exposed  to  the  air  to  com- 
plete the  acetification.  The  manufacture  of 
vinegar  as  a  separate  industry  appears  to  date 
back  not  much  further  than  the  early  part  of 
the  seventeenth  centuiy,  and  the  first  *  vinegar 
yard  *  in  London  was  established  about  the  year 
1641.  But  long  before  any  vinegar  brewer 
had  become  established  in  this  country  '  beer 
vinegar  *  or  *  alegar  *  was  made  in  many  a  house- 
hold by  the  simple  process  of  adding  the  so- 
called  *  vin^ar  plant  *  (t.6.  the  zoogloeal  form 
of  acetic  bacteria)  to  ale  which  had  turned  sour. 

The  process  of  making  vinegar  on  a  manu- 
facturing scale  was  proMbly  mtroduced  into 
this  country  from  France,  and  the  methods 
which  had  been  found  to  give  the  best  results 
in  the  production  of  wine  vin^ar  were  adapted 
to  the  acetification  of  the  Ensfish  product  from 
beer  or  ale.  The  methods  of  brewing  used  by 
the  brewer  and  the  vin^ar  maker  then  began  to 
diverge,  and  the  differences  are  now  well  marked, 
being  based  upon  the  different  qualities  desired 
in  the  alcoholic  product. 

Preparation  of  the  Wort, — ^In  preparing  the 
fermented  alcoholic  liquid  from  msM,  or  malt 
and  grain,  either  a  mash-tun  process  or  a  con- 
version process  is  employed.  The  mash-tun  is 
essentially  the  same  as  the  brewer^s  mash -tun, 
with  the  exception  that  it  has  both  rakes  and 

rrge  and  is  provided  with  a  steam  coil  below 
perforated  false  bottom. 
The  chief  aim  of  the  vinegar  maker  is  to 
obtain  as  high  a  yield  of  alcohol  as  possible, 
and  he  therefore  uses  a  malt  of  fainy  high 
diastatic  capacity,  and  makes  the  mash  at 
such  temperatures  as  will  yield  a  wort  which 
will  attenuate  well.  In  some  works  tiie  first 
mash  is  made  with  water  at  about  65°,  which 
gives  a  temperature  of  a  little  over  60°  in  the 
mash  tun.  After  raking  for  an  hour  or  two,  tii<^ 
wort  is  drawn  off,  and  a  second  mash  made  at 
the  same  temperature,  and  finally  the  *  goods' 


ACETIC  ACID. 


19 


•re  spai^ged  with  water  at  about  65^-71®.  In 
other  Yinegar  breweries  the  initial  mash  is  made 
with  water  at  about  54*^,  and  the  temperatare 
gradoally  raised  to  65**.  A  second  mash  is 
made  at  about  65^,  and  the  final  sparging  at 
W*-1V.  This  method  ensures  a  better  yield 
of  a  more  fermentable  wort.  It  is  a  common 
practice  to  use  raw  grain,  such  as  barley,  flaked 
maize,  or  flaked  rice  in  admixture  with  the  malt, 
the  diastase  of  the  latter  being  sufficient  to 
hydrolyse  the  whole  of  the  starch  present. 

If  crude  rice  be  used  a  preliminary  treatment, 
such  as  cooking  with  steiam  under  pressure,  is 
necessary  to  rupture  the  starch  granules. 

In  other  Tmegar  worki  the  starch  of  the 
cereals  used  is  hydrolysed  by  a  dilute  mineral 
add  instead  61  by  the  duastase  of  malt.  For  this 
purpose  the  grain,  usually  maize  or  rice,  is 
mixed  with  duute  (about  3  p.c.)  sulphuric  acid 
in  a  closed  iron  voosol  and  heated  for  several 
hours  bn^  steam  under  pressure,  until  a  sample 
of  the  nquid  is  free  from  unconverted  starch. 
The  contents  of  the  converter,  which  now  con- 
sist larj^ely  of  an  acid  solution  of  dextrose,  are 
neutralist  with  lime  and  chalk,  and  then  drawn 
off,  cooled,  and  fermented  in  the  same  way  as 
the  wort  from  the  mash  tun. 

From  6  to  7  tons  of  ^in  can  be  treated 
in  a  converter  of  averace  size,  and  the  whole  of 
the  stareh  present  wm  be  hydrolysed  within 
3  hours  when  heated  with  steam  under  a  pressure 
of  about  10  lbs. 

AHhouffh  most  of  the  calcium  sulphate 
separates  nom  the  Uauid,  sufficient  will  remain 
in  solution  to  afford  an  indication  that  the 
vinegar  was  probably  prepared  by  a  conversion 


Fermeniation  of  the  Wort. — ^The  wort  obtained 
by  one  of  the  above  described  processes  is  cooled 
in  a  refrigerator,  and  pitched  with  yeast  as  in 
a  brewery,  with  liie  difference  that  a  much  higher 
temperature  is  permissible  than  in  the  case  of 
beer.  In  fact,  with  some  yeasts  it  is  advisabb 
to  have  a  temperature  as  high  as  21^-24°  to 
check  the  growth  and  obtain  better  attenua- 
tion. If  malt*  with  good  diastatic  power  has 
been  used,  and  the  wort  has  been  prepared 
at  a  low  temperature,  there  is  usually  no 
difficulty  in  attenuating  a  wort  from  a  sp.gr. 
of  I'OSS  to  about  1*001.  In  certain  cases 
vigorous  aeration  of  the  fermenting  wort  is  also 
required  to  effect  this  purpose.  After  fermenta- 
tion, which  will  be  complete  on  the  third  day, 
the  gyie  or  wuh,  as  it  is  now  termed,  is  allowed 
to  stand  for  a  few  days  for  the  yeast  to  subside, 
and  is  then  pumped  into  store  vats  until  required 
for  the  further  fermentation  process. 

Aceiifieation  of  the  Oyle. — ^The  secondary  or 
acetic  fermentation  of  the  alcoholic  liquid  is 
effected  by  the  action  of  one  of  the  species  of 
acetic  bacteria,  mentioned  above,  which  under 
regulated  conditions  of  temperature  and  aeration 
oxidise  the  alcohol  first  to  aldehyde  and  then  to 
acetic  acid,  the  relative  proportions  of  the  three 
substances  niesent  in  the  liquid  at  any  given 
stage  Off  the  process  depending  laigely  upon 
the  conditions  of  the  fermentation.  In  addi- 
tion to  aldehyde  and  acetic  acid,  acetal 
CH,-CH(OC,Hs),  is  also  formed  through  the 
interaction  of  the  aldehyde  with  the  alcohol, 
and  traces  of  ethyl  acetate  and  other  esters, 
suocinio  aeid   and  other  acids,  are   prodaced. 


their  nature  and  quantity  depending  upon  the 
nature  of  the  substances  (sugars,  dextrins,  &c.) 
in  the  gyle.  Brown  (J.  Chem.  8oc.  1886,  49, 
172)  showed  that  B.  zylinua  (*  the  vinegar 
plant ')  had  the  power  of  transforming  Isevulose 
mto  cellulose. 

Theoretically  46  parts  of  alcohol  should  yield 
60  parts  of  acetic  acid,  but  in  practice  there  is 
always  a  loss  of  at  least  10  p.c.,  and  in  many 
factories  very  much  more.  This  loss  is  due 
partly  to  volatilisation  of  aldehyde  and  enters, 
and  partly  to  the  fact  that  acetic  bacteria  are 
able  to  decompose  the  acetic  acid  which  they 
have  produced,  and  if  the  aeration  of  an  acetifier 
is  irr^ular  the  production  and  decomposition 
of  acia  may  proceed  simultaneously  in  oifferent 
parts  of  the  apparatus. 

Should  insufficient  air  be  suppUed  to  an 
acetifier,  the  bacteria  (in  this  country  usually 
Brown's  B,  xylinus)  form  themselves  into  the 
zoogloeal  condition,  which  is  a  tough  gelatinous 
pdlicle  which  sooner  or  later  chokes  the  aceti- 
fying medium  and  arrests  the  process.  On  the 
other  hand,  excess  of  air  promotes  loss  by 
volatilisation  and  oxidation.  The  second  essen- 
tial is  a  suitable  temperature  for  the  action  of 
the  bacteria.  On  the  Continent  the  acetifiers 
work  best  at  a  temperature  of  about  85^  to  90°  F., 
whereas  in  England  the  optimum  temperature 
is  108°  to  110°  F.,  which  may  be  partly  due  to 
acclimatisation  of  the  bacteria.  Sunlight  checks 
the  acetification  process,  and  hence  tlie  early 
vinegar  makers  took  pains  to  exclude  all  dayUght 
from  their  apparatus,  but  under  the  present 
conditions  of  working  this  is  unnecessary,  for 
the  amount  of  light  which  can  find  its  way 
through  the  aeration  holes  of  the  large  acetifiers 
now  in  use  is  practically  negligible. 

The  methods  of  acetification  first  used  in 
this  country  were  essentially  the  same  as  those 
used  in  the  earlier  methods  of  making  wine 
vinegar  {vide  supra),  the  casks  being  placed  on 
their  sides  in  a  room  at  about  24°,  or  placed  in 
rows  in  a  'vinegar  field.'  The  bung  holes  of 
the  casks  were  left  open ;  at  each  end  near  the 
top  holes  were  left  for  the  circulation  of  the 
air.  Each  day  a  portion  of  the  liquid  was 
removed  from  a  full  cask  and  replaced  by  an 
equal  quantity  of  liquid  in  a  more  advanced 
stage  of  fermentation,  until,  after  about  three 
months,  the  process  was  complete.  This 
method  of  acetification,  which  was  known  as 

*  fieldins,'  has  been  obsolete  for  many  years. 

Qulek  vinegar  process  {SchndUasi^ereitung). 
The  introduction  of  the  so-called  '  quick  '  pro- 
cess of  making  vinegar  is  attributed  to  Schiitzen- 
bach,  although  in  its  main  essentials  it  is  only  a 
development  of  the  method  of  acetification  used 
in  certain  wine-vinegar  factories  in  France  in 
1670  {vide  supra).  The  main  features  intro- 
duced by  Schiitzenbach  were  the  use  of  a  larger 
vessel,  and  of  mechanical  means  for  the  repeated 
distribution  of  the  gyle  over  the  acetifying 
medium. 

The  acetifiers  introduced  into  British  vinegar 
workH  about  sixty  years  ago,  at  the  time  when 

*  stoves,'  as  the  acetifying  rooms  were  called,  re- 
placed the  vinegar  fields,  were  large  vats  taking  a 
charge  of  about  3000  gallons.  About  two-thirds 
of  the  way  up  was  a  perforated  false  bottom 
upon  which  beech  shavings  or  twigs  were  looselv 
packed,  and  upon  these  the  bacteria  developed. 


20 


ACETIC  ACID. 


whib  air  currents  were  admitted  through  a 
number  of  holes  bored  in  the  side  of  the  vat 
just  below  the  false  bottom,  and  escaped  through 
small  holes  in  the  top  of  the  vat. 

The  gyle  was  distributed  in  a  fine  shower 
over  the  shavings,  by  means  of  a  revolving 
spaige.  and  trickling  downwards  encountered 
tne  currents  of  air,  which  enabled  the  bacteria 
to  acetify  a  small  amount  of  the  alcohol.  The 
liquid  from  the  bottom  of  the  vat  was  then 
pumped  up  again,  to  be  once  more  distributed 
over  the  shavings,  and  so  on  continually  for 
two  or  three  weeks  until  nearly  the  whole  of 
the  alcohol  had  been  transformed  into  acetic 
acid.  The  drawback  of  shavings  as  a  medium 
was  that  they  soon  became  clogged  with  mother- 
of-vinegar  in  places,  so  that  the  air  was  no 
longer  evenly  distributed  throughout  the 
medium,  but  made  channels  in  various  places. 

For  this  reason,  in  many  factories  shavings 
were  replaoed  by  basket  work  in  superposed 
layers,  and  these  worked  much  more  regularly, 
and  could  be  more  easily  cleaned.  In  other 
works  porous  lumps  of  charcoal,  which  had  been 
washed,  first  witn  acid  and  then  with  water, 
were  used  as  the  acetifying  medium,  and  pro- 
moted the  acetification  by  the  absorption  of 
oxygen. 

In  Wagenmann*s  'graduator,*  which  was 
devised  about  1830,  a  perforated  shelf  was  fixed 
about  6  inches  from  the  top  of  the  vat,  and 
through  each  of  the  400  holes  cotton  or  hemp 
wick  was  suspended  to  guide  the  liquid  down- 
wards on  to  tne  shavings. 

In  this  apparatus  was  foreshadowed  the 
idea  utilised  m  Luck's  acetifier,  in  which  the 
shavings  were  replaced  by  bunches  of  cords 
stretched  between  the  distributing  tray  and  the 
false  bottom.  This  type  of  acetifier  works 
regularly  and  is  easily  cleaned. 

Another  type  of  acetifier,  patented  by 
Leaker,  is  made  up  of  a  series  of  rectangular 
compartments  containing  shelves  of  absorbent 
woven  material  which  act  as  the  acetifying 
medium,  whilst  a  fan  is  employed  to  draw  the 
evaporated  products  into  a  condensing  coil. 

in  Singer's  acetifier  several  rectangular 
compartments  are  superposed,  and  each  of  them 
contains  a  series  of  wooden  tubes  packed  with 
shavings  or  charcoal,  and  the  wash  is  acetified 
as  it  trickles  successively  through  these  tubes 
from  the  top  to  the  bottom  of  the  apparatus. 

Berseh*s  apparatus  is  also  rectangular  in 
form,  and  is  packed  with  a  series  of  frames 
filled  with  slats  of  wood  with  a  space  of  about 
i  inch  between  each  slat.  These  frames  are 
superposed,  with  the  slats  running  in  alternate 
dintctions,  and  the  wash  is  acetified  as  it  trickles 
down  through  the  successive  layers  of  frames. 
It  is  claimed  that  this  acetifier  gives  a  theoretical 
yield  of  acetic  acid,  owing  to  its  perfect  system 
of  aeration,  but  in  the  writer's  experience,  this  is 
not  the  case  under  English  methods  of  acetifica- 
tion, the  boBt  yield  obtained  being  0*96  p.c.  of 
acetic  acid  from  0*97  p.c.  of  alcohol  in  24  hours 
(J.  Inst.  Brewing,  1917,  23,  362). 

Other  modifications  of  the  acetifier  make 
use  of  a  siphon  within  a  tank  for  distributing 
the  wash  over  a  perforated  tray,  whilst  the  air 
required  in  the  siphon  tank  is  drawn  from  the 
space  at  the  top  of  the  acetifier,  so  that  the 
aeration  of  the  apparatus  remains  under  control. 


The  working  of  aoetifiem  is  liable  to  be  dis- 
turbed  by  the  development  of  vinegar  eels 
{LepUyfcra  oxophila),  although  these  cause  less 
trouble  in  this  country  wan  on  the  Con- 
tinent, where  acetification  is  effected  at  a  lower 
temperature.  Another  enemy  of  the  acetifica- 
tion process  is  the  *  vinegar  mite,'  which,  if 
allowra  to  develop,  will  eventually  stop  the 
process. 

The  use  of  pure  cultivations  of  specifio  aoetio 
bacteria  has  h^n  shown  to  increase  the  speed 
of  acetification  and  improve  the  flavour  of  the 
vinegar,  but  so  far  no  attempt  has  been  made 
to  make  use  of  them  in  this  country,  where  in- 
sufficient importance  is  attached  to  the  flavour  of 
vinegar  (Henneberg,  Zeit.  fur  Spiritusind.  1898, 
180,  and  Cent.  Bakt.  1905, 14, 681  ;  Rothenbach, 
Woch.  fiir  Brau.  15,  445,  and  Deut.  Essiggind. 
1905, 9,217,  and  Woch.  fur  Brau.  1906,  23,  260 ; 
Mayer,  Zeit.  fiir  Spiritusind.  21,  334 ;  Buchner 
and  Gaunt,  Annalen,  1906,  349,  140). 

The  Otoup  System. — ^Aoetic  bacteria  are 
sensitive  to  tne  action  both  of  alcohol  and  of 
acetic  acid,  being  killed  by  alcohol  of  10  p.c. 
strength,  and  weakened  by  alcohol  of  much 
lower  strength.  Their  greatest  vital  activity  is 
attained  mien  the  wash  reaches  an  acidity 
of  between  2  and  3  p.c.  of  acetic  acid,  and  their 
acetifying  power  becomes  less  as  the  proportion 
of  acid  rises.  It  is  possible,  however,  to  acclima- 
tise them  to  resist  the  action  of  more  alcohol 
and  acetic  acid  than  under  normal  conditions, 
and  on  this  fact  is  based  the  grmip  eystem  of 
acetification. 

Since  a  12  p.o.  vinegar  could  not  be  obtained 
directly  from  one  acetifier,  the  acetification  of 
such  concentrated  products  as  Essigsprit  {vide 
eupra)  is  efifected  in  three  groups  of  aoetifiers. 
The  first  group  is  chaiged  with  a  wash  which 
will  yield  a  vinegar  of  about  6  p.c.  strength,  and 
this  is  fortified  with  an  alcoholic  wash  (usually 
grain  or  potato  spirit)  in  sufficient  quantity  to 
yield  a  vinegar  containing  9  to  10  p.c.  of  acetic 
acid  in  the  second  group  of  acetifiers ;  and  the 
vinegar  from  these  is  again  fortified  before  being 
transferred  to  the  thira  group  ol  acetifiers  for 
the  completion  of  the  acetification. 

FiUraiion  and  Storage  of  Vinegar. — ^Ab  soon 
as  the  vinegar  has  reached  its  maximum  acidity 
it  is  at  once  pumped  into  store  vats,  for  it  is 
essential  that  it  should  not  be  left  in  the  acetifiers, 
where  the  bacteria  would  oxidise  the  acetic  acid 
(vide  twpra). 

In  some  works  the  vinegar  is  clarified  by  the 
addition  of  potassium  ferrocyanide.  It  has*  been 
shown  by  Harden  that  there  is  a  possibility 
of  hydrocyanic  acid  being  liberated  in  the 
presence  of  excess  of  the  precipitant  (L.  G.  B. 
Report  on  Vinegar,  1908,  p.  27). 

After  remaining  in  the  store  vats  for  as  long 
a  time  as  possible,  preferably  not  less  than  three 
months,  the  crude  vinegar  is  filtered.  The  filters 
used  in  most  vinegar  works  are  known  as  mpeji, 
owing  to  the  fact  that  raisin  stalks  were  at  one 
time — ^and  to  a  limited  extent  are  still — used  as 
part  of  the  filtering  medium.  Filter  bedR  com- 
posed of  layers  of  sand,  shingle,  and  beech  chips 
are  used  for  the  rapes  in  other  factories,  whilst 
in  others  again  the  rapes  have  been  entirely 
superseded  by  filters  containing  paper  pulp  as 
the  filtering  medium. 

Aft4*r  bpinp  filtered  the  *  bright '  vinegar  is 


ACETIC  ACID. 


21 


again  stored  to  develop  an  aroma  through  the 
oombination  of  avetio  acid  with  traces  of 
residual  alcohol,  and  is  then  diluted  to  the 
strength  required  by  the  trade. 

These  different  strengths,  technically  known 
as  *  trade  numbers/  are  termed  Nos.  16,  18,  20, 
22,  and  24.  It  is  sometimes  asserted  that  these 
numbers  denote  the  number  of- grains  of  sodium 
carbonate  neutralised  by  1  oz.  of  the  vinegar, 
but  both  the  tradition  of  the  industry  and  con- 
temporary evidence  show  that  they  indicated 
the  price  in  pence  per  gallon  at  which  the 
vin^rar  was  sold  (Penny  Magazine,  1842,  p.  430 ; 
Tomhnson's  Cyclopa:dia  of  Useful  Arts,  1854, 
p.  7 ;  J.  Soo.  Chem.  Ind.  1918.  148  R). 

The  trade  numbers  would  thus  originally  be 
analogous  to  the  term  '  six  ale,*  meaning  '  six- 
ihUline  ale.' 

Before  being  sent  out  to  the  trade  vin^ar 
is  frequcntiy  coloured  to  a  dark  idiade  by  the 
addition  of  caramel. 

Di€itUei  Vinegar. — In  the  early  method  of 
preparing  aromatic  or  radical  vineqar  {vide 
«iipm),  vinegar  was  distilled  in  a  retort  at 
the  ordinary  pressure,  but  in  the  modem  process 
the  distillation  is  effected  at  a  lower  temperature 
under  reduced  pressure,  and  can  thus  be  carried 
very  much  farther  without  risk  of  burning  the 
solid  residue,  and  flavouring  the  distillate. 

The  small  stills  commonly  used  for  this 
purpose  are  made  of  gunmetal  lined  with  tin, 
and  are  heated  by  a  steam  jacket.  The  outlet 
pipe  from  the  still  is  connected  with  a  tin  coil 
immersed  in  a  vessel  of  running  water,  and 
delivers  into  a  receiver  in  which  is  a  pipe  con- 
nected with  a  vacuum  pump.  The  stiU  takes 
a  charge  of  about  100  gallons,  which  is  distilled 
under  a  reduced  pressure  of  about  20  inches  until 
only  a  semi-solid  mass  resembling  treacle 
remains  in  the  still. 

The  distillate  is  sold  under  the  names  of 
di^iUed  malt  vinegar,  white  vinegar  and  (incor- 
rectly )  white  wine  vinegar. 

In  addition  to  wine  and  malt,  vinegar  is  pie- 
pared  from  many  other  substances.  Ciifer 
vinegar  is  of  a  yellowish  colour,  8p.gr.  1*013  to 
1*015.  It  contains  3|  to  6  p.c.  acetic  acid,  and 
on  evaporation  leaves  a  mucilaginous  residue, 
smelling  and  tasting  of  baked  apples,  and  con- 
taining malic  but  not  tartaric  acicl.  The  residue 
varies  from  1  '5  to  1*8  p.o.  Genuine  cider  vinegar 
is  distinguished  from  spurious  cider  vinegar  oy 
the  residue,  which  consists  of  glycerol,  albuminous 
matters,  gums,  malio  and  other  organic  acids 
and  mineral  matters.  They  have  no  rotation 
and  little  cupric  reducing  power  after  the  usual 
clarification  with  basic  lead  acetate  solution. 
Aoetylmethyi  carbinol  is  a  characteristio  con- 
stituent of  cider  vinegar.  The  ash  of  a  pure 
cider  vinegar  amounts  to  not  less  than  0*25  p.c, 
consisting  mainly  of  potassium  oxide,  with 
small  quantities  of  alumina,  lime,  magnesia, 
sulphate,  and  phosphate,  variable  amounts  of 
carbonate,  and  complete  absence  of  soda. 
Spurious  cider  vinegars  leave  a  molasses-like 
residue  and  an  ash  with  a  large  percentage 
of  lime  or  soda  (DoolitUe  and  Hess.  iSee 
also  Smith,  J.  Amer.  Chem.  Soo.  1898,  20,  3 ; 
Leach  and  Lythgoe,  Ic.  1904,  26,  375;  Van 
Slyke,  New  York  Agric.  Exp.  Stn.  Bull.  1904, 
258,  439;  Ladd,  N.  Dakota  Exp.  Stn.  BuU. 
32,  278).    Cider  vinegar  made   by  the  '  quick  ' 


process  contains  on  the  average  5*7  p.c.  of  acetic 
acid,  and  0*4  p.c.  of  alcohol.  The  total  solids, 
ash  and  glycerol  are  substantially  the  same  as 
in  the  cider  from  which  the  vin^ar  was  pre- 
pared (Tolman  and  Gk)odnow,  J.  Ind.  Eng.  Chem. 
1913,  5,  928).  Perry  and  crab -apple  vinegar  are 
used  in  Wales  and  Monmouthshire,  and  possess 
characteristic  properties. 

Olucaee  or  sugar  vinegar  is  prepared  by 
the  conversion  of  amylaceous  substances  into 
sugar,  by  the  action  of  dilute  acids,  followed  by 
fermentation  and  acetiJScation.  It  contains 
dextrose,  dextrin,  and  very  often  gypsum,  with 
hardly  any  proteins.  The  ash  is  composed 
mainly  of  potassium  salts,  is  rich  in  sulphates, 
and  in  the  case  of  cane-sugar  vinegars,  readily 
fusible  (Allen's  Ck>mm.  Org.  Anal.  1909,  498). 
It  is  stated  to  be  used  for  adulterating  wine 
vinegar.  It  can  be  distinguished  from  other 
vinegars  by  the  addition  of  3  or  4  volumes  strong 
alcohol,  wnich  produces  a  sUmy  precipitate  of 
dextrin.  Barium  chloride  usually  gives  a  copious 
precipitate,  due  to  the  sulphuric  acid  used  in  the 
manufacture  of  the  glucose. 

Vinegar  is  now  made  from  skim  milk  by 
addition  of  suear,  neutralisation  with  chalk, 
pitching  first  wiSi  yeast  and  then  with  Mycoderma 
aceti  (Barbier,  Fr.  Pat.  334071,  1903). 

Dale  vinegar  is  made  by  the  consecutive 
alcoholic  and  acetic  fermentations.  Compared 
with  malt  vinegar,  it  is  low  in  phosphoric  acid 
and  nitrogen. 

Wood  *  vinegar,^  as  its  name  indicates,  is 
nothing  more  than  dilute  acetic  acid  coloured 
with  caramel,  and  sometimes  flavoured  with 
brewed  vinegar  or  with  acetic  ester.  It  con- 
tains about  0*2  to  0*6  p.c.  of  totel  solids,  0*02  to 
0  04  p.c.  of  ash,  and  traces  of  phosphoric  acid 
and  nitrogen. 

Properties. — Malt  vinegar  is  a  brown  liquid 
of  a  characteristic  odour  duo  to  the  presence,  in 
addition  to  the  acetic  acid,  of  acetic  and  other 
esters.  Acetic  ester  is  sometimes  added  in 
small  quantity  to  increase  this  aroma. 

The  addition  of  1  part  sulphuric  acid  to 
1000  parte  vinegar  was  permitted  by  an  Excise 
Act  of  George  III.  of  1818,  but  this  Act  has  long 
been  repealed.  Such  addition  is  quite  un- 
necessary, and  is  probably  never  made  at  the 
present  time. 

Malt  vinegar  usually  conteins  alcohol,  dextrin, 
sugar,  and  extractive  matter,  acetates,  chlorides, 
and  sulphates,  and  on  evaporation  and  ignition 
leaves  a  residue  conteinin^  much  phosphate. 

Analysis  of  typical  vmegars  sold  as  *  malt 
vinegar    are  given  in  the  teble  at  top  of  p.  22. 

Of  these  samples  Nos.  I.  and  II.  show  the 
normal  figures  for  barley  malt  vinegar.  No. 
III.  was  said  to  contain  products  of  cereals  other 
than  barley,  whilst  No.  IV.  was  made  from  a 
mixture  of  rice  and  green  malt,  the  former  being 
responsible  for  the  low  phosphoric  acid,  and  the 
latter  for  the  high  nitrogen.  No.  V.  conteins 
abnormally  low  solid  matter,  and  No.  VI.  was 
made  by  the  conversion  process. 

Wine  vinegar  varies  in  colour  from  pale 
yellow  to  red ;  that  made  from  white  wine  is 
most  esteemed ;  it  usually  has  an  alcoholic 
odour.  Its  sp.gr.  is  1*014  to  1*015  ;  it  contains 
from  6  to  12  p.c.  acetic  acid.  A  litre  (1*76  pint) 
of  Orleans  vinegar  usually  saturates  6  or  7 
grams  (92  to  108  grains)  of  pure  dry  sodium 


AGETIO  ACID. 


Vo. 

Sp.gr.  aX 
156*. 

AceUc 
Add. 

Total 
soUda. 

Ath. 

P,0,. 

Nitrogen. 

PfOcOn 

orlgfoal 

soUdi. 

mtrogen 

on  original 

■olids. 

L 

1017  5 

p.e. 
5-4 

p.c. 
2-74 

p.c. 
0-49 

p.c. 
007 

p.c. 
007 

p.e. 
0-69 

p.c. 
0:64 

n. 

1021 

6-4 

3-84 

0-39 

013 

014 

1-08 

1-23 

III. 

1014-5 

51 

1*68 

016 

003 

003 

0-32 

0-28 

IV. 

1021 

5-9 

3-67 

0-34 

004 

014 

0-34 

111 

V. 

1013 

4-5 

1-76 

0-24 

009 

0-08 

1-00 

090 

VI. 

1014 

4-3 

2  04 

0-47 

007 

006 

0-83 

0-70 

carbonate.  On  evaporation  the  total  extract 
▼arieB  from  1*7  to  2*4  p.o.,  of  which  0'25  p.c.  is 
usually  potaesiam  tartrate,  a  salt  peculiar  to 
wine  vinegar.  The  residue,  with  the  exception 
of  the  tartar,  should  dissolve  in  alcohol. 

The  proof  vin^ars  of  varioos  countries  differ 
considerably;  the  minimum  of  acetic  acid 
allowed  by  the  various  Pharmacopoeias  is — 
Fiance,  8  to  9  p.c. ;  Germany  and  Austria, 
6  p.c. ;  Belgium,  6*6  p.a  ;  Russia,  5  p.c. ;  United 
States,  4*6  p.c.  Vinegar  is  no  longer  official  in 
the  British  Pharmaoopceia.  The  bulk  of  the 
vinegar  sold  in  this  country  is  of  a  strength  just 
over  4  p.c.  A  standard  was  fixed  oy  the 
Society  ot  Public  Analysts  in  1876  of  a  minimum 
of  3  p.c,  and  this  beinfi;  accepted  by  the  trade, 
became  in  practice  the  legal  ^standara.  In  1912 
the  Local  Government  Board  recommended  the 
adoption  of  a  4  p.a  standard,  but  no  statutory 
foroe  has  been  given  to  this  recommendation. 

Analysis  of  Vinegar. 

AcidUy. — ^This  is  usually  estimated  by  titra- 
tion with  standard  alkaU,  with  phenolphthalein 
as  indicator.  In  the  case  of  dark  samples 
caramel  may  be  precipitated  by  mecms  of 
fuller*s  earth  and  an  aliquot  part  of  the  filtrate 
titrated.  '  Spotting  *  tests  with  litmus  as 
indicator  give  resulte  about  1  p.c.  lower  in  terms 
of  N/2  alkali  solution  than  direct  titration  with 
phenolphthalein  as  indicator  (Brode  and  Lange, 
Arb.  Kaiserl.  Gesundheitsamte,  1909,  30,  1). 

ToUd  solids, — ^A  measured  quantity  is 
evaporated  and  the  residue  dried  to  constant 
weight  at  100^.  Constant  shaking  during  the 
evaporation  is  necessary  to  expel  the  acetic  acid, 
and  a  final  titration  of  the  aoidity  of  the  residue 
is  advisable. 

Alkalinity  of  the  ash. — ^ThiB  may  afford  an 
indication  of  the  probable  origin  of  the  vin^ar, 
a  glucose  product,  for  instance,  showing  a  low 
proportion  of  potassium  oxide  owing  to  the 
mineral  acid  used  for  the  hydrolysis  having 
combined  with  past  of  the  bases.  Variations 
in  the  results  given  by  different  types  of  vinegar 
are  seen  in  the  following  results  : — 


Vinegar  tiom 

grain  and 

malt. 


Alkalinity    at) 
S^Xr    0091^118 
gar  h 


Grain 

and 

sugar. 


003 


Aloe. 


0013 


Sugar. 


trace 


(Allan*  Analyst,  1804,  10»  15). 


Free  mineral  acids. — ^These  are  seldom,  if 
ever,  added  to  vinegar  at  the  present  time. 
Thev  may  be  detected  by  means  of  0*1  p.c. 
methyl  violet  solution,  which  is  not  affected  by 
acetic  acid,  but  is  chiuiged  to  blue  or  green  by 
mineral  acids  (Hilger,  ^ox^h.  Pharm.  1876,  193). 
A  method  of  detecting  and  estimating  free 
sulphuric  and  other  acicu  was  based  by  Hehner 
on  the  fact  that  vinegars  containing  acetates  or 
tartrates  cannot  contaia  free  mineral  acid,  and 
since  on  igniting  these  salts  they  are  decom- 
posed into  carTOnates,  an  examination  of  the 
ash  of  the  vinegar  will  afford  an  indication  of 
the  presence  of  free  acid  (Analyst,  1877,  1,  105). 
A  later  method  devised  by  Richardson  and 
Bowen  (J.  Soc.  Chem.  Ind.  1906,  26, 836)  enables 
an  estimate  to  be  made  of  the  amount  of*  sul- 
phuric acid  originally  added  to  a  vinegar. 

Combined  sulphuric  acid,  —  Commercial 
samples  usuallv  contain  from  about  0*03  to 
0-17  p.c.  of  sulphuric  acid  in  the  form  of  sul- 
phates, quantities  in  excess  of  the  lower  fisure 
usually  being  due  to  the  vinegars  having  been 
made  by  the  conversion  process. 

Added  acetic  acid. — ^No  direct  test  for  added 
acetic  acid  has  been  devised,  and  an  inference  ia 
usually  drawn  from  the  deviation  of  the  figures 
from  those  normally  given  bv  a  vinegar  brewed 
from  barley  malt.  Fincke  s  test  for  formio 
acid,  which  is  usually  present  in  acetic  acid 
{vide  supra),  is  untrustworthy,  since  formic  acid 
is  also  a  normal  constituent  of  grain  and  wine 
vinegars. 

Phosphoric  acid, — ^The  ash  from  10  c.c.  of 
the  vinegar  is  dissolved  in  dilute  nitric  acid, 
and  treated  with  a  large  excess  of  molybdio 
reagent.  The  yellow  precipitate  is  washed  twice 
by  decantation  with  cold  water,  dissolved  in 
ammonia  solution,  and  the  solution  evaporated. 
The  weight  of  the  residue  multiplied  oy  28*5 
gives  the  amount  of  phosphoric  acid  P1O5. 

Nitrogen  is  conveniently  estimated  by 
Kjeldahl's  method  in  10  to  25  c.o.  of  the  vinegar. 
For  comparing  the  results  both  of  phosphoric 
acid  and  nitrogen  in  vinegars  of  different 
strength  Hehner^s  method  of  expressing  them  in 
terms  of  *'  original  solids  '  is  a  convenient,  though 
empirical,  method  (Analyst,  1891,  16,  92 ;  ibuL 
1893,  18,  245). 

Optical  Standard  for  Malt  Vinegar. — ^The 
U.S.A.  Dept.  Agric.  (Circular  No.  19, 1906)  stated 
that  vinegar  made  from  barley  malt  or  cereal  was 
dextrorototory,  but  Chapman  (Analyst,  1912, 
37,  128)  showed  that  the  proteins  and  their 
hydrolytic  products  may  cause  a  vinegar  to 
show  a  Iffivo-rotation. 

Caramel, — ^Added  caramel  may  frequently 
be  precipitated  by  the  addition  of  iuller's  earth. 


ACETIC  ACID. 


23 


but  the  test  is  not  always  satiafaotoiy,  since  the 
amount  removed  varies  with  the  oharaoter  of 
the  earth  (Dubois,  J.  Amer.  Chem.  Soc.  1907, 
29,  75).  A  method  of  precipitation  with  tannin 
is  recommended  by  Lichthardt  (J.  Ind.  £ng. 
Chem.  1910,  2,  389),  but  has  the  drawback  that 
proteins  and  iron  are  also  precipitated  by  tannin. 
Amthor  has  based  a  method  of  detecting  caramel 
on  its  precipitation  by  paraldehyde  (Zeitsch. 
anal.  Chem.  24,  30). 

MeiaUic  Impuriliea, — ^The  chief  metallic 
impurities  to  l>e  looked  for  in  vinegar  are  iron, 
copper,  lead,  and  tin.  The  presence  of  iron 
may  be  detected  bv  adding  potassium  ferro- 
(^anide  directly  to  the  vinegar.  For  the  detec- 
tion of  traces  of  the  other  metals  the  methods 
(suitably  modified)  described  under  Akbated 
Watbbs  may  be  used,  whilst  arsenic  may  be 
detected  and  estimated  by  the  official  method 
of  the  Conjoint  Committee  of  the  Soc.  Chem. 
Ind.  and  Soc.  Public  Analysts  (Analyst,  1902, 
27,48). 

Formic  acid  in  distilled  vin^ar  or  spirit 
vin^ar  may  be  estimated  by  the  method 
recommended  by  Ost  and  Klein  (Chem.  Zeit. 
1908,  32,  815).  The  acid  is  neutralised  with 
alkali  and  titrated  with  permanganate.  Other 
substances  which  reduce  permanganate  must  be 
absent,  which  renders  the  method  inapplicable 
to  ordhiary  malt  and  srain  vinegars. 

Oxalic  acid  may  be  estimated  by  concen- 
trating the  vinegar  and  then  boiling  with  calcium 
acetate  solution. 

Potassium  hydrogen  tartrate  is  estimated  by 
titration  against  N/2  alkali,  and  tartaric  acid  by 
conversion  to  potassium  hydrogen  tartrate  and 
subsequent  titration  (Zeitsch.  anal.  Chem.  1908, 
47,  67). 

(For  the  estimation  of  methyl  alcohol  in 
vinegar,  see  Ann.  Chim.  anal.  1901,  6,  127  and 
171.) 

Cayenne  pepper,  ginger,  and  other  flavouring 
matters  may  be  discovered  by  neutralising  and 
tasting  the  vinegar. 

Chevallier  hae  found  f uchsine  in  French  wine 
vinegars.  C.  A.  M. 

Metaluo  Acetates. 

Alamiiilum  aeetates. 

The  triacetate  or  normal  acetate  Al|(CgH  ,0  3) « 
is  not  known.  A  solution  corresponding  to  this 
compound,  but  which  appears  to  be  a  mixture  of 
the  oiacetate  and  acetic  acid,  is  the  only  acetate 
of  commercial  importance.  It  is  known  as  '  red 
liquor '  or  *  mordant  rouge,*  and  is  largelv  used 
in  dveing  and  calico-printing,  especially  for  the 
production  of  red  colours,  m^der  reds  and  pinks 
(whence  its  name  of  red  liquor) ;  for  the  produc- 
tion of  dense  lakes,  and  for  waterproofing  woollen 
fabrics.    It  is  prepared  by  several  methods. 

A  solution  of  alum  is  added  to  acetate  of 
lime  liquor.  The  lime  is  precipitated  as  sul- 
phate, its  place  being  taken  by  the  aluminium, 
with  the  formation  of  aluminium  acetate ; 
ammonium  or  potassium  sulphate  (according  to 
whether  ammonium  or  potassium  alum  has  been 
used)  is  produced  at  the  same  time.  The 
mixture  is  agitated  and  allowed  to  settle,  and 
a  small  quantity  of  the  clear  fluid  removed  and 
tested  by  the  addition  of  alum ;  if  a  precipitate 
forms  sufficient  alum  has  not  been  usea  and 
more  must  be  added.    The  solution  is  filtered, 


concentrated  to  a  specific  gravitv  of  1*087  to 
1  '10,  and  allowed  to  deposit  any  calcium  sulphate 
still  present.  Calcium  sulphate,  being  sightly 
soluble  in  water,  is  contamed  in  the  liquid  in 
small  Quantity,  and  dimimshes  the  brilliancy  of 
the  colours  produced.  Bv  the  substitution  of 
lead  acetate  for  the  calcium  acetate  a  better 
product  is  obtained.  For  this  purpose  100  lbs. 
alum  are  dissolved  in  50  gallons  water,  and 
treated  with  100  lbs.  finely-powdered  lead  acetate 
with  constant  stirring ;  or,  using  the  same 
quantities,  10  lbs.  crystallised  sodium  carbonate 
are  added  before  the  acetate  of  lead ;  or,  to 
100  lbs.  alum  in  50  gallons  water  6  lbs.  of  car- 
bonate are  added  in  small  portions,  followed  by 
50  lbs.  of  lead  acetate.  The  addition  of  the 
carbonate  is  made  with  a  view  to  the  production 
of  a  basic  aluminium  sulphate  in  addition  to 
the  acetate,  and  as  the  sulphate  assists  the 
mordanting,  less  acetate  is  required.  The 
solutions  are  allowed  to  settle  and  decanted. 
They  contain  the  aluminium  acetate  mixed  with 
basic  aluminium  sulphate  and  alkaline  sulphate. 

An  aluminium  sulpho-acetate  appears  to  act 
satisfactorily.  It  is  prepared  by  mixing  (1) 
453  lbs.  ammonium  alum  (or  383  lbs.  aluminium 
sulphate),  379  lbs.  lead  acetate,  1132  lbs.  water ; 
or  (2)  453  lbs.  alum  (or  333  lbs.  aluminium  sul- 
phate) and  158  lbs.  acetate  of  lime.  The  mix- 
ture ia  agitated,  settled,  and  the  clear  liquid 
decanted. 

By  the  use  of  aluminium  sulphate,  red  liquor 
of  the  same  density  contains  much  more  of  the 
active  alumina  than  that  prepared  with  alum. 
Thus  in  a  sample  of  the  tdtmer  1  sallon  con- 
tained 4  oz.  416  grs.  alumina,  whilst  Uie  average 
amount  found  in  three  samples  prepared  from 
alum  was  3  oz.  245  grs.  The  addition  of  a  little 
ammonia  or  other  alkali  to  the  red  liquor  pre- 
pared from  aluminium  sulphate  is  advantageous 
for  certain  colours.  Red  hquor  usually  conteuns 
from  3  to  5  p.c.  alumina  (AI|0,)  and  6  to  10  p.o. 
acetic  acid;  its  density  varies  from  1*085  to 
1120. 

The  importance  of  the  formation  of  the  gela- 
tinous basic  aluminium  acetate  A1(0'C0CH3)0U 
in  protecting  aluminium  plant  from  the  action 
of  acetic  acid  has  been  mentioned  above. 

Ammonium  acetate  C,U,0,NH4. 

The  crystalline  salt  is  usually  prepared  by 
saturating  glacial  acetic  acid  with  dry  ammonia 
gas.  In  solution  it  may  be  prepared  more 
cheaply  by  neutralising  acetic  acid  solution  with 
ammonia.  On  evaporation,  a  solution  of  the 
salt  loses  ammonia,  and  leaves  the  acid  acetate 
or  diacetate. 

Ordinary  solid  ammonium  acetate  always  has 
an  odour  of  acetic  acid ;  it  is  very  soluble  in 
water  and  alcohol. 

Pure  ammonium  acetate  should  be  entirely 
volatilised  on  heating.  The  commercial  salt 
usually  contains  the  same  impurities  as  sodium 
acetate. 

The  official  ammonium  acetate  solution  of 
the  B.P.  is  prepared  by  neutralising  33  p.c. 
acetic  acid  with  ammonium  carbonate  and 
diluting  the  liquid  to  a  sp.gr.  of  1*016.  When 
treated  with  an  equal  volume  of  a  saturated 
solution  of  hydrogen  sulphide  it  should  not 
darken  in  colour  (lunit  of  heavy  metals). 

Caleium  aeetate.  DiacekUe  of  lime.  Pyro* 
lignite  of  lime,    Ca(CaH,Oa)a. 


24 


ACETJO  ACID. 


1 


ThiB  important  salt  is  preparod  by  neutral- 
ising acetic  acid,  or  pyioligneous  acid,  with  lime 
or  onaik. 

In  the  preparation  from  pyroligneous  acid, 
the  crude  acid  may  be  used,  in  wmch  case  the 
acetate  of  lime  is  known  as  brawn  acetate  ;  or  the 
distilled  liquor  may  be  employed,  producing  grey 
acetate.  The  acid  is  placed  m  l^ige  wooden  or 
iron  pans,  and  powdered  chalk  or  Bme  added  in 
alight  excess;  the  liquor  remains  at  rest  at  a 
warm  temperature  until  clear,  and  is  then 
siphoned  off  into  the  evaporating  pans.  It  is 
generally  evaporated  by  means  oi  coils  of  pipe 
through  whicn  steam  passes;  in  this  case  the 
vessels  are  usually  wooden,  and  lined  with  lead, 
but  sometimes  iron  pans  are  used,  the  evapora- 
tion being  conduct^  over  a  fire.  The  tarry 
impurities  which  rise  to  the  surface  as  the 
liquid  evaporates  are  removed  with  a  skimmer. 
As  the  acetate  forms,  it  is  withdrawn  and 
drained  in  wicker  baskets  suspended  over  the 
pans. 

The  proper  drying  of  the  salt  is  necessary 
to  the  formation  of  a  good  product.  In  laise 
works  a  drying  house  is  used,  which  is  usuaUy 
a  wind  furnace  7  or  8  feet  long,  4^  feet  broad. 
It  is  first  heated  from  15"*  to  115*",  and  the  fire 
slackMied;  the  salt  is  then  spread  over  the 
bottom  to  the  depth  of  about  2  inches,  and  when 
somewhat  dry  an  equal  quantity  is  spread  above 
it,  the  salt  is  repeatedly  turned,  and  the  heat 
continued  for  about  24  hours.  When  the  pro- 
duct appears  to  be  dry,  the  heat  is  increased 
to  about  125^,  and  the  last  traces  of  moisture 
driven  off.  Care  must  be  taken  that  the  heat 
is  not  too  high,  or  the  salt  becomes  decomposed. 
As  in  the  case  of  sodium  acetate,  no  sparks 
must  touch  the  mass,  or  it  may  bum  away  like 
tinder. 

The  product,  when  prepared  from  the  hroum 
liquor,  is  dark-coloured  and  contains  char- 
coal and  decomposed  tany  matters ;  it  may  be 
dissolved  in  3  parts  hot  water,  filtered  through 
animal  charcoal,  and  again  evaporated  and 
crystalliBed,  yielding  a  nearly  colourless  product. 

Pure  calcium  acetate  crystallises  m  silky 
needles  or  prisms  containing  two  molecules  of 
water.  At  the  ordinary  temperature  the  crystals 
effloresce,  and  at  100°  become  anhydrous, 
forming  a  white  powder  of  saline  taste,  very 
soluble  in  water. 

Calcium  acetate  is  used  in  the  preparation  of 
oth^  acetates,  and  of  acetic  acid,  and  in  calico- 
printing.  The  pure  salt  is  completely  soluble  in 
water  and  proof  spirit.  The  commercial  article 
usuaUy  contains  62  to  67  p.c.  of  real  acetate, 
and  I  to  8  p.c.  of  matters  insoluble  in  water. 
The  impurities  are  hydroxide,  carbonate,  and 
sulphate  of  calcium  and  tarry  matters ;  formate 
ana  other  salts  of  calcium  with  fatty  acids  also 
occur. 

Many  methods  of^usay  for  this  substance 
are  in  use,  var3ring  considerably  in  accuracy. 

The  most  trustworthy  method  is  to  clistil 
with  pure  phosphoric  acid  and  titrate  the  distil- 
late as  already  described  under  acetic  acid  {see 
StUlwell,  J.  Soc  Chem.  Ind.  1904,  305 ;  Gros- 
venor,  ibid.  630 ;  Gladding,  J.  Ind.  £ng.  Chem. 
1909,  250).  The  acetic  acid  may  also  be 
expelled  by  evaporation  *  with  formic  acid 
(Ueermann.  Chem.  Zeit.  1915,  39,  124). 

Caldttm  aoeto-chlorlde  CaC|U,0,Cl,51£,0  has 


already  been  described  as  iised  in  Condy's  process 
for  the  preparation  of  pure  acetic  acid. 

Copper  aaetates. 

The  normal  copper  acetate  is  {aepared  by 
dissolving  cuprio  oxide  or  verdigris  in  acetic 
acid ;  orby  the  action  of  copper  sulphate  on  the 
acetates  of  lead,  calcium,  or  bariunL 

It  crystallises  in  prisms ;  soluble  in  13  parts 
cold  or  5  parts  hot  water,  and  in  14  parte 
alcohol.  In  commerce  it  usually  ocours  in 
bunches  of  deep-green  coloured  opaque  orystab 
known  as  *  grappee.* 

Copper  acetate  is  used  in  the  manufacture 
of  pigments ;  as  an  oxidising  agent  in  the  indigo 
vat ;  and,  formerly,  for  the  preparation  of 
acetic  acid. 

Basie  copper  acetate.  Verdigris*  Vtrt^dt^ria. 
\  ert  de  Mantpellier,  QrUn$pai^ 

This  substance  consists  of  a  mixture  of  mono-, 
di-,  and  tri-basic  acetates  of  copper,  which  arr 
present  in  different  proportions  in  different 
varieties  of  verdigris. 

At  Grenoble  and  Montpellier  the  following 
prooen  is  used  :  The  *  maics  '  or  residues  fcom 
the  wine  factories,  consisting  of  the  skins  and 
stems  of  grapes,  are  loosely  placed  in  earthen 
vessels,  about  16  inches  high,  14  inches  in 
diameter  at  the  widest  part,  and  12  inches  at  the 
mouth,  covered  and  allowed  to  ferment,  until 
on  inserting  a  piece  of  copper  (previously 
moistened  with  verdigris  and  aried),  it  becomes 
uniformly  coated  green  in  24  hours.  The 
fermentation  should  not  proceed  too  far,  or 
decomposition  may  ensue. 

The  copper  used  is  in  sheets  ^  inch  thick,  4 
to  6  inches  long,  and  3  to  4  broad^  each  weighing 
about  4  oz. ;  they  are  freed  from  scales,  if  neces- 
sary, rubbed  with  a  solution  of  verdigris  and 
dried  ;  unless  this  precaution  be  adopted,  the 
first  coating  produced  by  the  marcs  will  be 
black  instead  of  green.  They  are  heated  over  a 
charcoal  fire  untU  as  hot  as  the  hand  can  bear, 
and  placed  in  an  earthenware  vessel  in  layers 
with  the  marcs.  30  to  40  lbs.  of  copper  are 
used  for  each  vessel.  In  from  ten  to  twenty 
days,  according  to  the  temperature,  the  coveri 
are  removed,  when,  if  the  process  has  pro- 
gressed favourably,  the  marcs  will  be  whitisl] 
and  the  copper  covered  with  fine,  glossy,  green 
crystals.  The  plates  are  then  removed  and 
placed  on  end  one  against  another.  After  two 
or  three  days  they  are  moistened  by  immersion 
in  water  or  damaged  wine,  and  again  plaoed  on 
end  for  about  a  week.  This  alternate  moisten- 
ing and  exposure  to  the  air  is  continued  for 
about  six  or  eight  weeks.  The  plates  thus  be* 
come  covered  witji  increasing  coatings  of  the 
verdigris,  which  is  detached  and  the  plates  are 
again  used  until  entirely  eaten  away.  The 
verdigris  is  kneaded  with  a  little  water  into 
leather  bags,  pressed  into  rectangular  cakes  and 
dried. 

This  substance  is  known  as  blue  verdigris, 
and  consists  principally  of  the  basic  acetate 

(C,H,0,),CuaO. 

It  should  be  dry,  of  a  fine  bluish  colour,  and 
soluble  in  dilute  acids  and  ammonia. 

Oreen  verdigris  contains  as  a  principal  consti- 
tuent the  sesquibasio  acetate,  CuO-2Cu(CjH,0|),, 
and  is  prepared  by  placing  the  copper  platui 
alternately  with  doths  moistened  every  two  or 


ACKTIC  ACia 


» 


three  da js  wiUi  pyroligapom  acid  or  a^rv^uc  acid 
■niil  th«  plates  ikiow  imn  cryttrnku  Tlie  pUtea 
are  anaofeed  ao  as  to  allow  fm  aeeeae  oi  air  and 
oocaaioiiallr  moialaied,  for  fire  or  cjjt  wek& 
LaiY^eqaantitJBSof  verdicrisare  maauiaitured  in 
Kngland  b j  tiua  procets  tioai  pyrol^pMoua  ackL 
The  iraportB  of  Todizris  are  verf  analL 

In  Abresh's  pcoi>t^  iPr.  Pat.  391ti<C».  190S) 
minerals  contaimng  the  oiide  or  carbonate  of  | 

apper  are  decomposed  with  15  pic.  acetic  acid 
ntion,  the  exoe«  of  acid  neutralised  or  dis- 
tilled, alkali  added  to  pRcipitate  iron  alumi- 
niom,  cakanm,  Ac,  toe  liqiud  filtered  and 
oQoceatrated,  and  the  copper  acetate  separated 
by  crystallisation. 

The  Tanoas  forms  of  Terdigiis  ars  nsed  as 
oU  and  water  coloanL  With  white  lead  it  i3 
used  in  Rossia  and  Holland  as  an  oil  paint, 
which  by  double  decomposition  prodaces  a 
peonliar  gieen.  The  paint  is  considered  »  good 
preeervative.  VenUgiis  is  nsed  ia  dj^eing  and 
calloo-|irinting,  and  lor  the  preparation  of 
Sehwemfuth  gieen  and  other  copper  paints. 

Veidigris  is  frequently  adolto^^ed  with  chalk, 
sand,  clay,  pomice,  and  sulphates  of  copper, 
barium,  and  ralrinm     When  brass  sheets  have  ' 
been  used  in  the  piepaiaiion  instead  of  copper, 
zinc  will  also  be  present. 

When  warmed  with  dilate  hydrochloric  acid 
the  sand,  clay,  baryta,  Ac,  will  remain  undis- 
solyed,  and  may  be  weighed.  The  total  residue 
in  a  good  samj^  will  usually  amouit  to  3  p.c, 
but  would  not  exceed  6  p.c 

AMto-amnttt  of  ooppw.  SekiceitifiuFih  gntn 
im  Ahsesic) 

*  Fente  aeotato  Fe,(CtH,OJ,.  This  salt  is 
prepared  by  the  addition  of  calcium  or  lead 
acetate  to  ferric  sulphate  or  iron  alum,  avoiding 
excess  of  the  acetete.  It  is  used  as  a  mordant, 
ite  action  corresponding  with  that  of  aluminium 
acetete.  An  aicoholic  solution  is  used  in 
medicine,  but  is  no  longer  an  official  drug  in 
the  B.P. 

For  many  purposes  a  mixture  of  ferrous  and 
ferric  acetetos  is  preferred.  It  is  prepared  by 
repeatedly  pouring  pyroligneons  acid  on  iron 
turnings  until  saturated  with  iron.  The  liquid 
is  known  as  *  pyrolignito  of  iron,'  *  bouillon  noir,* 
*  liqueur  de  ferraille.' 

Ferrous  aeotate  Fe(GaH,0,),.  PyroLigniU  of 
iron;  iron  liquor  or  Uack  liquor.  Is  prepared 
on  ^e  large  scale  by  the  action  of  crude  pyrolig- 
neous  acid  of  sp.gr.  1*035  to  1*040  on  iron 
turnings,  nails,  Ac,  at  a  temperature  of  65°. 
The  solution  is  iiequently  agiteted  and  the 
tarry  matters  skimmed  from  the  surface  as  they 


It  is  found  that  the  purified  acid  produces  a 
satisfactory  liquor,  a  fact  due,  according  to 
Moyret  (J.  See.  Dyers,  i.  117),  to  the  presence  of 
a  small  quantity  of  pyrocatechol  in  the  crude 
acid,  which  forms  a  compound  with  the  ferro- 
soferric  oxide  in  the  solution,  and  causes  its 
intense  colour  and  keeping  properties. 

The  liquid  is  intensely  btack,  of  sp.gr.  1*085 
to  1  *090,  and  is  evaporated  until  its  density  rises 
to  1*120,  or  sometimes  to  1*140.  It  is  then 
ready  for  uae,  and  is  known  as  *  printer's  iron 
liquor.'  The  liquor  of  density  1*120  contains 
about  10  p.c.  iron. 

The  density  of  the  liquor  used  by  dyers  is 
frequently  raised  by  the  addition  of  copperas 


.  firrroQs  5nilphate) ;  thiisk  the  adiliiKMS  to  I  galktt 
of  hUck  bqitor,  sp-cr.  It^x  of  J  IK.  cop|w*fttS» 
would  nuse  ite  deosaiy  to  1*111.  Tannin  also  it 
sometmtes  added. 

BUck  lk]uor  is  also  prepared  by  the  action  ol 
ferrous  sulphate  on  acetate  of  hiue ;  the  liqu««r 
pixxiuoed  has  an  average  density  of  1*11,  ami 
always  oonteini  cakium  sulphate  By  the 
action  of  lead  acetate  on  fenous  caHxHiate, 
carbonate  of  lead  and  fuuuua  acetate  are  pio> 
duced. 

Black  liquor  absorbs  oxygen  fiom  the  air» 
forming  ferric  acetate,  whic&  is  always  prparat 
in  the  liquid.  To  di"^inifth  this  action  clean 
metallic  iron  is  frequently  added. 

It  is  lai^Eely  used  in*  calico-prmting  and  in 
dyeing,  in  the  preparation  of  blue»  violet,  black, 
brown,  and  otncr  colours,  and  f6r  producing  n 
black  colour  on  hats,  furs,  leather,  wood,  Ac 

Lead  aaateta,  yormal  or  di-uc«tei«  of  kad. 
SH*jar  of  had.  Sd  d€  ^MUame.  BUisucktr, 
Pbi0,H,0,),. 

For  the  nreparation  of  wMiU  cwstaie  of  lead, 
leaden  vessels  are  used,  or  copper  pans,  on  the 
bottom  of  each  of  which  a  piece  of  metallic  lead 
is  soldered  to  produce  a  galvanic  action  and 
prevent  the  copper  from  being  acted  upon.  In 
the  ves^l  acetic  acid  of  45  p.c  or  lees  is  placet), 
and  to  100  parte  of  45  p.c,  or  a  proportionate 
quantitv  of  a  weaker  acid,  8^*5  parts  of  litharge 
are  added  in  small  quantities,  with  constant 
stirring,  until  the  liquid  is  nearly  neutral ;  it  is 
then  heated  to  boiling  and  impurities  skimmer! 
from  the  surface,  transferred  to  another  vessel, 
evaporated  to  a  density  of  1*5,  and  removed  to 
the  crystallising  pans,  which  are  usually  of 
wood,  lined  with  lead  or  copper,  4  feet  by  2  fet^t, 
and  6  or  8  inches  hi^h.  The  coarsely  crystalline 
mass  thus  obtained  is  drained  on  wooden  racks, 
and  broken  into  lumps  for  the  market. 

A  cocurser  variety,  known  as  brown  acftaitt  is 
prepared  by  substituting  distilled  pyroligneons 
acid  for  the  purer  acid.  The  muddy  liquid  pro- 
duced is  left  to  settle  in  a  large  tun,  and  the 
supernatant  liquid  transferred  to'a  large  iron  i>an 
and  heated  to  boiling..  It  is  again  allowecl  to 
settle,  transferred  to  another  pan,  evaporated 
untU  crystallisation  commences,  when  about  3 
volumes  of  water  added,  causing  the  remaining 
impurities  to  riae  to  the  surface.  The  liquid  is 
skimmed  and  diluted  if  the  liquid  is  not  suflli- 
ciently  clear,  and  again  evaporated  until  a  small 
portion  crystallises  when  removed  and  cooled. 
It  is  then  ladled  into  pans  and  allowed  to 
crystaUise. 

As  a  rule,  aborut  3  parte  acetete  are  produced 
from  2  parts  litharge. 

By  another  method  granulated  lead,  white 
lead  residues,  &o.,  are  placed  in  vessels  stending 
obliquely  one  above  another  ;  the  upper  vessel  is 
filled  with  strong  acetic  acid,  which  after  the 
expiration  of  half  an  hour  is  allowed  to  run  into 
the  second  vessel.  Every  half-hour  it  is  re- 
moved to  a  lower  one.  Alter  the  acid  has  been 
removed,  the  lead  absorbs  oxygen  rapidly,  and 
becomes  heated.  On  leaving  the  last  vessol, 
the  acid  is  again  passed  through  the  series,  dis- 
solving the  acetete  which  has  been  formed,  and 
is  evaporated  and  crystallised. 

Schmidt  (Eng.  Pat.  7192,  1897)  describes  a 
process  for  preparing  the  neutral  and  basic 
acetetes  of  metaU  such  as  lead  and  copper  by 


20 


XCETIO  AOID. 


the  action  of  dilute  acetio  aoid  and  oxygen  upon 
the  metal  contained  in  closed  iron  cylmden. 

Pure  lead  acetate  is  a  white  crystalline  salt 
of  sweetish  taste  and  weak  acid  reaction,  con- 
taining 3  molecules  of  water.  100  parts  of  water 
dissolve  54*38  parte  at  26**,  87'77  parts  at  Z^", 
and  154-26  parts  at  46^  At  280°  it  melts,  and 
when  heated  more  strongly  it  forms  a  basic  .salt 
and  suddenly  solidifies. 

Lead  acetate  is  largely  used  in  dyeing  and 
calico-printing;  for  the  preparation  of  alum 
mordants,  &c. ;  in  the  manuiactuze  of  chrome 
yellow  and  other  pigments,  and  in  medicine. 

Lead  forms  two  well-defined  basic  acetates 
—the  dibasic  acetate  Pb(C,H,0,),PbO,2H,0 
(Wittstein,  Annalen,  52,  253),  formed  by  dls- 
solying  lithaige  in  the  normal  acetate  in  cal- 
culated proportions;  and  the  tribasic  acetate 
Pb(0,H,Os)a2PbO'aq,  prepared  by  boiling  the 
normal  acetate  with  ezoese  of  litharge  for  some 
time.  Lead  acetate  and  solutions  of  subacetate 
of  lead  are  official  drugs  of  the  B.P.  The 
solutions  are  termed  Qaiuard  water  and  Liquor 
jdumbi  subaceiatis. 

In  1911  the  annual  production  of  white 
acetate  in  Germany  was  estimated  at  2600  metric 
tons,  about  half  of  which  was  exported,  mainly 
to  Great  Britain  (Badermann,  Zeitsch.  angew. 
Chem.  1911,24,1211).  • 

Leadfab-aeetateCH,'COaPb  may  be  obtained 
by  the  action  of  acetic  anhydride  on  lead  sub- 
oxide at  195°.  It  is  a  bluish-grey  substance, 
soluble  in  alcohol  (Denham,  Chem.  Soo.  Trans. 
1919,  109). 

Magneiium  aeetate.  A  basic  acetate  of  mag- 
nesium, prepared  by  warming  the  normal 
acetate  with  magnesia,  is  stated  to  be  a  powerful 
antiseptio,  disinfectant,  and  deodoriser  (W. 
KubeC  Ber.  15,  684-686).  A  syrupy  solution 
of  the  salt  containing  suspended  macnesium 
hydroxide  is  found  in  commerce  under  the  name 
of  '  Sinodor.' 

Potassium  acetate  C,H,OaK  occurs  in  the  sap 
of  many  plants,  and  of  trees. 

Its  mode  of  preparation  is  similar  to  that  of 
sodium  acetate.  It  iB  a  deliquescent  crystalline 
solid,  soluble  in  0*53  part  ice-cold  water,  and  in 
hot  water  forms  a  solution  which,  boiling  at 
160°,  contains  88  p.c.  of  the  salt. 

When  chlorine  gas  is  passed  through  a  solu- 
tion of  potassium  acetate,  carbon  dioxide  is 
evolved  and  a  powerful,  unstable,  bleaching  fluid 
is  produced. 

Potassium  acetate  may  contain  the  same 
impurities  as  the  sodium  salt.  The  di-  and  tri- 
acetates  are  prepared  like  those  of  sodium. 

Sodium  aeetate  C|H,OtXa  is  formed  (1)  by 
the  action  of  dilute  acetio  acid  on  sodium  carbo- 
nate, the  solution  being  evaporated  and  crystal- 
lised ;  (2)  by  neutralisation  of  pyroligneous  acid 
with  soda,  and  evaporation  and  fusion  of  the  salt 
to  remove  tarry  matters ;  (3)  by  the  addition  of 
Glauber's  salt  to  solution  of  acetate  of  lime  or 
of  lead.  The  solution  Lb  decanted  and  filtered 
from  the  precipitated  calcium  or  lead  sulphate, 
evaporated  and  crystalliBed,  and  the  crystals 
dissolved  and  recrystallised.  Methods  (2)  and 
(3)  are  used  on  the  manufacturing  scale. 

Sodium  acetate  forms  monodinic  crystals, 
containing  3  molecules  of  water ;  has  a  strong 
saline  taste ;  is  soluble  in  2*8  parte  cold  water 
and  in  0*5  boiling  water.    The  crystals  melt  com- 


pletely at  75°  and  lose  their  water  of  crystallisa- 
tion at  100°.  By  solution  of  this  salt  in  ordinary 
strong  acetic  acid  and  rapid  evaporation  the  di- 
acetate  of  soda  is  formed;  when  glacial  acid  is 
used  the  triacetate- is  produced. 

Sodium  acetete  is  used  for  the  preparation  of 
acetic  acid  and  in  medicine,  but  is  not  official  in 
the  B.P. ;  for  the  preservation  of  meat  and 
other  foods  instead  of  salt.  The  saturated 
solution  is  occasionally  used  for  filling  carriage 
foot-warmers. 

The  commercial  acetete  is  liable  to  contain 
sulphates,  chlorides  and  carbonates,  and  me- 
tallic salto.  Tarry  matters  are  frequently  pre- 
sent from  the  pyroligneous  acid  used  in  iU 
manufacture.  Acetete  of  lime,  and  sulphate 
and  carbonate  of  potassium  are  occasionally 
added  as  adulteranto. 

For  the  estimation  of  acetic  acid  in  com- 
mercial aoetetes  the  method  of  Stillwell  and 
Gladding  in  a  modified  form  Lb  used  (v.  supra). 

Titanium  aeetate.  A  double  acetete  of 
titanium  has  been  patented  by  Kunheim  (Ger. 
Pat.  248251,  1911).  It  lb  prepared  by  adding 
excess  of  an  alkali  solution  to  a  strong  solution 
of  a  salt  of  trivalent  titanium,  and  crystallising 
the  double  salt  in  a  vessel  from  wmch  air  is 
excluded. 

Anhydrous  metallic  acetetes  may  be  obteined 
by  the  action  of  acetic  anhydride  on  nitrates 
containing  water  of  crystellisation.  The  re- 
action IB  accelerated  catalytically  bv  acids 
and  also  apparently  by  water,  as  anhydrous 
nitrates  do  not  react  so  readily  (Spath,  Monatah. 
1912,  33,  235). 

Alkyl  Acetates.    Acetic  esters. 

Acetic  acid  forms  numerous  acetetes  with 
organic  radicals.  Some  of  these  occur  in  the  oils 
from  various  seeds. 

Amyl  aeetetes  CsHn(0,H,O.). 

The  following  isomeric  amyl  acetetes  are 
known : — 

1.  Normal  amyl  acetete,  boiling  at  147*6° 
(Gartenmeister) ;  at  148*4°  (737  mm.)  (Lieben 
and  Rossi). 

2.  /aoamyl  acetete. 

3.  Methyl  propyl  carbinyl  acetete,  boiling  at 
133°-135°  (Wurtz) ;  at  134°-137°  (Schorlemmer). 

4.  Methyl  Mopropyl  carbinyl  acetete,  boiling 
at  125°  (Wurtz). 

5.  Diethyl  carbinyl  acetete,  boiling  at  132° 
(741  mm.)  (Wagner  and  Saytzeff). 

6.  Tertiary  amyl  acetete,  boiling  at  124° 
(750  mm.)  (Flavitzky). 

Of  these,  only  the  second  is  of  technical 
interest. 

idoAmyl  acetete,  generally  known  as  amyl 
acelate  (CH,),CHCH,CH,OCr,H,0,  is  a  colour- 
less  liquid  with  an  odour  resembling  that  of 
jargonelle  pears.  Sp.gr.  08762  15°/4^  (Mende- 
16eff).  0-8562  2274°  (Briihl),  b.p.  138-5°-139°  at 
758-6  (Schiff). 

It  may  be  prepared  by  distilling  a  mixture  of 
1  part  amyl  alcohol,  1  part  strong  sulphuric 
acid,  and  2  parte  dried  potassium  acetete  ;  or  by 
warming  a  mixture  of  1  part  amyl  alcohol,  1 
part  acetic  acid  and  0*5  part  strong  sulphurio 
acid  on  the  water- bath  and  pouring  uie  solution 
when  cold  into  excess  of  water.  The  upper 
layer  of  purified  amyl  acetete  is  separated,  shaken 


ACETIC  ANHYDRIDE. 


17 


with  A  strong  aolntion  of  aodium  carbonatey 
again  separated,  dried  over  oalciam  cMoridoy 
and  redisUlled. 

It  may  be  prepared  commercially  £rom  fusel 
oil,  hydrochloric  acid,  and  calcium  acetate 
(Wilson,  Eng.  Pat.),  and  by  the  interaction  of 
ohloropentane  with  sodiom  acetate,  in  the 
pesence  of  strong  acetic  acid.  To  prevent  the 
formation  of  amylene  the  sodium  acetate  should 
be  in  a  porous,  bulky  condition  (Kaufler, 
Eng.  Pat.  2779,  1913).  The  commercial  amyl 
acetate  contains  some  ol  the  other  isomerides. 

It  is  insoluble  in  water,  but  dissolyes  in  all 
proportions  in  ether,  amyl  alcohol,  and  ordinary 
alcohol.  The  latt^  solution  is  largely  used 
under  the  name  ol  Jairgandle  pear  eawnce  for 
flavouzins  confectionery. 

Camnhor,  tannin,  resins,  &c,  dissolve  readily 
in  amyl  acetate.  A  solution  of  eun- cotton 
therein  is  used  as  a  yamish,  for  lacquering 
metals,  &c.,  and  in  the  form  of  a  stiff  jelly, 
mixed  with  opaque-  substances  such  as  china 
clay,  as  a  substitute  for  celluloid. 

It  is  also  used  in  the  manufacture  of  photo- 
graphic films  and  in  some  smokeless  powders. 

It  has  been  recommended  for  use  for  the 
production  of  a  standard  flame  in  photometry 
(J.  Soc.  Chem.  Ind.  1885,  262). 

The  Hefner  standard  lamp  bums  amyl 
acetate  as  an  illuminant. 

Ett^l  Metate.  Acetic  ether  C,Hfi(C|H,0,)  is 
a  fragrant  limpid  liquid  of  sp.gr.  092464  074"". 
b.p.  77 '15*^  (Wade  and  Merriman) ;  8p.gr. 
0-92446  074^  b.p.  77  17**  at  760  mm.  (Young 
and  Forty). 

For  the  preparation  of  acetic  ether  3*6  pts. 
by  weight  of  commercial  absolute  alcohol  are 
mixed  with  9  pts.  sulphuric  acid  with  constant 
stirring.  After  standmg  twenty-four  hours  the 
mixture  is  poured  on  6  pts.  of  fused  -sodium 
acetate  (in  small  lumps),  allowed  to  stand  for 
twelve  hours  and  distilled.  The  product  is 
rectified  over  calcium  chloride  and  potassium 
carbonate  and  redistilled. 

Clark  reconmiends  the  following  process : 
283  C.C.  (10  oz.)of  rectified  alcohol (sp.gr.  0838) 
are  placed  in  a  flask,  and  283  c.o.  of  sulphuric 
acid  (B.P.)  are  added  with  constant  stirring. 
The  liquid  should  be  cooled  externally  as  far  as 
possible,  allowed  to  stand  till  the  temperature 
nas  sunk  to  15°,  and  351  grams  (12}  oz.)  of  dried 
sodium  acetate  added  gradually,  with  constant 
stirring  and  cooling.  The  liquid  is  distilled 
until  400  CO.  (14  oz^  have  passed  over ;  this  is 
digested  for  three  days  with  2  oz.  freshly  dried 
potassium  carbonate  and  filtered.  The  filtrate 
IB  distilled  on  the  water- bath  until  all  but  1  oz. 
has  passed  over.  On  the  lar^e  scale  dried 
sodium  acetate  may  be  substituted  for  the 
potassium  carbonate  with  advantage  {v.  further 
W.  L  Chxk,  Pharm.  J.  [3]  1883,  777). 

Ethyl  acetate  may  be  prepared  by  the 
action  ol  an  aluminium  alkyl  oxide  on  acetalde- 
hyde  in  the  presence  of  aluminium  chloride, 
which  has  preferably  been  added  during  the 
preparation  of  the  alkyl  oxide  from  aluminium 
and  alcohol ;  or  the  melted  alcoholate  may  be 
dissolved  in  anhydrous  camphor,  alum,  Ac,  to 
increase  the  catalytic  action  (Consortium  f. 
Elektroohem.  Ind.,  Ger,  Pat,  286812,  1914; 
Eng.  Pat.  4887,  1915). 

1a  the  process  of  Farbwerke  vorm.  Meister, 


Lucius  and  Bruning  (Eng.  Pat.  12S8,  1915) 
acetaldehyde  is  treated  with  a  filtered  solution 
of  aluminium  tthoxide  in  an  organic  solvent, 
such  as  xylene  or  solvent  naphtha  at  0^-15°,  a 
yield  of  about  86  p.a  of  the  theoretical  amount 
of  ethyl  acetate  oeing  claimed  (c/.  Senderens 
and  Aboulenc,  Compt.  rend.  1911,  152,  1671; 
Kurtenacker  and  Habermann,  J.  pr.  Chem. 
1911  [iil83,  541). 

Ethyl  acetate  is  soluble  in  8  parts  of  water 
at  0**,  and  somewhat  less  soluble  in  water  at 
15^  On  the  other  hand,  1  part  water  dissolves 
26  parts  of  the  aceUte  at  O""  and  24  parts 
at  15^ 

Commercial  acetic  ether  usually  contains  less 
than  75  p.c.  of  ethyl  acetate,  the  rest  being 
acetic  acid,  alcohol,  water,  ether,  &c.  It  occurs, 
together  with  other  organic  acetates,  in  viniQgar 
and  wines. 

Methyl  aeetate  CH,(C.H,0.)  is  a  colourless 
fragrant  liquid  of  sp.gr.  0*9398  15^15^,  boiling 
at  57*5**  (760  mm.)  (Perkin).  It  occurs  in  wood- 
spirit,  and  in  crude  wood- vinegar. 

Methyl  acetate  is  best  prepared  by  distilling 
a  mixture  of  1  part  methyl  alcohol,  1  part  potas- 
sium acetate,  and  2  parts  sulphuric  acid.  The 
product  is  dried  over  calcium  chloride  and  quick- 
lime and  redistilled.  It  Ib  soluble  in  water, 
alcohol,  and  ether. 

A  solvent  for  resins,  fats,  oePulose,  nitrate, 
&c.,  which  consists  largely  of  methyl  acetate, 
may  be  prepared  by  distilling  pyroliffneous 
acid  until  a  tenth  of  its  volume  has  passed  over, 
then  adding  a  mineral  acid,  and  continuing  the 
distillation  until  a  third  of  the  residue  has 
distilled.  The  united  distUlates  are  then 
rectified  (Heilbronner  and  Criquebeuf,  Fr.  Pat. 
464646,  1913). 

ACETIC  ANHYDRIDE  (CH,CO),0  is  formed 
smoothly  and  quantitatively  by  heating  acetyl 
chloride  with  a  metallic  acetate.  It  is  not, 
however,  necessary  to  make  a  separate  pre- 
paration of  the  acetyl  chloride  and  almost  any 
reaction  which  yields  acetyl  chloride  will  yield 
acetic  anhydride  if  an  excess  of  metallic  acetate 
be  employed.  The  method  originally  employed 
by  Gerhardt  (Ann.  Chim.  Phys.  1863,  [3]  37 
285)  consisted  in  treating  an  exc^  of  anhydrous 
potassium  or  sodium  cu;etate  with  a  chloride  or 
oxychloride  of  phosphorus.  Later,  Geuther 
(Annalen,  1862,  123,  114)  showed  that  the 
reaction    occurs    according    to    the    equation 

4CH,C00Na+P0Cl, 

=2(CH,CO)aO-l-8NaCl-f-NaPOg 

This  method  is  a  satisfactory  one,  but  since 
acetic  anhydride  has  become  an  article  of  com- 
mercial interest,  it  has  been  found  desirable  to 
substitute  a  cheaper  reagent  for  the  phosphorus 
compound.  In  nearly  all  the  commercially 
practicable  processes  an  anhydrous  chloride  or 
oxychloride  of  sulphur  is  employed. 

Svlphur  chlorides.  The  use  of  the  chlorides 
of  sulphur  instead  of  those  of  phosphorus  has 
been  known  for  a  very  long  time  (Heintz,  Jahr. 
1856,  569),  but  these  liquids  are  unpleasant  to 
handle,  and  their  action  is  not  easy  to  control. 
The  action  of  sulphur  monochloride  on  the  alkali 
salts  of  organic  acids  has  been  studied  by 
Denham  and  Woodhouse  (Chem.  Soc.  Trans. 
1909,  1235,  and  1913,  1861),  who  used  an 
indifferent  solvent  to  dilute  the  reagent  and 


28 


ACETIC   ANHYDRIDE. 


control  its  local  action.  By  treating  dry  sodium 
acetate  with  Bulphur  monochloride  S.Clt,  in 
presence  of  a  neutral  solvent,  Denham  ootained 
an  intermediate  compound  (CH,COO)^,,  which 
breaks  up  on  heating,  according  to  the  equation 
2(CH,COO)^,=2(CH,CO),0+SO,+3S.  Den- 
ham^s  reaction,  however,  does  not  provide  for 
the  maximum  technical  utilisation  of  the 
reagents,  since  the  sulphur  dioxide,  as  an  inor- 
ganic anhydride,  should  be  capable  of  taking 
part  in  the  reaction  and  Bhonld  not  be  allowed 
to  escape  unused. 

Kesskr  (Fr.  Pat.  315938,  1901),  in  making 
use  of  the  action  of  sulphur  chloride  on  anhydrous 
sodium  acetate,  claims  that  by  diBtilling  off  the 
acetic  anhydride  at  a  low  temperature  under 
reduced  pressure,  the  production  of  sulphur 
dioxide  is  avoided.  Whether  this  is  the  case  or 
not,  it  is  nevertheless  certain  that  the  distilla- 
tion of  the  acetic  anhydride  under  reduced 
pressure  constitutes  a  definite  technical  advan- 
tage when  steam-heated  vesseLs  are  used,  and 
this  procedure  has  remained  standard  practice 
in  all  subsequent  methods. 

H.  DieWus  tEng.  Pat.  100450,  1916)  has 
clearly  set  forth  the  principles  which  govern  the 
technical  manufacture  of  acetic  anhydride  by 
the  action  of  sulphur  chloride  on  dry  sodium 
acetate,  in  order  to  avoid  the  production  of 
sulphur  dioxide  and  of  chloroacetic  acids  by 
substitution,  (a)  The  reagents  are  used  in  the 
proportion  of  6  atoms  of  chlorine  to  8  of 
sodium;  (6)  the  reaction  is  allowed  to  take 
place  in  presence  of  a  diluting  agent,  in  order 
to  avoid  any  local  excess  of  sulphur  chloride  and 
overheating,  for  which  purpose  acetic  anhydride 
is  most  conveniently  employed ;  (c)  the  sulphur 
chloride  is  run  slowly  into  the  well-cooled  mixture 
of  sodium  acetate  and  acetic  anhydride  and  the 
temperature  is  not  allowed  to  rise  above  15^  C. 
until  all  the  sulphur  chloride  has  been  added. 
For  example :  a  mixture  of  720  kilos  of  dry 
pulverised  sodium  acetate  and  600  kilos  of 
acetic  anhydride  is  cooled  below  0°  C,  and 
306  kilos  of  sulphur  dichloride  is  gradually 
introduced,  the  temperature  being  maintained 
at  about  0^  and  the  mixture  continually  stirred. 
Stirring  is  continued  for  some  time  after  all  the 
sulphur  dichloride  has  been  added  and  the 
anhydride  is  subsequently  distilled  off,  pre- 
feraoiy  in  vacuo.  The  equations  representing 
this  reaction  for  sulphur  monochloride  and 
dichloride  respectively  may  be  written : 

8CH,COONa+3S,Cl, 

=4(CH,CO),0+6Naa+Na,S04+5S 
8CH,COONa+3Sa, 

=4(CH,CO),a+6Naa-fNa,S04+2S 

Thus  there  is  a  loss  of  sulphur  which  is 
obviously  minimised  by  employing  a  sulphur 
chloride  as  rich  as  possible  in  chlorine.  Tins 
waste  of  sulphur  may  be  avoided  altogether 
according  to  the  process  of  the  Akt.  Ges.  fiir 
Anilmfab.  (Ger.  Pat.  273101 ;  J.  So?.  Chem.  Ind. 
1914,  667)  by  passing  chlorine  gas  into  a  mixture 
of  sodium  acetate  and  sulphur  chloride  at  a 
temperature  not  exceeding  20°  C,  thus : 

8CH,COONa+SCl,+2Cl, 

=4(CH,C0),0 + 6Naa-l-Na,S04 

T!:e  above  is  a  variant  of  Goldscbmidt's  pro- 
(Eng.  Pat.  25433,  1(;08),  in  which  the  whole 


of  the  sulphur  chloride  is  generated  in  siiu  by 
the  action  of  6  atoms  of  chlorine  on  1  atom  of 
sulphur  at  a  low  temperature  in  presence  of 
8-9  mobk  of  sodium  acetate.  The  sulphur  may 
be  replaced  by  a  metallic  compound  containing 
sulphur,  e.g.  ferrous  sulphide  (1st  addition  to 
Fr.  Pat.  408065),  and,  according  to  a  later 
addition  to  the  same  patent  {Dw,  29,  1910), 
the  intense  cooling  is  not  necessary  and  the 
reaction  may  be  conducted  at  temperatures 
up  to  40^-50°  C.  A  similar  process  is  patented 
by  de  Jahn  (Eng.  Pat.  5039,  1910),  m  which 
several  oxidisable  compounds  of  sulphur  may 
be  used,  but  it  is  obvious  that  these' must  be 
anhydrous. 

Oxychhrides  of  Sulphur, — ^Thionyl  chloride 
reacts  with  dry  sodium  acetate  giving  acetic 
anhydride  and  sulj^ur  dioxide  (G.  Wyss,  BulL 
Soc.  Ind.  Mul.  19(«,  198).  Denham  and  Wood- 
house  (Chem.  Soc.  Trans.  1913,  103,  1861)  have 
also  studied  this  reaction,  which,  however,  is  not 
of  industrial  interest.  Sulphuryl  chloride,  on  the 
other  hand,  either  as  such  or  in  the  nascent 
state,  ia  of  considerable  importance,  since  it  is 
easily  prepared  and  can  be  utUiaed  to  lull 
advantage  according  to  the  equation 

4CH,C00Na-fS0,a, 

=2(CH,CO),0+2Naa+NA^04 

The  Farbenfab.  vorm.  F.  Bayer  und  Co. 
(Eng.  Pat.  21560, 1900)  treat  dry  sodium  acetate 
with  a  mixture  of  gaseous  chlorine  and  sulphur 
dioxide  at  about  20^  C.  in  a  closed  vessel ;  to 
avoid  chlorination  it  is  important  that  the 
sulphur  dioxide  be  always  present  in  slight  excess. 
According  to  Farbw.  vorm.  Meister,  Lucius  and 
Bruning  (Ger.  Pat.  210805,  1907),  sulphur 
dioxide  forms  a  solid  addition  product  with 
sodium  acetate,  which*  is  readily  decomposed 
by  chlorine  with  the  production  of  acetyl 
chloride  or  acetic  anhydnde,  according  to  the 
proportions  of  sodium  acetate  used ;  the 
reaction  may  be  controlled  by  mixing  the  solid 
addition  compound  with  an  anhydrous  inorganic 
salt  or  with  sand.  The  Badische  Co.  prepare 
liquid  sulphuryl  chloride  by  mixing  the  two 
liquefied  gases  in  a  special  vessel  in  presence 
of  a  catalyst  such  as  camphor  or  glacial  acetic 
acid  (Eng.  Pat.  24255, 1902).  Glacial  aoeUc  acid 
and  acetic  anhydride,  being  excellent  solvents 
for  sulphur  dioxide  gas,  are  capable  of  acting  as 
catalysers  for  its  combination  with  chlorine 
gas,  and  the  reaction  proceeds  quite  smoothly 
without  the  formation  of  chloroacetic  acicu 
provided  the  temperature  be  kept  within 
moderate  limits  ana  local  excess  of  chlorine  be 
avoided.  Thus  in  the  process  of  the  Akt.  Ges. 
fiir  Anilin  fabr.,  according  to  Ger.  Pat  226218, 
1909,  sulphuryl  chloride  is  prepared  by  passing 
i  mixture  of  sulphur  dioxide  and  chlorine  in 
equivalent  proportions  into  acetic  anhydride 
and  separating  the  product  by  fractional  dis- 
tillation ;  the  yield  is  nearly  quantitative.  It 
is,  however,  by  no  means  necessary  to  isolate  the 
sulphuryl  chloride  as  such,  and  the  same  com- 
pany, according  to  Eng.  Pat.  23924,  1910, 
employ  acetic  anhydride  both  as  an  absorbing 
agent  for  the  gases  and  as  a  diluting  agent  for 
the  subsequent  reaction  with  sodium  acetate. 
For  instance,  256  parts  of  sulphur  dioxide  and 
284  parts  of  chlorine  by  weight  are  absorbed 
in  100  of  acetic  anhydride  and  this  solution  is 


ACETIC  ANHYDRIDE. 


29 


miiced,  while  cooling,  with  312  parts  of  sodium 
acetate :  the  mixture  is  stirred  and  when  the 
reaction  ia  complete,  the  anhydride  is  distilled  off. 

The  above  summary  oi  methods  based  on 
the  use  of  chloro  and  ozychloro  compounds  of 
sulphur  covers  the  majority  of  the  industrial 
processes  successfully  practised  at  the  present 
time.  Thev  may  all  be  classed  t<^ether  in  one 
group,  in  that  they  may  be  conceived  to  yield 
acetyl  diloride  as  an  intermediate  product,  and 
their  mechanism  depends  on  the  intervention 
of  the  chlorine  ion.  To  another  group  belong 
processes  based  on  the  decomposition  of  sodium 
acetate  with  a  strong  mineral  anhydride,  such  as 
sulphuric  anhydride.  Before  paasinff  to  this 
second  group  certain  methods  of  the  first  group 
must  be  mentioned,  depending  on  the  use  of 
sulphuric  anhydride  in  conjunction  with  chlorine 
as  a  possible  mtermediary. 

Gkloroeulphonio  acid  SOjHCl  can  react 
with  sodium  acetate  to  produce  acetyl  chloride 
or  acetic  anhydride,  but  only  under  disadvan- 
tageous conditioni  owing  to  the  presence  of  the 
hydracid  which  liberates  acetic  acid.  The 
Badische  Co.  (Eng.  Pat.  24255,  1902)  proposed 
to  avoid  this  difficulty  by  the  use  of  scxlium 
chlorosulphonate,  obtainea  by  the  action  of 
chlorosulphonio  add  on  sodium  chloride :  150 
parts  of  sodium  chlorosulphonate  are  heated 
with  170  parte  of  sodium  acetate  at  70^  C,  and 
the  anhydride  produced  is  distilled  off.  The 
equation  may  be  written 

NaS0,a-f-2CH,C00Na 

=(CH,CO),0+Naa+NaJ304 

If  half  the  quantity  of  sodium  acetate  be  used* 
acetyl  chloride  is  produced.  A  similar  process 
in  a  simplified  form  has  been  devised  by  H. 
Dreyfus  (Eng.  Pat.  17920,  1915),  who  uses  a 
compound  formed  by  the  direct  absorption  of 
sulpnuric  anhydride  by  sodium  chloride.  In 
these  reactions,  the  sodium  chloride  most 
probably  does  not  serve  merely  as  a  vehicle  for 
the  absorption  of  the  sulphunc  anhydride,  but 
may  be  assumed  to  play  a  part  in  the  reaction 
through  the  intermediate  formation  of  pyro- 
Bulphuryl  chloride  C1S0,-0S0|C1,  thus : 

3NaSO,a=8,0.a,4-Na,804+NaCa 
Si05a.+eCH,C00Na 

=3(CH,CO),0+2Na,S04+2Naa 

PyrosuldiuTyl  chloride  is  formed  together  with 
carbonyl  chloride  by  the  action  of  sulphuric 
anhydride  on  carbon  tetrachloride.  Both  pro- 
ducts are  capable  of  reactinff  with  sodium  acetate 
to  produce  acetic  anhydride,  and  Beatty  (Eng. 
Pat.  18823,  1912)  has  proposed  to  utilise  this 
reaction,  but  the  process  hardly  appears  suitable 
for  commercial  application. 

Methods  ci  the  second  group  dependms  on 
the  direot  action  of  inorganic  anhydrides  without 
the  intervention  of  chlorine  have  been  far  less 
widely  developed,  because  secondary  reactions 
which  destroy  the  acetic  anhydride  very  readily 
occur.  A  method  for  the  direct  application  of 
sulphuric  anhydride  was  patented  by  the 
Fabriek  van  Chem.  Prod  of  Schiedam,  HoUand 
(Eng.  Pats.  12130  and  12042,  1913),  and  further 
described  by  Van  Peski  (Chem.  Soc.  Abst.  1914, 
i.  653),  in  which  use  is  made  of  an  addition 
eompound  of  glacial  acetic  acid  with  sulphuric 
anhydride  and  its  reaction  with  sodium  a  etate. 


The  method  is  attended  by  certain  technical 
drawbacks,  the  operations  have  to  be  carried 
out  at  a  very  low  temperature,  and  it  is  impossible 
to  prepare  acetic  anhydride  of  high  strength 
owing  to  the  use  of  acetic  acid  as  a  vehicle. 
According  to  a  process  patented  by  H.  Dreyfus 
(Eng.  Pat.  17920,  1915)  sulphuric  anhydride  is 
abs^bed  by  sodium  sulphate  to  form  a  solid 
addition  compound  which  appears  to  be  different 
from  ordinary  sodium  pyrosulphate :  800  kilos 
of  sulphuric  anhydride  are  added  with  constant 
stirring  to  16(X)  kilos  of  powdered  anhydrous 
sodium  sulphate,  and  tne  product,  when 
thoroughly  cooled,  is  added  to  1640  kilos  of 
sodium  '  acetate  suspended  in  16(X)  kilos  of 
acetic  anhydride,  the  mixture  being  constantly 
stirred  and  cooled  with  water.  The  reaction 
is  completed  by  heatmg  at  60°-70'''C. 

The  above  account  sufficiently  summarises 
the  principal  processes  which  are  of  industrial 
importance.  There  are  several  others  of  poten- 
tial interest  and  some  only  of  academic  import- 
ance. An  excellent  review  of  the  subject  is 
contained  .in  a  paper  by  Hewitt  and  Lumsden 
(J.  Soc.  Chem.  Ind.  1916,  210).  Among  the 
proposed  dehydrating  agents  of  minor  import- 
ance may  be  mentioned :  Silicon  tetrafluoride, 
which  may  be  regenerated  by  heating  the  residue 
with  sand  and  sulphuric  acid  (Sommer,  Fr.  Pat. 
354742,  1905);  Nitric  anhydride  (Mulier, 
Fr.  Pat.  468963;  1914);  p-Toluenesulphochlo- 
ride,  a  by-product  of  the  manufacture  of  saccharin 
(von  Heyden,  Ger.  Pat.  123052,  1901). 

Recent  research  has  been  directed  to  the 
synthetic  preparation  of  acetic  anhydride  from 
acetylene  and  acetaldehyde,  for  instuice,  accord- 
ing to  Fr.  Pats.  420346  and  442738,  by  the  action 
of  chlorine  or  chlorous  anhydride.  An  interesting 
method  is  based  on  the  hydration  of  acetylene 
to  aldehyde  in  presence  of  a  mereuric  salt  at 
the  expense  of  the  dehydration  of  acetic  acid 
(Boiteau,  Fr.  Pats.  474828  and  475853),  with 
production  of  ethylidene  diacetate,  which  yields 
acetic  anhydride  and  acetaldehyde  on  distillation 
(Eng.  Pats.  23190,  1914;  110906,  1917;  and 
112765,  1917). 

The  chemical  engineering  of  the  manufacture 
of  acetic  anhydride  presents  no  unusual  problems. 
Ample  cooling,  power  must  be  provided  to  take 
up  the  considerable  amount  of  heat  produced 
during  the  mixing  of  the  reagents.  Powerful 
and  effective  stirring  eear  is  necessary  both 
in'  the  mixing  and  the  distilling  plants  to 
deal  with  the  masses  of  semi-solla  and  finally 
solid  materials  which  result  from  the  reaction. 
Access  of  moist  air  is  the  principal  source  of 
loss,  since  1  part  of  water  will  destroy  5*7  parts 
of  anhydride. 

Crude  acetic  anhydride  is  purified  and  freed 
from  mineral  acids  and  sulphur  compounds  by 
redistillation  under  reduced  pressure  in  presence 
of  sodium  acetate  and  a  metallic  oxide,  e.g, 
copper  oxide,  which  yields  an  insoluble  sulphide. 
Commereially  pure  acetic  anhydride  contains 
80  95  p.c.  of  anhydride,  the  remainder  being 
acetic  acid.  A  richer  product  for  laboratory 
purposes  may  be  prepared  by  fractional  dis- 
tillation. 

Physical  ConManis. — The  properties  of  pure 
acetic  anhydride  have  been  studied  by  Orton 
and  Jones  (Chem.  Soc.  Trans.  1912,  101,  1720). 
The  pure  compound  boils  at  139-5*'  C.  at  760 


so 


ACETTNS. 


mm.  pressure,  and  has  sp.gr.  1*0876  at  157^^  ^^ 
and  10820  at  2074^  G.  The  commercial 
anhydride  containing  a  little  acetic  acid  boils  at 
about  138"*  C.  The  specific  heat  is  0*434,  and 
the  latent  heat  of  vaporisation  at  137°  is  66*1 
Cals.  per  kilo  (Berthelot).  The  heat  of  hydra- 
tion per  ffrm.-mol.  to  form  2  mols.  of  acetic  acid 
(liquid)  IS  13*1  Cals.  The  refractive  index  for 
the  ray  D  at  20''  C.  is  1*39038,  and  for  the  ray 
Hy  is  1*39927  (Landolt). 

Chemical  Properties. — ^Acetic  anhydride  is  not 
immediately  hydrolysed  on  shaking  with  cold 
water,  and  at  low  temperatures  anhydride  and 
water  or  aqueous  acetic  acid  may  remain  in 
contact  with  each  other  for  a  considerable  time. 
At  20°  G.  and  over  the  hydrolysis  proceeds 
rapidly,  and  the  temperature  rises  very  con- 
sioerably.  The  hydration  is  accelerated  by  a 
trace  of  sulphuric  acid«  According  to  Orton 
and  Jones  (2.c.),  100  grams  of  pure  acetic  anhy- 
dride dissolve  about  2*7  grams  of  water  at  15°  G., 
but  the  solvent  power  is  considerably  increased 
by  the  presence  of  small  quantities  of  acetic 
acid.  Lumi^  and  Barbier  (Bl.  1906,  35,  625) 
have  studied  the  stability  of  solutions  of  acetic 
anhydride  in  water  and  alcohol  at  15°  and  0°  G. ; 
100  parts  of  cold  water  dissolve  12  of  acetic 
anhydride  on  shakinff. 

When  mixed  with  concentrated  sulphuric 
acid  at  0°  G.  acetic  anhydride  forms  an  addition 
compound,  acetylsulphuric  aAd,  which  is  a 
viscous  syrupy  liquia ;  if  the  temperature  is 
allowed  to  rise  this  changes  to  the  isomeric 
sulphoacetic  acid  HSO,GHs*GOOH,  and  brown 
condensation  products  are  also  formed  (Stillich, 
Ber.  1905,  1241).  With  concentrated  nitric  acid 
at  a  low  temperature,  acetic  anhydride  gives  a 
compound  C4H9NO7,  which  is  described  as 
diacetylorthonitric  acid  (Pic*et  and  Genequand, 
Ber.  1902,  2526),  and  with  nitric  anhydride  it 
gives  acetyl  nitrate  G2H,0,N0,  (Pictet  and 
Khotinsky,  Gompt.  rend.  1907, 144,  210).  These 
substances  react  generally  with  organic  hydroxyl 
compounds  as  nitrating  agents,  more  rarely  as 
acetylating  agents.  Acetic  anhydride  dissolves 
boric  anhydride  slowly,  boric  acid  rapidly,  on 
heating,  giving  a  mixed  boric  acetic  anhydride 
B(OOCGHa)., m.p.  121° C.  (Pictet and Geleznoff, 
Ber.  1903,  2219).  This  substance  may  be  used 
for  the  preparation  of  neutral  boric  esters  bv 
warming  with  idcohols  and  phenols.  With 
absolute  formic  acid  at  a  temperature  not 
exceeding  50°  G.,  acetic  anhydride  combines  to 
give  formyl  acetic  anhydride  which  distils  with 
decomposition  at  105°-120°  G.  This  com- 
pound generally  yields  formic  esters  with 
alcohols  and  formyl  derivatives  with  amines 
(B^hal,  Bl.  1900,  24,  745;  Eng.  Pat.  12157, 
1899). 

Acetic  anhydride  is  employed  for  the  manu- 
facture of  cellulose  acetate,  acetyLsalicylic  acid 
(aspirin),  and  diacetylmorphine  (heroin),  also  in 
the  dyeetuffs  and  pharmaceutical  industries  ;  it 
is  la»ely  employed  in  the  laboratory  for  the 

?[uantitative  estimation  of  hydroxyl  groups  and 
or  the  preparation  of  acetyl  derivatives  of 
bases.  With  aldehyde  croups  it  reacts,  forming 
the  diacetates  of  ortholdehydes 

HGHO  -^  R*G(OH),  -^  R*C(OOCCH,), 

-ih  are  not  very  stable. 

inalysis, — Gommeroial     acetic      anhydride 


should  be  substantially  free  from  sulphnr  and 
phosphorus  compounds,  chlorides  ana  chloro- 
acetic  acids.  Copper  from  the  distillation  plant 
and  higher  homologues,  such  as  propionic  and 
butyric  acids,  may  be  objectionable  for  phar- 
maceutical or  analytical  purposes ;  these  may 
be  removed  by  careful  fractionation.  The 
valuation  of  purified  acetic  anhydride  is  per- 
formed by  simple  titration  of  the  total  acidity 
as  acetic 'acid  and  calculation  of  the  excess  of 
acidity  in  terms  of  acetic  anhydride.  About 
5  grams  of  the  sample  is  accurately  weighed  in  a 
small  weighing  tube  which  is  then  dropped  into 
100  c.c.  of  A/1 -sodium  hydroxide.  Wnen  the 
anhydride  has  completely  disappeared,  the 
excess  of  alkali  is  titrated  back  with  N/lO-SLcid 
in  presence  of  phenolphthalein.  If  p  is  the 
weight  of  sample  taken,  and  q  its  acidity  as 
acetic  acid,  the  weight  of  anhydride  present  is 
5-6641  (q—p).  The  success  of  this  method 
depends  entirely  on  the  accuracy  of  the  measuring 
vessels  and  the  standardisation  of  the  solutions. 
An  error  of  0*1  c.c.  of  ^/1-soda  involves  an  error 
of  0*7  p.c.  in  the  anhydride  result,  and  the 
greatest  care  must  be  exercised  in  the  calibration 
of  the  burettes ;  it  is  necessary  also  to  apply  a 
correction  for  the  change  in  volume  of  the  normal 
solution  at  temperatures  different  from  that  at 
which  it  was  standardised.  The  method  of 
Menschutkin  and  Vasilieff  is  based  on  the  forma- 
tion of  acetanilide  from  aniline  at  a  moderate  * 
temperature;  it  does  not  ffive  satisfactory 
results  in  its  original  form.  For  a  risunU  of 
the  various  methods  and  an  improved  modifica- 
tion of  the  aniline  method,  see  Radcliffe  and 
Medofski,  J.  Soc.  Ghem.  Ind.  1917,  628. 
There  is  no  simple  and  accurate  method  for  the 
estimation  of  higher  homologues  in  presence  of 
large  proportions  of  acetic  acid ;  besides  the 
standard  analytical  text-books,  the  followinc 
references  may  be  consulted:  Muspratt,  J. 
Soc.  Ghem.  Ind.  1900,  204;  Langheld  and 
Zeileis,  Ber.  1913,  1171 ;  Crowell,  J.  Amer. 
Chem.  Soc.  1918,  413. 

w*  !•  B« 

ACETINS.  The  acetins  are  the  acetyl  deriva- 
tives of  glycerol,  or  glycerol  acetates.  Five  of 
these  are  theoretically  possible,  two  mono-»  two 
di-,  and  one  tri-  derivative,  aooordinff  to  the 
number  and  position  of  the  hydiozyl  groups 
attacked  by  the  acetic  acid.  Only  tuee  of 
these  compounds  have  been  prepared  ao  far, 
one  in  each  class,  and  the  positions  which  the 
acetyl  groups  take  up  in  the  mono-  and  di-  deri- 
vatives does  not  appear  to  be  experimentally 
proved,  though  they  are  probably  terminal. 
Commercial  acetin  is  a  mixture  of  all  three 
compounds  with  other  products. 

The  following  method  for  the  preparation  of 
mono-,  di-,  and  tri-acetin  has  been  described  by 
A.  a  Geitel  (J.  pr.  Ghem.  1897.  [ii]  55,  417):— 

200  grams  of  dry  glycerol  are  heated  with 
500  grams  of  glacial  acetic  acid  for  8  hours^  and 
the  acetic  acidi  and  water  distilled  off  under  re- 
duced pressure.  A  further  quantity  of  150  grama 
acid  is  then  added,  and  the  heating  continued  for 
16  hours.  Triacetin  is  isolated  from  the  product 
by  diluting  with  water  and  extracting  with  ether, 
and  is  a  colourless  liquid,  dissolving  in  water  to 
the  extent  of  about  7  p.c.  at  16*.  It  has  a  sp.gr. 
1*1605  at  16*  and  distils  without  decomposition 
at  1 72*-172-50/40  mm.   Diacetin  is  obUined  from 


ACETOACETTC  ACID. 


81 


tli«  mnainiiig  solution  by  fmctionatiiig  (after 
eonoentration)  under  a  pressure  of  40  mm.,  when 
it  oomes  over  between  i75*-176*.  It  is  a  soluble 
oolouiiess  liquid  with  sp.gr.  11769  at  16*.  In 
Older  to  isolate  the  monoacetin  formed  in  the 
reaction  the  aqueous  solution  after  removal  of 
the  ^aoetin  is  extracted  for  8  hours  with  ether 
at  34*-35^  in  an  extracting  apparatus  for  liquids ; 
the  later  extiaots  are  oollected  separately,  diluted 
with  an  equal  volume  of  water,  and,  after  bein£ 
extracted  with  hot  benzene,  are  concentrated. 
The  monaoetin  thus  formed  is  a  thick  syrup  of 
sp.gr.  1-2212  at  16*.  By  prolonging  the  ether 
extraction  still  further  monaceiyldiglycerQl 
C,H,(OH),-OG,Hs(OAc)*OH  may  be  obtamed ; 
it  is  a  oolonrless  liquid  of  sp.gr.  1*2323  at  16*. 
Diatdyldiglyeide  may  also  oe  separated  from 
the  monaoetin  by  fractionation,  and  triacetyl- 
diglyceni  is  also  formed. 

Comiii«reiaI  Aeetin  ('  Acdine  *)  is  prepared  by 
heating  in  an  oil-bath  a  mixture  of  60  parts  of 
elyoerol  and  82  pa^  of  glacial  acetic  acid  for 
12-16  hours  at  120*,  and  gradually  raising  the 
temperature  to  160*  to  en>el  the  excess  of  acetic 
a<Hd.  The  product  is  a  thick  liquid  smelling  of 
acetic  aoid  and  varying  in  colour  from  light 
y^Uow  to  dark  brown,  according  to  the  purity 
ot  the  glyoerol  used. 

The  value  of  the  product  depends  upon  the 
extent  to  which  combination  has  taken  place, 
and  this  is  determined  by  observing  the  specific 
gravity  and  estimatiuff  the  free  and  combined 
aoetao  add*  The  density  varies  between  1*1608 
and  l-1896f  bein^  lowest  when  the  free  acetic 
add  is  present  m  largest  amount.  The  free 
and  combined  acetic  acid  are  determined  as 
followB :  60  grams  of  '  aoetin  *  are  diluted  with 
water  to  600  o.o.  The  free  acid  in  60  c.o.  of  this 
solution  is  determined  by  titration  with  normal 
caustic  soda,  using  phenolphthalein  as  indicator. 
15  CO.  of  normal  caustic  soda  are  added  to  10  c.c. 
of  tile  aeetin  solution,  and  the  combined  acetic 
acid  liberated  by  hydrolysis  by  boiling  for  five 
minntesL  The  excess  of  caustic  soda  remaining 
is  a  measoxe  of  the  total  acid  present ;  and  the 
amount  of  combined  acid  is  found  by  subtract- 
ing bom  the  amount  of  caustic  soda  used  up  in 
the  hydiolysis  the  quantity  accounted  for  by 
the  free  acid.  The  follo^iiur  table  (Kopp  and 
Grandmougin,  BulL  Soc.  Ind.  Mulhouse,  1894, 
112)  shows  the  results  of  typical  analyses : — 


Ko. 

Density 

Add 
free 

Add 
couibined 

Remarks 

1 

2 
3 

11774 

1-1896 
M608 

p.c. 
9*2 

6-98 
23-0 

p.c. 
46-0 

4S6-7 
43-6 

A  medium  qual 

ity  sample 
A  good  sample 
Poor  sample. 

Aoeiin  is  used  as  a  solvent  for  basic  colouring 
matteis,  such  as  Induline  and  Perkin's  violet. 
They  aie  dissolved  by  being  heated  together  for 
about  two  h6un,  cooling,  and  filtering  through 
a  silk  filter.  Aeetin  is  to  be  preferrea  to  ethyl 
and  methyl  tartaric  acids  as  a  solvent,  as  acetic 
acid  is  less  injurious  to  the  fibres  than  tartaric 
acid. 

Halocai  deri?atlvM  ot  tbe  Aeetlns. 
a7-iihroiiio>/9-aeetylg]yeerol  (CH|Br),CH-OAc 


I 


is  obtained  by  the  prolonged  action  of  hy- 
drogen bromide  on  tnaoetin,  or  by  heating  the 
mixture  to  100*  in  sealed  tubes;  it  boib  at 
ISOMSS^  (40  mm.)  and  has  sp.gr.  1*6880  at  16*. 
It  hasun  agreeable  aromatic  odour,  is  slightly 
soluble  in  water,  and  readily  soluble  in  alcohol 
and  ether.  It  yields  Mopropyl  alcohol  on  re- 
duction. 

a-bromo-i37-diacetylgIyeerol  CH,BrCH(OAc). 
CH,*OAc  is  produced  by  the  prolonged  action  of 
hydrogen  bromide  dissolved  in  acetic  acid  on 
triacetin  at  0*  in  the  dark.  It  boils  at  160*-166° 
(40  mm.),  and  has  sp.gr.  1*2906  at  16**.  It  yields 
Mopropylene  glycol  on  reduction. 

oy-dlehloro-iS-aeetylglyeerol  (CH,a)2CHOAo 
repared  similarly  to  the  bromine  compound, 
oils  at   116*-120*  (40  mm.),  and  has  sp.gr. 
M618  at  16*. 

a-eUoro-iSy-diaeetylglyeerol  CH,a*G!H(OAc) 
dHj-OAc  boils  at  146*-160*  (40  mm.),  and  has 
Bp.gr.  1-1307  at  16*. 

ai3-diehloromonoae6tin  CH,a*CHaCH,*OAc 
is  prepared  by  the  action  of  acetic  anhydride 
on  chlorinated  allyl  alcohol,  and  has  sp.gr. 
1-1677  at  16*,  but  in«ll  other  respects  is  identical 
with  the  ay-dichloro-  compound. 

a-iododiacetlil  CHJ-CH(OAc)-GH,-OAo  k 
obtained  b^  the  action  of  sodium  iodide  on  the 
corresponding  chloro-  compound.  It  is  an  un- 
stable oil  having  a  sp.gr.  1.4584  at  16*. 

J.A.P 

ACETNAPHTHALIDE  DISULPHONIC  ACID 

V.  NilPHTHi^LSNB. 

ACETOACETIC  ACID  GH,C0C;H, GO.H  ia 
a  thick  acid  liquid  miscible  with  water  in  all 

Eroportions.  It  is  prepared  from  its  ethyl  ester 
y  leaving  4}  parts  of  ester  in  contact  with  2-1 
parts  of  potash  and  80  parts  of  water  for  24 
hours  and  acidifying  with  sulphuric  acid.  It  is 
extracted  from  the  solution  with  ether. 

It  is  very  unstable  and  readily  decomposes 
below  100*  into  acetone  and  carbon  dioxide.  It 
yields  a  violet  colouration  with  ferric  chloride 
and  forms  ill-characterised  amorphous  salts, 
BaA2,2H,0  and  ChiA2,2H,0,  when  treated  with 
the  corresponding  carbonate. 

Acetoacetio  acid  appears  in  the  urine  of 
diabetic  patients,  and  indicates  defective  oxida- 
tion. Its  detection  and  estimation  have  been 
the  subject  of  much  controversy  and  investiga- 
tion. Arnold  (CSiem.  Zentr.  1899,  ii.  146)  makes 
use  of  a  colour  reaction  with  acetophenone,  which 
will  show  1  part  in  10,000,  but  is  afifected  to 
some  extent  by  the  presence  of  acetone.  Biegler 
(Chem.  Soc.  Abetr.  1903,  ii.  112)  emplojrs  the 
colour  produced  by  the  addition  of  sulphuric 
and  iodic  acids,  which  he  states  to  be  unaffected 
by  the  presence  of  sugars,  leucine,  tyrosine,  or 
acetone.  Bondi  (Chem.  Zentr.  1906,  L  707) 
recommends  the  use  of  a  solution  of  iodine  and 
the  detection  of  acetoacetic  acid  by  the  cha- 
racteristic smell  of  the  iodacetone  produced ; 
but  Lindemann  {ibicL  717)  says  that  this  smell 
is  not  characteristic  of  acetoacetio  acid.  Mayer 
adds  the  urine  to  a  very  dilute  solution  of  ferric 
chloride  in  brine^  when,  in  the  presence  of 
acetoacetio  acid,  a  claret-red  ring  is  formed. 
When  the  red  colour  is  only  just  visible,  the 
liquid  may  be  assumed  to  contain  0*01  p.c.  of 
the  acid.  A  blank  test  performed  after  boiling 
the  acid  for  five  minutes  should  give  no  colour 
(Chem.  Zentr.  1906,  i.  406). 


ACETOACErriO  ACID. 


Appti^liont   M    Sy»lhe*u.—Bj  i 


amoaat  of  ftcetone  nnd  »cetoftcetio  acid  present 
nith  fair  accuracj,  and  the  acetone  may  t» 
eetimated  separately  nith  considerable  exacti- 
tude bf  the  method  of  Folin  (J.  Biol.  Chem. 
1907,  3,  177),  in  which  it  is  aspirated  oat  of  the 
liquid  into  iodine  and  potash,  and  the  retnlting 
iodoform  weighed. 

MMgl  acOoaaiaU  CH,<}0-CH,<X),Me  is 
prepared  by  heating  together  methyl  acetate  and 
■odium  under  a  reflux  condenser   and   subse- 

Jaeatlj  dietilline  in  a  streaui  of  carbon  dioxide. 
t  is  a  colourless  liquid,  easily  miscible  with  water, 
which  boils  at  16B°-I70°  and  has  a  sp.^.  1-0917 
at  4' ;  10809  at  16°  ;  and  107M  at  25°.  It  is 
decooipoBed  on  boiling  with  water  into  carbon 
dioxide,  aoetone,  and  methyl  alcohol.  With 
ferric  chloride  it  yields  a  deep  te^  colouration, 

Elk'il  aulliarrlatt  (aefloifetie  'tUr)  CH,-CO' 
CH,-CO,Et  and  CH.QOH)  :  CHCO.Et,  was 
discoTered  byOeuther  in  1863. and  independently 
by  FnmUand  and  Dnppa  in  I8ftA.  It  is  a 
colourless,  slightly  sympy  liquid,  with  a  pleasant 
odour.  It  boils  at  180e°-181'2°/764  mm. 
(Briibl)j  180°-lS0'3°/7M-6  mm.  (8chiS) ; 
71712-0  mm.  and  100'2°/80  mm.  (Eafalbanm). 
It  lias  a  specific  gravity  1-0486  0°/4°  (Schiff) ; 
I -02B2  20°/4°  (Schaoin).  The  deiuity  gradually 
chaiuea  on  keeping  [v.  in/ro). 

Ethyl  acetoscetate  is  prepared  by  the  aotion 
of  sodium  on  ethyl  acetate.  Tba  followine 
details  ol  the  method  are  given  by  Conrad 
(Annalen,  1B6,  2U):  100  grams  of  sodium  are 
added  to  1000  grams  of  pure  ethyl  acetate,  and  | 
after  the  reaction  has  moderated  considerably,  , 
the  whole  is  heated  on  a  water-bath  under  ■  | 
reflux  condenser  for  2-2}  hours  until  alt  the 
sodium  has  disappeared.     To  the  warm  mass 

■KA J  of  JO  _  (^  aootio  acid  are  added,  and  ■ 

ling  600  c.c  of  water.  The  whole  is  : 
ton,  and  the  npper  layer  separated,  , 
riOi  a  little  water,  and  fractionated.  1 
tions  100°-130°,  IM'-ieo",  186°-175*, 
",  I85"-200°  are  ooUectod  separately 
actionated  twice.  The  yield  is  17S 
product  boiling  at  17G°'1B5^  and  from 
ion  boiling  below  100°.  360-400  grams 
icef afe  may  t>e  recoverfl  after  remo»fiw 
lol  by  salting  out.  IMails  of  a  method 
ration  on  the  large  scale  are  given  by 
In  Chem.  Zeit.  1914,  3R.  6SG. 
1  acetoacetate  is  neutral  to  Ltmus,  bat 
ilts  with  sodium,  copper,  and  other 
y  replaoement  of  hydrogen.  Only  one 
hydrogen  oan  be  repla^d  by  sodium, 
e  sodium  in  the  resulting  oompoand  is 
hy  an  alkyl  radicle  a  second  hydrogen 
y  then  be  replaced.  Ferric  chloride  pro- 
'iolet  colouration.  With  (odIum  bisul- 
nystalline  addition  product  C,H,gO^ 
is  formed.  On  heating  Cor  a  long  time, 
;the  vapour  through  a  hot  tube,  acetone, 
dehydraoetio  acid,  and,  methane  are 
Sodium  amalgam  reduces  it  to  B-hydroxy 
Old  CH.CHfOH)  CH,  CO.H.  It  oon- 
ith  hydroxylamine,  but  doe.s  not  form 
■,  aa  internal  eondensation  takes  plaoe, 
in  the  production  of  meths/l  ito- 
CH,-CCH,-CO  which  is  converted  by 

N 6 

ito  salts  of  d-oxlminobutyric  acid. 


>tty  acidg  may  be  obtained  bv  dissolving 
sodium  (I  atom)  in  absolute  alcohol,  adding 
ethyl  acetoaoetate  (1  moL)  followed  by  an 
alkyl  ballon  oompound  (1  moL).  The  resisting 
alkyl  derivative  is  treated  with  strong  alkalis, 
when  the  molecule  is  hydrolyted  with  formation 
of  aoeti:  aoid  and  the  desired  alkyl  aaetie  acid. 
CH,-CO-CH,-CO,H  ->  CH,-C(ONa);CH-CO,Et 
-*  CH,CO-CHR-CO,Et    -*  CH,-Cq,H 

+  BCT.-CO^ 

If  the  bydraljsis  is  brought  about  bf  rf^iitt 
acidt    iostwd    of     concentrated     alkalis,    the 
molecule    b     diSerently      divided,    produoitig 
ketones. 
CH.-CO-CHR-CO.Et  -* 

OH.CO'CH.R  +  EtOH  +  COf 

Dialkyl  acetic  acids  and  ketones  may  be  pro- 
duced hy  introducing  a  second  alkyl  radicle  mto 
the  molecule  by  a  similar  process  after  the  first 
has  entered,  but  the  two  oannot  be  introduced 
together  in  one  operation. 

PyraxoUmu,  of  which  the  most  important 
industrially  is  antipyrine,  are  produced  by  the 
condensation  of  ethyl  acetoscetate  with  hydra- 
sines.  Antipyrin  (1-pfcenjI  2:  S-dimefAyl-B-fyra- 
lotone)  is  prepared  from  symmetrical  meUiyl 
phenylhydraime  and  elhyl  aoetoacetate  (v.  also 
PrRAZOLB  and  Antifyrink). 
PhNH  OEtCO 


McNH 


^CH 


I  yXni  +  EtOH  -1-  H,0- 
MeN  CMe 
QuinoIiMs  may  be  prepared  by  firtt  making 
the  anilide  of  ethyl  acetoaoetate  by  heating 
with  aniline  at  110°,  and  afterwards  heating 
this  product  with  concentrated  hydrochloric 
add.  CH,-CO-CH,-CO-NHPh  ohinges  into 
CH,-C(OH) :  CH-C(0H)  :  NPh.  and  re^y  con- 
denses to  \  hydroxy A'tntthylqainotint 


Pyridinu  [v.  also  Botib  on.)  sre  obtained  by 


lyl  dihydroeoUidine  dicarboxyl- 
ato  is  the  simplest  example: 
CO.EtCH         HOCHMe  HCCO.Et 

CH.-COH  HNH  HO-CCH, 

CHMe 

CO,EtC     C-CO.Et 

"*  CH,-C      C-CH, 

Pwronei.— Dehydraeptic    acid,    a-methyl    B- 


AOETOL. 


33 


acctylpyrone,    is    produced    on    heating    ethyl 
aoetoacetate  for  a  oonaiderable  time. 

Co&uHUiiion, — ^llie  oonBtitution  of  ethyl  aceto- 
acetate  and  its  sodinm  deriTativea  was  for  many 
years  a  subject  of  discussion  by  Frankland  and 
Duppa,  Genther,  Claisen,  Laar,  Wislicenus, 
Briihl,  Perkin,  and  others.  The  general  opinion 
is  that  ethyl  acetoacetate  consisto  of  a  mixture 
of  the  two  forms,  ketonio  CH8-C0-CH,-C0,Et, 
and enolio CH,C(OH) :  CH-CO jEt.  The  freshly 
prepared  substance  is  practicaUy  a  pure  ketone, 
but  on  keeping  it  changes  partially  into  the 
enolio  form,  and  when  equilibrium  is  reached 
about  10  p.c.  of  the  latter  in  present  at  ordinary' 
teniperatures.  The  rate  of  change  has  been 
studied  by  observing  the  change  of  viscosity. 
See  Dunstan  and  Mussel,  Ghem.  Soc.  Trans. 
1911,  99,  566.  The  sodium  compound  is  a 
derivative  of  the  enolic  form. 

Alkyl  derivatives  of  ethyl  aeetoaeetate. 

1.  Mono-mbaiituted  (dkyl  derivatives. 

Ethyl  methyhcetoaeekUeCH^CO'CHMeCO^Ei 
boils  at  186 -8%  and  has  sp.ffr.  1-009  at  6^ 
Prepared  from  methyl  iodide  and  sodium 
acetoacetate  (Geuther,  J.  1865,  303). 

Ethf^  eihylaeetoacetate  CH,COCHEtCO,£t 
boils  at  195''-196°,  and  has  8p.gr.  0*9834  at  16°.  It 
is  readily  decomposed  by  biyr^  or  alcoholic  pot- 
ash into  alcohol,  carbon  diozide  and  methyl  propyl 
ketone ;  and  by  dry  sodium  ethoxide  into  acetic 
and  butyric  esters  (Miller,  Annalen,  200,  281 ; 
Wedel,Annalen,210,100;  Frankland  and  Duppa, 
Annalen,  138, 215;  W]sIicenus,Annalen,  186, 187). 
Ethyl  propylaeetoaeetaUCHt'CO'CRFf^CO^Ui 
boils  at  208*-209%  and  has  sp.gr.  Oggi  a 
OV^**  It  is  prepared  by  adding  to  a  solution 
of  27  grams  of  sodium  in  270  grams  absolute 
alcohol,  152-7  grams  ethyl  acetoacetate,  followed 
gradually  by  ^  grams  propyl  iodide. 

Ethyl  iwpropylacetoaceiate  GH,C0-GHPr3 • 
CX),£t  boils  at  20r/758'4  mm.,  and  has  sp.gr. 
0*9806  at  0°. 

Eihyl  isobviylaeetoacetate  GH,-GO'CH(CH,- 
CHMe,)GO,Et  boils  at  217''-218*,  and  has  sp.gr. 
0-951  at  17*5^  (Rohn,  Annalen,  190, 306  ;  Minter, 
Ber.  1874,  501). 

Eihyl  isoamyUseetoacdaU  GH.*GOGH(GH, 
CH,*CHMe,)00,Et  boils  at  227*-228*  (Peters, 
Ber.  1887,  3322). 

Ethyl  amylaeetoacetate  CEt'CO'CH{C.B.iA 
OO.Et  boils  at  242''-244*  (Ponzk)  and  Prandi, 
Gazz.  chem.  itaL  28,  ii.  280). 

Ethyl  heptylacetoaeetaU  boib  at  271*-^273^  and 
has  Bp.gr.  0-9324  at  17-7^ 

Eihyl  odylautoaedate  boils  at  280*-282^  and 
has  sp-gr.  0-9354  at  18*-5/17-6". 

2.  Di-subsUtuted  alkyl  derivatives. 

Ethyl  dimethylaeetoacetate  GH,*GOGMe,' 
COjEt  boOs  at  184'',  and  has  sp.gr.  0*9913  at  16^ 

Ethyl  methylethylacetoacetaU  GH,-GO-GMeEt 
OOaEt  boils  at  198%  and  has  sp.gr.  0*947 
at  22»/17**5. 

Ethyl  meihylpropylaeetoacetate  GH,*GO'GMe 
PrGO.fIt  boils  at  214*,  and  has  sp.gr.  0-9575  at 

1774. 

Ethyl  diethylacetoacetate  GH,GOGEt,*COtEt 
boOa  at  218*",  and  has  sp.gr.  0*9738  at  20^. 

EthyldipropylacetoacetaUQHt'CO'CPTtCO  tEt 
boOs  at  236%  and  has  sp.gr.  0*9585  at  074°. 

Eihyl  dUsobmiylacetoaeetate  boils  at  250''-253% 
and  has  sp.gr.  0*947  at  10". 
Vol.  I.— r. 


Ethyl  diheptyUicfloat.^ta'e  boils  at  332°,  and 
has  8p.gr.  0*891  at  17-5717*6**. 

Ethyl  dioetylacetoacetaU  boils  at  264*  790  mm., 
340M42*  /760  mm. 

ACETOFORH.  Trade  name  for  a  combina- 
tion of  hexamethylenetetramine  and  aluminium 
aceto-citratc. 

ACETOL  (meihyl-ketol,  acetyl  earhinol,  or 
propanohn)  GH,(!()CH,OH  is  the  simplest  ketone 
alcohol.  It  is  obtained  by  saponification  of  the 
acetyl  carbinol  acetate  or  formate  produced 
on  condensing  chloro-acetone  with  potassium 
acetate  or  formate  (Henry,  Ber.  1872,  5,  966 ; 
W.  H.  Perkin,  Trans.  Ghem.  Soc.  1891,  59,  786 ; 
Nef,  Annalen,  1904,  335,  248).  For  the  purpose 
of  saponification  in  this  case  boiling  witii  methyl 
alcohol  containing  1-2  p.c.  hydrochloric  acid  is 
emploj^ed.  It  is  also  formed  in  the  biochemical 
oxidation  of  propylene  glycol  by  means  of  the 
sorbose  bacterium  or  by  myeoderma  aeeti,  in  the 
pyrochemical  decomposition  of  glycerol  (Nef, 
I.e.),  and  by  heating  a-bromopropionic  aldehyde 
with  a  methyl  alcoholic  solution  of  potassium  or 
sodium  formate  for  10-15  hours  (Nef,  ibid.  265). 
In  this  latter  preparation  the  metal  halide  is 
filtered  off  ana  tne  acetol  fractionated  twice 
under  diminished  pressure,  when  it  is  obtained 
perfectly  pure. 

Acetol  boils  at  54''  (18  mm.),  and  with 
slight  decomposition  at  147^  under  atmospheric 
pressure.  It  possesses  a  faint,  characteristic 
smell,  and  is  miscible  with  water.  It  readily 
forms  more  complex  condensation  products, 
especially  in  the  presence  of  traces  of  haloeen 
compounds ;  but  this  may  be  avoided  by  diluting 
it  with  its  own  volume  of  methyl  alcohol.  When 
passed  through  a  tube  heated  to  450^  it 
decomposes  into  aoetaldehyde  and  mdoform- 
aldehyde,  together  with  a  smiJl  quantity  of 
their  decomposition  products,  namely,  croton- 
aldehyde,  carbon  monoxide,  hydrogen,  kc. 

On  oxidation  with  mercuric  oxide,  silver 
oxide,  or  chromic  acid  in  the  presence  of  sul- 

Ehuric  acid  it  yields  formic  and  acetic  acids; 
ut  with  copper  oxide  in  alkaline  solution  it 
yields  lactic  add : 

GH,COCH,OH  ->  GH.COOHO 

H-HftO 

GH.CHOH-COOH 


+Hjp 


On  reduction  with  sodium  amalgam  in  aqueous 
solution,  acetone,  Mopropyl  alcohol,  and  pro- 
pylene glycol  are  produced ;  a  reaction  which 
suggests  that  in  aqueous  solution  acetol  has 
changed  into  the  tautomeric  form  : 

CHg— G— CH, 

h/Y 

The  behaviour  of  acetol  and  its  esters  to  the 
Grisnard  reagent  shows  that  they  exist  in  the 
carbonyl  form,  for  with  magnesium  ethyl  iodide, 

CH  OH 

amylene  glycol  q  jJ  >^<GH  OH  "  obtained, 

which  could  not  be  the  case  with  the  ethylene 
oxide  type  of  structure.  In  contact  with  solid 
caustic  alkali,  acetol  is  converted  into  dark  red 
tarry  matters,  with  simultaneous  development 
of  great  heat. 

Acetol-oximt  is  obtained  by  the  oxidation 
of  2-methyl-2-hydroxyaminopropane  di-ol-l*3 
(HONHKGHj)C(CHjOH),  with  mercuric  oxide 


34 


ACETOU 


(Pilots  and  Ruff,  Ber.  ,1807,  30»  1666,  3161). 
It  or3r8tallifle8  in  priBms,  melts  at  71°  C,  and 
is  eaoly  soluble  in  water. 
Acdci  semioofbaxone 

CH,0( : N-NHC0NH,)<5H,0H 

serves  as  the  best  means  of  identifying  acetol. 
It  melts  at  196''-200''  C,  is  yeiy  stable,  and  is 
only  yery  slightly  soluble  in  ether,  benzene,  and 
chloroform.  The  phenylhydrazone  melts  at 
lOe*"  C. ;  the  oaazone  at  163''-I54<'  G. 

The  name  '  Acetol '  is  also  given  to  a  pro- 
duct obtained  as  an  ester  of  ■alicylio  acid  by 
condenrinff  sodium  salicylate  with  monoohlor- 
aoetone  OH-C.H^-COOCHjCO'CH,.  Forms 
needles  from  solution  in  alcohol,  m.p.  71° ; 
sparingly  soluble  in  warm  water  (Eritsoh,  E.  P. 
3961,  1893 ;  J.  8oo.  Chem.  Ind.  1894,  274). 

ACETOMETER.  A  hydrometer  (graduated 
to  indicate  the  strength  of  commercial  acetic 
acid  according  to  its  cfensity. 

ACETOMORPHINE.  Syn.  for  diacetylmor- 
phlne.  Used  to  check  spasmodic  coughixig,  and 
m  lowering  reflex  irritability,  v.  Opium  and 
Opium  ^kaloids. 

ACETONE G,H,0 or CH,-COCH,.  Dimelhyl 
ketone,  A  product  of  the  destructive  distillation 
of  acetates ;  obtained  by  Liebis  from  lead  acetate 
(Annalen,  1,  226)  and  further  examined  by 
Dumas  (Ann.  Ghim.  Phys.  [2]  49,  208),  who 
first  determined  its  composition.  Acetone  is 
also  produced  in  the  dry  distillation  of  wood 
(VolcKel,  Annalen,  80,  310 ;  J.  Soc.  Chem.  Ind. 
16,  667,  722  ;  27,  798) ;  of  citric  acid  (Robiquet, 
B.  J.  18,  602) ;  of  sugar,  starch,  and  gums  with 
lime  (FiWy,  Annalen,  16,  279 ;  J.  £xs.  Chem. 
Ind.  21,  641,  1096).  Large  quantities  of  acetone 
are  now  produced  by  the  deetructive  distillation 
of  the  giant  kelp  of  the  Pacific  Coast;  the 
quantity  of  cut  kelp  averaged  above  24,000 
tons  a  month  in  1917.  By  oxidation  of  proteid 
substances  with  iron  salts  (Blumenthal  and 
Neubeig,  Chem.  Zentr.  1901,  i.  788 ;  Ingler, 
Beitr.  Ohem.  Phys.  Path.  1902,  i.  683),  and  by 
heating  dtric  acid  with  potassium  permanganate 
(P^an  de  St.  Gilles,  J.  1868,  686 ;  Sabbatani, 
Atti  AcadL  SoL  Torino,  1900,  36,  678) ;  and  by 
the  oxidation  of  isovaleric  acid  (Crossley  and 
Le  Sueur,  Chem.  Soc.  Trans.  1899, 166).  Acetone 
is  also  produced  by  the  Fembach  process,  in 
which  starch  from  maize  or  other  grain  is 
fermented  by  a  special  ferment  which  resolves 
the  carbohydrate  into  a  mixture  of  butyl 
alcohol  and  acetone. 

Prepomftcm. — 1.  Acetone  can  be  obtained 
by  distjlling  a  mixture  of  1  part  of  caustic  lime 
and  2  parts  of  crystallised  lead  aoetato  (Zcnse, 
Annalen,  33,  32) ;  but  is  usually  prepared  by 
the  dry  distillation  of  barium  acetate  at  a 
moderate  heat.  Calcium  aoetete  can  also  be 
employed,  but  the  temperature  required  is 
greater,  and  the  product  is  conteminated  with 
impurities,  such  as  dumasin,  an  isomeride  of 
mesityl  oxide  ;  but  according  to  Becker  (J.  Soc. 
Chem.  Ind.  26,  279)  a  lower  temperature  is 
required  if  the  calcium  salto  are  made  quite 
neutral  and  the  formation  of  free  lime  is  pre- 
vented by  the  introduction  of  a  stream  of  dry 
carbon  dioxide.  Bamberger  (Ber.  1910,  43, 
3617)  considers  that  the  formation  of  acetone 
consiste  first  in  the  formation  of  lime  and  acetic 
nhydride,  and  that  the  latter  is  decomposed  I 


into  acetone  and  carbon  dioxide.  It  has  been 
shown  (Freudenheim,  J.  Physical  Chem.  1918, 
22,  184)  that  when  acetone  is  heated  with  lime 
at  temperatures  ranging  up  to  630*',  a  species 
of '  cracking '  occurs,  wmch  resulto  in  the  forma- 
tion of  methane,  ethylene,  hydrogen,  carbon 
monoxide,  and  carbon  dioxide.  As  the  tem- 
perature is  raised  to  the  upper  limit  mentioned, 
the  amount  of  methane  increases  rapidly,  whilst 
that  of  hydrogen  is  diminished.  The  explanation 
put  forward  is  that  acetone  undergeos  (a)  a 
high  temperature  dissociation;  and  (6)  con- 
version into  keten,  which  thereafter  decom- 
poses: 

CH.CO-CH,    ->    CH,+CO-hC+H, 
GH.GO-CH,    ->    GH4-fCH,:C0 
2CH,:C0        -»    2CO+C,H4 

Magnesium  or  strontium  acetetes  can  also 
be  used.  Industrially,  acetone  can  be  pre- 
pared by  passing  the  vapour  of  acetic  acid  mto 
air-tight  vessels  heated  to  600°,  containing 
some  porous  substances  saturated  with  lime  or 
baryto  (J.  Soc.  Chem.  Ind.  18,  128,  824; 
Bauschlicker,  D.  R.  P.  81914) ;  also  by  passing 
a  continuous  current  of  pyroligneous  acid  over 
a  heated  aoetete  capable  of  torming  acetone 
(J.  Soc.  Chem.  Ind.  26,  634;  26,  1002;  27, 
277).  An  improved  method  is  also  described 
by  Wenghoffer  (D.  R.  P.  144328;  compare 
alBO  J.  Soc.  Chem.  Ind.  14,  987  ;  20,  1130 ;  22, 
297). 

According  to  Squibb  (J.  Soc.  Chem.  Ind. 
1896,  231 ;  J.  Amer.  Chem.  Soc.),  pure  acetone 
for  use  in  the  preparation  of  smokeless  powders 
can  be  obtained  oy  subjecting  acetetes  mixed 
with  an  excess  of  calcium  hydn>xi4e  to  destruc- 
tive distillation  and  to  the  action  of  superheated 
steam. 

2.  From  wood-spirit  acetone  can  be  separated 
by  distilling  over  calcium  chloride.  The' product 
ODteined  by  these  methods  can  readily  be  purified 
by  converting  the  acetone  into  ito  crystalline 
compound  with  acid  sodium  (or  potassium) 
sulpnite,  crystallising  this,  and  suDsequently 
distilling  with  aqueous  sodium  carbonate ;  the 
distillate  is  then  treated  with  concentrated 
calcium  chloride  solution  and  the  ethereal  layer 
rectified  over  solid  chloride.  According  to 
Conroy  (J.  Soc.  Chem.  Ind.  19,  206),  it  shoiud  be 

Jurified  by  distillation  over  sulphuric  acid  (Dolt, 
.  Soc.  Chem.  Ind.  27,  272),  whilst  Amoult 
(ibid,  27,  679)  recommends  treatment  with 
oxidising  agents. 

According  to  Shipsey  and  Werner  (Chem. 
Soc.  Trans.  1913,  103,  1266),  sodium  iodide 
forms  a  crystalline  compound  with  acetone 
NaI,3C,H,0,  which  easily  siyes  off  all  the 
acetone  on  gentle  warmins.  The  formation  of 
this  compound  can  be  used  for  the  preparation  ' 
of  pure  acetone  from  the  commercial  material. 
It  may  be  readily  prepared  by  dissolving 
anhydrous  sodium  iodiae  to  the  point  of  satura- 
tion in  the  hot  acetone,  and  allowing  the  solution 
to  cool  to  the  ordinary  temperature ;  if  the 
liquid  is  cooled  to  about  —8°  by  means  of  ice 
and  salt,  the  yield  of  crystals  is  larsely  increased. 

Acetone  has  been  prepared  synuieticaUy  from 
zinc  methyl  and  acetyl  chloride  (freund, 
Annalen,  118, 11).  It  occurs  in  the  urine,  blood, 
and  brain  of  calcium  diabetic  patients. 

Properties. — Acetone    is    a    limpid,    mobile 


ACETONE. 


liquid,  haying  an  ^reeable  odour  and  a  pepper- 
mint-like taste.  U  is  very  inflammable  and 
bums  with  a  white  smokeless  flame,  b.p.  56*3^ 
(B^gnault) ;  8p.gr.  08144  at 0%  0*79946  at  13-9'' 


and 
81858 
074*  (Thorpe  and  lEtodger) ;  8p.grro-81378  at 
074^  0-79706  at  1574**,  0-77986  at  3074'' 
(SapoBohniko£f,  J.  Russ.  Phys.  Chem.  80c.  28, 
229);  m.p.  —94-9''  (Ladenburg  and  Krugel, 
Ber.  32,  1821;  Formenti,  L'Orosi,  1900,  23, 
223).  Aoetotne  is  miscible  in  all  proportions 
with  water,  aloohol,  ether,  and  many  ethereal 
salts;  it  can  be  separated  from  its  aaueous 
•dution  by  the  addition  of  calcium  chloride, 
and  dissQlyes  many  fats  and  resins.  It  is 
also  an  excellent  solyent  for  acetylene  and 
tannins  (Trimble  and  Peacock,  Pharm.  J. 
63,  317).  Acetone  is  used  in  perfumery  and 
pharmacy;  in  the  manufacture  of  smokeless 
powders;  of  cordite  and  of  celluloid  articles 
(Marshal,  J.  Soa  Chem.  Ind.  23,  24,  645),  also  in 
the  preparation  of  iodoform  (Teeple,  J.  Amer. 
Chem.  80c.  26, 170 ;  Abbott,  J.  Phys.  Chem.  7, 
83) ;  of  chloroform  (Squibb,  tf.  Amer.  Chem.  Soc. 
1896, 231;  Omdorff  and  Jessel,  Amer.  Chem.  J. 
10,  363;  Dolt,  Lc,  271);  and  in  the  presence 
of  sodium  sulphite  it  can  be  used  as  a  good 
substitute  for  alkali  in  photographic  deyelopers 
(Lumidre  and  Segewetz,  Bull.  Soo.  ohim.  16,  [3] 
1164;  Hon.  Sci  1903,  267,  668;  Eichengrun, 
Zeitsch.  angew.  Chem.  1902,  1114).  When  its 
vapour  is  passed  through  a  red-hot  copper  tube, 
a  yery  small  proportion  of  tarry  products  con- 
taining naphthalene  is  obtained  together  with 
a  laige  yolnme  of  gas  haying  the  composition : 
carbon  monoxide,  39-23  p.c.;  methane,  37*68  p.c.; 
hydrogen,  17*64  p.c.;  ana  ethylene,  6*66  p.c.  (6ar- 
bier  and  Rouz,  Compt.  rend.  102,  1669).  De- 
hydrating agents  readily  act  on  acetone  and 
convert  it  into  condensation  products ;  thus, 
caustic  lime  converts  acetone  into  mesityl  oxide 
C«HioO  and  phorone  C9H14O  when  the  action  is 
allowed  to  continue  for  a  week  (Fittig,  Annalen, 
110,  32),  and,  together  with  smaller  proportions 
of  other  products,  these  two  compounds  are 
also  formed  when  it  is  saturated  with  hydrogen 
chloride  and  allowed  to  stand  for  8  to  14 
days  (Baeyer,  Annalen,  140,  297):  with  zinc 
chloride  terpene  condensation  products  are 
formed  (Raikow,  Ber.  30, 906).  Distillation  with 
concentrated  sulphuric  acid  converts  acetone 
into  mesitylene,  mesityl  oxide,  phorone  and 
Modurene  and  other  substances  (Omdorff  and 
Toung,  Amer.  Chem.  J.  16,  249).  A  similar 
result  is  obtained  when  it  is  heated  with  boron 
fluoride.  The  action  of  nitric  acid  and  nitric 
oxide  on  acetone  has  been  studied  by  Newbury 
and  Omdoff  (Amer.  Chem.  J.  12,  617),  Behrend 
and  SchmitsB  (Annalen,  277,  310).  Behrend  and 
Tryller  (Annalen,  283, 209),  Apetz  and  Hell  (Ber. 
27,  933),  Tranbe  (Annalen,  300,  81),  Mcintosh 
(Amer.  Chem.  Soc.  27,  1013) ;  of  hydrogen  per- 
oxide by  Baeyer  and  Villiger  (Ber.  32,  3626 ;  33, 
174,  868),  Pastureau  (Compt.  rsnd.  140,  1691), 
Wolffenstein  (Ber.  28,  2265);  of  thionyl  chloride 
by  Loth  and  fiiichaels  (Ber.  27,  2640) ;  and  of 
hsrpophosphorous  acid  by  Marie  (Compt.  rend. 
133,  219). 

Sodium  in  the  presence  of  water  reduces 
acetone  to  Mopropyl  alcohol  and  pinacone  (Fittig, 


Annalen,  110.  25;  114,  64;  Stadeler,  Annalen, 
111,  277;  Fnedel,  Annalen,  124,  329),  but  when 
the  materials  are  quite  dry  and  air  is  excluded, 
sodium  acetonate  is  formea  (Freer,  Amer.  Chem. 
J.  12,  366 ;  13,  308 ;  16,  682 ;  Taylor,  Chem. 
Soo.  Trans.  1906,  1268;  Bacon  and  Freer, 
Phillppme  J.  Sci.  1907,  2,  67).  Red-hot 
maniesium  acts  on  acetone,  yieldins  hydrogen 
and  allylene,  whilst  magnesium  amalgam  forms 
magnesium  acetonate  which  is  rapimy  decom- 
posed by  water,  yielding  pinacone  hydrate 
(Reiser,  Amer.  Chem.  J.  18,  328 ;  Couturier 
and  Meunier,  Compt.  rend.  140,  721).  Anhy. 
drous  acetone,  in  presence  of  metallic  calcium, 
is  slowly  converted  at  the  ordinary  temperature 
into  mesityl  oxide  (Raikow,  Chem.  Zeit.  1913, 
37,  1466).  Chlorine,  bromine,  and  iodine  in 
the  presence  of  alkalis  convert  acetone  into 
chloroform,  bromoform,  and  iodoform  respec- 
tively. 

RetKiiona, — ^When  quite  pure  acetone  should 
remain  perfectly  colouness  on  exposure  to  li^ht, 
and  should  not  be  attacked  by  potassium 
permanganate  in  the  cold ;  in  the  presence  of 
a^ali,  however,  and  on  warming,  carbonic  and 
oxalic  acids  are  formed  (Cloohenhausen,  J.  pr. 
Chem.  166,  461 ;  Conrov,  J.  Soc.  Chem.  Ind. 
19,  206;  Foumier,  Bull.  Soc.  chim.  1908,  3, 
269).  According  to  Witzemann  (J.  Amer. 
Chem.  Soc.  1917,  39,  2667),  the  oxidation 
process  hivolves  preliminary  enolisation  of  the 
acetone,  followed  by  the  formation  of  pyruvic 
acid: 

COMe.->CH, :  CMe*OH-»HO*CH,*CMe(OH), 
->  CHOCMe(OH), -»  CO,H*CMe(OH), 


H->C204H,+00, 


Acetone,  when  treated  with  aqueous  potash 
and  iodine,  yields  iodoform  (lieben).  Gunning 
(Zeitsch.  anal.  Chem.  24,  147)  has  modified 
this  reaction  to  render  it  available  when  alcohol 
is  present  by  employing  ammonia  and  a  solu- 
tion of  iodine  in  ammonium  iodide.  Another 
test  proposed  by  Reynolds  (ibiA,  24, 147)  is  based 
on  uie  fact  that  mercuric  oxide  is  soluble  in 
acetone  in  the  presence  of  potassium  hydroxide  ; 
the  suspected  uquid  is  mixed  with  a  solution  of 
mercuric  chloride  rendered  strongly  alkidine  with 
alcoholic  potash,  and  after  shakmg  the  mixture 
is  filtered  and  the  filtrate  tested  for  mercury  by 
means  of  ammonium  sulphide  or  stannous 
chloride.  Denigds  {Compt,  rend.  126,  1868; 
127,  963;  BulLBoo.  chim.  13,  [3]  643;  19,  [3] 
764)  recommends  the  use  of  the  additive  com- 
pound formed  by  acetone  with  mercury  sulphate, 
for  detecting  acetone  in  methyl  and  ethyl 
alcohol  (Oppenheimer,  Ber.  32,  986).  Ptonzoldt 
(Zeitsch.  anaL  Chem.  24,  147)  adds  to  the 
suspected  liquid  orthonitrobenzaldehyde,  which 
in  presence  of  caustic  alkali  combines  with  ace- 
tone to  form  indigo.  Another  delicate  test  is  to 
add  sodium  hydroxide,  hydroscylamine  and 
pyridine,  then  ether  and  bromine  until  the 
solution  is  yellow,  hydrogen  peroxide  is  now 
added  when,  if  acetone  is  present,  the  solution 
becomes  blue  (Stock);  dimethyl p-phenylenedia- 
mine  produces  a  red  colouration  which  changes 
to  violet  on  addition  of  alkali  or  acid  (Malerba, 
Zeitsch.  anal.  Chem.  37,  690).  Similar  colour  re- 
actions are  obtained  by  adding  a  few  drops  of 
sodium  nitroprusside  to  a  mixture  of  acetone  and 


M 


ACETONE. 


a  primary  aliphatic  amine  (Rimini,  Chem.  Zentr. 
L89S,  2, 132).  Of  aU  theeetests  Lieben's  is  periiapiS 
the  most  sensitive.  To  detect  acetone  in  urine  a 
strong  solution  of  sodiam  nitroprusside  is  added, 
then  the  mixture  made  alkalme  with  potash, 
vrYn*n  a  red  colouration  is  produced  which 
changes  to  violet  on  addition  of  acetic  acid  (Legal, 
J.  Pharm.  Ghim.  1888,  17,  206;  Deniste,  BulL 
Soo.  chim.  [3]  16,  1058).  According  to  Egeling 
(Chem.  Zentr.  1894,  iL  467),  it  is  best  to  use 
ammonia,  when  a  brilliant  violet  colour  is  at 
once  produced:  this  reaction  is  not  given  by 
aldehyde.  For  other  methods  of  detecting  and 
estimating  acetone,  compare  Arachequesne, 
Compt.  rend.  110,  642;  Collischonn,  Zeitsch. 
anaL  CSiem.  29,  662;  Squibb,  J.  Amer.  CSiem. 
Soo.  18,  1068;  Kebler,  ibid.  19,  316 ;  Schwicker, 
Cliem.  Zeit.  16,  914;  Straohe,  Monatsh.  13,  299; 
Klar,  J.  Soc.  Chem.  Ind.  15, 299 ;  Hintz,  Zeitsch. 
anal.  Chem.  27,  182;  Sternberg,  Chem.  Zentr. 
1901,  L  270;  Keppeler,  Zeitsch.  angew.  Chem. 
18,  464;  Vaubel  and  Schleuer,  ibi£  18,  214; 
Jolles,  Ber.  39,  1306 ;  Auld,  J.  Soc.  Chem.  Ihd. 
25,  100;  Heikel,  Chem.  Zeit.  32,  76. 

(For  estimating  acetone  in  wood  spirit^  ses 
Arachequesne,  l.c;  Vi^on,  Compt.  rend.  110, 
634;  112,  873;  and  m  urine,  see  Huppert, 
Zeitsch.  anaL  Chem.  29,  632;  Salkowsla,  J. 
Pharm.  Chim.  1891,  194;  Geelmuyden,  Zeitsch. 
anal.    Chem.    35,    503;   Willen,  Chem.  Zentr. 

1897,  i.  134;  Martz,  ii  232;  Argenson,  BulL 
Soc.  chim.  16,  [3]   1055;  Studer,  Chem.  Zentr. 

1898,  L  1162;  MaUat,  J.  Pharm.  1897,  6296; 
SabbaUni,  Cbem.  Zentr.  1899,  ii.  22 ;  Ri^ler, 
Zeitsch.  anaL  Chem.  40,  94;  Voumasos,  BuU. 
Soc.  chim.  31,  [3]  137 ;  Graaff,  Pharm.  Week- 
blad,  1907,  44,  555;  Folin,  J.  BioL  Chem.  1907, 
3,  177 ;  Monimart,  J.  Pharm.  Chem.  1892,  26, 
392 ;  Heikel,  /.c. ;  Hart ,  J.  Bud.  Chem.  1908,  4, 
477.) 

DerivaUvu. — ^Acetone  combines  directly  with 
a  large  number  of  substances  yielding  well- 
characterised  additive  compounds.  1.  Com- 
pounds  wUh  alkaline  sulphites : — Acetone  forms 
definite  crystalline  compounds  when  shaken  with 
concentrated  solutions  of  the  acid  sulphites  (bi- 
sulphites) of  the  alkali  metals  (Preoht,  Phot. 
Centr.  1902,  8,  301;  Kerp,  KaiserL  Gesundh. 
1904, 21, 40;  Rothwood,  Monatsh.  26, 1645).  The 
potassium  salt  C,H«0,KHSOt,  and  the  sodium  salt 
(XH,0,NaHSO„  crystallise  in  nacreous  foales 
(Limpricht,  Annalen  93,  238) ;  the  ammonium 
salt  C,H«0,NH4HS0,  crystallises  in  laminn 
(St&deler,  Annalen,  HI,  307).  The  barium 
salt  has  formula  2C,H.0,Ba(S0,H)„H,0  (Fa- 
gard.  J.  Pharm.  Chim.  1896, 2, 146).  These  salts 
yield  acetone  when  heated  with  aqueous  potash. 
Calcium  chloride  combines  with  acetone  to  form 
CaCl,,2C,H«0  and  CaCI.,  C,H«0  (Bagster,  Chem. 
Soc  Trans.  1917.  HI,  494).— 2.  Compounds 
unlh  chloroform  (Willgerodt,  Ber.  14,  2451; 
15,  2308 ;  (Cameron  and  Holly,  Chem.  Zentr. 
1898,  u.  277;  Jocitsch,  ibid,  1899,  L  606; 
Willgerodt  and  Diirr,  J.  pr.  Chem.  148,  283). 
— 3.  Compounds  with  hydrogen  cyanide  (Urech, 
Annalen,  164,  255): — Acetone  yields  acetone- 
oyanhydrol  C^HtNO,  b.p.  120^  whon  added  to 
anhydrous  hydrogen  cyanide ;  and  diacetone- 
oyanhydrol  CrHiaifO,,  a  crystalline  substance, 
whon  treated  with  a  25  p.a  solution  (aqueous)  of 
hydrof^pn  cyanide  (Tiemann  and  Friedlander,  Ber. 
H,  1965);  with  3*3  p.o.  hydrogen  cyanide  acetone* 


cyanhydrin  is  obtained  in  the  dark,  but  in  the 
light  a  mixture  of  products  is  formed  (Silber, 
Ber.  38, 1671).—  4.  Compounds  tpith  ammonia : — 
Ammonia  unites  with  acetone  in  the  cold  with 
the  elimination  of  the  elements  of  water ;  the 
reaction,  however,  proceeds  more  quickly  if  the 
temperature  is  raised  to  100*,  or  if  dry  ammonia 
gas  is  passed  into  boiling  acetone.  Several 
bases,  diaoetonamine  C«H^,N0,  triacetonamine 
C,H,.NO,  triacetonediamme  C^K^^fi,  and 
dehyarotriacetonamineC»Hi,N;  the  last  two  in 
very  small  quantity  only,  have  been  obtained  bv 
these  methoidsy  the  relative  proportions  in  which 
they  are  formed  varying  with  the  temperature 
and  time  employed.  These  bases  and  their 
derivatives  have  been  examined  by  Heinta 
(Annalen,  174,  133 ;  176,  262 ;  178,  306,  326 ; 
181,  70 ;  183,  276 ;  189,  214 ;  191,  122  ;  198, 
42,  87  ;  201,  90 ;  203,  336)  and  by  Sokolow  and 
Latechinow  (Ber.  7,  1384),  Buhemann  and 
Carnegie  (Chem.  Soa  Trans.  1888,  424),  Rughei- 
mer  (Ber.  21,  3326;  26,  1662),  Harries  (An- 
nalen, 296,  328),  Franchimont  and  Friedmann 
(Rea  Trav.  Chim.  1907, 223),  Gabriel  and  Colman 
(Ber.  36,  3805),  Kohn  and  Lindauer  (Monatsh. 

23,  764),  Kohn  (Annaton,  361,  134 ;  Monatsh. 

24,  765,  773;  26,  136,  817,  860;  28,  429, 
508, 629, 537, 1040);  they  yield  weU-crystallised 
salts,  and  can  be  separated  from  one  another 
b^  means  of  their  ozaXates.  Methylamine  also 
fives  corresponding  compounds  with  acetone, 
but  dimethylamine  yields  dimethyldiaoeton- 
amine  as  the  sole  product  (Gdttsohmann, 
Annalen,  197,  27). 

Thioacetones  have  been  studied  by  Bau- 
mann  and  Fromm  (Ber.  22,  1036,  S69S). 
Acetone  forms  comjwunds  with  mercuric  sul- 
phate (Denig^s,  Z.c. ;  Oppenheimer,  Lc),  with 
mercuric  oxide  (Auld  and  Hantzsch,  Ber. 
33,  2677;  Lasserre,  J.  Pharm.  Chim.  1890, 
22,  246),  with  mercuric  cyanide  (Marsh  and 
Struthers,  Chem.  Soc.  Trans.  1905,  1878),  with 
mercuric  iodide  (Gernea,  Compt.  rend.  137,  256; 
Mush  and  Struthers,  Chem.  Soc.  Proc  1908, 
260),  and  with  mercuric  nitrate  (Hoimann* 
Ber.  31,  2212).  Metallio  derivatives .  of  the 
type  CHa*CO*CHaK  are  obtained  by  the  elec- 
trolysis of  acetone  solutions  of  potassium  or 
sodium  iodides  or  of  potassium  thiocyanate 
(Levi  and  Vogbera,  Gaaz.  chim.   ital.   35,   L 

277). 

Acetone  yields  substitution  derivatives  when 
acted  upon  with  chlorine  or  bromine  (Bischoff, 
Ber.  6,  863,  963;  8,  1329).  The  following  deriva- 
tives have  been  obtained: — ^IConocldoracetone 
rHenry,  Ber.  5, 190;  Mulder,  Ber.  6,  1009;  Bar- 
bafflia,  Ber.  7,  467 ;  Linnemann,  Annalen,  134, 
171;  Koeniffs  and  Wagstaffe,  Ber.  26,  554; 
Wislicenus,  Kiroheisen  and  Sattler,  ibid.  26, 
908;  Fritsch,  ibid.  26,  697;  Tohemiac,  Ber. 
26,  2629 :  Kling,  BulL  Soa  chim.  [3]  33,  322) ; 
unsymmetrical  dichloracetone  (Fittig,  Annalen, 
110,  40;  Borsche  and  Fittiff,  Annalen,  133, 
112:  Erlenbaoh,  Annalen,  269,  46;  Tchemiao, 
l.c. ;  Fritsch,  Uc, ;  Mcintosh,  (}hem.  Soc.  Trans. 
1905,  790) :  symmetrical  dichloracetone  (Barba- 
fflia,  lc. ;  Fritsch,  Lc);  tricbloracetone (Bischoff, 
^c. ;  Kraemer,  Ber.  7,  252;  Perrier  and  Prost, 
Compt.  rend.  140, 146 ;  Hantzsoh,  Ber.  21,  242) ; 
tetrachloracetone  (Bischoff,  Levy,  Witte  and 
C'urchod,  Annalen,  252,  330,  254,  83;  Levy 
and  Jcdlicka,  Ber.  21,  318);    and  pentachlor* 


ACETONE  OIL. 


S7 


•oetooe  (CMi,  BoIL  8o«l  obim.  fS]  39,  838; 
Fritsch,  Annaleo,  279,  310  and  Le. ;  Levy 
andJedlicka,  ic).  PenUchlomfnetone  treated 
with  phoaphonia  pentachloride  TieldB  cu-bepta- 
chlon^nopane  C|C1,«»  a  ofystaUiiio  sabatanoe, 
nLp.  ^ ;  also  obtained  by  tbe  direoi  addition 
of  ebloroionn  to  tetfa43hloioetbyfene  under  tbe 
inflnenoe  of  alnmininm  cbloride  (Boeseken  and 
Piina,  Ploe.  K.  Akad.  Wetenaeb.  Amaterdam, 
1911,  13,  686).  The  oorresponduig  biomo- 
derivativea,  with  the  exception  of  tribromaoa- 
tone,  are  obtained  by  the  direct  action  of 
bromine  opon  acetone  (Mulder,  J.  1864,  330; 
Molntosh,  I.C. ;  Lapworth,  Chem.  Soa  Trana. 
1904,  33),  also  by  other  methods  (Hjelt  and 
SiTen,  Ber.  21,  3288 ;  Norton  and  Wistenhoff, 
Amer.  ChenL  J.  10, 213 ;  Hantaaob,  {.c).  Other 
halogen  deriyativea  (J.  Soe.  ChMn.  Ind.  16, 
933  ;  Hantnob,  Le,  and  Ber.  22,  1238)  and  the 
oompoondfl  of  acetone  with  the  halogen  acids 
(Arenibald  and  Mcintosh,  Chem.  Soo.  Trans. 
1904,  924)  have  been  described. 

Acetone  forms  a  large  number  of  condensa- 
tion prodaots  and  derivatives  with  other  organic 
compounds:  Gyan^betones  (Hantzsch,  Ber.  23, 
1472  ;  Tchemiac,  Ber.  25,  2607,  2621 ;  Kowppa, 
Ber.  33,  3530).  Acetone  diozalic  ester  obtamed 
hj  the  action  of  sodium  ethylate  on  a  mixture 
of  acetone  and  oxalic  estet  is  conTcrted  when 
treated  with  sodium  ethoxide  to  a  dienolic 
substance  forming  lemon-yellow  needles,  m.p. 
98*,  and  dyeing  wool  in  alcoholic  solution. 
It  is  the  first  nitrogen  free  dye-stuff  of  the  fatty 
series  yet  obtained  (Willstatter  and  Pummerer, 
Ber.  37,  3733).  Pseudocycfocitralidene  acetone 
and  its  homologues  have  an  odour  of  violets, 
and  are  suitable  for  use  in  perfumes  (J.  Soe. 
Chem.  Ind.  24,  290). 

For  acetone  dicarboxylic  acid  and  its  deriva- 
tives, «ee  Ormerod,  Chem.  Soe.  Proc  1906/  2^05 ; 
Denig^  Compi.  rend.  128,  680;  Lippmann, 
Ber.  41,  3981;  for  acetonyl  acetone  and  its 
derivatives,  see  Knorr,  Ber.  22,  168,  2100; 
Claisen  and  Ehrbardt,  Ber.  22,  1009 ;  Zincke 
and  Kegel,  Ber.  23,  230;  Olaisen,  Ber.  25, 
3164 ;  the  azo-  (Bulow  and  Schlotterbeck,  Ber. 
35,  2187)  and  diazo-  derivatives  of  acetonyl 
acetone,  hav^  dyeing  properties  (Fauiel,  Compt. 
nnd.  128,  318). 

Acetone,  with  diazobenzene  chloride  in  the 
presence  of  alkali,  yields  a  compound  Cj  5H1 4ON,. 
m.p.  134*-135*,  which  has  dyeing  raoperties 
(Bamberger  and  Wulz,  Ber.  24, 2793).  For  other 
condensation  products  compare  Boessneck,  Ber. 
21,  1906 ;  Pechmann  and  Wehsarg,  ibid,  2989, 
2994;  Franke  and  Kohn,  Monatsh.  19,  354; 
20,  876;  Spier,  Ber.  28,  2531;  Perkin  and 
Thorpe,  Chem.  Soo.  Trana.  1896, 1482  ;  Weidel, 
Monatsh.  17,  401 ;  Mioko,  ibid.  442 ;  Stobbe 
Ber.  28,  1122;  Comelson  and  Kostanecki,  Ber. 
29,  240;  Claisen,  ibid,  2931;  Rohmer,  Ber.  31, 
281 ;  Pfitzinger,  J.  pr.  Chem.  164,  283  ;  Freer, 
Amer.  Chem.  J.  17,  1 ;  Barbier  and  Bouveault, 
Compt.  rend.  118,  198;  Haller  and  March. 
Compt.  rend.  139,  99 ;  Straus,  Ber.  37,  3293 . 
Harries  and  Ferrari,  Ber.  36,  656 ;  Ulpiani 
and  Bemardini,  Atti  R.  Accad.  Lineei,  1904, 
13,  331 ;  Pechmann  and  Sidgwiok,  Ber.  37, 
3816;  Duntwitz,  Monatsh.  27,  773;  Knoeve- 
nagel,  Ber.  30,  3451,  3457 ;  Purdie,  Chem.  Soa 
Trans.  1906,  1200 ;  Richard,  Compt.  rend.  145, 
129.  Diacetones  and  their  derivatives  have  been 


studied  by  Combes  (Oomnt.  rend.  108.  1252; 
Behal  and  Auger,  Compt.  rend.  109,  970; 
Claisen  and  SMos,  Ber.  21,  141);  derivatives  of 
tiiaoetone  by  Weinsohenk  (Ber.  34,  21851 

ACnomCHLOBOroRM,  •aa-frtdblor-3-Av. 
dmry-fi-mdh^iprowme  (Chlonkme)  (CH,),  <XOH> 
CC9„  prepared  by  slowly  adding  powderotl 
potassium  hydronde  (3  parts)  to  a  cooled 
mixture  of  acetone  (5  parts)  and  chloroform 
(1  part)  (Willgerodt,  J.  pr.  Chem.  [2]  37,  361)  is 
a  white  omtalline  compound,  b.p.  167*,  melt- 
ing near  but  above  97*;  it  has  a  camphor- 
lilre  odour,  is  soluble  in  hot,  sparingly  soluble 
in  cold  water,  and  orystaltises  well  from  ether, 
alcohol,  acetic  acid,  acetone,  or  chloroform ;  it 
forms  no  definite  hydrate,  but  the  system  acetone- 
chloroform /water  presents  a  quadruple  point 
for  the  aolio,  two  solutions  and  the  vapour  at  75*2' 
(Cameron  and  Hollv,  J.  Phys.  Chem.  1898,  2, 
322).  The  acetaU  '(CH,),-C(OAo)<X1,  boils  at 
191*  The  bemoaU  (CH,),-(3(0Bz).CCl,  boils  at 
282"*  (Willgerodt  and  Durr,  J.  pr.  Chem.  [2]  39, 
283).  Acetonechloroform  is  reduced  by  sine-dust 
and  alcohol,  forming  dichloroMobutylene,  iao- 
crotylchloride,  and  iaobutylene  ( Jooitsch,  J.  Russ. 
Phys.  Chem.  Soe.  1898,  30,  920) ;  and  is  decom- 
posed by  water  at  180*,  yielding  hvdrogen 
chloride  and  by drex3rMobutyrio  acid  (Willgerodt, 
Ber.  1882,  15,  2305).  By  the  action  of  benzene 
in  presence  of  aluminium  chloride  the  chlorine 
atoms  of  acetonechloroform  are  replaced  wholly 
or  in  part  by  phenyl  residues,  and  the  compounds 
diphenykhlorimethyl  dimethyl  carbinol  (}Ph|Cl* 
CMe,*0H  b.p.  iZ^^'iphenyldichlorQmethyl  dimethyl 
carbinol  CPha,*CMe.-0H  b.p.  217'';  and  tri* 
phenylmethyl  dimethyl  cathinol  CPh,*CMe^OH 
D.p.  260*,  have  been  prepared,  and  similar 
compounds  are  obtained  using  toluene  or  p* 
xylene  (Willgerodt,  J.  pr.  Chem.  [2]  37,  861). 

Acetonechloroform  is  a  powerful  germicide,  a 
satisfactory  surgical  dressmg,  and  hypnotic  foi 
internal  use  (Aldrich  and  Houghton,  Amer. 
J.  Physiol.  1900,  3,  26);  it  is  used  as  a 
specilic  for  sea-sickness  (Merck.  Ann.  Report, 
1907, 1  )•  forming  the  chief  ingredient  of  '*  Zoto»/' 
and  a  1-2  p.c.  solution  is  used  under  the  name 
of  anesin  for  producing  local  anaBSthesia  (Cohn, 
Pharm.  Zentr.  U.  40»  33). 

ACETONBDICARBOXYLIO  ACIDv.KBTOinBS. 

ACETONB  OIL  is  the  oily  residue  remaining 
after  the  separation  of  acetone  from  the  products 
of  the  dry  distillation  of  calcium  acetate.  It 
can  also  be  prepared  by  the  dry  distillation  of 
the  lime  salts  obtained  by  neutralising  fleece 
washings  with  milk  of  lime.  About  15  litres  of 
the  oil  are  obtained  from  a  cubic  metre  of  fleece 
washings  of  11*B.  It  is  a  slightly-coloured 
liquid  of  sp.gr.  0*835,  having  a  penetrating 
8  mell  and  acnd  burning  taste.  It  consists  mainly 
of  methyl  ethyl  ketone  (A.  and  P,  Buisine, 
Compt.  rend.  126,  351;  128,561).  According 
to  Duchemin  (Bull.  Soo.  chim.  [3]  21, 798)  acetone 
oil  ia  of  very  variable  composition,  depending 
upon  the  nature  of  the  pyrolignate  from  which  it 
is  prepared.  A  French  Commission  reported  that 
it  was  effective  as  a  denaturant  of  alcohol  and 
it  was  adopted  for  this  purpose  by  the  Swiss 
Government  in  1895. 

For  details  of  mode  of  manufacture  from  wool 
washings,  v.  Buisine  (J.  Soe.  Chim.  Ind.  18, 
292;  21,  164);  P.  Baechlin,  (Rev.  Chim.  Ind.  9, 
112;  15,  240). 


AGETONIO  AOn>. 


ACETONIC     ACID,     v.    Hyd&oxybutybio 

ACID. 

ACETOPHENONE.  Phenyl  meihifl  kdone. 
Hypnone  CcH,-GO*CH,*  is  obtained  by  acting 
with  benzoyl  chloride  on  zinc  methyl;  by 
distilling  a  mixture  of  the  calcium  salts  of 
benzoic  and  acetic  acids ;  or  by  boiling  toother 
benzene  and  acetyl  chloride  with  alummium 
chloride.  It  can  oe  isolated  from  the  fraction 
of  heavy  oil  of  coal  tar  boiling  at  160^-19(r 
by  addition  of  sulphuric  acid,  distilling  the 
solution  in  steam  and  converting  the  distillate 
into  the  |i-bromophenylhydrazone  derivative 
of  acetophenone  (Weissgerber,  Ber.  36,  754). 
It  is  best  obtained  synthetically  by  adding 
small  quantities  of  sublimed  ferric  chloride 
(7  parts)  to  a  mixture  of  benzene  (6  jparts)  and 
aoetvl  chloride  (7  parts)  diluted  with  carbon 
disulphide.  The  mixture  is  then  warmed  on  the 
water-bat^,  dried  and  fractionated  (Nencki  and 
Stoeber,  Ber.  30, 1768). 

Acetophenone  crystsJlises  in  laige  plates,  m.p. 
2O'0*;  b.p.  202^.  It  possesses  a  perri^nt 
odour  of  oil  of  bitter  almonds  and  cherry  laurel 
water ;  is  insoluble  in  water,  but  dissolves  easily 
in  alcohol,  ether,  chloroform,  or  benzene. 
It   is  readily  oxidised   by  potassium  perman- 

Sanate  to  phenyl^yoxylic  acid  (Qlucksmann, 
lonatsh.  11, 246).  By  we  action  of  ammonia  on 
an  alcoholic  solution  of  acetophenone,  the  aceto- 
phenone ammonia  is  formed  GMeFh(N :  CMePh)s, 
m.p.  116®  (Thomae,  Arch.  Pharm.  244.  643)  (v. 
Ketohss). 

Acetophenone  forms  a  large  number  of  deriva- 
tives and  condensation  products  with  aldehydes, 
halogeiis,  acids,  mercury  salts,  ftc.  B^  the 
action  of  hydrogen  in  presence  of  finely  divided 
nickel  it  may  be  converted  into  phenyl  methyl 
carbinol. 

Acetophenone  was  discovered  by  Dujardin- 
Beanmetz  and  Bardet  to  possess  powerful 
soporific  properties  (Gompt.  rend.  KH,  960; 
Karmensky,  Liss.  Med.  Chi  Acad.  St.  Peters- 
buis,  1888-1889,  No.  70).  In  quantities  of  006 
to  0*15  gram,  it  induces  a  quiet  sleep,  but  is 
said  to  impart  a  disagreeaole  odour  to  the 
breath  (Pharm.  J.  1886,  682). 

AminoaedoD^enone  (Camps,  Arch.  Pharm. 
40,  16),  b.p.  260''-262'>;  136717  mm.,  has 
anaesthetic  properties,  which  are  not  diminished 
bv  condensmg  it  with  aldehydes  containing  a 
phenolic  hydroxyl,  but  are  destroyed  when  it  is 
condensed  with  benzaldehyde,  tolualdehyde, 
or  cinnamaldehyde  (Hildebrandt,  Chem.  Zentr. 
1906,  ii.  602 ;  Sohok  and  Huber,  Ber.  37,  390 ; 
Schifer,  Ber.  39,  2181). 

p-Amino  acetopkaume  v.  Ketones. 
Acetopkenonephendidenep  in.p.  88®,  an  anti- 
pyretic substance,  can  be  obtained  by  heating 
molecular  proportions  of  acetophenone  and  p- 
phenetidene  in  vacud,  then  distilling  in  vacud  at 
210^-212®  (Valentiner,  J.  Chem.  Soc.  Ind.  16, 
60 ;  17,  602). 

^-ACETO-PROPIONIC  ACID.      Lcevulic  acid 

CH,<X)  GH.-CHjK^jH. 

This  substance  is  formed  by  the  action  of  dilute 
acids  on  a  number  of  carbohydrates — e.g,  levu- 
lose,  inulin,  galactose.  It  is  also  a  product  of 
oxidation  of  the  terpene  alcohols,  but  is  best 
prepared  by  heatins  on  the  water- bath  cane 
sugar  with  dilute  hydrochlorio  aoid  (4  vols. 


water,  1  vol.  cooc.  aoid)  until  a  brown  flocoulent 
precipitate  is  no  longer  formed.  (Compare  Tol- 
lenSy  Ber.  17,  668;  WehmeTf*.  Tollens,  Annalen, 
243,214.)  The  filtered  liquid  is  then  evaporated 
on  the  water-bath,  extracted  several  times  with 
ether,  and  after  distilling  off  the  ether  the 
residue  is  fractionated  in  a  vacuum. 

It  can  be  obtained  by  the  hydrolysis  of  various 
nudeio  acids  (Kossel  and  Neumann,  Zeitsch. 
physiol.  Chem.  27,  2216;  Inouye,  ibid,  42,  117; 
Levene,  ibid.  43,  119).  For  other  methods  of 
preparation,  compare  Tiemann  and  Semmler 
(Ber.  28,  2129);  Verley  (Bull.  Soa  chim.  [3] 
17,  190);  Erlenmeyer  (J.  pr.  Chem.  179,  382); 
Bkuae  (Bull.  Soc.  chim.  [3]  21,  647). 

Lttvulic  acid  crystallises  in  plates  which 
meltat  33*.  It  boils  at  239"*,  148<>-149* /16  mm. 
(Michael,  J.  pr.  CSiem.  162,  113),  ana  has  at 
16*  a  sp.gr.  1*136.  It  is  very  soluble  in  water, 
alcohol,  or  ether,  and  is  not  attacked  b^ 
Inomine  in  the  cold.  Nitric  acid  converts  it 
into  carbon  dioxide,  acetic  acid,  succinic  and 
oxalic  adds.  Iodine  and  sodium  hydroxide  form 
iodoform  even  in  the  cold.  Hydriodic  acid  and 
phosphorus  at  200*  convert  it  into  normal  valeric 
acid  ;  whereas  sodium  amalgam  forms  sodium 
7-hydroxyvalerate  acid  in  an  alcoholic  solution, 
and  normal  valeric  acid  in  an  acid  solution. 
When  added  to  boiling  iodic  acid  solution  diiodo- 
acetoaorylic  acid  is  formed  (Angeli  and  Ghiassi, 
Ber.  26,  2206).  When  placed  over  suli|hario 
acid  in  a  vacuum  it  decomposes,  leaving  a 
residue  of  dihydroxyvaleric  acid  (Bibelot  and 
Andr^,  Compt.  rend.  123,  341). 

The  mercury  saltHg((30H,O,)t,  which  crystal- 
lises in  silvery  plates,  breaks  up  on  treatment 
with  sodium  hydroxide,  forming  the  two  mer- 
curilsBvulic  acids  C.HfOjHg  and  C^H^O^Hg,. 
Lnvulic  acid  readily  condenses  with  benzil 
(Japp  and  Murray,  Chem.  Soc.  Proo.  1896,  146), 
and  with  aldehydes  (Meingast,  Monatsh.  26, 265). 
It  forms  a  semi-carbazone,  m.p.  187*  (Blaise, 
{.c).  The  ethyl  ester  when  treated  with  ethyl 
magnesium  bromide  jrields  a  lactone,  b.p. 
106°-106*/18  mm.  (Grignard,  Compt.  rend.  135, 
627).  Halogen  substitution  derivatives  of  lae- 
vulic  acid  have  also  been  obtained  (Wolff,  Ber. 
26,  2216 ;  Wolff  and  Rudel,  Annalen,  294,  192; 
Conrad  and  Schmidt,  Annalen,  286,  203). 

The  substance  is  employed  on  a  manufa>- 
turing  scale  as  a  mordant  instead  of  acetic  add, 
as  it  possesses  the  advantage  of  not  being  volatile 
with  steam. 

It  is  also  used  in  the  preparation  of  the  anti- 
pyretic antithermin,  Pnenylhydrazine  is  dis- 
solved in  dilute  acetic  acid,  and  on  adding  a 
solution  of  Isvulic  acid  a  yellow  precipitate  is 
formed,  which  is  purified  by  recrystallisation 
from  alcohol  (Pharm,  J.  [3]  xvii.  80*1)  (v.  Anti- 

THEBMIir). 

ACETOPURPURINE    v.    Azo-    ooloubino 

MATTKBS. 

ACETOPYRIMB  or  ACOPYRINE.  A  com- 
bination  of  phenvl-dimethyl  pyrazolone  (anti- 
pyrine)  and  acetyl  salicylic  acid. 

ACETOSAL  or  ACETYSAL.  Syn.  for  acetyl 
salicylic  acid. 

ACETO-i)-TOLUIDIDE  is  obtained  by  the 
action  of  acetic  acid  upon  toluidine.  Mdts  at 
163'*  and  boils  at  307^ 

ACETOZONE.    Mixture     of     acetylbeozoyl 


ACETYLENE. 


C  H  "CO 
peroxide    qh'cO^^^^  '^^  kieselgiilir,  uaed 

ACETPHKIIKTiDKHB  v.  PHXNAoniK. 

ACETYlJCHOIJltB  v.  Ergot,  Muscabins. 

AGETYL-l-NAPHTHTLAMIllS-  5  •  8ULPH0- 
MIC  ACID  18  prepared  by  bbiling  a  mixture  of 
5  parte  of  l-iiaphthylamine-5-siilphoiiic  aoid, 
glaciJ  acetic  aci<C  acetic  anhydnde  and  sodiiim 
acetate  under  a  reflux  oondeiuer  until  a  sample 
cannot  be  diazotiaed.  The  mixture  is  then 
heated  so  long  as  acetic  acid  and  acetic  anhydride 
distil  over. 

AGETTL-l :  4  N APHTHYLElfEDIAiaifE-6 - 
SULPHONIC  ACID  is  obtained  by  adding  mono- 
acetyl  1 : 4  naphthylenediamine  sulphate  to 
fummg  sulphuric  acid  containing  20  p.c.  SOt> 
wanning  to  40^-50°  and  pouring  into  ice-cold 
water.  Or  a  mixture  of  l-naphthylamine-6  and 
7  •  sulphonic  adds  (deve's  Acids)  may  be 
aoetylated  with  glacial  acetic  acid,  distilling  off 
the  excess  of  acetic  acid,  dissolving  the  product 
in  sulphuric  acid  and  adding  a  cooled  mixture  of 
nitric  and  sulphuric  aci<u.  The  mixture  is 
diluted  with  cold  water  and  the  sodium  salts 
of  the  nitro-acids  precipitated  by  addmg 
common  salt.  The  mixture  of  the  nitro-acids 
is  reduced  by  iron  filings  and  acetic  add,  made 
alkaline  by  sodium  carbonate,  filtered  hot, 
slightly  addified  and  the  1 : 4-naphthylene- 
diamine-6-8ulphonic  acid  precipitated.  This 
is  acetylated  by  boiling  with  a  mixture  of 
acetic  acid  and  sodium  acetate  (Levinstein, 
Eng.  Pat.  12119  (1898);  GasseUaandCo.  D.R.P. 
116922).  Used  in  twAlring  Diaminogen  blues. 
(Cain,      '  Litermediate  Products    for    Byes.*) 

Cf.  NiFHTHAIiBNS. 

AGETTL .  D  -  PHENYLENEDIAMIME      (p  • 

amino  acetanilide) 


NH, 


NHCO-CH, 


is  prepared  by  reducing  jy-nitroacetanilide  with 
iron  filings  and  acetic  add  at  60^,  rendering  the 
solution  alkaline  with  sodium  carbonate  and 
adding  common  salt  and  hydroohlorio  acid 
when  the  hydrochloride  of  acetyl-p-phenylene 
diamine  crystaUises  out  (Qran<unouffin,  Rev. 
prod.  chim.  1917, 20, 260).  Acetyl-p-phenylene- 
diamine  melts  at  162-5^ 

ACETYLENE  C,Ht  is  the  first  member  of 
the  aeries  of  unsaturated  aliphatic  hydrocarbons 
to  which  it  gives  its  name,  and  having  the 
general  formula  :  GMHtn  -  s*  Tins  formula  also 
applies  to  the  dialkylenes  the  difference  being 
that  members  of  the  acetylene  series  are 
characterised  by  the  presence  of  one  triple 
linkase  whilst  the  dialkylenes  possess  two 
double  linkages : — 

CHjCH  CHiCCH,         CH.CiC'CH, 

Acetylene  Proplne  (C^B^         Butlne  (C4H,) 

(OgH^.      (or  Methyl  acetylene  (Dimethyl  acetylene 
or  AUylene).  or  Orotonylene.) 

and  CH,C :  CH,        CH,  :  CHCH  :  CH, 

Propadlene  (C^B^,         Butadiene  (C^Hg). 

The  dialkylenes  will  not  therefore  be  considered 
in  this  section.    {See  Sykthetio  Rubber,  Iso- 

FRENB,  BUTADIBNE.) 

NomenckUure. — ^According  to  the  Geneva 
system  aoe^lene  is  to  be  termed  Ethine,  the 
ending  -ine  being  the  systematic  termination  for 
members  of  the  acetylene  series,  thus :   propine, 


butine,  etc.  In  practice,  however,  the  original 
name  acetylene  is  always  uaed  as  being  well 
eetabUshed  and  unlikely  to  cause  contusion. 
With  the  exception  of  lUlylene  G,H4,  and  cro> 
tonylene  CfH^,  higher  memben  of  the  series  are 
usnallv  named  as  substituted  acetylenes*  e.<7. 
methyl-acetylene,  dimethyl-acetylene,  isopropyU 
acetvlene,  phenyl-acetn^Iene,  &c 

Hi%torieaL — Acetylene  was  first  observed  by 
Edmund  Davy  as  a  gas  produced  on  treating 
with  water  the  impure  residues  obtained  in  the 
preparation  of  potassium  (Brit.  Assoc.  Rep. 
1836,  p.  62  :  Annalen,  23,  144).  The  first  svs- 
tematic  examination  of  the  gas  was  made  by 
Berthelot  (Compt.  rend.  54,  640 ;  Annalen,  123, 
212  ;  Ann.  Chim.  Phys.  [7]  23,  444  ;  [8|  6,  182), 
who  examined  the  composition  and  properties 
of  acetylene  and  showed  its  production  in  many 
pyrochemical  processes. 

Of  particular  interest  to  the  technical 
chemist  ia  the  discovery  by  Wohler,  in  1862 
(Annalen,  124,  220),  that  a?etylcne  is  pioduced 
hy  treating  calcium  carbide  with  water,  a 
discovery  that  served  thirty  years  later  as  the 
starting  point  for  the  whole  acetylene  industry 
when  it  was  shown  by  Wiilson,  in  1892,  that 
calcium  carbide  could  be  produced  on  a  lai^e 
scale  and  in  fairly  pure  condition  in  the  dectric 
furnace.  For  more  than  a  decade  after  the 
introduction  of  calcium  carbide  on  a  commercial 
scale,  the  chief  interest  in  the  subject  lay  in  the 
direction  of  the  utilisation  of  the  gas  for  illu- 
minating purposes,  as  it  was  widely  ^lieved  that 
the  pure  white  light  of  acetylene,  and  its  con- 
venience of  manufacture  in  small  quantities, 
would  soon  cause  it  to  oust  coal-gas  from  the 
field  to  a  great  extent.  This  e3cpectation  has 
not  been  nUfiUed,  though  acetylene  continues 
to  be  of  great  use  for  various  purposes  such  as 
flares,  &c.  The  next  stage  was  the  use  of  the 
oxy-acetvlene  flame  for  the  *  autogenous 
welding  of  iron,  an  industry  that  to-day 
utilises  a  considerable  amount  of  the  gas.  In 
the  first  decade  of  the  present  century  attempts 
were  made  to  effect  the  chemical  utilisation  of 
acetylene  in  various  ways,  chiefly  by  the  addition 
of  chlorine  and  the  formation  of  various  chlorine 
derivatives  of  different  boiling-points  which  are 
suitable  as  solvents  for  many  purposes  and 
serve  to  replace  inflammable  materials  such  as 
benzene,  gasoline,  and  so  on,  for  dry-cleaning, 
fat-extraction,  &c.  On  these  lines  much  useful 
work  has  been  done  in  this  country  by  Tomp- 
kins, and  by  the  Clayton  Aniline  Company,  and 
abroad  by  the  Chemische  Fabrik  driesheim- 
Elektron,  and  the  Consortium  fur  elektro- 
ohemisohe  Industrie  G.m.b.U.  Lastly,  since 
1910,  it  has  been  found  possible  to  produce 
acetfikldehyde  direct  from  acetylene  on  a  technical 
scale  by  the  use  of  mercury  salts  as  catalysts, 
with  the  result  that  progress  in  this  field  h&s 
been  remarkably  rapid,  and  the  production  of 
such  diverse  substances  as  alcohol,  acetic  acid, 
acetic  anhydride,  and  acetone  from  acetylene 
on  a  commercial  scale  is  already  an  accomplished 
fact  which  may  have  vast  economic  consequences. 

(See  ACBTALDBHYDE.) 

Production, — (1)  By    ifie    direct    union    of 
carbon  and  hydrogen  in  the  electric  arc 

2C+H,  =  C,H, 
(Berthdot,  Compt.  rend.  54, 640 ;  Annalen,  123, 


46 


AOETiTLENfi. 


212  ;  Ann.  Chim.  Phys.  [7]  23,  444  ;  [8]  6,  182  ; 
Bone  and  Jordan,  Chem.  Soo.  Trans.  71,  41 ; 
79, 1042 ;  Pring  and  Hutton,  Chem.  Soc.  Trans. 
§9,  1600;  V.  Wartenbeig,  Zeitsch.  angew. 
ChenL  62,  310.) 

(2)  From  dhylene  dibromide  or  dichloride  by 
ihe  action  of  aicoholio  potash,  with  the  inter- 
knediate  formation  of  vinyl  chloride  or  bromide : 

OH,BrCH,Br-HBr  =  CH, :  CHBr 
CH, :  CHBr-HBr  =  CH :  CH 

(Sawiteoh,  Compt.  rend.  52,  157 ;  Bfiasnikow, 
Annalen,  118,  330;  de  Wilde,  Ber.  7,  352; 
Sabanejew,  Annalen,  178,  109 ;  Zetsel,  Annalen, 
191,  368 ;  de  Forcrand,  Compt.  rend.  104,  697  ; 
Mouneyrat,  Bull.  Soo.  chim.  [3]  19,  184 ; 
Memiier  and  Despannent,  Compt.  rend.  144, 
273 ;  Bull.  Soo.  chim.  [4]  1,  342. 

(3)  By  trecUinq  various  halogen  compounds 
with  metals,  e,g,  by  treating  tetraohlorethane 
with  metaUic  zinc : 

CHCl,CHaa4-2Zn  =  CH  :CH+2ZnCa, 

(Sabanejew,  Annalen,  216,  252),  or  by  the 
action  of  silver,  copper,  or  zinc  dust  on  iodo- 
form, or  bv  the  action  of  the  copper-zinc  couple 
on  bromoform  (Cazeneuve,  Compt.  'rend.  97, 
1871 ;  113,  1054). 

(4)  By  electrolysis  of  unsaturated  carboxylic 
acids,  such  as  f  umaric  or  maleic  add : 

CHCOOH       CH 

II  =  IIL+200,-f  H, 

CHCOOH      CH 

(Anode)       (Kathode) 

(Kekul6,  Annalen,  131,  85). 

(5)  From  acdjflene  moiuh  or  di-carboxi^ 
acids: 

C,(COOH),  =  C,H,+2C0, 

(Lessen,  Annslen,  272,  140).  (C/.,  however, 
Vamsetti  and  Fasoli,  Gazz.  chim.  itaL  46,  i.  49.) 

(6)  From  proparg^  aldehyde  by  the  action 

CH:C-CHO+NaOH  =  CHjCH+HCOONa 

(COaisen,  Ber.  31,  1023). 

(7)  By    decomposition    of   various    complex 
organic    substances :     e.g.    brom-cydo    butene 
(c/.  Knoir  and  Matthes,  Ber.  32,  740;    Will- 
statter    and    v.    Schmaedel,    Ber.    38,    1994  ; 
Gabriel,  Ber.  38,  2405.) 

(8)  From  copper  acetylide  by  the  action  of 
aqueous  potassium  cyanide  (Baeyer,  Ber.  18, 
2273;  c/.  also  Zeisel,  Annalen,  191,  368; 
Romer,  Annalen,  233,  182  ;  Koyes  and  Tucker, 
Amer.  Chem.  J.  19,  123).  This  method  is 
stated  to  ^ield  extremely  pure  acetylene :  if 
hydrochloric  acid  be  used,  instead  of  potassium 
cyanide,  the  gas  is  not  so  pure  and  possibly 
contains  traces  of  vinyl  chlonde. 

(9)  By  the  action  of  water  on  calcium  carbide  : 

CaC,-fH,0=Ca(OH),+C,H, 

Strontium  and  barium  carbides  act  similarly. 
(Wohler,  Annalen,  124,  220;  Travels,  Chem. 
Soc.  Proc.  1893,  15 ;  Maquenne,  Ck)mpt.  rend. 
115,  558  ;  Moissan,  Bull.  Soc.  chitn.  [31  11,  1007  ; 
Lewes,  J.  Soc.  Chem.  Ind.  16.  33  ;  Clowes,  ibid, 
209,  819;  Wilson,  ibid,  15,  103;  Liipke, 
Elektr.  Chem.  Zeit.  1895,  145 ;  Wyatt,  J.  Soc. 
Chem.  Ind.  14,  135,  796 ;  20,  109  ;  Bambeiger, 
Zeitsch.  angew.  Chem.  1898,  720).     This  is  by 


far  the  most  convenient  and  practicable  method 
for  the  production  of  acetylene,  and  is  invariably 
used  for  the  commercial  production  of  the  gas. 

A  oonvenient  laboratory  method  for  the 
production  of  acetylene  is  to  cover  calcium 
carbide  with  absolute  alcohol  and  to  add  water 
drop  by  drop  (Matthews,  J.  Amer.  Chem. 
Soc  22,  106). 

For  the  technical  production  of  acetylene 
and  its  use  as  an  illummant,  see  Aobtylene — 

COMMSBOIAL  AVFUCATIONS. 

Details  as  to  the  British  Patents  dealing 
with  the  subject  will  be  foimd  in  the  Patent 
Office  Abridgement  Lists,  Qass  2,  (1855-1909) 
and  Class  2  (i)  (1910-1915). 

Acetylene  is  produced  in  the  inoomplete 
combustion  of  various  gases  such  as  coal-gas, 
for  instance,  when  a  Bunsen  burner  'strjkes 
back.*  The  view,  however,  that  the  accompany- 
ing unpleasant  odour  is  due  to  the  acetylene  is 
incorrect.  (Cf.  Mover  and  Jacobson,  Lehrbuoh 
der  organ.  C9iemie.  2nd  edn.,  L  1,  p.  853,  note  2.) 

It  is  also  produced  by  passing  methane  or 
natural  gas  through  incandescent  carbon 
(Knapp,  U.S.  Pat.  1(»3783). 

The  chief  objection  to  acetylene  produced 
from  calcium  carbide  is  the  fact  that  the  various 
impurities  present  in  the  carbide,  such  as  caldum 
sulphide,  phosphide,  etc.,  evolve  the  corre- 
sponding hydrides  on  treatment  with  water,  so 
causing  the  acetylene  produced  to  be  contami- 
nated wilii  various  small  amounts  of  gases  such 
as  ammonia,  phoqphine,  sulphuretted  hydrogen, 
arsine,  in  aiddition  to  other  hydrocarbons, 
carbon  monoxide,  hydn^en,  nitrogen  and 
oxyeen. 

Phosphine  is  probably  the  most  serious 
impurity  from  the  chemical  as  well  as  the 
physiological  point  of  view. 

A  method  of  producing  odourless  acetylene 
has  been  patented  by  S.  Ide  (Jap.  Pat.  30209, 
1916),  consisting  in  carbonising  calcareous 
materials  which  contain  phosphorus,  sulphur, 
etc.,  as  impurities,  in  tine  electric  furnace, 
spraying  wiui  water,  whereby  the  impurities 
escape  in  gaseous  form,  and  then  using  tne  pure 
lime  so  produced  for  the  manufacture  of  carbide 
in  the  usual  way ;  this  method  would,  however, 
probably  be  too  costly  to  be  of  much  use,  and  in 
practice  the  crude  acetylene  can  be  satisfactorily 
cleared  of  all  its  active  impurities  bv  suitable 

gurification  such  as  scrabbing  witn  various 
quids — for  instance,  acidified  copper  sulphate 
solution,  chromic  acid  in  acetic  or  sulphuric  acid 
— or  with  lime,  lead  or  mercury  salts,  bleaching 
powder  etc 

(Clowes,' J.  Soc.  Chem.  Ind.  16,  209,  319; 
Lunstroem,  Chem.  Zeit.  23,  180;  Beig6  and 
Reychler,  Bull.  Soc.  chim.  [3]  17,  218 ;  Gottig, 
Ber.  32,  1879;  Rossd  and  Landrisset,  Zeitsch. 
angew.  Chem.  1901,  77;  Caro,  J.  Soo.  Chem. 
Ind.  22,  17 ;  23,  15 ;  Ullmann  and  Goldberv, 
Chem,  Zentr.  1899,  ii.  19 ;  Pfeifer,  J.  f.  Gasbd, 
44,  548 ;  Jaubert,  J.  Soc.  Chem.  Ind.  24,  116; 
Willgerodt,  Ber.  28,  2107  ;  Hoffmeister,  Zeitsch. 
anorg.  Chem.  48,  137 ;  Matthews,  J.  Amer. 
Chem.  Soc.  22,  106;  Ditas,  D.B.P.  162324; 
Lunge  and  Cedercreutz,  ZeitsdL  angew.  Chem. 
1897,  651 ;  J.  Soc.  Chem.  Ind.  16, 37  ;  24, 1294 ; 
27,  798;  Wolff,  J.  f.  Gasbel.  1898,  41,  683. 
Full  details  regarding  British  Patents  dealing 
with    the    purification   of   acetylene  may   be 


ACETYLENE. 


41 


foand  in  the  Patent  Offioe  '  Fifty  Year  Subject 
Index,  1860-1910/  Class  2  (i).) 

Properties. — Aoetylene  is  a  oolourleBB  gas 
having,  in  a  pnre  state,  a  pleasant  ethereal 
odonr  (Giehant,  Berthelot  and  Moinnan, 
Compt.  rend.  121,  564),  which  is,  however, 
neaally  disguised  by  the  presence  of  f<ptid 
smelling  impurities  (Zeisel,  Annalen,  191, 
368;  Romer,  Annalen,  233,  182;  Noyes  and 
Tk^er,  Amer.  Chem.  Jonr.  19,  123).  It 
solidifies  in  liqmd  air  to  a  cmtalline  mass 
which  can  be  burnt  like  a  candfe  (Ladenbuig, 
Ber.  31,  1968).  At  the  ordinary  pressure  its 
melting-point  (—81**)  is  higher  than  its  boiling- 
point  ( -82*4'') (Ladenboigand  Eriigel, Ber.  32, 
1821 ;  33,  638;  Hunter,  Chem.  Zentr.  1906,  u 
485).  Mcintosh  and  Haass  give  the  mdting- 
pmnt  as  —81*5°,  sublimation  point  —83*6^  and 
boiling  point  -88*5''  (J.  Phys.  Chem.  11,  306; 
J.  Amer.  Chem.  Soc.  36,  737) ;  —84-0°  Burrell 
and  Robertson.  Its  critical  temperature  is 
37-06''  (Ansdell,  Proo.  Roy.  Soo.  29,  209; 
Heilbronn,  Zeitsch.  physical.  Chem.  7,  604)  or 
36*5**  (Mcintosh,  i^UL);  its  criti<»l  pressure 
67-68  atm.  (Leduc,  Ann.  Chim.  Phys.  [7]  15, 
87)  or  61 '6  atm.  (Mcintosh,  ibid.)  and  its  critical 
Tolume  83  c.c.  (Mcintosh,  Und.).  Cardosa  and 
Baume  give  the  critical  temperature  as  35*5® 
and  the  critical  pressure  as  61*5  atn^.  (Compt. 
rend.  151,  141).  For  other  physical  constants 
of  solid  and  liquid  acetylene,  see  Mcintosh, 
ibid. 

Liquid  acetylene  is  a  mobile  fluid  of  sp.gr. 
0*451  at  0°  C.  (Cailletet,  Compt.  lend.  85,  851 ; 
Ansdell,  Jahzesbericht  d.  Chem.  1879,  68)  or 
0-73  at  -75®  (Mcintosh,  ibid.).  It  has  a  high 
electrical  resistance  which  ia  not  appreoialMy 
altered  by  the  addition  of  alcohol,  ether,  halogen 
hydride,  etc.  (Mcintosh,  t&ul.). 

Acetylene  is  readily  soluble  in  many  oiganic 
solvents ;  thus  at  18®  chloroform  and  benzene 
absorb  about  four  times  their  volume,  acetic 
acid  and  alcohol  about  six  times  their  volume 
(Berthelot,  Ann.  Chim.  Phys.  [4]  9, 425 ;  Gaielli 
and  Falciola,  Atti  d.  Reale  Accaid.  dei  Lincei 
[51 13,  i.  1 10).  It  ia  extremely  soluble  in  acetone 
(Claude  and  Hess,  Compt.  rend.  124.  626; 
Claude,  Compt.  rend.  128,  303)  which  absorbs 
twenty-five  times  its  volpme  of  the  gas  at 
15®  C.  and  760  mm.,  and  under  12  atm.  takes  up 
300  volumes,  whilst  at  —80^  it  absorbs  more 
than  2000  volumes  acetylene,  which  would 
seem  to  point  to  acetone  and  liquid  acetylene 
beinff  nuscible  in  all  proportions.  According 
to  Mcintosh  (mt^a),  crystalline  compounds 
are  formed.  Tins  property  of  acetone  is  of 
great  technical  importance  in  the  storage  of 
dissolved  acetylene  for  illuminating  purposes. 
{See  AoBTTLXVE — Commbboial  Affuoations.) 
(Berthelot  and  Vieille,  Compt.  rend.  123,  623 ; 
124, 966, 988, 996, 1000 ;  WoUF,  Zeitsch.  angew. 
Chem.  1898,  919 ;  Caro,  J.  Soc.  Chem.  Ind.  25, 
1138.) 

In  water  the  gas  is  sparingly  soluble,  about 
1  p.c.  by  volume  at  12®  and  755  mm.  being 
taken  up ;  it  fonns  a  hydrate  C^Hg+fiHtO 
(Villard,  Cbmpt.  lend.  120,  1262).  The  solu- 
bility is  lowered  by  the  addition  of  salt  (Claude 
and  Hess,  v.g.).  Acetaldehyde  has  alBO  been 
suggested  as  a  solvent  or  duuent  for  acetylene 
as  it  dissolves  half  its  weight  of  the  gas  (James 
and    Watson,    U.S.    Pat.    928867;    James,  J. 


Ind.  Eng.  Uhem.  5,  115),  the  solvent  power  of 
oiganic  scdvents  appearing  in  genenu  to  be 
associated  with  the  presence  of  a .  carbonyl 
gronp  and  low  molecular  weight. 

Acetylene  is  an  endothermic  compound, 
being  formed  from  its  elements  with  an  absorp- 
tion of  approximately  50  Cals.  As  a  conse- 
quence both  the  gas  and  the  liquid  are  highly 
explosive,  particulariy  under  pressure,  for 
wmch  reason  solvents  are  used  for  storage,  as 
noted  above.  {Cf.  Maquenne,  Compt.  rend.  121, 
424 ;  Berthelot  and  Vieille,  Compt.  rend.  123, 
523  ;  124,  988,  996, 1000 ;  128, 777  ;  Ann.  Chim. 
Phys.  11,  5;  17,  303  ;  Claude,  Compt.  rend.  128, 
303  ;  Bc^elot  and  Le  Chatelier,  Compt.  rend. 
129,  427 ;  Ann.  Chim.  Phys.  20,  15 ;  Mixter, 
Chem.  Zentr.  1900,  1,  504;  ii  1007;  Chem. 
Ind.  20,  53). 

The  molecular  heat  of  combustion  ia  312*9 
Calories  at  constant  pressure.  (For  other 
thermal  properties  see  also  Berthelot,  Compt, 
rend.  82,  24  ;  Ann.  Chim.  Phys.  [5]  9,  165  ;  13, 
14;  23,  180;  Berthelot  and  Matignon,  Ann. 
Chim.  Phys.  [6]  30,  556;  Maneuvrier  and 
Foumier,  Compt.  rend.  124, 183  ;  Mixter,  Chem. 
Zentr.  1901,  u.  1250;  1905,  ii.  98;  1906,  u. 
414 ;  Thomson,  Zeitsch.  physical.  Chem.  52, 
346). 

Acetylene  when  pure  has  no  action  on  metals 
(Clowes,  J.  Soo.  Chem.  Ind.  16,  109 ;  Moissan, 
Compt.  rend.  124,  566),  but  ordinary  acetylene 
readuy  attacks  copper  owing  to  the  presence  of 
impurities  which  facilitate  the  formation  of 
explosive  copper  acetyUde  (Scheiber  and 
Reckleben,  Chem.  Zeit.  39,  42;  40,  325). 
Nickel  and  tin  in  particular  are  little  attacked 
Irjr  acetylene,  and  it  is  suggested  by  Scheiber  and 
lieckleben  that  metals  exposed  to  the  action  of  • 
acetylene  should  be  coated  with  one  of  these 
metals.  It  is  non-poisonous  in  small  quantities, 
but  may  produce  asphyxiation  when  more  than 
40  p.c.  is  present  (Clowes,  I.e. ;  Korda,  Mon. 
Sd.  45,  409;  Mosso  and  Ottolenghi,  Ann.  di. 
Chim.  e.  di.  Farmacol.  25,  163 ;  Vitali,  Chem. 
Zentr.  1898,  ii.  586;  Moissan,  /.c  ;  Gr^haut, 
Compt.  rend,  121,  564 ;  Berthelot,  Compt.  rend. 
121, 666  ;  Brociner,  ibid.  121, 773  ;  J.  Soc.  Chem. 
Ind.  16,  319;  Rosemann,  Chem.  Ztaxtr.  1895, 
ii.  998 ;  Bettinck,  Pharm.  Weekblad,  54,  413). 
It  has  also  distinct  action  on  plants  (Grafe  and 
Richter,  Botan.  Zentr.  119,  423). 

Acetylene  explodes  very  violently  when 
mixed  with  oxygen  or  air  in  any  jiroportion 
from  3-82  p.c.,  l>ut  the  explosiveness  is  reduced 
by  admixture  with  inert  gases  (Meyer,  Ber.  27, 
2764;  Le  Chatelier,  Compt.  rend.  121,  1144; 
Gr^haut,  Compt.  rend.  122,  832  ;  Berthelot  and 
Vielle,  ibid,  123,  523 ;  Bone  and  Cain,  Chem. 
Soc.  Proc.  1896,  176;  CJlowes,  J.  Soc.  Chem. 
Ind.  16,  90,  418,  701,  891 ;  Bundt,  Ber.  31,  5 ; 
Clowes,  Chem.  Soc.  Proc.  1896,  413  ;  Berthelot 
and  Vielle,  Compt.  rend.  128,  177 ;  cf.  also 
Del^pioe,  8th  Intern.  Congr.  Appl.  Chem.  4,  25, 
and  J.  Gasbel,  67,  66). 

It  has  been  proposed  to  use  acetylene  as  an    • 
explosive  for  bringing  down  material,  e.t/.,  coal 
in  large  pieces  (Sprengstoffe,  Waffen  und  Muni- 
tion, 9,  41). 

With  ozone  acetylene  is  violently  decom- 
posed (Otto,  Ann.  Chim.  Phys.  13,  166). 

Pyrogenetic  CondenstUiona. — On  heating  acety- 
lene it  undergoes  various  condensatious  which 


42 


ACETYLENE 


are  of  great  importance,  particularly  in  con- 
nection with  the  theory  of  gas  manufacture. 

Berthelot  foond  (Jahnsbericht  f.  Chem. 
1866,  616 ;  Ann.  Chim.  Phys.  [4]  9,  446,  469) 
that  on  leaving  acetylene  for  a  time  in  a  glass 
tube  heated  to  its  Boiteninff  point,  a  mixture  of 
solid  and  liquid  hydrocarbons  was  formed  in 
which  benzene  predominated : — 


CH 


CH 


/// 

OH          CH 

Ctf^       CH 

CH          iL" 

Ah       K 

CH 

^n/ 

(c/.  also  Haber,  Ber.  29,  2691).  It  therefore 
appears  probable  that  the  formation  and 
polymerisation  of  acetylene  play  an  important 
part  in  the  production  of  aromatic  hydrocarbons 
m  the  manufacture  of  coal-gas  (V.  B.  Lewes, 
Proc.  Roy.  Soc.  66,  90;  67,  394).  B.  Meyer 
and  his  co-workers  have  foimd  that  on  passing 
acetylene  through  a  tube  suitably  heatea  in  an 
elecmo  furnace  Gurge  quantities  of  tarry  products 
are  produced,  and  as  a  result  of  collecting 
sevenil  kilos  of  tar  they  were  able  to  isolate  and 
identify  some  23  products  identical  with  those 
occurring  in  ordmary  gas- tar,  over  20  p.c. 
being  benzene  (R.  Meyer  and  others,  Ber.  46, 
1609  ;  46,  3183  ;  47,  2766  ;  60,  422  ;  61,  1671). 
Bone  and  Coward,  however,  take  a  different 
view,  holding  that  the  main  gaseous  product 
at  hiffh  temperatures  must  be  methane  which 
may  dissociate  into  free  radicals,  CH  \  and  CH, : 
which  condense  together  in  various  ways  as 
the  gases  oool  down  (Chem.  Soc.  Trans.  93-4, 
1197). 

For  a  very  complete  discussion  of  the  subject 
see  'The  Pyrogenesis  of  Hydrocarbons,' 
Part  L,  E.  Lawson  Lomax;  Part  n.,  A.  E. 
Bunstan  and  F.  B.  Thole,  Joum.  Ind.  and  Eng. 
Chem.  1917,  879,  888 ;  Joum.  Inst.  Petroleum 
Technologists,  3,  36-120.  A  comprehensive 
bibliography  is  given  in  the  articles. 

At  temperatures  above  800^  or  so,  acetylene 
is  completely  decomposed  into  hydrogen  and 
free  carbon,  possibly  with  the  intermediate 
formation  of  methane : 

2C,H,=3C+CH4=4C+2H, 

(CJ.  Bone  and  Coward,  /.c.) 

This  method  has  beeia  patented  for  the 
production  of  pure  hydrogen,  the  finely  divided 
carbon  so  produced  having  a  considerable 
commercial  value  as  acetylene  black  (cf,  J. 
Boo.  Chem.  Ind.  178,  711;  18,  284;  20,  966; 
D6pierre,  ibid.  20,  890 ;  Frank,  Zeitsch.  angew. 
Chem.  1906,  1733). 

Thus  Morehead  (U.S.  Pat.  986489)  claims  a 
process  for  dissociating  acetylene  by  passing  it 
suddenly  into  a  chamMr  heated  to  at  least  dull 
redness.  Before  the  war  the  Carbonium  Co., 
at  Friedriohshaven,  had  a  factory  in  which 
compressed  acetylene  was  decomposed  by  means 
of  electricity  into  acetylene  black  and  hydrogen, 
the  latter  beins  used  for  the  Zeppelin  airships ; 
it  is  improbable,  however,  that  the  process  can 
compete  with  other  methods  for  the  production 
of  oneap  hydrogen  such  as  the  Messerschmidt 
rooesB  or  the  Frank-C^aro  method  (v.  Hy- 
oovf). 


Pictet(Eng.  Pat.  24266, 1910)  claims  the  pro- 
duction of  hydrogen  and  carbon  from  aoetylene 
by  allowing  it  to  flow  into  an  externally  heat'Od 
chamber  to  be  there  heated  until  dissociation 
takes  place,  that  part  of  the  conduit  through 
which  the  constituents  pass  being  cooled  so 
as  to  absorb  the  excessive  heat  produced  by 
the  reaction. 

Acetylene  bums  with  a  very  smoky  but 
brilliantly  white  flame  which  can  be  modified 
by  mixing  carbon  dioxide  with  the  gas,  the 
intensity  varying  with  the  concentration  of  the 
latter  (Alvisi,  Ann.  chim.  applicata,  6,  118). 
When  submitted  to  the  action  of  an  eleotrio 
discharge  at  ordinary  pressure  various  con- 
densation products  are  fomed  {cf.  Berthelot, 
Bull.  Soc.  chim.  [3]  4,  480;  Jackson  and 
Laurie,  Chem.  Soc.  Ftoc.  1906, 166  ;  Losanitsch, 
Monatsh.  29,  763 ;  Javitsohitsch,  ibid,  29,  1 ; 
29,  6 ;  Coehn,  Zeit.  f.  Elektr.  7,  681 ;  BiUitzer, 
Monatsh,  23,  199;  Schutzenberger,  Compt. 
rend.  110,  889). 

Owing  to  its  unsaturated  nature  aoetylene 
readily  enters  into  reactions  to  form  addition 
products.  It  adds  on  hydrogen  to  form 
ethylene  and  ethane : 

CtH,-^-H,=C,^| 
C2H|4~2H|=:CsH|s 

This  is  most  effectively  performed  with  the  aid 
of  nsflcent  hydrogen  in  the  presence  of  a  catalyst. 
Thus  Lane  (Eng.  Pat.  10724,  1911)  claims  the 
synthesis  of  ethylene  from  acetylene  and 
hydrogen  by  passing  them  over  a  heated 
catalyst  contained  in  a  series  of  tubes.  {Cf. 
also  Atterbury,  Eng.  Pat.  2961, 1898 ;  Wideen, 
Eng.  Pat.  9340,  1903 ;  Bouchard-Praceiq, 
Eng.  Pat.  6076,  1906.)  Karo  (D.  R.  P.  263160) 
claims  the  production  of  ethylene  from 
acetylene  and  hydrogen  using  as  a  catalyst  a 
mixture  of  at  least  one  metal  of  the  palladium 
or  platinum  group  with  at  least  one  metal  of 
the  following  series :  iron,  nickel,  cobalt, 
copper,  silver,  magnesium,  zinc,  cadmium,  or 
aluminium. 

B.  E.  Eldred  and  G.  Mersereau  (U.S.  Pat. 
1308777)  also  put  forward  somewhat  similar 
cleums,  the  catalyst  used  being  nickel  or  pal- 
ladium on  a  carrier  of  coke,  asbestos,  pumice, 
etc. ;  to  prevent  the  action  becoming  too  ener- 
getic the  gas  mixture  is  diluted  with  ^  to  |  its 
volume  of  carbon  dioxide  or  ethane. 

According  to  Paal  and  his  co-workers  acety- 
lene is  readily  reduced  to  ethylene  and  ethane 
by  hydrogen  in  the  presence  of  colloidal  platinum 
or  palladium ;  in  presence  of  palladium  practi- 
cally pure  ethylene  can  be  obtained,  the  rednction 
being  step-wise;  in  presence  of  platinum 
36-40  p.c.  of  ethane  is  produced  simultaneously 
(Ber.  43,  2684,  2692:  48,  276,  1196,  1202; 
46,  128  ;  Chem.  Zeit.  36,  60.  Cf.  also  de  Wilde, 
7,  363 ;  Sabatier  and  Senderen^,  Compt.  rend. 
130,  1669,  1628,  1761  ;  131,  40,  187,  267  ;  Bull. 
Soc.  chim.  [3]  25,  678). 

W.  Traube  and  W.  Passarge  (Ber.  49,  1692) 
describe  the  reduction  of  acetylene  directly  to 
ethylene  by  means  of  an  aqueous  solution  of 
chromous  chloride  ;  the  same  result  is  obtained 
if  powdered  zinc,  diluted  hydrochloric  acid  and 
a  small  quantity  of  chromous  chloride  be  used. 
No  ethane  appears  to  be  produced  under  such 
conditions.    The  reaction  may  be  carried  out 


ACSTTLENE 


4S 


tinder  pressuxe  (D.  R.  P.  287586;  U.S.  Pat. 
1179061). 

When  paased  over  variona  metallic  catalysts 
sach  aa  finely  xeduoed  nickel,  copper,  cobalt  or 
iron^  a  nuztoze  of  acetylene  and  nydrogen  may 
yield  Tariona  liquid  hydrocarbons  as  well  as 
ethylene  and  ethane:  in  particular  copper 
yieMs  a  |i:reenish  hydrocarbon,  *  Cnprene '  (q.v.) 
(C7UJ«,  as  also  does  nickel  (Sabatier  and 
Senderens,  Compt.  rend.  128,  1173;  130,  260, 
1559,  1628 ;  131, 187 ;  Morean,  ibid.  122,  7240 ; 
Alexander,  Ber.  32,  2381 ;  Erdmann  and 
Kothner,  Zeitscfa.  angew.  Chem.  18,  49 ;  Gooch 
and  Baldwin,  ibid,  22,  236). 

B^  passing  acetylene  oyer  the  kathode  of 
alkalme  lye  undergoms  electrolysis  ethylene  and 
ethane  are  formed  (Bifiitzer,  Monatsh.  23,  199). 

With  fuming  sulphuric  acid  acetylene  eives 
a  sulphonic  add,  the  potassium  salt  of  wnich, 
(GsH|),*(S04KH)4,  yields  phenol  on  fusion  with 
potash  and  distJlling  the  product  (Berthelot, 
Compt. rend.  127, 908 ;  12^,  333 ;  Ann.  Chim.  Phyn. 
[7]  17, 289 ;  Schroeter,  Ber.  31, 2189 ;  Muthmann, 
Ber.  31,  1880).  If  60  p.c.  fuming  sulphuric  acid 
be  nsed  the  chief  product  is  aceUddehyde 
disulphonie  add: 

OH  :CH+2HJ504t=(80,H),-CHCHO+H,0 

(Schroeter,  Muthmann,  2.c.).  Atterbury  (Eng. 
Pat.  1208,  1898)  claims  the  production  of  vinyl 
alcohol  by  jtassing  acetylene  into  hot  strong 
Bolnhoric  acid. 

When  led  into  fused  alkali  at  220''  acetylene 
is  completely  absorbed  and  hydrc^en  is  liberated. 
The  reaction  product  on  treatment  with  water 
siyes  alkali  acetate.  A  60  p.c.  yield  is  claimed 
bat  the  process  hardly  seems  of  commercial 
yalne  (Feuchter,  Chem.  Zeit.  38, 273).  It  reacts 
with  hypochlorous  acid  to  give  dichlor^iceialde- 
hyde, 

G  A+HGIO  =  CH01,-CH(0H), 

=  CHC1,CH0+H,0 

(Wittoif.  Chem.  Zentr.  1900,  iL  29). 

With  nitric  acid  nitroform  and  various 
complex  nitrogenated  substances  are  produced 
indudinff  an  explosive  substance  C^HiOsNf 
m.p.  78^  (Tustom  and  Mascaielli,  Gazz.  chim. 
itaL  31,  i.  461 ;  Masoarelli,  ibid.  33,  ii.  319). 

According  to  K.  J.  P.  Orton  (Eng.  Pat. 
126000)  a  good  yield  of  tetranitromethane  may 
be  obtained  from  acetylene  and  nitric  acid  bv 
passing  the  gas  into  90  p.c.  to  97  p.c.  acid, 
preferably  in  presence  of  a  small  quantity  of 
mercury,  at  about  40*  C,  adding  sulphuric  acid 
and  then  distilling  off  the  tetranitromethane 
formed. 

Water  forms  an  addition  product  at  low 
temperatures  and  under  pressure,  of  the  formula 
C^,-6H,0  (Villaid,  Compt.  rend.  120,  1262; 
Ann.  Chim.  Phys.  [7]  10,  396  ;  11,  360  ;  Berthe- 
lot, Compt.  rend.  128,  336 ;  Ann.  Chim.  Phys. 
[7]  17,  297;  Forcrand  and  Thomas,  Compt. 
rend.  125,  109).  It  does  not,  however,  combine 
with  water  directly  to  form  acetaldehyde  except 
in  the  presence  of  catalysts  such  as  salts  of 
cadmium,  magnesium,  zinc,  and  especially 
mercury  (Kutscherow,  Ber.  14,  1640;  17,  13; 
42,  2769;  Erdmann  and 'Kothner,  Zeitsch. 
angew.  Chem.  18,  48) : 

CH:CH+H0H  =  CH,:CH(0H)  ->  CH.CHO 


This  property  has  of  recent  years  given  rise 
to  many  important  developments,  as  acetalde- 
hyde can  be  readily  converted  into  most  diverse 
substances  such  as  alcohol,  acetic  add,  acetone, 
butadiene  and  so  synthetic  rubber,  etc.  (For 
further  details  see  aIdshyde.) 

When  mixed  with  gases  such  as  ammonia, 
sulphuretted  hydrogen,  &o.,  and  passed  through 
heated  tubes,  various  condensation  products 
are  formed  identical  with  those  oconrrinff  in 
coal-tar,  such  as  pyridine,  pynolB,  cmincwne, 
thiophene,  &c.  (Meyer  and  Tanzen,  Ber.  46, 
3183;  Meyer  and  Wesche,  Ber.  60,  422; 
Tschitschibabin,  J.  Buss.  Phys.  Chem.  Soc.  47. 
702),  whilst  a  60  p.c.  yield  of  acetonitrile 
uudier  certain  conditions  is  claimed  by  the 
Chem.  Fab.  Rhenania  (E.  P.  109983). 

According  to  Q.  Capellen  (Amer.  Chem. 
Abstr.  2,  1662)  and  0.  de  Coninck  (Bull.  acad. 
roy.  Bdg.  1908,  303)  thiophene  is  not  produdble 
direct  from  acetylene  and  sulphur;  a  good 
yield,  however,  of  thiophene  can  oe  obtained  by 
passing  acetylene  over  pyrites  heated  to  280^- 
310*'  (Steinkopf  and  Kircfahoff,  Annalen,  403, 
I ;  D.  R.  P.  262376  ;  Fr.  Pat.  446136  ;  Austr.  P. 
72291, 1916;  Eng.  Pat.  16810, 1912).  Tschitschi- 
babin (2.C.)  claims  to  obtain  a  purer  product 
from  sulphuretted  hydrogen  than  oy  Stemkopf 's 
method. 

According  to  the  Chemische  Fabrik  Rhenania 
fEng.  Pat.  109983)  thiophene  is  pjroduced  also 
oy  passing  acetylene  mixed  with  sulphuretted 
hydrogen  over  nickel  hydroxide  mixed  with 
cement,  or  better  over  partially  reduced  bauxite. 

On  treating  acetylene  with  hydrocyanic 
acid  {e.g.  by  treating  powdered  calcium  carbide 
and  potassium  cyanide  with  dilute  sulphuric 
add  and  evaporating  the  reddue)  a  6  p.c. 
yield  of  sucdmc  acid  is  obtained,  pointing  to 
the  intermediate  formation  of  succinic  nitrile : 

C,H,-^2HCN  =  (CHjCN),  -»  (CH.CGOH), 

(E.  Comanducd,  Chem.  Zdt.  36,  383). 

Hdnemann  (Eng.  Pat.  12366,  1913  ;  Fr.  Pat. 
468,397;    U.S.    Pst.   1134677)    describes     the  . 
production  of  propylene  by  passiog  a  mixture 
of  acetylene  and  methane  over  heated  contact 
substances: 

CH;CH-|-CH4  =  CHj-CH  :  CH, 

which  can  then  be  converted  by  circuitous  routes 
into  glycerine,  acetone,  &c.  A  yield  of  70  p.c. 
is  clauned  using  a  catalyst  consisting  of  platinum 
and  copper,  aluminium  or  magnedum  on  pumice 
at  100*-200°. 

By  allowing  acetone  or  its  homologues  to 
act  upon  the  alkali  compounds  of  acetylene, 
Z-methyl'btUenol  or  its  homologues  are  produced 
(Farbwerke  vorm  Fr.  Bayer,  D.  R.  P.  286770) : 

(CH,)^CO+CH,CHNa  -»  (CH,),C(OH)CiCH 

According  to  D.  R.  P.  280226  and  291186,  the 
same  result  is  obtained  by  allowing  acetone  and 
acetylene  to  interact  in  the  presence  of  alkali 
alcoholates.  {Cf.  also  1).  R.  F.  284764,  286920, 
289800.)  On  reduction  the  product  yields 
3-methyl-butenol  (D.  R.  P.  288271) : 

(CH,),C(OH)CH :  CH 

which  can  then  be  dehydrated  to  2- methyl 
butadiene  jisoprene)  and  polymerised  to 
synthetic  ruober. 

(Other  posdble  modes  of  obtaining  synthetic 


44 


AOETTLENEL 


nibber  from  acetylene  axe  described  by  Dreyfus 
in  Eng.  Pat.  17193,  1013  (void).) 

Campounda  with  mdau  and  metaUic  sake, 
A  characteristio  jpronerty  of  acetylene  and 
its  oongeneiB  is  their  aoility  to  form  additive 
compounds  and  substitution  products  with 
metals  and  metallic  salts.  When  heated  with 
sodium  part  of  the  hydrogen  is  replaced  yielding 
*odium  acettflide  and  carbide  C,HNa  and 
G,Na,  (Matignon,  Gompt.  rend.  124»  775 ;  169, 
769 ;  Skosarewsky,  J.  Buss.  Phys.  Chem.  Soc. 
36,  863  ;  Moissan,  (bid.  126,  302  ;  de  Forcrand, 
Bull.  Soc.  chim.  [3]  13,  996).  The  sodium 
compound  reacts  with  alkyl  iodides  in  liquid 
ammonia  at  —60^  to  —30®  to  form  homologues 
of  the  acetylene  series  (Lebeau  and  Picon, 
Gompt,  lend.  156,  1077 ;  cf.  also  Moissan,  ibid. 
127,  913). 

Similar  compounds  are  known  with  lithium, 

gotassium,  caesium  and  rubidium  (Moissan, 
ompt.  rend.  122,  362 ;  Gunz.  ibid.  126,  1866 ; 
Bull.  Soc.  chim.  [3]  15,  756 ;  Gompt.  rend.  123, 
1273;  Moissan,  Gompt.  rend.  127,  911;  126, 
302 ;  137,  463  ;  136,  1217). 

Of  particular  interest  are  the  compounds  of 
acetylene  with  BJlver  and  copper  which  are 
formed  on  passing  the  gas  through  ammoniacal 
solutions  of  cuprous  or  silyer  salto ;  the  former 
compound  is  a  brick-red  precipitate  of  varying 
composition  and  is  used  as  a  test  for  the  presence 
of  the  gas ;  it  appears  to  have  the  composition 
GU|OtH,0  to  whion  Makowka  gives  the  structure 
Gu^-GHGHO  (Ber.  41,  SU).  On  heating 
gently  it  loses  water  yielding  Gu^G,.  Scheiber 
suggests  the  formulae: 

CH:GGu-Cu{OH),  and  G~Gu 

for     the    two   conipounds   (Ber.     41,    3816; 
Scheiber  and  Becklebui,  Ber.  44,  210). 

The  silver  compound  has  the  formula 
G^AgaHjO  or  GtH,-2Aff,0  and  forms  a  yellowish 
precipitate.  Both  the  copper  and  silver 
*  compounds  explode  on  heatmg  {cf.  Berthelot, 
Ann.  Ghim.  rhys.  [4]  9,  385 ;  Blochmann, 
Annalen,  173,  174;  Kuntsmann,  Bull.  Soc. 
chim.  [3]  6,  422 ;  Alexander,  Ber.  32,  2381 ; 
llosva,  ibid.  2697;  Phillips,  Amer.  Ghem. 
J.  16,  340;  Scheiber  and  Mebbe,  Ber.  41, 
3816;  Makowka,  Ber.  41,  824;  Freund  and 
Mai,  Ghem.  Zeit.  1899,  1,  410;  Berthelot, 
Gompt.  rend.  132,  1525 ;  Keiser,  Amer.  Ghem. 
J.  14,  285  ;  Noyes  and  Tucker,  Amer.  Ghem.  J. 
19,  125;  Kuspert,  Zeitsch.  angew.  Ghem.  34, 
453;  SUva,  Ghem.  Zeit.  36,  897;  Reckleben 
and  Scheiber,  Ghem.  Zeit.  40,  325). 

Acetylene  also  forms  double  compounds  with 
salts  of  copper  and  silver  some  of  which  are 
explosive,  e.g.  G,H,Gu,a,;  GtH,-20U|a,; 
G A'SGujGl, ;  G,H,-2Ag,0  ;  GuS0,-2Gu,C„ 
and  so  on.  {Cf,  Gluivastalon,  Gompt.  rend. 
124,  1364 ;  125,  245 ;  126,  1810 ;  127,  68 ; 
130, 1634, 1764  ;  131,  48  ;  132,  1489 ;  Hofmann 
and  Kuspert,  Zeitsch.  anorg.  Ghem.  15,  204 ; 
Soderbaum,  Ber.  30,  760,  814  ;  WUlgerodt,  Ber. 
28,  2107;  Arth,  Compt.  rend.  124,  1534; 
Berthelot  and  Del<^pine,  Gompt.  rend.  129,  369 ; 
Nieuwland  and  Maguire,  Amer.  Ghem.  J.  28, 
1025 ;  Edwards  and  Hoc^kinson,  J.  Soc.  Ghem. 
Ind.  23,  954;  25.  495;  British  Association 
Reports,    1904 ;     Alexander,    Ber.    32,    2381 ; 


Gooch  and  Baldwin,  Zeitsch.  anorg.  Ghem. 
22,  235  ;  Keiser,  I.e. ;  Manchot,  J.  Soa  Ghem. 
Ind.  30,  1302 ;  Bhaduri,  Zeitsch.  anorg.  Ghem. 
79,  355 ;  76,  419 ;  Llorens,  Anales  Soc  Espan. 
fis.  qnim.  ii,  320.) 

The  use  of  acetylene  has  been  suggested  as 
an  analytical  reagent  for  the  separation  of  metals 
such  as  silver,  copper,  palladium,  osmium,  gold, 
and  mercury  (Soderbaum,  Ber.  30,  760,  814, 
902,  3014;  Erdmann  and  Makowka,  Zeitsch. 
anal.  Ghem.  46,  128,  145;  Scheiber,  Ber.  41, 
3816;  Scheiber  and  Reckleben,  Ber.  44,  210; 
Llorens,  Anales  soa  Espan.  fis.  qoim.  10,  139 ; 
11,  320;  Weaver,  J.  Amer.  Ghem.  Soc.  36, 
2462). 

For  the  detection  and  estimation  of  acetylene 
use  is  made  chiefly  of  ammoniacal  cuprous 
chloride  solution.  Llorens  {l.c.)  recommends 
the  use  of  test  papers  soaked  in  a  solution  of 
copper  sulphate  and  sodium  chloride  decolorised 
with  sodium  bisulphite.  Weaver  (J.  Amer. 
Ghem.  Soc.  38,  352)  describes  a  colorimetric 
method  of  estimating  acetylene.  Schultae 
(Zeitsch.  ang^w.  Ghem.  29,  1,  341)  also  describes 
a  colorimetno  method.  (See  also  above  refer- 
ences on  use  of  acetylene  as  a  reagent.) 

With  aluminium  chloride  in  presenoe  of 
alcohol  double  compotmds  are  formed : 

Aia,'2GjH,H,0 ; 
AlGl,G,H,-2EtOH ; 
A1G1,G^,GH,0HH,0 

(Ganghoff  and  Henderson,  J.  Amer.  Ghem.  Soc. 
38,  1382;  39,  1420;  ef.  also  Band,  Ghem. 
News,  81,  286). 

With  magnesium  bromide  compounds  are 
formed  such  as  GH  i  GMgBr,  ( :  GMgBr.),  (Oddo, 
Atti.  R.  Acad.  Unoei.  13,  187 ;  Gaz.  chim.  itaL 
38,  i.  625 ;  Yocichi,  J.  Russ.  Phys.  Ghem.  Soc 
38,  1040). 

Action  on  magnesium,  see  Novak  (Ber.  42, 
4209)  and  Gottrell  (J.  Phys.  Ghem.  18,  85). 

The  compounds  of  acetylene  with  mercury 
and  mercuric  salts  have  been  studied  in  some 
detail,  and  are  of  considerable  importance  in 
view  of  the  use  of  mercury  salts  as  catalysts  for 
the  conversion  of  acetylene  into  aoetaldehyde. 
Mercuric  acetylide  (or  carbide)  itself,  G,Hg,  is 
obtainable  as  a  white  very  explosive  precipitate, 
by  passing  acetylene  through  Nessler  solution 
(Keiser,  ijner.  (jhem.  J.  15,  535) ;  on  treatment 
with  acids  acetylene  is  evolved.  A  hydrate, 
3G|Hg'H,0,  is  known  also  (Plimpton  and 
Travers,  Trans.  Ghem.  Soc.  65,  226).  A  hydriftte 
of  mercuro-acetylide,  GaHg,'H,0,  is  formed  as 
a  grey  precipitate  on  passing  acetylene  through 
an  aqueous  suspension  of  mercurous  acetate  in 
the  dark  (Burls^rd  and  Travers,  Trans.  Ghem. 
Soc.  81,  1270).  Mercuric  acetate  solution 
yields  a  slimy  white  precipitate  of  3G.Hg*2Hg0* 
2H.0  (possibly  3G,Hg'2Hg(OH),),  which  is  not 
explosive  and  yiel<u  acetaldehyde  but  no 
acetylene  on  treatment  with  acids  (Bnrkard  and 
Travers,  l.c. ;  Plimpton,  Proc.  Ghem.  Soc.  8, 
109). 

By  the  action  of  acetylene  on  aqueous  mercuric 
chloride  solution  an  amorphous  white  precipitafee 
is  formed  to  which  the  formula  GsUg'HeGlt 
was  first  given  (t.e.  Bis-chlormercuri-acetyleiie 
GlHg'G:G*HffGl),  but  which  appears  in  reality 
to  TO  tricklormcrcuri-acciaWinyde  (ClHg),: 
GGUO*     (Keiser,    Amer.   Ghem.  J.    15,  58?'; 


ACETYLENE, 


45 


BigioeDi,  Oieni.  Zentr.  189S,  i.  926 ;  Hofmann, 
Ber.  31,  2212,  2783;  32,  874;  37,  4409;  88, 
663 ;  BUto  and  Mumm,  Bw.  37,  4417  ;  38, 133 ; 
Annalen,  404,  219 ;  Brune,  Tnns.  Ghem.  Soo. 
87»  427).  On  hunting  an  aqueous  suspension 
of  the  compound  it  is  deoompoeed  yielding 
aoetaldehyde  in  praotioallj  quantitatiye  yield 
(Kntselierow,  Ber.  14,  1640 ;  17,  13 ;  Erdmann 
and  Koihner,  Zeitach.  anorg.  Chem.  18,  48; 
cf.  also  Hofmann  and  others,  swpra ;  B6hal.  Ann. 
Ghim.  Phys.  [6]  15, 267).  Aoconling  to  Hofmann 
the  compound  has  the  structure : 

a-Hg        a 

0-0 


01— Hg    Hg    01 


and  1b  formed  by  the  addition  of  two  mclecules 
HgOl,  to  one  of  HgO, ;  it  is  then  split  up  by 
water: 

(ClHg)t=C-C=01,+2HCl+H,0 

»  3%Cls+0Ht'0HO 

More  leeently  Obapman  and  Jenkins  have 
shown  (Trans.  Chem.  Soc.  115,  847)  that  on 
passing  acetylene  into  a  saturated  solution  of 
merourio  cUoride  in  absolute  idcohol  a  large 
yield  of  a  white  ciystalline  addition  j^oduot  is 
obtained  which  is  readily  soluble  m  ether, 
benaene,  and  other  organic  solvents.  It  has  the 
composition  BM.'C^^  and  melts  at  US'"  0. 
Chapman  and  JenRins  suggest  its  formula  may 

OlHg-OH :  OHOl  or  OlHG-^HOl 

and  it  seems  probable  that  this  body  may  be 
the  first  product  formed  during  the  action  of 
acetylene  upon  aqueous  solutions  of  mercuric 
salts.  When  passed  mto  alcohol  in  the  pre- 
sence of  a  mecouiy  catalyst  acetal  is  formed 
{v.  AosTAUB),  and  with  anhydrous  acetic  acid 
ethyUdene  diacetate  is  formed  which  can  be 
readilv  split  up  into  sidehyde  and  acetic 
anhy<mde  (t*.  Acbtals).  (See  also  Hofmann 
and  Eiimreuther,  Ber.  41,  314 ;    42,  4232.) 

Acetaldehyde  is  also  formed  to  some  extent 
by  heating  diarcoal  saturated  with  acetylene 
to  350^  with  water  (Degrez,  Ann.  Chim.  Fhys. 
[7]  3, 216).     (For  details  see  Aldehyde.) 

OzidiBing  agents  convert  acetylene  to  acetic 
add ;  thus  hydrogen  peroxide  (Cross,  Bevan  and 
Heibeig,  Ber.  33,  2015)  and  fused  caustic  alkali 
(Feuchter,  Chem.  Zdt.  38,  273)  yield  acetic 
acid  or  its  salts. 

Various  processes  have  been  patented, 
notably  by  the  Farbwerke  vorm.  IV.  Bayer,  to 
obtain  acetic  acid  direct  from  aceWlene  without 
isolating  the  aoetaldehyde  formed  as  an  inter- 
mediate product.  This  process,  described  in 
U.S.  Pat.  1128780,  claims  the  i>roduction  of 
acetic  add  by  treating  acetylene  with  a  mixture 
formed  from  merourio  oxide,  hydrogen  peroxide 
and  ammomnm  or  potassium  persulphate  in 
10  to  80  p.a  sulphuric  add.  fV.  Pat.  467515, 
describing  the  same  process,  states  that  10  8 
grams  acetylend  yield  24>25  grams  pure  acetic 
acid.  Pr.  Pat.  467778  (D.  R.  P.  293011  ;  U.S. 
Pat.  1150376)  describes  an  electrolytic  process 


using  30  p.a  sulphuric  acid  containing  about 
1-2  p.c.  of  a  meiouiv  salt  at  30''  to  4U^  with  a 
divided  cell  using  a  lead  or  oopper  cathode  and 
oxidising  the  acetylene  at  the  platiinnm  anode ; 
using  a  current  of  48*5  grams  acetylene  per 
hour  with  100  amps,  the  yield  is  stated  to  be 
0*5  kg.  acetic  acid  per  litre  in  24  hours. 

A  different  process  is  given  by  the  Chem. 
Fabrik  Griesheim  Elektron  (Swiss  Pat.  70152 ; 
Eng.  Pat.  14113,  1914),  consisting  in  passing 
acetylene  and  oxygen  altexnately  or  simul- 
taneously into  acetic  or  other  organic  acid  con- 
taining water  to  which  a  suitable  mercury 
catalyst  has  been  added.  It  does  not  appear, 
howeyer,  to  offer  much  advantage  over  the 
methods  inydving  the  previous  isolation  of  the 
acetaldehyde. 

HaLOOSM  DlBZYATITES. 

Iodine  Compoiinds.— Acetylene  unites  with 
iodine  somewhat  slowly  to  form  acetylene 
di-iodide  (sym.  diodoethylene)  Q^JL^^  which 
exists  in  two  stereoisomeric  forms,  a  solid, 
m.p.  73''  (or  78''  ?),  b.p.  IW  ;  and  a 
liquid  form,  m.p.— 2^,  b.p.  185^  D,o«3*00 
(Berthelot,  Annsien,  132,  122;  Sabanejew, 
Annalen,  178,  118  ;  216,  275 ;  Plimpton,  Trans. 
Chem.  Soc.  41,  391 ;  Patemd  and  Peratoner, 
Gaaz.  chim.  ital.  19,  580 ;  20,  670 ;  Bilts,  Ber. 
30,  1200,  1207 ;  Nef,  Annalen,  298,  841 ;  de 
Chalmot,  Amer.  Chem.  J.  19,  877 ;  Keiser, 
Amer.  Chem.  J.  21,  261 ;  Erdmann,  Ber.  38, 
237 ;  Ohayanne  and  Vos,  Gompt.  rend.  158, 
1582). 

With  alcoholic  potash  the  liquid  form  yields 
acetylene  and  di-todo-acetylene  C^Is;  duorine 
converts  it  into  the  tetrachlor  deriyatiye. 
Keiser  and  McMaster  haye  shown  (Amer.  Chem. 
J.  46,  518)  that  the  solid  form  can  be  made  to 
vidd  fumaric  acid  and  therefore  has  the  trans 
form,  whiUt  the  liquid  eta  form  yidds  maleio 
acid. 

Di'iodo-aeeiylene  0|lt  is  formed  on  treating 
calcium  carbide  with  a  solution  of  iodine  in 
potasdum  iodide,  tetraiodoethylene  beinff  also 
formed  (BUts,  Ber.  30, 1200) ;  or  by  the  action  of 
silyer  acetylide  on  an  ethereal  solution  of  iodine 
(Berend,  Annalen,  135,  258 ;  Baeyer,  Ber.  18, 
2276).  It  can  also  be  produced  from  tetra-iodo 
ethylene  (Nd,  Annalen,  298,  341 ;  Schenk  and 
Litzendonff,  Ber.  37,  345)  and  from  iodo- 
propiolic  acid  fNef,  Annalen,  308,  325).  It  is 
Dest  prepared  oy  the  method  of  Biltz  {I.e.),  by 
leading  acetylene  into  2N  caustic  soda  lye  into 
which  a  solution  of  iodine  in  potasdum  iodide  is 
allowed  to  drip.  Thus  obtained  it  is  a  white 
amorphous  predpitate  which  crystallises  in 
needles  from  ligroin,  m.p«  82''.  It  is  an  evil- 
smelling  substance  with  pronounced  action  on 
the  mucous  membrane ;  it  has  strong  anti- 
septic properties  (Biltz  and  Ktippers,  Ber. 
37,  4416;  Mebert,  Archly,  f.  expenm.  Path., 
etc.  41,  114;  Low,  Chem.  Zentr.  1899,  1,  214). 
The  action  of  heat  or  actinic  rays  converts  it 
into  C1I4.  With  nitrous  fumes  it  yields  nuro- 
tri'iodo  ethylene  CI.  :  CINO.  (Meyer  and  Pemsd, 
Ber.  29,  1411 ;  Biltz  and  Werner,  Ber.  30, 
1200 ;  33,  2190 ;  Biltz  and  Kiippers,  l.c.  ; 
Chalmot,  Amer.  Chem.  J.  19, 877  ;  Net,  Annalen, 
298,  202). 

Magnesium  acetylene  iodide   is  known  and 


46 


A0ET7LENE. 


forms  a  thiok  oily  liquid  ( Yocichi,  J.  B1188.  Phys. 
Chem.  Soc.  38,  1040). 

Bromine  DerlvativeB.  Brom-aeetylene 
GBrjCH  is  formed  by  the  deoompoeition  of 
ethylene  dibromide  with  alcoholic  potash : 

GHBr :  GHBr— HBr  =  OBr :  GH 

It  condenses  to  a  colourless  liquid,  b.p.  about 
—2®.  Both  liquid  and  vapour  are  spontaneously 
inflanimable.  It  bums  with  very  great  energy 
in  air,  partially  carbonising  and  forming 
HBr,  GO.  and  GO^.  Its  solutions  show  phosphor- 
escence and  smell  strongly  like  phosphorus. 
In  daylight  it  polymerises,  about  10  p.c.  of  tiie 
product  being  aym.  tribrom-benzene  (Beboul, 
Annalen,  125,  81 ;  Sohmelz  and  Beilstein, 
Annalen,  Spl.  3,  280  (1865) ;  Sabanejew,  Ber. 
18 :  Ref.  374 ;  Nef,  Annalen,  298,  855 ;  308, 
325 ;  Gray,  Trans.  Ghem.  Soc.  71,  1029). 

Di-brom-acetykne  GBrjGBr,  is  formed  bv 
treating  tribromethylene  with  alcoholic  potash 
(Lemomt,  Gompt.  rend.  136,  55;  137,  1333; 
Lawiie,  Amer.  Ghem.  J.  36,  490).  It  forms  an 
oil  insoluble  in  water,  posseesinff  an  unpleasant 
isonitrile  odour,  b.p.  76^-77  .  It  is  very 
poisonous  and  is  spontaneously  inflammable. 
With  bromine  it  forms  tetra-brameihylene  G^Br^, 
and  with  iodine  it  forms  dibrom-diodoethylene 
BrG :  Git,  m.p.  95''-96^  Acetylene  itself  reacts 
with  bromine  to  form  acetykne  dibromide 
(dibromethylene)  GHBr :  GHBr,  using  dilute 
bromine  solutions  and  keeping  the  acetylene  in 
excess;  the  product  is  a  colourless  liquid, 
b.p.  110®,  Dn=2'271.  It  is  aJso  produced  by 
the  action  of  zinc  and  alcohol  or  amalgamated 
sine  on  acetylene  tetrabromide  (Sabanejew, 
Annalen,  178,  115;  216,  251,  267;  Ber.  18; 
Ref.  374 ;  Weger,  Annalen,  221,  72 ;  Anschutz, 
ibid.  221,  141 ;  Moureau,  Bull.  Soa  chim.  [31 
21,  99;  Elbe  and  Newmann,  J.  pr.  Ghem  [2] 
58,  246;  Swarts,  Ghem.  Zentr.  1899,  1,  589; 
Gray,  71,  1023).  Van  de  Walle  (BuU.  Soc. 
chim.  Belg.  27,  209)  has  shown  that  acetylene 
dibromide  prepared  by  the  reduction  method 
consists  of  a  mixture  of  two  isomers  which  can 
be  separated  by  the  fractional  distillation  of  the 
binary  mixtures  with  ethyl  alcohol.  The  two 
forms  have  m.p.  —6*5®  and  —53®,  and  the 
equilibrium  mixture  consists  of  about  one  part 
of  the  former  and  two  parts  of  the  latter. 

If  acetylene  be  treated  with  excess  of  bromine 
the  tetrabrom  derivative  is  formed,  G|HtBr4 
(acetylene  tetrabromide,  tetrabrom  ethane) 
(Reboul,  Annalen,  124,  269;  Sabanejew, 
Annalen,  178,  112,  121 ;  216,  255 ;  Bourjoin, 
Ann.  Ghim.  Phys.  [5]  4, 423 ;  Anschutz,  Annalen, 
221,  138 ;  Wojzic,  Ber.  16,  2891 ;  Grossley, 
Proc.  Ghem.  Soc.  14,  248 ;  Hofmann  and 
Kirmreuther,  Ber.  41,  314 ;  Elbe  and  Newman, 
J.  pr.  Ghem.  [2]  58,  245;  Muthmann,  Zeitsch. 
f.  &v8taUographie,  30,  73).  An  unsymmetrical 
tetrabrom  ethane  is  also  known  (Lennox, 
Annalen,  122,  124 ;  Sabanejew,  Annalen,  216, 
255  ;  Anschutz,  Annalen,  221,  140). 

Perbrom-ethylene  G^Br^  forms  colourless 
crystals  of  m.p.  56®,  b.p.  226®-7®,  and  is  prepared 
either  by  the  addition  of  bromine  to  dibrom- 
acetylene  (v.s.)  or  b^  the  action  of  bromine  on 
an  aqueous  suspension  of  silver  aoetylide,  and 
by  distilling  hexabromethane  (Lowig,  Pogg. 
Ann.  16,  377;  Lennox,  Annalen,  122,  126; 
Reboul,  Annalen,  124,  271 ;    Merz  and  Weith, 


Ber.  11,  2238;  Holand,  Annalen,  240,  237; 
Nef,  Annalen,  298,  332 ;  Biltz,  Ber.  35,  1530). 
By  the  action  of  sodium  ethylate  tetrabrom 
ethylene  yields  asymm.  dibrom-vinyl  ether, 
bromacetio  ester,  tribromvinyl  ether,  and 
aldehyde  resin  (Nef,  Annalen,  298,  334). 
Fuming  nitric  acid  oxidises  it  to  tribrom-acetic 
acid,  or  in  presence  of  cone,  sulphuric  add 
tribrom  acetyl  bromide  is  formed  (Biltz,  Ber. 
35,  1536). 

Various  mixed  halogen  compounds  derived 
from  acetylene  are  also  known  out  are  of  little 
importance. 

Chlorine  DerivatlvflB.— Owing  to  the  cheap- 
ness of  chlorine  its  compounds  with  acetylene 
are  easily  and  economically  produced,  and 
constitute  an  important  tecnmcal  application 
of  acetylene. 

Chlar-aceiylene  GQl  GH  is  a  aas  with 
explosive  properties  (Wallach,  Anniuen,  203, 
88 ;  Zincke,  Ber.  23,  3783 ;  V.  Meyer,  Bar.  23, 
3783;  Hofmann  and  Kirmreuther,  Ber.  42, 
4232 ;  Mourelo  and  Banus,  Analee.  soc.  Espan. 
fis.  qnim.  9,  84). 

DiMor-aceiylene  GGljGGl  has  been  obtained 
by  Boeseken  and  Garri^,  (Verslag,  Akad. 
Wetenschappen,  22,  1186)  by  heating  the 
barium  salt  of  trichloracrylic  acid : 

Ba(GGla : GClGOO),=BaGl,+2GO,+2GGl i  OCl 

It  is  a  colourless  gas  with  an  unpleasant  odour ; 
it  can  be  condensed  to  a  colouriess  liquid,  m.p. 
—50®,  which  is  explosive.  Mixed  with  nydrocen 
it  inflames  spontaneously  in  the  air.  It  is  uso 
possible  that  dichloracetylene  is  formed  to 
some  extent  when  caldnm  carbide  is  treated 
with  chlorine  (Davidson,  Amer.  Ghem.  J.  40, 
397).  For  instance,  l^  treatment  of  benzene 
with  powdered  calcium  carbide  and  chlorine, 
tolane  dichloride  is  formed,  a  reaction  beet 
explained  by  the  intermediate  formation  of 
diohloracetyfene ;  direct  evidence  was  also 
obtained  that  the  gas  is  formed  under  these 
conditions. 

Acetylene  tetrachloride  (tetrachlorethane) 
GHGlt'GHGlj  is  the  most  important  halogen 
derivative  o!  acetylene  from  a  technical  point 
of  view,  as  it  is  the  direct  product  of  the  action 
of  chlorine  on  acetylene  and  is  the  starting 
point  for  numerous  other  derivatives.  Ghlorine 
IS  without  action  on  acetylene  in  the  pure  state 
and  in  the  absence  of  light  (Schlegel,  Annalen, 
226,  154).  In  diffused  dayUght  the  dichlor- 
and  tetraohlor  derivatives  are  formed  in 
succession: 

G,H,+G1,  =  G,H,G1,    GJH,a,+Gl,  =  G^H^Gl^ 

(Bomer,  Annalen,  233,  214).  Traces  of  impuri- 
ties, particularly  air  (Mouneyrat,  Bull.  Soa 
chim.  [3]  19,  447,  452,  454),  cause  violent 
explosive  decomposition  during  the  reaction, 
with  formation  of  free  carbon  and  hydrochloric 
acid: 

G,H,-f  Gl,  =  2G+2Ha 

To  avoid  this  daneer  and  to  render  the  reaction 
safe  and  dependable,  various  devices  are 
adopted  chieflv  depending  upon  the  presence  of 
suitable  catalysts,  such  as  iodine  chloride 
(Sabanejew,  Annalen,  216,  241,  262),  antimony 
pentachloride  (Berthelot  and  Jungfleiscb, 
Annalen,  Suppl.  7,  252  (1870)),  aluminium 
chloride    (Mouneyrat,  Bull.  Soc.  chim.  [3]  19, 


ACETTLENE. 


47 


448  ;  Compt.  raid.  120,  180S).  For  this  reaaon 
most  of  the  early  patents  on  the  subject  deal 
with  methods  for  ayoidin^  the  danger  of  ex- 
plosion during  the  reaction  and  effecting  a 
smooth  and  oontinaous  combination  of  the 
gases.  The  following  processes  may  be  noted : 
Aakenasy  and  Mugdan  (Eng.  Pat.  18602,  1904) 
prepare  the  S3rm.  tetraehlorethane  by  passing 
acetylene  and  chlorine  alternately  into  anti- 
mony pentachloride,  which  latter  should  be  free 
from  excess  of  chlorine  and  may  be  diluted  with 
tetraehlorethane;  or  the  two  gases  may  be 
dziyen  in  simultaneonsly  into  two  halyes  of  a 
Teasel  separated  by  a  perforated  diaphragm. 
H.  K.  Tompkins(£ng.  Pat.  19568,1904)  adyocates 
the  ose  of  a  mixture  of  antimony  tri-  and 
pentaohloiide  at  40^  to  60^  and  distilling  the 
product ;  the  reaction  appears  to  be 

C,H,-fSbCa,=C,H,-Sbag 
CtH,-8  bCa  ,+ 8ba,= CjHjCa^  -f  28bCl, 

G.  I>reyfus,  H.  K.  Tompkins,  and  the  Clayton 
Aniline  Go.  (Eng.  Pat.  8438,  1909)  describe 
the  prodnction  of  antimony  chloracetylide  by 
passing  acetylene  into  antimony  pentMhloride. 
The  use  of  antimony  chlor-  or  brom-aoetylides 
is  claimed  by  Dreyfus,  Tompkins,  and  the 
Clayton  Aniline  Co.,  sa  a  catalyst  for  use  in  the 
production  of  halogen  indigos  and  thioindigos 

J.  M.  Lidholm  (Eng.  Pat.  22094, 1906)  reoom- 
mends  diluting  the  gases  with  an  indifferent  gas 
snch  as  carbon  dioxide  and  exposing  the  mixture 
to  actinic  rays.  Chemische  Fabnk  Griesheim 
Elektron  (Eng.  Pat.  13411,  1907)  claim  the  pro- 
duction of  tetraehlorethane  by  mixing  the 
reaotinj;  gases  with  solid  diluents  such  as  sand, 
infusonaf  earth,  clay,  &c.,  and  exposing  to 
aotinio  rays  in  presence  of  the  solid.  After  the 
gases  haye  been  mixed  they  may  be  passed  into 
Squids  such  as  the  chlorides  of  antimony  or 
Bclntions  of  these  in  the  tetrachlor  compound. 
G.  Omstein  (Eng.  Pat.  2376,  1911)  also  adyises 
the  use  of  a  non-yolatile  catalyst  such  as  iron. 
Salzbergwerk  Neu  Stassfiirth  (D.  R.  P.  174068) 
suggest  the  use  of  sulphur  chloride  to  which  a 
small  amount  of  iron  has  been  added.  The 
Consortium  f.  Elektroohemische  Industrie  (Eng. 
Pat.  26967,  1910)  daim  that  ferric  chloride  is 
an  efficient  catalyst ;  it  is  possible  that  the  two 
preceding  patents  also  depend  on  the  formation 
of  ferric  chloride  as  the  zeal  catalytic  agent. 
{Of.  also  £.  P.  132767,  Soc.  d.  prod.  chim. 
d'Alais.) 

In  practice  the  use  of  antimonypentaohloride 
appears  to  find  most  fayour.  Tne  apparatus 
used  consists  of  a  yessel  fitted  with  a  sturer  and 
diyided  by  a  partition  which,  howeyer,  allows 
the  intermixing  of  the  liquids.  The  yessel  is 
partially  filled  with  a  solution  of  antimony 
pentachloride  in  tetraehlorethane  and  acetylene 
18  passed  into  one  side  whilst  chlorine  is  led  into 
the  other;  the  acetylene  compound  is  thus 
continuously  formed  m  the  one  chamber  and 


decomposed  by  the  excess  of  chlorine  on  comiiu^ 
into  the  other.  The  yessel  gradually  fills  with 
the  acetylene  tetrachloride  so  formed  until  a 
liquid  containing  as  little  as  1  p.c.  of  the  catalyst 
remains.  The  acetylene  is  then  stopped,  a 
small  amount  of  chlorine  is  added  to  decompose 
the  double  compound  and  the  tetrachlorioe  is 
distilled  off,  purified  with  lime  or  chalk  and 


distilled  in  steam.  The  yield  is  about  96  p.c. 
The  process  is  used  in  England  by  the  Weston 
Chemical  Co.,  in  Stance  by  the  Compagnie 
G^n^rale  d'Elektrochemie  de  Bozel,  Paris,  and 
in  Germany  by  the  Consortium  fiir  Elektro- 
ohemische Industrie  in  Numberg,  and  by  the 
Bosnisohe  Elektrizitats  A.G.  in  Jajce.  The 
Salzbergwerk  Neu  Stassfiirth  make  use  of 
Omstein's  process  using  iron  as  a  catalyst, 
tiiough  prooably  ferric  chloride  is  the  real 
agent. 

Acetylene  tetrachloride  forms  a  colourless 
liquid  of  b.p.  147*,  D.=  1'614,  m.p.  -36^ 
It  is  the  most  important  of  the  acetylene  halides 
as  it  is  the  mother  substance  of  a  large  number 
of  deriyatiyes  (v.  infra),  ISke  the  latter  it 
is  non-inflammable,  and  as  it  possesses  yery 
great  solyent  power  for  orgamc  substances, 
especially  fats,  yamishes,  &c.,  it  attained  to 
some  importance  in  industry.  It  is  a  good 
solyent  ior  sulphur,  phosphorus,  and  the 
halogens.  It  also  dissolyee  acetyl-cellulose  and 
was  used  for  this  purpose  under  the  name 
*Acetosor  (c/.  Lederer,  D.  B.  P.  176379; 
Walker,  U.S.  Pat.  1036108).  It  can  be  distilled 
unchanged  either  alone  or  with  steam,  and  does 
not  attack  metals  in  the  dry  state.  In  the 
presence  of  moisture,  howeyer,  certain  metals, 
notably  zinc  and  iron,  remoye  halogen  leaying. 
aoetylene  dichloride.  It  is  stable  to  strong 
acids  but  is  readily  attacked  by  alkalis  or 
magnesium  hydroxiae,  yielding  trichlorethylene. 
Heated  alone  or  with  AlClg  or  ThO,  trichlor- 
ethylene is  formed  slowly,  and  prolonged  heating 
causes  the  formation  also  of^  perchlorbenzene 
(Berthelot  and  Jungfleisch,  Annalen,  Suppl. 
7, 252  (1870) ;  Nicodemus,  J.  pr.  Chem.  83, 312). 

The  Salzbergwerk  N.  Stassfiirth  (D.  B.  P. 
186374)  recommend  the  addition  of  orgsnic 
compounds  such  as  turpentine  to  the  tetra-  * 
chloride  to  take  up  any  n^rdrochloric  acid  that 
may  be  formed,  thus  keeping  the  solyent  in  a 
neutral  condition  suitable  for  use.  A.  Schmitz 
(Fr.  Pat.  417649)  claims  the  production  of  emul- 
sions of  tetraehlorethane  with  soap  solutions. 

Owing,  howeyer,  to  the  strons  narcotic  and 
poisonous  action  of  the  tetrachK>ride,  causing 
jaundice,  fatty  degeneration  of  the  organs, 
albuminuria  and  hemoglobinuria,  its  use  as  a 
solyent  is  now  considerably  restricted,  particu- 
larly as  its  yarious  deriyatiyes  are  equally 
suitable  for  most  purposes  and  are  less  poisonous 
{cf.  Grimm,  Heffter  and  Joachimaglu,  Vrtljschr. 
Med.  Offent.  Sanitatsw.  48,  1 ;  Beport  of  H.M. 
Inspector  of  Factories,  1914). 

TricMoreihykne  C,HC1,  is  obtained  from 
acetylene  tetrachloride  by  heating  in  a  yat  with 
milk  of  lime  or  solid  lime  (Consort,  f.  Elektro- 
chem.  Ind.  D.  B.  P.  171900,  208864).  The 
yield  is  practically  quantitatiye.  It  is  also 
produced  oy  passins  ammonia  into  a  mixture 
of  acetylene  totracmoride  and  alcohol  (Tomp- 
kins, Eng.  Pat.  19668,  1904),  and,  admixed  with 
hexachlorbenzene,  by  passins  the  tetrachloride 
through  a  tube  heated  to  400^  or  600''  (Tompkins 
I  and  Qayton  Aniline  Co.,  Eng.  Pat.  23780, 1906). 
Another  process  by  the  Griraheim  Elektron  Co. 
(D.  B.  P.  263467)  consists  in  passing  the  yapours 
of  acetylene  tetrachloride  oyer  heated  metallic 
chlorides  such  as  copper  or  barium  chlorides ; 
it  is,  howeyer,  less  easy  to  obtain  a  pure  product 
by  this  method.     It  may  also  be  obtained  by 


48 


ACETYLENE. 


passing  the  tetrachloride  over  ThO,  heated  to 
a  temperatare  not  exceeding  890^  (Chem.  Fab. 
Buokau,  D.  R.  P.  274782). 

Trichlorethylene  forms  a  colourless  •liquid 
b.p.  85%  Do==l*47»  vbich  is  practically  im- 
miscible with  water.  It  has  sreat  solvent 
power  for  fats,  waxes,  resins,  rubber  and  other 
organic  products,  and  also  for  sulphur  and 
phosphorus,  on  which  account  it  is  used  on  a 
considerable  scale  for  fat-extraction  and  the 
like  in  place  of  benzene  or  carbon  tetrachloride. 
It  has  the  advantage  over  acetylene  tetra- 
chloride in  that  it  is  kss  toxic  (Chem.  Zeit.  31, 
1095;  32,  256,  529;  Arch.  Hyg.  1911,  74; 
Lach,  Seifensieder,  1911, 15).  Neumann  (Chem. 
Zeit.  35, 1025)  states  that  the  trichlor  compound 
gives  satisfactoiT  results  as  a  fat  solvent  (c/.  also 
van  Lennep  and  Buys,  Chem.  Weekblad,  9, 654). 
Soaps  containing  *  Tri '  (trichlorethylene)  such 
as  *  Westrol,'  '  Triol,'  *  Tripur,'  &o.,  are  used  for 
cleansing  textile  materials  from  grease  (c/. 
Schmitz,  D.  R.  P.  256901).  Trichloiethylene 
has  also  advantages  over  tetrachlorethane  in 
that  it  is  more  resistant  to  chemical  action,  is 
unattacked  by  dilute  acids,  or  by  alkalis  or 
lime,  and  is  practically  without  action  on  the 
common  metals  such  as  iron,  copper,  lead,  tin, 
or  zinc,  even  in  the  presence  of  moisture.  At 
room  temperature  it  oxidises  slowly  yielding 
oarbonyl  chloride^  hydrochloric  acid,  ana 
dichloracetyl  chloride  (Erdmann,  J.  pr.  Chem. 
85,  78;  Staudinger,  ibid,  85,  330).  Under 
suitable  conditions  it  can  be  made,  however,  to 
undergo  various  important  transformations ; 
thus,  Dy  heatinff  with  strong  alkali  glycolUc 
acid  is  formed  (Consort,  f.  Elektrochem.  Ind., 
D.  R.  P.  267878), 

CHa :  CC1,H-4K0H 

=  CH,(0H)C00K+3Ka+H,0 

Traces  of  dichloraoetylene  are  also  formed.  On 
passing  through  a  heated  tube  it  is  partly 
converted  into  hexachlorbenzene  (Nicodemus,  J 
pr.  Chem.  83,  312).  In  the  presence  of  catalysts 
chlorine  is  added  on  with  the  formation  of 
pentachlorethane  (v.  infra).  On  heating  with 
sodium  ethylate  or  a  mixture  of  caustic  soda 
and  alcohol,  dichlorvinyhther  (dichlorethoxy- 
ethylene)  is  formed  (Tompkins,  Eng.  Pat.  678, 
1906 ;  Imbert,  Eng.  Pat.  5014,  1907),  which  on 
further  treatment  with  water  or  alcohol  readily 

gives  chloracetic  ester  in  good  yield  (Tompkins, 
iid.) 

aHa,+Na0C,H5=NaCl+C,HCl,0C,H, 

0jaLa,oc,H,+H,o=Ha4-acH,cooc,H, 

Aocordinff  to  Imbert  (Eng.  Pat.  5013, 1907)  heat- 
ing the  cuohlorethoxy  ethylene  with  the  theo- 
retical quantity  of  water  yields  the  chloracetic 
ester,  whilst  excess  of  water  vields  chloracetic 
acid  directly.  Chloracetic  add  or  its  ester  react 
readily  with  aniline  yielding  phenylglycine 
whioh  can  be  converted  into  indigo,  tnereby 
offering  an  alternative  route  to  the  usual 
process  starting  from  acetio  acid  (cf,  Chem. 
Zeit.  35, 1053). 

LtAer  processes  claim  the  production  of 
monocfaloracetio  acid  in  good  yields  bv  the  use 
of  concentrated  sulphuric  acid  at  U(r-20(f  C, 
as  the  hydrating  agent  (L.  V.  Simon  and  G.  C. 
Chavanne,  Eng.  Pat.  129301),  100  gms.  trichbr- 
ethylene  under  such  conditions  affordine  57  gms. 


monoohloraoetic  acid ;  the  Soc.  des  prod.  ohim. 
d'Alais  also  describe  a  continuous  process  lor 
producing  the  acid  from  trichJoreUiylene  by 
allowing  the  Utter  to  act  upon  sulphuno  acid  of 
90  p.c.  concentration  at  160''-200"  0.,  water 
being  added  continuously  as  required  and  the 
resoltanb  monochloracetic  acid  bemg  carried  off 
by  the  excess  of  trichlorethylene  (Eng.  Pat. 
132042). 

DicUorvinyl  ether,  b.p.  128'2%  I>io=»l'08, 
is  an  extremely  reactive  substance  opening  the 
way  for  a  numloer  of  interesting  oceanic  syntheses. 
Thus  hydrochloric  acid  or  duorine  add  on 
directly  and  the  products  on  distillation  split 
up  into  chlor-  or  diohlor-aoetyl  chloride : 

C,HCl,0C,H5-fHCl  =  C,H,C1,-00,H5 

=  CaC,H5+ClCH,-C0Cl 

(cf.  Tompkins  and  Clayton  Aniline  Co.,  Eng. 
Pat.  5404,  1908).  Chloracetyl  chloride  made  by 
this  orocess  has  been  placed  on  the  market  by 
the  (Consortium. 

A  further  use  for  trichlorethylene  la  given 
in  Eng.  Pat.  90, 1908,  bv  the  Badische  Anilin  und 
Soda  Fabrik,  in  which  by  treating  trichlor- 
ethylene with  a  salt  of  thiosalicylic  add,  omega- 
cJUorovinyUhiosalicyHc  acid  is  ^produced  which 
can  be  readily  converted  mto  thioindiffo. 
With  mercuric  cyanide  trichlorethylene  yiekls 
mercuritrichhrethylerUde  Hg(CCl :  (XJl),  (Hof- 
mann  and  Ejnnreuther,  Ber.  41,  315). 

Dichhroeihylene  (3|HgCL  is  prepared 
technically  from  tetrachlorethane  by  refluxing 
with  zinc  dust  and  water : 

CJB[,a4-f  Zn  =  C,H,Cl,+ZnCl, 

(Askenasy  and  Mugdan,  Eng.  Pat.  19576,  1907). 
Aluminium  or  iron  powders  may  also  be  used 
instead  of  zinc,  but  m  that  case  require  heating 
to  140°  in  an  autoclave.  The  diohloride  may 
also  be  prepared  by  the  direct  union  of  aoetvlene 
and  chlorine,  avoiding  any  excess  of  the  latter 
and  using  antimony  pentachloride  as  a  catalyst 
(Tompkins)  Eng.  Pat.  19568,  1904),  or  diluting 
the  gases  and  exposing  to  actinic  rays  (Lidholm, 
Eng.  P.t.  22094, 1905),  or  by  heating  the  f^ases  to 
160°  in  capillary  tubes  (Chem.  Fab.  Gnesheim 
Elektron,Efn^.  Pat.  16620, 1912).  The  commercial 
product  consists  of  a  mixture  of  the  two  stereo* 
isomers  of  b.p.  48°  and  60°  respectivdy,  and 
densities  1*265  and  1-291,  in  consequence  of 
which  it  has  no  constant  boiling-point  ((Jhavanne, 
Compt.  rend.  154,  776 ;  Bull.  Soc.  chim.  Bdg. 
26,  287;  28,  234).  The  equilibrium  mixture 
contcuns  about  four  parts  '  ds  *  form  (b.p.  60°) 
to  one  part  *  trans  *  (b.p.  48°)  form.  Askenasy 
and  Mugdan  (Zeit.  f.  Elektrochemie,  15,  773) 
suggest  the  production  of  the  dichloride  by 
dectrolysing  the  tetrachloride  in  zinc  chloricfe 
solution,  the  zinc  being  regenerated  electrolyti- 
cally. 

iHchlorethylene  resembles  trichlorethylene 
and  perohlorethylene  and  is  unattacked  by 
metals  or  alkalis.  It  can  be  used  as  a  rubbw 
solvent  (Fischer,  D.  R.  P.  211186)  and  owing 
to  its  low  boiling  point  has  been  recommended 
as  a  substitute  for  ether  for  fat  extraction,  &c. 
Its  vapour  is  inflammable  but  the  flame  is 
readily  extinguished.  (For  other  details  see 
also  Berthelot  and  Jungfleisch,  Annalen,  Sppl. 
7,  253  (1870) ;  Sabanejew,  Annalen,  216,  262.) 

Pentachlorethane    CjHClj    is     prepared    by 


ACETYLENE 


49 


r«—i"g  chlorine  into  triohlorotliylene,  preferably 
in  the  presence  of  aotinic  rays,  from  which  it  is 
formed  in  almost  quantitative  yield;  after 
washing  with  water  and  lime  to  remove  excess 
of  chlorine  it  is  distilled  in  steam  and  forms  a 
Uqnid  b.p.  169^,  D=  1  '685,  and  in  other  respects 
closely  resembles  tetrachloretbane  (Salzbemrerk 
Nea  Stassforth,  Eng.  Pat.  1106,  1912).  ft  has 
somewhat  similar  solvent  powers  to  the  tetra- 
chlor  compound,  and  is  also  very  sensitive  to 
alkalis,  yielding  perchlorethvlene  C.CI4.  It 
does  not  attack  metals  in  a  dry  state  out  does 
so  in  the  presence  of  moisture.  (For  other 
methods  of  preparation  see  Begnault,  Annalen, 
33,  321 ;  Piene,  Annalen,  80,  130 ;  Patem6, 
Annalen,  151,  117  Mouneyrat,  Bull.  Soc.  chim. 
[3]  19,  261.) 

Perehlcreihylene  (tetraohlorethylene)  GSGI4: 
is  prepared  by  treatihg  pentachlorethane  with 
milk  of  Ume;   b.p.  119%  D==  1*624.    Its  other 

rtroperties  are  similar  to  those  of  trichlorethylene. 
t  ooes  not  attack  metals  even  in  a  moist  state 
and  is  stable  to  alkalis.  It  has  a  certain 
limited  use  as  a  deaninp;  agent  for  textiles.  It 
is  also  a  by-product  m  the  manufacture  of 
carbon  tetrachloride  (e/.  Faraday,  Ann.  Chim. 
Phvs.  [2]  18,  63 ;  Bej^ult,  Annalen,  33,  326, 
333;  Geuther,  Annalen,  107,  212;  111,  176; 
Ftndhomme,  Annalen,  156,  342 ;  Schiff, 
Annalen,  220,  97 ;  Burgoin,  Ann.  Chim.  Phys. 
[5]  6,  142;  Geuther  and  Fischer,  Zeitsch.  f. 
Chemie,  1864,  269 ;  Geuther  and  Brockhoff,  J. 
pr.  Chem.  [2]  7,  102;  Goldschmidt,  Ber.  14, 
929 ;  V.  Mmrer,  Ber.  27,  3160 ;  Besson,  Compt. 
rend.  118,  1347 ;  Mouneyrat,  Bull.  Soc.  chun. 
[3]  19,  182;  Bntz,  Ber.  36,  1529).  Heating 
with  fumioff  sulphuric  acid  yields  tnchloraoetic 
acid  (Prudnomme^  Zeitsch.  f.  Chemie.  1870, 
380 ;  Bntz,  Ber.  36,  1633). 

Hexaehhrethane    (Perchlorethane)  C|Clc    is 

groduced  by  exhaustive  phlorination  of  the 
nwm  chlorinated  ethane  derivatives  (c/.  Fara- 
day, Ann.  Chim.  Phys.  [2]  18,  48 ;  Biegnault, 
Und.  69,  166 ;  Annalen,  33,  323 ;  Hubner  and 
Muller,  Zeitsoh  f.  Chemie,  1870, 328 ;  Mouneyrat, 
Bull.  Soo.  chim.  [31  17,  797 ;  19,  454 ;  iM.  [3] 
17,  794;  Michel,  Zeitsch.  angew.  Chem.  19, 
1096).  It  is  also  formed  on  passing  chloroform 
through  a  red-hot  tube  (Rsnis^  and  Toung, 
Jahr.  d.  Chemie,  1886,  628).  ft  occurs  as  a 
bv-product  in  the  production  of  carbon  tetra- 
chloride (V.  Meyer,  Ber.  27, 3160),  and  is  formed 
from  carbon  tetrachloride  by  heating  to  160^ 
with  amorphous  arsenic  (Auger,  Compt.  rend. 
146,  809),  or  by  passing  through  a  heated  tube 
(Kolbe,  Annalen,  64,  147). 

It  iB  formed  readily  by  refluxing  carbon 
tetrachloride  with  aluminium  amalgam  (Hof- 
mann  and  Seiler,  Ber.  38,  3058),  and  is  slso 
formed  by  direct  synthesia  if  an  electric  arc  be 
formed  in  a  chlorine  atmosphere  {v.  Boltom, 
Zeitsch.  f.  Elektrochemie,  8,  169;  9,  209; 
Lorenz,  Annalen,  247,  245;  Zeitsch.  angew. 
Chem.  6,  313  ;  Zeitsch  f.  Elektrochemie,  8,  203). 
On  a  commercial  scale  it  can  be  conveniently 
prepared  by  the  exhaustive  chlorination  of 
acetylene  tetrachloride  in  the  presence  of 
aluminium  chlbride  (c/.  Mouneyrat,  l,c.).  The 
Sakbogwerk  Neu  Stassfiirth  (D.  B.  P  174068) 
claim  the  production  of  the  hexachlor  compound 
by  leading  acetylene  and  chlorine  alternately 
into  a  heated  mixture  of  sulphur  chloride  and 
Vol.  I.— r. 


powdered  iron.  The  same  firm  also  claim  a 
process  for  chlorinating  tetrachloroethane  in  the 
presence  of  an  artificial  source  of  luht  rich  in 
actinic  rays  (Eng.  Pat.  1106,  1912).  The 
fMonta-chlor  compound  is  formed  at  the  same 
time  and  may  oe  separated  by  allowing  the 
mass  to  crystallise  and  then  pressing  the 
product. 

Hexachlorethane  forms  oolouriess  oiystali 
mellSng  at  187''  to  188'' ;  its  b.p.  is  186'*  so  that 
it  usually  sublimes  without  melting  on  bdng 
heated.  Sp.gr.  s=2'091.  It  has  a  camphor-like 
odour  and  is  used  to  some  extent  in  the  explosives 
industry  as  a  camphor  substitute  in  the  prepara- 
tion of  safety  ei^osives.  Heated  witn  alkali 
to  200**  it  yiAda  oxalic  acid ;  nascent  hydrogen, 
alcoholic  alkali  hydrosulphite,  or  heataig  with 
silver  to  280''  converts  it  into  perchlorethylene. 
Heating  witii  antimonv  pentachloride  to  460" 
converts  it  completely  into  carbon  tetra- 
chloride (Hahn,  Ber.  11,  1735 ;   Schroder,  Ber. 

13,  1070;  Berthelot,  Annalen,  109,  121; 
Geuther,  Annalen,  107,  212;  HI,  174;  Arm- 
strong, J.  pr.  Chem.  [2]  1,  251 ;  Geuther  and 
Brockhoif,  J.  pr.  Chem.  [2]  7, 174  ;  Prudhomme, 
Annalen,  156,  342 ;  Hartmann,  Ber.  24,  1023 ; 
Gossner,  Zeitsoh.  f.  Kryst.  38,  151) 

Heated  in  the  presence  of  water  it  is  con- 
verted gradually  into  perohlor-ethylene. 

A  general  discussion  of  the  above  chlorinated 
derivatives  of  acetylene  and  their  applicatnlity 
in  industry  will  be  found  in  the  rallowmg: 
Chem.  Zeitw  31,  1096;  32,  256;  36,  10^; 
J.  Soa  Chem.  Ind.  36,  94. 

Vintfl  ehhride  (Chlorethylene)  CH,  :  CHCl 
vs  produced  by  the  addition  of  hydrochloric  acid 
to  acetylene  in  the  presence  of  a  suitable  catalyst 
such  as  pumice  sOaked  in  mercuric  chloride. 
Hydrogen  chloride  and  acetylene  in  molecular 
proportions  are  passed  through  tubes  containing 
the  contact  mass  heated  to  180^.  The  ^eld  is 
stated  to  be  quantitative  (Chem.  Fab.  Gnesheim 
Blektron,  D.  R.  P.  278249,  288684,  Eng.  Pat.  • 
21134,  1913).  It  is  a  colourless  gas  which 
condenses  to  a  liquid  in  a  freezing  mixture. 
It  is  sparingly  soluble  in  water,  readily 
so  in  alcohol.  In  sunlight  it  polymerises  to 
a  transparent  white  mass  (Regnault,  Annalen, 

14,  28 ;  Wurtz  and  FrapoUi,  Annalen,  108,  223  ; 
Baumann,  Annalen,  163,  317  ;  Glinsky,  Zeitsch. 
f.  Chemie,  1867,  676  ;  VUlard,  Ann.  Chim.  Phys. 
[71  11,  387 ;  BUtz,  Ber.  35,  3524).  So  far  it 
does  not  appear  to  have  any  special  technical 
application. 

The  digram  on  next  paffe  may  serve  to 
illustrate  t£e  ohici  chemicaT  transformations 
which  acetylene  may  be  made  to  undergo  on  a 
technical  scale. 

AOBTTLBNB  HOHOLOGUSS. 

The  hiff her  members  of  the  acetylene  series  are 
of  relativdy  slight  importance.  They  may  be 
made  by  the  various  general  methods  given  for 
acetylene  itself,  such  as  by  heating  the  mono- 
halogen  derivatives  of  the  ethylene  series  with 
alcoholic  potash,  &c.  They  may  also  be  prepared 
by  treating  sodium  acetyhde  with  alkyl  halides 
in  liquid  ammonia  at  —50''  to  —30°  (Lebeau  and 
Picon,  Compt.  rend.  156,  1077 ;  Picon,  ibid, 
158,  1346).  Another  general  method  is  de- 
scribed by  Schlechter  (D.  R.  P.  263802),  who 
claims  the  production  of  dimethyl  acetylene  and 


00 


ACETYLENE. 


0,HgOH 


OHj  -OOp  CjHj 


OH. OHO 


AI(0£t)« 


OH,  -OOOH 


0H,0H(00jH5)] 


OHjiCHOl 


^ 

y^^ 

Hg 

<H,0) 

:         Hg 

C.H. 

^        ^ 

''  (0,H,OH) 

(OjH^O,)  -^ 

^ 

01, 

OH3  -CO  'OH9 


(0H,0O)|O 


-0H|  'OHCOOO  •OH|)j 


OyHjOlt 


0,H,0l4 


OaO 


OjHOl 


NaOEt 


OfHOliOOfH 


,01  'OOO  'OiH, 


HOI 


0,H0l5 
|oa(OH), 


0H,-(0H)0OOH 


>-0H,01-0OCl 


OHfOl  -OOOH 


C,0l4 

loi, 

0,01, 


ethyl  aoetylene  by  heatinff  calcium  carbide  with 
methyl  or  ethyl  alcohob  respectively,   under 

Sreesure  at  60°  to  260°,  the  prodaota  obtained 
epending  partly  on  the  temperature :« 
CaC,+2CH,0H  =  C5a(OH),+C4H, 

The  following  members  of  the  acetylene  series 
have  been  identified  as  occurrinff  in  coal-gas : 
allylene,  ethyl-acetylene,  propyl-,  isopropyl-, 
butyl-,  isobutyl,  methyl-ethyl,  and  methyl- 
propvl-aoetylenes,  and  orotonylene  (Harzer,  J. 
f.  Oasbeleuchtung,  57,  622). 

The  Chem.  Fabrik.  Florsheim  (Amer.  Chem. 
Abstr.  1912,  1072)  state  that  a  general  method 
for  the  preparation  of  the  dialkyl  acetylenes  is 
to  heat  the  monoalkyl  acetylenes  at  170°  with 
alcoholic  potash,  the  methvl  alkyl  acetylenes 
being  always  formed.  Tne  reverse  action 
takes  place  on  boiling  with  metallic  sodium. 

Methyl-Acetyimie,  or  AUylene,  CH,CiCH, 
is  formed  by  the  action  of  alcoholic  potash  on 
brompropylene : 

CHj-CBr :  CH+KOH=CH,-C.:CH-f-KBr-f  H,0 
also  bv  acting  with  sodium  on  dichloraoetone 
chloride : 
CH,  CCl,CHa,4-4Na  =  CH,C  j  CH-f  4Naa 

or  by  electrotysing  the  alkali  salts  of  citraconic 
or  mesaconio  acids,  or  by  the  action  of  magne- 
sium on  acetone  vapour  and  treating;  the  solid 
mass  thus  obtainea  with  water  (Keiser,  Amer. 
Ohem.  J.  18,  328 ;  Besgrez,  Bull.  Soc.  chim.  r31 
11,  391 ;  Lcwpieau  iM^d  Chavanne,  Compt.  rend. 
140,  1036). 


AUylene  is  a  oolouriess  gaa,  b.p.  —23*6®; 
m.p.  —100°;  very  similar  to  acetylene  and, 
like  it,  forming  compounds  with  metals.  The 
mercuric  compound  (C,H,),Hg  is  obtained 
by  passing  allylene  through  water  containing 
mercuric  oxide  in  suspension.  It  crystidlises 
from  hot  alcohol  in  fine  needles.  It  is  soluble 
in  hydrochloric  acid  with  evolution  of  allylene, 
but  does  not  explode  on  heating  (Keiser,  2.c. ; 
Lossen  and  Domo,  Annalen,  342, 187  ;  Plimpton 
and  Travers,  Chem.  Soc.  Trans,  1894, 264;  Bilts 
and  Mumm,  Ber.  37,  4417 ;  Hofmann,  Ber.  37, 
4469).  The  silver  compound  (C,H,),Ag  forms 
microscopic  needles  which  explode  at  about  160°. 

According  to  Berthelot  (Compt.  rend.  126, 
661,  667,  609,  616)  allylene  when  subjected 
to  the  silent  electric  dischaxf^  condenses  to  a 
solid  with  a  pungent  emj^reumatic  odour; 
with  nitrogen  the  substance  C|sH,oN  is  formed. 

Allylene  forms  with  bromine  additive 
products,  C,H4Br,  and  CsHtBr^  and  with 
halogen  acid  compounds  of  the  type  CH,*CC1  •'CH,. 
Concentrated  sulphuric  acid  absorbs  allylene 
readily,  and  on  distiUins  the  solution  with  water, 
acetone,  mesitylene  and  allylene  sulphonic  acid, 
C,H,SO,H,  are  formed  (Schrohe,  Ber.  8,  18, 
367).  With  hypochlorous  and  hypobromous 
acids,  allylene  forms  dichlor-  ana  dibrom- 
aoetones,  and  trimethyl  allylene  yields  the 
halogen  pinacolins  (Wittorf,  Chem.  Zeit.  23, 606). 

Butlnes.— 1.  Eihyi.  acetvUne  0,Ht-C:CH. 
Formed  by  the  action  of  alcoholic  potash  on 
C,HjCCl,CH,    (Bruylante,    Ber.    8,    412)    by 


ACETYLENE— COMMERCIAL  APPLICATlONa 


61 


paasinfl  acetylene  and  ethylene  through  a  red- 
hot  tnbe  (Berthelot,  Ann.  Chim.  Phys.  [4]  9, 
466)  from  dibrom-bntane  by  the  action  of 
alcoholic  potash  (Dupont,  Compt.  rend.  148, 
1522). 

llie  componnd  is  a  liquid  boiling  at  18®, 
and  forms  precipitates  with  ammonical  copper 
and  silver  solutions ;  f.p.  — 130°. 

With  ammoniacaJ  stiver  chloride  and  alcoholic 
silver  nitrate  it  forms  explosive  compounds 
(Wislioenus  and  Schmidt,  Annalen,  313,  221); 
it  also  yields  a  sodium  derivative  ( Jociez,  Chem. 
Zentr.  1897,  i.  1012). 

2.  CroionyUne  or  dimethyUicetykne 

CHs'CiC'CH,  is  formed  by  acting  with 
alcoholic  potash  on  ^y-dibrombutane 
CH,CHBrCH6rCH, ;  by  the  action  of  sodium 
ethoxide  on         monobrompseudobutylene 

CH.CBr :  CHCCH.  (Holz,  Annalen,  250,  230) ; 
or  by  the  decomposition  of  the  salts  of  fi- 
bromoan^lic  acid  (Wislicenus  and  Schmidt, 
he).  With  bromine  it  forms  a  product  C^H  fii^, 
which  is  solid,  m.p.  243® ;  isocrotonylMie 
dibromide,  h,p.  149®  to  150®,  is  also  known  and 
is  not  readily  attacked  by  zinc  dust  (Wislicenus 
and  Schmidt,  l.e.), 

Crotonylio  mono-  and  hydro- bromides,  as 
well  as  the  iodide  and  chloride  derivatives,  have 
also  been  obtained  (Wislicenus,  Talbot  and 
Henge,  I.e. ;  Peratoner,  Gazz.  chim.  ital.  22, 
ii.  86;  Charon,  Ann.  Chim.  Phys.  1899,  17, 
228 ;  Favorsky,  J.  pr.  Chem.  [2]  42,  143). 

On  shaking  the  nydrocarbon  with  sulphuric 
acid  and  water  (3:1),  hexamethyl  benzene  is 
obtained, 

3C,H.  =  C„H,a  =  C.(CH,), 

The  compound  CHjC'ClCH,  formed  by  the 
action  of  cupric  chloride  on  copper  acetylene,  is 
described  by  Noyes  and  Tucker  (Amer.  Chem. 
J.  19,  123);  pentachlorbntine  C4HCI,  by 
Zincke  and  Kuster  (Ber.  26,  2104).  Derivatives 
of  the  butines,  some  of  which  are  used  as  dye- 
stufiFs,  are  described  by  Fretmd  (Ber.  34,  3109). 

PentineB,  CtHg,  n-Pentine,  prepared  by 
Picon  by  the  action  of  propyl  iodide  on  sodium 
acetylide  in  liquid  ammonia,  is  a  liquid  of 
b.p.  40®,  and  m.p.  —95®  (Picon,  I.e.). 

Isopropyl  acetylene,  prepared  by  the  action 
of  alcoholic  potash  on  the  dibromide  of  isopropyl- 
ethylene  or  methyl-ethyl-ethylene,  b.p.  115® 
(Kalinine,  J.  Buss.  Phys.  Chem.  Soc.  38,  1042). 
In  presence  of  aqueous  solutions  of  cadmium  or 
zinc  chlorides  at  160®  it  is  converted  quantita- 
tively into  methyl  propyl  ketone  (Kutscherow, 
Ber.  42,  2759). 

On  treating  diallyl-tetrabromide  with  potash 
a  liquid  dibnmodiaUyl  is  obtained,  which  boils 
at  210®  and  by  the  action  of  alcoholic  potash 
this  yields  tUpropargyl  CeHe,  a  liquid  boiling 
at  85®  and  isomeric  with  benzene,  but  having 
the  constitution, 

CH:CCHgCH,.C:CH 

I&opropenyl  acetylene  CH,  =  C(CH,-CS:;H 
forms  a  liouid,  b.p.  67-69®,  nD^  1*4332,  and  is 
obtained  oy  dehydration  of  3-methylbutinol 
{v.8.)  by  means  cf  anhydrous  magnesium  sul- 
phate at  230®  C.  (D.R.P.  290558,  Fr.  Bayer  & 
Co.).  It  gives  a  white  precipitate  with  ammo- 
niacal  silver  nitrate  and  a  yellow  precipitate 
with  ammoniacal  cuprous  salts.    It  is  of  some 


'  interest  owing  to  its   close  relationship  with 

iaoprene^ F.  A.  M. 

ACETTLE1IE-€0MMERCIAL  APPLICA- 
I  TIONS.  Although  acetylene  was  discovered  by 
I  Davy  as  far  back  as  1836,  its  use  as  an  illuminant 
became  practicable  onlv  in  1892,  when  Moissan 
in  France,  and  T.  L.  Willson  at  Spray,  showed 
that  it  was  possible  to  make  calcium  carbide  on 
a  commercial  scale  in  the  electric  furnace.  {See 
CiLcauM  Cabbidk.) 

Calcium  carbide,  as  made  in  the  electric 
furnace,  is  a  dark  crystalline  substance  with 
a  metallic  lustre,  having  a  density  of  2 '22.  The 
pure  compound,  however,  has  been  produced  by 
Moissan  m  thin  white  semi-transparent  plates, 
the  colour  of  the  commercial  material  being  due 
to  the  presence  of  iron  and  other  impurities. 

Water  decomposes  the  carbide  with  repro- 
duction of  Ume  and  generation  of  acetylene  : 

CaC,     -f     2H,0    =     Ca(HO),    -f    C,H, 
Calcium  carbide.  Water.         Slaked  lime.     Acetylene 

In  the  early  days  of  carbide  manufacture 
little  attention  was  paid  to  the  purity  of  the 
materials,  with  the  result  that  the  carbide 
formed  contained  impurities,  some  of  which 
wer3  decomposed  by  water  and  gave  products 
contaminating  the  acetvlene.  Since  the  im- 
portance of  purity  in  the  acetylene  has  been 
recognised,  everything  possible  is  now  done  to 
reduce  such  impurities  to  a  minimum. 

The  impurities  found  in  commercial  carbide 
may  be  divided  into  those  which  can  be  decom- 
posed by  water,  and  those  on  which  water  has 
no  action.  Amongst  the  former  are  substances 
evolving  phosphorus  compounds  on  contact  with 
water,  ^uminium  sulphide,  organic  sulphur  com- 
pounds and  metallic  nitrides  :  whilst  the  latter 
class  contains  such  bodies  as  graphite,  carbides 
ot  boron  and  silicon,  carbides  and  dlicides  of 
various  metals  contained  in  the  lime  and  in  the 
ash  of  coke,  these  being  left  with  the  lime  residue 
after  the  decomposition  of  the  carbide  by  water, 
and  in  no  way  influencing  the  purity  of  the  gas. 

The  purity  of  commercial  acetylene  depends 
primarily  on  the  purity  of  the  carbide  from 
which  it  is  generated,  and  as  long  as  it  is  im- 
possible to  get  absolutely  pure  materiab  for  the 
manufacture  of  the  carbide,  so  long  will  im- 
purities be  found  in  the  gas  made  from  it.  The 
most  iinportant  of  these  impurities  are : 

(a)  Fhosphoretted  hydrogen,  obtained  from 
the  decomposition  of  calcium  phosphide,  &c., 
by  water,  and,  in  burning  with  the  acetylene, 
gives  rise  to  phosphorus  pentozide,  which  forms 
a  slight  haze  in  the  room  in  which  the  gas  is 
beinA  burnt. 

(6)  Sulphuretted  hydrogen,  formed  by  the 
action  of  water  on  aluminium  sulphide,  Ac,  and 
yielding  when  burnt  sulphur  dioxide,  which  if 
dissolved  by  condensing  moisture  will  absorb 
oxygen  from  the  atmosphere,  forming  traces  of 
sulphuric  acid. 

(c)  Ammonia,  from  the  magnesium  nitride, 
which  rapidly  corrodes  brass  gas-fittings,  and 
on  burning  produces  traces  of  nitrogen  acids. 

Siliciuretted  hydrogen  is  also  found  in  small 
quantities  in  crude  acetylene. 

Several  processes  have  been  devised  for  the 
purification  of  acetylene  by  the  removal  of  these 
compounds  as  well  as  of  the  hydrocarbon 
vapours  formed  by  the  polymerisation  of  the 


62 


ACETYLENE— COMMERCIAL  APPLICATIONS. 


gas  due  to  high  temperature  during  generation. 
The  only  impurity  that  offers  any  red  difficulty 
in  removal  is  the'  phosphoretted  hydrogen,  and 
three  substanoes  have  oeen  suggested  and  used 
in  practice  for  this  purpose:  (a)  bleachins 
powder,  (b)  acid  copper  or  iron  salts,  ana 
(c)  acid  solution  of  chromic  aoid. 

The  bleaching  powder  is  employed  in  the  form 
of  small  lumps,  as  offering  the  least  resistance 
to  the  flow  of  the  gas  when  in  a  slightly  mois- 
tened state.  Its  action  is  purely  that  of  oxi- 
dation, the  phosphoretted  and  sulphuretted 
hydrogen  beinff  converted  respectively  mto  phos- 
phoric and  sulphuric  acids,  me  acetylene  being 
.unaffected.  To  obtain  as  large  a  surface  as 
possible  the  bleaching  powder  is  sometimes 
mixed  with  an  inert  TOdv,  such  as  sawdust  or 
oxide  of  iron,  but  in  whatever  condition  the 
bleaching  powder  ia  used  the  gas  requires  an 
after-purification  for  the  elimination  of  chlorine 
comiK>unds,  for  which  purpose  a  lime  purifier  is 
generally  employed. 

Bleachins  powder,  though  an  efficient  purify- 
ing agent  when  in  good  onier,  is  apt  to  oe  un- 
certain in  its  action,  and  cases  have  frequently 
occurred  of  spontaneous  firing  and  explosion 
when  air  has  been  admitted  to  purifiers  con- 
taining this  material  that  have  been  in  use  for 
some  time,  so  that  precautions  are  neoessary 
when  usine  this  method  of  purification. 

An  acid  solution  of  cuprous  chloride,  or  solids 
made  by  impregnating  kieselgfihr  or  similar 
porous  bodies  with  the  acid  copper  salt,  are 
also  very  effective  in  removing  the  various 
impurities,  the  phosphorus  and  sulphur  com- 
pounds being  transformed  into  copper  phosphide 
and  sulphide.  The  disadvantages  of  the  process 
are  that  a  second  purification  with  ume  is 
required  to  remove  acid  vapours,  and  that  the 
material  being  highly  acid  cannot  be  used  in 
ordinary  metu  containers,  whilst  if  the  copper 
salt  became  neutralised  by  ammonia  there  might 
be  danger  of  the  explosive  copper  acetyhde 
being  formed.  Under  suitable  conditions  1  kilo- 
gram of  the  material  will  purify  20  to  25  cubic 
metres  of  the  gas,  the  acetylene  not  being  acted 
upon,  and  the  action  being  regular  and  certain. 

Chromic  acid  in  solution  containing  sulphuric 
or  acetic  acid,  or  kieselgfihr  charged  with  this 
mixture,  is  the  third  purifying  agent,  and 
eliminates  the  phosphoretted  ana  sulphuretted 
hydrogen  and  the  ammonia.  When  exhausted 
the  spent  material  can  be  regenerated  by 
exposure  to  the  air. 

In  practice  these  three  materials  seem  to  give 
equally  good  results,  and  the  passage  of  the  gas 
throu^  the  solution  or  solid  scrubs  out  of  it 
to  a  great  extent  the  tarry  fog  and  lime  dust 
often  mechanically  held  in  the  gas  when  it  has 
l^n  generated  too  rapidly  or  at  too  high  a 
temperature. 

Absolute  purification  is  by  no  means  neces- 
sary ;  for  ordmary  use  all  that  is  required  being 
to  reduce  the  amount  of  impurity  below  the  limit 
at  which  the  products  of  combuBtion  are  injurious 
to  health  or  cause  haze ;  and  with  a  fairly  pure 
specimen  of  carbide  mechanic€j  scrubbing  is 
sufficient  if  a  generator  of  the  non-automatic 
type  is  employed,  and  the  gas  is  stored  in  a 
holder  before  use. 

Although  the  generation  of  acetylene  by 
bringing  calcium  carbide  in  contact  with  water 


seems  so  simple,  yet  in  actual  practice  it  was 
complicated  by  several  difficulties,  amodgBt 
which  may  be  mentioned  the  heat  of  uie 
reaction,  which  caused  the  polymerisation  of 
some  of  the  acetylene,  and  by  the  fact  that  the 
evolution  of  gas  did  not  cease  immediately 
the  water  supply  was  cut  off,  this  being  due  to 
water  mechamcaUy  held  in  the  residue  formed, 
to  the  dehydration  of  the  caloium  hydroxide 
by  the  unchanged  carbide,  as  well  as  to  the 
moisture  condensed  from  the  gas  as  the  tem- 
perature of  the  generator  fell. 

Acetylene  generatore, — ^These  can  be  divided 
into  two  main  classes — those  in  which  water  is 
brought  in  contact  with  the  carbide,  the  latter 
being  in  excess ;  and  those  in  which  the  carbide 
is  tluown  into  water,  the  water  beinx  always  in 
excess.  The  first  class  m»v  be  subcuvided  into 
those  in  which  water  is  aflowed  to  rise  to  the 
carbide,  those  in  which  it  drips  on  to  the  carbide, 
and  those  in  which  a  vessd  full  of  carbide  is 
lowered  into  water  and  then  withdrawn  as  the 
genl^tion  of  the  gas  becomes  excessive. 

Each  of  these  l^pes  may  be  '  automatic  *  or 
'non-automatic'  In  the  former  are  to  be 
found  devices  for  imilating  and  stopping  at  will 
the  generation  of  the  gas  within  kmits,  whilst 
the  non-automatic  '  variety  aim  at  developing 
the  MS  from  the  carbide  witii  as  little  loss  as 
posnole  and  storing  it  in  a  holder. 

The  points  to  he  aimed  at  in  a  good  genera- 
tor are  : 

(a)  Low  temperature  of  generation. 

(h)  Complete  decomposition  of  the  carbide. 

U)  Maximum  evolution  of  gas  from  carbide 
usea. 

(d)  Low  pressure  in  eveiy  part  of  the  ap- 
paratus. 

(e)  Removal  of  all  air  from  the  apparatus 
before  collection  of  the  gas. 

Generators  of  the  ^drip'  type,  in  which 
water  is  allowed  to  fall  slowly  upon  a  mass  of 
carbide,  possess  most  of  the  disadvantages  due 
to  heat  of  generation,  fluctuation  of  pressure, 
&c.,  and  this  type  has  been  abandoned  except 
for  the  smallest  forms  of  portable  generator. 
Those  in  which  water  rises  to  the  carbide  are 
most  efficient,  and  overheating  can  be  avoided 
by  ensuring  that  the  water  never  rises  above 
that  portion  of  the  carbide  which  is  undergoing 
decomposition :  in  other  words,  that  tiie  gas 
leaves  the  carbide  immediately  upon  its  forma- 
tion and  passes  away  to  the  hmder  with  the 
least  opportunity  for  becoming  overheated  by 
contact  with  decomposing  carbide. 

Generators  in  which  the  carbide  dips  into 
water  and  is  then  withdrawn  are  apt  to  overheat 
to  a  dangerous  extent,  especially  if  the  generator 
be  over-driven. 

Although  it  might  be  expected  that  the 
dropping  of  the  carbide  into  an  excess  of 
water  would  produce  the  coolest  and  purest  gas, 
yet  evidence  of  overheating  of  the  gas  is  onen 
found  in  generators  of  this  class,  as  a  coating 
of  lime  can  form  around  the  lumps,  preventing 
the  free  access  of  water,  and  allowing  the 
interior  of  the  mass  from  which  generation  is 
proceeding  to  become  heated  to  redness;  the 
efficiency  also  is  lowered  as  a  certain  amount 
of  the  gas  is  dissolved  in  its  upward  passage 
through  the  large  volume  of  water. 

Theoretically  64  parts  by  weight  of  carbide 


AOBTTLBNl^-COMMBRCIAL  APPLICATION& 


63 


reqaire  only  36  parts  by  weight  of  water  for 
complete  decomposition  and  conyenion  of  the 
lime  into  hydroxide,  but  it  is  found  in  practice 
tii&t,  owins  to  the  heat  of  the  reaction  driving 
off  some  o!  the  water  as  steam,  and  a  further 
portion  mechanically  adhering  to  the  slaked 
ume,  double  this  amount  of  water  is  necessary, 
and  the  only  safe  way  to  ensure  entire  decom- 
position of  the  carbide  is  to  add  sufSoient  water 
to  flood  the  residue. 

Carbide  is  also  supplied  in  the  form  of 
'briquettes,*  coated  with  material  to  prevent 
deterioration  in  air;  at  the  same  time  the  after- 
generation  of  ffas  niien  the  water  supply  is 
stopped  is  larsdy  prevented.  These  briquettes 
ace  particular^  smted  for  motor  car  headlight 
outfits  and  taue  lamps. 

Combustion  of  acetylene, — ^When  acetylene  is 
burnt  in  air  under  such  conditions  as  to  complete 
its  combustion,  it  is  converted  into  carbon 
dioxide  and  water  vapour,  the  same  compounds 
that  are  produced  by  all  combustible  nydro- 
carbons,  1  cubic  foot  of  the  gas  requiring  2( 
cubic  feet  of  oxygen,  or  five  times  that  amount 
of  air. 

When  acetylene  was  first  used  for  illumina- 
tion, burners  of  the  Union  jet  type  (similar  to 
coal-gas  burners)  were  employed,  some  of  these 
being  of  specially  small  size.  In  such  burners 
the  orifices  for  the  issue  of  the  gas  were  very 
small,  and  were  drilled  at  a  more  obtuse  axiafe 
than  for  coal  gas.  Burners  of  this  type,  whust 
giving  good  results  for  a  time,  soon  developed 
a  smoky  flame,  a  filiform  growth  of  carbon 
appearing  on  the  jet,  so  that  they  were  generally 
unsuitable. 

Smoking  is  very  likely  to  develop  with 
acetylene,  especially  when  the  eas  is  turned 
down.  This  u  due  principally  to  tne  polymerisa- 
tion of  the  ^as  by  heat,  producing  liquid  hydro- 
carbons (prmcipally  benzene)  and  solid  carbon 
by  decomposition,  when  the  gas  issuing  from  the 
small  orifices  becomes  unduly  heateid.  With 
a  high  efflux  velocity  sufficient  air  will  be  drawn 
in  to  ensure  primary  combustion  close  to  the 
orifice  and  the  trouble  is  largely  overcome,  but 
the  reduction  of  the  gaa  pressure  prevents  this 
action.  An  accumulation  of  particles  of  carbon, 
or  other  foreign  matter,  sucn  as  lime  particles 
from  theffenerator,  will  act  similarly  by  impeding 
the  gas  now,  so  that  once  carbon  begins  to  form 
the  actions  leading  to  smoking  rapidly  accelerate. 

On  breaking  open  a  steatite  jet  of  a  burner 
in  which  smoking  nas  developed  carbon  deposit 
will  be  found  to  have  extenc&d  to  some  depth, 
showing  that  a  liquid  hydrocarbon  has  soaked 
into  i&  steatite  and  been  there  further  de- 
ooinpoeed  by  heat. 

The  actions  leading  to  the  formation  of  the 
li(|uid  product  in  general  arise  at  the  jet,  but 
with  a  bad  type  of  generator,  where  over- 
heating takes  place,  polymerised  products  may 
be  carried  forward  in  the  sas,  ana  deposited  in 
and  around  the  narrow  orifice  in  the  steatite  or 
other  poroue  material. 

Attempts  to  overcome  these  difficulties  were 
on  the  lines  of  introducing  air,  eithei^  admixed 
with  gas,  which  was  soon  abandoned  on  account 
of  danger,  or  constructing  the  burner  so  that 
air  was  drawn  in  through  adjacent  orifices  by 
the  injector  action  of  the  issuing  gas,  a  method 
adopted  by  Bullier  (1896-97). 


Bullier*s  principle  of  making  the  tips  of  the 
burner  jets  into  small  bunsens  was  adopted  by 
Dolan  in  America,  and  Billwiller  on  the  Continent. 

The  Billwiller  burner  has  two  steatite  arms 
rising  at  right  angles  from  a  common  base 
from  which  the  acetylene  issued  at  two  small 
orifices  exactly  opposite  each  other  and  giving 
the  double  jet.  Immediately  above  the  gas 
orifice  a  small  platinum  plate  was 
fixed  at  a  distance  of  about  0'6 
mm.  from  the  steatite,  with  a 
hole  in  it  rather  laiger  than  the 
orifice  in  the  steatite  just  below. 
The  acetylene  issuing  irom  the 
hole  in  the  steatite  rushed  through 
the  hole  in  the  platinum  above  ^  . 
and  drew  air  in  under  the  plati-  '^^^'  ^' 
num  plate.  The  air  so  drawn  in  flowed  to  the 
confines  of  the  rapidly  travelling  stream  of 
acetylene  and  passed  upwards  around  it,  so 
preventing  contact  between  the  edge  of  the 
hole  in  t^  platinum  and  the  acetylene,  whilst 
the  metal,  being  part  of  a  coUar  of  platinum 
fixed  round  each  steatite  arm,  and  being  a 
good  conductor  of  heat,  prevented  such  heating 
as  would  lead  to  the  deposition  of  carbon  from 
the  sas.  ^ 

Jn  1897  Dolan  in  America  made  a  burner 
on  the  same  principle  as  the  Billwiller  burner, 
thoujB^h  of  sbghtly  different  construction.  It 
consisted  of  a  metal  base,  the  upright  from 
which  forked  into  two  arms,  which  near  their 
extremities  were  bent  inwards  at  right  angles. 
These  arms  carried  steatite  or  'lava'  tips, 
bored  with  a  fine  hole  from  the  interior  to  uie 
base  of  the  mushroom  head,  where  its  diameter 
was  more  than  doubled,  whilst  four  small  lateral 
air  tubes  were  bored  at  regular  intervals  from 
the  base  of  the  head  to  the  broad  aperture  of 
the  nipple,  with  the  result  that  the  flow  of 
acetylene  from  the  narrow  into  the  wider  tube 
sucked  air  in  throush  the  side  tubes  and  sur- 
rounded the  ascending  gas  with  an  envelope 
which  prevented  its  contact  with  the  heated 
tip.  These  burners,  which  are  more  generally 
known  as  the  '  Naphey '  burners,  save  very 
good  results,  and  have  been  more  widely  adopted 
than  the  Billwiller  bumen  that  preceded  them, 
partly  because  they  did  away  with  the  expense 
of  the  platinum,  were  cheaper  to  make,  and 
were  less  liable  to  break. 

The  sreat  drawback  to  all  the  Naphey  tip 
burners  is  that  the  heat  from  the  flame  causes 
a  slight  and  gradual  warping  of  the  metal 
mounting,  with  the  result  that  after  a  time  the 
jets  become  slightly  thrown  out  of  their  true 
position,  which  at  once  distorts  the  flame  and 
causes  it  to  throw  up  smoky  points.  This 
trouble  is  not  found  with  burners  having  steatite 
or  composition  arms,  as  these,  being  pressed  or 
cut,  do  not  warp  with  the  heat. 

These  burners  proved  the  forerunner  of  a  host 
of  others  in  all  of  which  the  same  principle  was 
adopted,  one  of  the  simplest  and  most  popular 
bein£  shown  in  Fig.  2,  uniilst  Fif.  3  is  a  section 
of  tne  same  burner,  showing  the  construction 
and  air  inlets. 

Although  these  burners  possess  many  advan- 
tages and  can  be  used  for  several  hundred  houn 
without  smoking,  they  have  the  drawback  that 
the  flame  cannot  be  turned  down,  as,  after 
the  flame  has  been  left  turned  down  for  an 


64 


ACETYLENE— COMMERCIAL  APPLICATIONS. 


hour  or  two,  it  will  be  found  that  it  will 
generally  start  smoking  when  the  normal  con- 
sumption is  restored. 

In  order  to  overcome  this  trouble  Bray  intro- 
duced a  burner  in  which,  by  placing  a  second 


Fia.  2. 


Fio.  3. 


air-supply  chamber  of  larger  dimensions  above 
the  first,  such  a  complete  encircling  of  the  jet 
of  gas  by  air  was  ensured  that  the  variations 
in  gas  pressure  caused  by  turning  down  the 
flame  do  not  lead  to  carbonisation. 

Another  burner  has  been  brought  out  in 
which  the  idea  of  air  injection  has  been  success- 
fully adapted  to  a  slit  burner :  the  gas  issues 
from  a  series  of  fine  holes  placed  below  a  cap 
provided  with  a  broad  slit  and  side  air  tubulure, 
the  gas  drawing  in  sufficient  air  in  its 
passage  throusn  the  slit  to  prevent 
smoking  or  caroonisation  of  the  burner 
(Fig.  4).  Such  slit  type  burners  are 
particularly  suited  for  use  in  motor-car 
headlights,  &c.  With  twin  jet  burners 
an  obstruction  in  one  orifice  may  cause 
pi^  .  a  somewhat  long  flame  to  issue  from 
rio.  4.  |.jj^  other  orifice,  which  mav  impinge 
on  lenfies  or  mirrors  situated  close  to  the  burner. 
The  slit  type  is  free  from  this  disadvantage. 

From  toe  earliest  introduction  of  acetylene 
attempts  have  been  made  to  utili-^e  it  with 
incandescent  mantles,  but  under  the  pressures 
which  are  usually  obtained  from  the  ordinary 
generating  apparatus  this  has  not  proved  success- 
ful. Acetylene,  when  consumed  in  an  atmo- 
spheric burner,  gives  an  excessively  hot  flame, 
not  only  on  account  of  its  composition,  but  also 
from  its  endothermio  character.  Several  diffi- 
culties, however,  are  met  with  in  trying  to  bum 
acetylene  mixed  with  air  in  sufficient  proportion 
to  yield  a  non-luminous  flame,  namely  : 

[a)  The  wide  range  over  which  such  mixtures 
are  explosive. 

(6)  The  low  temperature  of  ignition. 

(c)  The  high  speed  at  which  the  explosive 
wave  travels  tnrough  the  mixture  of  gas  and  air. 

In  Older  to  make  a  bunsea  burner  for  acetylene 
the  tube  has  to  be  verv  narrow,  and  even  then 
flashing  back  is  very  liable  to  occur,  whilst  a 
high  pressure  is  needed  to  bring  about  a  satis- 
factory mixture  of  the  gas  with  sufficient  air  to 
ensure  combustion  with  an  absolutely  non- 
luminous  flame.  The  range  of  explosibility  lies 
between  3  p.c.  and  82  p.c.  of  acetylene  in  the 
mixture,  and  the  propagation  of  the  explosive 
wave  cannot  be  stopped  by  the  ordinary  device 
of  using  wire  gauze,  on  account  of  the  low 
ignition  point  of  the  mixtures.  By  using  a  tube 
^  mm.  in  diameter  the  explosion  ceases  to  be 
propagated  at  all,  but  such  tubes,  on  account  of 
their  small  diameter,  cannot  be  utilised  singly. 
The  difficulty  can  be  surmounted  by  using  a 
bundle  of  small  tubes  united  to  form  a  single 
burner,  or  by  employing  a  large  tube  having  a 
constriction  at  one  point  of  not  more  than  5  mm. 
diameter.    The  diameter  of  the  tube  at  the 


oonstriction  must  be  in  a  definite  proportion  to 
the  particular  mixture  of  air  and  acetylene  con- 
sumed, as  the  more  air  the  greater  must  be  the 
constriction  in  the  strangulated  portion  of  the 
tube,  owing  to  the  increased  velocity  of  the  ex- 
plosive wave. 

With  an  acetylene  bunsen,  and  using  a 
Welsbach  No  2  mantle,  as  much  as  90  candles 
per  cubic  foot  of  acetylene  has  been  obtained. 
It  may  be  taken  that  when  UBed  with  a  mantle 
acetylene  will  give  double  the  illuminating  power 
per  cubic  foot  as  compared  with  the  light 
obtained  when  the  gas  is  burnt  in  the  ordinary 
acetylene  flat-flame  burners  under  the  best 
concutions,  but  very  widely  different  results 
have  been  obtained,  owing  to  irTe^[ularitie6  in 
the  pressure  or  lack  of  air  r^xdation,  and  at 
the  moment  of  lighting  or  turning  out  there  is 
a  liability  of  a  small  but  violent  explosion, 
which  has  disastrous  effects  upon  the  mantle. 
A  further  difficulty  is  caused  when  phosphoretted 
hydrogen  is  present  as  an  impurity,  for  this 
leads  to  the  lormation  of  fusible  phosphates  of 
thorium  and  cerium,  with  consequent  destruc- 
tion of  the  mantle.  Apart  from  these  con- 
siderations, the  mantle  appears  to  be  hardened 
and  strengthened  by  the  intense  heat  to  which 
it  is  subjected,  but  it  is  not  yet  determined 
how  the  life  of  the  mantle  is  affected  by  the 
temperature  of  the  flame. 

Under  the  light  yielded  by  the  combustion  of 
acetylene  colours  appear  practically  the  same 
as  in  dayliffht,  and  ul  tints  and  shades  can  be 
as  clearly  distinguished  from  one  another  as  in 
sunlight.  For  this  reason  the  ^as  has  been 
found  to  be  of  invaluable  utility  m  dyeing  and 
colour  printing.  The  spectrum  of  acetylene, 
however,  although  the  same  as  that  of  daylight 
for  red  and  yellow,  has  an  increase  in  the  uue 
rays  of  0*46,  which  brings  them  to  about  the 
same  value  as  the  Northern  Light.  The  violet 
rays  show  a  slight  increase,  so  that  acetylene 
is  even  richer  than  sunlight  in  the  rays  which 
are  so  essential  to  the  chemical  action  of  light, 
and  yet  the  red  rays  which  are  so  detrimental 
in  colour  work  do  not  predominate,  as  in  the 
electric  are. 

Acetylene  has  been  found  of  great  service  in 
the  illumination  of  small  towns  and  country 
villages,  and  for  isolated  houses  and  farms.  It 
has  been  employed  in  photography  on  account 
of  its  richness  in  actinic  rays.  For  headlights 
on  motors,  for  train  lighting,  for  buoys,  and 
in  fact  in  a  number  of  cases  where  bright  and 
trustworthy  light  is  required  without  the  com- 
plication of  a  coal-gas  works  or  the  dangers  of 
oil,  acetylene  has  proved  its  worth. 

It  has  been  found  that  the  rays  from  an 
acetylene  light  possess  remarkable  penetrative 
powers  in  fog  or  mist,  being  in  tnis  respect 
superior  to  the  arc  light  or  incandescent  mantle. 

Storage  of  dissolved  Acetylene. — In  the  early 
days  of  the  development  of  acetylene  for  com- 
mercial purposes  attempts  were  made  to  employ 
it  in  a  Uquefied  form  or  compressed,  but  under 
pressure  tne  gas  proved  too  dangerous.  Even 
at  2  atmospheres  pressure  acetylene  free  from 
oxygen  can  be  exploded.  It  was  enacted  in 
1807  that  the  gas  snould  never  be  subjected  to 
a  pressure  exceeding  100  inches  of  water  (about 
4  lbs.  per  square  inch) ;  later  this  was 
to  250  mches. 


ACETYLENE— COMMERCIAL  APPLICATIONS. 


55 


In  1896  Claade  and  Hess,  in  France,  sug- 
gested the  idea  of  makinff  use  of  the  solubility 
of  acetylene  in  certain  liquids  as  a  means  of 
storing  this  gas,  and  acetone  was  tried  as  the 
solvent.  Acetone  dissolves  24  times  its  volume 
of  acetylene  at  15^  and  under  ordinary  atmo- 
spheric pressure,  the  solubilitv  increasmg  pro- 
portionately with  pressure.  The  volume  uf  the 
acetone  also  increases  very  largely.  It  was 
found  that  the  simple  solution  of  acetylene  in 
acetone,  although  leas  liable  than  the  com- 
pressed or  liquefied  acetylene  to  explosion, 
could  not  be  said  to  be  sufficiently  free  from 
danger  to  admit  of  its  general  use.  Janet  and 
Fouche  discovered  that  when  acetylene  is 
dissolved  in  acetone  absorbed  by  porous  material 
of  the  ri^ht  kind  under  10  atmospheres  pressure, 
it  was  impossible  to  produce  explosion.  The 
practice  in  this  country  for  the  storage  of 
acetylene  is  to  fill  a  cylinder  with  porous  material 
(porosity  about  80  p.c.),  then  to  add  a  volume 
of  acetone  equal  to  40  p.c.  of  the  original 
cylinder  volume,  and  pump  in  the  gas  to  a 
pressure  of  150  lbs.  per  square  inch.  In  1901 
this  was  fixed  as  the  legal  pressure  limit.  Thus 
a  cylinder  of  1  cubic  foot  capacity  containing  0*4 
cubic  foot  of  acetone  will  hold  lOQ  cubic  feet  of 
the  gas,  most  of  which  will  be  given  off  when 
the  valve  is  opened. 

There  are  practically  only  three  porous  ma- 
terials in  use  tor  absorotion  of  dissolved  acety- 
lene in  the  United  iCinxdom :  (a)  a  porous 
agglomerate  of  asbestos,  kieselguhr,  and  char- 
coal, and  a  suitable  cement ;  (6)  charcoal  filling ; 
(r)  kapok  filling.  The  porosity  should  not  exoeeid 
80  p.c.  The  solvent  must  not  completely  fill  the 
porous  material  under  any  rise  of  temperature 
ukely  to  be  experienced.  With  the  present  type 
of  cylinder,  the  pressure  at  present  allowed,  i.e. 
150  lbs.  per  sq.  in.,  should  not  be  increased  ;  for 
solid  drawn  cylinders  and  for  those  of  100  cubic 
feet  capacity  and  over  in  which  the  acetylene- 
welding  at  the  top  and  bottom  is  strengthened, 
the  pressure  allowed  might  safelv  be  increased 
to  225  lbs.  per  square  inch  provided  a  solvent 
is  used  in  addition  to  the  porous  material. 
The  best  material  for  the  construction  of 
cylinders  Lb  a  mild  steel  of  high  ductility,  of 
which  the  carbon  content  does  not  exceed 
0*25  p.c.  and  the  phosphorus  and  sulphur  each 
do  not  exceed  0*05  p.c.  The  test  pressure 
should  be  four  times  the  working  pressure  and 
should  be  maintained  for  not  less  than  fifteen 
minutes  (Home  Office  Report,  J.  Soc.  Chem. 
Ind«  1918, 116^). 

Acetylene  Welding  and  Metal  Cutting. — Acety- 
lene is  largely  employed  for  autogenous  welding 
and  for  metei  cutting ;  in  the  latter  case  extra 
oxygen  being  supplied  so  that  the  metal  itself 
is  burnt  away.  The  temperature  of  the  oxy- 
aoetylene  flame  is  approximately  3000°,  and 
from  the  nature  of  tne  combustion  the  flame 
has  a  reducing  action  tending  to  exclude  the 
possibility  of  oxidation  of  the  metals  undei^oing 
treatment.  Theoretically  2*5  volumes  of  oxygen 
are  required  for  each  volume  of  acetylene,  but 
in  practice  it  is  found  that  the  proportions  are 
approximately  1-4  to  1 0,  this  low  proportion  of 
oxygen  ensurmg  a  reducing  action  m  tne  flame. 

There  are  two  systems  of  operating :  in  the 
high-pressure  system  the  oxysen  Ib  delivered 
from  an  ordinary  cylinder  unc&r  pressure,  and 


the  acetylene,  dissolved  in  acetone  under 
pressure,  is  also  supplied  from  cylinders.  Both 
cylinders  are  fitted  with  special  governors,  as  a 
perfect  regulation  of  the  flame  iB  one  of  the 
main  conditions  of  success.  This  system  has  the 
great  advantage  of  a  portable  outfit,  and  can 
be  applied  in  confined  spaces,  but  it  is  more 
expensive  than  the  alternative  system. 

With  the  low-pressure  plant  the  acetylene  is 
made  in  an  ordinary  generator,  which  may  be 
of  the  automatic  or  non-automatic  type,  the 
size  of  the  works  to  a  great  extent  influencing 
the  kind  of  generator  used,  but,  whatever  type 
be  adopted,  it  is  necessary  that  the  generation 
of  the  gas  should  not  be  accompanied  by  over- 
heating, as  this  leads  to  low  temperatures  at  the 
burner  and  other  troubles.  The  gas  should  be 
purified  before  use,  as  the  presence  of  the 
phosphoretted  and  sulphurett^hydrogren  would 
tend  to  spoil  the  welcC  ft&d  the  purifymg  agent 
should  bis  renewed  when  necessary.  After 
leaving  the  purifiers  the  gas  is  distributed  to  the 
various  points  in  the  workshops  in  gas-  or 
steam-barrel  piping,  and  at  eacn  point  a  hy- 
draulic back-pressure  valve  is  inserted,  in  order 
to  prevent  the  oxygen  through  any  mischance 
flowing  back  through  the  acetylene  service.  The 
use  of  an  efficient  water- trap  is  a  sufficient  safe- 
guard in  practice. 

The  first  successful  blowpipe  was  the  Fouche, 
employed  with  the  low-pressure  system,  and 
this  type  has  held  its  own  in  spite  of  the  com- 

Eetition  of  other  patterns.  After  the  weld  has 
een  made  the  plate  \a  annealed,  this  being 
essential.  Although  the  results  of  tests  up  to 
the  present  are  not  very  consistent,  it  may  be 
taken  that,  on  the  average,  the  welded  joint 
has  a  tensile  strength  from  95  to  80  p.c., 
depending  on  the  thickness  of  the  plate. 

There  are  many  classes  of  work  in  which 
oxy-acetylene  welcung  can  be  advantageously 
employed.  In  the  motor-car  industry,  both 
in  the  garage  and  repair  shop,  it  has  proved  of 
great  service,  it  being  a  comparatively  simple 
matter,  for  instance,  to  mend  a  cracked  cylinder 
or  gear-box.  For  the  welding  of  tubes,  repairs 
to  boilers  in  situ  needed  by  corrosion,  &o., 
for  the  mending  of  fractured  stems  and  stem 
posts,  the  process  has  been  invaluable. 

Iron  and  steel  (including  thick  armour  plate) 
are  now  commonly  cut  with  oxy-acetylene  olow- 
pipes  with  great  saving  in  time  and  cost.  The 
method  is  not  so  suitable  for  cast-iron.  The 
blowpipes  are  made  with  a  central  oxygen  supply 
jet,  tne  acetylene  serving  to  heat  the  metal  to 
its  ignition  point,  when  the  excess  oxygen  bums 
it  to  oxide,  which  flows  away  in  a  molten 
condition.  The  ratio  of  acetylene  to  oxygen 
employed  varies  from  25  p.c.  for  thin  plate  to 
10  p.c.  for  the  thickest.  Tne  following  rates  of 
cut  and  oxygen  consumption  are  attained  : — 


Thickness 

Foot 

run  of  cut 

Oxygen  consumed 

of  plate. 

per  hour. 

per  ft.  run. 

I 

40 

2-2 

3 

20 

9-0 

6 

18 

280 

9 

16 

600 

12 

16 

100-0 

• 

56 


ACETYLENE— COMMERCIAL  APPLICATIONS. 


Acetylene  tor  Poner  Purpoeee, — Owing  to  the 
violence  of  the  explosion  when  mixed  with  air 
acetylene  is  liable  to  give  unduly  hi^h  preBsuies 
in  the  cylinden  of  internal  combustion  engines. 
Mozeover,  it  is  too  expensive  to  compete  with 
other  fuels.  Tests  on  engines  of  a  few  horse- 
power have  shown  consumptions  of  about 
6*3  cubic  feet  per  B.H.P.  hour.  It  has,  however, 
been  successfully  employed,  particularly  in  the 
United  States,  for  stsxting  up  motor  car  engines, 
tiie  advantage  of  the  gss  tor  this  purpose  is 
obvious  where  it  is  carried  in  the  compressed 
form  (in  acetone)  for  the  usual  lighting  sets. 
The  violence  of  the  explosion  has  to  be  guarded 
against,  otherwise  damage  to  the  engine  may 
result.  J.  8.  S.  B. 

ACBTTLBALIGTLIC  ACID  v.  Saliotuo  Aoid. 

ACHROPEXTRDI  v.  Dkxtbik. 

ACHTBANTHES  ASPERA  or  Aghara,  An 
Indian  plant  used  as  a  simple  and  as  a  remedy 
for  toothache. 

ACID  ALBUMEN  v.  Pbotxins. 

ACID  ALIZARIN,  -BLUE,  -GREEN  v.  Au- 

ZABUr  AXD  ALLIED  OOLOUBINO  XATTBBS. 

ACID     CERISE      V. 


COLOUBIIVO  11A.TTXBS. 

ACID 


COLOUBINO  HATTMB8. 

ACIDIMETRY  and  ALKAUMETRY.  This 
branch  of  quantitative  analysis  dealing  with  the 
estimation  of  acids  and  alkalis  is  of  great 
technical  importitnce.  In  pure  aqueous  solu- 
tions the  amount  of  acid  or  alkali  can  usually 
be  ascertained  with  considerable  accuracy  by 
determining  the  specific  gravity  of  the  liquid 
at  a  definite  temperature  and  referring  to  a  table 
especially  drawn  up  for  this  purpose. 

Direct  estimations  may  also  be  made  by 
suitable  gravimetric  methods,  but  volumetric 
processes  are  almost  exclusive^  employed,  and 
are  indeed  the  only  methods  available  for 
distinguishing  between  free  and  combined  acid 
or  alludL  In  these  operations  the  quantity  of 
acid  or  alkali  present  is  calculated  from  the 
amount  of  standard  alkali  or  acid  required 
respectively  to  neutralise  it  exactly,  the  precise 
point  of  neutralisation  being  determined  by 
the  addition  of  a  small  quantity  of  an  indicalar, 
i.e.  a  substance  which  by  undergoing  a  marked 
change  of  colour  renders  evident  the  transition 
from  acidity  to  alkalinity,  or  vice  versd. 

Indieaton.  Although  many  natural  and 
artificial  colouring  matters  have  been  recom- 
mended as  indicators,  comparatively  few  are 
actually  used,  those  most  frequently  emidoyed 
being  methifl  oranpe,  phenolphihai^n,  and  litmus. 

Artificial  indicators  are  either  very  weak 
organic  acids  or  (more  rarely)  weak  bases,  and 
the  prevalent  view  regarding  their  behaviour  is 
that  in  solution  their  colour  in  the  non-ionised 
state  differs  from  that  which  they  exhibit  in 
the  ionic  condition. 

In  accordance  with  the  ionic  theory  of  solu- 
tion, a  very  weak  acid  HM  exists  in  solution, 
mainly,  but  not  entirely,  in  the  non-ionised  state, 
the  equilibrium  between  ions  and  undissociated 

+     - 
molecules  HM^H+M  being  expressed  quanti- 
tatively by  the  equation 
-     + 
MxH/HM  -» constant 

in  which  the  symbols  denote  the  molecular  con- 


centrations of  the  ions  and  molecules,  and  where 

+ 
as  in  the  case  under  discussion  M  and  H  are  very 
small  in  comparison  with  HM. 

Any  increase  in  the  value  of  H,  which  is 
effected  by  adding  a  small  quantity  of  a  fairly 
strong  (ionised)  acid  to  the  solution,  leads 'to  a 

corresponding  diminution  in  the  value  of  M. 
The  reverse  change,  leading  to  an  increase  in 

the  value  of  M,  with  a  corresponding  decrease 

+ 
in  the  value  of  H,  is  effected  by  adding  a  sliffht 
amount  of  a  fairly  strong  (ionised)  alkali  ny- 

droxide,  since  the  equilibrium  H  x  OHaconstant 
obtains  in  aqueous  solutions,  and  the  alkali  added 
increases  considerably  the  value  of  the  factor 

OH.  If  the  acid  HM  and  the  ion  M  differ  in 
colour,  then,  in  any  solution  containing  this 
acid  a  change  from  acidity  to  alkalinity,  t.e.  from 

+ 
a  state  in  whicU  H  predominates  over  OH  to  the 

reverse  condition,  aiayl^  indicated  by  an  appve- 
oiable  change  of  colour.  The  degree  of  ionic 
dissociation  of  the  indicator  HM  must,  howew, 
be  considerably  smaller  than  that  of  either  add 
or  alkali  emploved  in  the  titration ;  moreover, 
another  acid  UB,  having  a  smaller  degree  of 
ionisation  than  HM,  will  indicate  the  transition 
with  even  greater  precision,  providing  that  the 
recognition  of  the  colour-change  is  not  more 
difficult.  The  quantity  of  indicator  emploved 
must  be  so  small  that  the  amount  of  alkali 
required  to  neutralise  it  is  negligible. 

For  Theory  of  Indicators,  v.  Ostwald  (Scien- 
tific Foundations  of  Analytical  Chemistry,  trans- 
lated by  MoGowan),  Kuster  (Zeitsch.  anorg. 
Chem.  1897,  13,  127),  Waddell  (J.  Phys.  Chem. 
1898,  2,  171),  Vaillant  (Compt  rend.  1903,  136. 
1192),  Stieglitz  (J.  Amer.  Chem.  Soc  1903,  25, 
1112;  Amer.  C3iem.  J.  1908,  39,  651 ;  1909,  42, 
115),  McKoy  (Amer.  (^em.  J.  1904,  31,  503), 
Hewitt  (Analyst,  1908,  33,  85),  Salm  (Zeitsoh. 
l^ysioaL  Chem.  1906,  57,  471 ;  Zeitsoh.'  Elek. 
C^em.  1907,  13,  125),  Salessky  (Zeitsch.  Elek. 
Chem.  1904, 10,  204),  Fels  (Zeitsoh.  Elek.  Chem. 
1904,  10,  208),  Schoorl  (Chem.  Zentr.  1907,  i. 
300,  502,  585),  Hantzsoh  (Ber.  1907,  40,  1556 ; 
1908,  41,  1187;  1915,  48,  158),  Rohland  (Ber. 
1907,  40.  2172),  Acres  (Amer.  (Them.  J.  1908, 
39,  628,  649,  789),  Handa  (Ber.  1909,  42, 3179) ; 
and  ef.  Noyes  for  the  physico-chemicflJ  theory  (J. 
Amer.  Chem.  Soc.  1910,  32,  815),  Wegscheider 
(Zeitsch.  physiksi.  Chem.  1915,  90,  641).    ' 

Indicators  may  be  divided  broadly  into  three 
classes:  (i.)  Those  insea^Uve  to  very  weak  adds, 
such  as  carbonic,  boric,  and  hydrosulphuric 
acids ;  these  indicators  comprise  among  others 
methyl  orange,  lacmoid,  cochineal,  and  iSioeoein. 
(ii.)  Those  somewhat  sensitive  to  weak  acids, 
although  as  a  rule  these  acids  cannot  be 
accurately  titrated  with  their  aid ;  if  weak 
volatile  acids  sach  as  carbonic  acid  are  re- 
moved by  boiling,  these  indicators  act  like 
those  of  the  first  class  towards  fairly  strong 
acids  and  bases.  Litmus  is  the  chief  represen- 
tative of  this  group,  (iii)  Those  highly  sensitive 
even  to  weak  acids.  This  class  cont>ams  pAenoI- 
Mhaleln,  turmeric,  and  rosoUc  acid  {v.  Glaeer, 
Zeitsoh.  anal.  Chem.  1899,  38,  273;  Wagner, 
Zeitsoh.  anorg.  Chem.  1901,  27,  238). 


ACID]M£TRY   AND  ALKALIMETRY. 


57 


The  more  important  indicAtora  are  de- 
floiibed  below  in  alphabetical  order. 

Anrin  (Cammo'cidl  or  fora-Eosolic  add) 
is  a  mixture  of  several  sobetancee,  produced 
by  heating  together  phenol  and  ozaiio  and 
solphuiio  aoids;  it  appeals  in  commerce  in 
yeUowish-brown  xesinoiis  hmips.  A  1  p.o.  eola- 
tion in  60  p.0.  alcohol  is  emj^o^^ed,  0*6  cc.  beinff 
added  to  the  sohition  to  be  titrated.  Di  acid 
solution  the  colour  is  pale  ydhw,  in  alkaline 
sdlatian  roM-reci.  This  indicator  is  very  sensi- 
tive and  well'  adapted  for  titrating  barium 
hydroxide  solutions^  out  it  is  affected  by  carbon 
dioxide  and  hydrogen  sulphide. 

Coehineal.  The  oolourixif  matter  in  the 
product  obtained  from  the  £ied  female  insect 
Coccus  cadi  (Linn.),  is  termed  camninic  acid* 
The  best  trade  product,  which  is  called  *  silvex 
cochineal,'  was  fint  recommended  as  an  indicator 
by  Luckow  (J.  pr.  Ghem.  1861,  84,  424 ;  Zeitsoh. 
anal.  Ghem.  1862,  1,  386) ;  3  grams  of  the  sub- 
stance (not  pulverised)  is  extracted  with  2fi0  cc. 
of  dilate  alcohol  (1  voL  alcohol :  ^-4  vols,  water), 
and  the  clear  liquid  decanted.  In  alkaline  solution 
the  colour  is  vtold,  in  acid  ^dUnoiah-red,  Thii 
indicator,  which  is  very  sensitive  to  strong  acids 
and  bases,  is  extremely  useful  in  titrating 
ammonia;  it  is  scarcely  affected  bv  carbon 
dioxide.  The  oolour-ohange  is  well  denned  even 
in  artificial  light.  Cochinral  is,  however,  useless 
for  titrating  oreanio  aoids ;  and  iron,  aluminium 
and  copper  suts  must  be  absent,  since  their 
solutions  remain  pink  even  when  acid. 

Cnreamlll  {Tvmnenc  yeUow).  The  colouring 
matter  from  tho  roots  of  Curcuma  Umga  (Linn.) 
is  turned  yiUov  by  acids  and  reddiahrbrown  by  al- 
kalis ;  it  is  nearly  always  employed  as  a  test-paper ^ 
and  is  useful  in  detecting  ammonia  and  boric  acid. 

GaDefal  (AUmrin  violet,  PyrogaOf^htha- 
iHn),  This  compound,  prepared  by  heating 
together  jpyxogallol  and  phthalio  anhydride 
(Baeyer,  Ber.  1871,  4,  467,  655,  663),  was  pro- 
posed as  an  indicator  by  Deohan  (Pharm.  J.  15, 
849).  A  0-1  p.c.  alcoholic  solution  is  used, 
10  drops  being  added  to  100  c.a  of  liquid.  In 
alkaline  solution  the  colour  is  reddish-violet,  in 
acid  paMfroum,  This  indicator  is  scarcely 
affiected  by  carbon  dioxide,  and  can  be  used  in 
the  accurate  titration  of  organic  acids. 

lodoeoffn  (TdraiodofiuoreseeXnt  Erythroain 
B.).  This  suostanoe,  prepared  by  iodating 
fluorescein,  ii  a  brick-red  powder  soluble  in 
hot  alcohol  or  in  ether,  but  almost  insoluble 
in  water  or  cold  alcohol ;  it  was  first  recom- 
mended by  Mylius  and  Forster  (Ber.  1891,  24, 
1482) ;  0*5  gntm  of  the  sodium  derivative  of 
iodoeosin  ii  (ussolved  in  1  litre  of  water,  2*5  cc. 
are  added  to  the  solution  to  be  titrated  together 
with  5  0.0.  of  chloroform,  the  mixture  being 
shaken  in  a  stoppered  bottle  during  titration. 
While  alkaline  the  aqueous  layer  is  rose  red, 
when  acid  the  aqueous  layer  becomes  colourless, 
and  the  chloroform  assumes  a  yellowish  tint 
(EUms,  J.  Amer.  Chem,  Soc  1899,  21,  359;  M. 
and  F.  used  ether  instead  of  chloroform).  With 
this  indicator,  centinormal  or  even  millinormaJ 
solutions  can  be  titrate'd ;  it  is  indifferent  to  car- 
bon dioxide,  and  phosphoric  acid  can  be  titrated 
as  a  monobasio  add  with  sodium  hydroxide 
(Glucksmann,  Chem,  Zentr.  1902,  (i.)  1181). 
feeble  bases,  such  as  the  alkaloids,  may  also 
be  titrated,  using  iodoeosin  as  indicator. 


Lacmoid  {Resorcin  Blue),  This  substance 
is  obtained  by  heating  gradually  to  110° 
a  mixture  of  100  parts  of  resorcinol,  6  parts 
of  sodium  nitrite,  and  5  parts  of  water.  When 
the  violent  reaction  moderates,  the  mass  is  heated 
to  115*~120*  until  evolution  of  ammonia  ceases. 
Ilie  product  is  a  gUitening  reddish  powder 
(Tranb  and  Hock,  Ber.  1884, 17,  2615).  It  owes 
its  distinctive  properties  to  kumosol,  which  can 
be  isolated  ana  purified  by  a  method  described 
by  Hettinger  (Bioohem.  Zeitsoh.  1914,  65,  177). 
The  turning-point  of  the  pure  indicator  ia  fiu 
sharper  than  that  of  the  orainaijr  preparation. 

A  0*3  p.o.  alcoholic  solution  is  employed ;  a 
better  colour  chsnge  is  produced  if  5  grams  of 
naphthol  green  are  dissolved  in  a  litre  of  thifl 
solution  (&tsoh.  angew.  Ghem.  1890, 3, 163).  In 
iLlVitlmft  solution  the  colour  is  blue;  in  acid, 
red.  Although  these  colour  changes  resemble 
those  of  litmus,  the  indicator  is  more  ulosely 
allied  to  methyl  oran^  It  is  only  slishtly 
affected  by  carbon  dioxide,  although  oirect 
titration  of  carbonates  is  not  satisfaotorv  in 
ookl  solution;  lacmoid  test  paper  may,  how- 
ever, be  used  in  almost  anv  experiment  for 
which  methyl  oran^  is  suitable.  This  indicator 
is  useless  for  oigamc  acids. 

Lttmiu  occurs  in  commerce  in  the  form  of 
small  cubical  granules  mixed  with  a  large  pro- 
portion of  calcium  carbonate  An  aqueous  solu- 
tion of  this  product  not  only  contains  free  alkali, 
but  also  a  variable  proportion  of  colouring 
matters  which  interfere  with  the  delicacy  of  the 
reaction.  Special  precautions  must  therefore  be 
taken  in  preparing  the  solution  for  use  in 
acidimetiT.  Various  processes  have  been  recom* 
mended  by  Berthelot  and  De  Fleurieu  (Ann. 
Ghim.  Phys.  1865,  [4]  5, 189),  Wartha  (Ber.  1876, 
9,  217),  Mohr  (Titrirmethode),  Luttke  (Zeitsoh. 
anal.  Ghem.  1892, 31, 692).  The  following  method 
raves  excellent  results :  The  litmus  is  extracted 
three  or  four  times  with  boiling  methylated 
alcohol  of  85  p.c  in  order  to  remove  the  injurious 
colouring  matters,  the  residue  is  extracted  with 
cold  water,  slightly  acidified  with  sulphuric  acid, 
and  boiled  to  expel  carbon  dioxide.  The  extract 
is  neutralised  with  baryta  water,  a  few  bubbles 
of  carbon  dioxide  passed  in  to  remove  excess  of 
baryta,  and  the  liquid  again  boiled  and  filtered. 
The  solution  should  contain  about  20  jjrams  of 
solid  matter  per  litre,  and  must  be  kept  m  vessels 
to  which  the  air  has  free  access.  If  kept  in 
closed  vessels  it  undergoes  fermentation  and  is 
decolourised.  The  colour  is  restored  when  the 
liquid  is  exposed  to  air.  The  colour  of  the 
solution  should  be  purple ;  it  turns  blue  with 
alkalis,  and  red  wiih  acids,  and  is  affected  by 
carbon  dioxide,  sulphur  dioxide,  and  hydrogen 
sulphide  (For  the  relative  merits  of  litmus  and 
methyl  orange,  v.  Reinitzer,  Zeitsoh.  angew. 
Ghem.  1894,  547,  574;  Lunge,  ibid.  1894, 
733.) 

The  colour  change  is  rendered  more  delicate 
by  conducting  the  titration  in  the  monochro- 
matic light  obtained  by  heating  a  bead  of  sodium 
carbonate  in  a  bunsen  flame  (L.  Henry,  Gompt. 
rend.  1873,  76,  222).  The  red  solution  seems 
colourless,  whflst  the  blue  solution  is  almost  black. 
Litmus  is  not  well  adapted  for  use  by  gas-  or 
lamp-light. 

tttteol.  The  preparation  of  this  substance,  a 
hydroxychlorodij^enylquinoxaline,  is  described 


68 


AOIDTMETRY   AND  ALKALIMETRY. 


by  Autenrieth  (Arch.  Pharm.  1896,  233, 43),  and 
by  Glaess  and  Bernard  (Mon.  Sci.  1900,  U,  809); 
it  forms  fine,  woolly,  yellowish  needles,  m.p.  246*. 
A  0'33  p.c.  alcoholic  solution  is  used  as  an  indi- 
oator.  In  alkaline  solution  the  colour  is  yellow ; 
in  acid  it  is  colourless.  This  indicator  is  said  to 
be  remarkably  sensitive,  excelling  Nessler's  solu- 
tion as  a  test  for  ammonia ;  but  it  is  sensitive 
to  carbon  dioxide  (Higgins,  J.  Soc.  Chem.  Ind. 
1900,  19y  958).  It  was  especially  recommended 
by  Autenrieth  for  use  in  &jehldahl*s  process  {v. 

AsAIjYSIS). 

Methyl  orange  {Helianthin,  Poirrxer*s  Orange 
lll.y  This  substance,  prepared  by  diazotising 
sulphanilic  acid  and  coupling  the  resulting  diazo- 
nium  salt  with  dimethylanuine,  was  introduced 
as  an  mdicator  by  Lunge  (Ber.  1878,  11,  1944 ; 
J.  Soo.  Ohem.  Ind.  1882,  1,  16).  One  gram  of 
pure  methyl  orange  ^either  the  free  acid  or  its 
sodium  salt)  is  dissolved  in  1  litre  of  water,  and 
two  drops  of  this  solution  are  added  in  each 
titration;  if,  owing  to  dilution  during  the 
titration,  the  colour  becomes  too  faint,  another 
drop  of  the  indicator  is  added ;  on  no  account 
should  too  much  indicator  be  used,  since  the 
colour  change,  from  yellow  in  alkaline  to  pink 
in  acid  solution,  is  not  sharp  in  such  circum- 
stances. Methyl  orange  is  exceedingly  useful, 
since  its  indications  are  practically  unaffected 
by  the  presence  of  carbonic,  hydrosulphuric, 
boric,  and  silicic  acids ;  carbonates  and  sulphides 
may  therefore  be  titrated  in  cold  solution  as  if 
they  were  hydroxides.  All  titrations  must  be 
made  with  this  indicator  in  cold  aqueous  solution, 
and,  since  methyl  orange  is  not  very  sensitive  as 
compared  with  various  other  indicators,  the  acid 
or  alkali  employed  should  be  fairly  concentrated. 
It  is  advisable  to  employ  normal  solutions, 
though  with  N/2  or  even  N/5  solutions  it  is 
possible  to  determine  an  end-point  to  within  a 
single  drop.  With  N/10  solutions,  especially 
when  carbonates  are  being  titrated,  there  is  a 
distinct  hroumish  transition  tint  between  the 
yellow  and  pink,  and  results  may  be  uncertain 
to  the  extent  of  one  or  two  drops  (c/.  Kuster, 
Zeitsch.  anorg.  Chem.  1897,  13,  140). 

The  addition  of  indigo-carmine  to  methyl 
orange  has  been  recommended  by  Luther  (Chem. 
Zeit.  1907,  31,  1172),  who  stotes  that  the  colour 
change  is  very  pronounced.  Ethyl  orange  is 
stated  by  Wielana  to  be  even  better  than  methyl 
orange  (Ber.  1883,  16,  1989). 

Methyl  red.  This  substance,  prepared  by 
diazotising  anthranilio  acid  and  coupling  the 
resulting  diazonium  salt  with  dimethylaniline, 
was  introduced  as  an  indicator  by  Rupp  and 
Loose  (Ber.  1908,  41,  3905).  A  0-2  p.o.  alco- 
holic solution  is  employed,  and  two  drops  of 
this  are  added  in  each  titration.  The  colour 
chanjge  is  from  a  pure  yellow  in  alkaline  to  a 
reddish'VioUi  in  aoid  solution,  and  is  very  pro- 
nounced. This  indicator  is  very  sensitive,  and 
can  be  used  for  titrating  weak  bases  in  ccnti- 
normal  solution.  Ordinary  sodium  hydroxide 
solutions  containing  a  little  carbonate  can  be 
accurately  titrated  m  the  cold. 

Accoraing  to  Thomson  (Analyst,  1014,  39, 
518)  methyl  red  gives  a  sharper  end  point  than 
methyl  orange,  and  its  sensitiveness,  unlike 
that  of  methyl  orange,  is  not  greatly  affected 
by  the  presence  of  neutral  salts.  When  methyl 
red  is  used  in  the  titration  of  carbonates,  the 


solution  must  be  boiled  after  each  addition  of 
the  acid,  ^ee  also  Lehmann  and  Wolff,  Arch. 
Pharm.  1917,  255,  113. 

For  observations  on  the  behaviour  of  indi- 
cators of  the  methyl -red  type,  «ee  Howard  and 
Pope,  Chem.  Soc.  Trans.  1911,  1333. 

Phenaeetolln,  first  recommended  by  Degener 
(Zeit.  d.  Ver.  f.  d.  Rubenzucker  Industrie,  1881, 
357  ;  J.  Soc.  Chem.  Ind.  1882, 1,  85),  is  prepared 
by  boiling  together  for  several  hours  molecular 
proportions  of  phenol,  acetic  anhydride,  and 
sulphuric  acid.  The  product  is  extracted  with 
water  to  remove  excess  of  acid,  dried  and  dis- 
solved in  alcohol  in  the  proportion  of  1  gram  to 
500  C.C.  It  is  pale  yellow  with  alkalis,  red  with 
carbonates  of  the  alkalis  and  alkaline  earths, 
colourless  or  pah  ycUoiv  with  acids.  It  is  used 
for  estimating  both  hydroxide  and  carbonate 
when  present  m  the  same  solution. 

Phenolphthalein,  obtained  by  heating  phenol 
with  phthalic  anhydride  and  concentrated- sul- 
phuric acid  (Baeyer,  Annalen,  1880,  202,  09), 
was  proposed  as  an  indicator  by  Luck  (Zeitsch. 
anal.  Chem.  1877,  16,  322).  One  or  two  drops  of 
a  0'5  p.c.  alcoholic  solution  are  used  in  each 
titration.  In  alkaline  solution  the  colour  is  red ; 
the  acid  solution  is  colourless.  Owing  to  its  very 
weak  acid  character,  phenolphthaSsin  is  the 
indicator  par  excellence  for  oi^anio  acids ;  it 
is  useless,  however,  in  the  presence  of  am- 
monium salts,  and  since  even  carbonic  and 
hydrosulphuric  acids  dischaige  the  red  colour, 
it  is  necessary  to  work  with  solutions  free  from 
these  acids  or  titrate  in  boiling  solution ;  hence 
its  use  is  somewhat  restricted  (c/.  McBain, 
Chem.  Soc.  Trans.  1912,  101,  814).  A  con- 
venient method  of  titrating  organic  acids  with 
ordinary  sodium  hydroxide  solutions  using 
phenolphthalein  as  indicator,  is  described  by 
Philip  (Chem.  Soc.  Trans.  1905,  87,  991);  cf. 
McCoy  (Amer.  Chem.  J.  1904,  31,  503);  and 
Schmatolla  (Ber.  1002,  35,  3905). 

Turmeric  r.  Cubcumin. 

Many  other  indicators  have  been  proposed 
from  time  to  time,  among  others  the  following : — 

Alizarin  (Schaal,  Ber.  1873,  6,  1180); 
Alizarin-red  1.  W.S.  (Knowles,  J.  Soc.  Dvers, 
1907,  23»  120) ;  Congo-red ;  cyanine  (Schonbein, 
J.  pr.  Chem.  1865,  95,  449 ) ;  cyanogen  iodide 
(Kastle  and  Clark,  Amer.  Chem.  J.  1903, 30,  87) : 
diaminazoatoluenes^dphonic  acid  (Troeger  and 
Hille,  J.  pr.  Chem.  1903,  68,  297) ;  ferric  salicylate 
(Weiske,  J.  pr.  Chem.  1875,  12,  157;  Wolff, 
Compt.  rend.  1900,  130,  1128;  Gerock,  Chem. 
Zentr.  1900,  ii.  1294) ;  flavescin  (Lux,  Zeitsch. 
anal.  Chem.  1880,  19,  457) ;  fluorescein  (Kriiger, 
Ber.  1876,  9,  1572;  Zellner,  Chem.  Zeit.  Rep. 
1901, 25, 40) ;  homaloxylin  (Wildenstein,  ZeitscL 
anal.  Chem.  1863,  2,  9) ;  tnetanil  yellow  (Linder, 
J.  Soc.  Chem.  Ind.  1908,  27,  485);  tnethyl-S- 
aminoquinoline  (Stark,  Ber.  1907,  40,  3434); 
extract  of  mimosa  flowers  (Robin,  Compt.  rend. 
1904,  138,  1046) ;  para-nitrophenol  (Langbeok, 
Chem.  News,  1881,  43,  161 ;  Spiegel,  Ber.  1900, 
33,  2640  ;  Zeitsch.  angew.  Chem.  1904,  17,  715 ; 
Goldberg  and  Naumann,  2ieitech.  angew.  Chem. 
1903,  16,  644) ;  paranilrcbenzeTieazo-a-naplUhol 
(Hewitt,  Analyst,  1908,  33,  85) ;  and  Poirrier's 
blue  C4B  (En^el,  Compt.  zend.  1886,  102,  214) ; 
2'5' Dinilroqutnol  (Hendenon  and  Forbes,  J. 
Amer.  Chem.  Soc.  1910,  32,  687) ;  di-o-hydroxy- 
styryl  ketone  {lygosin)  (Ferenz) ;    l-osrynapA^- 


ACroiMETBT  AND  ALKALUIETET.  6B 

eitaMMiAnne  (Nierenatein) ;  6-mJpAo-a-iuDAlJt(rf-  |  The  nUtive  BenutiTenioB  ot  the  mon  im- 
l-(uo-m-ij|idnizybe)uotc  actd  (Hellet) ;  2'6-iiiiiiiro-  i  poituit  indiralon  and  their  behaviour  under 
amiiurpltmol  litopicmmie  acid)  (Heldol»  uid  \  vuious  coDditions  have  beea  investigated  by 
Hale) ;  alaarinmonantlphmie  aeid  (ILnowles) ;  I  Wieland  (Ber.  1883,  16,  1989),  and  espeoiaUy 
mgrtU  terry  IVaecinima  myrt/Hiw,  L.)  juice,  the  by  Thomson  (Chem.  Nbwb,  1833,  *7,  123,  135, 
coloniing  matter  of  vhich  ia  ccnocyanin,  the  184 ;  1884,  49,  32,  38,  US  ;  1886,  52.  16,  29), 
ted    colouiing    matter   of   wine  i     red    bettrool  ,  whose  resulta  Me  iummarised  in  the  foUowing 


U  (Chanv 


"1" 
I  ti 


Nmlial. 


.  measured  in  c.c.  of 
decinonnal  acid  lequired  to  produce  t,  distinct 
change  when  the  volume  of  the  liquid  is  100  cc. 
It  should  be  borne  in  mind,  however,  that  the 
.  sensitiveneuofmSiiiy  indicators  changes  (usually 
diminishes)  in  the  preeeuce  of  consideiabU 
quuititiee  of  dissolved  salts.  Where  a  reaction 
is  given  as  *  indefinite,'  it  ia  not  meant  that  there 
is  no  effect,  but  that  the  chalige  is  not  suffi- 
ciently sharp  to  be  available  in  analysis.  In 
many  c»sea  where  the  reaction  is  indefinite  in 
cold  BohitiouB  it  becomes  definite  if  the  liquid 
is  boiled,  e.g.  litmus  with  sulphides,  sulphites, 
and  cubooat^B ;  phenolphtbalein  with  sulphides 
and  carbonates.  Locmoid  is  most  serviceable 
in  the  form  of  paper,  and  several  of  the  reactions 
which  are  unaatiafactorv  vath  the  solution  are 
■harp  and  di^nct  witJi  the  paper,  r!q.  with 
cAfbonates,  sulphides,  and  sulphites. 

Gawstowski  recommends  (Zeitach.  ansl. 
Chem.  1S83,  22,  397)  the  use  of  a  mixture  of 
methyl  oraiue  and  phenolphthsleln,  which  is 
deep-red  with  excess  of  allisJi,  pale.yellow  when 
neutral,  and  rose-red  with  excess  o(  acid.  Com- 
pare also  Schloti  IZeitsch.  Elek.  Chem.  1904,  10, 
649)  on  mixed  indicators. 

Walpole  (Biochem.  J.  1914,  8,  628)  gives 
•  chart  of  hydrogen  ion  concentration  data 
representiilg  the  sensitive  ranges  of  all  the 
indicators  m  general  use,  both  in  colorimetric 
and  '  end-point '  prooewe*. 

PnpHstkm  of  Btasdaid  AcMi  ud  AUuUi. 

Standard  lolutiona  of  acids  and  alkalis  are 
usually  prepared  on  the  normal  basis,  the  ■aormai 
solution  of^a  chemical  reagent  containing  one 
gram^equivalent  of  the  aubstance  in  one  litre  of 
the  eolation  {v.  AvALTBia,  Volumetric  section). 


ardin  the  others.  Various  suitgestions  have 
been  made,  but  the  general  choice,  at  least  for 
teohnioal  purposes,  has  fallen  on  hydrochlorja 
acid  as  the  etandard  acid;  sulphuric  acid  is 
frequently  employed  and,  lest  often,  oxalic  acid. 
The  commonest  method  of  fixing  the  exact 
oonoentration  of  the  bydrochtorio  (or  sulphuric) 
aoid  oooslsts  in  titrating  the  acid  against  weighed 
amounts  of  pure  anhydrous  sodium  carbonate, 
a  process  onginaLy  employed  by  Gay-Lussao, 
and  stronsly  recommended  by  Lunge,  Sutton, 
and  Treadwell.  Separate  weighed  quantities  of 
the  pure  carbonate  are  dissolved  in  SO-IOO  o.o. 
of  cold  distilled  water,  and  each  titrated  with 
the  acid,  using  methjl  orange  as  indicator.  The 
concentration  of  the  acid  solution  is  calculated 
from  each  result,  and  the  mean  of  the  concordant 


and  should  be  free  from  all  but  traoes  of  chloride 
and  sulphate  ;  it  is  dried  in  a  platinum  crucible 
with  continual  stirring  for  20-30  minutes  at 
BUoh  a  temperature  that  the  crucible  bottom  is 
barely  red  hot,  or  the  crucible,  embedded  in 
sand,  ma^  be  heated  at  300*  for  half  an  hour. 
Pure  sodium  carbonate  may  also  be  prepared 
by  beating  the  bicarbonate  at  a  temperature 
not  exceeding  300*  (Lunge.  Zeitscb.  ansew. 
Chem.  1S97,  10,  622).  Sulphates  and  chlorides 
are  removed  from,  the  bicarbonal«  by  washing 
with  cold  water.  (For  the  preparation  of  pure 
sodium  bicarbonate,  v.  Bcinitzor  (Zeitsch.  angew. 
Chem.  1894,  7,  Ofil),  and  North  and  Blakey  (J. 
Soc.  Cbem.  Ind.  1906,  24,  396).) 

The  foregoing  method,  although  extensively 
used,  has  been  adversely  criticised,  the  chief 
objeotion  being  that  it  is  impossible  to  dehydrate 
the  carbonate  or  bioarbonate  without  losing  a 
httle  too  much  oarbon  dioxide.  It  is  asserted 
that  sodium  oxide  is  present  even  when  the 
temperature  of  drying  tias  not  exceeded  170*  ; 
V.  Kissing  (Zeitaoh.  angew.  Chem.  1890,  3,  262)] 


60 


ACIDIMETRY  ANI)  ALKALMETRY. 


HigginA  (J.  Soc.  Chem.  Ind.  1900,  19,  068); 
Sorenson  and  Andersen  (Zeitsch.  anal.  Chem. 
1905,  44,  166);  North  and  Blakey  (J.  Soc. 
Chem.  Ind.  1906,  24,  396);  Sebelin  {Chem. 
Zeit.  1906,  29,  638);  but  c/.  Seyda  (Chem. 
Zentr.  1899,  (i.)  1164);  Lunge  (ZeitoolL  anaL 
CheoL  1904,  17,  231 ;  1906,  18,  1620). 

A  satiBfactory  method  of  checking  the  values 
obtained  by  the  carbonate  method  depends  on 
the  fact  that  sodium  oxalate,  when  heated,  is 
converted  into  sodium  carbonate.  As  this 
oxalate  can  be  prepared  in  a  high  degree  of 
purity,  the  residue  of  carbonate  theoretically 
obtainable  from  a  known  weight  of  oxalate  can 
be  calculated*  and  the  presence  of  any  sodium 
oxide  is  immaterial  providins  that  all  calcula- 
tions are  baaed  on  the  original  weight  of  sodium 
oxalate. 

The  weighed  oxalate  is  carefully  heated  in 
a  platinum  crucible  until  all  the  separated  carbon 
has  been  burnt  off  and  the  refiidual  carbonate 
begins  to  fuse ;  the  cooled  residue  is  dissolved 
in  water  and  titrated  as  already  described ;  v. 
Sorensen  (Zeitsch.  anal.  Chem.  1897,  36,  639: 
1903,  42,  333,  612;  1906,  44,  166),  Lunge 
(Zeitsch.  angew.  Chem.  1906,  18,  1620);  and 
Analysis,  (Volumetric  section,  standardisation 
of  permanganate). 

From  time  to  time  many  other  standards 
have  been  proposed,  and  among  others  the 
following : — 

Potassium  tdroxalaU  ;  succinic  acid  (Phelps 
and  Hubbard,  Zeitsch.  anorg.  Chem.  1907,  63, 
361;  Phelps  and  Weed,  ibid,  1908,  69,  114, 
120);  borax  (Rimbach,  Ber.  1893,  26,  171); 
potassium  hydrogen  tartrate  (Bomtrager,  Zeitsch. 
anaL  Chem.  1892,  31,  43);  potassium  dichromate 
(Richter,  Zeitsch.  anaL  Chem.  1882,  21,  206); 
potassium  iodate  (Fessel,  Zeitsch.  anaL  Chem. 

1899,  38,  449);  potassium  biiodate  (Meineke, 
Oiem.  Zeit.  1896,  19,  2);  sodium  (Hartley, 
ChenL  Soc.  Trans.  1873,  26,  123;  Neitzel, 
Zeitsch.  anaL  Chem.  1893,  32,  422;  cf.  Hopkins, 
J.  Amer.  Chem.  Soa  1901,  23,  727);  and 
sulphuric  acid,  prepared  by  electrolysing  copper 
sulphate  solution  (Hart  and  Croasdale,  Chem. 
News,  1891,  63,  93;  Kohn,  J.  Soc.  Chem.  Ind. 

1900.  19,  962). 

Hydroehlorie  aeliL  In  preparing  a  normal 
solution  advantage  may  be  taken  of  the  fact 
that  an  aqueous  solution  of  hydrogen  chloride 
which  boils  at  a  constant  temperature  has  a 
practically  constant  composition.  A  quantity 
of  ordinary  concentrated  acid  is  distilled  from  a 
capacious  retort  until  one-third  has  passed  over. 
The  residual  liquid  will  contain  20-2  p.c.  of 
hydro^n  chloride,  and  166  c.c  when  diluted 
to  1  htre  will  form  an  almost  exactly  normal 
solution ;  it  should  be  standardised  by  one  of 
the  following  processes. 

The  strong  acid  is  diluted  until  its  specific 
gravity  is  approximately  M;  and  distilled;  after 
three-fourths  of  liquid  have  passed  over,  the 
remaining  distillate  is  collected  apart,  and  the 
barometnc  height  observed.  The  final  quarter 
of  the  distillate  is  of  perfectly  definite  com- 
position, and  the  following  table  gives  the  actual 
content  of  hydn^n  chloride  for  a  definite  baro- 
metric height,  together  with  the  weight  of 
distillate  which  contains  one  gram-equiv<3ent  of 
hydrogen  chloride,  i.e.  which  yields  a  normal 
solution  when  diluted  to  1  litre : — 


Barometer 
770 
760 
760 
740 
730 


20-218 
20-242 
20-266 
20-290 
20-314 


Orami  of  naixtnre  ocm- 
tainins  1  moL  Hd 
180-390 

180170 

179-960 

179-746 

179*630 


These  results  were  calculated  from  the 
observed  weights  of  liquid,  without  reduction 
to  vacuum  standard;  the  compositions  were 
determined  gravimetrically  by  precipitation  as 
silver  chloride  (Hulctt  and  Bonner,  J.  Amer. 
Chem.  Soc.  1909,  31,  390). 

The  simplest  method  of  preparing  a  large 
quantity  of  nearly  normal  hydrochlOTC  acid  is 
to  find  the  approximate  composition  of  the 
ordinary  concentrated  acid  by  takinff  its  specific 
gravity  with  a  hydrometer  and  referring  to  a 
suitable  table;  the  requisite  Quantity  of  the 
acid  is  then  measured  out  and  appropriately 
diluted  with  distilled  water. 

To  standardise  the  solution,  it  is  titrated 
against  successive  weighed  quantities  of  pure 
sodium  carbonate  (or  sodium  oxalate),  as  de- 
scribed above.  Each  separate  amount  of  car- 
bonate should  weigh  from  2*0  to  2*6  grams,  in 
order  to  ensure  a  burette  reading  of  40  to 
60  C.C.  It  is  best  to  use  methyl  orange  for 
indicator,  since  the  titrations  can  be  rapidly 
and  accurately  carried  out  in  the  cold  ;  if  litmus 
is  used,  the  titration  must  be  made  in  boiling 
solution.  In  the  latter  case,  it  is  quicker  to  add 
a  measured  excess  of  acid  to  the  carbonate, 
and  titrate  back  with  sodium  hydroxide  the 
value  of  which  is  known  in  terms  of  the  aeid ; 
but  the  titration  must  nevertheless  be  done  in 
boiling  solution.  The  calculation  ia  very  simple : 
if  X  grams  of  sodium  carbonate  require  y  co.  of 
hydrochloric  acid,  then  1  c.c.  acid  s  x/y  grams 
of  sodium  car]>onate.  Now,  1  cc.  I?- acid 
SB 0-06300  grams  sodium  carbonate,  and  hence 

concentration  of  acid  bi  ^  ^v.^-    times  norma] 

0-063y 

=z  times  normal,  say.    As  a  rule,  this  is  a  very 

oonvenient  method  of  expressii^;  the  result; 

e.g.  if  the  acid  is  used  to  estimate  an  alkali  of 

equivalent  e,  then  1  cc.  acid  a  — ~  x  z  grams 

of  alkalL  If  necessary,  the  acid  solution  may 
be  diluted  with  distilled  water  so  that  the  ratio 
final  volume  -}-  initial  volume  =3  z ;  it  will  then 
be  exactly  nbrmaL  A  simple  arithmetical  calcu- 
lation is  required,  and  it  this  process  is  con- 
templated, care  should  be  taken  initially  to  en- 
sure that  2  shall  be  slightly  greater  than  unity. 

Hydrochloric  acid  is  most  accurately  staad- 
ardised  gravimetrically  by  precipitating  chlorine 
with  excess  of  silver  nitrate  and  weighing  the 
silver  chloride  in  a  Qooch  crucible.  The  solution 
may  be  titrated  affainst  pure  silver  according  to 
the  Mint  process  for  assaying  this  metaL  The 
method  may  be  modified  by  adding  the  silver 
solution  in  very  slight  excess,  this  excess  being 
determined  in  the  filtrate  with  N/10-thiocyanate 
(Thorpe's  Quantitative  Analysis;  Dittmar's 
Quantitative  Analysis ;  Knorr,  J.  Amer.  Chem. 
Soc.  1897,  19,  814;  Hopkins,  ibid.  1901,  23, 
727).  These  methods  are  trustworthy  only 
when  the  hydrochloric  acid  is  free  from  chlorides* 

The  following  method  depending  on  the 
loss  of  weight  on  converting  silver  nitrate  into 
chloride  is  due  to  Andrews  (J.  Amer.  Chem.  Soc 


AOTDIMETRY   AND  ALKALIMBTRT. 


6) 


N= 


1914,  3tt»  2089).     Two  ttmUAr  BiUea  dishes  are 

provided  with  watoh-glass  coven,  and  one  of 

them  with  a  Btiiiing-rod,  short  enough  to  lie 

under  the  cover.     Into  this  dish  about  2  grams 

silver  nitzate  are  put,  and  both  dishes  are  placed 

in  an  oven  at   160^,   the  temperature  being 

subsequently  raised  to  244°.    After  cooling  in 

a  desiccator,  both  dishes  are  weighed.    Inlty 

N 
c.c  of  =-  hydroohlorio  add  to  be  standardised 

are  run  into  each  dish,  the  contents  of  which 
are  then  evaporated  on  the  water-bath,  and 
finally  dried  at  240°.  The  normality  of  the 
solution  is  given  by  the  expression  : 

0-02666V 

in  which  ¥=*=  volume  d  acid  delivered  by  the 
50  c.a  pipette;  W= weight  in  air  of  silver 
nitrate  and  diidi,  Wi»weight  of  dish  with 
mixed  chloride  and  nitrate,  10= weight  of 
control-dish  before,  and  toi  its  weight  after 
experiment  (Analyst,  1815, 24). 

A  simpla  and  accurate  process  of  standardisa- 
tion consists  in  immersing  weighed  pieces  of  Ice- 
land spar  in  a  measured  volume  of  the  acid,  and 
noting;  the  loss  in  weight  of  the  spar  after  the 
acid  IS  neutralised  (Masson,  Chem.  News,  1900, 
81,  73  ;  Green,  ibid,  1903,  87,  5 ;  c/.  Thiele  and 
Richter,  Zeitsch.  angew.  Chem.  1900,  13,  486). 

Small  quantities  of  standard  hydrochloric 
acid  may  be  prepared  by  absorbing  dry  hydrogen 
chloride  in  a  weighed  quantity  of  water  and 
ascertaining  the  morease  in  weight  (Moody, 
Chem.  Soc.  Trans.  1898,  73,  658;  Higgins,  J. 
Soc  Chem.  Ind.  1900,  19,  958;  Acree  and 
Brunei,  Amer.  Chem.  J.  1906,  36,  117). 

Solphlirte  aeld.  An  approximately  normal 
solution  is  obtained  by  diluting  to  1  litre  28  o.c. 
of  pure  concentrated  sulphuric  acid  (sp.gr.  1-84). 

The  solution  may  be  standardised  with  pure 
sodium  carbonate  or  oxalate  {v.  Htdboghlobio 
Acn>),  or  a  measrued  quantity  treated  with  a 
slight  excess  of  ammonia,  evaporated  to  dryness, 
and  the  residual  ammonium  sulphate  heated  at 
120*  and  weighed.  This  method  |;ives  trust- 
worthy results  only  when  pure  redistilled  acid 
is  employed  in  preparing  the  solution  (Weinig^ 
ZeitscL  angew.  Chem.  1892,  5,  204;  Shiver, 
J.  Amer.  Chem.  Soc.  1895,  17,  351 ;  Hopkins, 
ibid.  1901,  23,  727;  Marboutin  and  P^coul, 
Bull.  Soc.  chim.  1897,  17,  880). 

A  measured  volume  of  the  acid  is  added  to  a 
weighed  excess  of  sodium  carbonate  in  a  platinum 
disl^  the  solution  evaporated,  the  residue  dried 
at  300^  and  weighed.  The  change  in  weight  due 
to  the  transformation  of  sodium  carbonate  into 
sulphate  indicates  the  amount  of  acid  present  in 
the  solution.  This  method  is  much  preferable 
to  precipitating  and  weighing  the  acid  as  barium 
£uu)hate  (Thoxpc^  Quantitative  Analysis,  1873. 
{Of.  Richardson^  J.  Soc.  Chom.  Ind.  1907, 26, 78.) 

Sulphuric  acid  solutions  of  definite  concentra- 
tion may  be  prepared  by  specific  gravity  measure- 
ments (Pickering,  Chem.  Soc.  Trans.  1890,  57, 
64).  A  quantity  of  the  purest  acid  is  diluted  with 
half  its  volume  of  water,  and  the  specific  gravity 
of  the  mixture  accurately  determined  at  15^  or 
18*  in  a  SprenfEcl  pyknometer.  The  percentage 
of  sulphuric  acid  in  the  solution  is  then  obtained 
by  reference  to  tables  giving  the  values  for 
16VI5'    or     187J8*    (r.    Sutton's    Volumetric 


Analysis,  9th  ed.,  or  J.  Soa  Chem.  Ind.  1899, 18, 
4).  The  table  nven  in  J.  Soo.  Chem.  Ind.  1902, 
21,  1511,  may  De  employed  when  the  specific 
gravity  (15715")  has  been  calculated  without 
introducing  any  vacuum  corrections,  which 
must  be  allowed  for  if  the  other  tables  an 
employed.  Between  the  limits  of  66  p.c.  and 
81  p.c.^  the  foUowing  formulas  reproduce  the 
values  in  the  tables  with  an  error  not  exceeding 
004  p.a :—  * 

P  «  86  S„- 69-00 
P  =  86  Si, -68-82 

where  P  =  peroentage  of  sulphuric  acid,  and 
Big  and  S,,  =  the  specific  gravities  referred  to 
water  at  15*  and  18*  respectively,  calculated 
without  allowing  for  *  air  displaced  '  (Marshall, 
J.  Soc.  Chem.  Eid.  1899,  18,  4).  The  diluted 
acid  may  be  kept'  in  a  stoppered  bottle  without 
change,  and  by  weighing  out  the  appropriate 
amoimtand  diluting  to  a  utre,  a  normal  solution 
of  sulphuric  acid  can  be  rapidly  prepared. 

Oxalle  aeid.  A  normal  solution  is  prepared 
by  dissolving  63-02  grams  of  the  recrystaUised 
hydrated  acid  H.CjO^-f  2H,0  in  water  and 
diluting  to  1000  c.c.  As  the  crystallised  acid 
is  somewhat  effloresent,  especiaUy  on  slightly 
warming,  it  may  contain  less  than  two  molecular 
proportions  of  water.  The  solution  may  be 
checked  against  a  standard  alkali,  using  phenol- 
phthaleln  as  indicator,  or  against  an  accurately 
standardised  permannnato  solution  (c/.  Tread- 
well-HaU,  Analytical  Chemistry,  voL  2). 

Oxalic  acid  solutions  do  not  keep  veary  well. 
A  small  qnantitv  of  metallic  mercury  a(&ed  to 
the  solution  tends  to  stabilise  it. 

Sodlam  hydroxide.  To  prepare  a  normal 
solution,  clear  transparent  lumps  of  the  best 
white  commercial  caustic  soda  aro  selected,  any 
opaque  portions  of  their  surface  scraped  off,  and 
50  grams  of  the  substance  weighed  out  for  each 
litro  of  solution.  The  cooled  solution  is  stand- 
ardised against  the  standard  hydrochloric  acid, 
using  methyl  orange  as  indicator,  and  taking 
50  C.C.  for  each  titration. 

For  the  preparation  of  sodium  hydroxide 
solutions  free  rrom  carbonate,  v.  Kuster  (Zeitsch. 
anorg.  Chem.  1897,  13,  134  ;  1904,  41,  472,  and 
Bousfield  and  Lowry,  Phil.  Trans.  1905, 204, 253). 

Potasaliim  hydroxide  cf.  SonnTM  hydboxidb. 

Barium  hydroxide.  An  approximately  N/10- 
solution  is  best  prepared  m>m  the  crystelline 
hydroxide  Ba(OM)„  6H.0.  The  powdered  sub- 
stance is  shaken  with  distiUed  water,  the  solu* 
tion  allowed  to  settle,  the  clear  liquid  siphoned 
off  and  diluted  with  an  equal  volume  of  recently 
boiled-out  water.  The  solution  must  be  kept 
permanently  in  contact  with  that  portion  alreaay 
in  the  burette,  and  guard  tubes  are  required 
to  prevent  access  of  carbon  dioxide.  The 
solution  is  stendardised  against  succinic  acid, 
phenolphthaldn  being  used  as  indicator;  or  a 
measured  volume  may  be  Evaporated  to  drvness 
with  a  slight  excess  of  pure  sulphuric  acicf,  the 
residual  barium  sulphate  being  gently  heated 
and  weighed. 

The  chief  use  of  this  solution  is  in  titrating 
organic  acids,  using  phenolphthalein  as  indicator. 
For  this  purpose  carbon  dioxide  must  be  ex- 
cluded, and  barium  hydroxide  is  consequently 
the  most  convenient  alkali  to  employ. 


69 


ACIDMETRY  AND  ALKALIMETRY. 


AmmonUu  This  aolation  is  not  often  em- 
ployed ;  an  approximately  semi-normal  solntiont 
readily  obtained  by  diluting  28  c.c.  of  conesn- 
trated  ammonia  solution  to  1  litre,  is  titrated 
against  hydrochlorio  acid  in  the  cold,  using 
methyl  orange  as  indicator;  phenolphthaltin 
cannot  be  employed. 

Schultze  has  determined  the  rates  of  expan- 
sion of  normal  solutions  of  acids  and  alkalis 
and  other  solutions  employed  in  volumetric 
analysis  (Zeitsch.  anaL  Chem.  1882,  21,  170). 
The  following  are  the  results  for  average 
temperatures : — 


l(f 
16* 
20* 
25' 


OxaUesdd 


Hydro- 
chloric add 


10000 
10010 
10019 
10031 
10046 


10000 
10010 
10019 
10030 
10043 


mtrfcadd 


10000 
10018 
10031 
10045 
10061 


- 

Solphuric 
add 

PotUBium 
hydroxide 

Sodium 
hydroxide 

10* 
15* 
20» 
26* 

10000 
10017 
10029 
10044 
10060 

10000 
10019 
10031 
10046 
10062 

10000 
10021 
10034 
10048 
10065 

Typical  AdDmsTBio  avd  At,kat.tmetsio 

ESTDCATIONS. 

Detarmlnitloii  of  total  aUoUL  A  weighed 
quantity  of  the  substance  (10  grams)  is  dissolved 
in  water,  filtered  if  necessary,  and  diluted  to 
500  C.C. ;  50  ac.  are  withdrawn,  mixed  with  a 
measured  excess  (25  c.c.)  of  normal  acid,  boiled 
gentlv  for  ten  minutes  to  expel  carbon  dioxide, 
and  the  excess  of  acid  determined  with  standard 
alkali.  The  volume  of  standard  acid  minus  the 
excess  of  acid  gives  the  volume  of  acid  required 
to  neutralise  the  total  alkali,  t.e.  the  alkali 
present  as  hydroxide,  carbonate,  sulphide, 
sulphite,  thiosulphate,  aluminate,  and  silicate. 
If  methyl  orange  is  used  as  indicator,  boiling^  is 
unnecessary,  and  the  alkaline  solution  is  titrated 
directly  with  standard  acid.  If  direct  titration 
with  litmus  as  indicator  is  preferred,  the  solution 
must  be  continuouslv  boiled  during  the  titration. 

•Alkaline  hydroxide  in  presenee  of  earbonate. 
100  C.C.  of  the  above  solution  are  heated,  mixed 
with  excess  of  barium  chloride,  allowed  to  cool, 
dfluted  to  250  c.c.  and  well  shaken.  When  the 
precipitate  has  settled,  50  c.o.  of  the  dear  liquid 
are  withdrawn  and  titrated  with  standard  acid. 
The  quantity  of  acid  used  X  25  gives  the  volume 
equivalent  to  the  hydroxide  in  the  weight  of 
substance  originally  taken.  The  reaction  which 
takes  place  is  expressed  by  the  equation 

rMtOO,  -f-  yMOH  -f  (x  -f?)Baa, 

—  «Ba(X),-f  |BaH,0,  -f  (2*4-  y  )Ma 

The  barium  carbonate  is  precipitated  and  a 
quantity  of  barium  hydroxide  equivalent  to  the 
ailcaiine  hydroxide  remains  in  solution.    The 


solution  cannot  be  filtered,  since  the  barium 
hydroxide  would  absorb  carbon  dioxide  from  the 
air  with  formation  of  the  insoluble  carbonate. 

In  order  to  avoid  error  due  to  the  presence  of 
the  precipitate,  and  to  economise  time,  Watson 
Smith  (J.  Soc.  Chem.  Ind.  1882,  1,  85)  prefers  to 
add  just  sufficient  barium  chloride  to  precipitate 
the  carbonate  without  affecting  the  hydroxide. 
No  barium  remains  in  solution,  and  even  if  car- 
bon dioxide  is  absorbed  the  alkaline  carbonate 
formed  remains  in  solution.  The  barium 
chloride  is  added  gradually  to  the  hot  solution 
until  precipitation  is  just  complete,  and  the 
liquid  is  iiltered  into  a  250  c.c.  flask  and  an 
aliquot  portion  titrated.  It  is  preferable  for  the 
liquid  containing  the  precipitate  to  be  diluted  to 
260  C.C.,  the  precipitate  allowed  to  settle,  and 
50  0.0.  of  the  supernatant  liquid'  withdrawn. 
(For  various  details  and  precautions,  v.  SorenaeD 
and  Andersen,  Zeitsch.  axud.  Chem.  1908, 47, 279. ) 

Carbonate  In  presenee  of  hydroxide.  The 
solution  is  coloured  a  very  faint  yellow  with 
phenacetolin,  and  standard  acid  is  added  until 
the  yellow  colour  changes  to  a  rose  tint.  The 
volume  of  acid  required  gives  the  amount  of 
hydroxide  present.  A  furUier  quantity  of  acid 
is  now  added,  and  the  red  colour  increases  in 
intensity,  but  eventually  changes  to  yellowish- 
red,  and  finally  to  golden-yellow.  At  this  point 
a  second  reading  is  taken,  and  the  difference 
between  this  and  the  first  reading  gives  the 
volume  of  acid  corresponding  with  the  carbonate 
pnresent  (Lun^,  J.  Soa  Chem.  Ind.  1882,  1,  56). 
This  method  is  not  available  for  the  estimation 
of  small  quantities  of  hydroxide  in  presence  of 
large  quantities  of  carbonate  (Thomson). 

The  following  method,  due  to  Warder,  gives 
fairly  satisfactory  results:  To  the  cold  cmute 
solution  phenolpnthalein  is  added  and  standard 
hydrochloric  acid  run  in  slowly,  the  burette  tip 
being  immersed  in  the  liquid,  till  decolourisation 
takes  place.  This  occurs  when  all  the  hydroxide 
and  Mlf  the  carbonate  have  been  neutralised. 
Methyl  orange  is  then  added  and  the  solution 
titrated  again  till  an  acid  reflection  is  indicated. 
If  this  second  titration  requires  y  cc.  and  the 
first  one  x  cc,  then  the  carbonate  is  equivalent 
to  2yo.c,  and  the  hydroxide  iox^y  cc  (KCister, 
Zeitsch.  anorg.  Chem.  1896,  13,  127;  Lunge, 
Zeitsch.  angew.  Chem.  1897,  10,  41 ;  North  and 
Lee,  J.  Soc  Chem.  Ind.  1902,  21,  322;  ef, 
Cameron,  Amer.  Chem.  J.  1900,  23,  471). 

In  order  to  estimate  the  proportion  of  car- 
bonate in  quick-lime  or  slaked  lime,  the  purpoee 
for  which  j^enacetolin  was  originally  recom- 
mended by  JD^ener,  100-150  grams  of  the  lime 
aro  made  into  a  cream  with  water  and  diluted 
to  500  cc.  After  vigorous  fuiitation  100  cc  are 
withdrawn  and  diluted  to  1000  cc,  axA  25  cc 
of  this  liquid  are  taken,  mixed  with  phenacetolin, 
and  standard  acid  added  until  a  pale-rose  tint  is 
obtained.  In  order  to  estimate  both  hydroxide 
and  carbonate,  the  substance  is  dissolved  in 
standard  acid  and  the  excess  of  acid  deter- 
mined by  reverse  titration  in  the  usual  way 
(Lunge,  (x.). 

Acid  earbonate  in  presence  of  normal  car- 
bonate. The  cM  and  diltUe  solution  of  normal 
carbonate  and  acid  carbonate  is  mixed  with 
phenolphthalein,  and  standard  acid  added,  the 
burette  tip  dippine  into  the  liquid  to  prevent 
[  escape  of  carbon  dioxide,  until  the  liquid  be- 


ACIDIMBTRY  AND  ALKALIMETRY. 


63 


comet  colourless.  At  this  point,  which  cone- 
sponds  with  the  complete  conversion  of  the 
normftl  carbonate  into  acid  carbonate,  the  volume 
of  acid  added  is  read  o£F.  The  liqnid  is  then 
boiled  and  acid  is  added  gradually  nntil  the 
solution  remains  colourless  even  after  Ions 
boiling,  and  the  volume  of  acid  is  again  read 
off.  If  X  represents  the  first  readins,  and  y  the 
second  reading,  then  2x  =  the  normu  carbonate, 
and  y—2xsss  the  acid  carbonate  (Warder,  Chem. 
News,  1881,  43,  228). 

Lunge  (J.  Soc  Chem.  Ind.  1882,  1,  67) 
proposes  a  different  method  based  on  the 
reaction: 

•M  aOOa  +  yMHG03  +  zlTHg  +  (« -f  y)BaCl2 

s(Ss  •!•  y)MCl  +  yNH^Ol  +  {.a  +  v)BaCOs  -h  (i  -  y}KHs. 

The  solution  to  be  tested  is  mixed  with  a  mea- 
sured excess  of  standard  (half -normal)  ammonia, 
exoeas  of  barium  chloride  added,  and  the  liquid 
diluted  with  recently  boiled  water  to  a  definite 
Tolnme.  When  the  precipitate  has  settled,  an 
alioQOt  portion  of  the  clear  liquid  is  withdrawn 
and  titrated  with  standard  acid  in  order  to  as- 
certain the  excess  of  ammonia.  The  difference 
between  the  volume  of  ammonia  added  and  that 
remaining  after  precipitation  gives  the  volume 
coxresponding  with  the  quantity  of  acid  carbonate 
in  the  liquid  analysed. 

By  aading  a  definite  excess  of  pure  sodium 
hydroxide  free  from  carbon  dioxide,  a  mixture 
of  normal  carbonate  and  hydroxide  is  obtained 
which  may  be  analysed  as  described  above. 

Aminoilia*  In  order  to  determine  the  quan- 
tity of  free  ammonia  in  a  solution  of  the  gas,  an 
accurately  measured  quantity  (10  o.c.)  of  the 
liquid  is  transferred  to  a  light  tared  flask,  and 
weighed.  This  gives  at  once  the  weij;ht  taken 
for  analysis  and  the  8p.gr.  The  liquid  is  then 
titrated  with  standard  acid  in  the  usual  way, 
using  litmus,  lacmoid,  or  methyl  orange  as 
indicator. 

Ammonia  in  combination  is  determined  by 
boiling  the  substance  with  sodium  hydroxide, 
leading  the  ammonia  into  a  measured  excess  of 
standard  acid,  and  determining  the  residual  acid 
with  standard  alkali.  The  substance  is  weighed 
into  a  flask  fitted  with  a  cork,  through  one  nole 
in  which  passes  a  pipette  containing  a  strong 
solution  of  sodium  hydroxide,  whilst  throusb 
another  passes  a  tube  leading  to  a  flask  or  bmb 
U-tube  containing  a  known  volume  of  standard 
acid.  The  flask  or  U-tube  is  fitted  with  a  cork 
which  carries  a  calcium  chloride  tube  containing 
beads  moistened  with  some  of  the  acid  in  order 
to  ensure  complete  absorption  of  the  ammonia. 
After  addition  of  the  sodium  hydroxide  solution 
the  liquid  is  gently  boiled  for  half  an  hour,  and 
the  residual  acid  determined.  From  the  volume 
of  acid  which  has  combined  with  the  ammonia 
the  quantity  of  the  latter  is  readily  calculated. 
The  sodium  hydroxide  may  be  replaced  by  milk 
of  lime,  and  the  most  effectual  method  of 
removing  the  ammonia  is  to  distil  the  mixture 
in  steam.  The  use  of  magnesia  in  place  of 
sodium  hydroxide  is  not  advantageous  (Kober, 
J.  Amer.  Chem.  Soc  1008,  30,  1279).  (For  a 
different  method  of  distilling  off  the  ammonia, 
V.  Kober  (J.  Amer.  Chem.  Soa  1908,  30,  1131). 
See  also  Ronchftse  (J.  Pharm.  Chim.  1907,  25, 
611)  and  Wilkin  (J.  Soa  Chem.  Ind.  1910,  29,  6) 
for  a  method  of  estimation  entirely  different  in 
princijde  from  the  foregoing.) 


Hydroehlorle,  Hydrobromle,  Hydrfodle,  Sul- 
phuric, and  Nltrlo  acids  are  readily  estimated  by 
direct  titration  with  standard  alkali,  using  methyl 
orange  as  indicator. 

Oxalie,  Tutarie,  CItrie,  Acetie,  and  Laetle 
acids  can  likewise  be  titrated  accurately  with 
standard  alkali  if  phenolphthalefn  is  used  as  the 
indicator  (Thomson,  l.c).  Oxalic  acid  may  also 
be  titrated  using  litmus  as  indicator. 

Borie  aeld  ^ives  no  very  definite  reaction 
with  the  majority  of  indicators,  but  it  is  quite 
neutral  to  methyl  orange,  and  hence  the  quantity 
of  alkali  in  akaline  lK>rates  can  be  accurately 
estimated  by  direct  titration  ^ith  standard  acid 
if  methyl  orange  is  used  as  indicator  (Thomson). 

The  titration  of  boric  acid  itself  becomes 
possible  if  the  solution  contains  at  least  30  p.c. 
of  its  volume  of  slyoerol.  The  boric  acid  then 
behaves  towards  pnenolphthalein  as  a  monobasic 
acid  (Thomson,  J.  Soc.  Chem.  Ind.  1803, 12, 432 ; 
JoTgensen,  Zeitsch.  angew.  Chem.  1897,  10,  6; 
Honig  and  Spitz,  ibid.  1896,  9,  049 ;  Copaux, 
Compt.  rend.  1898,  127,  766).  A  similar  result 
is  effected  by  saturating  the  solution  with 
mannitol.  Since  phenolpnthalein  is  employed, 
carbon  dioxide  must  not  be  present  in  the 
solutions  to  be  titrated  (Jones,  Amer.  J.  Sci. 
1898,  7,  147;  Stock,  Compt.  rend.  1900,  130, 
616). 

Sulphurous  aeid  can  be  titrated  directly  if 
methyl  orange,  phenolphthalefn,  or  aurin  is  used 
as  indicator  (Lunge,  Dingl.  poly.  J.  260,  630). 
With  methyl  orange  the  hydrogen  sulphite 
MHSO.  is  the  neutral  salt,  whilst  with  the  other 
two'inoicators  the  normal  salt  is  neutral.  This 
difference  can  be  utilised  for  the  determination 
of  the  relative  proportions  of  normal  and  acid 
sulphite  in  the  same  solution  (Blarez,  Compt. 
rend.  1886,  103,  69;  Chem.  Soc.  Abet. 
1886,  60,  918).  Caustic  soda  or  potash  must 
be  used,  since  ammonia  gives  inaccurate  results. 

niosphorlc  and  Arsenic  aelds  are  monobasic 
with  methyl  orange,  and  dibasic  with  phenol- 
phthalein  (Joly,  Compt.  rend.  1882,  94,  629; 
Chem.  Soc.  Abst.  1882,  42,692).  These  acids 
can  be  most  accurately  titrated  with  barium 
hydroxide,  using  phenolphthalein  as  indicator. 
Towards  the  close  of  the  reaction,  time  must 
be  allowed  for  the  gelatinous  tribarium  phosphate 
Co  change  into  the  crystalline  dibarium  salt 
(Joly,  Compt.  rend.  1886,  102,  316;  Chem.  Soc. 
Abst.  1886,  60,  418).  Advantage  can  be  taken 
of  the  different  basicity  with  methyl  orange 
and  phenolphthalein  to  estimate  phosphoric  acid 
in  presence  of  monobasic  acids  such  as  hydro- 
chloric acid  (Joly,  Compt.  rend.  1886,  100,  66 ; 
Chem.  Soc.  Abst.  1886,  48,  348). 

(For  another  simple  and  accurate  method,  v, 
Segalle,  Zeitsch.  ansl.  Chem.  1896,  34,  33.) 

Carbonic  aeld  in  solution  is  estimated  by 
adding  excess  of  ammonia  and  calcium  chloride. 
The  liquid  is  then  boiled,  and  the  precipitated 
calcium  carbonate  collected,  well  washed,  and 
dissolved  in  a  measured  excess  of  standard  hydro- 
chloric acid,  the  excess  of  acid  being  determined 
by  means  of  standard  alkali.  The  volume  of 
normal  acid  actually  used  multiplied  by  0*022 
gives  the  quantity  of  carbon  dioxide. 

Insoluble  carbonates  are  weighed  into  a  flask 
fitted  with  a  cork  which  carries  a  bulb  and 
delivery  tube.  The  bulb  contains  moderately 
strong  hydrochloric  acid,  which   is  allowed   to 


M 


ACTDTMETRY  AND  ALKALIMETRY. 


drop  slowly  on  the  carbonate,  and  the  evolved 
gas  is  led  into  a  flask  containing  stronff  ammonia 
solution.  This  flask  is  olos^  with  a  cork, 
through  which  passes  the  delivery  tube,  which 
ends  just  above  the  surface  of  the  liquid.  The 
cork  also  carries  an  exit  tube  filled  with  glass 
beads  moistened  with  ammonia  to  arrest  the 
last  traces  of  carbon  dioxide.  When  aU  the  gas. 
has  been  enelled  from  the  carbonate  the  am- 
monia is  mixed  with  calcium  chloride,  boiled, 
and  the  precipitate  treated  as  above ;  c/.  Gooch 
and  Phelps  (Amer.  J.  Sci.  1895,  50, 101).  With 
slight  modification  this  process  can  be  adapted 
to  the  estimation  of  carbon  dioxide  in  aSrated 
waters. 

For  the  direct  titration  of  carbon  dioxide  in 
solution,  V.  Seyler  (Analyst,  1897,  22,  312) ; 
Ellms  and  Beneker  (J.  Amer.  Chem.  Soc.  1901, 
23,  405) ;  and  Forbes  and  Pratt  (J.  Amer.  Chem. 
Soc  1903,  25,  742). 

Qydroflnorte  aeld  may  be  accurately  titrated 
with  sodium  hydroxide  free  from  carbonate, 
using  phenolphthal^bi  as  indicator  (Winkler, 
Zeitsch.  angew.  Chem.  1902,  15,  33 ;  c/.  Haga 
and  Osaka,  Chem.  Soc.  Trans.  1895,  67,  251 ; 
and  J.  Amer.  Chem.  Soa  1896,  18,  415; 
Monatsh.  1897,  18,  749). 

HydrofluosOiele  add  may  be  titrated  with 
sodium  or  barium  hydroxide  in  the  presence  of 
fdcohol  (an  equal  volume  is  added)  using  phenol- 
phthalein  orlacmoid  as  indicator;  the  alcohol 
renders  the  salt  produced  insoluble  in  the  solu- 
tion; V,  Sahlbom  and  Hinrichsen  (Ber.  1906, 
39,  ^609);  c/.  Schucht  and  Moller  (Ber.  1906, 
39,  3693) ;  and  Honig  and  Szabadka  (Chem. 
Zeit.  1907,  31,  1207). 

Combined  aelds  in  salts  may  be  estimated 
with  approximate  accuracy  by  adding  to  a  solu- 
tion of  the  salt  a  measured  excess  of  sodium 
hydroxide  or  carbonate.  The  liquid  is  boiled, 
allowed  to  cool,  and  diluted  to  a  definite  volume. 
When  the  precipitate  has  settled,  an  aliquot 
portion  of  the  clear  liquid  is  withdrawn,  and  the 
excess  of  alkali  determined  by  titration.  From 
the  volume  of  alkali  used  the  proportion  of  acid 
in  the  salt  is  calculated.  In  order  to  avoid  the 
error  due  to  the  presence  of  the  precipitate,  the 
liquid  may  be  filtered  before  diluting  to  a  definite 
volume,  but  methyl  oranee  or  cochmeal  must  be 
used  as  indicator  in  order  to  avoid  any  error 
from  carbon  dioxide  absorbed  from  the  atmo- 
sphere. Salts  of  copper,  silver,  mercury,  cobalt, 
nickel,  iron,  and  chromium  are  precipitated  with 
sodium  hydroxide ;  salts  of  calcium,  barium, 
strontium,  magnesium,  aluminium,  zinc,  bismuth, 
and  manganese,  with  sodium  carbonate. 

Kiefler's  method  is  useful  for  coloured  solu- 
tions, or  in  presence  of  normal  salts  with  acid 
reactions  ( Annalen,  1855,  93,  386).  Sixty  grams 
of  crystallised  cupric  sulphate  are  dissolved  in 
water,  mixed  with  ammonia  until  the  precipitate 
is  almost  but  not  quite  dissolved,  dilute<i  to 
about  900  C.C.,  the  solution  left  for  some  time, 
and  the  clear  liquid  siphoned  off,  or  filtered 
through  glass-wool,  and  diluted  to  1000  c.c. 
If  any  further  precipitate  forms,  it  must  be 
siphoned  off  or  collected.  If  the  solution  of 
cuprammonium  sulphate  thus  obtained  is  added 
to  an  acid  liquid,  so  long  as  the  acid  is  in  excess 
an  ammonium  salt  and  cupric  sulphate  are 
formed,  but  as  soon  as  the  free  acid  is  neutralised, 
the  ammonia  in  a  fresh  quantity  of  cupram- 


J  moniam  sulphate  reacts  on  the  ouprie  lulpliale 
already  in  the  liquid  and  produces  a  precipitate 
of  a  basic  salt,  the  formation  of  which  indicates 
the  point  of  saturation.  The  precipitate  is  most 
readily  seen  against  a  black  background.  In 
order  to  standardise  the  liquid,  10  c.c.  of  normal 
sulphuric  acid  are  placed  in  a  flask  or  beaker 
and  Kieffer's  solution  added  until  a  permanent 
precipitate  is  produced,  and  £rom  the  volume 
of  solution  required,  its  strenffth  in  terms  of 
normal  acid  is  readily  calculateo.  The  strength 
of  the  solution  gradually  diminishes,  and  it  must 
be  titrated  from  time  to  time.  In  ma-lring  an 
actual  determination,  the  Kieffer's  solution  is 
added  to  the  liquid  to  be  tested  until  a  per- 
manent precipitate  is  formed.  The  methoa  is 
not  very  a<)curate,  owing  mainly  to  the  fact  that 
the  precipitate  is  not  quite  insoluble  in  solutions 
of  ammonium  salts,  and  therefore  tiie  end  re- 
action, does  not  take  place  until  the  liquid  is 
saturated  with  the  basic  salt.  The  magnitude 
of  the  error  depends  on  the  oonoentration 
of  the  solution.  When  the  liquids  to  be  ti- 
trated contain  barium,  strontium,  ftc.,  the 
Kieffer's  solution  must  be  prepaied  with  cuprio 
nitrate. 

(For  other  methods,  v.  Sims  (Chem.  News, 
1907,  95,  253)  and  Ahlum  (Chem.  Soo.  Proo. 
1906,22,63).) 

BibUoaraphp. — ^Mohr's  Chemisoh-Analytisohe 
Titrirmethode,  6th  ed.  1886;  Sutton's  Volu- 
metric AnaljTsis,  9th  ed.  1904;  Fresenius* 
Quantitative  Chemische  Analyse,  v.  2,  6th  ed. ; 
Treadwell-Hall,  Analytical  Chemistry,  v.  2,  2nd 
ed.  1910 ;  Lunce's  Technical  Chemist's  Hand- 
book ;  Ck>hn's  indicators  atfd  Test  Papers,  2nd 
ed.  1902 ;  Glaser's  Indikatoren  der  Acidimetrie 
und  Alkalimetrie,  1901.  Q.  T.  11 

ACID  ALIZARIN,  -BLACK,  -BROWMS, 
-PONCEAU,    -YELLOWS    v,   Ako-   coloubiko 

MATTERS. 

ACm  MAGENTA,  ACID  VIOLET   v.  Tri- 

phenylmethane  colourrno  matters. 

ACEDINE  brilliant  red  v.  Azo-  golour. 
ing  matters. 

ACIDOL.  Trade  name  for  betaina  hydro- 
chloride. 

ACIERAL.  An  alloy,  said  to  be  made  by 
first  melting  together  Al  76,  Ni  10,  Ag  16, 
Co  2-6,  Cu  3-6,  W  0-6,  Cd  10,  Sn  1-6,  m  an 
electric  furnace  and  stirring  tiie  fused  mass 
into  nine  times  its  weight  of  aluminium,  heated 
in  a  plumbago  crucible  Uned  with  macnesia  in 
an  ordinary  furnace  (Fr.  Pat.  473412,  1914). 
The  allov  is  silver- white,  of  sp.gr.  2*82,  and 
m.p.  750  .  Its  tensile  strength  in  castings  is 
stated  to  be  30,000,  in  rods  and  sheets  as  28,000- 
64,000,  and  heat-treated  as  70,000  lbs.  per  square 
inch.  It  may  be  cast,  forged,  drawn,  rolled, 
tempered,  electroplated,  and  soldered.  It  is 
reported  to  have  been  used  by  the  French  Govern- 
ment for  the  manufacture  of  helmets  (Eng.  and 
Min.  J.  1917,  103,  736). 

ACITRIN.  Trade  name  for  the  ethyl  ester 
of  2-phenyl-quinoline  4-carboxylic  acid.  Used 
on  account  of  its  analgesic  action  in  the  treat- 
ment of  sciatica  and  gout,  and  as  uric  add 
tliminants. 

ACME  YELLOW  v.  Azo-  colouring  matters. 

ACOCANTHERA  SCHIMPERL  The  arrow- 
poisons  of  East  Africa  are  prepared  from  the 
wood  of  the  genus  Aeocanthern,  which  contains  a 


ACONTTTNE  AND  THE   ACONITE  ALKALOIDS. 


06 


cfystaUiiie  glaooside,  aeocarUherinin  C^Q^^fin, 
H,0  (Amaud),  C„HseOit  (Faust).  (^ystJtises 
from  water  and  alcohol ;  insol.  in  ether  or  chloro- 
form ;  aoL  neatral  and  bitter.  Strong  Bnlpharic 
acid  gives  a  red  colour  eventoally  becoming 
fi;reen.  On  boiling  with  dilate  mineral  acids  is 
nydrolysed  with  formation  of  rhamnoee.  Is 
optically  inactive,  softens  at  130°  and  decom- 
poses at  220°.  The  pharmacological  action  of 
the  glacoside  resembles  that  of  membms  of  the 
digitalin  group  (Fraser  and  Tillie,  Proc.  Roy. 
Soc.  68.  70;  Faust,  Ghem.  Zentr.  1902,  2, 
[19]  1217;  c/.  Stbophanthus). 

ACOINE.  Trade  name  for  eift-p-aniBylmono- 
phenetylguanidine  hydrochloride.  Used  as  a 
local  anasthetio. 

AOONITINE  AND  THE  ACONITE  ALKA- 
LOIDS. The  alkaloids  of  the  various  species  of 
Aconiium  which  have  been  examined  chemically, 
fall  into  sharply  differentiated  groups.  The 
first,  of  which  aconitine  itself  is  the  type,  includes 
a  number  of  highly  toxic  alkedoids  {the  aconi- 
Hnes),  which  are  diacyl  esters  of  a  series  of 
polyhydroxy  bases  containing  four  mothoxyl 
groups  {the  aeonines).  The  following  'aconi- 
tinee '  are  known  : — 

Aoonitine  from  Aconitvm  Napellus  (Linn.), 

^tibAaoonitine  from  Aconiium  spicatum 
(Stapf.), 

/lufaconitine  from  Aconitum  chanaanihum 
(Stapf.), 

Jopaconitine  from  Japanese  aconite  roots, 

P^ieiftf aconitine  from  Aconiium  deinorrhizum. 

The  alkaloids  of  A,  Vulparia  {=A.  Lycoclo- 
num)  and  A.  sepienirionaU  constitute  a  second 
group  of  toxic  alkaloids  derived  from  aconites, 
while  there  is  a  third  {(roup  which  contains 
non-toxic  alkaloids  typified  by  atisine  and 
comprises  the  following  : — 

Atisine  from  Aconitum  heierophyUum  (Wall.), 

Po^atiaine  from  Aconitum  jKumcUum 
(D.  Don.). 

Af  onliine  is  the  principal  alkaloid  of  Aconiium 
NapeUua  (Linn.),  the  common  monkshood  or 
wolfsbane  {Coqueluckon,  Fr. ;  Eismhui,  Skirm- 
k!ut,  Ger.),  in  which  it  occurs  along  with  its 
decomposition  products,  benzaconine  and  aco- 
nine.  Aconiii  radix,  B.P.,  is  the  fuU-^rown 
daughter  root  only.  Aconiium,  U.S.P.,  is  the 
root  containing  at  least  0*6  p.c.  of  aconitine. 
Aconiiina,  B.P.,  U.S.P.,  is  the  alkaloid.  Aconi- 
tine was  isolated  by  Geiger  and  Hesse  (Annalen, 
1833,  7,  276),  but  first  obtained  in  a  crystalline 
state  by  Groves  (Pharm.  J.  1860,  [ii.]  8,  121). 
Wright  and  Luff  assigned  to  it  the  formula 
CmH4,0„N  (Ghem  Soc.  Trans.  1877,  31,  143 ; 
1878,  33,  161,  318),  and  later  Dunstan  and  his 
oollaboratora  {ibid.  1891,  69,  271;  1892,  61, 
386)  adopted  for  it  the  formula  0mH4bOi,N, 
a  slight  modification  of  that  used  by  Wright 
and  Luff  (/.c).  Until  now  almost  all  the  work 
on  crjnstallised  aconitine  had  been  done  on 
alkaloid  prepared  from  the  roots  of  Aconitum 
NapeUus  grown  in  England.  In  1894  analyses 
of  the  crystallised  aconitine  of  commerce, 
probably  from  roots  of  Aconiium  NapeUus  grown 
in  Germany,  were  made  bv  Frennd  and  Beck, 
who  assigned  to  the  alxaloid  the  formula 
0MH«70nN  (Ber.  1894,  27,  433),  and  their 
resulte  were  confirmed  by  Schulze  (Arch. 
Pharm.  1906,  244,  167),  who  preferred  the 
formula  Ct4H440xiN.    This  latter  formula  has 

Vol.  L— 2\ 


been  accepted  by  Dunstan  and  Henry  (Trans. 
Ghem.  Soc.  1906,  87,  1660)  as  lepreeenting  the 
composition  of  the  present  day  aconitine  of 
commerce.  The  earlier  formula  with  less 
carbon  are  either  due  to  botanical  differences 
(the  English  root  is  now  difficult  to  obtain)  or 
to  the  escape  of  methane  in  the  combustions. 

Preparation,  The  finely-powdered  root  is 
exhausted  with  amyl  alcohol  mixed  with  three 
times  its  volume  of  wood  spirit.  From  this 
extract  the  wood  spirit  is  distilled  under  reduced 
pressure,  leaving  the  whole  of  the  alkaloids 
dissolved  in  the  residue  of  amyl  alcohol  from 
which  they  are  removed  by  agitation  with 
dilute  (1  p.c.)  sulphuric  acid.  This  acid  aqueous 
liquid  is  shaken  with  ether  to  remove  ether- 
soluble,  non-basic  substances,  then  made  alka- 
line with  dilute  ammonia  and  the  liberated 
alkaloids  extracted  with  ether.  The  aconine 
remains  dissolved  in  the  water,  the  aconitine 
with  some  benzaconine  passing  into  the  ether. 
The  ethereal  solution  is  washed  with  a  small 
quantity  of  water  and  evaporated.  The  residue 
is  converted  into  hydrobromide  by  dissolving 
it  in  dilute  hydrobromio  acid,  care  being  taken 
to  avoid  excess  of  acid.  The  exaotiy  neutral 
liauid  is  evaporated  to  a  small  volume  and 
allowed  to  crystallise.  The  aconitine  hydro- 
bromide  is  recrystallised  until  of  constant 
melting-point,  and  then  is  converted  into  the 
alkaloid  by  the  addition  of  a  slight  excess  of 
ammonia  to  its  aqueous  solution,  the  alkaloid 
being  extracted  by  ether  in  the  usual  way.  The 
washed  ethereal  solution  is  dried  by  agitation 
with  fused  calcium  chloride  and  evapoHted. 
The  small  crystals,  which  are  deposited  as  the 
ether  evaporates,  may  be  recrystallised  from 
dry  alcohol  by  the  addition  of  ether. 

Properties.   Colourless,  anhydrous  hexagonal 

grisms,  belonging  to  the  rhombic  system  ((3iem. 
oc.  Trans.  1891,  69,  288 ;  Ber.  1894,  27,  722 ; 
Arch.  Pharm.  1906,  244,  169).  Easily  soluble 
in  chloroform  or  benzene,  less  readilv  in  absolute 
alcohol  or  ether,  very  sli^htiy  soluble  in  water, 
almost  insoluble  in  light  petroleum.  The 
aqueous  solution  is  alkaBne  .to  litmus;  m.p. 
196°-197'*.  Dextrorotatory  ;  in  alcoholic  solu- 
tion [alD=  + 12°  32'.    Salts  lievorotatory. 

Aconitine  is  a  most  powerful  poison  (Cash  and 
Dunstan,  Phil.  Trans.  1898,  190,  239).  Between 
Aj  and  ^  of  a  grain  has  been  recorded  as  a  fatal 
human  aoae. 

The  ordinary  salts  of  aconitine  crystallise 
well.  The  hydrobromide  B*HBr,2|H,0  is  levo- 
rotatory,  [alD= -30-47° ;  m.p.  163**  or  206* 
(anhydrous).  The  hydriodide,  m.p.  226^  Is 
crystalline,  and  sparingly  soluble  in  water.  The 
aurichloride  B'HAuCl4  is  thrown  down  as  a 
pale-yellow  amorphous  precipitate  from  solu- 
tions of  the  hydrochloriae  and  auric  chloride. 
It  crystallises  from  alcohol  with  3H,0  and  then 
melts  at  136*6° ;  the  anhydrous  salt  has  m.p. 
162°  (Freund,  Ber.  1894,  27,  724). 

Reaciiona.  When  aconitine  is  heated  at  its 
melting-point  it  loses  1  mol.  of  acetic  acid  and 
furnishes  a  new  alkaloid  pyraconiiine,  and  this, 
on  hydrolj^sis  with  water  or  acids,  furnishes 
1  mol.  of  benzoic  acid  and  a  new  base  pyraconine. 

When  a  salt  of  aconitine  is  heated  with 
water,  a  molecule  of  acetic  acid  is  split  off  and 
the  alkaloid  henzaconine,  which  also  occurs  in 


66 


AOONiriNE  AND  THE   ACONITE  ALKALOIDS. 


aoonite  roots,  and  has  been  varioualy  known  aa 
picraeomtine,  iaaconitine^  napelline,  fta,  is 
formed.  Benzaconine,  in  turn,  by  hydrolysia 
with  alkalia  or  aoida,  f  umiBhee  1  moL  oi  benzoio 
aoid,  and  the  alkaloid  aeonine,  which  is  the 
final  basic  product  of  the  hydrolysis.  Aconitine 
is  theirefore  aceiyJbenxoylaconine, 

On  treatment  with  acetyl  chloride  aconitine 
furnishes  a  tziacetvl  derivative  (m.^.  207^-208®). 
When  heated  with  hvdriodic  add  it  yields  four 
mols.  of  methvl  iodide,  and  must  therefore  con- 
tain four  metnoxyl  groups.  It  also  contains  a 
methyl  group  linked  to  nitrogen.  On  oxidation 
with  acid  permanganate  aoomtine  yields  aoetal- 
dehyde  and  a  neutral  crystalline  substance 
oxtmUine  (Cazr,  Ghem.  Soc.  Trans.  1912,  101, 
3241).  This  substance  was  also  obtained  by 
Brady  (Ghem.  Soa  Trans.  1913,  103,  1821),  and 
iB  most  readily  prepared  by  oxidation  with 
permanganate  m  acetone  solution  (Barger  and 
Field,  Chem.  Soc.  Trans.  1915,  107,  231).  The 
formula  is  most  likely  Cs4H,»0»N,  m.p.  276'- 
277''  (bath  previously  heated  to  260'').  Further 
oxidation  with  nitric  acid  yields  a  nitroso- 
dioarboxylic  acid  CMHa«,Oi,Nt,  m.p.  206^* 
(Brady).  Oxonitine  is  also  formed  by  the 
oxidation  of  japaconitine  and  deserves  further 
investigation. 

It  IS  probable  from  the  foregoing  summary 
of  the  chief  reactions  of  aconitine  that  it  may  be 
regarded  as  derived  from  a  parent  base  Ca«H,iN. 

BzO-^^  w**"^**®  ^(0Me)4 
Aoonltlne. 

Detection  and  etiim(Uian.—T\M  identification 
of  the  alkaloid  is  best  accomplished  by  the 
determination  of  the  physical  constants  of  its 
characteristic  derivatives,  but  where  minute 
quantities  only  are  available  the  characteristic 
precipitate  given  with  potassium  permanganate 
(Dunstan  and  Carr,  Pharm.  J.  1896,  [iv.]  2, 122), 
and  the  peculiar  tingUng  sensation  produced 
when  even  very  dilute  (1  in  4000)  solutions  of 
aconitine  are  applied  to  the  tip  of  the  tongue 
mav  be  utilised,  but  these  reactions  are  equally 
applicable  to  the  '  aconitines '  as  a  class.  Various 
methods  for  the  estimation  of  aconitine  in  aconite 
roots  have  been  proposed,  but,  as  a  rule,  these  esti- 
mate some  benzaoonine  and  aoonine  as  well  as 
aconitine,  and  are  useless  as  methods  of  deter- 
mining the  medicinal  value  of  the  roots,  since  this 
depends  essentially  on  the  amount  of  aconitine 


piesent.  Aconitine  itself  may  be  estimated  by 
hydiolysing  it  and  determining  the  amount  of 
acetic  acid  formed,  but  this  method  cannot  be 
used  for  the  estimation  of  aconitine  in  the  plant 
since  the  latter  contains  other  substances  which 
yield  acetic  acid  (DunsUn  and  Tickle,  Pharm. 
J.  1896,  [iv.l  2,  126). 

BenzaeoDine  CaaH^^OioN  has  also  been 
called  ieacanitine,  picracanttine,  and  napeUine 
by  various  observers.  It  occurs  with  aconitine 
in  aconite  roots,  and  mav  be  isolated  from  the 
mother  liquors  from  which  aconitine  hydro- 
bromide  has  been  crystallised,  and  is  also  pro- 
duced by  heating  an  aqueous  solution  ot  an 
aconitine  salt  in  a  closed  tube. 

Properties,  Amorphous,  dextrorotatory  base 
furnishing  crystalline,  Invorotatory  salts.  The 
hydrobromide  crystallises  in  prisms,  m.p.  273' 
(Schulze,  Ix,) ;  the  hydrochloride  occurs  in  two 
forms,  m.p.  217*  and  268'  (Freund  and  Beck, 


Ber.  1894, 27, 729) ;  the  hydriodide  has  m.p  204'- 
206'.  The  aurichloride  has  m.p.  136'.  Accord- 
ing to  Schulze  (Le,)  the  tetracetyl  derivative  of 
benzaconine  is  identical  with  triacetyUoonitine. 

With  the  removal  of  the  acetyl  group  from 
aconitine  the  characteristic  toxicity  disappears 
and  benzaconine  is  not  toxic  in  the  ordmary 
sense.  In  some  respects  its  physiological  action 
is  antagonistic  to  that  of  aconitine  (Gash  and 
Dunstan,  PhiL  Trans.  1898,  190,  239). 

Aeonine  G.^HmO^N,  the  ultimate  basic 
product  of  the  hydrolysis  of  aconitine  or  benza- 
conine is  amorphous  and  dextrorotatory,  but 
yields  hygroscopic  Ittvorotatory  salts.  It  is 
readily  soluble  in  water,  alcohol,  or  chloroform, 
but  almost  insoluble  in  ether  or  light  petroleum. 
The  hydrochloride  B-Ha,2H,0  has  m.p.  175'- 
176',  and  the  hydrobromide  B-HBr,liUaO, 
m.p.  226'.  The  aurichloride  is  amorphous. 
The  base  furnishes  a  crystalline  tetracetyl  deriva- 
tive, m.p.  231'-232'  (Schulze,  le.  1906,  244, 
177).  On  oxidation  with  permanganate  it  fur- 
nishes acetaldehyde  and  an  amorphous  base, 
but  with  chromic  acid  it  yields  methylamine  and 
two  new  bases  (0H)4G,^H.,0(0Me),NMe  and 
Oi«H,oO.(OMe),(NMe)GO.H,  the  former  an 
amino  alcohol  and  the  latter  an  amino  add 
(Schulze,  Arch.  Pharm.  1908,  246,  281 ;  cf.  (3arr, 
Proc.  Chem.  Soc.  1912, 28, 253 ;  Brady,t5tV2.  p.  289). 

Blkhaconltlne  G,,H,|OiiN.  The  character- 
istic alkaloid  of  Aconitum  epicatum  (Stapf.),  the 
roots  of  which  constitute  *  bikb  '-aconite  of 
North  Western  India.  It  may  be  extracted 
from  the  roots  by  a  slight  modification  of  the 
process  described  under  aconitine.  The  alka- 
loid was  isolated  and  characterised  by  Dunstan 
and  AndrowB  (Ghem.  Soc.  Trans.  1905,  87, 1636). 

Properties,  Separates  from  ether  in  button- 
shaped  masses,  m.p.  118'-123',  or  from  alcohol 
on  addition  of  water  in  white  granules  con- 
Uining  1H,0,  m.p.  113'-116'.     Dextrorotatory 

([al^—-f  12-21'    in    alcohol).  'The    salts  aro 

Isevorotatory.  The  hydrochloride  B-HG1,6H,0, 
m.p.  159'-161'  (anhydrous),  crystallises  and  has 
[alp— 8*86'    (in    water);     the    hydrobromide 

BHBr,5H,0,  m.p.  173'-175'  (anhydrous)  is 
crystalline  and  has  [a]  p— 12*42'  ;  the  hydriodide 

B*HI,2iH,0,  m.p.  193'-194'  (anhydrous),  orys- 
tAllises  in  needles,  and  is  sparingly  soluble  in 
water;  the  aurichloride  B-HAuCl^  orystallises 
in  canary-yeUow  needles,  m.p.  232'-233'.  Like 
all  the  *  aconitines  '  bikhaoonitine  is  highly  tozio. 
Beaetions.  Bikhaoonitine  contains  six  meth- 
oxyl  groups.  When  heated  at  180'  it  loses  I 
moL  of  acetic  acid  and  forms  pyrobikhaconitine 
(amorphous,  giving  amorphous  siaJts).  It  under 
goes  hydrolysis  in  two  stages,  thus — 

i.  C„H„0„N-|-H,0=C,,HoO,.N+C,H40, 
Bikhaoonitine.   Veratroylbikhaconine.  Acetic  add. 

ii.  C,4H„0„N+H,0=C„H«0,N+C,Hio04 
VeratroylblkhaconiDS.    Biimaconlne.  Veratric  add. 

Bikhaoonitine,  thereforo,  resembles  pseudaooni* 

tine  {see  p.  634)  in  furnishing  veratric  acid  in 

I  the  second  stage  of  its  hydrolysis.    The  alkaloid 

is,   thereforo,   acetylveratroylbikhaconine,   and 

may  be  ropresented  thus — 

[MeO].C„H,,ON<g^ 

Veratioylblkhaeoiiine  Ga«H«,Oi.N,  the  first 
basic  hydrolytic  product  of  bikhaoonitine, 
is  amorphous  and  aextrorotatory  ([a]p=  +29-9' 

in   alcohol).    The    hydrochloride   and    hydro- 


ACONITINE  AND  THE   ACONTTB  ALKALOIDS. 


67 


bromide  mn  unorphoua,  but  th«  hydiiodide 
etyitollifles  in  loaettee  of  needles,  m.p.  189*-190^. 
The  nitrate  forms  rosettes  of  hexBflonal  pnsms, 
in.p.  178*-^78^.  ^e  anziohloride  forms  oiange- 
yeUow  rosettes  of  prismatic  orystals,  m.p.  14ff*- 
148''  (anhydrons). 

BiKBAOOimni  Cifi^^OyV,  the  final  basie 
piodaot  of  the  hydliolysis  of  bikhaoonitine  or 
▼eratroylbikhaoonine.  It  is  dextrorotatory  and 
amorphous,  bat  nnlike  the  '  aconines  '  as  a  class, 
fomiuies  well-defined  erystalline  salts.  The 
hydrochloride  ooours  in  rosettes  of  crystals, 
m.p.  I25*~180*,  the  hydiobiomide  in  tetragonal 
prisms,  m.p.  146*-160°,  and  the  anriohloride 

B-HAna«,3H,0 
in  g&tening  rhombic  plates,  m.p.   129M82* 
(hydrated),  or  IST'-ISS*  (anhydrous). 

IndaemilttiM  Gt4H4,0ieN  is  the  oharacteristio 
alkaloid  of  Acanitum  ehamunUhum  (Stanf.),  a 
species  indiffenons  to  India,  where  it  is  imown 
as  'Ifiohri.'  It  may  be  extracted  from  the 
roots  by  the  process  described  under  aconitine. 
The  allcaloid  was  isolated  and  characterised  by 
Dnnstan  and  Andrews  (Ghem.  Boo.  Trsns.  190^ 
87, 1620). 

Properlus.  Indaconltine  crystalliBes  in 
seTSfal  charaoteristio  forms,  but  can  be  obtained 
in  crystals,  which  aro  almost  identical  in  form 
with  those  of  aconitme  (see  above).  It  has  m.p. 
802*'-203^and  is  dextroroUtory  [a]jj—+18*»  17'. 

The  salts  crystallise  well  and  aro  l»Torotatory. 
The  hydrochloride  B*HCI,3H,0,  m.p.  166M71'' 
(anhydrous),  [a]^a— 15^  60',  forms  rosettes  of 

mSky  needles;  the  hydrobromide,  m.p.  183*- 
187*(anhydroiis),  [a]^^— 17*16',  crystallisesfrom 

water  in  larse  hexaeonal  prisms ;  the  anri- 
ohloride B-HAna«,Glfa„  m.p.  147M52*,  forms 
rosettes  of  needles  from  chloroform  by  addition 
of  ether. 

Indaoonitine  gives  a  characteristic  crystalline 
pteoipitata  with  potassinm  permanganate,  the 
crystals  being  smaller  and  less  stable  than  those 
^ven  bv  aconitine.  Like  acdhitine,  indaconitine 
18  higher  toxic  (Ossh  and  Dunstsn,  Proc.  Boy. 
Soo.  1905,  B,  76, 468). 

Beadtcm, — ^Indaoonitine  contains  four  meth- 
oxyl  gronpB.  On  hydrolysis  it  behaves  m  a 
manner  analogous  to  aconitine,  yielding  in  the 
first  stage  acetic  acid  and  indbenzaconine,  the 
latter,  on  further  hydrolysis,  fumishhig  bensoio 
add  and  psendaconine.  Hie  latter  is  also  the 
final  basic  hydrolytio  prodnot  of  pseadaoonitine 
(p.  634),  so  that  pseudaconitine  differs  only 
from  indaoonitine  m  containing  a  veratroyl 
poop  in  place  of  a  benzoyl  group.  Indaconitine 
m  ihereforo  acetylbenzoyipseudaconine,  and  may 
be  ropresented  thus — 

[MeO]4C„H„OJI<g^° 

IndbcniMOiilne  (Benzoylpsendaconine) 

C„H,.0,N 

tlie  first  basio  product  of  the  hydrolysis  of 
indaoonitine  is  amorphous  and  dextrorotatory, 
[a1^-B+33*  35',  but  furnishes  well  crystallised, 

Isvorotatory  salts.    The  hydrobromide 

B-HBr,2HaO, 
m.p.  247*  (anhydrous)  forms  rosettes,  the 
hydrochk>ride  B«HC3,  m.p.  242*-244*,  octa- 
hedra,  and  the  aurichbride,  m.p.  180M82*, 
orange  rosettes.  The  aurichloro  derivative,  m.p. 
234*-285*«   forms   minute   colourless   crystals. 


I  On  hydrolysis  with  alkalis  indbenzaoonine 
furnishes  bensoio  add  and  psendaconine  (ms 
p.  634).  As  ii  the  case  with  aconitine  the 
romoval  of  the  acetyl  ^up  virtually  abolishes 
the  toxicity  of  indaoonitine  and  indbenzaconine 
is  scarcely  poisonous  in  the  ordinary  sense 
(Ossh  and  Dunstan,  Lc), 

PyrolndAeonltine  C,,H4,0|N  exists  in  two 
forms.  The  a-  form  is  prodnced  when  tbe  free 
base,  indaoonitine,  is  heated  at  its  meltins- 
point.  It  is  amorphous,  but  furnishes  a  crystM- 
Une  hydrobromide  B-HBr,  in.p.  104M08^ 
^diich,  like  the  alkaloid  itself,  is  dextrorotatory. 
The  aurichloride  is  amorphous.  When  indaooni- 
tine hydrochloride  is  heated  at  its  melting-point 
it  furnishes  ^-pyroindaconitine,  ^^ch  is  also 
amorphous,  but  yields  a  crystalline  hydro- 
bromide, m.p.  248^-250^ 

Japaoonltin6C,4H4,Oi^Nis  the  characteristic 
alkaloid  of  Japanese  aconite  roots  of  commerce. 
It  may  be  prepared  from  this  source  by  the 
method  described  under  aconitine.  Accordins  to 
Makoshi  the  roots  of  true  AeonUum  Fiscneri 
(Reichb.)  contain  jesaconitine  {tee  below),  whilst 
japaconitine  is  furmshed  hy  the  roots  of  a  variety 
grown  in  Hondo  (Aroh.  Iharm.  1909,  247>270), 
which  Holmes  regards  as  A.  unoinatump  var. 
ja/ponicwn.  Japaconitine  has  been  froquently 
investigated,  and  up  to  1900  the  balance  of 
evidence  was  in  favour  of  the  view  that  it  Was 
identical  with  aconitine  (Mandeljn,  Aroh.  Pharm. 
1885,  223,  97,  129,  161;  Lflbbe,-Inaug.  Diss. 
Dorp.  1891 ;  and  Freund  and  Beck,  Ber.  1894, 27, 
720.  The  non-identity  of  the  two  alkaloids  had 
already  been  asserted  by  Wright  and  Luff  (Chem. 
Soc  Trans.  1879, 35, 387),  and  was  finally  proved 
by  Dunstan  and  Read  {ibid.  1900, 77, 45).  Their 
eondusions  have  leea  confirmed  by  Makoshi  ({.c). 

Properties.  Forms  rosettes  of  prismatic 
needles,  m.p.  204*2^  and  is  crystallosraphically 
distinct    from    aconitine    and    pseudaconitine. 

DextroroUtory  ([a]^®'^-» +23*6'*  in  alcohol),  but 

furnishes  Isvorotatory  salts.    The  hydrochloride 
BHa,3H,0,  m.p.  149M50*,  [a^^— 23-8»  in 

waterp  ervstallises  from  alcohol  and  ether  in 
rosettes  of  hexagonal  plates ;  the  hydrobromide 
B*HBr,4H,0,  m.p.  172M73^  orystoUises  simi- 
larly ;  the  aurichloride  exists  in  two  modifica- 
tions, the  OF  form,  m«p.  231*  is  stable  and 
crystallises  in  opaque,  golden-vellow  needles; 
the  fi-  form,  m.p.  154^-160°,  is  unstable  and 
crystallises  in  yellow  prisms.  The  physiological 
"^aotion  of  japaconitine  is  qualitativdy  identical 
with  that  of  aconitine  than  which  it  is  slightly 
moro  toxic  (Oash  and  Dunstan,  Aroc.  Roy.  Soo. 
1902,  68,  379). 

Beadiaru,  Japaconitine,  unlike  aconitine, 
reacts  with  methyl  iodide  to  form  a  crystalline 
methiodide,  and  from  this  methyljapaconitine 
Ga4H4,0iiN-CH„  m.p.  206'',  rosettes  of  colourless 
needles  may  be  obtained.  Japaconitine  forms  a 
crystalline  triacetyl  derivative,  m.p.  166*,  and 
contains  four  methoxyl  groups.  When  heated 
alone  it  furnishes  1  mol.  acetic  acid  and  1  mol. 
pyrojapaconitine  (v.  infra).  On  hydrolysis  it 
also  behaves  in  a  manner  analogous  to 
aconitine,  giving  first  1  mol.  each  of  acetic  acid 
and  japbenzaoonine.  The  latter  may  be  further 
hydrolysed  to  benzoic  acid  and  japaconine. 
Japaconitine  is  thereforo  acetylbenzoyljapaco- 
nine,  and  may  be  represented  tbus  (D.  a.  R.) — 


I' 


S=^j.>C„H  .NH<8^ 


63 


ACONiriNE  AND  THE  ACONITE  ALEAI/>ID& 


Japbensaeonlne  C^H^.O^oN,  the  first  htsic 
hydiolytic  product  of  japaoonitine,  abo  occurs 
with  this  alkaloid  in  Japanese  aconite  roots. 
Unlike  the  aaalosous  bwsaoonine,itGry8talli8es» 
though  with  difficulty,  m.p.  183^  Deztroio- 
totory  ([o]j^-= +40-16^  in  alcohol).    The  salts 

crystallise  well,  and  sue  Icevorotatory ;  the 
hydrochloride  B-HCa,H,0,  m.p.  253°,  forms 
minute  rosettes;  the  aurichloride  B-HAuGIa 
crystallises  from  alcohol  and  then  melts  at  219**. 
The  colourless  auriohloro  derivative 

C,|H4,OioNAua„ 
m.p.  178^  forms  rosettes  of  needles  (D.  a.  R.  {.c). 

JapaeoDine  C,,H4,0^,  the  final  basic  pro- 
duct of  the  hydrolysis  of  japaoonite  or  jap> 
benzaoonine,  is  amorphous,  and  hygroscopic  and 
yields  hygroscopic  salts,  which  crystallise  with 
difficulty.  Its  solutions  reduce  gold  chloride  and 
Fehling's  solution.  The  base  is  dextrorotatory 
(D.  a.  B.  J.C.). 

JPyroJapaeonttlne  GgtH^gO.N  is  formed  by 
heating  japaoonite  at  its  mdting-point,  when 

1  moL  of  aoetic  acid  is  evolved.  Crystallises 
in  colourleas  needles,  m.p.  167°-168%  is  Uevoro- 
tatory  ([a]^»— 65*89°  in  alcohol),  and  fomiBhes 

well-crystadUised  salts ;  the  aurichloiide 

B*HAua4, 

m.p.  10O°-16I°  (from  chloroform),  or  188M89* 
(^m  alcohol  and  ether).  On  hydrolysis  by 
alkalis  the  base  gives  rise  to  1  mol.  bensoic  acid 
and  a  new  base  pyrojapacorUne,  which  is  amor- 
phous, hygroscopic,  and  Iievorotatory,  and 
furnishes  amorphous  salts. 

Accordiiu;  to  Scholsa  and  Liebner  (Arch. 
Pharm.  1913,  251,  453 ;  1916,  254,  567),  pyro- 
japaconitine  C^fi^S)^,  m.p.  171°,  and  pyro- 
japaconine  are  identical  with  pyraconitine 
and  pyraconine  respectively.  As  aconitine  and 
japaconitine  both  give  oxonitine  (g.v.)  on  oxida- 
tion, these  two  alkaloids  must  be  closely  related. 

Jesaeonftliie  C4oHeiO  ^  ,N,  isolated  by  Makoshi* 
(Arch.  Pharm.  1909,  247,  251)  from  '  Bushi ' 
roots  obtained  from  a  species  of  aconite,  A. 
Fischeri  (7),  found  in  the  island  of  Hokkaido  or 
Jeso  in  Japan.  It  was  not  obtained  crystalline, 
but  a  crystalline  triacetyl  derivative,  m.p.  213°, 
was  prepared.  On  hydrolysis  jesaoonitinevielded 
benzoic  acid,  anisic  add,  and  aconine,  icWtical 
with  that  obtained  from  aconitine,  so  that  it  is 
regarded  as  benzoylanisoylaconine.  Jesaconi- 
tine  is  highly  toxic  /Makoshi,  i.c.). 

Lappaconltine  CtiH^^OaNt,  obtained  by. 
Bosendahl  (J.  Pharm.  Chim.  1896,  [vi]  i,  2^) 
from  the  roots  of  AconUwm  SQi(eiilrKmale(Koelle). 
It  crystallises  in  hexagonal  prisms,  m.p.  205°,  is 
dextrorotatory,  shows  a  reddish-violet  fluores- 
oenoe  in  ether,  and  furnishes  crystalline  salts. 
On  hydrolysis  it  yields  two  bases ;  one,  m.p.  98°, 
readily  soluble,  and  the  other,  nup.  106°,  nearly 
insoluble  in  eUier;  at  the  same  time  an  acid, 
m.p.  114°,  giving  a  purple  colour  wiUi  ferric 
chloride,  is  produced.  Lappaconltine  is  highly 
toxic.  The  roots  also  contain  eynccionint 
^si^isOiaN.  (amorphous,  bitter,  and  much  less 
toxic  than  lappaoonitine)  and  ujpUrUrioinaline 
^•iH4iO«Ni,  amorphous,  bitter,  and  about 
equal  in  toxicity  to  cynoctonine  (c/.  Orloff, 
P.  Z.  f.  B.  1907,  36,  213). 

IjrcaeonlttDi  OtJB.^fij.^^  obtained  by 
Dragendorff  and  Spohn  (P.  Z.  f.  B.  1884,  23, 


313)  and  later  by  Srhulze  and  Bierling  (Arch. 
Pharm.  1913,  261,  8)  along  with  mffofOcfniM 
(C,«H4tOioN|)  and  an  unnamed  base,  from  the 
roots  of  AconUium  Lyeoctonvm  (Idnn.),  is  amor- 
phous and  dextrorotatory.  On  hydrolysis  with 
acids  it  furnishes  anthruioyl-lycoctonine  (Dra- 
gendorfE*s  lycaconine)  and  succinic  add.  On 
hydrolysis  with  sodium  hydroxide  lycoctonine 
Of  BH|,07N,H20and  lycoctoninic  add  Cfi  iH|  ^0  ^^ 
both  crystalline,  sre  formed.  Lycoctonine  luid 
been  found  previously  by  Hiibsohmann  in  the 
roots  (J.  1857,  416  ;  1866,  483  ;  c/.  Wright  and 
Luff,  Pharm.  J.  1878-9,  [iii.]  8,  169).  All  the 
alkaloids  described  are  heart  poisons. 

Psettdaeonttlne  CmH,|Oi,N.  The  character- 
istic alkaloid  of  Aconitum  deinorrhizum,  the  roots 
of  which  form  Nepaul  aconite  of  commerce.  It 
may  be  extracted  from  the  roots  by  the  process 
described  under  aconitine.  Pseudaconitme  has 
been  frequently  examined  (Wright  and  Luff, 
Chem.  Soc  Trans.  1878,  33,  151;  Mandelin, 
Arch.  Pharm.  1884,  222,  97, 129, 161),  and  most 
recently  by  Dunstan  and  Oarr  (CSiem.  Soc.  Proc. 
1895, 154 ;  and  Chem.  Soc.  Trans.  1897, 71, 350). 

Properties.  Colourless  crystals  of  rhomboidal 
shape, m.p.211°-212°(decomp.);  [aljj=+18°36' 

in  alcohoL  Beadily  soluble  in  alcohol,  less  so 
in  ether,  very  slighuy  in  water,  almost  insohiUe 
in  light  petroleum.  The  salts  are  Invorotatory ; 
the  hydrobromide  B'HBr,2H|0,  nup.  191* 
(anhydrous),  and  the  nitrate  B*HNOs,3HaO, 
m.p.  192°,  are  crystalline.  The  hydrochloride 
iB  amorphous,  but  the  aurichloride,  m.p.  236°- 
236°,  may  be  crystallised  from  alcohoL  Ptoud- 
aconitine  exerts  a  physiological  action  similar  to 
that  of  aconitine,  but  is  much  more  toxic  (Ouh 
and  Dunstan,  PMc.  Boy.  Soc.  1902,  68,  379). 

BeacHona,  On  heating  an  aqueous  solution 
of  a  neutral  pseudaconitine  salt  in  a  dosed  tube 
at  135°  the  alkaloid  underffoes  hydrolysis, 
yielding^  moL  acetic  add  and  1  mol,  veratroyl- 
pseudaoonine.  The  latter  is  hydrolysed  in  toe 
cold  by  sodium  hydroxide  in  alcohol,  furnishing 
1  moL  of  veratric  add  and  1  moL  of  pseudaconine. 
When  heated  at  its  melting-point  pseudaconitine 
loses  1  moL  acetic  add  and  furnishes  pyropsemd- 
aconitine.  Ptoudaconitme,  in  view  of  these 
reactions,  is  to  be  regarded  as  acetylveratroyl- 
pseudaconine 

fMeO].C„H„O.N<g^ 

No  relationship  has  yet  been  traced  between 
pseudaconine  and  aconine  (D.  s^  C  ;  c/.  Freund 
and  Niederhofhdm,  Ber.  1896,  29,  6,  852). 

Vmtroylpsettdaoonlna  0mH^,0hN.  The 
nrst  basic  product  of  the  hydrolysis  of  pseud- 
aconitine  {see  above)  separates  in  Urge,  irregu- 
larly-shaped crystab  fiom  ether,  m.p.  199°, 
readily  soluble  in  chloroform  or  alcohot  neariy 
insoluble  in  water  or  light  petroleum,  [a]  » 

—88°  18'  in  alcohoL  The  salts  crysUUise  well ; 
the  hydrobromide  B*HBr,3H,0  in  prisms ;  the 
nitrate  B'HNO,  in  rosettes  of  riiombic  prisms, 
m.p.  222°  and  232° ;  the  aurichloride  B-HAuaf 
is  amorphous  (D.  a.  C).  Veratroylpseudaoonine 
is  not  toxic  (Cosh  and  Dunstan,  /.c). 

Pseodaeonina  C,.H^ObN,  the  ultimate 
basic  product  of  the  hydrolysis  of  pseadaconi- 
tine  and  indaoonitine,  forms  large  colourless 
crystals,  m.p.  94°-95°,  containing  1  moL  alcohol 


ACRIBINE. 


of  ciyuniiiataan.  Dextion)totory(Wj^=38*  12* 
in  nater).    The  salts  aze  amorphoaa. 

r|l«pOTMl>WWi*lM   C,«H4T0t»N.      Formed 
by  heating  peadacoDitine  at  ita  melting-point, 
when  1  moL  acetic  acid  is  evolved ;  it  is  amor-  > 
phoQS,  but  yields  a  hydriodide,  ciyBtaUising  in 
pnsms  (D.  a.  CL  Lc), 

Atlsilie  0,sH,iOgN,  the  characteristic  alka- 
loid otAcaiUimnheieiiphyUum  (Wall.)of  Northern 
India.  It  was  fiist  isolated  by  Bronghton  in 
1873,  and  was  snbeeqnently  examined  by  Waso- 
wics  (Arch.  Fharm.  1879,  214.  103),  Wright 
(Tear  Book  Pharm.  1879,  422),*  and  later  by 
Jowvtt  (Chem.  Soc.  Trans.  1896,  69,  1618). 
Atisine  is  amorphous,  readily  soluble  in  water, 
alcohol,    ether,    or    chloroform,    Isvorotatory 

([olj**— 19-6*  in  ak»hol).  It  yields  crystal- 
line,  dextrorotatory  salts  ;  B-HCl,  prisms,  m.p. 
296*  (deoomp.) ;  B-HI,  tablets,  m.p.  279'*-281* 
(decomp.);  B,-H,PtC!g,  crystalline  yellow 
powder,  m.p.  229"  (decomp.).  When  heated  with 
water  in  a  closed  tubeatisiae  funushes  mhydraie 
G,,H„0|N,  which  is  amorphous,and  yields  amor- 
phons  siuts.    Atisine  is  non-toxic  ( Jowett,  I.e.), 

Pftlmatisbie.  A  colourless,  crystalline,  non- 
toxic alkaloid,  m.p.  285^  found  in  the  roots  of 
Aconiium  palmatum  (B.  Don.),  a  species  indi- 
genous to  India  (Dunstan  and  Carr). 

The  fullest  account  of  the  aconite  alkaloids 
is  by  F.  H.  Carr,  in  Allen's  Commercial  Organic 
Analyaia,  vol.  vi.  1912,  pp.  263-287.        G.  B. 

ACORN  OIL.  Although  acorn  oil  has  not 
yet  become  a  commercial  article,  the  yield^  of 
oil  obtainable  would  repay  the  cost  of  collecting 
the  acorns,  while  the  oil-cake  would  furnish  a 
valuable  feeding  stuff.  Baker  and  Hulton 
(Analyst,  1917742»  361)  found  that  a  ton  of 
fresh  acorns  from  Quercus  nbur  yielded,  on  the 
average,  16*76  cwt.  of  kernels,  corresponding  to 
8-6  cwtw   of  dry  kernels.    Two  specimens  of 

S«led  acorns  liad  the  f oUowins  composition : 
oistnre,  146  and  3*32 ;  ash,  2*26  and  2*70 ; 
oil,  6-0  and  4*7;  proteins,  6-66  and  7'76 ; 
reducing  sugars,  4*9  and  8i8 ;  cane  sugar,  1*9 
and  OT;  starch,  67*1  and  667 ;  pentosans, 
3*2;  and  crude  fibre,  2*2  and  2*28  p.c.  Bv 
hydiolysing  the  crushed  nuts  with  dilute  sul- 
phtirio  adC  and  neutndising  and  fermenting  the 
filtrate  12*7  p.o.  of  alcohel  (calculated  on  the 
freeh  acorns)  was  obtained.  Acorns,  unlike 
chestnuts,  do  not  appear  to  contain  a  liquefying 
enzyme. 

An  oil  extracted  from  the  acorns  of  Q. 
agrifoUa  was  fluorescent  and  of  a  deep  brown 
colour.  It  had  sp.gr.  0*9162  at  16**,  and  iodine 
value  100*6,  and  belonged  to  the  same  type  of 
oils  ae  arachis  oil  (Blasaale,  J.  Amer.  Chem.  Soo. 
1896,  17,  936).  C.  A.  M. 

AGORUS  CALAMUS  (Linn.).  The  common 
Bweet  flag.  The  root  is  used  by  distillers  to 
flavour  gin,  and  the  essential  oil  by  snuff- 
makers  for  scentinganuff.  It  contains  a  glucoside 
termed  oconn  C,7HioO«  (Faust,  Bull.  Soo.  chim. 
[2]  9,  392 ;  Thorns,  Arch.  Pharm.  [3]  24,  466) 

(9.  CAI.AMUS). 

AGRIDIME  CitH,N.    Crude  anthracene  con 
*AiM  basic  substaaoea,  and  among  them  aori- 
dhie,  which  can  be  isolated  by  extracting  it  with 
difaite  solphnrio  acid  and  addixiff  potassium  di- 
chromate  to  the  add  solution.  The  precipitated 


acridine  ohromale  is  then  recrystallised  from 
water,  treated  with  ammonia,  and  the  base  orya- 
taUiaed  from  hot  water  (Graebe  and  Caro, 
Annalsn,  168,  266 ;  Ber.  13,  99), 

Acridins  has  alao  been  obtained  syntheti- 
cally by  paaamg  the  v^onn  of  orthotolylaniline 
and  of  orthoditolylamiiie  through  a  tube  heated 
to  duU  redneaa  (Q.,  Ber.  17, 1370) ;  by  severally 
heating  formio  add  and  diphenylamine  (Bemth- 
sen  1^  Bender,  Ber.  16,  767,  1802).  chloroform, 
diphenylamine  and  lino  oxide  (Fiacher  and 
Koroer.  Ber.  17, 101 ),  and  aniline  and  salicvWde- 
hyde  (Mohlao,  Ber.  19,  2461)  with  smo  chlonde ; 
by  passing  o-amidodiphenyl  methane  through 
a  layer  oi  lead  oxide  heated  to  dull  redness 
(Fischer  and  Schutte,  Ber.  26,  8086).  By  dia- 
tiUtng  tetrahydit)aoridine  with  litharge  (Borsche, 
Ber.  4U  2203),  and  also  from  aoridone  (Decker 
and  Dunant,  Ber.  39,  2720;  UUmann,  Bader 
and  Labhardt,  Ber.  40,  4796). 

From  iodobenzene  and  o-aminobenxaldehyde 
boiled  with  nitrobenzene,  aodium  carbonate 
and  copper  powder  (Mayer  and  Stein,  Ber.  1917, 

60,1306).  „.  „ 

Properties.— Aisn^ne  crvatalliaes  m  smaU 
colourleas  needles,  or  four-sided  rhombic  prisms. 
■ublimeB  at  100%  melts  at  111%  boila  above  360*" 
without  decomposition,  and  distils  with  steam. 
It  is  aparingly  soluble  in  hot  water,  but  readily 
soluble  in  alcohol,  ether,  or  carbon  disulphide, 
yielding  solutions  showing  a  blue  fluorescence. 
Whenuihaled  either  as  dust  or  vapour  it  causes 
violent  sneezing,  and  in  solution  both  it  and  its 
salts  cause  much  irritation  on  the  skin.  On 
treatment  with  nitric  acid  it  yields  two  nitro- 
derivativee  (m.p.  164*»  and  214*)  and  a  dinitro- 
derivative  (G.  and  C.) ;  potassium  permanganate 
oxidises  it  to  2 : 3-qumolinedicarboxylic  acid 
C»H5N(C0,H)„  and  sodium  amalsam  reduces  it 
to  hydroacridine  Ci,HiiN  (B.  and  B.,  Ber.  10. 
1971;  B.,  Ber.  16,2831).  The  salts  are  jrellow  and 
crystallise  well,  but  are  decomposed  into  their 
constituents  on  boiling.  Heated  with  hydrogen 
and  finely  divided  nickel,  it  forma  2  :  3-dimethyl 
quinoline  (Padoa  and  Fabria,  Atti  R.  Acad. 
Lined,  1907,  [v.l  16,  i.  921).  The  halo^jen  addition 
compounds  of  acridine  and  its  denvativos  are 
formed  by  the  direct  action  of  the  halogen  on 
the  acridine  (Senier  and  Austin,  Chem.  Soc.  Trans. 
1904,  1196) ;  or  by  the  action  of  a  mixture  of 
phosphorus  oxychloride  and  pentachloride  on 
thioacridone  (Edinger,  Ber.  33,  3370 ;  D.  R.  P. 
120686 ;  Edinger  and  Arnold,  J.  pr.  Chem.  [ii]  64, 
182,  471 ;  D.  R.  P.  122607) ;  for  other  methods, 
compare  Dunstan  and  Stubbs  (Ber.  39,  2402; 
D.  R.  P.  126796),  Graebe  and  Lagodzinski 
(Annalen,  276,  48).  Alkyl  iodomagnesium  com- 
pounds of  acridine  have  also  been  obtained 
(Senier,  Austin,  and  Clarke,  Chem.  Soo.  Trans. 
1906, 1469).  When  exposed  to  sunlight  acridine 
forms  pale-yellow  crystals,  m.p.  276°  (Omdorff 
and  Cameron,  Amer.  Chem.  J.  1895,  17,  658). 
3 : 7-dimeihyl-  2  *.  8-dlainUioaerldlne  ^  or  acrt- 

»  The  system  of  nnmbering  the  poBltlons  In  the 
acridine  serlea  adopted  in  this  article  and  In  that  on  the 
"  Acridine  Dyeatufls,"  Uthat  used  In  Klchter's  Lexikon 
viz.: 


70 


AORtDINE. 


dine  yeaow  NH,<5,H,Me<:^^^^,HtMeNH, 

IB  obtained  by  heating  under  preeBure  tetramino- 
ditoly Imethane  witJi  hydzochlozio  aoid  and  water, 
the  product  ia  then  oxidised  with  ferrio  ohloride 
or  potassium  percarbonate  Kfifi^  or  hydrogen 
peroxide,  and  the  resulting  metaUio  salt  decom- 
posed with  hydrochloric  acid  (D.  R.  P.  62324; 
Lymn,  J.  Soo.  Ghem.  Ind.  1897, 16,  406 ;  UU- 
mann  and  Mari6,  Ber.  34, 4308 ;  Haaae,  Ber.  36, 
689).  It  forms  yellow  crystals  melting  above 
300^  soluble  in  alcohol,  acetone  and  pyridin, 
and  forming  a  yellow  solution  in  sulphunc  acid 
with  a  ffreen  fluorescence.  It  yields  deriyatiTcs 
which  form  yellow,  orange,  brownish-,  greenish-, 
and  reddish-yellow  dyes,  and  can  be  used  on 
cotton,  leather,  wool,  and  silk.  The  following 
are  some  of  the  methods  of  preparation : 
(1)  heating  with  mineral  acids  unaer  pressure, 
when  it  yields  aminohydroxy-  and  dihydroxy- 
dimethyl  acridine  (D.  R.  P.  121686;  Chem. 
Zentr.  1901,  IL  78;  J.  8oc.  Chem.  Ind.  21, 
37) ;  (2)  heating  with  monochloracetic  aoid  and 
water  under  pressure  (D.  R.  P.  133788 ;  Chem. 
Zentr.  1902,  ii.  616 ;  D.  R  P.  136729 ;  Chem. 
Zentr.  1902,  ii.  1396) ;  (3)  heating  with  formalde- 
hyde  and  mineral  acids  under  pressure  (D.  R.  P. 
136771 ;  Chem.  Zentr.  1902,  iL  1233 ;  J.  Soa 
Chem.  Ind.  21,  112,  644,  402);  (4)  by  treatment 
with  formaldehyde  and  aromatic  bases  (J.  Soc. 
Chem.  Ind.  22,  140 ;  D.  R.  PP.  131366, 132116 ; 
Chem.  Zentr.  1902,  iL  172 ;  i  1288) ;  (6)  heating 
with  benzyl  chloride  in  presence  of  nitrobenzene 
(J.  Soo.  Chem.  Ind.  21,  701,  1630) ;  (6)  treating 
with  aqueous  formic  acid  {ifnd,  21, 00) ;  (7)  hea^ 
ing  with  glycerol  at  160*-180*  (D.  R  P.  161206) : 
(8)  alkylation  (Ullmann  and  Mari6,  Ix, ;  D.  R  P. 
79703;  J.  Soc.  Chem.  Ind.  19,  1010;  24, 
840). 

PhenylaerUlne  Ci,Hi,N  is  obtained  by  heat- 
ing diphenylamine  with  benzoic  acid  and  zino 
cUoride  at  260*  (Bemthsen,  Ber.  16,  3012 ;  16, 
767,  1810),  and  melts  at  181*.  The  hydroxy- 
pheMylacridines  which  form  yellow  dyes  m 
minwal  acids  can  be  obtained  similarly  by  usiuA 
the  correepondinff  hydroxy  acid  (Landauer,  BulL 
Soc.  chim.  31,  lwZ\ 

Other  acridine  dyes  can  be  obtained  by 
heating  tetraminoditolylmethane  or  the  leuoo- 
compounds  of  amino-aoridines  with  mineral  acid 
and  alcohd  under  pressure,  the  shade  depending 
on  the  quantity  and  natmre  of  alcohol  and  m 
acid  used  (J.  Soc  Cbem.  Ind.  20,  888;  22, 
1126 ;  23,  932).  Also  by  the  interaction  of  an 
aromatic  or  aJiphatic  m-diamine  with  an  alde- 
hyde {ibid.  21,  1629;  Chem.  Zeit.  14,  334; 
J.  Soc.  Chem.  Ind.  17,  673;  22,  1241).  By 
heating  the  formyl  deriTatives  of  m-diamines 
with  ammonia  salts  or  salts  of  organic 
bases  at  160*-200*  (D.  R.  PP.  149409, 
149410).  For  other  methods  of  preparing 
acridine  deriTatives,  many  of  which  have  dyeinff 
properties,  compare:  Bizzarri,  Qazz.  chim.  itaL 

20,  407  ;  Decker,  J.  pr.  Chem.  163,  161 ;  Mohlau 
and  Fritzsche,  Ber.  26, 1034 ;  Volpi,  Oazz.  chim. 
itaL  21,  ii  228;   J.  Soa  Chem.  Ind.  19,   732; 

21,  338,  701,  911,  1628 ;  Goodwin  and  Senior, 
Chem.  Soc.  Trans.  1902,  286 ;  J.  Soc.  Chem.  Ind. 

22,  23,  90 ;  D.  R.  PP.  133709, 107517 ;  Ullmann, 
Ber.  36,  1017,  1026;  D.  R  P.  141297,  141366; 
"^unzley  and  Decker,  Ber.   37,  676;  Fox  and 

iwitti  CiMm.  Soo.  Trani.    1904,  629;   1900^ 


1068;  Sohdpfl,.Ber.  26,  1121;  Ber.  87,  2316; 
Duval,  Compt  rend.  142,  341 ;  Koenigs,  Ber.  3^ 
3699 ;  Ullmann  and  Maag,  Ber.  40, 2616 ;  Austin, 
Oiem.  Soo.  Trans.  1908, 1760 ;  D.  R  PP.  118075, 
162662 ;  Pope  and  Howard,  Chem.  Soc.  Trans. 
97,  83. 

Ni4>hthaerldine  and  its  deriyatiyes,  which 
can  also  be  used  as  dyes,  haye  been jraepared  (J. 
Soc.  Chem.  Ind.  18,  826;  19,  237  ;  Ullmann  and 
Naef,  Ber.  33,  906,  912,  2470 ;  J.  Soc.  Chem.  Ind. 
20,  37,  673 ;  D.  R.  P.  126444 ;  XTllmann  and 
Baezner,  Ber.  86,  2670  ;  37,  3077  ;  Ullmann  and 
Felzyadjian,  tbid.  36,  1027;  Ullmann  and  Farre, 
ibid,  37,  2922 ;  Ullmann  and  Fitzenham,  ibid, 
38,  3787 ;  Baezner  and  Gardiol,  ibid,  39,  2623 ; 
Baezner,  ibid.  2650 ;  Senior  and  Austin,  Chem. 
Soc.  Trans.  1907,  1233,  1240 ;  Senior  and  Comp- 
ton,  ibid,  1907,  1927 ;  Baezner  and  Gueorgnieff, 
Ber.  39,  2438). 

In  the  case  of  many  of  the  naphthacridine 
deriyatiyes,  patents  haye  been  taken  by  Ullmann 
(D.  R.  PP.  104667,  104748,  108273,  117472, 
119673, 123260, 127686, 128764, 130721, 130943): 
the  further  alkylation  of  some  of  these,  as  wdl 
as  of  other  acridine  compounds  has  been  patented 
by  the  A.-G.  fllr  Anilin-Fabrikation  (D.  R.  PP. 
117066,  129479). 

ACRIDIIIE  DTB8TUFFS.  Acridine,  though 
colourless,  shows  absorption  bands  in  tiie  ultra- 
yiolet.  The  salts  are  yellow,  and  the  addition 
products  with  alkyl  halides  are  also  coloured, 
n^or  absorption  spectra,  see  Dobbie  and  Tinkler, 
Chem.  Soc.  Trans.  1906,  87,  269.)  The  salts 
of  acridine  itself  are  useless  tinctoriaUy,  but 
amino-  and  alkyl-amino-  deriyatiyes  of  acri- 
dine, phenylaoridine,  &iC.,  are  useful  dyestuffs, 
generally  producing  yellow  shadea.  For  the  pre- 
paration 01  these  sub6tances,synthe6is  is  generally 
resorted  to,  although  acridine  may  be  nitrated 
(Graebe  and  Caro,  Annalen,  1871, 168,  276),  and 
o-nitro-acridine  has  been  reduced  to  an  amino- 
acridine  (Anschaiz,  Ber.  1884,  17,  437). 

The  trinitrophenylacridine  obtained  by  direct 
nitration  of  phenylacridine  gives  a  dyestuff  on 
reduction  (T  triammophenyla^dlne),  which  dyes 
silk  yellow ;  no  use  seems  to  have  been  made  of 
this  observation  (Bemthsen,  Annalen,  1884, 
224,30). 

One  dyestuff  of  the  acridine  series,  ehtye- 
aniline,  is  formed  as  9  by -product  in  the  manu- 
facture of  magenta  (Hofmann,  Jahresb.  1862, 
346).    Its  constitution 

N 


OCO"- 


NH. 

was  determined  bv  0.  Fischer  and  G.  Komer ; 
probably  two  molecules  of  aniline  and  one  of 
p-toluidine  condense  when  oxidised  to  opp- 
triaminotriphenylmethane,  this  yielding  chrys- 
aniline  when  further  oxidised.  This  view  is 
supported  by  the  fact  that  ^en  opp-triamino- 
tnpnenylmethane  is  heated  with  arsenic  aoid  to 
160*--180*,  chrysaniline  is  mroduoed  (Annalen. 
1884,  226, 188). 


AORIDINE  DTESTUFFS. 


71 


The  piooeaiea  for  preparing  amino-  dexira- 
trres  of  aoridine  on  a  teohnioal  soak  may  be 
Ohirtrated  by  the  methods  of  ]neparing  benuh 
fttome,  rkeoMnet  and  diammoaondytbemoic  add, 

Symmetrioal     diamino-aoridines     are     ob- 


tamed  by  the  oondensation  of  aldehydea  with 
»-dttunmea,  xemoval  of  the  elements  of  ammonia 
from  the  xesnlting  tetra-amino-  compoond  by 
heating  with  hydrochlorio  acid,  and  oxidation 
cithe  dihydro-aoridine  thna  prodnoed  with 
farrio  fthloiide.  In  the  ease  of  benzoflavine 
beozaJdehyde  and  m-tolnylene-diamine  aro 
enployed* 

C^,-CHO+2  ^J^V=»  =H.0+ 

NhXNnH,        NH,./\nH,  (HQ) 

^•\AcH(C.H.)AyOH.     -* 
NH 

CH 


C.H, 

The  reaction  is  capable  of  considerable  modi- 
ficatkm ;  thns  from  formaldehyde  and  dimethyl- 
n-pheny]eoediamine,  acridine  orange  is  produced 
in  an  analogons  manner.  It  should  be  noted, 
bovever,^  that  m-^henylenediamine  gives  pro- 
dnote  v^ich  are  CTidently  mixtures,  and  cannot 
be  purified  (B.  Ueyer  and  R.  Gross,  Ber.  1899, 
32,2365). 

Dfaminoacridine  may,  howeyer,  be  obtained 
fiom  pj/-dUaaino-diphenylmethaiie  {see  below). 

The  reaction  between  an  aldehyde  and  a 
■i-diamine  may  be  carried  out  in  two  stages; 
Meyer  and  Qross  {Le,  p.  2358),  for  example, 
prepared  a  monobenr^lidene  deriyative  of  m- 
tolaylenediamine  and  converted  this  into 
tetraminoditolyl-phenylmethane  by  warmins 
its  alcoholic  solution  with  the  hydrochloride  m 
la-tohiylenediamine  for  three  hours  at  60*-7(y*. 
Acridine  itaelf  may  be  obtained  in  good  yield 
by  beating  salicybdene-aniline  with  ^osphorus 
peotoxide  to  260'^(BUu,  Monatsh.  1897, 18, 123). 

A  cloeely-related  synthesis  of  acridine 
deriTatiyes  is  that  of  F.  Ullmann  and  R  Naef 
(Ber.  1900,  33,  905).  When  dihydroxydi- 
naphthylmethane,  the  product  of  the  interaction 
of  fonnaldehyde  and  3-naphthol,  is  heated  with 
p>toliiidine  hydrochloride,  methylhydronapth- 
arridine  is  pnoduced  with  elimination  of  /8- 
naphthoL 

CH^Ci«H«-OH),  +  NH,-C^4-CH, 


is  obtained  from  m-amino- 
pheaylaaramine  or  tetramethyldiaminobenzo- 
pkenoMMd afpheaylenediamine  at  aOO*.  uing 
sae  chlondie  m  oonnwiiing  kgent. 


(OH,),n/\ 


A 

N<C 


nh/\nh. 


N 


-2H^0  + 


(CH,).N 


y\y 


\/\ 


VxoA; 


NH, 


f(CH,), 

&'ome  derivatives  of  xanthene,  when  ener- 
getically treated  with  ammonia,  suffer  replace- 
ment of  the  pyrone  oxygen  atom  by  an  imino^ 
group.  By  tne  prolongra  heating  oi  fluorescein 
with  ammonia  under  pressure,  K.  Meyer  (Ber. 
1888,  21,  3376)  obtained  an  aoridine  derivative, 
to  which  one  of  the  three  following  constitutions 
is  assignable : — 


NH 


N 


,NH, 


NH 


I       . 

c.Hy 

COOH 
NH, 


\/\nh, 

/\/    or 


The  salts  of  the  tetra-ethyl  derivative  of  this 
compound  form  the  dyestun  known  e^fiaveaeine. 

Aeridine  Qnngo  NO  (Farbwerk  Hflhlheim, 
D.  R.  P.  59179, 17  Dec.  1889),  Gi,H^[N(GH,)  J,. 
HGl*ZnGl,  was  discovered  by  Bender.  It  is 
produced  by  condensation  of  dimethyl-m- 
phenylenediamine  with  formaldehyde  and  pro- 
ceeding according  to  the  method  referred  to 
above.  It  forms  an  orange  powder  which 
dissolves  in  water  or  alcohol  with  orange- 
red  colour  and  greenish  fluorescence.  Tne 
aqueous  solution  is  reddened  by  hydro- 
cmoric  acid ;  sodium  hydroxide  gives  a  yellow 
precipitate.  The  solution  in  concentrated  sul- 
phuric acid  is  nearly  colourless  and  has  a  greenish 
fluorescence,  dilution  with  water  produces  suc- 
cessively red  and  oranja^  colouration.  The  dye 
gives  orange  shades,  fairly  fast  to  light  and  soap, 
on  cotton  mordanted  with  tannin;  it  is  also 
suitable  for  printing  and  leather-dyeinf. 

The  analogous  dyestuff  from  £ethyl-m- 
henylenediamme  is  described  in  D.  K.  P. 
7609,  the  substances  derived  from  monoalkyl- 
phenylenediamines  in  D.  R.  P.  70935. 

Another  method  of  preparing  acridine  orange 
is  to  heat   12  kilos,   of  aminodimethylaniline 


t 


72 


ACRIDINE   DYESTUFPS. 


either  with  10  kilo4.  of  formic  aoid  (sp.gr.  1*2)  and 
10  kilos,  of  zino  chloride  gradually  to  16O'*-10O^ 
or  with  12  kilos,  of  dehydrated  ondio  acid,  10 
kilos,  offflycerol  and  11  kilos,  of  zinc  chloride  to 
150*.  Heating  and  stirring  axe  continued  as 
long  as  any  darkening  of  shade  can  be  observed, 
ammonia  is  liberated  during  the  reaction,  and 
formic  acid  having  been  employed  instead  of 
formaldehyde,  the  product  when  worked  up 
yields  thedyestuJS  instead  of  its  leuco-  compound 
(D.  R.  P.  67126). 

The  formyl  derivatives  of  m-diamines  may 
also  be  used  (D.  R.  PP.  149049,  161699),  or  the 
*  methane '  carbon  atom  may  be  furnished  by 
various  formyl  derivatives  such  as  formanilida 
(D.  R.  P.  149410). 

Aertdine  Orange,  R  extra  (Farbwerk  Mflhl- 
hcim,  D.  R.  P.  68908,  7  Feb.  1890).  The  dye- 
stuff  is  the  hydrochloride  of  tetramethyl(ua- 
mino-5-phenyle4;ridine,  and  is  obtained  from 
dimethyl-m-phenylenediamino  and  benzaldehyde. 
Its  reactions  and  uses  are  similar  to  those  of 
Mark  NO. 

D.  R.  P.  68908  also  mentions  the  use  of 
m-aminodimethyl-o-toluidine.  If  the  latter  base 
bo  condensed  with  p-nitrobenzaldehyde  to  a 
t^iphenvlmethane  derivative,  the  nitix)- sroup 
reduced  and  condensation  and  oxidation  e£oted 
in  the  usual  way,  an  acridine  dyestuff  possessing 
two  tertia^  and  one  primary  amino-  group  is 
obtained  (D.  R.  P.  7(X)60;  compare  D.  R.  P. 
71362). 

The  use  of  acetaldehyde  as  a  component  was 
claimed  by  the  Ges.  f.  C^m.  Lid.  (D.  R.  P. 
143893,  13  March,  1902). 

AerldiiM  TeUow  (Farbwerk  Mfihlheim,  D.  R.  P. 
52324,  27  June,  1889)  was,  like  the  two  pre- 
ceding^ colours,  discovered  by  Bender.  Its 
constitution  is  that  of  a  2  : 8-diaimno-3 :  7- 
dimethvlacridine  hydrochloride;  it  is  produced 
from  zormaldehydB  and  m-toluylenedianine. 
It  forms  a  yellow  powder  soluble  in  water  and 
alcohol  with  yellow  colour  and  green  fluore- 
scence; yellow  precipitates  are  obtained 
with  hy<&)ohloric  acid  (hydrochloride)  and 
sodium  hydroxide  (free  base).  Silk  is  dyed  a 
greenish  yellow  with  oreen  fluorescence,  cotton 
(tannin  mordant)  is  colonred  yellow. 

The  salts  with  aliphatic  acids,  e.g,  formate 
and  acetate,  are  more  soluble  (Farbenfabriken 
vorm.  F.  Bayer,  D.  R.  P.  140848,  13  Maroh, 
1903).  Acridline  yellow  is  converted  into  an 
oran|^  yellow,  more  easily  soluble  dyestuff  by 
heatmg  with  twice  its  weight  of  glycerol  for 
4-6  hours  to  170'*-180'*  (Badische  Anilin  und 
Soda-Fabrik,  D.  R.  P.  151206,  26  July,  1903). 

(For  the  action  of  aldehyde  on  aniline  yellow, 
Mep,  R.  P.  144092.)  Ck>mpounds,  probably  of 
acridinium  type,  are  obtained  from  aniline 
yellow  by  the  action  of  monochloracetic  aoid 
(M.  L.  B.,  D.  R.  PP.  133788,  136729,  152662) 
and  other  dyestuA  by  condensation  with 
formaldehyde  and  m-diamines  (D.  R.  PP.  131365, 
132116,  135771).  Either  one  or  both  of  the 
amino- groups  in  acridine  yellow  and  analogous 
dyestum  are  replaced  by  hydroxyl  on  heating 
with  dilute  sulphuric  acid  to  180^-220*  (D.  R.  P. 
121686),  and  similar  compounds  may  be  obtained 
trom  formaldehyde  by  condensation  with  amino- 
^resols  (D.  R.  P.  120466). 

Dibenzyl  aniline  yellow  is  claimed  by  Bayer 
Co.  as  a  useful  leather  dye  p.  R.  P.  141297). 


Benzoflavine  (several  marks)  2:8-diamino- 
3 : 7-dimethyl-5-phenylacridine  hydrochloride 
C„H4N(C,H,)(NH,),(CH,)„HC1,  wss  disooveied 
by  Rudolph  in  1887,  and  introduced  commercially 
by  K.  Oehler  in  1888  (D.  R.  PP.  43714,  28  July, 
1887 ;  43720, 45294, 45298).  Its  preparation  has 
been  given  above.  The  dye,  which  is  usually  mixed 
with  dextrin,  forms  an  orange  pNOwder,  difScultlv 
soluble  in  cold  water,  more  easily  in  hot.  Both 
aqueous  and  alcoholic  solutions  are  orange,  with 
strong  green  fluorescence.  Hydrochloric  acid 
gives  an  orang»  precipitate,  sodium  hydroxide 
liberates  the  ySlowish- white  base.  The  solution 
in  concentrated  sulphuric  acid  is  greenish  yellow, 
and  shows  a  very  strong  green  fluorescence.  It 
may  be  used  for  dyeing  both  mordanted  and 
unmordanted  cotton.  &e  acetate  and  lactate 
are  more  readily  soluble  (Bayer,  D.  R.  P. 
142453,  19  April,  1902) ;  it  behaves  like  acridine 
yellow  when  heated  with  glyceroL 

The  Patent  Phosphines  of  the  Ges.  f.  Chem. 
Ind.  in  Basel  are  obtained  bv  alkylation  of 
benzoflavine  and  acridine  yellow  (D.  R.  P. 
79703 ;  compare  D.  R.  P.  131289). 

Coriophosphines  (Baver  &  Oo.).  These  dye- 
stuffs,  which  are  suitable  for  leather-dyeing,  are 
probably  unsymmetrioally  alkylated  diamino- 
acridines  obtamed  by  condensation  of  formalde- 
hyde with  one  molecule  of  an  asymmetrically 
dialkylated  m-diamine  and  one  molecule  of  a 
non-fukylated  or  monoalkvlated  m-diamine,'  with 
subsequent  elimination  of  ammonia,  and  oxida- 
tion (D.  R.  P.  133709). 

ChrysaniUne  Ci,Hj,N  occurs  under  many 
other  names  commercially,  e,g.  Leather  yellow. 
Xanthine,  Philadelphia  yellow  G,  Leather  brown, 
Phosphine  (several  marks),  ko.  Reference  to 
its  occurrence  in  the  manufacture  of  magenta 
has  already  been  made.  Numerous  methods 
for  preparing  homologues  and  analogues  of  this 
substance  have  been  patented  (D.  R.  PP.  65985, 
78377,  79263,  79685,  79877,  81048,  94951, 
102072,  106719,  114261,  116353).  The  method 
adopted  for  this  purpose  by  Meister,  Lucius,  and 
Brflining  may  be  mentioned  (D.  R.  P.  65985, 
2  AprU,  1892).  p-Toluidine  and  its  hydro- 
chloride are  heated  with  ferric  chloride  (oxyoen- 
carrier),  and  m-nitroaniline  gradually  adiaed. 
The  resulting  dyestuff  is  the  next  higher  homo- 
logue  of  chrysamline,  containing  a  methyl-  group 
in  position  7. 

Acoordinff  to  Friedlander  (Fortschritte  der 
Theerfarbenfabrikation  V.  373),  the  yields  pro- 
duced by  this  method  are  not  sood,  but  the 
reaction  between  p-aminobenzaraehyde  or  a 
derivative  and  phenyl-m-phenyleno-  (or  toluyl- 
ene-)  diamine  proceeds  nearly  quantitatively : 

C.H,NH-C^,NH,  +  C,H4(NH  JCHO  +  0 

=  2H,0  +  C.H,<"?>C,H,NH, 
.^C-C.H^-NH, 
B.  A.  8.  F.j  p.  R.  PP.  94951,  102072). 

Chrysaniline  forms  an  oranffe-yeillow  powder, 
soluble  in  water  and  alcohol  with  reddish-yellow 
colour  and  yellowish-green  fluorescence.  The  solu- 
tion is  unaltered  by  hydrochloric  acid ;  sodium 
hydroxide  gives  a  bright  yellow  precipitate. 
Chrysaniline  is  chiefly  used  in  leather  dyeing. 

CorioflaviiMi  (Griesheim-Klektron).  'Siese 
dyestuffs,  which  occur  commercially  as  marks 
G,  GG,  R,  and  RR,  are  used  in  leather-dyeing 
and  calico-printing.    They  form  red  or  xeddish. 


ACRIDINE   DYKSTUFFS. 


brown  powdeo.  whidi  diMolYO  in  concentrated 
solphuno  acid  with  ydk>w  or  otange  oolouiation 
and  greoi  flnorasoenoe;  these  mntiotts  tain 
red  or  reddkh-brown  on  dilution. 

FlwMaliie  (Meister,  Lociiis,  and  Br&nni|F, 
D.  R  P.  49850,  11  May,  1889)  is  a  tetraethyl- 
diaminoacridylbenzoic  acid,  which  is  obtained 
by  heatinff  m-aoetaminodimethylaiiiline  with 
^thalio  auiydride.  It  has  been  ezamined  by 
Grandmongin  and  Lsng  (Ber.  1909,  42,  4014). 

The  hydrochloride  crystallises  in  shining 
browmsh-yellow  needles,  tiiie  sulphate  in  prisms 
exhibiting  a  cantharides  lustre.  The  base  is 
precipitated  from  the  salts  by  sodinm  carbonate, 
and  forms  ^den-yellow  shining  leaflets. 

Haveosme  dyes  silk  golden  yellow  (yellowish- 
gre^i  flaorescenoe)  from  a  feebly  acid  bath ;  wool 
and  cotton  (tannin  mordant)  are  » coloured 
reddish  ydlow.     The  colours  are  fast. 

Substances  doerly  related  to  flaveosine  are 
obtained  by  the  esteiification  of  the  produot  of 
the  interaction  of  ammonia  and  fluoresoein 
(B.  A.  S.  F.,  D.  R.  PP.  73334,  75933  ;  compare 
D.  R.  P.  141356). 

Kheonine  (Badische  Anilin  und  Soda-Fabrik). 
This  dyestuff  was  dtscoyered  by  G.  L.  MfUler 
(D.  R.  P.  82989,  16  Dec.  1894).  Its  method  of 
preparation  has  already  been  f^yen.  Rheonine 
farms  a  brown  powder,  soluble  in  water  and 
alQohol,  with  browmsh-yellow  colour  and  green 
fluor^oenoe.  Hydrochloric  acid  turns  the  solution 
brownish-red,  caustic  soda  gives  a  briffht  brown 
precipitate.  It  is  used  for  obtaining  brownish- 
yelTow  shades  on  leather  or  cotton  (tannin).  Two 
marks,  N  (brighter),  and  A  (darker),  are  in  use. 


78 


The  use  of  diaminobanaophenoue  and  of 
Michler's  hydrol  for  condensation  with  «i«dia* 
mines  have  been  patented  (M.  L.  B.,  D.  R.  P. 
89660  and  B.  A.  &  F.,  D.  R.  P.  85199  ro> 
spectively). 

Many  acridine  and  naphthaoridine  dyestufis 
containing  only  one  amino-  group  hare  been 
described  (D.  R.  PP.  104667.  107517,  107626» 
108273,  118075,  118076,  125697,  130360);  and 
it  has  also  been  obeerved  that  dyestuflfs  can  be 
obtained  when  onlv  one  molecular  proportion  of 
a  m-diamine  is  used  with  formaldehyde  (D.  R.  P. 
136617). 

TtSrpallavliM.  The  2 : 8-^Hamlno-lO-methyl- 
acridonium  salts  first  acquired  interest  on 
account  of  their  trypanoctdal  action  (L.  Benda, 
Ber.  1912,  45^  1787).  As  mentionod  aboye,  the 
condensation  of  aldehydes  with  m-phenylene- 
diamine  gives  a  mixture  of  subswaoes.  If 
pp'-diamino-dtphenj^lmethane  is  nitrated  in  cold 
sulphuric  add  solution,  oo'-dinitro-M'-diamino- 
dipnenylmethane  is  produced.  The  latter  com- 
pound by  reduction  with  tin  and  hydrochloric 
add  and  heatins  the  resulting  solution  for  four 
hours  at  135**  gives  the  stanniohloride  of  2 : 8- 
diaminoacridine  (L.  CJassella  ft  Go.  D.  R.  P. 
230412).  After  aoetylation  of  the  amino- 
groups,  the  nitrogen  atom  of  the  pyridine 
nucleus  may  be  methylated  by  moans  of  methyl 
toluene-sulphonate  and  the  acetyl  sroups 
subsequently  removed  by  heating  with  a  mixture 
of  equal  volumes  of  water  and  hydrocMorio 
add  {e,g,  1*18).  The  steps  in  the  formation  of 
trypsiiflavine  may  be  represented  thus  :- 


NH/^         {^mt       NH,/\nO,  NO.r^NH,       NH.f^iNH,  NH,/NnH, 


vv^ 


I      I 


N 


™.Q^». 


NHAo       AoNH 


CH,       OSO.C.H, 


NH, 


reactions   of   trypaflavine   have    been    derivatives  have  no  particular  interest  tinotori- 
by  Ehrlich  and  Benda  (Ber.  1913,  46,    ally.     Anthraquinone-l :  2-aoridone  may,  how- 


The 
studied 
1931). 

More  recently  the  material  has  been  intro- 
duced as  an.  antiseptio  under  the  name  of 
Flavine,  since  changed  to  Acriflavine  (Browning, 
Gulbransen,  Kennaway,  and  Thornton,  Brit. 
Med.  J.  1917,  i.  73).  Whilst  most  antiseptios 
act  more  powerfully  in  water  than  in  blood 
serum,  this  behaviour  is  reversed  in  the  case  of 
flavine.  Thus  flavine  kills  Staphylococcus  aureriB 
at  a  dilution  of  1 :  20,000  in  water  containing 
0*7  p.0.  of  peptone,  but  at  1 :  200,000  in  blood 
seorom.  Moreover,  flavine  has  been  found  to 
have  a  low  toxidty. 

Aeridone  0,H4<^^>G«H4  and  its  simpler 


ever,  be  dyed  from  a  vat  giving  reddiflh-violet 
shades  on  cotton  (F.  Ullmann  and  P.  Oohsner, 
Annalen,  1911,  381,  9).  The  substanoe  is 
obtained  by  warming  o-carboxyphenylamino-l- 
anthraquinone  with  sulphuric  acid. 


=  H,0+ 


74 


ACRIDINB  DYESTUFfS. 


The  neoeawTy  carbo^lie  acid  can  be  obtained 
from  l-chloroanthxaqumone  and  anthranilic 
add  or  from  l-amimoanthraaiiiiioiie  and  o- 
chlotobenzoio  acid.  The  yielaa  are  better  by 
the  first  method,  bat  those  by  the  latter  prooefls 
may  be  raised  to  orer  90  p.o.,  espedalhr  if  in 
place  of  o-ohlorobenzoic  and,  its  methrl  ester 
be  used  (Meister,  Laciiu,  and  Briining,  D.  B.  P. 
240327;  F.  Ullmann  and  P.  Dootson,  Ber. 
1918,  51,  9).  On  condensing  1-anilino-anthra- 
quinone-2-carbozylio  add  a  mixture  of  o- 
carbozyphenylanuno-l-anthraquinone  and  1- 
aoiidiiieanthnqninone-2-carboxylio  add  is  ob- 
tained (Farbenf.  Torm.  Fr.  Bayer  &  Go.  D.  R.  P. 
262069). 

The  shades  obtained  with  anthraaninone- 
aoridone  axe  bat  little  altered  when  chlorine  is 
introdaced  in  position  4  of  the  anthraqoinone 
nadeos,  bat  the  amino-  and  p-tolaidino  deilTa- 
tives  dye  bloe  and  blnish-green  respeotlTely 
(Mdster,  Ladns,  and  Bnining,  D.  R.  P.  243686). 
Ullmann  and  liootson  have  also  prepared  de- 
rivatiTes  sabstitated  in  the  phenyl^  nadeos. 

The  dicarbozylio  add  obtained  from  anthra- 
nilic add  and  1 : 0-diohloroanthraqainone  may 
be  condensed  by  salphaiic  add  to  anthraqainone- 
1:2,  6 : 6-diacridone,  which  gives  a  deep  blae 
vat  and  dyes  bluish-violet  shades  (Ullmann 
and  Ochsner). J.  T.  H. 

ACRIFLAVIIIE  v.  Trypaflavine,  art.  Aobidinb 
Dybstutfs^ 

ACRODEXTBINS  v.  DBXTHora. 

ACROSE  V.  Gabbohydratbs. 

ACmnUM  Ac  230  or  226(7).  A  radio- 
active element,  discovered  by  Bebieme  in  the 
precipitate  prodaced  by  adcunff  ammonia  and 
ammoniam  salphide  to  the  filtrate  from  the 
hydrogen  salphide  predpitate  obtained  in  the 
coarse  of  analysmg  pitchblende  (Debieme, 
Gompt.  rend,  129,  693 ;  130,  906).  In  fraction- 
ating the  rare  earths  thas  obtained  from  pitch- 
blende by  means  of  their  doable  nitrates  with 
magnesium  nitrate,  actinium  accumulates  in  the 
more  soluble  portions,  together  with  neodymium 
and  samarium  (Gompt.  rend.  139,  638).  The 
predominating  rare  earth  in  pitchblende  is 
thorium ;  but  actinium  also  occurs  in  uranium 
minflrals  containing  no  thorium  (SzilArd,  Ghem. 
Soa  Abstr.  1909,  ii.  663).  It  is  a  constant  con- 
stituent of  uranium  minerals,  and  is  probably 
derived  from  uranium  in  a  branch  disintegration 
series. 

Actinium  has  not  been  isolated  nor  have  its 
salts  been  obtained  pure.  It  is  similar  in 
chemical  properties  to  the  tervalent  rare  earth 
elements  of  the  cerium  group,  and,  of  these, 
resembles  lanthanum  most  dosdy,  beinf  more 
basic  (A.  von  Wdsbach,  Sitaongsberiohte  K. 
Akad.  Wise.  Wien,  1910,  119  [iia]  1 ;  Monatsh. 
1910,  31,  1159).  It  is  piecipitated  bv  ozaUc 
acid,  and  by  ammonia.  In  presence  of  ammo- 
nium salts  the  precipitation  of  actinium  is 
incomplete,  but  it  is  completdy  predpitated  in 
presence  of  manganese  from  Mac  solutions  as 
a  manganate.  Actinium  preparations  are 
highly  radioactive,  imparting  mduced  radio- 
activity to  surrounding  objects  (Gurie  and 
Debieme,  Gompt.  rend.  132,  548);  and,  like 
radium,  they  spontaneouslv  give  rise  to  helium 
(Debieme,  Gompt.  rend.  141,  383);  they  are 
not  luminescent.  Their  aqueous  solutions  slowly 
evdve  hydragen  and  oxygen  in  the  proportions 


necessary  to  form  water.  Anfelninm  aalts  also 
evolve  an  emanation,  an  inert  gas  having  a 
molecular  weight  of  approzimatdy  230  (218  or 
222  f ),  accordmg  to  diousion  experiments  (De- 
bieme, C!ompt.  rend.  136,  446,  767 ;  138,  411 ; 
Bruhat,  Gompt.  rend.  148,  628 ;  Russ,  Phil.  Kag. 
1909,  [vi]  17,  412 ;  Marsden  and  Wood,  Phfl. 
Mag.  1913,  [vi.]  26,  948),  and  condensing  to  a 
liquid  at  -120<'  to  -150°  (Kinoshita,  PhiL 
liag.  1908,  [vi.],  16,  121). 

The  spontaneous  decompodtion  of  actinium 
gives  rise  to  seven  successive  products:  radio 
adinium  (Hahn,  Ber.  39, 1605 ;  Phil.  Mag.  1907, 
[vi.]  13,  166),  which  is  chemically  non-separable 
from  thorium,  and  which  changes  into  iictinium 
X,  a  substance  soluble  in  ammonia  and  non- 
separable  from  radium  (A.  Fleck,  Trans.  Oiem. 
Soa  1913, 103,  381,  and  1052) ;  this  transforms 
into  actinium  emanation,  a  short-lived  gas  of 
the  argon  family,  from  which  actinium  A, 
a<kinium  B,  actintum  C,  and  actinium  D  succes- 
nvely  arise  (Hahn  and  Meitner,  Ghem  Soc. 
Abstr.  1908,  ii.  920) ;  they  constitute  the  induced 
active  deposit.  The  discovery  of  acHnium  A,  an 
exoesdvely  short-lived  product,  intermediate 
between  the  emanation  and  what  previously 
had  been  termed  actinium  A,  has  led  to  a 
change  of  nomenolatura,  the  products  previously 
termed  actinium  A,  B,  and  u  respeotivelv,  beii^ 
now  called  actinium  B,  0,  D  (Ratnerford, 
Phil.  Msg.  1911,  [vL  J  22,  621).  Actinium  B  is 
chemical^  non-separable  from  lead,  actinium 
O  from  bismuth,  and  actinium  D  from  thallium 
(Fleck,  1.6.).  Actinium  itself  is  rayless ;  all  the 
other  products  except  actinium  B  and  D  emit 
a-particlcs;  and  radio<Ktinium,  actinium  B, 
and  actinium  D  emit  /3-  rays  (Hahn  and  Mdtner, 
Ghem.  Soa  Abstr.  1908,  ii.  1007 ;  Gdger,  PhiL 
MsLg.  1911,  [vi]  22,  201 ;  Geiger  and  Nuttal, 
Phfl.  Ma^.  1912,  [vi.]  24,  647). 

Actinium  is  identioal  'with  the  substance 
emanium,  discovered  by  Giesd  {v,  Giesd,  Ber. 
35,  3608 :  36,  342 ;  37,  1696,  3963 ;  Debieme, 
Gompt.  rend.  139,  538 ;  Ann.  Phys.  1914  [ix.J 
2,  i2S ;  Hahn  and  Saoker,  Ber.  38,  1943 ;  cj. 
MarckwaM,  Ber.  38,  2264 ;  Soddy,  Chem.  News, 
1913,  107,  97). 

It  occupies  the  place  in  the  Periodic  Table 
between  radium  and  thorium,  and  is  chemically 
non-separable  from  mesothorium-2.  Its  parent^ 
'  eka-tantslum,'  has  been  separated  from  pitch- 
blende by  Hiafjlling  the  latter  in  chlorine  and 
carbon  tetrachlori£  vapour  at  a  low  red-heat. 
It  probably  occupies  the  place  in  the  Periodic 
Table  between  thorium  and  uranium,  and  jrives 
actinium  in  an  a-ray  change  (Soddy  and  Cran- 
ston, Proc.  Roy.  Soc.  1918.  94,  A  384). 

Hahn  and  Meitner  (Phys.  Zdts.  1918»  19, 
208)  independently  have  separated  and  studied 
more  extensively  the  parent  of  actinium.  This 
substance  they  call  '  prot-actinium,*  and  regard 
as  a  hifiher  homologue  of  tantalum.  It  emits 
a-particles  of  3*14  cm.  range.  Its  half- value 
period  lies  between  1200  and  180,000  yean. 
The  growth  of  actinium  from  tlus  substance  was 
observed:  (1)  by  means  of  a-ray  curves;  (2) 
by  daily  measurement  of  actinium  emanation 
extending  over  a  month;  (3)  by  the  active 
deposit  collected  in  increasinff  quantities  on  a 
n^atively  charged  plata  The  observations 
confirm  Garie*s  value  for  the  half-value  period 
of  actinium. 


ADENINE. 


75 


ADAUll.    BromdiethylAoetyl  urea 
(C,H,),CBr'CO-NHCOKH, 

Used  as  ahypnotio. 

ADAMmTUB  spar  v.  Corundrum. 

ADAMITE.  A  mineral  conaistixig  of  hydrated 
bask)  zino  arsenate  Zn|(As04)s'Zn(0H)„ 
diflooviBred  by  C.  Friedel  in  1866  as  a  few 
small,  -violet  orthorhombio  oiystals  on  silver 
ores  fiomCha&aroillo  in  Chile.  Since  then  it  has 
been  found  at  a  few  otlier  localities,  particularly 
in  the  ancient  zinc  mines  at  Lauiion  in  Greece. 
Here  it  oocnrs  in  some  abundance  as  bright 
green  (cupriferous)  or  yellowish  crystals  in 
cavities  of  the  cellular  zino  ores.  It  has  been 
prepared  artificially  in  a  crystalline  condition. 

More  recently  the  name  adamUe  has  bee» 
employed  as  a  trade  name  for  an  artificial 
corundum  manufactured  for  abrasive  purposes. 

L.  J.  S. 

ADAMOM.  Trade  name  for  dibromodi- 
hydrodnnamic  acid  bomyl  ester. 

ADANSONIA  DIGITATA  (linn.),  the  Baobab 
tree^  fields  a  fibre  which  has  been  used  in  paper- 
makmg.  Its  bark  (Gk>wik  Chentz  or  Ghuree 
Chentz)  is  said  by  Duchaiasaing  to  be  a  useful 
substitute  for  cinchona  (Dymook,  Pharm.  J. 
[31  7.  8). 

ADBNASB  V.  Enzymes. 

ADENINE,  Q-Aminopurine 


N:C(NHJCNH^ 

II       2>CH,3H,0 
:  N C-N^ 


<1h 


discovered  in  the  pancreatic  gland  and  spleen 
of  the  ox,  ooonzB  m  all  vegetable  and  animal 
tissues  ri<^  in  cells  (Kossel,  Ber.  1886,  18,  79, 
1928;  Zeitech.  ^yfdol.  Chem.  1886,  10,  248; 
Toshimura  and  tLania,  Zeitsch.  physiol.  Chein. 

1913,  88,  361 ;  Minuroto,  J.  0)U.  Agric.  Imp. 
Univers.  Toldo,  1912, 6, 63 ;  Smorodinzew,  Zeitscn. 
physiol.  Chem.  1912,  80,  218 ;  Zlataroff,  Zeitsch. 
Nahr.Genussm.  1913,26, 242;  Bass,  Arch.  f.  ezp. 
Pathol,  u.  Pharmak.  76,  40-64;  Winterstein, 
Landw.  Ver8.-Stat.  79  and  80,  641-662 ;  Chap- 
man, Chem.  Soc  Trans.  1914,  106,  1903-1904) ; 
thus  it  has  been  extracted  from  tea  leaves 
(Kossel,  Z.c),  from  beet- juice  {v.  Lippmann,  Ber. 
1896,  29,  2646),  from  beet-sugar  residues 
(Andrlik,  Zeitsch.  Zuckerind,  Bohm.  1910,  34, 
667-669),  0*06  p.a  pure  adenine  obtained,  from 
molasses  (Stoltzenoerg,  Chem.  Zentr.  1912, 
1616,  from  Zeitsch.  ver  deut.  Zuckerind,  1912, 
318),  from  the  young  shoots  of  bamboo  (Totani, 
Zeitsoh.  physiol.  Chem.  1909,  62,  113);  from 
human  excretory  products  (Kuiger  and  Schitten- 
helm,  Zeitsch.  physiol.  Chem.  1902,  36,  169), 
and  from  herring  brine  (Isaac,  Chem.  Zentr. 
1904,  it  647 ;  from  Beitr.  chem.  phvsiol.  Path. 
1904,  6,  600) ;  it  is  probably  one  of  the  degrada- 
tion products  of  nuclexn  (Schindler,  Zeitsch. 
physiol.  Chem.  1889,  13,  432),  and  is  found  in 
small  quantity  when  nudefn  is  heated  with 
dilute  sulphuric  acid  (Kossel,  Ber.  1886,  18, 
1928;    Jones   and   Richards,   J.    Biol.   Chem. 

1914,  17,  71 ;  1916,  20,  26-36). 

It  has  been  obtained  from  rice  polishings 
(Drummond  and  Funk,  Bio-chem.  J.  1914,  8, 
698-616),  and,  according  to  Funk,  is  of  distinct 
therapeutic  value  (Casunir  Funk,  J.  Physiol. 
1913,  46,  489 ;    also  J.  Bk>L  Cham.  1916,  26, 


431-466;  and  Harden  and  Ziiva,  Biochem.  J. 
1917,  ii.  172). 

Adenine  is  isolated  from  tea  extract  after 
the  removal  of  caffeine  by  precipitating  the 
cuprous  compound  C^H^fia^  bv  means  of 
copper  sulphate  and  sodium  bisulphite,  and  de- 
composing the  precipitate  with  ammonium 
sulpnide;  the  crude  adenine  is  then  isolated 
from  the  filtrate  in  the  form  of  the  sulphate. 
For  the  method  of  separatinff  adenine  from 
other  purine  ba^es  compare  Scnindler  (Zeitsch. 
physiol.  Chem.  1889,  13,  432).  For  recovery  of 
adenine  from  the  picrate,  see  Bamett  and  Jones 
(J.  Biol.  Chem.  1911,  9,  93-96).  The  syntheaiB 
of  adenine  has  been  effected  by  reducing  with 
hydriodic  acid  2-amino-2 :  8-dichloropurine  ob- 
tained by  the  action  of  aqueous  ammonia  on 
trichloropurine  (B.  Fischer,  Ber.  1897,  30,  2226 ; 
1898,  31,  104 ;  Bohringer  and  Sons,  D.  R.  P. 
96927,  24/3,  97 ;  Traube,  Annalen,  1904,  331, 
64). 

Adenine  crystallises  from  dilute  aqueous 
solution  in  long  rhombic  needles  that  become 
anhydrous  at  110%  and  melt  with  decomposition 
when  rapidly  heated  at  360'*-366''  (Fischer,  U.), 
and  sublime  in  microscopic  needles  without 
decomposition  at  220°.  Adenine  is  sparingly 
soluble  in  cold  (1 :  1086)  and  readily  soluble  in 
hot  water  (1 :  40) ;  sparingly  so  in  alcohol ;  in- 
soluble in  ether  or  cluoroform.  It  forms  com- 
Eounds  with  bases,  acids,  and  salts ;  with 
exose  (Maudel  and  Dunham,  Biochem.  J.  1912, 
xi.  86),  and  gives  mono-  and  dichloro-glucosides 
(Fischer  and  Helferich,  Ber.  1914,  47,  210-236). 
Adenine  c{-glucoside  has  m.p.  210^-276*^  (decom- 
posed), Wd  19°-20*  -lO-e^'^in  water,  -f  6'67'*  in 

^/hydrochloric  add.    The  nitraU 
C5H5N„HN0,.1H,0 

is  crystalline,  and  the  dry  salt  dissolves  in 
110 '6  parts  of  water ;  the  hyfirochhride 

CjHi^^HajH.O 

forms  transparent  monoclinic  prisms  a:b: cs 
20794:1:1*8127,  fi=QV  W  the  anhydrous 
salt  dissolves  in  41*9  parts  of  water ;  the  chlor- 
acetate  C5H5N5,C,H|0,C1  melts  and  decom- 
poses at  162''-163'' ;  tke  eulphaU 

(C,H^,)„H^04^H,0, 

the  aza2a<«CsHBN5,CaH,04,H.O,  and  dichromate 
(C5H^,)j,H2Cr,07  are  crystalline ;  the  picrate 
O^JS.fiJELJSfij  is  stable  at  220°,  and  is  so 
sparinffly  soluble  in  cold  water  (1 :  3600)  that  it 
is  used  as  a  means  of  estimating  adenine  in 
solution  (Ber.  1890,  23,  226) ;  the  addition  of 
sodium  picrate  will  precipitate  adenine  from 
exceedingly  dilute  solutions  (1 :  13,000)  (Bar- 
nett  and  Jones,  J.  Biol.  Chem.  Ix.) ;  the  picro- 
lonaie  G^^^JOi^^fi^^  crystallises  from 
water  and  melts  at  266°  (Levene,  Biochem. 
Zeitsch.  1907,  4,  320).  The  ptaiinkmride 
(C|H,Ne)|,HaPta«  crystallises  from  dilute 
solution  in  needks,  and  yields  the  saU 
C|H(N„HCl,PtCl4  when  a  concentrated  solu- 
tion is  boiled.  The  acetyl  derivative  CgHfNgAo 
does  not  melt  at  260°,  the  benzoyl  derivative 
CiH^NgBz  has  m.p.  234°-236°  (Kossel,  Ber. 
1886,  20,  3366).  The  fudhyl  and  benzyl  de- 
rivatives have  been  prepared  (Thoiss,  Zeitsch. 
physiol.  Chem.  13, 39<^.  Bromadenine  C^H^^^Br 
ui  strongly  basic,  forms  an  insoluble  picraU, 
and  on  oxidation  with  hydrochloric  acid  and 


76 


ADENINE. 


potassium  chlorate  yields  alloxan,  urea,  and 
oxalic  acid  (Bruhns,  Ber.  1890,  23,  225 ;  Kniger, 
Zeitsch.  phyaiol.  Chem.  1892, 16,  329).  Adenine 
is  oonTerted  into  hypoxanthine  by  the  action 
of  nitroiis  add  (Kossel,  Ber.  1885,  18,  1928). 
Adeoine^-fflucoside  troated  with  excess  of 
nitrous  acid  yields  hypoxanthine-c{-glucoside, 
m.p.  246^  [«]20'  -U-ff"  in  i^/soda,  +12-92'* 
in  ^/hydrochloric  acid  (Fischer  and  Helferich, 

Adenine-aracil-dinucleotide  is  obtained  as 
an  amorphons  powder  by  the  action  of  dilate 
ammonium  hydroxide  on  yeast-nucleic  acid ;  it 
has  [a]|)  —  6'8^,  and  gives  a  crystalline  brudne 
salt  Gi»HasOi^7Pt,4CttHai04N„14H,0,  m.p. 
174*»-175*»  (decomp,).  M.  A.  W. 

ADHESIVBS,  as  distinguished  from  cements, 
may  be  defined  to  be  substances  or  preparations 
of  a  gummy  or  gelatinous  character  used  for 
the  purpose  of  joining  together  or  effecting  the 
mutual  adhesion  of  the  surfaces  of  bodies.  They 
are  usually  substances  which  (1)  soften  in  water, 
e,g.  gum  arable,  isinglass,  glue,  &c. ;  (2)  gela- 
tinise in  water  or  other  menstruum,  ana  harden 
either  by  the  evaporation  of  the  solvent  or  its 
absorption  by  tiie  cohering  surfaces,  e.g.  liquid 
glue,  gelatine  cUssolved  in  acetic  acid,  rubber 
or  guttapercha  in  benzene,  &c. ;  or  (3)  which 
soften  on  heating  and  congeal  on  cooling,  e,g. 
asphalt,  marineglue,  shellac,  Ac.  The  surfaces 
of  the  articles  to  be  joined  should  be  perfectly 
dean;  they  should  be  brouaht  into  mtimate 
contact,  and  as  little  of  the  a&esive  as  possible 
employed.  In  certain  cases  perfect  contact  jb 
ensured  by  heating  the  parts  to  be  joined  to  a 
temperature  such  that  the  adhesive  solidifies 
only  when  union  is  effected. 

Solutions  of  gum  arable,  or  of  dextrin,  or 
British  gum,  mixed  with  acetic  add,  are  fre- 
quently employed  in  the  case  of  j^ajper.  Flour 
or  starch  mijrod  with  water  containing  a  little 
alum  so  as  to  form  a  thick  cream,  which  is 
tiien  heated  to  boiling,  and  when  cokL  mixed 
with  ofl  of  doves,  thymol,  phenol,  or  salicylic 
add  so  as  to  preserve  it,  makes  an  effective 
adhesive.  A  transparent  paste  may  be  made 
by  the  use  of  rice  starch  instead  of  ordinary 
flour.  Occasionally  a  small  quantity  of  linseed 
oil  or  glycerol  is  added  in  the  case  of  labels 
exposed  to  moisture.  Or  the  labek  mav  be 
protected  from  damp  by  being  coated  with  a 
mixture  of  2  pts.  sheilao,  1  pt.  Dorax,  dissolved 
in  16  pts.  of  boiling  water.  An  alternative 
method  is  to  applv  a  coating  of  copal  varnish. 

A  stronc  adhesive  may  be  made  from 
shredded  geuttine,  swollen  in  water  containing 
25  p.c.  of  glacial  acetic  add  aad  applied  hot. 
The  mixture  should  be  kept  in  a  closely  corked 
phial.  Another  recipe :  Dissolve  60  pts.  borax 
m  420  pts.  water,  aad  480  pts.  dextnn  and  60 
pts.  glucose,  and  heat  carefuUy — ^not  above  90** 
— ^with  constant  stirring  until  the  whole  is  in 
solution;  replace  the  evaporated  water  and 
filter  throuch  flannel  (Hiscox). 
^  Wheat  flour  rich  in  proteins  ia  mixed  with 
concentrated  sulphite  liquors  and  evaporated  to 
a  suitable  consistency  (Robeson),  flour  and 
molasses  mixed  to  a  stiff  paste  or  stiff  flour  paste 
and  concentrated  sine  chloride  make  a  perma- 
nent cement.  Dry  casein  mixed  with  half  its 
weight  of  borax  and  a  sufiBdenoy  of  water  makes 


an  excellent  adhesive  for  broken  china  or 
earthenware.  Finely  powdered  casein  12  pts., 
fieah  daked  lime  60  pts.,  fine  sand  60  pts.,  and 
enough  water  to  mace  a  thick  mass  makes  a 
strong  cement  for  ffround  unions  standing  a 
moderate  heat.  Milk  casein  dissolved  in  alkali 
and  an  alkaline  silicate,  such  as  water-glass, 
and  mixed  with  a  solution  of  magnedum  or 
caldum  chloride,  also  constitutes  an  effective 
adhedve.  White  of  efg  made  into  a  pade 
with  slaked  ttme  used  mimediatd^  after  being 
made  up  is  a  very  tough  and  tenacious  adhedve. 
Linseed  oil  mixed  with  china  day,  or  lime,  or 
red  or  white  lead,  or  oxide  of  iron,  to  which 
powdered  glass  or  graphite  may  be  added 
adheres  strongly  when  set. 

Metallic  sunaoes  after  having  been  rubbed 
^H^th  an  alcoholic  solution  of  hyorochlorio  add 
mav  be  caused  to  adhere  by  means  of  a  mixture 
of  10  pts.  tragacanth' mucilage,  10  pts.  honey, 
and  1  pt.  flour  (Spon). 

A  marine  glue  may  be  used  by  dissolving 
10  pts.  caoutchouc  in  120  pts.  benzene,  and 
adding  the  solution  to  20  pts.  melted  as- 
phaltum,  the  mixture  being  poured  into  moulds 
to  consolidate.  In  order  to  use  it  the  glue  is 
soaked  in  boilmg  water  and  heated  over  a  flame 
until  liquid. 

As  a  leather  cement :  asphalt,  1  pt. ;  rosin, 
1  pt. ;  gutta-percha,  4  pts. ;  carbon  disulnhide, 
20  pts.  A  plain  rubber  cement  ia  maae  by 
dissolving  crude  rubber  in  carbon  disulphide  or 
benzene. 

Good  waterproofing  cements  axe :  (1)  rosin, 
1  pt. ;  wax,  1  pt. ;  powdered  stone,  2  pts.  (2) 
Shellac,  5  pts. ;  wax,  1  pt. ;  turpentine,  1  pt. ; 
chaUc,  8-l()  pts.  For  a  soft  air-tight  paste  for 
ground  glass  surfaces:  a  mixture  of  equal 
parts  of  wax  and  vaseline.  A  solution  of  i  pt. 
of  powdraed  shellac  in  10  pts.  of  ammonia 
water  makes  a  strong  cement  for  poroelain, 
glass,  and  metals  (not  copper). 

Plastic  cements,  as  distinguished  from 
adhedves  of  the  foregoing  nature,  are  used  in 
chemical  industry  to  secure  joints  and  make 
connections  of  a  more  or  less  temporary  character. 
Such  are  plaster  of  Paris  used  dther  alone  or 
mixed  with  asbestos ;  or  when  a  high  tempera- 
ture is  not  required,  mixed  with  shavings,  straw, 
hair,  cloth,  ic.  Hydraulic  cement  usiDd  alone 
or  mixed  with  asbestos  or  sand,  is  used  as  a  lute ; 
it  is  especially  resistant  to  add  vapours.  Ordinary 
clay  or  fire  day  mixed  with  linseed  oil  is  often 
employed  for  steam-joints.  A  mixture  of 
fire  day,  2  pts. ;  sulphur,  1  pt. ;  rosin,  1  pt., 
may  be  used  for  nitric  and  nydrochlorio  add 
vapours.  Mixtures  of  (1)  pitch,  8  pts. ;  rosin, 
6  pts. ;  wax,  1  pt. ;  plaster,  ^  pt. ;  or  (2) 
pitch,  8  pts. ;  rosin,  7  pts. ;  sulphur,  2  pts. ; 
stone  powder,  1  pt.,  may  be  used  to  unite  slate 
slabs  and  stoneware  for  engineering  and  chemical 
purposes.    8u  Lutbs. 

ADIOAN.  A  preparation  of  digitalis  (g.v.). 
ADIPIO  ACID  Buiane^a-Mietuhoxylio  add 
COaH(CH2)4CO,H.  Obtained  by  the  action  of 
nitric  acid  on  sebacic  acid,  or  on  tallow,  suet, 
and  other  fatty  bodies  (Arppe,  Z.  1865,  300; 
Laurent,  Ann.  Ghim.  Phys.  [2]  66,  166; 
Bromeis,  Annalen,  35,  105;  Mala^ti,  Ber. 
1879,  572).  It  is  present  in  beet-jmce  (IJpp- 
mann,  Ber.  1891,  3299),  and  may  be  obtained 
from  Russian  petroleum  by  distilling  the  fraction 


ADRENALINE. 


71 


eontaining  naphthalene  hydrooarbons  (Asokan, 
Ber.  1899,  1769).  It  may  be  prepaied  by 
the  zednctUm  of  mndo  acid  (Cmm-Brown, 
AnnaJen,  125,  19),  Bacchario  acid  (de  la  Motte, 
Ber.  1879, 1572),  wosaooharic  add  with  hydriodic 
acid  and  phosphoroa,  or  of  maoonio  acid  with 
■odinm  amalgam  (Maiqnaidt,  Ber.  1869,  385) ; 
by  heating  /B-iodopropionio  add  with  silver 
(Widioeniu,  Annalen,  149,  221) ;  by  the  deotro- 
lyas  of  the  potassium  salt  of  the  monoethyl 
ester  of  succinic  acid,  whereby  the  diethyl  ester 
of  adipic  add  is  produced  (Brown  and  Walker, 
Annalen,  261, 117);  by  oxidising  cydo-hexanone 
with  potassium  permanganate  in  the  presence 
of  sodium  carbonate  (Rosenlew,  Ber.  1906, 
2202 ;   BlAnnich  and  Hanou,  Ber.  1908,  575). 

Adipic  add  crystallises  in  monodinic  lamina>, 
mdta  at  149^,  and  sublimes  at  a  still  higher 
temperatme  (Wirz,  Annalen,  104,  257).  Gydo- 
pentaaone  is  produced  when  the  caldum  salt  is 
dirtillfld,  and  no  anhydride  is  obtained  by  the 
distillation  of  the  acid.  It  is  slightly  soluble 
in  water  at  the  ordinary  temperature,  and  has 
a  great  tendency  to  form  supersaturated  solu- 
tions (Dieterle  and  Hell,  Ber.  17,  2221) ;  readily 
sohihle  in  hot  alcohol  and  ether.  It  forms  salts 
with  most  metals  which  aregenerally  soluble  in 
water  and  oiystalliaable.  There  are  eight  iso- 
merides  of  adipic  acid,  all  of  which  have  been 
prepared. 

ADIPOCBRE  (from  adeps,  fat;  and  eera, 
wmx).  A  peooliar  waxy-looking  substance,  first 
ohservod  by  Fouroroy  m  1786,  when  the  bodies 
wen  vsmoved  from  the  Cimeiihre  des  InnocefU.i 
at  PMis.  a  large  number  of  coffins  had  been 
piled  together  and  had  so  remained  for  many 
yean ;  the  oorpses  in  many  of  these  were  con- 
verted into  a  saponaceous  white  substance. 
Foorcroy  placed  tms  substance,  together  with 
chofesterol  and  spermaceti,  in  a  separate  class 
termed  by  him  '  Adipooere.*  Qregoiy  (Annalen, 
1847,  01,  362),  observed  a  similar  substance  in 
tbe  caae  of  a  hog  whidi  had  died  of  an  iUness, 
and  had  been  buned  on  the  slope  of  a  mountain- 
sideL  The  substance  was  oompletdy  soluble  in 
aloohftl,  contained  no  glycerides,  and  consisted, 
aooofdiaff  to  Gregory,  of  about  25  p.c.  of  stearic 
add,  ana  about  76  p.c.  of  palmitic  and  oldo 
aoda  (these  three  aoidB  form  the  chief  consti- 
tueots  ai  lard).  The  absence  of  lime  was 
azplaiiied  by  Ghragory  as  due  to  tbe  solvent 
aeliaii  of  water  saturated  with  carbonic  add, 
which  continually  ran  over  the  carcase.  Groffory 
foO J  leoqgnjsed  that  the  &tty  adds  had  been 
fonbed  by  the  hydrolysis  of  the  fat,  water 
having  washed  away  all  the  glycerol  simul- 
taaeoaaly  prodnoed,  and  he  deariy  stated  his 
view  that  nom  oorpses  of  animals  all  nitrogenous 
and  earthy  constituents  oonld  be  washed  away, 
fatty  aooa  only  remaining  behind.  Ebert 
(Ber.  8,  775)  in  the  main  oon&ned  these  results 
in  the  fivamination  of  a  specimen  of  adipooere. 
On  aa^pomfying  with  potash,  abont  1  p.o. 
ammnnia  esoaped  and  an  insoluble  residue 
(about  6  p.c.)»  iwmisthug  of  lime,  &c.,  from 
tiaaoes,  remained.  A  mixture  of  potasdum 
saita  was  obtainadt  which  by  fractional  pre- 
dpitataon  with  maenednm  acetate  yielded 
mainl]^  palmitic  aoicL  The  last  fraction,  not 
Mweipitaliki  by  maanedum  acetate,  but  by 
lead  aoatate,  yielded  a  hydroxylated  acid,  the 
formula  of  which  is  given  as  CiyH,«0,.    This 


acid,  termed  by  Ebert  hydroxymaraaric  acid, 
melts  at  80°,  and  is  most  likely  1 :  10  hydroxy- 
stearic  acid  of  the  mdting-point  81°.  The 
ooourrence  of  this  acid  in  the  iMipooere  examined 
by  Ebert  Ib  very  likely,  as  he  could  not  detect 
any  oldo  acid ;  it  would  thus  af^pear*  that  in 
the  course  of  time  the  oldo  acid  had  been 
oxidised  to  1 :  10  hydroxystearic  acid.  The 
hard  waxy  character  of  adipooere  is  mainly 
due  to  the  presence  of  hydroxystearic  addl 
Schmdok  (CSiem.  Zeit.  1902,  H)  found  hi  the 
examination  of  three  specimens  of  adipooere 
the  following  results : — 

Melting-point    .     .     .     62*5°  C. 
Insoluble  fatty  acids    .     831  84  p.c. 

Ash 1*7  p.o. 

(containing  83*6  p.c.  CaO) 

Unsaponifiable  matter  16*7  p.c. 
Acid  value  .           .     .     197 
Neutraliuktion  value  of 

the  fatty  acids    .     .     203 
Iodine  value     ...     14 

Tarugi  (Gazz.  ohim.  ital.  34,  ii.  469)  also 
states  that  adipooere  consists  chiefly  of  palmitio 
acid. 

According  to  Ruttan  (Trans.  Roy.  Soc. 
Clanada,  1917  [iii.]  10,  169)  the  two  isomeric 
monohydroxysteanc  acids  derived  from  oldo 
acid  are  invariably  present,  and  the  disappear- 
ance of  oleic  acid  marks  the  final  change  m  the 
formation  of  mature  adipooere  (r/.  Ruttan  and 
Marshall,  Proc.  Amer.  Boo.  Biol.  Chem.  1915). 

The  formation  of  adipooere  from  animal 
matter  had  been  studied  oy  Kratter  in  glaAB 
vesselB  filled  with  water.  Kntter's  opinion  that 
adipooere  originates  from  the  albuminoids  must, 
however,  be  rejected  as  erroneous,  for  there  can 
be  no  doubt  but  that  the  free  fatty  acids  are 
formed  by  the  hydrolysis  of  the  body  fat. 
All  the  decomposition  products  of  the  albumi- 
noids and  the  glycerol  would  be  washed  away, 
and  the  fatty  acids  would  naturally  form  with 
the  lime  of  tne  bones,  lime  soap,  which  may  or 
may  not  be  further  hydrolysed  by  water,  to 
free  acid  and  lime,  according  to  the  conditions 
obtaining  in  the  •  decompodtion  of  the  body. 
Bacterial  and  enzymic  actions  play  a  quite 
secondary  part  in  the  production  of  adipooere. 

ADLUHI]IEC„H4iOi.N,  crystals,  m.p.  188°, 
occurs  in  Adlumia  cirrhosa  (Rann.)  with  adlumi- 
dine  C^qU^^O^^,  plates,  m.p.  234°,  protopine, 
and  /3-homooheliaonine  (Schlotterbeok  and 
Watkins,  Ph.  Ar.  1903,  6,  17). 

ADONIDDI.  A  digitalis-like  gluoodde  said 
to  be  extracted  from  the  root  of  Adonis  remoZw* 
or  false  hellebore,  v.  Digitalis. 

ADOHITOL.    See  Cabbohydbatbs. 

ADORDI.  Trade  name  for  a  mixture  of 
some  powder  (infusorial  earth,  starch,  &c.)  with 
paraformaldehyde.    Used  as  a  wound  dressing. 

ADRENALINE.  Adrenalinum  B,R,  Epine* 
phrine,  Suprarenin 

O.H,(OH),*CH(OH)*CH,NH-CH, 

The  U.8J*.  has  dried  suprarenal  gland,  Supntn- 
nahun  siccumf  but  not  the  active  prindple. 
A  *  chromogen,'  coloured  green  by  ferric  chloride 
and  rose-r^  by  iodine,  was  discovered  in  the 
suprarenal  medulla  by  Vulpian  (Compt.  rend. 
1856,  43,  663),  but  the  remarkable  rise  of  blood 
pressure  caused   by   intravenous  injection   of 


78 


ADRENALINE. 


saprarenal  gland  extxacts  waa  not  observed 
until  1894  (OUver  and  Schafer,  J.  Physiol.  1894, 
16,  i.).  iuter  nnmerona  attempta  the  active 
principle,  which  tnmed  out  to  be  also  the 
ohromogen,  waa  first  obtained  crystalline  by 
Takaxnine  (Eng.  Pat.  1467,  1901 ;  J;  Soc.  Ghem. 
liid.  20,  746),  and  almost  rimultaneoiialy  by 
Aldrich  (Amer.  J.  Physiol.  1901,  5,  467).  The 
oonstitiition  waa  next  established,  mamly  by 
Pauly  (Ber.  1903,  36,  2944;  1904,  37,  1388) 
and  by  Jowett  (Trans.  Ghem.  Soc.  1904,  86, 
192).  The  raoemio  substance  was  synthesised 
by  Stolz  (Ber.  1904,  37»  4149 ;  and  D.  R.  P. 
162814,  167300  of  Farbw.  Meister,  Lucius  und 
Bruning;  c/.  also  Dakin,  Proo.  Boy.  8oo.,  B. 
1906,  76,  491).  As  the  racemio  substance  was 
found  to  have  little  more  than  half  the  activity 
of  the  natural  laevo-vaciety,  its  resolution  was 
effected  by  Fl&cher  (Zeitsch.  physioL  Ghem.  1908, 
68, 681 ;  andD.  R.  P.  2^461  of  Farbw.  Meister, 
Lnoiua  und  Bruning).  The  synthetic  Z-base 
thus  obtained  is  idantioal  with  the  natural  active 
principle,  and  is  known  commercially  as  supra- 
renin. 

The  name  epinephrine  was  first  applied  by 
Abel  to  i\^-benzo^l  adrenaline,  but  later  to  the 
active  substance  itself,  and  it  is  under  this  name 
that  the  substance  is  referred  to  in  the  U.S.P., 
for  instance.  The  objection  to  adrenaline  is  that 
it  is  a  trade  name ;  dose  on  thirtv  other  trade 
names  have  been  in  use  for  the  su  ostance. 

PrepanUion  ofncUural  evbetance. — ^The  minced 
glands  (generally  of  oxen)  axe  extracted  with 
addulated  water  at  90^-100'* ;  the  extract  is 
evaporated  to  a  small  bulk,  it  may  then  be 
purified  with  neutral  lead  acetate,  and  it  is 
finally  precipitated  with  several  volumes  of 
ethyl  or  methyl  alcohoL  The  aloohoUc  filtrate, 
af  tor  ooncentntion  to  a  small  bulk,  is  precipi- 
tated with  excess  of  concentrated  ammonia,  when 
the  adrenaline  crystallises  in  sphaerites  on 
standing.  Oxidation  must  be  guarded  against 
as  far  as  possible,  by  boiling  with  zinc  diut,  or 
b^  extracting  with  water  containing  sulphur 
dioxide;  the  evaporation  is  conducted  in 
vacuo  in  a  carbon  dioxide  atmosphere  and  the 
precipitation  by  ammonia  takes  place  under  a 
uiyer  of  petrol  (Takamine,  Lc, ;  Aldrich,  Ix, ; 
von  F&rth,  Monatsh.  1903,  24,  261).  Abel 
(Ber.  1903,  36;  1839)  extracU  at  once  with  a 
3*6  p.a  alcoholic  solution  of  trichloracetic  add, 
which  e]iminat4Ht  further  purification,  and  seems 
to  give  a  good  yield.  Bertrand  (BuU.  Soc.  cfaim. 
1904,  [iit]  31,  1289)  extracts  with  96  p.a  alcohol 
contahiing  oxalic  add,  evaporates,  snakes  witii 
petrol,  aiul  purifies  with  lead  acetate. 

The  cmde  sandy  adrenaline  contains  inor- 
ganic matter,  and  may  be  purified  by  solution 
m  add  and  repreoipitation,  but  better  by 
utilising  the  solubility  of  the  oxalate  in  alcohol ; 
the  crude  base  is  ground  up  with  a  16  p.a 
solution  of  oxalic  add  in  86-90  p.o.  aloonol, 
which  leaves  inorganic  impurities  behind  (Abel, 
Paulv). 

0|fiiiA6fe«.^)atechol  is  condensed  with  mono- 
chloraoetio  add,  by  means  of  phosphorus 
oxyohloride,  and  the  resulting  chloracetocateohol 
(3 : 4-dihydroxy-«»-chloracetophenone) 

(OH),C,H,COGH,a 

is  suspended  in  alcohol  (60  cc.  for  100  grams, 
of  the  ketone) ;   200  cc.  of  a  40  p.c.  aqueous 


methyhunine  solution  are  added;   on  standing 
methylaminoaceto  catechol 

(OH)jC,Ht-GO-OH,-NH'CHg 

separates  out,  and  is  washed  with  water,  alcohol, 
and  ether.  The  ketone  is  then  reduced  to  the 
secondaiv  alcohol  by  aluminium  amalgam,  or 
dectrolyncaUy.  For  the  resolution  the  bitar- 
trate  is  extracted  with  methyl  alcohol;  d- 
adrenaline-d-tartrate  dissolves  and  {-adrenaline- 
(f-tartrate  remains  behind.  The  tf -adrenaline  so 
obtained  is  also  utilised^  for  it  may  be  raoemised 
by  heating  with  dilute  hydrochloric  add,  and 
converted  into  the  crystalline  racemic  hydro- 
chloride (D.  R.  P.  220366)i  which  can  then  again 
be  resolved. 

The  synthesiB  from  chloracetocateohol  appears 
to  be  the  only  one  of  practical  importance,  but 
various  others  have  been  described.  The 
methylene  ether  of  adrenaline  was  synthesised 
by  Barger  and  Jowett  (Trans.  Ghem.  Soc.  1906, 
87,  967)  from  piperonal,  but  could  not  be 
hydxolysed  to  adrenaline,  and  other  attempts  in 
this  direction  were  also  unfoccessful  (e/.  Pauly 
and  Neukam,  Ber.  1908,  41,  4161;  Baigor, 
Trans.  Chem.  Soc.  1908,  93,  2081 ;  Bottcher, 
Ber.  1909,  42,  263 ;  Pauly,  ibid.  1909,  42,  484 ; 
Mannioh,  Arch.  Pharm.  1910, 248, 127 ;  B.  R.  P. 
209609,  209610,  212206).  Another  adrenaline 
synthesis  referred  to  in  the  patent  literature, 
consists  in  methylating  the  primary  base 
corresponding  to  adrenaline^  namely  3:4-di- 
hydroxyphenylethanolamine.  This  substance, 
known  commercially  as  arierenol,  may  be 
obtained  (a)  by  the  reduction  of  amino-aoeto- 
catechol  (D.  B.  P.  166632);  and  (6)  by  the 
reduction  of  the  cyanhydrin  of  protooateohuic- 
aldehyde  with  sodium  amalgam  (B.  R.  P. 
193634).  The  latter  reaction  may  be  repre- 
sented thus  t 

(0H),G,H,-GH(0H)-GN+4H 

«:OH),G,H,-GH(OH)-GH,NH, 

Amino-acetocatechol  may  be  produced  (a) 
from  chloracetocatechol  (above) ;  (b)  from 
piperonal  or  methyl  vanillin,  via  •»-nitroaceto. 
catechol,  which  is  reduced  (D.  R.  P.  196814)  thus . 

(0H),GgH,G0'CH,-N0,+6H 

=(OH),G.H,-GO-CH,NH. 

(c)  by  hydrolysis  of  the  condensation  pioduota 
of  veratrole  with  hippuryl  chloride  (D.  R.  P. 
186698  and  189483) 

(MeO),G,H,CO-GH,NHGOG,H, 

->  (OH),C,H,-GO-CH,-NH, 

or  by  hydrdysis  of  the  similariv  constituted 
phthalimido-acetoveratrole  (D.  R.  P.  209962 
and  216640).  The  last-mentioned  four  patents 
are  of  Farbenfabriken  vorm.  F.  Bayer  &  Go., 
all  the  others  of  Farbw.  vorm.  Meister,  Lucius 
und  Bruning  (c/.  Friedl&nder,  viii.  1181-1190; 
ix.  1024- lOS).  The  most  recent  synthesis  is  a 
modification  of  some  earlier  ones. 

Diacetylprotocatechuic  aldehyde  I,  on  con- 
densation with  nitromethane  in  feebly  alkaline 
aqueous  solution  yields  jB-hydrory-iB-3 : 4-di- 
acetoxyphenvlnitroethane  (IL).  When  this  is 
mixed  with  the  calculated  quantity  of  formalde- 
hyde and  reduced  by  sine  andf  acetic  add, 
/3-hydroir^-/8-3  : 4-diaoetoxyphenyl  ethyl  methyl- 
amine  (III.)  is  formed,  from  which  adrenalme 
is  obtained  on  removal  of  the  acetyl  groups  : — 


ADRENALINE. 


79 


OAo 

OAo 

0" 

->    /\OAo 

CHO 

OH(OH)CH,NO, 

(L) 

f^-) 

OAo 

^    /^OAo 

CH(OH)CH,NHMe 

(m.) 

(N.  Nagai,  Jap.  Patfl.  32440,  32441,  1918). 

Pr^terties. — ^Natural  adrenaline,  when  pore, 
fonna  odlondeaB  aphaero-orysiala,  m.p.  211°- 
212^  [a]o  .630 ;  the  eolabiUty  in  water  at  20"* 
18  0-0288  p.0.,  and  It  ia  also  very  aliffht  in  moat 
oiganio  aolventa.  Baoemio  adnnaune  decom- 
poaea  at  230^.  Adrenaline  dissoivea  in  the 
oalciilated  quantity  of  mineral  acids,  or  even  in 
dightly  leaa ;  it  auo  disaolvea  in  caustic  alkalis. 
Its  ahief  ftii«wii«»Ai  oharaoteristio  ia  the  eaae 
with  which  it  undeigoea  oxidation  {see  colour 
reaotiona,  below).  S<3utions  with  a  alight  ezoeea 
of  add  axe  the  moat  stable;  tracea  of  iron 
aooelerate  oxidation  (Gunn  and  Harriaon, 
Phann.  J.  1908,  [>▼]>  26,  613). 

The  aalta  of  the  optically  aotiye  adrenalinea 
are  moatly  amorphoua  and  deUqnescent ;  the 
honUe  ia  aaid  to  be  more  atable  (D.  R.  P.  167317). 
The  chief  cryatalline  aalt  is  the  hUartraie  em- 
ployed in  tlie  reaolution  of  the  raoemio  baae. 
The  latter  yielda  a  crystalline  hydrochhride, 
m.p.  157''  (B.  B.  P.  202169),  and  a  crystalline 
ooBohie;  the  correaponding  optically  actiye 
aalta  are  amorphoua. 

Cckmr  rtadiofM.  Colorimetric  estimation. — 
There  are  three  kinda  of  colour  reactiona  for 
adrenaUne :  (1)  the  seneral  catechol  reaction 
with  ferric  chloride  ^imit  of  green  coloration 
1 :  30,000) ;  (2)  the  phoephotungstic  reaction  of 
Folin,  Cannon  and  Denia  (Joum.  biol.  Chem. 
1013»  13,  477 ;  c/.  Folin  and  Denis,  ibid.  1012, 
12,  239),  in  which  the  reaaent  givea  a  highly 
ooloured  blue  raduction  produot ;  (3)  a  reaction 
with  a  oonaiderable  number  of  niild  oxidising 
reagenta,  in  which  the  adrenaline  ia  converted 
into  apparently  one  and  the  aame  roae-red 
oxidation  produot.  For  the  colorimetric  eatima- 
tion  of  Dure  adrenaline  solutions  the  reaction  of 
Folin,  (Sumon  and  Denia  ia  the  moat  auitable, 
and  agreea  cloaely  with  phvaiological  measure- 
menta  (Seidell,  Joum.  bioL  Chem.  1913,  16, 
197;  Johanneaaohn,  Biochem.  Zeitachr.  1916, 
76,  377).  The  reagent  employed  ia  the  aame 
aa  for  the  estimation  of  uric  acid,  but  adrenaline 
ia  three  timea  aa  aenaitiye  ( Johannesaohn  givea 
the  ratio  2-98).  100  grama  sodium  tungstate 
are  disaolved  in  760  o.c.  of  water,  and  after  Mding 
80  aa  of  86  p.a  (ayrupy)  phoaphoric  acid,  the 
solution  is  boiled  gently  for  1^2  hours,  and 
then  made  up  to  1  litre ;  ^hr-zhf  °^'  adrenaline 
can  be  detected ;  limit  1 :  3,000,000.  The  blue 
colour  soon  fades.  Uric  add  aolutiona  are  uaed 
aaatandaida. 

For  the  eatimation  of  adrenaline  in  extraote 
of  the  gland  which  are  always  more  or  less 
Yellow  in  colour,  the  phosphotungatate  reagent 
Ib  leas  suitable  (Sddell,  ^c),  and  it  is  unsuitable 
for  mixtures  ox  adrenaline  with  cocaine,  novo- 


oaine^  ke.,  because  the  latter  baaea  are  ore- 
dpitated  by  the  reagent  (Johannessohn,  f.c.). 
In  these  caaea  a  reaction  of  Uie  third  type  aeema 
preferable  (3).  Sddell  shakes  10  ac.  of  gland 
extracts  containing  1 :  60,000  adrenaline,  for 
one  hour  with  6  mg.  of  powdered  manganese 
dioxide.  Altera,  and  matcnea  the  colour  with 
that  of  atandarda,  prepared  by  mixing,  in 
various  proportiona,  a  aolution  of  2  grama 
CoCl,*6H,0+l  ao.  concentrated  hydroonlorio 
add  in  100  ao.  water,  with  an  aurio  ohloride 
aolution  containing  0*1  gram  Aud.  in  100  0.0. 
water.  These  muturea  are  stanoardised  by 
comparison  with  a  1 :  100,000  aolution  of  pure 
adrenaline,  mixed  with  an  extract  of  denocated 
thyroid  gland  (which  baa  the  aame  yellow  colour 
as  a  Buprarenal  extract). 

For  mixtures  containing  cocaine,  &c., 
Johanneaaohn  employa  the  Fr&nkel-Allera  re- 
action (Biochem.  Zeitach.  1909,  18,  40),  which 
consists  in  addins  an  eautl  volume  of  0*001 
jy-potawainm  &«-iodate  and  a  few  drops  of  phos- 
phoric acid,  and  heatinc  nearlv  to  tne  boiling- 
point  ;  a  red  colour  is  obtained  with  adrenaline 
up  to  1 :  100,000  or  1 :  300,000.  Other  oxidising 
reagenta  giving  a  red  colour  are  aurio  chloride 
(Gautier,  Compt.  rend.  Soa  de  Biol.  1912,  73, 
664;  very  delicate),  potasaium  persulphate 
(Ewina,  J.  Phyaiol.  1910, 40, 317  ;  1 :  6,000,000), 
iodine,  mercuric  ohloride,  potaaaium  ferri- 
^anide,  bromine,  bleaching  powder,  oamio  add. 
For  a  detailed  criticism  of  the  quantitative 
application  of  these  reagenta,  set  Borbeig 
(Rkand,  Aroh.  Physiol.  1912, 27, 341),  also  Bayer 
(Biochem.  ZeitaclL  1909,  20,  178)  for  means 
of  making  them  more  sensitive  but  leaa  apedfic. 

Phynologieal  methods  of  eatimating  adrena- 
line are  more  reliable,  and  may  be  more  accurate 
than  the  colorimetric  onea.  The  blood  pressure 
of  a  cat,  with  brain  and  spinal  cord  destroyed, 
and  without  ansrsthetic,  reacts,  according  to 
Elliott  (J.  Physiol.  1912,  44,  374),  'with 
mechanicieJ  accuracy,'  and  permits  of  the 
estimation  of  the  adrenaline  content  of  a 
cat's  supra-renal  with  an  error  of  0*01  mg. 
(3-4  p.c.  of  the  total  amount  present).  Mode- 
ratdy  accurate  results  may  also  be  obtained 
with  frogs  (L&wen,  Arch.  exp.  Path.  Phann. 
1904,  61,  416;  Trendelenburg,  ibid.  1910,  63, 
161). 

Fresh  buUock'a  aupra-renala  may  contain  up 
to  0*26  p.c.  adrenaline;  the  dedccated  gland 
(U.S.P.),  correaponding  to  6  pta.  of  the  freah 

gland,  may  contain  about  1*6  p.c.  A  freah 
ullock'a  gland  diaaected  free  from  fat  weigha 
about  10-12  grama.  The  actual  yidd  in  manu- 
facture often  doea  not  exceed  0*1  p.a  from 
buUock'a  glands;  sheep,  and  eapedally  hogs, 
contain  less.  The  dried  secretion  of  the  paroud 
gland  of  Bufo  aguckf  a  Central  American  toad, 
contains  aa  much  as  6  p.a  of  adrenaline  (Abel 
and  Macht,  J.  Phann.  exp.  Ther.  1912,  3,  319). 
The  moat  important  physiologicdt  action  of 
adrenaline  ia  that  on  the  arteriolea,  oauaing 
constriction  and  rise  of  blood  pressure.  Intra- 
venously minute  doaea  (0'0003  mg.  per  kilo 
in  rabbita)  produce  a  distinct  efifect.  Applied 
to  a  mucous  aurfaoe,  it  causes  marked  local 
vaso-constriction  and  blanching ;  on  this 
property  depends  its  chief  use  as  a  hs^mostatio 
m  suigerv.  It  is  often  used  mixed  with  a  local 
anaBsthetic     like     cocaine.     Most     commercial 


80 


ADRENALINE. 


solutions  and  the  Liqwjf  adrenalini  hydro- 
Moticua  of  the  B.P.  contain  0*1  p.o.  adrenaline 
diMolyed  in  a  sliffht  exoees  of  acid  (€,g.  one-half 
eqnlTalent)  wMon  renders  them  more  stable 
than  solid  tablets  (according  to  Johannessohn, 
1.6. ;  Gnnn  and  Harrison,  Ix.).  Chloroform 
(B.P.)  or  other  preeerratiye  may  be  added,  and 
salt  to  make  the  solotion  isotonic  with  the  blood. 
For  sterilisation  by  heat,  see  Bowe  (Amer.  J. 
Pharm.  1914,  86,  14d).  Adrenaline  has  been 
recommended  (in  oral  doses  of  5-6  m^.  per 
24  hours)  for  sea-aiokness  (Revue  Sdentifique, 
1917).  The  physiological  activity  of  cf-adrena- 
line  is  about  ^  of  that  of  Z-adrenaline  (t,g, 
Cushny,  J.  Physiol.  1909,  88,  269 ;  Tiffeneau, 
Gompt.  rend.  1915,  161,  36),  and  hence  the 
raoemic  base  is  slishtly  more  than  half  as  active 
as  the  natural  vanety. 

Adrenaline  Svhaiiuiea. — Numerous  amines 
have  an  action  more  or  less  resembling  that  of 
adrenaline  (Baiger  and  Dale,  J.  Physiol.  1910, 
41,  19).  Three,  aU  closely  rdated  to  adrenaline 
in  structure,  have  been  recommended  as  sub- 
stitutes, but  have  not  found  wide  application. 
Racemio  '  artorenol,*  3  : 4-dihydroxyphenyl- 
ethanolamme  (OH)|0.H,*CH(OH)'GH,.NH.  {see 
above),  m.p.  191**  (hvdrochloride,  m.p.  141^),  is 
said  to  be  about  half  as  active  as  ^adrenaline. 
Homorenon,  w-ethylamino-3  :  4-dihydrozyaoeto- 
phenone  (OH).C«H,-GO-0HaNH-02Hfi  has  a 
crystalline  h3rdrochloride,  m.p.  260°,  and  a 
very  much  weaker  action  than  adrenaline. 
Ejnnine^  3 : 4-dihydrozyphenvlethylmethyl- 
amine  (OH),C.H,-CHt<;H,NHCH„  m.p.  188®- 
189''  (Pyman,  Trans.  Chem.  Soc.  1910,  97,  272), 
ifl  intermediate  in  action  between  the  two  former 
bases.    (For  Tyramine,  see  article  on  Eboot.) 

For  a  more  detailed  account  of  the  chemical 
and  physiolcMdoal  properties  of  adrenaline,  Me 
Barger,'The  Simpler  Natural  Bases,  Longmans, 
1914,  pp.  81-105.  O.  B. 

ADmENCAINE.    8u  EuDBBNiNi. 

ADSORPnOH  V.  Colloids. 

ADUROL.  Trade  name  for  a  haloid  sub- 
stitution product  of  hydroquinone,  used  as  a 
photograpiuc  developer. 

AERATED  or  MINERAL  WATERS. 

Originally  the  term  *  mineral  water '  was  used 
to  describe  natural  spring  waters  containing 
small  quantities  of  various  salts  in  solution,  and 
frequently  saturated  with  carbon  dioxide, 
hy<uogen  sulphide,  or  other  gases.  When  these 
waters  were  nrst  imitated  by  the  artificial  intro- 
duction of  oarbon  dioxide  into  dilute  saline 
liquids,  they  were  known  as  '  aSrated  waters,' 
to  distinguish  them  from  the  natural  products. 
At  the  present  time  the  two  terms  are  employed 
indiscriminately,  and  as  a  rule  the  whole  of  the 
products  of  the  manufacturer  of  adrated  waters 
are  popularly  known  as  *  mineral  waters.' 

Hanml  Mliienl  Watin.  In  every  quartei 
of  the  ^obe  natural  spring  waters  containing 
salts  with  medicinal  properties  are  common, 
though  fashion  has  made  some  more  celelnrated 
than  others.  Some  of  these  waters  {e.g.  Hunyadi 
Janoe)  contain  majpiesium  and  sodium  sulphate, 
and  have  an  aperient  action,  whilst  others  con- 
taininff  iron  {e,g.  Tunbridge  Wells  water)  are 
valued  as  tonics.  Others,  again,  like  the  waters 
of  Harrogate,  contain  sodium  sulphide  (0*02  p.o.), 
and  are  used  as  remedies  in  vanous  complaints. 

The  most  widely  consumed  natural  mineral 


waters  are  those  which  contain  only  a  small 
proportion  of  salts  and  a  laige  amount  of  carbon 
dioxide.  Typical  examples  of  these  are  Apol- 
linaris  water,  Selters  water,  and  St.  Gaulmier 
(French). 

The  table  of  analyses  (p.  50)  show  the  chief 
constituents  of  typical  natural  mineral  waters. 

Small  quantities  of  many  other  compounds 
are  also  present  in  all  these  waters,  but  the 
figures  given  above  represent  their  main  con- 
stituents. The  composition  of  all  natural 
mineral  waters  varies  from  time  to  time,  but 
they  preserve  their  general  characteristics. 

Arttflelal  MinenlWaten.  Special  mixtures 
of  salts  approximately  corresponding  in  com- 
position to  those  in  many  of  the  well-known 
medicinal  waters  are  now  sold,  with  directions 
for  preparing  solutions,  which,  when  aerated, 
shall  pz^uce  passable  imitations  of  the  natural 
products. 

Among  the  purely  artificial  mineral  waters 
mention  must  be  made  of  feZfoer  water,  which  is 
prepared  somewhat  upon  the  lines  of  the  natural 
Selters  water,  and  contains  sodium  carbonate, 
chloride,  and  sulphate,  and  sometimes  calcium 
and  magnesium  chlorides,  the  proportion  of  these 
ingredients  being  varied  to  suit  the  popular  taste 
of  the  district.  It  is  bottled  at  a  pressure  of 
about  120  lbs.,  cotresponding  to  about  45-55  lbs. 
in  the  bottle. 

Other  medicinal  artificial  mineral  waters 
include  soda-water,  potash- water,  lithia- water, 
and  magnesia- water.  Soda-water  was  an  official 
drug  in  the  London  Pharmaoopoeiikof  1836,  but 
was  not  introduced  into  the  British  Pharma- 
copouia  until  1867.  In  the  present  Pharma- 
copoeia (1898)  it  is  omitted,  tocher  with  the 
other  alkaline  waters.  There  is  thus  now  no 
standard  for  soda-water,  and  since  the  M. 
standard  of  30  grains  of  sodium  bicarbonate  to 
the  pint  is  sometimes  found  too  alkaline  to  be 
palatable,  a  large  propcrtion  of  the  soda  water 

rn  the  market  contains  much  less  than  the 
specified  proportion  of  alkali 

Methods  of  A9rating, — ^The  prooeas  of  im- 
pregnating water  with  oarbon  dioxide  under 
pressure  diates  back  to  the  middle  of  the  18th 
century,  one  of  the  eariieet  inventors  of  ttppft- 
ratus  for  the  purpose  being  the  ]>nke  de  CSiallons 
in  France.  In  this  country  the  artificial 
*  aeration '  of  water  was  suflg^Bated  by  Beirfey 
in  1767,  and  in  1772  Priesu^  constructed  an 
apparatus  somewhat  on  the  principle  of  the 
modem  Kipps'  gas  generator.  A  similar  ap> 
pazatus  was  devised  about  the  same  time  by 
Bergman,  and  waa  extensively  used  throughout 
SwMlen. 

The  earlieat  processes  of  bottUng  afirated 
waters  made  use  of  what  is  known  as  the 
'  Geneva '  or  semi-eontinuous  process,  in  which 
the  carbon  dioxide,  after  beins  generated  from 
chalk  and  acid,  was  forced  unaer  pressure  with 
water  into  a  cylinder,  whence  it  could  be  drawn 
off  into  the  bottles.  This  process,  which  is  still 
employed  in  modified  forms,  is  useful  when  a 
relatively  small  amount  of  liquid  is  to 'be  im- 
pregnated, but  has  the  drawbacks  of  requiring 
the  work  to  be  interrupted  to  recharge  the 
cylinder,  and  of  bottling  the  liquid  at  lower 
pressures  than  are  often  required.  Hence  in 
moat  mineral  -  water  factories  the  continuous 
process  is  employed.  Although  numerous  patents 


AgRATGD  OR  MINERAL  WATERS. 


Ptanaru.  Saline  CossTnuBSTs  o 

W   HlSBttiL    VVATEHS-PiBTS 

PER    10,000. 

SODTM 

il 

n 

n 

Is 

|i 

I 

1 

i 

II 

H 

Jll 

AnthoritT 

ApoUinarii . 

12ti7 

4-66 

3-00 

trace 

- 

~ 

4'42 

- 

OSS 

0-20 

t!" 

Bi«lio£f 
-andUohr 

JUM 

7-96 

13-08 

1&9-10 

— 

— 

0-85 

— 

160-iO 

9-33 

0-04 

— 

Kn»pp 

0-04 

74?1 

2'2S 

_ 

032 

_ 

210 

_ 

7'74 

0-M 

1026  at 

Kutner. 

Bauer,  and 

Struco 

Selten   .     . 

8-01 

2261 

— 

0'47 

OSl 

2-60 

~ 

2-43 

- 

1087  at 
lO'C. 

Strnyo 

W^Cdei.: 

4h-h;i 

n:u 

2'91 

3-n? 

3.:h) 

4-34 

tni™ 

608 

(M'^ie 

I -46 

— 

~ 

'■"i  - 

200 

leratinj  machinery  hnv 
type  of  motbine  whic 
nan   ia   still   the    one   i 


been  taken 

originated   with    Brami 
general  use. 
In  Bramah' 

Kierated  in  a  leaden  or  lead-lined  generator 
m  eiilphurio  acid  and  a  carbonate,  and  paaeee 
into  a  gasometer  consistini;  oF  an  inverted  copper 
bell  in  a  tank  of  water.  Tbenoe,  after  expanding, 
it  it  pumped,  aimultaneoualy  with  water',  into  a 


condenMr  or  );lobe,  wherr  the  u-ater  is  linelj 
divided  and  saturated  with  the  gM  under  a 
presaure  indicated  upon  a  gauge.  Trom  thie  it 
passes  into  the  bottling  port  of  the  machine, 
where  ench  bottle,  placed  by  hand  in  poaitJon, 
receives  a  mensured  quantity  of  coiioentrated 
sodium  carbonate  solution  or  of  sweetened  symp 
and  is  filled  up  with  the  water  charged  with 

A  '  blow-off'  valve  is  provided  so  that  the 


B-  Wattt  rewrvB. 


PLAM  or  A  SODA-WATEB  BfASnlACTORV. 

sr topply  from  weU  or  waterworki.  L.  Soda-waU-r  nulation  l<>Dk  ImmlilaEmlnenl  nt«n 


which  renulre  do  ajrup. 
le  tap  Mil  closed. 
U>  atiat  oD  plain  altered  w 


le  beveiac». 


D.  "pipBiiniJliraiiehe»«upt)l)inglUt*redw»l«»  to  lymp  M.  Tap  tc 

3lntl<jii  tank,  ana  loda-waWr  machine.  noQ-» 

FFP.  MlilMandiooliiigpansloriyTnps.  O. Condenser rootalnlngaeraledwi 
OGO.   Felt  OlterlDub*^,  ttamogh  which  «yrop  [•  leading  to  iKJttUng  machine! 

nsMd.  P-  Whitlna  bin. 

HHlTTank  In  eoropartmenM  tor    itorins  Utered  Q.  Whiting  "hoot  to  BSnerator. 


n.  SfTup  luDctloniand  plpetiupplylng 


It  bottling 
JJJ.  Bottling  nia> 
K.  EloIoUon  pan 

elthST  plain 


R.  Vltrfoleli 
^.  Qatnn    ' 


teeding  BOda<wi 


T.  Gen 

TJ.  Blon 

machine  with    V.  Sl«ai . — 

r  lods  o[  other    Z.  Steam  pipe  to  lyrap  boUsr  and    bottle-waihlni 


AERATED  OR  HTNBRAL  WATERS. 


»iz  may  be  oomjiltflalj  eipeUed  from  the  botUi 
nnd  in  Bome  typoa  ol  muialiiM  tliere  we  mean* 
for  Tctuming  the  exoest  of  gu  to  the  goaometer, 
though  this  u  not  altogether  advaDt^eous. 

Arrangtmenl  of  A}rparaliui,-~Tbe gBOfoai  mods 
of  airanging  the  aantting  apparatus  in  the  fac- 
tory ii  anown  in  the  aooompanying  figure  {p.  61 ). 
^[Ike  eenerator,  t,  ia  now  frequeotlj  replaced 
by  oylinden  of  liqnefied  oarbon  dioxide,  which 
are  <x>miect«d  with  the  gaaometer.  The  soda- 
water  machine,  properly  bo  called,  baa  oc 
two  pumps  for  foromg  the  gaa  and  the  water 
into  the  condenaer,  o,  the  latter  being  made  of 
gun-metal  with  a  lining  of  pure  tb,  and  capable 
of  withstanding  a  preasure  three  or  four  times 
in  excesi  of  any  normally  employed.  In  small 
inatallationi  a  gaa-engine  usnally  takes  the  place 
of  a  steam-engine. 

Cordon  Dioxide  Stippli/. — The  general  u 
liquefied  carboo  dioxide  instead  of  that  generated 
from  acid  and  calcium  carbonate  is  the  ohief  im- 
raovement  on  the  original  method  of  bottling. 
The  new  metliod  is  leas  cxpendTe,  more  con- 
Tenient,  and  obviataa  the  difficulty  attending 
the  older  process  of  disposing  of  the  rteidue 
of  calcium  sulphate  from  the  generator. 

XJquefied  carbon  dioxide  collected  from  the 
fermenting  tuns  in  breweries  ia  sometime*  em- 
ployed, but  in  the  writer's  expenenoe  gas  from 
this  source  not  infrequently  contains  traces  of 
volatile  impuritiea,  which  impart  an  unpleasant 
flavour  to  soda-water. 

Pratitra  for  Atraiing, — Soda- water  and 
similar  unsweetened  mineral  waters  are  usually 
bottled  at  a  pressure  of  100-120  lbs.  to  the 
aquaie  inch  in  bottlee,  and  of  160  lbs.  in  siphons, 
irtiilst  tor  lemonade  and  the  like  a  pressnrv  of 
60-80  Iba.  is  employed.  In  the  case  of  goods 
intended  for  export  a  much  lower  pressure 
(usually  40--60  lbs.)  is  generally  considet«d  suffi- 
cient. The  figures  here  given  are  those  indicated 
upon  the  pressure  Rsuge  of  the  machine 
actual  pressure  in  the  closed  bottle  being  veiy 
much  less.  Thus  eiperimenta  made  by  the 
writer  have  shown  t^at  the  preasure  within 
bottles  ol  soda  water  bottled  at  a  machine 
prasure  of  100-120  lbs.  does  not  exceed  46-6S 
lbs.  An  excess  of  pressure  above  a  oertain 
limit  does  not  result  in  the  liquid  contai 

During  the  laat  few  years  automatio  bottling 
machines  have  been  introduced  into  all  tie 
leading  factories. 

The  principle  upon  which  these  machinea  is 
baaed  is  that  of  charging  an  upper  cylinder  with 
the  carbonated  liqmd,  and  filling  the  bottlee 
automatically  in  turn,  after  creating  a  counter- 
prcsaure.  UDdeT  tbeee  conditions  ttie  liquid 
flows  quietly  into  Uie  bottles,  and  there  is  do 
nnavoMable  loss  of  gas  or  syrup,  through  having 
to  remove  the  air  by  '  sniftmc. 

The  bottles  are  brought  beneath  the  filling 
cylinder  on  a  rotating  platfom,  and  each  in 
turn  lita  tightly  into  a  belt-mouth,  while  a 
valve  is  provided  for  the  escape  of  the  air 
expelled  by  the  carbon  dioxide.  This  air 
coUecls  above  the  liquid  in  the  feeding  cylinder, 
until,  when  a  certain  pressure  is  reached,  it  is 
automaticallv  dixcharged  throueh  a  valve  at 
the  top.  Ait«r  filling,  the  butllk  are  removed 
by  hand,  and  either  corked  by  hand  or  by 
machinery,  withoat  any  material  loss  of  pressuie. 


The  larger  niea  of  machines  arc  capable  of 
ling  from  100  to  140  doien  bottles  per  hour, 
id  the  saving  in  gas,  as  compared  with  the  old 
type  of  filUng  macbines,  is  about  20  p.c. 

LotB-prttiuTt  BoUUng. — HaoUnes  tor  auto- 
matically  filling  the  botUea  at  a  low  pnssare  are 
also  largely  used  in  mineral  water  factories,  and 
have  the  advantage  of  speed  over  mac* ' 
which  the  filling  is  effected  by  tile  a 


Bottle  nats  dd  whldi  botU^s  are  placed  tot 
flUlng:  O,  Bottle  nst  levari;  D,  Can,  whleb 
operatee  botUa  net  levers;  B,  Bollsn  on  valve 
bvidies ;  t.  Cam  tor  openfug  valvoe;  O,  Beleaaa 
valves  to  let  ilr  nut  nl  chimbeti ,  H,  Tsppat  for 
openlDE  release  valvea:  I,  Alt  chambers;  I, 
EetnilaUna  handles  loi  all  ohamben. 

bottles  are  suocesaivel^  Inserted  in  the  spaoa 
above  the  blocks  b,  whieb  are  depressed  in  ttun 
by  the  action  of  the  lever  c,  and  are  held  in 

C'tion,  with  an  air-ljght  joint  round  the  monthi, 
neans  of  a  spring.  The  aerated  water  enter* 
tfie  bottles  from  air-chambers  in  a  spiral  stream, 
leaving  a  space  in  the  centre,  through  which  the 
air  escapes,  and  passing  through  a  small  hole 
in  the  mouth-piece,  is  compressed  in  a  chamber, 
until  it  is  released  by  the  removal  of  the  botUe 
from  the  macliine.  When  the  revolution  is  com- 
plete escli  bottle  is  removed  by  hand,  and  corked 
or  stoppered  without  material  loss  of  piemin- 

By  the  use  of  either  this  system  or  Uie 
counter- pressure  system  there  is  no  wast«  of 
^Bs  or  liquid,  and  the  bottles  are  mote  perfectly 
charged  with  carbon  dioxide  at  a  prssann  of 


aSrated  or  mineral  waters. 


75-80  lbs.  than  was  possible  on  the  older  types 
of  machines,  in  whion  a  pressoTe  of  120  lbs.  or 
OTer  was  commonly  used,  and  the  air  was 
expelled  from  eaok  bottle  by  mpans  of  a 
'  snifting '  valre  controlled  by  hand. 

An  essential  of  good  bottling  is  that  all  air 
should  be  expelled  m>m  the  bottle,  sinoe  other- 
wise, air  being  only  slightly  soluble  as  compared 
with  carbon  dioxide,  the  liquid  will  rush  with 
almost  explosive  violence  from  the  bottle,  when 
opened,  but  will  become  flat  almost  immecUately . 
On  the  other  hand,  a  liquid  properly  saturated 
with  carbon  dioxide  and  froe  from  air  will 
continue  to  emit  minute  bubbles  of  gas  for  at 
least  five  minutes  after  it  leaves  the  bottle. 

Pre»9vrt  Gauges, — ^The  mode  of  measuring 
the  pressure  of  the  gas  varies  in  different 
countries.  Thus  in  England  and  the  United 
States  the  zero  mark  on  the  dial  of  the  pressure 
gauge  indicates  atmospheric  pressure,  and  the 
succeeding  figures  represent  the  number  of  lbs. 
in  exeesa  of  that  pressure.  In  Germany  the  dial 
is  graduated  in  atmospheric  pressures  in  excess 
of  the  normal  jpressure,  which  is  represented  by 
zero ;  whereas  m  France,  which  adopts  the  same 
mode  of  expression,  the  figure  1  represents  the 
normal  pressure,  and  the  figure  2  corresponds 
to  1  on  uie  German  scale  and  to  15  lbs.  on  the 
British  and  American  scales,  and  so  on. 

Sweetened  AffraUd  Drinks. — Lemonade,  ginger 
ale,  and  similar  sweetened  '  mineral  waters '  are 
prepared  in  the  same  way  as  soda  water.  A 
thick  syrup  is  made  from  sugar  and  saccharin 
and  water,  and  this  is  acidified  with  citric  or 
tartaric  acid  and  flavoured  with  an  essential 
oil,  which  is  conveniently  added  in  the  fprm  of 
an  alcoholic  solution  termed  a  *  soluble  essence.' 

The  syrups  are  filtered  through  the  filter  bags 
shown  at  c,  o,  o,  in  the  diacram,  into  tiieir 
respective  tanks,  h,  h,  h,  whence  they  are 
drawn  off  into  the  bottling  machine.  The  use 
of  saccharin  to  replace  part  of  the  sugar  in  the 
syrups  is  almost  univenal  in  this  country.  It 
has  the  advantages  of  reducing  the  cost  and  of 
acting  as  a  preservative,  whilst  its  disadvanta^ 
are  its  doyins  taste,  which  prevents  its  bemg 
used  in  more  wan  a  certain  proportion,  and  the 
want  of  fulness  on  the  palate  of  syrups  oontainins 
it.  The  latter  drawback  is  sometimes  remedied 
by  the  addition  of  glucose  syrup. 

Methods  of  detecting  and  identifying  sao- 
ehazin  are  described  by  Boucher  and  ^oungne, 
BulL  Soc  Ghim.  Belg.  1003,  17,  126 ;  Analyst, 
1003,  28,  241;  von  Bialer,  Farmaz.  J.  1004, 
1080;  Analyst,  1004,  20,  374;  Villiers,  Ann. 
Ghim.  AnaL  10O4,  0,  418 ;  Analyst,  1005,  30, 
21 ;  Ghaoe,  J.  Amer.  Ghem.  Soo.  1004, 26, 1627  ; 
Jorgensmi,  Analyst,  1000,  34,  106. 

Addition  of  Saponin, — ^The  popular  deman<X 
for  a  liqTud  which  shall  retain  a  frothv  head  for 
some  time  after  it  has  left  the  bottle  has  led 
to  the  manufacturers  frequently  adding  an 
extract  of  quHlaia  bark  or  other  preparation  of 
saponin,  sou  under  the  name  of  *  foam  heading,' 
Ac  Such  an  addition  is  more  necessary  in 
liquids  containing  saccharin  than  in  all-sugar 
bcrverages,  which  froth  more  with  the  carbon 
dioxide  According  to  the  results  of  experi- 
ments made  by  Lohmann  (Zeitsch.  offentl.  Ghem. 
1003,  0,  320;  Analyst,  1003,  28,  361),  saponin 
has  no  injurious  physiological  effects.  On  the 
other  hand,  according  to  Bouroet  and  Gheva- 


lier  (Pharm.  J.  1000,  70.  601)  eommeroial 
saponin  oontains  neutral  saponins  of  a  toxic 
nature. 

For  the  detection  of  saponin,  see  Brunner 
(Zeit.  Untersuch.  Nahr.  Genussm.  1002,  0, 1107), 
and  Riihle  {ibid,  1008,  16,  160 ;  J.  Ghem.  Soo. 
Ind.  1008, 27, 054),  Rosenthaler  (Zeit.  Untersuch. 
Nahr.  Genussm.  1013,  25,  154),  and  Gampos 
(Ann.  Ghim.  anaL  1014,  10,  280). 

Fermented , Beverages, — ^The  products  of  the 
mineral  water  factory  include  one  or  two 
beverages  in  which  the  aSration  is  the  result  of 
a  limited  fermentation. 

Ginger  beer,  which  is  the  type  of  this  class, 
is  prepared  by  adding  sugar  and  citric  acid  to 
a  dilute  infusion  of  ginger  root,  infecting  the 
liquid  with  a  small  quantity  of  a  suitable  yeast, 
bottling  it,  and  allowing  the  bottles  to  stand 
at  a  ]>roper  temperature  until  sufficient  fer- 
mentation has  taken  place. 

As  a  rule  the  fermented  liquid  contains  less 
than  1  p.c  of  absolute  alcohol,  but  occa- 
sionally in  very  hot  weather  the  fermentation 
may  proceed  much  further,  and  the  ginger  beer 
may  then  contain  as  much  as  5  or  6  p.c  of 
alcohol.  The  pressure  in  the  bottle  of  ginger 
beer  when  ready  for  consumption  averages  about 
16  lbs.  to  the  square  incn,  but  in  cases  of 
abnormal  fermentation  it  may  reach  100  lbs.  or 
more,  and  burst  the  bottle. 

OccasionaUy  objectionable  flavours  are  pro- 
duced by  infection  of  the  liquid  with  wild  yeasts 
or  bacteria,  just  as  in  the  case  of  ordinary 
beer. 

Other  drinks  of  this  description  are  hore- 
hound  beer  and  other  herb  beers.  Gertain  non- ' 
alcoholic  ales  on  the  market  are  prepared  by 
partial  fermentation  of  an  infusion  of  malt 
and  hops,  which  is  then  used  as  a  syrup,  and 
bottled  with  aerated  water  as  in  the  case  of 
lemonade. 

Stoppers  of  BoUtes, — ^The  screw  stopper  of 
vulcanite  or  stoneware  with  a  rubber  nng  to 
effect  a  tight  joint  is  now  universally  employed  ; 
for  the  glass  bail-stopper  (which  had  much  to 
recommend  it)  has  faUen  into  popular  disfavour, 
and  is  now  rarely  met  with,  except  in  out-of-the- 
way  districts. 

The  chief  objection  to  the  rubber-clad  stopper 
is  that  impurities  of  various  kinds  may  lodge 
beneath  the  rubber,  uid  unless  strict  clean- 
liness is  observed,  may  contaminate  the  con- 


tents of  the  next  bottle  into  which  it  is  intro 
duoed. 

The  Grown  oorking  svstem  has  in  recent 
vears  come  into  general  favour  for  closing 
bottles  of  mineral  water. 

A  cap  of  tinned  steel  or  aluminium,  with  a 
corrugated  edge,  is  pressed  down  by  a  machine 
into  a  special  ridge  on  the  neck  of  the  bottle, 
while  a  disc  of  prepared  sterilised  cork  covered 
with  parchment  paper,  which  is  fitted  into  the 
cap,  makes  an  air-tight  joint. 

It  is  essential  that  the  bottles  should  be  of 
an  exact  pattern,  since  the  slightest  variation 
from  the  standard  may  lead  to  faulty  bottling 
and  consequent  loss  of  gas. 

Badertdlogical  Conditions, — It  was  formerly 
believed  that  sterilisation  was  effected  bj* 
aerating  a  liquid  with  carbon  dioxide  under  a 
high  pressure.  In  1908,  however,  bacterioscopic 
exammations  were  made,  at  the  instigation  of 


84 


a£rated  or  mineral  waters. 


the  medical  ofBcer  for  the  City  of  London,  of  a 
laige  number  of  bottles  of  Boda-water,  and  it 
was  fomid  that  about  26  p.c.  oould  be  regarded 
a0  pure,  and  over  33  p.c.  as  impure,  the  remainder 
beinff  'fairly  pure  or  'not  pure.'  In  some 
of,  toe  worst  samples  the  numbers  of  micro- 
oi^anisms  per  1  c.c.  at  20^  were  uncountable, 
and  some  yielded  sediment  from  60  cc,  which 
when  cultivated  at  37°,  gave  innumerable 
colonies. 

As  the  result  of  this  investigation  a  meeting 
of  representative  mineral  water  manufacturers 
was  held,  and  it  was  decided  to  adopt  stringent 
measures  to  guard  against  bacterial  contamina- 
tion. 

In  addition  to  the  obvious  precautions  of 
having  a  pure  water  supply  and  observing  clean- 
liness in  every  stage  of  the  manufacture,  it  was 
agreed  to  discard  all  wooden  tanks  and  vessels 
(except  for  preliminary  soaking  to  remove  labels 
from  old  bottles),  to  rinse  the  bottles  with 
water  of  assured  purity  immediately  before 
filling,  and  to  use  for  tlus  purpose  a  metal  jet 
of  sufficient  force.  Wherever  practicable,  rubber 
rings  were  to  be  removed  from  the  stoppers,  or, 
failing  that,  were  to  be  immersed  in  a  solution 
of  calcium  bisulphite,  and  afterwards  rinsed  with 

Eure  water.  The  plant  was  also  to  be  inspected 
y  a  competent  authority. 

There  is  no  doubt  that  the  adoption  of  such 
precautions  has  had  the  result  of  raising  the 
standard  of  purity  of  soda-water  throughout  the 
country. 

In  considering  the  bacteriological  aspect  of 
the  question,  several  points  suggest  themselves. 
Thus  an  unfavourable  bacterioscopic  examina- 
tion of  one  or  two  samples  taken  casually  does 
not  necessarily  imply  faulty  manufacture,  for 
it  may  be  the  result  of  accidental  contamination 
of  the  stopper  by  the  hands  of  tiie  worker — 
against  wmch  there  is  no  complete  safeguard. 

Absolute  sterility  of  the  contents  of  the 
bottle  should  not  be  demanded,  and  it  is  un- 
reasonable to  require  a  greater  degree  of  purity 
than  that  of  the  average  water  supplv  of  London. 
Given  a  sufficient  degree  of  purity  of  the  original 
water,  which  is  essential,  efficient  inspection 
of  the  factorv  at  irregular  intervals  is  a  better 
protection  tnan  an  occasional  bacterioscopic 
examination.  When  such  examinations  are 
made  periodically,  they  should  be  made  under 
comparable  conditions,  t.e.  at  the  same  intervals 
after  bottling ;  otherwise  the  product  of  the 
cleaner  process  may  show  the  worse  results. 

Standiffds  are  notoriously  difficult  to  fix, 
but  making  allowance  for  the  various  chances 
of  contamination,  an  average  sample  of  soda 
water,  examined  one  day  after  bottling,  should 
not  yield  more  than  100  organisms  per  1  o.c.  at 
20*,  or  contain  sufficient  B.  colt  to  be  dis- 
coverable in  10  C.C. 

PreservcUives  in  Mineral  Waters, — ^The  pre- 
servatives most  likely  to  be  met  with  in  un- 
sweetened mineral  waters  are  sulphites  and 
bisulphites,  solutions  of  which  are  frequently 
used,  as  in  breweries,  for  cleansing  the  plant. 

A  small  proportion  of  salicylic  acid  is  often 
employed  to  prevent  fermentation  in  the  so- 
called  'fruit  S3rrups*  and  other  sweetened 
articles,  which  might  otherwise  ferment  and  be 
the  subject  of  an  excise  prosecution  for  con- 
taining alcohol. 


FermenkUums  occurring  in  Mineral  Watert, — 
Excessive  fermentation  of  ginger  beer  is  not 
uncommon  in  very  hot  weather,  and  the  writer 
has  met  with  samples  containing  as  much  as 
6  p.c.  of  absolute  alcohoL 

Occasionally  acetic  or  lactic  fermentation 
may  take  place,  and  spofl  a  batch  of  goods,  but 
this  seldom  happens  when  thorough  cleanliness 
is  observed. 

Atroublesome  form  of  fermentation,  commonly 
termed  the  *  mucoid'  fermentation,'  results  in 
the  conversion  of  the  contents  of  the  bottle  into 
a  thick  ropy  gelatinous  mass.  This  mav  be 
caused  by  sevcdral  micro-organisms,  such  as 
B,  gelatinosum  belcR  or  B.  viscostu  sacckari,  and 
is  more  liable  to  occur  when  beet  sugar  is  used 
for' the  syrup  than  when  cane  sugar  is  used. 
When  it  occurs  in  an  isolated  bottle,  insufficient 
cleansing  is  a  chief  factor  in  its  production. 

Mdatlic  Impurities. — ^Mineral  waters  not  in- 
frequently contain  traces  of  metallic  impurities, 
especially  iron,  tin,  and  lead,  derived  nom  the 
materials  used  or  from  some  part  of  the  plant. 

Iron  in  soda-water  is  objectionable  from  the 
fact  that,  when  the  beverage  is  added  to  a 
light-coloured  liquid,  such  as  whiskey,  con- 
taining a  trace  of  tannin,  an  unpleasant  dark 
colouration  is  produced. 

Traces  of  jtin  find  their  way  into  mineral 
waters  through  the  action  of  acid  syrups  upon 
the  tin  piping  leading  to  the  bottling  machines, 
whilst  lead  may  be  Serived  from  solder  on  the 
pipes.  No  such  soldering  should  be  permitted, 
and  thorough  flushing  of  tin  piping  with  water 
night  and  morning  effectually  prevents  con- 
tamination with  tin.  A  still  better  safeguard, 
which  lias  been  adopted  by  some  factories,  is 
to  replace  the  tin  pipe  by  glass  tubes  with 
rubber  connections. 

Alloys  of  lead  or  antimony  with  tin  are  more 
soluble  in  seltzer  water  than  either  metal 
separately  {su  Barilla,  Compt.  rend.  1911,  163, 
351). 

A  still  more  common  source  of  lead  is  the 
citric  or  tartaric  acid,  in  which  it  is  frequently 
present  as  a  manufacturing  impurity. 

Copper  is  not  a  common  impurity,  and,  when 
present,  is  usually  due  to  accidental*  contcMJt  of 
the  acid  syrup  with  the  metal. 

Arsenic  may  be  derived  from  glucose  used 
in  the  preparation  of  the  syrups,  or  from  the 
use  of  preparation.^  of  phosj^horic  acid  instead 
of  citric  or  tartaric  acid  for  acidifying  the  syrups. 

It  has  been  asserted  that  mineral  wateza 
take  up  traces  of  antimony  from  the  rubber 
rings  of  the  stopper  (which  contain  a  laige 
proportion  of  antimony  sulphide).  Experiments 
maae  by  the  writer,  however,  have  shown  that 
even  a  boiling  6  p.c.  solution  of  hydrochloric 
acid  does  not  dissolve  any  antimony  from  red 
rubber,  and  that  there  is  thus  no  risk  of  mineral 
waters  being  contaminated  in  this  way. 

(For  the  detection  of  traces  of  metallic  im- 
purities in  mineral  waters,  see  Budden  and 
I  lardy  (Detection  of  Lead,  Tin,  Copper,  and 
Iron),  Analyst,  1894,  19,  169;  Tatlock  and 
Thomson  (Lead  in  Cktric  and  Tartaric  Add), 
Analyst,  1908,  33,  173;  Lander  and  Winter 
(Poisonous  Metals),  Analyst,  1908,  33,  460: 
Report  of  Conjoint  Committee  on  Arsenic  Deter- 
mination, Analyst,  1902,  27,  48 ;  Report  of 
Royal  Commission  (Arsenic),  Analyst,  1904,  29, 


AFRICAN  MARIGOLD. 


85 


60 ;    Thorpe    (Electrolytio    Determination    of  I 
Arsenic),   Analyst,    1903,   28,   349);    Curtman 
and  Modier  (tin),  J.  Amer.  Chem  Soc.  1913,  35, 
867).  C.  A.  M. 

AR6U0.  (Verdigris  (?)  or  hydrated  basio 
carbonate  of  copper.)  The  name  given  by  the 
Romans  to  the  green  rust  product  on  copper 
and  bronze  by  the  united  action  of  the  oxygen 
water  and  carbon  dioxide  of  the  air.  It  was  con- 
sidered by  them  to  enhance  the  beauty  of  their 
bronze  statues.  The  same  rust  forms  on  brass, 
which  was,  however,  not  used  by  the  Romans. 

^BSGHYNTTE.  A  rare-earth  mineral  from 
Miask  in  the  Ilmen  Mountains,  southern  UraJs, 
described  by  Berzelius  in  1828,  and  named 
from  cdiTx^i^f  shame,  in  silusion  to  the  fact 
that  at  that  time  no  means  of  separating 
titanium  and  columbiiun  was  known  to  chemistfl. 
It  is  a  titano-columbate  (and  thorate)  of  cerium- 
metals,  calcium,  and  iron,  and  the  composition 
can  be  expressed  as  a  combination  of  a  meta- 
Golumbate  (C!a,Fe)Cb,0«  with  a  titanate  (and 
thorate)  Oe^Ti,Th)40,i.  The  mineral  forms 
orthorhombic  crystals  of  prismatic  habit.  It 
is  black  or  brownish,  with  a  pitchy  lustre,  and 
conchoidal  fracture ;  sp.Kr.  4-9-^*17 ;  hardness, 
5-6.  The  crystals  are  S>\md  with  red  felspar, 
biotite,  and  zircon  in  nepheUne-syenite  at 
Miask,  Urals.  The  mineral  trom  Hittero, 
Norway,  referred  to  this  species  by  W.  C. 
Brdgcer  in  1879,  has  since  been  named  blom- 
strandine  {q.v.).  L.  J.  S. 

ABCUU5TIN,  0CULIN  v.  Qluoosides  and 

HOBSB  CHESTNUT. 

AETHUSA  CYNAPIUU  (TJnn.).  'FooFs 
parsley'  or  the  *  lesser  hemlock,*  a  poisonous 
umbelliferous  herb.  When  dried  and  extracted 
with  alcohol,  yields  on  distillation  a  small 
quantity  of  an  essential  oil,  and  the  residue 
contains  a  resin,  a  crystalline  hydrocarbon 
petUeUriaeoniane  GasHft  (m.p.  74°)  and  a  crystal- 
line  alcohol   (m.p.    l4ff*'UV  i    [a]p=-36-7°) 

either  isomeric  with  phytosterol  CseH4|0, 
or  a  lower  homologucj  d-manniiol,  together 
with  a  small  quantity  of  a  volatile  a&aloid 
resembling  conine,  to  which  the  alleged  poisonous 
character  of  the  herb  may  be  due  (Power  and 
Tutin,  J.  Soc.  Chem.  Ind.  1905,  938). 

AFFINITY,      CHEMICAL      v.     Chemigal 

AFFIKITY. 

AFRICAN  ELEMI  v.  Oleo-resins. 
AFRICAN  GREEN  or  EMERALD  GREEN  r. 

Pigments.. 

AFRICAN  INCENSE  v.  Oleo-sesins. 

AFRICAN  MARIGOLD.  Taaetes  palula, 
Quercetagetin  was  isolated  from  the  flowers  of 
the  African  marigold,  Tctgetes  patula,  by  Latour 
and  Magnier  de  la  Source  (Bull.  Soc.  clmn.  1877, 
[ii.J  28,  337),  who  state  that  it  also  occurs  in 
other  varieties  of  the  same  plant.  In  appearance 
and  general  properties  it  is  described  as  resem- 
bling quercetin,  the  colouring  matter  of  quer- 
citron hark,  and  from  this  fact,  together  with 
its  oriffin,  the  name  quercetagetin  is  evidently 
derived.  On  the  other  hand,  according  to 
these  authors,  its  crystalline  form,  solubility 
in  60  p.c.  alcohol,  and  the  numbers  obtained  on 
analysis  indicated  that  it  was  distinct  from 
quercetin  C,7H,oOi|,  and  it  was  considered  to 
the  formula  Cs7H,20is  (anhydrous)  or 


v^i7H|aOig,4HJC)  (air-dried).    A  preliminary  re- 
examination 01  this  colouxing  matter  was  made 


by  Perkm  in  1902  (Chem.  Soc.  Proc.  18,  75), 
and  it  has  more  recently  been  studied  in  greater 
detail  by  the  same  author  (Chem.  Boo.  Trans. 
1913,  103,  209).  To  isolate  the  colouring 
matter,  which  is  largely  present  in  the  flowers 
as  glucoside,  a  concentrated  sicoholic  extract  is 
diluted  with  water  which  precipitates  a  viscous 
impurity,  and  this  is  removed  by  means  of 
ether.  The  clear  liquid  treated  when  boiling 
with  addition  of  a  little  hydrochloric  acia 
deposits  after  cooling  but  a  small  bulk  of  the 
colouring  matter,  and  repeated  extraction  of 
the  solution  with  ether  is  necessary  for  its 
economical  isolation.  The  crude  product  thus 
obtained  can  be  crystallised  from  dilute  alcohol, 
but  for  complete  purification  it  is  necessary  to 
prepare  the  acetyl  derivative,  and  after  re- 
crystaUisation  to  hydrolyse  this  in  the  usual 
manner. 

Querceiageiin  CibHioOs,  or  as  oiystaUised 
from  dilute  alcohol  Ci|HioOg,2H,0,  forms  pale 
yellow  glistening  needles  or^leaflets  resembling 
quercetm  in  appearance  and  melts  at  about 
318°.  Very  dilute  alkali  dissolves  it  with  a 
pure  yellow  colour,  which  by  air  oxidation 
becomes  olive,  and  finally  deep  brown,  but 
these  changes  are  not  so  marked  ^en  a  stronger 
alkali  (10  p.c.)  is  employed.  Alcoholic  ferric 
chloride  produces  an  olive-green  colouration, 
whereas  cold  alcoholic  lead  acetate  forms  an 
orange-red  precipitate  which  on  keeping  becomes 
yellower  and  finally  develops  a  green  tint.  On 
fusion  with  alkali  protoc€Uechuic  acid  is  obtained, 
together  with  a  phenolic  product  which,  how- 
ever, quickly  oxidises,  and  has  not  yet  been 
identified. 

Quercetaffctin  readily  yields  oxonium  salts 
with  mineral  acids,  and  of  these  the  stdphaU 
CisHioOgyH^SOi,  fine  orange-coloured  needles, 
has  been  described. 

Monopotassium  quercetageiin  CuKfiJL  sepa- 
rates as  an  orange-yellow  semi-CTystalune 
precipitate  when  potassium  acetate  is  added  to 
a  solution  of  quercetagetin  in  absolute  aloohol. 

By  acetylation  acetylquerceiageiin 

OijH,Os(C,H,0)e 

colourless  needles,  melting  at  209''-211°,  is  pro- 
duced and  on  alkylation  employing  alky]  iooide 
quercetagetin  pentamethyl  eiker  (jy^fiJfiCi)!^^^ 
pale  yellow  needles,  m.p.  161^-162°,  and  querce- 
tagetin  hexamethyl  ether  C^f,lifiJ,OCB.^)t*  colour- 
less needles,  m.p.  157^-158*',  can  be  prepared. 
Aceiylquerc^agettn  pentamethyl  ether 

CuH,0,(OCH,)jC,H,0, 

melts  161^-163°. 

Quercetagetin  hexaethy  ether  0i5H4O,(OEt)« 
m.p.  139^-14  r,  yields  oxonium  ttdts  with 
mineral  acids  in  the  presence  of  acetic  acid, 
the  sulphate  separating  in  orange  needled, 
whereas  the  crystals  of  the  hydrochloride 
possesses  a  somewhat  more  yellow  colour.  This 
behaviour  is  analogous  to  that  of  quercetiu 
pentamethyl  ether  (Watson,  Chem.  Soc.  Proc. 
1911,  27,  163). 

When  hydrolysed  with  alcoholic  potassium 
hydroxide  quercetagetin  hexaethyl  ether  gives 
protocalechuic  acid  diethyl  ether  and  querce- 
tagetol  tetraethyl  ether  CiJi^fit*  ^^^^  crystal- 
lises in  prismatic  needles,  OLp.  46''-48''.  The 
latter  yields  the  oxime  (;wH,gO«N,  m.p. 
93^-95°,    and    when     oxidised    with    alkaline 


80 


AFRICAN   MARIGOLD. 


permanganate  quereeiagetinie  acid,  m.p.  100°- 
102'',  is  produoecL 

The  produotion  of  queroetagetol  diethyl  ether 
to  which  the  oonstitation  (1)  is  assigned,  and 
protocatechuic  acid  diethyl  ether  (2) 

(1)  C,H(OEt),<^Q_^g^.Q£^ 

(2)    CO,H-C,H,(OEt), 

from  quercetagetin  hexaethyl  ether,  indicate 
that  quercetagetin  is  a  pentahydroxyflavonol 
isomeric  with  myiicetin  and  gossypetin.  Simi- 
larly to  tins  latter  colouring  matter  it  appears 
to  contain  a  tetrahydrozybenzene  nudeus,  and 
it  is  suggested  that  its  constitution  may  be 
represented  by  one  of  the  two  following  formul» : 

OH 


HO 


/ 


OH 


HO  ^" 


OH 


OH 
-<30H 

\co/^-^= 


Quercetagetin  readily  dves  mordanted  fabrics 
shades  of  a  generally  similar  character  to  those 
given  by  ouier  well-known  flavonol  colouring 
matters. 

Chfiymium.  Aluminiu'm,  Tin. 

Dull  olive-yellow.        JTellow-oraoge,        Brown. 

Iron, 
Brownish-black. 

A  trace  of  a  more  sparingly  soluble  colouring 
matter  is  present  in  the  flowers  and  represents 
about  1  p.c.  of  the  crude  quercetagetin  referred 
to  above.  It  crystallises  from  alcohol  in  some- 
what indefinite  sroups  of  minute  needles  and 
dissolves  in  alk^ine  solutions  with  an  orange 
colour  passing  to  green  on  dilution  with  water. 
Though  similar  in  appearance  to  rhamnetin 
(queroetin  monomethyf  ether)  it  does  not  contain 
a  methoxy  group. 

Dyeing  Propertiea  of  the  Flowers. — ^Employing 
mordanted  woollen  cloth,  the  following  shades 
are  produced : — 

Chromium.  Aluminium.  Tin. 

Ydlowish-  Pale  dull  Deep  yellow- 

brown,  yellow.  orange. 

Iron. 
Brownish-black. 

These  possess  a  somewhat  redder  character  than 
those  given  by  quercitron  bark,  and  are  similar 
to,  though  not  so  red  as  those  from  patent 
bfl^k.  As  quercetagetin  mainly  occurs  m  the 
flowers  as  glucoside,  their  tinctorial  effect  is 
evidently  due  to  this  Utter.  A.  G.  P. 

AFRIDOL.  Trade  name  for  the  sodium  salt 
of  hydrozymercury-o-toluio  acid. 

AGALITB.  A  name  used  in  the  paper-making 
trade  for  a  fibrous  variety  of  the  mineral  talc, 
a  hydrated  magnesium  silicate,  H,Mg,Si40it. 
It  is  white  with  a  tinge  of  green,  and  is  readily 
reduced  to  short,  fine  fibres.  It  is  obtained 
almost  exdusively  from  the  district  near 
Goavemeor,  in  St.  Lawrence  Co.,  New  York, 


about  70,000  tons,  valued  at  f  10  per  ton, 
being  produced  annually,  practically  all  of  it 
being  used  in  the  American  paper  trade.  It 
gives  weight  and  body,  and  produces  a  fine  gloss 
on  the  simace  of  the  paper.  L.  J.  S. 

AGALMATOUTE,  or  Pagodite.  A  soft  stone 
muoh  used  in  the  East,  especially  in  China,  for 
carving  small  statues  and  figures,  as  signified 
by  these  names.  At  least  throe  mineral  species 
appear  to  be  included  under  these  terms,  viz. 
pyrophyllite,  steatite,  and  pinite ;  but  it  is  to 
the  compact  forms  of  the  first  of  these  that  they 
are  perhaps  more  generally  applied.  In  addition 
to  their  compact  nature  and  low  degree  of 
hardness,  they  have  in  common  a  greasy  or 
soapy  feel :  in  colour  they  are  white,  greyish, 
greenish,  yellowish,  &o.,  often  with  mottling. 
rvroph^Uite  is  a  hydrated  aluminium  silioate, 
H^Ai^^ia;  steatite,  a  hydrated  magnceiom 
silicate,  b,Mg^i40 1, ;  and  pmite  is  an  alteration- 
product  consisting  lazgely  of  a  finely  scaly 
muscovite-mica,  a  hydrated  potassium  alu- 
minium silicate,  KJSjjfiifii^.  Beades  bdng 
employed  as  mateiial  for  carving,  these  minerals 
are  used  for  slate-pencils  (' pendl-stone ')  and 
for  tailor's  chalk  (*  French  ohuk '). 

Extensive  beds  of  compact  pyrophyllite  are 
quarried  in  the  Deep  River  region  m  North 
Carolina,  the  material  being  mainly  used  for 
making  slate-pencils.  At  Fukuye,  in  €ioto 
Island,  in  the  south  of  Japan,  a  compact  mineral 
allied  to  pyrophyllite  is  mined  under  the  name  of 
*  roseki '  (meaning  '  sreasy  stone  *  in  Japanese) ; 
it  is  crushed,  waiuiea,  and  prepared  very  much 
like  china-clay,  and  the  proauct  used  for  making 
fire-bricks,  and  to  a  smaller  extent  in  tjhe  manu- 
facture of  porcelain  and  paper.  This  material 
contains  SiO,  53-68,  Al^O,  32-36,  H,0  7-9  d.o. 

L.  J.  8. 

AGAR-AGAIt  Bengal  Isinglass.  Dried  sea- 
weed obtained  from  Singapore  and  other  places. 
It  is  obtained  from  vanous  red  algse,  including 
Odidivm  eomeum,  0.  cartilagineum,  Euchtuma 
87>ino9um,  and  OrtxcUaria  lichenoides,  which  grow 
along  the  coasts  of  Eastern  Asia  and  Mauya. 
The  cell- walls  of  these  seaweeds,  when  placed  in 
boiling  water,  change  into  jelly. 

It  occurs  in  snudl  transparent  strips  or  as 
a  powder,  and  dissolves  almost  entirely  m  water 
to  a  gelatinous,  tasteless,  and  inodorous  jelly.  ^ 
It  is  widely  used  as  a  nutritive  medium  for' 
the  cultivation  of  bacteria  and  funsi  Analysib 
of  fifteen  samples  of  agar  from  wi&ly  different 
sources  gave  tiie  following  results:  moisture, 
14-57-17*84  (average  16*57) ;  protein  (iVxb-25), 
1*53-3*26  (2-34);  nitrogen-free  extract,  72*72- 
78-21  (76-15) ;  ether  extract,  0*17-0-45  (0*30) ; 
crude  fibre,  0-39-1*50  (0*80);  ash,  3-08-5*68 
(3-85) ;  and  silica,  0-31-1*11  (average  0*68)  p.c. 
A  specially  purified  commercial  agar  for  bacterio- 
logical purposes  contained  :  moisture,  5*72  ; 
protein,  1*14;  nitrogen-free  extract,  80*25; 
ether  extract,  0*32;  crude  fibre,  0*45;  aah^ 
3*12  ;  silica,  0*29  p.c.  High  ash  or  silica  oon- 
tent  is  indicative  of  an  inferior  product.  An 
aqueous  solution  of  agar  is  acid  to  phenol- 

Ehthalein.  A  purified  agar  for  use  in  baotetio- 
»gical  work  where  a  gelatinising  a^^t  con- 
taining a  minimum  of  nutrients  is  desired,  may 
be  prepared  by  washing  agar  shreds  in  a  dilute 
solution  of  aoetio  add,  washing  out  the  aoid, 
dissolving  the  agar  to  a  5  p.o.  solution,  and 


AGATE. 


87 


poaring  the  hot  solution  slowly  into  a  large 
volume  of  95  p.o.  alcohol  or  acetone.  The  pre- 
cipitated agar  contains  considerably  less  nitrogen 
tnian  the  original  material.  Part  at  least  of 
the  nitrogen  compounds  present  in  agar  is 
available  as  nutriment  for  micro-organisms. 
The  setting  power  of  aqueous  solutions  of  agar 
is  not  destroyed  by  acid  or  alkali  between  the 
limitixu;  concentrations  of  4*5  p.o.  HCl  and 
5  p.c.  NaOH  ;  but  if  the  solution  be  heated  for 
fifteen  minutes  under  a  pressure  of  1  atmosphere, 
the  range  of  concentrations  within  which  solidi- 
fication occurs  is  reduced  to  &om  2  p.c.  HCl  to 
4'5  p.c.  NaOH.  The  gelatinising  power  is 
increased  by  addition  of  peptone  ana  slightly 
diminished  by  potassium  chloride  (Fellers,  J. 
Ind.  Eng.  Chem.  1016,  8,  1128;  J.  Soc.  Chem. 
Ind.  1917,  36,  43).    See  sJso  AuaM  and  Gums. 

AGAROBILLA.  The  seed-pods  of  CcBsalpina 
brevifrlia  (Baill.),  used  in  dyeing  and  tanning. 

AGATE.  A  native  form  of  silica  consisting 
mainly  of  chalcedony  {q.v,)  and  showing  a  more 
or  lees  concentric  arrangement  of  differently 
coloured  layers  or  bands.  The  layers  differ  not 
only  in  colour,  but  also  in  translucency,  porosity, 
and  crystalline  structure.  Some  layers  show 
the  minutely  fibrous  structure  of  typical  chalce- 
dony, others  are  more  dense  and  cryptocrystal- 
line,  while  some  may  consist  of  crystcdline 
quartz,  or  a^ain  of  t>paline  silica.  Some  of  the 
layers  contaming  larger  amounts  of  impurities 
and  colouring  matter  may  be  more  of  the 
character  of  jasper,  as  in  the  agate-jaspers  or 
jasp-agates.  The  material  has  been  deposited 
layer  upon  layer  from  solution  in  a  colloidal 
form,  and  suosequently  solidified  in  a  partly 
crystallised  condition.  The  deposition  has 
taken  place  as  a  lining  in  rock  cavities,  proceeding 
inwaros  from  the  margins  of  the  cavity.  In 
the  majority  of  cases  we  containing  rocK  is  a 
volcanic  rock  of  basic  composition  (i.e.  containing 
no  free  primary  quartz) ;  the  commonest  home 
of  the  H^^  being  the  steam  cavities  of  basaltic 
rocks.  The  movement  of  the  molten  lava  has 
caused  the  steam  cavities,  originally  spherical, 
to  be  drawn  out  into  almond  shapes  in  the 
direction  of  the  flow.  These  almond-shaped,  or 
amygdaloidal,  cavities  may  subsequently  become 
filled  with  secondary  mineral  matter  of  various 
kinds,  derived  from  the  primary  t«inftr«.]a  of  the 
rock  by  the  action  of  the  hot  vapours  and 
solutions  which  are  always  present  m  igneous 
maffmas.  Such  secondary  minerals — caloite  and 
vanons  zeolites — which  are  commonly  associated 
with  affates,  have  probably  been  formed  while 
the  rock  was  still  hot.  The  exact  conditions  of 
deposition  and  mode  of  formation  of  agates 
have,  however,  given  rise  to  much  discussion. 
With  the  weathering  of  such  an  amygdaloidal 
rock  the  agate-amygdales,  being  more  resistant, 
are  set  free,  and  may  be  easily  separated  from 
the  clayey  matrix,  or  they  are  washed  away  and 
broken  up  in  streams  and  rivers. 

The  artificial  deposition  of  gelatinous  silica 
in  forms  closely  resembling  t£oee  of  certain 
agates  has  been  effected  by  J.  I'Anson  and  E.  A. 
Pankhurst  (Ifinerak^ical  Magazine,  1882,  v. 
p.  34).  A  strong  acid  is  introduced  by  means  of 
a  pipette  into  a  solution  of  an  alkalme  silicate 
containing  a  certain  proportion  of  alkaline 
carbonate;  the  bubbles  of  carbon  dioxide  set 
free  become  coated  as  they  ascend  with  gela- 


tinous silica.  Agateliko  structures  have  also 
been  produced  by  Liesegang  by  the  diffusion 
of  one  saline  solution  into  another  in  a  gelatinous 
medium  (B.  E.  Lie^egan^,  Geologiscne  Diffu- 
sionen,  Dresden  and  Leipzig,  1913  ;  Die  Achate, 
Dresden  and  Leipzig,  1916). 

Many  trivial  varieties  of  agate  are  distin- 

fuished,  depending  on  the  patterns  presented 
y  the  several  layers  of  the  stone.  For  example, 
foTtification-af;ate,  eye-agate,  ring-agate,  riband- 
agate,  breociated-agate,  &c.  Onyx  is  an 
important  variety,  coffering  simply  in  that  the 
layers  are  plane,  thus  enabling  cameos  to  be 
engraved  in  relief  in  one  layer  with  a  background 
in  another  differently  coloured  layer.  A  typical 
onyx  with  alternately  white  and  black  layers  is 
however,  of  rare  occurrence  in  nature,  and  has 
usually  been  produced  by  artificial  colouring,  as 
explained  below.  In  camelian-onyx  the  layers 
are  red  and  white,  and  in  sardonyx  brown  and 
white.  Mo8s-a«rates,  mocha-stones,  dendrites, 
&o.,  are  chalcedonies  with  enclosures  of  various 
kinds. 

The  artificial  colouring  of  banded  chalcedony, 
or  the  intensification  of  the  coloration  of  agates, 
for  the  production  of  ornamental  objects  was 
probably  knovm  to  the  ancient  Romans,  and 
was  practised  by  the  Italian  cameo- workers  of 
the  Middle  Ages.  The  art  was  for  a  time  lost, 
and  again  came  into  use  at  Idar  in  Germany 
about  the  year  1820,  where  it  has  been  much 
developed  and  extensively  used.  Indeed,  practi- 
cally lul  the  fashioned  and  polished  stones  now 
placed  on  the  market  have  been  artificially 
treated. 

A  black  colour  is  obtained  by  soaking  the 
well-dried  stones  for  some  weeks  in  a  warm 
dilute  solution  of  sugar  or  honey,  or  in  olive-oil, 
and,  after  washing,  immersing  them  in  warm 
sulphuric  acid.  The  organic  matter  absorbed 
by  the  more  porous  layers  of  the  stone  is  thus 
carbonised,  in  case  the  black  colouration  is  too 
intense  it  may  be  softened  by  the  action  of 
nitr*c  acid.  A  rich  hfxnon  colour  has  recently 
been  produced  in  some  translucent  stones, 
siving  them  somewhat  the  appearance  of  garnet, 
by  soaking  them  in  brown  sugar-candy  and  then 
igniting.  A  red  colour  is  produced  by  saturating 
the  stone  with  a  solution  of  an  iron  salt  and 
igniting.  A  yellow  tint  inclining  to  lemon-yellow, 
is  imparted  by  digesting  the  stones  in  warm 
hydrochloric  acid.  Blue,  rano^ig  from  the 
deepest  indiffo  to  delicate  sky-blue,  is  produced 
by  soaking  tne  stones  first  in  a  solution  of  ferrous 
sulphate  and  afterwards  in  a  solution  of  potas- 
sium ferrocyanide.  Such  a  colour,  ana  also 
lemon-yellow,  is,  however,  unknown  amongst 
naturally  coloured  agates.  The  blue  coloured 
stones  have  often  been  passed  off  as  lapis-lazuli, 
but  they  are  readily  distinguished  from  this  by 
their  greater  degree  of  trimsluoency  and  hard- 
ness, and  the  absence  of  specks  of  iron-pyrites. 
Oreen  colours,  resembling  that  of.  the  natural 
chrysoprase,  have  been  produced  by  the  use  of 
salts  oi  chromium  and  nickel.  Finally,  various 
fancy  and  quite  unnatural  colours  have  been 
produced  by  simply  dyeing  the  stones  with 
aniUne  dyes;  these  colours  fade  on  exposure 
to  light,  and  finally  disappear.  On  the  history 
of  colouring  agates,  see  Ndggerath,  Die  Kunst, 
Onyxe  .  .  .  zu  firben,  Karsten's  Arohiv,  1848, 
xxiL  262 ;   and  on  the  methods  now  in  use  at 


^ 


AGATE. 


Idar,  O.  Dreher,  Das  Farben  des  Achats, 
Idar,  1913. 

The  agate-cutting  industry  has  long  been 
centred  at  Idar  and  Oborstein  on  the  Nahe, 
a  tributaiy  of  the  Rhine,  and  originally  the 
stones  were  obtained  locally  from  the  amygda- 
loidal  melaphyre  of  the  Galgenbeig.  But  since 
1827  enormous  quantities  have  been  imported 
from  Uruguay  and  the  neighbouring  Brazilian 
state  of  Rio  Qrande  do  Suf.  In  India,  agates 
and  other  varieties  of  chalcedony  are  abundant 
in  the  trap  rocks  of  the  Deccan  plateau,  and 
have  lonff  oeen  worked  by  the  native  lapidaries. 
The  well-known  *  Scotch  pebbles  *  are  prettily 
coloured  asates  from  Forfarshire,  Perthshire,  &o. 
Many  lociuitiee  in  America  and  Australia  might 
also  oe  cited. 

Besides  beins  used  for  a  great  variety  of 
small  omamentfu  objects,  agato  finds  technical 
applications  in  the  construction  of  pestles  and 
mortars,  burnishers  for  gold-workers  and  book- 
binders, smooth  stones  for  paper  and  card 
manufacturers,  rollers  for  ribbon  makers,  and 

fivot  supports  for  balances,  magnetic  needles,  &c. 
t  may  oe  remarked,  however,  that  an  *  sgate 
mortar '  need  not  necessarily  show  the  coloured 
bandinff  of  a  true  agate,  but  may  just  as  well 
be  cut  from  an  unhanded  chalcedony. 

On  the  agate  industry,  see  Q.  Lange,  Die 
Halbedelsteine  .  .  .  und  die  Geschichte  der 
Achatindustrie  (Kreuznach,  1868) ;  Upmann, 
Beit.  z.  Qesch.  d.  Graftsclu  Oberstein  (Mainz, 
1872).  On  Scotch  agates,  su  Guide  to  the 
Collection  of  Scottish  Agates,  Royal  Scottish 
Museum  (Edinburgh,  1899);  BL  F.  Heddle, 
The  Mineralogy  of  Scothmd  (Edinbuivh,  1901). 
On  agate  in  general,  see  M.  Bauer,  Edelstein- 
kunde,  2nd  edit.  (Leipzig,  1909),  and  Engl, 
transl..  Precious  Stones,  by  L.  J.  Spencer 
(London,  1Q04) ;  R.  Bratms,  transl.  by  L.  J. 
Spencer,  The  Mineral  Kingdom  (Esslin^en,  1912). 

AGAVE.  An  amaryllidaceous  genus  including 
several  species,  the  leaves  of  which  provide 
useful  fibres.  *  Pite,'  or  *  pita  hemp,*  mainly 
produced  in  Mexico,  is  obtamed  from  A.  amen- 
cana  (Linn.)  and  A.  mexkana  (Lam.).  It  is 
also  obtained  from  several  other  American 
species  of  Agave.  *  Sisal  hemp  '  is  derived  from 
A.  rigida  (&Iill.),  which  ffrows  m  Mexico,  Central 
America,  and  the  West  Indies. 

AGAVOSE.  An  inactive  sugar  Ci,H,,0,], 
reducing  alkaline  copper  tartrate,  and  yielding 
a  laevogyrate  susar  on  inversion ;  found  in 
Agave  americana  (Linn.),  grown  in  Mexico.  The 
young  flower  heads  are  used  in  the  preparation 
of  a  fermented  intoxicating  drink  termed 
*  pulque  '  (Michaud  and  Tristan,  J.  Amer.  Chem. 
Soc.  14,  548).  According  to  Stone  and  Lotz, 
J.  Amer.  Chem.  Soc.  17,  368,  this  sugar  is 
saccharose. 

AGMATINE  v,  Eboot. 

AGNIN  or  AGNOLIN.  Syn.  for  Adtpa  lance, 
or  purified  wool  fat. 

AGOBILIN.  Trade  name  for  a  mixture  of 
strontium  chelate  and  salicylate  with  diacetyl- 
phenolphthalein. 

AGONIADA  BARK.  The  bark  of  Plumiera 
land/olia  (Muell.),  used  in  Brazil  as  a  remedy 
for  intermittent  fever,  contains  a  bitter  crystal- 
line glucosidc,  aejoniadin  (Peckolt,  Arch.  Pharm. 
[2J  142,  40,  1870),  identical  with  the  plumieridt 


of  Boorsma  and  Merck,  obtained  from  Plumiera 
acutifolia  (Poir.) ;  it  is  probably  the  ineihyl  esier 
of  plumieridic  acid,  and  has  the  composition 
C^M^fiit  (^/*  Franchimont,  Rec.  trav.  chim. 
1898,  18,  334;  Proc.  K.  Akad.  Wetensoh. 
Amsterdam,  1900,  3,  35). 

AGROPTRUH  (B.P.)  or  TRTTICUM.  Hie 
dried  rhizome  of  Agropyron  repens  (Beauv.). 

AGROSTEHMA  SAPOTOXIN  v.  Gluoosides. 

AGURIN.  Trade  name  for  an  addition 
product  of  sodium  theobromine  and  sodium 
acetate. 

AGUTTAN.    Ozyquinoline  salicylic  acid. 

AICH  METAL.  An  alloy  patented  bv  J. 
Aich  in  I860  for  use  as  sheathing  for  ships. 
Contains  copper,  60  parts;  zinc,  38'5  parte; 
iron,  1 '5  parts. 

AILANTHUS  BARK.  The  inner  bark  of  A. 
exeelaa  (Roxb.)  and  A,  gJandvloaa  (Desf.) ;  it 
has  the  odour  and  taste  of  cinnamon ;  used  as 
a  tonic  in  dyspepsia  (Dymock,  Pharm.  J.  [3]  7, 
309).  An  Indian  name  of  the  former  is 
Mciharakk, 

AIROFORM.    Identical  with  airol  (q.v.). 

AIROGEN.    Identical  with  airol  (q.v,). 

AfttOL.  A  basic  bismuth-oxyiodide  gallate, 
analogous  to  'dermatol,'  a  basic  bismuth- 
gallate.  Is  a  greviBh-green  powder  without 
smell  or  taste,  soluble  in  caustic  soda  or  dilute 
mineral  acids.  Becomes  fed  on  exposure  to 
damp  air.  Has  been  used  clinically  as  a  sub- 
stitute for  iodoform  (t;.  Bismuth  and  loDoroKM). 

AJOWAN  OIL  V.  Oils,  Essential. 

AKAZGINE  V.  Nnx  Vomica. 

AK  MUDAR,  AKAN0A,  AKRA  RUI,  or 
ERUKKU  ERUKKAM.  The  bark  of  CaMn>pt'« 
gigantea  (Ait.)  apd  C.  procera  (Ait.).  An  im- 
portant Indiim  drug  (Dymock,  Pharm.  J.  [3] 
10,  122). 

AKOLA  V.  Ankool. 

AKRA  RUI  V.  Ak  Mudab. 

ALABANDITE.  Manganese  sulphide  (MnS) 
{v.  Manoanbsb). 

ALABASTER.  {AWdlre,  Fr. ;  AlabaHer,  Get.) 
A  massive,  cr3rstalline,  and  marble-like  variety 
of  the  mineral  gypsum  (CaS04,2H|0).  It  is 
found  in  Glamorganshire ;  at  Syston  in  Leices- 
tershire ;  at  TutDury,  near  Burton-on-Trent  in 
Staffordshire,  and  other  places  in  Britain.  A 
snow-white  alabaster  much  used  for  small 
ornamental  objects,  such  as  vases,  lamps,  stands 
of  timepieces,  &o.,  is  found  at  Volterra,  in 
Tuscany.  The  harder  varieiies  are  worked  with 
the  same  tools  as  marble,  smoothed  with  pumioo 
stone,  polished  with  a  mixture  of  chalk,  soap, 
and  nulk,  and  finiahed  by  friction  with  a 
flannel. 

The  softer  kinds  may  be  turned  or  fashioned 
with  rasping  tools,  fine  chisels,  or  small  files, 
smoothea  with  dried  shave  grass,  then  rubbed 
with  a  paste  of  putty  powder  or  finely  divided 
slaked  lime,  and  polished  by  washing  with  soap, 
water,  and  lime,  and  finally  with  powdered 
elutriated  French  chalk  or  talc. 

Alabaster  may  be  strained  by  heatinff  it  to 
about  00^  or  100",  and  then  dippins  it  into 
the  colouring  solution,  which  may  be  either 
metallic  solutions,  spirituous  tinctures  of  natural 
dyes,  or  coloured  oils  (Habild,  Wagner's  Jahr. 
28,  669). 

A  variety  of  alabaster  known  as  onyx  of 
Tecali,  from  Mexico,  takes  a  fine  polish ;    its 


ALANINE. 


89 


dolour  varies  from  milk-wtiite  to  pale-yellow  and 
pale-ffreen  (I.  29,  1264). 

ALACREATINE  v.  Creatcne. 

ALAITB.  Hydxatedvanadio oxide VsOsH.O 
foand  as  blood-red,  moBsy  growths  with  silky 
lustre  at  l^ya-Muyun  in  the  neighbourhood 
of  the  Alai'  Mountains  in  Feigana,  Russian 
Central  Asia.  The  uranium  and  vanadium 
depositB  mined  at  this  locality  consist  of  vana- 
dates of  uranium,  calcium,  and  copper,  occurring 
as  impregnations  in  a  coarse-grained  Devonian 
limestone  (K.  A.  NenadkeviS,  1909). 

T       J      g 

ALAMOSITE.  A  lead  silicate  PbSiO^  found 
near  Alamos,  Sonora^  Mexico;  analogous  to 
woUastonite  CaSiOg  in  form,  habit,  and  com- 
position. It  occurs  in  radiated  aggregates  of 
minnte  oolouileBS  transparent  fibres,  which  give 
a  SDOW-white  appearance  to  the  mass  (PalMshe 
sod  Merwin,  Amer.  J.  Sci.  1909,  27,  399;  J. 
Soc.  Chem.  Ind.  1909,  606). 

ALAN6IUH  LAMARCKn  v.  Ankool. 

ALANDIE,  a- Alanine,  a-aminopropumic  acid 
NHsOHMeOOtH,  oontittns  an  asymmetric  car- 
bon atom,  and  the  dextro,  laevo-,  and  racemic 
isamerides  are  known.  .-^-Alanine  is  one  of  the 
decomposition  products  of  a  large  number  of  pro- 
teids ;  together  with  a  glucoproteid  C7H14O4NS, 
it  ionns  51  p.c.  of  the  product  obtained  bv 
the  hydrolysis  of  legumin  of  peas  (Bleunard, 
Ann.  Chim.  Phys.  [5J  26,  47),  and  is  formed  to 
the  extent  of  21  p.c.  from  silk  fibroin  (Weyl, 
Ber.  21,  1529;  Fischer  and  Skita»  Zeitsch. 
physiol.  Chem.  33,  177 ;  Johnson,  J.  Amer. 
Cham.  Soc.  1916,  38,  1392-1398).  It  is  found 
in  yeast  proteid  (Neuberg,  Woch.  BrauereL 
1915,  32,  317-320),  and  in  'Zurdon's*  meat 
extnu^  (Zeitech.  physiol.  Chem.  1913,  83, 
458-467).  (For  the  *  methods  of  separating 
alanina  from  the  other  hydrolytic  products  (3 
tlie  proteid,  v.  art.  Proteins.)  r- Alanine  is 
pr^iued  svnthetically  by  the  action  of  hydro- 
chloric acid  on  the  aminonitrile  NH,*OHMe'CN, 
produced  by  the  interaction  of  aldehyde  ammonia 
and  hydrogen  cyanide  (Strecker,  Annalen,  75, 
29) ;  or,  together  with  a-aminopropionitrile 
hycbochloride,  when  ammonium  chloride,  potas- 
sium <^anide,  and  acetaldehyde  interact  in 
equimolecular  quantities  in  aqueous  solution 
(Zelinaky  and  Stadnikoff,  Ber.  41,  2061) ;  by 
reducing  a-nitrosopropionic  acid  with  tin  and 
hydrocUorio  acid  (Qutknecht,  Ber.  13,  1116) ; 
or  hydrolyBis  of  a-tiiazopropionio  acid  (Curtius, 
J.  pr.  Chem.  [2]  38,  396). 

Alanhift  crystallises  in  needles  or  sharp 
rhombto  prisms,  dissolves  in  4'6  parts  of  water 
at  17**,  or  in  500  parts  of  80  p.c.  cold  alcohol. 
For  solubility  and  optical  activity  of  r-a&zmne, 
■see  PeUini  and  Coppola  (Atti  R.  Accad.  Lincei, 
1914  [v.]  23,  1,  144-150,  from  Chem.  Zentr. 
1914,  1,  124).  Its  heat  of  combustion  is  389 
Cal.  and  heat  of  formation  135*2  Cal.  (Ber- 
thelot  and  AadrS,  Compt.  rend.  110,  884).  For 
-qaantitative  estimation  of  the- light  absorbed 
by  complex  salts  of  alanine,  see  Ley  and  Hegge 
•(Ber.  1915,  48,  70),  and  for  the  influence  of 
nenteal  salts  on  the  rotatory  power  of  alanine, 
sen  Pfeiffer  (Ber.  1915, 48, 1938).  The  resolution 
of  noemic  alanine  has  been  effected  through 
the  benzovl  derivative,  which  ia  separated  into 
</4HauaManine  (m.p.  147°-148<'  [ab+37-13° 
in  »i*r*Ji«>^  solution),  and  Jrhtnzoykianine  (m.p. 


150°-161°  (corr.),  [a]D-37-3°  in  alkaline  solu- 
tion), by  crystaUisation  of  the  brucine  salt,  and 
these  yield  on  hydrolysis  the  corresponding 
optically  active  alanines;  r-aJanine  decom- 
poses at  264''-268''  (Zelinsky  and  Stadnikoff, 
I.C.),  at  293°  (Fischer,  Ber.  32,  2451) ;  d-alanine 
has  [a]D+9*55^  in  hydrochloric  acid  solution; 
d-alanim  is  unohanffed  when  heated  with  strong 
hydrochloric  acid  (Abderhalden,  2ieitsch.  physiol. 
Chem.  1912,  82,  167-172).  Its  aqueous  solution 
is  decomposed  in  presence  of  sunlight  (Qanaasini, 
Qiom.  Farm.  Chim.  61,  439-444) ;  l-iUanine  de- 
composes at  297°  and  has  [alo'9'68°  in  hydro- 
chloric acid  solution,  r- Alanine  is  attacked  by 
fermenting  yeast  (Ehrlich,  BiochenL  Zeit.  63, 
379).  A  cultivation  of  Aspergillua  niger  in  an 
aqueous  solution  of  r-aJanine  destroys  about 
10  p.c.  of  the  dextrorotatory  constituent,  but 
PfnciUium  glavcwn  does  not  flourish  in  a  2  p.c. 
alanine  solution.  Resolution  has  been  effected 
also  by  means  of  <i-bromocamphorsulphonio 
acid  (Colombano  and  Sanna,  Att.  R.  Accad. 
Lincei,  1913,  [v.]  22,  11,  292-298 ;  Gazz.  ohiuL 
ital.  1914,  44,  1,  97-104). 

In  its  physiological  action,  (2-alanine  causes 
a  rapid  rise  in  the  urinary  nitrogen,  most  of  the 
extra  nitrogen  being  excreted  on  the  same  day  ; 
/-alanine  is  not  decomposed  quite  so  rapidly,  but 
none  of  it  is  excreted  unchanged  (Abderhalden 
and  Schittenhelm,  Zeitsch.  physiol.  Chem.  1907, 
51,  323  ;  compare,  however,  Sevene  and  Meyer 
(Amer.  J.  Phy8iol.l909, 25,214);  when  given  with 
lactic  acid  it  causes  an  increase  in  dextrose  eli- 
mination almost  equal  in  amount  to  the  theo- 
retical yield  (Dakin  and  Dudley,  J.  Biol.  Chem. 
1914,  17,  451).  After  administering  20  grams 
of  r-alanine,  4 '7  grams  of  the  jS-napnthalenesul- 
phonic  derivative  of  2-alanine  was  recovered  from 
the  urine  (Schittenhelm  and  KatzensteJn,  Chem. 
2^tr.  1906,  i.  1279).  When  (2-alanine  is  injected 
in  the  blocni-stream  it  is  rapidly  absorbed,  as 
very  little  can  be  detected  in  the  blood  or  urine 
after  a  lapse  of  twenty  minutes  (Abderhalden 
and  others,  Zeitsch.  physiol.  Chem.  1907,  53, 
113,  251,  326;  52,  507;  53,  148;  1913,  86, 
478  ;  and  J.  Biol.  Chem.  1915,  20,  539-554). 

The  importance  of  alanine  as  a  final  hydro- 
lytic product  of  many  proteid  substances,  has 
led  to  an  extensive  exammation  of  its  derivatives 
in  order  to  facilitate  its  detection  (Abderhalden 
and  Schmidt,  Zeitsch.  physiol.  Chem.  1913,  85, 
143-147 ;  Dakin  and  Dudley,  J.  Biol.  Chem. 
1913,  15,  127 ;  CheUe,  Ann.  Chim.  anal.  1914, 
19,  67)  and  estimation,  and  to  determine  the 
part  it  plays  in  the  building  up  of  the  proteid 
molecule.  A  short  account  of  the  more  im- 
portant of  these  derivatives  is  appended. 

The  c(ypper  salt  (C,HeO,N),Cu,HjO  forms 
bluish-violet  crystals  readily  soluble  in  water. 
The  nickel  saU  (CaU«0|N),Ni,4H,0  forms  blue 
cryHtaU,  these  become  anhydrous  at  108^-110^ 
and  dissolve  in  132  parts  of  water  (Orloff,  Chem. 
Zentr.  1897,  ii.  192 ;  Bruni  and  Formara,  Atti 
R.  Accad.  Lincei,  1904  [v.]  13,  ii.  26).  Complex 
salts  are  formed  with  heavy  metals,  e.g. 
Cr(C,HeO,N)aCr(C,H,0,N),OH-H,0(Tschuffaeff 
and  Serbin,  Compt.  rend.  1910,  151,  1361 ; 
Ley  and  Winkler,  Ber.  1912,  45,  372  ;  Ley  and 
Ficken,  Ber.  1912,  45,  377  ;  and  ibid.  1917,  50, 
1123),  and  with  chloride  of  tin,  e.g,  SuCi^ 
NHjjCHMcCOOH.  (Fichter,  Farber-Zeit.  1915, 
26,   274;   Chem.  Zeit.   38,  693).     Compounds 


ALANINE. 


fi 


are  formed  with  neutral  metallic  salts :   LiCl*  ' 
(NH,-CHMeCOOH)H,0 ;      Caa»(NH,CHMe- 
C00U)3U,0   (PfeifFer  and   Modelaki,  Zeitsoh. 

ihysiol.  Ghem.  1912,  86,  1-34;    Pfeiffer,  Ber. 

915,  48,  1938-1943).  The  eikyl  ester  has  b.p. 
48711  mm.  and  sp.gr.  0*9846  at  12*5'';  r- 
alaninamide,  m.p.  02?  (Franohimont  and  Fried- 
man, Froo.  R.  Akad.  Wetensoh.  Amsterdam, 
1905,  8,  475):  d-akminamide  has  m.p.  72" 
(corr.)  and  [a]D  +6^  in  5*2  p. a  aqueous  solu- 
tion; r-cuanykhhride  htf£rochloride  NH^Cl* 
GHMe'GOOl  melts  and  decomposes  at  110°; 

d-ahnykhhride  hydrochloride  has  [a]^^''+7-32o 

(Fischer,  Ber.  1905,  38,  606,  2914);  r- 
ahnineanhydride  {ditnethyldiketopiperazine 

NH<^^^5fe>NH  has  m.p.  282^  and  d- 
aianineanhydride  has  m.p.  297°  (corr.)  and 
[o]^'-28-8°  (Fischer,  Ber.  1905,  39,  453). 
d-V'Mdhylalanine  CH,CH(NHGH,)GOOH, 
m.p.  165°-166°  has  [a]^*+5-59°;    l-N-melhyl- 

alanine   [aj^  —5*92° ;     N-beiuylalaninej   m.p. 

about  270°  (Fischer  and  lipschitz,  Ber.  1915, 
48,  364 ;  ibid.  1916,  49,  1357).  AcetylaJanine 
NHAc'GHMe-0O,H     crystallises     in     rhombic 

Stes  a :  6  :  c=^0*7792  : 1 :  10983  ;  hld.  137° 
Jong,  Rec.  trav.  chim.  19,  259 ;  Fiscner  and 
Otto,  Ber.  36,  2106);  chloracetykdanine  ester 
GHjGlGONH-GHMeCOjEt  has  m.p.  48-5°-49-5° 
(corr.)  (Fiseher  and  Otto,  l,c.) ;  the  benzene- 
sidj^umie derivative SO,-Ph'NH'GHMeGO,H  has 
m.p.  126°  (Hedin,  Ber.  1890,  23,  3197) ;  benzyl- 
sv;^>honalanine  G«H,GH^0,NHGH(GH,)G06H 
has  m.p.  164°-165°  (Johnson,  J.  Amer.  Ghem. 
Soc.  1916,  38,  2135) ;  the  fi-naphihalenesulphonic 
derivcUive  Gifiifit^H  melts  and  decomposes 
at  220°  (Koenigs  and  Mylo,  Ber.  1908, 41, 4427) ; 
the  d'Camphoreulphonale.  of  alanine  GjH^OiN, 
C,oHi,OSO,H,H,0      has      m.p.       105°-110° 

l']^  +  ^^'^"^  (Golombano  and  Sanna,  Atti  R. 
Accad.  Lincei,  1913,  [v.]  22.  u,  234>237) ;  ethyl 
d-alanine'd-bromocamphorsulphoneUe  GO^Et* 
GHMe-NH„GioHi40BrSO,H,IH,0  becomes  an- 

hydrous  at  106°,  and  melts  at  192°,  f  o]^®*+ 67  -64° 

(Gazz.  chim.  ital.  44,  1,  97-104) ;  for  hippuryl- 
alanine  NHBzGH,G0NHGHMeC0,H,  m'.p. 
202°,  and  derivatives,  see  Gurtius  and  Lambotte, 
J.  pr.  Ghem.  1904,  [2]  70,  109 ;  phthalyUHanine 
G.H^  :  (CO),  :  NGHMeGO,H.  m.p.  164°.  and 
phth  aloylalanine  GO.HCeH^GONH  CHMe- 
GO,H,H,0.  m.p.  129°  (Andreasch,  Monatsh. 
1904,  25,  774) ;   palmUyU-alanine  GH.(GH,)i«' 

GONHGHMeGO,H,  m.p.  110°,  fa]^^  -5-98° 

(Aberhalden  and  Funk,  Zeitsch.  physiol.  Ghem. 
1910,  65,  61);  diethyldialaninquinone  G.H,0, 
(NH'GHMe*GO.£t),  forms  red  prisms,  m.p.  140° 
(corr.)  (Fischer  and  Schrader,  Ber.  1910, 43, 525) ; 
2  :  i-dinitrophenyt-dl-alanine,  m.p.  178°  (Abder- 
halden  and  Blumberg,  Zeitsch.  physiol.  Ghem. 
1910,  65,  318);  (f-ofomns  picrolonaU  (Abder- 
halden  and  WeU,  Zeitsch.  physiol.  Ghem.  1912, 
78,  150-155) ;  2'd'alanine-l'picrolonie  acid  has 
m.p.  about  145°  (decomposed);  l-d-aianine-l- 
piarohnie  acid,  m.p.  215°,  decomposed  at  217° 

Wj^*  +11 -08°   (Levene    and  Slyke,  J.    Biol. 

Ghem.  1912,  12,  127-1S9) ;  d-alaninepicrohnaie, 


m.p. 214° (decomposes) [al^+ 124°;  dlaJanine- 

picrolonate,  m.p.  216°  (decomposes) ;  benzyl- 
nydrogen-dt-alaninedithiocarboxylaie  GO*H' 

GHMe-NHGS,OH.Ph,  uLp.  136°  (Siegfried  and 
Weidenhaupt,  Zeitsch.  physiol.  Ghem.  1910,  70, 
152).    For  dirnethyUa^amnineoxalylglycine 

GO^eCHMeNH<X)-CONH-CH,-GO,Me 

m.p.  98*5°,  and  other  derivatives,  $ee  Meyeiingh 
(Rec.  trav.  chim.  1913,  32,  140-157). 

Among  the  polypeptides  prepared  by  Fischer, 
Abderhalaen,  and  others,  tnere  are  many  con- 
taining the  '  alanyl '  group  one  or  more  times, 
e,g.  r-alanylalanine  MHa*GHMe'GO*NH*GHMe- 
GOaH,  m.p.  276°  (corr.),  the  benzoyl  derivative 
m.p.  203°-204°,  the  ethyl  eater  m.p.  114°-116° ; 
dicUanylalanine  NH[GHMe-GO*NHl,GHMo- 

GOtH,  nLp.  219°  (corr.)  (Fischer  and  KautEsch, 
Ber.  1905,  38,  2375);    lalanyl^'alaninef  m.p. 

269°-270°     (corr.),    ra]^^''-68*5° ;     d-alanyl-l- 

alanine,  m.p.  275°-276°  (corr.),  [a]J^-f  68*94° ; 
(Fischer  and  Raske,  Ber.   1906, 39,  2893,  3981). 

NHCHMe*GO 
cydoalanylakmine     I  |       m.p.    282°- 

CO*CHMe*NH 

282*5°  (corr. )  (MaiUard,  Ann.  Ghim.  Phy  s.  1915,  [9] 
3,  73) ;  alanyl  glucosamine  anhydride  GtHi«0(N| 
turns  brown  at  246°-250°,  and  melts  at  269°- 
272°  (Weizmann  and  Hop  wood,  Proc.  Roy.  Soc. 
1913,  A  88,  45&-461);  ethylalanyl  mahylene- 
maUmaU  GO,£tGHMeNHGH :  G(GO|Et),, 
m.p.  206°-207° ;  alanyl-p-hydroxyphenyUthyl' 
amine  GnHigNiO,,  m.p.  116°  (Guggenheim, 
Biochem.  Zeitsch.  1913,  51, 369);  d-alanyl'd'ami' 
nobutyrylglycine  GH,GH(NH,)G0NHGH(GO- 
NHCH,G60H)GH,GH„     m.p.     214°     (coir.) 

[a]^^*+ 13*86    (Abderhalden,    Zeitsch.    physiol 

Ghem.  1912,  77,  371-478) ;  d-alanylglycyUeucine 

(GH,)jGHGH,CH(NHGOGH,NH,)GOOH 

m.p.  132°-133°  [a]^'- 13*82°  (Abderhalden  and 

Fodor,  ibid.  1912,  81,  21) ;  and  the  tetrapeptide 
glycyUyrosyl^lycyl-d-alanine  decomposing  at 225° 
I  (corr.)  is  probably  a  mixture  of  stereoisomerides 
of  the  tetrapeptide  isolated  from  silk  fibroin 
(Fischer,  Ber.  1908,  41,  2860;  c/.  Abderhalden 
and  Uirszowski,  Ber.  1908,  41,  2840).  For 
other  polypeptides  derived  from  alanine,  see 
Fischer  (Ber.  37,  2486;  4585;  38,  2375; 
2914  ;  Annalen,  340,  128,  152 ;  Ber.  39,  453  ; 
40,  943,  1754,  3717  ;  Annalen,  363,  136),  and 
Abderhalden  (Ber.  41,  2840,  2857 ;  42,  3394 ; 
Zeitsch.  physiol.  Ghem.  63,  401;  65,  417; 
77,471;  81,  21;  Biochem.  Zeitsch.  1913,  51,  369). 
/9-Alanine,  fi-aminopropionic  acid  H,N'GH|* 
GH|*GO,H,  prepared  by  treating  ;B-iodopropionio 
acid  with  ammonia  (Mulder,  Ber.  9,  1902 ; 
Abderhfdden  and  Fodor,  Zeitsch.  physiol.  Ghem. 
1913,  85, 114),  or  with  silver  nitrite  and  reducing 
the  resulting  nitro-  compound  with  tin  and 
hydrochlorio  acid  (Lewkowitsch,  J.  pr.  Ghem. 
[2]  20,  159) ;  by  heating  ethyl  acrylate  with 
alcoholic  ammonia  in  sealed  tubes  at  110° 
(Wander,  Gazz.  chim.  ital.  19,  437) ;  or  by  the 
action  of  potassium  hypobromite  on  an  alkaline 
solution  of  succinimide — this  is  the  best  method, 
and  gives  a  yield  of  60  p.o.  of  the  theoretical 
(Hoogeweif  and  van  Dovp»  Rec.  tray.  chim. 
10,  4 ;  Holm,  Arch.  Pharm.  242,  590).    It  can 


ALOOHOL. 


91 


be  noognifled  by  oonTenion  into  ethyl  Miylate 
( Abderhalden  and  Fodor,  Zeitac^  phyaiol.  CJhem. 
1913,  86,  117). 

fi-Mamnh  forms  prisniB  nLp.  196®  (Hcxmwerf 
and  Tan  Doip,  Le, ),  does  not  melt  at  22(>°  (I^usda, 
Monatah.  12,  242),  m.p.  206*''-207'*  (Lengfeld  and 
Stieglitz,  Amer.  Ghem.  J.  15,  604);  needlea, 
m.p.  200°  (Abderhalden  and  Fodor,  2.c) ;  the 
hyarochloride  of  the  mdkyl  ester  has  m.p. 
94''-95''  and  of  the  eOttd  eafer  m.p.  ess*".  The 
Cf>pper  eaU  Ga(CaH«NOJs,6HaO  has  the  pro- 
peiiieB  of  an  orainaiy  copper  sall^  and  not  those 
of  a  cnprammomum  oeriYatiye  (CaU^ari, 
Gazz.  ohim.  ital.  1906,  36,  ii.  63). 

^-Alanine  does  not  occur  naturally  in  the 
bod^;  when  administered  with  food  it  causes 
an  morease  in  the  urinaiy  nitroffen,  but  it  is 
apparently  changed  with  more  ££Qouliy  than 
a-u&nine,  as  the  incieased  nitrogen  excretion  is 
not  observed  until  the  second  day  (Abderhalden 
and  Schittenhelm,  Zeitsch.  physiol.  Ghem.  1907, 
61,  323).  M.  A.  W. 

ALAMT  CAMPHOR  v.  Gamfhob. 

ALAMT  ROOT.  The  root  of  InuJa  helenium 
is  said  to  contain  antiseptic  principles,  efficacious 
against  tuberculosis  bacilli.  By  distilling  the 
root  with  water,  hdenin^  aiatUic  acid,  and  tuantol 
(alant  camphor)  are  obtained.  AlarUic  add 
OisH^.O,  crystallises  from  alcohol  in  white 
crystals,  uld.  9P  ;  and  on  heating  it  forms  the 
anhifinde  G|(H,oOa.  Both  acid  and  anhydride 
are  insoL  in  water,  sol.  in  alcohol  or  fattjPoils ; 
form  sol.  salts  with  alke^.  AJantol  is  an 
aromatic  liquid,  b.p.  200**  (Marpmann,  Pharm. 
Zent.  8, 122 ;  J.  Soo.  Ghem.  Ind.  1887,  620). 

ALBARGIH.  Gelatose-silver :  a  colloidal 
preparation  of  silver. 

ALBASPIDIM  V.  Filix  mas. 

ALBERTITE.  A  jet-black  mineral  substance 
resembling  asphalt,  discovered  in  1849,  at  Hills- 
borough, Albert  co..  New  Brunswick.  Used  in 
the  United  States  for  the  production  of  oil  and 
coke.  The  jrield  per  ton  \b  said  to  be  100  gallons 
of  crude  oil,  and  14,600  cubic  feet  of  illumin- 
ating gas,  whilst  a  residue  of  good  coke  remains 
in  we  retorts.  Albertite  has  been  found  at 
Strathpeffer,  Ross-shire ;  it  contains  62  p.c.  vola- 
tile matter,  37  p.c.  fixed  carbon,  and  0*60  p.o. 
water.  Its  ultimate  composition  is  79*76  p.o. 
carbon,  8 '12  p.c.  hydrogen,  1*63  nitrogen,  and 
10*30  oxygen  (Morrison,  Blin.  Mag.  6,  101 ; 
Ghem.  Soc.  Abstr.  60,  311). 

ALBTTE  V.  FBL3PAB. 

ALBUM  GRACUM.  A  term  formerly  used 
for  the  excrement  of  dogs.  It  was  at  one  time 
supposed  to  have  medidnal  properties,  but  is 
now  used  only  for  tanning,  as  skins  treated 
with  it,  after  the  removal  of  uie  hair  and  previous 
to  tanning,  preserve  their  softness.  It  consists 
mainly  of  phosphate  of  lime.  Fowls*  dung  is 
said  by  tanners  to  answer  the  purpose  better. 

ALBUMINOIDS  and  ALBUMINS  v.  Proteiks. 

ALCOHOL  (Ethylic  or  Vinous)  G,H.O,  the 
active  principle  of  ordinary  intoxicating  liquors. 
Gontraiy  to  the  usual  statement,  alcohol  was 
unknown  to  the  Arabian  chemists.  The  process 
of  distillation  was  also  unknown  in  Asia.  The 
discovery  of  alcohol  probably  took  place  in 
Italv.  It  is  first  mentioned  in  an  Italian  work 
of  the  ninth  or  tenth  century  (Lippman). 

Ethyl  alcohol  occurs,  as  esters,  in  many 
plants,  and  in  various  liehena ;  and  is  formed  by 


<iy«taiKng  certain  plants  and  fruits  with  water, 
probably  by  hydrolysis  of  the  esters,  or  by  the 
action  of  moulds  and  bacteria  on  carbohydrates. 

Pfeujaniwi^ — Synthetically  from  its  ele- 
ments uius : — ^By  passing  an  eleotrio  arc  between 
carbon  pdes  ,in  an  atmosphere  of  hydrogen, 
acetylene  (G^H  J  is  produced,  which,  in  the  pre- 
sence of  nascent  hydrogen,  becomes  ethylene 
(G.H4).  Ethylene  by  protracted  shaking  with 
sulphuric  acid  is  converted  into  sulphovinic 
acid,  which,  being  distilled  in  presence  of  water, 
produces  alcohol. 

Alcohol  is,  for  practical  purposes,  usually 
prepared  by  dehydrating  the  jproducts  of  the 
distillation  of  fermented  liquids.  Up  to  1796 
the  strongest  spirit  known  contained  not  less 
than  6  p.c.  of  water.  Lowita  appears  to  have 
been  the  first  to  prepare  it  in  an  i4>proximately 
anhydrous  condition.  His  proceed  consisted  in 
first  in6reasing  the  strength  of  rectified  spirit  by 
adding  to  it  potassium  carbonate,  and  after 
decanting  from  this,  distilling  very  abwl^  in 
presence  of  a  further  quantity  of  dry  potassium 
carbonate.  Richter  used,  instead  of  potassium 
carbonate,  hot  calcium  chloride  (Grell*s  Ann. 
2,  211).    Drinkwater  first  digested  with  dry 

Sotassium  carbonate  for  twenty-four  hours; 
eoanted  the  strong  spirit  thus  produced, 
digested,  with  as  much  iresh-bumt  quicklime 
as  was  sufficient  to  absorb  the  whole  of  the 
alcohol,  and  afterwards  distilled  in  a  water- 
bath  at  a  temperature  of  82*2*'.  The  pro- 
duct of  this  distillation,  which  was  found  to 
have  a  specific  gravity  of  0*7046  at  16*6'',  was 
returned  to  the  retort,  and  a  fresh  (quantity 
of -dry  pulverised  quicklime  added  to  it,  after 
which  it  was  allowed  to  digest  for  a  week 
at  a  temperature  of  16*6°.  It  was  then  again 
slowly  distilled  and  the  specific  gravity  of  the 

Sroduct  found  to  be  0*7944  at  16*6^  This  was 
igested  at  a  temperature  of  64*4°  with  hot  quick- 
lime, and  distilled  out  of  contact  with  the  air  at 
a  temperature  of  81*1°  to  82*2°,  and  the  specific 
gravity  of  the  product,  which  was  taken  as  abso- 
lute iJcohol,  found  to  be  0*793811  at  16*6716*6°. 

Squibb  followed  the  process  of  Drinkwater, 
distilnng  in  a  partial  vacuum  of  380  to  630  mm. 
The  alcohol  thus  prepared  had  a  specific  gravity 
of  0*79360.  The  difference  between  this  specific 
gravity  and  that  found  by  Drinkwater  repre- 
sents one-tenth  p.c.  of  alcohol.  Mendel^fi's 
observations  (Pogg.  138,  103,  230)  practically 
confirm  those  of  Drinkwater  and  Fownes. 

Metallic  caldum,  free  from  calcium  nitride, 
may  be  used  to  dehydrate  alcohol.  The  calcium 
should  be  in  shavings,  washed  with  dry  carbon 
tetrachloride  to  remove  traces  of  petroleum,  in 
the  proportion  of  20  grams  of  cleaned  and  sieved 
shavings  to  every  li&e  of  alcohol.  In  order  to 
remove  ammonia  from  the  distillate  (due  to 
possible  traces  of  calcium  nitride)  a  few  centi- 
grams of  alizarin  are  dissolved  in  a  litre  of  the 
distilled  alcohol  together  with  0-6  gram  of  drv 
tartaric  add  dissolved  in  10  c.c.  of  the  alcohol. 
The  tartaric  acid  solution  is  slowly  added  to 
the  alcohol  coloured  by  the  alizarin  until  the 
reddish- blue  colour  changes  to  yellow,  when  the 
whole  is  asain  distilled. 

Manufaiaure. — ^The  first  process  in  the  manu- 
facture of  spirit  is  one  of  brewing,  and  in  general 
Erindplei  it  does  not  differ  irom  that  employed 
I  rnt^ng  boer.    Ths  brewer,  as  well  as  the 


n 


92 


ALCOHOL. 


distiller,  endeayours  to  treat  his  materials  in 
such  a  way  as  to  extract  from  them  the  greatest 
amount  of  fermentable  matters.  The  brewer  of 
beer»  however,  does  not  desire  to  oonyert  idl  the 
matter  he  extracts  into  spirit,  and  be  brews  at 
such  gravities  as  his  customers  require.  The 
distiller  desires  to  convert  as  much  as  possible 
of  the  matter  he  has  extracted  from  his  materials 
into  spirit ;  he  therefore  produces  a  wort  con- 
taining more  maltose  and  less  dextrinous  matter 
than  the  brewer  of  beer.  He  has  also  an  ad- 
vantage over  the  brewer  in  being.able  to  choose 
the  gravities  which  he  knows  by  experience  will 
produce  the  best  results.  It  has  been  found  that 
for  distillers'  purposes  it  is  advisable  to  keep  the 
specific  gravity  of  the  wort  when  set  for  fermen- 
tation below  lOiO.  The  principle  of  low  tem- 
peratures when  the  diastase  is  actins  in  the 
mash  tun  appears  to  be  fully  recognised,  60*  to 
63*^  being  generally  adopted,  and  it  is  understood 
that  the  higher  the  temperature  at  which  the 
worts  are  set  for  fermentation,  the  greater  is  the 
amount  of  fusel  oil  in  the  spirit.  The  distiller 
has,  therefore,  to  choose  the  lowest  temperature 
at  which  |t  healthy  fermentation  can  be  started, 
and  this  is  found  to  ranse  between  23"  and  25*. 
He  cannot  be  too  caref lu  as  to  the  purity  of  the 
yeast,  for  not  only  has  he  to  run  the  risk  of 
acetic  and  other  ferments  being  introduced  into 
the  wort,  involving  loss  of  alcohol,  but  to  provide 
against  the  presence  of  aldehyde,  which  ii 
objectionable  in  the-  spirit.  It  is  found  in 
practice  that  it  is  always  more  prone  to  appear 
in  hot  weather,  when  the  difficulty  of  keeping 
the  yeast  from  decomposition  is  greatest,  and 
as  yeast  always  contains  some  spint  in  a  dilute 
form  it  is  not  improbable  that  the  aldehyde  is  fre- 
quently a  product  of  the  oxidation  of  this  spirit. 
Acrolein(probablyderiyedfromgl^cerol)ammonia, 
and  sulphur  in  orsanic  combination  are  occasion- 
ally found  in  smafi  quantities  in  crude  spirit. 

The  materials  used  in  the  manutacture  of 
alcohol  in  the  United  Kingdom  are  chiefly  malt, 
maize,  rice,  sago,  tapioca,  barley,  rye,  oats,  sugar, 
and  molasses,  but  occasionally  dates  and  locust 
beans  have  oeen  employed.  At  the  present 
time  maize  constitutes  fuUy  75  p.c.  of  the  grain 
used.  In  Scotland  the  smaller  distillers  use 
malt  only,  and  the  spirit  they  produce  under 
the  name  of  Highlana,  Campbeltown,  or  Islay 
Whiskey,  Glenlivet,  Lochnagar,  &c.,  has  im- 
parted to  it  a  flavour  derivS  partly  from  the 
peat  ui^  in  drying  the  malt.  The  process  of 
manufacture  consists  in  distilling  the  fermented 
wort — then  called  wash — in  a  common  still,  col- 
lecting the  distillate,  which  is  weak  spirit  con- 
taminated with  fusel  oil,  and  is  called  *low 
wines,*  and  redistilluiff.  The  spirit  which  passes 
over  in  the  middle  m  the  redistillation  is  that 
which  is  used  for  consumption.  •  It  contains  from 
60*8  to  76*7  p.0.  of  alcohol  by  weight  (20  over- 
proof  to  45  overproof ),  but  is  generally  diluted 
by  the  addition  of  water  to  55*4  p.c.  of  alcohol 
by  weight  (11  overproof)  before  being  sent  into 
consumption  or  placed  in  bond.  Irish  whiskey 
differs  from  Scotch  chiefly  in  the  absence  of  peat 
flavour.  The  materials  used  in  its  manufacture 
are,  with  one  or  two  exceptions,  a  mixture  of 
malt  and  grain,  the  proportion  of  malt  beinff, 
however,  greater  than  in  Knglish  distilleries.  It 
is  generally  bonded  at  25  overproof  (64  p.c.  of 
alcohol  by  weight). 


We  have  hitherto  dealt  with  the  spirit  manu- 
factured in  *  Common  '  or  *  Pot '  stills,  or  m 
other  words  by  boiling  the  wash,  condensing  the 
steam  thus  produced,  reboiling  the  product  and 
reoondensing.  But  by  far  the  greater  quantity 
of  the  alcohol  of  commerce  is  produced  by 
the  Coffey  still,  in  which  the  alcoholic  vapour 
produced  is  deprived  of  water  as  the  process 
continues  until  a  spirit  is  formed  of  much 
greater  purity  than  that  manufactured  by  the 
old  method.  The  annexed  illustration  represents 
a  Coffey's  distilling  apparatus,  the  left-hand 
column  being  called  the  analyaer,  the  right 
hand  one  the  rectifier.  The  first  operation  is  to 
fill  both  columns  with  steanu  Tnis  is  accom- 
plished by  introducing  it  under  pressure  from 
the  boiler  at  o,  whence  it  ascends  within  the 
analyser,  passing  by  the  pipe  m  into  the  bottom 
of  the  rectifier.  When  a  proper  temperaturo 
has  been  attained,  the  wash  is  pumped  from 
the  wash  charger  by  a  pipe  which  enters  the 
top  of  the  rectifier.  This  pipe  is  only  shown 
sectionally  in  the  sketch  after  entering  the 
column,  out  it  is  oontinuous»  and  the  wash 
passes  slowly  through  it,  becoming  warmer^ 
owing  to  the  pipe  Ming  in  contact  with  the 
steam.  When  it  has  reached  the  bottom  of  thd 
rectifier  it  is  not  far  from  the  boiUng-point. 
It  will  be  seen  that  tiie  pipe  then  asoeims,  and 
finally  delivers  the  wash  into  the  top  of  the 
analyser.  The  lines  across  the  analyser  repre- 
sent plates  of  periorated  copper,  and  in  connec- 
tion witU  each  is  a  tube  which  projects  about  an 
inch  and  a  half  above  the  plate,  and  dips  into  a 
shallow  vessel  placed  on  that  next  beneath.  The 
wash  on  enterina;  falls  on  the  first  plate,  but  on 
reaching  a  depth  of  an  inch  and  a  half  passes  ^ 
through  the  tube  to  the  second  one.  In  the  ' 
mean  time  the  steam  produces  ebullition  in  the 
contents  of  the  plates,  and  carries  away  with  it 
the  alcoholic  vapour  through  the  steam  exit 
pipe,  so  that  by  the  time  the  wash  has  reached 
the  bottom  of  the  column  it  has  been  deprived 
of  its  alcohol.  The  alcoholic  vapour  passes  by 
the  pipe  m  into  the  bottom  of  the  rectifier,  which 
like  the  analyser  contains  plates  and  metal 
tubes,  and  where  a  process  of  gradual  cooling 
takes  place  by  the  action  of  the  pipe  carrying 
the  cold  wash.  Fusel  oil  vapour,  oondensins  at 
a  higher  temperature  than  alcohol,  is  the  first 
to  assume  the  liquid  form,  and  contaminated 
with  spirit  passes  into  the  hot  'feints*  re- 
ceiver. The  vapour  containing  alcohol  oon- 
tinues  to  ascend^  meeting  with  portions  that 
have  condensed,  and  aro  undeigoing  the  process 
of  rectification.  It  will  be  seen  that  the  upper 
part  of  the  apparatus  ia  marked  off  in  the  sketch 
as  finished-spirit  condenser.  It  is  so  called  be- 
cause all  that  condenses  within  its  area,  instead 
of  returning  towards  the  bottom  of  the  apparatus 
to  be  rectified,  passes  by  the  finished-spirit 
pipe  or  feints  pipe  into  the  receivers.  At  the 
top  of  the  apparatus  is  a  pipe  marked  '  alcoholic 
steam  exit,  which  carries  away  most  of  the 
aldehyde  as  well  as  spirit  vapour  which  under 
special  circumstances  may  not  have  been  con- 
densed before  reachinff  that  point. 

The  English  distillers  confine  themselves 
almost  exclusively  to  this  apparatus,  browins 
for  the  most  part  from  a  mixturo  of  ^;rahi  ana 
malt.  In  addition  to  Coffey's  still,  yanous  forms 
of  rectifying  stills  are  in  use  to  meet  special 


ALCOHOfj.  M 

raqatreninita,  t^.  ths  prodnctioa  of  •  purer  ,  by  pioduot,  whioh  indaed  it  now  oonddenbl^ 
though  not  Etninger  spirit  than  that  obtsinftble  t  niora  valaable  than  the  spirit  itself.  The  spirit 
from  the  CoCFej  still  for  tha  purpose  of  oonl' '  produced  does  not  to  enj  Urge  extent  «>  into 
poanden  and  certuu  mftnufoctuTtng  proceaaaf,  j  ooosumption  u  whiakey,  the  want  of  Bavoar 
■od  apparatus  having  for  their  object  (in  oon-  bein^  an  objection  in  regard  to  the  better 
sequence  of  the  increaaing  demand  tor  fosel  oil)  quaLties.  I-arge  quantitiea  are  transferred  to 
the  reooTcty  of  the  maximum  amoaat  of  this '  the  roctiSera,  who  redistil  them  nith  various 


94 


ALOOHOL. 


flATOuring  ingiedientB,  prodadng  gin,  British 
brandy,  British  ram,  and  the  vaiions  ooidialB, 
A  portion,  after  bdnff  xedistiUed  from  potasflinm 
carbonate,  or  filtered  through  oharooal,  is  used 
in  the  arts  and  in  medicine  nnder  the  names  of 
rectified  spirit  and  spirits  of  wine.  The  British 
PharmacopoBia  (1914)  requires  rectified  spirit 
to  be  of  a  specific  gravity  of  0*8337  at  15'6715'6'', 
equal  to  86*68  p.o.  of  alcohol  by  weaaht.  The 
Pharmaoopoeia  of  the  United  States  fixes  it  at 
0'820,  equal  to  91  p.o.,  which  is  about  the 
strength  it  comes  nrom  Ooffey's  apparatus. 
The  four  official  (B.F.)  diluted  alcohols  obtained 
by  mizing  90  p.o.  alcohol  {SpirUna  recUficaku) 
with  dismled  water  contain,  respectively,  70, 
60, 45,  and  20  p.o.  of  alcohol  by  volume. 
Th^  are  prepared  as  follows : — 

1.  Seoeniy  per  cent.  SptrU.—Bp.gt.  0*8899. 
Mix  310-6  0.0.  of  distilled  water  with  1  Utre  of 
90  p.c.  aloohoL  Or  dilute  777*8  ca  of  90  p.o. 
alcohol  with  water  so  as  to  make  1  litre  at  16*6**. 

2.  Sixty  per  cent.  SpirU.— 8p.gr.  0*9134.  Mix 
636*6  ao.  of  distilled  water  with  1  Utre  of  90  p.c. 
aloohoL  Or  dilute  666*7  o.c  of  90  p.c.  alcohol 
witii  water  so  as  to  make  I  litre  at  16*6^. 

3.  Forty-five  per  cent.  Spirit.-^-^.gr.  0*9436. 
Mix  1063*4  C.C.  of  distiUed  water  with  1  litre  of 
90  p.c.  alcohol.  Or  dilute  600*0  c.c.  of  90  p.c. 
alcohol  with  water  to  the  bulk  of  1  litre  at  16*6^ 

4.  Twenty  per  eetU.  Spirit.— 8p.gr.  0*9760. 
Mix  36680  o.c.  of  distilled  water  with  1  litre  of 
90  p.c.  alcohol.  Or  dilute  222*2  c.c.  of  90  p.o. 
alconol  with  water  to  the  bulk  of  1  litre  at  16°. 

Attompto  have  been  made,  especially  in 
America,  to  produce  alcohol  from  wood,  by  the 
Classen  process,  or  by  some  modification  of  it. 
This  process  consists  in  converting  the  cellulose  of 
the  wood  or  some  portion  of  it  into  dextrose  and 
other  sugars  by  treatment  with  dilute  add  under 
pressure,  and,  after  neutralising  the  add,  fer- 
menting the  sugar  with  yeast,  and  separating 
the  aloohoL  by  distillation.  The  yield  is  about 
21  ffallons  of  96  p.c.  alcohol  per  ton  of  wood, 
sawdust  or  pine  wood  waste  being  usually 
employed,  the  output  beinff  upwards  of  2000- 
2600  gallons  per  diem.  The  method  has  not 
been  commereially  successful  in  this  country, 
and  is  carried  on  only  to  a  limited  extent,  and 
under  exceptional  conditions,  in  the  United 
Stotes  (J.  Ind..  Eng.  Ghem.  1911,  3,  439 ;  1916, 
7,  920;    J.  Soc.  Chem.  Ind.   1912,  31,  613; 

1917,  36,  632 ;    1918,  37,  131 ;    Ghem.  Tr.  J. 

1918,  63,  103;  Zdtsch.  angew.  Chem.  1913, 
26,  786 ;  J.  pr.  Chem.  1916,  91,  368 ;  Chem. 
and  Metall.  Eng.  1918,  19,  662). 

Some  conslaerable  quantity  of  alcohol  is, 
however,  obtained  from  the  waste  liquors  formed 
in  the  manufacture  of  wood  pulp  by  the  sulphite 
process.  This  liquor  contams  from  1  to  2  p.c. 
of  sugars,  which,  after  neutralisation,  or  removal 
of  the  sulphur  dioxide,  can  be  fermented  and 
the  alcohol  recovered  by  distillation.  The 
industry  is  esteblished  in  Norway,  Sweden, 
Oermany,  Switzerland,  and  on  the  American 
continent.  The  yield  of  alcohol  is  said  to  be 
about  1  p.c.  or  rather  more,  of  the  sulphite 
waste  liquor.  The  spirit  obtained  contains 
methyl  alcohol,  and  is  therefore  unsuitable  for 
potoble  purposes;  but  it  can,  of  course,  be 
employea  as  motor  fuel,  and  for  other  uses 
where  a  denatored  spirit  is  applicable  ( Johnsen, 
J.  Soc.  Chem.  Ind.  1918,  37, 13  IT). 


The  synthetio  prodnotion  of  alcohol  from 
acetylene,  produoea  from  caldum  carbide,  was 
largely  developed  in  Germany  during  the  war. 
The  methods  employed  consist  either  in  trans- 
forming the  acetylene  into  ethylene  and  thence 
into  alcohol  by  treatment  with  oil  of  vitriol  and 
water  by  a  process  first  discovered  by  Hennell  in 
1828 ;  or  ly  converting  the  acetylene  into  alde- 
hyde in  presence  of  a  catalyst,  such  as  a  meroury 
salt,  and  then  reducing  the  aldehyde  to  ^ohol 
by  passing  ite  vapour,  mixed  with  hycbogen,  over 
finely  divided  nickel,  at  a  particular  temperature. 

For  descriptions  of  the  various  forms  of 
poteble  spirit — brandy,  rum,  whisky,  gin,  fte. — 
eee  the  special  articles  on  these  subjecto. 

Propmee. — ^In  the  dehydrated  condition 
ethyl  alcohol  is  a  colourless  liquid,  having  a 
specific  gravity  of  0*791  at  20*'/20''  (Lointz, 
(Mi's  Ann.  1796,  1,  1),  0*7938  at  16*6»/16*6<* 
(Fownes,  Phil.  Trans.  1847,  249),  0*793811  at 
16*6''/16'6''  (Drinkwater,  Phil.  Mag.  Feby.  1848), 
0*79360  at  1667166',  0*79367  at  1674*» 
(Mendelfoff,  Pogg.  138,  230),  (Squibb,  Ephe- 
meris,  1884-6,  and  Pharm.  J.  [3]  16,  147- 148), 
0*7861  at  2674^'  (Winkler,  Kailan.  Osborne, 
McEelvy,  and  Bearce,  J.  Washington  Acad. 
Sd.  1912,  2,  96),  0*7936  at  1674MSchoori  and 
RegenlxM^en,  Proc.  K.  Akad.  Wetensch.  Amster- 
dam, 1918,  20,  831),  0*80627  at  (f/A"*  (Young, 
Elason,  and  Norlin,  Meiriman).  It  boils  at  78*4® 
under  a  pressure  of  760  mm.  (Kopp,  Annalen, 
92, 9),  78*3''  (Young  and  Merriman),  and  solidifies 
at  -130*6°  (Wroblewski  and  Olsewski,  Compt. 
rend.  96,  1140  and  1126),  -112*3''  (Ladenbuig 
and  Krugel,  Ber.  1899,  32,  1818).  It  is  inflam- 
mable, the  combustion  evolving  g^reat  heat  but 
little  light,  and  producing  carbon  dioxide  and 
water.  It  acto  as  a  caustic  irritant  in  contact 
with  the  tissues  of  the  body,  owing  probably 
to  the  eneigy  with  which  i^  draws  moisture 
from  the  surface.  It  possesses  a  spedfic 
heat  of  0*6120  at  temperatures  between  16^ 
and  40*6°  (SchiiUer,  P.  Erg.  6,  116-192).  Ito 
index  of  refraction  for  H/B«  1*3667  (Briihl),  and 
its  critical  temperature  243*6''  at  48*9  m.  At 
this  point  1  gram  occupies  3*6  c.c.  (Ramsay 
and  Young,  Proc.  Boy.  Soc.  38,  329). 

Vapoxjb  PfisssuBs  OF  Ethtl  Alcohol. 
(Merriman,  Trans.  Chem.  Soc  1913,  103,  632.) 


Preiuuie 

Pressure 

• 

in  mm. 

0 

in  mm. 

0 

12*0 

18 

38*7 

1 

12*9 

19 

41*2 

2 

13*9 

20 

43-8 

3 

14*9 

21 

46*6 

4 

16-9 

22 

49*4 

6 

17*0 

23 

62*4 

6 

18*2 

24 

66-6 

7 

19*4 

26 

69*0 

8 

20*7 

30 

78*6 

9 

22  1 

40 

134*9 

10 

23-6 

60 

222*2 

11 

261 

60 

362*7 

12 

26-7 

70 

642*6 

13 

28-4 

80 

812*7 

14 

30-3 

90 

1187-0 

16 

32-2 

100 

1694*0 

16 

34-3 

105 

2007  0 

17 

30-4 

The  viscosity  of  ethyl  alcohol  at  various 
temperatures  has   been  measured   by  Thorpe 


ALOOHOL. 


05 


and  Rodger  (Plul.  Tnna.  1894,  186,  II,  533), 
witii  the  resaltB  shown  in  iho  annexed  table : — 


Tanpentturefl . 


42-84 

49-37 
55-67 
61-07 
67-65 
73-57 


O-OOTSVS 
0-007047 
0-006364 
0-005816 
0-005263 
0-004764 


Tempentvrei. 

7-16  0-015328 

13-23  0-013573 

19-22  0-012094 

25-24  0-010792 

31-89  0-009560 

37-51  0-008644 

Th»  electric  condaotiTitY  of  alcohol  and  of 
its  aqneona  solutions  has  oeen  determined  at 
15%  Dj  BoTOSohewsky  and  Rosohdestvensky 
(J.  Ross.  Phys.  Ghem.  Soo.  1908,  40,  887 ;  «f . 
Soo.  Chem.  Ind.  1909, 28,  853). 

Ethyl  alcohol  is  hygroscopic  and  is  misoiUe 
with  water  in  all  proportions.  On  adding  water 
to  anhydrons  aloonol  a  considerable  dcTelojpment 
of  heat  oocois  owing  to  the  contraction  m  the 
resnhant  Yolnme.  The  maxininm  contraction  is 
f  onnd  by  mixing  48  vols,  of  water  with  52  vols. 
ol  anhydrous  alcohol,  measured  at  15-56^. 

H.  T.  Brown  (Analyst,  1916,  40,  379)  has 
shown  from  the  alcoholometric  tables  published 
by  Thorpe  that  in  the  case  of  mixtures  of  yery 
dilute  sJcohol  and  water  there  is  a  slight  expan- 
sion instead  of  contraction. 

Commercial  *  absolute '  alcohol  usually  con- 
tains about  1  p.c.  to  1-5  p.c.  of  water.  In  the 
B.P.  (1914)  'absolute'  alcohol  is  defined  as 
'  ethyl  hydroxide  C|H(OH,  with  not  more  than 
1  p.0.  by  weight  of  water;  sp.ffr.  from  0*794 
(eauiyalent  to  99*95  p.c.  of  etl^f  hydroxide  by 
▼olume  and  bj  weight)  to  0*7969  (equivalent 
to  99*4  p.c.  of  ethyl  hydroxide  by  volume  or 
99  p.0.  by  wdght).  Anhydrous  copper  sulphate 
shaken  occasionally  during  two  or  three  nours 
in  a  well-dosed  vessel  with  about  fifty  times  its 
weight  of  abaotate  alcohol  does  not  assume  a 
deadedlv  blue  colour  (absence  of  excess  of  water). ' 

Absolutely  anhydrous  alcohol  should  give  no 
olondiness  when  mixed  with  benzene,  and  no  pink 
oolomation  when  shaken  with  a  crystal  of  potas- 
sium permanganate,  and  no  turbidity  or  evolu- 
tion of  gas  ^acetylene)  in  contact  with  oaldum 
oarlnde.  Annydrous  alcohol  added  to  a  fragment 
€d  anthraquinone  and  sodium  amalgam  acquires 
a  green  colour ;  if  a  trace  of  water  be  present 
the  colour  becomes  red  (Claus,  Ber.  10,  927). 

Ethyl  aloohol  is  reisdily  detected  by  the 
formation  of  ethyl  aeekUe  on  adding  sodium 
acetate  and  a  few  drops  of  acetic  acid  to  the 
liquid  to  be  tested,  together  with  an  equal 
volume  of  strong  sulphuric  add,  and  heatins 
the  mixture,  when  the  characteristic  smell  of 
ethyl  aoetate  is  produced.  A  less  characteristic 
reaction  is  the  formation  of  iodoform  when  the 
liquid  is  mixed  with  a  few  drops  of  a  solution  of 
iodine  and  warmed  and  the  colour  of  the  iodine 
destroyed  by  a  solution  of  sodium  carbonate  or 
hydroxide.  If  bemoyl  chloride  be  shaken  with 
we  liquid,  it  forms  ethyl  benzoate ;  on  warming 
tiie  decanted  solution  with  a  solution  of  caustic 
potash  the  ethyl  benzoate  ia  reoogmaod  by  its 
odour.  Other  tests  are  the  formation  of 
aldehifde  by  the  action  of  a  mixture  of  potassium 
dichromate  and  sulphuric  add,  recognised  by 
its  smell  and  its  behaviour  with  SchifiTs  reagent ; 
the  formation  of  dinilropheneioU  (Blanksma, 
Ghem.  Weebklad,  1914,  11,  26);  phthalie  ester 
(Rdd,  J.  Amer.  Chem.  Soc.  1917,  39,  1249). 


According  to  Pasteur  very  small  traces  of  ethyl 
alcohol,  espMoally  in  fermented  liquids,  may  be 
detected  on  distimng  the  aqueous  liquid  suspected 
to  contain  it  by  observing  the  formation  of  the 
strisB,  or  *  tears  *  producM  by  the  condensation 
of  the  first  few  drops  of  the  distillate.  A  few  cc. 
of  the  liquid  to  be  tested  are  placed  in  a  wide 
test  tube  fitted  with  a  cork  and  a  long  glass 
tube.  The  liquid,  which  should  contain  a  spiral 
of  copper  or  platinum  wire,  or  a  few  fragments 
of  pumice,  to  ensure  regular  ebullition,  is  neated 
by  a  small  flame  and  the  formation  of  the  *  tears  * 
in  the  long  tube  noticed.  With  care  as  little  as 
0-001  p.c.  of  alcohol  can  in  this  way  be  detected. 

Alcohol  forms  ethoxides  with  sodium  and 
potassium,  and  unstable  compounds  with  certain 
crystalline  salts,  e,g.  zinc  ddoride,  the  latter 
called  alcoholates.  Subjected  to  the  action  of 
a  limited  supply  df  oxvffen,  it  is  converted  into 
aldehyde  (CiH^O),  whicn,  by  further  oxidation, 
becomes  acetic  add  (0,1140,).  IKstilled  with 
chloride  of  lime,  it  forms  chloroform  (CHCl,). 
With  sulphuric  acid  at  a  temperature  not  ex- 
ceeding 146''  it  yidds  ether  (C«HioO).  With 
twice  its  bulk  of  sulphuric  acid  it  gives  ethylene 
(C,H4).  With  excess  of  dry  cUorine  gas  it 
produces  chloral  (C.H(}1,0). 

Usee. — ^In  addition  to  its  use  as  a  beveraee, 
spirit  is  employed  as  a  solvent  for  many  of  we 
<&ugs  required  in  medicine,  and  dilutea  to  the 
standard  of  British  proof — ihBt  is,  to  the  roecific 
mvity  of  0*91976  at  16*6'',  representing  49-28  p.c. 
by  weight  of  Drinkwater  and  Fownes  alcohol — 
it  forms  part  of  a  large  proportion  of  the  tinc- 
tures of  the  Materia  Medica.  It  is  also  used 
largdy  as  a  solvent  for  essential  oils,  in  pre- 
paring perfumes  and  essences,  and  ether  and 
other  ethyl  derivatives  are  manufactured  from  it. 

Methylated  spirit  In  1863  a  strong  renre- 
sentation  was  made  to  the  Government  to  aUow 
the  use  of  alcohol  duty  free  in  the  arts  and 
manufacturing  processes  in  which  it  was  re- 
quired, and  after  careful  uiquiry  the  Board  of 
Inland  Revenue  in  1866  decided  to  sanction, 
under  certain  restrictions,  a  mixture  of  nine 
parts  of  spirits  of  wine  and  one  part  of  methyl 
aloohol  (wood  naphtha)  free  of  duty  under  the 
name  of  methylaied  epirits.  In  1861  the  per- 
mission was  extended  to  all  other  purposes  except 
consumption  as  a  beverage  or  as  a  medicine. 
The  reasons  for  selecting  wood  naphtha  were  that 
whilst  it  would  be  least  likely  to  interfero  in  any 
of  the  processes  for  which  alcohol  was  required — 
especially  as  a  solvent — it  would  be  very  difficult 
to  separate  from  the  alcohol  when  once  mixed. 
The  principal  restriction  on  the  use  of  methyl- 
ated spirit  is  that  it  shall  only  be  ke^t  by 
authorised  persons  and  in  authorised  premises. 

In  1891  it  was  found  necessary  (owing  to  the 
possibility  of  methylated  spirit  being  sumdently 
purified  to  render  it  fit  for  potable  purposes,  and 
the  srowing  practice  of  drinking  even  the  un- 
purified  methylated  spirit  by  the  poorer  classes 
m  some  of  the  larger  cities)  to  again  restrict  the 
use  of  methylated  spirit  made  as  above  described 
{i.e.  *  ordinary  methylated  spirit ')  to  manu- 
facturers only,  and,  even  then,  subject  to 
revenue  restrictions,  and  to  prescribe  the 
addition  of  a  further  denaturant  to  methylated 
spirit  intended  for  general  purposes.  This 
denaturant  consists  of  mineral  naphtha  (petro- 
Jeum),  and  the  mixturo,  known  as  *  mineralieed* 


06 


ALCOHOL. 


methylated  apirity  may  be  sold  by  licenoed 
retailm  to  the  general  publio  for  any  purpose 
to  wtdoh  it  is  applicable,  as  lighting,  heating, 
cleansing,  or  mixing  with  paints,  vamishoe,  fta 

It  was  found,  however,  that  '  ordinary ' 
methylated  spirit  was  not  universally  applicable 
to  manufacturing  prooessee  requiring  tne  use  of 
alcohol,  and  aocordindy,  in  1902,  the  Com- 
missioners of  Liland  Kevenue,  under  powers 
confeixed  upon  them  by  the  Spirits  Act  <n  1880 
and  the  Finance  Act  of  1002,  authorised  the  use 
of  duty-free  alcohol  denatured  with  substances 
other  than  wood-naphtha  in  certain  manufactur- 
ing operations  and  subject  to  special  conditions. 

As  the  result  of  an  inquiry  by  a  Depart- 
mental Committee,  in  190^-5,  the  amount  of 
wood-naphtha  to  be  used  as  a  denaturant  for 
*  ordinary  '  methylated  spirit  used  for  industriai 
purposes  was  reduced  from  10  to  5  p.c.  of  the 
mixture.  This  is  described  as  *  industrial* 
mdhylaied  spirU. 

At  the  present  time  (1020),  there  are,  there- 
fore, two  descriptions  of  methylated  spirit  offici- 
ally recognised  m  the  United  fon^dom^  viz. : 

(a)  mineraliui  mdhylaied  spirU  as  sold  by 
licensed  retailers  for  general  use  (except  for  the 
preparation  of  beverages  os  medicine),  and  con- 
taining not  less  than  10  p.a by  volumeof  approved 
wood-naphtha,  and,  in  addition,  not  lees  than 
0-376  p.0.  of  approved  mineral  naphtha  (petro- 
leum of  specific  sravity  not  less  than  0*800). 

(&)  Indugtruu  mdhylaied  spiriif  intended  for 
use  in  manufacturing  processes,  and  sold  only  by 
methylators  to  persons  authorised  to  receive 
this  kind  of  spirit.  This  must  contain  not  less 
than  5  p.c.  of  approved  wood-naphtha  or  other 
substance  or  combination  of  substances  approved 
by  the  Commiasioners  of  Customs  and  Excise. 

The  wood-naphtha  must  be  sufficiently  im- 
pure to  make  the  methylated  spirits  so  nauseous 
as  to  render  them  incapable  of  being  used  as  a 
beverage  or  of  being  mixed  with  potable  spirits 
without  rendering  them  unfit  for  human  con- 
sumption. It  miut  contain  not  less  than  72  p.c. 
by  volume  of  methyl  alcohol,  and  not  more  than 
12  crams  per  1(X)  cc  of  aldehydes,  acetone,  and 
higher  ketones,  estimated  as  acetone  by  Mes- 
singer's  iodoform  process,  nor  more  than  3  grams 
of  esters  estimated  as  methyl  acetate  by  hydro- 
lysis; not  more  than  30  cc.  of  naphtha  shall 
be  required  to  decolourise  an  aqueous  solution 
containing  0*6  gram  of  bromine,  and  6  c.c.  at 
least  of  deci-normal  acid  shall  be  required  to 
neutralise  26  ac.  of  the  spirit  when  methyl 
orange  is  used  as  indicator. 

The  wood-naphtha  which  is  now  used  by 
methylators  is  fairly  uniform  in  character  as 
regards  ito  content  of  methyl  alcohol,  and  it  is 
by  the  recognition  of  this  alcohol  that  the 
presence  of  methylated  spirits  is  usually  de- 
tected. Acetone  is  present  m  much  more  varying 
quantities,  whilst  unsaturated  alcohols,  com- 
pound ethers,  and  nitrogenous  basic  substances 
are  present  in  too  small  and  vaning  proportions 
to  afford  suiteble  means  for  detecting  methy- 
lated spirite  in  mixtures. 

The  most  satisfactory  methods  for  detecting 
methyl  alcohol  in  presence  of  ethyl  alcohol 
dep^d  either  on  differences  in  the  physical  pro- 
perties of  the  alcohols  themselves,  or  on  differ- 
ences in  the  chemical  behaviour  of  their  deriva- 
tives or  products  of  oxidation,  but  of  these,  few 


are  capable   of  indicating  with   certainty  the 
presenoe  of  less  than  1  p.c.  of  methv)  alcohol. 

Of  the  methods  which  have  hitherto  been 
devised  for  this  purpose,  none  can  compare,  as 
regards  the  certainty  of  the  conclusions  wliich 
may  be  drawn  from  the  results,  with  that  of 
Riche  and  Bardy,  which  depends  on  the  ultimate 
formation  of  methylaniline  violet  and  ito  de- 
position on  wool  (Compt.  rend.  1876,  1976).  As 
a  preliminary  test,  and  one  which  may  with 
advantage  m  incorporated  in  the  Riche  and 
Bardy  process,  the  following  will  be  found  to  be 
usefuL  About  10  c.c.  of  the  strong  spirit — ^freed, 
if  necessary,  from  essential  oik,  &c.,  by  the 
salt-petroleum  method  and  fractionated  from 
potassium  carbonate  (v.  Alooholhetry) — ^are 
placed  with  30  grams  of  powdered  iodine  in  a 
small  round-bottomed  flask  which  can  be  readily 
connected  with  a  condenser.  Two  flrams  of 
amorphous  phosphorus  are  added  and  the  result- 
ing alkyl  icMlides  distilled  and  collected  under 
water  in  a  small  separator.  When  from  10  to 
12  ca  have  been  collected,  the  iodides  are  washed 
with  water,  decolourised  with  dilute  potash,  and 
drawn  off  from  Uie  aqueous  layer  into  a  flask 
containing  a  little  frahly  heated  potassium 
carbonate.  After  remaining  an  hour  cat  so  with 
occasional  shaking,  the  potassium  carbonate  is 
removed  by  filtration,  and  the  boilmg-point  of 
the  iodides  carefully  detemdned.  Ordinary 
ethyl  alcohol  yields  an  iodide  which  has  a  con- 
stent  boiling-point  of  72*.  When  methyl 
alcohol  is  present  in  the  spirit,  the  initial 
boiling-point  of  the  iodides  is  lower  and  a 
portion  distils  below  this  temperature.  By 
noting  the  temperature  at  wnich  the  first 
drop  of  distilled  iodides  falls  into  the  condenser 
ana  receiver  respectively,  the  presence  of  rela- 
tively small  quantities  of  methyl  alcohol  can  be 
detected.  The  resulte  (see  taUe  in  next  od.) 
obtained  with  synthetic  mixtures  indicate  the 
deUcacv  of  the  method. 

In  doubtful  cases,  or  when  the  initial  boiling- 
point  is  below  70*,  the  first  fraction  of  3  ao.  of 
distilled  iodides  is  digested  with  an  equal 
volume  of  aniline  at  a  moderate  temperature, 
and  the  Riche  and  Bardy  method  proceeded 
with.  After  stendin^  one  hour,  hot  water  is 
added  to  the  oiystallme  mass,  and  the  mixture 
boiled  for  some  minutes,  26  c.c  of  strouff  potash 
solution  are  then  added,  and  the  liberated  aniline 
oil  washed  with  water ;  1  cc  of  this  oil  is  inti- 
mately mixed  with  10  grams  of  a  mixture 
consisting  of  100  grams  of  dry  quartz  sand, 
3  grams  ol  onpric  nitrate,  and  2  grams  ol 
common  salt,  and  the  mixture  introduced  into 
a  wide  tube  and  heated  for  some  hours  at 
90*-100*.  The  product  is  exhausted  with  warm 
alcohol  and  the  extract  filtered  and  made  up  to 
a  volume  of  1(X)  cc. 

If  the  sample  of  spirit  contained  ethyl 
alcohol  only,  the  colour  of  the  liquid  will  be 
red,  but  in  the  prraence  of  1  p.a  of  methyl 
alcohol  it  has  a  dustinct  violet  shade,  whilst  m 
the  presenoe  of  2  p.c.  the  violet  is  very  decided, 
and  becomes  more  so  as  the  proportion  of 
methyl  alcohol  increases.  6  ao.  of  the  alco- 
holic extract  are  then  mixed  with  water  to  a 
volume  of  100  cc,  and  2  cc  of  this  dye  diluted 
with  water  to  about  400  cc.  The  mixture  is 
now  heated  to  a  temperature  not  exceeding  76*, 
and  from  two  to  three  feet  of   Berlin  wool, 


ALOOHOLOMETRY. 


07 


previouBlj  freed  from  gTea<«  by  treatment 
with  hot  dilute  potash,  immersed  in  it  for  30 
minutes. 


Peroentsge  of 
methyl  alcohol  by 
volume  in  the  mix- 
ture of  alcohols 

Temperature  st 

which  the  first 

drop  of  iodides 

fiOls  into  the 

condenser 

Volame  of  dis- 
tillate obtained 
below  72*»  from 

10  O.C.  of 

Iodides 

0.0. 

NU 

70* 

Nil 

0*38 

69^ 

0-2 

0-94 

65« 

0-8 

1-86 

63« 

2-2 

2-77 

62' 

4-0 

3-66 

«)• 

5-0 

4-55 

68* 

60 

6^2 

67« 

6-2 

6*26 

66* 

6-4 

•710 

W 

6-5 

10-00 

62* 

7-6 

Pore  ethyl  alcohol  under  these  conditions  will 
not  produce  a  dye,  and  the  wool  after  washing 
and  drying  remains  practically  white.  If,  how- 
ever, metnvl  alcohol  was  originally  present,  the 
fibre  will  be  violet,  the  tint  becoming  more 
intense  and  increasing  in  depth  according  to  the 
quantity  present.  Riche  and  Bardy  recommend 
that  5  CO.  of  the  above  diluted  dye  should  be 
taken  instead  of  2  c.o.  as  here  described,  but 
although  by  this  means  a  more  intense  dye  is 
obtained  when  methyl  alcohol  is  present,  it  is  found 
that  an  appreciable  dye,  although  not  of  the 
same  colour,  is  deposited  when  pure  ethyl  alcohol 
has  been  operated  with,  and  this  may  lead  to 
confusion.  For  purposes  of  comparison  it  is 
therefore  advisable  to  operate  concurrently  with 
a  sample  of  rectified  spirits. 

If  it  be  desired  to  estimate  the  proportion 
of  methyl  alcohol  or  methylated  spirits  in  a 
sample,  the  method  of  Thorpe  and  Etoknes  may 
be  employed.  This  method  depends  on  the 
complete  ozidation  of  methyl  alcohol  to  carbon 
dioxide  by  means  of  chromic  add  mixture, 
rectified  spirits  under  the  same  conditions 
yielding  only  a  small  quantity  of  carbon 
dioxide  equivalent  to  O'Ol  gram  for  each  gram 
of  ethyl  alcohol  present  (Chem.  Soo.  Tirana. 
1904.  1). 

As  a  result  of  many  experiments  it  has  l)een 
proved  that  unless  the  boiling-point  of  the 
iodides  is  abnormal,  no  dye  is  obtained  by  the 
Riche  and  Bardy  method,  nor  does  the  yield  of 
carbon  dioxide  on  oxidation  exceed  the'  limits 
ffiven  above  for  rectified  spirits,  but  in  all  oases 
in  which  a  dye  is  obtained  a  proportional  excess 
of  carbon  dioxide  is  also  obtained. 

In  other  countries  there  are,  as  a  rule,  classes 
of  denatured  alcohol  corresponding  more  or  less 
with  those  authorised  in  the  United  Kingdom, 
I.e.  spirit  for  general  use  so  completely  denatured 
as  to  be  deemed  undrinkable,  and  spirit  not 
absolutely  denatured  and  iotended  for  use  by 
responsible  manufacturers  subject  to  a  more  or 
less  strict  revenue  control. 

Wood-naplitha  is  the  denaturant  most  in 
favour  for  spii-it  intended  for  general  use,  tiie 
nauseous  character  of  the  methylated  spirit 
being  sometimes  intensified    by   the  addition 

Vol.  L— r. 


of  such  substances  as  pyridine  bases,  benzine, 
&c. 

In  France,  spirit  for  general  use  contains  one- 
eleventh  of  its  volume  of  officially  approved 
wood-naphtha,  with  an  addition  (when  used  for 
lighting  and  heating  purposes)  of  0*5  p.o.  of  heavy 
benzine  distilling  oetween  160*  and  200*  and 
4  p.0.  of  gum  resin  for  *  finish.' 

In  Oermany,  the  official  formula  is  2  p.o.  of 
wood  naphtha,  0*5  p.o.  of  pyridine  bases,  and 
(optionallv)  0*125  p.0.  of  rosemary  oiL  Spirit 
intended  for  motor  cars,  and  internal  combostion 
engines  is  denatured  by  adding  1  p.c.  of  wood- 
naphtha,  0*25  p.0.  of  pyridine  base%  0*25  p.o.  of 
a  solution  of  methvl  violet  d^e,  and  from  2  to  20 
p.c.  of  benzol  to  the  pure  spirit. 

In  the  UnUed  States  of  America^  10  p.0.  of 
approved  methyl  alcohol  and  0*5  p.c.  of  benzene 
is  presoribed  to  be  added  to  spirit  denatured  for 
general  use. 

In  Beigivm,  speoitio  denaturants  are  pre- 
scribed for  each  of  the  principal  manufacturers, 
and  this  practice  obtains  in  certain  other 
oountries,  as  Germany,  France,  Switzerland, 
America,  and  the  United  Kingdom,  when  it  can 
be  shown  that  ordinary  methylated  spirit  is 
unsuitable.  In  such  cases  the  denaturanta  are 
naturally  very  varied  in  character,  being  specially 
adapted  to  the  particular  necessities  of  each 
manufacturer. 

(Minutes  of  Evidence  and  Report  of  the 
Department  Committee  on  Industrial  Alco- 
hol^ 1005;  Herrick,  Denatured  or  Industrial 
Alcohol.)  

ALCOHOLOHETRT  is  the  term  applied  to 
any  process  for  estimating  the  amount  of  alcohol 
in  a  spirituous  liquid.  In  simple  mixtures  of 
alcohol  and  water  a  determination  of  specific 
gravity  at  a  standard  temperature  affonis  an 
accurate  index  of  alcoholic  content,  and  it  is 
bv  taking  advantage  of  this  fact  that  the  sssay 
of  spirit  for  revenue  and  commercial  purposes 
is  usually  carried  out. 

When  alcohol  and  water  are  mixed  together 
the  volume  of  the  mixture  is  invariably  less 
than  the  sum  of  the  initial  volumes,  and  the 
degree  of  contraction  varies  with  the  proportion 
of  alcohol  present.  In  countries  in  wluch  tlie 
revenue  from  spirit  Is  of  great  importance  it  has 
therefore  been  found  necessary  to  ascertain  by 
experiment  the  specific  gravities  of  mixtures  of 
alcohol  and  water  in  all  proportions  and  at 
various  temperatures.  These  experiments  have 
in  general  been  carried  out  at  the  request  of  the 
Qovemments  interested,  and  the  results  are 
embodied  in  tables  associated  with  the  names  of 
those  entrusted  with  the  investigations. 

In  1794  Sir  Charles  Blagden  and  Mr.  Qilpin 
completed  an  extensive  series  of  experiments, 
undertaken  at  the  request  of  the  British  Govern- 
ment (Phil  Trans.  1790-1794),  the  results  of 
which  have  since  served  as  the  basis  of  systems  of 
alcoholometrv  in  tliis  and  other  countries.  At 
that  time  anhydrous  alcohol  had  not  been  pre- 
pared, Blagden  and  Gilpin's  tables  having  refer- 
ence to  spirit  of  a  sp.  gr.  0*825  at  15-0Vl5*6^ 
(60V60''F.).  Tralles,  in  1811,  conducted  a 
like  investigation  for  the  Prussian  Government 
(GUb.  Ann.  1811),  and  adopted  0-7946  as  the 
specific  gravity  of  alcohol  at  15*6716*6*.  He 
incidentally  confirmed  the  general  accuracy  of 
the  results  of  Blagden  and  Gilpin,  and  constructed 


98 


ALCOHOLOMETRY. 


tablet  of  spirit-stroiijtths  which  for  upwards  of 
sixty  yean  formed  the  baaii  of  German  alooholo- 
metry.  Similar  reaearohea  were  ondertaken  by 
Gay. Lmiac  (Paris,  1824),MoCallooh(WaahuigtOD, 
1848)»Baiuiihaiier(Amsterdam,  1860),  Mendel^fl 
(St.  Petersburg,  1866),  and  more  recently  by 
the  Kaiseriiche  Normal  Eichungs  Kommiasion 
(Beriin,  1889),  the  several  results  of  which  have 
from  time  to  time  been  incorporated  in  the 
systems  of  alcoholometry  adopted  by  the  respec- 


tive Goveniments.  The  unufBotal  ioveetigation?, 
of  Fownes  (Phil.  Trans.  1847),  DrinJcwater 
(Chem.  Soo.  Mem.  1848),  and  Squibb  (Ephemeris, 
1884),  are  likewise  entitled  to  consideration. 

Drinkwater  prepared  alcohol  of  a  specific 
gravity  0-79381  at  16-6715-6*  (m  air),  whilst 
Squibb  obtained  it  as  low  as  0*7936,  but  this 
result  lacks  confirmation. 

The  work  of  Mendel^ff  for  the  Russian 
Government  admittedly  constitutes  the  most 


Specific 
gravity  In^air 

Percentage  of  alooliol 

1 

Percentage 
of  fiscal 

Specific 
gravity  in  air 

^t  l5-«° 

Percentage  of  alcohol 

-Percentage 
of  fiscal 

by  weight 

by  volome 
at  16-8° 

proof  spirit 

by  weight 

by  volame 
at  15-6° 

proof  spirit 

0-79359 

100-00 

100-00 

175*35 

0-898 

58-93 

66-67 

116-81 

0*794 

99-87 

99-92 

175-21 

0-900 

58-06 

65*83 

115-33 

0-796 

99*22 

99-52 

174*52 

0-902 

57*18 

64-98 

113-84 

0-798 

98*57 

9912 

173-80 

0-904 

56-3] 

64-13 

112-35 

O'SOO 

97*91 

98-70 

173-07 

0-906 

55-42 

63*26 

110-82 

0*802 

97*25 

98-28 

172-33 

0*908 

54-64 

62*39 

109-29 

0-804 

96*67 

97*84 

171*56 

0*910 

53-65 

61-51 

107*74 

0*806 

96*89 

97*39 

170-77 

0-912 

52-77 

60-63 

106-20 

0-806 

95*20 

96*93 

169-96 

0*914 

51-88 

59*74 

104-63 

0*810 

04*50 

96-45 

169*13 

0*916 

50-98 

58-83 

103-05 

0-812 

03-80 

95-97 

168*28 

0^18 

50-08 

57-92 

10143 

0-814 

93-08 

95-47 

16741 

0*91976 

49*28 

57*10 

100-00 

0*816 

92-36 

94-97 

166*51 

0*920 

49*17 

50*99 

99*80 

0-818 

91-63 

94-45 

165-60 

0*922 

48*25 

56-06 

98-16 

0-820 

90*90 

93-92 

164*67 

0-924 

47-33 

55-10 

9649 

0-822 

90*16 

93-38 

163*72 

0-926 

4640 

54-14 

94-80 

0*824 

8941 

92-83 

162*75 

0*928 

4547 

5316 

93-09 

0-826 

88*65 

92-26 

161*76 

0-930 

44-53 

52-18 

91-36 

0-828 

87*88 

91-69 

160*75 

0-932 

43-59 

61  18 

89*61 

0-830 

8711 

91-11 

169*73 

0-934 

42-62 

50-15 

87-81 

0-832 

86-34 

90-62 

158*69 

0-936 

41-64 

49-10 

85-97 

0-834 

85-56 

89-91 

157*63 

0-938 

40-65 

48-04 

84-10 

0-836 

84*78 

89-30 

166*56 

0-940 

89-66 

46-95 

82-19 

0-838 

83-99 

88-68 

155-47 

0-942 

88-64 

45  85 

80-26 

0-840 

83*20 

88-06 

154-37 

0-944 

37*60 

44-71 

78-26 

0-842 

82-40 

87-42 

153*25 

0*946 

36-54 

43-54 

76-21 

0-844 

81*60 

86*77 

152*12 

0-948 

3546 

42-35 

74  12 

0-846 

80*79 

86-12 

150-97 

0-950 

34-37 

41-13 

71-98 

0-848 

79*98 

85^16 

149*80 

0-952 

33-25 

39-87 

69-76 

0-860 

79*17 

84*78 

148-62 

0*954 

32-09 

38-67 

6748 

0-862 

78-35 

84*11 

147-43 

0-956 

30-90 

37-20 

65-09 

0-854 

77-53 

83*42 

146-23 

0-958 

29-66 

35-79 

62-60 

0-856 

76-71 

C2-73 

145-01 

0-960 

28-39 

34-33 

60-03 

0-858 

75-88 

82*03 

143-78 

0-962 

27-06 

32-79 

57-33 

0-860 

75*05 

81-32 

142*54 

0-964 
0-966 

25-68 

31-18 

54-61 

0-862 

74*22 

80*61 

141*28 

24*23 

2948 

51-63 

0-864 

73-39 

79*89 

140-02 

0-968 

22*71 

27-69 

48-38 

0-866 

72*66 

79-16 

138-74 

0-970 

21*14 

.  25-83 

45-1  i 

0-868 

71*72 

78-43 

137-46 

0-972 

19-53 

23-91 

41-77 

0-870 

70-88 

77-69 

13616 

0-974 

17-90 

21-96 

38-35 

0-872 

70*04 

76-04 

134*84 

0-976 

16-25 

19-98 

34-87 

0-874 

69-19 

76  19 

133-53 

0-978 

14-61 

18-00 

3142 

0-876 

68  35 

75-44 

132*19 

0-980 

12-99 

16-04 

27-99 

0-878 

67-51 

74-68 

130-86 

0-982 

1142 

1413 

24:66 

0-880 

66-66 

73*91 

129-60 

0-984 

9-91 

12*29 

2144 

0-882 

65-81 

73*13 

128-14 

0-986 

846 

10-51 

18-34 

0*884 

64-96 

72*34 

126-77 

0-988 

7-08 

8-80 

15*38 

0*886 

64*10 

71*55 

126-37 

0-990 

5-76 

7-18 

12-53 

0*888 

63*24 

70*75 

123-97 

0*992 

4*51 

5-63 

9-82 

0*890 

62*38 

69*95 

122-56 

0*994 

3-31 

414 

7*24 

0*892 

61*52 

69*14 

121*14 

0-996 

2  17 

2-71 

4-73 

0-894 

60*66 

68-33 

119*70 

0*998 

1-07 

1-34 

2  33 

0*896 

59-80 

67-50 

118*26 

1-00000 

0*00 

0-00 

0-00 

ALCOHOLOMETRY. 


09 


oompietieiiaiTe  and  exact  of  the  researches 
hitherto  made  in  the  field  of  aleoholometiT. 
Mendd<^ff  obtained  alcohol  of  a  speoino 
mvity  0-79426  at  16V16»,  which  at  16-6V15-6* 
18  equivalent  to  0*79384  in  a  yacnnm,  or  to 
0*79359  in  air,  and  he  assigned  to  Drinkwater's 
alcohol  an  alcoholic  content  of  99*95  ]^.o.,  and  to 
the  strong  spirit  of  Blaeden  and  Gilpin  89*06 
ao.  by  weight.  The  resvJts  of  Tralles'  and  6ay- 
Lnssao's  experiments,  beins  based  on  alcohol 
lees  dehydrated  than  that  <h  Drinkwater,  com- 
pare less  f avoDrably  with  those  of  Mendel^ff . 

l^endel^ff  was  so  well  satisfied  with  the 
work  of  Bladen  and  Gilpin,  and  Drinkwater, 
that,  for  spintnoos  mixtures  of  low  strength,  he 
included  many  of  their  results  in  his  taoles  of. 
spirit-densities,  and  after  a  critical  investigation 
and  subsequent  verification  by  the  Kaiserliche 
Normal  Eichnnfls  IB^ommission,  his  results  have 
been  substantiiuly  adopted  as  the  basis  of  the 
preeentratem  of  German  alcoholometry  in  pJace 
of  the  leiatively  less  accurate  data  of  Tralles. , 

The  results  of  the  work  of  these  four  autho- 
rities have  been  incorporated  in  the  accompany- 
ing table  of  spirit-densities,  which  may  serve 
for  Uie  pyknometrioal  determination  of  the  true 
strength  of  spirits.  In  the  assessment  of  duty 
and  in  oommeroial  transactions,  the  standard  of 
stzength  is  termed  'proof.'  Spirit  of  proof 
strength  is  defined  as  ^that  which  at  the  tem- 
perature of  51*F.  (10*6*0.)  weighs  exactly  {]ths 
of  an  equal  measure  of  diiatilled  water '  also  at 
10*6*.  According  to  the  best  available  data 
this  mixture  of  Mcohol  and  water  has  a  specific 
gravity  of  0*91976  at  15*6V16'6^  and  contains 
40-28  p.c.  by  weight  and  57*10  d.o.  by  volume 
of  anhydrous  alcohoL  Spirits  which  contain  a 
greater  proportion  of  alcohol  than  is  contained  in 
proof  spirit  are  said  to  be  of  overproof  strength 
(o.p.),  and  those  which  contain  a  smaller  propor- 
tion are  said  to  be  of  underproof  strength  (u.p.). 
Variations  of  temperature  are  deemed  not  to 
affect  the  fiscal  strength  of  spirits.  Spirits 
which  are  of  proof  strength  at  10*6®  are  conse- 
quently deemed  to  be  of  proof  strength  at  other 
temperatures,  and  the  same  applies  to  spirits  of 
any  other  strength,  provided  that  no  change  in 
composition  has  occurred.  In  computing  the 
strength  of  a  spirit  mixture  reference  is  made 
to  the  volume  of  proof  spirit  it  contains,  If  under- 
proof, or  will  produce  if  overproof,  at  the 
dominant  temperature,  which  for  revenue  pur- 
poses in  this  country  is  fixed  at  l(f  (50^F.). 
Ifendeleeff's  aloohd  is  thus  found  to  be  75*35 
overproof,  or  100  volumes  at  10®,  when  diluted 
with  water  to  proof  strength,  yield  175*36 
volumes  at  that  temperature. 

In  the  annexed  table  specific  gravities  of 
aqueous  alcoholic  mixtures  are  correlated  with 
peroentsges  of  idcohol  by  weight  and  by  volume, 
and  fiscu  proof  spirit.  The  specific  gravities 
are  reduced  to  air  values  ana  represent  the 
ratio  of  the  weight  of  a  given  volume  of  spirit 
to  the  weight  of  the  same  volume  of  watcnr  at 
16*6*  under  the  same  atmospheric  conditions ; 
they  may  be  converted  to  specific  gravities  in 
vacuum  by  means  of  the  expression — 

a  +  0*0012 

1*0012 

Although  it  is  probable  that  the  density  of  a 
spirituous  liquid  can  be  determined  more  accu- 


rately by  the  use  of  a  pyknometer  than  by  othei 
means,  in  practical  operations  where  regard 
must  be  had  to  convenience,  it  is  preferabk  to 
employ  one  of  the  many  hydrometers  or  alcoholo- 
meters, the  stems  of  which  are  variously  graduated 
to  show  densities,  percentages  of  alcohol  by 
weight  or  by  volume,  or  again  arbitrary  indica- 
tions which  can  bo  interpreted  by  suitable 
tables. 

Since  the  vear  1816,  Sikes'  hydrometer  has 
been  the  legal  instrument  for  ascertaininff  the 
stren|;th  of  spirits  for  revenue  purposes  in  Great 
Britain  and  Ireland,  as  well  as  in  most  of  the 
British  Colonies.  It  is  made  of  brass,  gilded, 
and  consists  of  a  hollow  sphere  provided  at  one 
pole  with  a  graduated  rectangular  stem  uniform 
m  section,  and  at  the  other  with  a  conical 
spindle  terminating  in  an  oval  counterpoise  to 
give  stability  to  tne  instrument  when  floating 
in  a  liquid,  and  also  to  serve  as  an  attachment 
for  various  poises.  The  graduated  portion  of 
the  stem  contains  ten  principal  divisions,  which 
are  equal  in  length,  and  marked  *0'  at  the 
upper,  and  *  10 '  at  the  lower  end,  and  between 
these  points  the  stem  is  again  subdivided  to 
2  tenths  of  a  division.  When  the  instrument  is 
floating  at  the  *  0 '  mark  in  spirit  at  a  tempera- 
ture of  15*6*,  it  indicates  a  strength  of  66*7 
overproof,  or  92*50  p.c.  of  alcohol,  whilst  the 
*  10  mark  corresponds  to  .a  strength  of  58 
overproof,  or  86-11  p.c.  of  alcohol  {by  weight). 
For  strengths  weaker  than  these  a  senes  of  nine 
poises  or  weishts  are  used,  numbered  consecu- 
tively from  10  to  90.  The  poises*  are  made  of 
hammered  brass,  gilded,  and  can  be  attached  by 
means  of  a  slot  in  the  poise  to  the  spindle  of 
the  hydrometer.  The  series  of  principal  divi- 
sions can  thus  be  repeated  ten  times,  reading 
from '  0 '  to  *  100,'  which  latter  indication  repre- 
sents distilled  water.  Sikes*  hydrometer  indica- 
tions refer  to  readings  on  the  stem  at  the  surface 
of  the  liquid  in  which  it  is  floating,  the  capillary 
meniscus  being  disregarded,  and  are  interpreted 
into  proof -strengths  by  means  of  tables  which 
are  arranged  so  as  to  identify  a  sample  of 
spirits  at  any  temperature  between  ~  1  *1*  (30*F. ) 
and  -f  37*8*  (100*F.). 

The  hydrometer  which  is  used  for  strong 
spirits  beyond  the  range  of  the  ordinary  Sikes^ 
instrument  is  known  as  the '  A '  or  *  Light  hydro- 
meter,' and  tables  proper  to  this  instrument  are 
also  issued.  It  is  made  of  brass,  gilded,  and 
graduated  on  the  stem  similarly  to  Sues'  hydro- 
meter. When  floating  at  the  *  0 '  mark  in 
spirit  at  a  temperature  of  15*6^,  it  indicates  a 
strength,  of  73*5  overproof,  or  98*24  p.e.  of 
alcohol,  whilst  the  '  10 '  mark  corresponds  to 
66*7  overproof,  or  92*50  p.c.  of  alcohol  by  weicLt, 
the  strength  proper  to  the  '  0 '  mark  on  Sifces' 
hydrometer. 

In  the  United  States  of  America  Tsalles' 
tables  are  leffaliflcd,  and,  as  in  Engluid,  revenue 
is  raised  with  reference  to  a  mixture  of  alcohol 
and  water  termed  '  proof.'  American  proof 
spirit  is  defined  as  containing  one-half  of  its 
volume  of  Tralles'  alcohol  at  15*6*.  For  Excise 
purposes  a  series  of  alcoholometers  are  employed, 
each  having  a  limited  range,  and  indicating 
percentages  of  proof  spirit — *0'  representing 
water,  *  100 '  proof  spint  and  *  200 '  alcohol — 
and  readings  at  temperatures  other  than  15*6* 
are  corrected  by  means  of  tables  to  what  they 


100 


ALOOHOLOMETRY. 


Indieatloii  of 
RIkdB*  hydro- 
meter  at  16-60 

Percentage  of 

Indication!  of  hydrometer  of 

BritiBhproot 

American 

proof 

spirit  at 

Alcohol 

by 
weight 

(Ger- 
many) 

Alcohol  by  TOlnme 

RoBBia 

Holland 

Spain 
(Gartter) 

Switxer^ 
land 

(Beck) 

atl6« 
CBtance) 

at  15-60 
(Trallee) 

Overproof 

A.O. 

73-5 

198*2 

98-2 

98-9 

99-1 

— 

26-3 

43-5 

42*6 

A.1. 

72-9 

197-6 

97-7 

98-6 

98-8 

"^ 

26 

43-2 

— 

A.2. 

72-2 

196-8 

97-2 

98*2 

984 

— 

— 

41-8 

A.3. 

71-6 

1961 

96-6 

97-8 

98-0 

— 

24-5 

-^ 

— 

A.4. 

71-0 

196-3 

96-1 

97-5 

97-7 

— 

— 

42-2 

40-9 

A.6. 

70-3 

194-6 

95-6 

97-1 

97-3 

— 

24 

— 

— 

A.e. 

69-6 

193-8 

94-9 

96-7 

96-9 

— 

^■^^ 

— 

— 

A.7. 

68-9 

193-0 

94-3 

96-3 

96-6 

— 

23-6 

41-2 

39-6 

A.8. 

68-2 

192-2 

93-7 

95-9 

96  1 

— 

— 

— 

m^^ 

A.9. 

67-6 

191-3 

93-1 

964 

96-6 

99-2 

23 

— 



A.10»0 

66-7 

190-4 

92-5 

96-0 

96-2 

98-3 

— 

40-1 

38-3 

1 

66-0 

189-6 

91-9 

94-7 

94-8 

— 

22-6 

— 

^- 

2 

65-2 

188-7 

91-3 

94-2 

94-3 

96-3 

— 

— 

— 

3 

644 

187-7 

90-7 

93-8 

93-9 

— 

22 

39-1 

37-1 

4 

63-6 

186-8 

90-0 

93-3 

934 

944 

— 

— 

— 

6 

62-8 

186-8 

894 

92-8 

92-9 

— 

21-5 

— 

— 

6 

61*9 

184-9 

88-8 

92-3 

924 

924 

— 

38-1 

85-8 

7 

611 

183-9 

88-1 

91-8 

91-9 

— 

21 

— 

— 

8 

60*2 

182-9 

87-5 

91-3 

914 

90-6 

— 

— 

34-9 

9 

69-3 

181-8 

86-8 

90-8 

90-9 

— 

20-5 

37-^ 

— 

10 

68*4 

180-8 

86-1 

90*3 

904 

88-6 

— 

— 

34-1 

11 

57-6 

179-9 

86-6 

89-9 

90-0 

— 

20 

— 

— 

12 

56-7 

178-9 

84-9 

894 

89-5 

86-6 

— 

36-2 

— 

13 

55-7 

177-9 

84-2 

88-8 

88-9 

— 

19-6 

— 

82-9 

14 

64*8 

176-8 

83-6 

88-3 

884 

84-6 

— 

— 

— 

15 

53-8 

176-7 

82-8 

87-7 

87-8 

— 

19 

36-2 

32 

16 

62-9 

174-6 

82-1 

87-2 

87-3 

82-6 

— 

— 

— 

17 

61-9 

1734 

814 

86-6 

86-7 

— 

18-6 

— 

— 

18 

60-9 

172-3 

80-7 

80-6 

86-1 

80-6 

— 

34-2 

30-8 

19 

49-9 

171-1 

80-0 

85*6 

85-6 

— 

18 

— 

— 

20 

48-9 

170-0 

79-3 

84-9 

86-0 

78-7 

— 

— 

30 

21 

47-9 

168-8 

78-6 

84-3 

844 

— 

17-6 

— 

— 

22 

46-8 

167-7 

77-9 

83-8 

83-9 

76-7 

— 

33 

-. 

23 

46-8 

166-6 

77-2 

83-1 

83-2 

— 

17-0 

.i— 

28-8 

24 

44*7 

165-3 

76-6 

82-5 

82-6 

74-8 

— 

— 

— 

26 

43-6 

164-0 

76-8 

81-9 

82-0 

— 

— 

32 

28 

26 

42-5 

162-7 

76-0 

81-3 

814 

72-8 

16-3 

— 

— 

27 

41-4 

161-6 

74-3 

80-6 

80-7 

— 

— 

— 

— 

28 

40*3 

160-2 

73-6 

80O 

80-1 

70-9 

16-9 

31-1 

26-8 

29 

391 

168-9 

72-8 

794 

79-5 

^ 

— 

— 

— 

30 

380 

167-6 

72-1 

78-7 

78-8 

68-9 

164 

— 

26 

31 

36-9 

166-3 

71-3 

781 

78-2 
77-6 

'— 

— 

301 

— 

32 

85-7 

166-0 

70-6 

774 

67 

14-9 

— 

— 

33 

34*6 

163-7 

69-9 

76-8 

76-9 

— 

— 

^- 

24-8 

34 

83-4 

1624 

691 

76-1 

76-2 

66 

14-5 

29-2 

— 

35 

32*2 

151-0 

684 

764 

76-5 

— 

^- 

— 

24 

36 

31-0 

149-6 

67-6 

74-7 

74-8 

63-1 

14 

— 

— 

37 

29-8 

148-2 

.66-8 

74-0 

74-1 

— 

— 

28-2 

23-2 

38 

28-5 

146-8 

66  a 

73-3 

734 

611 

13-6 

— 

— 

39 

27-3 

1464 

65-3 

72-6 

72-7 

— 

— 

— 

^~ 

40 

260 

144-0 

64-6 

71-9 

72-0 

59-2 

131 

— 

22 

41 

24« 

142-6 

63-8 

71-2 

71-3 

— 

— 

27 

— 

42 

23-6 

141-1 

63-0 

70-5 

70-6 

67-2 

— 

— 

— 

43 

22-8 

139-7 

62-2 

69-7 

69-8 

— 

12-4 

— 

20-9 

44 

21-0 

138-2 

614 

69-0 

691 

65-3 

— . 

26-1 

— 

45 

19-7 

136-7 

60-6 

68-3 

684 

— 

11-9 

— 

20-1 

46 

18*3 

136-2 

69-8 

67-5 

67-6 

63-3 

— 

— 

-» 

47 

17-0 

133-7 

69-0 

66-7 

66-8 

— 

11-6 

26-2 

— 

48 

15-6 

1321 

68-2 

65-9 

66-0 

51-3 

-^ 

-» 

18-9 

49 

14-3 

130-6 

674 

66-1 

65-3 

— 

11 

-^ 

-^ 

60 

12-9 

129-0 

66-6 

64-3 

64-5 

494 

— 

— 

— . 

61 

11-5 

1274 

66-8 

63-5 

63-7 

474 

10-5 

24 

17-8 

62 

10*1 

125*8 

66-0 

62-7 

62-9 

— 

ALCOHOLOMETRY. 


10] 


1 

IndietttoQ  of 
Silm'bydio- 
inaterAtlft-eP 

Percentage  ol 

Indicationa  of  hydrometer  of 

Britidi  proof 
■piilt 

American 

nroof 
spirit  at 

Alcohol 

by 
weight 
(Ger- 
many) 

Alcohol  by  volume 

SuBsia 

Holland 

Siiain 
(Oartier) 

Switxer- 

(Vrance) 

at  l5-«o 
(TraUes) 

land 
(Beck) 

OTerproof 

A.10=:63 

8-7 

124-2 

64-2 

61-9 

62-1 

— 

10-1 

— 

17 

M 

7-3 

122-6 

63-4 

61-1 

61-3 

45-6 

— 

23-1 

— 

M 

5-8 

120-9 

62-6 

60-2 

60*4 

— 

— 

— 

— 

66 

4-4 

119-2 

61-7 

69-4 

59-6 

43-5 

9-4 

— 

150 

57 

2-9 

117-6 

60-9 

68-6 

68-7 

— 

22-2 

— 

68 

1-4 

Underproof 

116-7 

60-0 

67-7 

670 

41-5 

9 

^■~ 

16-1 

69 

0-2 

1140 

40-2 

66-8 

67  O 

— 

— 

— 

— 

60 

1-7 

112-2 

48-3 

660 

66-1 

39-6 

— 

21-3 

— 

61 

3-3 

110-6 

47-6 

65  O 

65-2 

— 

8-3 

— 

14 

62 

4-8 

108-7 

46-6 

641  • 

54-3 

37-6 

— 

— 

— 

63 

6-4 

106-9 

46-8 

63-2 

53-4 

70 

—' 

13-3 

64 

81 

106-0 

44-9 

62-3 

52-6 

35-6 

— 

20-1 

— 

66 

9-7 

103-1 

440 

61-3 

61-6 

— 

— 

— 

— 

66 

11-4 

101-2 

43-1 

60-4 

60-6 

33-6 

7-2 

— - 

12-2 

67 

131 

99-3 

421 

49-4 

49-6 

— 

— 

— 

68 

U-9 

97-2 

41-1 

48-4 

48-6 

31-6 

6-8 

19 

— 

69 

16-7 

96-1 

40-2 

47-3 

47-5 

— 

— 

— . 

11 

70 

18-6 

93-0 

39-2 

46-3 

46-5 

29-7 

— 

— 

— 

71 

20-5 

90-8 

38-2 

46-2 

45-4 

— 

61 

18-1 

— 

72 

22-4 

88-6 

37-2 

44-1 

44-3 

27-7 

— 

— 

90 

73 

24-4 

86-4 

36-2 

43  O 

43-2 

5-7 

— . 

— 

74 

264 

84-2 

36-2 

410 

421 

25-7 

—^ 

— . 

— 

75 

28-5 

81-8 

341 

40-7 

40  0 

— 

160 

8-8 

76 

30-7 

79-4 

33-0 

39-5 

39-7 

23-7 

51 

— 

— 

77 

32-9 

76-9 

31-9 

38-3 

38-5 

— 

— 

~— 

8-1 

78 

36-3 

74-3 

30-7 

360 

37-1 

21-8 

— 

16  1 

— 

79 

37-7 

71-4 

29-6 

36-5 

35-7 

-^ 

4-4 

— 

— 

80 

40-3 

68-6 

28-2 

340 

34-2 

19-8 

— 

-^ 

7 

81 

42-9 

65-4 

26-9 

32-6 

32-7 

i^ 

40 

i— 

— 

82 

46-7 

62-3 

26-6 

310 

31-2 

170 

— — 

15 

— . 

83 

48-6 

68-9 

24-2 

29-3 

20-6 

— 

3-6 

— . 

6 

84 

61-7 

66-4 

22-7 

27-5 

27-7 

150 

— 

— 

— 

85 

64-8 

61-7 

21-1 

25-6 

25-8 

— 

— 

14-1 

— 

86 

68-2 

47-9 

19-6 

23-7 

23  O 

13  O 

30 

— 

40 

87 

61-5 

441 

180 

21-8 

22  O 

—-^ 

— 

-~ 

— 

88 

66-0 

40-2 

16-4 

190 

20-1 

110 

— 

13-3 

— 

.    80 

68-4 

36-2 

14-7 

ISO 

18-1 

— 

2-3 

—^ 

3-8 

90 

71-9 

32*2 

13  1 

160 

161 

90 

_ 

~~ 

— 

91 

76-2 

28-4 

11-5 

14-1 

14-2 

— 

10 

12-4 

31 

02 

78-4 

24-7 

lOO 

12-3 

12-4 

70 

—- 

-^ 

— 

03 

81*4 

21-3 

8-6 

10-6 

10-7 

— 

1-6 

— 

— 

94 

84-4 

17-9 

7-2 

80 

90 

6 

— 

11-6 

2-1 

95 

87-3 

14-6 

6-8 

7-2 

7-3 

— 

— 

— 

— 

96 

90O 

11-4 

4-6 

5-6 

5-7 

4 

OO 

V 

— . 

97 

02-6 

8-4 

3-4 

41 

4-2 

— » 

10-8 

1 

98 

961 

6-6 

2-2 

2-7 

2-8 

2 

^ 

— 

90 

97-6 

2-8 

1-1 

1-4 

1-4 

— 

^^ 

— 

— 

100 

100-0 

0-0 

ft 

~        % — 

OO 

OO 

OO 

0 

0 

10-1 

0-1 

would  be  in  the  same  spirit  at  that  temperature. 
In  comparing  American  with  British  proof  it  is 
necessary  to  remember  that  the  American  gallon 
is  smaller  than  the  British  Imperial  gallon, 
100  British  being  equivalent  to  ISK)  American 
gallons.  Consequentiy,  100  British  proof  gallons 
are  equal  to  137  American  proof  gallons. 

Similarly,  in  Holland  a  proof  standard  is 
recognised.  Dutch  proof  contains  60  p.o.  by 
volume  of  anhydrous  alcohol  at  16*.  As  in 
the  United  States,  a  series  of  alcoholometers 
aie  employed,  differing  only  in  regard  to  the 
ranf^  oif  their  strength  indications.    The  alco- 


holometer scale  is  dirided  into  28  prinoipa 
divisions  or  degrees,  which  are  equal  in  lengtb 
and  again  subdivided,  each  principal  divisioi 
representing  Ag  of  the  volume  of  the  instn 
ment  below  tne  zero  mark.  Spirit  tables  baaei 
on  the  results  of  Baumhauer's  investigation 
accompany  the  instruments  and  tranidat 
degrees  on  the  scale  into  percentages  of  alcohc 
at  15*  on  which  the  revenue  charge  is  based. 

In  Italy  TraUes'  alcoholometer  is  use 
officially.  This  instrument  is  made  of  glasi 
and  at  the  standard  temperature  of  15  HB 
directly  indicates  the  volume  of  alcohol  cor 


102 


ALCOHOLOMETRY. 


tained  in  100  volaoMS  of  ipirit  when  measured 
at  the  same  temperatura.  IndioationB  at  other 
temperatures  are  oorrected  by  means  of  tables 
to  true  percentages  by  volume  at  16 -6*. 

In  Austria-Hungary  an  alcoholometer  closely 
resembling  Tralles',  and  indicating  percentages 
of  alcohol  by  volume  at  16^  is  us^  Its  m- 
dications  are  uniformly  higher  than  those  of 
Tralles'  to  the  extent  of  from  one  or  two  tenths 
per  cent.  Reading  on  this  instrument  are  taken 
at  the  highest  pomt  of  the  capillary  meniscus, 
which  extends  1-2  mm.  on  the  stem  above  the 
normal  surface  of  the  liquid. 

TraUes'  alcoholometer  and  tables  are  used 
eommerciallvin  Russia,  but  for  Revenue  purposes 
a  metal  hydbometer  with  nine  poises  similar  in 
character  to  Sikes'  hydrometer  is  officiaL  On 
this  instrument,  however,  Sikes'  indications  aie 
reversed,  so  that  '  100 '  is  made  to  represent 
strong  spirit,  and  *  0 '  distilled  water.  The  hydro- 
meter scale  is  arbitrary,  and  indications  are  inter- 
preted into  percentages  by  volume  of  TraUes' 
alcohol  at  the  standard  tempeiature  of  10*6*. 

Previous  to  the  year  1887,  Tralles'  instrument 
was  also  used  in  Germany.  It  has  now  been 
replaced  by  a  svstem  of  weight  alcoholometry, 
based  on  MenaeldeflPs  data,  whereby  the  pro- 
portion bv  weight  of  alcohol  is  determined.  The 
official  alcoholometexB  axe  made  of  glass,  and 
graduated  to  show  percentages  of  alcohol  by 
weight  at  15* — apparent  percentages  at  other 
temperatures  being  converted  into'  true  peroent- 

rbv  means  of  tables.  Duty  is,  however, 
^ed  on  the  volume  of  anhydrous  alcohol  pre- 
sent in  a  spirit  when  measured  at  15  *6^  This 
system  is  therefore  analogous  to  the  British,  with 
the  exception  that  the  dominant  temperature  at 
which  Bntish  proof -strengths  are  computed  is  10*. 

In  France  Gay  -  Lussao's  original  volume 
alcoholometer  and  tables  have  been  oorrected 
to  the  new  values  for  densities  of  mixtures  of 
aloohol  and  water  determined  by  the  *  Bureau 
national  des  poids  et  mesures*  (1884).  The 
density  of  anhydrous  alcohol  at  16*/! 5^  is  given 
as  0*79433  in  vacuum,  as  against  0-7947  assumed 
by  Gay-Lussac,  and  the  difference  between 
the  graduations  of  the  old  and  new  of&cial 
instruments  reaches  a  maximum  of  0*4  p.c.  for 
spirits  containing  from  20  to  21  p.o.  of  alcohol 
by  volume.  Thus  20*  at  a  temperature  of 
15*  on  the  new  legal  centesimal  alcoholometer 
indicates  spirit  containing  20  p.c.  by  volume 
of  alcohol,  and  corresponds  to  20-4*  on  Gay- 
Lussao's  original  instrument.  The  French  spirit 
tables  indicate,  at  temperatures  extending  m>m 
0*  to  30*,  the  percentage  by  volume  of  alcohol 
which  a  liquid  contains  at  15*. 

Previous  to  the  adoption  of  Gay-Lussac's 
alcoholometer  and  tables  by  the  French  Govern-  I 
ment,  Cartier's  areometer  was  used  as  the 
Revenue  instrument.  Its  stem  is  graduated  from 
10  to  45  in  divisions  of  equal  length,  and  in- 
dicates the  concentration  of  a  spirituous  liquid 
by  arbitrary  degrees,  which  serve  as  spirit- 
strengths  for  charging  duty.  Cartier's  areometer 
is  still  used  in  Spain  and  South  America. 

In  Switzerland,  Beck's  hydrometer  is  used 
for  spirit  assaying,  and,  like  Cartier's  instrument, 
of  which  it  is  a  modification,  floats  at  the  lowest 
indication  in  distilled  water  at  12-5*  (10*R.). 

By  means  of  the  above  table  the  indica- 
tions of  any  one  of  these  instruments  at  15*6* 


can  be  converted  into  degrees  of  any  other,  and 
British  fiscal  strengths  compared  with  those  of 
other  eountries. 

An  indispensable  step  to  a  correct  assay  of 
spirit  is  the  removal  of  any  f oreisp  matter  which 
may  be  in  solution  in  the  alcohoQo  mixture.  In 
the  case  of  potaUe  spirits,  wines,  liqueurs,  &a, 
the  spirit  is  freed  from  saccharine  and  other 
dissolved  matter  by  distillation.  The  distilla- 
tion of  a  strong  spirituous  liquid  into  its  own 
volume  so  as  to  obtain  an  accurate  determina- 
tion of  the  amount  of  alcohol  present  is  im- 
practicable with  the  apparatus  and  the  methods 
of  distiUation  commonlV  used,  so  that  although 
it  is  possible  to  distil  without  loss  spirits  of 
underproof  strength  into  the  same  volume,  it  k 
necessary  to  dilute  overproof  spirits  and  distil 
into  two,  three,  or  four  times  tiie  original 
volume.  The  amount  by  which  the  true  alco- 
holic strength  of  brandy  or  rum  differs  from  the 
apparent  strength,  as  mdicated  by  the  hydro- 
meter or  a  density  determination,  is  termed  the 
*  obscuration.' 

In  the  case  of  medicinal  preparations,  flavour- 
ing essences,  &c.,  which  yield  distillates  con- 
taming  essential  oils  and  Volatile  substances, 
specisi  treatment  is  necessary  before  a  pykno- 
metrical  determination  of  spirit  is  possible. 
In  these  circumstances  the  sample  or  dis- 
tillate is  mixed  with  water  in  a  separator  so 
that  the  mixture  shall  contain  not  more  than 
20-25  p.c.  by  volume  of  aloohol,  and  common 
salt  i^  added  in  quantity  sufiBcient  to  saturate 
the  liquid.  The  mixture  is  then  shaken  vigor- 
ously with  50-100  C.C.  of  light  petroleum,  and 
after  remaining  a  short  time,  the  aqueous  layer 
is  extracted,  if  necessary,  a  second  time  with 
petroleum  (for  instance  when  chloroform  or 
ether  is  present),  and  finally  drawn  off  into  a 
flask  and  distilled.  In  the  case  of  soap  lini- 
ments and  similar  preparations,  dilute  sulphuric 
acid  is  used  instead  of  salt,  and  the  aliphatic 
acids  and  volatile  matters  removed  by  petroleum 
before  distilling  (Chem.  Soc.  Trans.  1903,  314). 
Preparations  containing  iodine  are  decolourised 
with  sodium  thiosulphate,  and  excess  of  .caustic 
soda  added  to  prevent  decomposition  of  the  tetra- 
thionate  during  distillation.  Similarly,  volatile 
acids  must  be  neutralised,  and  ammoniacal  liquids 
distilled  from  dilute  sulphuric  acid  solution. 

For  the  estimation  of  ethyl  alcohol  in  fusel 
oil,  or  liquids  containing  fusel  oil,  the  salt- 
petroleum  process  may  he  employed,  but  as 
the  hiffher  alcohols  cannot  be  wholly  elimi- 
nated by  this  method,  the  specific  refraction 
of  the  distillate  is  determined  by  the  Zeiss 
Immersion  Refraotometer.  The  refractions  of 
mixtures  of  e|;hyl  alcohol  and  water  have  been 
determined  at  various  temperatures  by  Wagner 
and  Schultze  (Zeitsch.  anal.  Chem.  1907,  508) 
and  others,  and  a  near  approximation  to  the  true 
alcoholic  content  of  a  fusel  oil  mixture,  treated 
as  above  described,  can  be  obtained*  by  applying 
to  the  apparent  percentage  by  volume  of  alcohof, 
as  indicated  by  the  density  of  the  distillate,  a 
subtractive  correction  of  0*5  p.c.  for  each  deeree 
of  difference  between  the  re&actometer  rea£ng 
as  found  at  15*6*,  and  that  required  for  a 
mixture  of  ethyl  alcohol  and  water  oorrespond- 
ing  to  the  ascertained  density.  This  method  of 
eliminating  foreign  matters  in  spirit  assaying, 
from  a  knowledge  of  their  influence  on  the  specifio 


ALDEHYDE. 


10^ 


refractions  of  aqueous  aloohdio  mixivresy  is  I 
capable  of  wide  applioation,  and  has  been  atilised, 
for  instance,  by  Leach  and  Lythffoe  (Amer.  Chem. 
J.  1906,  964)  for  determinin|[  the  proportion  of 
methylated  spirits  in  a  spiritoous  liquid  (v. 
RBVBAOTOlOnB).  J.  H. 

ALCORNIM  or  ALOOBNOL.  An  aloohol, 
C|,HmO,  of  the  nature  of  phytoeterol,  found  in 
Aloomoco  bark  (Uartwich  and  Dunnenberger, 
Arch.  Pharm.  1900,  34  i). 

ALOO¥IN01IETEB.  An  instrument  for  de- 
termining the  alcoholic  content  of  a  wine  by 
observing  its  ascent  in  a  capiUary  tube. 

ALDEHTDB,  AreiaUehyie  Cfifi  on 
CH,*GHO.  A  product  of  the  oxidation  of 
ordinary  (ethyhc)  alcohol.  Aldehyde  ooouis, 
together  with  its  polymerides  metaldehyde  and 
paraldehyde,  in  the  *  first  runnings*  from  the 
stills  in  the  rectification  of  alcohol  which  has 
been  filtered  through  charcoal  (Kramer  and 
Pinner,  Ber.  2,  403 ;  4,  787 ;  Johnson,  J.  Soo. 
Chem.  Ind.  8, 57  ;  Hewitt,  ibid.  21, 97) ;  the  beet 
yield  is  obtained  from  the  alcohol  manufactured 
from  potatoes  and  from  the  sugar  beet.  It 
is  also  present  in  crude  wood  spirit  (Kr&mer 
and  Qrodzki,  Ber.  9,  1921) ;  in  crude  petroleum 
(Bobinson,  J.  Soo.  Chem.  Ind.  18,  232) ;  in  wine 
during  the  process  of  seeing  (Trillat,  Compt. 
rend.  136,  171 ;  idem,  Ann.  Inst.  Pasteur,  22, 
704,  753,  876 ;  idem.  BuU.  Soo.  chim.  5,  546, 
550 ;  7,  71) ;  and  in  certain  circumstances  in 
the  fermentation  products  of  alcohol  (Trillat, 
Compt.  rend.  146,  645 ;  Trillat  and  Souton,  146, 
996 ;  Kayser  and  Demolon,  146,  783 ;  Trillat 
and  Souton,  Bull.  Soc.  chim.  7,  244  ;  Aim.  Inst. 
Pasteur,  24,  302 ;  Kostyohev,  Zeitsch.  physiol. 
Chem.  79,  130 ;  83,  93 ;  89,  367 ;  92,  402 ; 
Biochem.  Zeitsch.  64,  237;  Kostyohev  and 
Hubbenet,  Zeitsch.  physiol.  Chem.  79,  359 ; 
85,  408 ;  Neubey  ana  Kerb,  Biochem.  Zeitsch. 
43,  494 ;  64,  251 ;  Ber.  47,  2730 ;  Grey,  Bio- 
chem. J.  7, 359 ;  Buchner,  Langheld,  and  Skraup, 
Ber.  47,  2550 ;  Miiller-Thurgan  and  Osterwald, 
Am.  Chem.  Abstr.  1916, 2274, 2474).  According 
to  Battelli  and  Stem  (Compt.  rend.  boc.  biol.  68, 
5)  it  is  produced  in  animal  tissues  by  oxidation 
of  alcohol  through  the  action  of  alooholase. 
It  occurs  in  poplar  blossoms  (tCostvohev, 
Hiibbenet,  and  Sheloumov,  Zeitsch.  physiol. 
Chem.  83,  105),  and  by  oxidation  of  certain 
substances,  such  as  ihamnose  (Roaenthaler, 
Arch.  Pharm.  251,  587).  Kerbosch  (Rec.  trav. 
chim.  34,  235)  showed  the  presence  of  traces  of 
aoetaldehyde  in  the  latex  oi  Hevea  brazilienHs. 
It  is  possibly  also  a  degradation  product  of 
glucose  in  the  animal  body,  and  may  oe  reduced 
to  alcohol  by  the  liver  (ef.  Embden  and  Baldes, 
Biochem.  Zeitsch.  45, 157). 

Aldehyde  is  also  formed  when  calcium  formate 
is  heated  with  calcium  acetate  (Limpricht, 
Annalen,  97,  369),  and  when  lactic  acid  and  the 
lactates  are  distflled  with  manganese  dioxide 
and  sulphuric  acid  (Stadeler,  Annslen,  79,  333) ; 
or  by  tne  action  of  dilute  sulphuric  acid  alone 
on  lactic  acid 

CH,CH(OH)COOH  =  CH.CHO+HCOOH 

(Erlenmeyer,  Zeitsch.  f.  Chemie,  1868,  343),  a 
process  used  commercially  at  one  time  for  the 
production  of  aldehyde  u>r  the  preparation  of 
Aldehyde  Green.    It  is  also  one  of  the  products 


of  the  dry  distillation  of  sugar  ( Volckel,  Annal^n^ 
87,  303). 

PnpainUion. — Aldehyde  is  formed  by  the 
oxidation  of  alcohol  by  means  of  platinum 
black  (Dobereiner,  Gm.  8,  274),  of  manganese 
dioxide  and  sulphuric  add  (Liebiff,  Annalen,  14, 
133),  of  potassium  dichxomate  ana  sulphuric  acid 
(Stadeler,  J.  1859,  329),  of  metallic  oatalysers 
(Bouveault,  Bull.  Soc.  chim.  1908,  3,  117; 
Sabatier  and  Senderens,  Compt.  rend.  136,  738), 
or  when  alcohol  ia  passed  through  an  iron  tulM 
heated  to  710M50^  (Ipataeff,  Ber.  34,  596). 

According  to  Lans  (J.  Soo.  Chem.  Ind.  22, 
571),  the  most  useful  oxidising  agents  for 
oonverting  alcohol  to  aldehyde  are  the  manganic 
salts.    When   prepared    by    liebif's   method, 

2  parts  of  80  p.o.  alcohol  are  neated  with 

3  parts  of  manganese  dioxide,  3  parts  of 
sulphuric  acid,  and  2  parts  of  water,  and 
the  distillation  carried  on  until  the  distillate 
begins  to  show  an  add  reaction;  this  point 
is  reached  when  about  three  paita  have  col- 
lected in  the  well-cooled  reoeiyer.  The  dis- 
tillate containing  alcohol,  aoetal  and  ethereal 
salts  is  then  distilled  with  an  eaual  weight  of 
calcium  chloride,  and  1)  parts  ooUeoted ;  this  is 
Batdn  rectified  with  an  equal  weight  of  calcium 
chloride  and  }  part  distilled  over.  The  product 
so  obtained  is  nearly  anhydrous,  but  still  contains 
aloohol  and  small  quantities  of  ethoeal  salts ; 
to  free  it  from  these,  it  is  dissolved  in  2  vols,  of 
ether,  saturated  with  ammonia  in  the  cold,  and 
the  aldehyde-ammonia  which  separates  is  col- 
lected, dissolved  in  water,  distilled  with  dilute 
sulphuric  acid  in  a  water-bath*  and  the  distillate 
rendered  anhydrous  by  rectification  over  calcium 
chloride  at  as  low  a  temperature  as  possible. 

Improved  methods  and  apparatus  for  oxi- 
dising alcohol  into  aldehyde  are  described  by 
Boult,  Eng.  Pat.  3998,  1896;  J.  Soc.  Chem. 
Ind.  15,  668 ;  Foumier,  Eng.  Pat.  7887,  1897 ; 
J.  Soc.  Chem.  Ind.  16,  695. 

Ethylene  oxide  ((3h,),0  (the  anhydride  of 
fflycol)  yields  aoetaldehyde  on  heatmg  (Nef, 
Annalen,  335,  201),  particularly  in  presence  of 
aluminium  oxide  at  200*^  C.  (Ipatieff  and  Leonto- 
witsch,  Ber.  36,  2017). 

It  is  also  produced  by  treating  ethylene 
glycol  with  Fenton^s  reasent,  or  by  treating 
ethylene  diamine  with  mtrous  acid  (Neuberg 
and  Rewald,  Biochem.  Zeitsch.  67,  127),  and 
from  pyruvic  acid  by  heating  to  150^  C.  with 
dilute  sulphuric  acid  (Beilstein  and  Wiegand, 
Ber.  17,  841) 

CHjCOCOOH  =  CH,CHO+CO, 

A  process  claimed  by  the  Fabrique  de  Pro- 
duits  de  Chimie  On;,  de  Laire  (Eng.  Pat.  5533, 
1913)  GonsLsts  in  heating  ethyl  halide  with 
hexamethylenetetramine  or  formaldehyde  and 
ammonia. 

Various  aliphatic  acids,  such  as  succinic, 
glyceric,  maleic,  fumaric,  tartaric,  crotonic,  &c., 
yield  aoetaldehyde  on  treatment  with  Fenton*s 
reagent  in  sunlight  (Neuberg,  Biochem.  Zeitsch. 
67,  50).  Behrens  (D.  R.  P.  276764)  describes 
the  production  of  acetaldehyde  by  mixing  the 
gases  obtained  by  distilling  coal,  wood,  tur^  &c., 
with  5-6  p.  c.  of  carbon  dioxide  and  heating  the 
mixture  for  some  time.  Snellinff  (U.  S.  Pat. 
1124347)  claims  the  production  of  aldehyde  by 
passing  the  vapour  of  ethyl  alcohol  into  a  porous 


104 


ALDEHYDE. 


earthenware  tube,  which  may  be  lined  with 
platinum  or  palladium,  heated  to  about  800°,  and 
drawing  off  tne  hydrogen  produced  in  the  reaction 
which  diffuses  through  the  walls  of  the  tube ; 
the  emoval  of  the  hydrogen  allows  the  reaction 
to  proceed  more  nearly  to  completion. 

The  mopt  convenient  laboratory  method  is 
that  of  Sabatier  and  Senderens  (l.c),  by  passing 
alcohol  vapour  over  metallic  copper  heated  to 
about  300*^  C.  (c/.  also  Eng.  Pat.  17259,  1911). 
Aldeihyde  is  also  formed  to  some  extent  by 
heatinff  charcoal,  saturated  witlv  acetylene,  to 
360°  0.  with  water  (Degr^,  Ann.  Chim.  Phys. 
17]  3,  216). 

Commercially,  aldehyde  can  be  obtained 
from  the  *  first  runnings*  of  the  alcohol  stills. 
A  special  form  of  stiU  in  which  the  separation 
of  aldehyde  from  alcohol  is  brought  about  during 
the  rectification  of  the  latter  is  figured  and 
described  by  Galland  (Dingl.  poly.  J.  269,  226). 

Production  from  Acetylene. — ^Within  the  last 
few  years  the  commercial  production  of  acet- 
aldehyde  from  acetylene  has  become  increasingly 
important,  thereby  offering  new  routes  for  Uie 
production  of  eth}^  alcohol,  acetic  acid,  acetone, 
and  so  on.       .      ' 

This  process  depends  on  the  discovery  of 
Kutscherow  (Ber.  14,  1640;  17,  13),  that  in 
the  presence  of  mercury  salts,  such  as  mercuric 
chloride,  acting  as  catalysts,  acetylene  reacts 
with  water  to  give  acetaldehyde : 

CH:  CH+H,0  =  CH.CHO 

This  result  appears  to  be  due  to  the  inter- 
mediate formation  of  a  compound 

(CJlHg),iCCHO 

(triohlormerouriacetaldehyde),  which  is  split  up 
by  water  to  form  mercuric  chloride  and  acetalde- 
hyde (Kutscherow,  Z.c. ;  42,  2769;  Reiser, 
Amer.  Chem.  J.  16.  537  ;  Biginelli,  Chem.  Zentr. 
1898,  I  926;  Hofmann,  Ber.  31,  2212,  2783; 
32,  874 ;  37,  4469 ;  38,  663 ;  Hofmann  and 
Kirmreuther,  Ber.  41,  314  ;  42, 4232 ;  BUU  and 
Mumm,  Ber.  37,  4417 ;  38,  133 ;  Annalen, 
404,  219 ;  Brame,  Trans.  Chem.  Soc.  87,  427 ; 
Erdmaon  and  Kothner,  Zeitsch.  anoig.  Chem. 
18,  48 ;  B^hal,  Ann.  Chim.  Phys.  [6]  16,  267). 

Aooordins  to  Hofmann  {l,c.)  the  compound 
formed  has  uie  structure : 

a— Hg/wNa 

and  is  formed  by  the  addition  of  two  molecules 
of  mercuric  chloride  to  one  of  mercuric  carbide 
HgC,,  which  is  then  split  up  by  water : 

(OHg), :  C-C  :  a,+2Ha+H,0 

V/  =3Hga,+CH,CH0 

(cf.  Soc.  Anon,  nouvelle  TOyonnith,  Fr.  Pat. 
420436).  (For  further  details  see  Acxttlbnx.) 
The  first  EnffUsh  patent  dealing  with  the 
matter  is  bv  the  Chem.  Fab.  Griesheim  Elektron 
(Bog.  Pat.  29073, 1910),  according  to  which  aide- 
oyde  and  its  polymerisation  jpnKlttcts,  such  as 
paraldehyde  and  orotonio  ^dehyde,  are  produced 
by  the  reaction  of  acetylene  with  a  solution  of  a 
roereniy  salt  in  an  organic  or  inorganic  acid  at 
a  temperature  below  70^  G.    Such  suiuble  acids 


are  sulphuric,  phosphoric,  acetic,  ohloraoetio,  &a, 
the  use  of  45  p.c.  sulphuric  acid  inixed  with 
mercuric  oxide  is  also  recommended  at  tempera- 
tures below  70°.  The  (consortium  f .  Elektroohe- 
mische  Industrie  (Eng.  Pat.  6000, 1913)  describe 
a  modification  consLsting  in  pissing  acetylene 
through  sulphuric  acid  solutions  of  mercury 
oxides  containing  not  more  than  60  parts  SO  4 
in  1000  parts  of  water,  and  working  at  tempera- 
tures over  70°  0.  The  aldehyde  formed  custiU 
off,  and  mercury  is  depositea  at  the  bottom  of 
the  liquid ;  the  patent  also  describes  an  electro- 
lytic process  for  reoxidislng  the  mercury  which 
is  gradually  deposited  by  reduction  during  the 
process.  The  same  firm  later  (Eng.  Pat.  16848, 
1913)  claim  a  process  in  which  an  excess  of 
acetylene  is  passed  through  the  catalytic  solution, 
the  aldehyde  formed  is  carried  away  in  the  gas 
stream,  from  which  it  is  then  removed,  and  the 
acetylene  passed  back  to  the  catalyst. 

Bayer  &  Co.  (Eng.  Pat.  6627,  1914),  (void) 
claim  a  process  similar  to  the  foreaoing,  bat  in 
which  the  sulphuric  acid  ia  replaced  oy  an  oiganic 
sulphonic  acid,  such  as  the  siUphonie  acids  of 
benzene,  o-chlorphenol,  naphthalene,  or  the 
corresponding  di-  or  ta-  smphonic  acids,  &c. 
The  chief  purpose  of  using  sucn  acids  is  to  avoid 
the  condensation  and  polymerisation  of  the 
acetaldehyde  caused  by  prolonged  action  of 
stronger  acids  such  as  sulphuric. 

Chem.  Fab.  Griesheim  Elektron  (Eng.  Pat. 
15669,  1914)  describe  the  use  of  a  20-35  p.c. 
acid  inixed  with  a  mercury  salt,  the  temperature 
being  kept  below  the  boiling-point  of  the  acid ; 
sulphuric,  phosphoric,  or  organic  sulphonic 
acids  are  specified  as  suitable. 

G.  Boiteau  (Eng.  Pat.  16919, 1914),  in  dealing 
with  the  production  of  a  catalytic  liquid,  pro- 
duced by  dissolving  a  mepcurio  salt  in  a  suitable 
solvent  and  then  lorming  the  sulphate  in  situ 
by  the  addition  of  sul^niie  acid,  is  chiefly 
concerned  with  the  production  of  ethylidene 
diacetate. 

A  further  improvement  claimed  by  the  Con- 
sortium (Eng.  Pat.  16967, 1914)  consists  in  passing 
an  excess  of  acetylene  through  a  hot  solution 
containing  mercury  compoun<u  and  so  adjusting 
the  conditions  that  a  state  of  thermal  equJUbrium 
Lb  approximately  attained.  This  is  carried  out 
by  adjusting  the  rate  of  flow  of  the  gas  and  the 
temperature  of  the  reaction  vessel,  so  that  the 
heat  evolved  by  the  reaction  is  balanced  by 
the  heat  lost  by  evaporation  of  water  and  by 
addition  of  fresh  water  to  keep  the  volume  of 
liquid  constant;  the  reaction  may  be  earned 
out  in  thermally  insulated  if«ssels  surrounded  by 
a  water  jacket;  a  temperature  of  80'  is  said 
to  be  suitable,  using  sulphuric  acid  of  6-36  p.c. 
strength. 

H.  W.  Matheson,  of  the  C!anadian  Electro- 
products  Company,  describes  a  process  which 
consists  in  passing  acetylene  in  excess  into 
sulphuric  acid  of  6  p.c.  strength  containinflr 
mercuric  oxide  in  suspension,  at  40-66°  C.  and 
at  pressures  varying  from  atmospheric  to  3-4  Ibii. 
above :  the  process  is  made  continuous  by  the 
periodic  addition  of  the  necessaiy  amounts  of 
water,  acid  and  mercuric  oxide.  (Eng.  Pat. 
132667.) 

To  overcome  the  difficulty  caused'  by  the 
gradual  separation  of  mercury  as  a  heavy  sludge, 
which  is  difficult  to  deal  with,  Meister,  Lucius^ 


ALDEHYDE. 


105 


and  Bruning  (Eng.  Pat.  24153, 19U)  suggest  the 
introdoction  of  suitable  ozidiiBng  araits  to  the 
reaction  liquid,  sach  as  ferrio  sMis,  ohromio 
add,  or  nhfomntwi,  to  prevent  the  separatioii  of 
metallio  merouiY  (ef.  U&  Pftt.  1 1510^  1 151929; 
D.  R.  P.  293070). 

A  method  for  overcoming  this  tronUe  is 

given  by  T.  P.  Hilditch  and  J.  Grosfield  and 
ons  consisting  in  the  periodic  addition  of  small 
amoonta  of  saitable  oxidising  agenta  such  as 
manganates,  permanganates  or  hydro^n  per- 
oxide to  raoxidiae  the  sludge  to  meroano  oxide. 
(Eng.  Pats.  124702,  125026.)  Lead  peroxide, 
eerie  oxide  and  manganese  dioxide  are  also 
claimed  <Eng.  Pat.  131086). 

The  Consortinm  (Eng.  Pat.  5132, 1915)  state 
that  satiflfactocy  resolte  are  obtained  by  the 
use  of  solvents,  such  as  glacial  acetic  acid,  mixed 
or  not  with  vinyl  acetate,  ethylidene  diacetate, 
&C.,  in  the  presence  of  mercuric  oxide  and 
strong  adds ;  water  is  added  in  the  theoretical 
proportions  and  the  temperature  kept  at  80^- 
90°.  The  use  of  iron  or  mckel  apparatus  is  also 
suggested. 

The  diffioultv  caused  by  the  formation  of 
the  mereuiy  Biudu[e  is  also  discussed  by  the  CShem. 
Fab.  Griesheim  £lektron(Eng.  Pat.  10140, 1915), 
who  claim  the  recovery  of  the  mercury  by 
carbonising  the  residue  by  heat,  or  by  mixing 
the  sludge  with  caustic  soda  and  electro- 
lysing. 

^uie  Soa  Chem.  Ind.  in  Bade  regenerate  the 
catalyst  by  electrolysis  in  presence  of  a  suitable 
oxygen-carrier  such  as  an  iron  salt  (Eng.  Pat. 
130138). 

H.  Drevfus  (Eng.  Pat.  105064),  in  a  somewhat 
lengthy  claim,  states  that  the  production  of 
acetaldehyde  is  conveniently  carried  out  by 
observing  one  or  more  of  the  following  condi- 
tions:— 

(1)  Sulphuric  add  is  employed  of  5>20  p.c. 
(2)  Lees  t&ui  20  p.c.  of  mereury  compounds  are 
used.  (3)  The  temperature  is  kept  below  60"  0. 
(4)  The  acetylene  is  rapidly  introduced  in  such 
quantity  tliat  it  is  all  absorbed.  (5)  The 
acetylene  is  at  first  introduced  slowly  until  all 
the  mercury  compound  becomes  grey  or  greyish- 
black.  (6)  After  a  quantHry  of  aldehyde  has 
been  formed  the  introduction  of  acetylene  is 
stopped  and  the  temperature  nused  to  distil  off 
the  aldehyde,  after  which  the  temperature  is 
again  lowered  and  more  acetylene  mtroduced. 
(7)  The  acetylene  is  previously  purified  from 
sulphuretted  hydrosen,  phospnine,  ammonia, 
&0.  (8)  Water  is  added  throughout  the  reaction 
to  keep  tlie  percentage  of  acid  constant.  (9) 
The  absorbing  solution  is  first  heated  up  to 
dissolve  all  the  mercury  compounds  and  then 
cooled  to  the  temperature  suitable  for  the  re- 
action. (10)  The  mixture  of  gas  and  liquid  is 
strongly  agitated,  and  the  acetylene  is  intro- 
duced under  alight  pressure;  in  place  of  sulphuric 
acid  other  aci<u,  such  as  benzene  sulphomo  acid 
or  phosphoric  add,  may  be  used.  The  aldehyde 
may  be  removed  from  we  solution  by  evacuation 
or  Dy  solvents  such  as  acetylene  or  ethylene 
chlorides  or  benzene,  instead  of  by  distillation. 
The  mercury  residue  may  be  regenerated  by 
treatment  with  suitable  oxidising  agents;  the 
process  may  be  carried  out  in  Imd-uned  appa- 
ratus, the  surface  of  which  is  previously  coated 
with  a  layer  of  lead  sulphate,  or  iron  apparatus 


lined  with  add  resisting  plates  or  earthenware 
may  be  used.  The  use  of  suitable  heating  and 
cooling  pipes  it  also  described.  The  same 
inventor,  in  a  patent  of  addition  to  the  above 
(Eng.  PM.  106483),  claims  a  modification  of  the 
mndpal  proceos,  using  sulphuric  add  of  over 
20  p.a  strength  and  extracting  the  aldehyde 
by  means  of  a  solvent  such  as  derivatives  of 
acetylene,  ethylene^  or  benzene. 

Dreyfus  auo  daima  the  use  of  iran-aiUoon 
alloy  vessels  for  the  process,  which  are  resistant 
to  hot  dilute  sulphuric  add  and  to  the  action  of 
mercury  (Eng.  Pat.  115899). 

In  Eng.  Pat.  107584,  the  Deutsche  Qold  and 
Silber  Sohdde  Anstalt  describe  a  distinctly 
different  process,  ocmaisting  in  passing  a  mixture 
of  acetylene  and  steam  over  contact  agents, 
such  aa  molybdic  add  on  aabestos,  at  high 
temperatures ;  somewhat  similar  is  the  propoMd 
of  Chemi8che'FabrikRhenania(]^.  Pat.  109983), 
to  pass  acetylene  and  steam  over  bog-iron  ore 
at  400''-420'' ;  in  place  of  bog-iron  <ne,hydrated 
iron  oxide,  bauxite,  hydrated  aluminium  silicates, 
or  compounds  of  copper,  nickel,  cobalt^  manga- 
nese, chromium,  cerium,  or  vanadium  may  oe 
used.    (C/.  also  Eng.  Pat.  107585.) 

Of  later  developments  we  may  note  that 
Hibbert  and  Morton  (U.S.  Pats.  1213486; 
1213487;  1247270;  CJan.  Pats.  181655 ;  181656; 
181657)  recommend  the  introduction  into  the 
catalytic  meroury  solution  of  a  salt  of  a  weak 
add,  specifically  a  borate;  the  absorption  of 
the  acetylene  and  the  distillation  of  the  acetalde- 
hyde is  said  to  be  more  rapid  and  complete,  and 
the  tendency  to  the  formation  of  undesirable 
by-product's  is  said  to  be  greatly  reduced.  They 
also  claim  the  use  of  sevena  catalytic  baths 
arranged  in  series  so  that  the  vapours  pass 
through  them  all  in  succession. 

The  0)mp.  des  Plraduits  chim.  d'Alais,  in 
Eng.  Pat.  130650,  describe  the  production  of 
acetaldehyde  from  acetylene  in  an  apparatus  in 
which  the  reaction  liquid  is  subjected  con- 
tinuously to  a  vacuum  so  as  to  remove  the 
aldehyde  as  formed. 

As  actually  carried  out  on  the  large  scale  at 
the  Shawinigan  works  of  the  Canadian  Electro- 
products  Co.,  acetylene  gas  is  led  into  dilute 
sulphuric  add  containing  meroutio  oxide  in 
suspension,  the  oxide  bdng  led  in  continuously 
and  the  acetaldehyde  removed  by  the  lar^e 
excess  of  acetylene  used :  the  requisite  oxide  is 
prepared  by  electrolysing  mercury  in  laige  cast- 
iron  pots  o  ft.  in  diameter  and  15  ins.  high, 
using  the  mercury  as  the  anode  and  dilute 
caustiic  soda  as  the  electrolyte.  (Can.  Chem. 
J.  III.  260  (1919).) 

Substituted  acetaldehydes  applicable  to  per- 
fumery can  be  obtained  by  condensing  a  ketone 
with  a  halogen  or  amino  substituted  acetic  ester 
in  the  presence  of  sodium.  The  a-hydroxy- 
acrylic  ester  thus  obtained  is  saponified  and 
decomposed  by  heat  or  distillation  under  reduced 
pressure  (J.  Soc.  Chem.  Ind.  23,  455). 

Propertits. — ^Aldehyde  is  a  colourless  liquid 
b.p.  20-8%  m.p.  -120-7°,  and  sp.gr.  0-80092 
at  0""  (Kopp,  Annalen,  64,  214) ;  079509  at  10"*, 
0-79138  at  13^  078761  at  16*»  (Perkin,  Chem. 
Soc.  Trans.  45,  475).  It  has  an  extremely 
puneent  suffocating  odour;  it  is  very  inflam- 
mable, and  bums  with  a  feebly  luminous 
flame. 


106 


ALDEHYDE. 


It  is  soluble  in  all  proportions  in  alcohol, 
ether,  and  water,  and  is  separated  from  the 
aqoeouB  solution  as  an  ethereal  layer  on 
addition  of  caldum  chloride.  It  possibly  forms 
an  addition  compound  with  water 

CH.-CHO+HjO  «  CH,<!H(OH), 

UUdehydrol;  eUtylidene  glycol)  (Ramsay  and 
Young,  Trans.  Boy.  800.  1886, 1.  117 ;  Perkin, 
Trans.  ChenLSoc.  51, 815;  Binot  and  Pickering, 
ibid.  71,  774 ;  Homfray,  ibid.  87,  913  ;  GoUes, 
ibid.  89,  1249).  When  heated  with  aqueous 
soda,  potash,  or  barium  hydroxide,  so-caUed 
aldehyde  xesin  is  obtained  as  a  brown  mass 
(Liebig,  l.c. ;  Weidenbusch,  Annalen,  66,  153 ; 
Lederer,  Monatsh.  22,  536).  Sodium  amalgam 
converts  aldehyde  into  ethyl  alcohol,  a  smaH 
quantity  of  i§-butylenfifflyool,  which  is  also 
formed  by  the  action  of  magnesium  amalgam 
(Meonier,  Gompt.  rend.  134,  473 ;  Tiitschenko 
and  Qrifforeeff,  J.  Buss.  Phys.  Qiem.  Soc.  38, 
540;  Yoronkoff,  ibid.  38,  547),  being  formed 
simultaneously  (Kekul^,  Annalen,  162,  310). 
With   sodium,   aoetaldehyde  reacts   violently. 


place  m  presence 
of  benzoyl  chloride  in  ethereial  solution  aide- 
hydoaldolbenzoate  0,,H|«04,  m.p.  86°-87%  is 
formed  (Freer,  Amer.  Chem.  J.  18, 552  ;  Annalen, 
293,  326).  Phosphorus  pentachloride  reacts 
with  it,  yielding  etbylidene  dichloride  (Geuther, 
Annalen,  105,  323).  With  potattium  cyanide 
alanine  and  a-imino  dipropionic  acid  are 
formed  (Franzen  and  Byser,  J.  ex.  Chem.  88, 
293). 

BeducHon  of  Aldehyde. — ^In  presence  of 
reduced  nickel  hydrogen  reduces  aldehyde 
to  ethyl  alcohol,  a  good  yield  and  pure 
product  beinff  obtained  (Sabatier  and  Senderens, 
Compt.  rena.  137,  301).  Modifications  of 
tins    process     have    been    worked     out    and 

Satented.  Thus,  H.  Dreyfus  (Eng.  Pat.  108856) 
escribes  the  production  of  ethyl  alcohol  by 
the  action  of  hydrogen  on  acetaldehyde  in  the 
presence  of  suitable  catalysts  such  as  platinum, 
platinised  asbestos,  copper,  iron,  cnromium, 
nickel,  cerium,  uranium,  vanadium,  and  their 
oxides,  &a  The  reaction  is  carried  out  by 
passing  the  mixture  of  hydrqgen  and  aldehyde 
vapour  through  reaction  vessels  or  tubes  at 
temperatures  ranging  from  the  boiling-point  of 
aldenyde  to  400^  C.,  and  condensing  the  product. 
The  Elektrizit&ts  Werke  Lonza  (Swiss  Pat. 
74129,  1917)  claim  the  production  of  alcohol  by 
pbBsing  aldehyde  vapour  and  a  large  excess  of 
nydrogen  over  a  heated  catalyst  (Eng*  Pat. 
120163;  cf.  also  128929).  It  is  understood 
that  the  last-named  firm  has  been  granted 
a  concession  from  the  Swiss  Government  to 
manufacture  7000  tons  of  alcohol  a  year  from 
calcium  carbide  at  their  works  at  Visp  in  the 
Bhone  Yalley,  and  aro  to  supply  not  less 
than  2500  tons  alcohol  to  the  Government 
J.  Ind.  and  Eng.  Chem.  1917,  903).  An 
acetic  acid  factory  is  also  being  constructed  at 
Wallis. 

For  the  production  of  one  ton  of  alcohol  by 
this  process  about  one  ton  calcium  carbide  is 
necessary,  and  500  cubic  metres  of  hydrogen; 
the  former  requires  some  8000  kw.  hours  and 
the  latter  about  3000  kw.  hours.     In  addition 


each  ton  alcohol  requires  2500  ks.  of  ooal 
and  4000  kg.  limestone  (Chem.  Ind.  1917, 
335). 

Oxidation  of  Aldehydf.-^With  potassium 
permanganate,  acetic  acid  is  formed,  but  in 
presence  of  excess  of  potash,  oxalic  9od  carbonic 
acids  are  also  formM  (Denis,  Amer.  Chem.  J. 
38,  561). 

It  has  been  found  possible  to  oxidise  aoetalde- 
hyde on  a  commeroiat  scale  by  means  of  oxygen 
or  air  in  the  presence  of  a  -suitable  catalyst. 
The  various  patented  processes  may  be  divided 
into  two  classes : — 

(1)  Where  air  or  oxygen  is  passed  into  the 
liquid  aldehyde  containing  a  dissolved  catalyst. 

(2)  Where  the  two  substances  aro  passed 
over  a  heated  catalyst. 

(1)  The  Consortium  f.  Elektrochemische  In- 
dustrie (Eng.  Pat.  16849, 1913)  claim  the  produc 
tion  of  per-acetic  acid  by  treating  acetaldehyde 
with  oxygen  at  a  low  temperaturo,  proferablv 
with  the  exclusion  of  injurious  impu^ties,  such 
as  water  and  manganese  compounds.  The 
reaction  is  said  to  be  facilitated  by  the  use  of 
chemically  active  rays.  On  allowing  per-acetic 
acid  obtained  from  acetcddehyde  to  attain  the 
room  temperature  it  is  decomposed  by  the 
remaining  aldehyde  into  acetic  acid. 

(From  this  it  would  seem  possible  that  in 
the  various  processes  next  to  to  described,  the 
first  stage  in  the  production  of  acetic  acid  is 
the  addition  of  oi^gen  to  form  per-acetic  acid 
CH,CHO+0,=CH,CHOO„  which  then  reacts 
with  acetaldehyde,  yielding  acetic  acid : 

CH,CH00g-fCH,CH0=2CH,C00H.) 

The  same  patentees  next  described  (Eng.  Pat. 
17016,  1913)  the  production  of  acetic  acid  by 
oxidising  aldehyde  by  means  of  air  or  oxy^^ 
in  the  presence  of  a  manganese  compound  acting 
as  a  catalyst.  The  catalyst  is  preferably 
employed  in  the  dissolved  or  colloidal  condition 
which  may  be  prepared  by  introducing  per- 
manganates into  the  aldehyde  when  reduction 
takes  place  to  a  catalytically  active  brown 
liquid. 

In  Eng.  Pat.  17018,  1913,  the  Consortium 
describe  a  modification  of  Eng.  Pat.  16849, 1913, 
consisting  in  obtaining  per-acids  by  adding 
certain  metal  salts,  other  than  manganese  00m- 
pounds,  such  as  compounds  of  chromium, 
cobalt,  iron,  uranium,  and  vanadium,  li^he  use 
of  ferric  acetate  is  claimed  by  Th.  Dreyfus  in 
Eng.  Pat.  130035. 

A  further  modification  of  Eng.  Pat.  17016, 
1913,  is  claimed  by  the  Consortium  (Eng.  Pat. 
7418,  1914),  consisting  in  substituting  for  per- 
manganates the  formate,  acetate,  butyrate, 
benzoate,  lactate,  or  other  organic  salt  of 
manffanese. 

Meister  Lucius  and  Briining  (Eng.  Pat.  10377, 
1914)  assert  that  gr^tly  improved  results  are 
obtained  by  passing  in  the  air  or  oxygen  under 
pressure;  thus,  for  instance,  oxygen  at  a 
pressure  of  two  atmospheres  is  passed  into 
acetaldehvde  containing  1  p.c.  by  weisht  of 
eerie  oxide ;  the  temperature  rises  to  5(r-60^, 
and  cooling  is  necessary.  Yields  up  to  95  p.o. 
are  ciaim^;  as  catalysts  are  mentioned  also 
ferric  oxide,  vanadium  pentoxide,  chromium 
oxide,  and  platinum  black.  A  table  is  given, 
showing  the  influence  of  pressure : — 


ALDEHYDB. 


107 


Aorao  Acid  obtain  jbd  f.g,  of  THioEsncAi. 

YlBLD. 


Wtth  catalsnt. 
After  1  hoar,     4  p.a 
After  5  houzB,  16  p^a 


Wtth 
preasue. 

6p.a 
aOp.a 


Witli  pnssure 
and  Mtalyit. 
35p.o. 

96p.a 


A  aomewhat  diffsrent  prooess  is  given  in 
Eng.  Pat.  141 13»  1914,  by  the  Chemische  Fabrik 
Gnesheim  Elekferon,  conasting  in  manufacturing 
acetio  acid  by  panne  ace^lene  and  oxygen 
alternately  or  aimnltaneoaaly  into  aoetio, 
chloraoetKS,  laotio,  or  other  oiganic  acid  con- 
taining water,  to  which  has  be^  added  a  mer- 
cury compound  with  or  without  the  addition  of 
bisulphate,  sulphuric  acid,  &c.  Aldehyde  is 
tirst  formed  when  passing  in  acetylene,  and  is 
then  OTJdiBed  to  acetic  acid  by  the  oxygen 
subsequently  introduced.  This  proceedingsounds, 
however,  somewhat  dangerous,  and  is  probably 
less  easily  oontroUed  than  the  others.  The 
B.A.8.F.  claim  a  prooess  for  carrying  out  the 
oxidation  by  means  of  air  or  oxygen  in  presence 
of  iron  compounds  and  oiganio  salts  ci  alkalis 
and  alkaline  earths,  inclu<&ng  magnesiam  and 
aluminium  (D.  B.  P.  294724). 

(2)  The  second  method  Ib  described  by  the 
Ghem.  Fab.  Griesheim  Elektron  (Eng.  Pat.  17424, 
1911)>and  consists  in  adding  acetic  add,  ohlor- 
aoetio  acid,  or  acetic  anhydride  to  the  aldehyde 
before  the  commencement  of  the  oxidation.  A 
catalyst  such  as  vanadium  pentoxide,  uranium 
oxide,  or  roasted  ferrosoferric  onde,  Fe,04, 
facilitates  the  reaction.  The  prooess  may  be 
conducted  in  tubes  or  towers,  ftc,  packed  with 
ghiss  or  clay.  In  an  addition  to  this  patent 
(8076,  1912)  an  improvement  is  daimea  con- 
sisting in  treating  small  quantities  of  aldehyde 
with  oxygen  in  vessels,  tubes,  towers,  ftc,  until 
the  greater  part  is  oxidised  to  acetic  acid,  and 
then  adding  further  quantities  of  aldehyde  and 
pawring  a  6tronger  current  of  oxygen,  whereby 
oxidation  proc^ds  rapidly.  The  process  mav 
be  accelerated  by  the  addition  of  a  catalyst,  sucn 
as  those  already  mentioned. 

H.  Brevf  us  (Eng.  Pat.  106066)  claims  the  pro- 
duction of  acetic  acid  by  paiming  a  mixture  of 
aldehyde  vapour  with  air  or  oxygen  through 
vessels  or  tubes  containing  contact  substances, 
such  as  platinised  asbestos,  preferably  at  a 
temperature  above  the  boiling-point  of  acetio 
add ;  the  mixture  ol  aldehyde  vapour  and  air 
or  oxygen  may  be  preheated  to  a  suitable 
temperature  before  entering  the  contact  appa- 
ratus ;  the  heat  of  the  gases  iuuinff  from  the 
contact  apparatus  mav  be  utilised  for  this 
purpose,  tne  process  bemg  canned  out  in  appa- 
ratus similar  to  that  employed  in  the  manu- 
facture of  sulphuric  anhydride  by  the  contact 
process. 

The  same  inventor  in  a  later  patent  (Eng. 
Pat.  108469)  describes  a  further  modification  of 
the  previous  process  consisting  in  oxidising  acet- 
aldehyde  by  means  of  air  or  oxygen  at  temper- 
aturee  of  16O'-260''  0.  either  in  presence  or 
absence  of  a  catal^.  Suitable  cataJysts  are 
stated  to  be :  pUtmnm,  copper,  copper  oxide, 
chromium  oxiae,  uranium  oxide,  vanadium 
oxide,  cerium  o^dde,  iron,  pumice,  &o.  The 
ffases  are  preferably  caused  to  travd  through  a 
long  path  in  the  reaction  apparatus,  and  the  air 
employed  is  preferably  in  excess  of  the  theoretical 


amount.  Further  improvements  given  in  En^. 
Pat.  110646,  by  the  same  patents,  are  chiefly 
concerned  with  minor  detailB ;  thus  the  mixture 
of  aldehyde  vapour  and  air  may  be  obtained  by 
pawring  air  through  liquid  aldehyde  and  passing 
the  mixture  into  the  reaction  chamber;  or 
liquid  aldehyde  may  be  vapcoiaed  by  a  current 
of  air  in  the  bottom  of  the  reaction  chamber 
itself,  the  latter  being  provided  with  suitable 
agitators.  The  temperature  of  the  liquid 
ahlehyde  or  of  the  air  mav  be  rejgulated  so  as  to 
control  the  oompodtion  of  the  mixture  of  vapour 
and  gas,  or  the  liquid  aldehyde  may  be  suitably 
diluted,  say,  witn  acetic  add  for  the  same 
purpose.  The  liquid  aoetio  add  formed  coUeets 
m  a  suitable  part  of  the  apparatus  and  flows 
away,  while  the  issuing  gas  containing  aldehyde 
may  be  treated  again,  or  the  contained  aldehyde 
may  be  recovered  and  re-used  (</.  Fr.  Pat. 
479666,  and  additions  20201,  20202). 

In  Eng.  Pat.  116279,  S.  Utheim  daims  the 
production  of  acetio  acid  from  aldehyde  by  the 
action  of  oxygen  under  pressure,  the  aldehyde 
being  supplied  to  the  oxy^n  in  a  confined  Hpace 
in  limited  quantities,  e,g,  m  a  number  of  narrow 
tubes  with  suitable  cooling.  Whilst  the  Comp. 
des  Prod.  chim.  d'Alais  describe  the  oxidation 
as  taking  plaoe  in  suitable  towers  by  means  of 
air  or  oxy^^  in  absence  of  a  catalyst,  the 
product  being  heated  continuoudy  to  destroy 
any  peracetic  acid  formed  (Eng.  Pat.  130661). 

The  process  described  in  Ex^.  Pat.  109983  by 
the  Chenusche  Fabrik  Rhenania  falls  into  a 
somewhat  different  category,  as  it  deals  with  the 
direct  production  of  acetic  add  from  acetylene 
by  passing  the  latter,  mixed  with  steam,  over 

Sartially  reduced  bog  iron-ore;    the  prooess 
oes  not,  however,  appear  to  be  of  much  import- 
ance owing  to  the  poor  yield. 

Hibbert  (U.S.  Pat.  1230899 ;  Can.Pat.  178237) 
recommends  the  use  of  wood  charcoal  previously 
saturated  with  strong  acetio  acid  to  promote 
the  reaction  between  acetaldehyde  and  oxysen, 
using  it  as  a  packing  for  towers  throush  which 
the  mixture  is  passed.  A  90  p.c.  yidd  of  70 
p.o.  add  is  obtamed,  working  at  46^  0. 

W.  H.  Matheson,  of  the  Canadian  Electro- 
products  Co.,  Shawinigan  Fall,  Quebec,  states 
that  the  oxidation  process  carried  out  at  these 
works  is  done  in  aluminium  vessels,  as  copper, 
iron,  etc ,  are  unsuitable  and  have  led  to  violent 
explosions  (CJan.  Chem.  Jour.  III.  260  (1919). 
These  works  manufactured  synthetic  acetone  and 
acetio  acid  for  the  British  Government  during 
the  war,  and  from  Nov.,  1917»  to  Nov.,  1919, 
aboat  10,000  tons  alacial  aoetio  acid  were 
shipped  to  England,  chiefly  for  the  manufacture 
of  acctylcdlukse  for  aeroplane  dope;  at  the 
time  of  the  Armistice  (Nov.  11,  1919),  the  ])lant 
had  been  enlarged  to  produce  about  1600  tons 
per  month  at  a  total  capital  cost  of  about 
£800,000.  According  to  A.  F.  (^adenhead  (Can. 
Chem.  Jour.  III.,268(1919)),one  ton  of  carbide 
produces  on  an  average  about  half  a  ton  of 
acetio  acid. 

When  subjected  to  electrolysis  in  faintly 
alkaline  or  neutral  solution  it  is  decomposed  into 
alcohol  and  acetic  adds  (Slaboszewioz,  Chem. 
Zentr.  1903,  i  279;  Law,  Chem.  Soo.  Trans. 
1906,  198;  Jackson  and  Laurie,  ibid,  1906, 
166),  whilst  when  heated  alone  to  high  tempera- 
tures carbon  monoxide  and  methane  are  the 


108 


ALDEHYDE. 


chief  prodacts  (Bone  and  Smith,  Chem.  Soo. 
Trans.  1906,  910 ;  IpaUefi,  Chem.  Zentr.  1906, 
u.  87 ;  Nef,  Ann.  318,  198).  Action  of  silent 
electric  discharge  (c/.  Besson  and  Foumier, 
Compt.  rend.  150,  1^8).  Action  of  oltra-violet 
rays  (Berthelot  and  Gandechon,  Compt.  rend. 
m,  233). 

Aoetaldehyde  and  its  dimethyl  derivatiye 
haye  antiseptio  properties  (Coblenz,  J.  Soo. 
Chem.  Ind.  17,  728;  Pasqualis,  Chem.  Zentr 
1897,  ii.  10,  12).  It  Is  also  osefol  in  photo- 
graphic devebpinff  (Seyewets,  Bull.  Soo.  chim. 
19,  (3)  134),  and  the  yaponr  or  solution  in 
alcohol  or  benzene  slowly  nardons  dry  gelatine 
films  (Beokmann,  Chem.  Zentr.  1896,  iL  930 ; 
D.  R.  P.  116446;   116800). 

Production  of  synthetic  rubber  indirectly 
from  aldehyde,  9ee  Duboso  (Caoutchouc  et 
Qutta  Percha,  9,  6608,  6713).  In  presence  of 
alumina  at  400**  isopropyl  alcohol  condenses 
with  aldehyde  to  giye  a  good  yield  ofpiperylene 
(Ostromlsslensky,  J.  Buss.  Phys.  Chem.  Soc. 
47,  1607).  By  passing  aldehyde  and  alcohol 
yapours  oyer  heated  catalysts,  such  as  alumina, 
phosphoric  acid,  &c.,  butadiene  Is  formed 
( Ostromimlenwty,  J.  Buss.  Phys.  Chem  Soc. 
47,  1494,  1609).  Precipitated  alumina  is 
specially  noted  as,  heated  to  369''-460®,  a 
16-18  p.c.  yield  of  pure  erythrene  is  obtained. 

Aidehyde  readily  polymerises  in  the  presence 
of  small  quantities  oi  yarious  substances,  such 
as  sulphuric  add,  phosgene,  zinc  chloride, 
hydrogen  chloride,  sulphur  dioidde,  the  halogens, 
particularly  iodine,  sc,  and  two  compounds 
are  obtained  the  relatiye  quantities  of  which 
depend  upon  the  temperature;  the  chief  pro- 
duct being  meUUdehyde  (C|H40)g  (Hanriot  and 
Oeoonomides,  Ann.  Chem.  Pnys.  [5]  26,  227 ; 
Mcintosh,  Chem.  Soc.  Trans.  1906,  790; 
ZecchinI,  Gaaz.  chim.  ital.  22,  ii.  686),  when 
the  action  takes  place  in  a  freezing  mixture; 
and  the  Isomeric  paraldehyde  (elaldehyde)  when 
it  occurs  at  the  ordinary  temperature. 

Paraldehyde  (CtH40),  is  prepared  from 
aceteldehyde  by  the  sddition  of^a  drop  of  con- 
centrated sulphuric  acid,  the  liquid  boiUng  up 
at  once  with  almost  explosiye  yiolence;  the 
product  can  be  purified  either  by  freezing  out 
oelow  0°  and  remoying  the  liquid  portion,  or 
by  washing  with  a  little  dilute  sodium  carbonate 
solution,  drying    oyer    calcium    chloride    and 


rectifying  (Fehlmg,  Annalfsn,  27,  319 ;  Werden- 
bttsch,  fSid.  66,  166 ;  Geuther  and  Cartmell, 
ibid.  112,  17;  Geuther,  Zeitsch.  f.  Chemie, 
1866,  32;  Lieben,  Annalen,  Suppl.  1,  114 
1861-2  ;  Kekul^  ft  ZIncke,  Annalen,  162,  143  ; 
Briihl,  ibid.  203,  26,  43;  Franchimont,  Rec. 
tray.  chim.  1,  239;  Desgrez,  Bull.  Soc.  chim. 
11,  [3],  362;  Wachhausen,  Chem.  Zentr.  1897, 
1,  493 ;  Ciamidan  and  Silber,  Ber.  36,  1080). 
Polymerisation  is  also  caused  by  halogen 
hydracids  (Macintosh,  J.  Amer.  Chem.  Soc. 
28,  688).  In  the  latter  case  addition  producte 
are  formed,  e,g.  (C,H40),-3Ha,  m.p.  —  1S°; 
(C,H.0),-3HBr,  m.p.  -15*»;  (O.H^O.^Hl, 
liquid  below  —32^.  Paraldehyde  is  a  clear 
mobile  colourless  liquid  of  pleasant  odour  and 
sharp  taste,  b.p.  124%  D,o  0*994,  m.p.  12*6''. 
It  possesses  the  same  molecular  weight  also  in 
'■^  yapour  phase,  and  in  solution  (Patem  and 
ini,  Ber.  19,  2629 ;  Carrara  and  Terrari, 
chim.  ital.  36,  i.  420).  It  is  sparinsly 
e  in  water,  100  yols.  water  at  13**  dusolymg 


12  parte  paraldehyde,  the  solubility  diminishing 
on  warmmg ;  it  does  not  show  the  characteristic 
aldehyde  reactions ;  thus  it  does  not  reduce 
ammonlacal  silyer  nitrate,  does  not  resinify  on 
heating  with  aqueous  ^tash,  and  does  not 
unite  with  ammonia  or  bisulphites ;  ite  formula 
is  therefore  assumed  to  be : 

O— CH^H, 

CH,CH<        yo 

^0— CH^CH, 

On  warming  with  a  little  sulphuric  add  it  is 
readily  depolymerised  completely  into  ordinary 
aldehyde;  many  other  reagento  also  produce 
<^e  same  effect ;  it  may  also  occur  on  yery  long 
standing  (Troeger,  Ber.  26,  3317).  Owing  to 
the  ease  of  dSpolymerisation  paraldehyde  ii 
frequently  made  use  of  in  place  of  aldehyde  for 
many  reactions  where  the  monomolecular  form 
is  inconyenient  to  use  owing  to  ite  low  boiling- 
point. 

Thus  it  condenses  with  diacetoneamine  to 
form  yinyldiacetoneamlne  (E.  Fischer,  Ber.  17» 
1793;  C.  Harries,  Ber.  29,  622);  with  aniline 
to  form  quinaldine  (D.  B.  P.  24317 ;  28217 ; 
36133 ;  Kng.  Pat.  966,  1883 ;  4207,  1883),  and 
with  hydrozyquinol  to  form  yellow  dyes  (Ueber- 
mann  and  Lendenbaum,  Ber.  37,  1171,  2728). 

Paraldehyde  sete  free  iodine  from  alkali 
iodides  (Wachhausen,  Chem.  Zentr.  1897,  i. 
493).  It  is  not  attacked  by  pure  nitric  acid, 
but  Is  readily  oxidised  if  nitrous  acid  be  present 
(Behrens  and  Schmitz,  Annalen,  277,  313,  336). 

Smite  and  de  Leeuw  assume  the  existence  of 
an  equilibrium  of  a  pseudo-ternary  system  of 
aldehyde-metaldehyde-paraldehyde,  the  yalues 
for  the  different  componento  yarying  accordii^ 
to  the  catalyst  (Smite  and  de  Leeuw,  K.  Akad. 
Wetenschapen,  1910,  318 ;  Amer.  Chem.  Abetr. 
1911.  1862 ;  Zeitsch.  physiol.  Chem.  77,  268). 
Puraldehyde  is  used  to  some  extent  as  a  sopo- 
rific. 

Mdaldehyde  crystallises  in  needles  or  tetra- 
gonal prisms,  sublimes  without  preyious  fusion 
at  112^-116'',  and  when  heated  m  sealed  tubes 
at  120^  is  entirely  reconyerted  into  ordinary 
aldehyde  (Friedel,  Bull.  Soc.  chim.  9,  (3)  384). 
According  to  Troeger  (Ber.  26,  3316),  after 
standing  for  ten  years  a  sample  was  converted 
into  alaehyde  and  paraldehyde,  but  according 
to  Hantzsch  and  Oechslin  (Ber.  40,  4341), 
metacetaldehyde  is  not  isomeric  with  paracet- 
aldehyde,  and  is  quite  steble  when  pure. 
Omdorff  and  White  (Amer.  Chem.  J.  16,  43) 
stote  that  when  it  is  allowed  to  stand  for 
some  time  the  metaldehyde  is  converted  into 
tetraldehyde  (CaU^O^. 

Neither  polvmeride  is  resinised  by  aqueous 
soda  or  potash,  but  in  other  reactions  they 
behave  generally  as  ordinaiy  aldehyde  and  yield 
similar  producte  (Kekul^  and  Zinoke). 

Formation  of  Acetic  Ester, — ^Another  im- 
portent  change  of  the  nature  of  polymerisation 
tekes  place  under  certain  conditions,  causing 
the  formation  of  acetic  ester  in  excellent  yield. 

Tischtschenko  (J.  Ross.  Phys.  Chem*.  Soc. 
38,  398-418  :  Chem.  Zentr.  1906,  u.  1309,  1662) 
proposes  the  following  method  of  workmg: 
Acetaldehyde  is  coolra  down  to  —20''  C, 
uncrushed  aluminium  ethylate  is  added,  and 
the  mixture  allowed  to  stand  for  several  days 
or  weeks.    On  the  basis  of  his  experimente  oa 


ALDEH7DE. 


109 


decided  that  the  yield  of  acetic  ester  increaaes 
with  the  amount  of  alcoholate  added  but  only 
to  a  certain  mftTimnm  limit,  namely  69 '1  p.c. 
of  eater  (aamg  15  p.a  of  altuninium  ethvlate), 
and  that  it  la  neceesary  to  uae  the  alcoholate  in 
Inmpa;  lie  also  ooncdaded  that  b^  using  amall 
qnantitieB  of  the  oatalyst  the  yield  m  eater 
is  leaaetnad,  with  inoreased  formation  of  by- 
prodocta,  and  when  only  abont  4  p.a  alcoholate 
is  used  the  formation  of  by-^rodncts  piedomi- 
natea  over  the  eater  condensation. 

The  Gonsortinm  f.  Elektrochemisohe  Indus- 
trie found  later  (Eng.  Pat.  26825, 1913)  that  the 
▼arioos  drawbacks  could  be  overoome  by  adding 
to  the  aluminium  alcoholate  certain  oatidytio 
subatancesy  auch  as  tin  ohlor-ethylate,  which 
are  without  catalytic  activity  themselvea  but 
increase  the  power  of  the  alcoholate  very 
greatly ;  thus,  in  an  example,  150  pjpts  anhy- 
drous aldehyde  were  cooled  down  to  0°  C,  and  9 
partsof  aluminium ethy late  previously  fused  with 
10  p.c.  of  tin  chloretnylate,  (from  20  parts  tin 
tetrachloride  and  14  parts  absolute  alcohol)  were 
added  during  half  an  hour,  with  vigorous  stirring 
and  efficient  coolins.  After  ten  hours  the  odour 
of  aldehyde  had  msappeaied  and  the  product 
waa  diatnlBd,  96  p.o.  of^ahnost  pure  acetic  eater 
ooming  over  between  74^  G.  and  80**  0.  A 
comparative  experiment  in  which  the  stannic 
chloRthylate  waa  omitted  gave  only  a  19  p.c. 
yield.  In  Eng.  Pat.  26826,  1913,  by  the  same 
firm,  a  further  improvement  is  claimed,  using 
instead  of  anhydrous  aluminium  ethylate,  the 
same  body  treated  with  a  amall  quantity  of 
water  or  with  subetanoea  containing  water,  in 
particular  aluminium  hydroxide.  In  an  example 
the  following  fignrea  are  given : — 

Yield  of 
Kind  of  alcoholate.  Al.  content,  ester. 
Untreated  ....  17*7  p.c.  21  p.a 
Fused  with  a  little  water  21*0  p.o.  87  p.c 
Untreated  .  .  .  .  17*7  p.o.  23  p.o. 
Fueed  with  A](OH),      .    24*8  p.a    85p.o. 

Tlie  fnrtiier  improvementa  daimed  in  Eng. 
Pat.  4887,  1915  {idem.)  consist  in  increasing  the 
activity  of  the  cataljrst  by  dissolving  in  the 
melted  alcoholate  suitable  subetances  such  as 
dehydrated  potash  alum,  dehydrated  copper 
SQlphate  or  camphor,  or  by  supercooling  the 
alcoholate^  e^.  by  melting  and  cooling  rapidly 
by  pouring  into  a  solvent  or  on  to  a  metal 
plate.  Ethyl  acetate  is  of  special  use  aa  a 
aolvent ;  the  mixture  of  melted  alcoholate  and 
added  anbstancea  mentioned  above  mav  also 
be  dissolved  in  ethyl  acetate ;  the  aolutions 
may  be  employed  hot,  or  may  be  allowed  to  cool 
wttiL  partiiu  separation  of  uie  alcoholate  from 
eolation. 

Meiater,  Ludna  and  Brnning  describe  (Eng. 
Pa^:  1288,  1915)  the  production  of  acetic  ester 
from  aldehyde  by  means  of  aluminium  alcoholate, 
the  latter  being  diasolved  in  a  suitable  organic 
aolvent  such  aa  dry  aolvent  naphtha. 

{Alwmininm  AkohokUe, — ^The  production  of 
tfaia  catalyst  is  described  by  Farbw.  v.  Meister, 
Luctofl,  and  Brnning  in  D.  B.  P.  286596,  and 
addition  293613,  and  in  289167.  According  to 
thoae  nedfieations  aluminium  ethoxide  is 
obtained  in  good  irield  from  aluminium  and 
aahydrooa  alcohol  S,  in  presence  or  absence  of 
lialogen  alkyls  or  iodine,  small  amounts  of 
flUffearie  chlimde  are  added  as  a  catalyst ;  other 


alcohols  may  be  substituted  for  ethyl  alcohol, 
yielding  the  corresponding  alcoholates. 

Upon  subsequent  vacuum  distillation  for  the 
purpose  of  purifying  the  crude  product,  the 
aluminium  ethylate  goes  over  readily  without 
bumping,  solidifying  to  a  snow-wmte  mass, 
while  mercury  is  not  carried  over  with  it.  Or 
the  ethylate  may  be  distilled  under  atmospheric 
pressure  without  decomposition  if  the  vapours 
are  rapidly  withdrawn  from  further  super- 
heating. This  may  be  effected  by  employing 
a  low  form  of  distilling  vessel  whereby  con- 
densation in  the  upper  part  of  the  vessel  is 
prevented.) 

Beaclicns* — ^Aldehyde  in  aqueous  solution 
very  readily  reduces  an  ammoniacal  solution  of 
silver  nitrate  giving  a  bright  metallic  mirror. 
Aoetaldehyde  (and  all  aldehydes  which  are 
stable  in  aqueous  soda  solution)  can  be  de- 
tected by  addiiu;  to  a  solution  of  the  suspected 
substance  in  duute  alkali  a  freeh  solution  of 
1  part  of  paradiazobenzenesulphonic  acid  in 
60  parts  of  water  rendered  alkalme  with  a  little 
soda,  and  then  some  sodium  amalgam;  if  an 
aldehyde  is  present,  a  reddish-brown  colour  is 
developed  after  the  mixture  has  stood  for  10-20 
minutes  (Penzoldt  and  Fucher,  Ber.  16,  657). 

A  solution  of  rosaniline  decolourised  by  sul- 

fhurous  acid  (Villiers  and  FovoUe,  Compt.  rend. 
19, 75),  or  maffcnta  bleached  Iby  sunlight  (Blaser, 
Ghem.  Zentr.  1899,  ii.  848),  reeains  its  ori^pnal 
colour  on  addition  of  an  aldehyde  (Denig^s, 
Compt.  rend.  150,  529).  This  reaction  is  due  to 
the  formation  of  coloured  compounds  by  the 
condensation  of  the  aldehyde  and  magenta 
(Urbain,  Bull.  Soc.  chim.  1896,  iii.  15,  455). 
With  salts  of  m-diamines  aldehydes  give  coloured 
solutions  with  intense  greenish  fluorescence 
(Bitto,  Frdl.  36,  369).  With  sodium  nitro- 
prusside  and  alkali,  aoetaldehyde  gives  a 
cherry-red  colouration,  whilst  if  tn-methylamine 
is  first  added  a  blue  colour  is  produced  (Bittoi 
AmuJen,  267,  372 ;  269,  377 ;  Benigte,  Bull. 
Soc.  chim.  17,  (3)  381  ;  Simon,  Compt.  rend. 
125,  1106 ;  BuU.  Soc.  chim.  19,  (3)  297).  Thio- 
semioarbazide  mixed  with  an  aldehyde  in  acetic, 
alcoholic,  or  aqueous  solution  yields  character- 
istic thiosemicarbazones.  Acetaldehydethio- 
semicarbazone  has  m.p.  146^  (FreundandSohan- 
der,  Ber.  35,  2602).  Phenylhydrazone  a-form, 
m.p.  98*^-101° ;  jS-form,  m.p.  57®  (Lockemann 
and  liesche,  Annalen.  342,  14;  Laws  and 
Sidgwiok,  Trans.  Chem.  Soc.  99,  2085). 
Toschi  and  Angiolani  (Gaza.  chim.  ital.  45, 
L  205)  recommend  the  use  of  4-4'-dipheny)- 
semicarbazide,  the  acetaldehyde  derivative 
having  m.p.  133''-134^ 

Ouier  tests  for  aldehydes  are  described  by 
Ihl,  Chem.  Zeit.  14,  1571 ;  Doebner,  Ber.  27, 
362,  2020 ;  Lumi^re  and  Seyewetz,  Bull.  Soc. 
chim.  19,  (3)  134;  Rimini,  Atti  Real.  Acad. 
Lincei,  1901,  10,  356 ;  Muroo,  Compt.  rend.  31, 
943;  Riegler  Frdl.  42,  168;  Behrens,  Chem. 
Zeit.  26,  1125;  Sadtier,  J.  Soc.  Chem.  Ind. 
23,  387 ;  Prud*homme,  Bl.  Soc.  Ind.  Mulhouse, 
1904,  74,  169 ;  Leys,  J.  Pharm.  Chim.  1905,  22, 
107  ;  Auld  and  Hantzsch,  Ber.  38,  2677. 

Quantitative  Etitimation.—Cf.  Rieter,  Chem. 
Zentr.  1896,  ii.  368;  Rocques,  Compt.  rend. 
127,  526,  764;  Seyewetz  and  Bardin,  Bull. 
Soa  chim.  [3]  33,  1000 ;  CoUes,  Trans.  Chem. 
Soc.  89,  1249.     Colorimetrio  estimation,  Paul, 


110 


ALDKUyOE. 


Zeitaolu  f.  anaL  Chem.  35,  049;  Tolmao.  J. 
Amer.  Chem.  Soo.  28,  1624;  by  meaiiB  of 
pyrrole,  SoboleT  and  Salesld,  Zeitooh.  phymol. 
Gnem.  69,  441.  Estimatioii  in  presence  of 
paraldehyde,  Riohter,  Pharm.  Zeit.  57,  125; 
Heyl,  ihiJ.  28, 166, 720.  In  preeenoe  of  acetone, 
Bagglnnd,  Zeitsch.  anal.  Chem.  53,  433. 

Condentaiioii  Products. — ^Aldehyde  readily 
yiekb  oondensation  oomponnds;  thos  when 
allowed  to  remain  in  the  oold  with  dilute  hydro- 
ohlorio  add,  or  witii  aqneons  lolatioDB  of  dnc 
chloride  or  of  salts  having  an  alkaline  reaction, 
•Qoh  as  potassinm  carbonate,  aldol  is  obtained. 

The  Dapont  de  Nemonrs  Powder  Co.  desoiibe 
(Eng.  Pat.  17259,  1911)  the  production  of  ace- 
taldol  by  means  of  a  solution  of  aikaU  or  alkaline 
carbonate,  borate,  j^osphate,  or  cyanide ;  the 
aoetaldol  so  produced  may  be  extracted  with 
ether;  or  the  solution  may  be  reduced  bv 
aluminium  amalgam  to  yield  butylene  glycol. 
A  further  patent  by  the  same  firm  (Eng.  Pat. 
22621,  1912)  claims  the  production  of  aldol  by 
treating  aldehyde  with  an  alkaline  substance, 
such  as  an  alkali  hydroxide  or  salt,  sodium 
eihylate  &c.,  diasolyed  in  a  solvent  containing 
little  or  no  water.  Ethyl  alcohol  is  mentioned 
as  a  suitable  solvent  (e/.  also  Swiss  Pat.  64932 ; 
a.8.  Pat.  1151113). 

The  Consortium  f .  Eletrbchemisohe  Indus- 
faie  in  Eng.  Pat.  19463, 1913,  daim  the  produc- 
tion of  aldol  by  treating  aldehydo  in  the  absence 
of  water  with  a  small  quantity  of  an  alkali  or 
alkalme  earth  metal,  or  aUoy  or  amalgam  thereof, 
or  with  their  compounds  with  aldehyde  or  with 
other  compounds  of  these  metals  that  are  soluble 
in  aldehyoB,  such  as  the  alcoholatrsor  cyanides. 
By  slow  distillation  in  vacuo  aldol  is  obtained, 
and  hj  slow  distillation  at  ordinary  pressure 
orotomo  aldehyde  is  formed.  Oigano-metaUio 
compounds  are  formed  by  adding  alkali  and  alka- 
line-earth metals  to  aldehyde  in  the  absence  of 
water  (e/.  also  D.  R.  P.  269996). 

AooMding  to  N.  Grunstein  (Eng.  Pbt.  101636) 
aldol  and  other  condensation  prmlucts  are  ob- 
tained from  acetaldehyde  by  treating  the  latter 
with  quicklime  or  strontia;  the  reaction  is 
facilitated  by  the  addition  of  a  trace  of  water. 
The  condensatfon  can  also  be  effected  by  means  of 
other  condensing  agents,  such  as  alkaline  earth 
metals  or  their  carbides,  such  as  calcium 
carbide,  mixed  or  not  with  the  oxides;  the 
aldehyde  is  preferably  introduced  during  the 
process.  The  aldol  jnoduced  can  be  distilled 
tfi  wctio.  Hibbert  describes  the  production 
of  aldol  by  dissolving  aldehyde  in  gasoline  and 
treating  the  solution,  after  coolii^  to  —10^, 
with  potash  or  caustic  soda  (U.S.  Pat.  1066048). 

Crotonaldehyde  is  formed  when  it  is  heated 
with  concentrated  hydrochloric  acid  (Kekul6, 
Annakn,  162,  92 ;  Klmg  and  Roy,  Compt.  rend. 
144,  1111 :  Zeisel  and  v.  Bitto,  Monatsh.  29, 
591),  or  with  concentrated  sulphuric  acid  (Del6- 
pine,  Compt.  rend.  133,  876;  147,  1316;  Bull. 
§00.  ohim.  27  [31  7). 

Aldehyde  has  also  been  condensed  with  other 
aldehydes  and  ketones  (Wallach,  Chem.  Zentr. 
899,  iL  1024;  Schmalzhoffer,  Monatsh.  211, 
671;  Wogrinz,  tbid.  22,  1;  Weiss,  ibid.  25, 
1066 ;  Schachner,  ibid.  26,  66  ;  Salkind,  J.  Rum. 
Phys.  Chem.  Soc.  37,  484;  Rainer,  Monatsh. 
25,  1035 ;  Ehrenfieund,  ibid.  26,  1003) ;  with 
amines  (Eibner  and   Peltxer,   Ber.   33,   3460; 


Eibner,  Annalen.  328,  121 ;  Knoevenagd,  Bet. 
37,  4461) ;  with  rhodanio  and  sabatituted  rho- 
danic  adds  forming  stable  dveing  oompounds 
(Andreasch  and  Zinser,  Monatsh.  24,  499;  26, 
1191;  Zipser,  tbid.  23,  592;  Staoheta,  ibid. 
26,  1209 ;  Beigellini,  Atti  Real.  Acad.  linoei, 
15,  35,  181 ;    Andreasch,  Monatsh.  27,  1211 ; 

29,  399 ;  Wagner,  ibid.  27,  1233) ;  with  methyl 
ketole  forming  leuoo-  bases  A  the  dyes  of 
rosaniline    type    (Fieund    and    liebaoh,    Ber. 

36,  308 ;  Freund,  Ber.  87,  322) ;  with  Indole 
dyes,  also  forming  leuco-  bases  (Loew,  Ber.  36, 
4326) ;  with  cyanides  and  oyanacetio  esters 
(Claisen,  Ber.  25, 3164 ;  Barbier  and  Bonveault, 
Compt.  rend.  120,  1269;  Kohn,  Monatsh.  19, 
519 ;  Wade,  Chem.  Soo.  Pioc.  1900, 156 ;  Bertini, 
Gaaz.  ohim.  ital.  31,  L  265 ;  Fiquet,  Bull.  Soo. 
chim.  7,  (3)  767);  with  phenyl  hydracooes 
(Fischer,  Ber.  29, 793 ;  30, 1240 ;  Peohman,  Ber. 
31,  2123 ;  Bamberg  and  Pemsel,  Ber.  36^  85 ; 
Lookmann  and  Liesohe,  Awna^lAn^  342,  14; 
Medvedeff,  Ber.  38, 16646, 2288 ;  Maorenbrecher, 
Ber.  39, 3583;  Laws  and  Sidffwiok,  Trana  Chem. 
Soo.  99,  2085);  with  o-hyoroxy  nitroao  com- 
pounds pyrazine  derivatives  are  formed  (Lange, 
Ber.  42,  574).  Substanoes  capable  of  use  in 
perfumery  can  be  obtained  by  condensing  alde- 
nydes  with  negatively  mono-  substituted  aoetio 
acids  in  presence  of  ammonia  or  a  primary  or 
seoondaiy  amine  (J.  Soo.  Chem.  Ind.  24,  689, 
1323).  (For  oompounds  of  other  substanoes 
with  aldehydes,  ms  Hooker  and  Cameil,  Chem. 
Soo.  Proo.  1893,  Fischer,  Ber.  27,  165 ;  Claiaen, 
Annalen,  237,  261 ;  Conneler,  Chem.  Zett.  20, 
585 ;  Kietreiber,  Monatsh.  19,  735 ;  Bamberger 
and  Miiller,  Ber.  27,  147;  Rassow,  J.  pr. 
Chem.  172,  136,  129 ;   Betti,  Gazz.  chim.  ital. 

30,  ii  310 ;  33,  i.  27 ;  Koenigs,  Ber.  34,  4336  ; 
Moureu  and  Desmots,  C!ompt.  rend.  134,  855 ; 
Enoevenagel,  Ber.  36,  2136 ;  Hann  and  Lap- 
worth,  Chem.  Soa  Tnms.  1904,  46 ;  Simon  and 
Conduch6,  Ck>mpt.  rend.  138,  977;  Barzens, 
Ck>mpt.  rend.  142,  214;  Eissler  and  Pollock, 
Monatsh.  27,   1129;    Rolla,  Gazz.  ohim.  ital. 

37,  623 ;  Senior  and  Austin,  Chem.  Soo.  Trans. 
1907,  1233  ;  Wohl,  Ber.  40,  4679 ;  Braun,  Ber. 
41,  2169 ;  Zeisel  and  Bitto,  Monatsh.  29,  591.) 

AddiHvt  compownda. — ^Aldehyde  not  oidy 
shows  a  stronjg  tendency  to  yield  polymerides 
and  condensation  compounds,  but  umtas  directly 
with  a  Urge  number  of  substances. 

(1)  Compounds  with  alcohols  (v.  Acetau). 

(2)  Compounds  with  acids: — Geuther, 
Annalen,  106,  249 ;  lieben,  ibid.  106,  336 ;  178, 
43 ;  Rubencamp,  ibid.  225,  279 ;  Sohiff,  Ber.  9, 
304 ;  Ponzio,  J.  pr.  C!hem.  161,  431 ;  Schroeter, 
Ber.  31,  2189 ;  Annalen,  303,  114 ;  Del^pine, 
Compt.  rend.  133,  876 ;  Mcintosh,  Amer.  Cncm. 
J.  &,  588;  Wegscheider  and  Spath,  Chem. 
Zentr.  1910,  i.  1421  (v.  Acbtals). 

(3)  Compounds  with  alkaline  sulphites: — 
Aldehyde  forms  definite  crystalline  compounda 
when  dissolved  in  concentrated  aqueous  solu- 
tions of  the  acid  sulphites  (bisulphites)  of  the 
alkali  metals.  The  poloMtiim  salt  (;^.0,KH80a 
crystallises  in  indistinct  needles;  the  wiium 
salt  C,H«0,NaHSO,+iH.O,  in  fine  needles  or 
nacreous  plates.  The  ammomum  compound 
has  the  formula  C|H«(0H)80.-NHt.  These  salts 
are  almost  insoluble  in  excess  of  the  sulphite, 
and  separate  in  the  crystalline  state ;  from  them 
aldehyde  can  be  obtained  by  distillation  with  a 


ALDOL. 


Ill 


Bt^nger  acid,  an  alkaline  carbonate,  or  by  allf  ali 
nitriteB  (Bonte,  Annalen,  170,  305 ;  Freundler 
and  Bnnel,  Compt.  rend.  132,  1338;  Seye- 
wetz  and  Bordin,  Compt.  rend.  141, 259 ;  Rosen- 
heim, Ber.  38,  2006;  Ck>ppook,  Chem.  News, 
1907,  226).  ^th  hyposulphiteB  in  neutral  or 
add  solutions  aldehyde  hyposalphites  are 
obtained ;  2RGHO,Ma8,04  (J.  Soa  Chem.  Ind. 
25, 475) ;  by  varyii^  the  condition  snlphozylates 
of  type  BGH,-80,M  can  be  formed  (D.  R.  P. 
180529).  Crystalline  thioaldehydes  are  obtained 
by  the  action  of  hydrogen  sulphide  on  an  acidified 
alcoholic  solotion  of  aldehyde  (Baumann  and 
Fromm,  Ber.  22,  2600 ;  Ber.  24,  1419,  1467 ; 
Klinger,  Ber.  32,  2194 ;  Drugman  and  Stockings, 
Chem.  Soc.  Proc.  1904,  116;  Vanino,  J.  pr. 
Chem.  186,  367). 

(4)  Compound  with  ammonia: — Aldehtfde- 
ammonia  CaH40'NH„  obtained  by  leading  dry 
ammonia  into  aldehyde  in  ethereal  somtion 
(Liebig,  Annalen,  14,  144;  Jean,  Bull.  Soc. 
chim.  13,  (3)  474 ;  TiiUat,  ibid,  13,  (3)  689 ; 
I>el6pme,  Compt.  rend.  126,  951;    128,  106; 

•  137,  984;  14^  853;  Coninck,  Compt.  rend. 
126,  1042;  Tschitschibabin,  J.  Russ.  Phys. 
Chem.  Soc  37,  1229 ;  Duden,  Bock  and  Reid, 
Ber.  38,  2036 ;  Ciamician  and  Silber,  Ber.  38, 
1671  ;  39,  3942),  crystallises  in  huge  rhombo- 
hedra,  melta  at  70^-80'',  boils  at  lOO""  without 
deoomposition,  and  is  decomposed  into  its 
constituents  on  distillation  witn  dilute  acids. 
When  hydrogen  sulphide  is  passed  through  a 
mixture  of  aldehyde  ammonia  and  ether  a 
crystalline  substance  SHCHMeNHCHMeOH, 
m.p.  60°-63^  is  obtained  (Chabri6,  C.  R.  Soc. 
Biol.  1896,  3,  72). 

(5)  Compounds  with  hydrocyanic  acid: — 
(Tiemann,  Ber.  14,  1965 ;  Strecker,  Annalen, 
01,  349 ;  Erlenmeyer  and  Passavant,  ibid,  200, 
120). 

(6)  Compounds  with  metallic  salts  :~With 
mefouric  sulphate  it  forms  the  compound 
SO4  :  (HgO)a  :  HgCsH^O  (Denig^,  Compt.  rend. 
128,  429) ;  with  mercuric  nitrate,  C.HgsNOtH 
(Hofmann,  Ber.  31,  2212) ;  and  with  mercuric 
acetate  alkaline  solution  at  0°,  CMe*HO'HgO 
(Laaserre,  J.  Pharm.  1905,  22,  246).  With  gold 
chloride  it  forms  a  coloured  colloidal  solution 

iGarbowski,  Ber.  36, 1216) ;  and  with  magnesium 
>romide,  the  compound  MgBr,,3CH,CH0  (Men- 
•chutkin,  Zeitsch.  anozg.  Chem.  53,  26) ;  with 
calcium  cyanide  it  forms  CfHioOcNtCa,  (Ffanzen 
and  Ryser,  J.  pr.  Chem.  88,  293) ;  compound 
with  KCN  {ef,  Eng.  Pat.  19463, 1913). 

BubstUution  Producis.-^The  action  of  chlo- 
rine on  aldehyde  has  been  studied  by  Wurtz 
(Annafen,  102,  93),  Wurts  and  Voigt  (Bull.  Soc. 
chim.  17,  402),  and  by  Pinner  (Annalen,  179, 
21 ;  Coblenz,  he, ;  Freundler,  Bull.  Soc.  chim. 
1,  (4)  66 ;  Freundler,  Compt.  rend.  143,  682). 
Pinner  finds  that  when  chlorine  is  passed  into 
ordinanr  aldehyde  at  10^  metaldehyde  and  par- 
aldehyde are  first  formed,  and  these  subsequently 
jrield  sttbstitution-deriyatiyes,  of  which  chloral 
IS  the  chief  product,  butyric  chloral  and  dichlor- 
aldehyde  bem^  formed  in  smaller  quantity.  The 
following  denyatiTes  have  been  prepiued:— 
CUofoldehyde  CH^a-CHO+iHiO  (Natterer, 
Monatsh.  3,  446) ;  with  potassium  cyanide  and 
ammonium  chloride,  3-chloro-a- hydroxy  pro- 
pionic add  is  formed  (Raske,  Ber.  45,  725) ; 
dichhraldehyde,     C^aa'CHO     (Grimaux     and 


Adams,  Bull.  Soa  chim.  34,  29  Wohl  and 
Roth,  Ber.  40, 212);  trichhraidehyde  (v.  Chloral). 

According  to  S.  Utheim  chloroform  is  readily 
formed  b^  acting  upon  aldehyde  with  bleaching 
powder  m  the  presence  of  water  (Eng.  Pat. 
116094). 

The  bromine  deriyatiyes,  and  the  action  of 
bromine  on  aldehyde,  have  been  examined  by 
Pinner  (Ber.  7,  1499,  and  Ic, ;  Bugarsky, 
Zeitsch.  phyaikal.  Chem.  48,  63;  Freundlor, 
CJompt.  rencL  140, 1693 ;  Mauguin,  Compt.  rend. 
147,  747).  Reactions  of  dibromoacetMdehyde 
[cf,  Mylo,  Ber.  45,  046). 

Aidthyde  bhte  is  obtained  by  treating  para- 
rosaniline  with  sldehyde  or,  better,  paraldenyde 
in  aqueous  acid  solution,  and  precipitating  the 
dye  with  sodium  chloride.  A}  is  soluble  in 
alcohol  and  ether,  and  when  treated  with  strong 
hydrochloric  acid  is  conyerted  into  a  reddish 
yellow  base  which  shows  all  theproperties  of  a 
rosaniline  dye  (Qattermann  and  Wiohmann,  Ber. 
22,  227).  By  slightly  yaryins  the  conditions  in 
the  preparation  of  aldehyde  blue,  aldehyde  green 
can  also  be  obtained  (Miller  and  Pluchl,  Ber.  24j 
1700).  P.  A.  M. 

ALDEHYDE  OREEN  v,  Triphenylmbthanb 

OOLOUBI»Q  MATTBBa. 

ALDEHTDINE  v.  Bonb  oil. 

ALDEHTDINES.  Compounds  formed  by  the 
condensation  of  ortho-diaxnines  with  aldehydes 
(Ladenbuig,  Ber.  10,  1126)  (v.  Amines). 

ALDER  BARK.  {Aune,  Fr. ;  ErU,  Get) 
Alnua  glulinoea  (Gaert.).  Used  for  tanning  and 
dyeing.  The  percentage  of  tannin  yaries  from 
16  to  18  (Eitner,  Zeit.  f.  d.  Chem.  Qrossgew. 
3,  668  ;  4,  279). 

The  tannin  appears  to  be  a  methvl  tannin 
like  that  of  the  otkk;  it  giyes  a  readish-blue 
precipitate  with  ferrous  acetate,  an  olive-green 
precipitate  with  ferrous  sulphate,  and  is  precipi- 
tated by  a  gum  solution. 

A  solution  of  the  bark  is  employed  for  ob- 
taining black,  greys,  and  browns  on  linen ;  in 
Germany  for  reds ;  and  in  Kamchatka  for 
colouring  skins  a  red  tint. 

ALDOFORH.    A  formaldehyde  preparation. 

ALDOL  {fi-hudroxybtUyric  afdehtfoe  ;  hvtanol' 
S-oQ  CH,CHOHCH,-CHO  was  first  obtained 
by  Wurtz  in  1872.  It  is  produced  by  the 
action  of  cold  dilute  hydrochloric  acid  or  other 
condensing  agents,  such  as  alkali  acetates, 
carbonates  or  bicarbonates,  or  zinc  chloride 
in  aqueous  solution,  on  aoetaldehydc. 

200  grams  acetaldehyde  at  0^  C.  are  dropped 
into  20^  grams  water  at  0°  C.  and  10  grams 
potassium  carbonate  are  gradually  added.  The 
mixture  is  allowed  to  stand  for  12-18  hours  at 
10°  C,  then  shaken,  first  with  an  equal  yolume 
of  ether,  and  again  with  half  its  yolume  of  ether. 
The  aqueous  solution  is  exactly  neutralised  with 
hydrochloric  acid  and  again  extracted  with  half 
its  yolume  of  ether.  The  ether  extracts  are 
then  united,  the  ether  distilled  ofiF,  and  the 
residue  distilled  in  vacuo,   (Cf.  art.  Aldehyde.) 

Aldol  is  a  colourless  liquid  which  boils  at 
83°  (20  mm.),  and  has  a  specific  gravity  of  1*121 
at  0°.  It  is  miscible  with  water  and  alcohol. 
When  distilled  under  atmospheric  pressure  it 
loses  water  and  passes  into  crotonaldehyd^ 
CHs'CH  r  OH-CHO ;  a  similar  result  being 
obtained  by  heating  it  to  100°  C.  with  water 
containing  a  small  amount  of  sodium  hydroxide, 


112 


ALDOL. 


As  an  aldehyde,  it  rednoes  an  ammoniacal 
solution  of  silver  nitrate. 

On  standing  for  some  time  aldol  becomes 
Tisoons,  and  aner  some  days  solidifies,  passing 
into  the  solid  polymeric  form  known  as  pardldol. 
This  form  melts  at  82®  C,  and  on  rednction  with 
alominiixm  amalgam  yields  i9-bntylene  glycol 
CH.CHOHCHTSHjOH. 

The  above  compound  fumishes  an  example 
of  the  so-called  aldol  condensation/  which 
has  been  studied  at  length  by  von  Lieben  and 
his  pupils  (Monatsh.  1901,  22,  289),  and  the 
requisite  condition  for  such  a  reaction  Is  that 
the  carbon  atom"  adjacent  to  the  oarbonyl 
sroup  of  the  aldehyde  should  be  united  to  at 
foast  one  hydrogen  atom,  although  this  need 
not  be  the  case  when  the  condensation  occurs 
between  two  different  aldehydes,  e.g, 

(CH,),C-CHO+R,CH-CHO 

=(CH,),C-OHOH-C(Ri)CHO 

A  similar  t^npe  of  reaction  is  also  possible 
between  aldehyoes  and  ketones,  which  fulfil  tiie 
suitable  conditions. 

As  a  class,  the  aldols  are  colourless  liquids 
which  readily  polymerise  on  standing.  These 
polymerides  show  the  same  chemical  reactions 
as  the  liquid  forms,  and  are  partially  recon- 
verted into  such  forms  on  distillation  tn  vactu>. 
When  distilled  under  atmospheric  pressure  the 
aldols  decompose,  partiy  into  the  constituent 
aldehydes  from  which  they  were  produced,  and 
partiy  into  the  corresponding  unsaturated 
aldehyde  (bv  loss  of  water). 

AIiDOSES  V,  Oarbohtdbatbs. 

ALE  V.  Bbbwino. 

ALEHBROTH,  SALT  OF*  A  compound  of 
mercuric  chloride  and  sal  ammoniac 

2NH4Gl,HgCl^aO 

formed  by  mixing  the  two  salts  in  suitable 
proportions.  Also  called  by  tne  alchemiBts  Salt 
of  Wisdom. 

ALEUDRIN.  Trade  name  for  carbamio 
acid  ester  of  aa-diohloroiaopropyl  alcohol. 

ALEURTTES  CORDATA  (Steud.).  The  seeds 
of  this  euphorbiaceous  plant,  which  is  found 
laigely    in    Japan,    yield    Japanese    wood-oil 

{q.V.), 

ALEUBHIG  AGID  «.  Lao,  Art,  RBsnrs. 


ALEURONE  GRAINS*  Oiganised  eranulea 
deposited  in  the  cells  of  many  seeds  of  plants, 
generally  near  the  exterior,  in  which  the  proteins 
are  mainly  concentrated.  They  were  so  named 
bv  Hartig,  who  first  described  them.  in.  many 
plants,  the  aleurone  grains  possess  the  shape  of 
crystals.  Botanists,  indeed,  r^ud  tiiem  as  con- 
sisting of  two  parts :  (1)  a  crystalloid,  crystal- 
like protein  body,  and  (2)  one  or  more  rounded 
gldbotds  mainly  composed  of  mineral  matter,  in 
which  phosphoric  acid,  lime,  and  magnesia  are 
usualhr  the  laigest  conistituents. 

When  the  aleurone  grains  exhibit  the  form 
of  crystals,  it  is  generaUy  found  that  thcjy  are 
soft  and  swell  up  if  treated  with  weak  aods  or 
alkalis.  The  tonn  *  crystalloid,*  as  used  by 
botanists  in  this  connection,  has  reference  to 
the  appearance  of  the  aleurone  grains,  and  not 
to  their  property  of  diffusion  when  dissolved 
throuff h  membranes.  According  to  Tschireh  and 
Kritzfer  (Ghem.  Zentr.  1900,  ii.  685),  the  aleurone 
grains  of  a  variety  of  phmts  consist  mi^ily  of 

?:lobulins.  The  crystalloids  consiBt  of  at  least 
wo  globulins,  which  are  soluble  in  dilute,  but 
Insoluble  in  concentrated  saline  solutions  {e.g, 
ammonium  sulphate,  sodium  chloride  with  trace 
of  acetio  acid,  potassium  dihydro^en  phosphate). 
A  small  amount  of  an  albumoee  is  also  probably 
present.  The  globoids  contain  a  globulin  and 
mineral  matter,  especially  calcium,  magnesium, 
and  phosphoric  acid;  they  are  soluble  in  con- 
centrated solutions  of  ammonium  sulphate, 
acidified  sodium  chloride,  or  potassium  dihy- 
drogen  phosphate.  The  grains  with  their  en- 
closures are  reserve-food  materials  which  are 
consumed  when  the  seed  germinates.  They 
originate  as  liquid  '  vacuoles,'  in  which  an  in- 
creasing amount  of  protein  material  is  gradually 
deposited.  The  germinating  power  of  seeds 
probably  dej>ends  upon  the  solubility  of  the 
crystalloids  m  dilute  sodium  chloride  solutioiL 

According  to  Postemak  (Compt.  rend.  1905, 
140, 322),  aleurone  srains  often  contain  anhydro- 
oxymethylene  diphosphoric  add,  or  inositol 
phosphoric  acid  0tH«(P04H,)c  (j^ytin).  He 
found  the  following  amounts  of  nitrogen  and 
mineral  substances  in  the  aleurone  grains  of 
(1)  spruce  fir,  (2)  sunflower,  (3)  hemp,  (4)  white 
lupin:— 


N 

K 

Ca 

Mg 

Fe 

l£n 

P 

8 

■ 

81 

1. 

12-97 

2-60 

0-37 

1-25 

0-09 

0-25 

2-67 

0-64 

0-36 

2. 

10-22 

2-20 

0-33 

1-46 

0-05 

trace 

2-78 

0-64 

0-24 

3. 

12-88 

2-71 

0-27 

1-67 

0-05 

trace 

3-83 

0-81 

0-36 

4. 

10-70 

^~- 

0-11 

0-28 

-"" 

Oil 

0-61 

— ~ 

0*01 

Sodium  and  chlorine  were  not  found.    H.  I. 

ALFA  V,  Halfa. 

ALFALFA.  The  Spanish  name  for  lucerne, 
Medieago  sativa  (Linn.). 

ALFORHIN.  A  10  p.c.  solution  of  basic 
aluminium  formate. 

ALGA.  ( Varech  or  Alguea,  Pr. ;  Algen,  Ger.). 
A  class  of  ciyptogamous  plants  including  the 
green,  brown,  and  ted  seaweeds  and  vegetable 
plankton  growing  in  sea- water,  and  allied  mainly 
green  fresh-water  plants,  including  diatoms, 
desmids,  and  *  conferva  *-like  forms.  Many  of 
the  salt-water  species  are  edible ;  none  of  them 


is  poisonous. 

Rhodymenia  palmata  (Linn.)  (dulse,  dylish,  or 
delliah)  and  Alaria  ucuienta  (murlins)  are  used 
as  food  by  the  peasantry  of  the  Highlands  and 
of  Ireland.  Parpkyra  laetntdto  (Lightf.)  (laci- 
niated  purple  laver),  very  abundant  on  the 
British  coasts,  is  sold  in  England  as  laver,  in 
Ireland  as  sloke,  and  in  Scotland  as  slaak. 
Chondrua  crispns  (Linn.)  (carrageen,  Irish  or 
pearl  moss)  is  collected  on  the  west  coast  €d 
Ireland,  and  is  frequently  used  there  by  painters 
and  plasterers  as  a  substitute  for  size.  It  is 
also  used  in  making  jellies,  &c.,  in  medicine; 


ALIZARIN   AND  ALLIED  COLOURING   MATTERS. 


nn 


and  a  thick  mucilage  §cented  with  aome  prepared 
spirit  is  sold  as  *  bandoUn/  '  fixature/  or 
'  dytphitiqoe,*  and  is  employed  for  stiflfemng  silks. 

Amongst  other  algs  naying  an  economic 
value  are  Ceylon  moss  or  edible  moss  {Oracilaria 
lichenoides),  fonnd  in  the  Indian  archipelaffo; 
the  agar-agar  of  Malacca,  or  acal-agal  of  China, 
which  is  derived  from  OraeSaria  lichenoides, 
Eucheuma  spinoeum  (linn.)  and  otiier  dign 
{Me  Aoab).  The  sabstanoe  is  now  much  used 
in  bacteriological  research  as  a  nutrient  jelly ; 
for  gnmmine  silks,  paper,  fta,  and  for  making 
a  paste  not  uable  to  oe  eaten  by  insects. 

Manna,  or  mannite,  can  be  obtained  from 
Laminaria  saechanna  (Lamx.)  or  suffar  wrack, 
found  on  sandy  shores,  attached  to  pebbles. 

In  Yexo  (Japan)  different  species  of  Laminofia 
and  Arthnihamnus  are  collected  for  use  as 
edibles,  and  in  large  quantities  as  raw  material 
for  iodine  manufaotiue  and  potassium  salts. 
Other  varieties  commonly  usea  as  a  source  of 
iodine  are  Ecklonia  cava  and  B.  fnctfcUs. 

Alginic  acid  (Algin)  is  prepared  from  Macro- 
cystis  jnfrifera,  found  on  the  Pacific  coast  of 
America,  by  treating  a  sodium  carbonate  extract 
with  hydrochloric  acid,  redissolving  in  sodium 
carbonate  and  reprecipitatmg  with  acid  several 
times,  then  dissolving  again  in  sodium  carbonate, 
purifying  the  sodium  alginate  by  dialysis, 
decomposing  it  with  hycuochlorio  acid,  and 
purifying  the  alginic  add  by  dialysis.  Alginic 
acid  dried  at  lOO""  will  absorb  200  to  300  tunes 
its  weight  of  water.    Its  optical  activity  is 

[al^^*^'=  169-2®.  The  sugars  produced  by  hydro- 
lysis with  2  p.c.  hydrochloric  add  gave  a  yellow 
osasone,  m.p.  164^-155°,  dosely  resembling 
/-xylosasone,  and  also  a  red  amorphous  osazone. 
Algin  probably  consists  of  a  complex  com- 
posed of  compounds  of  the  pentosan  type  and 
cetlnloae.  It  has  weakly  acid  properties,  and 
the  sodium  salt  precipitates  many  metals  from 
solution  (Hoagland,  J.  Agric.  Research,  1915, 
4, 89 ;  J.  Biol.  Chem.  1915, 23, 287.  See  Iodinb. 

The  following  table  shows  the  oomposition 
of  varions  species  of  algss ;  the  quantity 
of  nitrogen  in  some  of  them  is  remarkably 
large : — 


Chondnu  eritpua,  bleached 
from  Bewlay  Evans 

Chondniserieput.  bleached 
second  experiment .     . 

Chtmdrua  en$pu$,  un- 
bleached Ballycastlc    . 

ChondruM  critpuM,  un- 
bleached, second  ex- 
periment   .        .        . 

OifforHna  mamiOota,  Bal- 
lycastle 

LamdHoria  digitata,  or 
dulse  tande 

Rkodymema  pahnata 

Porphffra  iadniata  .         . 

iSareaph^lHe)  eduU* 

AUma  etetderUa 


Water 


17-92 
10-70 
21-47 

1000 

21-55 

21-38 
!  ie-50 
17-41 
10-61 
1701 


Dry 

matter 


Per 
cent, 
nitro- 
gen in 
dry 
matter 


82-08 
80-21 
78-68 

3004 

78-46 

78-62 
88-44 
82-60 
80-80 
80-00 


Protdii 
con- 
tained 
In  dry 
matter 


1-684 
1-486 
2-142 

2-610 

2-108 

1-588 
3-466 
4-650 
8088 
2-424 


0-687 

0-281 

12-887 

16-687 

18-787 

0-026 
21-656 
20-062 
10-800 
16-160 


Vol.  L — T, 


Certain  of  the  Laminaria,  after  washing  to 
remove  salts,  are  found  to  be  suitable  as  fodder, 
and  when  mixed  with  hay  and  straw  in  lieu  of 
oats  are  readily  eaten  by  horses.  Although 
poorer  in  oarbohydrates  than  oats  the  seaweed 
IS  much  richer  in  protsin. 

In  addition  to  the  large  amount  of  chlorine 
in  marine  alg«  (up  to  38  p.c.  of  the  ash)  there 
are  often  not  inconsiderable  quantities  of  iodine, 
the  presence  of  which  is  responsible  for  the 
employment  of  seaweeds  in  the  oomposition 
of  certain  *  anti-fat '  specifics. 

Certain  algsB  are  characteristic  of  water  con- 
taining sewase  and  putrefactive  substances  in 
quantity,  and  some  alg«  play  an  important  rdk 
in  the  disinfection  of  poUuted  rivers. 

ALOAROBILLA.  Algarobilla  consists  of 
the  nods  of  Ceaaalpina  ^evifoUa.  The  tannin, 
whicn  appears  to  be  a  mixture  of  allagetannin 
and  g^otannin,  lies  in  semi-resinous  particles 
adhennff  loosely  to  the  somewhat  open  frame- 
work of  the  fibre.  It  is  one  of  the  strongest 
tannin  matters  known,  and  contains  on  the 
average  45  p.c.  In  character  it  resembles  divi- 
divi,  and  its  extract  is  somewhat  prone  to 
fermentation.  It  is  very  suitable  for  tanning 
and  also  for  dyeing  purposes. 

ALGAROfH,  POWDER  OF.  PiOvm  Alga- 
rothi,  English  Powder,  A  crystalline  oxy- 
chloride  of  antimony,  obtained  by  pouring  anti- 
mony chloride  into  hot  water,  used  m  the 
preparation  of  tartar  emetic  {v.  Antimony). 

ALGARROBIN.  A  natural  dve  product, 
obtained  from  the  wood  of  the  carob  tree,  Cera- 
tonia  siliqua,  found  in  the  Argentine.  Accord- 
ing to  a  report  of  the  United  States  Consul- 
General  at  Buenos  Ayres,  it  is  largely  employed 
in  the  Argentine  for  dyeing  khaki  cloth  for 
military  purposes,  and  some  quantity  is  also 
imported  to  the  Continent  of  Europe.  It  is 
said  to  dye  the  textile  fibres  a  lignt  brown 
colour,  thouffh  if  these  be  previously  mordanted, 
more  varied  shades  may  be  obtained.  As  it 
acts  also  as  a  mordant  lor  the  coal  tar  colours, 
it  would  appear  to  be  a  tannin,  and  may  be 
allied  to  eliagitannin,  as  its  name  suggests  (ef, 

ALO  ABO  VILLA,  /.C).  ATG.  P. 

ALGIN.  A  nitrogenous  body  obtained  from 
seaweed,  somewhat  rosembling  albumen  (t;. 
Alojs).  Used  in  the  sizing  and  finishing  of 
certain  textile  fabrics  as  a  substitute  for  Irish 
moss  (carrageen) ;  should  contain  from  4  to  6 
p.c.  of  alffinic  anhydride  (r.  Iodine). 

ALGIRON  {Alginoid  iron).  Trade  name  for 
an  iron  compound  of  alginic  acid  (from  seaweed) ; 
contains  11  p.c.  iron. 

ALGODONITE.  A  copper  arsenide  of  a 
steel-grey  colour.  Found  m  the  Lake  Superior 
copper-minins  district. 

ALGOL  COLOURS  v.  Alizarin  and  aliikd 
COLOURING  matters;   Vat  dyes. 

ALGOLAVE.  Trade  name  for  the  salicylic 
ester  of  propvl  oxyt«obutyric  acid. 

ALHAGf  CAMELORUM  (Fischer),  JAW  ASA, 
or  JAWANL  A  leguminous  thorny  shrub, 
widely  spread  from  Greece  to  dry  parts  of  India, 
where  a  drug  extracted  from  it  is  used  for 
rheumatism,  and  also  as  a  laxative  and  diuretic 
(Pharm.  J.  [3]  9,  146). 

ALIVAL.    lodo  hydroxirpropane. 

ALIZARIN  AND  ALLiro  COLOURING 
MATTERS.    i9e«  also  articles  on  ANTifftArBNR, 


114 


ALIZARIN   AND  ALLIED  COLOURING   MATTER& 


Anthsaquinonx,  Ghay  Root  Madder,  Methyl 
Aktebacene,  Vat  Dyes.  Madder,  Bvhia 
iinUoriat  which  was  for  a  Ions  time  used  on  a 
large  scale  in  the  *  Torkey-rea '  indastry,  con- 
tains two  colouring  matters,  aUzarin  and  pur- 
purin,  of  which  the  former  is  by  far  the  more 
important. 

Alizarin  is  not  found  ready-formed  in  the 
madder-root,  but  exists  there  as  a  gluooeide 
called  *  ruberythric  acid,*  which  when  allowed 
to  ferment,  or  when  boiled  with  dilute  acid, 
splits  up  readily  into  alizarin  and  glucose. 

The  colouring  matter  itself  was  first  isolated 
from  the  madder-root  in  1827  by  Colin  and 
Robiquet,  who  obtained  it  by  extracting  ground 
madder  with  hot  water  and  subliming  the  puri- 
fied extract  carefully  in  a  glass  tube. 

This  method  of  sublimation  was  not  con- 
sidered sufficient  proof  of  the  existence  of  alizarin 
in  madder,  and  it  was  not  till  Schunck  suc- 
ceeded in  isolating  this  substance  by  chemical 
means  from  the  madder  extracts  used  by 
dyers  that  this  important  point  was  definitely 
settled. 

In  awrigning  the  correct  formula  to  alizarin, 
considerable  difference  of  opinion  existed  at  first, 
owing  no  doubt  to  some  extent  to  the  difficulty 
experienced  in  obtaining  alizarin  in  a  condition 
pure  enough  for  accurate  analysis. 

Schunck  proposed  the  formula  C^4H|,04, 
whilst  Strecker  belieTed  it  to  be  Oi^jOm  and 
related  to  *  chloroxynaphthaUc  acid '  (chloro- 
hydroxynaphthaquinone),  a  derivative  of  naph- 
thalene, since  both  these  substances  on  oxidation 
yield  phthalic  acid. 

Strecker's  formula  was  the  more  generally 
accepted  by  chemists,  and  chloroxynaphthaUc 
acid  was  looked  utxm  as  being  simply  chlorinated 
alizarin,  the  two  oodles  being  thus  related : 

c,oH,ao, 

Chlorinated  alisarin  or 
OhlorozyiiAphtliaUo  add. 


by  Graebe  to  be  related  to  naphthalin  in  much 
the  same  way  as  chloranil  was  to  benzene,  •'.«.  to 
be  a  derivative  of  naphthaquinone. 

Soon  after  this  the  attention  of  Graebe  and 
laebermann  was  turned  to  alizarin,  which  they 
also  thought  might  belong  to  the  quinone  series. 

In  determining  the  constitution  of  this 
substance,  the  first  step  was  to  obtain  some 
information  as  to  the  nature  of  the  hydro- 
carbon from  which  alizarin  was  derived,  and 
this  was  done  in  the  following  wa^:  Alizarin 
prepared  from  madder  was  mixed  with  zinc-dust 
and  heated  strongly  in  a  furnace,  according  to 
Baeyer's  method  of  reducing  benzenoid  com- 
pounds, and  in  this  way  a  crystalline  hydrocarbon 
was  obtained  having  the  composition  C,4H,o, 
which  on  examination  was  founa  to  be  identi<^ 
with  anthracene,  a  hydrocarbon  previously  ob- 
tained by  Dumas  and  Laurent  from  coal  tar. 
Using  the  information  already  obtained  in  the 
research  on  quinone,  Graebe  and  Liebermann 
now  assumed  that  alizarin  must  be  a  dihydroxy- 
quinone  of  anthracene,  the  relation  of  these 
substances  to  one  another  being  seen  from  the 
following  formulas : — 


C14H1P 
Anthracene. 


C,«H,0,  ChH.O,(OH), 

Anthraqninooe.  Alizarin. 


C,oH,0, 
Aliuiin. 


In  order  to  prove  the  relation  supposed  to 
exist  between  these  two  substances,  it  was  only 
necessary  to  replace  the  chlorine  atom  in 
chloroxynaphthaUc  acid  by  hydrogen,  when 
alizarin  should  result. 

Hiis  operation  was  eventnaUiy  accomplished 
by  Martins  and  Grien,  who  obtained  thus  a 
substance  of  the  formula  CioHgOg,  which  was, 
however,  not  identical  with  alizarin,  and  wta 
therefore  supposed  to  be  isomeric  with  it. 

Following  these  experiments  of  Martins 
and  Griess,  Graebe,  in-  1808,  commenced  his 
research  on  quinones,  the  working  out  of  which 
led  not  only  to  results  which  proved  beyond  a 
doubt  what  the  chemical  nature  of  alizarin 
really  was,  but  also  eventually  resulted  in  the 
artificial  production  of  this  important  colouring 
matter.  In  pursuing  this  investigation  Graebe 
succeeded  in  preparing  chloranil  C«Cl«Oj,  by 
treating  phenol  with  potassium  chlorate  and 
hydrochloric  acid,  and  in  acting  on  this  with 
caustic-  potash  he  found  that  two  of  the  atoms 
of  chlonne  in  this  compound  became  replaced 
by  (OK),  producing  the  potash  salt  of  chloranilic 
add  C«C1,(0K)|0.,  a  change  the  knowledge  of 
which  proved  to  be  of  the  utmost  importance 
in  his  subsequent  experiments  on  the  artificial 
production  of  alizarin. 

Chloroxynaphthalic  acid  was  now  considered 


Having  thus  obtained  anthracene  from  ali- 
zarin, it  was  now  only  necessary  to  reverse  the 
operation  and  convert  anthracene  into  alizarin, 
and  the  problem  of  the  artificial  production  of  a 
vegetable  colouring  nuitter  would  be  solved  for 
the  first  time. 

In  1862  Anderson,  while  investigating  anthra- 
cene, obtained  from  it  by  oxidation  a  substance 
of  the  formula  Cifi  fi^,  which  he  named  ox- 
anthracene. 

In  this  substance  Graebe  and  Liebermann 
recognised  the  quinone  of  anthracene  (anthra- 
quinone),  the  first  step  in  the  synthesis  of  alizarin 
from  anthracene,  and  in  order  to  convert  this 
quinone  into  alizarin  all  that  was  necessary  was 
to  replace  two  atoms  of  hydrogen  in  it  by 
hydroxyl,  an  operation  which  is  easily  done  in 
the  following  way  : — 

Anthraquinone  when  heated  with  two  mole- 
cules of  bromine  in  sealed  tubes  is  converted  into 
dibromanthraquinone,  thus : 

C,4H,0,-f2Br,=Ci4H,Br,0,+2HBr. 

This  substance  when  heated  with  potash  ex- 
changes each  of  its  bromine  atoms  for  (OK),  yieltl- 
ing  the  potash  salt  of  alizarin,  C|4H,(0K),0,,  a 
reaction  which  is  precisely  similar  to  the  forma- 
tion of  chloranilate  of  potash  from  chloranil  as 
described  above.  The  potassium  alizarate  thus 
obtained,  when  decomposed  with  hydrochlorio 
acid,  yielded  alizarin,  and  thus  the  problem  of 
the  artificial  production  of  alizarin  was  solved. 

In  considering  this  synthesis,  periiaps  the 
most  remarkable  fact,  from  a  chenucal  point  of 
view,  is  that,  in  consideration  of  the  number  of 
possible  isomers  of  alizarin,  just  that  dibrom* 
anthraquinone  prepared  by  Graebe  and  Lieber- 
mann should  on  treatment  with  potash  have 
yielded  alizarin.  Had  this  not  Men  so,  the 
artificial  production  of  alizarin  would  no  doubt 
have  been  very  much  delayed. 

The  great  importance  of  alizarin  as  a  dyeing 
agent  induced  Graebe  and  Liebermann  to  patent 
this  process,  which  proved,  however,  to  be  of  no 
commercial  value,  owing  to  the  great  expense 


ALIZARIN   AND   ALLIED  OOLOUKINO  MATTERa 


115 


attending  the  nae  of  bFomine,  and  it  was  there- 
faro  desirable  to  find  some  new  method  which 
would  render  tiieir  disooTery  important  from  a 
manufacturing  point  of  view. 

This  was  Snt  aohieved  by  W.  H.  Perkin  >  in 
the  following  way  :^3ulphurio  acid,  as  is  well 
known,  forms  with  many  organic  bodies  com- 
pounds called  sulphonio  acids,  which  in  composi- 
tion simply  correspond  to  the  substance  acted 
on  plus  sulphuric  anhydride. 

Thus  benzene  CcTi,  when  treated  with  sul- 
phuric acid  yields  benzenesulphonic  acid 
C,H  ,SO,H ;  naphthalene  C^oH|^  naphthalene- 
sulphonic  acid  CiJRfiO^K.  When  fused  with 
caustic  potash  these  sulphonic  acids  are  split  up 
into  the  potassium  sut  of  the  corresponding 
phenol  and  potassium  sulphite,  thus  : 

C.HJSO,H+3KOH=C,H,OK+K;gO,+2H,0. 

Similarly  disulphonio  acids  when  fused  with 
potash  in  converted  into  dihydrio  phenols,  thus  : 

CcH4(SOsH)s-»0KOH»C6H4oK  -**  KiSOs-t'4H20. 
In  this  second  example  it  will  be  seen  that  a 
body  is  formed  which  bears  the  same  relation 
to  benzene  as  alizarin  does  to  anthraquinone, 
and  it  was  therefore  probable  that  if  anthraqui- 
none  were  subjected  to  a  similar  series  of  re- 
aetionSy  alizarin  would  result. 

The  great  obstacle  to  oarryins  out  this 
synthesis,  in  the  first  instance,  was  uie  remark- 
able stability  of  anthraquinone  in  genexal  and 
particularly  towards  sulphuric  acid,  which  is  so 
great  that  it  dissolves  in  moderately  hot  sul- 
phuric acid  without  change,  and  orystalliBes  out 
a^in  in  needles  on  ooolins. 

When,  however,  a  mixture  of  anthraquinone 
and  sulphuric  acid  was  heated  very  strongly, 
reaction  did  eventually  take  place,  the  product 
becoming  perfectly  soluble  in  water,  the  solu- 
tion now  containing  mono-  and  diaulphonic  acids 
of  anthraquinone. 

After  removing  the  excess  of  sulphuric  acid 
from  the  new  proauct,  it  was  mixed  with  caustic 
potash,  and  heated  to  about  180°. 

During  the  heating  the  melt  became  darker 
and  darlrar  in  colour,  and  eventusUy  almost 
black,  and  on  dissolving  this  in  water  a  rich 
purple  solution  was  obtamed  which  when  acidi- 
fied with  dilute  sulphuric  acid  gave  a  copious 
prechutate  of  alizarin. 

1^  great  obstacle  to  the  preparation  of 
alizarin — ^viz.  the  use  of  bromine— was  thus  re- 
moved, and,  as  the  future  has  proved,  a  process 
had  been  obtained  hv  whicn  this  coTourinff 
matter  could  be  manufactured  in  quantity  imd 
at  a  price  so  cheap  as  entirely  to  supersede  the 
old  method  of  dyemg  with  the  madder  root. 

Another  process  for  the  manufacture  of  arti- 
ficial alizarin  idiortly  afterwards  discovered  by 
W.  H.  Perkin,  and  lanely  used  by  him  on  a 
manufacturing  scale,  is  the  following  : — 

Anthracene  is  treated  with  chlorine  and 
thus  converted  into  a  beautifully  crystalline 
comjMund  called  diohloranthracene  Ci^HgCl,. 

This  substance  combines  with  Nordhausen 
sulphuric  acid,  forming  a  bright-green  solution, 
which  contains  a  sulphonic  acid  of  diohloran- 
thracene. When  heated  with  sulphuric  acid 
this  substance  imdeigoes  a  remarkable  change, 

*  It  should  be  mentioned  here  that  while  these  ex- 
pertmenta  were  in  proffress,  Caro,  Oraebe  and  Lleber- 
mann  were  Investigating  the  sane  reaction  In  Germany. 


hydrochloric  acid  and  sulphurous  acid  are 
evolved,  and  a  disulphonic  acid  of  anthraquinone 
formed,  thus 

Ci,H,C1,(S0,H),+H;S04 
Dichlorantiiraoene-dUulphonic  acid. 

«CuH,0,(S0,H),+2Ha-|-S0, 
Anthraquinone  disulphonic  add. 

This  anthraquinone  disulphonio  acid  when 
fused  with  potasn  yields  alizarin. 

Although  other  methods  for  the  production 
of  alizarin  have  since  been  deviseo,  there  is 
little  doubt  that  the  bulk  of  the  alizarin  of 
commerce  is  still  obtained  from  *  silver  salt,'  the 
name  given  in  the  works  to  sodium  anthra- 
q  uinone-2-sulphonate. 

Alizarin,  purpurin  and  similar  dyes  will  not 
dye  unprepared  fabrics ;  these  must  first  of  all 
be  mordanted. 

The  mordants  used  in  this  case  consist  of 
metallic  hydroxides — e,g,  of  aluminium,  iron, 
and  chromium.  Chloride  of  tin  (tin  crystals)  is 
also  extensively  employed. 

With  alumina  mordants  alizarin  produces 
shades  of  red  and  ))ink ;  with  iron  mordants, 
shades  of  black  and  purple;  with  chromium 
mordants,  a  dull  purple ;  and  with  tin  crystals  a 
bright  yellowish  orange.  These  mordants  may 
also  be  mixed  and  thus  a  large  variety  of  different 
shades  produced.  A  description  of  the  method 
of  application  of  these  various  mordants  and  the 
processes  employed  in  dyeing  with  alizarin  will 
DC  found  in  the  article  Dyeing. 

Since  the  first  production  of  artificial  alizarin 
on  the  large  scale,  the  study  of  this  substance 
and  of  the  various  colouring  matters  related  to 
it  has  received  a  large  amount  of  attention  at 
the  hands  of  chemists,  the  result  being  that  a 
considerable  number  of  derivatives  of  anthra- 
quinone have  been  prepared  and  examined. 

Most  of  these  are  either  colouring  matters 
themselves,  or  easily  converted  into  such, 
several  of  them  being  obtained  on  the  large  scale 
in  the  manufacture  of  alizarin. 

These  derivatives  may  be  divided  under  the 
following  heads : — 

(1)  Sulphonio  acids  of  anthraquinone. 

(2)  Monohydroxyanthraquinones. 

(3)  Dihydroxyanthraquinones. 

(4)  Trihydroxyanthraquinones. 

(5)  Higher  hvdroxylated  anthraquinones. 
In  this  article  are  included  the  two  dyeing 

matters,  Gallein  and  GoeruleTn,  which  are  very 
closely  allied  to  alizarin  in  tinctorial  properties, 
and  eUso  a  brief  description  of  some  acid  wool 
dyes  derived  from  hydroxyanthraquinones. 

Solphonle  adds  of  anthnMioinona. 
Anthraqnlnone-I-  (or  a-)  sulphonio  add 

C.H,<gg>C.H,SO,H  (1) 

It  is  a  remarkable  instance  of  the  influence 
of  a  catalyst  that  whilst  anthraquinone  ordi- 
narily sulphonates  in  the  2-  position,  yet  in  the 
presence  of  quite  small  amounts  of  mercury  the 
1-  position  is  almost  exclusively  attacked. 

In  preparing  anthraquinone- 1 -sulphonic  acid 
100  parts  of  anthraquinone  are  heated  for  three 
hours  at  130°  with  110  parts  of  sulphuric  acid, 
containing  29  p.c.  sulphuric  anhydride,  and 
0'5  part  (»  mereury. 

The  free  acid  is  easily  soluble  in  alcohol  and 


116 


AUZARIN   AND  ALLIED  COLOURING  MATTERS. 


water,  its  lead,  bariom,  and  strontiam  taltB  are 
▼ery  inaolnble  in  hot  water.  The  oaloium  salt 
is  feirly  soluble,  but  oiTstaUises  on  heating  the 
eolation.  Thepotassinm  salt  occurs  in  glistening 
yeUow  leaflets. 

Aiitlin4|iil]ioiie-l  :  6-  and  -1  :  8-dliillplioiiie 
aetds 

^^     80,H  SO,H^^     80,H 

QPO-OOO 

The  further  snlphonation  of  the  a  add  in 
presence  of  mercury  leads  to  the  formation  of 
1  : 6-  anthraquinone  disulphonic  add,  mixed 
with  1  :  8-  and  1 :  7-  adds.  The  same  mixture 
is  produ(»d  by  the  direct  snlphonation  of  anthra- 
quinone (100  parts)  with  200  parts  of  sulphuric 
acid  containing  40  p.c.  sulphur  tiioxide,  m  the 

Eresence  of  mercury  (1  part)  at  160®  for  one 
our.  The  mixture  of  adds  is  converted  into 
calcium  salt  and  fractionally  crystallised.  The 
caldum  salt  of  the  1 : 8-  acid  is  least  soluble, 
the  middle  fraction  is  the  largest  and  consists 
of  1  : 5-,  whilst  the  caldum  salt  of  1:7-  is 
easily  soluble. 

Alternatively  and  j^referably  the  adds  ma^ 
be  separated  by  takmg  advantage  of  their 
different  solubifities  in  sulphuric  add.  The 
reaction  mixture  obtained  in  tne  above  described 
preparation  would  be  mixed  with  100-200 
parts  of  sulphuric  add  (60^  Be.),  and  the  1 : 6- 
acid  is  then  obtained  in  the  crystalline  condition 
and  collected  on  asbestos.  The  1 :  8-i8omeride 
is  precipitated  from  the  filtrate  on  the  addition 
of  half  its  volume  of  water.  Both  acids  are 
converted  into  potassium  salts  by  adding 
potassium  chloiioe  to  their  hot  aqueous  solu- 
tions. The  suooees  of  these  sulphonations 
depends  very  largely  on  the  even  mstribution 
of  the  mercury  catalyst  throughout  the  mass, 
and  to  attain  this  enA  the  mercury  may  be 
introduced  in  the  f  omn  of  yellow  mercuric  oxide, 
or  a  merouroufl  or  merouno  salt,  and  intimately 
mixed  with  the  anthraquinone  emploved  in  the 
operation.  The  discovery  of  a  simple  method 
of  manu&Msture  of  these  a-sulphomc  adds  of 
anthraquinone  led  to  a  mat  development  in 
the  anthracene  series  of  dyes,  especially  in 
connection  with  the  production  of  acid  wool 
dyes  of  the  type  of  Alizarin  Saphirol,  and  a  whole 
series  of  vat  dyes,  for  example,  the  Algol 
colours  {aee  Vat  Dyes). 

The  a-Bulphonio  adds  may  also  be  obtained 
by  the  oxidation  of  the  su^ho-derivatives  of 
anthracene.  Thus  anthracene  a-  and  6-disul- 
phonic  acids  jrield  anthraquinone- 1 : 8-  and 
I  :  5-disulphonic  acids  reftDeotively  on  treat- 
ment witn  nitric  add.  Gmorine  or  bromine 
atoms  in  the  alpha  position  in  the  anthra- 
quinone nucleus  may  be  displaced  in  favour  of 
the  sulpho-group  by  treatment  of  these  halosen 
derivatives  with  aqueous  sodium  sulphite. 
Neither  of  these  methods  possesses  technical 
importance.  * 

Literature. — ^Liebermann  and  Dehnst  (Ber. 
12,  1288),  Iljinsky  (Ber.  36,  4194),  Schmidt 
(Ber.  1904,  37,  66  ;  Enz.  Pat.  10242  and  13808, 
1903;  D.  R.  P.  167123,  164292,  and  167169), 
Cain  (Intermediate  Products  for  Dyes,  Mac- 
miUan.  1918,  243). 


A]itlini4iiliione-2.  (or  0-)  folplioiito  aM 
C.H,<gg>C.H,(80,H). 

This  add  is  formed  together  with  a  certam 
amount  of  anthraquinone  disulphonic  add  by 
heating  anthraquinone  with  fuming  sulphuric 
add  to  170°  or  with  ordinary  sulphuric  acid  to 
2«)°-260*». 

In  preparing  it  a  mixture  of  one  part  of 
fuming  sulphuric  acid  (oontaininff  4(MM)  p.o. 
anhycmde)  and  l-lj  parts  of  anthraquinone  is 
gradually  heated  to  about  lOO'^  and  kept  at  this 
temperature  for  eisht  or  ten  hours,  the  whole 
bednff  well  stirred  during  the  operation. 

The  product  thus  formed  consists  chiefly  of 
the  monosulphonic  add  together  with  a  little 
disulphonic  add  and  unchanged  anthraquinone. 
On  diluting  with  water  the  anthraquinone  sepa- 
rates out,  and  can  easily  be  filtered  off,  leaving 
the  sulphonic  adds  in  solution.  In  order  to  sepa- 
rate the  mono-  from  the  disulphonic  add  the 
dear  filtrate  is  nentralised  wiUi  carbonate  of 
soda  (or  caustic  soda).  This  causes  the  difliculUy 
soluble  sodium  salt  of  anthraquinone  mono- 
sulphonic acid  to  separate  out,  leaving  the 
easily  soluble  salt  of  the  disulphonic  add  in 
solution. 

The  pasty  mass  obtained  on  neutralising 
with  soda  is  thoroughly  pressed,  washed  with  a 
little  water,  and  then  &  required  pure  recrystal- 
lised  from  this  solvent.  In  this  way  a  beautiful 
brilliant  white  scaly  crystalline  mass  is  obtained, 
which  consists  of  pure  sodium  anthraquinone 
monosulphonate,  the  so-called  'silver  salt*  of 
the  alizarin  manufacturer.  This  salt  crystal- 
lises with  1H,0,  and  100  parts  of  water  dis- 
solve 6*59  parts  at  18",  and  18-88  parts  at 
100^ 

The  free  add  obtained  by  the  addition  of  an 
add  to  the  soda  salt  crystallises  in  plates.  It 
is  very  easily  soluble  in  cold  water  and  alcobcd, 
but  almost  msoluble  in  ether. 

Diinschmann  has  pointed  out  that  adds 
other  than  the  iB-add  are  obtained  in  this  pro- 
cess and  that,  after  the  greater  part  of  the 
'silver  salt*  has  separated,  further  concentra- 
tion gives  a  product  containing  the  two  mono- 
sulphonic acids  of  anthraquinone  mixed  with 
the  2 : 6-disulphonic  acid.  The  final  mother 
•liquor  contains  the  2 : 7-diBulphonic  acid.  A 
hot  saturated  solution  of  the  mixed  adds  is 
treated  with  one-tenth  of  its  volume  of  a  46  p.c. 
solution  of  sodium  hydroxide  and  cooled  to  66°- 
60°,  whereupon  most  of  the  2  :  6-acid  sefiaratea 
as  sodium  salt,  whilst  on  ooolins  the  mother- 
liauor  sodium  anthraquinone-1-snlphonate  rm- 
tallises.  To  avoid  the  formation  of  these  by- 
products Grandmougin  employs  aa  sulphonating 
agent  an  acid  containing  only  16  p.c.  80a  at 
150^,  and  under  these  conditions  it  is  stated 
that  only  the  i9.-acid  \a  produced.  - 

When  fused  with  caustic  soda,  this  add  (or 
rather  its  sodium  salt)  gives  first  hydroxy  anthra- 
quinone     C,H^<^Q>CtH,0H,      and      then 

alizarin  ;  and,  as  will  be  shown  later  on,  alizarin, 
when  prepared  on  a  manufacturing  scale,  is  in- 
variably K>rmed  from  the  monosulphonic  add  of 
anthraquinone,  not  from  the  disulphonic  acid 
as  might  be  expected.  The  reason  for  this  is 
that    on    fusing    hydroxyanthraquinone    with 


ALIZARIN  AND  ALLIED  COLOURING  MATTERS. 


117 


caortic  aoda,  •  conimuoiis  process  of  oxidation 
aod  TCdootion  is  carried  on,  the  change  being 
represented  by  the  following  equation :— - 

GuH,(ONa)0.+NaOH+0 
Sodiom  monohydroxyanUtfaqiiinoiiate. 

-C"H.(ggt)0.+0H. 
Sodium  allxwate. 

the  oxygen  being  rapplied  at  the  expense  of  a 
part  of  the  hydroxyanthraquinone  which  is 
thereby  reduced  to  anthraqainone.  On  the 
huge  scale  this  reduction  is  prevented  by  the 
use  of  chlorate  of  potash  in  the  fusion. 

Literature. — Oraebe  and  liebermann  (An- 
nalen,  ^60,  131 ;  212,  44 ;  Ber.  7,  805) ;  Grand- 
mougin  (Lehrbnch  der  Farben  Chemie,  4th  ed. 
1913,  260) ;  Dunsohmann  (Ber.  37,  321). 

A]ithriU|iibione-2 : 6-  and  2 : 7-disiilptaoole 
adds  (a-  and  i9-disulphonio  adds  xeBpeotiYely), 


80^\/\co/\/ 


VNcoA/' 


In  the  presence  of  the  mercury  catalyst  anthra- 
qulnoiie-2-sulphonio  add  is  attaclced  in  the 
positions  6  and  8,  yielding  anthraquinone-1 :  6- 
and  1 : 7-disulphonic  adds,  the  constitutions 
of  which  have  oeen  proved  by  conversion  into 
the  corresponding  hydroxvanthraquinones  by 
heatinff  under  pressure  with  milk  of  lime.  On 
the  otner  hand,  sulphonation,  in  the  absence  of 
mercury,  of  dther  anthraquinone  or  its  jS-sul- 
phonio  add,  yields  a  mixture  of  the  2 : 6-  and 
2 : 7-adds.  The  higher  the  temperature  the 
greater  the  proportion  of  the  a-  or  2 : 6-acid 
which  is  formed. 


(1)  A  mixture  of  10  kilos  of  anthraquinone 
and  20  to  30  kilos  of  fuminff  sulphuric  acid, 
containing  46-50  p.c.  SO,*  is  neated  to  a  tem- 
perature of  IW-YIO**  unUl  a  sample  taken  out 
IB-  found  to  dissolve  completely  in  water.  The 
product  is  then  heated  another  hour  to  convert 
any  mono-  into  disulphonic  add,  poured  into 
water,  neutnJised  with  caustio  soda,  and 
evaporated. — (2)  10  kilos  of  anthraquinone,  12 
kilos  of  hydrogen  sodium  sulphate,  and  40 
kilos  of  ordinary  concentrated  sulphuric  acid 
are  heated  under  pressure  for  nve  or  six 
hours  to  260°,  the  product  treated  with  water, 
and  the  adds  converted  into  sodium  salts  as 
above. 

In  concentrating  the  solution  of  the  sodium 
salt  obtained  by  either  ol  the  above  methods, 
the  sodium  salt  of  the  a-aoid  crystallises  out 
first,  the  more  readily  soluble  salt  of  the  i3-aoid 
remaining  in  the  mother-liquorSy  and  thus  by 
repeated  recrystallisation,  the  two  acids  are 
easily  separated  from  one  another. 

The  nee  adds  obtained  by  decomposing  the 
salts  bv  an  acid  are  botn  readily  soluble 
in  alconol  and  water,  but  insoluble  in  ether 
and  benzene ;  the  a-add  crystallises  in  small 
yellow  crystals,  the  /9-add  in  beautiful  yellow 
plates. 

The  salts  of  the  a-add  are  sparingly  soluble 
in  ivater  and  crystallise  with  difficulty  ;  those  of 
the  /3-add  are  readily  soluble  and  crystallise 
with  the  greatest  ease. 

The  TOdium  salt  of  the  a-aoid  crystallises 
with  7HaO,  that  of  the  ;3-acid  with  4H,0. 

Li/eniitfre.— Schultz  (Ghemie  des  Stein- 
kohlentheers,  709,  712);  Perkin  (Chem.  Soc. 
Trans.  1870,  133) ;  Graebe  and  Liebermann 
(Annaien,  160,  134) ;  Crossley  (J.  Amer.  Chem. 
Soc.  1915,  37,  2178). 

The  rdation  of  the  various  colouring  matters 
of  this  group  to  anthracene,  anthraquinone,  and 
its  sulphonic  acids  is  easily  understood  from  the 
followmg  table  (Sohultz) : — 


Anthracene 


I 

Anthraquinone 


r 


1 


(a-  &  ^-)  Anthracene  disulphonic  acids 


Disnli 


(a-  &  ^-)  Monosulphonio  add       (»-  k  ^)  Disnlphonio  adds 


I  I 

(x-  k  p-)  Disulphonic  acids 


^ 


«-  &  /S-  Hydroxy anthraquinones    Anthraflavic  acid    Isoanthratlavic  acid    Chrysazin     Anthrarufin 


T 

Alizarin 


t1avi( 


Flavopurpurin 


The  behaviour  of  the  anthraquinone  disul* 
pkhonio  adds  on  fusion  with  potash  is  exactly 
similar  to  that  of  the  monosuljmonic  add.  Just 
as  this  add  on  fusion  with  potash  is  first  con- 
verted into  monohydroxyanthraquinone  and 
then  b^  oxidation  into  dihydroxyanthraquinone 
(alizann),  so  the  anthraquinone  disulphonic 
adds  in  the  first  place  yield  the  corresponding 
dihydroxyanthraquinones,  which  then  bv  the 
farther  aiotion  of  the  potash  are  converted  into 
trihydzoxyanthraquinones. 
'    The  sulphonic  adds  of  anthraquinone  are 


Isopurpurin  Hydroxy-    Hydroxyan- 

(Anthrapurpurin)        chrysazm       tbrarufin 

important  intermediates  apart  from  their  con- 
version into  the  various  nydroxy  derivatives. 
The  sulphonic  group  may  be  displaced  by 
amino,  alkylamino-,  and  arylamino-  groups, 
usually  by  treatment  with  ammonia  or  an 
amine  at  a  high  temperature  and  occasionally 
in  the  presence  of  a  copper  compound,  sodium 
carbonate,  or  an  oxidising  agent.  Moreover,  the 
chloro-  derivatives  of  anthraquinone  are  most 
conveniently  prepared  by  the  action  of  sodium 
chlorate  on  a  solution  of  an-  anthraquinone 
sulphonic  acid  in  dilute  hydrochloric  add  at 


118 


ALIZARIN   AND  ALLIED  COLOURING   MATTERS. 


QO'^-IW.  For  example,  1  :  S-dichloroanthra- 
quinone  used  for  the  manufacture  of  Indanthrene 
Violet  R.N.  ia  obtained  in  this  way  from 
aathraquinone-1  : 5-diBulphonic  acid  (D.  R.  P. 
205105). 

Hydroxyanthnqiiiiioiies. 

L  MonohydrozyanthraquinonoB 

1- HydiDzyantiinuiuiDone.  Erythrozyanttira- 
quinone. 

This  Bubstanoe  is  formed  together  with  2- 
h)rdrozyanthraquinona  by  Btrongly  heating  a 
mixture  of  phenol  and  phtbalio  annydride  with 
sulphuric  acid 

,C0 


^•*^«<C0>^+C«H»^H 

Also  by  heating  I-bromanthraquinone  with 
potash  to  160**  or  by  acting  on  1-amidoanthra- 
quinone  with  nitrous  acid  in  concentrated 
sulphuric  acid  solution. 

The  most  satLsfactory  method  of  prepara- 
tion consists  in  heating  anthraquinone-1-sul- 
phonic  add  with  water  and  an  oxioe,  or  hydrox- 
ide of  an  alkaline  earth  metal  under  pressure. 

l-Hydroxyanthraqmnone  crystalJiBes  from 
alcohol  in  orange-red  needles  which  melt  'at 
190°.  When  fused  with  potash  it  gives  alizarin. 
The  substance  does  not  aye  morduited  fabrics. 

1-Aoetoxyanthraquinone,  prepared  by  boil- 
ing etythroxyanthraquinone  witn  acetic  anhy- 
dride and  sodium  acetate,  crystallises  in  yellow 
needles  from  alcohol  and  melts  at  176''-179*'. 

1-Methoxyanthraquinone  is  obtained  by 
the  action  of  boiling  methyl  alcoholic  potash  on 
1  -nitroanthraquinone. 

This  is  the  simplest  example  of  a  very  general 
reaction  in  the  anthraquinone  series.  The  sub- 
stance IB  yeUow,  microcrystaUine,  and  melts  at 
140*-145^ 

Literature, — ^Baeyer  and  Caxo  (Bar.  7,  960) ; 
Pechmann  (Ber.  12,  2128);  Romer  (Ber.  15, 
1793),  Liebermann  and  Hagen  (Ber.  15,  1804) ; 
Hoeohste  Farbwerke  (D.  R.  P.  07688). 

2-  Hydrozyanfhraqaliioiie. 

This  substiemce  is  obtained  synthetically  (to- 
gether with  eiythroxyanthraquinone)  by  heating 
a  mixture  of  phenol,  phthalic  anhydride,  and 
snlphurio  ada  The  mixed  hydroxyanthra- 
qumones  can  be  separated  bv  means  of  baryta 
water,  since  the  »arium  salt  of  1-  hydroxy- 
anthraquinone  is  insolubiB,  whilst  the  2-  hydroxy 
compound  is  eaaQy  soluble.  It  crystallises  from 
alcohol  in  yellow  plates  which  melt  at  323°  and 
readily  sublimes  at  a  higher  temperature. 

It  can  be  obtained  in  various  ways  from 
anthraquinone  or  its  derivatives. 

An  easy  preparation  consists  in  melting 
anthraquinone  sulphonic  acid  or  2-  bromanthra- 
quinone  with  potash. 

The  action  of  ammonium  persulphate  on  a 
solution  of  anthraquinone  in  concentrated  sul- 
phuric acid  containing  sulphur  trioxide  leads 
to  the  production  of  2-hy(uoxyanthraquinone, 
•i^rarin,  and  purpurin. 

'izarin  is  reduced  to  2-hydroxyanthra- 
le  by  the  action  of  alkaline  stannous 
e;  or  alizarin  amide,  obtained  by  the 


action  of  ammonia  on  alizarin,  yields  th**  sub- 
stance when  treated  with  ethyl  nitrite. 

A  very  curious  reaction  of  this  hydroxy- 
anthraquinone,  and  one  which  involves  migra- 
tion of  an  oxygen  atom,  is  its  conversion  to 
quinizarin  by  treatment  with  nitrous  acid  in 
sulphuric  acid  solution  and  in  the  presence  of 
borio  acid. 

Literature. — Qraebe  and  Liebermann  (An- 
nalen,  160,  141);  Baeyer  and  Garo  (Ber.  7, 
969);  Liebermann  and  Fisher  (Ber.  8,  976); 
Liebermann  (Annalen,  183, 208) ;  Wacker  (J.  Pr. 
Caiem.  [2]  54,  89);  Bayer  &  Co.  (D.  R.  P.  86830). 

DOiydrozyantlinqiilnoiies. 

Alizarin 

1 : 2-dihxdroxyanthraqiiinone 

Alizarin  occurs  in  madder  as  the  glnooside 
ruberythric  acid,  and  also  in  Chay  root  {Olden- 
landia  umhellaia)  and  some  species  of  rhubarb. 

It  is  obtained  from  its  glucoside  by  the  action 
of  dilute  acids  or  of  ferments. 

C„H„0,4  +  2H,0  -  CwH.O^  +  2C,H„0, 
Ruberythric  acid.  AJiiarin.         Giooose. 

It  may  be  prepared  artificialljc  by  many 
methods. 

Thus  alizarin  is  produced  by  fusing  dichlor- 
anthraquinone,  dibromanthraquinone,  anthra- 
quinone, mono-  or  di-sulphonio  acids  with 
potash.  RufigaUic  acid  yields  alizarin  when 
reduced  with  sodium  amalgam. 

On  the  other  hand,  anthraquinone  may  be 
directly  oxidised  to  alizarin  by  the  action  of 
ammonium  persulphate  in  concentrated  sulphuric 
acid  solution. 

Good  yields  of  alizarin  are  said  to  be  obtained 
by  heating  anthraquinone  with  sodium  chlorate 
and  a  mixture  of  sodium  and  potassium  hy- 
droxides in  aqueous  solution  at  200*.  This 
process  ia  used  for  the  manufacture  of  aUzarin, 
but  it  IB  not  dear  that  it  has  entirely  displaced 
the  older  process  shortly  to  be  described. 

Hystazarin  undergoes  isomeric  change  to 
alizarin  when  heated  with  concentrated  sulphuric 
add  to  200*  for  two  and  a  half  hours. 

Alizarin  may  be  synthesised  by  processes  not 
involving  the  intermediate  formation  of  anthra- 
quinone. 

Together  with  hystaxarin  it  is  produced  when 
a  mixture  of  catechol  and  phthabo  anhydride  is 
heated  with  sulphuric  add  at  200*. 

C.H,<^gg>0  +  C.H,(OH), 
Phthalio  anhydride.    Catechol. 

-  C.H,<^g>C.H,(OH).l :  2  +  H,0. 

Alisarin. 
A  method  somewhat  similar  in  prindple  is 
the  following : — 

Hemipinio  anhydride  condenses  with  benzene 
in  the  presence  of  aluminium  chloride,  yielding 
the  methyl  ether  of  dihydroxybenzoylbenzoio 
add.  This  latter  substance,  on  treatment  with 
hot  sulphuric  acid,  is  converted  into  alizarin 
methyl  ether,  which  ia  hydrolysed  by  aluminium 
chloride  to  alizarin.  The  following  formulas 
represent  this  series  of  reactions :— 


AUZARIN  AND   ALLIED   CX)LOU£INQ   MATTERS. 


119 


OMe 


\Aco/      ^ 

\A«)A/ 

AUxarin  methyl  ether. 

Lagodzuuki  has  converted  1 : 2-aQthraqai- 
none  into  alizarin  by  reducing  this  c^quinone  to 
I  :  2-dihydrozyanthraoene,  the  diaoetyl  deriva- 
tive of  which  yields  diaoetylalizarin  on  oxidation 
with  chromic  acid  in  acetic  acid  solution.  The 
diaoetate  is  then  h^drolyaed. 

Finally,  alizarin  is  frecjuently  formed  in 
relatively  small  proportion  m  the  reduction  of 
I-nitroanthraquinone,  for  example,  by  means  of 
■odium  sulphide. 

Masufacturb  ov  AuzABiir. 

1.  Anthraquiiwne  process, — Anthracene,  the 
basis  of  alisarin,  is  obtained  entirely  from  the 
coal-tar  oils  boiling  above  300*,  the  so-called 
« last  runnings'  m  the  tar  distiller.  These 
heavy  oils  are  redistilled  and  the  anthracene 
oik  collected  as  soon  as  the  distillate  on  cooling 
commences  to  solidify.  In  this  way  a  semi- 
solid greenish-looking  mass  is  obtained*  which, 
after  rouffhlv  freeing  from  excess  of  oil  by  treat- 
ment in  hydraulic  presses,  is  the  starting-point 
in  the  alizarin  factory.  This  crude  product  con- 
tains only  about  30-40  n.o.  anthracene,  the  re- 
mainder consisting  of  pnenanthrene,  naphthal- 
ene, carbazol,  and  small  quantities  of  other 
hydrocarbons. 

The  first  operation  necessary  in  the  manu- 
facture of  alizarin  is  that  of  purifying  the  crude 
anthracene  obtained  from  the  tir  distillers,  in 
order  to  obtain  a  product  fit  for  the  subsequent 
oxidation  to  anthnquinone. 

This  process  of  purification  varies  consider- 
ably in  different  countries,  but  the  followins 
method  may  be  given  as  having  been  used  with 
much  success. 

The  crude  anthracene  is  first  sround  between 
edge-runners,  and  then  thoroughly  a^^tated  with 
bouing  petroleum  spirit  in  utr^  iron  vessels 
fitted  with  stirrers  and  heated  with  steam. 

About  1600  to  1800  lb&  of  crude  anthracene 
and  300  gallons  of  petroleum  spirit  are  used  in 
one  operation,  the  amount  of  the  latter  varying 
slightly  according  to  the  quality  of  the  anthra- 
cene employed;  After  boiling  for  an  hour  or 
two,  the  product  is  allowed  to  cool,  filtered 
through  coarse  canvas,  and  the  anthracene  on  the 
filter  washed  with  a  little  clean  petroleum  spirit. 
The  pasty  mass  thus  obtained  is  next  treated 
with  steam  to  remove  the  excess  of  petroleum 
spirit,  and  then  sublimed.  The  sublimation  pro- 
cess is  best  carried  out  by  melting  the  anthra- 
cene in  an  iron  pot,  called  the  *  subliming  pot^' 
and  then  blowing  in  superheated  steam.    This 


carries  the  anthracene  vapour  forward  through 
a  long  pipe,  where  it  meets  a  sprav  of  water, 
which  serves  to  condense  both  it  and  the  steair. 
The  anthracene  is  thus  obtained  in  an  extremely 
finely  divided  state,  much  more  suitable  for 
oxidation  than  when  simply  ground  under  edge- 
runners  as  it  used  to  be.  Another  process  of 
purification  of  anthracene  consists  in  waahing 
in  a  neutral  solvent,  such  as  coal  tar  naphtha, 
with  concentrated  sulphuric  acid.  This  treat- 
ment removes  the  baaio  impurities,  and  the 
anthracene  is  further  jpnrified  b^  sublimation. 
The  next  step  consists  in  converting;  tiie  anthra- 
cene into  anthraquinone  by  oxidation  with 
bichromate  of  potash  (or  soda)  and  sulfuric 
acid — an  operation  which  is  usually  done  m  the 
following  way : — ^The  anthracene  is  placed  in 
lead-linM  tanks  with  about  twice  its  weight 
of  the  bichromate  (dissolved  in  water),  the 
requisite  amount  of  dilute  sulphuric  mM  is 
slowly  added,  and  the  mass  kept  well  boiled 
and  agitated  by  a  steam  jet  connected  witii  a 
Korting's  injector. 

The  whole  is  then  transferred  to  settling 
tanks,  the  crude  yellowish-brown  anthraquinone 
well  washed  by  decantation  until  free  from  green 
chrome  liquors,  well  drained,  and  freed  itom 
water  as  completely  as  possible  by  placing  it  in 
canvas  ba^s  and  exposing  it  to  great  pressure  in 
a  hydrauho  press.  The  amount  of  oxidiser  re- 
quired to  convert  the  crude  anthracene  into  an- 
tnraquinone  is  of  course  regulated  by  the  purity 
of  the  sample  employed,  pure  anthracene  re- 

Suiring  about  1*66  times  its  weight  of  potassium 
ichromate  to  convert  it  into  anthraquinone. 
Instead  of  potassium  bichromate,  the  sodium 
salt  is  now  very  often  used  on  account  of  its 
cheapness. 

The  anthraquinone  thus  obtained  is  still  very 
impure,  and  must  be  carefully  purified  before  it 
can  be  converted  into  sulphonic  acid.  In  puri- 
fying anthraquinone  two  methods  may  be 
employed : 

( 1 )  The  anthraquinone  is  sublimed,  and  then, 
if  necessary,  recrystallised  from  high  boiling 
coal-tar  naphtha. 

(2)  The  anthraquinone  is  treated  with  con- 
centrated sulphuric  acid. 

When  the  first  process  is  employed,  the  an- 
thraquinone is  melted  in  iron  pots  and  subjected 
to  the  action  of  super-heated  steam.  The  steam 
carries  the  vapour  of  the  anthraquinone  with  it, 
and  on  condensation  a  fine,  almost  impalpable 
powder  is  obtained,  which,  when  dried  and  re- 
crystallised  from  high-boilhig  coal-tar  naphtha, 
consists  of  nearly  pure  anthraquinone. 

In  this  country  this  process  hss  now  been 
almost  abandoned ;  method  (2)  having  entirely 
taken  its  place. 

The  working  of  this  method  is  based  on  the 
fact  that  crude  anthraquinone  when  treated  with 
sulphuric  add  at  100°  dissolves,  but  is  not  acted 
on.  The  impurities,  however,  become  converted 
into  sulphonic  acids,  which,  being  easily  soluble, 
can  be  removed  by  treating  the  productwithwater, 
when  nearly  pure  anthn^uinone  is  left  behind. 

In  carrying  out  tins  operation  a  mixture  of 
1  part  of  crude  anthraqumone  and  3  parts  of 
sulphuric  acid  is  plaoea  in  large  cireular  lead- 
lined  iron  pots,  and  heated  by  steam  for  twenty- 
four  hours,  the  whole  being  continuously  agitated 
by  a  stirrer. 


120 


ALIZARIN   AND   ALLIED   COLOURING   MATTERS. 


The  blaokiflh-looking  pioduot  is  then  run  into 
shallow  tanks,  and  exposed  to  the  action  of  damp 
air,  or  a  gentle  current  of  steam,  until  the  acid 
has  become  diluted.  In  a  short  time  anthraq ui- 
none  separates  out  as  a  light-brown  crystalline 
powder,  which,  after  washmg  by  dilute  soda  and 
by  decantation,  pressing,  and  thoroughly 
drying,  is  found  to  contam  about  95  p.a  of 
pure  substance. 

According  to  recent  patents  anthraquinone 
is  best  puxiSed  by  orystallisation  from  liquid 
sulphur  dioxide  or  from  anOine. 

The  following  account  of  the  manufacture 
of  anthraquinone  is  siven  by  Gain  (Manufacture 
of  Intermediate  Proaucts  for  Dyes,  p.  235)  as  an 
abstract  of  a  communication  oy  Urandmougin 
(Rev.  prod.  chinL  1917, 20, 20) :— *  The  oxidation 
is  effected  in  lead-lined  tubs  of  about  10-12 
cubic  metres*  capacity  (about  2600  gallons), 
fitted  with  lead-covered  agitetors  ana  direct 
steam  pipes,  aJso  of  lead.  160  kilos  of  sublimed 
anthracene  are  mixed  with  3000-4000  litres  of 
water,  and  the  mixture  is  heated  at  75®  ;  2000 
litres  of  a  solution  containing  300  kilos  of  sodium 
dichromate  and  600  kilos  of  sulphuric  acid 
(66°  Be.)  are  now  ran  in  slowly,  the  temperature 
being  gradually  raised  to  about  95^  The 
oxidation  requires  twelve  to  sixteen  hours,  and 
it  is  important  not  to  add  the  chromic  acid 
solution  too  quickly  or  to  work  in  a  too  con- 
centrated solution,  otherwise  much  frothing 
occurs. 

'Teste  are  made  b^  filtering  a  sample, 
washing,  and  subliming  it  over  a  naked  flame. 
With  a  little  practice  it  is  eas^  to  distinguish 
the  fine  needles  of  anthraqumone  from  the 
silvery  leaflete  of  anthracene.  The  absorption 
of  the  chromic  acid  can  also  be  ascertained  by 
titration  with  ferrous  sulphate.  When  the 
operation  is  finished,  the  oontento  of  the  tub 
are  run  into  an  egg  and  blown  through  a  filter 
press,  where  the  anthraquinone  is  thoroughly 
washed,  the  filtrate  being  collected  in  order  to 
recover  the  chromium.  The  yield  from  an 
anthracene  of  good  quality  is  about  110  parte 
of  anthraquinone  from  100  parte  of  anthracene. 
The  anthraquinone  so  obtained  is  purified  by 
sublimation  with  super-heated  steam ;  the  pan 
is  heated  by  super-heated  water  and  the  sublimed 
anthraquinone  condensed  by  means  of  a  water 
jet.' 

Other  processes  for  the  oxidation  of  anthra- 
cene have  been  suggested  but  have  not  yet 
displaced  the  chronuc  acid  method.  A  brief 
summary  of  these  methods  may  be  appended  : — 

(1)  Oxidation  of  anthracene  by  oxides  of 
nitn^en  and  air  or  oxysen  alone  or  in  the 
presence  of  various  catuyste  or  substances 
capable  of  absorbing  the  oxides  of  nitrogen. 
Occasionally  the  anthracene  is  mixed  with 
neutral  substances,  such  as  powdered  glass  or 
pumice.  In  one  process  anthracene  is  aSded  to 
a  solution  of  nitrogen  peroxide  in  nitrobenzene 
and  the  temperature  gradually  raised  to  100°. 
Anthraquinone  is  formed,  and  the  nitric  oxide 
is  recovered  and  converted  into  peroxide  for 
use  in  a  further  operation. 

(2)  Oxidation  of  anthracene  by  mtric  acid. 
This  is  usually  carried  out  in  nitrobenzene 
solution  and  sometimes  in  the  presence  of 
mercuric  nitrate. 

(3)  Oxidation  of  anthracene  bv  rnaai^  of 


sodium  nitrate  in  the  presence  of  magnesium 
chloride  between  125°  and  145°. 

(4)  Oxidation  of  anthracene  by  oxygen  in 
the  presence  of  aqueous  ammonia  and  copper 
oxide  at  170°.  NickeU  cobalt,  iron,  and  lead 
compounds  may  be  used  as  oatalysto  instead  of 
copper  oxide. 

(5).  Electrolytic  oxidation  of  anthracene  may 
be  carried  outm  a  chromic  acid  bath  or  in  20 
p.a  sulphuric  acid  solution  in  the  presence  of 
cerium  sulphate. 

(6)  Oxidation  of  anthracene  by  means  of 
ozonised  air.  In  this  case  the  hydrocarbon  is 
dissolved  in  sulphuric  acid. 

(7)  Oxidation  of  anthracene  by  means  of  a 
chlorate  in  aqueous  solution  in  presence  of  an 
iron  salt. 

The  following  patento  deal  with  the  oxida- 
tion of  snihracene:  Eng.  Pate.  6539,  1892; 
17635,  1901;  759,  1882;  19178,  1902;  8431, 
1887  ;  16312,  1909  ;  11472,  1910  ;  12056,  1914  ; 
5514,  1915.  Fr.  Pate.  220621,  149017,  328069, 
416735,  472216.  U.S.  Pats.  729502,  767136, 
1083051,  1103383,  1119546.  Ger.  Pata.  68474, 
137495,  21681,  109012,  152063,  215336,  207170, 
234289,  254710,  256623,  268049;  Anm.  U. 
61262,  292681. 

The  next  stage  in  the  manufacture  of  alizarin 
is  the  conversion  of  anthraquinone  into  ito 
sulphonic  acid. 

This  operation^  which  oonaisto  in  heating 
anthraquinone  with  fuming  sulphuric  acid,  is 
conducted  in  laige  iron  pote  capable  of  holding 
from  30  to  40  gulons.  The  amount  of  fuming 
sulphuric  acid  employed  depends  on  the  nature 
of  the  sulphonic  acid  required.  In  preparing 
the  monosulphonic  acid,  1  part  of  fuming  acid 
(contoined  40-60  p.c.  80,)  and  1  to  1^  parte  of 
anthraquinone  are  used. 

The  mixture  is  gradually  heated  by  means  of 
an  oil-bath  to  170*,  or  even  to  190*,  and  kept  at 
this  temperature  for  eight  or  ten  hours,  the 
stirrer  bemg  kept  constentiy  in  motion. 

The  product,  which  contains,  besides  anthra- 
quinonemonosulphonio  acid,  a  little  disulf^onic 
acid,  and  some  unacted-on  anthraquinone,  is 
diluted  with  water,  passed  through  a  filter-press 
to  remove  the  anthraquinone,  and  neutruised 
with  caustic  soda. 

In  a  short  time  the  whole  becomes  quite 
thick  owinx  to  the  separation  of  the  sparinglv 
soluble  soda  salt  ox  anthraquinonemonosul- 
phonic  acid,  the  easily  soluble  salte  of  the  di- 
sulphonic  acids  remaining  in  solution. 

The  crystalline  salt  is  collected  in  filter- 
presses,  washed  with  a  littie  very  dilute  sul- 
phuric acid,  and  thus  obtoined  practically  pure 
m  beautiful,  brilliant,  pearly  scales. 

In  preparing  the  disulphonlc  acids  of  anthra- 

auinone,  the  operation  is  similar  to  the  above, 
le  only  difference  being  that  more  fuming 
sulphuric  acid  is  used  and  the  sulphonation 
conducted  at  a  much  higher  temperature 
(about  260*). 

The  next  operation  consiste  in  the  conversion 
of  the  product  just  described,  and  called  '  soda 
salt,'  into  colouring  matter,  a  change  which  is 
accompUshed  by  heating;  it  strongly  with  oaustic 
soda  and  a  littie  potassium  chlorate. 

If  the  potassium  chlorate  is  not  added,  a 
considerable  loss  is  incurred  owing  to  the  re- 
ducing action  of  a  large  quantity  of  nascent 


ALIZARIN   AND   ALLIED   COLOURING   MATTERS. 


121 


bydrogeu,  always  formdd  daiing  the  foaion, 
which  oonTerts  the  soda  salt  partially  into  an- 
thzaquinone  and  hydroanthraquinone.  The 
fusion  is  oondncted  in  large  ^Toueht-iron  cylin* 
deis  fitted  with  stirrers  and  heated  with  hot  air. 
The  usnal  ohaige  is  700  lbs.  caustic  soda  (70  p.c) 
dissolved  in  water,  1300  lbs.  of  a  concentrated 
fiolation  ci  'soda  salt,'  and  13  to  15  p.a  of 
potaadom  chlorate,  the  amount  of  this  latter 
subatanoe  varying  slightly  with  the  nature  of 
the  salt  used,  the  monosulphonic  salt  requiring 
more  chlorate  than  the  disulphonic  salt. 

The  temperature  is  maintained  at  about  180* 
for  at  least  twenty-four  hours  and  often  much 
longer,  the  progress  of  the  decomposition  beius 
controlled  from  time  to  time  by  extracting  smaO 
quantities  of  the  melt  and  examining  them  in 
the  laboratory. 

The  product  thus  obtained  is  an  intense 
purple  fluid,  becoming  thick  on  cooling  and  con- 
taining the  colouring  matter  as  sodium  salt 
besides  sodium  sulphite  and  an  excess  of  caustic 
soda. 

To  separate  the  colour  the  melt  is  run  into 
laijTO  wooden  tanks,  diluted  with  water,  and 
boued  with  dilute  sulphuric  acid. 

This  causes  the  solution  to  become  orange  in 
colour  owing  to  the  precipitation  of  artificial 
aLsarin. 

After  being  allowed  to  settle,  the  supernatant 
liquor  is  run  off,  the  alizarin  forced  into  filter- 
presses  and  carefully  washed  until  free  tem 
acid  and  saline  matter.  The  colouring  matter 
is  ^en  made  up  to  a  definite  strength  (10  p.c.  or 
20  p.a  paste  as  required)  by  transferring  it  to 
larxfe  w(X)den  tuba  ntted  wilii  powerful  stirrers, 
ana  thoroughly  mixing  it  with  water. 

Pure  aluarin  thus  prepared  produces  a  blue 
shade  of  Turkey-red,  and  anthrapurpurin  (pro- 
duced by  fusing  sodium  anthraqumonedisulpho- 
oate  vn&k  caustic  soda)  a  red  shade,  so  that  by 
varying  the  amounts  of  these  two  constituents 
any  intermediate  shade  required  by  the  market 
can  be  obtained. 

The  foregoing  may  be  now  supplemented  by 
a  description  of  the  manufacture  of  alizarin 
which  is  given  by  UUmann.  The  sulnhonation 
of  anthraquinone  is  carried  out  in  aoia-resisting 
cast-iron  vessels  heated  by  super-heated  steam. 
The  pots  have  a  diameter  of  1166  mm.,  and 
height  of  1235  mm.,  and  are  surmounted  by 
covers  which  are  fitted  with  a  manhole,  stirrer, 
pipe  for  introducing  pressure,  plunging  tube  for 
thermometer,  and  a  contrivance  for  uio  automatic 
reffistration  of  temperature.  300  kilos  of 
sublimed  anthraquinone  and  200  kilos  of 
recovered  quioone  (the  portion  of  the  substance 
which  is  recovered  from  the  sulphonations)  are 
mixed  with  400  kilos  of  oleum  (20  p.c.  SO,)  and 
200  kilos  oleum  (60  p.c.  SO,),  and  the  mixture 
heated  at  145°  during  eight  hours.  This  pro- 
cedure mav  be  modified  by  introducing  hau  the 
amount  of  acid  and  heating  four  hours,  after 
which  the  remainder  is  intrcMuced  during  three 
hours  more,  and  in  one  or  two  portions.  Before 
the  reaction  mass  coola  it  is  forced  into  a  lead- 
lined  vat  containing  1*5-2  cbm.  water  with 
continuous  stirring.  Further  dilution  to  5 
cbm.  is  then  macfe,  and  the  mixture  heated 
by  the  introduction  of  steam.  Between  80  and 
120  kilos  of  anthraquinone  remain  unattacked 
and  are  recovered  by  filtration  through  a  piess. 


The  filtrate  is  mixed  with  85  kilos  caustic  soda 
an  amount  which  stiU  leaves  the  liquor  strongly 
acid,  bein£  only  about  three-eightha  of  that 
theoroticairy  required  for  neutnuisation.  The 
difficultly  soluble  *  silver  salt '  separatee,  and  is 
collected  in  a  presa.  The  filtrate  is  anbmitted 
to  vacuum  evaporation  to  22^-23°  B^.  (measured 
while  hot),  and  underneath  the  evaporator 
there  ia  a  vat  provided  with  atirring  apparatua, 
and  into  which  the  liquor  ia  allowed  to  run  for 
crystaUisation.  The  process  is  facilitated  by- 
providing  the  vat  with  a  double  jacket  for 
coohng.  The. 'silver  salt*  is  collected  in  a- 
filter  press  and  washed  with  brine,  in  wldch  it 
is  sparingly  soluble.  The  yield  of  dry  salt 
amounts  altogether  to  450-500  kiloa.  It 
requirea  no  further  purification  for  the  prepara- 
tion of  alizarin  of  bluiah  ahade.  The  mother- 
liquor  from  the  monoaulphonate  ia  neutralised 
with  lime,  and  the  gypaum  aeparated,  after 
which  the  calcium  aalta  aro  converted  into 
sodium  salts  by  means  of  aodium  carbonate  and 
the  Bolution  again  filtered  from  chalk.  Evapora- 
tion ^elda  the  2 : 6-  iaomeride,  and  finally  the 
2  :  7-,  but  it  is  perhaps  moro  usual  to  blow  the 
concentrated  mixture  directly  into  the  alkali 
fusion  apparatus.  The  fusion  of  silver  salt  with 
alkali  is  carried  out  in  a  series  of  horizontally 
placed  cylinders  provided  with  stirring  gear  and 
neated  by  means  of  super-heated  steam.  They 
have  to  be  capabk  of  resisting  a  pressure  of  12 
atmospheres.  The  capacity  ia  about  3550  litres, 
and  they  aro  about  2000  mm.  long  and  have  an 
inside  diameter  of  1400  mm.  The  following 
example  of  a  fusion  may  be  regarded  aa  t}mical ; 
1687  cbm.  of  caustic  soda  solution  (45^  Be'.) 
containing  1030  kilos  NaOH,  together  with  125 
kiloa  saltpetre,  aro  introduced  into  the  pot  and 
heated  to  about  125",  after  which  625  kilos  of 
moist  silver  salt  (66*4  p.c.),  corresponding  to  415 
kilos  of  the  dry  substimce,  aro  gradually  added. 
The  temperature  is  then  raised  to  180°,  and  the 
pressure  reaches  4-4*5  atmospheres.  After  36- 
48  hours  the  proceaa  ia  usually  complete.  This 
ia  confirmed  by  testing  a  sample  by  Boiling  with 
milk  of  lime,  filtering  from  the  sparingly  soluble 
calcium  alizarate  and  acidifying  the  filtrate, 
when  an  incomplete  operation  is  indicated  by 
the  separation  of  golden  flakes  of  oxyanthra- 
quinone.  The  melt  ia  diluted  down  to  6"  B^. 
in  large  lead-lined  tanks,  and  acidified  at  60*^ 
with  sulphuric  acid.  For  aUzarin  of  especially 
blue  shade  the  diluted  alkali  fusion  melt  la 
treated  in  boiling  solution  with  milk  of  lime 
until  a  drop  of  the  liquid  placed  on  filter-paper 
gives  a  dear  red  rim.  The  calcium  salt  is  then 
separated  and  decomposed  with  hydrochloric 
acid.  The  precipitated  alizarin  is  collected  in 
filter  preases  and  washed  until  the  filtrate  is^ 
free  from  acid.  The  press-cakes  are  analysed  for 
content  of  anhydrous  ash-free  alizarin,  and  on- 
the  baaiB  of  the  analysis  a  20  p.c.  paste  is  made 
in  a  special  mixer  made  of  pitch  pine.  The 
paste  has  a  thin  appearance,  but  if  it  should  be 
desired  thicker  it  auf&ces  to  add  O'5-l  p.c.  of 
salt.  The  thiokenina  of  the  paste  which  follows 
is  a  most  wngnlAr  ^enomenou,  and  resembles- 
in  appearance  the  suting  out  of  a  dye  although,, 
of  course,  the  suspended  solid  is  not  increased 
in  amount.  For  some  Eastern  markets  a  stilL 
thicker  paste  is  prepared  by  the  addition  of 
glycerin,  dextrin,  molasses,  or  ataroh.    Alizariik 


122 


AIJZARIN  AND   ALLIED  COLOURING   MATTERS. 


in  lumps  of  such  a  character  that  paste  may  be 
prepared  from  them  as  desired  is  made  by  mixing 
20  p.o.  paste  with  starch,  and  then  filtering  off 
and  very  carefuUv  and  gradually  drying  the 
mixture.  As  much  water  as  possible  is  removed 
by  pressure,  and  the  remainder  in  a  vacuum  at 
a  temperature  not  exceeding  60^.  During  the 
whole  process  of  alizarin  manufacture  it  is  most 
important  that  the  water  used  should  be  soft 
ana  fs  free  as  possible  from  iron.  Iron  in  ike 
water  will  absolutely  ruin  the  value  of  a  batch 
of  alizarin  from  the  point  of  view  of  purity  of 
shade.  '  If  through  some  defect  in.the  apparatus 
a  batch  should  become  contaminated  it  is 
useless  to  attempt  to  purify  the  dye  by  solution 
in  alkali,  and  reprecipitation  with  acid  in  view 
of  the  circumstance  that  the  objectionable  iron 
derivatives  (c/.  the  alizarinferrates  below)  are 
reprecipitateid  along  with  the  colouring  matter. 
The  b^t  treatment  is  with  hot  dilute  hydro- 
chloric acid  and  just  sufficient  potassium  chlorate 
to  produce  a  clear  yellow  colour. 

2.  DichhratUhracene  process, — In  manufac- 
turing alizarin  by  this  process,  which  appears 
to  have  been  abandoned  in  favour  of  that  already 
described,  it  is  necessary,  in  the  first  place, 
to  purify  the  anthracene  used  much  more 
thoroughly  than  is  the  case  in  the  anthra- 
quinone  process. 

For  this  purpose  the  anthracene,  after  washing 
with  petroleum  spirit  as  described  in  the  last 
process,  is  submitted  to  distillation  with  potash. 
This  removes  the  oarbazol  and  the  phenolic  sub- 
istances  present  in  the  crude  anthracene,  and  as, 
besides  this,  a  considerable  quantity  of  the  other 
impurities  are  charred  during  the  distillation, 
the  anthracene  resulting*  although  still  very  im- 
pure, is  found  to  be  greatly  improved  in  quality. 

In  carrying  out  this  operation  100  parts  of 
washed  anthracene,  30  piurts  of  potash,  and  6 
'parts  of  powdered  lime  are  thoroughly  ground 
•together  under  edge-runners,  the  mixture  intro- 
•duced  into  iron  retorts  and  distilled.  The  dis- 
tillate, which  consists  of  pale-yellow  cakes  con- 
taining about  50  p.c.  of  pure  anthracene,  is  now 
sufficiently  pure  for  conversion  into  dichlor- 
anthracene. 

In  chlorinating  anthracene,  leaden  chambers 
are  used,  technically  known  as  '  chlorine  ovens.* 
These  are  10  ft.  long,  4  ft.  6  in.  wide,  and  1  ft.  6  in. 
deep,  and  are  used  in  pairs,  connected  at  one 
end  in  order  that  any  chlorine  esoapinc  from  the 
first  oven  mav  come  in  contact  wiUi  a  fresh 
amount  of  antnraoene  and  thus  prevent  loss. 

400  lbs.  of  anthracene  are  put  into  each  oven, 
and  subjected  to  the  action  of  a  rapid  current  of 
chlorine  for  about  five  or  six  hours. 

The  anthracene  first  fuses  and  gets  dark  in 
colour,  hydrochloric  acid  being  evolved  in  abun- 
dance ;  but  after  a  time  this  fluid  product  begins 
to  deposit  crystals  and  soon  becomes  a  semi- 
solid mass.  In  order  to  purify  this  crude  pro- 
duct, it  is  first  freed  from  hydrochloric  acid  by 
washinff  with  dilute  caustic  soda,  and  then 
pressea  between  linen  cloths  in  a  hydraulic 
press,  by  which  means  a  considerable  quantity 
of  a  thick  dark  oily  product,  techniocJly  known 
«L6  '  chlorine  oils,'  is  got  rid  of. 

The  yellow  cakes  of  dichloranthracene  thus 
obtained  are  still  not  pure  enough  for  use ;  they 
must  next  be  sockked  in  coal-tar  naphtha  for 
«ome  time  and  pressed,  this  operation  being  re- 


peated  until  a  product  is  obtained  which  con- 
tains 84  p.a  of  pure  substance. 

The  next  process  consists  in  converting  the 
dichloranthracene  into  the  sulpho-  acicu  of 
anthraquinonc  by  treating  it  with  ordinary  con- 
centrated sulphuric  acid.  This  decomposition 
is  accomplished  in  iron  pots  capable  of  holding 
about  30  gallons  and  fitted  vvith  iron  covers  in 
which  there  is  an  opening  for  the  escape  of  the 
acid  vapours  formed  during  the  reaction. 

Those  pots  are  charged  with  350  lbs.  of  con- 
centrated sulphuric  acid  and  heated  to  140^-160* 
by  means  of  an  ordinary  fire,  the  dichloranthra- 
cene (70  lbs.)  being  shovelled  in  in  small  quanti- 
ties at  a  time.  Mter  aU  the  dichloranthracene 
has  been  added  and  the  frothing  due  to  the 
evolution  of  the  hydrochloric  and  sulphurous 
acids  produced  during  the  decomposition  has 
subsided,  the  temperature  is  gradually  raised 
to  260*  and  then  maintained  at  this  point  until 
a  sample  taken  out  on  a  glass  rod  and  diluted 
with  water  forms  a  nearly  clear  solution  devoid 
of  fluorescence. 

The  product  contains  now  the  mono-  and 
disulphonic  acids  of  anthraquinonc,  the  latter  of 
which  greatly  predominates. 

These  crude  sulphonic  acids  are  next  diluted 
with  water  in  a  large  wooden  tank  and  boiled 
with  slaked  lime  until  neutralised.  Tlie  neutral 
product  is  then  foreed  into  filter  presses  to  sepa- 
rate the  calcium  sulphate,  the  clear  filtrate  mixed 
with  the  washing  of  the  calcium  sulphate,  evapo- 
rated until  it  contains  about  15  p.o.  of  lime 
salts,  and  then  treated  with  sufficient  sodium 
carbonate  to  precipitate  all  the  lime  as  carbonate. 

The  solution  of  the  sodium  salts  of  the  sul- 
phonic acids  is  siphoned  from  the  precipitated 
calcium  carbonate,  concentrated  until  it  contains 
30  p.c.  of  soda  salts,  and  then  converted  into 
oolourins  matter  by  fusion  with  caustic  soda,  as 
described  in  the  last  process. 

3.  Direei  conversion  of  ar\ihfaquinoins  ifi$o 
alizarin. — ^In  the  preparation  of  anthraquinone- 
/3-sulphonic  acid  it  is  venr  difficult  to  avoid  the 
production  of  some  disulphonic  acid,  and  even 
if  the  alizarin  is  purified  as  described  below,  the 
shades  obtained  on  mordanted  fabrics  are  not 
quite  identical  with  those  given  bv  the  chemically 
pure  dyestuff.  The  Badische  Anilin  und  Soda 
Fabrik  claim  (D.  R.  P.  1 16526)  that  a  remarkably 
pure  alizarin  dyeing  bluish  shades  of  alizarin 
red  on  the  ususl  alumina  mordant  may  be  pre- 
pared from  anthraquinone  under  the  following 
conditions: — ^Anthraquinone  (100  parts)  is 
heated  with  a  solution  of  sodium  or  potassium 
hydroxide  (300  parts)  and  sodium  chlorate  (20- 
30  parts)  in  water  (ICK)  parts)  at  2(X)^  in  an  open 
vessel  or  autoclave  until  the  oxidising  agent  is 
expended.  The  product  is  dissolved  in  water 
and  air  blown  in  order  to  oxidise  anthranols, 
and  the  alizarin  is  then  precipitated  by  the 
addition  of  milk  of  lime.  The  precipitated  salt 
is  decomposed  by  hydrochloric  acid,  and  the 
alizarin  is  separated  from  accompanying  anthra- 
quinonc by  solution  in  dilute  aqueous  sodium 
hydroxide  and  acidification  of  the  filtered  solu- 
tion. Other  processes  have  been  suggested  in 
which  anthraquinone  is  heated  with  sodium  or 
potassium  hydroxides  in  the  presence  of  sodium 
sulphite,  with  or  witiiout  an  ozidising  agent 
saoli  as  sodium  chlorate. 

Pnrifleation  of   artifleial   allarlii.     Com- 


ALIZARIN  AND  ALLIED  COLOURING   MATTERS. 


123 


meroial  alizarin  contains  as  impurities  hydroxy- 
anthraquinone,  anthrapurpurin,  flavopurpurin, 
and  small  quantities  of  otl^r  colouring  matters. 

In  order  to  separate  the  alizarin  from  these, 
the  erode  commercial  product  is  dissolved  in 
dilute  caustic  soda,  and  the  solutiou  treated  with 
carbonic  acid  imt&  two-thiids  of  the  colouring 
matter  has  been  juecipitated  as  acid  sodium  salt. 
The  precipitate  is  collected,  washed  with  water, 
decomposed  with  hydrochloric  add,  the  crude 
alizarin  thus  obtained  dissolved  in  caustic  soda, 
and  the  treatment  with  carbonic  acid  repeated 
twice  more. 

The  purified  product  is  then  boiled  with 
bar^  water  to  remove  bydrozyanthraquinone 
and  anthraflavio  acid  (which  dissolve),  theDarium 
salt  of  alizarin  is  collected,  washed,  decomposed 
by  hydrochloric  add,  and  the  alizarin  dther 
sublimed  or  recrystallised  from  alcohol. 

Another  metnod  of  separation  is  based  on- 
the  temperatures  at  which  the  various  con- 
stituents d  the  mixture  sublime.  Alizarin  itself 
sublimes  at  110^,  flavopurpurin  and  anthra- 
purpurin  at  160^  and  170   respectively. 

XUwlll  crystallises  from  alcohol  in  red 
needles  or  prisms,  which  mdt  at  282^.  With 
care  alizarin  can  be  sublimed  in  magnificent 
deep-red  prisms,  which,  if  the  operation  be  per- 
formed on  a  la^  scale,  may  be  obtained  over 
an  inch  in  length. 

It  dissolves  in  alkalis  with  a  purple  colour, 
and  is  completdy  inedpitated  from  this  solution 
by  the  addition  oflime  or  baryta  in  the  form  of 
a  blue  predpitate  of  the  caldum  or  barium  salt. 
Ueatea  with  aoetio  anhydride  to  160®  alizarin 
forms  a  diaoetyl  compound  CttH.fi^GJEfi)mO^, 
which  crystallises  from  alcohol  in  long  vellow 
needles,  mdting  at  160®.  When  treated  with 
nitrous  acid,  alizarin  yields  anthraquinone. 
Nitric  add  acts  violently  on  alizarin  with  evolu- 
tion of  red  vapours  aiid  formation  of  phthalic 
and  oxalic  adds.  Distillation  with  zinc  reduces 
alizarin  to  anthracene. 

Alizarin  is  converted  into  purpurin  by 
means  of  sulphurio  add  at  225®.  In  Knecht 
and  HibberVs  tttanous  chloride  reduction 
method  for  the  estimation  of  reducible  substances 
it  is  found  that  one  molecule  of  alizarin  requires 
for  reduction  four  atoms  of  hydrogen.  On  the 
other  hand.  Alizarin  Orange  (see  below)  is 
reduced  to  aminoaUzarin  under  similar  condi- 
tions. 

When  fused  with  alkaline  hydroxides  at  a 
fairly  lugh  temperature,  protocatechuio  add  and 
benzoic  add  are  formed. 

Salts  of  alizarin.    Calcium  aiizanUe 

is  precipitated  by  addius  caldum  chloride  to  an 
ammAfi^f^^^^  solution  of  alizarin  as  a  purple 
mass.  Barium  alizaraU  BaCiJifi^MtO  is 
prepared,  like  the  caldum  salt,  by  mixing  an 
alkaline  solution  of  alizarin  with  barium  chloride. 
It  is  deep- violet  when  moist,  almost  black  when 
dry,  ana  very  sparingly  soluble  in  water.  Alum^ 
iiuum  alizaraU  {Cifi^0.)iAlfi^1)  is  obtained 
by  precipitating  an  ^WafinA  solution  of  alizarin 
with  alum  or  aluminium  hydroxide.  It  is  a  very 
fine  red  or  rose-red  precipitate.  Lead  alizaraU 
C|«H«04pb  is  obtainsd  by  muduff  an  alcoholic 
sdution  of  alizarin  with  an  alc<molic  solution 
of  sugar  of  lead. 


Potassium  hydrogen  alizarate  forms  a  com- 
pound with  aIizarin,laown-red  crystals 

C^H^O^K ;  O^HsO^, 
and  a  similar  ^'potassium  iiaUzarate  has  been 
described.    These  substances  are  analogous  to 
the  quadroxalates. 

Alizarin  can  readily  be  detected  by  means  of 
the  spectroscope,  as  it  gives  in  alkaline  solution 
two  uiarp  absorption  bands,  one  at  d  and  one 
near  o,  as  will  readily  be  seen  from  the  accom- 
panying  figure,   which   shows   the   absorption 


Aa     BC 


spectrum  of  a  solution  of  alizarin  in  alcoholic 
potash. 

Aliiarln  f errie  add  Fe(CuH.04),U,  yidds 
well-crystalUsed  sodium,  ammonium,  and  potas- 
sium salts.  The  latter  crystallises  with  8H,0, 
and  is  obtained  by  the  addition  of  alcoholic 
potasdum  hydroxioe  to  a  mixture  of  alcoholic 
solutions  of  alizarin  and  ferric  acetate. 

Liieraiure, — Anderson  (J.  1847-48,  749) 
Stenhouse  (J.  1864,  643) ;  Rochleder  (Ber.  3 
296);  Perkin  (Chem.  Soc.  Trans.  23,  141) 
Graebe  and  Liebermann  ( Annalen  SuppL  7,  300 
Ber.  3,  369) ;  Baeyer  and  Oaro  (Ber.  7,  972) , 
Liebermann  (Annalen,  183,  206);  Liebermann 
and  Dehnst  (Ber.  12,  1293) ;  Schunck  (Annalen, 
66,  187) ;  Wolff  and  Streoker  (Annalen,  76,  8) ; 
Lagodzinski  (Ber.  28,  1428) ;  Wldman  (Ber.  9, 
866) ;  Liebermann  and  Hohenemser  (Ber.  36, 
1779);  D.  R.  P.  116626;  Perkin  (Chem.  Soc. 
Trans.  76,  463) ;  Knecht  and  Hibbert  (J.  Soc. 
Dyers  and  Col.,  Dec.  1916);  Weinland  and 
Bmder  (Ber.  47,  977) ;  Hofmann,  Quoos  and 
Schneider  (Ber.  47,  1992);  HeUer  (Zeitsch. 
Angew.  Chem.  1906,  19,  669 ;  Ber.  41,  361) ; 
Tyrer  (Trans.  97,  1778) ;  Hlldebrand,  EUefson, 
andBeeve(J.  Amer.  Chem.  Soc.  1917,  39,  2301). 

Other  derivatives  of  aliiarin.  When  treated 
with  the  ordinary  re-agents,  such  as  bromine, 
nitric  acid,  &c.,  alizarin  forms  a  variety  of 
valuable  substitution  products,  some  of  which 
are  used  to  a  considerable  extent  as  dyeing 
agents.  The  most  important  of  these  are  the 
following : — 

Alizarin  a-methyl  ether 

OMe 
OH 


\oo/v^ 

may  be  synthesised  by  the  action  of  diazo- 
methane  on  an  ethereal  solution  of  monoacetyl- 
alizarin.  Owing  to  the  fact  that  monacetyl- 
alizarin  is  really  a  mixture  of  the  two  posmole 
isomerides,  the  process  results  in  a  mixture  of 
the  two  isomeric  methyl  ethers.  Addition  of 
alcoholic  potasdum  hydroxide  to  the  mixture 
precipitates  the  i3-ether  as  potassium  salt,  the 
a-methyl  ether  remaining  ut  the  solution.  The 
substfluice  crystallises  From  aqueous  methyl 
alcohol  in  slender  orange-yellow  needles  mdting 
at  178°-179*',  and  identical  with  a  constituent 
of  chay  root  {q.v.)  (Oesch  and  Perkin,  Proc 
Chem.  Soc.  1914,  30).  The  methoxy  groups  in 
aromatic  compounds  (except  the  nitrophenol 
ethers)  are  almost  always  resistant  to  alkaline 
hydrolysis,  but  this  substance  may  be  hydrolyted. 


ALIZARIN  ANT)  ALUED  COLOrETNG  MATTERS. 


to  aluaria  b;  the  proIoDged  sotiou  of  boiling 
squeona  baryta.     AcetyUUzaiin  o-methyl  ether 
occun  in  yeUoir  needlea,  molting  at  212  . 
Alluda-0-matli>I  Mat 

\/\co/vy 

The  lynthesis  of  thi«  inbstanM  from  hemipuiio 
acid  has  already  been  deeciibed. 

It  can  also  be  produood  by  treating  the 
moDopotiwinm  aaJt  of  alizaxm  with  inetbyl 
iodide  or  mediyl  sulphate. 

The  anbatsnoe  crysballisea  from  aloohol,  and 
baa  the  melting-point  224''-22e°. 

The  dimetiiyl  ether  is  not  obtained  by  aoling 
on  the  potaaaiuni  salt  of  the  monomethyl  ether 
with  methyl  iodide. 

The  mMtaiiae  can,  however,  be  obtained  bv 

ating^B  latter  tiy  means  of  methyl  sulphate 
and  sodium  hydroude  in  the  umu  manner. 
On  oxidation  of  the  raaulting  piodnot  with 
•odium  ohiomate  and  acetic  acid  alizarin 
dimethyl  ether  ii  obtained  in  golden  yellow 
needlea.  lb  lb  identical  with  a  product  obtained 
from  2.hydrozyanthTaqiiinone  by  Bucoenivo 
methylation,  nitration,  and  treatmeDt  with 
methyl  alcoboUc  eodium  methozide. 

Oeaab  and  Perkin  (I.e.)  have  alao  obtained 
the  subatance  by  the  methyUtioD  ot  alizarin 
a- methyl  ether  wit^  methyl  sulphate  and 
potawium  hydroxide. 

Ailwfa  dletbyl  etiur 


C^,<™>C.HBKgg 


Thi«  derivative  oao  be  prepared  by  hTTitinc 
alizarin  with  bromine  and  carboo  disnlphide  to 
ISO'-IW  for  four  or  five  hour*. 

It  )■  lietter  prepared,  however,  by  aul- 
phooaling  alizarin  with  fuming  snlphuric  aoid, 
and  Bubaequently  treating  tM  solution  with 
titomine. 

It  oryatalliMa  from  glaoiol  aoetio  aoid  in 
oiange-oolonied  nwdtoi^  wliiah,  when  heated, 
first  melt  t«  an  onnse-eolaaied  liquid  aod  then 
rablime  in  otange-red  needles. 

As  a  dyeing  agent,  mouobromalizarin  retains 

all  the  propertiee  ot  combining  with  mordants 

pOMSSSed  by  alizarin,  and  tlte  ooloors  produced 

appear  to  be  equally  fast.    The  shade  ot  oolour 

the  same,  the  reds 

irpke  leea  blue  than 

m.  Soo.  Trans.  27, 

dnuyantliraqniDOiM 
is  obtained  by  the 
;otion  of  aIizarin-3- 
nay  or  may  not  be 
ribed  bromoalizarin. 
I,  melting  at  260°- 
'  diacetyl  derivative, 
le   solution    ot    the 


substance  in  dilute  sodium  hydioiide  ii  blue- 

3-ChIoro-l '.  2-dlhydroxyMitlmt4uliMDe  i> 
similarly  prepared  and  mute  at  2T0°-271*.  Od 
benzoyution  in  pyridine  solntion  a  dAaaof/l 
derivaUve,  melting  at  184",  ia  obtained.  On 
oxidation  by  means  of  tulpburic  acid  it  vields 
3-Moro-l  :  2  :  i-lriki/drcayanUiraquimnu  (chloro- 
pnrpoiin),  melting  at  212°^244°,  and  on  nilia- 
tion  in  acetio  acid  solution  Z-Moro-i-nilT^l  :  2- 
dihydroxyarUhra^iiuMt  is  the  product.  The 
latter  occurs  in  oraiwe-jrellow  needlea,  whiob 
deoompoM  at  above  1^0°.  The  nitconl  may 
be  displaced  by  *niHtwi  on  heating  t^  eubetance 
with  aniline,  and  the  prodoot  nijntsllirma  in 
nearly  black  needlea  or  pUtei  maltmi  at  223°- 
224°  (Heller  and  Skraup,  Bar.  M,  2T(W). 

^^j^ . 


C'H*<CO>CiH^OH  (2) 

This  eubstaooe  is  obtained  by  treating  diaoetyl 
or  dibenzoyl  alizarin  wiUi  nibio  add. 

It  ia  manufactured  by  dissolving  alixaiin  in 
fuming  aulphurio  aoid  and  after  oooling  to 
—Bt'  to  —10°,  traating  with  the  oaloluated 
quantity  of  nitric  acid  dissolved  in  ndphnrio 

a-Nitroalizarin  crystalliaes  from  alcohol  or 
glacial  acetic  acid  in  golden-yellow  needleB, 
melting  at  194°-196°.  It  dissolves  in  caustic 
alkali  with  a  blue-violet  colour,  but  if  only  a 
minute  quantity  ot  alkali  ia  employed  the  solu- 
tion is  di  a  fine  oilmson  oolour.  The  alkaline 
solution  gives  two  absorption  bands  """"i"  to 
alizarin.  Nitioalizann  is  easily  reduced  in 
alkaline  solution  with  sodium  amalgam  or 
ammonium  eulpiiide  uid  amidoalizuin  ia  Uie 
prodnot. 

On  warming  with  sulphuric  acki  1 : 2 ;  3 :  <• 


no  /OH  (1) 

^^  ^HH,  (4) 

This  valuable  dye-stnft  is  obtained  by  the 
redaction  of  a-nitroalizarin.  It  crystallisee 
from  aloohol  in  small  needles  of  »  neariy  black 
oolour,  but  posseaaing  a  slight  greenish  metAUio 
reflection. 

Ita  aloohoUo  solution  gives  two  abeoiptioa 
bands ;  the  fint  is  a  little  beyond  d  and  the 
second  near  c.    There  ie  also  a  taint  line  dose 

tOF. 

An  eiotes  of  acetic  anhydride  at  the  tioiling- 
point  converts  a-aminoajizarin  into  a  efia';rlvl 
dtrittUivr,  which  oiystalliBea  in  red-brown  leaflets 
melting  at  240°,  whilst  it  appears  that  the  mode- 
rated action  of  the  reagent  produces  an  iaomerie 
diaoetate  cryBtaJlising  m  lustrous  yellow  needles. 
The  moiKtt«io!il  derivative  is  obtained  by  heating 
a  suspension  of  the  substance  in  nitiot>enzpne 
with  beiuovl  ohloride.  It  occurs  in  brown 
oeedlee,  melting  at  310°.  Further  ocUon  of 
benzoyl  chloride  produoes  the  dibeiKMiil  derita- 
tivt — Ught  brown  needles,  melting  at  256°. 
B-Aminoalizarin  yields  a  sulphomo  add  on 
treatment  with  fuming  aoid,  uid  this  may  be 
chuiged  into  purpurin  sulphonla  aoid  by  the 
action  of  nitrous  acid.     The  '^■"inilTiin  deriva- 


ALIZARIN  AND  OTHER  COLOURING  MATTERS. 


125 


tiTM  obteined  from  a-aminoaUzarin  are  rela- 
tively stable,  and  on  strongly  heating  pmpurin 
IB  obtained  as  a  sublimate.  Al]zann-a-<uaKo- 
cbloride  does  not  couple  with  known  inter- 
mediates with  formation  of  azo-  oomponnds. 

Dytlng  Properties  of  a-Nitro-  ana  a-Amino- 
■HfliTllli  llese  colouring  matters  possess  the 
power  of  dyeing  ordinair  madder  mordants* 
a-Nitroalizarin  gives  witn  alumina  mordants 
very  dear  oranga-red  colours,  not  unlike  some 
of  the  ooloun  produced  with  aurin,  and  with 
iron  mordants  reddish-purple  colours.  Amino- 
alizarin  gives  with  alumina  mordants  purple 
colours,  and  with  iron  a  bluish  or  steel-lue 
colour. 

It  is  used  for  wool-dyeing  and  calico-printing. 

AHxulli  Maroon  is  a  mixture  of^  amino- 
alizarins  and  puipurins  obtained  bv  the  reduc- 
tion of  the  product  of  nitration  of  commercial 
alizarin  in  suphuric  add  solution.  On  alumina 
mordants  it  produces  a  garnet  red,  maroon  on 
chrome. 

Literature. — ^Perkin  (Chem.  See.  Trans.  30, 
578);  Brasch  (Ber.  24,  1610);  Sohunck  and 
Romer  (Ber.  12,  587);  D.  R.  PP.  66811,  74431, 
74598;  Schultz  and  Erber  (J.  pr.  Chem.  74, 
275). 

/s-mtioalicarln.  ABniln  Orange 

C.H,<:gg>C,H^H  (2) 
^^  ^NO,  (3) 

iS-Nitroalizarin  s  prepared  by  the  action  of 
nitric  add  on  alizarin  and  also  by  boiling  dinitro- 
2-hydroxyanthraquinone  with  caustic  soda  of 
20p.c. 

It  is  manufactured  in  large  quantities  by  the 
action  of  nitric  acid  on  a£zarin  dissolved  in 
sulphuric  acid  containing  boric  add.  The  in- 
fluence of  the  boric  add  on  the  podtion  attacked 
by  the  nitric  add  is  probably  due  to  tiie  forma- 
tion of  a  boric  ester  of  alizarin. 

The  crude  /3-nitroalizarin  is  purified  by 
erystaUisation  from  glacial  acetic  acid. 

/3-Nitroalizarin  crystalliaes  in  orange-ydlow 
needles  which  mdt  with  decompodtion  at  244®. 
When  carefully  heated  it  sublimes,  with  a  good 
deal  of  decomposition,  in  yellow  needles.  jDis- 
solved  in  alkalis  it  forms  a  purple  solution ;  the 
sodium  salt  is  insoluble  in  an  excess  of  caustic 
soda.  The  cakium  salt  is  an  insoluble  violet- 
red  predpitate,  which  is  not  decomposed  by 
carbonic  add  (distinction  from  alizarin).  Treated 
with  glycerol  and  sulphuric  add,  ^nitroalizarin 
is  converted  into  alizarin  blue. 

The  diacetate  of  iS-nitroalizarin  crystallises 
in  yellow  needles  mdting  at  218*^. 

/3-Nitroalizarin  is  prepared  on  the  large  scale, 
and  comeq  into  the  ma»et  under  the  name  of 
'  Alizarin  orange.*  In  dyeing  it  is  applied  to 
the  various  fibres  in  the  same  way  as  alizarin ; 
but  although  it  yields  fast  colours,  it  has  as  yet 
found  only  comparativdy  limited  employment. 
Apj^ied  to  wool,  it  ffives  the  following  shaaes  : — 

With  an  alumimum  mordant  it  yields  a  very 
good  orange ;  with  stannous  ohloriclo  mordant,  a 
reddish  or  yeUowish  orange,  according  to  the 
amount  of  mordant  used ;  with  copper  sulphate 
mordant,  a  good  reddish-brown  is  obtamed ; 
with  ferrous  sulphate,  a  purplish-brown ;  and 
with  bichromate  of  potash,  a  dull  brownish-red. 
The  dye  may  also  oe  applied  to  unmordanted 


wool  in  a  bath  containing   acetic    or  oxalic 
adds. 

L»<ertx<Kre.— Rosenstiehl  (BuU.  Soc.  ohim.  26, 
63) ;  Sohunck  and  Romer  (Ber.  12,  584) ;  Simon 
(Ber.  15,  692) ;  Bayer  ft  Go.  D.  R.  P.  74562 ; 
Barnes  (J.  Soc.  Dym  ft  Col.  15,  [1]  11). 

iS-Aminoalizarm  is  chan£[ed  bv  benzoyl 
chloride  into  a  dibenzoyl  denfxtttve,jmow  needles 
melting  at  252®,  and  this  may  be  hydrolysed 
by  sulphuric  add  to  a  moncbenzoate  mdting  at 
275®.  In  contradistinction  from  the  corre- 
sponding o-derivative,  alizarin-/9-diazochloride 
couples  with  R-salt  in  alkaline  solution,  but 
the  product  has  feeble  tinctorial  power. 

Alliarin  Imlde*  This  derivative  of  alizarin 
is  obtained  by  heating  the  substance  with 
ammonia  under  pressure  (Bayer),  and  also  by 
reducing  freshly  precipitated  alizarin  in  ammo- 
niacal  suspension  witn  zinc  dust  followed  W 
air  oxidation  of  the  resulting  solution.  Accord.- 
ing  to  Prud'homme,  alizarin  and  other  hydroxy- 
anthraquinones  may  be  converted  into  con- 
densation products  with  ammonia  by  heatins 
in  fflyoGrol  with  ammonium  carbonate.  ScholJ 
ana  Partheg  prepare  the  substance  by  heating 
alizarin  wiSi  aqueous  ammonia  at  140®.  It 
may  be  crystallised  from  pyridine  and  decom- 
poses with  evolution  of  ammonia  at  250®.  It 
IS  T^arded  as  l'hydroxy'2'aminoanUiraquinone 
imide. 

Z^ieroture.— Prud*homme  (Bull.  Soc.  chim. 
[iii.]  35,  71 ;  ibid.  666) ;  SchoU  and  Partheg 
(Ber.  39, 1201). 

LeaeoaUzarln,  1 : 2-Daiydroxyantliranol.  This 
substance  is  easily  prepared  by  wanning  alizarin 
with  a  dilute  alkalme  solution  of  sodium  hydro- 
sulphite.  It  crystallises  from  acetic  acid  in 
brown  leafleto  mdting  at  160®,  and  is  easily 
reoxidised  into  alizarin  (Qrandmougin,  Rev. 
Gen.  Nat.  Col.  21,  44). 

Alizarin  Red  8,  Alizarin  Powder  W  (By), 
Alizarin  Red  WS  (M.  L.  B.) 

^^  /OR  (1) 

OA<g8>O.H<OH^2) 

This  dyestuff  is  the  sodium  salt  of  the  mono- 
sulphonic  add  of  alizarin.  It  is  easily  prepared 
bv  the  action  of  concentrated  sulphuric  acid  on 
auzarin. 

It  yields  brilliant  scarlet  red  shades  with  an 
aluminium  mordant,  bordeaux  red  with  chro- 
mium. 

Like  many  alizarin  derivatives,  this  substance 
is  an  indicator.  It  is  more  senmtive  than 
methyl  orange,  the   colour   change   occurring 

+  + 

between  PH=3-7  (ydlow)  and  PH«=4-2  (pink). 

Literature, — Graebe  and  Liebermann  (An- 
nalen,  160,  144) ;  Walpole  (J.  Soc.  Chem.  Ind. 
1915,  153). 

1 : 2-Dl]iydroxyanthraqiiinone-3 : 5-disiilphonic 
add  is  obtained,  together  with  quinizarin-a- 
sulphonio  acid,  when  anthraquinone-1 -sulphonic 
acid  or  its  potassium  salt  is  heated  with  tuming 
sulphuric  acid  (40  p.c.  SO,)  and  boric  acid  at 
130®- 135®.  The  alizarin  derivative  is  separated 
by  teking  advantage  of  its  more  sparing 
solubility.  On  heating  with  70  p.c.  sulphuric 
acid  the  disulphonic  acid  is  changed  into  an 
isomeride  of  Alizarin  Red  S,  namely  1  : 2- 
dihydroxyantbraquinone-5-Bulphonic  acid. 


ALIZARIN  AND  OTHER  COLOURING  MATTERa 


Tbu  important  colouring  matter,  discovered 
by  Pnid'homme,  is  obtained  by  treating  fi^nitro- 
alizarin  with  elf  cerol  and  tolpbnric  acid  or  by 
treating  S-amino  alizarin  wlt^  glycerol,  nftro- 
iieOEcne,  and  sulphuric  acid.  Ita  chemical 
consUtution  WM  first  denjonrtnited  by  Graebe, 
who  showed  that  this  snbitanoe  wu  related  to 
siiiarin  in  preoitely  the  same  way  as  qninoline 
is  to  benzene,  i.t.  that  alizarin  blue  is  a  quinoline 
of  alizarin. 

Preparation. — 1  part  ot  fl-nitroalizarin,  6 
parte  snlphurio  acid,  and  1}  glyosrol  (ot  sp.gr. 
I  '262}  are  mixed  and  gently  heated. 

At  107°  the  reaction  commenoea  and  soon 
booomeB  very  violent,  the  temperature  rising  to 
200°.  After  the  frathine  has  subsided,  the  mass 
it  poared  into  water,  the  product  well  boiled, 
filtered,  and  the  residue  extracted  three  or  four 
times  with  very  dilute  Eolphuric  acid.  The 
rombined  eztracte  on  cooling  deposit  the  erode 
alizarin  blue  mlphate  in  brown  cryttals.  Those 
are  collected,  washed  with  water  till  neutral, 
mized  with  water,  and  boraz  added  until  the 
solation  becomea  brownish -violet.  The  precipi- 
tate thus  formed  is  filtered  off,  washed  wuh 
water,  and  decomposed  with  a  dilute  acid,  the 
crude  alizarin  blue  thus  obtained  being  putiSed 
by  recrystallisation  from  benzene  or  glaci^ 
acetic  aoid. 

A  more  recent  method  of  preparation,  also 
due  to  Pnid'homme,  consist*  in  heating  formyl- 
^-amiooalizarin  inth  glycerol  and  luli^nric 
acid  at  lOr. 

Alizarin  blue  oryEt^Uaea  from  betuene  in 
brownish -violet  nee<U«e  which  melt  at  270°,  and 
at  a  higher  temperktnre  give  oS  oranee-red 
vapoms  which  condense  in  the  form  of  blae 


benzene.     It  dissolve*  in  ammonia,  potash,  or 
soda,  forming  blue  solutions  which  become  green 
when  mized  with  an  ezceas  ot  alkali- 
Alizarin  blue  combines  with  both  bases  and 

lie  barium  salt  BaC„H:NO,BaO+JH,0  is 

a  greenish-blue  precipitate.     The  following  salts 

of  alizarin  blue  with  acids  have  been  prepared : — 

C,,H^0„HC1  is  a  red  cryst*llinB precipitate 

formed  by  passing  dry  hydrochlorio  acid  gas 

•ion  of  aliearin  blue  in  boihng 

1  treated  with  water  it  is  com- 

>sed  into  its 


.   Theai 


0,  cryatollisee  in  blue  f>lates. 
I  also  combines  with  picric  acid 
Mund  C,;H^O,C.H,(NO,),0, 
M  from  benzene  in  long  oranse- 
Ing  at  245".  This  compound  is 
■inposed  by  water.  One  ot  the 
cnmponnds  of  alizarin  blue  is 
iphit*  compoand 
^,NO,-2NaHSO, 


This  product  is  manutactnred  on  a  lane  Male 
and  sold  onder  Uie  name  of  '  Alizarin  Bins  S.' 
It  dissolves  readily  in  water,  with  a  brownisb-red 
oobnr.  Alizarin  blue  ia  met  with  in  commerce 
fn  two  forms,  viz.  as  a  paste  oontuning  about 
10  p.c-  of  <^  substance,  and  as  a  powder. 
The  fomier  is  nearly  insolable  in  water,  while 
the  latter,  which  ia  the  bisnlphite  compound 
(described  above),  dissolvea  raodily.  This 
soluble  kind  Is  now  almost  entirely  used  in 
dyeing.  In  dyeing  cotton  with  alizarin  bine  a 
chromium  mordant  is  used,  but  in  the  case 
of  wool,  bichromate  of  potaah  gives  the  best 

Alizarin  bine  with  an  alumina  or  iron  mcrdoiit 
is  also  used  for  dyeing  silk. 

Alizarin  blue  is  used  largely  *»  a  substitirte 
for  indigo  in  calico-pTJnting  woib.  It  is  mm  of 
the  most  stable  ooloariiu  matters,  and  ia  even 
said  to  be  faster  than  inmgo  IImU. 

Lilentttirt. — Pnid'homme  (Boll,  Soo.  chim. 
2S,  Q2) ;  Oraebe  (Annalen,  20l,  333) ;  Auerbach 
(Chem.  8oc-  Trans.  ZB,  800) ;  Pmd'homme  and 
Rabaut  (Bull.  Soo.  Ind.  Mulhouae,  1S93,  223). 

AllKHtD  Or«an  8  (H) 


oca 


This  dyestufl  is  prepared  from  a 
by  trsatmeut  with  glycerol,  nitrobenzene,  and 
sulphuric  acid,  and  it  may  also  be  produced 
from  fonnyl-a-aminoalizarin   by  the  action  ot 

Slyoerol  and  sulphoric  acid  at  100°.  Ite  pro- 
uction  and  properties  resemble  those  of  alizarin 
blue-  It  is  employed  in  printing,  and  is  used 
with  a  nickel  magnesia  mordant. 

PurpurouDthln.     I  :  S-Dihydroxyanthraqni- 


PurpuroxaDthin  ezista  in  small  qoantJtiM  in 
madder.  It  can  beprepared  by  heating  pDrpnrin 
CuH,(OH),0,  with  iodide  of  phoapboros  and 
water,  or  more  readily  by  boiling  purpnrin  with 
caastic  soda  and  cbltnide  of  tin. 

Preparation.  —  Purpurin  is  dissolved  in  a 
boiling  solution  of  caustic  soda  (10  p.o.),  and 
chloride  of  tin  added  until  the  solution  Ions  its 
deep-red  tint  and  becomes  of  a  yellow  oolonr. 
Hydrochloric  acid  is  then  added,  the  precipitate 
washed  with  strong  hydrochlorio  acid,  dissolved 
in  baryta  water,  reprecipitated  with  bydroohloric 
acid  and  crystaUiaed  from  alcohol. 

Furpurin  is  also  readily  reduced  by  meana 
of  an  alkaline  solution  of  sodium  hydrosulphite. 

Purpuroianthin  crystallises  in  reddish-yellow 
needlee  which  melt  at  2e2''-2e3°.  It  dissolves  in 
alkalis  with  a  reddish  colour.  If  the  solution 
in  caustic  potash  be  boiled  in  the  air,  it  absorbs 
oxygen,  the  purpuroianthin  being  reconverted 
into  purpnrin. 

It  is  not  a  mordant  dyestuR. 

Literature. — Schutxenberger  and  SchiSert 
(Bull.  8oc.  chim.  4.  12) ;  Liebermann  (Annalen, 
183,  213) ;  Schnnck  and  Romer  (Ber.  10,  178). 


ALIZARIN   AND   ALLIED   OOLOURINO   MATTER& 


127 


Qldalatflll.    1 : 4-Dihydrox7»nthraqiunone 
CtH4<^Q>C«H,<Q2  (4) 

IS  obtained  by  heatixur  a  mixture  of  qninol  or 
jHshlorphenol  and  phthalio  anhydride  Tnth 
golphorio  acid. 

C.H.<gg>0+C;i.<OH  (1) 


=CA<C0>C.H.<0H  lil+H*^ 


(4) 

Together  with  alizarin  and  purporin,  it  is 
obtained  by  the  action  of  ammonium  persulphate 
on  anthraquinone  in  snlphurio  acid  solution; 
also  on  heating  anthraquinone  in  sulphuric  add, 
containing  bono  acid,  with  nitrous  fumes. 

PrepanUion, — ^Equal  parts  of  p-chlorphenol 
and  phthalio  anhydride  are  heated  to  2(Xr*-210^ 
for  some  hours,  with  ten  times  as  much  sul- 
phuric acid  as  ohlorphenol  used.  The  product 
is  poured  into  two  or  three  times  its  Yolume  of 
water,  and  after  standing  for  twenty-four  hours, 
the  precipitate  is  filtered  off,  washed  and 
pressed. 

The  crude  product  is  then  boiled  with  water 
to  free  it  from  phthalio  acid,  dissolved  in  caustic 
soda,  precipitated  with  hydrochloric  acid  and 
reciystalliaed  from  alcohol.  In  order  to  remove 
a  small  quantity  of  purpurin,  which  is  nearly 
always  present,  the  crude  quinizarin  is  then 
washed  with  cold  dilute  caustic  soda  as  long  as 
the  solution  is  coloured  red,  and  the  residue 
reciystallised  from  toluene. 

Quinizarin  is  also  obtained  by  heating  either 
the  1-  or  the  2-hydrozyanthraquinones  with 
nitrites  and  boric  acid  in  sulphuric  acid  solution 
at  lB0''-200''.  The  formation  of  quinizarin 
from  2-hydrozyanthraquinone  is  certiEunly  re- 
markable, but  the  expected  product,  namely 
purpuiin,  is  formed  in  traces  only.  A  process 
of  theoretical  interest  is  that  of  Dienel  (Ber. 
1906,  39,  926),  who  converts  a-anthrol  by  means 
of  a  hot  aqueous  alcoholic  solution  of  sodium 
nitrite  and  zinc  chloride  into  two  isomeric 
nitroao-derivatives  which  may  be  reduced  to 
amino  compounds  and  oxidised  to  1 : 2-  and 
1  : 4-anthraauinones  respectively.  The  latter 
ciystallises  m>m  alcohol  in  long  yellow  needles 
which  melt  at  206°  (c/.,  however,  Haslinger,  Ber. 
39,  3537,  who  gives  190'')  and  by  successive 
redaction,  acetylation,  oxidation,  and  hydrolysis 
may  be  changed  to  quinizarin. 

Quinizarin  crystallises  from  alcohol  in  red 
needles  which  melt  at  192''-193'*,  and  sublime  at 
a  hij^h  temperature  with  partial  decomposition. 
It  dissolves  readily  in  benzene.  The  solutions  in 
ether  and  sulphuric  acid  are  characterised  bv  a 
beautiful  greenish-yellow  fluorescence.  Qumi- 
zarin  dissolves  in  baryta,  forming  a  blue  solution 
from  which  it  is  rejprecipitated  on  passing  car- 
bonic acid  (distinction  from  alizarin). 

The  tinctorial  effects  produced  by  quinizarin 
on  fabrics  mordanted  with  iron,  chromium,  or 
aluminium  are  about  one -tenth  of  those  pro- 
duced by  an  equal  amount  of  alizarin. 

When  fused  with  potash  it  is  converted  into 
hydroxychrysazin  G14H  gO «.  Quinizarin  forms  a 
Hiacetate  which  melts  at  200''. 

Literature. — Baeyer  and  Caro  (Ber.  8,  162) ; 
Schonck  and  R5mer  (Ber.  10, 654)-;  Bayer  &  Co. 
P.  R.  P.  81245  (see  also  above). 


Leuooquinliarlil  is  obtained  by  the  reduction 
of  quinizarin  with  sodium  hymosulphite  and 
sodium  hydroxide.  It  is  a  vellow  orjrstalline 
substance  melting  at  135**,  and  is  of  importance 
since  it  condenses  with  aromatic  amines  more 
readily  than  quinizarin  itself,  and  is  thus 
employed  in  the  manufacture  of  some  of  the 
important  acid  dyes  of  this  group. 

2-NltroqiilnlzaiiJl  is  the  product  obtained 
by  the  nitration  of  quinizarin  in  acetic  acid  or 
nitrobenzene  solution.  It  forms  brick-red  crys- 
tals which  dissolve  in  sulphuric  acid  to  a  cerise 
solution  and  dyes  wool  brown  on  an  alumina 
mordant,  violet-brown  on  chromed  wool. 

Qnlnlariii  fulphonle  Mid  is  obtained  by  the 
action  of  sodium  sulphite  on  a  hot  aqueous 
suspension  of  quinizarin,  preferably  in*  the 
presence  of  an  oxidising  agent  such  as  pyro- 
lusite. 

Fuming  sulphuric  acid  (70-80  p.c.  SO,)  in 
large  excess  converts  quinizarin  at  20^-40*'  into 
1:2:5:  8-tetrahydroxyanthraquinone  (Schmidt 
Bull.  Soc.  chim.  1914,  (15)  12,  1). 

The  hydrogen  atoms  in  quinizarin  are  not 
readily  displaced  by  halogens,  but,  on  the  other 
hand,  an  additive  product,  a  hexdbromide  is 
formed  at  0®.  At  40°  the  product  is  hromo- 
quinizarin  dibromide,  and  even  at  temperatures 
between  lOO""  and  230''  only  a  dibramoderivatitfe 
is  produced. 

Dlehloroquinlzarinas.  3  :  6-,  3 : 4-,  and  4  : 5- 
Dichlorophthalic  anhydrides  react  with  quinol 
in  presence  of  boric  add  to  produce  dichloro- 
dihydroxybenzoyl  benzoic  acids  which  are 
changed  by  sulphuric  add  into  corresponding 
diohloroquinizannes. 

5 :  8-Dlehloraqulnlzailii  crystallises  in  brown- 
red  needles  melting  at  266°,  and  forms  an  tuietyl 
derivative  melting  at  170°.  When  its  potassium 
salt  is  heated  with  potassium  phenoxide  during 
eiffht  hours  at  180°  it  is  changed  to  S-chloro-b- 
phenoxyquinizarin,  light  red  needles  melting  at 
243°.  The  phenoxy  derivative  is  transformed 
by  p-toluidine  at  150°  in  presence  of  potassium 
and  copper  acetates  into  S-p-idluidino-6-phenoxy' 
quinizarin  (m.p.  278°).  5  :  8-Dichloroquinizarin 
reacts  sinulany  with  aniline  forming  5 : 8- 
dianUinoquinizarin  melting  at  246°. 

5 : 6-Dlehloroqiiliilzariii  melts  at  208°,  and 
its  acetyl  derivative  at  140°. 

6 : 7-Diehloroquliilzariii  melts  at  288°  and 
forms  an  acetate  melting  at  125°. 

Literature.— M,  Frey  (Ber.  45,  1368). 

Add  dyes  derived  from  qoiiiizarin  or  Its 
derivatives.  Quite  a  considerable  sub-group  of 
anthracene  dyes  have  been  obtained  by  acting 
on  quinizarin  or  its  derivatives  with  amines 
usually  in  presence  of  boric  acid.  One  or  two 
of  the  hydrbxyls  of  quinizarin  may  be  replaced 
by  arylamino  groups,  or  if  desired,  one  of  the 
groups  introduced  mav  be  amino  or  alkylamino. 
The  products  are  sulphonated  and  are  then  acid 
wool  dyes.  The  firm  of  Gassella  occasionally 
condense  leucoquinizarin  with  ready  formed 
toluidine  sulphonic  acid  in  presence  of  boric 
acid.  Friedlander  and  Schick  (Zeitsoh.  Farben 
u.  TextU  Chemie,  1902,  2,  429 ;  1903,  3,  218) 
have  shown  that  the  reaction  *  leading  to  the 
formation  of  these  dyes  is  reversible  in  the  case 
of  the  condensation  with  leucoquinizarin,  and 
have  applied  this  observation  in  order  to  hydro- 
Ivse  some  dves  found  in  commerce  and  so  prov 


128 


ALIZARIN  AND  ALLIED  COLOURING  MATTERS. 


their  nature.  The^  find  that  add  dyes  of  this 
fleries  which  contain  a  sulphonated  anilino-  or 
tolnidino-  gronp  will  usually  yield  leucoquini- 
zarin  or  similar  suhstanoe,  together  with  an 
aniline  or  toluidine  sulphonic  acid  by  boiling 
with  stannous  chloride  in  aqueous  alcoholic 
hydrochloric  add  solution. 

Alizarin  Emeraldol  G,  Alizarin  Uranole  R» 
Alizarin  Geranol  B,  Alizarin  Heliotrope  R,  BB, 
and  Alizuin  Marine  Blue  RG,  W,  are  examples 
of  acid  dyes  of  similar  type  to  those  described, 
but  of  undisclosed  constitution. 

Qnlnlzariii  Bine 


0 


/C0\ 

\co/ 


OsNa 


This  dyestuff  is  prepared  by  heating  quini- 
zarin  and  aniline  in  molecular  proportions  and 
sulphonatinff  the  product.  From  an  add  bath 
it  dyes  wool  a  rea  shade  of  blue,  and  gives  a 
greenish-blue  with  chromed  wool. 

Alizarin  Irisol  D  (R)  (Bayer,  D.  R.  PP. 
80100  and  91149). 

OH 


SO.H 


Quinizarin  or  leucoquinizarin  is  condensed 
with  p-toluidine  and  tne  product  sulphonated. 
The  substance  is  isomeric  with  Alizann  Oyanol 
Violet  {q.v,). 

Alizarin  Cyanol  Violet  R  (Cassella,  D.  R.  PP. 
172464  and  181879). 

NH— ^^CH, 

Leucoquimzarin  is  condensed  with  4-amino- 
toluene-2-sulphonic  add  and  the  product 
oxidiBed. 

Alizarin  Pure  Blue  and  Alizarin  Blue  GO  have 
the  respective  formulas  : — 


derivatives,  and  these  are  condensed  with  aniline 
and  sulphonated. 
Alizarin  Astrol 

0^^      NHMe 

^^       NH'C,H,SO,H 

dyes  wool  greenish-blue  from  an  acid  bath. 

Alizari^  RuMnol  0, 8G,  GW  (Bayer,  D.  R.  P. 
201904) 


•C^H.-SOtH 


is  obtained  by  the  sulphonation  of  p-toluidino* 
N-methvlanthrap3aidone.  It  dyes  wool  in  red 
sKades  from  an  acid-bath. 

Quinizarin  Green. 

Quinizarin  is  treated  with  an  excess  of 
aniline  and  the  product  sulphonated.  The  dye- 
stuff  is  the  sodium  salt  of  the  sulphonic  acid,  and 
has  the  constitution 


0,Na 


NH, 
Br 


OCQ 


\co/ 


NHC.H4S0,H 


OCX)_ 


0,Na. 

The  men  shades  produced  on  wool  from  an 
acid- bath  are  fast  to  fight  and  milling. 

Anthraqulnone  Green  is  the  corresponding 
monosulphonic  acid. 

Alizarin  Cyanlne  Green  E,   G   Extra,   K 
(Bayer) 

NH-C.H4(CH,)S0,H 


^/OOy^ 


NHC,H,(CH,)S0,H 


Alizarin  Cyanol  B  (Cassella,  D.  R.  PP. 
183395,  114262,  119362).  The  mixture  of  I  :  5- 
and  1  : 8-anthraquinone  disulphonic  acids  is 
changed  by  ammonia  and  sodium  chlorate  at 
170°  to  corresponding  diamine  anthraquinones 
amd  aminoanttiraqjiinonesulphonic  acids.  The 
latter    are    brominated    to    mixed    dibromo- 


^      NH-O.H,(CH,)SO,H 

This  dye  is  obtained  by  sulphonathifr  the 
product  of  the  complete  tolylation  of  quinizarin. 
it  dyes  wool  from  an  acia  bath  a  very  vivid 
green.  This  dye  has  now  displaced  for  most 
purposes  the  Alizarin  Viridine  which  is  similarly 
prepared  from  Alizarin  Bordeaux.  An  isomeride 
with  very  similar  properties  is  Alizarin  BriUiani 
Oreen  0,  8E  {CaaseUa),  and  the  difference  in 
constitution  is  the  same  as  that  between  Alizarin 
Irisol  and  Alizarin  Cyanol  Violet.  The  dye  now 
in  question  is  obtained  by  carrying  to  the  second 
staee  the  condensation  between  leucoquinizarin 
and  4-aminotoluene-2-sulphonic  add. 

Hystazarin.    2 : 3-Dihydroxyanthraquinone, 

^•«4*\C0^^«"«\0H.  (3) 
This  substance  is  formed,  together  with  ah'zarin, 
when  a  mixture  of  pyrocatechol  and  phthalic 
anhydride  is  treated  with  sulphuric  acid — 5 
grams  of  pyrocatechol,  6*8  grams  phthalio 
anhydride  and  76  grams  sulphuric  acid  are  heated 
for  4|  to  5  hours  to  340-150*  on  a  sand-bath. 


ALIZARIN  AND  ALLIED  COLOURING  MATTERS, 


129 


The  resalting  product,  whUe  still  warm,  is 
poured  into  }  litre  of  water,  heated  to  boiling, 
and  filtered  hot. 

The  dark-green  precipitate  thus  obtained  is 
well  washed  with  hot  water,  dissolved  in  dilate 
potash,  and  the  dark- blue  solution  precipitated 
by  dilute  sulphuric  acid.  The  precipitate  is 
crashed  with  water,  dried  on  a  porous  plate,  and 
Seated  with  boiling  alcohol  in  an  extraction 
apparatus,  by  which  means  a  considerable  por- 
tion is  dissolved. 

The  dark-red  solution  on  evaporation  yields 
an  orange-red  mass,  which  consists  of  alizarin 
and  hystazarin.  These  two  substances  are 
readily  senarated  by  treatment  with  boiling 
benzene,  which  dissolves  the  alizarin  and  leaves 
the  hystazarin  ;  the  latter  may  then  be  further 
purified  by  reorystaUisation  from  acetone. 

Yield  1}  p.o.  alizarin  and  12  p.o.  hystazarin 
of  pyrooatechol  used. 

The  following  conditions  for  the  preparation 
have  also  been  published :  30  grams  p3^o- 
catechol  are  heated  with  42  grams  phthalio 
anhydride  and  300  grams  sulphurio  acid  at 
180^-200^  for  half  an  hour.  Yield  of  hystazarin 
was  6  grams,  and  of  alizarin  1  flram. 

Hystazarin  may  be  syn^esised  by  the 
following  series  of  reactions  i — Phthalio  anhydride 
condenses  with  veratrol  in  carbon  disulphide 
solution  under  the  influence  of  alummium 
chloride. 


oo^o: 


OMe 
OMe 


Phthalle  anhydride. 


\Aco 


YeratroL 

,^--Ay^OMe 

S :  4 :  dlmethozybensosrl- 
bensoic  add. 

The  3  :  4-dimethozybenzoylbenzoio  acid 
thus  produoed  yields  2:3:  dunethoxyanthra- 
quinone  on  heatmg  with  concentrated  sulphurio 
acid.  This  is  hystazarindimethyl  ether  and 
yields  hystazarin  on  demethylation. 

Hystazarin  crvstallises  from  aoetone  in 
orange-yellow  needles,  which  do  not  melt  at  260^ 

It  is  almost  insoluble  in  benzene,  difficultly 
soluble  in  xylene,  soluble  in  hot  alcohol*  ether, 
glacial  aoetio  aoid,  and  acetone. 

Jt  dissolyes  in  alkalis  with  a  blue  (corn- 
flower) colour,  in  ammonia  with  a  violet  colour, 
and  in  oonoentrated  sulphurio  aoid  with  a  blood- 
red  colonr.  The  barium  salt  is  a  blue  procipi- 
tate,  the  calcium  salt  a  violet  precipitate ;  both 
are  insoluble  in  water. 

Hystazarin  possesses  only  very  feeble  tinc- 
torial properties.  The  faint  red  colour  pro- 
duced with  an  aluminium  mordant  differs  in 
shade  from  the  alizarin  red.  The  solution  of 
hystazarin  in  dilute  sodium  hydrate  absorbs 
the  yellowish  red  and  violet  rays  of  the  spectrum. 
A  very  dilute  solution  shows  two  lines  in  the 
yellow,  Xmm6i9'B,  \^681'4.  Distilled  over  zino- 
dust,  hystazarin  yields  relatively  laige  quantities 
oi  anthracene. 

Hystazarin  is  changed  by  sulphuric  acid  at 
200^  slowly  into  alizann.  It  is  probable  that 
the  reaction  is  one  of  hydrolysis  into  phthalio 
acid  and  catechol  and  subsequent  condensa« 

Vou  I— T. 


tion  in   the  ortho-   position  to  the  hydrozyl 
group. 

LUeraiure,  —  Liebermann  and  SchoeUer 
(Ber.  21,  2501-2508) ;  Lagodzinski  and  Lor^tan 
(6er.  28,  118);  Liebermann  and  Hohenemser 
(Ber.  35,  1778);  Schrubsdorf  (Ber.  36, 
29;i6). 

Dlacetyl  hystazarin  Ci4H«0s(0C,H,0)f  crys- 
tallises  from  acetic  acid  in  needles,  which  mdlt  at 
205*»-207'*. 

2 : 3-(2»Hydroxyaiitbranol  is  obtained  by  the 
reduction  of   hystazarin   with    zinc  dust   and, 
ammonia.    It  occurs  in  yellow-brown  needles 
melting  at  282"^,  and  forms  a  triaceiyl  (UHvaHvt 
meltimr  at  163^ 

1  -introhystazarin  is  obtained  when  hystazarin 
is  nitrated  in  sulphuric  acid  solution  by  means 
of  a  molecular  proportion  of  nitric  acid.  Further 
nitration  leads  to  1 :  ^-diniiff^yMcaarint  and 
both  these  derivatiyes  have  only  a  slight 
tinctorial  power  on  mordants. 

1 : 4-Dibromoliystuariii  is  obtained  by  bromi- 
natinff  the  substance  at  150°  in  a  sealed  tube. 
It  melts  at  127''-129''  and  dissolves  m  alkaline 
solutions  with  a  violet  colour. 

Anfhraflavie  add.  2 : 6-Dihydroxyanthra- 
quinone 


Anthraflavio  acid  is  prepared  by  fusing  a-anthra- 

auinone  disulphonic  acid  with  potash,  and  is 
^erefore  nearly  always  present  in  artificial 
alizarin.  Synthetically  it  has  been  obtained  by 
heating  m-hydrozybenzoio  aoid  with  sulphurio 
acid  to  190'. 
20HC,H4C00H 

-0H-C,H,<[^Q^,H,0H :  H,0. 

This  mode  of  formation  proves  that  this  sub- 
stance contains  the  two  hydrozyl  groups  in 
different  benzene  rings. 

Anthraflavio  acid  crystallises  from  alcohol  in 
yeUow  needles  which  melt  above  330^.  The  puro 
substance  when  carefully  heated  sublimes  par- 
tially in  yellow  needles,  leaving  a  considerable 
quantity  of  a  carbonaceous  residue.  Anthraflavio 
acid  does  not  dye  mordanted  doth.  It  dissolves 
in  alkalis  forming  a  yellowish-red  solution,  and 
in  sulphurio  acid  forming  a  green  solution,  the 
absorption  spectrum  of  which  shows  a  broad 
band  oetween  the  blue  and  the  sreen.  Anthra- 
flavio aoid  forms  a  number  of  salts,  of  which  the 
sodium  salt  is  the  most  oharaoteristia  This  salt 
is  sparingly  soluble  in  water,  and  is  remarkable 
for  the  ease  with  which  it  crystallises ;  this  dis- 
tinguishes it  from  Moanthraflavio  acid,  and  gives 
a  r^idy  means  of  separating  these  two  substances. 
When  treated  with  acetic  anhydride,  anthraflavio 
acid  forms  a  diaoetate  melting  at  228*-229*. 

LUeraiuft, — Perkin  (Chem.  Soc.  Trans.  1871, 
24, 1109 ;  26, 19) ;  Schunck  and  Romer  (Ber.  9, 
379;  11,  970);  Liebermann  (Ber.  5,  968); 
Rosenstiehl  (Bull  Soa  ohim.  29,  401-434); 
Barth  and  Senhof er  f  Ber.  170.  100). 

Tetranltroanthraflavle  acid  consists  of  yellow 
needles  exploding  without  fusion  at  807^ 
It  is  obtained  by  the  action  of  nitric  acid  on 
anthraflavio  aoicL  By  the  employment  of  the 
calculated  amount  of  nitric  acid  it  is  possible 
to  obtain  a  dinitro  derivaiive  which  dyes  wool 
from  an  acid- bath. 


130 


ALIZARIN  AND  ALLIED  COLOURING  MATTERS. 


Litenrtitra.— Schradinger  (Ber.  8,  1487). 
itfoAnthraflavle  add.  2 : 7-Dihydroxyanthra- 
quinone 

(7)  HO-C.H,<;gg>C.H,OH  (2) 

is  formed  when  ^-anthraquinone  disulphonio  acid 
is  fused  with  potash,  and  is  therefore  fuways  con- 
tained in  orade  alizarin.  In  preparmg  it»  cmde 
alizarin  is  dissolved  in  dilate  caustic  soda,  the 
solution  pecipitated  with  hydrochloric  acid,  and 
the  precipitate  dissolved  in  cold  baryta  water 
%nd  filtered.  (In  this  way  woanthranavic  acid, 
which  forms  a  soluble  baryta  compound,  \b  easily 
separated  from  alizarin,  anthrapurpurin,  and 
anthraflavic  acid,  which  yield  insoluble  barium 
compounds.)  The  filtrate  is  treated  with  hydro- 
chloric acid,  and  the  precipitate  recrystallised 
from  alcohoL  /«oantlurafiavio  acid  crystallises, 
in  long  yellow  needles,  containing  1  mol.  H,0, 
which  can  be  driven  off  at  150^  It  melts  above 
330^  and  sublimes  at  a  high  temperature  in 
lustrous  yellow  needles.  It  dissolves  easily  id 
alkalis  forming  a  deep-red  solution,  but  it  does 
not  dye  mortumted  cloth.  Fused  with  potash 
t^oanthraflavio  acid  yields  anthrapurpurin. 

The  diacetate  of  i «oanthraflavic  acid  melts  at 
196'. 

Liiernture. — Schunck  and  Romer  (Ber.  d 
379). 

Anthrarufin*    1  :  5-Dihydroxyanthraquinone 

(6)  HO-C.H,<^g>C,H,OH.  (1) 

Anthrarufin  is  formed  together  with  anthraflavic 
acid  and  metabenzdioxyanthraquinone  by 
heating  m-oxybenzoic  acid  with  sulphuric  acid. 

(2)  0H-C,H4-C00H 

=OH-C,H,<^^^,H,OH  -f  2H,0. 

It  may  also  be  obtained  by  fusing  o-anthra- 
quinone  disulphonio  acid  with  potash. 

Another  process  depends  on  the  fact  that  it 
is  the  chief  product  when  anthraquinone  is 
oxidised  with  sulphur  trioxide  under  the  following 
conditions : — ^Anthraquinone  (50  parts)  is  heated 
with  fuming  sulphuric  acid  ( 1000  parts  containing 
80  p.c.  SO,)  an(l  boric  acid  (20  parts)  for  36 
hours  at  100^  under  pressure. 

Anthrarufin  va  manufactured,  mainly  as  an 
intermediate  for  alizarin  saphirol,  by  heatinf 
anthraquinone- 1 : 5-disulphonic  acid  with  n^ 
of  lime  under  pressure. 

Anthrarufin  crystallises  in  yellow  needles 
which  melt  at  280°  and  sublime  easily  at  a  higher 
temperature  (distinction  from  anthraflavic  acid). 
It  dissolves  with  difficulty  in  ammonia  and  soda, 
but  more  readily  in  potash. 

Anthrarufin  dissolves  in  sulphuric  acid, 
forming  a  deep-red  solution,  the  colour  of  which, 
is  so  intense  that  it  is  still  easily  apparent  in 
solutions  containing  only  1  part  in  10,000,000. 

Anthrarufin  forms  a  diacetate  which  melts 
at  244<'-24d^ 

Antbranifln  dimethyl  ether  is  obtained  on 
boilinfl  1:5:  dinitroanthraquinone  with  methyl 
alcohmic  caustic  soda.  The  substance  forms 
deep-red  needles  of  m.n.  230°. 

LikrtUurt. — Schunck  and  Romer  (Ber.  11, 
1175) ;  Liebermann  and  Dehnst  (Ber.  12,  1289) ; 
Bayer  and  Co.  D.  R.  P.  101220 ;  Pleus  (Ber. 
35,  2923). 


Anthrarafln  monoetliyl  ether  occurs  in  yellow 
needles  melting  at  i^^  and  yielding  an  acetyl 
derivative  melting  at  173°. 

Anthrarafln  diethyl  ether  forms  long  silky 
needles  melting  at  178°. 

Alizaiin  Sapliirol  B.  Alizarin  DelphinoL 


OH 


NaSO, 


NH, 


NH, 


00 


Nx)/^ 


S0,Na 


is  an  important  blue  acid  wool-dye  derived  from 
anthrarufin  by  successive  sulphonation,  nitration, 
and  reduction.  This  dyestuff  excels  in  respect 
to  its  fastness  to  light. 

It  may  also  be  obtained  by  the  reduction  of 
1 : 5-dinitroanthraquinone  Iq  alkaline  solution 
followed  by  acidification  and  sulphonation. 
The  first  product  is  a  dihydroxylaminoanihra- 
quinone,  and  this  zearranfes  into  an  amino- 
compound  by  the  action  of  the  acid.  Dinitro- 
anthrarufin  may  also,  form  the  source  of  this 
or  a  verv  similar  dyestuff  into  which  it  is  con- 
verted by  the  action  of  sulphites.  Alizarin 
Saphirol  8E  is  the  monosulphonic  add.  Theire 
are  also  dyestuffs  of  this  type  which  contain  a 
bromine  atom  in  the  anthraquinone  nucleus. 

Alizarin  Geiestoi  is  obtained  by  the  action 
of  formaldehyde  on  Alizarin  Saphirol. 

1 :  d-Dihydroxyanthraquinone 

(6)  HOC,H,<^g>C.H,OH  (1) 

This  was  the  last  of  the  dihydroxyanthra- 
quinones  to  be  obtained,  it  having  tieen  pre- 
pared by  Frobenius  and  Hepp  in  1^7  (Ber.  40, 
1048).  l-Nitroanthraquinone-6-sulphonic  acid 
was  converted  by  sodium  methoxide  into  1- 
methoxyanthraqumone-6-sulphonic  acid,  and 
the  lattCT' hydrolysed  to  a  hydroxy  anthraqui- 
none sulphonic  acid  by  heating  witn  sulphuric 
acid.  Tne  sodium  salt  was  then  prepared  and 
heated  with  milk  of  lime  at  195°  under  pressure. 
The  substance  crystalliBes  in  orange-yellow 
needles  melting  at  §71°-272°,  and  dissolvinff  in 
ammonia  or  potassium  hydroxide  to  a  yeUow 
solution.  Oxidation  by  heating  under  pressure 
with  a  solution  of  sodium  hydroxide  and  sodium 
nitrate  results  in  the  production  of  flayopur- 
purin. 

Metabenidioxyanthraqninone.  1 : 7-Dihy- 
droxyanthraqninone  ^ 

(7)  HO-<:J,H,<3o^C,Hr-OH  (1) 

Lileraiure. — Schunck  and  Romer  (Ber.  11, 
1176) ;  Liebermann  and  Dehnst  (Ber.  12, 
1289). 

Metabenzdihvdroxy anthraquinone  0 1 JS  ,0 , 
is  formed  togetner  with  anthraflavic  acid  and 
anthrarufin  by  heating  m-hydroxybenzoic  acid 
with  sulphuric  acid  {v.  supra).  It  is  separated 
from  these  by  treatment  with  benzene  and 
subsequent  recrystallisation  &om  dilute  alcohoL 
Metabenzdihydroxyanthraquinone  forms  yel- 
lowish needles  which  melt  at  29r>293°,  and 
sublime  at  a  higher  temperature  almost  without 
decomposition.  It  dissolves  in  alkalis  with  a 
dark-yellow  colour,  and  in  concentrated  sul- 
phuric acid,  forming  a  brownish-yellow  solution, 
which  shows  no  ab^rption  bands. 


ALIZARIN  AND  ALLIED  COLOURING  MATTERS. 


m 


The  diaoetate  of  metabenzdihydroxyanthra- 
qninone  melts  at  199*'. 

Liieraiure, — Sohunck  and  Rdmer  (Ber.  10, 
1226) ;  Rosengtiehl  (Ber.  9,  946). 

Cnbffysazln.  1 :  S-Dihydroxyanthraquinone  is 
fckrmed  by  Ifiisiiig  x-<^^li'^uinonodisiilphonic 
acid  with  potash,  or  by  treating  hydrochrysamid 
G,4H,(NH,)4(0H),0|  with  nitrous  acid  and 
alcohol.  (N.B. — ^Hydrochrysamid  is  obtained 
by  the  reduction  of  chrysammio  acid 
Ci4H4(N0t)404,  which  is  the  product  of  the 
action  of  nitric  acid  on  aloes.) 

It  is  manuf  actored  by  heatinff  anthraquinone- 
1 : 8-disul^onic  acid  with  milk  of  lime  under 
preesore  with  or  without  the  addition  of  calcium 
chloride. 

Chrysazin  forms  reddish-brown  needles, 
which  melt  at  191°.  It  dissolves  in  alkalis  and 
sulphuric  acid,  with  a  red  colour.  Its  diacetate 
m  Jts  at  227''-232''. 

Crude  dinitroanthraquinone  contains  a  com- 
pound which  is  converted  into  chrysazin  dimethyl 
ether  on  treatment  with  methyl  alcoholic  potash. 

LUeraivre, — ^Liebermann  (Annalen,  183,  184). 

DertvattT6S  of  ChryBaziii. 

Honopotaniaiii  salt.  Chrysazin  is  dissolved 
in  a  little  hot  dilute  potassium  hydroxide  solu- 
tion. The  salt  separates  in  orange-red  needles 
which  contain  water  of  crystallisation,  and  on 
heating  at  100°  becomes  anhydrous,  the  colour 
changing  to  violet. 

Chr^anfhranol,  1:8-  Dlhydroxyanthnuiol. 
This  substance,  which  possesses  therapeutic 
value  similar  to  that  which  characterises 
chrysarobin,  may  be  obtained  by  the  reduction 
of  chrysazin  with  hydriodic  acid  and  phosphorus. 
It  melts  at  177°,  and  forms  a  triacetyl  derivative 
melting  at  210°. 

4 : 6-Dieliloroeliiysaiin  is  obtained  by  passing 
chknine  into  a  suspension  of  chrysazin  in  sul- 
phuric acid  of  such  a  concentration  that  the 
b.p.  is  120°. 

Ghryniiiiaiiiide,  l-Aiiilno-8-hydrozyaiithra- 
qnlnone  is  obtained  by  saturating  a  chrysazin 
paste  with  ammonia  at  0°  and  heating  in  a 
teaJied  tube. 

Chrynxlii-disalplioiile  add  ia  obtained  by 
anlphonation  of  chrysazin  with  oleum  (20  p.o. 
SO,).  It  is  isolated  as  a  potassium  salt,  and 
on  fusion  with  alkali  yields  a  dihydroxychrysazin 
melting  at  292°  (acetyl  derivative,  m.p.  233°- 
940°)  and  isomeric,  but  not  identical  with  a 
tetrtLhydrotyanthraquiool^  obtained  by  fusiiu; 
chrysazin  with  potanium  hydroxide  in  a  vacuuiK 
The  latter  substance  ooours  in  dark  red  needles 
melting  at  217°,  and  fonning  a  tetraoetyl  deri- 
vative melting  at  196% 

Dbiltroehmtfiii  (probably  4 : 6-dinitro-l :  8- 
dihydroxyanthraqmnone).  Chrysazin  dimethyl 
ether  (obtained  from  1 :  8-dinitroanthraquinone 
by  the  action  of  sodium  methoxide)  is  nitrated 
by  meaue  <xf  ^  mixture  of  nitric  and  sulphuric 
acida.  The  resulting  dinUnxMjfmmn  dtmdhyl 
dker  eiystallises  from  ohlorobenzene  in  green 
needlee  meUanff  at  232°-233°.  It  may  be 
hydrolyaed  by  not  10  p.a  sulphuric  add,  and 
tbe  dmitrochryBazin  separates  from  chloro- 
h^mtMtuk  in  qnnge-yeUow  crystals  melting  at 
232°-234°.  Cnrysazin  is  coming  more  and  more 
into  use  as  an  intermediate  for  the  preparation 
ol  dyestufb,  and,  for  example,  the  processes 
wfalcn  are  used  to  convert  anthrarnfin   into 


Alizarin  Saphirol  may  also  be  applied  to  chry- 
sazin, and  the  product  is  a  valuaole  wool  dye. 
For  this  reason  it  is  not  the  invariable  practice 
to  separate  anthraquinone-1 :  6-  ana  1  :  8- 
disulpfionic  acids,  but  instead  the  mixture  may 
be  converted  into  a  mixture  of  anthrarufin  and 
chrysazin,  and  by  successive  sulphonation, 
nitration,  and  reduction,  either  with  stannous 
chloride  or  with  sodium  sulphide,  a  useful  dye 
of  Alizarin  Saphirol  type  obtained. 

There  is  further  a  general  similarity  between 

Suinizarin,  anthrarufin,  and  chrysazin  as  regards 
^e  production  of  acid  dyes  by  condensation 
with  aromatic  amines  followed  by  sulphonation. 
Thus  condensation  of  anthrarufin  and  p-toluidine 
followed  by  sulphonation  of  the  product  leads 
to  the  dyestuff  Anthraquinone  Violet,  and  similar 
products  may  be  prepared  from  chrysazin. 
Chrysazin  is  not  a  mordant  dyestu£f,,but  dinitro, 
dihydroxylamino,  and  diaminochrysazins  can 
be  applied  to  mordanted  fabrics.  The  dinitro 
compound  dyes  chromed  wool  blue. 

Zt<€ra<ttre.— ^chrubsdorff  (Ber.  36,  2936); 
Wobling  (Ber.  36,  2941) ;  Nolting  (Chem.  Zeit. 
1910,  977 ;  J.  Soc.  Chem.  Ind.  1898,  372 ;  1900, 
342;   1906,314). 

Dihydroxyantbraqalnono  (T),  described  as 
isochrysazin,  has  been  obtained  by  Lifschfitz 
(Ber.  17,  897)  by  treating  dinitroanthraquinone 
with  concentrated  sulphuric  acid. 

It  crystallises  from  alcohol  and  ether  in 
deep-red  needles,  which  melt  at  176°-180°.  It 
dissolves  in  alkaUs  and  in  ammonia  with  a 
reddish- violet  colour,  and  in  sulphuric  acid  with 
a  reddish  yellow  colour,  mien  heated  it 
sublimes  readily,  and  at  a  comparatively  low 
temperature,  in  orange-red  plates  or  needles. 
It  does  not  dye  morduited  doth. 

The  diacetyl  compound  melts  at  160°-166°. 

In  view  of  the  fact  that  dinitroanthraquinone 
is  a  mixture  of  the  I  :  6-  and  1  : 8-isomeride9, 
it  appears  very  probable  that  this  supposed 
dihyarojTf  anthraquinone  is  a  mixture. 

feoDstftatloii  of  the  dlhydroiyaiithnmiiliioiief. 
The  synthesis  of  quinizarin  from  phthalic 
anhydride  and  quinol  establishes  its  constitution 
as  1 : 4-dihydroxyanthraquinone 

OH 


nAcoA^ 


OH 

Further  ab'zarin  and  hystazarin  are  produced  by 
the  condensation  of  phthaUo  anhydride  with 
catechol. 

It  follows  that  these  oolourinff  niatters  are 
represented  by  the  following  formuue : — 

\/\coAs/ 

L  IL 

The  synthesis  of  alizarin  from  hemipinic  add  is 
condusive  evidence  that  the  formula  I.  represents 
^liyApq^  and  consequently  IL  is  the  structure  of 
hystazarin. 

Again,  purpurin  is  produced  by  the  oxidation 
of  both  alizarin  and  quinizarin,  and  must  there- 
fore be  1 ;  2  :  4-trihydroxyanthraquinone 


132 


AUZARIN  AND  ALLIRD  OOLOURING  MATTEIU3. 


OH 


On  reduction  it  yields  neither  alizarin  nor 
quinizarin,  but  purpurozanthin,  which  is 
obviously  2 : 4-dihydrozyanthraquinone  (the 
same  position  as  1:3). 

Similar  aignments  can  be  developed  with 
respect  to  the  remaining  isomerides  of  alizarin. 

Alizarin  Indigo  G  (Bayer,  D.  R.  P.  237199) 


This  is  a  vat  dye  obtained  by  the  condensation 
of  dibromoisatin  chloride  with  a-anthrol.  The 
solution  in  sodium  hydrosulphite  is  yellow- 
brown,  and  cotton  is  dyed  in  pure  greenish-blue 
shades  of  ezo^lent  fastness. 

III.  TrihydrozyanthrftqaJnones :  Anthrspor- 
pnrin,  /tfoporparin,  HydrozyMoanUmflavie  ae)d. 
1:2: 7-Trihydroxyanthraquinone 

OH 


/\/^\/\0H 


This  important  colouring  matter  is  contained 
in  crude  artificial  alizarin.  It  is  formed  by  fusing 
i^anthraquinonedisulphonio  acid,  Moanthra- 
flavio  acid,  metabenzdihydrozyanthraquinone, 
or  a-dibromanthraquinone  with  potash. 

The  preparation  of  this  substance  is  a  some- 
what teuious  process,  dependent  on  the  fciot  that 
anthrapnrpurin  differs  from  alizarin  in  the 
behaviour  of  its  alumina  lake.  The  former,  on 
treatment  with  an  alkaline  carbonate,  is  dis- 
solved, whilst  the  alizarin  lake  remains  un- 
attacked.  The  solution  containing  the  anthra- 
purparin  is  filtered  from  the  alizarin  lake,  heated 
to  boiling,  and  acidified  with  hydrochloric  aoid. 
The  anthnpurpurin  thus  obtained  is  purified  by 
conversion  into  its  difficultly  soluUe  sodium 
compound,  and  from  this,  by  precipitation  with 
barium  chloride,  the  barium  salt  is  obtained, 
,which  is  decomposed  with  hydrochloric  acid. 
The  precipitate  is  collected  on  a  filter,  well  washed 
with  water  and  recrystallised  from  glacial  ace- 
tic acid.  ' 

As  already  mentioned  above,  the  manufacture 
of  alizarin  always  implies  the  production  of  a 
certain  amount  of  the  anthraqumone  2  :  6-  and 
2 : 7-disulphonic  acids,  and  the  methods  by 
which  these  substances  are  isolated  have  been 
discussed.  On  fusion  witii  alkali  it  is  possible 
to  obtain  from  these  sulphonic  acids  eitner  the 
coiresponding  dihydroxyanthraquinones  or,  on 
the  other  hand,  to  imitate  the  alizarin  fusion 
and  to  introduce  a  further  hydroxyl  group. 
In  this  way  anthrapuipurin  and  flavopurpurm 
are  prodnced  on  a  commercial  scskie.  The 
temperature  of  the  fusion  must  be  considerably 
higher  than  that  which  suffices  for  the  conversion 
of  *  silver  salt  *  into  alizarin.  The  conversion 
of  anthraflavic  acid  and  isoanthraflavic  acid  into 
corresponding  trihydrozyanthraquinones  occurs 
with  very  di&rent  rapidity,  the  former  substance 


(which  yields  anthrapurpurin)  reacting  sluggishly. 
Wedekmd  and  Ck>.  (D.  R.  P.  1949&)  fuse  100 
parts  of  anthraflavic  acid  with  50  parts  of  salt- 
petre and  1600  volume  parts  ot  caustic  lye 
(b.p.  185°)  at  215°-225°.  Bayer  (D.  R.  PP. 
205097  and  223103)  employ  only  a  20  p.c. 
caustic  soda  solution  and  a  temperature  of 
180°-200*'.  If,  however,  in  fusing  the  disul- 
phonic  acids  with  alkali  the  temperature 
neoesBaiy  is  quickly  reached,  it  is  probable  the 
reaction  fint  leads  to  alizarin  sulmionio  acids, 
which  are  subsequently  changea  to  anthra- 
purpurin and  flavopurpurin.  The  following 
example  of  the  proportions  used  in  the  fusion 
may  be  given : — 

Two  cbm.  of  the  disulphonic  acids  liquor 
(obtained  as  already  described)  containing 
solid  in  suspension  and  with  a  dry  content 
amounting  to  27*65  p.c,  equivalent  to  653  kg. 
of  the  sodium  salts,  is  mized  with  180  kg. 
saltpetre  and  1012  litres  of  soda  lye  of  45°  B?. 
(containing  618  ks.  NaOH).  This  mizture  is 
heated  neariy  to  boiling,  and  three  drums  of 
solid  caustic  soda  then  added  (795  kg.).  This 
procedure  ensures  the  rapid  heating  of  the 
mizture  which  is  so  neoessarv  to  obtain  good 
resulto.  The  reaction  is  camea  out  in  apparatus 
similar  to  that  used  for  the  preparation  of 
alizarin,  and  the  operation  of  tusion  occupies 
48  hours.  The  product  is  worked  up  mn<^ 
in  the  same  way  as  alizarin,  and  is  brought  into 
commerce  in  the  form  of  a  paste.  The  impuriW 
present  in  these  trihydrozyanthraquinones  is 
usually  anthraflavic  acid,  and  this  may  be 
separated  by  teking  advantage  of  the  insolu- 
bility of  the  sodium  salt  of  anthraflavic  acid  in 
sodium  hydrozide  solution  of  10°-12°  B6.  In 
order  to  separate  the  anthraflavic  acid  it  is 
accordingly  merely  necessary  to  dilute  to  this 
concentration  and  filter  off  the  sodium  anthra- 
flavate. 

Anthrapurpurin  ciystallises  in  orange- 
coloured  needles,  which  melt  above  330°,  and, 
when  carefully  heated,  sublime  in  long  red 
needles.  It  dissolves  in  alkalis  with  a  violet 
colour ;  the  solution  shows  the  same  absorption 
spectrum  as  aUzarin 

With  acetic  anhydride  anthrapurpurin  forms 
a  triacetate  OuHs(CtH,0),Os,  which  crystallises 
in  yellow  needles,  meltmg  at  220°. 

By  careful  hydrolvsis  the  triacetyl  deriva- 
tive may  be  converted  to  a  diacetyl  derivative, 
a  micro-crystalline  ^^e  yellow  powder  which 
4ielte  at  175°-178°,  and  is  also  obtained  by  the 
moderated  acetylation  of  anthrapurpurin.  This 
substance  possesses  therapeutic  value.  When 
heated  witn  ammonia,  anthrapurpurin  is  con- 
verted into  anthrapurpurinamide 

CuH,(NH,)(OH),0, 

Anthrapurpurin  has  the  same  affijiity  for 
mordanto  as  alizarin;  the  colours  it  produoes 
are  also  analogous  to  some  extent,  as  it  produces 
reds  with  alumina,  purples  and  blacks  with  iron 
mordanto.  There  is,  nowever,  a  considerable 
difference  in  the  shade  of  colour  produced,  the 
reds  being  much  purer  and  less  blue  than  those 
of  alizarin,  whilst  the  purples  are  bluer  and  the 
blacks  more  intense.  When  usee  in  Turkey-red 
dyeing  it  produoes  very  brilliant  colours  of  a 
scarlet  shade,  which  are  of  remarkable  per- 
manence. 


ALIZARIN  AND  ALLIED  COLOURING  MATTERS. 


133 


ZAieraittre. — Perkin  (Chem.  Soc.  TiaiiB.  25 
669 ;   26,  425 ;    29,  861) ;    Caro  (Ber.  9,  682) 
Sehmiok  and  Romer  (Ber.  9,  679 ;  10, 972, 1823 
13,  42) ;  RcnensUehl  (Bull.  Soo.  ohim.  29,  405) 
Anerbaeh  (J.    1874,  488);     UUmAzm  (Enzyk 
der  Tech.  Chem.  under  Alizarin). 

Pnrpufiii  1:2: 4-Trihydxoz7anthraquinoiie 

CO      ^^ 

I         I  J 


^^Nx>/V 


Purpurin  occurs  along  with  alizarin  in 
madder,  probably  as  a  glucoside.  In  order  to 
separate  it  from  alizarin,  the  mixture  of  the  two 
substances  is  repeatedly  recrystallised  from  a 
hot  solution  of  alum,  in  which  purpurin  is  more 
soluble  than  alizarin,  or  the  mixture  is  dissolved 
in  caustic  soda  and  the  solution  saturated  with 
carbonic  acid.  This  precipitates  the  alizarin, 
but  not  the  purpurin. 

Purpurin  is  obtained  when  alizarin  or 
quinizarin  (1  pt.)  is  heated  with  pyrolusite 
( 1  pt. )  and  concentrated  sulphuric  acid  (8-10  pts. ) 
at  160*.  The  oxidation  of  alizarin  to  purpurin 
is  also  effected  by  the  action  of  ammonium 
persulphate  in  sulphuric  acid  containing  sul- 
phuric anhydride.  o-Aminoalizarin  is  changed 
to  purpurin  by  the  action  of  nitrous  acid  in 
sulphuric  add  solntion,  or  by  the  action  of 
sulphuric  acid  alone  at  160^  Alizarin  yidds 
purpurin  by  the  action  of  sulphuric  acid  at 
225  .  Alizarin  sulphonic  acid  is  oxidised  by 
heating  with  suljphurio  add  and  a  nitrate  to 
purpurin  sulphomo  acid,  and  the  latter  yields 
purpurin  on  neating  under  pressure  with  dilute 
mineral  acids.  Anthraquinone-1 -sulphonic  acid 
if  heated  with  oleum  containing  a  hi^h  per- 
centage of  SO,  is  changed  to  a  sulphuric  ether 
which  is  hydrolysed  by  heating  with  sulphuric 
acid,  and  the  product  is  purpurin- 1 -sulphonic 
acid.  This  dyes  alum  mordanted  wool  in  red 
shades,  and  may  be  converted  into  purpurin. 

Purpurin  crvstalliBes  from  dilute  alcohol  in 
long  orange-ooloured  needles,  which  contain 
1  moL  H^O.  The  pure  substance  begins  to 
sublime  at  160*,  and  melts  at  253*.  It  is 
slightly  soluble  in  water,  forming  a  deep  yellow 
solution ;  in  alkalis  it  dissolves  with  a  purple- 
red  colour ;  in  alkaline  carbonates  with  a  red 
colour.  The  solution  in  alkalis  shows  two 
marked  absorptioit  bands  in  the  green.  Purpurin 
also  dissolves  readily  in  ether,  carbon  disulphide, 
benzene,  and  acetic  acid ;  these  solutions  give 
two  absorption  bands,  one  at  w  and  the  other 
near  ■ ;  the  solution  in  sulphuric  acid  shows 
another  line  in  the  yellow.  When  boiled  with 
acetic  anhydride  it  yields  a  triacetate, 

Ci4H,(C,H,0),0^ 

which  crystallises  in  yellow  needles,  melting  at 
I92*-193*. 

Aqueous  ampaonia  at  150*  converts  purpurin 
into  purpurinamide 

C,H^<;]^]>C,H(NH,XOH),    (OH :  OH :  NH , 

»  1:3:4), 

which,  when  boiled  with  ethyl  nitrite,  vidds 
purpuroxanthin, 

^•^•<Cca!>^«^«<C0H.  (3) 


Purpuroxanthin  is  also  the  product  when 
purpurm  is  reduced  with  either  alkaline  stannous 
chloride  or  sodium  amalgam.  If,  however, 
zinc-dust  be  employed  as  the  reducing  agent  in 
weakly  alkaline,  neutral,  or  acid  solutfon,  then 
the  leuco-  compound  of  quinizarin  is  obtained. 
Purpurin  is  converted  into  2-anilino- 1 : 4- 
dihydroxyanthraquinona  when  heated  with  a 
mixture  of  aniline  and  aniline  hydrochloride. 
A  certain  amount  of  dianilino-hydroxyanthra- 
quinone  is  produced  at  the  same  time. 

Purpunn  dyes  fabrics  much  in  the  same  way 
as  alizarin  and  anthrapurpurin,  there  beins, 
however,  a  difference  in  the  shades.  The  reoiB 
produced  by  purpurin  are  much  yellower,  and 
the  browns  (with  chrome  mordant)  much  more 
intense  than  are  produced  either  by  alizarin  or 
anthrapurpurin. 

The  following  figure  shows  the  absorption 
spectrum  of  a  solution  of  purpurin  in  aluminium 
sulphate : — 

A«    BO 


Alizarin  Blue  Blaek  B,  3B,  0  (Bayer),  is 
obtained  by  the  condensation  of  purpurin  with 
aniline  followed  by  sulphonation  of  the  product. 
The  dye  is  applied  on  a  chromium  moroant. 

Piupurin-S :  8-dJ8ulphoni6  add  is  obtained 
by  heating  the  potassium  salt  of  anthraauinone- 
1  : 6-disulphonic  acid  with  boric  acid  ana  40  p.o. 
oleum  under  6-7  atmos.  pressure.  The  pur- 
purin disulphonic  acid  so  produced  forms  a 
Eotasdum  salt  which  crystallises  from  dilute 
ydrochloric  acid  in  yellow -red  leaflets  whi<:h 
have  a  bronze  lustre.  Heated  at  180°  with  70 
p.o.  sulphuric  acid  the  disulphonic  acid  is  changed 
to  purpurin-B-nUvhonie  acid^  and  in  the  presence 
of  a  mercury  salt  into  purpurin  itself  (Bayer, 
D.  R.  P.  172*688).  The  action  of  alkali  sulphites 
on  purpurin  leads  to  the  production  of  purpurin- 
Z'sulpnonio  acid,  which  may  readily  be  recon- 
verted into  purpurin. 

3-Chloropiir^iiln  is  formed  along  with 
dichhropurpuroxanthin  by  the  action  of  sul- 
phuryl  chloride  on  a  sulphuric  acid  solution 
of  2 : 4-dihydroxybenzoylDenzoic  acid  in  the 
preeence  of  Doric  acid.  It  crystallises  in  deep 
red  needles  melting  at  270*-273*  (Mettler,  Ber. 
45,  800). 

Flavopurpurin.  1  2  :  6-Trihydroxyanthra- 
quinone 

CO      0" 


=°\AcoA^ 


Flavopurpurin  occurs  in  commercial  artificial 
alizarin,  but  is  with  difficulty  isolated  from  this 
product,  owing  to  the  fact  that  its  chemical 
properties  asree  so  closely  with  those  of  anthra- 
purpurin. Which  is  also  nearly  always  present 
in  artificial  alizarin,  that  it  can  only  with  difli- 
culty  be  separated  from  this  substance. 

It  is  prepared  by  fusing  /3-anthraquinonc- 
disulphonio  acid  or  anthraflavic  acid  with 
potadi  or  soda  with  or  without  the  addition  of 
a  nitrate  or  chlorate.  The  details  of  the  technical 
preparation  have  been  discussed  above  under 
A  fArapurpurin. 


134 


ALIZARIN   AND   ALLIED  COLOURINa   MATTERS. 


It  may  be  synthesised  by  the  following  Beriee 
of  reactions : — 

Hemipinic  anhydride  condensee  with  anisole 
in  the  presence  of  anhydrous  aluminium  tri- 
chloride, yielding  the  trimethyl  ether  of  4  : 5  :  6- 
trihydroxybenzoyl  benzoic  acid. 

no      ^Me 
f       1  +  ©<("        Y^\)Me 

AniBoie.  Hanlpinlc  anhydride. 

rrk     OMe 

MeO\y'  HOCO\/ 
TrimethoxybeiuEoylbensoio  acid. 

This  benzophenone  derivative  is  reduced  bv 
zinc-dust  and  concentrated  hydrochloric  acia, 
and  the  product  is  4 :  5  :  6-trimeUioicvdlphenvl- 
methanecarboxylio  acid,  which  is  changed  by 
sulphuric  acid  to  1 :  2  :  6-trimethoxyanthrone. 

.«x       OMe 

MeOl       J      HOOO'       1 

4:6:  ft-tcimetbo^dipbeiiylmetliaaecarbaxylio  add. 

__        OMe 

-^-OC'X)""' 

1:2: 6-triniethozyanthroiie. 

1:2: 0-trimethoxyanthrone  crystallises  from 
benzene  in  small  needles  melting  at  170*.  It  is 
oxidised  by  chromic  acid  in  glacial  acetic  acid 
solution  to  the  trimethyl  ether  of  flavopurpurin, 
which  consists  of  yellow  needles,  crvstalliBes  from 
acetic  acid,  and  melts  at  226*.  The  trimethyl 
ether  is  hydrolysed  to  flavopurourin  by  the  action 
of  aluminium  chloride  at  21(r. 

Flavopurpurin  crystallises  from  alcohol  in 
anhydrous  y«Ilow  needles,  sparingly  soluble  in 
water,  but  readily  soluble  in  cold  aloohoL  Its 
meltinfl-point  lies  above  330*. 

It  aissolves  in  caustic  alkalis  with  a  purple 
colour ;  the  solution  shows  two  absorption  bands, 
one  in  the  blue  and  the  other  near  the  red, 
but  a  little  further  removed  than  the  alizarin 
band. 

Flavopurpurin  dyes  mordanted  fabrics  simi- 
larly to  alizarin,  there  being,  however,  a  slight 
difference  in  the  shades  produced.  The  red 
sbade  is  somewhat  duller  and  yellower;  the 
brown  shade  is  abo  yellower,  flavopurpurin 
dyes  wool  mordanted  with  tin  crystals  and 
cream  of  tartar  a  bright  yellowish  oranse. 

When  heated  with  acetic  anhydride,  fiavo-. 
purpurin  yields  a  triacetate  C^4H,(G.H,0)tO,, 
which  crystallises  from  alcohol  m  golden-yellow 
plates  melting  at  238*. 

Direct  methylation  converts  flavopurpurin 
into  a  dimethyl  ether,  but,  as  in  the  case  of 
alizarin,  a  trimethyl  ether  is  obtained  bv  oxida- 
tion of  the  product  of  methylation  of  deoxy- 
flavopurpurin  (Graebe,  Ber.  38,  162). 

Aliiarin  Rod  8  W.  S.  is  the  sodium  salt  of  the 
monosnlphonic  acid  of  flavopurpuriD. 

AliiariB  Onngt  0«  Nitroflavopurparin. 


.C0> 


OH 


/Y  Y^H 


is  dmilarlv  constituted  to  /3-nitroallzarine.  It 
is  obtained  by  the  nitration  of  flavopurpurin  with 
ordinary  nitric  acid.  Fast  orange  shades  can  be 
produced  by  applying  this  oompound  with  an 
aluminium  mordant. 

On  treatment  with  glycerol  and  sulphurk 
acid  a  trihydroxyanthraquinone  quinolme  of 
the  constitution 


\/\x)AA 


\/ 

is  produced,  the  bisulphite  compound  of  which  is 
the  dyestuflf  Alizarin  Blaek  P. 

It  is  used  for  producing  a  fast  violet  grey  to 
black  in  cotton-printing. 

Literature^—^BTO  (Ber.  9,  682);  Schunck  and 
Romer  (Ber.  9.  679 ;  10,  1823 ;  13,  42) :  Bis- 
trzycki  and  Tssel  de  Schepper  (Ber.  31,  2798). 

AnthragalloU  1:2: 3-Trihydroxyanthraqui- 
none. 

OH 


Anthragallol  does  not  itself  occur  in  nature, 
but  its  three  isomeric  dimethyl  ethers  have  been 
found  in  Chay  root  {Oldenlandia  umbeUaia), 
Anthragallol  ia  formed  when  a  mixture  of 
gallic  acid  (1  pt.),  benzoic  acid  (2  pte.),  and 
sulphuric  acid  (20  pte.)  are  heated  to  126*  for 
eight  hours. 


(y^\ 


Bensoicacld. 


HOCO 


/ 


OH 

A: 


OH 
OH 


GaUicadd. 
OH 


/\y'^\y\oR 


+  2Bfi. 


Anthragallol. 

The  product  is  poured  into  water,  well 
washed,  and  recrystalliaed  from  alcohoL 

It  is  also  obtained  from  1 : 3-dinitTO-2-hydro- 
xyanthraquinone  (the  nitration  product  of  2- 
hydroxyanthraquinone)  by  reduction  in  strongly 
alkaline  solution.  Or  1  :  3-dlamino>2-hy(iro- 
ryanthraquinone  may  be  converted  to  anthra- 
gallol by  heating  with  hydrochloric  acid  under 
pressure. 

Anthragallol  crystallises  in  yellow  needles 
which,  when  heated  to  290*,  sublime  without 
meltinff.  It  is  sparingly  soluble  in  water, 
ohloroK>rm,  or  carbon  disulphide ;  readily  soluble 
in  alcohol,  ether,  or  glacial  acetic  acid. 

It  dissolves  in  alkalis  forming  a  green  solution. 


ALIZARIN   AND  ALLIED  COLOURING  MATTERS. 


135 


Ito  tmceiikte  C^sCC^aO).0.  mdts  »|  17P- 
173*. 


With  uk  exoeM  of  ammonm  anthngallol 
naots,  foiming  anthiBgallolamide^  l-unido- 
%  I  S-diliydiozTMitliimqiiiiMme. 

LilerafMV.— fieubedich  (Bcr.  10,  30). 

By  the  action  of  dimethyl  solf^ate  in  boil- 
ing  nitrobenzene  and  in  presence  of  anhydioas 
■odium  carbonate  anthragallol  yields  the  dtmeOkyi 
etker  which  occurs  in  orange  needles  melting  at 
159''-160°,  and  forms  an  acetyl  derivative 
melting  at  167^.  Concentrated  solphurio  acid 
hydiolyses  this  substance  at  100^  and  forms  a 
monomethyl  ether  melting  at  233^  (acetyl 
derivatiTe,  m.p.  184*^),  whOst  the  action  of  a 
great  excess  of  methyl  sulphate  and  sodium 
carbonate  at  180**  converts  either  the  mono- 
methyl  ether  or  the  dimethyl  ether  into  anthra- 
gaUof  tiimethyl  ether,  wmoh  is  lomon-yellow 
and  melts  at  les""  (Bock,  Monatsh.  23,  (9)  1008). 

Hydiozyaallinriiflii,  1:2: 6-Triliydioiyaii- 
thnmolnoiia.  This  substance  is  readily  obtained 
by  heatinff  anthiarufin  with  a  mizture  of 
sodium  ana  potassium  hydroxides  at  180^-186° 
in  the  presence  of  water  and  sodium  nitrate. 
It  is  aJao  produced  when  alizarin  is  dissolved 
in  70  p.c.  oleum  to  which  boric  acid  has  been 
added,  and  the  mixture  agitated  at  30°-36'' 
until  a  pure  yiolet  solution  has  been  obtained. 
The  sulphuric  ester  so  produced  Is  then  hydro- 
lysed  in  the  usual  manner.  The  two  methods 
combined  determine  the  constitution  of  tlus 
trihydroxyanthraquinone  which  crystallises  from 
acetic  acid  in  red  needles  melting  at  273*^-274^ 
and  forms  a  triacetate  melting  at  227°.  Hy- 
droxyanthrarufin  is  a  valuable  mordant  dyestuff. 

Literature. — ^laebermann  and  Boeok  (Ber.  11, 
1716) ;  liebermann  and  Dehnst  (Ber.  12,  1289) ; 
M.  L.  B.  (D.  B.  PP.  196028  and  196980) ;  By 
(D.  R.  P.  166960) ;  Ziegler  (J.  pr.  Chem.  86, 
297). 

Hydiozyehrysizlii.  1:2: 8-trihydroxyanilm- 
qulnona.  Chiysazin  is  converted  into  this  sub- 
stance by  fusion  with  aqueous  sodium  and 
potassium  hydroxides  in  presence  of  sodium 
nitrate  at  180°.  It  crystallises  in  orange  needles 
melting  at  230°,  and  forms  a  triacetyl  derivative 
melting  at  219°.  The  dimethyl  ether  forms  light 
yellow  needles  melting  at  167°. 

1:4: 8-Trihydroxyanthniqiilnone.  Oxidation 
of  chrysazin  by  means  of  80  p.c.  oleum  and  boric 
acid  at  26°-36°  yields  the  sulphuric  ester  of  this 
isomeride,  and  on  heating  with  ordinary  sul- 
phuric acid  the  substance  is  obtained.  It 
separates  from  pjrridine  in  brown-red  needles 
with  green  metallic  reflex  and  dissolves  in 
aqueous  sodium  hydroxide,  and  cdso  in  sulphuric 
acid  to  a  violet  solution  (By,  D.  R.  P.  161026). 
This  oomjpound  ia  also  obtained  by  the  reduction 
of  Alizarm  Bordeaux. 

1:3: 8-Triliydioxyaatlinu|iil]ione.  The  tri- 
hydroxyantluiu^uinone  obtained  from  rhein 
through  its  amide  and  dihydroxyaminoanthra- 
qninone  (Oesterle,  Arch.  Pharm.  1912,  260,  301) 
is  not  identical  with  hydroxychrysazin,  and 
since  rhein  must  be  either  cfaLrysazin-2-  or  3- 
carboxylio  add,  this  fact  favours  the  latter 
theory.  1:3:  8-Trihydroxyanthraqninone  melts 
at  277°-278%  and  yields  a  triacetyl  derivative 
melting  at  197°-198°. 

1:4:  6-Trlhydrozyanfhraqiiiiione  is  the  chief 
product    when   4-aminophthalic   anhydride    is 


heated  with  quinol  and  concentrated  solphorie 
acid  at  170°-.190°. 

IV.  TMnhydroxyantfanqolnoiMS. 

AnthiaehfliOM      1:3:5;  7-Tbtrahydroxy- 
anthimqninone 

OH 


H0/Y^\/\ 


The  preparation  of  this  body  is  effected  by 
heating  3 : 6-dihydroxybenzoio  acid  with  10 
parts  of  sulphuric  acid  for  3  to  5  hours. 

The  substance  consists  of  silky  yellow  needles 
when  omtaUised  from  alcohol,  or  it  can  be 
sublimed  with  partial  decomposition  in  leaflets. 
It  does  not  melt  at  360*. 

Anthrachrvsone  has  a  very  feeble  affinity  for 
mordants.  Its  tetraacetate  crystallises  in 
yellow  needles  from  aoetio  acid,  and  melts  at 
263<>. 

A  solution  of  anthrachrvsone  in  33  p.o. 
aqueous  sodium  hydroxide  deposits  a  lustrous 
vivid  red  sodium  salt  which  is  converted  into  a 
crystalline  ammonium  salt  by  ammonium 
cmoride.  A  crystalline  potassium  salt  is  also 
known,  and  when  this  ui  heated  with  methyl 
sulphate  at  180°- 190°  it  is  converted  iato  anthra- 
chiysone  dimethyl  ether  which  crystallises 
from  nitrobenzene  in  golden  brown  columns  and 
forms  a  sodium  salt  orvstallising  in  orange-red 
needles.  The  diacetyl  derivative  melts  at  266°. 
The  methvlation  also  results  in  the  production 
of  a  small  proportion  of  anthrachrysone  tetra- 
methyl  ether  ^niich  crystallises  in  golden-yellow 

Srisms  melting  at  294°  (Fischer  and  Ziegler, 
.  pr.  Chem.  1912,  ii.  86,  297).  Anthrachrysone 
condenses  with  secondary  bases,  such  as  diethyl- 
amine,  and  formaldehyde,  with  the  production 
of  tetraalkyldiaminodimethylanthrachrysones. 
The  compound 

^^       OH 


HO 


l^^/^     \^CH^Et, 


NEt.CH.-V\^/Vqp 

is  obtained  from  diethylamine  (M.  L.  B.,D.  R.  P. 
188189). 

Literature. — Hohenemer  (Ber.  36,  2306) ; 
Barth  Senhofer  (Annalen,  164,  109);  Noah 
(Ber.  19,  766). 

1:3:5:  7-Tetraliydrozyaiitluraqtdnon6-2 : 6- 
disulphonle  acid  is  obtained  by  heating  anthra- 
chrysone with  an  excess  of  fuming  sulphuric 
acid  (D.  R.  P.  70803).  It  forms  a  characteristic 
sodium  salt  which  crystallises  in  glistening 
coppery  platelets.  By  the  action  of  chlorine 
it  IS  converted  into  a  dichioro-  derivative,  whilst, 
on  the  other  hand,  sodium  hypochlorite  converts 
the  sodium  salt  into  dichloroanthrachryaone  by 
elimination  of  the  sulphonic  groups.  Dibromo- 
anthrachrysone  lb  obtained  by  bromination  of 
anthrachrysone  in  acetic  acid  solution.  It  melts 
at  above  290°,  and  occurs  in  orange- red  needles. 
The  action  of  bromine  on  a  solution  of  the  disul- 
phonic  acid  in  dilute  acetic  acid  is  to  produce 
tetrabromoanthrachrysone,  dark-red  needles  melt- 
ing above  300^ 

Various  dyestuffs  aie  derived  from  anthra- 
chrysone. 


136 


ALIZARIN  AND  ALLIED  GOLOUBING  MATTERS. 


Dinltroanthraebrysonedlsulphonie  aeld 


.00. 


NO,     ^ 
HO/\|/^\/\SO,H 


^OH 


if  prepared  by  sulphonation,  followed  by  nitra- 
tion of  anthraohryaone. 

It  is  a  fast  brown  wool  dye. 

On  reduction  it  yields  diaminoanthraohry- 
Bonedisulphonic  aoid,  which  dyes  wool  yiolet 
from  an  acid-bath,  or  blue  on  a  chromium  mor- 
dant. 

If,  however,  the  reduction  is  carried  out  in 
alkaline  solution  with  sodium  sulphide,  then  tho 
dyestuff  Add  Alisarln  Green  B  and  0  results. 

The  constitution  of  this  product  is 
SH      ^       OH 


HO/  \X       \/  XSO,Na 


OH 


SH 


It  dyes  chromed  wool  a  fast,  pure  green. 
AeU  AUarin  Blue  BB  and  OR 

OH      nr.       OH 


is  obtained  by  boiling  diaminoanthrachrysone- 
disulphonic  acid  with  alkali.  A  red  shade  is 
prodnoed  on  wool  &om  an  acid-bath,  which  on 
chromii^  develops  a  beantiful  blue,  exceedingly 
fast  to  light  millmg,  acids  or  alkalis. 

8-Mttro-4-aniUno-l  :^  :  6  :  7-t6trabydroxy- 
anttiraqiiinone-2 : 6-dlsiilphonIe  add  is  obtained 
in  the  form  of  its  trisodium  salt  (dark  bluish- 
violet  crystals  with  coppery  lustre)  by  heating 
a  solution  of  4  :  S-dinitro-l :  3  : 5  :  7-tetrahy- 
dit>zyanthraquinone-2  :  6-disulphonic  acid  m 
aqueous  sodium  carbonate  with  aniline.  A 
similar  replacement  of  the  nitrozyl  by  anilino 
occurs  with  the  unsulphonated  dinitro-  com- 
pound (Hellev  and  Skraup,  Ber.  46,  2703; 
D.  B.  P.  71964). 

Rufloiilnt  1:2:6:  6-T6tnliydroxyantlira- 
qulnons. 

This  tetrahydrozyanthraqninone  is  obtained 
by  heating  opianic  or  hemipinic  acids  with 
sulphuric  add  at  180°. 

Also  by  fusing  the  disulphonic  acid  of  anthra- 
rufin  with  potash. 

It  forms  a  reddish-yellow  crust  from  ether, 
and  can  be  sublimed  in  oran^  needles. 

It  gives  a  viblet-red  solution  in  dilute  alkaUs 
or  in  sulphuric  acid.  A  curious  poperty  of 
rufiopin  is  its  stability  towards  fusion  with 
potash. 

The  substance  is  of  no  value  as  a  dyestuff, 
since  it  gives  only  dull-brown  shades  with 
mordants. 

Literature. — Liebermann  and  Chojnacki 
(Annalen.  162,  323) ;  D.  R.  P.  103988. 

a-  and  /i-HydroxyanthragaUois. 

A  mixture  of  these  substances  is  produced 
when  equimolecular  proportions  of  gallic  and 
m-hydrozybeDsoic  acids  are  heated  at  150°, 
with  10  parts  of  sulphuric  acid  for  twenty 
hours. 


The  product  is  poured  into  water  and  the 
dried  precipitate  extracted  with  alcohol.  This 
extract  is  evaporated  and  the  residue  treated 
with  hot  benzene.  The  a-  compound  passes  into 
solution,  whilst  the  fi-  remains  undissolved. 

a-Hydroxyanthragallol  .crystallises  from 
alcohol  in  golden  yellow  micro-  needles.  It 
forms  a  green  solution  in  alkalis,  whilst  that  in 
sulphuric  add  is  vi<Jet,  and  diows  two  absorp- 
tion bands  between  f  and  d.  With  mordants 
it  behaves  similarly  to  rufigallic  acid. 

Its  tetraacetyl  derivative  melts  at  207''- 
209^ 

iS-Hydroxyanthragallol  czTstallises  from 
alcohol  and  occurs  in  red  need^.  Its  brown- 
red  solution  in  sulphuric  add  shows  two  absorp- 
tion bands  between  e  and  H. 

The  tetra-acetate  czystallises  from  gladal 
acetic  acid  in  lemon-ydlow  tables  of  m.p. 
189^ 

Literature.— Noah  (Annalen,  241,  270). 

1:2:3:  4-T0tn]iydroxyanUiraqiiinone  is 
obtcuned  by  heating  anthragallol  with  sulphuric 
add  in  the  presence  of  boric  add  at  200^240^ 
It  consists  of  green  needles  soluble  in  both 
alkalis  and  sulphuric  add  with  red  colour. 
The  tetraacetyl  derivative  melts  at  205"". 

Z/iYara^ttre.— Bayer  and  Co.  D.  R.  P.  86968. 

Alizarin  bordeaux  (Quinalizarin).  1:2:5:8- 
Totrahydrozyanthraquinone 

OH     x».      OH 


OH 

Alizarin  bordeaux  is  by  far  the  most  impor- 
tant of  the  tetrahydroxyanthraquinones. 

It  has  been  obtained  by  the  hydrolysis  of  its 
dimethyl  ether  (see  below)  with  a  solution  of 
hydrochloric  acid  in  acetic  acid  at  200^. 

It  is  prepared  by  heating  alizarin  (1  pt.)  with 
sulphuric  acid  (10  pts.  containing  80  p.c.  SO,) 
for  four  da^  at  26^-^60^.  This  yidds  tho 
sulphuric  acid  ester  of  alizarin  bordeaux,  to 
obtain  which  the  reaction  product  is  rendered 
alkaline  and  then  boiled  with  an  excess  of 
hydrochloric  acid. 

It  is  found  that  the  oxidation  of  alizarin 
occurs  more  readily  in  presence  of  boric  add. 

Alizarin  bordeaux  can  be  obtained  in  deep 
red  needles  with  green  metallic  reflecton. 

On  an  aluminium  mordant  it  produces 
bordeaux  shades ;  violet  blue  on  chromium. 

The  tetraacetate  crvstallises  from  chloroform- 
alcohol  in  micro-  needles  of  m.p.  201°. 

Dhnethyl  ether. 

This  substance  is  synthesised  bv  heatins 
hemipinic  acid  and  quinol  with  sulphuric  acid 
to  130^ 

The  brown-red  micro  leaflets  obtained  by 
crystallisation  from  benzene  mdt  at  225^-280°. 

I.t(eni<icf«.— Schmidt  (J.  pr.  CheotL  [2]  43, 
239);  Liebermann  and  Wense  (Annalen,  240, 
299). 

Aliiarln  Green  S  (B). 

Alizarin  blue  can  be  oxidised  by  means  of 
sulphur  trioxide,  and  the  product  on  treatment 
with  sulphuric  acid  gives  a  dihydroxy alizarin 
blue  of  tne  probable  constitution 


ALIZARIN  AND  ALLIED  COLOURING  MATTERS. 


137 


OH     f^      OH 

/\y^\/\OB. 

II  II 


CH 


la 


I  to  that  by  wliioh  puxpuxin  ia  prodaoed  £rom 
I  alizarin.    The  aubstanoe  orvstaltises  in  bronse- 

ooloured  leaflets  from  nitrobensene.      The  blue 

■olution  in  concentrated  Bolphurio  acid  exhibits 

red  fluorescence. 

Alizarin  cyanine  R.  yields  a  handsome  blue 

ohxomium  lake. 


V 


Alizarin  Green  S  (B)  is  the  bisulphite  com- 
pound of  this  tetrahydroxyanthraquinone 
quinoline.  It  dyes  very  fast  bluish-greens  on 
chromed  wool. 

1:4:6:  S-TetrahydroxyBnthraqulnoDt 


This  substance  has  been  obtained  by  the 
action  of  sulphuric  acid  on  j)p-dinitroanthra- 
rufin  (By,  D.  B.  PP.  126679,  162033),  but  the 
following  method  establishes  the  constitution  of 
the  substance : — 

6 : 8-Dichloroquinizarin  is  heated  for  20 
hours  at  250°  with  milk  of  lime  and  copper. 
The  product  is  acidified  with  hydrochloric  acid, 
and  the  substance  may  then  oe  collected  and 
crystallised  from  a  inixture  of  benzene  and 
li^oin.  The  brown  needles  melt  at  246°,  and 
dissolve  in  alkaline  solutions  with  a  oomflower- 
blue  colouration.  The  sulphuric  acid  solution 
exhibits  two  bands  in  the  red  and  yellow 
resMctavely. 

it  is  interesting  that  this  tetrahydroxy- 
anthraquinone has  powerful  mordant  dyestuff 
properties  (Frey,  Ber.  46,  1361). 

The  tetraacetyl  derivative  forms  light  yellow 
needles  melting  at  260°  with  decomposition,  and 
the  difficultly  soluble  blue  potassium  sait  is 
converted  by  methyl  sulphate  at  180°  into  a 
tetramethyl  ether,  which  crystallises  in  lustrous 
orange  leafleta  and  melts  at  317°  (Fischer  and 
Zeigter,  J.  pr.  Ghem.  1012,  ii.  86,  297). 

IMliydroxyehrysazlns.  Two  isomeric  tetra- 
hydroxyanthraquinones  have  been  obtained 
from  chrysazin.  The  first  (Schrubsdorff,  Ber. 
36,  2936)  by  fusion  of  chrysazin  with  potassium 
hydroxide.  This  isomeride  sublimes  in  vacuot 
forms  dark-red  needles  melting  at  217°,  and 
intensely  colours  ordinary  mordants.  Its  acetat3 
melts  at  196°.  The  second  compound  (Wobiing, 
Ber.  36,  2941)  is  obtained  by  fusing  chrysazin 
disulphonio  acid  with  alkau.  This  melts  at 
292°,  and  also  colours  mordants.  Its  tetra- 
acetyl derivative  melts  at  233°. 

V.  Pentahydroxyanfhnuiuinones. 

Alixarin  eyanine  R.  1:2:4:6: 8-Penta- 
hydroxyanthniquinone 


AUiarin  Indigo  Blue  8. 


OH    ^^     OH 

ho/Y^''Y>oh 


CH 


V 


is  the  bisulphite  compound  of  the  pentahydroxy- 
anthnu|uinone  quinoline,  obtained  by  the  further 
oxidation  of  alizarin  Green  S  (B)  with  con- 
centntted  sulphuric  acid  at  200°.  It  yields 
fast  indigo- blue  shades  on  crome  mordanted 
wool. 

DihydroxyanthragalloL  1:2:3:6: 7-Penta- 
hydroxy  antluaquinone 

HO/\^^\/\OH 

Equimolecular  amounts  of  gallic  acid  and  3  :  6- 
dihydroxy benzoic  acid  are  neated  to  160*  for 
ten  minutes  with  ten  times  their  weight  of 
sulphuric  acid.  The  product  contains  dihydroxy- 
anthragallol,  rufigallic  acid,  and  anthrachrvsono. 
In  order  to  separate  them,  advantage  is  taken  of 
the  fact  that  only  dihydroxyanthragallol  penta- 
acetate  is  soluble  in  alcohol.  The  acetate  so 
obtained  is  hydrolysed  with  cold  sulphuric  acid. 

Dihydroxyanthragallol  crystallises  from  al- 
cohol in  smaU  red  needles,  which  do  not  melt  at 
360°.  The  substance  is  similar  in  tinctorial 
properties  to  rufigallic  acid. 

The  pentaacetate  melts  at  229°. 

LitercUure. — ^Noah  (Annalen,  241,  276). 

VI.  Hexahydroxyanthraqiiiiiones.  Rufigallol. 
Rufigallic  acid,  1:2:3:6:6:  7-Hexahy(&oxy- 
anthraquinone 


HO 


CO 


OH 
\0H 


'"'^S.^^co/N/^^ 


This  valuable  substance  is  obtained  by  the 
oxidation  of  alizarin  bordeaux  with  pyrolusite 
in  sulphuric  acid  solution.  The  sulphonic  acid 
ether  so  produced  is  hydrolysed  by  boiline  with 
dilute  acid.    This  oxidation  is  entirely  analogous 


OH 

Rufigallic  acid  is  produced  when  gallic  acid 
is  heat^  with  concentrated  sulphuric  acid  at 
140*.  It  may  be  sublimed  in  yellow  needles. 
A  violet  solution  is  obtained  with  alkalis,  red 
with  sulphuric  acid.  Bar3rta  produces  a  blue 
insoluble  precipitate.  Alizarin  is  obtained  by 
the  reduction  of  rufigallic  acid  with  sodium 
amalgam.  The  substance  is  a  good  Qxample  of 
a  polygenetic  dyestufl,and  yields  with  aluminium, 
iron,  and  chromium  mordants,  red,  violet,  and 
brown  respectively.  The  colours  are,  however, 
not  pure  in  tone. 

Anthracene  Blue.  1:2:4:6:6: 8-hexa- 
hydroxyanthraquinone 


138 


ALIZARIN  AND  ALLIED  COLOURING  MATTERS. 


OH 


OH 


\/\0H 


Anthiaoene  blue  is  an  important  dyectuff,  and 
can  be  obtained  from  erytbrozyanthraquinone, 
anthiarufin,  or  antbraohnraone,  by  tbe  oxidising 
action  of  sulpbor  triozide  in  snlpborio  acid  in 
thepreeenoe  of  boric  acid. 

it  IS  best  prepared  by  the  action  of  40  p.c. 
oleum  with  or  without  the  addition  of  sulpnur 
on  1 : 6-dinitroanthraquinoney  and  treatment 
of  the  product  with  ordinary  sulphurio  add. 

The  solution  in  ooncentratea  sulphuric  add 
is  violet- blue  and  shows  a  brown  nuorescenoe. 
The  aluminium  lake  is  violet  and  the  chromium 
lake  blue. 

Its  disulphonic  add  is  Add  alizarin  blue  6  B, 
mentioned  above,  and  prepared  from  anthra- 
ohrysone. 

Btnioin  Yeltow 


Ph 

I 


■o 


\A„„/V" 


is  prepared  by  the  condensation  of  benzoin  with 
gallic  acid  under  the  influence  of  sulphuric 
acid. 

It  dyes  wool  on  a  chromium  mordant  a  fast 
yellow  (except  to  light). 

Gallelii  GtoH^O, 

^      OH  OH 

II  I        ' 


C 

I 


Q 


OOH 


Gall^bi  is  formed  by  heating  pyrogallol  with 
phthalic  anhydride. 

Prepar(Uum.^^A  mixture  of  1  part  of  phthalio 
anhydride  and  2  parts  of  pyrogallol  are  heated  to 
190^-200^  tlie  product  dissolved  in  alcohol,  and 
the  colouring  matter  precipitated  by  the  addi- 
tion of  water.  The  crude  gallein  thus  obtained 
is  dissolved  in  alcohol,  reprecipitated  with  water, 
and,  after  repeating  this  operation  a  few  times, 
converted  into  the  acetate  by  heating  with 
acetic  anhydride.  This  is  recrystallised  seTcral 
times,  and  decomposed  with  potash. 

Gallein  crystallises  from  alcohol  in  small 
greenish  crystals.  It  Is  insoluble  in  chloroform 
and  benzene,  sparingly  soluble  in  water  and 
ether,  readily  soluble  m  alcohol,  forming  a  dark- 
red  solution.  It  dissolves  in  cold  concentrated 
sulphuric  acid  without  change ;  on  warming  the 
solution  coerulein  ia  formed. 

Gallein  dissolves  in  small  quantities  of  potash 
or  soda  with  a  red  colour ;  excess  of  alkali  pro- 
duces a  blue  solution.  Heated  to  160*  with 
acetic  anhydride  gallein  yields  a  tetracetate  of 
hydrogallein. 


Gallein  (often*  called  anthracene  violet)  is 
sold  in  the  form  of  a  reddish-brown  powder,  or 
a  10  p.o.  paste ;  not  vray  soluble  in  cold  water, 
but  readily  so  in  hot.  With  all  the  usual  aliza- 
rin mordants  gallein  produces  purple  ooloura, 
which  are  fast  to  li^ht  and  soap ;  those  obtained 
by  the  use  of  chromium  and  iron  are  bluish,  those 
with  tin  reddish,  those  with  aluminium  inter- 
mediate in  tone. 

Literohirs.— Baeyer  (Ber.  4,  467  and  063) ; 
Buchka  (Annalen,  209,  261);  Omdorff  and 
Brewer  (Amer.  Clism.  J.  1001,  97). 

CiBruleln  C|oH,oOa 

0       OH      o       OH 


Coerulein  is  prepared  by  heating  1  part  of 
gallein  and  20  parts  of  sulphuric  acid  to  200*, 
and  precipitating  the  colourmg  matter  by  adding 
a  lai^  quantity  of  water.  U  is  thus  obtained 
as  a  bluish-black  mass,  which,  when  rubbed, 
acquires  a  metallic  appearance.  It  is  almost  in- 
soluble in  water,  ether,  and  alcohol,  more  readily 
soluble  in  acetic  acid. 

It  dissolves  in  alkalis  with  a  green  colour,  in 
adds  with  an  olive-brown  colour.  With  bisul- 
phite of  soda  coerulein  forms  an  easily  soluble 
compound.  With  acetic  anhydride  it  forms  a 
triacetate.  Gceruleln  (anthracene  green)  is  sold 
in  two  forms,  either  as  a  bluish-black  paste  con- 
taining 10-20  p.c.  coerulein,  or  as  a  black  powder. 

The  former  is  insoluble  in  water,  the  latter, 
known  as  coerulHn  S,  is  soluble  in  water,  and  is 
indeed  a  bisulphite  compound  of  coerulein. 

Coerulein  is  mostly  employed  m  cidico-print- 
ing  for  producing  very  fast  olive-green  shades, 
miatever  the  mordant  used,  only  different 
shades  of  olive-neen  are  produced. 

Ltterottffe.— %aever  (Ber.  4^  666,  663) ;  Om- 
dorff  and  Brewer  (Amer.  Chem.  J.  1001,  97). 

F.  H.  G.,  W.  ^.  P.  and  R.  R. 

ALIZARIN  (Natural)  v.  Chat  soot  and 
Madder. 

ALIZARIN  AND  METHYL  ETHER  v.  Chay 

BOOT. 

ALIZARIN  BLACK,  -BLUE,  -BORDEAUX* 
BROWN,  -CARDINAL,  -CYANINE,  -GARNET, 
GREENS,  -MAROON,  ORANGE,  -REDS,  -SA- 
PHIROL  V,  Alizarin  and  aujed  coLOURiNa 

MATTERS. 

ALIZARIN  YELLOW  v.  Azo-  coloubino 
MATTERS ;  Ketones. 

ALKALI  ALBUMIN  v.  Proteins. 

ALKAU  BLUE.  Nichotaon's  blue.  Sodium 
triphenyl-roaaniline    aulphonaie    (v.   Tbifhsnti« 

METHirNB  COLOUBINO  MATTERS). 

ALKAU  BROWNS,  -YELLOW  v.  Azo-  co- 
louring MATTERS. 

ALKALIMETRY  v,  Acidimetry. 

ALKALI  WASTE  v.  Soda  manufacture,  art. 
Sodium. 

ALKALOIDS.    The    alkaloids    are    nitro- 
genous   basic    carbon    compounds    occurring 
mostly  in  plants,  but  a  few  animals,  e.^.  the 


ALKALOIDa 


13d 


Bai&mander,  contain  baaee  similar  in  every 
respect  to  the  typical  Yeffotable  alkaloids.  The 
exact  demarcation  of  we  group  is  difficult; 
generally  the  alkaloids  may  be  said  to  contain 
heterocyclic  nitrogen,  to  be  soluble  in  solvents 
immiscible  with  water  and  to  have  a  complicated 
moleeular  structure.  These  characters  are,  as 
a  role,  not  possessed  by  the  simpler  amines  and 
betainee  derived  from  the  amino-  acids  of  pro- 
teins, nor  by  choline  and  other  bases  of  seneral 
biological  importance,  which,  in  contraoistinc- 
iion  to  the  typical  alkaloids,  are  not  limited  to 
one,  or  a  few,  species  of  plants  or  animals.  For 
a  full  account  (tt  these  amines,  betaines,  choline, 
&a,  V.  Barger,  The  Simpler  Natural  Bases, 
Longmans,  1914.  A  list  of  books  dealing  with 
alkaloids  is  given  at  the  end  of  this  article. 
.  The  discovery  of  the  first  alkaloid  is  due  to 
the  Gorman  pharmacist  Sertumer,  who,  in  1805, 
isolated  from  opium  a  substance  *  morphium,' 
which  he  described  more  fully  in  1817  as  a  basic, 
salt-formmg  substance  having  the  principal 
physioloffical  action  of  the  druff.  The  discovery 
of  morpnine  was  quickly  folfowed  bv  that  of 
other  alkaloids,  made  chiefly  by  Pelletter  and 
Caventou.  The  first  volatile  alkaloid,  conilne, 
was  isolated  in  1827  by  Giesecke,  and  nicotine 
in  1828  by  Poeselt  and  Riemann. 

Distribatioii  and  mode  of  fonnation.  No 
alludoids  have  been  obtuned  from  alsse  and 
moosee,  hardly  any  from  fungi,  a  few  omy  from 
Taaoolar  oryptc^ams  and  gynmosperms,  more 
from  monocotvfedons,  but  the  vast  majority 
from  diootyledons.  Certain  laige  orders,  eg. 
ComposiUB  OratninecBf  are  very  poor  in  alkaloids, 
others  such  as  the  RanunculacecB,  8olanace(B, 
Pitpaveracea  are  typically  rich.  Generally  an 
alkaloid  is  limited  to  a  single  genus  or  order ; 
berberine,  however,  occurs  in  several  orders. 
The  total  alkaloids  of  a  plant  usually  consist  of 
a  mixture  of  several  bases  often  closely  related, 
which  may  be  present  in  very  different  amounts. 

The  older  view  that  aikiloids  are  plastic 
materials  capable  of  further  utilisation  by  plants 
has  been  disproved  by  Clautriau  (Ann.  Soc. 
beige  de  Mioroso.  1894,  18 ;  Ann.  Soc.  roy.  Sci. 
m^  nat.  Bruxelles,  1900,  9),  who  concludes 
that  they  are  waste  products,  only  of  use  as  a 
means  oi  defence  on  account  of  their  poisonous 
propertiee.  The  amount  of  alkaloid  is  generally 
greatest  in  the  mature  plant  and  in  the  periphery 
(bark)  or  in  hibernating  parts  (root) ;  it  varies 
greatly  in  different  organs.  Weight  for  weight 
young  shoots  and  leaves  may  contain  more 
than  older  ones.  For  methods  of  microscopical 
localisation,  see  Errera,  Maistriau,  and  Clautriau 
(Ann.  Soc.  beige  de  microsc.  1888, 12 ;  Clautriau, 
ibid,  1894, 18). 

The  mode  of  origin  of  alkaloids  in  plants 
is  not  understood  and  has  given  rise  to  much 
speculation  (Czapek,  Biochemie  der  Pflanzent 
1905,  ii.  267  ;  Windaus  and  Knoop,  Beitr.  chem. 
Physiol.  Path.  1905,  6,  392 ;  Pictet,  Arch.  Sci. 
phys.  nat.  1906,  243,  329;  1906,  244,  389; 
Tunmann,  Arch.  Pharm.  1910,  248,  644; 
Winterstein  und  Trier,  Die  Alkaloide,  1910, 263).; 
The  most  fruitful  contribution  is  probably  that 
of  Robinson  (Trans.  Chem.  Soc.  1917,  111,  876), 
who  utilises  only  reactions  which  can  be  carried 
out  in  the  laboratory  at  the  ordinazy  temperature 
and  shows  how  several  of  the  principal  alkaloids 
might  be  built  up  from  ammonia,  formaldehyde. 


ormthine,  lysine,  and  degradation  products  of 
carbohydrates,  such  as  citric  and  acetonedi- 
oarboxylic  acids.  These  substances  are  imagined 
to  undergo  aldol  and  similar  condensations,  and 
it  is  interesting  to  note  that  Robinson  has 
actually  synthesised  tropinone  in  aqueous 
solution  at  room  temperature  from  succindi- 
aldehyde,  methylamine,  and  calcium  acetone- 
dicarboxylate. 

The  alkaloids  may  be  classified  cheoiically 
according  to  the  heterocyclic  rings  in  which  nitro- 
gen occurs,  as  derivatives  of  pyrrolidine  {e.g. 
hygrine),  of  pyridine  {e.g,  arecoline),  of  piperidino 
(e.ff.  piperine),  of  glyoxaline  {e,g,  pilocarpine),  of 
indole  (e.^.  physostigmino),  of  quinoline  (e,g, 
quinine),  and  of  Moquinollne  {e,g.  papaverine) ; 
another  f^roup  contains  alkaloids  without 
heterooycUc  ring,  deriyatives  of  aliphatic  amines 
{e.g.  narceine).  Some  alkaloids  may  be  dassified 
under  two  of  the  above  or  under  additional 
groups ;  thus  atropine  and  cocaine  contain  both 
a  pyrrolidine  and  a  piperidine  ring,  caffeine 
contains  a  pyrimidine  ring  in  addition  to  glyoxa- 
line. No  chemical  classification  can  be  complete, 
and  a  large  number  of  alkaloids  of  insufficientiy 
known  constitution  have  perforce  to  be  arranged 
according  to  the  plants  (or  animals)  from  which 
they  are  derived. 

Method  of  oztntetion  aind  isolation.  Generally 
speaking,  alkaloids,  whether  occurring  in  the 
free  state  or  as  salts  of  organic  acids,  are 
extracted  from  the  finely  powdered  material 
by  means  of  strong  spirit.  After  distilling  off 
the  alcohol,  the  bases  are  extracted .  from  the 
residue  by  dilute  acids,  liberated  by  the  addition 
of  ammonia  or  sodium  carbonate  and  extracted 
by  chloroform,  ether,  or  carbon  tetrachloride. 
This  gives  the  total  alkaloidal  content  of  the 
plant,  except  where  a  quaternary  base  is 
present,  when  methods  similar  to  those  em- 
ployed for  the  simpler  natural  bases,  e.g.  pre- 
cipitation with  mercuric  chloride  or  phospho- 
tungstic  acid,  are  utilised.  Certain  stable 
alkaloids  may  be  extracted  from  a  mixture  of 
the  finely  powdered  plant  with  lime  or  magnesia 
by  an  organic  solvent;  in  other  cases  {e.g. 
caffeine  in  tea)  extractions  with  boiling  water 
may  be  employed. 

The  *  total  alkaloids  *  of  plants  obtained  by 
the  above  methods  are  mixtures  for  which  no 

General  method  of  separation  can  be  given, 
n  some  cases,  caustic  soda  may  be  used  to 
separate  the  phenolic  from  the  non-phenolic 
bases ;  in  others,  fractional  extraction  of  the 
ether  or  chloroform  solution  of  the  bsises  with 
acid  brings  about  a  separation;  or,  again,  a 
fractionation  ma^r  be  effected  by  regenerating 
the  bases  from  acid  solution  by  an  alxali  in  the 
presence  of  light  petroleum  or  ether,  in  which 
only  a  part  of  the  mixture  is  soluble.  After 
suitable  preliminary  treatment  on  these  lines, 
alkaloids  often  crystallise  as  the  free  base,  but 
if  not,  it  is  generally  possible  to  crystallise  a 
salt  with  a  strong  or  weak  acid.  A  convenient 
method  is  to  add  to  the  dry  ethereal  solution  of 
the  alkaloid,  contained  m  a  tall  stoppered 
cylinder,  small  amounts  of  an  ethereal  or  con- 
centrated alcoholic  solution  of  the  acid,  until 
no  more  alkaloidal  salt  is  precipitated,  shakiiu; 
after  each  addition.  If  excess  oi  acid  is  avoidea, 
the  flocculent  precipitate  can  be  readily  washed 
by  decantation  and  is  then  crystallised  from 


140 


ALEALOlDa 


alcohol,  with  (mF  without  ether.  The  choice  of 
the  proper  acid  is  sometimes  of  great  importance, 
e.^.  for  physostigmine  th§  salicylate  is  the  best 
salt,  and  for  eigotoxine  the  phosphate.  Add 
oxalates  are  fr^uently  valtiable,  whilst  anri- 
chlorides  are  asefal  for  Solanaceoiis  alkaloids  and 
pioratee  for  simple  bases,  but  no  general  rule 
can  be  eiyen.  For  further  information  con- 
oeminff  the  methods  of  separating  and  oharaoter- 
isinff  ukaloids,  see  Allen  s  Commercial  Organic 
Analysis,  vol.  yi.  1912, 171-177,  and  the  articles 
in  tms  dictionary  on  Genohona,  Ifeoaouakba, 
and  Opium  alxaix)Ids. 

Phydeal  and  ehflmiAal  tban/skn  of  the 
alkaloldf  •  Nearly  all  are  solids,  and  then  mosUy 
crystalline ;  a  few  (oonHne,  nicotine)  are  liquids, 
and  are  yolatile  with  steam.  Jn  a  high  vacuum 
even  complex  alkaloids  may  often  be  sublimed 
or  distillad  on  a  small  scale,  e.g.  strychnine. 
Most  alkaloids  are  optically  active ;  the  apecific 
rotation  of  the  free  Mse  in  a  dissociating  solvent 
may  differ  considerably  from  that  of  the  ion  of 
a  salt  in  the  same  solvent,  and  the  two  may 
even  have  opposite  signs  {e,g,  nicotine  and  its 
salts)  (c/.  Carr  and  Reynolds,  Chem.  Soc.  Trans. 
1910,  97,  1328). 

The  majority  of  the  typical  alkaloids  are 
insoluble,  or  very  sparin^lv  soluble,  in  water; 
their  best  solvent  is  alcohol.  Usually  they  are 
also  dissolved  by  chloroform,  less  generalfy  by 
ether,  benzene,  or  amyl  alcohol,  sometimes  by 
light    petroleum.    Simple     amines,     betaines, 

E urine  derivatives,  and 'quaternary  alkaloids 
ke  columbamine,  are  often  more  soluble  in 
water  than  in  organic  solvents.  The  aqueous 
solutions  of  the  alkaloids  are  often  strongly 
alkaline  to  litmus,  but  a  few  alkaloids  which  are 
acid  amides  (colchicine,  caffeine,  piperine)  are 
so  feebly  basic  that  they  may  be  extracted  from 
acid  solution  by  chloroform,  owing  to  the 
extensive  hydrofysis  of  their  saJts.  In  these 
cases  the  salts  are  mostly  not  obtainable  in  a 
pure  orvstalline  condition.  Alkaloidal  salts  are 
generally  more  or  less  readily  soluble  in  water 
and  in  alcohol,  but  as  a  rule  not  in  chloroform 
or  ether.  Salts  of  the  more  complex  alkaloids 
may  be  very  little  soluble  in  excess  of  the  acid, 
if  the  latter  is  hi|B;hly  dissociated  (mineral  acids 
or  even  oxalic  add). 

The  vast  majority  of  alkaloids  are  tertiary 
bases.  A  few  (carpaine,  cytiaine,  ephedrine) 
are  secondary  bases;  the  betaines,  berberine, 
columbamine,  &c.,  are  quaternary.  Primary 
baties  are  only  found  among  amines  derived 
from  the  amino-  adds  of  protein  and  not  among 
true  alkaloids ;  they  seem  to  be  formed  only  by 
bacteria  and  ianoL 

Moot  of  the  lukalolds  are  monadd  bases  even 
when  they  contain  several  atoms  of  nitrogen  in 
the  molecule.  Thus,  pilocarpine  with  two, 
physostigmine  with  three,  and  eigotoxine  with 
five  nitrogen  atoms  are  monadd  bases.  Quinine 
is  the  best  known  example  of  a  efi-add  alkaloid. 
Certain  alkaloids  or  their  salts  can  be  hy drogen- 
ated  in  aqueous  solution  or  suspension  bv  means 
of  molecular  hydrogen  in  presence  oi  nickd 
suboxide,  or  a  colloidal  metal  of  the  platinum 
group,  at  the  normal  temperature  and  pressure 
or  at  increased  pressures.  Thus  quinine  hydro- 
chloride yields  hydroquinine,  morphine  yields 
dihydromorphine,  and  codeine  yields  dibydro- 
codeine,   whilst  cinnamylcocaine  gives  hydro- 


dnnamylcocaine,  an  oily  liquid  decomposed  by 
heat.  Strychnine  and  orudne  yield  me  corre- 
spondins  dihydrides,  and  colchicine  gives  the 
tetrah^aro-  derivative.  The  redaction  of  these 
alkaloids  may  also  be  effected  by  nascent 
hydrogen  liberated  from  formic  aoid  by  the 
action  of  finely  divided  metals  of  the  platinum 
group  (HGOOH<=Ha+COs).  Quinine,  morphine, 
oodeme,  and  other  opium  alkaloids  may  be 
converted  int«  dihydxo-  derivatives  (Eng.  Pat. 
10204,  1913 ;  14247,  1913  ;  D.  B.  PP7306939 ; 
230724 ;  260233 ;  U.S.  Pat.  989604 ;  Eng.  Pat. 
3948, 1912). 

General  alkaloidal  preelpitanti.  AuHc 
chhride  AuCS,  combines  with  alkaloidal  hydro- 
chlorides to  form  well-defined  aurichlorides  of 
the  compodtion  B,HAuGl4,  generally  sparingly 
soluble  m  water,  and  obtained  as  pale-yelfew 
predpitates  on  mizinff  the  gold  and  alkaloidal 
chlondes  in  aqueous  B<Mution.  The  aurichlorides 
may  be  recrystallised  from  alcohol  or  water 
acidulated  with  hydrochloric  add,  and  are  most 
useful  for  characterising  Solanaoeous  alkaloids. 
Occasionally  gold  chloride  is  reduced  to  metallic 
gold  with  formation  of  a  red  gold  sol.  The 
aurichlorides  may  be  analysed  by  simple  ignition, 
or  by  combustion,  or  by  decompoution  with 
hydrogen  sulphide ;  in  the  last  case  the  alkaloid 
is  recovered  unchem^ed  bv  making  the  filtrate 
from  the  gold  sulphide  alkaline  and  extracting 
with  chloroform.  In  a  few  cases,  when  alcoholic 
solutions  of  gold  chloride  and  of  the  alkaloid 
are  mixed,  stable  crystalline  salts  (auric  chloride 
compounds)  of  the  composition  B,AuCls  are 
obtamed  (Dunstan  and  Ince,  Chem.  Soc.  Trans. 
1891,  59,  271).  Por  other  aurichloride  com- 
pounds of  abnormcd  compodtion,  »ee  Dunstan 
and  collaborators  (Chem.  Soc.  Trans.  1893,  63, 
201,446;   1900,77,57). 

Platinic  chloride  in  aqueous  solution  may 
precipitate  platinichlorides  of  the  compodtion 
Ba,H!,PtClt,  which  are  generally  more  soluble 
than  the  aurichlorides  and  are  analysed  jn  the 
same  way.  In  both  cases  the  estimation  of  the 
chlorine  may  be  useful. 

Picric  acid  precipitates  the  solutions  of  most 
alkaloidal  salts,  ana  the  resulting  picrates  may 
often  be  civstallised  (from  water  or  alcohol). 
The  alkaloid  may  be  recovered  by  extracting  it 
from  alkaline  solution  by  chloroform,  or  the 
picric  add  may  be  removed  from  acid  solution 
by  wliAlring  with  ether  or  benzene.  The  picrio 
add  is  conveniently  estimated  without  the  loss 
of  the  alkaloid,  by  nitron  (Busch,  Ber.  1905, 
38,  861). 

Pierolonic  acid  (4-nitro•l-]^nitrophenyl-3- 
methyl-5-pyrazolone)  in  alcoholic  solution 
behaves  dmilarly  {e,g.  Warren  and  Wdss,  J. 
Biol.  Chem.  1907,  3,  327).  The  picrolonates  are 
less  soluble  than  the  picrates,  and  are  of  most 
use  when  the  base  and  its  picrate  axe  readily 
soluble  in  water  (histidine,  azginine). 

The  above  four  precipitants  may  be  used  for 
obtaining  crystalline  salts  for  analysis  and 
characterisation.  Mercuric  chloride  is  occasion- 
ally used  for  the  same  purpose,  but  more 
frequently  only  for  preparative  purposes  (ms 
quaternary  bases,  alM>ve).  The  following  re- 
agents are  more  sendtive,  but  generally  give 
only  amorphous  precipitates,  unsuitable  for 
analysis. 

hi&mtUh  potoBsium  iodide  (Dragendorff*B  or 


ALKALOlDa 


141 


Kraut*8  reagent)  has  been  nsed  for  isolating 
simple  water  soluble  basea,  which  are  reoop^red 
by  ffiinding  ap  the  briok-red  ptedpitate  with 
freshly  prepared  lead  hydroxioe.  After  filtra- 
tion the  last  traoes  of  lead  are  removed  by 
hydrogen  sulphide.  Cadmium  potassium  iodi(fe 
is  also  employed  as  a  general  a&aloidal  precipi- 
tant. 

Iodine  dissolved  in  aqueous  potassium 
iodide  (Wagner's  or  Bouduurdat's  reagent)  is 
one  of  the  most  general.  In  dilute  solutions  a 
xeddish-brown  precipitate  is  formed,  which  in 
strong  solution  aggregates  at  once  to  a  ereenish- 
black  mass,  and  consists  of  periodides  of  variable 
oomposition.  Many  periocudes  crystallise  from 
alcohol,  the  crystals  beinf  sreen  by  reflected, 
and  red  by  transmitted  fight  (c/.  herapathite, 
under  QuiNms).  The  recovery  of  the  alkaloid 
from  a  periodide  may  be  effected  bv  decolourising 
with  sodium  thi  'ulphate  or  sulphur  dioxide, 
and  shaking  om  "nom  alkaline  solution,  or,  if 
this  is  impossible,  grinding  up  the  periodide  with 
*  molecular  *  copper,  when  only  the  iodide  of 
the  base  remains  in  aqueous  solution. 

Pctasaivm  mercwric  iodide  (Mayer's  or 
Tanret's  reagent)  prepared  by  adding  potassium 
iodide  to  mercuric  cnloride  until  the  mercuric 
iodide  at  first  precipitated,  is  re-dissolved,  is  the 
beet  general  reagent  for  detecting  alkaloids, 
and  may  afford  an  extremely  delicate  test. 
Some  alkaloids  are  most  completely  precipitated 
in  neutral,  others  in  faintly  acid,  a  few  in  more 
strongly  acid  solution.  In  very  dilute  solution 
only  an  opalescence  is  produced,  in  more  con- 
centrated solution  a  yeUowish-white  flooculent 
precipitate  occurs,  from  which  the  alkaloid  may 
oe  recovered  by  suspension  in  water  and  passing 
hydrogen  sulphide.  In  spite  of  its  variable 
composition,  the  precipitate  may  be  used  to 
some  extent  for  quantitative  purposes  {see  next 
seotion). 

Tannic  add  is  merely  a  colloidal  precipitant 
for  complex  substances,  and  jpreoipitates  alka- 
loids, alonff  with  some  gluoosides,  peptones,  fto. 

For  a  full  discussion  of  the  above  and  other 
alkaloidal  feagents,  eee  Allen's  Commercial 
Oigaiiio  Analysis,  1912,  vol.  vi.  186-197. 

QmntttatlTe  efttmatton  of  alkaloids.  As  a 
mle  onlv  the '  total  alkaloid '  can  be  determined, 
alihou^n  in  a  few  oases  of  teohnioal  importance 
U.g.  cmcho]|»  and  strychnos  alkaloids,  q,v) 
mdividual  alkaloids  may  be  cftimated  in  a 
mixture.  The  estimation  of  the  total  alkaloid 
is  based  on  the  same  piindples  as  the  isolation. 
Keller  (Sohweiz,  Woohenschr.  f .  Chem.  u.  Phmnn. 
1894,  32,  44)  mixed  the  finely  powdered  druff 
with  magawrinm  oxide,  or  moistened  it  with 
ammonia,  and  extracted  it  wiUi  ether,  or  a 
mixture  of  ether  and  chloroform.  An  aliquot 
portion  of  the  extract  is  shaken  with  dilute  add, 
the  aqueous  solution  is  rendered  alkaline  and 
again  shaken  several  times  with  ether  or  chloro- 
form. The  alkaloid  left  on  evaporation  of  the 
solvent  mav  be  weighed,  but  in  most  cases  it  is 
more  satisfactory  to  titrate  it  in  aqueous  or 
dilute  alcoholic  solution.  Of  the  various 
indioaton  suggested  methyl  oranse  and  methyl 
red  are  theoreticaOy  and  practiculy  the  best  m 
most  cases ;    the  latter  indicator  is  said  to  be 

?nite  satisfactory  for  all  the  official  alkaloids, 
n  special  cases  hiaematoxylin  is  uded,  and  some- 
times iodeosin  («ee  Allen's  Commereial  Organic 


Analysis,  vol.  vi.  17&-183  ;  and  von  Korczynski, 
Die  Methoden  der  exakten  quantitativen 
Bestimmungen  der  Alkaloide,  Berlin,  1913).  The 
last-named  compilation  gives,  t.a.,  all  the  methods 
of  the  German  Pharmacopoeia ;  the  U.  S.  P. 
may  also  be  consulted.  A  different  principle 
is  involved  in  the  use  of  Mayer's  reagent,  which, 
as  a  rule,  gives  much  less  accurate  results.  As 
a  titration  method  this  is  probably  best  em- 
ployed in  the  form  given  it  by  Heikel  (Chem. 
Zdt.  1908,  32,  1149,  1162,  1186,  1212).  Potas- 
sium mereuric  iodide  is  chiefly  useful  for  quan- 
tities too  small  to  be  titrated  with  add,  and 
should  then  be  used  in  a  nephelometric  compari- 
son with  alkaloidal  solutions  of  known  strength 
(c/.  Ramsden  and  Lipkin,  Aim.  trop.  lifed. 
Parasitol.  1918,  11,  443,  who  thus  estimate 
quinine  in  blood  and  urine  with  considerable 
accuituiy ;  minute  quantities  of  other  alkaloids 
can  doubtless  be  estimated  in  the  same  way). 

Toxieologleal  deteetlon  of  alkaloids.  The 
prindples  are  similar  to  those  involved  in 
extracting  alkaloids  from  plants,  but  owing  to 
the  minuteness  of  quantities  present  and  the 
possible  presence  of  putrefactive  and  other  bases, 
great  care  is  required.  For  details  of  the  methods 
of  Stas-Otto,  Dragendorff,  &c.,  see  Wynter 
Blyth,  Poisons,  their  Effects  enoA  Detection, 
1909;  Kippenbeiger,  Zdt.  anal.  CheuL  1895, 
34,  294;  Schmiot,  Pharmazeutische  Chemie, 
ii.  1911,  1650-58.  Colour  reactions  are  of  Uttle 
use  for  identifying  an  unknown  alkaloid, 
especially  if  impure  (v.  Allen's  Conuneroial 
Organic  Analysis,  1912,  vol.  vi  197-201). 
Pharmacological  tests  are  much  more  useful. 

Bibliography  of  alkaloids  (arranged  chrono- 
logically). 

I.  Guareschi.  'Binfiihrung  in  das  Studium 
der  Alkaloide,  transl.  from  the  Italian  by  H. 
Kunz-Krause.  Berlin,  1896.  (Includes  many 
bases,  natural  and  synthetic,  not  generally 
regarded  as  alkaloids.) 

J.  W.  Briihl.  Roscoe-Schorlemmer's  Lehrbuch 
der  Chemie,  vol.  viii.  1901.  (A  completr^ 
account,  especially  theoretical,  with  full 
literature  references ;  unfortunately  now  some- 
what out  of  date.) 

A.  Pictet.  The  Vegetable  Alkaloids,  transl. 
by  H.  C.  Biddle:  New  York,  1904.  (Deals 
with  questions  of  constitution  and  synthesis.) 

£.  Winterstein  und  G.  Trier.  Die  Alkaloide, 
1910.  (Less  detailed  than  the  above  or  following ; 
speculations  on  the  mode  of  formation  of  alka- 
loids in  plants ;  physiological  actidffk ;  includes 
the  simpler  amines.  Detainee,  &o.) 

J.  Schmidt,  in  Abderhalden's  Biochemisches 
Handlexicon,  vol.  v.  pp.  1-462.  Berlin,  1911. 
(Chiefly  for  literature  references.) 

E.  Schmidt,  PharmazeutiBche  Chemie,  1911, 
vol.  ii.  pp.  1541-1855.  (Very  complete;  men- 
tions many  little-known  afkaloids ;  unfortu- 
nately no  literature  references ;  deals  most  fully 
with  official  alkaloids.) 

Allen's  C6mmercial  Organic  Analysis,  1912, 
vol.  vi.  pp.  167-726,  and  1913,  vol.  vii.  pp.  1-94. 
(Full  analytical  and  technical  accounts  of  the 
better-known  alkaloids.) 

T.  A.  Henry.  The  Plant  Alkaloids.  London, 
1913,  pp.  vi.-466.  (The  most  complete  general 
account  in  English.) 

For  questions  of  constitution  and  synthesis, 
the  following  monographs  are  useful : — 


142 


ALKALOIDP. 


J.  Sohmidt.  Ueber  die  Erfonchung  der 
Konstitation  und  die  Venuche  zar  Synthene 
wiohtiffer  PflanzeniUkaloide.  8tait^art»  1900; 
and  tae  triennial  supplements.  Die  Alkaloid- 
chemie  in  den  Jahren,  1900-1904,  1904^1907, 
1907-1911.  G.  B.  and  F.  L.  P. 

ALKANET.  The  Arabic  name  Al-hennve, 
modified  to  aUeanna  or  al-kenna,  was  ori^inaUy 
applied  to  the  lythraceons  shrub  Lawsonta  afba 
(Lam.),  the  root  •£  which  was  described  as  Radix 
Alkannm  vera,  in  contradistinction  to  the  root 
of  our  alkanna,  which  is  Aru^hun  tinctoria  (Lam.), 
and  which  became  known  as  Badix  AUcannca 
spuria  tindoria.  The  latter,  or  False  alkanet, 
is  also  known  as  OreaneUe,  Fr. ;  Orkanet,  Get. ; 
Languedoc  bup[loss  or  dyers'  bugloss,  Badix 
Alkann<B  spuna.  A  rough  plant  with  downy 
spear-shaped  leaves,  and  clusters  of  purplish  or 
reddish  flowers;  belongs  to  the  BoragifUicea:. 
Found  in  Asia  Minor,  Greece,  Hungary,  &c. 
The  roots,  which  have  an  astringent  taste,  occur 
in  oommeroe,  yarving  from  the  thickness  of  a 
quill  to  that  of  a  finger. 

Alkanet  is  one  of  the  more  ancient  dye- 
stuffs,  having  been  employed  by  the  Romans, 
but,  on  the  other  hand,  it  does  not  appear  at 
any  time  to  have  attained  such  importance 
as  madder,  indigo,  or  even  turmeno.  The 
colouring  matter  of  alkanet,  known  as  an- 
chusin  or  aikannin,  has  been  examined  b^ 
several  chemists,  but  it  is  doubtful  whether  this 
compound  has  as  yet  been  obtained  in  a  che- 
micfuly  pure  condition.  Its  composition  is 
variouiuy  given  as  O17H10O4  (Pelletier,  Annalen, 
6,  27),  (JssMjoOk  (BoUey  and  Wydlers,  Annalen, 
62,  41),  CitHi404  (C^melutti  and  Nasini,  Ber. 
13,  1514),  and  C,5Hi404  or  CisHijO^  (Lieber- 
mann  and  Bomer,  Ber.  20,  2428). 

^llrA^nnin  f  omis  a  dark-red  amorphous  powder 
possessing  a  beetle-green  iridescence,  is  readily 
soluble  in  most  of  the  usual  solventa,  and  its 
alkaline  solution  is  deep-blue  coloured.  On  dis- 
tillation with  zinc-dust  it  gives,  according  to 
Liebermann  and  Romer,  both  methylanthracene 
and  anthracene. 

DiaoetylAlkaimlii  Ci5Hi,04(C,H,0),  forms  a 
dull  yellow  micro-crystalline  powder  (C.  and  N.). 

According  to  Eriksson  (Ber.  Deut.  pharm. 
Ges.  1910,  20,  202),  alkannin  consists  of  two  red 
pigments,  the  one  being  coloured  green  and  the 
other  blue  bv  the  action  of  alkalis.  Red  crystals 
have  been  oBserved  by  Tschirch  in  spaces  m  the 
cortex  of  old  specimens  of  alkanet  root.  As 
alkannin  ii^insoluble  in  water,  in  dyeinff  with 
alkanet  an  alcoholic  extract  is  usually  employed ; 
and  with  aluminium  and  iron  mordanted  fabrics, 
violet  and  grey  shades  are  respectively  produced. 
These  eolours,  however,  are  not  fast  to  light, 
and  are  somewhat  readily  affected  by  weak 
alkalis  or  acids. 

Haussmann  of  Mulhouse  introduced  alkanet 
into  calico-printing,  and  for  a  short  time  it 
appears  to  have  played  a  quite  important  part, 
but  it  is  now  little  if  at  all  employed  in  Europe 
for  ordinary  dyeing  purposes.  ^  is  still  used 
for  colouring  araficiai  wines,  pomades,  hair-oils, 
sweets,  &c.,  and  for  these  purposes  it  is  well 
adapted  on  account  of  its  rMdy  solubility  and 
harmless  nature. 

Bottger  (J.  pr.  ChenL  107,  146)  and  Eng 
(Jahres.  70,  935)  recommend  the  use  of  papers 
stained  by  alkanet  as  indicators  in  alkalimetry. 


According  to  Jolin  (Chem.  Schriften  iiber 
Alkanna,  iv.  84),  Thomson  (Pharm.  J.  [3]  16, 
860),  and  Eriksson  (l.e.),  alkanet  root  contains 
from  5  to  6  p.c.  of  anchusin.  A.  G.  P. 

ALKANNA  or  AL-KENNA.  The  powdered 
root  and  leaves  of  the  Lawsonta  aJba  (Lam.), 
used  in  the  East  for  dyeing  the  nails,  teeth, 
hair,  and  garments.  Used  in  Persia  mixed  with 
lime  for  dyeing  the  tails  of  horses. 

ALKANNIN  (ANCHUSIN)  v.  Alkankt. 

ALKASAL  V.  Syntheho  dbuos. 

ALLANTTE  (v.  Obthitk).  This  is  variously 
regarded  as  a  synonym  or  as  a  variety  of 
orthite.  The  original  aUanite  was  discovered 
at  Kakarsuatsiak  in  east  Greenland  by  C.  L. 
Giesecke  in  1806,  described  by  T.  Allen  in 
1808,  and  named  by  T.  Thomson  in  1810. 
Similar  material  has  been  found  at  numerous 
other  localities  in  Greenland  (0.  B.  Bomld, 
Blineralogia  Groenlandioa,  Kjobenhavn,  19w). 

L  J   8 

ALLANTOn.    Ohfoxt^iureideC^Bfii^^' 

>nhchnhc6nh, 

^NHOC 

.NHC :  NCONH, 
or  C0<         I 

\nhch-oh 

,^NH,CONH     ^  ,^NHC(0H)NH 
or  CO           I       >CO^CO  >CO 

"^^vNHCH-ra     ^  ^viraCH NE 

(Titherley,  Chem.  Soc.  Trans.  1913,  103,  1336 ; 
BUtz,  Ber.  1913,  46,  3410 ;  Mendel  and  Dakin, 
Chem.  Soc.  Trans.  1916,  107,  434)  was  found 
originally  in  the  aUantoio  liquid  01  cows  (Vau- 
quelin  and  Buniva,  Ann.  Chim.  23,  269 ; 
Lassaigne,  Ann.  Chim.  Phys.  [2]  17,  301) 
and  in  the  urine  of  newly-born  calves  (Wohler, 
Annalen,  70,  229) ;  it  occurs  in  the  Uood  of 
the  pig  and  ox  (Hunter,  J.  Biol.  Chem.  1917, 
28,  369-374) ;  in  beetroot  (Smokenski,  Zeitsch. 
Ver  Dtsch.  Zuckeruid,  1910,  1251) ;  in  root  of 
phaseolus  muUiflorus  (Power  and  Salway,  Pharm. 
J.  1913,  [4]  36,  552) ;  in  Anabasis  areiioides  and 
other  plants  (Stieser,  Zeitsch.  physiol.  Chem. 
1913,  86,  269 ;  JcSmson,  J.  Amer.  Chem.  Soc. 
1914, 36, 1, 339) ;  also  in  the  young  leaves,  buds, 
and  stem  of  the  plane  tree  {PkUantu  orieniaUs) ; 
sycamore  {Acer  pseudoj^atanus) ;  in  the  bark 
of  the  horse-chestnut  {mscvlus  hwpocaslanum\; 
in  comfrey  root  (Titherley  and  (^pin,  PhaHh. 
Ja.1912,  34,  &) ;  and  in  rice  polisidngs  (Funk, 
J.  of  Physiol.  45,  75).  Under  normal  conditions 
of  growth  0*25  gram  aUantoin  may  be  isolated 
from  440  grams  of  fresh  young  waves  of  the 
plane,  but  when  the  branches  are  out  in  bud 
and  the  buds  allowed  to  open  in  water,  the 
amount  of  allantoln  increases  to  0*5  or  1  p.c.  of 
the  dried  leaves  (Sohulze  and  Barbieri,  Ber.  1881, 
14,  1602 ;  J.  pr.  Chem.  [2]  25,  145 ;  Sohulze 
and  Bosshead,  Zeitsch.  physiol.  Chem.  1884, 
9,  420).  It  has  been  found  in  the  nitrogenous 
constituents  of  wheat-germs  (Richardson  and 
Crampton,  Ber.  1886,  19,  1180);  in  tobacoo 
seeds  (Scurti  and  Perciabosco,  Gazz.  chim.  itaL 
1906,  36,  ii.  626) ;  and  in  crude  beet  juice  (v. 
lippman,  Ber.  1896,  29,  2652).  Allantoln  is  a 
normal  constituent  of  the  urine  of  mammals; 
the  amount  varies  in  different  species,  being 

greatest  in  the  dog  and  least  in  man  (Frericho, 
t&deler,  J.  1854,  7, 714 ;  Wieohowski,  Biochenu 


ALLANTOIN. 


143 


ZettBoK  1909,  19,  368;  Sohittenhelm,  Zeitsoh. 
physiol.  Ghem.  1909,  63,  248,  269,  283,  289). 
Tlie  whole  quantity  of  aUantoln  excreted  by  man 
on  a  milk  and  vegetable  diet  may  be  derived 
directly  from  the  food  (Aokroyd,  6io-0hem.  J. 
1911,  5,  400).  In  the  oaee  of  the  dog  the 
amount  of  allantoln  in  the  urine  ia  increased 
after  a  diet  of  animal  food  (Salkowski,  Ber. 
1878,  11,  600),  of  oalfs  thymus  (Cohn.  Zeitsch. 
nhyslol.  Ghem.  1898,  25,  607  ;  Mendel,  Amer.  J. 
Physiol.  6,  xiy.-zY. ;  M^Laohlan,  Proo.  Boy. 
Soc  Edin.  1906,  26,  95 ;  and  on  increasins  the 
ingestion  of  water  per  day  from  900  to  3450  c.o. 
there  is  an  increase  of  20  p.o.  in  output  (Fairhall 
and  Hawk,  J.  Amer.  Ghem.  Soo.  1912,  34,  646). 
There  is  about  30  p.o.  increase  in  elimination  of 
allantoln  if  adrenaline  is  introduced  (Falta, 
Zeitsch.  ezp.  Path.  Ther.  16,  366).  It  is  also 
increased  after  the  administration  of  uric  acid 
(Salkowski,  Ber.  1876,  9,  719 ;  Swain,  Amer.  J. 
Physiol.  1910,  6,  38  ;  Wiechowski,  Beitr.  Ghem. 
Physiol.  Path.  1908,  11,  109 ;  Biochem.  Zeitsch. 
1910,  25,  43 1>,  or  of  nucleic  acid  (Mendel,  I.e. ; 
Schittenh^lm,  Zeitsoh.  physiol.  Ghem.  1910, 
66,  53  ;  Wiechowski,  {.c).  Allantoin  is  there- 
fore to  be  regarded  as  an  end-product  of  uric 
add  metabolism  in  the  case  of  such  animals  as 
dogs  and  rabbits  (Wiechowski,  l.c. ;  Schitten- 
he£n,  Lc).  For  the  importance  of  aUanto'in  as 
end-product  in  purine  metabolism  in  monkeys, 
$ee  Hunter  and  Giyeus,  Pro.  Amer.  Physiol.  Soo. 

1910,  xv.-xvi. ;    Amer.  J.  Physiol.  27,  1910- 

1911,  xv.  Allantoln  is  of  therapeutic  value 
(Funk,  J.  of  Physiol.  46,  489-492),  and  is  used 
to  induce  cell  proliferation  in  cases  of  bums,  &o. 
(Titherley  and  C!oppm,  Pharm.  J.  1912  [iv.]  34, 
92-94).  Allantoin  injected  increases  the  blood 
pressure  (Baokmann,  Zentral.  blatt  f.  Physiol. 
^,  166). 

The  ii^ethod  of  preparation  of  aUantoTn  by 
oxidising  uric  acid  with  lead  peroxide  in  presence 
of  water  is  due  to  Liebig  and  Wohler  (Annalen, 
1838,  26,  246) ;  it  has  been  modified  by  Mulder 
(Annalen,  1871,  169,  349),  who  effects  the 
oxidation  in  dilute  aoetic  add  solution  and  in 
br^Lt  dajiight;  by  this  method  100  grams 
of  urio  add  yield  30-32  fframs  of  allantoln. 
A  quantitative  yield  of  aflantom  is  obtained 
whm.  urio  acid  is  oxidised  by  an  alkaline  solu- 
tion of  potassium  permanganate,  and  the 
intermediate  compound 

.NHCO^HOH)!^^ 


^NH- 


[OH)NH 


deoompos(d  by  acetic  add  (Sundvik,  Zeitsch. 
physiol.  Ghem.  1904,  41,  343;  Behrend, 
Annalen,  1904,  333,  141 ;  and  1916,  410,  340- 
341).  AUantom  is  also  obtained  by  the  action 
of  nitrous  acid  on  dialurio  add  (Gibbs,  Annalen 
Soppl.  1870,  7,  337).  The  synthesLs  of  allantoln 
has  Deen  effected  (1)  by  Qrimaux  (Gompt.  rend. 
1876,  83,  62)  by  heating  a  mixture  of  glyoxylic 
acid  (I  part)  and  carbamide  (2  parts)  at  100^ 
lor  8-10  hours ;  (2)  by  Michael  (Amer.  Ghem. 
J.  1883, 6, 198)  by  heating  a  mixture  of  mesoxalio 
aoid  and  carbamide  in  equal  proportions  at 
110°;  (3)  by  Simon  and  Ghavanne  (Gompt. 
rend.  1906,  143,  61)  by  the  action  of  ammonia 
or  alkali  hydroiddes  on  ethyl  aUantoate  GH(NH' 
GO-NHJ^GOtEt,  obtained  by  the  condensation 
of  ethyl  glyoxylate  with  carbamide;    (4)   by 


Behrend  and  Zieger  (Annalen,  1916,  410,  337- 
373)  by  condensing  urio  add  and  aUoxanic  acid 
in  DoiBng  aoetic  anhydride ;  (6)  by  Bilte  and 
Giesler  (Ber.  1913,  46,  3424)  by  the  action  of 
potassium  oyanate  on  6-amino  hydantoin 
nvdrochloride ;  and  (6)  by  Biltz  and  Heyn 
(Annalen,  1916,  413,  39)  by  the  action  of  barium 
hydroxide  solution  on  i^iro-6,5,-dihydantoin. 

AUantoin  is  readily  soluble  in  boiling  water, 
sparingly  so  in  cold  (1 :  131*6  at  21*8°)  (Grimaux, 
Ann.  Chim.  Phys.  1877,  [v.]  11,  389);  it  is 
optically  inactive  (Mendel  and  Dakin,  J.  Biol. 
Gnem.  1010,  7,  163) ;  ciystallises  in  glassy 
monoclinic  prisms  (Dauber,  Annalen,  1849,  71, 
611 ;  Hunter,  Biochem.  J.  28,  369) ;  its  heat 
of  combustion  at  constant  pressure  is  -f  413*8 
Gal.  (e/.  Emery,  Benedict,  Amer.  J.  Physiol. 
28,  1911,  303),  and  heat  of  formation  +170*4 
Gal.  (Matignon,  Ann.  Ghim.  Phys.  1893, 
[vi.1  28,  106).  It  melts  at  227"*  (Titherley 
and  Goppin),  236°  with  decomposition  (Watt, 
Pharm.  J.  1917,  46,  283),  236^-236°  (decomp.) 
(BUtz  and  Heyn,  ibid.  40}  ;  232°  (Hunter,  I.e.). 

Allantoin  forms  a  silver  salt  G4H,OaN4Ag 
(Liebig  and  Wohler,  l.c.)  and  a  potassium 
salt  Cfifi^NJL  (Mulder,  I.e.) ;  it  also  com- 
bines with  certain  metallic  oxides  to  form  spar- 
ingly soluble  compounds ;  the  mercury,  copper, 
zinc,  lead,  and  cadmium  derivatives  are  de- 
scribed by  Limpricht  (Annalen,  1863,  88,  94). 
(For  the  method  of  estimating  allantoln  based  on 
the  sparing  solubility  of  the  silver  and  mercury 
derivatives.  Bee  Loewi,  Zeitsch.  anal.  Ghem.  1900, 
39,266;  Poduschka,  t&ici.  267).  Allantoln  from 
even  0*1  p.e.  solution  can  be  nearly  quantita- 
tively precipitated  with  mercuric  chloride  and 
sodium  hydroxide  or  carbonate  (Hunter,  J.  Biol. 
Ghem.  1916, 28, 270).  For  titrimetric  estimation 
in  urine,  see  Handovsky  (Zeitsch.  physiol.  Ghem. 
90,  211-220);    for  estimation  in  urine  and  in 

Sresence  of  sugar,  Plimmer  and  Skelten  (Biochem. 
.   1914,  8,  70-73,  and  641-648) ;    Giveus  (J. 
Biol.  Ghem.  1914,  18,  417-424). 

AUantoln  is  oxidised  by  potassium  ferricya- 
nide  in  the  presence  of  potassium  hydroxide  to 
potassium  aUantoxanate 

yNHGO 

cor 


'\ 


NH 


•C :  NGO,] 


(van  Smbden,  Annalen,  1873,  167,  39) ;  the  free 
acid  does  not  exist,  but  breaks  down,  when 
liberated  from  its  salts,  into  carbon  dioxide  and 
allantoxaldin 

/NHGO 

\NHC  :  NH 

(Ponomareff,  Ber.  1878,  11,  2166).  For  oxida- 
tion of  with  bromine  liquors  (see  Ck>rdier, 
Monatsh.  33,  769-796).  Methylallantoln  and 
isomerides  (Fischer  and  Ach,  Ber.  1899,  32, 
2746;  Biltc  and  Heyn,  Annalen,  1916,  413, 
83-85,  and  97);  l-fneihykiUanUnn  (a-methyl- 
allantoln)  obtained  from  9-methyl  urio  acid, 
has  m.p.  260''-262°  (decomp.),  Fischer  and 
Ach,  m.p.  256*-269°  (cOrr.)  decomp. ;  3-meth^  1 
aUantoTn  (^P  -  meihylaOanUnn)  ciystallises  m 
prisms  with  one  molecule  of  water,  m.p. 
226°-227°,  decomp.,  Fiseher  and  Ach,  m.p. 
226°-227°  (oorr.)  decomp.  ;  3,  S-dimdhylaUantdin 
is  obtained  from  3,  7-dimethyl8piro-dihydanto!n, 
m.p.    222^    turns    yellow    (aeoomp.);    1,    6- 


144 


ALLANTOIN. 


dimeikylaUantoin,  obtained  from  1,  9 -dime- 
thylgpirodihydantoin,  m.p.  226^-227°  (K.  Th.) 
(deoomp.).  M.  A.  W. 

ALLEMONTTE.  A  natiye  alloy  of  arsenio 
and  antimony,  SbAss,  found  at  Alleraont  in  the 
Dauphin6,  Pmbram  in  Bohemia ;  and  Andreas- 
berg  in  the  Hartz. 

ALLMATEIN.  Trade  name  for  a  condensa- 
tion prodnct  of  hsematoxylin  and  formaldehyde. 

ALLOSAN.  Trade  name  for  santalyl  allo- 
phanate. 

ALLOXAN.   Mesozalylearbamide 

found  by  Liebig  (Annalen,  121,  81)  and  by 
Lang  (Zeitsch.  anaL  Chem.  6,  294)  in  certain 
pathological  exoretionB,  is  one  of  the  oxidation 
products  of  uric  add,  and  was  first  prepared  by 
Brugnatelli  (Ann.  Chim.  Phys.  1817,  8,  201; 
from  Giomale  di  Fisica,  decade  seoonde  L  117), 
under  the  name  of  eryihric  acid,  by  oxidising 
uric  acid  by  means  of  nitric  acid,  chlorine  or 
iodine.  Liebig  and  Wohler  (Annalen,  1838,  26, 
256),  who  systematically  studied  the  oxidation 
of  uric  acid,  fave  to  tms  product  the  name  of 
aUoxan,  regarding  it  as  bearing  the  same  relation 
to  t^rUdin  and  oxalic  acid  that  oxdluric  acid 
does  to  oxalic  acid  and  urea.  According  to 
Liebig  and  Wohler  (l.c.)  and  to  Greffory  (Mem. 
Chem.  8oa  1848,  iii.  44),  alloxan  can  oe  obtained 
most  readily  and  with  a  yield  of  90  p.o.  by 
careful  oxidation  of  uric  acid  by  means  of  nitric 
acid,  sp.gr.  1*412. 

According  to  Schlieper  (Annalen,  1845,  55, 
261),  the  oxidation  of  uric  acid  to  alloxan  is 
more  conveniently  effected  with  hydrochloric 
add  and  potassium  chlorate ;  4  parts  of  uric  acid 
are  mixed  with  8  parts  of  hydrochloric  acid, 
and  1  part  of  finely  powdered  potassium  chlorate 
added  in  successive  small  quantities,  avoiding 
the  liberation  of  chlorine;  after  two  or  three 
hours  tiie  dissolved  alloxan  ia  reduced  by  means 
of  Bu^huretted  hydrogen  to  the  sparingly 
soluble  aHoaniUin,  This  is  separated  from  the 
sulphur  by  crystallisation  from  hot  water,  and 
oxidised  to  alloxan  by  the  action  of  diluted 
nitric  add.  Bilts  (Annalen,  1916,  413,  60) 
prepares  aUoxan  from  uric  add  in  one  operation 
Dy  oxidation  with  chlorine. 

Alloxan  orystaUiaes  from  warm  saturated 
aqueous  solution  in  large  tridinio  prisms  con- 
taining 4H,0 ;  on  exposure  to  the  air  or  on 
heating  at  lOO""  it  loses  3HaO,  and  the  dried 
compound  has  the  composition  expressed  by 
the  formula 

CO<JJg:^>C(OH), 

(Lang,  Grailich,  J.  1858,  308 ;  Hartley,  Chem. 
Soo.  Trans.  1905,  87,  1802) ;  it  is  also  obtained 
in  oblique  rhombic  piiBms,  bdonging  to  the 
monodmio  system  on  evaporating  an  aqueous 
solution  at  65^-70^.  The  remaining  molecule  of 
water  is  lost  at  150^.  By  heating  under  reduced 
pressure  it  ib  posnble  to  dehydnLte  alloxan  and 
its  mono-  and  dimethyl  derivaties,  all  of  which 
sublime  unchanged  in  vacuum. 

AUoxan  arthydride  CfifiJ^O^  yellow  rhom- 
bic crystals,  has  m.p.  256°  (deoomp.). 

They  are  depodted  from  alcohols  containing 
a  little  hydrochloric  add  in  the  form  of  alco- 
holatee ;    these    when    heated    eliminate    the 


molecule  of  alcohol  and  leave  a  residue  with  • 
the  melting-point  of  the  anhydride  (Biltz,  Ber. 
1912,  45,  3659-3675). 

AUoxan  anhydride  O^HgO^N,,  yellow  rhom- 
bic crystals,  has  m.p.  256°  (deoomp.). 

When  crystals  of  alloxan  are  xept  for  some 
years  in  closed  vessels  they  sometimes  undei^ro 
spontaneous  decompodtion,  forming  alloxantm, 
parabanic  add,  and  carbon  dioxide.  According 
to  Gr^ory  (Annalen,  1853,  87,  126),  this  \&  due 
to  the  presence  of  traces  of  nitric  acid  contained 
in  the  water  of  crystallisation.  Similar  pheno- 
mena were  observed  by  Baumert  (Pogg.  Ann. 
1860,  110,  93),  by  Hdntz  (Pogg.  Ann.  1860,  111, 
436),  and  by  Otto  (Annalen  Suppl.  1865, 4,  256). 
Cases  of  spontaneous  explosive  decompod- 
tion of  alloxan  are  recorded  oy  Wheeler  and  by 
Bogert  (J.  Amer.  Chem.  Soc.  1910,  32,  809); 
the  products  of  decompodtion  being  carbon 
dioxide,  carbamide,  oxauc  add,  and  uloxantin 
(Gortner,  J.  Amer.  Chem.  Soo.  1911, 33, 85). 

The  molecular  heat  of  combustion  of  i^oxan 
is  276*5  Cal.  (Matignon,  Ann.  Chem.  Phys.  1893, 
[vil  28,  300) ;  the  dissociation  constant  is 
2*32x10-^  (Wood,  Chem.  Soc.  Trans.  1906,  89, 
1835).  The  dissociation  constant  K  (in  diazo- 
aoetio  ester  solution)  =0*03542,  Ch=0'000920, 
and  the  sp.  conductivity  at  25°  (not  deducting 
that  of  water,  1*1  x  10-^=1*27  X  10-»  (Caloagin, 
Atti  R.  Accad.  dd  Lined,  [5]  25,  L  643-648). 
In  common  with  the  other  simple  urddes,  alloxan 
shows  no  absorption  bands  in  its  speotrum 
(Hartley,  Chem.  Soc.  Trans.  1906,  87, 1815). 

Alloxan  is  readily  soluble  in  alcohol  or  water ; 
the  solution  \b  add  to  litmus,  stains  the  skin 
purple,  and  imparts  to  it  a  curious  and  un- 
pleasant odour.  Li  its  phydological  action 
alloxan  affects  the  central  nervous  system^ro- 
dudng  first  stimulation,  then  paralysis.  Wnen 
taken  internally  it  is  exoretea  in  the  urine  as 
alloxantin  and  parabanio  add  (Lusilii,  Chem. 
Zentr.  1895,  ii  311,  727,  838 ;  Eoehne,  Chem. 
Zentr.  1894,  iL  296). 

Alloxan  is  readily  oxidised  by  warm  dilute 
nitric  acid,  forminff  carbon  dioxide  and  para- 
banic acid  {oxalykanamide)  (q.v.) ;  is  reduced  by 
sulphuretted  hydro^^en,  stannous  chloride,  Einc, 
ana  hydrochloric  acid,  or  by  boiling  with  excess 
of  sulphurous  acid  to  aUoxaniin  {q.v.) ;  and  is 
readily  hydrolysed  by  alkali  carbonates  or  by  the 
hydroxi(fes  or  chlondes  of  the  alkaline  ewths, 
forming  the  corresponding  salt  of  aUoocanie  acid. 
Th^  barium  and  calcium  salts  are  insoluble. 

,/NHCOv  /CONH-OO^NH, 

00  >CO-fH,0=CO 

\NH<XK  \COOH 

If,  however,  excess  of  alkali  is  employed  or  the 
solutions  are  heated,  the  hydrolysis  is  carried 
to  completion  with  the  formation  of  mesoxalio 
acid  and  carbamide  (Schlieper,  Annalen,  1845^ 
55,  263 ;  56,  1 ;  Biltz,  Annalen,  1916,  413, 
70).  Alloxan  gives  a  deep-blue  colour  with 
ferrous  salts,  but  no  precipitate  is  formed  unless 
an  alkali  is  present.  According  to  Agrestini 
(Boll.  Chim.  Farm.  1902,  41,  5-7;  Chem. 
Zentr.  1902,  L  631),  the  formation  of  blue  colour 
is  dependent  on  th^  presence  of  a  trace  of 
ammonia  or  caustic  alkali,  and  the  same  deep- 
blue  colour  LB  also  given  by  pure  ferric  salts 
under  similar  conditions.  For  similarity  in  the 
behaviour   of   triketohydrindene   hydrate   and 


ALLOXAN. 


146 


alloTMi,  tee  RqhwnMm  (Ghem.  Boo.  T^uii. 
1911,  09,  793);  Timnbe  (B«r.  1911,  44,  S145) ; 
Reti^Ser  (J.  Amer.  Ghem.  Soa  1917,  39,  1069). 
AUnran  giyee  the  mnrezide  reectioii,  aod 
Angnetmi  (he,)  finds  that  the  unmoma  in 
the  reection  can  be  replaoed  by  certain  add 
amidm,  amino  acida,  or  sobetitiited  aminea; 
Roaenheim^s  alloTan  teat  for  choline  (J.  PhysktL 
1906,  33,  220),  namely,  the  formation  of  a 
deep  led-Yiolet  colour  when  a  drop  of  a  1  p.o. 
wmtion  of  chcdine  hydrochloride  is  eyaporated 
on  the  water-bath  with  a  few  drops  of  a 
saturated  solution  of  alloxan,  is  probably  a 
reaction  of  the  same  order. 

Other  tests  for  alloxan  are  (1)  the  formation 
of  a  deep  violei-bfaie  ooknir  when  a  solution  of 
alloxan  is  boiled  for  a  few  nunntes  with  a  drop 
dpjrrrolDL  The  colour  changes  to  red  on  cooling, 
becoming  men  and  then  intensely  blue  on  the 
addition  ol  alkalL  (2)  The  bfaie-green  solution 
obtained  on  mixing  concentrated  snlphoric  acid 
soliitions  cl  alloxan  (or  alloxantin)  and  pyro- 
catechdl,  the  colour  chan^  to  an  intense 
green  on  dilution  (Agrestmi,  Ix.y,  Hartiey 
(Ghem.  Soc.  Trans.  1905,  87,  1816)  finds  that 
hydrated  alloxan,  when  powdered  along  with 
pure  calcite,  acquires  a  yellowish-pink  tinge. 
After  half  an  hour  the  colour  is  decided  and  it 
is  permanent ;  on  adding  water  a  red  solution 
is  obtained.  When  alloxan,  dried  at  100%  is 
similarly  treated,  there  is  no  colour  developed 
until  water  has  been  added.  AHoxanio  acid 
gives  no  such  colour  reaction.  Alloxan  yields 
uoohdatee,  phenolates,  and  sulphites  (Bilts, 
Ber.  1912, 45, 3667-3670),  also  a  coxnpound  with 
hydrogen  peroxide  (G4H,04Na)ioH,0,  (Stolzen- 
bei^  Bw.  1916,  49,  1545). 

For  other  derivatives  of  alloxan,  see  Behrend 
and  Zieger  (Annalen,  1916,  410,  337-373). 

PoUusnim  aOoaoan  Qfifi^JL^  pale  red 
needles,  decomposes  about  236**. 

Catbamide  aOoxanale  CfifiJ^t,CO(NRt)^, 
crystalliBes  in  four-sided  prisms,  decomposes 
166*-166% 

Urea  and  alloxan  also  form  a  compound 
CsH.O,N«,  decomposes  in""  or  133''-134%  is 
probably  a  salt-like  compound.  It  gives  uric 
acid  and  glycol  when  heated ;  boiled  with  acetic 
anhydride  it  yields  an  anhvdride  CsH(05N49 
mieroBOopic  needles,  m.p.  186 -186% 

Mei^fl  aUommale  CfifiJ^^,  prisms,  decom- 
poses 176*'-176% 

The  following  homoiogues  of  alloxan  have 
been  described : — MdhyltuUnan 

prepared  from  methyl  uric  acid  (Hill,  Ber.  1876 
»,  1092) ;  from  C-xaio  acid  (Fischer,  Ber.  1899, 
32,  2731) ;  from  theobromine  (Maly,  Andreasoh^ 
.Monatoh.  1882,  3, 108 ;  Fischer  and  Clemm,  Ber. 
1897,  30,  3090).  It  oystallises  from  water  in 
brilliant  colourless  prisms,  becomes  anhydrous 
at  60*  in  a  vacuum,  and  decomposes  at  156% 
DimiihylaUoxan 

oo<nm::co>(OH)..h.o 

prepared  by  oxidising  caffeine  (Fischer,  Annalen, 
1882, 215, 267 ;  Maly,  Andreasch,  Monatsh.  1882. 
3,  96),  by  boiling  dichlorodimethylbarbituric 
acid  with  water  or  silver  oxide  (Tcchow,  Ber. 

Vou  L— T. 


1894,  27.  SOBS),  loses  1H,0  when  dried  o 
sufohuiie  aokU  deoomposes  at  100°;  the  aa- 
hyorous  compound  is  a  palo  yellow  powder 
soluble  in  alcohol  and  has  m.p.  268^.266* 
(decomp.)  (Bttta,  Ber.  1912, 46,  3669).  2>trUyl- 
aOoxoM  GgHi^O^^  prepared  by  oxidising  1 : 3- 
diethylbarbitnrio  amd  with  nitno  aeid,  contain-  , 
ing  a  little  nitrous  acid  ^mbritaki.  Ber.  1897* 
30,  1880).  Meik^Mk^kMoaetm,  from  ethyltheo- 
bromine  by  oxidation  (Pommerehne,  Apoth. 
Zeit  1897,  12,  6).  Some  derivatives  of  1  :  S- 
dxphenylaUoxan  have  been  described  by  Whiteley 
(Ghem.  Soc.  Trans.  1907,  91,  1344). 

Inasmuch  as  the  alloxan  molecule  contains 
the  mesoxalyl  radical 

(OH,.C<^;   or   00<J5 

it  forms  a  wide  series  of  condensation  products 
through  the  medium  of  the :  C(OH)a  or  :G0  group 
yielding  derivatives  of  the  type 

respectively.  These  compounds  will  be  described 
under  the  foDowing  eight  headings. 

1.  CondensaOon  of  AUonn  inth  BIralphltes. 
— ^Alloxan  forms  condensation  products  of  the 
type  G«H,N.0«,NaHS0^UH.0  with  alkaU 
bisulphites  (lampricht  and  Wuth,  Annalen,  1868, 
108, 41),  and  with  the  sulphites  of  certain  organic 
bases  (Pellizzari,  AnnsJen,  1888,  248,  146). 
AUoxan  ethylamine  stdphiU  GiHyN-SOsH,- 
GAN.O^HJO;  AUoxan  aniline  sulphUeOfijN* 
SOsH„G«H.N.04,2H.O ;  Alloxan  methylaniline 
«d!p*ae(),Bf,NS0,H„C4H,N,0--2H^0 ;  AUoxan 
itm€fAy2tmt7tne«iJp)ktteG,H,iNSO,H,,G.H^.04, 
4H,0,  are  described  and  the  orystaUographio 
constants  are  given.  The  benzidine  compound 
contains  IH.O  ;  toluidinep  aminobenxoie  ac%d,  and 
aapartie  acid  yield  similar  compounds.  AUooDon 
pyridine  eviphite  ia  tridinic,  and  anhydrous 
a^stalline  derivatives  are  afforded  by  ^tnatfie, 
pteciine,  morphine^  and  cinehonine ;  the  strychnine 
compound  has  1H.0,  and  the  hrucine  compound 
IJHjO. 

2.  Condensatloii  of  Alloxan  with  Hydroiqrl* 
amine, — Alloxan  condenses  with  hydroxylamine 
hydrochlonde  (Geresole,  Ber.  1883,  16,  1133)  to 
form  the  oxime,  viciurie  aeid 

CO<n2cO>C:NOH 

{q.v.). 

3.  Condensation  of  Alloxan  with  Hydraihrtt. 

— Hydrazones  of  alloxan  and  its  homologues  can 
be  prepared  by  the  condensation  of  (a)  the 
alloxan  with  the  hydrasine 

^<CNH^a>^^  +  H,NNHPh 

-C0<^.'^8>C^N.NHPh, 

[h)  the  dibromo-  derivative  of  the  corresponding 
barbituric  acid  with  the  hydrazine 

CO<Sh^>CB'.  +  H^-NHPh 

=  CO<CnH  Co!>^  •  NNHPh  +  2HBr, 
(c)  the  corresponding  barbituric  acid  with  the 
diazonium  chloride 


146 


ALLOXAN. 


=  ^<Cot€Ox>^  •  NNHPh. 
And  the  following  hydrazoneB  have  been  pre- 
pared by  one  or  more  of  these  methods : — AUoxan- 
phenylhydrazone 

co<SHm>C'NNHn» 

pale-yellow  crystals,  melts  and  decomposes  at 
298°-300* ;  1 :  S-Dimdhylallcxanphenylkydrcaume 

00<3JJJ::8o>  =  NNHPh 

slender  yellow  crystals,  m.p.  261*  the  o-  and  p- 
nitro  derivatives  are  yellow  crystalline  substances 
and  decompose  at  310*  and  300*  respectively 
(Kfiblinff,  Ber.  1891.  24,  4140 ;  1898,  31,  1972) ; 
(UUtxanphenylmeihylhydriuoine 

CO<^*.^>C :  NNMePh 

brick-red  hexagonal  plates,  decomposes  at  189^- 
191*'(Whiteley,Chem.  Soo.  Proo.  1906,  22,  201) ; 
(dloxandiphenyJhydraxons 

00<Jg."gg>C:NNPh„ 

bright-yellow  powder,  melts  above  270*  (Arm- 
strong and  Rooertson,  Chem.  Soo.  Trans.  1905, 
87,  1291) ;   1 :  ^-diphenylaUoxanphenyUiydrazone 

bright-yellow  needles  that  decompose  at  266*,  the 
p-nitro  derivative  forms  yellow  prisms  with  a 
purple  reflex  and  melt  and  decompose  at  274* ; 
1 :  i-diphenylattoxanphenylmethylhydrazoiie 

^<CNPh-Ca>^  •  NNMePh 
decomposes  at  176^  and  crystallises  in  orange 
red   prisms  or    bright-yellow    needles ;     1:3- 
dipJienylaUcxandiphmylhydrazone 

melts  and  decomposes  at  254^-255*,  and  forms 
yellow  crystals  yielding  an  orange-red  powder  on 
trituration  ;  1 :  S-dipJ^ylaUoxanphenylbemylhy' 
drazone 

CO<jJ|h€a>C :  NNPh-CHjPh 

melts  and  decomposes  at  130*,  crystallises  from 
benzene  in  bright-yellow  needles,  and  from 
methyl  alcohol  in  bright-red  prisms;  from 
toluene  a  mixture  of  the  red  prisms  and  yellow 
needles  is  obtained  ^Whiteley,  Chem.  Soo. 
Trans.  1907,  91,  1344);  aUoxancyanophenyl- 
hydrazone 

from  alloxan  and  aminophenylcyanamide,  straw- 
yellow  compound,  m.p;  286*  (Rolla,  Gazz.  chim. 
ital.  1907,  37,  L  623). 

4.  Condensation  of  Alloxan  with  Semlearba- 

zide. — ^This  reaction  has  been  studied  by  Brom- 
berg  (Ber.  1897,  30,  131).  He  describes  the 
compounds  aUoxanaemicarbazide  C.H,0«N5  and 
dimethyldUoxansemiearhazide  C^HjiOgN,,  but  was 
not  successful  in  determining  their  constitution. 
6.  Condensation  of  Alloxan  with  Diamines. — 
In  the  condensation  jof  alloxan  \^ilh  o-diamines 
the  ketonio  oarbonyl  and  one  of  the  adjacent 


I  oarbimido-  groups  take  part,  and  the  product 
is  an  ttzine ;  aUdcazine 


N:CNH<X) 


c.H,<r     I      I 

\N:C<X)NH 


obtained  from  o-phenylenediamine,  forms  yellow 
microscopic  crystals  that  decompose  above  300* ; 
similar  derivatives  were  obtamed  from  3 : 4- 
diaminotoluene  and  a-jS-diaminonaphthalene 
(Kfihling,  Ber.  1891,  24,  2363)  ;  for  the  effect  of 
oxidising  and  reducing  agents  on  these  com- 
pounds, compare  KUhlmg,  Ber.  1895,  28,  1968 ; 
1899,  32, 1650). 

llie  condensation  of  alloxan  with  mono- 
substituted  o-diamines  results  in  the  formation 
of  two  compounds  according  as  one  or  more 
alloxan  molecules  take  part  in  the  reaction. 
Thus  alloxan  condenses  with  ortkaminoditolyl- 
amine  at  the  ordinary  temperature  to  form 
aUoxanylorthaminoditolylamine 


NH> 


0^/NH-C,H,-N :  0<^c6 


glittering  yellow  prisms,  that  melt  and  decompose 
at  252*,  and  dissolve  in  concentrated  sulphuric 
acid  with  a  deep  red  colour ;  if,  however,  the 
condensation  is  effected  in  the  presence  of  f  umine 
hydrochloric  acid  and  the  mixture  is  boiled, 
diaUoxanylorlhaminoditolylamine 

C(OH)N(C,H,)-C,H,-N:C 

00      CO  OC     CO 

HN    NH  HN     NH 


V 


V 


is  formed.  It  is  crystalline,  and  blackens  at 
300*,  dissolves  readily  in  alkali  carbonates,  and 
gives  a  deep-blue  solution  in  concentrated 
sulphuric  acid.  Dimethylalloxan  gives  similar 
derivatives  (Knhling,  Ber.  1893,  26,  540),  and 
similar  condensation  products  are  obtained 
from  alloxan  and  phenyl-o-phenylenediamineb 
o-aminodi-j}-tolylamine,  and  N-methyl-o-pheny- 
lenediamine  (Kuhling  and  Kaselitz,  Ber.  190o ; 
39,  1314) ;  and  from  tetramethyl-m-phenylene- 
diamine  (Sachs  and  Appenzeller,  Ber.  1908,  41, 
91). 

6.  Condensation  of  Alloxan  with  Aromatle 
amines. — Alloxan  condenses  readily  with  pri- 
mary aromatic  amines  (Pellizzari,  Gazz.  chim. 
ital.  1895,  17,  419)  to  form  aminoaryl  sub- 
stituted cUaluric  acids,  yielding  on  hydrolyns 
with  alkali,  the  corresponding  tartronio  acid 
(g.v.).  Thus  aniline  and  alloxan  give  |>-amino- 
pnenyldialuric  acid,  and  this  on  hydrolyBia 
yidds  p-aminophenyltartronio  acid 

CO<Sh^^>^(OH)«  +  0,H.NH, 

=  co<^h'co>^oh)-c.h,.nh^ 

00<^hSo>C(OH)C,H4-NH,  +  4K0H 
=  NH,-C,H4-C(OH)(COjK),4-2NH,+K,CO,. 
In  view  of  the  importance  of  these  compounds 
as  sources  of  tartronio  acids,  their  preparation 
forms  the  subject  of  a  patent,  D.  R.  P.  112174 
(Frdl.  1900-1902,  158-159).  in  which  the  amino- 
aryl- dialuric  and  tartronio  acids  obtained  from 


ALLOXANTU«. 


147 


the  followhig  hnen  an  deReribed :  ethylaniline, 
diethylanilme,  beDs^Uuiiline,  methylbenzylaiu- 
line,  ethylbenasylaziuine,  diphenvlaiiiine,  o-tolu- 
idine,  o-ethyltolaidme,  o-aniadine,  methyl-o- 
anindine,  o-pheneiidme,  m^hloraniline,  m-ohlor- 
dimethyUtniune,  and  m-chlordiethylaniline. 

By  careM  oxidation  with  potassium  perman- 
ganate of  the  alkali  salts  of  tne  taitronio  aoids, 
or  by  oxidising  the  corresponding  dialnric  aoid 
with  mercnrio  oxide  in  presence  of  potassium 
hydroxide,  the  oorrespondmg  glyoxylic  acid  {q,v,) 
can  be  obtained 

=  NH,-C^<X)<X),H  +  CO,  +  H,0 
and  the  preparation  by  these  methods  of  an 
important  series  of  slyoxylio  aoids  forms  the 
subject  of  patents  D.  R.  P.  117021,  26/11, 
1900 ;  and  117168,  3/12,  1900. 

Alloxan  condenses  also  with  pyrazolone  bases 
to  form  derivatives  of  dialuric  aoid  (tartronyl- 
carbamide),  and  these  on  hydrolysis  with  oold 
caustic  alkali  yield  the  correspondmg  substituted 
tartronimides  (Pellizzari,  Gazz.  chim.  ital.  1888, 
18,  340).  ThuBphenyhndhylpyraxoUmektHrxmyl- 
avhamiie 

forms  long  yellow  needles  that  decompose  at 
170*-178*,  and  yield  phenylmethylpyrazoUmetar 
tronimide 

on  hydrolysis ;  phenyldinuthylpyrazoloruiar- 
trimylcarbamide 

melts  and  decomposes  at  26 1^  and  yields 
phenyldimMylpyrazoUmeUirtroniinide 

deoomposing  at  246^-250^. 

7.  Condfliisatlon  of  Alloxan  with  Phenols.— 
Alloxan  condenses  in  the  presence  of  hydrogen 
chloride,  sulphuric  aoid,  or  zinc  chloride  with 
mono-  or  polyhydroxy-  phenols  to  form 
derivatives  of  dialuric  acid  (tartronylcarbamide), 
that  promise  to  be  of  value  for  pharmaceutical 
purposes,  and  axe  readily  converted  bv  hydrolysis 
mto  the  oorresponding  tartronic  acid  : 

OH-C^,  +  (OH),0<gg:^f >C0 

\OONH 

-»    OH-Cja^CCOHXCO^H),. 

A  description  of  the  compounds  obtamed 
from  alloxan  and  the  phenolic  oompoundst  phenol, 
m-oresol,  j^-cresol,  guaiaool,  pyrooateohol,  resor 
cinol,  hydroquinone,  pyrogaUol,  a-naphthol,  is 
given  in  D.  R.  P.  107720,  25/8,  1898;  113722, 
9/7, 1900 ;  114904, 17/9, 1900;  and  the  tartronic 
aoids  derived  from  them  are  described  in  D.  B.  P. 
116817,  8/10, 1900. 

&  Condensation  of  Alloxan  with  Ketones.— 
Alloxan  condenses  with  acetophenone  and  certain 
of  its  homologies  to  form  phenacyldis^uric  acid 
or  its  derivatives  of  which  the  following  are 


described  by  Kuhling   (Ber.  1905.  88,  3003) 
Kahling  ana  Schneider  (Ber.  1909,  42,  1285) : 
phenaeyldialuric  acid 

yOONH 

COPh-CH,-d(OH)       \C0JI,0 

XCDNH^ 
m.pe  212*,  with  decomposition;  the  hromo- 
derivative  decomposes  at  217*;  p-tthoxyphen' 
acyldiahiric  add  C.4H,40,N„  m.p.  214* ;  the 
bromo-  derivative,  decomposes  at  201* ;  aydi- 
phenylaeetonyldialuric  acta 

CH,PhCOCHPh-d(OH)       \x) 

\C0NH 

m.p.  233*  with  decomposition ;    p-methylphen- 
acyldialuric  acid 

yOONH 

Cja4Me-C0-CH,-d(0H)       y>CO 

\CONH 
m.p.  241*-242*,  with  decomposition ;  the  acetyl 
derivative  decomposes  at  220*,  the  htmoyl  at 
215° ;  p-methoxyphenacyldialuric  acid  C,,H.,OgNs 
decomposes  at  227*,  and  yields  an  acetyl  deriva- 
tive, m.p.  207*. 

For  condensation  products  of  alloxan  and  sub- 
stituted  rhodamic  acids  {see  Butscher,  Monatsh. 
1911,  32,  9-19),  and  alloxan  with  amino- 
antipyrine  {see  Meyer,  Oompt.  rend.  1911,  152, 
1677).  M.  A.  W. 

ALLOXAHIC  ACID  v.  Alloxan  ;  and  BUtz, 
Hern,  Bergius  (Annalen,  1916,  413,  368) ; 
B^remd  and  Zieger  (Annalen,  1915,  410, 
337). 

ALLOXAHTDf  08H«OsN4,2H,0  (Ritthausen, 
Ber.  1896,  29,  892)  exists  in  small  quantities  in 
crude  beet-juice  (Ldppmann,  Ber.  1896, 29, 2645), 
and  forms  34  to  36  p.c.  of  the  products  when  con- 
viein  from  sow-beans  ( Vicia  faba  minor)  or  from 
vetches  {Vicia  eaiiva)  is  hydrolysed  by  dilute 
mineral  adds  (Ritthausen,  he. ;  J.  pr.  Chem. 
1899,  [ii.]  59,  487).  Johnson  (J.  Amer.  Chem. 
Soc.  1914,  36,  337-343)  discusses  its  origin  in 
plants.  Alloxantin  was  first  prepared  by  Liebig 
and  Wohler  (Annalen,  1838, 26, 262)  by  oxidising 
uric  acid  with  dilute  nitric  aoid;  or  by  the 
direct  union  of  alloxan  and  dialuric  acid,  or  by 
reducing  a  cold  aqueous  solution  of  alloxan  with 
sulphuretted  hydrogen  or  stannous  chloride. 
According  to  Vitali  (Chem.  Zentr.  1898,  i.  665, 
from  Boll.  Chim.  Farm.  37,  65),  the  reduction 
can  also  be  effected  by  means  of  hydriodic  acid. 
Alloxantin  was  synthesised  by  Grimaux  (Compt. 
rend.  1878,  87,  752)  by  heating  malonic  acid, 
carbamide  and  phosphoiyl  chloride  at  160°, 
and  passing  sulphuretted  hydrogen  through  a 
nitric  acid  solution  of  the  crude  product;  or 
by  passing  sulphuretted  hydrogen  tnrouffh  a  hot 
aqueous  solution  of  dibromobarbituno  aoid 
(C!ompt.  rend.  1879,  88,  86).  Koech  (Annalen, 
1901,  315,  246)  describes  the  conversion  of  iao- 
dialurio  acid  into  alloxantin  by  heating  it  with 
guanidine  and  acetic  acid ;  tne  change  seems 
to  be  due  to  the  transformation  of  the  i^odialurio 
acid  into  dialuric  acid  by  the  action  of  the  base, 
and  the  subsequent  oxidation  of  the  dialuric 
acid  to  aUoxantin,  since,  if  the  reaction  is  con- 
ducted in  an  atmosphere  of  carbon  dioxide, 
dialuric  acid  only  is  obtained.  An  aqueous 
suspension  of  aUoxantin  possesses  oonsiderabie 


148 


ALLOXA!n*IN. 


oxygen  eonanming  powor  (Thnnbeig,  Skand. 
Arch.  Physiol.  1916,  33,  217). 

Alloxantih  oryBtaUlses  from  aqneons  Bolntioiis 
in  small  sharp  rhombic  prisms,  containing  2  mols. 
H,0 ;  it  becomes  anhvdrons  after  heating  for 
1-li  hours  at  150^,  or  for  6  hours  at  lOT^'-llO*' ; 
it  decomposes  at  170^  into  hydorilio  add, 
ammonia,  carbon  monoxide,  carbon  dioxide,  Imd 
oxalic  acid ;  turns  yellow  at  225®,  and  decom- 
poses at  263''-256'*  (Biltz,  Ber.  1912,  45,  8675). 
It  is  decomposed  into  barbituric  add  and 
parabanic  acid  when  heated  with  concentrated 
sulphuric  add  at  120®,  or  into  allituric  add 
CfHeOfN^  when  boiled  with  excess  of  hydro- 
chloric acid  (Schlieper,  Annalen,  1845,  56,  20). 
Alloxantin  is  sparingly  soluble  in  cold  water 
(0*2885  gram  per  100  c.c.  at  25®,  of  which  about 
22  p.c.  is  unoissociated,  Biilman  and  Bentaon, 
Ber.  1918,  51,  522),  yielding  an  add  solution 
that  reduces  solutions  of  silver  salts,  and  gives 
a  characteristic  violet-blue  predpitate  with 
baryta  water,  changing  on  wanning  into  the 
colourless  barium  alloxanate  which  undewoes 
further  decompomtion  into  barium  mesoxuate 
and  barium  carbonate  (Liebig  and  Wohler, 
Annalen,  1838,  26,  312).  Alfoxantin  has  a 
molecular  heat  of  combustion  «=  584*7  Cals. 
(Matignon,  Ann.  Chim.  Phys.  1893,  [6]  28,  323), 
and  a  freshly  prepared  aqueous  solution  shows 
a  remarkable  amorptlon  band  in  the  ultra- 
violet, which  disappears  upon  keeping  the 
solution,  owing  to  the  decompodtion  of  the 
alloxantin  into  alloxan  and  dialunc  add  (Hartley, 
(niem.  Soa  Trans.  1905,  87,  1814).  For  this 
reason  Hartley  expresses  the  constitution  of 
alloxantin  by  the  formula 

^NHCO\  yCONHv 

COC        HO-^COCf-H  >C0 

^NH-CO/  NCONH^ 

(tbid.  1819 ;  see  also  Biilmann  and  Bentmm,  Ber. 
1918,  51,  522;  Slimmer  and  Stieglitz,  Amer. 
Chem.  J.  1904,  31,  661).  Pilotv  and  Finckh 
(Annalen,  1900,  333,  22)  found  that  alloxantin 
was  resolved  into  iJloxan  and  dimethylamine 
dialurate,  byboiling  with  dimethylamine  acetate, 
and  suggest  the  constitutional  formula 

in  which  the  relationship  between  alloxantin  and 
alloxan  is  the  same  as  that  existing  between 
quinhvdrone  and  quinone.  In  diazo  acetic  ester 
^e  dissociation  constant  is  0*0006331,  con- 
centration of  H  ions  0*00001644,  and  sp.  con- 
ductivity at  25®  (not  deducting  that  of  water 
1 ,1 X  10-«)  1,13  X 10-*  (Calcagni,  Atti.  R.  Accad. 
dei  Lined.  [5]  25,  i.  643  ;  see  dso  Richter,  Ber. 
1911,  44,  2155 ;  Johnson,  J.  Amer.  Chem.  Soc. 
1914,  36,  337). 

Alloxantin  is  readily  converted  into  murexide 
iq.v.)  by  the  action  il  ammonia,  into  alloxan 
by  mild  oxidising  agents,  and  into  dialuric 
acid  by  reducing  agents.  In  its  physiological 
action  alloxant^  resembles  alloxan,  but  is 
espedally  poisonous  to  cold-blooded  animals, 
the  blood  showing  strong  reducing  properties ; 
when  taken  internally  it  appears  in  tne  urine  as 

Sarabanic  acid,  and  in  smaller  quantities  as 
ialuric  acid,  murexide,  and  alloxantin  itself  (Ko- 
walewski,  Chem.  Zentr.  1887,  1296  ;  Susini,  Ann. 
Chim.  Farm.  1895,  21,  241 ;  1896,  22,  341,  385). 


Aedj/taBommUn  Ci«Hs0^a3,0,  obtained 
by  the  interaction  of  acaWf  dialuric  moid  and 
aUoxan,  ciystallises  in  thm  leaflets,  becomes 
anhydrous  when  kept  in  a  vacuum  over  sulphuric 
add,  melts  and  decomposes  at  263®-265  ,  and 
is  slowly  hvdrolysed  oy  hot  water  with  the 
formation  of  alloxantin. 

BemoylaOoxaniin  C,5HioO,N4,H,0,  simi- 
larly  formed  from  benzoyl  dialuric  add  and 
alloxan,  cr3rstallises  in  colourless  six-dded  plates, 
and  mdts  at  253®-255®  (Behrend  and  Friedrich, 
Annalen,  1906,  344,  1). 

Alloxantin  is  decomposed  when  boiled  in  an 
aqueous  solution  of  tne  hydrochloride  of  a 
primary  amine,  yielding  alloxan,  tooether  with 
the  corresponding  iAoffiJkifylbflkyZiifiuiis.  These 
are  colourless  crystalline  dibadc  adds,  hydrdyaed 
b^  boiling  with  aqueous  alkali  Inrdiozides  into 
dialuric  add  and  the  amine.  Dibarfniwyime- 
ine 

cx)<Si:S2>c<gM^c<^:Si>co 


^NHCO 


H  H-^^'^^CONH' 


decomposes  at  2S(f,  dibaffhturyldhf^amine  de- 
composes at  235®,  dibagfniurffiphenyhmine  be- 
comes blue  at  240®,  dibad^Uuryl'a-naiMifflamine 
becomes  black  at  260®,  the  corresponding  fi- 
compound  decomposes  at  260®,  and  i^arbituryl- 
carhaimide  C0(NH*C4H,0sNt)a  decomposes  above 
300®. 

The  following  homoloffnee  of  alloxantin  have 
been  prepared:  meihylaUoxanHn  CtHgOtN^, 
3H,0  from  methylalloxaa  and  dialuric  add 
(Andreasoh,  Monatsh.  1882,  3,  431);  ssrm- 
dimeOudaUoxantin  0,oHioO»N4,4HaO  from 
methyuJloxan  (Maly,  Andreasch,  Monatsh.  1882, 
3,  109),  wasm-dimelhylaUoxaiUin  CtoHioOaN^, 
HgO  irom  dimethyldialuric  add  and  sJloxan 
(Andreasch,  Monatsh.  1882,  3,  428).  Tetm- 
meihylattoxanHn  C]|H,^0,N4  ainalie  add  (from 
iLfia\6s  B  soft,  so  called  on  account  of  its 
feeblj^  add  reaction),  prepared  (1)  bv  oxidising 
caffeme  with  chlorine  or  nitric  add  (Rochleder, 
Annalen,  71,  1);  (2)  by  redudng  dimethyl- 
alloxan  with  sulphuretted  hydrogen  (Fiaoher, 
Ber.  1881,  14,  1912)  or  with  stannous  chloride 
(Andreasoh,  Monatsh.  1895,  16,  19) ;  (3)  from 
dimethyldialuric  add  and  dimethylaJloxan 
(Maly  and  Andreasch,  Monatsh.  1882,  3,  105) ; 
(4)  by  the  dectrolysis  of  cafidne  in  sulphuric 
add  solution  (Pommerehne,  Arch.  Pharm.  235, 
365).  See  BUtz  (Ber.  1912,  45,  3673)  for  the 
preparation  of  dimdhyl  and  tetnaneihylaUogMniin 
orom  theobromine  and  caflFdne  respectivdy. 
TetraethylaUaxarUin  Ci«H„0flN4,  obtained  by 
reducing  diethylalloxan,  melts  and  decomposes 
at  162®  (Sembritzki,  Ber.  1897,  80,  1821). 

M.  A.  W. 

ALLOXAZINE  v.  Alloxan. 

ALLOTS  V.  Metalloobafht. 

ALLTL.  A  univalent  radide  GgHg — ,  or 
CH,  :CHCH,— ,  isomeric  with  jpropenyil  CH,* 
CH :  CH<. 

Allyl  aceUte  CH,*CO,C,H(  boils  at  103®- 
104®/733*9  mm.  (Briihl),  and  has  sp.n.  0'9376  at 
0®  (SchifiF)-  It  is  only  slightly  soluble  in  water, 
and  has  a  rather  sharp  smell.  It  is  prepared 
by  the  action  of  allyl  iodide  on  silver  acetate 
(Zinin,  Annalen,  96, 361 ;  Cahours  and  Hofmann, 
Annalen,  102,  295  ;  Brohl,  Annalen,  200,  179  ; 
SchifF,  Annalen,  220.  109). 

Allyl  aeetlc  add  C,U|*CH.COtH  boiU  at 


AliLYL. 


149 


1  dT-l^y,  and  has  8p.gr.  0*98416  at  IS""  (Perkin). 
It  is  Blightly  BoluDla  in  water  and  ita  smell 
wemblBB  that  of  valerianic  acid.  It  is  unaffected 
l^  lednction  with  sodium  amalgam,  but  readily 
unites  with  two  atoms  of  bromine.  It  is  prepared 
by  hydrolysing  allyl  acetoaoetio  acid  etnyl  ester 
with  dry  sodium  ethoxide,  or  by  heating  allyl 
roalonie  acid  (Zeidler,  Annalen,  187,  39 ;  Conrad 
and  Bisohoff,  Annalen,  204,  170 ;  Henry,  Chem. 
Zentr.  1898,  u.  663). 

The  chloride  OtEt'CR^'CiOCi  is  a  thick, 
pungent-smelling  B3rrup,  boilW  at  128^/766  mm., 
and  of  sp.gr.  1*^39  at  16®  (J&nry,  leX 

AOylaeelone  CH,-CX)-0H,*G,H5  boils  at 
128'*-130<',  and  has  8p.gr.  0*834  at  27^  It  is 
an  unpleasant-smelling  liquid.  It  forms  an 
amorphous  compound  with  sodium  bisulphite, 
and  IS  reduced  by  sodium  amalgam  to  hexenyl 
alcohol.  It  is  prepared  by  hydrolysing  allyl 
aoetoacetic  acid  etnyl  ester  (70  grams)  with 
crystalliaEed  baryta  (215  grams)  and  water 
(1660  o.c.)  (Zeidler,  Annalen,  187,  36  ;  Merlins, 
Annalen,  264,  323).  Treated  with  hydroim- 
amine  it  yields  aUylaeetoxime  CH,*C( :  NOH)*CHa* 
CaHg,  which  is  a  liquid  boiling  at  188**  (corr.), 
soluble  in  alcohol,  oenzene,  ether,  acids  and 

ADyl  aleohol  GJE,OH,  i.e. CHs:0H>CH,'OH 
occurs  in  raw  wood  spirit,  but  only  to  the  extent 
of  about  012  p.o.  (Aronheim,  Ber.  1874,  1381 ; 
Grodzki  and  Kramer,  ibid.  1492).  It  is  a 
pungent  liquid  with  a  burning  taste,  and  mixes 
rea<Oly  witn  alcohol,  water,  or  ether.  It  boils 
at  96-6*  (corr.),  and  has  sp.gr.  0*87063  at  O""  and 
0-8573  at  16715**  (Thorpe,  Chem.  Soc.  Trans. 
1880,  208),  Do  0*86929,  and  b.p.  96*95''  (Wallace 
and  Atkins,  Chem.  Soc.  Trans.  1912,  1183). 

It  is  prepared  by  slowly  distilling  glycerol 
(400  parts)  with  orystalliBed  oxalic  acid  (100 
parts)  and  a  little  ammonium  chloride  (1  part) 
to  convert  any  potassium  oxalate  into  chloride. 
He  receiver  is  changed  at  190**  and  distillation 
continued  up  to  260^  It  is  usually  stated  that 
the  allyl  alcohol  is  produced  by  the  decomposi- 
tion of  monoformin,  out  according  to  Chattaway, 
the  chief  source  is  the  norm^  oxalic   ester 

CH, CH*CH,OH, 

dioxalin        I  I  which  on 

0'CO-CO*0 
heating  is  resolved  into  carbon  dioxide  and 
allyl  ucohol  (Chattaway,  Chem.  Soc.  Trans. 
1914,  105,  151;  ibid.  1915,  107,  407).  The 
distillate,  containmg  aqueous  allyl  alcohol,  allyl 
formate,  acrolein,  and  glycerol,  is  rectified  and 
dried,  first  with  potassium  carbonate,  then  over 
solid  potash  and  distilled.  Whea  the  last  traces 
of  water  are  removed  by  quicklime  it  boils  at 
96-6^  The  yield  is  one-sixth  of  the  weight  of 
oxalio  add  taken  (ToUens  and  Henninfler,  Bull. 
Soo.  ohim.  [2]  9,  394;  Bruhl,  AnniSen,  200, 
174;  Tannemann,  Ber.  1874,  854).  Further 
purifioation  may  be  effected  by  proloosed 
nnftting  with  sodium  bisulphite  and,  alter 
removal  of  the  bisulphite,  redistilling  several 
times  from  quicklime  (Thorpe). 

According  toKoehler  (Bull.  Soc.  chim.  1913, 
[iv.]  13,  1103)  the  yield  of  allyl  alcohol  may  be 
increased  from  20  to  32  p.c.  by  replacing  the 
oxalio  acid  by  formic  add.  100  grams  of 
fflyoerol  are  heated  with  80  grams  of  formic  acid 
for  an  hour  on  a  water-bath  and  the  product 
Iraotiooally   distilled   and   collected   in   three 


fractions:  (1)  up  to  200**;  (2)  200**-260** ;  (3) 
residue.  The  saponification  index  of  fraction 
(2)  is  determined,  and  it  is  then  poured  on  to 
twice  the  calculated  amount  of  solid  potassium 
hydroxide.  The  whole  is  boiled  for  an  hour, 
aUowed  to  cool,  and  the  top  layer  decanted  and 
dried  over  anhydrous  potassium  carbonate. 
The  intermediate  product  is  monoformin. 

According  also  to  Hoff  (K.  Danske  Videnskab. 
Selskab.  Forhand.  1915,  199)  the  most  satis- 
factory method  of  preparing  allvl  alcohol  con- 
sists m  the  direct  reouotion  of  glycerol  with 
formic  acid.  825  grams  of  97  p.c.  glycerol  and 
84*2  grams  of  95  p.o.  formic  add  (mol.  props. 
5 : 1)  are  heated  together  in  a  retort ;  the 
recdver  is  changed  at  200**,  and  the  distillate 
collected  between  200**  and  250**.  After  cooling  a 
furt|ier  quantity  of  165  ^ms  of  elvcerol  and 
84*2  grams  of  formic  acid  is  ad£a,  snd  the 
distilmtion  carried  out  as  before.  This  process 
LB  repeated  ten  times.  From  the  distillate 
between  200**  and  250**,  which  weighs  about 
1470  grams,  allyl  alcohol  is  obtamed  alter 
treatment  with  potasdum  carbonate,  the  yidd 
being  about  54  p.c.,  calculated  dther  with 
respect  to  the  glycerol  or  the  formic  add  (Chem. 
Soc.  Abstr.  1916,  i.  6). 

Allyl  alcohol  is  oxidised  by  chromic  acid 
solution  to  acrolein  and  formic  add ;  and  by 
dilute  nitiio  add  to  formic  and  oxalic  adds ; 
whilst  potasdum  permanganate  juroduces  acrolein, 
glycerol,  and  formic  acicL  It  combines  directly 
with  ohlorine,bromine,  iodine  chloride,  and  cyano- 
gen, producing  additive  products.  It  is  partially 
reduced  by  boiling  for  some  hours  with  zinc  and 
dilute  sulphuric  add  to  n-propyl  alcohol. 
Potasdum  displaces  the  hydrox^Uc  hydrogen 
atom  and  forms  gelatinous  potassium  allylate. 

Denig^  (Bufl.  Soc.  chim.  1909,  5,  878) 
describes  the  following  colour  reactions  for  the 
detection  of  iJlyl  alcohol,  depending  on  the 
formation  of  (1)  glyceraldehyde  and  (2)  di- 
hydroxyacetone  and  the  condensation  of  these 
products  with  various  reagents.  Bromine 
water  (0*6  c.c.  in  100  c.c.  water)  is  added  to 
0*1  c.c.  of  allyl  alcohol,  till  a  slight  permanent 
colouration  is  produced,  and  the  liquid  is 
then  1X)iled,  cooled,  and  divided  into  portions 
of  0*4  C.C.  To  each  of  these  0*1  c.c.  of  a  5  p.c. 
solution  of  codeine,  resordnol,  thymol,  or  fi- 
naphthol  is  added,  followed  by  2  o.c.  of  sulphuric 
acid  (sp.gr.  1*84)  and  the  mixture  wanned 
during  3  or  4  minutes  at  100^.  Codeine  and 
thymol  give  reddish-violet  colourations,  resor- 
dnol wine-red,  and  iS-naphthol  yellow^  with 
greenish  fluorescence.  The  second  series  of 
colour  reactions  is  obtained  by  adding  to  the 
brominated  liquid  above  described  5  c.c.  of 
bromine  water  (0*6  c.c.  in  100  c.c.  water), 
heating  during  20  minutes  at  100**,  then  boiling 
to  remove  excess  of  bromine  and  cooliiu;.  This 
liquid  contains  dihydroxyacetone,  and  in  the 

Sresence  of  concentrated  sulphuric  acid  gives  a 
eep-blue  colour  with  codeine,  orange-rea  with 
resordnol,  blood-red  with  thymol,  or  green  with 
green  fluorescence  with  i3-naphthol  (Denigbs, 
Compt.  rend.  148,  172,  and  282). 

Bromine  is  quantitativdy  absorbed  by  allyl 
alcohol,  whether  the  former  is  in  excess  or  not, 
and  the  reaction  is  suitable  for  the  exact 
quantitative  estimation  of  the  alcohol,  which 
may  be  effected  dther  by  direct  titration  with 


100 


ALLYL. 


bromine  water  until  a  permanent  yellow  coloura- 
tion iM  obtained,  or  by  treating  the  acidified 
aqueouB  solution  of  the  alcohol  with  an  jexcess 
of  bromide-bromate  solution,  followed  by 
addition  of  potassium  iodide  and  titration  of 
the  liberated  iodine  with  sodium  thiosulphate 
(Stritar,  Monatsh.  1918.  39,  617). 
AUylamines. 

MonoaUylamine  OgH.'NH,  is  a  liquid  boiling 
at  53-3*  and  of  sp-gr.  0*7799  at  4*  and  0-7688  at 
15*  (Perkin.  Ghem.  Soa  Trans.  1889,  697) ;  b.p. 
68*  and  Bp.gr.  0-864  -at  15*  (Rinne,  Annalen, 
168,  262) ;  b.p.  56*-^-5*/756-2mm.  (SohifF,  Ber. 
1886,  565).  It  is  prepared  from  allyl  ijooyanate 
and  .potash,  or  from  allyl  iodide  and  ammonia, 
or  by  reduction  of  alljl  mustard  oil  with  siiic 
and  hydrochloric  acid  (Oeser,  Annalen,  134,  8).  It 
possesses  a  penetrating  smeU,  which  excites  tears 
and  DToduces  sneezing.  It  is  miscible  with  watei 
in  all  proportions,  and  is  a  strong  base,  forming 
a  orystalUne  platinichloride  (CaH,-NH,),Ptac, 
and  sulphate  (C,H.-NH.),H,S04.  The  hydro- 
chloride  melts  at  105M10*  (Del6pine,  Bull. 
Soc.  chim.  [3]  17,  294)  and  the  picrate  at 
140*-141*  after  sintering  (Gabriel  and  Eschen- 
bach,  Ber.  1807,  1125). 

DiaOylamine  (C.H.),NH  boils  at  11I<>  and 
is  prepared  from  allylamine  and  allyl  bromide 
(Ladenburg,  Ber.  1881,  1879 ;  Liebermann  and 
Uagen,  Ber.  1883,  1641). 

TrtaUylamine  (C,H(),N  is  a  very  unpleasant- 
smelljng  liquid,  boiling  at  150M51*  (Pinner,  Ber. 
1879,  2054) ;  155*-156*,  sp.gr.  0-8094  at  14-3* 
(Zander,  Annalen,  214,  151).  It  is  prepared  by 
distilling  tetrallylammonium  bromide  with  large 
excess  of  recently  fused  potash  (Grosheintz, 
BulL  Soc.  ohim.  [2]  31, 391)  or  from  allyl  chloride 
and  alcoholic  potassinm  cyanide  in  the  cold 
(Pinner,  Lc);  or  from  allyl  chloride  and  am- 
monia (Malbot,  BulL  Soa  chim.  [2]  50, 90).  It  is 
displaced  from  its  aqueous  solution  by  potash, 
ana  forms  a  orysUdline  platinichloride  and 
hydrochloride. 

TetraUylammonium  bromide  (C,H,)4NBr  is  a 
crystalline  solid,  soluble  in  alcohol  and  water, 
but  only  slightly  so  in  ether.  It  is  prepared  by 
leading  a  stream  of  ammonia  into  an  alcoholic 
solution  of  allyl  bromide.  The  product  is  puri- 
fied by  recrystaUisation  from  alcohol  containing 
a  little  ether  (Grosheintz,  Bull.  Soc.  chim.  [2]  31, 
390).  Treated  with  moist  silver  oxide  it  yields 
tetrallylammonium  hydroxide. 

TeiraUvlammonium  iodide  (CtH,)4NI  is  the 
main  product  of  the  reaction  of  allyl  iodide  od 
ammonia  at  the  ordinary  temperature  (Cahoura 
and  Hofmann,  Annalen,  102,  305 ;  Malbot,  Ann. 
Chim.  Ph vs.  [6]  13,  488).  It  is  a  crystalline 
solid,  insoluble  in  strong  potash  solution. 

AllylJUiiUne   C,H.-NHC,H.   is  a  yeUow  oU 

froduoed  by  the  action  of  allyl  iodide  on  aniline. 
t  boils  at  208*~2U9*  and  has  sp-gr.  0-982  at  25* 
(Schi£f,  Annalen  SuppL  3,  364). 

DiaUylaniUne  cJh.-N(C,H^),  is  prepared  by 
adding  allvl  bromide  (1  mol.)  to  aniune  (1  mol.) 
in  a  flask  fitted  with  reflux  condenser,  separating 
the  allyl  aniline  by  the  addition  of  potash,  ana 
converting  it  into  diallyl  aniline  bv  repeating 
the  process  with  more  allyl  bromioe  (1  moL). 
It  boils  at  243-5*-245*,  and  has  sp.gr.  0-9538  at 
19-8*  (Zander,  Annalen,  214,  149). 

Allyl  btnMM  C«H.CH,-CU.-CH,  is  obtained 
by  heating  together  benzene,  allyl  iodidt  aod 


zinodust  to  100*  (Ghojnacki,  J.  1873,  569; 
Fittig,  Annalen,  172,  312).  It  boils  at  ISS"*. 
The  iBomisno  propenyl  benzene  (and  phenyl 
propylene— OftHc'CH :  CH'GH.)  is  sometimes 
mcorrectl  V  referred  to  as  allyl  oenzcno. 

AUyl  bromide,  monobrompropykne  CH,:CH- 
CH,Br,  boils  at  70M1*,  and  has  sp.gr.  14336 
at  17*  (Zander,  Annalen,  214,  144);  b.p.  70*5* 
(corr.)  (Thorpe).  It  is  formed  by  the  action 
of  phosphorus  tribromide  on  allyl  alcohol,  and 
is  prepiued  by  dropping  all^l  alcohol  into  a  hot 
solution  of  potassium  bromide  in  sulphuric  add 
(1  vol.  acid  to  1  vol.  H,0)  according  to  Gros- 
heintz (Bull.  Soc.  chim.  [2]  30,  78);  or  by 
saturating  allvl  alcohol  with  hydrogen  bromi<w 
at  0*  ana  suDsequently  heating  to  boiling  for 
several  hours  ( Jacobi  and  Merling,  Annalen,  278, 

11). 

Allyl  bromide  absorbs  hydrogen  bromide  in 
bright  light  forming  trimethylme  bromide ;  in 
the  dark  propylene  bronude  is  also  produced 
(Holleman  and  Matthes,  Proa  K.  Akad.  WeL 
Amster.  1918,  21,  90). 

Allyl  ehloride  GH,:CH*CH.G1  boib  at  46*, 
and  has  8p.gr.  0*9547  at  0"^  (ToUfins,  Annalen, 
156, 154) ;  0-9371  at  19*3*  (Zander,  Annalen,  214, 
142) ;  b.p.  45-29*  (corr.)  (Thorpe).  It  is  pre- 
pared by  the  action  of  mercuric  diloride  on  ulvl 
iodide,  or  from  allyl  oxalate  calcium  chloride 
and  alcohol  at  100*  (Oppenheim,  Annalen,  140, 
205) ;  or,  best,  by  heating  allyl  alcohol  and 
concentrated  hydrochloric  acid  to  100*  for  some 
hours  (Eltekow).  It  combines  with  hydrogea 
chloride  to  form  propylene  chloride  CaHcCl,, 
and  with  fuming  hydrobromic  acid  yielding 
1  -chloro-3-bromopropane  GH,C1*CH.*GH ^Br. 

AUyl  eyaoamUa,  einamine^  GgHl-NH-GN,  is 
produced  by  warming  allyl  thiooarbanude  with 
lead  hydroxide  on  the  water-bath  (Will,  Anna^lftn^ 
52,  15).  On  standing  for  some  months  crystals 
separate  from  the  resulting  product.  It  is  pre- 
pued  by  shaking  an  aqueous  solution  of  allyl 
thiocarbamide  with  mercuric  oxide  until  the 
solution  no  longer  blackens  ammoniacal  silver 
nitrate  (AndretMoh,  Monatsh.  2,  780).  It  is 
alkaline  in  reaction,  precipitating  metallic  oxides 
and  replacing  ammonia  in  its  salts.  The  crystals 
contain  iH,0  and  melt  at  100*,  giving  up  their 
water.  It  forms  a  difficultly  crystaUisaole  salt 
with  oxalic  acid,  but  not  with  other  acids,  and 
double  compounds  with  mercuric  and  platinic 
chlorides. 

Allyl  cyanide,  croUnwniirile.  G,H,-GN,  boils  at 
119*  (corr.),  and  has  sp.gr.  0-8491  at  0*  and 
0-8351  at  15*.  It  is  obtained  by  the  action  of  allyl 
iodide  on  potassium  cyanide,  and,  together  with 
other  products,  by  allowing  allyl  mustard  oil  to 
remain  in  contact  with  water  for  some  weeks, 
and  also  by  the  action  of  acetic  anhydride  on 
crotonaldoxima  It  has  been  prepared  by  Henry 
(Chem.  Zentr.  1898,  ii,  662)  by  the  action  of 
phosphorus  pentoxide  on  a-  or  /3-hydroxy-bu- 
tyronitrile.  It  is  a  liquid  with  an  unpleasant, 
onion-like  smelL  On  warming  to  50*-^90*  with 
fuming  hydrochloric  acid  for  two  hours,  ohloro- 
butyric  acid  is  produced.  Ghfomio  acid  oxidises 
it  to  acetic  acid,  nitric  acid  to  oxalic  acid. 

AUylenes.  Two  allylenes  are  possible  and 
known :  symmetrical  allylene  GH,:G:CH„ 
and  unsymmetrical  allylene  GU^-GiGH. 

Symmatrieal  allylene,pr(»}cui»ene,  GH. :  C  :GH^ 
is  a  gas  which  bums  with  a  sooty  luminous 


ALLTL. 


161 


ftune.  It  is  prepared  by  dropping  a-bromoallyl 
bromide  (10  Lrams)  into  a  mixtoie  of  20  grama 
zinc-diut  and  25  grams  alcohol  (70  p.o.)  (Gns- 
taTwm  and  Demjanow,  J.  pr.  Chem.  [2]  38,  202). 
It  does  not  precipitate  ammoniacal  solutions  of 
BuLver  nitrate  or  cuprous  chloride.  It  is  readily 
absorbed  by  strong  sulphuric  acid,  and  acetone 
is  produced  on  dilution.  When  dissolved  in 
abs<dute  ether  and  heated  with  sodium  to  100^, 
it  changes  into  the  isomeric  methyl  acetylene. 
It  readily  forms  a  tetrabromide  GsH^Br^  by 
addition  of  bromine. 

Unsymmetrieal  allylene,  methyl  acetylene 
GH,C:CU,  results  from  propyl^e  bromide, 
monobromopropylene,  or  monochloropropylene 
hv  withdrawal  of  HCl  or  HBr  by  means  of 
alooholio  potash,  and  from  symmetrical  allylene 
(r.  tupra).  It  is  an  unpleasant-smelling  gas, 
which  is  liquefied  under  a  pressure  of  3-4 
atmospheres.  It  bums  with  a  bright  sooty 
flame.  It  dissolves  readily  in  ether  (30  vols,  in  1 
of  ether  at  16**).  Potassium  permanganate  in 
the  cold  oxidises  it  to  formic,  oxalic,  and  malonic 
acids.  Explosive  compounds  are  produced  by 
leading  it  into  ammoniacal  solutions  of  silver 
nitrate  or  cuprous  chloride.  Goncentrated  sul- 
phuric acid  readily  absorbs  it,  forming  on  dilution 
and  distillation  acetone  mesitylene  and  allylene 
solnhonic  acid  G,H,;BO,H  (Schrobe,  Ber.  1876, 18 
via  367).  The  6anttmsai!t  of  the  latter  is  crystal- 
line, eaedly  soluble,  and  not  decomposed  on  boil- 
ing with  water.  CJ,  Acetylenb  :  bomologi  e-^  of. 

AOyl  ether  G.H,0'G,Hc  boils  at  94-3''  and 
has  8p.gT.  0-8046  at  18*".  It  is  prepared  from 
allyl  iodide  and  sodium  allyl  alcoholate,  or  from 
allyl  iodide  and  mercuric  oxide  (Cahours  and 
Uofmann,  Annalen,  102,  290;  Berthelot  and 
Laca,  AniL  C:ihim.  Phys.  [3]  48,  291). 

Allyl  ethyl  ether  (3,H»'0G,H»  boils  at  66''- 
67''/742'9  mm.  (Bruhl,  Annalen,  200,  178).  Pre- 
pared  from  allyl  iodide  and  sodium  ethoxide. 

AOyl  Iodide  G|H»1  boils  at  102*79''  (corr.) 
(Thorpe  and  Rodger),  and  has  sp.gr.  1*8696 
(fl^f,  Berthelot  and  Luca  (Ann.  Chim.  Phys. 
[3]  43,  267)  obtained  it  by  the  action  of  PI,  on 
glyoeroL  It  may  be  prepared  by  leaving 
together  for  24  hours  red  phosphorus  (20  grams), 
alfyl  alcohol  (160  grains),  and  iodine  (264  grams) 
(Tollens  and  Henninger,  Annalen,  166,  166) ; 
or  by  the  following  procesa:  100  frams  of 
iodine  and  16(X)  grains  of  carefully  dehydrated 
glycerol  are  brought  together  in  a  large  vessel, 
the  air  displaced  by  a  current  of  carbon  dioxide, 
and  300  g]nun*  of  ordinary  phosphorus  gradually 
added.  The  allyl  iodide  is  distilled  off  in  a 
stream  of  carbon  dioxide,  and  then  contains 
as  impurity  some  isopropyl  iodide.  According 
to  Rasik  Lai  Datta  (J.  Amer.  CSiem.  Soo.  1914, 
36,  1<X)6)  the  use  of  carbon  dioxide  is  un- 
neoeasary.  To  purify  it,  it  is  dissolved  in 
alcohol  and  shaxen  with  mercury,  when  the 
compound  HgG«H«I  is  precipitated.  This  is 
recrystallised  from  wat^  and  decomposed, 
regenerating  allyl  iodide,  by  distillation  with 
water  and  the  theoretical  quantity  of  iodine 
(Linneinann,  Annalen  Suppl.  3,  263).  It  com- 
bines with  bromine  to  form  tribromhydrin,  and 
with  hydriodio  acid  to  give  diiodopropylene. 
By  long  heating  with  about  20  parts  of  water  it 
is  converted  into  allyl  alcohol  and  hydriodicacid. 

Allyl  mereiptan  G^HJSH  boils  at  90^ 
With  mercQzic  chloride  it  yiekb  GaH|SHg€3, 


which  crystallises  from  alcohol  in  plates  (Hof- 
mann  and  Cahours,  Annalen,  102,  292 ;  Gerlich, 
Annalen,  178,  88). 

Allyhnethybd  Mothloeyanate  is  the  name 
given  to  the  compound  C,H.O'SGH,*GN,  pre- 
pared  by  passing  a  current  of  formaldehyde  gas 
through  gIvceror(l  kilo)  and  allyl  isothiocyanate 
(6  grams)  heated  to  190''  until  the  weight  of  the 
whole  is  1400  grams.  When  cool  the  product 
is  filtered  and  the  resulting  methylal  wothiooya- 
nate  used  as  an  antiseptic  (Plot,  Fr.  Pat.  330988, 
1903). 

Allyl  mustard  oil  v.  Mustabd  oil  and  Essih- 

TIAL  OILS. 

Allyl  nitrite  G,H,NO,  la  obtamed  by  adding 
glycerol  trinitrite  to  ice-cold  allyl  alcohol  ana 
cautiously  distilling  off  the  aUyl  ester  (Bertoni, 
Gazz.  chim.  itaL  16,  364).  It  boils  at  43*6''- 
44-6*,  and  has  sp.gr.  0*9646  at  0*.  It  is  readily 
decomposed  by  sluiking  with  water,  and  yielcis 
ethyl  nitrite  on  treatment  with  ethyl  alcohol. 

AUyl-phenyl-thloiireA  SG<^q!^^*  may  be 

prepared  from  aniline  and  mustard  oil  (Zinin, 
Annalen,  84,  348);  or  from  allylamine  and  phenyl 
mustard  oil  (Weith,  Ber.  8,  1629).  It  forms 
monoclinio  crystals,  melting  at  98*,  and  is 
readily  soluble  in  ether,  but  not  in  water. 

Allyl  pyrrol  G4H4NC,H,  is  readily  obtained 
by  the  action  of  allyl  bromide  on  potassium 
pyrrol  in  ether  (Ciamician  and  Oennstedt,  Ber. 
1882,  2681).  It  is  a  light-yellow  oU,  turning 
brown  on  exposure  to  air.  It  boils  at  105^48  mm. 
It  is  insoluble  in  water,  but  dissolves  in  UCl, 
producing  a  red  colour. 

Allyl  sulphate  G,H,'HSO«  is  prepared  by 
adding  allyl  alcohol  (1  voL)  to  sulphuric  acid 
diluted  with  ita  own  volume  of  water  (I  voL), 
and  leaving  at  ordinary  temperatures  for  five 
davs.  Sulwequently  the  mixture  is  heated  to 
70*  for  12  hours,  diluted  with  water  (10  vols.), 
and  saturated  with  barium  carbonate  (Szyman- 
ski,  Annalen,  230,  44 ;  v.  also  CSahoura  and 
Hofmann,  Annalen,  102.  293).  It  forms  cha- 
racteristic salts,  a  number  of  which  are  described 
by  Szymanski  (I.e.). 

AUyl  sulphide,  oU  of  garlic,  (Grer.  KnMau- 
ehOl)  (G,H,)2S>  occurs  in  garlic  (AUium  sativum) 
and  other  plants.  It  is  prepared  from  mustard 
ofl  and  potassium  sulphide  at  lOO''  (Wertheim, 
Annalen,  66,  297) ;  or  from  allyl  iodide  and 
potassium  sulphide  (Hofmann  and  Gahours, 
Annalen,  102,  291 ).  It  is  a  liquid  boiling  at  1 38-6*, 
and  has  sp.gr.  0-88766  at  26-874''.  It  has  a  very 
atronff  odour  of  garlic  and  ia  only  slightly 
aolnble  in  water. 

Allyl  thloearbamlde,  aUyl  thiowea,  (Aumi no- 

mine,  *BhodaUin '  80<^j^^  -q   ,  is  produced 

by  the  prolonged  action  of  aqueous  ammonia 
on  mustard  od  (Dumas  and  Pelouze,  Annalen, 
10,  326).  It  forms  clear  six-sided  tables,  which 
melt  at  78-4*,  after  smtering  at  71*.  It  ia 
insoluble  in  benzene,  sparingly  soluble  in 
water,  and  readily  so  in  alcohol  and  ether.  It 
combipea  directly  with  halogens,  cyanogen, 
ethyl  iodide,  acids,  Ac.  Deprived  of  its  sulphur 
by  mercuric  oxide,  or  lead  oxide,  it  yields  nna- 
mine  (allyl  cyanamide)  CjHj-NH-GN.  It  has  been 
need  in  surgery  for  the  removal  of  soar  tissue. 


152 


ALLYL. 


being  injeoted  m  *  10  or   16  p.c»  solution   in 
diluto  diyooroL 

AO^  tllbromlde^  «  Tnbramhydrin '  C.H,Br., 
WM  obtained  by  Wurtz  by  treating  allyl  iodide 
with  bromine^  and  by  Berthebt  and  Lnoa  by 
the  action  of  phoBphonu  tri*  and  pentabro- 
mides  on  glycefoL  It  is  a  ali^tly  yellow  liquid 
of  8p.gr.  2*430  at  15•6^  and  boib  at  217*.  It  is 
a  strong  eedatiye  and  anodyne. 

Allyl  UTM  00<j^^^      oiystalliM   in 

needles,  melting  at  80*  (Oahouia  and  Hofmann, 
Annalen,  102,  299 ;  Andreasoh,  Monatsh.  6,  36). 

J.  A.  P. 

AIJIA80A.  A  soft  grey  resin  soluble  in 
chlorofonn,  ether,  and  aDsolute  aloohol.  Pro- 
bably derived  from  the  burseraoeons  Protiutn 
heptaphyUum  (March.)  [Idea  hepUiTphyOa  (Anbl.)] 
(Symes,  Phaim.  J.  [3]  13,  213). 

ALMATEIN.  Trade  name  for  a  condensa- 
tion prodoct  of  hematoxylin  and  formaldehyde. 
Usea  as  an  antiseptic 

AUflRAO.  Indian  name  for  Launaaa  pinna- 
tifida  (Cass.)  Mkrorhfmckm  sarmentoaus  (DC) 
which  belongs  to  the  family  CompoeitflB  and  is 
used  at  Goa  as  a  substitute  for  taraxacum 
(I)ymock,  Pharm.  J.  [3]  6,  730). 

ALMOHD.  The  kernel  of  the  fruit  of  Prunui 
amygdahu  or  Amygdahu  comm/wni9. 

Two  principal  yarieties  exist — the  sweet  and 
the  bitter  almond.  Both  contain  amygdalin, 
but  the  latter  is  much  richer  in  this  substance 
(2  to  3  p.c.),  and  contains  an  enzyme,  fmuMi, 
which,  in  the  presence  of  water,  decomposes  the 
amygdalin^  yielding  glucose,  benzaldehyde,  and 
hydxooyanic  add 
Cr,oH,^On+2H,0 

=C^,CH0+HCN+2C.Hi,0. 
In  addition,  almondJB  contain  about  50  p.a  of 
their  weifht  of  a  fixed  oil  (mainly  oleln,  and 
liable  to  oecome  rancid)  and  smaller  quantities 
of  proteins,  susar,  staioh,  gum,  fibte,  and  ash. 

Analyses  ox  almonds  made  at  various  stsges 
of  growth  and  ripening,  show  the  percentage  of 
amyloses,  glucose,  and  saccharose  to  steadilv 
diminish,  whilst  the  proportion  of  oil  increases 
(Du  Sablon,  Compt.  rend  1896,  123,  1084). 

According  to  Valine  (Ck>mpt.  rend.  1903,  136, 
[2  J 114),  reducing  sugars  in  the  immature  almond 
decrease  as  the  fatty  oil  increases;  sucrose 
increases  until  oil  -  formation  begins,  then 
decreases  during  oil-production,  and  towards  the 
end  asain  increases.  Ripe  almonds  contain 
about  3  p.c.  of  sucrose.  According  to  Osborne 
and  CJampbell  (J.  Amer.  Ghem.  Soc.  1896,  18, 
600),  the  protein  in  almonds  is  amandin  and  not 
conglutin  or  ritellin.  H.  I. 

ALMOND  OIL  is  obtained  from  the  seeds 
of  iVttfitM  amygdalua  (Stokes)  [Amygdalus 
eommuni9  (Linn.)].  The  almond  tree  appears  to 
have  been  indigenous  to  Turkestan  and  Middle 
Asia,  and  has  been  transplanted  from  there  to 
Greece,  Italy,  Spain,  France,  and  to  Northern 
Africa.  The  mean  percentage  composition  of 
the  almond  is  given  by  Konig  as  follows : — 

Oil 41-00  p.  c. 

Water 2772   „ 

Proteins 16-60  „ 

Sxtraoted  matter,  free  from  nitrogen  10*20 
Oude  fibre  ....  2*81 
Ash 1-77 

100-00 


M 
ff 


The  commercial  oil  is  chiefly  expressed  from 
bitter  almonds,  the  seeds  of  Prunua  amj/odalus, 
▼ar.  amofu.  Bitter  almonds  «n«»A^»i,  beaides 
the  oil,  amygdalin  and  Amnlain  which  give 
rise  to  the  formation  of  benzaldehyde,  dextrose, 
and  hydrocyanic  add.  Hence  the  press-cakes 
from  almonds  find  a  profitable  outlet  in  the 
manufacture  of  genuine  '  ethereal  bitter  almond 
oil,'  which  is  prepared  by  triturating  the  meal 
with  water. 

Sweet  almonds  (from  Pruniu  amygdaius, 
var.  duicis)  are  but  rarely  uied  alone  for  the 
preparation  of  almond  oiL  Mogador  hifeter 
almonds,  which  are  chiefly  used  in  this  couivtiy 
for  the  manufacture  of  almond  oil,  are  always 
more  or  lass  mixed  with  sweet  *Ji*i^"5^a  Sweet 
almonds  yield  from  44  to  55  p.o.  of  oil,  bitter 
almonds  yield  less  and  may  contain  as  low  a 
proportion  of  oil  as  20  p.c.  On  an  average, 
however,  bitter  almonds  yield  from  38  to  45  p.c. 
of  oiL 

TheoilispaleyeUow;  it  has  a  Terv  pleasant, 
mild  taste,  and  is  almost  free  from  odour.  The 
specific  gravity  of  the  oil  varies  from  0*915  to 
0-9195  at  15^  The  oU  becomes  turbid  at  -10°, 
and  solidifies  at  —20°,  has  the  saponification 
value  of  the  majority  of  oils  which  are  free  from 
volatile  adds,  and  an  iodine  value  of  93-100. 
Famstdner  (Zdtsch.  Nahr.  Gtonussm.  1890, 
2,  1)  separated  linoOc  tetrabzomide  in  a  pro- 
portion corresponding  with5'97  p.c.  of  linblio  add, 
and  it  is  probable  that  other  spedmens  may 
contain  up  to  about  10  p.c.  of  that  add.  The 
other  fatty  adds  consist  mainly  of  <ddc  add, 
with,  at  most,  traces  of  saturated  fatty  adds. 

Almond  oil  is  ohiefiy  used  in  pharmaceutical 
practice.  Owing  to  its  high  price  it  is  largely 
adulterated  witii  other  oils  of  the  PtMnue 
family,  chiefly  with  apricot  kernel  oil,  from 
Prunus  armeniaea  (Linn.),  and  with  peadi  kernel 
oil,  from  Prunus  perHea  (Sieb.  et  Zucc.).  These 
two  oils  are  very  similar  to  a3ninn4^  oil,  but  have 
a  less  pleasant  taste.  Thev  are  used  to  such 
an  extent  as  adulterants  tnat  freauentiy  th^ 
completely  take  the  place  of  almona  oil ;  indeed 
'  foreign  *  almond  oil,  or  *  oil  of  sweet  almonds, 
French'  {Oleum  amyydcdarum  gaUicum),  is 
nothins  else  than  a  mixture  of  apricot  kernel 
oil  ana  peach  kemd  oil.  Genuine  almond  oil 
is  sold  in  commerce  under  the  name  *  almond  oil, 
English.' 

The  dose  relationship  in  which  apricot  and 
peach  kernel  oils  stand  to  almond  oil,  rendan 
their  detection  in  almond  oil  a  difficult  problem. 
The^  differ  from  almond  oil  in  sometimes 
havmg  a  higher  iodine  value  (96-108),  and  a 
higher  critical  temperature  of  solution  {f,g. 
almond  oil,  32''-33'5'';  apricot  kemd  oil, 
46''-47'';  and  peach-kemd  oil,  41'').  Of  various 
colour  reactions  that  of  Bieber  (Zeitsch.  cuial. 
Ghem.  1878,  17,  264)  is  the  best  known.  It 
depends  on  the  different  colourations  given  by 
the  three  oils  when  shaken  with  a  mixture  of 
strouff  sulphuric  and  nitric  adds  and  water. 
The  onromoffenic  substance  in  apricot  kemd  oil 
is  not  volatito  with  steam,  and  the  test  is  capable 
of  detectizig  5  p.a  of  that  oil  in  «^i«ond  oil 
(Ross  and  Race,  Analyst,  1911,  36,  263). 

ALMOMDS,  BiTTKB,  Eseential  <nlof{v.  Ban- 

ALDEHYDE  ;    sJsO  OiLS,  ESSENTIAL). 

ALOE.  A  genus  of  succulent  plants,  having 
stiff,  pointed,  fleshy  leaves,  bdonging  to  the 


ALOES. 


16S 


Ldiaoex.  (Pluita  figund,  and  straoturd  of 
Imtw  described,  Penneiier,  660,  679.)  Of  the 
86  qpeoies  60  aie  nativee  of  Cuw  Colonv,  and  the 
otber  q>ecie8  are  nudnly  lub-tropical  African, 
though  a  few  ooeiir  in  the  tropios ;  a  number  of 
npeoiea  have  been,  however,  introduced  into  the 
Weet  and  East  Indies.  (For  a  list  of  the  speeies 
and  thsir  distribution,  v.  Pharm.  J.  [i]  11, 
746.) 

Tha  fibre  is  used  for  rope^  Ac ;  experiments 
made  in  Paris  have  shown  it  to  be  five  times  as 
strong  as  hemp.  The  fibre  has  also  been  used 
for  paper.makugJNat.  20,  484). 

AUB-EHOmll  o.  Rhubaiui. 

ALOB  BESmS  V.  Alobs  ob  Bittbb  alobs. 

ALOBS  or  BITTEB  ALOES.  (Alo^,  Ft. ; 
AJoe^  Ger. ;  iilos,  6.P. ;  U.S.P.).  The  inspis- 
sated juioe  or  extraot  of  the  sloe.  Slow  oon- 
ceatntion  induoes  crystallisation  and  gives  an 
opaque  product  'aloe  hepatica.'  More  com- 
plete ana  rapid  evaporation  yields  glassy  'aloe 
mcida,'  whion  shows  no  crystals  under  the 
miofoscopeu  The  principal  varieties  found  in  the 
madet  are: — 

1.  Ovm^ao  {Batbadoe)  Aloes  (from  A.  eki- 
nenais.  Baker,  A.  vera,  L.),  fanneay  nroduced  in 
Barbados,  but  now  almost  excmsively  in 
Curasao  and  other  Butch  West  Lidian  islands. 
It  is  nsuaHv  opaque  ('  livery  *)  and  from  orange 
to  BiMiJy  black  in  colour. 

2.  dope  Aloes  (from  A.  ferox.  Miliar,  and 
other  South  African  species)  is  vitreous,  breaking 
readily  into  transparent  glassy,  reddish,  or  pale- 
brown  fragments.  It  is  the  diief  vaiie^  used 
in  Germany  and  adjoining  countries ;  in  Britain 
mostly  for  veterinary  purposes. 

3.  Socotrine  Aloes  (from  A,  Perryi,  Baker). 
It  is  generally  imported  in  a  moist  pasty  con- 
dition, and  is  of  a  dark  reddish-brown  colour. 
A  variety  of  Socotrine  Aloes  from  Zanzibar  often 
doeely  resembles  that  from  Curasao.  Of  these, 
Curafao  Aloes  Ib  the  only  one  containiQg 
appreciable  quantities  of  Mobarbaloin,  and  hence 
gives  Klunge's  reaction  characteristio  for  tins 
substance  {see  below)'.  With  concentrated  nitric 
acid  Curacao  aloes  become  at  once  deep  red; 
Socotrine  becomes  reddish-  or  yellowish-brown ; 
Cape  sloes  graduallv  green.  The  aqueous 
solution  (1  p.c)  of  all  varieties  shows  a  green 
fluorescence  on  adding  6  p.c.  borax  solution. 
Natal  aloes  is  no  longer  an  artide  of  commerce ; 
Uganda  aloes  (imported  from  Mossel  Bay)  is  a 
variety  of  Cape  aloes  produced  by  careful 
evaporation. 

AloiOB.    By  extracting  aloes  with  water  the 

guigative  principles,  alolns,  can  be  obtained, 
heostone  (PAann.  J.  [3]  13,  461 ;  Chem.  Soo. 
Trans.  44,  480)  divides  them  into  two  classes : 
1.  Naiakins,  which  only  yield  picric  snd  oxalic 
acids  with  nitric  acid,  and  which  are  not 
reddened  ^y  it,  even  on  heating  (Fliickiger, 
Arch.  Pharm.  [2]  149,  11 ;  Tilden,  Chem.  Soc. 
Trans.  26,  153).  2.  Bafbaioins,  which  yield 
aloetic  acid  Ci4H4(NOt)40g,  chrysammic  acid 
Ci^s(N0a)4(0H)30|,  picric  and  oxalic  adds, 
and  are  reddened  by  mtrio  add.  a-Barbaloins, 
from  Barbados  aloes  reddened  in  the  cold  by 
strong  nitrio  add  (Tilden,  Pharm.  J.  [3]  2,  846 ; 
Chem.  Soc.  Trans.  26, 488).  fi-BarhakHns,  from 
Socotrine,  Zanzibar,  and  Jafferabad  aloes, 
coloured  only  on  heating  with  ordinary,  and  in 
the  cold  with  fumiog,  nitrio  add  (Fliioldger,  Lc» ; 


Tilden,  Chem.  Soo.  Trans.  28,  1270;  Pharm. 
J.  [3]  4,  206). 

Al&in,  oificial  in  the  B.P.  and  U.S.P., 
and  obti^ned  chiefly  from  Cvoa^ao  aloes,  is  a 
yellow  crystalline  powder  consiBting  of  a  mixture 
of  barbaJinn  and  tscbatbaknn^  whi^  substances, 
according  to  JAfst  (Compt.  rend.  1911,  163, 
114),  are  iM>m«ne,  having  an  arabinoaa  group 
in  positions  1  and  8  rsnieotively.  I/ger  (J. 
Pharm.  Chim.  1907,  [vi]  26,  476,  618)  further 
considers  that  all  the  above-mentioned  varieties 
of  aloes  yield  barbaloln  with  the  exception  of 
the  Natal  variety,  which  gives  a  separate  sub- 
stance, nataloln.  The  amount  of  aloln  in 
Cura9ao  aloes  has  be«ai  variously  estimated  as 
from  10  to  30  p.a  In  addition,  there  is  present 
an  amorphous  aloln  (fi-basbaloin),  which  ii 
apparently  stereoisomeric  with  crystalline 
barbaloln,  and  ii  formed  from  the  latter  by 
heating  for  three  hours  to  160^-166^  and  partly 
by  aoetylation  (L^ger,  Compt.  rend.  1914,  168, 
1903).  Cape  aloes  contain  6-6  p.a  of  crystalline 
barbaloln  and  about  three  times  the  amount  of 
j3-barbaloln  (L^ger,  Compt.  rend.  1907,  146, 
1179). 

Tschirch  and  Pedersen  (Arch.  Phann.  236, 
200)  found  in  Barbados  aloes  12*26  p.c.  barbaloln, 
12*66  p.c.  resin,  1  *76  p.c.  ash,  10'6  p.o.  amon>hous 
constituents  soluble  in  water,  and  0*16  p.a 
aloe  emodin  (which  ii  afisdon  product  of  barba- 
loln, see  below ;  its  constitution  and  propertiBS 
are  given  under  Bhubabb).  The  resin  is  the 
cinnamate  of  aloeresinotannol  C|aH|404(0H)s(T). 
Acoordinff  to  Tutin  and  Naunton  (Pharm.  J. 
1914,  [iv.  J  37,  836)  the  proportion  of  aloe  emodin 
is  much  larger. 

Barbaloln  may  be  readily  prepared  by 
extracting  aloes  with  two  piurts  of  water  at 
90°-96'*;  the  crystab,  which  separate  on 
standing  for  some  days,  axe  recrystsllised  from 
water,  and  finally  from  alcohol.  It  forms 
small  yellow  prismatic  needles  containing  water 
of  crystallisation,  and  when  anhydrous,  mdting 
at  about  147*". 

Barbaloln  has  formed  the  subject  of  numerous 
investigations.  For  a  long  time  its  formula  was 
considered  to  be  ChHibO,  (Tilden,  Trans. 
1872,  26,  204;  1876,  28,  1270;  Schmidt, 
Ber.  1876,  8,  1276),  or  ClHuO;  (Groenewold, 
Arch.  Pharm.  1890,  228,  116;  L^ger,  Compt. 
rend.  1897,  126,  186).  Aschan  (Arch.  Pharm. 
1903,  241,  341)  and  Jowett  and  Potter  (Chem. 
Soc.  Trans.  1906,  87,  878)  confirmed  one  or 
other  of  these  formuls  by  molecular  weight 
determinations,  as  well  as  by  analysii.  Against 
thii  mass  of  evidence  we  must,  however,  place 
L4ger*s  observation  (Compt.  rend.  1902,  184, 
1111,  1584),  that  by  the  action  of  sodium 
peroxide  on  barbaloln,  there  are  formed  formic 
add,  aloe-emodin  CuHiqOi  (see  Bhttbabb), 
and  an  aldopentose  CiHioO^.  He  accordingly 
changed  the  formula  to  C,iUtoOt.  Later  he 
showed  (Compt.  rend.  1910,  150,  983,  1696; 
1912,  166,  172)  that  alcoholic  hydrogen  chloride 
also  produces  aloe-emodin  and  the  sugar,  which 
was  confirmed  by  Oesterle  and  Riat  (Schweiz. 
Woch.  Chem.  Pharm.  1909,  717).  FinaUy, 
L^ger  identified  the  sugar  with  certainty  as 
d-arabinoae ;  he  eonsiders  that  in  barbaloln  it 
is  attached  to  the  aloe-emodin  in  podUon  1,  and 
in  wobarbaloin  in  position  8  of  the  anthra- 
quinone;  the  sugar  is,  moreover,  attached  by 


164 


AL0B8. 


one    of   its   hydroxyl  sroups  and  not  by  the 
aldehyde  groap  as  in  other  glucosides. 

Seel  and  Kelber  (Ber.  1916,  49,  2364)  have 
confirmed  I^ger^s  formula  by  molecular  weight 
detenmnations  (c/.  also  Seel,  Kelber,  and  Scharf, 
Ber.  1917,  60,  769). 

The  only  way  of  reconciling  L^ger*s  results 
with  the  Oic  formula  would  be  to  regard  barba- 
loln  as  a  reduced  anthraquinone  derivative, 
which  breaks  down  by  two  simultaneous  but 
independent  reactions  to  aloe  emodin  and  d- 
arabmose ;  but  it  is  preferable  to  attribute  the 
earlier  adoialyticai  results  to  the  difficulty  of 
purifying  the  substance. 

BarlNUoin,  after  several  crystallisations  from 
alcohol,  does  not  show  a  sliarp  melting-point 
(146M6a^),  [a]o-10*4<' in  ethykceUte  (linger), 
— S'S"*  in  90  p.&  alcohol  (Jowett  and  Potter). 

Aloe-emodin  Ci»H,oOt,  m.p.  224^  is  an 
alcohol,  a  hydroxymethyl  dmydroxyanthra- 
qainone  (for  constitution  and  relationshipj,  see 
under  Bhubabb).  On  oxidation  with  chromic 
acid  barbaloin  gives  a  mixture  of  aloe-emodin 
and  the  corresponding  acid,  rhein  (Oesterle  and 
Babel,  Schweiz.  Woch.  Chem.  Pharm.  1904,  42, 
329),  which  mixture  was  named  by  TUden 
(Ghem.  Soo.  Trans.  1879,  32,  264,  903)  aloexan- 
thin. 

Isoibarhaloin  occurs,  according  to  Ceger,  in 
Barbados  aloes  to  the  extent  of  0'6  p.c. ;  it 
gives  the  same  hydrolytic  products  as  barbaloin, 
and  the  two  are  therefore  regarded  by  L6ger  as 
stereoisomerio  (Ck>mpt.  rend.  1910,  160,  1696). 
It  gives  Klunge's  reaction  {see  above),  and  is 
not  present  in  Socotrine  and  Cape  aloes. 

Nitric  acid  (D  1*2  at  lOO'')  oxidises  both 
barbalofn  and  iaobarbaloln  to  tetranitroaloe- 
emodin  Ci|HcO((NOt)4  (L^ger,  Compt.  rend. 
1910,  161,  1128;  1911,  163,  114),  which  by 
boiling  nitric  acid  (D  1*32)  is  converted  into 
chrysammic  acid  Ci4H,Os(OH),(N04),.  In  the 
mother-liquor  of  the  tetranitroaloe-emodin  Lcger 
found  2:4:  6-trinitro-3  hydroxybenzoio  acid, 
which  by  loss  of  carbon  dioxide  yields  picric 
acid«  In  addition  to  picric  and  chrysammic  acids 
the  older  observers  obtained  aloetic  acid  by 
the  action  of  nitric  acid  -on  aloin  ;  Oesterle  and 
Riat  (Schweiz.  Woch.  Chem.  Pharm.  1906,  44, 
609)  consider  aloetic  acid  to  be  trinitroaloe- 
emodin. 

Natal  aloes  contains  about  14  p.c.  of  nataUnn, 
m.p.  203^,  crystalliBed  from  boiling  ethyl  or 
methyl  alcohm.  Among  the  various  iormulse 
assisned  to  this  substance  probably  the  best 
established  is  that  of  I>ger  (J.  Pharm.  Chim. 
1903.  [vU.]  17, 13),  CpH,«Oio,  who  regards  it  as 
the  methyl  ether  of  homonaUUoin  C„H|,0«'OH, 
also  present  in  the  drug.  The  latter,  and 
probaoly  also  the  former,  of  these  alolns,  like 
oarbaloin,  yield  ci-arabinose  on  hydrolysis 
(Uger,  Compt.  rend.  1912,  166,  172),  which  is 
apparently  less  stably  attached  than  in  barba- 
loin to  a  ^'hydroxymethylanthraquinone, 
naialoemodint  orange-red  needles,  m.p.  220°,  and 
its  methyl  etiier. 

Nalawemodin  methylether,  pale  orange-yellow 
needles,  ULp.  238^,  is  formed  by  the  oxidation  of 
nataloin  with  sodium  peroxide  (Leger,  J.  Pharm. 
Chim.  1903,  [viL]  17,  13,  62).  Natalom  differs 
'rom  barbaloin  in  its  resistance  to  alkalis,  and 

not  yielding  chrysammic  add  or  aloexanthin 

oziaation  with  nitric  acid,  but  only  picric 


and  oxalic  acids  (Shenstone,  Chem.  Soc.  Trans. 
44,  480) ;  further,  in  not  giving  Klunge*s  and 
Bomtrasger's  reactions  (^ee  below).  Both  nata- 
loin and  its  lower  homologue  eive  a  green 
colouration  with  concentrated  sulphuric  acid  and 
manganese  dioxide  or  potassium  dichromate, 
and  a  violet  colouration  in  sodium  hydroxide 
solution  with  ammonium  persulphate  (I/ger). 
For  a  general  review  of  the  more  recent  work 
on  the  chemistry  of  the  alolns,  see  L^ger,  Ann. 
Chim.  1916,  [ix.]  6,  318-381. 

The  resin  from  Natal  aloes  yields  on  hydro- 
lysis p-coumario  acid  and  nataloresinotannol 
(3„Hi.04(OH),(t). 

StcaloHn  is  a  crystalline  substance  from  aloes 
of  Aloe  vulgaris,  native  in  Sidly.  Condb- 
Vissicchio  has  given  it  the  formula  CisHsoOt, 
and  finds  it  to  contain  one  methoxy  group ;  it 
does  not  fluoresoe  with  borax,  and  does  not 
give  Bomtraeger's  reaction  (below). 

The  alolns  from  Curasao,  Cape  Socotra, 
Uganda,  and  Jafferabad  a2oes  are  probably 
identical  with  barbaloin.  Zanaldin  from  Zanzi- 
bar aloes  appears  to  be  different  (L^ger,  J. 
Pharm.  26,  [vi.]  613  ;  Tschirch  and  Uoffbauer, 
Arch.  Pharm.  243,  399).  The  latter  chemists 
show  that  Barbados  aloes  contain  but  little 
woaloln,  Jafferabad  none,  whilst  that  itom 
Curacao  contains  a  considerable  proportion. 

Uses. — Chiefly  in  medicine  and  as  a  hop- 
substitute.  In  doses  of  0'l-0'3  gram  aloIn 
causes  puliation  in  8-20  hours,  given  by  the 
mouth  or  nypodermically.  In  the  latter  case, 
it  is  excreted  in  the  large  intestine,  where  it 
probably  is  first  oxidised  So  an  active  substance. 
The  oxidation  is  hastened  by  iron  salts,  whence 
the  use  of  Pilula  Aloes  et  Ferri.  Aloes  is  the 
basis  of  most  *  patent '  pills. 

Various  proposals  haye  been  made  for  con- 
verting aloIn  into  (insoluble  and)  tasteless  com- 
poun<£,  e.g.  by  condensation  with  formaldehyde 
m  dilute  sulpnuric  acid  solution  ('  formaloln  *  of 
£.  Merok),  with  carbonyl  chloride  or  ethyl 
chlorocarbonate  in  pyridine  solution  (Ger.  Pat. 
229191),  or  with  a  mixture' of  formic  and  aoetio 
acids  by  means  of  zinc  chloride  (Ger.  Pat. 
233326). 

Properties  artd  Reactions, — ^Pure  aloes  is 
soluble  in  ether  and  almost  completely  soluble 
in  water,  the  solution  being  coloured  dark- brown 
by  alkalis,  black  by  ferric  chloride,  and  grey  by 
lead  acetate  (Fluckiger).  By  adding  a  solution 
of  copper  sulphate  or  chloride  to  a  solution  of 
aloes,  an  intense  yellow-coloured  solution  is 
obtained,  which,  warmed  with  potassium 
bromide  or  chloride,  turns  to  a  deep-red  and 
reddish-violet  tint  (Klunge,  Ber.  16,  691 ;  Areh. 
Pharm.  1883,  363).  This  reaction  is  due  to  iso- 
barbaloin,  for  barbaloin,  recrystallised  several 
times  from  methyl  alcohol,  does  not  give  the 
test  (Ldger,  Compt.  rend.  131,  66).  Qomtraeger 
(Zeitsch.  anal.  (Jhem.  19,  166;  Ber.  13,  1040) 
extracts  with  twice  the  volume  of  benzene,  and 
adds  to  the  clear  extract  a  drop  of  ammonia, 
when,  on  warming  and  shaking,  the  solution 
becomes  violet-red ;  to  test  for  idoes  in  elixirs, 
liqueurs,  &c.,  the  alcohol  is  first  evaporated. 
This  is  a  general  reaction  for  hydroxymethyl 
anthraquinones.  Lenz  (Zeitsch.  anal.  Chem.  21, 
220)  extracts  with  amyl  alcohol,  evaporates 
the  extract,  treats  with  nitric  acid,  and  then 
with  potassium  cyanide  and  hydroxide,  when  a 


ALUDEL. 


165 


blood-red  coloiiraiion  is  obtained.  Grippe  and 
I>^ond  (Pharm.  J.  [3]  15,  633)  test  tor  aloin 
by  dissolving  1  grain  in  16  drops  of  strong  snl- 
phnric  acid,  then  adding  4  drops  of  nitric  acid 
(1*42)  and  1  ounce  of  water,  when  a  deep  orange 
or  crimson  colour  is  produced,  deepened  by 
ammonia;  substances  containing  cbiysophanio 
add  behave  in  a  similar  manner,  but  their 
aqueous  solution  turns  pink  npon  the  addition 
of  ammonia.  Aschan  (Aroh.  rhann.  241,  340) 
gives  in  tabular  form  a  comparison  ol  the 
reactions  of  the  chief  varieties  of  aloes.  The 
behaviour  towuds  nitric  acid  and  fluorescence 
with  borax  are  mentioned  above. 

Cuiavao  aloes  should  be  almost  entirely 
soluble  in  60  p.c.  alcohol,  and  contain  not  more 
than  3  p.c.  of  ash,  12  p.c.  of  moisture,  and 
30  p.c.  of  substances  insoluble  in  cold  water. 
Cape  aloes  should  dissolve  almost  completely 
in  12  parts  of  boiling  water,  and  completely  in 
6  parts  of  warm  90  p.o.  alcohol.  The  moisture 
should  not  exceed  5  p.c.,  the  ash  1*6  p.c.  At 
least  60  p-o.  is  soluble  m  cold  water.  According 
to  the  U.S.P.  the  aah  of  aloes  does  not  exceed 
4  p.0. 

A  process  for  the  estimation  of  aloin  in 
aloes  has  been  described  by  8ohaefer  (J.  Pharm. 
[vi.]  6«  296),  and  for  the  non-reainous  consti- 
tuents by  Tschiroh  and  Hoifbauer  .(Arch. 
Pharm.  1906,  243,  399).  The  latter  process  has 
been  modified  and  used  by  van  Itame  (Pharm. 
Weekblad,  1906, 42,  563)  for  the  evaluation  of 
aloes,  but  in  the  nature  of  things  these  processes 
are  not  very  accurate.  G.  B. 

ALOfiS,  ESSENTIAL On« OF.  A  nale^ellow 
mobile  liquid  to  which  the  odour  of  aloes  is  due. 
Sp.gr.  0-863,  boils  at  266''-27P.  It  exists  in 
smul  quantities  in  aloes,  and  when  pure  has  the 
taste  and  odour  of  peppermint  (Pharm.  J. 
[3]  10,  613). 

ALOES  WOOD.  A  name  applied  to  the  wood 
of  AquiOaria  AgaUocKa  (Roxb.),  a  leguminous 
tree  of  Cochin  China,  and  to  that  of  A,  mahc- 
eensis  (Lam.)  of  tropical  Asia.  BtfUi  are  highly 
fragrant  and  aromatic ;  used  in  fumigations 
and  pastilles,  and  occasionally  by  cabinet- 
makers and  inlayers. 

The  same  name  is  applied  to  the  resin.  Of 
all  pezfumes  this  is  said  to  be  the  most  esteemed 
by  Orientals. 

ALOIN  V.  Glucosides. 

ALOO  BOKHABA,  ALPOGADA,  PAZHAM. 
The  Bokhara  plum  (Prunua  insUUia  (Linn.)  [P. 
hokharieMia],  largely  imported  into  Bombay. 
Used  as  a  Illative.  The  root  is  astringent ;  the 
gum  is  used  as  a  substitute  for  gum  arable  under 
the  name  of  Persian  gum  (Bymock,  Pharm.  J. 
[31  9,  146). 

ALOUCHI  RESIN  v.  Ahichi  resin,  art.  Resin. 

ALPHOGEN  (Alphozone).  Trade  names  for 
■ucdnylperoxide. 

AUPHOL  V,  Synthstio  drugs. 

ALPINIA  OFnCDfARUM  v.  Galakoa  root. 

ALPINIA  OIL.  An  essential  oil  obtained 
from  the  leaves  of  Alpinia  malaecenaia ;  sp.gr. 
1«02  at  26"*,  rot.  power  +6'5°.  Consists  mainly 
of  methyl  cinnamate,  together  with  (2-pinene 
(Van  Rombuigh,  Proo.  K.  Acad.  Wetensch. 
Aoisterjlam,  1900,  3,  461). 

ALPININ  V.  Galaiyoa  root. 

ilLPOOADA  V.  Aloo  Bokhara. 

ALQUIVON.    Black  lead  ore  or  Potters*  ore. 


A  native  lead  sulphide,  used  by  potters  to  glaze 
coarse  ware. 

AL50L  V.  Synthbtio  drugs. 

ALSTONIA  BABK.  The  dried  bark  of 
Alsionia  schohris  (R.  Br)  and  A-  oonstncia 
(F.  Muell.),  an  apocynaceous  tree  growins  in 
Australia.  It  has  a  bitter  taste,  sligntly 
camphorous  odour,  contains  a  neutral  bitter 
principle(similartoeai/cecIr«f»and<«{«CMmtn), 
a  volatile  oil  smelling  like  camphor,  an  iron- 
greening  tannin,  resin,  fat,  wax,  a  protein-like 
substance,  oxalic  and  citric  adds  (Palm,  J. 
1863,  616). 

MGUer  and  Rummel  (Chem.  Soc.  Trans.  35, 
31)  obtained  a  yellow  substance  to  which  they 
gave  the  name  alskmine,  Oberlin  and  Schlag- 
denhauffen  (Pharm.  J.  [3]  10,  1059;  Chem. 
Soc.  Abstr.  38,  127)  showed  that  this  body 
consisted  of  two  compounds,  alstonine  and 
alatonicine,  the  former  bein^  soluble  in  acids 
with  fluorescence,  the  latter  without. 

Hesse  subsequently  (Ber.  14,  264 ;  Annalen, 
206,  360)  isolated : 

Alaionine  (chlorogenine)  CBoHtiN,0^,  a  brown 
amorphous  mass,  a  strong  base,  soluble  m  chloro- 
form, alcohol,  and  apanngly  soluble  in  ether, 
and  melting  when  anhydrous  at  196^  (unoorr.). 

Porphyrine  C,iH,,N,Os,  a  white  powder 
melting  at  97°  (uncprr.),  soluble  in  alcohol,  chlo- 
roform, ether,  and  acids,  with  blue  fluorescence. 

Porphyroeine,  soluble  in  acetic  acid,  forming 
a  pink  solution. 

AUUmidine,  colourless  needles,  melting  at 
181®  (unoorr.),  soluble  in  chloroform,  ether, 
alcohol,  and  acetone. 

Hesse,  however,  could  not  find  a  trace  of 
quinine  (Ber.  11,  1546,  1763). 

ALSTONIA  SPECTABIUS.  PoeUhark.  Con- 
tains dUUmamina  (Hesse,  Ber.  11,  1548),  and 
the  alkaloids  of  dita  bark.  It  contains  six 
times  as  much  echitammonium  hydroxide  as 
diU  bark  (Hesse,  Annalen,  203,  144). 

Its  physiological  action  is  like  that  of  curare. 

ALSTONINE.  One  of  a  series  of  ill-defined 
alkaloids  occurring  in  AUUmia  spp.  (Hesse, 
Annalen,  1880,  203,  147 ;  206,  360),  including 
aUtonamine,  cUsUmidine,  ditaine,  ditamine,  &c. 

ALSTONITE.  A  rare  minml  consisting  of 
barium  and  calcium  carbonate  (Ba,Ca)COs» 
crystallising  in  the  orthorhombio  system.  The 
small  crystals  have  the  form  of  acute  six-sided 
pyramids,  and  consist  of  complex  twin  inter- 
growths.  Found,  associated  with  witherite,  in 
1834  in  a  lead-  and  zinc-mine  near  Alston  in 
Cumberland,  and  at  Fallowfield  in  Northumber- 
land ;  and  in  1909  in  a  coal-mine  near  Durham. 
This  species  is  often,  but  incorrectly,  called 
bromlite  {cf.  Barytocalgitx).  L.  J.  S. 

ALTHEIN.  See  Anthocyanins.  The  term 
AUhein  is  used  also  as  syn.  for  Asparagin. 

ALTI.  Indian  name  for  a  root  used  at  Goa 
as  a  substitute  for  Althaea  (Dymock,  Pharm.  J. 
[3]  8,  101). 

ALUDEL.  The  aludels  of  the  parlier  chemists 
were  pear-shaped  pots  senerally  made  of  earthen- 
ware, but  sometimes  of  glass,  open  at  both  ends. 
Each  aludel  had  a  short  neck  at  the  top  and 
bottom,  so  that  a  series  of  them  could  be  fitted 
together  by  means  of  the  necks.  The  earthen- 
ware pear-shaped  vessels  in  which  the  mercurial 
vapours  are  condensed  at  Almaden  in  Spain  are 
also  known  as  aludels. 


156 


ALUM. 


ALUM  V.  Aluminium. 

ALUMINATES  v.  Aluminium. 

ALUMINIUM.    Sym.  AL    At.  wt.  27'L 

Occurrence. — ^Aluminium  is  the  most  widely 
distributed  element  in  nature  with  the  exception 
of  oxygen  and  silicon.  It  is  not  found  in  the 
metaUic  state. 

As  oxide,  A1,0,»  aluminium  ia  found  in  co- 
rundwiif  or,  coloured  by  metallic  oxides,  in 
MpphirCf  ruby,  emery,  &o.  The  hydrated 
onde  AlsO„HaO  occurs  as  ditupore,  and,  to- 
aether  with  fenic  oxide,  silica,  &c.,  as  the 
important  mineral  bauxite. 

Alnmminm  occuTs  in  Combination  with 
oxygen  and  metals  as  aluminates,  in  spinel 
AlaOt'MgO,  chryecberyl  AlaO,'BeO,  gahniU 
AltO.'ZnO.  As  hydrated  sulphate  it  is  found  in 
aiumtnite  or  websteriU  Al|Oj30„9H,0,  and  as 
(Uunogen  Al,0s(S0t)„18M,0 ;  as  the  double 
sulphate  of  aluminium,  potassium,  and  sodium 
in  dhinuione  or  aluniie ;  and,  as  an  efflorescence 
on  aluminous  minerals  in  the  form  of  the  alums 
of  potassium,  sodium,  ammonium,  &c. 

Aluminium  occurs  principally,  however,  as 
silicate  m  the  various  ctays ;  as  silicate  contain- 
ing silicon  fluoride  in  the  topeu ;  and,  as  double 
silicate,  with  iron,  magnesia,  lime,  &c.,  in 
garnets;  with  potassium,  sodium,  magnesium, 
and  ciJcium  in  immense  .quantities  in  the 
varieties  of  felspar. 

Am  double  fluoride  of  aluminium  and  sodium 
it  is  found  in  cryoliU  Al,F,*6NaF ;  as  hydrated 
phosphate  in  the  turquoise  and  in  waveUite,  and 
as  borate  in  a  crystalline  mineral  occurring  in 
Siberia. 

Althou^  present  in  such  quantities  in  the 
soil,  aluminium  is  not  usually  considered  a 
constituent  of  the  ash  of  plants  except  of  cryp- 
togams; Yoshida,  however  (Ghem.  Soa  Trans. 
18o7,  748),  has  found  it  in  a  number  of  phanero- 
gams in  Japan. 

History. — ^The  name  of  this  metal  is  derived 
from  alumen,  a  term  applied  by  the  Romans  to 
all  bodies  of  an  astringent  taste.  Pott,  in  174G, 
stated  that  the  basis  of  alum  is  an  aiffillaceouii 
earth ;  and  in  1754  Mar^^gnf  pointed  out  the 
distinction  between  alumina  and  lime,  and  its 
presence  in  combination  with  silica  in  day. 

Davy,  in  1807,  havit^  isolated  the  alkali 
metals  by  dectricity,  endeavoured,  unsucoess- 
fidly,  to  reduce  alumina  in  the  same  manner. 

Oersted,  in  1824,  prepared  aluminium  chloride 
by  passing  chlorine  over  a  mixture  of  alumina 
and  carbon  heated  to  redness.  He  appears  to 
have  reduced  the  chloride  to  the  metaUio  condi- 
tion by  heating  with  potassium  amalsam : 
(Berzehus,  Jahresb.  1827,[6]  118).  The  amidgam 
produced  oxidised  rapidly  in  the  air,  and  left,  on 
volatilising  the  potassium,  a  tin- white  metaL 

Wohler,  in  1827  (Annalen,  1828,  37,  66), 
having  failed  to  procure  the  metal  by  Oented*B 
meth^,  obtained  it  by  the  decomposition  of  the 
anhydrous  chloride  with  potassium,  as  a  grey 
poinler,  which  became  brilliant  under  the 
burnisher. 

Bunsen  and  Deville,  in  1854,  independently, 
obtained  the  metal  by  electrolysis  of  the  fused 
chloride.  PeviUe,  in  the  same  year,  much  sim- 
idified  the  manufacture  by  substitutinff  sodium 
for  the  more  expensiye  potassium,  in  1854 
he  was  installed  m  the  manufactory  of  Javel 
by  the  Emperor  Napoleon  III.,  and  supplied 


with  the  necessary  apparatus  for  experimente 
on  the  large  scale.  Arterwards  his  process  was 
removed  to  Nanterre  and  finally  to  S^indres. 
A  description  of  his  method  is  given  in  Ann. 
C!hem.  Phva.  [3]  43,  5-36,  and  specimens  of  the 
metal  produced  were  shown  at  the  Paris  Exhibi- 
tion of  1855. 

Shortly  after  the  publication  of  these  results, 
Messrs.  Dick  and  Smith,  under  the  direction  of 
Dr.  Percy,  prepared  aluminium  by  the  action  of 
sodium  on  the  then  newly  discovered  mineral 
cryolite,  some  of  the  product  being  shown  by 
Faraday  at  the  Royal  Institution  inMarch,  1855 
(PhiL  Mag.  10,  365). 

About  six  months  subsequently.  Rose,  inde- 
pendently, prepared  it  in  the  same  maimer,  and 
fublished  ms  results  in  an  extended  article  in 
\  96,  152  (PhiL  Mag.  10,  233). 

Deville  at  once  turned  his  attention  to  this 
process  (Ann.  Ghim.  Phys.  [3]  46,  451) ;  but  on 
account  of  the  impurity  of  the  metal  nroduoed, 
he  preferred  the  double  chloride  of  aluminium 
and  sodium,  using  cryoUto  as  a  flux  only. 

The  first  manufactory  in  England  was  started 
at  Battorsea,  London,  in  1859,  by  F.  W.  Gerhard. 
Some  of  his  metal  was  shown  at  the  Society  of 
Arts  Exhibition  in  1860.  Messrs.  Bell,  of  New- 
castle, also  prepared  aluminium  and  aluminium 
bronze  in  1863,  using  Netto's  process.  A  mixture 
of  200  lbs.  of  cryoSto  and  an  equal  weight  of 
common  salt  was  brought  to  fusion,  and  So  lbs. 
of  sodium  gradually  added.  The  charge  thus 
contained  only  5  p.c.  of  aluminium,  but  less  than 
half  of  this  was  oDtained  in  the  yield. 

The  manufacture  ceased  in  1874.  In 
Grabau's  process  (J.  Soc.  Ghem.  Ind.  1891, 
433)  aluminium  fluoride  was  subjected  to  the 
action  of  metallic  sodium.  Other  modifica- 
tions were  proposed  from  time  to  time,  but 
the  production  of  aluminium  made  no  notable 
advance.  Weldon,  in  1883,  summed  up  the 
position  of  the  industry  in  the  statement  that 
the  onl^  method  known  for  the  manufacture 
of  aluminiunf  is  Deville's.  M.  Pechiney  has 
improved  and  cheapened  the  modes  of  working, 
and  the  appliances  for  carrying  that  method  into 
effect,  but  this  is  all  the  progress  which  has  been 
made  in  the  manufacture  of  aluminium  during 
the  last  five  and  twenty  years.' 

When  the  great  stability  of  the  available 
compounds  containinff  aluminium  is  considered, 
it  is  not  to  be  wondered  at  that  the  many  attempts 
that  have  been  made  to  prepare  the  metal  by  the 
action  of  the  usual  reducing  agente,  such  as 
carbon,  hydrogen,  or  hydxtniarbons,  have  met 
with  so  little  success.    The  heat  of  formation 
of  these  compounds  is  an  index  to  their  stability, 
and  may  be  taken  as  a  measure  of  the  energy 
requisite  for  the  isolation  of  the  lUuminium. 
The  operation  is  not  likely  to  succeed  unless 
the  elements  which  become  separated  from  the 
aluminium  enter  into  new  combinations  of  still 
greater  stability.    The  nature  of  the  changes 
that  might  be  expected  to  take  place  may  be 
expressed  in  the  following  equations : — 
2A1,0, +  3C       «    4A1  +  3CO, 
or      A1,0, -I-3C       =    2Al-f3CO 
A1,0, -{-6H      »    2A1  +  3H,0 
A1,0, +  6Na     »    2Al  +  3Na,0 
Al,a, +  6H       a    2Al-f6Ha 
Al.a, +  6Na     =     2Al-f6Naa 
A1,F, -f6Na     <-    2Al  +  6NaF. 


ALUVJNTUM. 


117 


In  Older  that  then  mi^  be  a  likelihood  of 
these  leaotions  ooonrring,  the  heat  arinng  from 
the  formation  of  the  oomponnda  on  the  right 
hand  should  exceed  the  heat  concerned  m  the 
decomposition  of  the  aluminium  compounds  on 
the  left,  ^e  following  table  will  show  how  far 
this  is  the  case : — 


Calories 

Voramoiimt 

equlTalnt 

to2Al 

A1,0, 

AljCl, 
A1,P, 

391,600 

323,600 
558,000 

1^' 

3H,0 

3Na.O 

6Hd 

6Naa 

6NaF 

145,500 
86,400 
174,900 
302,700 
132,000 
587,400 
604,200 

It  will  be  seen  that  only  the  last  two  reactions 
will  be  at  aU  likely  to  take  place,  and  these  heat 
values  indicate  that  sodium  is  a  much  more 
favourable  reagent  than  carbon  or  hydrogen, 
and  that  the  highest  excess  of  heat  evolved  over 
that  absorbed  occurs  in  the  case  of  the  aluminium 
chloride  in  presence  of  sodium. 

The  following  analyses,  taken  from  Hoff- 
mann's Ber.  Entwick.  GheuL  Ind.  (1)  603,  show 
the  composition  of  commercial  aluminium  as 
produced  under  Deville's  process : — 


MoisBan  has  shown  (Compt.  rend.  121,  861) 
that  it  contained  alro  from  0*1  to  0*5  p.a  of 
sodium;  0*3  to  0*4  p.c.  of  carbon  and^ other 
impurities.  These  impurities  would  have  a  Ytrv 
considerable  effect  on  the  properties  of  the  metal, 
and  statements  baaed  on  observations  with 
such  metal,  or  even  metal  now  beinff  made, 
must  be  accepted  with  due  regard  to  these 
impurities. 

The  production  even  in  1885  was  small  and 
did  not  exceed  2}  tons  at  Salindies  and  2i  owt. 
in  the  United  States. 

According  to  Mallet,  pure  aluminium  may 
be  prepared  by  the  metnod  adopted  by  him 
in  lus  determination  of  the  atomic  weight  of 
chat  element  (PhiL  Trans.  171, 1018).  Oidinary 
oommercial  aluminium  is  converted  into  bromide 
by  the  direct  action  of  bromine.  On  account 
of  the  violence  of  the  action,  the  metal  should 
be  immersed  only  for  a  short  time,  at  intervals, 
until  dissolved,  or  should  be  added  in  very 
small  pieces.  The  bromide  so  produced  is  freed 
from  oromine  by  distillation  and  fractionally 
distilled,  that  portion  boiling  uniformly  at 
263-3*  being  reserved.  This  portion  is  colour- 
less, entirely  soluble  in  water,  and  consists  of 
the  pure  bromide. 

it  is  heated  with  sodium  (which  has  been 
carefully  freed  from  oil  and  weU  scraped)  in  a 
crucible  made  of  a  mixture  of  pure  alumina  and 
sodium    aluminato.    The    amount   of    sodium 


1 

2 

t 

4 

ft 

6 

7 

8 

0 

10 

Locality 

Paris 

Paris 

Berlin 

Paris 

Paris 

Paris 

Bom 

Kanteire  (Morin) 

Analyst 

Salvfitat 

8alv«tat 

Uallet 

— 

Dumas 

Dumas 

Krant 

Kraat 

Kiant 

Saoflrwein 

Alnminium 
Silicon  . 
Iron 

SST:    : 

Sodium. 

88-35 
2-87 
2-40 
6-38 

trace 

92-97 
215 
4-88 

trace 

96*25 
0-45 
3-29 

traoe 

92-60 
0*46 
7*55 

92-5 
0-7 
6-8 

96-16 
0-47 
3-37 

94-7 
3-7 
1-6 

0-04 
1-62 

0*12 
2*26 

97-2 
0-25 
2-40 

trace 

used  shooed  not  be  sufficient  to  rrduce  the 
whole  of  the  bromide,  or  the  aluminium  is 
liable  to  contain  sodium.  The  globules  of 
metal  are  fused  together  before  the  blowpipe 
on  a  bed  of  alumina,  immersed  for  a  short  time 
in  hydrochlorio  add,  washed  and  dried.  Pure 
aluminium  might  also  be  produced  by  the  elec- 
trohnils  of  the  pure  bromide  or  chloride. 

The  purification  from  metallic  impurities  on 
the  luge  scale  involves  many  difficulties.  The 
only  method  of  obtaining  satisfactory  metal  is 
to  ensure  as  high  a  state  of  purity  as  possible 
in  the  first  instance  by  making  use  of  selected 
materials  and  avoidii^  contamination  in  the 
process  of  manufacture. 

By  the  establishment  of  Deville's  process 
the  price  of  aluminium  had  been  brought  down 
from  182.  per  lb.  to  II.,  at  which  it  stood  till 
1887. 

The  double  chloride  of  sodium  and  aluminium 
need  contained  only  14  p.c.  of  aluminium,  and 
the  working  of  lane  chaiges  with  a  small  yield 
together  with  the  nigh  cost  of  sodium  and  fuel 
stood  in  the  way  of  any  prospect  of  reduction 
in  the  price  of  the  metaL 

The  introduction  of  Castner's  process,  by 
which  sodium  could  be  produced  much  more 


cheaply,  led  to  the  establishment  of  the  Alu- 
minium Company's  works  at  Oldbury,  and 
effected  some  reduction  in  the  price  of  alu- 
minium. Meanwhile  Messrs.  Oowles  (Patents 
Aug.  18,  1885,  and  Jan.  26,  1886)  brought 
electrical  heating  into  operation,  and,  though 
their  prooess  was  not  adapted  to  the  production 
of  aluminium,  it  was  capaole  of  fumisning  allovs 
of  aluminium  with  copper  and  other  metals. 
These  could  be  made  at  one-tonth  the  price 
which  had  ruled  for  aluminium,  and  the  valuable 
properties  of  aluminium  bronze,  Hercules  metal, 
ana  other  alloys  were  soon  recognised.  More- 
over, the  discovery  of  the  effect  of  the  addition 
of  minuto  amounts  of  aluminium  to  iron  and 
steel  gave  a  further  stimulus  to  the  production 
of  aluminium.  G.  W.  Siemens  had  already 
described  an  electric  furnace  (1881)  capable  of 
dving  very  high  temperatures,  and  the  type  of 
furnace  patented  by  Messrs  Gowles  Bros,  was 
based  on  similar  lines. 

The  furnace  is  a  rectangular  box,  one  foot 
wide,  five  feet  long,  and  fifteen  inches  deep,  all 
inside  measures.  Two  carbon  electrodes  pass 
through  pipes  in  the  ends ;  they  are  three  inches 
in  diameter  and  thirty  inches  long ;  this  size 
could  not  be  exceeded,  as  larger  carbons  dis- 


15S 


ALUMINIUM. 


inteffrated  under'  the  intenae  heat.  For  a  non- 
oonauoting  fornaoe  lining,  fine  particles  of 
charcoal  are  washed  in  lime-water,  exposed  to 
the  air  and  dried.  They  thus  hecome  coated 
with  lime  and  are  of  good  insulating  power. 
At  the  high  temperature  produced,  oidinaiy 
charcoal  becomes  conyerted  into  graphite  and 
forms  a  ffood  conductor.  The  two  electrodes 
being  within  a  few  inches  of  one  another,  the 
charge  of  twenty-five  parts  of  corundum,  twelve 
parts  of  carbon,  and  fifty  parts  of  granulated 
copper  is  placed  around  and  between  them, 
covered  with  small  lumps  of  charcoal,  and  the 
whole  covered  with  an  iron  top  lined  with  fire- 
brick. The  current  from  a  powerful  dynamo  is 
then  passed,  and  the  electrodes  moved  if 
necessary  to  produce  the  requisite  resistance. 
In  about  ten  minutes,  the  copper  bavins  melted 
between  the  electrodes,  the  distance  oetween 
them  is  increased  while  the  current  is  raised  to 
300  amperes  of  fiftv  volts  E.M.F.  and  the 
yield  1  lb.  per  B.P.H.  hour.  As  the  resistance  is 
increased,  the  temperature  rises,  the  alumina 
is  reduced  to  the  metallic  condition  and 
alloys  with  the  copper,  while  its  oxygen  forms 
carbon  monoxide  and  bums  at  the  openings 
in  the  cover  with  a  white  fiame.  After 
about  five  hours  the  operation  is  completed. 
The  alloy  produced  is  brittle,  consisting  of 
copper  and  15  p.c  or  upwards  of  aluminium. 
When  boron  or  silicon  oxides  have  been  added, 
the  bronzes  produced  contain  these  elements. 
It  is  melted,  cast  into  ingots,  the  percentage  of 
aluminium  determined,  and  sufficient  copper 
added  to  produce  '  aluminium  bron7e,*  or  the 
required  alloy. 

When  other  metals,  such  as  iron,  nickel^ 
silver,  fta,  are  substituted  for  copper,  corre- 
sponding sJloys  are  produced. 

The  slag  produced  is  hard  and  compact,  but 
soon  falls  to  a  fine  alkaline  powder ;  it  contains 
alumina^  calcium  .aluminate,  with  traces  of 
copper,  silicon,  &c 

Pure  aluminium  cannot  be  produced  satis- 
factorily by  this  method,  as  it  remains,  to  a  great 
extent,  mingled  with  the  carbon. 

See  further,  W.  P.  Thompson  (J.  Soc.  Chem. 
Ind.  1886,  206);  Mabery  (Amer.  J.  Sci.  308. 
and  Amer.  Chem.  J.  1887,  11). 

The  Electrical  Process. — ^A  new  principle  was, 
however,  introduced  into  metallurgy,  and  the 
application  of  electricity  for  purposes  of  heating 
and  reduction  of  metals  has  made  rapid  pro- 
ffress  in  recent  years.  Its  full  development 
had  not,  however,  been  reached  in  the  pro- 
oess  just  described.  It  had  been  shown  that, 
thouffh  the  fusion  of  a  substance  like  alumina 
could  not  be  economically  effected  owing  to  its 
high  resistance,  the  addition  of  copper  and  other 
metals  enabled  the  furnace  charge  to  conduct 
the  current.  If  a  suitable  solvent  could  be 
found  for  alumina  then  the  electrolytic  action 
of  the  current  could  be  brought  into  play. 
When  this  was  accomplished  the  chemical 
method  of  decomposition  would  give  place  to 
the  electrolytic  method,  and  the  isolation  of 
aluminium  become  a  question  of  a  sufficient 
current  at  the  necessary  voltaffe.  This  voltage 
can  readily  be  calculated  from  the  heat  of  forma- 
tion of  the  compound  in  question  by  dividing 
the  number  of  calorics  per  equivalent  by  23,250. 
We  thus  obtain   for   alumina   2*81    volts,   for 


aluminium  chloride  2*32  Tolts,  for  aluminiun 
fluoride  4*00  volts,  for  aluminium  sulphide  0*9 
volt. 

A  suitable  solvent  is  found  in  native  cirolite 
SNaF'AlFf,  which  may  be  brought  to  nisioD 
below  1000"",  and  will  dissolve  16  to  20  p.c.  of 
its  weight  of  alumina,  and  in  this  condition, 
also  owing  to  high  temperature,  the  voltage  is 
lower — ^in  the  case  of  alumina  about  2*3  volts. 

In  the  year  1886  the  He'roult  process  was 
patented  and  soon  came  into  use  at  l^euhausen, 
and  at  the  Soci^t^  Electrom^talluigique  at 
Froges,  near  Grenoble.  In  this  process  the 
anodes  consisted  of  carbon  and  the  cathode 
was  the  carbon  lining  of  the  furnace,  the  distance 
between  the  anode  and  cathode  beinff  capable 
of  adjustment  by  raising  or  lowering  the  anode. 
The  cryolite  was  first  melted  in  we  batli  1^ 
utilising  the  heat  generated  by  the  resistanoe 
to  the  electric  current,  and  then  alumina  was 
added,  and  the  additions  continued  from  time 
to  time  as  the  bath  became  exhausted.  The 
metallic  aluminium  settled  at  the  bottom  of  the 
bath  in  the  neighbourhood  of  the  cathode,  and 
was  tapped  every  24  hours. 

The  purity  of  the  metal  at  first  was  97-09 
p.c.  There  were  at  disposal  360  kilowa^  at 
Froges,  and  just  over  1000  kilowatts  at  Neu- 
hausen  (J.  Soc.  CHiem.  Ind.  1892,  910);  the 
yield  usually  obtained  was  about  1^  lbs.  of 
aluminium  per  kilowatt-day,  an  efficiency  of  less 
than  26  p.c.  To-day  &  p.o.  efficiency  is 
reached. 

The  HaU  process,  brought  out  in  the  United 
States  about  the  same  time,  only  differed  from 
H^roult's  in  matters  of  detidl,  the  anodes  being 
rods  of  carbon  3  inches  in  diameter,  or  of  larger 
dimensions  in  sections  banded  together,  the 
electrolyte  being  alumina  diaBolvea  in  mixed 
fiuoiides  of  calcium  and  aluminium  or  AlF^'NaF. 

Minet  (Gompt  rend.  112,  231)  used  a  bath 
composed  of  62-6  p.c.  of  common  salt  and  37*6 
p.c.  of  cryolite,  but  his  metal  seems  to  have 
contained  2  to  3  p.c.  of  impurity,  which  was 
chiefiv  silicon,  owing  largely  to  the  impurity  of 
the  alumina  used  by  him.  Aluminium  so  pre- 
pared was  liable  to  contain  sodium,  owing  to 
the  fact  that  the  voltage  necessary  for  the 
decomposition  of  aluminium  fluoride  differed  so 
little  from  that  required  to  decompose  sodium 
fluoride — ^viz.  4*7  as  against  4. 

There  was  added  to  the  bath  as  the  operation 
proceeded,  a  mixture  of  hydrated  alumina,  cry- 
oUto,  and  alumina  dissolved  in  cryolite. 

Kleiner  invented  a  furnace  for  we  decomposi- 
tion of  cryolite,  and  carried  on  the  production 
of  aluminium  at  Tyldesley  in  Lancashire;  a 
plant  was  also  operated  on  the  lines  of  the 
H^oult  systom  at  Patricroft  near  Manchester. 

In  this  case  the  dynamos  were  run  by  steam 
power,  and  it  soon  became  manifest  that  this 
could  not  compete  with  advantageous  sup^es 
of  water  power  which  began  to  be  called  into 
requisition  wherever  such  power  was  available. 

Mention  should  also  be  made  of  the  method  of 
Bucherer,  D.  R.  P.  63996  (1892),  who  prepared 
aluminium  by  electrolysing  the  double  sulphide 
of  aluminium  and  an  alkali  or  alkaline  earth, 
the  chief  obstacle  to  success  being  the  expense 
ond  difficulty  attending  the  production  of  the 
sulphide. 

It  Boon  became  evident  that  the  Hall  and 


ALUICINIUM. 


169 


H^roolt  process  must  hold  the  field,  and  that  | 
eoal  oonla  not  oompeto  with  cheap  water  power 
in  this  industry,  and  r^pid  expansions  of  the 
indnstry  were  made.  The  price  had  by  1891 
been  brought  down  to  one-fifth  of  that  which 
had  ruled  under  Deville's  process,  and  the 
production  had  increased  to  over  300  tons  per 
annum.  The  accompanying  statement  is  the 
cost  of  production  at  this  period,  as  given  bv 
A.  R  Hunt  (Eng.  and  Mining  Joum.  1891,  280). 
For  1  lb.  of  aluminium  there  was  requisite 
2  lbs.  alumina  costing  0  cents 


tt 


ft 


»> 


•» 


2 
1 
6 
6 


»» 


ff 


»• 


1  lb.  carbon  electrode 
CS&emicals,  pots,  &c. 
22  E.H.P  one  hour 
Labour,  interest,  repairs 
making  19  cents  in  all. 

The  following   firms   were  at  this   period 
manufacturing  either  aluminium  or  its  alloys : — 
In  England — 
Cowries  Syndicate  (Cowles  process). 
Reduction  Syndicate  (Hall  process). 
In  the  United  Statee— 

Pittsbun;  Reduction  Company. 
Oowles  ]3ectric  Smelting  Oompany. 
United  States  Aluminium  Metal  Go. 
On  the  Continent^ 
Sod^bft  Electrom^tallursique  at  IVocea. 
Aluminium  Industrie   Actien-Qeseuschaft 
at  Neuhausen. 
Further  progress  was  mainly  in  the  direction 
of  increasing  the  yield  and  bringing  down  the 
cost  of  production  whilst  perfecting  the  various 
details  of  the  process  so  that  a  purer  product 
could  be  made. 

Weshall  now  describe  the  further  development 
of  the  industry  and  the  manufacture  as  it  stands 
to-day  after  over  20  years  of  experience ;  and  in 
doinfl  so  it  will  be  weU  to  consider  in  mater 
detau  (a)  the  production  of  alumina,  (o)  the 
tni^lring  of  the  carbon  electrodes,  (c)  the  nature 
and  arrangement  of  plant,  induding  the  reduc- 
tion furnaces. 

Development  of  ike  Aluminium  Industry.— 
The  first  lactory  established  on  electrical  lines 
was  that  started  in  1888,  at  New  Kensington, 
by  the  Pittsburg  Ck>mpany,  which  is  now  known 
as  the  Aluminium  Company  of  America,  and 
conducts  operations  at  the  Niagara  Falls,  the 
Shawinigan  Falls,  and  at  Massena. 

Amongst  the  pioneers  of  the  indnstir  were 
also  ( 1 )  Aluminium  Industrie  Aktien-Gesellschaf  t, 
who  control  works  at  Neuhausen,  Rheinfelden, 
and  Lend  Gastein ;  (2)  the  British  Aluminium 
Company,  with  reduction  works  operating  in 
1896  at  Foyers  and  now  at  Kinlochleven  (Aigyll- 
shire),  and  branch  works  at  Lame,  Burntisland, 
Wanrhigton  and  Milton  (Staffordshire), — ^this 
company  is  also  associated  with  reduction  works 
at  Stanford  and  Vigelands  Brug  (Norway), 
and  projected  works  at  Orsi^res  (Switzerland) ; 
(3)  Soci6t^  Electrom^talluigique  Fran^aise  at 
Froges,  La  Praz,  and  St.  Biichael,  and  the 
Cie.  des  Produits  Ghimiques  d'Alais  et  de  la 
Carmaigue. 

There  were  formerly  works  on  a  smaller 
scale  under  the  Aluminium  Corporation  at 
Wallsend,  now  in  operation  at  Dolgarrpff  (N. 
Wales),  and  developments  in  Italy  at  Sussi. 
The  cost  of  production  of  the  metal  to-day  is 
said  to  be  61  £  per  ton  as  a  minimum,  though  at 
most  works  it  would  reach  802.  (Mining  World, 


June  26,  1909).  For  the  past  five  3rean  costs 
have  been  much  higher. 

The  market  price  of  aluminium  ingots  in 
1902-4  was  1202.  per  ton,  but  it  rose  to  2002.  in 
1906,  and  has  since  then  fallen  to  662.  (1909), 
though  it  is  now  again  advancing.  Since  1902 
no  trustworthy  record  has  been  made  of  the 
world's  output  of  aluminium.  It  remained, 
however,  fairly  stationary  in  the  neighbourhood 
of  8000  tons  from  1900  to  1905  indusive,  and 
since  then  has  grown  steadily,  and  may  be 
estimated  for  1909  at  30,000  tons.  In  the 
United  States  Geological  Survey  publications 
(Metallic  Products)  for  1908  there  may  be  found 
the  estimated  consumption  of  metal  in  the  United 
States,  from  which  it  appears  that  in  1907  this 
amounted  to  nearly  7700  tons,  and  in  1908  to 
neariv  5000  tons. 

Tne  following  is  a  statement  of  the  produc- 
tion  of  aluminium  in  metric  tons  from  1889  to 
1913,  (a)  in  the  United  States  and  Canada,  {b) 
total  output : — 


a 

h 

1889  . 

22  . 

93 

1890  . 

28  . 

193 

1891  . 

68  . 

302 

1892  . 

118  . 

606 

1893  . 

154  . 

870 

1894  . 

260  . 

1491 

1895  . 

417  . 

1836 

1896  . 

691  . 

2260 

1897  . 

1814  . 

6220 

1898  . 

.   2359  . 

.   6860 

1899  . 

.   2948  . 

.   8950 

1910  . 

.  17400  . 

.  43800 

1911  • 

.  20600  . 

.  45000 

1912  . 

.  29200  . 

.  63000 

1913  . 

.  32300  . 

.  68000 

During  the  period  of  the  war,  1914  to  1918, 
the  data  available  are  incomplete  and  hardly  to 
be  depended  upon.  Considerably  increased 
outputs  are,  however,  recorded.  In  1917  there 
appear  to  have  been  about  79,500  tons  manu- 
factured in  the  United  States  and  Canada  with 
168,000  tons  «s  total  output.  France  in  that 
^ear  produced  about  20,500  tons ;  Gomany,  who 
in  1913  produced  only  800  tons,  put  down 
during  the  war  large  instalments  of  plant 
sufficing  for  40,000  tons ;  the  British  production 
was  13,000  tons  and  that  of  the  other  European 
countries  15,000  tons.  Switzerland  is  stated  to 
have  exported  nearly  10,000  tons  per  annum 
into  Germany.  Norway  made  large  extensions 
in  reduction  works  which  did  not  become 
effective  owing  to  lack  of  raw  materials.  In 
other  directions  her  efforts  in  electrochemical 
developments  have  been  such  as  to  command 
125,000  kilowatts  in  1917  as  compared  with 
9000  kilowatts  in  1904. 

The  Production  of  Alumina, — ^The  raw 
material  from  which  the  alumina  is  usui^y 
made  is  bauxite,  deposits  of  which  occur  at 
Beaux  and  in  the  Var  (8.  France),  at  Feistritz 
(Austria),  Wochein  (Styria),  Irish  Hill  (Ireland), 
Georgia,  Arkansas,  Alabama,  Tennessee  (United 
States),  British  Guiana,  and  in  New  South 
Wales.  The  physical  condition  of  the  bauxite 
varies  considerably,  so  that  some  kinds  are 
more  readily  acted  upon  for  the  production  of 
alumina  than  others.  In  the  aluminium  industry 
a   low   content  of   iron   and   silica   is   desired. 


160 


ALUMINinM. 


especially  the  latter;  it  Is  therefore  usually 
found  advantageous  to  employ  the  red  bauxites, 
the  white  bauxites  being  used  preferably  in  the 


manufacture  of  sulphate  of  alumina.  The 
following  table  gives  the  composition  of  typical 
samples : — 


LocaUty    . 

Beaux 

Var 

Woobdn 

reisttfts 

Iriih 

Geoigia 

75 

12 

1 

12 

Red 

Wblte 

Dark 
eoloured 

Light 
eoloured 

Beddlih 
brown 

Yellow 

White 

Baw 

Fe.O,    . 
SiO,       . 
H,0       . 
TiO,      . 

60 

25 

3 

12 

50-62 
24-28 
1-7 
12-13 
01-4 

60.74 
0-3-3 
12-18 
14 

63-16 

23-55 

415 

8-34 

trace 

72-87 

13-49 

4-20 

8-50 
trace 

44-4 

30-3 

15-0 

9-7 

54-1 
10-4 
12-0 
21-9 

64-6 
2-0 
7-5 

24-7 

350 
38-0 

3-5 
21-5 

20 

60-5 
1-9 
3-3 

32-1 
2-2 

The  following  analyses  by  Leop.  Mayer  and  O.  Wagner  (DiuffL  poly.  J.  248,  213)  show  that 
the  appearance  of  bauxite  cannot  be  relied  on  as  a  criterion  of  its  yalne.  The  origin  of  the 
samples  is  not  given  : — 


1 

Appeanuiee 

Hygroscople 
molstare 

Oombined 
water 

AljOa 

FesOg 
3-67 

BiOi 

MnOs 

OaO 

IttO 

PiOi 

Pure  white 

2-33 

13-86 

29*80 

44-76 

_ 

2-75 

0-84 

1-47 

2 

Yellow  a 

1-03 

27-85 

43-22 

14-39 

10-43 

^ 

1-61 

— 

1-18 

3 

>*       •         * 

1-30 

27-70 

50-38 

11-68 

8-34 

trace 

trace 

trace 

0-61 

4 

Red        • 

1-34 

23-12 

33-86 

25-69 

12-41 

2-42 

trace 

— 

0-53 

5 

»f          •         * 

1-31 

23-81 

4618 

22-05 

4-82 

— 

0-89 

— 

0-66 

6 

ff                    •                  a 

0-95 

20-83 

6210 

611 

5-06 

2-01 

3-20 

trace 

trace 

7 

M                   •                 • 

117 

4-75 

21-86 

3-75 

60-10 

■^ 

6-06 

2-49 

trace 

The  amount  of  bauxite  mined  in  1907  was 
260,000  tons,  three-fifths  of  which  was  produced 
in  France.  In  1913  the  production  was  533,000 
tons  distributed  ss  follows:  United  States  210,000, 
France  309,000,  Great  Britain  6000,  other 
countries  8000.  During  the  period  1914-1918 
no  reliable  returns  are  available,  but  it  is  certain 
that  the  output  was  much  larger.  That  for  the 
United  States  alone  was  569,400  tons  in  1917, 
and  British  production  15,000  tons.  New  de- 
posits were  opened  up  in  Dafmatia  and  Hungary, 
the  latter  country  contributing  59,000  tons  in 
1915.  Increased  production  of  1^"™^^^°^  ^"^^ 
aluminium  salts  account  for  457,000  tons.  The 
more  recent  applications  of  bauxite  to  the  pro- 
duction of  alundum,  abrasives  and  refractory 
materials  for  bricks  and  furnace  linings  took  up 
112»400tons. 

For  the  manufacture  of  the  purest  form  of 
alumina  the  bauxite  is  first  roughly  powdered 
and  calcined  to  get  rid  of  water  and  any  oiganic 
matters.  It  is  then  more  finely  ground  and 
introduced  gradually  with  agitation  into  kiers 
containing  caustic  soda  solution  of  1'45  sp.gr. 
The  kiers  are  now  closed  and  the  charge  heated 
for  some  hours  under  high-pressure  steam — 
about  70-80  lbs.  The  contents  of  the  kiers 
are  then  transferred  to  the  filter  presses,  and 
the  filtrate  further  cleared  through  wood  pulp 
in  lead-lined  veto.  The  liquor  contains  sodinm 
aluminate  NaAlO,,  which  may  be  decomposed 
by  passing  carbon  dioxide  into  it,  but  it  is  now 
more  usual  to  adopt  the  Ba^er  method  of  pre- 
cipitating the  aluminaa  This  method  depends 
oc  the  fact  that  the  addition  of  alumina  effects 
the  decomposition  of  the  aluminate  and  throws 
down  some  70  p.c.  of  the  alumina.  The  dis- 
Bolved  liquor  now  contains  alumina  and  soda 
in    the   proportion   Alfi^ :  Na,0  : :  1  :  6.    The 


precipiteted  hydrate  of  alumina  is  allowed  to 
settle,  and  the  liquor  with  ite  undecompoeed 
portion  is  run  off  mto  weak-liquor  tanks.  The 
hydrate  is  filter-pressed,  sufiicent  being  left  in 
the  vat  to  serve  as  precipitant  for  the  next 
chaTge.  The  weak  liquor  may,  alter  concentra- 
tion, be  used  over  again  for  reacting  upon  a 
further  amount  of  bauxite. 

The  press  cake  conteining  the  impurities 
removed  in  the  treatment  of  banxito  con- 
utitutes  usually  over  30  p.c.  of  the  bauxite, 
whether  the  wet  process  of  extraction  or  the 
dry  fusion  process  with  sodium  carbonate  be 
used.  In  the  latter  case,  the  residue  has  been 
successfully  applied  in  the  removal  of  sul- 
phuretted hymt>gen  from  coal — or  from  exit 
gases  of  other  products.  The  residue  from  the 
wet  process  is,  nowever,  inactive  in  this  respect, 
but  may  be  transformed  into  a  condition  in 
which  it  is  very  effective. 

The  hydrate  of  alumina  so  obteined  ought  to 
contain  less  than  0*5  p.c.  of  mineral  impurity, 
iron  and  silicon  being  the  more  objectionable 
impurities.  To  bring  it  into  a  suitoble  physical 
condition  for  use  in  the  reduction  furnaces  it 
must  be  calcined  at  1100''-1200^  so  that  it 
shows  no  tendency  to  give  up  moisture  when 
used  in  the  furnace  or  to  absorb  moisture  when 
exposed  to  air. 

The  alumina  of  to-day  is  superior  to  that  of 
twenty  years  aso,  and  the  cost  of  production 
less  than  one-half.  It  constitutes,  however, 
about  one-fifth  of  the  whole  cost  of  manufacture 
of  aluminium,  and  many  processes  have  been 
brought  forward  witii  a  view  to  improve  or 
cheapen  the  product.  Of  these  may  oe  men- 
tions the  patente  of  Peniakoff  (Eng.  Pat. 
Nov.  19,  1895,  Mar.  18  and  May  13,  1896,  ftc). 
Endeavours  have  been  made  to  obtain  alumina 


ALUMINIUM. 


161 


of  sufficient  purity  from  bauxite,  clay,  felgpar, 
or  kaolin  by  electrically  heating  them  with  iron 
(or  ita  oxide),  carbon  and  cryolite,  thus  sepa- 
rating feiTosilicon  from  alamina ;  Moldenhauer 
(J.  Soc.  Chem.  Ind.  1909,  148),  Sinding-Larsen 
{ibid.  1908,  409),  Tone  .  (Electrochem.  and 
Metalluiff.  Ind.  1909,  35),  Hall  (J.  Soc.  Chem. 
Ind.  19(»,  49).  Recently  Serpek  has  proposed 
to  prepare  alamina  by  forming  the  carbide  and 
acting  upon  this  witn  producer  gas  consisting 
of  77  p.c.  nitrogen,  23  p.c.  carton  monoxide, 
and  a  little  carM>n  dioxide.  He  claims  that  a 
tolerably  pure  nitride  of  aluminium  is  formed, 
and  this  decomposed  by  steam  yields  alumina 
and  ammonia  (Journal  du  Four  Electrique, 
315,  1 ;  J.  Soc.  Chem.  Ind.  1911,  26 ;  Fr.  Pat. 
406712  and  418059).  Many  other  patents  haye 
been  taken  out  with  the  object  of  producing 
alamina  or  nitride  with  the  use  of  clay  or  other 
crude  materials  in  place  of  the  purifiea  iJumina, 
or  as  means  of  procuring  alumina.  Amongst 
these  may  be  mentioned  Cowles'  process  (Journal 
du  Four  Electrique,  1913,  176),  Child's  process 
(Met.  and  Chem.  Eng.  1913,  231),  Peacock's 
proposal  to  use  feli^>ar  (2.e.),  the  Badische 
patent  (Chem.  Trade  Joum.  April,  1911),  as 
well  as  methods  of  extraction  from  alunite  with 
the  recoyery  of  alkaline  salts  (Waggaman  and 
Cullen,  J.  Soc  Chem.  Ind.  1916,  1217),  and 
Hershmann  (U.S.  Pat.  1915  and  1916).  Serpek's 
process  has  also  undergone  considerable  deyelop- 
ments  in  operations  on  the  laige  scale  at  St. 
Jean  de  Maurienne.  See  also  J.  Soc.  Chem.  Ind. 
1913,  509 ;  Met.  and  Chem.  Eng.  1913,  137. 

The  Making  of  Carbon  EMrodes. — Bitumi- 
nouji  coal,  antiiradte,  retort  carbon,  natural  or 
artificial  graphites,  soot  and  oil-coke  are  all 
materials  which  haye  from  time  to  time  been 
uaed'in  the  production  of  carbon  electrodes.  In 
decidii^  which  of  these  materials  should  be 
used,  account  must  be  taken  of :  (a)  Supply 
and  cost  of  raw  material;    (6)  ash  content; 

(c)  amount   of  yolatile    matter  and   sulphur ; 

(d)  conductiyity  for  electricity  and  heat.  It 
must  also  be  understood  that  electrodes  used 
for  the  production  of  aluminium  differ  in 
character  from  those  used  for  lighting  or  for 
the  production  of  calcium  carbide  and  many 
other  purposes  where  graphitisation  of  the 
carbon  is  an  adyantage  and  the  presence  of 
mineral  matter  is  quite  permissible  and  eyen 
necessary.  The  graphitisation  of  amorphous 
carbon,  which  must  contain  mineral  impurities, 
is  indeed  effected  by  exposing  it  to  a  high 
temperature  under  electrical  heating. 

It  is  said  that  at  the  temperature  employed 
the  iron  yolatiliaes.  Be  this  as  it  may,  tne  ash 
of  such  carbon  contains  a  considerable  amount 
of  oxide  ol  iron.  Aluminium,  boron,  silicon, 
and  other  elements  which  form  carbides  can  be 
need  as  graphitising  agents,  as  also  to  some 
extent  the  oxides  of  these  elements. 

Graphite  or  giaphitised  electrodes  have  at 
1000**  C.  about  5  times  the  electrical  con- 
ductiyity of  coke  blocks  and  8  to  10  times  the 
thermal  conductiyity,  but  it  is  now  recognised 
that  these  properties,  advantageous  in  some 
respects,  are  not,  however,  favourable  to  the 
efficient  working:  of  reduction  furnaces. 

It  may  be  taken  that,  so  far  as  it  is  capable 
of  reduction  in  the  aluminium  furnace,  the 
mineral  ash  contained  in  the  carbon  alloys 
Vol.  L— T. 


itself  with  the  aluminium,  as  also  the  foreign 
matter  present  in  the  alumina.  The  amount  of 
alumina  used  should  be  about  double  that  <^ 
the  aluminium^  resulting  therefrom,  and  the 
electrode  consumption  about  one-half  of  the 
aluminium,  so  that  an  estimate  may  be  made 
of  the  impurity  as  silicon  contained  in  the 
metal.  Assuming  the  silica  in  the  alumina  and 
in  the  electrode  together  as  0'4  p.o.,  in  each 
case,  the  amount  of  silicon  in  the  metal  will  be 
yeiy  nearly  0*2  p.o. 

Similar  considerations  ayply  to  the  iron  con- 
tent of  the  metal,  though  tnis  may,  by  reason 
of  operations,  much  exceed  the  amount  of  iron 
contributed  by  the  alumina  and  electrodes. 

The  electrical  resistance  is  in  microhms  per 
cubic  inch  of 

0»  1000" 
Amorphous  oarbon(pressed)  1*63  1*45 
Graphite  carbon  .  .  .  0*42  0'25 
Electrodes  for  aluminium  .3*00    2*60 

The  resistanoe  per  cubic  centimetre  would  be 
2  '54  times  these  values.  ( For  further  detail.  The 
Electric  Furnace,  Stansfield,  or  the  pamphlet 
issued  by  the  Acheson  Graphite  Ck).,  may  be 
consulted ;  also  Met.  and  Chem.  Eng.  1915,  23.) 
In  addition  to  low  resistance  to  the  electrical 
current,  it  is  desirable  that  electrodes  should  be 
of  low  conductivity  for  heat,  that  they  should 
be  sufficiently  hard  and  resistant  to  superficial 
oxidation,  of  low  porosity  and  of  as  even 
character  as  possible  throughout  their  whole 
mass. 

To  produce  electrodes  having  these  qualities 
the  materijil(oil  coke,  pitch  coke,  and  anthracite, 
used  separately  or  mixed)  must  be  carefully 
selected,  ground,  calcined,  and  subjected  to 
hie h  pressure  with  the  admixture  of  tar  or 
other  material  to  act  as  binder.  The  blocks 
are  baked  at  a  temperature  of  about  1200^  to 
1300°  in  a  kiln,  in  principle  resembling  a  pottery 
kiln,  the  surface  of  the  blocks  being  protected 
from  oxidation  by  being  embedded  in  carbon. 
The  permissible  current-density  for  good  elec- 
trodes of  this  type  is  in  the  neighbourhood  of 
8  aniperes  per  square  inch  of  transverse  section. 
For  further  details  and  description  of  Mendheim 
and  other  kilns  suitable  for  oaking  the  blocks, 
reference  may  be  made  to  Die  KiinstUchen 
Kohlen,  by  Julius  Zellner.  Also  to  Chem.  and 
Met.  Engineering,  vol.  xix.  179,  where  an 
illustration  of  a  more  modem  type  of  kiln 
known  as  the  Meiser  Kiln  is  shown.  Various 
types  of  tunnel  furnaces  are  also  in  use  for  this 
purpose  (and  for  baking  pottery  and  bricks). 
The  connection  of  the  carbon  blocks  with  the 
anode  beam  carrying  the  current  may  be  effected 
by  means  of  an  iron  claw  let  into  the  block  or  a 
copper  hanger  fitted  into  it  by  a  screw  contact 
or  Dy  other  devices.        ^ 

The  Reduction  Furnaces, — These  oonsist 
essentially  of  an  iron  casing  lined  with  carbon, 
the  eeneral  character  and  arrangement  of  which 
is  shown  in  transverse  section  below.  The 
electrodes  vary  in  size  and  form  in  different 
works,  and  are  not  necessarily  arranged  in  two 
rows  as  indicated  in  the  figure.  Their  total 
sectional  area  is,  however,  iSways  adapted  to 
the  current  to  be  used  and  good  electrodes  will 
act  satisfactorily  under  a  current-density  of 
about  8  amperes  to  the  square  inch.    The  lower 


169  ALUM 

put  of  the  carbon  body  wrrea  aa  tha  cathode, 
or  a  special  form  of  cathodo  ii  let  into  the 
oarboD  at  the  base  of  the  famaoe.  In  starting 
a  fumaoe  it  is  usual  to  introdnoe  Qnt  the  oryoUte, 
which  is  brought  to  a  Rtft(«  o(  fusion  by  elactrical 
heating.     Alnmimi  is  then  fed  in  gradually  at  the 


moDozide,  according  to  the  eqnatioD 
Al.O,  +  3C  =  2A1  +  SCO 
but  thrae  is  little  donbt  that  primarily  oarbon 
dioxide  i«  formed,  and  the  change  should  be 

ZAI,0,  +  30  ~  4A1  +  300, 
In  the  former  case  the  carbon  used  would 
be  two-thirds  of  the  weight  of  the  aluminium 
prodnoed,  whilat  in  the  latter  it  would  be  one- 
third,  lu  piactice  the  ratio  of  carbon  to  alami- 
uium  liea  between  these  extremes. 


The  production  of  alaminium  is  discon- 
tinnoDS,  for  about  2  hours  after  the  proper 
charge  of  alnmina  has  been  added  tbe  voltage 
of  the  fnroHce  rises  rapidly  and  affords  an 
indication  that  more  aluniina  mnst  be  added. 
The  aluminium  collect*  at  the  bottom  of  tbe 
bath  of  electrolyte,  and  is  tapped  oS  at  stated 
periods,  either  every  day  or  at  longer  intervals. 
The  ndaction  of  alumina  by  electrolytic  methods 
on  a  laboratory  scale  is  beeet  with  difficulties : 
an  aooount  of  experiences  in  this  direction  is 
given  in  papers  by  Neumaoa  and  OUen  (Hct. 
and  dtem.  Engineering,  IfllO,  186),  and  Tucker 
{Ond.  1909,  315).  The  metal  is  subaequently 
re-melted  and  oast  into  notch  bar  slabs  or  Uocla. 
The  blocks  are  brolien  down  in  heavy  roilii  and 


further  brouaht  down  into  sheet,  Hetal  lAtob 
haa  been  subject  to  much  oold  work  in  rolling 
is  in  a  stressed  condition.  To  render  it  homo- 
geneous it  is  exposed  to  an  annealing  prooew 
at  about  400°.  The  resulting  sheet  is  ultimately 
obtained  according  to  details  of  treatment  in 
soft,  medium,  or  bard  condition.  Tbe  metal 
may  also  be  (k«wn  into  wire  or  extruded  in  large 
masses  either  in  solid  sections  or  in  tube. 

Phytieal  Proptrtia. — Commercial  ainminium 
is  a  metal  with  the  whiteness  of  tin.  It  has 
been  obtained  in  crystals  resembling  octahcdr«, 
and  is  very  slightly  magnetic 

Its  Bpeci6c  heat  is,  at 
-lOO-        01893      I      300"        0-243* 
ty        0-2098  600°        0'2739 

100°        0-2230     I      6HI°        03200 
{Schmite,  Proo.  Roy.  Soc  72,  177). 

The  total  heat  required  to  bring  a  Uloj^ramme 
of  aluminium  from  0°  to  629''  is  239,400  caU., 
and  its  Eatent  heat  of  fusion  is  usually  talum 
as  SO  calories  per  gram.  Laachtschenko  (J. 
Chem.  Boo.  1913,  Abet.  427)  found  for  metal 
of  09  p.c.  purity  the  value  71.  It  melts  at 
OIM'S"  (Heycook  and  Neville),  667-3°  (Holbom 
and  Day),  tbe  melting-point  being  depeodent 
(as  are  other  phymoal  properties)  on  its  purity. 
Small  araonnts  of  siljcon  and  iron,  which  are 
always  present,  have  a  considerable  effect  on 
ltd  behaviour,  both  phjrsically  and  in  contact 
with  reagents.  Loreni  found  its  conductivity 
tor  heat  at  0°  03436,  at  100°  03619  i  whilst  ' 
Jaeger  and  Drssselhorst  for  metal  containinir 
0-S  p.c.  iron  and  0'4  p.o.  copper,  found  0'4923 
at  100°.  Similarly  the  elecCricaJ  conductivity 
of  aluminium,  taking  oopper  as  100,  it  at 
follows:  08-6  p.o.  purity,  66;  99  p.c,  69; 
99-Ep.c.,61  J  HpecificresiBtance, 2*7-2-8 microhms 


alteration 

m  lei^)  U  7462  as  compared  with  11.360  for 
oopper,  and  the  torsion  moduli  of  theee  metal* 
are  3360  and  4460  respectively. 

The  specific  gravity  of  the  moltwi  metal 
it  2-64,  and  of  the  cast  metal  is  about  266 ; 
this  may  be  increased  by  rolling.  Its  thermal 
expansion  is  given  by  the  formula  li=^I-f  22^ 
-f  0-0091')  10-*J  (Jaeger and Scheel).  Iteipanda 
on  fusion  to  the  extent  of  4-8  p.e.  (To^et). 
Tha  metal  eipandt  in  volume  from  0°C.  to 
melting  point  6-1  p.c.,  after  fusion  n^aches  10-9 
p.c,  and  at  800°C.  1S-4  p.c  In  faardoesa  It 
resembles  silver,  and  the  pure  metal  is  softer 
than  the  impure.  It  becomes  more  elastic  and 
also  harder  by  hammering  and  tollinif.  and  kt 
capable  of  bemg  drawn  down  to  i 
inch  in  thickness,  or  rolled  into  pL 
into  foil  to  i^  inch  thick.     It 

dated,  or -* 

powder  (Guillet,  J.  S 
which  is  largely  employed  as  '  thermite,' 
aluminium  paint.  The  tensile  strength  of 
aluminium  is  12  to  13  tons  on  the  squara  inch, 
but  this  varies  with  the  temper  of  tbe  metal 
between  6^  and  161  to<>*  "a  the  aquam  inch, 
the  elongation  varying  in  the  invecte  manner 
Irom  23  p.c  te  14  p-c  6-mm.  wires  have  a 
tensile  stienfth  of  13  kg./mm.'and  3-mm.  wires 
a  strength  of  17  kg./mm.=.  Aluminium  haa  been 
largely  used  for  overhead  etectiioal ' 


iwire  of  rfo 
ite  or  beaten 
can  also  be 


ALUMINIUM. 


163 


and  it  possessea  many  advantages  for  such 
puipoaee  owing  to  its  lightness.  Its  specific 
gravity  being  only  A  of  that  of  copper,  and 
condnotivity  over  60  p.o.,  it  follows  that  an 
aluminiam  cable  has  double  the  efficiency  of  a 
copper  cable  of  the  same  weight  as  a  means  of 
conveying  current.  The  tensile  strength  of 
aluminium  is  affected,  of  course,  by  its  form, 
method  of  casting  and  mechanical  treatments 
Its  ultimate  strength  in  tons  per  square  inch  is 
in  castings  6  tons,  in  sheet  8  to  9  tons,  and  in 
wire  from  13  to  29  tons.  On  annealing  its 
strength  is  reduced  about  60  p.o.  and  its  duc- 
tility much  increased,  the  elonffation  being  4  to 
8  times  greater  than  when  it  is  m  the  head-rolled 
form. 

Although  corroded  in  the  atmosphere  of 
some  large  towns,  it  is  not  more  so  than  other 
metals  used  for  cables,  and  under  ordinary 
circumstances  it  merely  becomes  coated  with  a 
thin  film  of  oxide  which  acts  protectivdy 
(Kershaw,  J.  Soc.  Chem.  Ind.  1901,  133 ;  K. 
Wilson,  J.  Soa  Chem.  Ind.  1902,  1283 ;  1903, 
1093).  A  protective  coating  for  iosnlation 
purposes  can  also  be  product  (Mott,  J.  Soo. 
Chem.  Ind.  1904,  609;  Skinner  and  Chubb, 
J.  Soo.  Chem.  Ind.  1916,  360;  also  Eng.  Pat. 
9941,  April  24,  1911). 

There  has  been  great  difficulty  in  finding  a 
wholly  satisfactory  solder  for  the  metal,  and  one 
that  shall  resist  corrosion.  Dagger  (J.  Chem. 
Soo.  Ind.  1891,  436)  quotes  as  useful  for  heavy 
soldering  Al  12  pts.  Cu  8  pts.  Zn  80  pts.,  and  for 
light  soldering  Al  6  pts.  Cu  4  pts.  Zn  90  pts. 
A  satisfactory  flux  for  solderm^  consists  of 
NaCl  30  grams,  KCl  46  srams,  LiCl  16  grams, 
KF  7  grams,  NaHSOi  3  grams  (J.  du  Four 
Electrique,  1914,  868).  Joints  can,  however,  be 
made  by  autogenous  welding  with  an  oxyhy- 
drcmn  or  acetylene  flame  or  electrically.  Butt 
ana  other  joints  may  be  effected  by  various 
mechanical  devices  with  the  aid  of  fusion  at 
the  surfaces  or  by  a  casting  of  metal  around  the 
junctions. 

Applieatiana  of  Aluminium  in  the  Industries. 
—Castings  or  extrusions  of  the  metal  or  its 
alloys  are  used  in  the  construction  of  railroad 
cars,  motor-cars,  air-ships,  and  aeroplanes ;  for 
collector  bows,  field  coils,  and  other  details  in 
electrical  traction,  also  for  various  mechanical 
appliances,  such  as  pulleys,  &c.  Sheet  is  largely 
employed  for  spinning,  pressing,  or  stamping 
into  forms  suitable  for  cooking  vessels,  trays, 
drawers,  beakers,  and  similar  articles  of  domestic 
usoyor  in  works  operations.  TFire  and  extruded 
metal  is  employed  in  the  distribution  of  electrical 
current  either  by  means  of  soUd  or  stranded 
cable,  for  feeder  coimections  or  bus-bars.  In 
America,  on  the  Continent,  and  in  Canada  and 
other  Colonies  aluminium  is  used  for  overhead 
hiffh-tension  currents  ruiming  to  over  100,000 
v(Mts.  In  Great  Britain  its  use  is  confined  to 
lower-tension  currents  either  over  or  under- 
ground. 

Qranules  and  Notch  Bar  are  cast  in  this  form 
for  convenient  addition  to  molten  steel  during 
casting  with  the  object  of  securing  greater 
purity  and  density  of  the  steel.  In  the  form  of 
jnvder,  or  as  finely  granukUed  metal,  aluminium 
finds  application  in  the  thermite  welding  process, 
as  paint,  and  for  the  manufacture  of  high  explo- 
sives, such  as  ammonal.    In  consequence  of  the 


very  large  number  of  chemical  products  which 
have  practicallv  no  action  upon  aluminium,  the 
metal  is  now  being  used  with  advantage  in  a 
large  number  of  chemical  industries.  Tho 
folu>wing  may  be  quoted  as  processes  or  branch 
industries,  in  which  already  wide  applications 
in  the  construction  of  plant  are  being  found  for 
the  metal : — 

Manufacture  of  nitric  acid  and  guncotton, 
&c. :  oils,  fats,  soap,  glycerine,  oittanic  acids ; 
fine  chemicaU,  such  as  formaldehyde,  hydrogen 
peroxide,  ether,  extracts,  essences,  and  syrups ; 
foodstuffs,  gelatin,  jams,  etc. 

Also  in  the  caiming  industry,  suffar  refining, 
varnish  making,  brewing,  dyeing,  rubber,  paper, 
lithography,  and  printing. 

Unemical  Properties, — ^Aluminium  absorbs 
about  its  own  volume  of  hydrogen  (Delachanal 
and  Dumas,  J.  Soo.  Chem.  Sid.  1909,  308), 
which  is,  however,  expelled  on  heating  or  in 
vacud.  In  the  course  of  its  production  and 
treatment  aluminium  takes  up  gases  (chiefly 
hydrosen  and  nitrogen)  usually  in  such  quantity 
tnat  their  total  volume  is  from  7  to  20  p.c.  of 
that  of  the  metal.  Good  metal  tapped  from  the 
reduction  fumaoes  yields  5  to  10  p.c.  of  its 
volume  of  hvdrogcn  and  about  3  to  4  p.c.  of 
nitrogen.  After  re-melting,  especially  under 
unsutable  conditions,  it  is  found  to  contain 
more  hydrogen  and  alno  carbonic  oxide  and 
hydrooarbons.  An  ingot  of  metal,  which  had 
been  melted  and  allowed  to  cool  in  the  furnace 
very  slowlv,  was  highly  crystalline  and  found  to 
contain  of  its  volume  an  extraordinary  amount, 
viz.  86  P.O.  hydrosen,  7*6  p.c.  nitrogen,  and  4 
p.o.  carbonic  oxids  and  hydrocarbons.  It  is 
practically  unacted  upon  by  oxygen  at  ordinary 
temperatures,  but  if  finejy  divided  it  under- 
goes considerable  oxidation  at  400^,  or  even, 
though  less  rapidly,  at  lower  temperatures.  If 
sufficientiy  pure,  water  has  slight  action  upon  it, 
though  if  sodium  ia  present  in  the  metal  a  some- 
what greater  action  occurs.  This  is  accentuated 
if  copper,  brass,  or  other  metals  are  in  contact 
with  it.  A  recent  use  to  which  the  metal  has 
been  put  is  for  the  treatment  of  hard  waters, 
which  by  intimate  contact  with  the  metal,  are 
said  to  be  softened  and  become  less  liable  to 
form  incrustation  on  the  shell  of  the  boiler. 
The  halogen  elements  or  acids  readily  act  upon 
aluminium,  and  the  chemical  activity  of  the 
metal  is  such  that  a  laige  amount  of  heat  ia 
generated  on  combination  with  these  elements. 

The  very  great  affinity  which  aluminium 
possesses  for  oxygen  has  been  made  use  of  in 
the  application  of  '  thermite '  as  a  means  of 
reducing;  oxides.  Goldschmidt,  D.  R.  P.  96317 
(1896),  nas  thus  used  the  finely  divided  metal  in 
the  production  of  iron,  manganese,  chromium, 
nickel,  cobalt,  titanium,  boron,  molybdenum, 
tungsten,  vanadium,  and  other  metals. 

Keagents  which  readily  part  with  the 
halogens,  such  as  Sid^  and  rCl^,  also  attack  it, 
and  carbon  or  the  oxides  of  carbon  at  hiah 
temperatures  convert  it  into  the  carbide,  AI4C,. 
Mallet  (Chem.  Soo.  Trans.  1876,  340)  found  that 
molten  aluminium  is  acted  upon  by  nitrogen 
with  the  formation  of  nitride,  indeed  it  bums 
vigorously  in  an  atmosphere  of  nitrogen. 

If  brought  into  intimate  contact  with 
mercury  in  presence  of  moisture,  aluminium  is 
readily  converted  into  the  hydroxide,  and  when 


164 


ALUMINIUM. 


exposed  to  the  vapour  of  mercury  with  access 
of  air,  it  undei^oes  rapid  oxidation. 

Perspiration,  being  acid,  has  no  apparent 
effect ;  saliva,  on  account  of  its  slight  alkalinity, 
acts  very  slowly.  Aluminium  tubes  have  been 
used  for  insertion  in  the  human  body  where 
much  purulent  matter  was  present,  without 
perceptible  corrosion. 

Aluminium  when  fused  with  potash  or  soda 
is  unaffected  even  at  a  dull  red  heat,  but  the 
superficial  silicon  is  removed ;  metal  so  treated 
takes  a  good  *  matt.' 

For  Dumishin^  and  engraving  aluminium, 
the  ordinary  media  are  unsuitable.  According 
to  Mourey  and  others,  an  emulsion  of  equal  parts 
of  rum  and  oUve  oil  is  most  satisfactory.  The 
finish  of  manufactured  articles  is  improved  by  a 
frosted  appearance.  This  is  produced  by 
plunging  the  article  momentarily  into  caustic 
alkali,  washing  well,  and  immersing  in  dilute 
nitric  acid. 

Action  on  metallic  solutions. — Aluminium, 
especially  in  the  form  of  foil,  has  a  considerable 
action  on  many  salts  in  solution.  The  action  of 
sulphates  and  nitrates  is  usually  very  slow.  All 
chlorides,  except  those  of  the  alkalis  and  alka- 
line earths,  are  readily  decomposed,  even  alu- 
minium chloride  solution  dissolves  the  metal 
with  evolution  of  hydrogen.  Bromides  and 
iodides  have  corresponding  effects.  The  pre- 
sence of  chlorides  in  solutions  of  other  salts 
much  facilitates  their  action. 

From  a  neutral  or  feebly  acid  solution  of 
silver  nitrate,  silver  is  precipitated  slowly ;  from 
an  ammoniacal  solution  of  the  chloride,  silver  is 
rapidly  precipitated  as  a  crystalline  powder. 

From  the  nitrate  or  sulphate  of  copper,  pre- 
cipitation is  slow,  from  the  acetate  quicker, 
and  from  the  chloride  or  other  salt  in  presence 
of  sodium  chloride,  rapid  and  complete. 

Salts  of  mercury  are  decomposed  with  forma- 
tion of  an  amalgam.  Lead  and  zinc  are  readily 
precipitated  (v.  also  Cossa,  Zeitsch.  f.  Chem. 
[2]  6,  380  and  443 ;  Nicolardot,  J.  Soo.  Chem. 
Ind.  1912,  438). 

Action  of  dry  saits  and  oxides. — The  action 
of  aluminium,  when  heated  with  certain  salts 
and  oxides,  is  peculiar,  and  shows,  especially  at 
high  temperatures,  the  tendency  of  this  metal  to 
form  alaminates. 

It  is  not  affected  by  potassium  nitrate  except 
above  a  red  heat;  it  is  then  rapidly  oxidised 
with  formation  of  potassium  aluminate.  With 
alkaline  carbonates  combination  takes  place  at 
a  red  heat  with  separation  of  carbon,  and  with 
alkaline  sulphate  combination  takes  place 
suddenly  at  redness  with  explosive  violence; 
in  both  cases  aluminates  are  formed. 

When  finely  divided  aluminium  is  mixed 
with  oxide  of  copper,  lead,  or  iron,  combination 
takes  place  at  a  white  heat  only,  with  such  vio- 
lence as  freauently  to  shatter  the  crucible.  In 
the  case  of  lead  and  copper  pxides,  aluminates 
are  produced,  and  with  iron  an  alloy  of  iron  and 
alamimam  (Tissier). 

When  heated  with  silicates  or  borates, 
aluminium  liberates  silicon  or  boron,  forming  an 
aluminate  with  the  base.  Fused  silver  chloride 
is  reduced  to  metal ;  zinc  is  reduced  from  its 
fused  chloride,  whilst  magnesium  chloride  is 
not  affected  (Fhivitzky,  Ber.  6,  195).  The 
vapour  of  mercuric  chloride  is  reduced  with  such 


energy  by  heated  aluminium  that  the  metal 
fuses. 

Corrosion  of  aluminium. — ^The  question  of 
corrosion  is  one  which  is  of  the  highest  import- 
ance in  the  application  of  metals,  but  in  none 
more  so  than  m  the  case  of  aluminium  (Bailey, 
J.  Inst.  Metab,  ix.  79,  a^d  xxi.,  234). 

This  arises  not  only  from  the  considerable 
extent  of  the  usage  of  this  metal  for  culinary 
operations,  but  eSao  because  of  its  large  and 
extending  use  in  the  chemical  industries  and 
for  constructional  work  where  atmospheric  and 
other  agencies  are  to  be  reckoned  with. 

Speakinff  generally,  with  the  exception  of 
alkalis  and  mlts  with  an  alkaline  reaction, 
solutions  containing  less  than  5  p.c.  of  the 
reagent  have  very  Mtle  action. 

It  is  also  noteworthy  that  concentrated 
mineral  acids  or  organic  acids,  and  with  few 
exceptions  the  salts  of  these  react  very  slowly 
with  aluminium.  The  most  important  excep- 
tions are  hvdrochlorio  add  and  the  halogen 
acids  generaUy. 

It  is  essential,  however,  to  add  that  whilst 
this  general  statement  holds  good  at  ordinary 
temperatures,  action  is  very  greatly  aoceleratea 
by  a  rise  in  temperature,  and  especially  when 
the  reagent  approaches  its  point  of  ebullitioiL 
The  extent  to  which  aluminium  is  corroded  is 
also  largely  dependent  on  its  purity,  especially 
where  Uiis  is  lower  than  that  of  good  com- 
mercial metal,  say  99'2  p.c.,  or,  of  course  (though 
in  practice  this  is  irequently  overlooked), 
aluminium  is  in  contact  with  other  metak. 
In  the  notes  which  follow,  some  information 
is  given  as  to  the  corrosive  effects  of  those 
reagents  which  are  already  associated  with  tiie 
use  of  aluminium  in  the  industries,  and  references 
are  siven  to  details. 

The  numbers  stated  in  parentheses,  in  respect 
of  any  of  these  reagents,  express  the  milligrams 
of  metal  removed  per  100  square  centimetres  of 
surface  for  an  exposure  at  ordinary  tempeiatures 
of  24  hours,  wnen  the  concentration  is  ap- 
proximately 6  p.c.,  except  where  otherwise 
stated. 

Acetic  acid  (0*6)  (Lunge,  J.  Soc.  Chem. 
Ind.  1895,  592 ;  Seligmann  and  Williams, 
J.  Soc.  Chem.  Ind  1916,  88,  and  1917,  40^). 

Acetone  (Pikes,  Zeitsch.  angew.  Chem.  1914, 
52). 

Alcohol,  wines,  and  spirits  (Lunge,  {.c. ; 
Rudiger  and  Karpinski,  J.  Soc.  Chem.  Ind. 
1913,  41). 

Ammonium  hydroxide  (reaches  maximum 
with  2  p.c.  at  375)  (£.  K.  Davis,  Metal.  Ind.  1910, 
109). 

Barium  hydroxide  (370  for  oentinormal 
solutions). 

Beer  (Schdnfeld  and  Himmelfarb,  J.  Soo. 
Chem.  Ind  1912,  789  ;  Chapman,  I.e.  1912,  87  ; 
Bleisch,  Ic.  1912,  199 ;  Zikes,  l.c.  1913,  248 ; 
Trillat,  l.c.  1915,  883). 

Boric  acid  (0*3)  (Lunge,  I.e.). 

Bromine  acts  vigorously  on  aluminium,  alio 
chlorine  and  iodine. 

Butyric  acid  (0*2)  (Lunge,  l.c. ;  Seligmann 
and  Williams,  I.e.). 

Calcium  hydroxide  (285  for  a  oentinonnal 
solution). 

Citric  acid  (0*3)  (Limge,  ^.c). 

Formic  acid  (Seligmann  and  Williams,  j.c.). 


ALUMINIUM. 


165 


HydrocJdoTic  <icid  (7). 

Lactic  acid  (0*8)  (Lunge,  l.c,). 

Nitric  acid  (5)  (Seligmann  and  Williams, 
J.  Soa  Chem.  Ind.  1916,  666). 

Oxalic  acid  (6)  (Carpenter  and  Edwards, 
9th  Report  of  Alloys  Research  Committee). 

Pokusium  htfdroxide  (205  for  a  centinormal 
solution). 

Potassium  iodide  (1*3). 

Propionic  acid  (Seligmann  and  Williams, 
J.  Soc.  Chem.  Ind.  1916,  88). 

SalicyUc  acid  (1*1)  (Lunge,  {.c). 

Sodiuff^  chloride  (2). 

iSfea  water  (13)  (Carpenter  and  Edwards,  {.c). 

Sodium  hydroxide  (460  for  a  centinormal 
Bcdntion). 

Sodium  carbonate  (reaches  maximum  with 
0-5  p.c.  at  140). 

Sodium  bicarbonaU  (little  or  no  action). 

Sulphuric  acid  (7). 

Tartaric  acid  (0*3)  (Lunge,!  .c). 

It  should  be  realised  that  corrosion  measured, 
especially  in  the  cold  and  oyer  short  exposures, 
shows  in  many  cases,  a  much  higher  value  than 
would.be  the  case  for  prolonged  exposure,  owing 
to  the  formation  of  a  protective  coating.  This 
applies  particularly  to  weathering,  action  of 
ammonia,  and  certain  hydrates  and  salts,  and 
more  commonly  in  hot  solutions. 

With  the  fixed  alkalis  the  activity  is  pro- 
gressive with  increased  concentration,  and  also 
in  a  very  rapid  d^ree  with  hydrochloric  acid ; 
but  with  ammonia,  sodium  carbonate,  and  with 
sulphuric,  nitric,  and  acetic  acid  the  activity 
rises  to  a  maximum,  and  ultimately  falls  off 
rapidly,  so  that  with  the  hignest  con- 
centration the  action  is  slight.  Many  of  the 
results  ffiven  above  have  ^en  confirmed  by 
the  author  of  this  article  or  are  the  results 
of  unpublished  determinations  by  him.  It 
only  remains  to  add  that  the  following  bodies 
have  practically  no  action  on  aluminium : 
Acetone ;  acetylene;  benzol ;  tea  and  other 
similar  beverages ;  borax  ;  chlorides ;  sulphates 
and  nitrates  of  the  alkalis;  carbolic  acid; 
ether;  fats,  oils,  and  fatty  acids;  formalde- 
hyde ;  gallic  acid  ;  gelatin ;  glycerine ;  hydro- 
gen peroxide;  hydrogen  sulphide;  soap; 
sulphur;  sulphur  dioxide ;  chlorine. 

Potable  waters,  if  free  from  common  salt 
and  alkalis,  have  very  slicht  effect. 

Detection, — Compounos  of  aluminium,  when 
heated,  moistened  with  solution  of  cobalt 
nitrate,  and  again  strongly  heated  produce  a 
fine  Hky-blue  colour  {Thenard's  blue,  q.v.,  art. 
Cobalt). 

Aluminium  compounds  are  usuafly  colour- 
less. Silicates  and  other  compounds  insoluble 
in  acids  require  to  be  fii^ly  powdered,  mixed 
with  4  parts  of  sodium  carbonate  or  fusion  mix- 
ture, and  heated  strongly  in  a  platinum  crucible 
The  aluminium,  having  thus  become  converted 
into  sodium  aluminate,  is  dissolved  out  with 
hydrochloric  acid,  evaporated  to  dryness  to 
render  any  dissolved  silica  insoluble,  and  treated 
with  dilute  hydrochloric  acid.  The  aluminium 
is  then  present  as  chloride. 

Aluminous  solutions,  on  addition  of  an  alkali, 
give  a  white  gelatinous  precipitate  of  hydrate, 
soluble  in  excess  of  the  precipitant  and  in  acids. 
Ammonia  produces  the  same  precipitate,  which 
is  only  sligntly  soluble  in  excess,  and  is  entirely 


reprecipitated  on  boiling  off  the  excess  of 
ammonia  if  sufficient  ammonium  chloride  be 
present,  or  it  may  be  precipitated  by  COf 

Estimation. — ^Alununium  ia  usually  precipi* 
tated  as  the  hydrated  oxide  A1,0,,3H,0. 

For  this  purpose  the  solution,  which,  in  pre- 
sence of  alkalis  or  alkaline  earths,  is  mixed 
with  excess  of  ammonium  chloride,  is  treated 
with  a  slight  excess  of  ammonia,  and  the  solu- 
tion boiled  until  the  free  ammonia  is  expelled. 
The  hydrate,  having  thus  become  totally  pre- 
cipitated, is  filtered,  well  washed,  dried  and 
heated  in  a  platinum  crucible,  the  heat  being 
finally  raised  to  bright  redness  to  constant  wei|;ht 
over  the  blowpipe.  The  weighed  residue  consists 
of  anhydrous  oxide,  Al^Og,  and  contains  53  p.c. 
of  aluminium.  The  separation  from  otoer 
metals  is  not  difficult.  The  heavy  metaJs  may 
be  precipitated  from  the  acid  solution  by  sulphu- 
retted hydrogen,  leaving  the  iduminium  in  solu- 
tion, whilst  the  precipitation  in  presence  of 
ammonium  chlorioe  in  excess  separates  it  from 
the  alkaUs  and  alkaline  earths.  From  chro- 
mium and  iron  the  separation  is  less  simple. 
Chromium  may  be  separated  as  follows : — ^The 
precipitated  oxides  are  dried,  mixed  with  2 
parts  potassium  nitrate  and  4  sodium  carbonate 
and  fused  in  a  platinum  crudible.  Alkaline 
chromate  and  aluminate  are  thus  produced.  The 
mass  is  digested  with  water  ana  a  small  quan- 
tity of  potassium  chlorate  and  of  hydrochloric 
acid  are  then  added,  and  the  solution  is  evapo- 
rated to  a  syrup,  with  occasional  addition  of 
potassium  chlorate  to  destroy  the  excess  of 
hydrochloric  acid  and  prevent  its  reducing 
action  on  the  chromate.  The  aluminium  in  the 
diluted  solution  is  precipitated  as  above  by 
ammonia,  leaving  the  chromate  in  solution. 

For  the  separation  from  iron,  the  precipitated 
hydrated  oxides  are  dissolved  in  the  minimum 
quantity  of  hydrochloric  acid  and  treated  with 
an  excess  of  pure  strong  potassium  hydroxide 
solution,  boiled  for  a  few  minutes,  diluted, 
filtered,  and  well  washed.  The  ferric  oxide  is 
thus  precipitated  and  separated  from  the  soluble 
alumma.  The  solution  and  washings  are  acidi- 
fied with  hydrochloric  acid  and  precipitated 
by  ammonia.  On  account  of  its  solvent  action 
upon  glass,  the  treatment  with  potash  should 
be  penormed  in  a  porcelain  dish,  which  is  much 
less  attacked,  or,  preferably,  in  one  of  silver. 

Commercial  Analysis  of  Aluminium, — ^The 
direct  determination  of  aluminium,  constituting 
as  it  does  usually  over  99  p.c.  of  the  metal  under 
examination,  presents  many  difficulties.  It  has 
been  proposed  to  estimate  the  aluminium  by 
ascertaining  the  volume  of  hydrogen  evolved  on 
dissolving  it  in  hydrochloric  acid  or  the  amount 
of  chloride  formed,  but  the  errors  to  which  such 
a  determination  is  liable  are  too  great  to  admit 
of  sufficient  accuracy ;  moreover,  the  impurities 
usually  present  give  rise  to  corrections  which 
detract  n:om  the  nmplicity  of  the  method  and 
complicate  the  result.  The  solution  in  caustic 
soda  is  preferable  to  this,  the  iron  and  copper 
remaining  as  a  black  residue,  but  the  silicon,  in 
part,  at  least,  reacts  with  caustic  soda,  so  that 
even  in  this  case  the  hydrogen  evolved  cannot 
be  taken  as  a  measure  of  the  aluminium  present. 
In  these  circumstances  it  is  customary  to 
determine  the  impurities  and  arrive  at  the 
amount  of  aluminium  by  difference. 


106 


ALUMINIOH. 


The  impuritieB  generally  present  in  quantity 
are  iron,  amoon,  and  sometimes  copper.  Minuto 
amounts  of  sodium,  carbon,  and  nitrogen  are 
also  contained  in  the  metal,  but  these  should  not 
greatly  affect  the  result  unless  when  dealing 
with  specially  impure  metal.  Commeroiallv, 
therefore,  iron  ana  silicon  alone  are  usually 
estimated.  For  the  iron,  the  metal  is  dis- 
solved in  caustic  soda,  and  this  solution  on 
aoidulation  with  sulphuric  acid  yields  sulphates 
of  alumina  and  iron  which  redissolve  in  the  acid, 
whilst  the  presence  of  copper  is  indicated  by  the 
appearance  of  a  black  residue.  The  amount  of 
iron  is  finally  determined  by  titration  with 
potassium  permanganate.  For  the  nlicon,  the 
metal  is  digested  with  hydrochloric  acid  in 
presence  of  nitric  acid  (to  avoid  volatilisation  of 
an^  silicon  as  chloride)  forming  a  turbid  solution 
owinx  to  the  separation  of  the  silica.  This  is 
then  Doiled  down  with  sulphuric  acid  until  white 
fumes  of  ibia  acid  appear.  The  aluminium  and 
iron  salts  are  thus  converted  into  sulphate,  and 
redissolve  on  digestion  with  water,  the  silica 
being  left  in  suspension. 

^ter  filtration  and  washing,  the  silica  is 
strongly  heated  and  weighed.  Copper  mav  be 
estimated  as  sulphide*  or  the  black  residue  above 
mentioned  may  be  dissolved  and  the  copper 
estimated  colorimetrically.  If  the  amount  of 
8odium  is  to  be  found,  the  metal  must  be  dissolved 
in  nitric  add,  boilin£|  acid  of  60  p.c.  strength 
being  used.  The  scuution  is  boiled  down  to 
dryness  and  exposed  to  a  dull  red  heat  so  long 
as  red  fumes  appear.  The  residue  is  extracted 
with  water,  care  being  taken  finally  to  remove 
all  alumina  or  other  metals  precipitated  hy  the 
ordinai-y  reagents.  Ultimately  the  sodium  salt 
remaining  may  be  converted  mto  sulphate  and 
we^;hed  as  such.  For  fuller  details  a  paper  by 
Seligmann  and  Willott  may  be  consulted  ( Joum. 
Inst.  Metals,  vol.  iii.  p.  138). 

For  general  analytical  details,  the  following 
sources  of  information  may  be  consulted: 
Moissan  (Gompt.  rend.  121,  851) ;  Gouthi^re 
(Analyst,  21,  270) ;  Jean  (Rev.  Chim.  Indust.  8, 
5) ;  Withey  (Joum.  Inst.  Metals,  xv.  207).  The 
better  qualities  of  commercial  metal  should  not 
contain  more  than  0*5  p.c.  of  iron  and  silicon 
together,  nor  more  than  0*05  p.c.  of  sodium.  It 
is,  however,  veiy  doubtful  whether  sodium  is 
present  in  the  metallic  form. 

Allays. — ^The  addition  of  quite  small  quanti- 
ties of  aluminium  to  certain  metals  (e.g.  copper 
and  iron)  has  a  profound  effect  in'modifving  the 
properties  of  these  metals.  Likewise  the  addi- 
tion of  small  quantities  of  certain  metals  {e.g, 
Fe,  Mn,  Si,  £c.)  to  aluminium  effects  con- 
siderable change  in  the  properties  of  this  metal. 
The  addition  of  0*1  p.c.  of  aluminium  to  copper 
brings  down  its  conductivity  23  p.c. ;  the 
addition  of  zinc,  copper,  nickel,  iron,  or  man- 
ganese to  aluminium  is  accompanied  by  con- 
siderable augmentation  of  the  tensile  stren^h. 
The  alloys  of  aluminium  may  be  classified  mto 
bronzes,  casting  alloys,  and  rolling  alloys, 
according  to  their  properties.  The  true  bronzes 
consist  of  copper  and  aluminium  alone,  but  there 
are  many  binary  (and  ternary)  alloys  which 
contain  metals  other  than  copper  and  yet  suffi- 
ciently resemble  bronze  to  be  classed  along  with 
it.  The  bronzes  proper  chiefly  employed  are 
gold  bronze,  containing  3  to  5  p.c.  of  aluminium ; 


steel  bronze,  with  8*5  p.c.  Al  and  some  silicon ; 
acid  bronze,  with  10  p.c.  Al.  The  copper 
bronzes,  with  90, 02*5, 05  and  07*5  p.c.  of  copper, 
are  all  good  alloys,  showing  homogeneitv  and 
freedom  from  crystallisation.  Theiy  are  of  great 
hardness  and  high  tensile  strength. 

Such  alloys  possess  very  valuable  properties, 
the  ultimate  stress  of  the  00  p.c.  alloy  being 
38  tons  to  the  sq.  inch,  and  they  have  the 
further  valuable  property  of  being  practically 
noncorrodible  by  sea-water;  this  property  is 
also  shown  venr  markedly  by  bronzes  containing 
mancanese.  These  bronzes  in  hardness  and 
tensue  strength  compare  favourably  with  the 
best  steel,  and  are  similarly  affected  by  temper- 
ing.  The  alloys  high  in  aluminium  and  low  in 
copper  are  also  of  great  commercial  value;  a 
bronze  with  4  p.c.  copper  by  rolling  and  drawing 
showed  a  steady  increase  in  tensile  strength 
from  9*6  tons  to  20  tons  to  the  sq.  inch. 

A  small  percentage  of  manganese  increases  the 
tensile  strength  of  aluminium  without  affecting 
its  ductility,  'but  large  proportions   of   man- 

Sanese  increase  the  strength  and  lessen  the 
uctility. 
For  further  information  reference  may  be 
made  to  the  eighth  report  of  the  Alloys  Research 
Committee  of  the  Inst.  Mech.  Engmeers  (Car- 
penter and  Edwards),  and  to  the  ninth  report 
(Rosenhain  and  Lantsbeny),  and  tenth  report 
(Rosenhain  and  Archbutt),  also  to  The  lletal 
Industry,  1909,  186  (Hioms);  Schirmeister, 
J.  Soc.  Chem.  Ind.  1916,  894 ;  also  J.  du  Four 
Electrique,  1914,  700.  The  composition  of 
other  bronzes  used  industrially  is  given  in  the 
following  table : — 


Al 

Cu 

Zn 

8n 

Ni 

CSr 

Mg 

Hercules 

bronze 

2 

65 

83 

— 

— 

— 

..ii. 

Chromium 

bronze 

95*75 

4 

^— 

— 

— 

0*25 

— 

Duralum 

79 

10* 

«— 

— 

— 

-^ 

U 

Partinium     . 

88*7 

6-8 

4-5 

— 

— 

-— 

^-. 

Gro8smann*s 

alloy  . 

87 

8 

— 

5 

— 

— 

— 

Argentan 

7 

70 

— 

— 

23 

— 

— 

Hercules 

metal  (No.  3)- 

1-5 

61   37*5 

1 

-^ 

~"~    — 

""• 

*  Pbofiiihorised  copper. 

The  aluminium  alloy  containing  20-50  p.c 
of  copper  or  nickel  is  brittle,  as  is  the  alloy  with 
35  p.c.  of  manganese. 

Rolling  Alloys, — ^Aluminium  alloys,  containing 
3  to  4  p.c.  of  copper  or  1*5  to  5  p.c.  of  nickel, 
roll  well,  as  do  many  other  alloys  containing 
copper  and  zinc,  the  former  in  small  quantity, 
amounting  to  from  1  to  3  p.  c,  and  the  latter  10 
to  12  p.c.,  or  even  more. 

Magnalium  consists  of  aluminium  alloyed 
with  2  to  10  p.c.  of  magnesium.  This  alloy  is 
Ughter  than  aluminium,  and  in  strength  and 
workability  equal  to  good  brass.  Duralumin 
is  a  very  important  alloy  containing  3*5  to  5*5 
p.c.  Cu,  0*5  to  0*8  p.c.  of  Mn,  and  0'5  d.c.  Mg. 
An  account  of  this  alloy  is  to  be  found  in  the 
discussion  on  Tenth  Report  of  the  Alloys  Re- 
search Committee;  also  Met.  Industry,  1910, 


ALUMINIUM. 


167 


303  and  413 ;   and  Met.  and  Chem.  Eng.  1910, 
647. 

Casting  alloys  are  also  largely  used,  consisting 
meet  frequently  of  faluminium,  zinc,  and  copper 
in  varying  proportions  (Biohaids,  Eng.  and 
Mining  Joum.  1908,  715).  Magnalium  admits 
of  introduction  with  advantage  of  small  quanti- 
ties of  copper  and  nickel  without  unduly 
raising  its  specific  gravity.  The  tensile  strength 
and  hardness  of  these  aJloys  are  considerable,  and 
they  are  said  to  be  resistant  to  atmospheric 
corrosion  (Bamett,  J.  Soo.  Chem.  Ind.  1905, 
832).  Taps,  tuyeres,  and  the  like  are  made 
from  an  auoy  composed  of  aluminium,  to  which 
12  p.c.  Cd,  6  p.o.  Ou,  5  p.o.  Sn,  2  p.c.  Ni  are 
added.  Pedestals  are  also  made  of  aluminium, 
containing  14  p.o.  Sb,  1*2  p.c.  Cu,  12  p.c.  Sn, 
37  p.a  Zn,  and  0*8  p.c.  Fb ;  coppei;  with  10  p.o. 
Al  and  1  p.c.  Mn,  is  an  excellent  hard  alloy  for 
beazinff  metal  or  tool  steel;  horse-shoes  are 
made  from  a  ternary  alloy  of  aluminium  con- 
taininff  either  12  p.c.  Cu  and  10  p.c.  Zn,  or  5  jp.o. 
Cu  and  10  p.o.  Sn.  Many  aUoys  of  alumimum 
resist  acid  corrosion  to  a  remarkable 
degree,  and  even  if  cooking  utensilB  are  made 
from  an  aluminium  copper  alloy.  Carpenter  and 
Edwards  have  shown  that  when  corrosion  does 
occur  the  copper  is  not  dissolved  out,  amd  hence 
there  is  no  danger  of  poisoning  in  using  such 
vessels,  since  the  salts  of  aluminium  have  no 
toxic  action. 

An  improvement  is  effected  by  the  addition 
of  alumimum  to  brass.  An  alloy  containing 
alominium  2'5  p.a,  copper  70  p.c,  and  zinc 
27*5  p.c.,  is  said  to  show  nearly  double  the 
tenacity  and  considerably  more  than  double 
the  elongation  of  ordinary  cast  brass. 

The  presence  of  tin  in  aluminium  renders  it 
more  fusible  and  brittle.  According  to  Bourbouze 
(Compt.  rend.  102,  1317),  an  alloy  of  aluminium 
100  and  tin  10  is  strong,  easily  worked,  may  be 
soldered  as  easily  as  brass,  is  whiter  and  less 
affected  by  reagents  than  aluminium,  and  is 
very  suitable  for  parts  of  optical  instruments. 
Its  8p.gr.  is  2*85.  The  addition  of  aluminium 
to  tin  increases  its  hardness  and  tenacity.  The 
alloys  containing  5,  7,  and  0  p.c.  of  aluminium 
are  all  easUy  worked  and  soldered.  A  larger 
proportion  of  alumimum  is  liable  to  separate  out 
on  melting. 

Aluminium  combines  in  all  proportions  with 
cadmium,  forming  malleable  fusible  alloys. 

Small  quantities  of  silver  increase  the  nardness 
and  elasticity  and  lower  the  melting-point 
without  rend^ing  aluminium  brittle.  The  alloy 
containing  4  p.o.  silver  has  been  used  for  the 
beams  of  delicate  chemical  balances.  When  the 
addition  exceeds  5  or  6  p.c.  the  metal  becomes 
brittle ;  the  50  p.o.  alloy  is  as  hard  as  bronze, 
but  very  brlttie.  *  Tiers  argent '  consists  of  1 
part  silver  and  2  parts  aluminium ;  it  is  of 
considerable  hardness,  and  is  used  for  table- 
spoons, &c.  The  addition  of  5  p.c.  of  aluminium 
to  silver  renders  it  as  hard  as  standard  silver 
and  very  permanent. 

The  presence  of  aluminium  in  gold  consider- 
ably alters  its  properties.  The  addition  of  0*186 
p.c.  of  aluminium  to  pure  gold  increases  the 
tensile  strength  from  7  tons  to  8 '87  tons  per 
square  inch,  a  greater  increase  than  is  produced 
by  the  same  amount  of  any  other  metal  (Koberts- 
Austen,  Boy.  Soc.  Bep.  April,  1888;    Chem. 


News,  1888,  v.  57,  p.  133).  With  1  p.o.  alu- 
minium the  gold  has  the  colour  of  *  green  gold,* 
is  hard  but  easy  to  work ;  with  5  p.c.  aluminium 
it  is  white  and  extremely  brittle,  and  with  10  p.c. 
white,  brittle,  and  crystalline.  Aluminium  con- 
taining 10  p.c.  of  gold  is  white  and  haltl. 

The  malleabiUty  of  aluminium  is  not  much 
impaired  by  the  addition  of  gold,  silver,  or  tin, 
but  the  presence  of  excessive  amounts  of  iron, 
an4  especially  of  silicon,  is  very  injurious. 

The  alloys  of  aluminium  and  silicon  appear 
to  form  a  simple  eutectiferous  series,  the  sUicon 
branch  of  the  curve  exhibiting  no  singularity 
whatever  (Fraenkel,  Zeitsch.  anore.  Chenu 
1908,  58,  154).  These  results  have  Been  con- 
firmed by  Roberts  (Chem.  Soc.  Trans.  1914,  105, 
1383).  That  no  compound  is  formed  is  sup- 
ported by  the  fact  that  no  silicon  hydride  can 
be  detected  when  the  alloys  are  dissolved  in 
acids ;  the  silicon,  as  appears  from  a  microscopic 
study  of  the  structure  of  the  alloys,  crystcdlises 
in  plates  arranged  in  five-  or  six-rayed  stars. 

The  presence  of  silicon  renders  aluminium 
brittle  and  much  less  permanent. 

With  iron  the  alloys  are  of  especial  interest. 
The  presence  of  a  quantity  of  iron  is  very 
injurious ;  it  renders  the  aluminium  ciystalline, 
and  raises  the  melting-point.  The  alloy  con- 
taining 5  p.c.  of  iron  is  hard  and  brittle ;  with 
8  p.c.  the  alloy  crystallises  in  needles,  and  on 
heating  separates  into  a  more  liquid  alloy  con- 
taining but  little  iron  and  a  skeleton  very  rich 
in  that  metal.  Michel  (Annalen,  115,  102)  has 
prepared  an  alloy  which  crystallises  in  six-sided 
prisms,  corresponding  to  AlgFe.  A  beautifully 
crystalline  substance  having  the  composition 
Al^Fe  IB  often  found  in  the  neighbourhood  of 
the  cathode  of  a  reduction  furnace. 

The  valuable  properties  imparted  to  iron  and 
steel  by  the  presence  of  a  small  quantity  of 
aluminium  have  long  been  known;  Faraday 
(Quarterly  Joum.  Roy.  Inst.  1819,  290)  found 
from  0*013  to  0'069  p.c.  of  aluminium  in  certain 
samples  of  Bombay  wootz,  though  it  has  been 
shown  by  Henry  and  others  that  this  metal  is 
not  always  present.  About  the  same  time 
S.  B.  Rogers  showed  the  presence  of  alumimum 
in  some  of  the  best  quality  of  pig-iron  made  in 
South  Wales,  and  found  that  a  steel  to  which 
0'8  p.c.  of  aluminium  had  been  added  in  the  form 
of  aA  alloy  with  iron,  was  rendered  harder  and 
stronger  and  resembled  the  best  wootz  (Rogers, 
Metallun;y,  1858,  14).  A  superior  steel  was 
prepared  by  Sir  Charles  Knowles,  which  was 
stated.to  oweits  value  to  the  use  of  i!:ao2in  and  con- 
sequent introduction  of  aluminium  into  the  metal 
in  its  preparation  (Minins  Journal,  1859,  118). 

Messrs.  Cowles  Bros,  nave  exhibited  a  Sie- 
mens-Martin basic  steel  containing  0*2  p.o. 
aluminium,  which  welds  with  iron  and  shows  no 
mark  at  the  junction. 

The  addition  of  aluminium  to  iron  or  steel 
for  the  production  of  *  mitis  castings '  has  been 
patented  by  P.  Ostber^  (Engineering,  1886,  360). 
Iron  and  steel,  especiidly  at  temperatures  far 
above  the  melting-point,  absorb  considerable 
quantities  of  gas,  which  impairs  the  value  of  the 
castings.  The  addition  of  0*05  or  O'l  p.o.  of 
aluminium  to  the  fused  iron  or  steel  lowers  the 
mc 

and  consiaeraDiy 
metal  can  then  be  easily  cast. 


lelting-point,  prevents  the  absorption  of  gas, 
ad  considerably  increases  the  fluidity.    The 


168 


ALUMINIUM. 


yickd  and  aluminium  combine  with  incan- 
descence when  heated  together.  The  presence 
of  under  3  p.c.  of  nickel  lowers  the  melting-point 
and  increases  the  hardness  and  elasticity. 

Pure  aluminium  combines  with  mercury, 
although  not  readily,  when  the  metab  are 
heated  together  in  an  inert  gaa  such  as  carbonic 
anhydride.  The  two  metals  combine  rapidly  in 
presence  of  alkalis.  The  amalgam  may  also  be 
produced  by  electrolysis  of  mercuric  nitrate, 
using  a  negatxve  plate  of  aluminium  dipping  in 
mercury.  When  aluminium  is  rubbed  with 
wash  leather  impregnated  with  mercury,  com- 
bination occurs ;  the  surface  rapidly  oximses  and 
becomes  heated,  with  formation  of  concre- 
tions of  alumina  (Jehn  and  Hinze,  Ber.  7, 
1498). 

AUoys  of  bismuth  with  aluminium  are  hard 
and  brittle.  With  antimony  and  lead  aluminium 
does  not  unite,  idthough  traces  of  lead  are  fre- 
quently present  in  commercial  aluminium. 

Sodium  unites  readily  with  aluminium.  The 
last  traces  of  sodium  are  difficult  to  remove, 
especi^y,  it  is  said,  when  the  metal  has  been 
reduced  from  cryolite.  The  alloys  are  easilv 
attacked  by  moisture,  and  bum  in  the  air,  with 
oxidation  both  of  the  aluminium  and  sodium ; 
that  containing  2  p.c.  of  sodium  decomposes 
water  with  ease.  The  necessity  of  avoiding 
the  presence  of  sodium  in  the  preparation  of 
aluminium  is  therefore  obvious. 

Aluminium  also  unites  with  man^n^e  ;  with 
platinum  it  unites  easily,  forming  fusible  alloys. 
With  horon  aluminium  combines  in  varyinfi| 
proportions.  The  so-called  'adamantine*  and 
graphitic  '  boron  appear  to  be  borides  of  alumi- 
mum  (Hampe,  Annafen,  1876,  75 ;  and  Deville 
and  Wohler,  ibid.  1867,  268)  (v.  Bobon). 

Mallet  (Chem.  Soc.  Trans.  1876,  ii.  350)  has 
prepared  a  nitride  of  iduminium  in  small  crystals 
hara  enough  to  scratch  glass.  It  may  be 
obtained  in  colourless  hexagonal  needles  of  the 
composition  AIN  by  direct  union  of  its  elements 
at  820".  It  forms  ammonia  when  fused  with 
potassium  hydroxide,  or  by  heating  with  sul- 
phuric acid.  Alcohol  forms  triethylamine  at 
230°.  Fichter  and  Spen^el  (Zeitsch.  anoig. 
Chem.  1913,  82,  192).  It  dissociates  in  nitrogen 
at  atmospheric  pressure  at  about  1850**.  When 
heated  in  nitrogen  at  a  pressure  of  4*3  atmos.  it 
melts  at  2150''-2200''  (Wol£F,  Zeitsch.  anoig. 
Chem.  1914,  87,  120). 

For  further  information,  see  J.  W.  Richards, 
Aliimininm  and  its  Allovs,  London. 

Aluminium  oxide.  Alumina^  ALO,. 

Aluminium  forms  only  one  oxide,  Al|Os,  cor- 
responding to  and  isomorphous  with  the  ses- 
quioxides  of  iron  and  chromium. 

This  oxide  occurs  native,  colourless  as 
hyaline,  corundum;  or  coloured  by  metallic 
oxides,  as  ruby,  ^j>phire,  oriental  topaz,  &c.  (q.v.). 
Very  impure,  dark,  and  usually  associated  wiUi 
masnetite  and  hcematite,  it  occurs  in  lai^e 
boulders  in  many  districts,  and  is  used  as  a 
grinding  and  polishing  material  in  the  form  of 
etnery  (q.v,).  The  native  oxide  crystallises  in  the 
rhombohedrai  system;  in  hardness  it  comes 
next  to  the  diamond.  The  finely  coloured 
specimens  are  used  as  gems.  It  occurs  almost 
pure  in  considerable  quantities  in  the  Alleghanies 
m  Northern  (Georgia. 

It   may    be   prepared    by   the   ignition   of 


aluminium  foil  in  air  or  oxysen ;   the  oxide  so 
produced  is  fused  and  as  hard  as  corundum. 

Alundum  is  fused  alumina,  a  product  made 
up  into  electrical  furnace  cores,  crucibles,  bncks 
and  tubes  where  high  refractory  properties  are 
of  .value.  It  withstands  2000**,  and  has  a  linear 
expansion  of  0*0000078,  a  specific  heat  of  0'195  ; 
at  hi^h  temperatures  (over  1600**)  it  has  a  low 
electrical  resistance.  It  is,  however,  inapplic- 
able to  use  in  some  directions  owing  to  its 
porosity. 

Amorphous  alumina  may  be  produced  by 
ignition  of  the  precipitated  hydrate,  pure  alu- 
minium sulphate  or  ammonia  alum ;  in  either 
case  alumina  alone  is  left. 

It  is  white  and  soft,  but  becomes  lucrd  on 
strong  ignition.  According  to  H.  Rose  (Pogg, 
Ann.  74,  430)  the  sp.gr.  of  the  oxide  after 
heating  over  a  spirit-lamp  is  3*725  ;  its  density 
may  be  raised  to  4,  just  aoout  that  of  corundum 
by  heating  in  a  porcelain  furnace,  but  it  still 
remains  amorphous.  It  is  remarkable  that 
though  the  density  of  the  artificially  prepared 
alumma  is  nearly  4,  its  bulk  density  may  be  less 
than  one-fifth  of  this.  With  a  somewhat  lower 
density  the  bulk  density  is  higher,  but  is  still 
such  that  it  occupies  a  laiger  biUk  than  the 
same  weight  of  water. 

When  heated  by  the  oxyhydrogen  blow-pipe^ 
alumina  melts  at  2050^  and  crystallises ;  Uie 
addition  of  chromium  oxide  or  a  chromate 
imparts  a  ruby  colour  to  the  ciystalB.- 

Fremy  ana  Vcmeuil  (Compt.  rend.  1888, 
566)  have  prepared  artificial  rubies  by  heating 
to  redness  a  mixture  of  barium  fluoride  and 
alumina  containing  a  trace  of  potassium  dichro- 
mate.  The  heat  requires  careful  management. 
Fine  rubies  are  thus  formed  in  a  friable  matrix 
whii'h  may  be  separated  by  agitation  with  water. 
By  former  methods  the  matrix  was  hard  and 
difficult  to  remove  (Fremy  and  Feil,  Compt. 
rend.  1877,  1020,  and  1887,  737).  The  crysUls 
contain  no  barium,  easily  scratch  the  topaz,  and 
possess  the  form  and  properties  of  natural  rubies ; 
their  crystalline  form  has  been  determined  by 
Descloiseaux  (Compt  rend.  1888,  567).  By  the 
addition  of  a  Uttlo  cobalt  oxide  before  the  fusion, 
sapphires  may  be  produced. 

Alumina  is  soluble,  when  strongly  heated,  in 
boric  acid ;  the  latter  may  be  driven  otf  at  a 
very  high  temperature,  leaving  crystalline 
alumina.  By  the  addition  of  the  proper  oxide 
the  corresponding  spinels  may  m  produced, 
coloured  by  cobalt  oxide  (blue),  chromram  oxide 
(red),  iron  oxide  (black),  (EbeUnen,  Ann.  Chim. 
Phys.  3,  22,  211  and  33,  34).  Only  two  hydroxides 
of  aluminium  are  Imown,  viz. :  A],Os,U,0  and 
Als03,3H.O.  By  Graham's  method  an  aaueous 
solution  of  the  hydroxide  may  be  obtained. 

When  the  hydroxide  is  freshly  precipitated 
it  dissolves  readily  in  dilute  acids,  but  on 
standing,  or  after  filtration,  solution  is  more 
difficult,  and  is  best  achieved  by  a  mixture 
of  8  parts  of  sulphuric  acid  and  3  parts  of 
water.  When  heated,  the  hydroxide  loses  its 
water,  undergoing  a  contraction  of  about  30 
p.c,  in  bulk  as  it  passes  into  the  form  of  the 
anhvrlrous  oxide. 

When  boiled  with  water  containing  a  drop 
of  a  1  p.c.  solution  of  alizarin,  the  hydix>xide 
aspumc3  a  bright  red  colour,  not  removed  by  a 
weak  solution  of  acetic  acid. 


ALUMINIUM. 


169 


This  t:»t  easily  distinguishes  it  from  gelatin- 
ous silica.  Alnininiam  hydroxide  possesses  a 
powerful  affinity  for  many  organic  substances, 
and  enters  into  association  with  a  large  number 
of  colouring  matters,  precipitating  them  entirely 
as  lakes.  On  this  property  depends  the  use  .of 
alum  mordants  (red  Uquor,  &o.).  They  pre- 
cipitate the  hydroxide  upon  the  fibre  of  the 
goods  to  be  dyed,  and  this  constitutes  the 
mordani  or  fixing  agent  which  retains  the  colour. 

Sodium  almmnato  AIjOvSNa.O  or  Al.CNaO),. 
This  salt  is  now  prepared  on  a  large  scale,  both 
to  be  used  as  such  and  as  an  intermediate  pro- 
duct in  the  preparation  of  the  sulphate  and  other 
salts  of  aluminium. 

Its  formation  depends  upon  the  property 
possessed  by  alumina  of  acting  as  an  acid  in  pre- 
sence of  a  powerful  base. 

Its  preparation  from  bauxite  has  already 
been  described.  It  may  also  be  pioduccd  by 
passing  a  current  of  steam  through  a  heated 
mixture  of  bauxite  and  common  salt,  and  by 
strongly  heating  a  mixture  of  bauxite,  sodium 
nilpbate,  and  carbon,  but  in  the  latter  case  its 
porification  from  the  sodium  sulphide  simul- 
taneously produced  is  difficult.  It  is  also  formed 
in  the  preparation  of  soda  from  cryolite.  Accord- 
ing to  Thomsen's  method,  powdered  cryolite  b 
heated  to  redness  with  chalk,  forming  sodium 
nluminate  and  calcium  fluoride  : — 
AltF,-6NaF+6CaOO,=Al,(NaO),+6CaP,+6CO, 

The  mass  produced  is  lixiviated  with  water  and 
filtered.  Jra>m  this  aluminate  the  hydroxide  is 
precipitated  by  carbon  dioxide  with  formation 
of  sooium  carbonate  : — 

Al,(NaO)g+800,+3H,0=Al,(OH),+3N«,CO» 

The  hydroxide  is  usually  made  into  aluminium 
sulphate  by  solution  in  sulphuric  acid,  or  it  ii 
conyerted  mto  alum. 

An  entirely  different  process  has  been  intro- 
daced  by  Sauerwein.  The  &iely  powdered  cryolite 
is  boiled  with  milk  of  lime  forming  aluminate  as 
before: — 

Al,F,-6NaF+6CaO=Al,(NaO),+6CaF^ 

For  the  conyersion  of  the  aluminate  into  oxide 
Sauerwein  applies  a  peculiar  property  possessed 
by  that  salt,  which  shows  the  readiness  with 
which  alumina  loses  its  acid  properties  and  a^ain 
becomes  basic.  Sodium  aluminate,  when  mixed 
in  equivalent  proportions  with  any  haloid  salt  of 
aJominium,  isaeoomposed ;  the  sodium  combines 
with  the  halogen,  while  the  whole  of  the  alumi- 
nium is  precipitated  as  hydroxido.  On  the  large 
■cale  the  haloid  salt  used  is  cryolite.  The  finely 
powdered  mineral  is  stirred  into  the  clear  liquid 
m>m  the  previous  operation,  and  the  alumina 
precipitated  as  hydroxide : — 

Alt(NaO),-fAl^,-6NaF-f6H,0 

=2Al,(OH),+  12NaF. 

Sodium  aluminate  Is  a  white,  infusible, 
amorphous  solid,  easily  soluble  in  both  cold  and 
hot  water.  The  concentrated  solution  rapidly 
deposits  alumina,  leaving  in  solution  a  basic 
adnroinate,  which  on  evaporation  is  obtained  as 
a  fusible  and  hygroscopic  mass.  The  addition 
of  any  acid  at  once  decomposes  it  with  precipita- 
tion of  alumina.  This  alumina  is  pure  and  free 
from  alkali,  which  is  never  the  case  when  alkaline 
precipitants  have  been  used.  It  may  be  employed 
as  a  mordant  in  dyeing  and  calico-printing,  in 


an  acid  and  not.  as  in  the  case  of  alum,  an 
alkaline  bath.  For  the  production  of  lakes  the 
colouring  matter  is  mixed  with  the  aluminate 
solution  and  precipitated  by  the  addition  of  sul- 
phuric acid.  According  to  Morin  these  lakes 
are  richer  than  those  obtained  from  alum  and  are 
produced  at  about  one  half  the  cost. 

Potasslam  aluminate  A1,0,-3K,0  or  Al,(KO)« 
is  obtained  in  hard  glistening  crystals  when 
alumina  is  fused  with  potash,  the  mass  boiled 
in  water  and  the  solution  evaporated  in  vacud. 

AlomUiliim  ehloride  A1,G1|.  This  compound 
was  first  prepared  in  1824  by  Oersted,  by  passins 
chlorine  over  a  mixture  of  alumina  and  charcoal 
heated  to  redness.  The  method  and  apparatus 
resemble  that  used  in  the  preparation  of  the 
double  chloride,  omitting  the  sodium  chloride. 

According  to  P.  Curie  (Chem.  News,  28,  307) 
it  may  be  easily  prepared  as  follows : — Anhy- 
drous alumina,  or,  loss  satisfactorily,  day,  is 
strongly  heated  in  a  tube  and  subjected  to  a 
current  of  hydrochloric  acid  impregnated  with 
carbon  disulphide  by  bubbling  t&ough  that 
liquid.  Aluminium  sulphide  appears  to  be 
formed  and  at  once  decomposed  by  the  hydro- 
chloric acid,  yielding  aluminium  chloride  And 
sulphuretted  hydrogen.  The  condensed  chloride 
may  be  freed  from  sulphur  by  distillation  with 
iron  filhigs. 

A  solution  of  the  chloride  may  be  obtained 
by  dissolving  the  hydroxide  in  hy<kochlorio  acid. 

The  pure  anhydrous  chloride  is  a  white,  waxy, 
crystalline  solid  ;  in  presence  of  a  trace  of  iron 
it  becomes  yellowish.  On  heating,  it  volatilises 
mthout  fusion.  If  large  pieces  be  quickly  heated 
they  fuse  and  boil  at  180*  to  185»  (Liebig).  It 
is  very  hygroscopic,  and  evolves  hydrochloric 
acid  on  exposure  to  the  air ;  is  easily  soluble  in 
water :  soluble  in  alcohol  and  ether.  When 
deposited  from  a  solution  in  hydrochloric  acid, 
it  forms  crystals  of  the  formula  A1,G1|,12H,0. 

It  absorbs  ammonia  and  combines  with 
many  metallic  chlorides,  forming  double  chlor- 
ides, the  most  important  being  that  with  sodium. 
Aluminium  chloride  has  been  recommended  by 
Filsinger  (Chem.  Zentr.  10, 1270)  for  the  preserva- 
tion of  wood,  and  by  Saget  (Chem.  News.  46, 113) 
and  others  (J.  Soc.  Chem.  Ind.  1882,  185  and 
230)  for  the  production  of  a  dischar^  on  indigo 
blue.  An  impure  chloride  oontainmg  calcium 
and  sodium  salts  is  stated  to  be  largely  used  as  a 
disinfectant  under  the  name  *  Chloralum.' 

Double  ehloride  of  atnmlnliim  and  sodium 
Al,Clg,2NaCl.  This  compound  may  be  pro- 
duced by  fusing  together  the  proper  proportions 
of  aluminium  ana  sodium  chlorides.  It  is  a 
colourless  ciystalline  solid,  melting  at  185* 
(Deville)  and  volatilising  at  a  red  heat.  It 
is  slightly  hygroscopic,  but  much  less  so  than 
aluminium  chloride ;  it  is  also  more  stable 
and  more  satisfactory  in  use  than  that  sub- 
stance, and  gives  up  nearly  the  whole  of  its 
aluminium  when  reduced  by  sodium. 

Aluminium  bromide  Al,Br«  is  most  readily 
prepared  by  the  action  of  bromine  on  metallic 
aluminium.  The  action  is  violent,  and  the  metal 
should  only  be  added  gradually.  A  lump  of 
aluminium  weighing  twenty  grams  becomes 
strongly  heated  and  even  fused  on  being  placed 
in  cold  bromine  (Mallet,  Phil.  Trans.  171,  I0I8). 

It  may  also  be  prepared  by  the  action  of 
bromine  on  a  strongly  heated  mixture  of  alumina 


170 


ALUMINIUM. 


and  carbon,  and,  in  solution,  by  diwolving  the 
hydroxide  in  hydrobromio  acid.  It  oryBtalliaes  in 
colonrlefls  shining  lanunn,  which  melt  at  03^ 
(DeYille  and  Tiooet)  and  boU  at  263*3^  (at  747 
mm.)  (Mallet). 

iSie  the  chloride,  it  forma  a  doable  bromide, 
AlaBrg,2KBr. 

Alimlnlom  Iodide  Al  J,  may  be  prepaied  by 
heating  alnminium  with  iodine  in  a  closed  tabe. 
It  mefts  at  about  186"*  (Weber)  and  boils  at 
350*  (DeviUe  and  Troost) ;  its  vapour  is  com- 
bustible. It  dissolves  in  water,  alcohol,  and 
carbon  disulphide. 

Aluminium  flnoride  Al^F^  may  be  nrepared 
.  by  tlie  action  of  gaseous  sihcon  fluoride,  or  of 
hydrofluoric  acid  upon  aluminium.  It  forms 
transparent  rhombohedra,  volatile  at  a  red  heat, 
insoluble  in  water  and  unacted  upon  by  acids. 
In  solution  in  hydrofluoric  acid,  it  appears  to 
form  the  compound  Al,Fg'6HF,  the  acid  cor- 
responding to  the  double  fluoride  of  aluminium 
ana  sodium. 

K  Cryolite  Al,F,*6NaF.  This  important  com- 
una  may  be  prepared  artificially,  and  attempts 
ve  been  made  to  produce  it  as  a  substitute  for 
the  natural  cryobte,  it  being  claimed  that 
the  artificial  cryolite  possesses  the  advantage 
of  being  lighter  and  meltins  at  a  lower  tem- 
perature (J.  Soa  CSiem.  Ind.  1890,  945).  In 
recent  years,  however,  artificial  cryolite  has  been 
put  on  the  market  which  presents  no  essential 
difference  either  in  composition  or  properties 
from  natural  orjrolite.  Natural  ory olite  occurs  in 
ouantity  only  m  one  locality,  in  a  laige  vein  in 
tne  gneiss  at  Ivigtut  in  Greenland.  Qreenland 
cryoute  has  the  following  composition :  Al  13*2, 
Na  32*7,  F  54*2,  and  small  quantities  of  silica. 
The  melting-point  of  mixtures  of  cryolite  and 
alumina  is  said  to  be — 


Cryolite 
With  3  p.c.  A1,0, 
6  p.c. 
10  p.c. 
16  p.c. 
20p.c. 


$» 


tt 


tf 


*» 


1000» 
974* 
9fl0*» 
980* 
994*» 
1016* 


(Chem.  Soo.  Abet.  1907,  460 ;  also  Ghem.  Soc. 
Abst.  1913,  608). 

It  is  a  semi-transparent,  white,  crystalline, 
brittle  solid,  which  melts  at  the  ed^es  in  a  candle 
flame.  Its  hardness  is  2*5  to  3  ;  its  sp.gr.  2*95, 
but  2*21  in  the  fused  state.  When  impure  it  is 
frequently  yellowish-red  or  even  black  (v. 
Cbyolite). 

Cryolite  is  used  as  a  flux  in  the  manufacture 
of  aluminium ;  formerly  for  making  salts  of 
sodium  and  aluminium ;  and  for  the  manufac- 
ture of  an  opaque,  porcelain-like  glass/  It  is 
also  used  for  enamelling  pans  and  as  a  glaze  for 
pots  as  replacing  lead  glaze.  {See  further, 
Benzon,  Hoffmann's  Ber.  £ntw.  Chem.  Ind. 
[1]  660).) 

Aluminium  sulphide  A1,S„  may  be  prepared 
by  strongly  heating  a  mixture  of  aluminium 
and  sulphur,  or  by  heating  alumina  to  bright 
redness  in  the  vapour  of  carbon  disulphide. 
It  forms  a  yellow,  ^las^  mass,  which  fuses 
at  1100%  and  burns  m  air  with  production  of 
alumina  and  sulphur  dioxide.  It  may  be 
purified  bv  sublimation  in  a  vacuum  at  1100°- 
1260'*,  and  then  forms  white  needles  resembling 
asbestos  of  sp.gr.  202  ISVIS"*  (BUtz  and  Cas- 


pari,  Zeitach.  anors.  C9iem.  1911,  71,  182).  It 
IS  readily  hydrolysed  by  water.  Houdard 
(Compt.  rend.  1907,  801)  found  that  by  heating 
aluminium  turnings  and  sulphides  of  manganese 
iron  and  chromium  in  a  carbon  boat,  sulphides 
related  to  the  spinels  are  formed,  of  which  he 
prepared 

MnS,Al^„  FeS,Al,S„  Or6,Al,S, 

Aluminium  earbide  AIJC^  ma^  be  obtained 
by  the  action  of  carbon  or  the  oxides  of  carbon 
on  alumina  at  very  high  temperatures,  and  often 
occurs  in  small  quantity  contaminated  with 
nitride  in  the  neighbourhood  of  the  cathode 
of  aluminium  reduction  furnaces  in  the  form 
of  a  yellow  powder;  it  is  formed  when  a 
mixture  of  alumina  and  carbon  is  submitted 
to  a  current  of  300  amperes  at  66  volts. 
It  possesses  the  remarkable  property  of  being 
stable  at  hi^h  temperatures,  and  yet  undergoing 
decomposition  at  a  dull  red  heat.  It  reacts, 
though  somewhat  slowly,  with  water  or  dilute 
acids  with  the  production  of  methane.  The 
formation  of  carbide  and  ultimately  its  decom- 
position has  been  proposed  as  a  means  of  pre- 
paring alumina  from  clay  or  other  crude  matenals. 
Friiig  (Chem.  Soc.  Trans.  1906,  1630)  found 
that  up  to  1400®  C.  the  carbide  acts  as  a  reducing 
agent  on  metallic  oxides, 

Al4C,+ 12MO=2Al,0,+3CO,+ 12M 

but  at  higher  temperatures  alloys  of  aluminium 
and  the  metal  axe  produced,  omy  carbon  being 
oxidised, 

Al4C,+3CuO=Al4Cu,+3CO 

owing  to  the  fact  that  alumina  can  be  reduced 
by  carbon  at  very  hish  temperatures ;  at  lower 
temperatures  the  aluminium  is  oxidised  by 
carbonic  oxide  as  observed  by  Moissan, 

6Al+3CO=Al4C,-fAl,0, 

the  reaction  being  reversed  at  the  higher  tem- 
peratures. 

Ahmiliitum  fulphate  A1,04(S0,)„18H,0  or 
Ala(SOJ„18HaO.  Aluminium  sulphate  ooours 
naturally  in  considerable  quantities.  As  the 
hydrated  salt  of  the  above  composition,  it 
forms  the  chief  constituent  of  the  mineral 
alunoaen,  haiolrichite,  feather  alum,  or  hair  sail. 
which  is  found  in  volcanic  districts,  at  Bilin  in 
Bohemia,  Ck>piapo  in  Chile,  &o.  It  also  occord 
in  pyritio  shale.  A  sample  of  feather  alum  from 
Fnesdorf,  Bonn,  was  found  by  Rose  to  contain 
A1,0,  14-9  p.c.,  SO,  37-4  p.c.,  FeO  2-6  p.c., 
H.O  46*2  p.c,  with  traces  of  K,  Na,  Big,  and 
SiOf 

Aluminite  or  websUriU,  a  hydrated  basic  salt 
of  the  composition  Alt03SO„9H,0,  has  been 
found  at  Auteuil,  Halle,  Muhlhausen,  &c. 

In  combination  with  potassium  sulphate,  the 
basic  salt  occurs  also  in  aluniie,  alumstonef  or 
alum  rock  K2S04,3A1,0,(S0,),6U,0,  a  mineral 
which  is  found  in  lax^  Quantities  at  La  Tolfa 
near  CSivita  Vecchia,  m  Hungary,  at  Puy-de- 
Sanoy  and  Madriat  in  Anver$!ne,  New  ooatli 
Wales,  Kyoquot  Sound  (Canada),  and  in  many 
other  localities.  Tt  usually  occurs  in  fibrous 
compact  masses  in  trachyte,  of  colour  varying 
from  white  to  red  or  brown,  being  produced  by 
the  action  of  sulphurous  gases  upon  trachytfo 
rocks  rich  in  felspar. 

The  alunite  from  La  Tolfa  contains  from 


ALUMINIUM. 


171 


35  p.o.  to  17*5  p.o.  alamina;  the  average 
compoeition  of  the  mineral  is  Al^O.  27*6  p.o., 
80,  29-74  p.c.,  K,0  7-55  p.c.,  Fe,0,  1-2  p.c, 
SiO,  22-7  p.c,  H,0  11-2  p.c. 

Alimuniam  sulphate  may  be  produced  by 
dissolving  either  the  hydrated  oxide  or  the 
silicate  in  sulphuric  acid.  Of  the  raw  materials 
available  for  its  manufacture,  the  two  which 
axe  of  the  greatest  importance  at  the  present 
time  are  china  day  (kaolin)  and  bauxite.  China 
clay  is  a  very  pure  varie^  of  clay,  resulting 
from  the  natural  decomposition  of  felspar,  and 
approximating  in  composition  to  the  formula 
id,0„2SiO^&,0.  It  is  of  comparatively  rare 
occurrence,  bei|^  found  chiefly  m  Devon  and 
Oomwall  in  ^gland;  at  St.  Yrieix  near 
limoffosy  and  in  the  departments  of  Allier, 
Pay-oe-Bome,  and  Brittany,  in  France;  at 
Seuitz  in  Saxony ;  and  at  Nassau  in  Bavaria. 

Bauxite  is  an  impure  aluminium  hydroxide 
A1,0„2H,09  oontainmg  widely  varying  quan- 
tities of  silica  and  feme  oxide.  It  is  K>und  in 
Ireland,  in  the  south  of  France,  and  in  Austria, 
Calabria,  Sen^^^  Suy,  (v.  Bauxite). 

llie  composition  of  typical  commercial  grades 
of  the  two  mxnends  is  given  in  the  folfowing 
table,  the  analyses  having  been  made  on 
material  dried  at' 100^: — 


China  clay 

Bauxite 

Bouree 

BtStephen's 

St.Aii8teU 

Antrim 

France 

TiO, 

K,0+Na,0 

HaO(oomb.) 

40-15 

0-35 

45-00 

0*80 
13-70 

4110 

0-20 

46-20 

trace 
12-50 

41-08 
3-21 

}33-17 
22-54 

64-18 
3-47 

18-96 
13-39 

Total 

100-00 

100-00 

100-00 

100-00 

Production  of  aluminium  tulphaU  from  china 
day, — At  the  present  time  the  manufacture  of 
aluminium  sulphate  from  china  clay  is  carried 
out  on  an  extensive  scale  by  a  process  based 
upon  the  original  patent  of  Pochin  (Pktt.  1855, 
14656).  The  clay,  containins  about  40  p.c. 
alumina,  is  obtained  from  Cornwall,  ana  is 
selected  as  free  as  possible  from  grit  and  oxide 
of  iron.  It  is  reduced  by  milling  and  sifting 
to  the  finest  possible  state  of  division,  and  after 
a  preliminary  drying  by  exposure  to  a  warm 
atmosphere,  is  calcined  at  a  dull-red  heat  in  a 
reverberatory  furnace.  The  furnace  is  provided 
with  three  working  doors,  the  material  being 
introduced  by  the  door  which  is  most  remote 
^from  the  firegrate,  and  gradually  raked  forward 
until  it  reaches  the  hottest  part  of  the  hearth. 
During  the  calcination  the  clay  su£Fers  a  loss  in 
weight  amounting  to  from  20  to  25  p.c. ,  due  to  the 
expulsion  of  the  whole  of  the  moisture  present 
(10  to  15  p.c.)  and  of  the  greater  part  of  the 
water  of  hydration. 

The  calcined  clay,  which  still  contoins  about 
3  p.0.  of  water,  is  transferred  by  means  of  iron 
tubs  to  a  lead-lined  wooden  vat  conteining 
the  requirite  quantity  of  sulphuric  acid,  heated 
to  a  temperature  of  85*,  and  having  a  strength 


at  this  temperature  of  96^  Tw.  A  vigorous 
reaction  immediately  tekes  place,  and  after  the 
lapse  of  15  minutes,  during  which  period  the 
contento  of  the  vat  are  kept  well  agiteted,  the 
product  is  run  into  lead-lined  wooden  waggons 
(with  removable  sides),  in  which  the  reaction 
continues  for  a  considerable  time  and  the  pasty 
mass  gradually  solidifies.  Finally  the  solid 
block  is  brought  under  a  heavy  mechanical  knife, 
and  by  a  combined  cutting  and  crushing  action 
is  reduced  to  the  stete  of  a  coarse  powder. 

The  product,  which  is  brought  on  the  market 
under  the  name  of  *alum  cake,'  contoins  the 
whole  of  the  silica,  iron,  and  other  impurities 

E resent  in  the  clay,  ite  average  composition 
eing:  A1,0,  (soluble)  12-25  to  13-0  p.c., 
Fe,0,  012  to  0-22  p.c. ;  combined  SO,  29-5  to 
31-8  p.c.,  free  SO,  0-4  to  1-0  p.a;  insoluble 
matter  20-0  to  26-5  p.c. 

About  60  p.c.  of  the  alumina  present  in  the 
china  day  is  converted  into  sulphate. 

The  commercial  *  white  sulphate  of  alumina  * 
is  prepared  from  alum  cake  in  the  foUowinjg 
manner :  The  coarsely  crushed  alum  cake  is 
lixiviated  with  water  (or  with  weak  liquors  from 
previous  extractions)  in  lead-lined  vate  heated  by 
live  steam ;  after  settling,  the  clear  solution  is 
decanted  by  means  of  a  hinged  pipe,  and  run 
into  lead-lined  evaporators,  heated  by  steam 
coils,  where  it  is  concentrated  to  a  strength  of 
112'Tw.  at  the  boiling-point  (about  115*). 
The  sjnrupy  liquid  is  then  run  into  a  series  of 
shaUow  tiled  troughs,  where  it  solidifies  on 
cooline.  Before  solidification  occurs,  a  number 
of  leaden  partitions  are  inserted  in  the  troughs, 
and  the  product  is  thus  obteined  in  the  form  of 
rectengiUar  blocks  of  uniform  size  (24"  X  0"  X  6"). 
*  White  sulphate  of  alumina,'  prepared  by  the 
above  process,  contains  on  an  average  about 
14  p.c.  of  alumina  and  0-25  p.c.  of  ferric  oxide, 
ana  is  practically  free  from  insoluble  matter. 
Another  grade  of  tiie  material  is  prepared 
conteining  17*5  p.0.  alumina. 

Preparation  of  aluminium  sulphate  from 
bauxite. — The  substitution  of  bauxite  for  china 
olay  in  the  manufacture  of  aluminium  sulphate 
was  proposed  by  Lechatelier  in  1858,  and  ite 
ti^eatment  forms  the  subject-matter  of  numerous 
patente.  Bauxite  has  the  advantege  over  china 
clay  that  it  is  more  readily  soluble  in  acid,  and 
neeos  no  preliminary  calcination,  the  chief 
drawback  to  ite  use  being  the  presence  of  a 
comparatively  large  amount  of  iron. 

The  treatment  of  bauxite  for  the  preparation 
of  *  alumino-ferric  cake,'  as  patented  by  Messrs. 
P.  and  F.  M.  Spence  (1875),  is  as  follows  :— The 
mineral  is  digested  with  dilute  sulphuric  acid 
with  the  aid  of  steam  until  the  acid  is  neu- 
tralised ;  the  insoluble  matter  allowed  to  sub- 
side, and  the  solution  evaporated  to  116^w. 
and  run  into  shallow-partitioned  lead  coolers. 
It  there  solidifies,  and  is  removed  in  blocks 
18  or  20  inches  square,  each  weighing  about 
1  cwt.  It  is  yellowiBh-ereen  in  colour,  con- 
tains much  alumina,  and  a  small  proportion 
of  iron  and  free  acid.  It  is  used  in  the  prepa- 
ration of  all  but  the  finest  papers,  in  the  pre- 
cipitetion  of  sewage  and  refuse  liquids,  ana  in 
the  clarification  and  decolourisation  of  water 
supplies.  The  following  analysis  shows  ite 
general  composition  :  ^,0,  14-26  p.a  (corre- 
sponding to  A1,0,3S0, 47 -61  p.c.),rea03  0-28  p.c.. 


172 


ALUMINIUM. 


FeO  0-32  p.p.»  SO,  (combined)  35*30  p.c.,  SO, 
(free)  0*46  p.o.     InjBoluble  O'OC  p.o. 

The  commeroia]  sulphate  of  alumina  which 
is  sold  nnder  the  names  of  *  concentrated  alum ' 
and  '  alferite,*  resembles  alumino-ferric  in  com- 
positioD,  and  is  prepared  by  a  similar  process. 
The  following  details  concerning  its  manu- 
facture will  serve  to  exemplify  modem  prac- 
tice. 

As  raw  material,  it  is  usual  to  employ  a  mix* 
ture  of  Irish  and  French  bauxites,  reduced  by 
means  of  disintegrators  to  the  state  of  a  coarse 
powder.  The  powdered  mineral  is  conveyed  by 
means  of  an  elevator  to  a  lead-lined  vat  contain- 
ing sulphuric  acid,  heated  to  its  boiling-point 
(about  125*),  and  having  a  strength,  at  this 
temperature,  of  70^w.  The  mixture  of  acid 
and  bauxite  is  boiled  vigorously  for  6  hours, 
after  which  it  is  diluted  with  weak  liquors  to 
70^w.  (measured  at  the  boiling-point)  and 
allowed  to  settle.  The  clear  liquor  is  decanted 
and  evaporated  in  lead-lined  vessels  until  its 
density  reaches  112^w.  (boiling).  It  is  then 
run  into  partitioned  coolers  where  it  soUdifies, 
forming  blocks  or  slabs,  containing  on  an  average 
13*8  p.c.  alumina,  0*7  p.o.  ferric  oxide,  and  0*1 
p.c.  insoluble  mattw. 

If  French  bauxite  be  used  alone  in  the  above 
process,  great  difficulty  is  experienced  in  the 
clarification  of  the  liquor;  with  a  mixture  of 
Irish  and  French  bauxites,  however,  rapid 
settling  occurs,  and  a  perfectly  clear  liquor  is 
readily  obtained.  It  is  of  importance  also,  in 
this  connection,  that  the  liquor  should  retain  a 
small  amount  of  free  acid,  as  the  fully  neutralised 
solution  settles  very  slowly. 

Sulphate  of  alumina  prepared  by  *  an  v  of 
the  above  processes  always  contains  appreciable 
quantities  of  iron,  and  the  removal  of  this 
impurity  is  a  problem  of  considerable  impor- 
tance, and  one  which  has  received  the  attention 
of  many  chemists.  Numerous  processes  have 
been  devised  for  the  purpose,  but  it  is  doubt- 
ful if  any  of  these  is  satisfactory  in  works' 
practice. 

Newlands  (Eng.  Pat.  1880,  5287)  evaporates 
a  crude  solution  of  the  sulphate  to  a  density  of 
67'^w.  (at  200*F.)  and  cools  for  twenty-four 
hours  in  leaden  tanks. 

About  60  p.c.  of  the  sulphate  thus  crjrstallises 
out.  The  liquid  is  drained  off,  and  the  residue 
pumped  or  forced  into  lead-lined  filter  presses, 
the  plates  of  which  are  covered  with  tiiick  felt, 
and  separated  by  metal  rings.  Here  it  is  sub- 
jected to  a  pressure  of  about  200  lbs.  to  the 
square  inch.  The  hard  cake  so  produced 
contains  about  67  p.c.  of  the  total  aluminium 
sulphate,  and  0*05  to  0*1  p.c.  of  iron.  The 
mother  liquor,  evaporated  and  similarlv  treated, 
yields  a  second  and  third  crop  of  crystals 
containing  increasing  quantities  of  iron. 

Chadwick  and  Synaston  have  patented  a 
method  for  the  removal  of  iron  from  bauxite 
before  converting  the  latter  into  aluminium 
sulphate.  The  powdered  mineral  is  mixed  to  a 
thick  cream  with  water,  and  treated  with  5  to 
10  p.c.  of  oxalic  acid  and  sufficient  hydrochloric 
acid  to  prevent  the  formation  of  insoluble 
oxalates.  After  seven  to  ten  days  the  mass  is 
washed,  and  a  large  proportion  of  the  iron 
(together  with  some  of  the  alumina)  is  thus 
removed  as  oxalate. 


Condy,  in  1877«  proposed  the  reduction  (A 
the  iron  b^  reducing  agents,  or  its  conversion 
into  sulphide  by  smphuretted  hjrdroffen,  and 
the  removal  of  the  metal  or  sulpmde  by  dilute 
acid.  The  proportion  of  iron  may  thus  be  re- 
duced to  one-third. 

Weismann  suggested  the  precipitation  of 
the  iron  from  aluminium  sulphate  liquors  by 
means  of  potassium  ferrocyanide.  The  method 
is  by  no  means  satisfactoiy,  as  the  precipitate 
contains  much  alumina  and  subndes  very 
slowly. 

Kjmaston  precipitates  the  bulk  of  the  iron 
as  ferric  arsenite,  removing  the  last  portions 
with  calcium  ferrocyanide,  followed  oy  the 
addition  of  copper  or  zinc  sulphate. 

According  to  Fahlbeig  and  Semper  (Eng. 
Pat.  1881,  5579),  both  ferrous  and  ferric  salts 
may  be  precipitated  from  aluminium  sulphate 
by  agitation  in  the  cold  for  about  thirty  minutes 
with  lead  peroxide,  ferrous  salts  being  first 
oxidised  ana  then  precipitated.  No  lead  passes 
into  solution  unless  chlorides  be  present.  The 
composition  of  the  precipitate  is  not  known,  but 
the  peroxide  may  be  regenerated  by  digestion  in 
cold  nitric  acid.  P.  and  F.  M.  Spence  (Eng.  Pat. 
1882,  3835)  use  manganese  oioxide  for  the 
same  purpose.  In  presence  of  .reducing  agents 
such  as  ferrous  salts,  fta,  manganese  passes 
into  solution,  and  requires  to  be  reprecipitated 
by  addition  of  chlorine  or  a  hypochlorite. 

The  use  of  metantimonic  acid  and  meta- 
stannic  acid  (Hood  and  Salamon)  has  also  been 
proposed  for  the  precipitation  of  iron.  The  iron 
IS  first  oxidised  by  the  addition  of  bleaching 
powder,  and  the  liquid  is  neutralised  with  chalk 
and  agitated  with  the  precipitant.  Both  sub- 
stances may  be  regenerated  by  digesting  the 
prccipilnto  with  sulphuric  add. 

According  to  H.  Spence,  W.  B.  Llewellyn, 
and  P.  Spence  and  Sons  (Eng.  Pats.  23036, 1904 ; 
3805,  1912  ;  9148,  1914),  the  crude  liquor,  which 
must  be  basic  and  have  all  the  iron  in  the  ferric 
state,  is  treated  with  potassium  sulphate  and 
agitated  for  several  hours  at  from  60^  to  80"* 
until  most  of  the  iron  is  precipitated  as  insoluble 
basic  ferric  sulphate.  J.  Boulton  (Eng.  Pat. 
20227,  1914)  proposes  to  neutralise  the  free  acid 
in  and  remove  iron  and  other  impurities  from 
crude  aluminium  sulphate  by  immersing  in  the 
liquor  a  framework  of  magnetised  steel  wire 
with  cross  wires  of  copper  holding  zinc  rods  in 
suspension.  The  process  is  carried  out  for  six 
hours  at  38''. 

(For  further  information  regarding  these  pro- 
cesses, see  Beveridge,  J.  Soc.  Chem.  Ind.  1886, 
16-22;  B.  E.  R.  Newlands,  ibid.  1882,  124; 
Kynaston,  Chem.  News,  40,  191  and  202.) 

Most  of  the  above-mentioned  processes  for 
the  purification  of  aluminium  sulphate  from  iron 
possess  little  or  no  commercial  significance  at 
the  present  time.  *  Pure  aluminium  sulphate  * 
is  prepared  directly  from  pure  alumina,  wnich  is 
obtained  from  French  red  bauxite  by  the 
*  alkali  fusion '  process.  The  bauxite,  after  & 
preliminary  roasting,  is  reduced  to  a  fine  powder, 
and  mixed  with  s^a  ash  in  such  proportions 
that  for  every  molecule  of  Al^O,  present  there 
are  1  to  1*5  molecules  of  Na.O.  The  mixture 
is  strongly  heated  in  a  reveroeratory  furnace, 
with  frequent  stirring,  for  a  period  of  five  hours. 
Carbon   dioxide   is   evolved   and   the  alumina 


ALUMINIUM. 


173 


and  fenio  oxide  are  converted  into  sodium 
aluminate  and  sodium  feirite  respectively. 
The  mass  is  lixiviated  by  saccesaive  ei^ractions, 
first  with  weak  liquor  from  previous  batches, 
and  finally  with  pure  water.  The  sodium 
aluminate  dissolves  as  such,  whilst  the  sodium 
ferrite  is  decomposed,  forming  insoluble  ferric 
oxide  which  remains  in  the  exhausted  residue, 
and  caustic  soda  which  passes  into  solution. 
The  ckun  liquor  is  run  into  a  boiler  and  saturated 
with  carbon  dioxide  produced  by  the  combus- 
tion of  coke  or  by  the  decomposition  of  limestone. 
During  the  passage  of  the  gas  the  contents  of 
the  boilerare  neat^  to  70°  C.  and  kept  thoroughly 
stirred  by  means  of  an  agitator.  When  the 
precipitation  of  the  alumina  is  complete,  the 
uquia  is  allowed  to  settle  and  the  clear  liquor 
decanted  and  concentrated  for  the  recovery  of 
the  dissolved  sodium  carbonate,  whilst  the 
alumina  is  drained  in  a  hydro-extractor. 

A  cheaper  process  for  obtaining  the  alumina 
from  the  sodium  aluminate  has  been  devised  by 
Bayer,  as  already  described. 

The  alumina  prepared  by  either  of  the  above 
proceooce  yields  by  treatment  with  sulphuric 
add,  a  very  pure  quality  of  aluminium  sulphate. 
Two  nadee  of  the  latter  are  commonly  prepared 
for  the  Enfflish  market — the  one,  sola  in  the 
form  of  slabs  or  blocks,  contains  14*0  p.c.  of 
alumina  and  0*0025  p.c.  of  ferric  oxide,  the 
other,  sold  in  powder,  contains  17*0-18*0  p.c. 
of  sJumina  and  0*0040  p.c.  of  ferric  oxide. 

Aluminium  sulphate  crystaUises  with  diffi- 
culty in  thin,  six-sided  nacreous  plates,  con- 
taining 18  molecules  of  water  ana  having  a 
density  of  1*6913  at  17**  C.  (Dewar).  The 
following  table  of  solubilities  is  ffiven  by  Poggiale 
(Ann.  Chim.  Phys.  [3]  8,  467)  for  the  crystalline 
and  anhydrous  salts : — 


Temp.  °C, 


0 
10 
20 
30 
40 
60 
60 
70 
80 
90 
100 


Sdnbtlity  in  100  parts  of  water 


Al^(S04)s 


Al2(S04)s,18HsO 


31*3 
33-5 
361 
40-4 
46-7 
62-1 
591 
66-2 
731 
80-8 
891 


86*8 
96*8 
107*3 
127*6 
167*6 
201*4 
262-6 
348-2 
467-3 
678-8 
1132*0 


llie  addition  of  alcohol,  in  which  aluminium 
mll^ate  is  afanoet  insoluble,  to  aqueous  solutions 
of  aluminium  sulphate,  faoilitateiB  the  orystaili- 
aation  of  the  salt  (Persoz). 

When  heated,  aluminium  sulphate  melts  in 
its  water  of  crystallisation,  swells  up,  and  gradu- 
ally forms  a  white  porous  mass  of  tne  anhydrous 
mdphate,  which  omv  dissolves  slowly  in  water. 
At  a  red  heat  oxides  of  sulphur  are  expelled 
and  a  residue  of  pure  alumina  remains. 

Aluminium  sulphate  combines  readily  with 
the  sulphates  of  the  alkali  metals,  forming 
ciTstallme  double  sulphates,  known  as  alums, 
wnich  are,  as  a  rule,  considerably  less  soluble 
than  aluminium  sulphate  itself.    According  to 


Reuss  (Ber.  17,  2888),  the  addition  of  1  p.c.  of 
potassium  sulphate  to  a  solution  containing 
7  p.c.  or  upwards  of  aluminium  sulphate,  at 
once  produces  a  crystalline  precipitate  of  alum. 

The  general  industrial  uses  of  aluminium 
sulphate  are  the  same  as  those  of  ordinary 
alum.  It  is  largely  used  in  paper-making,  water 
purification,  and  in  the  preparation  of  red  liquor 
as  a  mordant.  The  coarser  preparations  are 
em^oyed  for  the  precipitation  of  sewage. 

Karl  Reuss  (Ber.  17,  2888)  gives  the  densitv 
of  solutions  of  pure  anhydrous  aluminium  sul- 
phate as  follows : — 


Density  at 
16^C. 


1*017 

1-027 

1-037 

1-047 

1  -0569 

1-0670 

1*0768 

1-0870 

1-0968 

11071 

1.1171 

M270 

11369 


Per- 

Density at 

centage 

16°C. 

14 

1-1467 

16 

11 674 

16 

11668 

17 

11770 

18 

.      1-1876 

19 

M971 

20 

1*2074 

21 

1-2168 

22 

1*2274 

23 

1-2375 

24 

1-2473 

25 

1-2572 

Per- 
centage 


5 
10 
15 
20 
25 


Density  at 
26'»C. 


Density  at 
85^0. 


1-0503 
1-1022 
11522 
1-2004 
1*2483 


1-0450 
1-0960 
1-1460 
11920 
•1-2407 


Density  at 


1-0356 
1*0850 
1-1346 
1*1801 
1-2295 


For  further  particulars  regarding  the  manu- 
facture of  alummium  sulohate,  see  The  Mineral 
IndustiT,  iii.  25;  and  Manufacture  of  Alum 
and  other  Salts  of  Alumina,  bv  L.  Geschwind, 
Scott,  Greenwood  and  Co.,  Ix>ndon. 

The  production  of  aluminium  sulphate,  alum 
cake,  alums  and  other  aluminium  compounds 
is  carried  out  in  large  quantities  in  the  united 
States.  The  total  output  of  these  products  in 
1912  approached  160,000  tons,  and  rose  steadily 
to  296,000  tons  in  1917. 

For  tiie  detection  of  free  acid  in  aluminium 
sulphate,  a  dilute  solution  of  Gongo  red  is 
usnul,  becoming  blue  in  presence  of  free  acid, 
but  is  not  affected  by  the  pure  salt. 

For  the  estimation  of  the  free  acid,  a  weighed 
quantity  (20  to  50  grams)  of  the  sample  is  dis- 
solved m  40  to  100  C.C.  of  water,  the  solution 
heated  to  boiling,  and  titrated  with  normal 
caustic  soda  until  a  drop  of  the  liquid,  taken  out 
with  a  glass  rod,  fails  to  yield  a  blue  colour  when 
mixed  with  six  drojps  of  Congo  red  solution 
(prepared  by  dissolving  0*067  gram  of  Congo 
red  m  1(X)  c.c.  of  boiling  water  and  diluting  to  a 
litre).  The  presence  of  iron  salts  interferes  with 
this  method  as  ferric  sulphate,  for  example, 
reacts  acid  towards  Congo  red. 

T.  J.  I.  Craig  (J.  Soo.  Chem.  Ind.  1911,  184) 
proposes  to  determine  the  free  acid  in  aluminium 


174 


ALUMINIUM. 


stilphate  by  treating  the  latter  with  exoesB  of 
neutral  potassium  fluoride,  whereby  the  double 
salt  AlFg'3KF  is  formed  together  with  potassium 
sulphate.  As  these  proauots  are  neutral  to 
phenolphthalein,  the  fiee  acid  present  may  be 
directly  titrated  with  a  standard  solution  of 
potassium  hydroxide. 

Iron,  in  the  ferrous  condition^  is  estimated 
by  titration  with  decinormal  potassium  per- 
manganate, and  total  iron  by  means  of  standieurd 
titanouB  ohloride  solution  {v.  Knecht  and 
Hibbert,  New  Reduction  Methods  in  Volumetric 
Analysis ;  and  Ber.  1903, 1660).  If  the  quantity 
of  iron  present  be  very  small,  it  Ib  determined 
colorimetrioaUy  (v.  Alums). 

Several  basic  aluminium  sulphates  have  been 
prepared.  The  compound  A1^0f^0^l2B.fi  is 
obtahied  b^  heating  a  solution  of  aluminium 
sulphate  with  zinc,  or  by  ^ssolving  in  it  the 
calculated  quantity  of  aluminium  hydrate. 
Spence  and  Sons,  Limited  (D.  R.  P.  1903, 
167419),  prepared  a  basic  sulphate  of  similar 
composition  oy  heating  sulphuric  acid  under 
pressure  with  16  to  30  p.c.  more  alumina  than 
IS  required  for  the  formation  of  the  normal  salt. 
The  solution  is  then  treated  with  sufficient  chalk 
or  lime  to  raise  the  basicity  by  20  to  28  p.c. 
The  strongly  basic  Qplntion  is  rapidly  filtered  and 
concentrated  in  vacud  until  its  density  reaches 
1*46.  On  cooling  with  agitation,  a  magma  of 
crystals  is  formeid  and  is  separated  by  suit- 
able means  from  the  mother-liquor  which 
contains  normal  aluminium  sulphate  (c/. 
also  Eng.  Pat.  1902,  26083,  and  Fr.  Pat.  1903, 
331836). 

Aluminium  snlpliite  Al,Oa(SO,)|. 
The  bisulphite  has  been  used  by  Becker 
(1.  poly.  J.  267,  300),  Snchomel  (J.  Soc. 
I.  Ind.  1887, 143)  and  others,  for  the  purifi- 
cation of  beet  sugars.  Becker  prepares  for  this 
purpose  a  solution  of1ip.gr.  1*167  containing  4*37 
p.c.  alumina  and  13*9  p.c.  sulphurous  oxide,  bv 
dissolvins  the  hydratea  oxide  m  sulphurous  acid. 
Alununlom  phosphates.  As  hydrated  phos- 
phate, aluminium  occurs  in  the  turqtioise,  and 
enters  into  the  composition  of  wavdlite,  lazti- 
liU  and  gibhsUe.  It  \b  found  in  considerable 
quantiijr  in  mineral  phosphates,  as  in  tiie 
Kedonda  phosphates  wnioh  nave  been  used  for 
the  preparation  of  alum  and  for  fertilisers  (v. 
Alums  ;  Manures).  A  massive  stony  variety 
ifl  found  on  the  island  of  Anguilla  in  the  West 
Indies. 

Aluminium  tblocyanate  or  sulphoeyanate 
has  been  proposed  as  a  substitute  for  aluminium 
acetate  for  alizarin,  steam  reds,  &c. ;  the  colours 
produced  are  said  to  be  especially  permanent 
{v.  Storch  and  Stiobel,  Bingl.  poly.  J.  241,  464  ; 
and  Gottlieb  Stein,  Dingl.  poly.  J.  260,  36). 

Lauber  and  Haussmann  (Bingl.  polv.  J.  246, 
306)  recommend  the  following  method  of  prepara- 
tion :  6  kilos  aluminium  sulphate  are  mssolved 
in  6  litres  boiling  water,  260  grams  of  chalk  are 
added,  followed  oy  11*6  litres  of  crude  calcium 
thiocyanate  solution  of  30**  Tw.,  and  the  whole 
well  stirred  and  allowed  to  settle.  The  clear 
liquid  is  ready  for  use. 

Aluminlmn  pennanganate  v.  Manganese. 

Aluminium  sllleatos.    These  compounds  are 

exceedingly  numerous  and  important.    As  an 

anhydrous  silicate,  with  silicate  of  iron,  calcium, 

magnesium,  &c.,    aluminium    occurs    in    the 


varieties  of  garnet,  onnBtallising  in  the  r^ular 
system.  As  silicate  of  aluminium,  calcium,  and 
sodium  it  is  found  in  lapis-lazuli,  which  was 
formerly  used  as  uUramarine,  It  is  now  re- 
placed by  artificial  ultramarine  (v.Ultbamabine). 
As  silicate  of  aluminium,  combined  with 
potassium,  iron,  and  magnesium,  it  occurs  in 
the  micM,  As  double  silicate  of  aluminium, 
potassium,  sodium,,  magnesium,  or  oaldum,  it 
forms  the  varieties  of  felspar  which  occur  in 
immense  quantities  in  eruptive  rocks.  By  the 
decomposition  of  felspar  by  the  carbonic  acid  in 
the  atmosphere  and  m  rain  or  spring  water,  the 
alkaline  compounds  are  removed,  leaving  kaolin 
or  clay  of  more  or  less  purity  {v.  Clay),  which, 
under  pressure,  becomes  nardened  and  laminated, 
forming  shale,  and  finally  slate  {q,v,).  Many  of 
the  sihcates  of  aluminium  are  of  great  impor- 
tance, and  of  the  widest  application.  The  more 
important  of  them  are  specially  considered  under 
their  applications  (v.  Pottery  ;  Poroelain). 

Aluminium  aeetate.  Red  liquor  (v.  Ahuni- 
nium  acetates,  art.  Agetio  acid). 

Aluminium  ethozlde  is  prepared  by  treating 
anhydrous  alcohol  with  aluminium  in  ptesenoe 
of  a  small  quantitv  of  mercuric  chloride  (as  a 
catalyst)  and  iodine  or  alkyl  haloids.  The 
mixture  is  dUtiUed  under  reduced  pressure  when 
a  distillate  free  from  mercury  is  obtained 
(Farbwerke  vorm.  Meister  Lucius  and  Briining, 
D.  R.  P.  286696 ;  J.  Soc.  Ghem.  Ind.  1916, 
34,  1168). 

Aluminium  oleate  is  a  soft  white,  putty-like 
substance,  of  great  tenacity,  insoluble  in  water, 
soluble  in  ether  and  petroleum.  A  mixture  of 
oleate,  palmitate,  ana  other  fatty  salts  is  pro- 
duced from  whale,  cotton-seed,  and  similar 
oils  by  saponification  with  soda  and  addition 
of  the  sodium  salt  so  produced  to  a  solution  of 
alum.  The  gummy  precipitate  is  known  as  '  oil 
pulp,'  and  is  dissolved  in  4  or  6  parts  of  mineral 
oil  to  form  a  *  Uiickener '  for  addition  to  the 
lubricator.  A  sample  of  oil  pulp  resembling 
thick  gelatia  had  a  8p.gr.  of  0*921,  and  containea 
6  p.o.  alumina  combmed  with  30  p.o.  fatty  acids, 
together  with  16  p.c.  lard  oil,  and  48  p.c.  paraffin 
oir(Oil  and  Golourman's  Joum.  4,  403). 

Aluminium  palmitate  is  a  constituent  of  oil 
pulp.  It  may  be  prepared  in  the  same  manner 
as  tne  oleate,  from  palm  oil.  It  forms  a  resinous, 
elastic,  inodorous,  neutral  substance,  insoluble 
in  water,  but  readily  soluble  in  petroleum  and 
turpentine.  K.  laeber  (Dingl.  poly.  J.  246,  165) 
recommends  the  use  of  the  latter  solution  as  a 
varnish.  It  imparts  a  glossy  appearance  to 
paper,  leather,  &c.,  and  renders  them  waterproof 
without  affecting  their  elasticity. 

The  compounds  of  aluminium  with  the  higher 
fatty  acids  are  used  for  increasiiifi  the  viscosity 
of  mineral  lubricating  oils,  under  the  names 
*  oil  pulp  *  and  *  fluid  gelatin  *  (L.  Marquardt» 
Zeitsch.  anal.  Chem.  26,  169).  G.  H.  B. 

ALUMINIUM  BRONZE  v.  Aluminium. 

ALUMINIUM  FOIL  AND  POWDER,  Manu- 
facture  of.  The  following  is  an  account  of  the 
processes  conducted  at  La  Praz  and  Charleville- 
sur-Audelle  bv  the  Soci6t6  fran^aase  de  Couleun 
me'talliques,  for  the  manufacture  of  aluminium 
foil  and  powder.  In  the  manufacture  of  alumi- 
nium foil  the  metal,  delivered  to  the  works  in 
the  form  of  ingots,  700  x  320  x  120  mm.  (cast  at 
760°-775*»  C.)  w  first  hot-roUed  at  420°  C.  to  a 


ALUMS. 


175 


(hiobiess  of  3*6  m.  and  then  out  into   strips 
8  cm.  ^de,   which,  after  being  annealed  at 
420°  C,  are  cold-rolled  to  0*04  mm.  in  six  staees, 
further    re4iiction    in    thickness    being    tnen 
effected  by  continued  roUing  or  by  hammering. 
In  the  former  case  the  metal  bands  are  first 
greased,  then  rolled  in  pairs  to  0'02  mm.,  and 
subsequently  in  fours  to  the  desired  thickness 
of  0*01  mm.,  the  foil  thus  being  obtained  in 
lengths  of  about  16  m.    In  the  latter  case,  the 
bands  are  made  into  packets  of  500  each  and 
beaten  by  pneumatic  hammers,  each  packet 
being  plaoea  between  two  thin  sheets  of  zinc ; 
when  the  thicbiess  of  the  metal  reaches  0*03  mm. 
the  packets  are  hammered  in  pairs  to  0*02  mm., 
and  then  in  fours  to  0*01  mm.    The  wastase  in 
either  case  is  very  considerable,   only  about 
33-35  p.o.   of  the  0*04  mm.  metal  employed 
beine  ootained  as  good  foil,  one  square  inch  of 
whicn  weighs  about  27  grams ;  the  waste  foil 
is  used  for  the  production  of  aluminium  powder. 
Before  being  finally  trimmed  and  cut  to  size, 
the  sheets  (3  foil  are  either  mechaniccdly  sepa- 
rated, or  embossed  by  means  of  suitable  rolls, 
sinoe—in  the  absence  of  the  layers  of  air  thus 
introdnoed  between  the  sheet»— the  metal  is 
liable  to  become  autogenously  soldered  at  the 
cut  edges.    In  the  manufacture  of  aluminium 
powder  it  has  been  found  necessary  to  employ 
the  foil  as  the  raw  material,  the  powder  yielded 
by  other  forms  of  the  metal  being  of  too  granular 
a  character  for  use  in  the  prejparation  of  paint. 
The  comminution  of  the  foil  is  conducted  in  a 
series  of  stamp  nulls,  in  each  of  which  the  closed 
mortar-box  is  provided  with  a  circle  of  twelve 
stamps  actuated  from  a  central  shaft,  to  the 
lower  end  of  which  a  scraper  or  plough  is 
attached.    Caking  of  the  metal  is  prevented  by 
the  scraper,  which  also  causes  the  charge  to 
be    periodically    thrown    against    the    screen 
inserted  in  the  side  of  the  mortar ;  the  screen  is 
provided    with    an    exterior    sliding    box    for 
collecting   the   metal  passing   through.    After 
further  classification,  tne  finer  portion  of  this 
product  is  mixed  with  about  2  p.o.  of  stearine 
(to    preTent    agglomeration    and    autogenous 
soldering  of  the  particles  during  the  fine  grind- 
ing) and  passed  to  a  second  series  of  stamp  mills, 
the  product  from  which  is  screened  through  silk 
bdUang  cloth  (No.  200).    The  powder  passing 
through  the  latter  is  then  classified  by  a  kind 
of  winnowing  process  in  *  elevators,'  each  com- 
prising   a    vemcal    brass    cylinder,    2  m.  high 
and   O'SOm.  in   diameter,  in  which   a  central 
vertical  spindle — ^to  which  horizontal  wings  or 
paddles  are  attached — ia  adaptelA  to  rotate,  and 
provided  with  receptacles  arranged  at  diff^^nt 
tevels  upon  a  helical  rail  attached  to  the  inner 
wall.     The  powder  is  fed  through  a  tube  into 
the  lower  part  of  the  cylinder,  the  rotation  of 
the  spindle  being  so  adjusted  that  the  lighter 
paitioles  or  flakes  become  suspended  in  the  air, 
and  are  deposited  in  the  peripheral  receptacles 
at  levels  coirespondinff   to  their   weight  and 
physical  condition;    the  coarser  particles  ro- 
mafnlng  at  the  bottom  of  the  cylinder  aro  ro- 
tnmed  to  the  fine-grinding;  miUs.    The  product 
from  the  *  elevators  *  is  mially  treated  for  ten 
hours    in    polishing    machines,    consisting    of 
horizontal,  rotatory  cylinders  of  striated  steel, 
t'20  m.    long  and  0*60  m.  in  diameter.      The 
polishing  of  the  metallic  powder  is  effected  by 


means  of  brushes  attached  to  the  axis  and 
bearing  upon  the  interior  wall  of  the  cylinder 
through  the  whole  of  its  length.  Since  condi- 
tions favourable  to  ignition  or  explosion  are 
liable  to  be  developed  within  the  fine-grinding 
mills,  elevators  and  poUshing  machines,  tiie 
various  units  are  of  relatively  small  capacity, 
and  are  so  disposed,  both  in  relation  to  each 
other  and  to  the  other  portion  of  the  works,  as 
to  localise  any  damage  that  may  arise  from  this 
cause  (Quillet,  Rev.  M^t.  1912,  9,  147 ;  J.  Soc. 
Chem.  Ind.  1912,  31,  339). 

ALUMNOLE.  [CioH50mSO,),],Al.  Trade 
name  for  aluminium  naphthol  sulphonate. 
Produced  by  the  action  of  aluminium 
sulphate  on  the  barium  salt  of  iS-naphthol 
disulphonio  acid  R.  Used  as  an  anti- 
septic. 

ALUMS.  Tins  generic  name  is  given  to  an 
important  group  of  double  salts  of  the  general 
type  Rt804,R'.0.(SOs)„24HaO,  where  R  is  a 
monovalent  metal  or  basic  radical  such  as 
potassium,  sodium,  ammonium,  &c.,  and  R'sO|' 
is  a  sesquioxide  such  as  that  of  aluminium,  iron, 
chromium,  or  manganese.  They  are  all  soluble 
in  water,  and  crystallise  therefrom  with  twenty- 
four  molecules  of  water,  in  forms  belonging 
to  the  regular  system,  usually  ootahedra  or 
cubes. 

The  alums  which  contain  the  sesquioxide  of 
alumina  will  alone  be  considered  here,  and  of 
these  the  most  important  are  the  potassium, 
sodium,  and  ammonium  compounds. 

'Selenic  alums'  have  been  prepared,  in 
which  sulphuric  add  is  replaced  by  seienio  acid. 

Potaauiim  alum,  Potash  alum 

K^04.A1,0,(S0,)„24H,0. 

This  salt  is  found  in  nature  as  keUinite,  in  the 
form  of  fibrous  crystals  or  as  an  efflorescence  on 
aluminous  minerals,  and  occasionally  also  in 
octahedra,  at  Whitby,  Campsie,  &c.  In  the 
Solfatara  near  Naples,  and  the  islands  of  Volcano 
and  Milo,  it  occurs  in  larger  quantities,  being 
formed  by  the  action  of  volcanic  gases  upon 
f elspathio  trachyte. 

Of  greater  importance  is  the  mineral  alunite 
or  alumslone,  which  is  a  double  salt  of  potassium 
sulphate  and  basic  aluminium  sulphate,  having 
the  composition  KsS04,Al,(S04)„2Als(OH)« ; 
it  is  found  at  La  Tolfa  near  Givita  Vecchia ;  at 
Montioni  in  the  Duchy  of  Piombino;  at 
Mursaly,  Munkact,  and  Tokay  in  Hungary ;  in 
the  islands  of  Milo,  Argentmo,  and  Nipoglio 
(Grecian  Archipelago);  at  Puy-de-Sanoy  and 
Madriat  (Auvergne) ;  at  Samsoun  in  Asia 
Minor ;  and  in  Australia.  An  *  alum  mountain," 
composed  of  this  mineral,  is  reported  to  exist  in 
CSiina,  and  is  stated  to  be  nearly  1900  feet  high 
and  to  have  a  cireumference  at  its  base  of  about 
ten  miles  (U.  S.  Clons.  Report,  1903). 

The  manufacture  of  alum  is  of  great  an- 
tiquity. In  the  time  of  Pliny  alum  was  m  use 
as  a  mordant  for  the  production  of  bright 
colours,  and  was  even  tested  by  means  of  the 
tannin  in  pomegranate  juice  to  ascertain  its 
purity.  It  was  prepared  in  the  thirteenth  cen- 
tury at  Smyrna  from  alum  rock,  and  since  the 
fifteenth  century  has  been  largely  produced  at 
La  Tolfa  from  the  same  substance. 

Its  preparation  from  pyritic  shale  has  long 
been  known,  together  with  the  fact  that  the 


176 


ALUMS. 


presence  of  an  alkali  was  necessaiy  to  induce 
crystallisation,  but,  until  proved  in  1797  by 
ChaptsI  and  Vauquelin,  the  essential  presence 
of  alkali  in  the  crystals  was  not  recognised. 

Vety  pure  alum  is  prepared  in  small  quan- 
tities at  Solfatara.  The  natural  alum  found  there 
is  digested  with  water  in  large  wooden  vats  under 
cover,  and  maintained  at  about  ■  40^  b^  the 
natural  heat  of  the  soil.  The  solution  is  de* 
canted  and  crysttUlised.  A  second  crystallisation 
produces  extremely  pure  alum. 

Production  of  alum  from  alunile. — ^The  pre- 
paration of  alum  from  alunite  is  an  industry 
which  dates  from  very  early  times.  Of  Oriental 
origin,  it  appears  to  have  been  introduced  into 
Europe  in  tne  thirteenth  century,  and  during 
the  fifteenth  century  several  alum  works  were 
established.  Amongst  these  mav  be  mentioned 
the  celebrated  works  at  La  ToJfa  near  Oivita 
Vecchia,  a  district  in  which  alum  manufacture 
still  ranks  as  an  important  industry. 

The  outline  of  the  La  Tolfa  process  given 
below  is  of  historical  interest.  The  mineral, 
broken  into  lumps  of  moderate  size,  is  calcined 
at  a  low  red  heat,  either  in  heaps  or  in  kilns. 
The  operation  requires  to  be  carefully  performed, 
and  is  stopped  as  soon  as  the  mineral  begins  to 
evolve  acid  fumes.  The  calcination  occupies 
about  six  hours  and  results  in  a  loss  in  weight 
amounting  to  about  33  p.c.,  chiefly  due  to  the 
expulsion  of  water ;  at  the  same  time  the  basic 
sulphate  is  decomposed,  yielding  alum  and  in> 
soluble  alumina.  The  roasted  mass  is  trans- 
ferred to  brickwork  bins  and  exposed  to  the 
air  for  several  months,  during  which  time  it 
is  occasionally  moistened.  The  resulting  sludge 
is  lixiviated  with  water  at  70^,  and  the  clear 
decanted  liquor  concentrated.  The  crystals  of 
alum  which  separate  on  cooling  are  cubic  and 
have  a 'reddish  tinge  owing  to  the  presence  of 
suspended  ferric  oxide ;  this  may  be  removed 
by  recrystallisation.  The  amount  of  soluble  iron 
present  is  stated  to  be  less  than  0*006  p.c.  The 
product,  known  as  Roman  alum,  was  in  former 
times  highly  valued  on  account  of  its  great 
purity. 

In  the  modem  process,  employed  on  the 
Continent,  the  alunite  is  calcined  at  a  higher 
temperature  and  the  product  treated  with 
sulphuric  acid,  whereby  aluminium  sulphate  is 
formed  from  the  excess  of  alumina,  ana  passes 
mto  solution  together  with  the  alum.  The 
latter  b  either  crystallised  out,  and  the  more 
soluble  aluminium  sulphate  recovered  as  such 
from  the  mother  liquors,  or  sufScient  potassium 
sulphate  is  added  to  convert  the  whole  of  the 
aluminium  sulphate  into  alum. 

According  to  C.  Schwartz  (Ber.  17,  2887), 
the  best  temperature  for  the  roasting  is  500*, 
and  the  acid  used  should  have  a  density  between 
1-297  and  1-530.  I^  Geschwind  (Manufacture 
of  Alum  and  the  Sulphates  of  Alumina  and 
Iron,  1901),  however,  states  that  in  France  a 
temperature  of  about  1000*  is  employed. 

Formerly,  the  greater  portion  of  the  alum 
manufactured  in  England  was  prepared  from 
alum  shale  (alum  ore),  alum  schist,  and  similar 
minerals,  which  occur  in  lai^  quantities  at 
Whitby  in  Yorkshire,  Hurlet  and  Campsie  in 
Scotland,  in  Sweden,  Norway,  Belgium,  and  in 
several  parts  of  Thuringia,  Westphalia,  &c. 
These    minerals    are    mixtures    of    aluminium 


silicate,  m>n  pyrites,  and  bituminous  substances ; 
the  iron  pyrites  is  principally  present  in  tUo 
aluminous  schists  as  a  fine  black  powder, 
disseminated  throughout  the  msfs,  and  not 
distinguishable  to  the  eye.  The  rapid  oxidation 
of  these  minerals  under  atmospheric  influences 
or  heat  is  due  to  this  state  of  fine  division. 

Aluminous  earths  are  dark  brown,  friable, 
porous  masses-  without  structure,  and  contain 
less  silica  than  the  schists.  They  usuaUy  oocur 
in  layers  with  lignite. 

Produciion  of  aJum  from  aluminous  shale. — 
The  more  earthy  shales  are  porous,  and  if  piled 
in  heaps  in  the  open  air  and  occasionally  mois- 
tened underao  spontaneous  oxidation,  with  the 
formation  of  sulphates  of  iron  and  aluminium. 
Usually  they  require  roasting,  and  when  not 
sufficiently  bituminous  for  combustion,  are  first 
mixed  with  fuel. 

The  coarsely  broken  shale  is  built  up  with 
alternate  layers  of  coal  into  heaps,  which  are 
iffnited.  As  the  mass  bums,  fresh  quantities  of 
the  mineral  are  added,  until  a  sufficient  mass  of 
material  has  been  accumulated.  By  pumping 
water  over  the  surface  at  intervals  the  tempera- 
ture is  regulated  to  a  degree  suitable  for  rendering 
the  decomposition  as  complete  as  possible.  Too 
high  a  temperature  is  to  be  avoided,  as  it 
results  in  the  loss  of  sulphur  dioxide  and  the 
formation  of  a  slag.  During  the  combustion 
of  the  shale  the  pyrites  is  decomposed,  giving 
up  a  portion  of  its  sulphur,  which  is  converted 
by  burning  into  sulphur  dioxide,  and  this  in 
conjunction  with  atmospheric  oxygen  attacks 
the  clay,  forming  aluminium  sulphate.  The 
calcined  mass  is  allowed  to  remain  exposed  to 
the  air  for  a  considerable  period,  during  which 
a  further  absorption  of  oxygen  takes  place, 
resulting  in  the  conversion  of  the  lower  sulphide 
of  iron  into  ferrous  sulphate  and  ferric  oxide. 

Lixiviaiion, — 11)  is  operation  is  carried  out 
in  large  lead-lined  boxes  with  perforated  bottoms, 
the  filtering  bed  being  formed  of  timber  topped 
with  brushwood.  A  layer  of  the  roasted  mineral 
about  13  inches  deep,  is  introduced  and  its 
extraction  is  effected,  first  with  the  mother 
liquor  from  the  alum  crystiUlising  pans,  and  later 
with  pure  water,  the  Uquid  in  each  case  being 
left  overnight  in  contact  with  the  materiaL 

The  exhausted  mineral  still  contains  a 
considerable  amount  of  alumina  and  solphurio 
acid.  The  liquors,  which  have  a  density  of 
1-09  to  1-15,  an  run  into  settling  tanks  and 
allowed  to  deposit  calcium  sulphate,  ferric  oxide^ 
and  other  suspended  impurities,  and  are  then 
removed  for  copoentration.  The  method  adopted 
for  this  purpose  varies  according  to  the  nature 
of  the  mineral  under  treatment.  In  the  case 
of  shales  from  Hurlet  and  Campsie  the  oonoen- 
tration  is  effected  by  surface  evaporation  in  a 
reverberatoi^  furnace. 

The  bed  is  of  stone,  coated  with  well-rammed 
clay,  4  or  6  feet  wide,  2  or  3  feet  deep,  30  or  40 
feet  long.  It  is  filled  to  the  biim  with  strong 
liquor,  and  the  flame  and  hot  air  from  the  fire 
carried  over  it.  As  evaporation  prooeeds,  more 
liquor  is  added  until  the  proper  concentration 
is  reached.  It  is  then  run  into  leadt>n  pans, 
concentrated  to  about  1-4  sp.sr.  and  conveyed 
to  a  precipitating  cistern  contaming  the  reauiaite 
quantity  of  drv  potassium  chloride ;  the  liquid 
is  well  agitated  and  the  chloride  soon  dissolves. 


ALUMa 


177 


In  aboQt  5  days  the  liquor  is  drained  from  the 
Uifie  oiyatalB,  whioh  are  waahed  and  reoxyetallised. 

The  Whitby  shales  differ  from  those  at 
Hurlet,  in  that  they  contain  a  considerable 
quantity  of  magnesia  which  jMsses  into  the 
extract  in  the  form  of  maenesium  sulphate.  In 
this  case  surface  evaporation  is  not  satiafaotoi^ 
on  account  of  the  formation  of  a  crust  of  this 
salt  which  retards  evaporation.  The  evapora- 
tion of  the  liquor  is  carried  out,  therefore,  in 
leaden  vessels,  untfl  a  sp.gr.  of  1*125  to  1*137  is 
reached,  after  which  the  solution  is  allowed  to 
stand  until  dear.  The  concentration  is  con- 
tinued up  to  sp.gr.  1  -25,  at  which  stage  a  sample 
of  the  liquor  is  withdiawn  and  the  percentage 
content  of  aluminium  sulphate  determines. 
After  further  evaporation  to  a  density  of  1-4  to 
I'fi,  the  hot  liquor  is  run  into  a  preoipitatins 
tai:^  and  mixed  with  a  saturatea  solution  c3 
the  calculated  quantity  of  potassium  chloride 
or  sulphate,  the  whole  being  kept  in  constant 
agitation  to  induce  the  formation  of  small 
crystak  (alum  meal). 

When  much  ferric  sulphate  is  present  in  the 
solution,  the  addition  of  potassium  sulphate 
would  produce  iron  alum,  isomorphous  with  ordi- 
nary alum,  which  would  o^stallise  out  and  con- 
taminate the  product.  Tne  use  of  potassium 
chloride  prevents  this,  by  producing  the  easily 
soluble  ferric  chloride,  while  ferrous  salts  are 
converted  into  the  equally  soluble  ferrous 
chloride,  an  equivalent  amount  of  potassium 
sulphate  bein^  tormed  at  the  same  time.  Chloride 
of  potassium  is  generally  employed  in  preference 
to  the  sulphate,  whenever  sufficient  iron  sulphate 
is  present  to  supply  the  requisite  amount  of  sul- 
phurio  acid  for  we  formation  of  alum ;  its 
greater  solubility  is  also  in  its  favour.  Too  much 
chloride  should  be  carefully  avoided,  for  after 
the  iron  sulphates  have  been  decomposed,  the 
aluminium  sulphate  is  itself  attacked,  with  the 
fnroduction  of  the  very  soluble  chloride,  which 
is  lost. 

The  okcm  meal,  consisting  of  small  brownish 
crystals,  is  drained  and  washed  twice  with  oold 
water.  The  adhering  mother  liquor,  containing 
much  iron,  is  thus  removed,  and  the  meal  is  left 
nearly  pure.  The  final  purification  is  effected  by 
dissolving  m  a  minimum  quantity  of  boiling 
water  and  allowing  the  solution  to  stand  for 
about  eight  days  in  casks  furnished  with  movable 
staves.  At  the  end  of  this  period  the  staves 
are  removed,  and  after  two  or  three  weeks 
further  standing,  the  block  of  crystals  is  pierced, 
the  mother  liquor  drained  off  and  employed  for 
dissolving  fresn  quantities  of  meal. 

The  mother  liquor  from  the  alum  meal  has  a 
8p.gr.  of  about  14;  it  contains  sulphate  or 
chloride  of  iron,  magnesium  sulphate,  &c.,  and 
will  yield  more  alum  on  evaporation.  In  a  final 
evaporation  it  yields  ferrous  sulphate  in  fine 
green  crystals.  When  iron  is  present  in  laree 
quantity,  the  liquors  are  evaporated  and  the 
ferrous  sulphate  crystallised  out  before  the  ad- 
dition of  tne  potassium  salt.  In  this  case  the 
iron  salt  is  less  pure  and  less  soluble,  but  the 
alam  subsequently  produced  contains  less  iron. 

Formerly,  potassium  alum  was  alone  pro- 
duced. In  1845,  however,  the  potassium  sul- 
phate was  replaced  by  the  ammonium  sulphate 
produced  from  the  then  waste  liquors  from  gas 
works,  yielding  ammonium  alum.     This  great 

Vol.  1.— T. 


improvement  was  introduced  by  the  late  Peter 
Spenoe ;  his  method  was  soon  generally  adopted 
both  in  ^gland  and  on  the  Continent. 

Another  great  advance  was  made  by  Spence 
in  1845  in  tne  manufacture,  by  the  treatment 
of  the  refuse  shale  underlying  the  coal-seams 
of  South  Lancashire.    This  shale  contains  from 
5  to   10  p.c.   of  carbonaceous  matter.    It  is 
piled  upon  rows  of  loosely  placed  bricks  (to 
allow    a   free  paasaee    to    the    air)  in   heaps 
4  or  5  feet  high  and  20  feet  long.    The  com- 
bustion is  started  with  a  little  fuel,  but  the  shale 
contains  sufficient  combustible  matter  to  con- 
tinue burning.    The  calcination  is  performed 
slowly  at  a  heat  below  redness.    In  about  10  days 
the  roasting  is  completed,  and  the  material  has 
become  son,  porous,  and  light  red,  whilst  the 
alumina  contained  in  it  has  become  anhydrous 
and  soluble  in  sulphuric  acid.    Too  high  a  tem- 
perature, however,  partially  vitrifies  it,  in  which 
case  it  is  only  slowly  attacked  by  acid.    Chaxges 
of  20  tons  are  placed  in  larae  covered  pans  40 
feet  long,  10  feet  wide,  and  3  feet  deep,  lined 
wit^  IcM,  and  are  dig^ted  for  about  48  hours 
with    sulphuric   acid    (of  8p.gr.  1*35)  at  110*, 
the  temperature  being  maintained  by  fires  be- 
neath the  boilers.  Formerly  ammonia  was  forced 
into  the  liquid  from  a  boiler  containing  gas 
liquor';  ammonium  sulphate  was  thus  pro£iced„ 
with  considerable  rise  of  temperature,  and  com- 
bined with  the  aluminium  sulphate  forming  am- 
monium alum.    The  solution  of  alum  so  pro- 
duced is  run  into  cisterns  29  feet  by  17  feet,  and 
1}  feet  deep,  in  which  it  is  kept  in  constant 
agitation.     In  about  14  hours  the  small  crystals 
so    formed    are    drained,    washed    with    some 
mother  liquor  from  *  block  alum,'  and  dissolved 
by  a  process  known  as  *  rocking '  for  the  pro- 
duction of  pure  block  alum.    For  this  purpose 
they   are   introduced   into   a   hopper,    at   the 
bottom  of  which  they  encounter  a  current  of 
steam  at  a  pressure  of  20  lbs.  per  sq.  inch,  both 
steam    and    crystals    being    supplied    in    such 
proportions  that  all  the  crystals  are  dissolved, 
while  no  steam  is  wasted.    In  this  manner  4 
tons  of  crystals  ma^  be  dissolved  in  30  or  40 
minutes.    The  solution  is  run  into  a  leaden  tank, 
and,  after  a  time,  treated  with  a  small  quantity 
of  size,  which  precipitates  a  quantity  of  insoluble 
matter.    The  dear  liquid  is  next  run  into  tubs 
about  6  feet  high  and  6  feet  wide,  tapering 
upwards,  with  movable  lead-lined  staves.    After 
some  days  the  staves  are  removed  and  a  hole 
is  bored  in  the  mass  of  cnrstals  for  the  removal 
of  the  liquor.     £!ach  blocx  weighs  about  3  torn, 
while  the  mother  liquor  container  about  1  ton. 

To  produce  1  ton  of  ammonium  alum  by 
this  method  on  an  average  about  15  cwts.  of  the 
shale  is  required. 

A  great  advantage  of  this  process  is  the 
speed  with  which  the  crude  material  is  con- 
verted into  marketable  alum.  By  the  old  pro- 
cess twelve  months  was  required  for  this  con- 
version, whilst  by  Spence's  process  the  whole 
operation  is  periormed  in  one  month.  For  this 
process  Spence  was  awarded  the  medal  for 
alum  manufacture  at  the  Exhibition  of  1862,  at 
which  date  he  manufactured  150  tons  of  alum 
weekly,  over  one-half  the  total  production  of 
England  (t;.  Hofmann's  Report  on  Chemical 
Processes  at  the  Exhibition  of  1862,  p.  62,  and 
I  J.  Carter  Bell,  Chem.  News,  12,  221). 

V 


178 


ALUMS. 


Alum  U  ftbo  produced  b^  the  addition  of  1 
potassium  sulphate  to  aluminium  sulphate,  pre- 
pared by  any  of  the  processes  already  described. 
It  is  prepared  in  great  purity  from  the  sulphate 

Sroduoed  from  cryolite ;    1  ton  of  cryolite  pro- 
uces  3  tons  of  alum  (v.  Sodium  aluminaU), 

Many  other  processes  have  been  proposed 
and  used  for  the  preparation  of  alum. 

Spence,  in  1870  (Ene.  Pat.  1676),  patented  a 
method  of  preparing  alum  from  mineral  phos- 
phates, especially  that  from  Redonda  near 
Antigua,  wnich  contains  26-1  p.o.  of  alumina  as 
phosphate  with  ferric  oxide  and  silica.  It  is 
calcined  at  a  red  heat  to  render  it  porous, 
powdered,  and  di^^ested  with  sulphuric  acid  of 
sp.gr.  1*6  in  quantity  proportional  to  the  amount 
of  iQumina,  in  lead-hned  vessels,  heated  by  steam. 
The  liquid  is  concentrated  to  a  density  of  1*45, 
and  treated  with  the  requisite  amount  of  potas- 
sium sulphate  to  convert  the  whole  of  the 
alumina  mto  alum.  Phosphate  containing  20 
p.c.  of  alumina  yields  about  1}  times  its  weight 
of  alum,  from  which,  however,  the  last  triMes 
of  phosphoric  acid  are  removed  with  difficulty. 
The  phosphoric  acid  in  the  mother  liquors  is 
valuaole  as  a  manure. 

Methods  have  frequently  been  proposed  for 
the  preparation  of  alum  from  felspar.  Or^nary 
felspar  contains  both  potassium  and  aluminium 
combined  with  silica  in  larger  proportions  than 
are  contained  in  alum  ;  the  problem  to  be  solved 
is  the  substitution  of  sulphuric  acid  for  silica. 
A  method  adopted  by  Turner,  said  to  have  been 
originated  by  bprengel,  consisted  in  the  ignition 
of  a  mixture  of  one  part  of  the  powdered  mineral 
with  one  part  of  potassium  bisulphate  until 
fused ;  one  part  of  sodium  carbonate  was  then 
added,  and  the  whole  again  fused.  The  mass 
was  boiled  with  water  and  the  insoluble  double 
silicate  remaining  was  decomposed  by  hot  sul 
phuric  acid  of  6p.gr.  1*20,  and  the  alum  crystal 
Used  out.  On  account  of  the  high  tempenture 
required,  this  process  was  not  successful. 

At  the  present  time  the  bulk  of  the  alum 
manufactured  in  England  is  prepared  either 
from  shale  or  alunite  or  from  the  aluminium 
sulphate  derived  from  bauxite  or  china  clay. 

For  the  more  delicate  dyes  the  alum  used 
must  be  of  extreme  purity.  Samples  containing 
even  less  than  O'OOl  p.c.  of  iron  may  be  unsuit- 
able for  certain  purposes.  The  percentage  of 
iron  in  alum  or  in  aluminium  sulphate  is  usually 
determined  by  means  of  a  solution  of  ammonium 
thiocyanate  standardised  with  iron  alum.  Many 
precautions  are  necessary  in  performing  the 
analysis  (v.  Tatlook,  J.  Soc.  Ghem.  Ind.  1887, 
276 ;  G.  Lunge,  Mon.  Sci.  1897,  160). 

Potash  alum  crystallises  with  24  molecules 
of  water,  in  cr^tals  belonging  to  the  cubic 
system,  usually  m  large  colourless  octahedra  of 
sp.gr.  1*751  (Betgers,  Zeitsch.  physikal.  Chem. 
3,  289 ;  J.  B.  1889,  148). 

De  Boisbaudran  has  also  obtained  it  crystal- 
lised with  hemihedral  faces  of  the  tetrahedron. 
The  crystalline  form  is  affected  by  the  presence 
of  other  substances  in  solution,  and  by  the  tem- 
perature. When  formed  at  ordinary  tempera- 
tures in  the  presence  of  basic  alum,  the  crystals 
are  cubes,  frequently  dull  on  the  surface  from 
the  presence  of  the  basic  salt;  for  this  reason 
Roman  alum  usuallv  forms  cubes.  At  40°  C, 
^en  in  presence  of  basic  salts,  octahedra  are 
Dduced* 


Potash  alum  possesses  the  propartr  of 
crystallising  with  hydrooen  peroxide  (Will- 
statter,  Ber.  36,  [1903]  1828). 

According  to  Poggiale  (Ann.  Ghim.  Phys.  [3] 
8,  467),  the  solubility  of  potash  alum  and  of 
ammonia  alum  is  as  follows : — 

100  parts  water  dissolve  : 


'C. 

Grystallliied 

CryBUUlaed 

Potaah  alum. 

Ammonia  alum. 

0 

3-9 

5-2 

10 

9-6 

91 

20 

161 

13-6 

30 

22-0 

19-3 

40 

30-9 

27-3 

60 

441 

36-6 

60 

66-6 

61-3 

70 

90-7 

720 

80 

134-5 

103-0 

90 

209-3 

187-8 

100 

357-5 

421-9 

Conductivity  determinations,  made  on  alum 
solutions  of  different  concentrations,  indicate 
that  even  at  moderate  dilutions  the  alum  is 
resolved  into  its  component  salts. 

Potash  alum  possesses  a  sweetish  astrin- 
gent taste  and  a  strongly  acid  reaction.  The 
aqueous  solution  decomposes  when  heated  with 
precipitation  of  a  basic  alum,  especiaUpr  when 
dilute.  For  this  reason  a  sniall  quantity,  not 
sufficient  to  be  distinguished  by  taste,  is  fre- 
quently added  to  impure  water.  The  gelatinous 
precipitate  carries  with  it  the  colouring  matter 
and  most  of  the  organic  impurities,  producing  a 
slimy  deposit. 

Alum  is  almost  insoluble  in  a  saturated  sola- 
tion  of  aluminium  sulphate,  and  is  quite  insoluble 
in  alcohol.  On  exposure  to  air,  the  crystals 
become  white  on  the  surface.  TMs  change  is 
due,  not  to  the  loss  of  water,  but  to  the  absiarp- 
tion  of  ammonia  from  the  air,  with  formation  of 
a  basic  salt.  Below  30°  G.  they  lose  no  water ; 
at  42°  C.  they  evolve  11  molecules  (Juttk% 
Chem.  Zentr.  18,  777).  In  a  closed  vessel  over 
sulphuric  acid  they  lose  18  molecules  at  61°  CL 
(Graham)  and  become  slowly  anhydrous  at 
100°  C,  more  rapidly  in  a  current  of  air.  Alum 
melts  in  its  water  of  crystallisation  at  92-5°  C.» 
and  when  heated  to  dull  redness  is  converted 
into  a  porous  friable  mass,  slowly  soluble  in 
water,  known  as  'burnt  alum.*  At  a  white 
heat  alumina  and  potassium  sulphate  alone 
remain. 

When  burnt  alum  is  mixed  with  one-third 
its  weight  of  carbon  and  heated  to  redness,  the 
residue  is  spontaneously  inflammable  on  account 
of  the  presence  of  finely  divided  potassium 
sulphide,  and  is  known  as  Hombe4[*s  pyro- 
phorus.  By  fusing  alumina  with  pnotassium 
oisulphate  and  digesting  the  mass  in  irurm 
water,  anhydrous  potaaBitim  alum  may  be 
obtained  in  crystals  of  which  6  parts  are  soluUe 
in  100  of  water  at  10°  C.  and  74*5  parte  at 
100°  C.  (Salm-Horstmar,  J.  pr.  Chem.  52,  319). 

On  the  addition  of  caustic  soda  or  sodium 
carbonate  to  a  solution  of  alum  until  the  pre- 
cipitate at  first  produced  is  only  just  redissolved 
on  agitation,  i.e.  when  two-thiids  of  the  acid  has 
been  neutralised,  the  solution  contains  a  neutral 


ALUM-SHALB. 


179 


bade  almn,  known  as  neuirai  ahtm,  together 
witk  sodium  scdphate.  This  aolation,  on  ao- 
oonnt  of  the  ease  with  which  it  gives  up  its 
excess  of  alumina  to  the  fabric,  is  used  by  ayers 
as  a '  mordant.  Commercial  potash  alum  is 
frequently  mixed  with  ammonia  alum. 

Alum  is  extensiTely  used  as  a  mordant  in 
ihe  dyeing  industries,  and  in  the  production  of 
other  aluminium  mordants  such  as  the  acetate, 
sulphoacetate,  &o.,  employed  in  dyeing  and 
printing  and  for  diower-proofing  fabrics.  The 
alum  used  for  dyeing  with  alizarin  red  must 
be  free  from  iron,  mherwise  dull  shades  are 
produced.  It  is  also  employed  in  the  manu- 
ucture  of  lake  pigments,  in  the  dressing  of 
skins  (*  tawing ')  to  produce  white  leather,  in 
sizimr  paper,  and  in  the  production  of  fire- 
proonng  materials.  In  most  of  its  applications, 
howerer,  it  is  being  replaced  by  aluminium 
sulphate,  the  use  of  which  is  considerably  more 
economical. 

Sodium  alum.  Soda  alum 

Na^04.Al,0,(80a)^H,0 

occurs  as  mendozite  in  S.  America  and  in  Japan 
(Divers,  Ghem.  News,  44,  218). 

This  alum  was  prepared  by  ZeUner  in  1816, 
by  the  spontaneous  evaporation  of  a  solution 
containing  sodium  and  aluminium  sulphates. 
Its  existence,  disputed  by  Ostwald,  has  been 
established  by  Wadmore  (Chem.  Soc.  Proc. 
21, 160 ;  0.-B.  1905, 11, 18),  who  from  a  solution 
of  the  mixed  sulphates  obtained  octahedral 
crystals  having  the  above  composition.  From 
a  hot  concentrated  solution  it  is  deposited  on 
coolins  as  a  pasty  mass  which  slowly  becomes 
crystaDina  uontrary  to  the  statement  fre- 
quently made,  the  crystals  do  not  appreciably 
effloresce  in  the  air. 

Teohnioally,  soda  alum  may  be  prepared 
in  the  following  manner: — To  a  solution  of 
aluminium  sulphate  containing  675  grams  of 
the  crystalline  salt  per  litre^  and  maintained  at 
a  temperature  of  50^  0.  to  60^  C,  is  added  a 
solution  of  sodium  sulphate  containing  146 
grams  of  the  anhydrous  salt  per  litre,  until  the 
Squid  attains  a  density  of  I'SS;  crystals  of 
soda  alum  separate  on  cooling.  The  crystallisa- 
tion  diould  m  effected  at  a  temperature  between 
10^  G.  and  25''  G. ;  at  28""  G.  the  formation  of 
crystals  proceeds  very  slowly,  whilst  below 
10^  G.  separation  of  sodium  sulphate  occurs 
(Aiu4  B.IL  P.  1899,  50323  ;  J.  1890,  2635). 


F.  M.,  D.  D.,  and  H.  Spence  (£ng. 
Pat.  1900,  5644)  prepare  a  solution  of  sodium 
sulphate  saturated  at  40''  G.  to  50**  G.,  which  is 
allowed  to  cool  durins  acitation  until  a  consider- 
able proportion  of  £c&ydrated  crystals  have 
separated.  The  mixture  of  liquid  and  crystals 
is  then  run  into  a  solution  of  aluminium  sulphate 
containing  the  soUd  salt  in  suspension.  There 
is  thus  obtained  a  larse  crop  of  well-defined 
soda  alum  crystals.  Alternatively,  the  solid 
aluminium  sulphate  may  be  added  to  a  suitable 
solution  of  sodium  sulphate  or  chloride,  in  which 
either  salt  may  be  suspended  in  the  solid  state. 

Soda  alum  is  much  more  soluble  at  ordinary 
temperatures  than  potassium  or  ammonium 
alum,  in  consequence  of  which  it  is  more 
difficult  to  purify  from  iron.  On  account  of 
the  lower  cost  of  sodium  salts,  it  would  be 
largely  used  in  place  of    other  and   more  ex- 


pensive alums,  if  it  could  be  easily  purified  by 
crystalliBation  {see  Ens.  Pat.  1881,  5wO). 

Soda  alum  crystulises  with  24  molecules 
of  water  in  regular  octahedra,  having  a  sp.gr.  of 
1-667  (Soret).  At  10*6°  G.  100  parts  of  water 
dissolve  107*11  parts  of  the  alum  (Wadmore) ; 
according  to  Ure,  the  solution  saturated  at 
15*5'*  G.  contains  110  parts  of  the  alum  in  100 
of  water,  and  has  a  density  of  1*296.  Soda 
alum  is  insoluble  in  alcohol. 

Ammonium  almn.  Ammonia  alum 

(NHJ,804,A1,0,(S0,)„24H,0 

occurs  as  Tschermigite  in  Bohemia,  and  in  the 
crater  of  Mount  Etna. 

Its  preparation  is  analogous  to  that  of 
potash   alum,   a   solution   of   aluminium   sul- 

Shate,  prepaied  by  any  of  the  methods  already 
escribed,  being  treated  with  the  equivalent 
quantity  of  ammonium  sulphate,  and  the  alum 
separated  and  purified  by  cipnBtallisation. 

Ammonia  alum  crystallises  with  24  mole- 
cules of  water  in  regular  octahedra,  having  a 
conchoidal  fracture  and  a  density  of  1*631 
(Soret).  At  ordinary  temperatures  it  is  less 
soluble  in  water  than  potassium  alum  {v.  Table 
of  solubilitiea,  under  Potassium  alum).  The 
saturated  solution  boils  at  110*6°  G.,  and  con- 
tains 207*7  parts  of  the  alum  to  100  parts  of 
water  (Mulder).  When  heated  the  crystals 
swell  up  and  form  a  porous  mass,  losing  water 
and  smphuric  acid;  at  a  high  temperature 
alumina  alone  remains.  This  serves  as  a  useful 
method  for  the  production  of  very  pure  idumina. 

In  its  general  properties  and  usee,  ammonia 
alum  closely  resembles  the  corresponding 
potassium  compound.  G.  M.  B. 

ALUMKOL  v.  Stnthbtio  Dbuos. 

ALUM-SHALE.  A  kind  of  shale  or  slate 
containing  disseminated  iron-pyrites,  which,  on 
prolonged  exposure  to  the  weather,  gives  alu- 
minium sulphate,  owing  to  the  action  of  sul- 
phuric acia  (from  the  decomposition  of  the 
iron-pyrites)  on  the  clayey  material.  The  heaps 
of  weathered  shale  are  leached  with  water,  and 
to  the  solution  of  aluminium  sulphate  and 
sulphuric  acid  so  obtained  potashes  are  added. 
The  alum  obtained  by  the  evaporation  of  this 
solution  is  purified  by  recrystollisation.  The 
alum-shales  of  Liassio  age  on  the  coast  of 
Yorkshire,  in  the  neighTOurhood  of  Whitby, 
have  been  largely  worked  by  this  method  since 
the  time  of  Queen  Elizabeth,  but  now  the 
industry  has  become  extinct.  At  Alum  Bay 
in  the  Isle  of  Wight  clays  of  Tertiary  ace  were 
formerly  used  in  the  manufacture  of  amm,  as 
early  as  1579;  and  in  the  early  part  of  the 
eighteenth  century  the  Kimmeridge  clay  in 
Kimmeri<^e  Bay,  Dorsetshire,  was  also  so 
used.  Pyritous  shales  of  Garboniferous  age 
were  formerly  worked  at  Hurlet  in  Renfrewshire, 
large  works  for  the  extraction  of  alum  having 
been  erected  here  about  the  year  1800.  Alum- 
shales  in  the  coal-measures  of  the  West  Riding 
of  Yorkshire  are,  however,  still  worked  to  a 
small  extent  near  Rotherham,  Bamsley,  and 
Darton.  Here  the  iron-pyrites  is  more  effici- 
ently and  quickly  oxidisea  by  roasting  the  shale, 
which  is  aiterwards  steeped  in  shallow  pits,  and 
the  concentrated  liquor  treated  with  potassium 
chloride. 

Beference, — Special  Reports  on  the  Mineral 


180 


ALUM.SHALE. 


Beaouroes  of  Qreat  Britain,  vol.  ▼.  Mem.  Qeol. 
Snnrey,  London,  1916.  F.  Alums,  art.  Alumi- 
NTUM.  '       L.  J.  8. 

ALUNDUM.  A  form  of  fused  alumina 
manufactured  as  a  refractory  material  and 
abrasive.  As  used  in  the  preparation  of 
refractory  articles  it  is  a  white  crystalline  pro- 
duct containing  less  than  1  p.c.  of  impunties 
(oxides  of  iron,  titanium,  and  silicon) ;  it  melts 
at  2050''-2100°,  and  its  coefficient  of  linear 
expansion  is  0*0000078.  A  less  pure  form  con- 
taming  0-8  p.c.  of  impurities  and  of  a  reddish- 
brown  colour  is  also  employed;  it  melts  at 
about  60°  lower  than  the  white  variety,  and  its 
coefficient  of  expansion  is  0*0000085.  Alundum 
does  not  soften  when  within  100°  of  its  melting- 
point;  ^-gr.  3*93-4*0;  hardness  9-10  (Molrs 
scale).  Thermal  conductivity  3-4  times  that 
of  most  fire-clays.  Not  attacked  by  aqueous 
adds  and  alkaus,  and  only  very  slightly  b^ 
fused  alkali  carbonates.  IJissolved  with  dim- 
cultv  by  fused  slags  both  acid  and  basic,  more 
reamly  by  the  former.  For  the  preparation 
of  shaped  articles  it  is  mixed  with  a  refractory 
binding  agent,  moulded,  and  fired  in  a  ceramic 
kiln ;  the  articles  are  usually  more  refractory 
than  amorphous  alumina.  When  treated  with 
sulphuric  or  hydrochloric  acid  they  lose  up  to 
O'G^  p.c.  of  their  weight  but  are  then  quite 
unaffected.  The  articles  are  porous,  and  cannot 
be  used  where  gas-tight  vessels  are  required,  or 
as  protecting  tubeis  for  pyrometers.  The 
meltmg-point  of  the  bonded  articles  is  never 
below  1950°,  and  they  possess  great  stren^h, 
both  tensile  and  compressive ;  electrical  resist- 
ance 476x10'  ohms,  at  535°,  49x10*  at  721°, 
24  X 10*  at  908°,  and  7*5  x  10«  at  1040°.  Alun- 
dum muffles  last  4-5  times  as  long  as  clay  muffles, 
and  are  more  refractory  and  have  a  higher 
tensile  strength  than  quartz.  Crucibles  of 
alundum  can  oe  used  for  melting  metals,  even 
platinum.  On  account  of  their  porosity  they 
cannot  be  used  for  melting  slags  or  salts,  but 
this  quality  makes  them  specially  suitable  as 
a  substitute  for  Goooh  crucibles;  no  asbestos 
filler-layer  is  requiied»  and  the  porosity  can  be 
so  controlled  that  the  finest  precipitates  may 
be  collected  in  thenL  Alundum  extraction 
thimbles  can  be  cleaned  by  simple  ignition. 
An  alundum  cement  is  made  for  lining  crucibles 
and  furnaces ;  it  does  not  melt  or  combine  with 
carbon  below  1 960°.  Alundum  bricks  have  been 
used  in  place  of  silica  for  the  roofs  of  electric 
furnaces  (Saunders,  Amer.  ElectrocheuL  Soc. 
1911;  Met.  and  Chem.  Eng.  1911,  9,  258; 
J.  Soc.  Chem.  Ind.  1911,  30,  686). 

ALUMTTE  or  ALUM -STONE.  Hydrated 
basic  sulphate  of  aluminium  and  potassium 
KA1,(S04).(0H)«,  containing  theoretically  11*4 
p.c.  of  potash.  The  potash  may,  however,  be 
replaced  isomorphously  by  soda  with  a  passage 
from  *  kalioalumte '  to  *  natroalunite '  (Analysis, 
VI).  Further,  the  material  is  often  impure 
owing  to  admixture  with  silica  and  clayey 
matter.  The  mineral  is  usually  found  as  wmte, 
grey,  or  pinkish,  compact  and  granular  masses, 
somewhat  resembling  chalk,  limestone,  or  marble 
in  appearance.  Sp.gr.  2 '58-2 '75.  Occasionally, 
minute  glistening  crystals,  which  belong  to  the 
rhombohedral  system,  are  found  in  cavities  in 
€he  massive  material.  The  foUowinff  analyses 
are  of  material  from  I  and  II  Bullahoelah,  New 


South  Wales  (I  pale  pink,  and  II  chalky  white, 
containing  more  silica) ;  III  and  IV,  Marysvale, 
Utah  (III  of  selected  dear  pink,  transtuoent, 
coarsely  granular  material,  and  IV  of  compact, 
fine-grained,  porcelain-like  material) ;  V,  *  cala- 
fatite  *  from  Benahadaux,  Almeria,  Spain ; 
VI,  white,  chalky  '  natroalunite  *  from  Funeral 
Range,  Death  Valley,  California. 

I.        II.  in.       IV.  V.  VL 

A1,0,  37*52  37*37  3718  84*40  37*98  38*46 

Fe,0,    0*26  0*27  trace  trace  —  — 

K,0       9*51      6*68  10*46      9*71  9*64  1*04 

Na,0      1*12      1*08  0-33      0*66  —  6*83 

SO,      36*76  22*09  38*34  36*54  34*77  25*03 

SiO,       1-92  19*34  0*22      5-28  —  10*27 

PjOj    trace  trace  0*68     0*50  —  — 

HaO      13*19  13*86  12*90  1308  17*61  17*60 

MoistnreO'06  0*46  0*09     Oil  —  — 


100*84  100*16  100*10  100*18  100-00  98*23 

The  mineral  mostly  occurs  in  connection 
with  volcanic  rocks,  having  been  formed  by  the 
action  of  solfataric  vapours  on  such  rocks. 
In  some  cases,  however,  it  may  have  been  formed 
by  the  action  of  decomposing  iron-pyrites  on 
cfav.  Extensive  deposits  have  long  been  known 
at  Tolfa  near  Rome,  Montioni  in  Tuscany,  and 
Musaz  and  Bereghszasz  in  Hungary.  An 
important  deposit,  forming  wide  veins  in  vol- 
canic rock  (andesite  or  dacite),  has  been  dis- 
covered and  mined  near  Maiysvale  in  Utah. 
A  detailed  description  of  this,  tc^ether  with  a 
risumi  of  the  published  descriptions  of  other 
deposits  of  commercial  importance,  has  been 
given  by  B.  S.  Butler  and  H.  S.  Gale  (Bull. 
U.S.  Geol.  Survey,  1912,  No.  611,  pp.  1-64). 
Otiher  localities  are  in  Colorado,  Nevada,  Cali- 
fornia, and  Arizona ;  Kyuquot  Sound,  Vancouver 
Island,  British  Columbia;  Bullahdelah,  60 
miles  north  of  Newcastle,  New  South  Wales; 
Carriokalinsa  Head,  on  St.  Vincent  Gulf,  40 
miles  60UW  of  Adelaide,  South  Australia; 
Wamertown,  near  Port  Pirie,  South  Australia ; 
and  near  Sunbury,  Victoria.  (On  the  Australian 
deposits,  eee  E.  F.  Pittman,  The  Biineral  Re- 
sources of  New  South  Wales,  Dept.  of  Mines, 
N.S.W.,  1901.  The  AluniteDq[>08its  of  Australia 
and  their  Utilisation,  Advisory  Council  oi 
Science  and  Industry,  Commonwealth  of 
Australia,  Bull.  No.  *^3,  Melbourne,  1917.) 
Extensive  deposits  have  also  been  found  near 
Benahadaux,  10  km.  from  the  port  of  Almeria 
in  Spain  (S.  Calderdn,  Los  minerales  de  Espafia, 
1910,  u.  p.  205). 

Since  the  fifteenth  century  this  mineral  has 
been  exploited  at  Tolfa  near  Rome,  for  the 
manufacture  of  potash-alum;  and  the  harder 
and  more  compact  varieties  from  Hungary  have 
been  used  for  millstones.  Now,  however,  the 
mineral  is  of  considerable  importance  as  a  source 
of  potash.  When  ignited,  it  gives  off  all  its 
water  and  three-quarters  of  its  sulphuric  acid, 
there  remaining  alumina  and  potassium  sulphate, 
92  p.c.  of  the  whole  of  the  latter  beinff  capable 
of  extraction  in  solution  by  this  method.  When 
roasted  at  a  lower  temperature,  aluminium  and 
potassium  sulphates  can  be  extracted  by  lixivia- 
tion  and  crystallised  as  potash-alum.  Details 
of  the  methods  of  treating  the  mineral  as 
practiHed  in  Australia  and  Utoh  are  given  in  the 
Bulletins  quoted  above.    The  mineral  may  be 


AMALGAM. 


181 


tiBed  directly  as  an  artifioial  manuro;  but, 
since  the  potash  is  not  present  in  a  solnble 
form,  better  results  are  obtained  by  first  roasting. 

1m  J.  S. 

ALUNOGEN.  Hydrated  aluminium  sulphate 
A1,(S0  Js,18H,0,  ocouning  as  a  white,  delicately 
fibrous  efflorescence  on  shale  and  other  rocks. 
It  has  been  formed  by  the  action  on  the  alu- 
minous rock  of  the  products  of  decomposition 
of  iron-p3nites.  A  trace  of  iron  sulpnate  is 
often  present,  imparting  a  yellowish  or  reddish 
colour  to  the  mineraL  L.  J.  S. 

ALVA  or  ALFA  v.  Esfabto. 

ALVELOS.  A  name  applied  to  the  i?«pAor6ta 
kderodoxa  (Muell.),  growmg  in  Brazil,  the  juice 
of  which  has  be^  used  as  a  cure  for  cancer 
(Pfaann.  J.  [3]  10,  614). 

ALYPOIE.  Trade  name  for  benzoyUdm- 
tneihj^iamitweihyldimeUiylcarbinol  hydrochloride. 

CHs— N(CH,), 

C^,-C— O— C0-O,H, 

I 

CH,— N(CHJ, 

Employed  in  place  of  cocaine  and  stovaine  as 
an  anaesthetic  and  as  a  remedy  for  vomiting 
and  in  the  treatment  of  diHeases  of  the  upper 
respiratory  passages  and  of  the  organ  of  hearing. 
Used  also  m  Yeterinazy  practice  in  place  of 
cocaine. 

It  occurs  in  crystals,  m.p.  169^,  sol.  in 
water,  forming  a  neutral  solution.  Aqueous 
solutions  may  1)0  sterilised  without  undergoing 
decompositioii  by  boiling  from  5  to  10  minutes 
(Neustatter,  Pharm.  J.  1906,  869). 

(For  distinctive  reactions,  v,  Lemaire,  Bep. 
Phann.  1906,  18,  385.)  (v.  Synthstio  dbuos.) 

AMADOU  or  GERMAN  TINDER.  (Anutdai^ 
Fr. ;  Zwtderschwamm,  Get.).  A  spongy  com- 
bustible substance,  prepared  from  a  species  of 
fungofly  Femes  {Poivpanu)  igniaritu,  the  *  falM ' 
tinder-funffus,  which  grows  on  the  trunks  of  the 
oak.  but  sIbo  on  alder,  willow,  and  various  other 
trees.  It  must  be  plucked  in  the  months  of 
August  and  September.  It  may  also  be  pre- 
pared from  Fomee  (Pohpor^)  fomefUarius,  the 
true  tinder-fungus,  also  indigenous,  found 
especiallv  on  the  beech,  elm,  and  various  fruit 
trees.  It  was  formerly  used  in  surgery,  and  has 
hence  been  called  surgeons'  agaric.  Amadou  \a 
prepared  by  removing  the  outer  rind  and  care- 
fully separating  the  yellow- brown  spongy  sub- 
stance which  lies  within  it.  This  substance  is 
cut  into  thin  slices,  and  beaten  with  a  mallet  to 
soften  it,  till  it  can  be  easily  pulled  asunder 
between  the  fingers.  In  this  state  it  is  useful 
in  suzjiery.  To  convert  it  into  tinder,  it  is 
boiled  m  a  strong  solution  of  nitre,  dried,  beaten 
anew,  and  put  a  second  time  into  the  solution. 
Sometimes,  to  render  it  very  inflammable,  it  is 
imbued  with  gunpowder,  whence  the  distinction 
of  '  blaok '  and  *  brown '  amadou. 

AMAUAM.  An  alloy  of  mercury  with  some 
other  metal  or  metals. 

There  are  four  general  methods  for  preparing 
amalgams. 

L  Metallio  mercury  is  brought  into  contact 
with  the  other  metal,  either  in  the  solid  or  in  a 
finely  divided  state  at  the  ordinary  or  at  a 
higher  temperature.  Iii  this  way  amalgams  of 
antimony,   acsenio,   binnuth,   cadmium,    mag- 


nesium,   potassium,  silver,  sodium,  tellurium, 
thorium,  tin,  zinc,  and  lead  may  be  obtained. 

2.  Mercury  is  brought  into  contact  with  a 
saturated  solution  of  a  salt  of  the  metal,  when 
part  of  the  mercury  ^oes  into  solution  and  the 
remainder  combines  with  the  liberated  metal ;  or 
better  still,  zinc  or  sodium  amalgam  is  employed, 
when  the  zinc  or  sodium  displaoes  the  metal  in 
the  solution.  By  this  method  amalgams  of  bis- 
muth, calcium,  chromium,  iridium,  iron,  magne* 
slum,  manganese,  osmium,  palladium,  and  stron- 
tium may  be  prepared  by  using  sodium  amalsam, 
and  coMlt  and  nickel  by  nsing  zinc  ama^am 
(Moissan,  Compt.  rend.  1879 ;  Chem.  News,  39, 
84). 

3.  The  metal  to  be  amalgamated  is  placed  in 
a  solution  of  a  mercury  siut;  copper  may  be 
amalgamated  by  this  process. 

4.  The  metal  is  placed  in  contact  with 
mercury  and  dilute  acid;  this  is  the  method 
usually  employed  in  amalgamating  zinc.  Iron, 
aluminium,  palladium,  nickel,  ima  oobiilt  may 
be  made  to  combine  with  mercunr  by  this  process 
if  they  be  placed  in  contact  with  a  stick  of  zino 
(Gasamajor,  Chem.  News,  34,  36 ;  Aroh.  Pharm. 
[3]  11,  64;  Chem.  Soo.  Trans.  [2]  34,  474). 

Amalgams  are  also  formed  when  mercury  is 
used  as  the  cathode  in  the  electrolysis  of  salt 
solutions;  a  number  of  metals  can  thus  be 
obtained  as  amalgams,  although  they  cannot  be 
obtained  directly  in  the  free  state  by  the  elec- 
troljrsis  of  aqueous  solutions. 

The  combination  of  sodium  with  mercury  by 
method  1  takes  place  with  j^:'cat  energy,  heat 
and  light  being  produced.  The  preparation  is 
best  carried  out  by  combining  a  smalTportion  of 
the  mercury  with  the  sodium,  and  then  adding 
the  remainder  to  the  amalgam. 

Native  amalgams  are  found  in  various  parts 
of  the  world.  The  table  on  next  page  contains 
the  analyses  of  a  few. 

Qold  and  silver  in  the  metckUio  state  can  be 
extracted  from  their  ores  by  grinding  the  ores 
and  making  them  pass  though  mercury, 
although  this  process  is  now  largely  replaced  by 
the  m(xlem  cyaniding  methods.  (For  details,  v, 
these  metals ;  and  May,  J.  Soa  Chem.  Ind.  4, 
352;  Moon,  id.  4,  678;  MUler,  id.  4,  122; 
Whitehead,  id.  4,  503 ;  Fisher  and  Waber,  id. 
i,  351 ;  Barker,  Dingl.  poly.  J.  251,  32 ;  Body, 
id.  252,  33;  MoUoy,  id.  254,  210;  Bonnet,  ici. 
254,  297  ;  Cassel,  id.  257,  286  ;  Jordan,  id.  258, 
163  ;  HoUick,  id.  258, 168.)  When  the  mercury 
has  taken  up  a  quantity  of  gold,  the  amalgam 
is  squeezed  through  chamois  leather,  when  the 
greater  portion  of  the  gold  is  left,  combined 
with  a  little  mercury,  as  a  pasty  mass.  Kazant- 
seff  (Bull.  Soc.  chim.  [2]  30,  20 ;  Chem.  Hoc. 
Trans.  [2]  34,  937)  finds  that  the  mercury  which 
escapes  contains  at  ordinary  temperatures  0*126 

S.c.    of  gold,   at  0^  0*110  p.c.,  and  at    100* 
■650    p.c.,   thus   behaving   like    an    aqueous 
solution. 

Berthelot  found  that  the  solution  of  definite 
amalgams' in  different  quantities  of  mercury,  like 
the  solution  of  salts  in  water,  absorbs  a  constant 
amount  of  heat ;  thus  the  heat  of  solution  of  an 
amalgam  of  which  the  composition  corresponds 
with  the  formula  H^i4K  in  four  times  its  weight 
of  mercury  is  *— 8*0  kil.  dee.  of  heat,  and  in  twenty 
times  —9-0  kil.  deg.  (Compt.  rend.  89,  465; 
Chem.  Soc.  Abstr.  38,  1). 


I8i 


AMALQAlf. 


Ag 

Hg 

Au 

FeaOs 

GaO 

AgGl 

Fe 

018 

Zn 

tr. 

Pb 
tr. 

GaGOs 

Gu 
tr. 

Insol. 
andloBs 

LocaUty 

Analyst  and 
reference 

76*000 

02*464 
86*0 

26*0 
27*6 

46*80 

56-70 

600 

28066 

7*106 
640 

78*8 
72-6 

61*12 

48*27 

60*06 

to 

68*87 

67*40 

80-02 

to 
41*68 
88*80 

0083 

0066 

0-088 

1 

0*21 

0-400 
1*828 

1*01 

Kongsberg, 
Korway. 

Palatinate. 

Allemont, 
Daaphin4. 

Sweden. 

Frledrlchssegen.— 

Mine. 

Mariposa, 
Oalifomia. 

Ohooo, 
NewCteenada. 

FUi^t.  Phil. 

Mag.  [5]  0. 

146. 

Klaproth. 

Urel. 
Heyer.tf. 
CQrdier,A. 

Nordsbrom, 
J.  86.  1,  621. 

Weiss, 
J.  86,  1828; 

Z.8eol. 

Ges.  84,  817. 

Ure. 

Schneider. 
Uie. 

According  to  Berthelot,  the  maximum  iieats 
of  formation  for  amalgams  of  potassium  and 
sodium  are  34*2  and  21*1,  corresponding  with 
oiystalline  amalgams  containing  1*6  p.c.  of 
potassinm,  and  2  p.o.  of  sodium  respectively. 
In  these  amalgams  the  relative  affinities  of  the 
free  alkali  metals  are  inverted :  this  explains 
Kraut's  and  Popp's  observation  that  sodium 
displaoes  potassium  when  potassium  hydroxide 
is  treated  with  sodium  amalgam,  the  final  result 
being  the  formation  of  an  amalgam  of  composi- 
tion Hg.^Na  (Compt  rend.  88,  1336). 

The  views  formerly  held  on  the  constitation 
of  amalgams  and  particularly  on  the  existence  of 
definite  amakams  of  the  nature  of  chemical 
compounds  ofmerctiry  and  the  alloyed  metal, 
have  been  profoundly  modified  by  the  study  of 
these  bodies  by  the  methods  of  metallography 
(v.  Mxtalloobafhy).  The  amalgams  are  found 
to  be  strictly  analogous  to  other  alloys,  but  their 
peeuliar  behaviour  arises  from  the  fact  that  they 
are  frequently  met  with  in  a  range  of  temperature 
which  lies  between  the  commencement  of  solidifi- 
cation and  final  complete  crystallisation.  It  has 
been  shown  that  a  number  of  supposed  com- 
pounds, of  which  the  existence  had  been  assumed 
on  the  ground  that  amalgams  representing  them 
took  the  form  of  homogeneous  crystalline  bodies, 
are  not  true  compounds,  whilst  definite  com- 
pounds of  different  composition  have  been 
found.  Thus,  in  the  case  of  sodium  and 
potassium  amalgams,  the  compounds  Hg^Na, 
Hg,Na,  HgNa,  BtajNa^  Hg^a,,  HgNa„  and 
Bgfi,  HgK,  HgX  Hg,K„  and  Hg.K,  have 
been  recognised  (SchuUer,  Zeitsoh.  anorg.  Chem. 
1904,  40,  385 ;  Kumakoff,  ibid.  1900,  23,  439 ; 
Jaeneoke,  Zeitsch.  physical.  Chem.  1907,  58, 
246). 

The  amalgams  of  bismuth,  zinc,  tin,  and 
thallium  are  found  not  to  contain  any  definite 
compounds  (Pushin,  Zeiteoh.  anorg.  Chem.  1903, 
36, 201 :  Heteren,  ibid.  1904, 42, 129 ;  Kumakoff 
and  Pushin,  ibid.  1903,  30,  86). 

*  Ammonium  amalgam  '  is  prepared  by  acting 
on  a  saturated  solution  of  ammonium  chloride 
with  sodium  amalgam ;  the  amalgam  thus  ob- 
tained soon  breaks  up  into  mercury,  and  ammonia 
and  hydrogen  sases.  According  to  WetheriU 
(Amer.  J.  ScL  |2]  60,  160),  this  compound  is 
not  a  true  amaJgam,  aa  when  an  ammoniacal 
solution  is  electrolysed,  the  n^ative  pole  being 


a  spongy  plate  impr^nated  with  mercury,  no 
amalgam  is  formed.  £andolt  (Zeiteoh.  t  Chem. 
[2]  5,  429)  draws  attention  to  the  fact  that  am- 
monium amalgam  does  not  reduce  solutions  of 
silver  nitrate,  ferric  chloride,  or  cuprio  sulphate, 
as  do  sodium  and  potassium  atn^lgnma 

Seeley  (Chem.  News,  21,  265)  has  shown  that 
on  submitting;  ammonium  amalgam  to  pressure, 
its  volume  diminishes  in  the  same  way  as  does 
that  of  a  gas,  and  henoe  he  considers  that  the 
ammonia  and  hydrogen  exist  in  the  «.malga.m  as 
gas,  and  that  the  spongy  mass  is  only  a  froth  of 
mercury  enclosing  these  gases. 

Gellatlin  (Zeitsch.  f.  Chem.  [2]  6,  607)  asserts 
that  when  ammonium  amalgam,  free  from 
sodium,  is  placed  in  contact  with  phosphorus, 
phosphoretted  hydrogen  is  evolved,  and  he 
mfers  that  the  hydrogen  must  be  in  the  nascent 
state. 

Pfeil  and  Lippmann  (C!ompt.  rend.  62,  426) 
state  that  trimethylamine  hydrochloride  also 
forms  a  spongy  amalgam  which  quickly  decom- 
poses witn  evolution  of  hydrogen  and  formation 
of  trimethylamine;  saturated  solutions  of  the 
hydrochlorides  of  aniline,  coniine,  morphine, 
and  quinine  give  off  hydrc^n  only. 

Ebetrleal  ainalgmin  is  made  by  meltmg  to- 
gether 1  part  of  zinc  and  1  part  of  tin,  and  then 
adding  3  parts  of  mercury.  An  amalgam  of 
cadmium  is  used  in  the  construction  of  the 
cadmium  standard  cell;  this  amalgam  and  its 
electrical  behaviour  have  been  studied  by  F.  £. 
Smith  (PhiL  Mag.  Februanr,  1910). 

Silvering  amalgams.  For  metals,  1  part  of 
silver  to  8  parts  of  mercury ;  for  glass,  1  part 
eaoh  of  lead  and  tin,  2  parts  bismuth,  and  4  parts 
mercury.  The  use  of  amalgams  for  silvering  has 
been  almost  completely  superseded  by  the  use — ^in 
the  case  of  glass->of  uiemioaUy  deposited  silver, 
and  in  the  case  of  metals  by  electro-plating. 

Teeth  fillings.  1.  (copper  precipitated  from 
copper  sulphate  solution  with  zinc,  washed.with 
sulphuric  acid  containing  a  small  quantity  of 
mercuric  nitrate,  and  amalgamated  with  twice 
its  weight  of  mercury  (Fletcher),  has  the  pro- 
perty of  softening  with  heat  and  hardening  again 
after  a  few  hours.  It  is  a  permanent  filling,  as 
the  copper  salts  penetiate  and  preserve  the  tooth 
substance.  It  has  the  objection  of  staining  the 
tooth,  and  is  only  used  in  posterior  teeth.  2.  A 
palladium  amalgam  is  sometimes  employed,  but 


AMBSa 


183 


ita  rapidity  of  Betting,  intense  black  colour,  and 
cost  are  against  its  general  use.  3.  An  alloy  oi 
silver  68-5,  tin  25*6,  gold  5,  and  zino  1  p.o. 
(Black);  or  silver  69o»  tin  26*6,  gold  4,  and 
dno  1  p.o.  (Tolloch),  amalgamated  with  mer- 
cury, is  extensively  employed,  as  it  has  a  good 
edge  strength,  and  suffers  little,  if  any,  shrinkage. 
The  shrinkage  is  the  greatest  difficulty  to  over- 
come in  order  to  render  alloys  of  permanent  use 
for  teeth  fillins,  the  object  being  to  secure  such 
a  proportion  (3  metals  that  the  shrinkage  of  one 
may  be  overcome  by  the  expansion  of  another, 
and  BO  obtain  a  watertight  plug.  W.  R. 

AHALIO  ACID  v.  Alloxantiv. 

AMANITA  MUSCARIA.  Fly  agaric  A 
poisonous  fnngua,  used  in  Kamtschatka  and 
Siberia  as  a  narootic  and  intoxicant,  and,  when 
steeped  in  milk,  as  a  fly-poison.  A  narcotic 
organic  base,  mtaearine  CsH^gNOj,  which  is  the 
hydrated  aldehyde  of  betaine.  has  been  isolated 
from  it  (Schmiedeberg  and  Hamack,  J.  1876, 804). 

The  natural  muscarine  is  like  the  artificial 
product  in  crystalline  form,  solubilitv,  and 
composition  of  its  platino-  and  auro-chlorides, 
and  to  a  large  extent  in  its  physiological  action, 
but  unlike  the  artificial  muscarine  it  does  not 
induce  paral^-sis  of  the  intermuscular  nerve- 
terminations  m  the  froe,  and  myosis  in  the  pupils 
of  the  eyes  of  birds  (Nothnagel,  Ber.  26,  801). 
It  differs  both  in  constitution  and  properties 
from  anhydro-  and  Mo-muscarine. 

A  ereen  and  red  dye  of  composition 
GjyHipO.^  and  C^^^fi^  respectively,  have  also 
been  isolated  from  it  (Griffiths,  Compt.  rend. 
130,  42). 

AMARANTH  v.  Azo-  ooLOinuNO  uattbbs. 

AH ARIN.  Trade  name  for  triphenyldihydro- 
glyozaline. 

AMATOL.  A  mixture  of  80  parts  of  ammo- 
nium nitrate  with  20  parts  of  trinitrotoluene 
(T.N.T.).  Used  as  an  explosive.  See  Explo- 
sives. 

AMAZON-STONE.  A  bright-creen  variety  of 
the  potash-felspar  microcline  (KAlSisOg).  It  is 
found  in  granitic  rocks  near  Lake  Ilmen  in  the 
Ural  Mountains,  at  Pike's  Peak  in  Colorado, 
and  of  very  good  quality  in  Madagascar.  It 
is  used  to  a  limited  extent  as  a  gem-stone,  and 
for  TWAlcmg  various  small  ornamental  objects 

(9,  PSLSFAB).  L.  J.  S. 

AMBAR  UQUID  v.  Balsams. 

AMBATOARINITE  v,  Ancylitb. 

AMBER  or  SUCCINITE.  {Bemdein,  Ger.)  A 
fbssQ  resin  derived  from  the  extinct  conifer 
PinUeswceinifer  ((Joppert),  andfound  asirreffular 
nodules  in  strata  of  Tertiary  age,  principal^  on 
the  Prussian  coast  of  the  Baltic.  The  amber- 
bearinff  stratum  lies  partly  below  sea-level,  and 
the  amoer  washed  out  by  the  action  of  the  waves 
is  picked  up  on  the  sea-shore  or  won  by  dredging. 
Such  'strand-amber'  was  formerly  collected 
farther  west*  as  far  as  the  coast  of  I^Uand,  and 
isolated  specimens  are  picked  up  on  the  east 
coast  of  £axgland  (Norfolk,  Suffolk,  and  Essex). 
At  the  present  time  the  bulk  of  Prussian  or 
Baltic  amber  is  obtained  from  pits  and  mines  in 
the  *  blue  earth '  in  Samland,  East  Prussia. 
Here  the  production  in  1907  amounted  to 
404,300  kilos,  and  in  addition  about  20,000 
kQos  was  collected  on  the  sea-shore. 

Baltic  amber  differs  from  other  fossil  resios 
in  containing  succinic  acid,  which  is  present  to 
the  extent  of  3  to  4  p.o.  in  perfectly  transparent 


specimens,  but  reaching  8  p.o.  in  cloudy 
(frothy  ')  amber.  It  is  Sierefore  distinffuished 
by  the  mineralogical  name  succinite^  and  in  the 
trade  the  tendency  is  to  apply  the  name  *  amber  * 
exolusivelv  to  Baltic  amoer.  The  composition 
is  somewnat  variable,  averaging  C,  70  p.c. ; 
0,  10*6  p.o. ;  H,  10'5  p.c. ;  and  corresponding 
approximately  with  the  formula  C|oH,«0. 
Sulphur  is  also  present  (0*26  to  0*42  p.c.),  and 
some  ash,  usualiv  about  0*2  p.c.,  but  increas- 
ing in  amount  it  the  material  encloses  foreign 
matter.  Amber  is,  however,,  not  a  simple 
resin ;  when  heated,  it  sives  oil  of  amber  {q,v.) 
and  other  products,  and  by  the  action  of  solvents 
at  least  four  different  kinds  of  resin  can  be  ex- 
tracted from  it.  According  to  0.  Helm,  Baltic 
amber  contains  17  to  22  p.c.  of  a  resin  (m.p.  106°) 
Boluble  in  alcohol ;  6  to  6  p.c.  of  a  resin  (m.p. 
145°)  insoluble  in  alcohol,  but  soluble  in  ether ; 
7  to  9  p.o.  of  a  resin  (m.p.  175°)  insoluble  in 
alcohol  and  ether,  but  <ussolving  in  caustic 
potash ;  and  44  to  60  p.c.  of  insoluble 
bitumen. 

Baltic  amber  is  usually  pale  yellow,  ranging 
to  brown  or  reddish-brown  in  colour,  and  it 
I  varies  from  perfect  transparency  to  opacity. 
I  The  varyine  degrees  of  turbidity  are  due  to  Uie 
presence  of  vast  numbers  of  microscopic  air- 
I  bubbles.  The  enclosure  of  insects  and  fragments 
'  of  wood  and  dirt  in  amber  is  well  known,  and 
I  points  at  once  to  the  mode  of  origin  of  the 
!  material.  According  to  differences  in  colour  and 
transparency,  various  trade  names  are  applied, 
such  as  *  dear,'  '  flohmis,'  *  cloudy,'  *  bastard,' 
*  osseous '  or  '  bone,'  and  *  frothy.'  The  sp.ffr. 
ranges  from  1-05  to  1*10  (varving  with  Uie 
porosity) ;  and  the  hardness  is  2|,  Ming  rather 
higher  than  that  of  most  other  resins,  which 
latter  can  be  scratched  with  the  finger-naiL 
The  material  is  brittle  and  breaks  with  a  oon- 
choidal  fracture.  When  out  with  a  knife, 
parings  are  not  obtained,  but  only  powder.  It 
can  w  turned  on  the  lathe  and  takes  a  good 
polish,  being  worked  with  whiting  and  water  or 
rotten-stone  and  oil,  iind  finished  by  friction  with 
a  flanneL  When  heated,  amber  begins  to  soften 
at  about  150^,  giving  a  charactOTistic  odour ; 
it  melts  at  350''-375^  that  is,  at  a  higher 
temperature  than  other  resins,  giving  dense  mate 
fames  with  a  peculiar  aromatic  odour,  and 
causing  violent  coughing.  When  rubbed  it 
becomes  negatively  eleotrmed  (from  the  ancient 
name  electron,  for  amber,  the  word  '  electricity ' 
is  derived) ;  and  when  rubbed  vigorously  it  emits 
an  aromatic  odour,  but  does  not  become  sticky 
like  other  resins.  These  characters  serve  to 
distinguish  true  amber  from  the  more  abundant 
copal;  the  latter  is  further  usually  clearer, 
lignter  in  colour,  and  more  gummy  in  appear- 
ance. 

In  the  trade  the  material  is  sorted  into  many 
grades  suited  for  various  purposes.  The  larger 
pieces  of  better  quality  (work-stone')  are  cut 
mto  beads  and  other  small  personal  ornaments, 
and  are  largely  used  for  making  the  mouth- 

Eieces  of  tobacco-pipes  and  cigar-  and  cigarette- 
olders.  Smaller  and  impure  fn^ments 
('  varnish ')  are  melted  down  for  the  manufac- 
ture of  amber  varnish  and  lac ;  but  in  recent 
years  such  material  is  laigely  converted  by  the 
application  of  heat  and  hydraulic  pressure  into 
blocks  of  press&i  amber  or  *  ambroid.'  About 
35,000  kilos  of  pressed  amber  is  now  produced 


184 


AMBER. 


annually  from  three  times  the  amount  of  rough 
amber ;  it  is  cut  for  ornaments  and  smokers* 
mouth-pieces.  Prices  (current  in  1908)  for 
rouflh  *  work-stone  *  vary,  according  to  size  and 
quMity,  from  III.  to  10«.  per  kilo,  and  for 
smaller,  inferior  material  (*  varnish  *)  about  6«. 
per  kilo.  Pressed  amber  fetches  41.  to  5{.  per 
kilo.  The  production  and  the  trade  in  amber, 
as  well  as  the  literature  of  the  subject,  is  almost 
exclusively  German,  though  the  finished  articles 
are  largely  made  in  Vienna. 

Other  varieties  of  fossil  resin  olos^  allied 
to  amber,  but  regarded  as  distinct  from  Prussian 
or  Baltic  amber  (snooinite),  are  the  following  : — 

BeckerUe  (£.  Pieszczek,  1880),  a  black  resin 
occurring  witii  Prussian  amber. 

Burmite,  Birmite,  or  Burmese  amber  (F. 
Noetling,  1893),  a  dark  reddish-bi^wn,  amber- 
like resin,  which  has  long  been  mined  in  Upper 
Burma  and  used  in  China.  It  is  found  in  large 
masses,  one  seen  by  the  writer  weighing  33}  lbs., 
whilst  the  largest  piece  of  Prussian  amb^  yet 
found  weighs  only  9*7  kilos  (21)  lbs.). 

Chemarviniie  (B.  J.  Harrington,  1891), 
Cedarite  (B.  Klebs,  1897),  or  Canadian  amber, 
found  as  pale  yellow  fragments  the  size  of  a  pea 
to  that  of  a  walnut  on  the  beach  of  Cedar  Lake, 
near  Chemahawin  in  Saskatchewan. 

DeUUynite  (J.  Niedzwiedzki,  1908),  from 
Delatyn  in  the  Galician  Carpathians,  differs 
from  succinite  ifi  containing  rather  more  carbon 
(79*93  p.c.),  less  succinic  acid  (0*74-1*67  p.c.), 
and  no  sulphur. 

OedriU  (0.  Helm,  1878),  a  bright,  pale  yellow 
resin  found  with  Prussian  amber,  but  differing 
from  this  in  containing  less  oxygen  and  no 
succinic  acid ;  m.p.  140°. 

OkssiU  (O.  Hekn,  1881),  also  found  with 
Prussian  amber;  it  contains  no  succinic  acid, 
but  probably  some  formic  acid;  nLp.  200°. 

iCoumantte,  Romanite,  Rumanite,  or  Rou- 
manian amber  (0.  Helm,  1891),  a  browmsh.- 
yellow  to  brown  resin,  found  in  Tertiary  sand- 
stone at  several  places  in  Roumania;  it  re- 
sembles Prussian  amber  in  containing  some 
succinic  acid  (0*3-3*2  p.c.),  and  is  characterised 
by  the  relatively  large  amount  of  sulphur 
(1*16  p.c.);  m.p.  300°. 

Simetile,  or  Sicilian  amber  .(0.  Helm  and  H. 
Conwentz,  1886),  a  clear  wine-red  to  garnet-red 
resin,  remarkable  for  its  beautiful  green  or  blue 
fluorescence,  found  in  the  river  Simeto  and  other 
parts  of  Sicily.  It  contains  only  0*4  p.c.  of 
succinic  acid. 

Siantienite  (E.  Pieszczek,  1880),  a  brown 
resin  occurring  with  Prussian  amber. 

For  sevenu  papers  on  amber  and  amber-like 
resins,  by  O.  Helm  and  by  P.  Dahms,  see  Schr. 
natf.  Qes.  Danzig,  vols,  iv-xii  (1878-1908). 
See  also  Max  Bauer,  Edelsteinkunde,  2nd  edit. 
1909,  and  English  transl.  (Precious  Stones),  by 
L.  J.  Spencer,  1904.  L.  J.  S. 

AMBER,  OIL  OF.  WKen  amber  is  heated 
it  softens,  fuses,  and  gives  off  succinic  acid,  water, 
oil,  and  a  combustible  gas.  If  the  residue 
(colophony  of  amber)  be  more  strongly  heated, 
a  colourless  oil  passes  over.  These  oils,  accord- 
ing to  Pelletier  and  Walter  (Ann.  Chem.  Phys. 
[3 Jo,  89),  have  the  composition  of  oil  of  turpen- 
tine. B^  distilling  witb  water,  a  pale-yellow 
oil,  having  a  strong  odour  and  acrid  taste, 
can  be  obtained.    It  blackens  and  thickens  on 


exposure  to  air  and  heat,  boils  at  86°,  and  has 
a  sp.gr.  of  0  '758  at  24°.  One  part  of  the  rectified 
oil  mixed  with  24  parts  of  idoohol  (0*830)  and 
96  of  ammonia,  forms  eau  de  luce,  a  cdebrated 
old  perfume.  By  mixing  *  eau  de  luce '  with 
nitric  acid,  artificial  musk  is  made.  Its  solution 
in  alcohol  was  formerly  considered  as  a  specific 
for  whooping-cough  (v.  also  Oils,  Essential, 
and  Resiks). 

AMBER  VARNISH  v.  Vaskish. 

AMBERGRIS.  {Ambergris,  Fr. ;  Ambra,  Am- 
bar,  Ger.)  (J.  Soc.  Chem.  Ind.  1890,  429.)  Is 
found  in  the  sea,  near  the  coasts  of  tropical 
countries,  and  as  a  morbid  product  in  the 
intestines  of  the  cachalot  or  sperm  whale 
{Physeier  macrocephalus). 

Ambeowris  is  generally  found  in  fragments, 
but  pieces  nave  b^n  obtiuned  weighing  upwards 
of  270  lbs.  Its  sp.gr.  ranges  fiom  0*780  to 
0*926  (0*780  to  0*896  Brande,  0*908  to  0*920 
Pereira).  If  of  good  quality,  it  adheres  like 
wax  to  the  edge  of  a  knife  with  which  it  is 
scraped,  retains  the  impression  of  the  nails,  and 
emits  a  fat  odoriferous  liquid  on  being  penetrated 
with  a  hot  needle.  It  is  generally  brittle,  but 
on  rubbing  it  with  the  nad  it  becomes  smooth 
like  hard  soap.  Its  colour  varies  bom  black 
to  white.  Its  smell  is  peculiar,  and  not  easily 
counterfeited.  It  melts  at  62*2°,  at  100°  it 
is  volatilised  as  a  white  vapour ;  on  a  red-hot 
coal  it  bums  and  is  entirely  dissipated.  Water 
has  no  action  on  it ;  acids,  except  nitric  acid, 
act  feebly  upon  it ;  ether  and  the  volatile  oils 
dissolve  it;  so  do  the  fixed  oils,  and  also 
ammonia  when  assisted  by  heat;  alcohol 
dissolves  a  portion  of  it. 

The  principal  constituent  of  ambergris  is 
ambrein  {q,v.) ;  its  inorganic  constituents  are 
carbonate  and  phosphate  of  calcium,  with 
traces  of  ferric  oxide  and  alkaline  chlorides. 

Used  by  perfumers.  The  Chinese  test  its 
purity  by  scraping  it  upon  boiling  tea,  in  which 
it  should  whol^  melt. 

AMBERITE  v.  Explosives. 

AMBLTGONITE.  Fluo-phosphate  of  alu- 
minium  and  lithium  AlP(j4,LiF,  crystallising 
in  the  anorthic  system.  It  is  usually  found  as 
whitish  cleavage  masses  much  resembling  felspar 
in  appearance,  from  which  it  is  distinguished  by 
its  nigher  sp.gr.  3*01-3*09  and  chemical  cha- 
racters. It  occurs  in  granitic  rocks  at  Montebras 
in  France,  Cdcares  in  Spain  (with  tin  ore),  Pala 
in  California,  &c.  At  each  of  the  places  named 
it  has  been  mined  for  the  preparation  of  lithium 
salts,  the  phosphate  beins  a  by-product.  It 
contains  about  10  p.c.  of  uthia.  A  variety  in 
which  the  lithium  ia  largely  replaced  by  sodium 
has  been  found  as  greyish- white  cleavage-masses 
in  pegmatite  near  Canyon  City  in  Fremont  Co., 
Colorado,  and  named  natramblyffonite  or 
fremontite.  In  another  variety,  known  aa 
montebrasite  from  Montebras  in  France,  hydr- 
oxyl  largely  replaces  the  fluorine.  The  general 
formula  for  the  mineral  is  then 

(Li,Na)Al(F,0fi)P04 

L.  J.  S. 
AMBRiODI.  {Ambreine,  Fr. ;  Ambarstoff, 
Ger.)  Isolated  by  Pelletier  and  Caventoo,  by 
digesting  ambergris  in  hot  alcohol,  6p.gr.  0*827. 
Ambrein  C.,H«oO,  purified  by  repeated  crys- 
tallisations from  alcohol,  is  ar  wnite  solid,  sepaia- 


AMINEa 


185 


tiag  in  slender  needles,  m.p.  82^,  which  exhibit 
thfi  phenomenon  of  superrasion  for  a  long  time 
even  if  sown  with  ciystalB.  When  warm  and 
drv,  it  becomes  highly  electrified  on  slight 
ruobing.  It  has  no  optical  activity,  and  is  a 
neutral  substance,  insoluble  in  water,  but 
soluble  in  most  oiganic  solvents,  from  which  it 
does  not  crystallise  out  at  all  readily.  When 
acted  on  by  bromine  in  carbon  tetoachloride 
solution,  it  gives  an  ockbronuh  derivative 
CsyHjsOBr,,  a  white  vitreous  soUd.  Chlorine, 
under  similar  conditions,  decomposes  it.  On 
warming  ambrein  with  phospnorus  penta- 
chloride,  a  white,  amorphous  mass  of  pentachhro- 
ambrein  C„H,sO01s  is  obtained  (RilMui,  Compt. 
lend.  1912,  154,  1729). 

AKBRITE.  A  brown  translucent  resin, 
similar  to  retinite,  found  in  association  with 
New  Zealand  coal  (v.  Resins). 

AMEISlllK  l^rade  name  for  aluminium 
formate. 

AMJENTL.  Trade  name  for  the  hydrochlo- 
ride  of  methyl  hydrastimide.  Forms  yellowish 
needles,  m.p.  227^.  Soluble  in  hot  water  or 
alcohol. 

AHBRICAM  COW  or  MILK  TREE  WAX 
9.  Wax. 

AMBRICAW  ELEMI  v.  Oleo-besins. 

AMBIHT8T.  A  purple  transparent  variety 
of  crystaUised  quartz  (oiO,),  used  as  a  gem- 
stone.  So  named,  from  afi4$v<rT0Sf  'niot  drunken,' 
owing  to  the  ancient  belief  that  the  stone  when 
worn  as  a  charm  prevented  intoxication  {v. 
QtTABTZ).  L.  J.  S. 

AMETHYST.  Tetramethyl  safranine  and 
tetraamyl  safranine  are  found  in  commerce 
under  this  name  (v.  Azmss). 

AMEIUYST,  ORIEHTAL,  v.  Cobundum. 

AMIANTHUS  {Amiante,  Fr.)  Mtmniain 
fax  {v.  Asbestos) 

AMIDASE  V.  Enzymes. 

AMIDATION.  The  operation  of  introducing 
the  amino  group  NH„  as  in  the  production  of 
aniline  from  mtrobenzene  by  means  of  iron 
and  hydrochloric  acid. 

AMIDE  POWDER.  An  e^losive  similar  to 
ordinary  gunpowder,  in  which,  in  place  of  the 
sulphur,  an  ammonium  salt  is  employed  in 
combination  with  saltpetre,  in  such  proportions 
that  on  ignition  potaasamide,  volatile  at  hiffh 
temperatures,  is  formed.  This  increases  tne 
useful  effect  of  the  explosive,  which  bums  with- 
out residue  (Gaens,  Enti;.  Pat.  14412,  1886; 
J.  Soc.  Chem.  Ind.  5,  678). 

AMIDIME8.  Compounds  containing  ami- 
dogen  and  imidogen  attached  to  the  same  carbon 
atom,  «.g.  acetamidine  CH,'0(NH)NH, ;  henz- 
amidine  Cfifi(SK)KEi,  They  are  formed  by 
the  action  of  amines  on  thio-  amides  or  nitriles, 
or  on  the  products  formed  by  acting  on  the 
amides  with  phosphorus  pentachloricfe,  or  by 
treating  the  cyanamides  with  the  Qrignard 
reagent  (Adams  and  Beebe,  J.  Amer.  Chem.  Soc. 
1916,  38,  2768). 

AMIDOAZOBENZEHE   or   AMIUNE   YEL- 

JJOW  V.  AZO-  COLOUBINO  HATTEBS. 

AMIDOGENE.  An  explosive  made  by  dis- 
solving 73  parts  of  potassium  nitrate  and  1  part 
magnesium  sulphate  in  one-third  their  weight  of 
boinng  water ;  8  parts  of  ground  wood  charcoal, 
8  parts  of  bran,  and  10  parts  of  sulphur  are  added, 
and  the  whole  is  digested  for  two  hours  at  140°  ; 


it  is  then  dried  at  50°  and  made  into  cartridges 
(Gemperle,  J.  Soc.  Chem.  Ind.  3,  191 ;  1,  201 ; 
Biedermann*s  Chem.  Tech.  Jahrb.  7,  146). 

AMIDOOUANIDINE  v.  Hydbazines. 

AMIDOL.    Trade   name   for   2 : 4-diamino- 

Shenol  hydbrochloride,  used  as  a  photographic 
evelqper.         

AMIDOHAPHTHOLS    v.    Azo-    coLOUBiNa 

MATTKBS 

AMIDONAPHTHOPHENAZINE  v.  Azines. 
AMIDOPHENOPHENAIITHRAZINE  v. 

AziNES. 

AMIDOPYRINE  (Pyramidon),  Trade  names 
for  4-dimethyiamino  antipyrine. 

yC,H, 

CH,— n/\)0 

CH,-0! IC— N(CH,),   . 

Prepared  by  treating  an  acid  solution  of  antl- 
pyrme  with  sodium  mtrite,  reducing  the  nitroso- 
antipyrine  to  amino-antipyrine,  condensing  with 
benzudehyde,  and  decomposing  the  benzylidene 
derivative  with  hydrochloric  acid.  The  product 
on  methylation  jrields  amidopyrine. 

AMINES,  .^ines  or  '  ammonia  bases '  may 
be  regarded  as  substances  derived  from  am- 
monia by  the  substitution  of  hydrocarbon  radicals 
for  hydrogen.  They  may  also  be  looked  upon  as 
derived  from  hydrocarbons  by  the  replacement 
of  one  or  more  hydrogen  atoms  by  NH,  or  its 
alkyl  substitution  products  NHB  or  NRR'. 
The  definition  of  the  term  may  be  taken  to  in- 
clude alkyl  derivatives  of  hydrazine  and  hydra- 
zoic  acid,  and  compounds  such  as  nitrosamines 
diazo-compounds ;  also  others  which  contain 
nitrogen  miked  to  nitrogen  or  elements  other 
than  carbon,  as  well  as  to  alkyl-  residues.  It 
also  indudes  compounds  in  wmch  the  nitrogen 
forms  part  of  a  ring,  as  in  pyridine,  pyrrol,  and 
their  derivatives,  amoiur  wnich  the  alkaloids 
may  be  mentioned.  The  majority  of  these 
more  complex  substances  are  treated  of  in 
detiul    in    special    articles    (see    arts.    Azo- 

COLOUBINO     MATTEBS ;      AziNES  ;     BONE     OIL ; 

QniNOUNE,  &c.),  and  come  within  the  scope  of 
this  only  in  so  far  as  they  possess  the  general 
characteristics  of  the  ammonia  bases. 

Amines  are  classed  as  primary,  secondarv,  or 
tertiary,  according  as  one,  two,  or  three  of  the 
hydroffen  atoms  of  ammonia  have  been  replaced 
by  aJkyl  or  aryl  groups.  Thus  the  general 
formula  of  the  primary  amines  is  NH^B,  of  the 
secondary  amines  NHBR',  and  of  the  tertiary 
amines  NRR'R",  where  R,  R',  and  R"  may  be 
identical  or  represent  different  radicals.  The 
reactions  of  the  amines  differ  to  some  ex- 
tent according  as  the  substituting  radicals  are 
(1)  all  aliphatic ;  (2)  mixed  aliphatic  and  aro- 
matic, with  the  nitrogen  attached  to  the  aliphatic 
residue,  as  in  benzy&mine ;  (3)  mixed  aliphatio 
and  aromatic,  with  the  nitrogen  attachea  to  a 
carbon  atom  of  the  benzene  ring,  as  in  methyl 
aniline ;  and  (4)  pure  aromatic  amines  such  as 
aniUne  itself,  di-  and  tri-phenylamine,  and  their 
homologues.  Substances  of  groups  (1)  and  (2)  will 
be  refmed  to  here  as  aliphatic  and  aromatic 
amines  respectively,  and  those  of  groups  (3)  and 
(4)  as  aromatic  amino-  compounds.  Aromatic 
amino-  compounds  serve  as  the  starting  materials 
in  many  of  the  different  branches  of  the  dyeing 
industry,  and  are  prepared  artificially  in  large 


186 


AMINES 


quantities  {see  arts.  Akiliki  ;  Azo-  colouring 

ICATTBBS ;        TbIPHENYLUBTHAKB       COLOU&IKO 
HATTERS  ;   DiPHENYLAMINB,  &0.). 

With  the  important  exception  of  the  vege- 
table alkaloids,  the  amines  are  not  widely 
distributed  in  nature,  though  some  of  the  lower 
members  of  the  fatty  series  (methylamines) 
occur  in  plants  and  in  tne  blood  of  some  animals. 
They  are,  however,  found  as  decomposition 
products  of  animal  and  vegetable  organisms, 
and  of  mineral  substances.  Thus  the  methyl- 
amines  are  found  in  herring  brine  and  in  decom- 
posing fish.  Others,  chiefly  diamines,  are  found 
m  certain  pathological-  conditions  of  the  urine. 
Slid  aa  decomposition  products  of  the  animal 
tissues  (ptomaines).  The  decomposition  of 
proteins  gives  rise  to  large  numbers  of  amino- 
acids.  Aniline  was  first  isolated  as  a  product 
of  the  distillation  of  indigo,  and  it  and  its 
homologues  as  well  as  other  bases  are  present 
in  the  distillates  from  bone  oil  (Dippers  oil), 
and  of  coal  tar.  A  mixture  of  fatty  amines  is 
obtained  in  the  dry  distillation  of  the  residues 
in  the  beet-sugar  industry,  and  this,  under  the 
name  of  *  trimethylamine,'  of  which  it  contains 
about  6  p.c.,  is  used  in  France  for  the  preparation 
for  industrial  purposes  of  methyl  cmonde ;  on 
account  of  the  greater  solubility  of  its  hydro- 
chloride, it  has  auo  been  used  instead  of  ammonia 
in  the  preparation  of  potassium  carbonate,  in  a 
maimer  aiukloffous  to  Uie  Solvay  method  for  the 

§  reparation  of  sodium  carbonate,  but  the  process 
oes   not   seem    to   have    been    commercially 
successful. 

Oeneral  methods  of  preparation, 

1.  By  action  of  ammonia  or  its  alkyl  deriva- 
tives on  substitution  products  (generally  haloid 
or  hydroxyl  derivatives)  of  hydrocarbons. 

The  method  first  described  by  Hofmann 
(Phil.  Trans.  1860, 1, 93  ;  1851, 2, 357),  of  heating 
alkyl  halides  (ptreferably  bromides  or  iodides) 
with  ammonia,  is  available  for  the  preparation 
of  primary,  secondaiy,  and  tertiaiy  amines  of 
the  fatty  series,  and  if  aniline  is  substituted  for 
ammonia,  for  the  preparation  of  secondary, 
tertiary,  and  aromatic  amino-  compounds. 
Quaternary  ammonium  compounds  are  also 
formed  in  the  reactions,  which  may  be  repre- 
sented as  follows : — 


NH,  +  RBr 

NH,R  +  R'Br 

NHRR'  +  R"Br 

NRR'R"  4-  R'"Br 


NHjRHBr 
NHRR'HBr 
NRRlf'-HBr 
NRR'R"R'"Br 


The  reaction  will  take  place,  though  only  very 
slowly,  in  aqueous  solution,  more  quickly  in  alco- 
holic solution,  and  best  on  heating  in  alcoholic 
solution  in  sealed  tubes  at  100°.  The  products 
obtained  may  contain  haloid  salts  of  one  or  all 
of  the  possible  amines,  and  of  the  quaternary 
bases,  and  the  proportions  vary  witn  the  con- 
ditions of  experiment  (Werner,  Chem.  Soc,  Trans. 
1918,  113,  899 ;  1919,  115,  1010).  On  distilline 
the  product  with  excess  of  alkali  a  mixture  m. 
the  Ukree  amines  is  obtained  ;  the  three  amines 
may  be  separated  from  the  mixture  by  making 
use  of  their  different  modes  of  reaction  with 
oxalic  ester,  the  chlorides  of  aromatic  sulphonic 
acids,  Grignard*B  reagent,  acetic  anhydride,  or 
acetyl  chforide,  which  are  dealt  with  below. 
The  three  ethyl  amines  have  been  separated  by 


fractional  distillation  (Gamer  and  Tyrer,  Chem. 
Soc.  Trans.  1916,  109,  174.  Cf.  also  Price,  J. 
Soc.  Chem.  Ind.  1918,  37,  82. 

In  the  preparation  on  the  large  scale  of 
secondary  and  tertiary  aromatic  amino-  oom- 
pounds,  e.g.  dimethylaniline,  the  primary  amine 
IS  heated  under'  pressure  directly  with  the 
alcohol  and  hydrochloric  or  sulphuric  acid  at 
180°-200*'.  Here  the  alkyl  group  is  exchanged 
directly  for  hydrogen  without  the  intermedmte 
separation  of  the  ukyl  halide.  The  presence  of 
other  negative  groups  in  the  benzene  moleonle 
increases  the  ease  with  which  the  NH^  group 
can  displace  halogen  groups.  Thus  the  chlorine 
atoms  of  chlorbenzene  can  be  replaced  by  NH^ 
groups  by  the  action  of  ammonia  if  the  l>enzene 
ring  also  contains  NO,  groups.  A  catalytic 
method  of  preparing  mono-  and  di-methylaniune, 
in  which  the  vapours  of  methyl  alcohol  and 
aniline  are  passed  over  aluminium  oxide  at  400**- 
430°,  is  described  by  Mailhe  and  de  Godcm 
(Compt.  rend.  1918,  166,  467). 

Amines  may  also  be  obtained  by  heating 
zinc  ammonium  chloride  with  alcohols  at  260°- 
260°  (Merz  and  Gaaiorowski,  Ber.  1884,  17, 
623). 

Alcohols  or  phenols  will  react  with  ammonia 
or  its  alkyl  derivatives  on  heating  in  the  presence 
of  zinc  chloride,  calcium  chloride,  or  other 
catalytic  agent  (Merz  and  Weith,  Ber.  1880,  13, 
1298  ;  Merz  and  Mueller,  Ber.  1886,  19,  2901). 

Mixtures  of  the  vapours  of  alcohol  and 
ammonia  or  primary  amine  led  through  tubes 
containing  finely  divided  thoria  or  tungsten 
oxide  at  360°  give  amines  (Sabatier  and 
Mailhe,  Compt.  rend.  1908,  148,  898). 

Sodamide  or  its  alkyl  substitution  products 
may  be  used  instead  of  ammonia  in  the  caae  of 
aliphatic  amines. 

NH^a  -f  CH,a  =  NH,CH,  -f  Nad 

(Lebeau,  Compt.  rend.  1905,  140,  1042;  Cha- 
blay,  Compt.  rend.  1905,  140,  1262).  Cf.  O. 
Matter,  D.  B.  PP.,  301450,  301832.  Sodamide 
will  also  react  with  anhydrous  sulphuric  esters 
of  the  aliphatic  series,  and  with  aromatic  sul- 
phonic acids  to  give  primary  amines  (Jackson 
and  Wing,  Ber.  1886,  19,  902  ;  Titherley,  Chem. 
Soc.  Trans.  1901,  79,  399). 

By  heating  ammonium  chloride  with  a  con- 
centrated solution  of  formaldehyde  under 
pressure,  methylamine,  dimethylamine,  and 
trimethylamine  are  successively  produced  (Esch- 
weiler,  D.  R.  P.  80520,  1893). 

2.  By  reduction  of  nitrogen-containing  sub- 
stances. 

Primary  amines  may  be  obtained  bjf  the 
reduction  of  nitro-  compounds,  nitroso-  com- 
pounds, oximes,  hydrazones,  azo-  and  hydrazo- 
compounds,  amides  and  amidines,  and  nitriles. 
Since  the  nitro-  compounds  of  aromatic  hydro- 
carbons are  easily  prepared  by  direct  nitration, 
the  reduction  of  nitro-  compounds  is  by  far  the 
most  generally  used  methoa  for  the  preparation 
of  aromatic  primaiy  amines.  Zinin  m  1842  pre- 
pared aniline  from  nitrobenzene,  by  the  action 
of  alcoholic  ammonium  sulphide,  and  this 
method  is  still  in  use  for  the  reduction  of  the 
dinitrobenzenes  to  the  nitroanilines.  On  the 
commercial  scale,  as  for  instance  in  the  pre- 

Earation  of  aniline,  iron  and  water  with  some 
ydrochloric  acid  is  usually  employed  aa  the 


AMINEa 


187 


reducing  agent.  Another  method  for  the 
reduction  of  nitro-  compounds,  nit^Ues,  oximee, 
ftnd  hydmzones,  ooniisU  in  heatiiu;  in  a  stream 
of  hydrogen  in  the  presence  of  miely  divided 
niokd  or  copper  (SabaUer  and  Senderens,  Compt. 
rend.  1902,  125,  225).  A  great  deal  of  work  on 
this  method,  resulting  in  a  large  number  of 
patents,  has  been  carried  out.  With  a  copper 
catalyst  obtained  by  reducing  the  carbonate, 
formate,  oxalate,  or  nitrate  l>y  hydrogen  or 
carbon  monoxide  below  red  heat,  reduction  of  a 
nitro-  compound  is  effected  by  hydrogen  at  a 
temperature  of  200**  G.  or  less.  Higher  tempera- 
tures lead  to  impure  products  and  to  poisoning 
of  the  catalyst  (Badiache  Anilin  und  Soda 
Fabrik,  B.  R.  PP.  263396,  1914  ;  282568,  1915). 
Other  contact  agents  are  described  by  the  same 
patentees  in  £ng.  Pat.  5692, 1915.  According  to 
1).  R.  P.  282492, 1915  (Meister,  Lucius,  and  Brun- 
ing)  a  quantitative  yield  of  aniline  is  obtained  by 
passing  nitrobenzene,  steam,  and  hydrogen  at 
120°  C,  over  finely  divided  nickel.  In  £ng.  Pat. 
6409,  1915  (Badische  Anilin  und  Soda  Fabrik), 
the  reduction  of  nitrobenzene  by  carbon 
monoxide  in  presence  of  steam  and  a  contact 
agent,  ip  described. 

Nitro-  compounds  may  be  reduced  to  primaiy 
«.fniTi«w  electrolytically,  in  aqueous  or  ucoholic 
acid  solution,  at  zinc,  lead,  tin,  copper,  or 
mercury  cathodes,  with  a  current  density  of 
0*18  amp./sq.  cm.  Tin  and  lead  are  particularly 
effective  n  tney  are  present  on  the  cathode  in  a 
spongy  state  (C.  F.  Bochringer  and  Sohne, 
D.  B.  P.  116942, 1900). 

The  reduction  of  nitroso-  compounds, 
oximes,  and  hydrazones,  though  often  useful  in 
the  laboratory  for  preparing  special  amino- 
oompounds,  is  seldom  of  use  on  tne  large  scale. 
The  reducing  agents  used  are,  for  nitroso-  com- 

founds,    sudk   as   nitrosophenol,    sulphuretted 
y  drogen  in  presence  of  anunonia ;  for  oximes  and 
hydrazones,  sodium  amalgam  and  acetic  acid. 

The  reduction  of  azo-  compoxmds,  which 
takes  place  according  to  the  equation 

B-N=N-B'-f2H,=R-NH,-FNH,R' 

is  mainly  used  in  the  production  of  aromatic 
primary  diamines  (e/.  p-phenylenediamine,  but 
can  be  used  for  the  production  of  aminophenoU 
or  their  derivatives.  Thus  (D.  R.  P.  48543), 
by  diazotising  one  molecule  of  p-aminophenetol 
and  coupling  with  phenol  the  azo-  compound 
C,H80CtH4--N,^-Cr,H40H  is  produced,  and 
tms  on  etbylation  and  reduction  gives  two 
molecules  of  p-aminophenetol.  The  usual  re- 
ducing agents  for  azo-  compounds  are  stannous 
chloriae,  zinc-dust  and  water  or  aoetio  acid, 
and  sodium  hyposulphite  (Na,S|04). 

Amides,  amidines,  and  nitriles  are  best  re- 
duced by  sodium  and  alcohol. 


RCONH, 

B-CH(NH)-NH, 

RON 


RCH^H, 

RCH,NH,+NH, 

RCH.NH, 


The  fbrmation  of  methylamine  by  the  reduc- 
tion of  alkali  cyanides  and  ferrocyanides  with 
hydrogen  in  the  presence  of  colloidal  palladium 
has  been  patented  (Riedel,  1913,  D.  R.  P. 
264528).  For  the  catalytic  reduction  of  hydro- 
cyanic  add  see  Barratt  and  Titley,  Chem.  Soo. 
TnoB.  1919, 110,  902. 

Steondary  anUntB  may  be  produced  by  reduc- 


tion of  the  i^-esters  of  the  oximes  (Ooldschmidt, 
Ber.  1892,  25,  2594 ;  Dunstan  and  Goulding, 
Chem.  Soc.  Trans.  1897,  71,  573  ;  1901,  79,  628) 
or  of  the  t>onitriles,  or  of  the  condensation 
products  formed  by  the  action  of  primary  amines 
on  aldehydes. 

(CH,),C NCH,  -»  (CH,),CHNHCH, 

R— N  :  C  -»  RNHCH, 
RN  :  CHR'  -»  RNHCH.R' 

A  special  case  of  the  third  reaction — the 
methylation  of  primary  amines  by  means  of 
formaldehyde,  without  isolation  of  the  inter- 
mediate condensation  product — ^is  of  great 
technical  importance.  According  to  a  patent 
of  F.  Bayer  &  Co.  (D.  R.  P.  287802,  1916),  any 

Erimary  amine  may  be  methylated  by  being 
eated  to  a  hi^h  temperature  with  formaldehyde 
in  presence  ox  some  reducing  agent  other  than 
formaldehyde  or  formic  acid.  A  process  for  the 
preparation  of  methylaniline  by  the  action  of 
formaldehyde  on  aniline  has  been  described  by 
G.  T.  Morgan  (£ng.  Pat.  18081,  1916).  The 
mechanism  of  the  reactions  involved  in  methyla- 
tion by  formaldehyde  has  been  investigated  by 
E.  A.  Werner  (Chem.  Soo.  Trans.  1917,  HI,  844). 

3.  From  amides  hy  the  action  of  bromine 
and  pofasK    (Hofmann,  Ber.  1882,  15,  762.) 

This  reaction  is  mainly  applicable  to  the 
preparation  of  primary  fatty  amines,  and  gives 
good  yields  only  with  the  lower  members  of  the 
series.  The  first  product  of  the  reaction  is  a 
bromamide,  and  this  on  further  treatment  with 
potash  gives  potassium  bromide  and  an  iso- 
cyanate,  which  is  saponified,  giving  an  amine 
and  a  carbonate,  the  alkyl  group  being  trans- 
ferred from  the  carbon  to  the  nitrogen  atom,  as 
in  the  *  Beckman  rearrangement '  (Mohr,  J.  pr. 
Chem.  1906,  [2]  73,  177,  228). 
CH,CONH,-fKOH-f.Br, 

=CH,CONHBr+KBr+H,0 
CH,CONHBr-f-KOH  =  CH,NH,+CO,+KBr 

Azides  on  boiling  with  alcohol  or  water,  and  sub- 
sequent treatment  with  cone.  HCl  give  amines. 

RCONj-FCjH.OH  =  RNHCOOC,H,H-N, 
R-NHCOOC,HjH-H,0 

=RNH,H-CO,+C,HjOH 
(Curtius,  Ber.  1894,  27,  779;  1896,  29,  1166; 
Forster,  Chem.  Soc.  Trans.  1909,  95,  433). 

4.  From  compounds  containing  imido  {or 
amido)  groups  in  which  one  atom  of  hydrogen  is 
replaceahle  by  alkali  metals. 

(a)  From  Mocyanates,  Mothiocyanates,  and 
t«ocyamdes. 

Alkyl  ifoeyanates  (prepared  from  metallic 
Mocyanates  and  alkylhaloids)  are  hydrolysed 
by  alkalis  (Wurtz,  Annalen,  1849,  71,  330). 

The  interest  of  this  method  is  mainly 
historical,  since  it  led  to  the  discovery  of  the 
amines  by  Wurtz  in  1848.  Primary  amines 
are  the  chief  product,  but  secondary  and  tertiary 
amines  are  also  formed  in  small  quantities. 
CjH^NCO-i-H.O  =  CjH.NH.+CO, 

Alkyl  t«othiooyanates  and  Mocyanides  are 
hydrolysed  by  treatment  with  concentrated 
hydrochloric  acid. 

C,H^CSH-H,0  =  C,HBNH,-f.COS 
C,HjNC+H,0  =  CjH.NHa+HCOOH 
(5)  Phthalimide,  on  treatment  with  alcoholic 
potash,  gives  potassium  phthalimide,  and  this 


givce  an  alkjl  derivative  cm  treatineut  with 
alkyl  iodide,  which  od  hydrolyBLB  with  fuming 
HCl  yields  a  pismarj  (unine. 

C^,(C0),NK+R1=C^,(C0)JJR+KI 
C^,(C0)^R+2H,0=C^,(C00H),+NH,R 
(Gabriel,  Ber.  1887,  20,  2224;  1891,  24,  3104). 
O&bnel  and  Ohle  (Ber.  1S17,  60,  804,  819)  find 
that  klkylene  oiideB  will  react  with  potasdum 
phthalimide  with  the  ultimate  formation  of 
aminohydrozy  compounds. 

(e)  A  similar  method,  available  for  the 
preparation  of  eeoondary  amines  from  piimaiv, 
Ib  dne  to  Hinibenc  (Annalen,  1891,  179,  260). 
The  eodinm  derivative  of  a  anbstitntod  beoMDe- 
sulphonamide  (derived  from  the  aoticHi  of  beotene 
HulphonylcUoride  on  a  primary  unine)  U  treated 
wiUi  an  alky  1  iodide,  and  the  product  bydiolyeed 
with  hydrochloric  acid  at  12O''-180°. 
CH^O.NRNa  -*  C,H^O,NBR'  -*  NHRR' 

Johnson  and  Ambler  use  toluene-v-sulpbon- 
amides  in  the  same  way  (J.  Amer.  Chem.  8oo. 
1914,  36,  372).  £.  Fischer  finds  that  a  better 
yield  of  the  amine  is  obtained  by  treating  the 
dinibstituted  sulphonanude  with  hydriodic  acid 
and  phoaphonium  iodide  (Ber.  1916,  48,  93). 

(o)  The  derivatives  of  the  amides  of  the 
carboxylie  acids,  tiiongh  leas  suitable,  on  aocoont 
of  their  less  acidio  propeitiea,  con  tie  used  in  the 
same  way  as  the  derivatives  of  the  sulphonamidea 
(Tithorley,  Chem.  Soc.  Trans.  1901,  79,  39  9). 

(S)  From  annpovniit  wkitk  calain  niMancei 
Jonn  wiA  aityl  AoJotdi. 

{a)  Hexamethylene  telramine,  formed  by  the 
action  of  ammonia  on  fonasJdehyde,  gives 
addition  oomponnda  of  the  type  C,H„N,'RI 
with  alkyl  iodides.  These  on  treatment  with 
HQ  and  alcohol  are  decomposed,  giving  primary 
amines  (Delfipine,  Compt.  rend.  1897,  124,  292 ; 

Ann.  Oiim.  Phya.  1S98,  [7]  16,  608), 


Ifi)  Hagnesium  alkyl  iodides  form  addition 
compounds  with  phenyl  Mocyanate ;  these,  on 
treatment  with  water  are  converted  into 
anilides,  which  yield  amines  on  saponificatioa 
(BUise,  Compt.  tend.  1901,  132,  38,  478,  978). 

6.  By  dUliBaiimt  of  amino-  acitU  with  bargla. 
CH,CH<^^^^=  CH,CH,NH,  +  CO, 

7.  AlijAatic  primary  and  lecondary  amintl 
may  be  obtained  by  eA«  action  of  polath  on  th 
p-nitroto-  derivativa  of  seeondary  and  Itrtiary 
aromalie  amino,  compoanda. 
NO-C,H,-N(CHJ,  +  KOH 

=  NO-C,H.-OK  +  »(C!HJ^ 
NO-C,H,NHCH,  +  KOH 

=  NO-C,H,OK+NH,-CH, 

8.  Tertiary  aminet  am  be  obtain^  by  htat- 
ing  primary  and  tteonJary  baett  ttnU  txeat  of 
pofowium  alkyl  nlpAate. 

RR'NH+CH,OS6,K=RR'KCH,+H080^ 


being  gases  or  liquids  with  low  boiling-point*, 
very  soluble  in  water  and  stronaly  «ilr«.lin»i 
to  litmus ;  the  density  of  the  liquid  mem. 
bers  of  the  series  is  about  0'76  that  of  water, 
and  increases  slightly  with  increase  in  tho 
molecular  weight.  Their  basicity,  measured  by 
the  conductivity  method,  is  oonsiderably 
greater  than  that  of  ammonia,  and  they  will 
saponify  eetera  and  precipitate  oxides  from  the 
salts  of^many  of  the  heavy  roetoU.  They  have 
an  ammoniacal  and  fishy  odour.  The  smell, 
inflamm  ability,  boiling-point,  and  solubility  in 
water  become  less  with  increase  in  the  mole- 
cular weight,  and  the  highest  known  membera 
are  odourlrae  aolids  at  otdioary  temperatures. 
They  react  with  moist  air  with  formatioa  of 


AupHano  Ahihsb. 


laomiM 

ands 

b 

t. 

ei 

B.pt. 

8p<t. 

H-  •  ■ 

_ 

-6-7= 

0699(-ll°) 

+7- 

0-686  (-8°) 

+3-6° 

0-862  {-«•) 

-83-8° 

-H9» 

0-708  (-2=) 

B(r 

0-711(  +  Ifl") 

00" 

0-735  (-H6») 

MO-ProOTl     . 
pruii.  n. Butyl 

49° 

0-728  (0°) 

110" 

0-738  (20*) 

166" 

0-771  (0") 

32° 

0-600  (18" 

84* 

0-724  (15«) 

77-8' 

0-748  (16° 

180« 

216-6" 

0-791  (0") 

MO-Bntyl      . 

66" 

0-736  {16« 

136- 

187" 

0-78B  (21") 

He.  Butyl      . 

83° 

0-718  (20° 

ttrl.  Butyl    . 

43-8° 

0-698  (15°) 

prim.  it-Amyl 

104° 

0-766  (19°) 

So-Amyl     \         . 

96° 

0-760  (18*) 

187' 

0-782  (O-) 

236" 

ttrt.  Butyl-methyl 

ea*-^' 

mc  .-Arnjl  .         . 

9r-9i° 

0-749  (20') 

MC.  i*o-Amyl 

83"-^° 

0-767  (18-6«) 

tert.  Amvl     . 
prim.  »-MeiyI        . 

78-6° 

0-748  {16») 

129° 

260" 

"  :.W  : 

— 

176'-n7° 

0-777  (20-) 

0-777  t26-8') 

207' 

~ 

368" 

z 

„      .,  Nonyl      . 

190'-I92° 

„     ,.  Deoyi     - 

,.      „  Dndeoyl  • 

-1-17 

216'-218° 

15° 

232" 

-     1          -          1 

"        "    TrfdM^. 

27° 
2T> 

248' 

266° 

— 

~ 

" 

~ 

37= 

102»[lflmm.) 

36BP 

298--^l° 

„     „   Hexadeo^l 

46" 

187°  (16  mm.) 

„      „  Hoptadeoyl 

49° 

336*-^40= 

_          ,   _  '         _ 

~ 

~ 

AMINEa 

HOMOLOOUBS  OV  AVIUKB. 


189 


Primary  aromatic  amino-  oomponnda 


Fommla 


CHs-CcH4'NRs 


(CH5)iC6Hs-NHg 


Popular  name 


aniline  • 
ortho  Udnldlne 


meta      ,. 

para 

1-2-8  ortho  xylidine 

1-2-4    .. 
1-8-2  meta 


Systematic  name 


•» 


aaymm.  meta  zyli- 

dine 
Bymm.  meta  xylidine 


(GHs)90cH2-NHa  . 

(CsHs'CHs)0cH4'NHt  . 
(CHs)sCH'C6H4'NHs  . 
(CHs)4CcH'NH2    • 

XCHt)(CaH7)08H.vNH2  . 

(CH8)iGH'CH2-GaH4  -NH2 
(GHs)5C<-lfHs 
CcHii'CeH4'irH2  • 
CtHi7'C6H4*NHs  . 
CicHts*C«H4'lfH9 
CisHtT'G«H4KHs  • 


paia  zylldlno 

paiA    amino 

benzene 
mesldine 


ethyl 


pseudo- comidine    . 

para  amino  propyl 

bensene 
eomldine        •        • 

prehnidine     •  • 

Isoduridine     •  • 

carraerylamine  • 

tbymylamine 

para  amino  inobntyl 
bensene 

amino  pentametbyl 
benzene 

amino  iioamyl  ben- 
zene 

para  amino  octyl 
benzene 

amino  cetyl  benzene 

amino  ootadecyl 
benzene 


aminobenzene 

l-methyl  -  2  -  aminoben- 
zene 

1-methyl  -  8  •  aminoben- 
zene 

l-methyl  -  4  •  aminoben- 
zene 

1  :  2-dimethyl-8-amino- 
benzene 

1 :  2-dimethyl-4-amino- 
beniene 

1 :  8-dimethyl-2-amino- 
benzene 

1 :  S-dimethyl-i-amlno* 
benzene 

1 :  8-dlmethyl-6-amino- 
benzene 

1 :  4-dlmethyl-2-amino- 
benzene 

1  -  ethyl  -  4- amino- ben- 
zene 

1:8: 6-trimetfayl-2-ami- 
nobenzene 

1:2: 4-trimethyl-S-ami- 
nobenzene 

1  -  propyl  -  4  -aminoben- 
zene 

l-i0opropyl-4-aminoben- 
zene 

1:2:8:  4-tetiametliyl- 
6-aminobenzene 

1:2:8: 6-tetramethyl- 
4-aminobenzene 

l-metlQrl-4-iMpropyl  -2- 
aminobenzene 

l-methyl-4-iiopropyl  -8- 
aminobenzene 

1  -ifobntyl-4-aminoben- 
zene 

pentamethyl  amino- 
benzene 


1  -  octyl  •  4  -  aminoben- 
zene 

hezadecyl  aminoben- 
zene 

oetadecyl  aminoben- 
zene 


M.pt. 


-ff» 


+42-80 


+490 


+  16-6° 
+68° 


+70° 
+24° 


B.pt. 


8p.  cr. 


+  17° 
152° 

+18-6° 

81° 


188" 
190° 

108° 

108° 

228° 

228* 

216° 

216° 

228^ 

216° 

214'' 

288° 

284° 

226° 

218° 

260° 

266° 

241° 

280° 

280° 

278° 

260° 

810° 

256° 

(14  mm.) 

274*^ 
(15  mm.) 


1*024  (16°) 
0-000  (20°) 

0-006  (26°) 


0001  (16°) 
1076  (17°) 

0018  (26°) 
0-072  (16°) 
0-080  (15°) 
0-076  (22°) 


0*078  (24°) 
0-044  (24°) 

0-087  (25°) 


mon- 
aoetyl 
deriv. 


116° 

110° 

66-6° 
168° 

184° 

00° 
176-6° 
120° 
140-6° 
180-5° 

04-6° 
216° 
164° 

102-6° 
172° 
216° 
72° 
112-6" 
170° 
218° 

08° 
104° 


earboiuttee.  Aromaiio  amines  (benzvlAmine  and 
its  liomolognes)  closely  resemble  the  aliphatio 
amines,  but  are  not  quite  so  strongly  basic  in 
character,  owinff  to  the  presence  of  the  negative 
phenyl  group.  The  aromatic  amino-  compounds 
(aniline  ana  its  homologues)  are  less  basic  than 
ammonia,  and  the  basicity  diminishes  with 
increase  of  the  number  of  phenyl-  groups  attached 
to  the  nitroeen  atom.  Thus  the  stdts  of  diphenyl- 
amine  are  nydrolysed  by  water  to  a  greater 
extent  than  thoee  of  aniline,  whilst  triphenyl- 
amine  is  a  neutral  body  and  forms  no  salts 
with  acids.  Comparatively  few  amines  are 
known  which  contain  only  aromatic  groups ;  of 
these  aniline  and  diphenylamine  are  prepared 
on  the  large  scale  in  tke  dyeing  industry,  as  well 
as  many  secondary  and  tertiary  ammo  com- 
pounds containing  both  fatty  and  aromatic 
groups. 

The  aromatic  amines  are  much  more  easily 
substituted  by  halogens,  the  nitro  group  and 
the  sulphonic  group  than  the  hy&ocarbons 
from  which  they  are  derived,  and  the  substituted 
derivatives  obtained  are  of  great  importance 


in  the  dye  industry.  In  substituting  with 
halogens  or  nitric  acid  it  is  often  necessary  to 
protect  the  amino  group  by  acetylation,  the 
acetyl  group  being  supsequently  removed. 
The  purely  uiphatic  amines  find  little  use  out- 
side synthetical  chemistry.  Some  are  used  in 
the  preparation  of  drugs ;  they  have  also  been 
used  (as  well  as  derivatives  of  aromatic  amines) 
as  catalysts  in  the  vulcanisation  of  rubber  (Twiss, 
J.  Soc.  Chem.  Ind.  1917,  786). 

The  above  lists  of  the  chief  homologues  of 
methylamine  and  aniline  are  taken  from  Meyer 
and  Jacobsen's  Lehrbuch  der  Oiganischen 
Chemie. 

All  classes  of  amines  form  addition  products 
with  acids,  containing  one  molecule  of^base  to 
one  molecule  of  monobasic  acid.  Compounds 
containing  three  molecules  of  HC3  to  one  of 
amine  have  also  been  obtained  (Korczynski,  Ber. 
1908,  41,  4379).  The  picrates  are  qsecially  cha- 
racteristic, and  are  used  for  the  identification 
of  the  amines,  as  are  also  the  double  salts  with 
platinum  and  gold  chlorides,  which  have  the 
genera]  formulae  B,H,PtC]e  and  BHAuCl^  respec- 


190 


AMINES. 


tiyely.  Many  aliphatic  aminea  form  hydrates 
with  one  molaoole  of  water  of  orystaUiaation. 
Double  salts  with  meronrio  chloride  and  stannous 
and  stannic  chlorides  (Dnioc,  Chem.  Soo.  Trans. 
1918,  113,  716),  and  with  sQver  salts,  Grystallise 
welly  and  oi^anio  analogues  of  ammonium  pyro- 
phosphate and  arsenate  are  known,  but  are  not 
very  stable  (Biisao,  Bull.  Soo.  chim.  1903,  [3] 
29,  591).  With  alkyl  halides  they  form 
quaternary  ammonium  compounds  of  the  time 
NRR'R"R'"I,  where  RR'R"R'"  mav  be  the 
same  or  different  radicals.  In  cases  where  these 
radicals  are  all  different,  the  substances  are 
capable  of  existing  in  two  enantiomorphous 
optically  active  forms,  and  a  number  of  these 
have  been  isolated.  Enantiomorphic  compounds 
of  the  type  RR'R^N^O  have  also  been  isohited 
(Meisenheimer,  Ber.  1908,  41,  3966 ;  Annalen, 
1911,  386,  117).  The  quatematy  ammonium 
compounds,  unlike  their  inoiganic  analogues,  are 
not  decomposed  on  boiling  with  potash;  on 
heatinff  alone  they  give  tertiaiy  amines  and 
alkyl  nalidee.  The  correspondmg  bases  are 
obtoined  from  their  halides  by  treatment  with 
moist  silver  oxide;  they  are  stronglv  alkaline 
to  litmus,  and  the  solutions  generally  decom- 
pose easily  on  evaporation,  but  some  ol  the 
aliphatic  members  have  been  obtained  crystal- 
line by  evaporation  in  ixicuS,  The  rate  of  forma- 
tion of  quaternary  ammonium  compounds  from 
tertiary  amines  and  alli^l  haloids  is  found  to 
vai^  greatly  with  the  constitution  of  the  re- 
actmg  substance  and  the  nature  of  the  solvent 
(Mensohutkin,  Zeitsch.  physikal.  Ghem.  1890, 
6,  41 ;  Wedekind,  Ber.  1899,  32,  611 ;  Annalen, 
1901,  318,  90 ;  Preston  and  Jones,  Ghem.  Soc. 
Trans.  1912,  101,  1930;  Thomas,  Chem.  Soc. 
Trans.  1913,  103,  694). 

The  formation  of  quaternary  ammonium 
compounds  by  addition  of  excess  of  methyl 
iodide  to  an  amine  gives  a  quantitative  method 
for  the  determination  of  the  number  of  replace- 
able hydrogen  atoms  in  the  substance.  Analysis 
of  the  orig^oal  compound  and  of  its  quaternary 
methyl  derivative  gives  the  number  of  methyl 
groups  which  have  entered  into  the  molecule. 

(Compounds  containing  five  hydrocarbon 
radicals  attached  directly  to  nitrogen  were  for  a 
lonff  time  thought  to  be  incapable  of  existence. 
Such  compounds  have  now  h&BD.  isolated  by 
Schlenk  and  Holtas  (Ber.  1916,  49,  603 ;  1917. 
60,  274). 

With  several  reagents,  the  different  classes 
of  amines  show  different  reactions,  and  separa- 
tion and  purification  of  the  amines  formed  in 
many  of  tne  methods  above  referred  to  may  be 
carried  out  by  making  use  of  such  differences. 
Primary  and  secondary  amines  sometimes  give 
similar  reactions,  whilst  tertiary  amines  are  more 
stable. 

Beactions, 

1.  With  nitrous  acid. 

Primary  amines,  on  boiling  with  potassium 
or  sodium  nitrite  in  acid  solution,  give  alcohols 
or  phenols  with  evolution  of  nitrogen. 

RNH,+HONO  =  ROH-hN,+H,0 

In  many  cases  where  a  primary  alcohol  would 
be  expected  a  mixture  of  primary  and  secondaiy 
alcohols  IB  obtained  (Heniy,  Compt.  rend. 
1907,  146,  899,  1247). 

(Secondary  amines  give  nitrosamines,  which 


on  boiling  with  cone.  HCl  are  again  transformed 
into  the  original  amines. 

RR'NH-I-HONO  =  RR'NNO+H.O 
RR'NN0+2Ha  =  RR'NH-Ha+NOa 
Tertiary  amines  do  not  react. 
Primary  aromatic  amino-  compounds  react 
differently  if  their  solutions  are  Kept  cooled. 
They  ^ive  diazo-  compounds  aocordmg  to  the 
f ollowmg  equation  : — 

RNH„HC1+H0N0  -  RN  :  Na+2H,0. 

This  reaction  is  of  the  greatest  importance, 
for  the  diazo-  compounds  are  venr  unstable,  and 
on  treatment  wiui  various  substances  either 
form  substitution  products  of  benzene  hydro- 
carbons with  evolution  of  nitrogen,  or  retain  the 
nitrogen  and  form  azo-  compounds,  which  are 
the  parent  substances  of  the  azo-  dyes.  Thus, 
if  the  diazo-  compound  be  boiled  with  water, 
alcohol,  cuprous  chloride,  bromide,  or  cyanide, 
phenol,  benzene,  chlor-  brom-  or  cyan-  derivatives 
respectively  are  produced.  If  the  diazo-  com- 
pound is  treated  with  a  substance  containing  a 
phenol  or  aromatic  amino-  group,  a  coloured 
substance  is  formed  which  is  capable  of  fixing 
itself  as  a  dye  on  a  fabric.  Compounds  derived 
from  unsubstituted  amines  have  only  a  limited 
application  for  dyeing  purposes,  as  they  are 
generally  insoluble  in  water ;  the  sulphonic  acids 
aerived  from  them  are,  however,  generally 
soluble,  and  are  used  extensively  {see  art.  Azo- 
coLouRivo  MATTERS).  The  reactions  are  ex- 
pressed by  the  following  equations : — 

CJB[5N,CH-C,HjOH=C,H6N :  NCH^OH-f  HQ 
C,H^,CH-C,H,N(CH,), 

=C^8N :  NC  JB[4N(CH,),+HC1 

Tertiary  aromatic  compounds,  such  as 
dimethylaniline,  react  with  nitrous  add  to 
form  p-nitroso  compounds,  where  the  nitroso 
nitrogen  is  attached  to  the  carbon  of  the  benzene 
rin^  in  the  para-  position  to  the  substituted 
ammo-  group.  These  are  highly  coloured  sub- 
stances, and  serve  as  intermediate  compounds 
in  the  production  of  certain  colouring  matters 
(methylene  blue,  &c.),  which  are  used  in  the 
colour  industry.  On  treatment  with  oaostio 
potash  they  give  secondaiy  amines  and  salts  of 
nitroso  phenol. 

Since  nitrites  of  primary,  secondary,  and 
tertiaiy  amines  have  been  isolated  (Wallaoh, 
Chem.  Zentr.  1907,  ii.  64;  Neogi,  Chem.  Soc 
Trans.  1912,  101,  1610;  and  1914,  106,  1270), 
it  is  probable  that  in  all  the  above-mentioned 
reactions  the  nitrite  of  the  amine  is  formed  as 
an  intermediate  product. 

2.  With  chlorides  of  aromatic  stdphonic  adds. 

Primary  and  secondary  amines  in  strong 
alkaline  solution  are  converted  into  amides 
bv  shaking  with  chlorides  of  aromatic  sul- 
phonic acids;  tertiary  amines  do  not  react. 
Df  these  amides,  PhSO,NHR  and  PhSO,NRR' 
respectively,  the  first  only  are  soluble  in  dilute 
alkalis  with  formation  of  salto.  The  primary 
and  secondary  amines  can  be  regenerated  from 
the  amides  by  boiling  with  cone.  HCl  or  HJSO^ 
at  120''-160°  (Hinsb^,  Ber.  23,  2963  ;  Annalen, 
1891,  266,  178).  £.  Rscher  (Ber.  1916,  48,  93) 
recommends  hydrolysis  by  hydriodic  acid  and 
phosphonium  iodide.  These  reactions  provide  the 
only  generally  applicable  method  for  separating 
mixtures  of  primary,  secondary,  and  tertiary 
amines. 


AMINES. 


191 


5.  WUh  acetyl  ehioride  or  acdxc  anhydride, 
Frimttiy  and  teoondary  amines  give,  as  a 

rale,  acetyl  deiiyatiYeB  wnich  are  insoluble  in 
cold  water ;  tertiary  amines  either  do  not  react, 
or  form  soluble  acetates  and  hydrochlorides.  The 
primary  and  secondary  amines  may  bd  regene- 
rated by  hydrolysis  A  the  acetyl  derivatives. 
Since  the  velocity  of  the  formation  of  the  acetyl 
derirative  of  the  primary  is  much  greater  than 
that  of  the  secondary  amine,  a  method  based 
on  this  difference  in  property  has  been  used  to 
separate  the  two  (Menschutkin,  Chem.  Zentr. 
1900,  1,  1071  ;  Potozki  and  Gwosdow,  ibid. 
I90a,  ii.  339). 

The  action  of  benzoy  chloride  is  similar  to 
that  of  acetyl  chloride. 

4.  With  oxalic  eeAer. 

Sereral  of  the  aliphatic  primary  and  secondary 
amines  react  with  ethyl  oxalate,  the  former 
giving  solid  diamides  and  the  latter  liquid 
oxamic  esters.  Tertiaiy  amines  do  not  react. 
Primary  and  secondary  amines  are  regenerated 
by  boiUng  with  potash  (Hofmann,  Ber.  1870,  3, 
109,  776;  DuvuUer  and  Buisine,  Ann.  Chim. 
Pbys.  [6]  23,  299).  Hofmann  used  these 
reactions  for  the  separation  of  the  three  ethyl- 
amines,  and  it  has  been  used  since  in  other  cases. 

6.  With  magnesium  methyl  iodides. 
Primary  amines  react,  givins  two  molecules 

of  methane  for  every  molecule  of  amine : 
IlNH,+2MeMgI  =  RN(MgI),+20H« 

Secondary  amines  react  in  a  similar  manner, 
but  give  one  molecule  of  methane  for  every 
molecule  of  amine : 

RR'NH-1-CHJtfgI  =  RR'NMgl+CH^ 

Tertia^  amines  either  do  not  react  or  they 
form  addition  compounds  with  the  reagent 
(Sudborough  and  Hibbert,  Chem.  Soc.  Trans. 
1909,  96,  477 ;  Hibbert  and  Wise,  Chem.  Soc. 
Trans.  1912,  101,  344). 

6.  -  With  O'Xylylene  bromide. 

Primary  amines  react,  giving  two  molecules 
of  HBr  and  liquid  derivatives  of  o-xylyleneimine 
(dihydrowoindol). 

Secondary  amines  react,  eiving  crystalline 
quaternary  ammonium  bromides  and  one  mole- 
cule of  HBr : 

^•H.<^g  +  NH.R 

=  ^•H«<XH*!>NR  +  2HBr 
^•«*<CT:Br  +  NHRR' 

=  C.H,<^|>N<g,  +  HBr. 

Br 

Tertiary  aliphatic  amines  give  addition  pro- 
ducts of  one  molecule  of  xylylenebromide  with 
two  of  amine.  Tertiary  aromatic  amines  and 
amino-  compounds  do  not  react  (Scholtz,  Ber. 
1898.  31,  1707). 

7.  With  aromatic  aldehydes. 

Primary  and  secondary  amines  form  com- 
pounds with  loss  of  water : 

C,H,CHO-f-NH,R  «=  C-H.CHNR-fH,0. 
C^jCHO+2NRR'H=C^,CH(NRR')2+H,0.^ 

Tertiary  amines  do  not  react  (Schiff,  Annalen, 
159,  159). 

8.  With  chloroform  and  potash. 


Primary  amines  give  Mocyanides  on  warming, 
RNH,+CHa,+3KOH-RNCH-3Ka-f3H,0 

(Hofmann,  Ber.  3, 767). 

Secondary  and  tertiary  amines  give  no 
characteristic  reaction. 

9.  With  carbon  distdphide. 

Aliphatic  primaiy  and  secondary  amines 
react  as  follows  : — 

CS.-f2NH.R«SC<^.^jj.R. 

CS,+2NHRR'=SC<^.jj2j^j^, 

On  boiling  the  product  of  the  action  of  CS^ 
on  primary  amines  with  metallic  s^ts  (Hgd^  or 
FeOt)*  mustard  oils  are  produced,  and  primary 
amines  partly  regenerated. 

^<ffi.NH,R  -  SCNR  +  H.S  +  NH,R 

(Hofmann,  Ber.  8,    105,   461;    14,   2754;    15, 
1290). 

Aromatic  amines  give  substituted  thioureas. 

2RNH,-fCS,«=H;3-J-(RNH),CS. 

10.  WOh  the  alkali  metals. 

Primary  and  secondary  amines  dissolve  with 
evolution  of  hydrogen  and  formation  of  sub- 
stances of  the  type  RNHK  or  RNK^.  Tertiary 
amines  do  not  react. 

11.  With  oxidising  agents. 

Oxidation  with  potassium  permanganate 
decomposes  aliphatic  amines  with  formation  of 
aldehydes  and  acids. 

With  Caro's  acid  (H^SO^),  primary  amines 
of  the  type  RCHjNH,  are  oxidised  to  hydroxyl- 
amines  and  hydroxamic  acids,  all  of  which  give 
a  characteristic  colouration  with  ferric  chloride. 
Kctoximes  are  formed  from  amines  of  the  type 
RR'CH  -NH,,  whilstthoseof  the  typeRR'R"C  -NH, 

g'ivc  nitroso-  and  nitro-  derivatives  (Bamberger, 
er.  1902,  35,  4293  ;  1903,  36,  710). 
With  hydrogen  peroxide  aliphatic,  secondary, 
and  tertiary  amines  give  hydroxvlamines  and 
N-oxides  of  type  RR'NOH  and  RR'R"NO  (Dun- 
Stan  and  Goulding,  Chem.  Soc.  Trans.  75, 
1104). 

Oxidation  of  aniline  and  its  para  compounds 
gives  quinone. 

12.  With  hypochlorous  acid. 

Tertiary    amines   react    with    hypochlorous 
acid  to  give  a  dialkylchloramine  (Meisenheimer, 
Ber.  1913,61,  166): 
(CH,),N+2HC10 

»=  (CH,),NCl-f  CHj04-H,0+HCl 
DiAMims. 

These  may  be  regarded  as  derived  from 
hydrocarbons  by  replacement  of  two  hydrogen 
atoms  by  two  amino-  groups,  or  from  two 
molecules  of  ammonia  by  replacement  of  two 
hydrogen  atoms  one  from  each  molecule  by  a 
hydrocarbon  residue.  Certain  of  them  occur 
as  decomposition  products  of  the  animal  organ- 
ism, the  chief  of  these  being  putrescine  (tetra- 
methylene  diamine),  and  cadaverine  (penta- 
methylene  diamine).  Diamino-  acids  are  an 
important  product  of  the  decomposition  of 
proteins. 

Preparation. — The  methods  are  entirely 
analogous  to  those  used  in  the  preparation  of 
monamines.  Aliphatic  diamines  are  obtained 
by  the  action  of  aqueous  ammonia  on  dihalogen 


192 


AMINES. 


derivatiyee  of  hydrocarbons ;  ttuB  method  is  not 
generally  apphcable  to  the  preparation  of 
aromatic  mono-  or  diamine-  compounds,  bat  a 
modification  of  it,  which  consists  in  treatment 
of  p-chlormonamines  with  aqueous  ammonia  in 
presence  of  copper  salts,  is  used  in  the  commercial 
manufacture  of  p-phenylene  diamine  and  its 
homologues  (Ger.  Pat.  204848,  1908).  Aromatio 
diamino-  compounds  are  prepared  on  the  oom« 
meroial  scale  chiefly  by  the  reduction  of 
dinitro-  compounds  ;  but  practically  all  the 
methods  for  the  production  of  monamines  are 
also  available  for  that  of  diamines. 

Properties.  —  The  aliphatic  diamines  are 
stTonp;ly  basic  snbstanoes,  their  basicity  in- 
creasmg  with  the  number  of  methylene  groups 
(Bredig,  Zeitsch.  physical.  Chem.  1894,  13,  308). 
Their  boiling-points  are  much  higher  than  those 
of  the  corresponding  monamines.  Their  hy- 
droxides, which  are  diacid  bases,  are  extremely 
stable,  and  are  only  decomposed  on  boiling 
with  caustic  alkalis  or  distillation  over  metallic 
sodium.  The  list  of  the  chief  aliphatio  dia- 
mines and  their  physical  constants  (000  p.  133) 
is  taken  from  Meyer  and  Jacobsen's  Lehrbuch 
der  Organischer  Chemie.  The  unsubstituted 
aromatic  diamino  compounds  di£Fer  from  the 

Aliphatic 


corresponding  monamines  by  being  easily 
soluble  in  water.  Their  solutions  in  water  are 
easily  oxidised,  but  the  dry  bases  are  stable  in 
air. 

Reactions. — ^Diamines  give  the  ordinary 
reactions  characteristic  of  the  amino-  group,  but 
primary  aromatio  o-amino-  compounds  and  to 
some  extent  aliphatic  diamines,  possess  m 
addition,  the  property  of  forming  condensation 
products  containinff  nitro^^  rings,  m-  ftnd  p- 
diamines  do  not  exnibit  tms  property. 

1.  Wiihaldehyd€S. 

With  aliphatic  diamines,  cyclic  compounds 
are  formed  as  well  as  the  ordinary  alkylidene 
bases.  Thus  the  action  of  formaldehyde  on  cold 
solutions  of  ethylene  diamine  results  in  the 
formation  of  a  compound  CgH|,N4,  to  which 
the  formula 

CH,— N— CH,— N— CH, 

CH,— l^--CHg--^— CH, 

has  been  assigned  (Bischoff,  Ber.  1898,  31,  3254). 
Aromatic  o-diamino-  compounds  give  alde- 
hydines  or  anhydro  bases : 

DiAimnBS. 


Ethylenediamine 
Propylene     „ 
Tiimettaylenediamine 


fl/S-diaminobatans 


fir 


/M- 


It 

tf 
ft 
f» 


ti 


»> 


pentane 


f» 


/l-methyl-a^diaminobutane 
*C-diamlnohez«ne    .        • 


/i-methyl-a^-diamlnopentaae     . 
/^methyl-oe-       „  »» 

/ly-dlmethyl-^y-dlaminobutane 

aq-dlaminoheptane  .        • 
atf-dlamlnoociane 

^«•dimethy^^«•diamlnobezane  . 

•)4-dlmethyl-yt-dlaminohexane 
flu-diamlnononane  • 

^C-dimethyl-^C-di  aminoheptane 

ajc-diamlnodecane  . 

^1|•dlmetllyI-^q•diaminooctane 


Formula 


KHa'CHa'CHgyHa 

KHs'CH2'CH2'CH2'NH9 

0H8'CHaCH(yHy)-CHa  WHa 
0Hs'0H'(NH2)-GHs'GH8'NHs 

inia-CHg-CHo-CHa-CHaOHalrHa 
G^OHCNHaJCHa'CHcNHaJCH  8 


KUaOH|GH(CH8)CH20HflKH, 

NHa-CH2(CH,)4CIl2'KH2 
GH3*CH(KH2X0Hs)80H(NH2)0H, 

irH2CH2CH(CH.)-0H2CH(irH,)CH. 
NH,-CHaCH(CH,)(OH2)20HjKHa 

.    (0H8)20(HH2)0(NH2XCH8), 

NHt(CH2),NIIi 
NU,(CHa)8NU, 

(CHs).C(KHa)(CH2WNH.  X3(CH3)t 
C,H,C(CH*)(NH,)(NH  )C(CH8)-C2H4 

KH2(CH2)8NU2 

(CH8)2C(HH2)(CH2)8(NH2)C(CH  .h 
KH2(CH2)io»'Ha 

(CH8)2C(NHa)(CH2)4(NH,)C(CH8)8 


ILpt. 


+8-60 


only  known 

amodlflca' 

tion 
/imodiflca* 

tion 
inactive 

form 
active  form 

^  derivative 


28°-2©° 
62° 

solidifleB 

only  known 
87*-S7-6° 


81° 


B.pt. 


116-6° 
1190.1200 

1860-18C* 
(788  mm.) 
180^-166° 

141° 

(788  mm.) 

IM^'-IW® 

asitasalta 

178°-l7»o 

4e°-4r 

(20  mm.) 

48°-44<» 

(11-12  mm.) 

172°-178° 

170° 

100° 

(20  mm.) 

176-6° 

(768  nun.) 

174-6°-176-6°| 

(762  mm.) 

176° 
78°-80° 
(18  mm.) 
147°-140*5 
(740  mm.) 
228'-226° 
226°-226° 

186° 

(768  mm.) 

as  lt«  salts 

268°-269° 

204°-206° 
(740  mm.) 

140° 

(12  mm.) 

^°-220° 


8p.gr. 


0-002 
0-878 


0-917  (0°) 


0-8886 


{^ 


0-868 


Q 


0-8664  Q 
0-8J44  (  «°) 


/\NH,     OHCR     /\/^^\ 


vw. 


+ 


OHCR 


kA 


^CR  +  2H,0 


N-CHaR 


(Ladenburg  and    Engelhrecht,   Ber.    1878,   11, 
1653  ;   Hinsbers,  ibid.  1886,  19,  2c  25). 

The  aldehydines  are  strongly  basic  bodies, 


and  not  decomposed  on  boiling  with  dilute 
acids  and  alkalis.  They  are  very  stable  towards 
oxidising  and  reducing  agents.  Their  deriva- 
tives are  used  as  dyes. 

p-  and  m-diamines  give  alkylidene  bases. 

2.  With  \.2-dicarbonyl  compounds  {aldehydes 
or  ketones). 


AMINES. 


I9S 


+  2H,0 


o-Biamino  compounds  react  to  give  quinoxa- 
line  (azine)  derivatives  (Hinsbeig,  Annalen,  342, 
1886): 

^Anh,    0:CR       \/\n/^^ 

3.  WUh  nMnms  acid, 

o-Diamino-  compounds  form  azimines  (La< 
denbuzg) 

yv     /NH 


(^;  +  HONO=lJ^      ,.N  +  2H.O. 


\ 

] 


Diamino-  compounds  both  m-  and  p-  wiA 
react  in  the  orcUnaiy  way  in  presence  of  much 
hydrocblorio  aoid/giving  bis-diazo-  compounds ; 
in  neutral  solutions  m-diamino-  compounds  gire 
triamino  azo  benzene  and  its  homologues.  The 
reaction  in  the  case  of  m-phenylene  diamine  is : 
2C.H4(NHj),  +  HONO 

=  NH,-C,H^-N :  N-C,H,(NH,)^ 
The  substances  formed  are  brown  and  very 
deeplv  coloured.  The  reaction  is  used  as  a  test 
for  the  presence  of  nitrites  in  water  analysis 
(GriesB,  Bar.  1878,  11,  624). 

Alip^tic  diamines  give  glyoob  and  oxides 

4.  WUh  organic  acids,  acid  Moridea  or 
anhydrides. 

Aliphatic  diamines  and  m-  and  p-diamino- 
compounds  form  normal  derivatives;  in  the 
cases  of  aliphatic  substances,  these  derivatives 
axe  partial^  decomposed  on  heating,  giving 
cyolio  compounds  of  the  iminoazole  type : 
CH.NHCOCH,    CH,— NH 

CH,-NHCOCH,    CH^N^ 

o-Biamino-  compounds  give  similar  com- 
pounds, without  the  interm^iate  formation  of 
the  acyl  derivative: 

ONH. 
I        +CH,<X)OH 


CO 


P-CH,  +  2H,0 


5.  Wiih  mineral  acids. 

All  diamines  form  stable  salts.  Those  of 
the  aliphatic  series  are  decomposed  on  heatiug 
with  separation  of  ammonium  salt  and  formation 
of  o^dio  compounds.  Thus,  tetramethylene 
iiamme  gpives  |>yxrolidin6  and  pentamethylene 
diamine  ffivespiperidine : 
NH,(CH,)^NH,»Ha=NH4Cl+H,C, ,CH, 


y^' 


CH, 
NH,(CH,),NH„Ha-:NH4a+H,0/\C5H, 

H,cMcH, 

V  The  higher  homologues,  however,  do  not 
form  ring  compounds  containing  a  corresponding 
number  of  atoms  in  the  ring.  Thus,  octomethy- 
lene  diamine  hydrochloride,  on  heating,  does  not 
give  octomethylene  imine,  which  would  contain 
a  ring  of  nine  atoms,  but  2-butylpyrrolidine. 
Similarly,  decamethylene  diamine  gives  2- 
hezylpyrrolidine  (Blaise  and  HouiUon,  Compt. 
rend.  1006,  142,  1541 ;    1906, 143,  361). 

Vol.  L— r. 


The  aromatic  diamines  are  the  starting- 
points  for  the  preparation  of  a  large  number  ot 
dyes,  and  hence  are  of  commercial  importance, 
liie  following  are  the  chief  members  ot  the 
series: — 

o-Phenylenediamine  C«H4(NH,),.  First  ob- 
tained by  Griess  by  the  distillation  of  o-m-  and 
m-p-  diaminobenzoio  acid : 

C,H,(COOH)(NH,),=CJB,(NH,),+CO, 
(1,  2,  8,  or  1.  8,  4)  (1,  2) 

(J.  pr.    Chem.  [2]  3,   143).    By  the  reduction 

of  o-nitraniline  C,H«(N02)  (NH,)  (1,  2)  (Zincke 

and  Sintenis,  Ber.  6,  123),  or  of  o-dinitroben- 

zene   GJi^CNO,).   (1,   2)  (Rinne    and    Zincke, 

Ber.  7,  1374),  with  tin  and  hydrochloric  acid. — 

CrystaUiBes  from  water  in  laminae,  melting  at 

102**.    Boils  at  252*.     ReadUy  soluble  in  water, 

alcohol,  and  ether.    IHacid  base,  tiie  sulphate 

2[GcH4(NHa),,H,S04l  3H,0     forms     nacreous 

lanunsB.  It  gives  all  tne  reactions  for  o-diamino- 

compounds  referred   to   above.    Gn  oxidation 

with  ferric  chloride  it  gives  a  red  compound, 

diaminophenazine : 

-i-O^4(NH,),-f30 


NH, 


N 


G^,(NH,),  +3HgO 


N 


m-Phenyfenediamine  CJH.t(NR^)^  By  re- 
ducins  Yn-dinitrobenzene  or  m-nitruiiline  with 
iron  mings  and  acetic  acid  (Hofmann,  Proc. 
Roy.  Soc.  11,  518;  12,  639),  or  with  tin  and 
hydrochloric  acid  (Gerdemann,  Zeitsch.  f.  Ghem. 
1865,  61).  By  reducing  either  (1,  2,  4)-  or 
(1,  2,  6)-dinitrobenzoic  acid  with  tin  and 
hydrochloric  acid,  the  earboxyl  group  being 
eliminated  in  the  process  (Zincke  and  Sintenis, 
Ber.  5,  791 ;  Griess,  Ber.  7, 1223).  On  a  manu- 
facturing scale  it  is  prepared  by  reducing  dinitro- 
benzene  with  iron  turnings  and  hy<&ochloric 
acid. — Separates  from  its  solutions  as  an  oil 
which  does  not  readily  solidify  unless  brought 
in  contact  with  a  crystal  of  the  base.  Melts 
at  68°,  and  boils  at  287^  Readily  soluble  in 
water.  It  gives  the  cypical  reactions  of  m* 
diamino-  compounds  {see  above). 

By  the  action  of  a  diazobenzene  salt  on 
m-phenylenediamine,  chrysMine  (unsymme- 
trical  diamidoazobenzene)  is  produced: 

Cja,N,Cl  +  G^^NH.), 

=  fia  +  OgHjN :  N-C,H,(NH,)r 

In  the  manufacture  of  phenylene-brown  and 
chrysoldine  Uie  solution  of  crude  m-phenylene- 
diamine  hydrochloride  obtained  by  the  reduction 
of  m-dinitrobenzene  is  employed,  without  first 
isolating  the  base.  A  violet  colouring  matter  is 
obtain^  by  heatins  m-phenylenediamine  with 
aniline  hy^ochloriae  to  190*-200*,  and  a  blue 
colouring  matter  by  heating  it  with  m-phenylene- 
diamine nydrochloride  (Erause,  Ber.  9,  835). 

P'Phenylenediamine  0,H4(NHs)(.  Obtained 
by  reducing  p-dinitrobenzene  (Rinne  and  Zincke, 
Ber.  7,  871),  or  jj-nitraniline  (Hofmann,  Proc. 
Boy.  Soc.  12, 639),  or  aminoazobenzene  (Martina 
and  Griess,  J.  pr.  Chem.  97,  263),  with  tin  and 
hydrochloric  acid,  aniline  being  formed  simul- 
taneously in  the  case  of  aminoazobenzene. 
Along  with  diaminodiphenylamine  by  reducing 
aniline-black  with  tin  and  hydrochloric  acid  or 


104 


AMINBa. 


with  hydriodio  add  and  amoiphons  phosphorus 
(Nietzki,  Ber.  11,  1007).  By  distiUing  (1,  2,  0)- 
diammobenzoio  aoid  (Griees,  Ber.  6,  200).  By 
action  of  2>-ohloraniline  on  aqneous  ammonia  in 
presence  of  copper  salts.  CryBtala,  melting  at 
147*.  Boils  at  267^  Sublimes  in  leaflets. 
Readily  soluble  in  water,  alcohol,  and  ether. 
Yields  quinone  on  oxidation.  When  oxidised  in 
the  presence  of  primary  amines  or  phenob  it 
gives  indamtnes  and  indophenols,  these  on  heating 
produce  safranines.  By  heatins  it  with  sulphur 
to  150^-180*,  it  is  converted  into  diamino* 
thiodiphenylamine  {leueoihuminef  Laidh's  white) 


N=<o^;SNi:!> 


which,  when  oxidised  with  ferric  chloride,  yields 
thionine  {Lauth'a  violet) 

N 

X 

^  NH,Ha 

The  latter  colouring  matter  may  also  be  obtained 
b^  the  simultaneous  oxidation  of  p-phenylene- 
diamine  and  sulphuretted  hydrogen  by  ferric 
chloride  in  aqueous  solution  (lAuth*  Gompt.  rend. 
82, 1441 ;  BulL  Soc.  Chim.  26,  422 ;  Bemthsen, 
Annalen,  230,  108).  If  dimethyl-^phenylene- 
diamine  OtH4(NMe,)(NH,)  is  substituted  for 
l>-phenylenediamine  in  the  foreeoing  reaction, 
tetramethylthionine  {methylene  wne)  is  formed 
{v.  Methylene  blue). 

TolyUne-4iam%nee  (Diamincikilueines) 
C,H,(CH,)(NH.)^ 

All  the  six  possible  compounds  are  known. 
Their  physical  constants  are  as  follows : — 

l-Methyl-2  : 3-diaminobenxene   61*  266* 

2:4        „  „        00*  283*-286* 

2:6        „  „        64*  273* 

2:6        „  „      103*  — 

3:4        „  „        88*  265* 

3:6         „  „        —  284* 

Only  two  of  these,  however,  are  of  technical 
importance. 

Tdylenediamine  CeH,(CH,)(NH,),  (1,  2,  4). 
Obtained  by  the  reduction  of  the  corresponduiff 
dinitrotoluene.  Sparingly  soluble  in  coldt 
readily  soluble  in  boiling  water,  in  alcohol,  and 
in  ether.  Forms  onrstadline  salts.  As  the  two 
amino  groups  in  this  compound  are  in  the 
meta-  position  to  one  another,  it  is  an  analogue 
of  m-phenylenediamine,  which  it  resembles  in 
many  of  its  reactions :  thus  2 :  4-tolylenediamine 
may  either  wholly  or  in  part  replace  the  fit- 
phenylenediamine  used  in  the  manufacture  of 
phenylene-brown,  producing  colouring  matters 
the  shade  of  which  is  redder  than  that  of  ordinary 
phenylene-brown. 

ToLyUnediamine  G,H,(CH,)(NH,),  (1,  2.  6) 
is  obtained  by  the  reduction  of  the  corresponding 
m-nitro-o-toluidine  C,H,(CH,)(NHJN[NO,)  (1,2,6) 
with  tin  and  hydrochloric  acid  (JBeilstein  and 
Kuhlberg,  Annalen,  168,  360 ;  Ladenbuig,  Ber. 
11,  1661).  Formed  along  with  o-toluidine  when 
the  aminoazotoluene  prepared  from  o-toluidine 
is  treated  with  the  same  reducing  agent : 


tff 


M 


♦» 


»f 


Cfl, 


^ 


+2H, 


CH, 

0"' 


CH, 

ONH,. 


The  two  bases  may  be  separated  by  fractional 
distillation  (Nietzki,  Ber.  10, 832).  This  reaction 
is  utilised  in  preparing  the  mixture  of  o-toluidine 
and  y-tolylene-diamine  which,  after  the  addition 
of  a  second  molecule  of  a  monamine  (either 
aniline  or  o-  or  jp-toluidine),  yields  on  oxidation 
safranine.  On  a  large  scale  the  aminoazo- 
toluene is  reduced  with  iron  turnings  and  hydro- 
chloric acid.  Crystallises  in  colourless  rosettes 
of  tabular  crystsJs.  Readily  soluble  in  water, 
alcoholf  and  ether,  si>aringl^  soluble  in  benzene. 
Yields  on  oxidation  toluquinone  GgH,(0H,)Ot. 
Other  diamines  of  this  series  are— 
Xylylene  dtamines : 

1.3-dimethyl9  2.4-diaminobenzene,  m.p.  64*. 

1.3-     „         4.6        „  „         ,,104*. 

1.8-       „  2.6         „  „  „    77  • 

DkkmmotrimethylhenMenss :  diamino-  pseudo- 

onmenes: 
1.2.4-trimethyl,  6.6-diaminobenzen0,  m.p.  00*. 
1.2.4-      „  3.6       „  „         m.p.  78*. 

Diamwo  meeUylene: 
L3.6-trimethyl,  2.4-diaminobenEene,  m.p.  00*. 
Similar  diamines  have  been  prepared  from 
naphthalene  and  other  hydrocarbons. 

TBIAimfBB,  TSTRAMDm,  AND  PmiTAimrBS. 

Very  few  of  these  substances  are  known. 
Their  properties  axe  similar  to  those  of  other 
substances  containing  the  amino  group. 

1.2.3-triaminopropane  I  b.p.  100*  (Curtius, 
J.  pr.  Caiem.  1000,  62,  232). 

2.3.6-triafninoAea;aiis(Morelli  and  Marohetti, 
Atti  del  Acoad.  Lin.  1008,  [6]  17,  1,  260). 

The  tiiree  modifications  of  triaminobenzene 
an  all  known. 

h2.^trianwnob&n9ensi  m.p.  103*;  b.p.336*. 

h2,^triamwobenMene  is  formed  by  reduc- 
tion of  o-p-dinitraniline  or  of  chrysokune.  On 
oxidation  it  gives  triaminophenazin. 

'LZ.6-tnamin6benxene  is  only  known  in  the 
form  of  its  salts. 

1.2.3.4.  and  1.2.4.6-(efraiiwno6efi«efies  ]^- 
pared  by  the  reduction  of  oximes  and  nitro 
compounds,  have  been  isolated  as  their  sparingly 
soluble  sulphates  (Nietzki  and  Schmidt,  Ber. 
1880,  22,  1648 ;  Nietzki,  Ber.  1887,  20,  2114). 

Pentaminobemene  has  been  obtained  as  the 
hydrochloride  with  3  molecules  of  HGl,  by  reduc- 
tion of  triaminodinitrobenzene  (from  tiibrom- 
bensane  and  ammonia).  Pentaminotolttene  has 
been  similarly  obtained. 

Reduction  of  triaminotrinitrobenzene  gijM 
pentaminobenzene  (Palmer  and  Jackson,  Ber. 
1»88,  21,  1706;  Palmer  and  Grindiey,  ibid. 
1803,  26,  2304).  T.  S.  M. 

AMINO-ACIDS.  The  amino-acids  may  be 
oonveniently  described  under  the  two  headings 
(a)  Aliphatic  Amino-acids,  and  (6)  Aromatie 
Amino-ftdde, 

Allphatie  Amlnoaelds.  The  amino-fatty 
acids  are  of  great  physiological  importance, 
many  of  them  occurring  in  plant  ana  animal 
oiganisms.  They  are  products  of  proteid  de- 
gradation, and  may  be  obtained  from  proteins 
Dy  heating  with  hydrochloric  acid  or  baryta 
water.  The  general  methods  in  use  for  pre- 
paring these  acids  are : 


ABflNO-ACIDS. 


105 


(L)  Bv  treating  the  monohalogenated  fatty 
acids  with  ammonia: 


CH,a-COOH 
Obloiaoetlo  add. 


■>    CH,(NH,)COOH 
Oiyclne. 

For  ezamplen,  ef.  Fiaoher  and  Smite  (Ber. 
1906,  39,  351). 

(ii.)  By  heatii^^  the  cyanhydrin  ol  an  alde- 
hyds  or  ketone  with  ammonia  and  then  hydro- 
lysing  the  product,  whereby  an  a-amino-acid  is 
produced : 


.OH 


^•"^H<NH. 


CH,CH(NH,)CO,H 
Alanine. 

(ill.)  By  the  reduction  of  the  oyanofatty 
acids  with  nascent  hydrogen  (Zn  or  HCl  or  by 
heating  with  HI) : 

CNCOOH  +  2H,  =  CH,(NH,)CO,H 
CyanoformiG  actd. 

(iv.)  By  Gabriers  phthalimide  reaction  (v. 
preparation  of  amines  4  (6) ),  usina  a  halogen 
6ul»tituted  ester  instead  of  an  alkylhaloid- 

->  cja4<;^^NCH,cooc,H5 

->    C^H^CCOOH),  +  NH,CH,COOO^, 
By  osing  raommalonio  eeter  the  compound 

0JH4<^g^N-CH(C000,H,), 

!•  obtained.  The  remaining  hydrogen  atom  of 
the  methylene  group  is  leplaoeable  by  sodium, 
and  by  reacting  with  a&yl  haloids  on  the 
sodium  oompoumd,  compounds  of  the  general 
formula 


R 


are  obtained.  From  these,  by  suitable  treat- 
ment^ it  18  eai^  to  get  acids  of  the  _general 
formuU  NH,*CHR-COOH  (Sdrenson,  &itral. 
bktt.  1903,  iL  33). 

The  amino-aoids  are  crystalline  bodies  with 
high  melting-points,  usually  soluble  in  water, 
but  sparingly  soluble  in  alcohol  and  ether.  The 
a-  compounds  axe  sweet,  the  /S-oompounds  less 
80,  and  the  y-compounds  not  at  all.  Moulds 
grow  well  in  solutions  of  y-amino-adds,  less  well 
m  /3-acidB,  and  hardly  at  all  in  a-acids.  They 
are  amphoteric,  ».e.  feeble  bases  and  feeble  acids, 
and  there  is  reason  to  think  that  in  solution 
they  exist  as  internal  salts,  e.g.  glycocoU : 

CHf-NH, 

CO— 0. 

They  have,  in  addition  to  the  properties  charac- 
teristio  of  amines  and  of  acids,  the  foUowing 
special  properties : — 

(1)  Their  esters,  with  nitrous  acid,  ffive 
diazo-  compounds,  although  the  acids  themselves 
undergo  with  nitrous  acid  the  normal  reaction 
(rf  aliphatic  amines 

OH,NH,  0H<  I 

I  +HNO,«|     ^N     +2H,0 

COOCjH,  C00C,H, 

NH,<^H,COOH+  HNO, 

=  HOOH,-COOH+H,0 

(2)  Anhydrides,  which  are  in  fact  derivatives 


of  piperazine,  are  formed  by  a  amino-acida,  e.g^ 
glycocoll  giyes  glyddo 

NH— OH,— CO 

I  I 

CO— OH,— NH 
Dlkstoplperazine. 

Heating  with  glycerol  promotea  the  forma- 
tion of  these  anhydrides  (L.  0.  Halliard,  Ann. 
Chim.  1915  [iz.]  3,  48  ;  4,  225). 

Important  amino-acids  aro  glycine,  alanin?, 
phenylalanine,  tyrosine,  leucine,  yaline,  serine, 
cystine,  tryptophane,  histidine,  arj^inine,  lysine, 
aspartic  acid,  and  glutaminio  acid,  which  aro 
described  under  their  respective  headings  {v. 
also  Pbotkins). 

(6)  Aromatto  Amlno-adds.  A  true  aromatic 
amino-acid  such  aa  anthxanilic  acid,  contains 
both  tiie  amino-  and  the  carbozyl-  groups  united 
to  carbon  atoms  in  the  benzene  ring.  laomerio 
with  these  are  adds  which  contain  the  amino- 
l^up  or  the  carbozyl-  group  or  both,  introduced 
mto  tatty  side  chains,  the  last  two  classes  being 
really  substituted  fatty  adds. 

llie  general  methods  in  use  for  preparing 
aromatic  amino-acids  aree 

(i.)  By  reducing  the  correBponding  nitro- 
acids : 

0^4(NOJCOOH(1:2)  -»  0^4(NH,)COOH(l:2) 
o-Ditrobeusolo  acid.  AnthranTllc  add. 

(ii)  By  treating  the  halogen  substituted  esters 
of  oaroozylic  adds  with  potassium  phthalimide 
and  hydrolysing  the  product  with  hydrochloric 
add  at  200^^. 

The  aromatic  amino-acids  are  used  in  the 
preparation  of  azo-dyestufEs  (g.v.). 

a-Aminobenzoic  acid,    AninraniUe  aeid 

C«H4(NH,)C0aH    (1:2) 

It  was  first  obtained  by  heating  indko  with 
caustic  potaah  (Fritzaohe,  Annalen,  39,  §3).  It 
may  be  prepared  by  the  reduction  of  o-nitro- 
benzoic  acia  with  tin  and  hydrochloric  acid 
(Beilstein  and  Kuhlbeiv,  Annalen,  103,  138), 
or  with  dno  and  socuum  bisulphite  (Gold- 
beiger,  Chem.  Zentr.  1900,  ii  1014;  v.  also 
Preuss  and  Binz,  Zeitsch.  ansew.  Chem.  1900,  [16] 
385  and  Bad.  Anil.  u.  Soda  Fab.  Ens.  Pat.  18319 ; 
J.  Soa  Chem.  Ind.  1900,  774) ;  by  heating  o- 
chlorbenzdio  add  and  ammonia  at  125**  under 
pressure  (Farbw.  Meister,  Lucius  und  Brnning, 
D.  R.  P.  145604;  Chem.  Soo.  Abst.  1904,1. 
60);  by  treating  phthalimide  with  sodium 
hypochlorite  and  nydrochloric  add  or  bromine 
ana  caustic  potash  (Hoosewerff  and  van  Dorp, 
Ber.  1891,  Bef.  966 ;  Bad.  AniL  und  Soda  Fab. 
D.  R.  P.  56988 ;  Frdl.  it  546 ;  Amsterdamsche 
Chininefabrik,  Eng.  Pat.  18246 ;  J.  Soo.  Chem. 
Ind.  1891,  831) ;  by  boiling  phthalhydrozylamio 
acid,  formed  by  treating  phthalio  anhydride 
with  hydrozylamine,  with  caustic  soda  or  sodium 
carbonate  {Vie.  Par.  de  Coul.  d' Aniline,  Fr.  Pat. 
318060 ;  J.  Soo.  Chem.  Ind.  1902,  1392 ;  Farbw. 
Meister,  Ludus  und  Bruning,  Eng.  Pat.  1982, 
D.  R.  P.  136788 ;  Basler  Oiemische  Farbw. ; 
D.  R.  PP.  130301,  130302) ;  by  reducing  snlph- 
anthranllio  add  electrolytioaDy  or  with  sodium 
amalgam  (KaOe  and  Co.  D.  R.  P.  129165 ;  Chem. 
Zentr.  1902,  L  1138;  D.  R.  P.  146716;  Chem. 
Soo.  Abst.  1904,  L  169) ;  by*  treating  o-nitro- 
toluene  with  concentrated  alcoholic  or  aqueous 
alkali  (Bad.  Anil.  und.  Soda  Fab.  D.  R.  P. 
1 14839 ;  Chem.  Zentr.  1900,  iL  1892) ;  by  heating 


AMINO-AGIDS. 


iMktoio  acid  with  conoentrated  hydrochloric  acid 
(Kolbe,  3.  pr.  Chem.  [2]  30, 124) ;  and  by  oxidis- 
ing  aoeto-o-toloidide  with  permanganate  in 
presence  of  magneflium  sulphate  and  hydrolyaing 
the  product  (Bad.  Anil,  and  Soda  Fab.  D.  B.  P. 
04629). 

Anthranilio  acid  is  of  great  commercial 
importance,  as  it  is  one  of  the  intermediate 
produota  in  the  manufacture  of  synthetical 
mdigo.  It  crystallises  in  colourleas  plates, 
m.p.  144*6®,  and  is  readilv  soluble  in  alconol  or 
water.  It  condenses  with  formaldehyde,  form- 
ing compounds  which  are  of  use  in  the  prepara- 
tion of  indigo  (Heller  and  Fiesselmann,  Annalen, 
324,  118 ;  Bad.  Anil,  und  Soda  Fab.  D.  B.  PP. 
117924,  158090,  158346;  J.  Soc.  C9iem.  Ind. 
1906,  616).  Beduction  with  sodium  amalgam 
in  hydrochloric  add  solution  yields  o-ammo- 
benzylalcohol  (Langsuth,  Ber.  1906,  2062). 
Concentrated  hydride  acid  decomposes  it  at 
200**  into  ammonia,  carbon  dioxide,  aniline  and 
benzoic  acid  (Kwisda,  Monatsh.  12, 427) ;  whilst 
nitrous  acid  converts  it  in  aqueous  solution  into 
salicylic  acid.  Anthranilic  add  is  employed  in 
the  preparation  of  azo-  dyestuffs  {q.v!)  (v.  also 
Bayer  and  Co.  D.  B.  P.P  58271,  60494,  60600, 
86314 ;  Frdl.  iiL  614  d  aeq, ;  iv.  795). 

The  methyl  ester  of  anthranilio  acid  occurs  in 
Neroli  oil  (oil  of  orange  flowers)  (Walbaum, 
J.  pr.  Chem.  1899,  59,  [6-7]  360).  It  is  piepared 
by  heating  anthranilic  add  with  methyl  alcohol 
and  hydrochloric  acid  (Erdmann,  JEier.  1899, 
1213 ;  D.  B.  P.  110386)  or  from  acetylanthra- 
nilic  add,  meth^  alcohol  and  mineral  adds 
(Eidmann,  D.  B.P.  113942 ;  Chem.  Zentr.  1900, 
ii.  831).  It  IS  a  crystallme  solid,  m.p.  24'5<', 
b.p.  135  *£^  (15  mm.l  The  ethyl  ester  melts  at 
13^  and  boils  at  136^-137*  (13*5  mm.) ;  at  266<>- 
268''  (corr.)  (Frankel  and  Spiro,  Ber.  1895, 1684). 
Aminobenzoic  acid  alkamine  esters  (v.  |»-amino- 
benzoic  add). 

Anthrantl  (jq 

is  the  anhydride  or  lactam  of  anthranilic  add, 
its  constitution  being  still  under  discussion.  It 
is  prepared  by  treating  the  dimerouzy  derivative 
of  o-nitrotoluene  (obtained  by  suspending  o- 
nitrotoluene  in  water  and  heatins  it  with  freshly 
precipitated  mercuric  oxide  and  caustic  soda) 
with  concentrated  hydrochloric  acid  and  decom- 
posing the  product  with  water  (Kalle  and  Co. 
Fr.  Pat.  370522;  D.  R.  P.  194364;  J.  Soc 
Chem.  Ind.  1907,  278 ;  1908,  713) ;  by  heating 
o-nitrotoluene  with  caustic  soda  to  170*  (Kalle 
and  Co.  D.  R.  P.  104811 ;  Chem.  Soo.  Abstr. 
1908,  L  786) ;  by  ti&e  reduction  of  o-nitrobenz> 
aldehyde  with  aluminium  amalgam  (Brfihl,  Ber. 
1903,  3634) ;  and  by  the  oxidation  of  o-anuno- 
benzaldehyde  with  a  neutral  solution  of  Caro*s 
persulphuric  acid  (Bamberger  and  Demuth,  Ber. 
1903,829;  2042). 

Anthranil  ifl  an  oil,  readily  volatile  in  steam, 
posBesnos  a  peculiar  odour,  and  boils  at  210*- 
213*.  It  dissolves  in  alkalis  to  form  salts  of 
anthranilic  add  and  on  treatment  with  acetic 
anhydride  yields  acetylanthranilic  acid. 

m-Amincbemoie  add.  Benxamic  add 
C.H4(NH,)C0JI  (1:3),  is  prepared  by  re- 
ducing m-nitrobenzoic  acid  with  ammonium  sul- 
phide and  subsequently  predpitating  the  add  with 


tartaric  acid  (Holleman,  Bea  Trav.  Chim.  19(& 
[il]  21,  56 ;  V.  also  Geriand,  Annalen,  91,  188). 
It  IS  a  oolourless  crystalline  solid,  m.p.  174* ; 
sparingly  soluble  in  cold,  readily  so  in  hot  water. 
Reduction  with  sodium  amalgam  in  hydro- 
chloric acid  yields  m-aminobenzyl  alcohol  (Lang- 
guth,  Ber.  1905,  2062).  Concentrated  hydriodic 
acid  transforms  it  into  ammonia  and  benzoic 
acid  (Kwisda,  Monatsh.  12,  428).  m-Amino- 
benzoic  acid  is  used  in  the  preparation  of  aao- 
dyestuffs  {q,v,)  (Bayer  and  Co.,  D.  R  PP.  58271, 
59081,  60494,  60500,  63104,  64520.  60445, 
74108,  74516,  78403,  86314;  Frdl.  iii  614 
ei  seq,.  111  et  aeq, ;  iv.  703,  705 ;  CJes.  f.  Chem. 
Ind.,  D.  B.  P.  76127 ;  Frdl.  iiL  746).  Amino- 
benzoic  acid  alkamine  esters  (ti.  ^-aminobensoio 
acid). 

P'Amindbensoie  add  C^4(NH,)C0,H  (1 : 4), 
is  prepared  by  the  reduction  of  p-ni^benzoio 
acid  with  ammonium  sulphide  (Hscher,  Annalen, 
127,  142)  or  with  tin  and  hydrochloric  acid 
(Beilstein  and  Wilbrand,  Anmi.l<<n^  128,  164). 
It  is  a  colourless  crystalline  solid,  m.p.  186*- 
187*,  readilv  soluble  m  water,  alcohol,  or  ether. 
Strong  hydrochloric  acid  at  180*  converts  it 
into  aniline  and  carbon  dioxide  (Wdth,  Ber.  1870, 
105)  and  hydriodic  acid  at  200*  into  ammonia, 
carbon  dioxide,  and  benzoic  add  (Kwisda, 
Monatsh.  12,  428).  j^-Aminobenzoic  add  is 
used  in  the  preparation  d  azo-  dyestuflb  (^.v.) 
(Bayer  and  Co.  I).  R  PP.  58271,  60404,  60500, 
86314;  Frdl.  iiL  614  et  seq.;  iv.  705;  Gee. 
t  Chem.  Ind.,  D.  R  P.  76127 ;  FrdL  iii:  746). 

Many  complicated  alkvl-  and  alkamine  esten 
of  the  aminoDenzoic  adds  have  been  piepared 
and  they  are  claimed  to  be  valuable  anasthetiod 
(Farbw.  Meister,  Ladus,  and  Bruning,  D.  R  PP. 
170587,  172301,  172447, 172568, 170&7,  180201, 
180202,  104748,  Eng.  Pat.  17162,  Fr.  Pat. 
361734,  U.  a  Pat.  812554;  J.  Soc  Chem.  Ind. 
1006,  607 ;  1007,  434 ;  Chem.  Soc  Abstr.  1006, 
L845e<Mf.;  1007,L023;  1008,L638;  Meiek, 
D.  B.  P.  180335;  J.  Soc  Chem.  Ind.,  1008, 
471 ;  Bayer  and  Co.  D.  R  PP.  211801,  218380, 
Eng.  Pat.  4321 ;  J.  Soc  CSiem.  Ind.  1000,  854; 
Chem.  Zentr.  1010,  L  782 ;  Fritzsobs^  S^.  P^t. 
2020,  Fr.  Pat.  308250,  D.  R.  P.  213450; 
J.  Soc  Chem.  Ind.  1000,  814). 

^'Amino-o-tokuc  add  C«Hj*CH.(NH.)(X)aH 
(1:4:2);  m%^  106*.    Obtained  by  the  reduction 
■of  4-nitrotoluic  add  with  thi  and  hydrochlorio 
add  (Jaoobsen  and  Wierss,  Ber.  1883,  1050). 

&-Amino-o4duie  add  C.H,-CH,(NH,}CO,H 
(1:5:2);  m.p.  153*,  is  obtamed  by  the  re- 
auction  of  5-mtrotoluio  add  with  tin  and  hydro- 
chlorio add  (Jacobsen,  Ber.  1884, 164). 

6-AmiiuH>-tdluio  add  C,H,-CH,(NH,XX),H 
(1:6:2).  Method  of  preparation  as  above; 
ULp.  101*  (J.  and  W.  l.e.\ 

2'Amino-m-U)luic  add  CgH,-CH,(NH,)00,H 
(1:2: 3).  Method  ol  preparation  as  above ; 
m.p.  132*  (Jacobsen,  Ber.  1881,  2364),  172* 
(Jfirgens,  Ber.  1007  4400). 

4-Anuno-^n4oUUe  add  {Methf^nihnnUUc 
add)  C,H,-CH,  (NH,)O0,H  (1:4: 3).  Obtained 
by  reduction  of  4.mtro-nt-tQluic  acid  with  tin 
and  hydrochlorio  add  (Jacobsen,  Ber.  1881, 2354) 
or  by  treating  p-methylisatoic  add  with  oonoen- 
trated  hydrochloric  add  (Panaotovio,  J.  pr. 
Chem.  [2]  33,  62) ;  m.p.  172*  (BhrHch,  Ber.  1001, 
3366),  175*  (Findeklee,  Ber.  1005.  3533). 

Q'AmiiuMnMuic  add  C,H,-CH,(NH,)00,n 


jiAHINO  CARYAOROU 


197 


(1:6:3);  m.p.  167^  Obtainad  by  redottion 
of  6-iiitro-fy»-toluio  acid  (Beiktein  and  Kreusler, 
Annalcm  144   147  )• 

2-Am%nthp4auie  aciaC,H,-CH,-(NH,)<X),H 
(1:2:4);  m.p.  164^-165**.  Method  of  preparation 
as  above  (Aniens,  Zeitaoh.  f.  Ghemie,  1869,  104). 

^'Amiruhp-tcluicaeid  {Homo^ntkranilic  add) 
CeH,'CH,(NHg)00,H  (1:3:4);  m.p.  177*. 
Method  of  preparation  as  above  (Niementowski 
and  Rozanski,  Ber.  1888,  1997 ;  Noyes,  Amer. 
Chem.  J.  10,  479). 

I'-AmiTUhO-toluic  acid  ( BemylamiTte-o-car- 
hoxffiic  add)  NH.-CH.O.H^-COjH  (1:2).  Ob- 
tained bv  digesting  1  part  of  o-oyanobenzyl- 
phthalimide  witJi  4  parts  of  concentrated  sulphuric 
acid  ((Gabriel,  Ber.  1887,  2231 ).  Crystalline  non- 
volatile  solid. 

V'AmifKh^fi-^oluic  add  iBemylamine-m-car- 
boxylic  add  KHsOHi-CcH^-COsH  (1:3);  m.p. 
215^-218^  By  heating,  at  200''  a  mixture  of 
2  grams  fiMnranobenzytphthaUmide  and  10  c.c. 
concentrated  hydrochloric  acid  (Reinglass,  Ber. 

1891,  2419). 

V'Amino^-tduic  add  (Benzylamine-p-car' 
&oi^u:ac»d)NH.-CH,<:;.U4-CO,H(l:4).  Method 
of  preparation  as  above  (Gunther,  Ber.  1890, 
1060).     Crystalline  solid. 

Z-Amino-a-toluie  add  (2'Amin6phenylace- 
<*ciic«a)NH,'C,H40H,<X),H  (1 : 2)  is  not  known 
in  the  free  state;  all  attempts  to  prepare  it 
result  in  the  formation  of  its  anhydride  ,ozindole. 

Oxindoie 


C.H.<^'>CO 


is  obtained  by  treating  2-nitro-a-toluic  acid 
with  tin  and  hydrochloric  acid  (Bayer,  Ber. 
1878,  583),  or  by  leduoing  diozindole  with  tin 
and  hydrochloric  acid,  or  with  sodium  amalgam 
(Bayer  and  Knop,  Annalen,  140,  29).  Crystal- 
lises in  colourless  needles ;  m.p.  120°. 

3'Amina-a-toluic  add  {S-Aminophenylace- 
tic  add)  NHaC^H^-CH.CO^  (1 : 3).  Obtained 
by  reducing  3-nitro-a-toluic  acid  with  tin  and 
hydrochloric  acid ;  m.p.  148°-149''  (Qabriel  and 
Boigmann,  Ber.  1883,  2066). 

i-AnUno-a-ioluic  add  (4i-Aminophenylaceiic 
add)  NH,C,H4CH,C0,H  (1:4).  Method  of 
preparation  as  above  (Radziozewski,  Ber.  1869, 
So&i;  m.p.  199^-200*'  (Bedson,  Chem.  Soc. 
Trans.  1880,  92). 

a-Amino^enyJaceticadd  C«H5'CH(NHt)C0tH. 
Obtained  oy  heating  a-phenylbromacetic  acid 
with  aqueous  ammonia  at  100*^-1 10®  (Stiickenius, 
Ber.  1878,  2002);  m.p.  266°  (Tiemann,  Ber. 
1880,  383).  Sublimes  without  melting  at  266° 
(Elbers,  Annalen,  227,  344).  T.  S.  M. 

2.AMIN0A1ITHRAQUIN0NE 

CO 


CO 


red  needles;  m.p.  302°.  Is  employed  in  the 
manufacture  of  mdanthrene  and  indanthrene 
dyes  (v.  Indamthbsnb).  It  is  made  technically 
by  heating  under  pressure  at  170°,  a  mixture  of 
sodium  anthraqumone-2-sulphonate  with  an 
aqueous  solution  of  beuium  chloride  and  dilute 
ammonia.  The  filtered  product  is  washed  with 
water,  dilute  hydrochloric  acid,  and  weak 
Bodiom  hydroxide  solutions,  and  is  crystallised 


from  chlorobenzene  (Farbw.  vorm  Meister, 
Lucius  und  Bruning,  D.  R.  P.  267212). 

Or  the  sodium  anthraquinone-2-8ulphonate, 
in  the  form  of  a  paste,  is  mixed  with  manganese 
dioxide  and  ammonia  solution,  and  heated  at 
200°.  The  product  is  treated  with  sulphurous 
acid  or  acia  sodium  sulphite  to  remove  the 
manganese,  and  dried. 

A  mixture  of  sodium  dichromate  and  ammo- 
nium chloride  may  be  substituted  for  the 
manganese  dioxide  (Bad.  Anilin  und  Soda  Fab. 
D.  R.  P.  266616).  For  details,  see  Cain's 
Intermediate  Products  for  Dyes. 

Alternative  methods  are  to  condense  m- 
aminobenzoylbenzoic  acid  by  means  of  sulphuric 
acid  (Basle  Chem.  Works,  D.  R.  P.  148110). 
or  the  carbamide  derivative  of  the  same  acid 
(Akt.  fur  Anilinfab.  Eng.  Pat.  8914,  1914) ;  by 
hydrolysing  2-p-toluenesulphonylaminoanthra- 
quinone  JUUmann,.  D.  R.  P.  224982) ;  by  the 
action  ox  ammonia  and  oxidising  agents  on 
me«ohalogen  anthracene-2-suIphonic  acids  (Bad. 
Anilin  und  Soda  Fab.  D.  R.  P.  288996) ;  or  by 
heating  2-chloroanthraquinone  with  ammonia 
(Farbenfab.  vorm.  F.  Bayer  and  Co.  D.  R.  P. 

295624). 

AMIMOAZOBENZENE    {AnUine   yeUow)   v. 

AZO-  COLOURING  ICATTBB. 

o-AMINOAZGTOLUENE 

CH,  CH, 

may  be  made  by  heating  to  25°-30°  o-toluidine 
with  an  aqueous  solution  of  sodium  nitrite 
and  hydrochloric  acid  in  a  lead-lined  iron  pan 
fitted  with  a  jacket  for  water-cooling  and  a 
stirring  arrangement.  The  excess  of  toluidine 
is  removed  by  neutraUsing  with  hydrochloric 
acid  when  the  o-aminoazotoluene  hydrochloride 
separates  out.  It  is  emploved  in  the  manu- 
facture of  cloth  reds  and  safranine,  and  is  sold 
as  Yellow  Fat  colour  and  as  Fast  Azo-  Garnet 
base  (c/.  Cain's  Intermediate  Products  for  Dyes). 

The  base  is  sparingly  soluble  in  water, 
readily  soluble  in  sdcohol  and  ether ;  m.p.  100°. 

m-AMIMOBENZALDEHTDE  is  prepared  bv 
heating  a  mixture  of  w-nitrobenzaldehvdo  with 
a  solution  of  sodium  hydrogen  sulphite  and 
ferrous  oxide,  made  by  boihng  a  solution  of 
ferrous  sulphate  with  chalk.  After  filtration 
the  solution  is  acidified  and  boiled  to  expel 
sulphur  dioxide  (Farbw.  vorm.  Meister,  Lucius 
und  Briining,  D.  R.  P.  62960,  66241).  Or  the 
nitrobenzalc&hyde  may  be  headed  with  an 
aqueous  solution  of  sodium  hyposulphite,  the 
s^ution  cooled,  mixed  with  hydrochloric  acid, 
again  boiled  to  expel  sulphur  dioxide.  On 
cooling,  the  anhydro-  derivative  of  o-amino- 
benzaldehyde 


0^«  ■•  ""O 

NH.  CBO 


separates  out  (Farb.  Fabrik  vorm.  F.  Bayer  und 
Co.  D.  R.  P.  218304  ;  cf.  Benzaldehyde,  Pertw 
tivea  of ;  and  Cain's  Intermediate  Products  for 
Dyes). 

a-AMINOCAPROIC  ACID  v.  Lhucine. 

p.AHINOCARVACROL.  A  photographic 
developer,  resembling  metol  and  p-aminophenol 
in  dieveloping    properties;    its  solution  keeps 


108 


AMINO  OARVAOROL. 


better  than  that  of  the  latter.  Obtained  by 
reducing  an  ammoniacal  eolation  of  p*nitroso 
carvacrol  by  hydrogen  sulphide  when  p-amino 
carvacrol  separatss  in  ooloarlese  leaves  (Brit.  J. 
Phot.  1919,  66,  634). 

p-AHIMODIPHENTLAMINE 


NH.<3>NH<(J> 


m.p.  76° ;  b.p.  364°  (in  hydrogen),  is  prepared 
by  heating  tcM^ether  in  an  oil-bath  at  180°-186° 
a  mixture  of  sodium  2-ohloro-6-mtrobenzene- 
Hulphonate  (from  p-chloronitrobenzene),  elyoerol, 
chalk,  and  aniline.  After  dilution  with  water, 
sodium  carbonate  is  added,  and  the  excess  of 
aniline  removed  by  steam  distillation.  After 
filtration  sodium  p-nitrodiphenylamine-o-sul- 
phonate  crystallises  out.  This  is  warmed  with 
nydrochlonc  acid,  and  nitrodiphenylamine- 
sulphonio  add  ia  formed  as  a  brownish-red  oil, 
which  by  further  heating  is  converted  into  the 
crystalline  p-nitrodiphenylamine.  This  is  sepa- 
rated, treated  with  ammonia,  washed,  and  dried. 
To  reduce  it,  it  is  dissolved  in  alcohol,  ammo- 
nium chloride  added,  heated  to  boiling,  and 
mixed  with  zinc-dust,  and  a  small  quantity  of 
a  solution  of  sodium  hydrogen  siuphite,  the 
whole  filtered  into  60  p.c.  sulphuric  acid,  when 
insoluble  aminodiphenjoamine  sulphate  separates 
out.  By  treating  this  salt  with  water  and 
ammonia  the  free  base  is  obtained.  (For 
details,  ^u  Cain's  Intermediate  Products  for 

AHIMOETHTL  ALCOHOL  v.  Caouan. 
4-/S.AHIH0ETHYLaLT0XALIllE  v-  Eboot. 
3-A1IUIO-7-HTDROXYPHBNAZIHB 

N 


=oU\A/^« 


^ 


is  obtained,  according  to  Nieteki  and  Simon 
(Ber.  1896,  28,  2974),  by  heating  an  aaueous 
solution  of  2  : 4-diamino-4'-hydroxydiphenyl- 
amine  hydrochloride  with  unmonia  and  man- 
sanese  oxide  until  the  blue  colour  disappears, 
filtering,  and  acidifying  with  hydrochlono  acid, 
when  the  phenazinenydrochloride  separates. 
The  free  baae  is  obtained  by  treating  the  hydro- 
chloride with  sodium  carbonate. 

UUmann  and  Gnaedinger  (Ber.  1912,  46, 
3442)  blow  air  through  a  solution  of  m-phenylene- 
diamine  sulphate  and  p-aminophenol  hydro- 
chloride, containing  sooium  hydroxide.  The 
compound  NH  :  C,H,(NH,)  :  NC,H40H,2H,0 
is  oDtained,  which,  on  solution  in  ammonia, 
warmed,  and  again  treated  with  air  until  the 
blue  colour  changes  to  red,  yields,  after  filtration 
and  addition  of  hydrochloric  add,  the  phenazine 
hydrochloride. 

3-Amino-7-hydroxyphenazine  melts  at  360°, 
and  dissolves  in  alcohol  or  ether  with  a  green 
fluorescence. 

l-AMIN0.2.MBTHyLAIITHRAQUIN0NB 

CO    NH, 
CH, 


000 


■^' 


Obtained  by  adding  sodium  nitrate  to  a  cooled 


solution  of  methyUnthraquinone  in  sulphurio 
add  and  reducing  the  l-nitro-2-methylanthra- 
quinone  so  formed  by  sodium  sulphide  or 
stannous  hydroxide;  uld.  202°.  Insoluble  in 
water;  readily  soluble  in  alcohol,  ether,  benzene, 
or  acetic  acid  (Bomer  and  Link,  Ber.  1883,  16, 
696;  SchoU  and  Holdermann,  Ber.  1907, 
40,  1696). 

AMINOIIAPHTHOL  SULPHONIO  AGID6  «. 
Nafhthalbne. 

AMINONAPHTHOPHENAZINE  v.  Azorss. 

f>.AMINOPHENOL  HO<^^~NnH,  may  be 

made  by  reducing  p-nitrophenol  with  tin  and 
hydrochloric  add  in  presence  of  sulphuric  add 
when  p-aminophenol  sulphate  separates.  The 
base  is  liberated  by  sodium  carbonate,  add 
sodium  sulphite  being  added  to  {prevent  oxida- 
tion. The  reduction  may  also  be  made  by 
sodium  hyposulphite  in  allaline  solution,  or  Inr 
iron,  ferrous  chloride,  and  hydrochloric  add, 
or  by  the  catalytic  action  of  nickd. 

p-Aminophenol  may  also  be  prepared  by 
reducing  j9-azophenol  OH'CcH4'Kt'C«H4'OH, 
with  stannous  chloride  or  zinc-dust  and  sodium 
hydroxide;  or  by  the  action  of  sodium  hypo- 
sulphite or  sodium  sulphide  on  a  hot  alkaline 
solution  of  p-hydroxyazobenzene.  Thep-amino- 
phenol  sulphate  may  be  obtained  from  a  soluticm 
of  nitrob^zene  in  sulphuric  acid  by  the  action 
of  zinc-dust,  or  by  electrolytic  reduction  using 
carbon  cathodes  (Darmstadter,  B.  B.  P. 
160800) ;  or  a  copper  cathode  in  a  lead  cylinder 
as  an  anode  (Soc.  Chem.  Ind.  Bade,  Eng.  P»t. 
18081,  1916). 

^  Aminophenol  forms  white  crystalline  plates 
mdting  at  184°.  It  rapidly  oxidises  in  air. 
Comes  into  commerce  as  iJrsol  P  for  dyeing  fur, 
and  as  a  photographic  devdoper  under  the  name 
of  Rodifud. 

2.A1IDIOPHENOL-4-SULPHONIC  ACID 

NH, 
OH<^^SO,H 

Obtained  by  nitrating  phenol-p-sulphonio  add 
with  nitric  add  and  roducins  with  iron ;  or  by 
sulphonating  o-aminophenoT;  or  by  fusing 
anJiine-2 : 6-disulphomc  acid  with  sodium  hy- 
droxide. 

AMINOPHENOPHENANTHRAZIME  v. 

AziNKS 

AMiNOPHENYLACEnC   ACID   v.    AiaNO- 

ACIDS  (AbOHATIO). 

«.    and    iS-AMUfOPROPIONIG    ACIDS    v. 

Alanine. 

AMINOSALICYLIC  ACID  v,  Bauoylio  agid. 

d-AMINO-Mo-VALERIC  ACID  t;.  Vaxjnb. 

AMLA  (Beng.),  AMUKA  (Hind.),  AMUKU 
(Ass.),  OWLA  (Mechi),  NELU  and  TOPPDIELU 
(Tam.).  A  eupnorbiaceous  Indian  tree,  PfutUaU' 
thtu  emblica  (linn.),  the  fruits  of  which  {AkbUe 
myrcMana)  are  used  in  a  fresh  condition  as  a 
laxative,  and,  when  dried,  as  an  astringent 
(Dymock,  Pharm.  J.  [3J  10,  382).  The  fruits 
are  also  pickled  and  eaten,  and  used  for  tanning 
and  dyeinff . 

AMMOlf  AL  V.  ExpiiOsiyjES. 

AMMONIA.  VoUaOe  alkdU,  albaUne  air, 
9pirii  oj  harUikom,  Solutions  of  ammonia  have 
been  known  from  very  early  times,  bat  the 
substance  itaeU  was  fint  dearly  recognised  by 


AMMONU. 


loa 


who  obtained  it  by  haatinjg  the  aqueouB 
soiutiion  and  collecting  the  gas,  which  he  termed 
alkaiine  air,  over  mercury.  Scheele  proYed.that 
it  contained  nitrogen ;  and  Berthollet»  and  more 
aoonrately  Anstin,  demonstrated  ita  real  nature, 
and  determined  the  proportiona  of  its  con- 
Btitnento. 

Ammonia  (or  ita  salta)  is  found  in  small 
quantitieB  in  the  air,  and  in  most  natural  water ; 
in  the  juice  of  pkntfi,  in  most  animal  fluids,  in 
many  soils,  ana  in  a  few  minerals,  ochres,  clays, 
maiUy  Ac.  Ammonia  can  be  obtained  syntheti- 
cally in  small  quantity  by  the  passage  of  elec- 
trical discharges  through  a  mixture  of  nitrogen 
and  hydrooen  (Donkin,  Pogg.  Ann.  21,  281) ;  or 
heating  the  mixture  to  a  high  temperature 
(Haber,  Zeitaoh.  Elektrochem.  19U,  20,  597; 
Maxted,  Chem.  Soa  Trans.  1918,  113,  168,  386; 
1919,  115,  113;  J.  Soc.  Ghem.  Ind.  1918,  37, 
232) ;  or  as  nitrite  b^  the  action  of  a  strong  in- 
duction spark  on  a  mixture  of  nitrogen  and  water 
▼apour  (Thdnard,  Compt.  rend.  76,  983) ;  or  as 
chloride  by  sparking  a  mixture  of  hydrogen, 
nitrogen,  and  hydrogen  chloride  (Deyille,  Compt. 
rend.  60,  317) ;  or  b^  the  action  of  heated 
spongy  platinum,  pumice,  Ac,  on  a  mixture  of 
hydrogen  and  nitnc  acid. 

For  laboratory  purposes  the  gas  is  usually 
prepared  by  heating  a  mixture  of  ammonium 
chloride  or  sulphate  with  slaked  lime,  or  by 
gently  wanning  the  concentrated  solution,  and 
arymf  the  gas  over  quicklime.  (For  the  pre- 
paration of  the  chemically  pure  gas,  see  Stas, 
Zeitsch.  anal.  Chem.  6,  423.) 

Ammonia  is  a  colourless  gas,  having  a  very 
pungent  characteristic  smdl,  and  is  poisonous 
when  breathed  in  quantity,  destroying  the 
mucous  membrane.  It  has  a  sp.gr.  of  0*5967 
(air  =  1),  1  litre  of  the  gas  at  0^  and  760  mm. 
weighing  0*7708  gram,  and  readily  liquefies  on 
compression,  the  critical  temperature  beinff 
132'9''d:0'l,  and  the  critical  pressure.  112-3db0'l 
atm.  (Cardoso  and  Gillay,  J.  chim.  phys.  1912, 
10,  514).  Its  critical  density  Ib  0*2362  (Ber- 
thoud).  Liquid  ammonia  is  colourless  and  very 
mobile,  and  has  a  sp.gr.  at  074''  of  0*6385 
(IKeterici),  0*6388  (Brewes),  the  coefficient  of 
expansion  being  very  high  and  increasing 
rapidly  with  the  temperature.  It  boils  under 
atmospheric  pressure  at  —33*2-34*6®  (Burrell 
and  Robertson),  and  freezes  to  a  white  crystal- 
line solid  at  —77®  (Keyes  and  Brownlee), 
—77®  (BriU),  the  vapour  pressure  being  as 
follows  (Regnault,  J.  1863,  70)  :— 

at  -30®  1*14  atm.        at  0®  4*19  atm. 
20®  1*83    ..  ..  10®  6*02 


tt 


ft 


-10®  2-82 


» 


>» 


9t 


>» 


20®  8-41 


*f 


»> 


The  dependence  of  the  vapour  pressure  on 
temperature  down  to  the  freezing-point  may  be 
expressed  by  the  equation :  log  p  = — 1969 '66/T 
+  1619785  -  00423858T  +  6*4131  +  10-*T» 
-3-2716  xlO-*T». 

Its  latent  heat  of  evaporation  decreases  from 
333*0  Cal.  at  -42®  to  252*6  Cal.  at  49®.  The 
variation  of  the  latent  heat  with  the  tempera- 
ture may  be  expressed  by  the  formula 

L  »  32'968Vi33-9-O'5985(133-0) 

in  which  6  represents  the  actual  temperature  and 
133  the  critical  temperature.  The  specific  heat 
of  saturated  ammonia  vapour  expressed  in 
joules  per  gram  per  degree  varies  from  -4*42 


at  -45®  to  -3-36  at  45®.  To  reduce  these 
numben  to  20®  Calories,  they  must  be  divided 
by  4-163  (Osborne  and  van  Busen,  J.  Amer. 
Chem.  Soa  1918,  40,  14).  The  specific  heat  of 
liquid  ammonia  increases  from  1-058  at  —45® 
to  1  '173  at  45®.  Its  dependence  on  temperature 
may  be  expressed  by  the  equation: 

e  =  0*7498  -  0*0001369  -f  4-0263  V 133-0 

in  which  c  is  expressed  in  terms  of  the  20* 
Calorie  and  $  ib  the  temperature  (Osborne  and 
van  Duser,  {.c).  Liquid  ammonia  is  produced 
commeroially  in  large  quantity  for  employment 
in  freezing  machines.  In  many  of  its  physical 
properties  the  liquid  resembles  water,  and  it  acts 
as  a  solvent  for  a  large  number  of  substances. 

Ammonia  gas  bums  with  difficulty  in  the 
air  when  oolt^  but  inflames  more  readily  on 
heating,  and  still  more  readily  in  oxygen, 
giving  a  greenish-yellow  flame  of  high  tempera- 
ture. In  presence  of  suitable  catal^ts,  such  as 
copper,  iron,  nickel,  and  especially  platinum, 
ammonia  is  oxidised  by  o^gen  at  lower  tem- 
peratures with  production  of  oxides  of  nitrogen, 
the  manufacture  of  nitric  add  from  ammonia  by 
Ostwald's  process  (Eng.  Pat.  698,  1902)  being 
carried  out  in  this  manner.  A  number  of  the 
elements,  when  heated  in  ammonia  gas,  yield 
corresponding  nitrides  :  boron,  magnesium,  and 
titanium  beins  especiallv  active  in  this  res^t, 
whilst  the  auali  metals  give  rise  to  amides. 
With  carbon  at  tempentures  above  750® 
ammonia  is  partly  dissociated,  and  partly 
converted  into  hy<uooyanic  acid,  the  presence 
of  the  latter  in  crude  coal  gas  being  largely  due 
to  tins  reaction. 

Many  salts  combine  with  ammonia  to  form 
stable  compounds  at  the  ordinary  temperature, 
the  ammonia  playing  the  same  part  as  water  of 
crystallisation.  It  is  evolved  on  heating,  liauid 
ammonia  having  been  first  obtained  by  Faraday, 
in  1823,  bv  warming  the  compound  with  silver 
chloride  2AgCl,3NH„  in  a  sealed  tube. 

The  action  of  heat  upon  ammonia  has  been 
investigated  by  Ramsay  and  Young  (Chem.  Soa 
Trans.  45,  92),  Perman  (Proc.  Boy.  Soc.  74, 
110;  76A,  167),  Haber  and  v.  Oordt  (Zeitsch. 
anorg.  Chem.  44,  341),  and  Nemst  and  Jost 
(Zeitsch.  Elek.  13,  521).  Under  atmospheric 
pressure,  decomposition  commences  at  tempera- 
tures below  50(r,  its  extent  increasing;  rapidlv 
with  the  temperature,  but  the  speed  with  which 
equilibrium  ia  attained  between  undecomposed 
ammonia  and  nitrogen  and  hydrcwen  varies 
greatly  according  to  the  nature  of  the  surfaces 
with  which  the  gases  are  in  contact.  Glass  is 
verv  inactive,  but  porcelain  and  many  metals 
and  their  oxides  have  a  very  strons  accelerating 
effect  In  presence  of  the  latter  aecomposition 
becomes  nearly  complete  at  630®  under  atmo- 
spheric pressure,  but  the  last  traces  do  not  dis- 
appear even  at  1000®.  (Conversely,  in  presence 
of  iron  as  catalyst,  Haber  and  v.  Oordt  find  that 
at  1000®  traces  of  ammonia  are  formed  from 
nitrosen  and  hydrogen  at  atmospheric  pressure, 
and  Nernst  and  Jost  have  found  that  small 
quantities  are  formed  at  the  same  tempera- 
ture under  the  greater  pressure  at  50-70  atm. 
At  temperatures  of  500^-560®  under  200  atm. 
pressure,  in  presence  of  metallic  osmium  or 
uranium,  nitrogen  and  hydrogen  combine  to  a 
considerable  extant  (see  below). 


200 


AMMONIA. 


It  has  been  shown  by  Regoner  (Sitzongsber, 
K.  Akad.  Wiss.  Berlin,  19&,  1228),  and  by 
D.  Berthelot  and  Gaudechon  (Compt.  rend.  1913, 
166, 1243),  Coehn  and  Pringent  (Zeitach.  Elektro- 
ohem.  1914,  20, 276)  that  ammonia  is  completely 
decomposed  by  ultra-violet  light. 

Under  certain  conditions  a  mixture  of  air 
and  ammonia  gas  may  be  exploded  by  an  electric 
spark  (Schlumberger  and  Piotrowski,  J.  Gasbel. 
1914,  67,  941).  Fires  which  have  oocorred  in 
the  neighbourhood  of  refrigerating  machines 
have  been  attributed  to  ignition  of  mixtures  of 
air  with  ammonia,  or,  according  to  Behr,  to  the 
ignition  of  hydrogen  formed  in  the  machine  by 
decomposition  of  ammonia  at  the  high  tempera- 
ture and  pressures  produced  by  starting  with 
a  closed  discharge  stop- valve  (Cattaneo,  kitsch, 
ges.  Kalte-Industrie). 


Ammonia  gas  is  veiy  soluble  in  water, 
alcohol,  ether,  and  man^  salina  solutions,  the 
aqueous  solution  (caustic  ammonia  or  U^ttar 
ammonicB)  being  of  great  commercial  importance. 
One  gram  of  water  at  (f  and  760  mm.  absorbs 
1148  o.c.  or  0'876  gram  of  ammonia,  at  10^ 
0*679  gram,  at  20°  0*626  gram,  at  SO"*  0*403  gram, 
and  at  100""  0*074  gram  (Bosooe  and  Dittmar, 
Chem.  Soc.  Trans.  12,  128 ;  Sims,  Chem.  Soo. 
Trans.  14,  1 ;  see  also  Perman,  Chem.  Soc. 
Trans.  79.  718;  83,  1168).  In  the  act  of 
solution  much  heat  is  evolved,  and  according  to 
Thomson,  NH,+aq.  =  8430  cals. 

The  density  of  aqueous  solutions  of  ammonia 
of  vaiying  strength  is  shown  in  the  accompany • 
ing  table,  according  to  the  determinations  of 
Lunge  and  Wiemik. 


DxNSiTT  OF  Aqusotts  Solutioks  ov  Ammonia  at 

16*  (LUNOK 

AND    WlKBNIK). 

Sp4r. 

KHs 

1  litre  con- 

CorrectioQof 

8p.gr. 
0-940 

NHs 

lUtieoon- 

Correction  of 

p.c. 

tainsKHsS* 

Bp.gr.  for  ±1° 

p.c. 

tsiiuNHsg. 

8p.gr.  for±l® 

1-000 

0-00 

00 

0-00018 

16-63 

146-9 

0-00039 

0-998 

0-46 

4-6 

0-00018 

0-938 

16-22 

1621 

0-00040 

0*996 

0*91 

9-1 

0*00019 

0*936 

16-82 

167-4 

0*00041 

0-994 

1-37 

13-6 

000019 

0-934 

17-42 

162-7 

0-00041 

0*992 

1-84 

182 

0-00020 

0-932 

18-03 

168-1 

0*00042 

0*990 

2-31 

22-9 

0-00020 

0-930 

18-64 

173-4 

0-00042 

0-988 

2*80 

27*7 

0-00021 

0-928 

19-26 

178-6 

0-00043 

0*986 

3*30 

32-6 

0-00021 

0-926 

19-87 

184-2 

0-00044 

0-984 

3-80 

37-4 

0-00022 

0-924 

20-49 

189-3 

0*00046 

0*982 

4-30 

42-2 

0-00022 

0-922 

21-12 

194-7 

0-00046 

0-980 

4-80 

47-0 

0-00023 

0-920 

21-76 

200-1 

0-00047 

0-978 

6-30 

61-8 

000023 

0-918 

22*39 

206-6 

0-00048 

0*976 

6-80 

66-6 

0-00024 

0-916 

23-03 

210-9 

0-00049 

0*974 

6-30 

61-4 

0-00024 

0-914 

23-68 

216-3 

0-00060 

0-972 

6-80 

661 

0-00026 

0-912 

24  33 

221-9 

0-00061 

0*970 

7-31 

70-9 

0-00026 

0-910 

24-99 

227-4 

0-00062 

0*968 

7-82 

76*7 

0-00026 

0-908 

26-66 

232-9 

0-00063 

0*966 

8*33 

80-6 

0-00026 

0-906 

26-31 

238-3 

0*00064 

0*964 

8-84 

86*2 

0-00027 

0-904 

26-98 

243-9 

0-00065 

0-962 

9-36 

89*9 

0-00028 

0-902 

27-66 

249-4 

0-00066 

0*960 

9-91 

961 

0-00029 

0*900 

28-33 

266-0 

0-00067 

0-968 

10-47 

100-3 

0-00030 

0-898 

29*01 

260-6 

0-00068 

0-966 

1103 

106*4 

0-00031 

0-896 

29-69 

266-0 

0-00069 

0-964 

11-60 

110-7 

0-00032 

0-894 

30-37 

271-6 

0-00060 

0*962 

1217 

116-9 

0-00033 

0*892 

31-06 

277-0 

0-00060 

0-960 

12-74 

121*0 

0-00034 

0-890 

3176 

282-6 

0-00061 

0*948 

13-31 

126-2 

0-00036 

0-888 

32-60 

288-6 

0-00062 

0-946 

13-88 

131-3 

0-00036 

0-886 

33*26 

294-6 

0-00063 

0-944 

14-46 

136-6 

0-00037 

0-884 

34-10 

301-4 

0-00064 

0*942 

16-04 

141-7 

0-00038 

0-882 

34-96 

308-3 

0-00065 

The  solution  is  very  strongly  alkaline,  and 
unites  with  acids  to  form  the  ammonium  salts, 
and  it  is  frequently  supposed  that  the  solution 
contains  ammonium  hycuoxide  NH^-OH,  corre- 
sponding to  NaOH  and  KOH.  The  evidence 
for  this  view  is  not  altogether  conclusive,  and 
the  physical  properties  of  the  solution  at  the 
ordinarv  temperature  are  in  some  respects 
opposea  to  uie  presence  of  the  compound 
NH4OH,  and  in  favour  of  the  supposition  that 
the  ammonia  is  dissolved  as  such.  At  very  low 
temperatures,  however,  Rupert  (J.  Amer.  Chem. 
Soc.  31,  866 ;  32,  748)  has  shown  that  two 
definite  hydrates  exist,  the  freeadng-point  curve 
of  mixtures  of  ammonia  and  water  in  varying 
proportions  showing  two  well-defined  minima  at 
--87^ and  —94°  respectively,  the compositionat 


these  two  points  corresponding  to  the  formula 
NH„H,0  and  2NH.,H,0.  The  first-named 
forms  small  colouriess  crystals  resembling  those 
of  sodium  and  potassium  hydroxide;  and  the 
latter,  larger  needle-shaped  crystals.  Whether 
these  are  true  hydrates  or  are  to  be  re- 
garded as  ammonium  hydroxide  NH,OH  and 
ammonium  oxide  (NH4)20,  is  at  present 
uncertain. 

The  aqueous  solution  of  ammonia  also  dis- 
solves many  metaUic  oxides  and  hydroxides, 
such  as  Ags0,Cu(0H)|,  as  well  as  many  salts 
which  are  insoluble  in  water,  such  as  silver 
chloride  and  phosphate,  and  cuprous  chloride, 
and  also  acts  as  a  solvent  for  many  fats  and 
resins.  The  solution  of  cupric  hydroxide  in 
ammonia  is  of  considerable  commereial  impor- 


AMMONIA.. 


201 


tanoe,  as  it  is  a  solvent  for  oelluloee,  and  is 
used  in  Lurse  qnantities  in  the  manufaotuie  of 
artifioial  silK. 

I.  TMbnleal  sourees  of  ammonia.^  Ammonia 
is  formed  in  nature  chiefly  during  the  decay  of 
nitrogenous  oiganio  substances,  and  conse- 
quently exists  in  considerable  quantity  both  in 
the  sou  and  the  atmosphere.  Whilst  this  is  of 
the  greatest  importance  for  agriculture,  it  is 
only  possible  in  very  exceptional  cases  to 
utilise  this  source  for  the  manufacture  of  am- 
monium salts,  the  greater  proportion  of  the 
world's  production  being  obtained  by  the 
deetruotiye  distillation  of  nitrogenous  organic 
matter,  chiefly  coal. 

A.  NcAurai  occurrence  of  ammoniacal  com' 
pounds  in  quantity  of  commercuU  importance, — 
Ammonium  carbonate  has  been  found  in  guano 
deposits  on  the  West  Coast  of  South  America, 
and  has  been  imported  into  Europe,  a  sample 
imported  into  Germany  in  1848  consistmg 
eeaenluUly  of  ammonium  bicarbonate  mixeS 
with  some  insoluble  matter.  Ammonium  sul- 
phate is  contained  in  the  Tuscan  '  soffioni,*  and 
IS  there  obtained  in  considerable  quantity  as  a 
by-product  in  the  jnanufacture  of  boric  acid. 
Ammonium  chloride,  together  with  sulphate,  is 
Mmetimes  found  in  the  neighbourtood  of 
volcanoes. 

B.  Synthetic  processes  for  production  of 
ammonia. — ^Very  many  attempts  have  been 
made  to  effect  the  manufacture  of  ammonia  from 
atmospheric  nitrogen  and  hydrogen,  and  a 
large  number  of  processes  with  this  object  have 
been  patented,  but  until  recently,  no  method 
which  has  been  proposed  has  proved  successful 
on  a  oommercial  scale,  for  although,  as  stated 
above,  nitrogen  and  hydrogen  comoine  together 
to  a  slight  extent  to  form  ammonia,  when  heated 
together  under  suitable  conditions,  the  yield 
at  high  temperatures  was  so  small  that  the  cost 
of  production  would  be  prohibitive.  With 
many  of  the  methods  proposed — such  as  those 
of  Swindells  (Eng.  Pat.  June  21, 1876),  Riokman 
(Eng.  Pat.  3341,  1878),  Glover  (Eng.  Pat.  1890, 
1880),  Solvay  (Bull.  Soc.  chim.  25,  527), 
Wagner  (Jahiesbericht.  1876,  444),  Bassett 
(Eng.  Fat.  4338,  1879)— it  Ib  very  doubtful 
whether,  in  fact,  any  ammonia  is  produced 
synthetically,  the  ammonia  obtained  being 
more  probably  all  derived  from  the  nitrogen 
present  in  the  coal  or  coke  employed  in  each  of 
these  processes.  The  processes  of  Johnson 
(Ghem.  News,  43,  pp.  42,  288),  Woltereck  (J. 
Soc.  Chem.  Ind.  1908,  158,  978;  Eng.  Pat. 
2461,  1902 ;  16504,  1904 ;  8358,  1905),  Mond 
(J.  Soc.  Chem.  Ind.  1889,  505),  and  Roth 
(D.  B.  P.  191914),  in  which  a  mixture  of  nitrogen 
and  hydrogen  is  passed  over  various  heated 
catalytic  agents,  do  not  appear  to  have  resulted 
in  any  commercial  yield  of  ammonia.  Haber 
(Zeitsch.  Elek.  Chem.  16,  244)  has  found  that 
when  a  mixture  of  1  vol.  of  nitrogen  and  3  vols. 
of  hydrogen  is  heated  with  metallic  osmium 
to  550°  under  a  pressure  of  200  atm.,  a  very 
considerable  production  of  ammonia  takes  place 
amounting  to  8  p.c.  of  the  mixed  gas,  and 
although  osmium  is  too  scarce  and  expensive 
for  tecnnioal  use,  it  may  be  replaced  by  metallio 

*  For  more  complete  details,  tee  Lunge's  Goal-Tar 
and  Anamonla  (Gurney  and  Jackson.  1016). 


uranium  with  good  results.  With  a  small 
apparatus  constructed  to  allow  of  the  circula- 
tion of  the  mixed  gas  under  this  pressure  over 
uranium  heated  to  about  500*^,  and  cooline 
between  each  passage  of  the  gas  over  the  metal, 
Haber  has  synthesised  ammonia  at  the  rate  of 
about  90  grains  per  hour,  the  ammonia  separating 
out  on  cooling  under  these  conditions  as  a 
liquid. 

The  Haber  process  has  now  been  developed 
on  a  very  large  scale  by  the  Badische  Anilin 
und  Soda  Fabrik,  and  it  is  stated  that  in  1918 
a  quantity  of  ammonia  equivalent  to  400,000 
tons  of  ammonium  sulphate  was  manufactured 
by  this  method  (Eng.  Pats.  17642,  17951,  1909  ; 
10441,  13097, 15975,  19249, 19778,  20127,  1910  ; 
61,  5833-6,  21151,  24657,  25252,  28167,  1911  ; 
1161,  3345,  9841,  22352,  25259,  1912;  24823, 
1913;  8763,  1915).  The  work  done  by  them 
has  especially  consisted  in  the  design  and  con- 
struction of  suitable  plant  to  withstand  the 
combined  high  temperatures  and  high  pressures 
necessary  for  successful  working,  and  the 
selection  of  suital>le  catalysts  of  less  expensive 
character  than  the  osmium  and  uranium 
employed  in  the  small  scale  experiments.  No 
details  of  the  exact  construction  of  plant  or  of 
the  actual  catalyst  now  employed  nave  been 
published,  but  Benthsen  (Zeitsch.  angew.  Chem. 
1913,  10)  states  that  the  more  expensive  forms 
of  the  latter  first  used  can  be  replaced  by 
cheaper  metals  such  as  iron,  manganese,  and 
molybdenum,  which  are  *  activate*  by  the 
addition  of  other  substances.  Contact '  poisons  * 
both  in  the  catalyst  itself  and  in  the  mixture  of 
nitrocen  and  hydrogen  used  must  be  very  com- 
plete^ excluded ;  the  following  substances 
especially  having  proved  very  deleterious : 
sulphur,  selenium,  tellurium,  phosphorus,  arsenic, 
boron,  some  hydrocarbons,  and  the  readilv 
fusible  metals  or  their  oxides,  such  as  lead, 
bismuth,  and  tin.  Much  experimental  work  on 
the  direct  synthesis  of  ammonia  from  nitrogen  and 
hydrogen  has  been  carried  out  in  Great  Britain 
during  the  last  few  years,  both  on  the  laboratory 
and  on  a  semi -indud trial  scale,  the  results  of 
which  have  only  been  partially  published  {see 
Maxted,  Chemical  Age,  1919,  1,  514,  540,  590). 
Up  to  the  present  (1919)  no  plant  has  been 
erected  for  the  production  of  ammonia  by  this 
method  in  this  country. 

Attempts  to  effect  the  synthesis  of  ammonia 
from  a  mixture  of  nitrogen  and  hydrogen  by 
the  passage  of  the  silent  discharge  or  sparks 
have  fail^  to  give  a  sufficient  yield  for  com- 
mercial success,  and  a  similar  lack  of  success 
long  attended  the  efforts  to  produce  ammonia 
by  combining  atmospheric  mtrogen  with  ele- 
ments which  readily  form  nitrides,  such  as 
boron,  titanium,  magnesium,  and  subsequent 
conversion  of  the  nitride  into  ammonia  by  the 
action  of  steam.  Recently,  however,  Serpek 
and  the  Soc.  Gen.  des  JNitrures  (Eng.  Pats. 
13679,  1906;  7607,  15996-7,  1909;  13086, 
1910;  23544,  25141,  1911;  8347-9,  10036, 
22435,  25630,  1912;  10975,  11091,  21366, 
23740,  24731,  27030,  27971,  1913  ;  4287,  22586, 
24533, 1914)  have  developed  a  process  dependent 
on  the  formation  of  aluminium  nitride  by  the 
action  of  carbon  and  nitrogen  on  alumina  at 
high  temperatures,  and  subsequent  conversion 
of  the  nitride  into  ammonia,  with  recovery  of 


202 


AMMONIA. 


the  alumina,  by  heating  with  water  under 
preesure.  To  carry  out  the  prooeas,  bauxite, 
which  reacts  more  readily  than  pure  aJumina,  is 
preheated  to  a  temperature  of  about  1600^  and 
passing  through  a  reyolving  electiio  carbon- 
resisting  fumMe,  the  nitrogen  being  supplied 
from  a  current  of  producer-ffas  passing  through 
the  furnace  in  the  opposite  oireption  to  the  flow 
of  bauxite.  The  crude  nitride  is  then  heated 
under  pressure  with  dilute  alkali*  which  effects 
the  conversion  into  ammonia  much  more  readily 
than  water.  A  number  of  plants  working  this 
process  are  being  erected  in  France  by  the 
Boc.  Gen.  des  Nitrures. 

G.  Produdion  from  cyanides, — ^It  has  Ions 
been  known  that  nitrogen  combines  at  high 
temperatures   with    carbon    and    alkalis   with 

Eroauction  of  Cjranides,  and  many  attempts 
ave  been  made  during  the  last  fifty  years  to 
manufacture  cyanides  m  this  manner  and  to 
convert  these  subsequently  into  ammonia  by 
the  action  of  superneated  steam.  The  laige 
demand  for  cyanides  themselves,  resultins  from 
their  employment  in  the  extractions  of  gold 
from  the  mine  tailinss,  and  the  fact  that  at 
present  nitrogen,  in  tne  form  of  cyanide,  com- 
mands a  higher  price  than  in  the  form  of 
ammonia,  has  made  such  processes  of  no  value 
for  ammonia  production  under  existing  condi- 
tions, and  in  fact,  at  the  present  time,  the 
opposite  process  of  converting  ammonia  into 
,  cyanides  is  carried  on  to  a  la^  extent.  The 
methods  prcmoeed,  so  far  as  they  relate  to 
cvanide  production,  will  be  discussed  under 
that  heading,  but  one  method  may  be  here 
mentioned,  namely,  the  manufacture  of  calcium 
oyanamide,  GaiN'CjN,  according  to  Frank 
and  Caro's  process  (J.  Soc.  Ghem.  Ind.  1908, 
1003),  by  tne  action  of  nitrogen  on  heated 
calcium  carbide,  this  beins  simultaneously  a 
cyanogen  and  an  ammonia  derivative  (v,  Oyan- 
amide^  art.  Nitboobn,  Atmobfhbbic,  Utiijsa- 
TioN  OF).  This  substance  may  readily  be  con- 
verted into  ammonia  by  tho  action  of  super- 
heated steam,  but  it  is  for  the  most  part 
directly  employed  on  the  land  as  a  nitrogenous 
manure. 

■ 

D.  Ammonia  from  urine,  sencage,  and  animal 
excreta, — ^Urine  is  not  merely  the  oldest,  but 
for  centuries  was  the  only  source  of  obtaining 
ammonia  compounds  on  a  commeroisl  scale. 
It  is  stated  that  sal-ammoniac  made  from  it  was 
an  article  of  commerce  as  early  as  1410,  and 
that  the  Jesuit  Sicard  in  1720  saw  the  manu- 
facture of  it  in  the  Delta  of  the  Nile.  In  Effypt 
sal-ammoniac  was  made  by  burning  camels*  dung 
and  collecting  the  sublimate.  Putrefied  mine 
(in  which  the  urea  has  passed  into  ammonium 
carbonate)  has  been  usea  for  centuries,  and  to  a 
certain  extent  is  still  used  by  dvers  as  a  source 
of  ammonia  for  scouring  wool  and  other  purposes. 

Normal  urine  contains  per  litre  from  20  to 
35  grams  urea  (carbamide),  which  after  a  short 
time  is  changed  into  ammonium  carbonate 
under  the  influence  of  a  micro-organism.  An 
adult  man  produces  from  22  to  37  grams  urea 
per  24  hours,  t<^ther  with  a  little  uric  acid, 
corresponding  to  12*5-21  grains  NH,  per  day, 
or  between  9  and  17  lbs.  per  i^Timim  jf  ^11  the 
ammonia  obtainable  from  London  urine  were 
recovered  this  would  amount  to  100,000  tons 
of  ammonium  sulphate  per  annum. 


Owing  to  the  now  almost  universal  adoption 
of  the  removal  of  sewsge  by  means  of  water,  the 
dilution  of  the  ammonia  in  the  combined  sewage 
is  so  great  that  its  recovezy  is  hardly  praoticabfe, 
but  with  concentrated  pan  sewage,  recovery  of 
ammonia  is  carried  on  in  a  few  places,  especially 
in  Paris.  A  large  number  of  patents  have  been 
taken  out  for  we  recovery  of  ammonia  both 
from  sewaffe  and  also  from  the  more  concen- 
trated sluc^e  deposited  in  the  ooUeoting  tayoks 
at  the  sewsge  works,  amons  which  may  be 
mentioned  Duncan  (D.  R.  PP.  27148,  28436), 
Young  (Eng.  Pat.  3652,  1882),  Bolton  and 
WanUyn  (Eng.  Pat.  5173,  1880),  Gesellschaft 
fur  WasserabU&rung,  Berlin  (D.  R.  P.  161166), 
Butterfield  and  Watson  (Eng.  Pat.  19602,  1905), 
Taylor  and  Walker  (U.S.  Pat.  603668). 

Ketjen  (Zeitsoh.  anffew.  Ghem.  1891,  294) 
also  reports  a  sucoessfm  recovery  of  ammonia 
from  concentrated  sewage  by  distillation  with 
lime  at  Amsterdam. 

E.  Ammonia  from  guano,  Ac. — ^Whilst  the 
ammonia  obtainable  from  excreta  is  mostly  lost 
for  immediate  recoveiT,  as  it  quickly  passes 
away  into  the  water,  the  soil,  or  the  air,  there 
are  a  few  exceptions  to  this  nUe  presented  by 
the  deposits  of  oirds*  excrements  on  some  desert 
islands,  and  a  few  similar  cases.  In  this  *  guano,' 
ammonia  salts  exist  already  preformed,  and 
ammonia  can  be  formed  from  otner  nitrogenous 
substances  contained  therein  by  heating  guano 
with  lime  (as  patented  by  Young  in  1841),  but 
this  process  is  not  remunerative,  since  the  direct 
manurial  value  of  guano  is  much  superior  to  that 
of  the  ammonia  suts  obtainable  therefrom. 

F.  Manufacture  of  ammonia  hff  ^  dealructive 
distillation  of  nitrogenous  orgamc  matter. — ^I^ 
total  quantity  of  ammonia  commercially  pro* 
duced  by  more  of  the  methods  described  above  is 
at  present  almost  n^Ugible,  nearly  the  whole  of 
the  world*s  supply  of  ammonia  and  its  salts 
being  obtainea  either  as  a  by-product  in  the 
course  of  other  manufactures  in  which  nitfo- 
genous  organic  matter  is  subjected  to  the  process 
of  destructive  distillation,  or  manufactured  syn- 
thetically from  nitrogen  and  hydrogen.  Much 
the  greatest  proportion  is  obtained  in  the  manu- 
facture of  ilfnminating  gas,  power  ffas,  or  coke 
from  coal,  and  in  the  distillation  of  wale  for  the 
production  of  shale  oil.  A  considerable  amount 
IS  also  recovered  from  the  gases  evolved  from 
blast-furnaces  where  coal  is  used  as  fuel,  and 
smaller  quantities  from  the  distillations  of  bones, 
horn,  and  other  animal  refuse,  and  also  from 
the  residue  obtained  from  beet-root  molasses. 

The  total  production  of  ammonia  in  the 
United  Kingdom,  calculated  as  sulphate,  for 
the  year  1913,  previous  to  the  outbreak  of  war, 
and  for  1917  aud  1918,  is  shown  in  the  following 
table,  the  figures  for  1889  being  also  given  to 
indicate  the  increase  in  production  during  the 
past  30  years.  The  statistics  are  taken  from  the 
Annual  Reports  of  the  Ghief  Alkali  Inspector : — 

*      1089        lOlS         1917         1918 
Gss  works         .  87,000  182,180  188,478  173,541 
Ironworks        .    5,600    19,956    13,621    12,717 
Shale  works      .22,000    63,061    60,560    58,311 
Coke  ovens  —     133,816  166,354  164.448 

Producer  eas  and 
other  carbon- 
ising works      .  3000    33,605    29,604    23,534 

117»600  432,618  458,617  432,561 


AMMONIA. 


203 


The  world's 
1913  (in  meirio 
as  follows : — 

Qreat  Britain 
Gennany     . 
United  States 
France 
Belgiamand 
Holland   . 
Other  oonntries 


production  for  1907,  1910,  and 
tons  of  2204  lbs.)  is  estimated 

1907  1910  1913 

.     331,220  369,000  438,932 

.     287,000  383,000  649,000 

81,400  116,000  176,900 

.      52,700  67,000  76,400 

.       66,000      41,000      48,600 
88,000     146,800     123,200 


895,320  1,111,800  1,412,032 
Coal  always  contains  nitrocen  in  greater 
proportion  than  is  present  in  nesh  v^etable 
matter,  this  bein^  probably  due  to  the  remains 
of  ^tniwiiLla  inhabiting  the  coal-forming  forests 
and  swamps.  The  total  percentage  of  nitrogen 
found  in  the  coal  usually  varies  between  the 
limits  of  0*9  and  2*0  p.c. ;  thus  Tidy  (Lunge's 
Coal  Tar  and  Ammonia)  found  in  Welsh  coal 
0'91  p.c.,  in  Lancashire  coal  1*26  p.c.,  and  in 
Newcastle  coal  1'32  p.c.,  whilst  Foster  (Inst, 
av.  Eng.  77,  iii.  23)  found  in  Welsh  anthracite 
0*91  p.o.,  in  English  coals  1*66-1*76  p.c.,  and 
in  Scotch  cannel  1*28  p.c.  Schilling  (J.  Gasbel, 
1887,  661),  using  the  Kjeldahl  method  of 
estimation,  obtained  from  Westphalian  coal 
1*60  p.c.,  from  Saar  coal  1*06  p.c.,  from  Silesian 
coal  1*35  p.c.,  from  Bohemian  coal  1*36  p.c., 
from  Saxon  coal  1  '20  p.c.,  from  Boldon  (Durham) 
coal  1*45  p.c.,  from  Pilsener  cannel  1*49  p.c., 
and  from  Bohemian  lignite  0*62  p.a  McLeod 
(J.  Soc.  Ohem.  Ind.  1907,  137)  analysed  80 
«frmpl^  of  Scotch  coals  and  oannels,  and  found 
percentaces  of  nitrogen  varying  from  0'91  to 
1*87,  ana  averaging  1*43. 

The  world's  production  of  coal  in  1909 
amounted  to  about  960,000,000  tons,  containing 
on  the  average  probably  some  1  *3  p.c  of  nitrogen, 
which*  if  the  mole  were  recovered  as  ammonia, 
would  represent  an  output  of  about  48,000,000 
tons  of  ammonium  sulphate  per  annum.  In 
fact,  however,  the  production,  as  shown  bv  the 
above  figures,  only  amounts  to  about  ^  of  this 
quantity.  Fully  90  p.c.  of  the  coal  is  con* 
sumed  in  such  a  manner  that  the  recovery  of 
the  nitroeen  is  impracticable,  and  where  the 
prooosoea  in  use  are  mostly  such  that  ammonia  is 
recovered*  only  a  relatively  small  proportion  of 
the  nitrogen  is  actually  obtained  in  the  form  of 
ammonia,  for  reasons  discussed  later  in  con- 
sidering the  different  manufactures  in  which  it 
is  produced. 

(a)  Production  o  eunmonia  in  the  manufadure 
of  coal  gas,  and  of  coke  in  by-product  coke  ovens.-^ 
In  this  country  the  carbonisation  of  coal  in 
retorts  for  the  manufacture  of  illuminating  gas 
for  general  distribution  at  present  yields  the 
largest  contribution  of  ammonia,  but  the  output 
from  this  source  is  being  rapidly  approachea  by 
that  obtained  in  the  uialoj^ous  process  of  car- 
bonising the  coal  in  ovens  ror  the  manufacture 
of  haxa  metallurgical  coke.  Formerly  the  great 
balk  of  such  coke  was  manufactured  in  beehive 
ovens,  in  which  case  no  by-products  were  re- 
covered, but  these  are  now  heing  rapidly  re- 
placed by  by-product  recovery  *  ovens.  In 
Germany  and  in  the  United  States  by  far  the 
largest  proportion  is  obtained  from  oolce  ovens. 

In  both  industries,  however,  only  a  portion 
of  the  nitrogen  of  the  coal  is  reoovered  in 


the  form  of  ammonia,  the  remainder  being 
distributed  in  the  coke,  as  nitrogenous  com- 
pounds in  the  tar,  as  cyanide  in  the  gas  and 
ammoniacal  liquor,  and  as  free  nitrogen  in  the 
gas.  The  relative  proportion  of  the  nitrosen 
obtained  in  the  different  forms  varies  consider- 
ablv,  being  dependent  both  on  the  nature  of  the 
coal  and  on  the  conditions  of  carbonisation; 
the  rate  at  which  the  latter  proceeds,  and  es- 
pecially the  temperature  employed  have  a 
markea  influence.  At  low  temperatures,  such, 
for  example,  as  are  employed  in  uie  manufacture 
of  *  coalite '  (about  46(r),  a  very  lane  proportion 
of  the  nitrogen  remains  in  the  coke,  but  with 
higher  temperatures,  although  more  nitrogen 
is  given  off  from  the  coke  primarily  in  the  form 
of  ammonia,  this  is  partly  converted  into  hydro- 
cyanic add  by  the  action  of  incandescent  carbon 
and  partly  dissociated  into  its  elements,  the 
latter  being  especially  the  case  when  the  volatile 
products  as  well  as  the  residual  coke  are  strongly 
heated. 

The  maximum  yield  of  ammonia^  when  coal 
is  carbomsed  in  horizontal  retorts  or  in  ovens, 
appears  to  be  obtained  with  a  carbonising 
temj^erature  of  900''-960**,  and  the  normal  pro- 
duction calculated  as  sulphate  ia  usually  from 
20-26  lbs.  per  ton  of  ooel  carbonised  in  such 
plant.  With  vertical  retorts,  with  even  higher 
oarbonisinff  temperatures,  a  higher  yield  is  ob- 
tained, as  m  spite  of  such  higher  temperatures, 
the  volatile  products  can  escape  from  the  action 
<d  heat  without  being  raised  to  so  high  a 
temperature  as  is  the  case  in  horizontal  retorts 
or  ovens.  Where  the  chaige  in  the  vertical 
retorts  ia  steamed  during  carbonisation  to  in- 
crease the  water-gas  prcwluction  in  the  retort, 
still  higher  production  of  ammonia  is  obtained,* 
and  the  yield  may  then  amount  to  40-60  lbs.  of 
sulphate  per  ton  of  ooaL 

Many  attempts  have  been  made  to  increase 
the  proportion  of  nitro^n  converted  into 
ammonia,  but  none  apphcable  to  these  two 
industries  has  had  any  success.  Cooner's  lime 
process  (Eng.  Pat.  6713,  1882),  in  which  lime 
18  added  to  the  coal  before  carbonisation,  was 
tried  in  many  works,  and  abandoned,  as,  although 
a  ereater  yield  of  ammonia  was  obtained,  the 
gam  in  this  respect  was  more  than  counter- 
balanced by  the  loss  due  to  depreciation  in  the 
quality  of  the  resulting  coke. 

The  foUowinff  table^  which  cive  figures 
obtained  over  a  long  period  of  worKing  in  gas- 
works and  coke  ovens  respectively,  probably 
represent  a  fair  average  of  the  distribution  of  the 
nitrogen  in  the  two  industries  under  modem 
conditions,  although  doubtless  in  different  works 
considerable  variations  from  these  figures  occur. 
The  gas-works  figures  are  given  by  McLeod 
(J.  Soc.  Ch«m.  Ind.  1907,  137)  as  the  result  of 
working  at  the  Proven  Gas  Works,  Glasgow, 
and  the  coke-oven  figures  by  Short  (J.  Soc  Ohem. 
Ind.  1907,  681)  for  the  working  of  Otto-Hilgen- 
stock  Coke  Ovens,  using  Newcastle  coaL 

Oas  works  Coke  ovens 
Nitrogen  in  coke        .  68*3  .  43*31  p.c.  of  total 
in  tar          .     3-9  .     2-98 
as  ammonia    17*1  .  16*16 
as  cyanide  .     1*2  •     1*43 
as  free  nitro- 
gen in  the  gas  19*6  .  37*12 


»> 


>» 


f> 


tf 


ft 


» 


204 


AMMONU. 


MaLeod  does  not  appear^  however,  to  inolude  in 
his  cyanide  figures  the  hydrocyanio  aoid  removed 
from  the  gas  during  condensation,  allowance  for 
which  would  probably  raise  the  cyanide  figure 
to  about  1  -5  p.0. 

In  both  gas  and  coke-oven  works  the  am- 
monia is  recovered  by  cooling  the  gas,  when  tar 
and  aqueous  vapour  oondeuBe,  the  condensed 
water  removing  a  large  portion  of  the  ammonia 
and  other  gaseous  impurities  from  the  oas,  and 
the  remainder  being  recovered  by  washing  the 
cooled  gas  with  water.  Recently^  also,  especially 
in  coke-oven  works,  processes  have  been  adopted 
in  which  the  ammonia  is  directly  recovered  uom 
the  hot  gas  by  washing  with  sulphuric  acid 
after  removal  of  the  tar.  Methods  for  manu- 
facturing ammonium  sulphate  direct  &om  the 
crude  gas,  in  which  the  sulphuretted  hydrogen 
present  is  simultaneously  ozidiBed  to  form  the 
necessary  sulphuric  acid,  have  been  desoribed  by 
Feld  (Ehig.  Fat.  3061,  1909)  and  Burkheiser 
(Ens.  Pat.  20920,  1908;  21763,  1908;  17359, 
1910),  but  the  processes  are  stOl  (1910)  in  tho 
experimental  stage. 

The  various  apparatusemployed  and  methods, 
of  working  are  oeecribed  in  the  articles  on  Gas 
(Coal)  and  Coke. 

(&)  Production  oj  ammonia  in  the  manujat" 
ture  of  producer  gas  from  coal, — In  the  manufac- 
ture of  producer  gas  from  carbonaceous  fuel  (ses 
Gas,  Pboditoxr)  oy  the  introduction  of  limited 
amounts  of  air  and  steam  into  the  incandescent 
fuel,  the  whole  of  the  carbon  of  the  latter  is 
easified  together  with  the  nitrosen  it  contains. 
Where  the  quantity  of  steam  added  is  limited, 
so  as  to  ensure  that  the  gas  produced  shall  only 
contain  small  percentages  of  carbon  dioxide, 
the  temoerature  of  the  producer  is  such  that 
almost  tike  whole  of  the  ammonia  formed  from 
the  nitrog^  is  dissociated  into  its  elements  as 
fast  as  it  IS  produced.  If,  on  the  other  huid,  a 
large  excess  of  steam  is  employed,  the  tempera- 
ture of  the  producer  is  so  much  lowered  that  the 
greater  part  of  the  ammonia  escapes  decomposi- 
tion, and  may  then  be  recoverea  from  the  gas 
evolved.  The  latter  contains  much  lai;^er 
percentages  of  hydrogen  and  carbon  dioxide 
than  that  obtained  by  the  use  of  smaller  quan- 
tities of  steam,  but  is  still  capable  of  economic 
employment,  especially  in  gas  engines.  The 
process  Is  therefore  now  laraely  iMiopted  for 
producers  usiuA  bituminous  rael,  especially  in 
the  Mond  Gas  ^ant,  in  which  up  to  about  76  p.c. 
of  the  nitrc^en  in  the  coal  is  recovoed  as  am- 
monia. This  is  usually  obtained  direct  as 
sulphate  by  washing  the  crude  gas  with  dilute 
sulphuric  acid,  and  subsequent  evaporation  and 
crystallisation  of  the  solution  obtained;  the 
sulphate  thus  produced  has,  however,  generally 
a  yellow  or  brownish  colour,  due  to  the  presence 
of  small  amounts  of  tarry  matter. 

The  use  of  such  large  proportions  of  steam 
is  impracticable  in  gas  works  or  coke  ovens 
where  gas  of  high  calorific  power  or  coke  of  good 
quality  or  both  is  required,  but  with  the  lower 
grade  of  calorific  power  now  manufactured,  a 
moderate  proportion  of  steam  may  be  admitted 
without  undue  reduction  of  the  calorific  power, 
and  results,  as  mentioned  above,  especially  with 
vertical  retorts,  in  the  production  of  greater 
yields  of  ammonia. 

(c)  Production  of  ammonia  from  shale, — In 


the  distillation  of  Scotch  bituminous  shales  for 
the  production  of  shale  oil  (see  Pabaffin), 
ammonia  is  also  evolved,  and  is  recovered  in  a 
similar  manner  to  that  employed  in  gas  works. 
In  this  case  also  the  introduction  of  steam  (and 
also  of  limited  quantities  of  air)  during  the 
distillation  has  the  effect  of  largely  increasing 
the  percentage  of  nitrogen  recovereid  as  ammonia. 
The  objections  to  the  method  which  hold  in  the 
case  of  the  gas  industry  do  not  apply  in  the 
shale-oil  manufacture,  as  the  chief  product,  the 
shale  oil*  is  not  materially  affected  by  the  use  of 
steam,  and  the  coke  formed  is  in  any  case  of 
little  value.  The  gas  produced,  even  when 
steam  is  used,  is  sufficiently  good  for  the  purpose 
for  which  it  is  used,  namely,  for  heatmg  the 
retorts.  The  addition  of  steam  for  increasing 
the  yield  of  ammonia  was,  in  fact,  first  worked 
out  to  practical  success  in  this  industry,  ehiefly 
by  Toung  and  Beilhy  (Eng.  Pat.  1687,  1881 ; 
2164,  1881;  4284,  1881;  1377,  1882;  6084, 
1882  ;  see  also  BeUby,  J.  Soc.  Chem.  Ind.  1884, 
216),  its  application  in  the  case  of  carbonisation 
of  coal  In  producers  for  the  same  purpose  being 
of  rather  later  date. 

(d)  Amirumia  from  lAasi  fumacts, — ^Where 
coal  is  used  as  fuel  in  blast  furnaces  for  oast-iron 
production,  the  waste  gases  contain  considerable 
quantities  of  ammonia  and  tanv  matters,  which 
are  now  largely  recovered  from'  the  jpM^  the  latter, 
after  purification,  bein^  employed  m  gas  ensines. 
In  most  R»gliah  distncts,  the  coal  availaole  is 
not  sufficiently  hard  for  use  in  the  furnaces,  and 
hard  coke  is  used,  the  employment  of  coal  being 
confined  chiefly  to'  the  West  of  Scotland  and  to 
North  Staffordshire,  where  ooal  of  sufficient 
hardness  can  be  obtained.  The  recovery  of  the 
tar  and  ammonia  is  effected  by  cooling  and  wash- 
ing in  a  similar  manner  to  tnat  employed  in  gas 
works,  the  apparatus  being  suitably  modified  to 
allow  for  the  fact  that  the  tar  and  ammonia  are 
much  more  diluted  with  other  gases,  and  that 
large  quantities  of  dust  are  mechanically  carried 
along  with  the  gas  from  the  blast  furnace. 
Processes  for  the  washing  of  the  gas  with  dilute 
sulphuric  acid  do  not  appear  so  far  to  have  been 
permanenUy  successful,  and  the  same  is  true 
ol  the  process  of  Addie  (Eng.  Pat.  4768,  1882 ; 
3246,  1883),  m  which  the  sas  was  mixed  with 
sulphur  dioxide  and  passed  through  a  scrubber 
fed  with  water,  the  resulting  sonition  of  am* 
monium  sulphite  being  oxidiMd  to  sulphate  by 
ejection  of  air. 

The  yield  of  ammonium  sulphate  obtained 
from  blast  furnaces  is  very  similar  to  that 
obtained  in  gas  works  and  from  coke  ovens, 
namely  from  20  to  26  lbs.  per  ton  of  coal. 

(e)  Ananonia  from  peat* — ^Yast  deposits  of 
peat  exist  in  many  places,  especially  in  Ireland 
and  Prussia,  and  as  this  contains  a  good  deal  of 
nitiogen,  amounting  in  some  cases  to  4  p.0.  of 
the  dry  peat,  many  attempts  have  been  nuule  to 
recover  this  nitrogen  as  ammonia.  The  great 
difficulty  in  the  way  has  been  the  very  liu^ 
quantity  of  water  contained  in  the  peat,  which 
is  costly  to  remove,  and  hitherto  very  little 
ammonia  has  been  put  on  to  the  market  from 
this  source.  Of  the  earlier  attempts  that  of 
Grouven  (D.  R.  PP.  2709,  13718,  18051)  is  of 
interest,  inasmuch  as  this  represents  one  of  the 
first  attempts  to  increase  tho  yield  of  ammonia 
by  injection  of  steam  during  distillation,  but 


AMMONIA. 


205 


althoogh  prolonged  exp«*rimenti  wpfb  made 
with  the  process,  it  was  ultimately  al>andoiied« 
Lenoauchez  suggested  the  nse  of  peat  in  gas 
prodaeers  with  subsequent  ammonia  recoveiy, 
and  patents  relating  to  the  matter  were  taken 
oat  uy  Ruderer,  Loe,  and  Gumbart  (D.  R.  P. 
63844),  Kunt7<e  (Enp.  Pat.  9052,  1891),  and 
Pirper  (Eng.  Pat.  28190, 1896) ;  Woltereck  (Eng. 
Patw  16504.  1904 ;  28963,  1906 ;  28964,  1906) 

Frank  and  Ouo,  in  conjunction  with  the 
Mond  jGas  Co.  (Zeitsoh.  angew.  Chem.  1906, 
1569),  find  that  peat  oontahiing  50  p.o.  of  water 
may  be  employed  in  place  of  coal  m  the  Mond 
Gas  plants,  with  production  of  gas  suitable  for 
gas  engines,  and  a  yield  of  about  90  lbs.  of  am- 
monium sulphate  per  ton  of  dry  peat* 

(/)  Ammonia  from  hones^  horn,  leather,  hair, 
skins,  and  other  animal  refuse, — In  the  distillation 
of  bones  for  the  manufacture  of  bone  charcoal 
(animal  charcoal,  or  *  char '),  used  especisdly  in 
sugar  refining,  large  Quantities  of  ammoma  are 
formed,  togetiier  with  tar  rich  in  pyridines, 
known  as  'Dippel's  oiL'  The  carbonisation  is 
frequently  carried  out,  especially  in  France  and 
Germany,  by  heatins  the  bones  in  open  pots 
placed  in  a  tumaoe,  m  which  case  the  tar  and 
ammonia  are  so  largely  diluted  with  hot  furnace 
gases  that  their  recovery  is  rendered  very  diffi- 
cult. In  this  country  generally,  and  to  an  in- 
creasing extent  elsewhere,  the  carbonisation  is 
effected  in  closed  retorts,  and  the  tar  and  am- 
monia recovered  in  accordance  with  the  usual 
gas  works  practice,  the  yield  of  ammonia  being 
equivalent  to  about  50-60  lbs.  of  sulphate  per 
ton  of  dry  bones. 

Other  animal  refuse,  such  as   wool,   hair, 
skin,  waste  leather,  ftc,  is  sometimes  carbonised 
way,  the  residue  being  employed  as 


manure,  and  the  ammonia  recovered  from  the 
gases.  Sometimes,  however,  these  materials  are 
simply  heated  in  cylinders  in  a  current  of  steam, 
which  renders  them  friable  and  capable  of  ready 
dismtegratkm,  when  they  are  directly  employed 
as  manure.  A  further  proposal  is  to  utilise  the 
nitrogen  by  heating  the  dried  refuse  with  con- 
centrated sulphuric  acid,  whereby  the  nitrc^n 
is  converted  quantitatively  into  ammonium 
sulphate,  as  in  the  well-known  Kjeldahl  method 
of  estimating  nitrogen. 

to)  Ammonia  as  a  hy-froduct  in  the  heO^od 
sugar  industry. — ^During  the  evaporation  of  beet- 
root  juice,   small   amounts   of   ammonia   are 
evolved,  which  Vibrans  (D.  R.   P.  15513)  has 
proposed  to  collect.    Much  larser  amounts  can, 
however,  be  obtained  by  the  distillation  of  the 
*  vinasse,'  i.e.  the  residue  left  after  fermenting 
the  sugar  remaming  in  the  mohtsses,  and  dis- 
tilling off  the  alcohol  produced.    This  contains 
nitrogenous  bases,  especially  betalne,  and  on 
dry  distillation  yields  ammonia  and  trimeth^l- 
amine.    Vincent  (Chem.  News,  39,  107)  earned 
out  the  distillation  with  the  primary  object  of 
obtaining  trimethvlamine  and  from  the  latter 
methyl  chloride,  but  the  ammonia  was  simul- 
taneously recovered  as  sulphate.    The  residue 
from  the  distillation  is  rich  in  potassium  salts, 
and  is  employed  as  a  manure  or  worked  up  into 
para  salts.    Other  patents  dealing  with  the 
recovery  of  ammonia  by  distillation  of  vinasse 
ace  those  of  Ernst  (D.  R.  P.  13871),  Lederer 
and  Gintl  (D.  R.  P.  17874),  and  Meyer  (Eng.  Pat. 
17347.  1887).    Bneb  (Eng.   Pat.  7175,    1895} 


26259,  1898;  see  also  Ost,  Zeitsch  angew. 
Chem.  19,  609)  utilises  the  vinasse  for  the  pro- 
duction of  both  ammonifc  and  cyanides,  the 
latter  being  the  product  especially  aimed  at. 
In  his  process  the  vinasse  is  carbonised  in  retorts 
in  the  ordinary  manner,  and  the  gases,  which 
contain  ammonia  and  trimethylamine,  but  little 
hydrocvanio  acid,  are  then  passed  through  a 
hiffhly  heated  brickwork  chambor,  the  ammonia 
bemg  only  slightly  affected,  whilst  the  trimethyl* 
amine  is  converted  chiefly  into  hydrocyanic  acid. 
The  resulting  gases,  containing  about  7  p.c.  of 
ammonia  and  7  p.c.  of  hydrocyanic  acid,  are 
passed  through  sulphuric  acid  to  recover  the 
ammonia  as  sulphate,  and  the  gas  freed  from 
ammonia  employed  for  the  manufacture  of 
cyanide. 

IL  Properttfls  and  Composition  Of  Ammonlacal 
Liquor.    The  ammoniaoal  liquor  obtained  by 
the  washing  and  cooling  of  the  gases  produced 
by  destructive  distillation,  is,  alter  separation 
from  tar  by  settling,  a  liquid  having  a  colour 
from  pale  vellow  to  dark  orown,  and  smelling 
stroxudy  of  ammonia,  sulphuretted  hydrogen, 
and  luso  of  phenols.    Its  specific  gravity  usually 
varies   from    1*01    to    1-03.    In   the   coal-gas 
manufacture,  the  liquor  is  usually  obtained  in 
three  stages,  viz.  (1)  the  hydraulic  main  liquor, 
formed  durinff  the  cooliujg  of  the  gas  to  tempera- 
tures of  50*-60*,  which  is  usually  weak  (O-S-IO 
p.c.  of  NH,),  owing  to  the  lessened  solubility  of 
ammonia  at  that  temperature;    (2)  the  con- 
denser   liquor,    produced    in    tiie    subsequent 
cooling  of  the  gas  to  atmospheric  temperature, 
which  is  more  concentrated  (2-3*5  p.c.  of  NH,) ; 
and  (3)  the  scrubber  and  washer  liquor,  formed 
by  washing  the  cooled  gas  to  effect  complete 
removal  of  the  ammonia,  the  strength  of  which 
varies  considerably,  and  depends  largely  on  the 
construction  of   the  washing   planC  &nd    the 
supervision    of    the    working.    The    first   two 
products  together  form  the  ^virgin  liquor,'  i.e. 
solution  produced  from  the  water  formed  by  the 
condensation  of  the  steam  always  present  in  the 
crude  gas ;  but  the  liquor  from  all  sources  is 
usually  collected  tose^er  with  the  tar  in  a 
common  storage  well  or  weUs.    frequently  the 
weak  hydraulic  main  liquor  is  used,  after  cooling, 
in  the  preliminary  washers  or  sorubbers,  thereby 
effecting  a  further  partial  removal  of  the  am- 
monia, and  becoming  simultaneously  concen- 
trated, but  for  the  complete  removal  of  the 
ammonia  the  gas  must  be  washed  with  fresh 
water  in  the   final  scrubber.      In  coke-oven 
works  the  conditions  prevailing  in  these  respects 
are  very  similar  generally  to  those  in  gas  works. 
The  quantitative  comjposition  of  the  ammo- 
niacal  liquor  varies  considerably,  not  only  in 
that  obtained  at  different  stages  of  the  process, 
but  also  in  the  average  liquor  obtaineo,  being; 
dependent  on  the  nature  of  the  coals  carbonised, 
tiie  conditions  of  carbonisation,  and  the  con- 
struction and  working  of  the  condensing  and 
scrubbing  plant.    The  qualitative  composition 
varies  but  little ;  the  primary  products  formed 
in  the  liquor  are  ammonium  chloride,  sulphides, 
carbonates,    and    cyanide,    produced    by    the 
action  of  the  ammonia  sdution  on  the  acid 
constituents  of  the  crude  gas,  viz.  hydrochloric 
acid,  sulphuretted  hydrogen,   carbon   dioxide, 
and  hydrocvanic  acid.    The  strongly  acid  hydro- 
oblorio  aoid  is  absorbed  m  the  earlier  stages  of 


Soe  AlCM 

the  cooling,  chloride  being  only  pneent  to  anj 
extent '  in  the  hjdranlio  mun  uid  oondensei 
liqncr,  but  the  totel  quuitity  of  unmonia 
pieeHit  ii  Insuffiaient  to  remove  the  whole  ot 
the  temftining  aeid  gasee,  which  are  separated 
Uter  by  apeoial  pnnfication  processeo.  Other 
ammoDtum  Mlt«  ue,  hovever,  produoed  in  the 
liquor  b;  leoouduy  leaotioni ;  thiu  the  aulpliida 
is  ozidiMd  by  tlie  oxygen  alvajB  present  in  the 
(jrode  gaa,  and  later  by  the  oxygen  of  the  air  to 
which  it  i*  expoeed  daring  storage,  jieldina 
poljanlphklca,  thiosalplulte,  aulpliate,  and 
poMibly  iolphite.  The  oyuiide  reoeta  with 
the  polynilphide,  forming  tliiooyanate,  and 
poasibly  auo  with  thlaaiilphat«,  forming 
tbiocjmnate    and    snlpbito,    so    that  polyral- 


lerroeyanide  are  alsa  s 
formed  by  the  action  of  ammonium  pTanida 
on  the  ironwork  of  the  appuatna.  In 
addition,  tlie  liquor  always  eon  tains  small 
quantities  of  pyridine,  and  oonsiderable  amounts 
of  Bubetanoee  derived  from  the  tar,  especially 
phenols. 

From  the  point  et  view  of  the  subseqnent 
working  up  of  the  ammoniacal  liquor,  it  is 
important  to  distinguish  between  the  amooBt  of 
'  volatile '  and  '  fixed  *  ammonia  present.  The 
former  repreoents  the  ammonia  present  as  sol- 
phida,  oarbonate,  and  cyanide,  and  in  oombina- 
tion  with  the  phenols,  the  term  bung  eiveo 
because  tiie  ammonia  in  this  form  is  com[Jetdj 


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The  qoantitgr  of  phenol*  pieeeot  in  gas-works  liquor  nsnally  variea  fnm  0-1  to  0*30  gnunt 
pet  100  0.0.  (akirrow,  J.  Soo.  Chem.  Ind.  1908,  68). 

:    Ohlel  Alkali   Inspector,  and   pablished  in   the 

annual  reports  <d  the   latter.     In  addition  an 

>    analTsisisalsogiTenofllieUqnor  obtained  in  low- 


dissociated  and  volatilised  by  simply  boiling  the 
•olntion;  whereas  that  present  as  ohloridk, 
sulphate,  thio«ulpbat«,  and  tbiooyanate  is  not 
evolved  to  any  material  extent  tmdec  these 
conditions,  and  Is  therefore  termed  'fixed' 
ammonia.  For  its  recovery  it  is  neoesaary  to 
add  to  the  liquor  a  •ufftoient  amount  of  a  itionger 
alkaU  to  combine  with  the  whole  of  the  above- 
named  acids  present.  The  '  fixed  *  ammonia  in 
the  avenge  liquor  usually  amounts  to  from 
aO  to  2S  p.c  of  the  whole,  but  the  proportion  is 
much  higher  in  the  hydraulic  main  and  con- 
denser liquor. 

The  above  table  gives  the  result*  of  a 
numtmr  of  analyses  of  ammoniacal  liquor  from 
gaa-works,  coke-ovens,  shale-works,  and  iron- 
works,   made   by    Linder,   on    behalf  of    the 


lempeiatnie  oarbonisation  a*  practised  In  tba 


Sasbei,  1908.  488).  '(For  'methods  of  a^alyna, 
MS  Linder  (Alkali  Inspector's  Report,  1009,  IS), 

and  Hay et  and  Hempel  (I-c)-)  In  theee  analysea 
the  whole  of  the  carbon  dioxide  and  sulphuretted 
tiydrogen  present  ia  calculated  as  the  normal 
carbonate  and  sulphide  icapectively,  and  in 
Linder's  analyses  the  difierenoe  between  the 
total  sulphur  and  that  pnsent  as  sulphide, 
sulphate,  and  tluoayaoats  is  calculated  as 
ammonium  tbioeulphate. 

The    existence    ot    free    amtnonia    (or    it* 


hydioidde)  is  *  point  <m  whiob  Mnaidrnibk 
diSeienoe  of  opinioD  exiata.  The  above  analy- 
tiieti  iMolta  kppeM  to  ahov  that  in  the  ooae  of 
aToage  stMed  liqnw,  the  qnaotity  id  *ad» 
pnaent,  indndiiigidMDo],  h  nanaUr  inffldent  to 
combina  wiUi  tna  whole  of  the  ammonia 
bat  at  the  nine  time  it  ia  Tec;  probable  that 
aome  of  the  salta,  eepeciall;  the  snl^hidea  and 
varbonatee,  nndeigo  bydrol^io  dissociation  into 
acid  and  free  ammonia  or  ita  hydroxide  in  the 
aolatioD.  With  the  hydraulio  main  liquor, 
formed  at  tempoatnrea  moetly  above  60",  the 
adda  found  are  iDnffioient  to  oombine  with  the 
wbrie  of  the  ammonia,  aome  of  which  moat 
khetefofe  be  praoent  in  the  free  atate.  The 
exiatenoe  of  free  ammoainm  cyanide  in  the  liquor 
baa  alao  frequently  been  denied,  bnt  more 
perfect  methoda  of  analyits  have  abown  that 
thia    ia   undoubtedly   often    praent    in    amall 


Quantity  oven  in  atored  gaa-worka  Uqnoi,  and 
that  in  ooka-oven  liquor,  wUah  ia  nanally  on(y 
•tmed  for  a  abort  time  befota  working  Dp,  the 
amount  maj  be  oonaiderable.  Tlie  pnaenoe  of 
^anide  ia  objeotltmaUe,  aa  it  inorraaM  th« 
amount  of  hyifroc^ranio  aoid  in  the  waste  naea 
from  the  maaofaotnre  of  ammonium  mlphate 
[au  below). 

IIL  Valuathm  o(  Ammontanl  Uqmr,  In 
this  ooontry,  for  teohnioal  purpoeee,  the  attenfth 
of  the  ammoniaoal  liquor  a  mostly  expraaaed  in 
terms  of  '  oonoo-atreDftb,'  this  flgoie  repi«> 
Banting  the  number  oTounoea  amrdnpoia  of 
pnre  aulphnrlo  acid  required  to  nentaalMe  the 
ammonia  ooutah>ed  in  I  gallon  of  the  liqvor,  and 
for  sUtiatioal  pnrpoaea  <»  saK  Um  volnnies  of 
liqQor  are  uaually  converted  into  the  eqaivalent 
TolDme  of  liquor  of  lO^oz.  strangtk  la  order  to 
convert  these  flguroa  into  the  more  generally 


famlCar  ones  of  grama  per  100  0.0.,  the  'm.- 
atrengtb '  Sgnies  must  b«  moltipbad  bj  0-il7, 
and  ooDverselv,  to  oonvert  flgniea  representing 
grama  per  100  0.0.  into  OK.-atrangth,  the  former 
muat  be  multiplied  by  4-61. 

Fca  approximate  purposes  the  amntonja 
content  (A  the  liquor  is  frequently  estimated 
{lom  the  density,  it  being  found  that  each  1" 
Twaddell  oomsponds  roughly  to  2-oz.  strength. 
Thia  approximation  ia  simcient  for  aooh  pur- 
posea  aa  the  control  of  the  daily  working  of  the 
waahccs  and  aarubbers  on  the  works,  but  quite 
anaoitable  for  purposes  where  fair  accuracy  is 
iliiiiiiiil.  as  a  liquor  showing  G*Tw.,  for  example, 
may  vary  in  actual  content  from  8-  to  12-01. 
atrength,  aa  ogstoat  the  aupposed  10-oz.  For 
any  bnt  the  roughest  purposes,  ammonia  m 
estimated  by  the  usual  method  of  dtstilliiig  a 
known  volume,  after  addition  of  alkali  to 
decompose  the  fixed  salta,  collecting  the  dis- 
tillate in  excess  of  standard  acid,  and  titrating 
the  nnur^  acid  with  standard  alkali.  Tho 
liquid  muat  not  be  distilled  to  dryness,  as  other- 


wise the  thiooyaoatf  a  may  be  decompoaed  with 

formation  of  amntonia,  giving  too  hiKh  rwulu. 

IV.  Working  np    ot    Ammoniaoal   Uqnor. 

In  the  earlier  daya  of  the  utilisation  of  gas 
liqnor,  this  was  simply  neutralised  with  aulphurio 
or  hydrooblorio  acid,  and  the  resulting  solution 
evaporated,  bnt  the  products  obtained  wei« 
very  impnre,  oontainmg  tarry  matter  and 
thiooyanate,  and  the  escaping  gases,  eepeoiaUy 
the  snlpburetted  hydrogen,  created  great 
nuisanoe.  At  present  the  ammonia  is  almoat 
invariably  recovered  from  the  Lquor  in  the  first 
instance  by  distillation.  Formerly,  also,  in 
muiy  oases,  only  the  volatile  ammonia  was 
recovered,  as  this  could  be  obtained  without 
addition  of  alkali,  the  fixed  ammonia  being  run 
oS  with  tjie  waste  liquor;  but  this  procedure  is 
now  becoming  exceptional,  the  fixed  ammonia, 
except  in  the  case  of  some  small  ^lanta,  being 
also  mostly  recovered  by  addition  of  the 
necessary  alkali.  On  account  of  its  cbeapnesa, 
lime  is  almoat  always  employed  foe  this  purpose, 
bat  ia  some  small  plants,  caoatia  soda  ia  uaed. 


SOS 


AMMONIA. 


for  althout^h  the  cost  of  the  latter  is  rtiuoh 
greater,  thiB  is  held  by  some  makers  to  be 
compensated  for  in  snoh  plants  by  the  fact  that 
the  stills  ran  much  longer  without  cleaning. 

The  plant  employMl  in  the  distillation  has 
been  of  various  types ;  at  first  an  intermittent 
process  of  distilling  the  liquor  in  externally  fired 
boilers  was  adopteid,  the  distillation  being  con- 
tinued until  the  whole  of  th^  volatile  ammonia 
was  expelled  with  the  steam.  Addition  of  lime 
to  drive  off  the  fixed  ammonia  was  rarely 
practised  with  such  plants,  owing  to  the  forma- 
tion of  thick  deposits  of  lime  salts  on  the  heated 
boiler  |dates.  These  plants  have  now  been 
almost  entirely  superseded  by  continuous 
column  stills,  constructed  on  the  general 
principle  of  the  Coffey  still,  the  intermittent 
system  being  now  employed  only  in  very  small 
works  or  in  special  oases,  such  as  the  distillation 
of  liquors  containing  very  large  quantities  of 
fixed  ammonia,  in  which  case  the  addition  of 
the  necessary  amount  of  lime  renders  the  liquid 
so  thick  that  these  must  be  stirred  by  mechanical 
agitators  to  effect  complete  recovery  of  the 
ammonia.  The  annual  report  of  the  Chief 
Alkali  Inspector  for  1909  shows  that  in  the 
Various  districts  into  which  the  United  Kingdom 
is  divided  for  administration  purposes  under  the 
Alkali  Act,  the  proportion  of  liquor  distilled  by 
intermittent  stilla  varies  from  about  7  p.c  to  ntl, 
and  probably  averages  over  the  whole  country 
from  1  to  2  p.c. 

For  the  purpose  of  heating  the  stills,  three 
methods  have  oeen  employ^ :  (1)  external 
firinff;  (2)  by  means  of  internal  coils  through 
which  steam  is  passed ;  and  (3)  by  blowing  live 
steam  through  the  stills.  The  first  plan  elves 
a  high  fuel  consumption,  as  weU  as  trouble  from 
lime  deposits  on  the  heated  portions  of  the  still ; 
and  of  the  other  two  methods  the  use  of  live 
steam  is  the  most  economical  in  fuel  consumption, 
and  is  therefore  now  almost  invariably  adopted. 

The  ammonia  evolved  on  distillation  is 
converted  at  once  either  into  ammonium  sul- 
phate, concentrated  gas  liquor,  pure  aqueous 
ammonia,  or  liquefied  ammonia.  The  remaimng 
salts  of  commercial  importance,  namely,  am- 
monium chloride,  carbonate,  and  nitrate,  are  now 
rarely  manufactured  directly  from  the  ammonia 
as  evolved  from  the  stills,  but  are  obtained 
either  tern  ammonium  sulphate  or  aqueous 
ammonia  previously  prepared  from  the  gas 
liquor.  Much  the  largest  proportion  of  the 
liquor  is  converted  into  sulphate,  the  demand 
for  this  salt  being  greatest,  owing  to  its  employ- 
ment as  a  nitrogenous  manure.  The  method  of 
manufacture  of  this  salt  wiU  therefore  be  de- 
scribed first»  followed  by  that  of  the  other 
commerciaUy  important  ammonia  derivatives. 

Ammonium  sulphate. — ^A  description  of  the 
different  forms  of  intermittent  stul  formerly 
adopted  for  obtaining  the  ammonia  in  the 
liquor,  but  now  seldom  Ased,  may  be  found 
in  Lunfle's  Coal  Tar  and  Ammonia  4th 
ed.  Of  the  continuous  stills,  those  of 
Grfineberg  and  Blum  (D.  R.  P.  33320)  and  of 
Feldmann  (Eng.  Pat.  3643,  1882)  will  be  de- 
scribed, more  recent  forms  differin^j  from  these 
only  in  detail  and  not  in  general  pnnoiples.  In 
the  manufacture  of  smphate,  the  volatile 
ammonia  is  first  driven  off,  lime  being  then 
added  to  the  liquor  to  liberate  the  fixed  ammonia, 


the  combined  eases  evolved  being  passed  through 
sulphuric  acid. 

The  apparatus  of  GrfhieberK  and  Blum  is 
shown  in  Big.  1,  as  arranged  for  the  manufacture 
of  sulphate.  A  \a  the  still,  b  the  gas-liquor 
heater  or  economiser,  o  the  lime  pump,  and  d 
the  saturator  charged  with  acid  for  absorption 
of  the  ammonia.  The  gas  liquor  enters  the 
economiser  B  by  means  of  pipe  a,  and  is  heated 
by  the  hot  waste  gases  from  the  saturator,  and 
passes  thence  by  the  pipe  h  to  the  top  of  the 
column  1  of  the  still.  tMb  column  Is  divided 
into  a  number  of  compartments  by  horizontal 
division  plates,  the  liquor  flowing  downwards 
from  compartment  to  compartment  by  the 
overflow  pipes,  the  admittea  steam  travelling 
upwards  in  the  reverse  direction  through  the 
central  pipes  o,  covered  by  hoods  naving 
serrated  edges,  which  compel  the  steam  to  bubble 
throng  the  liquor  in  each  compartment^  thus 
driving  off  the  *  volatile '  ammonia  and  aliso  the 
volatile  acids  present,  vis.  oarbon  dioxide* 
sulphuretted  hycurogen,  and  hydrocyanic  add. 

The  lime  vessel  f,  into  wmch  nmk  of  lime  is 
pumped  by  means  of  pump  o  and  pipe  c,  serves 
to  expel  tne  fixed  ammonia,  and  the  boiler  o, 
with  its  stepped  oone,  serves  to  boil  the  liquor  in 
thin  sheets,  oy  means  of  the  steam  coil  a,  and 
thus  to  set  fiee  the  last  portions  of  ammonia. 
In  B  the  first  heating  of  the  liquor  takes  plaoe  by 
means  of  the  hot  vapours  from  the  saturator  d* 
which  asoend  thiougn  the  bell  g,  the  pipe  «,  and 
the  inner  pipes  of  b,  while  the  liquor,  arriving 
at  a,  rises  up  in  B.  It  then  enters  tiizough  6  into 
the  dephlegmatinx  column  a,  and  finds  its  way 
downward  from^amber  to  chamber,  till  it  gets 
into  the  lime  vessel  F.  IVom  here  it  overflows 
by  pipe  /  into  tiie  sludge-catcher  g,  overflows 
here  agam  aU  round  at  hh,  and  runs  over  the 
cone  i  downwards  from  step  to  step ;  from  the 
pipe  ib  it  is  discharged  continuously  and  auite 
spent  to  the  overflow  t.  The  steam  travels  in 
the  opposite  way — namely,  alone  the  steps  of 
cone  t,  upiraids  in  pipe  m,  and  tnrough  n  into 
the  lime  vessel  F.  rtom  here  the  mi^d  steam 
and  ammonia  vapours  ascend  into  the  column 
■,  and  traverse  this  from  chamber  to  chamber, 
and  ultimately  leave  it  by  the  pipe^ .  This  pipe 
enters  the  saturator  D,  ohargea  with  sulphurio 
aoid.  The  sulphuretted  hydrogen,  carbon 
dioxide,  ftc,  collecting  in  the  bell  q,  are  led 
through  the  flue  s  into  the  economiser  B,  where 
they  give  up  their  heat  to  the  gas  liquor,  and 
lose  their  steam  in  the  shape  of  condensed  water. 
Ultimately  they  are  conveyed  away  by  a  pipe 
not  shown  in  the  diagram  for  treatment  to 
prevent  nuisance,  the  methods  adopted  for  the 
purpose  being  described  below. 

Li  theapparatusof  Feldmann  (D.R.P.  21708), 
Fig.  2,  the  gas  liquor,  after  having  passed  through 
the  ordinary  rectifying  column  a,  flows  into  a 
vessel  B,  into  which  milk  of  lime  is  pumped  by 
o  in  recrular  ratervak,  whilst  the  whole  is  kept 
agitated  by  steam  injected  into  the  mixturew 
The  liquor,  after  having  deposited  most  of  the 
lime,  flows  into  a  second  column  o,  where  the 
ammonia  set  free  by  the  lime  is  distilled  off: 
the  spent  liquor  runs  away  continuously  through 
f7,  and  the  gases  and  vapours  pass  over  by  pipe 
h  into  the  mrst  column  ba,  which  serves  both  for 
retaining  the  water  and  for  driving  off  the  vola- 
tile ammonium  salts  contained  in    the  crude 


na  liqDOT.    The  econi 
M,  with  the  gaa-bel]  t. 


J,  and  the  wturatot 

reqniie  no  (peeul  axplaos- 


sott  (Eng.  ] 
MS  patented  »  pcoocM 
e  plant  it  k«pt  under 
rabts  eco '  *-' 


Fio.  2. 
In  more  recent  tjpe*  ot  still,  onl^  ■  iiogle 
Mtnmn  ia  naaally  emploved,  the  Lme  being 
introdnced  into  one  of  t&e  oompartmenta  gf 
the  lower  portion  of  the  still,  which  may  be 
mwie  of  lai^OT  sJEs  for  this  purpose,  the  hood 
bung  also  more  de«F^7  sealed  to  eSect  moro 
TigoTOOB  agitation.  The  mixture  of  liquor  and 
lime  tiien  rrnmw  through  the  lower  compartiaentB 
of  Uie  BtiD,  constructed  in  a  similar  manner  to 
^loae  above.  A  still  of  this  tvpe,  manufaotuied 
br  the  Berlin  Anhaltiaobe  Haaohinra  Aotieo- 
(jcsdbohaft  is  ihowD  in  fig.  3. 


a  amal)  manhole  at  (he  ride.  Soott  (1 
3»a7,1900:  11082, 1901)  hasp) 
in  wUoh  the  wtiola  of  the  pla 
Tacanni,  whereby  oooaidccabte  eoonom;  of  fuel 
iaolaimed.  Thepfautaiidmethodof workingue 
described  h^  BallaatTne  (J.  Om  Light.  S3,  W9}. 
AUorjtto^  of  (>«  ammtmia  in  mlpAurte  aetd. 
— The  0MM  from  (he  still,  oonaisttiig  chiefl  j  of 
ammoiUa  ((earn,  earboa  dioxide,  siilphtire(ted 
hydrogen,  and  small  qoaatitiea  <A  hydrooyanio 
add,  are  conveyed  to  the  Mtorator  (d  in  Fig.  1, 
in  Fig.  2)  ohaiged  with  solpharie  acid.     This  ia 


which  disttibntea  them  over  a  large  area  in 

eatoratM  and  keeps  the  liqnid  tborougbly 
agitated.  In  some  oaaee,  dilute  •nlphurio  acid 
Is  used,  this  beiog  lemoved  and  replaocd  by 
fresh  acid  whsa  nearly  neotralised.  The  sola- 
tion,  after  settling,  is  concentrated  and  orystal- 
lised,  the  mother  liquor  being  returoed  to  the 
satorator.  The  dilute  solution  ot  ammonium 
sulphate  obtained  by  direct  washing  of  the 
crude  gas  with  acid,  as  in  the  Mond  Oaa  prooees, 
is  evkporated  and  crystallised  in  a  similat  way. 
In  most  oaaea,  however,  when  distiUing  gas  liquor, 
a  much  stronger  acid  (of  about  140*Tw.)  is  used 
which  soon  becomes  saturated,  after  which  the 
■mmouium  solphate  oryataUisee  out  as  forioed, 
and  is  removed  by  varioos  means,  fresh  acid 
being  run  in  to  tepliMe  that  removed  as  sulphate. 
Two  types  of  saturate  are  emfdoyed,  (a)  partly 
open,  (o)  closed.  A  common  oonstructioa  of 
the  former  type  1*  shown  in  Fig.  4,  the  gases 


Other  modiBoations  relate  chiefly  to 
provements  in  nMohanical  details,  and  in  making 
the  psjts  more  aooeenble  for  cleaning,  eepecially 
in  the  portions  of  the  still  where  lime  is  present. 
Thos  Waton  (Eng.  Pat.  34832,  1901)  repkoee 
the  oentral  pipe  for  the  stMm  and  circular  hood, 
by  a  narrow  opening  extending  over  nearly  the 
full  diauetw  of  the  still,  and  oovera  this  with 
an  inverted  tnmgh  having  serrated  edRea, 
which  nn  readily  be  removed  for  cleMiing  h 
\ou  1.— T. 


Fio.  4. 

entering  by  the  pipe  b  perforated  aa  shown,  and 
bnbbling  through  the .  acid,  the  waste  gasea 
being  led  off  by  t&e  pipe  e ;  the  sulphate  acoumn- 
latee  on  the  floor  of  the  saturstor.  The  front 
of  the  saturator  is  open,  and  separated  from  the 
closed  portion  by  the  sealing  curtain  a,  which 
does  not  reach  to  the  bottom,  and  enablea  the 
attendant  to  remove  the  sulphate  period ioally 
by  fishing  with  a  perforated  ladle,  the  crystals 
being  placed  on  a  Icad-llneil  drainer  fixed  so  that 
the  iDDlher  liquid   flows  back  to  the  saturator. 


When  rafflcieotlTilry.the  prodaot 
atoclc,  or  it  maj  be  ftt  odm  dried  b} 
m&cbtne. 


B  (lie  tulpbate  aMume*  a  bl 
■tanding  in  tfie  air,  owing  tc  t 


fonw  it  together  with  maoh  lit 

drainer,  thenoe  into  a  oeotrifiigai  maoliine,  the 

mother  liquor  in  either  oaw  letnming  to  the 


With  ft  olosed  taturator  other  ' 
Temovins  the  Bolphate  are  adopted,  a 
tative  erf  thU  tjpe  being  the  Colsm  i 


Fm.  8. 

the  bottom  of  which  oonaistaot  an  inserted  oone, 
to  the  apex  of  which  ia  Szed  a  right-ansled  bend, 
cloaed  b;  a  Bimple  TalTe,coDaiMtng  of  a  oopper 
diM  premed  against  the  Bsnge  of  the  outlet  pipe 
by  a  acrew  clamp.  During  working  this  la 
opened  to  a  aufGcient  extent  to  allow  the  anlphate 
to  fall  out  almost  aa  soon  aa  it  ia  formed. 

The  ammonium  aulphate  thus  obtained 
usually  contain)  from  24  to  26  p.o.  of  ammonia, 
equivalent  to  about  S3-99  p.c.  of  pure  ammouinm 
sulphate.  It  usually  contama  from  O'l  toO'fip.o. 
of  tree  sulphuric  acid,  the  remaiader  consisting 
of  moisture  and  small  quantities  of  insoluble 
matter.  The  salt  produced  with  modem  plant 
has  mostly  a  white  or  greyiah-white  colour, 
discolouration  by  tarry  matter  being  now  of  rare 
e  with  contmaone  stills,  if  the  liquor 


formation  of  traoea  of  Pmssian  blue. 
'    ~    '        "irpenter    an 

Report,  1900,  81).  ii 

_.  due  to  looftl  alkalinitj 

portion  of  the  liquid  in  the 


In  place  of  '  fishing,'  the  aulphate  may  be  '  tesearchei    of    Forbea    Carpenter    md    IJndw 

periodi^lly  or  oontinnonsly  removed  from  the    ■'^■■■'   "'""  '"• *""  '*™'*    "^    ""-  "*■ 

■aturator  by  meaiu  of   a  steam -ejeotor,  which    ' 


oocumng  n. r —  — 

ssturator,  in  which  oaae  hydrocyanio  acid  u 
Borbed  at  that  point,  and,  with  the  traces  of  irmi 
always  present,  forms  ammonium  ferrooyanide ; 
the  latter,  on  eipoaure  to  the  air,  azidisea,  form- 
ing Pniffiian  blue.  Priming  of  the  still,  reaolting 
in  the  introduction  of  fenooyanide*  and  thio- 
oyanates  into  the  satorator,  has  a  similar  effect, 
but  the  production  of  the  blue  salt  often  occurs 
in  absence  of  priming.  Itfl  formation  is  best 
avoided  by  maintaining  the  Uquid  hot  and  of 
anfEoient  acldity.and  arranging  that  the  pasMgo 
of  the  gas  shall  effect  a  thorough  mixing  of  the 
liquid  in  the  aatorator,  so  aa  to  prevent  the 
occunence  of  local  alkalinity. 

Waale  yrodacU  in  Ihe  tnannfaetare  of  Am- 
mOTiium  fluJpftofe.— Three  waste  products  are 
formed  in  the  process :  (a)  the  effluent  liquor ;  (6) 
the  aqueous  condensate  from  the  cooling  of  the 
waste  gasea;  (c)  the  waste  Rases,  The  effluent 
liquor  S  run  into  Battling  tanks,  where  it  deposits 
suspended  lime  sails,  and  become*  cooled.  The 
clarified  liquor  is  sometimes  run  into  the  aewers, 
but  as  it  oonluna  large  quantities  o(  lime  salts 
(espooially  thiocyanate  and  phenols),  this  is 
frequently  not  permitted,  and  itt  disposal  is 
often  a  matter  of  great  difficulty.  In  gas  works 
it  is  sometimes  got  rid  of  by  empbying  it  to 
quench  the  hot  ooke  from  lie  retorto,  and  m 
some  cases  it  is  even  evaporated  to  dryness. 
Fowler  (Alkali  Inspector's  Report,  1907,  01) 
allows  the  liquor,  an«r  conaiderable  dilution,  to 

CI  throu^  coke  filters  inoculated  with  sewwe 
teria,  ™ch,  if  gradually  accustomed  to  the 
liquor,  oxidise  the  thiooyanatea  and  phenol^ 
yietding  a  fairly  pure  effluent,  and  this  may  be 
employed  for  (Ulution  of  the  fresh  liquor  going 
on  to  the  ater.  Radoliffe  (Eng.  Pat.  10076, 
1906)  removes  the  IhiocyanatM  by  preoipifat. 
ing  aa  cuprous  thiocyanate  with  oopper  aulphate 
in  presence  of  solphurona  acid,  the  latter  being 
obtained  by  burning  a  portion  of  the  waate 
gases.  Grosamaon  (Eng.  Pat.  20387,  1900; 
7932,  1907  J  J.  Soc  Chem.  Ind.  1906,  411)  h«i 
also  described  a  procesa  for  avoiding  the  prodnc 
tion  of  waate  liquor  and  recovery  of  the  ferro- 
oyanide and  thiocyanates  pre&mt  in  it. 

The  avoidance  of  the  production  of  waste 
liquor  altogether  is  an  especial  object  in  the 
prooeas  of  tne  Otto-Hilgenstock  Coke  Oven  Co. 
(Eog.  Pat.  12809,  1908)  now  being  adopted  in 
-■ome  coke-ovan  works.  In  this  the  gas  from  the 
ovena  is  treated  for  the  removal  o(  tar  at  tem- 
[leraturM  above  that  at  which  water  condense*, 
and  then  passed  directly  through  sulphuric  amd  ; 
the  aquooos  condensate  obtained  in  the  aubae- 
quent  cooling  of  the  gas  is  free  from  anunoma, 
.nd  only  contains  amall  amounts  at  impurity. 


nation.     When  pyrites  suiphi 
acid  is  employed,  the  resulting  aulphate  may  be 
coloured  yellow  or  brown,  by  araenio  sulphide, 
which  depreciates  its  value,  and  makera  th^efore 
prefer  to  use  acid  obtained  from  brimstone  or 

spent  oxide.     In  many  caaee,  however,  pyrite*    

acid  is  used,  and  the  arsenic  sulphide  which    and  it  is  claimed  that  no  difficulty  is  experienced 
-■-IB  aB  ft  BOum  to  the  surface  of  the  liquid  in  the  ■  jn  disposing  of   it.     Wilton  (Eng.  Pat   103E0, 

— » 1  ..  i.  ( i^_v.i„  .k.  i  |(,^j  ^^  patented  a  somewhat  similar  prooeas 

with  the  same  object. 

The  aqueoua  condensate  obtained  by  ooline 
the  waste  gases  ia  a  very  noxious-smelling  liquid, 
and  is  henoe  termed  '  devil-liquor.*  It  contains 
•ulpbofetted  hydrogen,  pyridine*,  and  (imilar 


ir  removed  as  it  forms,  or  preferably  the 
acid  is  previously  treated  with  a  portion  of  the 
waste  gases  from  the  saturator.  the  Bolpbuietted 
hydroMD  in  which  precipitates  the  arsenic  as  , 
sulphide,  the  latter  being  removed  before  the 
acid  enters  the  saturator-  I 


AMMONIA. 


Sll 


•obstanoaiy  and  hydfoeyaoic  aeid,  and  ii  also 
difficult  to  dispose  of.  The  hot  condensate  from 
the  limior-healer  or  ooonomiser  is  less  objection- 
able  uian  that  obtained  in  the  farther  cooling 
of  the  waste  eases,  which  contains  much  more 
solphaietted  hydrogen;  bnt  if  the  latter  is 
returned  to  the  pipe  conveying  the  hot  con- 
densate and  the  waste  gases  from  the  economiscr, 
most  of  the  solphoretted  hydrogen  is  driTcn  off 
again  into  the  waste  gases,  and  the  combined 
liquor,  after  cooling,  may  be  mixed  with  the 
effluent  from  the  stills  without  increasing  the 
difficulty  of  dealing  with  the  latter  (Broadbeny, 
J.  Gas  Light.  69,  346). 

The  waste  sases,  after  coolins,  consist 
chiefly  of  carbon  dioxide,  sulphuretted  nydrogen, 
and  smaller  quantities  of  hydrocyanic  acid,  as 
well  as  strongly  smellingempyreumatic  yapours 
derived  from  the  tar«  with  coke-oven  liquors, 
which  often  contain  considerable  <^uantities^  of 
cyanide,  the  amount  of  hydrocyanic  acid  may 
TO  considerable,  necessitatmg  additional  care  in 
dealmg  with  it  owing  to  the  poisonous  nature  of 
the  gas.  In  many  cases  the  gases  are  burned 
under  the  boiler  or  other  furnaces,  and  discharged 
with  the  products  of  combustion  from  the 
chimney ;  or  the  gases  may  be  burned  sepaiatdy 
and  the  resulting  sulphur  dioxide  absorbed  by 
passing  the  products  through  a  limestone  tower 
aown  which  water  is  passing,  yielding  a  solution 
of  csloium  bisulphite,  or  through  scrap-iron 
towers,  when  a  solution  of  ferrous  sulphate  ia 
formed  (Wilton,  £n^.  Pat.  16468,  1001).  With 
small  and  medium-sized  plants,  the  sulphuretted 
hydrogen  and  hydrocyanic  acid  are  mostly 
removed  by  oxide  of  iron,  in  a  similar  maimer  to 
that  employed  for  purifying  coal  gas.  In  place 
of  purifying  boxes,  conical  heaps  of  oxiae  of 
iron  on  a  concrete  floor  are  now  much  used,  the 
gas  beins  introduced  from  the  bottom  at  the 
centre  of  the  heap  ;  the  spent  oxide  obtained  is 
saleable  for  its  sulphur  content.  The  sulphur- 
etted hydrogen  may  also  be  precipitated  with 
metallic  salts,  and  where  sulptkurio  acid  is  also 
made,  the  gases  are  burned  and  passed  into  the 
chambers,  thus  recovering  the  sulphur  as  sul- 
phuric acid.  A  considerable  proportion  of  the 
waste  gas  is  converted  into  sulphur  by  the 
Glaus  process  (Eng.  Pat.  3606,  1882;  6070, 
1883 ;  6968,  1883),  also  used  on  the  large  scale 
in  the  Chance  sulphur-recovery  process.  By  this 
method,  sufficient  air  is  mixed  with  the  gas  to 
react  with  the  sulphuretted  hydrogen  in  accord- 
ance with  the  equation  211,8+ Os=2H,0+2S, 
and  the  mixture  passed  through  a  kiln  containing 
heated  ferric  oxide,  the  sulphur  formed  being 
deposited  in  cooling  chambers,  and  the  residual 
gases  passed  through  a  small  limestone  tower 
and  oxide-of-iron  purifier  to  remove  any  sulphur 
dioxide  or  sulphuretted  hydrogen  remaining. 
The  sulphur  obtained  is  not  venr  pure,  owing  to 
tar^  matters,  ftc,  present  in  tne  gases  treated. 

Mjumteetare  of  Canstio  Ammonia  (Liquor 
Ammonlae)  and  of  Liquefied  Ammonia.— Tlie 
pure  aqueous  solution  of  ammonia  was  formerly 
manufactured  by  distilling  ammonium  sulphate 
with  lime  in  intermittent  stiUs  provided  with 
mechanical  arrangements  for  stirring  the  some- 
what thick  cream,  but  it  is  now  usuaUy  made  by 
the  direct  distillation  of  gas  liquor,  with  suitable 
purification  of  the  gas  evolved  from  the  stills, 
which  is  then  dissolved  in  water.     In  addition 


to  the  pure  aqueous  solution,  a  crude  sdtatioQ 
oontainmg  sulphide,  and  sometimes  carbonate, 
is  also  larsely  manufactured,  this  .being 
cheaper  and  equally  applicable  to  many 
purposes,  especially  in  the  manufacture  of  soda 
by  the  ammonia-soda  process,  and  for  the 
preparation  of  other  ammonium  salts.  This 
crude  product  is  termed  'concentrated  gas 
liquor,'  two  kinds  being  manufactured,  the  one 
containing  from  16  to  18  p.o.  of  ammonia,  with 
both  sulpoide  and  carbonate  present,  and  the 
other  from  18  to  26  p.c.  of  ammonia,  with  some 
sulphide  but  little  or  no  carbonate. 

In  the  manufacture  of  the  first-named  liquor, 
the  gases  from  the  stills,  worked  as  in  the 
manufacture  of  the  sulphate,  pass  through  a 
reflux  condenser,  to  remove  some  of  the  steam 
present^  and  then  through  a  direct  condenser, 
the  gases  from  which  are  washed  with  water. 
Working  in  this  manner,  it  is  not  practicable  to 
obtain  a  greater  strength  of  ammonia  than  16-18 
p.c.,  as  with  higher  concentrations  stoppages 
occur  in  the  condenser  from  crystallisation  of 
ammonium  carbonate. 

25  p.6.  Concentrated  Ligttor, — ^In  the  manu« 
faoture  of  this  liquor  containing  little  or  no 
carbonic  acid  and  only  small  amounts  of  sul- 
phuretted hydrogen,  the  crude  gas-liquor  is  first 
subjected  to  a  preliminary  heating  to  tempera- 
tures somewhsft  below  100°  (Hill's  process),  at 
which  temperature  a  laige  proportion  of  the 
carbon  dioxide  and  sulphuretted  hydrogen  are 
evolved,  accompanied  by  only  small  quantities 
of  ammonia,  the  latter  being  recovered  by 
washing  the  evolved  gases  with  water  or  weak 
ammoniaoal  liquor,  or  by  other  suitable  means ; 
the  preheated  liquor  is  then  distilled  as  in  the 
case  of  the  sulphate  process  with  the  addition 
of  sufficient  lime  to  decompose  completely  all 
fixed  ammonium  salts  present,  and  the  steam 
and  gases  from  the  still  passed  through  a  leflux 
condenser,  to  remove  tne  bulk  of  the  steam, 
and  thence  to  a  condenser ;  the  condensate  from 
the  reflux  condenser,  which  contains  a  consider- 
able amount  of  ammonia,  is  returned  to  the 
still.  The  concentrated  liquor  from  the  final 
condenser  contains  usually  about  26  p.o.  of 
ammonia,  and  has  a  yellowish  colour.  It  is 
usually  almost  free  from  carbonic  acid,  and 
should  not  contain  more  than  0'6  p.c.  of  sul- 
phuretted hydrogen.  In  addition  small  amounts 
of  cyanide,  ferrocyanide,  and  thiocyanate  are 
mostly  present,  derived  from  the  hydrocyanic 
acid  evolved  from  the  crude  liquor,  and  also 
small  amounts  of  phenols  and  of  pyridine 
'  bases. 

Pure  Caustic  Ammonia, — ^In  the  manufacture 
of  this  product,  the  procedure  in  the  first  part 
of  the  process  is  the  same  as  in  the  case  of^the 
production  of  the  26  p.c.  concentrated  liquor 
To  further  purify  the  gases  evolved  from  the 
still,  and  to  remove  as  complet^^y  as  possible 
all  impurities  from  them  after  passing  the  reflux 
condenser,  the  gases  traverse  a  set  of  two  or  three 
washers  containing  cream  of  lime  to  remove  carbon 
dioxide,  sulphuretted  hydrogen,  hydrocyanic 
acid,  and  phenol  vapours,  the  pully  used  lime 
flowing  back  to  the  stills  to  effect  the  decompo- 
sition of  the  fixed  ammonium  salts,  and 
recovery  of  ammonia  from  the  cream.  To 
ensure  the  removal  of  the  last  traces  of  sulphur- 
etted  hydrogen,   ferrous   sulphate  solution   is 


SIS 


AMMONIA. 


■ometimef  ftdded  to  the  last  lime  waaher,  the 
ferioiu  hydroxide  formed  hj  the  action  oi  the 
lime  retaming  the  gas  aa  ferrous  sulphide,  or, 
according  to  Pfeiffer  (J.  GasheL  1900,  89),  a 
small  final  washer  oontaining  oaustio  soda 
solution  is  added.  Solutions  of  sodium  per- 
manganate or  ammoniu m  persulphate  may  also  be 
used  (Foucar).  The  gases  then  pass  through  a 
series  of  scrubbers  charged  with  wood  charcoal, 
which  remoTe  the  stronglv  smelling  empyreu- 
matic  substances  deriveafrom  the  tar,  and  in 
some  cases  additional  purification  in  this  respect 
is  effected  by  j^assing  the  ens  through  a  fatty  or 
high-boiline  mmeral  oil.  The  resulting  purified 
gas  is  then  led  into  distilled  water,  and  thus  con- 
verted into  solution  of  any  desired  strength  up  to 
about  36  p.0.  The  charcoal  scrubbers  must  be 
renewed  as  soon  as  their  activity  becomes 
lessened,  the  spent  material  being  revivified  by 
heating  in  closed  retorts. 

Technical  caustic  ammonia  is  usually  dear 
and  colourless,  and  contains  only  small  quantities 
of  pyridine  and  empyreumatic  substances.  When 
these  are  present  in  larger  quantity,  owing  to 
defective  action  of  the  charcoal  filters,  the  liquid 
assumes  a  yellowish  colour  on  keeping.  Its 
strength  is  ascertained  from  its  spooifio 
gravity. 

Liquefied  Ammcnda. — ^The  liquefied  gas, 
stored  in  steel  ovlinders,  is  now  largely  xiroduoed 
and  employed  ror  refrigeration  purposes.  It  is 
manufactured  from  tne  gas  obtained  and 
purified  as  described  for  the  manufacture  of  the 
pure  aqueous  solution,  but  instead  of  passing 
it  into  water,  it  is  wdl  dried,  and  then  oom- 
pvoBsed  by  suitable  pumping  machinery.  The 
commercial  liquid  usually  contains  small 
amounts  of  water,  pyridine,  and  lubricating  oil, 
and  traces  of  other  substances,  but  is  now 
sold,  in  many  oases,  as  of  guaranteed  99-9  p.o. 
purity. 

Ammonlimi  Chloride  (Mariato  of  Ammaola 
or  Sal-uninoillac). — ^This  salt  has  been  mann- 
factured  in  a  similar  manner  to  that  employed 
for  the  sulphate,  by  passm|^  the  eases  from 
the  stills  into  hydroohlonc  acid,  but  as 
lead  is  attacked  under  these  conditions,  the 
saturator  must  be  constructed  of  stoneware  or 
similar  material,  which  has  many  disadvantaffe& 
It  is  now  usually  made  by  neutralising  hyoro- 
chloric  acid  with  concentrated  gas  liquor,  and 
evaporating  and  dystallising  the  resulting 
solution,  or  by  evaporating  a  solution  of  ammo- 
nium sulphate  and  sodium  chloride  in  equivalent 
proportions;  the  sodium  sulphate  formed 
separates  out  during  concentration  as  the 
monohydrate,  which  is  removed  by  *  fishing,' 
leaving  finally  a  concentrated  solution  of  ammo- 
nium chloride,  which  is  purified  by  crystallisa- 
tion. 

It  is  also  manufactured  by  neutralising 
«  galvaniwrs*  pickle  *'  (which  consists  chiefly  m. 
ferrous  chloride)  with  ammonia,  and  by  the 
action  of  ammonium  carbonate  (or  of  ammonia 
and  carbon  dioxide)  on  calcium  chloride  solution, 
the  latter  being  obtained  in  larse  quantity  as  a 
by-product  in  the  ammonia-sooa  manufacture, 
and  in  that  of  potassium  chlorate ;  the  solutions, 
of  ammonium  chloride  obtained  in  either  case 
are  evaporated  and  crystallised  after  removal  of 
the  precipitated  substances. 

Ammonium  chloride  may   be  obtained  iu 


cubical  crystals  by  adding  small  amoimts  of 
ammonium  acetate  to  the  crystallising  solution. 
The  modification  of  crystalline  form  is  probably 
due  to  aoetamide  produced  by  the  decomposition 
of  the  ammonium  acetate. 

Ammonium  chloride  is  frequently  purified 
by  sublimation,  the  sublimed  product  being 
known  as  sal<unmoniac.  In  tins  country  the 
operation  is  carried  out  in  huge  ircm  pots 
externally  heated  and  covered  with  a  similar 
concave  iron  plate  on  which  the  sublimate 
(sal-ammoniac)  forms.  This  is  detached  at  the 
end  of  the  operation,  the  surface  adhwing  to  the 
iron,  which  is  always  discoloured,  being  removed 
previous  to  sale.  In  France  the  discolouration 
with  iron  is  avoided  by  using  earthenwaro  pots, 
but  the  product  is  more  expensive,  owing  to 
the  fact  that  the  pots  are  destroyed  at  each 
operation. 

The  commercial  orystaUised  salt  is  white  or 
only  sliffhtly  discoloured,  whilst  the  sublimed 
material  has  a  fibrous  structure,  and  frequently 
contains  small  amounts  of  iron.  It  is  employed 
in  pharmacy,  soldering,  galvanisui^,  dyeing,  and 
cauco-printing,  and  in  small  quantities  for  many 
other  purposes. 

Ammonium  Carbonate  (Sal-Voiatne).— The 
commercial  product  sold  under  this  name 
consists  of  a  mixture  of  ammonium  bicar- 
bonate NH^'HCX)}  with  ammonium  car- 
bamate NHa'GO'ONH«,  and  contains  about  31 
fi.c.  of  ammonia  and  66  p.c.  of  carbon  dioxide, 
t  is  usually  prepared  by  subliming  a  mixture 
of  about  1  part  of  ammonium  sulphate  with  1-5 
to  2  parts  of  chalk  in  retorts,  the  evolved  gases 
being  passed  into  leaden  chamben,  where  the 
carbonate  is  deposited  as  crusts  on  tiie  walls, 
the  exit  gases  being  washed  with  water  or 
sulphuric  acid  to  recover  the  uncondensed 
ammonia.  Lunge  recommends  the  pawiing  of 
an  additional  quantity  of  carbon  dioxide  through 
the  chambers  to  effect  a  more  complete  recovery 
of  the  ammonia.  As  soon  as  tne  crust  has 
attained  a  sufficient  thickness  it  is  detached,  and 
ia  usually  purified  by  resublimation.  In  Kun- 
heim's  process,  the  carbonate  is  prepared  by 
passing  ammonia  obtained  by  the  distillation 
of  gas  liquor  direct  into  chambers,  where  it 
mixes  with  carbon  dioxide  and  deposits  the 
carbonate  as  a  crust.  {See  also  Bueb,  £ng. 
Pat.  9177, 1910.) 

The  commercial  product  forms  crystalline 
crusts,  smelling  strongly  of  ammonia,  which  is 
partial^  evolved  on  exj^osure  to  the  air,  the 
mass  emorescinfl  and  leaving  a  powder  consisting 
of  ammonium  oicarbonate.  It  is  employed  in 
wool-scouring,  dyeing,  and  as  a  constituent  of 
baking  powc&rs. 

Ammonium  Nitrate.— This  salt  is  produced 
to  a  very  lanre  extent  for  use  in  the  explosive 
industry  and  in  the  preparation  of  nitrous 
oxide.  It  may  be  obtained  by  neutralising 
caustic  ammoma  with  nitric  acid,  and  evaporat- 
ing and  crystallising  the  solution  if  necessary, 
or  by  passing  ammonia-gas  from  the  stills,  after 
purification,  into  commeroial  nitric  acid,  the 
neat  evolved  by  the  combination  causing  the 
evaporation  of  the  water  present  and  production 
of  fused  ammonium  nitrate.  OUcium  nitrate 
may  also  be  converted  into  ammonium  nitrate 
by  passing  ammonia  and  carbon  dioxide  through 


AMRAIVGUBL 


SIS 


ili  aqoecNia  nlaUoo,  caJoium  carbonate  beuag 
pncipitaAed.  li  is,  hovever,  now  chiefiy  pro- 
pared  from  ammoninm  sulpkate  and  sodium 
nitrate  by  the  prooeee  of  Frteth  and  Gccksedge 
(Eng.  Pat.  126678).  This  prooe«  depends  on 
the  fact  that  when  a  eolation  satazi&ed  with 
xeneot  to  ammonium  nitrate*  sodium  nitiate 
and  sodium  sulphate  at  any  given  tempeiatuie, 
but  not  in  contact  with  the  mlid  salts,  is  dilute  d 
with  Bofficieat  water  to  enable  the  solium  salts 
to  be  retained  in  solution  at  a  lower  temperature 
to  which  it  is  to  be  cocked  on  dilution,  then,  on 
eoolins  to  that  temperature  ammonium  nitrate 
eratsllises  out  in  practically  pun  condition. 
After  separaticn  of  the  nitrate,  the  dear  solu- 
tion is  oonoentnatcd  to  diiye  off  the  amount  of 
water  added  on  previous  dilution,  and  a  further 
quantity  ol  a  mixture  of  equivalent  amounts  of 
sodium  nitrate  and  ammonium  sulphate  addtd. 
The  whole  is  maintained  at  a  temperature  not 
lower  than  that  at  whioh  the  original  «as 
saturated  previous  to  dilution  with  vtater. 
Sodium  sulphate  then  separates  in  practically 
pure  condition,  and  after  its  removal  the  dilu- 
tion with  water  and  cooling  is  repeated,  and 
the  cycle  of  operations  repeated.  In  thiti  manner 
the  whole  of  the  ammonium  sulphate  and  sodium 
nitrate  are  completely  converted  into  practically 
pure  ammonium  nitrate  and  sodium  ralphate. 

Calcium  nitrate  may  also  be  converted  into 
the  ammomnm  salt  by  panning  ammonia  and 
carbon  dioxide  gases  through  its  aqueous  solu- 
tions, calcium  carbonate  being  precipitated. 

AmmoniUB  pho^luUe*  Monammonium  phos- 
phate (NH4)H|P04,  and  diammonium  phos- 
phate (NH4),Hf04  have  become  commercial 
products  by  the  process  of  Lsgranoe,  u-hich 
starts  from  commercial  calcium  supe^iosphate. 
This  is  lixiviated  by  water  and  steam,  and  a 
solution  of  42*rw.  is  obtained,  together  with  a 
residue  of  eakiam  sulphate.  Some  of  the 
latter  remains  in  the  solution,  and  is  re- 
moved by  carefully  adding  barium  carbonate. 
The  filtrate  is  neutralised  by  ammonia  in  slight 
excess,  whereby  all  the  lime  is  precipitated  as 
basic  phosphate,  whioh  is  washed  and  used  over 
again  for  the  manufacture  of  superphosphate. 
The  filtered  solution,  marking  32*Tw.,  contains 
monammonium  phosphate,  and  can  be  worked 
for  this  or  for  diammonium  phosphate.  The 
latter  is  obtained  by  gradually  mixing  the  above 
solution  with  Ugnor  ammonitB  of  sp.gr.  0*02,  in 
the  proportion  of  1|  equivalents  of  NH,  to  1  of 
(NH 4)U,(P0«).  The  diammonium  phosphate  at 
onoe  separates  out  as  a  crystalline  mass,  which, 
after  cooling,  is  submitted  to  hydraulic  pressure. 
The  operation  is  carried  out  in  a  dosed  vessel, 
to  prevent  the  escape  of  ammonia.  The  mother 
liquor  is  employed  for  the  manufacture  of 
ammonia.  The  diammonium  j^iosphate  is  prin- 
dpally  used  in  Lagrange's  su|[ar-renning  process. 
Ammoninm  thloeyaiiato  is  manufactured  in 
Qonsidexable  quantity  in  the  crude  state,  but 
the  product  is  for  the  most  part  simply  employed 
as  an  intermediate  product  m  the  manufacture  of 
cyanides.  It  occurs,  as  has  been  mentioned,  in 
considerable  amount  in  gas-liquor,  and  also  in 
spent  oxide,  from  which  it  may  be  extracted  by 
water,  but  in  both  cases  it  is  mixed  with  so 
many  other  impurities  that  its  recovery  is  not 
remunerative;  it  may,  however,  be  easily  iso- 
lated as  ouprous  thiooyanate  by  precipitation 


I  with  copper  sulphate  and  sulphurous  acid.  It  is 
'  prepared  synthetically  from  carbon  disulphide 
j  oy  absorbing  the  latter  in  ammonia  in  presence 
of  bases  such  as  lime  (Albright  and  Hood,  Eng. 
j  PkL  14164, 1894),  the  ammonium  thiocarbonate 
'  first  produced  undergoing  conversion  into  thio- 
'  craiate.    A  concentnted  solution  of  ammonium 

•  tniooyanate  is  now  prepared  in  a  numbtt  of 
I  gas  woricB,  acoordinc  to  tac  British  Cyanide  Co.*s 
'  and  Williams'  process  (Eng.  Pat.  13653,  1901), 

.by  passing  the  crude  gas  containing  ammonia 
and  hydrocyaoio  acid  through  a  purifier  con- 
taining sulphur  in  the  form  of  spent  oxide  and 
moistened  with  water  and  fed  with  powdeied 
sulphur,  the  ammonium  pdysulphide  fir&t 
formed  combining  with  the  hydxocyanio  acid 
to  form  thiooyanate,  solutions  of  8(MK)  p.c. 
strti^th  beiog  readily  obta'ned,  which  only 
contain  small  amounts  of  other  non- volatile 
amAonium  salts. 

The  pure  salt  is  used  in  dyeing  and  oalico- 
printing,  and  may  be  obtained  from  the  crude 
product  by  first  converting  it  into  the  barium 
salt  with  baryta-water ;  or  the  barium  salt  may 
be  produced  by  the  action  of  barium  sulphkle 
on  cuprous  thiooyanate.  After  purifies tion  by 
reorystallisation,  the  barium  salt  is  exactly 
precipitated  with  ammonium  sulphate,  and  the 
solution  evaporated  and  crystallised.  The  white 
deliquescent  salt  has  frequently  a  reddish  colour, 
duo  to  the  formation  of  the  red  f orric  thiooyanate^ 
from  traces  of  iron  present. 

Ammoniam  penulpliato.  This  salt  is  now 
produced  on  the  commeroial  scale  by  the 
dectrolysis  of  ammonium  sulphate,  and  is 
employed  for  photographic  purposes  and  as  an 
oxidising  agent.  The  commeroial  product  usually 
contains  small  quantities  of  lead  derived  from 
the  electrodes  used  in  its  manufacture. 

H.  G.  a 

AMMONIACUM,  AFRICAN,  GUM,  PERSIAN, 

V.  QUM  RKSIKS. 

AMHONUB  V,  ExPLOsiYxs. 

AMMONIUM    MBLEQUETA    v.  Oocculus 

DfDiCUS.  ^ 

AMPANGABEFTE.  A  rare-earth  mineral 
from  Madagascar,  described  by  A.  Lacroix  in 

*  1912.  It  is  a  tantalo-columbate  (containing 
but  little  titanium)  of  uranium  (UOg  19*4  p.c.), 
iron,  yttrium,  thorium,  &o.  The  crystals  are 
orthorhombio  and  form  sub-pwallel  groupings 
of  large  prisms  of  a  brown  odour  and  bright 
greasy  lustre.    Sp.gr.  3 '97-4*29,  depending  on 

I  the  degree  of  hydration,  the  material  being 
,  optically  isotropic.  The  mineral  occurs  asso- 
ciated with  beryl,  oolumbite,  struverite,  and 
!  monasite  in  pegmatite  veins  at  Ampangabe, 
Ambatofotsikely,  and  Ton^afeno.  A  consider- 
able number  of  loose  crystab  have  been  collected 
from  the  weathered  debris  of  the  pegmatite. 

AMPELOPSIDIN,  AMPELOPSOf,  v.  a'ntuo- 

CTAinNS. 

AMPHOTROPHIN.  Trade  name  for  hexa- 
methylenetetramine  camphorate. 

AMRAD-GUM.  This  gum  forms  white, 
ydlow,  and  brown  lumps  of  a  sweetish  taste  and 
resinous  smell.  An  aqueous  solution  (1:2)  is 
viscid  and  strongly  adhesive.  It  also  gives  with 
oil  excellent  emulsions,  whioh  keep  very  well. 
The  dry  substance  contains  0*61  p.c.  of  ash, 
consisting  of  oarbonio  acid,  lime,  iron,  magnesia. 


214 


AMBAD-GUH. 


traces  of  phosphoric  acid  and  silica.  Has  been 
recommended  ^as  a  sabstitute  for  gum  arable. 
It  was  brouffht  into  the  market  some  years  ago, 
and  comes  from  the  Abyssinian  highlands ;  is 
probably  obtained  from  Acacia  etbacta  (Schwein- 
furth).  (H.  Unger  and  Kempf.  Pharm.  Zeit.  33, 
218  ;  J.  Soc.  Ohem.  Ind.  vii.  446.) 

AMYGDALASE,    AMT6DALIN    v.    Gluco. 

8IDXS. 

AMYGDOMITRILB  GLUCOSIDE  v.  Gluoo- 

SIDES. 

AMYGDOPHENIH  v.  Synthetic  dbugs. 

AMYL  signifies  the  hypothetical  mono- 
valent radical  Cfiu^,  derived  from  the  three 
isomeric  pentanes,  GtHi.,  by  removal  of  one 
hydrogen  atom.  Normal  pentane  may  have 
one  hydrogen  atom  snbstitated  by  a  mono- 
valent atom  or  group  in  thiee  ways,  secondary 
pentane  or  dimethylethyUnethane  may  have 
one  hydrogen  atom  snbstitated  in  four  wkya, 
and  tertiary  pentane  or  tetramethylmethuie 
may  have  one  hydroffen  atom  substituted  in 
one  way.  There  are  tnus  eight  series  of  deriva- 
tives of  the  radical  *amyT.'  It  is  usual  to 
designate  as  amyl  compounds  those  of  the  type 
CH,CH,CH,-CH,-CH,X,  where  X  signifies  a 
monovalent  atom  or  group,  and  those  of  the 

type  Qg»^>CHCH,CH,X  as  isoamyl  com- 
pounds.   Frequently   derivatives   of   the   type 

^^' CHi^>^CH,X'  ^^»^  ^  ^^  optically 
active  form,  are  referred  to  as  active  amyl  com- 
pounds, as  the  commonly  occurring  active  amyl 
alcohol  belongs  to  this  dass.  The  other  types 
of  amyl  derivatives  are  designated  accoimng 
to  the  usual  methods  of  nomenclature  in  organic 
chemistry. 

The  amyl  compounds  of  technical  importance 
are  all  prepared  from  fusel  oil,  and  are  therefore 
in  no  case  pure  chemical  individuals,  but  con- 
sist of  an  t^oamyl  compound  containing  a 
variable  proportion  of  tne  corresponding  d- 
amyl  derivative. 

Amyl  Aloohols  GcHnOH.  The  eight  theo- 
retically possible  stiuotural  isomerides  are  all 
known.  Of  these,  three  should  also  be  capable 
of  ftTiMfcing  M  opticallv  active  stereoisomerides. 
This  has  been  reaUsed  in  two  cases,  but  not  in 
the  third,  namely  that  of  methylMopropyl- 
carbinol. 

n-Amj1  Alaohol  GHa'CH,-GHa*GH,'CH,OH 
(Pentanm).  Tlus  alcohol  was  prepared  in  an 
impure  state  by  Schoriemmer  (Amialen,  1872, 
101,  269)  from  crude  pentane.  Wischnegraddcy 
(Annalen,  1878,  190,  328)  concluded  that  it  was 

E resent  in  commercial  amyl  alcohol,  but  this 
as  been  shown  to  be  incorrect  (Tissier,  Bull. 
Soc.  chim.  [3]  9,  100). 

It  is  a  colourless  liquid  of  fusel  oil  odour; 

b.p.    137-7*;     D^=0-8168.    It   U   best  pre- 

pared  by  reducing  valeramide  with  sodium 
and  alcohol  (Chem.  Zentr.  1904  [2]  1698),  or  bv 
a  similar  reduction  of  ethyl-n- valerate  or  etbyl- 
n-propylacetoacetate  (D.  B.  P.  164294,  1905 ; 
see  Biao  Biochem.  Zeitsoh.  1914,  62,  470 ;  and 
Annalen,  159,  70 ;  233,  253). 

iMbatyl  Carbinol  (CH,),CHCH2CH.0H  (3- 

methylbutanol).    Ordinary  woamyl  alcohol,  fer- 

mentatioii  amyl  alcohol,  is  the  omef  oonstitnent 

-^  "uost  Insel  oils.    It  also  ooouxt  as  angeiio  and 


tiglic  esters  in  oil  of  camomile  (Annalen«  105, 
99).  It  constitutes  from  50  to  85  p.c.  of 
technical  amyl  alcohol.  (For  further  details  as 
to  the  isolation  of  Moamyl  alcohol  from  fusel 
oil,  &c.,  see  below  under  *  f^usel  Oil.*) 

It  is  a  colourless  liquid  possessing  a  character- 
istic, oough-provoking,  odour;  b.p.  131*4^/760 
mm.,  46-8714-2  mm.    It  freezes  at  —134°,  and 

melte  at  -117*2'' ;  D^=0-823.    It  is  soluble  in 

50  parts  of  water  at  13-5°.  One  litre  of  water 
dissolves  34 '7  c.c.  isoamyl  alcohol;  1  litre  of 
the  alcohol  dissolves  22*14  c.c.  water. 

It  may  be  prepared  svnthetically  by  reducing 
isovaleric  acia  (from  t«obutylalcohol),  or  better, 
by  the  action  of  trioxymethylene  on  isobutyl- 
magnesium  bromide  (liooquin.  Bull.  Soo.  chim. 
1904,  [3]  31, 599).  It  is  a  strong  poison  both  to 
human  beings  and  to  bacteria.  It  is  about 
eight  times  as  poisonous  to  man  as  ethvl  alcohol. 

Derivatives, — ^Urothane,  ULp.  64 '5  ;  phenyl 
urethane,  m.p.  54°  ;  phenyl  caroamate,  m.p.  55°. 

Secondary  Butyl  CarUnol 

CH,-CH,CH(CH,)*CH,OH 

(2-methylbutanol).  Active  amyl  alcohol,  the 
second  constituent  of  commercial  amyl  alcohol, 
is  a  colourless  liquid  of  similar  odour  to  the 
above.  The  vapour  does  not  provoke  coughing, 
but  has  greater  stupefjring  effects;    b.p.  128°  ; 

D^f =0*816;  [a]^^=-5*90°. 

The  active  alcohol,  in  spite  of  its  Invorota- 
tion  is  more  corxeotly  termed  ^amvl  alcohol,  on 
account  of  its  phonetic  relationships  with  d- 
Molendne  and  with  ({-valeric  add.  The  oxida- 
tion of  the  alcohol  jields  pure  (i-methylethyl- 
acetic  acid.  For  the  methods  of  isolating  the 
pure  active  idcohol  fr»m  fusel  oil,  see  Mow, 
under  *  Fusel  OiL'  It  should  be  noticed  that  all 
technical  amyl  compounds  contain  variable 
amounts  of  the  active  amyl  derivatives. 

Derivatives. — ^Urethane,  m.p.  61°;  phenyl 
carbamate,  m.p.  30°;  3-nitrophthalate,  m.p. 
114°. 

The  active  alcohol  is  partially  or  wholly 
raoemised  by  heating  above  200°,  more  especi- 
ally when  in  the  form  of  sodium  amylate  or  in 
the  presence  of  salts  soluble  in  the  liquid  (Chem. 
Soc.  Trans.  1897,  71,  256;  Proc.  Boy.  Soo. 
17,  308).  The  racemic  alcohol  has  been  synthe- 
sised  by  the  reduction  of  natural  or  sypthetio 
tiglic  aldehyde  (Herzig,  Monateh.  3,  122),  and 
by  the  aotu>n  of  seoondaiy  butylmagnesium 
bromide  on  trioxymethylene  (Freunfuer  and 
Damond,  Bull.  Soc.  chim.  [3]  35,  110).  It  has 
b.p.  128°/749  mm.  Its  add  m-nitrophthalAte 
melts  at  117°.  A  mixture  of  racemic  with 
^amyl  alcohol  was  obtained  by  Le  Bel  (BulL 
Soc.  chim.  1878,  [2]  31, 104). 

Tertiary  BatylearUnol  (CH,),C*CM,OH  (2-2- 
dimethylpropanol).  This  alcohol  is  a  volatile 
solid  meltinff  at  52°-^°,  and  has  a  pleasant 
turpentine-like  odour ;  b.p.  113°~114°.  It  hae 
all  the  characteristic  prc^erties  of  a  primary 
alcohol. 

It  has  been  prepared  by  reduction  of  tri- 
methvlacetyl  chloride,  also,  in  poor  yields,  by 
chlonnation,  Ac,  of  tetramethylmethane  and 
by  the  action  of  a  Griffnard  reagent  on  para- 
formaldehyde or  methyl  formate  (Tissier,  Ann. 
Chim.  Phys.  [61  29,  340 ;  Sameo,  Annalen,  3ffl» 
256 ;  Bouveaalt,  Ckunpt.  tend.  138,  085»  1106). 


AMYJU 


ittf 


Th»  aoiioB  of  nitrons  aeid  upon  this  alcohol 
yields  not  this  alcohol,  but  the  isomeric  dimethyl- 
ethylcarbinol  (Tissier,  Compt.rend.  112,  1066). 
Mettql-n-propylearbinol    CH»-€H(OH)C,li, 
(peatanol-2).    This  ia  a  coloorleas  Hquid  of  b.p.. 

119%  and  D^==0'8102.    It  is  prepared  by  the^ 

reduction  of  methyl-n-propyl  ketone  by  means 
df  Bodiom  amalgam,  or  oetter,  by  the  method  of 
S&batier  and  Senderens  (Chem.  Zentr.  1903,  [2] 
708).  The  best  method  of  preparation  is  by 
the  action  of  propylmagnesinmbromide  on 
aoetaldehyde. 

This  alcohol  is  racemic.  Le  Bel,  using 
PenicUUum  glaucum,  obtained  a  ItBvorotatory 
specimen  (Compt.  rend.  89,  312).  Pickard  and 
Kenyon  (Chem.  Soc.  Trans.  1911,  99,  45),  by 
crystallisation  of  the  strychnine  and  brucine 
hydrogen    phthalates,    obtained    the    pure    d- 

tleohoi;     b.p.  118-6M19-6^    dJ5^«0-8169J 

[o]^=  +  l3'70». 

Mfltliyilfoiiropylearblnol 

CH,-CH(OH)CH(CHJ, 

(4-metiiylbQtanol-2),  a  colourlees  liquid  of  b.p. 
1 13*^,  which  has  the  fusel  oil  odour.    It  does  not 

freeze  at  -33''.    It  has  DJ^==:0-819.    Hydrogen 

halides  react  with  it  very  slowly  to  produce  only 
tsrtiaiy  compounds,  such  as  CsHs*(CH,),-G*Gi. 
It  has  been  prepared  by  the  reduction  of  the 
corresponding  ketone,  and,  in  good  yield,  by  the 
peculiar  action  of  zinc  dimethyl  upon  bromo- 
acetyl  bromide  or  chloroacetyl  chloride  (Anna- 
len,  191 ,  127  ;  209, 87).  It  may  also  be  obtained 
by  the  interaction  of  methylmagnesium  bromide 
and  isobntylene  oxide,  chloroacetone,  or  chloro- 
acetyl chloride  (Compt.  rend.  145,  21). 

This  alcohol  is  racemic ;  the  optioiBJIy  active 
components  have  not  been  isolated. 

DMhyteaitilkOl  C,HsCH(0H)C,H5X  (pento- 
nol-3).  This  is  a  colourless  liquid  having  the 
uraal  amyl  alcohol  odour;  b.p.   114^-115^/749 

mm.;  D"7«=o-8271. 

It  is  prepared  by  the  action  of  ethyl  formate 
oo  zinc  ethyl  (Annalen,  175,  351),  or  on  ethyl- 
magnesium  bromide  (Chem.  2^ntr.  1901,  [2] 
623). 

DtrivaUve. — Phenyl  urethane,  m.p.  48^-49°. 

EtbyUlmethylearblnol  C,H5C(CH,),0H  (1- 
l-dimethylpropanol).  This  alcohol,  commonly 
known  as  *  amylene  hydrate,*  is  a  colourless 
hqnid  possessing  an  odour  resembling  that  of 
camphor;      b.p.     101'5''-102*' ;      m.p.     —12°; 

dJ^^^O-8144. 

It  has  been  prepared  synthetioally  by  the 
interaction  of  propionyl  chloride  and  zinc 
dimethyl  (Annalen,  190,  328).  It  is  produced 
commercially  by  treating  amylene  with  aqueous 
sulphuric  acid,  and  subsequently  boiling  the 
scdotion.  Trimethylethylene,  the  chief,  con- 
stituent of  commercial  amylene,  is  thus  auanti- 
tativdy  converted  into  tertiary  amyl  alcohol, 
which  is  employed  niisdicinallv  as  a  hypnotic. 

FqmI  Oil  is  the  source  of  all  commercial 
amyl  compounds.  It  is  a  yellow  or  brownish 
liqnid  possessing  a  nauseating  taste  and  a 
efaacmcteristic  unpleasant,  coufh  •  provoking 
odour.  It  boils  fit)m  80®  upwaros,  but  chiefly 
between  128""  and  132*.    It  has  a  density  of 


about  0*831  It  bums  with  &  Bright  flame,  and 
its  main  constituents  are  usually  woamyl 
alcohol  and  active  (l8evorotatory)Yi-amyl  alcohol 
in  varying  proportions. 

The  larger  quantity  of  commercial  fusel  oil 
is  obtained  as  a  residue  in  the  refining  of  the 
crude  spirit  from  the  fermentation,  of  potatoes, 
or  molasses.  The  separation  is  effected  by 
fractionating  the  fermented  liquor,,  usually  in- 
a  continuously  operating  plant  {hu  under 
Alcohol).  When  the  ethyl  alcohol  content  of 
the  liquid  has  fallsn  to  15  p. c.  the  fusel  oil  may 
be  removed  from  the  surface,  where  it  separates 
as  an  oily  layer.  Crude  spirit  after  fractiona- 
tion may  contain  95  p.c.  of  ethyl  alcohol,  and 
usually  about  0*4  p.c.  of  fusel  oil.  Brandy  con- 
tains at  the  most  only  traces,  but  the  spirits 
having  the  most  pleasing  aroma,  those  from 
com  or  fruit,  t,g.  cherries,  &o.,  may  contain 
up  to  0*6  p.o.  or  more  of  fusel  oil,  partly  in 
the  form  of  esters.  The  presence  of  the  fusel 
oil  may  increase  the  intoxicating  qualities  of 
the  spirit,  but  the  harmful  effects  ox  excessive 
spirit  drinking  seem  to  be  mainly  caused  by 
ethyl  alcohol. 

The  chief  constituent  of  most  fusel  oils  is 
the  mixture  "of  amyl  alcohols  which  constitutes 
65-80  p.c.  of  the  whole,  and  which  is  sold  as 
conunercial  amyl  alcohol  of  b.p.  128°- 132®. 
The  proportions  in  which  the  two  amyl  alcohols 
occur  in  commercial  amyl  alcohol  vary  con- 
siderably, as  Marckwald  pointed  out,  according 
to  the  source  of  the  specimen.  Ordinary  com  or 
potato  amyl  alcohol  contains  from  13*5  to  22  p.c. 
of  the  active  isomeride,  while  the  amyl  alcohol 
from  molasses  fusel  oil  contains  from  48  to  58 
p.c.  of  the  Itevorotatory  alcohol.  Besides  the 
amyl  alcohols,  ordinary  fusel  oils  contain 
usufidly  from  15  to  25  p.c.  of  itfobutvl  alcohol 
(b.p.  108°),  and  from  4  to  7  p.o.  of  n-propyl 
alcohol  (b.p.  97°).  But  the  fusel  oils  from 
wines  may  contain  large  quantities  (as  much  as 
50  p.c.  of  the  whole)  of  n-butyl  alcohol.  That 
produced  by  the  Fembach  Fermentation  Process 
IS  said  to  contain  65  p.c.  of  butyl  alcohol. 

In  addition  to  these  main  constituents,  there 
are  always  present  in  small  quantities  some  or 
all  of  the  foUowine  :  hexyl  and  heptyl  alcohols, 
furfurol,  acetaldehyde,  t>obutyl  and  valeric 
aldehydes,  ammonia  and  amines,  pyridine, 
pyrazine  derivatives,  traces  of  all  the  fatty 
acids  up  to  capric  acid  in  the  form  of  ethyl, 
amyl  or  oenanthyl  esters,  terpene  and  terpene 
hyoratok 

The  formation  of  fusel  oil  in  fermentation 
has  been  explained  by  Ehriich  (Ber.  1906,  39, 
4072  ;  1907,  40,  1027,  2538  ;  1912,  45,  1006 ; 
Biochem.  Zeitsch.  1911,  36,  477;  see  also 
Biochem.  Zeitsch.  1907,  3,  121  ;  1908,  10,  490). 
Ehriich  has  shown  that  the  addition  of  leucine 
and({-i5oleuoine,  in  the  form  of,  e.^.,  hydrolysed 
egg  albumen,  during  the  fermentation  process, 
results  in  a  largely  increased  yield  of  amyl 
alcohols.  This  is  made  the  basis  of  a  technical 
method  (D.  R.  P.  177174).  Leucine,  from  egg 
albumen,  can  also  be  converted  by  dry  distilla- 
tion into  amylamine  (D.  R.  P.  193166),  and 
thence  into  a  mixture  of  amyl  alcohols  similar 
to  that  occurring  in  fusel  oil. 

Detection  am  Estimation. — ^Fusel  oil  is  best 
detected  in  spirits  by  rubbing  a  little  of  the 
liquid  between  the  hands,  when  the  ethyl  alcohol 


216 


AMYL. 


evaporates  and  the  residue  reveals  itself  by  its 
smell.  When  a  lai^e  quantity  is  available  for 
the  estimation,  it  may  be  accompUdied  by 
sabjeoting  the  material  to  fractional  distillation. 
For  ordimiry  purposes  the  usual  method  depends 
on  the  extraction  of  the  fusel  oil  from  a  SO  p.c. 
ethyl  alcohol  solution  by  means  of  chloroform, 
the  increase  in  volume  of  the  latter  being 
observed  {see  Ehrlich,  Ber.  1907,  40,  1031; 
Pringsheim,  Biochem.  Zeitsch.  1907,  3,  233). 
For  another  valuable  method,  aee  Aberhalden's 
Handbuch  der  bioohemisohe  Arbeitsmethode, 
ii.  11 ;  V.  FusxL  oil. 

Usee, — ^Fosel  oil  and  commercial  amyl 
alcohol  are  valuable  solvents  for  resins,  fats,  and 
oils;  amyl  alcohol,  being  much  more  useful 
for  these  purposes  than  ethyl  alcohol,  is  thezwfore 
indispensable  in  industnr.  It  is  much  used  in 
the  nitrocellulose  smokeless  powder  and  lacquer 
industries.  It  has  been  proposed  as  a  raw 
material  for  the  production  of  synthetic  rubber 
(Perkin,  J.  Soc.  Chem.  Ind.  1912,  31,  616). 

Prewratian  of  Isoamyl  and  d-Amyl  Alcohol 
from  Fusel  Oil, — ^This  separation  was  first 
partially  effected  by  Pasteur  (Annalen,  1855,  96, 
256)  by  the  fractional  crystallisation  of  the 
barium  salts  of  the  amyl  sulphuric  acids.  Le 
Bel  went  further,  usiiu;  the  fact  that  conversion 
of  the  alcohols  into  the  chlorides  by  hydrogen 
chloride  left  a  more  active  residue  than  the 
original  mixture  (Bull.  Soc.  chim.  [2]  21,  542 ; 
25,  545).  Marckwald  finally  isolated  the  two 
alcohols  in  a  state  of  chemical  purity  (Ber.  1901, 
34,  479,  485 ;  1902,  35,  1595,  1602 ;  1904,  37, 
1038),  by  fractional  crystallisation  of  the  3- 
nitrophthalic  esters  and  also  by  using  Pasteur*s 
method.  All  the  pairs  of  derivatives  of  the 
two  components  of  natural  amyl  alcohol 
examined  oy  Marckwald  formed  mixed  crystals. 

To  obtam  isoamyl  alcohol,  use  a  potato  amyl 
alcohol  containing  80  p.c.  of  Moamyl  alcohol 
and  convert  it  at  once  mto  the  3-nitrophthalic 
ester,  which  is  quickly  purified  by  reciystailisation. 

To  obtain  d-amyl  alcohol  ({iaevorotatory),  use 
the  molasses  amyl  alcohol  containing  at  least 
50  p.c.  of  the  required  compound.  Saturate 
with  dry  hydrogen  chloride  at  0°,  and  heat  in 
an  autoclave  for  five  hours  at  1 10°.  On  distilla- 
tion of  the  product  a  lie  uid  is  obtained  containing 
80  p.c.  of  the  active  sicohol.  This  is  then  con- 
verted into  the  3-nitrophthalate  and  recrystal- 
lised  from  benzene  until  the  melting-point  of 
the  compound  is  114".  The  two  alcohols  are 
very  easuv  obtained  from  the  add  nitrophthalic 
esters  by  hydrolysis. 

Amyl  Aeetaie  C«H,iOCO*CH,.  A  colour- 
less neutral  mobile  liquid  having  a  pene- 
trating   odour   resembling    that   of   jaigondle 

pean;     b.p.  138-5M39*;     D^^V  -  0-875.    Is 

easily  inflammable,  and  sparingly  soluble  in 
watw,  but  easily  .so  in  oiganic  solvents.  For 
its  preparation,  1  part  of  commeroiidlv  pure 
amyl  alcohol,  1  part  of  elacial  acetic  acid,  and 
i  part  of  concentrated  sulphuric  acid,  are  heated 
at  100**  for  five  hours,  the  mixture  poured  into 
water  and  the  oil  separated.  The  oil  is  shaken 
with  a  strong  aqueous  solution  of  sodium 
carbonate,  dned,  and  distilled.  {See  also 
Ck>mpt.  lend.  1911,  152,  1671 ;  and  Ens.  Pat. 
4669,  where  fusel  oil,  hydrochloric  acta,  and 
calcium  acetate  are  used.) 


The  alcoholic  solution  is  largely  used  under 
the  name  of   *  Jargonelle   Pear  Essence,*   for 
flavouring  confectionery.    Amyl  acetate  is  an 
excellent    solvent    for    gun-cotton,    camphor, 
tannin,  and  resins,  and  is  therefore    greatly 
used  in  the  celluloid  and  varnish  industries 
It  is  also  used  in  the  manufacture  of  smokeleBs 
powder  and  photographic  films.    It  is  reoom 
mended  as  a  standara  oil  in  photometry  (J. 
Soc.  Chem.  Ind.  1885, 262).    See  alsoAoMTioAasD 

Amyl  Eth«r  Cfin-O-CJB.n.    A  colourless 
liquid   possessing   a   pleasant  pear-like  smeU 
b.p.    172-5"-173*^;    Dfr=zO-7807.    It    is    pro 
pared  by  heating  the  alcohol  to  its  boibncr 
point  with    1/10    part    of    concentrated    sul 
phuric  acid  (D.   B.   P.  200150),  or  with  1/10 
part  of  amyl  iodide  in*  an  autoclave  at  250**.    It 
IS  used  as  a  solvent  in  the  Grignard  reaction, 
for  fat  extraction,  for  perfumes,  alkaloids,  in 
the  varnish  industry,  and  therapeutically. 

Amy!  Fonmte  GsHnO-GO-H.    A  fragrant 

liquid  of  b.p.  123*3'' ;   and  d2I«0'8944,  pro- 

pared  from  fusel  oil  and  formic  add  or  from 
fusel  oil,  glycerol,  and  oxalic  add.  It  is  used 
in  the  syntnetic  fruit  essence  industry  and  in 
the  laboratory  in  the  preparation  of  oxymethy- 
Ime  derivatives. 

d'kmyl  Mereaptan  CtHn'SH.  A  liquid  of 
b.p.  119^-121**,  was  prepared  in  a  state  otpurity 
from  fusel  oil  by  Vorocek  and  Vesdy  (Ber.  191«, 
47,  1515)  and  used  to  resolve  racemic  arabinoae 
into  its  optically  active  components. 

Amyl  Hitiite  C«H|,0-NO.  A  yellow  neutzal, 
or  feebly  acid  liquid,  possessing  a  fruity 
smeU;  b.p.  97°-99'*;  1>16'=0-870-0-880.  It 
bums  witn  a  briUiant  flame.  It  should  be 
kept  protected  from  light,  but  in  any  case 
it  IS  best  dther  freshly  propaied  or  repeatedly 
fractionated  before  use.  'Ae  vapour  should 
not  be  inhaled.  It  is  prepared  by  passing 
nitrous  fumes  into  amyl  alcohol  kept  at  70*^-90^ 
(Balaid,  Ann.  Chim.  Phys.  [3]  12, 318  ;  Williams 
and  Smith,  Pharm.  J.  1886,  499).  Bonveault 
and  Wahl  passed  nitrosyl  chloride  into  a  dry 
mixture  d  pyridine  and  amyl  alcohol  (Compt. 
rend.  136,  1563).  For  a  rapid  method  of  ore- 
paration,  involving  sodium  nitrite,  set  Ber. 
1886,  19,  915. 

The  pure  isoamyl  nitrite  has  b.p.  97"  and 
D  16<'»=0-880  (Dunstan  and  Williams,  Pharm.  J. 
1889,  487). 

It  is  used  in  the  preparation  of  diazo  and 
MonitroBo  compounds  or  nitroso  chlorides,  and 
as  the  *  amylium  nltrosum  '  of  medicine  for  the 
treatment  of  epilepsy,  asthma,  angina  pectoris, 
&c.,  since  it  r^uces  blood  pressure  and  retards 
the  pulse.  It  is  also  used  in  the  manufacture 
of  sweets,  perfumes,  fruit  essences,  &a,  in  spite 
of  its  harmful  effects. 

Tertiary  amyl  nitrite  (CH,),(C,H,)-CO-NO 
(Bertoni's  *  Amylonitrous  Ether  ^)  has  been  **aed 
as  a  substitute  for  ordinary  amvl  nitrite,  its 
action  being  stronger  in  degree  ana  more  lasting. 
It  is  a  yeUow  liquid  of  weak  camphoraoeous 
odour  and  peppermint  taste ;  b.p.  93"  (J.  Soc 
Chem.  Ind.  1889,  1003). 

Amyl  Salicylate  CsHnOCO-CcH^OH  (Amyl> 
enol)  is  a  colourless  refractive  liquid  of  b.p. 
250"  (with  decomposition),  and  115"/2  mm.; 
D  16*=  1*065.  It  IS  produced  by  passing  dry 
hydrogen  chloride  into  a  saturated  solution  oi 


AMYLENBL 


217 


Balioylio  acid  in  amy  I  alcohol,  and  after  aome 
hours  pouring  into  water  and  working  up  as 
usual. 

It  is  used  medicinally  as  an  antirheumatic  and 
in  the  perfume  and  fruit  essence  industry    C.  S.  G . 

AMYLACETIC  ACID  (Active)   v.    Hsptoio 

ACIDS.  

MO-AMYLACETIC  ACID  v.  Hsftoio  acids. 

•*  and  /3-AMTLANS  n(C«Hi,0|)  T 

After  first  extracting  oeraaJs  with  strong 
alcohol,  the  aqueous  eztoaot  contains  gummy 
IsBvorotatory  colloidal  carbohydrates,  which 
are  precipitated  bv  strong  aloohoL  The  product 
so  obtained  from  barley  is^a  mixture,  part  being 
soluble  in  cold  water.  The  insoluble  crumbly 
residue,  amounting  to  2  p.c.  of  the  barley,  is 
«-amylan.  It  has  [ajjo— 21*6,  and  does  not 
reduce  Fehling's  solution ;  it  is  gelatinised  in 
hot  water,  and  yields  viscous  solutions  even  at 
1-2  p.c  concentration.  O'Sullivan  (Chem.  Soc. 
Trans.  1882,  41,  24)  found  it  to  be  nresent  in 
barley,  oats,  wheat,  and  rye,  especially  in  the 
two  first  named.  The  soluble  product  /8- 
amy  Ian  has  [a]p~fi5*;  it  amounts  to  0*3  p.c, 
and  is  very  simOar  to  a-amvlan  in  properties. 

O'Sullivan  obtained  nrom  /i-amylan,  by 
fractional  precipitation  with  alcohol  or  on  boiling 
with  milk  of  lime,  a  similar  substance  [a]D 
— 120*7^  This  he  regarded  as  a  decomposition 
product,  but  this  is  probablv  not  the  case. 
O'SulUvan  stated  that  tne  amylans  yield  glucose 
alime  on  hydrolysis.  Lintner  and  DiUT  (Zeit. 
anaew.  Chem.  1891,  638)  obtained  galactose 
ana  xylose  from  barley  gum.  Wroblewski 
(Ber.  1893, 30, 2289)  obtained  arabinoae.  Lindet 
(Beriin  Congress,  1903,  3,  498)  isolated  a  dextro* 
rotatory  gum  from  barley,  in  addition  to  a 
IsBVo-rotatory  gam. 

Contrary  to  O'SuUivan's  statement  that 
diastase  is  without  action  on  amylan,  Horace 
Brown  (Trans.  Guinness  Research  Laboratory, 
1906, 317,  where  there  is  a  full  account  of  amylan) 
finds  that  when  barley  gum  is  steeped  in  malt 
extract  it  swells  up  and  undergoes  gradual 
liquefaction  and  solution,  and  ill  u  few  days 
its  colloidal  nature  is  lost.  This  is  one  of  the 
most  significant  changes  which  mark  the  con- 
version of  barley  into  malt. 

To  prepare  '  amylans '  in  quantity.  Brown 
boib  the  finely  divided  grain  with  water,  treats 
with  malt  extract  at  S9^-56*  for  an  hour  to 
liquefy  tiie  starch,  boils  again,  and  filters.  The 
filtrate  is  concentrated  in  vacuum  to  sp.gr.  1*060, 
and  three  volumes  80  p.c.  alcohol  (by  volume) 
added  graduaUy.  The  crude  amylans  are 
precipitated  in  large  white  flocks  free  from 
dextrin  and  have  no  oupric  reducing  jrawer.  Cor- 
rected for  ash  and  nitrogen  they  amount  on  a 
number  of  dry  barleys  to  about  9*6  p.c,  and 
have  [a]D+62*  to  +73^  l^iis  amount  {wacti- 
cally  cuxx)unts  for  the  whole  of  the  missing 
constituents  of  the  soluble  portion  of  barley 
after  hydrolysis  with  malt  extract. 

On  hydrolysis  about  60  p.c.  of  glucose  is 
formed,  together  with  arabinose,  xylose,  and 
an  unknown  substance  of  low  angle  and  reducing 
power. 

The  above  dextrorotatory  amylan  repre- 
sents everything  insoluble  in  62  p.c.  alcohoL  By 
a  variation  of  the  method  oi  preparation  a 
carbohydrate  [ali)~100'34%  corresponding  to 
WroblewBki*B  araoan,  waa  obtained. 


it  la  obviooB  that  the  *amvtaas'  rei|uirs 
further  investigation.  According  to  0*Sullivan, 
it  is  probably  owing  to  the  presence  of  amylan 
that  unmalted  barley  oaimot  be  satisfactorily 
employed  in  the  preparation  of  beer.  Malted 
grain  does  not  contain  it.  Distillers  using  raw 
crain  (oato  and  barley)  have  at  times  much 
diilioulty  in  separating  the  wort  (solution  of 
sugars,  &c.)  from  Uie  grains  (undissolved 
portion  of  the  grain  employed)  in  consequence 
of  the  presence  of  amyltui  in  quantity,  the 
barleys  and  oats  of  some  seasons  containing 
much  more  of  it  than  at  other  times.    E.  F.  A. 

AMYLARmSL  isoamyltrimethylammonium 
hydroxide. 

AMYLASE  V.  Diastasx  ;  obo  Enzymis. 

AMYLENE  CsHiq.  Eight  isomeric  amylenes 
are  theoretically  possible,  and  all  have  been  jpre- 
pared.  These  hydrocarbons  have  been  chiefly 
studied  by  Flavitzky  (Annalen,  179, 340),  Wyach- 
negradsky  (Annalen,  190, 336),  and  by  Kondakoff 
(J.  Rusa.  Phys.  Chem.  Soc.  24,  381),  and  can  be 
obtained  by  the  action  of  alcoholic  potash  on 
the  various  amyl  iodides;  or  bv  the  action  of 
dehydrating  agents  such  as  sulphuric  acid  or 
zinc  chlodae  on  amyl  alcohol.  They  can  of  ten 
be  converted  into  one  another  by  the  action  of 
hydriodic  acid  and  the  subsequent  removal  of 
the  latter,  thus : 

MetCH-CH:CH,+HI 

KOH 
*>MeaOHCHIM6        ->    Me«C:CHMe 

•f  aloohoi 

The  amylene  ordinarily  met  with  is  tri- 
methylethylene,  and  is  chiefly  obtained  by  the 
dehydratinc  action  of  sine  chloride  on  fermenta- 
tion amylidcohol. 

Prtparalion. — To  prepare  amylene,  fermenta- 
tion amyl  alcohol  ( 1  part)  is  shaken  with  coarsely 
powdered  zinc  chloride  (1^  parts),  allowed  to 
remain  for  twenty-four  hours,  and  ^en  distilled. 
The  product  consists  of  a  complex  mixture'  of 
paraffins  from  CtHi,  to  CioH„  with  olefines 
from  CjHio  to  C,oHw  (Wurts,  J.  1863, 
507).  These  can  be  isolated  by  fractional  dis- 
tillation (Wurtz),  but  according  to  Eltekow  (J. 
Ruas.  Chem..  Soc.  14,  379),  amylene  is  most 
readily  obtained  if  the  product  is  well  cooled, 
and  shaken  with  dilute  sulphuric  acid  (2  vols,  of 
add  to  1  vol.  of  water),  the  acid  layer  separated, 
diluted  with  water,  and  distilled ;  the  distillate 
consists  of  amylene  (trimethylethylene)  and 
tertiary  amyl  alcohol,  and  the  latter,  on  dis- 
tillation with  sulphuric  acid  (1:1),  yields  pure 
trimethylethylene.  Amylene  may  be  satis- 
factorily obtained  from  commereialamyl  aloohoi 
under  the  following  conditions :  Amyl  aloohoi 
(1*6  litres)  and  concentrated  sulphuric  acid 
(1(X)  C.C.)  are  heated  to  vigorous  boiling  under  a 
reflux  condenser  in  which  the  water  is  main- 
tained at  such  a  temperature  (60''-90'')  as  to 
allow  a  considerable  amount  of  vapour  to  distil 
out  of  the  apparatus ;  the  top  of  the  condenser 
is  connected  with  a  second,  efficiently  cooled 
condenser,  attached  so  as  to  permit  downward 
distillation.  The  heating  requires  a  maximum 
time  of  about  eight  hours.  At  first,  water  and 
amyl  alcohol  pass  over,  whilst  subsequently 
amylene  distils.  The  distillate  is  washed  with 
sodium  hydroxide  to  remove  sulphur  dioxide 
and  the  amylene  isolated  bv  fractionation.  It 
appears  to  consist  of  )3-methyl-Aa.butylene  and 


218 


AMYLENE. 


/i-methyl-A^-butyleiie  oontaininff  onlv  a  negli- 
gible amount  of  7-methyl-A«-DUtyle&e.  The 
residae  in  the  original  flask  contains  amyl 
aloohol  and  woamyl  ether,  which  are  recovered 
by  distillation  with  steam  and  subsequent 
fractionation.  About  260  c.c.  of  amylene  400 
c.a  of  iaoamyl  ether,  and  600  c,o.  of  amyl 
alcohol  are  obtained  from  1600  c.c.  of  the  latter 
(Adams,  Kamm,  and  Marvel,  J.  Amer.  Chem. 
Soo.  1918,  40,  1960 ;  Chem.  Soa  Abstr.  1919,  i. 
61).  Larger  amounts  of  amylene  are  more 
conveniently  obtained  by  the  pyrogenic-catalvtic 
method,  nsmg  aluminium  oxide  as  catalyst 
at  600^-640^,  using  a  suitably  electrically 
heated  furnace  (c/.  Ipatie£f,  Abst.  1903,  L 
693).  The  yield  of  amylene  is  70-80  p.c.  of 
the  theoretical,  and  the  product  is  about  98-99 
p.c.  pentene.  The  cataljrst  retains  its  activity 
for  a  long  time.  Pure  trimethylethylene  can 
be  prepared  by  heating  tertiary  amyl  iodide 
Me,CIEt  with  alcoholic  potash  (J.  Buss.  Phys. 
Chem.  Soo.  17,  294).  It  can  also  be  formed  by 
droppizu^  tertiary  amyl  alcohol  on  to  oxalic  add 
(D.  R.  P.  66866). 

Other  methods  for  obtaining  ordinary  amyl- 
ene have  been  described  by  Balard  (Ann. 
Chim.  Phys.  [3]  12,  320) ;  Bauer  (J.  1861,  669), 
and  Linnemann  (Annalen,  143, 360) ;  Kondakoff 
{le.) ;  Ipatieff  (J.  Buss.  Phys.  Chem.  Soc.  30, 
292);  Tomoe  (Ber.  21,  1282);  Blaise  and 
Courlot  (Bull.  Soc.  chim.  36,  682). 

Propetiies. — ^Amylene  is  a  colourless  liquid, 
b.p.  36**-38''  and  sp.gr.  0*6783  at  0"*  (Le  Bel, 
Bull.  Soc.  chim.  26, 647) ;  b.p.  36*8''  at  762*7  mm. 
(Schiff,  Annalen,  223,  66).  It  combines  directly 
with  a  lacge  number  of  substances  :  with  nitric 
peroxide  (Guthrie,  Chem.  Soc.  Trans.  13,  129 ; 
Wallaeh,  Annalen,  241,  291 ;  248,  161 ;  Miller, 
Chem.  Soc  Proc.  3,  108;  Demganoff,  Chem. 
Zentr.  1899,  i.  1064);  sulphur  chloride  and 
chlorine  (Guthrie.  Chem.  Soc.  Trans.  12.  112 ; 
13,*  46,  129;  14,  136;  Kondakoff,  J.  Rusa 
Phys.  Chem.  Soc.  20,  141;  24,  381;  Ber. 
24,  929 ;  HeU  and  WUdermann,  ibid.  216) ;  with 
bromine  (Wurtz,  Ann.  Chim.  Phys.  [3]  66,  468 ; 
Hell  and  Wildermann,  Lc  ;  Kondakoff,  Le,),  and, 
when  cautiously  mixed  with  well-cooled  sulphuric 
acid,  sp.c[r.  1-67  (2  vols.  H,S04  to  1  vol.  water), 
in  a  freezing  mixture,  is  converted  into  dimethyl- 
ethyl  carbinol,  b.p.  101 -O""- 102*7762  2  mm., 
which  has  valuable  nypnotic  properties  (J.  Soc. 
Chem.  Ind.  8,  1002 ;  9,  660,  889),  and  can  be 
obtained,  after  neutralisation  with  sodium 
hydroxide ;  on  distillation  (Flavitzky,  176,  167) 
with  sulphuric  acid,  sp.gr.  1*646  (2pts.  by  weight 
H,S04  to  1  pt.  water),  methyltMpropyl  carbinol 
is  obtained  (Osipoff,  Ber.  8,  642,  1240).  Amy- 
lene forms  compounds  with  metallic  salts 
(Denigte,  Compt.  rend.  126,  1146;  Kondakoff,, 
J.  Rubs.  Phys.  Chem.  Soc.  26,  36).  When! 
heated  to  high  temperatures,  benzene,  naphtha- 
lene, acetylene,  methane,  carbon,  and  hydrc^en 
aro  produced,  the  products  depending  on  the 
temperature  (Haber  and  Oeohelhauser  (Chem. 
Zentr.  1897,  L  226).  The  action  of  nitrosyl 
chloride  on  smylene  has  been  studied  by  Tilden 
and  Sudborough  (Chem.  Soc.  Trans.  1893,  482). 

In  addition  to  ordinary  amylene,  the  followina 
isomerides  have  been  obtained  : — Normal  amyl- 
ent,  b.p.  39^-40''  (Wurtz,  Annalen,  123, 206 ;  127, 
66;  148,  131;  Zeidler,  Annalen,  197,  263; 
Kondakoff,  J.  Rusk.  Phys.  Chem.  Soc  24,  113; 


Flavitzky  and  Wysohnegradsky,  I.e.) ;  ieopropyi- 
ethylene,  b.p.  2M'*-21-3*'  (FUvitzky  and  Wys- 
chnegradBky,  /.c  ;  Kondakoff,  Ix. ;  Ipatieff,  he.); 
synifMtricai  melhyleihylelhykne,  b.p.  36*  at 
740*8  mm.  (Wagner  and  Saytzew,  Annalen,  176, 
373 ;  179,  302 ;  Kondakoff,  le, ;  Lissier,  Bull. 
Soo.  chim.  9,  (3)  100);  and  unsymmetrical 
methjAahylethyUne,  b.p.  3r-32*,  6p.gr.  0*67  at 
0*  (Wyschnegradsky,  Le, ;  Le  Bel,  Bull.  Soc. 
chim.  26, 646  ;  Kondakoff,  2.c.  26, 364) ;  Methyl- 
tetrameihylene,  b.p.  39*-42*  (Coleman  and  Perkm, 
Chem.  Soa  Trans.  1888,  201) ;  pentanulhyUne, 
b.p.  36*  (Gustavson  and  Demganoff,  J.  Russ. 
Phys.  Chem.  Soc.  21,  344 ;  Markownikoff,  Ber. 
30,  976 ;  Young,  Chem.  Soa  Trans.  1898,  906 ; 
WiflUcenus  and  Hanschd,  Annalen,  276,  327) ; 
axid  dimetkyUritneihylene  (Gustavson  and  Popper, 
J.  pr.  Chem.  166,  468). 

The  action  of  hycbrogen  iodide  on  the  amyl- 
enes  has  been  investigated  by  Saytzew  (Annalen, 
179, 126) ;  whilst  Zeidler  (Annalen,  186,  246)  has 
examined  the  products  obtained  when  various 
amylenes  are  oxidised  with  potassium  perman- 
ganate in  acid,  neutral  and  iJkiJine  rolution, 
with  chromic  acid,  and  with  potassium  diohrom- 
ate  and  sulphuric  acid.  The  nalogen  derivatives 
of  the  various  amylenes  have  been  investigated 
(Lipp,  Ber.  22,  2672 ;  Hell  and  Wildermann, 
23, 3210 ;  Ipatieff,  J.  pr.  Cihem.  161, 267  ;  Chem. 
Zentr.  1898,  ii.  472 ;  Brochet,  Ann.  ChinL  Phys. 
1897,  10,  381 ;  Wassileef,  Chem.  Zentr.  1899,  L 
776;  Froebe  and  Hoohstetter,  Monatsh.  23, 
1076;  Kukuritschkin,  J.  Russ.  Phys.  Chem. 
Soc.  36,  873 ;  Schmidt  and  Leipprand,  Ber.  37, 
632 ;  Hamonet,  Compt.  rend.  138,  1609).  Also 
the  action  of  oxalic  acid  on  various  amylenes 
(Miklosbeffsky,  J.  Russ.  ^hva,  Chem.  Soo.  22, 
496),  the  nitrolamines  (Wallaeh  and  WohC 
Annalen,  262,  324),  ana  the  nitrosites  and 
nitrosates  (Ipatieff,  Chem.  Zenti.  1899,  ii.  178; 
Schmidt.  Ber.  36,  2323,  2336,  3737 ;  Uantisob. 
2978,  4120;  Schmidt  and  Austin,  Ber.  36, 
1768); 

The  following  polymerides  of  amylene  have 
also  been  obtaincKl,  and  can  be  prepared  by 
heatinff  ordinary  amyl  alcohol  or  amylene  with 
zinc  chloride: — Diamylene  CioH|o>  b.p.  167^- 
157'67769  mm.  (Balard,  Amiafen,  62,  316; 
Schneider,  Annalen,  167,  207 ;  Bauer,  Jahres- 
bericht.  1861,  660;  Kondakoff,  J.  pr.  Chem. 
162,  442 ;  Gasselin,  Ann.  Chim.  Phys.  1894,  3, 
6) ;  iriamylene  C|»H,o  (Bauer,  Lc. ;  Gasselin, 
Le.) ;  and  telramylene  C,oH^o  (Bauer,  Lc.).  Also 
derivatives  of  diamylene  (Scmndelmeister,  Chem. 
Zentr.  1896,  ii.  364). 

AMYLOCARBOL.  Trade  name  for  a  dis- 
infectant, said  to  consist  of  carbolic  acid  9  parts, 
amyl  alcohol  160  parts,  green  soap  160  parts, 
water  690  parts. 

AMYLOCOGULASE  v.  Enzymes,  art.  Fbs- 

MUTTATIGM. 

AMYLOFORM.  An  antiseptic  prepared  by 
the  action  of  formic  aldehyde  upon  staron 
(Claassen,  Pharm.  Zeit.  41,  626)  (v.  SYNTHano 

D&UOS). 

AMYRDf  V.  OxjBO-BBsnrs. 

ANACAHUITA.  A  wood  of  imknown  botani- 
cal origin  imported  from  Mexico ;  its  prepara- 
tions are  said  to  be  useful  in  pulmonaiy  disorders. 
The  wood  contains  a  volatile  oil,  an  iron-greening 
tannin,  gallic  acid,  a  yellowish  resin,  sugar,  a 
tasteless  volatile  body  oiystallising  in  warty 


AN^STHBTIOS. 


219 


mawet,  and  a  bitter  sobttanoe  oiyrtallimng  in 
white  needles  (J.  1861,  771 ). 

AMACARDIUM  NUT  (Caahew  Nut,  Kajoo) 
ia  the  fruit  of  Anacardium  occidenUde  (Linn.),  a 
tree  indigenoua  to  Brazil,  Central  America,  and 
the  West  Indies.  It  has  been  transplanted  to, 
and  become  naturalised  in,  many  parts  of  India. 
The  fruit  rests  on  a  fleshy  edible  peduncle,  from 
which  a  spirit  is  distilled  in  Mozambiaue  and  in 
Western  India.  The  nut  is  edible  after  it  has 
been  roasted  to  expel  the  cardol  which  it  con- 
tains ;  the  cardol  tnus  obtained  is  used  at  Goa 
for  tarring  boats,  and  as  a  preservatiye  of  wood- 
work (Dymock,  Pharm.  J.  [3]  7,  730).  In 
addition  to  cardol,  the  nuts  contain  anacardic 
acid,  and  an  oily  matter  which,  by  exposure  to 
the  air  on  linen,  siveB  a  brown  stain,  which  is 
very  permanent,  out  does  not  become  black. 
It  has  been  recommended  as  a  marking  ink, 
and  is  used  for  giving  a  black  colour  to  candles 
(Bottger,  Dinffl.  poly.  J.  205,  490).  From  the 
stem  of  the  ^ant  a  gum  exudes  which  is  said 
to  be  used  by  book-bmders  in  South  America. 

The  kernels  contain  47*2  p.c.  of  a  fatty  oil, 
having  tiie  following  characteristics : — Saponifi- 
cation value,  187 ;  iodine  value,  77-83*6 ; 
refraction  in  Zeiss'  butyro-refractometer  at  25°, 
581-58-8  (Theopold,  Pharm.  Zeit.  1909,  1057). 

J.  L. 

AMACARDIUM  ORIENTALE  (the  '  marking 
nut  tree ')  grows  in  the  hotter  parts  of  India, 
the  West  IndieB,  and  in  Northern  Australia. 
It  is  now  termed  Semecarpua  anacardium. 
As  met  with  in  commerce  the  nut  is  a 
black  oval  substance,  from  which,  when  cut,  a 
black  viscid  juice  exudes.  This  produces  a 
light  brown  stain  on  linen,  but  gradually  darkens 
on  exposure  to  the  air,  and  then  resists  the  action 
of  adds,  alkalis,  and  chlorine.  The  native 
method  of  preparing  marking  ink,  is  to  express 
the  juioe  from  the  unripe  fruit  and  to  mix  it 
with  quicklime.  The  (uied  juioe  is  also  used 
in  the  preparation  of  a  black  varnish. 

Kindt  (I>iiigl.  polv.  J.  1859,  165,  158)  pre- 
pared a  marking  ink  from  the  nut  by  extracting 
it  with  a  mixture  of  alcohol  and  ^her,  ana 
evaporating  the  extract.  Tins  ink  produced 
characters  which,  when  moistened  witn  a  lime 
water  or  alkali  solution,  became  black,  and 
were  then  not  completely  removed  when  boiled 
with  hydrochloric  add  and  potassium  chlorate. 

G.  A.  M. 

AMASTHETICS.  There  are  two  principal 
types  of  anesthesia,  or  loss  of  sensation  sufficient 
to  allow  of  surgical  operations  without  pap* 
In  general  ansstheeia,  total  or  partial  insensibility 
and  loss  of  muscular  power  are  produced  by  the 
action  of  drugs  on  tne  brain,  carried  there  in 
the  circulation;  extensive  operations  on  any 
part  of  the  body  can  then  be  done.  In  regional 
ansnthesia,  insensibility  to  pain,  with  or  without 
muscular  paralysis,  JB  proauced  by  the  action 
of  anaesthetic  drugs  on  the  part  where  operation 
is  contemplated.  Regional  anaesthesia  can  be 
produced  (a)  bv  the  infiltration  of  the  actual 
tissues  to  be  lacerated  with  some  substance 
which  paralyses  the  endings  of  the  nerves  that 
convey  painful  sensations;  (6)  by  a  similar 
infiltzmtion  of  the  laige  or  small  nerve  trunks 
supplying  the  field  <3  operation;  (c)  by  the 
injection  into  the  spinal  theoa  in  the  vertebral 
canal  of  a  substance  which  paralyies  the  nerves, 


both  sensory  and  motor,  at  their  entrances  into 
or  exito  from  the  spinal  cord ;  (a)  and  (6)  are 
usually  classified  together  as  local  anesthesia, 
while  (c)  is  spoken  of  as  apinal  anesthesia, 
which  reeemblBB  general  anesthesia  inasmuch 
as  it  causes  loss  of  sensation  and  muscular 
power  together  over  a  wide  region,  and  local 
anaesthesia  in  that  consciousness  is  not  lost  and 
the  anesthetic  is  not  difFused  in  the  circulation. 

Loeal  ansBsthetles.  Very  little  is  known  of 
the  action  of  these  on  the  tissues  with  which 
they  come  in  contact.  The^  are  all  protoplasmic 
poisons  which  have  a  special  preferential  action 
upon  nervous  structures.  Those  in  common  use 
are :  cocaine  (methyl  -  benzoyl  -  epgonine  : 
OitH.iNOi)  ;  stovaine  (hydrochloride  of  ethyl- 
dimethyl  -  amino  -  propinol  benzoato) ;  novocain 
(p-amido-benzoyl-aietnyl-amino-ethenol  •  hydro- 
chloride) ;  tropacocaine  (benzoyl-pseudo-trope- 
ine-hydrochlonde) ;  3-eucaine  (benzoyl -vinyl- 
diacetone-alkamine) ;  /3-eucaine  lactate ;  alypin 
(hvdrochloride  of  benzoyl-tetramethyl-diamino- 
ethvl-dimethyl-carbinol) ;  quinine  and  urea 
hydrochloride ;  nirvanine  (hvdrochloride  of 
diethyl  -  glycoU  •  p  -  amido  -  orthohvdrobenzoic  • 
methyl-ester) ;  holocaine  (hydrochloride  of  p- 
dietho^ethenyl-diphenyl-amidine) ;  aooine  (oi- 
p-anisyf-mono-phenethyl-gnanidine  hydrochlo- 
ride) ;  orthoform  (methyl-p-amino-meta-oxy- 
benzoate);  anesthone  or  anesthesin  (ethyl  ester 
of  j»-aminobenzoio  acid);  apothesine  (oinnamic 
ester  oi  7-diethyl-amino-aIoohol  hydrochloride).^ 

Braun  has  formulated  postulates  for  apprais- 
ing local  anesthetics.  Omitting  one  whicn  has 
not  secured  general  assent,  they  are  : 

(1)  Low  toxicity  in  proportion  to  local 
anaesthetising  power. 

(2)  Solubihty  in  water  to  2  p.c.  at  least ;  and 
stebility  of  the  solution,  wmch  should  keep 
without  deteriorating  and  be  capable  of  sterilisa- 
tion by  boiling. 

(3)  Non-irritobility  to  the  tissues,  and 
freedom  from  after-effecto  when  absorbed  into 
the  circulation. 

(4)  Compatibility  with  suprarraal  extract. 
Acoine,   holocaine  hydrochloride,   anesthe- 

sine,  and  orthoform  are  more  or  less  insoluble. 
Cocaine  and  eucaine  are  not  soluble  in  water ; 
but  their  salts,  and  the  other  drugs  in  the  above 
list,  are  freely  soluble  and  will  keep  without 
deteriorating.  (]k>caine  solutions  cannot  be 
boiled,  but  stovaine,  novocain,  /3-eucaine  lactete, 
tropacocaine,  alypin,  and  nirvanine  can  be  thus 
steriUsed,  at  115^  if  necessary. 

The  most  powerful  anaesuietio  action  is  that 

of    stovaine.     Next    are    cocaine,    novocain, 

tropacocaine,    alypin,    and    jS-eucaine    lactete, 

which  are  all  about  equal.     The  others  have 

inferior  actions  in  this  respect.    Experimente 

on  mice  and  rabbito  have  resulted  in  the  following 

teble  of  relative  toxicity,  cocaine  being  taken  as 

the  unit  *  : — 

Alypin,  1*25  Stovaine,  0*625 

Cocaine,  1*00  Novocain,  0*490 

Nurvanine,  0*714  /3-eucaine  lactete,  0*414 

The  irritant  action  of  stovaine,  tropacocaine, 

and  i3-eucaine  lactete  is  ^rreater  than  that  of 

cocaine ;  that  of  novocain  is  leas.    All  these  five 

are  compatible  with  suprarenal  extract  if  the 

>  8lr  F.  W.   Hewitt  and  Dr.  Henry   Sobhuon'i 
AaiMthetioi  and  their  Administration,  6th  edit. 
*  Le  Brooq,  Pharm.  J.  IvK)0.  074. 


220 


ANiSSTHETIOS. 


Bolations  are  fresh  mixed  for  each  case.  They 
are  eztensiyely  employed ;  but  novocain  is 
evidently  the  best  yet  discovered  for  routine 
use. 

Local  anesthetics  axe  used  dissolved  in 
water  or  in  normal  saline  solution.  It  is  not 
essential  that  they  should  be  injected  subcutane- 
ously ;  where  the  surface  tissues  are  deUcate,  as 
on  the  eye,  larynx,  tongue,  tonsils,  simple 
contact  with  a  lo<^  aniesthetio  in  solution  or  in 
fine  powder  will  destroy  sensation  sufficiently 
for  many  surgical  procedures.  But  elsewhere 
the  solution  is  injected  with  a  hypodermic 
syringe  into  the  tissues  which  are  to  be  rendered 
anosthetic.  If  suprarenal  extract  be  mixed 
with  the  ansBSthetic  solution,  contraction  of  all 
the  minute  blood-vessels  in  the  locality  takes 
place.  Thus  the  drug  is  retained  longer  in  the 
tissues  about  the  site  of  injection,  instead  of 
being  rapidly  dissipated  in  the  lymph-stream. 
Consequently  a  more  intense  and  lastii^,  because 
more  strictly  local,  action  occtus.  The  presence 
of  0*4  p.c.  of  potassium  sulphate  also  intensifies 
the  action  of  some  local  anaesthetics,  especially 
of  novocain. 

Local  anscsthesia  can  also  be  obtained  by 
freezing  the  superficial  tissues.  A  fine  jet  of 
ether  or  ethyl  chloride  is  directed  on  to  the 
desired  portion  4Df  the  skin,  and  when  the  latter 
is  frozen  a  cut  can  be  made,  as  for  a  whitlow, 
boil,  or  other  small  abscess,  without  causing 
pain. 

Spinal  anSBstheties.  Some  of  the  same  drug^a 
which  cause  local  anaesthesia  are  available  for 
injection  into  the  cerebro-spinal  fluid  with  which 
the  spinal  cord  is  surrounded  in  the  vertebral 
canal.  Stovaine  is  most  used  in  Britain,  but 
novocain  and  tropacocaine  also  are  popular  in 
Europe.  The  method  was  introduced  Dy  Bier 
in  Germany  in  1890,  and  since  1907  has  been 
very  extensively  tried  all  over  the  world.  The 
balance  of  opinion  is  that  for  ordinary  cases 
spinal  anaesthesia  is  too  dangerous  to  replace 
general  anaesthesia ;  but  that  for  certain  cases 
where  the  latter  entails  especial  risks,  it  is  of 
undoubted  utility.  Barker  ^  and  McGavin,' 
who  are  the  most  prominent  advocates  of  spinal 
aniBBthesia  in  England,  use  a  solution  of  stovaine 
in  6  p.c.  glucose.  Of  late  years  solutions  which 
are  as  light  as  the  cerebro-spinal  fluid  (sp.gr.  1  *006 
to  1*007)  have  been  extensively  used,  m  place  of 
the  heavy  glucose  solutions.  Many  anaesthetists 
use  morphine  with  or  without  scopolamine 
(hvoscine)  as  a  preliminary,  injected  hypoderml- 
cally. 

General  anafthetleai.  There  are  many  sub- 
stances which  diminish  or  abohsh  the  perception 
of  pain  ;  but  only  a  few  of  these  are  neely  used 
as  general  anaesthetics.  The  conditions  which 
must  be  fulfilled  to  obtain  admission  to  the  list 
are*: 

(1)  To  produce  absolute  insensibility  to  pain 
without  causing  any  great  discomfort  during 
induction. 

(2)  To  produce  loss  of  all  voluntary  and  many 
reflex  movements. 

(3)  To  be  capable  of  being  readily  introduced 

>  British  Hedksl  JounuU,  1908,  U.  453  (sad  other 
MtP6rs)> 

*  Olinical  Jojrnsl,  M^^"**,  1914. 

3  B.  W.  CoUum,  The  Practice  of  AoMthetlcs,  1009. 
14. 


into  the  system,  and  rapidly  eliminated,  after 
the  completion  of  the  operation,  without  injury 
to  the  patient. 

(4)  To  act  in  a  regular  and  constant  wa^,  so 
that  the  effects  can  be  controlled  by  the  admiiiis- 
trator. 

The  general  anaesthetics  in  use  in  Great 
Britain  are  four  in  number :  nitrous  oxide,  ethyl 
chloride,  ether,  chloroform.  Ethyl  bromide, 
ethidene  dicfaloride  (dichlorethane),  bichloride 
of  methylene,  and  amylene  (pent-al)  are  obsolete. 
Hedonal  (methyl-propyl-carDinol-uretiiaiie)  and 
urethane  itself  have  also  been  used  as  general 
anasthetics,  by  direct  injection  in  solution  in 
normal  saline  into  the  blood  stream.^  In 
America  and  on  the  Gontinent  anaesthol,  somno- 
form,  and  narootile  axe  also  employed.  Anaesthol 
is  a  mixture  of  chloroform,  ether,  and  ethyl 
chloride,  in  molecular  proportions ;  somnoform 
is  ethyl  chloride  60  parte,  methyl  chloride 
35  parts,  ethyl  bromide  6  parts ;  narootile  has 
been  steted  to  be  a  compound,  but  analysis  has 
shown  it  to  be  a  mixture  of  methyl  chloride, 
ethyl  chloride,  and  ether.  Mixtures  of  ether 
and  chloroform  in  various  proportions  are  in 
common  use  everywhere.  Morphine,  chloral, 
cannabis  indica,  and  many  other  drugs  have 
analgesic  and'  ansesthetio  properties ;  some  of 
them,  morphine  especially,  are  used  to  assist 
the  action  of  the  volatile  annsthetics. 

The  effeote  of  a  general  anaesthetio  are  pro- 
duced by  the  circuGition  in  the  blood  of  the 
drug  employed.  When  it  reaches  the  brain  the 
phenomena  of  anflssthesia  are  exhibited  :  at  first 
slightly,  then  with  increasing  doses  more  and 
more  mtoisely,  until  with  a  sufficient  quantity 
death  results.  The  phenomena  of  general 
anaesthesia  are  the  same  whether  absorption 
takes  place  through  the  lun^,  rectum,  skin, 
blood  stream,  or  gastro-intestmal  tract.  Thus 
alcohol  has  a  matrked  anaesthetio  effect,  familiar 
in  the  indifference  of  a  drunken  man  to  injury. 

The  easiest  way  of  introducing  into  the  blood 
any  substance  which  is  a  gas  or  a  volatile  liquid 
is  by  means  of  the  longs.  The  blood  thus 
chaived  wjth  an  anaesthetic  is  rapidly  delivered 
to  tne  nervous  centres,  in  which  the  essential 
changes  of  general  anaesthesia  take  place.  The 
absorption  of  vapours  in  the  lungs  varies  with 
numerous  factors:  barometric  pressure,  tem- 
perature of  the  vapour  and  of  the  blood,  rate  of 
respiration,  and  rate  of  blood-flow  through  the 
pumonary  system.  But  the  pocess  is  also 
something  more  than  simple  solution  by  diffusion 
of  gases  through  a  thin  membrane ;  there  is  at 
least  an  element  which  depends  on  the  fact  that 
the  tissues  concerned  are  living. 

The  lungs  are  also  the  chief,  but  not  the 
only,  medium  for  the  elimination  of  inhaled 
anaesthetics.  These  are  but  little  deoomnosed 
during  their  tour  of  the  circulation,  and  the 
greater  part  is  discharged  unchanged  after  the 
administration  is  suspended.  What  change 
they  undergo  in  the  blood  is  vecy  unoertain. 
Chloroform,  which  has  hitherto  received  mora 
attention  in  this  respect  than  the  others,  is 
recoverable  from  the  blood  in  fatal  cases  of 
chloroform  anaesthesia,  but  it  is  believed  that 
most  of  it  circulates  in  the  red  corpuscles  of  the 
blood   in   combination   with  the  lecithin  and 

1  Lancf't   March  28,  1912;   and  Brit.  Msd.  Juoc 
June  16.  Ittii. 


ANJBSTHETIOS. 


elioleiterin  which  they  ecmtain.^  fflfouiuuie 
Mid  not  uiioomiiiOEily  appean  in  the  nraiA  after 
chkjrofofui  anaatheda.  Nitrons  and  aolphnr 
an  abo  excreted  in  the  urine  in  greater  quantity, 
indicating  a  greater  destmction  of  proteid ;  and 
the  increase  of  chlorides  is  held  to  show  that 
some  chloroform  is  decomposed  in  the  body. 
The  affinity  of  cholestcrin  aiMl  lecithin  for  chloro- 
form, chloral,  ether,  solphonal,  tetronal,  tri<ma]« 
and  chloialaniide  has  been  suggested  as  the 
explanation  for  the  seXeotiye  action  of  these 
narcotics  on  *the  central  nervous  systr^m,  which 
contains  a  laner  proportion  of  cholesterin  and 
lecithin  than  do  the  other  organs.  With  regud 
to  ether,  Tumbull  states  that  etherisatioo 
produces  a  marked  diminution  of  the  hsmogiobin 
of  the  Uood  ' ;  and  Reicher  finds  three  times 
the  nonnal  quantity  of  fat  present  in  the  Uood, 
together  wiui  an  increased  amount  of  acetone, 
due  to  the  disintegration  of  fat  and  albuminoid 
bodies. '  The  chemical  composition  of  the  blood 
is  often  much  modified  during  anssthesia,  be- 
cause the  air  supply  to  the  lungs  is  frequently 
curtailed  to  a  ereater  or  less  extent^  and  the 
elimination  of  00^  hindered.  The  proportions 
of  O  and  CO,  in  the  circulating  blood  may  thus 
be  altered  at  the  expense  of  Uie  former,  and  an 
asphyxial  element  added  to  the  narcotic  effect 
of  the  annsthetic.  Some  authorities  betieTe 
that  deprivation  of  oxygen  ia  the  method  by 
which  all  anssthetios  produce  their  action  on 
the  nervous  tissues. 

The  chemical  changes  which  may  be  assumed 
to  take  place  in  the  brain  during  anaasthesia  are 
unknown,  as  indeed  are  those  of  natural  sleep. 
It  has  been  suggested  that  unstable  compounds 
are  formed  between  the  annsthetio  and  the 
protoplasm  of  the  nerve  oeUs,  and  some  ob- 
servers describe  changes  xeooffnisable  micro- 
scopically in  those  ceUs  as  a  result  of  anesthesia. 
Professor  Hans  Meyer  holds  that  there  is  a  loose 
physico-chemical  combination  with  the  lipoids  of 
the  celL  This  causes  inhibition  of  the  norma] 
metabolism  until  the  loose  reversible  combina- 
tion breaks  up.  A  rare  sequel  of  chloroform 
ancesthesia  is  known  as  delayed  chloroform 
poisoning.  Hie  symptoms  of  this  condition, 
which  is  sometimes  &tal,  arise  about  eighteen 
to  seventy-two  hours  after  the  aniesthesia.  They 
are  attributed  to  '  acidosis,'  that  is  to  diminished 
alkalinity  of  the  blood  due  to  the  presence  of 
acetone  and  aoeto-acetio  acid,  which  can  be 
detected  in  the  urine  and  the  breath.  For  the 
developed  condition  sodium  bicarbonate  in  large 
doses  IS  employed ;  as  a  preventive  measuro 
feeding  on  slucose  for  a  day  or  two  before 
operation  is  round  to  answer  best.  Very  raroly 
indeed  this  acidosis  has  followed  the  adminis- 
tration of  ether. 

Nitrous  oxide  (Laushing  gas). — ^The  inhala- 
tion of  from  three  or  four  to  twenty  or  thirty 
gallons  of  this  eras  without  any  air  produces 
anosthesia.  If  we  administration  is  then  sus- 
poided,  insensibility  lasts  on  an  average  about 
thirty  to  forty-five  seconds,  during  which  time 
minor  operations  such  as  the  extraction  of  teeth 
can  be  undertaken.  A  marked  asphyxial  ele- 
ment is  nearly  always  present,  owing  to  ttte 


>  Hale  White,  Materia  Medica,  11th  ed.  1009.  280. 
*  Laurence  Tnmbul],  Artificial  Antesthesla,  228. 
'  Belcher,  Laooet,  Jan.  25, 1008,  268. 


replacement  of  oxygen  by  NaO  Tf  air  be 
admitted  for  brief  periods  between  successive 
doses  ai  gas,  anasthesia  can  be  maintained 
without  great  difficultv  for  several  minutes.  By 
delivering  nitrous  oxide  mixed  with  pure  oxygen 
for  inhalation,  ansethesia  can  be  piolonsed  for 
any  desired  period.  The  proportions  ol  ttie  two 
gases  are  varied  to  meet  the  requiremente  of 
individual  cases,  but  roughlv  the  mixture  must 
contain  about  80  p.c.  by  volume  of  NgO.  This 
method  is  weU  suited  for  operations  on  the 
limbs,  but  for  abdominal  operations  it  is  difficult 
to  get  the  complete  muscular  relaxation  neces- 
sary. Nitrous  oxide  gas  is  the  safest  known 
general  anosthetio,  and  recovery  takes  place 
very  rapidly  (two  or  three  minutes)  witiiout 
unpleasant  after-effects.  Nitrous  oxide  for 
anesthetic  purpoees  should  be  entirelv  free 
from  other  oxides  of  nitrogen,  and  from  chlorine ; 
small  quantities  of  H,0,  O,  and  N  are  usually 
present  as  impurities,  and  are  of  no  moment. 

Bth^  ehioride. — ^The  vapour  of  3  to  6  ac  of 
this  substance  allowed  to  vdUUlise  in  a  closed 
chamber,  such  as  a  rubber. bag,  into  which  an 
adult  patient  exspires  and  from  which  he  inspires, 
produces  ansBstbesia  very  rapidly.  If  adminis- 
tration ia  then  suspended,  insensibility  lasts 
from  one  to  two  minutes.  By  administering  a 
further  dose  before  recovery  takes  place  from 
the  first  one,  anesthesia  can  be  nrolonged ;  it 
is  preferable,  however,  to  give  etner  or  chloro- 
form or  nitrous  oxide  and  oxygen  if  a  lonser 
anesthesia  is  required.  The  after-effects  of  ethyl 
chloride  are  intermediate  between  those  of 
nitrous  oxide  and  those  of  ether  and  chloroform. 
Ethyl  chloride  given  by  an  expert  is  safer  than 
either  of  the  latter,  but  not  so  safe  as  nitrous 
oxide.  No  impurities  can  be  tolerated  in  ethyl 
chloride  for  use  as  a  general  anesthetic ;  there 
is  no  difficulty  in  securing  complete  purity. 

JBMer.— About  30  p.c  of  au  and  70  p.c.  of 
ethereal  vapour  wiU  produce  and  maintain 
general  anesthesia.  The  vapour  is  so  intensely 
irritating  to  the  mucous  membrane  which  lines 
the  mouth,  nose,  and  air-passages,  that  it  must 
first  be  offered  very  dilute,  and  then  in  a 
gradually  increasing  percentage.  Limitation  of 
air  supply  renders  it  possible  to  procure  anes- 
thesia with  a  much  smaller  quantity  of  ether 
than  when  fresh  air  is  freely  admitted,  for  a 
slight  concurrent  asphyxia  helps  the  action  of 
the  ether.  Such  aspnyxiation  has  disadvantages 
of  its  own  if  allowed  to  exceed  a  very  moderate 
degree ;  it  is  usually  present  durinff  anesthesia 
under  ether  by  the  '  closed '  methods.  There  is 
slightly  more  difficulty  in  producing  aniesthesia 
by  the  *open'  method,  in  which  air  enters 
freely ;  the  preliminary  injection  of  small  doses 
of  morphine  (i  to  ^  grain)  with  atropine  {^l(j 
to  y^  grain)  is  often  practised.  Ether  is  much 
less  dangerous  to  life  than  chloroform  in  the 
operating  room ;  but  part  of  this  advantage  is 
counterbalanced  by  the  occasional  development 
of  bronchitis  and  broncho-pneumonia  afterwards. 
Ether  for  ansesthetio  purposes  should  have  a 
8p.gr.  between  0'720  and  0*722.  Provided 
impurities  have  been  removed,  it  is  of  no  signi- 
ficance whether  rectified  spirit  or  methylated 
spirit  is  used  in  the  manufacture. 

Chloroform, — ^Muoh  research  has  been  carried 
out  to  determine  the  percentage  of  chloroform 
necessary  to  produce  anuE>8tbeBia  by  inhalation. 


222 


AN^^STHETIOS. 


Vernon  Harcomt  introdaoed  early  this  oentuiy 
a  ohloraform  inhaler  capable  of  regolatlnff  this 
proportion  up  to  2  p.c.  Experience  showed  that 
in  occasional  cases  it  is  verv  difficult  or  impos- 
sible to  induce  anipsthesia  with  this  amount,  and 
a  modification  of  the  instrument  allows  air  to  be 
inspired  containing  3  p.c.  In  practically  every 
case  anaesthesia,  when  fully  established,  can  be 
maintained  with  a  2  p.c.  vapour.  Alcock,  who 
has  investigated  the  dosage  of  chloroform  very 
carefully,  finds  ^  that  for  an  ordinary  adult  it 
suffices  to  offer  a  percentage  rising  gradually 
to  2}  in  three  minutes ;  this  as  a  rue  produces 
complete  surgical  anaesthesia  in  eight  or  ten 
minutes.  If  a  higher  proportion  is  necessary, 
3  p.o.  may  be  allowed  at  the  end  of  five  minutes. 
He  finds  that  within  a  few  minutes  after  in- 
duction is  complete  1*5  p.c.,  and  after  half  an 
hour  1  p.c.,  will  usually  be  enough.  Several 
physiologists  have  estimated  the  amount  of 
chloroform  in  the  circulating  blood  during 
aniesthesia :  their  results  vary  from  0*036  to 
0*07  p.0.  Chloroform  is  the  least  safe  of  these 
four  anipsthetics,  especially  in  the  hands  of 
those  whose  experience  as  anspsthetists  ia 
small.  Chloroform  for  anaesthetic  purposes  is 
found  to  keep  better  if  it  contains  0*2  to  0*6  p.c. 
of  alcohol  or  of  ethyl  chloride.  Ko  otner 
impurities  are  tolerable.  It  is  also  less  liable  to 
decomposition  if  kept  in  the  dark.  There  are 
three  commercial  processes  of  inanufacture,ba8ed 
respectively  upon  rectified  spirit,  methylated 
spirit,  and  acetone;  there  is  no  difference  be- 
tween the  actions  of  the  resulting  chloroforms, 
provided  they  are  duly  purified.  H.  R. 

AN^BSTHESINE.      Trade    name  for  ethyl 

p.amino-benzoate  NH,^     NcOOC,H,. 

ANAGTRINE  v.  Cytisinb. 

AMALUTOSorKALMOPTRIN.  Tradenames 
for  ealoium  acetyl  salicylate. 

ANALGESDJE.  Identical  with  antipyrine 
iq.v.), 

ANALYSIS.  Chemical  analysis  is  the  separa- 
tion of  a  complex  material  into  simpler  con- 
stituents. It  is  uUimaU  when  these  component 
parts  are  elementary  forms  of  matter,  and 
proximatt  when  the  subdivision  consists  only 
in  the  separation  of  the  original  substance 
into  less  complicated  compounds.  The  aim  of 
chemical  analvsis  is  twofold :  the  first  object 
is  to  asoertam  the  nature  of  the  compo- 
nents of  a  mixture  or  complex  substance; 
the  second  is  to  determine  the  proportions  in 
which  these  constituents  are  present.  All 
analytical  operations  may  therefore  be  classified 
under  the  two  main  categories  of  gtuilitaiive  and 
quantiiaiive  analysis,  according  as  to  whether 
these  processes  lead  to  the  identification  of  the 
proximate  or  ultimate  constituents  of  a  complex 
substance,  or  to  the  determination  of  the  relative 
proportions  in  which  these  constituents  are 
present. 

This  article  is  written  primarily  from  the 
technical  point  of  view,  and  accordingly  the 
descriptions  given  in  the  qualitative  section  are 
restricted  mainly  to  those  elements  which  find 
application  in  the  arts  and  industries.  Simi- 
larly,  the  estimations  and  separations  outlined 

'  IT  H.  Alcock.  British  Medlcnl  Journal,  Feb.  e, 
1000.  326. 


in  the  quantitative  section  an  chiefly  those 
required  in  the  analysis  of  technically  important 
materials. 

The  systematic  investigation  of  the  individual 
elements  and  their  typical  compounds  has 
revealed  the  existence  of  many  characteristic 
reactions  which  arc  exhibited  by  certain  elements 
and  compounds  under  widely  varying  conditions 
of  combination  or  association.  This  circum- 
stance leads  to  a  simplification  which  is  utilised 
extensively  in  both  qualitative  and  quantitative 
analysia  In  qualitative  work,  such  oharao- 
teristio  reactions  as  are  not  generally  interfered 
with  by  other  substances  enable  the  analyst  to 
detect  tiie  presence  of  certain  elementary  or 
compound  substances  without  undertaking  the 
more  laborious  processes  involved  in  isolating 
these  constituents  from  the  other  ingredients  of 
a  mixture. 

In  quantitative  analypis  two  essentially 
different  methods  of  procedure  are  em- 
ployed, the  more  fundamental  one  being  gravi- 
metric analysis,  in  which  the  elementary  or 
complex  constituent  of  a  mixture  is  isomted 
and  weighed  in  the  form  of  a  definite  compound. 
By  utili^g  quantitatively  the  above-mentioned 
distinctive  reactions  it  is  frequently  possible  to 
adopt  the  second  procedure  known  as  voiumelric 
analyRis,  in  which  the  relative  amount  of  a  certain 
constituent  is  estimated  in  the  presence  of  other 
elements  and  compounds  associated  with  this 
constituent  in  the  mixture  under  examination. 

For  the  purposes  of  scientific  investigation 
the  most  accurate  methods  are  essential,  and 
these  are,  in  the  main,  gravimetric  in  cha- 
racter ;  but  for  technical  requirements  extreme 
accuracy  is  rarely  required,  and  rapid  methods 

O  approximately  correct  results  are  pre- 
to  more  exact  processes  involving  a 
longer  time  for  their  execution.  It  is  in  this 
direction  that  volumetric  analysis  has  been  most 
extensively  developed,  the  general  tendency  in 
industrial  laboratories  being  to  replace  gravi- 
metric methods  by  quicker  volumetric  processes 
with  very  little  loss  in  accuracy,  provided 
that  certain  essential  conditions  be  fulfilled. 

General  Operations. 

Sampling. — It  is  of  the  highest  importance 
that  the  sample  under  examination  should  be 
truly  representative  of  the  bulk  of  the  substance. 
Discrepancies  between  the  results  of  different 
analysts  are  usually  attributed  to  faulty 
methods  or  inaccurate  work,  but  in  many  cases 
they  are  really  due  to  imperfect  sampling.  If 
the  substance  is  a  liquid,  the  contents  of  the 
vessel  should  be  thoroughly  mixed  before  the 
sample  is  withdrawn.  If  the  substance  is  con- 
tained in  several  vessels,  a  proportional  quantity 
should  be  taken  from  each,  the  different  portions 
mixed  together,  and  the  final  sample  taken  from 
the  mixture. 

In  the  case  of  solid  products  oare  must  be 
taken  to  secure  a  proper  proportion  of  large  and 
small,  hard  and  soft  fragments.  If  a  ship's 
cargo  is  to  be  sampled,  portions  should  be 
taken  from  different  parts  of  the  bulk ;  if  the 
substance  is  contained  in  railway  trucks,  por- 
tions should  be  taken  from  the  ends  and  middle 
of  each  truck.  When  the  substance  is  in  bags 
or  barrels,  a  long  hollow  auger  is  thrust  to  the 
bottom  of  each  and  then  withdrawn,  bringing 


irltli  it  >  loofc  eon  of  tbc  nib«Uoe«.  If  tha 
msterial  kMM  ot  gutu  moutora,  or  oailcTgocB 
>iij  other  ohkiige  on  ezponn  to  >ir,  u  in  the 
cK.'ie  of  aokp  or  ouutic  kmIa,  k  proper  ptDportion 
of  the  intemil  uid  extenul  porlioiis  most  bo 
takeo.  In  •£  oaaei  the  fint  Mnplea  tn  brokni 
into  unall  piaoaa,  thoroughlf  mixed,  mad  one- 
fourth  tftken  for  fnrther  trntmcot.  Thia  is 
gioond  to  powder,  n^un  thonnighl;  mixed,  tad 
one-fourth  taken,  lie  mbdiTisian  is  repeated, 
if  neceasuy,  and  the  Giml  sample  kept  in  well- 
eloaed  bottW.  This  proooaa  of  '  quartrring  ' 
may  alw  be  etteoted  bj  sin«wling  out  the  Boclj 
powdered  material  in  the  form  of  a  flattaned 
cylinder  dividing  this  ladially  into  four  parta, 
taking  oat  the  opposite  sectors,  mixing  these 
thoroughly,  and  repeating  the  aabdivision. 

If  uie  mixture  is  soft  and  friable,  polTrrisa- 
tkm  B  readily  effM>t«d  in  a  porcelain  or  earthen- 
ware mortar,  bat  harder  subetjuicca  should  be 
powdered  in  a  oait-iron  or  Bt«el 
mortar.  When  the  lubstanoe  is 
haid,  and  a  very  fine  powder  ia 
required,  an  agate  mortar  sboold 
be  used  for  the  final  operation,  so 
that  the  powder  may  be  oomptetely 
■ifted  tluoDgh  fine  muslin.  Ve^ 
hard  sabstancea,  sooh  as  minerals, 
■re  first  broken  into  small  pieoes 
by  wrupping  tbem  in  paper  and 
striking  with  a  hammer,  Oind  are 
then  fnrther  crushed  in  a  steel 
mortar  (¥^.  1)  consisting  of  a  strong 
base  with  a  cironUr  reoess  into  which 
fits  a  movable  stoel  ring  or  guard. 
and  inside  this  is  a  solid  steel 
piston  which  acts  as  a  pestle.  A 
•mall  quantity  of  tba  mineral  is  placed 


which  drive*  il 


the  mineral.     The 


final  crushing  is  done  in  an  agate  mortar. 

The  mechanical  ore-griiider  deaorifaed  in 
Hillebrand's  Analysis  of  Silicate  and  Carbonate 
Rooks,  may  likewise  be  employed  in  reducing 
bard  minerals  to  a  fine  powder. 

Drying. — Many  snMtanoea  absorb  more  or 
leas  moistnre  when  exposed  W  the  air,  and  in 
order  to  bring  them  into  a  definite  condition  tor 
analysis,  it  is  desirable  that  they  should  be  dried, 
this  operation  being  oondnoted  at  the  ordinary 
or  at  a  hi^er  temperature  according  to  circum- 
■tancea.  Substances  which  oontsin  water  in 
combination  are  mually  dried  by  exposure  to  air 
or  by  pressure  between  fold*  of  filter  paper.  In 
othtn'  cases  where  a  higher  temperature  n-ould 
be  injnrious  the  substance  may  be  placed  under 
a  bell-jar  wUch  also  incloses  a  didi  containing 
sulphuric  acid.  The  operation  proceeds  more 
quickly  it  the  bell-jar  is  connected  with  an  air- 
pump  and  thus  rendered  vacuous. 

Substances  which  do  not  decompose  at  100* 
are  beet  dried  in  a  copper  oven  provided  with  a 
jacket  containing  water  which  is  heated  to 
boiling,  the  water-level  being  kept  constant  by 
means  ot  an  overflow  a  and  feeding  arrangement 
at  the  side.  The  mside  of  the  oven  ia  flttt-d 
with  a  perforated  shelf  which  supports  diihps, 
fannelsi&c.  (Fig.  2). 

When  the  substance  is  sufficiently  stable  it 
isadvisaUetodryat  116'-120',sinoean  inoreas* 


Via.  2. 

without  a  jacket,  heated  by  a  lamp  underneath  ; 
or  toluene,  boiling  at  110*,  may  be  used  instead 
of  water  in  the  oven  with  a  jacket;  crude 
xylene  wiU  give  a  higher  temperature  (129°). 
Inside  the  oven  at  a  little  diatanoo  from  the 
bottom  is  a  shelf  which  supports  the  vessel 
containing  the  cubstanoe.  At  the  top  of  the 
oven  are  two  apertures,  one  of  which  serves, 
la  promote  a  current  of  air  through  the  oven, 
whilst  the  other  carries  a  thermometer  the  bulb 
of  which  is  close  beside  the  vessel  which  Is  being 
heated  (cf.  Huntlj  and  Coste,  J.  Soa  Chem. 
Ind.  1913,32,62). 

If  it  is  desired  to  keep  the  temperature  coo- 
Btant  for  a  long  time,  the  oven  must  be  provided 
with  a  thermort^ulator  (c.  Thibnobbouutobs). 

IFn^Ain;.— The  balance  and  the  precautions 
to  be  observed  in  weighing  form  the  subject  of  a 
special  article  (c.  Balanci).  As  a  rule,  mb- 
Btances  token  for  analysis  nbonld  be  weighed 
from  tubes  provided  with  well-fitting  stoppers  or 
corks,  or  from  weighing  bottim  GttM  with  glass 
capsule  stoppers,  the  diScrence  between  the 
weight  of  the  tube  or  bottle  before  and  after 
the  removal  of  the  substance  giving  the  weight 
taken  for  analysis.  The  quantity  required  for 
an  analysis  will  depend  upon  citcnmstanoes. 
When  constituents  present  m  minute  quantity 
have  to  be  estimated,  a  relatively  large  amount 
of  the  subatanoe  is  required,  but  for  the  estima- 
tion of  one  or  two  oonstituente  from  1  to  2  grams 
of  the  substance  is  usually  sufficient.  The 
smaller  the  quantity  of  matter  operated  upon, 
the  shorter  the  time  required  for  filttation, 
washing,  to.,  but  also  the  greater  the  demsods 
on  the  skill  and  accuracy  of  the  operator. 

Hygroscopic  an bstancesand  precipitate*  most 
be  kept  under  a  itticcator  {q.v.),  i.t.  a  glass  dlnb 
containing  sulphuric  acid  or  calcium  chloride, 
fitted  with  a  tiiiy  to  support  a  orucible,  Ac,  and 

Eivided  with  an  air.tight  gloss  cover,  preferably 
U-sbnped.     Crucibles    containing    nonhygro- 
soopic  precipitates  may  be  oltowed  to  oool  wiUi 


224 


ANALYSia 


expotare  to  air,  proTided  that  the  empty  cnioiblet 
were  allowed  to  ood  under  the  aame  conditioiis 
before  weighins. 

SohUion. — ^The  eolation  of  a  substance  is 
most  conveniently  effected  in  flasks  or  in  some- 
what deep  beakers  which  are  inclined  at  an 
angle  in  order  to  prevent  possible  loss  by  spurt- 
ing. The  operation  may  bo  accelerated  by  neat, 
and  the  reagent  should  be  used  in  the  most 
concentrated  form  possible  and  in  the  least  pos- 
sible ezoesB,  in  order  to  avoid  loss  of  time  in 
evaporation,  ftc.  Evaporation  to  expel  excess 
of  solvent  should,  where  possible,  be  conducted 
in  the  same  vessel. 

Evaporation, — ^The  evaporation  of  a  liquid 
may  be  effected  over  an  ordinary  bunsen  flame, 
or  over  a  rose  burner,  care  being  taken  that  the 
liquid  does  not  boil.  If  the  operation  is  con- 
ducted in  a  flask  or  crucible,  the  latter  should  be 
inclined  in  order  to  prevent  loss  by  ebullition, 
and  the  operation  is  accelerated  in  the  first  case 


Fio.  3. 

by  drawing  a  current  of  air  through  the  flask,  in 
the  seoonoT  by  inclining  the  lid  of  the  crucible 
(Fig.  3)  across  the  month  of  the  vessel  and  thus 
prc^uoing  a  droulatioD.  The  rate  of  evapora- 
tion, toderu  paribus,  depends  on  the  area  of 
surface  exposed,  and  hence  the  operation  is 
effected  most  quickly  in  shallow  dishes,  especially 
if  a  current  of  air  removes  the^.sapqjir  as  fast 
as  it  is  eiveD  off.  During  the  process  the 
contents  of  the  dish  should  be  protected  from 
dust,  &c.,  and  this  is  really  done  by  supporting 
at  a  distance  of  about  six  inches  above  the 
purface  of  the  dish  a  triangle  of  glass  rod  or 
tubing  on  which  is  stretched  a  sheet  of  filter 
paper  freed  from  soluble  compounds  by  treat- 
ment with  acdd.  When  evaporation  over  a 
direct  flame  is  imjnaoticable,  the  dishes,  &c., 
should  be  placed  on  a  tDater4>aih,  that  is,  a 
vessel  contaming  boiling  water,  in  such  a  way 
that  they  arc  heated  by  the  steam.  The  top  of 
the  water  drying-oven  already  described  (Fi^.  2) 
may  be  provided  with  a  series  of  rings  of  various 


sizes  and  thus  serves  two  porposes.  Ordinary 
tin  cans  or  copper  vessels  of  similar  shape  will 
answer,  but  in  all  oases  it  is  desirable  to  have 
an  arrangement  for  keeping  the  water  at  a  con- 
stant level. 

PrecipUation  is  conducted  in  beakers,  dishes, 
or  conical  flasks,  but  not  in  ordinary  round 
flasks  because  of  the  difficulty  of  removing  the 
precipitate.  Glass  veisels,  especially  when  new, 
are  appreciably  attacked  and  dissolved  by  water, 
and  still  more  strongly  by  alkaline  solutions, 
the  action  increasing  with  the  concentration  of 
the  solution  and  the  duration  of  contact.  For 
quantitative  work  Jena  glass  vessels  should  bo 
used,  as  these  are  least  a&oted  by  alkalis. 
Acid  liquids,  with  the  exception  of  dilute  sul- 
phuric acid,  have  less  solvent  action.  Porcelain 
vessels,  especially  after  they  have  been  used  for 
a  short  time,  are  not  appreoiably  attacked 
(Fresenius's  Quant.  AnaL).  All  precipitations 
involving  long  heating  with  alkaline  liquids 
should  be  conducted  in  porcelain  vessels  or  in 
platinum,  silver,  or  nickel  dishes.  Silica-ware 
vessels  can  be  used  with  all  acid  liquids  except- 
ing those  evolving  hydrogen  fluoride  (Zeitach. 
anon.  Chem.  1905,  44,  221). 

Unless  oiroumstances  forbid,  the  liquid  and 
the  reagent  should  be  heated  to  boiUn^  and 
mixed  nadually  with  continual  agitation,  since 
under  uiese  condltkms  precipitation  as  a  rule  is 
more  rapid  and  complete,  and  the  precipitate 
is  obtained  in  a  d^nse  and  granular  form  and 
is  readily  separated  and  washed.  Usually  filtra- 
tion may  be  commenced  as  soon  as  the  super- 
natant bquid  is  dear,  or  at  any  rate  after  two 
or  three  hours.  An  unnecessary  excess  of  reagent 
should  always  be  avoided,  but  in  aU  oases  com- 
plete precipitation  should  be  proved  by  adding 
a  small  quantity  of  the  reagent  to  tiie  clear 
liquid. 

FiUraiUon. — ^The  separation  of  a  precipitate 
from  a  Bquid  is  usually  effected  by  means  of  a 
specially  prepared  variety  of   blotting  paper, 
known  as   filter  paper.    The  Swedish    paper 
made  by  J.  Munktell  has  the  oldest  reputation, 
I  but  that  known  as  Whatman  paper,  made  by 
'  W.  &  R.  Balston,  Ltd.,  is  of  excdlent  quality, 
,and  for  many  purposes  answers  better.    The 
latter  firm  supply  paper  which  has  been  treated 
with  Wdrochloricand  hydrofluoric  acids,  and  thus 
freed  mm  almost  all  inorganic  matter.     It  is  de- 
sirable that  all  paper  used  in  quantitative  work 
should  be  free  from  soluble  compounds,  and  this 
end  is  secured  by  soaking  the  orduiary  filter 
paper  for  three  or  four  hours  in  pure  hydro- 
,  chloric  add  diluted  with  16-20  times  its  volume 
'  of  water,  and  then  washing  thoroughly  to  remove 
I  all  traces  of  acid  and  soluble  salts.    The  paper 
IS  conveniently  kept  in  circular  pieces  of  known 
radii  (2,  4,  6,  6,  8  cm.),  and  the  ash  loft  by  each 
size  diould  be  determined  once  for  all  by  in- 
cinerating six  filters  of  one  of  the  medium  sixes 
in  the  manner  described  under  the  treatment  of 
precipitates,  and  weighing  the  ash  which  is  left. 
This  quantity  divided  by  six  gives  the  average 
amount  of  aui  left  by  one  filter  of  that  size,  and 
the  amount  left  by  the  other  sixes  is  readily 
calculated,  the  quantity  of  ash  being  propor- 
tional to  the  area  of  the'paper. 

Usually  the  filter  paper  is  supported  in  a 
^lass  funnd  which  should  have  smooth  even 
sides  and  an  angle  of  60*.     The  stem  should  be  . 


ANALYSIS. 


225 


■omewhat  long  and  not  too  wide,  with  the  lower  i 
end  cut  obliquely.  A  ciiouiar  filter  ia  folded  in 
half,  Umo  in  a  qnadiant^  and  when  the  quadxant 
is  opened  at  one  side  it  foraiB  a  hollow  cone, 
which  ahoiiid  fit  aoourately  into  the  funnel 
The  edge  of  the  filter  paper  should  be  about 
10  mm.  below  the  edee  of  the  funnel,  and  the 
eize  of  the  filter  Blu>iud  be  such  that  it  in  not 
more  than  three  quarters  filled  by  the  pieoi- 
pitate.  After  placing  the  filter  in  position  it  is 
moistened  with  water,  and  fitted  aocuiately  to 
ti&e  glass,  care  being  taken  to  remove  all  air 
bnhUesfirom  between  the  glass  and  the  paper. 
Attention  to  these  points  greatly  facilitates  tiic 
subsequent  filtration.  The  edge  of  the  vessel 
contaming  the  liquid  to  be  filtered  is  slightly 
gTMised  outride,  and  the  liquid  is  directed  into 
the  filter  by  means  of  a  glass  rod,  care  being 
taken  not  to  disturb  the  preApitate  until  most 
of  the  clear  liquid  has  pasMO  through.  It  is 
advisable  to  keep  the  filter  well  filled  with  the 
liquid,  but  the  latter  must  not  rise  higher  than 
10  mm.  bdow  the  top  of  the  paper. 

In  order  to  accelerate  filtration  a  glass  tube 
about  Z-A  mm.  in  diameter  and  not  less  than 
20  cm.  kmg,  bent  into  a  loop  near  its  upper  end, 
may  he  attached  to  the  stem  of  the  funnel  by 
means  of  indiarubber  tube. 

Greater  rapidity  of  filtration  is  obtained  by 
oaing  one  of  the  numerous  water  pumps  {v. 
FiLTBB  FUVP).  In  this  case  the  liquid  is  filtexed 
into  a  flask  with  stout  walls,  preferably  of  the 
conical  form.  The  stem  of  the  funnel  passes 
through  a  cork  which  fito  in  the  neck  of  the 
flask  and  also  carries  a  tube  connected  with  the 
pamp,  or  the  flask  may  be  provided  with  a  side 
tube  for  this  latter  purpose.  When  it  is  required 
to  filter  into  a  dish  or  beaker,  the  latter  is  placed 
under  a  tubulated  bell-jar  stending  on  a  glass 
l^te,  ^e  oork  carrying  the  funnel,  Ac.,  being 
fitted  into  the  tnbulus  of  the  bell-jar.  If  the 
reduction  of  pressure  is  considerable,  it  becomes 
necessary  to  support  the  apex  of  the  filter.  In 
the  case  of  filters  of  medium  sise  the  necessary 
toughness  is  obteined  bvdropping  into  the  apex 
of  the  dry  filter,  after  itbas  been  fitted  into  the 
funnel,  two  or  three  drops  of  the  strongest 
nitric  acid.  After  a  minute  or  two  the  paper  ia 
washed  and  is  ready  for  use.  Bnnsen's  original 
method  is  to  support  the  apex  of  the  filter  by 

means  of  a  cone  of  platinum 

foil,  which  is  made  in  the 

following  way.     A  circular 

piece  of  thin  platinum  foil 

3-4  cm.  in  diameter  is  cut 

in  the  manner  shown  in  the 

diagram  (Fig.  4),  softened 

by  heating  in  a  flame,  and 

then  plac^  against  a  small 

metal  cone  of  00^  so  that 

the  point  a  coincides  with  the  apex  of  the  cone. 

The  foil  is  then  folded  round  the  metel  so  that  it 

alao  forms  a  small  cone,  which  is  finished  by  being 

pressed  in  a  hollow  conical  mould  into  which 

the  metal  cone  fite.    It  is  then  dropped  into 

the  funnel  and  the  paper  fitted  in.    The  metal 

cones  and  moulds  required  can  be  purchased; 

Bunsen's  method  of  making  a  cone  and  mould 

of  plaster  is  described  in  Thorpe's  Quantitative 

Analysis. 

Carmichael  has  described  a  method  of  reverse 
filtration  (Zeitsch.  anaL  Chem.  10,  83). 

Vol.  L— T. 


The  Gooch  eruoible  (Ohem.  News,  37,  181), 
which  has  a  perforated  bottom  lined  with  a 
thin  asbestos  mat,  has  now  become  a  ieoc»nised 
means  of  coUeotiiig  precipitates.    The  asoestos 
makes  an  excellent  filter,  is  not  affected  by 
ordinary  acid  and  alkaline  liquids,  ia  readily 
dried,  and  does  not  alter  in  weight  when  ignited. 
The  quality  of  the  asbestos  is  of  prime  import- 
ance, a  non-ferruginous  amphibole  being  pre- 
ferable to  the  cheaper  hyourated   varieties  of 
serpentine   which   are   appreciably^   soluble   in 
acids.    Silky  asbestos  is  scraped  into  a  short 
fine  down,  boiled  with  hydrochloric  acid,  well 
washed,  and  kept  in  water.     A  platinum  or  silica 
crucible,  preferably  of  the  low  wide  form,  with 
the  bottom  perforated  with  a  laxge  number  of 
minute  holes,  is  fitted  air-tipht  into  an  ordinary 
funnel  by  means  of  an  indiarubber  ring  placed 
between  the  crucible  and  the  wall  of  the  funnel, 
which  is  fitted  into  a  filtering  flask.    The  pump 
is  set  in  actkm  and  water  containing  the  asbestos 
in  suspension  is  poured  into  the  crucible.   A  layer 
of  asbestos  felt  is  ouickljr  formed,  and  when  uiis 
is  of  sufficient  thickness  it  is  drained,  dried,  and 
ignited  over  a  Ump,  and  the  crucible  is  then 
weighed.     It  is  desirable  to  have  a  non-i»er- 
forated  bottom  to  fit  on  the  crucible  during 
ignition,  in  order  to  protect  the  contenta  of  the 
crucible  from  the  fiame  gases.     A  Soxhlet  tube, 
having  a  perforated  poicelain  or  platinum  disc 
covered  with  an  asbestos  layer  and  supported 
at  the  constricted  part  of  the  tube,  is  &equently 
used  to  collect  precipitates.     Neubauer  recom- 
mends a  perforated  platinum  crucible  with  a 
felted    platinum   mat  (Zeitsch.   anorg.   Chem. 
1901,  922;  e/.  Amer.  Chem.  J.  1909,  31,  406). 
The  weighed  crucible  is  replaced  in  tine  funnel, 
and  filtration  is  conducted  in  the  ordinary  way, 
care  being  taken  that  the  pump  is  set  in  action 
before  tatj  liquid  is  poured  into  the  crucible. 
Drying  and  igniting  the  precipitate  occupies  but 
little   time.     For    gelatmous    precipitates    the 
crucible  mav  be  replaced  by  a  cone,  the  lower 
part  of  which  is  made  of  platinum  gauze  and 
the  upper  part  of  platinum  foiL 

Gooch  has  proposed  (P.  Am.  A.  1886,  390; 
Zeitsch.  anal.  (3hem.  24,  683)  in  special  oases  to 
replace  the  asbestos  by  anthracene,  which  after 
filtration  can  be  dissolved  in  benzene  or  other 
suitable  solvent,  leaving  the  precipitate  undis- 
solved. 

Not  onfrequentlv  it  is  neoeasary  to  keep  the 
contenta  of  a  funnel  hot  during  filtration.  Tlus 
is  effected  by  placing  the  funnel  inside  a  copper 
jacket  filled  with  water  which  is  heated  to  boil- 
ing by  means  of  a  side  tube.  A  simpler  plan  is 
to  coil  lead  pipe  round  the  funnel  and  blow 
steam  through  the  pipe  (Riohter,  J.  pr.  Chem.  (ii.) 
28,  309). 

Sometimes  it  is  desirable  to  avoid  contact 
with  air  during  filtration.  A  convenient  ap- 
paratus for  t^is  purpose  has  been  described  by 
klobukow  (Zeitsch.  anaL  Ghem.  24,  396 ;  J.  Soc. 
Chem.  Ind.  4,  766). 

All  precipitates  require  to  be  washed  in  order 
to  remove  soluble  impurities,  the  liquid  em- 
ployed being  water,  dilute  acid,  dilute  ammonia, 
alcohol,  &c.,  as  the  case  may  require.  The 
object  in  all  cases  is  to  reduce  the  impurity  to 
the  desired  minimum  in  the  shortest  possible 
time  with  the  least  expenditure  of  liquio,  and  it 
can  readily  be  shown  that  successive  treatmenta 


226 


ANALYSIS. 


with  small  quantities  of  the  liquid  are  far  more 
effectual  than  the  same  volume  of  liquid  applied 
all  at  onoe  (Bunscn,  Annalen,  148,  269).  When- 
ever possible  hot  liquids  should  be  used,  and  the 
precipitate  should  be  washed  so  far  as  possible 
oy  decantation,  only  the  washing  liquid  being 
poured  on  the  filter.  The  soluble  impurity 
collects  round  the  top  ed||e  of  the  filter  paper 
by  reason  of  capillary  action  and  evaporation, 
and  hence,  when  washing  is  effected  with  the 
aid  of  an  ordinary  wash-bottle  with  a  movable 
jet,  it  b  important  that  the  liauid  should  be 
directed  on  to  the  top  edge  of  the  filter.  It  is 
also  important  that  each  quantity  of  wash- 
water  should  be  drained  away  as  completely 
as  possible  before  adding  a  fresh  quantity,  and 
it  is  obvious  that  this  takes  place  most  readily 
when  a  pump  is  used.  In  this  case  the  liquid 
is  poured  into  the  funnel  from  an  open  vessel 
to  a  height  of  about  10  mm.  above  iho  edges 
of  the  paper.  Care  must  be  taken  that  the 
precipitate  is  not  drained  so  far  that  ohannek 
are  formed.  It  is  always  advisable  to  ascertain 
whether  the  washing  \a  complete  by  testing  a 
few  drops  of  the  last  wash- water. 

Drying  and  weighing  predpikUea. — Occa- 
sionally a  precipitate  must  be  dried  without  the 
application  of  heat,  and  this  is  accomplished  in 
a  aesiccator  over  sulphuric  acid,  preferably  in  a 
vacuum.  In  other  instances  the  substance  bb 
not  injured  by  a  temperature  of  say  120*,  but 
cannot  be  i^ited.  In  these  cases  the  filter  is 
carefullv  dried  at  the  particular  temperature, 
enclosed  between  a  pair  of  watch-glasses,  and 
weighed.  It  is  then  placed  in  the  funnel  and 
the  operation  proceeded  with.  After  filtration 
the  filter  and  the  precipitate  are  thoroughly 
dried  at  the  same  temperature  as  before  aod 
again  weighed,  the  increase  being  tlie  weight  of 
the  precipitate.  Tared  filters  can,  however,  be 
generally  replaced  by  Ckx>ch  crucibles,  So^et 
tubes,  &c  The  majority  of  the  precipitates 
usually  met  with  can,  moreover,  be  dried  by 
heating  them  in  a  crucible  over  a  lamp.  In 
most  cases  it  is  not  necessary  that  the  precipi- 
tates should  previously  be  dried.  The  greater 
part  of  the  water  is  removed  by  draining  in  the 
tunnel  bv  means  of  the  pump  or  by  placing  the 
filter  and  its  contents  on  a  porous  tile  or  on  a 
oad  of  filter  pap^.  The  filter  is  then  mtro- 
duced  into  a  crucible,  heated  cautiously  until 
quite  drv  and  then  heated  more  strongly  until 
the  weight  is  constant. 

When  the  precipitate  is  not  easily  reducible 
it  is  not  necessary  to  remove  the  paper  before 
ignition.  The  wet  paper  enclosing  the  precipi- 
tate is  placed  in  a  platinum  crucible,  and  the 
lattetr  heated  with  a  full  flame;  the  water 
present  assumes  the  spheroidal  state  and  the 
paper  smoulders  away  without  spurting.  If 
any  slight  reduction  takes  place,  for  example, 
with  barium  sulphate,  it  is  easily  remedied  by 
addins  a  few  drops  of  dilute  sulphuric  acid  and 
asain  heating.  ]!ii  the  case  of  magnesium  pyro- 
phosphate strong  nitric  acid  serves  a  similar 
purpose.  If,  however,  the  precipitate  is  readily 
reduced  in  contact  with  organic  matter,  it  must 
be  removed  from  the  paper  as  completely  as 
possible  bv  gentle  friction,  and  transferred  to 
the  cruel  bio,  which  should  stand  on  a  sheet  of 
glazed  paper.  A  carefully  trimmed  feather  or 
a  camel  s-hair  brush  is  useful  to  transfer  scattered 


particles  from  the  paper  to  the  crucible.  The 
filter  paper  is  then  folded  with  the  portion  to 
which  the  precipitate  had  adherod  inside, 
wrapped  in  platinum  wire  which  forms  a  sort 
of  cage,  and  set  on  fire.  Whilst  burning  it  is 
held  over  the  crucible,  and  taken  eomplddy 
buTTU  out,  the  ash  ia  heated  with  the  tip  of  a 
Bunsen  flame  for  a  few  minutes  and  then  shaken 
into  the  crucible. 

Precipitates  which  contain  compounds  of 
silver,  lead,  sine,  tin*  and  other  easily  reducible 
metalB,  should  be  heated  in  porcelain  crucibles, 
since  platinum  vessels  are  liaole  to  be  attacked. 
Cue  snould  also  be  taken  that  platinum  vesselB 
are  not  heated  with  smoky  or  '  roaring '  flames, 
and  do  not  come  in  contact  with  brass  crucible 
tongs  or  easily  fusible  metals  whilst  hot.  After 
some  time  the  surface  of  the  metal  may  become 
duD,  owing  to  th$  partial  disageregaiion  of  the 
platinum,  but  this  defect  can  oe  remedied  by 
polishing  the  metal  with  sea-sand  or  a  burnisher. 

Heaitng  trnpUancea. — ^The  ordinair  bunsen 
burner  serves  tot  most  operations,  but  the  arjpod 
bunsens  introduced  by  fietcher  are  more  efficient^ 
and  the  radial  slit  burner  of  the  same  inventor 
is  perhaps  the  most  e£Bdent  «ks-bumer  for  heat- 
ing purposes  that  has  yet  been  made.  Qlass 
vessels  are  more  safely  heated  on  a  sheet  of  wire 
gauze  or  on  a  layer  of  sand  in  a  metal  tray.  A 
most  useful  piece  of  apparatus  in  a  tecnnioal 
laboratory  is  a  laryce  iron  plate  supported  on  iron 
le^,  and  heated  by  a  burner  underneath  the 
middle.  Veeseb  placed  on  the  plate  near  its 
edges  are  subjected  to  a  very  gentle  heat»  but 
may  be  raised  to  a  much  higher  temperature  by 
being  moved  nearer  to  the  middle. 

A  water-bath  provided  with  a  constant  feed- 
ing arrangement  is  the  most  useful  way  of  heat- 
ing vessels  at  100*.  If  higher  temperatures  are 
needed,  a  saturated  solution  of  calcium  chloride^ 
melted  paraffin,  or  oil  may  be  used,  liaumen^ 
(Compt.  rend.  1883, 07, 45,  and  216)  has  proposed 
to  use  fused  mixtures  of  alkaline  nitrates  for 
temperatures  between  140*  and  260*.  Brauner 
(Chem.  Soo.  Trans.  1885,  47,  887)  has  described 
a  simple  arrangementTor  heating  substances  in 
sulphur  vapour. 

Beagents. — ^The  ordinary  acids  and  ammonia 
are  required  in  a  dilute  as  well  as  in  a  oonoen- 
trated  form.  Whenever  possible  the  reagents 
should  be  made  in  solutions  the  strengths  of 
which  are  multiples  or  submultiples  of  normal 
solutions.  A  convenient  strength  for  the  dilute 
mineral  acids  is  twice  normal,  and  the  alkaliro^ 
solutions  should  be  of  equivalent  strength. 

QUALITATIVB  AVALTSIS. 

The  detection  of  the  oonstituents  of  a 
mixture  or  chemical  substance  is  based  on  the 
fact  that  almost  every  metallic  or  acidic  radical 
will  under  suitable  conditions  give  rise  to  a 
reaction  which,  under  these  conditions,  is 
churacteristic  and  thus  enables  one  to  distinguish 
this  radical  from  all  others.  These  tests  may  be 
applied  directly  to  the  solid  substance,  usually 
at  high  temperatures,  when  they  are  Imown  as 
dry  reactions  ;  or  they  may  be  employed  in  solu- 
tion, in  which  case  thev  are  described  as  wet 
reactions.  The  wet  and  dry  reactions  of  metallio 
and  acidic  radicals  are  generally,  but  by  no 
means  invariably,  independent  of  the  acidic  and 


ANALYSTS. 


227 


metallic  radicals  with  which  they  are  respec- 
tively  oombined. 

Examination  In  the  Dry  Way. 
The  indications  obtained  from  tho  dry  re- 
actions of  a  substance  frequently  a£ford  very 
suggestive  dnes  to  its  composition,  but  as  these 
tests  rarely,  if  ever,  indicate  the  relative  pro- 
portions in  ^idiich  the  constituents  exist  in  the 
mixture  under  examination,  they  must  be  re- 
garded as  being  preliminary  to  the  more  syste- 
matic examination  of  the  substance  in  solution. 
Moreover,  negative  results  obtained  from  dry 
tests  must  not  be  accepted  as  final  evidence. 

In  all  cases,  however,  a  preliminary  examina- 
tion of  the  substance  should  be  made  in  the  dry 
way,  and  if  the  substance  is  in  solution  a  portion 
^oiUd  be  evaporated  to  dryness.  The  reactions 
of  several  substances  in  the  dry  way  are  inter- 
fered with  and  rendered  inconclusive  by  the 
presence  of  certain  other  substances ;  but  never- 
theless an  examination  of  this  kind  often  gives 
much  information  in  a  short  time. 

The  most  convenient  source  of  heat  for  this 
purpose  is  the  ordinary  bunsen  burner.  This 
consists  of  a  metal  tube  at  the  base  of  which 
ooal  gas  enters  by  means  of  a  jet,  the  lower  part 
of  the  tube  being  pierced  with  holes  through 
which  air  is  drawn  and  mixed  with  the  ooal  gas. 
The  mixture  of  1  volume  of  coal  gas  with  about 
2)  volumes  of  air,  which  is  thus  pSroduced,  bums 
at  tiie  top  of  the  tube  with  a  non-luminous  flame. 
When  tne  supply  of  gas  is  turned  low,  it  is 
necessary  also  to  reduce  the  air  supply  by 
partially  closing  the  inlet  holes  by  means  of  a 
regidator.  The  upper  part  of  the  burner  is 
generally  fitted  with  a  sunport  carrying  a  cone 
to  protect  the  flame  from  draughts. 

The  flame  consists  essentully  of  an  innett- 
dark  n>ne  containing  unbumt  gas  mixed  with 
air,  and  an  outer  zone  or  flame  mantle  in  which 

combustion  becomes  com- 
plete. If  the  air  holes  are 
partially  closed,  a  luminous 
cone  appears  at  the  top  of 
the  inner  zone.  Bunsen  has 
shown,  however,  that  several 
distinct  zones  exist,  each  of 
which  can  be  utilised  for  pro- 
ducing particular  reactions. 
The  most  useful  of  these  are 
a,  a  comparatively  cold  zone 
at  the  base  of  the  name,  which 
serves  for  the  volatilisation 
of  salts  in  order  to  obtain 
flame  colourations;  the  lower 
reducing  fame  Z  about  one 
quarter  of  the  way  up  and 
close  to  the  edge  of  the  dark 
zone ;  9,  the  upper  and  more 
pow^ful  reducing  fiame  at 
the  top  of  the  dark  zone, 
obtained  by  closing  the  air 
holes  until  the  tip  of  the 
inner  zone  just  becomes  lu- 
minous; fifthe  zone  of  fusion 
at  hi^est  temperature,  at 
about  one-third  the  height  of 
the  flame  and  half-way  be- 
tween the  inner  zone  and  the  flame  mantle ; 
7,  the  loufer  and  hotter  oxidising  fame  at  the 
edge  just  below  the  zone  of  fusion ;  and  «,  the 


Fio.  5. 


upper  oxidising  fame   at  the  extreme  tip  of 
the  flame. 

Instead  of  the  bunsen  burner,  the  flame  ob- 
tained by  means  of  a  blowpip^may  be  used ;  a 
mouth  blowpipe  consists  of  a  metal  tube  pro- 
vided at  one  end  with  a  mouthpiece,  the  other  end 
fitting  into  a  small  metal  box  which  serves  to 
condense  and  retain  the  moisture  of  the  breath. 
From  the  side  of  this  box  a  second  shorter 
and  narrower  tube  projects  at  right  angles  to 
the  first,  and  is  provided  with  a  nonle  or  jet  of 
brass  or,  better,  of  platinum.  For  general  work 
the  diameter  of  the  bore  of  the  jet  should  be 


1 


C£ 


Fig.  a 

0-4  mm.  In  Black's  blowpipe  the  larger  tube  is 
conical,  the  lower  and  wioer  end  serving  the 
same  purpose  as  the  box  in  the  form  just  de- 
scribed. The  art  of  keeping  up  a  continuous 
blast  of  air  through  the  olowpipe  can  only  be 
acquired  by  practice.  The  necessary  pressure  is 
produced  by  distending  the  cheeks,  breathing 
oeing  carried  on  through  the  nostrils,  whilst 
communication  between  the  nostrils  and  the 
mouth  is  cut  off  by  the  pressure  of  the  tongue 
acainst  the  palate.  A  convenient  form  of  hand- 
blower  for  blowpipe  work  has  been  devised  by 
Fletcher. 

A  good  flame  for  blowpipe  work  is  obtained 
by  dropping  into  the  tube  of  an  ordinary  bunsen 
burner  a  brass  tube,  the  lower  end  of  which 
descends  to  the  bottom  of  the  burner  and  cuts 
off  the  supply  of  air,  whilst  the  upper  end  ia 
flattened  and  cut  off  obliquely.  The  flame 
should  be  much  smaller  than  when  the  burner 
is  used  in  the  ordinary  way.  Goal  gas  usufldly 
contains  more  or  less  sulphur,  and  consequently 
cannot  be  used  when  testing  for  this  element. 

A  thick  stearin  candle  answers  well;  but 
nothing  is  better  than  a  lamp  consisting  of  a  low 
and  rather  wide  cylindrical  metal  vessel,  open 
at  the  top,  with  a  somewhat  broad  and  flat  wick- 
holder  attached  to  the  side.  The  fuel  used  is 
solid  parafBji,  which  is  kept  in  a  mdted  condi- 
tion by  the  heat  of  the  blowpipe  flame,  the  wick 
being  so  arranged  that  the  flame  passes  over  the 
top  of  the  para£Bn.  A  metal  cover  protects  the 
lamp  from  dust  when  not  in  use. 

The  nozzle  of  the  blowpipe  is  introduced  a 
short  distance  into  the  lamp  flame  at  a  short 
distance  above  the  wick,  and  when  the  blast  is 
produced  the  flame  is  deflected  horizontally, 
becomes  long  and  narrow,  and  is  seen  to  consist 
of  two  parts,  vis.  an  outer  or  oxidising  flame,  at 
the  tip  of  which  there  is  an  excess  of  oxygen 


heated  to  a  high  temperature,  and  an  inner  or 
reducing  flame,  which  contains  carbonic  oxide 
and  hydrocarbons  heated  to  a  high  temperature. 
If  the  blowpipe  is  held  just  at  the  edge  of  the 
flame  and  a  moderate  blast  is  used,  a  broader 


228 


ANALYSIS. 


reducing  flame  can  be  obtained,  which  has  a 
luminouB  tip  oontainiiut  solid  partides  of  carbon. 

The  following  apj^ianoee  are  required :  a 
■mall  pair  of  f oitejie  with  platinnm  points ;  short 
pieces  of  thin  platinum  wire ;  charcoal  from  some 
fine-grained  compact  wood ;  glass  tubes  about 
3  mm.  internal  aiameter,  and  60-80  mm.  Jong, 
closed  at  one  end ;  aud  glass  tubes  of  similar 
diameter  100-120  mm.  lon^,  open  at  both  ends 
and  bent  slightly  in  the  middle.  The  reagents 
used  are  borax,  microcosmic  salt  (NH4NaHP04, 
4H2O),  pot-assium  cyanide,  sodium  carbonate, 
potassium  nitrate,  cobalt  nitrate  solution,  aud 
potassium  hydrogen  sulphate. 

Hie  dry  tests  are  conveniently  performed  in 
the  follo^in|[  order : — 

(1)  II eating  in  a  dry  closed  tube. — ^To  avoid 
Boilms  the  sides  of  the  tube,  the  substance 
should  bo  introduced  by  means  of  a  roll  of  stiff 
paper.    The  following  changes  may  be  observed : 

(a)  Carbonisation  with  or  without  evolution 
of  empyreumatic  vapours  «  organic  eompaunds. 

(b)  Condensation  of  moisture  on  cold  parts 
of  tube  ;  neutral  reaction  >=  hydrated  salts  and 
hydroxides ;  acid  reaction  «  acids  and  add  salts ; 
alkaline  reaction  b  ammonium  salts, 

(c)  Fusion  without  change  of  colour  =  alka- 
line salts,  hydrated  salts. 

(d)  Fusion  with  chance  of  colour  »  yeUow 
hot,  dark  yellow  cold  «  oismuih  oxide ;  yellow 
hot,  red  cold  =  lead  oxide.  The  chromates  of 
lead  and  the  alkali  metals  fuse  and  darken  on 
heating. 

(e)  No  fusion,  but  change  of  colour :  dark 
yellow  hot,  pale  yellow  com  «  stannic  oxide ; 
yellow  hot,  white  cold  =  zinc  oxide  ;  black  hot, 
reddish -brown  cold  <=/emc  oacide;  black  hot, 
bright  red  cold  b  mercuric  oxide ;  brown  darken- 
ing on  heiiting  »  cadmium  oxide, 

(/)  Gas  evolved:  OTygen^oondes,  peroxides, 
chlorates^  bromates,p€rchlorates,  iodates,  periodates, 
ptrsulphaies,  and  nitrates ;  carbon  dioxide  s 
carbonates,  bicarbonates,  oxalates;  carbon  mon- 
oxide (blue  flame)  ss formates,  oxidates;  sulphur 
dioxide  =  acid  silphiUs,  stdphates  of  heavy 
metals  (together  with  sulphur  trioxide) ;  cyanogen 
B  cyanides  of  heavy  metals ;  ammonia  »  am- 
monium salts  ;  phosphine  a  phosphites,  hypo- 
phosphites  ;  orange-brown  vapours  '^  nitrcies, 
nitrites,  bromides  ;  violet  vapours  ■■  iodides ; 
colourless  fuming  gas  =  hydraied  chlorides, 

Uj)  Sublimate :  white  infusible  «  arsenious 
oxide  (octahedra),  antimonious  oxide  (needles), 
selenium  dioxide,  ammonium  chloride,  am- 
monium sulphite  (from  ammonium  sulphate); 
white  fusible « mercuric  chloride,  tellurium 
dioxide,  organic  acids,  molybdenum  trioxide  (at 
very  high  temperatures) ;  coloured,  black,  or 
reddish  black  »  selenium,  mercuric  sulphide  ; 
yellow  hot,  red  cold  =  mercuric  iodide ;  reddish 
yellow  B  arsenious  sulphide  ;  yellow  s  sulphur 
and  sulphides ;  bleu)k  metallic  mirror  =  arsenic  ; 
grey  metallic  globules  ■■  mercury.  These  metal- 
lic sublimates  are  often  obtained  nore  readily  by 
beating  the  material  with  potassium  cyanide. 

Phosphorus  compounds  are  detected  by 
heating  m  a  closed  tube  with  magnesium  ribbon 
and  dropping  the  hot  tube  into  water,  when  in- 
flammable phosphine  is  evolved. 

(2)  Heating  in  open  tube, — ^The  tube  bcinff 
inclined y  to  promote  a  current  of  air  throush 
it,  the   changes  observed   are  similar  to  the 


reactions  in  the  dosed  tube,  but  sulphides 
bum  evolving  sulphur  dioxide;  anenio  is 
oxidised  to  arsenious  oxide,  and  selenium  and 
its  compounds  evolve  a  pungent  odour  of  horse- 
radidi  (dioxide),  and  give  a  grey  or  reddish 
sublimate. 

(3)  Heating  on  platinum  wire. — Flame  coloura- 
tions.— ^The  wire  bein^  cleaned  by  repeated  dip- 
ping in  hydrochloric  acid  and  heating  tul  it  impaits 
no  colour  to  the  flame,  a  small  quantity  of  the 
substance  supported  on  the  end  of  the  wire  is 
introduced  into  zone  a  of  the  bunsen  flame.  As 
a  colouration  is  produced  only  if  volatile  com- 
pounds of  the  metsls  are  present,  the  substance 
should  be  moistened  with  hydrochloric  acid  to 
produce  the  volatile  chlorides.  This  result  may 
also  be  attained  by  mixing  the  substance  on  an 
asbestos  thread  with  moist  silver  chloride,  a 
compound  which,  while  imparting  no  colour  to 
the  name,  slowly  yields  chlorine,  converting  other 
motals  into  omorides.  The  wire  should  be 
slowly  moved  into  the  hottest  part  of  the  blow- 

Sipe  or  bunsen  flame,  bo  that  the  ooburaUons 
ue  to  less  volatile  constituents  may  be  snc- 
ceesively  developed. 

Octaurations :  yellow  =  sodium ;  oranse  red 
B  calcium  ;  crimson  a  strontium^  limium  ; 
lavender  a  potassium,  rubidium,  ccssium ;  apple 
green  «=  barium ;  bright  green  »  thallium, 
copper,  boric  acid ;  pale  blue  b  lead,  antimony ; 
deep  blue  becoming  green  »*  copper  kalides ; 
deep  blue  »  selenium. 

The  pocket  spectroscope  (direct  vision)  is  a 
useful  aid  in  examining  flame  colourations, 
particularly  in  the  case  of  strontium  and  calcium, 
which  exhibit  respectively  a  characteristic  bine 
aud  a  yellowish-green  line. 

(4)  Heating  on  charcoal, — ^The  substance 
mixed  with  three  times  its  weight  of  dry  sodium 
carbonate  or  of  a  mixture  of  2  parts  sodium  car- 
bonate and  1  part  potassium  cyanide,  is  placed 
in  a  small  shallow  hole  scooped  out  in  charcoal* 
and  heated  in  a  reducing  flame.  The  metallic 
bead  obtained  is  examined  as  to  oolour,  malle- 
ability, solubility,  Ac  Many  metals  yield  fllms 
of  oxide,  which  coat  the  charcoal  at  a  greater  or 
less  distance  from  the  flame,  and  the  colour  and 
appearance  of  which  are  more  or  less  ohaiaoter- 
istic  These  and  similar  fllms  are  best  seen 
when  the  charcoal  is  supported  on  an  alnmininm 
plate  (Ross).  A  piece  of  sheet  aluminium  12  om. 
by  6  cm.  is  bent  m  right  angles  at  a  distance  of 
2  cm.  from  one  end,  thus  forming  a  ledse  on 
which  a  small  flat  piece  of  charcoal  is  putcod, 
the  plate  being  hda  so  that  the  surface  rises 
vertically  behind  the  ledge.  Vols  tile  oxides,  Ac., 
condense  on  the  metallic  surface  {v,  Hutohings, 
Chem.  News,  1877,  36,  208,  217). 

The  reduction  may  also  be  effected  by  adding 
a  fragment  of  sodium  to  the  substance  supported 
on  charcoal  (Parsons,  J.  Amer.  Chem.  8o«.  1901, 
23,  169). 

In  order  to  obtain  reduced  metals  with  the 
bunsen  flame,  a  match-stick  is  smeared  with 
ordinary  sodium  carbonate  (washing  soda)  which 
has  been  melted  by  holding  it  in  the  flame,  and 
the  wood  thus  prepared  is  csrbonised  by  heating 
it  in  the  flame.  A  small  quantity  of  the  sul^ 
stance  is  mixed  in  the  patm  of  the  luuid  with  a 
small  quantity  of  the  fused  washins  soda,  and 
the  mixture  is  carefully  placed  on  uie  charcoal 
splint,  which  is  then  heated  in  the  lower  or  upper 


ANALYSIS. 


229 


redacing  flame.  When  leducting  is  cooiplete, 
the  match  is  allowed  to  cool  inside  the  dark  zone, 
and  is  then  withdrawn,  crushed  in  a  mortar,  and 
the  lighter  particles  of  charcoal  removed  by 
levi^ation  with  water,  the  heavy  metallic 
particles  being  left. 

By  means  of  the  bonsen  flame  reduced  metals 
and  their  oxides  can  be  obtained  in  the  form  of 
Alms  on  a  porcelain  stirface.  The  substance  is 
supported  on  a  long  slender  piece  of  asbestos, 
and  fauMted  in  the  tip  of  a  small  oxidising  or 
reducing  flame,  a  small  evaporating  dish  con- 
taining cold  water  being  held  momentarily  juRt 
above  tJie  asbestos  {v.  Bunsen's  Flammen- 
rcactionen,  Heidelberg,  1880). 

Incrustations  on  charcoal:  white,  ver^ 
volatile  =  arsenic  ;  white,  less'  volatile  &»  anti- 
mony ;  orange-yellow  hot,  pale  yellow  cold  ^ 
bismtUh;  pale  yellow  hot,  deep  yellow  cold, 
white  edge  »  lead ;  yellow  hot,  white  cold  = 
zinCf  mJubdenum ;  roddiah-brown  or  orange- 
ydlow  cold  a*  eadmittm, 

MetaUic  beads  or  residues  on  charcoal: 
white  malleable  =  sUver,  tiny  lead ;  red  malle- 
able s>  copper ;  grey  brittle  a  antimony,  his- 
mtUh :  grey  powder,  magnetic  =  iron,  cobalt, 
nickel ;  non- magnetic  »■  moli^fdenum, 

(5)  CobaU  nUrate  reactions, — Certain  in- 
fusible substances,  when  moistened  with  cobalt 
nitrate  solution  and  strongly  heated,  acquire 
characteristic  colours.  These  reactions  are 
frequently,  but  not  necessarily,  carried  out  on 
a  charcoal  support : — blue  mfusible  mass  » 
aluminium ;  blue  fusible  =*  certain  phosphates, 
nlicates,  borates ;  green  ^  zinc,  titanium,  tin ; 
pink  a  magnesium. 

(6)  Heating  with  borax  or  microcosmic  salt, — 
A  small  loop  is  made  at  the  end  of  a  platinum 
wire,  to  which  some  borax  or  microcosmic  salt  is 
made  to  adhere,  and  heated  in  the  flame  until 
fused.  The  bead  when  cold  must  be  quite  trans- 
parent and  colourless,  otherwise  it  must  be  re- 
melted,  shaken  off,  and  a  fresh  bead  made.  A 
smaU  quantity  of  the  substance  is  taken  on  the 
bead  and  heated  first  in  the  oxidising  flame  (O.F.) 
and  then,  after  it  has  been  examined,  in  the 
inner  or  reducuis  flame  (LF.).  The  colour  of 
the  bead  should  oe  observed  both  hot  and  cold. 
If  too  much  substance  is  taken,  the  bead  becomes 
opaque,  and  the  colour  cannot  be  distin^piishcd. 

These  so-called  borax  and  microcosmic  beads 
owe  their  colour  respectively  to  the  formation 
of  certain  borates  and  phosj^hates  of  the  heavy 
metals.  Borax  glass  consists  of  anhydrous 
Na^B^OT,  and  ^en  heated  with  a  inetallic 
oxide  or  salt  the  excess  of  boric  oxide  present 
unites  with  the  metallic  oxide,  forming  the 
corresponding  borate: 

Na,B«07+GoO  =  NajB.O.+CoBjOi  (blue). 

Microcosmic  salt  on  ignition  yields  the 
readily  fusible  sodium  metaphosphate,  and  this 
salt  combines  with  metallic  oxides  to  form 
double  orthophosphates : 

NaPO,-f  CuO  =  CuNaP04  (green). 

When  a  silicate  is  introduced  into  the  molten 
metaphosphate,  the  latter  withdraws  the  basic 
oxide  from  the  former,  setting  free  silica,  which 
remains  undissolved  (*  silica  skeleton  ') : 

CaSiOj+NaPO,  =  CaNaPOi+SiO,. 


Borax  beads,^' 
Inner  flame 


Outer  flame 


MeUl 


Hot  Ck>ld         Hot 

Green  Bottle-green  Yellow 

Oreen  Green           Yellow 

Green  Bottle-green  Yellow 


Cokrarieii  Colourlete 

Blue         Blue  Blue 

Grey  *     Grey  Violet 

Brownish  Emerald-      Yellow 

green 
Colourless  Brown  Green 

Colourless  Coloarless 


Cold 
Paler        Iron 
Green       Chromium 
Pale         Uranium 
,  yellow 
Amethyst  Xmetliyst  ManganeMt 


Brown      Brown 
Brownish-violet 
Yellow  to  brown 


Orange- 
red 

Yellow 
Yellow 
Yellow 


Blue 
Beddish- 

brown 
Greenish- 
_yellow 
^ulsh- 

sreen 
C«oailes8 


CobaU 
Nickoi 

Vanadium 

Coppsr 

Cmium 


Colourless  Motybdtnum 
Colourless  Titanium 
Colourless  Tungstsn 

Microcosmic  beads, — ^The  colours  produced 
are  similar  to  those  in  the  borax  bead,  but  the 
reducing  effects  are  less  pronounced.  In  the  I.F. 
molybdenum  compounds  give  a  green  colour, 
and  those  of  tun^ten  a  greenish-blue  tint. 
Chlorides  and  bromides  evolve  a  blue  and  green 
flame  when  heated  with  a  microcosmic  oead 
saturated  with  copper  oxide,  and  iodides  give  a 
green  flame. 

(7)  Other  special  dry  tests, — (a)  Heating  on 
charcoal  with  potassium  (or  cuprous)  iodide  and 
sulphur :  crimson  incrustation  «  bismuth ;  lemon 
yellow  incrustation  a  Uad ;  greenish-blue  fume«f 
Bs  merciiry. 

(&)  Renting  on  charcoal  with  (i.)  fusion 
mixture  (Na^CO^KsCO,)  alone  and  moistening 
with  dilute  acid,  hydrogen  sulphide  evolved  b 
sulphur  compounds;  (ii.)  fusion  mixture  and 
sulphur,  soluble  mass  giving  coloured  precipi- 
tate with  dilute  acid,  yellow  b  tin ;  orange  a 
antimony.  The  fused  insoluble  oxides  SnO, 
and  SbjOt  can  be  thus  characterised. 

(c)  Heating  with  fusion  mixture  and  potan- 
sium  nitrate :  soluble  j^reen  mass  »  manganese ; 
yellow  mass  ■»  ehrxmixum, 

(d)  Heating  in  closed  tube  with  potassium 
hydrvwen  sulphate.  Gas  evolved :  carbon  dioxide 
»  carbonates,  oxalates ;  accompanied  by  charring 
of  the  residue  «■  tartrates,  citrates,  &o. ;  carbon 
monoxide  (blue  A&me)^  formates,  oxalates; 
sulphur  dioxide  ■>  sulphites,  thiosulpJiates ;  hydro- 
gen sulphide  b  sulphides  (not  all) ;  hydrogen 
chloride  (fuming  in  air)  a  chlorides  (not  All) ; 
hydrogen  fluonde  (etching  glass)  s^ftuorides  ; 
bromine  and  hydrogen  bromide  a  bromides ; 
iodmet^iodides ;  nitrous  fumes  a  nitrites,  nitrates, 

EzaminAtlon  In  the  Wet  Way. 

The  preparation  of  the  solution  requires  some 
attention.  A  metallio  substance  is  treated  at 
once  with  moderately  strong  nitric  acid.  Tin 
and  antimony  form  oxides  which  to  a  great 
extent  remain  undissolved  ;  arsenic  is  oxidised 
to  soluble  arsenic  acid ;  other  metals  (with  the 
exception  of  gold  and  the  platinum  metal?,  which 
are  not  attacked)  are  converted  into  nitrates, 
which  dissolve  at  once  or  on  diluting. 

If  the  substance  is  not  a  metal,  it  is  first 
treated  with  hot  water,  and  if  anything  i?  dis- 
solved (which  is  ascertained  by  evaporating  a 
few  drops  on  platinum  foil),  the  substance  is 
boiled  two  or  three  times  with  fresh  quantities  of 
water.  Any  residue  which  may  be  left  is  treated 
with  dilute  hydrochloric  acid,  and  afterwards,  if 
necessary,   with   the  concentrated  acid.    Care 


ANALTSia 


• 

must  be  taken  to  observe  if  any  gai  is  given  off — 
t^»  oarbon  dioxide  feffervesoenoe),  from  carbof^ 
aUs;  Bulphur  dioxide,  from  sulphites  or  thiosvl- 
phates ;  chlorine,  from  peroxides  or  hypO' 
chlorites;  hydrocyanic  acid,  from  cyanides; 
hydrocen  sulphide,  from  sulphides.  Many 
chlorides  are  insoluble  in  the  steong  acid,  and 
hence  the  solution  must  be  diluted  Mfore  filter- 
ing. Silver,  lead,  and  nhivalent  meroury  will 
be  converted  into  insoluble  chlorides. 

Solvent  action  of  the  mineral  acids  (v. 
A.  As  Noyes  and  W.  C  Bray,  J.  Amer.  Ghem. 
Soo.  1007,  29,  137,  481).— In  dealing  with  sub- 
stances insoluble  in  water  the  following  acidic 
solvents  may  bo  used :  hydrochloric,  nitric,  sul- 
phuric, and  hydrofluoric  acids.  Although  it 
IS  impossible  to  give  a  hard-and-fast  rule  as  to 
the  way  in  which  these  agents  should  be  applied, 
the  foUowing  considerations  will  indicate  the 
relative  advantages  of  one  or  other  of  these 
s<Hvents : — 

Hydrochloric  acid, — (1)  Advantages:  (L) 
Solutions  on  this  acid  do  not  yield  a  precipitate 
of  sulphur  on  troatment  with  hydrogen  sulphide  ; 
(iL)  the  solvent  action  of  this  acid  on  the 
following  oxides:  lead  peroxide,  manganese 
dioxide,  and  the  hydrated  oxides  of  tm  and 
antimony,  is  superior  to  that  of  nitric  acid; 
(iiL)  hydrated  dlica  is  readily  precipitated  on 
evaporating  the  hydrochloric  acid  solution. 

(2)  Disadvantages:  (L)  This  acid  is  com- 
paratively useless  lor  alloys ;  (iL)  evaporation 
of  the  hydrochloric  acid  solution  leads  to  the 
volatilisation  of  arsenic,  mercury,  tin  and 
selenium  as  chlorides. 

Nitric  aeid.~-{l)  Advantages :   (L)  The  best. 

?;eneral  solvent  for  the  metals  and  their  alloys ; 
ii.)  oxidises  and  dissolves  insoluble  compounds 
of  arbenio,  merourv,  and  selenium  without 
the  formation  of  volatile  compounds  of  these 
elements;  (iiL)  does  not  cause  the  precipita- 
tion of  ^ver  or  lead ;  (iv.)  oxidises  sulphides 
not  attacked  by  hydrocidoric  and  sulphuric  acids. 
(2)  Disadvantaj;es :  (L)  This  acid  alters  the 
state  of  combination  of  many  elements,  «^.  it 
oxidises  mercurons,  arsenious,  antimonu>us, 
stannous,  and  fenous  salts;  (iL)  its  solution 
deposits  much  sulphur  on  treatment  with 
hydrogen  sulphide ;  (iiL)  the  oxidation  of 
sulphides  by  nitric  acid  in  the  presence  of 
barium,  strontinm*  and  lead  leads  to  the 
precipitation  of  these  metab  as  sulphates ;  (iv.) 
nitric  acid  is  less  efficacious  than  hydrochloric 
acid  in  rendering  hydrated  silica  insoluble. 

The  nitric  acid  solution  of  an  aUoy  when 
evaporated  to  dryness  and  heated  at  120*-130^ 
may  ^ield  the  pertially  dehydrated  hydroxides 
of  silica,  tin,  antimon^r,  titanium,  and  tungsten 
in  an  insoluble  condition.  When  phosphorus 
or  arsenic  is  present  together  with  tin  the  so- 
called  stannic  phosphate  or  arsenate  (phospho- 
stannic  or  azsenoetannic  acid)  may  also  be  found 
in  the  insoluble  residue. 

Stdphuric  acid, — ^The  dilute  acid  ib  of  little 
value  as  a  solvent,  but  the  hot  concentrated 
acid  has  been  found  useful  in  certain  cases. 
(L)  In  bringing  certain  alloys  into  solution,  e^, 
white  metais  (v.  Low,  J.  Amer.  C9iem.  Soc. 
1907,  29,  06);  (iL)  destruction  of  orsanio 
matter ;  evaporation  of  a  concentrated  sulpnuric 
acid  solution  of  the  substance  is  proferable  to 
ignition,  because  the  latter  process  renders  cer- 


tain compounds  insoluble  and  leads  to  the  loss 
by  vofibtuiBation  of  such  elements  as. meroury, 
arsenic,  sdeniam,  &a  Very  stable  oiganio 
substances  (e^.  paraffin  and  cellulose)  oan  be 
destroyed  completely  by  adding  a  little  strong 
nitric  acid  and  heating  till  the  solution  acquires 
a  light  yellow  colour.  When  dilated  con- 
siderably with  water  (20-30  vols.)  this  solution 
may  yield  a  deposit  containing  siliqa  and  certain 
refractory  silicates  and  fluosilicates,  to^^ether 
with  the  sulphates  of  barinm,  strontium,  lead, 
calcium,  ana  chromium  (an  insoluble  sulphate 
formed  during  the  heating),  basic  sulphates  of 
bismuth,  antimony,  and  tin  and  the  ignited 
oaddes  of  the  last  two  metals  with  those  of 
aluminium  and  titanium.  (iiL)  Insoluble  com- 
pound cyanides  aro  decomposed  by  hot  con- 
centrated sulphuric  acid,  out  may  also  be 
attacked  by  aqueous  alkali  hydroxides  yielding 
soluble  allcali  cyanides  and  insoluble  metallic 
hydroxides. 

Hydrofluoric  acid. — ^The  insoluble  reaiduee 
from  the  preceding  acids  may  be  treated  with 
a  40  p.a  solution  of  hydrogen  fluoride,  which  is 
now  obtainable  in  elass  bottles  lined  with 
paraffin  wax.  (1)  Advantages:  (L)  Many 
insoluble  silicates  aro  readily  decomposed,  the 
silicon  bein^  eliminated  completely  as  gaseous 
silicon  fluonde;  (ii.)  the  reducible  metals  and 
their  compounds  may  be  treated  in  platinum 
basins  or  crucibles  providing  that  the  solution 
is  never  evaporated  to  drjrness. 

(2)  Disadvantages :  (l)  GUass  or  silica- waro 
vessels  cannot  be  used  with  hydrofluoric  acid; 
(iL)  owing  to  the  destructive  action  of  hydrogen 
fluoride  on  animal  tissues,  all  operations  with 
solutions  of  this  gas  must  be  conducted  in  an 
efficient  draught  cupboard. 

Aqua  regta  (concentrated  hydrochloric  acid 
S  parts  and  nitric  acid  1  part)  may  be  em- 
ployed in  attacking  substances  not  dissolved 
Dv  hydrochloric  or  nitric  add,  althojgh  it  is 
of  litUe  use  for  colourless  insolubles.  It  readily 
dissolyes  {^old  and  platinum,  but  is  less  efficacious 
in  rendennff  soluble  the  rarer  noble  metals  (e^. 
osmium  ana  iridium). 

Tnatment  of  InsolDbta. 

The  substances  not  dissolved  by  the  fora- 
ging acidic  reagents  aro  generally  regarded  as 
insolubles,  although  they  aro  diyisible  into  two 
classes :  (L)  pseudo-insolubles,  which  are  diasolyed 
by  oertam  specific  solvents ;  (ii.)  true  insolubles, 
which  aro  only  broken  up  into  soluble  com- 
pounds by  the  agency  of  fused  alkali  carbonates. 

Pseudo-insolubles. — SUverchloridetaid  bromide, 
soluble  in  aqueous  ammonia.  (The  three  silver 
halides  may  be  completely  decomposed  by  treat- 
ment with  zinc  and  dilute  sulphuric  acid, 
metallic  silver  and  soluble  sine  haUde  being 
produced.)  Insoluble  fluorides  (those  of  th« 
common  and  rare  earth  metals)  aro  decomposed 
by  heatinff  with  concentrated  sulphuric  acid. 
Lead  sulphate,  soluble  in  ammonium  acetate 
solution ;  oxides  of  antimony,  dissolved  in  hydro- 
chloric and  tartaric  acids.  Ar^ydrous  CMvmic 
sulpJuUe  and  basic  bismuth  sulphate,  converted 
respectively  into  hydroxide  ana  basjo  carbonate 
by  boiling  with  aqueous  sodium  carbonate ;  these 
products  aro  then  dissolved  in  dilute  mineral 
acids. 

True  insolubles. — ^Thesc  substanoes  are  fuied 


ANALYSIS. 


^i 


with  »  mixture  of  sodium  and  potaaaium  car- 
bonates in  equimoleoular  proportions  (so- 
called  fusion  mixture).  In  Uie  absence  of 
reducible  metals  (e^.  silver  or  lead),  insoluble 
sulphates  (barium  and  strontium  sulphates)  and 
silicates  may  be  heated  with  the  fusion  mixture 
in  a  platinum  crucible.  If  any  insoluble  molyb- 
denum sulphide  is  present  (indicated  by  dry 
tests),  a  little  nitre  must  be  added  to  oxidise  this 
sulphide,  and  thus  prevent  its  corrosive  action 
on  the  platinum.  In  the  case  of  an  insoluble 
silicate  the  fused  mass  is  treated  directly  with 
hydrochloric  acid,  when  the  metals  present  pass 
into  solution  as  chlorides,  and  the  aOioa  is  ren- 
dered insoluble  by  evaporatins  down  the  acid 
solution.  In  the  case  of  insoluble  sulphates  the 
fused  mass  is  extracted  witii  water  to  remove 
the  soluble  alkali  sulphate,  and  the  residue 
(BaCO^SrCO,)  is  subsequently  dissolved  in 
dilute  acid. 

Silver  iodide,  bromide,  and  chloride  are 
decomposed  by  'fusion  mixture,*  yielding  the 
soluble  alkali  halide ;  insoluble  lead  compounds 
are  similarly  decomposed.  The  strongly  heated 
oxidesof  aluminium,  chromium,  titanium,  tin,  and 
antimony  rank  as  insolubles ;  they  are  not  readily 
attackeci  by  '  fusion  mixture,*  but  are  rendered 
soluble  by  fusion  with  potassium  hydroxide. 
The  oxides  of  titanium  and  aluminium  may  be 
rendered  soluble  by  fusion  with  potassium 
hydrogen  sulphate;  special  methods  for  treat- 
ing tl^  insoluble  oxides  of  chromium,  tin,  and 
antimony  are  indicated  among  the  dry  tests 
(7,  b  and  c).  The  insoluble  coinpounds  of  the 
easily  reducible  metals  (e^.  Ag,  Pb,  Sn,  Sb,  &c.) 
can  all  be  decomposed  and  reduced  by  fusion 
with  sodium  or  potassium  cyanide. 

When  both  aqueous  and  acid  solutions  have 
been  obtained  from  the  same  substance,  the 
analyst  must  use  his  judgment  as  to  whether 
they  may  be  mixed  or  should  be  analysed 
separately.  The  latter  course  sometimes 
gives  information  as  to  the  distribution  of  the 
aoida  and  bases  in  the  orurinid  substance.  If 
the  first  course  is  adoptee^  it  must  be  borne 
in  mind  that  the  bydrocnloric  acid  solution  may 
preoipitate  lead  and  sUver,  and  possibly  mercury, 
from  an  aqueous  or  nitric  acid  solution. 

Syitematte  Method  of  Examination  In  tht 

Wet  Way. 

The  formation  of  a  precipitate  at  the  proper 
stage  in  the  systematic  separation  is  not  suffi- 
cient proof  of  the  presence  of  a  particular  sub- 
stance ;  some  characteristic  confirmatory  test 
should  always  be  applied.  The  colour  of  the 
solutions  at  different  stages  in  the  operation  is 
a  valuable  indication.  Unnecessary  excess  of 
reagents  should  be  avoided,  but  filtrates  should 
always  be  tested  to  make  sure  that  precipitation 
is  complete.  l£any  teste  succeed  only  wnen  the 
proper  proportion  of  the  reagent  is  added,  and 
it  should  be  a  rule  always  to  add  the  reacents 
very  gradually.  All  precipitates  which  nave 
to  be  tubiected  to  the  action  of  reagents  should 
be  carefully  washed,  but  in  qualitative  analysis 
it  is  not  as  a  rule  desirable  that  all  the  washings 
should  mix  with  the  filtrate. 

The  reaction  of  the  original  solution  towards 
litmus  paper  should  be  noted  and  a  portion 
tested  for  ammonium  compounds  by  heating 


with  sodium  hydroxide  or  by  triturating  in  a 
mortar  with  soda-lime  (dry  sodium  and  calcium 
hydroxides). 

In  systematic  qualitative  analysis  advantage 
is  taken  of  certain  nnnlarUies  existing  between 
the  metallic  radicals  which  enable  these  radicals 
to  be  divided  into  a  limited  number  of  groups, 
the  members  of  which  are  subsequently  either 
separated  or  identified  by  means  of  the  differences 
between  the  properties  of  tJieir  respective  com- 
pounds. 

The  metallic  radicals  are  divided  into  six 
groups,  according  to  their  behaviour  with  the 
following  reagents,  which  must  be  applied  in 
the  order  ^iven.  It  may  be  mentioned  that 
some  chemists  prefer  a  division  into  five  OTOups, 
and  add  the  reagents  of  Qroups  III.  and  Iv.  suc- 
oessiveljr  wUhatU  an  intervening  filtration.  This 
process  is  conveniently  adopted  in  the  presence 
of  the  lees  commonly  occurrmg  metals  (J.  Amer. 
Chem.  Soc.  1908, 30, 481). 

Group  L — Reagent:  hydrochloric  acid  in 
moderate  excess.  Precipitate :  silver,  lead, 
thallium  (thaUous),  and  mercurous  chlorides; 
tungstic  acid. 

If  the  original  solution  is  alkaline,  the  group 
precipitate  may  contain  sulphides  {ejg.  As^S,, 
Sb,S|,  SnS.)  which  had  been  dissolved  in  aqueous 
alkab  sulphide  or  hydroxide.  This  yellow  or 
orange  precipitate  Is  examined  under  Group  II. 
The  group  precipitate  may  also  contain  in- 
soluble silver  salts  (e.a.  A^Br,  Agl)  precipitated 
from  solution  in  alkalme  cyanides  or  thio- 
sulphates;  these  are  dealt  with  as  insolubles. 
The  filtrate  from  the  Group  I.  precipitate  or  the 
solution  itself  in  the  absence  of  a  precipitate, 
must  be  evaporated  nearly  to  dryness  if  nitric 
acid  or  nitrates  are  present,  since  these  com- 

SDunds  lead  to  the  precipitation  of  sulphur  in 
roup  IL 
Gboup  II. — Reagent :  hydrogen  sulphide  in 
acid  solution.  Thioacetic  acid  Ium  been  recom- 
mended as  a  substitute  for  hydrogen  sulphide 
in  qualitative  analysis  (Schiff  and  Tarugi, 
Ber.  1894,  27, 2437).  Precipitate :  the  sulphides 
of  arsenic,  antimony,  tin,  md^denum,  gold, 
^atinum  {the  other  pkUinum  metals),  bismuth, 
lead,  mercury,  copper,  and  cadmium,  together 
with  sdenium  ana  tellurium,  partly  free  and 
partly  as  sulphides.  The  solution  should  be 
dUute  and  not  too  acid,  and  it  should  be  treated 
and  saturated  repeatedly  with  the  group  reagent, 
since  prolonged  treatment  is  required  to  precipi- 
tate molybdenum  and  the  platinum  metals. 

The  nitrate  from  the  foresoing  sulphides  is 
boiled  to  expel  hydrosen  sulphide,  and  any  iron 
present  peroxidised  by  warming  with  nitric 
acid  or  bromine  water.  If  organic  matter  is 
present,  it  is  destroyed  either  by  evapoiation  to 
dryness  or  treatment  with  hot  concentrated  sul- 
phuric acid  (v.  supra).  Silica  or  barium  sulphate 
may  be  precipitated  at  this  stage.  A  portion 
of  the  oxidised  solution  should  now  be  tested 
for  phosphate  with  nitric  acid  and  ammonium 
molybdate. 

Gboup  III. — Reagents :  ammonium  chloride 
and  ammonium  hydroxide.  Precipitate :  (a)  In 
absence  of  phosphates :  hydroxides  of  aluminium, 
iron,  chromium,  glucinum,  titanium,  zirconium, 
tantalum,  colun^ium,  thorium,  cerium  {and 
other  rare  earth  metals),  and  uranium  as  am- 
monium    diuranale.     Some    manganese,    zinc. 


232 


ANALYSIS. 


•  and  alkaline  earth  metals  may  be  copreoipi- 
tatecL  (b)  In  presenoe  of  phosphates:  (he 
phuphates  of  (he  preceding  metale,  together 
with  those  of  Groups  IV.,  V.,  and  magnesium. 

Qbouf  IV. — Reagents :  ammonium  sulphide 
or  hydn^gen  sulphide  and  ammonium  bydroxida 
Precipitate :  sulphides  of  zinc,  manganese,  cobalt^ 
and  niekd.  The  precipitation  is  carried  ont  in 
the  boiling  solution,  and  the  filtrate,  if  brown, 
is  slightly  acidified  with  hydrochloric  acid,  when 
vanadium  and  a  small  portion  of  the  nickel  are 
precipitated  as  sulphides. 

Gbouf  v. — Reagents ;  ammonium  carbonate 
and  ammcHiia.  PrMipitate :  barium,  strontium, 
and  calcium  as  carbonates. 

Qbottp  VL— The  filtrate  from  Group  V. 
contains  magnesium,  sodium,  lithium,  potassium, 
rubidium,  and  ccssium,  i^oh  are  identified  by 
special  tests. 

In  the  absence  of  the  rarer  metallic  radicals, 
the  group  precipitates  are  examined  in  the  fol- 
lowing manner.  Confirmatory  tests  are  given 
under  special  reactions. 

Gbouf  L — ^The  precipitate  is  boiled  with 
water;  the  aqueous  extract  mixed  with  dilute 
sulphuric  acid  gives  a  white  precipitate  (PbS04), 
indicating  lead.  The  insoluble  portion  if  treated 
with  aqueous  ammonia;  a  black  residue 
'  (NH,Hg,a  or  NH.Hga  and  Hg)  indicates 
mercury;  the  ammoniacal  filtrate  acidified 
with  nitric  acid  gives  white  silver  chloride, 
indicating  silver. 

Gboitp  II. — ^The  precipitate  ia  washed  with 
aqueous  hydro^n  sulphide  and  warmed  with 
ydlow  ammonium  sulphide  [(NH4),Sx]>  this 
extraction  being  repeat^. 

(A)  The  filtrate  is  acidified  with  dUute  hydro- 
chloric acid,  the  precipitate  boiled  with  strong 
aqueous  ammonium  carbonate,  and  the  solution 
filtered  i  the  filtrate  acidified  yields  a  yellow 
precipitate  (As^,),  denoting  arsenic  The  residue 
IS  dissolved  in  concentrated  hydrochloric  acid,  the 
solution  boiled,  diluted,  and*  treated  with  strips 
of  platinum  and  pure  zinc ;  a  black  stain  on  the 
platinum  tm  antimony.  The  zinc  is  dissolved 
u  hydrochloric  acid  and  mercuric  chloride  added; 
a  white  precipitate  (Hg,Cl,)  becoming  grey 
(Hg)  «  tin. 

in  the  separation  of  arsenic,  antimony,  and 
tin  by  ammonium  carbonate,  this  solvent 
dissolves  an  appreciable  amount  of  stannic 
sulphide,  which  is  reprecipitated  by  acids  as 
a  white  oxysulphide  (Schmidt,  Ber.  1894,  27, 
2739). 

Boiling  the  mixed  sulphides  with  con- 
centrated hydrochloric  acid  effects  a  separation 
by  dissolving  the  tin  and  antimony  compounds, 
leaving  nearly  the  whole  of  the  arsenious  sulphide 
undissolved  The  mixed  snlphkleB  may  also 
be  dissolved  in  aqueous  sodium  peroxide,  which 
produces  sodium  arsenate,  antimonate,  and 
stannate.  On  boilins  this  solution  with  excess 
of  ammonium  chloriJe,  hydrated  stannic  oxide 
is  precipitated  {v.  J.  Walker,  Chem.  Soc.  Trans. 
1903,  83,  184;  cf.  Caven,  Ghem.  Soc  Proc. 
1910,  26,  170). 

(B)  llie  precipitate  insoluble  in  ammonium 
sulphide  is  boiled  with  nitric  acid  (1  voL  acid 
Bp.gr.  1-20 :  2  vols.  H^O),  the  residue  dissolved 
in  aqua  roffia,  excess  of  acki  expelled,  and  stan- 
nous chloTKle  added ;  a  white  precipitate  (Hj^tCl,) 
indicates  mercury.    The  nitric  acid  solution  is 


evaporated  to  a  small  bulk  with  sulphuric  acid, 
diluted  with  cold  water  and  filtered ;  idiite 
residue  (PbSOi)  indicates  lead.  The  filtrate  is 
rendered  ammoniacal,  blue  colour  ib  copper ; 
white  precipitate  (Bi(HO),) « bismuth,  con« 
firmed  by  dissolving  jn  hydrochloric  acid  and 
diluting  considerably  with  water  (BiOGl).  Tlie 
colour  of  the  filtrate  disohaiged  by  potassium 
cyanide  (excess) ;  the  solution  saturated  with 
hydrogen  sulphide,  a  yellow  precipitate  (GdS)  « 
cadmium  (confirmation.is  essential,  since  a  ycJlow 
cyanogen  derivative  may  be  precipitated  at  this 
stage). 

Gboup  hi.  (phosphates  absent). — ^The  mixed 
hydroxides,  suspended  in  water,  are  warmed  with 
excess  of  sodium  peroxide  and  filtered.  A 
reridue  (Fe,0,'a:H,0,  which  may  contain  some 
MnO ,)  indicates  iron.  The  filtrate  is  divided  into 
two  parts,  (L)  boiled  with  excess  of  ammonium 
chloride,  white  gelatinous  precipitate  (Al(OH)^) 
B  aluminium;  (ii.)  acidified  with  dilute  acetic 
acid  and  lead  acetate  added,  yellow  precipitate 
(PbCr04)  Es  chromium, 

Gbouf  III.  (phosphates  present). — If  the 
original  solution  was  acid,  this  group  precipitate 
may  contain  phosphates  insoluble  in  neutral  or 
alkaline  solutions.  The  sodium  peroxide  separa- 
tion  is  applied  to  one-third  of  ttte  precipitate; 
the  remamder  is  dissolved  in  dilute  nydro- 
chloric  acid,  the  solution  nearly  neutralised 
with  pure  sodium  carbonate,  and  treated 
successivelY  with  ammonium  acetate,  acetic 
acid,  and  terric  chloride  until  no  further  preci- 
pitnte  is  produced  and  the  solution  is  deep  red. 
The  mixture  is  boiled  and  filtered  hot;  tiie 
filtrate  is  then  examined  for  the  metals  of 
Groups  IV.  and  V.,  and  for  magnesium.  The 
precipitate,  which  is  neglected,  contains  ferric 
phosphate  and  basic  fenioacetateu  Ammonium 
formate  may  be  used  instead  of  acetate  in  this 
scparatbn  (Tower,  J.  Amer.  Chem.  Soc.  1910, 
32,  963). 

The  phosphoric  ackl  may  also  be  removed 
by  evaporating  the  filtrate  from  Group  fl.  to 
dryness  with  nitric  acid  and  granulated  tin, 
when  an  insoluble  residue  is  obtained  consisting 
of  metastannic  and  phosphostannic  acids. 

Gboup  IV. — ^The  mixed  sulphides,  washed 
with  hydrogen  sulphide  water,  are  dissolved 
in  aqua  regia,  or  hyarochloric  acid  and  pota^num 
chlorate.  Excess  of  sodium  hydroxide  is  added 
to  the  solution  after  expelling  excess  of  acid ;  the 
precipitate  collected  and  the  filtrate  treated  with 
hydrogen  sulphide;  white  precipitate  (ZnS)^ 
unc  The  precipitated  hydroxides  are  dissolved 
in  hydrochloric  acid,  excess  of  ammonium  acetate 
added,  and  the  solution  saturated  with  sulphide. 
Any  black  precipitate  is  removed  and  the 
fiJtrate  rendered  ammoniacal;  pink  precipitate 
(BlnS)  B  manganese. 

The  black  precipitate  is  tested  in  the  borax 
bead  ;  a  brownish-yellow  colour  indicates  nickel 
presL'nt  and  cobalt  absent.  If  the  bead  is  blue 
{—  cobalt),  the  precipitate  is  dissolved  in  hydro- 
chloric acid,  potassium  chlorate  added,  excess  of 
acid  expelled,  and  the  solution  nearly  neutralised 
with  sodium  carbonate;  excess  of  potassium 
cyanide  is  then  added,  and  the  solution  boiled 
in  an  open  dish.  An  excess  of  sodium  hypo- 
chlorite or  freshly  prepared  sodium  hypo> 
bromite  is  added  to  the  warm  solution ; 
a     black      precipitate    yN'ifii,jrii fi)=  nickel ; 


ANALYSI& 


233 


the  fiHrate  oontains  potaaaiam  cobalticyanide 
(K,Co(CN)«). 

A  q[iuoker  sepantkui  of  the  Groap  IV. 
solphidet  may  be  effected  by  digeeUiiff  them 
with  cold  dilute  bydiochiorio  acid  (1 :  20). 
This  tfeatment  nhould  biin^  the  sme  and 
manganese  into  solution,  learmg  the  sulphides 
of  nickel  and  cobalt  undisaolTed  ;  but  it  is  seno* 
rally  found  that  appreciable  auantities  of  the 
latter  metab  are  present  in  the  nitrate.  Altema- 
tire  methods  of  detecting  and  sepaiatia^  nickel 
and  cobalt  are  nren  under  special  reactions. 

Gboup  V.-~Dia8olve  the  washed  precipitate 
in  dilute  acetic  acid,  add  aqueous  potassium 
chiomato;  yellow  precipitate  (BaCrOj « (a- 
riumi  filtrate  boiled  with  concentrated  aqueous 
ammonium  sulphate;  white  precipitate  (SrS04)a 
sbramHmm :  final  filtrate  treated  with  ammonium 
oxalate;  idiite  precipitate  (OaC.04,zHsO) ■■ 
catdrnm.  Owing  to  their  dose  rejationship,  a 
sharp  aepazation  of  the  three  metals  is  extremely 
difficult.  The  following  altematiTe  process  has 
been  worked  out  (o.  Bray,  J.  Amer.  Chem.  Soc 
1909,  31,  611). 

The  group  precipitate,  which  may  contain 
magnesium,  is  dissolved  in  20  co.  of  30  p.c. 
acetic  acid,  sofaition  neutralised  with  ammonia, 
3  O.CL  of  acetic  acid  added,  diluted  to  40  cc,  10 
ce.  of  20  ]^c.  potassium  chromate  slowly  added, 
solution  boued  for  2  minutes;  yellow  precipitate 
(BaCrO^).  Three  ac.  of  ammonia  added  to 
filtrate,  diluted  to  fiO  cc.,  50  co.  of  alcohol 
(05  p.0.)  added  ;  after  10  minutes  yellow  pre- 
cipitate (SrCr04).  Without  washing  this  pre- 
cipitate, 200  C.C.  of  water  are  added  to  filtnte, 
the  solution  boiled,  and  40  cc.  of  4  p.e.  ammo- 
nium oxalate  added;  after  10  minutes  white 
precipitate  (OaC^O^).  Magneaium  is  precipitated 
m  filtrate  as  a  colourless  crystalline  precipitate 
(Mg(NH4)PO«,6H,0)  by  adding  ammonia  and 
socuum  phosphate. 

Gkovp  VI. — A  portion  of  the  filtrate  from 
V.  examined  for  magnesium  (v.  mpra),  the  re- 
mainder evaporated  to  drvness  and  ignited  to 
expel  ammonium  salts.  The  residue  dissolved 
in  a  small  bulk  of  water,  the  solution  filtered 
if^  neoeraaxy,  examined  by  flame  test  and 
divided  into  two  parts,  (i.)  platinic  chloride 
added;  yellow  crystalline  precipitate  (K,PtCl,) 
BapoiMsium;  (iL)  potassium  pyroantimonate 
added;  colourless  crystalline  precipitate 
(Na,H,8b,07,6H,0) «  sodium. 

Gboup  Sxpajution  nr  thx  Pbxskmgb  of 

THB  RaSBB  MxTALS. 

In  the  presence  of  the  less  commonly  occur- 
ring elements,  the  ordinary  group  separations 
require,  in  certain  instances,  to  be  modified 
very  considerably.  A  systematic  attempt  to 
deu  with  this  problem  has  recently  been  made 
by  A.  A.  Noyea  and  his  collaborators,  to  whose 
orjginal  memoirs  reference  should  be  made  for 
the  exact  working  details  of  the  necessarily 
somewhat  complicated  sejiarations,  an  outline 
of  which  is  given  below  (J.  Amer.  Chem.  Soc 

1907,  29,  137;  1908,  30,  481;  1909,  31, 
611). 

It  will  be  seen  that  the  greater  number  of 
the  rarer  elements  are  precipitated  by  the  re- 
agents of  Groups  II.,  III.,  and  IV.  of  the  fore- 
going analytical  classification ;  but  in  the 
scheme  devised  by  Noyes,  Groups  III.  and  IV. 


are  meiged  into  one,  and  it  is  chiefly  in 
comprehensive  group  that  the  additional  com- 
plications are  to  be  found. 

Group  I. — The  precipitate  may  contain 
tknttaus  Monde  and  iwngsHc  acid,  Ine  former 
is  extracted  by  hot  water,  any  lead  separated 
as  sulphate,  when  the  filtrate  treated  withpotas- 
sium  iodide  gives  a  yellow  precipitate  CfH)  •■ 
thallium.  The  hydrated  tun^^tio  acid,  pre- 
cipitated by  hydrochlorio  add  from  alkali 
tungstates,  remains  in  the  residue,  and  may 
be  separated  from  lead  and  sQver  by  fusion 
with  sodium  carbonate.  The  aqueous  solution 
of  alkali  tungstate  is  boiled  with  dnc  and  hydro- 
chloric acid,  when  the  devdopmsQt  of  a  blue 
colouration  =  tungsten. 

Group  II. — Sdenium,  tdlurium,  molybde- 
num, gold,  pUtinum  and  its  allies,  are  predpitated 
by  hydic^gen  sulphide  in  add  solution.  Ex- 
traction of  the  group  predpitate  with  yellow 
amihonium  sulphide  carries  the  sreater  part 
of  these  dements  into  the  tin  sun-group,  but 
the  separation  is  not  quite  sharp,  for  small  but 
appreciable  quantitieB  of  molybdeoum,  gold 
and  the  platinum  metahi  remain  in  the  insoluble 
sulphides  of  the  copper  sub-group. 

A.  Copper  svb-group. — ^The  precipitate  boiled 
with  dflute  nitric  acid  (1  vol.  of  sp.gr.  1*20 : 2 
vols,  water)  partially  dissdves;  the  solution 
contains  leaid,  copper,  cadmium,  and  bismuth, 
while  the  residue  contains  mercury,  gold, 
platinum,  and  a  trace  of  tin.  The  insohible 
portion  is  oxidised  with  bromine  water,  potas- 
sium chloride  and  hydrochloric  acid  are  added 
and  the  sdution  concentrated ;  a  yellow  crystal- 
line precipitate  (K^dg)  ■«  jMotinum.  The 
excess  of  add  is  expelled  from  the  solution, 
which  is  then  rendered  alkaline  and  boiled  with 
excess  of  oxalic  acid;  a  brownish-black  pre- 
dpitate B  goid, 

B.  Tin  sub-group, — ^The  sulphides  are  re- 
precipitated  by  dilute  add  from  their  solution 
in  ammonium  sulphide,  and  digested  for  10 
minutes  with  nearly  boiling  hydrochloric  acid 
(sp.gr.  1*20);  the  sdution  contains  tin  and 
antimony,  and  the  reddue  arsenic  and  the  rarer 
dements.  The  reddue  is  dissolved  by  strong 
hydrochloric  add  and  potassium  chlorate;  the 
solution  concentrated  to  the  crystallising  point 
yields  a  ycJlow  precipitate  (K,PtGlc)sp2a<miim. 
The  filtrate,  treated  succesdvdy  with  ammonia 
and  magnesia  mixture  fMgGl,,2NH4Cl  with 
NH^-OH),  yields  a  colourless  orydtalline  rare- 
cipitate  (Mg(NH4)AsO«,6H,0)  »  ar«eiiic  The 
filtrate  from  the  aoublo  arsenate  is  evaporated 
to  remove  ammonia,  and  then  boiled  with  oxalic 
acid,  and  the  brownish-black  predpitate  {gold) 
extracted  with  hydrochloric  acid  to  dissolve 
any  co-precipitated  tellurous  add.  The  filtrate 
from  the  gold  is  concentrated  and  acidified  with 
strong  hydrochloric  acid,  and  after  removing 
any  precipitated  potasdum  chloride,  sodium 
sulphite  (in  slight  excess)  is  added  when  a  red 
precipitate  b  seUnium.  The  filtrate  from  se- 
lenium is  diluted  and  treated  euccessively 
with  potassium  iodide  and  solid  sodium  sulphite 
(excess);  the  double  iodide,  KsTelf,  becomes 
reduced,  and  a  black  precipitate  =  tellurium. 
The  final  filtrate  is  boUed  with  hydrochloric 
add  to  expel  sulphur  dioxide,  and  to  the  cooled 
solution  10  p.c  potassium  thiocyanate  and 
stannous   chloride    (or    a   scrap   of    zinc)   are 


234 


ANALYSIS. 


suooeflaively    added,    vfhen     a    red     oolouia- 
tion    (M0(CN8)4)    soluble    in    ether  =  mo^yb- 

Gboufs  IIL  and  IV.—The  filtrate  from 
Group  U.  18  boQed  to  expel  hydrogen  sulphide, 
treated  with  moderately  strong  ammonia,  the 
colour  of  the  ]|^reoipitate  being  noted,  and  the 
ammoniacal  mixture  heated  nearly  to  boiling 
and  treated  with  ammonium  sulphide,  or  pre- 
ferably, in  the  preeenoe  of  nickel,  with  hydrogen 
sulphido  to  saturation.  In  the  presence  of 
vanadium  the  filtrate  has  a  reddish  colour, 
and  on  adding  hydrochloric  acid  brown  vana- 
dium sulphide  is  precipitated.  The  acid  filtrate 
is  boiled  to  expel  nydrogen  sulphide,  and  txeated 
with  ferric  cduoride  and  ammonia  to  precipitate 
last  traces  of  vanadium.  The  presence  of  this 
metal  in  the  sulphide  and  ferric  hydroxide  pre- 
cipitates is  confirmed  by  dissolving  in  nitric 
acid  (sp.gr.  1*20),  diluting  and  adding  hydrogen 
pecoxiae,  when  an  orange-yellow  colouration  a* 
vanadium. 

The  group  precipitate  is  dissolved  in 
hydrochloric  acid  (sp.gr.  1*12),  adding,  if 
necessary,  some  nitric  acid  or  bromine  water. 
The  solution  is  then  boiled  with  hydrochloric 
acid  to  remove  nitric  acid,  and  treated  in  a 
platinum  dish  with  40  p.c.  hydrofluoric  acid, 
and  evaporated  to  dryness.  An  insoluble 
residue  indicates  the  fluorides  of  the  rare  earth 
metals  (thorium,  cerium,  yttrium,  erbium,  &c.) ; 
the  aqueous  extract,  which  contains  all  the  other 
metals  of  this  analytical  group,  is  evaporated 
successively  with  h^rdrochloric  and  nitric  adds. 
The  insoluble  fluorides  are  decomposed  by  hot 
sulphuric  acid,  and  the  resulting  sulphates  of 
the  rare  earth  metals  subjected  to  special  tests 
for  these  elements. 

The  nitric  acid  solution  of  the  other  metals 
of  the  group  is  treated  successively  with  caustic 
soda  SMution,  dry  sodium  peroxide,  and  aqueous 
sodium  carbonate,  when  a  precipitate  B  and 
a  filtrate  A  are  obtained.  This  treatment 
separates  these  metals  into  two  sub-groups,  and 
the  method  is  valid  even  when  phosphates  are 
present. 

A.  The  aluminium  avb-grouf  (may  contain 
sodium  gluoinate,  zinoate,  iduminato,  vanadate, 
chromate,  and  pemranato).  The  solution  is 
acidified  with  nitric  acid  (sp.fl;r.  1*42)  and  diluted 
considerably,  solid  sodium  hydrogen  carbonate 
added  in  moderate  excess  and  the  mixture  heated 
in  a  stoppered  bottle.  The  precipitate  (contain- 
ing zinc,  glucinum,  and  aluminium)  is  dissolved 
in  hydrochloric  acid,  and  the  solution  rendered 
ammoniacal ;  the  zinc  remains  in  solution, 
while  the  hydroxides  of  glucinum  and  alu- 
minium are  precipitated.  Inese  hydroxides  are 
dissolved  in  strong  hydrochloric  acid,  ether 
(1*0  vols.)  is  added,  and  the  cooled  solution 
saturated  with  hydrogen  chloride,  white  crystal- 
line precipitete  (AlCi„6H,0)  =  aluminium. 
The  ethereal  filtrate  is  evaporated,  treated  with 
ammonia,  any  precipitate  dissolved  in  10  p.c. 
sodium  hydroffen  carbonate^  the  solution 
saturated  with  hydrogen  sulphide;  the  filtrate 
from  any  precipitate  sulphide  is  acidified, 
boiled,  and  rendered  ammoniacal,  when  a  white 
flocculent  precipitate  (Gl(OH).)  s  glucinum. 

The  filtrate  obtained  from  tne  first  treatment 
with  sodium  hydrogen  carbonate  is  acidified 
with    nitric   acid,   and   just   neutralised    Tiith 


caustic  soda;  2  cc.  of  nitric  acicl  (8p.gr.  1*20 
and  20  cc.  of  20  p.o.  lead  nitrate  are  added ; 
yellow  precipitate » cknmium.  The  lead  is 
removed  with  hydrosen  sulphide,  the  excess  of 
gas  boiled  off,  vanadyl  salte  oxidis^  to  vanadates 
with  bromine,  any  excess  of  this  reagent  being 
removed  by  boiling.  The  solution,  after 
neutralisation  with  ammonia,  is  treated  suc- 
cessively, with  5  c.a  of  30  p.c.  acetic  acid,  2 
fkins  of*  ammonium  sulphate  (or  nitrate),  and 
grams  of  sodium  pho^hate;  the  mixture  is 
heated  to  boiling,  when  a  white  precipitete 
(U0a(NH«)P04)  a  urantttm.  The  final  filtrate 
is  rendered  ammoniacal,  saturated  with  hydrogen 
sulphide,  acidified  with  acetic  acid,  and  boiled ; 
dark  precipitete  »  vanadium. 

B.  The  iron-manganese  eub-grvup  (mav  con- 
tain the  hydroxides  and  phosphates  of  iron, 
manganese,  cobalt,  nickel,  zinc  (traces),  titanium, 
and  zirconium,  togiather  with  calcium,  strontium, 
barium,  and  magnesium,  as  carbonates  and 
phosphates).  The  precipiteted  hydroxides,  Ac, 
are  dissolved  in  hydrochloric  acid,  the  solution 
evaporated  down  with  strong  nitric  acid,  and 
treated  with  0*6  gram  of  solid  potassium 
chlorate ;  brown  precipitete  »  manganese.  A 
portion  of  the  filtrate  tested  for  phosphoric  acid, 
when,  if  presnnt,  the  remainder  is  treated  with 
ammonium  hydroxide  till  nearly  alkaline,  and 
boiled  with  ferric  chloride  and  ammonium 
acetete.  The  filtrate  conteins  the  ordinarv 
metals  of  Groups  IIL  and  IV.,  together  with 
maffnesium;  the  precipitete  consists  of  the 
hycuroxides,  phosphates,  and  basic  aoetetes  of 
iron,  zirconium,  titanium,  and  possibly  thallium 
(tervalent).  This  precipitete  is  dissolved  in 
hydrochloric  acid  (sp.£r.  1*12),  and  the  solution 
shaken  with  an  equu  volume  of  ether.  The 
ethereal  extract  contains  ferric  and  thallio 
chlorides;  the  hydrochloric  acid  solution  the 
ziroonium  and  titanium.  The  latter  is  evapo- 
rated down  with  sulphuric  add  until  the  hydrogen 
chloride  is  expellee^  the  residue  taken  up  with 
water  and  treated  with  hydrogen  pnoxide.and 
subsequently  with  sodium  phosphate;  orange- 
yellow  colouration  (TiO|) « fttont«m ;  white 
flocculent  precipitete  (Sb{OEyTO^)  a  nreo- 
nium.  The  final  filtrate  is  reduced  with 
sulphurous  add,  when  a  white  floccuko&t  pre- 
cipitete (Ti(0H)*P04)  confirms  titanium. 

Gboups  V.  and  VL — ^In  the  presence  of 
lithium  it  is  preferable  to  precipitete  magnesium 
in  the  caldum  group.  The  filtrate  £com  Groups 
III.  and  IV.  is  concentrated  to  10  cc.  and  treated 
with  30  cc  of  20  p.c  ammonium  carbonate  and 
30  cc  of  96  p.c  aicohoL  After  30  minutes  the 
precipitetion  is  complete,  ihe  magnesium  being 
present  as  the  double  carbonate  (MgCO,, 
(NH4)^CO„4H,0).  The  treatment  of  the  group 
precipitete  has  already  been  described  under 
Group  V.  {v.  stmra).  The  filtrate  is  evaporated 
to  dryness  and  ignited.  The  residue  is  taken 
up  with  10  cc  of  water,  and  one-third  tested 
for  lithium  by  adding  0-6  cc  of  10  p.c  caustic 
soda  and  2  cc  of  10  p.c  sodium  phom^ate, 
heating  to  boiling  and  adding  1  cc  of  alcohol, 
white  precipitete  (Li,PO.)  =  lithium.  The  fil- 
trate  from  this  phosphate  ia  tested  for  potassium 
bv  adding  acetic  acid  and  sodium  cobaltinitritc 
Ine  remaining  two-thirds  of  the  solution,  con- 
taining the  alkali  metals,  are  tested  for  sodium 
by  potassium  pyroantimonate  after  removing 


ANALT8I8. 


235 


ihm  lithiun  m  flnoiide  by  ammaniap  and  am-  ; 
monram  fluoridei. 

BnmlnattMi  to  A«Ul 

Alihoiif^  H  is  not  poanUe  to  fleparato  the 
acidio  radicals  into  a  limited  nombor  of  groupst 
each  havm^  a  gronp  iMgent»  ^  the  leaotiona 
may  be  divxied  into  (i)  preliminary  teste  made 
on  the  original  acJiiticm  or  aabstanoe ;  and  (ii) 
syatematio  teste  made  on  soiteUy  prepared 
solutions.  The  reactions  may  be  oonyeniently 
carried  out  in  the  foUowing  oraer  : — 

L  PreUmimarjf  Utia  (compare  dry  reaotions). 

1.  The  ominal  sabstance  or  solution  is 
warmed  with  duuto  hydrochloric  or  snlphnrio  add. 
A  gas  is  eyoWedy  carbon  dioxide,  turning  lime 
water  miDcy  SB  car6ofia<e;  sulphur  dioxide  »■  ml- 
p^tte ;  hydnwen  soli^iide,  blackening  lead  acetate 
's^niJp£kfe  (not  all) ;  nitrous  fumes  ^^wUriU ; 
hvdrosen  cyanide,  odour  of  bitter  almonds  « 


&  Hie  original  substance  or  soliition 
wanned  slowbr  with  strong  solution  of  sodium 
dichromato  sightly  acidi&d,  carbon  dioxide 
evolved,  con&ms  canbonaU  in  presence  of 
sulphite. 

3.  Heating  teiih  conceidrtUed  nJphmic  add, — 
The  foregoine  eases  may  be  evolved,  and  in 
additi(m  the  foUowing : — 

(a)  CoUmHess: 

Fuming  acid  gas  etohing  glass  «jIaorMie; 
fuming  acid  gas  not  etching  a  ehhride ;  odour 
of  vinegar  a  oeefote ;  carbon  monoxide,  blue 
f\Ame  ^formaieffenocyanide;  carbon  monoxide 
and  dioxide  OB  orolofe ;  sulphur  dioxide  and 
sulphur  sublimate  =  ihiosuLpnaie. 

^)  Colour. 

Orange  vapour,  bromine  ■>  bromuie ;  violet 
vapour  and  hydro^^  sulphide  «  iodide ;  nitrous 
fumes  s  ntlr&y  ntlrate;  oxides  of  carbcm  and 
sulnhor  with  charring  ^  iartraie,  eUraU^  makUe; 
yeuDW  explosive  chlorine  oxide  =>  cMoraie, 

4.  Heating  wiih  akohol  and  concentrated 
eulphmne  add,  green  flame  a  borate.  Before 
performing  this  test  chlorates  must  be  decom- 
posed by  Igniting  the  original  substance,  other- 
wise an  ei^osion  may  result. 

5.  Heating  toOh  concentrated  evlphuric  add 
and  eand,  a  cdourleBB  gas  (SiF4),  giving  a 
gelatinous  precipitoto  on  moist  rod,  confirms 
fiuoride, 

IL  Systematic  teste. — ^Bef ore  testing  a  solution 
for  acids,  boil  with  excess  of  pure  sodium 
carbonate  to  remove  heavy  metels,  filter,  and 
caiefulW  neutralise  with  nitrio  acid. 

1.  Barium  chloride  in  neuteal  solution  yields : 
(a)  a  white  precipitate,  insoluble  in  hydro- 
cfaJoric  add  =  awjphate,  aiUccfiuoride ;  {0)  a 
white  predpitete,  soluble  in  hydroohlorio  acid 
=s  eufpkite^  carbonate^  phosphate^  oxalate^  borate, 
fluoride^  silicate,  tartrate ;  (7)  a  yellow  precipi- 
tate saeAromofo. 

2.  To  a  portion  of  the  neutral  sdution  add 
catdvm  chloride  in  excess,  allow  to  stand  for 
some  time  with  occasional  shaking,  and  filter. 
A  white  predpitete  (a)  insoluble  in  acetic  acid 
S3  oxalate  {stupJiate  in  strong  solutions) ;  {fi) 
soluble  in  acetic  add  » phosphate^  borate,  and 
other  adds  precipitoted  by  barium  chloride. 

CSaUdum  iarttate  after  washing  is  soluble  in 
potash,  and  is  re-predpitoted  on  diluting  and 
tx>iling. 


The  filtrate  from  the  nredpitate  in  the  coid 
is  boiled  for  some  time  and  filtered  hot ;  a  white 
nedpitete  >■  cArote  (moJoIs  in  strong  solutions). 
Tlie  nltcate  from  this  predpitete  is  allowed  to 
cod  and  then  mixed  with  excess  of  alcohol ;  a 
white  predpitete  ■■  emodnate^  malate, 

3.  0ilwr  atlrafe  in  neutral  sdution  yields : 
(a)  A  precipitote  sduUe  in  nitrio  add. 

(1)  White  =  odROale,  borate,  tartrate^  bet^ 
woate,ko, 

(2)  Yellow  »  phosphate,  arsenite, 

(3)  Brick-red  «  arsenate, 

(4)  Da^-red  <-  ckromate. 

{0)  A  precipitete  insdnble  in  nitrio  add. 

Sduble  in  ammonia :  White  »  chloride  (Ay- 
pochlorite),  cyanide,  thiocffonate ;  yellowish- white 
a  bromide ;  orange-red  a  ferricyanide ;  white 
a  ferrocyanide  (sparingly  soluble). 

Insoluble  in  ammonia  :  Yellow  a  iodide ; 
blade  ■■  MiiEpAuIe. 

4.  J'emccJUori&  in  neutral  sdutionsyidds: 
(a)  A  colouration :  blood-red  »  acetate,  for^ 

mate  {predpitete  on  boiling),  ihiocyanaSe  (no 
predpitete  on  boiling) ;  violet  »  salieylate, 
thiosulphtUe  (fnpptive) ;  bluish-black  «  tannate, 
gaUate ;  greenish-brown  « ferricyanide  (dark- 
blue  precipitete  on  adding  stannous  chloride). 

{$)  A  predpitete :  buff  =  bensoole,  coiioii- 
ate ;  reddish-brown  «  sycdnate ;  white  »  phos* 
nhate ;  black  »■  sulphide ;  bluish-  or  greenish- 
olaok  s  tannate,  goBate, 

Sulphur  adds.  (1)  Detect  «tt2pAa(e  by  barium 
chloride,  and  s%dphide  by  lead  acetete,  Ac. 
Bfake  part  of  the  sdution  slightly  alkaline  with 
potash,  add  sine  sulphate  in  consklerable  ex- 
cess, and  filter.  Test  one  part  of  the  filtrate 
for  ihiosvlfhate  by  means  of  hydrochloric  add  ; 
to  the  other  part  add  acetic  acid  till  faintly 
add,  sodium  nitroprusdde  in  small  quantity, 
and  potassium  ferrocyanide ;  a  pink  precipitete 
indicates  a  sulphite. 

(2)  Separation  of  soluble  sulphates,  sulphites, 
snlphides,  and  thiosulphates  in  neutral  solution. 
Precipitete  sulphide  as  Cd8,  PbS,  or  ZnS  by 
addixig  cadmium  carbonate  or  lead  carbonate 
sludge  or  zinc  chloride  solution.  Add  strontium 
nitrate  and  leave  for  12  hours ;  the  predpitated 
strontium  sulphate  and  svdphite  separated  by 
hydrochloric  add,  the  filtrate  contains  the 
thiosulphate,  decomposed  by  strong  hydro- 
chloric acid,  givinff  sulphur  and  sulphur  dioxide 
(Autenrieth  and  Windans,  Zeitsoh.  anal.  CShem. 
1898,  37,  295). 

Chloride,  bromidfl,  and  Iodide.  (1)  Place  the 
substance  in  a  small  fiask  connected  with  a 
small  bulb  U-tube  conteining  a  little  sterch 
paste  and  placed  in  a  beaker  of  water.  Add 
water  and  ferric  sulphate  solution  to  the  sub- 
stance in  tiie  flask,  and  heat  to  boiling.  If 
iodine  is  present,  the  starch  paste  becomes  blue. 
Remove  the  cork,  boil  with  fresh  additions  of 
ferric  sulphate  till  all  iodine  is  expelled.  Now 
add  a  few  crystals  of  potasdum  perman^* 
nate,  connect  with  a  bulb  tube  oontainmg 
chloroform,  and  again  boiL  If  bromine  is 
present,  the  chloroform  is  coloured  brown.  Boil 
with  addition  of  more  permanganate  until  all 
bromine  is  expelled,  filter  and  test  filtrate  for 
chlorine  (Hart,  Amer.  Chem.  J.  1884,  6,  346). 

(2)  After  iodine  has  been  detected  by  means 
of  nitrogen  oxides  in  sulphuric  add,  evaporate 
part  of  the  solution  to  dryness  with  sodium 


236 


ANALYSIS. 


carbonate,  fuBe  with  ten  times  its  weight  of 
potaasium  dichfomate  tUi  all  iodine  is  expelled, 
place  in  a  small  dry  retort,  and  heat  with  strong 
solphnrio  aoid.  Part  of  the  distillate  is  agitated 
witk  water  and  carbon  disulphide ;  if  bromine 
is  present,  the  latter  becomes  orango-Ted«  The 
remainder  of  the  distillate  is  neutralised  with 
ammonia,  and  tested  for  chromic  acid  by  acidi- 
fying with  acetic  acid  and  adding  lead  acetate. 
The  presence  of  chromic  acid  inmcates  the  pre- 
sence of  chlorine  in  the  original  substance. 

(3)  A  neutral  solution  of  the  three  halidea 
is  treated  with  potassium  iodate  and  dilute 
acetic  acid ;  as  iodine  is  liberated,  more  iodate 
is  added  and  the  solution  boiled  until  all  the 
iodine  is  eliminated.  The  solution  is  mixed 
with  half  its  volume  of  52\r-nitric  aoid,  bromine 
is  evolved  and  the  solution  boiled  till  colourless 
A  little  potassium  iodide  added  to  destroy  the 
iodate  in  excess,  and  the  solution  boiled  till 
colourless,  then  an  equal  volume  of  strong  nitric 
acid  and  a  fewdzope  of  silver  nitrate  are  added, 
when  a  white  precipitate  indicates  a  chloride: 
The  stron£[  nitnc  aoid  holds  in  solution  anv 
trace  of  sdver  iodate.  If  thiooyanio  acid  » 
present,  the  test  for  iodine  must  be  made  in  a 
small  portion  of  the  original  solution,  adding 
sodium  acetate  as  well  as  acetic  aoid  to  depress 
the  dissociation  of  the  latter  (Benedikt  and 
Snell,  J.  Amer.  Chem.  Soa  1903,  25,  800). 

Cihar  acids  must  be  detected  b^  special  teste* 
Iodine,  and  ferrocyanides  and  fetnoyanides  must 
be  removed  before  testing  for  nitrates. 

To  remove  iodine^  ferrocffanic,  ferrtcyaaaic, 
and  iMocyanie  aeids,  add  excess  of  a  mixture  of 
cupric  and  ferrous  sulphates,  and  filter.  To 
remove  excess  of  copper  and  iron  (which  is  not 
always  necessary)  heat  to  boiling,  add  slight 
excess  of  pure  caustic  potash  or  soda,  and  filter. 

To  remooe  bromitie  and  iodine^  acidify  with 
dilute  sulphuric  acid,  and  boil  with  successive 
additions  of  potassium  permanganate  until  the 
liquid  has  a  faint  permanent  piiQi  tinge ;  filter. 

To  remove  hi^pocHlorous  and  nUrous  acids, 
acidify  with  dilute  sulphuric  acid,  and  boiL 
Nitrous  acid  can  also  be  decomposed  by  boiling 
with  a  stronff  solution  of  ammonium  cmoride. 

For  an  altemative  classification  of  the  acidic 
radicals  into  analytical  groups,  compare  T.  MOo- 
bendski  (J.  Russ.  Phys.  Chem.  Soo.  1909,  41, 
1301). 

Sfbcial  Reactions. 

In  the  following  lists  only  the  most  charac- 
teristic and  useful  reactions  have  been  given ; 
negative  reactions,  and  others  not  particularly 
characteristic,  have,  as  a  rule,  been  omitted  {see 
also  Dry  reactions). 

MiTALS. 

The  metals  are  arranged  in  the  order  of  their 
occurrence  in  the  systematic  separation. 

Silver. 

Hydrochloric  acid,  a  white  precipitate  (AgG), 
insoluble  in  hot  water  and  in  nitric  aoid ;  soluble 
in  ammonia  and  rcprecipitated  by  nitric  acid  in 
excess.  PoUissium  chromate,  a  darJ^-red  pre- 
cipitate (AgaCr04) ;  soluble  in  mineral  acids 
and  decompcmed  by  caustic  alkalis.  Potassium 
cyanide,  white  precipitate  (AgCN)  soluble  in 
excess  to  KAgfCM)^. 

Lead. 

Hydrochloric  acid,  a  white  precipitate  (PbCla), 


soluble  in  hot  water,  from  which  it  crystallises 
on  cooling;  insoluble  in  ammonia,  hydrogen 
sulphide,  a  black  precipitate  (PbS),  insoluble  in 
ammonium  sulphide  (m  presence  of  hydrogen 
halides,  intermediate  red  compounds  are  rao- 
duced,  e,g,  PbS,4PbI„  J.  Amer.  C3iem.  Soc. 
1890,  17,  611 ;  1901,  23,  680) ;  soluble  in  nitric 
acid.  Sulphuric  acid,  a  white  precipitate 
(PbS04),  soluble  in  hot  hydrochloric  acid ;  in- 
soluble in  dilute  sulphuric  add ;  soluble  in 
ammonium  acetate  (Noyes  and  Whitcomb, 
J.  Amer.  Chem.  Soc  1905,  27,  747).  Potassium 
ehromaie,  yellow  precipitate  (PbCrOf),  in- 
soluble in  acetic  acid ;  soluble  in  potassium 
hydroxide. 

ThanionL 

Hydrochloric  acid,  white  precipitate  (TlCl), 
only  slightly  soluble  in  hot  water.  Potassium 
iodide,  pale-yeUow  precipitate  (Til),  even  in 
dilute  solutions.  Swphuric  acid,  no  precipitate 
(diff.  from  Pb).  Sodium  cdbaltiniirite  (rives  red 
crystalline  precipitate  (Tl,Co(NOa)c)  (J.  Russ. 
Phys.  Chem.  Soc.  1910,  42,  94). 

TungBtoii. 

Hydrochloric  acid,  a  yellowish-white  pre- 
cipitate {H,W04),  insoluble  in  excess  of  the 
dilute  acid;  soluble  in  the  concentrated  acid 
and  in  tartaric  acid ;  fragments  of  sine  added 
to  this  solution  produce  a  blue  colouralion. 
Stannous  chloride,  a  yellow  precipitate,  which 
becomes  blue  if  mixed  with  nydrochlorio  aoid 
and  heated.  Ammonium  sulphMc,  no  precipitate 
with  sodium  tungstate,  but  on  acidifying,  light- 
brown  precipitate  (WS,),  insoluble  in  hydrochK>rio 
adds,  soluble  in  ammonium  sulphide. 

Meieuy. 

Mercurous  compounds.  Hydrochloric 
acid,  white  precipitate  (Hg,Cl,),  insoluble  in 
hot  water ;  insoluole  in  ammonia,  but  blackened 
(NH,Hg,Q).  Stannous  chloride,  grey  precipi- 
tate (Hg).  Metallic  copper,  becomes  coated  with 
mercury,  which  can  be  sublimed. 

Mercuric  compounds.  Hydrogen  sulphide, 
white  precipitate,  becoming  yoQow,  red,aaa  then 
black  (Hgo) ;  insoluble  in  ammoninm  sulphide ; 
appreciably  soluble  in  alkalisulphideG<  Hg(SNa)|), 
insoluble  in  nitric  acid ;  soluble  in  aqua  ^^i** 
Stannous  chloride,  white  predpitate  (HgiO,), 
becoming  grey  (Hg)  with  excess  of  the  reagent. 
Potassium  iodide,  scarlet  predpitate  (Hglf). 
soluble  in  excess.  Metallic  copper,  as  merourous 
salts.  For  detection  of  minute  traces  of  mercury, 
as  in  toxicological  inquiries  by  electrolytic  and 
spectroscopic  methoois,  see  Browning  (Chem. 
Soc.  Trans.  1917,  111,236). 

Bbmuth. 

Hydrogen  sulphide,  brown  predpitate  (Bi,8,), 
insoluble  in  ammonium  sulphide;  soluble  in 
nitric  add.  Ammonia,  white  predmtate 
(Bi(HO)t),  soluble  in  hydrochloric  acid.  Water 
in  large  excess  (with  previous  addition  of  am- 
monium chloride  if  ohforides  are  absent),  white 
precipitate  (BiOCl),  soluble  in  hydrochloric  add ; 
insolulf)le  in  tartaric  acid.  Reducing  agents 
(sodium  stannite,  hypophosphites,  bydrosul- 
phites,  formaldehyde  in  alkaline  solution)  reduce 
bismuth  compounds  to  elemental  bismuth. 

Copper. 

Hydrogen  sulphide,  black  predpitate  (CvS), 
insoluble  in  ammonium  sulphide  and  in  dilute 
sulphuric  acid ;  soluble  in  nitric  acid  and  in 
potassium  cyanide.    Ammonia,  blue  predpitate. 


ANALYSIS. 


237 


eclahle  in  excess  to  darfc-bhw  solotioD.  Poias- 
mum  femcffumidt^  chofolste  brown  preefaiitate, 
inaolobfe  in  dihifte  acids ;  in  Tny  diliite  aonitioiis 
ooloantiim  onl^;  deoomposed  by  sodium 
bydrOzide,  yieldmg  bine  oi^per  bydfoxide. 


Hydrogen  svlpkide,  yeOow  predpiUte  (OdS), 
insohibfe  in  ammoninm  snlphide  and  potauBsiam 
cyanide ;  solnble  in  nitiio  acid  and  not  difaite 
so^ozic  add.  Ammamia,  wbite  pieoipitate 
(CdH,0^,  readily  soluble  in  ezoess.  CauMic 
pakuh  or  soda^  wbite  piedpitate  (GdH^Ot) 
inaohible  in  ezoess.  An  ammoniacal  solution 
of  ammonimn  perehlorate  predmtates  wbite 
aoublB  perabkcate  (Od(aO«)t'iNH,). 

Till. 

Stannous  compounds.  Hydrogen  sul- 
Tpkide^  daxk-biown  predpitate  {SnS)>  soluble  in 
yellow  but  not  in  oolourieas  ammonium  sid- 
phide.  Mercuric  cUoride^  wbite  piedpitate 
(HgjCa,),  becoming  grey  (Hg). 

Stannic  compound*.  Hydrogen  sulpkide, 
yellow  piedpitate  (SnSt),  soluble  in  ammonium 
sulpbide;  appreciably  soluble  in  ammonium 
carbonate  (B^.  1894,  27,  2730);  soluble  in 
concentrated  bydxoohloiio  acid;  diflsolyee  in 
aqueous  oaustio  soda.  Stannic  ehhride,  boiled 
witb  copper  becomes  stannous  obloride.  Wben 
zinc  ana  piaHnmm  axe  placed  in  the  solution, 
no  black  stain  on  the  platinum ;  oiystals  of  tin 
on  the  zinc. 

AntliiMMiy. 

Hydrogen  sulphide,  onnse  predpitate  (SbtSa), 
soluble  in  ammonium  sul^de  and  in  concen- 
trated hydrochloric  add;  insoluble  in  ammo- 
nium carbonate.  Water  in  excess  (with  ammo- 
nium chloride  if  chlorides  are  absent),  white 
predpitate  (SbOGl),  soluble  in  hydrochloric  acid 
and  m  tartaric  add.  Zinc  and  pkUinum,  a 
black  stain  on  the  platinum  (Sb),  soluble  in 
nitric  add  and  in  ammonium  sulphide. 

AiMDle. 

Hydrogen  sulphide,  yellow  j[aedpitate,  soluble 
in  ammonium  sulphide  and  m  ammonium  car- 
bonate ;  insoluble  in  concentrated  hydrochloric 
add.  MelaBic  copper,  boiled  with  the  liquid  after 
acidifying  with  hydrochloric  add,  is  covered  with 
a  shining  grey  depodt  (AB,Gy,),  which,  when 
heated  in  a  tube,  yields  a  sublimate  of  arsenious 
oxide  (Reinsoh's  test)  (dark,  Chem.  Soc.  Trans. 
1808, 63,  884,  886).  Nascent  hydrogen  produced 
from  zinc  and  dilute  sulphuric  acid  reduces 
arsenic  componnds  to  volatile  arsine  (AsH,), 
which  decomposes  on  ^ntly  heating,  givin^j  an 
arsenic  deposit  soluble  m  aqueous  hyp<Kdilorite8. 
Antimony  compounds  under  these  conditions 
also  give  a  black  depodt  (antimony),  insoluble 
in  hypochlorites  (Marah's  test).  Zinc  and  caustic 
soda  reduce  arsenic  compounds,  liberating  arsine, 
which  produces  a  yellow-to-brown  stain  on 
mercuric  chloride  paper  (Gutceit's  test,  diem. 
8oa  Trans.  1001,  70,  716). 

Arsenites,  Ammonio-^Hver  nitrate,  yellow 
precipitate  (Ag,AsO,),  soluble  in  nitric  acid  and 
ammonia.  Ammonuhcvmric  sulphate,  bright- 
sreen  predpitate  (CuHAsOt),  turns  red  by 
boiling  with  caustic  soda. 

Arsenates.  Ammonio-siher  niiraie,  brick- 
red  predpitate  (As,A804),  soluble  in  nitric  acid 
and  ammonia.  Ammonium  chloride,  asnmonia, 
and  magnesium  sulphate,  white  crvstalline  pre- 
cipitate   (NH4MgA904).     Ammonto-^upric   suU 


pkaU,  pale-bine  prsciuitate,  tuznad  Uack  by 
boilinff  with  oaustio  soda. 

When  arsenie  add  or  anenates  an  present, 
they  should  be  rednoed  by  heating  with  snl- 
phurous  aoid  or  ammooiom  iodide  or  bydriodic 
aeid  (BuIL  Soc  ohim.  Bel^.  1000,  23,  88)  before 
spnjyiqg  hydrogen  sidphide  or  Rebisob's  test 
(tSher  and  Travcrs,  Chem.  Soo.  Trans.  1005, 
87,1370). 

Flitiiism. 

Hydrogen  sulphide,  brown  predpitate  (PtS,) 
on  beating,  soluble  in  ammonium  sulphide. 
Amsnonium  chloride  or  poiassimm  cmoride, 
yellow  crystalline  predpitate  (M,PtGl«)»  less 
soluble  in  presence  of  akohoL  Potassium  iodide, 
in  dilute  solution  red  colouration  (K,PtI,), 
very  ddicate  test.  Stannous  chloride,  in  dilute 
solution,  brownlsb-red  colouration,  delicate 
test. 

PiUadium. 

Hydrogen  sulphide,  black  precipitate  (PdS), 
insoluble  in  ammonium  sulpnide;  soluble  in 
hot  hydrochloric  aoid  and  in  aqua  regia.  Potas- 
sium iodide^  black  precipitate  (PdIA  somewhat 
soluble  in  excess.  Mercuric  cyantde,  yellowish 
white,  gneUtinous  precipitate  (FdQy|),  readily 
soluble  in  ammonia.  Ammonium  cUoride,  no 
predpitate  (diff.  from  Pt) ;  on  addition  of  chlorine 
water,  oranoe  predpitate  ((NH4)|PdCl«).  Potas- 
sium  chlorSe,  precipitate  (2KCi*FdCl,)  only  in 
very  concentrated  solutions. 

o-Nitrdso-jS-naphthol  dissolved  in  60  p.0. 
acetic  add  gives  a  voluminous  red-brown  pre- 
dpitate in  solutions  containing  only  as  little  as 
1  part  paUadium  in  1,000,000. 

Iridnmu 

Hydrogen  sulphide,  decolourisation  followed 
by  brown  precipitate  (Ir^Sa),  soluble  in  ammo- 
mum  sulpbide.  Caustic  potash,  a  greenish 
colouration  which,  on  heatinff  with  exposure  to 
air,  changes  slowly  to  azure  Uue  (diff.  from  Pt). 
Ammonium  chloride  or  potassium  chloride,  dark- 
brown  or  red  predpitate  ^double  chloride), 
insoluble  in  a  saturated  solution  of  the  predpi- 
tant.  Both  salts  become  olive  f^reen  with 
potasdnm  nitrite  and  other  reducing  agents, 
espedallv  in  hot  solutions.  Strong  sulphuric 
acid  ana  ammonium  nitrate,  on  heating,  blue 
colouration. 

Omdurn. 

Hydrogen  sulphide,  in  acid  but  not  in  neutral 
solution,  black  precipitate  (OSS4),  insoluble  in 
ammonium  sulpnide.  Nitric  add  on  boiling 
oxidises  osmium  compounds  to  osmic  tetrozide 
(OSO4),  characteristic  odour  and  yellow  solution 
in  caustic  soda. 

ButheDlum. 

Hydrogen  sulphide,  blue  solution  followed  by 
brown  predpitate  of  ruthenium  sulphide. 
Sodium  Uiiostuphate  in  ammoniacal  solution  to 
dilute  solutions  of  ruthenium,  a  purplish -red 
colouration.  Zinc  reduces  RuClt,  giving  a  blue 
solution  and  then  precipitating  ruthenium. 

Rhodium. 

Hydrogen  sulphide,  on  warming,  black  pre- 
cipitate (RhiSg),  insoluble  in  ammonium  sul- 
phide; soluble  in  boiling  nitric  acid.  Potassium 
niirile,  warmed  with  s<Klium  rhodium  chloride, 
gives  orange-yellow  precipitate  (K|Rh(N0|)4) 

Gold. 

Hydrogen  sulphide,  black  precipitate  (Au,S,) 
in  cold,  brovn  precipitate  (AU|S)  in  hot,  solu- 


238 


ANALYSIS. 


tion;  Bolable  in  yellow  ammonium  sulphide. 
Oxalic  add  or  ferrous  stdphatef  brown  or  purple 
medpitate^  yellow  and  liiBtrons  when  nibbed. 
Stannous  and  stannic  chlorides,  purplish  pre- 
dpitate,  insoluble  in  hydroonlorio  add. 
Hffdroqen  peroxide,  in  very  dilute  alkaline  solu- 
tion, liberates  finely  divided  gold  having  a 
beautiful  blue  shimmer. 

A  solution  of  colourless  m-phenylenediamine 
(6 :  1000)  gives  an  immediate  violet  colouration 
with  a  dilute  solution  of  a  gold  salt. 

Moiybdeniim. 

Hydrogen  eulMde^  brownish-black  predpi- 
tate  (MoSg)  on  heating,  soluble  in  ammaninm 
sulphide.  Sodium  phosphate^  in  presenoe  of 
nitric  add,  yellow  predpitate  on  heating, 
soluble  in  ammonia  and  in  excess  of  the  alkaline 
phoq^te.  Poiassivm  IhiocyanaU  and  zinc  or 
stannous  chloride,  red  colouration  due  to 
Mo(GNS)4  soluble  in  ether.  Canceniraied  sul- 
vihmic  acid,  when  stronffly  heated  with  moly- 
iidenum  compounds,  develoi»s  a  deep-blue 
colouration.  FKen/^ydratine,  in  60  p.a  acetic 
add,  red  colouration  (Ser.  1903,  36,  612). 

Hydrogen  peroxide,  in  presence  of  ammonia 
gives  a  cherry-red  colouration. 

Setoniiim. 

Hydrogen  suMUde,  yellow  predpitate,  be- 
comiziff  dark  on  neating,  soluble  in  ammonium 
sulphide.  Sulphurous  acid,  in  presenoe  of  hydro- 
chloric add,  a  red  predpitate,  which  becomes 
grey  on  heating,  and  is  soluble  in  potasdum 
cyuiide.  Stannous  chloride  and  other  reducing 
aoents  behave  in  a  similar  manner.  Barium 
chhride,  (i.)  white  predpitate  (BaSeOg),  soluble 
in  dilute  hydrochloric  add ;  (ii. )  white  predpitate 
(BaSe04),  insoluble  in  dilute  hydrochloric  add ; 
soluble  in  the  strong  add,  evolving  chlorine. 
Concentrated  sulphuric  acid,  green  colouration. 

TeUurinm. 

Hydrogen  sulphide,  brown  predpitate  (TeSt) 
at  once  from  tellurites,  but  from  tellurates  only 
after  boiling  with  hydrochloric  acid.  Potassium 
iodide,  to  tellurite  in  add  solution,  black  pre- 
cipitate (Tell).  Reducing  agents  (SnClt»Zn), 
black  predpitate  (Te).  Oonceniraled  sulphuric 
acid,  carmine  colouration. 

Almnlnlum. 

Ammonia,  white  gelatinous  predpitate 
(AlH^Oa)*  insoluble  in  excess  and  in  ammonium 
carbonate ;  soluble  in  adds.  Cauttic  potash  or 
soda,  white  gelatinous  predpitate  (AlfHO,), 
soluble  in  excess;  reprediuitated  on  adding 
ammonium  chloride  ana  heating. 

Gbromittm. 

Chromic  salts.  Ammonia,  ffreenish  or 
purplish  predpitate  (CrH,Os),  soluble  in  adds ; 
insoluble  in  ammonium  carbonate.  Caustic 
potash  or  sodj,  green  precipitate  (CrH,Ot), 
soluble  in  excess,  but  repredpitated  on  boilmff. 

Ohromates.  Hydrogen  sulphide  in  add  soiu- 
tion,  reduction  to  chromic  salt  with  change  of 
colour  to  green.  Lead  acetate,  bright  yellow 
precipitate  (PbCr04),  insoluble  in  acetic  acid. 
Siher  nitrate,  dark-red  precipitate  (AgiCrOf), 
soluble  in  nitric  add. 

Iron. 

Ferrous  salts.  Ammonium  sulphide,  h]a4ik 
precipitate  (FeS),  soluble  in  acids.  Ammonia  or 
causttc  potash  ot  soda,  white  precipitate,  rapidly 
becoming  green  and  then  brown.  Potassium 
ferrocyanide,  white    precipitate,   gradually   be- 


coming dark  blue.  Potassium  Jerricyanide, 
dark-blue  predpitate  (Fes(FeCy,)t).  Potassium 
thiocyanate,  no  reaction. 

ferric  saltSm  Ammonium  sulphide,  black 
predpitate  .  (2FeS  +  S,  or  FejS,),  soluble  in 
acids.  Ammonia  or  caustic  potash  or  soda, 
reddish-brown  precipitate  (FeHgOg),  soluble  in 
adds.  Potassium  ferrocyanide,  diurk-blue  pre- 
dpitate (Fe4(FeGy4)g),  insoluble  in  dilute  acids. 
Po<asm«m/(emief/afii£;,  no  predpitate;  jo^reenish- 
brown  colouration.  Pctaseium  thwcwinaU, 
blood-red  colouration;  not  affected  by  boiling 
or  by  hydrodiloric  add. 

ThorlmiL 

Ammonia^  caustic  soda,  or  potash,  white 
gelatinous  predpitate  (Th(0H)4),  insoluble  in 
excess.  AmmoMum  or  sodium  carbonate,  white 
precipitate,  banc  carbonate ;  soluble  in  excess. 
Oxal&  acid,  white  predpitate  {Th(0a04)„2H,0), 
insoluble  in  excess  and  insoluble  in  mineral  acids, 
but  salable  in  ammonium  oxalate.  Potassium 
fluoride  or  hydrofiuoric  acid,  niiite  predpitate 
(ThFi).  Potassium  sulphate,  white  crystalline 
precipitate  (2KtS04,Th(S04)4,2H,0). 

Cerium. 

Ammonia,  white  precipitate  of  basic  salt»  In- 
soluble in  excess,  uaustte  potash  or  soda,  ^ite 
predpitate  (Ce(OH),),  insoraUe  in  excess ;  be- 
comes yellow  when  exposed  to  air.  Oxalic  acid, 
white  precipitate  (0es(^t04)s)f  insoluble  in  ex- 
cess, but  soluble  in  a  large  quantity  of  hydro- 
chloric add.  Potassium  sulphate,  white  pro- 
cipitate  even  in  somewhat  aovi  solutions 
(GeK,(S04),)f  insoluble  in  saturated  solution 
of  potassium  sulphate.  Hydrogen  peroxide,  in 
ammoiuacsl  solution,  orange-brown  predpitate. 

GladnmiL 

Ammonia,  white  predpitate  (Q1H,0|),  in- 
soluble in  excess.  Causttc  potash  or  soda,  the 
same  precipitate,  soluble  in  excess,  but  repre- 
dpitated on  boiling  (diff.  from  Al).  ilfiimoiM«iii 
carbonate,  white  procipitate,  easily  soluble  in 
excess  (diff.  from  Al). 

Glacial  acetic  add  ^aK>\Yes  Gl(OH)s  or  GICO^, 
and  the  residue,  after  evaporating  to  dryness,  is 
the  bade  acetate  (01 40(011, -CX),).),  readily 
soluble  in  chloroform,  ether,  acetone,  the  alcohols^ 
and  other  orsanic  media;  dissolves  unchanged 
in  glacial  acetic  add;  it  mdto at  283*-284*,  and 
can  be  sublimed  without  deoompodtion.  Sodium 
hydrogen  carbonate,  10  p.o.  dissolves  Ql(OH)^; 
dilution  to  1  p.c  causes  reprecipitation. 

Unmlam. 

Ammonia,  caustic  potash,  or  soda,  veUow  pro- 
cipitate^  insoluble  in  excess,  but  readily  soluble 
in  ammonium  carbonate.  Ammonium  sulphide, 
brown  precipitate,  readily  soluble  in  ammonium 
oarbonata.  Potassium  ferrocyanide,  chocolate- 
brown  precipitate,  readilv  decomposed  by 
alkalis,  yidding  yellow  alkau  diuranates. 

TltaniimL 

Ammonia,  caustic  potash,  or  soda,  or  ammo- 
nium sulphide,  white  precipitate  (H.TiO,), 
insoluble  in  excess ;  soluble  in  dilute  sulphuric 
and  hydrochloric  acids.  Potassium  ferrocyanide^ 
dark- brown  predpitate.  Sodium  (hiosulphate, 
complete  predpitotion  on  boiling.  Hydrogen 
peroxide,  te  a  slightiv  acid  solution  of  titanium 
sulphate ;  orange-red  colouration  ;  weakened  by 
fluorides^  A  solution  of  thymol  in  acetic  acid 
mixed  with  sulphuric  acid  gives  a  more  intense 
colouration,  lUso  bleached  by  fluorides.     ReJue* 


ANALYSI& 


2S9 


ing  agents  (SnCl,  or  Zn  and  HCl)  produce  a 
Tiokt  odoQiation  (Tia,). 

Catechol  added  to  dilate  Bolutioiia  of  titanic 
or  tttanoDB  salts,  yellowish-orange  colouration, 
Tety  delicate  test,  but  interfered  with  by  mineral 
acids  or  alkalis  (Ber.  1909, 42,  4341). 

ZiraoDimiu 

Ammonia,  ammonium  niiphidet  cauMie  soda, 
white  gelatinous  nrecipitate^  dissolving  in  dilate 
add,  bat  less  reaoily  alter  boiling ;  precipitation 
prevented  by  tartaric  acid«  OacaUe  oM,  white 
precipitate  (Zs{Cfi^^,  readily  salable  in  am- 
moniom  oxalate  or  in  excess  of  oxalic  acid. 
Hifdfogen  penande,  white  milky  precipitate 
(Zr.OJ,  evolvinff  chlorine  when  boiled  with 
hytuochloric  adoL  Twrmeric  paper,  moistened 
with  acid  solution  of  sirconiam  salt,  becomes 
reddish- brown  on  drying. 

Zine. 

Ammon4um  sulphide,  white  precipitate  (ZnS), 
solnble  in  dilate  hydrochloric  add ;  insoluble  in 
acetic  add  and  in  alkalis.  Caustic  potash  or 
soda,  white  predpitate  (ZnHaO,),  soluble  in 
excess.  Potassium  ferrocyanidi,  white  pre- 
dpitate, insoluble  in  dilute  hydrochloric  add 
{Zn^eCy^. 

Manganese. 

Ammonium  sulphide,  pink  precipitate  (IfnS), 
soluble  in  dilute  hydroohlorio  add  and  in 
acetic  add.  CausUe  potash  or  soda,  white  pre- 
cipitate (MnH^Oa),  insoluble  in  excess,  becoming 
brown  on  exposure  to  air.  Boiled  with  dilute 
nitric  acid  uid  lead  peroxide  (in  absence  of 
chlorine),  a  purplish  crimson  solution  of  per- 
manganic add. 

MckeL 

Ammonium  sulphide,  black  precipitate  (NiS), 
somewhat  soluble  in  excess ;  msoluble  in  cold 
dilate  hydrochloric  add ;  soluble  in  strong  adds. 
Causlic  pofaeh  or  soda,  pale-green  precipitate 
(NiH^Oa),  insoluble  in  excess.  Potassium  cyanide, 

Sredpitate  (NiGyt)«  soluble  in  excess,  forming 
fiCy2f2KCy,  wuoh  is  not  altered  when  boiled 
with  exposure  to  air.  This  solution,  heated 
with  excess  of  sodium  hypochlorite  solution, 
or  mixed  with  bromine  in  the  cold,  yidds  a 
predpitate  of  black  nickelic  hydroxide  (MiH.O.). 
Dimdhylglyoxime  (CH,*C(NOH)C(NOH)*GH,) 
(Tschugaeo,  Ber.  1905,  38,  2520),  added  to  am- 
moniacal  or  acetic  acid  solution  of  nickel  salts, 
scarlet  predpitate  (distinction  from  cobalt). 
Dicuanodiamtdine  (H.  Grossmann  and  .  W. 
Heilbom,  Ber.  1908,  41,  1878)  added  to  am- 
moniacal  solutions  of  cobalt  and  nickel  salts 
containing  excess  of  sucrose,  yellow  crystalline 
predpitate  (Ni(N4H(GaO)t,2H,0),  the  presence 
of  coWt  indicated  by  the  reddish-violet  colour 
of  the  solution. 

An  alcoholic  ammoniacal  solution  of  a- 
benzildioxime  gives  an  intense  red  precipitate 
Cmfit^fi^Jifi  (Tschugaeff,  Zeitson.  anorg. 
Chem.  1905,  46,  144;  Ataok,  Analyst,  1913, 
316). 
Cobalt 

Ammonium  sulphide,  black  precipitate  (CoS), 
insoluble  in  cold  dilute  hydroohloric  add ; 
solnble  in  strong  adds.  Causlte  potash,  pale-blue 
predpitate  (CoH,Os),  slightly  soluble  in  excess, 
formmg  a  blue  solution*  Potassium  cyanide, 
predpitate  (OoQy.),  soluble  in  excess,  forming 
CoCy2,4KC>,  and  when  this  solution  is  boiled 
with  exposure  to  air  it  is  changed  to  KtCoCy^, 


which  is  not  precipitated  by  sodium  hypoohloride 
or  bromine.  FokMS&ium  wOrite  to  dilute  acetio 
acid  solutions,  yellow  oystaUine  precipitate 
(K,Go(NO,)«).  Nitroso-fi-naphthol  NO-0|^«>OH 
minski  and  Knorre,  Ber.  18,  699)  dissolved  in 
dilute  acetio  acid  added  to  feebly  add  solu- 
tions of  cobalt  and  nickel,  brick-red  precipi- 
tate (OHNO-Gi^fO),):  solution  examined  for 
nickel  (CJhaplin,  J.  Amer.  C3iem.  Soc  1907,  29, 
1029). 

Vanadlmn. 

Ammonium  sulphide,  dark-brown  solution, 
which  when  acidified  yidds  a  brown  predpitate 
(¥284).  Ammonium  chloride,  white  predpitate 
of  ammonium  meta-vanadate  (NH^VOg).  PotoJ- 
sium  ferrocyanide,   in   acid   solution,   a  green 

Sscipitate.  If  a  solution  of  an  alkaline  vans- 
te  IS  a^tated  with  hydrogen  peromde  and  ether, 
the  solution  acquires  a  deep  purplish-xed  colour, 
but  the  ether  romains  colourless.  MUd  re- 
ducing agents  (S0|,  H|8,  HBr,  alcohol,  Ac) 
reduce  vanadates  m  add  solutions  to  blue 
divanadyl  salts.  Strong  reducing  agents  (dno 
and  aluminium  with  acids)  produce  a  series  of 
colour  changes— blue,  green,  and  violet. 

Colnmliliim. 

Hydrogen  fluoride  and  potassium  fluoride 
produce  potassium  oolnmbo-fluoride,  whioh 
when  boiled  in  aqueous  solution  yidds  potasuum 
oolumbium  oxy^uoride  (K,GbOF|,H20)  (solu- 
bility 1  in  12*5  cold  water),  mineral  adds, 
partial  precipitation  of  oolumbio  add  firom 
alkali  cotumbates :  tine  and  add,  blue  coloura- 
tion, turning  brown;  potassium  ferrocyanide, 
greyish-green  precipitate. 

Tantalum. 

Hydrogen  fluoride  and  fotassium  fluoride 
produce  potassium  tantalonuoride  (^iTaF,) 
(solubility  1  in  154  cold  water),  separating  in 
colouriess  needles.  Mineral  acids,  white  pre- 
dpitate of  tantalic  acid.  Potassium  ferrocy- 
anide, reddish-brown  predpitate  {v.  Weiss  and 
Landecker,  Zdtsch.  anorg.  Chem.  1909,  04,  65). 

Catoliim. 

Ammonium  carhonate,  white  predpitate 
(GaCOa),  soluble  in  acids.  Sulphuric  add, 
white  precipitate  only  in  very  concentrated  solu- 
tions. Ammonium  oxalate,  white  predpitate 
(CaCiO^),  insoluble  in  acetic  and  oxslio  adds, 
but  soluble  in  hydroohlorio  acid. 

Strontlam. 

Ammonium  carhonatep  white  precipitate, 
soluble  in  acids  (SrCO,).  Ammonium  sulphate, 
white  precipitate,  especially  on  boilinff.  Am- 
monium oxalate,  white  precipitate  (SxOtO^), 
soluble  iu  hvdrochloric  ado  ;  insoluble  in  aoetic 
acid.  Sulphuric  add  or  ealcium  sulphoUe,  white 
precipitate  (SrS04),  forming  slowly. 

Barium. 

Ammonium  carbonate,  white  precipitate 
(BaCO,),  soluble  in  adds.  Ammonium  oxalate, 
white  precipitate  (BaC|04),  soluble  in  hydro- 
ohlorio acid  ;  insoluble  in  acetio  acid.  Sulphuric 
add  or  caldum  sulphate,  an  immediate  white 
predpitate,  insoluble  in  acids  and  sikaliB.  Potas- 
num  chromate,  yellow  precipitate  (BaGr04), 
msoluble  in  acetio  acid. 

Magnesium. 

Sodium  phosphate,  in  presence  of  ammonia 
and  ammonium  chloride,  white  precipitate, 
rapidly  becoming  crystalline  (NH4MgP046H,0). 
Forms   slowly    in   dilute   solutions,    formation 


240 


ANALIWTS. 


being  accelerated  by  agitation  and  bv  rubbing 
the  sides  of  the  beaker  with  a  glass  rod ;  soluble 
in  aoids. 

Potassiiim. 

ChioropkUinic  add  HaPtCl^  yellow  crystalline 
precipitate  (K|PtCl.)»  somewhat  soluble  in  water, 
insoluble  in  aioohol.  Sodium  hydrogen  tartrate, 
in  neutral  or  feebly  acid  solutions,  a  white  crys- 
talline precipitate  (KHO4H4OC),  forming  slowly 
in  dilute  solutions.  If  the  solution  contains  free 
mineral  acids,  nearly  neutralise  with  soda  and 
add  sodium  aoetate  (c/.  Winkler,  Zeitech. 
angew.  Chem.  1913,  26,  208;  Analyst,  1913, 
296). 

Sodium  ccbaUiniirite  in  acetic  acid  solution, 
yellow  preoipitate  (K.NaCo(NO,).).  Sodium 
l-amino'fi'naphihol'6'eulphonate  (eikonogen)  in 
5-10  p.c.  solutions,  crystalline  precipitate 
(KSO,'G,»H,(NH,)OH) ;  negative  results  with 
ammonium  and  magnesium  salts  (Alvarez, 
Chem.  80c.  Abstr.  1905,  ii.  355). 

Ammonium. 

Ammonium  salts  are  readily  volatile.  Heated 
with  lime,  eatuiie  potash,  or  soda,  ammonia  gas 
is  given  off,  and  is  recognised  by  its  smell  and 
its  action  on  test  paper. 

ChhropkUinie  tMCtd,  yeUow  crystalline  pre- 
cipitate ((NH  J^ta«),  sUffhtiy  soluble  in  water  : 
insoluble  in  alcohol.  Sodium  hydrogen  tartraU, 
white  crystalline  precipitate  (NH4HC4H40«), 
forming  slowly  in  dilute  solutions. 

Nessler's  reagent  (K^Hgl,  and  KOH),  brown- 
ish-red precipitate  or  colouration  (NHg,I,H.O), 
very  delicate  test.  Equally  delicate  is  the  blue 
colouration  which  is  developed  when  an  ammo- 
nium compound  is  treated^  with  a  solution  of 
phenol  ana  a  hypochlorite  (eau  de  Javel). 

Sodium.     • 

Flame  colouration,  intense  yellow. 

Although  all  sodium  salts  are  more  or  less 
soluble,  some  dissolve  only  sparingly,  e.g.  sodium 
oxalate  and  sodium  a-naphthylamine-8-Bul- 
phonate. 

Poiassium  pyroaniimonate,  white  crystalline 
precipitate  (Na,H^b,0/6HsO)  (J.  Amer.  Chem. 
Soo.  1909,  31,  634) ;  from  neutral  or  slightly 
alkaline  solutions. 

Dihydroxytartarie  add,  colourless  preoipitate 
(CO^aC(OH),C(OH),CO^a)  (Fenton, Chem. 
800.  Trans.  1895,  67,  48).  Solution  of  bismuth 
nitrate  in  50  p.c.  potassium  nitrite  containing 
ccBsium  nitrite,  yellow  crystalline  precipitate 
(5Bi(NO.)„9CsNOt,6NaNO,) ;  very  delicate 
test,  not  interfered  with  by  lithium  and  metals 
of  alkaline  earths  (Ball,  Chem.  Soc.  Trans.  1909, 
95,  2126).  Sodium  chloride,  obtained  by  slow 
evaporation  of  a  solution  acidified  with  hydro- 
chloric acid,  crystallises  in  distinct  cubes. 

LttUum. 

ChhropkUinie  add,  no  precipitate. 

Sodium  ^^osphalte,  in  alkaline  solution ;  white 
precipitate  {lA^OX  soluble  in  hydrochloric  acid, 
not  reprecipitated  by  ammonia  except  on  boiling. 
Lithium  chloride  is  soluble  in  etnyl  or  amyl 
aioohol,  and  in  pyridine.  Ammonium  hydrogen 
fiuoride,  white  precipitate  (LiF). 

CsBdunu 

Flame  cohuration,  violet. 

Ohlorophtinie  add,  yrUow  crvstalline  pre- 
cipitate (CssPtClf),  insoluble  in  boiling  water, 
Tariarie  add,  crystalline  precipitate,  some- 
what soluble  in  water.    Stannic  chloride,  white 


precipitate  (Cs,SqC1«).  Lead  chloride  dissolved 
in  chlorine  water,  yellow  precipitate  (CB«PbCl«). 
Cesium  carbonate  is  soluble  in  alcohol  (diff. 
from  K,  Rb). 

Rubidium. 

Flame  colouration,  violet. 

Chloroplatinic  acid,  yellow  crystalline  pre- 
cipitate (RbtPta«),  insoluble  in  boiling  water. 
Tartaric  acid,  white  crystalline  precipitate,  less 
soluble  than  the  cesium  compound  (Reactions 
of  Gs  and  Rb,  v.  Wells,  Amor.  J.  Soi.  [31  43,  17 
and  46,  186,  and  265). 

AoiD  Radioaijs. 

The  acid  radicals  axe  arranged  paitlv  in  the 
order  of  the  systematic  separation  and  partly 
with  a  view  to  brin^  together  those  aoids  which 
%re  commonly  associated  or  which  resemble  one 
another  in  their  reactions.  In  all  oases,  unless 
otherwise  specified,  it  is  important  that  the 
solution  should  be  neutral. 

SulfKhates. 

Barium  chloride,  white  precipitate  (BaS04), 
insoluble  in  aoids, and  alkalii. 

Sulphitet. 

Hydrochloric  add,  sulphur  dioxide  evolved, 
but  no  sulphur  piecipitated.  Barium  chloride, 
white  preoipitate  (BaSO,),  soluble  in  hydro- 
chloric acid.  Iodine  solution,  sulphites  are  con- 
verted into  sulphates.  Neutralise,  then  slightly 
acidify  with  acetic  acid;  add  excess  of  sine 
sulphate,  a  small  quantity  of  sodium  niUro- 
prusside  and  potasdum  ferrocyanide.  The  preoi- 
pitate of  zinc  feiroovanide  has  a  pink  oolour. 

Strontium  chloride,  white  preoipitate  (SrSO,), 
different  from  tluosnlphate  SrStO,,  being  much 
more  soluble. 

Hyposulphltei  ('liydrofuiphitot,'  e^.  Unfifi^, 
2H,0)  owe  their  technical  application  to  their 
reducing  action  on  indigotin  and  its  sulphonic 
aoida — the  colour  is  dischaiged  (indjgo-white). 
Silver  nitrate,  black  preoipitate  (Ag).  Mercuric 
chloride,  black  preoipitate  (Hg).  Copper  sulphate, 
reddish  precipitate  (Cu  and  Cu^H,),  in  veiy 
dilute  solution,  colloidal  copper. 

Thiosnlphatef. 

Hydrochloric  add,  sulphur  dioxide  evolved 
and  sulphur  precipitated.  Silver  nitrate,  white 
preoipitate  (AfftS|0,),  rapidly  ohanffing  to  black 
(AgtS),  soluUe  in  exoees  of  alkuine  thioeul- 
phate,  forming  a  much  more  stable  solution. 
With  sodium  nitroprusside,  dnc  sulphate,  and 
potasdum  ferroeyamde,  the  precipitate  is  white. 
Iodine  solution  converts  soluble  thiosulphates 
into  tetrathionates,  which  ^ve  no  preoipitate 
witii  barium  chloride.  Feme  chloride,  transient 
violet  colouration  (FeJS|0,),). 

Pwiulnhitet  {e^.  rLJSfi^), 

The  dry  salts  evolve  oxygen  on  heating. 
Barium  chloride,  no  precipitate  in  the  cold,  on 
warming  oxygen  evolved  and  Ba804  precipitated. 
SUver  nitrate,  black  precipitate  (silver  peroxide). 
Other  metallic  salts  (Pb,  Mn,  Co,  and  Ni)  yield 
their  hydrated  peroxides. 

Monoper sulphuric  acid  {Carols  add) 
HO*SOa*0-OH,  produced  by  adding  a  persulphate 
to  cold  concentrated  sulphuric  acid,  and  pouring 
the  mixture  on  to  ice.  Aromatic  amines  (e.g. 
p-Cl'C4H4-NH,)  give  coloured  oxidation  products 
with  persulphates  and  nitroso-  compounds  {e.g, 
a-C|H4N0)  with  Caro's acid. 

Thionie  adds  {v,  Chem.  Soc.  Trans.  1880, 608). 


ANALYSia 


241 


HydroeKLonc  acid,  in  moet  cues  eyolation  of 
hydrogen  mlphide,  especially  on  heating.  Lead  ! 
miSraU  or  acetaU^  Uaok  precipitate  (PbS).  ' 
SQmr  fUjfrale,  black  precipitate  (Ag,S)»  in- 
sofaifafe  in  ammonia^  sodinm  thiosolpnate,  and 
potassium  cyanide.  Sodium  nitroprusnde^  in 
^iiraim^  solations  an  intense  but  somewhat 
fngitaTe  Tiolet  colouration. 


Barium  cklonde,  white  precipitate  Ba,(P04)t, 
sdhibto  in  dilute  acida.  dahium  ekloTide,  white 
precipitate  (0a,(P04)t)»  soluble  in  acetic  acid. 
aiher  uiitaUt  vdlow  prediMtate  ( Ag^PO^ ),  soluble 
in  nitric  acdd  and  in  ammonia.  Pyrophos- 
phates and  metaphosf hates  give  iHiite 
precipitates  of  their  silyer  salts  with  silver 
nitrate,  but  metaphosphatas  alone*  unlike  ortho- 
and  pyro-phoeph«teSy  coagulate  albumin.  Mag- 
nesium ndphate^  in  presence  of  ammonium 
chlcride  and  ammonia,  white  crystalline  pre- 
cipitote  (NH«BlgPO«6H.O),  soluble  in  acids. 
Ammcmium  molf/bdaie,  in  nitric  acid  solution, 
on  heating,  a  yellow  precipitate  ((NH4),P0«* 
12MoOa)  Bolubfa  in  ammonia,  and  soluble  in 
excess  of  an  alkaline  phosphate. 

Barium  eUoride,  white  precipitote  (BaHPO.), 
soluble  in  l\ydrochloric  acid.  Silver  nitrate, 
precipitate  of  metallic  silver,  especially  in  pre- 
sence of  ammonia,  and  on  heatmf .  Mercuric 
chloride,  white  precipitate  (Hg^ClA  becoming 
grey  (Sg)»  Heated  with  nitric  acid,  phosphites 
are  converted  into  phosphates.  Heated  alone, 
{^lomAiites  evolve  phosjAine.  Copper  stdpkate, 
pale  blue  precipitate. 

Hypophospnteet. 

Heated  idone,  evolve  phosphine.  Barium 
chloride,  white  predpitete  oiuy  in  strong  solution 
(Ba(H,FO.)t).  saver  niiraie,  metallic  silver 
precipitated.  Copfer  sulphate,  brown  preci- 
pitate, cuprous  hydride  (CusH,). 

Carbonatai. 

Bjfdrochloric  add,  effervescence,  with  evolu- 
tion of  carbonic  anhydride,  which  turns  lime 
water  turbid.  Barium  chloride,  white  pre- 
dpitete (BaOOa),  soluble  in  acids  with  efferves- 
cence. Mercuric  chloride,  red  precipitote  (basic 
carbonate) ;  bicarbonates  give  only  a  yellowish 
opalescence.  Calcium  sulphate,  white  precipitote, 
immediately  with  carbonate,  but  only  after 
standing  with  bicarbonate  (I/eys,  J.  Fharm. 
Ghim.  1897,  (vL)  6,  441). 

Borates. 

Barium  chloride,  white  precipitote  in  not  too 
dilute  solutions,  soluble  in  acids.  Silver  nitrate, 
in  strong  solution,  white  precipitote  (AgBOt) 
in  dQute  solution,  dark-grey  deposit  (AgaO). 

Mix  the  solid  substonoe  with  concentrated 
suli^urio  acid  in  a  small  crucible,  add  alcohol, 
ana  ignite ;  the  alcohol  flame  is  green,  especially 
at  the  edges.  Mix  the  solid  substonce  with  three 
parte  potassium  hydrogen  sulphate  and  one  part 
powdered  fluorspar,  and  heat  on  platinum  wire 
m  the  cold  area  of  the  flame;  a  bright-green 
colouration  (due  to  BF,)  is  obs^ed.  Turmeric 
paper,  moistened  with  acid  solution  of  boric 
acid,  becomes  reddish  brown  on  drying. 

Sffleatas. 

Solutions  of  silicates  heated  with  acids,  am- 
monium chloride,  or  ammonium  carbonate, 
deposit  silicic  acid.    Dilute  solutions  must  be 

Vol.  I.— r. 


evaporated  to  dryness,  and  on  treating  the 
residne  with  dilute  hydrochloric  acid  insoluble 
silica  is  left. 

Most  silicates  are  insoluble  in  water ;  some 
are  deoompoeed  by  acids ;  others  are  only  de- 
composed oy  fusion  with  about  four  times  their 
weight  of  a  mixture  of  equal  parte  of  sodium 
and  potassium  carbonates. 

Sflleolliiorid«B. 

Concentrated  sulphuric  acid,  in  leaden  or 
platinum  capsule,  hydrogen  fluoride  and  silicon 
fluoride  are  evolved.  Bwium  chloride,  colourless 
crystalline  precipitoto  BaSiF*.  Silicofluorides 
on  heating  evolve  silicon  fluoride,  leaving 
residues  of  metallic  fluorides. 

Thorium  nitrate  nrecipitotes  hydrofluoailicio 
acid  quantitotively  rrom  soluble  hydrofluosili- 
cates. 

Ozilatst. 

Barium  chloride  or  calcium  chloride,  white 
precipitote,  insoluble  in  acetic  acid,  but  soluble 
m  hvdrochloric  acid. 

Acidify  with  sulphuric  acid,  and  add  potas- 
sium permanganate  ;  the  colour  of  the  latter  is 
rapidly  and  completely  discharj^ed. 

Heat  the  sohd  substance  with  concentrated 
sulphuric  add;  carbonic  anhydride  and  car- 
bonic oxide  are  evolved.  The  latter  bums  with 
a  blue  flame. 

Fluorides. 

Barium  chloride,  white  precipitoto  (BaF^), 
soluble  in  hydrochloric  add.  Silver  nitrate,  no 
precipitote  with  soluble  fluorides.  Concentrated 
sulphuric  acid,  especially  when  heated,  produces 
hydrogen  fluoride,  which  attacks  glass.  The 
substance  and  add  are  placed  in  a  small  leaden 
or  platinum  crucible,  which  \b  covered  with  a 
wateh-fflass  protected  by  a  thin  coating  of  wax, 
part  of  whicn  has  been  scratehed  away  so  as  to 
expose  the  glass. 

Thorium  nitrate  added  to  a  solution  of  an 
alkali  fluoride  acidified  with  acetic  or  nitric  acid 
gives  a  gelatinous  precipitoto  of  thorium  fluoride 
ThF-. 

Chlorides. 

Silver  nitnUe,  a  white  precipitoto  (Agd), 
insoluble  in  nitric  acid,  soluble  in  ammonia ; 
darkens  when  exposed  to  light.  Manganese  di- 
oxide and  sulphuric  acid,  evolution  of  chlorine 
on  heating.  Potassium  dichromate  and  strong 
stdphuric  acid,  evolution  of  chromyl  chloride 
on  heating.  This  forms  with  ammonia  a  yellow 
solution  of  ammonium  ohromate. 

Bromides. 

Silver  nitrate,  yeUowish-white  precipitote 
(AgBr),  insoluble  in  nitric  acid;  moderately 
soluble  in  ammonia ;  readily  soluble  in  potassium 
cyanide  or  sodium  thiosulphate.  manganese 
dioxide  and  sulphuric  acid,  orange  vapours 
of  bromine,  which  turn  starch  paste  orange. 
Chlorine  water  liberates  bromine,  which  <ns- 
solves  in  ether  or  carbon  disulphide,  forming  an 
orange-brown  solution.  Bromides  heated  with 
potassium  dichromate  and  strong  sulphuric  acid 
yield  bromine,  which  forms  a  odourless  solution 
with  ammonia. 
Iodides. 

Sih^er  nitrate,  yellow  precipitate  (Agl),  in- 
soluble in  nitric  acid  or  ammonia ;  soluble 
in  potassium  cyanide  or  sodium  thiosulphate. 
Manganese  dioxide  and  sulphuric  acid  yield 
violet  vapours  of  iodine,  which  colour  starch 

R 


842 


ANALYSia 


paste  blue.  Chlorine  waler,  bromine  vxUer,  -or 
potasnuni  dichromcUe  in  presence  of  hydrocJUoric 
acidf  liberates  iodine,  which  turns  starch  paste  an 
intense  blue.  The  colour  disappears  on  heating, 
and  reappears  on  cooling.  The  liberated  iodine 
may  be  affitaufd  with  carbon  disulphide  or  chlo- 
roform^  when  it  yields  a  violet  solution.  liUro- 
gen  oxides  in  sulphuric  acid  likewise  liberate 
iodine,  but  do  not  liberate  bromine  unless 
added  in  large  excess. 

Cyanides. 

Silver  niiraie,  white  precipitate  (AgCN),  in- 
soluble in  nitric  acid,  but  soluble  in  ammonia, 
sodium  thiosulphate,  or  excess  of  the  alkaline 
cyanide. 

Add  ferric  chloride  and  ferrous  sulphate; 
make  alkaline  with  caustic  potash  or  soda,  and 
then  acidify  with  hydrochloric  acid.    A  dark 
blue  precipitate  of  Bmssian  blue  is  formed. 

Evaporate  the  solution  with  an  excess  of 
yellow  ammonium  sulphide  to  complete  dryness 
on  a  water-bath ;  dissolve  in  very  dilute  hydro- 
chlorie  acid,  and  add  ferric  chloride;  a  blood- 
red  colouration  is  produced. 

Most  cyanides  evolve  hydrocyanic  acid,  re- 
cognisable by  the  smelly  when  treated  with 
hydrochloric  or  sulphuric  acid. 

Mercuric  cyanide  cannot  be  recoenised  by 
these  tests.  It  yields  cyanogen  when  neated  in 
a  closed  tube,  and  is  decomposed  when  heated 
with  strong  sulphuric  acid. 

Ferroe^mides. 

SQvernUrale,  n^te  precipitate  (Ag4FeCyA  in- 
soluble  hi  nitric  acid  and  sparingly  soluUe  in 
ammonia ;  soluble  in  potassium  cyanide.  Ferric 
chloride^  dark-blue  precipitate  (Fe^(FeCy^)^, 
Ferrous  sulphate^  white  precipitate,  rapidly  be- 
coming blue.  Copper  sulphate^  ohocolate-brown 
precipitate  (Cu,FeCy,),  or  in  very  dilute  solution 
a  brown  colouration. 

Ferrtojwildes. 

Silver  niiraie^  oruige  precipitate  (Ag^FeCya), 
soluble  in  ammonia ;  insoluble  in  nitric  acid.  Fer- 
rous sulphate,  dark-blue  precipitate  (Fej[FeCv,)|), 
insoluble  in  dilute  acids ;  decomposed  by  lUkalis. 
Ferric  chloride,  a  greenish-biown  colouration. 

TWiMtyinatWi 

Silver  niiraie,  white  precipitate  (AgCNS), 
soluble  in  ammonia;  insoluble  in  nitric  acid. 
Ferric  chloride,  Uood-red  colouration,  not 
affected  by  boiling  nor  by  hydrochloric  acid  ;  de- 
colourised by  mercuric  chloride.  Copper  sul- 
phate, a  black  precipitate  chan^g  to  white 
(CU|(CNS)t)  on  standinff  or  addition  of  a  re- 
ducing agent.  Moderatuu  strong  sulphuric  acid 
evolves  carbon  oxysulphiae,  which  bums  to  car- 
bon dioxide  and  sulphur  dioxide.  Cobalt  chloride 
and  the  solution  shaken  up  with  ether  and  amyl 
alcohol,  azure-blue  colouration  (K,Co(GNS)4). 

Cyanates. 

Cobalt  chloride,  in  aqueous  alcoholic  solution, 
blue  soluble  double  salt  (KaCotCNO)^),  decom- 
posed by  excess  of  water. 

Nitrates. 

Sulphuric  acid  evolves  nitric  acid  on  heating ; 
if  metallic  copper  is  added,  red-brown  nitrogen 
oxides  are  given  off. 

The  neutral  solution  is  mixed  with  ferrous 
sulphate,  and  concentrated  sulphuric  acid  is 
poured  down  the  side  of  the  tube  so  as  to  form  a 
layer  at  the  bottom ;  a  dark-brown  ring  is  formed 
»t  the  junction  of  the  two  liquids.    Iodine  and 


bromine  must  be  removed  before  applying  thia 
test,  and  the  liquid  must  be  cold.  Mitrate  in 
presence  of  nitnte:  destroy  nitrite  by  boiling 
acetic  acid  solution  with  urea  or  hydrazine  sul- 
phate ;  then  add  potassium  iodide,  starch,  and 
a  fragment  of  zinc;  then  colouration  denotes 
nitrate. 

Nitrites. 

Silver  nitrate,  a  white  precipitate  in  conoen- 
trated  solutions. 

Mix  the  solution  with  potassium  iodide  and 
starch  and  acidify  with  acetic  add ;  a  deep-blue 
colouration  is  produced,  owing  to  the  libnation 
of  iodine.  Nitrites  heated  with  dilute  adds 
evolve  nitrogen  ox^s.  Metaphenylenediamine 
hydrochloride^  Bismarok  brown  colouration. 

A  dilute  solution  of  ornaphtihylamine  and 
sulphaniHc  acid  addified  with  acetic  add ;  a  red 
colouration  of  azo-  compound  (c/.  Zdtsch. 
angew.  Chem.  1900,  235). 

Dimethylaniline  hydrochloride,  added  to  an 
acidulated  solution  containing  nitrous  acid,  gives 
a  yellow  colour  dependm^  on  the  formation 
of  paranitrosodimethylaniline  (Miller,  Analyst, 
1912,  37,  345). 

Hypoehlorites. 

Silver  nitrate,  a  white  predpitate  of  silver 
chloride.  Lead  nitrate,  a  white  precipitate  be- 
coming orange-red,  finally  brown^  manganous 
salts,  a  brown  predpitate  (MnOs,a;H|0).  Indigo 
solution,  decolourised  even  in  an  alkaline  solution. 

Chlorates. 

Warm  a  small  quantity  of  the  solid  with  con- 
centrated sulphuric  add ;  a  yellow  explodve  gas 
Is  produced  with  detonations. 

Addif^  the  solution  with  sulphuric  acid,  add 
indiffo  solution,  and  then  sulphurous  add  or  a 
sulphite  drop  by  drop ;  the  cdonr  of  the  indigo 
is  atschaiged. 

Perehlorates. 

Concentrated  sulphu/ric  add,  no  explodve  gas. 
Titanous  sulphate,  perehlorates  raduced  to 
chlorides. 

Bromates. 

Silver  nitrate,  white  precipitate,  AgBrO., 
decomposed  by  hot  hydrochloric  acid  with 
evolution  of  bromine.  Barium  chloride,  white 
predpitate  Ba(BrOs)t.  Sulphurous  acid,  bro- 
mineiiberated. 

IcM^tes. 

Silver  nitrate,  white  curdy  predpitate  ( AglOg), 
soluble  in  ammonia;  reduced  to  yellow  silver 
iodide  by  sulphurous  acid.  Banum  chloride, 
white  predpitate  (Ba(IOa),).  Sulphurous  acid, 
iodine  liberated. 

Periodates. 

Silver  nitrate,  yellowish- white,  red,  or  brown 
precipitate  depending  on  the  acidity  Of  Uie 
periodate  solution.  Barium  chloride,  white  pre- 
cipitate. Manganous  sulphate,  red  precipitate 
Mn^HIOc  turning  brown.  Seducing  agents 
(U^0„  Ti,(SO^).,  Zn,  eta)  convert  periodates 
readQy  into  iodides.  Mercuric  nitrate,  orange- 
red  predpitate  5HffO,I.07,  different  from 
iodates,  which  give  white  Hg(IOa),. 

Tartrates. 

Calcium  chloride,  in  excess,  a  white  pre- 
dpitate rCaC^H^Ot),  soluble  in  acids  and  in 
potash  solution.  Complete  precipitation  requires 
time,  and  is  promoted  by  vigorous  agitation. 
Potassium  acetate,  in  presence  of  free  acetic 
acid,  a  white  crystiOline  precipitate  (KHG^H^Oi), 


ANALYSIS. 


243 


forming  alowly  in  dflntfl  solntionB.  Silver  i 
niiraie,  a  white  precipitate,  aolnble  in  nitric  aoid 
or  ammonia.  If  the  washed  precipitate  is  dis- 
■olved  in  the  least  nossible  quantity  of  dilate 
aaimonia»  and  tiie  solution  heated,  the  test-tnbe 
is  coated  with  a  minor  of  metallic  sflyer.  Fer- 
rous mdphatet  followed  by  few  drops  of  hydrogen 
peroxide  and  excess  of  caustic  soda,  bloish-yiolet 
colonration. 

Cttntos. 

OaJciwn  chhride,  or  Ume-uxUer,  in  excess  in 
neutral  solution,  a  white  precipitate, 

(Ca,(C.H,0,).) 
only  on  boiling.  Potaaeium  ealts,  no  precipitate 
Caimiwm  cMoride,  gelatinous  white  precipitate 
(Gd(C«H,0.),),  insoluble  in  hot  water ;  soluble  in 
acetic  acia  (diff.  from  tartrates).  Mercwric 
mlphaie  (5  pwo.),  following  by  potassium  perman- 
ganate, wnite  '  torbidity,  mercuric  acetone- 
dicarboxylate  (halogens  should  be  absent) 
(BenigdsJL 


Cakium  chloride,  no  precipitate  even  on 
boiling,  except  in  strong  solutions ;  precipitate 
in  diKte  solutions  on  adding  alcohoL  Lime 
water,  no  precipitate  even  on  boiling.  Stiver 
nOraie,  white  precipitate  (Ag,C4H405),  which 
becomes  grey  on  boiling,  liad  aceUUe,  white 
preciintate  (PhCfifig),  which  when  washed 
melts  in  boHmg  water. 


'  Barium  chloride,  or  calcium  chloride,  no 
precipitate  except  after  addition  of  alcohol. 
Feme  chloride,  reddish-brown  precipitate 
(Fe,(C4H404),),  soluble  in  acids ;  decomposed  by 
ammonia^ 

BiDioatfls* 

Hydrochloric  acid,  white  crystalline  pre- 
cipitate of  benzoic  add,  sliffh^v  soluble  in 
water.  Ferric  chloride,  a  oun  precipitate 
{V^JPfB.fig)^),  soluble  in  hydrochloric  acid  with 
libmtion  of  benzoio  acid ;  decomposed  by 
ammonia.  ConcentraUd  aviphwric  acid  and 
alcohol  on  heating  produce  ethyl  benzoate,  dis- 
tinctive odour.  Soda  limei  benzoates  heated 
with   this   reagent   are   decomposed,  evolving 


Ferric  chloride,  intense  purple  colour;  not 
affected  by  glycerol ;  interfered  with  by  alkalis, 
dilute  minenii  adds,  tartaric,  citric,  and  oxalic 
adds,  and  certain  other  substances  such  as 
borax,  sodium  phosphate,  ammonium  and  sodium 
acetates.  Siwer  nitrate,  white  predpitate  in 
neutral  solutions.  Bromine  water,  wnite  pre- 
cipitate, which  with  sodium  amalgam  yidds 
pnenoL  Concentrated  evlphuric  acid  and  methyl 
aicohdi  on  heating  give  methyl  salicylate  ('oil 
of  winter-ereen ').  Diaxotieei  aniline  or  euU 
phanilie  aad  giVes  an  orange  azo-  compound. 

AeeUtcf. 

Ferric  chloride,  a  dark-red  colouration,  dis- 
charged on  boilinfff  with  precipitation  of  a  basic 
ferric  acetate.  Also  discharged  by  hydrochlorio 
acid.  Heated  with  aUrong  sulphuric  acid,  acetic 
add  is  evolved.  If  alcohol  is  added,  ethyl 
acetate  is  formed  and  is  recognised  by  the  smell. 

Foimmtes. 

SAver  nitrate,  a  white  precipitate  in  con- 
centrated scdntions ;  the  solution  or  predpitate 
rapidly  becomes  black  (Ag),  especially  on  heat- 
ing.    Ferric  chloride,  a  red  odour,  discharged 


on  boilmg,  with  precipitation  of  basic  fenic 
fbrmate ;  also  disobarged  \iw  hydrochloric  acid. 

A  solid  formate  mixea  with  concentrated 
sulphuric  aoid  gives  off  carbonic  oxide  even  in 
the  cold,  but  no  carbonic  anhydride. 

GaDie  Mid. 

Ferric  chloride,  in  neutral  solutions,  a  bluish- 
black  precipitate  or  colouration.  QdoAin  or 
dOmmin,  no  predpitate.  Potauium  cyanide, 
red  ooloantion,  wnich  disappears  on  stand- 
ing, but  reappears  on  agitation  in  presence  of 
air.  Caustic  soda^  green  colouration  gradually 
darkening,  and  with  excess  beoomin^  brownish- 
red.    Lime  footer,  bluish-grey  precipitate. 

Tumleadd. 

i^erriic  chloride,  bluish-green  or  bluish-black 
predpitate  or  colouration.  O^atin  or  dXbumin, 
yellowish-white  precipitate.  Potassium  cyanide, 
no  colouration.  Caustic  soda,  reddish- brown 
colouration  gradually  darkening.  Lime  water, 
grey  precipitate. 

Phenol. 

Ferric  chloride,  violet  colouration,  destroyed 
by  acids.  Bromine  water,  white  predpitate 
(trilnromophenol  and  tribromophenol  bromide). 
Concentrated  stdphuric  add  and  a  fragment  of 
sodium  nitrite,  on  gently  warming,  greenish  blue 
solution,  turned  rea  when  poured  into  water,  and 
changed  asnin  to  blue  by  caustic  alkali 

PiroguloL 

Silver  nitrate  or  FehUng's  solution,  reaflily 
reduced.  Caustic  alkalis,  brown  solutions,  rapidly 
darkening  owing  to  absorption  of  oxygen.  Form- 
aldehyde and  strong  hydrochloric  add,  white  pre- 
cipitate becoming  red,  and  finally  purple. 

Urle  aeid. 

Alkali  urates  reduce  silver  nitrate,  and  when 
heated  with  solid  caustic  soda,  ammonia  is 
evolved,  and  an  alkali  cyanide  is  produced. 
Nitric  add:  evaporate  solution  to  cuyness  on 
water-bath,  reddish  colouration,  rendered  violet 
W  ammonia,  and  turned  blue  by  eanstic  soda 
(Murexide  test). 

QUAHTITATIVS   AVALTSU. 
QBAYIUETBIO  BflTHODS. 

A  few  metals  are  separated  and  weighed  in  the 
mctaUic  condition,  but  the  majority  of  metallic 
and  addio  radicals  are  weighed  in  the  form  of 
one  or  other  of  their  compounds.  In  order 
that  a  compound  may  be  available  for  the  deter- 
mination ol  one  of  its  constituents,  it  should  be 
of  perfectly  definite  composition  and  not  highly 
hygroscopic  or  otherwise  liable  to  alter ;  it  must 
be  insoluble  in  the  liquid  in  which  it  is  formed,  and 
insoluble  in  an  excess  of  the  reagent ;  it  must  be 
easily  freed  from  impurities,  and  capable  of 
beinff  brought  mto  the  proper  condition  for 
weighing  without  tedious  and  complicated  opera- 
tions. It  is  also  desirable  that  the  compound 
should  contain  only  a  small  proportion  of  the 
constituent  to  be  estimated,  smce  the  effect  of 
the  unavoidable  error  of  experiment  is  thus 
minimised.  An  estimation  of  chlorine  in  the 
form  of  silver  chloride  is  more  accurate  than  an 
estimation  of  silver  in  the  same  way,  since  only 
one-fourth  of  the  error  of  experiment  represents 
chlorine,  whilst  three-fourths  represent  suver. 

A  description  will  first  be  given  of  a  few 
typical  ^gravimetric  methods;  then  an  alph^- 
l)etioal  bst  of  metals  and  acid  radicals,  with  a 
summary  of    methods  available  in  each  case; 


S44 


ANALYSIS. 


followed  by  a  series  of  methods  of  separation  of 
general  applioability.  Special  methods  for  the 
analysis  of  technical  pnxiacts  will  be  found  in 
the  artioles  dealing  with  these  materials. 

Geferal  Methods  of  Estimation. 

I.  As  Sviiphides. 

(a)  With  previous  preeipHaiion  by  hydrogen 
mdphide.  The  solution  should  be  moderately 
dilute  and  distinctly  acidified  with  HO,  but  anV 
large  quantity  of  this  acid  must  be  avoided. 
Nitric  acid  and  nitrates,  which  should  be  absent 
as  far  as  possible,  may  be  removed  by  repeated 
evaporation  wiUi  strong  hydrochloric  acid,  but 
this  treatment  is  not  admissible  if  the  metals 
present  form  volatile  chlorides;  if  present,  a 
much  higher  degree  of  dilution  is  necessary.  In 
most  cases  precipitation  is  accelerated  and  the 
precipitate  rendered  more  granular  by  keeping 
the  liquid  warm.  A  current  of  washed  hydroeen 
sulphide  is  passed  through  the  solution  until  it 
is  thoroughly  saturated,  and  the  flask  is  dosed 
and  left  in  a  warm  place  untO  the  precipitate  has 
settled.  Molybdenum  and  the  metals  of  the 
platinum  group  are  -only  completely  precipi- 
tated after  pnuonged  treatment  with  the  gas. 
The  precipitate  is  protected  from  air  as  far  as 
possible  firing  filtration,  and  the  liquid  used 
for  washing  should  contain  hydrogen  sulphide  in 
order  to  prevent  oxidation. 

When  arsenic  is  present,  Uie  liquid  should 
be  heated  wiUi  pure  sulphurous  acid  to  reduce 
arsenic  acid,  and  the  excess  of  sulphurous  acid 
expelled  before  treatment  with  hydrogen  sul- 
phide. In  presence  of  antimony,  tartaric  acid 
should  be  added  to  prevent  co-precipitation  of 
basic  antimony  chloride. 

When  copper  is  precipitated  as  sulphide  in 
presence  of  sine,  the  copper  sulphide  should  be 
washed  once  or  twice  with  dilute  hydrochloric 
acid  of  sp.gr.  1-05  containing  hydrogen  sulphide, 
and  then  with  water  also  containing  the  gas. 

(/3)  With  previous  precipiUUion  by  ammonium 
sulphide.  Add  to  the  warm  solution  a  consider- 
able quantity  of  ammonium  chloride,  which  is 
found  to  promote  precipitation  and  render  the 
precipitate  more  granular,  then  ammonia  to 
alkalme  reaction,  and  a  slight  excess  of  am- 
monium sulphide.  Close  the  flask  and  allow  to 
stand  in  a  warm  place  until  the  precipitate  has 
settled.  Protect  from  air  as  far  as  possible 
during  filtration,  and  wash  with  water  containing 
ammonium  chloride  and  a  little  ammonium  sul- 
phide or  hydrogen  sulphide. 

The  precipitated  sulphide  is  treated  in  one 
of  two  ways :  it  is  collected  on  a  weighed  filter, 
dried  at  a  definite  temperature  and  weighed ;  or 
heated  with  sulphur  in  a  current  of  hydrogen, 
and  then  weighed. 

In  the  first  case  it  is  essential  to  ensure  the 
absence  of  co-precipitated  sulphur,  and  for  this 
purpose  the  oried  precipitate  is  treated  with 
pure  carbon  disulphide  and  again  dried,  or,  in 
the  case  of  cadmium,  mercury,  or  bismuth,  the 
moist  precipitate  is  treated  with  a  warm  con- 
centrated solution  of  sodium  sulphite,  again 
washed,  and  dried. 

When  the  sulphide  is  stable  at  a  moderately 
high  temperature  and  is  not  reduced  bv  hydrogpen, 
Rose's  method  is  employed.  The  dry  precipi- 
tate \s  separated  from  the  filter,  which  is  then 
burnt,  and  the  precipitate  and  filter  ash  are  in- 


troduced into  a  porcelain  crucible  and  mixed 
with  purs  finely  powdered  sulphur.  The  crucible 
is  provided  with  a  pwforatea  lid,  through  which 
passes  a  porcelain  tube  connected  with  a  hydro- 
ffcp  apparatus.  A  current  of  purified  and  dried 
nydrogen  ts  passed  into  the  crucible,  which  is 
gradually  heated  to  full  redness  until  excess  of 
sulphur  is  expdled,  allowed  to  cool  in  a  ounent 
of  nydrogen,  and  weighed. 

Non-volatile  sulphides  may  be  collected  in  a 
wide  Soxhlct  tube  and  dried  in  sitm  over  a  ring 
burner  at  300*,  while  a  current  of  pure  dzy 
carbon  dioxide  is  conducted  through  the  tube. 
This  treatment  removes  both  moisture  and 
co-precipitated  sulphur  (Cahen  and  Morgan, 
Analyst,  1909,  34,  3). 

IL  As  Oxide. 

{a)  With  previous  precipiiaiion  as  hydroxide. 
The  solution  is  mixed  with  ammonium  chloride, 
heated  to  boiling,  and  ammonia  added  in  slidit 
excess.  A  large  excess  of  ammonia  will  partially 
redissolve  some  of  theprecipitate,  and  must  be 
expelled  by  boiling.  The  precipitate  is  washed 
with  hot  water. 

If  ammonia  is  inadmissible,  pure  caustic 
potash  or  soda  is  used  as  the  precipitant  Excess 
of  alkali  must  be  avoided,  and  the  precipitate 
must  be  very  thoroughly  washed,  smce  small 
quantities  of  alkali  are  somewhat  firmly  retained. 

In  both  cases  it  is  better  to  precipitate  in  a 
porcelain  or  platinum  vessel  than  in  glass. 

Non-volatile  carbon  compounds,  such  as 
sugar,  glycerol,  alkaline,  tartrates,  and  citrates* 
Ac,  more  or  less  completely  prevent  precii»tation 
of  hydroxideB  by  ammonia  or  oaustio  potash,  or 
soda,  and  hence  must  first  be  removea  by  calci- 
nation. Moderately  strong  nitric  acid  attacks 
filter  paper,  forming  soluble  products,  which 
prevent  tne  precipitation  of  metallic  hydroxides. 

(/3)  WUh  prevtous  predpHation  as  earbonaie. 
The  solution  is  nearer  neutralised,  heated  to 
boiling,  and  mixed  with  a  slight  excess  of  sodium 
carbonate,  boiling  being  continued  until  all 
carbon  dioxide  is  expelleid.  The  precipitate  is 
washed  with  hot  water.  Ammonium  carbonate 
can  be  used  in  some  cases,  and  has  the  advantage 
of  not  introducing  a  fixed  alkali  In  these  cases 
the  precipitate  would  be  washed  with  water 
containing  a  little  ammonia  and  ammonium 
carbonate. 

The  precipitated  hydroxide  or  carbonate  is 
placed  in  a  crucible  (with  pcevious  separation 
from  the  filter  paper  if  the  metal  is  easflv  re- 
ducible), and  is  gradually  heated  to  full  redness, 
care  being  taken  that  no  reduciii^  gases  from  the 
fiame  enter  the  crucible.  Oxi<Ms  of  reducible 
metals  must  be  heated  in  a  porcelain  crucible, 
but  in  other  oases  a  platinum  crucible  may  be 
used  with  advantage.  If  carbonates  (or  oxalates) 
are  being  converted  into  oxides,  it  is  important 
to  secure  a  circulation  of  air  in  order  to  remove 
carbon  monoxide  and  carbon  dioxide  as  fast  as 
they  are  given  off,  and  thus  accelerate  decom- 
position. This  is  done  by  inolininff  the  crucibto 
and  placing  the  lid  across  the  mouth  in  a  slantmg 
position. 

IIL  As  reduced  Metals, 

(a)  In  some  cases  the  metal  is  precipitated 
as  oxide,  which  is  then  dried  and  heated  in 
hydrogen  as  in  Rose's  method  for  sulphides,  the 
redue^  metal  being  cooled  in  hydrogen  and 
weighed.    This  method   is  especially   valuable 


ANALYSIS. 


245 


wliflii,  as  in  the  case  of  cobalt,  the  oxide  obsti- 
nately letaina  small  quaatitiei  of  alkali,  which. 
however,  can  readily  be  removed  from  the  reduced 
metal  W  washing  with  water. 

(3)  The  other  method  is  to  mix  the  oxide, 
earbonate,  Ac,  with  five  or  six  times  its  weight 
of  <iidinaiy  potassiam  cyanide,  and  heat  in  a 
tapacioiis  porcelain  omcible,  at  first  cautiously 
ana  afterwarda  to  oomplete  fusion.  When  re- 
duction is  complete,  the  crucible  is  allowed  to 
eool,  and  is  tapped  occasionally  to  promote  the 
ooUection  ol  the  reduced  metal  in  a  single  button. 
llie  cyanide  is  removed  by  treatment  with  water, 
the  metal  washed,  dried,  and  weighed.  Care 
should  be  taken  that  the  metallic  button  does 
not  contain  small  fragments  of  porpelain  result- 
ing from  the  corrosion  of  the  crucible. 

IV.  As  Sulphale. 

Barium,  strontium,  and  lead  are  precipitated 
horn  solutions  in  the  ordinary  way,  but  other 
metala  are  converted  into  sulphate  by  treatment 
with  the  strong  acid,  the  method  being  only 
available  when  a  single  metal  is  present  in  com-  • 
bination  with  a  volatile  acid.  The  highly  con- 
centrated solution,  or  better,  the  solid  substance, 
is  mixed  cautiously  with  concentrated  sulphuric 
aeid  in  a  platinum  crucible  and  then  gently 
heated  to  expel  excess  of  acid,  the  crucible  being 
inclined  and  the  lid  placed  in  a  slanting^  position 
across  its  mouth.  A  large  excess  of  acid  should 
be  avoided,  and  caie  must  be  taken  that  the 
temperature  is  sufficient  to  expel  the  excess  of 
free  acid  but  not  sufficient  to  decompose  the 
snli^iate.  Sulphates  of  the  alkalis  and  alkaline 
eatthfl  may  be  heated  to  redness.  Bismuth 
sulphate  and  zinc  sulphate  decomx>oee  if  heated 
above  400^ ;  magnesram  sulphate  is  not  decom- 
posed at  450^,  nor  barium  or  lead  sulphate  at 
600*  (G.  H.  Bailey).  A  temperature  of  about 
350*  is  required  to  expel  the  last  traces  of  free 
snlphorio  acid.  With  lead  or  bismuth  sulphate 
a  porcelain  vessel  must  be  used. 

Geayimxtbic  DsmtxiKATiOK  OF  Metals 

AHD  AOXD  RaDICALB. 

Details  of  operations  will  be  found  under 
GtJieral  Meihoda  of  SgHmation,  and  electrolytic 
and  volumetric  methods  will  be  indicated  under 
appropriate  headings. 

Ahnntnhmt# 

(a)  As  oxide,  with  previous  precipitation  with 
anuDoiiium  sulphide,  ammonium  carbonate,  or 
as  basic  acetate  (v.  Methods  of  separaiion),  the 
aluminium  hydroxide  is  maintained  in  its  in- 
aolnble  hydrc^l  form  by  washing  with  dilute 
aqueous  aounonium  nitrate.  T&  hydroxide 
m*y  also  be  precipitated  in  a  form  suitable  for 
filiratjon  by  boiling  the  solution  of  the  aluminium 
salt  with  potassium  iodide  and  potassium  iodate 
(Stock,  Ber.  1900,  33,  G48 ;  Compt.  rend.  1900, 
130,  175);  or  with  bromine  water  (Jakob, 
Zeitseh.  anal.  Chem.  1913,  52,  651),  when  the 
precipitate  is  compact  and  not  gelatinous. 

(6)  Ab  fhospiate.  The  sohition  is  nearly 
nnitralised,  mixed  with  sodium  acetate  and  a 
sDiall  quantity  of  acetic  add,  heated  to  boiling, 
■odiam  phosphate  added  in  excess,  and  the  pre- 
cipitsta  washed  with  hot  water,  heated,  and 
w«Uiad  as  afamirrinm  phosphate  (A1P0«). 

iUBBOOIQlD* 

(«)  As  plaUniehhnde  (NHJ,Pta«  (v.  Potas- 
-'"-ii.    The  platinie  chloride  solution  should 


be  added  before  the  liquid  is  heated,  and  evapo- 
ration should  not  quite  be  carried  to  complete 
dryness. 

(6)  By  distillation  {v.  Acidiaustby). 

Antimony. 

(a)  As  sulphide  Sh^S^.  The  precipitate  is 
collected  (i.)  in  a  weighed  Soxhlet  tube  on 
an  asbestos  mat,  and  dried  at  280°>'300°  in  a 
current  of  carbon  dioxide  (Analyst,  1909,  34,  3) ; 
or  (iL)  in  a  Gooch  crucible  and  dried  in  an  air- 
oven  in  an  atmosphere  of  carbon  dioxide.  An 
aUquot  part  is  then  placed  in  a  porcelain  boat, 
and  heated  in  a  glass  tube  in  a  current  of  dry 
carbon  dioxide  until  it  becomes  black,  and 
all  admixed  sulphur  is  expelled.  The  loss  of 
weight  is  calculated  to  the  whole  quantity  and 
deducted  from  the  weight  at  lOO**. 

(6)  As  oxide  Sb^O^,  with  previous  precipi- 
tation as  sulphide.  The  sulphide  is  placed  in  a 
porcelain  crucible  and  treated  with  fuming  nitric 
acid  boiling  at  86^  until  completely  oxidiwd,  the 
excess  of  acid  expelled,  and!^the  residue  heated 
with  partial  exposure  to  air  until  the  weieht  is 
constant.  The  sulphide  may  also  be  mixeof  with 
30  to  50  times  its  weight  of  precipitated  mer- 
curic oxide  and  heated  cautiously  until  of  con- 
stant we^;ht.  A  deep  capacious  crucible  with 
a  lid  having  a  side  tube  for  the  exit  of  vapours 
has  been  devised  for  this  and  similar  estimations. 

For  a  method  of  estimating  small  quantities 
of  antimony,  as  in  urine,  see  Schidrowitz  and 
Goldsbrough  (Analyst,  1911,  36,  101);  Beam 
and  Fieak  (idem.  1919,  44,  196). 

Arssnle. 

(a)  As  trisulphide  As^Sg,  which'  is  dried  at 
100^.  The  dry  precipitate  should  volatilise 
completely  when  heated. 

(6)  As  penUuulphide  As^Ss-  The  arsenic  is 
oxidised  to  arsenic  acid  by  chlorine  in  alkaline 
solution,  and  the  precipitation  then  effected  in 
warm  acid  solution  after  decomposing  all  the 
chlorate  (Brauner  and  Tomicek,  Monatsh.  1887, 
8,  642 ;  and  Neher,  Zeitseh.  anal.  Chem.  1893, 
32,  45). 

(c)  Arsenic  acid  is  estimated  as  magnesium 
puroarsenate  Mg,As,07,  in  the  same  way  as 
phosphoric  acid  {which  see).  The  filter  pa|)er  is 
moistened  with  a  solution  of  ammonium  mtrate 
and  dried  before  burning,  in  order  to  prevent 
reduction  {v.  Ducru,  Oompt.  rend.  1900,  131, 
886 ;  cf,  cUso  Friedheim  and  Michaelis,  Zeitseh. 
anal.  Chem.  1895,  34,  505). 

Or  the  ammonium  magnesium  arsenate  pre- 
cipitate eSteT  washing  with  dilute  ammonia,  tnen 
with  alcohol  to  remove  free  ammonia,  is  titrated 
with  N/2-acid,  using  methyl-orange  as  indicator. 
Each  0.0.  of  N/2-acid  is  equivalent  to  0*01875 
gram  of  arsenic. 

Barium. 

(a)  As  stdphaie  BaSOf,  by  precipitation  with 
sulphuric  acid  (v.  Sulphuric  actd), 

(b)  As  carbonaU  BaCO,,  which  may  be 
dried  at  a  temperature  below  dull  redness  after 
moistening  the  filter  ash  with  ammonium  car- 
bonate (v.  General  Methods  of  Estimation), 

(e)  As  silieofluoride  {v.  Methods  of  Separa- 
iion), 

(d)  As  bromide  (Thome,  Zeitseh.  anal.  Chem. 
1905,  43,  308). 

Biflnuth. 

(a)  As  oxide  Bi,0„  after  precipitation  with  a 
slight  excess  of  ammonium  carbonate.    In  pre- 


246 


ANALYSIS. 


aence  of  chlorides  or  sulphates  the  pieoipitate 
wiU  contain  basic  chlorick  or  sulphate,  and  in 
this  (or  in  any  other)  case  the  bismuth  may  be 
precipitated  as  sulphide,  which  is  oxidised  in 
the  crucible  by  fuming  nitric  add  boiling  at  86°, 
and  then  heated. 

(6)  As  sulphide  Bi,Ss,  which  is  dried  at  100° 
and  weighed  at  intervals  of  20-30  minutes.  The 
weight  first  decreases  owing  to  loss  of  water, 
and  then  increases  owing  to  oxidation ;  the 
minimum  weight  is  taken  as  correct. 

(c)  As  metallic  biamuih.  Bismuth  is  pre- 
cipitated as  metal  by  adding  to  slightly  acid 
solutions  of  its  salts,  formaldehyde  and  excess  of 
caustic  soda,  boiling  and  filtering  through  a 
Qooch  omcible,  the  precipitate  being  wMhed 
witii  alcohol  and  dried  at  106°  (Vanino  and 
Treubert,  Ber.  1898,  31,  1303). 

{d)  Other  meUiods  :  phoaphate  (Stabler  and 
Scharfenbeig,  Ber.  1906,  38,  3862),  double  moly- 
hdaU  (Bi(NH«)  (M0O4),  (Miller  and  Cruser,  J. 
Amer.  Ghem.  Soc.  1906,  27,  16) ;  and  benzildi- 
oxime  (Ataok)  (c/.  Strebinger,  Chem.  Zeit. 
1918,  42,  242). 

CSadnitiim. 

(a)  As  stride  CdS,  which  is  dried  at  100°, 
or  dissolved  in  hydrochloric  add,  and  the  solu- 
tion evaporated  to  dryness  with  sulphuric  add, 
the  residue  gently  ignited  and  weighed  as  CkilS04. 

(6)  As  oxide,  after  precipitating  as  basic  car- 
bonate from  boiling  solutions  by  potassium  (not 
sodium)  carbonate  and  collecting  in  a  Gooch 
crucible  (Amer.  J.  ScL  1906,  20,  466). 

Galdum. 

(a)  As  oxide  CaO,  after  predpitation  with 
ammonium  carbonate  or  ammonium  oxalate 
(v.  Utz,  Oest.  Chem.  Zeit.  1904,  7,  610).  In  the 
latter  case  tiie  solution  is  made  alkaline  with 
ammonia,  heated  to  boiling,  and  mixed  with 
excess  of  ammonium  oxalates  The  predpitate 
is  washed  with  hot  water,  and  strongly  heated 
until  its  weight  is  constant. 

(6)  As'  9ul]^uUe  CaS04,  by  igniting  the  car- 
bonate or  oxalate  with  pure  sulphuric  add; 
or  bv  heating  it  with  a  mixture  of  ammmonium 
sulphate  and  chloride  (Willis  and  Macintire, 
Analyst,  1918,  102). 

Gerinm.  F.  Brinton  and  James,  J.  Amer. 
Chem.  Soc  1919,  41,  1080. 

Ghromlnm  (in  chromic  salts). 

(a)  As  oxide  Cr,0„  after  predpitation  by 
ammonia,  or  better,  ammonium  sulphide ;  or  by 
potassium  iodide  and  iodate  (Stock  and  Massadu, 
Ber.  1901,  84,  467).  When  predpitated  as 
chromic  hydroxide  and  weighed  after  ignition 
as  chromic  oxida^  care  should  be  taken  to  avoid 
oxidation.  Ignition  in  a  Rose  crucible  in  a 
current  of  hyoroffen  gives  exact  results. 

(6)  As  pnosjMoie,  in  the  same  way  as  alu- 
minium. 

Chromium  (in  chromic  acid  and  chromates). 

(a)  As  oxide  Cr,0,.  The  solution  is  neutral- 
ised, heated  to  boilmg,  and  mixed  with  excess  of 
a  neutral  solution  of  merourous  nitrate  free  from 
nitrous  acid.  The  predpitate  is  washed  with  hot 
water  containing  merourous  nitrate,  and  heated 
to  redness  in  a  porcelain  orudble  until  all  mer- 
curial vapours  are  expelled.  The  merourous 
chromate  yidds  chromic  oxide. 

(b)  As  chromate,  by  precipitation  with  barium 
rhloride  in  acetic  acid  solution  (c/.  Winkler, 
Zdtsoh.  angew.  Chem.  1918,  31,  46). 


Cobalt. 

(a)  As  metallic  cobalt,  after  precipitation  as 
cobaltio  hydroxide  by  caustic  soda  or  potash 
with  bromine.  The  solution  must  be  free  from 
ammonium  salts,  or  all  ammonia  must  be 
expelled  by  boiling.  The  predpitate  retains 
traces  of  aUuJi,  anain  flk^urate  estimations  the 
reduced  metal  should  be  washed  with  water, 
dried,  and  again  heated  in  hydrogen. 

(6)  As  sulphate  C0SO4,  alter  predpitation  as 
sulphide,  which  is  treated  with  nitric  acid  and 
thai  with  sulphuric  add.  If  the  heated  sulphate 
is  at  all  black,  it  must  be  treated  again  with 
sulphuric  add. 

Copper. 

(a)  As  cwprous  sulphide  Cu^S,  using  Rose's 
method,  with  previous  predpitation  as  cuprio 
sulphide  by  hydrogen  smphiae  or  sodium  thio- 
sulphate  (Chem.  Zdt.  1896,  19,  1691). 

(6)  As  oxide,  after  predpitation  by  caustio 
potash  or  soda  in  absence  of  ammonium  salts. 

(c)  As  cuprous  ihiocyanaU  CuCNS  (Rivot, 
Compt.  rend.  1864,  38,  868  ;  also  Amer.  J.  Sci. 
1902,  13,  20  and  138).  The  warm  solution, 
which  must  contain  no  free  nitric  add,  is  slightiy 
addified  with  hydrochloric  add,  and  mixed 
gradually  with  an  excess  of  a  moderatdy  strong 
solution  of  equal  parts  of  ammonium  or  potas- 
sium thio^anate  and  ammonium  hyorogen 
sulphite.  When  cold,  the  precipitate  is  ooUeoted 
in  a  weighed  Qooch  crudSle,  washed  with  cold 
water  and  20  p.o.  alcohol,  and  dried  at  110°-120°. 
The  predpitate  may  also  be  converted  into 
cuprous  sulphide  by  Rose's  method.  Cuprous 
thioqyanate  ib  not  quite  insoluble,  especially  in 
presence  of  much  free  acid. 

Copper  salts  are  reduced  by  hypophoephoruus 
acid,  or  alkaline  hypophosphites  on  wanning, 
and  the  reduced  copper  may  be  washed,  dried, 
and  weighed  (Dallimore,  Windisch). 

Gluefiiuii. 

As  oxide  GIO,  with  previous  predpitation  in 
the  cold  by  slight  excess  of  ammonia  or  ammo- 
nium sulphide  m  presence  of  ammonium  chloride, 
but  not  caustio  soda  or  potash,  or  ammonium 
carbonate.  The  basic  acetate  of  gludnum 
rQ104(CH,(X)a).]  is  readily  soluble  in  chloro- 
form, and  can  bo  distilled  unchanged. 

QoU. 

As  metaUic  gold,  Nitrio  acid  is  removed 
by  evaporation  witii  hydrochlorio  add.  The 
solution  is  acidified  with  hydrochloric  add, 
mixed  with  a  large  excess  of  ferrous  sulphate 
solution,  and  heated  gentiy  for  a  few  hours ;  or 
it  is  acidified  with  sulphuric  acid,  mixed  with 
oxalic  acid,  and  allowed  to  stand  in  a  warm  place 
for  several  hours.  Formaldehyde  and  hydrogen 
peroxide  in  alkaline  solution  can  be  used  as  pre- 
oipitants  (Ber  1899,  32,  1968).  Nitrous  acid  is 
also  suggested  (Jameson,  J.  Amer.  Ghem.  Soc 
1906,  27,  1444).  The  preoipiUte  is  collected  on 
a  weighed  filter,  washed  and  dried. 

Iron. 

(a)  As  ferric  oxide  Fe,Oa,  after  predpitation 
by  ammonia,  eaustio  potash  or  soda,  potasdum 
iodide  and  iodate  (0.  Chromium),  or  as  basic 
carbonate,  basic  acetate  or  formate.  The  oxide 
is  heated  to  redness  until  its  weight  is  constant ; 
if  heated  at  a  higher  temperature,  it  is  partially 
oonvttted  into  ferroso-ferrio  oxide  ¥efi^* 

(b)  Ferrous  and  ferrio  salts  oan  be  separated 
and   estimated   gravimetrically    by    means   of 


ANALYSIS. 


147 


tarimn  carbonate  ami  — iiBcniwin  chloride,  when 
the  ferrio  ait  is  deoompoaed,  precipitatiii^  fenio 
hydioxide»  and  the   fcRoaa  nit 


(a)  Ab  nJpkaU  FhBO^.  The  aoiiition,  which 
ihoold  not  be  dihite^  is  mixed  with  dilute  sal- 
phmio  acid  and  twice  its  votame  of  alcohol,  and 
allowed  to  stand,  and  the  predpitate  washed 
with  alcohoL  If  the  addition  of  alcohol  is  in- 
admisBible,  the  motion  is  evaporated  with  a 
kfge  ezoesB  of  dilate  solphario  acid,  till  fames 
are  evolTed.  The  fesidoe  is  taken  an  with  cold 
water  and  qoiddy  filtered  on  a  Goo(»i  oraciUe ; 
and  the  precipitate  is  washed  with  dilate  sol- 
phoxio  acid  and  afterwards  with  akohol  to 
remoTO  all  free  add. 

(6)  As  9Mipkide  Pb8»  by  hydrogen  sulphide  i 
and  Rose's  method. 

(c)  As  caeide  FbO,  after  precipitation  by 
ammoniam  carbonate,  avoidmg  an  excess  of 
ammonium  salts. 

(<f)  Asmctol. 

(e)  Other  methods.    As  ekromaU  and  todaU. 


(a)  Aapipropho§phaUMg^Vfir  Hie  solution 
is  mixed  with  ammonium  chloride  in  sufficient 
quantity  to  prevent  precipitation  by  ammonia, 
made  stiongly  slkamie  with  ammonia,  and 
then  mixed  with  excess  of  sodium  phosphate,  or, 
better,  ammonium  phosphate  or  miorocosmic 
salt.  Oare  should  be  taken  to  avoid  nibbing  or 
icratchinft  the  sides  of  the  vesseL  The  liquid 
is  allowed  to  remain  for  a  few  hours,  filtered,  and 
the  precipitate  washed  with  a  mixture  €d  strong 
ammonia  (1  part)  and  water  (6  parts)  until  the 
washingp  give  only  a  faint  opalescence  with 
silver  nitrate  after  acidifying  with  nitric  acid. 
The  precipitation  of  the  double  phosphate  is 
greatly  accderated  and  a  granular  non-adherent 
product  obtained  by  shaking  the  mixed  solutions 
m  a  stoppered  cylinder.  The  precipitate  is 
dried,  eauHoualy  heated  in  a  platinum  crucible 
until  all  ammonia  is  expelled,  and  then  boated 
to  redness  until  the  weight  is  constant.  If  the 
precipitate  is  black,  owing  to  partial  reduction. 
It  is  moistened  with  a  few  drops  of  strong  nitric 
acid,  and  again  heated  until  i>erfectly  white. 

Qt)  As  oxide  MgO,  after  precipitation  as 
hydroxide  by  barium  hydroxide,  or  mercuric 
oxkle,  or  as  double  carbonate  Mg(X)3(NH4),COs 
(Zeitsch.  anorg.  Chem.  1908,  58,  427),  the  pre- 
cipitate  being  strongly  ignited  (v.  Zeitsoh.  anorg. 
Chem.  1901,  26,  347). 

(c)  As  puroarsenate  (v,  PfrophoaphaU^  and 
Amer.  J.  8cl  1907,  23,  293). 


(a)  As  sulMiide  MnS,  by  Rose's  method  after 
precipitation  oy  ammonium  sulphide. 

(o)  As  oxide  Jdnfi^  after  precipitation  by 
sodium  carbonate,  or  ammonium  carbonate 
(Tamm,  Zeitsoh.  anaL  Chem.  1872, 1 1, 425).  The 
hydrated  peroxide  precipitated  by  bromine  and 
ammonia,  on  prolonged  ignition  yields  Mn304. 

(c)  As  pwrophotphaU  Mn.P|Oy.  Ammonium 
chloride  and  miorocosmic  salt  are  added  in  oon- 
siderable  excess  to  the  cold  manganese  solution 
followed  by  a  slight  excess  of  ammonia.  The 
mixture  is  then  heated  tiU  the  precipitate  be- 
comes silky  and  crystalline.  After  cooling  for 
30  minutes,  the  precipitate  is  collected  on  the 
Gooch,  washed  with  very  dilute  ammonia,  and 


,  ignited  .Gooch  and  Austin,  Amer.  J.  Sci.  1S9S, 
6.  150), 

id)  As  efdpMak  (Gooeh  aiKl  Austin,  Amer.  J. 
8ci  1898,5,  209). 

Wmmif  {m  meroaioas  oompoonds). 

As  tmertmnme  eUoride  Bg^O^,  The  dilate 
cold  solution  is  mixed  with  a  solution  of  sodium 
chloride  in  sUght  excess,  and  the  precipitate  is 
collected  on  a  weighed  filter  and  dried  at  100*. 

Mamiiy  (in  mercuric  compounds). 

(a)  As  eulpkide  HgS,  whidi  is  dried  at  lOO^" 
after  precipitation  by  hydrogen  sulphide. 

fb)  As  mercwrmu  eUonde  Hg,ay.  The  solu- 
tion IS  mixed  with  excess  of  hydrochloric  acid 
and  phosphorous  acid  (made  by  allowing  phos- 
phorus to  oxidise  slowly  in  moist  air),  and  allowed 
to  remain  in  a  warm  place  for  twelve  hours.  The 
nrp  cipitate  is  collected  on  a  weighed  filter  and 
dried  at  100°. 

For  the  estimation  of  meroury  as  metal  by 
the  dry  method,  see  Cumming  and  Macleod 
(Chem.  Soa  Trans.  1913,  103,  613).  For  iU 
reduction  by  zinc  filings,  see  I^ancois  (Ck>mpt. 
rend.  1918,  160,  960 ;  Chem.  Soc  Abst.  1918, 
iL276). 

Molybdeniim. 

(a)  As  lead  mdybdcde  PbMoO^.  The  solu- 
tion is  heated  to  boilinff,  mixed  with  excess  of 
lead  acetate,  and  boiled  for  a  few  minutes.  The 
precipitate  is  washed  with  hot  water,  dried  at 
100®,  and  heated  to  low  redness  in  a  porcelain 
crucible. 

(6)  As  the  oxide  MoO,.  The  solution  is 
neutralised  with  nitric  acid,  mixed  with  excess 
of  a  neutral  solution  of  mercurous  nitrate,  the 
precipitate  washed  with  mercurous  nitrate  solu- 
tion, dried,  and  heated  until  the  weight  is  con- 
stant. ^  The  metal  is  precipitated  as  sulphide 
either  in  acid  solution,  or  an  ammoniacal  solution 
is  saturated  with  hydrogen  sulphide  and  then 
acidified.  The  precipitate,  collected  in  a  GooCh 
crucible,  is  roasted  to  oxide.  The  temperature 
during  ignition  should  not  exceed  425**.  The 
conversion  of  the  sulphide  into  trioxide  is  com- 
plete at  400® ;  no  further  change  takes  place 
between  400®  and  460®,  but  above  460^  the 
trioxide  sublimes.  The  correct  temperature 
(400®-425®)  is  most  readily  attained  by  using 
an  electric  furnace  (Wolf,  l^tsch.  angew.  Chem. 
1918,  31,  i.  140).  Molybdenite  is  roasted  to 
form  trioxide ;  this  is  extracted  with  ammonia, 
and  the  filtrate  evaporated  and  residue  ignited 
(Analyst,  1906,  31,  312). 

Nickel. 

(a)  As  oxide  NiO,  after  precipitation  as 
nickelic  hydroxide  (Ni(OH),)  by  caustic  potash  or 
soda  with  the  addition  of  bromine  in  absence 
of  ammonium  salts ;  or  after  precipitation  by 
ammonium  sulphide  thorouffhlv  saturated  with 
hydrogen  sulpnide,  the  niokel  sulphide  being 
dissolved  m  aqua  reeia  and  the  solution  preci- 
pitated by  caustic  soaa  or  potash. 

(6)  As  dimdhylglyoximate 

CH,0 :  NO-Ni-NO  :  CCH, 


[,-C: 


I 


CH,C :  NOH      NOH  :  CCH, 

(Ni  =  20'31  P.O.).  A  1  p.c.  alcoholic  solution 
of  dimethylglyoxime  (J.  pr.  Chem.  1908,  77,  44) 
is  added  to  a  hot  dilute  hydrochloric  acid  solution 
of  nickel  followed  by  ammonia  in  slight  cxccms. 
The  red  precipitate,  after  standing  for  about  an 


248 


ANALYSIS. 


hour,  is  collected  on  a  Gooch  crucible,  washed 
with  hot  water  and  dried  at  110''-120''  (Brunck, 
Zeitsch.  angew.  Chem.  1907,  20,  834;  ibid. 
1914,  27,  3r6). 

(c)  Ajb  niekd  dicyanodiamidine  "SiCSfifiJ^).. 
Dicyanodiamidine  sulphate  and  oaustio  alkali 
are  added  to  an  ammoniaoal  solution  of  nickel 
salt,  the  yellow  precipitate  collected  and  dried 
at  1 16^.  If  cobalt  is  present,  hydrogen  peroxide 
is  first  added  to  tne  ammoniacal  solution. 
Aluminium  and  iron  are  kept  in  solution  by 
means  of  tartaric  acid  (Orossmann  and  Schiick, 
Chem.  Zeit.  1907,  31,  335,  911). 

{d)  Small  quantities  of  nickel  may  con- 
veniently be  estimated  by  means  of  a-benzildi- 
oxime.  For  details,  see  Atack  (Analyst,  1913, 
318).  The  method  is  available  in  presence  of 
cobalt,  iron,  manganese,  zinc,  magnesium,  and 
chromium  {cf.  Strebinger,  Analyst,  1918,  361). 
Plattniim. 

As  metal.  The  solution  of  platinic  chloride 
free  from  excess  of  acid  is  precipitated  by  am- 
monia, or,  better,  potassium  chloride  {v.  Foiaa- 
stum),  and  the  precipitate  is  filtered  by  Goooh's 
method  or  through  a  plug  of  thoroughly  dried 
asbestos  contained  in  a  weighed  tube.  The 
precipitate  is  dried,  heated  to  redness  in  a 
current  of  hydrogen,  washed  with  water  to 
remove  alkaune  chloride,  again  dried,  and 
weighed.  The  metal  is  also  precipitated  by 
reducing  agents  {e.ff.  formic  acid,  alcohol  in 
alkaline  solution) ;  and  by  metals  such  as  mag- 
nesium or  zinc  (Chem.  Zeit.  1906,  29,  293). 

Potaaslmn. 
.    (a)  As  platinichhride  K,PtClc.    The   solu- 
tion, which  must  contain  the  potassium  in  the 
form  of  chloride  and  be  free  from  add,  is  mixed 
with  excess  of  platinio  chloride  and  evaporated 
to  dryness  on  the  water-bath.    The  crystalline 
residue  is  washed  with  strong  alcohol,  without 
breaking  the  crystals,  until  the  washings  (which 
at  first  must  be  orange,  showing  the  presence  of 
excess  of  pUtinum)  are  colourless.    The  pre- 
cipitate is  left  in  the  evaporating  dish,  and  the 
washings  are  poured  through  a  small  filter. 
When  washing  is  complete,  the  precipitate  is 
transferred  to  a  weighed  porcelain  crucible  by 
means  of  a  jet  of  alcohol  from  a  wash- bottle,  and 
the  alcohol  is  decanted  off  through  the  filter. 
The  precipitate  in  the  crucible  is  dried  first  at 
70^  tm  most  of  the  alcohol  is  expelled,  and  then 
at  100°  for  half  an  hour.    The  filter  is  dried, 
and  any  precipitate  is  detached  from  the  paper 
as  far  as  possible  and  added  to  the  contents  of 
the  crucible,  which  is  then  weighed.    The  filter 
is  burnt,  and  the  ash  allowed  to  fall  into  the 
crucible,  which  is  again  weighed.    The  increase 
in  weight  is  filter  ash  and  metallic  platinum. 
The   amount  of  platinichloride   corresponding 
with  the  latter  is  calculated  and  addea  to  the 
weight  of  the  precipitate  (v.  J.  Amer.  Chem. 
Soo.  1895,  17,  453 ;   and  Zeitsch.  anal.  Chem. 
1906,  45,  315;    Chem.   Zeit.   1906,   30,   684). 
Or   the  precipitate  of  platinichloride  ii  col- 
lected, washea  with  alcohol-ether  water  mixture, 
then  dissolved  in  boiling  water,  and  the  solution 
boiled  with  an  excess  of  sodium  formate ;  after 
a  few  minutes  hydrochloric  acid  is  added,  the 
heating  continued  until  the  reduced  platinum 
has  flocculated,  when  the  platinum  ii  collected, 
washed,  ignited,  and  weighed  (Steel,  Analyst, 
1918,  43,  348). 


(6)  As  perehlorate  KCIO^.  The  solution 
containing  potassium  and  sodium  as  chlorides 
is  evaporated  down  with  excess  of  dilute  per- 
chloric add  until  all  the  hydrogen  chloride  is 
expeUed.  The  residue  is  taken  up  with  alcohol, 
the  precipitate  collected  on  a  Gooch  crudble, 
washed  with  alcohol,  and  dried  at  130°  (Amer. 
J.  Sci.  1897,  2,  263 ;  cf.  Davis,  Analyst,  1913, 
38,  47  ;  Thin  and  Cumming,  Tnns.  Chem.  Soc. 
1915,  107,  361 ;  Baxter  and  Kobayashi,  J. 
Amer.  Chem.  Soc.  1917,  39,  219;  Gooch  and 
Blake,  Amer.  J.  Sd.  1917,  44). 

As  ccbaUinitriU.  The  solution  is  evaporated 
and  the  reddue  mixed  with  3  c.c.  of  a  50  p.c. 
cobaltous  chloride  solution  and  3  co.  (^  a  60 
p.o.  sodium  nitrite  solution,  and,  after  stirring, 
mixed  with  2  c.c.  60  p.c.  acetic  add.  After 
standing  the  precipitate  Ib  collected  on  a  filter, 
washed,  and  treated  in  a  beaker  with  excess  of 
N/60  potasmum  permanganate,  warmed,  15  c.c. 
sulphuric  add  (1:1)  acraed,  and  the  excess  of 

Permanganate  titrated  with  oxalic  acid  solutioin. 
he  precipitate  has  the  formula  K,CoNa(NOt)c 
and  according  to  theory,  1  c.c.  of  N/50  per- 
manganate s  0*000156  gram  K,0  ;  experiment 
shows  a  better  factor  is  0000172  (Van  der 
Horn  van  der  Bos,  Analyst,  1913,  294;  cf. 
Mitscherlich  and  Fischer,  Analyst,  1912,  37, 
588 ;  Haff  and  Schwartz,  Analyst,  1917,  372). 
Bennett  (Analyst,  1916,  165)  combines  the  two 
methods  by  separating  the  potasdum  as  the 
cobaltinitrite  and  weigning  it  as  perchlofate. 
S6l«Dliim. 

As  selenium.  The  solution  is  strongly  acidi- 
fied with  hydrochloric  acid,  mixed  with  excess 
of  sulphurous  acid  or  sodium  hydrogen  sul- 

?hite,  and  boiled  for  about  fifteen  minutes, 
he  precipitate  is  collected  on  a  weiffhed  filter 
and  dried  at  a  temperature  below  IW.  Solu- 
tions of  selenium  containing  hydroohlorio  add 
cannot  safely  be  concentrated  by  evaporation 
excei>t  in  presence  of  a  laive  quantity  of  alkaline 
chlorides,  which  prevent  the  volatilisation  of  the 
selenium  as  chloride. 

Hypophoephorous  acid  in  alkaline  eolation, 
and  potasdum  iodide  in  acid  solution,  have  also 
been  recommended  as  reducing  agents  (Zdtsoh. 
anoig.  Chem.  41,  448 ;  and  Amer.  J.  SoL  1896, 
[4]  1,  416).  For  a  review  of  methods  for  esti- 
mating selenium,  see  Zdtsoh.  anoig.  Chem.  1904, 
41,  291). 

Silver. 

As  chloride  AgCl,  or  bromide  AffBr.  The 
solution  is  acidifiM  with  nitric  add,  neated  to 
boilinff,  and  mixed  with  a  slight  excess  of  sodium 
chloriae  or  potasdum  bromide.  Estimation  as 
bromide  is  to  be  recommended,  since  silver 
chloride  is  not  quite  insoluble  in  pure  water. 
The  precipitate  is  washed  with  hot  water,  dried, 
detached  from  the  paper  as  far  as  posdble, 
transferred  to  a  poroelam  crudble,  and  dried  at 
150°,  or  heated  slowly  until  it  shows  signs  of 
f  udon  at  the  edges,  and  weighed.  The  filter  is 
burnt  and  the  ash  added  to  the  cmoible,  which 
is  again  weighed.  The  increase  in  wdsht  is 
filter  ash  and  metallic  silver.  The  quantity  of 
bromide  or  chloride  corresponding  with  the 
latter  is  calculated  and  added  to  Uie  weight  of 
thepredpitate. 

Bbdlnm  ia  weighed  in  the  form  of  chloride 
together  with  any  potasdum  which  may  be 
present,  and  is  estimated  by  difference,  or  it  may 


ANALYSIS. 


249 


be  estimated  directly  as  sulphate  or  chloride  if 
potaemum  is  absent. 

The  following  reagent  precipitates  sodium 
eren  from  very  dilate  solutions,  and  is  not 
interHered  with  by  the  other  alkali  metals  or 
by  magnesium  and  the  metals  of  the  alkaline 
earths.  Three  grams  of  bismuth  nitrate  and 
30  grams  of  potassium  nitrite  are  dissolved  in 
water  containmg  sufficient  nitric  acid  to  remove 
any  turbidity,  about  1  '6  grams  of  ctesium  nitrate 
are  added,  and  the  solution  diluted  with  water 
to  100  c.c.  The  precipitation  should  be  carried 
oat  in  a  stoppered  l^otue  in  an  inert  atmosphere. 
The  precipitate,  5Bi(NO,)„9CsNO„6NaNO„ 
contains  3*675  p.c.  sodium  (v.  Ball,  Chem.  Soc. 
Tiana.  1910,  97, 1408). 

Stronttimi* 

(a)  As  9ulphaU  SrSOu.  The  solution,  which 
must  contain  but  little  nee  acid,  is  mixed  with 
excess  of  dilute  sulphuric  acid  and  at  least  an 
equal  volume  of  alcohol,  and  the  precipitate  is 
washed  with  alcohol.  If  alcohol  cannot  oe  used, 
a  much  larger  excess  of  sulphuric  acid  is  added 
and  the  precipitate  Ss  washed  with  cold  water, 
bat  the  results  are  less  exact. 

(d)  As  carbanait  SrOO,  (which  must  not  bo 
heated  too  strongly)  after  precipitation  by  am- 
monium carbonate. 

According  to  Winkler  (Zeitsch.  angew. 
Chem.  1918,  31,  L  80),  the  most  convenient  and 
exact  method  of  estimating  strontium  is  to 
predpttate  it  as  oxalate  by  the  addition  of  a  10 
p.c.  solution  of  potassium  oxalate  and  washing 
with  saturated  strontium  oxalate  solution.  The 
precipitate  is  dried  at  100°,  and  weiehed 
as  SiC,04,H,0,  or  at  132%  and  weighed  as 
SrC,04. 

TWtorinm. 

(a)  As  tetturiwn,  by  reducing  solutions  of 
leQurooa  or  teUurio  compounds  with  sulphur 
dioxide  and  hydraune  hydrochloride  (Lenher, 
J.  Amer.  (%em.  Soa  1908,  30, 387).  Other  reduc- 
ing agents  have  been  employed :  sulphur  dioxide 
and  potaasiam  iodide,  hypophosphorous  add, 
and  grape  sugar  in  alkaUne  solution. 

(S)  As  dkxnde  TeO,  (v.  Amer.  J.  ScL  1909, 
(iv.)  28,  112). 

TbaBiiim. 

(a)  As  thaUaus  iodide  TU.  The  solution  is 
heated  with  sulphurous  acid  to  reduce  all  the 
thallium  compounds  to  tballous  salts,  allowed  to 
oooU  and  then  mixed  with  excess  of  ^tassium 
iodide.  The  predpitate  is  washed  with  dilute 
aloohcd,  and  dried  on  a  weighed  filter  at  170* 
(if.  Banbignv,  Compt.  rend.  1892,  113,  644). 

(b)  As  tkaOoua  flaiinicJiioride.  ThUa  salt  is 
very  insolable,  but  is  difficult  to  filter  (Grookes, 
Selsct  Methods,  4th  ed«  p.  172). 

Tin* 

As  aride  SnOj,  which  is  obtained  when  tin 
or  one  of  its  ^loys  is  treated  with  nitric  acid. 
The  solution  is  boiled  for  ten  minutes  to  ensure 
complete  precipitation,  and  the  precipitate  is 
digested  for  an  hour  with  dilute  nitric  acid 
(1:6)  at  100*  to  remove  other  metals,  washed 
with  hoi  water,  and  isnited. 

In  other  cases  we  tin  is  precipitated  as 
hydiated  oxide.  If  the  solution  contains  stannous 
salts,  tbe  latter  are  oxidised  by  chlorine  or  by 
kydroeUorio  acid  and  potasdum  chlorate,  am- 
monia added  until  a  slight  precipitate  forms, 
and  hydrochloric  add  until  the  precipitate  just 


redissolves.  The  solution  is  then  mixed  with  a 
moderately  large  quantity  of  a  strons  solution 
of  ammonium  nitrate  or  sodium  sulphate,  and 
boiled  for  some  time.  The  precipitate  is  washed 
with  hot  water  bv  decantation  and  on  the  filter, 
dried,  and  heated.  To  ascertain  if  precipitation 
is  complete,  a  small  quantity  of  the  filtrate  is 
added  to  a  hot  solution  of  ammonium  nitrate  or 
sodium  sulphate. 

If  the  tin  has  been  precipitated  as  stannic 
sulphide,  the  latter  is  washed  with  a  solution  of 
sodium  chloride,  and  finally  with  a  solution  of 
ammonium  acetate,  dried,  and  roasted  in  a 
porcelain  crucible  until  the  weight  is  constant. 
Decomposition  is  facilitated  by  adding  a  small 
quantity  of  ammonium  carbonate. 

In  all  cases  the  filter  is  burnt  separately  and 
the  ash  dropped  into  the  crucible. 

TttaniuiiL 

As  dioxide  TiOt,  after  precipitation  by 
ammonia.  UsuaUy  the  substance  is  dissolved 
in  sulphuric  acid,  *  or  is  fused  with  potassium 
hydrogen  sulphate  and  dissolved  in  water.  The 
solution  is  diluted  largely  and  boiled  for  some 
time,  when  all  titanium  is  predpitated  as  hy- 
drated  oxide^  which  is  rendered  anhprdrous  by 
ignition.  The  solution  should  contam  0-5  p.c. 
of  free  sulphuric  acid ;  if  less,  the  precipitate  is 
impure,  if  more,  precipitation  is  incomplete 
(Levy).  In  presence  of  iron  the  results  are 
always  somewhat  too  high. 

BaskerviUe  recommends  fusing  titaniferous 
uron  ores  with  potassium  hydrogen  sulphate  con- 
taininz  some  sodium  fluoride.  The  product 
is  bo£d  with  water  containing  nitric  acid  and 
then  neutralised  with  ammonia.  The  predpitate 
is  dissolved  in  dilute  hydrochloric  acia,  avoiding 
any  excess.  The  liquid  is  then  saturated  with 
sulphur  dioxide  and  boiled,  the  precipitate 
being  collected,  ignited,  and  weighed  as  TiO,  (J. 
Soc  Chem.  Ind.  1900,  19,  419 ;  also  J.  Amer. 
Chem.  Soc.  1903,  25,  1073 ;  and  1910,  32,  957). 

Tungiteiu 

As  iungstic  anhydride  WO,.  The  solution 
containing  the  tungsten  as  an  alkaline  tungstate 
is  neutrafised  with  nitric  acid  and  precipitated 
with  a  neutral  solution  of  mcrcurous  nitrate. 
The  precipitate  is  washed  with  a  solution  of 
mercurous  nitrate,  dried,  and  heated  in  a  por- 
celain crudble,  when  tungstio  anhydride  is  left. 

Fused  lead  tungstate,  when  boiled  with  strong 
hydrochloric  acid,  gives  a  precipitate  of  tungstic 
acid  (Brearley,  Chem.  News,  1899,  79,  64). 

UraniuoL 

(a)  As  the  oxide  Vfi^.  The  solution,  oxi- 
dised if  necessary  by  nitric  acid,  is  heated  to 
boiling  and  mixed  with  a  AiglU  excess  of  am- 
monia. The  precipitate  of  acid  ammonium 
uranate  is  washed  with  ammonium  chloride  solu 
tion,  dried,  and  strongly  heated. 

(6)  Asthe|iyropAo8pAa<e(UO«),P,07,obtained 
bv  precipitatmg  uranyl  ammonium  phosphate 
(tJ0,)(NH4)P04  with  ammonium  phosphate  in 
the  presence  of  ammonium  acetate  and  igniting 
the  precipitate  at  low  redness.  For  the  appli- 
cation of  this  process  to  uranium  minerals,  see 
Low's  Technical  Methods  of  Ore  Analysis,  3rd 
ed.  p.  223 :  and  J.  Amer.  Chem.  Soc.  1901, 23, 685. 

VanadlBm. 

(a)  As&an«mt)yrot»na^^a<6  2BaO*V.O,.  The 
solution  is  neutralised  with  ammonia,  heated  to 
boiling,  mixed  with  excess  of  barium  chloride. 


250 


ANALTSIS. 


agitated,  and  cooled  quickly  out  of  contact  with 
air.    The  precipitate  is  washed  and  heated. 

(ft)  Ab  manganese  pvrovanadaie  2MnO>y20c. 
llie  solution  is  mixed  with  a  sUght  excess  of  ammo- 
mom  chloride  and  ammonia,  manganese  chloride 
or  sulphate  mixed  with  ammonium  chloride  is 
added  in  excess,  and  the  liquid  is  boiled  two  or 
three  minutes  and  allowed  to  cool  out  of  con- 
tact with  the  air.  The  precipitate,  which  should 
be  brownish  yellow  and  free  from  oxidation 
products,  IB  washed  with  cold  water  and  heated. 

(c)  As  penioxide  V.O^,  obtained  (i.)  by  pre- 
cipitating Barium  or  lead  vanadate,  decomposing 
with  sulphuric  acid,  filtering,  evaporating  the 
filtrate,  and  igniting;  (ii.)  b^  precipitating  and 
igniting  mercury  vanadate ;  (iii.)  by  precipitating 
ammonium  vanadate  by  ammonium  chloride 
and  igniting  the  precipitate. 

For  other  methods  of  estimating  and  separat- 
ing vanadium,  v,  A.  Oamot^  Gompt  rend  104, 
1803  and  1850;  Cbem.  Soo.  Abstr.  1887,  896; 
Chem.  Zeit.  1905,  29,  392 ;  Amer.  J.  Sci.  1910, 
30,220. 

Ziiie* 

(a)  As  oceide  ZnO,  with  previous  precipitation 
by  sodium  carbonate  in  aEMence  of  ammonium 
salttf. 

(()  Ab  sulphide  ZnS,  by  Rose's  method  after 
predpitating  with  ammonium  sulphide. 

like  filtration  of  the  zinc  sulphide  may  be 
promoted  by  precipitating  in  the  presence  of 
ammonium  acetate  or  thiooyanate,  and  washing 
with  a  5  p.0.  solution  of  either  of  these  salts. 
If  mercuno  chloride  is  added  to  the  solution, 
the  mixed  precipitate  ol  mercuric  and  sine 
sulphides  filtera  much  better  than  the  latter 
alone ;  the  former  is  expelled  on  ignition. 

ZireonJiim. 

Zirconium  is  quantitatively  precipitated 
by  ammonium  phosphate  from  solutions  which 
are  either  neutral  or  contain  up  to  20  p.c. 
of  sulpjiuric  acid.  The  precipitate  is  calcined 
and  weighed  as  pyropnospnate,  the  factor 
for  conversion  to  ZrO^  being  0*487.  The 
method  may  be  used  for  the  estimation  of 
zirconium  in  presence  of  iron,  chromium,  and 
aluminium,  but  an  acidity  equal  to  20  p.c.. 
sulphuric  acid  is  necessary  if  uie  first  two  are 
present,  or  10  p.a  if  only  aluminium  is  present, 
in  order  to  avoid  simultaneous  precipitation  of 
these  metals  (Nicolardot  and  Reglads,  Compt. 
rend.  1919,  168,  348). 

Acid  Radicals. 

Garbonie  add. 

The  estimation  of  carbon  in  carbonates  may 
be  made  by  a  loss  in  weight  method.  The  car- 
bonate is  weighed  into  an  apparatus  fitted  with 
a  stoppered  dropping  funnd  containii^  acid 
to  decompose  the  woonate,  and  an  exit  tube 
containing  strong  sulphuric  acid  to  dry  the 
escaping  gas.  The  apparatus  is  weighed  with 
the  acids,  &a,  after  the  carbonate  has  been 
introduced.  Tlie  add  is  then  allowed  to  drop 
on  the  carbonate  until  the  decomposition  is 
complete^  and  the  liquid  boiled  to  expel  dis- 
solved carbon  dioxide.  The  apparatus  u  again 
weighed  and  the  loss  of  weight  gives  the 
amount  of  carbon  dioxide.  The  apparatus  is 
figured  in  mott  treatises  on  quantitative  analysis. 
More  accurate  results  are  ootained  by  weigning 
the  carbon  dioxide  directly  by  absorbing  it  in 


weighed  tubes  containing  soda  lime  or  in  bulbs 
contckining  aoueous  caustic  potash.  For  a  com- 
plete form  of  apparatus  for  this  estimation,  see 
Thorpe's  Quantitative  Analysis,  9th  ed.  p.  869 
and  Clowes  and  Coleman's  Analysis,  8ta  ecU 
p.  104. 

When  carbonates  and  sulphides  occur  to- 
gether, the  gases  evolved  on  treatment  witii 
acid  are  passed  into  a  solution  of  copper  acetate 
acidified  with  acetic  acid  and  heated  to  boiling. 
Hydrogen  sulphide  is  absorbed,  with  forma- 
tion of  copper  sulphide,  and  carbon  dioxide 
passes  on. 

For  a  convenient  apparatus  for  determining 
small  quantities  of  carbon  dioxide,  see  Sinnati 
(Analyst,  1913,  136).  As  shown  by  Mor;^an  a 
solution  of  phosphoric  acid  may  conveniently 
replace  the  hydrochloric  or  sulphuric  acid 
usually  employed  (Proc.  Chem.  80c.  1904,  20, 
167). 

For  the  estimation  of  carbon  dioxide  in  the 
presence  of  nitrites,  sulphides,  and  sulphites,  see 
Marie,  Chem.  Soc.  Trans.  1909,  1491;  and 
Wolkowitz,  Zeitsch.  angtw.  Chem.  1894,  165. 

Chlorie  aeld. 

Any  chlorine  present  as  chloride  is  deter- 
mined, the  chlorate  reduced  by  a  sine-copper 
couple,  and  the  chlorine  aeain  determmed. 
The  difference  is  the  amount  of  chlorine  ATjgfeing 
as  chlorate  (Thorpe,  Chem.  80a  Trans.  1873, 
541).  Thin  granulated  zinc  is  washed  with 
caustic  soda  solution,  then  with  dilute  sulphuric 
acid,  which  is  allowed  to  act  for  a  short  time, 
and  finallv  with  water.  It  is  then  covered  witii 
about  100  cc.  of  a  3  p.c.  solution  of  copper 
sulphate  heated  to  iO'^-SQ^.  When  most  of  the 
copper  has  been  deposited,  the  liquid  is  carefully 
poured  off,  and  treatment  repeated  with  a  fresh 
quantity  of  solution.  The  zinc-copper  couple 
is  now  very  carefully  washed  with  distilled  water 
by  decantation,  not  more  than  0'5  gram  of 
potassium  chlorate,  or  |^e  equivalent  quantity 
of  any  other  chlorate,  is  weighed  out  mto  the 
beaker  and  dissolved  in  about  25  cc.  of  warm 
water,  which  should  just  cover  the  couple. 
The  liquid  is  heated  sently  for  half  an  hour,  tnen 
boiled  for  half  an  nour,  dilute  sulphuric  acid 
added  drop  by  drop  until  the  white  precipitate 
of  zinc  hyoroxide  and  oxychloride  just  dissolves, 
filtered,  the  filtrate  neutralised  with  pure  calcium 
carbonate,  and  the  chlorine  estimated  by 
standard  silver  nitrate  solution  (Chem.  Soc. 
Trans.  1888,  166). 

This  reduction  may  also  be  effected  by 
Oevarda's  alloy  (Al  45,  Zn  5,  Cu  50).  Jannason 
recommends  hydroxylamine  sulphate  and  excess 
of  nitric  acid  as  a  suitable  reaucing  agent  for 
chlorates  while  bromates  and  iodates  are  best 
reduced  by  hydroxylamine  in  ammoniaoal  solu- 
tion  (Ber.  1905,  38,  1576).  Formaldehyde  in 
dilute  nitric  acid  reduces  chlorates  in  30  minutes 
and  bromates  in  21  hours;  iodates  aie  notreduoiMl 
(Grfitzner.  Arch.  Fharm.  1896,  294,  634 ;  com- 
pare Brunner  and  Mellet,  J.  pr.  C9iem.  1908,  77, 
33). 

Hydrobroml0»  hydroehloiie,  and  hydilodle 
adds. 

As  silver  salts  (AgBr,  AgQ,  Agl).  The  solu- 
tion is  mixed  with  excess  of  silver  nitrate, 
acidified  with  nitric  acid,  and  heated  to  boiling. 
The  precipitate  is  treated  exactiy  as  in  the  esti- 
mation of  silver. 


ANALTSL«;. 


251 


(a)  As  calcium  fuoride  CkF^  in  the  case  of 
■olabfe  fiuoridee.  The  folutkm  is  mixed  with 
a  modeEate  exoeas  of  sodhun  oarbonate,  heated 
to  *>«fl™g,  and  mixed  with  excess  of  oafcium 
Qhknde.  The  piecipitate  is  washed,  dried,  and 
heated  to  redness  in  a  platinam  crucible,  then 
tteated  with  excess  of  acetic  acid,  evaporated  to 
dzyness,  and  heated  to  ex^  excess  of  acid.  The 
product  is  now  heated  with  water,  and  the  in- 
sofaihle  caloium  fluoride  filtered  off,  washed,  and 


(6)  Indirectly  as  Mam  fMoride  SiF«.  The 
finely  powdeied  solid  substance  m  pUoed  in ' 
a  deep  platinum  cmoifale  and  covered  with  three 
or  four  times  its  wei^t  of  pure  precipitated  silica, 
the  weight  of.  whii£  is  accurately  known.  8ul- 
phozio  add  is  then  added,  and  the  crucible  gently 
heated  for  half  an  hour.  The  temperature  is 
raised  to  expel  most  of  the  sulphuric  acid,  the 
residue  tnated  with  hydzochlonc  acid,  washed, 
dried,  and  heated.  The  hydrofluoric  add  is 
calculated  from  the  loss  in  weifi^t  of  the  silica: 
4HF  «■  SiO^  The  amount  of  silica  in  the  sub- 
stance must  be  known,  and  its  weight  added  to 
that  of  the  admixed  silioa. 

(e)  By  dtMiOaiicn  and  weighing  as  cdleium 
fiuonde.  The  fluoride  is  decomposed  by  concen- 
trated solphuric  add  in  a  platinum  apparatus; 
the  hydrogen  fluoride  carried  off  in  a  current  of 
air  and  carbon  dioxide  and  absorbed  in  a  solution 
of  pure  caustic  soda  contained  in  a  platinum 
dish.  CSaloinm  chloride  is  added  to  this  solution 
and  the  predpitate  (OaCO,  and  CaF,)  washed, 
ignited,  and  Ixeated  with  dilute  acetic  acid  in 
moderate  excess.  After  evaporation  to  expel 
this  excess  of  add,  the  residue  is  t^cen  up  with 
water  and  the  insoluble  calcium  fluoride  coUeoted, 
washed,  and  ignited  ( Jannasch  and  Rdttsen, 
Zdtsoh.  anorg.  Chem.  1896,  9,  267).  The 
appazatos  employed  is  figured  in  Jannasch's 
Praktisoher  Leitfaden  &t  Gewichtsanalyse, 
2nd  ed.  411  (compare  ako  J.  Amer.  Chem. 
Soc.  1901,  23,  825;  and  Chem.  News,  1905, 
92,  184). 

(d)  Direotiy  as  sUicon  fiuoride  (Fresenius). 
The  mineral  is  finely  powdered  and  intiinatdy 
mixed  with  kpiited  quarts  and  heated  with  con- 
centrated sulphurio  add  in  a  dry  y-tube  at 
160^-100^.  A  current  of  dry  air  free  from  carbon 
dioxide  is  drawn  through  the  decompodtion  tube 
and  thence  through  a  series  of  five  y-tubes. 
The  first  of  these  is  empty  and  cooled  by  im- 
menion  in  cold  water;  the  second  contains  glass- 
wool,  or,  if  the  substance  contains  chlorine,  half 
is  filled  witii  pumice  impregnated  with  anhydrous 
copper  sulphate,  and  the  other  half  with  pure  dry 
calcrom  chloride.  The  third  and  fourth  tubes 
ace  wei^^ed  and  serve  to  absorb  the  sIKoon 
fluoride ;  the  third  contains  pumice  moistened 
with  water,  and  the  fourth  contains  soda  lime 
and  caldum  chloride.  The  fifth  tube  is  a  guard 
tube  containing  the  same  reagents  as  the  fourth. 
After  one  or  two  hours  the  decompodtion  of  the 
fluoride  is  complete,  and  the  gala  in  weight  of  the 
absorption  tubes  represents  we  amount  of  silicon 
fluorioe  generated.  This  process  may  be  ren- 
dered vommetric  (o.  Vcivmdrie  Mdicn). 

Hydrogttii  tuIpUde  (fnlphldes). 

Insoluble  sulphides  are  decomposed  by  hydro- 
chloric acid  in  a  flask  similar  to  that  used  in 
the  gravimetric  estimation  of  carbonic  acid,  and 


the  eas  evolved  is  led  into  two  or  three  bulb 
M-tuoes  containing  a  solution  of  bromine  in 
diluto  hydioohlono  add,  which  oonverts  the 
hydrogen  sulfide  into  sulphuric  acid.  When 
decompodtion  is  complete^  tne  liquid  in  the  flask 
is  boikd,  and  the  last  traces  ol  the  gas  are  drawn 
through  the  bulbs  by  means  ol  an  aspiratcMr. 
The  contents  of  the  bulb  tubes  are  transferred 
to  a  beaker,  heated  to  expd  bromine,  and  the 
sulphuric  add  predpitated  by  barium  chloride. 

Sulphides  which  are  not  decomposed  by  hy- 
drochloric add  may  be  oxidised  witn  aqua  regie, 
hydroddoric  acid  and  bromine,  or  hyorochlorie 
acid  and  potassium  chlorate,  the  sulphuric  acid 
formed  bemg  weighed  as  barium  sulphate. 

mirieadd. 

(a)  Indirectiy,  as  ammonia,  by  means  ol  the 
zinc-copper  couple  (Thorpe).  A  lino-copper 
couple  («L  CMonc  acid)  ia  made  in  a  flask  mto 
which  is  weighed  a  quantity  of  the  nitrate  cor- 
responding with  not  more  than  0*6  ^[ram  of 
potasdum  nitrate,  and  sufficient  water  is  added 
to  just  cover  the  couple.  The  flask  is  attached 
to  a  condenser,  the  other  end  of  which  is  con- 
nected with  a  y-tube  or  flask  containing  hydro- 
chloric acid,  as  in  the  estimation  of  ammonia. 
The  liquid  is  gently  heated  for  some  time,  and 
then  distilled  nearly  to  dryness.  After  cooling, 
a  further  quantity  of  water  is  added  to  the  couple, 
and  distillation  repeated.  The  ammonia  in  the 
distillato  is  estimated  as  platinichloride^  or  is 
recdved  in  a  measured  volume  of  standard  add 
and  titrated.  The  reduction  can  also  be  oon- 
venientiy  effected  by  the -use  of  Devarda's  aUoy 
(v.  Chianc  acid)  in  alkaline  solution  (Analyst, 
1910,  35,  307). 

(6)  Schloesing*s  mdhod.  When  a  solution  of 
a  nitrate  is  heated  with  an  acid  solution  of  a 
ferrous  salt,  the  nitrate  is  decomposed,  the 
whole  of  the  nitrogen  being  evolved  as  nitric 
oxide,  which  is  measured.  The  difficulty  lies 
mainly  in  obtaining  the  nitric  oxide  free  from 
air.  The  apparatus  employed  consiste  of  a  small 
Hw^illifig  fladc  provided  with  a  side  tube  which 
terminates  under  a  gas-cdlecting  tube  in  a  mer- 
curial trough.  The  neck  of  the  flask  is  fitted 
with  a  cork,  which  carries  a  tube  funnd  provided 
with  a  stop-cook  and  another  tube  connected 
with  a  caroon-dioxide  apparatus.  Carbon  di- 
oxide free  from  air  is  passed  into  the  apparatus 
until  all  air  is  expelled  and  the  gas  issuuig  from 
the  exit  tube  is  completely  absorbed  by  caustic 
potash.  The  substance  containing  the  nitrate, 
which  must  be  in  the  solid  condition,  is  dissolved 
in  2  or  3  c.c.  of  concentrated  ferrous  chloride 
solution,  mixed  with  1  co.  of  strong  hydrochloric 
acid,  and  introduced  into  the  flask  b\  means  of 
the  funnel  tube,  care  being  taken  tiiat  no  air 
enters.  The  dish  and  the  funnd  are  rinsed  with 
very  small  quantities  of  acid,  the  object  being 
to  use  as  little  liquid  as  possible.  The  contents 
of  tiie  flask  are  then  rapidly  boiled  to  dryness, 
the  evolved  ffas  being  collected  in  the  tube  over 
mercury,  and  carbon  dioxide  \b  driven  through 
the  apparatus  to  expd  all  nitric  oxide,  llie 
mixture  of  nitric  oxide  and  carbon  dioxide  is 
transferred  to  an  apparatus  for  gas  analysis ;  the 
latter  absorbed  by  caustic  potash,  and  the  former 
mixed  witii  oxygen  and  absorbed  by  alkaline 
pyroealloL  Nitrites  are  converted  into  nitrates 
by  aadition  of  hydrogen  peroxide  during  evapo- 
ration of  the  original  solution  (v.  Warington, 


202 


ANALysia 


Chem.  Soo.  Trans.  1880,  468,  and  1S82, 
346). 

(c)  By  standard  indigo  solution  (Warington, 
Chem.  News,  35,  45,  and  Ch»in.  Soo.  Trans. 
1879,  578). 

(ef)  As  1  :  4t^iphenyl'2  :  R-endanHodihydro- 
triaxoU  nilraU  CsoH,«N4*HNO,.  A  10  p.o.  so- 
lution of  the  base  1 :  4-diphenyl-3 :  5-endanilo- 
hydrotriazole  *  Nitron,* 


C,H,N 
H 


N-CeH, 


-N 


in  5  p.o.  aoetio  aoid  produces  a  Toluminoua 
white  precipitate  in  dilute  nitric  aoid  or  nitrate 
solution.  Nitrites  interfere  by  ffiving  a  sparingly 
soluble  salt  with  this  base;  tney  are  removed 
by  hydrasine  sulphate.  Bromides,  iodides, 
chlorates,  perohlorates,  and  chromates,  are  also 
precipitated  by  nitron,  and  must  be  removed. 
Ox^nio  matters  do  not  seriously  affect  the 
method,  which  hss  been  tested  successfully 
with  solutions  oontainine  0-5  p.c.  of  gelatine, 
and  2  p.o.  of  dextrin  (Busch,  Ber.  1905,  38, 
861).  The  method  gives  favourable  results  for 
nitrates  in  water  or  fertilisers  (Collins,  Analyst, 
1907,  32,  349). 

{e)  Howard  and  Chick  have  shown  that 
cinchonamine  ^Ives  a  veiy  insoluble  nitrate  and 
can  be  used  m  estimating  nitric  acid  and  its 
salts  (J.  Soo.  Chem.  Ind.  1909,  28,  53). 

OxalleMld, 

As  caldum  oxalate.  The  method  is  already 
indicated  under  Calcium. 

Phospborie  aeid. 

As  magnesium  pyrophosphate  Mg,P,07.  The 
operation  is  conducteid  as  in  the  estimation 
of  magnesiuuL  If  magnesium  sulphate  is  used 
as  the  precipitant,  the  precipitate  may  be  con- 
taminated with  basic  magnesium  sulphate ;  it  is 
therefore  advisable  to  employ  a  solution  of  the 
chloride,  which  is  made  as  foUows  :  85  grams  of 
crystallised  magnesium  sulphate  are  dissolved  in 
boiling  water,  acidified  with  5  cc.  of  hydrochloric 
aoid,  mixed  with  an  aqueous  solution  of  82 

Sams  of  crystallised  barium  chloride,  boiled,  and 
tered.  A  few  drops  of  magnesium  sulphate 
solution  are  added  to  be  sure  that  there  is  no 
excess  of  barium,  then  165  grams  of  pure  am- 
monium chloride,  and  260  c.c.  of  ammonia,  and 
the  solution  diluted  to  1  litre.  After  two  or 
three  days  th»  solution  is  filtered.  In  many 
cases  the  phosphoric  acid  is  first  separated  by 
ammonium  molybdate  {v.  Methods  of  separation), 
Sffideaeld. 

As  siUea  SiO,*  Soluble  silicates  are  acidified 
with  hydrochloric  acid  and  evaporated  to  com- 
plete dryness;  moistened  with  strong  hydro- 
chloric acid,  again  evaporated  twice  to  dr^oiess, 
so  as  to  agglomerate  the  silica,  the  residue  treated 
with  dilute  acid,  and  the  insoluble  silica  washed 
with  hot  water  and  ignited. 

Insoluble  silicates  are  very  finely  powdered, 
intimately  mixed  with  about  ^ye  times  their 
weiffht  of  a  dry  mixture  of  sodium  and  potassium 
carbonates  in  equal  proportions,  and  neated  to 
redness  in  a  platinum  orucible  for  half  an  hour. 
The  cooled  mass  is  treated  with  water,  acidified 
with  hydrochlotic  acid,  and  evaporated  as 
above. 

(For  the  separation  of  silica  «hen  the  alkalis 


have  to  be  estimated,  v.  Methods  of  separatdon. 
Group  VI.) 

Salphurie  aeld. 

As  barium  sulphate  BaSOi,  b^  precipita- 
tion with  barium  chloride.  The  chief  difficulty 
arises  from  the  tendency  of  the  barium  sulphate 
to  separate  in  a  finely  divided  condition  and  to 
carry  down  impurities,  especially  in  presence  of 
nitrates  and  potassium  salts.  These  sources  of 
error  are  avoided  by  taking  care  that  the  solution 
is  somewhat  dilute,  is  fiie  from  nitrates,  and 
contains  a  moderate  but  not  excessive  quantity 
of  free  hydrochloric  acid.  The  solution  and  the 
barium  chloride  solution  should  both  be  heated 
to  boiling,  and  mixed  gradually,  with  continual 
agitation.  The  liquid  may  be  mtered  as  soon  aa 
it  has  become  dear,  and  the  precipitate  is  washed 
with  hot  water  and  heated  to  dull  redness.  If 
too  litUe  hydrochloric  acid  is  present,  the  pre- 
cipitate is  liable  to  be  impure ;  if  a  very  large 
excess  of  the  acid  is  present,  precipitation  is  not 
quite  complete  (compare  Allen  and  Johnston, 
J.  Amer.  Chem.  Soa  1910,  32,  588). 

Sulphnrons  aeld. 

Indirectly  as  barium  sulphate  after  oxidation 
by  bromine  water,  excess  of  bromine  being  ex- 
pelled by  boiling. 

Thiosalphnrie  add. 

Indirectly  as  barium  sulphate  after  oxidatfen 
by  bromine  water,  excess  of  bromine  being  ex- 
pelled by  boiling. 

Water  is  usually  estimated  by  difference.  If 
a  direct  determination  is  required,  the  method 
to  be  adopted  will  depend  upon  ciroumstanoes. 
In  many  cases  it  is  sufficient  to  heat  the  subetanoe 
on  a  watch-glass,  or  in  a  crucible  in  a  drying 
oven,  at  a  definite  temperature,  until  the  weight 
is  constant.  During  weighing  the  dried  sub- 
stance must  be  carefully  protected  from  the 
air.  Attention  must,  however,  be  paid  to  the 
possibility  of  the  volatilisation  of  substances 
other  than  water.  Many  hydrated  haloid  salts, 
for  example,  lose  part  of  uieir  add.  In  such 
cases  the  substance  is  previously  mixed  with 
a  known  weight  of  perfectly  dry  lead  monoxide. 
Ammonia,  ammonium  salts,  and  volatile  oxjpinic 
matter  may  also  be  given  off.  If  the  drymg  is 
conducted  in  a  glass  tube,  the  vapours  may  be 
led  into  standard  add  and  the  ammonia  deter- 
mmed  by  titration :  the  total  loss,  minus  the 
ammonia,  ^ves  the  amount  of  water.  Some 
substances  mcrease  in  weight  in  consequence  of 
oxidation.  Frequently  it  is  desirable  to  collect 
the  evolved  water  and  weigh  it  directly.  The 
substance  is  introduced  into  a  glass  tube  (plain, 
or  with  a  bulb  in  the  middle)  drawn  out  and 
bent  at  right  angles  at  one  end,  which  pasKS 
directly,  without  any  intervenins  indiarubber 
tube,  through  the  cork  of  a  U-tube  contaxnins 
either  calcium  chloride  or  pumice  moistenea 
with  strong  sulphuric  add  (v.  Oboahig  akalysd). 

In  certain  cases  the  water  may  frequently 
be  estimated  with  considerable  accuracy  by 
boiling  the  substance  with  paraffin  oil  and 
measuring  the  expelled  water  in  a  sraduated 
tube  (c/.  Huntly  and  Coste,  J.  Soc.  Cnem.  Ind. 
1913,  32,  62;  CampbeU,  ibid,  1913,  32,  67; 
Skertchley,  ibid,  70 ;  St.  von  Haydin,  Analyst, 
1913,  177 ;  lifichel,  Analyst,  1913,  207). 

All  fluosilicates,  evtn  topas,  evolve  silicon 
fluoride  on  ignition,  and  water  is  estimated  by 
mixing  t^e  mineral  with  lead  oxide  in  a  hard 


ANALYSia 


263 


gkas  tabe,  heating  the  mixtme  in  a  current  of  dry 
air  aad  iMwwing  the  gasei  over  a  layer  of  lead 
ooide  obntained  in  the  same  tube.  The  water 
IS  collected  and  weighed  in  calcium  chloride  tubes. 

Mbthods  of  Sbparation. 

A.  The  BUinuUian  of  the  MeiaU  in  their  Ores 

and  AUoy9. 

In  this  section  the  metals  are  arranged  in  the 
Older  in  which  the^  occur  in  the  qualitative 
gnnips.  Both  gravimetric  and  volumetric  me- 
thods are  included  in  this  description,  the 
latter  being  indicated  wherever  possible,  owing  to 
the  greater  rapidity  with  whidi  the  analysis  can 
beezeonted. 

GboufL 

SQiver  is  separated  from  all  other  metals  by 
Seating  its  ores  and  alloys  with  moderately 
strong  nitrio  acid,  evaporating  off  excess  of 
solvent,  diluting  with  water,  and  adding  to  the 
filtered  solution  either  hydrochloric  acid  or 
sodiam  chloride.  To  remove  any  lead  or  thaUous 
chloride  which  may  be  present^  the  precipitate 
is  extracted  repeatedly  with  warm  water;  it 
should,  however,  be  remembered  that  silver 
chloride  is  not  absolutely  insoluble  in  hot 
water.  SilvCT  is  conveniently  estimated  volu- 
metrically  in  the  above  dilute  nitric  acid  solution, 
after  boinng  off  nitrous  fumes,  by  adding  ferric 
indicatcMT  and  titrating  with  standard  ammonium 
thioeyanate  in  accordance  with  Volhard's  method 
(MS  KotfuneCrfte  section).  The  presence  of 
other  metals  having  colourless  salts  does  not 
interfere  with  this  process ;  nickel,  cobalt,  and 
eopper  must  not  be  present  to  any  large  extent, 
aoa  mevcuy  should  be  absent  because  of  the 
inaolnhility  m  mercuric  thioeyanate.  When  more 
than  60  p.a  of  copper  is  present,  the  silver  is 
precipitated  with  excess  of  alkali  thioeyanate. 
Ilia  well*  washed  sQver  thioeyanate  is  decomposed 
by  strong  nitrio  acid,  the  sulphuric  acid  proauced 
pieeipttated  by  barium  nitrate,  and  the  Volhard 
titrataon  effected  without  filtering  off  the  barium 
solphi^  (v.  Ber.  1906,  88,  666). 

The  silver  in  argentiferous  galena  is  estimated 
by  fusing  the  sulphide  with  crude  potassium 
hydropen  tartrate  (arffol),  and  sodinm  carbonate 
in  an  iron  omcible,  and  by  heating  the  lead-silver 
bottOD  thus  obtained  in  a  porous  bone-ash  cru- 
cible ('  cupel ')  until  the  lead  is  removed  as 
oxide^  partly  by  volatilisation  and  partljr  by 
absofption  into  the  oupcL  The  residual  silver 
IS  detailed  from  the  oold  cupel  and  weighed. 

Gold  quarts  is  assayed  for  silver  by  heating 
the  mtneral  with  lead  oxide,  and  a  reducing  flux, 
when  the  lead  produced  extracts  both  the  gold 
and  silver.  This  alloy  is  cupelled,  and  the  silver- 
gold  button  is  'parted '  by  heating  with  strong 
nitrio  acid  diluted  with  three  parts  of  water ;  the 
rendual  gold  is  collected,  upoited,  and  weighed. 
The  silver  is  precipitated  by  hydrochloric  acid 
from  the  nitrio  aeid  scdution.  when  more  than 
30  pue.  of  gold  is  present  in  the  button  before 
partangp  this  metal  will  retain  silver.  In  order  to 
prevent  this  retention,  a  known  wei^t  of  silver 
IS  added  to  the  fused  button.  (For  further 
details  of  the  separations  of  gold,  silver,  and  lead 
in  the  dry  way,  see  Ajisatdio.) 

ThaOium^  in  the  more  stable  thallous  con- 
dition to  which  thallic  salts  are  readily  reduced, 
is  separated  from  the  metals  of  Group  II.  by 


precipitating  the  latter  with  hydrogen  sulphide 
in  acid  solution.  Alkali  hvdroxides  separate  it 
from  all  metals,  giving  insoluble  hydroxides,  and 
ammonium  sulphide,  which  precipitates  thailous 
sulphide,  separates  this  metal  from  the  alkalis 
ana  alkaline  earths.  Gravimetrically,  thallium 
can  be  weighed  as  acid  sulfate  T1H!S04,  stable 
at  240^  and  as  sulphate  T1,S0«,  stable  at  low 
red  heat;  it  can  bs  precipitated  and  weighed 
as  iodide  TU,  platinichloride  Tl,Pta«,  and  ohro- 
ihate  Tl^CrO^.  Volumetrically,  it  can  be  esti- 
mated by  the  oxidation  of  thailous  salts  by  per- 
manganate or  by  titrating  with  thiosulphate  the 
iodine  set  free  in  accordance  with  the  following 
reaction:  TlCl,  -f  3K1  =  Til  +  SKQ  ■\- 1,  (Chem. 
Soc.  Proc  1908,  24,  76). 

Gbouf  IL 

Mercury  in  its  ores  is  generally  estimated  by 
distillation  with  quicklime  in  a  current  of  coal 
gas  or  carbon  dioxide.  The  decomposition  of 
the  mercury  compounds  is  facilitated  by  mixing 
copper  strips  with  the  quicklime,  and  the  pre- 
sence of  this  reducing  agent  is  essentia]  in  the 
case  of  mercuric  iodide.  The  mercury  which 
distils  over  is  collected  under  water,  wadied, 
dried,  and  weighed.  Ores  containing  only  small 
imounts  of  mercury  are  decomposed  by  heating 


Fio.  8. 

with  iron  filings  in  a  porcelain  crucible,  a,  having 
a  silver  lid,/,  which  is  cooled  by  a  water-jacket, 
6,  laid  upon  it.  The  mercury  condenses  on  the 
under  suriaoe  of  the  silver  plate,  /,  which  is 
weighed  before  and  after  the  experiment  (v. 
HoUoway,  Analyst.  1906,  31,  66). 

Mercury  is  separated  from  sdl  other  metals 
in  the  wet  way  by  dissolving  the  ore  or  alloy  in 
nitrio  acid  or  aqua  re^a,  duuting  considerably, 
precipitating  the  sulphides  of  Group  II.  by  hydro- 
gen sulphide,  removing  the  arsenic-tin  sub-group 
by  means  of  yellow  ammonium  sulphide  {noi 
sodium  sulphide  or  hydroxide),  treating  the 
residual  sulphides  with  dilute  nitric  add  (sp.^r. 
1-2-1*3),  and  dissolving  the  final  residue  in 
aqua  regia  and  filteringu  necessary  from  sulphur 
and  lead  sulphate.  The  mercury  can  be  re- 
precipitated  by  almost  neutralising  the  acid 
solution,  adding  in  succession  ammonium  sul- 
phide, caustic  soda  and'  ammonium  nitrate. 
The  caustic  soda  redissolves  the  sulphide  initially 
formed  as  the  soluble  double  sulphide  HgCSNa),, 
and  from  this  the  ammonium  nitrate  reprecipi- 
tates  mercuric  sulphide  in  a  form  suitable  tor 
collection.  The  precipitate  is  waahod  succes- 
sively with  water,  alcohol,  and  carbon  disulphide, 
dried  at  110*,  and  weighed  as  HgS.  (For  other 
methods  of  separating  mercury,  see  Jannasch, 
Zeitsch.  anors.  Chem.  1896,  12,  132,  and  369; 
and  Stabler,  Chem.  Zeit.  1907,  31,  616.) 

Lead  in  its  ores  and  alloys  is  usually  separated 
from  other  metals  by  dissolving  the  suoetance 
in  hydrochloric  or  nitric  acid,  or  if  necessary  in 


254 


ANALYSIS. 


a  miztnre  of  the  two  aoids  tad  eTaporating  down 
the  eolation  with  ralphnrio  acid  until  white 
fumes  aie  evolred.  The  mixture  is  then  oooled 
diluted  with  water,  and  the  lead  sulphate  quickly 
collected.  If  the  amount  of  lead  ia  small,  alcohol 
must  he  added  to  complete  the  precipitati<ML 
The  l^ad  sulphate  thus  obtained  is  freed  from 
silica,  stannic  oxide,  and  other  impurities  by 
dissolymg  it  in  an  excess  of  ammonium  or  sodhim 
acetate. 

When  separated  as  lead  sulphate,  the  lead 
can  be  estimated  yolumetrically  by  boiling  the 
precipitate  with  ammonium  carbonate  and  then 
disaolvmg  the  lead  carbonate  in  acetic  add.  The 
lead  is  thus  converted  into  lead  acetate  which  ii 
titrated  with  standard  f errocyanide  using  as  indi- 
cator drops  of  uranium  acetate  on  a  porcelain 
idate.  The  lead  may  also  be  reprecipitated  as  oxa- 
late from  the  acetate  solution  by  alkali  oxalate, 
the  washed  lead  oxalate  being  then  suspended 
in  dilute  sulphuric  acid,  and  titrated  with 
standard  permanganate.  From  the  solution  of 
the  sulphate  in  sodium  acetate  the  lead  can  be 
precipitated  as  chromate  by  potassium  dichro- 
mate.  The  chromate  w  dissolved  in  dilute  nitric 
acid,  and  reduced  with  methyl  or  ethyl  alcohol. 
The  solution,  rendered  ammoniaoal,  is  treated 
with  oxalic  acid,  when  lead  is  precipitated  and 
titrated  as  above  with  standard  permanganate  (v. 
Chem.  News,  1896,  73, 18  ;  J.  Amer.  Chem.  Soo. 
1896,  18,  737;  Zeitsch.  anaL  Chem.  1902,  41, 
663).  Lead  may  be  separated  from  copper  by 
electrolysing  a  solution  of  the  metals  in  dilute 
nitric  acid  with  a  weak  current  (O'fr-1'6  amperes 
and  1*4  volts),  when  the  lead  is  precipitated  as 
dioxide  on  the  anode  (a  platinum  dish  with  un- 
polished inner  surface). 

Bismuth  IB  separated  from  all  other  metals 
but  those  of  Qroup  II.  by  the  precipitation  of  its 
sulphide  by  hydroffen  sulphide  in  acid  solution. 
The  insoluoility  <n  the  sulphide  in  ammonium 
sulphide  separates  this  metal  from  arsenic,  anti- 
mony, and  tin.  The  further  separation  of  bis- 
muth from  mercury,  copper,  ana  cadmium  pre- 
sents no  particular  difficulty,  and  is  effected  bv 
taking  aavantagie  of  the  solubility  of  bismuth 
sulphide  in  nitric  acid  (sp-gr.  1-26),  and  the 
precipitation  of  bismutii  oxychloride  on  diluting 
considerably  an  acid  solution  of  bismuth  chloride. 
Hie  problem  of  separating  bismuth  from  lead 
is,  however,  much  more  troublesome,  and  the 
folio  wing  appear  to  be  most  trustworthy  methods : 
(i.)  the  separation  of  the  bismuth  as  basic  nitrate 
and  the  solution  of  lead  nitrate  in  dilute  am- 
monium nitrate  (J.  pr.  CShem.  1868,  74,  346) ;  (ii.) 
the  distillation  of  tne  mixed  sulphides  in  a  cur- 
rent of  bromine,  when  bismuth  bromide  is  volati- 
lised, leavinfl  behind  lead  bromide  (Jannasch, 
Praktischer  Leitfaden  der  QewichtsanalyBe,lBted. 
166);  (iii)  the  precipitation  of  bismuth  as  the 
basic  formate ;  a  repetition  of  this  operation  gives 
a  precipitate  free  from  lead,  which  is  dissolved  in 
dilute  nitric  acid,  the  solution  almost  neutralised 
with  sodium  carbonate,  and  the  bismuth  then 
finally  precipitated  and  weighed  as  phosphate 
BiPO«  (SUhler,  Chem.  Zeit  1907, 31,  616).  The 
lead  in  the  filtrate  from  the  formate  sepa- 
ration is  precipitated  as  sulphide,  converted  into 
sulphate,  and  weighed  as  such.  This  method 
of  separation  gives  accurate  results  (Little  and 
Cahen,  Analyst,  1910,  36,  301). 

Copper  is  separated  from  the  metals  of  Qroupa 


[  IIL,  IV.9  y.,  and  VL,  by  precipitation  as  sulphide 
by  hydrogen  sulphide  in  acid  solution.  In 
aJlo^s  and  ores  it  is  generally  separated  from 
antimony  and  tin  by  rendering  these  insoluble 
by  the  action  of  moderately  stoong  nitric  acid. 
If,  however,  the  sulphides  of  these  metals  and 
arsenic  are  present,  they  are  extracted  from  the 
precipitate  with  alkali  sulphides  (not  ammonium 
sulphide).  The  insoluble  residue,  containing  the 
sulphides  of  copper,  bismuth,  lead,  mercunr,  and 
cadmium,  is  treated  with  nitric  acid  {v.  Mercury 
and  Bismuth),  Copper  is  readily  separated 
from  bismuth  by  means  of  ammonium  carbonate, 
which  precipitates  basic  bismuth  carbonate, 
leaving  copper  in  solution.  The  separation  from 
cadmium  may  be  effected  by  one  of  the  following 
methods: — (1)  Hydrogen  sulphide  is  passed 
into  a  boiling  solution  of  the  sulphates  of  copper 
and  cadmium  in  dilute  sulphuric  acid  (1 : 4). 
The  precipitated  copper  sulphide,  which  contains 
some  cadmium,  is  ledissolved  in  nitric  add,  and, 
after  expelling  excess  of  the  solvent^the  predpi- 
tation  18  repeated.  (2)  The  copper  is  pred- 
pitated  as  cuprous  thiocyanate,  leaving  cadmium 
in  solution.  (3)  The  copper  is  converted  into 
potassium  cuprocyanide  K,Cu(CN)^,  with  a 
considerable  excess  of  potassium  cyanide,  and  the 
cadmium  precipitated  with  hydrogen  sulphide  or 
ammonium  sulphide  (compare  uso  Browning, 
Amer.  J.  8cL  1893,  [3]  46^  280). 

The  following  volumetric  processes  for  coppn 
are  employed  in  the  technical  analvsis  of  the 
ores  of  this  metal,  (i.)  The  mineral  is  dissolved 
in  hydrochloric  and  nitric  acids,  and  the  solution 
boiled  down  with  sulphuric  add  to  expel  the 
volatile  adds.  The  copper  is  precipitated  from 
the  boiling  solution  by  introdudng  a  i^eet  of 
aluminium  and  redissdlving  in  nitnc  add  with 
the  addition  of  bromine  to  destroy  nitrous 
fumes.  The  solution  is  neutralised  with  am- 
monia, addified  with  acetic  acid,  and  treated 
with  excess  of  potassium  iodide,  when  the  liber- 
ated iodine  is  titrated  with  standard  tiiiosul- 
phate  (Low,  J.  Amer.  Chem.  Soc.  1902,  24, 1082), 
(ii.)  A  solution  of  potassium  cvanide  is  standard- 
ised a^inst  pure  copper  foil  by  dissolving  the 
latter  m  nitnc  add,  adding  bromine,  boiling  to 
expel  nitrous  fumes  and  excess  of  bromine,  adding 
ammonia  till  strongly  alkaline,  and  titrating  with 
the  cyanide  solution  until  the  blue  tint  dis- 
appears. The  copper  ore  is  treated  as  in  (L),  the 
copper  being  precipitated  by  aluminium,  re- 
dissolved  in  nitnc  acid,  and  the  resultingsolution 
titrated  in  manner  just  described  (oTjSrearlev, 
Chem.  News,  1897  76, 189).  (For  other  methods 
of  separating  and  estimating  copper,  see  also 
Zeitsch.  anoiv.  Chem.  1896,  ii.  268 ;  Chem.  Soc 
Abstr.  1901,  li.  197 ;  J.  Amer.  Chem.  Soc.  1906, 
27,  1224;  Zeitsch.  anal.  CSiem.  1907,  46,  128; 
J.  Amer.  Chem.  Soc.  1908,  30,  760;  Chem.  Zeit. 
1908,  33,  263;  Amer.  J.  Sd.  1909,  (iv.)  27,  448.) 

(For  electrolytic  estimation  of  copper,  v. 
Electbo-ohxmiqal  Analysis.-) 

Cadmium  is  separated  from  the  other  metals 
of  Group  IL  by  the  methods  indicated  under 
copper,  tead,  Ak;.  In  the  presence  of  cine.  Fox 
recommends  precipitation  in  a  solution  con- 
taining trichloroacetic  acid  (Chem.  Soc.  Trans. 
1907,  91,  964).  Electrolytically,  cadmium  is 
deposited  from  a  cyanide  solution  (0-7-1  *2  amperva 
and  4*8-6  volts);  the  use  of  a  rotating  cathode 
accelerates    the    rate  of    depodtion    (compare 


ANALYSia 


Pkia,  Amw.  J.  8oL  1906,  70,20S  and  392;  ud  | 
Avery  and  Dales,  J.  Ainer.  Ghem.  Soc.  1887, 19^ 
379). 

Tin,  amUmony,  and  arsenie  are  separated 
from  the  remaining  metals  of  Group  IL  by 
digesting  the  group  precipitate  at  80*  with  con- 
centratM  yellow  ammonium  sulphide,  when  the 
sulphides  of  these  three  metals  dissolve,  leaving 
the  other  sulphides  insoluble.  Copper  sulphide 
is  appreciably  soluble  in  this  solvent,  and  m  the 
presence  of  copper  it  is  preferable  to  use  sodium 
or  potassium  sulphide,  but  in  the  presence  of 
mercury  these  reagents  are  inadmissible,  owing 
to  formation  of  the  soluble  double  sulphide 
Hg(SK)g.  In  the  presence  of  much  iMd  a 
small  amount  of  tin  is  retained  in  the  insoluble 
residue.  Arsenic  rarely  occurs  in  alloys,  and 
in  these  sabstanoes  antimony  and  tin  are 
separated  from  other  metals  as  insoluble  ozy- 
acids  (metantimonio  and  metastannio  acids)  by 
the  use  of  nitric  acid  as  solvent. 

Arsenie  is  separated  from  antimony  and  tin 
by  distillinfl  the  hydroch^ric  acid  solution  of 
the  three  cements  with  ferrous  chloride;  the 
arsenic  is  volatib'sed  as  arsenions  chloride ;  this 
compound  is  collected  in  cold  water  and  the 
arsenic  precipitated  as  trisulphide  (Fischer, 
Zeitsoh.  anaL  Chem.  1881,  21,  266).  Various 
modifications  of  this  method  have  been  intro- 
duced ;  the  distillation  is  carried  on  in  a  current 
of  hydrogen  chloride  and  hydroeen  sulphide, 
the  latter  serving  as  the  reducing  aoent 
instead  of  ferrous  chloride ;  the  volatiSsed 
arsenious  chloride  is  converted  in  the  cooled 
receiver  into  the  trisul^ide  (Piloty  and  Stock, 
Ber.  1897,  30, 1649).  (For  other  modifications, 
«ee  Gooch  and  Danner,  Amer.  J.  Soi.  1891,  [3] 
42,  308;  Andrews,  J.  Amer.  Chem.  Soc.  1895, 
17,  869;  Rohmer,  Ber.  1901,  34,  33;  Morgan, 
Chem.  Soc.  Trans.  1904,  85,  1001.) 

The  arsenic  may  also  be  separated  from  tin 
and  antimony  bv  dissolving  the  three  sulphides 
in  ammoniaoal  hydrogen  peroxide,  neutralisinff 
the  solution  with  mineral  acid,  acidifying  with 
tartaric  acid,  and  precipitating  the  arsenic 
as  magnesium  ammonium  arsenate  by  the 
addition  of  ammonia  and  magnesia  mixture 
(see  Qualitaiive  aTialysis). 

The  following  method  of  separating  arsenic 
and  antimony  in  their  ores,  leads  to  vol  n  metric 
processes  for  the  determination  of  these  elements 
(Low,  J.  Amer.  Chem.  Soc.  1906,  28,  1715).  The 
mineral  is  decomposed  by  heating  with  strong 
snlnhurio  acid  (20  parts)  containing  potassium 
hydro^n  sulphate  (1*4  parts),  and  1  part  of 
tartaric  add.  The  cooled  product  is  taxen  up 
with  350  C.C  of  hot  water,  10  c.c.  of  strong  hydro- 
chloric acid,  and  3  grams  of  tartaric  acid,  and 
the  solution  saturated  with  hydrosen  sulphide. 
The  mixed  sulphides  are  dissolved  in  aqueous 
potassium  sulphide,  and  the  filtrate  evaporated 
down  with  10  aa  of  strong  sulphuric  acid  and 
3  gnms  of  potassium  hydrogen  sulphate  until 
the  sulphur  and  the  greater  part  of  tne  free  aid 
are  expelled.  The  cooled  melt  is  dissolved  in 
50  O.C.  of  strong  hydrochloric  acid  and  25  ac. 
of  water,  and  arsenious  sulphide  prempitated 
by  hvdrrwen  sulphide.  The  antimony  remaining 
in  the  mtrate  is  precipitated  as  sulphide  by 
diluting  the  solution  and  passing  in  more  hydro- 
gen  sulphide.  The  antimonious  stilphide  is  again 
dissolved  in  potassium  sulphide,  the  solution 


evapoimtad  nearly  to  dryness  with  strong  sol 
phurio  acid  and  potassium  hydrogen  sulphate, 
the  melt  dissolved  in  dilute  hydrochloric  acid 
and  titrated  with  standard  permanganate. 

The  arsenious  sulphide  is  dissolved  in  warm 
ammonium  sulphide,  and  the  solution  heated 
strongly  with  strong  sulphuric  acid  and  potassium 
hydrogen  sulphate  until  all  the  sulphur  and 
nearlv  all  the  acid  are  expelled.  The  residue  is 
boiled  with  water  to  expel  sulphur  dioxide, 
neutralised,  and  titrated  with  standard  iodine 
solution  in  the  presence  of  sodium  bicarbonate. 

Arsenic  may  also  be  estimated  in  minerals 
(which  do  not  contain  phosphates)  by  fusing  the 
powdered  ore  with  sodium  carbonate  and  nitre 
or  sodium  peroxide,  extracting  the  fosed  mass 
with  water  and  precipitating  silver  arsenate 
from  the  neutralised  solution.  This  precipitate, 
is  redissolved  in  nitric  add,  and  the  amount 
of  silver  in  it  determined  by  standard  thio- 
cyanate;  whence  the  quantity  of  arsenic  pre- 
sent can  be  readily  calculated.  (For  other 
processes  for  the  estimation  of  arsenic  in 
technically  important  materials,  v.  Clark,  Chem. 
Soc.  Trans.  1892,  61,  424 ;  Friedhdm,  Zeitsch. 
anaL  Chem.  1905,  44,  665;  Heath,  Zdtsch. 
anorg.  Chem.  1908,  59,  87 ;  Gooch  and  Phelps, 
Amer.  J.  Sci.  1906,  (iv.)  22,  488 ;  McGowan  and 
Floris,  J.  Soc.  Chem.  Ind.  1905,  24, 265 ;  Sanger 
and  Black,  ibid.  26,  1115;  Collms,  Anal^ 
1912,  37,  229.)  (For  the  detection  and  estima- 
tion of  minute  quantities  of  arsenic,  v,  Absshic.) 

Separation  of  tin  and  antimony.  In  the 
absence  of  any  large  amount  of  lead  or  other 
metal  giving  a  sulphide  insoluble  in  am- 
monium sulphide,  tin  and  antimony  can  be 
separated  from  these  metals  by  means  of  this 
reagent,  but  if  lead  is  present  in  considerable 
amount  the  tin  is  never  completely  extracted, 
a  portion  always  remaining  in  the  insoluble 
residue.  In  this  case  it  is  preferable  to  separate 
out  the  tin  and  antimonv  oy  oxidising  them  to 
their  insoluble  hydrated  oxides  by  means  of 
nitric  acid.  These  oxides  when  fused  with 
caustic  soda  in  a  silver  crucible  yield  sodium 
stannate  and  antimonate;  the  latter  of  these 
salts  is  practically  insoluble  in  dilute  alcohol 
(1  vol.  alcohol,  2  vols,  water),  whilst  the  former 
is  readily  dissolved.  A  repetition  of  this  process 
with  the  insoluble  antimonate  leads  to  a  com- 
plete separation. 

When  present  as  sulphides,  these  metals  are 
conveniently  dealt  with  by  Henz's  modification 
of  Clark's  method.  The  sulphides  are  dissolved 
in  excess  of  aqueous  caustic  potash  containing 
potassium  tartoite;  the  solution  is  sradually 
heated  to  boiling  with  excess  of  30  p.c  nydroMn 
peroxide.  When  the  oxidation  of  the  sulphides 
IS  complete,  excess  of  oxalic  acid  is  added  (15 
srams  for  1  gram  of  mixed  metal),  the  liquid 
Boiled  to  destroy  excess  of  hydrogen  peroxide, 
and  hydrogen  sulphide  passed  for  some  time 
through  the  hot  solution.  The  precipitated , 
antimony  sulphide  is  dealt  with  as  described 
under  gravimetric  estimations.  The  filtrate 
is  treated  with  sulphuric  acid,  concentrated 
to  a  small  bulk  (150  cc),  and  dectrolysed 
at  60*  with  a  current  of  0*2-0*3  ampere,  and 
2*3  volts,  using  a  rotating  anode,  when  the  de- 
position of  the  tin  is  complete  in  about  one  houi 
(Henz.  Zeitsch.  anoiv.  Chem.  1903,  37,  1 ;  and 
Cahen  and  Morgan,  Analyst,  1909,  34,  3). 


256 


ANALYSIS. 


In  01ark*8  origizial  process  the  filtrate  from 
the  antimony  snKhide,  which  contains  stannic 
tin,  is  mixed  with  yellow  ammonium  sulphide  | 
in  excess  and  acidised  with  acetic  acid.  After 
some  time  the  stannic  sulphide  is  collected, 
washed  with  a  solution,  of  ammonium  nitrate, 
and  converlied  into  stannic  oxide  by  ignition. 
In  accurate  work  the  antimony  sulphide  ^  ia 
redissolved,  and  the  oxalic  acid  separation 
repeated  in  order  to  obtain  the  last  traces  of  tin 
(compare  Camot,  Compt.  rend,  1886,  103,  258). 
(For  descriptions  of  other  methods  of  estimating 
tin  and  antimony  in  their  ores  and  alloys,  see 
J.  Soa  Chem.  Ind.  1892,  11,  662;  G.  W. 
Thompson,  J.  Soo.  Chem.  Ind.  1896,  15,  179 ; 
T.  Brown,  jun.,  J.  Amer.  Chem.  Soc.  1899,  21, 
780;  Argenot,  ZeitsdL  angew.  Chem.  1904,  17, 
1274;  L^vy,  Analyst,  1905,30,361;  Panajotow, 
-  Ber.  1909,  42,  1296.) 

The  fdlowing  process,  due  to  Pearoe,  gives  a 
rapid  volumetric  method  for  estimating  tin  in 
its  ores.  The  mineral  is  fused  in  a  nickel  crucible 
with  about  20  parts  of  sodium  hydroxide  with 
the  addition  of  a  little  powdered  charcoal ;  the 
fused  mass  is  dissolved  (excepting  silica)  in 
hydrochloric  acid,  and  the  solution  reduced  by 
the  addition  of  iron  rods  or  sheet  nickeL  The 
stannous  chloride  thus  produced  is  titrated  with 
standard  iodine  solution  in  presence  of  suffi- 
cient hydrochloric  acid  (1  :  4)  to  prevent  the 
oxidation  of  any  arsenic  or  antimony  which  may 
be  present. 

Gold  and  platinum  are  separated  chiefly  in  the 
analytical  subgroup  containing  arsenic,  anti- 
mony, and  tin.  Fusion  of  the  sulphides  with 
sodium  carbcniate  and  nitre,  followed  by  extrac- 
tion with  water,  removes  the  arsenic.  The  residue, 
treated  with  zinc  and  hydrochloric  acid,  reduces 
tin  and  antimony  to  the  metallic  state ;  the  former 
is  dissolved  by  boiling  hydrochloric  acid,  and  the 
latter  by  nitnc  and  tartaric  acids,whilst  gold  and 
platinum  are  left.  Treatment  of  the  mixed 
metals  witih  chlorine  water  removes  gold,  and 
dilute  aqua  rtna  then  dissolves  platinum,  palla- 
dium, and  riiodium.  From  this  solution  platinum 
is  precipitated  by  ammonium  chloride  ana  alcohol, 
and  from  the  nitrate,  after  neutralisation  with 
sodium  carbonate,  palladium  is  precipitated  as 
cyanide  by  mercuric  cyanide. 

For    separation    of    palladium    from    gold, 

Slatinnm,  rhodium,  and  iridium  by  means  of 
imethylglyoxime,  we,  Wunder  and  Thuringer, 
(Zeitsch.  anal.  Chem.  1913,  62,  660 ;  Analyst, 
1913,  524). 

The  residue  from  the  aqua  regia  treatment  is 
roasted  in  the  air ;  osmium  volatilises  as  the 
tetroxide,  ruthenium  sublimes  as  the  dioxide, 
whilst  iridium  is  left  (v.  Leidi^,  Compt.  rend.  1900, 
131,  888  ;  and  Platinum  mktals). 

MtHybdenum  is  precipitated  as  sulphide  pre- 
ferably from  a  Bulpnuric  acid  solution  by  treat- 
ment with  hydrogen  sulphide  under  pressure. 
From  the  sulphides  of  the  copper-lead  suberoup, 
it  is  separated  by  digestion  with  sodium  sulphia6 
under  pressure,  when  the  molybdenum  passes 
into  solution  and  is  reprecipitated  as  sulphide 
by  dilute  sulphuric  acid.  Molybdenum  sul- 
phide is  separated  from  the  sulphides  of  anti- 
mony and  tm  by  dissolving  the  latter  in  hydro- 
chloric acid.  The  sulphides  of  arsenic  and 
molybdenum  are  dissolved  in  hydrochloric  acid 
and  potassium  chlorate,  the  arsenic  precipitated 


from  the  filtrate  after  adding  ammonia  and 
magnesia  mixture  as  magnesium  ammonium 
arsenate.  The  final  filtrate  is  acidified,  and  tiie 
molybdenum  reprecipitated  as  sulphide.  Moly- 
bdenum is  separated  from  phosphorus  in  a 
similar  manner.  From  tun^ten  it  is  best 
separated  by  heating  the  mixed  trioxides  or 
their  alkali  salts  at  250*-270''  in  a  current  of 
hydrogen  chloride,  when  the  molybdenum  is 
completely  volatilised  as  the  additive  com- 
pound MoO„2HGl,  while  the  tunssten  remains 
m  the  non-volatile  residue  (Debray,  Compt. 
rend.  1858,  46,  1101 :  and  Pechaixl,  ibid,  1892, 
114,  173). 

StUnium  and  tdLurium  fall  into  the  analy- 
tical sub-group  containing  arsenic,  and  after  tlm 
element  has  been  removed  as  magnesium  am- 
monium arsenate  (v.  ifo2y6<ief»«m),  the  selenium 
and  tellurium  are  precipitated  by  rednoing  agents 
such  as  sulphur  dioxide,  hydrazme,  &a  (L)  Sul- 
phur, selenium,  and  tellurium  are  separated  by 
fusion  with  potassium  cyanide  in  a  stream  of 
hydrogen.  On  dissolving  the  mass  in  water  and 
passing  air  throuffh  the  solution,  the  potassium 
teUuride  present  is  decomposed,  and  tellurium 
is  precipitated.  When  the  filtrate  is  acidified, 
the  potassium  selenocyanate  (KCNSe)  is  decom- 
posed, yielding  selenium,  (ii.)  The  mixed  di- 
oxides of  selenium  and  tellurium  are  dissolved 
in  aqueous  caustic  potash ;  the  solution,  faintly 
acidified  with  hydrochloric  acid,  is  diluted  to 
at  least  200  cc.  with  boilins  water,  rendefed 
just  ammoniacal  and  reaoidified  witii  aoetio 
acid.  After  30  minutes  the  tellurium  dioxide 
is  coUected,  washed  with  cold  water,  and  gently 
ignited  (Browning  and  Flint,  Zeitsch.  anoig. 
Chem.  1909,  64,  104). 

QM  from  all  other  metals :  reduction  of  an 
acid  solution  by  oxalic  acid  or  sulphurous  acid. 

Selenium  from  the  metals :  reduction  with  sul- 
phurous acid  in  hydrochloric  acid  solution. 

Gboup  III. — ^The  metals  of  Qronp  11^  are 
separated  from  those  of  the  succeeding  groups 
by  precipitation  with  ammonia  in  presence  of 
ammonium  chloride ;  the  metals  of  Uioup  Illb. 
are  separated  from  those  of  the  succeeding 
groups  by'  means  of  ammonium  sulphide  (v. 
General  methods  of  estimation). 

Iron,  aluminium,  chromium,  «rof»i«iii, 
glucinum,  and  cerium,  from  zinc,  manganese^ 
nickel,  ccbaU.  The  solution,  which  must  contain 
iron  and  uranium  as  ferric  and  uranic  salts,  is 
nearly  neutralised,  mixed  with  excess  of  finely 
divided  and  recently  precipitated  barium  car- 
bonate, and  allowed  to  remain  in  a  closed  vessel 
at  the  ordinary  temperature  for  some  hours 
with  occasional  agitation.  In  presence  of  niclDel 
and  cobalt,  ammonium  chloride  should  be  added 
to  prevent  precipitation  of  traces  of  these  metals, 
filter  and  wash  with  cold  water.  The  precipitate 
may  contain  ferric,cbromic,  aluminium, glucinum, 
cenc  and  uranic  hydroxides,  mixed  wiw  bsrium 
carbonate ;  the  filtrate  contains  the  other  metals, 
together  with  some  barium.  In  both  cases  the 
barium  can  be  removed  by  means  of  sulphurio 
acid,  but  as  the  barium  sulphate  carries  down 
small  amounts  of  the  other  metals,  it  is  re- 
ferable to  separate  the  metals  of  Groups  III. 
and  IV.  by  a  double  precipitation  with  am- 
monium sulphide  (Treadwell). 

Iron  and  aluminium  from  zinc,  manganese, 
nickel,  cobalt,  uranium,  and  metals  of  die  sue- 


ANALYSIS. 


257 


ceeUng  groups.  The  Bolation,  which  mnst  con- 
tain iron  as  a  ferric  salt,  is  nearly  neutraliaed  by 
■odium  or  ammonxnm  carbonate.  In  presence 
of  iron  the  tiqnid  becomes  deep  red,  bat  no 
precipitate  must  be  formed.  Sodium,  or,  better, 
ammonium  acetate,  is  added  in  sufficient  but 
not  excessive  quantity,  and  the  liquid  is  boiled 
until  the  precipitate  becomes  granular  and 
aetties  rapidly.  Prolonged  boiling  makes  the 
precipitate  slimy.  The  liquid  is  fitered  whilst 
ikot,  and  the  precipitate  is  washed  with  hot 
water ;  if  the  liquid  is  allowed  to  cool  the  pre- 
cipitate is  partially  redissolved.  The  precipi- 
tate is  converted  into  ferrip  and  aluminium 
oxides  by  ignition ;  the  other  metals  are  in  the 
filtrate.  It  is  advisable,  and  in  presence  of 
nickel  essential,  to  redissolve  the  precipitate 
and  repeat  the  process.  This  method  is  not 
available  for  the  separation  of  chromium. 

The  same  result  can  be  obtained  with 
ammonium  formate  or  snooinata  % 

Aluminium  and  chromium  from  iron,  tinc^ 
manganese,  nickel,  and  eobaU.  Mix  the  solution 
with  a  moderate  quantity  of  pure  normal  potas- 
sium tartrate,  then  with  pure  caustic  potash  or 
soda  until  the  pfeoipitate  redissolves,  add  am- 
monium sulphide  in  slight  excess  and  allow  to 
stand.  Waw  the  precipitate  with  water  contain- 
ing ammonium  sulphide.  Aluminium  and  chro- 
mium axe  in  the  filtrate,  the  other  metaJs  in  the 
precipitata  If  iron  and  chromium  are  absent, 
it  is  sufficient  to  add  the  alkaline  tartrate, 
excess  of  ammonia,  ammonium  chloride  and 
ammonium  sulphide. 

Beparaiion  o/  iron  and  aluminium.  The  fol- 
lowing methods  have  also  been  employed  for 
this  important  separation.  (L)  Potassium  hy- 
droxide dissolves  aluminium  hydroxide,  but  not 
feme  hydroxide;  the  former  is  reprecipitated 
from  the  ffitrate  by  boiling  with  ammonium 
ohkxride  or  adding  successively  nitric  acid  and 
ammonia;  the  iron  precipitate  is  dissolved  in 
aoid  and  reprecipitated  by  ammonia,  (ii.)  The 
two  metals  are  precipitated  with  ammonia  and 
the  weight  of  the  combined  oxides  determined. 
The  mixture  is  then  digested  with  strone  hydro- 
chloric aoid  (10  concentrated  solution  :  1  water) 
until  all  the  iron  has  dissolved ;  the  presence  of 
fjree  chlorine  or  hydriodio  acid  assisto  uie  solution 
of  the  ferric  oxide.  If  alumina  predominates,  it 
may  be  necessary  to  fuse  the  mixed  oxides  with 
potassium  pyrosulphate.  The  solution  is  satu- 
rated with  nydrogen  sulphide  to  reduce  the  iron 
to  the  ferrous  condition ;  the  excess  of  this  sul- 

6 hide  is  expelled  by  carbon  dioxide,  and  the 
quid  titrated  with  standard  permanganate. 
The  proportion  of  aluminium  is  determined  by 
difEerenoe.  (ill.)  Iron  and  aluminium  may  also 
be  separated  by  treating  the  mixed  chlorides 
with  strong  hydrochloric  acid  and  ether  (equal 
vols.);  the  aluminium  chloride  is  precipitated, 
collected,  washed  with  ethereal  hydrochloric 
acid  and  kpiited  with  mercuric  oxide  (Gooch  and 
Havens,  Amer.  J.  Sd.  1896,  2,  416).  (iv.)  The 
separatiim  of  small  quantities  of  aluminium 
from  excess  of  iron  has  been  successfully  effected 
by  the  use  of  phenylhydrasine.  The  iron  is 
first  reduced  to  the  ferrous  condition  by  adding 
hydrochlorio  acid  and  ammonium  bisulphite, 
and  the  solution  almost  neutraliaed  with  am- 
moniay  a  slight  excess  of  phenylhydrazine  Is 
tiien  added,  and  after  one  hour  the  aluminium 

Vol.  1.— y. 


hydroxide  is  collected  and  washed  with  a  solu- 
tion of  phenylhydraeine  sulphite.  In  this  way 
aluminium  can  be  separated  from  iron,  man- 
ganese, calcium,  and  magnesium  (Hess  and 
Campbell,  J.  Amer.  Chem.  Soo.  1899,  21,  776). 

aeparaiicn  of  iron,  aluminium,  and  phoS' 
photic  acid.  When  the  totel  amount  of  these 
substances  is  small,  the  precipitate  obtained  by 
ammonia  is  ignited  and  weighed  (AssFegO. 
+Al,Og-f-PsO,).  The  precipitate  is  then  fused 
with  sodium  carbonate  and  silica,  and  the  mass 
extracted  with  water  containing  a  little  am- 
monium carbonate.  The  residue  containing  iron 
and  aluminium  is  evaporated  doTWn  with  sul- 
phuric acid  to  dissolve  the  iron ;  the  solution  is 
reduced  with  hydrogen  sulphide  as  in  the  pre- 
ceding separation,  and  titrated  with  permanga- 
nate soluuon.  The  solution,  which  contains  all 
the  phosphoric  add,  is  evaporated  down  with 
hydix)chloric  acid  to  remove  silica ;  the  residue 
taken  up  with  water,  and  the  phosphoric  acid 
precipitated  from  the  filtrate  as  magnesium 
ammonium  phosphate.  From  the  weight  of 
magnesium  pyrophosphate  obtained  the  amount 
of  PiOa  is  determined,  and  the  Al^O,  is  obtained 
by  dinerenoe.  If  the  total  amount  of  these 
three  substances  is  large,  the  original  solution 
may  be  divided  into  three  ab'quot  portions,  in  one 
of  which  the  phosphoric  acid  is  precipitated  as 
ammonium  pnospnomolybdate,  in  the  second 
part  the  iron  is  determined  volumetrically,  and 
from  the  third  the  total  precipitate  (Fe,0|, 
Al,0,,PaO.)  is  obtained  (compare  Cooksey, 
Analyst^  1908,  33,  437). 

Chiromium  is  readily  separated  from  many 
metals,  e,g.  aluminium,  by  conversion  into 
chromate,  which  is  not  precipitated  by  alkalis. 
This  can  be  done  in  one  of  the  following  ways, 
(a)  Make  the  solution  alkaline  with  caustic  potash 
or  soda,  saturate  with  chlorine,  and  then  heat  to 
expel  excess  of  gas,  and  decompose  hypochlorites 
by  heating  with  ammonia.  (6)  Ammonium 
persulphate  is  added  to  a  solution  containing 
chromium,  iron,  and  aluminium.  On  boiling, 
the  chromium  is  oxidised  to  chromate,  the  acid 
eet  free  during  oxidation  being  sufficient  to  keep 
the  iron  and  sluminium  in  solution  (G.  v.  Knorre, 
Zeitsch.  anorg.  Chem.  1903, 16, 1097).  (For  the 
estimation  of  chromium  in  chromite  and  chrome 
steel,  see  Vc^metric  seeiion,) 

Aluminium  from  chromium.  After  chro- 
mium has  been  converted  into  chromic  acid,  the 
aluminium  may  be  precipitated  as  hydroxide 
or  as  phosphate  (v.  Deltimination  o/  metals). 
The  filtrate  is  aci^fied,  heated  to  boiling,  and 
sodium  thiosulphate  added  until  the  chromium 
is  completely /educed ;  it  can  then  be  estimated 
as  phosphate  in  the  same  way  as  aluminium; 
or  caustic  alkali  is  added  to  the  solution  of  the 
metals  until  tibie  predpitate  at  first  formed  re- 
dissolves.  Bromme-water  is  added  until  the 
green  colour  of  the  solution  is  changed  to  the 
yellow  of  a  chromate  solution.  The  liquid  is 
heated  to  boiling,  and  more  bromine-water 
added  drop  by  drop  to  precipitate  the  alumina 
in  a  non-gelatinous  form. 

Uranium  is  separated  from  the  other  metals 
of  this  group  by  the  solubility  of  its  hydroxide, 
sulphide,  and  acid  uranates,  m  ammonium  car- 
bonate. 

Uranium  from  Iron  and  Aluminium,  An  add 
solution  containing  ammonium  salte  is  mixed 

S 


258 


ANALYSIS. 


with  ezcefls  of  ammoniam  carbonate  and  am- 
monium sulphide  in  a  oloeed  flask.  The  pre- 
cipitate contains  ferrous  sulphide  and  alumimum 
hydroxide;  the  uranium  remains  dissolved  as 
the  double  carbonate  U0,C0-^(NH4),C0,. 
The  filtrate  is  concentrated  considerably,  acidi- 
fied with  hydrochloric  acid,  boiled,  and  the 
uranium  precipitated  as  ammonium  diuranate 
with  ammonia.  The  precipitate  is  ignited  and 
weighed  as  UaOa.  Or  this  oxide  is  heated 
with  dilute  sulphuric  acid  (1:6)  at  lYO  m  an 
inert  atmosphere  (carbon  dioxide) :  the  sjln- 
tion  which  contains  uranyl  sulphate  (2  mols.) 
and  uranous  sulphate  (1  mol.),  is  titrated  with 
standard  permanganate  solution. 

1  o.a  ^KMnO«»0-03693n. 

Uranium  ores  are  treated  in  the  followina 
way.  The  mineral  (0-5-1 -0  gram)  is  diasoked 
in  nitric  acid  or  aqua  regiop  sUioa  removed  bv 
evaporation,  the  soluble  residue  extracted  with 
hydrochloric  acid,  and  the  metals  of  the  copper 
ffroup  precipitated  b^  hydrogen  sulphidCb  The 
nitrate  is  oxidised  with  potassium  onlorate,  and 
treated  successivdy  with  ammonium  phosphate, 
ammonia  (tiU  nearly  neutral),  and  sodium 
carboniV]te  in  excess.  The  mixture  is  boiled  and 
sufficient  ammonium  chloride  added  to  decom- 
pose excess  of  sodium  carbonate.  The  preci- 
pitate, which  contains  the  iron,  vanadium,  Ac, 
is  washed  with  aqueous  ammonium  carbonate. 
This  salt  is  removed  from  the  filtrate  bv  boilinjs 
alone  and  with  nitric  acid.  The  solution  is 
almost  neutralised  with  ammonia,  and  to  the 
boiling  liquid  are  added  successively  micro- 
cosmic  salt,  sodium  thiosulphate,  acetic  acid, 
and  finally  ammonium  acetate.  The  precij^te, 
uranyl  ammonium  phosphate,  is  coUectiBd,  ignited, 
moistened  with  nitric  acid,  again  ignited  and 
weiffhed  as  (UOt),P,OY. 

Uranium  is  separated  from  thorium  (and 
iron)  by  means  of  hydroxylamine  hydrochloride, 
which  in  ammoniacal  solution  precipitates 
thorium  and  ferric  hydroxides,  leaving  the 
uranium  in  solution  (Jannasch  and  Schilling, 
Chem.  Zeit.  1905,  29,  248). 

Cerium  is  separated  from  oiher  melaU  by 
saturating  the  solution  wita  sodium  sulphate,  this 
salt  being  added  in  fine  powder.  A  crystalline 
double  s^phate  of  cerium  and  sodium  separates, 
and  is  washed  with  a  saturated  solution  of 
sodium  sulphate. 

Cfhdnum  is  precipitated  with  aluminium  in 
Group  IIL,  and  separated  from  aluminium  and 
tiie  other  metals  of  the  group  by  one  of  the 
following  methods:  (i.)  A  saturated  solution 
of  sodium  hydro|;eo  carbonate  dissolves  out 
glucinum  hydroxide  from  a  precipitate  con- 
taining siuminium  and  ferric  hydroxides,  leaving 
the  latter  unaffected  (Parsons  and  Barnes, 
J.  Amer.  CheuL  Soc.  1900,  28,  1589).  (iL)  Alu- 
minium and  glucinum  chlorides  are  separated 
by  saturating  theii  solutions  with  hydrogen 
chloride  in  the  presence  of  ether ;  the  former  is 
precipitated,  the  latter  remaining  dissolved 
(Amer.  J.  Sol  [41  11,  416).  (iii)  ThB  aoetotes 
may  be  separated  by  the  use  of  hot  glacial 
acetic  acid,  from  which  solvent  basic  glucinum 
acetate  G104(C0,-CH,),  [G10|(CH,C0,),]  sepa- 
rates  on  coohng  (Parsons  and  Robinson,  cf.  uso 
Glassmann,  Ber.  1900,  39,  3306 ;   and  J.  Amer. 


Chem.  Soe.  1895, 17,  688 ;  Wunder  and  Wpgner, 
Zeitsch.  anaL  Chem.  1912, 61, 470).  This  acetate 
is  soluble  in  chloroform  and  may  be  distilled 
unchanged.  Quantitative  results  may  be  ob- 
tained oy  volatilising  the  salt  from  the  basic 
acetates  of  iron  and  aluminium  (Kling  and 
Gelin,  BulL  Soc.  ohim.  1914,  15,  205 ;  Analyst, 
1914,  232). 

Barium  carbonate  decomposes  glucinum 
chloride,  thus  separating  tiiis  metal  from  those 
of  Group  Ulb. 

Vanadium  is  separated  from  the  majority  of 
metallic  elements  by  fusion  with  sodium  car- 
bonate and  potassium  nitrate;  the  vanadium 
dissolves  in  water  as  sodium  vanadate.  Chro- 
mium and  manganese  would  also  be  foflnd  in 
the  aqueous  extract,  but  from  these  metals 
vanadium  is  separated  by  the  addition  of  am- 
monium  sulphide  in  excess,  when  chromium 
and  manganese  are  precipitated  respectively  aa 
hydroxide  and  sulpnide  leaving  vanadium  in 
solfttion  as  a  thiovanadate  (of.  Zeitsch.  anorg. 
Chem.  5,  381;  Compt.  rend.  1904,  138,  810; 
and  Hillebrand,  Amer.  J.  Sci.  [4]  6,  209).  From 
arsenic,  vanadium  may  be  separated  either  by 
reducing  with  sulphur  dioxide  and  preoipitating 
arsenious  sulphide  with  hydrosen  smphide  or  by 
heating  the  mixed  sulphides  in  nydrogen  chlori<u 
at  15(r,  when  the  arsenic  is  volatuised  (Field 
and  Smith,  J.  Amer.  Chem.  Soc.  1896,  18, 1061). 

Vanadium  is  separated  from  phosphoric  acid 
by  reducing  vanadic  acid  to  a  hypovanadio  salt 
with  sulphur  dioxide,  and  precipitating  the 
phosphorus  as  phosphomolvbdate. 

Vanadium  and  molybdenum  are  separated 
by  the  action  of  hydrogen  sulphide  on  vanadio 
and  molybdic  acids  under  pressure,  moly- 
bdenum sulphide  being  precipitated,  or  am- 
monium metavanadate  may  be  precipitated  by 
the  action  of  excess  of  ammoniam  chloride 
(Gibbs,  Amer.  Chem.  J.  1S83,  5,  37|) ;  the  latter 
method  serves  to  separate  vanadium  from 
tunraten. 

(For  methods  of  estipaating  vanadium  in  iron 
and  steel,  see  Brearley  and  Ibbotson,  The 
Analysis  of  Steel  Works  liaterials;  and  Blair, 
The  Chemical  Analysis  of  Iron.) 

Tungsten  is  separated  from  the  majority  of 
other  elements  by  fusion  with  alkali  carbonate 
and  extraction  of  the  alkali  tunsstate  with 
water.  This  extract,  idien  acidified  with  nitrio 
acid  and  evaporated  to  dryness,  yields  tungstio 
acid  as  a  residue  insoluble  in  water.  From 
arsenic  and  phosphoric  acids  tungstio  aoid  is 
separated  by  the  addition  of  magnesia  mixture, 
which  predpitatet  the  arsenic  and  phosphorus, 
leaving  the  tungstate  in  solution  ((Sooch,  Amer. 
Caiem.  J.  1871,  1,  412;  and  Gibbs,  ibid.  1885, 
7,  337). 

The  tungsten  in  wolframite  may  be  estimated 
b;^  fusing  uie  finely  powdered  ore  (0'6  gram) 
with  0  parts  of  fusion  mixture  in  a  j^tinum 
crucible  for  half  an  hour.  The  fused  mass  is 
extracted  with  boiling  water  when  alkah  tung- 
state passes  into  solution  toaether  with  silicate 
and  stannate.  The  insolul&  rssidue  contains 
iron,  manganese,  calcium,  and  magnesium  with 
small  amounts  of  columbic  and  tantalio  aoids. 
The  filtrate  is  evaporated  to  dryness  with  excess 
of  nitric  acid,  ana  the  residue,  after  heating  at 
120^,  is  extracted  with  dilute  ammonium  nitrate 
solution ;  the  residue,  which  consists  of  tungstio 


ANALYSTS.  2B9 

oxide  wilh  fdlioa  and  stannic  oxide,  is  weighed  i  by    suspending    the    hydroxides    in    aqueous 


and  then  treated  with  hydrofluoric  aoid  and 
weighed  again.  This  second  readue  consists  of 
tungstio  oxide  and  stannic  oxide,  and  the  latter 
is  volatilised  by  heatins  repeatedly  with  am- 
mooinm  chloride  until  uie  weight  of  the  final 
residue  (WO,)  is  constant. 

To  remove  tin  the  mixed  oxides  may  be 


caustic  potash  and  passing  in  chlorine  until  the 
liquid  is  no  longer  alkaline.  The  cerium  remains 
precipitated  as  the  yellow  hydrated  dioxide^ 
whilst  the  other  hydroxides  are  disBolved 
(Mosander).  Various 'methods  have  been  pro- 
posed similarly  based  on  the  oxidation  of  cerous 
compounds  to  the  cerio  condition  (v.  Ann.  Qiem. 


ignited  with  zinc  powder,  and  the  residue,  after'  Pharm.  131,  369 ;  Monatsh.  1884,  0,  608;  Ber. 
extraction  with  hydrochloric  acid,  is  tungsten   35,  672). 

trioxide  (Angenot,  Zeitsch.  angew.  Chem.  19, '  Thorium^  together  with  the  rare  earths,  is 
140V.  separated  from  the  other  elements  by  oxalic 

^or  other  separations  of  tungsten  from  acid.  The  further  separation  is  effected  by  the 
its  usual  associates,  see  J.  Amer.  Chem.  Soa   following  methods : — 

1900,  22,  772 ;  Zeitsch.  anorg.  Chem.  1905,  45, '  (i.)  Monazite  sand  is  heated  with  concen- 
396 ;  Zeitsch.  anal.  Chem.  1908,  47,  37 ;  BulL  tratiMl  sulphuric  acid  at  180'*-200*  for  2  to  3 
Soc.  chim.  1908, 13,  892 ;  Wunder  and  Sohapira,  hours,  ana  the  product  taken  up  with  water,  and 
Ann.  Chim.  anaL  1913,  18,  257 ;  Marbaker,  the  rare  earthsprecipitated  by  the  addition  of 
J.  Amar.  Chem.  Soc.  1915,  37,  86.)  oxalic  acid.    The  precipitated  oxalates,  aft«r 

Caiundnum  and  femtoZum  are  extractea  washing  till  free  nom  phosphoric  acid,  are 
from  columbite  or  tantalite  by  fusing  the  ignited,  and  the  resulting  oxides  dissolved  in 
mineral  with  potassium  hydrogen  sulphate  and  h3rdrochloric  acid.  The  excess  of  acid  is  ex* 
extracting  the  fused  mass  with  hot  water  and  pelled  b^  evaporation  at  100%  the  residue  dis- 
hydrochloric  acid.  The  residue  is  treated  with  solved  m  water  and  treated  with  sodium 
ammonium  sulphide  to  remove  tin,  tungsten,  thiosulphate.  After  12  hours  the  solution  is 
and  SAain  extracted  with  hot  hydrochloric  acid,  boiled  for  10  minutes  and  filtered.  The  pre- 
The  maal  residue  is  then  dissolved  in  hydro-  oipitate  contains  thorium,  but  contaminated 
fluoric  acid,  the  filtered  solution  is  treated  with  with  cerium  ;  it  is  therefore  redissolved  and 
potassium  carbonate :  potassium  tantalofluoride  the  precipitation  repeated  until  the  filtrate  gives 
separates  in  acicular  crystals  and  the  mother  no  precipitate  on  ooiling  with  ammonia.  At 
liquor  furnishes  potassium  columbium  oxy-  this  stage  the  precipitate  is  ignited,  fused  with 
fluoride,  crystallising  in  plates  (compare  Weiss  sodium  hydrogen  sulphate,  the  product  dis- 
and  Landecker,  Zeitsch.  anorg.  Chemu  1909,  solved  in  water»  and  tne  thorium  finally  pred- 
64^  66 ;  and  Clieeneau,  Compt.  rend.  1909,  149,  pitated  with  oxalic  acid,  the  precipitate  being 
1132).  \]ffP*^  ^^  weighed  as  ThO,  (Fresenius  i^ 

Titanium.  In  addition  to  the  prooess  given .  Hints,  Zeitsch.  anal.  Chem.  35,  543). 
under  the  estimation  of  titanium,  this  element'  (iL)  The  mixed  oxalates  obtained  as  before 
may  be  separated  from  iron  by  the  following  from  the  monazite  sand  are  decomposed,  and 
methods :  (L)  By  adding  ammonium  sulphide  to .  the  metals  converted  into  nitrates  by  repeated 
an  alkaline  tartrate  solution  of  the  two  elements,  evaporation  with  nitric  acid.  The  neutral  solu- 
when  fexTous  sulphide  is  precipitated  (Gk>och,  tion  of  the  nitrates  is  diluted  with  aqueous 
Amer.  Chem.  J.  1885,  7,  283).  (ii.)  By  precipitat-  ammonium  nitrate  (10  p.c.)  warmed  to  80*, 
ing  titanic  acid  with  phenylhydrazine  (J.  Amer.  and  the  thorium  precipitated  as  peroxide  by  the 
Chem.  Soc  1895,25,421).  Titanium  is  separated  addition  of  pure  hydrogen  peroxide  solution. 
from  aluminium  by  boiling  with  an  alkali  acetate  The  precipitate,  wliich  contains  a  trace  of 
and  dilute  acetic  acid^  when  basic  titanium  cerium  peroxide,  is  filtered,  washed  with  aqueous 
acetate  is  precipitated.  ammonium   nitrate,    ignited   and   weighed   as 

Tikmivm  and  ttrconium  are  separated  by  ThO,  (Benz,  Zeitsch.  angew.  Chem.  1902,  15, 
the  following  methods :  (i.)  A  solution  of  the  297 ;  compare  Chem.  Zeit.  1908,  32,  509). 
elements  in  dilute  sulphuric  and  acetic  acids  is  ^  (iii)  Precipitation  by  organic  acids,  (a)  Fumaric 
boiled  for  some  time»  when  titanic  acid  is  preoi-  acid  precipitates  thorium  fumarate  in  40  p.o. 
pitated  (J.  pr.  Chem.  1869,  108,  75 ;  Zeitsch. ,  alcohol,  leaving  the  other  rare  earths  in  solution 
anaL  Chem.  9,  388).  (iL)  The  acid  solution  is  (Metzger,  J.  Amer.  Chem.  Soa  1902,  24,  901). 
boiled  with  zinc  till  the  titanium  is  reduced  to  {P)  m-Nitrobenzoic  add  in  aqueoua  solution 
titanous  salt,  the  zirconium  is  then  precipitated  precipitates  its  thorium  salt,  the  separation 
by  the  addition  of  potassium  sulphate  (Compt.  being  complete  in  the  presence  of  aniline. 
raid*  1868»  67,  298).  (iii.)  A  neuteal  solution  Under  these  conditions,  cerium,  praseodymium, 
of  the  nitratea  is  added  drop  by  drop  to  a  boiling  neodymium,  and  lanthanum  remain  in  solu- 
oomoentnted  solution  of  ammonium  salicylate  tion  (Kolb  and  Akele,  Zeitsch.  angew.  Chem. 
(1 :  6H,0),  the  solution  boiled   for  one   hour,    1905,  18,  92). 

conoentrated,  and  the  precipitated  zirconium  |  (iv.)  Boiling  with  potassium  azide  in  neutral 
salicylate  oolleoted  and  washed  with  am-  solution  leads  to  the  precipitation  of  thorium 
moninm  sslioylate  solution*  Titanium  sali-  j  hydroxide,  the  salts  of  the  other  rare  earth 
ovlate  IB  solume  in  hot  water  and  remains  in  '  metals  being  unaffected  (pennis,  J.  Amer.  Chem. 
the  filtrate  (Dittrich  and  Fieund,  Zeitsch.  anoig.  Soc.  1896^  18,  947).  Fusion  with  potassium 
Caiam.  1907,  66,  337,  348).  hydrogen  fluoride  separates  thorium  and  cerium 


Cerium  is  precipitated  in  the  aluminium 
group  (III.a),  and,  U^ther  with  the  other  metals 
of  the  rare  earths,  is  separated  from  iron  and 
aluminium  bv  means  of  oxalic  acid  or  am- 
monium oxalate.  From  lanthanum,  praseo- 
dymium, and  neodymium  it  may  be  separated 


from  zirconium,  for  on  extraction  with  water 
containing  a  little  hydrogen  fluoride,  potassium 
ziroonofluoride  dissolves,  leaving  benind  the 
fluorides  of  thorium  and  cerium  (Chem.  News, 
1897,  75,  230). 

Manganese  and  iron  arc  separated  in  their 


2fiO 


ANALYSIS 


alloys  (ferromanaranese,  &c.)  by  dissolving  the 
allojr  in  hydrocmorio  acid  witn  a  little  nitoio 
aoio.  After  boiling  o£f  nitrons  fnmes,  the  solu- 
tion is  filtered  ana  diluted  with  boUing  water 
to  600  O.C.  Ammonia  is  added  till  a  faint 
turbidity  remains,  excess  of  neutral  ammonium 
acetate  is  then  quickly  added,  and  the  solution 
boiled.  The  basio  ferric  acetate  thus  precipi- 
tated contains  some  manganese ;  it  is  theredPore 
redissolved  and  the  separation  repeated.  The 
united  filtrates  are  treated  with  excess  of 
bromine  followed  by  strong  ammonia  also  in 
excess ;  the  liauid  is  vigorously  acitated  durine 
the  addition  of  these  reagents,  and  then  heated 
slowly  to  boilinff.  The  precipitate  is  collected, 
washed  with  boOing  water,  ignited  and  weighed 
as  Mn,0,  (comparo  Biggs,  Amer.  J.  ScL  43, 136  ; 
Gooch,  Zeitsch.  anoig.  Chem.  1898,  17,  268; 
Brearley  and  Ibbotson.  Chem.  News»  1902,  82, 
209;  Zeitsch.  anaL  Chem.  1904,  43,  382 1 
Jannasch  and  Rfilil,  J.  pr.  Chem.  1906,  72,  1 ; 
Mooro  and  Miller,  J.  Amer.  Oiem.  Soo.  ]908» 
30,  693). 

Nickd  from  edbaU.  The  solution,  which 
should  contain  but  little  free  acid,  is  mixed  with 
excess  of  pore  potassium  cyanide  free  from 
cyanate  (the  ordinary  cyanide  is  fused  with  chju- 
coal,  dissolved  in  water,  filtered,  and  ev^mrated 
in  a  silver  dish),  heated  to  boiling,  ana  mixed 
with  a  solution  of  mercuric  osde  in  merourio 
cyanide.  The  precipitate,  when  washed,  dried, 
and  ignited,  leaves  a  residue  of  nickel  oxide 
NiO,  which  is  weighed.  Cobalt  is  usoally  deter- 
mined by  dififoronce;  but  if  direct  estimation 
is  roqniied,  the  filtrate  from  the  nickel  is  eva- 
porated to  dryness,  heated  for  some  time 
with  strong  suphurio  acid^  and  t^e  cobalt 
estimated  in  the  solution. 

Nickel  can  be  separated  from  cobalt  and  aU 
the  other  metals  of  Groups  IIL  and  IV.  by  pre- 
cijpitation  in  ammoniacai  or  dilate  acetic  acid 
solution  with  dimethvlglyoxime  {we  EstimoAum 
of  nickel).  If  ferric  salts  an  present,  they  should 
be  reduced  to  the  ferrous  condition,  or  tartaric 
acid  is  added  before  rendering  the  solution  alka- 
line )  fihe  oiganic  acid  provents  the  co-precipita- 
tion of  iron,  chromium,  and  aluminium  (BranQk* 
Zeitsch.  angew.  Chem.  1907,  20, 1846). 

CdbaUfromnickeL  (i.^  In  acetic  acid  solutiont 
nitroeo-i9-naphthol  precipitates  the  cobalt  as 
cobaltic  nitroao-i9-naphthoxide  (Jlinski  and 
Knorre,  Ber.  18, 699).  (iL)  Cobaltic  hydroxide  is 
preoinitated  from  a  neatral  solution  of  the  two 
metals  by  barium  carbonate  and  bromine  water 
(Taylor*  Proa  Manchester  Phil.  Soo.  1902,  46, 
(iL)  1).  (iii)  Small  quantities  of  cobalt  can  be 
detected  and  estimated  in  the  presence  of  nickel 
by  adding  to  a  neutral  solution  concentrated 
a<|ueous  ammonium  thiocyanate.  On  «hi>^lHng 
with  amyl  alcohol  and  ether,  these  oi«mic 
solvents  extract  the  double  salt  (NH4),Co((3^S)« 
(blue  solution),  leaving  the  nickel  in  the  aqueous 
solution  (Ber.  1901,  84,  2060  and  3913).  Zinc 
is  also  romoved  with  the  cobalt. 

Cobalt  is  precipitated  as  double  nitrite  on 
adding  potassium  nitrite  to  an  acetic  acid  solu- 
tion of  the  two  metals ;  the  nickel  is  left  in  solu- 
tk>n  (Fischer,  Pogg.  Aon.  72,  477 ;  and  Funk* 
Zeitsch.  anaL  Chem.  1907,  46,  1). 

The  solution  is  treated  with  ammonium 
chloride,  ammonia,  and  hydrogen  peroxide,  and 

med,  when  [Co(NH,)|a]aa  is  formed.    On 


neutralising  by  means  of  acid,  cooling,  and 
adding  excess  of  ammonium  molvbdate,  the 
cobalt  is  pieotpitated  as  CoaO.,10NH„6MoOs. 
This  is  washed  with  water  ana  dried  at  ll(r 
(CSamot,  Bull.  Soc.  chim.  1917  [iv.]  21,  211). 

SepanUion  of  zinc,  manganeee,  niehd,  and 
cobaU.  The  sUgntly  acid  solution  of  the  four 
metals  ia  treatM  with  sodium  carbonate  till  a 
permanent  precipitate  is  formed,  which  is  redis- 
solved by  a  few  drops  of  hydrochloric  acid; 
then  for  every  100  c.c.  of  liquid  16  drops  of  the 
same  acid  aro  added,  followed  by  10  cc.  of  20  p.a 
ammonium  thiocyanate ;  the  solution  heated  to 
70®  is  then  saturated  with  hydrogen  sulphide ; 
the  zinc  in  the  precipitate  is  determined  either 
as  sulphide  or  oxide.  Manganese  is  separated 
from  nickel  and  cobalt  by  passing  hydrogen 
sulphide  into  a  solution  of  their  saSs  in  acetic 
acid  containing  excess  of  ammonium  acetate, 
when  nickel  and  cobalt  are  precipitated  as 
sulphides ;  the  filtrate  may,  however,  slill  con- 
tain small  amounts  of  these  metals.  The  solu- 
tion is  concentrated,  treated  with  ammonium 
sulphide,  and  then  with  acetic  add.  A  further 
precipitate  of  nickel  and  cobalt  sul^dee  is 
thus  obtained  {v.  Treadwell  and  Cramers, 
Zeitsch.  anoig.  Chem.  1901,  26,  184 ;  compare 
J.  Soc.  Chem.  Ind.  1906,  24,  228 ;  BuO.  Boa 
Chim.  1908,  (iv.)  3,  114). 

Zinc  from  nickel  and  eobaU,  Add  excess  of 
pure  potassium  cvanide  and  precipitate  the  sine 
with  sodium  sulphide. 

Group  IV. — ^The  metals  of  this  ^up  aro 
separated  from  those  of  the  following  group 
by  precipitation  with  ammonium  carbonate  (v. 
General  methods  of  eslimation).  The  liquid 
is  first  made  alkaline  with  ammonia  and  after- 
wards heated  to  boiling  to  ensure  complete  pre- 
cipitation. 

Barium  from  calcium  and  etronHum.  The 
dilute  neutral  or  feebly  acid  solution  is  mixed 
with  excess  of  freshly  prepared  hydrofluosilido 
acid  and  one-third  its  volume  of  96  p.a  alcohol 
allowed  to  stand  twelve  hours,  collected  on  a 
weighed  filter,  washed  with  a  mixture  of  equal 
parts  of  water  and  alcohol,  and  dried  at  100*. 
Calcium  and  strontium  are  not  precipitated. 

Barium  from  etroniium.  Ammonium  bichro- 
mate and  ammonium  acetate  are  added  alter- 
nately to  a  solution  of  barium  and  strontium 
salts  containing  ammonium  acetata  After 
three  hours  the  precipitate,  BaOOt,  is  washed 
with  ammonium  acetate  solution,  dried  at  180-, 
and  weighed  (Eahan,  Analyst,  1908,  83,  12; 
V.  Zeitsch.  anal.  Chem.  1906,  44,  742 ;  J.  Amer. 
Chem.  Soa  1908,  30,  1827). 

Barium  and  etrxmiium  from  ealdum.  The 
solution  is  mixed  with  a  concentrated  solution 
of  ammonium  sulphate,  using  60  parts  of  the 
latter  salt  for  one  part  of  the  mixed  salts, 
heated  to  boiling  with  addition  of  a  small  quan- 
tity of  ammonia,  and  the  jxreoipitate  washed 
with  water  containing  ammonium  sulphata  The 
filtrate  contains  the  calcium,  which  can  be 
precipitated  by  ammonium  oxalata 

Calcium  from  strontium.  Convert  the  metals 
mto  nitrates,  evaporate  to  dryness,  and  extract 
with  a  mixture  of  equal  volumes  of  alcohol  and 
ether,  which  dissolves  caloium  nitrate  but  not 
strontium  nitrata 

Calcium  from  strontium  and  barium.  The 
nitrates  are  dried  at  140*  and  extracted  with 


ANALYSia 


tSl 


unyl  akohoI»  wluch  divolvea  out  the  calciam 
salt^  leaYing  the  other  two  undiaedlTed  (Brown- 
ing,  Amer.  J.  SeL  43»  60»  314). 

Calcium  from  wtagfunuwL  The  oakhim  is 
{oecipitated  by  ftminoiuam  ozaUte  (tu  I>eleniii- 
fudiom  cf  meial8\  adding  sufficient  of  this  ealt 
to  oonTert  both  metals  into  ozalatee»  since 
cakdnm  oxalate  is  amneciably  soluble  in  a  soln- 
tion  of  magnesiam  cUoride.  In  veiy  accurate 
separations  the  precipitate  should  be  filtered  off, 
redissolved  in  hydrochloric  acid,  and  reprecipi- 
tated  by  adding  excess  of  ammonia  and  a  small 
quantity  of  ammonium  oxalate  (c/.  Richards, 
ZeitBoh.  anorg.  Chem.  1901,  28,  71 ;  Zeitsch. 
angew.  Chem.  1908,  21,  692 ;  J.  Amer.  Gbem. 
Soc.  1909,  31,  917). 

Gbout  v. — ^Ifogiiemiiiii  from  alkaiia.  The 
magnednm  is  precipitated  with  ammonium 
l^iosnhate  in  the  usual  way,  the  filtrate  evapo- 
rated to  dryness,'  heated  to  expel  ammonium 
salts,  the  residue  evaporated  two  or  three  times 
with  strong  nitric  acid  to  romove  hydiochlorio 
add,  and  the  phosphoric  acid  removed  by  stannic 
oxide  (p.  Phoaphoric  acid  from  mkala;  v.  Gibbs, 
Amer.  J.  ScL  [31  5,  114;  Nenbauer,  Zeitsch. 
angew.  CSiem.  1896,  9,  439;  Gooch,  Zeitsch. 
anorg.  CSiem.  1899,  20»  121). 

In  solutions  free  from  ammonium  salts,  the 
maffnesium  can  be  mecipitated  as  magnesium 
hycooxide  by  the  addition  of  aqueous  barium 
hydroxide.  The  excess  of  barium  is  removed 
by  ammonium  carbonate  and  the  alkalis  aro 
determined  in  the  fillzate.  Magnesium  chloride 
Lb  also  separated  from  the  alluJi  chlorides  by 
isnition  with  mercuric  oxide,  when  mercuric 
chloride  and  the  excess  of  oxide  volatilise,  leaving 
magnesia,  from  which  the  soluble  alkali  chlorides 
are  readily  separated. 

AUboUs  from  magnesium,  (a)  The  solution 
is  made  distinctly  alkaline  with  puro  milk  of 
lime  (calcium  hydroxide  suspended  in  water) 
and  boiled  for  some  time,  oaro  beinff  taken  that 
it  remains  alkaline.  ^  The  liquid  is  filtered,  made 
alkaline  with  ammonia,  and  the  calcium  pre* 
cipitated  by  adding  ammonium  carbonate  and 
a  small  quantity  of  ammonium  oxalate.  The 
filtrate  is  acidified  with  hydrochloric  acid  and 
evaporated  in  a  weighed  platinum  dish,  heated 
to  expel  ammonium  salts,  and  the  alkaline 
chlorides  weighed.  They  should  dissolve  com- 
pletely in  water  and  should  give  no  precipitate 
when  mixed  with  ammonium  carbonate  and 
allowed  to  stand  for  some  time.  If  any  calcium 
is  present,  it  must  be  removed  by  repeating  the 
treatment  with  ammonium  carbonate  and 
oxalate. 

{b)  The  solution,  which  must  contain  only 
potassium,  sodium,  and  magnesium,  is  mixed 
with  excess  of  oxalic  acid,  evaporated  to  dryness, 
and  the  oxalic  acid  expelled  by  heating  carefully 
over  a  lamp  until  white  fumes  cease  to  come  off. 
The  residue  is  treated  with  water,  when  potas- 
sium and  sodium'  dissolve  as  carbonates,  whSst 
magnesium  oxide  remains  undissolved. 

Alkalis  from  sUieates,  (a)  The  finely  pow- 
dered silicate  (1  gram)  is  mixed  intimately  with 
an  equal  weiffht  of  ammonium  chloride  and 
eight  parts  of  dense  granular  calcium  carbonate, 
and  heated  to  redness  for  half  an  hour.  The 
product  is  boiled  with  water  in  a  platinum  or 
silver  dish  for  two  hours,  care  being  taken  to 
make  up  the  loss  by  evaporation,  the  liquid 


I  is  fihared  and  the  residue  well  washed  with  hot 
water.  The  filtrate^  which  contains  calcium  and 
the  alkalis,  is  treated  in  the  manner  just  de- 
scribed. In  this  method  of  decomposition^ 
which  IB  due  to  J.  Lawrence  Smith,  the  silicate 
is  decomposed  by  the  oakium  oxide,  which  is 
dissolved  by  the  fused  calcium  ddoride  formed 
by  the  action  of  the  ammonium  chloride  on  the 
calcium  carbonate. 

(6)  The  silicate  is  treated  in  a  platinum  dish 
with  excess  of  sulphuric  and  hydrofluoric  acids, 
and  the  mixture  evaporated  on  the  water-bath 
untfl  the  mineral  is  aitirdy  decomposed.  The 
temperature  is  then  raised  to  dnve  off  the 
greater  part  oi  the  sulphuric  acid,  and  the 
cooled  residue  extracted  with  water.  The  sul- 
phates are  converted  into  chlorides  by  barium 
chloride,  the  metals  of  Groups  III.  ana  IV.  pre- 
cipitated by  ammonia  and  ammonium  carbonate, 
the  magnesium  removed  by  barium  hydroxide, 
and  the  excess  of  this  reagent  eliminated  by 
ammonia  and  ammonium  carbonato.  The  alkali 
chlorides  remaining  in  the  final  filtrate  are 
estimated  as  indicated  in  the  foDowin^  section. 
Certain  native  silicates  of  the  andalusite  group 
are  not  decomposed  completely  by  this  treat- 
ment with  hydrofluoric  acid;  these  minerals 
may,  however,  be  broken  up  by  ignition  with 
ammonium  fluoride. 

(c)  The  alkali  and  other  metak  contained  in 
a  refractory  silicate  may  be  separated  by  heat- 
ing the  mineral  with  lead*  carbonate.  The  pro- 
duct is  extracted  with  nitric  acid;  Uie  lead 
removed  as  chloride  and  sulphide,  and  the 
metals  in  solution  dealt  with  in  tiie  customary 
manner  (Jannasoh,  Zeitsch.  anorg.  Chem.  1895, 
8*364). 

{d)  Silicates  of  different  typstf  are  decomposed 
by  fusion  with  boric  anhydride  followed  by 
extraction  with  methyl  alcoholic  hydrogen 
chloride  and  evaporation  to  remove  the  boric 
acid  as  volatile  methyl  borate  (Ber.  1895,  28, 
2822 ;  Zeitsch.  anorg.  Chem.  1896»  12,  208). 

Potassium  from  sodium.  The  metals  are 
converted  into  chlorides,  which  are  evaporated 
to  dryness  and  weighed  tosether  after  dryins  at 
150^.  The  salts  aro  dissolved  in  water,  mixed 
with  platinic  chloride  in  sufficient  quantity  to 
convert  both  into  platiniohlorides,  and  evapo- 
rated nearly  but  not  quite  to  dryness.  The 
residue  is  then  treated  with  alcehol,  which  dis- 
solves the  sodium  but  not  the  potassium  salt 
iv.  Potassium),  If  the  mixture  is  evaporated  to 
complete  dryness  and  heated  so  that  tne  sodium 
platiniohloride  becomes  anhydrous,  it  dissolves 
with  difficulty  in  alcohoL  Under  some  condi- 
tioiks  reversion  takes  place  and  sodium  chloride 
separates  in  white  crystals  insoluble  in  alcohol. 
In  this  case  the  alcohol  is  very  carefully  evapo- 
rated and  the  residue  again  treated  with  fdatinic 
chloride. 

In  order  to  separate  small  quantities  of  po- 
tassium from  large  quantities  of  sodium,  advan- 
tage may  be  taken  of  the  fact  that  potassium 
emoride  is  more  soluble  than  sodium  chloride 
in  strong  hydrochloric  acid  (Zeitsch.  analyt. 
Chem.  1880,  156).  The  dry  mixed  chlorides  aro 
thoroughly  moistened  with  concentrated  hydro- 
chloric acid :  2  ao.  of  the  acid  is  then  added, 
I  and  the  salt  thoroughly  crushed  and  stirred  with 
a  g^asB  rod.  After  standing  for  a  few  minutes 
the  acid  is  poured  off  into  a  small  dish.    Ten 


262 


ANALYSIS. 


repetitionA  of  this  treatment,  using  2  0.0.  of 
aoid  each  time,  wul  sumoe  to  remove  all  potag- 
ffinm,  whilst  the  greater  part  of  the  sodium 
chloride  is  not  dissolved.  The  acid  solution  is 
evaporated  to  dryness  and  the  potassium  deter- 
mined as  platinichloride  (CheoL  Soc.  Trans.  39, 
506).  B^  adopting  this  plan  much  less  platmio 
chloride  is  required,  and  the  separation  is  much 
moT%  accurate. 

Lithium  from  sodium  and  potoMtum.  When 
a  lithia-containing  silicate  (e.^.  lepidolite)  is 
broken  up  bv  one  of  the  preceding  processes 
the  preoipitable  metals  of  Groups  L-IV.  are 
first  removed  and  the  alkali  metals  converted 
into  chlorides.  The  combined  chlorides  are 
dried  and  weighed ;  potassium  is  estimated  in 
one  portion,  and  in  a  second  portion  the  lithium 
is  estimated  by  extracting  the  chlorides  with 
amyl  alcohol,  or  better,  Mobutyl  alcohol,  or 
witn  ether-alcohol  saturated  with  hydrogen 
chloride.  Anhydrous  lithium  chloride  is  soluble 
in  these  media,  whereas  sodium  and  potassium 
chlorides  are  practically  insoluble  therein  (c/. 
Winkler,  Zeitsch.  anal.  Chem.  1913,  62,  628; 
AnaljTst,  1913,  561 ;  Palkin,  J.  Amer.  Chem. 
Soc.  1916, 38, 2326  ;  Analyst,  1917, 54).  Lithium 
chloride  has  also  been  separated  from  the 
chlorides  of  the  other  alkali  metals  and  barium 
by  dissolving  it  in  boiling  pyridine,  in  which  the 
others  are  insoluble  (KaUenD^  and  Krauskopf, 
J.  Amer.  Chem.  Soc.  1908,  30,  1104;  Skinner 
and  Collins,  J.  Soc.  Chem.  Ind.  1913,  32,  214). 
(For  the  separation  of  lithivm  as  phosphate  and 
fluoride.  Bee  Ann.  Chim.  Phys.  98,  193 ;  Frdl. 
29,  332,  and  Analyst,  16,  209.) 

Rubidium  and  coesium  are  separated  from 
each  other  ai)4  frompotassium  by  taking  advan- 
tage of  the  difference  in  the  solubility  of  their 
platinichlorides.  Rubidium  hydrogen  tartrate  is 
more  than  nine  times  less  soluble  than  the 
craum  salt.  Csesium  carbonate  alone  of  the 
alkali  carbonates  is  soluble  in  alcohol.  Caesium 
sives  rise  to  a  series  of  sparingly  soluble  per- 
halides  and  yields  double  chlorides  with  lead  and 
antimony  cnlorides  {v.  Wells,  Amer.  J.  ScL  43, 
[3]  17;  and  Amer.  Chem.  J.  1901,  26,  265). 
The  metals  may  also  be  separated  by  taking 
advantage  of  tne  different  solubilities  of  their 
respective  alums,  particularly  of  their  iron  alums 
(Browning  and  Spencer,  Amer.  J.  Sci.  1916,  42, 

279). 

Ammonium  ealis  can   be  removed  from  a 

solution  in  two  ways:  (1)  By  evaporating  to 
diyness  and  carefully  heating  over  a  lamp  until 
all  fumes  cease  to  come  off.  (2)  By  concen- 
trating the  solution  and  heating  for  some  time 
with  excess  of  strong  nitric  acicL  When  evolu- 
tion of  oxides  of  nitrogen  ceases,  the  liquid  is 
evaporated  to  complete  dryness  and  the  nitrates 
converted  into  chlorides  by  repeated  treatment 
with  hydrochloric  acid  if  necessary. 

B.  The  Estimation  of  Acid  Radicals. 
Bromine  from  ehkrine,  (a)  The  two  ele- 
ments are  precipitated  by  excess  of  silver  nitrate 
and  wei^hMl  together.  The  filter  ash  is  removed, 
the  precipitate  cautiously  heated  to  fusion,  and 
a  portion  poured  into  a  weighed  porcelain  boat. 
The  boat  is  aeain  weighed,  heated  to  fusion  in 
a  current  of  axy  chlorine  in  a  glass  tube  until 
^I1  bromine  is  expelled,  and  the  silver  chloride 
rmed  is  weighed.    It  is  advisable  to  heat  in 


chlorine  for  a  farther  period  of  ten  minutes  and 
weigh  again.  I^e  loss  of  weight  multfolied  by 
4*223  gives  the  amount  of  silver  bromiae  in  the 
weight  of  precipitate  treated  with  chlorine,  from 
which  the  quantity  in  the  whole  precipitate  is 
readDy  calculated  (o.  Indirect  methods  of  de- 
terminaiion). 

This  method  gives  accurate  results  if  the 
proportion  of  btomine  is  not  too  smalL  When 
a  small  quantity  of  bromine  is  mixed  with  a 
large  quantity  of  chlorine,  the  former  may  be 
concentrated  by  taking  advantage  of  the  fact 
that  if  a  limited  quantity  of  silver  nitrate  is 
added,  the  precipitate  will  contain  all  the  bro- 
mine, but  only  a  portion  of  the  chlorine^  In  oiiO 
Sortion  of  the  substance  the  two  elements  are 
etermined  together  by  complete  precipitation. 
Anottier  portion  in  somewhat  dilute  solution  is 
mixed  with  a  quantity  of  silver  nitrate  insuflS- 
cient  for  complete  precipitation,  and  allowed  to 
stand  in  the  cold  for  some  time  with  repeated 
agitation.  The  precipitate  is  collected,  washed, 
and  weighed,  and  the  proportion  of  bromine 
determined  in  the  manner  already  described. 
The  quantity  of  silver  nitrate  which  should  be 
used  depencu  upon  the  relative  proportions  of 
chlorine  and  bromincb  H  one  part  of  bromine 
is  present  for  every  1000  parts  of  chlorine,  one- 
fifth  or  one-sixth  of  the  silver  necessary  for  com- 
plete precipitation  should  be  used ;  it  one  part 
to  10,000,  onlv  one-tenth ;  if  one  part  to  100,<X)0, 
only  one-sixtietii  (Fehling). 

{b)  The  solution  of  tne  two  halides  heated 
at  70*-80*  is  treated  with  ammonium  persul- 
phate, and  the  liberated  bromine  volatilised  in  a 
current  of  air,  collected  in  sulphurous  acid,  and 
estimated  as  silver  bromide  (Engel,  Compt.  rend. 
1894,  118,  1263). 

Iodine  is  separatml  from  chlorine  in  exactly  the 
same  way  as  bromine  from  cldorine.  The  loss  of 
weieht  on  treating  with  chlorine,  multiplied  by 
2*5o9,  gives  the  weight  of  silver  iodide  in  the 
portion  of  precipitate  taken. 

Iodine  from  chlorine  or  bromine.  The  solu- 
tion is  slightly  acidified  with  hydrochloric  acid, 
mixed  with  palladious  chloride  until  precipi- 
tation is  complete,  and  allowed  to  stand  in  a 
warm  place  for  twenty-four  or  forty-eight  hours. 
The  precipitate  of  jialladious  iodide  Pdl,  is 
collected  on  a  weighed  filter,  washed  with  warm 
water,  and  dried  at  100*,  or  is  reduced  by  heating 
in  hydrogen  and  the  metal  weiehed. 

Iodine  can  also  be  liberatea  by  nitrous  aoid 
and  estimated  volumetrically  (o.  Volumetrie 
methods). 

Bromine^  chlorine,  and  iodine  from  om 
another,  (a)  The  three  elements  are  precipi- 
tated and  weighed  together  in  one  part  of  toe 
solution.  In  another  part  the  iodine  is  sepiarated 
as  paUadious  iodide  by  palladious  chloride,  or 
better,  nitrate;  the  excess  of  palladium  is 
removed  by  hydrogen  sulphide  and  excess  (^ 
the  latter  by  ferric  sulphate ;  and  the  chlorine 
and  bromine  in  the  filtrate  are  precipitated  com- 
pletely or  fractionally  and  the  bromine  deter- 
mined in  the  manner  previously  described.  The 
chlorine  is  estimated  by  difference. 

(6)  A  direct  method  of  estimating  the  three 
halogens  in  a  mixture  of  their  solubfo  salts  has 
•  been  investigated  by  Jannasch  and  his  colla- 
borators.   The  process  in  its  present  stage  of 
.  development  gives  a  sharp  separation  of  chlorine 


AXALTSia 


aad  iodine,  bat  the  zesnlts  for  bromine  are 
Father  low.  The  miztore  diaeolvedi  hi  25  cc 
of  water  is  heated  to  boilinff  with  acetic  aoid 
and  hydrogea  peroxide,  and  the  liberated  iodine 
expelled  by  a  current  of  carbon  dioxide.  The 
bromine  is  then  liberated  by  adding  excess  of 
hydrogen  peroxide  and  moderately  strong  sul- 
phuric acid  (5 :  3).  The  iodine  is  collected  in 
an  ammoniaeal  solution  of  hydrazine  sulphate 
and  the  bromine  in  alkaline  hydrazine  sulpbate. 
After  acidifying  with  nitric  acid,  the  iodine  and 
bromine  are  precipitated  as  silver  salts,  and  the 
oUorine  left  in  the  distilling  flask  is  similarly 
raecipiUted  (Ber.  1906,  39,  196,  3656 ;  J.  pr. 
Chem.  1908,  78,  29;  Zeitach.  anoig.  Chem.  1, 
144  and  245).  (For  other  processes  for  sepa- 
rating the  halogens,  see  VUMmetrie  tedion ;  and 
Monatsh.  13,  1 ;  Chem.  Soc  Trans.  1893,  63, 
1051 ;  Oompt.  rend.  1898,  126,  187 ;  Ber.  1899, 
32,S615w) 

SeTeral  indirect  methods  of  estimating  these 
three  elements  in  a  mixture  have  been  pro- 
poeed.  They  are  baaed  on  the  methods  gi?en, 
together  with  the  fact  that  the  radicals  may  be 
precipitated  exactly  by  a  standard  solution  of 
silver  nitrate  and  the  precipitate  weighed,  the 
proportion  of  silver  and  haudes  in  tiie  precipi- 
tate being  thus  determined  («.  Fresenius, 
Quantitative  Analysis,  sect.  5). 

Indired  Methods  ef  Dtterminaiian.  This 
estimatum  of  two  or  three  halogens  in  a 
mixture  furnishes  a  good  example  of  indirect 
methods  of  analysis,  which  are  adopted  in  those 
cases  where  the  separation  of  two  or  more 
constituents  is  either  impossible  or  inconvenient. 
The  calculation  of  the  relative  proportions  of 
these  constituents  becomes  possiole  when  one 
can  obtain  as  many  independent  relationships 
as  there  are  radicals  to  oe  determined.  The 
estimation  of  chlorine  and  bromine  (a)  is  a  case 
in  point.  The  loss  of  weight  due  to  the  replace- 
ment of  Br.(79-92)  by  01(35-46)  is  proportional 
to  the  amount  of  bromine  present.  Let  w  a 
loss  of  weight.    Now 

CI 

Fr 


35-46       ,.  -.        36-46^ 

and  hence  Br  —  .^-^c^rBr  —  w; 


79-92  "      79-92 

or  Br  a  1-797  to :  t.e.  the  loss  of  weisht  multi- 
plied by  1-797  gives  the  quantity  of  bromine 
present. 

Similarly,  the  halogens  in  a  mixture  of 
soluble  chloride,  bromide,  and  iodide  can  be 
calculated  from  the  following  data:  (i.)  the 
amount  of  iodine  present,  set  free  by  nitrous 
acid  or  hydrogen  peroxide  and  acetic  aoid ; 
(ii.)  the  total  weight  of  mixed  silver  halides 
obtained  from  a  known  amount  of  mixturo; 
(iiL)  the  silver  required  for  the  complete  pre- 
cipitation of  the  three  halogens ;  this  is  obtamed 
volumetrioally.  The  indirect  method  can  also 
be  applied  to  the  estimation  of  sodium  and 
potassium  contained  in  the  mixed  chlorides 
nom  a  silicate  analysis  (v.  supra).  The  data 
required  are:  (i.)  the  weight  A  of  mixed 
chlorides ;  (ii.)  the  weight  B  of  chlorine  therein 
contained,  this  amount  being  determined  either 
sravimetrically  or  volumetrioally.  Let  x  and  y 
be  the  amoimts  of  potassium  and  sodium 
respectively,  then  these  quantities  aro  readily 
calculated  from  the  following  equations,  where 
Gl,  K,  and  Na  represent  the  atomic  weights  of 
these  elements. 


«+y-A-B 

CI   ^Cl        ^ 

These  indirect  methods  give  useful  rraults 
only  when  the  atomic  or  molecular  weiffhU  of 
the  two  radicals  differ  considerably,  and  when 
the  quantities  present  aro  approximately  equal. 
Moreover,  the  results  aro  al&cted  to  a  cbnsider- 
aUA  extent  by  comparatively  small  experi> 
mental  errors. 

Cyanids  from  eiUorule.  Silver  nitrate  is 
added  in  excess  to  an  approximately  2  p.c. 
solution  of  soluble  cvanide  and  chloride.  An 
excess  of  normal  nitric  acid  is  now  added,  and 
the  mixturo  containing  the  freshly  precipitated 
silver  salts  is  distilled,  iHien  hydrocyanic  acid  is 
expelled  quantitatively  and  estimated  in  the 
distillate  by  precipitation  as  silver  cyanide  with 
acidified  silver  nitrate,  drying  this  precipitate 
atllO*,  and'weighlnff  in  a  Gooch  crucible  or  on 
a  tared  filter  paper  (Plimmer,  Chem.  Soc.  Trans. 
1904,  85»  12;  comparo  also  Richards  and 
Sinoer,  Amer.  Chem.  J.  1902,  27,  205). 

Fhosphoric  acid  from  mefaitf.  (a)  The  nitric 
acid  solution,  as  free  as  possible  from  hydro- 
chloric aoid,  and  free  from  silicic  and  arsenic 
acids,  is  mixed  with  excess  of  a  solution  of  am- 
monium molybdate  in  nitric  acid,  heatod  gently 
for  a  few  minutes,  and  filtered  after  standing  for 
a  short  time.  The  precipitate  is  washed  with 
dilute  nitric  aoid,  dissolvea  in  ammonia,  and  the 
phosphoric  acid  precii^tated  by  magnesia 
mixture.  This  metnod  is  moro  esjpecially  ap- 
plicable when  the  quantity  of  phosphoric  aoid 
2s  relatively  small.  To  prepare  ammonium 
molybdate  solution,  25  grams  of  the  salt  is  dis- 
solved in  100  CO.  of  dilute  ammonia,  and  the  solu- 
tion poured  gradually  with  constant  and  vijKorous 
agitation  into  500  cc  of  a  mixturo  of  S  voU. 
B&ong  nitric  acid  and  1  vol.  water.  The  liauid 
is  heated  at  50*  for  some  time  and  the  dear 
solution  drawn  off. 

(6)  By  stannic  oxide  The  nitric  aoid  solu- 
tion is  concentrated,  mixed  with  fuming  nitric 
aoid  boiling  at  86*,  heated  gently,  and  granulated 
tin  added  gradually  in  quantity  not  less  than 
four  times  the  amount  of  phosphoric  acid  pre- 
sent. The  stannic  oxide  produced  forms  an  in- 
soluble compound  with  the  phosphoric  acid. 
This  is  filtered  off,  washed  with  hot  water,  dis- 
solved in  caustic  potash,  the  solution  saturated 
with  hydrogen  sulphide,  acidified  with  aootio 
acid,  and  the  stannic  sulphide  removed.  The  fil- 
trate is  concentrated,  any  stannic  sulphide  whioh 
separates  subseq^uentl^  is  removed,  and  the 
phosphoric  acid  is  estimated  in  the  usual  way. 
The  original  filtrate  from  the  stannic  oxide  con- 
tains the  metals  previously  combined  with  the 
phosphoric  acid. 

(c)  The  nearly  neutral  solution  is  mixed 
with  silver  nitrate  and  digested  for  some  time 
with  excess  of  silver  caroonate.  The  phos- 
phoric aoid  separates  as  silver  phosphate,  the 
metals  remain  in  solution  with  the  excess  of 
silver  nitrate.  The  silver  is  removed  by  hydro- 
chloric acid. 

(d)  When  the  phosphoric  aoid  is  combined 
with  metals  whioh  form  phosphates  insoluble  in 
water  but  soluble  in  acctio  acid,  the  solution 
is  nearly  neutralised,  mixed  with  sodium  or 
ammonium  acetate,  and  a  slight  excess  of  ferric 
chloride  containing   a   known   weight  of   iron 


£64 


ANALYSIS. 


added.  Tho  liquid  is  heafced  to  boiling,  the 
mixture  of  ferric  phosphate  and  basio  aoetate 
washed  with  hot  water,  dried,  and  heated  in  a 
platinum  crucible  until  the  weight  ia  constant. 
The  weight  of  the  precipitate  mtnus  the  known 
weight  of  the  ferric  oxide  ^ves  the  phosphoric 
anhydride  PfOf.  The  precipitate  may  be  mois- 
tened with  nitnc  acid  before  the  final  ignition. 

Phoaphorie  acid  in  atUcatea.  In  the  analysis 
of  silioateB  (v.  iupra)  the  phosphoric  acid  is 
found  together  witii  iron  and*  aluminium  in  the 
precipitate  produced  by  ammonia  in  the  filtrate 
from  the  silica.  This  mixture  is  analysed  in 
accordance  with  the  method  indicated  under  the 
separations  of  metals  (Group  IIL). 

Phosphorus  and  silicon  in  iron  and  sUd.  The 
iron  or  steel  borings  are  dissolved  in  nitric  acid 
(lEQ^Os  sp.gr.  1-4 :  1H,0) ;  the  solution  eva- 
porated to  dryness,  and  the  residue  ignited 
carefully  until  all  the  ferric  nitrate  is  converted 
into  ferric  oxide.  The  ignited  residue  is  dis- 
solved in  concentrated  hydrochloric  acid  heated 
neariy  to  boiling;,  when  the  ferric  oxide  and 
]>hosphate  pass  mto  solution,  leaving  insoluUe 
silica.  The  solution  is  evaporated  to  dryness, 
moistened  with  strong  hvarochloric  acicC,  and 
taken  up  with  water;  the  silica  is  collected, 
ignited,  and  weighed,  its  j^urity  beins  tested  by 
treatment  with  hydrofluoric  and  sulphuric  acida. 
The  jphosphoric  acid  in  the  filtrate  is  estimated 
by  either  of  the  following  methods. 

(a)  The  ferric  solution,  diluted  and  almost 
Dcutralised  with  ammonia,  is  reduced  with  sul- 
phurous add  or  sodium  sulphite.  Hydrochloric 
acid  is  added  and  the  excess  of  sulphur  dioxide 
expelled  by  boiling.  A  small  portion  of  the 
ferrous  iron  is  now  reoxidised  with  a  few  drops 
of  bromine  water.  Ammonia  is  added  care- 
fully till  a  brown  precipitate  is  formed  which 
becomes  green  on  stirring.  Acetic  acid  is  added 
till  the  precipitate  either  dissolves  or  becomes 
whiter,  and  the  solution  then  heated  to  boiling. 
The  precipitate,  which  contains  all  the  phos- 
phorus as  feme  phosphate  mixed  with  oasic 
ferric  aoetate,  is  dissolved  in  hydrochloric  acid, 
the  solution  evaporated  nearly  to  dryness,  excess 
of  citric  acid  adaed,  and  then  magnesia  mixture 
and  ammonia.  The  masnesium  ammonium 
phosphate  is  ledissolved  m  hydrochloric  acid 
and  reprecipitated  in  the  presence  of  citric  acid 
to  remove  a  small  amount  of  iron,  and  ignited 
and  weighed  as  "Mg^fi,. 

(h)  llie  filtrate  from  the  silica  is  evaporated 
to  dryness,  the  residue  dissolved  in  dilute  nitric 
acid,  ammonium  nitrate  added,  and  the  solution 
heating  to  boiling.  A  boiling  solution  of  am- 
monium molybdate  is  then  added  to  phosphate 
solution,  when  ammonium  phosphomolybdate  is 
precipitated  quantitatively.  This  precipitate  is 
redissolved  in  ammonia  to  which  ammonium 
nitrate  and  ammonium  molybdate  are  added, 
and  reprecipitated  by  adding  hot  nitric  acid  to 
the  boiling  solution.  The  compound  is  now 
pure,  and  is  collected,  washed  with  water  con- 
taining ammonium  nitrate  and  nitric  acid,  and 
either  dried  at  160*-180*  or  gently  i^ted.  In 
the  former  case  it  is  weighed  as  (NH4),P04, 
12MoO,  (containing  3*782  p.c.  P-O^)  or  in  the 
latter  as  P,Ob,24MoO|  (containmg  3*046  p.a 
£tOs)  {v.  Ber.  1878,11,1640;  Zeitsch.  anorg. 
1803,  32,  144 ;  Amer.  Ghem.  J.  34,  204 ; 
h,  1009,  34,  302 ;    Ghem.  Zeit.  21,  442). 


Separation  of  phosphoric  and  titanic  acids  {v. 
J.  Soc  CSiem.  Ind.  1805,  14,  443).  Estimation 
of  pho^horus  in  phosphor-bronze  (v.  J.  Amer. 
Ghem.  Soa  1807,  10,  306)  in  phosphor-tin 
(J.  Soo.  Ghem.  Ind.  1008,  27,  427). 

SiUcic  add  from  titanic  actd.  The  silica 
and  titanium  dioxide  are  weighed  together,  the 
mixture  fused  with  a  somewhat  laice  quantity 
of  potassium  hydrogen  sulphate,  ana  the  cooled 
mass  extracted  wiui  wat^.  Silica  is  left  un- 
dissolved, titanic  oxide  dissolves,  and  can  be 
raecipitated  from  the  filtrate  by  ebullition  {v. 
Titanium), 

Sulphides,  If  the  sulphides  are  decom- 
posable by  hydrochloric  acid,  the  hydrogen 
sulphide  is  absorbed  in  hydrochloric  acid  con- 
taining bromine  (v.  Determination  of  metals). 
Insoluble  sulphides  are  decomposed  by  gently 
heating  with  aqua  regia  or  with  hydrodiloric 
acid  and  bromine,  and  the  sulphuric  aoid 
estimated  in  the  solution.  The  latter  method 
gives  the  total  sulphur. 

Sulphur  in  com  and  coke.  The  finel v  pow- 
dered material  (1  gram)  is  mixed  intimately  with 
1  gram  of  calcined  magjnesia  and  0*5  gram  of 
sodium  carbonate,  and  ignited  to  dull  redness 
in  an  open  platinum  crucible  for  1  hour,  the 
mixture  bein^  stirred  every  five  minutes  with 
a  platinum  wire.  The  mixture  is  then  heated 
strongly  for  10  minutes  with  1  gram  of  am- 
monium nitrate.  The  residue  is  extracted  with 
water  and  the  sulphate  determined  in  the  usual 
way  (Eschka).  Ilie  sulphur  may  also  be  deter- 
mined by  heating  the  ooial  with  sodium  or  potas- 
sium carbonate  (4  parts)  alone^  and  extracting 
the  residue  with  hydrochloric  acid  and  a  few 
drops  of  bromine  (Nakamura).  {Compare  also 
Zeitech.  angew.Ghem«  1905, 18, 1560;  Ghem.  Zeit. 
1008,  32, 340 ;  J.  Kuas.  Ghem.  Soc.  1902, 34,  457.) 

Stdphur  in  pffrites.  The  pyrites  is  oxidised 
either  by  fusion  with  sodium  peroxide  and 
sodium  carbonate  or  by  oxidation  with  nitric 
acid  and  bromine.  These  processes  convert  the 
sulphur  to  sulphate,  which  is  estimated  in  the 
usual  winr  (v.  J.  pr.  Ghem.  1802,  [2]  45,  103 ; 
Zeitsch.  anorg.  Ghem.  6,  303 ;  2.c.  1806,  12, 
120 :  J.  Soo.  Ghem.  Ind.  1005,  24,  7 ;  Ghem. 
News,  1006,  03,  213). 

A  convenient  method  of  determining  sulphur 
in  pyrites  consists  in  oxidation  with  bromine 
in  carbon  tetrachloride  solution,  followed  by 
treatment  with  nitric  acid,  and  precipitation  of 
the  sulphuric  aoid  as  barium  sulphate  after 
removal  of  silica  and  reduction  of  ferric  salte 
(J.  Soc.  Ghem.  Ind.  1012,  010).    Bartsoh  (Ghem. 
Zeit.  1010,  43,  33)  finds  that  the  sulphur  in 
pyrites  yields  hydrogen  sulphide  when  treated 
with  hydrobromio  acid  in  contact  with  mercury 
and  bases  on  this  observation  a  rapid  method 
for  the  valuation  of  pyrites.    For  details  of  the 
process  and  the  apparatus  employed,  see  Analyst^ 
1010,  148. 

Sulphuric  acid  /rom  all  other  acids  except 
hudrofluosiUcic  by  precipitation  with  barium 
chloride  in  presence  of  hydrochloric  add. 

Sulphurtc  add  from  hydrofluosiUdo  acid. 
The  solution  is  mixed  with  excess  of  potassium 
chloride  and  an  equal  volume  of  strong  alcohol, 
filtered  through  a  weighed  filter,  and  the  precipi- 
tate of  potassium  silicofluoride  (K^iF«),  washed 
with  a  mixture  of  equal  volumes  of  alcohol  and 
water,  and  dried  at  100^.    The  sulphuric  acid  in 


ANALYSTS. 


265 


tbe  filtiate  is  estimated  in  the  usual  way  after 
evaporation  of  the  aloohoL 

Titamc  add  from  silicic  add  {v.  SUicic  add 
from  HUxnic  add). 

Boric  add.  The  borates  of  the  alkali  and 
alkaline  earth  metals,  when  heated  with  pure 
methyl  alcohol  (free  from  acetone)  and  acetic 
add,  evolve  all  the  boron  present  in  the  form  of 
methyl  borate  (b.p.  65^).  This  liquid,  when 
added  to  moist  lime,  is  completely  hydrolysed 
and  the  boric  acid  set  fiee  combines  with  the 
calcium  oxide  forming  calcium  borate.  The 
decomposition  is  effectM  in  a  small  retort  fitted 
with  a  tap  funnel  for  introducing  further  quan- 
tities of  methyl  alcolioL  The  retort  is  connected 
with  a  water  condenser  and  a  conical  flask 
containing  a  weighed  amount  of  quicklime.  This 
lime  is  carefully  slaked  before  the  distillation, 
and  the  methyl  borate  dropping  into  the  conical 
flask  is  decomposed  and  the  boric  acid  taken  up 
by  the  lime.  The  contents  of  the  receiver  are 
rinsed  into  a  platinum  dish,  and  the  methyl 
alcohol  evaporated  at  as  low  a  temperature  as 
possible.  The  residue  is  cautiously  ignited  to 
destroy  calcium  acetate,  and  the  increase  in 
weight  of  the  lime  represents  the  amount  of 
bone  anhydride  B,0,  ootained  from  the  borate. 
Tnst<wid  A  lime,  aqueous  ammonium  carbonate 
may  be  used  in  the  receiver,  and  the  liquid 
poured  on  to  slaked  lime  (from  a  known  we^ht 
of  quicklime)  contained  in  a  platinum  (ush 
(Zeitsch.  anaL  Ghem.  1887,  26,  18,  364). 

VOLUMXTBIO  MbtHODS. 

In  volnmetric  analysis  the  proportion  of  a 
■nbstance  is  ascertained,  not  by  separation  and 
weighing,  but  by  determining  the  exact  volume 
of  a  reagent  solution  of  known  concentration 
remiired  to  produce  some  particular  reac^on, 
saoh  as  neutralisation,  oxidation,  or  precipita- 
tion. The  termination  of  the  reaction  is  mdi- 
cated  by  some  end-reaction,  which  is  usually  a 
production,  destruction,  or  change  of  oolour, 
the  fonnation  of  a  permanent  precipitate  or 
the  cessation  of  the  formation  of  a  precipitate. 
In  determining  the  strength  of  caustic  soda,  for 
example,  it  is  coloured  yellow  with  methyl 
orange,  and  a  dilute  sobition  of  sulphuric  acid 
of  known  strength  is  added  gradually  until 
the  yellow  oolour  of  the  methyl  orange  just 
changes  to  red,  thus  indicating  the  point  of 
neutralisation.  The  volume  of  acid  required  is 
noted;  the  weight  of  sulphuric  acid  which  it 
contains,  and  hence  the  weight  of  soda  which 
it  will  neutralise,  is  known,  and  thus  the  pro- 
portion of  soda  in  the  substance  is  determined. 

In  order  that  a  reaction  may  serve  as  the 
basis  of  a  volumetric  process,  it  must  be  rapid, 
simple,  and  definite,  and  not  complicated  by 
seoondary  reactions.  It  should  remain  constant 
throng  considerable  variations  in  conditions, 
and  should  not,  for  example,  be  materially 
affected  by  the  degree  of  concentration  of  the 
solution.  A  final  reaction  should  be  rapid,  per- 
fectly decisive,  and  should  only  require  a  slight 
excess  of  the  reagent  for  its  production.  In 
many  cases  a  thini  substance  is  employed  to 
mdwate  the  oom|ilBtion  of  the  reaction,  and  is 
termed  an  indicator.  It  is  an  irUernal  indicator 
if  it  is  added  to  the  bulk  of  the  liquid,  an  external 
indicator  if  drops  of  the  liquid  are  removed  and 
brought  in  contact  with  it. 


1  The  execution  of  volumetric  processes  in- 
volves the  possession  of  accurately  graduated 
instruments  of  three  kinds,  viz.  flasks,  pipettes, 
and  burettes.  The  flasks  should  be  fitted  with 
well-ground  stoppers,  and  should  have  some- 
what long  necks,  the  graduation  being  not  hisher 
than  the  middle  of  the  neck,  in  order  that  there 
may  be  sufficient  empty  space  for  efficient  agita- 
tion. FUsks  holdinff  respectively  1000  o.c.,  600 
CO.,  260  C.C.,  and  100  c.c.,  are  used.  Each  flask 
should  have  two  graduation  marks,  vis.  the 
containing  mark,  indicating  the  point  to  which 
the  flask  must  bo  filled  in  order  that  it  may 
then  contain  the  particular  volume  of  liquid,  and 
the  delivery  marls  or  point  to  which  the  flask 
must  be  fiUed  in  order  that  it  may  deliver  the 
^ven  volume  of  liquid  when  emptied  by  drain- 
,ing.  A  pipette  is  usually  a  cylindrical  bulb 
terminating  at  each  end  m  a  tube,  the  lower 
of  which  is  drawn  out  to  a  jet,  whilst  the  end 
^of  the  upper  tube  is  slightly  jx>ntraoted  so  that 
it  may  be  readily  dosM  by*the  forefinger  and 
the  flow  of  liquid  regulated  or  stopped  altogether. 
Usually  a  pipette  mis  only  a  delivery  mane,  but 
occasionally  they  are  graduated  throughout  their 
whole  length,  and  then  take  the  form  of  a  some- 
what wide  tube  contracted  to  a  jet  at  the  bottom 
and  terminating  in  a  narrower  tube  at  the  top. 
Pipettes  of  100  cc,  60  cc,  26  cc,  10  cc,  and  6 
CO.  capacity  are  most  generally  useful.  A  burette 
is  a  long  tube  of  uniform  bore,  12  to  16  mm.  in 
diameter,  graduated  in  cubic  centimetres  and 
tenths  or  fliths.  A  convenient  capacity  is  60  cc 
It  is  open  at  the  top  and  contracted  at  the 
lower  end,  to  which  a  glass  jot  is  attached  by 
means  of  a  piece  of  narrow  indiarubber  tubing. 
This  tubing  is  nipped  by  a  sprins  pinohcock, 
which  is  opened  by  the  pressure  of  tne  fingefs, 
the  flow  01  liquid  beine  thus 
regulated.  A  better  plan  is 
to  insert  in  the  indiarubber 
tubing  a  short  piece  of  glass 
rod  the  diameter  of  which  is 
just  sufficient  to  prevent  the 
flow  of  liquid  when  the  tub- 
ing remains  oiroular.  If,  however,  the  tubing 
is  squeezed  out  laterally  by  the  pressure  of 
the  thumb  and  fore  finger  (Fig.  9),  a  channel 
is  made  through  which  the  fiquid  can  pass, 
and  by  increasing  or  reducing  the  pressure,  the 
flow  of  liquid  can  be  regu&ted  to.  a  nicety. 
Certain  reagents  act  upon  indiarubber,  and  for 
these  a  burette  with  a  glass  stopcock  should  be 
used.  This  form  is,  in  fact,  the  most  convenient 
for  all  purposed.  The  stopcock  may  be  pre- 
vented from  sticking  by  a  little  vaseline  or 
paraffin,  and  from  slipping  out  by  a  small  india- 
rubber  ring  passed  over  the  tap  and  round  the 
burette  tube.  Sometimes  the  tube  carrying  the 
stopcock  is  not  in  the  same  line  with  the  burette, 
but  is  bent  twice  at  right  angles,  so  that  the 
burette  jet,  although  stifl  vertiiuJ,  is  one  or  two 
inches  in  advance  of  the  burette  itself.  This 
form  is  useful  when  titrating  hot  liquids,  since 
the  risk  of  heating  the  burette  and  its  contents 
is  reduced.  An  utemative  method  is  to  have 
the  top  of  an  ordinary  burette  funnel-shaped, 
which  admits  of  the  burette  being  slung  m  a 
stand  by  the  funnel  without  other  support,  so 
that  it  can  be  tilted  from  the  vertical  when 
titrating  hot  solutions. 

When  a  burette  is  in  use,  it  is  important  that 


<» 


FiQ,  9. 


266 


ANALYSTS. 


it  should  be  supported  in  a  vertical  position. 
This  can  be  done  oy  means  of  a  clamp  attached 
to  a  stand  similar  to  a  retort  stand.  A  useful 
and  easily  oonstnicted  burette  stand  is  described 
m  J.  Amer.  CSiem.  Soo.  1906,  27,  1442. 

When  several  different  solutions  are  being  used 
continually,  it  is  convenient  to  have  the  series 
of  burettes  attached  to  a  revolving  stand,  so 
that  each  mav  be  brought  round  to  the  front 
when  required.  Short  test-tubes  uiverted  over 
the  tops  of  burettes  serve  to  keep  oat  dust. 

Standard  ioltUuma  should  be  kept  in  well- 
stoppered  bottles  in  a  oool  place  protected  from 
bright  liffht.    When  many  determinations  of 
the  samekind  have  to  be  made,  it  is  convenient 
to  keep  the  reservoir  of  standard  solution  at- 
tached to  the  burette  to  facilitate  the  filling  of 
the  latter.     A  glass   T-piece  is  introduced  be- 
tween the  graduated  part  of  the  burette  and  the 
stopcock  or  pinchcock,  and  is  attached  by  means 
of  an  indiarubber  tube  to  a  tubulus  at  the  bottom 
of  the  bottle  which  contains  the  standard  solution 
and  stdnds  on  a  shelf  above  the  burette.    If  this 
bottle  haa  no  tubulus,  a  glass  tube  bent  twice  at 
right  angles,  with  .one  Umb  reaching  to  the  bottom 
of  the  bottle  and  the  other  connected  with  the 
burette,  is  fitted  into  the  neck  of  the  bottle  by 
means  of  a  cork,  and  is  kept  always  full,  so  that 
it  acts  as  a  siphon.    There  must,  of  course,  be 
an  entrance  for  air  as  the  liquid  flows  from  the 
bottle.  The  flow  of  liquid  into  the  burette  is  reffu- 
lated  by  a  pinchcock  on  the  indiarubber  tuoe. 
If  the  standard  solution  acts  upon  indiarubber, 
pJl  these  connections  must  be  constructed  of 
elasB  tubing.    Burettes  may  now  be  obtained 
fitted  with  Greiner  and  Friedrich's  three-way  taps 
(compare  Fig.  12) ;  Uieee  are  readily  connected  to 
reservoirs  and  filled  from  the  bottom.     Filling 
the  burette  from  the  bottom  avoids  the  forma- 
tion of  air-bubbles,  but  it  oan  also   be  filled 
from  the  top  if  the  tube  from  the  stock  bottle 
is  bent  slkhtly  so  that  the  liquid  flows  down 
the  side  of  the  burette.    A  convenient  form  of 
apparatus  for  Uiis  method,  which  is  the  only  one 
available  with  an  ordinary  tap  burette  without 
a  side-tube  attachment,  is  described  in  Chem. 
News,  1906,  93,  71.     When  the  standard  solu- 
tion  alters  it  exposed  to  air,  the  surface  of  the 
liquid  mav  be  covered  with  a  layer  of  rectified 
paraffin  of  moderately  high  boiling-point,  or  the 
neck  of  the  bottle  may  ro  provided  with  a  cork 
oanying  a  tube  containing  caustic  potash,  or 
alkaline  pyrogallate,  through  which  all  air  enter- 
ing  the  Dottle  haa  to  pass.    A  still  better  plan 
is  to  fill  the  upper  part  of  the  stock  bottle 
with  carbon  dioxide,  or,  if  the  nature  of  the 
solution  permits,  with  coal  gas,  and  connect  it 
by  means  of  a  cork  and  tube  with  a  self-acting 
carbon  dioxide  apparatus  or  the  ordinary  gas 
supply.    When  solution  is  withdrawn,  carTOU 
dioxide  or  coal  gas  enters.    The  burette  should 
be  kept  permanently  attached  to  the  reservoir  as 
just  described,  and  the  top  end  of  the  burette  also 
put  into  communication  with  the  inert  gas  supply. 

OradtuUian  of  the  inntrumtnU. — Accurate 
calibration  of  the  measuring  vessels  is  of  course 
necessary  if  correct  results  are  to  be  obtained, 
and  it  is  never  advisable  to  trust  the  makers' 
graduations.  All  the  instruments  should  be 
checked  before  being  taken  into  use.  Although 
it  is  sufficient  for  most  purposes  if  the  relative 
volumes  of  the  vessels  are  correct,  they  should 


nevertheless  be  graduated  in  true  cubic  centi- 
metres. With  gaa-volumetrlc  apparatus  this 
procedure  is  essentiaL  If  the  oalioration  is  per- 
formed at  a  temperature  of  18^-20^,  variations 
from  the  true  volume  resulting  from  the  ex- 
pansion of  the  glass  are  so  small  for  the  intervals 
of  temperature  through  which  the  laboratory  is 
likely  to  vary,  that  they  may  be  neglected. 

The  vessels  are  checked  by  ascertaining  the 
weight  of  distilled  water  at  a  Imown  temperature 
which  they  will  contain  or  deliver  as  the  caee 
may  be.    A  larm  beaker  of  distilled  water  is 

E laced  in  the  btuance  room,  and  left  for  some 
ours  till  its  temperature  has  become  constant. 
The  vessels  to  be  calibrated  are  thoroughly 
cleansed  by  miccesdve  treatments  with  concen- 
trated caustic  potash,  distilled  water,  and  a  warm 
solution  of  chromic  acid  in  concentrated  sul- 
phuric acid,  and  then  rinsed  vrell  with  distilled 
water.  The  flasks  are  then  dried.  A  narrow 
strip  of  paper  is  attached  vertically  to  the  neck 
of  the  litre  flask  near  the  mark,  the  flask  placed 
on  one  pan  dt  a  large  balance  capable  of  n- 
sponding  to  0*06  gram,  and  counterpoised. 
Weights  corresponding  with  the.  weight  of  water 
whi^  at  the  temperature  of  the  supply  in  use 
will  occupy  1000  cc,  are  then  placed  m  the  pajn  ; 
the  flask  is  filled  nearly  to  the  mark  with  water, 
and  water  is  gradually  added  until  flask  and 
weights  are  in  equiliorium.  Any  water  ad- 
hering to  the  inside  of  the  neck  of  the  flask 
above  the  mark  must  be  removed  by  means  of 
filter  paper.  If  the  mark  on  the  neck  of  the 
flask  is  thus  found  to  be  in  error,  a  pencil  mark 
is  made  on  the  strip  of  paper  at  the  point  oorre- 
BpondJQg  with  the  lower  edge  of  the  menisous, 
the  glass  above  and  below  is  evenly  ooated  with 
a  thin  film  of  ^vax,  and  a  horiaM>ntal  ring  is 
scratched  through  by  means  of  a  needle  pre- 
cisely on  a  level  with  the  pencil  mark.  The 
ring  is  covered  with  a  small  piece  of  filter  paper, 
which  is  moistened  with  hydrofiuorio  adcl,  cars 
being  taken  to  remove  air- bubbles.  After  a 
few  minutes  the  acid  is  washed  off  and  the  wax 
removed,  when  a  new  mark  will  be  found  ctcEod 
into  the  glass. 

In  calibrating  volumes  by  determining 
weights  of  water,  it  is  neceesazy  to  reduce  tbe 
weight  to  vacuum  standard,  and  then  divide 
the  result  by  the  density  of  the  water  in  order 
to  obtain  accurately  the  volume  in  true  cubic 
centimetres.  This  calculation  oan  be  avoided 
by  making  use  of  the  following  table  : — 


X 

0** 
119 

1« 
113 

2« 
1-09 

3* 

1-07 

4« 
1-06 

6* 

1-07 

X 

6« 
109 

7** 
113 

8« 
1-18 

9» 
1*26 

10» 
1-33 

1-43 

X 

12* 
1-63 

13* 
1-65 

14* 
1-78 

15« 
1-93 

16' 
2-09 

17* 
225 

X 

18* 
2-43 

19* 
2-62 

20* 
2-82 

21* 
3-03 

22*» 
3-26 

23* 
349 

X 

24* 
3-73 

25« 
3-98 

26* 
4-24 

27* 
4-52 

28* 
4-80 

29» 
6-08 

30« 
6-38 

r  is  the  quantity  to  be  subtracted  from  1000 


to  obt^  tbr  appMent  wcigbt  (in  ur,  irbiB 
bnss  weights  ue  empJoTcd)  of  1000  <Le.  of  nter 
ftt  Uie  teinperatnra  I.  Far  ezknple,  «t  IS*  Um 
•pjMrent  weight  of  1000  o.c.  ii  1000  -  S-«3  = 
097 -67  grami. 

Th«  lib*  flask  hkTing  been  gndotited  t« 
contun,  it  shoold  now  be  gndnatod  to  deliTer. 
The  Ml  Buk  ii  Mrefullj  empUed  Hid  allowed 
to  di«in  tot  a  definite  time — n;  thirty  seoonda 
— emiD  «ODDterpot«ed'  with  tiie  water  adhering 
U>  Um  inaide,  and  a«ain  filled  with  a  further 
1000  «.e.  of  water  m  Ota  manner  {wvTiously 
described,  lite  other  flasks  uc  gradaated  in 
c  wsji  aDbtracting  only   \x  b 


a  pipette  will 
ddjrar  depends  to  K>me  extent  on  the  mamier 
in  which  it  ia  emptied.  A  small  qoantity  of 
liqnid  always  remamt  in  the  jet,  and  this  should 
not  be  blown  oat.  The  best  plan  La  to  allow 
the  pipette  to  empty  itself  whilst  held  veiticaily, 
and  then  to  let  it  drain  for  twenty  woonds  with 
the  point  of  the  pipette  jnst  touching  the  side 
of  the  receiving  veeael ;  bat  the  method  of 
emptying  employed  in  the  calibntion  mast  be 
adhered  to  in  its  mbeeqnent  use. 

To  teat  the  aomuBoy  with  which  a  pipette 
has  b««ii  Eraduated,  it  is  filled  to  the  mark 
with  distilled  vat«i  at  an  observed  tempera- 
ture, tlie  contents  delivered  into  a  liRht,  tared, 
stoppered  flask,  and  aconrately  weighed.  The 
operation  is  repeated  aeveral  times,  and  from 
we  mean  reealt  the  true  volome  is  calcnlated 
by  oaiiig  the  table  previously  given  ;  (or  it  is 
ideal  that  1 —  r^^denotca  the  apparent  weight  of 
lo.o.of  water  at  (*,  or  l+~g  equals  the  volume 
at  1*  occupied  by  1  gram  of  wat«r  weighed  in 
air  with  braas  weights.  If  the  error  in  giadna- 
tion  is  greater  tiian  can  be  allowed,  another 
mark  must  be  made ;  its  position  may  be  found 
bv  repeated  trials,  a  atrip  of  paper  being  pasted 
aUNig  the  item,  and  the  Tolames  corresponding 
to  various  pencil  marks  being  found  as  above. 
The  new  mark  is  then  etched  in  with  hydro- 
fluoric  acid. 

A  convenieut  method  for  directly  oaU  bra  ting 
fnpettes   is  described  by  Thorpe  (Quantitative 
Analysis).    The  pipette  is  bus- 
pended   from   ona  arm  of   a  | 

Mance  by  means  of  a  oUp,  . 
BO  aa  to  iiang  perpendicularly  > 
and  pasa  through  a  hole  hi  the 
bottom  al  the  balance  case  or 
of  a  specially  oonstrncted  table. 
A  Euitable  clip  (Fig.  10)  ooa- 
sists  of  a  stout  braaa  wirelrome 
carrying  two  chjpa 
brass  ctoBB 

'pipett. 
is  passed   through  the  lovei 
clip  and  connected  by  caout- 
chouc tubing  with  a  glaaa  stop- 
cock fixed  in  the  npper  clip. 
The  other  end  of  the  stopcock         Fia.  10.  • 
is  provided   with  a  piece    of 
caoutchouc  tubing,  to  which  a  piece  of  thermo- 
meter tube  or   a   piece   of   wider    glass   tub* 
can  be  attached-    The  wider  glasa  tube,  which 
serrei  a*  a  mouthpiece,   is   first   attached   to 
the  Btopeook,  and    the    pipette   is  hUod   with 


y  sliding  CO 


YSIS.  187 

water  to  a  short  distance  above  the  mark,  and 
then   emptied   by  the  method  to   be  adored 
in    its    subsequent   use.     It    is    then   oounter- 
poised  on  the  balance  with  the  adhering  water 
maide,  the  wide   tube  being   teplaoed   by   tba 
thermometer  tube,  and   the  requisite   weights 
plaoed  cm  the  other  pan.    The  pipette  is  again 
filled  to  a  short  distance  above  the  mark  ;   the 
thermometer  tube,  which  is  drawn  out  at  one 
end,   ia  attached  again,   and   the  stoucook   is 
opened.      Water  drops  very  slowly  bom  the 
end  of  the  pipette,  and  it 
can  be  arrested  the  moment 
the   balance    is    in    equili- 
brium.    The  level  of  the 
water  is  marked  on  a  |Heoe 
of   paper  gummed   to   the 
pipette,   and   a   new    ring 
etched     with     bydroflu<»io 

The  burette  is  most 
simply  calibrated  by  the 
meuiod  due  to  Ostwald  with 
the  help  of  a  small  pipette 
of   about    2   a.c   oapncity,  \J 

attached  to  the  burette  as 
indicated   in  Fig.   U.     The 
burette  and  pipette  are  filled 
with  water  to  the  lero  mark 
and    the    mark   a    respec- 
tively, taking  care  to  leave 
DO  air  bubbles  in  the  tubes.  , 
The  clip  I  (or  the  tap  of  the 
burettejisopenedand  water 
allowed   to   run    from   the 
burett«  into  the  pipette  till 
the  level  b  is  reached.    The 
burette  reading  is  then  no- 
ted, and  thepipette emptied 
to  inark  a.  Tjieee  operations         f,o.  u, 
of  filling  the  pipette,  taJdng 
B  burette  readins,andthen  emptying  the  pipette, 
are  repeated  to  the  full  extent  of  Uie  burette  read- 
ings.    Suppose,  for  example,  that  after  twenty- 
four  fillings  the  burette  reading  is  49-49  o.c    The 
burette  is  now  refilled,  and  exacdy  this  amount 
of  distilled  wat«r  is  run  out  into  a  tared  Qask  and 
weighed,  naing  all  the  precautions  that  would 
be  observed  in  an  actual  titration.     From  the 
table  already  given  the  true   volume  of  this 
water  is  calculated.   Suppose  this  to  be  40'44  CO. 
Then  the  volume  of  the  calibrating  pipette  must 
be   —^  =  2-060  0.C     The  difFerencea  between 
the  successive   burette  readings  and   the  suo- 
rpxsive  nnmbers  2'06,  4'12,  B-)S  .  .  .  give  at  once 
the  burette  errors  at  these  intervals,  due  rrgard 
being  paid  to  the  sign  of  the  difCerence.     In  the 
ciample  quoted,   the  correction  to   be  applied 
for  60  CO.  ia  obviously  —0-06  c.c.  {are  J.  Amer. 
Chem.  Soc.  1900,  22,  149 ;   and  for  a  modifioa- 
Uonofabove,J.Ainer.Cbem.8oc.  1901,23,484). 

A  better  design  for  a  calibrating  pipette  is 
shown  in  Fig.  12,  which  also  illustrates  the 
Greiner  and  Friadrieh  three-way  tap  (Morse 
Bud  Blalock,  Amer.  Cbem.  J.  18M,  16,  4TS). 

The  gas  burettes  described  under  Oat 
analgti*  may  be  calibrated  in  much  the  same 
way  aa  an  ordioaiy  burette,  by  filling  with 
water  or  mercuiy,  ikawing  off  ahquot  portions 
and  weighing  them,  the  temperature  of  the  liquid 
being  noted  and  the  appropnate  eorrecUvn  made 


268 


ANALYSIS. 


for  ezDMLrion.    Any  error  thus  detected  must 
be  usea  as  a  correction  in  sabseqvent  readings. 

Siandard  doluiions,  —  These 
form  the  baaiB  of  all  Yolumetrio 
work,  and  great  care  should  be 
exerdsed  in  their  preparation. 
When  a  solution  is  used  only 
for  the  estimation  of  one 
substance,  it  may  be  convenient 
to  adjust  its  strength  so  that 
each  C.C.  is  equivalent  to  some 
simple  and  demiite  quantity  of 
the  substance,  say  0*01  gram; 
but  for  general  purposes  the 
so-called  normal  sottUions  should 
be  employed.  A  normal  solu- 
tion contains  in  1000  aa  the 
equivalent  in  grams  of  the  active 
substance.  A  solution  of  one- 
tenth  this  streugth  is  termed  a 
decinormal  solution,  and  one 
of  a  hundredth  a  cenUnormal 
solution.  Thus  a  normal  solu- 
tion of  sulphuric  acid  contains 
49*04  grams  of  real  add  per 
litre,  a  decinormal  solution  of 
iodine  contains  12*69  grams  of 
iodine  per  litre,  and  each  litre 
of  a  decinormal  solution  of 
potassium  permanganate  con- 
tains  0*8  grams  of  active  oxygen. 
Stan<uutl  solutions  are  usu- 
ally made  up  approximately 
normal  or  dednormal  as  the  case  may  be, 
and  afterwards  accurately  standardised  by 
titration  against  a  weighed  amount  of  some 
pure  compound.  If  the  solution  has  been  pur- 
posely made  rather  too  concentrated,  it  may 
then  be  suitably  diluted  until  exactly  normiu 
or  decinormal.  Since  accurate  adjustment  by 
dilution  is  difScult  to  effect,  and  in  a  certain  cases 
inadvisable,  it  is  usuallv  better  to  avoid  the 
process  and  determine  a  fador  by  which  readings 
must  be  multiplied  in  order  to  convert  them  into 
equivalent  readings  of  a  normal  or  decinormid 
solution.  For  example,  if  1  co.  of  potassium 
permanganate  solution  is  found  to  be  capable 
of  oxidising  0*005630  grams  of  iron,  then  since 
the  corresponding  figure  for  a  decinormal  solu- 
tion is  0*005586,  the  permanganate  is  ||^*  or 

1*008  times  decinormal,  and  when  using  it  to< 
estimate  a  substance  of  equivalent  x,  each  cs. 

X  1<008 


Fio.  12. 


10000 


of   permanganate   will  oxidise 

grams  of  substance.  When  only  one  or  two 
litres  of  a  standard  solution  are  required,  and 
the  pure  reagent  is  at  hand,  the  exact  quantity 
may  be  weigned  out  and  diluted  to  tiie  appro- 
priate volume ;  t,g,  solutions  of  silver  nitrate  and 
potassium  diohromate  may  be  thus  prepared. 

Measurements. — In  measurinc  out  solutions, 
&0.,  the  vessels  must  be  perfectly  dry,  which  is 
inconvenient,  or  must  be  well  drained  and  then 
rinsed  out  with  a  small  quantity  of  the  solution 
to  be  measured,  which  is  allowed  to  nw  away. 

To  read  correctly  the  level  of  tiie  liquid  in  a 
burette  or  pipette  requires  certain  precautions. 
In  the  first  place,  the  instrument  must  be  held  in 
a  vertical  position.  Ordinary  liquids  form  a 
concave  sumce,  or  meniscus,  and  the  reading 
should  always  be  taken  from  the  lowest  point  of 


this  curve,  except  in  the  case  of  very  dark- 
coloured  solutions,  when  the  upper  line  of  the 
surface  must  be  taken.  The  menisous  must  be 
properly  illuminated,  and  on  a  level  with  the 
eye,  in  order  to  avoid  parallax.  Hie  best 
method  of  avoiding  this  error  is  by  the  use  ol 
a  burette  having  tne  graduation  marks  oarried 
half-way  round  the  tube.  In  default  of  snoh 
a  burette,  use  may  be  made  aooording  to  Mohr 
of  a  piece  of  card  one-half  of  which  is  black 
and  the  other  half  white.  This  is  attached  to 
the  burette  by  an  indiarubber  ring,  and  is  ad- 
justed so  that  the  horizontal  edse  of  the  bUok 
half,  which  is  lowest^  is  2  to  3  mm.,  Imt  nol 
more,  below  the  meniscus.  The  lower  edge  of 
the  curve  then  appears  black  against  the  white 
background.  If  the  card  is  too  low,  the  readiiw 
will  be  slijjhtly  too  hiffh.  The  little  clamp  and 
screen  ddBipiid  by  Qdokel  are  based  on  the 
same  principle.  Some  burettes  are  provided  at 
the  back  with  a  dark  vertical  line  on  a  milk 
glass  background.  When  the  eye  is  on  a  level 
with  the  Mttom  of  the  meniscus,  the  dark  liiM 
appears  to  be  drawn  out  to  two  fine  points 
wbich  just  touch  one  another.  By  means  of 
these  aevioes  accurate  readings  can  easily  be 
taken  even  without  using  a  burette  float. 

In  addition  to  the  eixorB  incident  to  all 
analytical  processes,  another  error  arises  in 
volumetric  analysis,  owing  to  variations  in  the 
concentrations  of  the  solutions  due  to  changes 
of  temperature.  In  the  ease  of  ^/lO-solntions 
this  a^ts  the  results  to  the  extent  of  O*lp.o. 
for  each  6*  variation  in  temperature.  With 
concentrated  solutions,  especially  those  of  the 
acids  and  alkalis,  the  error  is  greater.  The 
coefficients  of  expansion  of  certain  standard 
solutions  have  beoi  determined  by  A.  Sdinlse 
(Zeitsoh.  anaL  Chem.  21,  167). 

Errors  due  to  changes  of  temperature  may  be 
eliminated  by  weighii^  the  solutions  instead  of 
measuring  them.  The  liquid  is  contained  in  a 
light  glass  bottle,  with  a  urns  jet-like  neck,  and 
a  tubulus  at  the  shoulder  wnich  can  be  closed 
by  the  finger,  and  the  flow  of  liquul  thus  refpi" 
lated.  T&  bottle  is  weighed,  the  lolutioo 
poured  gradually  from  it  until  the  reaction  is 
complete,  and  the  bottle  again  weighed.  The 
difference  between  the  two  weighings  gives  the 
quantity  of  solution  used.  Convenient  weight 
burettes  are  described  in  CSiem.  News,  1877, 
35,  08 ;  J.  Amer.  Chem.  Soc.  1908,  30,  81. 

Volumetric  methods  may  be  broadlv  dassi* 
fled  as  L  Methods  of  Saturation ;  IL  Methods 
of  Oxidation  and  Reduction ;  IIL  Methods  of 
Precipitation ;  and  examples  of  the  two  latter 
types  of  processes  are  indicated  bdow.  (For 
methods  of  saturation,  «.  Acidiicbtbt  ahd 
At.kat.tmktry.) 

In  the  following  section  the  methods  for 
preparing  and  standardising  the  more  com- 
monly employed  solutions  are  first  described, 
followed  by  details  of  the  various  volumetric 
estimations  for  which  these  solutions  may  be 
conveniently  employed,  alphabetically  arranged 
under  the  names  of  the  dements  that  are 
determined. 

PSEPABATION  09  StANDABD  SOLUTIOVS. 

Potassium  permanganate. 
Employed  as  an  oxidising  agent,  usually  in 


ANALYSIS. 


sm 


dilate  solphnric  add  solation,  when  the  per- 
manganate decomposes  according  to  the  equa- 
tion: 

2KMn04+8H^04 

c=K,S04+2MnS04+3H,0+50. 

The  oxidation  of  ferrous  sulphate,  for  ex- 
ample, is  represented  in  the  following  manner : — 

2KMnO«+  10FeSO4-f8HJ3O4 

=  K,S04-|-2MnS04+6Fog(S04)a-f8H,0 

and  of  oxalic  acid  thus : 

2KMn04+5H,C,04+3H,S04 

«  KjSO4+2MnSO4+8H,O4-10CO,. 
In  order  to  facilitate  calculation,  these  oxida- 
tions  are  conveniently  expressed  as  a  trans- 
ference of  oxygen  from  one  oxide  to  another,  t.g. : 

10FeO-}-MnaOf  »  5Fes04+2MnO. 

The  utilitT  of  permanganate  solution  de- 
pends upon  the  facts  that  such  oxidation  pro- 
cesses are  usuaUy  quite  easy  to  effect,  the  end- 
point  being  readily  indicated  by  the  solution 
acquiring  a  faint  permanent  pink  tinge,  due  to 
the  presence  of  a  alight  excess  of  permanganate, 
which  thus  acts  as  its  own  indicator.  Oxida- 
tion usually  proceeds  rapidly  at  the  ordinary 
temperature,  out  solutions  of  oxalic  acid  must 
be  heated  to  60''-80^.  It  is  most  essential  that 
a  considerable  excess  of  sulphuric  acid  should 
be  present  (about  6  cc.  of  concentrated  acid  per 
100  0.0.  of  solution),  since  otherwise  the  solution 
becomes  turbid  owing  to  the  separation  <rf 
manganese  dioxide,  and  the  determination  is 
spoilt.  The  presence  of  hydrochloric  acid  in 
the  solution  snould  be  avoided,  if  possible,  since 
it  reaots  with  the  permanganate  under  certain 
dzoomstanoes,  particularly  in  the  presence  of 
iron  salts,  llie  error  that  thus  arises  can  be 
reduced  to  a  negligible  amount  bv  adding 
manganese  sulphate  to  the  solution,  and  titrating 
very  slowly.  The  addition  of  colloidal  silioio 
acio,  added  in  the  form  of  a  solution  of  sodium 
silicate,  containing  about  0*1  gram  SiO.  per 
1  CO.,  entirely  prevents  the  oxidation  of  the 
hydrochloric  add  in  presence  of  manganous 
sulphate. 

PrvpanUion  and  titration  of  the  solution, — ^A 
dednormal  solution  containing  3*16  grams  of 
the  salt  per  litre  of  solution  is  most  conyenient 
for  general  use  ;  it  is  most  readily  prepared  by 
giindinfl  the  solid  repeatedly  with  small  amounts 
of  distiUed  water  in  a  mortar  and  decanting  the 
solution  into  the  stock  botUe.  After  a  day  or 
two,  the  solution  is  filtered  through  asbestos, 
and  standardised.  H  kept  away  from  direct 
sunlight,  reducing  gases  and  dust,  it  retains  its 
titre  for  a  long  time;  its  spontaneous  decom- 
position is  larffdy  augmented  by  the  presence 
of  aolid  dioxide,  which  explains  the  necessity 
for  the  filtration  through  asbestos  (Amer.  Chem. 
J.  1896, 18,  401). 

The  solution  Is  best  standardised  against 
eleotrolytio  iron,  anhydrous  sodium  oxalate,  or 
by  the  iodimetric  method  of  Volhard,  using  a 
thiosulphate  solution  which  has  been  recently 
titratea  against  pure  iodine.  (For  the  latter 
method,  m«  Thioniiphate  solution^  and  for  the 
first,  which  requires  a  somewhat  complicated 
apparatus,  consult  Treadwell-Hall,  voL  2,  81.) 

TUfxUioH  bff  9odium  oxaiate. — ^This  method 
was  proposed  by  Sorensen,  and  its  accuracy 
has   oeen  fully  estaUished  by  various  other 


chemists  (Zeitsoh.  angew.  Chem.  1902,  15, 
1244 ;  1904,  17»  230  i^  269 ;  1905,  18,  1520). 
The  pure  oxalate,  prepared  by  Eahlbaum  accord- 
ing to  Sdrensen's  diieotions,  should  be  dried  at 
1(X)^  for  a  few  hours  before  use. 

Three  or  four  portions  of  the  oxalate,  each 
weighing  about  0-25-0'30  grams,  are  dissolved 
in  an  excess  of  dilute  sulphuric  acid ;  the  solu- 
tions are  warmed  to  60^-80*,  and  titrated  with 
the  permanffanAte  solution  until  a  faint,  per- 
manent pink  colouration  is  obtained.  From 
the  relation  2Na.C,04  >■  0„  the  value  of  the 
permanganate  solution  is  calculated  for  each 
titration,  and  the  mean  of  the  concordant 
results  adopted  as  the  true  value  (e/  McBride, 
J.  Amer.  Chem.  Soc.  1912,  34,  393). 

Many  other  methods  for  stanoardising  per- 
manganate have  been  proposed,  e.0.  titration 
against  orystalline  oxauo  acid  HjC|04,2H|0, 
ammonium  oxalate  (NH4)|Cs04,UJD,  ferrous 
sulphate  FeS04,7HtO,  Mohr's  salt  FeS04. 
(NH4)2S04,6H2(),  &C.,  which  although  at  times 
convenient,  are  less  accurate  than  the  methods 
given.  Standardisation  against  iron  wire  is  not 
to  be  recommended,  since  the  small  quantities 
of  oxidisable  impurities  present  consume  more 
permanf^anate  than  would  be  required  by  their 
own  weight  of  iron,  and  the  error  is  augmented 
by  making  allowance  for  the  actual  iron  content 
of  the  wire  (Zeitsch.  anaL  Chem.  1903, 42,  859 ; 
Zeitsch.  angew.  Chem.  1901,  14,  1233;  also 
Treadwell-Hall,  <.c.). 

It  is  usual  to  express  the  concentration  of  a 
permanganate  solution  in  terms  of  the  amount 
of  iron  it  can  oxidise;  thus  1  0.0.  of  N/IO- 
KMn04  =  0-005585  gram  Fe. 

Potassium  diehromate. 

A  solution  of  this  reagent  may  replace 
permanganate  in  the  titration  of  ferrous  saks, 
with  the  advantace  that  it  can  be  used  in  the 
presence  of  either  nydrochloric  or  sulphuric  acid. 
An  excess  of  free  acid  Is  essential,  the  oxidation 
of  ferrous  chloride,  for  example,  proceeding 
according  to  the  equation  t 

K,(3r,0^+6Fea,+14Ha 

«  2Ka+2Cra,-i-6Fea,+7H,0 

which  is  essentially : 

2(M),-i-6FeO  =»  Cr,0,-f  3Fe,0,, 

A  deoinormal  solution  obtained  by  dissolving 

— ^^— ^  —  4-903  grains  of  the  pure  dry  re- 
crystallised  salt  in  distilled  water  and  diluting 
the  solution  to  1  litre,  requires  no  further 
standardisation.  A  stock  solution  of  approxi- 
mate strength  may  be  standardised  against 
several  weighed  amounts  (1-0-1*4  grams)  of 
pure  ferrous  ammonium  sulphate  by  a  similar 
procedure  to  that  described  under  the  standardi- 
sation of  permanganate  by  sodium  oxalate.  The 
titrations,  however,  are  made  in  cold  solution, 
and  the  dilute  sulphuric  acid  used  should  be 
gently  boiled  for  naif  an  hour  to  expel  dis- 
solved air,  and  cooled  rapidly  just  before  use. 
Since  the  green  colour  of  the  chromic  salt  pre- 
vents the  excess  of  diehromate  from  being  seen, 
an  external  indicator  is  necessary.  Drops  of  a 
dilute  solution  of  potassium  ferricyaniue,  free 
from  ferrocyanide,  are  placed  on  a  white  plate, 
and  from  time  to  time  the  end  of  a  glass  rod. 


270 


ANALYSIS. 


previously  dipped  in  the  titrating  fiask,  is 
brought  into  contact  with  a  drop  of  the  ferrl- 
cyanide.  As  Ions  as  any  ferrous  salt  remains  a 
blue  precipitate  u  produced;  the  approach  of 
the  end  is  indicated  by  the  decrease  in  intensity 
-of  the  blue  colouration,  and  when  very  near 
the  end  about  thirty  seconds  should  be  allowed 
for  the  colour  to  develop.  The  end-point  is 
reached  when  the  blue  colour  ceases  to  appear. 
The  ferricyanide  solution  should  be  prepared 
only  when  required  by  dissolving  in  water  a 
crystal  of  the  salt  which  has  been  rinsed  to  remove 
superficial  ferrocyanide :  the  yellow  colour  of 
the  drops  on  the  white  plate  should  be  barelv 
visible  ;  if  the  ferricyanide  is  too  concentrated, 
the  blue  colouration  changes  through  various 
shades  of  green  into  a  brown  tint. 

Iodine,  Sodium  thioetdphate,  and  Sodium  araenOt, 

Decinormal  solutions  of  these  reagents  are 
frequently  used  in  conjunction  with  one  another. 
The  reaction  between  iodine  and  sodium  thio- 
sulphate  is  essentially : 

2Na,S,0,+I,  =  Na,S40,-f2NaI 

although  under  certain  circumstances  oxidation 
to  sulphate  proceeds  to  a  small  extent,  even  at 
the  ordinary  temperature  (Pickering).  When 
usinff  deeinormal  solutions  the  end-point  is 
readily  indicated  by  the  appearance  or  disr 
appearance  of  the  yellow  colour  of  the  iodine, 
provided  the  solution  nnderpoing  titration  is 
not  unduly  diluted  and  is  otnerwise  colourless. 
The  production  of  a  blue  colour  when  free 
iodine  and  starch  solution  are  brought  together 
is,  however,  much  more  sensitive,  and  is  the 
method  usually  employed  in  ascertaining  the 
end-point. 

Preparation  of  starch  sohUion. — ^About  1  gram 
of  powdered  starch  is  rubbed  into  a  paste  with 
a  httle  cold  water,  and  slowly  added  to  200  o.o.  of 
boiling  water,  the  boiling  is  continued  for  two 
or  three  minutes,  the  solution  cooled,  and  after 
some  hours  the  clear  liquid  is  decanted.  The 
solution  will  only  keep  for  one  or  two  days, 
unless  sterilised,  when  it  is  conveniently  pre- 
served in  small  bottles,  completely  filled  and 
closed  by  soft  rubber  stoppers ;  it  will  then 
keep  indefinitely.  Starch  paste  prepared  from 
Oastine's  formula  (5  crams  starch,  0-01  gram 
merouric  iodide*  and  I  litre  water)  retains  its 
sensitiveness  for  a  long  time.  Addition  of  1  o.o« 
of  oil  of  cassia  to  a  litre  of  starch  liquoi  is  also 
recommended  as  a  preservative. 

Sensitiveness  of  the  iodine-starch  reaction, — 
This  depends  upon  several  oiroomstanoes.  It 
is  necessary  to  work  with  cold  solutions,  pre- 
ferably neutral  or  slightly  acid;  the  presence 
of  mineral  add  in  high  concentration  greatly 
impairs  the  sensitiveness  of  the  reaction,  since 
it  nvdrolyses  the  starch.  It  is  essential  that 
a  soluble  iodide  should  be  present  (osoally  this 
is  potassium  iodide)  in  moderate  amount ;  the 
be^  concentration  of  potassium  iodide  to 
employ  is  about  N/160,  since  the  sensitiveness  of 
the  reaction  then  reaches  a  maximum  (sesZeitsch. 
anal.  Chem.  1902,  41,  485;  Amer.  J.  Sci.  1900, 
[iv.]  10,  151 ;  J.  Amer.  Chem.  Soo.  1909,  31, 
1038). 

Good  starch  solution  first  yields  a  pink 
colouration  with  iodine,  which  more  icKiiae 
develops  into  the  blue  colour;    starch  which 


produces  green  tiaU  should  be  rejected  (J.  Amer. 
Chem.  Soa  1908,  30, 31).  It  frequently  happens 
in  titrating  arsenious  and  antimonious  oxides 
with  iodine  that  various  tints  of  red  make  their 
appearance  instead  of  the  usual  blue  coloura- 
tion. This  is  due  to  impurity  in  the  starch  :  in 
such  a  case  one  or  two  grams  of  potassium  iodide 
are  added,  the  end-point  being  ascertained  from 
the  development  of  the  yellow  colour  of  the  iodjne, 
and  then  confirmed  by  the  starch  (Amer.  J.  Sci. 
1902,  [4]  13,  379). 

Sinnatt  (Analyst,  1910,  35,  309)  has  shown 
that  1  C.C.  of  a  dilute  aqueous  solution  of 
methylene  blue  (0*05  gram  peiL  litre)  may  be 
used  in  place  of  starch  as  an  indicator  in  iodi- 
metiio  titrations  {see  also  Analyst,  1912,  37* 
262^ 

For  the  iodine  solution  25  grams  of  potassium 
iodide  are  dissolved  in  a  little  water,  12*7  grams 
of  commercial  iodine  added,  and  the  mixture 
shaken  till  the  iodine  has  dissolved ;   the  solu- 
tion   is    then    filtered    throueh    asbestos    and 
diluted  to  1  litre.    It  should  be  kept  in  the 
'dark,  and  protected  from  dust.     For  the  ihio- 
\sulphaie  solution  the  crystalline  salt  Na^,Ot» 
|5H|0   VB   dissolved   in   distUled    water,    using 
25  grams  per  litre,  and  the  solution  kept  away 
j  from  direct  sunlight  for  two  weeks  before  it  is 
standardised.     It    then    retains    its    titre    for 
I  months.    For  the  sodium  arsenite,  4*948  grains  of 
I  resublimed  arsenious  oxide  are  dissolved  in  s 
little  warm  sodium  hydroxide  free  from  iron, 
the  solution  rinsed  into  a  litre  flask,  and  made 
just  acid  to  phenolphthalein  with  dilute  sul- 
,  ^3hurio  acid.    A  filtered  solution  of  20  grams  of 
sodium  bicarbonate  in  500  c.c.  of  water  is  added, 
and  if  the  mixture  reacts  alkaline  to  the  phenol- 
iphthaleln,  sulphuric  acid  added  till  the  pink 
I  colour  disappears.    This  solution,  iHien  diluted 
I  to  1  litre  ana  thoroughly  mixed,  is  strictly  deci- 
normal, and  keeps  indefinitely.    A  measured 
quantity  of  the  N/IO  -arsenite  solution  is  delivered 
I  into  an  Erlenmeyer  flask,  and  the  iodine  solu- 
tion run  in  from  the  burette  until  present  in 
slight  excess,  starch  paste  being  adc&d  nearly 
at  the  finish  of  the  titration  {see  remarks  on 
starch  above).    The  reaction 

i  As,0.+2Is+2H,0  ^  As,0«+4HI 

proceeds  to  completion  in  the  sense  of  the  upper 
arrow  in  neutral  solution,  a  condition  secured 
by  the  presence  of  the  bicarbonate,  which 
neatralises  the  hydriodio  acid  produced.  Since 
•the  solution  should  be  saturated  with  carbon 
dioxide,  it  is  advisable  to  stopper  t^e  flask 
except  when  actually  introducing  the  iodine 
(J.  Amer.  Chem.  Soc  1908,  30.  31). 

The  iodine  bein^  standardised,  the  thio- 
•ulphate  can  be  directly  titrated  against  it, 
preferably  by^  running  the  iodine  into  a  measured 
volume  of  thiosulphate. 

Many  alternative  methods  have  been  pro- 
posed for  standardising  iodine  and  thiosulphate 
solutions.  The  latter  may  be  titrated  against 
pure  iodine :  0*5  gram  of  pure  iodine  and  0*1  gram 
of  potassium  iodide  are  powdered  and  mixed 
together  in  a  porcelain  djsh,  and  heated  on  a 
sand-bath  till  vapour  is  copiously  evolved ;  the 
dish  is  then  covered  with  a  dry  watoh-slass,  and 
the  greater  part  of  the  iodine  sublimed  on  to  it. 
The  watch-glass  is  covered  with  a  second  aooa- 
rately  fitting  glass  and  the  whole  weighed,  the 


ANALYSIS. 


271 


w«ght  of  thtt  glasses  ha^'ing  been  previously 
foond.  The  whole  is  gently  placed  in  a  solution 
61 1  gram  of  potassium  iodide  in  lOcc.  of  water, 
and  after  a  i^w  seconds  the  solution  is  diluted 
to  100  CO.  and  titrated  with  the  thiosulphate. 

The  thiosulphate  may  also  be  standardised 
against  permanganate,  itself  verified  by  reference 
to  sodium  oxalate.  One  or  two  grams  of  potas- 
sium iodide  are  dissolved  in  water,  acidifiea  with 
6  O.C.  of  hydroohlorio  acid  (1:6)  and  26  cc.  of 
standard  permanganate  added.  The  iodine, 
which  is  quantitatively  liberated : 

Mn,Of  +  lOHI  «  2MnO  +  5H,0+6It 
is  then  titrated  with  the  thiosulphate,  after 
diluting  the  solution  to  100  co.  By  the  reverse 
process  of  calculation,  a  permanganate  solution 
may  be  standardised  against  a  thiosulphate 
solution  that  has  been  verified  by  either  of  the 
preceding  methods  {see  Standardiaaiion  of  per- 
manifanaU;  c/.  Annalen,  1897«  198, 333 ;  Zeitsch. 
angew.  Chem.  1904,  17,  816 ;  Ann.  Chim.  Anal. 
1904,  0»  366;  Zeitsch.  anorg.  COiem.  1906,  49, 
277). 

(For  the  use  of  potassium  dichromatein  this 
connection,  see  Voiumelric  estimation  of 
ekromium:  Zeitsch.  anorg.  CSiem.  1899,  19, 
427;  1906,  49,  277.  See  also  Copper  under 
Vohmeirie  estimations.  For  a  pavimetrio 
method  for  standardising  iodine  solution,  consult 
Amer.  J.  SoL  1909,  (iv.)  28,  33.) 

Titanous  chloride. 

Hub  reagent,  introduced  into  volumetric 
analysis  by  &iecht  (J.  Soc.  Dyers  and  Golourists, 
19,  No.  6;  Ber.  1907,  40,  3819),  is  a  powerful 
ledndnff  agent.  For  example,  a  hydrochloric 
add  solntion  of  ferric  chloride  is  quickly  and 
quantitatively  reduced  in  the  cold,  according  to 
the  eqaation : 

FeQ,  +  Tia,  -  Fea,  +  TiQ* 
and  the  end-point  is  reached  when  a  drop  of 
the  liquid  coaaes  to  produce  a  red  colouration 
with  potaanmn  thiocyanate.  Chromic  acid  and 
eoprie  salta  may  be  similarly  estimated,  and 
also  a  large  nnmoer  of  organic  dyes. 

Fifty  O.C.  of  the  commercial  20  p.c 
solution  of  titanous  chloride,  which  usually  con- 
taina  a  little  iron,  are  mixed  with  an  equal 
volume  of  concentrated  hydrochloric  acid,  boiled 
for  several  minutes,  and  diluted  to  1  litre  with 
air-free  water.  The  solution  must  be  kept  pro- 
teoted  from  the  air;  a  convenient  method  is 
figured  in  Sutton's  Volnmetric  Analysis  (9th  ed. ), 
p.  224. 

Tli0  oonoentration  of  the  solution  is  fixed 
by  titmiing  against  a  known  quantity  of  either 
ferrio  salt  or  potassium  dichromate.  In  the 
former  case  36  fnmM  of  pure  ferrous  ammouium 
snlidiate  are  dissolved  m  dilute  sulphuric  acid 
ana  the  solntion  diluted  to  1  litre ;  26  cc'  are 
tlien  exactly  oxidised  with  dilute  permanganate, 
and  the  resolting  ferric  sulphate  titratS  with 
tlM  titanous  ohlonde  until  a  drop  of  the  solution 
no  longer  givee  a  red  colour  with  potassium 
tluooyanate.  Instead  of  using  this  'spot-out' 
method,  10-20  co.  of  10  p.o.  potassium  thio- 
eyaaato  mav  be  added  to  the  ferric  solution. 
B  the  itanoardisation  be  effected  with  potas- 
anun  dichromate,  addition  of  the  indicator  to 
the  solntion  itsdf  is  inadmissible.  Nearly  all 
the  titanous  chloride  necesscoy,  may,  however, 


bo  added  at  once,  since  the  colour  changes, 
throuffh  orange  to  green  and  then  violet,  afford 
an  indication  of  the  end-point.  Drops  of  solu- 
tion are  removed  for  testing  when  the  green 
colour  has  just  disappeared  (J.  Soc.  Chem.  Ind. 

1908,  27,  673). 

Pure  ferric  alum,  the  preparation  of  which 
is  described  by  Be  Koninck  (Bull.  Soc.  chim.  Belfl. 

1909,  23,  222),  might  also  be  employed  for  this 
standardisation. 

For  a  number  of  estimations  it  is  necessary 
to  employ  titanous  sulphate  instead  of  the 
chloride. 

Stannous  chloride. 

This  reagent  has  long  been  employed  as  a 
reducing  agent,  but  the  closely  alli^  and  more 
powerfully  reducing  titanous  salts  appear  to  be 
displacing  it.  Ferric  salts  are  easuy  reduced 
in  hot  acid  solution : 

2Feaa  +  SnG,  =»  SnQ^  -f  2FeCl,. 

Iodine  in  cold  acid  solution  oxidises  it 
quantitatively : 

2Snaa  +  21,  B  Snif  -f  SuCIa. 

Ten  grams  of  pure  tin  in  thin  pieces  are 
heated  with  200  co.  of  concentrated  hydro- 
chloric acid  in  a  platinum  dish  until  dissolved : 
or  a  glass  flask  ma^  be  used  with  a  piece  of 
platinum  foil  touching  the  tin  to  promote  its 
speedy  solution.  The  solution  is  diluted  to 
1  litre,  and  preserved  out  of  contact  with  the 
air. 

The  solution  is  best  standardised  by  that 
process  for  which  it  is  afterwards  to  be  employed, 
6.^.  if  required  for  iron  estimations,  by  titration 
aeainst  a  known  amount  of  ferric  chloride. 
The  latter  may  be  obtained  by  dissolving 
10-03  grams  of  bright  iron  wire  (99*7  p.c.  iron) 
in  hy&oohloric  acid,  oxidising  with  potassium 
chlorate,  expelling  the  excess  of  chlorine  by 
boiling,  and  diluting  the  solution  to  1  litre; 
26  cc  are  conveniently  used  for  titrating  the 
above  solution. 

Several  methods  have  been  proposed  for 
determining  the  end-point.  The  iron  solution 
containing  20-40  cc  of  concentrated  hydro- 
chloric acid  in  a  volume  of  126  cc  may  be 
titrated  nearly  at  the  boiling-point,  16  cc  of 
indicator  solution  (34  grams  i^gd, +0*06  gram 
Ft  as  chloride  per  litre)  being  added.  The 
end-point  is  reached  when  a  dark-oloud  of 
finely  divided  mercury  and  platinum  is  pro- 
duced (Amer.  Ghem.  J.  1893,  16,  360).  Or  a 
drop  of  the  solution  may  be  mixed  with  am- 
monium molybdate  on  a  white  plate;  the 
slightest  trace  of  stannous  salt  causes  a  blue 
cofouration.  An  alternative  is  to  add  a  slight 
excess  of  stannous  chloride,  and  titrate  back 
the  cold  solution  with  iodine. 

(For  the  standardisation  by  means  of  iodine, 
su  Volumetric  estimati<m  of  tin,) 

Silver  niiraUf  Sodium  chloride^  and  Am- 
monium thiocyanate. 

These  precipitation  reagents,  which  are  con- 
veniently made  of  decinormal  stren^h,  are  of 
great  service  for  the  volumetric  estimation  of 
silver,  copper,  mercury,  the  halogen  acids, 
cyanides,  and  thiocyanates. 

Silver  nitrate  is  used  either  in  neutral  or  in 
nitric  acid  solution.    In  the  first  caoe  potassium 


272 


ANALYSIS. 


obromate  is  employed  aa  indicator  when  haloffens 
are  being  estimated  (Mohr's  method).  Sflver 
chromate  is  decomposed  by  solutions  of  halogen 
salts  forming  silver  nalide  and  metallic  chromate ; 
consequently,  silver  chromate  cannot  permanently 
exist  m  the  solution  until  all  the  nalosen  has 
been  precipitated.  The  first  drop  of  silver 
nitrate  in  excess  then  produces  a  permanent 
precipitate  of  silver  chromate,  whicn  gives  a 
faint  red  tint  to  the  previously  pale-yellow 
liquid.  This  colour  change  is  more  readily 
observed  in  monochromatic  light  (from  a  power- 
ful sodium  flame).  One  or  two  drops  of  a 
10  p.o.  solution  of  potassium  chromate  aro 
added  to  the  solution,  v/bidh.  should  not  be 
unduly  diluted.  Silver  chromate  is  soluble  in 
mineral  acids  or  ammonia ;  hence  the  necessity 
for  working  in  neutral  solution.  An  alkaline 
solution  may  be  acidified  with  dilute  nitric  acid, 
and  then  neutralised  with  powdered  calcium 
carbonate.  Barium  must  be  absent  from  the 
solution,  since  it  jnrecipitates  the  indicator ;  it 
may  be  removed  with  sodium  sulphate. 

In  the  presence  of  nitric  aoid,  silver  nitrate 
and  ammonium  thiocyanate  solutions  are  used 
in  conjunction  (Volhard*s  method,  Annalen, 
1878,  190,  47).  The  addition  of  thiocyanate  to 
a  nitric  acid  solution  containing  silver  causes 
the  precipitation  of  white  silver  thiocyanate, 
and  the  end-point  is  indicated  by  the  red 
colouration  produced  by  the  interaction  of  the 
first  drop  of  thiocyanate  in  excess  with  a  ferric 
salt  previously  introduced  into  the  solution. 
The  thiocyanate  should  always  be  added  to  the 
silver  solution.  The  ferric  indicator  is  prepared 
b^  adding  nitric  acid  (4 : 1  boiled  to  expel 
nitrons  acid)  to  a  saturated  solution  of  iron 
ahim  until  colourless ;  5-10  0.0.  are  used  in  the 
titration. 

Standard  sodium  chloride  solution  is  used 
for  the  estimation  of  silver  by  the  very  exact 
method  originally  due  to  Gay-Lussac.  (For  a 
description  of  the  method,  v.  Abbatino.  ) 

Decinormal  silver  nitrate  is  obtained  by  dis- 
solving 16-99  grams  of  the  puro  di^  reerystal- 
lised  mlver  nitrate  in  water  and  diluting  the 
solution  to  1  litre.  If  it  is  to  be  used  m  con- 
junction with  the  thiocyanate,  this  solution 
may  also  be  prepared  by  dissolving  10-788  grams 
of  puro  silver  in  a  slight  excess  of  nitric  acid, 
boilm^  till  nitrons  acid  is  expelled,  and  diluting 
to  1  litre. 

The  thiocyanate  is  prepared  approximately 
decinormal  by  dissolving  the  salt  in  distilled 
water  (8  grams  per  litro),  and  is  standardised 

Xinst  the  silver  nitrate  solution,  25  cc.  ol 
ch  aro  diluted  to  100  OiO.  and  titrated  as 
described  above. 

VoLUMSTBio  EsmiATioirs. 

AhunininilL  lodimetrieaUy.  The  neutral 
solution  is  boiled  with  excess  of  potassium  iodide 
and  potassium  iodate  for  twenty  minutes  in  a 
stream  of  hydrogen;  the  iodine  evolved,  and 
collected  in  potassium  iodide,  toflether  with  that 
which  remains  in  the  distilling  flask,  is  titrated 
with  JV/lO-thiosulphate  (Amer.  J.  Sci.  1905,  20, 
181 ;  Zeitsch.  anoig.  Chem.  1907,  62,  286)  : 

Al,(S04),-f5KI+KI03-|-3H»0 

-  2Al(OH),+3K,SO^+8Tr 
Antimony.  ANnifONious  soLunovs.  (a)  lodi- 


metrieaUy.   One  or  two  orams  of  Rochelle  sal^ 
aro  Baaed,  the  solution   made  alkaline  with 
sodium  bicarbonate,  and  titrated  with  JV/IO- 
iodine.     I,  a  8b  (v.  Absshio). 

(&)  By  oocidaium.  The  hot  hydrochloric  aoid 
solution  (above  60*)  is  titrated  with  A'/lO-potas- 
sium  bromate,  which  has  been  standardised 
against  a  known  amount  of  pun  antimony — 

3Sba,-hKBrO,H-6Ha«3fiba,-*-KBr+3H,0. 

The  end-point  is  indicated  by  the  bleaching  of 
a  few  drops  of  methyl  orange  added  to  the  hot 
solution  (Ghem.  Zeit.  1903,  27,  740;  J.  80c 
Chem.  Ind.  1906,  25,  1181 ;  Chem.  News,  1907, 
95,  49). 

(e)  By  oxidation.  The  cold  solution,  freelv 
acidified  with  hydrochloric  aoid,  is  titrated  with 
^/10-permanganate  (Zeitsch.  angew.  Chem.  1901, 
14,  1179 ;  J.  Amer.  Chem.  Soc  1907,  29,  66). 

Aktdiokio  solutions  (a)  By  redubtion  to 
the  tervalent  state,  and  estimation  by  one  of 
the  foregoing  processes.  Reduction  may  be 
accomplished :  (i-)  by  boiling  the  hydrochloric 
acid  solution  witk  somum  sulphite  or  sulphurous 
acid  (Zeitsch.  angew.  Chem.  1888,  155) ;  accord- 
ing  to  Rohmer,  the  reduction  is  not  quanti- 
tative unless  a  gram  of  potassium  bromide  is 
added  (Ber.  1901,  34,  1565);  (iL)  by  boiling 
the  sulphuric  acid  solution  (100  0.0.  oontatning 
5  cc.  of  concentrated  acid  and  4  grams  of  Rochelle ' 
salt)  with  10-1*5  grams  of  potassium  iodide  till 
nearly  all  the  fodine  is  expelled,  exactly  bleach- 
ing the  remainder  with  dilute  sulphurous  acid, 
diluting,  rapidly  coolinff,  and  neutralising.  The 
solution  is  then  titratea  in  bicarbonate  solution 
with  i^/10-iodine  rAmer.  J.  Sci  1892,  42,  213). 

(6)  lodimdricaUy,  The  cold  solution  con- 
taining 20-25  o.a  of  hydrochloric  acid  in  a 
volume  of  100  cc,  is  mixed  with  0*5-1 0  gram 
of  potassium  iodide  and  the  liberated  iodine  ti- 
trated with  iV/10-thiosulphate.  I,  —  Sb  (Zeitsch. 
anorg.  Chem.  1908,  ^8,  202 ;  of.  tffid.  1903,  37* 
337). 

Anenie.  Abssnious  bolvtiohs.  lodimetri' 
caUy.  The  solution,  containing  sodium  bicarbo- 
nate ui  excess,  is  titrated  wiw  JY/lO-iodine  as 
described  under  the  standardisation  of  iodine 
solution.  The  bicarbonate  mav  with  advantage 
be  replaced  by  disodium  hydrocen  phosphate 
(J.  Amer.  Chem.  Soc  1908,  30,  31). 

Absshio  solutions,  (a)  By  reduction  with 
hydriodic  aoid  as  described  under  ArUinumy,  and 
subsequent  titration  with  iodine;  no  Rochelle 
salt  is  necessary  (Amer.  J.  ScL  1900,  10,  151). 
Reduction  maj  also  be  effected  by  heating  the 
sulphuric  acid  solution  with  sulphurous  acid 
in  a  stoppered  bottle  for  an  hour,  diluting  and 
boilin^c  down  to  half  the  volume  to  expel  excess 
of  sulphurous  acid  (Zeitsch.  anaL  Chem.  1883, 
22,  378;  Chom.  NewB,  1886,  53,  221). 

^  (&)  By  precipilation.  The  neutral  or  acetic 
aoid  solution  is  precipitated  with  excess  of  sflver 
nitrate,  and  the  pedpitated  sflver  arsenate 
collected,  washed,  dissolved  in  nitric  acid,  and  the 
sflver  titrated  with  i^T/lO-thiocyanate.   8Ag»As. 

(e)  lodimetrieaUy  (Zeitsch.  anal.  Chem.  1906, 
45,  596 ;  compare  Amer.  J.  ScL  1900,  10,  151). 
(See  also  Zeitsch.  anorg.  Chem.  1909,  62,  123, 
for  a  method  suitable  for  small  quantities  of 
arsenic.) 

Barinm.  lodimetrieaUy,  Excess  of  potas- 
sium iodate  is  added  to  the  faintly  ammoniacal 


ANALTSia 


273 


aolotioii,  the  preoipitatad  iodate  washed  wiih  j 
ammonia  and  then  with  alcohol,  dissolved  in 
hydrochloric  acid  and  potassium  iodide,  and  the 
iodine  titrated  with  ^/lO-thiosulphate.  6I|=Ba 
(J.  Amer.  Chem.  Soo.  1909,  31,  43). 

Blmilth.  (a)  lodimdrkaUy,  The  solution, 
as  free  as  possible  from  mineral  acids,  is  mixed 
with  excess  of  ^/2-potas8inm  ohromate,  shaken 
for  10  minutes,  oiluted  to  a  known  volume,  and 
the  chromate  in  an  aliquot  part  of  the  filtrate 
from  the  bismuthyl  chromate  Bi|09*2CrOs  is 
titrated  iodimetrically  (Zeitsch.  anore.  Chem. 
1902,  32,  362 ;  Zeitsch.  anal.  Chem.  1907,  46, 
223). 

(b)  As  hUmuOi  ammonium  molybdait  (J.  Amer. 
Chem.  Soo.  1903,  26,  907). 

Boron,    (a)  v.  Agidocetbt  ahs   Aijkali- 

MBTBY. 

(()  lodimeiricaUy.    The  reaction 

6KI+KIO,+6HBOa-3I,+3H,0+6KBO, 

is  quantitative  in  a  solution  saturated   with 
mannitol  (v.  Amer.  J.  Sci  1899,  8,  127). 

Bromine  v.  Halogens. 

Calelnm.  Bv  oxuUUum,  The  oxalate,  preci- 
pitated from  a  hot  slightly  ammoniaoal  solution 
(see  Oravimdric  methods),  is  washed  with  warm 
water  till  free  from  ammonium  oxalate,  decom- 
posed with  hot  dilute  sulphuric  acid,  and  the 
oxalic  acid  titrated  with  J\r/10-permanganate. 
The  precipitate  may  also  be  dissolved  in  dilute 
hydrochloric  acid,  0-5  gram  of  manganese  sul- 
phate added,  and  the  solution  titrated  with 
permanganate  {v,  Amer.  Chem.  J.  1905,  33,  500). 

CarMn.  Cabboit  diozids.  v.  Acidimxtbt 
and  AlbSllimetby,  and  Oas  analysis. 

Ctaitoobn  acids.  Ctaitates.  The  cold,  dilute 
solution  is  exactly  neutralised  with  N/lO-hydio- 
chloric  acid  (using  methyl  oranse  or  coneo  red 
as  indicator),  excess  of  acid  is  added,  the  solution 
boiled  for  ten  minutes,  cooled  and  titrated  back 
i\r/10-sodinm  hydroxide.  Excess  of  ?^/10-sodinm 
hydroxide  is  then  added,  the  solution  boiled  to 
expel  ammonia,  and  titrated  back  with  N/IO- 
hydrochloric  acid.  From  these  data  two  values 
for  the  cyanate  can  be  calculated,  which  serve 
to  check  one  another  (Chem.  News,  1906,  93, 
6 ;  compare  Zeitsch.  angew.  ChenL  1901,  24, 
585 ;  J.  Soc.  Chem.  Ind.  1904,  23,  244). 

KCN0+2Ha-f  H,0  »  Ka+NH4a-f  CO,. 

Ctahidbs.  (a)  By  precipitation.  (L)  Excess 
of  ^/10*silver  nitrate  is  added  to  the  neutral 
2^nide  solution,  and  then  a  little  nitric  acid. 
The  excess  of  silver  is  titrated  with  ^/10-thio- 
cmnate  after  filtering  off  the  silver  cyanide. 
(iL)  The  slightly  alkaline  solution  is  titrated 
with  i\r/10-8ilver  nitrate  with  constant  stirring 
till  a  permanent  turbidity  is  produced  (Lie big, 
Annalen,  1851,  77»  102).  This  marks  the  end 
of  the  reaction: 

2KCN+ AgNOs = KNO,  4-KAg(CN),. 
The  end-point  is  best  observed  by  adding  5-10 
drops  of  20  p.0.  potassium  iodide  as  an  indicator. 
A  jpennanant  yellow  turbidity,  due  to  silver 
iodide,  is  produced  as  soon  as  the  above  reaction 
is  completed  (Ann.  Chim.  Phys.  1895,  (vii.)  6, 
381). 

(&)  See  Ferrocyanides  (b). 

Febbiotanides.  (a)  The  salt  is  reduced  to 
ferrocyanide  by  boiling  with  sodium  hydroxide 

Vou  L— T. 


and  ferrous  sulphate  and  the  filtered  solution 
strongly  acidified  with  sulphuric  acid  and  titrated 
with  /^/lO-permanganate  {v.  Ferrocyanides). 
Reduction  may  also  be  effected  by  boiling  with 
sodium  peroxide  (Arch.  Pharm.  232,  226). 

(6)  iodimetrically.  The  neutral  solution  (50 
c.c.)  is  mixed  with  3  grams  of  potassium  iodide 
and  1*5  grams  of  zinc  sulphate,  the  mixture  well 
shaken,  and  the  iodine  titrated  with  ^/10-thio- 
sulphate.  2K,Fe(CN)f  «I,  (Zeitsch.  anorg.  Chem. 
1910,  67,  418  ;   compare  ibid.  67,  322). 

Febbocyahidss.  (a)  By  oxidation.  The  solu- 
tion is  strongly  acidified  with  sulphuric  acid 
and  titrated  with  A'/lO-permanganate  till  the 
colour  changes  from  yellowish-green  to  yellowish- 
red.  If  any  difiSculty  is  experienced  in  deter- 
mining the  end-point,  a  drop  of  the  solution 
may  be  mixed  with  dilute  ferric  chloride.  A 
blue  colour  will  develop  whilst  any  ferrocyanide 
remains  (de  Haen,  Annalen,  1854,  90,  160 ; 
compare  Zeitsch.  anorg.  CHiem.  1910,  67,  418). 

An  excess  of  permanganate  may  also  be 
addedfthe  excess  bemg  determined  iodimetrically. 
(For  details,  consult  Zeitsch.  anorg.  Chem.  1910, 
67,  322.) 

(6)  By  conversion  into  hydrocyanic  acid.  The 
ferrocyanide  solution  is  boiled  for  five  minutes 
with  10  C.C.  of  ^-sodium  hydroxide  and  15  c.a 
of  3i\r-magneeium  chloride,  1(X)  cc.  of  boiling 
^/lO- mercuric  chloride  are  then  added,  and  the 
boilinff  continued  for  ten  minutes.  The  mercuric 
cyanide  produced  is  distilled  for  thirty  minutes 
with  30  cc.  of  3^-sulphuric  acid,  the  prussio 
acid  collected  in  25  cc.  of  ^-sodium  hydroxide, 
a  little  potassium  iodide  added,  and  the  cyanide 
titrated  with  i\r/10-silver  nitrate  (Feld,  Chem. 
Zentr.  1903,  ii.  1398 ;  Analyst,  1908,  33,  261 ; 
1910,  35,  295). 

l^ocTAKATES.  (a)  By  precipitation.  As  in 
standardising  ammonium  thiocyanate  solution; 
the  thiocyanate  must  be  added  to  the  silver 
nitrate,  and  not  vice  versd,  since  nitric  add 
decomposes  thiocyanates. 

{b)  By  oxidation.  The  thiocyanate  is  ti- 
trated in  concentrated  hydrochloric  acid  solu- 
tion with  potassium  iodate,  in  a  stoppered 
bottle,  with  vigorous  shaking.  The  end-point 
is  reached  when  5  cc  of  chloroform  previously 
introduced  are  no  longer  coloured  by  iodine 
(J.  Amer.  Chem.  Soc  1^8,  30,  760);  e.g. 

4CuCNS-f  7KI0,+ 14Ha 

=4CuS04+7Ka-f7ia-f4Ha+5H,0. 
Oxidation  in  dilute  sulphuric  acid  solution  with 
permanganate  is  untrustworthy. 

Cerium,  (a)  lodimetricaUy.  Ceric  oxide  is 
warmed  with  concentrated  hydrochloric  acid 
and  potassium  iodide  in  a  stoppered  bottle  till 
complete  solution  is  effected.  The  liberated 
iodine  is  then  titrated  with  ^/lO-thiosulphate 
(Bunsen,  Annalen,  1858,  105,  49;  also  Amer. 
J.  Sci.  1899,  8,  451). 
2CeO,-f8Ha-f  2KI  =  2Coa,+2Ka-fI,-f4H,0 

(b)  By  oxidation.  The  washed  oxalate  is 
suspended  in  hot  dilute  sulphuric  acid  and 
titrated  with  JY/lO-permanganate  {v.  Calcium: 
Zeitsch.  anal.  Chem.  1880,  19,  194 ;  Amer.  J. 
Sci.  1899.  8,  457). 

(c)  By  reduction.  The  cerium  is  oxidised  with 
sodium  bismuthate  in  boiling  sulphuric  acid 
solution  to  ceric  sulphate  and  the  filtered  solu- 


\: 


274 


ANALYSia 


tion  reduced  by  a  slight  excess  of  ierroas 
sulphate,  the  excess  being  titrated  with  N/10* 
permanganate.  Other  rare  earth  met-als  do  not 
interfere  (J.  Amer.  Chem.  8oa  1909,  31,  523 ; 
1910,  32,  642;  compare  Compt.  rend.  1899, 
128.  101 ;   Ber.  1900,  33,  1924 ;   Ber.  1903,  36, 

282).  ^ 

{d)  Other  methods  (Zeitsoh.  anorg.  Ghem. 
1907,  64,  104 ;   1908,  59,  71). 

Chlorine  «.  Ealogens, 

Chromliim.  The  chromium  should  be  in  the 
form  of  ohromate. 

(a)  lodimelricaUy,  The  chromate  solution  is 
acidified  with  hydrochloric  acid  (5  co.  of  concen- 
trated acid  per  100  c.c.  solution),  1  or  2  grams  of 
potassium  iodide  added,  and  the  covered  solu- 
tion allowed  to  stand  for  15  to  20  minutes.  It 
is  then  diluted  to  400-^00  co.  and  the  liberated 
iodine  titrated  with  ^/lO-thioenlphate.  3Ia«>2Gr. 
A  known  dichromate  solution  can  in  this  way  be 
used  to  standardise  sodium  thiosulphate  (J.  pr. 
Chem.  1868,  103,  362;  Zeitsch.  anorg.  Chem. 
1899,  19,  427 ;  1906,  49,  277 ;  Zeitsch.  angew. 
Chem.  1900,  1147). 

{h)  By  reduciion  (L)  with  ferrous  ammonium 
sulphate,  of  which  a  slight  excess  is  added  to 
the  chromate  solution  containing  sulphuric  or 
hydrochloric  acid,  the  excess  of  ferrous  salt  being 
then  titrated  with  .AT/lO-dichromate ;  (iL)  with 
titanous  chloride  (v.  PrtpcaraiUm  of  standard 
soiviums ;  J.  See.  Ghem.  Ind.  1908,  27,  673) ; 
(iii.)  with  arsonious  oxide  (Amer.  J.  ScL  189i9, 
1,  35). 

Chromium  in  chrome  steel.  Three  grams  of 
alloy  are  dissolved  in  35  co.  of  concentrated 
hydrochloric  acid,  and  the  excess  evaporated; 
150  c.c  of  strong  nitric  acid  are  added,  the 
boiling  continued  till  no  more  brown  fumes  are 
evolved,  when  all  chlorine  has  been  expelled. 
The  chromium  is  then  oxidised  by  adding 
10  grams  of  potassium  chlorate,  and  the  solution 
boiled  down  to  40  c.c  to  decompose  excess  of 
chlorate ;  100  c.c.  of  water  are  added,  and  one 
or  two  drops  of  hydrochloric  acid,  to  dissolve 
separated  manganese  dioxide  The  chromate 
Eolution  is  boiled  to  expel  chlorine,  cooled  and 
titrated  according  to  method  (b)  (i.)  above  (For 
other  methods,  see  J.  Amer.  Chem.  Soc  1905, 
27,  1550;  1908,  30,  1116;  J.  Soc.  Chem.  Ind. 
1907,  26,  1010;  Ghem.  News,  1904,  90,  320; 
91,  3;  also  Manganese  and  Vanadium  {v. 
infra),) 

Chromium  in  ehromite.  The  valuation  of 
this,  the  only  important  ore  of  chromium,  is 
usually  effected  by  a  volumetric  method;  the 
finely  powdered  ore  is  fused  with  sodium  per- 
oxide in  a  nickel  crucible;  and  the  chromate  in 
the  aqueous  extract  estimated  as  described 
above,  after  boiling  for  ten  minutes  to  decompose 
excefla  of  peroxide  {v.  J.  Soc  Chem.  Ind.  1896, 
15,  155,  436 ;  Chem.  Zeit.  1897,  21,  3 ;  Bull. 
Soc  Chim.  1909,  5,  1133;  Chem.  News,  1896, 
73,  1). 

Cobatt.  {a)  lodimetricaUy.  The  solution  is 
mixed  with  nydrogen  peroxide,  and  then  with 
sodium  hydroxide,  when  the  cobalt  is  preci- 
pitated as  sesquioxide  CogOa,  whilst  nickel  is 
simply  precipitated  as  green  hydroxide.  After 
boiling  for  a  minute,  the  olack  ppt.  is  dissolved  in 
hydrochloric  acid  and  potassium  iodide,  and  the 
iodine  titrated  with  iv/lO-thiosulphate  (CThem.  ' 
News,  IDOO,  82,  66,  73 ;    1903,  88,  184). 


{by  By  precipHation  with  ferrocyanide,  as 
describ?d  under  Nickel  (6). 

Croliimbiuin.  By  reduction  and  subsequent 
oxidation  {v.  Zeitsch.  anoig.  Ghem.   1909,  62, 

383). 

Coppef.    (a)  lodimeiricaUy.    The  solution  of 

cupric   salt   preferably   neutral  or  containing 

acetic  acid,  is  diluted  to  100  cc,  6  grams  of 

potassium  iodide  are  added,  and  the  liberated 

iodine   titrated  with  ^/10-thiosulphate,  using 

staroh  paste  as  indicator.    If  more  than  25  co. 

of  thiosulphate  are  required,  2-3  grams  more 

potassium  iodide  should  be  added  (Amer.  J.  ScL 

1907,  24,  65;    compare  J.  Amer.  Ghem.  Soo. 

1902,    24,    1082;     1905,   27,    1224;    see   also 

Methods  of  separation). 

2CUSO4+4KI  ->  2K^4+It+GuaI,. 

(()  Bv  titration  wOh  potassium  cyanide 
(SteinbeacU  process).  The  ammoniaoal  copper 
solution  is  titrated  with  potassium  cyanide 
until  colourless  (v.  Chem.  News,  1897,  76,  189; 
Methods  of  separation;  and  the  article  Cofpeb^. 

(c)  By  precipitation  as  thiocyanate  and  esti- 
mation of  the  precipitate  by  potassium  iodate 
in  hydrochloric  acid  soluti<Hi  (v.  Thiocyanates ; 
and  J.  Amer.  Chem.  Soc.  1908,  30,  760). 

{d)  By  oxidation.  The  oxalate  is  precipi- 
tated in  a  nitric  acid  solution  by  adding  excess 
of  ammonium  oxalate,  washea  and  titrated 
with  ^/10-permanganate  (Amer.  J.  ScL  1909, 27» 
448). 

(e)  By  reduction  to  cuprous  salt.  To  the 
sulphuric  or  hydrochloric  aoid  solution,  10-20 cc 
of  10  p.c.  potassium  thiocyanate  and  a  little 
ferrous  salt  are  added,  when  a  deep  red  ooloura- 
tion  is  produced,  since  ferrous  salts  in  aoid 
solution  are  partly  oxidised  by  cupric  salts. 
The  cold  solution  is  titrated  with  titanous 
chloride  until  the  red  colouration  is  destroyed 
(Chem.  Soc.  Trans.  1906,  89,  1491).  Or  a  slight 
excess  of  titanous  chloride  may  be  added,  and 
titrated  back  with  standard  ferric  alum. 

Fluorine.  AcidimetricaUy.  The  fluoride  is 
mixed  with  ten  times  its  weight  of  finely 
powdered  and  ignited  quarts,  and  decomposed 
by  warming  witn  concentrated  sulphuric  aoid ; 
the  silicon  fluoride  evolved  passes  through  a 
dry  U-tube  filled  with  glass  beads  and  immersed 
in  cold  water,  in  order  to  remove  sulphurio  aoid, 
and  is  then  absorbed  in  50  p.c  alcoholic  potas- 
sium chloride,  which  precipitates  silioio  aoid 
and  potassium  silicofluoride,  leaving  hydro- 
chloric acid  in  the  solution  : — 

3SiF4+2H,0  -  2H,SiF,+SiO, 
H,SiF,+2KCl «  K,SiF,+2Ha 

The  hydrochloric  acid  is  titrated  with  JT/S- 
sodium  hydroxide,  using  laomoid  as  indicator. 
2HC1  =  3'F..  (For  full  experimental  details, 
which  are  absolutely  essential  in  order  to  obtain 
accurate  results,  consult  Chem.  News,  1879,  39, 
179;  Amer.  J.  ScL  1906,  22,  329;  or  Low's 
Technical  Methods  of  Ore  Analysis.) 

Gold.  lodimelricaUy.  The  aurio  solution  is 
treated  with  potassium  iodide  in  more  than 
sufficient  quantity  to  dissolve  the  aureus  iodide 
first  precipitated,  and  the  iodine  liberated  is 
estimated  with  standard  thiosulphate  (Amer. 
J.  ScL  1899,  8,  261 ;  compare  2ieitsoh.  anorg. 
Chem.  1899,  19,  63). 

Halogens.  This  term  is  restricted  in  this 
connection   to  chlorine,   bromine,   and  iodine. 


ANALTSia 


276 


ftiorhie    being    treated    eeparatpiy,    since    its 


Fio.  13. 

analytical  reaotions  are  quite  different. 

EsTZHATiON  Of  HALOOSHS.  lodine  is  esti- 
mated by  solution  in  potassium  iodide  and  titra- 
tion with  ^/10-thio«ulphate,  using  starch  paste 
as  indicator  (v.  Preparation  of  stoMord  soliUiona, 
Bromine  and  chlorine  are  absorbed  in  potassium 
iodide  solution,  setting  free  an  equivalent 
quantity  of  iodine,  which  is  titrated  with  N/IO- 
wiosuiphate. 

A  luge  number  of  substances,  e.g.  peroxides, 
chlorates,  chromates,  &c.,  may  be  readily  deter- 
mined indirectly  by  distillation  with  oonoen- 
trated  hydrochloric  acid,  the  available  oxygen 
of  the  compound  setting  ftee  its  equivalent  of 
chlorine,  iiiuoh  is  absorMd  in  potassium  iodide. 


Fia.  14. 

and  the  liberated  iodine  titrated  with  iV^/10-thio- 
sulphate.  It  is  very  desirable  to  exclude  air 
in  the  process  of  distillation,  since  it  liberates 
iodine  from  the  hydrogen  iodide  set  free  in  the 
leeeiver,  by  the  hydrogen  chloride  distilling 
ovrr  during  the  experiment.  The  apparatus 
devised  by  Bunsen,  the  originator  of  this 
analytical  method,  is  shown  in  Fig.  13,  h.    The 


small  flask  (50  o.o.>  and  the  delivery  tube  are 
ground  at  their  junction  to  fit,  ana  the  joint 
made  with  caoutchouc  tubing;  a  ground-glass 
joint  is  better,  a  spring  holdmg  the  two  parts 
tightly  together.  The  mixture  is  rapidlv  boiled, 
the  cnlorine  passing  into  potassium  iocfide  con- 
tained in  the  retort,  the  size  of  which  must  be 
suitably  chosen  to  prevent  overflowing.  A 
different  receiving  vessel  is  shown  in  Fig.  13,  a. 
It  is  very  .convenient  to  perform  such  dis- 
tillations in  a  current  of  carbon  dioxide  or 
other  inert  gas,  and  various  designs  of  apparatus 
for  such  a  purpose  are  given  in  Amer.  J.  Sci. 
1898,  6,  168;  Chem.  News,  1899,  79,  85; 
Chem.  Soc.  Trans.  1892»  61,  87  ;  Zeitech.  angew. 
Ghem.  1890,  477. 

The  apparatus  shown  in  Fig.  14  (Analyst, 
1908, 33, 1 17)  admits  of  the  gradual  introduction 
of  a  liquid  reagent  during  distillation  in  carbon 
dioxide,  steam,  or  any  other  gas  or  vapour. 
Oontamination  of  the  reagents  with  oork  or 
indiarubber  derived  from  stoppers,  &o,,  is  avoided 
by  fitting  the  condenser  and  the  dropping 
funnel  to  the  distilling  flask  by  ground-glass 
joints. 

Estimation  ov  haloqens  m  HALma  salts. 
By  precipitation,  (i.)  Mohr^a  method.  The  neu- 
tral solution  is  titrated  with  ^/10-silver  nitrate 
in  the  presence  of  a  few  drops  of  potassium 
chromate  as  indicator  (v.  PreparcUion  of  standard 
solutions.  It  is  advisable  to  perform  a  blank 
experiment  under  identiciJ  conditions,  to  allow 
for  the  silver  nitrate  necessary  to  brins 
out  the  reddish  colouration.  (Il)  Vothard^s 
method.  The  nitric  acid  solution  of  the  halide 
is  precipitated  by  adding  a  slight  excess  of  N/IO" 
silver  nitrate,  the  excess  being  then  titrated  with 
^/10-ammonium  thiocyanato.  Silver  chloride 
must  be  filtered  off  before  the  latter  titration  is 
performed,  since  it  reacts  with  the  thiooyanate 
(J.  Amer.  Chem.  Soc.  1907,  29,  269;  compare 
Zeitsch.  anorg.  C^em.  1909,  63,  330);  but 
silver  bromide  and  iodide  do  hot  interfere.  It 
is  advisable  to  titrate  iodide  in  a  stoppered 
bottle  with  vigorous  shakins  when  adding  both 
the  silver  solution  and  tEe  thiocyanate,  to 
minimise  error  due  to  occlusion.  It  ia  more 
accurate  to  weigh  out  a  very  slight  excess  of 
pure  silver,  dissolve  it  in  nitaric  acid  (carefuUv 
expelling  nitrous  acid,  which  interferes  witn 
the  indicator),  and  add  to  the  halide  solution 
than  to  measure  out  i^T/lO-silver  nitrate.  After 
vigorous  shaking,  the  excess  of  silver  is  then 
titrated  with  a  dilute  thiocyanate  solution 
(1  C.C.  ss  1  milligram  Ag). 

Iodides.  iSlimetricaUy.  (i.)  A  sb'ght  excess 
of  potassium  iodate  is  added,  and  the  solution 
acidified  with  dilute  sulphuric  acid.  The 
liberated  iodine  is  extracted  with  chloroform, 
carbon  disulphide  or  toluene,  and  titrated  with 
2\^/10-thio8ulphate.  A  weaker  acid  than  sul- 
phuric acid  may  be  employed,  e.g,  aoetio  or 
tartaric  acid.  Five-sixths  of  the  iodine  found 
was  originally  present  as  iodide  (Chem.  Zeit.  1904, 
28, 1191 ;  Amer.  J.  ScL  1897,  3,  293  ;  J.  pharm. 
Chim.  1902,  16,  207;  J.  Amer.  Chem.  Soc. 
1903,  25,  1138).  This  method  is  available  in 
the  presence  of  bromide  and  chloride,  if  acetic 
acid  be  employed,  (ii.)  The  solution,  contain- 
ing the  iodide,  2  grams  of  pure  potassium  arsenate, 
and  10  C.C.  of  concentrated  sulphuric  acid,  is 
boiled  down  from  a  volume  of    100    cc.    to 


276 


ANALYSIS. 


35-40  o.o.f  when  all  the  iodine  is  expelled.  The 
anenions  ealt  in  solution  is  then  titrated  with 
^/lO-iodine  (Amer.  J.  ScL  1890,  39,  188).  As 
Blf  In  the  presence  of  chloride  the  results 
are  a  little  low ;  bromide  causes  them  to  be 
slightly  high,  (iii.)  {v.  Chem.  Soc.  Trans.  1885, 
47,  471.) 

Estimations  of  halogxns  m  ozyhaloobk 
coMPOXTims.  (a)  By  reduction  to  a  halide  salt 
and  determination  of  the  latter.  lodaUs  are 
reduced  by  adding  sulphurous  acid  to  the 
sulphuric  acid  solution  of  the  iodate  till  the 
separated  iodine  is  redissolved;  an  excess  of 
^10-silver  nitrate  is  added  to  precipitate  the 
iodide,  the  mixture  boiled  with  excess  of" 
nitric  acid,  and  finally  the  excess  of  silver 
titrated  with  2^/10-thiocyanate.  Bromates  and 
chlorates  are  reduced  by  adding  an  excess  of 
iron  filings  to  the  sulphuric  acid  solution ;  after 
an  hour,  excess  of  JV/10-silver  nitrate  is  added, 
the  mixture  boQed  with  nitric  acid  to  oxidise  the 
ferrous  salt*  and  the  exeess  of  silver  titrated 
(Amer.  Chem.  J.  1904,  32,  242). 

(b)  By  reduction  to  a  halide  salt  and  estima- 
tion of  the  reducing  agent  used  up  in  the  process. 
With  chlorates  ana  bromates,  the  sulphuric  add 
solution  is  boiled  for  ten  minutes  with  excess  of 
standard  ferrous  sulphate  in  an  atmosphere  of 
carbon  dioxide,  the  solution  cooled,  manganese 
sulphate  added  and  the  unchanged  ferrous  salt 
titrated  with  N/lO-KMnO^.  6Fe  =  aO,  or  BrO, 
(Zeitsch.  anorg.  Chem.  1904,  38, 110).  Bromates 
may  also  be  r^uced  with  arsenious  oxide  (Amer. 
J.  ScL  1902,  14,  285).  Chlorates  are  reduced  by 
adding  an  excess  of  ^/10-titanous  sulphate,  and 
after  three  minutes,  titrating  back  with  ferric 
alum  (J.  Soc.  Chem.  Ind.  1908,  27,  434). 

(c)  lodimeiricaUy.  Chlorates,  (i.)  By  dis- 
tillation with  concentrated  hydrochloric  add. 
GOt  »  3I|  {Bunsen*s  method ;  v,  EsHmation 
of  halogens  ;  Chem.  Soc.  Trans.  1892,  61,  87). 
(li)  By  reduction  with  concentrate  hydro- 
chloric acid  and  potassium  bromide  (Chem.  Zeit. 
1901,  25,  727),  or  with  potassium  iodide  and 

.dilute  sulphuric  add  in  presence  of  vanadyl 
sulphate  (Zeitsch.  anal  Chem.  1907,  46,  521). 
(For  other  methods,  see  Amer.  J.  Sd.  1891,  42, 
220;  J.  Amer.  Chem.  Soc.  1903,  25,  756; 
Zeitsch.  anal.  Chem.  1907,  46,  308.) 

Hypochlorites.  A  slight  excess  of  i\r/10-sodium 
araenite  is  added  and  the  excess  titrated  with 
^/10-iodine,  or  the  hypochlorite  is  directly  ti- 
trated with  the  anenite  till  a  drop  of  the  solution 
ceases  to  colour  starch-potasnum  iodide  paper 
blue.  As  ■■  QO  {Penot*s  method ;  compare 
Chem.  Zdt.  1904,  28,  59). 

Perchlorates.  The  concentrated  solution  is 
boiled  with  a  large  excess  of  titanous  sulphate, 
the  excess  oxidisra  with  permanganate,  and  the 
chloride  produced  is  titrated  as  usual  (Zeitsch. 
anorg.  Chem.  1909,  62,  108 ;   ChcuL  Zdt.  1909, 

83.  759). 

Bromates.  The  substance  is  digested  at  100* 
with  potassium  iodide  and  concentrated  hydro- 
chloric acid  in  a  stoppered  bottle,  and  the 
liberated  iodine  titrated  with  thiosulphate. 
BrO,  =  Zlg  (compare  Zeitsch.  anorg.  Chem.  1899, 
19,  427). 

lodates.  These  are  simply  added  to  a  slight 
excess  of  potassium  iodide  solution,  acidified 
with  sulphuric  or  hydrochloric  acid,  and  the 
liberated  iodine  titrated.     lOg  »  31,. 


EsTDfATIOim    IKVOLVIHO    MiXTXrBBS    OV  TBX 

FoBBOoiNO  Hjlijdb  Salts. 

Chloride,  Hypochlorite  and  Chlorate.  The 
solution  is  titrated  with  ^/lO- sodium  arsenite 
by  Penot's  method  for  the  hypochlorite;  the 
chlorate  is  then  estimated  in  the  solution,  altei 
acidifying  with  sulphuric  acid,  by  reduction  with 
standard  ferrous  sulphate,  and  the  total  chlorine 
then  titrated  by  Volnard's  method  (Compt.  rend. 
1896,  122,  449;  cf.  J.  Amer.  Chem.  Soc.  1909, 
31,  525,  1273). 

Chloride,  Chlorate  and  Perehlorate.  Chloride 
is  titrated  in  one  portion  of  the  solution  by 
Volhaid's  method,  and  in  another  portion  after 
reducing  the  chlorate  with  ferrous  sulphate. 
For  perehlorate  the  dry  substance,  mixed  with 
five  times  its  weight  of  pure  quarts  sand  and 
covered  with  a  layer  of  the  same  2  cm.  deep, 
is  fused  in  a  platinum  crucible  for  half  an  hour, 
cooled,  extracted  with  water,  and  the  total 
chloride  estimated  (Compt.  rend.  1896,  122, 
452). 

Chloride  and  Iodide.  The  total  halogen  \a 
titrated  by  a  suitable  method  in  one  portion  of 
solution,  and  the  chlorine  in  another  portion 
after  removing  iodine  by  one  of  the  following 
methods  (Amer.  J.  Sd.  1890,  89,  293).  (i.)  Tc 
the  neutral  solution  (400  c.c.)  is  added  10  0.0. 
sulphuric  acid  (1:1),  2  grams  ferric  sulphate, 
ana  3  cc.  nitric  acid,  and  the  whole  boiled  till 
all  iodine  is  expelled ;  1  c.o.  nitric  acid  is  again 
added,  and  the  solution  again  boiled,  (ii.)  The 
ferric  ^phate  and  nitric  acid  of  method  (l)  are 
replaced  by  2  grams  of  pure  sodium  nitnto  (or, 
failing  this,  by  passing  into  the  solution  the 
vapours  venerated  from  the  slightly  impure 
nitrite  and  dilute  sulphuric  add). 

Bromide  and  lodtde  (v.  supra.  Iodides). 

Bromide  and  Chloride.  The  solution  is  acidi- 
fied so  as  to  contain  25  cc  of  concentrated  nitric 
acid  in  a  total  volume  of  100  cc,  heated  to 
boiling  and  boiled  for  one  minute,  the  source 
of  heat  removed  and  air  sucked  through  the 
solution  until  it  is  perfectly  colourless  (and  for 
one  minute  longer).  The  bromine  is  then  com- 
pletely expelled ;  the  residual  chloride  is  titrated 
by  Volhud's  method.  The  total  halogens  are 
titrated  in  another  portion  of  solution  (J.  Soc 
Chem.  Ind.  1909,  28,  505). 

(For  a  very  accurate  but  more  elaborate 
method,  v.  J.  Amer.  Chem.  Soc.  1907,  29,  275 ; 
also  Zeitsch.  anorg.  Chem.  1895, 10, 387 ;  Zeitsch. 
anaL  Chem.  1900,  39,  81.) 

Chloride,  Bromide,  ana  Iodide,  (a)  The  iodide 
is  decomposed  with  potassium  iodate  and  aoetio 
acid,  the  iodide  extracted  with  chloroform  and 
titrated.  The  bromide  is  destroyed  by  boiling 
with  5^-nitric  acid,  any  iodate  remaining  is 
decomposed  with  a  slight  excess  of  potasdum 
iodide,  which  excess  is  readily  decomposed  bv 
boiling  with  nitric  add,  and  the  residual  chloride 
titrated.  The  total  halogens  are  titrated  in 
another  portion  of  solution  (J.  Amer.  C3iem. 
Soc.  1903,  25,  1138). 

{f>)  The  iodide  is  destroyed  by  boiling  with 
ferric  sulphate  and  sulphurio  add,  and  the 
amount  of  ferric  salt  reduced  is  determined  with 
^/10-dichromate.  The  total  halogens  are  deter* 
mined  by  Volhard's  method,  and,  in  another 
portion  of  solution,  the  iodide  is  removed  by 
adding  hydrogen  peroxide  and- acetic  add  and 


deacTibeu  under  Bromidt  and  Chioric  .     .. 
reflidual  MoruU  titrated  (J.  Soo.   Cbem.   tott. 
1909,  2B,  SOS). 

Irioiu  FiBSOtra  SALta.  Jty  oxidation,  (a) 
Tho  oold  Bolatioa  i*  •teonglv  acidi&ed  with  dilute 
mlplmrio  aoid  and  titntod  with  J^/lO-petmoa- 
g&nate.  Thii  gimple  and  >oaimt«  method 
reqailM  modificiatioQ  when  hydroohlorio  aoid  Ib 
preaent,  liiiae  it  rMOt*  with  permanganate. 
This  Bide-reaotion  oan  be  practicall?  prevented 
by  adding  a  moderate  qoantity  of  mangtuiMe 
iulphate  to  the  solution  and  titrating  vwy 
dowly.  A  eolation  is  prepared  as  follows : 
67  granu  of  orjetalline  mangnnese  tujphate  are 
disaolnid  in  water,  139  o.o.  of  phoaphorio  ooid 
(tp.Br.  1-7),  and  130  o.o.  oonoentrated  nilphurio 
•cid  (ip.gr.  1-S2)  ore  added,  and  the  mixture 
d£Dted  to  1  litre.  Of  this  eolntioo,  20  0.0.  are 
added  to  the  femnu  aolntion  to  be  titrated. 
^The  phosphorio  aoid  beepa  the  ferrie  aolution 
colovrleee,  and  Otos  facilitate*  the  observation 
of  the  eiuf-point  (Zeitsch.  an*L  Cbcm.  1863,  1, 
329 ;  Cbem.  Zeit.  1S89,  13,  323 ;  Amer.  Chem. 
J.  190S,  34,  109 ;  Analyet,  1908,  33,  43.  and 
1900,  34,  306). 

(b)  The  ooid  sedation  is  ozidued  by  N/IO- 
diohromate  as  deaoribed  ander  Preparation  of 
tta»dard  aolviions. 

Fnuuo  aujcs.  (a)  Bg  rtduelum  to  ferroos 
salt  and  titration  with  permancanate  or  di- 
chromate.  Reduction  may  be  effected  in  any 
of  the  following  ways :  (L)  The  sulpbario  ooid 
solution  is  heated  to  boiling  ana  hydrogen 
anlphide  passed  throogh  it  until  the  solution 
ia  completely  colourlem ;  the  excess  of  hydrogen 
■olphide  is  expelled  from  the  boilins  solution 
by  a  current  of  carbon  dioxide,  (ii.)  The  nearly 
neutral  solution  is  boiled  with  mlphntous 
acid  or  ammonium  sulphite,  exoess  being  re- 
moved by  continued  boiling,  preferably  in  a 
current  oi  carbon  dioxide,  (ill.)  Sight  or  ten 
grams  of  granulated  sine  are  added  to  the 
worm  Bul]£aria  acid  solution,  and  the  action 
allowed  to  ooutinne  until  a  drop  of  the  solution 
no  loDffsc  gives  a  eolouratioQ  with  potassium 
thiocyanate.     The   solution   is   cooled,    Blt«red 


Iron,  eth  ed.  04).  (iv.)  The  hydroohlorio  acid 
solution  is  heated  nesrlv  to  boilius,  and  staunoas 
chloride  (2S  p.c.  solution)  addea  drop  by  drop 
until  the  solution  is  colourlees ;  10  cc.  of 
saturated  meicnric  cbloridB  sre  added  to  deetrov 
excess  of  stannous  chloride,  the  solution  diluted, 
manganese  sulphate  added  (b.  mpra),  and  the 
ferrous  salt  titrated  with  iV/lO-permaugsnate 
[best  alter  the  addition  of  sboat  6  o.c.  of  water- 
glass  solution  of  sp.gr.  1'17]  (Analyst,  1909,  34, 
30e).  (v.)  Rtdvction  by  paSadium-kydrogen  in 
boiling  acid  solution  ;  this  introduces  no  foreign 
substance  inte  the  aolntion  (Zeitsch.  angew. 
Caiem.  1902,  IS,  398,  424  ;  Analyst,  1904.  29, 
346).  (vi.)  Stdudion  vnlh  iilanou*  tulphate 
(Amer.  J.  SoL  1908,  26,  343). 


chloric  acid  solution  of  t*ie  ferric  salt  is  titrated 
as  described  under  Prfparaiian  of  elandard 
solitlioM.  (ii.)  Stamoiu  chloride.  The  nearly 
boiling  bydrocblorio  solution  is  t.trated  aa  do- 


Fio.  18. 
scribed  nnder  Preparation  of  ttandard  lolulioiit, 
using  either  the    mercuric    chloride   indicator 
(Amer.  Chem.  J.  1893,  IS,  360)  or  titikting  back 

with  iodine. 

E^KBOUS  IBOH  in  HINSBALS  AMD  BOOKS.     ThO 

only  satisfactory  method  consists  in  dt 
posmg  the  coonely  powdered  subetanoe 
sulphurio  and  hydroauorio  aoids  in  on  i 
sphere  of  oarbon  dioxide,  and  titrating  the 
ferrous  salt  produced  [Cooke's  Method;  Amer. 
J.  Sci.  1867,  44,  347 ;  Its  also  Amer.  J.  Sci. 
1804,  48,  149).  The  old  method  of  heating  with 
dilute  solphurio  ooid  in  a  sealed  tube  (Mit«cht 
lioh)  is  worthless  in  the  preeenco  of  solphur 
galphides  (J.  AmM.  Chem.  Soc  1900,  22,  621, 
(For  an  exhaustive  discussion  of  this  problem, 
V.  Hillebrand's  Analysis  of  Silicate  and  Cwbooate 
Bocks.) 

Iron  and  Alutninium.  After  weighing  the 
ignited  sesquioxidea,  they  ore  brought  mto  solu- 
tion by  fusion  with  potajsium  hydrosen  sulphate 

"^d  potossiam  fluoride  (followed  by  evapom- 

witli  sulphurio  aoid),  and  the  iron  reduced 
and  titrated  (Zeitaoh.  augew.  Chem.  190fi,  16, 
816). 

/ran  and  Titaniian.  Wtrric  eolta  oan  be 
reduced    with    sulphurous    acid 

sulphide    without    reduoioe    tita    .    ,    ._ 

redTuotion  of  both  may  be  effected  with  zinc  and 
sulphuric  aoid,  the  titanout  salt  oxidised  with 
a  alight  excess  of  bismuth  oxide,  and  theferrotu 
salt  titrated  in  the  Sltered  solution.  To  estimate 
both  elements  present,  one  of  the  preceding 
methods  may  be  combined  witli  the  reduction 
prooeas  for  titeninm,  described  later,  which 
would  give  the  lolaJ  iron  and  lilanititn  (ti.  also 
J.  Soo.  Chem.  Ind.  1009,  28,  189;  Analyst, 
1910,  36,  193). 


r    hydrogen 


278 


ANALYSTS. 


IrOH  and  Vanadium.  Reduction  with  sul- 
phur dioxide  proceeds  with  the  yaoadium  as 
Utf  as  to  the  oxide  VsOf ;  reduction  with  zinc 
cairies  it  as  far  aa  VtO,;  hence  two  such 
reductions  and  titrations  with  permanganate 
furnish  data  for  calculating  both  iron  and 
▼anadlum  (Amer.  J.  ScL  1908,  26,  79). 

Lead.  By  precipUaiion  (i.)  As  molybdaU, 
The  boiling  acetic  acid  solution  is  titrated  with 
standard  ammonium  molybdate  (4*75  ^ams  per 
litre,  titrated  against  pure  lead)  until  a  drop 
of  solution  gives  a  brown  or  yellow  colour  with 
a  drop  of  dilute  tannic  acid  solution.  The 
indicator  not  being  very  sensitive,  a  *  blank ' 
experiment  should  be  made  and  the  necessary 
correction  allowed  for  both  in  an  assay  and  in 
standardising  the  solution,  (ii. )  As  ferroeyamde, 
Tlie  cold  acetic  acid  solution  is  titrated  with 
potassium  ferrocyanide  (10  ^ms  per  litre 
titrated  against  pure  lead)  until  a  drop  of  the 
solution  j^oduces  a  brown  colouration  with  a 
drop  of  saturated  uranium  acetate  solution; 
a  *  blank '  experiment  should  also  be  made 
(J.  Amer.  Chem.  Soc.  16,  560  ;^  CheuL  News, 
1896,  73, 18).  In  determining  lead  in  ores,  Ac., 
it  is  usually  separated  as  sulphate  and  dissolved 
in  ammonium  acetate  previous  to  titration. 
(For  a  comprehensive  review  of  methods  for  lead, 
V,  Chem.  News,  1903,  87,  40 ;  Gaz.  chim.  itaL 
1896,  26,  L  327  ;  see  also  Methods  of  separaiion; 
and  J.  Amer.  Chem.  Soc.  1903,  26,  632 ;  1904, 
26,  1136.) 

Magnesium,  (a)  AcidimetricaUv,  The  mag- 
nesium is  precipitated  as  the  double  ammonium 
phosphate,  the  precipitate  washed  with  dilute 
ammonia,  and  then  with  aqueous  alcohol  till  free 
from  extraneous  ammonia,  dissolved  in  a 
measured  excess  of  ^/10-hydrochloric  acid,  and 
the  excess  titrated  with  ^/10-sodium  hydroxide, 
using  methyl  oiaage  for  indicator : 

Mg(NHJP04+2Ha  =  Mga,+H,(NH4)P04 

(Chem.  Zentr.  1876,  727 ;  for  a  method  which 
obviates  the  use  of  alcohol,  v.  J.  Amer.  C]!hem. 
Soc.  1900,  22,  31 ;  see  also  Phosphorus). 

(b)  lodimetricaUy.  The  magnesium  is  pre- 
cipitated as  double  ammonium  arsenate,  dis- 
solved in  hydrochloric  acid  and  potassium  iodide, 
and  the  iodine  titrated  (J.  Amer.  Chem.  Soc. 
1899,  21,  746 ;  Zeitsch.  anaL  Chem.  1907,  46, 
714). 

Manganese,  (a)  By  oxidation  uM  pemum- 
ganaU,  {Volhard's  method,  modified,)  The  neutral 
chloride  or  sulphate  solution  containing  10  grams 
of  zinc  sulphate  is  heated  to  boiling,  1  gram  of 
freshly  ignited  zinc  oxide  added,  and  the  liquid 
titrated  with  iV^/lO-permanganate,  boiling  and 
shaking  frequently  until  the  supernatant  liquid 
is  red  ;  1  c.c.  pure  glacial  acetic  acid  is  added, 
and  the  titration  slowly  finished  with  jierman- 
ganate  in  the  hot  but  not  boiling  liquid.  The 
manganese  can  be  aoonratdy  calculated  from 
the  equation : 

3MnO+MnjOT  »  6MnOt 
(Zeitsch.  anaL  CSiem.  1909,  48,  761;  Little  and 
Cahen,  Analyst,  1911,  36,  62). 

(b)  By  precipitation  as  dioxide  and  estimation 
of  the  available  oxysen.  Precipitation  may  be 
effected  in  one  of  the  folio  wing  ways  :  (i.)  By 
addmg  bleaohing-powder  solut^n  and  ciadcium 
carbonate  to  a  hot  neutral  solution  of  the 
manganese    salt    containing    ferric    and    zinc 


j  chlorides  (Chem.  Soc.  Trans.  1879,  35,  366 ; 
J.  Soc.  Chem.  Ind.  1891,  10,  333).  (iL)  By 
boiling  the  solution  in  concentrated  nitric  acid 
(quite  free  from  any  hydrochloric  acid)  with 
potassium  (or  preferably  sodium)  chlorate, 
(iii)  By  boilmg  the  dilute  sulphuric  acid  solu- 
tion with  ammonium  persulphate  (Zeitsch. 
angew.  Chem.  1901,  14,  1149 ;  1903,  IB,  906 ; 
Compt  rend.  1902,  136,  966 ;  1903,  136,  449). 
The  washed  precipitate  in  either  case  ia  dis- 
solved in  a  sulphuric  acid  solution  of  standard 
ferrous  sulphate  or  oxalic  acid,  and  the  excess 
of  reagent  titrated.  The  precipitate  obtained 
by  method  (ii.)  is  deficient  in  available  oxygen 
(Amer.  J.  ScL  1898,  5,  260),  and  the  standard 
solution  employed  in  the  filial  titration  must 
therefore  be  standardised  on  a  known  amount 
of  manganese  treated  in  a  simflar  fashion. 

(c)  By  conversion  into  permanganie  add, 
(L)  The  cold  solution  free  from  hydrochloric 
acid,  and  containing  one  quarter  its  volume  of 
nitric  acid  (specific  gravity  1*42),  is  oxidised  by 
shaking  with  2-4  grams  of  sodiunf  bismnthate 
for  throe  minutes,  diluted  ^ith  half  its  volume 
of  3  p.c.  nitric  acid,  the  solid  residue  allowed 
to  settle,  and  the  permanganic  add  solution 
filtered  into  a  slight  excess  ol  ferrous  sulphate ; 
excess  of  the  latter  is  then  titrated  with  N/IO' 
permanganate  (DingL  poly.  J.  269,  224 ;  Chem. 
Soc.  Trans.  1896,  67,  268 ;  Chem.  News,  1901, 
84,  209,  247;  J.  Amer.  Chem.  Soc.  1904,  26, 
793).  (iL)  The  oxidation  of  small  quantities  of 
manganese  may  be  effected  by  boilinff  the  nitric 
acid  solution  with  lead  peroxide,  or  oy  heating 
with  ammonium  persulphate  in  the  presence  m 
a  little  silver  nitrate  (Chem.  News,  1901,  84, 
239). 

Manganese  in  Ferromanganese  and  Steels.  The 
foregoing  methods  a,  b,  and  c  (L)  have  all  been 
employed  for  this  purpose;  method  e  (L)  is  the 
simplest  and  probably  the  most  accurate.  In 
method  a  it  is  necessary  to  remove  iron  from 
the  solution ;  this  is  conveniently  performed  by 
adding  a  slisht  excess  of  zinc  oxide  to  the 
solution  {v.  references  given  above ;  also  J.  Amer. 
Chem.  Soc.  1902, 24, 243 ;  Ann.  Ctnm.  anal.  1906, 
11,  124). 

Manganese  and  Chromium  occurring  together 
in  steels  may  be  estimated  by  oxidising  with 
ammonium  persulphate  in  sulphuric  acia  solu- 
tion in  the  presence  of  silver  nitrate ;  one 
portion  of  solution  is  titrated  for  total  perman- 
ganate  and  chromate  with  ferrous  sulphate,  and 
another  for  permanganate  alone  by  means  of 
arsenious  oxide  (J.  Amer.  Chem.  Soc.  1905,  27, 
1560;  V.  also  Chem.  News,  1901,83,25;  1905, 
91,  3 ;  Chem.  Zeit.  1906,  29,  987 ;  Chem.  Zeit. 
Rep.  1906,  29,  380). 

The  foregoiug  bismuthate  method  e  (L)  may 
be  applied  in  the  presence  of  molybdenumf  tunf' 
sten,  tttanium,  and  vanadium ;  also,  with  certam 
precautions,  in  the  presence  of  chromium  (Chem. 
I  KewB,  1901,  84, 247).  (For  estimating  WMngansse 
in  tungsten  steels,  v.  also  J.  Soc.  Chem.  Ind.  1907* 
26,  346.) 

Mereory.  (a)  By  precipitation.  Mercuric  ni- 
trate is  readily  titrated  with  ^/10-thiocyanate^ 
using  ferric  nitrate  as  indicator,  provided  that 
nitric  acid  is  present  in  fairly  nigh  concen- 
tration (Ber.  1901,  34,  3602 ;  1902,  36,  2015). 
Chloride  must  be  absent;  if  necessary,  the 
mercury  is  precipitated  as  oxide  with  sodium 


ANALYSIS. 


iid 


hydroxide,  and  the  washed  precipitate  dissolved  | 
in  nitric  acid. 

(6)  JodimetricaUff.  The  mercurio  solution 
(25-^50  0.0.)  containing  1  gram  of  potaasium 
iodide  is  made  alkaline  with  sodium  hydroxide, 
2-3  c.a  of  40  p.c.  formaldehyde  added,  and  the 
whole  shaken  vi^orousl^  for  two  minutes.  The 
solution  is  acidified  with  acetic  acid,  and  the 
reduced  mercury  is  dissolved  by  adding  an 
excess  of  A^/10-iodine.  After  shaking,  the  excess 
of  iodine  aoove  that  required  to  form  mercuric 
iodide  is  titrated  with  V/10-thiosulphate  (Ber. 
1906,  39,  3702;  1907,  40,  3276;  Bull  Soa 
ohim.  1907,  [iv.]  1,  1169).  Mercurous  salts 
require  a  preliminary  oxidation. 

(For  other  methods,  v.  Compt.  rend.  1863, 
56,  63;  Chem^  Soo.  Trans.  1892,  61,  364; 
Arch.  Pharm.  241,  444.) 

HolybdeniiOL  (a)  By  reduction  and  «ii5«e- 
fuetU  oxidation.  The  sulphuric  acid  solution 
18  reduced  by  passing  it  throush  a  long  column 
of  amalgamatea  sine  to  a  con£tioD  represented 
b^  the  formula  Mo,0|;  the  liquid  is  caught 
directly  in  ferric  sulphate  solution,  which  re* 
oxidises  the  molybdenum  salt,  and  the  ferrous 
sulphate  produoea  is  titrated  with  ^/10-perman- 
ganate  (Amer.  J.  Sci.  1907,  24,  313 ;  compare 
Ber.  1905,  38,  604 ;  Analyst,  1907,  32,  250). 

(6)  lodimdrioaUy.  The  solution  in  concen- 
trated hydrochloric  acid  is  boiled  with  a  slight 
excess  of  potaasium  iodide  till  the  volume  is 
reduced  to  25  cc,  when  complete  reduction  to 
the  condition  Mo^Of  is  effected.  The  solution 
is  cooled,  diluted  to  125  cc,  0*5  gram  of  man- 
ganese sulphate  added,  and  then  a  slight  excess 
of  ^/10-perman^nate ;  ^/lO-arsenious  acid 
is  next  added,  imd  after  the  addition  of  tartaric 
acid  and  sodium  bicarbonate,  the  excess  is 
titrated  with  i\^/10-iodine.  The  permanganate 
ptus  iodine  and  minus  the  arsenious  acid  measure 
the  Mo,0.  present  (Amer.  J.  Sci.  1901,  12,  449 ; 
compare  Qi%d,  1896,  2,  156 ;   1898,  6,  168). 

moiybdenum  in  Steels  and  AUoys{v,  J.  Amer. 
Caiem.  Soc.  1904,  26,  675). 

HlekeL  (a)  By  double  cyanide  formation,  A 
few  drops  of  10  p.c.  potassium  iodide  are  added 
to  the  cold,  slightly  ammoniacal  nickel  solution, 
snd  then  a  small  measured  volume  of  silver 
nitrate  (3  grams  of  silver  per  litre).  Standard 
potassium  cyanide  (25  grams  per  litre)  is  then 
run  in  with  stirring  till  the  precipitate  of  silver 
iodide  just  disappears ;  more  silver  nitrate  is 
lAlded  till  a  very  faint  turbidity  is  produced, 
which  is  then  dissolved  by  the  least  possible 
excess  of  cyanide.  The  relative  values  of  the 
silver  nitrate  and  cyanide  solutions  are  deter- 
mined by  a  preliminary  experiment,  and  the 
cyanide  standardised  against  a  known  amount 
of  pure  nickel  (or  pure  silver,  and  calculated  to 
nicicel).  The  metnod  is  rapid  and  accurate 
(Caiem.  News,  1895,  72,  92). 

(&)  By  precipitation.  The  hot  nickel  solu- 
tion containing  ferric  chloride  and  citric  acid 
is  made  feebly  ammoniacal  and  titrated  slowly, 
stirring  constantly,  with  standard  potassium 
ferrocyanide  (20  grams  per  litre,  titrated  against 
pure  nickel),  untu  a  drop  of  the  solution  when 
acidified  with  dilute  acetic  acid  develops  a  green 
colour  in  five  minutes  (J.  Amer.  Chem.  Soc.  1910, 
32,  757  ;  Bull  Soc.  chim.  1907,  4,  1163). 

Nickel  in  Sted.  Method  (h)  can  be  directly 
applied  ;  method  (a)  can  also  be  employed  with- 


out removing  iron,  molybdenum,  or  chromium, 
if  a  sufficient  excess  of  ammonium  citrate  or 
sodium  pyrophosphate  is  added  to  the  solution  ; 
or  a  moderate  amount  (2-3  grams)  of  each 
of  these  reagents  may  be  aoded  (J.  Amer. 
Chem.  Soo.  1907,29, 1201 ;  1908,30, 1116;  1899, 
21,  854;  Chem.  Zeit.  1908,  32,  1223).  (For 
modifications  in  preeenoe  of  other  metals, 
V.  Chem.  News,  1898,  78, 177,  190.) 

Nitrogen.  Ammonia  (v.  AomnfSTRY  and 
Alkalimktby). 

HTDBAzma.  lodimetricaUy,  A  moderate 
excess  of  sodium  bicarbonate  or  sodium  acetate  is 
added  to  the  solution  of  a  hydrazine  salt,  which 
ia  then  titrated  with  ^/10-iodine.  N|H4=21 
(J.  pr.  Chem.  1902,  66,  332 ;  1903,  67,  140 ; 
V,  also  Gazz.  ohim.  ital.  1899,  29,  265). 

Hydkoxylamikb.  (a)  By  oxidation.  The 
solution  of  a  hydroxyUmine  salt  is  slowly  added 
to  excess  of  boiling  and  well-stined  Barreswirs 
(Fehling's)  solution,  the  precipitated  cuprous 
oxide  washed,  dissolved  m  acid  ferric  alum, 
and  the  ferrous  salt  titrated  with  permanganate. 
NH,OH=:Cu,  (Chem.  Soc.  Trans.  1903,  83, 
1394 :  compare  Ber.  1877,  10,  1940). 

(6)  By  reduction.  An  excess  of  titenium 
sesqUisulphate  is  added  to  the  acid  solution, 
and  the  ammonium  salt  producod  is  estimated 
by  distillation  with  sodium  hydroxide  (Ber. 
1909,  42,  2695). 

NiTBATSS.  (a)  By  reduction.  The  solution 
is  made  strongly  alkalme  with  sodium  hydroxide, 
5  cc  of  alcohol  and  2*5-^  grams  of  powdered 
Devarda's  alloy  added,  and  the  flask  connected 
with  a  distilling  apparatus,  the  receiver  of  which 
contains  excess  of  Ar/2 -hydrochloric  acid.  After 
stendinff  for  half  an  hour,  the  liquid  is  steam - 
distilled  for  an  equal  length  of  time,  when  all 
the  nitrate  has  been  converted  into  ammonia 
and  driven  over  into  the  acid  ;  the  excess  of  the 
latter  is  then  titrated  (Zeitsch.  anal.  Chem. 
1894,  33,  113;  Analyst,  1910,  35,  307;  t;.  also 
the  Oravimetric  section), 

(b)  lodimetricaUy  (v,  Zeitsch.  angew.  Chem. 
1890,  3,  477;  Chem.  Soo.  Trans.  1891,  59, 
530  ;  Amer.  J.  Sci.  1892,  44,  117). 

NiTBiTBS.  (a)  Btf  oxidation.  The  nitrite  solu- 
tion is  slowly  added  to  a  measured  quantity  of 
i^/10-permanganate,  which  ia  acidified  with  sul- 
phuric acid,  diluted  to  400  cc,  and  warmed  to 
40®,  until  the  colour  is  just  discharged. 
2HN0a  B-  0,.  Otherwise,  the  cold  dilute  nitrite 
solution  is  slowly  titrated  with  ^/10-permanga- 
nato  to  a  red  colouration;  a  few  drops  of  sul- 
phuric acid  are  then  added,  followed  by  an  excess 
of  permanganate.  The  liquid  is  then  strongly 
acidified  with  sulphuric  acid,  heated  nearly  to 
boiling,  and  the  excess  of  permanganate  titrated 
with^/10-oxalic  acid  (Amer.  Chem.  J.  1883,  5, 

388). 

(6)  lodimetricaUy,  Several  methods  have 
been  based  on  the  reaction. 

2HH-2HNO,  -  I,+2N04-2H,0. 
It  is  necessary  to  perform  the  experiment  in  an 
atmosphere  free  from  oxygen ;  tne  iodine  may 
be  determined  by  thiosulphate  or  arsenite.  (For 
details,  v.  Pharm.  J.  19,  741 ;  Chem.  News, 
1904,  90,  114;  cf.  Organic  analysis;  Aromatic 
amines.) 

ColorimetricaUy.  Nitrous  acid  may  be  esti- 
mated by  the  formation  of  a  yellow  colour  due 
to  the  production  of  paranitrosodimethylaniline. 


270 


ANALYSTS. 


previously  dipped  in  the  titrating  flask,  is 
brought  into  contact  with  a  drop  of  the  ferrl- 
cyanide.  Ab  lon^  as  any  ferrous  salt  remains  a 
blue  precipitate  is  produced ;  the  approach  of 
the  end  is  indicated  by  the  decrease  in  intensity 
-of  the  blue  colouration,  and  when  very  near 
the  end  about  thirty  seconds  should  be  allowed 
for  the  colour  to  develop.  The  end-point  is 
reached  when  the  blue  colour  ceases  to  appear. 
The  ferricyanide  solution  should  be  prepared 
only  when  required  by  dissolving  in  water  a 
crystal  of  the  salt  which  has  been  rii^ed  to  remove 
superficial  ferrocyanide :  the  yellow  colour  of 
the  drops  on  the  white  plate  should  be  barely 
visible ;  if  the  ferrioyaniae  is  too  concentrated, 
the  blue  colouration  changes  through  various 
shades  of  green  into  a  brown  tint. 

lodiTie,  Sodium  thiosnlphate,  and  Sodium  arseniie, 

Deoinormal  solutions  of  these  reagents  are 
frequently  used  in  conjunction  with  one  another. 
The  reaction  between  iodine  and  sodium  thio- 
sulphate  is  essentially : 

2Na,SjO,+I,  =  Na^40,+2NaI 

althoush  under  certain  circumstances  oxidation 
to  sulphate  proceeds  to  a  small  extent,  even  at 
the  ordinary  temperature  (Pickering).  When 
usin^  decinormal  solutions  the  end-point  is 
readily  indicated  by  the  appearance  or  disr 
appearance  of  the  yellow  colour  of  the  iodine, 
provided  the  solution  undergoing  titration  is 
not  unduly  diluted  and  is  otherwise  colourless. 
The  production  of  a  blue  colour  when  free 
iodine  and  starch  solution  are  brought  toother 
is,  however,  much  more  sensitive,  and  is  the 
method  usually  employed  in  ascertaining  the 
end-point. 

Prtparaiion  of  starch  schUion. — About  1  gram 
of  powdered  starch  is  rubbed  into  a  paste  with 
a  httle  cold  water,  and  slowly  added  to  200  c.c  of 
boiling  water,  the  boiling  is  continued  for  two 
or  three  minutes,  the  solution  cooled,  and  after 
some  hours  the  dear  liquid  is  decanted.  The 
solution  will  only  keep  for  one  or  two  days, 
unless  sterilised,  when  it  is  conveniently  pre- 
served in  small  bottles,  completely  filled  and 
closed  by  soft  rubber  stoppers;  it  will  then 
keep  indefinitely.  Starch  paste  prepared  from 
Oastine's  formiUA  (5  srams  starch,  0-01  gram 
merourio  iodide^  and  1  litre  water)  retains  its 
soQsitiveness  for  a  long  time.  Addition  of  1  c.o, 
of  oil  of  cassia  to  a  litre  of  starch  liquoi  is  also 
recommended  as  a  preservative. 

Sensitiveness  of  the  iodin&^tarch  reaction, — 
This  depends  upon  several  oiroumstanoes.  It 
is  necessary  to  work  with  cold  solutions,  pre- 
ferably neutral  or  slightly  aoid;  the  presence 
of  mineral  aoid  in  high  oonoentration  greatly 
impairs  the  sensitiveness  of  the  reaction,  since 
it  hydrolases  the  starch.  It  is  essential  that 
a  soluble  iodide  should  be  present  (usually  this 
is  potassium  iodide)  in  moderate  amount;  the 
best  concentration  of  potassium  iodide  to 
employ  is  about  N/160,  since  the  sensitiveness  of 
the  reaction  then  reaches  a  maximum  (see  Zeitsoh. 
anal.  Chem.  1902,  41,  486;  Amer.  J.  Sci.  1900, 
[iv.]  10,  161 ;  J.  Amer.  Chem.  Soo.  1909,  31, 
1038). 

Good  starch  solution  first  yields  a  pink 
colouration  with  iodine,  which  more  iodine 
develops  into  the  blue  colour;    starch  which 


produces  green  tints  should  be  rejected  (J.  Amer. 
Chem.  Soc.  1908,  30, 31).  It  frequently  happens 
in  titrating  arsenious  and  antimonious  oxides 
with  iodine  that  various  tints  of  red  make  their 
appearance  instead  of  the  usual  blue  coloura- 
tion. This  is  due  to  impurity  in  the  starch  :  in 
such  a  case  one  or  two  grams  of  potassium  iodide 
are  added,  the  end-point  being  ascertained  firom 
the  development  of  tne  yellow  colour  of  the  iodine* 
and  then  confirmed  by  the  starch  (Amer.  J.  Sci. 
1902,  [4]  13,  379). 

Sinnatt  (Analyst,  1910,  36,  309)  has  shown 
that  1  C.C  of  a  dilute  aqueous  solution  of 
methylene  blue  (O'Od  gram  pen.  litre)  may  be 
,  used  in  place  of  starch  as  an  indicator  in  iodi- 
metrio  titrations  (see  also  Analyst,  1912,  37» 
262). 

For  the  iodine  solution  26  grams  of  potassium 
iodide  are  dissolved  in  a  little  water,  12*7  mma 
of  commercial  iodine  added,  and  the  nuxturo 
shaken  till  the  iodine  has  dissolved ;   the  solu- 
tion   is    then    filtered    through    asbestos    and 
[diluted  to  1  litre.    It  should  be  kept  in  the 
dark,  and  protected  from  dust.     For  the  thio- 
\  sulphate  sotution  the  crystaUine  salt  Na^StOg, 
|6H|0   is   dissolved   in   distilled    water,    using 
26  grams  per  litre,  and  the  solution  kept  away 
from  direct  sunlight  for  two  weeks  before  it  is 
standardised.     It    then    retains    its    titre    for 
I  months.    For  the  sodium  arsenite,  4*948  grams  of 
,  resublimed  arsenious  oxide  are  dissolved  in  a 
.little  warm  sodium  hydroxide  free  from  iron, 
the  solution  rinsed  into  a  litre  flask,  and  made 
just  acid  to  phenolphthalein  with  dilute  sul- 
,  phurio  acid.    A  filtered  solution  of  20  srams  of 
,  sodium  bicarbonate  in  600  c.c.  of  water  is  added, 
I  and  if  the  mixture  reacts  alkaline  to  the  phenol- 
Iphthaleln,  sulphuric  acid  added  till  the  pink 
,  colour  disappears.    This  solution,  when  diluted 
to  1  litre  and  thoroughly  mixed,  is  strictly  deci- 
normal,  and   keeps  indefinitely.     A  measured 
quantity  of  the  N/iO  -arsenite  solution  is  delivered 
into  an  Erlenmeyer  flask,  and  the  iodine  solu- 
tion run  in  from  the  burette  until  present  in 
slight  excess,  starch  paste  being  adaed  nearly 
at  the  finish  of  the  titration  {see  remarks  on 
starch  above).    The  reaction 

I  A8,0,+2Is-|-2H,0  ^  A8,0s+4HI 

proceeds  to  completion  in  the  sense  of  the  upper 

arrow  in  neutral  solution,  a  condition  secured 

by   the   presence   of   the   bicarbonate,    which 

neutralises  the  hydriodio  aoid  produced.    Since 

^he  solution  should   be  saturated  with  carbon 

I  dioxide,  it  is  advisable  to  stopper  the  flask 

;  except  when  actually  introducing  the  iodino 

(J.  Amer.  Chem.  Soc  1908,  30,  31). 

The  iodine  being  standardised,  the  thio- 
snlphate can  be  directly  titrated  against  it, 
preferably  by  running  the  iodine  into  a  meaaured 
volume  of  thiosulphate. 

llany  alternative  methods  have  been  pro- 
posed ior  standardising  iodine  and  thiosulphate 
solutions.  The  latter  may  be  titrated  against 
pure  iodine :  0*6  gram  of  pure  iodine  and  0*1  gram 
of  potassium  iodide  are  powdered  and  mixed 
together  in  a  porcelain  dish,  and  heated  on  a 
sand-bath  till  vapour  is  copiously  evolved ;  the 
dish  is  then  covered  with  a  dry  watch-glass,  and 
the  greater  part  of  the  iodine  sublimed  on  to  it. 
The  watch-glass  is  covered  with  a  second  aooa- 
rately  fitting  glass  and  the  whole  weighed,  the 


ANALYSIS. 


271 


weight  of  the  glasses  having  been  previoasly 
found.  The  whole  is  gontly  placed  in  a  solution 
of  1  gram  of  potassium  iodide  in  10  o.c.  of  water, 
and  after  a  few  seconds  the  solution  is  diluted 
to  100  0.0.  and  titrated  with  the  thiosulphate. 

The  thiosulphate  may  also  be  standardised 
against  permanganate,  itself  veriBed  by  reference 
to  sodium  oxalate.  One  or  two  grams  of  notas- 
sium  iodide  are  dissolyed  in  water,  acidifiea  with 
6  ao.  of  hydroohlorio  acid  (1:6)  and  25  c.c.  of 
standard  permanganate  added.  The  iodine, 
which  is  quantitatively  liberated : 

Mn,09  +  lOHI  «  2BlnO  +  5H,0+5I. 
is  then  titrated  with  the  thiosulphate,  after 
diluting  the  solution  to  100  o.c  By  the  reverse 
process  of  oalculationy  a  permanganate  solution 
may  be  standardised  against  a  thiosulphate 
solution  that  has  been  verified  by  either  of  the 
precediag  methods  (««e  Standardisation  of  per- 
manganaU;  cf.  Annalen,  1807, 108, 333 ;  Zeitsch. 
angew.  Ghem.  1904,  17,  816 ;  Ann.  Chim.  Anal. 
1904,  9,  365;  Zeitsch.  anorg.  Ghem.  1906,  49, 

277). 

(For  the  use  of  potassium  dichromate  in  this 
connection,  Me  VolwMiric  estimation  of 
chromium:  Zeitsch.  anorg.  Ghem.  1899,  19, 
427;  1906,  49,  277.  See  also  Copper  under 
Volumetric  estimations.  For  a  ^vimetric 
metiiiod  for  standardising  iodine  solution,  consult 
Amer.  J.  Sci  1909,  (iv.)  28,  33.) 

Titanous  chloride. 

This  recent,  introduced  into  volumetric 
analysis  by  f  necht  (J.  Soc.  Dyers  and  Golourists, 
19,  No.  6;  Ber.  1907,  40,  3819),  is  a  powerful 
reduoinff  agent.  For  example,  a  hydrochloric 
aoid  solution  of  ferric  chloride  is  quickly  and 
quantitatively  reduced  in  the  cold,  accordiing  to 
the  equation : 

FeCl,  +  Tia,  =-  Fea,  +  TiQ* 
and  the  end-point  is  reached  when  a  drop  of 
the  liquid  ceases  to  produce  a  red  colouration 
with  potassium  thiocyanate.  Ghromic  acid  and 
oapno  salts  may  be  similarly  estimated,  and 
also  a  laige  num  oer  of  organic  dyes. 

Fifty  ao.  of  the  commercial  20  p.o. 
solution  of  titanous  chloride,  which  usually  con- 
tains a  little  iron,  are  mixed  with  an  equal 
volume  of  concentrated  hydrochloric  acid,  boiled 
for  several  minutes,  and  diluted  to  1  litre  with 
air-free  water.  The  solution  must  be  kept  pro- 
tected from  the  air;  a  convenient  method  is 
figured  in  Sutton's  Volumetric  Analysis  (9th  ed.), 
p.  224. 

The  concentration  of  the  solution  is  fixed 
by  titrating  against  a  known  quantity  of  either 
fcsrio  Bah  or  potassium  dicmromate.  In  the 
former  case  35  pams  of  j)ure  ferrous  ammonium 
sulnhate  are  dissolved  m  dilute  sulphuric  acid 
ana  the  solution  diluted  to  1  litre ;  25  c.c.  are 
then  exactly  oxidised  with  dilute  permanganate, 
and  the  resulting  ferric  sulphate  titrate  with 
the  titanous  chloride  until  a  drop  of  the  solution 
no  longer  gives  a  red  colour  with  potassium 
thiooyanate.  Instead  of  using  this  '  spot-out ' 
method,  10-20  0.0.  of  10  p.o.  potassium  thio- 
oyanate  may  be  added  to  the  ferric  solution. 
u  the  standardisation  be  effected  with  potas- 
siom  dichromate,  addition  of  the  indicator  to 
the  solution  itself  is  inadmissible.  Nearly  all 
the  titanous  chloride  necessary,  may,  however, 


be  added  at  once,  since  the  colour  changes, 
through  orange  to  green  and  then  violet,  afford 
an  indication  of  the  end-point.  Drops  of  solu- 
tion are  removed  for  testins  when  the  green 
colour  has  just  disappeared  (J.  Soc.  Ghem.  Ind. 

1908,  27,  673). 

Pure  ferric  alum,  the  preparation  of  which 
is  described  by  De  Koninck  (Bull.  Soc.  chim.  Belg. 

1909,  23,  222),  might  also  be  employed  for  this 
standardisation. 

For  a  number  of  estimations  it  is  necessary 
to  employ  titanous  sulphate  instead  of  the 
chloride. 

Stannous  chloride. 

This  reagent  has  long  been  employed  as  a 
reducing  agent,  but  the  closely  allied  and  more 
powerfmly  reducing  titanous  salts  appear  to  be 
displacing  it.  Ferric  salts  are  easily  reduced 
in  not  acid  solution : 

2Feaa  +  SnG,  «  SnCi^  +  2Fea,. 

Iodine  in  cold  acid  solution  oxidises  it 
quantitatively : 

2Snaa  +  21,  «  Sxd^  +  SnCi^. 

Ten  grams  of  pure  tin  in  thin  pieces  are 
heated  with  200  c.c.  of  concentrated  hydro- 
chloric acid  iu  a  platinum  dish  until  dissolved : 
or  a  glass  flask  ma^  be  used  with  a  piece  of 
platinum  foil  touching  the  tin  to  promote  its 
speedy  solution.  The  solution  is  diluted  to 
1  litre,  and  preserved  out  of  contact  with  the 
air. 

The  solution  is  best  standardised  by  that 
process  for  which  it  is  afterwards  to  be  employed, 
eg,  if  required  for  iron  estimations,  by  titration 
against  a  known  amount  of  ferric  chloride. 
The  latter  may  be  obtained  by  dissolving 
10*03  CTams  of  bright  iron  wire  (99*7  p.c  iron) 
in  hycurochloric  acid,  oxidising  with  potassium 
chlorate,  expelling  the  excess  of  chlorine  by 
boiling,  and  diluting  the  solution  to  1  litre; 
25  C.C.  are  conveniently  used  for  titrating  the 
above  solution. 

Several  methods  have  been  proposed  for 
determining  the  end-point.  The  iron  solution 
containing  20-40  c.c.  of  concentrated  hydro- 
chloric acid  in  a  volume  of  126  c.c.  may  be 
titrated  nearly  at  the  boiliag-point,  15  0.0.  of 
indicator  solution  (34  grams  ligGls+0'05  gram 
Pt  as  chloride  per  litre)  being  added.  The 
end-point  is  reached  when  a  dark'Cloud  of 
finely  divided  mercury  and  platinum  is  pro- 
duced (Amer.  Ghem.  J.  1893,  15,  360).  Or  a 
drop  of  the  solution  may  be  mixed  with  am- 
monium molybdate  on  a  white  plate;  the 
slightest  trace  of  stannous  salt  causes  a  blue 
c^uration.  An  alternative  is  to  add  a  slight 
excess  of  stannous  chloride,  and  titrate  back 
the  cold  solution  with  iodine. 

(For  the  standardisation  by  means  of  iodine, 
see  Volumetric  estimation  of  tin.) 

Silver  nitrate^  Sodium  chloride,  and  Am- 
monium thiocyanate. 

These  precipitation  reagents,  which  are  con- 
veniently made  of  decinormal  stren^h,  are  of 
great  service  for  the  volumetric  estimation  of 
silver,  copper,  mercury,  the  halogen  acids, 
cyanides,  and  thiocyanates. 

Silver  nitrate  is  used  either  in  neutral  or  in 
nitric  acid  solution.    In  the  first  case  potassium 


282 


ANALYSIS. 


TttantmiL  By  reduction  and  svhsequtnl 
oxidalion.  It  is  difficult  to  obtain  aocuiate 
results  with  quantities  of  titanium  dioxide 
exceeding  0*15  ^m.  The  warm,  dilute  sul- 
phuric aoid  solution  of  titanic  salt  is  reduced  to 
the  teryalent  condition  by  means  of  zinc, 
aluminium-magnesium  alloy,  or  zinc-aluminium 
alloy  (Zn,  90  p.c.  Al  10  p.c,  cast  in  sticks), 
cooled  and  rapidly  filtered  into  ferric  sulphate 
solution ;  Has  equivalent  quantity  of  ferrous 
sulphate  produced  is  titrated  with  ^/10-perman- 
ganate.  Ti  «  Fe  (Chem.  Zeit.  1907,  31,  399 ; 
Amer.  J.  SoL  1908,  25,  130 ;  Analyst,  1910,  35, 
198;  oompare  J.  Amer.  Chem.  Soo.  1895,  17, 
878). 

'  Tiianium  and  Iran  (v.  Iron). 

Tangsten.  By  reduction  and  subsequent 
oxidation.  The  solution  is  reduced  by  zinc  and 
hydrochloric  acid  to  a  condition  corresponding 
to  the  oxide  WO.,  filtered  and  titrated  with  a 
standard  ferric  solution.  The  end-point  is  per- 
ceived W  the  disappearance  of  the  intense  blue 
colour  of  the  intermediate  compound  correspond- 
ing to  W,0|,  the  reaction 

Fe,0,4- WOj  =  WO,+2FeO 

being  quantitative  (Chem.  Soc.  Proo.  1909,  25, 
227). 

Uranium,  (a)  By  reduction  and  svbsequent 
oxidation.  The  solution,  containing  20  c.c.  of 
concentrated  sulphuric  acid  in  a  volume  of 
125  c.c,  is  pouriad  upon  100  grams  of  pure 
zino  (in  sticks  2  oul  Ions),  heated  nearly  to 
boiling  for  15  minutes,  nltered  into  a  htrse 
porcelain  dish,  and  the  zino  washed  with  cold 
dilute  sulphuric  acid  (1  :  10  by  volume)  till  the 
total  volume  of  solution  is  300  cc  The  solution 
of  uranous  sulphate,  which  should  be  aeA-frnen  in 
colour,  is  then  titrated  with  i\r/10-permanganate. 
Hie  solution  can  also  be  reduced  by  passage 
throuffh  a  long  column  of  amalgamated  zinc ; 
in  either  case  the  reduction  proceeds  a  little 
too  far,  but  oxidation  to  the  uranous  state  is 
accomplished  during  the  filtration  and  washing. 
High  results  are  obtained  by  carrying  out  the 
experiment  in  an  atmosphere  of  carbon  dioxide. 

5U(S04),  =  2KMn04  =  lOFeSO^,  or  U  =  2Fe 

(J.  Amer.  CheuL  Soc.,  1909,  31,  367 ;  compare 
ibid.  1901,  23,  085 ;  1906,  28,  1541 ;  Amer.  J. 
Scl  1903,  16,  229). . 

(6)  lodimetrieally  (v.  Ber.  1904,  37,  189). 

Uranium  and  Vanadium  {v.  J.  Amer.  Uiem. 
Soc.  1906,  28,  1443). 

VuuuUnm.  (a)  By  reduction  and  subsequent 
oxidation.  (L)  The  vanadic  solution  containing 
sulphuric  acid  is  boiled  with  sulphur  dioxide 
until  the  colour  is  a  pure  blue,  and  the  excess 
of  sulphur  dioxide  then  expelled  with  carbon 
dioxide ;  tiie  solution,  containing  vanadium 
salt  correspondinff  to  the  oxide  VsOa,  is  then 
titrated  hot  with  ^/10-permanganate.  (ii.)  The 
sulphuric  acid  solution  is  passed  through  a  long 
column  of  amalgamated  zinc,  and  the  reducea 
solution  collected  and  titrated  as  described 
under  Molybdenum.  In  this  case  reduction 
proceeds  as  far  as  the  oxide  V^O-j  (Amer.  J. 
Sol.  1908,  25,  332;  compare  ibid.  1903, 
15,  389).  (iii.)  The  solution  is  evaporated 
nearly  to  dryness  three  times  with  concentrated 
hydrochloric  acid,  when  vanadvl  chloride  VOd, 
is  farmed;  hydrochloric  acid  is  removed  by 
•vaporatioci  nith  sulphuric  acid,  the  solution 


diluted  and  titrated  with  ^/10-permanganate 
(Ber.  1903,  36,  3164). 

(6)  By  reduction*  The  vanadate  solutiont 
hot  or  cold,  and  containing  hydrochloric  or 
sulphuric  acid,  is  titrated  with  standard  (2  p.c.) 
stannous  chloride  (titrated  against  iodine)  until 
a  drop  of  the  solution  ffives  a  blue  colouration 
with  ammonium  molyodate.  Reduction  pro- 
ceeds as  far  as  the  tetroxide  VtO^  (BulL  Soc. 
chim.  1908,  3,  626). 

(e)  lodimetricaUy.  (L)  About  0-3-0-5  gram 
of  vanadate  is  distilled  with  1*5-2-0  grams  of 
potassium  bromide  and  30  cc.  of  concentrated 
hydroohlcMrio  acid,  the  liberated  bromine  ab- 
sorbed in  potassium  iodide,  and  the  iodine 
titrated  with  ^/lO-thiosulphate ;  Yfi^  »  Br„ 
the  reduction  proceeding  to  the  tetroxide  (Chem. 
Zentr.  1890,  i.  977 ;  for  other  iodimetrio  methods^ 
V.  Amer.  J.  Sci.  1896,  2,  185,  355;  1902,  14, 
369). 

Vanadium  and  Chromium  {v.  BulL  Soc  ohim. 
1904,  31,  962). 

Vanadium  and  I7rafit«ffi  {v.  J.  Amer.  CSiem. 
Soc.  1906,  28,  1443). 

Vanadium  and  iron  (v.  Iron;  and  J.  Amei. 
Chem.  Soc.  1908,  30,  1229,  1233). 

Zine.  (a)  By  precipitation.  The  chloride 
solution,  containing  3  cc.  of  concenteated  hydro- 
chloric acid  in  a  volume  of  250  cc,  is  heated 
nearly  to  boiling,  and  titrated  with  standard 
potassium  ferrocyanide  solution  (21-5  mma 
per  litre,  titrated  against  pure  zinc)  uniu  one 
or  two  drops  of  the  solution  j»roduce  a  brown 
colouration  with  uranium  mtrate  (J.  Amer. 
Chem.  Soc  1900,  22,  198 ;  1904,  26,  4 ;  1908, 
30,  225;  Zeitsch.  anal.  Chem.  1906,  44,  174). 
The  uranium  nitrate  indicator  may  be  replaced 
by  ammonium  molybdate  (Chem.  2eit.  1905,  29, 
951).  It  has  been  recommended  to  add  exoees 
of  ferrocyanide,  and  titrate  back  with  standard 
zino  chloride  (Zeitsch.  anaL  Chem.  1896,  35, 
460). 

(For  the  application  of  this  method  to  ores 
and  alloys,  v.  J.  Amer.  Chem.  Soc.  1907,  29, 
265 ;  Chem.  Zeit.  1905,  29,  951 ;  J.  Soc.  Chem. 
Ind.  1905,  24,  228,  1278.) 

(b)  Acidimetrically.  As  for  Magnesium^  v. 
supra,  p.  212 ;  and  J.  Amer.  Chem.  Soc  1901, 
23,468. 

(c)  lodimeiricaUy.  As  for  Magnesium,  v. 
supra,  p.  212 ;  and  J.  Amer.  Chem.  Soc  1900, 
22,353. 

COLOBDfSTmiO  MlTHODS. 

These  methods  are  especially  vaJuaole  for 
the  estimation  of  very  small  <)uantitie8  of  sab- 
stances,  and  are  capable  of  givmff  very  accurate 
results.  The  depth  of  tint  proauoed  by  some 
characteristic  colour  reagent  m  a  given  volume 
of  the  solution  is  compared  with  the  tint  pro- 
duced by  the  same  reagent  in  an  equal  volame 
of  a  solution  containing  a  known  quantity  of 
the  substance  to  be  determined.  The  tint  in 
the  comparison  tube  can  be  varied  by  varying  the 
proportion  of  the  substance  which  it  contains, 
ana  when  the  tints  are  equal  the  quantities  d 
the  substance  in  each  tube  are  also  equaL  The 
quantity  in  one  tube  is  known,  and  hence  that 
in  the  other  is  determined.  It  is  important  that 
the  comparison  be  made  nnder  comparable  ooo- 
ditions  with  respect  to  degree  of  aoidiW  or 
alkalinity,  proportion  of  the  xesfenti  and  tlM 


ANALYSIS. 


283 


like.  It  is  also  important  that  the  depth  of  tint 
should  not  be  materially  affected  by  the  presence 
of  other  saline  substances  in  the  solution  under 
examination. 

The  following  substances  may  be  determined 
by  these  methods  : — 

Lndy  with  hydrogen  sulphide. 

Copper,  with  hydrogen  sulphide  or  potassium 
fenocyanide  (Gamelley,  Chem.  News,  32»  308). 

iron,  with  potassium  feirocyanide  (Carnelley, 
Chem.  News,  30»  257). 

Iroil,  with  potassium  thiocyanate  (Thomson, 
Chem.  Soc.  Trans.  1885,  493). 

Vanadium,  with  hydrogen  peroxide. 

Tltaniuin,  with  hydrogen  peroxide  (Weller, 
Ber.  1882,  15,  2593). 

Ammonia,  by  Nessler's  solution  {v.  Watsb). 

Iodine,  in  solution  in  carbon  disulphide,  or 
with  starch. 

Nttrates,  by  phenolsulphonic  acid  test 
(v.  Watxb). 

Nitlttei,  by  (i)  m-phenylenediamine ;  (ii.) 
sulphanilio  acid  and  a-naphthylamine  {v.  Water). 

The  principle  may  likewise  be  applied  to  the 
comparison  of  colouring  matters,  provided  that 
the  solutions  are  sufficiently  dilut^  (v.  Colobi- 
kstsb). 

Ultdults  Analysis  ov  Gabbon  Compoukds. 

The  majority  of  carbon  compounds  contain 
carbon,  hydrogen,  and  oxygen,  or  carbon,  hydro- 
gen, oxygen,  and  nitrogen ;  a  smaller  number 
contain  one  or  more  of  the  halogens,  or 
sulphur.  There  are  a  still  smaller  number  of 
organic  derivatives  of  phosphorus,  arsenic, 
antimony,  silicon,  and  other  metalloidal  and 
metallic  elements,  and  the  metals  also  occur  in 
the  salts  of  organic  acids. 

Qtudiiaiive  Bxamination, 

Carbon  is  converted  into  carbon  dioxide 
when  the  substance  is  heated  with  cupric  oxide. 

Hydrogen.  The  substance  is  heated  to  a 
temperature  below  that  at  which  decomposition 
begins,  until  all  water  existing  as  such  is  ex- 
pelled, and  is  then  heated  with  finely  divided 
and  recently  ignited  cupric  oxide ;  the  h;  drogen 
is  evolved  as  water. 

Mttiogen.  Many  carbon  compounds  contain- 
ing nitrogen  evolve  this  element  in  the  form  of 
ammonia  when  heated  with  caustic  soda  or  soda- 
lime,  but  this  test  is  not  ajpplicable  to  nitro-, 
nitroso-,  azo-,  and  diazo-  denvatives. 

Many  nitro-,  nitroso-,  and  diazo-  derivatives 
evolve  oxides  of  nitrogen,  with  or  without  ex- 
plosion, when  heated. 

Nitrogen  in  all  classes  of  carbon  compounds, 
with  the  exception  of  the  diazo-  compounds, 
may  be  detected  by  heating  the  substance  with 
metaJlio  sodium  or  potassium,  together  with 
some  sodium  carbonate  if  the  substance  is 
explosive.  The  nitrogen  is  converted  into 
Alkali  cyanide,  and  the  cooled  mass  ia  extracted 
with  water  and  the  cyanogen  detected  by  the 
Prussian-blue  test,  which  consists  in  adding 
ferrous  sulphate  to  the  alkaline  solution  after 
filtration,  warming  gently  and  then  acidifying, 
liitrogenous  carSon  compounds  contaming 
sulphur  yield,  when  heated  with  sodium,  a 
thiocyanate,  and  the  Prussian-blue  test  cannot 
be  used.  A  large  excess  of  potassium  is  recom- 
mended in  this  case,  when  it  is  stated  that  sulphur 


docs  not  interfere  (Tauber,  Ber.  1899,  32,  3160). 
A  mixture  of  potassium  carbonate  (138  parts) 
and  magnesium  powder  (72  parts)  has  been  re- 
commended for  genera]  use  in  detcKsting  nitrosen 
even  in  the  case  of  diazo-  derivatives  and  staole 
pyrrole  compounds  (v.  Ber.  1902,  35,  2523 ; 
Gazz.  chim.  ital.  1904,  U,  [2]  359).  This 
mixture  is,  however,  found  to  take  up  nitrogen 
from  the  atmosphere  (EUiSyChem.  News,  1910, 
102,  187). 

Halogens  are  detected  by  heating  the  sub- 
stance with  pure  lime  or  pure  soda-lime,  extract- 
ing with  water,  slightly  acidifying  with  nitric 
acid,  and  testing  with  silver  nitrate.  Highly 
nitrogenous  compounds,  when  heated  with  lime, 
are  apt  to  yield  calcium  cvanide ;  hence  the 
supposed  precipitate  of  silver  halide  should 
always  be  tested  for  cyanide  (v.  Separation 
of  cyanide  and  chloride),  unless  nitrogen  is 
known  to  be  absent.  With  soda-lime  no 
cyanide  is  formed.  The  substance  may  also  be 
heated  with  sodium  or  potassium  as  in  testing 
for  nitrogen ;  iodine  and  bromine  are  detected 
by  acidifying,  adding  chlorine  water,  and  shaking 
up  with  chloroform,  which  becomes  purple  or 
brown.  The  supposed  silver  chloride  should, 
however,  always  be  tested  for  cyanide. 

Sulphur  and  phosphorus  in  non- volatile  sub- 
stances are  detected  by  fusing  with  caustic  soda 
or  potash  mixed  with  about  one-fifth  its  weight 
of  potassium  nitrate,  or  by  heating  with  sodium 
peroxide  diluted  with  sodium  carbonate ;  in 
either  case  the  product  is  tested  for  sulphuric 
or  phosphoric  acid.  Volatile  or  non- volatile 
substances  may  be  oxidised  by  heating  in  a 
sealed  tube  at  150*-300^  according  to  cir- 
cumstances, with  fuming  nitric  acid  of  sp.gr.  1*5. 
Sulphur  and  phosphorus  are  oxidisedT  to  sul- 
phuric and  phosphoric  acid  respectively. 

Sulphur  is  also  detected  by  heating  the  sub- 
stance with  sodium,  extracting  with  water,  and 
adding  sodium  nitroprusside,  when  a  brilliant 
violet  colouration  indicates  the  presence  of 
alkaline  sulphide. 

Arsenie  and  antimony  are  detected  by  fusing 
the  substance  with  equal  weights  of  sodium 
carbonate  and  sodium  peroxide,  extracting  with 
water,  acidifying,  and  passing  in  hydrogen  sul- 
phide. Other  appropriate  t^ts  for  these  two 
elements  may  be  applied. 

Quaniitaiive  Determinations, 

Carbon  and  hydrogen  in  absence  of  nitrogen, 
lialogens,  &c. 

The  simplest  and  most  convenient  method 
for  general  purposes  is  to  bum  the  compound  in 
a  g£iss  tube  in  a  current  of  oxygen,  assisted  by 
cupric  oxide  ;  the  carbon  is  converted  into  car- 
bon dioxide,  which  is  absorbed  by  caustic 
potash ;  the  hydrogen  is  converted  into  water, 
which  is  absorbed  oy  calcium  chloride  or  con- 
centrated sulphuric  acid. 

Erlenmever's  modification  of  Von  Babo's 
furnace  is  frequently  employed.  The  heat  is 
supplied  by  a  row  of  20-25  Bunsen  burners, 
each  of  wmch  is. provided  with  a  tap  and  a  per- 
forated collar  for  regulating  the  supply  of  air. 
The  flames  strike  the  under  side  of  a  semicircular 
fireclay  or  sheet-iron  trough  or  gutter  in  which 
the  combustion  tube  rests  on  a  layer  of  magnesia 
or  asbestos.  Inclined  at  an  ansle  over  this 
gutter  on  either  side  is  a  row  of  fireclay  tiles 


SS4 

by  which  the  flame  is  TSTcrberated  upon  the 
upper  part  of  the  gliwt  tube,  which  ia  thus 
heated  oil  ruund.  Each  tile  can  be  pulled  baok 
and  rested  agaimt  on  iron  rail  irhich  rum  down 
each  aide  of  the  furnace,  and  thos  any  put  of 
the  tube  can  be  rsAdily  examined,  aad  moie- 

the  teraperatnie. 

In  Hofmann'e  fumaoe  the  tube  ia  heat«d  by 
two  doable  rowB  of  perforated  o^liadrioal  file- 
el»y  bnmera  placed  over  ordmary  fith-tail 
burneTB.  The  tube  rests  upon  the  top  of  a 
central  row  of  much  shorter  bnmers.  The 
btunera  are  indoaed  by  flat  vertical  tiles,  and 
flat  tiles  are  laid  horizontally  on  the  top. 

In  the  Qlaser  furnaoe  the  heat  is  provided  by 
a  row  of  BuDsen  borners.    The  tube  ts  supported 


tabe,  so  that  the 
and  sides  as  welt  as  from  the  bottom.  The  tube 
ia  usually  wrapped  round  with  wire  gauie.  This 
furmwe  will  give  higher  temperatnree  than  the 
Erlenmeyer  furnace,  but  consumes  more  ess. 

A  more  modem  type  of  combustion  mmace 
which  givee  very  high  temperatnree  with  a  small 
oon^umption  of  gaa  has  been  introduced  by 
Fletcher.  The  fumaoe  itself  consists  of  six  se- 
parate hallow  fireclay  bloctca  S  inches  in  length 
and  of  the  same  height,  which  are  plaoed  end 
U)  end,  so  as  to  give  a  total  length  of  3  feet. 
Hie  oombnstion  tube  is  supported  on  a  fireclay 
troiub  placed  along  the  top  of  the  row  of  fnmaoe 
blocks  which  are  each  pierced  along  one  side 
with  five  holes  leading  to  a  hollow  space  im- 
mediately below  the  trough.  The  main  gas- 
supply  pipe  is  a  brass  tube  of  sqoare  section 
which  is  raised  about  1^  inch  above  the  stone 


--«y";^ 


bench  by  ttonuinal  bntas  snpporis ;  it  oairiee 
thirty  bunien  projecting  at  right  anglea  from 
it  in  a  slanting  direction,  so  that  the&  noule« 
reach  upwards  to  the  perforations  in  the  fomaoe 
blocks,  the  oantrea  of  these  holea  being  about 
3^  inches  above  the  bench.  Each  fumace  block 
is  therefore  heated  by  five  burners,  and  rever- 
beration is  ensured  by  small  semicircular  fire- 
clay arches,  three  of  which  fit  loosely  on  each 
of  the  fnmaoe  blocks.     Owing  to  their  oblique 

Ction,  the  bnmers  are  readQy  kept  clean,  the 
»  heating  arrangement  is  quite  sepaiate 
from  the  eaiwie&ware  fomace,  and  the  taps  and 
lower  parte  of  the  bumera  are  protected  from 
tbe  heat  of  the  furnace  by  a  brass  shield  mnning 
along  the  whole  length  of  the  main  gas  pipe. 


The  fumaoe  can  be  built  up  in  sbortar  Isagth* 
by  using  fewer  of  the  fumaoe  blocks,  of  which 

two  are  represented  in  Fig.  IS. 

To  avoid  the  necessity  for  using  an  india- 

mbbtr  stopper  between  the  oombustioa  tube 

Harek 


and    the    wat«r-absor^tion    apparatus.  Hi 
suggests  a  meronry  iomt  made  by  drawing 
the   combustion   tube   to   a   oorucal   end, 
fixing  round  this  a   knee  tube   by   means  of 
asbe^oe  and  fused  silver  chloride.     The  knee 

£'  >iat,  which  is  loosely  filled  with  silvra  ribbon, 
te  into  a  bell-ahaped  tube  dippiuir  nndn 
mercury  (J.  pr.  Oiem.  1«07,  [2]  76,  IBO). 

The  combustion  tube  skcmld  eonaist  of  in- 
fusible potash  or  B<Aemian  glass  I-O-S  nun. 
thick,  with  an  internal  diameter  of  11~10  nun. 
It  should  be  of  such  a  length  that  it  proieots 
about  2  cm.  from  each  end  of  the  gutter  or 
troush.  Pieces  of  oopper  wire  gauze  alrant  2  on. 
broaid,  heated  in  a  flame  to  remove  grease,  am 
rolled  up  into  plugs  wluoh  fit  moderately  tightly 
in  the  tube,  and  one  of  these  fdugs  ia  pushed 
into  the  ttibe  to  a  dislanoe  of  about  20  om.  from 
one  end.  The  tube  is  then  filled  with  freehly 
ignited  granular  ouprio  oxide  to  within  6  or  6  am. 
of  the  other  end,  and  a  second  pluz  is  inarated. 
The  gianolea  of  onprio  oxide  shoiDd  be  fairly 
r^uLu  in  size,  and  1-6-2  mm.  cube.  Another 
plug  about  10  cm.  long  is  made  by  rolling  a  piece 
of  copper  gause  rounda  stout  coppec  wire  12  cm. 
long,  and  bending  the  projectmg  cod  of  the 
latter  into  a  loop  t>y  means  of  which  it  oan  be 
withdrawn  from  the  tube.  This  plug  is  plaoed 
in  the  other  end  of  the  tube  t«hmd  tiie  boat. 
The  end  of  the  tube  nearest  to  the  oopper  oxkb 
is  fitted  with  a  dry  oaoutohouc  stopper  perforated 
to  reoeive  the  tube  of  the  absorption  apparatos  i 
the  other  end  is  closed  by  a  aimilkr  stopper,  whioh 


the  oxygen. 

The  Bubstanoe  to  be  analysed  it  ooatatDed  in 
a  platinum  or  porcelain  boat  about  TO  mm.  long 
and  8  mm.  deep,  of  suoh  diameter  Uiat  it  nliiVa 
easily  in  Uie  combustion  tube.  It  may  ooo- 
venienlly  be  indoaed  in  a  small  w«ll-oo>ked  tnb« 
while  being  weighed. 

The  water  is  absorbed  by  granulated  anhy- 
drous calcium  chloride,  which  is  teeatad  with  a 


Pio.  17. 

current  of  dry  oarimn  dioxide,  and  then  with 
a  current  of  d^  air  to  convert  any  calcium  oxide 
present  into  carlionate,  and  thus  prevent  the 
bsorption  of  carbonic  dioxide. 
The  calcium  chloride  is  contained  in  a  U-tube 
provided  with  a  small  side  bulb  for  condensing 
the  water,  the  tube  from  tliis  bulb  fitting  directly 
into  the  cork  in  the  combustion  tube,  irtiilit  the 
otlier  limb  of  the  U-tube  is  closed  by  a  oaoutohouo 
cork  carrying  a  narrow  tube  lient  at  a  right  an^ 
and  connected  with  the  potash  bulbs^igs.  IS 


■od  19).  la  the  %imaoo  of  the  lide  bulb,  euh 
limb  of  the  tube  ii  oloeed  by  m  aaoatohona  oork 
ouiying  k  n&TTOw  tube  bent  at  a,  right  angle, 
one  of  these  tube*  fitting  diieotly  into  the  ooik 
of  the  oombaitiOD  tube,  and  tha  other  being 
oonneoted  with  the  potaah  bolba.  A  nnall  teat- 
tabe,  £-3  om.  long,  pUoed  in  the  upper  put  of 
the  6rBt  limb  of  tbe  U-tube,  ooUeota  the  greater 
part  of  the  «»ter.  Mid  tbn*  ptoteota  the  wloiam 
chloride  (No.  1,  %.  IT).  (For  other  forma  of 
ealcinm  ohioride  tabM,  a.  Chem.  Soo.  Proa  1906, 
22,87;   Chem.  Zeit.  1907,  31,  342.) 

A  ij-tabe  oontaioing  pumioe  moiateoed  with 
ationg  Bolphoria  ooid  mav  lito  be  need  to  oolleot 
tbe  water,  but  bulba  filled  with  the  Mod  mnat 
not  be  used,  mnoe  it  diaaolvea  an  appreciable 
quantity  of  oarbcm  dioxide. 

The  oaibon  dioxide  is  absorbed  in  a  itaong 
solution  of  potaauum  hydroxide  mode  by  dia- 


nlTing  this  aubElance  in  an  equal  quantity  ol 
mter.     The  eototion  to  oootamed  m  '  potaah 


tora  (No.  1)  w  itiU  u 


gas  n 


Pio.  19. 

form  devised  by  Bender  (Fig.  10]  secoiea  effiuient 
absorption,  arid  is  ooDvemeut  for  weighing,  at 
it  stands  either  on  its  own  base  or  on  an  ' 
minium  loot. 

Ilw  Goasler  or  Llebig  bulbs  must  contain 
tuoh  a  quantity  of  oaustio  potash  solution  Uiat 
it  washes  up  to  »  oertain  extent  in  Uu  lut 
bulb,  bat  yet  k  not  sntGcient  to  fill  the  lane 
first  bulb  in  esse  a  vaounm  it  produced  by  rapid 
abeorption  of  Uie  no.  In  addition  to  the  potash 
bulbtt,  »  U-tnbe  Sued  with  granulated  soda-lime, 
wiUi  a  layer  of  oaloium  ohioride  2  om.  deep  in  the 
upper  part  of  ecuih  limb,  is  used  to  absorb  the 
lut  traoes  of  the  gas  and  any  small  quantity  of 
moiatute  that  may  be  given  oS  from  tlie  oaustio 
potash  solution.  Two  suoh  soda-lime  tubea  may 
bo  used  in  plnoe  of  potash  bulbs.  (For  other  forms 
of  carbon  dioxide  absorption  tubes, v.  Chem.  Zeit. 
1900,  29.  HS;  1907,  31,  342;  1908,  32,  77; 
Amer.  Chem.  J.  1906,  36,  30fl ;  Ann.  Chim.  anal. 
ID07,  12,  318  ;  Chem.  Soc.  Proc.  1908,  24,  182.) 


The  tube  oontafaiing  the  nda-llme  Is  con- 
nected withaU-tabe  filled  with  oaloiam  chloride, 

protect  the  absorption  apparatus  from  mois- 
re ;  this  is  eepeciaUy  needful  when  the  air  is 
drawn  thioagb  the  apparatus  by  means  of  ao 
aspirator. 

The  oxygen  or  air  used  in  the  oombnstjon  is 
freed  from  carbon  dioxide  by  passing  through  a 
strong  solution  of  caustic  potash.  Ifoomprused 
oxygen  is  employed,  it  is  advisable  to  pass  it  first 
throD^jb  a  short  length  of  heated  combustion  tube 
containing  cuprio  oxide,  in  order  to  bum  out 
any  carbonaceous  impurity.  The  air  or  oxysm 
is  then  dried  by  passing  through  dry  calcium 
chloride  or  through  pamioe  moistened  with 
concentrated  sulphuric  acid,  the  same  deeio- 
cating  agent  must  be  used  to  dry  the  gas  as  is 
employed  to  colleot  the  water  produced  during 
the  oombuEtion. 

The  oxygen  Ii  dried  by  paasinf;  it  through 
two  long  u-tubes  containing  oaloiam  chloride. 
Instead  of  the  U-tubee  we  mai^  use  a  tall 
cylinder  with  the  lower  half  filled  with  soda-lime 
and  the  upper  with  oaloiam  ohioride. 

The  oxygen  required  for  combustions  in  the 

~~    tube  may  be  prepared  from   potasaium 

te  and  magnaneee  dioiide  and  stored  over 

in  gasholders  of  moderate  capacity.     Tha 

may  also  be  generated  as  required  by  the 

Followiiig  method,  which  fumishea  the  gas  under 


of  water,  antf  60  0.0.  of  sulphuric  acid 

itroduoed  drop  by  drop  into  a  litre  flask 

ainiuE  COO  0.0.   ot  hydrogen  peroxide   (10 

vols.}.     Tlie  gas  aontains  chlorine  and  oEOne, 

tvbioh  are  removed  during  its  passage  ttirough 

theTmriacrs(BaU.8oo.^m.  190r,r4j  1,001). 

The  optration.—'nte  tube  is  plaoed  in  the 
furnace  and  oonneoted  at  one  end  with  the  dry- 
ing apparatus  and  at  the  other  with  the  oaloinm 
^oride  guard  tube,  but  not  with  the  absoipticm 
apparatus.  It  is  gradually  heated  to  redness, 
a  current  of  dry  oxygen  is  pEissed  thnnigb  for  . 
half  an  hour  to  remove  all  moisture  and  organic 
matter,  and  the  tube  is  sllowed  to  cooL  When 
a  combustion  tube  is  l>eiiig  used  for  the  first 
time  or  after  a  long  intervid,  it  is  advisable  to 
carry  out  a  blank  experiment  bv  putting  on  the 
abstnption  apparatus  and  heating  the  tube  foe 
.._._  !_  _   _. (,(  ^  oiygon.     "  "~ 

_  . ._ .  lould    be 

constant.  The  solid  or  non-volatile  liquid  sub- 
stance is  now  weighed  into  the  platinum  boat, 
which  is  introduced  into  the  tube  by  removing 
the  long  copper  [due  at  the  back,  and  the  latter 
U  then  replaced.     The  "  ...... 


tubes  and  the  oxygen  reservoir.  The  burners 
under  the  front  part  of  the  tube  are  now  lighted 
and  the  temperature  gradually  raised  unt^l  the 
tube  is  at  a  dull-rod  heat  to  within  12  om.  of  the 
boat.  The  tube  in  contact  with  the  stopper  at 
the  front  end  should  be  so  hot  that  it  can  only 
just  be  touched  by  the  Gnger,  and  this  tempera- 
ture Bbould  tie  main tAi  lied  throughout  the 
operation  by  re^iulating  tha  first  two  burners,  in 
order  to  prevent  condensation  of  moisture  with- 
out decomposing  the  stopper.  If  any  wate> 
should  condense,  it  may  be  volatilised  by  bringing 


286 


ANALYSia 


one  of  the  hot  tfles  dose  over  the  tube.  The  last 
two  or  three  bnmen  under  the  long  copper  plug 
at  the  back  are  now  lighted  and  the  temperature 
gradually  raiaed  to  dull  redness,  whilst  at  the 
same  time  the  copper  oxide  is  heated  to  within 
0-6  cm.  of  the  boat,  and  a  current  of  oxygen  is 
passed  through  the  tube  at  the  rate  of  a  bubble 
eyery  two  seconds.  One  of  the  burners  under 
the  boat  is  then  lighted  and  the  boat  very 
gradually  heated,  combustion  being  regulated 
80  that  the  bubbles  passinginto  the  potasn  bulbs 
ean  easily  be  counted,  when  the  substance  is 
completely  carbonised,  the  temperature  of  the 
boat  is  raised  and  the  current  of  os^gen  increased 
to  a  bubble  per  second.  Towards  the  close  of 
the  operation  the  boat  is  heated  to  redness  and 
a  somewhat  more  rapid  current  of  gas  is  passed. 
It  is  not  necessary  to  heat  the  tuM  above  red- 
ness, and  a  higher  temperature  produces  distor- 
tion. When  combustion  is  complete,  the  current 
of  oxygen  is  continued  for  a  short  time  to  drive 
out  ah  carbon  dioxide  and  reoxidise  any  reduced 
copper.  When  the  oxygen  bubbles  through 
the  j)otash  bulbs  kt  tiie  same  rate  as  through 
the  dr3ring  apparatus,  the  oxygen  reservoir 
is  disconnected  and  a  current  of  Air  is  drawn 
through  the  whole  apparatus  to  expel  the  oxygen. 
At  the  same  time  the  tube  is  gradually  cooled 
and  is  ready  for  a  second  operation.  If  the 
tube  is  carenilly  heated  and  cooled,  it  may  be 
used  for  a  very  large  number  of  analyses.  The 
absorption  apparatus  is  disconnected  and 
weished.  All  the  weighings  should  be  made 
without  the  plugs  of  caoutchouc  tubing  and 
glass  rod  which  are  used  to  protect  the  contents 
of  the  tubes  and  bulbs  from  the  air.  When 
several  analyses  are  being  made  of  substances 
which  bum  only  with  difficulty,  the  entire  heat- 
ing may  with  advantage  be  carried  out  in  a 
current  of  oxygen,  and  some  saving  of  time  is 
effected  by  weighing  the  absorption  apparatus 
611ed  with  oxygen. 

Volatile  liquids  are  inclosed  in  a  small  thin 
cylindrical  glass  bulb  3  cm.  long,  with  a  capillary 
neck,  readuy  made  by  drawing  out  a  piece  of 
wider  tubing.  The  bulb  is  weighed,  heated,  and 
the  capillary  tube  immersed  beneath  the  liquid. 
As  the  tube  cools  a  small  quantity  of  the  liquid 
enters.  This  is  heated  to  boiling,  and  when  the 
air  is  expeUed  the  end  of  the  tube  is  again 

S laced  in  the  liquid,  and  when  the  vapour  con- 
enses  the  .bulb  is  completely  filled.  If  the 
liquid  is  very  volatile,  the  capillary  end  may  be 
sealed  before  weighing  the  tube,  but  usually  this 
is  not  necessary.  The  bulb  is  placed  in  the 
boat  with  the  capillary  end  open  and  directed 
towards  the  copper  oxide.  Combustion  is  con- 
ducted as  already  described,  but  much  ^;reater 
care  is  required,  especially  if  the  liquid  is  very 
y<^tile.  The  front  part  of  the  copper  oxide 
must  be  quite  red-hot  before  the  liquid  begins 
to  volatilise,  and  it  is  advisable  that  the  bulb 
be  empty  before  the  copper  oxide  near  the 
boat  is  heated.  With  an  iron  gutter  sufficient 
heat  is  conducted  to  vapourise  volatile  liquids, 
but  in  other  cases  a  very  low  flame  may  be 
used,  or  one  of  the  hot  tiles  may  be  held  over 
the  boat.  In  all  cases  it  is  difficult  to  prevent 
diffusion  of  vapour  into  the  back  of  the  tube  and 
even  into  the  drying  apparatus.  The  long 
copper  plug  at  the  back  increases  the  speed  of 
the  current  by  decreasing  the  diameter  of  the 


passage,  and  the  narrow  diameter  of  the  entrance 
tube  assists  in  a  similar  manner,  but  in  all  caaes 
of  the  analysis  of  a  volatile  substance  a  slow 
current  of  air  should  be  passed  almost  from  the 
beginning.  Later,  oxygen  should  be  passed,  but 
not  too  soon,  otherwise  an  explosive  mixture 
may  be  formed.  The  open  tube,  m  foot,  does  not 
yield  such  satisfactory  results  with  volatile 
liquids  as  with  other  substuicee,  and  in  such 
cases  combustion  should  be  made  by  the  follow- 
ing method. 

Lidng'9  original  method  <u  modified  by 
Bunsen.  Granular  cuprio  oxide  and  some  of  the 
finely  divided  oxide  are  heated  strongly,  and 
while  still  hot  are  placed  in  flasks  with  long  necks 


I 


Fig.  20. 

which  are  then  tightly  corked.  The  combustion 
tube  is  drawn  out  at  one  end  in  the  manner 
shown  in  the  figure,  and  sealed  at  the  point  a. 
A  layer  of  granular  cuprio  oxide 
about  10  cm.  long  is  first  intro- 
duced by  placing  the  combustion 
tubein  the  neck  of  the  flask  (Fig.  21) 
containing  it»  and  theA  2-3  cm.  of 
the  finely  divided  oxide.  The  sub- 
stance (about  0*6  gram)  is  now  intro- 
duced from  a  long  narrow  weighing 
tube  which  can  be  inserted  into  the 
mouth  of  the  combustion  tube,  and 
6-6  cm.  of  the  finely  divided  oxide 
is  added  and  intimately  mixed  with 
the  substance  by  means  of  a  Ions 
copper  wire,  the  lower  end  of  which 
has  two  twists  like  a  corkscrew  (Fig. 
22).  The  wire  and  sides  of  the  tuM 
are  rinsed  with  some  of  the  oxide,  and  Pio.  21. 
the  tube  is  filled  with  the  granular 
oxide  to  within  5-6  cm.  of  the  top,  and  a  plus  of 
cupric  gauze  inserted.  Every  care  must  be  tM^en 
to  prevent  absorption  of  moisture  by  the  cuprio 

« 

Of  ■^— m^— 1^  wi^ 

Fio.  22. 

oxide.  The  remainder  of  the  operation  is  con- 
ducted as  described  above,  and  when  combustion 
is  complete  the  drawn-out  end  of  the  tube  is  con- 
nected with  a  dr3ring  apparatus,  the  tip  broken 
off  inside  the  caoutohouo  tube,  and  a  current  of 
oxygen  and  afterwards  of  air  passed  through 
the  apparatus. 

In  whichever  way  the  oombustioo  is  made  it 
is  fowxd  that  the  peroenta^  of  hydrogen  is 
always  about  0-1-0*16  too  high,  a  result  attri- 
buted to  the  difficulty  of  perfectly  drying  the 
cuprio  oxide,  &>o.  It  is  frequently  stated  that  an 
open  tube  rarely  gives  correct  results  the  first 
time  it  is  used  ;  but  this  is  solely  due  to  neglect 
of  the  precaution  of  first  heating  in  a  current  of 
oxygen. 


ANALYSIS. 


287 


Ccmhwium  wUh  lead  chfwnate.  Sub- 
•tanoM  such  aa  graphite,  resiiiB,  &o.  which  are 
oxidised  with  great  difficulty,  should  be  burnt 
with  lead  ohromate,  or  in  extreme  cases  with 
lead  ohromate  containing  10  p.o.  of  potassium 
bichromate ;  these  oxidising  agents  can  be  em- 
ployed in  either  open  or  closed  combustion  tubea 
Th»  ohromate  is  precipitated  by  adding  potas- 
sium bichromate  to  a  solution  of  lead  nitrate, 
washed,  dried,  fused,  and  then  granulated.  It 
is  heated  immediately  before  Ming  used,  and 
the  tube  is  filled  in  the  same  manner  as  with 
copper  oxide  in  B.  llie  efficiency  of  the  lead 
ohromate  depends  mainly  on  the  fact  that  at  a 
hi^h  temperature  it  fuses.  After  being  used  it 
is  neated  with  nitrio  aoid  in  order  to  remove  the 
reduced  oxides,  and  is  washed,  dried,  and 
again  ignited. 

Carbon  and  hydrogtn  In  prwenee  of  nttrc^n, 
halogens,  &0.  When  nitn^en  is  present  it  is 
partly  converted  into  nitrogen  oxides,  which 
axe  absorbed  by  the  caustic  potash.  In  order 
to  avoid  this  source  of  error,  the  front  of  the 
tube  contains  plugs  of  copper  wire  gauze  or  a 
layer  of  granulat^  metallic  copper  12-15  cm. 
in  length  reduced  in  carbonic  oxiae.  The  copper 
is  heated  to  redness  throughout  the  operatioji, 
and  the  nitrogen  oxides  are  decomposed  with 
absorption  of  oxvgen  and  liberation  of  nitrogen. 
A  silver  gaufee  plug  is  preferable  to  the  copper, 
because  u  the  latter  is  reduced  in  hydrogen,  it 
18  apt  to  retain  water,  and  if  in  methyl  alcohol, 
it  may  also  contain  carbon  (Zeitsoh.  anal.  Chem. 
1906,  14,  741). 

Perkin  (Chem.  Soc.  Froo.  1880,  37,  457) 
employs  precipitated  manganic  oxide  made  into 
a  paste  with  a  saturated  solution  of  potassium 
ohromate  containing  10  p.c.  of  dichromate,  dried 
and  ^nulated.  A  la3rer  of  this  mixture  15  cm. 
long  IS  placed  in  the  front  of  the  tube  and  heated 
to  200^-250^  0.  AU  nitroffen  oxides  are  ab- 
sorbed, but  if  the  mixture  is  neated  too  stron^pr 
they  are  partially  expelled.  After  each  analysis 
the  mangle  oxide^  heated  more  strongly 
whilst  a  current  of  air  is-passed  through  the  tube, 
and  the  nitrogen  oxides  are  more  or  less  com- 
plet'Cly  driven  off. 

The  halogens,  when  present,  form  halide 
copper  salts,  which  are  somewhat  volatile  and 
are  liable  to  be  carried  into  the  absorption 
apparatus.  In  such  cases  the  front  layer  of 
ooiyper  may  be  replaced  by  silver  foil  or  gauze, 
which  decomposes  the  nitrogen  oxides  and  also 
absorbs  the  halogens.  Compounds  of  this  kind 
may  also  be  burnt  by  means  of  lead  chromate, 
(«,  supra),  or  a  mixture  of  the  substance  wiUi 
lead  chromate  may  be  placed  in  a  porcelain 
boat  and  burnt  in  a  current  of  oxygen  in  the 
usual  way  {cf.  Amer.  CShem.  J.  1906,  36,  631). 

Sulphur  forms  sulphur  dioxide,  which  is  ab- 
sorbed oy  caustic  potash.  Compounds  contain- 
ing this  element  may  be  burnt  with  lead  chro- 
mate, care  being  taken  that  the  front  of  the  tube 
is  not  too  hot ;  or  the  front  of  the  tube  may 
contain  a  somewhat  longer  layer  of  manganic 
oxide  and  potassium  chromate,  the  front  half 
being  kept  at  200^-250°  to  absorb  nitrogen 
oxides,  wtiilst  the  rear  half  is  heated  to  dull 
redness  and  'absorbs  the  sulphur  dioxide 
(Perkin,  2.c). 

Combustion  in  presence  of  a  contact 
ttibstanee.    The  use  of  a  special  combustion 


furnace  may  bo  obviated  by  bringing  a  mixture 
of  oxysen  and  the  vapour  of  the  organic  sub- 
stance neated  to  a  suitable  temperature,  into 
contact  with  some  active  material,  such  as 
platinum,  platinised  quartz,  platinised  asbestos, 
palladium,  or  even  finely  divided  copper  oxide. 
Tlus  process,  which  has  been  applied  successfully 
by  Dennstedt  and  his  collaborators  to  a  varied 
series  of  organic  substances,  is  carried  out  in  a 
hard-glass  or  quartz  combustion  tube,  about 
86  cm.  in  lengtn  and  16-18  mm.  in  diameter, 
the  contact  material  being  placed  about  the 
middle  of  the  tube.  Platinised  quartz  is  pre- 
pared by  soaking  thoroughly  clean  and  dry 
quartz  fragments  in  an  alcoholic  solution  of 
pyridine  platinichloride  and  igniting  them  over 
the  blow-pipe.  A  layer  of  about  3  cm.  of  this 
material  can  be  used  in  the  combustion,  or 
platinum  foil  or  wire  may  be  employed,  one  of 
the  most  efficient  forms  of  tlus  metal  being  a 
six-rayed  star  of  platinum  foil,  about  10  cm.  in 
lengthu  The  combustion  is  most  conveniently 
effected  in  a  double  supply  of  oxygen.  The 
boat  containing  the  substance  is  placed  in  the 
hard-glass  inner  tube  (18  cm.  in  length)  shown 
in  Fig.  23,  which  is  open  at  one  end  and  at  the 


Fig.  23. 

other  terminated  by  a  wide  capillary  tube, 
through  which  a  current  of  dry  oxysen  can  be 
introduced.  This  inner  tube  lias  a  diameter  of 
about  14  mm.,  and  oxygen  can  be  passed  through 
the  annular  space  by  means  of  the  T-tube  fitting 
over  the  capiUarv  tube  as  shown  in  the  figure. 

By  means  of  this  apparatus  the  supply  of 
oinrgen  required  for  vaporising  and  burning  the 
substance  can  be  carefully  regulated.  When 
the  organic  compound  contains  nitrogen,  sul- 
phur, or  halogens,  a  large  boat  containing  lead 
Eeroxide  is  placed  in  the  combustion  turo  and 
eated  to  300^-320^.  The  sulphur  is  absorbed 
in  the  form  of  lead  sulphate,  and  may  be  esti- 
mated by  extracting  the  lead  peroxide  with 
5  p.o.  sodium  carbonate  solution,  and  estimatins 
the  sulphate  in  the  filtrate.  The  estimation  of 
chlorine  and  bromine  may  be  similarly  effected. 
Iodine  is  not  entirely  absorbed  by  lead  peroxide, 
and,  accordingly,  *  molecular '  silver  must  be 
employed  to  take  up  this  element  (Dennstedt, 
Zeitsch.  angew.  Chem.  1005,  18,  1134 ;  19,  517 ; 
Chem.  Zeit.  1905,  29,  52;  1909,  33,  769; 
Analyst,  1905,  135 ;  Ber.  1908,  41,  600 ;  Ban- 
mert,  Ber.  1907,  40,  3475).  Walker  and  Black- 
adder  recommend  a  furnace  60  cm.  long,  with 
granular  copper  oxide  partly  placed  in  the 
combustion  tube  and  partly  mixed  with  the 
weighed  substance.  The  combustion  is  carried 
out  in  about  30  minutes,  and  the  tube  can  be 
heated  with  Bunsen  burners  on  an  ordinary 
working  bench  (Chem.  News,  1909,  99,  4;  c/. 
Marek  J.  pr.  Chem.  1906,  73,  359). 

Electrical  method.  In  this  proress  the 
electric  current  is  used  as  the  source  of  heat,  and 
platinum  as  the  catalyst.    A  Dennstedt  inner 


288 


ANALTSI& 


tube  u  employed  to  oontain  the  boat  z  with  the 
weiffhed  soManoe,  and  the  spiral  of  platinam- 
iridTum  wire  vj  is  wound  ronnd  a  porodain  or 
quartz  tube  held  in  position  in  the  combustion 
tube  by  a  nickel  tuM  dx,  passing  through  the 
indiarubber  stopper  a  The  coif  is  heated  to 
redness  by  the  passage  of  the  current  through 


DKJOP,  and  the  absorption  apparatus  is  fitted 
on  to  the  outer  end  of  the  niOKel  tube  dh.  A 
divided  stream  of  oxygen  is  em]doyed  as  in  the 
Dennstedt  process,  and  the  time  required  for 
complete  combustion  varies  from  15  to  40 
minutes. 

The  consumption  of    i^lectrical    energy  in 


i& 


^p^aa 


^?R 


«>«<j<«*  ^ 


Fio.  24. 


this  method  of  carrying  out  combustions  is 
small,  amounting  to  aoout  3*0  amperes  at 
64  volts  (194-4  watts)  during  the  time  when 
the  highest  temperature  is  obtained  (Breteau 
and  Lerona,  BulL  Soo.  chim.  1908,  [4]  3,  15; 
cf.  B.  Blount,  Analyst,  1905,  30,  29 ;  Morse  and 
Taylor,  Amer.  Chem.  J.  1905,  33,  591 ;  Morse 
and  Gray,  Amer.  Chem.  J.  1906,  35,  451; 
Garrasco  and  Planoher,  Gasz.  chim.  ital.  1906, 
36,  492 ;  Lippmann,  CSiem.  Zeit.  1905,  29,  487, 
174;  Tucker,  J.  Amer.  Chem.  Soc.  1907,  29, 
1442). 

intiogeil.  This  element  is  determined  in 
the  form  of  ammonia  (Will  and  Varrentrapp, 
Ruffle,  Kjeldahl),  or  in  the  form  of  nitrogen  gas, 
which  is  collected  and  measured,  the  weight 
being  calculated  from  the  volume  (Dumas,  Max- 
weUoimpson). 

A.  WiUandVarrenirapo'Bmdhod.  The  sub- 
stance is  heated  with  soda-lime  and  the  nitrogen 
is  evolved  as  ammonia,  which  is  absorbed  in 
hydrochloric  acid  and  precipitated  as  ammo- 
nium platiniohloride  or  estimated  volumetri- 
cally.  ^Diis  method  is  not  applicable  to  azor, 
diazo-,  nitro-,  and  nitroso-  denvatives,  and  to 
certain  albuminoid  substances. 

Soda-lime  is  prepared  by  slaking  2  parts  of 
good  quicklime  with  a  strong  solution  of  1  part 
of  sodium  hydroxide  free  from  nitrates  or  sul- 
phates. The  mixture  is  dried  by  heating  in  an 
iron  vessel,  granulated,  and  preserved  in  well- 
closed  bottles.  A  mixture  of  equal  parts  of 
calcium  hydroxide  and  anhydrous  sodium  car- 
bonate may  also  be  used. 

A  glass  tube  about  50  cm.  long  and  12  mm. 
diameter,  sealed  at  one  end,  is  filled  to  a  depth 
of  about  5  cuL  with  a  mixture  of  uihydrous 
oxalic  add  and  granular  soda-lime,  and  a  short 
plug  of  recently  ij^ted  asbestos  is  inserted. 
The  substance  is  intimately  mixed  with  sufficient 
finely  powdered  soda-lime  to  form  a  layer  about 
15  cm.  long,  and  is  quickly  introduced  into 
the  tube,  llie  mortar  is  rinsed  with  a  small 
quantity  of  soda-lime,  which  is  also  put  in  the 
tube,  and  the  latter  is  then  filled  with  granular 
soda-lime  to  within  5  cm.  from  the  end  and  a 
loose  asbestos  plug  inserted.  The  tube  is  tapped 
to  form  a  channel  over  the  powdered  soda-lime 
for  the  escape  of  the  gases,  and  is  placed  in  a 
furnace,  which  may  be  considerablv  shorter  than 
that  used  in  the  estimation  of  hydrogen  and 
oxygen.  The  combustion  tube  is  attached  by 
means  of  a  perforated  cork  to  an  apparatus  for 
absorbing  the  ammonia.  This  may  consist  of 
the  bulM  originally  devised  by  Will  and  Var- 


rentrapp, or  of  an  ordinary  bulb  U-tube. 
Winkler  hss  devised  a  oombmation  of  bulb 
and  flask  which  is  especially  convenient  for 
estimations  by  titration,  since  the  liquid  need 
not  be  transfened.  Ordinary  dilute  hydro- 
chloric acid  or  a  definite  volume  of  standard 
acid  is  placed  in  the  bulb.  The  tube  is  cpraduaUy 
heated  to  redness,  beginning  at  the  end  near 
the  U-tube,  and  when  decomposition  is  com- 
plete the  oxalic  acid  at  the  back  is  heated,  and 
the  ammonia  in  the  tube  is  driven  out  by 
the  current  of  carbonic  oxide  and  carbon 
dioxide.  The  excess  of  acid  is  then  determined 
by  standard  alkali ;  or  the  liquid  is  evaporated 
with  platinic  chloride  as  in  an  ordinary  estima- 
tion of  ammonia,  and  the  predpitate  is  washed 
with  ether  containing  a  small  quantity  of  alcohol, 
dried,  heated  in  a  crudble  till  completdv  deoom- 
posedf  and  the  nitrogen  calculated  from  the 
weight  of  the  residual  platinum.  Pt»N,.  The 
nitrogen  frequently  forms  volatile  bases  other 
than  ammonia,  and  hence  the  platinum  pre- 
dpitate cannot  be  weighed  as  such.  The  ratio 
of  platinum  to  nitro^n  is,  however,  the  same  in 
all  cases.  The  precipitate  is  washed  with  ether, 
because  if  such  bases  are  present^  it  may  be 
soluble  in  alcohol 

It  is  important  that  the  front  part  of  the  tube 
be  heated  sufficiently  to  secure  complete  decom- 
position, but  the  temperature  must  not  be  too 
high,  otherwise  part  of  the  ammonia  itsdf  is 
decomposed,  and  the  results  are  too  low.  Sub- 
stances rich  in  nitrogen  should  be  mixed  with 
some  pure  sugar  in  oraer  to  dilute  the  ammonia 
and  prevent  too  rapid  absorption. 

Various  modifications  of  Will  and  Yairen- 
trapp's  method  have  been  introduced  in  order 
to  make  it  more  generally  applicable,  but  theee 
processes  have  b«en  superseaed  by  Kieldahl's 
method  (c/.  Ruffle,  Ghem.  Soc.  Trans.  1881,  39 
87 ;   Arnold,  Ber.  1885,  18,  806). 

B.  Dumas*  method.  In  this  process  the  hydro- 
gen and  carbon  are  burnt  by  means  of  cujmc 
oxide  and  the  liberated  nitrogen  collected 
and  measured.  A  glass  tube  80  cm.  long,  12  to 
15  mm.  diameter,  sealed  like  a  test-tube  at  one 
end,  is  filled  to  a  length  of  12-15  cm.  with  dry 
sodium  hydrogen  carbonate,  4  cm.  of  ouprio 
oxide  is  added,  and  then  an  intimate  mixture 
of  the  substance  (0*3-0*6  gram)  with  cuprio 
oxide,  then  the  cupric  oxide  used  to  dean  the 
mortar,  a  layer  of  sranular  cupric  oxide,  and 
finally  a  layer  of  reduced  ffranuJated  copper  or 
copper- wire  gauze  not  less  uian  15  cm.  in  length. 
The  tube  is  connected  by  means  of  a  cork  and 


ANALYSIS. 


289 


bent  tabe  with  an  apparatua  for  collecting  the 
nitioffen.  The  sodium  hydrogen  carbonate  is 
first  lieated  until  all  air  is  exuelled  and  the 
issuing  gas  is  completely  absorbed  by  potash 
solution.  The  copper  is  then  heated  to  redness, 
tho  heat  being  gnidnally  applied  to  the  whole 
tube  as  far  asuie  carbonate.  When  combustion 
has  ceased,  the  carbonate  is  Ag&in  heated  until 
all  the  nitrogen  has  been  expeUed. 

The  most  convenient  form  of  apparatus  for 
collecting  the  nitrogen  is  that  deyised  by  H. 

Schiff  (Zeitsch.  anaL 
Chem.  7,  430),  or  a  simi- 
lar form  described  by 
Groves  (Chem.  Soc. 
Trans.  1880,  37,  600). 
The  former  consists  of  a 
burette,  ▲,  fitted  with  a 
heavy  foot  and  provided 
with  a  stop-cock,  e,  at 
the  top.  Close  to  the 
bottom  is  a  tubulus,  6, 
inclined  at  an  angle  of 
about  46*,  and  on  the 
other  side  is  another 
tubulus,  a,  connected  by 
means  of  a  caoutchouc 
tube  previously  soaked 
in  paraffin  with  a  globu- 
lar reservoir,  b,  which  is 
attached  to  the  burette 
bv  a  clip,  and  the  height 
of  which  is  readily  ad- 
justed. Mercury  is 
poured  into  the  burette 
thrpugh  the  lower  tubu- 
lus to  a  height  of  2  or 
3  mm.  above  the  lower 
opening,  and  the  reser- 
Fio.  26.  voir  is  then  filled  with  a 

solution  of  caustic  pot- 
ash in  its  own  weight  of  water,  the  lower 
tubulus  bemx  closed  with  a  cork.  The  stop- 
cock is  opened  and  the  reservoir  raised  until  the 
burette  is  completely  filled  with  the  alkaline 
solution.  '  The  stopcock  is  then  closed  and  the 
reservoir  lowered  to  the  bottom  of  the  burette. 
The  tubulus  may  now  be  opened  without  the 
mercury  or  alkaline  solution  being  forced  out. 
When  the  air  has  been  expelled  from  tiie  com- 
bustion tube  the  end  of  the  delivery  tube  is 
inserted  through  the  tubulus  and  the  nitrogen 
collected.  At  the  dose  of  the  operation  the 
temperature  of  the  gas  is  allowed  to  become  con- 
stant, the  reservoir  is  raised  so  that  the  level  of 
the  liquid  is  the  same  as  in  the  burette,  and  the 
volume  of  the  nitrogen  is  read  off,  together  with 
the  temperature  and  the  height  of  the  baro- 
n:oter.  The  weight  of  the .  nitrogen,  P,  is  then 
calculated  from  the  volume  by  means  of  the 
formula 

p      V(B  ~/)0'001251 
(1+0-00366<)760' 

where  V  is  the  observed  volume,  B  the  height 
of  the  barometer,  /  the  tension  of  aqueous 
vapour  at  the  temperature  t,  and  0'001261  the 
weicht  of  1  cc.  of  nitrogen  at  0°  and  760  muL 

Gatterman  (Zeitsch.  anaL  ChenL  24,  67) 
collects  the  nitrogen  in  an  apparatus  similar  to 
Schiff's,  but  not  graduated.  A  bent  tube  of 
small  diameter  completely  filled  with  water  is 

Vol.  L— T. 


attached  to  the  jet  of  the  burette  by  means  of 
caoutchouc  tubing.  By  closing  the  lower 
tubulus,  raisins  the  potash  reservoir,  and  opening 
the  stopcock,  the  gas  is  driven  over  into  a  gradu- 
ated tube  standing  over  water,  and  is  measured. 
The  error  due  to  tne  unknown  vapour  tension  of 
the  potash  solution  is  thus  avoided,  but  the 
vapour  tension  of  the  water  at  the  particular 
temperature  must  of  course  be  taken  into 
account.  Other  forms  of  apparatus  are  de- 
scribed by  Zulkowaky  (Annalen,  1876, 182,  296 ; 
Roscoe  and  Schorlemmer's  Chemistry,  3,  pt.  1, 
74)  and  Schwarz  (Ber.  1880,  13,  771). 

C.  MaaeweU  Simpson's  modification  of  Dumas* 
mdhod  (Chem.  Soc.  Trans.  1863, 6, 200 ;  Annalen, 
1866,  96,  74).  In  order  to  avoid  the  formation 
of  carbonic  oxide  and  nitric  oxido,  the  substance 
is  burnt  with  a  mixture  of  cupric  oxide  and 
mercuric  oxide.  Into  a  tube  similar  to  that 
used  in  Dumas'  method  is  introduced  about 

12  grams  of  manganese  carbonate  or  granulated 
magnesite  mixed  with  2  grams  of  precipitated 
mercuric  oxide,  followed  by  a  plu^  of  asoestos. 
Another  gram  of  mercuric  oxide  is  introduced, 
and  then  an  intimate  mixture  of  0*6  sram  of  the 
substance  with  46  parts  of  a  previously  prepared 
and  thoroughly  dry  mixture  of  4  parts  of  ignited 
cupric  oxide  and  6  parts  of  precipitated  mercuric 
oxide.  The  mortar  and  the  sides  of  the  tube  are 
rinsed  with  a  similar  mixture  and  another  as- 
bestos plus  is  introduced.  A  layer  of  nanular 
cupric  oxide  about  9  cm.  in  length  and  a  layer  of 
not  less  than  20  cm.  granulated  copper,  kept  in 
position  by  another  asbestos  plug,  fill  the  re- 
mainder of  the  tube.  After  tne  air  has  been 
expelled  by  heating  the  manganese  carbonate  or 
magnesite,  the  tube  is  gradually  heated  to  red- 
ness, beginning  from  uie  front.  The  metallic 
copper  not  only  decomposes  nitrogen  oxides,  but 
also  absorbs  the  excess  of  oxysen.  The  gas  is 
collected  as  in  Dumas'  methoa,  the  magnesite 
or  manganese  carbonate  providing  the  carbon 
dioxide. 

Certain  organic  compounds  (t,g,  hydroaroma- 
tic  series),  when  analysed  for  nitrogen,  evolve  a 
portion  of  their  carbon  as  methane,  which,  beins 
burnt  only  imperfectly,  adds  to  the  volume  of 
the  nitrogen.  In  these  cases  lead  chromate  is 
recommended  as  the  oxidising  sgent,  or  the 
substance  may  be  mixed  with  cuprous  chloride 
and  copper  oxide  (Haas,  ChenL  Soo.  Ptoc.  1906, 
22,  81). 

Various  modifications  of  Dumas' process  have 
been  proposed.  Thudichum  and  Wanklyn  use  a 
mixture  6  parts  of  normal  sodium  carbonate  and 

13  parts  of  fused  potassium  bichromate  in  place 
of  sodium  hydrogen  carbonate.  Groves  (^.c), 
with  a  view  to  usmg  the  same  tube  repeatedly, 
places  the  mixture  of  carbonate  and  bichromate 
in  a  small  tube  connected  with  the  combustion 
tube  by  an  indiarubber  'joint.  The  portion 
of  the  cupric  oxide  mixed  with  the  substance  is 
separated  from  the  layer  remaining  always  in  the 
tuoe  by  means  of  a  tight  plug  oi  asbestos  and 
copper  gauze,  the  latter  keeping  a  free  passage 
for  the  gas. 

The  combustion  tube  may  be  open  at  both 
ends,  the  rear  being  connected  with  an  apparatus 
for  generating  carbon  dioxide,  but  special  pre- 
cautions must  be  taken  to  obtain  this  gas  free 
from  air  (v.  Wanngton,  Chem.  Soc.  Trans.  1882, 
41,  340). 


290 


ANALYSia 


The  carbon  dioxide  required  for  this  modifica- 
tion of  I>umaa*  process  may  be  generated  in  a 
Kipp's  apparatus  by  tlie  action  of  hydrochloric 
acid  on  marble  or  oaloite.  These  minerals 
should,  however,  be  boiled  with  water  before 
beinff  used,  in  order  to  free  them  from  air.  The 
dioxide  may  also  be  generated  by  dropping  a 
oonoentrated  solution  of  potassium  carbonate 
(8p.gr.  1*5)  into  a  mixture  of  water  and  con- 
centrated sulphuric  acid.  A  convenient  ap- 
paratus in  which  to  effect  this  operation  is  shown 
m  the  accompanying  figure  (Young  and  Gaud- 


Fia.  26L 

well,  J.  Soa  Ghem.  Ind.  1907,  26,  184).  The 
carbonate  solution  fiows  from  the  dropping 
funnel  into  the  mercury  trap  and  out  into  the 
Woulflfs  bottie  through  the  small  hole  a.  The 
rate  of  evolution  is  regulated  by  the  exit  tap, 
and  «  is  a  safety  tube. 

In  both  IHimas'  method  and  Simpson's 
modification  the  combustion  tube  may  be  drawn 
out  at  the  front  end  and  connected  with  a 
Sprengel  mercury  pump  by  glass  tubing  joined 
by  short  pieces  of  caoutchouc  tubing,  the  joints 
being  surrounded  by  short  wide  tubes  filled 
with  water  or  glycerol.     A  bulb  is  blown  on  the 


/j^ 


FiQ.  27. 

horizontal  part  of  the  glass  tube  at  the  end  near 
the  combustion  tube,  and  this  bulb  is  kept  cool 
during  the  operation,  and  serves  to  condense  the 
water  which  is  formed.  The  combustion  tube  a 
made  vacuous,  and  when  no  more  air  issues 
from  the  end  of  the  pump,  the  combustion  is 
conducted  in  the  ordinary  way,  the  gas  which  is 
evolved  being  pumped  out  by  the  Sprengd  pump 
and  eollectea  m  a  suitable  tube.    No  magnesite 


need  be  used,  llie  copper  oxide  keeps  the  ex- 
hausted tube  from  ooUapsing  when  heated. 

In  many  oases,  especially  with  nitro-  deriva- 
tives, the  gas  generated  in  the  exhausted  tube 
is  a  mixture  of  nitrogen  with  nitric  oxide,  the 
latter  being  sometimes  present  in  considerable 
quantity.  It  is  advisable,  therefore^  to  de* 
compose  the  nitric  oxide  by  using  either  a 
layer  of  reduced  copper  or  a  long  plufl  of  silver 
gauze  placed  between  the  copper  oxiae  and  the 
exit,  and  by  keeping  this  material  heated 
throughout  the  combustion. 

Liquids  in  which  nitrogen  is  to  be  determined 
may  be  enclosed  in  bulbs  which  are  dropped  into 
the  combustion  tubes  as  in  the  determmation  of 
hydrogen  and  oxygen. 

The  cooper  onde  used  in  nitrogen  deter- 
minations SDOuld  be  prepared  by  heating  metaOio 
copper  in  air  and  never  oy  ignition  of  the  nitrate^ 
since  in  the  latter  case  it  is  apt  to  contain  basio 
nitrates  which  evolve  nitrogen  on  heating. 

The  copper  used  in  nitrogen  determinations, 
&o.,  diould  not  be  reduced  in  hydrogen,  since  it 
is  liable  to  occlude  this  gas.  It  may  be  reduced 
in  the  mixture  of  carbon  monoxide  and  carbon 
dioxide  obtained  b^  heating  oxalic  acid  with 
strong  sulphuric  acid.  Plu^  of  copper  gnauze 
mav  also  he  reduced  by  heating  them  to  redness 
and  dropping  them  into  a  test-tube  containing  a 
few  drops  of  formio  acid  or  methyl  alcohoL  ^e 
reducea  copper  is  carefully  dried  at  100^-110^. 

When  no  carbonate  is  used  and  the  gas  b 
simply  pumped  out  of  the  tube  and  coltected 
over  mercury,  it  consists  ol  a  mixture  of  car- 
bon dioxide  and  nitrogen.  If  the  former  is 
estimated  by  absorption  with  caustfe  potash,  a 
determination  oi  the  carbon  may.  be  combined 
with  that  of  nitrogen. 

Jannasch  and  Meyer  have  described  a  method 
for  the  simultaneous  estimation  of  carbon,  hydro- 

fen,  and  nitrogen  (Ber.  1886,  19,  949 ;  Annalen, 
886,  233»  375 ;   Zeitsoh.  anaL  Oiem.  1887,  26, 
86 ;  cj.  Bull.  Soc.  chitp.  1905,  83,  951). 

D.  KjeldahTs  method  (Zeitsch.  anaL  Oiem. 
1883,  22,  366)  The  substance  is  heated  with 
concentrated  sulphuric  acid  to  a  temperature 
approaching  the  l)oiling-point  of  the  latter,  and 
when  decomposition  is  complete,  an  excess  of 
solid  potassium  permanganate  is  added.  The 
nitrogen  is  thus  converted  into  ammonium 
sulphate,  which  is  then  distilled  with  excess  of 
alkali  and  the  ammonia  collected  and  estimated. 
Hub  method  is  economical,  requires  no  com- 
bustion furnace  or  special  apparatus,  is  rapid, 
and  requires  comparatively  little  attention,  so 
that  a  large  number  of  determinations  can  be 
earned  on  at  the  same  time.  The  substance  need 
not  be  in  a  very  fine  stete  of  division,  and  the 
method  is  especially  suitoUe  for  liquid  and  pasty 
substances  such  as  Extracts. 

It  is  important  that  the  sulphuric  acid  em- 
ployed for  these  determinations  should  be  pro- 
tected from  ammonia,  and  the  canstk  soda  mu- 
tion  should  be  well  boiled  in  order  to  expel  any 
ammonia  which  it  may  contain.  The  purity  of 
the  reagents  is  best  ascertained  by  making  an 
experiment  wiUi  pure  susar.  If  a  small  quantity 
of  ammonia  is  present,  we  same  quantity  of  tlie 
reagento  shoula  be  used  in  each  experiment^  and 
a  correction  made  for  the  ammonia  which  they 
contain. 

In  order  topre vent  bumpingduringdistilktioa 


ANALYSIS. 


291 


a  small  piece  of  zino  may  be  placed  in  the 
flaak,  but  it  ia  essential  that  the  soda  should  be 
free  from  nitrates  and  nitrites,  which  wonld  be 
lednced  and  yield  ammonia, 

Hie  time  zeqnized  for  the  operation  may  be 
considecably  shortened  by  using  sulphuric  a<»d 
containing  sulphuric  anhydride  or  phofephorio 
anhydride. 

The  method  as  thus  carried  out  is  applicable 
to  all  substanoes  which  can  be  analysed  by  Will 
and  Varrentrapp's  process,  and  to  many^  others. 

Heffter,  Hourung,  and  Morgen  (Zoitsch.  f. 
Cbem.  8, 432)  treat  1-0-1*5  grams  of  substance 
with  20  0.0.  of  a  mixture  of  4.  vols,  ordinary 
sulphuric  acid  and  1  tqL  of  fuming  acid,  and 
2  grams  of  phosphorus  pentozide.  Kreusler 
(ZcStsoh.  anaL  Ghem.  1885,  24»  453)  uses  sul- 
phnrio  acid  containing  200  grams  of  phosphorus 
pentozide  per  litre. 

WiUarth  (CSiem.  Zentr.  TS]  16,  17,  113)  finds 
that  the  ozkUktion  of  the  organio  matter 
takes  place  much  more  rapidly  in  presence  of 
certain  metallic  oxides.  Mercuric  oxide  ii  the 
^most  eiBoient,  but  eupric  oxide  answers  almost 
^equally  well.  The  former  produces  merouri- 
anunoninm  deriyatives,  whion  are  not  readily 
decomposed  by  caustic  soda,  and  hence  the 
•llrnHfiA  liquid  must  be  mixed  with  some  potas- 
sium sulphide  to  decompose  the  mercury  com- 
pounds. The  merouric  sulphide  formed  makes 
the  liquid  boil  regularly  without  the  addition 
of  zino.  Ulsoh  recommends  the  use  of  ferrous 
sulphate  instead  of  potassium  sulphide ;  it  may 
be  added  before  the  oaustlo  soda. 

Warington  (Ghem.  News,  1885,  52,  162) 
remoTes  nitrites  and  nitrates  by  boiling  with 
ferrous  sulphate  and  hydrochloric  acid. 

With  a  view  to  secure  the  reduction  of  nitro- 
deriratiyes,  fta,  and  thus  make  the  process 
seoflrally  applicable,  Asboth  (Ghem.  Zentr.  [3] 
l7,  161)  mixes  0*5  gram  of  the  substance  with 
1  {pram  of  pure  sugar  in  the  case  of  readily 
oxidisable  compounds,  and  with  2  grams  of 
benzoic  acid  in  the  case  of  nitrates  and  similar 
deriyatiyes.  Most  probably  the  benzoic  acid 
first  forms  nitro-  deriyatives,  which  are  after- 
wards reduced.  He  adds  Bochelle  salt  with  the 
caustic  soda  in  order  to  preyent  precipitation  of 
manganese,  Ac,  and  thus  ayoids  bumping 
during  distillation.  With  these  modifications 
the  method  is  applicable  to  all  nitrogen  com- 
pounds exoe|^  those  of  the  pyridine  and  quino- 
nne  series.  £.  Arnold  {%b.  p.  337)  uses  0*5  gram 
of  anhydrous  eupric  sidphate  and  1  gram  of 
metallic  mercury  in  place  of  the  oxides  as 
recommended  by  Wilfarth,  and  heats  1  mm  of 
the  substance  with  these  and  20  c.c  of  smphuric 
aokl  containing  20-25  p.c.  of  phosphoric 
oxide. 

G.  Arnold  (Arch.  Pharm.  [3]  24, 785)  confirms 
Asboth's  statements,  but  finos  that  in  addition  to 
^f^ndhie  and  quinoline  compounds,  azo-  deriya- 
tiyes and  nitrites  yirld  unsatisfactory  results. 
He  heats  0-5  gram  of  substance  with  0*5  gram 
of  anhydrous  eupric  sulphate,  1  gram  of  metallic 
mercury,  2  grams  of  phosphoric  oxide,  1  gram 
of  sugar,  and  in  case  of  nitrates,  &a,  2  gpims  of 
benzoic  acid,  and  20  c.c  of  sulphuric  acid. 

Beitmair  and  Stutcer  (Rep.  AnaL  Ghem.  5, 
232;  Zeitsch.  anaL  (Siem.  1886,  25,  582)  use 
about  0*7  gram  of  mercuric  oxide  and  20  c.o  of 
sulphuric  acid,  with  a  small  fragment  of  paraffin 


in  the  case  of  substanoes  rich  in  fat.  They 
regard  the  use  of  phosphoric  oxide  as  uimeces* 
sarr,  and  the  use  of  fuming  sulphuric  acid  as 
unaeeirable  on  account  of  its  liability  to  contain 
nitrogen  oxides. 

jMlbauer  (Ghem.  Zentr.  [3]  17,  433)  usee 
phenolsulphonic  acid  in  place  of  benzoic  acid^ 
and  reduces  with  zinc  dust.  He  thus  obtains 
flood  results  eyen  with  nitrates.  Beitmair  and 
Stutzer  (Rep.  AnaL  Ghem.  7,  4)  find  that  the 
nitrate  must  be  somewhat  fhiely  diyided;  0*5 
to  1*0  gram  of  the  substance  ia  mixed  with 
50  c.a  of  sulphuric  acid  oontaininfl  20  grams  of 
phenol  per  litre,  allowed  to  stana  for  a  short 
time  with  occasional  agitation,  mixed  with  2-3 
grams  of  dry  zinc  powder  and  1  or  2  drops  of 
metallic  mercury,  and  heated  in  the  usual  way. 
Gonyersion  into  ammonium  sulphate  requires 
one  and  a  half  hours. 

A  most  important  improyement  in  the 
Kjeldahl  process  due  to  Gunning  (Zeitsch.  anaL 
Ghem.  28,  188),  consists  in  Uie  addition  of 
potassium  sulj^te  to  the  concentrated  sul- 
phuric acid.  The  solution  of  potassium  hydro- 
gen sulphate  in  concentratea  sulphuric  acid 
Doib  at  a  temperature  considerably  aboye  the 
boiling-point  of  the  strong  acid  and  the  oxidation 
of  the  ovganic  matter  is  thereby  greatly  facili- 
tated, "^^ous  oxidising  and  catelytic  agents 
may  be  employed  in  conjunction  with  this 
mixture,  and  the  following  are  among  the 
many  which  haye  been  suggested  in  addi- 
tion to  those  already  mentioned:  platinic 
chloride,  ferric  chloride,  manganese  oioxide, 
magnesia,  and  sodium  phosphate.    The  use  of 

Sotassium  permanganate  has  now  been  aban- 
oned,  and,  in  the  case  of  refractory  substances, 
oxidation  is  now  generally  induced  by  the 
catalytic  action  of  mercuir  or  its  oxide.  The 
following  process  is  described  by  Dyer  |phem. 
Soc.  Trans.  1895,  67,  811).  The  substance 
(0*5-5  crams)  is  introduced  into  a  round- 
IxyttomM  Jena  flask,  and  heated  gently  with 
20  acof  concentrated  sulphuric  acid  containins 
a  small  globule  of  mercury.  After  the  initial 
action  hM  subsided,  the  temperature  is  raised  to 
boiling,  and  in  15  minutes  10  grams  of  potassium 
sulphate  are  added,  and  the  boiling  continued 
till  the  solution  is  clear  and  colourless.  The 
flask  is  closed  with  a  loosely  fitting  bulb  stopper, 
from  the  internal  projection  of  which  the  con- 
densed sulphuric  acid  drops  back  into  the  fiask. 
There  is,  therefore,  little  loss  of  acid  except 
through  reduction  to  sulphurous  add.  The  pro- 
duct IS  rinsed  into  a  capacious  Jena  distilling 
flask,  rendered  stronsly  alkaline  with  sodium 
hydroxide,  with  the  addition  of  a  small  quantity 
of  sodium  sulphide,  and  the  liquid  distilled  in 
a  current  of  steam,  the  ammonia  being  collected 
and  estimated  in  the  usual  way. 

When  nitrates  are  present,  Jodlbauer's 
modification  i»  employed,  but  the  phenol  may 
conyeniently  be  replaced  by  salicylic  acid. 
When  the  solution  of  this  substance  in  concen- 
trated sulphuric  acid  is  poured  quickly  on  to 
the  weighed  material,  the  loss  due  to  the  forma- 
tion of  lower  oxides  of  nitrogen  is  avoided,  and 
satisfactory  results  are  obtained  even  when 
ammonium  nitrate  is  present.  This  circum- 
stance is  of  great  importance  in  connection  with 
the  analysis  of  compound  fertilisers  containing 
both  ammonium  salts  and  alkali  nitrates.  Then 


lino  and  mrnnin  ■re  ailded  while  Cha  solutioo 
1b  itill  oold,  HiQ  the  former  inet4l  allowed  to 
dinolre  before  Uw  nuztore  ii  heated.  Other 
rednoing  agents,  anoh  u  mgar  and  Bodium 
thiosul^tate,  may  be  used  either  aJone  or  in 
oonjanctioD  with  lino.  By  the  aid  of  tbifl 
mooified  proocM  tatitfactory  reeultB  an  obtained 
in  the  an^yna  (rf  oiganio  mtro-,aEO-,*ad  hydraio- 
dMJTatiTea.  It  baa  not  been  fomid  poosible  to 
obtain  correct  eaUmatknos  of  nitiogeo  in  aodiam 
nitroprunide,  T^tenylhydraEine  and  it*  deriva- 
tives, and  in  rniztim*  oontaining  laige  propor- 
tiona  of  ohloridea  and  nitrates  (e/.  J.  Amer. 
Chem.  Soo.  17,  &67 ;  Analyst,  190e,  3U ;  Ber. 
I90S,  88,  BSQ  i  Oiem.  Soo.  Proo.  1901,  26,  3S1 ; 
1003,  27,  988). 

The  literatnze  of  nitrogen  determinations  is 
eztremelT  volaminona.  Sommalies  of  oontribn- 
tioDi  to 'this  mbjeot  will  be  found  in  Zeitaoh. 
anal.  Chem.  1884,  23,  BSl ;  24,  439  ;  26,  424  and 
f~,\;  2e,  249  ;  and  Chem.  Newt,  1888,  S7,  62, 
«f  teq.  In  addition  to  the  referenoee  already 
given,  papen  relating  to  Ejeldahl's  piooea*  may 
be  foand  in  Zeitach.  anal.  Chem.  24,  199,  3B8, 
and  393 ;  26,  149  and  IfiS ;  26,  92 ;  27,  222  and 
S9S. 

CUorliw,  bnmiiu,  uid  lodlna. 

By  lime.  A  tube  abont  40  om.  long  and 
7  mm.  diameter,  iealed  at  one  end  like  a  teet- 
tube,  is  Blled  to  a  ^'V!^  °'  ^  "'"'■  ^'^^  P™" 
granulated  qnioklime.  Thr  luhatanoe  is  vei^hed 
into  the  tube  and  mixed  with  finely  powdered 
lime  by  meanaof  a  oopper  wire  twisted  at  the  end 
like  a  corkaorew.  The  wire  and  tutie  ai«  rinsed 
with  lime,  the  tobe  ie  filled  to  within  6  cm.  of 
the  open  end  with  granulated  lime.  The  tube 
is  grodnatly  heated  to  redneaa  from  the  front. 
When  oold  the  contents  of  the  tnbe  are  diawllTed 
in  water  slightly  acidified  with  nitric  acid, 
qitond,  and  the  halogen  precipitated  by  ulver 

In  the  ease  of  iodine  the  substanoe  ia  dissolved 
in  water,  filtered,  mixed  with  silver  nitnte,  and 
finally  acidified,  in  order  to  avoid  liberation  of 
iodine.  A  further  precaution  oonaists  in  adding 
a  lltUe  sodiuDi  lulphite  before  eaidi  addition  of 

When  the  substance  contains  niliogen,  oyan- 
idcs  may  be  formed ;  bat  tliia  ia  avoided  by 
using  pure  soda-lime  in  place  of  lime.  If  the 
lime  contains  sulphates,  some  sulphide  ia  liable 
to  be  produced.  (On  the  preparation  of  pnre 
lime,  »te  Zeitsch.  anoL  Oiem.  4,  01  and  16,  6.) 

Liquids  aie  ooatained  in  small  bulbs  with 
oa]Hllary  openinA  wliiah  are  dropped  into 
the  tnbe  before  ffllins  up  with  lime.  The  tuba 
must  tie  very  groduuly  heated,  and  should  be 
longer  than  ubiuL 

C(inWsnuMoiJ(Annaten,  1360,  116,  1 ;  1866, 
136,  129 ;  Ber,  1870,  3,  697).  The  substance 
is  oxidised  by  lieating  with  nitrio  acid  in  sealed 
tubes  in  preaenoe  of  silver  nitrate.  In  many 
oases  aeia  of  sp.gr.  1-2  and  a  temperature  of 
12O*-2O0*  will  niffioe ;  but  substanoee  whinh 
are  more  difficult  to  oxidise  require  acid  of 
ap.gT.  1-42,  mixed  in  special  oasee  with  aome 
potaasiiun  diohromatc^  <k  the  foming  aaid  of 
nkgr.  1-S  may  be  uaed.  If  necessary  Uw  tnbea 
may  be  heated  as  higb  as  DOO*.  The  quantity 
of  aoid  naed  should  not  be  more  than  twice 
that  tbsOTeticallv  required  for  complete  oxida- 
tion, and  the  tube  must  not  contain  more  tlian 


4  grams  of  nitric  acid  for  each  60  &&  of  its  votume. 
iTtbe  .  


tube  of  thin  glaas  of  such  len^-that 
its  mouth  projects  above  the  nitrio  acid  in  the 
tube,  and  the  aaid  doee  not  come  in  contact 
with  the  anbatanoe  until  the  tube  is  sealed. 
The  tnbea  used  should  be  atiout  16  mm.  in 
diameter  and  l'S-2  mm.  thick  in  the  glaM. 
After  introduption  of  the  snbetaaoe  they  am 
drawn  oat  to  a  cainllaiy  tube  with  thick  walla, 
which  is  then  sMled.  The  sealed  tnbea  are 
heated  in  a  praaure  tube  fnmaoe  tilted  at  one 
end  BO  that  the  capillary  ends  of  tlte  tabes  do 
not  come  into  contact  witb  the  liquid.  After 
being  heated,  the  tut>ea  should  on  no  acoonnt 
lie  removed  from  the  proteoting  iron  or  steel 
tube  until  they  liave  been  opened.  For  this 
purpose  the  tubes  are  held  in  positioD  by  means 
of  a  oork  collar  through  which  the  capillaiy 
ends  project  out  of  the  furnace.  The  capillaty 
end  is  firet  gently  warmed  to  volatilise  any  con- 
densed aoid,  and  then  heated  more  sttoogly 
until  the  gases  under  -pntmrn  blow  a  bote 
through  the  softened  tip  of  the  sealed  oapiUuy. 


gases  is  very  great,  and  it  i*  extremely  dangerona 
to  attempt  to  open  the  tnbe  with  a  file.  Tlie 
tube  furnace  should  only  be  used  tor  this  pur- 
poae  within  a  well-protected  enclosure  (Fig.  28), 
so  as  to  minimise  the  personal  risks  arising  from 
explosions  of  the  heated  tubea. 


Via.  S8. 

The  silver  salt  formed  ia  rinsed  out  of  the 
opened  tnbe  and  teeated  in  the  usual  wa^. 

For  the  estimation  of  iodine  in  organic  com- 
pounds this  method  is  to  be  prefeired  to  the 
time  process,  liut  as  the  silver  nibate  and  silver 
iodide  frequently  form  a  fused  ycjlow  mas^ 
the  mixture  must  be  extracted  thoroughly  with 
hot  water  in  order  to  remove  the  fotnter  saJt- 
The  silver  balide  ohtaJned  by  the  Ckriua  meUiod 
is  collected  in  a  tared  Oooah  cruoible,  washed 
successively  with  water  and  alcohol,  dried  at 
100*,  and  weighed. 

Sttpanoufi  mtthoi.  The  snbatance  is  boiled 
witb  alcohol  (20-40  CO.)  and  sodium  is  added 
at  such  a  rate  that  a  vigorous  leaotioD  Is  main- 
tained. A  large  exoesa  of  the  metal  is  essential 
xa-)-2Na-t- C^,-OH-XH-|-Naa+C  ,H  .-OKa. 


ANALYSIS. 


898 


When  all  the  Mdium  has  dissolved,  20-^40  0.0.  of 
water  are  added,  and  the  alcohol  removed  by 
diBtiUation.  The  aqneons  solution  is  addified 
with  nitric  ack!*  and  the  halogen  estimated 
gravimetricallyi  or  volnmetrically  by  Volhard's 
method  (Ber.  1906,  39,  4066;  of,  Bacon,  J. 
Amer.  CShem.  Soo.  1909,  31,  49).  By  using  the 
Utter  method  and  weighing  the  mixed  silver 
haJides,  the  two  halogens  can  be  estimated 
indirectly  in  the  same  compound. 

Pringsheitih,'s  method  consists  in  burning  the 
organio  sabstcuioe  with  sodium  peroxide.  Com- 
pounds oontainine  more  than  75  p.c.  of  carbon 
are  mixed  with  18  parts  of  this  oxidising  aoent, 
and  those  with  50-75  p.o.  of  carbon  with  16 
parts.  Substances  containing  less  than  25  p.c. 
of  carbon  are  mixed  with  sugar  or  naphthalene, 
and  treated  with  16-18  parts  of  the  peroxide. 
The  mixture  is  placed  in  a  steel  crucible  sur- 
rounded by  water  and  having  a  perforated  lid 
through  which  a  dowing  iron  wire  is  thrust  to 
cause  ignition.  &e  jproduct  is  extracted  with 
water,  acidified  with  nitric  acid,  and  the  halogen 
estimated  m  the  usual  way  (Ber.  1903,  36,  4244 ; 
1904,  37,  324 ;  1905,  38,  2459 ;  Amer.  Chem.  J. 
1904,  31,  386;  e/.  Moir,  Chem.  Soc.  Proo.  1907, 
23,  233 ;  Baubigny,  BulL  Soo.  ohim.  1908,  (iv.) 
3,630). 

Svlphiir  and  phosplionif • 

Non-vdatile  substances.  Pure  caustic  potash 
is  fused  in  a  silver  dish  with  about  one-sixth  its 
weight  of  potassium  nitrate  and  a  little  water.' 
When  cola  the  substance  is  weighed  into  the 
dish,  which  is  again  heated,  the  substance  being 
mixed  with  the  alkali  b^  means  of  a  silver 
spatula.  When  oxidation  is  complete,  the  mass 
is  allowed  to  cool,  and  is  then  dissolved  in  water 
acidified  with  hydrochloric  acid,  and  the  sul- 
phuric or  phosphoric  acid  estimated  in  the  usual 
way. 

Car%us*s  mdhod  is  carried  out  exactly  as  in 
the  estimation  of  the  halogens.  Sulphur  is 
oxidised  to  sulphuric  acid  and  phosphorus  to 
phosphoric  acid.  It  is  advisable  to  remove  the 
greater  part  of  the  nitric  acid  before  precipita- 
ting banum  sulphate  or  magnesium  ammonium 
phosphate. 

Another  method  applicable  to  volatile  and 
non-volatils  substances  is  as  follows: — Into  a 
combustion  tube  40  cm.  long,  sealed  at  one  end, 
is  introduced  2-3  grams  of  pure  mercuric  oxide, 
then  a  mixture  of  the  substance  with  equal  pro- 
portions of  merouxio  oxide  and  pure  anhydrous 
sodium  carbonate,  and  the  remainder  of  the 
tube  is  filled  with  sodium  carbonate  mixed  witJi 
a  small  quantity  of  mercuric  oxide.  The  open 
end  of  the  tube  is  dosed  by  a  cork  carrying  a 
glass  tube  dipping  under  water,  in  which  the 
mercury  is  condensed.  The  tube  is  carefully 
heated  so  that  the  front  layer  of  sodium  car- 
bonate is  red  hot  before  the  substance  begins  to 
volatilise.  The  substance  is  tben  rapidly  heated, 
so  that  decomposition  is  complete  m  about 
fifteen  minutes,  and  finally  the  mercuric  oxide 
at  the  rear  end  of  the  tube  is  heated  until 
oxygen  issues  from  the  end  of  the  delivery- 
tube  (Russell,  Chem.  800.  Trans.  1854,  7,  212 ; 
J.  pr.  Chem.  1855,  64,  230).  The  contents  of 
the  cooled  tube  are  dissolved  in  \i'ater,  a  smaU 
quantity  of  bromine  water  added  to  oxidise  any 
sulphide,  the  solution  acidified  with  hydrochloric 
acid,  boiled  to  expd  bromine,  and  the  sulphuric 


acid  or  phosphoric  acid  estimated  in  the  usual 
way. 

Many  non-volatile  substances  may  be  oxi- 
dised by  heating  with  pure  concentrated  caustic 
potash  solution,  diluting  with  twice  the  volume 
of  water,  and  treating  with  a  current  of  chlorine. 
After  complete  oxidation  the  solution  is  acidified, 
heated  to  expel  chlorine,  and  the  sulphuric  or 
phosphoric  acid  determined. 

Arssoie.  The  estimation  of  this  element  in 
organic  compounds  has  recently  acquired  in- 
creiased  importance  owing  to  the  appUoation  of 
these  substances  in  therapeutics.  One  of  the 
earliest  methods,  due  to  La  Coste  and  Michaelis 
(Annalen,  1880,  201,  224),  consisted  in  mixing 
the  substance  with  soda-lime,  and  heating  the 
mixture  in  a  stream  of  air  or  oxygen.  The 
residue  was  dissolved  in  nitric  or  hydrochloric 
add,  the  arsenic  precipitated  as  sulphide,  and 
afterrmrds  converted  into  magnesium  pyro- 
arsenate.  MonthouM  recommends  destrojring 
the  organio  matter  with  nitric  acid  containing 
magnesium  nitrate,  when  a  final  ignition  leads 
to  the  formation  of  magnesium  arsenate  (Ann. 
Chim.  anal.  1904,  9,  308). 

Pringsheim  oxidises  the  organic  arsenic 
derivative  with  sodium  peroxide,  and  estimates 
the  arsenic  as  magnesium  pyroarsenate  (Airer. 
Chem.  J.,  1904,  31,  386). 

The  following  procedure  has  been  shown 
to  be  applicable  to  the  orsanio  arsenical 
drugs  now  on  the  market.  The  substance 
(0*1M)*3  gram)  is  mixed  with  10-15  grams 
of  sodium  peroxide  and  sodium  carbonate  in 
equal  proportions,  the  mixture  heated  gently 
in  a  nickd  crucible  for  15  minutes,  and  the 
temperature  then  raised  to  duU  redness  for 
5  mmutes.  The  product  is  extracted  with  water, 
25-31  CO.  of  sulphuric  add  (1:1)  added,  and 
the  solution  concentrated  to  100  c.c,when  1  j^rani 
of  potasdum  iodide  is  added  and  the  hquid 
boiled  down  to  40  c.c  After  destroying  any 
trace  of  iodine  with  a  few  drops  of  sulphurous 
acid,  the  solution  is  diluted  condderably  with 
hot  water,  and  the  arsenic  precipitated  as  sul- 
phide. The  precipitate,  after  washing  three  times 
with  hot  water,  is  dissolved  with  20  cc.  of 
i\r/2-sodium  hydroxide,  and  the  filtered  solution 
treated  with  30  cc  of  hydrogen  peroxide  (20 
vols.),  the  excess  of  this  reagent  being  destroyed 
by  heating  on  the  water-bath.  A  few  drops 
of  phenolphthalein  are  added  followed  suooes- 
dvdy  by  11  co.  of  sulphuric  acid  (1:1)  and  one 
gram  c^  potasdum  iodide ;  the  solution  is 
evaporated  down  to  40  cc.  and  the  pale-ydlow 
colour  removed  by  sulphurous  acid.  Cold  water 
is  then  added,  and  theculuted  solution  neutralised 
with  2J\r-sodium  hydroxide,  and  just  acidified 
with  sulphuric  acid.  The  arsenite  solution  is 
now  titrated  with  standard  iodine  solution  and 
starch  in  the  presence  of  sodium  hydrogen 
carbonate  or  sooium  phosphate  (Little,  Cahen, 
and  Morgan,  C!hem.  Soc  Trans.  1909,  95,  1477). 

Antimony.  When  present  in  organio  com- 
pounds, this  element  may  be  estimate  by  acidi- 
fying the  product  of  the  sodium  peroxide  fusion 
(v.  Arsenic,  supra),  and  precipitating  as  sulphide, 
this  precipitate  being  collected,  washed,  and 
weighed  in  the  manner  indicated  under  Oravi' 
metric  determinations. 

Oiygen.  No  satisfactory  method  has  yet 
been  devised  for  the  direct  determination  of  this 


294 


ANALYSIS. 


etoment,  and  it  it  nsaall j  Mtimated  by  differenoe 
(v.  ▼.  Banmhauor,  Annalmi,  90,  228;  Zeitaoh. 
aoaL  Cflieii].  6,  141 ;  Stromeyer,  Annalon,  117, 
217 ;  Mitacherlioh,  Zeitaoh.  anaL  Chem.  6,  136 ; 
7,  272;  13,  74^  and  16,  371;  Ladenbnig, 
Annalmi,  135,  1 ;  Maumen^  Compt.  rend.  66, 
432 ;  and  Grcrfcin,  Zeitaoh.  anaL  Chem.  13,  1). 

Proxtanala  aoaljnlf  of  carbon  oompouiids. 

The  methoda  to  be  adopted  for  the  separation 
of  the  oonstitaents  of  any  particular  mixtare 
will  depend  entirely  upon  the  nature  of  the 
mixtme.  It  ia  onljr  poeeible  to  deeoribe  the 
general  methoda  whioh  are  foond  to  be  moat 
asefnl  in  ofganic  analyaia.  To  a  certain  limited 
extent  these  operationa  are  applicable  to  the 
proximate^  anajyais  of  complex  inorganic  mix- 
tures. 

FraeUondl  dUtiOtUUm  ia  available  for  the 
separation  of  liquida  which  differ  considerably 
in  their  boiling  j^inta  (v.  Distillation). 

Distillation  m  a  cnrrent  of  steam  is  fre- 
quently employed  aa  a  method  of  proximate 
analysis.  Li  this  way  volatile  organic  acids 
can  DO  separated  from  volatile  baaes  bv  steam- 
distilling  the  mixture  in  the  presence  of  mineral 
acids.  On  the  other  hand,  volatile  basea  are 
separated  from  organic  acids  by  distilling 
in  steam  the  mixture  of  these  substances 
rendered  alkaline  by  sodium  or  potassium 
hydroxide. 

FraeUonal  pncipUatian  may  be  employed 
for  the  separation  of  substances,  some  oi  wluch 
are  precipitated  by  a  given  reagent,  whilst  the 
others  are  not;  or  for  the  separation  of  sub- 
stances which  differ  in  the  order  of  their  preci- 
pitation. If,  for  example,  silver  nitrate  is  added 
m  successive  small  auantitiee  to  a  solution  con- 
taining an  iodide,  oromide,  and  chloride,  the 
6rBt  portion  of  the  precipitate  contains  the 
greater  part  of  the  iodine ;  the  middle  portion 
contains  the  greater  part  of  the  bromine ;  and 
the  last  TOrtion  the  greater  part  of  the  chlorine. 
In  a  similar  manner  organic  acids  can,  not  un- 
freanently,  be  separate  by  taking  advantage 
of  diiferencea  in  tne  order  of  their  precipitation 
by  silver  nitrate  or  lead  acetate.  In  these  caaes 
the  separated  precipitates  can  be  suspended  in 
water  and  decomposed  hj  hydrogen  sulphide, 
when  the  acids  are  Again  liberated. 

Fradumal  arystaUisaium  mav  be  adopted  in 
the  case  of  substances  which  dioer  in  their  solu- 
bility in  one  and  the  same  solvent.  The  solution 
is  concentrated  soQiowhat,  and  the  crystals  whioh 
separate  are  removed ;  the  mother  liquor  is  still 
further  concentrated,  and  the  second  crop  of 
crystals  is  removed,  this  process  being  repeated 
aa  often  aa  the  case  demands.  The  least  sbluUe 
compound  is  mainly  in  the  first  crop  of  crystals ; 
the  most  soluble  is  in  the  last  mother  liquor. 

Fraetional  saituration  is  an  analogous  pro- 
cess, but  is  of  more  limited  application.  It  was 
employed  by  liebig  for  the  separation  of  volatile 
organic  aokos.  The  mixture  of  acida  is  mixed  with 
a  quantitv  of  caustic  soda  or  potash  insufficient 
for  complete  saturation,  and  is  then  distilled. 
The  acida  of  higher  molecular  weight  are  first 
neutralised  and  converted  into  salta,  which  of 
course  remain  in  the  retort,  whilst  the  acida 
of  lower  molecular  weight  are  found  in  the  free 
state  in  the  distillate.  Anythhig  like  complete 
separation  ia  only  to  be  obtained  by  many  repe- 
titions of  this  process. 


Fraelumdl  aolirftofi. — ^The  most  useful  and 
most  generally  applicable  method  of  proximate 
analyna  ia  based  upon  the  different  aolubilities 
of  various  substances  in  different  meostnia. 
The  mixture  ia  treated  successively  with  variona 
solvents,  each  of  iHiich  dissolves  some  of  the 
constituents,  but  leavea  the  others  undissolved. 
Advantage  may  also  be  taken  of  the  fact  that  the 
solubilities  are  in  many  cases  modified  by  a  rise 
of  temperature.  Further,  if  two  substances  differ 
considerably  in  their  solubility  in  one  and  the 
same  liquid,  they  may  be  sepuated  by  treatment 
with  successive  small  quantities  of  the  liquid, 
whkih  removes  the  more  soluble  compound  bat 
leaves  the  ^;reater  part  of  the  other  nndissolved. 
The  following  is  a  list  of  the  solvents  commonly 
employed,  with  indications  as  to  their  general 
properties  :— 

Water  " 


manv  aalts  and  adds;  in- 
organic and  orgai^c  alkalis  and  their  aalts; 
carbohydrates,  gums,  certain  alooholi,  poly- 
hydric  phenoli,  and  other  highly  oxidised 
carbon  compounds  which  are  not  readily  solu- 
ble in  alcohol,  ether,  &c.  On  the  other  lumd,  it 
does  not  dissolve  the  carbonates,  phosphates, 
oxalates^  and  certain  other  salta  of  the  heavier 
metals.  Very  manv  organic  substances  are  in- 
soluble in  this  liquid.  It  decomposes  the  halocen 
compounds  of  the  acid  radicles  and  certain  otner 
compounds,  and  converts  many  normal  metallic 
salts  into  basic  salts,  part  of  the  acid  passing  into 
solution  in  the  free  state. 

Dilate  acids  will  dissolve  many  salts,  and 
alK>  some  organic  substances  which  are  insolaUe 
in  water. 

Alcohol  dissolves  many  salts,  caustic  alkalis, 
hydrocarbons,  fatty  acids,  resins,  and  a  very 
liotte  number  of  carbon  compounds.  It  reacts 
wiui  many  haloid  substitution  derivatives,  and 
hence  is  not  a  suitable  solvent  for  this  class  ol 
compounds.    - 

Ether  dissolves  a  few  salts,  and  Is  an  excel- 
lent solvent  for  hydrocarbons,  fats,  resins,  alka- 
loids,  and  almost  all  organic  compounds  which 
are  insoluble  in  water.  It  reacts  with  very  few 
substances,  and  boili  at  a  low  temperature,  so 
that  it  can  readily  be  distilled  off  and  the  dis- 
solved substance  recovered. 

Benzene  diuolves  iodine,  sulphur,  phos- 
phorus, oils,  fata,  wax,  camphor,  resins,  caout- 
chouc, sutta-percha,  &0.,  and  is  especially  useful 
as  a  solvent  for  haloid  derivatives,  on  which  it 
has  no  action.  In  certain  instances  this  hydro- 
carbon may  be  replaced  by  its  homolognes, 
toluene,  and  the  xylenes. 

Carbon  disulpnide  shares  with  ether  the 
advantage  of  beins  readily  volatile.  It  should 
always  ^purified  from  dissolved  sulphur  before 
beiiiff  used!  The  best  plan  is  to  mix  it  witii  a 
smafl  quantity  of  white  wax,  and  then  distil  off 
the  disulphide  on  a  water-bath.  It  dissolves 
sulphur,  phosphorus,  iodine,  fats,  essential  oUa, 
resins,  caoutchouc,  &c  ;  but  its  solvent  powers 
are  comparatively  limited,  and  almost  all  salts 
and  very  many  carbon  compounds  are  insoluble 
in  it. 

Light  petroleum  consists  of  the  more  volatile 
hydrocarbons  of  the  paraffin  series.  It  occois 
in  commerce  in  several  varieties  under  different 
names^  Petroleum  eiher  boils  at  fSXf-W ;  pefro- 
leum  heniene,  at  70*-90'* ;  Ugroin,  at  90^-120*. 
They  are  excellent  solvents  for  oils  and  fats^  but 


ANALTSia. 


295 


dksdvo  very  few  other  oompoimds.  Three 
mdes  of  light  petroleum  are  now  obtainable 
for  nae  aa  aolvents,  boiling  reapeotiTely  at  40*-60*» 
eO*-80*.  and  SO^-lOO*. 

Chloroform  readilj  disBolves  oils,  fats,  and 
similar  substances,  ana  is  especially  useful  as  a 
soWent  for  alkaloids. 

The  ohloro-  deriTatiyes  of  ethane  and 
ethylene  have  been  introduced  as  useful  non- 
inflammable  soWents  for  oils,  fats,  or  resins; 
these  liquids  give  a  wide  ranfle  of  boiling-points 
and  solvent  action  (Koller,  7w  Oongress  Applied 
dbemistry,  1900).  A  large  number  of  other 
solvents  are  applkd  in  certain  special  cases,  and 
amon^  those  more  commonly  employed  may  be 
mentioned,  acetone,  eth^l  acetate,  amyl  alcohol, 
pyridine,  aniline,  and  nitrobensene. 

The  treatment  of  a  solid  with  a  yolatile 
solvent  must  be  conducted  in  a  special  apparatus, 
especially  if  the  liquid  Is  to  be  neated.  various 
forms  of  apparatus  have  been  devised  for  this 
purpose,  but  there  is  none  more  efficient  than 
that  of  Sozhlet  (Dui^L  poly.  J.  232,  461).  It 
consists  of  a  short  wide  test  tube  (■),  open  at 
the  top  but  dosed  at  the  bottom,  to  which  is 
sealed  a  narrower  tube  (v)  which  can  be  fitted 

A 


^. 


m 


Fio.  29. 


Fxo.  30. 


into  a  small  weighed  flask  by  means  of  a  cork. 
Communication  between  the  two  tubes  is  made  by 
means  of  (1)  a  narrow  side  tube  («)  which  opens 
into  the  bottom  of  the  wider  upper  tube,  forms 
a  siphon,  and  descends  through  the  lower  tube 
neany  to  the  bottom  of  the  flask;  and  (2)  a 
wider  side  tube  {t)  which  enters  the  upper  tube 
near  the  top  and  Uie  lower  tube  near  the  junction 
(Fig.  29).  A  weighed  quantity  of  the  substance 
to  be  treated  is  placed  in  a  cylmder  of  filter 
paper  open  at  the  toi>,  and  introduced  into  the 
upper  tube,  or  the  bottom  of  the  tube  is  packed 
with  purified  cotton  wool,  and  the  substance  is 
plaoea  upon  this.  A  quantity  of  the  solvent 
rather  more  than  sufficient  to  ml  the  upjper  tube 
to  the  level  (d  the  bend  in  the  siphon,  is  placed 
in  the  flask  and  heated  to  boiling  by  means 
of  a  water-bath.  The  upper  tube  is  attached 
to  a  reflux  condenser,  caro  oeinj^  taken  that  the 
condensed  liquid  falls  directly  mto  the  cylinder 
containing  the  substance.  The  vapour  passes 
op  the  wide  side  tube,  is  condensed,  faDs  upon 
the  substance,  and  filters  through  the  paper  or 
cotton  wooL    Ab  soon  as  the  liquid  rises  to  the 


bend  of  the  siphon,  the  latter  draws  off  the  dear 
solution  into  the  flask,  and  the  liquid  is  again 
volatilised  whilst  the  dissolved  matter  remains 
in  the  flask.  The  process  goes  on  automatically, 
and  the  substance  can  be  eztraoted  many  times 
with  a  small  quantity  of  liquid.  When  extrac- 
tion is  complete,  the  flask  is  connected  wHh  an 
ordinary  condenser,  the  liquid  is  distilled  off, 
and  the  residue  dried  and  weighed  if  necessary. 

A  convenient  apparatus  for  treatment  with 
solvents  in  dishes  has  been  described  by  A.  W. 
Blyth  (Chem.  Soa  Trans.  1880,  37, 140). 

In  many  cases  substances  in  solution  can  be 
removed  and  separated  by  agitatioff  the  liquid 
with  some  non-misoible  solvent.  l£e  alkaloids 
and  many  amines  oan  be  removed  from  aqueous 
solutions  by  means  of  ether,  whilst  metallic  salts 
aro  left ;  fatty  substances  oan  be  removed  from 
liquids  by  means  of  light  petroleum,  and  so  on. 
Extractions  of  this  land  are  best  made  in  a 
separator  consisting  of  a  somewhat  wide  tube 
contracted  at  one  end,  which  is  fltted  with  a  cork 
or  stopper,  whilst  the  other  end  is  drawn  out 
into  a  narrow  tube  provided  either  with  a  stop- 
cock or  an  indiarubber  tube  and  a  pinch-cook 
(Fig.  30).  The  liquid  and  the  solvent  oan  be 
completely  mixed  oy  agitation,  and  after  they 
have  separated  the  lower  layer  oan  be  drawn 
off.  If  it  is  required  to  remove  the  supernatant 
liquid  in  this  or  any  similar  ease,  a  somewhat 
narrow  tube  is  bent  twice  at  right  angles,  and 
one  limb  is  fitted  by  means  of  a  cork  into  a  dis- 
tilling or  other  flask,  which  is  connected  with 
an  aspirator,  whilst  the  other  limb  of  the  tube 
is  placed  in  the  li<^uid.  When  the  aspirator  is 
set  in  action,  the  liquid  is  drawn  over  into  the 
flask,  from  which  it  can  be  distilled.  With  care 
a  very  aocurate  separation  can  be  made,  and 
the  tube  is  readily  rinsed  by  drawing  some  of 
the  fresh  solvent  through  it.  This  method  may 
be  rendered  approximately  quantitative  by  cali- 
brating the  alx>ve  cylindrical  separator  (Fi^.  30). 

The  microscope  is  of  the  neatest  serviee  in 
ascertaining  whether  a  substance  is  a  single 
compound  or  a  mixture,  and  a  microscopic 
examinatioo  of  the  various  products  obtained 
in  the  course  of  a  proximate  analysis  affords 
valuable  information  as  to  the  extent  to  which 
separation  has  been  effected. 

Estimation  ov  Radicals  oomuonly  ooccb- 
Buro  m  Oboanio  O)MP0uin>s. 

In  this  section  it  is  only  possible  to  indicate 
briefly  a  few  of  the  most  seneral  methods  bv 
which  certain  typical  radicals  present  in  organio 
compounds  can  be  estimated. 

HydloiyL  A  known  weight  of  the  hydrox^lio 
compound  is  treated  with  excess  of  magnesium 
metnyl  iodide  (Grignard's  reagent),  and  the 
amount  of  methane  evolved  is  measured  in  a 
gas  burette  (Fig.  31). 

ROH+CH.-Mgl-ROMgl+CH^. 

The  organio  masnesium  compound  is  dis- 
solved in  dry  amyl  etner  or  phenetole,  and  if  the 
hydroxylic  compound  is  too  insoluble  in  either  of 
these  solvents,  it  may  be  dissolved  indnr  pyridine. 

(Hibbert  and  Sudborough,  Chem.  Soo.  Trans. 
1004,  86,  933;  and  Zerewitinoff,  Ber.  1007,  40, 

2023.) 

This  process  has  been  extended  to  the 
estimation    of   sulphydryl-    (SH),    imino-.  and 


>■   groupg,   (Ad   for   aU   uitive   hydiogea 
I  (</.  Ber.  190S.  41,  2233  Mtd  302S}. 


Hm  MtimAtlon  of  methozyl, 
pceMot  In  mM)7  natnnllj  oooor: 
Gompoanda,  ia  mnemlly  kooohi 
Zaiwl'i  method,  which  oouisb  in 


ring  . 
iplMi 


'!^    P. 


with  K  Dixtnra  of  this  acid  «td  Metic  anhydride. 
Methyl  iodide  i«  evolved  uid  abnrbed  in  aloo- 
hidio  mlver  nitMte,  with  the  leeolt  that  tUvia 
iodide  it  jnecipitatod,  each  moteoolar  propor- 
tioD  of  Uui  auMtanoe  being  equivalent  to  one 


lieated  in  afilyoerine  bath  at  130^-140°.  a  earrent 
of  owbon  dioxide  being  pamod  through  the  mix- 
ture of  mbttance  and  oonoentrated  hydiiodio 
acid.  The  beatitig  it  oontjnned  for  one  how, 
and  the  temperature  finally  lateed,  k>  that  the 
hydtiodic  an,d  boila  mitlj,  but  without  dia- 
tJlliug  into  the  ride  tube  of  the  diatiUing  flaak. 
The  methyl  iodide  is  collected  in  two  flaaka,  b, 
containing  alocdioUo  silver  nitrate.  The  precipi- 
tated (ilrec  iodide  is  treated  with  nitno  acid, 
the  alcohol  eTai>orat«d,  and  the  precipitate  col- 
lected and  weighed  in  the  luoal  manner. 

Hewitt  and  Jonea  (Chem.  Soc.  Trans.  1919, 
116,  193)  oombine  the  methyl  iodide  with  pyci- 


idide  in  an 


nI  lolMeqnently  by  aevenl  inTe« 
mbener,  Monatah.  ISM.  IS,  901 ; 
Boo.  Tnni.  1903,  S3.  1367 ;   Hea 


modified  ml 
(H-Baml 

Cbem  Soo.  Trani.  1903,  S3.  1367 ;  H^aaa,  Bet'. 
1906.  89,  1142;  Deober.  Ber.  1003,  36.  2896; 
Hewitt  and  Moore.  Chem.  Boo.  Trans.  1902,  81, 
318).  Of  theaa  modifloatiooa  Perkin'a  (fig.  32) 
is  ptobaUy  the  aimpleet ;  it  oonaiate  n(  a  distil- 
Ung  &aak,  a,  with  a  veir  long  neck  (20-26  cm.) 


eetimated  volometncaliy. 
The  pyridine  and  ita  metliiodide  are  dilated  with 
water,  acidified  with  nitric  acid,  a  known  amount 
of  silver  nitnte  added,  and  the  exceaa  of  the 
latter  determined  by  thiocyaoate  aecotdiog  to 
Volhard'a  method. 

Zeiael's  method  and  its  modificationa  am 
applicable  lo  the  estimation  of  ethoiyl,  but  the 
resulta  obtained  are  generally  leas  accurate. 

MethyL 

A  further  modiSoation  at  Zeisal'a  method 
rendera  it  available  for  the  eatimayon  of  methyl 

Kupa  attached  to  nitrogen.  'Dw  snbetauM  ia 
ted  with  ooncentr»t«d  hydriodio  acid  and 
dry  ammonium  iodide,  and  the  methyl  iodide 
evolved  dealt  with  in  the  manner  mdioated 
above  (Hersig  and  H.  Meyer,  Ber.  ISH,  37. 
319;  Monatak  1894,  IS.  613;  1896,  16,  690  j 
IS&7,  18,  379 :   Kirp<  Ber.  190B,  41,  820). 

AeMll 

It  is  only  possible  in  oompaistively  few  oasea 
to  determtoe  with  certainty  by  ultimate  analyna 
the  number  of  acetyl  gronpa  existing  in  organio 
compounds.  For  example,  the  mono-,  di-,  and 
tri-  aoetyl  derivatives  of  the  trihydroxylieniaoea 
have  appoximately  the  tame  peroentage  oom- 
poaition.  Theee  and  other  ■■mil"'  aoetyl  deri- 
vates  are  hydrolyaable  by  standard  caustic 
alkalis  employed  in  alcoboUo  tolutiona,  e*«o 
wlieii  they  are  not  readilvattaoked  in  aqueous 
Bolutiona  (Benedikt  and  Dlser,  Monatah.  1S87, 
8.  41 ;  Van  Bomburgli,  Rec  trav.  obim.  1882, 
1,  48 ;  R.  Meyer  and  Hartmann.  Ber.  1906,  38, 
30S6).  Acid  hydrolyaia  nuty  be  employed  in  a 
large  number  of  oaaea  ana  tbe  voutile  acetio 
aoid  diatilled  into  rtuidud  alkali,  the  e^NM 
of  which  ia  determined  by  alkalimetrv.  Aoootd- 
ing  to  Wemel's  piooeaa,  the  acetyl  derivativa 
ia  first  hydrolyaea  by  moderately  strong  anl- 
phnrio  acid  (1 :  2H,0^  and  tbe  mixtnre  tmated 
with  moDCaodium  [diaaphate  and  boiled  down 
to  dryneai ;  the  ■nlphuric  acid  b  fixed  aa 
sodium  sulphate,  and  the  aoetio  aoid  ia  distilled 
into  a  known  exceaa  of  standard  alkali,  the 
diatillation  heing  carried  out  under  reduced 
pteasure  (Monatsh.  1803, 14,  478 ;  1897,  IS,  669). 

The  deatnotive  action  of  strong  solphntM 
acid  on  orotknJc  oomponnda  may  bv  avoioed  by 
the  use  ol  Uie  aromatic  anl[4ionie  acids  aa  hydro- 
lytio  agents.  The  acetyl  compound  la  diatilled 
in  ateam  in  a  10  p.0.  scdution  of  benBStieeo]- 
phonic  acid  or  ooe  of  the  naphtbaleneaulphoiua 
acids ;  the  distillate,  which  contains  all  Uie 
aoetio  aoid  fnmiahed  by  the  hydrolyaia,  ia  titrated 
with  standard  barium  hydroxido  {Sudborough 
and  Thomaa,  Cheoi.  Soo.  Trans.  1906,  87, 
1762). 


ANALYSIS. 


297 


A.  G.  Perkin  bydrolyses  the  acetyl  oompound  i 
with  alcobolio  sulphuric  aoid,  adding  frosh  alcohol  | 
from  time  to  time.  The  ethvl  acetate  obtained 
in  the  distillate  is  then  hydrolysed  with  a  known 
amonnt  of  standard  caustic  alkali,  and  the 
excess  of  the  latter  ascertained  with  standard 
acid  (Chem.  Soc  Trans.  IQOi,  8ff,  1462 ;  lOOfi^ 
87.  107  ;   1907,  91,  1230) 

Garboxyl. 

In  many  eases  the  nnmbor  of  carbozyl 
(GO«H)  groups  in  an  organic  compound  can  oe 
determined  by  the  analysis  of  its  neutral  salts. 
For  this  purpose  the  silver  salts  are  generally 
selected,  as  they  are  usually  anhydrous,  and 
indicate  the  normal  basicity  of  the  organic  acid. 
'Hie  aromatic  hydrozy-oarboxylic  acids  {e.g.  1 : 6- 
dinitro-p-hydroxybenzoio  acid)  take  up  two 
atoms  of  silver,  one  replacing  the  oarboxylic, 
and  the  other  the  phenolic  hydrogen.  Some 
sflver  salts  of  organic  acids  are  sensitive  to 
light,  and  others  are  very  explosive.  The  more 
stable  ones  can  be  analvsed  by  direct  ignition 
and  weighing  the  residual  silver.  In  other  cases 
the  organic  matter  must  be  destroyed  with 
nitric  aoid,  and  the  silver  estimated  as  chloride 
in  the  acid  liquid. 

Other  metallic  salts  are  frequently  employed 
in  determining  the  basicity  of  carboxylio  acids, 
and  it  is  advisable  before  arriving  at  a  final 
conclusion  to  estimate  the  metals  in  a  series  of 
these  compounds. 

If  the  molecular  weight  of  a  oarboxylic  aoid 
is  Imown,  the  basicity  can  often  be  determined 
by  titration  with  aqueous  or  alcoholic  sodium, 
potassium,  or  barium  hydroxide ;  the  indicators 
generally  employed  are  phenolpbthalein,  methyl 
oranse,  and  lacmoid. 

llie  following  indirect  method  has  been 
recommended  (P.  0.  McUhiney,  Amer.  Chem.  J. 
1894,  16,  408)  for  the  estimation  of  oarboxyl 
^proups.  The  substance  (1  gram)  is  dissolved 
m  excess  of  alcoholic  potash,  the  alcohol  being 
at  least  93  p.o.  The  solution  is  saturated  with 
carbon  dioxide  until  the  excess  of  alkali  is 
precipitated  as  carbonate  or  bicarbonate.  The 
precipitate  is  collected  and  washed  with  alcohol, 
the  nitrate  is  distilled  to  remove  the  solvent, 
and  the  residue  containing  the  potassium  salt 
of  the  ofganio  acid  is  custilled  with  10  p.a 
aqneous  ammonium  chloride,  the  ammonia 
evolved  beinff  estimated  in  the  usual  way. 
Each  moleouEir  proportion  of  ammonia  corre- 
sponds with  one  oarboxvl  group.  This  method 
is  applicable  to  the  weaker  fatty  acids. 


Carboxyl  can  be  etUmatod  by  a  method 
based  on  the  following  reaction : — 

6RCO^+5KI+KIO,=6RCOtK+  3I,+3H,0 
The  weighed  substance  is  digested  for  12  hours 
with  an  aqueous  solution  of  pure  potassium 
iodide  and  iodate  in  a  stoppered  verael.  The 
mixture  containing  the  uberated  iodine  is 
rinsed  unto  the  generating  vessel  of  a  gas 
volumeter  and  treated  with  alkaline  hydrogen 
peroxide,  when  the  oxygen  evolved 

I,4-2KOH+H,0,=2KI-f-2H,0+0, 

is  a  measure  of  the  carboxyl  groups  ozieinally 
present  (6C0sH  =  30,)  (Baumann-Kux,  kitsch. 
anaL  CSiem.  1893,  32,  129 ;  Annalen,  1904,  335, 
4;  e/.  Groger,  Zeitsoh.  angew.  CShem.  1890,  3, 
363,  385).  It  should  be  noticed  that  acidic 
substances  not  containinff  carboxyl  groups  (e.^. 
picric  acid)  Uberate  io<une  from  the  iodide- 
iodate  mixture. 

CtfbonyL 

The  oarbonyl  group,  whether  raesent  in 
aldehydes  B<X)-H  or  ketones  B<GO*B',  can  be 
detected  bv  means  of  the  following  colour- 
reaction.  An  aqueous  or  alcobolio  solution 
of  the  substance  is  treated  with  a  0*5  to  1  p.c 
solution  of  the  hydrochloride  of  an  aromatic 
meta-diamine  (meta-phenylenediamine  or  its 
homoloffues),  when  in  a  few  minutes  an  intense 
^[Teen  fiioresoence  is  developed,  which  attains 
its  maximum  intensity  after  two  hours.  All 
aldehydes  eive  this  reaction,  but  the  mixed 
ketones  and  ketonic  acids  do  not  (Windisoh. 
Zeitsch.  anaL  Chem.  1888,  27,  514). 

Practically  all  aldehydes  restore  the  colour 
to  the  following  solution  (Schiff's  reagent).  A 
litre  of  0*10  p.c.  magenta  solution  is  decolourised 
by  addinff  20  c.a  of  sodium  bisulphite  solution 
(30^^.)  followed  after  one  hour  Dy  10  c.c.  of 
concentrated  hydrochloric  acid.  (For  the  ex- 
ceptions, c/.  Bitt6,  Zeitsch.  anaL  Chem.  1897, 
36,  375.)  The  reaction  has  also  been  utilised 
quantitatively  (McKay  Chase,  J.  Amer.  Chem. 
Soc.  1906,  28,  1472;  Schimmel  &  Co.,  Ber. 
190'7,  123). 

Phenylhydrazine  condenses  with  aldehydes 
and  ketones,  yielding  phenylhydrazones.  When 
the  mixture  is  treated  with  Fehling's  solution 
(70  grams  CuS04,6H.O,  350  ^ms  Roohelle 
salt,  and  260  erams  KOH,  in  2  btres),  the  excess 
of  phenylhydrazine  is  decomposed,  evolving 
nitrogen  • 

C,H,*NH*NH,+0=C,H,+H,0+Np 


Fio.  33. 


298 


ANALYSIS. 


while  the  phenylhydrazone  remains  unchanged. 
The  estimation  isoairied  out  in  aflask,  b,  oonncct- 
ed  with  a  carhon  dioxide  generator,  a  (Fic|.  33).  A 
known  voltune  of  Baireewil's  solution  is  intro- 
difoed  and  covered  with  a  layer  of  petroleum  to 
prevent  the  oaostio  potash  Irom  aosorbing  the 
carbon  dioxide.  A  bluik  experiment  is  first  made 
with  the  standard  Mdution  of  phenylhydradne 
hydrochloride  and  aqueous  sodium  acetate,  the 
mtroflen  evolved  on  heatine  the  solutions 
togetner  being  collected  in  a  Sooiff's  nitrometer, 
F.  The  experiment  is  then  rejpeated  with  the 
same  solutions  of  phenvlhydrazine  and  sodium 
acetate  pUu  the  carbonyl  oompotmd;  the 
difference  between  the  two  volumes  of  nitrogen 
collected  is  a  measure  of  the  carbonyl  present 
in  the  compound  (Strache,  Monateh.  1891,  12, 
624;  1892,  13,  299;  1893,  14,  270;  Watson 
Smith,  GheuL  News,  1906,  93,  83). 

When  the  oarbonyl  compound  {e,a.  pyruvic 
acid)  condenses  leaculy  with  phenylhydrazine 
or  its  hydrochloride  in  aqueous  solution,  the 
exceoi  of  this  base  can  be  estimated  by  adding 
excess  of  ^/10-iodine  solution,  and  titrating 
the  remaining  iodine  with  standard  sulphurous 
acid  or  thioeulphate,  using  starch  as  indicator. 
This  estimation  is  based  on  the  following 
reaction :'— 

CA-NHNH,+2I,=3HI+C,HJ+N,. 
The  phenylhydrasEone  is  not  affected  by  the 
iodine  solution  (R  v.  Meyer,  J.  pr.  Chem.  1887, 
[2]  30,  115;  c/.  Petrenko-Entschenko,  Ber. 
1901,  34,  1699;  and  Annalen,  1905,  341, 
15,  150). 

Organle  aminei. 

The  organic  amines  are  divisible  into  three 
elasses,  primairy,  secondary,  and  tertiary, 
oontaininff  their  nitrogen  atoms  combined 
respectivdy  with  one,  two»  and  three  organic 
groups.  Ineee  szoups  may  be  either  aliphatic 
or  aromatic,  ana  the  reactions  of  each  of  the 
three  dasses  of  amines  depend  very  lar^^ely  on 
the  nature  of  the  organic  groups  to  which  the 
basic  nitrogen  atom  is  attached. 

Primary  amines.  The  primary  amino- 
group  C'NHa  may  be  detected  by  the  carbyl- 
amine  reaction  (Hofmann,  Ber.  1870,  3,  767), 
irrespective  of  the  nature  of  the  organic  group, 
whicn  may  be  either  aliphatic,  aromatic,  or 
hydroazomatio  (e/.  Monatsh.  1896,  17,  397). 
^e  test  consists  in  warming  the  substance  in 
alcoholic  solution  with  chloroform  and  caustic 
potash,  when  a  oarbylamine  (iso-nitrile)  is 
produced,  which  has  a  pungent  disagreeable 
odour : 
R-HN,+CHCa,+3KOH«RNC+3KCl+3H,0. 

The  primary  amines  all  interact  with  nitrous 
acid,  out  the  aliphatic  bases  are  immediatelv 
converted  into  hydroxyl  derivatives  (alcohols), 
whereas  the  aromatic  bases  furnish  diazo- 
derivatives  from  which  the  nitrogen  is  evolved 
rapidly  on  wanning  or  slowly  at  the  ordinary 
temperature. 

In  the  case  of  the  aliphatic  primary  amines, 
this  nitrogen  can  be  collected,  and  the  amount 
indicates  the  proportion  of  amino-  groups 
present.  As  nitrous  acid  itself  decomposes 
readily,  evolving  oxides  of  nitro^n,  Stan6k 
recommends  the  use  of  nitroeyl  oblonde,  obtained 
by  adding  fuming  h^drochlorio  acid  to  40  p.c 
aqueous  K>dium  nitnto  (Zeitech.  ^ysioL  Chem. 


1905, 46,  263).  This  leagent  can  be  mixed  with 
satorated  salt  solution  without  undergoing 
decomposition;  the  aliphatic  amino-carboxytic 
acids  (glycine,  &c.)  can  be  readily  decomposed 
by  it  in  a  current  of  carbon  dioxide,  and  the 
utrogen  evolved  is  freed  from  the  former  gas 
and  traces  of  oxides  of  nitrogen  by  passing  the 
mixed  gases  through  alkaune  permanganate 
solution.  Half  the  nitrogen  measured  m  the 
gas  burette  corresponds  with  that  originally 
present  in  the  amino-acid. 

In  the  case  of  the  aromatic  primary  amines, 
the  acid  solution  of  the  base  is  carefully  diaso- 
tised  at  0*  with  standard  sodium  nitrite ;  the 
end-point  is  reached  when  a  drop  of  the  solution 
gives  a  blue  c<dour  on  staron-iodide  paper. 
The  sodium  nitrite  solution  may  be  standardised 
with  either  potassium  permanmuiate,  sodium 
sulphanilate  (£m,<3«H4'SO^a,2HjO)  or  para- 
toluidine  (c/.  Green  and  Bideal,  Chem.  ^ews, 
1884,  49, 173  ;  Kinnicutt  and  Nef,  Amer.  Chem. 
J.  1886,  5,  388 ;  Zeitsch.  anaL  Oenu  1886,  25, 
223). 

Esiimation  of  imiruy-grou/pB  in  secondary 
amines.  A  weighed  quantity  of  the  substance 
IB  mixed  with  a  Imown  excess  of  acetic  anhydride, 
either  alone  or  diluted  with  dry  xylene  or 
dimethylaniline  (Bull.  Soc.  ohim.  1892,  [3] 
'7,  142 ;  Chem.  Zeit.  1893,  17,  27,  465).  After 
one  hour,  water  is  added  and  the  mixture  warmed 
under  a  reflux  apparatus,  so  that  no  anhydride 
is  lost  by  evaporation.  The  solution  is  then 
titrated  with  standard  barium  hydroxide  and 
phenolphthalefa  indicator.  The  amount  of 
acetic  acid  present  indicates  the  excess  of  acetic 
anhydride  left  Qi^er  from  the  aoetylation  of  the 
secondary  base. 

The  tertiary  amines  and  the  quaternary 
ammonium  sslts  do  not  give  the  reactions  of  the 
primary  and  secondary  amines,  but  the  total 
amount  of  basic  nitrogen  present  in  an  organic 
amine  can  frequently  be  asoerteined  by  the 
analysis  of  the  characteristic  salte  of  the  base. 
The  aurichlorides  and  platinichlorides  may 
frequently  be  employed  for  this  purpose,  as 
these  double  salts  on  ignition  leave  a  residue 
of  the  metal,  each  atomic  proportion  of  gold 
corresponding  to  one  basic  nitrogen  atom, 
while  a  similu  quantity  of  platinum  corresponds 
with  two  basic  nitrogen  atoms.  In  the  majority 
of  cases  these  double  salts  have  respectivebr  the 
general  formula,  BHCl,Auat  and  (RHa),Pta«, 
and  are  obtained  in  the  anhydrous  con- 
dition; yet,  in  certain  instances,  hydrated 
forms  are  known  and  sometimes  the  salts  them- 
selves have  an  anomalous  composition  not 
corresponding  with  the  general  formula). 
Evidence  obtained  in  this  way  should,  if  possible, 
be  supplemented  by  the  analysis  of  other  salts, 
and  for  this  purpose  the  ferrichlorides,  ohromates, 
oxalates,  tmocyanates,  ferrocyanides,  piorates, 
and  piorolonates  have  been  employed,  as  well 
as  the  commoner  nitrates,  sulphates,  and 
halide  salts. 

Gas  analysb. 

The  experimento  of  Gay-Lussao  esteblished 
long  ago  the  value,  from  a  soieatific  point  of 
view,  of  the  determination  of  the  volumetric 
composition  of  gases  and  the  producto  formed 
by  their  interaction ;  but  it  is  onlv  within  recent 
times  that  the  methods  of  gas  analysis  have  been 


ANALYSIS. 


290 


applied  to  any  great  extent  for  technical  pur- 
poses. The  value  of  such  determinations  is  now 
generally  recognised  on  account  of  the  informa- 
tioD  which  they  give  respecting  the  efficiency  of 
combustion,  the  progress  of  operations  in  wnicb 
gases  are  consumed  or  produced,  and  the  like. 

With  few  exceptions  the  volumetric  and  not 
the  gravimetric  composition  of  the  gas  is 
required*  and  the  measurements  are  essentially 
measurements  of  volumes.  The  gas  to  be  ex- 
amined is  confined  over  mercury  or  water  in  a 
suitable  measimnff  apparatus,  and  its  composi- 
tion is  determined  (1)  by  treatment  with  ap- 
propriate absorbing  reagents  and  measurement  of 
the  contraction  pr^ucM ;  (2)  by  exploding  with 
oxygen  or  hydrosen  and  measuring  the  contrac- 
tion ;  (3)  by  expfoding  with  oxyseo  or  hydrogen, 
measuring  the  contraction,  end  then  treating 
with  absorbing  reagents,  and  measuring  the 
second  contraction.  Sulphur  dioxide  and  some 
other  gases  soluble  in  water  are  estimated  by 
titration,  a  definite  volume  of  the  gas  beinff 
drawn  through  a  measured  quantity  of  a  standard 
solution,  the  excess  of  which  is  afterwards  de- 
termined. 

The  highly  refined  and  accurate  methods  of 
gas  analysis  employed  for  purposes  of  research 
are  of  bttle  vaiue  for  techmcal  jrarposes  on 
account  of  the  length  of  time  required  for  their 
execution.  Information  respecting  these  methods 
may  be  found  in  Bunsen's  Gasometrische 
Ulethoden,  2nd  ed.  1887 ;  Sutton's  Volumetric 
Analysis,  9th  ed.  1904 ;  Dittmar's  Exercises  in 
Quantitative  Analysis,  1887;  Hempel's  Gas- 
analytische  Methoden,  3rd  ed.  1900 ;  levers' 
Experimental  Study  of  Gases,  1901;  v.  also 
Thomas  (Ghem.  Soc.  Trans.  1879,  35,  213),  and 
Meyer  and  Seubert  (Ghem.  Soc.  Trans.  1884, 
45,  581).  In  this  article  only  those  methods 
will  be  described  which  are  available  for  technical 
purposes. 

jietuurements, — ^The  volume  T^ch  a  given 
mass  of  gas  occupies  depends  on  the  tempera- 
ture, the  pressure,  and  tne  proportion  of  mois- 
ture which  it  contains.  The  temperature  is  as- 
certained by  means  of  a  thermometer  attached 
to  or  suspended  near  to  the  measuring  vessel. 
Measurements  are  usually  made  under  atmo- 


spheric pressure,  and  this  is  determined  by  means 
oz  a  barometer  placed  in  the  room  in  which  the 
analysis  is  made.  The  sTphon  barometer  is  a 
convenient  form  of  instrument  for  the  purpose* 
and  should  stand  on  the  table  close  to  the  gas 
apparatus.  In  case  the  level  of  the  mercury  or 
water  in  the  measuring  tube  is  higher  than  that 
in  the  trough  or  the  attached  tube,  the  true  pres- 
sure upon  the  gas  is  given  by  the  height  of  the 
barometer  minus  the  difference  between  the 
mercury  level  inside  and  outside  the  tube.  If 
water  is  used,  the  height  of  the  water  column 
divided  by  13*6  gives  the  height  of  the  corre- 
sponding column  of  mercury  with  sufficient  ac- 
curacy. It  is  better  to  eliminate  this  correction 
by  acnusting  the  liquid  so  that  it  ia  at  the  same 
level  both  inside  and  outside  the  tube,  which  is 
easily  done. 

The  gas  must  be  either  perfectly  dry  or 
saturatea  with  moisture,  u  an  indennite 
quantity  of  water  vapour  is  preset,  accurate 
measurements  are  impossible.  It  is  more  cod- 
venient  to  measure  the  sas  when  moirt,  and 
'hence  if  the  gas  is  confined  over  mercury  a  few 
drops  of  water  are  introduced  when  the  tube  is 
filled  with  the  mercury  and  this  water  is  taken 
.up  by  the  gas.  Under  these  conditions  the  sur- 
rounding pressure  is  balanced  partly  by  the  gas 
and  partly  by  the  aqueous  vapour  which  it  con- 
tains, and  in  order  to  ascertain  the  pressure 
which  the  gas  itself  is  under,  the  tension  of 
aqueous  vapour  at  the  particular  temperature 
must  be  subtracted  from  the  heisht  of  the 
barometer.  The  formula  for  reducing  the 
volume  of  gas  to  the  standard  temperature  and 
pressure  (0*  and  760  mm.)  is : 


^^  (278  +  <)X760     ^^  ^* 


VX(B-/) 
(1-I-00080QCX760) 

in  which  V  is  the  actual  reading;  <,  the  tempera- 
ture ;  /,  the  tension  of  aqueous  vapour  at  the 
temperature^  t ;  and  B,  the  height  of  the  baro- 
meter. The  reduction  of  the  height  of  the 
barometer  to  0*  is  necessary  for  accurate  calcula- 
tion, but  may  usually  be  omitted.  The  following 
table,  abbreviated  from  Bunsen's  Gasometrische 
Methoden,  gives  the  value  of  1  +0<003d6<  for  the 
ordinary  range  of  temperature : — 


r» 

Number 

Log 

f> 

Number 

Log 

r» 

Number 

Log 

(f 

1-00000 

0-00000 

W 

1-04026 

0-01714 

21* 

1-07686 

0-03216 

I 

1-00366 

0-00159 

12 

1-04392 

0-01867 

22 

1-08052 

0-03363 

2 

1-00732 

000317 

13 

1-04758 

0-02019 

23 

1-08418 

0-03510 

3 

1-01098 

000474 

14 

1-05124 

0-02170 

24 

1-08784 

0-03656 

4 

1-01464 

0-00631 

15 

1-05490 

0-02321 

25 

1-09150 

0-03802 

5 

1-01830 

0-00788 

16 

1-05856 

0  02471 

26 

1-09516 

0-03948 

6 

102196 

000943 

17 

1-06222 

002621 

27 

1-09882 

0-04093 

7 

102562 

0-01099 

18 

1-06588 

002771 

28 

1-10248 

0-04237 

8 

1-02928 

001263 

19 

1-06954 

002921 

29 

1-10614 

0-04381 

9 

1-03294 

001407 

20 

1-07320 

003068 

30 

1-10980 

0-04524 

10 

1-03660 

0-01661 

When  the  estimations  are  made  rapidly,  and 
only  approximate  results  are  required,  the  cor- 
rections for  temperature  and  pressure  are 
omitted,  since  it  may  be  assumed  that  they 
remain  constant  during  the  analysis. 

The  following  plan,  described  by  Winkler, 


renders  the  use  of  the  barometer  and  thermo- 
meter unnecessary,  and  makes  the  calculation 
much  simpler.  It  is  an  adaplation  of  William- 
son and  Russell's  method  ox  always  measuring 
the  volume  of  the  gas  at  the  same  degree  of 
elasticity.    A  tube  about  1  metre  long,  closed 


300 


ANALYSIS. 


at  one  end  and  gradaatrd  to  120**  c.o.  in  tenths 
IB  moiatened  intcmaUy.  with  a  few  dro])6  of  water, 
and  merouiy  is  poured  in  in  snoh  quantity  that 
when  the  tube  is  inverted  the  mercury  stands 
somewhat  higher  than  100.  The  volume  which 
100  C.C.  of  air  measured  at  standard  temperature 
and  pressure  should  occupy  under  the  conditions 
described,  is  calculated  m>m  the  expression: 

V_(760-4-5)100X(278-f-g|       (7eO-i-6)100Xl-H)-008M<) 
278(B-/)  or  B-/ 

and  air  is  carefully  introduced  into  the  tube  until, 
when  the  mercury  is  at  the  same  level  inside 
and  outside  the  tube,  it  stands  exactly  at  the 
calculated  volume.  The  tube  now  contains  a 
quantity  of  gas  saturated  with  moisture,  which, 
under  standud  conditions,  would  occupy  100  c.c, 
but  its  actual  volume  varies  in  the  same  ratio  as 
the  volume  of  gas  to  be  measured.  The  two 
tubes  are  allowed  to  stand  side  by  side,  and 
when  the  levels  have  been  properly  adjusted  in 
each  case  the  volume  of  the  sas  to  be  measured 
and  the  volume  of  the  air  in  the  comparison  tube 
are  read  off.  The  volume  (under  standard 
conditions)  of  the  gas  under  examination  is 
obtained  by  the  proportion 

in  which  V  is  the  actual  volume  of  air  in  the 
comparison-tube ;  Vq,  its  volume  under  standard 
conditions,  which  is  always  100;  Vi',  the 
observed  volume  of  the  gas  to  be  measured; 
and  Vq',  its  volume  under  ^andard  conditions. 

During  the  operations  the  temperature 
should  be  kept  as  constant  as  possible,  and  the 
readmgs  should  be  taken  rapidly,  otherwise  the 
proximity  of  the  body  will  cause  variations  in 
the  temperature  of  the  gas.  It  is  an  advantage 
to  have  the  measuring  tube  surrounded  by  a 
wider  tube  which  is  filled  with  water.  The  most 
accurate  method  is  to  take  the  readings  through 
a  carefully  levelled  telescope  (a  cathetometer)  at 
a  distance  of  about  five  or  six  feet.  This  also 
avoids  parallax.  The  measuring  tube  must  be 
kept  vertical^  and  when  water  is  the  confining 
liquid,  sufficient  time  must  be  nven  for  the 
liquid  to  run  down  the  sides  of  the  tube.  Not 
unfrequently  this  requires  several  minutes. 

Beagenis. 

All  liquid  reagents  should  be  saturated  with 
the  gaaes  which  they  do  not  absorb  chemically. 
It  is  desirable  that  the  tensions  of  these  gases 
in  the  liquids  should  be  approximately  equal  to 
their  tensions  in  the  gases  which  are  to  be 
analysed,  in  order  to  avoid  exchaiu^  between 
the  gas  and  the  abeorbinff  liquid.  This  is  beet 
secured  by  going  througn  the  process  two  or 
three  times  without  wmlriTig  measurements, 
whenever  the  pipettes  have  been  freshly  filled. 
Liquids  used  for  the  analysis  of,  say,  flue  gases, 
should  not  be  used  for  gases  of  a  diffeient  cha- 
racter, t.e.  which  contain  the  constituents  in 
very  different  proportions. 

Bromine  tonter  is  used  for  absorbing  defines. 
It  should  be  well  saturated  with  bromine  and 
kept  in  the  dark. 

Cwprcua  chloride  is  made  by  dissolving  60 
^rams  of  cupric  oxide  in  hydrochloric  acid,  add- 
ing 00  grams  of  copper,  and  boiling  for  some 
time  with  as  little  exposure  to  air  as  possible. 
Jlie  solution  is  then  diluted  to  1000  c.c.  with 
^-^hloric  acid  of  Rp.gr.  1*12.  and  allowed  to 


remain  in  contact  with  metallic  copper  in  a  closed 
vessel  until  the  solution  becomes  odourless. 
This  solution  attacks  mercury  rapidly. 

Cuprcathamtnonium  chloride^  obtained  by 
dissolving  cuprous  chloride  in  ammonia,  does 
not  attack  mercury. 

The  stock  solution  is  made  by  dissolving 
200  grams  of  cuprous  chloride  and  260  grams  of 
ammonium  chloride  in  760  c.c.  of  water ;  it  is 
kept  in  stoppered  bottles,  and,  when  requured, 
mixed  with  one-third  its  volume  of  ammonia 
solution  (8p.gr.  0*91). 

Hydrogen  is  obtained  by  the  action  of  dilute 
sulphuric  acid  on  pure  zinc.  The  eranulated 
zinc  may  be  placed  m  a  small  bottle  fitted  with 
a  capillary  ddiverr  tube,  which  can  be  doeed  by 
a  tap  or  pinch-cock.  The  bottle  has  a  tubulus  at 
the  Dottom,  and  is  connected  b^  a  caoutchouc 
tube  with  a  similar  bottle  containing  dilute  sul- 
phuric acid.  The  latter  bottle  is  raised  so  that 
the  acid  runs  on  the  zinc,  and  the  action  is 
allowed  to  proceed  until  the  air  is  oompletdy 
expelled  from  the  first  bottle.  The  tap  is  then 
dosed,  and  the  acid  is  driven  back  into  the  second 
bottle  by  the  pressure  of  the  hydrogen.  It  is 
advisable  to  keep  the  second  bottle  at  a  slightly 
higher  level  than  the  fixst,  to  avoid  any  chance 
of  air  leaking  in.  One  of  Uempd's  tubulated 
absorption  bulbs  answers  admirably  (Fig.  41). 
The  zmc  is  attached  to  a  cork,  which  is  inserted 
in  the  tubulus  of  the  first  bulb,  and  the  acid  is 
introduced.  When  all  air  is  expelled,  the  capil- 
lary tube  is  dosed,  and  the  acid  is  driven  up  into 
the  second  bulb,  so  that  the  pipette  is  alwayB 
charged  with  hydrogen  under  pressure. 

Oxygen  is  obtaineid  in  a  pure  state  by  heating 
potassium  chloride  toithotU  manganese  dioxide. 
The  powdered  chlorate  is  contamed  in  a  glass 
bulb,  the  neck  of  which  is  drawn  out  to  form  a 
narrow  delivery  tube. 

Phoephorua  is  employed  in  the  form  of  narrow 
sticks,  which  are  made  by  mdting  it  under  warm 
water  and  drawing  it  up  into  narrow  ^lass  tubes. 
The  upper  ends  of  the  tubes  are  dosed  by  the 
finger,  and  they  are  plun^^ed  into  cold  water, 
when  the  phosphorus  sohdifies.  It  may  abo 
be  used  in  a  granular  form,  obtained  by  shaking 
the  phosphorus  vigoroudy  with  warm  water  in  • 
well-dosed  flask  until  it  solidifies. 

Caustic  potash  {or  eoda)  for  Orsat's  apparatus 
18  dissolved  in  three  parts  of  water,  and  the  solu- 
tion kept  in  well-stoppered  bottles.  Hempd 
uses  a  solution  of  caustic  potash  in  two  parts  of 
water,  which  will  absorb  forty  times  its  volume 
of  carbon  dioxide.  It  may,  however,  be  used 
somewhat  more  dilute,  and  is  then  less  liable  to 
attack  the  glass. 

PwogcMol  is  kept  in  the  solid  state,  and  only 
dissolved  immediately  before  being  used.  Orsat 
recommends  a  solution  of  26  grams  of  pyrogallol 
in  a  small  quantity  of  hot  water,  mixed  with 
160  C.C.  of  a  solution  of  1  part  of  caustic  soda  in 
3  parts  of  water.  Hempd  uses  a  mixture  ol 
26  cc.  of  a  20  p.c.  solution  of  pyrogallol  with 
76  cc.  of  33*3  p.c.  caustic  potash  solution. 
This  quantity  will  absorb  200  cc.  of  oinrgen. 

Shipley  (J.  Amer.  Chem.  Soc.  1916,  38, 1687) 
found  the  most  effective  solution  was  prepared 
by  addii^  40  c.o.  of  water  to  100  gnuns  pyrogalld 
and  adding  100  cc  of  49  p.o.  s^um  hydroxide 
solution.  No  carbon  monoxide  is  evolved  from 
a  solution  of  this  strength. 


Andeiaon  (J.  lad.  and  Bug.  Ch«in.  1S15.  7. 
S7)  recomnunds  a  aoli  '*         '  " 
g»llal  in  lOO  ca  potaa 
ofap.sr.  rSS. 

SiUpharie  atid  at  ip.gi.  I'M  is  used  m  a 
diyiiig  agent  and  tor  Uut  abamption  of  nitiagan 
oades.  Aoid  of  the  mne  BtTenstli  miied  with 
M)  mnch  Bnlphmie  aohjdhde  tbat  it  remain  i 
fiqmd  at  the  ordinarj  tunperatiini  but  solidifiea 
if  cooled,  is  naed  for  abMrbing  ethylene  and 
other  l^drocarboui. 

Water,  which  is  very  largetv  used  tor  con- 
fining the  eases,  ahonld  be  well  satiuated  with 
air,  but  uotild  not  oootain  carbon  dioxide. 
DistiUed  watei  U  preferable,  bat  any  potable 
water  of  good  quality  may  be  osed. 

Stam&rd  ntvtioru  nsed  in  the  estimation  of 
gases  b;  titiatioD  are  knottn  u  normal  gas 
ttMioiu  when  ti>ey  are  of  such  atiengtli  that 
I  0.0.  c^  the  Btdutum  is  eqniralent  to  1  o-c  of 
tho  gu  nndsc  standard  ooodttion*.  A  nomiHl 
gas  scdntkn  ot  iodine  fo(  the  estimation  ot 
aolrttnr  dioxide  woold  oontun  11-333  grams  of 

■  Ime  per  litrt,  am '  " 

id  in  eonJDDction 
_ — ^t  stnmgui. 

In  many  nsnrr  it  is  the  weight  of  the  absorbed 
constitnent  per  onbio  metre  or  oubio  foot  ot  gas 
that  is  required,  and  the  ordinary  itandard 
•olutionB  may  be  used. 

MdJuxkof 

AmmoDlt,  by 

Bounw,  by  abeotption  in  fuming  nitriikaoid 
boiling  at  96r,  the  nitKwen  oiidee  bein^  then 
ramoTed  by  oanBtio  potai£.  Fuming  nitno  acid 
al»i  absorbs  osibon  dioxide  and  carbon  mon- 
oxide. Like  the  olefines,  benseae  i»  absorbed 
by  fnming  salpbniia  aoid  and  by  bromine  wat«r, 
and  in  fact  no  absorption  method  is  at  present 
known  by  means  of  which  beniene  and  the 
olefines  can  be  eeparated  (Ber.  1S8S,  21,  3131). 

Cukon  dloiUe,  by  absorption  in  potassium 
or  Bodinm  hydroxide. 


n  bydrocblorio 
aoid  or  ammonia.*  It  seem*  {Ber.  IS8T,  20, 
27M)  that  tlieee  solntionB  are  liable  to  give  oS 
part  of  the  dissolved  carbon  monoxide,  espeoiatly 
after  they  have  been  used  repeatedly,  The 
error  is  lew  with  the  ammoniacal  eolation,  and  is 
reduced  it  the  solotion  remains  in  contact  with 
the  gaa  foe  some  time.  The  cnproiia  chloride 
•(datum  iboold  always  be  tolerably  fresh,  and 
should  be  K^nnted  wiUi  hydrocen,  nitrogen, 
and  the  otlier  gasea  which  osasjly  occur  with 
eubimia  oxide  {Ber.  1888,  21,  898).  It  the 
amount  of  oarbon  monoxide  is  small,  it  should 
be  converted  by  oombiution  {v.  Hydrogtn)  into 
carbon  dioxide,  which  is  afterwords  absorbed 
by  oauatio  potash.  If  the  amount  of  oarbon 
monoxide  is  large,  the  greater  part  may  be  ab- 
•(wbed  by  ouptms  chloride,  ana  the  remainder 
removed  Dy  oombustiou  and  absorption. 

The  eetimatioQ  of  small  quantities  <A  carbon 
monoxide  in  air  or  other  oomparativel^  inert 
gases  can  be  efiected  by  passing  the  dried  gaa 
over  solid  iodine  pentoxide.  At  tempeiatures 
varying  itom  iO°-lSO*  the  following  reaction 
oooun:  I,0,+6C0=BC0,+1,.  Ei^er  of  Oie 
volatile  products  can  be  estimated  :  the  iodine 
volumetxioally    by   standard    thiosulphate, 


gravimetrically  by  absorpUon  in  a  waigliBd  tube 


_.  barium  hydroxide.     Below  6 

nydrooarbon    exoept    acetylene    redaoea    iodic 
anhydride.     At    higher    temperatures    severat 


carbon  monoxide  by  the  iodine  pentoxide.  The 
process  is  applicable  to  air  containing  Mie  part 
of  oarbon  monoxide  in  30,000,  and  n  ueea  for 
ectimaling  the  monoxide  occluded  in  steel 
(Uautier,  Oompk.  ruid.  1808,  120,  BTl,  1209; 
Jean,  ibid.  1002,  13C,  746  ;  J.  Amer.  Cbem.  Soo. 
leoO,  22,  14 ;  1007,  29,  1580 ;  Ann.  Chiin.  anal. 
1910.  15,  1). 

Hydrogen  is  ooaverted  mto  water  by  combus- 
tion with  air  or  oxygen,  and  the  volone  of  the 
hydrogen  is  refveeented  by  two-thirda  of  the  con- 
traction  consequent  upon  oombujtion.  If  the 
gas  is  confined  over  metonry,  an  excess  of  pare 
oxygen  is  introduoed,  the  vcjooie  read  off,  and 
the  prceauro  on  the  gas  reduced  ooosiderably 
below  atmoapherio  pressure  by  lowering  the 
mercury  in  the  level  tube.  The  lower  end  of  the 
explosion   tube  is  closed,   and   combination   is 


bustion,  and  it  is  much  more  convenient  to  pass 
the  combustible  mixture  over  gently  heated 
spongy  palladium.  This  is  prepued  by  dis- 
solving about  two  grams  of  palladium  chloride 
in  a  small  quantity  of  water,  adding   a  small 

Joantity  of  a  saturated  solution  of  sodium 
irmate  and  sodium  carbonate  until  the  re- 
action is  alkaline.  About  1  gram  of  long 
and  very  soft  asbestos  fibres  is  mtroduoed,  ana 
the  pasty  mass  is  dried  at  a  gentle  heat.  In  this 
way  the  asbeetoe  is  obtained  covered  with  very 


finclvdivided  pathldinm.    Aftrr  beiu  completely 
dried  at  100",  it  is  carefully  washed  with  water 


302 


ANALYSIS. 


to  remove  soluble  salts  and  again  dried.  Some 
of  the  fibres  are  .moistened  and  twisted  into  a 
thread  abont  1  cm.  long,  which  is  then  intro- 
duced into  the  middle  of  a  stout  capillary  tube,  i, 
about  16  om«  long  and  1  mm.  internal  diameter, 
and  this  tube  is  bent  at  a  right  angle  at  each  end. 
or  in  any  other  wa^  convenient  for  its  attach- 
ment to  the  measurmg  apparatus  containing  the 
g^  One  end  of  the  capillary  is  in  communica^ 
tion  with  the  graduated  tube,  ▲,  and  the  other 
with  a  bulb  pipette,  o,  filled  completely  vriih. 
water,  into  which  the  gas  is  passed.  A  small  gas 
or  spirit-lamp  flame  is  arranged  to  heat  that  part 
of  the  capillary  which  contains  the  asbestos. 
When  the  other  gases  have  been  estimated,  the 
miztoze  of  hydrogen  and  nitrogen  which  remain 
is  mixed  wiUi  air  by  lowering  the  level-vessel 
nntQ  the  pressure  is  sufficiently  reduced,  and 
then  puttmg  the  measuring  tube  in  com- 
munication with  the  air.  The  stop-oook  is  then 
closed,  the  asbestos  very  gently  heated,  and  the 
ffas  passed  slo^dy  through  the  capillary  into  the 
Dulb  and  back  again  throe  or  four  times.  When 
combustion  is  complete,  the  volume  of  the 
residual  gas  is  measured. 

This  method  may  be  employed  in  estimating 
hydrog^en  in  the  presence  of  methane,  since  the 
latter  is  not  burnt  under  these  conditions,  pro- 
viding that  the  temperature  does  not  exceed 
600*  (J.  Soo.  Caiem.  Ind.  1903, 22,  925 ;  1906, 
24,  1202 ;  Zeitsoh.  angew.  Ghem.  1903, 16,  696). 

The^  palladinised  asbestos  can  be  used  in 
promoting  the  combustion  of  carbon  monoxide. 

Drehschmidt  (Ber.  1886,  21,  3246)  prefers  a 
platinum  tube  20  cm.  long  and  2  mm.  thick,  with 
a  bore  0*7  mm.  diameter.  The  bore  is  almost 
closed  by  the  insertion  of  a  palladium  wire  ex- 
tending through  the  whole  length  of  the  tube. 
The  tupe  is  attached  \o  a  burette  and  an  absorp- 
tion pipette  in  the  same  manner  as  the  g^aaa 
tube;  6  to  6  cm.  are  heated  to  redness  by  means 
of  a  gas  flame,  and  the  gas  is  passed  backwards 
and  forwards  until  there  is  no  lurther  alteration 
of  volume.  No  explosions  occur  even  with 
mixtures  of  hydrogen  and  oxygen  containing 
onlya  slight  excess  of  the  latter. 

jEempSl  has  applied  the  well-known  absorp- 
tion of  hydrogen  by  palladium  to  the  estimation 
of  this  gas.  Pure  palladium  is  indifferent 
towards  hydrogen  in  the  presence,  of  methane 
and  nitron,  but  when  it  contains  a  little  palla- 
dious  oxide  combustion  of  some  of  the  hydrogen 
occurs,  and  the  heat  generated  ensures  the 
absorption  of  the  remainder.  Palladium  sponge 
is  heated  and  allowed  to  cool  slowly  so  that  it 
becomes  super fioiaUy  oxidised.  A  U-tube  of 
4  mm.  internal  diameter  and  20  cm.  total  length 
is  charged  with  4  grams  of  this  oxidised  sponge 
and  maintained  at  90*-100*  by  immersion  in  a 
beaker  of  hot  water;  this  tube  is  interposed 
between  the  gas  burette  and  a  pipette  filled  with 
water.  The  absorption  is  effected  by  siphoning 
the  gas  backwards  and  forwards  through  the 
palladium  sponge. 

Hydrogen  omoride,  by  titration. 

Hydrogen  sulphide,  by  titration. 

Hydroeurbons  other  than  defines  are  esti- 
mated by  combustion,  preferably  with  oxygen 
over  mercury  under  reduced  pressure.  Acety- 
lene and  benzene  may  be  burnt  over  palladium, 
but  require  a  somewhat  hich  temperature. 
Methane  cannot  be  burnt  in  uus  way  even  in 


presence  of  hvdrogcn.  The  combustion  of  this 
gas  is  effected  by  mixing  it  with  a  considerable 
quantity  of  air  and  aspirating  the  mixture 
uirouffh  a  short  tube  containing  cupric  oxide 
heated  to^rednessin  a  smaU  combustion  furnace, 
the  carbon  dioxide  which  is  produced  beins 
absorbed  in  standard  baryta  solution,  which 
is  afterwards  titrated  with  standard  oxalic  acid. 

Drehschmidt  finds  (Ber.  1888,  21,  3249)  that 
a  mixture  of  methane  and  oxygen  can  r^dily  be 
burnt  in  a  platinum  tube,  as  arove,  tf  tro  latter 
is  heated  to  bright  redness.  The  contraction 
is  observed,  and  the  carbon  dioxide  formed  is 
removed  and  the  volume  again  measured. 

Httrie  oilit  is  converted  into  peroxide  by 
admixture  with  oxygen,  and  the  peroxide  to 
absorbed  by  caustic  potash,  the  excess  of  orvgen 
bein^  af  terwardsabeorbed  by  alkaline  pyrogaUate. 
Nitno  oxide  ma^  also  be  absorbed  by  a  con- 
centrated solution  of  ferrous  sulphate,  but 
this  method  does  not  give  such  satisfactory 
results. 

introg«n  peroxide  and  nitrons  anhydrMs,  by 
titration ;  by  absorption  with  sulphuric  add  of 
sp-ffr.  1*84;  or,  in  absence  of  carbon  dioxide 
and  other  absorbable  gases,  by  absorption  with 
caustic  potash. 

Oleflnes,  by  absorption  with  fuminff  sulphnrio 
acid,  acid  vapours  oein^  removed  by  canstio 
potash;  or  by  absorption  in  bromine  water, 
bromine  vapours  being  afterwards  removed  by 
caustic  potash. 

Oxygtn,  by  absorption  with  alkaline  pyro 
gallate.  If  the  oxygen  is  present  in  greater  pro 
portion  than  20  p.c  a  small  quantity  of  os^Don 
I  monoxide  is  evolved  from  the  pyrogalldl  during 
absorption,  and  hence  the  results  are  slightly  too 
low.  After  treatment  with  pyrogallol  the  eas 
may  be  passed  into  the  cuprous  chloride  biube 
^in  order  to  remove  any  carbon  monoxide  that 
may  have  been  formed.  Usually,  however,  this 
error  has  no  material  influence  on  the  results. 
Oxvgen  may  also  be  absorbed  by  phosphorus, 
ana  this  has  the  advantage  that  the  presenoe  of 
carbon  dioxide  is  without  influence  on  the  result. 
The  temperature,  however,  must  not  be  below 
18®,  and  the  absorption  is  prevented  by  the 
presence  of  ammonia,  oleflnes,  and  other  hydro- 
carbons, alcohol,  ko. 

Sodium  hydrosulphite  has  been  recommended 
as  an  absorbent  for  oxygen,  the  reaction 

NaaS,04+H.O+Oa2NaHSO, 

taking  place  readily  at  low  or  high  temperatures. 
The  solution  contains  60  grams  of  the  salt  and 
40  C.C.  of  sodium  hydroxide  (6 :  7)  in  260  cc.  of 
water,  and  is  used  in  a  pipette  filled  with  rolls  of 
iron-wire  gauze  (Ber.  1906,  39,  2069). 

Oxygen  may  also  be  estimated  by  combustion 
with  hydrogen,  either  explosively  by  the  spark 
or  over  palladium-asbestos.  The  hydroj^en 
should  be  evolved  from  commercial '  pure '  zmo 
and  pure  dilute  sulphuric  acid,  or  in  special  cases 
from  magnesium  and  sulphuric  acid.  One-third 
of  the  contraction  consequent  upon  combustion 
gives  the  volume  of  the  oxygen. 

Snlphnr  dioxide,  by  titration. 

In  the  ordinary  gases  from  flues,  generators, 
&c.,  the  constituents  are  estimated  in  the  foUow- 
ing  order :  CSarbon  dioxide,  oleflnes  and  bensene, 
oxygen,  carbon  monoxide,  hydrogen,  methane, 
nitrogen  (as  residue  or  by  difference). 


ANALYSIS. 


90S 


II  acid  yapoan  are  present  together  with  one 
or  more  of  the  above  gases,  the  order  of  aboorp- 
tion*  &C.,  must  be  determined  by  ciroamstanoes. 

Apparaius  and  tnanipuUUumt 

CoBeeting  mmfUa. — The  gas  to  be  analysed 
18  usoaUy  drawn  nom  the  flue,  chamber,  &o.,  by 
aspirating  it  through  elass  tabee,  which  may  m 
termed  oondnctins  tubes.  When  the  tempera- 
ture is  high,  porcdain  tubek  may  be  used ;  or  if 
the  gas  has  no  acid  properties,  iron  tubes  can  be 
employed.  When  samples  are  constantly  taken 
from  the  same  flue,  &c.,  it  is  convenient  to  have 
a  short  piece  of  porcelain  or  iron  pipe  cemented 
into  the  wall  ana  closed  at  the  outer  end  with  a 
plug,  which  is  readily  removed  when  the  sample 
IS  taken.  In  cases  where  the  gases  are  originaJly 
at  a  high  temperature  and  possibly  in  a  state  of 
partial  dissociation,  it  is  important  to  draw  the 
sample  slowly  through  a  somewhat  long  tube  in 
order  that  the  gas  may  cool  slowly,  since  rapid 
cooling  of  the  gases  may  leave  them  in  a  partially 
dissociated  condition  and  thus  lead  to  erroneous 
results. 

The  sample  may  be  conveniently  collected  in 
the  measuring  apparatus  itself ;  but  where  this 
is  not  possible,  a  cylindrical  gUss  tube  A^  drawn 
out  at  the  upper  end  and  connected  witii  a  stop- 
cook  and  capillary  tube,  and 
drawn  out  at  the  lower  end  and 
connected  by  caoutchouc  tubing 
with  a  similar  tube  B,  open  at 
the  top,  makes  a  convenient 
sampler.  The  collecting  tube 
may  with  advantage  be  pro- 
vided with  a  stop-cock  at  the 
bottom.  The  vessel  a  is  com- 
pletely  filled  with  water  or  mer- 
cury by  raising  B  to  a  higher 
level,  and  the  upper  stop-cock 
is  closed.  The  capillaiy  tube  is 
connected  with  the  conductinff 
tube,  and  the  vessel  B  is  l<^werea 
so  that  when  the  stop-cock  is 
slowly  opened  the  gas  is  drawn 
into  A,  and  the  water  or  mercury 
collects  in  B.  When  a  is  filled  tbie 
stop-cocks  are  dosed.  The  gas 
is  readily  transfened  from  a  to  the  measuring 
vessel  by  raising  b  and  carefully  opening  the 
stop-cooK. 

in  all  cases  the  air  in  the  conducting  tube 
must  be  expelled,  and  this  is  done  by  placing  a 
T-tube  between  the  end  of  the  tube  and  the 
collecting  vessel.  This  T-pieoe  is  connected 
with  an  aspirator,  and  the  tube  is  filled  with  the 
gas  before  the  stop-cock  of  the  collecting  vessel  is 
opened.  When  the  ooUeoting  vessel  is  provided 
with  a  three-way  cock,  the  aspirator  may  be 
connected  directly  with  the  latter.  Various 
forms  of  aspirator  may  be  used.  When  the 
volume  of  ^  to  be  aspirated  is  small  {t,g,  in 
removing  air  from  the  conducting  tube),  a  small 
globular  indiarubber  aspirating  pump  is  very 
convenient.  For  larger  quantities  of  gas,  glass 
bottles  with  a  tubulus  or  stop-cock  at  the  bc^m 
and  a  tube  or  stop-cock  at  the  top,  or  similar 
vessels  of  sheet  amc,  may  be  used  ( Figs.  36  and  37). 
They  are  filled  with  water,  the  upper  tube  being 
connected  with  the  tube  which  passes  into  the 
flue,  and  the  water  is  allowed  to  flow  from  the  tap 
at  the  bottom.    The  volume  of  gas  aspirated  is 


determined  by  measuring  the  volume  of  water 
which  flows  from  the  aspirator,  and  correcting 


Fio.  30. 


Fio.  37. 


this  volume  for  temperature,  &o.,  in  the  usual 

Way(v.  ASFIBATOB). 

When  aspiration  is  to  be  continued  for  a  long 
time,  one  of  the  various  forms  of  water  pump 
may  be  used.    The  volume  of  air  aspirated  m  a 

g'ven  time  with  a  given  pressure  of  water  may 
)  determined  once  for  all  by  direct  measure- 
ment, or  a  small  sas  meter  may  oe  placed  between 
the  pump  and  uie  vessel  into  which  the  gas  is 
passed. 

If  the  gas  has  to  be  kept  for  some  time  before 
analysis,  or  if  it  has  to  be  transported  from  one 
place  to  another,  it  may  be  collected  in  glass 
tubes  which  have  previously  been  drawn  out  at 
each  end.  As  soon  as  the  tubes  are  fuU,  the  ends 
are  closed  by  stoppers  of  indiarubbw  tubing  and 
elass  rod,  or  are  nermetically  sealed  b^  fusion. 
If  the  quantity  of  gas  is  large,  cylindrical  zinc 
vessels  with  conical  ends  closed  £y  indiarubber 
corks  answer  very  welL 

(For  other  forms  of  gas-samplers,  r.  J.  Soc. 
Chem.  Ind.  1889,  8,  176 ;    1903,  22,  190.) 

Estimaiions  by  titration, — ^A  measured  quan- 
tity of  the  appropriate  standard  solution  is 
placed  in  a  flask  or  a  Woulfl's  bottle  fitted  with 
two  tubes,  one  of  which  dips  into  the  liquid  and 
is  connected  with  the  tube  placed  in  the  flue, 
&a,  whilst  the  other  ends  just  below  the  cork 
and  is  connected  with  an  aspirator.  After 
aspiration  has  been  continued  tor  a  sufficient 
length  of  time,  the  excess  of  reasent  is  deter- 
niined  by  titration.  The  volume  of  gas  aspirated 
is  determined  by  the  volume  of  water  which  has 
run  from  the  aspirator  or  by  means  of  a  gauge 
attached  to  the  aspirator.  This  volume  of 
water,  however,  represents  a  volume  of  gas 
saturated  with  moisture  and  at  a  temperature 
and  pressure  which  must  be  determined  by 
means  of  a  thermometer  attached  to  the  aspirator 
and  a  barometer  in  close  proximity ;  the  volume 
under  standard  conditions  is  calculated  in  the 
usual  way.  In  calculating  the  percentage  com- 
position of  the  gas,  it  must  be  borne  in  mmd  that 
the  original  volume  of  the  gas  was  the  sum  of  the 
volumes  of  the  absorbed  constituent  and  the 
volume  which  has  passed  into  the  aspirator. 

If  F,  is  the  volume  of  the  absorbed  gas,  and 
F,  the  volume  which  has  passed  into  the  aspira- 
tor,   both    under    Standard    conditions,   then 

100  X  Vj  *     *  17  u        1 

y    V\T    "■  V^^  otiDt,  of  F|  by  volume. 

This  method  may  be  applied  in  the  estimation 
of — 

Ammonia,  by  absorption  in  sulphuric  acid 
and  titration  with  alkalL 

Carbon    dioxide  (in  small    quantities),  b^ 


304 

abBOrpUon  in  itandud    b*ryta   solution    uid 

titntioD  with  oiAlio  acid. 

CUorina,  by  abaorption  in  a.ttuidud  Mlti- 
tion  ol  UBeniotu  oxide  in  sodium  oarbonsM. 
and  nbaeqaent  titration  with  iodins  after 
saturating  with  carbon  dioxide. 

Wlien  hydioohlorio  acid  and  dhlorins  ocotu 
togethor,  the  latter  is  determined  soparately  in 
one  quantity,  and  a  seoond  quantit;  is  absorbed 
in  the  solution  of  araenions  oxide  in  sodjnm 
carboQat«  free  ftom  chlorine,  and  the  total 
.•tilnrina  u  determined  by  titcation  with  silTer 
nitiate,  nsing  Volhard's  thioayanate  method. 
In  oaknla^g  the  praoentage  oomposition,  it  is 
important  to  remenibK  thift  1  toL  of  chlmine 
pcodaocs  2  toIs.  of  kydnxdiloria  a«id. 

HydnehtelB  mU,  by  abaonition  in  sodium 
carbonate  and  titration  with  ulver  nitaate,  or, 
in  absence  of  carbon  dioxide  and  other  acida. 
By  absorption  in   standard  caostio  potash 
soda,  and^bseqnent  titration  with  an  aoid. 

Hfdngan  ntlphUe,  by  absorption  in  standi 
iodine  aod  tikation  with  thiosulphate ;   or  by 
alMOrption  in  Ijtomine  water  and  graTimetrio 
estimation  as  barinm  sulphate. 

Mliiogan  OXUn.  by  alisorption  in  acidified 
permanganate  solution  of  definite  stren^h,  the 
passed  nntil  the  solution  is  just  de- 

This  method  gives  the  amonnt  of 

I   oxides    in    terms   of    their   reducing 

Snlphnr  dioxide,  by  absorption  in  standard 
iodine  solution  and  titmtioa  with  thiosolphate, 
or  by  absorption  in  bromine  water  and  graTi- 
metrio estimation  as  barium  sulphate.  The 
latter  [lan  may  be  adopt«d  when  the  proportion 
of  nilphor  dioxide  is  very  small  and  a  large 
Tolome  of  gas  must  be  aspirated. 

Mamrtng  a»d  oiwrptton  ajiparattu. — Only 
those  forms  which  tiaie  come  into  general  use 
and  are  of  wide  applicalnlity  will  be  described 
here.  Descriptions  of  the  numerous  other 
modifications  will  lie. found  in  Winkler's  Chem. 
Untera.  der  Industrie-Gase ;  Winkler  and 
Lunge's  Teclmical  Gas  Analysis ;  and  in  Zeitaoh. 
an^  Oiem. 

An  extremely  conTenient  device  whiob  is 
applied  to  almost  all  the  forms  of  apparatus  is 
the  ttiree-way  stop-cook.     Tliis   has   the   usual 


Fio.  38. 


traMverse  bore,  but  the  plug  itself  is  elongated 
in  the  form  of  a  tube,  the  bOTe  of  which  is  con- 
tinued in  a  Durred  direction  through  tlie  plug 
and  opens  at  the  side  in  the  same  plnne,  but 
in  a  direction  at  riaht  angles  to  the  transverae 
bore.  By  means  of  this  tap  two  tubes  can  be 
made  to  oommnnicate   with   one  another,   or 


burette  consists  of  aoyliudrioalbulbtc  .„ 

at  one  end  in  a  oapillai^  tube  and  at  the  other 
in  a  narrow  tube  of  noiform  bore  graduated  in 
tenths  of  a  oubic  centimetre.  The  total  capacity 
of  the  tube  from  the  cero  to  the  capillary  is  lOO 
aa,  and  the  lower  end  of  the  tube  is  oonneot«d 
by  caoutchouc  tubing  with  a  '  level-botUe,*  the 


with  water  at  a  constant  temperature.  The 
capillary  from  the  upper  end  of  the  measuring 
tube  it  carried  horuontally  along  a  wooden 
snpport.  Other  oapillary  tube*  provided  with 
stop-oocks  are  fused  into  it  at  right  angles  and 
communicata  by  means  of  very  short  Isogths 
of  stont  iudiarnDba  tubing  witA  the  absorption 
pipettea,  eaeh  of  which  oontisla  erf  a  pair  ol 
somewhat  large  oylindrieal  bulos  oommnnioating 
at  the  bottom  by  a  ourred  tube.    Tbe  bulbs 


OT»at'»  apparatvt.—The  measuring  tube  or 


nearest  tbe  oapillary  tubes  are  fitted  with  short 
lengths  of  glass  tulung  so  that  a  large  surface  of 
the  reagent  may  be  exposed,  and  the  other  bulbs 
receive  the  liquids  when  they  are  driven  out 
from  the  first  bulba  by  the  gaa.  Any  number 
of  bnlbe  Dan,  of  course,  be  attached  to  the  main 
oapilluy,  and  at  the  end  of  it  there  is  a  three- 
way  tap  communicating  with  the  upirating  tube 
or  with  the  air. 

The  three  absorption  pipettes  indioated  in 
Fis.  39  are  geoerally  filled  respectively  with 
sohitiona  of  oaustic  potash,  alkaline  pvrogaUate, 
and  anprous  chloride,  and  serve  for  llie  eatima- 
tion  of  oarbon  ilioxide,  ox^en,  and  carbon 
monoxide. 

The  burette  is  filled  with  wato  b^  placing 
the  liquid  in  the  level-bottle  and  raising  the 
latter,  and  the  stopoocks  are  thea  closed.  The 
ahsorption  bulbs  are  rather  inot«  than  half  SUed 
uith  the  liquid  reagents,  and  by  opsoing  the 
stop-cocks  snd  fdadng  the  level-bottle  below  the 
apparatus  the  liquids  are  drawn  up  so  as  to  fill 
completely  the  bulbs  connected  with  the  e>t|Hl- 
laries.    The  stop-cocka  are  then  oloeod. 

The  burette  is  filled  with  water  up  to  1^ 
capillary  tube  by  raising  the  level-bottle,  and  the 


br  end  of  the  capill>ry  tabe  ii  ronneoted  with 
tha  tube  tlocg  iriuch  the  gai  is  to  be  oonducted. 
The  lower  end  of  the  three-way  Utp  i»  connected 
with  m  iDdi&mbbeT  upirator,  and  the  air  ie 
removed  from  the  oondncting  tube  b;  aspirating 
the  gu  thioogh  it.  The  tevsl-bottle  is  then 
loweredi,  the  tap  is  tnmed  throngh  OO*.  and 
the  saa  is  drawn  into  the  burette.  When  a 
miffioHnit  T<dnme  haa  •nt«Ted,  the  tap  ii  closed, 
the  level*  inside  and  outaide  the  bniette  are 
•diluted  hj  laising  the  level-bottle,  and  the 
volume  of  the  gu  ie  read  off  as  soon  u  the 
temperature  ii  oonntaut.  If  it  is  deeired  to 
operate  npon  exactly  100  o.o.,the  gas  ia  drawn  in 
until  the  water  ia  a  little  below  the  zero,  the  tap 
is  okMod  and  the  leTol-bottle  ia  rained  ao  that  the 
fts  ia  alightly  compreesed  and  the  water  risea 
above  the  lero  (time  having  been  fivcn  for  the 
liquid  to  run  doun  from  the  eides  of  the  burette), 
(jid  the  indiarubber  tube  is  cloced  by  a  pinch- 
sock.  The  level-bottle  is  again  lowered,  and  b^ 
cautkmaly  openins  the  pinch-cock  the  water  )■ 
allowed  to  deaoend  exactly  to  the  isro,  and  the 
pinok-eockia  dosed.  The  tap  at  the  end  of  tlte 
mun  OApilluy  ic  opened  for  an  Inatant,  to  that 
the  exoeae  of  na  may  escape  and  the  100  o.c. 
—  -'-  —  -  'n  the  burette  may  be  at  atmoaphcrio 


the  tap  of  the  jAiticular  bulh  it  opened.     

gaa  psMee  into  the  bulb,  and  bv  altemately 
raiaing  and  lowering  the  lerel-bottM  tiie  na  oan 
be  pamed  backwards  and  forwardi  seveTal  times, 
care  being  taken  that  the  absorbing  liquid  does 
not  pui  throogb  the  stop-oook.  The  ga«  is 
6nany  drawn  oS  so  that  the  absorbtng  liqnid 
just  reaches  the  stop-cook,  the  latter  ia  closed, 
and,  aftet  readjusting  the  leveb,  the  volume  of 
gaa  is  again  read  oC  After  making  the  nvoee- 
ear;  ixorectiona,  the  deoreaie  in  volnme  is,  of 
conrsc^  tl>a  volume  of  t^e  saa  which  haa  been 
absorbed.  The  mder  in  which  the  absorbing 
liqnida  ahould  be  applied  ha*  already  been 
given  (p.  £36). 

Lnnn  has  added  to  this  apparatus  a  capil- 
lary tnoe  vrith  palladiom  aabeato*.  tor  the 
estinution  of  hydrogen,  oonneoted  with  a  bolb 
similar  to  the  absorption  bulbs,  but  oontaiuing 
water  only.  The  apparatus  alao  contains  a 
small  Bpint-lamp  earned  by  a  movable  rod  for 
heating  the  palladium  asbMtoa  (DingL  poly.  J. 
1982,  Ua,  S12}. 

Sodeau  has  introduced  a  modiGcation  of 
Orsat's  apparatus  suitable  for  the  analysia  of 
mixtures  containing  only  small  propOTtions  of 
combui>tible  gases  {e,g.  chimney  Rases).  In 
this  modification  the  cuprous  chlDnde  pipette 
and  the  palladium  combustion  tube  are  replaced 
by  a  oombuation  pipette,  the  only  absorption 
pipettes  present  being  those  contsjning  oaustio 

Sltaah  and  alkaline  pyrogallate.  The  carbon 
LOXide  ia  firat  estimated  by  means  of  the  former, 
and  the  combustible  gaaea  burnt  by  passing  an 
electric  current  (6  amperee)  (or  a  short  time 
through  aplatinnm  spiral  in  the  combustion 
pipette.  The  contraction  is  noted,  and  the 
carbon  dioxide  produced  is  eeti  mated  by 
abeorption  in  the  canstio  potash.  These  data 
give  the  propoiiiona  of  carbon  monoxide  and 
hydrogen  originally  present  in  the  gaseous' 
nuxtoie.  The  teaidual  oxygen  may  now  be 
Vol.  1.— r. 


estimated  by  »baorption  in  the  alkaline  pyro- 
gallate (Chem.  NewB,  1904,  89.  61). 

Bon*  and  WItaUr'i  opponriiu  is  a  simple 
form  of  gas  apparatus  capaue  of  giving  accurate 
results  with  atoost  all  gaseotta  mixturteoidinarily 
met  with  in  technical  praotioe.  The  working 
liqnid  ia  mereury,  and  the  apparatna  oonsiata  <M 
the  following  parts  :  (1)  A  water-jaoketed  oom- 
Unation  of  meaaurtng  and  pieaaure  tubes,  A  and 
B,  commnnfcating  t£«ugh  the  gUsa  tap  o  with 
the  mercury  reservoir  D;  (2)  an  absorption 
vessel,  t,  standing  over  mereury  in  a  mahoganv 
trough  ;  (3}  an  enlosion  tube,  a,  Btted  witk 
firing  wires,  and  havii^  ft  aeparate  mercury 
reservoir,  H ;  (4)  a  sampfing  tube,  X.  The  ooa- 
neotions  between  a,  ■,  and  w  are  of  capillary 
bore  throughont,  witii  suitable  glaai  tapa. 
Before  an  saalybis  the  whole  of  the  appatatna, 
including  the  connections,  it  filled  with  mercury. 


Fio.  40. 

and  the  gat  may  be  introduced  either  from  the 
sampling    tube,    s,    or    from    the    absorption 

The  Regnault-Frankland  principle  of  maa- 
turenient  is  employed,  namely,  the  measorement 
of  the  pressure  of  the  gas  (in  mm.  of  mereury) 
at  constant  volume.  The  measuring  tube  A 
has  a  series  of  conntant- volume  marks  coinciding 
with  the  0.  100,  200,  Ac,  mm.  marks  on  the 
pressure  tube  b.     These  two  tubes  arc  moltteneU 


«ith  dilute talphnrioftcldil  : 20) bb a prMkution 
mgaiiut  the  uiaidenta]  intiodiiottoD  of  ^kall 
into  the  meoeuriiig  tube.  The  tap  olociug  the 
upper  end  of  the  preeeure  tube  a  connected  to 
it  by  etout  indiarubber  preesure  tubtne;  thia 
givee  a  tight  but  elutio  joint,  and  obvi»t«s 
mlu  of  fractun.  Bj  tseoni  of  this  tap  the 
pissure  tube  can  be  rendered  vacuona,  and,  in 
this  way,  the  mea«nrementa  are  rendered  mde- 
pendent  of  the  barometrio  preaame,  and  it 
becomes  powiblo  to  analyse  smaller  volamee  of 
gaa.   The  length  of  the  pressure  to  be  provides  for 


tbaorpUon  Teael  Ii  rnued  oot  by  meani  of  the 
three-my  tap,  the  lower  panJlef  limb  of  whteh 
ie  joined  to  a  large  bottle  oonneoted  up  with  the 
water  pnmp.  In  thii  way  a  seriee  of  KMorptiona 
can  1m  ouried  ont  withovt  distarbing  a  linglB 
oonneotion  in  the  appaiatiu.  An  analvRs  of  pro- 
daoei  gag  it  easily  completed  in  4S  mmntee,  and 
one  of  ooal  n«  reqairee  abont  an  hour  (J.  Soo. 
Chem.  Ind.  190S,  27,  10).  (For  other  forms  of 
teohnioal  gaa  apparatni,  v.  F.  Fuoher,  Zeitech. 
angew.  CSiem.  1890,  S,  SOI ;  Sodean,  J.  Soc 
Chem.  Ind.  1B03,  22,  187.  See  also  Chem.  Soc. 
Trans.  IBM.  66.  43;  ISM,  75,  82;  Ber.  1902, 
SB,  3480,  3493  ;  1907,  40,  4966 ;  J.  Soo.  Chem. 
Ind.  1908,  27,  483,  491  ;  Chem.  Zeit.  1903,  84fi  ; 
1904,  686 ;  Zeitscb.  angew.  Chem.  1907,  20,  22.) 

Brmp^a  apparatiu. — The  meaaurins  apph- 
ntoa  oonsiita  of  a  burette,  and  a  plain  tube 
of  the  tame  length  and  diameter,  which  tarrea 
B8  a  fsTel-tube.  The  burette  holda  100  0.0. 
from  the  lero  to  the  oapiUary,  i*  graduated  in 
Gftht  of  a  O.O.,  and  terminatet  at  the  top  in  a 
capillary  tube  to  which  is  fitted  a  short  piece  of 
atout-walled  caoutchouc  tubing  closed  by  a 
pinA-cook.  Both  the  burette  and  the  leyel-tabe 
ate  fixed  at  the  bottom  into  heavy  ciniulai 
ataada,  and  each  haa  a  aide  tubulus  near  the 
bottom  over  whioh  is  slipped  the  oaoutchouc 
tube  by  which  they  are  connected.  It  ta 
advisable  to  make  all  the  Joints  teoore  with 
copper  wire.  In  order  to  make  the  meaaure- 
menta  more  aoonrate,  the  burette  may  be 
auTTcnnded  bv  a  wider  tube  filled  with  cold 
watei  (Winkler). 

The  pinch-cock  in  opened  and  botH  tubes  are 
rather  more  than  half  liUed  with  water.    TJbe 


indiarubber  tube  at  the  top,  and  the  pinch-oock 
is  then  closed.  By  means  of  the  indiarabber 
tube  the  buretto  is  attached  to  the  oonducting 
lube,  which  haa  already  been  filled  with  the  gaa, 
the  level-tube  is  lowered,  and  the  pinch^cock 
opened.  When  aulScient  gas  haa  been  drawn  in 
the  pinch-cock  is  closed,  the  levels  adjusted,  and 
the  volume  read  off  in  the  usual  maimer.  If  it 
ia  desired  to  admit  exactly  100  cc,  proceed 
in  the  tame  way  as  deacribed   under  Orsat'a 

The  reagenta  are  contamed  in  absorption 
pipettea.  Simple  abaorption  pipettM  oooaurt  of 
two  bnlba  whioh  commonioate  at  the  bottom  by 
a  bent  tube,  one  bulb  being  at  a  higher  level  than 
the  otiier  (Fig.  34).  The  ntipo  part  of  the  low«c 
bulb  t«rminatea  in  a  stnigbt  oapillMT  tube, 
whioh  extends  t«  a  tlightly  gie«tw  height  than 
the  higher  bolb,  and  aervet  to  connect  the  pipatte 
with  the  burette.  In  the  tubulated  piprtte  the 
bottom  of  the  lower  bulb  ia  provided  with  a 
tubulus,  which  can  be  dosed  mtb  a  oaoutchouo 
stopper,  and  through  which  solid  reagenta  tucb 


Fio.  42. 


aa  phosphor 

apoaite  absorption  pipette  oonsista  of  two 
lilar  pairs  of  bulbs,  the  seoond  pair  containing 
wat«r  or  some  other  liquid  which  protects  the 
reagent  In  the  iirat  from  the  action  of  the  air- 
Ciompoaite  pipettes  are  used  with  alkaline  pyro- 
galLate,  cnprons  chloride  aolution,  bromine  water, 
and  similar  reagenla  (Fia.  42). 

Cummina  (J.  Soo  Chem.  Ind.  1013,  32,  9) 
haa  modified  the  Hempel  double  pipetto  by  the 
addition  of  a  aide  tube  to  the  top  of  b,  which 
can  be  cloaed  by  a  rubber  cork.  The  reagent  is 
poured  through  the  aide-tube  on  b,  and  i 
IS  poured  in  throug''  ■' 


^    dto  form  a  water-aeal. 

In  making  the  absoiptions  the  pipettes, 
which  are  attached  to  wooden  stands,  are  ^aoed 
on  a  table  stand  of  such  height  that  the  top  of  the 
capillary  of  the  pipette  ia  level  with  the  top  of 
the  capillary  of  the  burette.  The  burette  and 
pipette  are  joined  by  meana  of  abort  pieoea  of 
caoiit«bouo  tubing  and  a  short  piece  of  capillary 
tube  bent  twice  at  right  angles.  The  volume  ot 
air  oontained  in  tliia  capillary  is  M  tmnll  that  it 
docs  oot  introduce  any  appreciable  error.  Care 
is  taken  that  the  capillary  of  the  absorptiOB 
pipette  ia  Uled  just  up  to  the  top  with  (he  re- 
agent. The  connections  being  made,  tlie  level- 
tube,  which  should  be  fuU  of  water,  is  {daoed  on 
the  table  stand  and  the  pinob-cock  is  opttied- 
The  gas  passes  into  the  pipette,  and  by  taiaiiy 


and  lowoiing  th«  lerel-tub«  the  whole  of  tlia  g&s 
can  be  pasaed  backnrda  and  forwards  two  or 
three  timei ;  or  the  gas  may  be  allowed  (o  n- 
main  in  oonlaet  with  the  liqnid  in  the  pipette. 
Wh«a  Absarption  is  oompleto,  the  level-tnbe  is 


lowered  nntit  the  raasent  is  drawn  inst  up  to  the 
topcf  the  o^Uary  of  the  pipette,  thopindh-ooek 
is  cloaed,  and  a  Mooiid  leadW  it  tdken. 


is  cloaed,  and  a  Mooiid 

When  combnttloni  of  hydrogen  or  isarbon 
moDoiids  have  to  be  made,  the  oapiUary  tnbe 


containing  palladinm  asbestos  is  inserted 
between  the  burette  and  a  simple  absorption 
pipette  containing  water  onlv.  With  gases 
containing  both  methane  and  hydrogen,  the 
oombiution  is  conveniently  effected  in  an  ei- 
ploaion  pipette   of   spherical  foctn,  in  which 


Tare.  3^7 

mercury  is  ased  as  the  working  liquid.  The 
two  bulbs  of  tbe  pipette  are  oonneeted  l^ 
thick-waited  indiarubbeT  tubing,  and  the  ei- 
plosion  bulb  can  be  closed  b^  two  Btop-cocks. 

When  gases  very  soluble  in  water  have  to  be 
measured,  a  bnrette  is  used,  provided  at  the  top 
witi  a  three-wfty  stop-cock,  the  volume  between 
them  being  exactly  100  c.c.     The  burette  must 


Pio.  40. 

be  perfectly  dry  before  being  filled,  an  end 
which  is  moat  quickly  efiected  t^  riming  the 
bnrette  with  wat«r.  then  with  aloohol.  and 
finally  with  ether,  and  passing  a  current  of  worm 
air  through  it.  The  lower  end  of  the  burette  is 
oonnectod  with  the  conducting  tube  by  means  of 
the  three-waj  tap  d,  the  other  end  is  connected 
with  an  aspiratm',  and  a  current  of  the  gas  is 
drawn  through  the  bnrette  until  the  air  is  com- 
pletely expelled.  The  stop. cocks  are  then  closed, 
care  being  taken  that  the  gss  in  the  tube  is  at 
atmospheric  pressure.  The  absorptions,  Ac,  are 
made  in  the  same  way  as  with  the  ordinaiy 
bnrette. 

Bitad'*  apparattu  consists  (Fig.  44)  of  a 
graduated  tulie  a,  in 
which  all  measurements 
are  made,  fitted  with  taps 
B  and  □,  leading  respec- 
tively to  the  absorption 
vessel  and  the  sampling 
tube.  The  lower  end  of 
1  is  joined  by  means  of  a 
T-pieoe  to  the  mercury 
leaervoir  ■,  and  to  the 
tube  D,  which  is  open  to 
the  atmosphere  at  h. 
The  readingB  are  taken 
under  atmospheric  pres- 
sure. The  gas  sample  is 
collected  either  directly 
in  the  laboratory  vessel* 
or  in  Stead's  sampling  j 
apparatua(Fig.4fi).  From  [ 
either  ot  the.ie  reservoirs 
a  portion  of  the  gas  is 
introduced  into  the  ap- 
paratus at  o,  and  thence  


PlO.  47. 


808 


ANALYSI& 


and  the  miztim  sparked  by  meaoa  of  platinum 
teiminak  fused  into  the  upper  part  of  the 
graduated  tube  a. 

The  contraction  is  ascertained  and  the 
carbon  dioxide  produced  is  estimated,  and  from 
these  data  the  amounts  of  carbon  monoxide  and 
hydrogen  are  determined. 

When  other  absorbable  gases  are  present, 
then  six  absorption  vessels  are  employed,  and 
these  are  carried  on  a  turn-table,  so  that  each 
in  turn  can  be  brought  into  contact  with  the 
measuring  tube  (S^.  46).  In  this  modified  form 
of  the  apparatus  the  en<Uometer  tube  and  each  of 
the  absorption  Tessels  are  fitted  with  a  perfectly 
flat  piece  of  plate  glass  perforated  in  the  centre. 
These  plates  are  lightly  smeared  with  oil,  and 
when  communication  is  to  be  made  between  the 
eudiometer  and  the  absorption  vessel,  these 
face  plates  are  held  together  by  a  spring  clip 
(Pig.  47). 

A  further  improvement  consists  in  the  use  of 
the  modified  form  of  absorption  vessel  shown 
in  Fig.  48,  in  which  the  reagent  is  contained 
in  a  glass  bottle  closed  by  an  mdiarubber  bung 


Fio.  48. 

carrying  a  small  glass  stopper  and  a  pipette 
furnished  with  a  tap. 


Fio.  49. 


Fig.  60. 


By  means  of  these  additions  Stead's  apparatus 
can    be  used    for    the  complete    uuuysis    of 


furnace  and  producer  gases  and  other  technically 
important  gaseous  mixtures  (J.  Soo.  Chem.  Ind. 
1889.  8,  178). 

TJie  nitrometer,  originally  devised  by  Lunge 
(Ber.  1878, 11, 436)  for  the  estimation  of  nitro^n 
oxides  in  oil  of  vitriol,  is  capable  of  being  appUed 
to  gas  analysis  and  a  large  number  of  other 
determinations.  It  consists  (Fig.  40)  of  a 
burette,  fitted  at  the  fop  with  a  thxee-way  tap 
and  a  cup-shaped  funnel,  and  oommnnioating  at 
the  bottom  by  means  of  oaoutohonc  tubing  with 
a  plain  tube  of  the  same  diameter,  which  serves 
as  a  level-tube.  When  laige  quantities  of  gas 
have  to  be  measured,  the  upper  part  of  the 
burette  is  expanded  into  a  bulb,  and  these  is  a 
similar  bulb  on  the  level-tube  (Fig.  60). 

This  apparatus  is  used  with  mercury,  and 
k  thus  suitable  for  the  analysis  of  gsaes  soluble 
in  water.  It  can  be  used  in  the  same  way 
as  Hempel's  burette,  and  for  all  purposes  to 
which  the  latter  is  applicable.  It  may  also  be 
used  without  absorption  pipettes,  the  reagent 
being  introduced  by  means  of  the  cup,  but 
Mnoe  the  reagents  cannot  be  removed  without 
removing  the  gas,  the  latter  method  is  only  ap- 
plicable when  the  reagents  do  not  interfere  with 
each  other — e,g,  for  the  absoi^ion  of  carbon 
dioxide  by  caustic  potash,  followed  by  the  abeoi^ 
tion  of  oxysen  by  alkaline  pyrogallate. 

The  estimation  of  nitrogen  oxides  in  solution 
in  sulphuric  acid  is  conducted  in  the  following 
manner.  The  af>paratus  is  filled  with  mercury, 
so  that  when  the  tap  is  open  between  the  burette 
and  the  cup,  and  the  level -tube  is  raised,  the 
mercury  iust  passes  through  the  tap  and  stands 
at  a  height  of  about  2  incnes  in  the  level-tube. 
The  tap  is  then  closed  and  2-^  c.c.  of  the  sul- 
phuric acid«  accordinfl;  to  the  quantity  of 
nitrogen  oxides  which  it  contains,  is  placed  in 
the  eup,  the  level-tube  is  lowered  and  the  tap  is 
turned  so  that  the  acid  is  nearly  aU  drawn  mto 
the  burette  without  any  air  being  admitted.  To 
avoid  measuring  out  small  quantities  (0*6-1  o.c.) 
of  highly  nitrated  acid,  this  liquid  should  be 
diluted  with  a  known  volume  of  pure  concen- 
trated sulphuric  acid,  and  6  cc  of  this  solution 
taken  for  analysis.  The  cup  is  rinsed  with  two 
successive  quantities  of  2-3  cc.  of  pure  acid, 
which  is  drawn  into  the  cup  with  the  same 
precaution  as  before.  The  tap  being  closed, 
the  burette  is  taken  out  of  the  clamp  and 
agitated  in  such  a  manner  that  the  liquid  is 
brought  thoroughly  into  contact  with  the  first 
10  cm.  or  so  of  the  mercury,  which  is  broken 
up  into  bubbles.  Nitric  onde  is  formed  and 
collects  in  the  upper  part  of  the  tube.  When 
no  more  gas  is  given  off,  the  levels  are  adjusted 
and  the  volume  read  off  after  the  froth  has 
subsided.  In  adjusting  the  levels  the  difference 
between  the  specific  gravity  of  the  acid  and  the 
mercury  is  allowed  for  by  taking  6*6  mm.  oU 
acid  B  1  mm.  of  mercury.  A  smul  quantity  of 
acid  L)  placed  in  the  cup  and  the  tap  opened  :  if 
the  acia  is  drawn  in  the  pressure  in  the  burette 
was  too  low ;  if  gas  escapes,  the  pressure  was  too 
high.  It  is  better  to  err  on  the  side  of  too  low 
pressure,  which  is  readily  corrected  by  allowing 
acid  to  run  in  from  the  cup  and  taking  another 
reading. 

In  agitating,  care  should  be  taken  that  the 
drop  of  acid  which  collects  in  the  top  of  the 
burette  just  below  the  tap  does  not  escape  eon- 


ANALYSIS. 


809 


taot  witli  the  mereury,  otherwise  the  results  will 
be  too  low. 

To  prepare  for  another  estimation,  the  level- 
tube  is  raised  and  the  tap  is  opened  so  that  all 
the  aoid  and  some  of  the  mercury  is  driven  into 
the  cup,  and  the  tap  is  then  turned  so  that  tiie 
acid  runs  out  at  the  side. 

The  nitrometer  may  be  used  for  the  valuation 
of  nitrites  and  nitrates,  which  are  introduced  in 
the  form  of  a  concentrated  aqueous  solution, 
care  being  taken  that  the  proportion  of  water  to 
aoid  does  not  exceed  2  parts  of  aqueous  solution 
to  3  parts  of  the  strongest  acid.  It  mav  also  be 
used  for  the  estimation  of  nitrates  and  nitrites 
in  potable  waters,  and  in  fact  for  almost  any 
determinations  in  which  a  definite  volume  of 
gas  is  ^ven  o£f.  For  example,  the  estimation  of 
carbonic  acid ;  of  urea  by  hypobromite  (the 
reading  being  increased  by  9  p.c.  to  correct  for 
solubility  of  the  gas  and  incomplete  decom- 
position); hydrogen  peroxide  by  an  acidified 
solution  of  potaraium  permanganate,  or,  vice 
versa,  the  value  of  a  permanganate  solution  by 
means  of  hydrogen  peroxide,  &c.  [Ses  Lunge^ 
Ber.  1878,  11,  436;  J.  Soc.  Chem.  Ind.  1885, 
4,  447,  and  1886,  0,  82;  Zeitsoh.  anal.  Chem. 
25,  309;  and  the  translation  of  Winkler's 
Technical  Gas  Analysis  (1885);  also  Allen, 
J.  Soa  Chem.  Ind.  1885,  4,  178.) 

The  gM-volumeter,  Several  of  the  estima- 
tions referred  to  in  the  preceding  paragraph  are 
more  conveniently  carried  out  in  the  gas- 
Folumeter  devised  by  Lunge,  as  in  this  apparatus 

the  decomposi- 
tion can  be  ef- 
fected in  a  sepa- 
rate vessel.  The 
measuring  tube  A 
and  the  reservoir 
o  are  converted 
by  means  of  the 
T-piece  D,  with 
tiie  so-called  *  re- 
Q  duotion '  tube  b. 
At  the  outset 
the  temperature 
and  pressure  are 
observed,  and  the 
volume  occupied 
under  these  con- 
ditions by  100  c.c. 
of  dry  (or  moist) 
air  measured  at 
(f  and  760  mm. 
is  calculated.  The 
reduction  tube  is 
filled  with  air  to 
this  volume,  and 
the  tap  of  the 
tube  closed,  or 
the  end  of  the 
reduction  tube 
may  be  termi- 
nat^ed  by  a  capil- 
lary and  sealed  ofi  after  the  volume  nas  been 
correctly  adjusted.  A  special  tap  for  the  reduc- 
tion tube  has  been  devised  by  Gockel  (Zeitech. 
angew.  Chem.  1900,  13,  961,  1238).  If  moist 
pJBes  are  to  be  measured,  a  small  drop  of  water 
18  introduced  into  the  reduction  tube;  if  dry 
gases  are  under  examination,  a  drop  of  concen- 
trated sulphuric  acid  must  be  introduced  into 


Fia.  5L 


the  re du ciion  tube.  The  formulae  for  calculating 
the  volume  of  gas  in  the  reduction  tube  are  as 
follows : — 

where  Vj  »  volume  of  gas  required  ; 

VoSB  normal  volume  {e.g.  100  c.o.) ; 
I  B  observed  temperature ; 
B  B  observed  barometric  pressure ; 
/  =3  tension  of  water  vapour  at  observed 
tempcratm^ 

When  a  decomposition  by  sodium  hypo- 
bromite or  hydrogen  peroxide  has  been  carried 
out  in  the  auxiliary  generating  bottle,  the  aaa 
evolved  passes  into  the  measuring  tube  ▲.  Ihe 
mercury  in  ▲  and  o  are  then  Mjusted  to  the 
same  level,  and  the  tap  o  closed,  the  gas  being 
then  at  the  atmosphere  pressure.  Ihe  three 
tubes  are  now  adjusted  so  that  the  mercury  in 
L  and  B  are  at  the  same  level  when  the  mercury 
in  the  latter  tube  stands  at  the  100  c.c.  gradua- 
tion. The  gases  in  A  and  B  are  at  the  same 
temperature  and  under  the  same  pressure,  and 
since  the  gas  in  B  occupies  the  same  volume  as 
it  would  at  0^  and  760  mm.  pressure,  it  follows 
that  the  gas  in  a  also  occupies  the  same  volume 
as  it  woiud  under  the  standard  conditions.  In 
this  way,  b^  the  use  of  the  gas-volumeter,  all 
thermometnc  and  barometric  readings  and  all 
reductions  by  calculations  or  special  tables  are 
avoided;  for  the  volume  of  gas  is  read  ofiE 
directly  under  conditions  corresponding  to  the 
normal  pressure  and  temperature.  It  is,  how- 
ever, essential  that  the  reduction  tube  should 
be  arranged  for  dry  or  moist  gases  according  to 
the  nature  of  the  analytical  operation  involved 
{v.  Lunge,  Ber.  1890,  23,  440;  1891,  24,  729; 
1892,  25,  3157 ;  Zeitsch.  angew.  Chem.  1890,  3, 
129  ;  1891,  4,  197,  410 ;  1892,  5,  677  ;  J.  Soc. 
Chem.  Ind.  1890,  9,  547.  Cf.  Gruskiowicz, 
Zeitsch.  anaL  Chem.  1904,  43,  85). 

In  addition  to  the  hypobromite  and  hydrogen 
peroxide  decompositions.  Lunge  and  March- 
lewski  have  adapted  the  gas-volumeter  to  the 
estimation  of  carbon  dioxide  in  natural  car- 
bonates, Portland  cement,  and  other  mineral 
substances,  and  also  to  the  determination  of 
carbon  in  iron  and  steel  (Zeitsch.  angew.  Chenu 
1891,  4,  229  ;  1893,  6,  395 ;  J.  Soc.  Chem.  Ind. 
1891,  10,  668).  G.  T.  M. 

Elxctbochemioal  Avalysis. 

The  first  suggestion  to  apply  the  electric 
current  to  the  deposition  of  metals  was  made 
bv  (>uiokshank  in  1801  (Nicholson's  Journal  of 
ifat.  Phil.  1801,  4,  254).  He  noticed  that  metals 
were  deposited  from  acid  or  alkaline  solutions 
of  their  salts  at  the  negative  pole,  and  that  the 
metal  went  into  solution  at  the  positive  pole. 
He  therefore  suggested  that  the  electric  current 
might  thus  be  used  as  an  aid  to  analysis,  par- 
ticularly for  depositing  lead,  copper,  and  silvcrt 

In  1812  Fischer  suggested  its  use  for  detecting 
small  quantities  of  arsenic  (Gilbert's  Annalen, 
42,  92).  In  1840  Cozzi  (Arch,  delle  Science 
med.  fifl  50,  ii.  208)  employed  the  galvanic 
cttrrent  (produced  by  plates  of  gold  and  zinc 
connected  together  by  a  wire)  to  ascertain 
whether  organic  fluids,  such  as  milk,  contained 
metailio  impurities.     Gaultier  de  Ciaubry    (J. 


310 


ANALYSIS. 


PLft.m  Ciiim.  iii.  17,  125)  applied  it  to  detect 
small  Quantities  of  azsenic  id  animal  fluidfl.  In 
18C1,  Bloxam  (Quart.  Journ.  Chem.  Soc.  13, 
12,  338)  described  an  electrolytic  method  for 
detecting  arsenic  and  antimony.  Becquerel 
(Ann.  ChinL  Phya  1830,  43,  380)  found  that 
manganese  and  lead  were  readily  oxidised,  and 
appeared  as  oxides  on  the  anode. 

All  these  workers  appear  to  have  merely 
u»ed  the  electric  current  as  an  aid  to  qualitative 
analysis.  Woloott  Gibbs  (Zeitsoh.  AnaL  Chem. 
3,  334),  in  1804,  showed  that  copper,  nickel, 
sine,  lead,  and  manganese  might  oe  quantita- 
tively determined  by  means  of  the  electric 
current.  Lucknow  (DingL  Poly.  J.  1865,  177, 
231,  and  178,  42),  from  1860,  had  employed 
electrol3rtio  methods  for  the  quantitative 
analysis  of  copper  salts  and  for  commercial 
copper.  From  tnis  time  forward  many  worken 
entered  the  field,  and  about  1880  Edgar  Smith 
in  America,  and  Classen  in  Germany,  very 
much  advanced  the  subject  of  electro-analysis, 
and  to-day  it  is  one  of  the  most  useful  helps  to 
the  analytical  chemist. 

Before  dealing  with  the  methods  of  deposition 
and  separation  of  the  metals,  it  will  be  well  to 
describe  the  apparatus  used;  but  only  the 
apparatus  most  generally  employed  will  be 
dealt  with. 

CLsasen  first  suggested  the  employment  of  a 
platinnm  basin  as  cathode  and  a  platinum  disc 
as  anode.  A  convenient  stand  for  holding  the 
basin,  and  a  method  of  connecting  with  the 
source  of  current,  are  shown  in  Fis.  52.  The  basin 

+  should  hold  from 
160  to  180  0.0.  of 
solution.  The 
inner  surface  of 
the  basin  should 
be  roughened  by 
the  sand  blast,  as 
this  causes  better 
adherence  of  the 
deposit,  especi- 
ally in  the  case 
of  peroxides  such 
as  lead  and  man- 
ganese. The  base 
of  the  stand  is  of 
slate  or  marUe, 
and  the  brass  rod 
which  convejTS 
the  —  current  is 
hollow ;  through 
this  brass  rod  an 
insulated  wire  for 
carrying  the  + 
current  passes, 
and  is  connected 
at  the  top  of  the 

•  rod  by  means  of 

^*o-  «^2.  a  piece  of  ebonite. 

The  ring  which  supports  the  basin  has  three  little 
platinum  points  at  equal  intervals  on  its  circum- 
ference ;  on  these  the  basin  rests,  thus  ensuring 
good  contact.  The  positive  pole  of  the 
source  of  current  is  connected  with  the  binding- 
screw  fixed  to  the  slate  base,  and  the 
negative  pole  with  the  binding  •  screw 
marked  ^.  In  dealing  with  metals  which 
deposit  as  oxidea  on  the  positive  pola  the 
basin  is  connected  with  the  +  poW^ 


Another  useful  form  of  electrode  is  illus- 
trated in  Fig.  53.  The  anode  is  a  stout 
spiral  of  platinum  and 
the  cathode  is  a  cylinder 
of  platinum  gauze.  This** 
form  of  electrode  can  be  I 
employed  either  for  station- 
ary work  or  for  rapid  depo- 
sition work  when  the  anode 
is  rotated.  The  vessel  in 
which  the  electrolysis  takes 
place  may  either  be  .  a 
oeaker  or,  better,  a  funnel 
with  a  tap  such  as  is  illus- 
trated in  Fi^.  67. 

For  stationary  work  the 
Flag  electrode  of  F.  MoU- 
wo  Perkin  (Fig.  54)  gives 
very  satisfactory  reralts. 
The  cathode  consists  of 
a  small  sheet  of  stout 
platinum  ffauze,autogenous- 
ly  fastened  on  to  a  rigidplati- 
num-iridium  frame,  both 
frame  and  gauze  being  rough-  ip,.    »« 

ened    by    the    sand   blart.  "°-  "' 

The  wire  holds  the  electrode  in  position  during 
the  analysis.  The  loop  near  the  top  of  the  wire 
serves  to  hanf>the  dectrode  on  the  balance. 
The  anode  is 
made  of  plati- 
num wire,  and 
is  bent  upon 
itself  in  sucn  a 
wa^  that  when 
it  18  placed  in 
position  for 
electroljTsis,  as 
illustrated  in 
Fig.  55,  an  even 
density  is  ob- 
tained on  all 
parts  of  the 
oathode. 

It  has  been 
found  that  the 
rate  of  deposi- 
tion of  metals 
from  their  solu- 
tions is  very  much  increased  and  higher  current 
densities  can  be  employed  when  either  the 
anode  or  oathode  is  xanidly  rotated.  ¥tary 
{Zeii,  t  Slektroohem.  1907,  308)  has  also  shown 
that  excellent  results  can  be  obtained  by  electro- 
lynng  with  statiomvy  electrodes,  bat  eanaing 
agitation  of  the  electrolyte  by  pladns  the  whole 
apparatus  in  the  field  of  a  poweitul  electro- 
magnet. The  f ormf  of  the  apparatus  are 
depicted  in  Fi^.  56.  From  the  figure  it  is  seen 
that  the  solution  is  contained  in  a  beaker  b,  in 
which  is  a  cylindrical  platinnm  gauze  cathode  o 
and  a  heavy  platinum  wiro  as  anode  a.  The 
beaker  is  placed  in  the  centre  of  a  spool  made 
^m  insulated  copper  wire  n.  By  paiwing  an 
electric  current  through  the  copper  wire  of  the 
spool,  a  powerful  magnetic  fiela  is  produced,  in 
the  centre  of  which  the  beaker  stanoa.  If  now  a 
cuixent  be  passed  through  the  electrolyte  by 
means  of  the  electrodes,  the  electric  lines  of  force 
are  cut  at  right  angled  by  the  magnetic  lines  of 
force,  and  tiiis  produces  a  tendencv  for  the 
solution  to  rotate,  owing  to  the  vertical  magnetio 


Fig.  54. 


being    »    radial    field    with     TertJcal    oomnt 

The  advuiUgM  oUimed  for  this  method 
re :  rapidity  of  depomtJon,  and,  aa  th«i«  are 
a  meoluutioal  parts  which  require  lubnealion, 
lere  is  DO  ohano«  erf  oontammation  team  oil, 
r  greaae  aecidenlallj  falling  into  the  *ola- 
lion.    Aa   a   matter   of   fact,   howevw,   lapid 


Fio.  65. 
electtio  onrrent  and  the  magnetio  current. 


With 
an  eleclrolyB- 
ing  onrrent  of 
from  e  to  7 
amp«ni,  Prary 

gram      copper 


67, 


Fio.  M. 


,  eleotrolysiog 

ODry  cathode, 
I  and  applicatiooa  of  which  will  be 
described  Ik  tor. 
The  electrolys- 
ing Teasel  is 
ring-ihaped,  ao 
that  it  may  fit 
into  a  hole  cut 
into  the  pole  d 
of  the  magnet. 

passes  from  the 
other  pole  op 
into  the  centre 
of  the  electro - 
lysine  veaael.  a 
ia  the  anode 
tad  o  the  ca- 
!   thode.         Ex- 


I   of     tha     magnetje     oumnt,     there 


Fio.  fiS. 
methoda   of   electrolysia   are   more   freqaently 
carried  out  by  means  ol  a  rotating  anode  or 
cathode. 

Gooch  and  Medway  (Amer.  J.  Sci.  IB,  330) 
use   a  rotating   cathode.     It  ia  made  from   a 
ilatinum   crucible   of   about  20  o.o.   capacity, 
'ha  crucible  ia  attached  to  the  shaft  ol  the 
electromotor,  which  is  used  to  rotate  it  at 
ipe«dof  from  600  to  SOO  revolutiunsper 
nute  by  fitting  it  over  a  rubber  stopper 
with  a  central  bore,  into  which  the  end  of 
the  shaft  fits  tightly.     In  order  to  make 
electrical  connectiun  between  the  crucible 
and  the  shaft  of  the  motor,  a  narrow  atrip 
of  sheet  platinum  is  soldered  to  the  shaft 
and  bent  upwards  along  the  sides  of  the 
atopper.   Thia  connects  the  shaft  with  the 
inside  ol  the  crucible  when  the  latter  ia 
pressed  over  the  stopper.    The  anode  con- 
si4t«  of  a  half  cylinder  of  sheet  platinum. 
I'ig.  68  representa  the  arrangement  of  the 
apparatus  when  fitted  together. 

F.  MoUwo  Perkin  and  W.  E.  Hughes  I,  J 
(Tranfl.raCBdaySoc.l010,U)uBeanoleo.  _  ,. 
trode  of  sheet  platinum  apun  up  so  as  to 
form  a  narrow  thimble  ( Fig.  60),  the  upper  end  be- 
ing open  and  having  a  stout  iridio- platinum  wire 
fused  on  to  it  by  meana  of  three  short  wire  sup- 
ports. This  electrode  is  fixed  into  a  small  chuck 
and  rapidly  rotated  by  means  of  an  electromotor, 
the  speed  of  rotation  usually  being  from  760  to 
D60  revolutions  per  minute.  When  in  uae,  about 
two-thirda  of  the  length  of  the  thimble  is  dipped 


)18  ANAL' 

into  the  eleotrol3't«,  the  aotive  sorioce  beiiu  abou 
16'3  aq.  cm.  If  dipped  too  deeply  into  the  solu 
tion,  there  ii  a  tendency  for  the  liqaid  to  (plBsl 
into  the  interior  of  the  oylinder,  ajid  t^  vould 
of  foone,  lead  to  erroneoiu  reaolta.  The  anodi 
cODiiste  at  a  platinnm  cylinder  of  Gne  meah 
It  ia,  however,  freqnently  mote  Mtirfactory  ti 
emplov  a  rotatios  anode  and  a  etationan 
oaUloae,  and  for  this  purpose  the  ganze  anodi 
ia  employed  as  cathode,  and  the  anode  contisb 
of  a  spiral  of  stout  iridio-ptatinnm  wire.  Th< 
simpleet  arrangement  is  illustrated  in  Fig.  63 
The  electrolysiug  vessel  consiste  of  a  tap  runne 
which,  when  the  eleotrodee  are  oovered,  holdl 
about  80  to  70  o.o.  of  solution.  The  advantegl 
of  this  form  of  eteotrolysiug  vessel  is  the  essi 
with  which  the  electrolyte  can  be  removed  oc 
the  completion  of  the  electrolyms  and  tlu 
electrodes  washed.  The  method  of  ptooedon 
is  to  place  a  beaker  beneath  the  tap  and  draw 
off  the  solution  until  about  half  of  it  has  run  in. 
Distilled  water  is  then  mn  up  to  the  original 
marh  and  the  solution  drawn  off  M  bwora. 
The  operation  is  repeated  until  the  ammetca 
needle  sLoks  to  lero.  The  remaining  water  ii 
run  off,  the  tap  dosed,  and  the  funnel  filled  with 
pore  methylated  spirit.  This  ia  run  off,  and, 
after  a  final  wasMug  with  abeolule  alcohol, 
OMTied  otit  in  the  same  manner,  the  electrodes 
MO  removed  and  the  catiiode  dried  in  the  steam 


Fib.  6a 

oontlett  ol  a  cylinder  of  pUtinam  game.  The 
anode  ie  in  the  form  of  a  double  cinde  of  stout 
platiDum  wire,  and  has  four  small  baffle  platca 
BO  pUeed  as  to  prevent  it  fiom  rotating  wiUi  the 
cathode. 

In  ordo'  to  rotate  the  anode  [or  cathode), 
-'  -s  fixed  into  a  small  ohuok  fastened  o    '     " 


be  clamped  to  anv  suitable  support. 
IT  end  of  the  spindle  has  a  sheM  of  p 


r^DOBiBts    of    a    pair    oT  platjnun 


ANALYSIS. 


313 


electrodes  (Fig.  61),  an  inner  rotating  elec- 
trode A,  and  an  outer  electrode  b.  Tlie 
two  are  kept  in  position  xeJatiyely  to  each 
other  by  means  of  a  glass  tnbe,  which  is 
slipped  through  the  collar  and  the  ring  of  the 
outer  electrode  b.  It  is  gripped  firmly  by 
the  former,  but  passes  loesdy  through  the 
latter.  The  hollow  iridio-platinum  stem  a 
of  the  inner  electrode  is  passed  through  the 
gktfB  tube,  in  which  it  rotates  freely.  The  mesh 
of  Uke  gauze  is  14*  per  sq.  cm.  The  gauze 
of  the  outer  electrode  almost  completely  stops 
the  rotation  of  the  liquid.  The  electrolyte  is, 
therefore,  ejected  rapidly  from  the  centre  of 
the  inner  electrode  by  centrifugal  force,  and  is 
continuaUy  replaced  by  liquid  drawn  in  from 
the  top  and  the  bottom.  So  great  ia  the  suction 
thus  produced,  that  when  the  electrode  is  moving 
rapioiy,  c^ps  of  wood  or  paper  placed  in  the 
solution  are  drawn  down  to  the  top  of  the 
outer  electrode.  The  circulation  is  practically 
independent  of  the  size  of  the  beaker  employedf. 
As  the  outer  electrode  surrounds  the  inner 
completely,  the  lines  of  flow  of  the  current  are 
contained  between  the  two,  and  even  when 
strong  currents  are  employed,  the  potential 
of  the  electrolyte  anywheie  outside  the  outer 
electrode  is  practically  the  same  as  that  of  the 
layer  of  liquid  in  immediate  contact  with  it. 
Fig.  62  shows  the  apparatus  with  stand  and 

motor  in  work- 
ing order.  Be- 
fore  the  method 
adopted  for  eiec- 
trolysinff  by 
means  cu  graded 
potential  is  dis- 
cussed, the  mer- 
cury cathode  de- 
vised by  Smith 
and  Howard  will 
be  described. 

WolcottGibbs, 
in  1880,  first  sug- 
gested the  use  of 
metallic  mercury 
as  cathode,  a 
definite  amount 
being  weighed 
into  a  beaker, 
where  it  was  con* 
nected  by  means 
of  platinum  wire 
with  the  nega- 
tive pole  of  a 
batte^.  Various 
metallio  salt 
solutions  were 
experimented 
upon,  and,  in 
1883  (Amer. 
Chem.J.13,571), 
Gibbs        stated 


Ftg.  63. 


that  '  It  was  found  possible  to  separate  iron, 
cobalt,  nickel,  zinc,  cadmium,  and  copper  so 
completely  from  solutions  of  the  respective 
sulphates  that  no  trace  of  metal  could  be 
detected  in  the  respective  liquids.'  Gibbs  had 
in  view  not  onlv  the  determination  of  the 
metals,  but  also  ot  the  anion  left  in  the  solution 
by  titration. 

In  1886  Luokow  (Chem.  Zeit.   9,   338,  and 


Zeitaoh.  anal.  Chem.  26^  113)  su^ested  the  addi- 
tion of  a  known  weight  of  a  aolution  of  a  mercury 
salt  to  a  solution  of  line  sulphate,  and  so  to 
deposit  zinc  and  mercury  simultaneously. 
In  1891  Vortman  (Ber.  24,  2749)  susgested  a 
similar  method,  and  employed  it  in  tto  deter* 
mination  of  several  metals.  Drown  and 
McKenna  (Amer.  Chem.  J.  6, 627)  further  worked 
at  the  subject,  using  an  apparatus  somewhat 
similar  to  Wolcott  Gibbs,  that  is  to  say,  an 
actual  meroury  cathode,  but  the  process  was 
first  successfully  worked  out  by  Edgar  Smith 
and  his  ooUaliorators  (J.  Amer.  Chem.  Soc 
25,  886).  The  apparatus  employed  consists 
of  a  small  tube  or  beaker  of  about  60  o.c. 
capacity,  dose  to  the  bottom  of  which  a 
thin  platinum  wire  is  introduced  bv  means  of 
which  the  current  is  supjdied  to  the  mercury 
cathode  (Fig.  63). 

The  external  part  of  the  platinum  wire 
touches  a  disc  of  sheet  copper  on  which  the 
beaker  rests,  and  which  is  connected  with  the 
negative  source  of  the  current. 

The  anode  is  either  a  perforated  disc  of 
^tinum  or  a  stout  spiral  of  platinum  wire. 
Durinff  the  electrolysis  the  anode  ia  rapidly 
rotat^i  by  means  d  an  electromotor  or  water 
turbine. 

The  chief  difficulty  in  using  the  meroury 
cathode  is  the  trouble  experienced  in  washine 
and  drying  it.  The  solution  left  at  the  end  of 
the  eleotroIysiB  is  siphoned  off,  and  at  the  same 
time  distilled  water  is  run  in  until  the  needle  of 
the  ammeter  drops  to  zero.  Then,  and  not  till 
then,  the  current  is  switched  off.  The  inside  of 
the  beaker  and  the  amalgam  are  rinsed  with 
alcohol  three  times,  and  finally  with  dry  ether. 
It  ia  advantaseous,  in  order  to  drive  out 
thoroughly  the  last  traces  of  ether,  to  bk>w  dry 
air  into  the  beaker  for  a  few  minutes.  After 
standing  for  half  an  hour,  the  apparatus  is  ready 
for  weighing.  F.  M.  Perkin  (Trans.  Faraday 
Soc.  1910,  14)  uses  a  small  quarts  beaker  as 
containing  vessel,  with  an  iridium  wire  fused 
into  it  to  make  contact  with  the  mercury.  The 
advantage  of  iridium  ia  that  it  does  not  amalga- 
mate with  the  mercury.  An  advantage  of  the 
quartz  vessel  is  that  it  can  be  heated  to  redness 
for  purposes  of  cleansing.  The  apparatus  is 
illustrated  in  Fie.  64.  It  will  bo  noticed  that  a 
siphon  tube  is  fused 
into  one  side  of  the 
beaker.  The  layer  of 
mercury  must  not  be 
sufficient  in  quantity 
to  dose  the  side  tube. 
A  spiral  iridio-plati- 
num  anode  is  em- 
ployed. When  the 
electrolysis  is  finished, 
a  piece  of  rubber  tube 
is  fastened  to  the 
bent  end  of  the  siphon. 
Distilled  water  is 
added  so  that  the 
solution  begins  to 
siphon  over  into  a 
beaker  placed  below 
the  rubber  tube.  In 
order  to  work  with 
as  small  a  quantity  of  water  as  possible  and  in 
cases  where  the  solution  is  required  again,  e.g. 


Fio. 


314 


ANALYSIS. 


in  metol  leparatioiis,  the  Eolation  is  allowed 
to  run  ont  until  its  level  drops  almost  to  the 


Fio.  65. 

end  of  the  anode.  Fresh  water  is  then  run  in, 
and  the  operation  repeated  until  the  ammeter 
needle  ponits  to  zero.    For  purposes  of  steadi- 


Ory 


Battery 


I  I 


Rheostat 
l\/VA/SAAA/VS/SAAAA/WSAA/ 


FiQ.  66. 


Electrometer 


7f 


J 


ness  the  ysssel  is  held  between  clips  on  a  copper 

plate. 

By  means  of  the  mercury 
cathoiie  not  only  can  the  cations 
be  rapidly  and  accurately  deter- 
mined, but  also  the  amons  ro- 
mainin^  in  the  solution. 

Various  substitutes  for  plati- 
num electrodes  in  electro-ana- 
lysis have  been  suggested  («ee 
Nicolardot  and  Boudet,  Bull. 
Soc.  chim.  1918,  [iv.]  23,  387), 
eg.  gold,  gold-platinum  alloys, 
copper,  and  certain  proprietary 
iron-alloys.  An  alloy  of  gold  (7) 
and  platinum  (1)  serves  well  in 
all  ciroumstances  for  cathodes. 
As  anodes  such  electrodes  are 
less  satisfactory  and  must  not 
be  used  for  the  anodic  deposition 
of  lead,  nor  with  cyanide  eleo- 
no.  67.        trolytes,   unless    electro-plated 

with  platinum.     In  ^mmftTiji^ft]  solution  such 

elaotrodes  acquire  a  light  brown  colour,  and 


increase  slightly  in  weight,  but  retnm  to 
their  original  weight  ai^  appearance  when 
heated  to  SOO^"  (Anidyst,  1919,  38). 

MfXhoi  of  Qraded  PoUiUiaL 

Each  metal  has  a  particular  potential  at 
which  it  begins  to  be  deposited;  below  this 
potential  it  is  not  possible  to  deposit  the  metal. 
It  follows,  Uieiefore,  that  when  dealing  with  a 
solution  containing  the  salts  of  two  or  n^fire 
metals  it  will  be  possible,  provided  the  depoddon 
potentials  of  the  metals  do  not  lie  too  near 
together,  to  deposit  the  metals  separately,  by  first 
working  with  the  lowest  potential  at  which  one  of 
the  metals  will  be  deposited.  When  this  metal 
has  heca  deposited  the  next  one  in  the  potential 
series  will  be  deposited  by  raising  the  potential. 
This  methoa  of  analysis  was  suggested  by 
Kiliani  in  1883,  and  was  further  elaU>rated  by 
Froudenbefg  wortdng  in  Ostwalda  laboratory 
(Zeit.  phyokal.  Chem.  12,  97).  But  it  was 
H.  J.  S.  Sand  (Trans.  Chem.  Soa  1907,  373) 
who  first  worked  out  the  method  and  used  the 
apparatus  with  the  rotating  cathode  already 
mentioned.  The  potential  is  kept  at  constant 
value  by  means  of  an  auxiliary  deelrode.  Such 
an  auxiliary  electrode,  designed  by  Sand,  is 
illustrated  in  Fig.  66.  It  is  a  mercury-mercurous 
sulphate  2^-sulphurio  acid  electrode.  The 
distinctive  feature  of  the  electrode  is  in  the  funnel 
F,  and  connecting  glass  tube  ab.  The  two-way 
J.  tap  allows  the  funnel  f 

to  be  connected  with 
either  limb  of  the  glass 
tube  AB,  or  closes  all  parts 
from  each  other.  The 
limb  A  permanently  con- 
tains tne  2iV-sulphurio 
acid  solution  of  the  elec- 
trode. But  the  limb  b 
is  filled  for  each  experi- 

Cathode  ^^^^  ttom  the  funnel  f 
with  a  suitable  connect- 
ing     liquid,      generally 
sodium  sulphate  solution. 
The  end  of  b  is  made  of 
thin  tube  of  about  1 }  mm. 
bore,  and  is  bent  round 
miniiniaA  oonvection.    While 
use,  the  tap,  which  must 
grease,  is  closed,  the  film 


Cell 


ySAAAAA/yWAA/SAAAAA/ 

Volt-" 
meter 


to 


several  times 

the  electrode  is  in 

be  kept  free  from 

of  liquid  held  round  the  barrel  by  capillary 

attraction,   making   the  electrical  connection, 

but  towaids  the  end  of  a  determination,  a  few 

drops  are  run  out  in  order  to  expel  any  salt 

which  ma^  have  diffused  into  the  tube. 

Electrtcal  connections. — ^For  separations  by 
eraded  potential  the  electrical  connections  must 
oe  made  as  shown  in  Fig.  66  a  and  h.  The 
battel^  is  connected  diractly  to  the  two  ends  of 
a  slidmg  rheostat,  the  electrolytic  cell  to  one 
of  them  and  the  slider.  It  is  essential  that 
the  sliding  contact  should  be  good.  The 
arrangement  adopted  for  the  measurement  of 
the  potential-difference  auxiliaiy  electrode- 
cathode  is  one  which  has  been  frequently  em- 
ployed in  electro-chemical  resesich.  The  elec- 
tromotive force  to  be  measured  is  balanced 
acainst  a  known  electromotive  force  by^  means 
of  a  capillary  electrometer.  The  known  electro- 
motive force  is  drawn  from  a  sliding  rheostat^ 
the  ends  of  which  an  connected  with  one  or 


ANALYSIS. 


316 


two  diy  oeUs.  The  value  of  the  E.M.F.  is 
read  directly  on  a  delicate  Toltmeter  (range 
1*5  volts).  For  potential  differences  greator 
than  1*6  volts,  a  Helmholtz  l^volt  instrument 
may  be  interposed  between  the  auxiliary  eleo- 
trode  and  tne  rheostat.  The  azrangement 
allows  the  voltaee  to  be  measured  almost 
instantaneously,  which  is  a  matter  of  great 
importance. 

To  carrv  out  an  experiment,  the  cathode, 
anode,  and  auxiliary  electrode  are  placed  in 
position,  the  electrolyte  is  heated  to  the  required 
temperature,  and  covered  with  a  set  of  clock- 
glasses  having  suitable  openings  for  the  elec- 
trodes. For  the  purpose  of  a  separation,  the 
current  is  usually  started  at  about  3-4  amperes, 
and  the  potential  of  the  auxiliary  electrode 
noted.  As  a  rule,  this  is  only  slightly  above  the 
equilibrium  potential.  The  current  is  then 
regulated  so  that  the  potential  of  the  electrode 
may  remain  constant.  When  no  side-reactions 
take  place,  the  current  falls  to  a  small  residual 
value  (generally  about  0*2  ampere),  as  the  metal 
to  be  segDorated  disappearB  uom  the  solution. 
The  auxuiaiy  electrode  is  then  allowed  to  rise 
0*1-0*2  volt»  aoeordiog  to  the  metal. 

It  is  obviouslv  a  matter  of  great  importance 
to  know  when  all  the  metal  has  been  deposited. 
Under  the  conditions  just  assumed,  the  amount 
deposited  per  unit  of  time  may  be  taken  as 
roughlyproportional  to  the  amount  still  in  solu- 
tion. Tois  oeing  so,  it  follows  that  the  amount 
in  solution  will  decrease  in  geometrical  ratio 
durins  successive  equal  intervsJs  of  time.  If 
we,  merefore,  make  the  safe  assumption  that 
the  concentration  of  the  metal  has  faUen  to 
under  1  p.c.  of  its  original  value  in  the  time 
during  which  the  potential  and  the  current  have 
been  Drought  to  their  final  value,  it  ia  clear 
that  by  continuing  the  experiment  half  as  long 
again,  the  concentration  of  the  metal  will  fall 
to  under  0*1  p.o.,  so  that  the  deposition  can  be 
considered  finished. 

In  cases  where  side-reactions  occur,  the 
current  does  not  fall  to  zero,  but  it  generally 
attains  a  constant  value  which  allows  it  to  be 
seen  when  all  the  metal  has  been  removed.  In 
certain  cases  this  can  be  tested  for  chemically, 
and  by  continuing  the  experiment  for  about 
half  as  long  again  as  this  reaction  demands,  the 
metal  may  be  safely  assumed  to  have  been 
deposited  completely.  This  method  may  be 
adopted,  for  example,  in  the  separation  of  lead 
from  cadmium,  the  former  being  roughly  tested 
for  by  sulphuric  acid.  If  none  of  these  methods 
is  available,  the  metal  must  be  deposited  to 
constant  weight,  or  else  the  separation  must  be 
carried  out  under  very  carefully  defined  con- 
ditions for  a  length  of  time  proved  by  previous 
experiment  to  be  more  than  sufficient. 

Sand  has  simplified  the  apparatus  necessary 
for  the  potential  measurements  by  fitting  all  the 
apparatus  required  for  the  measurement  of  the 
electrode  potential  into  a  single  box.  Full  par- 
ticulars will  be  found  in  Trans.  Faraday  Soc. 
1909.  162. 

F.  M.  Perkin  uses  the  apparatus  depicted  in 
Fig.  67  for  working  with  graded  potentials.  The 
vessel  containing  the  electrolyte  has  a  tube 
fused  into  the  side.  Into  this  side  tube  the 
capiUarv  end  of  the  auxiliary  electrode  is 
inserted. 


Classuication  ov  thb  Mstals  vob  Elbotbo- 
▲nalytigal  pubposbs. 

Host  metals  can  be  deposited  satiaf aotocily  at 
the  cathode,  particularly  since  the  intioduotion 
of  the  mercury  cathode  and  of  the  graded  poten- 
tial methods.  Theoretioally,  by  grading  the 
potential,  it  should  be  possible  to  separate  any 
one  metal  from  another.  Indeed,  in  many 
oases,  this  can  be  done,  but  there  are  oases  in 
which  the  potential  diffeiences  at  which  two 
metals  can  be  deposited,  that  is  to  say,  the 
minimum  potential  at  which  they  will  both  be 
deposited,  lie  so  close  together  that  it  is  not 
possible  to  so  adjust  the  conditions  that  a 
separation  can  be  effected. 

Gboup  I. — Oopper,  silver,  merouiv,  gold, 
palladium,  rhodium,  platmum,  iridium,  bismuth, 
antimony,  tin,  (arsenic),  tellurium.  These 
metals  are  more  electronegative  than  the 
hydrogen  electrode,  and,  consequently,  oan 
theoretically  be  deposited  quantitatively  from 
aoid  solutions. 

Gboup  II. — Cadmium,  sine,  and  indium. 
These  metals  are  more  electropositive  than 
hydrogen,  but,  owing  to  the  supertension  of 
the  hydrogen  evolution  in  acid  solution,  it  is 
actually  possible  to  deposit  them  from  weak 
aoid  solutions. 

Gboup  IIL — Iron,  nickel,  cobalt.  These 
metals  are  more  electropositive  than  hydrogen, 
but,  as  the  supertension  of  hydiosen  is  very 
low,  these  metaJs  cannot  be  deposited  completely 
from  aoid  solutions.  They  oan,  however,  be 
deposited  from  acid  solutions  if  a  mercury 
oathode  is  employed. 

Gboup  IY. — ^The  metals  of  this  group  oan 
either  be  deposited  as  oxides  at  the  anode,  or 
as  oxides  at  the  cathode.  The  group  comprises 
the  following  metals:  lead,  thallium,  manga- 
nese, chromram,  molybdenum,  uranium.  Some 
of  them  oan,  however,  be  satisfactorily  deposited 
as  an  amakram  on  a  mercury  oathode. 

Gboup  v. — ^The  metals  of  this  group  are  the 
most  strongly  electropositive,  and  oan  only  be 
deposited  by  using  a  cathode  of  mercury ;  but 
even  then  it  is  not  possible  in  all  oases  to  obtain 
a  quantitative  separation.  The  metals  of  this 
group  are  aluminium,  glucinum,  calcium, 
strontium,  barium,  magnesium,  potassium, 
sodium,  lithium,  rubidium,  caesium. 

Gboup  VI. — ^These  are  all  anions,  and  their 
estimation  has  been  rendered  possible  mainly 
through  the  work  of  Edsar  Smith,  who  com- 
pletely deposits  the  metals  oy  means  of  a  mercury 
cathode  and  estimates  the  anions  by  titration  or 
other  appropriate  method.  The  most  important 
anions  analysed  by  this  method  are  F,  Cr,  Br', 
I',  SO4",    CO,",  Fe(CN),"",  Fe(CN),"',  PC/", 

NO3'. 

It  has  not  been  found  possible  to  analyse 
organic  anions  by  electrolytic  methods,  because 
they  are  either  daoomposed  or  various  reactions 
more  or  less  complicated  take  plaoe.  Thus, 
for  example,  when  the  acetate  anion  is  given  up 
at  the  anode,  ethane  is  produced,  which,  of 
course,  is  given  off  in  the  form  of  a  gas. 

Nalure  0/  Deposit. 

Sand  (Trans.  Chem.  Soo.  1907,  383)  has 
theoretically  and  practically  worked  out  the 
conditions  necessary  for  obtaining  adherent  metal 
deposits. 


316 


ANALYSIS. 


The  production  of  a  uniform  dnvasit  oyer 
the  electrode  depeuds  eutirely  upon  toe  relation 
between  polarisation  and  the  ^£LM.F.  required 
according  to  Ohm's  law  to  foroe* the  current  from 
one  part  of  the  solution  to  the  other  (Zeiteoh. 
Elektroohem.  1904,  462).  The  case  of  metals 
such  as  cadmium  and  zinc,  which  require  a 
higher  potential  for  their  precipitation  from 
most  of  their  solationa  than  hydrogen,  is  a 
question  of  supertenaion.  The  metals  can 
only  be  depo8tt(Ml  by  virtue  of  the  super- 
tension  which  is  required  to  liberate  hydrogen 
as  a  fas.  This  supertension  varies  with  the 
material  of  the  electrode,  and  may  even  vary 
at  different  parts  of  the  same  electrode,  owing 
to  different  states  of  its  surface.  Consequently, 
it  may  happen  that  the  metal  is  deposited 
on  a  portion  of  the  electrode  which  has  a  high 
supertension,  and  will  continue  to  grow  there ; 
but  at  rougher  parts  of  the  electrode,  where 
the  supertoniion  is  lower,  hydrogen  alone 
will  be  evolved.  This  is,  for  example,  particu- 
larly noticeable  in  the  case  of  zinc,  which, 
instead  of  beins  evenly  deposited  over  the 
surface  of  an  deotrode,  apparently  perfectly 
smooth  and  even,  often  comes  out  in  patches, 
parts  of  the  electrode  being  absolutely  free  from 
deposit.  Some  solutions  ^Iso  of  the  same  metal 
appeav  to  be  more  sensitive  to  variations  in 
the  quality  and  character  of  the  electrode  than 
others.  Thus  with  ordinary  electrodes  when 
the  potential  is  not  graded,  it  is  a  matter  of  the 
greatest  difficulty  to  obtain  an  adherent  deposit 
of  copper  when  the  electrolyte  is  sulphuric  add. 
On  the  other  hand,  with  electrolytes  of  potas- 
sium cyanide  or  nitric  add,  an  even  deposit  is 
readilv  produced. 

The  ncAvirt  of  the  depotU. — Electrolytic  de- 
pottts  may  be  spongy,  coarsely  crystalline,  or 
pndy  crystalline.  Tbib  last  is  the  only  form 
in  which  metals  may  be  deposited  in  order  to 
yidd  satisfactory  quantitative  results.  Sand 
considers  (2.e.)  that  spongy  depodts  are  most 
probably  due  to  the  metal  being  deposited  in 
the  form  of  an  unstable  hydride,  which  gradually 
decomposes  with  evolution  of  gas. 

The  difficulty  of  hydride  formation  is  got 
over  by  keeping  the  potential  of  the  electrode 
under  oontroL  Vigorous  stirring  of  the  deo- 
trolyte,  small  current  dendty,  and  the  presence 
of  some  oxidising  agent,  tend  to  keep  the 
potential  low.  But,  by  using  an  auxiliary 
electrode  and  rapid  rotation,  it  is  posdble  to 
obtain  metals  from  solutions  from  which,  under 
ordinary  ciroumstances,  they  cannot  be  de- 
podted. 

Copper. 

Copner  may  readOy  be  depodted  from  sdu- 
tions  which  contain  oondderaUe  quantities  of 
nitric  or  sulphuric  acid.  But  good  depodts  can 
also  be  obtained  from  cyanide  soluticms,  and  it 
is  posdble  to  employ  solutions  containing  an 
excess  of  ammonia. 

The  solutions  which  ^ve  the  best  results  are 
those  containing  nitric  acid  or  potasdum  cyanide. 
Indeed,  it  is  a  matter  of  condderable  difficulty 
to  obtain  satisfactory  results  in  presence  of  free 
sulphuric  add,  excepting  when  a  meroury 
cathode  is  employed,  ^r  stationary  work, 
either  the  gauze  flag  dectrode  or  the  cylindrical 
gauze  dectrode  is  to  be  recommended. 

Nitric  dcii.— About  1  gram  of  the  copper 


sdt  is  dissolved  in  about  140  c.o.  of  water  and 
5-10  0.0.  of  nitric  acid  (>P-p*  1*42)  added  to 
the  solution ;  that  is,  from  8  to  10  p.o.  of  the 
acid.  If  the  flag  dectrode  ii  employed,  usually 
about  120  C.C.  of  water  is  sufficient,  in  which 
case  proportionatdy  less  nitric  add  must  be 
used.  The  solution  may  either  be  dectrdysed 
at  ordinary  atmospheric  temperature,  or  heated 
from  45^-60^;  in  the  latter  case  the  time 
required  for  the  complete  depodtion  of  the 
metal  is  considerably  lessened.  The  best  CD. 
to  einploy  is  from  0*8  to  1  *2  amperes,  when  the 
E.M.F.  will  be  from  1  to  2-8  volts.  A  bright 
red  film  will  be  seen  to  flash  across  the  cathode 
dmost  immediatdy  the  circuit  is  completed. 
In  cold  solutions,  from  2^  to  3  hours  will  be 
required  to  completely  depodt  the  metal ;  with 
hot  solutions  the  rate  of  deposition  is  consider- 
ably accderated.  To  ascertain  when  the  whole 
of  the  copper  has  been  deposited,  withdraw 
about  1  C.C.  of  the  solution  by  means  of  a  pipette, 
transfer  to  a  test-tube,  make  alkaline  with 
ammonia,  then  acid  with  acetic  acid,  and  add 
a  few  drops  of  potasdum  f errocyanide ;  the 
formation  of  a  brown  precipitate  or  colouration 
shows  that  there  is  stiU  some  copper  left  in  the 
solution,  in  which  case,  of  course,  it  is  necessary 
to  continue  the  dectrolysiB  until,  on  further 
testing  with  the  reagent,  no  colouration  is 
produced. 

If  the  electrolysis  is  run  overnight  there  is  a 
tendency  to  form  nitrons  add  owing  to  cathodic 
reduction.  In  such  cases  a  small  quantity  of 
urea  should  be  added  and  the  electrbl3rsis  con- 
tinued for  about  half  an  hour.  Otherwise  a 
portion  of  the  copper  remains  in  solution.  The 
urea  decomposes  the  nitrous  add. 

Wtuhing  the  d^posiL — ^As  the  electrolyte  con- 
tains an  excess  of  free  nitric  add  in  wuich  the 
oopper  depodt  is  readily  soluble,  the  washing 
has  to  be  carried  out  with  caution.  Some 
workers  prefer  to  dphon  off  the  deotrolyte  with- 
out brealdng  the  oirouit,  and  to  run  in  water  at 
the  same  time,  until  the  ammeter  points  to  zero. 
The  current  is  then  cut  off  and  the  cathode 
removed^  finally  washed  with  distilled  water  and 
dipped  mto  a  beaker  of  absolute  alcohol  It 
is  then  dried  in  the  steam  oven,  and,  after  cooling 
for  20  minutes,  weighed.  When  the  gauze 
cylindrical  dectrode  is  used,  a  stoppered  funnd 
as  illustrated  in  Fig.  67  is  very  convenient. 

The  solution  is  drawn  off  until  only  about  one 
quarter  of  the  dectrode  is  immersed.  Distilled 
water  is  then  run  in,  and  the  operations  repeated 
until  the  ammeter  shows  zero.  By  operatii^ 
rapidly,  the  cathode  may  be  removed,  and,  3 
dipped  at  once  into  a  beaker  of  water  and  then 
waaned  under  the  tag  or  in  several  changes 
of  water  and  then  in  alcohol,  absolutdy  accurate 
results  can  be  obtained. 

The  depodt  obtained  from  nitric  acid  is 
bright  red,  and  generally  haa  a  more  or  less 
crystalline  appearance.  If  the  CD.  has  been 
too  high,  it  may  be  *  burnt,'  and  have  a  brown- 
ish appearance,  and  may  be  powdery  and  non- 
adherent. When  it  is  desired  to  electrolyse 
over-night— and  this  is  often  found  very  con- 
venient— a  CD.  of  from  0-2  to  0*3  of  an  ampere 
is  used.  It  is  generally  advisable  in  this  case 
to  add  more  nitric  acid,  because,  owing  to  the 
reducing  action  of  the  hydrogen  liberated  at  the 
cathode,  the  nitric  acid  becomes  converted  into 


ANALYSIS, 


317 


ammonia.    This  formation  of  ammonia  caoses  | 
the  deposit  to  be  spongy  and  of  a  bad  oolonr,  | 
when  it  is  difficult  to  wash  and  weigh.    For  nxn- 
ning  oyer-night  about  2  0.0.  extra  of  nitric  acid 
should  be  added  for  every  100  c.a  of  solution. 

The  deposits  obtaine^  with  sulphuric  add 
are  generally  not  satisfactory,  but  of  all  tiie 
copper  deposits  that  obtained  from  solutions 
containing  potassium  cyanide  is  the  most 
beautiful. 

Poteutium  cvanide. — ^The  colour  of  the 
deposited  metal  is  pinkish  red,  and  perfectly 
smooth.  Bnt^  from  other  points  of  view,  the 
deposition  from  cyanide  solutions  has  no 
advantage  over  the  deposits  obtained  from 
solutions  containing  nitric  acid.  The  copper 
salt  is  dissolved  in  about  30  or  40  cc.  of  dis- 
tilled water,  and  then  a  freshly  prepared  solution 
of  potassium  cyanide  added,  untu  the  precipi- 
tate first  produced  is  dissolved.  Slightly  more 
potassium  cyanide  than  is  necessary  to  dis- 
solve the  precipitate  should  be  used,  but  any 
considerable  excess  must  be  avoided.  GeneraUy 
epeakhig,  from  1  to  1*5  grams  of  potassium 
cyanide  should  be  used  for  every  gram  of  copper 
salt  taken. 

The  G.B.  employed  should  be  from  0-8  to 
1-2  amperes.  *Ae  KM.F.  required  in  cold 
solutions  will  be  found  to  be  about  6-6  volts ; 
in  warm  solutions,  from  4  to  6  volts.  The  whole 
of  the  cooper  is  deposited  in  2  to  2|  honrs. 

Bapia  mdhods. — ^By  employing  rotating 
electrodes,  either  rotating  anode  or  cathode, 
oopper  may  be  completely  deposited  in  a  few 
nunutes.  Thus  Sand,  hv  using  his  apparatus, 
was  able  to  oompletelv  deposit  the  copper  from 
0*25  gram  copper  sulphate  in  6  minutes,  the 
number  of  revcuutions  of  the  anode  per  minute 
bemg  about  800 ;  in  that  of  Fischer  the  copper 
from  0*3  gram  copper  sulphate  was  deposited 
in  10  minutes,  the  speed  of  revolution  being 
1000  to  1200.  In  the  one  case  a  rotating  anode 
was  employed  and  in  the  other  the  cathode  was 
rotated.  The  electrolyte  in  both  cases  contained 
free  nitric  acid.  Qyanide  solutions  give,  however, 
equally  satisfactory  results. 

Edgar  Smith,  by  employing  a  rotating  anode 
and  meroury  cathode,  nas  deposited  quantita- 
tively 0*789  gram  of  copper  in  10  minutes,  and  as 
mncn  as  0-3M5  sram  per  4  minutes,  the  solutions 
containing  sulpnuric  acid.  The  advantage  of 
the  meroniy  cathode  is  that  almost  any  eleotro- 
Ivte  can  be  employed  equally  satinactorily. 
mdeed,  the  pure  salt  of  the  metal  may  be 
dissolved  in  water  and  electrolysed  without  the 
addition  of  any  acid  or  other  electrolyte.  When 
the  whole  of  the  metal  has  been  deposited,  the 
solution  is  run  off,  and  may  then  be  titrated  in 
order  to  determine  the  anion,  e.g.  SO/'. 

Sflver. 

Silver  oan  best  be  deposited  from  solutions 
containing  potassium  cyanide.  From  solutions 
containing  other  electrolytes  it  is  apt  to  be  de- 
posited in  a  crystalline  featherv  form,  and  conse- 
quently does  not  adhero  well  to  the  cathode. 
Thero  is,  however,  a  tendency  for  the  results 
to  be  slightly  too  low  when  cyanide  solutions 
are  employed.  It  is  very  important  that  only 
the  purest  potassium  cyanide  be  used  in  making 
up  ike  solutions.  For  0-5  gram  of  a  silver  salt 
about  3-4  grams  of  potassium  cyanide  will 
usually  be  found  sufficient.     With  a  CD.  of  0*5 


to  1*0  ampere,  and  a  temperature  of  50^-60*, 
the  silver  will  be  deposited  m  from  1  to  2  hours. 
Using  a  cold  solution  and  ^ith  a  CD.  of  from 
0*2  to  0*35  ampere,  the  time  required  is  from 
4  to  4*6  hours.  The  deposit  should  either  be 
washed  by  siphoning,  or  the  electrode  must  be 
very  rapidly  removed  from  the  electrolyte  and 
dipped  into  water,  in  order  to  avoid  loss  by  the 
solvent  action  of  the  potassium  cyanide. 

With  rotating  electrodes  the  silver  can  be 
deposited  within  a  few  minutes.  By  using  an 
auxiliary  electrode  and  rotating  the  anode 
vigorously.  Sand  was  able  to  deposit  silver  item 
ammoniaoal  solutions  in  7  to  8  minutes. 

Smith,  b;^  usins  a  mereuiy  cathode  and 
rapidly  rotatmg  anode  deposited  0*2240  gram  of 
silver  from  silver  nitrate  in  4  minutes.  At  the 
commencement  of  the  operation  an  anodic 
deposit  of  silver  peroxide  was  obtained,  but 
after  a  minute  or  two  this  disappeured. 

Mereary. 

Iftany  methods  have  been  devised  for  pre- 
cipitating mercury  on  platinum  cathodes,  and 
some  of  them  give  quite  satirfactory  results. 
When  meroury  is  deposited  on  a  platinum  dish-, 
or  on  a  wire  game  electrode,  it  spreads  evenly 
over  the  surface  as  a  thin  metaUic  film,  which, 
however,  is  inclined  to  run  together  as  the 
amount  of  mereury  on  the  elecfiode  increases 
in  quantity.  After  the  merourv  has  been 
deposited,  the  electrode  is  washed  with  water 
in  the  usual  way,  then  in  absolute  alcohol,  and 
finally  in  absolute  ether.  The  last  traces  of 
ether  may  be  removed  by  blowing  di^  air  on 
to  the  electrode. 

On  no  account  may  the  mercury-coated 
electrode  be  heated.  If  the  electrode  is  washed 
once  in  00  p.c  alcohol,  and  then  placed  in  a 
beaker  of  anhvdrous  acetone  for  a  minute,  it 
may  then  be  dried  without  using  ether.  It  is 
always  advisable,  before  weighing,  to  place  the 
electrode  in  a  desiccator  for  20  minutes.  The 
desiccator  should  have  a  dish  in  it  containing  a 
Jittle  metaUic  mercury,  because  even  at  ordinarv 
temperatures  mereury  volatilises  to  a  small 
but  appreciable  extent. 

The  mereury  can  be  removed  from  the 
electrode  by  heating  in  the  Bunsen  flame,  but 
owing  to  the  tendency  for  electrolytically 
deposited  meroury  to  alloy  with  platinum,  the 
electrode  is  almost  invariably  marked  with 
black  stains,  and  a  slight  loss  in  weight  takes 
place.  For  this  reason  some  workers  prefer  to 
plate  the  electrode  with  copper  or  silver  before 
usin^.  These  difficulties  are,  however,  entirely 
eliminated  by  using  a  mercury  cathode ;  in  fact, 
it  is  strongly  recommended  to  employ  always  a 
meroury  cathode  when  dealing  with  meroury. 

Many  electrolytes  have  been  BUgffested,  and 
all  give  more  or  less  satiirfaotory  re^ts.  Thus, 
the  mercury  salt  may  be  dissolved  in  water 
and  electrolysed  in  presence  of  a  small  quantity 
of  sulphuric,  hydroonloric,  or  nitric  acid.  With 
sulphuric  acid,  from  1  to  2  c.c.  of  the  concen- 
trated acid  are  added  to  each  100  cc  of 
solution,  and  electrolysis  conducted  with  a 
CD.  of  0*3-0*8  ampere  per  square  decimeter, 
which  is  finally  increased  to  1  ampere  towards  the 
end  of  the  operation.  With  rotating  electrodes, 
currents  of  m>m  4  to  6  aznperee  per  square  deci- 
meter may  be  employed.  The  temperature  of  the 
electrolyte   may   be  60*-60*,   but  not  higher. 


318 


ANALYSia 


SomrtimeB,  owing  to  tlie  reduoinp;  action  of  the  ] 
hydrogen  given  off  at  the  cathode,  mercuronfl 
salts  are  precipitated.  The  addition  of  smaD 
quantities  of  ammoninm  persulphate  will  cause 
them  to  ^o  into  solution  again.  The  con- 
ditions with  the  other  acids  mentioned  are 
vefT  similar  to  those  required  for  sulphuric 
ado.  Potassium  cyanide  is  not  to  be  reoom- 
mendedy  owing  to  slight  solution  of  the  anode 
taking  place. 

Sodium  sulphide  gives  very  satisfactory 
results,  but  care  must  be  taken  to  emnloy  a 
very  pure  solution  of  salt.  From  25  to  30  co. 
of  the  concentrated  solution  of  sodium  sulphide 
are  required  for  every  100  c.c.  of  solution.  The 
solution  should  be  heated  to  about  06*,  and  for 
stationary  electrodes  a  CD.  of  0*1 5-0*26  ampere 
per  square  decimeter  used.  With  rotating 
electrodes  from  3  to  6  amperes  per  square 
decimeter  may  be  used. 

With  mercury  electrodes  rotating  anodes  are 
almost  invariably  used,  and  high-current  densities 
can  be  safely  employed.  The  whole  of  the  mer- 
cury can  be  deposited  in  from  16  to  25  minutes. 

Cinnabar  may  be  dissolved  in  afua  regia, 
the  solution  evaporated  to  drvness.  The 
residue  is  then  taken  up  with  water,  nltered  from 
gan^e,  and  then  directly  electrolysed  after  the 
addition  of  a  small  quantity  of  nitric  acid. 

Gold. 

Gold  may  be  deposited  from  its  solution 
in  cyanide  or  in  sodium  or  potassium  sulphide, 
or  in  ammonium  thiocyanate.  The  drawback 
to  using  potassium  cyanide  is  the  tendency  for 
the  anode  to  fq  into  solution.  But  with  low- 
current  densities,  this  only  takes  place  to  a 
small  extent.  The  solution  is  made  up  by 
adding  rather  more  than  the  quantity  necessary 
of  potassium  cyanide  to  bring  the  gold  salt  into 
a  dear  solution.  With  stationary  dectrodes 
a  CD.  of  0-0-^'8  ampere  is  employed  at  a 
temperature  of  5O*-60r,  the  metal  beingde- 
podted  in  the  course  of  2  to  3  hours.  With 
rotating  electrodes  a  current  of  about  3  amperes 
may  m  employed,  when  the  metal  will  be 
depodted  in  about  80  minutes. 

Sodium  stdphide. — From  20  to  25  co.  of  a 
saturated  solution  of  sodium  sulphide  are  used 
for  every  100  0.0.  of  solution,  with  a  CIX  of 
from  0*1  to  0*3  ampere  the  metal  will  be  de- 
posited in  from  4*5  to  5*6  hours.  With  rotating 
dectrodes  and  high-cunent  dendties,  the  results 
are  too  high,  owing  to  deposition  of  sulphur 
along  with  the  gold. 

Ammoniufn  thiocyanate. — 5  to  7  ^ms  of 
ammoninm  thioyoanate  are  dissolved  m  about 
80-90  CO.  of  water  at  70*  to  80*,  and  the  ^Id 
solution  run  dowly  in  with  constant  stirrmg. 
The  clear  solution  is  deotrolysed  at  a  temperature 
of  40*-50*  with  a  CD.  of  0-2-0*66  ampere,  the 
metal  being  depodted  in  from  1-6  to  2  hours. 
This  meth^  has  not  been  tried  with  rotating 
electrodes.  The  precipitation  of  small  quantities 
of  yellow  canarme  in  the  electrolyte  during 
electrolysis  does  not  interfere  with  the  reaction. 

£.  F.  Smith  obtains  good  results  by  dectro- 
lysing  a  gold  chloride  solution,  usine  a  mercury 
cath^e.  In  order  to  prevent  the  chlorine 
evolved  attacking  the  anode,  from  10  to  12  c.c. 
of  toluene  are  added.  The  time  required  to 
deposit  0*15-0*2  gram  of  gold  is  about  6  to 
7  minutes. 


Most  solvents  for  sold  will  al.«o  attack  the 
platinum  cathode.  Aqua  rema^  for  example, 
cannot  be  used  to  dissolve  tne  gold  from  the 
{datinum.  F.  M.  Perkin  recommends  a  dilute 
solution  of  potassium  cyanide  to  which  is  added 
4-6  C.O.  of  hydrogen  peroxide,  or  from  2  to  3  grams 
of  an  alkau  persulphate.  On  gentle  warming 
the  deposit  is  removed  in  a  few  seconds. 

2Au+4KGN+H.O,-2KAu(GN),+2KOH. 

Platinunu 

Like  gold,  platinum  can  be  depodted  from 
solutions  containing  free  mineral  aoids»  but 
unlike  gold,  which  from  these  solutions  is 
deposited  in  a  non-adherent  form,  it  may  be 
depodted  with  ver^  feeble  currents  in  a  naid 
and  reguline  condition.  With  high  currents  and 
with  stationary  electrodes  the  metal  is  always 
deposited  as  platinum  black.  With  a  current 
of  from  001  to  0-06  at  a  temperature  of  50*-60*, 
about  0*1  gram  of  platinum  can  be  depodted  in 
4*6  to  6  hours.  Julia  Langness  (J.  Amer. 
Chem.  Soc.  1907,  459),  by  using  a  rotating 
cathode,  deposited  0*2  ^m  of  platinum  from  a 
solution  of^  KsPtQ,  m  6  minutes.  But  the 
current,  17  amperes,  must  be  looked  upon  as 
excessive  for  anal^oal  purposes. 

Before  depodtmg  platinum  it  is  advisable  to 
coat  the  cathode  with  silver. 

RhodimiL 

This  metal  may  be  deposited  on  to  a  sQver- 
ooated  electrode  from  solutions  addified  with 
phosphoric  acid.    A  current  of  0*18  ampere 

15  used.  As  the  process  continues,  the  pmple 
colour  of  the  solution  gradually  disappears  and 
becomes  colourless,  when  the  depodtion  is 
finished.  With  a  rotating  anode  the  metal 
may  be  deposited  from  solutions  weakly  acidu- 
lated with  sulphuric  add  in  about  16  minutes 
with  a  current  of  8  amperes,  and  with  a  current 
of  14  amperes  in  6  minutes.  The  deposited 
metal  has  a  black  colour,  but  is  quite  ad- 
herent. 

Mladlum. 

In  order  to  obtain  a  dense  and  firmly 
adhering  deposit  of  this  metal  from  acid  solu- 
tions, it  is^  according  to  Amborg  (Zeit.  t 
Elektrochem.  1904,  386,  863,  and  Annaleo* 
1906,  236),  necessary  that  the  potential  should 
not  exceed  1*26  volts.  With  stationary  elec- 
trodes the  process  is  very  dow,  and  pdarisation 
at  the  anode  takes  place,  owing  to  the  formation 
of  oxy-  compounds.  On  the  other  hand,  by 
using  a  rotating  dectrode  and  solutions  of 
psUadium  ammonium  chloride  with  30  p.o.  by 
weight  of  sulphuric  add  and  a  CD.  of  from  0-& 
to  0*60  ampere,  as  much  as  0*3-0*9  gram  may 
be  depodted  in  from  3*5  to  6  hours. 

Jmia  Langness,  by  using  ourrents  ol  from 

16  to  17  amperes,  and  an  ammoniaoal  solution, 
has  obtainea  quantitative  depodts  in  from  3  to 
5  minutes. 

Antimony. 

This  metal  may  be  depodted  from  its  thio- 
salts,  particularly  sodium  thioantimonite,  a 
method  originally  suggested  by  Glsasen.  During 
the  electrolysis  there  is,  however,  a  danger, 
owing  to  the  deposition  of  sulphur  at  the  anode, 
for  sodium  thioantimoniate  to  be  formed,  and 
this  prevents  the  quantitative  depodtion  of 
the  metal.  A.  Fischer  (Ber.  1903,  2474)  recom- 
mends the  addition  of  potasdum  cyanide  to  the 


ANALYSia 


819 


electrolyte,  which  preyenti  ths  formation  of  the 
thioantimoniate,  thus: 

N,84+3KCN=3KCNS+Na,S. 

There  is  one  difficulty  when  flodinm  sulphide 
is  Dsed — ^the  results  obtained  are  usually  slightly 
too  hi^h.  This  is  due  to  the  occlusion  of  smaU 
quantities  of  sulphur  along  with  the  metaL 
For  this  reaion  large  quantities  of  metal  should 
not  be  deposited  by  this  method.  The  antimony 
salt  is  dissolved  in  0&-8O  o.c.  water  made  just 
alkaline  with  sodium  hydroxide,  any  precipitate 
being  ignored,  then  20-26  co.  of  a  fresh  saturated 
solution  of  sodium  sulphide  added,  and  2*5-3 
grams  of  potassium  cyanide.  The  solution  is 
then  electrolysed  at  from  30^-10^.  With 
stationary  electrodes  the  metal  is  deposited  in 
from  4*6  to  6  hours ;  when  rotating  electrodes 
are  used,  in  30  to  46  minutes. 

F.  M.  Perkin  and  H.  D.  Law  (Trans.  Faraday 
Boc.  i.  262)  recommend  neutral  tartrate  solu- 
tions. The  antimony  salt  is  dissolved  in  water, 
and  from  8  to  10  grams  of  ammonium  tartrate 
added ;  if  necessary,  the  solution  is  neutralised 
with  dilute  ammonia.  At  a  temperature  of 
from  70^  to  80^,  and  a  CD.  of  0-26-0-66  the  metal 
can  be  deposited  with  stationary  electrodes  in 
from  2'6  to  3  hours. 

Sand  (Chem.  Soc.  Trans.  1908,  1672)  dis- 
solves the  metal  in  20  ac.  of  hot  cone,  sulphuric 
addy  and  dilutes  the  cold  solution  to  ^  cc. 
The  solution  becomes  turbid  owing  to  hydro- 
lysis, but  this  disappears  during  the  electrolysis, 
and  does  not  affect  the  result.  The  auxiliary 
electrode  potential  is  kept  at  from  0*65  to  0*66, 
but  may  be  increased  to  0*75  toward  the  end 
of  the  process.  The  time  required  to  deposit 
0*35-0*45  gram  of  metal  is  from  20  to  36  minutes 
with  an  anodic  rotation  of  about  800  revolutions 
per  minute.  Small  quantities  of  hydrazine 
sulphate  (0*6-0*6  gram)  are  added  to  reduce 
any  antimonial  salts  which  may  be  formed. 

Bismuth. 

Until  the  advent  of  rotating  electrodes,  and 
particularly  of  the  method  of  graded  potential, 
oismuth  was  one  of  the^  most  difficult  metals 
to  deposit,  since  it  almost  invariably  came 
down  In  a  powdery  and  non-adherent  form. 
These  remarks  do  not  apply  to  the  mercury 
eathode.  According  to  Kollock  and  Smith 
(J.  Amer.  Chem.  S^.  27,  1539)  to  a  solution 
containing  about  0*2  gram  of  the  metal  as  nitrate, 
the  volume  of  which  should  not  exceed  12  cc, 
0*5  cc  of  strong  nitric  acid  is  added.  A  current 
of  about  4  amperes  is  passed,  and  the  whole 
of  the  bismuth  will  be  precipitated  in  from  12 
to  15  minutes.  The  anode  should  be  very 
rapidly  rotated,  so  that  the  meroury  may  take 
up  the  bismuth  as  it  separates,  otherwise  it 
mav  collect  in  a  black  mass  beneath  the  anode. 

Sand  {Chem.  Soc.  Trans.  1907,  373)  uses  a 
solution  containing  tartaric  acid ;  any  excess  of 
nitric  acid,  which  may  be  in  the  original  solution, 
is  removed  by  the  addition  of  sodium  tartrate. 
By  means  of  the  auxiliaiy  electrode,  the  cathode 
potential  is  maintained  between  0*63  and  0*9 
volt.  The  anod%is  rotated  at  800  revolutions 
per  minute.  In  one  case  the  amount  of  metal  in 
the  solution  was  0*2  gram,  2-5  cc  of  nitric  acid 
(1:4)  was  added,  and  8  grams  of  sodium  tartrate. 
With  a  current  varying  from  0*2  to  3  amperes  the 
xnetai  was  deposited  in  9  minutes. 


A.  Fisher  uses  an  electrolyte  containing 
for  each  0*5  gram  metal,  10  grams  of  potassium 
oxalate,  and  6  grams  of  Koohelle  salt.  By 
means  of  an  auxiliary  electrode,  the  cathode 
potential  is  kept  at  0*8  volt.  Temperature  of 
solution,  75*;  time  required,  11  to  16  minutes. 

Tin. 

Tin  can  be  satisfactorily  deposited  from  an 
ammonium  sulphide  solution.  Sodium  sulphide 
is  not  satisfactory ;  indeed,  tin  is  not  thrown 
out  from  strong  solutions  at  all.  Hence,  we 
have  here  a  method  of  separation  of  antimony 
and  tin.  If  the  tin  solution  is  acid,  it  is  first 
neutralised  with  ammonia,  and  then  sufficient 
yeUow  ammonium  sulphide  is  added  to  dissolve 
the  precipitate  and  form  a  dear  solution.  With 
stationary  electrodes  and  a  current  of  1-0-1-8 
amperes,  the  tin  will  be  deposited  in  from  3  to 
4  hours. 

With  rotating  electrodes  the  metal  can  be 
deposited  in  from  16  to  35  minutes,  depending 
upon  the  current  employed,  and  the  temperaturo 
of  the  electrolyte.  Oorrents  of  from  1*8  to  8 
amperes  have  been  successfully  employed. 

A  meroury  cathode  also  gives  very  ^ood 
results.  The  tin  salt  is  diraolved  in  dilute 
sulphuric  acid,  and  electrolysed  with  a  current 
of  from  2  to  5  amperes,  from  0*6  to  0*8  gram 
can  be  deposited  in  from  8  to  12  minutes. 

When  platinum  electrodes  aro  employed^ 
considerable  difficulty  may  be  experienced  in 
removing  the  defiosit.  The  simplest  method 
is  to  make  the  electrode  on  which  is  the  deposit, 
the  cathode  in  dilute  sulphuric  acid,  a  piece  of 
copper  wire  serving  as  cathode  Some  workers 
prefer  to  coat  the  electrode  with  copper,  and  then 
the  copper  with  tin,  the  tin  being  aeposited  from 
an  ammonium  oxalate  solution  ;  this  proceeding, 
however,  is  tedious. 

Telluriam. 

Finely  powdered  tellurium  is  dissolved  in  a 
few  cc  of  cone  sulphuric  acid.  The  white 
anhvdride  so  obtained  is  washed  with  a  little 
freshly  boiled  water  into  the  electrolysing  vessel, 
and  then  80  cc  of  a  10  p.c  solution  of  pyrophos- 
phoric  acid  or  sodium  pyrophosphate  auded. 
The  solution  is  then  electrolysed  with  a  CD.  of 
0*1  ampere.  Time  of  deposition,  4  to  6  hours 
When  a  rotating  electrode  is  employed,  the  time 
of  deposition  is  much  accelerated. 

Gbouf  II. — ^Zine. 

Zinc  is  rather  a  difficult  metal  to  deposit 
satisfactorily  and  quantitatively,  and  a  very 
large  number  of  methods  have  been  suggested 
by  different  workers.  Although  it  is  -f-0*77 
volt  more  positive  than  hydrogen,  it  can  be 
deposited  from  slightly  acid  solutions,  owing  to 
the  high  supertension  of  hydrogen  evolution 
from  the  surface  of  zinc,  the  supertension  of 
hydrogen  beinff  0*70  volt. 

With  zinc  it  in  advisable  ^always  to  employ 
rotating  electrodes.  The  electrodes  need  not, 
however,  be  made  of  platinum ;  nickel,  par- 
ticularly in  the  form  of  gauze,  answers  equally 
well. 

Price  and  Judge  (Trans.  Faraday  Soc  1907, 
88)  use  an  electrolyte  containing  sulphuric 
acid  which  must  not  be  more  than^jVand  sodium 
sulphate. 

It  is,  in  fact,  better  to  keep  the  normality 
of  the  acid  rathc^r  lower  than  one-sixth.  By 
starting  with  a  CD.  of  0*25  ampere  and  increasing 


390 


ANALTSia 


to  2*0  amperes  about  0*2  gram  of  metal  can  be 
deposited  m  40  minntea. 

Owing  to  acetic  acid  beins  mnoh  leas  dis- 
■ooiated  uian  sulphnric  acid,  solutions  containing 
comiderabla  <]nantitiee  of  this  acid  may  be  vsed. 
Thus,  Exner  (J.  Amer.  Caiem.  800.  1003,  806) 
deposited  0-25  gram  cine  with  a  onirent  of  4 
amperes  in  15  minutes.  The  electrolyte  con- 
tained 3  grams  sodium  acetate  and  0'30  p.c 
acetio  aoi(L  A.  Fischer  (Ghem.  Zeit.  1007,  25) 
takes  1  cc.  cone,  sulphnric  add,  8*5  cc.  cone, 
ammonia,  1*5  cc.  acetic  acid,  and  2*5  grams 
ammonium  acetate.  A.  Classen  (Quant.  Analyse 
d.  Elektrodhem.  1807,  156)  uses  a  solution  of 
potassium  oxalate,  the  sine  solution  is  added 
to  a  solution  of  from  4  t6  5  grams  of  potassium 
oxalate.  As  soon  as  the  electrolyBis  has  started, 
it  is  adyisable  to  add  a  few  cc.  of  a  1  p.o. 
solution  of  oxalic  acid.  Ammonium  salts  must 
be  absent. 

Kollock  and  Smith  use  a  mercury  cathode, 
and  a  solution  of  sine  sulphate  or  sine  sulphate 
addified  with  sulphuric  acid. 

Zinc  adheres  somewhat  firmly  to  platinum 
eleotrodesy  and,  if  left  on  for  some  time,  seems 
to  aUoy  with  the  dectrodes.  If,  however,  it 
is  remoyed  dhortly  after  the  decteolysis,  no  ill 
effect  Is  produced.  The  best  method  to  remove 
the  depodt  is  to  warm  the  dectrode  in  a  strong 
solution  of  sodium  hydroxide. 

Cadmtam. 

Although  cadmium  is  'dectropositive  to 
hydiogenH^  as  much  as  0*42  volt,  yet,  owing  to 
the  high  SQpertonsion  of  hydrogen  with  this 
metal,  it  Is  posmble  to  deposit  it  from  acid 
sdutions.  Owing,  however,  to  the  depolarising 
action  of  nitric  acid,  nitrates  should  not  be 
present;  on  the  other  hand,  small  amounts 
of  chlorides  do  not  seem  to  matter. 

Osdmium  may  be  deposited  from  solutions 
containinff  small  quantities  of  free  sulphuric 
add.  It  IS  usually  adviaable  to  add,  after  the 
bulk  of  the  cadmium  has  been  deposited,  the 
equivalent  amount  of  sodium  hydroxide  to 
neutralise  the  sulphuric  add  which  has  been 
set  free  through  the  depodtion  of  the  metal 
In  100  0.0.  of  sdntion,  1  cc.  of  concentrated 
sulphuric  acid  may  be  added  bdore  commencing 
the  electrolysis.  With  stationary  electrodes  ana 
a  current  of  0*1  to  0*35  ampere,  the  metal  is 
depodted  in  from  3  to  4  hours ;  with  a  rotating 
electrode  and  a  current  of  4  to  5  amperes,  the 
depodtion  Is  complete  in  20  minutes.  The 
depodtion  from  cyanide  solutions  is  the  simplest 
and  most  easy  to  carry  out.  A  solution  of 
potassium  cyanide  is  added  to  the  cadmium 
solution  until  the  precipitate  first  produced  is 
dissolved,  and  then  about  half  the  quantity 
already  added  is  run  in.  It  is  advisable  also  to 
add  about  2  cc.  of  a  normal  solution  of  sodium 
hydroxide.  With  stationary  dectrodes  and  a 
current  of  0*15-0*35  ampere  at  a  temperature 
of  50^,  the  deposit  is  complete  in  from  4*5  to 
5-5  hours;  with  rotating  dectrode  and  a 
current  of  from  5  to  8  amperes,  in  from  15  to 
30  minutes. 

Gboup  III.— Iron. 

It  is  not  often  that  the  analyst  requires  to 
deposit  iron  dectrolytically,  owing  to  the  very 
satisfactory  methods  of  titration  and  precipita- 
tion. Iron  cannot  be  deposited  from  acid  or 
even  from  neutral  salt  solution  upon  a  platinum 


electrode,  owins  to  its  being  so  much  mors 
dectropositive  than  hydrogen — 0*34  volt,  while 
the  supertendon  of  hydrogen  is  only  00MB  volt. 
KoUocxand  Smith  (Proc.  Amer.  PhiL  Soc  44, 
149,  and  45,  261)  have,  however,  succeeded  in 
depositing  iron  from  weak  acid  solutions  bj 
means  of  a  mercury  cathode,  the  iron  as  it  is 
depodted  amalgamating  with  the  mercury, 
llie  meUiod  dsMribed  By  these  authors  is  as 
follows : — 

Five  cc.  contained  0*2076  gram  of  iron. 
Three  drops  (40  dropeal  cc.)  oT  concentrated 
sulphuric  add  were  added  to  it,  when  it  was 
dectrolysed  with  a  current  of  3  to  4  amperes 
and  7  volts.  The  anode  made  from  500  to  900 
revolutions  per  minute.  The  iron  was  com- 
pletely depodted  in  7  minutes.  The  water 
was  then  siphoned  off  and  the  amalgam  washed, 
as  in  all  previous  cases,  with  alcohol  and  water. 

From  its  oxalate,  tartrate,  or  citrate  solutions, 
iron  may  be  satisfactorily  depodted,  but  in  aU 
cases  traces  of  carbon  are  depodted  along  with 
the  metaL  By  employing  low-current  dendties, 
the  amount  A  caroon  depodted  from  oxalate 
and  tartrate  solutions  is  negligible,  but  from 
citrates  the  results  are  almost  always  consider- 
ably too  high. 

Ammonium  oxaJale, — This  method  was  first 
suggested  by  Classen  (Zdt.  f.  Mektrochem.  i. 
288),  and  is  the  one  most  generally  employed. 
The  iron  solution,  which  snould  be  free  from 
chlorides  and  nitrates,  must  be  poured  into  the 
solution  of  ammonium  oxalate,  if  it  is  in  a 
ferrous  condition,  otherwise  a  predpitate  of 
ferrous  oxalate  may  be  formed  which  is  difficult 
to  dissolve.  With  ferric  salts  the  order  of 
adding  does  not  matter. 

Dissolve  5-7  grams  of  ammonium  oxalate 
or  add  ammonium  oxalate  in  a  small  quantity 
of  hot  water,  and  to  this  add  the  iron  salt  also 
dissolved  in  a  little  water.  The  solution  is 
then  made  up  to  th^  required  bulk,  and  dectro- 
jysed  with  a  CD.  of  from  0*6  to  1*2  amperes. 
Time  of  depodt  from  cold  solutions  and  with 
stationary  dectrodes,  4  to  5  hours;  from 
solutions  at  50*-60*,  in  2  to  2*5  hours.  As  the 
electrolysis  proceeds,  it  will  sometimes  be 
noticed  that  a  small  quantity  of  ferric  hydroxide 
separates.  This  is  due  to  the  solution  becomins 
dightly  alkaline,  owing  to  the  deoompodtion  of 
the  oxalate  by  the  current.  Should  the  hydrox- 
ide be  thrown  out,  small  quantities  of  oxalic  acid 
must  be  added. 

With  rotating  dectrodes  the  time  of  electro- 
lysis is  from  14  to  20  minutes. 

With  tartrate  solutions  the  results  are  equally 
good.  The  method  of  proceduro  is  similar  Ut 
that  described  for  oxalates,  ammonium  tartrate 
being  used  in  place  of  the  oxalate  The 
advantage  of  the  tartrate  method  is  that 
ferric  hydroxide  ia  never  deposited ;  consequently, 
it  ia  not  necessary  to  add  tartaric  acid,  and  thus 
less  attention  is  required. 

NlekeL 

Nickel  and  cobalt  are  difficult  to  determine 
by  general  andytical  methods,  but  they  can 
both  be  readily  and  accur^tdy  analysed  by 
dectrochemical  means. 

Although  many  methods  have  been  suggested 
for  the  deposition  of  nickel,  few  of  these  are 
of  practical  importance.  Most  of  them  depend 
upon  the  use  of  the  salts  of  oiganic  acids.     In 


ANALYSIS., 


S2l 


Bneh  oases  there  ia  a  tendency  for  traces  of 
carbon  to  be  deposited  with  the  metaL  The 
most  useful  and  generally  applicable  method 
for  depositing  nickel  is  that  of  Fresenios  and 
Bergmann  (Zeit.  f.  Anal.  Ghem.  33,  0),  in  which 
the  double  salts  of  potassium  and  nickel  or 
ammoniam  folphate  together  with  excess  of 
ammonia  are  used. 

The  nickel  salt  is  dissolved  m  water  and 
mixed  wiUi  an  aqueous  solution  of  from  4  to  6 
srams  of  ammonium  sulphate,  and  from  30  to 
35  0.0.  of  strong  ammonia.  If  more  than  I  gram 
of  the  ni<^el  salt  is  employed,  larger  quantities 
of  ammonia  should  be  aaded.  As,  however, 
large  quantities  of  strong  ammonia  are  apt  to 
contaminate  the  atmosj^ere,  it  is  bett^  to 
work  with  smaller  quantities  of  niokeL  Nitrates 
should  be  absent,  as  their  presence  considerably 
retards  the  rate  of  deposition.  With  a  current 
of  1-1-5  ampere  jper  sq.  dcm.,  the  metal  will 
be  deposited  in  m>m  2  to  2*5  hours;  at  a 
temperature  of  50*-60*',  the  time  will  be  from 
1-5  to  2  hours;  with  rotating  electrodes,  in 
from  15  to  30  minutes,  depending  upon  the 
conditions  and  the  form  of  apparatus.  The 
metal  is  usually  deposited  as  a  brilliant  plating 
on  the  electrode.  The  deposit  is  at  times  some- 
what difficult  to  remove,  and,  owins  to  its 
appearance  being  rather  like  polished  Atinnm, 
it  IS  not  always  easy  to  ascertain  whettier  it  has 
been  oompletdy  dissolved  off.  The  best  method 
of  removing  the  metal  is  to  warm  the  electrode 
in  moderatdy  strong  sulphuric  or  nitric  acid. 

Other  methods  employed  are  the  double 
oxalate  method  of  Cfassen  and  Von  Reiss 
(Ber.  14,  1622);  ammonia  and  ammonium 
borate,  bv  F.  M.  Perkin  and  W.  a  Ftebble 
(Trans.  Faraday  Boo.  1904,  103).  Kollock  and 
Smith  (^oc.  Amcr.  Phil.  Soo.  45,  262)  have 
used  a  mercury  cathode  successfully,  the  time 
of  deposition  Ming  from  7  to  20  minutes.  An 
amalsam  of  40  grams  mercury  and  1  gram 
niokd  has  the  consistency  of  soft  dough,  and  is 
bright  in  appearance. 

Cobalt 

Cobalt  may  be  deposited  from  an  ammonium 
sulphate,  ammonium  hydroxide  solution  similai 
to  that  used  in  the  case  of  nickel.  But  as  a 
rule  the  resulte  obteined  aro  too  low,  owing  to 
the  tendency  for  peroxide  to  be  formed  on  the 
anode. 

F.  M.  Perkin  and  W.  C.  Prebble  (Trans. 
Faraday  Soo.  1905,  103)  use  a  solution  con- 
taining dihydrogeo  sodium  jj^hosphate  and 
phosphoric  acid.  The  solution  is  made  up  bjy 
adding  2  co.  of  a  5  p.o.  solution  of  phosphono 
acid  to  the  solution  of^the  cobalt  salt  in  70-80  co. 
water  and  then  20-25  co.  of  a  10  p.o.  solution 
of  dihydrogen  sodium  phosphate.  The  elec- 
trolysis should  be  commenoed  cold  with  a 
current  density  of  0*2-0*3  ampere  per  sq.  dcm. ; 
after  about  50  minutes  the  solution  is  warmed 
to  5(^  or  60^,  and  the  current  increased  to  1*2 
ampere.  If,  as  often  happens,  some  peroxide  is 
deposited  on  the  anode,  it  can  be  removed  by 
the  addition  of  0*2-0*3  gram  of  hydroxylamine 
sulphate.  After  the  solution  has  become 
colourless,  about  1  cc  of  A/ 1 -ammonia  should 
be  added.  The  time  necessary  with  stetionarv 
electrodes  is  from  4  to  5  hours.  The  deposit 
is  exteemely  bright,  resembling  pobshed 
platinum. 

Vol.  L— T. 


The  only  methods  which  have  beoi  tried 
with  roteting  electrodes  are  solutions  containing 
ammonium  aoetete  and  solutions  with  sodium 
formate.  With  currento  of  8  amperes,  L.  Kol* 
look  and  E.  F.  Smith  (J.  Amer.  Chem.  Soc 
29,  797)  succeeded  in  depositing  0*8  gram  of 
oobalt  in  from  30  to  40  minutes. 

Gbovf  IV.— Lead. 

Owing  to  its  ready  oxidisability,  it  is  difficult  to 
deposit  lead  satisfactorily  on  the  cathode.  Except 
in  cases  of  separation  from  other  metals,  indeed, 
it  is  of  no  advantage  to  deposit  it  at  the  cathode. 
Sand  has,  however,  found  it  a  convenient  method 
to  separate  lead  from  cadmium  and  biBmnth 
(Ghem.  Soo.  Proc  22,  43). 

From  dilute  solutions  of  nitrio  acid  lead  ia 
partially  deposited  as  metal  on  the  cathode, 
and  partially  as  peroxide  at  the  anode  It  is 
therefore  necessary  to  have  about  20  cc  of 
nitric  add  (1 : 4)  to  every  100  cc  of  electrolyte. 
Arsenic,  manganese^  selenium,  and  bismuth 
should  be  absent,  and  according  to  Vortmann 
(Annalen,  351,  283),  antimony,  silver,  meroury, 
zinc,  iron,  oobalt,  aluminium,  and  the  alkali 
metals  also  cause  the  resulte  to  be  high.  CJhromio 
acid  should  also  be  absent,  and  phosphorio  acid 
retards  the  deposition.  The  lead  salt  is  dis- 
solved in  water,  and  from  25  to  30  cc  of  stroog 
nitric  acid  added.  The  electrodes  used,  whether 
stetionaiy  or  roteting,  should  be  roughened  by 
the  sand  blast.  With  stetionary  electrodes 
and  a  current  of  horn  1*3  to  1*8  ampere  at  a 
temperature  of  60*-70*,  the  deposition  wiU  be 
complete  in  from  1  to  1*5  hours.  At  the  com- 
mencement of  the  electrolysis  a  yellowish 
deposit  is  obteined  which  becomes  orange  or 
red,  and  finally  dark-brown  or  black. 

With  roteting  electrodes,  the  time  of  deposi- 
tion is  from  10  to  25  minutes. 

At  the  end  of  the  electrolysiB  the  electrode 
is  well  washed  by  plaoins  it  in  hot  water,  then 
washed  with  alcohol  ana  ether,  and  heated  to 
220*  in  the  air-bath  for  an  hour.  It  must  be 
cooled  in  a  desiccator;  the  weisht  of  the 
deposit  is  multiplied  by  the  factor  0*866. 

The  best  method  to  remove  the  deposit  from 
the  eleotrode  is  to  warm  it  with  equal  volumes 
of  nitrio  acid  and  water  to  which  4^  grams  of 
glucose  has  been  added. 

Lead  does  not  give  satisfactory  resulte  with 
a  meroury  cathode 

Bbrnganesf. 

Manganese  can  only  be  deposited  as  oxide 
at  the  anode.  It  is,  however,  mnoh  more 
difficult  to  deal  with  than  lead,  as  the  deposit 
is  apt  not  to  adhere  welL  It  is  absolutely 
essential  to  employ  roughened  electrodes. 
Mineral  acids  cannot  be  employed.  Hie  most 
satisfactory  electrolyte  is  one  containing  am- 
monium acetete,  and  Engels  (Zeit.  Elektr^hem. 
u,  413)  has  shown  that  the  addition  of  small 

3uantities  of  chrome  alum  helps  to  cause  the 
eposit  to  adhere  more  firmly,  probably  owing 
to  a  depolarisinff  effect.  The  manjtanese  salt 
is  dissolved  in  40-50  cc  of  water,  ^10  grams 
of  ammonium  acetate  added,  and  the  somtion 
electrolysed  at  a  temperature  of  75*-80*,  with 
a  current  of  0-6  to  1  ampere.  The  depo- 
sition will   be    complete   in    from    1*5   to  2 

hoUTiH. 

With  rotating  electrodes  the  time  will  be 
about  30  minutes.    In  this  case  it  is  as  well  to 

Y 


add  10  CO.  alcohol  to  prevent  frothing  (J.  Roator, 
Zeit.  f.  Mektiocbem.  10,  063). 

This  beat  way  to  Moertaia  if  all  the  numguieee 
hu  been  deporited,  ia  to  emploj  the  per- 
DUuisuiBite  teet.  Withdraw  1  or  2  □.<).  of  the 
iolulioii,  edd  3  o.e.  oono.  nitric  Mid,  and  abont 
1  gram  of  red  lead.  Boil  for  a  minute  or  two 
and  dilute;  A  pink  cdouration  indioatea  that 
the  whole  of  the  manganeM  hu  not  been 
removed. 

When  all  tlie  manKoneea  baa  bean  depoaited, 
the  cleotrode  ia  watbed  a*  nioa],  and  then 
■tiongly  heated  in  order  to  oonvert  Uie  hydnted 
uaosaneae  peroxide  into  trimanganese  totoozida 
Hn,0,.  It  ia  neoeBsary  to  heat  until  the  Uaek 
depoeit  beoomea  a  dull  onuiM  red.  The  w^ht 
of  the  depoail  multiplied  dj  0'T2  gives  the 
weight  tit  mctallio  manganeae. 

ChnBlnm. 

Thia  metal  oannot  be  depodted  on  the 
anode  as  peroxide ;  neither  under  ordinary 
oondiliona  u  it  pooaible  to  obtain  a  cathode 
depodt.  Ktdlock  and  Smith  (Tnui*.  Amer. 
Chem.  Boo.  27,  190S,  liOli)  hare  mooeeded  in 
depositing  it  in  the  form  ol  aa  amalgam  by 
employiDg  a  menmry  osthode.  The  deotrolyte 
oonaitted  o(  dilute  lulphnria  aeid.  With  a 
oarrent  ot  1-3  amperea  0-12  gram  waa  depoaited 
in  20  minutoa.  Thia  me^od  ii  oeefiil  for 
aeparating  ohrominm  from  alnmininm,  which 
latter  metal  i«  not  depoaited  aa  an  amalgam. 

CQaaaen  (Bei.  xxvlL  2060}  ozidiaes 
ohromio  aalta  to  Dhromatee  in  an  ammouinm 
oxalate  aolution.  Thia  method  ia  naefnl  for 
aeparating  ohromiam  from  iron,  niokel  and 
eobalt,  and  in  the  anolyiii  of  chromium  ateela 
and  of  chrome  iron  ore.  The  ohromio  aoid  pro- 
duoed  can  be  eetimatiNi  iodometrioatl)'  or  by 
pieoipitation  aa  lead  or  barium  ohromate. 

Tbe  aolntioD  oootaining  the  iron  and 
chromium  oalt  ha*  ezoeea  of  ammooiam  oxalate 
added  to  it,  and  if  free  mineral  acid  is  preeent  is 
neutraltaed  witii  ammonia.  It  is  then  electro- 
lysed, wbea  the  iron  it  depoaited  at  the  cathode 
and  the  ohrominm  oxidised  to  chromate.  The 
iron,  when  depoaited  in  presence  of  cbromiom 
■alta,  is  nsaally  very  brilliant  like  polished 
plotioum.  When  oU  the  iron  ia  deposited,  the 
•datkm  la  removed,  the  iron  depoalt  dried  and 
wB^ed,  and  the  ebrominm  determined.  If 
the  whole  of  the  chromic  salt  baa  not  been 
oxidiaed  during  the  depoaition  of  the  iron,  the 
eolation  is  again  eleetrolyaed.  By  naing  a 
rotating  anode  it  1«  possible  to  comploMy 
oxidise  010  ^m  of  a  ohromio  salt,  such  oa 
Ck,(SO,),  or  Cr,Cl,  in  90  minnt«a,  the  volume 
of  the  solution  being  120  o-o.  and  the  amount 
of  ammonium  oxalate  10  grams.  The  eleotro- 
Ivte  should  be  heated  to  SW,  and  a  onrrent  of 
from  0  to  OS  amperea  employed  (Elektnm- 
olytisobe  SchnellmeChoden,  p.  ISO). 

Uranluin. 

Uranium  is  deposited  at  the  eatiiode  as 
oxide  from  solutions  oontaining  aoetie  acid  or 
ammonium  carbonate.  The  deposit  oonsista 
of  Q,0„3H,0.  At  the  end  of  the  operation 
this  is  heat«d  atrougly  to  convert  it  into  D  " 

WhertT  and  Smith  (Trans.  Amer.  Chem. 

29,  806),  by  using  a  rotating  cathode  and  an 
electrolyte  oontaiiung  in  120  0.0.  Z'5-0'0  gram 
sodium  acetate,  deposil«<l  0-20  gram  of  orsninm 
in  from  IS  to  30  mmntea,  th«  onrrent  employed 


being  8-5  amperea,  the  electrolyte  being  either 
cold  or  heated  to  CO". 

Molrbdmim. 

From  aotntions  oontaioing  dilute  anlphurio 
acid,  molybdenum  ean  be  depoaited  as  peroxide 
at  the  oatbode,  but  Uie  depoait  oannot  be 
weighed  as  such.  Wherry  and  Smith  (Tcaua. 
Ams.  Chem.  Boo.  29,  BOO],  therefore,  ondlae  it 
by  means  of  nitria  add  and  weigh  aa  HoO|. 


llany  methods  have  been  suggested  for  t^e 
eleotrolf  tie  analyiia  of  tballium,  bnt  only  one  oan 
be  oonndered  satisfactory,  and  that  is,  by  usins 
a  metonry  cathode.  By  depositing  the  meW 
into  pure  mercury,  it  ia  foond  that  portions  are 
lost  on  weighing  ;  but  if  the  mercury  containa  a 
amall  quantity  of  sine,  this  is  not  the  case. 
Bmith  moommends  to  deposit  the  sine  and 
mercury  nmultaneously.  in  order  to  do  t-lii" 
a  defimte  volnme  of  linc  sulphate  solution  of 
known  strengtli  is  added  to  the  solution  before 
electrolysis.  The  electrolyte  eonsiits  of  dilute 
sulpburio  add.  The  amount  of  line  necessary  to 
prol«at  Ae  thallium  is  very  small,  and  need  not 
be  more  than  O-OOl  gram.  With  a  onrrent  of 
S  amperes  it  is  poesible  to  deposit  aa  much  as 
O'Z  gram  In  about  10  minut«a.  It  is,  however, 
advisable  to  electrolyse  for  s  longer  time. 

Gbouf  V. — Sodium. 

E,  F.  Smith  (Trans.  Amw.  Chem.  Boo.  SO, 
1003,  BOO)  was  the  first  to  show  that  the 
metais  of  the  alkali  group  could  be  analysed 
eleotrolytically.  The  method  is  baasd  on  the 
removal  ot  the  halogen  onion  of  the  metal  by 
causing  it  to  unite  with  silver,  the  alkali  metal 
remaimng  in  the  solution  as  hydroxide  is  deter- 
mined by   titration : 

increase  m  w« 
the  silver  aao 
halogen  oon  I 
determined. 


ontw 
(Kg. 

oonsL 

cell 

as) 

ts    of 

a  crystallising  dish.  11 

0  cm 

deep; 

a  beaker 

ANALYSIS. 


923 


cm.  high,  with  the  bottom  cat  o£f,  iapkoed  inaida 
and  xwts  on  a  triangle  ol  glaai  rod  maoed  on  the 
bottom  of  the  aystoDiamg  diah.  The  beaker  is 
kept  in  poation  in  the  middle  of  the  dkh  by 
means  off  three  rabber  stoppers  fitted  ladiany 
between  it  and  the  onter  <ush.  Two  compart- 
ments are  thus  formed,  which  an  sealed  off  fay 
means  of  memny.  In  the  outer  compartment 
there  is  a  ring  consisting  of  six  tarns  of  stoat 
nickel  wire^  provided  with  three  legs  dipping 
into  the  menmry  and  serving  to  maintain  the 
fewest  winding  of  the  nickel  aboat  1  cm.  above 
the  sarfaoe  ci  the  mercary,  when  saffident  is 
placed  in  the  dish  to  seal  off  the  two  oompart- 
mentSb  By  means  of  a  platinam  wire  passing 
throosh  a  glass  tube  the  meroar^  is  made  the 
oathoda  The  anode  consists  of  two  discs  of 
platinam  gaosa  heavily  plated  with  silver. 

Pare  meroaiy  moist  be  ased,  and  the  oell 
most  be  kept  sorapakrasly  dean.  Before 
starting  the  oeU,  meroaxy  Ss  poored  in  so  that  its 
level  is  aboat  3  mm.  above  the  lower  edge  of 
the  inside  beaker.  The  sohition  to  be  eleotro- 
lysed  is  then  pot  into  the  inner  oompartment. 
In  the  ooter  one  enoagh  distilled  water  to  oover 
the  nickel  wire  is  placed*  and  to  this  I  ao.  of 
a  satozated  solation  of  cominon  salt.  By^  this 
arrangement  the  amalgam  formed  in  the  !nner 
compartment  is  immediately  decomposed  in 
the  ooter  one.  The  sodium  chloride  serves 
merely  to  make  the  Uqoid  a  oondactor,  so  that 
the  action  may  proceed  more  rapidly  at  the 
commencement.  Unkss  this  is  done,  the 
amalgam  is  not  entirely  decomposed  in 
the  ooter  compartment,  becaose  pare  water 
does  not  attack  it  rapidly  enoagh  to  prevent  the 
partial  decomposition  in  the  inside  celL  After 
the  electrolysis  is  complete,  the  entire  contents 
of  the  cell  are  pooiea  into  a  beaker,  the  oeU 
rinsed,  and  the  alkali  titrated.  After  titration 
the  meroaiy  is  washed,  the  water  decanted,  and 
the  metal  poored  into  a  large  separating  funnel 
from  which  it  can  be  drawn  off  dean  and  dry. 

The  annexed  table  gives  the  results  which 
were  obtained  by  Hildebrand. 

The  weighed  gauze  anode  is  damped  to  the 
■halt.  The  latter  is  lowered  into  the  cell  till 
the  lower  gaoae  is  aboot  0  mm.  from  the  surface 
of  the  meroozy.  The  most  convenient  speed 
for  the  motor  is  about  300  revolutions  per 
minutei  The  anode  does  not  require  washing, 
as  the  water  after  deotrolysis  is  pure.  It  may 
be  at  once  dried  in  the  steam  oven. 


Time : 

Yolts 

Sodium  in 
grami 

Chlorine  in 
grami 

.Mins. 

Freseat 

7oand 

Present 

IToand 

80 
46 
40 
45 
80 
56 

4-0-2-5 
8'6-£-5 
8-5-8-0 
4-0-8-5 
4-0-2-5 
8-0 

0-50-O-02 
0-84-0-01 
0-60-0-01 
0*05-0-01 
0*78-0*02 
0-20-4>*O2 

0-0461 
0-0481 
0-0461 
0-0461 
0-0461 
0-0461 

0-0450 

0-0708 
0-0708 
0-0708 
0-0708 
0-0708 
0-0708 

0-0704 
0-0706 
0-0704 
0-0716 
00718 
0-0700 

By  means  of  this  apparatus  the  halogen 
salts  of  the  alkali  metals  can  be  analysed.  Also 
the  halogen  salts  of  barium  and  strontium.  In 
fact,  any  anion  with  any  metal  which  will  unite 
with  silver  to  form  an  insoluble  salt  can  be 


ana^sed,  provided^  of  oooae,  that  the  metallic 
salt  Is  sc^Ue,  and  that  the  metal  will  form  an 
amalsam  with  tiie  merouiy.  In  the  ease  of 
the  aJxali  metals  and  of  strontium  and  barium, 
the  hydroxides  <tf  which  are  soluble  in  water, 
the  oations  are  analysed  by  Utntion.  With 
other  metals  forming  amalgams  which  are  not 
readily  deoompoeed  this  method  of  analvsia 
is  not  to  be  recommended,  because,  in  the  first 
place,  the  considerable  quantity  of  mercury 
neoeesary  Is  mconveuient  to  weigh,  and,  seoondlv, 
it  requires  to  be  kept  veir  pure,  consequently 
the  continual  purification  of  such  large  quantities 
of  mercury  would  be  tiresome. 

AnafytU  of  anient  whtn  united  wOh  Aeoey 
metols.  The  80«  anion  in  such  salts  as  oopper 
sulphate  may  be  analysed  bv  dectrolvihuj  a 
known  weight  of  copper  sulnhata  dissolved  in 
water  with  a  merouiy  oathoae  and  a  plathnnm 
anode  as  already  deooribed.  When  all  the  oopper 
has  been  deposited,  the  solution  is  siphoned  off, 
the  an»^lg«.m  washed  with  water,  and  the  wash 
water  ad^d  to  the  original  sdution.  The  whole 
of  the  anode  solution  is  then  titrated  with  N' 
sodium  hydroxide.  The  copper  can,  of  oouiae, 
be  estimated  by  weighing  the  amalgam. 

Separatum  of  sodium  from  cakium  and 
moffnisium.  When  caldum  and  magnedum 
salts  are  dectrolysed  in  Hildebrand's  apparatus, 
it  is  found  that  the  hydroxides  of  these  metals 
are  precipitated  in  the  inner  cdL  It  has  therefore 
been  found  posdUe  to  separate  sodium  from 
these  metds  oy  means  of  this  apparatus.  The 
outer  odl  contains  all  the  sodium  as  hydroxide, 
and  the  sodium  can  be  determined  by  titration. 
The  analytical  results  obtained  are  praotioaUy 
theoretioaL 

In  a  similar  mannei  barium  can  be  separated 
from  caldum  and  magnedum. 

Arsenic. 

It  is  not  posdble  to  depodt  arsenic  quantita- 
tivdy  in  the  metalloid  condition,  neither  can  it 
be  precipitated  at  the  anode  as  oxidsu  Arsenic 
is  rea^y  converted  by  nascent  hydioffen  into 
arseniuretted  hydrogen,  its  gaseous  nydride, 
AsH, ;  hence,  electrdytio  methods  of  analysis 
are  not  usually  employed  for  analysing  arsenic 
compounds,  ft  is,  however,  posdble  to  estimate 
very  small  quantities  of  arsenic  contained  in 
food,  Ac,  by  dectrolysis.  The  process  consists 
in  evolving  dectrolvtio  hydrogen  in  presence  of 
the  arsenic,  whereby  the  arsenic  is  converted 
into  arseniuretted  hvdrogen.  The  gaseous 
hydride  is  then  passed  through  a  glass  tube, 
heated  by  a  small  Bunsen  burner,  ss  m  the 
Marsh  apparatus,  wheireby  the  arsenic  is  de- 
podted  upon  the  tube  in  the  form  of  a  minor, 
in  order  to  estimate  the  amount  of  the  arsenic, 
the  mirror  is  Uien  oompaied  with  nuirors  pre- 
pared hrom  known  quantities  of  arsenic. 

In  1812  Fischer  (Gilbert's  Ann.  42,  92)  sug- 
gested  the  employment  of  the  deotric  current 
to  detect  the  presence  of  very  small  Quantities  of 
arsenia  It  was  again  suggested  dv  Bloxam 
(Quart.  Joum.  Chem.  Boo.  1861,  13,  12  and 
338)  in  1861,  but  the  apparatus  had  several 
disadvantages,  and  ilever  came  into  practical 
use.  Since  then  various  modifications  have  been 
suggested  by  different  authors,  and,  hi  1903, 
Thorpe  (Joum.  Chem.  Soc.  1903)  describes  a 
new  form  of  apparatus  which  has  been  success- 
fully employed  for  the  analysis  of  traces  of 


Fio,  69. 

gla»  cylindrical  vaaiel,  which  is  open  at  the 
end,  and  fito  into  »  Pukal  poious  oelL  The 
poroos  oell  ii  niTTOnnded  by  the  anode,  and 
Etands  in  an  oDter  veeaeL  The  npper 
portion  of  the  cylinder  li  open,  and  has  a 
eround  neck  for  the  iiuertion  oi  the  drying  tuba 
nlled  with  anhydrouB  oloiam  chloride,  uid 
also  oairiea  the  fmmal,  which  is  fitted  with  a 
tap,  through  which  the  solution  to  be  teeted  ia 
run  in.  A  capillary  tube  ia  connected  to 
the  end  of  the  calcium  chloride  tube.  The 
middle  of  tlii*  tube  IB  heated  by  meani  of  the 
■mall  Bunsen  bomer,  and  ia  suironnded  whMe 

>tUie 

ia    placed  in  a  vettti 
-.     „    .-  .  o  prsTaot  undue  heating 

dnring  eleotrolysiB. 

MMod  of  aorldng.     The  ftppantiu  ia  oam- 
fnlly  washed  wiUi  dutiUed  water.    The  outer 
oeU  ■  ia  filled  with  dilnte  nlphiuia  acid  (30  p.c.). 
V  oeB.    (The  potoua  oell  ahouli 


Msenic,  Thorpe  conaidBra  It  advisable  to  take  a 
portion  of  the  foadatufl— anenio  free— and 
mix  it  with  the  Icnown  quantity  of  BMemo  before 
prooeediug  to  deotrolyae  it.  The  ttaudard 
minon  are  thua  prepared  oudar  the  aame  con- 
ditiona  aa  those  under  which  the  nwpeeted  food. 
ttufl  ia  teated. 

8.  B.  Trotman  (J.  Soo.  Chem.  In±  23,  IT7) 
recommends  the  adoptioa  of  a  parchmeoi 
memlxane  in  place  of  the  porona  Pukal  oell, 
as  he  oonaiden  this  deorcaoM  the  reaistaiioe, 
and  thua  make*  tbe  apparatua  more  eeoMtive. 
It  ia,  liowever,  not  ao  oonveniant  to  uao. 

Sand  and  J.  B.  Hackford  (Chem.  Soo.  Traim. 
B6,  1018)  D<i  the  parohmrait  memlxaae,  bat 
thev  idao  employ  a  heafy  lead  cathode  aod  a 
lead  anode.  Their  apparatua  ia  thneby  much 
oheaper  than  that  used  by  Thorpe,  and  ia  eaid 
to  be  equally  aoooiate. 

MetaUk  BtparaHmu. 

k  large  number  of  aeparationa  of  metal*  by 
cJectrolytic  met^oda  have  been  worked  out, 
but  in  many  caaea  a  purdy  ohetoical  prooedura 
or  a  combination  of  electrolytic  and  chemical 
methoda  ia  easiet.  There  are,  however,  oaae* 
in  which  utiafacfory  aod  rajrid  elecbolytio 
aeparationa  can  be  carried  out.  A  few  of  the 
more  important  are  given  below. 

Copper  from  ni/ikd.  By  employing  a 
rotating  anode  with  an  auxiliary  electiiode, 
and  maintaining  the  catliode  potential  at 
0-T-0-7G  volt,  ooppet  can  be  deposited  from 
Bolutiona  containing  aulphuiio  acid.  The  acdu- 
tion  i*  then  made  tdkaline  with  ammonia,  when 
the  nickel  oan  be  deposited.  If  the  oathode 
potential  ia  not  regulated,  imall  ouantitie*  ai 
the  niokel  are  deposited  along  ivith  the  eoppcc. 

Ezner  (J.  Amer.  Chem.  Soc.  25,  806)  find* 
that  by  employing  a  solution  containing  nitric 
acid  and  ammonium  nitrate  (volume  of  solution 
HHOu  0.2G  CO.  ;    3  giam  NH^NO.) 


aoaked  in  dilute  ■ulphurio  acid  for  about  half  |  and  uaing  a  rotating  ant 
au  hour  before  being  used.)    Aa  soon  aa  all  tht   deposit  as  much  as   0'2is 

oooneetiona   are   made,  the   Buosen   bonier   i«'  20  minutes;  the  nickel,  w ^ ^ . 

placed  in  position,  but  not  lighted,  and  the ,  weight,  remains  in  acdntion,  and  can  be  aner- 
ouirent  ia  passed.     A  cnirent  of  about  S  ampere*   wards  doposit«d. 

ahouJd  be  used  ;  the  eeoapiitg  hydrogen  thereby  Cofvlrom  Uad.  EUnMlaad  ia  deposited  frcMD 
produce*  a  flame  of  about  S  mm-  m  sire.  As  solutions  oontalolng  Dttria  add  at  pooxide  on 
•oon  as  all  the  air  lias  been  driven  out,  which  the  anode,  whilst  copper  ia  deposited  as  metal  at 
lUy  occupies  about  10  minutes,  the  iaauing   the  cathode,  it^might  be  supposed  that  t^"~ 


hydrogen  ia  ignited  and  the  Bunsen  burner 
I^hted.  U  after  about  16  minutes  no  brown 
rmg  makes  its  appearaaoe,  the  reagenU  may  be 
oonsidered  free  bom  arsenic  At  the  end  of 
30  minutes  the  capillary  tube  ia  sealed  off, 
and  the  open  end  also  fused  t<wether.  The 
mirror  is  then  compared  with  t£e  standard 
mirrors  aa  above  described. 

Prepanaion  oj  ttandard  mirrorf.  Pure  re- 
sublimed  ataenjous  oxide  i*  ground  in  an  agate 
mortar  and  dried  at  100*.  Then  O-I  gram  ia 
carefully  weighed  Mid  washed  into  a  1-litre 
Sask,  the  flask  being  filled  to  the  mark  vrith  dis- 
tilled watea.  Baoh  1  0.0.  of  this  solution  con- 
tains O-OOOI  arsenions  oxide ;  100  cc.  of  this 
•olntion  are  diluted  to  1  litre.  This  aeoond 
ulution  oontaina  0*00001  gram  of  anenions  acid 
in  each  1  CO.,  or  0-01  mg.  Standard  tubes 
OMitaininB  0O04,  0-000,  0-008,  O-OIO,  Ac,  mg. 
oan  then  be  prepared. 

When    foodatu^    are    being  examined  for 


would  be  no  difficulty  in  depositing  both  metal* 
concuirentiy.  It  must,  however,  be  temembwed 
that  unless  there  ia  a  conaidenble  concentration 
of  nitric  acid,  a  portion  of  the  lead  will  be  de- 
posited as  metal  at  the  anode.  On  the  other 
hand,  in  preaenoe  of  copper,  the  tendency  tn 
reduction  of  the  lead  and- its  appearance  at  the 
oathode  is  deoreaeed ;  that  ia  to  say,  in  preeoioe 
of  copper  alower  concentration  of  nitric  acid 
ia  required.  It  haa,  therefore,  been  found 
posaible  to  aeparate  the  two  metals.  The 
volume  of  solution  employed  was  60  ce.,  and 
oontained  I  cc.  HNO,  (1  ;4).  With  a  roUtioR 
anode  and  a  current  of  2  amperes,  the  whole  <u 
the  lead  was  deposited  in  S  minutes.  Th* 
outrent  was  then  increased  to  10  amperes,  whan 
the  last  traces  of  copper  were  removed.  Tlie 
washing  and  drying  of  the  anode  deposit  require* 
care,  smoe  the  peroxide  when  deposited  front 
weak  acid  aolationa  does  not  adhere  so  wcU  as 
from  Btronger  siduhona  (Sand), 


ANALYSIS, 


S25 


Cofper  and  arsenic  McGfty  finds  the 
following  condiiiona  give  a  Batisfactory  deposit 

01  copper  in  presence  of  axaeiuo.  Tl»e  arsenic 
remaining  in  the  sotntion  cannot*  lioweTcr»  be 
csstimatea  eleotnlytioslly,  mdess  present  in  very 
smaJl  quantities. 

To  the  sohition  20  o.c  anuiKmiam  hydrozids 
(m.  gr.  0-91)  snd  2-5  gram  ammonium  nitrste  are 
atkledv  the  vcdnme  of  solution  being  125  cc. 
The  solution  is  then  electrolysed  at  a  temperature 
of  50*-60*,  with  0-6  ampere  per  100  sq.  deem, 
of  electrode  surface.  As  much  as  0-22  gnj^m 
of  copper  wiU  be  deposited  in  3  hours.  With 
a  rotating  anode  about  15  minutes  are 
required.  In  thn  solution  the  arsenic  should 
be  present  as  arsenate.  CSopper  and  arsenic 
may  also  be  sei»rated  electrolytioaUy  from 
s(dutions  containing  potassium  oyanide.  If 
acid,  the  scdution  is  neutralised,  and  then 
sufficient  potasmnm  oyanidA  added  to  just 
redissolye  tiie  precipitate  first  produced.  With 
a  current  0-25-0*27  ampere,  the  whole  of  the 
copper  is  deposited  in  about  three  hours. 

AnUmomjf  from  Hn,  Tin  can  be  quantita- 
tively deposited  from  solutions  containing 
excess  of  ammonium  sulphide.  It  cannot, 
however,  be  deposited  from  solutions  contain* 
ing  excess  of  sodium  sulphide.  Antimony,  on 
the  other  hand,  can  be  draosited  from  sdlutions 
containing  excess  of  so<uum  sulphide.  It  is 
therefore  possible  to  separate  antimony  from 
tin  by  adding  excess  of  sodium  sulphide  to  a 
solution  containing;  the  two  metals.  If  the 
solution  is  acid,  it  is  first  made  slightly  alkaline 
with  sodium  hydroxide  before  the  sodium 
sulphide  is  added.  It  is,  however,  better  to 
first  precipitate  the  two  metals  as  sulphides,  and 
then  dissolve  them  in  a  concentrated  solution  of 
sodium  sulphide.  The  tin  should  be  in  the 
stannic  state.  The  solution  is  electrolysed  at  a 
temperature  of  50*>60*  with  a  current  of  from 
0-2  to  0-9  ampere  per  sq.  dcm.  of  electrode 
surface.  In  from  2  to  4  hours  the  whole  of  the 
antimony  is  deposited.  It  is,  however,  almost 
alwajTS  contaminated  with  small  quantities  of  tin. 

In  order  to  deposit  the  tin,  the  sodium 
sulphide  must  be  decomposed.  This  is  done  by 
adding  about  25  grams  ol  ammonium  sulphate^ 
and  boiling  until  no  more  hydrogen  sulphide  is 
evolved.  The  tin  is  now  deposited  by  electro- 
lysing with  a  current  density  of  from  0*3  to  0-5 
amperes. 

The  best  method  of  separating  antimony 
and  tin  is  that  of  Sand,  by  means  of  graded 
potential  and  a  rapidly  rotating  anode  (Ghem. 
Soo.  Trans,  xciii.  (2)  1908,  1572).  From  solu- 
tions  containing  strong  sulphuric  acid  (1:1) 
antimony  is  deposited  at  an  auxiliary  potential 
of  0*65  volt  when  the  temperature  is  kept  above 
100*,  and  a  small  quantity  of  hydrazine  sulphate 
is  added.  Tin,  on  the  other  hand,  under 
similar  conditions,  is  not  deposited  below  0*8 
volt.  The  method  of  procedure  when  dealing 
with  alloys  of  antimony  and  tin  is  as  follows : — 

The  alloy  is  dissolved  in  a  mixture  of 
40  ac.  cone,  sulphuric  acid,  5  cc.  water,  and 

2  CO.  nitric  acid  (1 :  42) ;  on  heating  to  180*-200'' 
solution  rapidly  takes  place.  It  is  necessary 
to  remove  the  nitric  acid  because  it  causes  the 
formation  of  antimonic  acid,  which  is  only 
slowly  reduced  to  the  metallic  state  electro- 
lytically.    In  order  to  decompose  the   nitric 


acid  (nitiosalph<Miic  asid).  a  current  of  5  amperes 
is  passed,  and  the  liquid  heated  to  250*-270*. 
After  the  current  has  been  passed  for  5  to  10 
minutes  at  the  high  temperature,  it  is  stopped. 
The  solution  is  OMled  to  100*,  and  0-5  gram  of 
hvdrasine  sulphate  added.  (N.B. — ^The  amount 
of  hydrasine  sulphate  added  should  be  equal  to 
the  weight  of  metal  taken.) 

The  temperature  is  then  raised  to  300*.  It 
is  again  ooded  to  100*,  when  from  30  to  40  cc 
of  water  and  another  0*5  gram  of  hydrasine 
sulphate  are  added. 

The  anode  ^  is  then  rotated  to  ensure  mixing 
of  the  solution,  the  temperature  of  which  rises 
to  about  120*.  The  amdysis  is  now  begun,  the 
auxiliary  potential  having  first  been  adjusted 
to  0-53-0-55  volt.  The  current  will  vary 
between  3-^  amperes,  and,  at  the  end  of  the 
electrolyns,  will  drop  to  0-4-0-5  volt.  Time  of 
electrolysis  from  20  to  30  minutes. 

The  tin  is  determined  as  follows:  The 
solution  after  the  antimony  has  been  deposited 
is  mixed  with  about  4  grams  of  oxalic  acid,  and 
is  neutralised  with  strong  ammonia.  In  order 
to  prevent  loss  by  spurtmg  the  electrodes  are 
placed  in  position,  the  rotating  stem  being 
passed  through  a  hole  drilled  in  a  clock  glass. 
The  ammonia  is  poured  on  the  dock  glass  and 
runs  down  the  stem  of  the  cJectrode  into  the 
solution,  the  anode  or  inner  electrode  being  at 
the  same  time  rotated.  Considerable  ebullition 
ensues,  but  none  of  the  liquid  is  spurted  out. 
Exact  neutralisation  is  asceAained  by  the  use  of 
methyl  orange  as  indicator.  Litmus  cannot  be 
employed,  since  its  colloidal  nature  hinders  the 
deposition  of  the  tin.  After  neutralisation, 
0*5-0-75  CO.  of  sulphuric  acid  are  added  for 
every  gram  of  oxalic  acid  previoudy  added. 

The  solution  is  electrolysed  at  a  temperature 
of  70*  with  a  current  of  3-4  amperes.    Time  of 
j  deposit,  60-^  minutes. 

Silver  and  copper.  (Smith  and  Frankel, 
Amer.  Chem.  J.  12,  104.)  To  a  neutral  solution 
of  the  silver  and  copper  salt,  add  2-3  grams  of 
pure  potassium  cyanide.  Electrolyse  at  a  tem- 
perature of  65*  with  a  current  of  0-03-0-06 
ampere,  and  maintain  the  potential  at  1-1-1*6 
volt.  The  silver  will  be  completely  deposited 
in  from  4  to  5  hours.  After  the  silver  has  been 
weighed,  the  electrode  is  replaced,  the  current 
and  voltage  increased,  when  the  copper  will  be 
deposited. 

Silver  may  also  be  separated  from  copper  in 
ammoniaoal  solutions  by  using  an  auxiliary  elec- 
trode, and  keeping  the  potential  below  0-5  volt. 

Iron  from  oiher  metals.  Iron  can  readily  be 
separated  from  aluminium,  vanadium,  gluoinum, 
uranium,  thorium,  and  many  other  metals  with 
which  it  may  be  alloyed  by  dissolving  in  sul- 
phuric acid,  filtering  from  any  residue,  nearly 
neutralising  with  ammonia,  and  electrolysing 
with  a  mercury  cathode. 

Cadmium  from  tine.    These  metals  can   be 

separated  by  means  of  graded  potential.    The 

solution  is  made  up  by  adding  first  2  cc.  o{ 

cone  sulphuric  acid,  then  3-33  grams  of  sodium 

hydroxide,  and  1  cc  of  glacial  acetic  acid.    The 

auxiliary  electrode  is  kept  at  a  potential  of  1-15 

-1*20  volts,  and  the  solution  electrolysed  at  a 

temperature  of  30*.    The  whole  of  the  cadmium 
*  After  the  metal  has  dlsMolved,  the  subsequent 
operations  are  carried  out  with    the   electrodes    io 
position. 


320 


ANALT8I& 


will  be  dspoaited  in  11-U  minutes.  The 
potential  is  afterwards  raised,  when  the  zinc  can 
be  deposited  in  about  90  minutes. 

Bibliography, — Meotroanalysis,  by  Edgar 
Snuth  (P.  Blakiston's  Son  &  Ck>.,  Philadelphia) ; 
Practical  Methods  of  Electrochemistry,  by  F. 
MoUwo  Perkin  (Longmans,  Qreen,  &  Go.,Lonaon); 
Elektroanalytisohe  Schnellmethoden,  by  A. 
Fischer  (Feniinand  Enke,  Stuttgart) ;  Quantita- 
tive Analyse  durch  Elektrolyse,  by  A.  Classen 
(Julius  Springer,  Berlin);  Analyse  des  M^tauz 
par  MUeotrolyse,  by  A.  Holland  et  L.  Bertiaus 
(H.  Dunod  et  E.  Pinat,  Paris) ;  Developments 
of  Electroanalysis,  Fresenius,  Zeitsch.  Anoig. 
Ghem.  1913,  81,  4.  F.  M.  P. 

ANAMIRTA  COGGULUS  or  A.  PANICULATA 
(CJolebr.).  The  former  is  the  superseded  name, 
and  the  latter  the  true  name,  of  the  Indian 
Memspermaoeous  liane,  whose  dried  fruits 
(Grains  of  Paradise)  are  supplied  under  the  name 
of  Coccuhu  indicus  {v.  Gocoulus  indicits). 

ANAHIRTIlf  V.  PicROTGziir. 

ANANAS,  OIL  or  ESSENCE  OF.  A  solution 
of  ethyl  butyrate  in  8  to  10  times  its  weight  of 
alcohol.  It  possesses  the  odour  of  the  pine- 
apple {Ananas  saiimis  (Schult.)),  and  ia  employed 
in  confectionery  and  prafumery ;  also  to  imitate 
the  flavour  of  rum JHofmann,  Annalen,  81,  87). 

ANANDONIS  GREEN.  Bydrated  chromium 
sesquioxide  {v.  Chbomium). 

ANASPAUN.  Trade  name  for  a  form  of 
wool-fat. 

ANATASE  or  Odahedrite*  One  of  the  tri- 
morphous  forms  of  titanium  dioxide  (TiOg)  met 
with  as  crvstalliBed  minerals ;  the  others  beinff 
rutile  and  brookite.  It  is  found  as  small, 
isolated  cr3rstaU  of  a  steel-blue  or  honey- 
yellow  colour,  in  sclustose  rocks,  particularly  in 
the  Alps ;  and  as  microscopic  crystals  is  of  common 
occurrence  in  sedimenta^  rocka        L.  J.  S. 

ANOHIETA  BABK.  The  root  bark  of  An- 
ehidea  aaltUaris  (A.  St.  Hil.),  one  of  the  Violaceae, 
a  bushy  shrub  ^tomng  at  Bio  de  Janeiro.  It 
contains  anMeitne,  a  substance  crystallising  in 
straw-coloured  needles,  having  a  nauseous  taste. 
Used  for  syphilis  and  quinsy  (Peokolt,  Arch. 
Pharm.  [2]  97,  271). 

ANCHUSDf  {Alkannin)  v.  ALEAKiniT. 

ANCYUTE.  A  hydrated  basic  carbonate  of 
cerium,  lanthanum,  and  didymium,  and  stron- 
tium 4Ge(OH)CO,*3SrCO,-3H,0,  found  as  small, 
yellow,  orthorhombic  pyramids  with  curved  faces 
m  svenite-pegmatite  at  Narsarsuk  in  the  Juliane- 
haab  distnct,  south  Greenland ;  sp.gr.  3*95. 

An  allied  mineral,  with  the  formula 

4(Ce,La,Di),(CO,),'5SrCO,(Ce,La,Di),Og, 

has  been  found  as  orthorhombic  grains  form- 
ing, with  oelestite,  monazite,  felapar,  &c., 
a  constituent  of  crystalline  limestone  at  Amba- 
toarinina  in  Madagascar.  This  has  been  named 
ambatoarinite  (A.  Lacroiz,  1916).       L.  J.  S. 

ANDA-ASSU,  OIL  OF.  An  oil  obtained  from 
the  seeds  of  Joannena  Princep$  (Veil.),  belonging 
to  the  Euphorbiaoese,  growing  in  Brazil.  It  is 
clear,  slightly  yellowish,  odourleas,  with  a  taste 
at  first  nauseating  and  then  sweet.  It  solidifies 
-t  8S  its  sp.gr.  at  18*"  is  0*9176  (Pharm.  J.  [3] 

380). 

ANDALUSITE.    One  of  the  three  modifica- 

s  of  crystallised  aluminium  silicate  Al^iOt, 
belonging  to  the  orthorhombic  system  ;  the 


other  modifioations  being  the  minerals  kyaaite 
and  fibrolite.  Andalusite  occurs  in  cryrtalline 
schists  and  metamorphio  rooks,  the  variety 
chiastolite  being  specially  abundant  in  the  baked 
clay-slates  surrounding  intrusive  igneOns  maasoo. 
It  IS  also  found  as  small  crvstals  and  grains  in 
some  granites,  due  probably  to  fragments  of 
the  surrounding  slates  having  been  incorporated 
in  the  isneous  magma.  Grains  of  anaalusite 
are  found  in  the  sands  and  sedimentary  rooks 
derived  bhm  these  primary  rocks.  The  pleo- 
chroism,  from  olive-green  to  rose-red,  is  a 
characteristic  feature  of  the  mineral  under  the 
microscope.  D  3*18,  H  7^.  Larae,  rough  opaque 
ciystaU  are  well  known  from  £isens-Alp  m  the 
Tyrol.  Clear  transparent  pebbles  of  a  rich 
brown  colour  are  found  in  the  Bio  Jequitinhonha 
in  Minas  Geraes,  Brazil ;  this  material  when  out 
as  a  gem-stone  displays  the  strong  pleochroiBm. 
The  variety  known  as  chiastolite  uiows  in  cross- 
sections  of  the  prismatic  crystals  a  dari^  crosB 
of  carbonaceous  material  enclosed  in  the  lighter 
coloured  andalusite ;  such  material  is  out  as  a 
ff  em-stone  or  charm.  Large  crystals  of  chiastolite 
nave  been  found  in  consider&bJe  numbers  at  Bim- 
bowrie,  near  Clary  in  South  Australia.    L.  J.  S. 

ANDAQUIES  WAX  v,  Waxss. 

ANDE8INE.  A  soda-lime  felspar  belonging 
to  the  group  of  plagioclaae-felBpars  (v.  Fslspab). 

L.  J.  S. 

ANDESUE.  A  group  of  volcanic  rocks  of 
intermediate  coznpotfition^  containing  on  an 
average  60  p.c.  of^silica,  and  corresponding  to 
the  piutonic  diorites.  They  are  usually  dark- 
coloured,  compact  rocks,  sometimes  with  a 
porphyritic  structure  or  a  vesicular  texture ;  and 
are  composed  essentially  of  plagioclase-felspar 
with  a  ferromsffnesian  mineral,  and  sometimes 
a  glassy  base.  According  to  the  ferromagnesium 
mmeral  present,  the  yarieties  homblende- 
andesite,  l)iotite-andesite,  and  pyroxene-ande- 
site  are  distinguished.  When  quarts  is  present 
the  rock  grades  into  the  dacites.  8p.gr.  2*6-2*8. 
They  are  of  wide  distribution.  Tne  Andes  of 
South  America  and  the  Cordilleras  of  Central  and 
North  America  are  built  up  largely  of  andesites ; 
and  here,  as  well  as  in  HunxaiT,  ore-deposita, 
particularly  those  of  gold  and  silver,  frequentlv 
occur  in  connection  with  them.  In  the  British 
Isles  they  are  abundant  in  the  Midland  Valley 
of  Scotland,  the  Cheviot  Hills,  the  Lake  District, 
and  in  North  Wales,  and  in  these  districts  ace 

Suarried   for  road-stones.    On   the  Contiiient 
tiey  are  also  used  for  building  stone  and  mill- 
stones.          L.  J.  S. 

ANDORITE.  Sulphantimonite  of  silver  and 
lead  AgPbSb,S«,  orvstallising  in  the  ortho- 
rhombic system.  Tne  mineral  was  indepen- 
dently described  in  1892  from  FelsObanya  in 
Hungary,  and  Oruro  in  Bolivia,  under  the  names 
andorite,  sundtite,  and  webnerite.  It  is  dark 
steel-grey  with  metallic  lustre,  and  a  shining 
black  streak ;  no  cleavage  ;  sp.^.  6*35  ;  fi  3^. 
Analyses  show  10-11*7  p.c.  of  silver  (according 
to  the  formula  As  =  12*42  p.c.),  there  being 
small  amounta  of  copper  also  present.  At 
Oruro,  in  the  San  Jos6  and  Itos  Atocha  mines, 
it  occurs  rather  plentifully  as  well-formed 
crystals  and  as  a  massive  silver  ore  (Prior  and 
Spencer,  Mineralog.  Mag.  1897,  xi,  286  ;  Spencer, 
tbid.  1907,  xiv,  316).  L  J.  & 

ANDROGRAPmS  PANICULATA  (Nees)  or 


ANILINE. 


327 


Karfoi,  An  IndUn  plant ;  is  used  as  a  tonio, 
and  Is  similar  to  quassia  in  its  action. 

ANDROPOGON  OIUS  v.  Oils,  Essbhtial. 

ANDR05IN  V,  Glugosidbs. 

ANESIN  {AfUMn).  An  aqueous  solution  of 
acetonechloroform,  havinff  marked  anspsthetic 
and  hypnotio  properties  (Apoth.  Zeit.  1897,  12, 
608)  (v.  Acbtokschlobofobm). 

AJNETHOL  V,  Oils,  Esssntux. 

ANGELICA  OIL  v.  Oils,  Essential. 

ANGELINE  GieH,,OaN  (snrinamine,  geoffro- 
yine,  andiiine,  rhatanine)  (Hiller-Bombien, 
Arofa.  Pharm.  1892,  230,  613;  Goldsohmidt, 
Monatsh.  1913,  33,  1379 ;  34,  659),  m.p.  above 
233''    (indefinite).    Identical   with    n-methyll- 

tyrosine  [a]^^+ 19*76*.    Synthesised  by  Fischer 

and  UpschitK  (Ber.  1916,  48,  360). 

ANGIOO  BESIN.  A  Brazilian  gum  obtained 
from  PipUidenia  rigida  (Benth.)  [Acacia  Angico] ; 
soluble  in  water  and  proof  spirit.  Used  in  chest 
complaints  (Symes,  Pharm.  J.  [3]  13,  213). 
Angico  wood  is  that  of  another  Brazilian  legu- 
minous plant,  Enterokbium  eUipiicufn  (Bentn). 

ANGIONEUROSnf.  Syn.  for  nitn^lycerin 
as  used  in  pharmacology. 

ANGLSITE.  Native  lead  sulphate  (PbS04), 
forming  brilliant,  colourless,  orthorhomoic  crys- 
tab,  isomorphous  with  baiytee  (BaS04)  and 
oekstite  (8^04).  It  occurs  in  the  upper 
oxidised  zones  of  veins  of  lead  ore,  haymg 
resulted  by  the  alteration  of  galena  (PbS).  It 
is  lees  common  than  cerussite  (PbCO,),  with 
which  it  has  sometimes  been  mined  as  an  ore  of 
lead.  Good  ciystals  have  been  f oimd  at  many 
looalitiee,  perhaps  most  abundantly  at  Broken 
HiU,  in  New  South  Wales.  The  mineral  takes 
its  name  from  the  Isle  of  Anglesey,  where 
crystals  were  found  h^  W.  Withering,  in  1783, 
in  the  Paiys  copper-mme.  L.  J.  S. 

ANGOSTURA     BARK     or     ANGUSTURA 

BARK  V.  OUSPABIA  BABK. 

ANHALAMINE,  ANHALDfE,  ANHALONI- 
DDfE,  ANHALONINE,  v.  Mbzcalinb. 

ANHALONIUM     (CACTUS)     ALKALOIDS. 

Seven  different  ba^^es  have  been  isolated  from 
various  species  of  cactus  and  have  been  investi- 
gated chiefly  by  Heffter.  They  are  derivatives 
of  /9-phenylethylamine.  Anhaline  is  fi-P' 
hydrozyphenyldimethylethylamine, 

H0C^4C!H,-CHj-N(CHs), 

identical  with  hordenine.  Mezcaline  is  /3-3'4'6- 
txihydrozyphenylethylamine.  Anhalamine,  an- 
hah/iidine  and  ptUoUne  are  methylated  3*4*6- 
trihydroxyphenylethylamines,  but  anhahnint 
and  U)p7uilhorine  each  contain  two  of  their  three 
oxygen  atoms  in  a  different  kind  of  linking 
(E.  Sp&th,  Monatsh.  Chem.  1919,  40,  129). 

ANHYDRITE.  A  mineral  consistuig  of 
calcium  sulphate  CaSOi,  so  named  to  distinguish 
it  from  the  more  common  hydrated  calcium 
sulphate,  gypsum.  From  a  pure  aqueous  solu- 
tion calcium  sulphate  crystallises  as  gypsum, 
but  when  the  solution  is  highly  chargea  with 
salts  (sodium,  potassium,  and  csJcium  chlorides, 
and '  magnesium  sulphate)  it  separates  as 
anhydrite.  Anhydrite  crystallises  in  the  ortho- 
rhombic  system,  but  in  its  crystallographic 
chajracters  it  shows  little  analogy  with  the 
orthorhombic  barium  and  strontium  sulphates, 
barytes,  and  celestite,  with  which  it  would  be 


expected  to  be  isomorphous.  An  important 
character  is  the  cleavage  in  three  directions 
parallel  to  the  axial  planes  of  symmetry ;  the 
mineral,  therefore,  breaks  up  into  culiies  like 
rock-salt.  Well-formed  crystals  are  not  com- 
mon ;  they  have  been  found  in  the  salt-deposits 
of  Germany  and  Austria,  and  in  dolomite-rock 
in  the  Simplon  tunnel,  in  Switzerland.  Usually, 
the  mineral  occurs  as  compact,  granular  masses 
of  a  white,  giey,  reddish,  or  bluish  colour,  and 
resemblinff  marble  in  appearance.  Sp.gr.  2*9- 
3*0;  hanmess  3-3|,  being  considerably  higher 
than  gypsum.  It  is  of  frequent  occurrence  as 
layers  interbedded  in  deposits  of  gypsum  and 
rock-salt.  The  *  anhydrite  region '  forming  the 
base  of  the  Prussian  salt-deposits  consists  of 
alternating  beds  of  anhydrite  and  rock-salt. 
Bands  of  anhydrite  also  occur  throughout  the 
salt-deposits,  and  are  known  to  the  miners  as 
'  year-rings.*  In  contact  witii  water  anhydrite 
becomes  altered  into  gypsum  with  an  increase 
in  volume  of  60  p.c.  On  this  account  galleries 
in  the  salt-mines  when  driven  through  oeds  of 
anhydrite  gradually  become  closed  up.  Exten- 
sive beds  of  the  mineral  occur  in  the  gypsum 
deposits  of  Nova  Scotia.  In  the  red  rocKS  of 
Permian  and  Triassio  age  of  the  North  of 
England  anhydrite  is  not  uncommon.  For 
example,  it  forms  a  bed  7  feet  in  thickness  in 
the  Cocklakes  gypsum  mine  at  Cumwhinton 
in  Cumberland;  and  it  is  recorded  from  Dur- 
ham, Westmoreland,  Yorkshire,  Staffordshire, 
Leicestershire,  Nottinghamshire,  Derbyshire,  and 
Cheshire.  For  details  of  British  occurrences,  see 
Special  Reports  on  the  Mineral  Resources  of 
Great  Britain,  vol.  iii.  Gypsum  and  Anhydrite, 
Mem.  Geol.  Survey,  London,  1916 ;  2ndedit.,  1918. 

Anhydrite  has  as  yet  been  put  to  few  practical 
uses.  It  has  been  employea  in  agriculture  as 
a  'land  plaster.*  By  exposure  to  the  weather 
it  becomes  converted  into  gypsum,  and  can 
then  be  used  for  the  manufacture  of  plasters^ 
A  bluish-violet,  compact  variety  known  as 
'  vulpinite,*  from  Vuipino  in  Lombardy,  has 
been  used  as  an  ornamental  stone.  The  sug- 
gestion to  use  gypsum  as  a  source  of  sulphur 
would  apply  also  to  anhydrite.  L.  J.  S. 

ANIL.  The  name  of  the  American  species 
of  the  indigo  plant,  Indigofera  anil  (Linn.). 

ANILmE. 

ifMtory.— >First  observed  by  Unverdorben  in 
1826  among  the  products  of  the  destructive 
distillation  of  indieo.  Detected  by  Runfe  in  coal 
tar  in  1834,  and  l>y  Fritzsche  in  1840,  among 
the  products  obtained  by  distilling  indigo  with 
alkau  hydroxides.  Prepared  by  Zinin  in  1840, 
by  the  reduction  of  Mitscherlich*s  nitrobenzene 
with  hydrogen  sulphide.  Unverdorben  called  his 
product  kryataUin ;  Runge,  kyanol ;  Fritzsche, 
anUin ;  Zinin,  henzidam. 

In  1843  Hofmann  showed  that  nitrobenzene 
could  be  reduced  by  a  metal  such  as  zinc  in  the 
presence  of  a  dilute  acid,  and  also  that  krystallin, 
kyanol,  anilin,  and  benzidam  were  identical  with 
each  other.  Shortly  afterwards  Bechamp  stated 
that  nitrobenzene  could  be  reduced  by  ferrous 
acetate  in  the  presence  of  water,  but  that  the 
oxalate,  sulphate,  &c.,  had  no  effect. 

In  the  year  1866  Perkin's  discovery  of  mauve 
gave  rise  to  a  commercial  demand  for  aniline, 
and  the  manufacture  was  commenced  by  Messrs. 
i  Simpson  &  Maule. 


the  tTDatment  of  Ux  MAToely  ezut«d,  ww  intro- 
duced into  glass  b&llooiu  (known  as  '  bolt 
heads ')  of  1  gallon  oapaeity,  and  the  calculatod 
qnantity  of  nitrio  aoid,  mized  wittk  about  an 
eaual  volnme  of  milphoho  aoid,  was  fcraduallv 
added,  the  mixture  awung  round  and  veil 
Bgitat«d,  and  then  allowed  to  stand.  It  was 
naual  to  have  about  twenty  balloons  in  a  row, 
and  to  add  acid  in  tnm  until  the  reaotion  was 
eomidete. 

The  nitrobeniene  was  separated,  washed,  and 
redneed  with  iron  boringi  and  acetio  acid,  at 


first  in  a  copper  still,  later  in  an  iron  cylinder. 
The  aniline  was  freed  fran  water,  reoUfied,  and 
was  then  leadj  for  use.  '  The  seUing  pnoe  was 
about  a  guinea  a  pound- 
Somewhat  latv  oaat-iron  cjlindera  of  con- 
siderable siie  were  used  for  the  reduction,  acetic 
aoid  being  still  osed  and  neutralised  with  soda  or 
lime  at  t£a  end  of  the  reaction,  and  Uie  aniline 
was  in  some  factories  distilled  off  over  a  naked 
fire,  in  others  steam  was  l>lown  into  the  mixtim, 
and  the  aniline  and  water  condensed  and 
separated.  Acetic  acid  continued  to  be  used 
until  abont  1806.     Since  thai  time  the  apparatus 


,JL^^|^   EE- 


Fia.  1.— Axunti  Oa.  Punt. 

T,  Fwd  boppec  tor  borloss.        [.,  OaCter- 


plpe- 

bas  midergons  little  change,  the  treatment  con- 
sisUng  in  reduction  mainly  bv  the  use  of  iron 
and  water,  hydroohlorie  acid  being  employed  tc 
■tart  the  reaction. 

The  aniline  machine  shown  in  Fig-  1  is  the 
type  tbat  ovea  the  beat  results.'  A  careful 
comparison  between  this  deaign  and  the  hori. 
tontid  machine  has  proved  namistakably  that 
the  vertical  machine  is  more  economical  and 
better  in  every  respect.    Hiis  is   particularly 

-  the  case  with  regard  to  repairs  and  maintenance. 
The  machine  is  of  cast-iron,  1|  inches  thick,  with 

-  driving  grar,  agitating  shaft,  and   blades,   as 


R,  Reolver 
S,  Stsam  pomp. 
T.  SettUns  InbM. 
U,  Air  pismire  an. 


shown  in  the  sketch.  An  important  fealnre  is 
Uie  renewable  cast-iron  lining  platea  at  the 
■ides  and  bottom,  which  protect  tiia  machine 
from  the  frictioa  caused  by  the  revolving  "im 
of  iron  borings.  It  is  6  feet  0  inches  deep,  and 
t  feet  6  inch^  fa)  diameter,  having  a  total  capa- 
city of  OSO  gallons.  Steam  is  admitted  through 
the  vertical  th^t,  which  is  hollow,  and  passes 
throuf^h  the  extremities  of  the  horizontal 
agitating  blades.  Twenty-oni?  of  these  machines 
are  required  to  produce  ISO  tons  of  aniline  oil 
per  month.*  Acbai^of  10001lw.of  nitrobeniene 
■■  —'1  into  the  receiving  pan  above  the  machine. 


ANILINE. 


329 


To  start  the  reaction,  1  cwt.  of  clean  oast-iron  | 
borings,  10  n^ons  of  hydrochloric  acid,  and 
6  gallons  of  water  are  ran  in  through  the  funnel^ 
shaped  hopper,  and  simultaneously  steam  is 
turned  on  and  the  nitrobensene  run  in  a  thin 
stream  into  the  dish  on  the  top  of  the  machine. 
The  wooden  plug  in  the  hopper  is  driven  in  tight, 
and  the  space  between  it  and  the  hopper  is  kept 
full  of  iron  borings.  By  dezterouFly  manipulat- 
ing the  wood  plug,  the  borings  can  be  added 
without  allowing  any  vapour  to  escape.  This 
simple  method  of  *  feedmg '  the  iron  borings 
has  ployed  better  than  many  of  the  mechanical 
feedmg  devices  that  have  been  tried.  Distilla- 
tion proceeds,  and  the  distillate  passes  through 


the  condenser  and  runs  back  into  tbe  dish* 
together  with  the  nitrobensene  which  is  carried 
over.  The  iron  borings  and  nitrobeniene  are 
added  only  in  sufficient  quantitiee  to  maintain 
a  constant  level  in  the  dish.  If  the  reaction 
proceeds  too  violently,  loss  is  caused  by  the 
formation  of  benzene.  When  the  level  of  the 
liquid  in  the  dish  begins  to  lower,  the  supply  of 
nitrobenxene  and  iron  borings  ia  increased.  This 
process  is  continued  until  the  whole  charge  of 
nitrobenzene  is  run  in,  which  takes  about  10 
hours.  Tbe  total  weight  of  iron  borings  re- 
quired is  9  cwt.  A  sample  caught  as  it  runs 
from  the  condenser  should  then  be  quite  free 
from  nitrobenzene,  and  the  machine  will  contain 


FiQ.  2. — Vaouum  Still  fob  AiiiLma  Oil. 


A,  Vaooam  still. 

B,  lotemal  hollow  atay. 

C,  Steam  tnbfli. 

D,  Do.      do. 

E,  Steam  inlet. 

F,  Do.    onttet. 

G,  Vapour  pipe  to  condenser. 
H,  Pressure  gauge. 


J,   Condenser. 

K,  Gold-water  Inlet. 

L,  Overflow  for  water. 

M,  Receiver  for  distilled  oil. 

K.       Do.  do.      do. 

O,  Connection  from  vacuum  pump. 

P,         Do.        do.  do. 

Q,  Inlet  from  condenser. 


R,  Inlet  from  oondenier. 

8,   Air-admission  tap. 

T,  Do.  do. 

U,  Bun-oS  tap  for  distilled  oO. 

V,      Do.  do.  do. 

Wi  Connection  from  vaoaum  pomp 


only  aniline  oil,  water,  and  oxide  of  iron.  The 
supnly  of  steam  is  then  increased,  so  as  to 
distu  over  the  aniline  oil  and  water,^  and  the 
distillate  is  diverted  into  the  tank  beneath 
the  condenser.  The  steam  used  for  this  dis- 
tillation is  not  pure  steam,  but  is  generated  from 
the  aniline  water  mentioned  below,  in  a  separate 
boiler.  The  aniline  water  is  that  which  separates 
from  the  oil  in  the  separating  tubes,  and  con- 
tains about  2  p.c.  of  aniline  oilin  solution.  The 
aniline  and  water  in  the  tank  below  the  con- 
denser are  pumped  into  the  settling  tubes,  and 

1  In  some  works  this  distillation  is  not  done;  bat 
the  eootents  of  the  redaction  apparatus  are  passed  im- 
mediately through  a  Alter  press,  the  filtrate  then  nmninjr 
directly  or  being  pumped  into  the  settling  tanks* 


allowed  to  settle  for  48  hoursx.  The  distillation 
of  the  oil  and  water  from  the  machine  takes 
about  7  hours,  and  during  the  last  hour  pure 
steam  is  again  used,  so  that  when  the  operation 
is  finishea,  the  condensed  water  left  in  the 
machine  will  be  free  from  aniline,  and  can  be 
used  for  flushing  out  the  oxide  of  iron  into  the 
gutter  wliich  runs  to  the  settling  tanks  outside. 
The  oxide,  after  the  water  is  drained  off,  is 
dried  and  ground,  and  disposed  of  for  the 
purification  of  coal  gas  from  sulphur.  Large 
quantities  are  also  now  bein^  used  m  the  manu- 
facture of  cheap  black  pamts,  and  the  con- 
sumption in  this  direction  is  increasing.  The 
anilme  oil  which  has  settled  to  the  bottom  of 
the  settling  tubes  is  run  off  into  the  air-prossuro 


880 


ANILINE. 


egg  bttlowv  and  blown  into  the  crude  aniline  oil 
store  tanks,  readv  for  the  final  purification  by 
distiUation  in  the  vaoaom  still.  The  upper 
layer  of  water  left  in  the  settling  tubes,  and 
which  contains  about  2  p.o.  of  aniline  in  solution, 
is,  as  already  explained,  used  for  feedinff  the 
aniline  steam  boiler.  The  average  yieul  of 
crude  aniline  oil  from  each  machine,  with  a 
charge  of  1000  lbs.  of  nitrobenzene,  is  766  lbs. 
The  yield  of  pure  aniline  oil  from  nitrobenzene 
is  given  further  on. 

The  final  purificj^tion  of  the  crude  aniline  oil 
is  done  in  a  vacuum  still.  The  sketch  (Fig.  2) 
shows  one  of  these  stills  of  recent  desisn.  The 
body  of  the  still  is  wrought-iron,  15  teet  long, 
and  7  feet  6  inches  in  diameter,  having  a  total 
capacity  of  4000  ^rallons,  and  capable  of  dis- 
tilling 35,000  lbs.  m  one  charge.  The  steam  is 
supplied  from  a  boiler  having  a  working  pressure 
of  100  lbs.  per  sq.  inch,  at  which  pressure 
the  steam  possesses  a  temperature  of  170*. 
The  internal  steam  tubes  are  wrought-iron, 
2  inches  in  diameter.  In  plaoe  of  the  usual 
straight  tubes  which  used  to  be  expanded  into 
both  end  plates,  bent  tubes  are  'employed, 
which  enter  and  return  to  the  same  end  of  the 
stilL  This  prevents  the  *  tearing  *  of  the  tubes 
owing  to  expansion  and  contraction,  and  the 
'  breathing '  of  the  end  plates.  The  '  column ' 
is  of  cast  iron,  18  feet  high  and  9  inches  in 
diameter.  Tlie  condensing  coils  consist  of  three 
vertical  flat  copper  coils,  2  inches  in  diameter, 
arranged  side  by  side  in  a  wrought-iron  tank, 
the  distillate  entering  all  the  three  coils  simultane- 
ously from  tlie  still  head  by  means  of  branch 
pipes.  The  total  length  of  copper  pipe  in  the 
condenser  is  432  feet.  The  two  receivers  permit 
continuous  working,  so  that  when  the  nrst  is 
full,  as  indicated  by  the  gauge-glass  tube,  it  is 
shut  off,  and  the  second  brought  into  use.  The 
contents  of  the  first  can  then  oe  drawn  ofiE  while 
the  second  is  being  filled,  and  the  vacuum  is 
thus  maintained  throughout. 

The  still  is  charged  with  35,000  lbs.  of  crude 
aniline  oil  from  the  store  tank,  and  steam  is 
turned  on.  The  first  fraction,  about  7  p.c  of 
the  distillate,  consists  of  aniline  oil  and  water, 
which  is  added  to  the  crude  oil  and  water  in  the 
separating  tubes.  The  next  fraction  is  'light 
aniline,'  and  consists  of  aniline  oil  with  a  small 
qiiantity  of  benzene.  If  the  reduction  of  the 
nitrobenzene  has  been  carefully  performed,  this 
fraction  is  only  about  4  p.c.  of  the  distillate. 
It  ^  is  collected  and  redistilled,  giving  pure 
aniline  and  benzene,  the  latter  being  returned  to 
the  nitrobenzene  department,  to  be  renitrified. 
The  next  fraction  is  pure  aniline  oil  of  market- 
able quality,  clear  and  water-white.  The  tail 
end,  called  'last  runnings,'  forms  about  5  p.c. 
of  the  distillate,  and,  on  redistillation,  yields 
80  p.c.  of  pure  marketable  aniline  oil.  The 
totsl  yield  of  pure  aniline  oU  obtained  from 
nitrobenzene  is  71}  p.c.  As  the  pure  benzene 
yields  1541  p.c.  of  nitrobenzene,  and  the  latter 
71}  p.c.  of  pure  aniline  oil,  the  total  yield  of 

gure  aniline  oil  from  pure  benzene  is  110*85  p.c. 
ompared  with  theory,  there  is  little  room  for 
improvement. 

The  process  of  reduction  and  rectification  as 
described  applies  also  to  toluidine,  and  modifica- 
tions of  the  process  are  also  in  use  for  the  pro- 
duction of  xylidine  and  alphanaphthylamine, 


and  of  the  rednotion  portion  for  the  manufacture 
of  metaphenylene-  and  metatolylene-diamine 
horn  the  respective  dinitro-  compounds. 

Catalytic  Reduction  oj  NUrdbemene.—ThM  is 
effected  oy  passing  a  mixture  of  nitrobenzene 
vapour  and  nydrogen  (or  other  reducing  gases) 
over  a  catalyst  heated  to  a  suitable  temperature 
(usually  200''-300'').  The  catalysts  which  have 
been  proposed  are  copper  (Eng.  Pats.  13149, 
15334,  1914;  5692,  6409,  1915;  U.S.  Pat. 
1207802 ;  D.  B.  PP.  139457,  282568 ;  Fr.  Pat. 
312615),  nickel  (Eng.  Pats.  16936,  22523,  1913  ; 
D.  R.  P.  282492;  Fr.  Pats.  458033,  and  1st 
addition),  iron  oxides  (Fr.  Pat.  462006),  iron 
(D.  B.  P.  281100),  and  sUver  or  gold  (D.  B.  P. 
263396). 

Many  patents  have  been  taken  out  for  the 
electrolytic  reduction  of  nitrobenzene,  but  it  is 
doubtful  whether  this  process  is  used  on  the 
lai]Ke  scale. 

The  reduction  of  nitrobenzene  may  also  be 
carried  out  by  boiling  it  with  sodium  ousuiphide 
solution  (D.  K.  P.  144809),  and  an  80  p.c.  yield 
of  aniline  is  said  to  be  obtained  by  heating 
chlorobenzene  with  ammonia  and  s  little  copper 
sulphate  (£i^.  Pat.  3966,  1908;  D.  B.  P. 
204951 ;  Fr.  Pat.  397485). 

Valuation  of  Commercial  Aniline  OU. 

Aniline  oil,  as  it  occurs  in  commerce,  may 
contain  as  impurities  water,  traces  of  insoluble 
hydrocarbons  and  of  orthotoluidine,  sometimes 
traces  of  hydrogen  sulphide,  and,  if  careiesaly 
made,  of  nitrobenzene,  benzene,  and  ammonia. 
Besides  these,  which  should  be  carefullv  tested 
for,  there  is  possibly  a  certain  amount  of  amino- 
thiophen,  wnich  has  no  deleterious  action  for 
most,  if  not  all,  of  the  purposes  for  which  aniline 
is  used,  and  which,  moreover,  for  the  present  at 
least,  cannot  readily  be  got  rid  oL 

TJie  method  of  testii^  usually  adopted  is  to 
determine  the  boiling-pomt  of  the  sample.  For 
this  purpose  100  c.c.  are  introduced  into  a  small 
boiling  nask  with  side  tube,  and  distilled  through 
a  short  condenser  into  a  graduated  100  ao. 
cylinder.  Beadings  of  the  thermometer  are 
taken  as  each  10  c.a  of  the  cylinder  fills,  and  the 
last  when  95  ac.  are  filled.  An  alternative 
method  ia  to  take  readings  of  the  cylinder  at  each 
fifth  of  a  degree  rise  of  the  thermometer.  It  is 
also  usual  to  note  the  temperature  when  the  fint 
drop  has  fallen  from  the  condenser.  The  ther- 
mometer readings  should  be  oorxeoted  for 
barometer  and  immersion  of  mercurial  column 
in  the  vapour  of  the  liquid,  and  of  course  for  the 
errors  peculiar  to  the  thermometer  in  oae. 

A  few  fragmente  of  jdatinum  wire,  fire-brick, 
or  wroiu;ht  iron,  should  be  placed  on  the  bottom 
of  the  flask,  and  great  care  used  to  adjust  the 
size  of  the  flame  and  rate  of  boiling.  The  flaak 
also  should  be  held  by  the  neck  in  a  good  dip 
over  the  naked  flame,  gauze  being  apt  to  cause 
currento  of  heated  gas  to  flow  up  round  the  neok 
of  the  flask  and  superheat  the  vapour. 

The  specific  gravity  of  the  sample  may  also 
be  taken  (pure  aniline  has  a  spednc  gravity  ol 
1'026&-10267  at  15''),  although  this  mdication 
is  not  of  great  moment  if  the  boiling-points 
are  good. 

The  following  is  an  examj^  of  the  determina- 
tion of  the  boinng-point  (Walter,  Chem.  Zcot. 
1910,  34,  702) ;— 


ANI8IDIK1. 


831 


Temperatare.  P.o.  over. 
182-4*  3 

182-6'*  4 

182-8*  6-5 

183-0*  11 


Tamper«tiii«.  F.c.  over. 
183*2''  20 

183-4''  97 

183-6''  98 

183-8"  99 


If»  in  carrTing  ont  the  boiling  test,  the 
temperature  nses  considerably  at  the  end,  the 
preeenoe  of  toluidine  may  be  suspeoted*  This 
can  be  detected  when  a  considerable  quantity 
of  commercial  pure  aniline  is  made  into  aoet- 
anilide.  Om  lecrystallising  this  and  working 
up  the  mother  liqdors,  a  small  quantity  of  im- 
pure acetyl  compound  of  low  melting-point  will 
always  be  found  in  the  most  soluble  portion,  or 
first  mother  liquors. 

Pure  aniline  melts  at  — 6'2'*,  and  boils  at 
80''-81720  mm.  and  184-4<'/760  mm. 

AniUne  may  be  tested  for  insoluble  oils 
by  dissolving  10  o.c.  in  40  ao.  of  hydrochloric 
acid  and  50  0.0.  of  water.  The  solution  should 
be  quite  dear. 

Nitrobenzene  shows  itself  with  the  insoluble 
hydrocarbons.  A  Y&ry  delicate  test  for  it  is  to 
shake  the  sample  of  aniline  violently  for  a  few 
minutes,  and  then  to  notice  the  colour  of  the 
froth.  The  merest  trace  of  nitrobenzene  colours 
it  a  very  distinct  yellow. 

The  presence  of  water  may  be  detected  by 
disfcilling  the  sample  (100  ac.)  as  for  a  boiling- 
point  (^termination,  and  collecting  the  fint 
10  cc.  in  a  narrow  graduated  cylinder  of  16  c.c. 
capacity,  shaking  with  1  co.  of  saturated 
sodium  chloride  solution,  and  reading  off  the 
volume  of  the  latter.  The  method  will  not 
show  the  presence  of  lees  than  0*3  p.c.  of  water, 
consequently,  0*3  cc.  must  always  be  added  to 
the  amount  of  salt  solution  observed. .  It  is  not 
usual  for  aniline,  sold  as  pure,  to  contain  more 
than  0-6  p.c.  of  water. 

TotnUbe  liquid  should  boU  at  197''-198S 
show  a  sp-gr.  of  about  1-000,  and  contain 
30-^  p.0.  para-,  the  rest  ortho-  toluidine. 

Ortnotoloidlne.  The  sp.gr.  of  commercial 
orthotoluidine  should  be  about  1-0037 ;  b.p. 
about  197*^-198'';  should  not  solidify  on 
cooling  to  —4".  The  pure  substance  boils  at 
199-7^  and  does  not  solidify  at  — 20^  Its 
density  at  16%  compared  with  water  at  16^*,  is 
1-0031. 

ParatolnidiliA.  When  pure,  this  melts  at 
45"  and  boils  at  200-4"/760  mm.  and  SO^-Sr'/lO 
mm.  Its  density  is  1-046.  Lun^e  (Chem. 
Ind.  1886,  8,  74)  has  published  a  table  showing 
the  specific  gravities  of  mixtures  of  o-  and 
p-tolmdine. 

For  the  estimation  of  small  amounts  of  p- 
toluidine  in  o-toluidine,  Schoen's  method  is 
perhaps  the  best.  A  standard  oil  is  prepared, 
contaming  8  p.c.  of  p-toluidine  and  92  p.o.  of 
o-toluidine,  1  cc.  of  which  is  diasolvea  with 
2  cc.  of  pure  hydrochloric  acid  in  50  cc.  of 
water,  ana  oxidised  cold  by  adding  1  cc  of  a 
saturated  solution  of  potassium  dichromate. 
After  standing  for  two  hours,  the  product  is 
filteored,  the  precipitate  being  washed  with  water, 
and  the  filtrate  and  washings  made  up  to  100  cc 
The  toluidine  to  be  tested  is  treated  m  the  same 
manner,  and  compared  colorimetrically  with 
the  above  solution.  J.  0.  C. 

ANIUNE  BLACK  v.  Dyuho. 

ANILINE     BLUB     v. 
ooLOUBnro  icAxnBa, 


ANILINE    BROWN    v.    Azo-    cx>XiOUBiNO 

MATTXBS. 

ANILINE  SALT.  The  oommerdal  name  of 
aniline  hydrochloride  GtHs-NH„HGL 

It  is  prepared  in  luge  quantities,  for  the  use 
of  oalico-pnnters,  who  employ  it  in  the  .produc- 
tion of  aniline  black.  The  process  eonslsts  in 
mixing  the  calculated  quantities  of  pure  aniline 
and  hydrochloric  acid  in  lead-linea  or  nickel- 
lined  tanks,  and  allowing  the  salt  to  crystallise, 
freeing  it  from  mother  liquors  in  a  centrifugal 
machine,  and  dzying  at  a  low  temperature.  ^Hie 
hydrochloric  add  used  should  be  of  good  quality, 
free  from  iron  and  even  from  traces  of  copper, 
or  the  salt  will  rapidly  blacken. 

The  mother  liquors  may  be  neutralised  with 
lime  or  soda,  and  the  aniline  recovered,  or  they 
may  be  boiled  down  and  used  in  ma.lnng  magenta 
by  the  nitrobenzene  process,  &c 

*  Aniline  salt*  occurs  in  commerce  in  lazge 
white,  nacreous  and  much-contorted  plates. 

The  great  desiderata  for  the  cauco-printer 
are  that  the  salt  should  be  made  from  pure 
aniline  and  should  be  dry  and  normal,  contain- 
ing 93  parts  of  aniline  to  36*5  parts  of  hvdro- 
cmoric  acid ;  it  should  be  free  from  sand  and 
giit,  which  injure  the  printing  machines. 

J.  C  C 

ANILINE    YELLOW    v.    Azo-    ooLomtnro 

MATTSBS. 

ANIMAL  OILS  and  FATS  v.  Oils  ajtd  fats. 

ANIHE  and  ANIMI  v,  Oubo-bbsins. 

ANISEED,  (ilnitf,  Fr.,  Ger.)  The  fruit  of  the 
Pimpinetta  Anisum  (Linn.),  cultivated  in  Malta, 
Spain,  and  Germany.  Used  for  the  preparation 
of  anise  oil  and  cordisls.  Alcohol  extracts  36*24 
p.c.  of  this  spice  (Biechele,  Pharm.  J.  [3]  10, 
878). 

ANISE  CAMPHOR  «.  Camphobs. 

ANISE  OIL.  The  essential  oQ  of  aniseed, 
obtained  by  distilling  it  with  water.  According 
to  Landolph  (Gompt.  rend.  81,  97 ;  82,  220),  it 
contains  90  p.c  of  aneihole,  boiling  at  22-6°. 
Anethole,  according  to  Perkin  (Chem.  Soc. 
Trans.  32,  668),  is  p-aU^lanisole  GcH4(0Me)CH : 
CH-CHa :  he  obtained  it  by  heating  p-methoxy- 
phenylorotonic  acid. 

Ajiise  oil  is  sometimes  adulterated  with 
fennel  oil ;  this  can  be  detected  by  heatins  the 
oil,  when  the  fennel  odour  becomes  perceptible. 

Star  anise  oil  has  a  similar  colour  and 
taste,  but  it  does  not  solidify  at  2^  {v.  Oils, 
Essential). 

ANISmnfE.  NH,-C«H«OMc  Orthanisi- 
dine.  Obtained  by  the  reduction  of  orthonitrani- 
sole  with  tin  and  hydrochloric  acid  or  iron  and 
hydrochloric  acid  (Meister,  Lucius,  and  Brtining, 
D.  B.  P.  7217  of  Dec.  3,  1878),  is  a  colourless 
oil,  which  freezes  at  2-6'',  boils  at  226-6''  at  734 
mm.  pressure  (Miilhauser,  Annalen,  207,  239) ; 
at  225''  at  760  mm.  (Perkin,  Chem.  Soc.  Trans. 
69,  1210),  and  has  a  8p.gr.  1108  at  26^  Can 
also  be  prepared  b^r  heating  a  mixture  of  0- 
aminophenol,  potassium  methyl  sulphate,  and 
potassium  hy<£roxide  solution  under  pressure. 
When  diazotised  and  treated  with  /3-naphthol- 
disulphonic  acid  (R-acid),  it  yields  anMoU-red 

(v.    Azo-    COLOUBINO    UATTBBS).      A    mixtUTS  of 

orthanisidine  (2  mols.)  and  paraphenylenedia- 
mine  (1  mol.)  is  converted,  on  oxidation  with 
potassium  dichromate,  into  a  reddish  colouring 
matter   formerly   employed   under   the   name 


332 


ANISmiNE. 


Mfranisok  (Kalle  k  Co.,  D.  R.  P.  24229  of 
Oct.  27,  1882 ;  expired  Maroh,  1880).  Anisi. 
dine  is  used  for  making  chrome  fast  yellow 
G-6.  azoeosin  6  and  azocoohineal. 

Pftranlsldliie,  obtained  from  paranitranisole 
by  reduction  with  tin  and  hydrochloric  acid, 
crystaUiaes  in  prismB  which  mdt  at  55 '6^-56 '6® 
(Lossen,  Annalen,  175,  324)  and  boil  at  245°< 
246''  (Salkowaki,  Ber.  7, 1009) ;  243*'  at  700  mm. 
(Perkin,  Chem.  Soo.  Trans.  69,  1210) ;  p-anisi- 
dine,  o-sulphonic  acid,  prepared  by  boilW  the 
hydrogen  sulphate  of  p-animdine,  when  cuazo- 
tued  and  coupled  with  iS-naphthol,  yields  an  azo- 
compound  forming  red  lakes  with  baiyta, 
alumina,  &o.  (Aktiengesellschaft  fiir  Anilin- 
Fabrikation,  D.  R.  P.  14665). 

Chloranisidine,  when  diakotised  and  coupled 
with  iS-naphthol,  yields  a  red  compound  in- 
soluble in  water  (Julius,  Ludwigshafen  and 
Jahrmaht,  U.S.  Pat.  695812) ;  p-  and  m-nitro- 
anisidine,  when  diazotised  and  coupled  with 
i^naphthol,  yield  red  and  pink  dyestuffs  (Imray, 
East.  Pat.  25756 ;  J.  Soc.  Chem.  Lid.  1898, 1039  ; 
and  Freyss,  J.  Soc.  Chem.  Ind.  1901,  356) ; 
o-iodo-p-anisidine,  when  diazotised  and  treated 
with  naphthol  sulphonic  acid,  yields  a  red  d^e, 
similar  to  that  obtained  m>m  p-anisidme 
(Reverdin,  Ber.  29,  997). 

Anisidine  condenses  with  orthoformic  ester, 
and  the  resulting  compound  is  used  as  an 
anaesthetic  (Goldohsmidt,  £ng.  Pat.  9792;  J. 
Soc.  Chem.  Ind.  1899,  606). 

ANISOCHILUS  CARN0SU8  (WaU.).  An 
Indian  plant  belonging  to  the  Labiatie  and 
containing  a  volatile  oil.    Used  in  quinsy. 

ANISOLE.    Aniwil;  Mdhylphenyl  ether 

C,H,OCH,. 

Preparaiion. — ^Anisole  can  be  obtained  by  dis* 
tilling  anisic  acid  or  o-methoxybenzoic  acid  with 
baryta,  or  by  heating  i^tassium  phenate  with 
methyl  iodide  at  120°  (Cahours,  Ann.  Chim.  Phys. 
[3]  2,  274  ;  10,  353  ;  27,  439).  It  is  prepared 
by  passing  a  current  of  methyl  chloride  over  dry 
sodium  Senate  heated  at  190''>200''  (Vincent, 
Bull.  Soc.  chim.  40,  106),  and  by  heating  phenol 
with  methyl  alcohol  and  potassium  bismphate 
at  150''-160''  (Act.  Ges.  fur  Anil.-Fabrik. ; 
D.  R.  P.  23775).  It  has  been  synthesised  by 
fusing  sodium  benzene  sulphonate  with  sodium 
methoxide  (Moureu,  J.  Pharm.  Chim.  8,  v.  211). 

Properties. — ^It  is  a  colourless  ethereal  liquid, 
which  boils  at  155''-155'5''  at  7623  mm.  (Schiff, 
Annalen,  220,  105)  at  153*9"*  (corr.)  (Perkin, 
Chem.  Soc.  Trans.  69,  1240) ;  melts  at  —37*8'' 
(Von  Schneider,  Zeit.  Phys.  Chem.  19,  997) 
and  has  a  specific  gravity  0*991  at  IS"*  (v. 
Oils,  Essskhal). 

ANISOMELES  HALABARIOA  (R.  Br.).  A 
much-esteemed  Indian  plant  belonging  to  the 
Labiatse ;  an  infusion  of  the  leaves  is  used  in 
intermittent  fevers,  and  the  essential  oil  is 
applied  externally  in  rheumatism. 

ANISOTHEOBROMINE.  Trade  name  for  an 
addition  product  of  theobromine  sodium  and 
sodium  anisate. 

ANKERITE.  A  member  of  the  group  of 
rhombohedral  carbonates  containing  calcmm, 
magnesium,  and  iron,  with  sometimes  a  little 
manganese.  The  formula  is  like  that  of  dolomite 
with  the  magnesium  partly  replaced  by  iron ; 
in  normal  ankerite  it  Lb  CaCO,'Mg|Fe|COt.    The 


angle  between  adjacent  faces  of  the  rhombo- 
hedral cleavage  is  73°  48'.  D  2*95-3*1  ;  H 
3}-4.  The  mineral  forms  white,  greyish,  or 
brownish  deavage  zfaombs,  deavage  masses,  or 
granular  masses.  It  occurs  in  some  abundance 
with  chalybite  (FeCOj)  in  the  iron  mines  of 
Eisenerz  in  Styria,  Londonderry  in  Nova  Scotia, 
and  in  northern  New  Tork.  The  white,  thin 
platy  seams  often  seen  in  coal  consiBt  usually  of 
ankerite.  L.  J.  S. 

AHKOOL,  AKOLA,  DHERA,  BABK|  The 
root  bark  of  Alangium  Lamarekii  (Thw.)»  one  of 
the  Comaces,  used  in  leprosy  and  ikin-diaeasee 
(Dymook,  Phann.  J.  [3]  9,  1017). 

AHKATTO.  This  is  derived  from  the  fruit 
of  the  Biini  areHana  (Linn.),  a  shrub  found 
native  in  Central  America,  and  cultivated  in 
Brazil*  Guiana,  Mexico,  the  Antilles,  and  India. 

To  prepare  the  dyestufif ,  the  seeds  and  pulp 
are  removed  from  the  mature  fmit,  maoerated 
with  water,  and  the  mixture  is  left  to  ferment. 
The  product  is  strained  through  a  sieve,  and  the 
colouring  matter  which  settiM  out  is  ooUscted, 
partially  evaporated  h^  heat,  then  plaoed  in 
Doxes,  and  filially  dried  in  the  sun. 

Annatto  comes  into  the  market  in  the  form 
of  cakes,  and  among  the  different  varietiee 
Cayenne  annatto  is  the  most  esteemed,  and  is 
considared  to  be  the  richest  in  colouring  matter. 
It  should  contain  from  10  to  12  p.c.  of  the  pure 
dye,  and  not  more  than  5  p.o.  of  ash,  whereas 
the  amount  of  colouring  matter  in  the  Bengal 
product  is  frequently  lower  than  6  p.o. 

In  1848  Dumontal  devised  a  new  method  for 
the  preparation  of  annatto,  in  which  fermenta- 
tion is  avoided,  and  the  pulp  is  simply  washed 
out  from  the  capsules  and  off  the  seeds.  This 
product  known  as  hixin  is  said  to  be  five  to 
six  times  more  valuable  than  ordinary  annatto 
(Crookes,  Dyeing  and  Calioo-Printing). 

The  colouring  matters  of  this  dyestnff  were 
first  investigated  by  Chevreul  (Le9on8  de 
Chimie  appliqu^  k  la  Teintuie),  who  isolated 
two  substances,  one  yellow,  which  was  called 
orreUin,  soluble  in  water,  and  a  second,  6mii, 
which  is  red  and  ve^  sparingl  jr  soluble. 

Bizin,  the  usenil  oolouimg  matter,  was 
subsequently  examined  by  numerous  chemists, 
who  were  only  successful  in  preparing  it  as  an 
amorphous  powder,  and  its  isolation  in  a  crystal- 
line condition  was  first  achieved  by  Etti  (Ber. 
7,  446  ;   11,  804). 

Etti  digested  1*5  kilos  of  purified  annatto 
with  a  solution  of  160  grams  of  calcined  soda 
ash  in  2*5  kilos  of  80  p.c.  alcohol  on  the  water- 
bath  at  80^  The  mixture  was  filtered  and  the 
residue  pressed  between  warm  plates,  and  asain 
extracted  with  1*5  kilos  of  warm  60  p.c.  alcohol. 

The  alcoholic  filtrate  was  diluted  with  half 
its  volume  of  water,  concentrated,  sodium 
carbonate  solution  added,  and  the  crystalline 
precipitate  of  sodium  bixin  was  collected  after 
sevenl  days,  and  pressed.  The  product  purified 
by  solution  in  60  p.c.  alcohol  at  70''-80^  and 
reprecipitation  with  sodium  carbonate  was  finally 
made  into  a  cream  with  alcohol,  and  this,  when 
neutralised  with  hydrochloric  acid,  yielded 
crystalline  bixin. 

A  simpler  method  has  been  more  reoentlv 
devised  by  Zwick  (Ber.  30,  1972).  WeU-dried 
annatto  is  extracted  for  twenty-four  hours  with 
boiling  chloroform,  the  extract  evaporated,  and 


ANNATTO. 


3S3 


the  reaidiie  thoroughly  exhAosted  with  ligroin. 
The  prodnot  is  orjrstalliaed  from  ohkmuorm, 
and  after  washing  with  ligroin  is  repeatedly 
reomUiUiaed  from  the  former  solvent. 

Bixin  O^JSL^O^  (Etti,  Ic;  Marohlewski 
and  Matejko,  Ghem.  Zentr.  1906  [ii]  1266)  con- 
sists of  brown-red  or  deep-red  rhombic  crystals, 
which,  when  slowly  heated,  melt  at  191*6^,  and 
when  rapidly  heated  at  196®.  It  is  sparingly 
actable  in  the  nsoal  solyents,  and  of  these  it  is 
most  readily  dissolved  by  chlorof oim  or  aloohoL 
Concentrated  salphnzio  aoid  diasolYes  bixin 
with  a  comflower-blae  colouration,  and  this 
reactioii  is  siven  by  minnte  tnoes  of  the  sub- 
stance (e/.  (&odn  and  Nycanthin). 

Manomdkm  hixin  0t,HM0tNa+2H,0  is 
best  prepared  by  dinolying  10  srams  of  bixin 
in  a  solution  of  1*2  grams  of  soouum  carbonate 
in  300  c.e.  of  12  p.a  alcohol  at  TO*"  (Etti,  Zwick). 
It  is  deposited  on  cooling  in  dark-red  iridescent 
crystals^  and«oan  be  obtained  in  the  anhydrous 
conditum  by  lecrystalliaation  from  70  p.c. 
alcohol  (Marohlewski  and  Matojko). 

Digodium  bixin  Gt8H,.Oa^a,+2H.O  is  ob- 
tained when  20  grams  of  bixin  is  dissolyed  in  a 
solution  ol  10  grams  sodium  carbonate  in  600  c.o. 
of  boiluig  12  p.c.  alcohoL  It  consists  of  a  dark- 
red  amoiphous  powder  (Etti).  Monofakunum 
bixin  0«aHttOftK+H2|0  and  dipotOBnum  bixin 
CtsHg,0|Kt+2HaO  have  also  been  prepared. 

Bixin  contains  one  methoxyl  group.  Dis- 
tilled with  sine-dust,  bixin  yields,  according  to 
Etti,  metaxylene,  mdaethylxylene,  and  a  hydro- 
carixm  GuH^^,  b.p.  270''-280''. 

According  to  Zwick,  bixin  is  readily  reduced 
by  sodium  amalgam,  and  a  compound  C, ,H4o07 
is  thus  producM.  Marchlewski  and  Matejko, 
on  the  other  hand,  studied  the  action  of  zinc- 
dust  and  acetic  acid,  and  obtained  in  tius 
manner  an  orange-coloured  crystalline  substance 
which  poeseseed  a  strong  metallic  lustre.    When 


slowly  neated  it  melts  at  200*5°,  but  if  the  opera- 
tion u  carried  out  rapidly,  at  208*'-210''.  This 
compound  is  evidently  of  an  unstable  nature, 
for  whereas  when  freshly  nrepared  it  gives 
C=75'4,  Hs7'7  p.0.,  on  stanoing  for  some  da3rs 
in  the  air  it  becomes  colourless  and  then  gives 
C=58*6,  HsaS-S  p.c.  At  100"*  this  change  occun 
more  rapidly. 

More  recently  there  has  been  much  con- 
troveny  as  to  the  correct  formula  for  bixin. 

Van  Hasselt  (Ghem.  Weekblad,  1909,  6,  480) 
contends  that  pure  bixin,  which  melts  at  189**, 
is  G.9H,40{  rather  than  CgsHnOs,  as  proposed 
by  Etti  (U.).  If  heated  at  igO""  in  a  current  of 
hydrogen,  1  gram  mol.  of  bixin  yields  1  gram 
moL  en  m-xylene,  and  no  other  volatile  product, 
though  it  is  not  to  be  considered  that  a  m-xylene 
nucleus  exists  as  such  in  the  bixin  molecule. 
No  pahnitic  add  could  be  obtained  from  bixin 
as  Zwiok  suggests.  Whereas  both  Etti  and 
Zwick  descri]^  mono-  and  dipotaasium  salts 
of  bixin,  the  latter  is  not  in  reality  a  compound 
of  bixin,  but  of  a  new  substance  termed  norbixin 
OKi/aaHtoOt'OK,  produced  by  a  substitution 
oi  a  methyl  of  the  metiioxy  group  present  in  the 
former  by  potassium  (Bee.  trav.  chim.  1911, 
20,  1).  Norbixin  G|,H,aOs  consists  of  a  light 
red-coloured  crystalline  powder  which  decom- 
poses at  about  240**,  and  is  distinguished  from 
bixin  by  its  insolubility  in  chloroform. 

Potassium   bixinato  with  methyl  sulphate 


gives  bixin  mdhifl  dher  B(OMe)s,  or  GjoHatOf, 
plates,  m.p.  166^  (1909),  and  the  same  compound 
IS  obtained  when  a  solution  of  bixin  in  methyl 
alcohol  iB  treated  with  potassium  hydroxide  and 
methyl  sulphate  (1911).  On  treatment  with 
potassium  hydroxide,  bixin  methyl  ether  is  con- 
verted into  norbixin.  Bixin  ethyl  ether  GtiHaaOt, 
violet  orystalB,  melts  at  138°,  and  by  metnylation 
forms  norbixin  methyl  ethyl  ether  OMe'BOEt, 
ntp.  149°. 

.  Potassium  norbixin,  obtained  from  bixin 
and  alooholic  potash,  gives  with  ethyl  sulphate 
norbixin  dieikfi  ether  G„HMOa(OEt)„  m.p.  121°, 
together  with  norbixin  ethyl  e&er 

G„H,oO,(OEt)(OH). 
m.p.  176°. 

The  relationship  between  norbixin,  bixin, 
and  bixin  methyl  ether  is  shown  as  follows : — 

OH-BOH      OHBOMe      OMeBOMe 

According  to  Hasselt,  iao^ixin  methyl  ether, 
m.p.  149°,  IS  produced  when  norbixin  ethyl 
ether  is  methylated,  and  it  is  thus  evident  that 
the  two  hydroxyls  c^  norbixin  are  not  symmetri- 
callv  situated.  IdtMxin  GH'B'OMe,  melts  at 
178  ,  and  may  be  obtained  by  the  partial 
hydrolysis  of  bixin  methyl  ether,  and  this,  by 
ethylation  with  ethyl  sulphate,  gives  norbixin 
diethyl  ether,  m.p.  121°,  tne  methyl  bein^  thus 
replaced  by  an  ethyl  group.  Iso-bixin  is  dis- 
tinguished from  bixin  oy  the  greater  stability 
of  its  methyl  ^roup  in  presence  of  potassium 
hydroxide  solution. 

The  product  of  the  reduction  of  bixin  ob- 
tained oy  Marchlewski  and  Matejko,  and 
referred  to  above,  is  considered  by  van  Hasselt 
to  consiBt  of  dihydrdbixin  GitHgcOs.  He  has 
also  described  dihydrdbixin  methyl  ether  GmH,  fi  s, 
m.p.  174°;  dihydro-iso-bixin  C^^E^fit,  m.p. 
190° ;  and  dihydro-norbixin  C^^R^fig,  which 
decomposes  at  &5°. 

By  the  action  of  bromine,  bixin  yields  bixin 
decabromidt  G,sH,40(Brio,  whereas  bixin  methyl 
ether  yields  the  snalogous  compound 

CtoHtfOfBrio, 

and  both  these  substances  are  colourless  amor- 
phous powders.  Attempts  to  benzoylate  or 
acetvlate  bixin  were  unsuccessful. 

On  the  other  hand,  Heiduschka  and  Biffart 
(Areh.  Pharm.  1911,  240,  48)  consider  that  the 
old  formula  GisHa^Os  for  bixin  is  preferable  to 
that  of  G|tH(40s,  advocated  by  van  Hasselt. 
Bixin,  by  the  action  of  bromine  in  the  presence 
of  chloroform,  gives  the  compound  O^fi^fi  sBrio, 
4HBr,  melting  at  143°,  and  this  by  heating  at 
100°  is  converted  into  the  *decabromide 
Gt8H|40|Br]A,  which  can  be  obtained  crystal- 
line from  alcohol,  but  is  unstable.  By  the 
action  of  chlorine  on  bixin  and  norbixin  respec- 
tively, the  amorphous  compounds  GigHg^OsGlio* 
4HG1  and  Ga7H,,0,Glio,  4HG1  can  be  prepared. 

Van  Hasselt  (Bee.  trav.  chim.  1914,  33,  192), 
however,  maintains  that  his  formula  for  bixin 
GttHa«0|  is  correct,  and  states  that  the  dis- 
crepancy shown  by  the  results  of  his  own  work 
ana  that  of  Heiduschka  and  Bififart  arises  from 
the  fact  that  bixin  is  readily  susceptible  to 
oxidation  with  the  formation  of  amorphous 
products.  The  bixin  of  these  latter  authors 
was  not  completely  pure,  and  it  is  quite  correct 
that  specimens   which  are  purified  by   their 


334 


ANNATTO. 


method  ffive  figures  in  harmony  with  the  older 
formula  CagHi^Ofi.  Asain,  the  analytical  num- 
bers ffiven  by  Marchlewski  and  Matejko  for 
hydroDixin  are  explainable  if  bixin  is  given  the 
formula  C29H,405. 

A  new  formula  C.,Ha70t*0Me  for  bixin  was 
now  suggested  by  Herzig,  Faltis,  and  fiiizzan 
(Monat£  1914,  36,  997),  who  state  that  it  is 
difficult  to  correctly  analyse  bixin  unless  special 
precautions  are  adopted.  Dihydrobixin,  the 
product  of  the  action  of  zinc-dust  and  acetic 
acid  on  bixin,  melts  at  178'*-179'',  whereas  the 
methyl  ether  obtained  by  means  of  diazomethane 
and  bixin,  or  methyl  sulphate  and  potassium 
bixin,  melts  at  ISS*". 

Though,  as  Hasselt  states,  bixin  at  190''-200'' 
yields  m-xylene,  the  reaction  is  hardly  of  a 

auantitatiye  nature,  in  that  the  crude  oil, 
liough  containing  this  hydrocarbon,  possesses 
no  constant  boiling-pomt.  Binkes  TChem. 
Weekblad)  suggests  uiat  the  formula  of  bixin 
is  Ca7H,,0«,  tnough  Herzig  and  Faltis  (Ber. 
1917,  60,  927)  in  reply,  reiterate  that  the  expres- 
sion C««Hm04  is  to  be  regarded  as  correct,  and 
that  the  real  difficulty  hes  in  the  combustion 
of  this  colouring  matter.  Heidusohka  and 
Panzer  (Ber.  1917,  60,  646)  point  out,  however, 
as  the  result  of  further  investigation,  that  the 
main  difficulty  is  in  the  purification  of  the 
substance.  The  most  satisfactory  products  are 
those  obtained  by  mecms  of  acetone  and  ethyl 
acetate,  which,  when  analysed,  give  figures 
agreeing  with  the  formula  0.|H,o04. 

When  ozonised,  methyl  bixin  forms  an 
ozonide,  and  this  by  distillation,  and  partly  by 
the  action  of  calcium  carbonate,  gives  among 
other  products,  methyl- fi-acetyl  acrylate,  and  a 
crystalline  compound  CgHioOg,  m.p.  86°,  which 
yields  an  oxime,  m.p.  106%  and  may  be  the 
methyl  ester  of  a  ketonic  acid.  Methylbixin 
thus  appears  to  contain  the  linkage 

C-MeOH :  CHC'OMo 

(Rinkes  and  Hasslet,  Ohem.  Weekblad,  1916, 13, 
244,  and  14,  888). 

Sodium  hyposulphite  reduces  bhdn  to  a- 
hydrobizin,  red  needles,  melting  about  200**, 
norbixin  to  a-hydronorhixin,  violet  crystals,  and 
methylbixin  to  a-hydrameihylbixin,  violet  needles, 
m.p.  190*^-192^ 

On  the  other  hand,  with  titanium  sesqui- 
oxide,  bixin  gives  fi-hydrobixin,  norbixin  $• 
hydranorbixin,  and  methylbixin  fi-hydromdhyl- 
bixin,  the  latter  of  which  melts  at  170°.  By  &e 
action  of  zinc-dust  both  a-  and  iS-hydrobixins 
aie  converted  into  the  same  y-hydrbbixin,  yellow 
crystals,  m.p.  207°  (van  Hasselt,  ibid.  1916,  13, 
429). 

In  a  furth.>r  communication  Heiduschka 
and  Pauzer  fBer.  1917,  60,  1626)  again  maintain 
the  probability  of  the  formula  Ot,H,o04  for 
bixin. 

Dyeing  Properties. — Annatto  is  still  em- 
ployed to  a  fair  extent  for  colouring  oils  and 
Dutter,  but  is  almost  extinct  as  a  dyestuff  in 
this  country.  As  the  oranse-red  colour  which 
it  yields  is  extremely  fugitive  to  light,  it  has 
~kt  no  time  been  very  extensively  used.  On 
^her  hand,  it  resists  the  action  of  soap  and 
acids  very  weU. 
order  to  dye  cotton,  the  annatto  is  first 


dissolved  in  a  boiling  solution  of  carbonate  of 
soda,  and  the  goods  are  then  entered  and  left 
in  the  bath  for  a  quarter  of  an  hour.  They  are 
subsequently  pressed  out,  and  washed  in  slightly 
acidulated  water  or  alum  solution. 

For  silk,  the  bath  is  made  up  with  equal 
parts  of  annatto  and  sodium  carbonate;  soap 
IS  also  usually  added,  and  the  dyeing  is  continued 
at  60°  for  al>out  an  hour,  according  to  the  shade 
required.  The  colour  produced  can  be  rendered 
somewhat  more  yellow  by  passing  the  fabric 
through  a  weak  solution  oi  tutaric  acid. 

Wool  is  dyed  at  80°- 100°  without  any 
addition  to  the  bath.  A.  G.  P. 

ANNEALING.  {Le  recuit,  Fr. ;  das  Ankusen, 
Qer.)  A  process  which  is  appUed  princi- 
pally to  glass  and  metals  for  the  purpose  of 
renaerin|(  them  softer  or  less  bnttle.  The 
process  itself  always  consists  in  the  application 
of  heat  for  a  period  of  time,  which  may  vazy 
from  a  few  minutes  to  many  homy,  and  which 
may  be  followed  by  very  slow  oooling;  the 
object  of  the  process  is  to  permit  the  material 
to  attain  approximate  equilibrium  in  r^ard 
to  its  internal  structure.  This  state  of  normal 
internal  equilibrium  may  be  disturbed  either 
by  the  effects  of  rapid  cooling  or  by  the  applica- 
tion of  mechanical  deformation.  The  former 
is  most  frequently  met  with  in  glass,  and  in 
large  metal  castings,  while  the  latter  ii  found  in 
*  wrought  *  metal  of  all  kinds. 

In  the  case  of  substances  which  are  poor 
conductors  of  heat,  such  as  glass,  and  also  in 
masses  of  metal  which  are  so  uige  that  thermal 
conductivity  cannot  produce  reasonable  uni- 
formity of  temperature,  relatively  rapid  cooling 
sets  up  severe  stresses,  owing  to  the  fact  that 
the  outer  or  most  rapidl]^  cooled  layers  solidify 
or  become  hard  ana  rigid  first;  subsequently 
the  internal  portions  of  the  mass  endeavour  to 
contract  in  cooling,  but  find  themselves  con- 
strained by  their  attachment  to  a  relatively 
rigid  external  envelope;  the  tendency  to 
thermal  contraction  ia  therefore  overcome  by 
severe  tensional  stresses.  A  body  in  this  con- 
dition, while  it  may  present  the  phenomenal 
strength  of  a  *  Rupert's  drop,*  is  liable  to  sudden 
fracture,  particularly  if  the  surface  is  out  or 
broken.  The  annealing  of  glass  has  been 
studied  with  great  care  (Twyman,  Joum.  Soc. 
Glass  Technology,  vol.  i.  1,  pp.  61.-74),  and  it  has 
been  shown  that  glass  behaves  as  a  true  fluid 
whose  change  of  viscosity  with  temperature 
follows  an  exponential  law,  so  that  the  viwsosity 
is  halved  for  ecush  rise  of  temperature  of  8°  U. 
If,  then,  a  piece  of  glass  has  Seen  so  cooled  as 
to  be  heavily  stressed  internally,  these  stresses 
will  be  released  if  the  temperature  is  nused  to 
such  a  point  that  the  viscosity  becomes  low 
enough  for  appreciable  flow  to  take  place  in  a 
few  seconds.  The  temperature  required  for 
this  purpose  may  be  demied  as  *  the  A.im Ailing 
temperature,*  and  although  it  is  not  a  definite 
critical  temperature,  the  rapidity  with  which 
the  viscosity  or  ^  stiffness  '  of  the  glass  changes 
with  temperature  makes  it  possible  to  approxi- 
mate to  a  definite  '  annealing  temperatiue  *  for 
each  kind  of  glass.  Experimentally  this  may 
be  done  by  heatmg  an  internally-strained  speci- 
men of  the  glass  in  an  electric  tube-funmoe  while 
keeping  it  under  observation  by  means  of  a 
beain  of  plane-polaiised  light  passing  through 


ANTHEMOL. 


835 


the  glass  while  in  the  furnace-tube.  When  thus 
examined  under  'crossed  Nicols*  the  presence 
of  internal  stress  makes  itself  apparent  by  a 
more  or  less  well-defined  cross,  or  at  least  by 
light  and  dark  shading.  This  appearance 
remains  practicall^r  unchanged  (unless  the  heating 
is  very  slow),  untd  the  annealing  temperature  is 
reached,  when  the  markings  suddenly  disappear. 
Such  glass  can  then  be  fulfy  annealed  Ijy  heating 
to  this  temperature,  followed  by  cooling  in  such 
a  manner  that  no  fresh  internal  stresses  «re  set 
up.  Tins  usually  implies  very  slow  cooling 
until  the  glass  is  stiff  enough  to  be  free  from 
further  nsk  in  this  respect.  It  should  be 
noted,  however,  that  alow  cooling  in  itself  is  of 
no  special  advantage ;  all  that  is  required  is 
the  maintenance  of  the  greatest  possible  unifor- 
mity of  temperature  t&oufhout  the  mass  so 
that  all  parts  of  it  shall  co^  as  nearly  as  mav 
be  simultaneously.  In  bodies  like  glass,  which 
are  poor  conductors  of  heat,  this  can  only  be 
attuned  by  extremely  slow  cooling,  exc^t 
where  very  thin  pieces  are  concerned.  In  the 
case  of  metals,  which  are  good  conductors  of 
heat,  extremely  slow  cooling  is  not  necessary 
in  rader  to  avoid  the  development  of  severe 
internal  stiesoes,  and  as  very  slow  cooling  is 
undesirable  in  most  metals  because  of  the 
tendency  to  produce  coarse  and  weak  micro- 
structures,  it  is  never  employed  intentionally. 
Annealing  is,  in  fact,  generally  applied  to  metals 
for  other  purposes. 

Metals  in  the  east  or  other  'normal*  con- 
dition consist  of  aggregates  of  minute  crystals 
of  approximately  equal  dimensions  in  all  direc- 
tions ;  when  metal  is  mechanically  deformed, 
as  by  hammering,  rolling,  or  other  working 
process  carried  on  in  the  cold,  these  minute 
crystals  are  elongated  in  the  same  general  sense 
as  the  mass  of  which  they  form  part,  and  this 
deformation  of  the  crystals  is  accompanied  by 
the  well-known  hardening  of  the  metal  under 
cold  work.  This  is  due  in  part  to  the  internal 
rearrangement  which  each  crystal  undergoes, 
and  in  part  to  the  partial  and  local  destruction 
of  the  crystalline  arrangement  itself,  accom- 
pani^  by  the  formation  of  a  hard  amorphous 
phase'  (Ewing  and  Boeenhain,  Phil.  Trans. 

1899,  ser.  A.  cxiiL  353-376;  BeUby,  Phil. 
Mag.  1894).  When  the  metal  is  subsequently 
annealed,  i.e.  heated  to  a  suitable  temperature, 
the  metal  *  reorystallises/  the  crystals  rearrange 
themselves,  and  the  original  condition  is  ap- 
proximately'restored.  In  some  metals  the  mole- 
cular mobility  is  such  that  recrystallisation  takes 

eoe  slowly  even  at  the  ordinary  temperature 
A:    Ewing    and   Bosenhain,    Phil.    Trans. 

1900,  cxcv.  279-301;  brass:  Cohen,  Rev. 
general  des  Sciences,  April  30,  1910) ;  but  in 
the  greater  number  of  cases  a  lugh  tempera- 
ture IS  required.  In  the  great  majority  of  pure 
metals,  and  in  some  alloys,  the  rate  of  subse- 
quent cooling  is  immaterial  so  far  as  the  softening 
effect  is  concerned ;  but  in  certain  metals  and 
in  a  large  number  of  alloys  either  allotropic 
or  other  changes  take  place  during  gradual 
cooling,  and  these  transformations  are  more  or 
lees  iimibited  by  rapid  cooling ;  in  such  metals 
the  rate  of  cooling  through  the  '  critical  tempera- 
tures *  at  which  these  changes  occur  is  of  material 
importance.  The  most  striking  example  is 
found  in  carbon  steels  containing  upwards  of 


i  p.c.  of  carbon,  which  are  moderately  soft  i' 
cooled  slowly  down  to  a  temperature  of  660^ 
but  become  exceedingly  hard  if  suddenly  cooled 
from  a  temperature  above  700®.  In  the  case  of 
hardened  tool  steel,  the  process  of  ^^wnAnlmg 
consists  in  raising  the  steel  to  such  a  temperature 
(above  700°)  that  the  changes  which  were 
suppressed  when  the  steel  was  hardened  by 
queoching  are  allowed  to  take  place  during  the 
heating  and  cooling  process. 

In  modem  *m^  speed  tool  steels*  the 
presence  of  a  considerable  percentage  of  tungsten 
(16-20  p.c.)  or  of  molybdnrnm,  has  the  effect  of 
raising  the  annealing  or  softening  temperature 
very  considerably.  I^loi^ed  exposure  to  a 
temperature  near  900°  C.  is  required  to  bring 
about  full  softening,  and  tools  made  of  these 
steels  retain  their  cutting  edge  at  a  dull  red 
heat  (near  700°  C),  while  a  carbon  steel  becomes 
useless  at  a  much  lower  temperature  (near 
400°  C).  It  is  this  property  which  makes  it 
possible  to  use  '  high  sp^  *  tools  for  working 
at  rates  which  generate  far  more  heat  than 
carbon  steel  tools  could  withstand. 

A  special  form  of  annealing  known  as 
'  normau8in£  *  is  now  frequently  applied  to  nuld 
steel  with  highly  beneficial  results.  The  pro- 
cess consists  in  heating  the  steel  to  a  temperature 
just  above  the  highest  criticcd  point  (from 
830°  0.  to  900°  0.,  according  to  the  carbon 
content),  keeping  it  there  just  long  enough  to 
ensure  tiiat  the  whole  mass  has  attained  the 
desired  temperature,  and  then  allowing  the  steel 
to  cool  rapidly,  usually  by  taking  it  out  of  the 
furnace  and  cooling  it  in  the  air.  This  treat- 
ment results  in  the  refining  of  the  structure  of 
the  steel  {see  Mstalloora.phy)  with  a  very  con- 
siderable concomitant  improvement  in  the 
physical  properties,  more  especially  as  shown 
Dy  the  notched-bar  impact  test. 

In  many  metals  the  annealing  process  is 
liable  to  be  complicated  by  tiie  effects  of 
chemical  actions  between  the  metal  and  its 
solid  or  gaseous  surroundings,  as  well  as  by  the 
effects  of  the  growth  of  the  constituent  crystals 
of  the  metal ;  at  hi^h  temperatures  these 
crystals  tend  to  increase  m  skec,  and  tiie  resulting 
coarsening  of  the  ^rain  of  the  metal  leads  to 
a  deterioration  m  mechanical  properties. 
Annealing  at  an  unduly  high  temperature  or 
for  too  long  a  time  thus  oecomes  *  over-heating,* 
and* is  injurious  to  almost  all  metals  and  alloys, . 
notably  to  steel  and  brass.  W.  R. 

AnODYNIMB.  Identical  with  antipyrine 
{q.v.). 

ANOGON*  Trade  name  for  the  mercury 
salt  of  2*6-diiodophenol-4-sulphonic  add. 

ANONA  MURICATA  (Linn.).  A  decoction 
of  the  root  is  used  as  an  antidote  for  fish-poison- 
ing, and  the  bark  serves  as  an  astringent.  The 
leaves  are  useful  in  softening  abscesses,  and  tern 
the  seeds  a  wine  can  be  prepared  which  is  said 
to  be  beneficial  in  cases  of  diarrhoea  (Ohem. 
Zeit.  10,  433;  J.  Soc.  Ghem.  Tnd.  5,  332). 

ANORTHTTE  v.  Fslspab. 

ANOZOL.  Trade  name  for  a  preparation 
of  iodoform  deodorised  by  10-20  p.c.  of  thymoL 

ANTACEDIN.  Calcium  doceharaU. 

ANTALGINE.    Trade     name     for     sallcyl- 
aldehyde-a-methylphenyl  hydrazone.    Used  lor 
neuralgia  and  rheumatism. 
ANTHEMOL  v,  CAMFBOBa. 


336 


ANTHTONE. 


ANTHIONE.  Trade  name  for  a  solution  of 
potasBium  persulphate.  Employed  as  a  photo- 
graphic reagent. 

AMTHOCYANIMS.  Many  brilliant  natural 
effects  are  due  to  the  colouring  matters  of  this 
group.  They  have  been  the  subject  of  investiga- 
tion for  many  ^ears  past,  but  it  ia  only  since 
the  work  of  WiUstatter  uid  Everest  (Annalen, 
1913,  401,  189)  that  chemical  knowledge  ooa\ 
ceming  them  has  been  placed  upon  a  satis- 
factory  basis. 

Maiquart  (Die  Farben  der  Bliiten,  Bonn, 
1835)  first  introduced  the  term  an^tocyan,  using 
it  for  the  blue  pigments  present  in  flowers; 
gradually,  however^the  term  became  extended 
to  include  aU  red,  purple,  and  blue  flower, 
berry,  or  leal  sap-pigments,  whilst  the  terms 
afUhocyanin  and  anihocifanidin  were  intro- 
duced by  Willstatter  and  Everest  to  designate 
Uie  glucoeide  and  non-glucoside  anthocyan 
pigments  respectively. 

In  1837,  Berzelius  (Annalen,  21,  262) 
attempted  to  isolate  and  purify  various  pigments 
of  this  class,  and  his  method,  which  involved  the 
use  of  lead  salts,  was  adopted  by  many  later  in- 
vestigators, but  rarely  with  any  success.  Morot 
(Annates  des  Science  nat.  [3]  13, 160  [1840-1860]) 
attempted  to  obtain  a  pure  pigment  from  the 
cornflower,  whilst  Fremy  and  (3oez  (J.  Pharm. 
Ghim.  [3]  25,  249)  worked  on  various  flowers, 
indudinff  the  coniflower,  violet,  iris,  dahlia, 
rose,  and  peony,  and  concluded  that  sJl  antho- 
cyan colours  were  produced  by  a  angle  pigment 
which  they  called  Cyanin,  (This  name  was 
ffiven  to  the  cornflower  pigment  in  J9I3  bv 
Willstatter  and  Everest.)  m  connection  with 
the  supposed  identity  of  all  anthocyan  pigments 
the  work  of  Overton  (Pring.  Jahrber.  t,  wiss. 
Bot.  1899,  33,  222),  of  Weigert  (Jahresber. 
d.  k.  k.  onol.  und  pomol.  Lchranstalt  in  Klos 
temeuberg,  1894-1895),  and  the  earlier  work  of 
Beredius  (^c),  Fremy  and  Glo&  (Z.c.),  Filhol 
(Compt.  rend.  39,  194 ;  J.  pr.  Chem.  1864,  63, 
78),  Wigand  (Bot.  Zitt.  1862,  123),  Hansen 
(Die  Farbstoffe  der  Bluten  and  Fruohten, 
Wiixxbuzff,  1884,  8),  and  Wiesner  (Bok  Ztg. 
1862,  392),  should  be  referred  to. 

Filhol  (U.  1864)  and  Monen  (1869)  carried 
out  *a  Bomber  of  qualitative  investigations 
bearing  upon  the  formation  of  pigments  in 
flowers. 

Work  of  a  more  definitelv  quantitative 
character  was  attempted  by  GUna^  (Compt. 
rend.  47,  268 ;  Jahrber.  1868,  476),  using  red 
wine»  and  Senier  (Jahrber.  1878,  970),  using 
roM  poBtca,  and  this  was  followed  by  that  of 
Heise  {cf.  Chem.  Centrblt.  1889,  ii.  963 ;  and 
1894,  ii.  846)  and  Qlan  (Dissertation,  Erlangen, 
1892),  in  which  the  pigments  of  red  wine,  the 
bUbeny,  and  flowers  of  the  deep-red  hollyhock 
were  examined,  and  as  the  result  of  this  the 
question  of  the  elucosidal  nature  of  these 
pigments  was  raised,  a  question  first  settled  by 
the  work  of  Willstatter  and  Everest  in  1913. 

The  first  description  of  an  anthocyan  pigment 
in  crystalline  condition  was  published  by 
Griffiths  (Ber.  36,  3969;  Chem.  News,  1903, 
88,  249),  the  pigment  beins  that  of  the  scarlet 
pelaiffonium.  Someithat  later,  MoUsoh  (Bot. 
Ztff.  1906,  146)  obtained  the  same,  and  several 
other  piffments  of  the  series,  in  crystal- 
line  con£tion   on   microscope-slides,   and   lus 


work  led  Grafo  (Sitzber.  k.  Akad.  d.  Wiss. 
Wien,  1906,  976;  1909,  1033;  and  1911,  765) 
to  attempt  to  obtain  similar  results  on  a  large 
scale,  but  although  he  succeeded  in  procuring 
crystalline  compounds  in  a  number  of  cases, 
Ms  chemical  results  have  been  largely  disproved 
by  the  later  work  of  Willstatter  and  his  colla- 
borators. 

A  considerable  amount  of  investigation  has 
been  canned  out  upon  the  relationship  existing 
between  the  anthocyan  pigments  and  the  yellow 
sap  colouring  matters — ^flavoner  and  flavonols. 
Hope  (Trans.  Boy.  Soc.  Ed.  1836)  developed 
ideas  concerning  this  matter;  Morot  {I.e.),  as 
also  Filhol  (2.C.),  touched  upon  it,  whereas 
Fremy  and  Clote  (2.e.)  criticised  the  drawing  of 
conclusions  as  to  such  relationships  whilst  so 
little  was  known  concerning  the  pigments 
involved.  Martens  (Ic.)  sugmted  that  the 
yellow  and  red  sap-pigments  nave  their  origin 
in  a  faintly  yellow-coloured  substance  produced 
in  the  sap  of  all  plants  and  which  passes  by 
oxidation — ^particularly  in  light — ^into  the  yelfow 
sap  pigments,  and  that  these,  by  further 
oxidation  and  light,  pass  in  their  turn  into 
anthocyans.  As  the  result  of  much  botanical 
work,  theories  have  been  put  forward  by 
Wheldale,  by  Keeble,  Armstrong,  and  Jones, 
and  by  others,  which  resemble  t£bt  of  Martens 
in  that  oxidation  of  the  yeUow  sap  pigments 
— ^flavones  or  flavonols— is  considered  to  be 
one  of  the  essential  stens  in  the  formation  of 
anthocyan  pigments.  Tnese  ideas,  which  were 
becoming  very  generally  accepted,  have  been 
dinroved  by  Everest  (Proc.  Koy.  Soa  1914, 
B.  87, 444 ;  and  1914,  B.  88, 326),  who  succeeded 
in  discovering  the  real  relationship  that  exists 
between  these  two  groups  of  pigments,  and  the 
manner  in  which  the  yellow  sap  pigments  could 
be  converted  into  anthocyanins.  He  showed 
that  anthooyanidins  are  produced  by  reduction 
of  flavonols,  followed  by  spontaneous  oxonium- 
salt  formation  and  dehydration,  a  series  of 
changes  that  may  be  expressed  thus : — 


/^\ 


/ 


OH 


\^.^0H   \ 


OH 
OH 


I 

0 


FlavonoL 


HO— 


+H, 


—OH 


O     /\ 
H    H     OH 

H     a 


•fKCl 


\/\n--C-0 


CB 

-OH 


O 
H 


H   OH 


\ 


OH 


ANTHOOYANINS. 


837 


In  like  manner  he  obtained  anthooyanins 
when  ^Incoridea  of  the  flavonols  were  used. 
The  evidence  thna  obtained  by  synthedfl,  and 
the  stmctnre  propoaed  by  Evereat  were  in  oom- 
plete  agreement  with  the  resnlta  of  analytioal 
woik,  carried  oat  independently  and  oononr- 
rently,  by  Willst&tter  and  his  collaborators  in 
the  extension  of  their  work  on  the  anthoovan 
pigments,  and  they,  after  repeating  the  work  of 
Everest,  confirmed  it  (Sitzber.  d.  EL  Akad. 
Wiss.  Berlin,  1914, 769),  and  in  this  way  obtained 
synthetao  <nranidin  chloride  and  proved  it  to 
be  identical  with  Willstatter  and  Everest's 
cyanidin  chloride,  obtained  from  the  cornflower. 
In  connection  with  the  production  of  anthocyans 
from  flavone  derivatives,  the  following  papers 
should  also  be  noted,  viz.  Stein,  J.  pr.  Chem. 
1862  and  1863;  Hlasiwetz  and  Pflaondler, 
Sitaber.  Wiener  Akad.  Wiss.  mat.-natw.  Klasse. 
1904;  Watson,  Chem.  Soo.  Trann.  1914,  106, 
389;  Combes,  Compt.  rend.  1913,  167,  1002, 
and  1454. 

A  farther  interesting  synthesis  of  an  antho- 
cyanidin  (pelaigonidin)  has  since  been  carried 
oat  by  Willstatter  and  Zechmeister  (Sitzber. 
d.  k.  Freass.  Akad.  d.  Wiss.  Berlin,  1914,  886), 
who  made  ase  of  a  totally  different  series  of 
reaotions  which  may  be  represented  thos : — 


CH,-0 


CH. 

Tri-methozy-ooiiiiiariiL 


CH,0\ 


OMg'Br 


OCH, 


O      H 
CH, 

€9 


I       Y   ^OCH, 


CH,^ 


Pelargonldin  chloride. 

In  this  way  the  stractore  of  all  the  antho- 
cyan  pigments  thas  far  investigated  has  been 
established.  It  is  interesting  to  note  that  all 
are  derivaUves  related  to  flavonols,  and  in  this 
connection  Everest  {Lc.)  has  pointed  oat  tiiat 
as  flavones  are  also  met  with  in  plants,  and 
that  they  yield  red  pigments  on  reduction,  there 
is  every  reason  to  expect  that  anthocyans 
related  to  them  may  be  oroaght  to  light  as  the 
resalt  of  farther  research. 

It  would  seem  that  these  pigments  are 
formed  in  Nature  from  flavonoi  derivatives 
first  produced  in  the  plants.  Direct  chemical 
evidence  of  this  has  been  obtained  by  Everest 
(Roy.  Soa  Pioc.  1918,  B.  90,  261).  He  has 
isolated  the  anthoovan  pigment  violanin,  a 
gluoodde  of  delphinioin, 


I 


/ 


OH 


H      ^ 

from  the  purple-black  viola  (Sutton's)  *  Black 
Knight,*  and  nas  shown  that,  unless  |;os8ypetin 
IB  present,  which  appears  unlikely,  this  pigment 
is  accompanied  in  tnose  flowers  by  a  glaooside 
of  myrioetin : 


«°Y\^^ 


/ 


OH 


KJ 


OH   A 


\)H 


,— OH 
OH 


myrioetin  being  the  flavonoi  which  would  yield 
delphinidin  by  reduction. 

Some  interestinff  substitution  derivatives  of 
the  anthoovan  series  have  been  prepared  by 
Watson  (ChenL  Soc.  Trans.  1914,  397 ;  1916, 
1477),  as  the  result  of  treating  flavone  and 
flavonoi  derivatives  with  vanous  Grignard 
reagents.  The  following  are  tjrpical  examples 
of  such  compounds : — 

i    in. 


H 


Vol.  l.—T. 


s 


338 


ANTHOCYANma 


H       ! 


0 


—OH 


or 


—OH 


In  1913,  in  oonneotion  with  their  investiga- 
tion of  the  cornflower  pigment,  Willstatter  and 
Everest  ({.c.)  showed  that  allanUiooyan  pigments 
oociuTed  in  plants  as  slnoosides  (named  by  them 
AtUhocyanifid),  and  this  generalisation  has  been 
supported  and  confirms  by  all  more  recent 
worJc  In  some  few  instances,  however,  eg.  in 
the  black  grape,  a  small  peroentsffe  of  sogar-free 
pigment  (named  aniJuxyanidin)  has  been  found 
to  accompany  the  glucoside. 

These  authors  introduced  an  important 
reaction  whereby  it  is  possible  to  determine 
whether  a  given  anthocyan  pigment  is  a  glucoside 
or  not.  When  a  solution  of  the  pigment  in 
dilute  aqueous  acid  (preferably  ca.  0*5  p.c. 
HCl)  is  shaken  with  amyl  alcohol  (free  from 
pyridine),  the  pigment,  if  a  di-glucoside  remains 
almost  quantitatively  in  the  aqueous  layer,  but  if 
it  is  a  mono-glucoside  (rhamno-glucosides  behave 
in  this  test  ver^  similarly  to  mono-gluoosides), 
then  an  appreciable  percentage  of  the  pigment 
(ca.  10  p.o.)  passes  to  the  amyl  alcohol,  out  this 
can  be  removed  by  shaking  the  alcohol  layer 
repeatedly  with  fresh  acid.  If  the  pigment  is  a 
non-elucoside  it  passes  quantitatively  into  the 
amyl  alcohol,  and  shaking  with  fresh  aqueous 
acid  does  pot  withdraw  it. 

Thb  Akthoctanidins. 

All  the  anthooyanins  hitherto  investigated 
are  derivatives  of  three  sinthocyanidins,  viz. 
Pelargonidin,  Cyanidin,  and  Ddphinidin,  or 
of  methyl  ethers  of  these  compounos. 

Pelargonidin,  which  was  first  isolated  in  the 
form  of  its  diglucoside,  pelargonin,  from  the 
Pelargonium  zonale  (Meteor),  may  be  obtained 
by  the  hydrolysis  of  that  or   any  other  of  its 


glucoekles  isokted  by  Willst&tter  and 
ooUaboratorB ;  such  compounds  oooor  in  the 
following  flowers,  either  alooa  or  mixed  with 
other  anthocyan  pigments,  viz.  puiple-ied 
summer  aster,  Callistephua  chdneims  (Nees),  syn. 
Aster  chinensis  (Linn.);  the  soariet  Salvia^ 
Salvia  eoecitiea  (linn.),  and  8.  aplendena  (Sello.) ; 
the  rose-ootonred  cornflower;  scarlet-red 
gladiolas;  and  Zinnia  elegans  (Jaoq.).  The 
colouring  matter  is  most  readily  isolated  as  the 
crystalline  chloride. 

Pelargonidln  etaloride  CisHnOaCl,  or  3 : 5 : 7- 
trihydroxy  •  2  -  p  -  hvdzoxyphenyl  -1:4- 
bemso-pyranol  anhydrochloride,  has  the  Btmcture 
represented  by : 

a 


HO 


and  crystallises  with  one  moleonle  of  waisr,  this 
being  removed  only  by  drying  in  high  vaoaum  at 
105*^  C. 

By  the  aetion  of  hvdrochlorio  acid  a  related 
product  is  formed,  tne  constitution  of  which 
IS  not  settled.  Pelaiffonidin  chloride  has  been 
observed  to  yield  three  different  crystallhw 
forms:  (L)  rod  tablets;  (ii.)  red-brown  four- 
sided  prisms ;  and  (iii.)  yellow-brown  swaUow- 
taU  twin  crystals  (c/.  WiUst&tter  and  Bolton, 
Annalen,  1915,  408,  42 ;  and  1916,  412,  133) ; 
it  is  difficultly  soluble  in  cold  dilute  acids,  more 
soluble  in  warm;  in  alcohol  it  is  very  easily 
soluble.  An  acid  solution  of  the  chloride  gives  a 
blue  colouration  on  addition  of  sodium  carbonate 
solution,  but  ferric  chloride  does  not  prodnoe 
any  colour  reaction.  Unlike  any  other  known 
pigment  of  this  series,  it  shows  two  absorption 
bands,  one  in  the  yellow-blue  portion  of  the 
spectrum,  the  other  in  the  violet,  the  latter 
being  t^e  one  not  observed  in  other  oases.  The 
compound  does  not' melt  below  350^  0. 

When  decomposed  by  heating  with  con- 
centrated caustic  potash,  or  by  fusion  with 
potash,  the  decomposition  products  are  mainly 
phloroglucinol  and  p-ozy-benzoic  acid,  but  a 
small  quantity  of  protooatechuic  acid  is  also 
formed. 

Pelargonldin  ^-bise  Oi5H,,0«,  colourless 
prisms,  not  melting  below  350^  0.,  is  formed 
when  the  chloride  is  heated  with  water  (pr^ 
ferably  by  addition  of  a  trace  of  sodium  bi- 
carbonate), the  product  extracted  with  ether, 
and  crystaUised  nom  water.  It  is  very  easily 
soluble  in  alcohol,  ether,  and  hot  water ;  acidi- 
fication of  an  aqueous  solution  with  HCl  causes 
the  deposition  en  the  chloride. 

Pelaigonidin  chloride  dyes  wool  (tin  mordant) 
purple-red,  and  tannined  cotton  bluish-red; 
it  does  not  dye  unmordanted  wool. 

Cyanidin,  first  isolated  by  WillsUtter  and 
Everest  (/.c.)  from  tiie  blue  cornflower  pigment 
(cyanin),  may  be  obtained  by  hvdroSysis  of 
tms  or  any  other  of  its  naturally  ooourring 
slucosides,  or  from  its  methyl  ether,  peonidin, 
by  demethylation.  Glucoside-pigments  derived 
from  cyanidin  have  been  isolated  from,  or 
detected  in,  the  flowers  of  blue,  and  deep  pnrple» 


ANTHOOYANINS. 


3S9 


OH 


oomfloiren,  rom  goHka,  peony,  ehr^nthemum, 
dahli*  (deep  red),  aster,  poppy,  Zmma  degans, 
gladiolu  (hybrid),  gaiOardta  6tco2or,  Aefentum 
amimmmaU^  hiUfa  funenana,  irop€Bohm  majtu, 
and  in  the  {niitf,  or  berries,  of  the  sweet  cherry, 
sloe,  oranberry,  red  eurrant,  raspberry,  and 
mountain  ask.  In  some  cases  they  are  aeoom- 
pttjed  by  deriyatiTes  of  other  anthooyanidins 
(«ec  varions  piHpers  by  II^Dst&tter  and  his 
ooOaborators). 

Gjanidlii  eUwide  GitHuOca,  3:5:7-tri- 
hy^bozT-2-fii :  p  :  dih^dzoz3^henyM  :  4-benxo- 
pyranol-anhydroohlonde : 

H      ^ 

crystaUises  readily  from  20  p.o.  Hd,  when  its 
pure  gluoosides  are  hydrolyaed  by  boiling  with 
this  reagent  for  three  minntes,  the  crystals, 
long  refbrown  needles  with  metallic  lustre, 
contain  IH^O,  which  is  very  difficult  to  remove, 
complete  drying  being  only  obtained  at  105^  C. 
in  mgh  vacuum.  The  anhydrous  salt  does  not 
melt  below  300*^  0. ;  if  dried  at  SO"*  C.  it  melts 
at  once  if  dipped  into  a  bath  at  220°  C,  but  does 
not  melt  if  put  in  at  200®  0.,  and  the  temperature 
then  gradually  raised.  It  is  lery  soluble  in 
methyl,  or  ethyl  alcohol ;  fairly  soluble  in  dilute 
solphuric  acid:  difficidtly  soluble  in  HCl. 
Neutral  alcohcJio  or  aqueous  solutions  lose 
their  colour  on  standing  owing  to  paeudo-hioe 
formation,  acids  reproduce  colour,  slowly  if  cold, 
rapidly  if  warm.  The  absorption  spectrum 
shows  one  broad  band  with  iU-delined  edges. 

Cyaoldln  colour  baso,  separates  in  crystalline 
condition  when  a  hot  concentrated  solution  of  the 
chloride  in  alcohol  is  mixed  with  twice  its 
volume  of  water  (e/.  Willstatter  and  Nolan, 
Annalen,  1916,  408,  13).  It  is  fairly  soluble 
in  alcohol  or  pyridine. 

Cyanidln  pseudo  base  Gi^HiaO?,  crystallises 
with  one  mol.  H,0  when  a  dilute  solution  of  the 
chloride  in  alcohol  is  mixed  with  twice  its  volume 
of  water,  warmed  gently,  then,  after  it  has 
become  colourless,  evaporated  in  txicuo,  extracted 
with  ether,  and  the  product  crystalliserl  from 
water.  Readily  solonle  in  water,  alcohol, 
acetone,  or  glacial  acetic  acid,  it  is  insoluble  in 
benzol ;  wiUi  soda  it  gives  a  yellow  colouration, 
with  HGl  cyanidin  chloride  is  formed  and 
crystallises  out.  When  decomposed  by  means 
of  fused  alkali  protocatechuio  acid  and  phloro- 
glucinol  are  produced. 

Cyanidin  chlorides  dyes  wool  (tin  mordant) 
blue- violet,  cotton  (tannined)  violet,  and  unmor- 
danted  wool  fine  rose  (Willstatter  and  Mallison). 
,  Delphinldin,  first  obtained  by  Willstatter 
and  Mieg  (Annalen,  1915,  408,  61)  from  the 
pigment  of  purple  wild  delphinium  (delphinin), 
may  also  be  obtained  by  hydrolysis  of  violairin, 
the  only  other  glncoside  of  delphinidin  itself 
that  has  as  yet  been  isolated,  or  oy  demethyla- 
tion  of  its  mono-  or  di-methyl  ethers,  several  of 
which  occur,  as  glucosides,  in  a  variety  of 
flowers  and  fruits. 


IMphlllMlii  oMorido  CuHuOtGI,  8:6:7- 
trihydroxy-2-iii :  m  :  p :  trihTdrozyphenyM  :  4* 
benzopyranol-anhydroohloride : 

CI 


HO 


\/\^ 


prenared  by  boiling  the  above-named  glucosides 
witn  20  p.0.  HCl  ror  two  minutes,  raraiy  sepa- 
rates pure  from  the  hydrolysis  as  it  Is  affected 
by  concentrated  hot  HCl.  Four  distinct  crystal- 
line hydrates  have  been  described  by  Willstatter 
and  WeU  (Annalen,  1916,  412,  178),  vis.  with 
1H,0,  1}H,0,  2H,0,  and  4H,0.  W.  and  W.'s 
'first  hydrate'  (2H,0)  separates  from  cold, 
aqueous  aiooholio  hydrochloric  acid  solutions 
(prepared  by  addition  of  7-20  p.c.  HCl  to  an 
alconolic  solution  of  the  colour)  when  the  alcohol 
is  allowed  to  evaporate  slowly ;  it  forms 
aggregates  of  prismatic  tablets ;  their  *  second 
hydrate*  (1H|0)  separates  from  cold,  3-^  p.c. 
hydrochloric  asid  as  thin,  sharply-cut,  deep- 
violet,  rhombic  tablets ;  their  *  uurd  hydrate ' 
(4H|0)  is  deposited  from  5  p.c.  hydrochloric 
acid  in  the  form  of  fine  red-brown  prisms  and 
needles;  their  *  fourth  hydrate'^  (UH^O) 
separates  from  hydrochloric  acid  containing 
more  than  20  p.c.  HCl,  and  is  readily  prepared 
by  adding  concentrated  HCl  to  a  solution  of  the 
colour  in  water,  or  dilute  HCl,  when  an  amor- 
phous precipitate  is  first  produced,  but  this 
slowly  crystallises.  All  the  above  hydrates 
lose  their  water  of  crystallisation  in  a  vacuum 
desiccator  at  room  temperature.  Of  these 
hydrates  the  third  and  fourth  appear  most 
readily  obtainable. 

The  chloride  is  easily  soluble  in  methyl,  or 
ethyl  alcohol,  and  in  water — ^the  aqueous  solution 
soon  deposits  violet  flakes  of  the  colour  base — 
it  is  difficultly  soluble  in  dilute  sulphuric  acid ; 
ether  extracts  a  portion  of  the  colour  from  an 
aqueous  solution,  but  shaking  the  ether  extract 
with  aqueous  acid  completely  removes  the 
colour.  Addition  of  soda  to  an  acid  solution 
yields  a  fine  blue  colour ;  ferric  chloride  added 
to  an  alcoholic  solution  gives  a  pure  blue,  to 
an  aqueous  solution  a  violet  colouration.  When 
the  chloride  was  treated  with  caustic  potash 
(75  p.c.)  at  250**  C,  Willstatter  and  Mieg  ob- 
tained phloro^lucinol,  pyrogallol,  and  a  small 
amount  of  galhc  acid.  Tne  absorption  spectrum 
consists  01  one  band  (yellow-green),  which  is 
fairly  well  defined. 

Delphini4in^  sulphate,  long  prisms,  from  hot 
dilute  sulphuric  acid.  lod&e,  brown  prisms, 
or  leaflets,  obtained  by  boiling  the  chloride  with 
concentrated  hydrioaic  acid  and  phenol.  Pi- 
crate,  fine  red-brown  needles  and  prisms,  diffi- 
cultly soluble  in  water.  Colour  hase,  amorphous 
violet  precipitation  deposited  from  neutral 
aqueous  solutions  of  the  chloride  on  standing. 
Pseudo  ha.se  Ci6H,,0g,  obtained  by  warming  a 
dilute  solution  of  the  chloride  with  a  trace  of 
primary  sodium  phosphate,  extracting  with 
ether  and  recrystalusing  the  product  from  water 
or  ether;    colourless  prisms,  no  melting-point; 


840 


ANTHOCYANINS, 


easily  aolable  in  alcohol,  acetone,  ethyl  aoetate, 
or  ff(acial  aoetio  aoid,  leas  solnUe  in  ether, 
insolnble  in  benzol ;  aqueous  soda  dissolyes  it 
with  a  yellow  colour,  aqneons  hydrochloric  add 
ooQTerta  it  into  the  chloride. 

Delphinidln  ohloride  dyes  mordanted  wool 
(tin)  blue,  with  Tiolet  tuige,  tannined  cotton 
blne-yiolet,  and  unmordanted  wool  violet. 

MbTHTL  EtHSR   OV   OYANIDIli. 

Peonldln,  obtained  by  Willstatter  and  Nolan 
(Annalen,  1915,  408,  166)  from  the  pigment  of 
the  deep  Tiolet-xed  peony,  has  been  proved  by 
them  to  be  a  mono-methvl  ether  of  oyanidin. 

Peonldin  ehloride  Ct  tHi,0«Gl  forms  a  crystal- 
line hydrate  with  IH^O,  long  red-brown  needles, 
fairly  soluble  in  oold  water,  veiT  soluble  in  hot; 
yei^  soluble  in  alcohol;  venr difficultly  soluble  in 
cold,  easily  soluble  in  hot  1  p.c.  HO,  reorystal- 
Using  weU  from  this  medium.  With  boiling 
hydnodic  aeid  it  yields  oyanidin  iodide;  an 
acid  solution  yidds  a  blue  colour  on  addition  of 
soda;  ferric  chloride  gives  no  characteristic 
colour  reaction.  From  the  ferric  chloride  test, 
together  with  the  alkaline  decomposition,  wluch 
yielded  evidence  of  a  methyl  ether  of  the 
phenolic  add,  but  no  methyl  ether  of  jphloro- 
gludnol,  and  further,  as  the  result  oi  Zeisel 
estimations,  WHlst&tter  and  Nolan  suggest  the 
formulae : 

9  ^OMe 


HO 


Vk\)h 


I 

H 

a 


OH 


or 


H 

as  probable  for  peonidin  chloride. 

Ptonldin  ni^hlte,  brown-red  needles,  from 
7  p.a  aqueous  sulphuric  add. 

MSTHTL    EtHSBS  OF  BXLFHINIDIN. 

(a)  Mono-meihyl'Sthers. 

Ampelopsldin,  isolated  as  the  eJdoridtf 
CicHitO^a,  bv  WillBt&tter  and  Zollinger  (Anna- 
len,  1916,  412,  216)  from  the  pigment  of  the 
ampelopsis  {see  below),  crystallises  in  prisms 
containmg  water  of  crystallisation,  the  amount 
of  which  has  not  yet  been  definitely  settled, 
and  probably  has  the  structure : 


a 


OH 

OMe 


\ 


OH 


OH 


pigments  mtftiiUin  or  aUhdn  (see  below)  by 
Willst&tter  and  Zollinger  (AnnaJen,  1916,  408f 
83;  and  1916,  412,  206)  in  the  form  of  the 
crystalline  ehloride  OicHi^OrCl,  clusten  of  deep 
brown  prisms,  or  led-brown  prismatio  tablets, 
containms  1)H,0.  Upon  evidence  obtained 
from  alkaline  decomposition,  and  oonsideratioa 
of  the  ferric  chloride  reaction,  W.  and  Z.  con- 
sider that  the  chloride  has  one  of  the  following 
structures,  viz. : 

a 

HO^     -     -'»  ^^ 


Its  investigation  is  not  yet  complete. 

MyrtilUdln    has    been    obtained    from    the 


Pitiinidlil,  prepared  by  Willstatter  and 
Burdick  (Annalen,  1916,  412,  217)  from  the 
pigment  of  the  odltivateMi  petunia  («ee  below), 
forms  a  crystalline  chloride  C]tHi,07Cl,  yellow- 
brown  prisms,  or  rhombic  leaflets,  containing 
2H,0;  it  is  dosely  related  to,  but  somewhat 
different  from,  myrtillidin,  and  W.  and  B.  con- 
sider that  petunidin  is  represented  by  one,  and 
myrtillidin  by  the  other  of  the  two  structural 
formula  set  out  above  under  myrtillidin,  but 
at  present  a  decision  between  them  is  not 
possible. 

Anthotyanidin  from  VUis  Riparia  PiffmenL 
This  product  is  probably  one  of  the  other 
possible  mono-methyl  ethers  of  ddphinidin,  but 
the  work  on  it  as  yet  is  veiy  incomplete. 

(b)  Di-methifl  Bikers. 
MalTidliL  This  compound  has  been  isolated 
from  the  pigment  of  the  wild  mallow  (see  below) 
bv  WiUstUter  and  Mieg  (Annalen,  1916,  408, 
122),  who  obtained  it  in  the  form  of  its  crystal- 
line chloride  OiYHigOfCa,  deep-brown  needles 
or  prisms,  often  in  rosettes,  containing  2H,0, 
of  which  the  last  1H,0  can  only  be  lemoved  at 
106®  C,  in  high  vaoaum.  It  does  not  melt 
below  SOO""  C.  Easily  soluble  in  methyl  or 
ethyl  alcohol,  but  the  solution  in  methyl  alcohol 
soon  deposits  a  cr3r8ta]line  precipitate;  fairiy 
soluble  in  amyl  alcohol,  it  is  cufficultly  soluble  in 
dilute  sulphuric  acid.  It  gives  no  ferric  chloride 
reaction,  from  which,  and  the  fact  that  they 
obtained  evidence  from  alkaline  decompodtion, 
that  one  MeO  group  was  in  each  of  the  benzene 
nudd,  W.  and  M.  have  put  forward  the 
structural  formuL^ : 


a 


OH 

OMe 
\0H 


ANTHOOYANINS. 


341 


HO— 


or 


for  this  compound. 

Picrak,  rod-brown  needles,  difficultly  soluble 
in  water. 

Oenldln  bas  been  prepared  by  WillBt&tter 
and  Zollinger  (Annalen,  1915,  408,  83;  and 
1916,  412,  195)  from  the  pigment  of  the  black 

frape,  or  red  wine.  It  appears  to  exist  in 
lack  grapes,  with  the  gluooude  oenin. 
Oenldm  ehloride  CnHitOvCl  crystallises  in 
deep  brown  prisms  or  needles,  with  bronze 
reflex,  contaming  l^HsO,  of  which  the  last 
half  molecule  is  not  removed  until  heated  to 
135®  C.  in  high  vacuum.  It  is  readily  soluble 
in  water,  in  methyl  or  ethyl  alcohol,  in  dilute 
HCl  or  dilute  sulphuric  acid ;  an  acid  solution 
becomes  violet  on  addition  of  soda,  but  blue 
with  caustic  soda.  From  the  products  of 
alkaline  decomposition  (which  showed  that  no 
MeO  group  was  present  in  the  portion  of  the 
molecule  which  yielded  phlorogluoinol,  but  at 
least  one  was  in  the  other  phenyl  group),  and 
the  absence  of  a  ferric  chloride  reaction,  Will- 
st&tter  and  Zollinger  have  proposed  the  following 
formula  for  this  compoimd,  viz. : 


CI 


wv^o 


u 


v/ 


Cv 


.OMe 
— OMe 
\0H 


■A  A 


OH 


or 


Hi      i 


/ 


OH 


X"\_OMe 
\0H 


PicrcUe,  fine  deep  red  prisms,  very  difficultly 
soluble  in  water. 

All  the  above-mentioned  mono-  or  di-methyl 
ethers  of  delplunidin  yield  delphinidin  iodide 
when  boiled  with  concentrated  hydriodic  acid. 

The  Gluoosidbs  (Anthootanins). 

The  glucoaide  members  of  this  group  are  the 
pigments  producing  the  reds,  purpfes,  and  blues 
wmeh  form  so  noticeable  a  pait  of  the  colourings 
of -flowers,  fruit,  and  autumn  leaves.  In  many 
instances  one  pigment  may  produce  all  these 
shades,  the  colour  being  dependent  on  the  con- 
dition of  the  cell  sap ;  wus  cyanin*  as  its  potas- 
sium salt,  is  the  uue  of  the  blue  cornflower; 
aa  the  oolonr  base,  it  is  the  purple  of  the  deep 
pmpla  kindfl  of  tiie  same  plant,  whereas  the 
same  pigment  in  combination  with  plant  adds 
gives  Uie  red  colour  to  Baaa  gaUka, 


Yellow  sap  pigments,  flavone  derivatives, 
beinff  but  very  famtly  coloured  unless  prMent 
as  flSksli  salts,  rarely  play  any  great  part  in 
the  colouration  of  flowers,  except  in  the  produc- 
tion of  pale  yellows,  as  in  the  primrose,  or 
t(^ether  with  anthocyanins,  where  these  are 
not  strong,  of  pale  peach-colour  effects ;  on  the 
other  hand,  tne  strongly  yellow,  or  orange, 
oarotinoids  produce^beyona  the  colourations 
for  which  they  are  solely  responsible — orange 
and  brown  shades  when  present  together  with 
anthoojrans. 

Owing  to  the  varyii^  sap  conditions  which 
occur,  and  their  effect  on  tne  pigments,  it  is 
not  easy,  and  is  often  impossible,  to  obtain,  by 
means  of  mere  observation,  any  accurate  estima- 
tion of  the  quantity  of  an  anthocyan  pigment 
S resent  in  a  flower;  moreover  the  shades  pro- 
uced  by  different  anthocyanins  often  resemble 
one  another  so  closely  as  to  make  discrimination 
between  them  impossible  (e/.  Willstatter  and 
Mallison  Annalen,  408,  147). 

Methods  of  IsokUum, 

Willst&tter  and  MalllMm  (le.)  summarise 
the  various  methods  used  for  the  isolation  of 
antho^anin  pigments  thus  :-— 

L  Precipitation  and  crystallisation  of  the 
chloride,  e.g,  pelargonin. 

II.  Special  purification  of  the  pigment 
followed  oy  crystallisation  of  the  chloride,  e.g, 

\a)  Cyanin  (i).  from  blue  cornflower,  by 
punfication  of  the  alkali  salt  by  precipitation 
with  alcohol  from  aqueous  solution,  followed  b^ 
conversion  to  the  cnloride  and  fractional  pun- 
fication from  alcohol  by  ether ; 

(ii.)  from  rose,  or  peony,  by  lon^  standing 
with  a  mixture  of  glacial  acetic  acid,  methyl 
alcohol,  and  HCl,  whereby  impurities  are 
hydrolysed  or  acetylated. 

(&)  MyrtiUin,  by  repeated  purification  from 
aqueous  solution  by  HCl. 

(c)  Ddphinin  (i.)  by  purification  of  violet 
cobur  base  from  dilute  alcohol,  soluble  by  addi- 
tion of  concentrated  alcohol ; 

(ii.)  by  gently  warming  with  HCl,  whereby 
impurities  are  hydrolysed,  but  not  the  delphinin. 

ni.  Precipitation  of  the  pigment  as  crystal- 
line picrate,  followed  by  conversion  of  the  pure 
picrate  to  chloride,  e.g.  Oenin,  myrtiUin,  idaein. 

1.  Derivatives  oj  Pdargonidin. 

Pelargonin,  a  diglucoside  of  pelargonidin, 
the  pigment  of  the  scarlet  pdargonium  zonale, 
was  so  nuned  by  WiUstatter  and  Bolton  (Anna- 
len, 1915, 408, 42),  to  whom  we  owe  our  chemical 
knowledge  of  this  pigment.  Cf.  earlier  workers, 
Griffiths  (2.C.),  Molisch  (I.e.),  and  Grafe  (Z.c.). 
WiUstatter  and  Bolton  have  also  shown  that 
this  colouring  matter  occurs  in  the  pink  corn- 
flower, and  the  cactus  dahlia  {ibid,  p.  149). 

Pelargonin'  chtoride  C„H,iOitCl  crvstallises 
in  long  red  needles,  containing  4H,(),  all  of 
which  is  lost  in  vacuum  desiccator  at  room 
temperature.  When  anhydrous  it  softens  at 
175"^  C,  mslts  at  180<*  C.  (decomposed).  Not 
very  soluble  in  water,  methyl,  or  ethyl  alcohol, 
its  alooholio  solutions  show  charaotenstio 
greeniah-yellow  fluorescence.  It  is  optically 
active.  W.  and  B.  give  [«],>= -291*,  la],u« 
—  180^ ;  the  salt  shows  aof  absorption  spectrum 
consisting  of  one  broad  band. 


342 


ANTHOCYANINS. 


Baaie  chloride 

'(C„H,iOi5Cl),(C„H,oOx,)12H,0, 

deep  violet  miorosoopio  needles,  obtained  by 
boiling  the  normal  ohioiide  with  96  p.o.  alcohol 
for  a  few  minutee.    Acetate 

(C,7H„0i,),(C,;H„0i,-C,H,0j), 

fine  red  needles  from  a  solution  of  the  base  («ee 
below)  in  warm  glacial  acetic  acid.  Pdargonin 
hose  Ca^HgoOiB,  amorphous,  difficultly  soluble 
in  water  or  alcohol,  oDtainad  by  the  action  of 
a  small  quantity  of  water  on  the  normal  chloride. 

SalviaDin  (Willstatter  and  Bolton,  Annalen, 
1916,  412,  113),  as  yet  only  obtained  crystalline 
as  picrate,  is  the  pigment  of  the  scarlet  Salvia 
splendens,  in  whion  it  occurs  to  the  extent  of 
ca.  6  p.o.  The  chloride  (not  crystalline)  when 
completely  hydrolysed,  yields  pelargonidin 
chloride  (co.  36  p.c.),  glucose  {ca,  30  p.c),  and 
malonio  acid  {ca.  25  p.c.).  It  behaves  abnor- 
mally in  distribution  between  amyl  alcohol  and 
aqueous  acid,  and  it  appears  possible  that 
the  glucose  is  present  in  a  dehydrated  form 
C«HioOt.  Garetul  hydrolysis  with  HCl  appears 
to  remove  the  malomc  acid,  yielding  a  new  pig- 
ment Salvin  chloride,  probably  Ga7H,70itCl  (a 
digluooside  of  pelargomdin— 2M,0),  which  shows 
the  same  abnormal  distribution  as  the  previous 
compound;  this  was  obtained  in  a  crystalline 
conoition  by  W.  and  B.  Further  sentle  hydro- 
lysis then  yields  a  true  di^lucoside  ofpelaigonidin 
which  was  named  Salvintn  chloride  C^yB.^iOi  sCl ; 
this  bodv  shows  normal  distribution  for  a 
diglucoside  anthocyanin,  whilst  by  further 
careful  hydrolvsis  it  yields  a  mono-slucoside  of 
pelaigonin  and  glucose  (1  mol.),  wnilst  finally 
the  mon^lucoside  vields  pelargonidin  and 
glucose.  W.  and  B.  nave  not  completed  their 
investigation  of  these  pigments,  and  the  names 
they  have  used  are  stated  to  be  tentative. 

CalUstaphilly  a  mono-slucoside  of  pelargonin, 
is '  present  together  witn  asterin  (a  cyanidin 
gluooside)  in  purple-red  asters  {Calltstephus 
chinensis  (Nees),  83m.  Aster  chinensis  (Linn.),  from 
which  it  was  isolated  by  Willstatter  and  Burdick 
(Annalen,  1916,  412,  149).  It  was  separated 
from  asterin  by  fractional  precipitation  from 
alcohol  by  ether,  and  reorystaUised  from  aqueous 
alcoholic  hydrochloric  acid.    Chloride 

CtiHjiOioCl, 
fine  orange-red  needles  containing  2-2^  H,0; 
easilv  soluble  in  water,  alcohol,  or  dilute  acids 
(HCl,  HtS04).  Acid  solutions  become  xed- 
violet  with  alkalis ;  it  gives  no  ferric  chloride 
reaction;  unlike  pelargonin  it  does  not  show 
fluorescence  in  alcoholic  solution. 

Pelargonenin,  a  mono-glucoside  of  pelargo- 
nidin, has  been  prepared  by  Willstatter  and 
Bolton  (Annalen,  1910,  412,  133)  by  partial 
hydrolysis  of  pelargonin  with  cold  concentrated 
aCl,  any  pelaigonidin  produced  being  removed 
by  means  of  amyl  alcohol,  and  the  chloride 
crystallised  from  warm  2  p.c.  HCl.  Chloride 
OsiH,iOioCl,  scarlet-red  needles,  probably  con- 
taining 2^  moLs.  water,  sparingly  soluble  in  water, 
very  difficultly  soluble  in  dilute  HCl ;  its 
alcoholic  solutions  show  strong  fluorescence. 

2.  Derivatives  of  Cyanidin. 

Cyanln,  the  pigment  of  blue  or  purple  com- 
floweciy  also  ocours  in  Boea  ifalUca,  and  deep  red 


dahlia  flowers ;   it  is  a  diglucoside  of  ovanidin. 
Willstatter  and  Everest  (Annalen,   1913,  401, 
189)  first  obtained  it  in  a  pure  condition,  as  the 
crystalline  chloride,  from  the  blue  ooxxiflovrer; 
it  is,  however,  more  readily  prepared  from  Boea 
ffallica  (W.  and  Nohm,  Annalen,  1916,  408,  1), 
or  the  deep  red  dahlia  ( W.  and  MalHson,  Annalen, 
1916,   408,    147).     The   chloride  Ca7H,iOi«Cl, 
red- brown  rhombic  leaflets  containing  21  mds. 
of  water  can  only  be  completely  dried  at  106^  0. 
in  high  vacuum.    Air-dned  it  is  very  difficultiy 
sqluUe  in  water,  acetone,  or  chloroform,  diffi- 
cultly soluble  in  cold  alcohol  or  dilute  HCl, 
insoluble  in  benzol.    In  7  p.c.  sulphuric  acid  it 
is  fairlv  soluble,  but  the  sulphate  separates  out 
from  the  solution.     Soda  added  to  an  aoid  solu- 
tion gives  a  pure  blue ;   ferric  chloride  gives  a 
fine  blue  in  alcohol,  violet  in  water.    It  shows 
a  single  absorption  band  covering  the  gnen  and 
blue;    it  is  optically  active.     Willstatter  and 
Nolan  give,  for  white  light,  ra]=-268*  (±10*»). 
Picrate,   rc^  needles,   very  solublB  in  water. 
Cyanin  potassium  salt,  the  blue  pi^ent  of  the 
cornflower,  was  obtained  orystallme,  but  not 
free  from  Nad,  by  Willstatter  and  Everest, 
after  purification  by  dialysis.    It  is  very  soluble 
in  water,  insoluble  in  alcohol ;  its  blue  aqueous 
solutions  become   colourless  on  standing  owing 
to  formation  of  psevdO'  base,  whereas  in  20  p.c. 
NaCl  solution  the  colour  is  stable  for  months. 

Mekocyanln,  isolated  by  Willstatter  and 
Weil  (Annalen,  1916,  412,  231),  is  one  of  the 
pigments  of  the  poppy  {Papaver  rhcBos  (Linn.)), 
and  a  diglucoside  of  cyanidin.  Its  isolation  is 
difficult,  and  involves  a  separation  from  a 
second  pigment  which  has  not  yet  been  iovesti- 
^ated.  Tne  chloride  CarHsiOnCl,  crvstallises 
in  needles  containing  3H,0,  2  mols.  being 
readily  removed,  the  third  only  at  106^  C.  in 
high  vacuum.  Very  easily  soluble  in  water, 
dilute  HCl,  fairly  soluble  in  methyl,  difficultly 
soluble  in  ethyl  alcohol,  insoluble  in  acetone,  but 
soluble  in  a  mixture  of  acetone  and  water ;  its 
reactions  closely  resemble  those  of  cyanin 
chloride.  Ferrocyanide,  fine  red-brown  needles, 
prepared  bv  adding  potassium  ferrocyanide  to  a 
solution  of  the  chloride  in  very  dilute  iK/l; 
fairlv  soluble  in  water,  sparingly  soluble  in 
alconol. 

Mekocyanin  chloride,  when  carefully  hydro- 
lysed, first  yields  a  mono-glucoside  (identical 
with  Chrysanthemin)  and  1  mol.  glucose,  then 
by  further  hydrolysis  oyanidin  and  a  further 
molecule  of  glucose. 

KoneyaSn,  a  rhamno-gluooside  of  cyanidin, 
is  the  pigment  of  the  sweet  cherrv  (Prunus  avium 
(Linn.)),  and  has  been  isolated  by  Willstatter 
and  Zollinger  (Annalen,  1916, 412, 164)  from  the 
skins  of  that  fruit ;  the  purification  is  tedious, 
and  not  final  in  form.  The  chloride  C^iSL%\Oifi\ 
occurs  in  two  forms,  fine  needles  containing 
4H2O,  and  short  brown-yellow  prisms  contain- 
ing 3H,0.  The  salt  is  easily  soluble  in  methyl 
alcohol,  fairly  soluble  in  ethyl  alcohol,  difficultly 
soluble  001-0*1  p.c.  HCl,  but  easfly  soluble 
1  p.o.  HCl,  then  less  soluble  as  the  concentration 
of  HCl  increases. 

Prunieyanin,  isolated  by  Willstatter  and  Zol- 
linger (Z.c.)  from  the  skuis  of  the  sloe  (blackthorn, 
Prunus  spinosa  (Linn.))  is  a  rhamno-gluooside 
of  cyanioin,  closely  resembling  mekocyanin ; 
its  investigation  is  not  yet  complete.    CitoridCt 


ANTHOOYANINS. 


34$ 


not  obtained  crystalline,  bat  as  small  spherical 
particles;  yields,  on  hydrolysis,  oyanidin  chloride, 
rhamnose,  and  a  hexose  (not  yet  identified),  in 
approximately  molecular  proportions. 

Asterin,  one  of  the  pigments  of  the  porple- 
red  aster  (e/.  GalUstephin),  has  been  isolated  by 
WiUstatter  and  Buidick  (l.c),  it  is  a  mono- 
glucoside  of  cyanidin.  The  ckUnide  C,iH,iOi iCl, 
red-brown  prisms,  containing  HH,0,  closely 
resembles  ooj^santhemin  chloride  in  its  reac- 
tions, but  differs  greatly  from  it  in  solubilities 
in  dilate  aoids. 

Chrysanthemin,  isolated  by  Willst&tter  and 
Bolton  (Annalen,  1916,  412,  136),  a  mono- 
glucoside  of  cyanidin,  is  the  pigment  of  the  deep 
red  chrysantnemum  {ChrysarUhemum  indicum 
riiinn.)).  The  chloride  CaiH,iOiia,  red-violet 
leaflets  containing  l^HjO,  resembles  Idsein 
chloride  in  many  respects.  Picrate,  thin  red 
prisms,  difficultly  soluble  in  water,  sinters  at 
106''  a,  melts  at  IdS*"  G.  (decomp.). 

IdSBln,  the  pigment  of  the  cranberry  {Vacci- 
niwn  viiis  idcsa  (Linn.)),  has  been  isolated  by 
Willst&tter  and  Mallison  (Annalen,  1910,  408, 
10} ;  it  is  a  mono-galactoside  of  cyanidin.  The 
cMaride  OtiH.iOnCl,  brown-red  prisms  con- 
taining 2{H.O,  melts  at  210""  CT  (frothing). 
Easily  soluble  in  water  or  alcohol,  almost 
Insoluble  in  dilute  HCl ;  ferric  chloride  gives  a 
blue  colour  ia  alcohol,  a  violet  in  water.  It  is 
optically  active,  W.  and  MT  give :  [o]o=— 219° 

(:i:10^).  PicraJUf  red  needles,  more  soluble  in 
hot  than  in  cold  water.  Svlphaie,  brown  rhombic 
crystals  from  7  p.o.  sulphuric  add. 

Peonin,  a  diglucoside  of  peonidin,  the  pig- 
ment of  the  deep  violet-red  peony,  has  been 
isolated  by  WiUst&tter  and  K^olan  (Annalen, 
1910,  408,  136).  The  chloride  OtsH„Oi,Cl, 
red- brown  needles  containing  6H,0,  m.p. 
leS""  G. ;  for  complete  drying  100"*  G.  in  hi^ 
▼aouum  ia  necessary.  Very  easily  soluble  m 
water,  easily  soluble  in  alcohol,  msoluble  in 
acetone ;  it  resembles  oyanin  in  many  reactions, 
bnt  ferric  chloride  gives  no  characteristic 
reaction.  It  is  optically  active.  W.  and  N.  give, 
for  white  light,  [a]=-191*  (iO**).  Picrate, 
red-brown  needles,  from  water. 

3.  Derivativu  of  Ddphinidin. 

Delphinin,  the  pigment  of  the  purple  wild 
delphinium  {Ddphintum  coneolida  (tdnn.)),  has 
been  isolated  by  WiUstatter  and  Mieg  (Annalen, 
1910,  408,  61),  and  is  a  complex  derivative  of 
delphinidin.  Unlike  all  other  Known  anthodyan 
pigments,  it  does  not  appear  to  form  a  pseudo- 
OMe  when  its  neutral  aqueous  solution  is  allowed 
to  stand,  or  is  warmed.  Although  the  free 
colour  base  can  be  isolated  by  fractional  pre- 
cipitation with  alcohol,  the  compound  is  best 
isolated  as  the  chloride  G4tH,90,iCl,  which 
appears  to  crystaUise  with  12  mols.  of  water, 
of  which,  however,  only  10  can  be  removed 
even  by  drying  in  I^gh  vacuum  at  130*^  G.  It 
forms  aeep-rea  prismatic  tablets  or  prisms,  and 
dried  as  above  sinters  at  10O''-16O''  G.,  thtn 
melts  at  200^-203^  G.  (decomp.  and  swelling). 
Easily  soluble  in  methyl  alcohol,  difficulty 
soluble  in  eth^l  alcohol,  in  dilute  HGl  (over 
0*0  p.o.),  or  m  dilute  sulphuric  acid;  water 
rapidly  produces  the  colour  base ;  ferric  chloride 
gives  a  olne  colouration  in  aqueous  or  alcoholic 
solution :  sodium  carbonate,  to  an  acid  solution. 


gives  a  fine  blue.  The  salt  is  optically  active, 
W.  and  M.  give  [a]o=  - 1364°  (±100°) ;  [a],i4= 
-2273°  (±160°);  its  absorption  spectrum 
consists  of  one  broad  band.  When  hyorolysed 
it  yields  delphinidin  chloride  (1  moL),  glucose 
(2  moLs.),  and  p-oxy-benzoio  acid  (2  mols.). 
Colour  hose,  produced  by  the  action  of  water 
on  the  chloride,  and  recrystallised  from  dilute 
alcohol  by  slow  increase  in  the  concentration  of 
the  alcohol,  forms  rosettes  of  violet  needles. 
Picrate,  red-brown  fiocculent  precipitate,  very 
difficultly  soluble  in  water. 

Violanin,  isolated  by  WiUstatter  and  WeU 
(Annalen,  1916,  412,  178)  from  the  blue-bhick 
pansy,  and  bv  Everest  (Roy.  Soo.  Proo.  1918, 
B,  90,  251)  from  the  purple-black  viola,  is  a 
rhamno-glucoside  of  delphinidin.  The  chloride, 
probably  G^jHsiOnGl,  forms  deep  red  hexagonal 
or  tetrahedral  plates  or  tablets  containing  about 
16  p. c.  of  water.  Its  solubiUty  in  aqueous  HCl 
decreases  up  to  ca.  12  p.c.  HCl,  but  increases 
again  after  ca.  20  p.o.  HCl  is  reached ;  it  is  almost 
insoluble  in  dUute  sulphuric  acid ;  with  soda  an 
acid  solution  gives  a  blue  colour ;  ferric  chloride 
gives  pure  blue  in  alcohol,  or  in  water.  Hydro- 
lysis yields  delphinidin  chloride,  glucose,  and 
rhamnose  in  approximately  molecular  propor- 
tions. PicrcUe,  cnerry-red  needles,  fairly  soluble 
in  water. 

Ampelopsin,  the  pigment  of  the  berries  of 
Ampelopsis  quinqiufolia  (Michx.),  Vitis  hede- 
racea  (Ehrh.),  has  been  isolated  by  WiUstatter 
and  Zollinger  (I.e.) ;  it  is  a  mono-glucoside  of 
ampelopsioin.  The  chloride  GijHjjOitCl  crys- 
tallises in  prisms  containing  4H.0;  eaaly 
soluble  in  methyl  or  ethyl  ucohol;  sodium 
carbonate  gives  violet,  caustic  soda  a  blue 
colouration  when  added  to  an  acid  solution; 
ferric  chloride  only  produces  a  weak  reaction. 

Hyrtlllin,  the  pigment  of  the  bUberry 
[Vcuxinium  myrtillue  (Linn.)),  has  received  at- 
tention from  earlier  workers — cf.  Andree  (Arch. 
Pharm.  1879,  13,  90),  Heise  (I.e.),  and  others-- 
but  its  isolation  is  due  to  WiUstatter  and  Zollin- 
ger (Annalen,  1915,  408,  83  ;  and  1916, 412, 200). 
It  is  a  mono-glucoside  of  myrtiUidin.  The 
chloride  GtaHjsOnCl,  forms  red  brown  tablets 
containing  IH^O,  which  is  only  k  st  completely 
in  high  vacuum  at  105°  G.  It  is  very  soluble 
in  water,  or  methyl  alcohol,  but  less  soluble  in 
ethyl  alcohol.  Ferric  chloride  gives  a  blue  in 
alcohol,  violet  in  water;  sodium  carbonate 
produces  blue-violet,  caustic  soda  blue  when 
added  to  an  acid  solution.  Its  absorption 
spectrum  shows  one  band  with  Ul-defined  cilges. 
PicrcUe,  red  needles,  difficultly  soluble  in  water. 

Althein,  the  pigment  of  the  black  hoUyhock 
{Althaea  rosea  (Cav.)),  has  been  isolatea  and 
described  by  WiUstatter  and  Martin  (Annalen, 
1915,  408,  100;  cf.  Polyt.  Zentralblt.  1860, 
1540 ;  Qla^,  I.e. ;  and  Grue,  I.e.).  The  chloride 
C,2H„0itCl  which  crystallises    in    brown-red 

Srisms  containing  4H2O,  is  easUy  soluble  in  water, 
Uute  HCl,  dUute  sulphuric  acid,  or  in  methyl 
or  ethyl  alcohol,  but  almost  insoluble  in  glacial 
acetic  acid ;  ferric  chloride  gives  a  violet-blue 
colour  in  alcohol,  and  violet. in  water;  sodium 
carbonate  produces  a  blue  colour  when  added 
to  an  acid  solution.  It  is  opticaUy  active.  W. 
and    M.    give    [a],„=-600°;    [ao]=~040°; 

[a]e»a=-~291°.     The  ptcrate  is  crystalline  and 
difficultly  soluble. 


344 


ANTHOCYANINS. 


Petnnliiy  the  oolouring  matter  of  the  purple- 
blue  petunia  *  KarlBruher  Rathaus,*  was  isolated 
bv  Willstatter  and  Burdick  (Annalen,  1016,  412, 
217);  it  is  a  diffluooside  of  petunidin.  The 
ehioride  Omj^tfii^  crystalliaeB  in  prisms  con- 
taining 28^0,  which  sinter  at  166°  (3.  and  melt 
at  178*'  G.  It  is  difficultly  soluble  in  dilute 
HGl,  fairly  soluble  in  dilute  sulphuric  acid, 
easily  soluble  in  methyl,  but  less  so  in  ethyl 
alcohol ;  ferric  chloride  gives  a  poor  blue  colour 
in  alcohol,  or  in  water ;  sodium  carbonate  turns 
an  acid  solution  blue. 

The  anthocyanin  from  the  skins  of  the  berries 
of  VUis  fipana  is  a  mono-sluooside  of  a  delphi- 
nidin  mono-methyl  ether,  But,  though  obtained 
in  a  finely  crystalline  condition  by  Willst&tter 
and  Zollinger  (2.c.),  it  has  not  yet  been  com- 
pletely investigated. 

Mal¥ln,  isolated  by  Willst&tter  and  Mieg 
(Annalen,  1916, 408, 122)  from  the  flowers  of  the 
wild  mallow  (JfaA»  sUveslris  (LSnn,)),JB  a  djglu- 
coside  of  malvidin.  The  cJUonde  OtfHttOnCl 
forms  long  red  prisms,  or  bundles  of  needles, 
containing  8H,0,  all  of  which  is  lost  at  room 
lemperature  in  vacuum  desiccator.  Difficnltlv 
soluole  in  dilute  Hd,  or  dilute  sulphuric  acia. 
it  is  easily  soluble  in  methyl  alcohol,  but  less  so 
in  ethyl  alcohol.  It  gives  no  ferric  chloride 
reaction;  sodium  carbonate  turns  an  add 
solution  blue.  Picrate^  red  needles,  fairly  soluble 
in  water. 

Oenln,  the  pigment  of  black  grapes,  and  of 
red  wine,  has  been  the  subject  of  many  investiga- 
tions from  the  time  of  Berzelius  (1837),  but 
Willstatter  and  Zollinger  (Annalen,  1916,  412, 
198)  first  isolated  and  described  this  substance, 
which  IB  a  mono-glucoside  of  oenidin.  The 
chloride  CfjM^fiifil,  deep  red  prisms  containing 
4  or  6HaO,  is  easily  soluble  in  water,  fairlv 
soluble  in  dilute  HCl,  easily  soluble  in  dilute  sul- 
phuric acid,  fairly  soluble  in  ethyl,  and  more  so 
m  methyl  alcohol.  With  ferric  chloride  it  gives 
no  colouration  ;  with  sodium  carbonate  an  acid 
solution  becomes  blue.  It  is  optically  active,  and 
W.  and  Z.  give  [a]c„«-.642<'  (±60''):  ^^ 
[a]oa~42r  (±30**);    its  absorption  spectrum 

shows  one  band.  PicraU,  bundles  of  carmine- 
red  needles,  difficultly  soluble  in  cold  water, 
easily  soluble  in  hot. 

Tb»  colour  reaction  with  alum,  described  by 

\^]lst&tter  and  collaborators  for  many  of  the 

pigments  of  this  series,  ii  due  to  traces  of  iron 

m  the  reagent  (A.  £.  Everest,  Proo.  Boy.  Soc. 

1918,  B.^,  260). 

Dtszno  Pbopebtiss  ot  thb  Anthooyams. 

The  anthooyanuis  and  anthocyanidins  are 
capable  of  dyeing  not  only  on  moraanted  wool, 
but  also  on  tannined  cotton,  and  indeed  some 
are  described  by  Willstatter  as  capable  of  dyeing 
unmordanted  wool. 

The  shades  obtained  vary  from  rose  to 
violet  and  blue,  and  are  fast  to  light,  but  very 
onstable  to  most  reagents,  and,  owing  to  pseudo- 
base  formation,  even  to  water. 

The  substances  prepared  by  Watson,  and 
mentioned  above,  resemble  the  natund  antho- 
ovans  in  tinctorial  properties,  though  some  of 
them  show  very  much  greater  fastness,  and  in 
this  respect  approach  the  requirements  of 
technical  practice. 


Everest  and  Hall  (private  communication) 
have  confirmed  the  fact  that  the  affinity  of  the 
anthocyans  for  tin-mordanted  wool  is  connected 
with  ike  phenolic  OH  groups  present  in  them. 
They  have  also  shown  that  their  affinity  for 
tannined  cotton  is  independent  of  these  groups^ 
but  dependent  upon  the  presence  of  the  pyxyliom 
ring.    Thus  the  coni  pound : 


CI 


0 


/ 


o 


II 


H 


which  ii  the  parent  of  all  the  anthocyanidins, 
has  no  affinity  for  tin-mordanted  wool,  but 
readily  dyes  tannined  cotton.  On  the  other 
hand  the  compound  from  which  the  above 
substance  is  formed  by  closing  the  pyrylium 
ring 

.  ^    .OH    CO— 
\/  I 

^0 


has  no  dyeing  properties. 

Further  ooservatioos  have  also  shown  that 
the  compounds  which  Watson  described  as 
dyeing  tm-moidanted  wool  also  fall  into  line  in 
respect  of  tannined  Qotton,  which  they  dye  very 

It  is  not  at  all  impossible  that  a  new  series 
of  technicslly  useful  colours  for  tannined  cotton 
may  result  from  further  research  in  this  fiekL 

For  fuller  details  the  original  papers,  or 
The  Natural  Organic  (colouring  Matters,  Perkin 
and  Everest  (Series  of  Monographs,  Longmans), 
should  be  consulted.  A.  £.  £. 

AMTHOKIRRIN.  The  yellow  crystalline 
matter  of  the  flowers  of  the  yellow  toadflax 
{Linaria  vtUgaru).  Formerly  used  as  a  dyeing 
material,  but  the  colour  is  not  permanent. 

ANTHOKTAM.  The  expressed  juice  of  the 
sweet  or  purple  violet  {V%ola  odonUa),  gently 
heated  to  89*,  then  slammed,  cooled,  and 
ffitered.  A  little  rectified  spirit  is  then  added, 
and  the  following  day  the  whole  ia  again  filtered. 
Used  to  make  syrup  of  violets,  and  to  colour  and 
flavour  liqueurs. 

AMTHOPHACIN.  A  term  given  by  Mdbius 
(ChesL  Zentr.  1901,  L 190)  to  the  brown  colouring 
matter  of  flowers. 

AMTHRACENBCmH.o.  D&BOovered  by  Dumas 
and  Laurent  in  the  highest  boiling  portion  of 
coal  tar,  and  termed  by  them  paranaphihtdene 
(Annalen,  5,  10) ;  further  examined  by  jLaiirent, 
who  re-named  it  mUhracene  (Annalen,  34,  287) ; 
first  obtained  pure,  and  its  composition  deter- 
mined, by  IVitisohe  (Annalen,  109,  249),  and 
more  exactly  studied  by  Anderson  (Annalen, 
122,  294 ;  OienL  Soc.  Trans.  16,  44). 

Occurrence. — Anthracene  is  one  of  the  pro- 
ducts of  the  destructive  distillation  of  coal,  and 
is  found  in  the  tar;  the  average  yield  of  the 
pure  hydrocarbon  is  about  0-3  p.c.  of  the  tar 
obtained. 

A  new  source  of  anthracene  has  been  an- 
nounced (Dingl.  poly.  J.  246,  429)  in  the  tax 


ANTHRACENE. 


345 


obtained  when  the  zeiidue,  left  after  the  illumi- 
nating oils  have  been  distilled  from  Baku  petro- 
leum, is  allowed  to  fall  on  pumioe  in  red-hot  iron 
retorts.  1000  kilos  of  naphtha  residue  under 
these  conditions  yield  500  o.m.  of  gas,  used  to 
heat  the  retorts,  and  300  kilos,  of  tar,  containing 
about  0*2  p.o.  of  pure  anthracene.  The  supply 
of  the  naphtha  residue  is,  however,  too  limited 
to  render  anthracene  from  this  source  a  serious 
competitor  with  that  from  coal  tar. 

According  to  Elliott  (Amer.  Chem.  J.  6, 
248),  the  tar  obtained  in  the  manufacture  of 
gas  by  the  destructive  distillation  of  li^t 
petroleum  naphtha  boiling  below  150^  contams 
2*63-2*90  p.c.  of  anthracene.  A  remarkable 
production  of  anthracene,  during  the  distillation 
of  the  higher-boiling  portions  of  crude  phenol, 
has  been  observed  bv  Kohler  (Ber.  18,  859). 

Anthracene  is  obtained  by  the  distillation 
of  ihein  with  zinc-dust  (Oesterle  and  Tesza, 
Arch.  PhamL  1908,  432),  but  this  production 
is  of  no  commercial  value. 

PreparcUion  (Auerbach,  Das  Anthracen  nnd 
seine  Derivate;  Kopp,  J.  1878, 1187;  Perkin, 
Jonm.  Soc.  Arts.  27,  572 ;  Lunge,  Ck>al  Tar  and 
Ammonia). — Anthracene  ia  obtained  from  the 
'green  grease '  which  forms  the  last  portion  of 
the  *  heavy  oil  *  or '  dead  oil  *  of  the  tar  distiller ; 
this  at  first  is  greenish-yellow  in  colour,  but 
turns  more  brown  by  the  action  of  the  air,  and 
becomes  semi-solid  on  standing,  owing  to  the 
separation  of  solid  substances.  It  contains, 
amonffst  other  substances,  naphthalene,  methyl 
naphtihalene,  anthracene,  methvl  anthracene, 
phenantiuene,  chrysene,  carbazoi,  and  acridine, 
together  with  hydrides  of  anthracene  and 
phenanthzeoe  and  other  high-boiling  liquids. 
When  no  further  separation  occurs,  the  mass  is 
subjected  to  filtration,  either  in  a  centrifugal 
machine  or  a  filter  press,  first  in  the  cold  uid 
finally  at  40*'  (Gessert,  Bingl.  poly.  J.  196,  543) ; 
or  ia  filtered  through  strong  linen  bags,  and 
afterwards  submitted  to  hydraulic  pressure  in  a 
press  so  ananged  that  the  plates  can  be  heated 
with  steam  and  the  cake  hot-pressed.  A 
notable  quantity  of  anthracene  remains  dis- 
solved in  the  expressed  oil,  and  especially  in 
the  portions  separated  when  the  temperature  is 
raiseid,  and  is  recovered  by  redistilling  and 
working  up  the  product  as  just  described.  The 
hard  yellowish-green  cake  obtained,  containing 
25-40  p.c.  of  pure  anthracene,  is  ground  to  a 
fine  powder  in  nulls  and  heated  with  coal-tar 
na]^thaj[b.pw80''-100°),  solvmt  naphtha  (b.p. 
12(r>190^),  creosote  dl,  or  petroleum  spint 
(b.p.  70^-100''),  in  laige  iron  vessels  provided 
wiwi  stirrers.  Petroleum  spirit  is  to  be  pre- 
ferred (Perkin),  since  it  dissolves  less  anthracene 
whilst  the  impurities  are  sufficiently  soluble 
in  it  to  be  removed  if  the  quantity  of  solvent 
employed  ia  2-3  times  as  great  as  that  of  the 
antnraoene  to  be  purified.  Solvent  naphtha, 
consisting  essentially  of  xylenes,  pseudo-cnmene 
and  meatylene,  is  extensively  employed,  as 
phenanthrene  is  much  more  soluble  than  anthra- 
oeoa  in  this  solvent.  It  does  not,  however, 
remove  the  oarbazole,  which  is  usually  present 
to  the  extent  of  14-18  p.c.  When  creosote 
oil  is  used,  it  must  be  free  from  naphthalene ; 
the  advantage  of  using  creosote  oil  is  that 
it  dissolves  out  the  methyl  anthracene,  the 
anthracene  being  practically  insoluble  therein. 


The  residue  contains  from  45-50  p.c.  of  the 
hydrocarbon,  but  inasmuch  as  it  is  not  readily 
reduced  to  powder,  and  unless  finely  divided 
is  only  sloww  attacked  by  oxidistng  agents,  it 
is  subUmed  by  passing  steam,  heated  at  220*^- 
240^,  over  the  melted  product,  and  condensing 
the  vapours  in  a  chamber  by  jets  of  water. 
The  anthracene  thus  obtained  ia  in  leafy  masses, 
containing  from  60-GO  p.c.  of  the  hydrocarbon, 
the  chief  impurities  consisting  of  carbazole 
(10-12  p.o.),  phenanthrene,  pyrene,  chrysene, 
and  other  hydrocarbons,  together  with  small 
quantities  of  phenols  of  hish  boilinff-point,  and 
of  acridine ;  it  can  readily  oe  ground  to  a  paste, 
and  is  now  suffidentiy  pure  for  conversion  into 
anthraquinone  by  oxidation.  If,  however, 
dichloranthracene  is  required,  further  purifica- 
tion ia  necessary;  this  can  be  effected  by 
distillation  with  caustic  potash,  whereby  im- 
purities such  aa  carbazole  and  bodies  of  a 
phenolic  character  are  retained,  and  anthracene, 
together  with  phenanthrene,  distils  over  with 
no  ffreater  loss  than  occurs  if  the  60  p.c.  product 
ii  (Sstilled  alone ;  caustic  soda  cannot  oe  sub- 
stituted for  the  potash,  since  it  produces  no 
purification  of  any  consequence.  Instead  of 
distilling  washed  anthracene,  (100  parts)  with 
caustic  potash,  Perkin  employs  a  mixture  of 
Montreal  potash  (30  parts),  which  usually 
contains  potassium  hydroxide  in  considerable 
quantities,  and  caustic  lime  (6  parts).  Unless 
lime  is  used,  the  residue  in  the  retorts  forms  a 
hard  cake,  which  can  be  removed  only  with 
difficulty.  Hydrogen  is  evolved  during  the 
distillation.  The  distillate  is  freed  from  phen- 
anthrene by  washing  with  coal-tar  naphtha,  and 
the  residue  is  a  very  pure  anthracene.  This 
production  of  phenanthrene,  even  from  anthra- 
cene which  has  been  freed  from  this  impurity  by 
extraction  with  solvents  previous  to  distillation 
with  caustic  potash,  is  noteworthy  and  points  to 
the  probable  existence  of  molecular  compounds 
of  phenanthrene  with  other  of  the  impurities  of 
the  washed  anthracene,  which  are  destioyed 
during  the  distillation  with  caustic  potash.  This 
process  of  Perkin  has  been  subjected  to  con- 
siderable criticism.  According  to  Auerbach,  a 
loss  of  anthracene  to  the  extent  of  10  p.c.  occurs, 
and  this,  added  to  the  cost  of  fuel  employed, 
renders  it  the  most  costiy  method  of  purification 
yet  devised.  The  ereat  advantage  of  the 
method,  however,  is  uiat  it  brings  anthracenes 
of  different  origins  to  a  similar  condition  of 
purity ;  even  pitch  anthracene— obtained  by 
the  distillation  of  gas-tar  pitch  in  iron  retorts 
with  the  aid  of  sup»-heated!^steam,  and  generally 
unsuitable  for  purification  owine  to  the  difficulty 
of  removing  nigher  hydrocan)ons  associated 
with  it — ^works  perfectiy  well  alter  it  has  been 
subjected  to  this  process. 

Many  modifications  in  the  method  of  puri- 
fying crude  anthracene  have  been  introduced. 
A  method  based  on  the  far  greater  solubility 
of  the  impurities  in  mixtures  of  aniline,  pyridine, 
or  quinoline  bases,  has  been  patented  by  the 
Chemische  Fabriks-Actiengesellschaft  in  Ham- 
burg (D.  R.  P.  42053  of  AprU  15,  1887).  The 
crude  anthracene  is  dissolved  at  100*  in  lj|-2 
times  its  weight  of  a  dehydrated  and  rectified 
mixture  of  tar  bases  (pyrioines)  separated  from 
the  light  oil  obtained  in  tar  distillation  (compare 
D.  R.  P.  34947  and  36372),  and   the  solution, 


346 


ANTHRACENE. 


on  cooling,  yielda  a  crystalline  separation  of 
anthracene  almoat  free  trom  carbazolo  and  its 
homologues.  The  patentees  state  that  a  33  p.o. 
anthracene  dissolved  in  1*75  times  its  weight 
of  pyridine  bases  yields  on  crystallisation  an 
82'5  p.o.  anthracene,  whilst  when  dissolved 
in  £wice  its  weight  of  a  mixture  of  equal  parts 
of  pyridine  bases  and  benzene,  it  yields  an 
80  p.c.  anthracene,  and  in  twice  its  weight  of  a 
mixture  of  equal  parts  of  benzene  and  aniline  a 
75  p.c.  anthracene.  The  recovery  of  the  an- 
thiabene  contained  in  the  mother  liquors  offers 
no  special  difficulty. 

Remy  and  Erhart  (D.  B.  P.  38417  of  Jan.  19, 
1886)  have  proposed  crystallisation  from  oleic 
acid  as  a  means  of  purification  of  crude  anthra- 
cene. The  difficulty  of  recovering  the  anthra- 
cene contained  in  the  mother  liquors  would  seem* 
however,  to  deprive  this  method  of  technical 
importance. 

Graham  (Chem.  News,  33,  99,  168)  has 
devised  a  method  for  recovering  anthiaceue 
horn  the  filtered  oils  used  in  its  purification. 

The  Farbmfabriken  voruL  Friedr.  Baever  & 
Co.  (D.  R.  P.  68474 ;  Eng.  Pat.  5539 ;  J.  Soc. 
Chem.  Ind.  1893,  439)  employ  liquid  sulphur 
dioxide,  which  dissolves  the  impurities  of  crude 
anthracene,  but  very  little  anthracene  itself. 
600  kUos.  crude  anthracene  is  mixed  in  a  wrought 
iron  agitator  with  2400  kilos,  liquid  sulphur 
dioxide,  first  exhausting  the  air  and  then  allowing 
the  sulphur  dioxide  to  enter.  The  reaction 
having  ceased,  the  mass  is  forced  by  its  own 
vapour  pressure  into  an  iron  steam-jacketed, 
filtering  tower,  where  anthracene  of  70-80  p.c. 
remains  behind.  The  mother  liquor  is  distilled, 
the  sulphur  dioxide  bein^  collected  and  recon- 
densed  by  means  of  an  air-compreasor. 

Another  patent  of  the  same  firm  (D.  R.  P. 
78861;  Eng.  Pat.  7862;  J.  Soo.  Chem.  Ind. 
1895,  361)  recommends  the  use  of  acetone  or 
other  fatty  ketones  as  a  purifying  agent. 
560  kilos,  crude  anthracene  is  stirred  in  a  steam- 

t'acketed  cylinder  with  750  kilos,  acetone  for  an 
lOur.  After  cooling  the  separated  anthracene 
is  filtered  and  washed  with  375  kilos,  acetone. 
The  second  liauor  is  used  over  again,  and  the 
first  is  distilled  to  recover  the  acetone.  From 
crude  stuff  containing  34  or  35  p.o.  anthracene, 
an  article  of  82  p.o.  is  easily  made,  and  only  a  few 
per  cent,  anthracene  remain  in  the  residue  after 
distilling  off  the  acetone.  The  acetone  may  be 
used  in  the  form  of  '  raw  acetone '  or  *  acetone 
oils.' 

Welton  (Eng.  Pat.  27559 ;  D.  R.  P.  113291 ; 
J.  Soc.  Chem.  Ind.  1900,  139)  purifies  crude 
anthracene  by  means  of  liquid  (anhydrous) 
ammonia,  which  dissolves  out  most  of  the 
impurities,  but  not  the  anthracene  itself. 

Luyten  and  Blumer  (Eng.  Pat.  14892; 
D.  R.  P.  141186 ;  J.  Soc.  Chem.  Ind.  1901,  796) 
state  that  when  anthracene  is  purified  by 
solvents  such  as  naphtha,  acetone,  &c.,  the 
presence  of  tar  oil  in  the  crude  anthracene  is 
oeneficial.  25  parts  of  drained  crude  anthra- 
cene are  heated  with  35  parts  of  naphtha  until 
the  temperature  is  near  that  of  the  solvent. 
On  cooling,  the  anthracene  crystallises  out  and 
is  filtered  and  washed  with  a  little  of  the  solvent. 
It  is  dried  by  heating  to  fusion,  and  distilling 
off  the  solvent ;  80  p.c.  anthracene  is  obtained 
by  this  method. 


The  Aktien  Gesellsobaf t  fur  Theer  und  Erdol 
Industrie  (D.  R.  P.  111359 ;  Eng.  Pat.  7868 ; 
J.  Soo.  Chem.  Ind.  1899,  750)  heat  crude 
anthracene  to  fusion,  and  allow  it  to  cool  until 
50  p.c.  has  crystallised,  when  the  mother  liquor 
is  run  off  and  again  allowed  to  crystallise.  The 
second  crop  can  be  raised  to  the  value  ol  the 
first  (45-50  p.c.)  by  another  fusion.  This 
product  is  again  fused  and  treated  with  caustic 
potash  lye  (50  p.c.)  in  quantity  sufficient  to 
react  with  the  oarbazole  present.  When  the 
reaction  is  complete,  the  mabs  separates  into  two 
layers,  the  lower  part  being  potassium  carbazole. 
The  upper  anthracene  layer  is  run  into  its  own 
volume  of  90*s  benzol,  which  dissolves  any 
phenanthrene.  The  anthracene  is  pressed  or 
centrifuged,  and  again  washed  with  the  same 
rolvent,  and  is  obtamed  as  a  pale-brown  powder. 
By  this  means  30  p.c.  anthracene  is  raised  to 
90  p.c.  {v.  also  Scholvien,  Fr.  Pat.  335013; 
J.  Soc.  Chem.  Ind.  1904, 113). 

The  Aktien  Gesellschaft  fur  Anilinfabrik 
(D.  R.  P.  178764;  J  Soc.  Chem.  Ind.  1907, 
1193)  add  potassium  hydroxide  to  the  melted 
crude  anthracene,  which  is  then  distilled  in 
vaeud,  the  anthracene  distilling  over  being 
passed  into  some  solvent  in  which  it  is  soluble 
at  the  temperature  of  the  reaction,  and  from 
which  it  crystallises  on  cooling.  It  is  stated  that 
95-96  p.c  of  the  anthracene  is  recov»«d  as  a 
product  containing  95-98  p.c.  of  pure 
anthracene. 

Wirth  (Eng.  Pat.  14462 ;  J.  Soo.*Ghem.  Ind. 
1901,  464)  senarates  the  oarbazole  by  means  of 
its  easily  soluble  nitroso-  compound.  C^de 
anthracene  is  mixed  in  a  vessel  provided  witii  a 
stirrer  with  light  coal-tar  oil  and  sodium  nitrite. 
Dilute  sulphuric  acid  is  added  gradually,  and  the 
sodium  sulphate  which  is  formed  is  dissolved  in 
water  and  separated  from  the  light-oil  layer. 
The  anthracene  is  filtered  from  the  lieht  coal- 
tar  oil,  washed  with  benzene,  and  dried.  It 
contains  75-95  p.c.  anthracene,  according  to 
quality  of  the  crude  material. 

Catchpole  (Eng.  Pat.  16641;  D.  R  P. 
164508 ;  J.  Soc  (£em.  Ind.  1903,  1190)  places 
the  crude  product  in  the  form  of  blocks  or  slabs 
on  a  perforated  or  channelled  surface  in  a 
chamber  suitably  heated  to  a  temperature  not 
exceeding  200*,  whereby  the  impurities  are 
'  sweated '  out.  A  slight  washing  with  add 
and  distillation  complete  the  process. 

Vesehr  and  Votocek  (Ens.  Pat.  27596; 
J.  Soc.  Chem.  Ind.  1905,  191)  find  that  concen- 
trated sulphuric  acid  extracts  the  whole  of  the 
basic  impurities  of  anthracene  from  a  solution 
of  crude  anthracene  in  a  solvent  immiscible 
with  sulphuric  acid.  The  most  suitable  solvents 
are  mineral  and  coal-tar  oils,  but  carbon  disul- 
phide  and  chloroform  may  be  used ;  100  parts 
of  crude  anthracene  (35  p.c.)  are  dissolved  in 
300  parts  of  solvent  naphtha,  100  parts  of 
concentrated  sulphuric  acid  axe  added,  and  the 
mixture  is  heateid  and  at  the  same  time  vigo- 
rously agitated  for  a  few  minutes.  The  sulphuric 
acid  having  been  drawn  off,  the  solution  is 
freed  from  acid  by  agitation  with  calcium 
carbonate,  filtered,  and  then  allowed  to  crystal- 
lise By  this  process  it  is  stated  to  be  possible 
to  obtain  an  85-90  p.c.  anthracene,  perfectly 
free  from  .carbazole. 

A  troublesome  impurity  in  anthracene  is 


ANTHRACENE. 


M7 


a  peculiar  parmffin,  wfakh  hae  a  high  molting- 
pointy  and  is  only  sparingly  solubfe  dther  in 
Ught  petiolBum  or  ooal-tar  naphtha ;  it  is  dis- 
s^veci  to  a  oartain  extent  by  these  solvents 
when  hot,  bat  on  cooling  is  almost  entirely 
deposited  sffain.  A  small  quantity  left  in  the 
anthraoene  uequently  impedes  succeeding  opera- 
tions, and,  owing  to  its  stability,  passes  through 
most  of  the  proceases  without  change. 

Synikeaea, — ^From  orthotolTlketone,  by  heat- 
ing with  dnc-dust  (Behr  and  Van  Dorp,  Ber.  7, 
17) ;  from  orthobromobenxylbromide,  by  the 
action  of  sodium  (Jackson  and  White,  Ber.  12, 
1965) ;  from  a  mixture  of  benzene,  acetylene 
tetrabromide,  and  aluminium  chloride  (Ansohiits, 
Annalen,  235,  156);  from  beny^ne  and  alu> 
minium  chloride  under  tiie  influence  of  nickel 
carbonyl  at  100°  (Dewar  and  Jones,  Ghem.  Soc. 
Tians.  1904,  213) ;  and  by  treatmg  pentachlor- 
ethane  in  benzene  with  aluminium  chloride, 
when  anthraoene  is  formed  through  the  inter- 
mediate formation  of  perchlorethylene  (Mouney- 
rat,  BuU.  Soo.  chim.  19,  [3J  557).  An  interest- 
ing synthesis  resulting  in  the  production  of 
methyl  anthraoene  ][m.p.  200°)  is  tmit  of  Kraemer 
and  Spilker  (Ber.  1890,  3174).  By  the  inter- 
action of  xylene  and  oinnamene,  phenvltolyl- 
pentane  is  formed,  which  when  passed  through 
a  led-hot  tube  forms  methyl  anthracene  (m.p. 
207°),  hydrogen  and  metlume  being  evoiYed. 
This  synthetical  production  of  methyl  anthracene 
is  of  importance  in  its  relation  to  the  present 
theories  of  the  mode  of  formation  of  anthracene 
in  coal  tar. 

The  following  syntheses  in  the  anthracene 

roup  have  been  carried  out  in  recent  years. 

'ineral  acids  convert  homopiperonyl  and  homo- 
▼eratryl  alcohols  into  derivatives  of  2.3.6.7.- 
tetrahydroxy-9. 10-dihydroanthracene 

CHjO/NcHjOH  ,  f^CH, 

CHjOls^  HO-CH,!s^OCH, 


t 


=  2H,0  -f 


CH 
CH 


CH, 

:oOCO 

CH, 


OCH, 
OCH, 


the  tetramethoxy  compound  being  obtained  in 
quantitative  yield  by  the  condensation  of 
▼eratrole  with  f omuJctehyde  in  the  presence  of 
60  p.c.  sulphuric  add  (Robinson,  Chem.  Soc. 
Trans.  107,  267).  Maffnesixmi  phenyl  bromide 
reacts  with  ortho-phthiualdehydic  acid  in  boiling 
anisole  solution  to  produce  ortho-a-benzhydryl- 
benzhydrol  HO0H(CeH.)C.H.-C(C.H5),OH, 
and  this,  when  boiled  with  hycurobromio  acid, 
is  converted  into  9.10-diphenyIanthraGene  (Simo- 
nis  and  Remmert,  Ber.  48,  406).  Purparin 
(1.2.4-trihydroxyanthraquinone)  may  be  syntbo- 
sised  by  condensing  phtnalio  anhydride  with  hy- 
droxyquinol,  whilst  by  using  4-hydroxy-phtha£o 
anhydride,  hydroxyflavopurpnrin  ( 1.2.4. 6-tetra- 
hydroxyanthraquinone),  identical  with  the  oxi- 
dation product  of  flavopuipurin,  is  obtained 
(Dimrotn  and  Fick,  Annalen,  411,  315). 

Propertiea, — ^Anthracene  crystallises  in  glis- 
tening white  scales.  It  melts  at  213°,  and  boils 
at  300^  (Ullmanxi*  Enzykl).  When  pure 
it  shows  a  bluish-violet  fluorescence,  but  this 
is  concealed  if  small  quantities  of  yellow  im- 


purities (Fritx8che*s  ohiysogen)  are  present. 
Tellow-cdk>ured  anthracene,  on  exposure  to 
sunlight,  is  bleached,  and  becomes  fluoresoeiit, 
but  under  these  conditions  the  hydrocarbon 
undeigoes  conversion  into  paranthracene 
(Ci«Hio), — a  peculiar  modification,  which  is 
much  less  soluble  than  anthracene,  is  unattaoked 
by  bromine  and  nitric  acid  at  100^,  and  does 
not  combine  with  picric  acid ;  it  melts  at  244°, 
and  is  thereby  eonverted  into  ordinary  anthra- 
cene (Fritzsche,  J.  pr.  Chem.  101,  333  ;  Graebe 
and  Liebermann,  Annalen,  Suppl.  7,  264; 
Schmidt,  J.  pr.  Chem.  [2]  9,  248).  Accordins  to 
Luther  and  Weigert  (Ch.  Ztrbl.  1904,  u.  117 ; 
1905,  L  1152),  anthraoene  in  the  solid  state,  as 
well  as  in  solution,  yields  para-anthracene.  The 
fluorescence  of  anthraoene  and  certain  of  its 
derivatives  has  been  referred  by  Liebermann  to 
a  particular  molecular  grouping  (Ber.  13,  913). 
Meyer  (Zeitsoh.  physikal.  Chem.  1897,  468) 
attnbutes  fluorescence  to  the  presence  of  what 
are  known  as  fluorphoric  groups,  which  must 
be  situated  between  two  heavy  atomic  groups, 
usually  benzene  nuoleL  For  a  discussion  of  the 
cause  of  fluorescence  in  anthracene,  see  Steven- 
son (J.  Phvsiol.  Chem.  1011,  15,  845).  The 
solubility  of  anthracene  in  100  parts  of  various 
solvents  has  been  determined  by  Versmann 
(Jahresbericht.  1874,  423),  Perkin  (Journ.  Soc 
Arts,  27,  598 :  v.  Becchi,  Ber.  12, 1978),  Findlay 
(Chem.  Soo.  Trans.  1902, 1221)  with  the  following 

results : — 

Parts  of  anttiraceiis 
Alcohol  (absolute  at  16°  dissolves  0*076  (B.). 


»f 


ft 


tf 


tr 


it 


tf 


tt 


>» 


b.p. 
8p.gr. =0-800  at  15^ 
=0-825 
=0-830 
=0-835 
=0-840 
=0-860 


tt 


»» 


>f 


f> 


»f 


rt 


if 


»> 


tt 


Ether 
Chloroform 
Carbon  disulphide 
Acetic  acid 
Light  petroleum 


t> 


»> 


tf 


f» 


ff 


tt 


» 


» 


» 


» 


>» 
» 


»> 


*> 


i> 


i> 


0-830  (B.). 
0-591  (V.). 
0-574  (V.). 
0-491  (V.). 
0-475  (V.). 
0-460  (V.). 
0-423  (V.). 
1-175  (V.). 
1-736  (V.). 
1-478  (V.). 
0-444  (V.). 
0-394  (V.). 


)• 


b.p.  70°-100* 

at  15°  dissolves  0*115  (P.). 

Benzene     .         .    „  „       1*296  (F.). 

..    b.p.  80°-100°  „  „       0-976  (P.). 

Toluene      .         .  at  16-6°     „       0*920  (B.). 

at  b.p.       „      12-940  (B.). 


ft 


According  to  Hildebrand,  EUefson,  and  Baebe 
(J.  Amer.  Chem.  Soc.  1917,  39,  2301),  the 
solubilities  of  anthracene  at  25°,  in  grams  per 
100  grams  of  the  solvents,  are  as  follows  : — 

Alcohol  ....     0-328 

Benzene  .         •         .1-86 

Carbon  disulphide  .         .         .2-58 
Carbon  tetrachloride       .         •     0*732 
Ether  „  .         .1*42 

Hexane       „  .         .     0*37 

When  introduced  into  an  alcoholic  solution 
of  picric  acid  saturated  at  30°-40°,  anthracene 
forms  a  picrate  CuHicC.HJNO^JjO,  crystal- 
lising in  glistening  red  needles  wnioh  melt  at 
138° ;  it  is  decomposed  into  its  constituents  by 
alcohol,  water,  and  dilute  alkalis,  even  in  the 
cold.  The  formation  of  the  picrate  is  best 
obtained  by  warming  molecular  quantities  of 
anthraoene  and  picric  add  on  the  water-bath  in 


348 


ANTHRACENE. 


chloroform  lolutioii.  On  oxidation  with  po- 
tAMum^  diohroxQAte  or  manganese  dioxide  and 
Bolphorio^  aoid,  anthracene  ia  converted  into 
anChiaqninone,  whilst  strong  nitric  acid  oxidises 
it  to  anthraqninone  and  dinitroanthraqiiinone ; 
nitro-  deriyatives  of  anthracene  can,  howeyer, 
be  raepared  by  the  action  of  strong  nitric  acid 
on  the  hydrocarbon,  if  care  is  taken  to  decompose 
any  nitrons  add  which  may  be  formed  dazing 
the  reaction  (Perfcin,  Ghem.  80c.  Proc.  1889, 13). 
Electrolytic  oxidation  in  acetone  yields  anthra- 
qninone (Fontana  and  Perkin,  Ghem.  Zentr. 
1904,  iL  708) ;  the  same  product  results  by  the 
eleotrolytio  oxidation  of  a  suspension  of  antlua- 
cene  in  a  2  p.  a  solution  of  cerium  sulphate  in 
20  p.c.  sulphuric  acid  at  80''~90^  (Farb.  vorm. 
Meister,  Lucius,  and  Bruning,  D.  R.  P.  162063 ; 
Ghem.  Zentr.  1904,  li  71) ;  or  by  the  oxidation 
of  anthracene -by  cerium  oxide  in  sulphuric  acid 
(Farb.  M.  L.  &  B. ;  D.  R.  P.  168609 ;  Ghem. 
Zentr.  1906,  i.  840) ;  or  by  heating  anthracene 
with  charcoal  at  160^-300^  (Dennstedt  and 
Hasslfir,  D.  R.  P.  203848 ;  Ghem.  Zentr.  1908. 
iL  1760). 

Conoentrated  sulphuric  add  converts  anthra- 
cene  into  snlphonio  adds.  Anthracene  mono- 
sulphonic  add  is  obtained  by  the  direct  sulphona- 
tion  of  anthracene  with  sulphuric  add  ox  63**  or . 
64*B.,  and  about  60  p.o.  of  the  anthracene 
employed  is  thus  converted.  If  sulphuric  acid 
of  66*B.  IB  used,  two  isomeric  diBulphonic  acids 
ace  obtained,  and  these,  on  oxidation,  yield  two 
anthraquinonediBulphonic  acids,  which  are 
isomeric  with  the  two  acids  obtained  by  the 
direct  snlphonation  of  anthraquinone.  The 
/9-anthracene  disulphonic  add,  after  oxidation 
with  chromic  or  nitric  acids,  and  subsequent 
fusion  with  alkali,  yields  alizarin  (g.ff.),  and  the 
monosulphonio  acid  similarly  treated  yields 
anihrapurpurin  {q.v.)  (La  Sodl^t^  Anonomye  des 
Matidres  Golorantes  et  Produits  Chemiques  de 
St.  Denis,  Eng.  Pat  1280 ;  J.  Soc.  Ghem.  Ind. 
1894,  32). 

The  same  acids  are  obtained  by  heatins 
anthracene  with  alkali  bisulphate  to  140M60* 
(D.  R  P.  77311).  Anthracene  is  readily  attacked 
>by  chlorine  and  bromine,  and  3ridds  with  each 
element  a  series  of  additive  and  substitution 
derivatives;  additive  compounds,  apparently, 
are  the  first  products  of  the  action,  and  these 
dther  decompose  during  the  reaction  or  can  be 
decomposed  oy  boiling  with  alcoholic  potash 
into  the  coiresponding  substitution  derivatives, 
which  also  form  adaitive  compounds  by  the 
further  action  of  the  halogens.  The  chloranthra- 
cenes  are  now  prepared  on  a  large  scale  (Glayton 
Aniline  Go.,  Eng.^at.  8744 ;  J.  Soc.  Ghem.  Ind. 
1906,  64).  Dry  chlorine  reacts  with  anthracene 
in  the  presence  of  lead  peroxide  at  a  high 
temperature.  Fifty  parts  by  weight  of  anthracene 
and  10  parts  of  dry  powdered  kad  peroxide  are 
treated  with  dry  chlorine  at  220*  until  the 
weight  has  increased  to  120  parts.  The  tempera- 
ture, however,  may  be  varied  between  180*  and 
260*,  and  the  compodtion  of  the  product  varies 
with  the  temperature  employed  and  the  amount  of 
chlorine  absorbed.  The  product  consists  mainlv 
d  jB-tetnohloranthracene  (m.n.  162*),  which 
is  readily  soluble  in  benzene  ana  crystallises  out 
in  yeUow  needles,  and  another  psxt  much  less 
soluble  in  benzene  and  more  highly  chlorinated. 
This  latter  consists  of  two  products :  hexachlor- 


anthracene  (m.p.  277**),  which  ciystailises  from 
nitrobenzene,  and  heptachloranthracene  (m.p. 
232*),  which  is  more  soluble  in  benzene  than 
the  former.  Oxidation  converts  theee  com- 
pounds into  ohloranthraquinones,  containing 
2  atoms  of  chlorine  less  than  the  original  com- 
pound. Treatment  with  a  mixture  of  nitric 
and  sulphuric  acids  results  in  the  formation  of 
chlomitroanthraquinones  which  yidd  dvestuA 
on  treatment  with  fuming  sulphuric  ado.  The 
ohloranthraquinones  on  treatment  with  fuming 
sulphuric  acid  in  the  presence  or  absence  oi  boric 
ada,  yield  hydroxy-  compounds;  €,g,  1 : 4 
dichloranthraquinone  yields  quinizarin  (g.v.) 
(Farb.  vorm.  F.  Baeyer  &  Go.,  A,  Pat.  386368 ; 
J.  Soc.  Ghem.  Ind.  1908, 667).  Reducing  age^tci, 
such  as  sodium  amalgam  or  phosphmus  and 
hydrogen  iodide,  convert  anthracene  into  the 
dihydnde  (Graebe  and  Liebermann,  Lc. ;  Liel)er- 
mann  and  Topf.,  Annalen,  212,  6);  hydrogen 
and  nickd  oxide  at  260*-270*  and  100-125 
atmos.  convert  anthracene  first  into  tetrahydro-, 
then  decahydro-,  and  finally  perhydroanthracene 
(Ipatie£E,  JokowlefF,  and  Rakitin,  Ber.  1908, 
996). 

EainuUion.'—Lncik  (Ber.  6,  1347);  Meister, 
Lucius,  and  Bruning  (Diogl.  poly.  J.  224,  659); 
Nicol  (Ghem.  Soc.  Trans.  1876,  2,  663) ;  BaaaeU 
(Ghem.  News,  73,  178 ;  19^  167).  The  per- 
centage of  anthracene  in  a  sample  of  the  00m- 
mercial  product  is  determined  oy  oxidising  it 
to  anthraquinone  with  chromic  add,  dissolving 
the  product  in  sulphuric  acid,  and  precipitating 
with  water,  since  the  associated  impurities  are 
either  destroyed  during  the  oxidation  or  aio 
converted  into  sulphonic  acids  soluble  in  water. 
The  details  of  the  process  are  as  follows :  1  gram 
of  anthracene  ia  introduced  with  46  0.0.  of  aoetio 
add  into  a  flask  connected  with  a  reversed 
condanser,  and  heaiied  to  boilmg ;  a  sdutkm  of 
16  srams  of  chromic  add  in  10  ao.  of  aoetio 
acid  and  10  o.c.  of  water  is  then  added,  drop  by 
drop,  to  the  boiling  solution  during  a  pericxl  of 
2  lioors;  and  the  product  is  boiled  for  2 
hours  longer,  allowed  to  stand  for  12  hours, 
then  poured  into  4(X)  cc  of  water,  and,  after 
standmg  for  8  hours  longer,  is  filtered.  The 
anthraquinone  on  the  fiUer  is  washed  with 
water,  with  hot  dilute  alkali,  and  then  with  hot 
water ;  afterwards  it  is  placed  in  a  small  dish 
dried  at  100*,  and  digested  for  10  minutes  with 
10  times  its  weight  of  pure  conoentrated  sulphuric 
add  at  100*.  The  solution  of  anthraquinono 
in  sulphuric  add  is  then  allowed  to  remain  tor 
12  hours  in  a  moist  atmosphere,  mixed  with 
200  0.0.  of  water,  and  the  precipitated  an^ra- 

auinone  filtered  off  and  washed  nrat  with  water, 
ien  with  dilute  alkali,  and  finally  with  water ; 
it  is  then  dried  at  100*  in  a  dish,  weighed,  i^^nited, 
and  the  ash  deducted  from  the  first  weighing. 
The  difference  gives  the  weight  of  anthraqumone 
corresponding  to  the  amount  of  antnraoena 
present  in  the  sample. 

Impwriiies. — Paraffin  is  usually  present  ia 
crude  anthracene,  and  is  estimated  bv  treating 
the  material  with  fuming  nitric  acid,  keeping 
the  mass  cold.  When  adl  the  add  has  been 
added,  the  mixture  is  kept  at  the  ordinazr 
temperature  until  the  anthracene  has  dissolved, 
and  then  heated  until  the  paraffin  has  melted. 
The  solution  is  filtered  and  the  predpitate  wmahad 
wiUi  fuming  nitric  add  until  the  filtrate  dis- 


ANTHRANOL. 


849 


■olves  in  water  without  turbidity,  and  then  with 
water  until  nentral.  Finally,  the  paraffin  w 
washed  witk  alcohol,  dissolved  in  warm  ether 
and  the  filtrates  collected  in  a  weighed  ponelam 
dish;  the  filtrates  are  evaporated  and  the 
paraffin  dried  at  106»-110«  for  half  an  hem 
(Heualer  and  Herde,  J.  Soo.  Chom.  Ind.  18M, 
828).  Kraemer  and  Spilker  (Muspratt-Bnnt^ 
▼ii  70)  use  the  following  method:  10  grams 
finely.powdered  anthracene  are  shaken  with 
100  o.i  ether  for  ten  minutes  and  mixture  then 
allowed  to  settle.  60  c.c.  of  the  clear  Bolution 
axe  then  evaporated  and  the  residue  dned  at 
100^  for  haH  an  hour.  After  cooling,  Uie  residue 
is  finely  ground,  8  c.c.  fuminj  sulphuric  acid 
(20  p.c.  SO.)  added,  weU  mixed,  •^  t^hole 
heated  to  lOO*'  for  three  hours,  with  f^qj©** 
stirring.  Ck)nt«nts  of  dish  are  then  waAed  b  tt 
means  of  600  c.c.  hot  water  into  a  besjker, 
filtered  through  a  dry  filter  and  the  whole 
washed  with  cold  water,  until  filtrate  is  free 
from  sulphuric  add.  Moisten  filter  with  absolute 
alcohol  and  wash  the  paraffin  into  a  weighed 
dish  by  means  of  ether,  removing  last  traces  of 
paraffin  from  the  beaker  in  the  sama  manner, 
fiiraporate  ether  solutions  and  dry  residue  for 
half  sa  hour  at  106*  ;  and  weigh  as  pure  pwaffin 
The  detection  of  carbazole  and  phenanthrene 
in  the  purified  product  is  carried  out  as  f ol- 

CafhazoU,  Sample  is  extracted  in  cold 
with  ethyl  acetate,  solution  allowed  to  evaporate, 
and  residue  transferred  by  a  few  drops  of  same 
solvent  to  a  watoh-glass  On  ev^njtion, 
carbazole  is  left  behind;  when  treated  with  a 
droo  of  nitrobenzene  and  phenanthraquinone, 
it  yields    characteristic  small   copper-coloured 

Phenanthrene.  Sample  is  extracted  with 
benzene,  and  the  evaporation  residue  treated 
with  a-dinitrophenanthraqumone  m  mtrob^- 
zene.  In  this  case  mixed  crystals  are  ob- 
tained  having  the  form  and  colour  of  tne 
blown  needles  of  the  phenanthrene  com- 
pound,  but   containing   a    large   quantity  of 

'"'AHraRACEinS  ACID  BROWH.    CHROMB 
BLACK,  -RED,  -YELLOW  v.  Azo-  coLOTOnffQ 

**^AHTHRACElfBGRBBlI.  Corttfeln  and  C«m. 

lOn    8.    {v.    AUXABIH   AHD  ALLOD    OOLOUWl^a 

MATTXBS;  also  XAiriHm  ooLouBiiro  uattmbs), 
ABTHRAOERE VIOLET.  OaOHniv.  Auzabik 

AHD  AJJJMD  OOLOUWirO  MATTIB8 ;  alsO  XaKTHINB 
OOLOUXIHO  MATTXBS). 

ABTHRACHRTSOMB  r.  Aloabih  and  allied 
ooLOUBnro  icattxbs. 
AMTHRACITB  V,  FusL. 
AMTHRACITE  black  v.  Axo-  ooLOUBiNO 

MATTXBS.  

ABTHRACOXEBE  «.  Bisms. 
ABTHRACTL  CHROME   GREEN   v.    Aio- 
ooXiCUBnra  mattxbs. 

ANTHRAFLAVIC   ACID   v.  Aliiabih   Am 

AiJ.Tmn  OOLOlTBnrO  MATTBBS. 

ABTHRAGALLOL  v.  Alibabth  ahd  allibd 
ooLOUBnro  mattbbs. 

ABTHRAGALLOL  DIMETHYL  ETHERS 
V.  Gbat  boot. 

AKTHRANO,  ANTHRAMILIC  ACID  (o- 
aminobentdc  acid)  v.  Amikobbnzoio  acid  akd 

HOMOLOOUBS. 


ANTHRABOL.    9'Hydroxyatdhraeefi€ 


C.H, 


is  prepared  by  the  redaction  of  anthraquinone 
with  hydriodic  acid  and  phosphorus  (Liebermann 
and  Topf,  Annalen,  212,  6 ;    Ber.  1876,  1201), 
or  with  tin  and  acetic  acid  (Liebermann  and 
Gimbd,  Ber.  1887,  18M).     Another  method  is 
to  add  copper  or  aluminium  powder  to  anthra- 
quinone   dissolved    in    concentrated    sulphuric 
acid  at  30*-40*,  and  pour  the  product  into  water. 
The    crude    substance    is    recrystallised    from 
glacial  acetic  acid  conteiniug  a  trace  of  aluminium 
and  a  little  hydrochloric  acid  (Baeyer  &  Co. 
D.  R.  P.  201642;   Chem.  Zentr.  1908,  ii.  1218, 
Bezdizk  and  Friedlander,  Monatsh.  30,  871). 
It  is  also  obtained  when  50  parte  of  finely 
divided  anthraquinone  are  mixed  with  10  parte 
of  iron  and  1000  parte  ferrous  chloride,  ana  the 
mixture  heated  to  200°  C.  or  higher,   until   it 
dissolves  in  sodium  hydroxide  solution  with  a 
yellow   colour.    The    product   is    then    cooled 
and  washed  with  water,  the  residue  dissolved 
in  sodium  hydroxide  solution,  and  filtered  into 
hydrochloric  acid  (D.  B.  P.  249124).     Anthranol 
has   been   83mthesi8ed   by   heating    1    part   of 
o-benzylbenzoio  acid  with  2  parte  of  sulphuric 
acid  at  100°  (Fischer  and  Schmidt,  Ber.  1894, 
2789).    It    crystallises    in    colourless    needles, 
m.p.  105°,  with  decomposition.    It  dissolves  in 
alkalis,  and  then  behaves  as  ite  teutomeride 
anthrol  {q.v.) ;    e.g.  it  condenses  with  benzal- 
dehyde  to  form  benzilidine  anthrol  (Haller  and 
Padova,  Compt.  rend.  141,  857 ;    v.  also  Bad. 
Anil,  und  8oda  Fab.  D.  R.  P.  172930 ;   Chem. 
Zentr.  1906,  ii.  834).     By  heating  the  alkaline 
solution  of  anthranol  for  some  time,  it  becomes 
oxidised    to    anthraquinone;     hydroxylamine 
hvdrochloride  converte  it  into  anthraquinone- 
dioxime   (Nieteki  and   Kehrmann,   Ber.    1887, 
613).    Anthranol  vields  a   benzoyl  derivative 
(m.p.  164°)  with  benzoyl  chloride  in  pyridine 
(Psdova,  Compt.  rend.  143,  121 ;    Ann.  C%im. 
Phys.  [8]  19,  353),  and  a  diiodide  with  iodine 
in  benzene  solution  (Liebermann,  Glawc,  and 
Lindenbaum,  Ber.  1904,  3337). 

Kurt  Meyer  (Annalen,  1911,  379,  37)  has 
obtained  the  two  desmotropic  forms  of  anthranol, 
namely,  anthrone  and  anUiranol : 


CCJ) 


AOH) 


and 


Anthione. 


Anthranol. 


The  keto-form  is  prepared  by  reducing  anthra- 
quinone with  tin  and  hydrochloric  acid,  and 
subsequent  predpitetion  with  water.  It  melte 
at  154°,  ana  is  almost  completely  insoluble  in 
cold  alkali  solutions.  On  solution  in  boiUns 
dilute  sodium  hydroxide,  rapid  cooling  and 
precipitetion  with  dilute  well-cooled  sulphuric 
acid,  the  yellow  anthranol  is  obtained.  It 
melte  at  about  152°,  dissolves  readily  in  most 
solvento,  being  converted  into  anthrone.  Solu- 
tions of  anthranol  show  a  strong  fluorescence, 
those  of  anthrone  no  fluorescence.  Thiele*s 
assumption  that  the  high  reactivity  of  phenols 
is  due  to  a  change  to  the  keto-type  seems  to 
be  contradicted  here,  for  in  the  aoove  pair  of 


350 


ANTHRANOL. 


oompoundB  the  hydrozylio  form  is  the  mor« 
active  isomeride. 

Bwmoanthrone  is  obtained  when  bromine  is 
added  to  a  cold  saturated  solution  of  anthrono 
in  GS,.  It  crystallises  in  yellow  needles,  and 
melts  at  148^.  On  boiling  with  aqneons  acetone 
it  yields  ozanthzone,  which  ciystallises  in 
colonrless  needles,  melting  at  167°.  Solutions 
of  ozanthrone  are  colourless  and  do  not  fluoresce. 
On  boiling  with  aqueous  alkali  it  passes  into  the 
desmotropic  form  anthraquinol,  which  is  also 
formed  wnen  anthraquinone  is  reduced  by  zinc- 
dust  and  alkalh  It  crystallises  in  brown  leaflets, 
which  dissolve  in  solvents  with  a  yellow  colour 
and  an  intense  green  fluorescence. 

\/\c(OH)A/^ 

Anthraqutnol. 


0 


\)H(OH)/ 

Oxanthrone. 


By  the  oxidation  of  anthracene  in  glacial  acetic 
add  solution  with  lead  peroxide  (1  mol.  C^Hm  ; 
1  mol.  PbO,)  anthranoi  acetate  is  produced,  but 
if  in  the  proportions  of  1  mol.  O14H10 ;  2  mols. 
PbOt,  then  oxanthrone  acetate  results.  The 
former  melts  at  127°,  and  is  readily  hydrolysed 
to  anthranoi,  the  latter  melts  at  108°-109°. 
Again,  by  dissolving  anthracene  in  glacial  acetic 
acid,  pouring  into  water  and  passmg  chlorine, 
oxanthrone  is  obtained  in  about  75  p.c.  yield 
(K.  Meyer,  Ix,).  Oxanthrone  is  aJso  obtained 
by  the  following  method  (D.  R.  P.  250076), 
3*4  parts  of  anthracene  are  dissolved  in  200 
parts  acetone,  and  then  precipitated  by  the 
addition  of  200  parts  ice-cold  water.  6*4  parts 
of  bromine  are  added,  with  continual  shabng, 
all  goes  into  solution,  much  cold  water  is  added, 
and  the  oxanthrone  is  precipitated.  It  crystal- 
lises from  toluene  in  Ions  yellowish  needles. 

DiarUhrancl  C.mHisO,  is  formed,  together 
with  a  little  anthraquinone,  when  anthranoi 
dissolved  in  benzene  is  expos^  to  sunlight  for 
some  weeks,  or  when  the  benzene  solution  is 
boiled  for  some  hours.  It  is  also  obtained  by 
oxidising  anthranoi  with  ferric  chloride,  in 
glacial  acetic  acid  solution,  or  (D.  R.  P.  223209) 
ov  heating  100  parts  anthraquinone,  500  parts 
of  water,  50  parts  sodium  hydroxide,  and  50 
parts  zinc-dust  in  an  autoclave  for  six  hours  at 
160°  C.  The  reaction  mixture  is  then  precipi- 
tated by  the  addition  of  acid,  and  recrystallised 
from  methyl  alcohol.  On  oxidation  with  potas- 
sium nermanganateityields  dianthroneCagHieOs, 
a  yellow  ciystalline  solid  which  blackens  at 
300°  0.  Dianthranol  crystallises  in  colourless 
Ubular  crystals  (m.p.  250°)  (Omdorff  and  Bliss, 
Amer.  Ghem.  J.  1896,  459  {  Omdorff  and 
Cameron,  Amer.  Chem.  J.  1895,  658). 

AMTHRAMOLa  of  CHRYSOPHANIC  ACID 
and  KMOMM  HBTHTL  ETSER  v.  GHBysABOBiir. 

AHTHRAPUBPUROI  v.  Auzabiv  avd  allixd 

OQLOUBUfO  MATTXBS. 


Obtained  by  the  oxidation  of  anthracene  with 
chromic  acid  (Kopp,  Jahresbericht  1878,  1188  ; 
Laurent,  Ann.  Chim.  Phys.  [2]  60, 220 ;  72, 415 ; 
Annalen,  34,  287:  Anderson,  Annalen,  122, 
301 :  Qraebe  and  Liebermann,  Annalen,  SpL  7, 
285) ;  by  the  distillation  of  calcium  benzoate 
(Kekul^  and  Franchimont,  Ber.    1872,  908); 


by  the  distillation  of  benzoic  acid  with 
phosphonis  pentoxide ;  by  the  distillation  of 
o-benzoylbenzoic  acid  with  phosphorus  pentoxide, 
or  by  heating  it  alone  (UUmanny  Annalen,  291, 
24 ;  Behr  and  Dorp,  Ber.  1874,  578 ;  Lieber- 
mann, Ber.  1874,  805;  Perkin,  Chem.  80c. 
Trans.  1891,  1012) ;  by  the  dry  distillation  of 
calcium  phthalate  (Panaotovit-s,  Ber.  1884,  13). 
Hellor  (Zeitscb.  angew.  Chem.  1006,  19,  669) 
heats  1  part  of  phthalic  aiUivdride  with  3*5  parts 
of  benzene  and  1*8  parts  oi  aluminium  chloride 
in  a  lead  vessel  at  70*  until  the  evolution  of 
hydrogen  chloride  ceases.  After  cooling,  water 
is  added  and  the  excess  of  bensene  removed  by 
steam  distillation.  The  solution  is  made 
alkaline  and  boiled,  and  then  on  addition  of 
acid  benzoyl  benzoic  acid  is  precipitated.  On 
heating  this  for  one  hour  at  150*,  anthraquinone 
is  obtained  (c/.  Piccard,  Ber.  1874,  1785; 
Friedel  and  Crafts,  Ann.  Chim.  Phys.  [6]  1,  523 ; 
MliDer,  J.  1863,  393).  Phenyf-o-tolylketone 
gives  anthraquinone  on  heating  with  lead  oxide 
or  on  oxidation  with  manganese  dioxide  and 
sulphuric  acid  (Behr  and  Dorp,  Ber.  1873,  754 ; 
1874,  16  ;  Thorner  and  Zincke,  Ber.  1877,  1479). 
Industrial  preparation. — Crude  anthraoene 
(55-60  p.c.)  is  slowly  added  to  a  hot  solution 
of  sodium  dichromate  in  a  large  wood  vat 
lined  with  lead.  The  solution  is  kept  well 
stirred  and  heated  with  steam  until  all  the 
anthracene  has  been  added.  The  steam  is 
then  cut  oft  and  sulphuric  acid  is  run  into  the 
mixture  in  the  form  of  a  fine  spray ;  the  heat 
ffenerated  by  the  reaction  kee^  the  solution 
boiling.  The  crude  anthraoumone  is  then 
separated  by  filtration  and  oried.  It  is  dis- 
solved in  sulphuric  acid  without  applying  any 
heat,  and,  when  solution  is  complete,  trannerred 
to  a  large  vat  lined  with  lead  and  boiled  with 
water.  The  precipitated  anthraquinone  is  at 
once  separated  by  means  of  filter  presses 
from  the  soluble  compounds ;  the  pressed  cakes 
are  boiled  with  a  solution  of  soda,  and  then 
again  filtered,  pressed,  dried,  and  finally  sub- 
limed (Levinstein,  J.  Soc.  Chem.  Ind.  1883, 
219;  Kopp.  /.c).  Poirrier  and  Rosenstiefal 
(Eng.  Pat.  8431 ;  J.  Soc.  CSiem.  Ind.  1887, 
595)  oxidise  anthracene  in  a  closed  lead-lined 
vessel  by  means  of  ferric  sulphate.  The  vessel 
is  heated  to  120*-150*  during  72  hours,  com- 
pressed air  being  injected  into  the  vesseL  By 
this  means  the  antluraoene  is  virtually  oxidised 
by  the  air,  the  ferric  sulphate  acting  as  a  carrier 
for  oxygen.  The  Farbenfabrik  vorm.  Meister, 
Lucius  und  Bruning,  state  that  an  -  almost 
quantitative  yield  of  anthraquinone  is  obtained 
by  the  electrolytic  oxidation  of  anthracene  in 
20  p.c.  sulphuric  acid,  in  the  presence  of  cerium 
salphate  (D.  R.  P.  152063 ;  Eng.  Pat.  19178, 
1902).  Another  process  consists  in  the  absorp- 
tion of  nitric  oxides  diluted  with  air,  by  zinc 
oxide,  copper  oxide,  or  a  similar  oxide  of  low 
basicity.  Anthraoene  is  mixed  with  this,  and 
a  stream  of  air  or  oxyeen  is  passed  through  the 
mixture    at    250°-35i^,    anthraquinone    beinff 

Sroduced  (Gh.  Fabr.  Griinau,  Landshoff  una 
[eyer,  D.  R.  PP.  207170,  215335;  J.  Soc 
GheuL  Ind.  1909,  360,  1310).  On  the  use  of 
oxides  of  nitrogen  and  nitric  acid  for  oxidising 
anthracene,  aee  D.  R.  PP.  234289,  254710, 
256623.  Meister,  Lucius,  and  Bruning  (D.  R.  P. 
292681)  make  a  mixture  of  100  parts  30  p.a. 


ANTHRABUFDSr. 


851 


aqueous  anthracene  paste,  with  3000  parts 
water,  250  parts  26  p.c.  ammonia,  and  5  parts 
copper  oxide.  Oxygen  corresponding  to  3 
molecnies  per  moleoue  of  anthncene  is  forced 
in  and  the  whole  stured  and  heated  for  two 
hoars  at  170*^  C.  Darmst&dter  (Ghem.  Zentr. 
1900,  ii  151 ;  D.  R.  P.  109012)  prepares  aathra- 
qninone  by  ibe  electrolytic  oxidation  of  anthra- 
cene in  a  chromic-acid  bath.  Various  processes 
haye  been  patented  for  purifyinff  the  crude 
anthraquiaone  thus  produced.  Brenner  (J. 
Soa  casern.  Ind.  1882,  499 ;  1883,  410 ;  Eng. 
Pat.  769;  D.  R.  P.  21681)  dissolyes  out  the 
impuiitieB  on  a  specially  constructed  circular 
shdf .  The  methoa  depends  on  the  oontinuous 
extraction  of  the  impure  product  with  an  amount 
of  solyent  insu£Bci^t  to  keep  in  solution  the 
whole  of  the  anthraquinone  and  the  easily 
soluble  impurities.  Bayer  ft  Ck>.  (D.  R.  P. 
68474;  I^g.  Pat.  5639;  J.  Soc.  Chem.  Ind. 
1893,  439)  dissolye  out  the  impurities  with 
liquid  sulphur  dioxide;  Sadler  ft  Co.,  Ltd. 
and  Diiedger  (Eng.  Pat.  17635 ;  J.  Soc.  Chem. 
Ind.  1902,  1072)  reciystallise  the  omde  anthra- 
quinone from  hot  aniline.  The  chromium 
liquors  may  be  recoyered  and  used  again,  by  a 
process  of  electrolytic  oxidation  in  iron  ceUs 
which  are  lined  with  lead.  Strips  of  lead, 
hanging  in  the  cells,  act  as  cathodes,  and  the 
liquor  is  circulated  through  a  series  of  cells. 

Properiies, — ^Anthraquinone,  as  usually  pre- 
pared, forms  a  felted  mass  of  crystals  of  a  pale- 
yellow  or  buff  colour ;  by  sublimation  it  can  be 
obtained  in  the  form  of  lemon-yellow  needles  or 
golden-yellow  prisms ;  mj).  286^-286**  (corr.) ; 
b.p.  379**-381*  (oorr.)  (Recklinghausen,  Ber. 
1893,  1515);  Bp.gr.  1'438-1'419  (Schroeder, 
ibid.  1880,  1071 ;  Phillipi,  Monatsh.  1912,  33, 
373).  Sparingly  solab]^  in  alcohol  and  ether, 
somewhat  more  soluble  in  hot  benzene.  Accord- 
ing to  Hildebrand,  Eilefson,  and  Beebe  (J. 
Amer.  Chem.  Soc.  1917, 39, 2301),  the  solubilities 
of  anthraquinone  at  26^,  in  grams  per  100 
grams  of  the  solyents,  are  as  follows : — 

Alcohol          ....     0-437     * 
Ether 0104 

It  is  neutral  in  its  reactions,  and  is  insoluble 
in  dilute  acids  or  alkalis.  Anthraquinone  is 
yery  stable;  it  ia  not  affected  by  hot  hydro- 
chloric acid,  or  by  boiling  with  caustic  potash  or 
calcium  hydroxide  solutions ;  it  dissolves  in  hot 
nitric  acid  (sp.gr.  1  '4),  and  is  deposited  in  crystals 
on  cooling  or  on  dilution ;  it  di^lves  unchanged 
in  concentrated  sulphuric  acid  at  100°,  and  is 
precipitated  in  fine  crystals  on  pouring  into 
water.  Strongly  heated  with  sun>huric  acid, 
it  is  conyerted  into  mono-  and  di-sulphonic  acids 
{v.  Alizasin).  Anthraquinone  Ib  of  great  com- 
mercial importance,  as  it  is  used  in  the  prepara- 
tion of  alizarin,  quinizarin,  purpurin,  ftc.  {v. 
Alizarin).  Fusion  wi^h  zinc  or  treatment  with 
sodium  methoxide  converts  it  into  anthracene 
(Haller  and  Minguin,  Compt.  rend.  120,  1105) ; 
fusion  with  causuo  soda  converts  it  into  sodium 
benzoate  (Graebe  and  Liebermann,  Annalen, 
160,  129),  and  by  distilling  it  over  lime  benzene 
is  formed;  reduction  with  zinc  and  caustic 
soda,  or  with  sodium  amalgam  yields  oxanthranol 
C14H10O1  and  dianthranol  (Diels  and  Rhodius, 
Ber.  1909,  1076 ;  Meyer,  Ber.  1909,  143) ;  zinc 
and    amyl    alcohol  convert  it  into  dianthrol 


(Meyer,  Monatsh.  30,  165).  Phosphorus  penta- 
chloride  and  phosphorus  oxychloride  convert 
it  into  trichloranthnoene  and  other  chlorinated 
products  (Radulescu,  Chem.  Zentr.  1908,  ii. 
1032).  A  delicate  test  for  anthraquinone 
consists  in  r^ucing  it  with  sodium  amalgam  in 
dry  ether.  On  adding  a  drop  of  water,  a  red 
colouration  is  produced ;  if^  sJcohol  is  used 
instead  of  ether,  addition  of  water  gives  a  green 
colouration  (Glaus,  Ber.  1877,  927). 

The  following  method  serves  to  estimate 
anthraquinone  in  presence  of  anthracene,  and 
not  more  than  10  p.c.  of  phenanthraquinone, 
with  an  error  not  exceeding  0*3  p.c.  One  part 
of  the  crude  anthraquinone  is  wetted  with 
alcohol,  mixed  with  2  parts  of  zinc-dust,  and 
about  50  parts  of  hoi  5  ^.c.  sodium  hydroxide 
solution.  The  mixture  is  heated  just  below 
boiling-point  for  five  minutes,  and  then  rapidly 
filtered  and  washed  once  with  water.  The 
filter  with  the  residue  is  heated  with  another 
equal  portion  of  sodium  hydroxide  solution 
and  filtered  into  the  same  flask.  The  reddue 
is  again  treated  with  sodium  hydroxide  solution, 
and  if  it  imparts  no  red  colour  to  this  on  boiling, 
is  rejected.  Otherwise  the  liquid  is  filtered  off, 
and  the  residue  treated  with  sodium  hydroxide 
repeatedly  until  anthraquinone  is  shown  to  be 
completely  reduced  to  oxanthranol  and  removed, 
by  the  failure  of  the  residue  to  impart  a  red 
colour  to  boiling  sodium  hydroxide  solution. 
The  united  filtrates  are  cooled  and  reoxidised 
by  shaking  until  the  red  colour  disappears. 
The  anthraquinone  is  filtered  of!  on  asoestos, 
dried  at  110°,  and  weighed.  The  following 
precautions  are  necessary :  Boiling  with  alkan 
must  not  be  unduly  prolonged,  or  reduction 
may  proceed  so  far  that  anthraquinone  is  not 
reconstituted  on  mere  shaking  with  air,  and 
filtration  of  the  reduced  solution  must  be  rapid 
to  prevent  reoxidation  on  the  filter  (Lewis,  J. 
Ind.  and  Eng.  Chem.  1918,  10,  425 ;  Analyst, 
1918,  297). 

CondeTMOtum  products. — With  phenols : 
Scharwin  and  Kusnezof,  Ber.  1903,  2020 ;  1904, 
3616 ;  Deichler,  D.  R.  P.  109344 ;  Chem.  Zentr. 
1900,  ii.  360.  With  amines:  Bayer  ft  Ck>. 
D.  R.  PP.  86160, 107730, 136777, 136788, 148079; 
Chem.  Zentr.  1902,  ii.  1272 ;  Chem.  Soc.  Abst. 
1904,  i.  326.  Aiyl  ethers,  aryl-  and  alkyl- 
amino-  derivatives:  Bayer  ft  Co.  D.  R.  P. 
158531;  Fr.  Pats.  354717,  362140;  J.  Soc. 
Chem.  Ind.  1905,  885,  1105;  1906,  752.  Thio- 
cyanates  :  Bayer  ft  Co.  D.  R.  P.  206054 ;  J.  Soc. 
Chem.  Ind.  1909,  239.    Meroaptans :  ibid,  469. 

A  cooled  solution  of  anthraquinone  in  con- 
centrated sulphuric  acid,  when  treated  with 
aluminium  powder  with  constant  stirring,  yields 
anthraquinol  and  anthrone. 

1.2-  and  1.4-anthraquinones  have  been  pre- 
pared from  a-anthrol  and  1.2-anthraquinone 
from  3-anthrol  (v.  Dienel,  Ber.  1906,  926; 
Liebermann,  Ber.  1906,  2089 ;  Harlinger,  Ber. 
1906,  3537;  Lagodzinski,  Ber.  1894,  1483; 
1896,  1422  ;   1906,  1717). 

ANTHRAQUINONE  RED  v.  Auzabin  and 

ALLIBD  COLOUBIHG  MATTERS. 

ANTHRAQUINONE  SULPHONIO  ACIDS  v. 

Alizarin  and  Allhd  Colourino  Mattbrs. 

ANTHRAROBIN  v.  Chrysarobin. 

ANTHRARUFIN  v.  Alizarik  and  allisd 
ooLouBnro  mattisrs. 


ANTHRASOU 


AMTHRABOU  Jl  trade  name  for  a  pre- 
paration of  ooal-tar  with  the  colour  and  oon- 
■iftenoe  of  oliye  oiL 

AHTHROL 


^•^*<X> 


JELJ^OB) 


Two  isomeric  anthrob  are  known,  a-  or  1- 
hydroxyanthraocne  and  /3-  or  2-h7droxy- 
anthracene. 

a^AfUhrol  is  prepared  by  fusing  1-anthraoene- 
fiulphonic  add  with  5  parts  of  caustic  potash  at 
25(r,  dissolving  the  mass  in  water,  ana  filtering 
off  the  yellow  flocks  which  separate  out.  The 
cmde  prodact  is  recrystallised  from  acetic  acid 
and  water.  It  forms  yellow  plates,  nLp.  162^. 
a- Anthrol  dissolves  in  tne  ordinary  solvents  with 
a  bine  fluorescence,  and  is  more  soluble  than 
iS-anthrol  (Schmidt,  Ber.  1904,  66;  Dienel, 
Ber.  1906,  2862 ;  v.  also  Linke,  J.  pr.  Chem.  [21 
11,  227).  It  is  used  in  the  preparation  of 
alizarin-indiflo  G,  which  is  obtained  from 
dibromo-isatm  chloride  and  a-anthrol  (D.  B.  P. 
237199). 

fi- Anthrol  i»  prepared  by  fusing  2-anthracene- 
sulphonic  acid  with  potash  and  reorjystallising 
the  crude  product  from  acetone  (Liebermann 
and  Hdrmann,  Ber.  1879,  689;  Linke,  J.  pr. 
Chem.  [2]  11,  222).  It  can  also  be  obtained  o^ 
reducing  hydroxyanthraquinone  with  hydriodic 
acid  and  phosphorus  (Liebermann  and  Simon, 
Ber.  1881,  123).  It  forms  vellow  plates  melting 
with  decomposition  at  200'',  and  is  soluble  in 
the  common  organic  solvents  with  a  violet 
fluorescence.  By  reduction  with  sodium  in 
alcoholic  solution,  dihydroanthrol  is  obtained 
(Bamberger  and  Hoffmann,  Ber.  1893,  3069), 
and  by  heating  with  acetamide  at  280°  anthramin 
is  obtained.  Azo-  dyestuffs  have  been  obtained 
from  /3-anthrol  (Act.  Qes.  1  Anilinf.  D.  R.  P. 
21178 ;  Frdl.  L  638).  It  possesses  a  somewhat 
phenolic  character,  but  more  resembles  the 
naphthols  in  that  on  heating  with  ammonia  to 
20&'  G.  it  yields  the  eorresponding  anthramine. 
If,  however,  it  be  reduced  to  the  dihydro- 
anthrol, this  is  the  complete  analogue  of  phenol, 
and  does  not  condense  with  ammonia  to  the 
amine. 

AHTIAR  RESIN  or  UPAS  ANTIAR.  A 
green  resin  which  exudes  from  the  upas  tree 

iAfUiaris  tanearia  (Lesch.),  order  MaraceaB). 
Aaht  petroleum  and  benzene  extract  from  it  a 
BUDstance  analogous  to  caoutchouc,  a  fatty 
matter,  and  two  resinous  substances;  alcohol 
extracts  from  the  residue  a  very  poisonous 
glucoside,  atUiarin  (De  Vrij  and  Ludwig,  J.  pr. 
Chem.  103,  263). 

ANTIARIN  V.  Digitalis  ;  Glucosidis. 

AMTIARTHRIN.  A  trade  name  for  a  con- 
densation raoduct  of  saligenin  and  tannin. 

AIITI-(^LOR.  Linen  and  cotton  fibres  and 
paper  pulp  are  apt  to  retain  some  free  chlorine 
from  tne  hypochlorite  used  in  bleaching,  and 
as  this  causes  the  material  to  rot  slowly,  the 
manufacturers  use  certain  reagents  known  as 
*  anti-chlors  *  to  remove  the  last  traces  of 
chlorine.  The  first  substances  employed  were 
the  neutral  and  acid  sulphites  of  soda  (sodium 
sulphite  and  bisulphite) ;  these  were  superseded 
in  1863  bv  sodium  hyposulphite,  which  is  now 
very  lugely  employed.  Calcium  sulphide,  made 
by  boiling  milk  of  lime  with  sulphur ;  stannous 


chloride  in  hydroehlorio  acid  with  subsequent 
treatment  with  sodium  carbonate  to  neutralise 
any  free  add;  ammonia  and  sodium  nildte 
have  also  been  reoommended. 

AMTlDIABirriJIlL  Trade  name  for  a  pre- 
paration said  to  be  oompoeed  of  saccharin  and 
mannite. 

AXTIDni.    Phenyl  ether  of  glycerol. 

AMTI-FEBRIll.  A  trade  name  for  aeH- 
anilide  or  f^enylacHamide  CaHs'NH'CO-CH,. 
Discovered  by  Gerhardt  in  1 863,  and  investigated 
as  an  antipyretic  by  Knssmaul  in   1886  (v, 

ACJTAiriLIDE). 

ANTIFORMIH.  Trade  name  for  the  alkaline 
liouid  prepared  by  adding  caustic  soda  to  a 
solution  A  sodium  hypod^orite.  Used  as  a 
disinfectant,  the  active  ingredient  being  the 
chlorine,  of  which  4  p.a  is  liberated  on  treatment 
with  hvdrochlorio  add.  Solutions  of  sodium 
hvpochlorite  are  prepared  in  Germanv  by  the 
electrolysis  of  6  p.c.  salt  solution.  A  current 
of  110  volts  and  100  amperes  furmshes  nearly 
6000  litres  daily  of  a  dismfeoting  or  bleaching 
solution  contaimnff  1  p.o.  of  available  cUorine. 

According  to  fi.  Will  (Zeitsch.  Ges.  Brauw. 
1903,  866 ;  J.  Soa  C^iem.  Ind.  1904,  126),  it  is 
one  of  the  best  disinfectants  for  brewery  wcurk. 
It  rapidly  softens  oraanic  impurities  and  facili- 
tates their  removal  by  scounnff,  in  addition  to 
its  oxidising  action,  and  it  also  mssolves  incrusta- 
tion. Its  germicidal  power  is  high,  and  a  6  p.c 
solution  is  sufficient  for  most  purposes.  It  is 
used  cold,  and  may  be  safely  appfied  to  varnished 
surfaces  with  a  brush,  provided  care  is  taken  to 
prevent  prolonged  contact. 

ANTlFUNGIll.  Trade  name  for  magnesium 
borate,  employed  as  a  fungicide. 

AMTIGERMIN.  Trade  name  for  a  prepara- 
tion of  a  copper  salt  of  a  phenol-carboxyUc  add 
mixed  with  mne.    It  is  used  as  a  fungidda 

AMTIHYPO.  A  solution  of  potasdum  per- 
carbonate,  used  for  destroying  sodium  tnio- 
sulphate  in  photographic  negatives  and  prints. 

AHTILEFROL.  Syn.  for  chaulmoogra  oil  as 
used  inphannacy. 

AHTiLUETIII.  Potasnum-ammonium  anti- 
monyltartrate. 

AMTIMONIALS,  ORGANIC. 

Historieal.  The  first  oiganic  derivative  of 
antimony  was  synthesised  by  L5wi^  and 
Schweitzer,  who  prepared  triethylstibme  in 
1860  (Mitth.  d.  Zuroh.  NaturfoxMh.  GeseUschaft. 
1860,  46,  1 ;  Annalen,  1860,  76,  316,  327). 

This  synthesiB  was  inunediately  extended  by 
H.  Landolt  (Annalen,  1861,  78,  91),  and  further 
investigations  of  aliphatic  antimonials  were 
made  by  Hofman  (1867)  and  by  Buckton  (1860). 
The  first  aromatic  antimonials  were  prepared 
about  30  years  later  by  Michaelis,  who,  in  colla- 
boration with  Reese,  Hasenbaumer  and  others, 
developed  a  general  method  for  the  synthesis 
of  antimony  derivatives  .containing  one,  two,  or 
three  acyl  groups. 

In  1910  these  researches  were  revised  by 
Moigan  and  Mickiethwait  (Chem.  Soc.  Trans. 
191 1, 99, 2293),  who  showed  that  triphenylstibine 
on  heating  with  antimony  chloride  yields  both 
mono-  and  diphenylstibine  chlorides,  and  who 
determined  the  effect  of  the  antimony  oomplex 
on  the  orientation  of  a  nitro  group.  SimOar 
investigations  were  made  independently  by 
P.  May,  who  also  studied  the  reduction  of  the 


ANTIMONIALS,  ORGANia 


nitrated  arylantimony  compounds  and  arrived 
at  concordant  reaiilts  (Chem.  Soc.  Trana.  1912, 
101,  1033). 

The  diazo  synthesis  of  airl  antimony  com- 
pounds  was  first  employed  by  the  Ghemische 
Fabrik  von  Hoydon  <n  Dresden,  and  this  led  to 
the  synthesis  of  antimony  atozyl  and  antimony 
salvarsan  (Fabr.  Heyden.  D.  R.  P.  254421). 

Syntheses  of  aliphatic  antimonials  are  few 
compared  with  those  in  the  arsenic  series,  and 
are  attended  by  greater  experimental  difficulties. 
Syntheses  are  successful  only  when  the  more 
energetic  reagents  are  employed,  owing  to  the 
feebler  affinity  of  antimony  for  hydrocarbon 
radicals. 

Antimony  analo^es  of  certain  of  the  thera- 
peutic organic  arsemcals  have  been  prepared,  but 
although  when  tested  therapeuticaUy  they  show 
trypanocidal  power,  and  sometimes  confer 
immunitv  to  trvpanosomes,  yet  so  far  nothing 
comparable  with  the  specific  action  of  aromatic 
araenicals  has  been  observed.  Local  irritation 
has  been  found  to  accompany  subcutaneous 
introduction,  but  possibly  tms  disagreeable 
effect  might  be  overcome  by  intravenous 
injection. 

Stibacetin,  the  antimonial  analogue  of 
arsacetin,  has  been  tried  successfully  in  rendering 
mice  immune  against  various  strains  of  trypano- 
somes,  the  immunising  dose  being  one-t^th  of 
the  lethal  proportion.  Uhlenhuw  has  reported 
on  the  effect  of  this  drug  on  the  growth  of 
experimental  tumours  in  rats  and  mice  (Medizi- 
nisbhe  Klinik,  1912, 37).  Sulphoform  (triphenyl-. 
stibine  sulphide)  has  been  employed  medicinally 
as  a  remeay  in  skin  diseaaee. 

Synthssis  of  Aliphatic  Antimonials. 

I.  Intanetfon  of  an  Alkyl  HaUde  wiUi  an 
Alloy  of  Antimony. 

Ethyl  iodide,  chloride  or  bromide  reacts  with 
an  alloy  of  potassium  and  antimony  (12  p.c. 
potassium),  yielding  triethylstibine  and  tetra- 
ethylstibonium  halide.  These  products  are  not 
accompanied  by  any  antimonial  analogue  of 
ethylcacodyl. 

II.  Interaetton  of  an  Alkyl  HaUde  with 
Antimony. 

Methyl  iodide  heated  with  antimony  in  a 
sealed  tube  at  140^  yields  trimethyUttbine  dx- 
iodide  Sb(CH,),I,  (Buckton,  Joum.  Chem.  Soc. 
1860,  13,  120 ;  Jahreeber,  1860,  374). 

III.  Interaction  of  a  HetaUlc  Alkyl  with  an 
Antimony  Halide. 

Zinc  dimethyl  reacts  with  antimony  tri- 
chloride, giving  trimethylstibine  (Hofmann, 
Jahresber.  1857,  103,  357). 

The  Grignard  reaction  may  also  be  employed. 
Antimony  trichloride  treated  with  Grignard 
reagent  (magnesium  methyl  iodide)  gives  a 
60-70  p.o.  yield  of  trimethylstibine  (Hibbert, 
Ber.,  1906, 39, 160). 

Aliphatic  Antimonials. 

Trimdhylsiibine  Sb(GH,)..  SynthesiBed  by 
method  I.  (above),  and  is  oroinariiy  prepared  in 
the  same  manner. 

Colourless  liquid,  b.p.  806°,  D  1-523/15°; 
odour  of  onions,  soluble  in  ether,  slightly  soluble 
in  water  or  alcohol ;  spontaneously  inflammable 
Vol.  L— T. 


in  air  or  chlorine  (Landolt,  Annalen,  1851,  78, 
91 ;  Jahresber.  1861,  569). 

The  dicMaride  8b(GM,),a.,  and  the  corre- 
sponding dibromide  are  produced  by  direct 
addition  of  the  halogen. 

TeirameihyUiibmium  iodide  Sb(CH.)«T. 
Formed  by  direct  combination  of  trimethyl- 
stibine ana  methyl  iodide.  Hexagonal  plates, 
very  soluble  in  water  or  alcohol,  lees  so  in  ether ; 
bitter  saline  taste. 

TeiramethyUiiboHium  hydroxide^  deliquescent 
cxystalline  mass  obtained  oy  treating  the  iodide 
with  moist  silver  oxide;  resembles  caustic 
potash ;  its  salts  are  crystalline  and  devoid  of 
emetic  action. 

TridhyUibint  Sb(C,H5),.  Synthesised  by 
method  I.  (above),  and  ordinarily  prepared  in  the 
same  manner  or  by  method  III.  (above). 
Golourless  liquid,  b.p.  1585/730  mm.  D 
1*3244/16°,  odour  of  onions,  soluble  in  ether  or 
alcohol,  insoluble  in  water;  spontaneously 
inflammable  (L5wig  and  Schweitzer,  Annalen, 
1850,  75,  315 ;  Hofmann,  Annalen,  1857,  103, 
357;  Buckton,  Quart.  J.  Ghem.  Soc.,  1863, 
13,  116,  118). 

TtitradkyUlibtmium  iodide  Sb(G,H,)«I,liH,0. 
Hexagonal  prisms,  fairly  soluble  in  water,  more 
so  in  alcohol  and  lees  so  in  ether. 

Tetradhyldibonium  Aycifxxmie,  prepared  from 
the  iodide  and  moist  silver  oxide,  is  oily,  mia- 
cible  with  water  or  alcohol,  and  forms  crystalline 
but  hygroscopic  salts. 

Triamyl  eiibine  Sl^GsHi,),,  prepared  by 
method  I.  (above).  Fuming  liquid  heavier  than 
water,  oxidising  to  triamyhiibine  oxide 

Sb(G,H„),0 

SYNTHB8S3  OF  AbOMATIO  AnTIHONIALS. 

I.  Interaction  of  sodium  with  ehlorobenxene 
and  antimony  trichloride  in  beniene  solution. 

The  mixture  heated  for  24  hours  yields  tri- 
phenylstibine,  triphenyUtibine  dichloride  and 
diphenylstibine  trichloride.  Triphenylstibinc 
heated  under  pressure  with  antimony  tri- 
chloride gives  phenylstibine  dichloride  and 
diphenylstibine  chlonde,  the  sodium  conden- 
sation thus  leading  from  tertiary  to  primary 
and  secondary  antimonials. 

II.  Grignard  reaction.  Antimony  trichloride 
heated  with  magnesium  aryl  bromide  or  iodide 
ffives  triarylstibme  as  chief  product,  but  the 
diaryl  and  monaryl  antimony  compounds  may 
be  ootained  from  the  tertiary  stibine  by  heating 
with  antimony  trichloride  (Morgan  and  Mickle- 
thwait,  Z.C.,  cf.  Pfeiffer,  Ber.  1904,  37,  4621). 

III.  Dlazo  -  synthesis.  This  method  was 
discovered  by  the  Ghemische  Fabrik  von 
Heyden,  who  in  1911  showed  that  the  stibinio 
group  could  by  this  means  be  introduced  into 
aromatic  nuclei.  Phenylstibinic  acid  is  pre- 
pared by  diazotisiiu;  aniline,  which  is  tiien 
treated  with  a  cooled  solution  of  antimony 
trichloride  in  aqueous  sodium  hydroxide. 
After  some  hours  tlio  mixture  is  almost  neutral- 
ised with  dilute  sulphuric  acid,  and  the  phenyl- 
stibinio  acid  is  precipitated  from  tho  filtered 
solution  by  hydrochlorio  acid.  As  thus  pre- 
pared, phenylstibinic  acid  differs  appreciably 
from  specimens  obtained  vid  phenylstibinic 
chloride,  showing  decided  tendency  to  form 
sidts  with  ammonia  and  sodium  hydroxide. 

2  ^ 


351 


ANTIMONIAIS,   ORGANIC. 


]^HydroxypKenyUiib%nie  Acid 
HO-C.H4SbO(OH), 

and  p'Aminoj^tenylatibinic  Acid  {p-Stibanilic 
Acid)  NHaO.H4'SbO(OH).  are  both  prepared 
by  analogoiu  methods.  The  sodiam  sait  of  the 
latter  is  we  antimonial  analogue  of  atoxyl  (9. v.), 
and  has  similar  therapeutic  properties.  Aoetyl- 
/)-phenylenediamine  is  diazotised  and  converted 
into  aoetyl-j^-aminophenylstibinic  i^id  by  treat- 
ment with  alkaline  solution  of  antimony  tri- 
chloride. The  product  is  faydroljrsed  into 
p-aminophenylstiDuiic  acid. 

^  The  sodium  salt  of  acetyl-p-aminophenyl- 
stibinic  acid  is  *  stibacetin/  the  antimony 
analogue  of  *  arsacetin.' 

When  aoetyl-p-aminophenylstibinic  acid  is 
succesrively  nitrated  and  hydrolysed  with 
caustic  alkali  so  as  to  replace  the  aoetylamino- 
complex  by  hydroxyl,  the  scarlet  aUcau  salt  of 
Z-nitroA-hydroxyaiibinic  acid  separates.  This 
salt^  IS  also  produced  by  conyerting  o-chloro- 
aniline  into  p-chlorophenylstibinic  acid  (by  the 
above  diazo  reaction).  This  chloro-  compound 
is  nitrated  to  3-nitro-4-chlorophenylstibinic 
acid,  which  on  treatment  with  alkali  exchanges 
its  chlorine  atom  for  a  hydroxyl  group. 


OH 
NO, 


0 


f^NO, 


SbO(OH), 


8b 


bO{OH)i 


ABOMATIO  AVTIMOinALS. 

Phenyhtifrine  dichhride  CJEg'Sh-d^,  ooloar- 
less  crystals,  m.p.  SS" ;  b.p.  290° ;  very  soluble 
in  alcohol,  ether,  benzene,  or  light  petxoleum. 
On  warming,  the  odour,  which  is  at  first  faint, 
becomes  very  pungent  and  irritating  (Hasen- 
b&umer,  Ber.  1898,  31,  2912). 

Phenylstibinic  chloride  C^t'Sbd^,  is  prepared 
b^  saturating  an  ethereal  solution  of  phenyl- 
subine  chloride  with  chlorine,  and  is  oDtainiMl 
as  a  hygroscopic  crystalline  mass.  It  is  hydro- 
lysed by  water  into  phenyhtibinie  acid 

G«HsSbO(0H). 
a  white  powder  decomposing  above  200*';    in- 
soluble in  water ;  solubk  in  aqueous  alkalis  and 
in  glacial  acetic  add. 

Dipkenylatibine  chloride  (CJS.^)JSb'Ci,  odour- 
less crystals,  m.p.  68°  (Michaelis  and  Giinther, 
Ber.  1911,  44,  2316  ;  Moigan  and  Micklethwait, 
Ic, ;  Qriithner  and  Wiemik,  Ber.  1915, 48, 1749). 

Diphenyhtibine  iriMofide,  Colourless 
needles  with  one  molecule  of  water,  m.p.  180°. 
Formed  as  by-product  in  sjmthesis  I.,  being 
extracted  with  hot  dilute  hydrochloric  acid  from 
the  concentrated  mother  liquors  from  this 
reaction.  Treated  successivelv  with  (a)  alcohol 
and  dilute  ammonia,  or  with  (E)  aqueous  sodium 
hydroxide  and  aoetio  acid,  the  trichloride  ^elds 

DiphenyUiibinic  acid  (CcH»)t8bO'OH,  a 
granular  precipitate  insoluble  in  ammonia  or 
sodium  carbonate,  as  produced  by  the  first 
method,  or  in  a  form  sduble  in  these  reagents 
when  obtained  b^  the  second  method. 

TriphenyUtibtne  (C«Hs)^b.    Colourless,  tri- 


I 


clinic  pktes,  m.p.  48°  ;  b.p.  231-232°/i6-18  mm., 
above  360°/760  mm.  (with  partial  decomposi- 
tion); D  1-4998/12°  (Ghira,  Gazzetta,  1894, 
24  (i),  317).  Synthesised  by  method  L  (above). 
The  product  of  this  reaction  is  successively 
extracted  with  alcoholic  hydrochloric  acid  and 
light  petroleum,  the  latter  removing  the  rea  uired 
stibine,  which  is  then  predpitatea  by  duorine 
in  the  form  of  its  dichloride,  tois  bein^  reduced  bv 
hydrogen  sulphide.  The  product  is  recrvstal- 
lised  from  light  petroleum  (Michaelis  and  Reese, 
Annalen,  1886,  233,  45).  An  almost  quantita- 
tive  yield  can  be  obtuned  by  employing  the 
Grigxiard  reaction  (Moigan  and  Micklethwait, 
Chem.  Soc.  Trans.,  1911,  99,  2290). 

TH^yUtihine  dichioride  (C«H,),8b-a,. 
Formed  as  a  by-product  in  Method  I.  (above). 
Colourless  needles,  m.p.  143°. 

TriphenyUiibine  ndphidef  *  Sulphoform,* 
C«H,),8bS.'  White  ne^Jes,  m.p.  119-120°. 
Soluble  in  benzene,  chloroform,  or  slaoial  acetic 
add,  less  soluble  in  alcohd,  slightly  soluble  in 
ether.  It  has  been  used  sucMssfully  in  the 
treatment  of  eczema  and  other  sldn  diseases. 
It  is  prepared  by  the  carefully  r^ulated  action 
of  hydrogen  sulphide  on  the  alcoholic  ammonia 
solution  of  the  stibine  chloride  (Kaufmann, 
Ber.  1908,  41,  2761). 

TlBVALENT  AimMONY  DlBZVATIVBB. 

The  members  of  this  series  of  it«fa'n^^nU|if 
contain  the  stibino-group,— SbsSb— ,  and  were 
discovered  in  1911  by  the  Chemische  Fabrik  von 
Hevden,  who  succeeded  in  reducing  the  aromatic 
stibinic  acids. 

Stibinobenzene  0,H,*Sb :  Sb*C«Hs.  Pale 
yellow  powder,  insoluble  in  water,  soluble  in 
glacial  acetic  acid  and  chloroform.  Phenyl- 
stibinic  add  in  caustic  soda  solution  is  cautiously 
reduced  with  sodium  hydrosulphite,  and  the 
resulting  crude  product  extracted  with  a  mixture 
of  alcohol  and  benzene  containing  copper 
powder.  The  filtered  solution  contains  the 
purified  product. 

3 :  Z''Diamino8libinobemene 

NHj-CeH^Sb :  SbO  Ji^NH, 

Yellow  powder,  insoluble  in  water,  soluble  in 
glacial  acetic  add,  soluble  with  pronounced  de- 
composition in  mineral  adds.  Prepared  by 
treating  a  dilute  alkaline  solution  of  m-amino- 
phenylstibinous  chloride  -  hydrochloride  with 
a  filtered  solution  of  sodium  hydrosulphite 
magnesinm  chloride  and  sodium  hydroxide. 
3  :  Z'-DiaminoA  :  4'  " "    "  "    ' 


NH.  NH. 

H0/"^S8b !  Sb/     \0H 


the  antimonial  analogue  of  Salvarsan  base  is 
prepared  by  reducing  3-nitro-4-hydroxyphenyl- 
stibinic  add  with  alkaline  sodium  hydrosulphite. 
The  red  colour  of  the  sodium  salt  of  this  add 
disappears,  and  the  stibinic  compound  separates 
as  a  reddish-brown  predpitate,  soluble  in  aqueous 
alkalis  or  acids.  It  is  easily  acylated,  and  it 
condenses  with  aldehydes,  ft  can  be  diazotised 
and  yields  a  colouration  with  ferric  chloride. 
When  oxidised  with  alkaline  hydrogen  peroxide 
it  is  converted  into  colourless  3-amino-4-hydroxy> 
phenylstibinic  acid  (D.  B.  P.  268451). 


ANTIMONIALS,  ORGANIC. 


895 


MlSOELLANBOUS   ObQANIC  DxBIVATIVES   OF 

Anximony. 
Trkamphorylstibinic  chloride 


h^^<ci]j 


yd 

Sb< 


This  is  the  main  product  of  the  condensation 
of  the  sodinm  derivatiye  of  camphor  with 
antimony  triohloride.  It  is  soluble  in  benzene, 
from  wmch  it  is  obtained  in  colourless  crystals, 
malting  with  decomposition  at  244^ ;  it  is 
resolv^  b^  water  into  the  unstable  tricamphoryl- 
gtibinic  ae%d  (CioH,cO)tSb(OH)|,  decomposed  by 
dilute  aqneous  sodium  hydroxide,  and  by  boiling 
water  (MoKftn*  Mickfethwait  and  Whitby, 
Ghem.  Soo.  'mns.  1910,  97,  35). 

Phenylcydopentameihyhmestibine  (I.)  is  pre- 
pared by  the  Grignard  method  from  phenyl- 
stibine  (Uchloride  and  the  magnesium  compound 
of  ac-dibromopentane,  and  is  a  colourless, 
viscous,  unpleasant  wmAlling  oil,  b.p.  169-171^/ 
18-20  mm.  (in  GOi);  oxidises  on  exposure  to 
air. 


CH,-CH, 


k- 


NsbCeH, 


/' 


GH, 
.  II. 


When  a9-dibromobutane  is  employed  in  this 
condensation  phenyloycioleiramdhyleneaiibine 
(II.)  is  obtained  as  a  oolotu*le8s  oil  of  unpleasant 
odour,  b.p.  156-158°/20-22  mm.,  yielding 
oystaUine  dichloride  and  dibromide  (Griittner, 
Wiemik  and  Krause,  Ber.  1915,  48, 1473 ;  1916, 
49,  437). 

Bibliography. — Organic  Compounds  of 
Arsenic  and  Antimony  (Morgan,  London,  1918). 

G.  T.  M. 

ANTIMONIN.  Trade  name  for  antimony 
calcium  lactate,  used  as  a  tannin-fixing  mordant. 

ANTIMONITE.  Native  antimony  sulphide 
(v.  Antimonij). 

ANTIMONT.  {ArUimoine,  Fr. ;  AtUimon, 
Ger.)    Stibium,    Sym.  Sb.    At.wt.  120*2. 

Ocourrence, — ^Antimony  occurs  native  in 
small  quantities,  ocoadonallv  in  rhombohedral 
crystals,  at  Andreasberg  in  the  Hartz,  Przibram 
in  Bohemia,  Sala  in  SwMlen,  Allemont  in  France, 
in  the  United  States,  New  South  Wales,  and 
Quebec.  It  occurs  in  large  masses  in  Sarawak, 
Borneo. 

Combined  with  oxygen  as  the  sesquloxide 
Sb,0,,  it  occurs  in  antimony  bloom,  white  arUi- 
mony,  or  valentinitef  and  in  senarrnoniite,  being 
found  in  workable  quantities  in  the  Algerian 
provinoe  of  Constantine.  In  antimony  ochre 
or  cervaniite,  and  in  stibiconite  and  volgerite,  it 
occurs  as  antimonite  of  antimony  Sb^O^. 

Combined  with  sulphur,  it  occurs  as  stibnite, 
antimonite,  or  grey  antimony  ore  Sb^g.  In 
union  mth  evJphur  and  oxygen  together,  it 
forms  red  antimony,  antimony  blen&  or  ker- 
meaiU  8b,032Sb,S,. 

With  arsenic,  antimony  is  found  in  ofle- 
monOte  or  arsenical  antimony.  With  silver, 
in  diserasite. 


With  sulphur  and  metals,  antimony  forms  a 
number  of  stdphantimonites,  among  which  may 
be  mentioned  zirdcenite,  jamesonile,  boulangerite, 
and  feather  ore,  containing  antimony,  sulphur, 
and  lead ;  miargyrite,  pyrargyfite,  and  stephan- 
Ue^  containing;  silver;  berihierite,  containing 
iron,  and  anttmonial  copper  glance.  Antimony 
is  found  in  certain  ferruginous  waters. 

The  antimony  minerals  of  commercial  im- 
pK)rtance  as  ores  are  slibniie,  and  the  decompo- 
sition products  which  are  usually  associated 
with  it  and  sometimes  entirely  replace  it,  viz. 
kermesite,  valentinite,  senarmontHe,  and  cervant- 

Antimony  ored  occur  in  workable  quantities 
in  Mexico,  California,  North  and  South  America, 
Canada,  Australia,  Japan,  Borneo,  Cape  of 
Good  Hope,  New  Zealand,  Asia  Minor,  Austria, 
Hungary,  France,  Russia,  Siberia,  Serbia, 
Algiers,  Italy,  Spain,  Portugal,  Corsica,  and 
Sardinia.  Small  deposits  of  antimony  sulphide 
have  been  discovered  in  Cornwall,  Cumberland, 
and  Scotland. 

Antimony  ores  occur  in  the  south  of  Hu- 
peh  and  part  of  Sze-chuen  province  and  in  the 
provinces  of  Hu-nan  Kwei-chow,  Kwang-si,  and 
xun-nan.  Roughly  speaking,  this  vast  anti- 
mony belt  comprises  tne  entire  western  hi^  of 
China  south  of  the  Yang-tse-ELiang.  There 
are  smelting  and  refining  works  at  Woo-chow 
which  reduce  the  ore  mined  in  the  province  of 
Kwang-si,  exports  from  which  are  shipped  to 
Canton  and  Hong-Kong.  There  are  also 
important  works  at  Chang-sha,  the  capital  of 
Hu-nan  j^rovince,  exports  from  which  are 
shipped  vtd  Hankow  and  Shanghai  (Schoeller, 
J.  Soc.  Chem.  Ind.  1913,  32,  200). 

For  a  list  of  antimony-producing  countries, 
see  J.  Soc.  Chem.  Ind.  1915,  34,  1148. 

The  veins  in  which  stibnite  is  found  are 
usually  4-6  inches  in  width,  but  in  some  rich 
mines,  as  in  Nevada,  they  are  several  feet  across. 
The  gangue  materials  are  quartz,  with  some 
brown-spar  and  heavy  spar,  and  from  these 
the  sul^de  can  only  be  separated  by  hand- 
picking  or  liquation.  It  is  occasionally  found 
m  pockets,  when  it  is  usually  very  pure. 

By  far  the  most  general  ore  of  antimony  is 
the  sulphide,  but  in  some  cases,  as  in  Algeria,  the 
oxide  IS  found  in  workable  quantities,  and  in 
other  cases  both  oxide  and  sulphide  occur 
together. 

Eostraetion. — ^Metallic  antimony  and  its  com- 
pounds are  nearly  always  extracted  from  the 
ores  by  dry  methods.  Aceordinf  to  their 
BuitabiUtv  for  the  several  methods  oftreatment, 
the  ores  fall  into  two  broad  classes : 

(a)  Sulphide  ores  containing  over  40  p.o. 
stibnite. 

(6)  Sulphide  ores  containing  less  than  40  p.c. 
of  the  sulphide,  and  oxide  ores  of  any  grade. 
In  this  class  also  ma^  be  included  uquation 
residues  and  flue  deposits,  &o. 

Preliminary  treatment  of  Ores, — Ores  of 
class  (a)  are  used  for  the  production  of  the  metal 
by  the  English  process.  If  the  content  of 
sulphide  is  over  90  p.c.,  the  ore  requires  no 
preliminary  treatment,  but  less  pure  ore  is 
subjected  to  a  process  of  liquation,  m  which  the 
sulphide  is  melted  and  allowed  to  run  away 
from  the  eangue. 

The    rollowing    method  of    liquation   was 


366 


ANTIMONY. 


fonnerly  used  where  fuel  is  plentiful,  m  at 
Malboso,  in  the  Department  of  Ard^che,  Wolfs- 
beig  in  the  Hartz,  and  in  Hungary.  The  ore  was 
plaoed  in  small  lumps  in  a  number  of  conical 
pots  of  46  kilos  dapacity,  each  perforated  below 
and  standing  on  a  perforated  plate  over  a  sunken 
receiver.  Tne  pots  were  surrounded  by  fuel 
which  continued  to  bum  for  10  hours,  the  melted 
sulphide,  known  as  crude  antimony,  collecting 
in  the  receivers. 

At  La  Lincouln,  Wolfsberg,  and  Haute  Loire, 
the  pots  were  contained  in  a  reverberatory 
furnace.  At  SchmoUnitz,  in  Hungary,  the 
melted  sulphide  ran  through  channeb  into 
receivers  outside  the  furnace. 

At  Malbosc,  the  pots  are  replaced  by  cylin- 
drical tubes,  perforated  below  and  standing  on 
similarly  perforated  plates  above  the  receivers. 
Each  cylinder  has  a  capacity  of  600  lbs.  of  ore, 
four  being  heated  in  one  furnace.  Each  hss  a 
hole  at  the  side,  through  which  the  residues  are 
removed,  these  holes  oeing  closed  during  the 
heating.  The  receivers  are  of  day,  or  of  iron 
coated  with  olav. 

At  Ghang-Sha,  and  also  in  other  parts  of  the 
province,  crude  antimony  is  obtained  from  high- 
^[rade  (68  p.a)  ores  by  liqualioiL  The  process 
IS  carried  out  in  furnaces  each  of  which  holds 
two  clay  crucibles,  the  charge  for  each  omoible 
being  60  lbs.  of  ore.  The  crucibles  are  inclined 
and  perforated  at  the  bottom;  they  are  fired 
for  two  hours,  the  liquated  sulphide  oolleoting 
in  a  cavity  at  the  back  of  the  nunaoe,  whence 
it  is  ladled  into  iron  moulds  and  allowed  to 
solidify.  The  pasty  liquation  residue  is  dumped 
into  loose  iron  frames  formed  of  two  L-shaped 
pieces  in  which  it  cakes  together  on  oooung 
(Schoeller,  l.c). 

The  method  of  liquation  in 'reverberatory 
furnaces  is  used  in  some  places  where  ore  can 
be  mined  cheaply  but  fuel  is  dear.  The  con- 
sumption of  fuel  per  unit  of  sulphide  liquated  is 
least  with  this  type  of  furnace,  but  there  is  a 
considerable  loss  of  antimony  by  volatilisation. 
This  loss,  however,  can  be  prevented  by  the 
use  of  suitable  condensing  apparatus  such  as 
Herrenschmidt's  (v.t.). 

In  any  process  of  liquation  the  temperature 
must  be  carefully  rwulated,  as  too  low  a  tempera- 
tare  results  in  a  low  yield  of  sulphide,  the 
residues  containing  too  much  antimony,  while 
too  hi^h  a  temperature  increases  the  loss  by 
volatilisation. 

The  liquated  stibnite  contains  much  less 
sulphur  than  is  required  by  the  formula  Sb|Sp  j 
ana  Schoeller  has  shown  that  this  is  due  to  Uie 
presence  of  oxygen. 

Ores  of  class  (b)  are  either  roasted  to  the 
non- volatile  tetroxide,  or  to  the  volatile  triozide, 
or  are  subjected  to  one  of  the  direct  reduction 
processes. 

The  oxidation  of  the  sulphide  to  tetroxide 
takes  place  at  temperatures  oetween  360^  and 
400^  in  presence  of  excess  of  air.  If  the  ore  is 
impure,  antimonates  of  the  metallic  impurities 
are  formed  at  the  same  time.  During  the 
roasting  there  is  a  great  tendency  for  the  ore 
to  frit,  and  this  necessitates  the  constant 
rabbling  of  the  charge.  The  presence  of  gangue 
renders  the  ore  less  liable  to  fuse,  so  that  the  ' 
process  is  most  easily  carried  out  with  poor 
ores,  e.g,  ore-dust,  for  the  treatment  of  which 


it  is  larsely  used.    The  furnaces  employed  are 
of  two  classes : 

(a)  Hand  rabbled  reverberatory  furnaces, 
having  an  egg-shaped  flat  bed,  with  a  fire- 
place on  either  side  and  a  working  door  at  the 
front.    With  these  the  process  is  intermittent. 

(b)  Long  bedded  rumaces,  in  which  the 
roasting  is  carried  on  continuously.  These  fur- 
naces are  40-46  feet  Ions,  by  8  feet  wide,  by  2  feet 
high,  and  have  10  worsdng  doors  on  each  sidei 
The  ore  is  charged  in  at  one  end,  and  is  then 
gradually  worked  along  the  bed  during  about 
40  hours,  and  finally  dischaiged  at  the  other 
end.  Fresh  ore  is  continually  charged  into  the 
furnace  at  the  rate  of  6  cwts.  every  8  hours. 

The  oxidation  of  the  sulphide  to  volatile 
trioxide  takes  place  at  about  400^  with  a 
carefully  regulated  amount  of  air.  This  pro- 
cess, provided  suitable  condensation  apparatus 
is  installed,  presents  marked  advantages,,  and  is 
finding  an  increasing  application,  especially  in 
dealing  with  poor  ores.  It  may  be  noted  that 
arsenic  is  completely  separated  as  the  more 
volatile  trioxide,  that  any  sold  or  silver  present 
is  left  in  the  residue  ana  can  aftorwuds  be 
extracted,  that  the  loss  of  antimony  and  the 
consumption  of  fuel  are  low.  Many  different 
forms  of  plant  have  been  used  for  this  process, 
but  in  most  the  roasting  takes  place  in  a  nunaoe 
of  cupola  type,  the  most  important  proceases 
being  the  Chatillon  and  Herrensohmidt.  The 
forms  of  condensing  apparatus  are  of  two  classes : 

(a)  In  which  the  vapours  are  passed  through 
a  series  of  flues  and  chambers  and  finally  through 
water-tanks  in  which  the  last  traces  of  oxide  are 
deposited. 

(b)  In  which  the  furnace  gases  are  cooled 
below  100°  in  flues  and  then  filtered  through 
canvas  or  other  coarse  fabric.  ' 

In  the  Herrenschmidt  process  the  roasting 
furnace  is  built  of  brick,  and  is  provided  with  a 
hopper  through  which  the  ore,  mixed  with  4-6  p.o. 
of  gas-coke  or  6-7  p.c.  chut)oal,  is  introduced. 
The  gases  pass  from  the  furnace  into  a  chamber, 
and  then  through  a  series  of  cast-iron  tubes 
placed  nearly  vertical  and  air-cooled,  in  which 
the  main  portion  of  the  trioxide  is  deposited. 
The  last  traces  are  removed  by  forcing  the  gases 
up  a  tower  filled  with  coke  over  which  water 
flows.  The  draught  is  maintained  by  two 
centrifugal  fans,  working  tandem.  It*  is  stated 
that  6  tons  of  ore,  containing  10-16  p.a  anti- 
mony, can  be  treated  in  24  hours,  with  a  yield  of 
over  90  p.c. 

Smelling  of  the  metal. — Antimony  is  prepared 
from  'crude  antimony*  or  high-grade  stibnite 
ores  by  the  *  English  '  or '  precipitation  *  method. 
The  ore,  of  which  the  composition  has  been 
determined  by  analysis,  is  ground  under  edge- 
runners  to  the  size  of  a  hazel-nut,  or  smalfer, 
and  is  subjected  to  three  operations : 

Singling.  This  process  is  carried  out  in 
crucibles  of  which  aoout  forty  are  arranged  in  a 
double  row  on  the  hearth  of  a  long  reverberatory 
furnace  having  a  grate  at  each  end,  and  a  flue, 
leading  to  condensing  chambers,  in  the  middle. 
The  crucibles  are  about  20  inches  high  and  II 
inches  across,  and  are  made  of  a  mixture  of 
0  parte  fire-clay  and  1  part  plumbago.  The 
charge  for  each  pot  is  42  lbs.  ore,  10  lbs.  iron, 
4  lbs.  salt,  and  1  lb.  slag  from  *  doubling  *  (v.t.). 
These  materials  are  introduced  into  the  red-hot 


ANTIMONY. 


357 


cracible,  and  kept  in  a  state  of  fusion  for 
2-3  hours,  at  the  end  of  which  time  the  contents 
are  poured  into  moulds,  and  the  antimony  is 
removed  from  beneath  the  slag.  The  product, 
known  as  tingles,  usually  contuns  about  91  p.o. 
antimony. 

Doubling  is  carried  out  in  crucibles  arranged 
in  a  furnace  as  previously  described.  The 
chaise  for  each  pot  is  84  lbs.  broken  singles, 
7-8  lbs.  liquated  sulphide,  and  4  lbs.  salt,  and 
the  fusion,  which  takes  about  Ij  hours,  is 
closely  watched,  the  workman  judging  from  the 
nature  of  the  slag  when  the  operation  is  complete. 
The  slag  is  then  removed  with  an  iron  ladle, 
and  the  metal  poured  into  moulds.  This  product 
is  called  bowl  metal  or  dar  howls,  and  sometimes 
contains  over  99  p.c.  antimony. 

Starring,  or  melting  for  star  metcU  (v.».  under 
Refining), 

In  the  English  process  the  loss  due  to 
slagging  and  volatilisation  is  small,  being 
only^2-5  p.o, 

it  is  possible  also  to  reduce  the  sulphide  on 
the  hearth  of  a  reverberatory  furnace.  The 
partially  roasted  ore,  which  contains  the  sulphide 
and  oxides  of  antimony,  is  mixed  and  fused  with 
8-13  p.c.  of  coal  and  9-11  p.c  of  soda,  fre- 
quently with  the  addition  of  iron,  in  which  case 
the  sla^  produced  is  much  less  fusible  and  does 
not  entirely  cover  the  bath  of  metal ;  the  anti- 
mony produced  also  contains  much  iron  (Dingl. 
poly.  J.  162,  449).  Where  carbonate  of  soda  is 
used  for  the  fusion  the  mass  froths  considerably 
and  attacks  the  furnace  hearth. 

The  metal  is  prepared  from  either  of  the 
oxides  by  One  of  the  numerous  reduction  pro- 
cesses now  in  use. 

(a)  Reduction  in  reverberatory  furnaces  is 
carried  out  at  Bouc,  Septdmes,  New  Brunswick, 
&o.  The  furnace-bed  is  ^gff-Bhaped,  deep  in 
proportion  to  its  width,  anolBiprovided  with  a 
tap-hole  at  the  lowest  point.  The  furnace  gases 
are  passed  through  a  lon^  series  of  condensing 
chambers.  First  90-110  lbs.  flux  (chiefly  salt, 
with  some  soda  and  sodium  sulphate)  and 
220-230  lbs.  of  slag  from  a  previous  operation 
are  melted  on  the  hearth,  ana  then  400^h500  lbs. 
of  roasted  ore  and  67-75  lbs.  of  charcoal  are  added, 
and  the  whole  kept  in  a  state  of  fusion  till 
reduction  is  complete.  At  New  Brunswick  the 
reduction  and  refining  are  carried  out  conse- 
secutively  in  the  same  operation. 

(6)  Some  French  smelters  reduce  an  oxidised 
ore  containing  30-40  p.o.  of  antimony  in  a 
3-tuyered  shaft  furnace  at  the  rate  of  2-2}  tons 
per  24  hours,  with  the  consumption  of  about 
half  that  weisht  of  coke.  The  regulus  contains 
92-95  p.o.  of  antimony,  and  is  subsequently 
refined. 

^  At  B&nya,  Hungary,  antimony  ores  are 
mixed  with  silidous  material  and  smelted  in  a 
blast-furnace  for  impure  regulus,  which  is  then 
refined  in  a  reverberatory  ramace.  The  blast- 
furnace used  is  a  round  stack  6  m.  high  and  1  '4  m. 
diameter  at  the  throat.  The  hearth,  which  is 
1  m.  across,  is  fitted  with  five  water- jacketed 
tuyeres,  and  has  two  outlets  for  slsc  and  metal 
respectively ;  a  third  opening  is  used  for  blowing 
out.  A  blast  of  15  cm.  per  minute  is  used,  and 
the  gases  are  collected  by  a  tube  at  the  throat 
and  passed  through  a  condensing  apparatus. 
Such  a  furnace  will  run  for  3  weeks  contmuously, 


smelting  about  20  tons  of  material  daily  (Berg, 
u.  Hutt.  Zeit.  1886,  p.  102). 

(c)  Reduction  in  crucibles  is  only  used  when 
rich  ore  or  the  trioxide  is  available.  The 
reducing  agent  for  the  trioxide  is  carbon  (char- 
coal or  anthracite),  and  sodium  sulphate  and 
carbonate  are  added  to  form  a  slag. 

Considerable  quantities  of  antimony  ore  are 
now  treated  directly  for  the  production  of  the 
metal.  One  such  process  which  has  been  success- 
fully used  for  some  time  depends  on  the  reduction 
of  the  sulphide  in  a  bath  of  molten  ferrous  sul- 
phide containing  iron  (v.  T.  C.  Sanderson,  U.S. 
Pat.  714040,  1902 ;  Cookson,  Fr.  Pat.  324864 
1902 ;  and  Herrenschmidt,  Fr.  Pat.  296200, 1900). 

Another  method  coiuusts  in  the  reduction  of 
the  sulphide  with  carbon  in  water-jacketed 
blast-furnaces.  This  has  been  used  by  Hering 
for  the  treatment  of  liquidation  residues. 

W.  R.  Schoeller  (Bull.  Inst.  Min.  and  Met. 
Feb.  1918)  describes  the  blast-furnace  smelting 
of  antimony  ores  direct  in  water-jacketed  blast 
furnaces,  the  charge  oonsiBting  of  ore,  basic 
slag,  chalk  and  coke.  In  this  method,  no  iron 
is  added  to  the  charge  and  no  reduction  of  iron 
takes  place  in  the  furnace.  The  antimony  is 
obtained  as  a  high  grade  metal,  practically  free 
from  iron.  The  oest  conditions  lor  working  the 
furnace  aie  found  to  be  about  10  p.c  coke,  low 
blast  pressure,  low  metal  cont^t  of  charge 
(about  10  p.c),  high  smelting  column  (over 
15  feet),  and  provision  of  a  heated  forehearth 
for  the  separation  of  metal  and  slag. 

Methods  of  treating  antimony  ores  have  also 
been  proposed  by  which  the  antimony  is  con- 
vertea  into  the  volatile  chloride,  as  m  Lyte*s 
process  of  roasting  the  ore  with  salt.  The  ore 
may  also  be  subjected  to  the  action  of  hydro- 
chloric acid  gas  in  a  reverberatory  or  muffle 
furnace,  the  volatilised  chloride  being  condensed 
in  a  solution  of  hydrochloric  add  (Dingl.  poly.  J. 
250,  79-88,  and  123-133). 

Among  processes  allied  to  the  smelting  of 
antimony  there  need  only  be  mentioned  that  of 
Herrenschmidt  for  the  extraction  of  gold  from 
antimony  (Fr.  Pat.  360013,  1904).  This  de- 
pends  on  the  fact  that  when  a  small  quantity 
of  antimony  is  melted  with  or  reduced  from 
auriferous  stibnite,  all  the  sold  present  in  the 
sulphide  passes  into  the  meti3. 

Many  proposals  have  been  made  for  the  ex- 
traction of  antimony  by  wet  or  electrolytic 
methods,  but  they  have  not  been  a  success 
commercially.  Reference  may  be  made  to 
Hering  (Dingl.  poly.  J.  230,  253),  and  Borchers 
(Electrolytische  Qewinnung  des  Ant.  Chem.  Zeit. 
xi.  1883,  1023). 

Refining  of  Antimony. 
Unrefined  antimony  contains  sulphur,  iron, 
arsenic,  and  sometimes  copper,  gold,  and  lead. 
The  following  analyses  show  the  composition  of 
typical  samples,  I.  and  II.  beina;  metal  made 
with  scrap  iron;  III.  and  IVT  metal  from 
roasted  ore  smelted  in  a  blast  furnace ;  V. 
Chinese  : — 

I.         n.     III.      IV.        V. 

Antimony  .  94*6  840  97  2  95*0  98*20 

Iron    .       .  30  100       25  40  0146 

Sulphur     .  20         50      0*2  0*75  0*37 

Arsenic      .  0*25       10       01  025  0-148 

Gold           .  traces  —  —  —          — 


868 


ANTIMONY. 


All  these  impurities,  except  lead,  can  be 
removed  by  slagging  with  oxidising,  sulphurising, 
or  chlorinating  agents.  The  usual  fluxes  are : 
Glauber  salt  and  charcoal,  which  remove  copper 
and  iron  as  sulphides,  and  arsenic  as  sodium 
arsenate ;  and  antimony  glass  (antimony 
oxysulphide)  which  elimmates  sulphur.  Chlor* 
ides,  such  as  salt  or  camaUite,  must  be  used 
with  caution,  or  great  loss  by  volatilisation  may 
result. 

Refining  in  crucibles  finds  its  chief  application 
in  the  English  process.  The  'star  bowls '(v.«.) 
are  cleaned  from  slag  bv  chipping  with  sharp 
hammers,  and  the  metal  is  then  broken  small 
and  melted  with  2-3  p.c.  of  antimony  flux,  pre- 
pared by  melting  together  American  potashes 
and  powdered  stibnito  in  varying  proportions 
(approximately  3  parts  potashes  and  2  parts 
stibnlte)  until,  bv  experiment,  the  correct  com- 
position is  found.  The  refining  is  carried  out 
m  the  pots  nearest  the  grates,  and  takes  30 
minutes  to  1  hour,  the  chu'ge  for  each  crucible 
being  84  lbs.  The  finished  product  is  run  into 
8-lb.  ingots,  which  arc  carefully  coveied  with 
slog  and  allowed  to  cool  without  disturbance. 
The  coal  consumption  is  large,  but  is  com- 
pensated by  a  mucn  smaller  loss  by  volatilisation 
than  occurs  in  other  processes. 

Rffining  in  reveroeratory  fumacea  is  used  at 
Milleschau,  B4nya,  Siena,  and  Oakland.  It  is 
imperative  that  the  bed  of  the  furnace  should 
be  tiffht  and  able  to  withstand  the  action  of  the 
alkab  flux,  and  this  is  best  attained  by  maldng 
it  of  one  solid  piece  of  soft,  weathered  granite. 
A  fairly  good  substitute  for  the  granite  is  a 
mixture  of  burnt  and  raw  clay  well  rammed  into 
an  iron  box.  An  example  of  such  a  process  is 
that  recommended  byHelmhacker  and  used  at 
Milleschau  (Berg.  u.  Hfltt.  Zeit.  1883,  191 ;  and 
Dinel.  poly.  J.  260,  123). 

A  '  glass  of  antimony  *  is  prepared  by  fusing 
a  mixture  of  the  crystalline  antimony  oxide 
which  coDccts  on  the  hotter  portions  of  the  flues 
with  sulphide  of  antimony,  until  it  forms  a 
glassy  dark  grey  or  brown  mass ;  this  is  mixed 
with  the  carbonate  for  the  purification  of  the 
metal,  and  is  occasionally  used  alone  where  the 
metal  is  but  slightly  impure 

The  bed  of  the  furnace  is  heated  to  a  cherry 
red  and  600  to  700  kilos,  of  crude  antimony 
placed  on  it;  a  quantity  of  oxide  and  some 
arsenic  escape,  and  in  from  30  to  60  minutes  the 
metal  has  run  down.  From  3  to  7  p.o.  (according 
to  the  purity  of  the  metal)  of  carbonate  of  soda, 
sometimes  mixed  with  coal  or  coke,  is  then  added 
The  metal  is  thus  covered  and  fumes  less,  small 
jets  of  flame  appearing  occasionally  on  its  sur- 
face ;  the  temperature  is  raised,  the  metal 
remaining  under  the  slag  for  from  1  to  3  hours 
(determined  by  the  workman),  the  slag  then 
becomes  thick,  and  is  removed  by  drawing  it 
through  the  door  with  a  long-handled  flat 
transverse  iron. 

Three  p.c.  of  antimony  sulphide  and  1)  p.c 
of  oxide  are  then  thrown  on  the  surface  of  the 
metal,  and  when  melted  4^  p.a  carbonate  of 
potash,  or  of  a  mixture  of  caroonate  of  potash 
and  soda,  are  added.  By  this  means  the  iron 
and  last  traces  of  sulphur  are  romoved;  in 
less  than  15  minutes  the  refining  is  complete,  and 
the  critical  operation  of  ladling  is  performed. 
A  cast-iron  hemispherical  ladle,  holding  15-20 


kilos.,  is  riveted  to  a  chain  hanging  from  the 
roof  exactly  in  front  of  the  workingdoor,  before 
which  the  cast-iron  moulds  for  receiving  the 
metal  are  arranged  on  a  stone  table.  The  work- 
man dips  his  lame  obliquely,  removing  some  slag 
with  the  metal ;  part  of  this  is  first  poured 
into  the  mould  to  prevent  the  metal  from 
actually  touching  the  mould,  and  the  metal  is 
well  covered  with  t^e  slag  and  left  at  vest. 
Unless  this  be  done  the  *  starring  *  will  be  im- 
perfect, and,  as  this  is  considOTed  a  test  of  purity, 
its  value  will  be  lowered  in  the  market.  The 
slag  ma^  generally  be  used  again.  The  oxide 
condensing  in  the  flues  is  remoYed  as  seldom  as 
possible,  as  this  operation,  as  well  as  the  furnace 
work,  is  very  injurious  to  the  workers. 

Star  antimony  usually  contains  small 
amounts  of  iron,  lead,  sulphur,  and  arsenic,  but 
can  be  further  purified  by  liebig's  method, 
which  consists  in  fusing  the  metal  successively 
with  12  p.c.  sodium  carbonate  and  6  p.c.  anti- 
mony sulphide,  and  again  with  sodium  carbonate 
to  which  a  little  nitro  has  been  added. 

The  following  aro  typical  analyses  of  com- 
mercial antimony  (v.  Min.  and  Sd.  Pnss, 
July  10, 1915). 

Oookson's.  Hallett'g.  Jspanese.  GbfaiAM. 

Lead        .    0*041        0*689       0*424  0*018 

Tin  .     0*035        0175        0*012  0*035 

Arsenic     .     trace        trace  0*095  0*017 

Copper     .     0*040        0*038       0*043  0*008 

Iron         .     0*010       0014       0*007  0*007 

When  'pure,'  and  cast  under  correct  con- 
ditions, a  beautiful  fern  leaf  or  *  star '  appeals 


upon  the  surface  of  antimony,  and  according  to 
the  length  and  form  of  this  star  *  on  the  insot 
its  quality  is  decided.    Although  the  '  sta^  is 


accepted  as  a  criterion  for  the  purity  of  the 
metal,  it  is  really  only  a  rough  guide.  It  is  no 
guarantee  that  the  metal  is  more  than  99  p.o. 
pure,  as  it  may  be  produced  with  inferior  metal, 
while  the  very  best  metal  may  show  an  imperfect 
star  or  none  at  all  if  not  properly  cast.  It  is 
this  peculiar  characteristic  of  pure  antimony  to 
crystalliBc  on  the  ingot  in  the  fern-leaf  or  star 
form  when  cooling,  which  originates  the  trade 
term  of  *  star  antimony.'  for  good  quality  of 
antimony. 

For  pharmaceutical  purposes  it  is  important 
to  prepare  antimony  quite  free  from  arsenia 
This  may  be  aocompUshed  by  Wohler's  method. 
A  mixture  of  4  parts  powdered  commercial 
antimony,  5  x>arts  sodium  nitrate,  and  2  parts 
sodium  carbonate  (to  prevent  the  formation 
of  insoluble  antimony  arsenate)  is  thrown  into 
a  red-hot  crucible.  Combustion  takes  place 
quietly,  the  mass  is  pressed  together  and  more 
strongly  heated  for  half  an  hour,  so  as  to  become 
pasty  without  fusion,  being  pressed  down  as  it 
rises  from  evolution  of  gas.  While  still  hot 
and  soft,  it  is  removed,  reduced  to  powder,  and 
boiled  with  frequent  stirring  in  water,  the  finer 
powder  is  poured  off  with  the  water,  and  the 
residue  again  treated,  the  washings  bein^  mixed 
with  that  first  obtained.  The  water,  which  con- 
tains the  whole  of  the  arsenic  but  no  antimony 
(Meyer),  is  removed  from  the  insoluble  portion 
by  subsidence,  decantation,  and  filtration.  The 
residue  of  sodium  antimonate  should  be  white, 
but  the  presence  of  lead  imparts  a  yellow  colour. 
It  is  driMl  and  fused  with  half  its  weight  of  cream 


ANTIMONY. 


35d 


of  tartar  at  a  moderate  heat,  cooled,  broken  into 
small  lumps,  and  the  potassium  and  aodinm 
removed  by  digestion  in  water.  The  powdered 
metal  is  then  fasod  into  a  button. 

This  method  may  be  used  quantitatively  for 
the  separation  of  antimony  from  arsenic.  If  the 
sodium  nitrate  bereplaoed  by  potassxom  nitrate, 
a  portion  of  the  antimony  will  enter  into  solu- 
tion with  the  arsenic  as  potassium  antimonate 
(p.  G.  Meyer,  Annalen,  46,  236;  Ghem.  Zentr. 
1348,  828).  Arsenic  may  also  be  completely 
removed  by  fusing  the  antimony  in  succession 
with  Ist,  potassium  carbonate ;  2nd,  potassium 
nitrate;  3rd  antimonio  oxide;  4th,  potassium 
carbonate  (Th.  Martins,  Kastn.  Arch.  24,  253), 
or  by  fusing  three  times  with  fresh  portions  of 
sodium  or  potassium  nitrate. 

Duflos  (Kastn.  Arch.  19,  66)  recommends  a 

Srocess  in  which  the  arsenic  is  driyen  off  as 
uoride  by  means  of  sulphuric  acid  and  fluorspar. 
(See  further  Schw.  42,  601 ;  also  Buchner  and 
Herberger,  Repert.  38,  381,  256.) 

Pure  antimony  may  be  obtained  by  heating 
tartar  emetic  to  low  redness  and  digesting  the 
resultant  mass  in  water  to  remoye  the  potassium. 
The  powder  thus  obtained  may  be  then  dried 
and  rased  into  a  button. 

Groschuff  (Zeitech.  anoig.  Ghem.  1918,  103, 
164)  describes  the  following  method  of  preparing 
chemically  pure  antimony.  Antimony  tri- 
chloride or  pentachloride  is  purified  by  distilla- 
tion and  conyerted  into  chloioantimonic  acid. 
The  chloride  is  dissolyed  in  concentrated  hydro- 
chloric acid,  and  chlorine  is  passed  in  until  the 
solution  becomes-. greenish -yeUow,  and  then 
hydnwen  chloride  is  mtroduced. ,  Aiter  purifica- 
tion by  reorystallisation,  the  chloroantimonic 
acid  is  hydrolysed  to  antimonic  acid,  which  is 
reduced  to  metal  by  fusion  with  potassium 
cyanide. 

Tests  for  Impuritiea  in  Aniimony. 

SvlpkuT,  The  powdered  metal  eyolyes  sul- 
phuretted hydrogen  gas  (which  blackens  lead 
paper)  on  heating  with  strong  hydrochloric 
acid. 

Arsenic,  If  deflsArated  with  }  its  weight 
of  sodium  nitrate,  boifed  with  water  and  filtered, 
the  arsenic  enters  into  solution,  leavinff  the 
antimony  behind  ;  the  solution  is  saturated  with 
sulphuretted  hydrogen  (if  an  orange  precipitate, 
consisting  of  antimony  sulphide,  falls,  this  must 
be  filters  quickly ;  it  is  oue  to  the  presence  of 
a  trace  of  antimony  in  the  solution).  The 
arsenic  is  deposited  as  the  lemon-yellow  sulphide 
on  standing. 

Lead  and  copper.  The  metal  is  powdered 
and  treated  with  dilute  nitric  acid,  eyaporated 
nearly  to  dryness,  taken  up  with  water  and 
filtered ;  the  addition  of  sulphuric  acid  precipi- 
tates white  lead  sulphate,  and  the  addition  to 
the  filtrate  of  potassium  ferrocyanide  giyes  a 
brown  precipitate  in  presence  of  copper. 

If  sulphur  as  well  as  lead  be  present  in  the 
antimony,  the  lead  is  converted  at  once  into 
sulphate  by  the  action  of  nitric  acid,  the  residue 
on  eyaporation  is  digested  with  yellow  am- 
monium sulphide,  which  dissolyes  the  antimonic 
oxide  and  leayes  black  lead  sulphide. 

Iron.  The  powdered  metal  is  ignited  with 
three  parts  nitre  and  washed  with  boiling  water, 
the  residue  is  boiled  with  hot  dilute  hydrochloric 


acid  ;  on  the  addition  of  potassium  ferrocyanide 
a  blue  precipitate  is  prociuced. 

Detection  of  antimony.  When  fused  on  char- 
coal with  potassium  cyanide  or  sodium  carbonate 
or  a  mixture  of  the  two,  antimonial  compounds 
produce  a  brittle  white  bead  of  metallic  antimony 
with  white  fumes  and  a  white  incrustation  on 
the  charcoal ;  the  bead  leayes  a  white  residue 
on  treatment  with  nitric  acid,  which  is  soluble 
in  cream  of  tartar  or  tartaric  acid.  Sulphide  of 
antimony  melts  readily  in  the  candle  fiame. 

A  delicate  confirmatory  test,  given  by 
(-rookes,  is  to  add  to  the  white  incrustation  on 
the  charcoal  one  drop  of  ammonium  sulphide, 
when  the  formation  of  the  orange  sulphide  is 
condusiye  evidence  of  the  presence  of  antimony. 

Estimation  of  aniimony. — Wet  assay. — (a) 
Oravimetric.  In  the  case  of  ores  and  products, 
a  weighed  quantity  is  fused  with  sodium 
hydrate  and  a  little  potassium  nitrate,  the 
fused  mass  Lb  extracted  with  water  and  a 
little  hydrochloric  acid  if  necessary.  The 
solution  obtained  ia  filtered,  and  if  much 
residue  remains,  it  is  re-fused.  A  few  grammes 
of  tartaric  acid  and  excess  of  oxalic  acid  are 
added,  and  hydrogen  sulphide  Ib  passed  through 
the  solution  first  cold  and  then  after  heating. 
The  sulphide  precipitate  is  filtered  off  and 
digested  with  sodium  sulphide  and  filtered. 
To  the  solution,  hydrochloric  acid  and  potassium 
chlorate  are  added,  and  it  is  boiled  until  free 
from  chlorine.  The  acidity  of  the  solution  is 
adjusted  to  50  p.c.,  hydrochloric  acid  and 
hydrogen  sulphide  passed  to  precipitate  arsenic, 
which,  if  present,  is  filtered  off.  The  solution  is 
diluted  to  three  times  its  yolume,  and  is  ready 
for  the  precipitation  of  the  antimony.  In  the 
case  of  aUoys  containing  antimony,  these  are 
dissolyed  in  hydrochloric  acid  with  the  aid  of 
potassium  chlorate  to  the  solution,  excess  of 
tartaric  acid  is  added,  and  it  is  poured  into  a 
solution  containing  soda  in  excess.  The  solution 
is  digested,  filtered,  and  the  precipitate  washed 
with  sodium  sulphide  solution.  The  filtrate  is 
acidified  with  n^drochloric  acid,  potassium 
chlorate  is  added,  it  is  then  boiled  until  free  from 
chlorine,  and  excess  of  oxalic  acid  is  added.  In 
either  case  hydrosen  sulphide  is  now  passed  into 
the  cold  solution  for  20  minutes.  Then,  without 
stopping  the  current  of  eas,  the  solution  is  heated 
to  boiling,  and  the  gas  allowed  to  pass  for  another 
15  minutes.  The  resulting  precipitate  of  sul- 
phide may  then  be  subjected  to  one  of  two 
methods  of  treatment.  It  may  be  collected 
on  a  Gooch  crucible,  washed  with  hot  dilute 
acetic  acid,  saturated  with  hydrogen  sulphide, 
and  heated  to  constant  weight  at  230^  in  a 
current  of  carbon  dioxide.  Or  the  precipitate 
may  be  collected  on  a  filter,  washed  successively 
with  hot  water,  alcohol,  equal  parts  alcohol 
and  carbon  disulphide,  alcohol,  and,  finally, 
ether,  and  then  dned.  The  greater  part  of  the 
precipitate  is  transferred  to  a  watch-glass,  and 
that  still  adhering  to  the  p^per  u  dissolved  in  a 
little  hot  ammonium  sulphiae,  and  the  solution 
allowed  to  run  into  a  weighed  porcelain  cru- 
cible. This  is  then  evaporated  to  dryness,  the 
main  portion  of  the  precipitate  added,  and  the 
whole  treated  with  fuming  nitric  acid  and 
warmed,  the  crucible  being  covered  with  a 
watch-glass.  When  the  yiolent  action  has  sub- 
sided, we  contents  of  the  crucible  are  evaporated 


360 


ANTIMONY. 


to  dtyneaa,  again  treated  with  nitrio  acid,  and 
finally  evaporated  to  dryness  and  heated  to 
redness  till  the  weight  is  constant.  The  anti- 
mony is  then  weighed  as  tetroxide. 

(h)  Volumeiric,  The  most  important  volu- 
mel^o  method  is  that  of  Mohr,  in  which  anti- 
mony tnozide  or  any  antimonious  compound 
is  dissolved  in  a  solution  of  tartaric  acid,  neutra- 
lised with  sodium  carbonate,  treated  with  a 
cold  saturated  solution  of  sodium  bicarbonate 
in  the  proportion  of  10  cc  to  each  0*1  gram 
Sb^Ot,  and  quickly  titrated  with  ilT/lO-iodine 
solution,  using  starch  as  indicator. 

(e)  EUctrdytic.  Classen  and  others  have 
shown  that  if  antimony  sulphide  {v.s.)  is  dis- 
solved in  the  minimum  amount  of  concen- 
trated solution  of  sodium  sulphide,  and  treated 
with  excess  of  sodium  sulphite,  or,  better, 
potassium  cyanide  solution  (to  destroy  poly- 
sulphides),  the  liquid  can  be  successfully  electro- 
lysed in  the  cold  with  a  current  of  0*25-0*0  amp., 
using  a  platinum  dish  as  cathode.  The  process 
takes  alK>ut  12  hours,  and  gives  a  good  coherent 
deposit  of  metal  which  can  be  washed  with 
water,  alcohol,  and  ether,  and  finally  dried  and 
weighed. 

Properties  of  Antimontf, 
Antimony  is  a  lustrous,  bluish-white  metal, 
which  has  a  coarsely  laminated  or  granular 
structure,  according  as  it  has  been  slowly  or 
quickly  cooled.  By  partial  solidification  it 
can  be  obtained  in  obtuse  rhombohedra, 
approximatini;  to  cubes. 

The  sp.ffr.  of  the  metal  is  6'72-6'86.  It 
melts  at  630*5''  C.  (Heycock  and  Neville,  Chem. 
Soo.  tirans.  1895, 186),  and  boils  at  about  1500°  G. 
in  a  current  of  hydrogen.  Antimony  has  a 
hardness  of  3-3*5,  and  is  so  brittle  that  it  can 
readily  be  powdered.  It  is  a  bad  conductor  of 
heat  and  electricity. 

The  most  important  physical  property  of 
antimony  is  that  of  expanding  on  solidification, 
a  property  possessed  also  by  its  alloys.  At 
the  ordinary  temperature  it  is  not  acted  on  by 
the  air,  but  oxidises  quickly  on  melting,  and 
bums  at  a  red  heat,  producmg  white  fumes  of 
the  trioxide.  It  is  oxidised  By  nitric  acid  of 
various  strengths,  dilute  acid  producing  princi- 
pally the  trioxide,  and  the  concentratea  acid 
TOoduoing  the  pentoxide  (H.  Rose,  Analyt. 
Chem.  1,  258).  Dilute  sulphuric  and  hydro- 
chloric acids  are  without  action  on  it,  but  the 
strong  acids  produce  the  sulphate  and  chloride 
respectively.  When  fused  with  borax  or  other 
vitrifying  material,  it  imparts  to  them  a  yellow 
colour. 

Antimony  combines  directly  with  the  halo- 
gens with  evolution  of  light  and  heat,  and  also, 
at  a  higher  temperature,  with  the  elements  of 
the  sulphur  group,  and  with  phosphorus  and 
arsenic.  The  element  occurs  in  three  modifica- 
tions :  (1)  the  crystalline  or  ordinary  form 
described  above;  (2)  an  amorphous  yellow 
modification,  soluble  in  carbon  disiUphide,  which 
is  produced  by  the  action  of  oxygen  on  liquid 
stibine  at  —90^;  and  (3)  the  amorphous  ex- 
plosive antimony,  which  is  best  prepared  by  the 
action  of  a  weak  constant  electric  current  on  a 
concentrated  acid  solution  of  antimony  tri- 
chloride, the  strength  of  current  bearing  a  con- 
stant relation  to  the  surface  of  deposition,  not 


less  than  |  grain  being  deposited  per  sq.  inch 
per  hour.  Thus  produced,  it  is  bright  and  steel 
like  in  appearance,  with  an  amorphous  fmc- 
ture  and  sp.gr.  5*78.  When  heated  to  200°, 
or  struck  or  scratched,  it  rapidly  changes  into 
the  crystalline  form,  increasing  in  density,  with 
the  production  of  great  heat.  Antimony  tri- 
chloride is  always  contained  in  the  metal  to  the 
extent  of  4*8-7*0  p.c.,  and  is  given  off  when 
the  form  changes.  It  is  probable  that  this 
substance  is  a  solid  solution  of  an  antimony 
halogen  compound  in  an  aliotropic  form  of 
antimony,  and  that  the  explosion  consists  in  the 
rapid  transformation  of  the  latter  into  the  stable 
form.  The  change  is  accompanied  by  an  evolu- 
tion of  heat  amounting  to  20  cals.  per  gram. 
Cohen  and  others  (Zeit.  physikal.  Chem.  1904, 
47,  1 ;  1905,  50,  291 ;  52,  129)  have  shown 
that  this  change  goes  on  slowly  when  explosive 
antimony  is  preserved. 

Antimony  is  precipitated  as  a  fine  powder  by 
the  action  of  zmo  on  an  acid  solution  of  an 
antimony  salt.  In  this  form  it  is  sold  as  *  iron 
black  '  for  producing  an  appearance  of  polished 
steel  on  papier  mach^,  plaster  of  Paris,  and  zinc 
ornaments. 

Brass  can  be  covered  with  a  fine  lustrous 
coating  of  antimony  by  dipping  in  a  hot  mixture 
of  I  part  tartar  emetic,  1  part  tartaric  acid,  3  or 
4  parts  powdered  antimony,  3  or  4  parts  hydro- 
chlorio  acid,  and  3  parts  water. 

It  may  be  deposited  electrolytically  on  brass 
or  copper  by  wdna  a  bath  of  the  double  chloride 
of  antimony  and  ammonia  acidulated  with 
hydrochloric  acid. 

AUays  of  Antimony. 

Antimony  alloys  with  most  of  the  heavy 
metals  and  with  the  alkali  metals.  It  dissolves 
in  a  solution  of  sodium  in  liquid  ammonia. 
It  generally  increases  Uie  fusibility,  brittleness, 
and  hardness  of  the  metals  with  which  it  is 
alloyed,  and  imparts  the  valuable  pro|)erty  of 
expanding  on  soudification,  thus  producmg  very 
fine  iznpressions.  The  sharpest  impresdons 
are  produced  when  any  of  these  alloyi  are  cast 
at  a  low  temperature  (J.  Soc.  Chem.  Ind.  1, 
982).  The  castings  are  usually  made  in  brass 
moulds  coated  with  lampblack  and  turpentine. 

With  lead,  antimony  alloys  readily  in  all 
proportions.  An  alloy  of  equal  parts  of  lead 
ana  antimony  is  very  brittle,  and  rings  when 
struck.  Nasmyth  has  recommended  thd  addi- 
tion of  5  p.c.  antimony  to  lead  for  use  instead  of 
bronze  in  taking  casts  of  works  of  art  ( Atheneum, 
No.  1176,  511). 

Type  metal  is  essentially  an  alloy  of  lead  and 
antimony,  frequently  with  addition  of  tin  and 
containing  less  frequently  copper.  A  few 
examples  of  common  type-metals  ara 

^  Lead  Antimony  Tin      Oopper 

Type  metal  .     65         30  15         —^ 

..     70  18  10  2 

.     77-5       16  6*5      — 

.     82  15  3         — 

Stereotype  plate  .     86*7       14*3      —         — 
„       .     82-5       13  4*6      — 

Linotype  metal     .84*5       13*5        2         — 
f>  »,      .     83  12  5  — 

The  alloys,  containing  varying  proportions  of 
antimony « are  also  used,  under  the  name  of  hard 
lead,  in  lead  pipes,  for  making  pumps  and  taps 


ft 


ANTIMONY. 


361 


for  raisiiu;  acid  in  alkali  works,  in  the  manu- 
facture ox  shrapnel  and  shot,  and  for  the  emery 
wheels  and  tools  of  the  lapidary. 

Tin  forms  numerous  useful  allocs  with  anti- 
mony, especially  with  the  addition  of  other 
metais.  Uommon  Britannia  meUU  contains 
tin  94,  copper  1,  antimony  5.  Britannia  metal 
for  castings :  tin  90*6,  copper  0*2,  antimony  9'2. 
The  best  Britannia  metiEd  contains  tin  90, 
antimony  10,  lead  and  bismuth  beinff  carefully 
excluded.  Copper  also  is  never  ad&d  except 
for  the  production  of  colour.  Increasing  the 
proportion  of  antimony  raises  the  m.p.,  increases 
the  hardness,  and  decreases  the  malleability  of 
the  alloy.  Good  alloys  take  a  brilliant  polish, 
and  show  a  fine-grained,  jagged  fracture.  The 
presence  of  arsenic  in  the  antimony  diminishes 
the  ductility  of  the  product. 

MekU  argenium  contains  tin  86*6,  antimony 
14-6. 

Aahbury  metal :  tin  77*8,  zinc  2 '8,  antimoxnr 
19*4.    Ships'  nails,  tin  60,  lead  33,  antimony  17. 

Minofer  is  tin  68*5,  antimony  18'2,  copper 
3 '3,  and  zinc  10. 

Bearing  or  anii-Jridion  metal  usually  contains 
antimony,  tin,  lead  and  copper,  but  the  composi- 
tion is  very  variable.  As  the  name  indicates, 
it  is  used  for  machinery  bearings,  being  especially 
suitable  for  light  loads  at  high  speeds.  As 
examples  of  these  alloys  the  foUowing  may  be 
given : — 

Antimony  Tin  Copper 
Babbit's  metal  . 
Railway  bearings 


»> 


ft 


t9 


U.S.  Rly.  Babbit  metal 
German  Rly.  Babbit 
metal    •         . 


8-3 
15 
13-5 
10 

7-4 


83*3 
8 

11*5 
61 

88*9 


8-3 

2 

3 

2 

3-7 


Lead 

76 
72 
37 


111      88-3 


6-6      — 

Copper.  The  presence  of  0*16  p.c.  of  anti- 
mony renders  copper  both  cold  and  hot  short. 
With  varying  proportions  of  the  two  metals, 
shades  from  pure  copper-red  to  rose-red,  crimson, 
and  violet  may  be  obtained,  the  last  when  equal 
parts  of  each  are  present.  Two  definite  com- 
pounds of  copper  and  antimony  appear  to  exist, 
viz.  SbCus,  a  violet  alloy  known  as  *  Rwulus  of 
Venus,'  and  SbCu4  (Kamensky,  Phil.  Mag.  [6] 
17, 270:  V.  also  Ball,  Chem.  Soc.  Trans.  1 888, 1 67). 
Antimony  is  sometimes  added  to  brass  to 
heighten  its  colour.  These  alloys  are  harder  and 
finer  in  texture  than  copper  or  brass,  and  take  a 
better  polish,  and  are  sometimes  used  for  con- 
cave mirrors. 

Zinc.  Antimony  forms-  alloys  with  zinc, 
which  decompose  water  rapidly  at  the  boiling 
temperature,  and  tlus  action  is  promoted  by  the 
presence  of  traces  of  platinic  chloride.  Cfooke 
has  su^jgested  the  suitability  of  this  reaction 
for  the  preparation  of  pure  hydrogen. 

MeUed  gold  absorbs  the  vapour  of  antimony* 
but  gives  it  up  almost  entirelv  on  further  heating. 
Gold  loses  its  malleability  when  g^Jn  of  antimony 
is  present.  An  alloy  of  9  gold  and  1  antimony 
is  white  and  very  brittle,  with  an  amorphous 
porcelain -like  fracture.  Silver  antimonide  occurs 
as  the  mineral  discrasite.  C.  0.  B. 

CoMPOXTims  OF  Antimony. 
The  principal  compounds  of  antimony  are 
formed  by  combination  with  oxygon,  sulphur, 
and  chlorine ;   some  compounds  contain  two  of 


these  negative  elements,  of  which  the  oxyohloride 
or  powder  of  Algaroih,  and  the  oxysulphide  or 
glass  of  antimony  are  examples. 

The  most  important  of  these  are  the  tri- 
chloride, trisulphide,  and  trioxide. 

Antimony  Mralphlde  Sb,S,. 

Crude  antimony,  antimony  ore,  sesquisvl- 
phide  of  antimony  ;  Schtoefdspiessglam  ;  Qrau- 
Spiessglanzerz ;  Stibium  stdphuratum  nigrum  ; 
lupus  metaUorum. 

This  substance,  as  it  occurs  naturally,  or  after 
liquation,  is  usually  too  impure  to  be  employed 
for  other  purposes  than  the  preparation  of  the 
metal. 

The  ordinary  sulphide  may  be  prepared  by 
the  following  methoois : — 

(1)  Thirteen  parts  pure  antimony  are  mixed 
with  6  parts  flowers  of  sulphur,  and  projected  in 
portions  into  a  red-hot  crucible;    when  com- 

Sletelv  fused,  it  is  poured  out  and  any  free  metal 
etacned. 

(2)  Sulphuretted  hydrogen  precipitates  it  as 
an  orange  precipitate  from  a  solution  of  an 
antimony  salt. 

(3)  Digest  for  two  hours  in  a  closed  vessel 

I  part  crude  antimony  sulphide,  1  part  pearl 
ash,  H  parts  lime,  and  16  parts  water,  and  add 
sulphuric  acid;  the  alkaline  sulpho-  salt  first 
formed  is  decomposed  by  the  acid  with  the  pre- 
cipitation of  the  pure  siUphide.  Antimony  sul- 
phide is  soluble  in  alkuine  sulphides  and  in 
acid  potassium  sulphate.  When  finely  powdered 
and  rubbed  to  a  paste  at  20**  or  30*  with  strong 
sodium  sulphide  solution,  a  coppery  metallic 
mass  is  produced,  and  the  liquor,  on  addition  of 
more  sodium  sulphide,  yields  Sohlippe's  salt. 

The  sulphide  is  used  to  some  extent  in  re- 
fining gold  from  silver  and  copper,  and  in  the 
preparation  of  safety  matches  and  percussion 
pellets  for  cartridges,  in  pyroteohny  and  in 
veterinary  suivery. 

Kermes  mmeral.  Brown-red  antimony  suU 
phide.  Pulvis  Carthusianorum,  Sulph.  «<t&fa- 
turn  rubrum, 

Kermes  mineral  usually  consists  of  a  mixture 
of  the  trisulphide  and  trioxide  containing  alkali. 
Berzelius  and  Rose  state  that  some  samples 
examined  by  them  consisted  of  a  true  double 
sulphide  of  potash  and  antimony. 

Preparation. — Fuchs  asserts  that  if  antimony 
sulphide  is  heated  and  suddenly  cooled  in  water 
it  yields  an  orange-red,  less  dense  powder  of 
kermes.  A.  Bitte  (Compt.  rend.  102,  212)  does 
not  confirm  this  statement. 

(1)  Four  parts  pure  potassium  carbonate  and 

II  parts  pure  antimony  sulphide  are  heated  to 
fusion  in  a  covered  crucible,  cooled,  boiled  with 
water,  and  filtered.  The  solution  on  exposure 
to  the  air  deposits  kermes,  the  residue  from  the 
first  boiling  is  heated  with  the  mother  liquor 
from  some  previously  deposited  kermes,  and 
yields  a  further  quantity ;  this  operation  is  re- 
peated until  an  insoluble  residue  of  trisulphide 
and  trioxide  is  left.  Each  successive  deposit  of 
the  kermes  contains  a  larger  amount  of  the  oxide. 

(2)  Fuse  together  2  parts  antimony,  1  sulphur, 
and  3  sodium  carbonate;  or,  1  antimony 
sulphide  and  3  or  4  tartaric  acid,  until  fumes 

'  cease  to  be  evolved ;  and  treat  the  product  as 
in  (1). 

(3)  The  slags  from  the  reduction  of  antimony 
!  ore   with   cream   of   tartar   slowly    precipitate 


SftS 


ANTIMONY. 


kermes  when  treated  with  water ;  this  is  sold  to 
veterinary  surgeons  as  *  kermes  by  the  dry  way/ 
When  antimony  sulphide  is  boiled  with  potash 
and  preoipitatea  with  an  acid,  the  kermes  pro- 
duced contains  no  oxide  (Liebig).  The  kermes 
produced  by  the  action  of  dUiUe  alkaline  car- 
i)onate  on  antimony  sulphide  also  contains  no 
oxide  (Rose).  The  oxide  may  be  removed  from 
ordinary  kermes  by  digestion  with  tartaric  acid. 
A  solution  containing  so  much  alkali  as  to  give 
no  precipitate  on  cooling  gives,  when  treated 
with  carbonic  acid  gas,  a  highly  sulphurated 
kermes  containing  antimony  pentasulphide. 

Kermes  is  a  brown-red,  loosely  coherent 
powder,  with  a  brown  streak,  containing  water, 
which  is  given  off  below  100®.  It  is  lighter 
than  the  ordinary  sulphide.  The  kermes  con- 
taining antimony  oxide,  when  fused  and  solidi- 
fied, is  destitute  of  crystalline  structure,  while 
that  free  from  oxide  produces  a  highly  crystalline 
solid. 

Antimony  pentasulphide  Sb,S,.    Oolden  8vi 

phide  of  aniimony  ;  diiphur  arUinumii  auralum, 

Pk«pared  by  boiling  tne  trisulphide  with  potash 
and  ground  sulphur,  filtering  and  precipitatins 
with  acid.  Redwood  recommends  4  parts  black 
antimony  sulphide,  8  lime,  and  80  water, 
digested,  filtered,  and  precipitated  with  hydro- 
cmoric  acid;  or,  2  sulphide,  4  potassium  car- 
bonate, and  1  sulphur,  to  be  fused,  treated  'witb 
20  parts  water,  filtered,  and  the  solution  pre- 
cipitated with  a  large  excess  of  sulphuric  acid. 

On  treating  the  mother  liquor  from  kermes 
mineral  with  an  acid,  the  pentasulphide  is  pre- 
cipitated with  evolution  of  sulphuretted  hydro- 
gen. The  mother  liquor  from  Schlippe's  salt 
also  yields  this  substance  on  the  addition  of  an 
acid  (R.  Bartlev,  Chem.  Soc  Trans.  187<^  I, 
748).     It  generally  contains  free  sulphur. 

Antimony  pentasulphide  is  of  some  import- 
ance commercially,  as  it  is  used  in  the  process  of 
vulcanising  rubber. 

Antimony  pentasulphide  combines  with  alka- 
line sulphides,  forming  sulphantimonates,  which 
as  well  as  the  sulphantimonites  (which  contain 
less  sulphur)  are  Imown  as  '  livers  of  antimony.* 
Of  these  the  sodium  sulphantimonate,  or 
8ehlippe*a  mU,  is  the  most  important. 

A  mixture  of  II  parts  finely  powdered  anti- 
mony trisulphide,  13  crystallised  sodium  car- 
bonate, 1  flowers  of  sulphur,  6  recently  slaked 
lime,  and  20  water,  is  digested  at  the  ordinary 
temperature  for  24  hours  with  frequent 
stirring,  in  a  vessel  ^diich  can  be  closed.  It  is 
then  strained  and  washed  several  times  with 
water,  the  solution  and  washings  are  evaporated 
in  a  porcelain  or  clean  inm  dish  until  a  sample 
yields  crystals  on  cooling ;  the  solution  is  then 
cooled,  and  the  resultant  crystals  washed  with 
cold  water  and  dried  in  the  open  air  or  in  a 
desiccator  at  the  ordinazr  temperature.  The 
salt  is  more  rapidly  formea  when  the  mixture  is 
heated  (Liebig,  Handw5rter.  d.  Chem.  2te  Aufl. 
2,  139 ;  also  Gm.  4,  384). 

Oxysulphides  of  antimony  are  formed  by  the 
combination  of  the  sulphides  and  oxides  or  by 
the  partial  oxidation  oi  the  8ulphide& 

Aniimony  crocua  or  saffron.  Fuse  together 
3  parts  of  antimony  trioxide  and  1  part  trisul- 
phide, or  fuse  the  oxide  with  the  calculated 
quantity  of  sulphur. 

The  scoria  from  the  fusion  of  the  sulphide 


with  carbon  and  alkaline  carbonate  in  the  pre- 
paration of  the  metal  is  known  as  crocus  ot 
antimony. 

Crocus  of  antimony  is  a  brownish-yellow 
body. 

Olass  of  aniimony.  Vitrum  aniimonii.  When 
antimony  sulphide  is  fused  until  the  necessary 
amount  of  sulphide  has  been  converted  into 
oxide,  the  whole  forms  a  glassy  mass  of  this 
compound.  The  best  method  of  preparation  is 
to  roast  the  sulphide  completely  into  oxide  and 
fuse  the  product  with  ^  part  of  sulphur.  Its 
colour  varies  with  the  proportion  of  sulphur 
present  from  jrellowish-rea  to  hyacinth  red.  The 
best  quality  is  of  a  fine  red  colour,  and  con- 
tains 8  antimonious  oxide  and  1  antimonious 
sulphide. 

Aniimony  cinnabar  is  an  oxysulphide  of  a 
fine  vermilion  colour,  soft  and  velvety,  and  un- 
altered by  air  or  light ;  it  is  used  in  tlie  prepara- 
tion of  ou  and  water  colours,  and  in  calico-print- 
ing. It  is  prepared  by  dissolving  antimony 
oxide  in  hydrochloric  acid,  and  placing;  the  solu- 
tion in  a  large  wooden  tub  ^ich  is  {  filled 
with  calcium  h3rpo8ulphite.  The  mixture  is 
stirred  and  heated  with  steam  to  70*,  the  pre- 
cipitate soon  subsides  as  a  yellowish  sediment 
which  changes  to  a  bright  orange-red,  and  is 
thoroughly  washed,  and  dried  below  60^  N. 
Teck  (Chem.  Zentr.  26,  1880)  prepared  it  from 
4  parts  tartar  emetic,  3  tartaric  acid,  18  water 
mixed  at  60*  with  hyposulphite  of  soda  and 
heated  to  90*(Waffner),  or  4  volumes  antimonious 
chloride  of  sp.sr.  1*19  mixed  with  10  vols,  water 
and  10  vols,  nyposulphite  of  1*19  sp.gr.,  and 
heated  ^;radually  to  55*  (Mattieu  Blessy). 

Aniimony  yeUow  {Mirim4e*s  yeUow).  Accord- 
hig  to  the  method  of  M^rim^,  a  mixture  of  3 
parte  bismuth,  24  parts  antimony  sulphide,  and 
64  parts  nitre,  is  thrown  little  by  little  into 
a  heated  crucible,  fused,  powdered,  washed*  and 
dried.  In  this  '^y  bismuth  antimonate  is  pro- 
duced. Of  this  1  part  is  mixed  with  8  parts 
ammonium  chloride  and  128  parts  litharge,  and 
fused  as  before.  The  time  occupied  and  the 
temperature  used  cause  considerable  variations 
in  tne  colour.  M^im^*s  yellow  is  a  fine  per- 
manent colour  of  ^ood  body.  It  is  only  used 
for  the  finest  painting. 

Naples  yellow  is  essentially  an  antimonate 
of  lead  containing  excess  of  lead  oxide,  but 
mixtures  of  carbonate  and  chromate  of  lead  are 
also  sold  under  the  name,  llany  prooooses  may 
be  used  for  its  preparation.  Aooooding  to 
Brunner,  a  mixture  of  1  part  tartar  emetic,  2 
parts  lead  nitrate,  and  4  parts  sodium  chloride  is 
heated,  just  to  fusion,  for  2  hours.  The  oooled 
mass  is  placed  in  water  and  soon  falls  to  pieces. 
According  to  Gulmet,  it  may  be  produced  by 
heating  a  mixture  of  1  part  potassium  antimo- 
nate and  2  parts  red  lead.  It  is  a  fine  very 
permanent  orange  or  yellow  pigment^  used  in 
oil-painting,  and,  mixed  usually  with  a  lead  gUsi^ 
for  class  and  porcelain  staining. 

Antimony  triehloride  {Butter  of  anHnumy). 

Prepared  by  dissolving  the  sulphide  in  stronjg 
hydrochloric  acid  with  a  small  quantity  of  nitrio 
acid  and  evaporating  to  dryness. 

To  prepare  the  pure  chloride,  the  acid  solu- 
tion is  evaporated  until  it  just  crystallises  on 
standing  in  a  cool  place ;  it  is  then  transferred 
to  a  retort  and  distilled  until  a  drop  of  the  dis- 


ANTINONIN. 


363 


tUlate  solidifies  oa  a  cold  surface ;  the  receivor 
is  then  changed,  and  the  further  distillate  is 
pure. 

It  is  a  white,  buttery,  semivitreous,  delique- 
scent solid.  When  pure,  it  is  crystalline,  and 
melts  sharply  at  73-2*,  and  boils  at  223-5* 
(Beckmann,  Zeitsch.  anoig.  Chem.  1006,  51, 96). 
It  is  used  as  a  caustic  in  medicine,  for  the  pre- 
paration of  tartar  emetic,  and  as  a  <  bronzhig 
solution'  for  gun-barrels,  &c.  For  this  pur- 
pose a  saturated  solution  is  mixed  with  olive  oil, 
rubbed  oyer  the  warmed  metal  and  exposed  to 
the  air  until  the  proper  colour  is  TOoduced. 
When  bronzed,  the  metal  is  polished  with  a 
burnisher  or  with  wax,  or  coated  with  a  Tarnish 
of  2  oz.  shellac,  3  drachms  dragon's  blood,  dis- 
solved in  2  quarts  of  methylated  spirit. 

Antimony  oiyehloride.  Banc  chhride^ 
powder  of  Algaroth;  ptUvis  Algarothi ;  8, 
Argelicua ;  mercunua  vUa,  dbc 

Water  is  added  to  a  solution  of  the  trichlor- 
ide until  it  is  distinctly  turbid,  when  it  is  filtered 
(the  precipitate  carries  down  any  traces  of  sul- 
phuretted hydrogen  which  may  be  present,  and 
which  if  left  would  soon  turn  the  substance 
yeUow).  Five  to  ten  volumes  of  water  are  added, 
and  the  precipitate  is  washed  with  cold  water 
and  filtered.  Its  composition  varies  with  the 
temperature  at  which  it  is  produced  and  the 
amount  of  water  used,  varying  between  SbOCl 
and,  where  a  very  larse  amount  of  water  has 
been  used,  Sb^Og.  It  is  a  white  powder,  and  is 
principally  used  for  the  preparation  of  pure 
antimonious  oxide  and  tartar  emetic. 

Antimonioiis  oilde  Sb^O..  Trioxide  of  arUu 
mony.  If  antimony  is  powdered  and  heated  in 
a  shallow  dish,  it  eventually  forms  antimony 
tetroxide  Sb^O^;  this,  toj^ether  with  the  un- 
changed metiU,  is  fused  m  a  crucible,  when 
the  tetroxide  and  antimony  react,  forming  anti- 
monious oxide,  the  excess  of  antimony  sinking 
to  the  bottom  of  the  crucible. 

For  pharmaceutical  purposes  20  parts  of  finely 
powdered  antimony  sulphide  are  gradually  added 
to  100  parts  hydrochloric  acid  containing  1  part 
nitric  acid,  and  heated,  cently  at  fint,  and 
then  more  strongly,  until  siuphuretted  hydrogen 
ceases  to  be  evolved.  It  is  then  boiled  for  an 
hour,  enough  water  is  added  to  produce  a  slight 
precipitate,  which  removes  the  last  traces  of  sul- 
phuretted hydrocen,  and  filtered  into  a  vessel 
oont&ininff  1  galfon  of  water,  precipitating  the 
oxychloriae,  which  is  filtered  and  washed  until 
it  ceases  to  have  an  acid  reaction  ;  it  has  then 
become  converted  into  the  trioxide. 

It  is*  a  white  fusible  solid,  slightly  soluble 
in  water,  volatile  at  a  red  heat.  It  becomes 
further  oxidised  to  the  tetroxide  Sb,04  on 
heating  in  air,  and  is  then  non- volatile. 

In  presence  of  alkalis  it  absorbs  oxygen; 
for  this  reason  it  has  been  proposed  to  use  it  for 
reducing  nitrobeiizene  to  anuine,  and  in  the 
preparation  of  aniline  red. 

It  is  used  for  the  preparation  of  tartar  emetic. 
When  ground  with  linseed  oil  it  is  sometimes 
used  as  a  substitute  for  white  lead,  being  less 
injurious  to  the  workmen  and  less  acted  upon  by 
sulphur  gases  ;  it  has,  however,  less  *  body '  and 
is  more  expensive. 

Tartar  emetic.  Potassium  ant%fnony  tartraU. 
Tartartu  stibiatus.  BreehweiruUin  ;  spiessglanz- 
tcevistein,    2G4H4K(SbO)Oe,H,0.    Three  parts 


antimonious  oxide  and  4  cream  of  tartar  are 
made  into  a  thin  paste  with  water  and  digeaied 
for  about  half  an  hour,  keeping  the  water  at 
constant  volume;  8  parts  of  water  are  then 
added,  boiled,  and  filtered  whilst  hot.  The 
oxychloride  or  oxysulphide  may  be  substituted 
for  the  oxide,  but  not  so  satisfactorily. 

Tartar  emetic  forms  octahedral  crystals, 
which  give  off  a  part  of  their  water  on  exposure 
to  the  air.  They  dissolve  in  14*5  parts  cold  and 
in  1*9  parts  boiling  water.  They  show  an  acid 
reaction  with  litmus,  and  have  a  nauseous 
metallic  taste,  5-10  centigrams  causing  vomiting, 
and  larger  quantities  being  very  poiionous. 

It  is  used  in  medicine  and  in  the  preparation 
of  pomades,  ftc,  and  also  largely  as  a  mordant 
in  dyeing  and  calico-printing.  Mixtures  of 
tartar  emetic  for  mordanting  are  sold  containing 
as  much  as  33-59  p.c.  zinc  sulphate  at  a  lower 
price,  under  the  names  tartar  emetic  powder, 
tartar  emetic  substitute,  antimony  mordant,  kc. 
It  is  known  that  zinc  acetate  may  partly  replace 
the  tartar  emetic  with  advantage,  but  the 
sulphate  appears  to  be  a  simple  adulterant  (H. 
Snud,  Chem.  Zeit.  1882,  ^49). 

Several  other  compounds  of  antimony  have 
been  proposed  for  mordants  instead  of  tartar 
emetic  £.  Jacquet  (DingL  poly.  J.  257,  168) 
advised  the  use  of  a  mixture  of  basic  antimony 
oxalate  with  twice  its  weight  of  ammonium 
oxalate.  Nolting  recommended  the  double 
oxalate  of  potash  or  of  ammonia  and  antimony 
(Dingl.  poly.  J.  [3]  255,  122).  It  is  stated  that 
the  latter  compounds  have  long  been  used  under 
other  names. 

The  use  of  the  fluoride  (which  is  not  pre- 
cipitated with  excess  of  water)  and  the  double 
fluorides  of  antimony  and  the  alkalis  has  been 
patented  by  S.  M'Lean.  Watson,  jun.,  patented 
a  process  for  using  trichloride  with  sufficient 
common  salt  to  prevent  the  precipitation  of  the 
oxychloride  (G.  Watson,  J.  Soc.  Chem.  Ind. 
1886,  5,  591 ;  B.  W.  Gerland,  J.  Soc.  Chem.  Ind. 
1884,  4,  643 ;  and  Kopp  and  Bru^re,  J.  Soc. 
Chem.  Ind.  1888,  566).  A  double  salt  of  anti- 
mony fluoride  and  ammonium  sulphate  SbF, 
(NH4),S04,  known  as  '  antimony  salts,'  is  also 
used  in  dyeins,  but  as  it  attacks  glass  as  well  as 
metal,  it  should  be  stored  and  worked  in  wooden 
vessels.  A  good  bath  is  100  litres  water,  400 
grams  antimony  salts,  200  grams  soda  crystals, 
at  a  temperature  of  50^  (Frey,  Bull.  Soc.  Md. 
Mulhouse,  1888,  301). 

Tartar  emetic  as  a  mordant  has,  at  the 

S resent  time,  been  largely  superseded  by  the 
ouble  oxalate  of  potassium  and  antimony,  as 
it  is  cheaper  than  the  tartrate,  and  equally 
d£cient,  although  it  contains  less  antimony. 

F.  Durinff  has  recommended  the  use  of 
the  double  lactate  of  antimony  and  calcium, 
which  can  readily  be  obtained  by  mixing, 
in  the  dry  state  or  in  solution,  alkali  lactates 
with  '  antimony  salts,*  or  other  antimonious 
compounds  (Farber,  Zeit.  [20]  319).  He  states 
that  at  least  80  p.c.  of  the  antimony  in  the 
solution  will  actually  go  into  the  cloth  as 
mordant. 

ANTIMONY  SALTS.  A  compound  of  anti- 
mony fluoride  with  ammonium  sulphate  used  as 
a  mordimt  (v.  Antimony). 

ANTINONIN.  Trade  name  for  a  solution 
of  potassium  o-dinitrocresol  used  as  a  fungicide. 


364 


ANTIPERIOSTIN. 


AMTIPERIOSTDI.  Trade  name  for  merotiry 
iodocantharidate. 

AHnPYONmUM.  Trade  name  for  sodium 
tetraborate. 

AFTIPTRni.  PJienyldimeihylpyrazohne  (v. 
Pybazolb). 

AMTIRRHINIC  ACID  v.  Digitalis. 

ANTISEPTICS  V.  DiSDrFBOTANTS. 

ANTISEPTOfE.  Said  to  be  a  mixture  of 
zino  iodide,  zino  snlphate,  boric  add,  and  thymol. 

AMTISEPTOL.  Cinehanidine  iodowJphaie, 
used  aaa  substitute  for  iodoform. 

ANTISPASMIN.  Trade  name  for  a  com- 
bination of  naroeine  and  sodium  salicylate. 
Used  as  a  narcotic  and  sedatiya 

AMTITHERMIK.  PhenylhydrazaM  of  Icewt- 
linie  add  CH,C(N,HC,H,)-CH,CH,<X),H  is 
obtained  by  dissolving  phenylhydrazine  in  dilute 
acetic  aoia,  adding  an  aqueous  solution  of  the 
equivalent  quantity  of  Isevulinic  (acetopropionic) 
acid,  and  crystallisinff  the  resulting  yellow  pre- 
cipitate from  alcohol  (Farbw.  vonn.  Meister, 
Lucius  &  Bruning  in  Hochst  a.  M.,  G.  B.  P.  Pat. 
37737). 

It  forms  oolourless,  inodorous,  and  tasteless 
scales,  melts  at  98^-99%  is  spcurinffly  soluble  in 
cold  ^ater,  soluble  in  alcohol,  ether,  or  dilute 
acids.  It  has  been  employed  as  an  antipyretic 
(Nicot,  Chem.  Zentr.  1887,  415) ;  but,  according 
to  Stark  (Chem.  and  Drug,  32,  651),  its  use  in 
medicine  is  now  almost  abandoned,  as  it  is  too 
toxic  for  use. 

AMnVENIN  V,  Snakb  Vxhom. 

AUTOZONE.  A  supDOsed  third  modification 
of  oxygen,  assumed  to  be  present  in  the  fogs 
produced  when  ozono  acts  on  reducing  agents 
such  as  sodium  bisulphite  or  hydriodic  acid. 
According  to  Rothmund  (Z.  Ekktrochem.  1917, 
23, 170),  the  phenomenon  is  due  to  the  volatile 
character  of  the  reducing  affont  and  to  be  directly 
caused  by  the  presence  of  tneee  substances  in  the 
vapour  phase.  

ANTWERP  BROWN  v.  Pigments. 

ANVULA  V.  AuLAXL 

AOOD-I-BALSAM.  Balsam  of  Mecca  (v. 
Olbokbsins). 

APATITE.  A  crystallised  mineral,  consist- 
ing of  calcium,  phosphate  in  combination  with 
fluorine,  chlorine,  hydroxyl,  or  carbonio  add, 
the  formula  being  (GaF)Ca4(P04),  or  3Ca,(P04), 
-|-CaF„  where  F  may  be  replaced  by  01,  OH,  or 
CO,.  There  are  thus  several  chemical  varieties, 
namely,  fluor-apatite,  chlor-apatite,  hydroxy- 
apatite,  carb-apatite,  and  oxy-apatite ;  the  last 
two  being  also  called  podoUte  (V.  Chirvinsky, 
1907),  and  voelckerite  (A.  F.  Rogers,  1912) 
respectively.  On  the  composition  of  these 
several  members  of  the  apatite  group,  see  papers 
b^  A.  F.  Rogers  (1914)  and  W.  T.  Schaller  (1912). 
Similarly,  by  partial  replacement  of  the  calcium, 
there  are  the  chemical  varieties  mangan-apatite, 
cupro-apatite,  and  talc-apatite.  In  addition  to 
these,  some  other  trivial  names  are  applied  to 
varieties  of  crystallised  apatite;  for  example, 
asparagus-stone,  from  Murica  in  Spain ;  moro- 
xite,  from  Arendal  in  Norway ;  and  franeolite, 
from  Wheal  Franco,  near  Tavistock  in  Devon- 
shire. The  distinction  between  fluor-apatite 
and  chlor-apatite  is,  however,  the  onlv  one  of 
any  importance.  (For  the  varieties  of  massive 
apatite,  v.  Phosphorite.) 

Apatite   is   often  found   as   well-developed 


crystals.  These  belons  to  the  hexagonal 
syvtem,  and  are  usually  oounded  by  a  six-sided 
prism  and  pyramid  witn  the  basal  plane,  though 
sometimes  numerous  other  brilliant  facets  are 
present.  The  colour  is  commonly  greenish  or 
brownish,  but  sometimes  sky-blue,  violet,  or 
colourless.  The  crystals  may  be  transparent  or 
opaque,  and  they  have  a  vitreous  to  sub-resinous 
lustre.  Sp.gr.  3*2 ;  hardness  5  (the  mineral  can 
be  Boratcnra  with  a  knife).  Owing  to  its 
variable  appearance,  apatite  is  frequently  mis- 
taken for  other  minerals,  and  it  well  deserves 
its  name,  from  iiTardof,  *to  deceive.*  In 
determining  the  mineral,  it  is  always  well  to  test 
for  phosj^horic  acid. 

As  microscopic  crystals,  apatite  is  present  as 
an  accessory  constituent  of  igneous  rocks  of  all 
kinds.  It  also  occurs  in  metamoiphic  rocks  and 
in  metalliferous  veins.  Fine  specimens  are 
found  at  many  localitiee,  but  only  in  two 
regions — ^in  Norway  and  Canada — ^is  crystallised 
apatite  mined  for  commercial  purposes.  In 
southern  Norway,  particularly  in  tne  neighbour- 
hood of  Kragerb  and  Oedeeaarden,  near  Bande» 
extensive  deposits  of  chlor-apatite  occur  in 
connection  with  |;abbro  (a  pyroxene-felspar  rock 
of  i^eous  oiigm).  Large  deposits  of  fluor- 
apatite  are  mined  in  Ottawa  Co.,  Quebec,  and 
in  Renfrew  Co.,  Ontario ;  here  the  mineral  forms 
beds  in  Laurentian  gneiss,  usually  in  association 
with  crystalline  limestone.  In  the  iron  mines 
at  MineviUe,  in  Essex  Co.,  New  York,  small 
grains  of  apatite  occur  disseminated  in  magnetite, 
sometimes  to  the  extent  of  5  p.c.  of  the  mass. 
Here  it  is  separated  by  a  magnetic  process,  and 
used  for  the  manufacture  of  fertilizers. 

On  the  Norwegian  deposits,  see  J.  H.  L. 
Vogt,  Die  Apatit-Ganggruppe,  Zeits.  prakt. 
Qeol.  1895,  iu,  367,  444,^65.  On  the  CanadUn 
deposits,  the  various  publications  of  the  Canadian 
Geolo|^cal  Survey.  See  also  0.  Stutzer,  Die 
wiohtigsten  Lagerstiltten  der  '  Nicht-Erze,* 
Berlin,  1911,  i.  L.  J.  S. 

APERITOL.  A  mixture  of  equal  parts  of 
valerianyl  and  acetylphenolphthalein,  used  as  a 
laxative. 

APHTHFTALITE.  Native  sulphate  of  po- 
tassium and  sodium,  (K,Na)sS04,  containing 
K :  Na  in  ratios  vaiying  from  3  : 1  to  4  :  3.  It 
occurs  sparingly  as  crusts  and  delicate  platy 
crystallisations  on  Vesuvian  lava;  these  are 
colourless,  or  often  tineed  with  blue  or  ^reen. 
The  crvstals  are  rhomoohedral  and  optically 
uniaxial,  although  often  simulating  ortho- 
rhombic  forms;  and  are  dimorphous  with  the 
usual  orthorhombic  modification  of  potassium 
sulphate  obtained  artificially.  The  same  mineral 
has  been  found  at  Rocalmuto,  Sicily,  and  in  the 
potash-salt  deposits  at  Douglashall,  near 
Westeregcln,  in  Prussia.  Synonyms  are  arcanite 
andglaserite.  L.  J.  S. 

APHTHITE.  An  alloy  containing  800  parts 
of  copper,  25  of  platinum,  10  of  tungsten,  and 
170  of  ffold  (Zeite.  f.  d.  C.  Grossgew.  4,  313). 

APIOENIN  v.  Flavonb. 

APIIN.  A  glucoside  contained  in  parsley  and 
celery,  forming  on  hydrolysis  apigenin  and  a 
disaccharide,  made  up  of  a-glucoee  and  a  pentose, 
ajnose  (Vongerichten,  Anmden,  1901,  121),  (v. 
Flavonb  and  Glucosides). 

APIOL  t'.  Oils,  Essential. 

APIOSE  V.  Cabbohydrates. 


APPLE. 


366 


API08  TUBEROflA  (Moench.),  Cflifcine 
apioa  (Linn.).  A  leguminotis  plant  from 
North  America,  the  roots  of  which  have  heen 
proposed  as  a  substitute  for  thepotato,  and  the 

Toung  seeds  for  peas.  Payen  (Compt.  rend.  28, 
89)  gives  the  following  analysis  of  the  root: 
Nitrogenous  matters,  4*6;  fatty  matters,  0'8; 
staroh,  sugar,  &o.,  33*66;  cellulose,  &c.,  1-3 ; 
inorganic,  2*26  ;  water,  67*8  (cf,  Brighetti,  Chem. 
Zentr.  1900,  i.  9U). 

APIUH  V.  Oils,  Essential. 

APIUM  PETROSELINUM  (Carum  petro- 
sdinum)  v.  FlJlVonii. 

APOGTNUM  V.  Digitalis. 

APOLLO  RED  v.  Azo-  coLOUBoro  hattsbs. 

APOLTSIN.  Trade  name  for  monopheneti- 
dine  citrate:  antipyretic  and  analgesic. 

APOMORPHINE  v.  Opium. 

APONAL.  Trade  name  for  amy  carba- 
mate. 

APOPHOROMETER,  THE  (Sublimation 
apparatus).    The  apophorometer  consists  essen- 


tially of  a  ribbon  of  thin  platinum,  about 
6  cm.  long  and  4  or  6  mm.  ¥ride,  stretched 
between  two  forceps.  A,  B,  provided  with 
binding  screws  so  that  an  electric  current  can 
be  sent  through  the  platinum.  One  of  the 
foroepe  is  movable,  and  is  acted  upon  by  a 
light  spring  so  as  to  keep  the  ribbon  stretched. 
Beneaw  the  ribbon  is  a  watch-elass,  0,  held  on  a 
support  which  can  be  raised  or  lowered  or  turned 
to  one  side.  From  6  to  30  mgrms.  of  the  sub- 
stance under  examination  are  spread  on  the 
ribbon,  the  watch-glass  is  moved  upwards  into 
contact  with  the  ribbon  and  then  a  second 
inverted  watch-glass,  D,  is  placed  over  the  first 
one  as  a  cover.  A  current  is  now  passed  throueh 
the  ribbon  and  gradually  increased  until  the 
sublimation  temperature  is  attained.  The 
temperature  can  be  estimated  with  fair  accuracy 
by  means  of  an  amperemeter.  The  whole 
apparatus  may  be  placed  under  a  bdl-jar,  if  it 
be  desired  to  work  %n  vacud  or  in  an  atmosphere 
of  an  inert  gas.  When  necessary  strips  of  thicker 
platinum  or  moulded  strips  of  carbon  may  be 
used  instead  of  the  thm  platinum  ribbon. 
Sublimation  experiments  with  this  apparatus 
may  with  advantage  be  used  instead  of  blow- 
pipe tests  for  the  identification  of  minerals,  and 
details  of  experiments  made  with  various 
minerals  are  nven  (Joly,  Phil.  Mag.  1913,  25. 
301 ;  J.  Soc.  Ghem.  Lidl  1913,  32,  500). 
APOPHTLUTE  v.  Calcium. 


APOREINE.  A  poisonous  alkaloid  found  in 
the  juice  of  Papaver  dubium,  m.p.  88^-89**. 
Forms  crystalline  salts,  giving  a  bluish  fluor- 
escence in  solution.    The  hydrochloride 

C,«Hi^O„Ha, 

forms  silvery  nacreous  scales,  subliming  without 
decomposition  in  dry  carbon  dioxide  between 
220*^  and  240^.  The  neutral  (normal)  sulphate 
melts  at  70^-76^  and  when  exposed  to  air  and 
light,  decomposes,  forming  a  reddish-brown 
powder  (Pavesi,  <^azz.  chim.  ital.  1014,  44, 
398). 

APORETIN  V.  Rhubabb. 

APOTHESINE.  Trade  name  for  the  cinnamic 
ester  of  diethyl  amino  propyl  alcohol.  Used  as 
a  local  anseathetic.     V.  ANiESTHBTios. 

APOTURMERIC  ACID  v.  Tubmbbio. 

APPALLAGIN.  Trade  name  for  a  mercury 
compound  of  tetraiodophenolphthalien. 

APPERTOL.  Trade  name  for  a  preparation 
of  sodium  bisulphite.  Used  as  a  preservative 
and  disinfectant. 

APPLE.  The  fruit  of  Pyrus  Malua  (Linn.). 
Many  varieties  are  known,  differing  greatly  in 
size,  shape,  colour,  and  flavour. 

The  solid  matter  of  apples  consists  laigelv  of 
sugars — ^IsBvulose,  sucrose  and  dextrose;  their 
acidity  is  due  to  malic  acid  C,H«0(COOH),. 
In  unripe  apples  staroh  is  present---4ometime6 
to  the  extent  of  4  or  6  p.o.,  but  the  fully  ripened 
fruit  is  devoid  of  starch.  Oellulose  forms  about 
1  p.c.  of  the  weight  of  the  ripe  fruit,  pentosans 
about  0*6  p.c.,  and  pectose  matters  also  about 
0*6  p.c.  {cf.  Schneider,  Analyst,  1912,  492). 
Mineral  matter  is  usually  between  0*2  and  0'3  p.c, 
and  about  half  of  this  is  potash.  Apple  peel 
contains  small  quantities  of  waxes,  similar  to 
bees- wax. 

The  following  analyses  of  American  Baldwin 
apples  show  the  changes  which  occur  during 
npemng: — 


Very 
green 

Qreen 

Bipe 

Over- 
ripe 

Water 

81-33 

79-81 

80-36 

80-30 

Solids 

18-67 

20-19 

19-64 

19-70 

Eteduoing  sugars  . 

6-40 

6*46 

7-70 

8-81 

Oane  sugar . 

1-63 

4-06 

6-81 

6*26 

Starch 

4*14 

3-67 

0-17 

none 

Free  malic  acid    . 

114 

— 

0-66 

0-48 

Ash    . 

0-27 

— 

0-27 

0-28 

Hotter  (Chem.  Zentr.  1900,  ii.  484)  gives  the 
following  analysis  of  apple  ash  : — 


KiO 
51-68 


CaO 
4*22 


MgO 
3-71 


FetOj 
1-18 


SiO. 
1-08 


SOj 
2-49 


P,0. 
10-42 


Certain  varieties  of  apples — ^particularly 
those  used  for  cider-making — are  rich  in  tannin, 
and,  when  the  cells  are  broken,  €.7.  by  cutting 
the  apple  or  by  a  bruise,  so  as  to  admit  air,  a 
browning  takes  place — probably  by  the  action 
of  an  oxydase  upon  the  tannin. 

Otto  (Bied.  Zentr.  1901,  ii.  663 ,-  and  1902, 
31,  107)  found  that  the  percentage  of  water 
increases  during  ripening  on  the  tree,  but  di- 
minishes on  storing,  that  the  starch  diminishes 
and  finally  disappears,  while  the  cellulose 
remains  constant.  The  nitrogen  increases  during 
ripening  on  the  tree,  but  afterwards  diminishes. 


366 


APPLE. 


The  acidity  diminiahes  daring  ripeniiig,  both 
before  and  after  gathering. 

The  following  figures  relate  to  South-Afncan 
apples  (Ingle).  The  flesh  and  rind  of  the  ripe 
friiit,  the  core  and  pips  being  rejected,  con- 
tained:— 


Variety 

Koo 

Bel- 

nette 

Nor- 
thern 

Vers- 
feld 

TKird 
Wolte- 

Caaada 

spy 

^^0mnm 

ley 

Water     . 

86-08 

_ 

82-64 

87-66 

84-41 

DiT  matter 
Ash 

14-92 

.— 

17-36 

12-36 

16-59 

0-313 

— 

0-262 

0-270 

0-268 

Acidity         (as 

malic  acid)  . 

0-47 

0-66 

0-48 

0-71 

0-47 

Reducing  sugars 

7-44 

6-87 

10-26 

9-43 

10-85 

Cane  sugar 

4-63 

3-68 

4-77 

1-36 

1-68 

Nitrogen 

0-046 

0094 

0-068 

0-067 

0-043 

Crude  fibre 

1-33 

1*24 

1-26 

•— 

0-88 

Per  cent,  in  ash: 

Potash 

54*48 

— 

48-62 

63-30 

61-68 

Lime  . 

2-63 

^■■iw 

1-95 

1-82 

2-70 

Silica  . 

1-61 



1-58 

1-26 

0-90 

Phosphorus 

nentoxide. 
Sulphur    tri- 

1M5 

•— 

1210 

8-09 

1216 

oxide 

2-46 

2-67 

313 

3-10 

Chlorine 

0-fiO 

^^■^ 

0-89 

1-02 

1-00 

The  proportions  of  lime  found  in  these  apples 
are  apparently  lower  than  those  usually  found 
in  American  apples,  while  the  figures  for  phos- 
phorus pentoxide  and  chlorine  are  higher. 

Under  normal  conditions,  the  starch  present 
in  unripe  apples  is  converted,  during  ripening, 
into  sugar  by  the  diastase  present,  but  if  the 
unripe  apples  be  bruised,  this  change  is  incom- 
plete in  the  bruised  portion,  and  starch  may  be 
found  in  the  browned  tissues.  According  to 
WarcoUier  (Compt.  rend.  1906,  141,  406),  this 
is  due  to  the  paralysing  effect  upon  the  duistase 
of  the  tannin  which  escapes  from  the  bruised 
cells  (and  which,  by  the  action  of  an  oipydase, 
gives  rise  to  the  browning),  thus  preventing  the 
sacchaiification  of  the  starch,  upon  which 
normal  ripening  depends. 

According  to  Eoff  (J.  Ind.  £ng.  Chem.  1917, 
9,  687),  the  preponderant  sugar,  in  all  the  twenty 
varieties  examined,  was  Isevulose.  This  con- 
firms the  observations  of  Thompson  and 
Whittier  (BuU.  102,  1913,  Delaware  Coll.  Agric. 
Expt.  Stat.),  and  of  Browne  (A.  1902,  ii. 
371). 

Apples  are  now  dri.d  by  artificial  heat  (with 
or  witnout  the  use  of  sulphur  dioxide,  which 
improves  the  colour),  and  sold,  either  as  whole 
frmt  or  as  *  apple  rings.*  Fresh  apples  yield 
about  one-seventh  of  their  weight  of  the  dried 
product.  Zinc  is  frequently  found  in  dried 
apples,  probably  from  contact  with  zinc  trays 
during  the  diymg  process.  As  much  as  0*68 
gram  Zn  per  kilogram  has  been  found  in  Ameri- 
can dried  apples.  American  analyses  give  as 
the  average  components  of  dried  apples :  36  p.c. 
water,  I'i  p.c.  protein,  3*0  p.c.  ether  extract, 
67*6  p.c.  carbohydrates,  and  1*8  p.c.  ash.  The 
flavour,  and  particularly  the  odour,  of  apples 
can  be  imitated  by  Mo-amyl-t^so- valerate  dissolved 
in  spirits  of  wine.    This  constitutes  the  '  essence 


of    apples  *    used    in  confectionery   and   per- 
fumerv. 

H.  L 
APPLES,  ESSENCE  0F»  v.  Apflw. 
APPLE-PULP  (pomace)  forms  a  by-product 
of  cider  manufacture,  and  has  the  following 
composition  (8  samples) :  Water  (p.o.)  68'4-78-l 
fat  (ether  extract),  0'82-r43;  prot^  1-03- 
1-82;  crude  fibre,  4*42-10*6;  a£,  0*66-2*27; 
carbohydrates  (sugar,  &o.),  9'6-22'0.  Most 
stock  eat  it  readily,  and  it  is  a  satiafaotoiy 
feeding  stuff  if  given  as  an  adjunct  to  moro 
concentrated  foods.  It  must  be  given  .fresh, 
for  it  undergoes  fermentation  and  putrefaction 
00  rapidly  as  to  be  unfit  for  consumption  in  two 
or  three  days  in  warm  weather.  When  dried  it 
may  be  used  in  the  manufacture  of  compound 
cakes  and  poultry  feeds.  If  mixed  with  salt 
it  may  be  preserved  if  tightiy  pressed  in  a  silo. 
It  usually  contains  from  0*2-0*6  p.c.  of  potash, 
0*4  to  0*7  p.0.  phosphoric  add,  and  1*6  to  1*7  p.c. 
nitrogen,  and  makes  an  exc^ent  manure,  if 
mixed  with  half  its  weight  of  lime  to  neutrsJise 
adds  (Barker  and  Ginungham,  Journal  of  the 
Board    of    Agriculture,    1915,  22,    861).    See 

CSlDXB. 

APPLE  TREE.  {Pyrtu  nuOus,  L. ;  Pomme^ 
IV. ;  Apfd,  Qer.)  The  wood  is  much  used  in 
turnery,  and  that  of  the  crab  tree  is  used  by 
millwrights  for  the  teeth  of  mortice  wheels. 
The  bark  contains  a  tannin  identical  with  that- 
contained  in  horse-chestnut  bark. 

APRICOT.    The  fruit  of  Prunns  armeniaea 
(Linn.). 

The    following    analyses    were 
Fresenius : — 

I. 
Medium 
Bize 
Sugnrs    .  .1-14 

I  Free  acid  .  .  0-90 
Nitrogenous  matter.  0-83 
Pectins,  gum,  &o.  .  5*93 
Ash  .  .  .  0-82 
Total  soluble  matter  — 9-62 

I  Seeds  (stone)         . 
Skin  and  cellulose 
Pectose 
Ash      .         .         .(0-07) 

Total  insoluble   matter,  ex-j q.^2 6-16 


4  30 
0-97 
0-15 


made    by 

n. 

Large 
wt.  60  grams. 
1-53 

0-77 
0-39 
9  28 
0-75 

— 12-72 

3-22 

0-94 

1-00 

(010) 


eluding  ash 
Water 


84-96      82-12 


100-00    100-00 

In  Calif omian-grown  apricots,  Colby  (Exp. 
Stat.  Record,  1893,  4,  91 8}  found  in  the  whole 
fresh  fruit,  water,  86-16;  dry   matter,  14-84; 
containing  nitrogen,  0-194;  sugar,  11*10;  ash, 
0-49. 

The  ash  was  found  to  contain : 
KsO    K»20     CaO    MgO  MnOs  F20j      S0«      SIOj 
59-36  10-26  317  3-68    037  13-09    3-63    6-23 


CI 
0-45 


Fe^Os 
1-68 


Califomian  apricots  appear  to  contain  more 
nitrogen  than  tne  £uro]^n  fruit.  As  many 
other  analyses  agree  in  giving  about  11  p.c.  of 
sugar,  it  ib  probable  that  some  error  has  been 
made  in  Fresenius'  figures,  though  they  have 
been  widely  quoted. 

The  sugar  is  chiefly  sucrose,  with  a  little 
dextrose,  and  invert  sugar,  which  becomes  less 


ARAGHI3  OIL. 


967 


when  the  fniit  npens  (Desmooli^re,  Ann.  Chim. 
moaL  1902,  7,  323).  The  colouring  matter  is 
probably  related  to  caiotin. 

The  acidity  of  apnoota  is  dhiefly  due  to  malio 
and  citric  acids.  i 

Hie  kernels  of  apricot  *  pits,*  or  stones,  like  | 
those  of  the  other  members  of  the  Ptmrnrnt 
f amily,  oontain  am j^(dalin  and  about  40  p.a  of ' 
a  fatty  ofl  reeembbng  almond  oiL     This  oil 
has  a  8p.gr.  of  0-9204  at  16-6*,  a  pale-yellow  colour, , 
and  a  uight  odour  of  almonds  (Maben,  Fhann.  J. ' 
l^ans.  [3]  16,  797).    More  recent  determinations ' 
give  the  following  (Dieterich,  CSiem.  Zentr.  1902, 
2  [15],  943) :  sp-gr.  at  WV,  0-915-O-921,  at  90*, 
0-9010-0-9016;  solidifying  point.  -14*to  --20^ 
saponificatioo  value,  193*1-215-1 ;  iodine  value 
(Hiihl),  100-108-7 ;  refraotometer  value  at  26*, 
65-6-67-0;  at40*,68-0;  at60*,62-26.  Itoanbe 
distinguished  from  almond  oil  by  Biber's  reagent 
(fumins  nitric  acid,  sulphuric  acid  and  water), 
with  wnich  it  gives  a  red  oolonry  while  almond 
oil  only  yields  a  faint  yellow. 

The  flavour  of  apricots  can  be  imitated  by 
a  mixture  of  woamyl  butyrate  and  Moamyl 
aloohoL 

Dried  apricots  are  prepared  eitiier  by  sun- 
drying  or  by  artificial  heat,  sulphur  <iiozide 
bong  often  employed  in  the  latter  case,  in  order 
to  prevent  darkening  in  colour.  The  v  are  largely 
used  in  America  and  in  some  of  the  colonies. 
American  analyses  show  them  to  contain  about 
32  p.c  of  water,  63  p.c.  of  carbohydrates,  2-9  p.o» 
of  nitrogenous  matter,  and  1-4  p.c.  of  ash. 

H.L 

AFRIOOT,  ISSENCB  OF.  A  mixture  of 
iioamyl  bu^rate  and  woamyl  alcohoL 

APRIOOT  KERNEL  OIL  v.  Apbicot. 

APTBON.  Trade  name  for  Utbium  acetyl- 
salicylate. 

AQUA  FORTES  v.  Nitbio  acid. 

AQUAREGIA.  Nitromuriatic  add ;  K&nigs* 
toasser.  A  name  given  by  the  alchemists  to 
a  mixture  of  nitric  and  hydrochloric  acids, 
originally  prepared  by  dissolving  sal  ammoniac 
in  strong  nitric  acid,  and  used  by  them  as  a 
solvent  for  gold,  sulphur,  dtc.  Usually  made 
by  mixing  1  vol.  of  nitric  acid  with  4  vob.  of 
hydrochloric  acid.  The  mixture  is  at  first 
colourless,  but  gradually— eeoeoially  on  heating 
— acquires  a  deep  orange-yeUow  colour,  due  to 
the  formation  of  nitrosyl  chloride  and  free 
chlorine :  HNO,+3HCl=NOa-|-a,+2H,0. 
The  solvsnt  action  of  aqua  regia  appears  to  be 
mainlv  due  to  the  free  chlorine. 

AQUA  VIT AE.  An  alchemistio  name  used  to 
denote  common  alcohol  as  obtained  by  <^i<rf.niing 
a  liquid  which  has  undergone  vinous  fermenta- 
tion. 

ARABIC  GUM  v.  Oums. 

ARABINOSE  v.  Cabbohydratxs. 

ARACHIDIC  ACm  CH,(CH,)|,G00H  is 
found  partly  free  and  partly  as  a  glyceride  in 
earth-nut  ou  (from  Araaiis  hypzgcea  (Linn.)) ;  in 
butter,  and  in  the  fruit  of  Nephelium  lappaceitm 
(Heintz.  Pogg.  90,  146;  Grossmann,  Annalen, 
89, 1 :  Oudemans,  Zeits.  f.  Chem.  1867, 256).  It 
has  been  prepared  by  treating  behenolio  acid 
CssH^oO,  with  fuming  nitric  acid  (Grossmann, 
Ber.  1893,  644),  and  synthetically  from  aceto- 
acetic  ester  and  octodeoyl  iodide  (Sohweizer. 
Arch.  Fharm.  1884,  753) :  m.p.  77*"  (Baczewski, 
Monatsh.     17,    530).    Solubility    in    90    p.o. 


alcohol,  0-022  p.e.  at  15%  and  0-046  p.0. 
at20^ 

The  methyl  ester  melts  at  64*6®,  and  the 
ethyl  ester  at  60®,  and  boils  at  284®-286®  under 
100  m.m.  pressure. 

ARACHINE  C,HuON^  an  alkaloid  occuiriitf 
with  choline  and  betaine  in  earth-nut  (nounf 
nut,  monkey-nut)  meal  {Araekis  kypogea  (linn.)). 
Syrup ;  the  auriohloride  and  platinirhloride  are 
oryBtalline.  Produces  somnolence  in  frogs  and 
rabbits  (Mooeer,  Landw.  Versuch-Stat.  1904,  60, 
321). 

ARAGHIS  OIL  is  obtained  from  the  seeds  of 
AraehU  hypogaa  (Linn.),  which  are  known  in 
commerce  as  earth  nuts,  pea  nuts,  or  monkey 
nuts.  The  cultivation  of  the  arachis  plant  dates 
back  so  far  in  history  that  its  origin  is  unknown. 
It  is  frequently  assumed  that  the  home  of  the 
arachis  nut  is  Brazil.  The  plant  is  chiefly 
cultivated  in  the  East  Indies,  Indo-(}hina,  Java, 
Japan,  the  West  Coast  of  Africa,  Mozambique, 
Madagascar,  ^ypt,  Spain,  Sicily,  the  United 
States  of  America,  the  Aigentiii^  and  in  the 
West  Indian  Islands.  The  East  Indian  and 
West  African  nuts  represent  two  distinct 
varieties.  In  commerce  a  distinction  is  made 
between  decorticated  and  non-decorticated  nuts. 
The  Indian  and  Moaambtque  nuts  are  usually 
decorticated  before  they  are  shipped  to  Europe ; 
as  they  undergo  some  detrimental  changes  on 
the  voyage,  they  cannot  be  used  for  the  |tfoduo- 
tion  of  Mst  edible  oil,  and  are  mostly  worked 
up  for  soap  oil.  The  nuts  coming  from  West 
Axrica  mostly  arrive  non-decorticated,  and  are 
therefore  suitable  for  the  preparation  of  best 
edible  oil,  the  lower  qualities  only,  derived  from 
a  second  and  third  expression  {see  below)  being 
used  for  technical  purposes.  The  approximate 
composition  of  arachis  nut,  taking  tne  average 
of  nuts  from  various  places  of  origin,  is  as 
follows  :  oil,  38-60  p.c  ;  water,  4-6-12'8  p.o. ; 
albuminoids,  26-31  p.c  ;  carbohydrates,  6-19 
p.o. ;  fibre,  ri-4'1  p.o. ;   ash,  1-6-3*0  p.o. 

The  undecortioated  nuts  are  shelled  by 
special  machinery  and  the  inner  red  skin  which 
surrounds  the  kernel  is  removed  as  completely  as 
possible  by  a  blast  of  air.  The  separated  and 
cleaned  kernels  are  then  ground  in  the  usual 
manner  and  subjected  to  hydraulic  pressure. 
As  the  kernels  contain  so  hish  a  proportion  of 
oil,  the  expression  of  the  ou  is  carried  out  in 
two  stages;  frequently  the  meal  is  even  ex- 
pressed three  times.  The  first  expression 
takes  place  at  the  ordinary  temperature,  and 
yields  the  'cold-drawn'  oU;    the  second  ex- 

Sression  is  carried  out  at  a  temperature  of  30**- 
2'' ;   and  the  third  expression  at  50''-55^ 

The  'cold-drawn*  oil  is  nearly  colourless, 
and  has  a  pleasant  taste,  recalling  that  of 
kidney  beans ;  it  is  used  as  salad  oil,  and  sold 
under  the  name  '  huile  surfine.*  The  oil 
obtained  by  the  next  expression  also  serves  for 
edible  purposes,  in  the  sardine  and  margarine 
industnes,  or  for  burning ;  the  lowest  quality, 
which  has  been  expressed  at  the  highest  tempera- 
ture, is  chi^y  used  for  soap-maung. 

The  arachis  cakes  serve  as  an  excellent 
cattle  food,  for  they  contain  the  highest  amount 
of  proteins  of  all  known  oil  cakes ;  moreover, 
these  proteins  are  more  easily  digested  than 
those  of  other  cakes. 

Their  average  composition  is :   water,  1 1*5 ; 


308 


ARACHIS  OIL. 


fat,    8*8;     cellulose,     &o.,    311;     ash.    7*25; 
proteins,  41*35 :  nitrogen,  6 '8  p.c.  (Soh&dler). 

On  standing  a  few  degrees  above  freezing- 
point,  '  stearine  *  deposito  from  arachis  ou. 
This  stearine  contains  (xrachin,  which  does  not 
settle  oat  as  a  crvstallina  mass,  so  that  it  cannot 
be  removed  in  tne  usual  manner  by  expression. 
Hence  it  is  necessary,  in  order  to  *  demargari- 
nate*  arachis  oil,  to  allow  it  to  stand  for  a 

Srolonged  time  in  the*  cold,  when  *  margarine 
'arachide  *  settles  out,  so  that  the  supernatant 
clear  oil  can  be  drawn  ofif. 

Amongst  the  solid  fatty  acids  of  arachis  oil, 
arachidio  acid  and  lignooerio  add  have  been 
identified,  l^ese  two  acids  are  characteristic 
of  arachis  oil,  and  as  their  proportion  can  be 
determined  quantitatively,  the  separation  and 
determination  of  '  crude  arachidio  acid  *  (t.e. 
a  mixture  of  arachidic  and  lignoceric  adds) 
furnishes  an  excellent  means  of  identifying 
arachis  oil,  and  estimating  its  proportion  in 
mixtures  with  other  oils.  Amongst  the  liquid 
f attv  adds  of  arachis  oil,  oldc  acid  undoubtedly 
preaominates ;  in  addition  to  it  linoHc  acid  has 
Deen  identified,  but  the  presence  of  hypogseic 
acid  is  doubtful,  the  only  oxidation  compound 
obtained  from  the  liquid,  fatty  adds  being  a 
sativio  acid  (KUmont  and  Mayer,  Monateh. 
Chem.  1Q13,  34,  1195).  Stearic  acid  ^oes  not 
appear  to  be  present ;  the  fatt^  acid,  m.p.  68^ 
separated  by  Hehner  and  Mitchell  (Analyst, 
1898,  21,  238),  consisting  of  a  mixture  of 
litf^ooerio  and  arachidic  adds  (Klimont  and 
Mayer,  l.c). 

The  sp.gr.  of  arachis  oil  is  usually  about 
0*917-0*919  at  15°,  but  Sadtler  (Amer.  J.  Pharm. 
1897,  69,  490)  obtained  as  low  a  value  as  0*911 
with  oil  froifl*  African  nuts,  whilst  the  oils  from 
Indian  nuts  have  ffiven  values  of  0*9223  to 
0*9266  (Groesley  and  Le  Sueur,  J.  Soc.  Chem. 
Ind.,  1898,  17,  989).'  The  usual  limits  for  the 
iodine  value  lie  between  87  and  100,  but  ex- 
tremes of  84*4  (Schnell)  and  105  (Oliveri)  are 
on  record.  For  its  detection  and  estimation,  «ee 
Evers,  Analyst,  1912,  37,  487.  As  the  iodine 
value  of  arachis  oil  lies  so  near  that  of  olive  oil, 
adulteration  of  olive  oil  with  araehis  oil  takes 
place  on  the  largest  scale ;  indeed,  very  fre- 
quently arachis  oil  is  entirely  sube^ituted  for 
olive  oil  (as  in  the  preparation  of  tinned  sar- 
dines). 

It  is  also  a  common  adulterant  of  castor  oil 
when  used  as  a  lubricant  for  aeroplane  motors. 
Its  presence  may  be  detected  by  the  turbidity 
temperature  of  an  alcoholic  solution  of  the  oil, 
pure  castor  oil  solutions  remaining  clear  below 
— 20°,  whilst  1  p.c.  of  arachis  oQ  causes  the 
liquid  to  become  turbid  at  a  much  higher 
temperature.  Arachis  oil  itself  is  liable  to  be 
aduRerated  with  sesame  oil,  which  is  added 
partly  with  the  object  of  preventing  solidifica- 
tion when  the  oil  is  exposed  to  a  moderatdy 
low  temperature.  The  addition  may  be  de- 
tected by  the  Baudouin  test  (see  Sbsa.me 
Oil). 

Arachis  oil  is  chiefly  expressed  in  the  South 
of  Europe  (Marseilles  and  Trieste) ;  therefore 
the  lower  qualities  of  this  oU  enter  largely  into 
the  composition  of  the  soaps  of  South  Europe. 
Thus,  one  of  the  most  characteristic  component 
of  the  Marseilles  white  eoap  is  arachis  oil.  The 
quantity  of  arachis  nuts  imported  into  France 


during  the  year  1907  was :  arachis  nuts  in 
shells,  163,241  tons  ;  decorticated  arachis  nuts, 
117,404  tons.  The  total  quantity  of  arachis 
nutis  produced  in  the  world  may  be  taken  to 
amount  to  about  350,000  tons.  In  1910, 
6,686,679  tons  of  oil  seeds  were  imported  into 
Marseilles,  of  which  34,800  tons  were  arachis 
nuts.  Next  to  France,  arachis  nuts  are  largely 
imported  into  Trieste,  Delft,  and  in  sm^ter 
quantities  to  Germany  (about  25,000  tons),  and 
to  the  United  States  of  America.  The  latter 
country  produces  about  50,000  tons  per  annum. 
The  imports  of  arachis  oil  into  Italy  increased 
from  470  tons  in  1908  to  5080  tons  in  1910 
(Molinari).  J.  L. 

ARAGONITE.  The  orthorhombic  form  of 
calcium  carbonate  (CaCO,),  differing  from  the 
more  common  dimorphous  form  calcite  {q.v.)  in 
its  greater  density  (sp.gr.  2*93),  greater  hardness 


(H.  31),  and  in  the  absence  of  cleavage.  It 
crystallises,  together  with  calcite,  from  aqueous 
solutions  containing  carbon  dioxide  at  tempera- 


tures above  18°,  and  the  presence  of  various  salts 
in  the  solution  favours  its  growth.  In  nature 
it  is  deposited  by  thermal  springs,  for  instance, 
those  01  Carlsbad  in  Bohemia,  in  the  form  of 
pea-like  concretions,  this  variety  of  the  mineral 
beinff  known  as  pisoUU,  Another  variety, 
called  floi-ferri  (flower  of  iron),  is  found  as 
snow-white  coralloidal  forms  in  the  iron  mines 
of  Stvria.  Crystals  were  first  found  embedded 
in  red  clay  ana  gypsum  in  Aragon,  Spain ;  and 
divemnt  groups  of  spear-like  crjrstals  have  been 
found  in  an  iron  (haematite)  mine  in  west 
Cumberland.  Fine  groups  of  twinned  prismatic 
crystals  are  met  with  in  the  sulphur  mmes  near 
Giigenti  in  Sicily,  and  in  the  copper  mines  at 
Herrongrund  in  Hungary.  A  vanety  containing 
about  5  p.o.  of  lead  carbonate  is  called  tamo- 
witzite  from  its  occurrence  at  Tamowitz  in 
Silesia.  L.  J.  S. 

ARALIA  BARK  or  False  PriMy  Ash  Bark, 
the  bark  of  ArcUia  spinosa  (Linn.),  contains  a 
volatile  oil,  an  amorphous  bitter  substance, 
(tannin),  a  grey  acrid  reeiiif  and  a  glucomde  to 
which  the  name  etralein  has  been  given  (Lilly, 
Pharm.  J.  [3]  13,  305).  By  boiling  aralein  with 
dilute  hydrochloric  acid,  aralir^in  is  obtained 
(Holden,  Pharm.  J.  [3]  11,  210;  Chem.  Soc. 
Trans.  40,  105). 

ARAROBA  POWDER  v.  Chbtsabobih. 

ARASOfA  GURGI.  An  impure  gamboge 
from  Camara,  obtained  probably  from  a  species 
of  Garoinia  (Dymock,  Pharm.  J.  [3]  7, 
451). 

ARBOL-A-BREA  RESOf  is  obtained  from 
Canarium  Ituonieum  (Miq.),  a  tree  belonging  to 
the  Burseraces,  growing  in  the  Philippines. 
The  resin  is  greyish-yellow,  soft,  glutmous, 
and  has  a  strong  asreeable  odour.  It  contains 
61*29  parts  of  resm  very  soluble  in  alcohol; 
25*00  parts  of  resin  sparingly  soluble  in  alcohol ; 
0*25  essential  oil ;  0*52  free  acid ;  0*52  bitter 
extractive  matter;  6*42  woody  and  earthy 
impurities  (Bonastre,  Jour.  Pharm.  10,  129). 
Baup  has  isolated  four  crystalline  subetanoes, 
Amyririf  Breidin,  Brein,  and  BrycHdine  (Ann. 
Chim.  Phys.  [3]  31,  108). 

ARBUTIN  V.  Glucosidxs. 

ARCHIBROMIN.  Trade  name  for  mono- 
bromottfovaleryl  glyoolylurea. 


ARCHIL. 


869 


hSCREL  or  ORCHIL  {OraeiUe,  Fr. ;  OrseiUe, 
Ger. ;  Oricetto,  It.)  appears  in  oommeroe  in  three 
fomiB :  (1)  as  a  pasty  matter  called  archU ;  (2) 
as  a  mass  of  a  drier  character,  named  j)€rais ; 
and  (3)  as  a  reddish  powder  called  cudbear.  It 
is  obtained  from  various  lichens  of  the  genus 
Roceella,  growing;  on  the  rocky  coasts  of  the 
Azores,  ike  Canaries  and  Cape  de  Verd  Isles,  also 
of  the  Cape  of  Good  Hope,  Madeira,  Corsica, 
Sardinia,  &c.,  and  from  OchroUchia  tartar^, 
growing  in  Sweden  and  Norway.  None  of  these 
lichens  contains  the  colouring  matters  ready 
formed,  but  there  are  present  certain  colourless 
acids  of  the  type  of  Ueanoric  actd,  deriyatives 
of  OTcin,  into  which  they  can  be  readily  con- 
verted. Thus,  leoanoric  acid  (1)  gives  first 
orseUinlc  acid  (2)  and  subsequently  orcin  (3) 
aocording  to  the  following  scheme : — 

CH, 

cooh/\         ho/\oh 

CH,  . 


(2) 


CH, 

cooh/\ 
ohI^oh 


(3)  Ho/\oH 
CH, 


Orcin  itself,  when  acted  upon  by  air  and 
ammonia,  changes  into  a  purple  substance  ciJled 
orcein,  which  is  the  name  appued  to  the  colouring 
matters  of  archil  (Robiquet,  Ann.  Chim.  Phys., 
[2J  47.  238). 

Finely  powdered  ordn  is  placed  in  a  thin 
layer  under  a  bell  jar,  together  with  a  beaker 
oontainins  strong  anunoma  solution.  As  soon 
as  the  BUDstance  has  become  brown  coloured, 
it  is  removed  and  exposed  to  air  for  some  time. 
It  is  then  dissolvea  in  very  dilute  ammonia 
solution,  reprecipitated  with  acetic  acid,  and 
dried.  According  to  Gerluurdt  and  Laurent, 
orcein  has  the  composition  Ci4H7NOe  (Ann. 
Chim.  Phys.,  [3]  24,  315),  but  more  recent  re- 
searches indicate  that  it  is  a  mixture  of  sub- 
stances. Liebermann,  for  instance  (Ber.  7, 
247 ;  8,  1640),  considers  that  by  this  reaction 
three  colouring  matters  are  produced,  having 
respectively  the  formule  (a)  C,4Hi,N04 ; 
(6)C,,H,X0,;   and  (c)  CuH„N,0,. 

Zulkowski  and  Peters  (Monatsh.  11,  227) 
allowed  orcin  to  remain  in  contact  with  am- 
monia for  two  months,  and  from  the  product 
isolated  three  substances : — 

(a)  Bed  orcein  C^iHu^fiy,  the  main  pro- 
duct, which  appean  to  be  formed  according  to 
the  following  equation  : — 

4C,HgO,+2NH,-f60=C,«H,4N,07+7H,0 

It  is  a  brown  crystalline  powder,  soluble  in 
alcohol  with  a  red  colour,  and  in  alkaline  solu- 
tions with  a  blue-violet  tint. 

(6)  A  crystalline  yellow  compound, 

C.,H.^O.. 

which  is  accounted  for  as  follows : — 

3C;H.O,+NH,+30=C,|H„NO,+4H,0 
Vol.  I.— r. 


(c)  An  amorphous  product  similar  to  litmus. 

These  substances  can  be  prepared  much  more 
rapidly  by  the  addition  of  hydrogen  peroxide 
to  an  ammoniacal  solution  of  oroin. 

There  can  be  no  doubt  that  this  reaction 
proceeds  in  several  stages,  and  that  the  character 
of  the  product  varies  according  to  the  duration 
of  the  process.  This  is  well  known  to  manu- 
facturera,  who  can  prepare  at  will  a  blue  or  a 
red  orchU.  The  constitution  of  these  colouring 
matters  has  not  -yet  been  determined,  but  in 
view  of  the  cireumstances  by  which  they  are 
produced,  it  is  most  probable  that  they  are 
members  either  of  the  oxazine  or  ooDozonc 
groups. 

Orohil  was  originally  prepared  from  the 
lichens  by  means  of  stale  urine,  which  sunplied 
the  necessary  ammonia,  but  ammonia  solution 
is  now  exclusively  employed.  The  older  methods 
have,  however,  been  greatly  improved,  and  in  the 

£laoe  of  barrds  the  operation  is  carried  out  in 
irge  horizontal  or  vertical  cylinders  fitted  with 
stirrers,  and  suitable  openings  for  the  admission 
of  sir. 

In  such  an  apparatus  the  weed  is  digested 
with  about  three  times  its  weight  of  ammonia 
solution  at  60°  for  from  three  days  to  one  week, 
the  admission  of  air  being  regulated  according 
to  the  judgment  of  the  manufacturer.  The  first 
product  of  the  reaction  has  a  blue  colour,  and 
if  the  process  be  stopped  at  this  point,  there  is 
formed  the  dyewaro  known  as  blue  orchil.  On 
the  other  hand,  if  the  action  of  the  air  and 
ammonia  is  allowed  to  proceed  further,  red  orchil 
is  obtained.  These  orehil  pastes  when  dried 
and  finely  ground  constitute  the  product  known 
as  cu^ear, 

Bedford  (D.  R.  P.  67612,  1880)  blows  air  or 
oxygen  through  the  ammoniacal  mixture,  which^ 
especially  in  the  latter  case,  materially  shortens 
the  process.  The  apparatus  employed  is  erected 
vertically,  and  by  an  ingenious  arrangement  of 

S rejecting  shelves,  the  edges  of  which  are  turned 
own,  a  considerable  quantity  of  the  air  or 
oxygen  is  entrapped,  and  exerts  therefore  a  more 
powerful  oxidismp  e£fect. 

Orchil  liquor  is  prepared  by  extracting  the 
lichens  with  boiling  water,  concentrating  the 
extract  to  from  8°  to  10°  Tw.,  and  submitting 
this  to  the  action  of  air  and  ammonia ;  whereas 
orchil  extract  is  produced  by  the  extraction  of 
orohil  paste  itself. 

In  former  times  archil  and  cudbear  were 
frequently  adulterated  with  magenta,  certain 
azo  colours,  extracts  of  logwood,  brazilwood,  &c. ; 
but  as  the  importance  of  these  dyestuffs  has 
now  very  greatly  diminished,  such  a  contamina- 
tion is  at  the  present  time  of  rare  occurrence. 

Arehil  and  its  preparations  are  substcmtive 
colouring  matters,  which  dye  well  in  a  neutral 
bath,  but  have  the  useful  property  of  behaving 
nearly  as  well  under  slightly  acid  or  slightly 
alkalme  conditions.  Even  colours  of  con- 
siderable intensity  are  produced  from  it  without 
difficulty,  but  unfortunately  these  are  not  fast 
to  light.  Wool  is  dyed  in  a  neutral  bath,  or 
with  addition  of  a  trace  of  sulphuric  acid,  and 
silk  is  dyed  in  the  presence  of  soap  solution, 
acetic  acid  being  sometimes  added.  Arohil  is 
not  applied  to  cotton. 

Archil  was  at  one  time  employed  to  a  large 
extent  for  '  bottoming  *  indigo,  that  is  to   say, 

2  B 


870 


ARCHIL. 


the  fabric  was  first  dyed  with  archil  and  subse- 
quently with  indiffo.  The  reverse  process, 
known  as  *  topping/ has  again  been  considerably 
in  vogue.  Cudbear  and  archil  are  also  used  to  a 
limited  extent  in  conjunction  with  other  dye- 
stuffs  for  the  production  of  compound  shades. 
White  wines  are  sometimes  coloured  with 
archil,  but  its  presence  can  be  detected  by  pre- 
cipitating with  lead  acetate  and  extracting  with 
amyl  alcohol,  when  a  red  colour  indicates  the 
presence  of  archil  or  map;enta.  The  addition 
of  a  little  hydrochloric  acid  changes  the  colour 
to  yellow  if  magenta  be  present,  but  does  not 
alter  it  if  archil  is  the  adulterant  (Haas,  Zeitsch. 
anal.  Chem.  20»  869;  J.  Soa  Chem.  Ind. 
1,  119). 

A.  G.  P. 

ARCHIL  REDS  v,  Azo-  coloubinq  mattxbs. 

ARCHIL  SUBSTITUTES  t;.  Azo-  coloubing 

ICATTBBS. 

ARCHIODIN.  Trade  name  for  monoiodo- 
Movalerylglycolylurea. 

ARDENNITE.  A  mineral  consisting  of 
vanadio-silicate  of  aluminium  and  manganese, 
HioMn8Al8V,Si,04«  or  H,oMnicAlioV,Si,oOj6, 
containing  0"63-9*20  p.c.  VgOj.  The  vanadium 
is  partly  replaced  by  arsenic  (up  to  9*33  p.c. 
As^Os),  and  in  these  varieties  the  colour  is  paler. 
It  has  as  yet  been  found  only  at  Salm-Ch&teaux, 
near  Ottrez,  in  the  Belgian  Ardennes,  where  it 
occurs  embedded  in  quartz  veins  in  phyllites  or 
slaty  schists.  It  forms  yellow  to  brown  aggre- 
gates of  bladed  or  columnar  crystals ;  these  are 
orthorhombic  with  a  perfect  cleavage  parallel 
to    the    brachypinacoid,  and    good    cleavages 

Parallel  to  the  unit  prism.  Sp.gr.  3*58-3*66 ; 
ardness,  6-7.  It  is  readily  fusible  with 
intumescence  before  the  blowpipe  to  a  black 
glass ;  and  is  not  attacked  by  hydrochloric  and 
nitric  acids,  though  slightly  by  sulphuric 
acid. 

L.  J.  S. 

ARECA  NUT,  Betd  nvi,  is  the  seed  of  the 
areca  palm,  Areca  CcUechu,  Linn.,  a  native  of 
the  Sunda  Islands,  cultivated  in  tropical  India 
and  the  Philippines.  It  is  often  chewed  in  the 
Far  East  togeuier  with  lime  and  the  leaves  of 
betel  pepper,  and  is  also  used  as  a  vermifuge. 
In  America  and  Europe  it  is  used  in  veterinary 
practice,  against  tape  worm.  Arecoline  hydro- 
bromide,  m.p.  170°,  IS  employed  for  this  purpose, 
and  is  official  in  the  German  Pharmacopoeia. 
The  nuts  contain  six  alkaloids,  all  more  or  less 
closely    related :     Arecoline,    CgHigO^N,    the 

Erincipal  alkaloid  (0*1  p.c.)  is  a  strongly  alkaline 
quid,  b.p.  220°,  and  highly  toxic  (Meier, 
Biochem.  Zeit.  1907,  2,  416).  It  is  the  methyl 
ester  of  Arecaidine  C7H„0,N,H,0,  m.p.  222*^- 
223°,  which  is  non-toxic  and  identical  with 
A*-tetrahydronicotinio  acid 


r%xx  ^x-'^Hj— — CH' 

^*^»\U*Me— CH,- 


^CCOOH 


synthesised  by  Wohl  and  Johnson  (Ber.  1907, 
40,  4712).  Ouvacine  CoHaOjN,  m.p.  271-272°, 
is  a  lo'A'er  homologue  in  which  the  N-methyl  is 
replaced  by  hydrogen,  is  a  totrahydroMonicotinic 
acid  (probably  A') 

^^\ch*ch'^^'^^^" 


a/recaint,  m.p.  231^,  is  N-methyl  gnvacine,  and 
hence  the  last  two  are  both  crystalline  solids 
of  neutral  reaction.  Quvacoline .  is  guvacine 
methvl  ether,  b.p.  114713  mm.,  and  an  alkaline 
liquid  which  cxystallises.  For  the  constitution 
of  these  alkaloids,  mostly  discovered  by  Jahns 
(Ber.  1888,  21,  3404),  for  the  properties  of  their 
salts  and  for  earlier  references,  see  Freudenberg 
(Ber.  1918,  51,  1668),  who  thinks  that  perhaps 
only  arecoline  and  guvacoline  oscur  as  such  in 
the  nuts,  and  sho^s  that  arecaine  of  Jahns 
is  identical  with  arecaidine.  Arecolidine, 
CgH,,0,N,  m.p.  110°,  isomeric  with  arecoline, 
occurs  in  minute  quantitv  in  the  mother  liquors 
of  technical  arecoline  hydrobromide,  and  is 
probably  3  :  4-dimethoinr  1 -methyl,  1 :  2-di- 
hydropyridine  (Emde,  Apoth.  Zeit.  1915,  30 
240).  G.  B. 

ARBCAHNE,  ARBCADINE,  ARECOUDINB, 

ARECOLINE  v.  Abbca  Nttt. 

AREOMETER  v.  Htdbometbb. 

ARGAL  V.  Arool. 

AROALDDf.  A  combination  of  albumin- 
silver  and  hexamethylenetetramine. 

ARGAN  OIL.  An  oil  obtained  from  the 
kernels  of  Argahia  Sideroxylon  (Boem.  et  Schult) 
(ord.  SapotacecB),  growing  in  Morocoo.  The 
kernels  are  first  roasted,  ground  to  powder  and 
mixed  with  water,  when  the  oil  aqiarates 
(Pharm.  J.  [3]  10,  127). 

ARGENTAHIN.  Trade  name  for  ethylene- 
diamine  silver  nitrate. 

ARGENTAN  v,  Aluuinium  and  Nickel. 

ARGENTINE.  A  name  given  by  R.  Kirwan 
in  1794  to  a  variety  of  oalcite  (CaCO|)  occurring 
as  small  scales  with  a  pearly  white  or  silvery 
lustre. 

ARGENTINE.  Finely  divided  spongy  tin, 
made  by  reducing  a  weak  solution  of  tin  salt 
(120  grams  in  60  litres  of  water)  by  zinc.  The 
tin  is  collected  in  a  sieve,  washed  with  water, 
and  dried  at  a  gentle  heat.  Used  for  tin-plating 
and  also  for  printing  upon  fabrics  and  paper 
(Deut.  Ind.  Zeit.  23,  255 ;  J.  Soc.  Chem.  Ind. 
7,604). 

ARGENTITE.  A  mineral  consiflting  of  silver 
sulphide  Ag,S,  and  occurring  as  cubic  crrotals 
or  as  compact  masses.  It  is  blackish  lead-grey 
in  colour,  and  perfectly  sectile  ,*  surfaces  cut 
with  a  koife  are  oright  and  shining.  Sp.Rr.  7*3. 
Containing  87*1  p.c.  of  silver,  it  is  a  valuskble  ore 
of  the  metal  when  met  with  in  quantity,  as  in  the 
Comstock  lode  in  Nevada  and  in  Mexico. 

L.  J.  S. 

ARGENTOL.  A  synthetic  antiseptic,  con- 
sisting of  a  compound  of  silver  with  quinosol, 
of  the  formula  C»HsN(OH)SO,-Ag.  Forms  a 
yellowish  powder,  of  a  faint  smell,  sparingly 
soluble  in  water  and  alcohol  (Pharm.  Zeit.  1897, 
42,  243). 

ARGENTORAT.  Trade  name  for  a  flash- 
powder  consisting  of  a  mixture  of  potassinm 
perchlorate  and  aluminium,  used  in  photo- 
graphy :   gives   very   little   smoke   (t;.    Flash - 

POWDERS). 

ARGINASE.  An  enzyme  occurring  in  the 
liver,  also  present  in  the  kidney,  the  intestinal 
mucous  membrane,  thymus,  and  other  organs 
(Kossel   and    Dakin,   Zeitsch.    ph3r8iol.    Chem. 


ARGININE. 


371 


1904,  41,  321).  aementi  (Atti.  R.  Aooad. 
Linoei,  1014,  [v.]  23,  H.  612,  and  ibid,  1916,  25, 1, 
366)  finds  it  in  the  Iddney  c^  mammalB  and  in  the 
liyer  of  mammalB,  ampnibia  and  fishee,  but  not 
in  that  of  birds  or  reptiles ;  eee  also  Edlbacher 
(Zeitsch.  physiol.  Ghem.  1916,  95,  81-87 ;  ibid, 
1917,  100,  111);  Shiga  found  it  (Zeitsch. 
phyaiol.  Chem.  1904, 42, 502)  among  the  enzymes 
obtained  from  yeast.  It  is  also  found  in  various 
plants  (Kizel,  Bull.  Acad.  SoL  Petrograd,  1915, 
1337-64).  It  can  be  extracted  from  the  liver 
by  water  or  dilute  acetic  acid,  and  is  precipitated 
from  solution  by  alcohol,  ether,  or  ammonium 
sulphate.  Awinase  is  a  speoifio  enzyme  for  the 
exclusive  hycuolysis  of  a-aiginine  or  of  sub- 
stances containing  the  ei-arginine  grouping, 
which  it  converts  almost  quantitatively  into 
carbamide  and  (2-omithine.  For  the  detection 
of  aiginase,  v.  CSementi  (Atti  B.  Accad.  Uncei, 
1917,  [▼•]  26,  L  261).  Creatine  and  other 
goanddine  derivatives  structurally  similar  to 
aiginine,  or  guanidine  itself,  are  incapable  of 
hydrolysiB  by  tlus  enzyme  (Dakin,  J.  Biol.  Chem. 
1907,  3,  436 ;  and  Clementi  (Atti  R.  Accad. 
Linoei,  1915,  [v.]  24,  i.  483-489). 

The  action  of  arginase  on  aiginine  may  be 
followed  by  titration  of  the  arginine  solution 
(in  presence  of  formaldehyde)  with  N/5  sodium 
hydroxide  solution,  Clementi  (Atti  K.  Accad. 
linoei,  1914,  [v.]  23,  ii.  617-523);  see  also 
S5iensen  (Biochem.  Zeitsch.  1907,  7,  45-101). 
M.  A.W. 

ARGINIHE  CtHuOaN^,  a-amino'9-guanino' 
n-volene  octet  NH  :C(NH|)*NH(CH,),'CH(NH,)- 
CO^H,  first  isolated  by  Schulze  and  Steiger 
(Ber.  1886,  19,  1177)  from  the  etiolated  germi- 
nated  cotyledons  of  LupimUf  is  the  most  widely 
distributed  dissociation  product  of  proteid 
matter,  and  can  be  obtained  by  hydrofysis  of 
the  proteid  matter  of  seeds  of  Lupinua  luteus, 
CueurhUa  pepo,  Picea  esocelsa,  to  the  extent  of 
10  p.c.,  Abies  peetinaiOt  Pinus  sylvestris,  and 
other  conifers  (Schubce,  Ber.  1891,  24,  276; 
Zeitsch.  physiol.  Chem.  1896, 22, 411, 435 ;  1897, 
24,  276).  According  to  Suzuki  (Chem.  Zeit. 
1899,  23,  658)  the  arginine  obtained  from  the 
seeds  of  conifers  exists  already  formed,  but  in 
loose  combination  with  the  proteid  material,  and 
is  also  i^roduced  syntheticaUy  in  the  plant  from 
ammonium  salts  and  nitrates,  either  in  full  or 
diffused  daylight  (BuU.  Coll.  Agr.  Tokyo  Imp. 
Univ.  1900,  4,  25).  It  ia  found  in  a  number  of 
plants,  generally  in  company  with  asparisine, 
less  often  with  ^lutamine,  and  also  when  neither 
is  present  (Stieger,  Zeitsch.  physiol.  Chem. 
1913,  86,  268;  Schulze,  U,  81,  53).  It  is 
found  in  soil  (Schieiner  and  Shorey,  J.  Biol. 
Chem.  1910,  8,  381 ;  Schreiner,  Lathrop, 
J.  Amer.  Chem.  Soc.  34,  1242),  and  in  the  blood 
under  normal  conditions  (Abderhalden,  Zeitsch. 
physiol.  Chem.  1913,  88,  478).  For  presence 
of  arginine  in  hops,  see  Chapman  (Chem.  Soc. 
Trans.  1914,  105,  1899).  According  to  Skinner 
(Bied.  Zentr.  1913,  42,  213,  from  Proc.  8th 
Intemat.  Congress  Applied  Chem.  1912)  it  is 
produced  in  soil  as  a  primary  cleavase  product 
of  proteids  and  can  take  the  plade  of  nitrate  in 
the  soU.  Arginine  is  also  one  of  the  constituents 
of  the  product  of  hydrolysis  of  proteids  of 
animal  origin,  thus,  horn  yields  2'25  p.c. ;  glue, 
2*60  p.c. ;  conglutin,  2*75  p.c. ;  albumen  from 
yolk  of  egg,   2*3    p.c. ;    from    white    of    egg. 


0*8  p.c. ;  blood  serum,  0*7  p.o. ;  and 
casein,  0*25  p.c.  (Hedin,  ZeitecL  physiol. 
Chem.  1894,  20,  186),  whilst  the  protamines 
Salmine,  Sturine,  Clwpeine,  ScombrinSt  C^dopte- 
riney  and  Crenilahrine  yield  aiginine  as  the 
chief  product  of  hydrolysis  (Kossel,  Zeitsch. 
physiol,  Chem.  1896,  22,  176 ;  1898,  25,  165 ; 
1899,  26,  688 ;  1904,  40,  565 ;  1910,  69,  138). 
In  cases  of  phosphorus-poiBoning  aiginine  is 
found  in  the  urine  (Wohlgemuth,  Zeitsch. 
physiol.  Chem.  1905,  44,  74),  whilst  the 
amount  obtained  from  the  liver  is  diminished 
(Wakeman,  Zeitsch.  physiol.  Chem.  1908,  44, 
335). 

The  cleavage  of  arginine  in  plants  and  animals 
due  to  enzyme  action  is  identical  with  tiiat  which 
occurs  in  putrefactive  processes :  ornithine  and 
carbamide  are  produced  (Kossel  and  Dakin, 
Zeitsch.  physiol.  Chem.  1904,  41,  321 ;  1904, 
42,  181 ;  Ackermann,  ibid,  1908,  56,  305 ; 
Kiesel,  ibid,  1912,  75, 170, 196.) 

When  arginine  is  heated  with  barium 
hydroxide  it  is  decomposed  into  ammonia, 
carbamide,  and  omithine  {q,v.)  {aZ-diaminovalerie 
acid) ;  cyanamide  reacts  with  omithine  at  the 
ordinanr  temperature  to  form  arffinine  (Schulze 
and  Wmterstein,  Zeitsch.  physiol.  Chem.  1898, 
26,  1;  Ber.  1899,  32,  3191),  or  with  a-ben* 
zoylomithine  to  form  the  benzoyl  derivative 
of  arp^inine,  and  this  is  readily  hydrolysed  to 
aiginme,  which  is  thus  proved  to  be  a'amino- 
B-guanino-n-valerie  acid  (Sorensen,  Ber.  1910, 
43, 643  ;  «ee  also  Zeitsch.  physiol.  Chem.  1911-12, 
76,  94). 

Arginine  yields  a  copper  compound 

Cu(C.HuO,N4), 

Kober  and  Sugiura  (J.  Biol.  Chem.  1912-13, 
13,  5). 

Arginine  crystallises  in  brilliant  monodinio 
plates  (Haushofer,  Zeitsch.  phyi^ol.  Chem. 
1887,  11,  53);  m.p.  207°-207-5°  (Gulewitz, 
Zeitsch.  physiol.  Chem.  1899,  27,  178) ;  it  also 
crystallises  with  1H,0  in  rhombohedn  (Hedin, 
Zeitsch.  physiol.  Chem.  1895,  21,  160) ;  it  dis^^ 
solves  readily  in  water,  and  is  sparingly  soluble 
in  alcohol.  Arginine  contains  an  asymmetric 
carbon  atom,  and  the  dextrorotatory  form  is 
the  natural  product,  the  hydrochloride  has 
[a]D+12'5^  in  aqueous  or  +25*5°  in  hydrochloric 
acid  solution.  Arginine  is  strongly  alkaline, 
and  its  solution  absorbs  carbon  dioxide  from 
the  air;  it  forms  wdil-defined  cr3r6talline  salts 
with  acids,  and  compounds  with  certain  metallic 
salts  (Gulewitz,  <.e.).  The  nilrtUe  C«Hi40,N4, 
HNO„itH,0  has  m.p.  126°;  the  dtniirtUe 
OsHuOaN^^HNO,  has  m.p.  151° ;  the  hydra- 
chloride  C«Hi«0aN4,HC13i0  melts  and  decom- 
poses at  209°  when  anhydrous;  the  (iZ-auri- 
chloride  CeHi40,N4,2HCl,Aua„lH,0  has 
m.p.  105°- 11 5°;  the  d-arginine  aurichloride 
C.Hi40tN4,2HAuCl,,liHjO  softens  at  140° 
and  melts  at  160  (Weiss,  Zeitsch.  physioL 
Chem.  1911,  72,  490) ;  the  silver  nitnUe  com- 
pounds C4Ht40,N4,AgNO„iH,0  decomposes 
at  164°,  and  CcH,40,N4,AgNO„HNO,  melts 
and  decomposes  at  180° ;  the  cupric  nitnUe 
compound  2C«Hi40,N4,Cu(NO,)„3H,0  melts 
at  112°-114°  or  decomposes  at  232°-234° 
when  anhydrous;  the  copper  sulphate  com- 
pound   melts    at     110°    or   decomposes    when 


372 


ARGININE. 


anhydrous  at  236*~238'* ;  the  picraie  CfiifiJ^i* 
C«H,0^„2H,0,  m.p.  206°,  dissolves  in  2041 
parts  of  water  at  1 6° ;  the  pierolonaU  C eH  1 4O ,N4, 
C,oH805N4,H,0,  m.p.  ^ZV,  dissolves  in  1124 
parts  of  water,  or  2885  parts  of  alcohol  at  the 
ordinary  temperature  (Schulze  and  Steiger, 
Ber.  1886,  19,  1177;  Hedin,  Zeitsch.  phyaiol. 
Chem.  1894,  20,  186 ;  Oulewitz,  ibid.  1899,  27, 
178  ;  Steudel,  ibid,  1903,  37,  219  ;  Reiaser,  ibid. 
1906,  49,  210).  The  auriohloride  of  a  tetra- 
methyl  arginine 

C,oH,,0,N;Au,Cla 

prepared  by  Engeland  and  Kutscher  (Zeitsoh. 
Biol.  1912,  59,  415)  crystalliaes  in  short  needles 
which  melt  173°-175*'  to  a  clear  fluid.  Three 
methyl  groups  are  in  the  side  chain  BSkd  one  in 
the  guanidine  complex. 

Certain  aoyl  derivatives  and  esters  of  ai^^inine 
have  also  been  prepared,  the  dibemayl  denvative 
GcHj|0|N«Bz,  crystallises  in  rhombic  needles 
or  prisms,  m.p.  217-6°-218°  (Gulewitz,  I.e.),  the 
fi-ruiphihaleneaulphonic  derivative  OaHi,0,N4. 
SOj'CioH^  is  a  colourless  powder,  m.p.  88°-89** 
(ReiBser,  Ic) ;  diarginytarginine  is  isolated 
as  the  divicraU  Ci,H,a04N„(C.H,0,N,)„2H,0, 
m.p.  207  ,  from  the  product  obtained  by  hydro- 
lysmg  pepsin  extract  with  hydrosen  fluoride ; 
arginiflarginine  pioraie  Ci|H|eO,Ng,0«H,07N„ 
2H,0,  mj>.  213°,  is  similarly  obtained  from 
gelatin  (Hngouenq  and  Morel,  Compt.  rend. 
1909,  148,  236) ;  arginine  methyl  eder  hydro- 
chloride has  m.p.  196°  (corr.)  with  decomposi- 
tion, the  pierate  forms  lemon-yellow  crystals, 
which  melt  and  decompose  at  218°  (corr.) ; 
and  the  nitrate  melts  at  189"*  (corr.)  (Fischer 
and  Suzuki,  Sitzungber.  K.  Akad.  Wiss.  Berlin, 
1904. 1333). 

The  presence  of  arginine  assists  the  tryptio 
digestion  of  proteid  matter  and  aids  the  emulsifi- 
cation  of  fats :  this  appears  to  be  connected  with 
its  alkalinity,  as  sodium  carbonate  acts  similetrly 
(Lawroff,  Zeitsch.  physiol.  Chem.  1899,  28, 
303).  When  arginine  (hydrochloride  or  car- 
bonate) is  administered  as  a  food,  it  suffers 
complete  decomposition,  and  37-77  p.c.  of  the 
nitrogen  so  given  reappears  as  urea  (Thompson, 
Zeitsch.  physiol.  Chem.  1905,  33,  106),  and  the 
amount  of  arginine  in  the  various  organs  shows 
no  increase  (Oiglmeister,  Beitr.  Chem.  Physiol. 
Path.  1906,  7,  27).  Intravenous  injection  of 
arginine  increases  the  creatine  content  of  muscle 
(Thompson,  Proa  Physiol.  Soc.  ii.-iii. ;  J. 
Physiol.  1917,  61  ;  Jansen,  Arch.  Norland. 
Physiol.  1,  618).  Ackroyd  and  Hopkins  (Bio- 
Chem.  J.  1916,  10,  661-676)  suggest  that 
arginine  plays  a  special  part  in  purme  meta- 
bolism in  the  animal  boay.  Ringer,  Frankel, 
Jonas  (Bio-Chem.  J.  1913,  14,  525-538),  suggest 
that  succinic  acid  is  an  intermediate  compound 
in  the  katabolism  of  arginine. 

Arginine  gives  the  diacetyl  reaction  for 
proteids  (Haraen  and  Norris,  J.  Physiol.  1911, 
42,  333). 

Arginine  is  readily  oxidised  by  hot  calcium 
or  barium  permanganate  yielding  guanidine, 
7-guaninobutyric  acid  and  succinic  acid  (Benech, 
Kutscher,  Zeitsch.  physiol.  Chem.  1901,  32,  278, 
413,  and  the  estimation  of  the  number  of 
aiginine  groups  in  proteids  is  based  on  this 


reaction  (Orglmeister,  I.e. ;  Kutscher  and 
Zickgraf,  Sitzungsber.  K.  Akad.  Wiss.  Berlin, 
1903,  28,  624),  the  guanidine  thus  obtained 
being  isolated  in  the  form  of  its  sparingly  soluble 
pierate,  and  either  weighed  as  such,  or  the 
nitrogen  estimated  in  the  usual  way.  Another 
method  of  isolating  and  estimating  arginine 
is  based  on  Siegfried's  carbamino-reaction  of 
amino-  acids  (Zeitsch.  physiol.  Chem.  1906,  44, 
86 ;  46, 402  ;  1907,  60, 171 ;  Ber.  1906,  39, 397), 
whereby  the  barium,  strontium,  or  oalcium  salt 
of  the  corresponding  carbamic  acid  is  formed 
when  carbon  dioxide  is  passed  into  a  solution 
of  the  amino-  aci(|  containing  excess  cd  alkali 
earth  hydroxide  until  the  solution  is  neutral 
to  phenolphthaJein — 

RCHNH, 

I  -fCa(OH),+CO, 

CO,H 

RCHNHCO.v 

-   L. >-^^-° 

The  barium  and  strontium  salts  of  these  com- 
plex carbamic  acids  are  much  less  readily 
soluble  than  the  corresponding  amino-acid,  and 
afford  a  means  of  isolating  the  compounds 
(D.  R.  P.  188006,  1906).  In  order  to  estimate 
the  amino-  acid,  the  filtrate  containing  the 
calcium  salt  of  the  carbamic  acid  is  decomposed 
by  heating  with  boiled-out  water  into  oalcium 
carbonate,  and  the  amino  acid ;  the  ratio  CO,:N 
is  determined  by  weighing  the-caldam  carbonate 
thus  precipitated,  and  estimating  the  nitrogen 
in  the  filtrate  by  Kjeldahl's  method  (Zeitsoh. 
physiol.  C!hem.  1908,  64,  423). 

Van  Slyke  (J.  Biol.  Chem.  1911,  10,  26) 
precipitates  the  aiginine  with  phosphotungstio 
acid,  decomposes  me  precipitate  with  barium 
chloride,  and  boils  the  filtrate  gently  with  60  p.Q. 
potassium  hydroxide  for  six  hours ;  basing  nis 
estimation  of  arginine  on  the  fact  that  it  loses 
half  of  its  nitrogen,  in  the  form  of  ammonia, 
when  boiled  wi£h  dilute  alkali. 

PUmmer  (Bio-Chem.  J.  1916,  10,  116-110) 
decomposes  toe  arginine  with  20  p.c.  alkali 

Weohsler  (Zeitsch,  physiol.  Chem  1911,  73, 
138-43)  dissolves  the  dried  phosphotungstate 
precipitskto  in  a  mixture  of  acetone  and  water, 
and  tnen  deoompoees  it  with  barium  hydroxide. 

For  the  quantitative  estimation  of  arginine, 
in  proteins,  Jansen  (Chem.  Weekblad,  1917,  14, 
126)  uses  argin^se  to  decompose  the  ainnine 
and  the  urea  thus  produced  is  converted  into 
ammonium  carbonate  by  urease. 

(i^-Arginine  is  readily  produced  by  the 
tryptic  termentation  of  fibrin,  or  bv  heating 
(f-arginine  nitrate  at  210°-220°  for  15-20 
minut<eB  (Kutscher,  Zeitsch.  physiol.  Chem. 
1901,  32,  476)  or  by  heating  <{-arginine  in  50  p.c. 
sulphuric  acid  in  sealed  tubes  at  160°-180^  for 
33  hours  (Kcisccr,  Zeitsch.  physiol.  Cbem.  1906, 
49,  210) ;  it  decomposes  at  210*  (CSathoart,  Proo. 
Phvsiol.  Soo.  1905,  39) ;  the  nitraU  G^B.iS>t^» 
HNO.,  has  m.p.  216* ;  the  dinUrate  CfinOJ!^^ 
2HNO3,  m.p.  151* ;  the  cupric  nitrate  derivative 
2C,H,40,N4,Cu(NOs)„3H,0,  m.p.  228*-229*; 
the  stiver  nitrate  derivative  {OfiuOi'S^'SNO^)^, 
AgNO,,  m.p.  170M72*  ;  the  jwcnife  CJH^O.N^, 
C«H,0,N„  m.p.  20C°-201*,  is  sparingly  soluble 


ARGON. 


373 


100  parts  of  water  at  16*"  diasolvc  022  part;  the 

pierolonaU   C,Hi.O,N4,CioH,OeN4,  m.p.  248** 

100  CO.  of  water  at  16''  dissolye  003  ciamsof 

nit;  the  fi-naphthalen^  atUphanaie  C,H,,0,N4- 

60,Oi,H„|H,0  has  m.p.  86*'-90«  (Reisaer,  U). 

f-Aigmine  is  formed  by  treating  d^argmine 

carbonate    with   the   expressed   jmoe  of  calf's 

Uver,  the  ferment  arginas€  present  in  the  extract 

destroys  the  d-arginine,  and  does  not  attack  the 

levo-   isomeride.     With  the  exception   of   the 

difference   in   optical   activity,  the  salts  of  2- 

aiginine  are  identical  with  those  of  the  dextro- 

isomeride,  Uarginine    hydrochloride    has    [af^ 

-20^1*  (Reisser,  Z.c).  M.  A.  wf 

ARGININB.  This  name  has  also  been  given 
to  an  alkaloid  disoovered  by  Quiroga  (J.  Pharm. 
Chim.  1896, 16, 203)  in  a  species  of  &urel  (known 
by  the  natives  as  viraro-tni),  erowinff  in  the  east 
of  the  Argentine  and  west  of  BrazO.  It  forms 
prismatic  crystals,  soluble  in  chloroform  or 
benzene,  slightly  soluble  in  ether,  petroleum 
spirit,  or  water.  Its  aqueous  solutions, 
acidified-  with  hydrochloric  acid,  give  a  white 
ppt.  with  bromme  water  and  a  white  ppt. 
with  alkali  soluble  in  excess.  The  bark  and 
cambium  contain  1*5-1*6  p.a,  the  wood  0-Oi- 
0-06  p.c  of  the  alkaloid.  H.  I. 

ARGOFERMENT.  A  trade  name  for  a  form 
of  colloidal  silver. 

ARGOL  or  ARGAL.  {Tartre  hrui,  Fr. ; 
WeifuUin,  Ger.)  Crude  potassium  bitartrate, 
known  as  red  argol  {Cremore  di  Vinaccia),  or 
white  argol  {Cremore  di  8t.  Artimo),  according 
to  whether  it  is  deposited  from  the  red  or  the 
white  grape  (v.  Tabtabio  acid). 

ARGON.  8ym.  A*  or  Ar.  At.  wt.  and 
moleo.  wt.  39*88.  As  knur  ago  as  1786,  Caven- 
dish (Phil.  Trans.  75,  372)  made  experiments 
in  order  to  determine  whether  the  inwt  residue 
left  after  withdrawing  oxygen,  water,  and 
carbon  dioxide  from  air  was  homogeneous. 
He  sparked  a  mixture  of  air  and  oxygen 
in  presence  of  potash  for  the  absorption  of  the 
acid  produced,  and  removed  the  excess  of 
oxygen  by  a  solution  of  liver  of  sulphur.  Only 
a  small  oubble  of  ^as  remained  unabsorbed, 
and  this  did  not  dimmish  in  volume  on  further 
sparking  with  oxygen.  Cavendish  concluded 
'  that  if  there  is  any  part  of  the '  nitrogen  *  of  our 
atmosphere  which  differs  from  the  nst,  and 
cannot  be  reduced  to  nitrous  acid,  we  may  safely 
conclude  that  it  is  not  more  than  ^ )^  part  of 
the  whole.' 

Cavendishes  work  was  overlooked  for  more 
than  a  century,  and  attention  was  only  directed 


Argon  occurs  in  the  atmosphere  to  the 
extent  of  1*8  p.c.  by  weight  (Ixxiuc,  Compt. 
rend.  123,  805)  and  0*933  p.c.  by  volume 
(Schloeeiog,  Compt.  rend.  121,  604;  Moissan, 
Compt.  rend.  137,  600).  It  also  occurs  in  a 
large  number  of  minenJ  waters  and  thermal 
sprmgs  (Bouchard,  Compt.  rend.  121,  392; 
l^rooet  and  Ouvrard,  ibidi  121,  798 ;  Moissan, 
ibid.  135,  1278;  Moureu,  ibid.  135,  1335;  142, 
1155),  and  in  the  volcanic  gases  of  Mt.  Pelee 
(Moissan,  Compt.  rend.  135,  1085) ;  it  is  found, 
moreover,  in  &n  damp  and  in  coal  (Scfaloesing, 
Compt.  rend.  123,  233).  Arson  has  also  been 
observed,  together  with  h&um,  in  the  gas 
evolved  on  heating  numerous  minerals. 

Preparation.— (1)  By  sparking  air  with 
oxygen,  the  method  ominally  employed  by 
Cavendish  (v.  eupra).  The  gas  is  preferably 
conjQned  over  mercury,  and  a  small  quantity 
of  potash  introduced  through  a  curved  pipette. 
The  sparks  are  passed  between  the  ends  of 
stout  platinum  wires,  fused  throush  the  ends 
of  U-shaped  glass  tubes.  These  tubes  are  filled 
with  mercury,  and  serve  to  estaUish  elec- 
trical connection  with  the  secondary  terminals 
of  a  Ruhmkorff  coil  capable  of  ffiving  a  6-inch 
spark  through  air  when  workea  by  four  lead 
accumulators.  The  sparking  is  usually  con- 
tinued for  several  hours  after  contraction  has 
ceased ;  the  excess  of  oxygen  is  then  absorbed 
by  phosphorus  (Rayleuh  and  Ramsay,  {.c  ; 
Rayleigh,  Chem.  Soc.  ftoc.  13,  181;  Becker, 
Z.  Elek.  9,  600).  To  save  time,  it  is  customary 
to  prepare  by  method  (ii.)  a  gas  consisting 
mainly  of  argon,  and  to  employ  the  methoi 
of  sparking  only  to  remove  the  last  traces  of 
active  gases. 

(ii.)  From  *  atmoepherie  nitrogen,*  the  nitrogen 
being  dbeorhed  by  a  metaL  In  their  original 
investigation,  Rayleiffh  and  Ramsay  separated 
argon  from  nitrogen  by  continuously  circulating 
the  mixture  over  red-hot  maffnesium  shavings, 
whereby  the  nitrogen  was  absorbed,  forming 
magnesium  nitride  {cf,  Ramsay  and  Travers, 
Roy.  Soc.  Ptoc.  64,  183).  This  method  is  no 
longer  used  ;  a  dry  mixture  of  pure  lime  (6  parts) 
and  magnesium  dust  (3  parts),  introduced  by 
Maquenne,  is  employed  instead,  which,  when 
heated  to  redness,  produces  metallic  calcium 
and  absorbs  nitroggen  with  great  rapidity.  By 
passing  atmospheric  nitrogen  over  this  red-hot 
mixture,  and  leading  tto  residual  gas  over 
metallic  calcium  heatod  to  dull  redness,  complete 
absorption  of  the  nitrogen  is  readily  effected 

^ ^ (Moissan  and  Rigaut,  Compt.  rend.  137,  778). 

to  it^aftor  tde  discov«7v  In   1894/ by  Lord  i  Metallic  lithium  has  also  been  employed  for 


Rayleigh  (Roy.  Soc.  Proc.  55,  340),  that  the 
density  of  'atmospheric  nitrogen'  was  one- 
half  per  cent,  higher  than  tlui>t  of  nitrogen 
prepared  by  chemical  means.  This  result  gave 
uesn  indication  of  the  existence  of  some  hitherto 


the  same  purpose  (Guntz,  Compt.  rend.   120, 
777;   123,995). 

(iii)  The  readiest  means  of  preparing  argon 
in  quantity  consists  in  leadins  air  slowly  over 
a   mixture  of  caloium  carbi&   (90  p.c.)  and 


undiscovered  gas  in  the  atmosphere,  and  further  ,  oalcium  chloride  (10  p.o.)  heated  to  800^  the 
invesiigatkms,  earned  out  jointly  by  Rayleiffh  mixture  having  previousfy  been  heated  under 
and  Bamsay  (Phil.  Trans.  186,  187),  led  to  the  |  diminished  pressure  to  (uive  off  any  volatile 
isolation  of  a  new  gaseous  element.  The  gas,  i  matter.  Bothoxygen  and  nitrogen  are  absorbed 
which  has  a  density  of  approximately  20,  and  |  by  the  mixture.    The  issuing  gas  is  led  over  hot 


which  constitutes  nearly  1  p.a  by  volume  of  the 
atmosphere,  was  called  argon,  owing  to  its 
remarkable  chemical  inertness,  in  virtue  of  which 
it  can  be  readily  separated  from  the  accom- 
panying nitrogen. 


copper  oxide  to  bum  anjr  hydrogen,  hydro- 
carbons, and  carbon  monoxide  present,  and  the 
water  vapour  and  carbon  dioxide  removed. 
Usinff  7  kflos.  of  carbide,  11  litres  of  araon  may 
be  obtained  in  two  days  (Fischer  and  Ringe, 


374 


ARGM)N. 


Ber.  41,  2017).  ^^^  cyanamide  process  is  used 
in  America  as  a  means  of  producing  argon  in 
onantity.  Nitrogen  obtained  from  the  air  bv 
the  copper  process  is  repeatedly  passed  through 
the  cyanamide  furnaces  until  concentrated 
aigon  remains.  It  is  employed  in  the  electric 
lamp  industry,  c/.  Bodenstein  and  Wachenheim, 
(Ber.  1918,  61,  266). 

The  gas  prepared  by  the  above  methods 
contains  traces  of  the  other  inert  gases  neon, 
krypton,  and  xenon,  from  which  it  is  separated 
by  fractional  condensation  and  evaporation 
(Ramsay  and  Travers,  Boy.  Soc.  Proc.  67,  329  ; 
Liveing  and  Dewar,  Boy.  Soo.  Proc.  68,  389). 
The  total  quantity  of  these  gases  present  is, 
however,  only  0*26  p.a,  and  86  p.o.  of  this 
impurity  is  neon. 

The  oommeroial  oxygen  made  from  liquid 
air  contains  about  3  p.c.  of  arson  (Claude ; 
Morey).  The  liquid  mixture  is  then  distilled ; 
the  oxj^gen  condenses  and  the  argon  passes  on. 
There  is  obtained  a  gaseous  mixture  containing 
76-80  p.c.  of  argon  and  1-2  p.c.  of  nitrogen ;  the 
remainder  being  oxygen,  wmoh  may  be  removed 
by  combustion  witn  hydrogen. 

Aigon  may  be  obtained  by  passing  cooled 
compressed  air  downwards  through  a  rectifying 
column  and  bath  of  boiling  oxv^en  at  the  base. 
The  liquid  air  flows  over  to  the  nigher  part  of  the 
column,  the  interior  of  which  consists  of  an  inner 
chamber  with  draw-off  cocks  at  different  levels. 
In  this  the  mixture  is  separated  into  purer 
oxygen,  and  a  rich  aigon  mixture,  which  can  be 
useof  for  electric  lamps  (Eng.  Pat.  101860, 1916). 
Fonda  and  General  Electric  Ck).  (U.S.  Pat. 
1211126,  1917)  produce  a  Uquid  with  94  p.c. 
oxygen  and  4  p.c.  argon,  and  fractionate  it  on 
the  counter-current  principle  in  such  a  maimer 
that  argon  is  removed  at  tne  top  and  oxygen  at 
the  bottom  of  the  apparatus  (Reports  of  the 
Progress  of  Appl.  Ghem.  1917,  11,  201). 

Argon  is  a  colourless  gas,  condensing  to  a 
colourless  liquid,  boiling  at  86*9''  abs.  (  —  1861''- 
186-97760  mm.)  (F.  Fischer  and  Froboese,  Ber. 
1911,  44,  92),  at  which  temperature  its  density 
is  1*4046  (BfJy.  and  Donnan,  Chem.  Soc.  Trans. 
81,  914).  A  normal  litre  weighs  1*78376  at  0°, 
and  760  mm.  (Schultze,  Ann.  Physik.  1915  [iv.], 
48,  269),  coefficient  of  dilatation  i3=3669-10« 
(8''-32^).  Its  m.p.  is  83*4°  abe.  (-189*6°),  its 
critical  temperature  is  166*6°  abs.  (—117*4^- 
122*44°)  (Oommelin),  and  its  critical  pressure 
is  62*9  atmos.  (Bamsay  and  Travers,  Boy.  Soo. 
Proc.  67,  329). 

The  vapour  pressures  of  liquid  argon  are 
represented  by  the  formula  log  p= 4 '86033— 
634*391T+30769•09T»-1076464T^  For  solid 
argon  the  observations  are  best  expressed  by 
the  formula  log  p=A/T+BT-|-Dlog  T+C  in 
which  A=+9034*32,  B=-l*42112,  C=- 
1014*0278,  and  D= +633*0276.  The  molecular 
latent  heat  increases  from  12*92  at  —126*49°  to  I 
2401°  at -140*80°, and  3600(cal.)at  -18306** 
(Crommelin,  Proc.  K.  Akad.  Wetensoh.  Amster-  ' 
dam,  1913,  16.  477  ;  1914,  17,  276). 

Argon  is  more  soluble  in  water  than  nitrogen, 
the  absorption  coefficient  being  0*02661,  at  1°, 
and  falling  regularly  to  0*02667  at  60° 
(Estreicher,  Zeitsch.  phys.  Chem.  31, 176) ;  these 
figures  may,  however,  oe  in  error  by  6  p.c.  {v. 
Fox,   Ghem.   News,   99,   260).    The  refractive 


index  of  the  gas  for  sodium  light  at  N.T.P.  is 
1*0002837  (Burton,  Boy.  Soc.  Proc.  1908,  80, 
390);  its  thermal  conductivitv  is  0*00003894 
(Schwaize,  Pog^.  Ann.  11,  (iv.)  303) ;  and  its 
molecular  specific  heat  at  constant  volume 
is  2*977  cals.  (Pier,  Z.  Elek.  16,  636; 
Heuse  Ann.  de  Phyuk,  1919,  69,  86).  Its 
coefficient  of  expansion  is  0*003668  (Kuenen 
and  Bandall,  Boy,  Soc.  Proc.  69,  60).  Argon 
passes  through  rubber  more  quickly  than 
nitrogen  (Ba^eigh,  Phil.  Ma^^.  49,  (v.)  220)  or 
carbon  dioxide  (Kistiakowski,  J.  Buss.  Ghem. 
Soc.  30,  676),  and  does  not  pass  through  heated 
platinum  or  palladium;  it  is  diamagnetic 
(Tanzler,  Pogg.  Ann.  24,  tiv.)  931).  (For  its 
rate  of  effusion,  v.  Donnan  (Phil.  Mag.  49,  (v.) 
423).) 

The  density  of  argon  has  been  determined 
by  several  observers,  with  the  following  results  : 
(0=16);  19*940  (Bayleigh,  Boy.  Soc.  Proc 
69,  201),  19*941  (Bamsay,  Phil  Trans.  186,  238) ; 
19*946  (Fischer  and  Hahnel,  Ber.  43,  1436). 
Arson  is  a  member  of  the  group  of  inert  gases, 
and  up  to  the  present  all  attempts  to  combine 
it  with  other  elements  have  failed  (Bayleigh  and 
Bamsay,  l,c. ;  but  cf.  Gooke,  Zeitsch.  physikal. 
Ghem.  66,  637). 

Atomic  and  moUctdar  weight.  The  molecular 
weight,  39*88,  follows  from  the  density  determi- 
nations just  cited ;  but  the  atomic  weight  cannot 
be  determined  in  the  usual  manner,  amoe  aw>^ 
forms  no  compounds  with  other  elements.  The 
ratio  of  the  specific  heat  at  constant  pressure 
to  the  specific  heat  at  constant  volume  is  1*644 
(Bayleigh  and  Bamsay,.  2.c.),  and  this  result, 
from  ancdogy  with  the  case  of  mereury  vapour 
and  by  comparison  with  the  ratio  1*666  theoreti- 
cally required  for  a  monatomic  gas  according 
to  the  kinetic  theory,  is  regarded  as  proof  that 
argon  is  monatomic.  Its  atomic  weight  is 
therefore  39*88,  39*91  dbOOl  (Leduc,  Ann.  Phys. 
1918,  [ix.]  9,  6),  coefficient  of  departure  from 
Boyle's  Law  10*2,  10-*  between  1  and  6  atmos. 
mol.  vol.  0-999  at  0°  and  760  mm. 

Spectrum,  This  is  extremely  characteristicr 
and  has  been  carefully  examined  by  Grookes 
(Phil.  Trans.  186,  243),  Kayser  (Ghem.  News, 
72, 99),  Eder  and  Valenta  (Monatah.  16, 893 ;  17, 
60),  and  by  Trowbridge  and  Bichards  (PhiU 
Mag.  43,  (6)  77 ;  Staid  (Zeitsch.  wiss.  Photo- 
chem.  1911,  9,  302) ;  Stead  (Proc.  Gamb.  Phil. 
Soc.  1912,  16,  607).  The  most  prominent  lines 
are  two  in  the  red,  having  wave  lengths  of 
6966*6  and  7066*4,  a  yeUow  line  (6038*4),  two 
green  lines  (6610  and  4702),  and  a  violet  line 
(4200). 

ARGONIN.    Silver  casein. 

AR6ULAN.  Trade  name  for  the  mereury 
compound  of  dimethylphenylpyrazolene  sulpha- 
mine. 

ARGYRODITE.  A  sulpho-germaniate  of 
silver,  being  the  mineral  in  which  the  element 
germanium  was  discovered  in  1886.  It  had, 
however,  been  mentioned  by  A.  Breithaupt  in 
1823,  under  the  name  Flusinglanz.  These 
occurrences  in  the  HimmelBfiirst  silver-mine 
at  Freibeig,  Saxony,  show  only  botryoidal 
crusts  with  a  minutely  crystallised  surface. 
Later,  the  mineral  was  found  as  distinct,  though 
small,  cubic  crystals  in  Bolivia,   analysis  x>C 


ARSALYT. 


376 


which  proved  the  formula  to  be  Ag^GeSs  (S.  L. 
Penfiela,  1893  and  1894).  More  recently,  cubic 
crystals  of  larger  size  (3-5  cm.  across ;  sp.gr. 
6'*236)  from  (^Iquechaca,  Bolivia,  have  ot^n 
described  and  analysed  (V.  M.  Goldschmidt, 
1908).  At  this  locahty  the  mineral  appears  to  be 
not  uncommon,  and  no  doubt  large  quantities 
of  it  have  been  smelted  for  silver.  In  external 
appearance  it  is  not  unlike  argentite,  but  is  less 
sectile  than  this. 

In  the  Bolivian  mineral  the  germanium  may 
be  replaced  isomorphously  by  tin,  giving  the 
species  canfieldiU  AggSnSe  (Penfield,  1894). 
Intermediate  members  of  this  series,  or  stanni- 
ferous argyrodite,  also  occur  (Prior  and  Spencer, 
1898).  L.  J.  S. 

ARGTROL.    Syn.  for  silver- vitellin. 
ARHEOL.    Trade  name  for  santabol. 

ARHOIN.    Trade    name    for    an    addition 

Eroduct   of   diphenylamine   and   ethylthymyl- 
enzoate. 

ARIBINB  C„H,oN.,8H,0,  m.p.  229"^ 
(anhvdr.)  is  a  crystalline  diacid  ditertiary 
alkaloid  from  the  bark  of  Arariba  rubra,  a 
Brazilian  tree.  The  bark  is  used  for  dying  wool 
red  (Reith  and  Wohler,  Annalen,  1861, 120,  274). 
Aribine  is  one  of  the  very  few  solid  alkaloids 
free  from  oxygen,  and  sublimes  on  careful 
heating. 

ARISTINIC  ACID  Ci;H„0;N,  greenish- 
yellow  needles,  m.p.  276°  (decomp.).  Occurs 
with  arislidinic  acia  CigHigOvN,  and  aristoUc 
acid  C15H11O7N,  in  Aristolochia  argentine 
(Griseb.)  (Hesse,  Arch.  Pharm.  1896,  233, 
684). 

ARISTOCHIN  or  ARISTTOQUININE.  Trade 
name  fordi-quinine  carbonate  CO(0'GtoH2sNgO). 

ARISrOL.  Dithymol  di-iodide  used  as  an 
iodoform  substitute.     V.  Iodoform. 

ARISTOLOCmNE  C^HhOtN  (or 

^M^ai^is^i  ^)>  orange-yellow  needles,  decom- 
posing at  215°.  Occurs  in  Aristolochia  Clefnatitis 
(Ldnn.)  and  A.  rotunda  (Linn.).  It  is  a  weakly 
acid  base  (Pohl,  Arch.  expt.  Path.  Pharm.  1891, 
29,  282).  According  to  Hesse  (Arch.  Pharm. 
1895,  233,  684)  aristolochine  is  a  homologue  of 
aiistolic  acid  {see  under  Arietinic  acid).  The 
alkaloid  is  highly  toxic.  G.  B. 

AR JUN  WAX  V.  Waxbs. 

ARMENIAN  BOLE  v.  Piombnts. 

ABNATTO  V.  Annatto. 

ARNICA  V.  Rssnrs. 

ARNICA    YELLOW    v.    Azo-     colocbiko 

BfATTEBS. 

ARNOTTO  V.  Ankatto. 

AROMATIC  VINEGAR  v.  Acbtic  acid. 

ARRACK.  {Arack  and  Back,  Fr. ;  Arrack  : 
ReisbranrUiDein,  Ger.)  The  term  *  araq '  or 
*arak*  was  applied  by  the  Arabs  to  distilled 
spirits  generally,  but  it  is  now  usually  restricted 
to  the  spirituous  liquor  obtained  by  distillation 
of  the  fermented  juice  of  the  coco-nut  palm 
(toddy  or  palm  wine),  or  from  rice,  or  from  a 
mixture  of  ooth.  Arrack  is  also  made  from  the 
succulent  flowers  of  the  Bassia  irenus  of  trees 
and    from  other  vegetable  proaucts,  and    is 


manufactured  not  only  in  the  East,  but  also  in 
the  West  Indies. 

Where  rice  is  used,  it  is  steeped  in  water 
in  large  vats  and  agitated  cautiously  (so  as  not  to 
damage  the  grains,  which  would  interfere  with 
the  subsequent  fermentation)  until  about  half 
the.  rice  has  b^un  to  terminate.  The  water 
is  then  run  on  from  l>elow,  and  toddy  or 
molasses  or  a  mixture  of  these  is  added  to  the 
rice.  The  whole  ia  allowed  to  ferment,  and  the 
mixture  is  then  distilled. 

This  method,  which  is  said  to  produce  the 
best  quality  of  arrack,  obtains  at  Batavia  and 
in  Jamaica,  but  in  India  arrack  is  frequently 
made  from  toddy  alone. 

The  best  qualities  of  arrack  are  agreeable 
to  the  taste  and  wholesome,  which  cannot  be 
said  of  the  commoner  kind  made  from  rice 
alone,  in  some  parts  of  India  and  China.  This 
has  a  somewhat  nauseous  odour  and  taste, 
due  to  a  volatile  oil  which  distils  from  the  rice, 
and  ia  narcotic  and  very  unwholesome.  Its 
intoxicating  e£fect  is  frequently  increased  by 
the  addition  of  hemp  leaves,  poppy  heads, 
stramonium  juice,  &c. 

A  laige  amount  of  revenue  ia  obtained  from 
the  manufacture  of  arrack  in  Siam  end  Ceylon, 
and  the  latter  exports  a  considerable  quantity 
to  the  United  Kingdom,  where  it  is  used  as  a 
valuable  ingredient  in  making  punch. 

An  imitation  arrack  is  sometimes  made  by 
flavouring  rum  with  flowers  of  benjamin  or 
benzoic  acid.^  J.  C. 

ARRHENAL.  Disodium  methylarsinate. 
See  Arsenicals,  obganic. 

ARROPE.  Sherry  boiled  to  a  syrup  used  for 
colouring  other  wines. 

ARROWROOT.  The  starch  obtained  from 
the  rhizomes  of  Maranta  arundinacea,  grown  in 
the  West  Indies.  The  starch  prepared  from 
other  roots  is  often  known  locally  as  arrowroot ; 
e.g.  in  Queensland,  where  the  tubers  of  Canna 
edulis  supply  such  a  product. 

The  composition  of  the  roots  of  true  arrow- 
root grown  in  Jamaica  is  : 

Dextrin   Crude   Ether 
Water  Starch  and  sugar  fibre    extract  Proteid  Ash 

63-4     27-8        21         3*9       02        I'O      09 

(Leuscher,  Zeit.  oflentl.  Chem.  1902,  8,  23.) 

Commercial  arrowroot  contains  from  83*5  to 
86*9  p.c.  starch,  11*0  to  16  p.c.  water,  proteins 
from  0*4  to  1*4  p.c,  with  small  quantities 
{circa  0*3  p.c.)  of  a^,  cellulose,  and  fat. 

(For  a  series  of  analyses  of  arrowroots, 
from  various  sources,  see  Ballard,  Jour.  Pharm, 
1903,  17,  [10]  476.)  H.  L 

ARSACETIN.  The  sodium  salt  of  acetyl- 
p-aminophenyl  arsenic  acid — 

/OH 
CH,CO-NHC.H.=  As^O 

\ONa 

{v.  AaSBKICALS,  Oboanic). 

ARSACETIN-QUININE.  A  mixture  of  43  p.c. 
arsacetin  and  54  p.c.  of  quinine. 

ARSALYT.  Bismethylaminotetra-aminoar. 
senobenzene. 


376 


AR8AMIN. 


ABSAMIN,  Trade  name  for  sodium  anani- 
late.  Used  in  the  treatment  of  sleeping  sickness 
and  other  diseases  of  protozoal  origin. 

ARSAN.    Glidin  preparation  of  silver. 

ARSAHILIC  ACID.  p-Aminophenylaninic 
acid.    8u  Abshtioaia,  Organic. 

ARSENIC.  (Arsenic,  Fr. ;  Af9tnic,  Areen, 
Ger.)  SchioerbenkobaU,  Fliegengift,  N&pfchenko- 
halt  Arsenicum.  JUgulus  Arsenici.  Symbol, 
As ;  at.  wt.  74'96. 

Occurrence, — ^Arsenic,  in  small  quantities,  is 
one  of  the  most  widely  distributed  elements; 
it  is  found  in  mineral  and  other  waters,  in  sea- 
water  and  in  sea-weeds,  in  coal  smoke,  in  most 
pyretic  minerals,  and  in  a  large  number  of  ores. 

In  England  it  occurs  principally  with  <»n  ore, 
and  ontne  Continent  m  mtepickel.  Arsenic 
occurs  native  (usually  associated  with  iron, 
cobalt,  nickel,  antimony,  and  silver)  in  crystal- 
line rocks  and  in  the  older  schists,  generally  in 
reniform  and  stalaotitio  masses,  often  mammil- 
lated;  it  also  occurs  occasionally  in  rhombo- 
hedral  crystals.  At  Zimeoff  in  Siberia,  large 
masses  are  found ;  it  occurs  in  the  silver-mines 
of  Freiberg,  Annaberg,  Marienberff^  and  Sohnee- 
bers  in  Saxony ;  at  Joachimsthid  in  Bohemia, 
Anareasberg  in  the  Hartz,  Kapnik  in  Transyl- 
vania, Orawitza  in  the  Banat,  Kongsberg  in 
Norway,  St.  Marie-aux-Mines  in  AJsaoe.  in 
Borneo,  and  in  the  United  States. 

As  arsenide  it  occurs  combined  with  iron  in 
two  forms  FeAs.  and  FejAsi ;  with  nickel  as 
Kupfemickel  NiAs  and  NiAs.;  with  cobalt  as 
tin  white  edbaltf  CoAm^  With  antimony  it 
occurs  as  arsenical  antimony,  at  Przibram  in 
Bohemia ;  with  blende,  antimony  and  spathic 
iron,  at  Allemont,  at  Sohladming  in  Styria  and 
Andreasberg  in  the  Harts. 

Arsenic  is  senerally  present  in  native  sulphur. 
Combined  wiui  sulphur  it  occurs  as  realgar  or 
rtibp  sulphur  AS|St  in  Hungary,  Saxony, 
Switzerland,  and  Cnina ;  and  as  orpiment  As^S, 
in  Hungary  and  the  Hartz. 

With  sulphur  and  iron  it  occurs  as  mispickel, 
arsenical  pyrites,  or  white  mundic  FeSiFeAs, ;  with 
sulphur  and  cobalt  in  cobalt  glance  C0S3C0AS,  ; 
in  nickel  glance  KiStNiAs,,  and  in  a  number 
of  other  ores,  being  obtained  as  a  secondary 
product  in  the  roasting  of  tin  and  copper 
ores,  copper  nickel,  arsenical  faht  ores,  smaUine, 
cobalt  and  nickel  glance,  Jbo. 

With  oxygen,  arsenic  occurs  as  arsenolite  or 
arsenite  As^O«,  usually  as  a  crust  on  other 
arsenical  mmerals,  being  formed  by  their  de- 
composition. With  oaygen  and  etbaU,  it  forms 
cdbalt  bloom  or  arsenate  of  cobalt ;  it  also  occurs 
as  arsenates  of  iron,  copper,  and  lead. 

Preparation. — Motallio  arsenio-  is  used  only 
to  a  small  extent  in  commerce.  It  is  usually 
prepared  from  native  arsenic,  arsenical  iron,  or 
mispickel,  the  latter  being  the  only  mineral 
used  to  any  extent  in  England.  The  mineral 
used  is  heated  in  earthenware  retorts  or  tubes 
laid  horizontally  in  a  long  furnace.  Great  care 
IB  required  in  manufacturing  the  retorts;  a 
mixture  of  1  part  fresh  clay  and  2  parts  bricks 
or  old  retorts  powdered,  is  made  into  the  proper 
form,  coated  with  a  mixture  of  Uood,  loam, 
f  orge-Boalee  and  alum  to  produce  the  glaze,  and 
burned,    lliey  are  very  strong  and  heat-resist- 


ing, and  quite  impervioua  to  the  yapoor  of 
arsenic.  A  piece  of  Ihjn  iron  sheet  is  roUed  and 
inserted  into  the  mouth  of  the  retort,  and  an 
earthen  receiver  luted  on.  On  distilling,  most 
of  the  arsenic  condenses  in  the  iron  as  a  nearly 
white,  coherent,  internally  crystalline  mass,  and 
is  detached  on  cooling  by  unrolling  the  iron. 
If  required,  the  arsenic  is  purified  by  redistilla- 
tion. 

At  Altenberg  in  Silesia,  araenious  oxide  is 
heated  with  charcoal  in  an  earthen  crucible 
covered  with  an  inverted  crucible  or  conical  iron 
cap.  This  method  is  more  economical  and  pro- 
ductive than  the  one  above  described,  but  the 
metal  is  grey  and  pulTerulent,  and  always  con- 
tains  arsenious  acid. 

It  may  also  be  prepared  by  heating  the 
sulphides  with  charcoal  and  sodium  carbonate 
or  potassium  cyanide. 

Properties, — ^Arsenio  is  a  very  little  steel- 
grey  metalline  mass  of  sp.gr.  5*62  to  6*96,  of 
brilliant  lustre,  cr3rBtallising  in  rhombohedra, 
isomorphoDS  with  metallic  antimony.  It  is  a 
good  conductor  of  electricity,  and  is  odourless 
and  tasteless. 

It  is  volatile  at  temperatures  above  100**,  and 
is  rapidly  vaporised  at  a  dull-red  heat.  At  the 
ordinary  pressure  it  volatilises  without  previous 
fusion,  the  vapour  being  yellow  and  of  a  garlic 
smell,  but  when  heated  under  pressure  it  melts 
at  860''(dbl0'')  (817'',  Gouban,  Compt.  rend. 
1914,  168,  121;  862''  Heike,  Intern.  Zeitsch. 
MetdUographie,  1914,  6,  49).  Joubert  states 
that  alx>ve  200°  its  vapour  is  phosphorescent 
(Compt.  rend.  78,  1853). 

When  the  vapour  is  condensed  at  a  tempera- 
ture but  little  below  the  volatilising  poin^  t.e. 
when  condensed  in  an  atmosphere  of  arsenic,  a 
nearly  white  compact  mass  of  strongly  metallic 
lustre  is  producea  which  scarcely  oxidises  in  the 
air  even  when  heated  to  SO**.  When  it  is  de- 
posited on  a  coldea  surface  or  in  an  atmosphece 
other  than  arsenic,  it  forms  less  dense,  dark-grey 
crystals  which  resdily  oxidise  in  the  air  even  in 
the  cold,  and  especially  on  heating. 

Ludwig  (Aroh.  Pharm.  [2]  97,  23)  has 
obtained  arsenic  (?)  with  a  perfectly  bright  sur- 
face resembling  freshly  granulated  zinc,  and  of 
the  low  density  5*395,  by  dJHttilling  in  a  tube  with 
a  small  quantity  of  iodine. 

Bettendorf  (Annalen,  144,  110)  has  obtained 
a  specular,  amorphous,  vitreous  arsenic  of  sp.gr. 
4'69-4'716  by  subliming  arsenic  in  a  stream  of 
hydrogen  and  condensing  it  at  210*^-220^  At 
360^*  it  is  converted  into  the  crystaUine  form 
with  the  evolution  of  considerable  heat,  and 
when  heated  suddenly  it  hisses  and  gives  oCF 
vapour  whilst  transforming. 

There  is  a  yellow  form  of  arsenic  of  8p*gr- 
2*03  crystallising  in  the  r^ular  system.  These 
various  modifications  are  reganied  as  due  to 
differences  in  molecular  complexity,  or  as  arising 
from  the  same  quantity  of  matter  distributed 
throughout  a  varying  space  (Kohlschutter, 
Frank  and  Ehlers,  Annalen,  1913,  400,  268; 
Durrant,  Chem.  Soc.  Trans.  1919,  134).  Col- 
loidal arsenic  is  known  and  would  appear  to  be 
soluble  in  carbon  disulphide. 

When  heated  in  air  it  absorbs  oxygen,  burn- 
ing with  a  bluish  flame  and  forming  arsenious 


ARSENIC. 


S77 


oxide.  In  pure  water  it  is  unaltered,  but  when 
expofled  to  air  it  forms  a  grey  powder  supposed 
by  some  to  be  a  suboxide,  but  probably  a  mixture 
01  metallic  arsenic  and  arsenious  oxide ;  this 
powder  is  sold  as  *  flv-powder.'  When  powdered 
and  thrown  into  chlorine,  it  ignites,  forming  the 
trichloride  ;  with  the  aid  of  heat  it  combines  with 
bromine,  iodine,  and  sulphur.  Hydrochloric 
acid  has  but  little  action  on  arsenic,  but  it  is 
rapidly  dissolved  by  nitric  acid,  aqua  regia,  or 
by  a  mixture  of  hydioohlorio  acid  and  potassium 
chlorate. 

When  deflagrated  with  nitre  it  forms  potas- 
aiam  arsenate. 

Arsenic  is  a  constituent  of  many  alloys ;  it 
is  used  for  bronzing  brass  and  for  tne  manufac- 
ture of  opal  glass. 

(For  the  distribution  of  arsenic  in  commercial 
products,  V.  Arsenious  oxide.) 

Detection.  —  Arsenical  compounds,  when 
heated  on  charcoal,  give  off  the  characteristic 
garlic  odour  and  white  fumes  of  the  oxide,,  with 
a  white  incrustation  on  the  charcoal  some  dis- 
tance from  the  assay.  Metallic  arsenic,  and 
many  arsenical  minenls,  such  as  mispickel,  when 
heated  in  a  tube  dosed  at  one  end,  form  a 
blackish,  whining  metallic  ling  on  the  cooler 
portion  of  the  tube ;  if  heated  in  a 'tube  open 
at  both  ends,  the  arsenic  is  oxidised,  and  con- 
denses in  a  ring  of  white  octahedral  crystals, 
their  shape  being  plainly  visible  under  a  lens. 
On  cutting  off  the  closed  end  of  the  tube  con- 
taining the  metallic  mirror,  and  heatinff,  it  is 
also  converted  into  the  white  ring  higner  up 
the  tube.  The  white  crystals  dissolve  in  boiling 
water,  and  the  solution  shows  the  usual  tests 
for  aneuio.  Antimony  under  like  circumstances 
would  produce  a  white  ring,  which,  however,  \a 
Dot  crystalline,  and  is  not  soluble  in  water. 
Oxides  of  arsenic  require  to  be  mixed  with 
charcoal  before  they  produce  the  black  mirror. 
Sulphides  require  the  addition  of  alkaline  car- 
bonate or  potassium  cyanide,  or  they  may  be 
heated  with  baryta  alone  (Brame). 

White  arsenic  when  heated  with  about  3 
parts  of  sodium  acetate,  gives  the  offensive  smell 
of  kakodyl. 

In  solution  the  reactions  of  the  two  series  of 
compounds,  the  arsenious  and  the  arsenic,  differ 
considerably ;  generally  speaking,  arsenic  com- 
pounds may  be  converted  into  the  arsenious 
form  by  heating  with  sulphurous  acid  or  with 
a  sulphite. 

Beinsch*s  test.  If  a  piece  of  clean  metallic 
copper  is  immersed  in  a  solution  of  arseoious 
acid  or  an  arsenious  compound  acidulated  with 
pure  hydrochloric  acid,  it  is  coated  with  a  grey 
nlm,  which  is  probably  «n  arsenide  of  copper. 
The  action  proceeds  better  at  the  boiling^  tem- 
perature. The  acid  must  first  be  tested  in  the 
same  manner  to  ensure  the  absence  of  arsenic, 
which  is  always  present  in  the  commercial  acid. 
The  metal  is  washed,  dried  gently  and  heated 
in  a  tube,  when  the  arsenic  becomes  oxidised 
and  forms  a  cryHaUine  ring  on  the  colder  part  of 
the  tube.  A  film  due  to  antimony,  aa  mentioned 
before,  would  not  produce  a  crystalline  ring. 

This  method  is  used  in  testing  for  and  re- 
moving arsenic  from  hydrochloric  acid,  and  in 


toxicology;    by  it  I  part  oi  octenlc  can  be 
detected  m  260,000  parts  of  solution. 

It  is  not  so  delicate  as  Marsh's  or  the  electro- 
lytic  method. 

When  hydrogen  is  generated  in  a  liquid  con- 
taining an  arsenious  compound,  the  arsenic 
combines  with  it  and  passes  off  as  the  gaseous 
hydride  ;  many  very  delicate  tests  are  based  on 
this  reaction. 

( 1)  Fleitmann's  test.  The  solution  is  mixed 
with  excess  of  caustic  potash,  a  piece  of  pure 
zinc,  or  of  magnesium,  or  aluminium  foil  in- 
serted, and  the  solution  heated.  A  piece  of  filter 
paper  moistened  with  silver  nitrate  is  hdd  over 
the  mouth  of  the  tube.  In  presence  of  arsenic, 
arseniuretted  hydrogen  is  produced  and  reduces 
the  silver  on  the  pa^  forming  a  greyish  or 
purpUsh  colour.  Antimony  is  not  evolved  in 
this  test.  Fleitmann's  test  is  therefore  a  ready 
means  of  findins  arsenic  in  presence  of  antimony ; 
it  is  not,  however/  so  oelicate  as  Reinsch  s, 
Marsh*s,  or  the  electrolytic  method.  Or  instead 
of  silver  nitrate  the  paper  (preferably  Michallet 
drawing  paper),  cut  into  strips,  may  be  soaked  in 
a  1  p.0.  solution  of  mercuric  chloride  and, 
after  drying,  exposed  to  the  gas,  when  the 
arseniuretted  hydrogen  produces  a  stain. 

Outzeit  test.  For  a  convenient  form  of 
apparatus  for  making  this  test,  adapted  to  works 

Sractice,  see  Hollins,  Jour.  Soc.  Chem.  Ind.  1917, 
6,  676. 

(2)  Marshes  test.  This  or  Reinsch's  test  is 
usually  used  in  toxicology.  The  solution  is 
acidulated  with  pure  hydrochloric  acid  and  in- 
troduced into  an  apparatus  in  which  hydrogen  is 
generated  by  means  of  pure  sulphuric  acid  and 
zinc.  Arsenic  hydride  is  formed  and  is  passed 
through  a  narrow  glass  tube,  which  is  heated  at 
one  spot  by  a  lamp  ;  the  arseniuretted  hydrogen 
as  it  passes  over  the  heated  portion  is  decom- 
posed with  the  precipitation  of^arsenio  as  a  black 
ring.  In  testing  for  very  small  quantities  of 
arsenic,  the  action  should  oe  continued  for  about 
an  hour.  A  blank  experiment  should  always  be 
performed  in  the  same  manner  to  ensure  the 
purity  of  the  zinc  and  acid.  It  is  essential  not 
only  to  obtain  zinc  and  acid  which  are  free  from 
traces  of  arsenic,  but  also  to  see  that  the  zinc 
used  is  *  sensitive,'  and  will  permit  all  the  arsenic 
in  the  solution  to  be  evolved  as  arseniuretted 
hydrogen.  The  presence  in  the  solution  of 
certain  metals — ^notably  iron — is  liable  to  retard, 
or  entirely  prevent,  the  evolution  of  arseniuretted 
hydrogen.  (On  the  presence  of  arsenic  in  glass 
as  a  source  of  error  m  the  detection  of  arsenic, 
V.  W.  Fresenius,  Zeitsch.  anal.  Chem.  22,  397  ; 
Ber.  17,  2938.)  Instead  of  heating  the  tube,  the 
gas  may  be  ignited  at  the  mouth  of  the  tube,  and 
the  flame  caused  to  impinge  on  a  cold  surface  of 
porcelain,  or  preferably  of  platinum  foil.  The 
arsenic  film  may  be  distinguished  from  that 
produced  by  antimony  as  foUows  : — 

(1)  The  arsenic  film  is  quickly  evaporated, 
while  that  of  antimony  only  slowly  disappears. 
Helling  (Das  Microscop  in  der  Toxicologie)  re- 
commends that  small  spots  be  heated  and  the 
▼apour  received  on  a  shp  of  glass,  when,  under 
the  microscope,  the  octahedral  crystals  due  to 
arsenic  are  visible. 


378 


ARSENIC. 


(2)  The  arsenic  film  quickly  dissolves  in  a 
freshly  prepared  solution  of  sodium  hypo- 
chlorite; the  antimony  film  is  very  slowly 
soluble.  Old  hypochlorite  solutions  contain 
chlorite  which  dissolves  the  antimony  mirror. 

(3)  The  antimony  film  dissolves  quickly  in 
yellow  ammonium  sulphide,  leaving  an  oranee- 
yellow  residue  on  evaporation ;  the  arsenic  mm 
dissolves  very  slowly. 

Magnesium  may  also  be  employed  in  place  of 
zinc,  and  £.  Davy  and  Al.  Jandousch  use  an 
amalgam  of  i  part  sodium  in  8  parts  mercury, 
with  or  without  acid. 

The  presence  of  nitrates  or  nitric  acid  inter- 
feres with  this  test,  and  the  acids  used  should 
be  dilute. 

Bettendorfs  test,  A  solution  of  stannous 
chloride  in  concentrated  hydrochloric  acid  is 
mixed  in  a  test-tube  with  a  solution  of  the 
substance  in  hydrochloric  ^id,  and  heated  to 
boiling,  when  a  brown  colouration  indicates  the 
presence  of  arsenic. 

For  the  detection  of  small  quantities  of 
arsenic  in  toxicology*  Billeter  (Helv.  Chim.  Acta, 
1918,  1,  476 ;  Amilyst,  1919,  51)  recommends 
that  the  substance  be  treated  with  nitric  and 
sulphuric  acids  to  destrov  organic  matter,  the 
sulphuric  acid  solution  then  distilled  with  the 
addition  of  sodium  chloride  and  potassium 
bromide,  the  distillate  evaporated  with  the 
addition  of  hypochlorous  acia,  and  the  residual 
solution  tested  in  the  Marsh  apparatus.  The 
distillation  part  of  the  process  is  essential  to 
ensure  removal  of  heavy  metals,  particularly 
mercury,  traces  of  which  completely  mask  the 
presence  of  relatively  large  quantities  of  arsenic 
in  the  Marsh  apparatus.  The  addition  of 
hypochlorous  acid  aurin£  concentration  of  the 
hydrochloric  acid  solution  prevents  loss  of 
arsenic. 

(For  the  detection  and  estimation  of  arsenic 
by  electrolytical  methods,  v.  Arsenic  in  art. 
Analysis,  Elbctbo-chemical.) 

Estimation, — ^Arsenic  is  usually  estimated 
as  (1)  magnesium  pyro-arsenate ;  (2)  as  arsenic 
sulphide ;   (3)  as  metallic  arsenic. 

(1)  For  this  method  it  is  necessary  that 
the  substance  should  be  present  as  an  arsenic 
compound.  The  conversion  from  the  arsenious 
to  tne  arsenic  condition  may  be  effected  by 
heating  with  nitric  acid  {v.  Estimation  as 
sulphide)  or  hydrochloric  acid  and  potassium 
chlorate. 

The  acid  solution,  which  should  occupy  only 
a  small  bulk,  is  mixed  with  *  magnesia  mixture  * 
and  rendered  strongly  alkaline  with  ammonia. 
After  standing  for  24  hours,  the  solution  is 
filtered,  the  hut  portions  of  the  precipitate, 
which  consists  of  ammonium  magnesium  arsen- 
ate, beinjg  washed  entirely  on  to  the  filter  paper 
with  a  little  of  the  filtrate  (the  volume  of  this 
filtrate  should  be  noted  roughly).  The  preci- 
pitate is  then  washed  with  a  mixture  of  1  part 
strong  ammonia  and  3  parts  water,  until  only  a 
slight  opalescence  is  produced  on  the  addition 
of  nitric  acid  and  silver  nitrate  to  a  few  drops 
of  the  washings.  It  is  then  dried,  detached  as 
much  as  possible  from  the  filter  paper,  and 
transferred  to  a  weighed  porcelain  crucible, 
moistened  with  nitric  acid,  dned,  and  ignited,  at 


first  gently,  and  finally  to  bright  redness.  The 
paper  La  moistened  with  nitrio  acid,  dried,  and 
ignited  on  the  lid,  and  the  crucible  and  its 
contents  weighed.  The  ignited  residue  consists 
of  magnesium  pyro-arsenate  MgiASfOf,  and 
contains  48-27  p.o.  of  arsenic. 

On  account  of  the  solubility  of  the  ammonium 
magnesium  arsenate,  an  addition  should  be 
made  to  the  weight  obtained  ot  0*001  gram  for 
each  16  o.c.  of  filtrate  obtained,  not  counting  the 
washings. 

(2)  The  arsenic  for  this  method  should  be 
in  the  arsenious  form.  If  arsenic  compounds 
are  present,  they  are  preferably  reduced  by 
passing  a  current  of  sulphurous  acid  through  tlie 
tiqiiid,  the  excess  of  that  gas  being  driven  off  b^ 
suDsequent  heating.  Sulphuretted  hydrogen  is 
then  passed  through  the  liquid  until  thoroughly 
saturated,  the  liquid  left  to  stand  for  some  time, 
the  excess  of  sulphuretted  hydrogen  driven  off 
bv  heating,  and  the  precipitated  arsenious  sul- 
phide containing  sulpnur  filtered  off.  The  sul- 
phide is  dissolv^  in  amnionia,  filtered  if  neces- 
sary, and  the  arsenic  estimated  in  the  solution 
by  one  of  the  three  following  methods : — 

(a)  The  solution  is  evaporated  to  drvneas  hi 
a  porcelain  dish,  then  covered  with  an  m  verted 
funnel,  and  fuming  nitric  acid  added.  After  the 
first  violent  action  has  ceased,  the  liquid  is 
heated  on  a  water-bath  until  the  whole  of  the 
sulphur  has  disappeared,  and  only  a  small  bulk 
of  liquid  remains ;  *  magnesia  mixture '  is  then 
added,  followed  by  excess  of  ammonia,  and  the 
process  followed  as  already  described. 

(&)  The  ammoniacal  solution  is  evaporated 
to  dryness  in  a  porcelain  dish,  and  heated  on  a 
sand-bath  to  drive  off  the  whole  of  the  free 
sulphur  and  carbonise  any  oiganic  matter 
(which  is  frequently  present  in  toxicolo^pcal 
analysis)  without  volatilising  an^r  of  the  arsenious 
sulphide.  The  residue  is  again  dissolved  in 
ammonia,  filtered  if  necessary,  evaporated  to 
dryness,  and  gently  heated  in  a  weighed  porce- 
lain dish,  and  weighed  as  arsenious  sulphide 
A«,Ss  (Mohr,  Chem.  Toxicologic,  66). 

(c)  The  arsenic  in  the  solution  may  be 
estimated  by  means  of  standard  iodine  solution 
(Champion  and  Pellet,  BulL  Soc  chim.  [2]  26, 
641). 

(3)  For  this  method  the  arsenical  mirror 
obtained  by  the  Marsh-Berzelius  method  or  the 
electrolytic  method  may  be  estimated  by  com- 
parison with  standard  mirrors  obtained  under 
similar  conditions  to  the  estimation.  Elxperienoe 
has  shown  that  when  in  the  preparation  of  stand- 
ard mirrors,  the  quantities  of  arsenic  used  differ 
by  amounts  such  as  0*002  milligram,  a  series  of 
mirrors  can  be  obtained  showing  differenoes  in 
intensity  which  are  sufficiently  distinct  and 
constant  to  be  utilised  for  comparison. 

SeparaUon  from  other  mekUs,— Certain  heav  v 
metals,  if  present,  would  be  precipitated  with 
the  arsenious  sulphide  bv  means  of  sulphuretted 
hydroffen.  From  the  sulphides  of  lead,  bismuth, 
&c.,  the  arsenious  sulphide  can  be  dissolved  by 
digestion  in  ammonium  sulphide.  The  solution 
would  also  contain  antimony  and  tin,  if  present. 
The  separation  of  arsenic  from  these  two  metals 
may  bo  performed  as  follows  : — 

From  antimony.  The  mixed  sulphides  are 
oxidised  with  aqua  rtgia,  sa  ahready  described, 
and  tartaric  add  solution  added,  followed  by 


1  chloride  and 
The  Utter  should  {xoduoe  no  onleBoence.  If  tt 
[a«cipit&te  ii  piodaoed,  >  further  qnantitj  of 
tsrtaiio  scid  oi  unmoDiam  chloride  must  be 
■ddad.  The  Bolntion  is  then  xa;ecipit»t«d  by 
'  m^necuL  mixtora,'  Mid  the  eatimntion  made 
u  befwe  described. 

Fron  tin.  A  Kilutian  of  oxalic  acid  is 
added  to  the  lolution  in  the  proportion  of  20 
gianu  of  oxalio  acid  for  each  gram  of  tin  gup- 
'  poaed  to  be  pteaent.  The  solution  sboold  bo 
suffioientl;  atrong  for  the  add  to  cr;ata!liAe  oat 
on  oocding.  The  liquid  ia  heated  to  boiling  and 
BolphDretted  hjdn^en  passed  through  for  20 
minutes.  The  liquid  is  allowed  to  stand  for 
about  30  minntea,  and  the  araonjons  sulphide 
GlUMd  off.     It  a  quite  free  from  tin. 

Anenions  chloride  in  small  qnaotities  may  be 
separated  from  other  metals  by  disUilation  ot  the 
hvdroahlorio  solution  (Thorpe,  Cham.  Soo.  Trans. 


snitAble  solution  of  ferric  and  calcium  chlorides, 
acidiSed  with  hydrochloric  acid  (the  materials 
used  should  be  tmtod  for  anenio).  With  a 
solution  of  ainc  and  ouprio  chlorides  in  hydro- 
chlorio  acid  boiling  at  108*  both  arsenic  and 
antimony  may  be  separated  from  other  metals  i 
the  arsenic  ism  the  distillate  from  lOS'to  115*, 
the  antimony  in  th«  distillate  from  llS°to  160* 
(Oibb,  J.  Soo.  Chem.  Ind.  xx.  3). 

Pot  the  estimation  of  arsenic  in  ores,  PameU 
recommends  the  following  method  : — A  weighed 
quantity  of  the  fituly  ptiwdtred  ore  is  heated  to 
abont  200*  in  a  ilow  corrent  of  chlorine  sas, 
the  volatilised  anenious  chloride  being  absorbed 
in  a  solution  of  chlorine  water.  After  evapora- 
tion of  the  esceci  ot  chlorine,  the  arsenic  may 
b«  Mtinated  by  any  ordinary  method.  Anti- 
mony, if  ^Ment  in  the  ore,  would  also  volatilise 
with  the  anenio. 

Tot  teelmioal  pnrpo«M  the  following  msthodi 
are  largely  used : — 

A  Te^hed  portion  is  partially  decomposed 
_:»>.  .  ^.^iT^,„jy  quantity  of  strong  nitrio  acid. 


dried  and  fused  with  sodium  peronde 
tore  of  sodium  carbonate  and  nitre.  The  fustd 
mass  IS  extracted  with  water  and  Stored.  The 
■olotioD  of  alkaline  arsenate  is  aoidiSed  with 
nitria  acid  and  boiled  to  effect  deoompoaition  of 
either  peroxide  or  nitrite ;  it  is  next  oarefullv 
neutralised  and  then  acidised  with  aoetio  acid, 
and  the  arsenic  determined  by  titration  with  a 
standard  solution  of  uranium  acetate.  Pearcs 
recommends  separation  as  silver  arsenate  from 
the  aqueous  extract  after  fusion  ;  the  silver 
salt  is  dissolved  in  dilute  nitrio  acid  aiid  estimated 
by  Volhard's  method.  With  very  poor  ores  to 
the  solution  in  nitric  acid  a  sufficient  quantity  of 
tartarie  add  is  added,  and  the  arsenic  separated 
a*  magnesium  ammonium  arsenatA.  For  the 
estimation  of  arsenic  in  organic  salte  i^ite  with 
sodium  pwoside,  reduce  with  hydnodio  add 
and  tilMt«  with  iodine  and  starch  in  presence 
of  disodium  hydrogen  pboaphate  (Morgan,  Chem. 
Soc.  Trans.  1906.  96,  UTT]. 

AUojrf  of  UMDle. 

Arsenic  combinea  with  most  metals,  in  many 


I  in  atomic  proportioos,  the  alloys  being 
Lnen  known  as  arsenide*.  Uaoy  natural 
.arsenides  occur  aa  minerals. 


Uaoy    nati 
Tba  alloys  may  be  prepared  (I)  by  fusing 


;NIG  379 

the  metals   undei   a  layer  ot  borax,   or  in  an 

atmosphere  of  some  inert  ga«  ;  (2)  by  reducing  the 
arsenite  or  arsonatA  of  the  metal  with  potassium 
cyanide ;  and  (3)  in  some  cases — as  with  gold, 
sUver,  and  copper — by  placing  arsenic  la  a 
aolution  of  a  metallic  salt.  W.  Spring  (Bei.  IS, 
324)  bos  obtained  crystalline  alloys  ot  ataenic 
with  other  metals  by  repeatedly  compressing  a 
mixture   of    the   constituents   at   6S00   atmo- 

When  heated  out  of  contact  with  air,  arsenical 
alloya  usually  lose  a  por(i(»i  of  Uieir  arsenic ; 
heated  in  air  the  arsenic  is  oxidised,  a  portion 
volatilising,  and  the  remainder  (csming  an 
arsenite  or  arsenate  of  the  metal.  When  heated 
with  nitre,  arsenates  are  produoed.  (For  a  list 
of  alloys  of  arsenic  in  atomic  proportitms, 
probably  existing  as  arsenides,  d.  A.  Deecamps, 
Compt.  rend.  686, 1022  and  I06S.)  Some  ancient 
copper  spear-heods  from  Qyprue  coatained 
1-3^  p.o.  arsenic,  and  a  bronie  figure  of 
the  Ptolemaic  period  from  Bgypt  oontained 
1-479  p.c. 


In  Pattinson's  process  it  tends  to  render  the 
crystals  smaller,  and  thus  lengthens  the  lime 
required  (or  draining.  Its  alloys  with  iron,  sine, 
and  tin  are  brittle  ;  with  gold  and  silver,  brittle, 
and  gcey ;  and  with  lead  and  antimony,  hard, 
brittle,  and  fusible.    The  addition  of  from  3  to  6 


down  the  tower  to  form  spheres,  instead  01 
elongating,  as  they  have  otherwise  a  tendency 
to  do.  The  anenic  is  frequently  added  in  the 
proper  proportions  in  the  form  of  an  allo^  of 
lead  and  arsenic  known  as  '  temper ' ;  this  is 
prepared  by  fusing  tt^ther  arsenious  oxide  and 
leaA,  By  beating  a  mixture  of  lead  and  arsenic 
to  whiteness,  Berthier  obtained  an  alloy  of 
the  formula  PbiAs,  any  excess  of  arsenic  beyond 
that  corresponding  to  this  formula  being  vola- 
tilised at  that  temperature.  With  copper  it 
forms  white,  malleable,  dense,  and  fusible  allo^ 
White  copper  contains  about  10  p.c.  arsenic 
Arsenic  is  also  used  in  speculum  metal,  and 


Pio.  1. 
it  frequently  present  in  common  Britamua  metal 


380 


ARSENIC. 


With  potassium  and  sodium  araenio  forms 
alloys  which  evolve  arseniuretted  hydrogen  when 
plated  in  water.  With  platinum  it  forms  a 
tusible  alloy,  and  was  formerly  used  to  facilitate 
the  working  of  that  metal.  It  forms  an  amalgam 
As^Hg,  (Dumesnil,  Compt.  rend.  1911,  152, 
868). 

Arsenic  trihydride.  ArseneUed  or  a/rwni- 
ureUed  hydrogen,  Arsine.  AsH,.  This  gas  is 
formed  whenever  hydrogen  is  liberated  in  a 
solution  containing  arsenious  acid  or  an  ansenite, 
as  when  sine  is  introduced  into  an  add  solution 
of  the  substance.  It  is  a  colourless,  neutral, 
disagreeably  smelling  gas,  slightly  soluble  in 
water,  and  highly  poisonous,  even  when  much 
diluted.  At  a  red  heat  it  decomposes  into 
anenio  and  hydrogen. 

It  can  be  condensed  to  a  liquid,  and  forms  a 
hydrate  AsH„6H,0  (De  Forcrand). 

It  is  evolved  in  the  bronzing  of  brass  with 
arsenic,  in  tinning  sheet  iron  and  frequently  in 
the  desilverisation  of  lead  with  zinc  and  snoee- 
quent  heating  of  the  argentiferous  zinc  with 
acid.  It  is  a  very  powerful  reducing  agent, 
precipitatinjB;  silver,  gold,  and  other  metab  from 
their  solutions.  IMtethods  for  the  quantita- 
tive estimation  of  arsenic  are  based  on  this 
property. 

A  solid  hydride  of  arsenic  H,AS|  is  formed 
by  the  action  of  an  electric  discharge  on  the 
tnhydride  in  an  ozoniser,  or  by  the  cfecomposi- 
tion  of  sodium  arsenide;  or,  mixed  with 
arsenic,  by  the  action  of  the  trihydride  on 
solid  alkali  hydroxide  followed  by  the  addition  of 
water : 

(1)  AsH,+3K0H=K^-f  3H,0 

(2)  2K^-|-6H,0-As,H,-f  6K0H-f 2H, 

(Reckleben  and  Scheiber,  Zeitsch.  anorv.  Cllem. 
1911,  70,  256).  * 

Anenlous  oxide.  AraenUma  acid.  White 
arsenic,  Fknoere  of  areenic ;  commonly  knoum 
as  *  arsenic.*    As^Oe. 

Prep(mUion.—la  Ck>mwall,  Devon,  and  at 
Swansea,  arsenious  oxide  is  principally  prepared 
by  roasting  mispickel,  which  occurs  mixed  with 
iron  and  copper  pyrites,  tin  ore,  wolfram,  blende, 
galena,  &o.  These  ores,  if  present  in  sufficient 
quantity,  are  separated  as  far  as  possible  before 
roasting;  tinstone  by  washing  the  finely 
powdered  ore,  and  the  other  minerals  by 
hand.  Arsenious  oxide  is  also  largely  prepazed 
by  roasting  arsenical  silver  at  Andreasberg, 
and  from  arsenical  ores  of  nickel  and  co- 
balt. 

In  ores  from  which  arseiuc  is  produced 
as  a  principal  product,  the  arsenical  pyrites 
generally  occur  to  the  amount  of  about  12 
p.c. 

.The  ores  are  usually  roasted  in  a  reverbera- 
tory  furnace.  In  a  common  form,  the  furnace 
bed  is  fiat,  12-15  feet  long  and  7-9  feet  wide 
in  the  middle ;  the  arch  is  about  2  feet  above 
the  bed,  and  sinks  gradually  towards  the  fine, 
at  which  end  there  is  an  iron  door,  through 
which  the  ore  is  raked  (Fig.  1). 

From  8-15  owt.  ol  the  stamped  dried  ore  is 
introduced  through  a  hopper  over  the  centre  of 


the  fire-bridge  and  spread  over  the  furnace  bed. 
The  heat  is  raised  to  dull  redness  and  the  ore 
is  frequently  stirred  to  ensure  thorough  oxida- 
tion of  the  arsenic  and  sulphur.  In  about  10 
hours  these  have  been  expelled  as  oxides,  and 
the  arsenious  oxide  together  with  some  of  the 
sulphur  collects  in  the  flues.  The  spent  ore 
is  removed  through  an  aperture  in  the  bed, 
which  is  closed  with  an  iron  door  during  calci- 
nation. 

Two  such  furnaces  are  sometimes  built  side 
by  side,  separated  by  a  wall,  and  with  their  flues 
uniting.  The  furnace  beds  slope  gently  towards 
a  narrow  fireplace.  In  the  first  instance 
.the  ore  is  introduced  through  a  number  of 
doors  on  each  side  of  the  fumaoe.  As  the  ore 
is  worked  downwards  its  place  is  oonstantly 
supplied  by  fresh  ore  through  an  opening  in  the 
roof. 

Brunton's  Calciner  is  much  used  in  Cornwall. 
It  is  praoticaUy  a  reverberatory  furnace  with  a 
revolving  bed.  The  bed  is  of  firebri€dc  resting 
on  a  cast-iron  table,  and  is  higher  at  the  centre 
than  at  the  periphery.  It  is  usually  8  or  10  feet 
in  diameter ;  it  revolves  three  or  four  times  in 
an  hour  by  steam  or  water  power,  about  half- 
horse  power  being  required!  There  are  two 
fomaces  on  opposite  sides  of  the  bed. 

The  dried  and  finely  stamped  ore  is  intro- 
duced through  a  hopper  over  the  centre  of  the 
bed.  Above  the  bea  are  fixed  radially  three  oast- 
iron  frames  in  which  are  fastened  a  number  of 
equidistant  iron  scrapers  shaped  like  the  coulter 
of  a  plough  and  placed  obliquely,  so  that,  as  the 
bed  revolves,  they  turn  the  ore  over  and  outwards 
towards  the  penphery  of  the  bed.  It  is  thus 
thoroughly  roasted,  and,  on  reaching  the  edge, 
falls  into  the  chamber  beneath. 

(hdani  and  Hocking's  Patent  Calciner 
(English  Pat.  1888,  2950)  is  largely  used,  espe- 
cialfy  for  'rank  *  ores  (Fifls.  2and  8).  It  consists 
of  a  wrouffht-iron  cylinaer,  which,  if  32  feet  in 
length,  is  uned  with  sufficient  firebriok  to  leave 
4  feet  dear  internal  diameter.  Four  longi- 
tudinal ribs  of  firebrick  occur  within  the  furnace, 
leavmg  sufficient  space  at  the  upper  end  for  the 
continuous  supply  of  the  ore.  The  cylinder  is 
generally  mounted  in  an  indined  pontion,  the 
slope  being  usually  }  to  1  inch  per  foot,  and  is 
turned  by  means  of  a  turbine  or  water-wheel 
onee  in  8  or  10  minutes  upon  friotion-wlieds. 

The  dried,  findy  powdered  ore  is  introduced 
through  an  arohimeidean  screw,  or  from  a  hopper 
at  the  upper  end,  and  in  the  revolution  of  the 
tube  becomes  lifted  to  a  certain  heiffht  by  the 
ribs  of  firebrick,  and  falls  in  a  &e  stream 
through  the  hot  blast.  In  a  few  revdations  the 
jore  is  completdy  oxidised,  the  arsenio  burning 
off  first,  and  finiuly  reaches  the  lower  end  of  Uie 
tube,  where  it  faUs  through  a  chamber  beneath. 
A  calciner  of  the  above  size  will  roast  6  to  7 
tons  of  ore  in  24  hours.  In  this  furnace  the 
amount  of  air  required  is  minimised,  thus  render- 
mg  the  condensation  less  difficult.  The  amount 
of  fuel  used  is  also  small  (v.  further,  Henderson, 
Proc  Roy.  Inst.  Mech.  Endneers,  1873). 

A  modification  of  this  rnmace  was  patented 
by  R.  &  a  Oxland  (Eng.  Pat.  7285,  1885).  It 
is  so  arranged  that  the  products  pass  into  the 
condensing  chambers  unmixed  with  other  gases. 
At  the  lower  end  of  the  rotating  tube  is  a  cast- 
iron  prdongation,  heated  extemslly  by  a  grate 


m6  a  lyBtem  of  Sdm  •oiroandlns  it.    At  the 
end  of  the  prolongation  ia  a  door  lor  lemoring 


The  praotloe  in  the  Weit  of 
nae  these  types  of  foraooe  for  ipecifio  pnrpoaee, 
the  Oxland  type  for  caJaination  of  selected 
miapioicel  ore,  usnaJly  the  iiae  of  gnvel ;  the 
Bruntoa  and  reTerberatory  type  for  tbe  caloina- 


tion  of  concentrate  prodnced  in  the  washing  of 
the  tin  ocea.  The  small  vorks  fftTonr  the 
roTerbcntoiy  furnace,  and  the  laige  troAa  the 
Brunton.  More  reoentl;  the  Herton  fumaoe 
bM  been  installed  by  a  few  minei.  It  U  mi 
improved   lorm  of  reTerberatory  fnmftoe  with 


Fm.  6.— Gik 


>  Plui  of  E^tbsacb. 


several  hearths  in  ticra  and  mechuiical  rakes 
for  trulsferring  the  material  progresnively  from 
one  hearth  to  another. 

BoMitm  in  muffle  fumaced. — This  process  is 
used  at  Altenberg  (^gs.  4,  6,  and  6)  and  at 
Beichenstein  in  Silesia  (Figs.  7  and  S),  where 
wood  is  cheap. 

The  ore.  reduced  to  a  moderate  size  and 


known  u  tchleidt,  ia  introdaoed  through  an  | 
opening  in  the  top  in  charges  of  about  10  cwt.  I 
uid  ipread  2  or  3  inohes  Uiick  on  the  floor  of  [ 
the  tnnffle.  It  is 
Rnt  heated  to  red- 
neoi,  and  then  more 
genii;,  with  the 
muffle  door  open, 
to  ozidiBe  the  mais 
thoroughly  before 
■ubliniation.  The 
operation  ia  comple- 
ted in  II  or  12  hour*. 
Condauation  of 


These  chambere   i 


cleared  at    iDterrab, 


nanifsne  {MoUaa. 


/&!     oxidt.  —  The 


Fia.  6.— SuBLrMiNa  Fo&sac£. 


vapoura  psaoiug  off  in  the  looating  are  oarried 
through  chambers  so   arranged  t^t  the  [, 
come  in  contact  with  a  7017  lai;ge  oondeoaing 


surface  paasing  through  a  aeriei  of  chambert 
before  escaping  into  the  air.  At  the  Devon  Groat 
Consol*   and   other  large  works,  the  chambers 


Fin.  8. — RncBENSTKiH  FuiisiCBs, 

are  made  of  thin  brickwork  covered  with  iron 

¥late8  to  assist  the  cooling  of  the  gaseous  oxide, 
he  ores,  before  ralninatton,  are  dried  over  iron 
plates  on  the  rnndenspn. 


qnently  used,  so  that  one  set  maj  be  woiking 
while  the  other  is  being  cleared. 

The  oxide  produced  by  all  prooeaaea  exoept 
that  of  the  muffle  is  known  aa  '  arsenioal  soot,' 
and  is  impure,  containing  carbon  and  aulphnr 
compounds ;  when  so  mixed  it  ia  of  a  dark-grej 
ooleur  and  requires  to  be  resublimed. 

The  condensing  chambera  connected  irith 
the  moffles  in  Sikaia  are  In  a  lofty  building 
otdled  the  ■  poison  tower '  {OifttkOnru).  The 
goaes  traverse,  b^  a  sinuous  ooune,  a  series  of 
chambers,  depoeitinx  the  finest  product  in  the 
lovrer  ones,  that  in  ue  upper  chambers  oontain- 
ing  snljAur.  The  chambera  an  cleared  about 
every  2  months,  and  contain  about  26  tons 
of  whit«  arsenic  ('  poison  Sow,'  or  Oiftmehl). 
Being  oomparativelj  pure,  it  does  not  U5u<dl7 
require  refining,  bnt  may  be  at  onoe  oonterted 
into  arsenical  slass.  The  workmen  engaged  In 
oleorJDg  the  chambers  ore  clothed  in  leathern 
garments  with  glaied  apertures  for  the  eyes, 
and  wear  wet  cloths  over  their  mouths  and 
noses  to  absorb  the  irritating  fumeo.  It  i* 
stated  at  Salibnrg  tbat  only  arsenia-eaten ' 
can  perform  this  work  contiouonsly. 

Rejiniiig  or  Ttffiblimation. — For  this  purpose 
a  reverberatory  furnace  is  used,  which  is  usually 
much  shorter  than  that  in  which  the  calcination 
is  performed.  The  arsenical  soot  is  charged 
from  the  top  and  paddled  down  through  doors 
at  the  tide,  more  being  added  as  it  sublimeo. 
The  fuel  need  is  smokuess,  usually  a  mixtui* 
of  anthracite  and  ooke. 

The  sublimate  is  collected  in  ehamboa 
milor  to  those  already  deeoribed.  It  is  whiter 
glistening,  and  minutely  crystalline.  It  is 
ground  between  millstones,  and  is  thence  fed 
mto  k^s  from  a  hopper  through  a  leathern 
hose  which  fastens  to  the  top  of^the  cask  and 
prevent*  any  eseape  of  the  powder- 

Artenie  glau,  or  vitreous  whil«  orvenio,  is 
prepared  by  volatilisation  of  the  powder  under 


slight  preasure.  For  this  purpose,  at  Swansea, 
a  cast-iron  pan  ia  used  2  feet  in  diameter  aitd 
EUriDOuntod  by  a  bell  2  feet  6  inches  high.     The 


a  cherry  red,  and  about  }  e' 
if  reSned  white  arsenic  introduced  through  an 

Kning  in  the  top  of  the  bell,  which  is  then 
ed  with  a  plug.  In  about  2  hours  the  whole 
ivaporated  and  condensed  on  the  bell  as  a 
|>arent  glass ;  more  white  anenio  is  then 
luced  and  condensed,  until  after  24  hours 
the  glass  has  reached  a  thickness  of  about 
1  inch.  The  later  obnrges,  owing  to  the  con- 
densing surface  being  hotter,  require  about  twice 
as  long  to  condense  as  the  first. 

At   Silesia   the  subliming   pots   are  deeper 


ransparent 
itroduced 


ARSENia 


383 


and  of  creator  capacity ;  thoy  are  surmoanted 
by  iron  drumB  and  conical  caps,  which  condense 
the  *  glaoB '  and  open  into  condensing  chambers. 
The  temperature  is  carefully  regubted.  The 
araenio  cImb  produced  amounts  to  about  92  pi  a 
of  the  '  flowers  *  used. 

Analyses  of  Arsenic  Potoder  and  Arsenic  Glass, 

(1)  Powder  from  Altenberg,  from  the  con- 
denser of  a  tin  roasting  furnace,  near  the 
furnace  end  (Lampadius). 

(2)  Do.  from  further  end  of  condenser 
(Lampadius). 

(3)  Do.  from  Oberschlema  (Lampadius). 

(4)  Arsenic  glass  from  Andreasberg  (Streng). 

(1)  (2)  (3)  (4) 

Arsenious  oxide        .  001  96-86  9431  98-2 

ArsenioQB  sulphide  .     2-06  0-32  103  •— 

Bismuth.         .         .      —  —  0-26  — 

Sulphur.         .         .     0-73  0-71  0-60  — 

Ora-dust                   .     6-61  2-06  3  06  — 

Antimonious  oxide  .      —  —  —  1*68 

Properties  and  uses  of  arseniotu  oatide. — 
White  aiaenic  occurs  in  the  amorphous  or  glassy 
form,  and  in  two  crystalline  modifications : 
(1)  the  octahedral  or  common  form,  of  sp.gr. 
3*874  at  0**,  and  (2)  in  trimetric  prisims,  occasion- 
ally found  in  sublimates ;  this  form  is  converted 
into  the  octahedral  variety  when  heated  or 
boiled  in  water. 

fThe  amorphous  form  is  transparent  when 
first  prepared,  but  becomes  opaque  when  exposed 
to  the  air,  especially  when  damp,  diminishing 
sUghtlv  in  sp|ecifio  gravity  and  forming  the 
orystaUine  oxide.  The  action  commences  at 
the  outside,  so  that  .even  after  a  considerable 
time  a  piece  is  frequently  found  with  a  trans- 
parent nucleus.  The  vitreous  form  may  be  kept 
m  a  sealed  glass  tube  unchanged  for  years. 

The  vitreous  form,  aooordmg  to  Buchner,  is 
soluble  in  108  parts  of  cold  water,  whilst  the 
opaque  form  requires  366  parts ;  the  solubility 
ot  an  ordinary  piece  is  therefore  doubtful,  depend- 
ing on  the  amount  of  change  it  has  undergone. 
It  is  very  soluble  in  glycerol,  and  is  stated  by 
Jackson  to  form  glyceryl  arsenite  (Chem.  News» 
49,  268). 

On  making  a  strons  solution  of  the  viireons 
form  in  dilute  hydrochloric  acid  by  dissolvins 
3  parts  in  a  mixture  of  12  hydrochloric  acid 
ana  4  water,  and  slowly  cooling,  it  is  deposited 
in  the  octahedral  form,  each  oratal  as  it  falls 
producing  a  flash  of  light  (H.  Kose).  If  these 
crystals  be  redissolved  or  if  the  opaque  form 
be  used,  no  light  is  produced  on  crystallising, 
that  phenomenon  appearin||  to  depend  on  the 
change  of  the  amorphous  mto  the  crystalline 
form  at  the  moment  of  crystallisation. 

At  about  193^  arsenious  oxide  softens  and 
sublimes  without  fusion  ;  it  fuses  under  pres- 
sure ;  its  vapour  is  colourless  and  odourless. 
It  is  acid  to  test  papers,  but  does  not  appear  to 
form  ttue  arsenious  acid  on  solution  in  water. 

Arsenious  oxide  is  a  powerful  febrifuge,  being 
sometimes  efficacious  when  quinine  has  failed. 
It  is  highly  poisonous,  2  or  3  grains  being  a 
very  dangerous  dose.  When  UBod  habituiuly, 
however,  comparatively  laige  quantities  may  be 
taken  with  impunity,  llie  mhabitants  of  Styria 
eat  it  pnder  the  name  of  *  hydrach,*  to  increase 


their  endurance.  Many  authentic  cases  are 
recorded  of  6  grains  and  upwards  being  taken 
without  ill  effect.  Arsenic-eaters  are  sUited  to 
be  fresh  complexioned,  with  a  tendency  to 
dtoutness,  to  be  long-lived,  but  to  die  suddenly. 
The  workmen  engaged  in  the  manufacture  of 
dyes  where  arsenic  acid  is  used  have  been  ob- 
served to  have  this  tendency  to  stoutness  (v. 
Rosooe,  Mem.  of  lit.  Phil.  8oc.  Manchester, 
1800).  In  cases  of  death  from  poisoning,  the 
greater  part  of  the  arsenic  appears  to  be  con- 
tained in  the  liver  and  intestines ;  of  the  bones, 
those  of  the  pelvis  and  neighbouring  vertebrae 
appear  to  contain  most. 

Arsenious  oxide  is  adsorbed  by  ferric 
hydroxide  under  conditions  which  have  been 
studied  by  Lockemann  and  Lucius  (Zeitsch. 
physikal.  Chem.  1913,  83,  736).  The  total 
adsorption  follows  the  formula  E  =  /9A^  in 
which  £  represents  the  mg.  of  iron  hydroxide^ 
A  the  number  of  mg.  arsenic  per  100  cc, 
and  fi  and  p  are  ooi^tants,  which  differ  for 
different  temperatures.  The  total  adsorption 
is  not  materiiUly  influenced  by  the  presence  of 
sodium  or  ammonium  salts.  The  precipi- 
tation of  arsenic  by  iron  hydroxide  is  a 
usable  process  for  the  purification  of  concen- 
trated salt  solutions,  and  for  the  detection  of 
small  traces  of  arsenic  in  solutions  or  nitre 
fusions. 

In  manufactures,  arsenious  oxide  is  used; 
in  glass-making,  to  remove  the  colour  produced 
by  the  lower  oxides  of  iron;  in  enamelling;; 
in  calico-printing;  as  a  constituent  of  white 
fire  in  pyrotechny ;  for  the  prevention  of  boiler 
incrustations  (40  parts  white  arsenic  to  9  so- 
dium carbonate) ;  in  the  manufacture  of  arsenic 
acid ;  and  of  fly  and  rat  poisons ;  and  in  the 
manufacture  of  a  large  number  of  pigments, 
arsenic  being  found  in  green,  blue,  pink,  white, 
brown,  and  other  colours.  As  a  preservative 
it  is  thrown  into  the  holds  of  ships,  to  prevent 
vegetable  decomposition;  as  a  wash  for  walls 
in  India,  to  prevent  insect  ravages;  to  prevent 
smut  in  wheat ;  and  with  sodium  carbonate  as 
a  wash  for  sheep;  and  in  arsenical  soap,  for 
preserving  skins. 

Arsemous  oxide  is  employed  in  the  fixation  of 
aniline  colours,  especially  of  aniline  blue.  It  is 
used  principally  tor  preparing  steam  colours, 
either  as  a  solution  in  glycerol  containing  4  lbs. 
of  the  oxide  to  1  gallon  of  glycerol,  unoer  the 
name  *  arsenic  ana  glvoerine  standard ' ;  or  as 
sodium  arsenite,  dissolved  in  sodium  carbonate 
or  borate. 

In  medicine  it  is  used  as  Fowler's  solution, 
which  contains  4  grains  of  the  oxide  (in  the 
form  of  sodium  arsenite)  in  each  ounce  of  fluid. 
In  India  it  has  been  used  as  a  cure  for  hydro- 
phobia and  serpent  poisoning.  In  vetorinary 
surgery  it  is  largely  used  as  a  tonic,  to  eradicate 
worms,  and  for  improving  the  coats  of  horses. 

It  occurs,  either  as  an  impurity  or  as  an 
adulterant,  in  a  large  number  of  commercial 
products.  Besides  the  ordinary  commercial 
compounds  in  which  arsenic  is  expected  to  be 
present,  it  has  been  found  in  caustic  soda, 
potassium  chlorate,  commercial  glucose  (QouCt 
and  Ritter),  and  *in  wine  free  from  artificial 
colouring  matter  (traced  to  sulphuric  acid  used 
in  purifying  the  casks).  Dr.  I'idy  found  about 
38  p.c.  of  arsenious  oxide  in  some  *  violet  powder  ' 


384 


ARSENIC. 


which  had  caused  the  death  of  at  least  two 
children  (Lancet,  Aug.  21»  1878). 

In  the  year  1900  occurred  a  serious  epidemic 
of  arsenic-poisoning  due  to  contamination  of 
beer  through  the  use  of  brewing  sugars,  glucose, 
or  '  invert '  sugar  containing  arsenic.  The 
arsenic  was  introduced  by  the  use  of  highly 
arsenical  sulphuric  acid  in  the  production  of 
the  suffars.  The  total  number  of  persons  who 
suJOfered  in  consequence  of  the  epidemic  was  cer- 
tainly 6000,  and  probably  considerably  greater. 
At  least  70  deaths  were  attributed  to  the  epidemic. 

Coal  or  coke  used  for  malt  drying  always 
contains  arsenic;  with  an  ordinary  malt  kun 
part  of  the  arsenic  volatilises  and  may  deposit 
on  the  malt.  Various  methods  have  l>een  tried 
and  adopted  in  which  it  has  been  found  that 
access  of  arsenic  to  malt  may  be  obviated  or 
diminished  (Royal  Commission:  Arsenical  Poison- 
ing, 1903). 

(For  a  statement  of  the  amount  of  arsenic  in 
the  varieties  of  pyrites,  and  of  its  distribution 
in  the  preparation  of  sulphuric  acid  and  alkali, 
V.  H.  Smith,  Phil.  Mag.  [4]  44,  370 ;  Chem.  News, 
26,  176;  and  C.  Hjelt,  Dingl.  poly.  J.  226, 
174-181.) 

Freeenius  finds  that  the  arsenic  in  many 
chemical  glasses  is  removed  by  alkaline,  but  not 
by  acid  liquids ;  the  bearing  of  this  on  judicial 
investigations  is  important. 

The  commercial  article  is  frequently  adul- 
terated with  gyi>sum,  chalk,    &c.,  these   may 
easily  be  detected  by  heating  a  little  on  a  knife, 
when  they   will  remain   after   the   oxide   has 
volatilised. 
Sodium  anenite.    Acid  sodium  arsenite 
Na,0-2AsaO,-2H,0 
is  prepared  by  dissolving  arsonious  oxide  in  a 
solution  of  caustic  soda  or  sodium  carbonate, 
and  evaporating  the  solution.    The  neutral  salt, 
Na^O'AstOs,  is  formed  by  boiling  this  compound 
for   some   time   with   sodium   carbonate,   and 
washing  the  residual  salt  with  alcohol  (Pasteur). 

Potassium  arscnite  is  prepared  in  a  similar 
manner. 

Sodium  arsenite  is  used  as  a  substitute  for 
dung  in  dyeing,  but  is  not  so  reliable  as  the 
arsenate.  It  enters  into  the  composition  of  all 
preparations  in  which  arsenious  oxide  is  dis- 
solved with  sodium  carbonate. 

A  solution  undergoes  slow  oxidation  on 
warming  in  contact  with  air. 

An  arsenite  of  chromium  and  iron  is  used  as 
a  green  pigment  in  wall-papers. 

Scheele^s  green.  Arsenite  of  copper,  Hydro- 
cupric  arsenite.     CuHAsO,. 

According  to  Scheele's  method,  11  oz.  ar- 
senious oxide  are  gradually  added  to  a  solution 
of  2  lbs.  potassium  carbonate  in  10  lbs.  boiling 
water ;  this  is  filtered  and  poured  into  a  solu- 
tion of  2  lbs.  copper  sulphate  in  30  lbs.  water, 
TO  long  as  a  grass-green  precipitate  falls.  The 
precipitate  is  thrown  upon  a  filter  cloth, 
washed  with  warm  water,  and  dried  gently 
with  the  production  of  about  1}  lbs.  of  the 
pigment. 

Scheele*s  green  is  a  pulverulent,  fine  li^ht- 
green  colour,  formerly  largvly  used  in  calico- 
printing  and  for  wall-papers.  It  is,  however, 
much  less  used  at  the  present  time.  It  dissolves 
entirely  in  excess  of  alkali  or  in  acids. 

Schweinfurth  green.    Imperial  green.    Eme- 


rald green.  Mitis  green.  A  ceto-arseniie  of  capper 
(when  mixed  with  gyspum  or  heavy  spar,  known 
also  as  Mountain  or  Neuuneder  green). 

3CuOAs,0,Cu(C,H,0,), 

Five  parts  of  verdigris  (basic  copper  acetate) 
are  made  into  a  thin  paste  with  water  and  added 
to  a  boiling  solution  of  rather  more  than  4  parts 
arsenious  oxide  in  50  parts  water ;  the  solution 
is  kept  boiling  during  the  mixture.  If  a  yellow- 
green  precipitate  falls,  a  little  acetic  acid  is  added, 
and  the  solution  boiled  a  few  minutes  longer ;  the 
precipitate  becomes  crystalline  and  soon  acquires 
the  characteristic  green  colour. 

A  very  fine  product  is  prepared  by  the  follow- 
ing method :-— Boiling,  concentrated  solutions  of 
arsenious  oxide  and  copper  acetate  are  mixed  in 
such  proportions  that  equal  weights  of  the  two 
substances  are  present  when  a  bulky  olive-green 
precipitate  falls ;  an  equal  bulk  of  cold  water 
IS  then  added  and  the  mixture  placed  in  a 
flask  which  it  fills  to  the  neck,  thus  preventing 
any  pellicle  which  may  form  on  the  surface  from* 
falling  through  the  liquid  and  causing^  prema- 
ture crystallisation.  The  colour  unoer  these 
circumstances  takes  two  or  three  da3ni  to  perfect, 
the  beauty  of  the  product  being  much  increased 
by  slow  formation.  The  workmen  engaged  in 
the  preparation  of  this  pigment  do  not  appear  to 
be  injured  by  it.  In  cont-act  with  organic  matter 
it  is,  however,  liable  to  change.  By  the  action 
of  damp  and  moulds,  such  as  PenietUium 
brevicaute,  AspergiUi,  &c.,  on  paper  coloured 
with  this  pigment  a  peculiar  odour  is  frequently 
produced,  which  appears  to  be  due  to  the  forma- 
tion of  diethvlcacodyl  oxide  [A8(C,H5),1,0, 
unaccompanied.,  as  formerly  supposed,  by 
arseniuretted  hydrogen  (Klason,  Ber.  1914, 
47,  2634). 

Anenie  oxide.  Arsenic  acid.  Arsenic  pent- 
oxide,  Acide  arsinique,  Arsensaure,  Addum 
arsenicum.    As^Os. 

Produced  when  arsenious  oxide  is  acted  upon 
by  an  oxidising  agent. 

On  the  large  scale  4  parts  white  arsenic  are 
gradually  added  to  3  parts  nitric  add  of  not  less 
than  1-36  8p.gr.  in  a  vat  capable  of  holding 
from  66  to  70  kilos,  of  white  arsenic.  Great 
heat  is  produced  and  the  evolved  fumes  are 
passed  over  coke  moistened  with  water,  whereby 
about  two-thirds  of  the  nitric  acid  is  recovered. 
In  24  hours  a  syrupy  liquid  is  formed,  con- 
taining a  small  quantity  of  arsenious  oxide, 
which  may  be  oxidised  with  a  little  more  nitric 
acid. 

Kestner  performs  the  oxidation  in  large 
glass  Qasks,  the  nitrous  fumes  being  passed 
through  lead  pipes  and  condensed  in  leaden 
chambers. 

Arsenic  oxide  has  also  been  prepared  by 
suspending  arsenious  oxide  in  water,  passing  a 
current  of  chlorine  through  the  liquid,  and 
evaporating  the  solution  thus  produced. 

It  is  a  deliquescent  solid  fusing'  at  a  dull-red 
heat,  of  acid  metallic  taste  and  acid  reaction. 
It  dissolves  in  6  parts  cold  and  in  2  parts  hot 
water.  The  solution  evaporated  in  an  open 
vessel  at  60**,  or  under  increased  pressure  at 
150°,  deposits  crystals  of  the  composition 
3As,Oft,5H,0.     Above  200**  crystals  of  As,0» 


ARSENIC. 


385 


separate.  Concentrated  solutions  crystallising 
spontaneously  or  by  freezing  deposit  the 
hydrate  H^AsO^IH^O,  or  miztares  of  this  with 
3As,Ot,6H,0  (Balareff,  Zeitach.  anoig.  Chem. 
1911,  71,  73).  A  cold,  strong  solution  blisters 
the  skin.  Arsenic  oxide  and  its  salts  are  less 
poisonons  than  the  corresponding  arsenions 
componnds. 

Sodium  arsenate.  Hydrie  di3o£c  arsenate; 
'  Dung  aaU:    Na^HAsOf. 

It  is  prepared  by  saturating  arsenious  oxide 
with  crude  soda  ash,  drying,  and  deflagrating 
with  sodium  nitrate  in  a  reverberatory  furnace. 

Arsenate  of  soda  is  largely  used  in  calico- 
printing  as  a  substitute  for  dung,  its  feebly 
alkaline  properties  rendering  it  useful  for  that 
purpose. 

ArsenaU  of  iron  is  an  amorphous  green 
powder  containinff  33*6  p.c  arsenio. 

Anenle  snlphldes.  Arsenic  forms  three 
well-defined  sulphides,  As^Ss,  AsaSs,  and  As^^* 
the  two  former  occurring  naturally.  A  liuge 
number  of  other  sulphides  of  indefinite  com- 
position also  exist. 

Anenie  dtedphide  or  Realgar.  Rvihy  sul- 
phur.  Bothes  BausehgeBf.  Boihea  Sehwefel. 
Sidphuri  rouge.  Orpin  rouge.  EisigcMo. 
Sandaraea.    A8,S,. 

Prepared  by  fusing  together  arsenio  and 
sulphur  or  orpiment  in  the  proper  proportions. 
On  the  large  scale  it  is  obtamea  by  distilling  a 
mixture  of  arsenical  ores,  such  as  arsenical  and 
iron  pyrites,  with  sulphur  or  with  the  sulphide 
of  arsenic  precipitated  in  the  purification  of 
sulphuric  acid. 

The  mixture  should  contain  about  15  p.o. 
arsenic  and  26>28  p.o.  sulphur ;  it  is  placed  in 
flask-shaped  earthenware  retorts,  holding  about 
60  lbs.  when  two-thirds  full,  which  are  connected 
with  similar  receivers.  The  retorts  are  gradually 
heated  to  redness  and  kept  so  for  8-12  hours. 
The  crude  realgar  should  be  compact,  dark, 
and  rich  in  arsenic ;  if  sulphur  be  m  excess  it 
is  friable  and  light  red.  It  is  re-melted  rapidly 
in  cast-iron  pans  with  the  requisite  amount  of 
sulphur  or  arsenic,  or  with  realgar  of  poorer 
quality.  The  mass  is  cleared  of  slag  emd  heated 
tmtil  quite  fluid,  and  until  a  small  quantity 
shows  the  proper  appearance  on  cooling.  It  is 
then  poured  into  comcal  sheet-iron  momds. 

Greater  care  is  necessary  in  the  preparation 
of  realgar  than  of  orpiment,  and  an  assay  is 
frequently  made  to  ascertain  the  exact  propor- 
tions required  before  the  final  melting. 

It  is  hard  and  brittle,  generally  opaque,  with 
vitreous  conchoidal  fracture,  orange  or  hyacinth 
red  in  mass  and  orange-red  in  powder.  Its 
sp.gr.  is  3*4-3*6,  and  its  usual  composition 
ia  arsenic  76,  sulphur  26.  It  volatilises 
easilv  before  the  blowpipe  with  a  smell  of  garlic 
and  burning  sulphur,  is  msoluble  in  water  or  by- 
droohlojic  acid,  but  soluble  in  alkaline  sulphides. 

Realffar  is  a  constituent  of.  blue  fiA  and  of 
'white  Bengal  fire,'  which  is  used  as  a  signal 
light,  and  consists  of  realgar  2,  sulphur  7, 
potassium  nitrate  24. 

The  finest  variety,  especially  that  which 
occurs  native,  is  used  as  a  pigment  by  artists. 

Arsenic  trisnlphlde  or  Orpiment.    Operment. 
Odbes   BatuehgeA.      BisigaUum.     Auripigmen- 
turn  (of  which  its  usual  name  is  a  corruption). 
TeBow  Sulphide  of  Arsenic.    AsiS,. 
Vol.  L— T. 


This  sulphide  is  formed  as  a  yellow  pre- 
cipitate when  sulphuretted  hydrogen  is  pained 
through  a  solution  of  arsenious  acid  in  hydro- 
chloric acid. 

Precipitated  arsenious  sulphide  is  appiedably 
decomposed  by  water,  and  even  by  aloonol,  with 
formation  of  hydrogen  sulphide.  It  is  also 
attacked  to  a  considerable  extent  bv  dilute 
hydrochloric  acid,  but  the  action  «of  dilute  acid 
or  of  water  is  checked  by  the  addition  of 
hydrogen  sulphide.  The  precipitate  is  apt  to 
contain  arsemc  hydrosulphide  As(SH)„  together 
with  arsenious  oxide  (Schmidt.  Arch.  ^lann. 
1917,  266,  46). 

On  the  Urge  scale  it  is  prepared  by  subliming 
sulphur  with  arsenious  oxide,  2  parts  of  arsenious 
oxide  and  1  part  sulphur  being  a  common  pro- 
portion ;  the  colour  of  the  product  ia  lighter  wnen 
less  sulphur  is  used. 

According  to  B.  Wagner,  a  very  fine  colour 
may  be  prcduoed  as  follows: — ^2  parts  finely 
ground  bn^um  sulphate  are  calcined  with  1  part 
powdered  charcoal  or  other  carbonaceous  matter, 
and  the  product  is  pulverised,  mixed  with  1  part 

f round  orpiment,  Doiled  in  water  and  filt<ffed. 
'he  solution,  containing  a  sulpharsenite  of 
barium,  is  precipitated  by  the  aadition  of  sul- 
phuric acid.  By  the  addition  of  a  suitable 
amount  of  barium  chloride  before  precipitation^ 
the  pigment  may  be  correspondingly  lightened  in 
colour. 

Orpiment  is  insoluble  in  water  but  very 
soluble  in  alkaline  sulphides.  It  was  formerly 
much  used  as  a  pigment  under  the  name  of 
King's  Yellow,  but  now  is  largely  replaced  by 
chrome  yellow.  The  lighter  varieties  contain 
as  much  as  80  to  90  p.  o.  of  arsenious  oxide, 
and  are  consequently  very  poisonous.  The 
darker  varieties  contain  from  1  p.c.  to  16  p.c.  of 
the  oxide  and  from  0*2  to  3  p.c.  non-volatile 
matter.  It  is  used  in  pyrotechny,  and  the  finer 
kind,  especially  the  mineral,  is  made  into 
pigment  for  artists. 

It  was  formerly  used  as  a  deozidisin^  agent 
in  the  reduction  of  indigo  blue,  and  in  am« 
moniacal  solution  in  silk^yeing.  A  mixture 
of  9  orpiment  and  1  quicklime  made  into  a 
paste  with  water  is  used  under  the  name  of 
Rusma '  for  removing  hair  from  skins,  but  is 
now  generally  xepla<^  by  the  solution^  of 
sulphide  of  lime  prepared  m>m  the  spent  Ume 
gasworks. 

Schultce  (J.  pr.  Chem.  26, 431)  considers  that 
another  form  of  Uie  trisulphide  exists  which  is 
soluble  in  water  (v.  Colloids ).  For  a  description 
of  its  properties,  see  Dumanski,  Zeitsch.  Cnem. 
Ind.  KoUoide,  1911,  9,  262. 

Arsenle  pentasulphlde  As^Sg.  Berzelius  in 
1826  stated  thi^t  this  compound  was  formed  when 
sulphuretted  hydrogen  is  passed  through  a 
moderately  concentrated  solution  of  arsenic  acid, 
but  the  precipitate  was  ^renerally  considered  to 
be  a  mixture  of  the  tnsulphide  and  sulphur. 
Bunsen  in  1878  showed  that  it  was  produced  on 
passing  a  rapid  current  of  sulphuretted  hydrogen 
througn  a  hot  hydrochloric  acid  solution  of  an 
alkaline  arsenate,  and  his  results  were  confirmed 
by  McCay  in  1887  (c/.  Brauner  and  Tomi^ek, 
Chem.  Soo.  Trans.  1888,  147;  Travers  and 
Usher,  Chem.  Soc.  Trans.  1906,  87,  1370 ;  and 
Foster,  J.  Amer.  Chem.  Soo.  1916,  38,  62). 

Arsenic  pentasulphlde  is  totally  insoluble  in 


Sg6 


ARSENIC. 


water,  alcohol,  or  disulphide  of  carbon.  The 
dry  substance,  on  rubbing  in  a  mortar,  becomes 
strongly  electrical. 

Aisenle  chloride.  BiUter  of  arsenic.  Caustic 
oil  of  arsenic  AsGlg  is  produced  by  the  action 
of  chlorine  on  arsenic ;  by  distilling  arsenic 
with  mercuric  chloride;  by  heating  dry 
arsenious  oxide  with  sulphur  monochloride  at 
100''-125'' :  As40«+6S,Cf,=4A8a,+3SO,+9S, 
and  by  distilling  arsenious  oxide  with  stifong 
hydrochloric  acid.  It  is  a  colourless,  oily  liquid, 
of  sp.gr.  2-205  0^4°  boiling  at  130-2°  (Thorpe). 
A  solution  of  arsenious  oxide  in  strong  hyoro- 
chloric  acid  loses  arsenic  on  evaporation,  but 
unless  concentrated  the  loss  by  Tolatilisation  is 
small.  A  N/\0  solution  of  arsenious  chloride, 
N/l  as  regards  acidity,  may  be  concentrated 
to  hfdf-bulk  without  loss  of  more  than  one- 
thousandth  part  of  the  arsenic  present. 

Araenio  ul-lodlde  forms  garnet  to  scarlet- 
red  hexagonal  crystals :  obtained  by  mixing 
arsenious  oxide  with  iodine,  and,  after  standing, 
extracting  with  carbon  disulphide. 

The  chlorid'  and  iodide  are  used  to  a  slight 
extent  in  medicine.  H.  W.  H. 

ARSENICALS,  ORGANIC— His  to  bic  a  l. 
The  study  of  organo-arsenical  compounds  dates 
from  the  discovery  of  '  Cadet's  fuming  arseni- 
cal liquid,'  a  compound  with  an  intolerable 
stench,  and  the  singular  property  of  spon- 
taneous inflammability  in  air  at  ordinaiy  tem- 
peratures to  which  L.  C.  Cadet  de  Gassicouft 
refers  in  his  memoir  on  the  production  of  sympa- 
thetic inks  published  in  1760.  This  liquid 
formed  the  distillate  when  equal  parts  of  arsen- 
ious oxide  and  potassium  acetate  were  heated 
in  a  class  retort.  Guyton  de  Morveau,  Morel, 
and  Durande,  who  worked*  in  Dijon,  confirmed 
this  discovery  about  eighteen  years  later,  and  in 
1804  Th6nard  published  further  reeearches  on 
the  liquid  (Ann.  Chim.  Phys.  30  Vend^miaire 
An.  xiii.  1804,  62,  64),  coming  to  the  conclusion 
that  the  product  was  a  complex  acetate  con- 
taining arsenic.  The  next  important  contribu- 
tion to  the  subject  was  made  in  1837  (Pogg. 
Ann.  1837,  40,  219  ;  42,  145 ;  t;.  Annalen, 
1837,  24,  27;  1839,  31,  175)  when  Robert 
Wilhelm  Bunsen  commenced  his  classical 
researches,  which  were  carried  on  for  a  period 
of  six  years.  He  showed  that  the  distillation 
product  of  arsenious  oxide  and  potassium  acetate 
contained  the  oxide  of  an  arseniuretted  radical, 
a  group  containing  arsenic,  carbon,  and  hydrogen 
which  remained  unchanged  in  composition 
when  the  oxygen  was  replaced  by  the  halogens, 
sulphur  or  cyanogen.  At  first  Bunsen  supposed 
that  the  product  contained  no  oxygen,  and  was 
CaHsAs,  and  as  this  formula  represents  alcohol 
in  which  oxygen  is  replaced  oy  arsenic,  he 
adopted  the  name  Alkarsin  for  the  supposed 
arsenical  analogue  of  alcohol.  Berzelius  sue- 
gested  the  presence  of  oxygen  in  Bunsezrs 
Alkarsin  '  (t.e.  the  original  distillate),  and  gave 
the  name  Kakodyl  (Gr.  kakos-odyl)  to  the  com- 
pound radical  which  functioned  as  a  *  compound 
element '  in  the  series  of  reactions  of  *'  alkarsin.* 
It  is  now  evident  that  the  distillate  dealt  with 
by  the  early  workers  must  have  contained, 
according  to  experimental  conditions,  varying 
amounts  of  cacodyl  oxide  and  cacodyl,  and  this 
would  account  for  the  lack  of  uniformity  in  the 
interpretation    of   the   results   and   for   some 


temporary  confusion  in  nomenclature.  Further 
systematic  investigation  by  Bunsen  (Annalen, 
1841,  37,  1-57 ;  1842,  42,  14-46  ;  1843,  46, 
1-48)  showed  that  the  main  constituent  of 
Cadet's  liquid  is  tocodyl  oxide,  which  he  was 
able  to  prepare  in  a  pure  state  (*  paraoaoodyl ') 
by  the  hydrolysis  of  cacodyl  chloride  with 
potassium  hydroxide.  He  also  oxidised  cacodyl 
oxide  further  to  cacodylic  acid  (alkaigen),  and 
finally  he  isolated  the  radical  cacochrl  itself. 
The  inner  structure  of  the  cacodyl  radical  was 
not  investigated  by  Bunsen,  but  Frankland, 
Kolbe,  and  others  have  since  shown  that  the 
radical  may  be  regarded  as  tervalent  arsenic 
associated  with  two  methyl  radicals.  The 
cacodyl  radical  is  As(CH,)„  and  in  the  free 
state  this  univalent  complex  doubles  on  itaelf 
to  give  cacodyl  As,(CH,)4.  Cacodyl  oxide  and 
cacodyl  chloride  have  the  structures : 

CHj.^'^^^^^^^^^-v.CH,     CH,^^®^^* 

Arsenical  compounds  containing  aromatic 
radicals  were  first  investigated  by  B^shamp 
(Compt.  rend.  1860,  50,  872 ;  51,  350 ;  1863, 
55,  1172),  who,  studying  the  oxidising  action 
of  arsenic  acid  on  aniline  {cf.  Magenta),  noted 
that  a  colourless  condensation  product  could  be 
obtained.  This  substance  functioned  aa  a 
monobasic  acid,  and  Bdchamp  assumed  that 
the  compound  was  an  anilide  of  ortho-  arsenic 
acid  C,Hb'NH-AsO(OH),. 

Ehrlich  and  Bertheim  have  since  shown 
(Ber.  1907,  40,  3292)  that  the  product  is  p- 
aminophenylarsinic  acid  NH,*C«H4'AsO(OH)g. 

The  sodfium  salt 

NH,CeH4-AsO(OH)ONa,stH,0 

(a;=2-6  in  various  preparations)  is  the  Atoxyl 
of  therapeutics. 

Ehrhch,  who  observed  that  aromatic  com- 
pounds containing  tervalent  arsenic  as  distinct 
from  the  quinquevalent  Atoxyl  series  had  a 
more  pronounced  action  in  protozoal  diseases, 
now  instituted  very  extensive  researches  which, 
after  605  trials,  culminated  in  the  preparation 
of  Salvarsan,  or  *606,'  in  1910.  Neosalvarsan, 
or  '  914,'  was  discovered  in  1911,  and  both  these 
substances  have  been  highly  successful  in  the 
arsenical  treatment  of  syphilis. 

More  recent  work  has  trended  in  the  direc- 
tion of  increasing  in  these  substances  the* 
trypanocidal  DOwer  and  reducing  toxicity  to 
the  patient.  Uo-ordination  compounds  of  salvar^ 
san  with  heavy  and  noble  metals  have  been 
investigated.  lAiargol,  which  has  met  with 
great  success  in  the  French  Army,  is  a  complex 
of  salvarsan,  silver  bromide,  and  antimony. 
The  preparation  of  primary  arsines  by  Palmer 
and  Dehn  (Ber.  1901,  34,  3594)  has  prompted 
further  researches  on  organo-aisenic  compounds 
of  therapeutic  value.  The  discovery  that  the 
diazo-  reaction  could  be  applied  to  the  synthesis 
of  aromatic  arsenicals  nas  given  a  further 
impetus  to  the  study  of  these  compounds  (Bart, 
D.  R.  P.  250264  ;  Eng.  Pat.  568,  1911). 

Cacodyl  and  its  mobb  impobtant  Dx- 
BiVATivES  (Bunsen,  Annalen,  1842,  42,  14). 

Cacodyl  [As(CH,),]„  Tetrameihyldiarsine,  a 
colourless,  highly  refractive  liquid  with  intoler- 
able   smell;     b.p.    170^;    solidifies    at   -6% 


ARSENICALS,  ORGANIC. 


387 


formine  square  platea ;  yapour  density  7*1 ; 
Bpaiingly  soluble  in  water,  is  prepared  by 
treating  cacodyl  chloride  with  metaluo  zinc  in 
an  atmosphere  of  carbon  dioxide.  It  inflames 
^wntaneoosly  in  air,  giving  carbon  dioxide, 
water,  and  arsenious  oxide.  It  behaves  as  a 
onivalent  or  tervalent  radical  combining  with 
Bolphur  and  the  halogens. 

Eihykacodyl  {Tetradhyldiardne)  [As(0,H5),1, 
an  oil,  b.p.  185^-190°,  is  produced,  together  with 
triethylarsine  As(CtHg)„  o.p.  140°,  by  the  inter- 
action of  ethyl  iodide  and  sodium  arsenide; 
it  yields,  on  oxidation,  diethylarsinic  acid,  a 
soluble  d^rstalline  product  (Landolt,  Annalen, 
1854,  89,  316;  92,  365).  DimethyldiiaoamyU 
cacodyl  (0H,)^8'A8(CbHi,),,  obtained  by  the 
following  general  method  (Dehn,  Amer.  Chem. 
J.  1908,  40,  123) : 

R,AsH+ClAsR',=HCl+RjAs-AsR', 

from  a  secondary  arsine  and  a  secondary  arsenious 
chloride. 

Cacodyl  oxide  [Aa{CB.^)^]fi,  the  main  con- 
stituent of  Cadet^s  Uquid,  is  a  heavy  oil ;  sp.gr. 
1-462/15*';  b.p.  120**;  solidifies  at  -25°; 
yapour  density  7*55 ;  sparingly  soluble  in  water. 
It  IS  prepared  by  distillmg  cacodyl  chloride  with 
aqueous  potassium  hydroxide,  drjring  and  re- 
distilling in  atmosphere  of  carbon  dioxide 
(Baeyer,  Annalen,  1858,  107,  282). 

Cacodyl  chloride  As(0H3),Cl,  colourless  liquid, 
heavier  than  water ;  b.p.  lOO*' ;  vapour  density 
4'56  ;  is  insoluble  in  water.  It  has  a  penetrating, 
stupefying  odour,  and  has  a  marked  irritating 
action  on  the  mucous  membrane  of  the  nose. 

Concentrated  hydrochloric  acid  and  mer- 
curic chloride  are  added  successively  to  Cadet's 
arsenical  liquid,  and  the  resulting  crystalline 
maffma  is  liquefied  by  the  addition  of  more 
hydrochloric  acid  and  distilled.  The  distillate 
containing  cacodyl  chloride  is  purified  by  treat- 
ment with  calcium  carbonate  to  remove  the 
acid,  and  with  anhydrous  calcium  chloride  to 
remove  water. 

Cacodyl  cyanide  As(CH,),CN,  colourless 
prisms  ;  m.p.  33°  ;  b.p.  140°  ;  sublimes  readily 
at  ordinaiy  temperatures  to  an  exceedingly 
poisonous  vapour.  Is  soluble  in  alcohol  and 
ether,  sparingly  soluble  in  water.  It  is  prepared 
by  interaction  between  cacodyl  and  mercuric 
cyanide: 

[Ai(CH,)J,.fHg(CN),=B[g-f2As(CH,),CN 

Cacodyl  sulphide  [As(CH  J  J,S,  colourless  oil ; 
b.p.  well  above  100°;  insoluble  in  water; 
miBcible  with  ether  and  alcohol. 

Cacodyl  dietdpJUde  [As(CH,)J,S„  white 
rhombic  plates;  m.p.  50°.  Cacodyl  cupri- 
sulphide  £rd^,3Cu,S,  lustrous  octahedra. 

Caeodylic  acid,    IHmelhylarsinic  acid, 

As(CH,),OOH, 

(Bnnsen,  Annalen,  1843,  46,  2),  inodorous 
colourless  prisms ;  m.p.  200° ;  very  soluble  in 
water  and  alcohol.  Is  prepared  by  the 
oxidation  of  cacodyl  oxide  with  mercuric  oxide 
under  water.  It  is  venr  stable,  not  decomposed 
by  the  strongest  oxidising  agents  ^  it  forms 
crystallisable  salts,  certain  of  which  have  been 
used  in  medicine,  including  sodium  cacodylate 
KdO,Na,3H,0  (Ph.  Helv.). 

Cacodyl  trichloride  (CH,).AsCl,  (Baeyer, 
Annalen,    1858,    107,   263),   which   crystallises 


from  ether  in  prisms  or  leaflets,  is  very  unstable, 
fumes  in  air,  and  decomposes  at  40°-50°  into 
methylarsenious  chloride  CHj'AsCl,  and  methyl 
chloride. 

Syntheses  of  Alifhatic  Absenicals. 

I.  Interaction  of  an  Alkyl  Hallde  with  an  AUoy 
of  Anenlo  (Cahours,  Compt.  rend.  1859,  49, 
87). 

Methyl  iodide  reacts  at  180°  with  zinc  or 
cadmium  alloys  of  arsenic,  yielding  double 
salts  of  the  formulae  : 

2As(CH,)J,ZnI,  and  2A8(CH,)J,CdI, 
Ftom.    these,    tetramethylarsonium    iodide    is 
obtained  by  treatment  with  caustic  alkali. 

n.  Interaction  of  an  Alkyl  Hallde  with  Elemental 

Aiscnle. 

A  modification  of  the  first  method  by  which 
the  alkyl  halide  and  arsenic  are  heated  together 
in  a  sealed  tube  at  160°-200°  (Cahours,  Annalen, 
1862,  122,  200).  If  amorphous  arsenic  be  used 
the  reaction  may  be  brought  about  at  ordinary 
temperatures  (Martindale,  Congress  of  Applied 
Chemistry,  1909).  In  either  case  a  double  salt, 
eg.  As(CH,)^I,AsI,  is  formed,  and  this,  when 
decomposed  by  caustic  potash,  gives  potassium 
arsenite,  potassium  iodide,  and  tetramethyl- 
arsonium iodide 

UL  Interaction  of  a  MetaUic  Alkyl  with  an 

Arsenic  Halide 

Zinc  dimethyl  reacts  with  arsenious  chloride 
giving  trimethylaraine  (Hofmann,  Jahresber. 
1855,  538 ;  Annalen,  1857,  103,  357). 

Mixed  arsines  may  be  prepared  in  this  way : 
e.g,  dimethylarsenious  chloride  reacts  with  zinc 
diethyl  giving  dimethylethylareine. 

The  Grignard  reaction — a  special  case  of  this 
method — affords  an  important  means  of  pre- 
paration of  organo-arsenic  compounds  (Hibbsrt, 
Ber.  1906,  39,  160).  Arsenious  bromide  treated 
with  excess  of  Grignard  rea{;ent  (magnesium 
methyl  iodide)  yields  Irimethylarsine. 

IV.  Alkylatlon  of  Arsenical  O^qr-  Compounds. 

In  this  process,  due  in  the  first  place  to 
G.  Meyer  (Ber.  1883,  16,  1440),  but  since 
generalised  by  Klinger  and  Kreutz  (Annalen, 
1888,  249,  147),  and  by  Behn  and  McGrath 
(Amer.  Chem.  J.  1905,  33,  138 ;  1906,  28,  351), 
sodium  arsenite  is  treated  with  alkyl  iodide  in 
alkaUne  solution  giving  sodium  alkylarsenate. 

This  synthesis,  unluce  the  preceding  methods, 
which  require  anhydrous  solvents  or  an  inert 
atmosphere,  can  be  carried  out  in  aqueous 
solutions  under  ordinary  atmospheric  conditions. 
Potassium  methylarsinate  is  produced  by 
mixing  together  potassium  arsenite  and  methyl 
iodide  in  aqueous  methyl  alcoholic  solution. 
After  several  days  a  white  precipitate  2As,0s>KI 
is  removed  and  potassium  methylarsinate  is 
obtained  from  the  filtrate : 


KOAs<;^^  +  CH,I 


.••-••« 

^i 


/OK 
CH,— As^O 

\0K 


388 


ARSENICALS,  ORGANIC. 


Dealkylatlon  ot  A'ipbatlo  Anenieals. 


This  process,  originally  due  to  Baeyer 
(Annalen,  1868,  107,  282),  who  confirmed  and 
extended  Bonsen's  work,  is  effected  by  con- 
verting cacodyl  chloride  into  cacodyl  trichloride 
by  direct  addition  of  chlorine  and  by  distilling 
the  trichloride,  when  methyl  chloride  is  elimi- 
nated, and  methylarsenious  chloride  GH,AsCl| 
is  produced.  This  monoalkylated  arsenical 
is  successively  chlorinated  and  hydrolysed ;  the 
final  product,  methylarsinic  acid,  is  a  substance 
of  therapeutic  utility,  having  been  employed  in 
the  form  of  its  sodium  salt  CH,*AsO(ONa)„H,0, 
arrhenal  or  new  cacodyl  (Auger,  Gompt.  rend. 
1903,  137,  925;  Auger  and  BiUy,  ibid.  1904, 
139,  599). 

Aliphatic  Arsenioals. 

Trimeihylarsine  As(CH,)^  liquid ;  b.p.  70°  ; 
Sjrnthesised  by  method  III.  (above).  Is  also 
prepared  by  distilling  tethimethylarsonium 
iodide  A8(0Hs)4l  with  <£y  potassium  hydroxide. 
Tetramethylarsonium  iodide  is  a  solia  crystal- 
lising in  colourless  leaflets,  which  decompose  at 
170°-180^  It  is  synthesised  by.  method  11. 
(above). 

Tetramethylarsonium  hydroxide,  obtained  by 
the  action  of  moist  silver  oxide  on  the  iodide,  is 
a  strongly  caustic  soluble  substance  resembling 
sodium  or  potassium  hydroxide. 

Meihylarainic  acid  CJHs*AsO(OH)t,  anhydrous 
colourless  crystalline  solid ;  m.p.  161°  ;  soluble 
in  water  and  alcohol ;  decomposes  carbonates 
and  forms  an  ammonium  salt.  The  sodium  salt, 
arrhenal  or  new  cacodyl  GHt*ABO(ONa),H,0, 
has  been  used  in  medicine,  as  also  have  sodium 
dimethylarsinate  (sodium  oocodylate) 

(GH,),AsOtNa,3H,0 

and  corresponding  salts  of  magnesium,  iron, 
strychnine,  eaaiacol,  and  antipyrine. 

DimethyMTsine  (GH,)2AsH,  eolourless  liquid 
with  odour  of  cacodyl ;  b.p.  35*6° ;  spontane- 
ously inflammable  in  air  above  10°  (Palmer,  Ber. 
1894,  27,  1378 ;  Dehn  and  Wilcox,  Amer.  Ghem. 
J.  1906,  35,  3). 

Strong  hydrochloric  acid  Ib  dropped  slowly 
on  to  a  mixture  containing  crude  cacodyl  oxide, 
amalgamated  zinc-dust  and  alcohol.  The  dis- 
tillate IB  passed  through  a  water  wash-bottle 
and  a  soda  lime  tube  to  a  condenser  surrounded 
by  a  freezing  mixture  of  ice  and  salt. 

Meihylarsine  GHa'AsHt  (Palmer  and  Dehn, 
Ber.  1901,  34,  3594),  volatile,  colourless,  highly 
refractive  liquid  with  odour  of  cacodyl;  D.p. 
2° ;  very  poisonous,  not  spontaneously  inflam- 
mable ;  practically  insoluble  in  water ;  soluble 
in  alcohol,  ether,  or  carbon  disulphide ;  is  pre- 
pared by  reducing  methylarsinic  acid  with 
amalffamated  zino-dust  and  alcoholic  hydro- 
chlono  acid  with  precautions  similar  to  those 
taken  in  the  preparation  of  dimethylarsine. 

Arsenomethane  (GH^'As  :  As'GH,),  (Auger, 
Gompt.  rend.  1904,  138,  1705),  heavy  yeUow 
oil  with  ffailio  odour;  b.p.  190713  mm.  Is 
prepared  oy  reducing  80<uum  methylarsinate 
with  sodium  hypophosphite  and  sulphuric  acid. 

VOLATILB  AbSENIOAL  GoMPOUNDS  FBOM 

Moulds. 

It  has  been  observed  that  widlpapers  and 
carpets    containing    arsenical    pigments    have 


become  a  source  of  danger  owing  to  the  eivolutioii 
of  volatile  arsenic  compounds  of  a  decidedly 
poisonous  character.  It  is  now  known  that 
the  presence  of  certain  moulds  is  a  necessary 
condition  for  the  production  of  such  gases. 
These  moulds,  the  most  important  of  which  is 
PeniciUium  brevicatde,  evolve  a  volatile  airsenio 
compound  when  cultivated  in  a  medium  con- 
taining sodium  arsenite.  Several  observers 
have  examined  this  phenomenon,  and  P. 
Biginelli  has  ptepaxed  tairly  well-defined  solid 
derivatives  of  the  gas  and  thereby  concludes 
that  the  gas  itself  i^  diethylarsifie  (GsH(),AsH 
(Atti.  B.  Accad.  Lincei,  1900  [v.]  »,  iL  210, 
242),  although  his  results  have  not  yet  been 
confirmed  by  the  isolation  of  the  secondary 
andne  itself. 

Stnthssbs  of  Aromatic  Avsbnioals. 

Two  general  methods  are  due  to  Michaelis^ 
who,^in  collaboration  with  many  pupils,  has 
given  them  a  very  wide  application  (Ber.  1876, 
9,  1566 ;  Annalen,  1880,  201,  184). 

I.  InterMtlon  of  the  Anenle  Halide  wtth  a  Dlaiyl 

Derivative  of  Hereuiy. 

The  mercury  diaryl  derivative  is  prepared 
by  the  action  of  sodium  amalgam  on  the  aryl 
bromide.  The  action  of  the  mercury  diar/l 
takes  place  in  two  stages.  In  the  first,  the 
arylaraenio  dVudide  is  produced,  e.g, 

Hg(G,H,),-f2AsCl,=Hga,-t-2G.H,-AsCa, 

If  the  action  is  carried  further  the  diaiyl 
arsenic  halide  is  formed 

Hg(G.H5),+2G,H8A8Gl,=2(G,Hs),A8a-fHga, 

A  modification  of  this  method  has  been 
employed  (Ber.  1914,  47,  2748),  whereby  the 
arylmercuric  chloride  is  heated  at  100°  with 
arsenious  chloride  with  the  production  of  the 
arylarsenious  chloride. 

II.  Interaetlon  of  Sodium  with  Cbloroaiyls  and 

Anenloas  Chloride  (or  the  corresponding 
bromo-  derivative). 

Tins  process  ia  a  modification  of  Fittig's 
synthesis  of  hydrocarbons,  e,g, : 

AsGl,4-3GeH8-Gl+6Na=6NaCl-fAs(C.H,), 

The  tertiaiy  arsine  thus  formed  readily 
forms  dihalides  which  on  heating  give  secondary 
arsenic  halides : 

(G,H5),AsCl,=C^4-Gl-f(G,H8),A8Cl 

Primary  derivatives  can  be  formed  by  heat- 
ing the  tcstiary  arsine  with  arsenious  chloride 
under  pressure  at  250°;  the  seoondaiy  com- 
pound is  formed  at  the  same  time : 

(C«H5)^4-2AsGl,=3G,H,AsGl, 
2(G,H,)^+AsGl,=3(G.H5)^sGl  (by-product) 

m.  Grlgnard  Reaetion. 

To  the  foregoing  processes  due  to  Michaelis 
thi%  reaction  adds  a  tmrd  method  which  has  been 
applied  with  considerable  success  to  the  synthesis 
of  triphenylarsine  and  its  homologues. 

IV.  Diazo- Synthesis, 

Aromatic  primary  amines  are  converted  into 
the  corresponding  arylarsinic  aoid^  by  treating 


ABSENIGAI^,  ORGANIC. 


889 


the  diaKonimn  salt  or  alkali  diasoozide  with 
aqueouii  sodium  arsenite  with  or  without  copper 
powder  (Bart,  D.  B.  PP.  250264 ;  254345). 

Abomatio  Absikicals. 

Phenylaraenious  chloride  CsHt'AsCl^  (La 
Coste  and  Michaelis,  Ber.  1878,  11,  1883), 
colourless,  highly  refractive  viscous  liquid ; 
b.p.  252*^-254°;  with  pungent  odour,  more 
pronounced  on  warming ;  very  irritating  action 
on  the  skin. 

Ar8encb€$uene  CcHt'As :  As'CcHs  (Michaelis 
and  Schulte,  Ber.  1881,  14,  912;  1882,  15, 
1952),  light  yellow  needles ;  m.p.  196*^ ;  insol- 
uUe  in  wates  or  ether;  sparuurlv  soluble  in 
alcohol;  soluble  in  benzene,  chloroform,  or 
carbon  disulphide.  An  alcoholic  solution  of 
Fbenylarsenious  oxide  is  warmed  with  excess 
of  ciystaUised  phosphorous  acid.  The  pasty 
product  yields  well-defined  crystals  from  boiling 


Pkenylarsinic  chloride  CeH^'AsClf  (Michaelis, 
Ber.  1877,  10,  622),  flattened  yellow  needles, 
in.p.  45° ;  decomj^oses  violently  in  water, 
diEoociates  on  wanmng  into  the  mchloride  and 
free  chlorine,  the  action  being  facilitated  when 
conducted  in  a  stream  of  diy  carbon  dioxide. 
At  150°  it  is  decomposed  completely  into 
chlorobenzene  and  arsenious  chlorioe. 

Phmylarsinic  acid  CeH,'A80(0H),  (La  Coste 
and  Michaelis,  Annalen,  1880,  201,  184 ;  Micha- 
elis, Ber.  1877,  10,  626),  colourless  prisms 
passing  into  IJie  anhydride  at  158°,  soluble  in 
absolute  alcohol ;  very  stable  towards  oxidising  - 
agents;  on  reduction  gives  phenylarsine  {q.v.), 

Diphenylarsenioiis  chloride  {0J3ii)^AaC[  (La 
Coste  and  Michaelis,  Ber.  1878,  11,  1885; 
Annalen,  1880,  201,  215),  well-defined  colourless* 
tabular  crystals;  m.p.  38°-41°  (formerly 
described  as  a  yellow  ou).  Slight  odour,  more 
pronounced  on  warminff.  Vapour  very  irritating 
to  the  skin.  Alkalis  nydrolyse  it  to  diphenyt- 
arsenious  oxide,  crystalline  aggr^ates ;  m.p.  91°- 
92^,  and  this  product  reduc»d  with  phospnorous 
acidfoniishes  phenykacodyl  {Cfii)^'Aa(C^i)i 
dystaliine  mass ;  m.p.  135°. 

Difken^arsinic  acid  (CcHt),AsO'OH,  colour- 
lees  needles;  m.p.  174°.  Sparingly  soluble  in 
cold  water,  ether,  or  benzene,  more  soluble  in 
hot  water  or  alcohol. 

Trivhenylarsine  (CcHs),As  (La  Coste  and 
Mlchaeus,  ^.c),  colourless  plates  from 
alcohol ;  m.p.  58°-60°  ;  b.p.  above  360°  (with- 
out decomposition  in  carbon  dioxide).  Very 
Bolable  in  ether  or  benzene,  sparingly  soluble 
in  alcohol. 

Tr%ph4tnylmethylarsonium  iodide 

(Cja,),As(CH,)I 

pale  yellow  leaflets  from  albohol;  m.p.  176°. 
Soluble  in  alcohol  or  ether,  sparingly  soluble 
in  water. 

Tribeiuyhrsine  AKCHa-C^Ht),  (Michaelis 
and  Paetow,  Annalen,  1886,  233,  60 ;  Paetow, 
Inftug.  Dissert.  Rostock,  1885),  colourless  mono- 
clinic  prisms  from  alcohol ;  m.p.  104°.  Instduble 
in  water,  sparingly  soluble  in  alcohol;  soluble 
in  ether,  oenzene,  atkd  glacial  acetic  acid. 
Oxidised  b^  hot  dilute  nitric  acid  to  arsenic 
and  benzoic  acids.  Obtained,  together  with 
itm  diohloride  and  dibenzylarsinetrichloride,  by 


the  action  of  sodium  on  arsenious  chloride  and 
benzyl  chloride. 

Dibenzylarsinic  acid  (C,HtCH,)^sO'OH 
{ibid.),  leaflets  from  alcohol ;  m.p.  210°,  decom- 
posing at  higher  temperatures ;  sparingly  soluble 
in  ether,  acetone,  or  benzene ;  bitter  salt  taste 
and  very  irritating  effect  on  the  mucous  mem- 
brane 

Beneylarsinic  acid  CeH5CH,A80(OH), 
{ibid.);  Dehn  and  McGrath,  J.  Amer.  Chem. 
Soc.  1906, 28, 354),  colourless  needles ;  m.p.  167°. 

Benzylarsine  CaH.'CHj'AsH,  (Dehn,  Amer. 
Chem.  J.  1908,  40,  113),  light  yeUow  Uquid; 
b.p.  1407260  mm. 

p-Benzarsinic  acid  CO,HC.H4-AsO(OH), 
(Michaelis,  Annalen,  1902,  320,  303;  Ber. 
1915,  48,  870 ;  Sieburg,  Arch.  Pharm.  1916, 
254,  224;  Bertheim,  Ber.  1908,  41,  1854). 
This  is  a  typical  example  of  the  carboxylatcd 
derivatives  which  can  be  obtained  by  oxidising 
arylarsinic  acids  containing  methyl  groups. 
This  acid  forms  colourless  plates,  sparingly 
soluble  in  water,  very  sparingly  so  in  alcohol 
and  glacial  acetic  acid. 

1.  p-Tolylarsinic  acid  (CH,C8H4-A80(0H),) 
is  treated  with  alkaline  potassium  permanga- 
nate in  aqueous  solution,  the  mixture  being 
left  for  some  da^ns,  when  the  filtrate  is  evapo- 
rated to  dryness  after  acidifying  with  acetic 
acid;  the  residue,  extracted  with  alcohol  to 
remove  potassium  acetate,  is  then  decomposed 
by  concentrated  hydrochloric  acid  when  p-ben- 
zarsinio  acid  is  deposited  in  well-defined  crystals. 

2.  Oxidation  of  p-tolylarsinio  acid  by  means 
of  nitric  acid  in  sealed  tube  at  170°  for  three, 
hours  gives  a  good  yield  of  j'-benzarsinic  acid. 

3.  p-Arsamlic  acid  is  diazotised  in  the 
presence  of  cuprous  cyanide,  the  resulting  p- 
cyanophenylarsmic  acid,  beins  hydrolysed  by 
concentrated  potassium  hy£x)xide,  furmshcs 
p-benzarsinio  acid.  Its  isomerides  are  similarly 
prepared. 

Bbtainbs  of  Abomatic  Absenicals 
(Michaelis,  Annalen,  1902,  320,  297 ;  ibid.  1902, 
321,  174). 

Ordinary  naturally  occurring  betaine  has 
the  constitutional  formula: 

and    is    trimethyl    glycine.    Many    analogues 
containing  quinquevalent  arsenic  are  known. 
Trimelhylarsenibemabetaine  (I.) : 

J.  II 

The  hydrochloride  of  the  triethyl  compound 
corresponding  with  -(I.),  which  was  the  first 
arsenical  betaine  to  be  prepared,  is  obtained  by 
oxidising  p-tolyltrimethylarsonium  chloride  with 
alkaline  permanganate. 

TripAenylarsenibelaine  (II.).  The  betaine  of 
the  second  type  is  produced  by  successively 
treating  triphenylarsine  with  chloroacetic  acid 
and  alcoholic  potash.  Both  these  prepaiationa 
have  been  generalised. 

Thb  USB  OF  Oboanio  Compounds  of  Absbnio 
IN  Thbbapbutigs. 
Diseases  of  protozoal  origin,  such  as '  sleeping 
sickness,*  syph&is,  &c.,  do  not,  in  general,  lend 


300 


ARSENICAL8,  ORGANIC. 


themsolvos  to  serum  treatment,  and  certain 
antiseptics  which  are  inimicable  to  the  existence 
of  the  protozoal  parasite  are  quite  as  injurious 
to  the '  tissues  ot  the  more  highly  organised 
'host.*  Nevertheless,  the  protozoa  are  more 
sensitive  to  chemical  treatment  than  are 
bacteria,  which  are  much  more  highly  resistant, 
and  it  has  been  shown  that  it  is  possible  to 
treat  certain  protozoal  diseases  with  antiseptics 
which  react  specifically  with  the  protozoa,  and 
are  yet  comparatively  innocuous  to  the  host. 
The  treatment  of  malaria  with  quinine  is  a 
typical  instance  of  this  method.  With  a  view 
to  their  use  in  this  branch  of  therapeutics, 
oiganic  derivatives  of  arsenic,  as  against 
inoiganic  preparations,  have  been  ezteimvely 
investigated,  and  the  success  which  has  attended 
their  use  seems  to  be  due  in  part  to  their  rela- 
tively low  toxicity  to  the  hieher  organism, 
their  higher  solubility,  which  probably  increases 
their  penetration,  and  their  comparative  sta- 
bility, whereby  only  the  small  fractions  needful 
for  the  destruction  of  the  protozoa  become 
decomposed  in  the  body,  the  remainder  passing 
througn  the  body  unchanged. 

Atoxyl,  8odium-^-arganikUe,  Sjrn.  Arsamin, 
Soamin,  Natrium  arsanUicum, 

O 

II 
NaO—    As— OH 

0 

NH, 

This  salt  crystallises  with  2-6  molecules  of 
water,  according  to  the  solvent  used  in  its 
preparation.  The  corresponding  mercury  salt, 
AayphU,  has  been  used  for  injections. 

i  Aminophenyl'l-areinic    acid     {j^-AreaniUc 
acid) 


NH,<(^~^AsO(OH), 


A  mixture  of  aniline  (186  grams)  and  arsenic 
acid  (140  grams)  is  heated  gradually  to  170''-200'' 
in  a  vessel  fitted  with  an  efficient  stirrer,  the 
temperature  being  maintained  at  190^-200'^  for 
one  to  two  hours.  The  product  rendered 
alkaline  is  distilled  in  steam  to  remove  excess 
of  aniline,  filtered,  and  neutralised  with  hydro- 
chloric acid  when  crude  p-arsanilic  acid  separates 
on  cooling.  The  product  dissolved  in  aqueous 
caustic  soda  is  decolourised  with  animal  charcoal 
and  filtered  into  alcohol  when  sodium  p-arsani- 
late  (atoxyl)  cirstallises.  A  by-product,  sodium 
4  :  4t''diami7io-aiphenylarsinaie  remains  dissolved 
in  the  alcohol  (0.  and  K.  Adler,  Ber.  1908, 
41,  932 ;  Benda  and  Kahn,  ibid.  1674,  2370 ; 
Pyman  and  Reynolds,  Chem.  Soc.  Trans.  1908, 
93,  1184). 

The  foregoing  condensation,  due  originally 
to  Bdchamp  {I.e.),  has  more  recently  been 
generalised  and  extended  to  the  case  of^he 
homologues  of  aniline  containing  a  free  pAra- 
position  with  respect  to  the  amino-  group 
(D.  R.  P.  219210;  Eng.  Pat.  14937,  1908; 
U.S.  Pat.  913940,  1909 ;  Welcome  and  Pyman, 
Eng.  Pat.  855,  1908  ;  Adler,  Ber.  1908,  41,  931 ; 
Benda  and  Kahn,  ibid,  1672).  Aromatic 
primary  amines  substituted  in  the  para- 
position  are  also  amenable  to  the  Bcchamp 
reaction,  but  with  the  exception  of  j^-nitroaniline 


the  yields  of  orthoamino  arsinic  acids  are  small 
(Benda,  Ber.  1909,  42,  3621 ;  1911,  44,  3294 ; 
D.  R.  P.  243693  ;  Eng.  Pat.  29196,  191.1). 

Phenol  and  its  homologues  oontaininf  free 
para-  positions  with  respect  to  the  hyaroxyl 
group  also  undergo  the  B^hamp  condensation 
with  arsenic  acid  with  the  formation  of  p- 
hydroxyarsmic  acids  (D.  R.  P.  205616). 

Ehrlich  and  Bertheim*s  demonstration  that 
atoxyl  was  the  sodium  salt  of  j'-amino-phenyl- 
arsinic  acid  rather  than  the  anilide  of  arsenic 
acid,  and  that  therefore  atoxyl  was  a  true 
organic  arsenical,  suegested  numerous  sisnificant 
possibilities  of  syntheses,  many  of  which  have 
since  been  realised,  the  aim  in  general  bein£ 
directed  to  improvements  in  stability  and 
specific  action.  For  instance,  the  amino- 
group  may  be  acetylated,  benzoylated,  or 
repmced  by  halogen  or  hydroxyl,  or  a  sub- 
stituted  amine  can  be  used  in  the  initial  stage 
of  the  synthesis  instead  of  aniline.  As  an 
example  of  this  procedure  may  be  cited  the 
acetylation  of  atoxyl,  whereby  a  derivative  is 
obtained  which,  while  just  as  toxic  to  trypano- 
semes,  is  more  stable  and  much  less  toxic  to  the 
host  than  atoxyl.    This  derivative : 

CH.CO  NH-/     S  AsO/ 

^^ — ^        \ONa 

is  known  as  araacdin,  or  acetylatoxyl  (containa 
3-4  H,0).  Lai^e  numbers  of  similar  deriva- 
tives have  been  prepared,  some  of  which  have 
assumed  commercial  importance.  Benzenestd-, 
phonykUoxyl,  termed  Hectine,  has  been  employed 
in  therapeutics. 

Phenylglycinearsinie  acid 

AsO<^ 

and  its  homologues  are  less  toxic  than  atoxyl, 
the  glycine  group,  which  resists  hydrolysis  in 
the  oieanism,  bemg  much  more  finmy  attached 
than  the  acetyl  group. 

Atoxyl  is  digested  with  aqueous  chloracetic 
acid  in  a  reflux  apparatus  for  6-8  hours,  the 
crystalline  glycine  derivative  being  freed  from 
unchanged  arsanilic  acid  by  washing  with 
dilute  hydrochloric  acid. 

Other  aromatic  primary  amines  yield  deri- 
vatives analogous  to  those  obtained  from  aniline. 

Sodium  2  -  aminoiolyl  -  5  -  ar&inate,  ^Kharsin,* 
obtained  by  extending  the  Bcchamp  reaction  to 
o-toluidine,  crystallises  with  3^5  H^O. 

Sodium  acetyl'2-aminotolyC5-ar9tn4Ue  *0r8u» 
dan*  (Wdilcome  and  Pyman,  Eng.  Pat.  856, 
1908): 

O.0H 
As<  5  or  7  H,0 

OH.       ^O*^" 
produced  by  acetylating  the  preceding  com- 
pound, has  also  been  used  in  protozoal  diseasea. 

The  fact  that  the  treatment  of  certain 
protozoal  diseases  with  azo-  dyes  has  met  with 
considerable  success  has  led  to  the  attempt  to 
prepare  dyes  from  the  diazotisable  'p-arsanilic 
acid,  and  a  number  of  monoazo-  and  polyazo- 
dyes  have  been  prepared,  which  in  the  main  are 
less  toxic  to  the  host  than  atoxyl  and  more  so 
to  protozoa. 

The  promising  results  arising  from  the  joint 


ARSENICALS,  ORGANIC. 


391 


and  meicurial  treatment  of  syphilis 
suggested  attempts  to  combine  the  beneficial 
effects  in  one  onur,  and  several  derivatives 
have  been  prepared  which  possess  the  antici- 
pated properties  to  a  more  or  less  degree. 

3 : 6-I>Uivdroxvmercim  -  4  •  amii^ophenyl- 
arsinio  acid  and  3-hydroxymerciiri-4-amino- 
phenyl  arsinio  acid  are  two  weU-defined  examples 


NH, 
HOBfe/\HgOH 

0 :  A8(0H). 


NH, 
/NjHgOH 

O :  As(OH), 


The  hydroxymercaric  derivative  of  orsadan 
known  as  *  Byilryl,*  has  also  given  promising 
physiological  tests : — 

CH.CON Hg ^NCOCH, 

HOHgf^CH,     CH,/\HgOH 

HOHgi^  VHgOH 

AsOaNa,  AsOj^a, 

Snetol  is  the  mercury  derivative  of  salicyl- 
4-ar8inio  acid : 

H0/~\A80(0H), 

c5;h 

and  has  been  employed  successfully  in  the 
treatment  of  S3rphili8. 

Tervalent  arsenic  derivatives  are  thera- 
peutically of  greater  value  than  the  corre- 
sponding quinquevalent  derivatives,  from  which 
tney  are  obtained  by  reduction. 

Phenylglycinearsinic  acid  {q.v.)  yields  arseno- 
phenyHglyeine  in  reduction  with  sodium  hydro- 
sulphite.  Its  aodium  salt,  under  the  name 
Spwareyl  (No.  418  in  Ehrlich's  series) : 

As      =     As 


0  0 


COjNaCH.NH  NHCH,CO,Na 

has  been  used,  and  is  a  decided  improvement 
on  atoxyl,  having  less  toxicity  for  the  host  and 
greater  trypanocidal  power. 

Similarly  p-hydroxvphenylarsinic  acid  yields 
p-arsenophenol  on  reouction,  and  the  fact  that 
these  substances  had  been  used  with  good 
results  in  trypanosomiasis  in  mice  led  Ehrlich 
to  prepare  and  examine  many  substances  of 
similar  constitution. 

Salvaraan  (Syn.  Kharnvan,  Arsenobemol, 
Arsenobilhn,  Ehrlich  606).  3  :  Z-'DiaminoA  :  4' 
dihydrox^arsenobemene,  p-hydroxyphenylarsinlc 
acid  is^succeesively  nitrated  and  reduced  with 
alkaline  sodium  hydrosulphite  and  magnesium 
chloride,  two  molecules  of  the  compound  uniting 
in  the  reduction,  according'  to  the  following 
equation : 

OH  OH 


0 


(HKO,) 


AbO(OH), 


As( 


0(0H), 
As 


As 


OX^tOi) 


NH 


OH    OH 


I  The  foregoing  i>-hydroxyphenylarsinio  acid 
is  obtained  either  from  p-arstuiilic  acid  through 
'  the  diazo-  reaction,  by  fx>iling  the  diazo-  com- 
pound with  water,  or  directly  from  arsenic  acid 
and  phenol,  by  extending  the  Bechamp  reaction 
to  the  latter  compound. 

Salvarsan  can  also  be  prepared  by  starting 
from  dimethylaniline.  This  base,  treated  with 
arsenious  chloride,  yields  "p-dimethylamiiuh 
phenylarsenunudichhride,  oxidation  of  the  chlo* 
ride  leads  to  'p-dimdhylanilinearnnie  acid,  which, 
on  nitration,  ^[ives  Z-nitroA-dimeUiylaminO' 
phenylarsinic  actd.  The  nitro-  compound,  on 
wflkrming  with  40  p.c.  aqueous  caustic  soda,  gives 
rise  to  3-nitro-4-hydroxyphenylar8inic  acid, 
which  is  reduced  as  above.  This  nitro-hydroxy 
compound  is  also  obtainable  by  putting  p- 
chloroaniline  through  the  Bart  process  and 
successively  nitrating  and  hydrolysing  the 
resulting  p-chlorophenylarsinio  acid. 

The  crude  moist  preparation  of  salvarsan 
base  is  dissolved  in  methyl  alcohol,  and  its 
dihydrochloride  precipitatea  by  the  successive 
addition  of  methyl  iJcoholio  hydrochloric  acid 
and  ether,  and  is  dried  in  an  inert  atmosphere. 
The  free  base  is  insoluble  in  water  or  in  pnysio- 
logical  salt  solution,  and  it  does  not  form 
neutral  salts,  since  it  is  an  amphoteric  substance, 
being  feebly  basic  and  having  also  phenolic 
properties. 

These  characteristics  constitute  a  drawback 
to  its  utility  for  intravenous  injections  and  in 
practice  the  hydrochloride  has  to  be  very 
carefully  neutralised  immediately  before  use 
by  means  of  sodium  hydroxide. 

There  are  nine  possible  symmetrically 
constituted  isomerides  of  salvarsan,  and  the 
following  five  have  been  obtained  : — 

4 : 4'-diamino-3  :  3'dihydroxyarsenobenzene 
2:2'      „         3:3' 
2:2'      „         5:5' 
4:4'      „         2:2' 
5:6'      „         2:2' 


99 
f» 
ft 


99 


In  no  case  is  the  isomeride  comparable  id 
therapeutic  value  with  salvarsan.  The  methyla- 
tion  of  salvarsan  increases  the  toxicity  of  the 
compound  to  the  host  and  diminishes  the 
trypanocidal  value,  e.g,  the  hexamethyl  deriva- 
tive is  3-5  times  as  toxic  as  the  unmethylated 
compound,  and  is  inactive  with  regard  to  the 

Srotozoa.    Carboxylation  leads  to  similar  ten- 
encies.     Many     other    salvarsan*   derivatives 
have  been  prepared  and  examined. 

Certain  pofyaminoarsenobenzenes  are  already 
of  considerable  therapeutic  importance,  and 
significant  developments  in  this  direction  seem 
likely.  Among  tnese  salvarsan  analogues  the 
following  are  noteworthy  : — 

4  :  V  Dimelhyl'3  :  4  :  5  :  3' :  4' :  5'-h€xamin<h 
araendbenzene 


As 

..0 


NH,\/NH, 
NHCH, 


NH 


As 


.0 


NH, 
NHCH, 


has  low  toxicity  towards  human  beings  and 
high  trypanocidal  powers. 

4  :  4c'-TelrameihyUZ  :  4  :  6  :  3'  :  4'  :  5' 
aminoarsenobenzene 


302 


AKSENICALS,  ORGANIC. 


As 


0 


NH.V^NH, 

.  N(CH,), 


NH 


As 


.0 


NH, 

N(CH,), 


and  the  correepondinff  ethyl  derivatiye  have 
similar  properties.  These  bases  have  the  re- 
markable property  of  diBsolving  in  soluble 
bioarbonates,  giving  rise  to  stable  complex 
carbamates  precipitated  from  aqueous  solution 
by  alcohol  or  acetone. 

Certain  limitations  in  the  usefulness  of 
salvarsan  have  already  been  mentioned.  The 
drug  (dihydrochloride)  does  not  give'  rise  to 
neutral  solutions,  and  accordingly  its  application 
is  lacking  in  simplicity.  The  replacement  of 
an  atom  of  hydrogen  in  one  of  the  amino* 
groups  of  salvarsan  by  a  methylenesulphinic 
group  confers  sufficient  acidity  on  the  mole- 
cule to  enable  soluble  neutral  and  stable 
alkali  salts  to  be  preparod.  The  introduction 
of  the  methylenesu^hinic  group  into  the 
hydrochloride  of  salvarsan  is  brought  about  by 
the  action  of  sodium  formaldehydesulphoxylate 
followed  successively  by  somum  carbonate 
solution  and  hydrochloric  acid. 

Sodium-S  :  ^'-diaminoA  :  4t'-dihydroxy' 
iursendbenzene-N-mdhyleneeulphinate,  Neo-aalvar- 
MYi  is  the  sodium  salt  of  the  acid  thus  produced 


As 


As 


OH  OH 


NHCHjOSONa, 


The  product  is  a  pale-yellow  powder  giving  a 
neutral  aqueous  solution.  Its  curative  effect 
closely  resembles  that  of  salvarsan.  The  phoa- 
vhamic  acid  derivative  of  salvarsan,  first  prepared 
by  Mouneyrat,  is  also  an  acidic  substance 
yielding  neutral  solutions  in  aqueous  sodium 
carbonate.  It  is  known  as  Oalyl  (No.  1116  of 
Mouneyrat*8  series),  and  its  constitution  is  as 
follows  :— 


As 


0 


0 


H0< 
^^-SOjNHX 


'NH      NH' 

OH  \      /      OH 
PO(OH)  ^ 

(4  :  if'Dihydroxyarsenobenzene-^  :  S'-pho9phamic 
acid). 

Ludyl  (*  1151  *  of  Mouneyrat*s  series). 

Bemetve-m-Z'  :  Z'-disulpnamino-bis-Z-aminO' 
4 :  4t'-dihydroxyar8en6benz€ne 

>/"^As :  As/     SOH 
[\ /  N — / 

NH, 

)As :  As/~SoH 

NH, 

a  yellowish  powder  also  resembling  neo-sal- 
varsan  in  its  chemical  properties  and  thera- 
peutic action. 

Co-ordination  compounds  of  metals  with 
arsenoaryl  compounds  were  first  discovered  and 
investigated  by  Ehrlioh,  who  made  known  his 
results  at  the  International  Congress  of  Medicine 
held  in  London  in  1913.    Danysz  shortly  after- 


_S0,NH7 
HO 


wards  made  similar  observations,  and  since  the 
first  communication  was  made  a  very  large 
number  of  these  complexes  have  been  prepared 
and  examined.  The  arsenoaryls  givmg  the 
best  results  so  far  are  arsenobenzene,  salvarsan, 
and  neosalvarsan,  and  of  these  the  copper  co- 
ordination compounds  are  isolated  most  readily, 
whilst  the  silver  co-ordination  compounds  show 
the  greater  promise  in  therapeutics. 

The  most  important  of  these  compounds  so 
far  produced  is  that  derived  from  salvarsan, 
silver  bromide,  and  antimony.  It  is  the  silv.  r 
bromide  antimonyl  sulphate  co-ordination  com- 
pound of  salvarsan  having  the  formula  : 

[Ci,Hx,O,N,As,],AgBr,SbO(H,804)i. 
The  name  Luargol  has  been  given  to  this 
substance,  and  it  promises  to  be  very  efficacious 
in  protozoal  diseases,  having  much  more  marked 
tr^Minocidal  properties  than  salvarsan,  with  no 
increase  in  toxicity.  Luaivol  is  insoluble  in 
water,  and  is  rendered  soluble  by  caustic  soda 
(0*4  gram  of  NaOH  to  1*0  gram  of  drug).  It  is 
preferably  injected  intravenously,  ill-effects  are 
produced  by  subcutaneous  application. 

MiSCBLLANBOnS  ORGANIC  DSBIVAnVES  Off 

Abssnio. 
Dicamphorykursinic  acid 

O 


XH— As- 


— As— CHv 

I    >CbHu 


CO' 


A  condensation  product  of  sodium,  camphor 
and  arsenic  trichloride,  consists  of  colourless 
transparent  prisms ;   m.p.  266®  (with  deoompo- 

sition);   [a]^-f  186*6® ;    practically  insoluble  in 

water  or  petroleum,  more  soluble  in  benzene, 
freely  soluole  in  chloroform  or  alcohol  (Mozgan 
and  Micklethwait,  Chem.  Soc.  Trans.  1908,  93, 
2146;  1909,  95,  1476;  Mozgan  and  Moore, 
Chem.  Soc.  Trans.  1910,  97,  1699). 
Tricamphorylarsinic  acid 


b^-<Z]fZ 


is  obtained  from  the  final  mother  liquors  of  the 
above  preparation  after  systematic  fractiona- 
tion, the  ultimate  product  being  a  brown 
amorphous  solid  very  soluble  in  benzene, 
alcohol,  or  acetic  acid,  and  recovered  from  these 
solvents  as  a  viscid  mass  (Morgan  and  Mickle- 
thwait, {.c). 

Cyclic  derivatives  of  arsenit  have  been  ob- 
tained recently  (Griithner  and  Wiemik,  Ber. 
1915,  48,  1473 ;  1916,  49,  437 ;  Lappe,  BuU. 
Soc.  chim.  1916  [iv.]  19,  151,  290)  by  employing 
the  Grignard  reaction ;  phenylcyclopeniamdht^ 
enearsinc  (I.)  and  methyloycloperUatnethykne' 
arsine  (U.) : 


II. 

Anenioal  derivativea  of  thiophen  may  be 


ARSENICAL8,  ORGANia 


383 


by  the  use  of  organo-meicmy  com- 
ponndB  MB  employed  by  Michaelis  in  his  eailier 
work  (Michaelis,  ArnuJen,  1880»  201,  196; 
1902,  320.  272). 

Tkienyiarsatiaiu  eUonde  (L),  DiUuenyl' 
arsauous  ckhride  (IL ),  and  Triihitnf^sine  ( IIL ): 

CH— CH  rCH— CHl 

I!         II  II       II 

CH     CAsCl,  ICH    C-  A^a 

\s/  L\s/  J. 

L  n. 

rCH— CHn 

II         II 

CH     C—  IAb 

L\s/    J. 
in. 

are  obtained  as  suooessiye  fractions  from  the 
filtrate  when  arsenioiis  chloride  and  mercuri- 
dithienyl  are  allowed  to  react  under  carefolly 
regulated  conditions  (Steinkopf,  with  Baner- 
meister,  Annalen,  1917,  413,  331). 

This  reaction  was  first  studied  by  Finze  and 
Furiotti  (Gazz.  chim.  ital.  1915  [iL]  45, 280,  290 
who  ozidiaed  the  two  chloro-  compounds  to  the 
corresponding  ihieHt^ainic  and  dtAienylarsinic 
acids. 

Strontium  eMhrocursindbehenolaU 
8r(C„H,,0,Asa>|, 

a  colouriess  amorphous  precipitate  introduced 
into  pharmacy  unoer  the  name  of  Elaraon,  and 
givinff  good  clinical  results  in  anmmia,  is  pre- 
parecf  by  heating  together  behenolic-acid  and 
arsenious  chlori£  at  140°,  the  addiUve  com- 
pound being  then  treated  successively  with 
aqueous  caustic  alkali  and  methyl-alcoholic 
strontium  chloride  containing  ammonia.  In 
this  process  arsenious  chloride  is  added  to  the 
triple  linking  of  behenoUc  acid  (£.  Fischer, 
Annal^  1914,  403,  109): 

"^         l"l         ^        i"l 

a  Asa,         ci  Aso 

Proidn  eambifuUiona  containing  arsenic. — 
Insolnble  combinations  containmg  firmly 
attached  arsenic  which  does  not  give  the 
ordinary  analytical  reactions  of  the  element 
are  produced  by  dissolving  albumin  from  white 
of  ^gg  in  acetic  anhydride,  and  by  adding 
Buccessively  to  the  solution  phosphoric  anhydride 
and  arsenious  chloride.  The  protein  precipitate 
is  freed  from  phosphoric  and  arsenious  acids  by 
washing  with  water  (Guezda,  D.  R.  P.  201370). 

Arsenical  preparations  insoluble  in  the  aaa- 
trie  juices  are proauced  by  adding  arsenious  cmor- 
ide  to  gliadin  or  glutenin  suspended  in  alcohol. 
The  fiiud  product  is  soluble  m  hot  water  and 
contains  4'3  p.c.  of  arsenic  (I).  R.  P.  214717). 

Soluble  stable  combinations  of  salvarsan 
base  and  proteins  have  been  recommended  for 
use  in  ihenpeutics  (D.  R.  P.  261542) ;  they  are 
prepared  by  diBsolving  in  alkali  the  additive 
compounds  of  salvarsan,  and  the  alkali  salts  of 
lysalbic  and  protalbic  acids  or  similar  protein 
acids.  The  reacting  alkali  salts  are  precipitated 
by  alcohol-ether  or  obtained  by  concentration 
invacftS, 

Tri  Usb  or  OBOAinc  Absbnicalb  ik 
Chbmical  Wakfabb. 

The  o  1  anio  arsenicals  chiefl}'  employed  in 
the  chemical  offensive  of  the  Great  War  were 


aix>matic  arsenicals  containing  tervalent 
ar8:>nic  These  compounds  had  very  disagree- 
able physiological  properties  and  function^  as 
lachr3rmators,  stemutaton  and  respiiatoiy 
irritants.  Dipken^kwsenioms  dUoride  {diphen^' 
ckioroarsine)  possessed  these  irritating  properties 
in  a  yeiy  marked  degree.  It  was  prt^paied  for 
this  purpose  by  heating  triphenylarane  (2  molsJ 
and  arsenious  chloride  (I  moL)  at  300**  in  auto- 
davea.  The  by-product  of  this  reaction,  pAenyl- 
orsemiouB  chtondle^  was  also  a  respiratory  irritant 
and  had  a  vesicating  action  on  the  skin.  It 
was  separated  by  fractional  distillation  from 
diphenylarscnious  chloride. 

Alternatively  phcnylarsinic  acid  was  pre- 
pared from  sodium  arsenite  and  benienedia- 
zonium  chloride  in  presence  of  copper  sulphate 
(Bart  8  reaction\  This  acid,  reduced  with 
sulphuroos  acid  in  the  presence  of  hydrochloric 
acid,  gave  rise  to  phenyiar*enious  chloride.  The 
latter  compound  dissolved  in  aqueous  sodium 
hydroxide  and  treated  with  benzenediaionium 
c^oride  fumiahed  diphenylat'sinic  acid,  which 
on  reduction  with  sulphurous  and  hydrochloric 
acids  yielded  diphenylarscnious  chloride.  The 
overall  yield  by  uieso  procesaei  varied  between 
24  and  36  per  cent.  The  foregoing  repetition 
of  the  Bart  reaction  was  avoided  by  a  combina- 
tion of  the  Michaelis  and  Bart  method  leading 
to  diphenyl-arsenious  chloride  when  triphenyC 
arsino  is  heated  to  300''  with  pbenylaiscnious 
chloride. 

Diphenylarsenious  cjfanide  (C^HJaAsCK,  of 
whioh  large  quantities  were  emploved  in  the 
later  stages  of  the  war,  was  mannmctured  by 
digesting  diphenyltfsenious  chloride  with  a 
warm  concentrated  aqueous  solution  of  sodium 
or  potassium  cyanide.  It  was  obtained  in 
colourless  crystals  melUng  at  31**. 

The  aromatic  arsenicc^  containing  quinque- 
valent  arsenic,  such  as  triphenylarsine  diohlonde, 
when  yapourised  by  heat,  behaved  as  ster- 
nutatois  and  respiratory  irritants;  but  this 
effect  was  probacy  due  to  the  formation  of 
compounds  of  tervalent  arsenic  akin  to 
diphenylarBcnious  chloride.  The  corresponding 
organic  antimoniaJs,  although  irritant  and  lethal, 
offered  no  advantages  over  the  aromatic 
arsenicals. 

The  aliphatic  arsenicals  of  the  cacodvl  an\l 
alkyl  arsenious  chloride  series  were  found  to  be 
respiratory  irritants  and  lethal  agents,  methyl- 
arsenious  chloride,  ethylarsenious  chloride  and 
cacodyl  cyanide  being  among  the  most  toxic. 
Methylarsenious  chloride  was  manufactured  in 
America  by  methylatin^  sodium  arsenite  with 
dimethyl  sulphate,  reducmg  the  resulting  sodium 
methylarsinate  to  methylarsenious  oxide,  and 
treating  this  oxide  with  hydrogen  chloride. 
Ethylarsenious  chloride,  manufactured  atHoohf>t 
and  Ludwigshafen,  was  prepared  by  a  similar 
series  of  processes,  starting  from  sodium  arsenite 
and  ethyl  chloride  (Joum.  Indust.  Engin.  Clem. 
1019,  11,  105,  826).  But  on  the  whole  these 
aliphatic  derivatives  were  not  more  effective  in 
producing  casualties  than  the  above-described 
aromatic  arsenicals. 

Bibliography. — Organic  Compounds  of  Ar- 
senic and  Antimony,  G.  T.  Morgan.  London. 
1918.  Handbuch  der  Grganisohen  Arsenverbin- 
dungen,  A.  Bertheim.  otuttgart.  1913.  Die 
Aromatische  ArsenverbinduugeUf  ^*  Schmidt. 


394 


ARSENICALS,  ORGANIC. 


Berlin.  1912.  Dir  Arzneimittel  Synthese,  S. 
Fraenkel.  Berlin.  1912,  663.  Saivarsan  or 
*  606  '  (Dioxydiaminoarsenobenzol).  Its  Che- 
mistiy,  Pharmacy,  and  Therapeutics.  (W.  H. 
Martindalc.  London.  1911.)  Ghimie  et  toxi- 
oologie  de  rarsenic  et  de  ses  composes.'  A 
Valenre.     Paris.    1904.  G.  T.  M. 

ARGATOXYL.  Silver-^^-aminophenyl  arse- 
nate. 

ARGOCHROM.    Silver  methylene  blue. 

ARSALYTE.  Dimethyl  amino  tetramido 
arsenobenzene. 

ARSAMINAL.    Japanese  name  for  saivarsan. 

ARSENICAL  PYRITES  or  Arsenical  mundic 
Names  commonly  used  by  miners  for  the  mineral 
miapickd  {q.v,)  or  araenopffriu  (FeAS),  which  is 
the  principal  ore  of  arsenic. 

ARSENIC  MOULD.  PeniciUium  brevicauU. 
This  organism,  first  obtained  bv  Gosio,  in 
presence  of  an  arsenic  compound,  forms  diethyl- 
carsine  AsH(CgHt),,  to  which  the  poisonous  gas 
developed  by  wall-papers  containing  arsenic  is 
probamy  due.  The  formation  of  diethylarsine 
by  the  action  of  this  mould  has  been  used  as  a 
test  for  arsenic  by  Markmann  (Chem.  Zentr. 

1900,  ii.  1187);  Galli-Valerio  and  Strzyzowski 
(ibid,  1901,  i.  63). 

PeniciUium  hrevieavJe  also  gives  garlic  or 
mercaptan-like  odours  with  compounds  of 
selenium  and  tellurium  (Maassen,  Chem.  Zentr. 
1902,  i.  1245). 

ARSENOFERRATIN.  Sodium  arsenoferri- 
albuminate. 

ARSENOGENE.  Trade  name  for  an  albu- 
minous preparation  of  arsenic  and  iron  obtained 
by  heating  peptonised  casein  with  arsenic  acid 
and  ferric  ammonium  sulphate.  Used  in  medi- 
cine (Salkowski,  Apoth.  !4it.  1908,  23,  114). 

ARSENOPYRITE  v.  Misfiokel. 

ARSENOTRIFERRIN.  Iron  arseno-p- 
nudeinate. 

ARSEN-PHENOLAMINE,  Syn.  for  saivar- 
san.   See  Absenioals,  Oroanio. 

ARSINE.    Arsenic  trihydride  (v.  Arsenic). 

ARSINOSOLVINE.  Sodium  salt  of  amino- 
phenylarsenic  acid. 

ARSFHENAMINE.  U.S.  Pharm.  title  for 
saivarsan. 

ARTARINE  C,iH„O.N,  m.p.  240°,  is  an 
amorphous  alkaloid  from  Ar i  ar-root  of  Xanthoxy- 
km  senegalense.  The  hydrochloride  B,HC1,4H,0 
forms  yellow  needles,  very  little  soluble  in  water 
(Giacosa  and  Soave,  Gazz.  chim.  ital.  1889,  19, 
303). 

ARTEHISIN.  An  alkaloid  isolated  by  Merck 
'  from  the  mother  liquors  obtained  in  the  prepara- 
tion of  santonin  from  the  seeds  of  Artemisia 
maritima.  Forms  colourless  crystals;  m.p. 
200** ;  sparingly  soluble  in  water,  more  soluble 
in  alcohol;  [a]  —  84*3^    With  hot  soda  solution 

gives  a  carmine-red  solution,  colourless  on 
ooolinff.  Gives  an  oxime  with  hydroxylamine, 
andTanydrazone  with phenylhydrazine  (Bertolo, 
Pharm.  J.   1902,  489;    Freund  and  Mai,  Ber. 

1901,  3717;  cf,  Wedekind  and  Koch,  Ber. 
1906,  1846)  {v.  Santonioa). 

ARTERENOL.  Trade  name  for  o-Dihy drozv  • 
phenylaminomethyl  carbinol  hydrochloride. 
r.  Adrenaline. 

ARTICHOKE.  Three  v^etables  are  known 
by  this  name:  (1)  the  Globe  artichoke — the 
flower  head  of  Cynara  acolymua ;  (2)  the  Jeru- 


salem artichoke — the  tuber  of  Helumthus 
tvberosus ;  (3)  the  Japanese  or  Chinese  artichoke 
—called  also  Chorogi — the  tuber  of  Stachys 
tvberifera. 

The  following  are  analyses  of  the  tubers  of 
the  two  latter : — 

Carbo- 
Water  Protein  Fat  hydrates  Ash 
Jerusalem  arti- 
choke      .         .  79-6     2-6     0-2     16-7    lO 
Stachys  tuberifera   7806  4*32  016   14-63  1-21 

(Strohmer  and  Stift,  Bied.  Zentr.  21, 820.) 

The  *  protein'  of  the  Jerusalem  artichoke 

includes  much  material  other  than  true  proteid ; 

the  carbohydrates  consist  largely  of  inulin  and 

levulin. 

According  to  Tanret  (Compt.  rend.  1893, 117, 

60),  two  other  carbohydrates — helianUienin  m.p. 

176*,  12C|HioO,+3H,0,  and  synanihrin,  m.p. 

170*,  8CfH2oOs+H,0---aTe  also  present,  and  the 

levulin    or    synanthrose    described    by    other 

observers  as  occurring  in  artichokes,  is  a  mixture 

of  saochaiose  and  synanthrln. 

The  tubers  of  Stachys  tuberifera  contain  many 

nitrogenous  substances  of  an  amide  nature-— 

glutamine,  tyrosine,  arginine,  ckoUne,  triganelUnep 

and  the  cha^aoteristio  body,  stachydrine 

C,— CH— COv 
,— N(CH,),/ 

The  amount  of  the  last-named  is  estimated  at 
0*18  p.0.  of  the  dry  substance  (Schulze  and 
Trier,  Zcitsoh.  physioL  Chem.  1910,  67,  69). 
The  characteristic  carbohydrate  is  stachyoae 
Ci.H„0,g,3H,0  iq.v.),  H.  L 

ARTOCARPUS  BARK.  The  mner  bark 
(bast)  of  the  bread-fruit  tree  [A,  incisa  (Linn.)] 
is  used  by  the  South  Sea  Islanders  for  making 
ropes  and  clothing.  According  to  Moeller 
(Dingl.  poly.  J.  231,  463),  this  fibre  would  pro- 
bably be  a  very  useful  one.  It  can  be  obtamed 
in  large  quantities. 

ARTOCARPUS  INTEQRIFOLIA  (Linn.  f.). 
(Jack  Tree)  v,  Jaoxwood  ;  Dtss,  Natubau 

ARUM  MACULATUM  (Lmn.).  The  common 
amm,  *  wake  robin,'  or  '  lords  and  ladies,' '  cows 
and  calves,'  formerly  known  as  '  abron '  janus, 
*  ramp,'  *  starch  wort,'  contains  a  starch  which 
was  made  into  a  kind  of  arrowroot  in  the  Isle 
of  Portland,  and  was  the  active  ingredient  of 
'  Portland  powder,'  a  so-called  specific  for  gout. 
Ocoasionallv  sold  in  Paris  as  a  cosmetic,  under 
the  name  oipoudre  de  Cypre. 

AmorphaphaUus  eampanulahu  (Blume)  is 
used  in  India  as  a  vegetable  and  also  in  medicine, 
as  are  other  of  the  Arums.  Many  of  the  Aroiden 
act  as  poisons,  their  toxic  action  being  due 
apparently  to  the  irritation  induced  by  the 
raphides  contained  in  the  cells  (Pedler  and 
Warden,  Jour.  Asiatic  Soc.  of  Bengal,  67,  2, 
106 ;  Stahl ;  Pflanzen  und  Schnecken,  Zeitach. 
Nat.  u.  Med.  Jena,  xxii.  N.  F.  xv.  1888). 

ASAF(ETIDA  v.  Gum  Bxsms. 

ASAPROL  V,  Abbastol. 

ASARUM  CANADENSE  (Linn.).  A  plant 
indigenous  to  North  America,  where  it  is  known 
by  the  names  of  'Wild  Ginger,'  or  *  Canada 
Snake-root.'  The  rhizome  yields  on  distillation 
an  essential  oil  used  in  perfumery,  containing  a 
phenol  C,H„0„  d-  and  ^  pinene,  (Minalool, 
-bomeol,  ^terpineol,  geraniol,  eugengl  methyl 


„,  _     ..    .._d  acetic,  and  k  blui 

oil  of  nndetenDined  oorapoaitioii,  conaiatitig  of 
oijgMMtted  rabstancos  of  alcohi^  natnni 
(Poirar  and  Scad,  Chem.  Soc.  Tniu.  J902, 
Bl,  69). 

ASBABO.  Aaba/g  consists  at  tfaa  dried 
flomia  Mid  flowering  stoma  of  the  Dtlpkiniim 
taM,  which  is  found  in  great  qnantity  in  A^haoi- 
■tan.  The  dycatoff  is  colkctod  and  taken  to 
Jfnltan  and  oUier  Punjab  towns,  Irom  which  it 
it  oonTeyttd  aU  orec  India.  It  is  or  waa  mnoh 
used  in  silk-dTeing  for  the  prodaction  of  a 
■nlphnr-ydlow  ooloni  known  as  '  gaadkaki,' 
•nd,  together  with  DalUca  eoHnabimi,  to  obtain 
a  fiMfifr  ahade  m  almn-DioitlanCed  w*^^  ;  it  is 
also  need  in  ealieo-ptinting.  The  flowers,  which 
are  bilter,  are  likewise  employed  medicinallj  aa 


the  oiiide  condition  by  digesting  the  boiliDs 
aqoeons  extract  with  a  little  sulphuric  acid 
(Ferkin  and  Pilnim,  Chem.  Soc.  Tr&na.  1898, 
268).  A  btowniui-ydlow  powder  thus  septusteB, 
which  contains  three  substaaces  :  Uorhanntlin, 
qntrttlin,  and  taanpftroL 

IsorJkiiniiutin  Ci^i,0»  the  sparingly  aoluble 
oonalitneat,  forma  yellow  neeiUee,  resembling 
rhamnelin  in  appeai«nc«.  With  lead  acetato 
in  alooholio  solution,  an  orange-red  precipitate 
is  formed,  whilst  ferric  chloride  gives  a  greenish- 
black  oolonntion.  Fnsed  with  alkali,  jMoro- 
ghicinat  and  profocatccAute  acid  are  produced, 
and  when  lur  is  aspirated  throogh  its  alkaline 
eolation,  phiorogltieiKol  and  vanitiic  acid  are 
obtained. 

With  acetic  anhydride  I'jorbBmnetin  givee  a 
Utra-aefiyl  derivaUve  G„H,OXC,H,0),,  colour- 
less needles,  m.p.  igs''-19e° :  and  with  methyl 
iodide  a  Irimdhyl  ether,  which  is  identical  with 
giMreelin  IdramtAyl  eiher.  As,  moreover,  by 
the  action  of  hydriodio  acid  iwrh&mnetlD  yields 
quercetin,  its  constitutioD  can  only  be  repre- 
■suted  as  follows ; — 

The  dyeing  properties  of  imrluimnetin  are 
similar  in  character  to  those  given  by  kaempferol, 
uoRhamnetin  is  also  present  in  yellow  walluowers 
^Cietranlhut  cheiri)  {Perkin  and  Hummel],  and 
in  red  clover  flowers,  TriftJium,  pralaue  (Power 
and  Salway,  Chem.  Soc.  Trans.  1910,  97.  246). 
A  description  of  the  mare  soluble  cobnring 
matters  quercetin  {quercitron  baric)  and  koemp- 
terol  {Delphinium  eonadida)  is  given  elsewhere. 

In  dyeing  properties  asbarg  closely  resembles 
quercitron,  bark,  but  yields  with  aluminium 
mordant  a  purer  or  less  orange- yellow.  It  is, 
however,  a  much  weaker  dyestuS,  having  but 
36  p.0.  the  dyeing  power  of  quercitron  bark. 
The  colouring  matter  of  the  flowers,  opart  from 
the  Sowering  stalks,  is  present  to  the  extent  of 
3  4Tp.o. 

The  stems  and  flowers  of  the  D.  eanicida- 
folium  givee  shades  analogous  to,  though  some- 
what weaker  than,  those  yielded  by  the  D.  ialil. 
A.  G.  P. 


ASBESTOS,  from  tr^HTM,  'nnqoenokad.' 
Both  in  ancient  and  modem  times  varknu 
sitioate  minerals,  clawly  maembting  one  another 
in  their  finely  fibrous  texture  and  flexibility, 
have  been  and  an  still  confused  nnder  this 

'  amianthus  '  or  '  aminatoa  '  {ifdmrrrt,  '  nn- 
defiled,'  because  not  injured  by  Gie>.  Vmj  are, 
theiefote,  c(dlective  namM  of  no  mon  deflnite 
■igni&oation  Uian  the  adjeotivo  '  asbeatiform.' 
Hineralogista  are,  however,  agreed  in  limiting 
the  name  asbestos  to  the  fibrous  forms  of  horn- 
blende,  but  this  limitation  t*  not  generally 
obaerved.  Any  ambiguity  may  be  avoided  by 
using  the  terms  amphibole-asbestos  (or  horn- 
blende-asbestos),  serpentine -asbestos,  &o.,  for 
these  osbeetifonn  minerals.  The  finely  fibrona 
texture  is,  of  coarse,  an  accidental  chuaater  of 
the  mineral  species,  depending  on  the  enormons 
elongation  in  one  direction  of  the  individoal 
eryitala  which  form  the  aggref^te.  Suoh  a 
character  might,  indeed,  be  assumed  by  many 
kinds  of  minerals ;  but  it  is  only  the  following 
that  ore  of  any  importance  in  this  oonneotjon  ^-  - 


SH,0. 
The  first  two  pf  these  dlfler  only  In  the 
relative  proportions  of  the  mntually  replaoeabb 
magnesium  and  ferrous  iron  [and  oonseaaently 
olio  in  their  colours,  which  are  white  and  grttu 
reopectively),  and  they  are  mer«ly  varietiea  of 
the  species  amphibole  or  hornblende.  Crooi- 
dolite  is  another  species  of  the  amphibole 
group  of  minerals,  crystoUiaing  in  the  mono- 
clinic  syetem,  and  also  with  an  angle  of  66* 
between  ita  prismatic  cleavages.  It  is  known 
in  the  trade  as  '  blue  asbestos,'  and  It  gives 
the  name  to  the  Asbestos  Mountains  in  South 
Africa,  whore  it  is  found.  Whilst  hornblende 
is  more  frequently  found  as  stent  crystals 
and  compact  masaea,  crocidcdite,  on  tike  other 
hand,  is  as  yet  known  only  in  the  finely  fibrous 
form.  Anthophyllite  also  belongs  to  the 
amphibole  groap,  but  ti  orthorhombio  ia 
crystallisation.  Some  of  the  osbestes  mined  in 
the  United  States  (Georgia  and  Idaho)  is  of 
this  kind.  Serpentine  occurs  in  nature  as  large 
rock-mosses,  and  the  compact  rock  is  frequently 
traversed  by  veins  of  fibrous  material  of  thia 
same  composition ;  the  Utter  is  known  to 
mineralogists  as  chri/toliie,  and  in  the  trade  aa 
'  asbestos '  or  '  Canadian  asbestos.'  In  the 
minerals  of  the  palygoiskite  group  (A.  E.  Fera- 
man.  Bull.  Acad.  3ci.  St.  Foteraburg,  190S,  U, 
260,  637)  the  fibres  rarely  show  a  parallel 
'  t  are  more  usually  matt«d  and 
,    giving    felted    masses    known   aa 

leatber/      '  mountain-cork,'      and 

mountain. wood.'  It  is,  however,  to  be  remem- 
bered that  these  trivial  names  may  also  bo 
applied  to  similar  aggregat«s  of  fibrous  amphi- 

From  a  practical  point  o!  view,  the  most 
imporUot  ol  these  are  (remolile-MbatM  and 
eerpenline-a^iitoe,  which  in  the  ^^^  '■^*^^ 
as  ■  Italian  asbestos "  and  '  (^^fiviv^o  uVivMa 


896 


ASBESTOS. 


respectively.  The  former  is  met  with  as 
aggregates  or  bmidles  of  white  or  greyish  fibres, 
sometimes  several  feet  in  length,  usually  arranged 
parallel  to  the  surfaces  of  crevices  in  the  meta- 
morphic  and  crystalline  rocks  of  mountainous 
districts.  It  is  mined  in  the  Alps,  Urals,  and 
Appalachians.  The  supply  is  limited  and  un- 
certain, and  the  hardness  of  the  enclosing  rocks 
makes  mining  difficult.  The  principal  mines 
are  those  in  the  north  of  Italy,  m  the  Susa  and 
Aosta  valleys  in  Piedmont,  and  the  Valtellina 
in  Lombardy.  These  are,  however,  now  of 
little  importance,  since  the  use  of  hornblende- 
asbestos  nas  been  largely  replaced  by  serpentine- 
asbestos. 

Serpentine-asbestos,  or  chrysotUe,  occurs  in 
small  veins  forming  an  irregular  network  in 
serpentine-rock.  It  has  ,in  the  closely  com- 
pacted mass  an  oil-yellow  or  greenish  colour 
with  a  pronounced  silky  lustre  and  a  certain 
degree  of  translucency.  When  rubbed  or 
cruished,  it  readily  separates  into  white  cottony 
fibres  (pierre  &  coton  of  the  French-Canadians). 
The  fibres  are  arranffed  perpendicularly  to  the 
walls  of  the  vein,  and  are  usuallv  only  an  inch 
or  two  in  length,  never  exceeding  6  inches. 
The  mineral  usually  contains  2-3  p.c.  FeO 
isomorphously  replacing  magnesia.  Chrysolite 
is  found  at  all  the  locuities  where  serpentine- 
rock  occurs  {e,g,  the  Lizard  district  in  Cornwall), 
and  it  is  extensively  mined  in  Canada,  Russia, 
South  Africa,  and  tne  United  States.  Of  these 
the  most  important  are  th^  Canadian  deposits, 
whioh  have  been  worked  since  1878.  The 
mining  districts  are  near  the  villages  of  Thetf  ord, 
Black  Lake,  East  Broughton,  and  Danville  in 
Quebec;  and  extend  over  the  United  States 
border  into  Vermont.  The  mineral  is  also 
mined  in  Arizona  and  Califomia.  In  Russia, 
the  principal  deposits  are  in  the  Ural  Mountains, 
in  the  neighbourhood  of  Ekaterinburg  and 
Orenburg  ;  and  there  are  others  in  the  Caucasus. 
Recently,  rich  denosits  have  been  opened  up  in 
Rhodesia  in  the  Victoria  and  the  Gwelo  distncts, 
and  in  the  Caroline  district  in  the  Transvaal. 
The  asbestos  quarried  by  the  ajicients  at 
Karystos  in  Eubcea  (Elarystian  stone),  and  in 
Cyprus,  was  also  a  serpentine-asbestos  (J.  W. 
Evans,  Mineral.  Mag.  1906,  xiv,  143;  Geol. 
Mag.  1909,  vi,  286).  He  suggests  the  name 
iCary^wUie  as  an  alternative  for  chrysotile, 
owin^  to  its  confusion  with  chrysolite — a  synonym 
of  olivine).  It  was  used  for  wicks  in  the  per- 
petually burning  lamps  of  the  temples;  and 
was  woven  into  napkins,  which  could  be  cleansed 
by  fire,  and  into  cremation  shrouds. 

The  blue  asbestos  or  crocidolite  (^.t;.)  of 
South  Africa  has  during  the  last  twenty  years 
become  of  commercial  importance  and  has  been 
mined  in  increasingly  large  amounts.  It  occurs 
as  layers  interbedoed  in  the  brown  jasperj  and 
ironstones  of  the  lower  portion  of  the  Pretoria 
series  of  sedimentary  rocks,  and  is  quarried  or 
mined  as  slabs  in  wluch  the  fibres  of  the  mineral 
run  perpendicularly  or  somewhat  obliquely  to 
the  surfaces.  The  belt  of  crocidolite-bearing 
rocks  extends  for  a  distance  of  about  300  miles, 
with  a  width  of  4-20  miles,  from  the  Orange 
River  through  the  Asbestos  Mountains  in 
Griqualand  West  into  Bechuana  Land.  Beauti- 
ful silky,  loose  fibrous  material  is  known  from 
Cochabamba  in  Bolivia. 


These  various  kinds  of  asbestos  differ  some- 
what in  their  resistance  to  adds  and  heat. 
Chrysotile  is  decomposed  by  hydrochloric  and 
sulphuric  acids ;  at  a  red  heat  (but  not  below) 
it  loses  water,  and  the  fibres  can  be  fused  in  the 
bunsen-flame.  Tremolite-asbestos  is  not  at- 
tacked by  acids,  and  it  is  more  difficultly 
fusible.  On  the  other  hand,  the  fibres  of 
ohrysotQe  are  more  flexible  and  more  suitable 
for  textile  purposes.  Crocidolite  is  readily 
fusible  to  a  black  magnetic  glass,  but  it  has  the 
advantage  that  it  is  but  sUghtly  attacked  by 
acids,  chemical  solutions,  and  sea-water.  It 
possesses  a  greater,  tensile  strength  and  is  moro 
elastic  than  chrysotile ;  and  is  further  a  good 
insulator  for  heat  and  electricity.  Notwith- 
standing these  differences,  these  varieties  of 
asbestos  are  put  to  much  the  same  uses,  but 
serpentine-asbestos  is  employed  in  far  larger 
quantities. 

Spun  asbestos  is  largely  used  for  steam 
]^ackmgs,  fireproof  curtuns;  and  as  cloth, 
twine,  and  rope  it  finds  a  variety  of  applica- 
tions. As  an  insulating  matenal,  asbestos 
fibre  is  used  for  coating  steam  and  hot-water 
pipes  and  cold-storace  plants ;  and  as  a  lining 
m  safes,  stoves,  and  fumaceo.  For  use  as  a 
constructional  fireproof  material,  it  is  made 
into  bricks,  boards,  millboardSj  plasters,  and 
paints,  being  often  mixed  with  other  materials. 
The  so-callra  'asbestic,'  largely  used  for  wall 
plaster,  is  prepared  by  grmdung  the  poorer 
material  ana  waste,  which  consists  of  narrow 
veins  of  asbestos  still  enclosed  in  the  serpentine- 
rock.  In  the  laboratory,  asbestos  is  used  for 
filtering  (a  pure  white  tremolite-asbestos  being 
best  for  this  purpose),  for  stoppings  in  com- 
bustion tubes,  and  in  the  form  of  card  for 
supports.  Asbestos  paper  or  twine,  soaked  in 
sodium  silicate  and  afterwards  treated  with 
calcium  chloride  solution,  can  be  used  for 
repairing  glass  apparatus. 

Beferences, — ^F.  Cirkel,  Cluysotile-asbestos, 
its  Occurrence,  Exploitation,  Mdling,  and  Uses 
(Minea  Branch,  Ottawa,  end  edit.,  1910) ;  R.  H. 
Jones,  Asbestos  (London,  1890),  and  Asbestos 
and  Asbestic  (London,  1897) ;  G.  P.  Merrill, 
Asbestos  and  other  Asbestiform  Minoralfl  (Proc. 
U.  S.  Nat.  Museum,  1896,  xviii,  281),  and  Non- 
metallic '  Minerals  (New  York,  I9I0) ;  H.  Ries, 
Economic  Geology  (New  York,  1916) ;  Pro- 
duction and  Uses  of  Asbestos  (Bull.  Imp.  Inst, 
1905,  iii,  277) ;  The  Technical  Preparation  of 
Asbestos  {tbid.  1908,  vi,  393);  J.  S.  Diller. 
Mineral  Resources  of  the  United  States,  for 
1915,  1916,  ii,  13 ;  H.  F.  Olds,  Blue  Asbestos 
[Crocidolite  in  South  Africa]  (Trans.  Inst. 
Mining  and  MetaU.  1899,  vii,  122);  0.  B. 
Hopkms,  Mineral  Industry  (New  York,  1916, 
1917,  XXV,  62) ;  and  Bull.  Geol.  Survey,  Gieorgia, 
1914,  No.  29;  G.  E.  B.  Frood,  The  Capo 
Asbestos  Industry  [CrocidoUte]  (Ann.  Rep. 
Govt.  Mining  Engineer,  Bept.  of  Mines,  S. 
Africa,  1915;  ana  S.  African  Mining  Journ. 
1916) ;  P.  A.  Wagner,  Asbestos  in  South  Africa, 
(S.  African  Journ.  of  Industries,  1917,  i.  No.  3) ; 
A.  L.  Hall,  Asbestos  in  the  Union  of  South 
Africa  (Geol.  Survey,  1918,  Mem.  No.  12).  For 
an  account  of  the  Canadian  asbestos  industry, 
see  J.  Roy.  Soc.  Arts,  1913,  62,  36). 

L.  J.  S 

ASDUANA  V,  Bbidelia  babk. 


ASH. 


397 


ASEPTDI.  Trade  name  for  a  mixture  of 
hydrogen  peroxide,  boric  acid,  and  salicylic  acid; 
used  as  an  antiseptic. 

ASEPTOL.  Trade  name  originally  siven  to 
a  solution  of  o-phcnokulphonio  acid  C«H4(0H) 
SO,H.  It  is  a  thick  reddish  fluid,  of  1  '45  sp.ffr., 
having  a  faint  odour  like  phenol.  OccasioniJly 
called  sozdic  acid.  It  is  an  antiseptic,  but  does 
not  possess  the  poisonous  action  peculiar  to 
phenol,  and  is  therefore  recommended  for 
anigical  and  ophthalmic  operations  (Chem. 
Zentr.  1884,  720). 

The  aseptol  of  Merck  is  p-phenol  sulphonio 
acid  mixed  with  about  6  p.o.  of  the  o-acid 
(Obermiller,  Chem.  Zentr.  1907,  1615). 

The  name  is  also  given  to  a  preparation  con- 
taining from  0*25  to  10  parts  potassium  oxy- 
quinoline  sulphate,  0*5  to  10  parts  soap,  dissolved 
in  1000  parts  of  water,  mixed  with  terpineol  or 
other  aromatic  substances,  and  occasionally 
glycerol  (Pharm.  Zeit.  1897,  770). 

Aseptol  is  also  the  name  given  to  an  iU-defined 
mixture  of  phenyl  ethers  and  sulphonated 
phenols,  obtained  by  the  action  of  sulphuric 
acid  on  phenol  in  presence  of  alcohol  (Trillat, 
J.  Soc.  Chem.  Ind.  1892,  1028). 

ASFRAX  or  Trayamana,  An  Indian  drug, 
oonsisting  of  the  flowers,  flower-stalks,  and  im- 
mature fruit  of  a  species  of  Delphinium.  Used 
in  Bombay  as  a  medicine,  and  as  a  yellow  dye 
for  silk  (Dymock*  Pharm.  J.  [3]  8, 161). 

ASH.  This  term  is  sometimes  used  to  denote 
the  inoiganie  or  mineral  matter  contained  in  any 
substanoe,  but  more  generally  refers  to  the 
residue  left  on  completely  burning  or  incinerating 
it.  The  two  meanings  are  not  necessarily  the 
same,  since  in  any  animal  or  vegetable  substance 
the  inoraanic  constituents  are  usually  present  in 
very  di&rent  states  of  combination  to  those  in 
which  they  occur  in  the  residue  left  when  the 
bubetance  is  completely  oxidised. 

To  ascertain  the  exact  amount  and  com- 
position of  the  inorganic  matter  present  in  any 
oreanio  substance  is  often  a  matter  of  con- 
siderable difficulty,  and,  in  many  cases,  is 
Impracticable. 

The  term  'ash'  should  be  used,  therefore, 
only  in  the  second  sense  given  above. 

Most  animal  and  vegetable  substances  leave, 
on  combustion,  a  residue  containinff  the  follow- 
ing constituents  in  varying  proportions : — 


tion  of  the  amount  and  composition  of  the  ash 
of  animal  and  vegetable  substances,  though, 
perhaps,  inadequate  to  ascertain  Uie  exact, 
nature  of  the  inorsanio  constituents  of  the 
organised  bodies,  anords  valuable  information 
as  to  their  fitness  as  foodstufb,  and  as  to  the 
neods  of  animals  or  plants. 

In  the  process  of  incineration,  there  is  great 
danger  of  loss  of  chlorides  of  potassium  and 
sodium  by  volatilisation,  also  of  reduction  of 
phosphatra  and  sulphates  bv  the  reducing  action 
of  the  hot  carbon.  Berthelot  proposed  to  over- 
come these  difficulties  by  heating  in  a  current 
of  oxygen,  the  substance  to  be  incinerated  being 
previously  mixed  with  a  known  weight  of 
sodium  carbonate  (Compt.  rend.  128,  23 ;  c/. 
Roberts,  Analyst,  1918,  254). 

Shuttleworth  (Chem.  Zentr.  1899,  ii.  lUJI^has 
suggested  the  addition  of  calcium  acetate  in 
order  to  prevent  the  sinterinff  which  is  so  often 
an  obstacle  to  complete  incmeration,  and  has 
devised  a  special  platinum  vessel  in  order  to 
prevent  loss  of  chlorides  by  volatilisation,  and  to 
hasten  incineration.  A  modified  form  of  this 
apparatus  is  described  by  Tucker  (Ber.  32, 2583). 

A  convenient  method  of  minimising  the  loss 
of  chlorides  by  volatilisation  is  to  char  the 
substance  thoroughly  at  a  moderate  temperature, 
then  cool  and  extract  the  black  residue  with 
water,  filter  off  the  soluble  matter,  and  complete 
the  incineration  of  the  residue  after  drying. 
When  all  black  particles  have  disappeared,  the 
residue  is  allowed  to  cool,  the  aqueous  extract 
added,  evaporated  to  dryness,  and  then 
moderately  heated.  Addition  of  ammonium 
nitrate  to  the  black  char  hastens  the  combustion 
of  the  oarbon. 

Ash  of  animals.  The  proportion  of  ash  con- 
stituents present  in  the  whole  body  of  an  animal 
depends  largely  upon  its  condition,  being  greater 
in  lean  than  in  fat  animals.  According  to  the 
Rothamsted  experiments,  the  following  table 
gives  the  average  proportions  of  ash  and  of  its 
main  constituents  m  the  whole  bodies  of  various 
farm  animals  in  a  fatted  condition  :«- 


Aoldio 
Chlorine 
Carbon  dioxide 
Sulphur  trioxide 
Sulphur 

Phosphorus  pentoxide 
Silica 


Bssio 
Sodium 
Potassium 
Calcium 
li^gnesinm 
Iron 
Manganese 


Other  constituents,  generally  in  small  quantities, 
are  lUso  often  present. 

In  the  original  substance  the  greater  portions 
of  the  basic  constituents  in  the  above  list  are 
probably  present  in  combination  with  organic 
acids,  and,  consequentlv,  are  left  in  the  ash  ae 
carbonates  (often  largely  the  case  with  potash 
snd  soda)  or  as  oxides  {e.g,  portions  of  the  lime, 
magnesia,  oxides  of  iron,  ana  manganese) ;  while 
the  carbonates,  sulphates,  and  phosphates  are, 
in  many  cases,  derived  from  organic  combina- 
tions of  carbon,  sulphur,  and  phosphorus  exist- 
ing in  the  original  substance.    Tbo  determina- 


Fat  calf 
Half -fat  ox 
Fat  ox  . 
Fat  lamb 
Store  sheep 
Fat  sheep 
Store  pig 
Fat  pig 


ToUl 
ash 

3*9 

Phos- 
phoric 
acid 
PiO, 

lime 
CaO 

Mas- 
nesla 
MgO 

1*64 

1-65 

008 

6-1 

1-84 

211 

0-09 

4-2 

1-55 

1-79 

0-06 

3*2 

113 

1*28 

0-05 

3-3 

119 

1-32 

0-06 

3-0 

104 

118 

0-05 

2-8 

107 

1H)8 

0-06 

1-7 

0-65 

0-64 

0-03 

Potash 
KtO 


0-21 
0-21 
0-18 
017 
017 
0-15 
0-20 
014 


The  other  constituents  of  the  ash  consist 
chiefly  of  sodium,  chlorine,  fluorine,  iron,  man- 
ganese, iodine,  and  silica. 

The  bones  and  teeth  contain  the  greater  part 
of  the  phosphoric  acid,  lime,  magnesia,  and 
fluorine;  potash  is  present  Isigely  in  muscle, 
blood,  and  many  of  the  secretions;  sodium, 
chlorine  and  iron  are  largely  present  in  the 
blood  and  the  secretions,  while  iodine  is  mamly 
accumulated  in  the  thyroid  gland. 

(For  the  amount  and  composition  of  the  a*^' 


308 


ASH. 


The  following  table,  oompiled  chiefly  from  Wolff*8  analyses,  gives  the  average  proportions 
of  ash  and  of  its  chief  cpmponents  in  various  fresh  or  air-dried  agricultural  products. 
100  parts  of  the  substance  contain  :-^ 


Substaaoe 


Water     Aih 


E2O 


NaaO 


ICgO 


CaO 


P2O, 


SOs 


SiOs 


CI 


8 


Meadow  graaa 
Ryegrass 
Timothy  grass 
Oats,  in  mossom 
Barley,         „ 
Wheat, 
Rye  fodder    • 
Red  clover     • 
White  clover . 
Lucerne-        • 
Sainfoin         • 
Green  vetches 
Potato  tops   . 
Blangold  tops 
Sugar-beet  tops 
Turnip  tops   . 
Chicory  tops  . 
Carrot  tops    . 
Cabbage  heads 
Kohl-rabi  tops 


Meadow  hay  • 
Red  clover  hav 
White  clover  hay 
Lucerne  hay  . 
Sainfoin  hay  • 
Oat  hay 
Wheat  straw  • 
Rye  straw 
Barley  straw . 
Oat  straw 
Maizo  straw  . 
Pea  straw 
Field  bean  straw 
Buckwheat  straw 
FLaz  straw 
Flax,  whole  plant 
Hop,       „        „ 
Hops     . 
Tobacco 
Heather 
Broom 
Fern 
Reeds 
Sedge 
Rush 


Pototo  . 
Artichoke 
MajQgold 
Sugar  beet 
Turnip  . 
White  turnip 
Kohl-rabi 
Carrot  . 
Chicory 


L  Orun  Fodder. 


700 

2-33 

0-60 

016 

Oil 

0-27 

70-0 

213 

0*53 

0-09 

0-05 

016 

70-0 

210 

0-61 

006 

0-08 

0-20 

770 

1-66 

0-66 

0-06 

005 

Oil 

68-0 

2-25 

0-69 

0-01 

0-07 

014 

69-0 

217 

0-66 

0-01 

005 

007 

70-0 

1-63 

0-63 

0-01 

0-05 

012 

80O 

1-34 

0-46 

0-02 

016 

0-46 

81-0 

1-36 

0-24 

Oil 

014 

0-44 

76-3 

1-76 

0*46 

0-02 

010 

0-85 

78-6 

116 

0-46 

0-02 

0-07 

0-37 

82-0 

1-67 

0-66 

0-06 

Oil 

0-41 

77-0 

M8 

0-07 

001 

0-27 

0-55 

90-7 

1-48 

0-43 

0-31 

014 

017 

89-7 

1-80 

0-40 

0-30 

0-33 

0-36 

89-8 

1-40 

0-32 

0-11 

006 

0-45 

86-0 

1-87 

112 

0-01 

000 

0-27 

80-8 

2-61 

0-37 

0-60 

0-12 

0t86 

88-6 

1-24 

060 

0-06 

0-04 

019 

850 

2-63 

0-36 

010 

010 

0-84 

IL  Hay  and  StravK 


14-4 
16-0 
16-0 
16-0 
16-0 
14-6 
141 
15*4 
140 
141 
140 
14-3 
180 
160 
140 
250 
250* 
120 
180 
200 
160 
160 
180 
140 
140 


6-66 
5-65 
603 
6O0 
4-53 
618 
4-26 
407 
4-39 
4-40 
4-72 
4*92 
5-84 
617 
319 
3-23 
7-40 
6-98 
19-76 
3-61 
4-89 
5*89 
3-85 
696 
4-66 


1-71 

1-96 

1-06 

1-62 

1-79 

2*41 

0-49 

0-76 

093 

0-97 

1-66 

107 

2*69 

2-41 

1-18 

113 

1-94 

2-23 

6*41 

0-48 

0-69 

2-62 

0-33 

2-31 

1-67 


0-47 

009 

0-47 

007 

0O8 

0-20 

012 

013 

0-20 

0-23 

0O6 

0-26 

0-22 

Oil 

016 

016 

0-28 

013 

0-73 

0-19 

0O5 

0-27 

001 

0-51 

0-30 


0-33 
0-69 
0-60 
0*35 
0-26 
0-20 
0-11 
013 
Oil 
018 
0*26 
0-38 
0*46 
0-19 
0-23 
0-29 
0-43 
0-21 
207 
0-30 
0-28 
0-45 
0O5 
0-29 
0-29 


0-77 
192 
104 
2-88 
1-46 
0-41 
0*26 
0-31 
0-33 
0-36 
0-60 
1-86 
1-35 
0-96 
0-83 
0-60 
1-18 
101 
7-31 
0-68 
0-32 
0-83 
0-23 
0-37 
0-43 


ni.  Bool  Crops. 


015 
017 
0-23 
0-14 
0-22 
016 
0-24 
0-13 
0-20 
0-15 
012 
0-20 
0-06 
008 
0-13 
013 
0-17 
012 
0-20 
0-26 


0-41 
0-66 
0-85 
0-61 
0-47 
0-61 
0-23 
019 

0-19 
0-18 
0-38 
0-38 
0-41 
0-61 
0-43 
0-74 
0-90 
0-90 
0-71 
018 
016 
0-67 
0O8 
0-47 
0-29 


012 
0-08 
0O8 
0O5 
007 
0-04 
002 
0-04 
012 
Oil 
0O4 
0-06 
0-06 
Oil 
0-14 
014 
017 
0-21 
Oil 
0-30 


0-69 
0-84 
0-75 
0;66 
1% 
1-23 
0-52 
0-04 
0-06 
0O4 
0-05 
0O3 
005 
007 
0-06 
0O6 
002 
0-15 
OOl 
0-26 


019 

0-06 

Oil 

007 

0-11 

0O8 

007 

0-04 

0O8 

007 

0-06 

005 

0O5 

0-06 

0O4 

0-06 

0O3 

0-08 

003 

_ 

0-05 

0-03 

0-04 

0-06 

017 

0-05 

010 

^— 

0-12 

0O5 

0O3 

^— 

0-19 

0-14 

003 

0O5 

0-10 

"— 

0*34 

197 

0-53 

0-17 

017 

0-15 

0-21 

0-21 

0-53 

0-27 

019 

0-27 

0-37 

012 

on 

0-26 

0-15 

018 

014 

^.^ 

017 

205 

0-25 

015 

012 

2-82 

^— 

016 

008 

2-37 

— ■ 

0-09 

0-16 

2-36 

— 

0-13 

0-15 

2-11 

— 

0-17 

0-26 

1-79 

_ 

0-39 

0-28 

0-28 

0-30 

007 

001 

0-31 

0-81 

0-22 

0-27 

0-28 

0-40 

— 

0-20 

0-22 

0-15 

0-14 

0-16 

0O8 

0-19 

^— 

0-38 

1-59 

0-34 

0-20 

0-16 

0-92 

002 

0-48 

0-77 

1-92 

0-88 

— 

016 

1-27 

0-08 

__ 

007 

0-19 

0O5 

_ 

0-30 

0-36 

0-60 

._- 

Oil 

2-75 

—— 

... 

0-23 

2-18 

0-39 

—. 

0-40 

060 

0-65 

... 

760 

0-94 

0-56 

001 

0-04 

002 

0-18 

0-06 

0-02 

0O3 

0-02 

80O 

103 

0-67 

— 

003 

0O4 

016 

0O3 

002 

... 

88-3 

0-80 

0-43 

0-12 

0-04 

0-04 

0O8 

003 

002 

006 

002 

810 

0-80 

0-40 

0O8 

007 

0O6 

Oil 

0-04 

0O3 

002 

._ 

90O 

0-76 

0-30 

OOS 

003 

0O8 

0-10 

Oil 

002 

0O3 

0-04 

91-6 

001 

0-31 

002 

002 

0O8 

0-11 

0O4 

001 

0-04 

— 

87-7 

0-95 

0-49 

0-06 

002 

0-09 

0-14 

0O8 

001 

0O5 

— 

860 

0-88 

0-32 

019 

0-06 

0-09 

0-11 

0O6 

002 

0-03 

001 

80O 

1-04 

0-42 

0O8 

007 

0-09 

015 

0-10 

0O6 

004 

— 

ASH. 


399 


Sabstance 

Water 

Ash 

E,0 

Na,0 

MgO 

CaO 

P.O. 

SO, 

310, 

CI 

8 

IV.  Oraina  and  Seeds. 

Wheat  . 

14-3 

1-77 

0-55 

0O6 

022 

0O6 

0-82 

0O4 

0O3 

_M 

015 

Rye 

14-9 

1-73 

0-54 

0O3 

019 

0O5 

0-82 

0O4 

0O3 

— 

017 

Barley  . 

14-5 

218 

0-48 

0O6 

018 

0O5 

0-72 

0O5 

0-59 

— 

014 

Oats      . 

14-0 

2-64 

0-42 

010 

018 

010 

0-56 

0O4 

1-23 

— 

0-17 

Spelt     . 
Maize    • 

14-8 

3-58 

0-62 

006- 

0-21 

0O9 

0-72 

0O6 

1-58 

— 

—^ 

13-6 

1-23 

0-33 

0O2 

018 

0O3 

0-55 

OOl 

0O3 

— 

012 

Sorghum 
Mil&t    . 

14-0 

1-60 

0*42 

0O5 

0-24 

0O2 

0-81 

-— 

012 

— 

— 

13-0 

3-90 

0-47 

0O4 

0-33 

0O4 

OOl 

OOl 

205 

... 

0-18 

Paddy  rice     • 

12-0 

6-90 

1-27 

0-31 

0-69 

0-35 

3-26 

0O4 

004 

— 

— 

Rice      . 

13-0 

0*34 

008 

0O2 

0O5 

OOl 

017 

— 

OOl 

— 

— 

Buckwheat    . 

141 

0-92 

0-21 

0O6 

012 

0O3 

0-44 

0O2 

— 

0O2 

— . 

Flaxseed 

11-8 

3-22 

104 

0O6 

0*42 

0-27 

1-30 

0O4 

0O4 

— 

0-17 

Peas      . 

13-8 

2-42 

098 

0O9 

019 

012 

0-88 

0O8 

0O2 

0O6 

0-24 

• 

Field  beans   • 

• 

141 

2-96     1-20  1  0O4  1 

0-20 

015 

116 

015 

0-04 

008 

0*23 

V.  FruUa,  dfc 

Apple,  whole  fruit 

84-0 

0-27 

010 

0O7 

0O2 

OOl 

0O4 

0O2 

OOl 

^^^ 

_ 

Pear,        „        „    . 

80-0 

0*41 

0-22 

0O4 

0O2 

0O3 

0O6 

0O2 

OOl 

— 

— 

Cherry,    „        „     . 

78-0 

0-43 

0-22 

OOl 

0O2 

0O3 

0O7 

0O2 

0-04 

OOl 

— 

Plum,       „        „    . 

82-0 

0-40 

0-24 

— 

0O2 

0O4 

0O6 

0O2 

OOl 

~~^ 

^— 

AcomB,  fresh 

56-0 

0-96 

0-62 

OOl 

0O5 

0O7 

016 

0O5 

002 

OOl 

— 

Beech  mast    . 

180 

2-71 

0-62 

0-27 

0-31 

0-67 

0-56 

0O6 

0O5 

OOl 

_ 

Horse  chestnuts 

49*2 

1-20 

0-71 

— 

OOl 

014 

0-27 

0O2 

^~~ 

0O8 

— 

VI.  Leavu — Auhimn, 

Mulberry 

67-0 

117 

0-23 

_ 

0O6 

0-30 

012 

OOl 

0-41 

_ 

_ 

Horse  chestnut 

60-0 

301 

0-69 

— 

0-24 

1-22 

0-25 

0O5 

0-42 

012 

— 

Walnut 

60-0 

2-84 

0-76 

— 

0-28 

1-53 

Oil 

0O8 

0O6 

0-02 

Beech   . 

•         • 

65-0 

306 

016 

0O2 

018 

1-37 

013 

Oil 

103 

OOl 

— . 

Oak      . 

1         • 

60-0 

106 

0O7 

OOl 

008 

0O5 

016 

009 

0-61 

Scotch  fir 

►         • 

55-0 

0-63 

0O6 

— 

0O6 

0-26 

013 

0O3 

0O8 

0O3 

— 

Spruce  . 

1         • 

65-0 

2*63 

0O4      — 

0O6 

0-40 

0*21 

0O7 

1-84 

— 

— 

Vn.  Manufaettured  Products. 

Fine  wheat  flour     . 

136 

0*41 

015 

OOl 

003 

OOl 

0-21 

—       1     ~~       1     ""'       i     ~~ 

Wheat  bran  • 

13-6 

5-56 

1-33 

0O3 

0*94 

0-26 

2-88 

r 

0-06 

— 

Rye  flour 

14-2 

109 

0-65 

0O3 

014 

0O2 

0-85 

— 

— 

— 

— 

Rye  bran 

131 

714 

103 

0O9 

1-13 

0-25 

3-42 

— — 

_ 

— 

Barley  flour 

14-0 

2-00 

0-58 

0O5 

0-27 

0O6 

0-95 

0O6 

— 

— 

^•^^ 

Maize  meal 

140 

095 

0-27 

0O3 

014 

0O6 

0-43 

— 

— 

— 

— 

Malt      . 

4-2 

206 

0-46 

— 

0-22 

0-10 

107 

— . 

0-88 

— 

_— 

Malt  dust 

9-2 

596 

208 

_ 

0O8 

0O9 

1-25 

0-38 

1-77 

.— 

— 

Beer     . 

90-0 

0*39 

015 

0O3 

0O2 

OOl 

013 

OOl 

0O4 

OOl 

— 

Wine    • 

86-6 

0-28 

018 

— 

0O2 

0O2 

005 

OOl 

OOl 

— — 

Linseed  cake 

11-6 

5-52 

1-29 

0O8 

0-88 

0-47 

1-94 

019 

0*36 

0-03 

— 

Cotton-seed  cake    . 

11-5 

615 

218 

_ 

0-26 

0-28 

2-95 

0O7 

0-25 

— 

— 

Potato  skins  . 

30-0 

6-71 

4-83 

0O5 

0-45 

0-64 

0-23 

0O3 

018 

014 

— 

Buckwheat  groats  • 

140 

0-62  1  016 

0O4 

0O8  1  OOl 

0-30  i  OOl 

— 

OOl  1    — 

Vin.  Wood  (aif^ritd). 

Apple  tree     •         • 

15-0 

1-10 

0-13 

0O2 

0O6 

0-78 

0O5 

0O3 

0O2 

.i. 

_ 

Beech,  trunk           • 

16-0 

0-55 

0O9 

0O2 

006 

0-31 

0O3 

OOl 

0O3 

^— 

_. 

Beech,  brushwood  . 

15-0 

1-23 

0-17 

0O3 

013 

0-59 

015 

OOl 

012 

— 

^-m 

Birch    •         •         • 

16-0 

0-26 

0O3 

0O2 

0O2 

015 

0O2 

— . 

OOl 

—' 

— 

Grape   . 
Muloerry 

•         • 

16-0 

2-34 

0-70 

016 

016 

0-87 

0-30 

0O6 

0O2 

0O2 

-— 

• 

16-0 

1-37 

0O9 

0-20 

0O8 

0-78 

0O3 

014 

0O5 

0O6 

— 

Larch    • 

•        • 

16-0 

0-27 

0O4 

0O2 

007 

0O7 

OOl 

OOl 

OOl 

— 



Oak       . 

•         • 

150 

0-51 

0O5 

0O2 

0O2 

0-37 

0O3 

OOl 

OOl 

_ 

—.- 

Scotch  fir 

•         • 

160 

0*26 

0O3 

OOl 

0O2 

013 

0O2 

OOl 

0O4 

^"~ 

"^ 

« 

of  yarious  portions  of  tbe  animal  body,  and  of 
certain  animal  products,  v.  Bonis  ;  Blood  ; 
Mnjc;  ko) 

A  characteristic  of  the  ash  of  animal  sub- 
stances in  general,  is  tbe  usual  preponderance 


of  lime  oTer  phosphorus  pentoxide.  and  the 
relatively  high  ratio  of  sodium  to  potassium. 

Ash  of  plants.  The  nature  of  the  ash  of  the 
leaves,  stems,  &c.,  of  plants  is  affected  to  a 
considerable  extent  by  the  composition  of  the 


400 


ASH. 


Boil  in  which  the  plants  grow,  but  the  amount 
and  composition  of  the  ash  of  the  seeds  are  much 
less  variable. 

In  nearly  all  seeds  the  largest  constituent-s  of 
the  ash  are  phosphorus  pentoxide  and  potash. 
In  certain  seeds  genially  used  in  their  husk, 
t.g.  oats,  miUct,  s^t,  and  barley,  silica  is  a  large 
constituent. 

But  in  the  leaves  and  stems  of  plants, 
phosphorus  pentoxide  usually  forms  out  a 
small  constituent  of  the  ash,  whilst  potash 
and  liine  become  relatively  more  abundant. 
In  cereals  and  grasses,  silica  often  forms  more 
than  half  ol  the  total  ash  of  the  straw  and 
chafL 

In  addition  to  the  constituents  given  in  the 
above  table,  small  quantities  of  oxides  of  iron 
and  manganese  are  almost  invariably  present 
in  vegetable  ashes. 

Titanium  (Wait,  J.  Amer.  Chem.  Soc.  1896, 
18,  402),  aluminium  fluorine,  and  boron 
(Crampton,  Amer.  Chem.  J.  11,  227  ;  Jay, 
Ck)mpt.  rend.  121,  893;  Baumert,  Ber.  21, 
3290),  are  also  frequently  present  in  small 
quantities  in  the  ash  of  certain  plants. 

Lithium,  rubidium,  zinc,  copper,  barium, 
and  arsenic  have  also  been  detected  in  the  ash 
of  certain  plants  grown  in  soils  containing  these 
constituents  (Passerini,  Chem.  Soc.  Abstr.  1893, 
ii.  225;  Homberger,  ibid.  1899,  A,  ii.  606; 
Macdougal,  ibid,  1900,  A,  ii.  235). 

Even  chromium,molybdenum,  and  vanadium 
have  been  detected  in  the  ash  of  fir,  oak,  vine, 
and  poplar  (Demarcay,  ibid.  1900,  235). 

Indeed,  the  composition  of  the  soil  has  a 
great  influence  upon  the  amount  and  composi- 
tion of  the  ash  of  the  crop  grown  upon  it,  though 
this  influence  is  much  more  marked  upon  the 
foliage,  stem,  &c.,  than  upon  the  seed. 

Certain  pWts,  originating  from  plants  of 
the  seashore,  e.g.  asparagus,  oeet,  and  carrot, 
generally  leave  an  ash  containing  unusually  high 
amounts  of  chlorine  and  sodium,  and  applica- 
tion of  common  salt  as  manure  to  such  crops 
is  usually  stated  to  be  beneficial,  although  on 
no  very  sufficient  evidence. 

Plants  like  salt- worts  (Sdlsdla)  and  samphire 
{Salicomia)  growing  on  the  coast,  contain 
relatively  enormous  quantities  of  soda — in  the 
former  6  times,  in  the  latter  14  times,  as  much 
soda  as  of  potash. 

The  ash  of  the  dub-moss  {Lffcopodium) 
contains  from  20  to  50  p.c.  of  alumina. 

Manganese  is  invariably  present  in  tea- 
leaves,  and,  according  to  the  writer's  observa- 
tions, is  present  in  the  soluble  matter  {i.e.  in 
the  infusion). 

As  abready  stated,  some  of  the  phosphates 
and  sulphates  found  in  the  ash  of  plants  result 
from  the  oxidation  of  phosphorus  and  sulphur 
organic  compounds  present  in  the  original  plant. 

Postemak  (Compt.  rend.  137,  1903)  detected 
the  existence  in  peas,  beans,  potatoes,  and  the 
seeds  of  the  red  nr,  pumpkin,  white  and  yellow 
lupines  of  anhydro-oxymethylene  diphosphoric 
actd — 


^^^CH,— OPO(OH), 
"\CH,— OPO(OH), 


or  inositol  phosphoric  acid  CeHe(P04H,)s. 
Patten  and  Hart  (Bull.  250  (1904),  N.  York. 
Agric.  Expt.  Station)  have  shown  that  about 


86  p.c.  of  the  total  phosphorus  in  bran,  81  p.c. 
in  malt  sprouts,  ana  50  p.c.  in  oats,  is  soluble 
in  0*2  p.c.  sol.  of  hydrocUorio  acid ;  and  that 
the  greater  portion  of  this  is  present  in  the  bran 
as  calcium,  magnesium,  and  potassium  salts  of 
nositol  phosphoric  acid  {v.  Bran). 

Importance  of  the  Ash  Constituents  of  Foods. 

The  influence  of  the  mineral  matter  in  the 
food  of  animals  upon  their  health  and  well- 
being  is  probably  much  greater  than  is  generally 
recognised.  Not  only  is  it  essential  that  all 
the  inoiganic  constituents  required  for  building 
up  the  tissues  and  producing  the  various  digestive 
and  other  secretions  be  supplied  in  sufficient 
quantities,  but  it  is  importuit,  at  least  with 
certain  ]^airs  of  constituents,  that  they  be 
supplied  in  appropriate  ratios  to  each  other. 

A  preponderance  of  phosphoric  acid  over 
lime  and  magnesia  in  the  diet  is  probably  the 
cause  or  a  predisposing  cause  of  certain  diseases 
of  the  bones  of  horses,  mules,  and  donkeys 
(Ingle,  Jour.  Comp.  Pathology  and  Therapeutics, 
1907  ;  Jour.  Asric.  Science,  1908,  iii.  22  ;  Jour. 
Roy.  Inst.  Public  Health,  1909);  while  the 
ratio  of  potash  to  soda  in  the  food  has  an 
important  bearing  upon  health,  and  especially 
upon  the  susceptibility  to  certain  mseases, 
e.g.  scurvy. 

The  cereals  contain  a  l&i^  excess  of  phos- 
phoric acid  over  lime,  and  the  use  of  an  exdiu  i  vely 
cereal  diet  may  lead  to  imperfect  bone  nutrition 
{le. ;  also  Illustrated  Poultry  Record,  1910). 

The  necessity  of  an  adequate  supply  of 
chlorides  in  the  diet  is  weU  recognised,  and  in 
many  countries  the  ordinary  food  supjdies  of 
domestic  animals  have  to  be  supplemented  by 
common  salt  to  ensure  healthy  existence. 

Whenever  the  rations  are  restricted  to  one 
or  two  items,  there  is  considerable  probability 
that  certain  mineral  constituents  will  be  lacking 
or  supplied  in  improper  proportions. 

It  is  too  often  the  practice,  in  discussing 
the  feeding  of  animals,  to  devote  much  con- 
sideration to  the  organic  portions  of  their  food, 
but  beyond  requiring  that  sufficient  mineral 
matter  or  *  bone-forming  *  material  be  present, 
to  pay  little  or  no  attention  to  its  composition. 

Thus  bran  is  widely  regarded  as  a  food 
particularly  rich  in  mineral  matter,  and  therefore 
valuable  for  bone  nutriticm;  but  the  ratio  of 
phosphorus  pentoxide  to  lime  in  this  food  is 
about  11  to  1,  and  the  practice  of  feeding 
animals  largely  upon  bran  is  known  to  produce 
a  disease  of  the  bones — *  bran  rachitis '  in 
horses. 

Kellner  (Scientific  Feeding  of  Animals, 
1909)  estimates  that  for  oxen,  60  grams  of 
phosphorus  pentoxide  and  100  grams  of 
lime  per  1000  kilos,  body  weight  per  day,  are 
required  in  the  food,  whilerfor  niU-grown  sheep, 
1  gram  of  the  former  and  11  grams  of  lime 
,  Bumce. 

In  England,  fortunately,  hay — either  meadow 
or  clover — ^forms  a  large  part  of  the  rations  of 
farm  animals,  and  this  contains  a  Urge  excess 
of  lime  over  phosphoric  acid,  and  thus  neutralises 
the  opposite  preponderance  in  the  grain  or  oake 
used  with  it. 

But  in  South  Africa  and  perhaps  some  other 
countries,  meadow  or  dover  hay  is  but  little 
used,  and  many  horses  are  fed  entirely  upon 


ASPARAGINE. 


401 


oat  htLj  or  oat  hay  and  maise.  In  either  oaae 
them  18  a  lai]ge  preponderanoe  pf  phosphoric 
acid  oyer  lime,  and  to  this  fact  the  prevuenoe 
of  certain  hone  diseaees  ia  ahnoet  certainly  due. 

Similar  conaderationB  apply  to  other  animala 
kept  in  confinement^  eepecially  to  poultry  when 
dggivedola  grass  ran,  and  to  pigs.        H.L 

ASDPHTL.    SeeABTFBiL. 

ASPABAGOIB.      Aminosueeifiamie        acid 
C,H,NH,(CO,H)(CONH,)     occurs     in     two 
optically  active  f orms^  difiering  in  direction  of 
rotatory  power  and  in  taste.    LcewHupamgine, 
discovered  hy.Vauquelin  and  Robiquet  (Ann. 
Chim.  anal.  1806,  67»  88)  in  the  young  shoots  of 
asparagus  {Asporoffua  oJpcinaUs,  Linn. ),  is  widely 
(tistribnted  in  the  vegetable  kingdom,  occurring 
in  most  plants  at  the  time  of  budding  and  during 
the  flowering  period,  and,  with  glutamine,  forms 
the   chief  non-proteid   compounds  present  in 
the  juice  of  ripening  oranges  (Scurti  and  de 
Plato,  Chem.  Zentr.  1908,  u.  16,  1370 ;  Stieger, 
Zeitsch.   physiol.   C9iem.    1913,   86,   245,   269; 
Smolenski,  Zeitsch.  Ver.  deut.  Zuckerind,  1911, 
435;    Tutin,   Chem.    Soc.    Trans.    1913,    103, 
1274 ;   Chapman,  ibid,  1914,  105,  1901 ;   Tutin 
and  Clewer,  ibid,  1914,  670).    It  is  also  found  in 
blood   (Abderhalden,   Zeitsch.   physiol.   CSiem. 
1918,     88,     478^83).    Miyaoha     (Bull.     CoU. 
Agric.  Imp.  Univ.  Tokyo,   1897,  2,  458)  has 
shown  that  in  the  case  of  Pcumia  aJbifiora  and 
Thea  ehinentia,  even  old  leaves,  showing  incipient 
decay,  can  produce  asparagine.    It  occurs  to  a 
larger   extent  in  leffuminous   planto   than  in 
any  other  natural  oraer,  and  is  most  abundant 
at  the  time  of  germination,  the  quantity  being 
greater   in   etiolated   than   in   normal   plants 
(Borodin,   Bied.   Zentr.    1879,   357 ;    see   also 
Ritman,  Izv.  Moekow.  Selsk.  Kh§iz.  Inst.   18, 
212-220 ;    from  Abs.  Amer.  Chem.  Soc.  1913, 
3144 ;  Nicohueva,  Bull.  Agr.  InteUigenoe,  1917, 
8,    204).    Sachsse    (Landsw.    Versuchs.    Stat. 
1874,  17,  88)  found  that  the  amount  of  aspara- 
gine in  germinating  peas  increased  from  0*o7  to 
6*94  p.c.  during  24  days*  growth ;   and  Schulze 
and  UmUuft  {Snd.  1875,  18,  1)  found  17*9  p.c. 
of  asparaffine  in  the  dried  shoots  of  Luptnus 
luieus  seeaUngs  germinated  in  the  dork  in  dis- 
tilled  water  {ef!  also   Mercadante,  Gazz.  ital. 
chim.  1876,  6, 187 ;   Schulze,  Landsw.  Versuchs. 
Stat.  1895,  46,  383 ;    Stoklasa,  Landw.  Jahrb. 
1896,  24,  827;    Bourquelot  and  Herissey,  J. 
Pharm.  1898,  (vL)  8,  385 ;   Br^,  Ann.  Agron. 
1900,  26,  5;    Schuhse  and  Barbieri,  Landsw. 
Versuchs.  SUt.  21,  63 ;    Kinoshita,  BuU.  Coll. 
Agric.  Imp.  Univ.  Tokyo,  1895, 2, 203) ;  Schulze 
and  Boashard,  Zeitsch.  physiol.  Chem.  1885,  9, 
420;     Bungener,    Bied.    Zentr.     1885,    861; 
Behrens,  Bot.  Zentr.   1894,   178).    Asparagine 
is  one  of  the  decomposition  products  oiproteid 
matter  (Schulze,  Bied.  Zentr.   1901,  30,   106; 
Chem.  Zentr.  1901,  i.  1108;    Ber.  Deut.  Bot. 
Gee.  1907,  26,  213),  and  its  accumulation  in  the 
plant  during  the  periods  of  termination  and 
budding,   piurticularly  when   die   development 
occurs  in  the  dark  is  attributed  by  Borodin 
(Bied.  Zentr.  1879, 357)  and  Schulze  and  Barbieri 
(J.  pr.  Chem.  1882,  [2]  25,  145),  to  the  absence 
of   carbohydrates   which   under   conditions   of 
normal  euuimilation  effect  the  reincorporation 
of  amides  into  proteid  molecules ;    and   this 
view  is  confirmed  by  Monteverde  (Ann.  Agron. 
17,   376),   who   found   that   branches   of   lilac 
Vou  L—T. 


plnn^^  in  distilled  water  or  4  p.o.  glyoerol 
solution    and    kept    in    the    dark,    contained 
abundance  of  asparagine  at  the  end  of  15  days, 
but  neither  starch  nor  mannitol.    When,  how- 
ever, branches  of  the  same  plant  were  kept  in 
solutions  of  glucose,  sucrose,  or  mannitol,  they 
formed  no  asparagine  in  a  month,  but  contained 
much   manmtol  and  starch.    Another  source 
of   asparagine   in   the   plant   is   its   synthetic 
formation    from    ammomum    salts,    urea,    or 
nitrates  supplied  by  the  soil.    This  synthetic 
production  is  only  possible  in  the  presence  of 
sugar,  and  under  conditions  that  exclude  the 
formation  of  proteids  (Suzuki,  Bull.  CoU.  Agria 
Imp.  Univ.  Tokyo,  1895,  2,  196).    The  function 
of  the  asparagine  in  the  plant  economy  is  the 
production    ca    proteid    matter;     henoe    the 
addition  of  leguminous  seeds  after  steaming 
to  the  mash  in  brewing  is  recommended  by 
Biraer  (J.  Soa  Chem.  Ind.  1882,  333),  as  the 
asparagine  they  yield  forms  excellent  nutriment 
for  the  jreast  cell;    and  Kinoshita  (BuU.  C6U. 
Agric.  Imp.  Univ.  Tohyo,  1895,  2,  196)  found 
that  young  shoots  of  soja  bean  that  showed  an 
increase  in  asparagine,  from  21  *6  to  28  '7  p.br  after 
four  weeks*  natural  growth,  became  poorer  in 
asparagine  (18*9-13 '7  p.c.)  if  pown  for  the 
same  period  in  methyl  alcohol  and  glyoerol 
solution,  but  contained  reserve  proteid  matter. 
According  to  Ciamician  and  Ravenna  (Atti  R. 
Accad.  dei  Lincei  [5]  20, 1,  614-624),  there  is  an 
increase  of  alkaloid  in  the  tobacco  plant  and 
date  when  suppUed  with  asparaaine.    Morgen, 
Beger,  and  Westhausser  (Landw.  Versachs.  Stat. 
1911,  75,  265-320),  experimenting  with  sheep, 
claim  that,  given  a  sufficiency  of  carbohydrate, 
a  deficiency  of  protein  may  be  made  good  with 
ammonium  acetate  and  asparagine. 

Asparagine  can  be  extracts  from  the  juice 
expressed  from  young  vetch  seedlings  that 
have  germinated  in  the  dark,  10  kilos,  of  vetch 
yielding  150  grains  of  pure  asparagine  (Piria, 
Annalen,  1848,  68,  343).  Sure  and  Tottuogham 
found  that  asparagine  is  made  use  of  in  the 
nitrogen  metaoolirai  of  etiolated  pea  plants 
(J.  Biol.  Chem.  1916,  26,  535). 

Asparagine  crystalUses  from  aqueous  solution 
in  large  rhombic  lievo-  hemihedral  prisms, 
aib'.ci: 0*4752  : 1 :  0*8294  (Freundler,  Compt. 
rend.  1897,  125,  657),  containing  IH.O,  whu)h 
it  loses  at  100°,  and  then  melts  at  234''-235'' 
(Michael,  Ber.  1895,  28,  1629) ;  it  has  a  sp.gr. 
1-5434  at  14-874''  (Piutti,  Gazz.  chim.  ital.  1904, 
34,  36) ;  the  molecular  heat  of  combustion  is 
448*4  Cals.,  and  the  heat  of  formation  205*1 
Cals.  (Berthelot  and  Andre,  Compt.  rend.  1890, 
120, 884 ;  see  also  Emery  and  Benedict,  Amer.  J. 
Physiol.  28,  301-307) ;  it  is  sparingly  soluble  in 
cold,  readily  so  in  hot  water — 1  ps^  dissolves 
in  82  parts  of  water  at  lO"",  in  47  parts  at  20"" 
(Becker,  Ber.  1881,  14,  1028),  in  58  parts  at 
13^  and  1*89  parts  at  100°  (Guareschi,  Gazz. 
chim.  ital.  1876,  6,  370;  cf.  Bresler,  Zeitsch. 
physikal.  Chem.  1904,  47,  611).  The  aqueous 
soration  is  weakly  acid,  has  an  insipid  and  dis- 
agreeable taste,  and  is  Uevo-rotatory  \a]j^—6^  4/ 

(Piutti,  Compt.  rend.  1886,  103,  134);  the  • 
rotatory  power  6f  the  solution  is  increased  by 
raising  lihe  temperature  and  by  the  addition  of 
alkalis,  invertea  by  mineral  acids  and  by  solu- 
tions of  certain  inorganic  salts  and  destroyed 
by  acetic  acid  (Champion  and  Pellet,  Compt. 

2  D 


402 


ASPARAQINE. 


rend.  1876,  82,  819;  Beoker,  Ber.  1881,  14, 
1028 ;  Smolenaki,  Zeiteoh.  Ver.  deut.  Zuokerind, 
1910,  216;  and  1912,  791;  Pellet,  Z^iteoh. 
Ver.  deut.  Zuokerind,  1911,  435-443 ;  aoueh, 
Chem.  Soc.  Trans.  1915,  107,  1513;  Andriik 
and  Stanek,  Zeitach.  Zuokerind.  Bohm.  31, 
417).  Advantage  is  taken  of  this  last  faot 
to  eliminate  the  error  due  to  the  pieeenoe  of 
aspara^ne  in  saooharimetdo  determinations  of 
sugar  hquors  from  beets  and  oanes.  Asparagine 
is  partially  hydrolysed  by  boiling  with  water, 
forming  aspariic  add  *  (amtnoauccinic  acid) 
0,H3'NH,(C0gH),  and  ammonia;  the  change 
is  rapid  and  complete  when  excess  of  barium 
hydroxide  or  dilute  hydrochloric  or  sulphuric 
acid  is  employed  (Sohulze,  Landsw.  Veisuchs. 
Stat.  29,  233);  1^  the  action  of  potassium 
permanganate,  asparagine  Is  oxidised  to  oar- 
Damide  and  ammonia ;  and  when  used  in  6  p.o. 
aqueous  solution  for  the  culture  of  Bactuus 
pyrocyanietts,  it  Ib  oonyerted  into  aspartio 
acid  after  60  hours,  and  completely  decomposed 
after  72  hours  (Amaud  and  Gharrin,  Compt. 
rend.  1891,  112,  755;  Adeney,  Proc.  Roy. 
Irish  Acad.  1905,  25,  6).  An  aqueous  solution 
in  presence  of  sunlight  yields  acetaldehyde, 
ammonia,  and  carbon  dioxide  (Qanassini,  Giom. 
Farm.  Ghim.  1912,  62,  439-444).  Under  the 
action  of  enzymes,  asparagine  yields  a  mixture 
of  formic,  propionic,  and  sucdmc  acids  (Neuberg 
and  Cappezzuoli,  Bioohem.  Zeitsch.  1909,  18, 
424),  and  a  similar  change  la  effected  by  brewer's 
yeast  (Effront,  Mon.  Soi.  1909,  (iy.)  23,  i. 
145;  and  Kurono,  J.  Agrio.  Tokyo,  1911,  1, 
296-330). 

The  presence  of  asparagine  (1  :  19,000)  may 
be  detected  by  means  of  triketohydnndene 
hydrate  (Abderhalden  and  8ohmidt^  Zeitach. 
physiol.  Chem.  85,  143-147). 

The  estimation  of  aspan^e  is  based  npon 
its  quantitatiye  conyenaon  mto  aspartio  acid 
and  ammonia  by  the  action  of  hydrochloric 
acid,  the  aspartio  acid  may  be  remoyed  in 
the  form  of  its  sparingly  soluble  copper  salt 
(Engel,  Ck>mpt.  vend.  iSbS,  106,  1734)  and  the 
ammonia  determined  by  Saohsse'a  method  (J. 
pr.  Chem.  1872,  [2]  6,  118)  or  by  one  of  the 
modifications  of  Schloessing  s  method  described 
by  Meunier  (Ann.  Asron.  6,  275),  by  Sohulze 
(J.  pr.  Chem.  1885,  [2]  31,  233),  or  by  Brown 
and  Millar  (J.  Soc.  Chem.  Ind.  1904,  135). 
Palet  (Anal.  Soc.  Quim.  Argentina^  1917,  5, 
96)  points  out  that  the  results  of  the  estimation 
by  Schloessing^s  method  are  influenced  by  the 
employment  of  different  alkalis. 

Ai^^'^^®  has  feeble  basic  and  acidic 
properties,  and  forms  salts  with  acids  and  bases 
(Chautard  and  Dessaigne,  Annalen,  1848,  68, 
349;  Dessaigne,  Annalen,  1862,  82,  237; 
Smolka,  Monatsh.  1887,  6,  916) ;  it  also  forms 
double  compounds  witii  certain  salts  of  the 
heayy  metals,  the  sparing  solubility  of  the 
compound  with  mercuric  nitrate  is  made  use 
of  in  isolating  small  quantities  of  asparagine 
from  solutions  containing  carbohydrates 
(Sohulze,  Ber.  1882,  15,  2855) ;  it  forms  stable 
complex  internal  salts  with  certain  heayy  metals ; 
the  chromium  salt  CT{GJS.iOJSm)t  crystallises  in 
microscopic  rose-yiolet  needles  (Tschugaeff, 
Serbin,  Compt.  rend.  1910,  161,  1361-1363)  and 
combines  witn  copper  hydroxide  to  yield  a  copper 
complex  of  the  lormula  Cu(C4H703N|)g  (Kooer 


and  Sugiura,  J.  Biol.  Chem.  1912-1913, 13, 1-13); 
the  alum  (C.HgO,N,),H^O«,Al.(S04)„24H,0 
forms  octaheoral  crystals.  Asparagine  is  oon- 
yerted into  Z-ohlorosuocinio  acid  and  fumario 
acid  by  the  action  of  nitrosyl  chloride  in  hydro- 
chloric acid  solution  (Tilden  and  Forster,  Chem. 
Soc.  Trans.  1895,  67,  489) ;  it  yields  the  amide 
of  uramidosucoioio  anhydride 

CONHjCHjCHNHCONH 

do I 

when  fused  with  carbamide  (Guareaohi,  Gazz. 
chim.  ital.  1876,  6,  370),  and  ib  oonyerted  into 
amidosuccinurio  acid 

CONH,CH,-CH<^^^^'^^» 

m.p.  137^-138^,  by  the  action  of  potassium 
cyanate  (Guareschi,  Ber.  1877,  10,  1747). 
Certain  condensation  products  of  asparagine 
with  other  amino-  acids  are  described  by  Fischer 
(Ber.  1904,  37,  4685 ;  1907,  40,  2048),  ehioro- 
aceiyUuparagine,  m.p.  148^-149°  (corr.) ;  glycyl- 
asparagine,    m.p.    216**,    [a]jj— 6-4**    at    20**; 

ajihydroglycyJasparagine,  deoompoeing  at  274**; 
d-leucyl-l-asparagine,  deoompoeing  at  230**  (corr.), 
[a]^-63'6''  at  20'' ;    hleucyUd-asparagine,  m.p. 

228''    (corr.),    [4^+17*8'';     a&paragjfia$pafiie 

acid,  decomposing  at  120^  Sasaki  (Beitr. 
Chem.  Physiol.  Path.  1907,  10,  120)  describee  a 
benzoylpolypeplide  of  asparagine  CitHsiOgNc 
deoompoaing  at  210°,  and  giying  the  biuret 
reaction. 

Benzyl  hydrogen  asparaginedithiocarhoxiflate 

CO,HC,H,(CONH,)-NH-CS,'CH,Ph 

has  m.p.  180''.  The  barium  salt  crystallisea 
in  slender  needles  (Siegfried  and  Weidenhaupt, 
Zeitsch.  physiol.  Chem.  1910,  70,  152-160). 

As  regards  the  alimentary  yalue  of  asparagine, 
it  has  been  found  that  in  the  case  of  herbiyoroua 
mamnuds  and  geese,  asparagine  has  a  proteid- 
sparing  action,  and  under  appropriate  con- 
ditions preyents  waste  and  causes  the  formation 
of  proteid  matter  (Weiske,  Bied.  Zentr.  1879, 
744 ;  1882,  312 ;  Zeit.  fur.  Biol.  15,  261 ;  20, 
276 ;  Landws.  Versuchs.  Stat.  1888,  34,  303 ; 
Bosenfeld,     Zeitsoh.     Ver.     deut.     Zuokerind 

1900,  [539]   1055,  from.   J.  Soc.   Chem.   Ind. 

1901,  271).  According  to  Zuntz  and  MiiUer 
(Pfluger*s  Archiy.  1906,  112,  246),  the  proteid- 
sparing  action  of  asparagine  is  the  result  of 
a  kind  of  symbiosis,  the  iMMteria  in  the  paunch 
of  the  ruminants  decompos'n^  the  asparagine 
in  preference  to  the  protein  m  the  food.  In 
the  case  of  omniyora  and  camiyora,  asparagine 
exerts  only  a  diuretic  action  (Murok  and  Voit, 
Bied.  Zentr.  1884,  749 ;  PoUtis,  Zeit.  Biol.  1893, 
27,  492;  Mauthner,  ibid.  607;  Gabriel  and 
Voit,  ibid.  29,  115,  125;  Leyena  and  Kohn, 
Amer.  Jour.  Physiol.  1909,  28,  824;  see,  how- 
eyer,  Abderhalden,  ZeitsoL  physiol.  Chem. 
1911,  74,  481-504 ;  and  Niteche,  Beitr.  Phys. 
1914,  1,  63-89). 

Dextro-asparagine  was  disooyered  by  Piutti 
(Ber.  1886,  19,  1691)  in  the  young  shoots  of  the 
yetch  {Vicia  eatim,  Linn.)  6500  liloa.  of  yetch 
buds  yielded  20  kilos,  of  crude  asparagine,  from 
which  100  grams  of  pure  deirtro-asparaeine 
was  isolated ;    it  is  slightly  more  soluble  wan 


ASPARTIO  ACID. 


the  IffTO-  compound;  the  sohition  has  an  in- 
tensely sweet  taste,  is  dextro-rotatory  in  neutral 
or  alkaline  eolation  [al^+fi'^l"*  (Piutti,  Compt. 

rend.  1886,  103,  134),  and  levo-rotatory  in 
add  eolation;  it  forms  large  rhombic  dextro- 
hemihedral  crvstals,  a:h:e::  0-4741  :  1  :  0*8310 
(Freandler,  dompt.  rend.  1897,  125,  657).  A 
solution  of  eqou  parts  of  the  two  optically 
active  asparagines  is  optically  inactive,  but 
the  two  varieties  separate  on  crvstallisation, 
twinnine  frequently  taking  place  between  the 
left  and  right  crystals  (Piutti,  Compt.  rend. 
1886,  103,  134).  d'  and  2-Asparagine  can  be 
separated  bv  fractional  crystallisation  from 
hot  water  although  both  have  the  same  solubility 
at  20°.  The  soluoility  of  Z-asparagine,  previously 
heated,  is  at  least  aoubled  after  cooling,  and 
only  slowly  returns  to  its  original  value 
(Erlenmeyer,  Biochem.  Zeitsch.  52,  439-470). 
The  silver  salt  of  H^uparagine,  C^H^OaNtAg, 
forms  wart-like  dusters  of  crystaJs,  m.p. 
182''-183''  (decomposed)  (Abderhalden  and 
KautEsch,  Zdtsoh.  phydol.  Chem.  1912,  78, 
115-127). 

According  to  Prinffsheim  (Zeitsch.  physiol. 
Chem.  1910,  65,  89),  the  d-asparagine  found  by 
Piutti  in  the  mother  liquors  from  which  the 
t-aspara^e  had  been  isolated,  was  formed  by 
the  racemisation  of  the  l-asparagine  during  the 
process  of  evaporation  of  the  solutions.  The 
author  states  that    after  boiling  I-asparagine 

[[a]^+36-19»,  in  jr/lO  hydrochloric  acid  solu- 
tion] for  12  hours,  with  water,  and  subsequent 
fractional  crystallisation,  he  obtained  a  fraction 

that  had  [a]^-15-3'*  in  N/ld  hydrochloric  acid 
solution,  and  therefore  contained  c{-asparagine. 

In  addition  to  the  two  asparagines  abeady 
described,  there  is  a  third  form  known  as 
a-asparagine ;  it  does  not  occur  naturally ;  is 
optically  inactive,  crystallises  in  the  triclinic 
system,  a :  &  :  c= 1*5957  :  1 : 0-5668  ;  a=91*19' ; 
/9»113V12',  7«83*'  48'  (Brugnatelli) ;  and  has 
a  sp.0;r.  1*454  at  14'8*/4*  (Piutti,  Qazz.  chim. 
itaL  1904,  34,  iL  36),  and  is  not  structurally 
identical  with  the  optically  active  or  /S-aspara- 
gines.  The  three  asparagines  have  been  syn- 
thesised  by  Piutti  (Qazz.  chim.  iUl.  1887,  17, 
126 ;  1888,  18,  457)  by  the  following  methods, 
that  leave  no  doubt  as  to  the  constitution  of 
the  compounds.  By  the  reduction  of  the  oxime 
of  oxalacetio  ester  (X).EtCHt-C(NOH)-CO,Et 
with  sodium  amaleam  and  partial  saponification 
of  the  product,  Piutti  obtained  two  different 
ethyl  hydrogen  aspartates,  mdtine  at  166*  and 
200*  respectively.  The  ester  melting  at  165* 
is  identical  with  the  compound  obtained  by 
reducing  Ebert's  (Annalen,  1885,  229,  45)  mono- 
ethyl  ester  of  oximinosuccinic  acid,  which  has 
the  formula  CO,H-CH,-C(NOH)<X)|Et,  since 
on  heating  it  loses  C0|  and  forms  oximino- 
propionic  ester  CH,C(NOH)CO,Et.  It  follows, 
therefore,  that  the  ethyl  hydrogen  aspartate 
melting  at  165*  is  the  monoethyl  a-aspartate 
CO,H-CH,-CH(NH,)<X),Et,  and  the  ester  melt- 
ing at  200*  must  be  the  monoethyl  /3-aspartate 
C0,H03I(NH,)CH|<X),Et.  When  these  esters 
are  treated  with  alcoholic  ammonia,  they  are 
converted  into  the  corresponding  asparagines ; 
the  ester  m.p.  165*  gives  inactive  a-asparagint 
CO,H-CH,-CH(NH,)<X)NH„  and  the  ester 
m.p.  200*  yidcU  a  mixture  of  <{-  and  {-  /9-aspara- 


403 

From 


gines     CO,H*CH(NHa)-CH^-CONH^ 
silver  ethyl  7>oxmiino8uocmate 

XJH-CX),Et 
OHN<  I 

XJH<X),Ag 
Piutti  (Gazz.  chim.  ital.  1800,  20, 402)  obtained  a 
mixture  of  the  three  asparagines,  the  a-aspara- 
gine readily  gave  up  its  water  of  crystallisation  in 
a  vacuum,  and  fell  to  powder ;  and  the  (i-  and  U  jB- 
asparagines  could  then  be  separated  by  hand 
sortinff.  A  mixture  <rf  the  three  asparaffines 
was  also  obtained  by  the  action  of  alcoholic 
ammonia  on  the  ethyl  hydrogen  ester  of  inactive 
aspartic  acid  (Piutti,  Gazz.  ital.  ofaim.  1887, 
17,  126  ;  1888,  18,  457).  Komer  and  Menozzi 
(Gazz.  ital.  chim.  1887,  17>  171,  226)  effected 
the  synthesis  of  the  d-  and  {-  3-asparagines 
from  ethyl  bromosucdnate,  from  ethyl  fumarate 
or  ethyl  maleate,  by  the  action  of  alcoholic 
ammonia ;  and  simuar  results  were  obtained 
by  Piutti  (Ber.  1896,  29,  2069)  with  Z-bromo- 
succinamic  acid  or  maleic  anhydride. 

$-EthyUuparagine  CO,HCH(NH,)CH,- 

CONHEt,  m.p.  258*-260*,  with  decomposition, 
and  fi-allylasparagine  CO,H-CH(NH,)*GH,* 
C0*NH*C,H4,  melting  and  decomposing  at  258*- 
261*,  prepared  by  the  action  of  the  cor- 
respondins  alkylamine  on  jS-ethylaspartio  add, 
yield  optioaUy  inactive  solutions  (Piutti,  Uazz. 
ohim.  itaL  1888,  18,  478).  M.  A.  W. 

ASPARAGUS.  The  shoots  of  this  plant 
(A»paragus  offidnali*)  are  used  as  a  table 
vegetable. 

Carbo- 
Water  Protein  Fat  hydrates  Ash 
Average  composition  94*0     1-8     0*2     3-3     0-7 

The  nitrogenous  matter  of  asparagus  consists 
largely  of  amino-auceinamie  actd  CO(NH,)-CH|* 
CH(NH,)-COOH,  a  substance  known  (from  its 
disoovexy,  in  1805,  in  asparagus  shoots)  as 
aaparagine  (g.v.)* 

Coniferin  and  vanillin  have  also  been  found 
in  the  sap  and  cellular  tissue  (Lippmann,  Bear. 
1886,  18,  3355) ;  Tanret  (Compt.  rend.  1909, 
149,  48)  describes  two  new  carbohydrates  as 
occurring  in  approximately  equal  quantities  in 
asparagus  roots — cuparagoM  (CgHioO,),*H,0, 
where  nal5  or  16,  crystallising  in  microscopic 
needles,  soluble  in  water,  insoluble  in  absolute 
alcohol,  m.p.  198*-200*,  gives  no  colouration 
with  iodine,  and  does  not  reduce  Fehling*s 
solution ;  and  i^-iuparagote,  a  white,  hygroscopic 
substance  more  sduble  than  asparagose.  Both 
substances  are  hydrolysed  by  invertase,  yidding 
,  dextrose  and  Ifsvulose. 

The  seeds  of  asparagus  were  examined  by 
[  Peters  (Arch.  Pharm.  1902,  240,  53),  and  were 
found  to  contain  water  11-5,  woody  fibre  8*2, 
nitrogen  3-0,  and  oil  15-3  p.c.  Starch  was  not 
present,  but  a  reserve  cellulose  (mannan), 
capable  of  yielding  d-mannoee  on  boiling  with 
dilute  hydrochloric  acid,  occurred ;  37*5  p.c.  of 
the  weignt  of  the  seeds,  of  mannose  was  obtained. 
The  oil  was  reddish  yellow,  had  a  ep.ffr.  of  0-928 
at  15*.  and  an  iodine  number  of  137*1.    H.  L 

AflPARTIO  AOID«  AminoauccitUc  aeid 
COtH*CH,CH(NH^*COJH,  found  in  young 
sugar  cane  and  m  molasses  of  sugar  beet 
'(Scheibler,  J.  1886,  399),  in  young  shoots  of 
the  eonrd  (Schulze  and  Barbieri,  Ber.  1878, 
1 1,  710),  and  in  mulberry  leaves  (Mimuroto,  J. 
Aicric.  Tolqro,  1912,  5,  63-65),  has  been  observed 


40i 


ASPARTIO  ACID. 


in  diseased  liver  (Taylor,  Zeitach,  ph^oL  Chem. 
1901,  34,  680),  and  occurs  in  certain  glands  of 
Tritonium  nodonan ,  the  posterior,  portion  of  the 
gland  when  stimulated  secretes  an  acid  flnid  from 
which  aspartio  acid  immediately  crystaUises. 
As  an>artic  acid  is  soluble  in  sea-water,  it  is 
probaoly  employed  by  the  animal  in  destroying 
the  calcareous  shells  of  the  other  shellfish  that 
form  its  food  (Henze,  Ber.  1901,  34,  348). 

Aspartic  acid  is  prepared  by  hydrolysing 
asparagine  by  means  of  hydrochlonc  or  sul- 
phuric acid,  hme,  baryta,  lead  oxide  or  potash 
(Plisson,  Ann.  Chim.  Phys.  [2]  35,  176 ;  37, 
81 ;  40,  303 ;  Schuhse,  Landsw.  Versuchs.  Stat. 
29,  233) ;  it  is  one  of  the  degradation  products 
of  proteid  matter,  and  is  obtained  when  casein 
or  proteid  is  heated  with  (1)  dilute  sulphuric 
acid  (Kreussler,  J.  pr.  Chem.  1869,  107,  239; 
Ritthausen,  ibid.  218 ;  Fischer,  Zeitsch.  physiol. 
Chem.  1901,  33,  161 ;  1902,  35,  70 ;  36,  462) ; 
(2)  bromine  or  with  stannous  chloride  (Hlasiwetz 
and  Habermann,  Annalen,  1871,  159,  826 ; 
1873,  169,  162).  Aspartic  add  is  produced 
by  the  oxidation  of  conglutin  with  potassium 
permanganate  (Pott,  J.  pr.  Chem.  1873,  [2] 
6,  91),  by  the  pancreatic  digestion  of  fresh 
blood  fibrin  at  40''-60''  (Radziejewski  and 
Salkowski,  Ber.  1874,  7,  1060),  or  of  gluten 
(Knieriem,  Zeitsch.  f.  Biol.  1876,  11,  198) ;  and 
is  one  of  the  acid  constituents  of  Kiihne's 
*  antipeptone  *  (Kutscher,  Zeitsch.  physiol. 
Chem.  1898,  26,  196  ;  26,  110). 

The  naturally  occurring  aspartic  acid  is 
l»YO-rotatory  and  the  same  l-<upariie  acid  is 
obtained  by  hydrolysis  of  Zcevo-asparagine 
(Schiff,  Ber.  1884,  17,  2929) ;  it  crystallises  in 
rhombic  prisms,  m.p.  270^-271°  (Michael,  Ber. 
1896,  28,  1629),  is  sparingly  soluble  in  water, 
100  grams  of  water  diasolye  y  mg.  of  the  add 
at  t°,  where 

y=872+  14-l«-018124<«+00063<» 

(Engel,  CJompt.  rend.  1888,  106,  1734).  A 
solution  containing  1*873  p.o.  of  acid  is  feebly 
dextro-rotatory  below  76  ,  but  IsYO-rotatory 
above    that    temperature;     [fi]jfi'Bl^    (Wood, 

Chem.  Soc.  Trans.  1914,  105,  1992) ;  fai  alkaline 
solutions  the  substance  is  strongly  Levo-,  and 
in  adds  strongly  dextro-,  rotatory,  and  dextro- 
rotatoiy  in  aqueous  solutions  of  certain  inorganic 
salts  (Becker,  Ber.  1881, 14, 1028).  The  rotatoiy 
power  in  add  and  alkali  reaches  a  maximnm 
value  under  definite  conditions  of  concentra- 
tion (Wood,  ibid,  1914,  105,  1992;  aongh, 
Chem.  Soc.  Trans.  1916,  107,  1610).  The 
heat  of  combustion  is  387*2  Cals.,  the  heat  of 
formation  231*9  Cals.  (Berthelot  and  Andr^, 
Compt.  rend.  1890,  110,  884);  the  heat  of 
dissolution  at  16^  is  —7*26  Cals.,  heat  of  neutral- 
isation by  sodium  hydroxide  -f  3*0  Cals.  for 
the  first,  and  4-3*5  CaiB,  for  the  second  equiva- 
lent (Berthdot,  Compt.  rend.  1891,  112,  829). 
Aspartic  acid  is  readily  soluble  in  aqueous 
solutions  of  certain  mineral  salts ;  for  this  reason 
Schiff  (Ber.  1886,  17,  2929)  recommends  that 
in  its  preparation  from  asparagine  by  boiling 
with  hydrochloric  add,  the  mimmum  quantity 
(2  mols.)  of  add  be  employed,  and  the  excess 
afterwards  neutralised  by  ammonia  (1  mol.) ; 
by  adopting  this  precaution,  a  \aeld  of  90  p.c. 
of  the  theoretical  is  obtained,    for  the  estima- 


tion of  aspartio  add  in  the  hydrolysis  prodiiets  of 
protdd,  see  Foreman  (Bio-Cnem.  J.  1914, 8, 463). 
Aspartic  add  forms  salts  with  add  and 
bases,  the  copper  salt  QM^OJ^CUf^iB-fi  or 
C4H50^NCu,5H,0,  forms  pale- blue  needles  almost 
insoluble  in  cold  water  (Engel,  Ix. ;  Abderhalden 
and  WeU,  Zeitsch.  physiol.  Chem.  1911,  72,  23). 
The  calcium  salt  can  be  predpitated  quantita- 
tively by  means  of  alcohol  (Foreman,  ibid.  471). 
Tho  mono-silver  salt  mdts  216''-217^  with 
decomposition  (Abderhalden  and  Kautssch, 
Zdtsch.  physiol.  Chem.  1912,  78,  123).  A 
uranyl  salt  UOt(C«Ht04N)a,8H,0  is  formed  by 
double  decompoffltion  (Mazsucchelli  and  D' Aloeo, 
Atti.  R.  Accad.  Lined,  1912,  [5]  2,  11,  620-626). 
Aspartio  hydrochloride  C4H70^N*HC1,  softens 
with  gas  evolution  at  178^,  and  then  does  not 
alter  up  to  280""  (Philippi  and  Uhl,  Monatsh. 
34,  717-731).  Aspartic  add  is  oxidised  by 
hydrogen  peroxide  to  the  semi-aldehyde  A 
malomc  acid  which  breaks  up  into  acetaJEdehyde 
and  carbon  dioxide  (Dakin,  J.  Bid.  Chem. 
1909,  6,  409) ;  it  is  capable  of  fnznishinf  the 
nitrogen  required  for  the  devdopment  of  B-ecli 
communis  in  presence  of  mannitol  and  glucose, 
becoming  reduced  to  ammonium  succinate 
(Harden,  Chem.  Soo.  Trans.  1901,  623),  and  by 
enzyme  action  it  is  decomposed  into  f onnic, 

Sropionic,  and  succinic  acids  (Neubeig  and 
appezzuoli,  Biochem.  Zdtsch.  1909,  18,  424; 
Borchardt,  Zdtsch.  physiol.  Chem.  1909,  69, 
96 ;  Abderhalden  and  Fodor,  Zdtsch.  physiol. 
Chem.  1913,  85,  119,  130).  On  heatinffit  with 
gluooee  under  pressure  Bauer  and  Barehall 
I  obtained  succinic  add,  and  suggest  that  aspartic 
I  add  is  the  souroe  of  the  succinic  add  found  in 
meat  extract  (Chem.  Zentr.  1911,  2,  1367). 
When  aspartic  add  is  heated  at  190^-200""  for 
20  hours,  and  the  product  boiled  with  water, 
two  sparingly  soluble  anhydrides,  oetoaapariide 


NH- 


"I 


HO((X)*C*CH,*00);i 


and  ktrtupariide 


NH . 

>CH,-C0)4H 


HO(CO*C 
I 
\re  obtained,  the  more  soluble  ociotupartie 

NH, 
HO(COC-CH,-CO,H),H 


I 


and  tetraspartic  add 

NH, 

H0(C0*C*CH,*C0,H)4H 

can  be  isolated  from  the  filtrate  (Schiff,  Ber. 
1897,  30,  2449).  Dimethyl  or  diethyl  sulphate 
and  I-aspartic  acid  in  alkaline  solution  ^ve 
fumaric  add  and  alkylated  ammonia  derivativea 
(Novik,  Ber.  1912,  45,  834-860).  The  foUowing 
alkyl  esters  of  aspartic  acid  are  described  :  Mono* 
ethyl  aaparate  hydrochloride,  m.p.  199° ;  diethyl 
and  dimeihylaeparUsU  hydrochlondee,  deliquescent 
solidi  (Curtius  and  Koch,  Ber.  1885,  18,  1293 ; 
Wegscheiden  and  Frankl,  Monatah.  1906, 27, 487), 
eihyl  fi-aapartale  CO,H*CH(NH,)CH,*CO,Et, 
m.p.  200°  ;  ethyl  a-aspartate  CO,H-CH,-CH(NH  J 
CO,£t,  m.p.  166°  (Piutti,  Chem.  Zentr.   1888. 


ASPHALT. 


405 


1409).  The  methyl,  ethyl,  allyl,  propyl,  iso- 
propyl,  butyl,  iffobntyl,  and  Moamyl  hydrogen 
estera  are  dieztro-rotatoiy  at  ordinaiy  and 
Ifievo-rotatory  at  higher  temperatoree,  and 
form  sparingly  solable  copper  salts  (Piutti  and 
Maf^hi,  Qazz.  chlm.  ital.  1906,  36,  iL  73a). 
M>iethylaspartate    has    b.p.     126*^11     mm. 

pressure ;  sp.gr.  1-089  at  17** and  [J^=— 9'46° 

(Fischer,  Sitzungber,  Akad.  Wiss.  Berlin,  1900, 
48, 1062),  or  b.p.  126*»-127710  mm.,  1«)^-152'','25 
mm.  pressore,  and  forms  a  yeUow  vicrolonaie 
G^HisO^N.CioH.OcNa,  m.p.  290'*  (Schmidt  and 
Widman,  Ber.  1909,  42,  497).  Aspartio  acid 
and  ethyl  metaphosphate  yield  a  dnivatiye  of 
the  oompoeition  OeHuOfNP  (Langheld,  Ber. 
1911,  44,  2076-2086). 

Ot  the  aeyl  deriyatiyes  of  aspartic  acid,  the 
hemenendphonyl  deriyatiye  SOiPh-NH-OA 
(GO.H),  melts  at  HO"*  (Hedin,  Ber.  1891,  23, 
3196) ;  the  hippvryl  deriyatiye  NHBzCH.-CX)- 
NH'0,H,(GO.H)„  m.p.  191*'  (Cnrtins  and 
Gnrtins,  J.  pr.  Ghem.  1904,  (ii.)  70,  158); 
benzoyl  UtujMrfie  add,  m.p.  184^-185®  (corr.) ; 

has  [a]^+37-4%  feift^  (upaHie  acid  GH^ . 

GH(NHJGONH-G^JGO,H)^,0  decom- 
poses at  180^-182''  (oocr.)  (Fimher  and  Koenigs, 
Ber.  1904,  37,  4585) ;  and  the  pUsryl  deriyatiye 
OioH,Oi,N4  has  m.p.  137";  diethi^Moractiyl 
aaparkUe 

(X)OEt  -GH,  *GH-NH(GO'GH.G])GOO£t 

(Fischer  and  Koenigs,  Ber.  1904,  37,  4585; 
Bomwater,  Bee.  tray.  chim.  1917,  36, 
281)  has  mj[>.  46*»-47'*;  k.p.  139";  aspartic 
diamide  G,B;(NH,)(OONH,)„  m.p.  131^  has 
[a]^— 7^  and  giyes  the  binzet  reaction  (Fischer 

and  Koenigs,  {.e.  ).  Aspartio  aoid  resembles 
asparagine  in  its  physiological  action  (Salkow- 
sla,  Zeitsch.  phyaloL  Ghem.  1904,  42,  1207; 
Andrlfk  and  Yelioh,  Zeitsch.  Zackerind.  Bohm, 
1908,  32,  313). 

d'Atpartie  addf  obtained  by  hydrolysiB  of 
^-asparagine  (Piatti,  Ber.  1886,  19,  1694),  or 
from  {-bromosncdnio  acid  and  aqueous  ammonia 
at  —40^,  a  Walden  rearrangement  taking  place 
(Fischer  and  Raske^  Ber.  1907,  40,  1051) ;  is 
also  obtained  from  a  eolation  of  the  racemic 
^^^  [(<^+Q  aspartio  acid]  which  has  been 
innocnlated  with  a  mould  grown  on  Z-aspartic 
afdd  (Euflel,  Ck>mpt.  rend.  1887,  106,  1734). 
Benzoyl  OHupartic  add,  obtained  by  Fischer 
(Ber.  1899,  32,  2451),  hy  the  resolution  of  the 
raoemio  compound,  through  the  brucine  salts, 

has  m.p.    181°-182%  [a]^-37-6<>  in  alkaline 

solution. 

Inaetiye,  {d-\-t)Hupari%e  add,  prepared  by  the 
action  of  boiling  hydrochloric  or  mtric  acid  on 
the  product  obtained  l^  heating  the  ammonium 
salts  of  malic,  maleic,  or  fumaric  acids  (Deesaigne, 
Gompt.  rend.  1850,  30,  324);  by  heating  an 
aqueous  sohition  of  the  hydrochloride  of 
l-aspartjo  acid  at  170'*-180*'  for  some  hours 
(Michael  and  Wing,  Ber.  1884,  '[1]  2984) ;  by 
neatmg  d-  or  {-aspartic  add  with  2  mols.  KCi 
(sp.gr.  1'107)  at  170^-180%  or  from  an  aqueous 
solution  of  equal  parts  of  the  d-  and  l-  acids ; 
the  racemic  acid  czystalliBea  out  (Piutti,  Ber. 
1886,  19,  1604) ;  br  reducing  and  hydrolysing 
the  sodium  salt  of  ethyl  oadmino-ozalacetate 


(Piutti,  Ghem.  Zentr.  1888,  68).  ((2+ 1)- Aspartic 
acid  forms  small  monoclinio  prisms ;  100  grams 
of  water  dissolve  y  mg.  of  the  acid  at  t^,  where 

y:«517+21'693<-^0'165<*+00079i« 

(Engel,  (>>mpt.  rend.  1888,  106,  1734).  The 
copper  salt  GuG4Ht04N,4iH,0  is  dark-blue 
(I&igel,  I.C.),  dUAspariic  acid  pierolonaU  forms 
lon^  slender  crystals  with  equare  ends  deoom- 
posmg  at  130**  (Leyene  and  EUyke,  Bio-Ghem.  J. 
1912,  12,  127-139).  The  benzoyl  deriyatiye  has 
m.p.  164*^-165^  (oorr.),  and  can  be  resolyed  into 
its  actiye  components  by  crystalliaing  the 
bruoine  salt  (Fischer,  Ber.  1899,  32,  2451). 

H  A.  W. 
-  ASPHALT*  Oompael  bitumen.  Mineral  pHeh, 
•fetof*  fikh.  Bitumen  of  Judcea,  (Judenpeth, 
Brdpech,  Bergpech,  Ger. ;  Qoudron  miniral,  Fr.) 
A  name  given  to  the  solid  yarieties  of  bitumen. 
In  its  purest  form  asphalt  presents  the  appear 
anoe  of  a  black  or  brownish-black  solid  substance, 
possessinff  a  bright  oonchoidal  fracture.  It 
melts  at  100*,  burning  with  a  biilliant  flame  and 
emitting^a  bituminous  odour^  Sp.gr.  1-0-1*68. 
Asphalt  u  insoluble  in  alcohol  and  water,  soluble 
in  about  five  times  its  weight  of  naphtha,  and 
in  benzoL  It  is  dissolved  by  alkalis  and  alkaline 
carbonates. 

B^  dry  distiUatiou  a  jellow  oil.  Asphalt 
oil,  IS  obtained.  It  consists  of  hydrocarbons 
mixed  with  a  small  quantity  of  oxidised  matter. 
It  begins  to  boil  at  90*,  but  the  boiline-poipt 
ffradiuJly  rises  to  250*.  The  portion  boiling 
below  200*  has  the  sp.gr.  0-817  at  15* ;  that 
above  200*  has  a  sp.gr.  of  0-868  at  16*.  Both 
portions  gave  by  analysis  about  87*5  p.c.  carbon, 
11-6  p.0.  hydrogen,  and  0-9  p.c.  oxygen,  which 
is  nearly  the  composition  of  oil  of  amlier  (Volckel, 
Annalen,  88, 139).  Nitric  acid  converts  it  into 
a  resin,  having  the  odour  of  musk  and  the  taste 
of  bitter  almonds. 

Boussingault  obtained  from  the  asphalt  of 
Bechelbrunn  a  pale-yellow  oil,  pelrclene,  having 
a  faint  taste  and  bituminous  odour,  of  8p.gr.  0*891 
at  21*  and  boiling  at  280*. 

B^  heating  asmialt  to  260*  for  48  hours,  the 
volatile  oils  are  oriven  off;  a  black  solid  sub- 
stance, aepludUne,  is  obtained.  It  becomes  soft 
and  elastic  about  300*. 

The  purest  asphalt  is  found  on  the  shores  of 
the  Dead  Sea  and  in  the  pitch  lakes  of  Trinidad 
and  Mexioa  Rocks  more  or  less  impregnated 
with  bitumen,  to  which  the  name  earthy  or 
crude  asphalt  is  given,  are  found  at  the  Poldice 
mines,  Gomwall ;  near  Matlock,  Derbyshire ; 
at  Haughmond  Hill,  Shropshire;  at  the  Hot- 
wells,  ^  near  Bristol;  in  the  luneetone  near 
Glasgow;   the  freestone  near  Edinburgh;   and 

generally  throughout  tiie  Orkneys.  Large 
eposits  occur  alao  at  Seyssel,  Dtfpt.  de  I'Ain; 
at  Bechelbrunn  and  Lobsann,  Lower  Rhine ;  at 
Basteniies  and  Dax,  in  the  D^t.  des  Landes; 
in  the  Val  de  Travers,  Neuohatel,  in  Kentucky, 
and  other  places. 

Asphalt  is  separated  from  the  min«Tftlg  ^th 
which  it  is  associated  either  by  melting  the 
mass,  allowing  the  earthy  matters  to  suoside 
and  removing  the  bitumen ;  or  by  boiling  with 
water,  which  causes  the  bitumen  to  run  out  in 
the  melted  state;  or  by  the  action  of  hydro- 
chloric acid,  which  dissolves  the  calcium  car- 
bonate and  leaves  the  asphalt;   or  with  oil  of 


406 


ASPHALT. 


turpeniina,  whioh  dksolyes  out  the  bitumen. 
Murrie  (J.  Soc.  Ghem.  Ind.  3,  182)  desoxibes  the 
methods  used  in  Italy  for  the  extraction  of 
bitumen  from  crude  itsphaJt. 

The  Val  de  Travels  asphalt  contains  about 
20  p.c  of  bitumen,  and  it  onlv  requires  the 
addition  of  6  to  8  p.c.  of  mineral  or  coal  tar  to 
convert  it  into  a  plastic,  workable  mastic  of  good 
quality  for  pavements  and  hydraulic  works. 

The  modem  method  of  laying  down  asphalt 
pavement  is  to  first  prepare  a  foundation  of  con- 
crete the  surface  of  which  is  carefully  flattened. 
On  this  even  surface,  when  thoroughly  dry,  the 
melted  asphalt  is  spread  with  a  wooden  trowel, 
and  the  surface  is  finally  smoothed  over.  The 
liquid  Val  de  Travers,  llmmer's,  and  Banett's 
asphalts  used  for  this  purpose  are  all  mixed 
with  grit  or  sand,  and  so  present  rougher  surfaces 
than  those  pavinn  which  consist  of  asphalt 
alone.  Brande  (D.  R.  P.  4993, 1878)  mixes  ground 
slag  with  the  asphalt  instead  of  sand. 

Another  method  of  paving  is  to  break  up  the 
bituminous  ore,  and  neat  the  fragments  till 
they  crumble  to  powder.  A  laver  of  this  hot 
powder,  from  16  to  20  inches  thick,  is  laid  on 
ih.e  dry  concrete  and  compressed  by  stamping 
with  hot  irons. 

Artificial  anhaUf  or  gcu-tar  asphaUt  is  a 
mixtm«  of  chalk,  sand,  or  limestone  with  the 
thick,  pitchy  residue  obtained  by  evaporating 
the  more  volatile  portions  of  gas  tar.  The 
mineral  substance  must  be  heated  to  expel 
moisture  and  adhering  ^air,  and  then  added  to 
the  strongly  heated  pitch. 

In  addition  to  the  use  of  asphalt  for  pave- 
ments, water-tight  tanks,  and  coatings  for  iron 
tubes  used  for  conveying  gas  or  water,  dec,  it  is 
used  in  photography,  in  ^oto-lithogra|]^y,  and 
photo-engraving,  owing  to  the  asphalt  l)eoom- 
inff  insoluble  in  turpentine  after  exposure  to 
light.  In  the  latter  case  copper  ^tes  are 
covered  with  a  thin  coating  of  pure  asphaltum, 
or  bitumen  of  Judaea,  dissolved  in  benzene  or 
chloroform.  When  dry,  the  plato  ia  exposed 
behind  a  film  to  bright  sunlight  for  haif  an 
hour,  and  then  developed  by  first  softening  the 
soluble  portion  of  the  asphaltum  with  olive  oil, 
to  which  subsequently  a  little  turpentine  is 
added.  As  soon  as  the  lines  ace  bare  tLe  turpen- 
tine and  oil  must  be  washed  away  by  the  action 
of  water. 

For  tha  preparation  of  American  supplies  of 
asphalt  from  petroleum,  see  Day  (Min.  and  Eng. 
World,  1913;  J.  Soc.  Cham.  Ind.  1913,  32, 
1057). 

Methods  for  preparing  asphalt  for  paving 
and  other  purposes  are  described  by  Dagusan 
(D.  R.  P.  4999, 1878 ;  Dingl.  poly.  J.  232^647) ; 
Kalilbetzer  (D.  R.  P.  5646,  1878) ;  Zadig  and 
Neuberg  (D.  R.  P.  5678,  1878 ;  Dingl.  p<3y.  J. 
233,  490) ;  Clark  (Enff.  Pat.  8036,  1884  ;  J.  Soc. 
Chem.  Ind.  5, 183) ;  iLettmann  (Eng.  Pat.  12425, 
1884;  J.  Soc.  Chem.  Ind.  4,  675);  Richter 
(Siefenseid  Zeit.  23,  272 ;  J.  Soc.  Chem.  Ind. 
2,  474). 

On  the  effect  of  sulphur  in  producing  hard 
bitumen,  see  Brooks  and  Humphrey  («f.  Soc. 
Chem.  Ind.  1917,  997).  On  the  effect  of 
exposure  to  air  on  different  bitumens,  see  Reeve 
SAd  Lewis  {idem,  998). 

Native  asphalt  can  be  distinguished  from 
artificial  asphalt  by  extracting  with  carbon  di- 


sulphide,  filtering,  evaporating  to  dryness,  and 
heating  the  residue  tiU  it  can  be  ground  to  a 
fine  powder ;  0*1  gram  is  treated  with  5  ac.  of 
fuming  sulphuric  add  for  24  hours,  and  is  then 
mixed,  with  continuous  stirring,  with  10  ac.  of 
water.  If  pitoh  or  coal  tar  be  present,  the  solu- 
tion will  be  of  a  dark-brown  or  oUckish  tint ;  if 
not,  the  solution  will  be  of  a  light-yellow  colour 
(v.  Pitch). 

For  the  detection  of  petroleum-  or  coal  tar 
pitoh  in  natural  asphalt,  »ee  Marcusson  (Chem. 
Rev.  Fett  u.  Harz-Ind.  1911,  18,  47;  J.  Soc. 
Chem.  Ind.  1911,  30,  480;  Zeitsch.  angew. 
Chem.  1913,  26,  91 ;  J.  Soa  Chem.  Ind.  1913, 
32,  223) ;  Paaller  (J.  Ind.  Eng.  Chem.  1014,  6, 
286) ;  Iioebell(Chein.  Zeit.  1914, 18 ;  BCarcusson, 
ibid.  1914,  38,  813,  822). 

ASPHODEL.  The  tuberous  roots  of  Aepho- 
dXle  de  Sardaigne,  of  Asphodelus  ramoeue  (Linn.), 
and  other  species  of  the  same  ^[enus,  contain  a 
fermentable  substance  from  which  alcohol  may 
be  prepared  (c/.  Ravi^  and  Baalhache,  Compt. 
rend.  1895,  121,  659).  By  drying  and  coarsely 
grinding  the  tubers,  Landerer  obtained  a  powder 
which,  mixed  with  water,  formed  a  strong  glue. 
Badoil  and  Lienders  obtain  tannin  from  the 
pulp  leftafter  the  extraction  of  the  akohoL 
A8PIDIN,  ASPIDINOL  v.  Filix-mas. 
A8PID0SAHI1IE,  ASPIDOSPEBIIATDIE, 
and  ASPIDOSPEBHDnS  v.  QuBBft^oEo  al- 
kaloids. 

ASPIRATORS.  Aspirators  are  used  to  draw 
air  or  other  gases  through  any  apparatus  con- 
nected with  them,  ana  were  probably  first 
employed  by  Brunner  in  his  amdysee  of  air, 
1830-1840  (Pogg.  Ann.  20.  274;  24,  569; 
81,  1).  The  process  of  aspiration  or  inhaling 
of  air  is,  however,  most  common,  being  neoessar}* 
to  the  life  of  animals  and  to  the  ventilation 
of  buildings,  mines,  &c.,  to  chance  the  air  so 
that  it  may  support  life.  In  otner  analyses 
of  air  by  Dumas  and  Boussingault,  an  exhausted 
globe  or  jar  was  used  as  an  aspirator  (1841, 
Ann.  Chim.  Phys.  [3]  iii.  257).  When  a  vessel 
is  emptied  of  liquid,  air  must  enter  to  take  its 
place,  and  the  common  aspirator,  in  its  variouji 
forms,  is  a  vessel  with  two  openings,  the  lower 
to  serve  as  outlet  for  the  water  or  liquid,  and 
the  upper  as  inlet  for  the  air  or  gas  to  be  aspirated. 
With  suitable  fittings  a  siphon  may  be  used 
instead  of  the  lower  opening,  or  the  apparatus 
may  be  modified  into  a  bell-jar  standing  over  a 
basin  or  larce  jar,  the  air  being  drawn  in  through 
the  nock  of  tnc  bdl- jar.  This  is  Mohr's  aspirator, 
which  is  sometimes  poised  like  a  gasholder  to 
facilitate  filling  and  emptying  of  the  bdl-jar 
(Mohr,  Lehrbuch  der  Titrirmethode»  1855, 
Brunswick). 

From  their  introduction,  aspirators  were  used 
not  only  to  draw  in  gases  through  apparatus  and 
reagents  employed,  at  a  regulated  rate,  but  also 
to  measure  the  gases  so  manipulated  by  simply 
measuring  or  weighing  the  liquid  run  out  of  the 
aspirator.  For  approximate  readings  aspirators 
of  glass  may  be  graduated,  and  those  of  metal 
may  be  provided  with  gauge  glasses. 

Numerous  forms  of  tne  simple  aspirator  have 
been  invented  b^  Brunner,  Regnault,  Mohr,  and 
others.  Fig.  1  is  perhaps  the  form  in  most  fre- 
quent use,  and  is  generally  of  glass,  plain  or 
craduatod.  'Fig,  2  is  a  very  convenient  form, 
oescribed  by  Uemens  Winkler  (Industrie-Gase^ 


ASPIRATORa 


W1 


--  I 


bdov,  oD  tiw  aide  tnbt,  la.naeful  in  Blliiig  the 
Minntor  vrilh  mter.  Fig.  3  ii  the  fonn  often 
nted  in  Iceting  the  guoa  from  obemioal  works. 
It  is  nrnply  a  cnbiod  or  lectatWuUr  box  mttde 
ot  sheet  leul,  witb  ft  gndnated  gsage  giua,  ud 
csn  be  opened  at  a  Ui  fiU  it  with  wal«f  •  _ 

Douoie  atpiralort.  In  short  operations  the 
simple  Bipinttor  lequirea  no  refilling  nor  special 
attentioa  after  the  taps  ar«  WBjnitod.    To  obviate 


control  of  the  operator  and  rariee  between  the 
heif^t  ot  one  bottle  and  a  vorj  small  miDimum. 

Tigs.  6  and  6  show  an  anangemenl  deviaod 
by  the  author,  which  has  oertain  advantages. 
The  bottlaa  a  and  s  aro  connected  as  ahoun, 
being  raised  and  lowered  alternately.  The  four- 
way  tap  c  (shown  larger  in  Fig.  6)  has  its  index 
I  turned  towards  the  upper  bottln  in  aspirating 
and  towards  the  lon-cr  buttle  in  blowing.  It  is 
made  from  a  good  gas  tap  by  boring  up  the 
oentre  of  the  plug  at  F,  leading  out  the  hole  at 
*  — M  pieoe  of  metal  H  is  then  fitted  snd 

diagonally   where   the  holes  oros^,   a 

pieoe  of  tubing  k  soldered  on  to  the  Eocket  of 
the  tap,  and  an  index  I  above  the  plug. 

Paiaflin  wax  is  used  to  adjuat  the  botUce  for 
exact  measurement,  and  to  obtain  a  fine  adju.  ' 
D,  as  well  as  above,  by  a 


ibbcr  tube  ttunugli  the 
vid  filing  it  m  Die  proper  position 
before  the  wax  is  run  in,  and  alter  the  wax  ii 
quite  solid  this  tube  is  drawn  out.  The  passAKs 
■bould  be  eurred,  so  that  on  emptwng  the  bottle 
of  water  the  water  runs  out  to  the  mark  at  D. 
The  bottles  are  then  adjusted  by  weighing  thrir 
content  of  water  between  the  mark*  and  addini 
or  removing  paraffin  till  at  the  standanl 
(empenture  and  pressure  they  hold  the  exact 


¥ia.  3. 


Fro.  4. 


the  InoonTenience  of  stopping  to  change  or  refill 
thiat  would  be  nsoe^san'  in  longer  operations, 
Brutma',  Boisgirand,  Dancer,  Huoncke,  and 
othMi  have  contrived  double  aspiraton  so 
neeted  that  each  vessel  is  alternately  above  and 
below,  and  one  or  other  always  ready  for  use. 
The  aspirating  bottles  may  be  mounted  on  s 
oommoa  axis  as  in  Danoer's  swivel  HSpiratoi 
Kg.  4 (Chem.  News,  1864,  10,  296).  Theacswivel 
aspirators  are  very  convenient,  butthediffereoce 
of  water-level  in  the  two  bottles  is  not  under  the 


liK 


quaatitv  of  water  corresponding  to  the 
required.  In  saooeeaive  weiehin^  of  bottlM  so 
adjusted  the  differences  uould  not  exceed 
0-1  gram.  To  avoid  loosening  of  the  wax  from 
direct  contact  with  the  glass,  the  bottles  should 
be  preserved  from  changes  of  temperature  and 
from  mechanical  vibration,  &o. 

Cwulani  or  avlmnalie  atpiralora.  Instru- 
ments of  this  class  have  been  invented  by 
Guthrie  (Phil.  Mag.  [41  16,  64)  and  by  Bonny 
(Winkler  s  Technical  Gas  Analysis,  trans,  by 
Lunge,  17).  In  each  of  them  a  pipe  from  Ihe 
water  supply  leads  a  oonstant  stream  ot  ivatet 
into  a  veesel,  which,  when  full,  is  emptied  by  a 
siphon,  whose  tube  is  of  larger  aiie  than  the 
supply  pipe.  The  arrangement  thus  acts  on 
the  principle  of  the  intermittent  siphon,  and 
the  veasd  is  filled  and  emptied  at  regular 
intervals.  In  Benny's  instrument  theae  are 
refiistered  by  a  simple  mechanism,  and  the  tot&l 
volume  passed  is  known  on  measuring  the 
volnme  passed  in  one  operation. 

The  Sprengel  and  injector  pnmpa  may  bo 
used  s#  ootutuit  aspirators  (v.  Fil,tbb  fumpB). 
By  means  of  a  collecting  box  attached  below  the 
pump*  to  allow  the  gas  and  water  to  escape  at 
different  lev^  the  gas  may  be  measured  by 
nsaing  it  through  a  small  gaa  meter  (Davis, 
J.  Soo.  Chem.  Ind.  211). 

J.  Grossman  (Winkler's  Industrie- Gase, 
21S)  has  invented  a  small  mercurial  aspirator, 
on  the  principle  of  the  Geiasler  pump,  with  two 
teservous,    v^oh   are   alternately   raised    and 


works,  fto.,  Angus  Smith,  Davis,  and  others 
have  used  small  pear-shaped  aspiraton  of  mdia- 
rabber.  Theee  are  emptied  by  simply  sqnenins 
in  the  hand.  The  air  eacapes  by  a  valve,  of 
which  the  ilmplert  is  a  imaU  slit  In  tho  rubber 


ASPIRATORS. 


oomieotiqg  taba^  optoing  ootvards  like  a  I 
Bvuen'f  vsIto.  The  robber  feoorering  ite  form 
di»wB  *  oertein  Tolome  of  gas  through  the  test- 
ing apparatus,  and  it  is  easy  to  ascertain  approzi- 
matdy  the  total  volame  id  gas  corresponding 
to  any  giTen  number  of  times  the  aspirator 
has  been  filled.  Another  larger  aspirator  of  this 
class  is  (d  beUows  form,  like  a  concertina,  the 
folding  part  being  of  indiarnbber.  This  aspi- 
rater  IS  frequently  used  for  filling  by  displace- 
ment jan  or  bottles  with  gas  to  be  tested.  The 
common  stngle-bairel  air  pump  or  apparatus, 
on  the  same  principle,  is  slso  applied  in  this 
mmxtrkmr  as  an  aspiratoT. 

At  the  Britisk  Association  Belfast  meeting* 
1874,  the  late  Txoi.  Andrews  showed  how  an 
ordinary  wet  gas  meter  could  be  converted  into 
an  aspirator  By  applying  motive  power  to  the 
hollow  axis  of  the  dnim,  tiiereby  causing  it  to 
suck  in  air  at  the  inlet  side  and  at  the  same  time 
to  measure  the  air  on  the  meter  index.  Using 
mercury  as  liquid  in  a  cast-iron  meter,  a  similar 
arrangement  forms  the  basis  of  the  Barr.  and 
Stroud  air  pump  applied  in  the  eraouation  of 
bulbs  for  electric  lighting  lamps  (J.  800.  CSiem. 
Ind.  1896,  640 ;  Bug.  Pat.  13188,  July,  189^. 
_  X.  Jr. 

AflPDUlf.  Trade  nun?  for  moetfl  salioylio 
acid  0«H4(CX)OH)0'CO'CH„  used  as  an  anti- 
rheumatic, and  in  the  treatment  of  headaches, 
fererish  colds,  Ac.  Is  hydrolyaed  In  the  intes^ 
tine  forminffsodinm  salicylate. 

AflPIROTHEN.  Trade  name  for  amino 
acetphenetide  acetyl  salicylate. 

A8QUIRR0L.  Trade  name  for  merouiy 
dlmethoxidet 

A88AYI1IG.  Assaying, '  the  tria]  of  metals,' 
a  term  ori^^inally  applied  only  to  the  testing  of 

Sold  and  silver,  is  now  usually  extended  to  the 
etermination  of  the  quanti^  of  the  valuable 
metal  in  an  ore  or  metallurmoal  product.  It  is 
also  sometimes  taken  to  include  the  estimation 
of  any  element  which  may  prejudicially  affect 
the  value  of  the  ore,  but  it  it  more  usual  to 
discuss  this  tocher  with  such  work  as  the 
complete  analysis  of  ores,  slags,  furnace  materials, 
fuel,  &<f.,  under  the  heading  of  *  metallurffical 
analprsis.'  A  brief  account  of  some  of  &ese 
sections  is  given  below. 

The  art  of  assaying  11  of  great  antiquity. 
The  use  of  the  touchstone  for  testins  gold  m 
India  was  referred  to  by  Mathuranatna  (Hist, 
of  Hindu  Qiemistry,  by  Ray,  ii.  231),  and  was 
probably  known  in  the  Qreek  world  at  least 
as  early  as  B.a  700,  when  the  first  dectrum  or 
gold-silver  coins  were  manufactured.  At  anv 
rate  the  touchstone  found  its  way  into  Qreek 
mythology.  The  testing  of  sold  alloys  by 
cementation  was  describMl  by  Hiny,  by  Strabo, 
and  in  the  eighth  century  ▲.d.  by  the  Arabian 
Geber,  who  was  also  familiar  with  the  method 
of  cupellstion,  and  is  reputed  to  have  discovered 
nitric  acid.  The  parting  assay  of  gold  with  the 
aid  of  this  acid  is  referred  to  in  a  decree  of 
Philippe  de  Valois  in  the  year  1343,  confirming 
its  use  in  the  SVenoh  Mmt.  Alloys  of  silver 
with  copper  were  tested  by  observing  the  degree 
of  blacxening  caused  b^  heat  in  the  Roman 
Mint  under  the  Repubhc  (Roohon,  Easais  sur 
les  Monnoies,  17,  1792). 

It  is  probable  that  ores  were  not  valued 
except  by  inspection  until  the  Middle  Ages. 


The  first  clear  references  to  ore-aesaytng  are 
to  be  found  in  the  anonymous  tittieoooks 
entitled  Probierbuchlein,  which  were  published 
in  Germany  eariy  in  the  sixteenth  century,  and 
in  the  writings  ci  Biringncdo,  Agricda,  and 
Ercker  in  the  same  century,  list  the  art  was 
evidently  regarded  by  these  authors  aa  already 
ancient  at  the  time  at  which  th^  wroCcL  Erdcer, 
writing  at  Frankfort  in  1680,  describes  the 
fire-assays  not  only  of  seversl  different  kinds  of 
gold  and  silver  ores,  but  also  of  the  ores  of 
copper,  lead,  tin,  antimony,  iron,  mercury,  and 
bismuth.  Assaying  l^  means  of '  wet  methods,' 
volumetric,  sravimetric,  and  eleotrolytic,  is  of 
comparative^  recent  introduction  (excepting 
the  parting  assay  of  gold),  but  has  now  in  peat 
part  supeneded  the  .ancient  processes  involving 
the  use  of  furnaces. 

AimiPliii^.— -Whether  the  material  to  be 
assayed  is  a  portion  of  a  vein  underground,  a 
heap  of  broken  ore,  pjgs  of  metal,  or  a  delicate 
piece  of  jeweUery,  in  everr  ease  a  representative 
sample  must  be  obtained.  In  the  case  of  ore 
in  sUiu  undemound,  pieces  are  taken  from  a 
number  of  differBnt*)p<Mnts  and  either  mixed  or 
examined  senarately.  Ore  which  can  be  moved 
is  reduced  in  hulk  either  l^hand  or  l^maoiiiiieiy, 
and  is  generally  crushed  finer  between  each 
successive  reduction  in  bulk.  Every  second, 
fifth,  tenth,  or  twentieth  shovelful  or  car-load 
may  be  set  aside  as  a  sample,  or  the  whole  heap 
may  be  made  into  a  perfect  cone,  wUoh  is 
fiattened  and  divided  into  four  quarters  aloQg 
two  diameters.  Two  opposito  quarters  are 
removed  and  mixed,  and  the  process  of  '  coning 
and  quartering  *  repeated  as  often  as  necessary. 
A  heap  or  vat  of  ore  or  tailings,  which  must 
be  sampled  without  beiiu;  movra,  is  pieroed  at 
rcffulany  spaced  intorvab  by  a  ■*»»pi«"g  tube 
which  resembles  a  cheese-taster,  and  withdraws 
a  cvlindrical  sample  extending  to  the  bottom 
of  tne  vat  or  heap. 

In  automatic  sampling  machines,  which 
are  much  used  in  Western  America,  the  crushed 
ore  is  made  to  slide  down  an  inclined  plane  or 
rotating  cone,  and  a  portion  of  the  stream  of 
ore  is  deflected  and  set  aside  as  a  sample.  Those 
machines  are  preferred  which  momentarihr 
take  the  whole  stream  of  ore  at  regular  intervab 
of  time.  A  stream  of  pulp  is  sampled  by  the 
passage  through  it  from  siae  to  side  or  from  top 
to  bottom,  at  regular  intervals  of  time,  of  a 
receptacle  which  is  large  enou£[h  not  to  overflow 
while  the  sample  is  being  mteroepted.  Hie 
pulp  sample  is  then  filtered  and  dtuxL  Further 
reduction  in  the  laboratory  is  effected  bv  ooning 
and  quartering  or  by  a  machine  such  as  the 
riffle  or  sampUng  tin,  which  consists  of  a  series  of 
metal  troughs  arranged  side  by  side  and  fastened 
at  equal  distances  from  each  other.  A  stream  of 
ore  let  fall  on  it  is  in  part  retained  by  the  troughs 
and  in  part  passes  tboush. 

The  final  grinding  of  the  ore  is  effected  by 
means  of  an  iron  pestle  and  mortar,  or  of  a  large 
hammer  with  a  curved  face  sliding  on  an  iron 
plate  (or  buchboard),  or  by  some  form  of  roUins 
or  grinding  mill.  The  crushed  ore  is  passed 
through  a  sieve,  the  finenew  of  which  varies 
according  to  the  ore  and  the  method  of  assay. 
If  a  panning  test  is  required,  a  SO-mesh  sieve 
(u€,  one  with  20  holes  to  the  linear  inch)  suffices. 
For  most  fusions,  e.^.  dry  lead  assay,  a  OO-meah 


nara  is  osed.  Gold  lint  ak  onuhed  through  an 
80-  or  100-meah  slevci,  aad  in  the  oaae  of  tin  ores 
and  of  telluride  orea  ol  gold,  the  brat  results  arc 
obtniued  by  oains  120'mesh  sieves.  Before  it 
oan  be  pMsed  tfirough  ti  fine  siove,  the  oie 
moat  be  dried,  so  that  the  moitltiTe  la  determined 
OQ  coarsely  cmahed  ore  by  drying  at  100*  on 
a  water-batb.  or,  if  the  dry  materisl  is  not  likedy 
to  be  afieoted  in  &ny  way  by  ft  somevhftt  higher 
lemperatme,  it  is  he«ted  bn  a  sand-bath.  In 
orauiiag  rich  gold  and  litver  ores,  mint  sweep- 
ing!, £».,  pieosa  of  metal  are  found  which 
beoome  flftHened  ont  and  are  caught  on  the 
■are.  ThcM  ' melatUcs ' an  treateaseparately, 
■nd  tlM  Taioe  oaknJated  on  the  weight  of  ore 
from  which  they  were  derived. 

The  dried  and  omahed  sample  is  tbotonghly 
mixed  bv  means  of  a  spfttala  m  ft  baun,  or  on 
rubber-cloth,  before  the  portion  required  for 
assay  "it  weighed  ont.  If  stored  in  a  bottle  or 
tin,  the  movement  of  the  veaael  causes  tiie  heavy 
partiolee  to  aeltle,  so  that  the  material  at  the 
bottom  becomes  riohet  tbaa  that  at  the  top. 

Ingots  of  metal  are  sampled  by  cats  taken 
from  the  comers  or  edges,  as  in  the  case  of 
refined  gold  and  ai>ver,  or  by  drillings  from  a 
number  of  different  spots,  as  is  sometimes  done 
in  the  ease  of  iron  and  steal  and  of  onreflned 
gold  and  silver  Pigs  of  argentiferous  lead  are 
sometimes  sampled  by  drilliugB  or  saw  cuts- 
Base  gold  and  silver  ingots,  and  in  many  oases 
ingota  of  steel  and  pigs  of  lead,  are  melted  and 
atirred,  and  ft  portion  dipped  ont  and  granulated 
by  pouring  into  water,  or  cast  into  a  little  ingot. 
Coin*  are  sampled  in  various  ways,  silver  ooina 
being  sehiom  uniform  in  composition.  The 
mi^sat  method  applicable  to  all  is  to  roll  thent 
ont  and  ont  them  into  a  large  number  of  little 
pieces,  so  that  all  parts  of  the  coin  may  be 
Rpreaented  in  tiie  portion  taken  for  assay.  This 
method  is  adoptM  in  the  Pbiladelphla  Mint, 
bat  is  not  in  general  nae,  other  more  oomplioated 
methods  being  preferred-  Cold  and  silver  wares 
are  nsnally  pickled,  and  are  richer  on  the  snrfaoe 
than  in  we  interior.  In  sampling  them,  it  is 
accordingly  necessary  to  remove  the  oateide  by 
scraping  and  then  to  scrape  off  a  portion  of  metw 
tor  assay. 

The  prtlimimtrji  erami'nolion  of  ore*  include* 
aanftd  inspection,  which  i*  all  th*  more  wefnl 
if  some  comparatively  large  pieoea  are  inelnded 
in  the  aamfde.  "nie  proximate  oanstittienl«, 
snch  Bs  quartz,  pyritea,  magnetite,  galena,  Jw., 
are  thns  observed,  and  the  proportions  in  which 
they  are  pieauut  icaghly  estimated,  this  infonuft- 
tioo  beins  teqoiied  m  making-up  furnace  chu'gea. 
fVeqnenuy  a  oonoeotntion  test  is  made  in  a 
miner's  pan  (a  Bat-bottomed  sheet-iron  pan 
about  20  inches  in  diameter,  and  3  or  4  inches 
deep,  with  sloping  dides)  or  a  vanning  ^ovel,  or 
in  aoT  baain,  pan,  or  even  clock-gla**  avaikble. 
For  uiiB  pnriNiae  a  pmiion  of  26  giamrer  more 
ia  weighed  out,  itimd  and  ahaken  wil^  water 
by  a  oiionlsr  motion  on  the  shovel,  and  " 


»  of  jerks,  the  denser  particles 
are  thrown  up  and  uie  lighter  onea  washed 
down  the  shoveL  The  oonoentratee  are  ex- 
aminal  with  a  lea*  or  separated,  dried,  and 
weighed,  or  -  tceated  with  acid,  or  examined 
by  means  of  the  blowpipe,  or  in  other  wayi^  in 


riNG.  400 

order  to  determine  thi  preseuoo  or  absence  of 
elements  likely  to  iiiterfvre  with  the  method 
of  assay  chosen.  The  vanning  ahovel  is  used 
particularly  with  tin  ores,  but  may  be  applied 
to  anj[  others.  Panning  testa  aie  eepeoudly 
useful  in  the  examination  of  gold  ores,  but  are 
also  required  to  determine  ^e  nature  of  the 
'  mineru '  or  compounds  of  the  heavy  metals 
in  almost  all  ores.  The  teat  may  be  applied 
to  half  a  gram  ct  ors  In  ft  wktch-glass,  if  no  more 
Ban  be  spared. 

The  furnaces  used  by  sssayers  are  the  muffle 
fnmaoe,    and    the    mdting    or    wind-fnmaoe. 


having  an  arched  top.  It  is  heated  by 
ooal  eoke,  oU  sa*  or  eleotnoity  UnlBes 
vary  m  size  aoooramg  to  the  amount  of  work 
to  be  done,  but  those  used  at  the  Royal  Hmt  may 
be  oonsidered  full  size.  Beotional  views  of  one 
of  these  fomaoea  aie  shown  in  R^  1  and  3. 
The  muffle  a  is  14)  inohes  long,  8^  tnches  wide, 
and  5  inohea  high,  inside  measurements,  with 
walls  about  |  inch  Uiick.     He  mouth  ia  oloeed 


no.  t. 

by  the  firebrick  s  and  by  a  slJiUng  plate  raatfng 
im  1.     Air  enter*  through  hole*  in  the  ilidiag 


410  ASSA 

plfttfl  and  pMWs  out  at  the  back  throaab  Uie 
tube  o,  wluoh  h^B  a  ilidiiw  dunper  and  leade 
into  the  main  flue.  The  fuel  is  ordinary  gai, 
Bupplied  bj  a  rov  of  bunaen  bumers  D,  and 
oompletA  oombustioil  of  the  gaa  may  be  aided 
by  clay  fireballs  BurrODDding  the  muffle.  The 
flues  X  ■  oarry  off  the  wMte  gasea.  The  fur- 
Dooa  valla  oonaitt  of  firebrick  bound  with 
iron  and  coTei«d  with  a  thiok  layer  of  nue- 
neaia  and  aibeatoa  to  check  radiation.  No 
ohimnej  stack  oi  forced  draught  ia  required  for 
tbiafumMW. 

A  Bwtttiw  Jwmaet  adapted  iot  the  om  of 
ookB  aa  fnel  and  niitable  to  make  fusions  in 
aMay  operations,  ia  diown  in  section  in  Fig.  3, 
in  vbiob  a  is  the  fireplace,  b  the  flne,  o  the 
Mhpit,'  D  the  daraper,  and  ■  the  firodoor.  The 
most  useful  site  of 

the     firaplaoe     ia  p 

about     U     inches  i 

square,  and  about  f 

10  inobee  in  depth  f 

from  the  firebars  i 

to  the  flue,     llie  | 

fumaoe  is  built  of  ^ 

briok    and    lined  ^ 

with  firebriok.    It  ^ 

ia     bound'    with  ^ 

covered  with  ii 


pla 


olt< 


1  fur- 


Fia.  & 


rods.  Qas-meltins 

natural  drmugbt 
or  unng  a  blast  of  air  are  teas  common.  Fluiing 
oruciblet  consist  of  fireclay  or,  in  the  assay  ui 
galena,  of  wrought  iron.  Tbey  are  of  difierent 
sizes  and  shapes,  the  beet-biown  being  the 
Batterwa  (round,  Comiiih,  and  triangle). 
French,  Hessian,  and  Colorado  crucibles,  the 
last-named  being  used  for  making  fusions  in  the 
muffle,  a  common  practice  in  America.  Moat 
onioiblei  require  careful  annealing  before  being 
used.  Ruasting  dishes  made  of  ficeolay  are 
for  the  rooaling  of  oresj.  fireclay  aoorityina 
dishes  or  scorifiers  are  used  in  the  proccM  of 
acorification  ;  cupels  of  various  ahapee  and  sizea 
are  made  of  oompressed  bone-aah  or  magnesia. 
and  are  required  in  the  assay  of  the  precious 
metals.  The  bone-ash  cupels  may  be  made  by 
the  aaaayer,  and  must  I>e  carefully  dried  before 
use.  Hafnuaia  cupels  are  uau^y  bought 
readv-nu^ 

Xbe   Ttagtntt   used   in   fire 


fiuiee,  Boenta  for  lednoiDg,  oxidiung, 

id  ^aolphuriaing,  and  oovers  to 

t  of  the  cnieible  from  the 


protect  the  conte 

aoUon  of  the  air,  furoaoe  gases,  &c  Generally 
■peaking,  an  ore  conaiata  of  compounds  of  a 
heavy  metal  or  mettjs  (the  mineral),  together 
with  a  quantity  of  earthy  materials,  auoh  m 


metallic  form,  and  to  inoorporate  the  remainder 
ot  the  ore  in  a  fusible  slag,  through  which  the 
partiolee  of  metal  may  settle  to  the  bottom, 
whete  tliey  ooUeot  in  the  form  of  a  bnttou. 
Sometimes  a  legolua  or  matte  (sulphide  of  a 
heavy  metal)  or  a  speise  (arsenide  of  a  Ijeavy 
metil)  foima  a  Mparate  \Kjtt  between  the  metal 


and  the  ilag,  and  a  cover,  say.  of  common  salt, 
may  be  provided  which  is  lighter  ^lon  siUoate 
alage  and  fioats  on  the  top.  On  bretjiing  open 
a  cold  crucible  in  which  a  fusion  has  been 
made,    there    are,    tberefore,    frequently   four 

The  principal  fiuzea  need  am  eodium  car. 
bonate,  which  forma  fusible  mixtures  witii  odd 
(ailioeoua)  ore«,  and  also  acts  as  a  deeulphuriser, 
oonverting  pyrites  into  a  mixture  of  sulphides  of 
iron  and  sodium  which  does  not  form  a  regnlns, 
but  is  dispersed  through  the  alag.  Cartmiate 
of  soda  ia  now  geaerally  used  in  the  anbrdrotia 
form,  Na,CO^  but  the  bicarbonate,  which  girea 
up  half  ita  carlxmic  acid  without  fnaioo  ia  also 
suitable.  Soda  erysttUs  give  up  their  water  of 
oryalaUisatJon  with  ebullition,  and  are  cot 
suitable  unlesa  previa  ualy  dried.  Basic  ore* 
require  borax,  which  forma  fusible  mixtures 
with  oxidea  of  iron,  lime.  &o. ;  and  increaaea  the 
fluidity  of  mo«t  chaises.  CiystalliBed  borax 
powder  on  besting  swells  up  enormously,  gives 
up  ita  water  and  fuses  into  a  glaas.  The  aweUing 
may  oocaaion  loss  in  the  aaaay  if  the  crucible  is 


weight  of  ordinary  borax.  Litha^o  is  a  neetul 
Hui,  especially  for  oxides  of  iron,  oopper,  &c., 
but  attacks  and  oorrodes  the  amcibles.  Fhior- 
spar  ia  sometimea  used,  especially  for  phoq>hales. 
Sand  is  often  required  to  protect  Uie  cmoible 
from  attack  by  basic  erea. 

The  reducing  agents  are  carbon  (charcoal 
powder  or  lampblack).  Sour,  tartar  or  argol 
(crude  hydrogen  potassium  tartrate),  ud 
oooaeionalJy  potassium  cyanide.  One  part  of 
charcoal  is  about  equal  to  two  parts  of  flonr 
or  five  of  tartar,  but  tartar  also  acts  as  a  flux, 
being  converted  by  heat  uito  carbon  and 
potdasium  carbonate.  Black  flux  ia  a  i«dndng 
mixture  mode  bv  deflagrating  one  part  of  niln 
with  two  and  a  half  parts  of  argoL 

The  chief  oiidismg  agents,  which  are  alea 
deaulphuriaers,  are  hot  air.  htharge  or  red  load, 
and  nitie.  Iron  is  often  used  aa  a  deeulphuriaiiig 
agent.  The  ordinary  mateiiala  used  as  covera 
are  borax  and  common  salt. 

The  baiaiKa  oTid  loeigliU  do  not  differ,  as  a 
rule,  from  those  used  in  ordinary  obemioal 
anatyaia,  the  most  notable  exoeption  being  in 
the  case  of  those  used  in  the  aaaay  of  gold  and 
silver.  The  proportion  of  these  metala  praseat 
in  ores  is  reported  ia  troy  ounoea,  ^Mony  wei^ta. 
aiLd  grains  pet  ton,  or  sometime*  m  oonoe*  and 
deoimals  or  in  penuyweighta  and  decimals. 
The  weight  of  ore  taken  for  assay  accordingly 
contains  aa  many  milligrama  aa  there  are  ouneea 
troy  in  a  ton  (29,166  in  a  ton  of  2000  lbs.,  and 
32.606  in  a  ton  of  2240  lb*.).  This  weight  of 
29166  grams  is  called  an  auay-ton  (or  A.T.), 
■nd  boxes  of  weights  made  up  c/assay-tona  Mid 
decimola  are  uaed  by  many  assayera.  Then 
the  gold  extracted  fR>m  the  sample  of  ore  ia 
we^hed  in  milligrame.  and  can  be  reported 
wiuout  calculation.  In  the  aaaay  oE  gold 
bullion  the  weiAhta  commonly  range  nom 
'  1000 '  downwarda,  where  1000«0-S  gram  or 
some  other  unit  auch  aa  S  grains.  Much 
tedious  calculation  ia  avoided  by  thua  maik- 
ing    the    weights    so    that     thur    fooe-value 

S'rea  at  onoe  the  result  of  the  assay.      Again, 
assaying  ailvai  by  pndpitation  as  chlwid* 


ASSAYING. 


411 


(India  Mint  method,  see  p.  419),  since  18*815 
grains  of  pure  silver  are  contained  in  25  grains 
of  chloride,  it  follows  that  if  18*815  grams  of 
an  alloy  be  always  taken  for  assay,  and  the 
resulting  chloride  be  weighed  out  with  a  series 
of  weights  the  largest  of  which  is  marked  1000, 
and  is  equal  to  25  grains,  and  the  others  are 
marked  correspondingly,  then  the  subsidiary 
weights  of  this  series  will  indicate  the  result  of 
the  assay  without  calculation.  A  similar  series 
can,  of  course,  be  arranged  for  any  special 
purpose. 

The  balances  used  for  weighing  sold  and  silver 
in  bullion  assays  are  Uj^ht  and  dSicate,  taking 
about  2  grams  as  their  maximum  of  weight, 
and  turning  to  one  hundredth  of  a  milligram. 
Usually,  one  division  of  the  ivory  scale  is  made 
equal  to  0-05  mg.  Balances  for  weighing 
the  parted  gold  in  ore  assays  are  still  more 
delicate.  The  maximum  weight  which  they 
can  carry  is  only  1  gram  or  even  less,  and  they 
turn  with  one-hundriMith  or  in  some  cases  only 
one  five-hundredth  of  a  milligram.  Milligram 
and  half-milligram  riders  are  used,  but  the 
final  reading  is  always  baaed  on  the  deflection 
from  the  zero  position  of  the  pointer,  measured 
by  the  number  of  divisions  on  the  ivory  scale 
covered  by  the  swing.  At  the  present  day  short 
beams  of  6  inches,  4  inches,  and  even  8  cm.  in 
length,  are  in  use,  so  that  the  balances  are  very 
rapid  in  action  in  spite  of  their  sensitiveness. 

In  quantitative  blowpipe  work  on  gold  and 
silver,  it  has  been  found  possible  to  dispense 
altogether  with  a  delicate  balance,  and  to  use 
an  ivory  scale  (Plattner's  scale),  by  which  the 
diameter  of  the  bead  of  metal  is  accurately 
measured.  The  principle  has  been  extended 
in  the  assay  of  poor  materials,  and  beads  of 
mioroecopio  dimensions  are  placed  on  the  stage 
of  a  microscope  and  measured  by  means  of  a 
micrometer  eyepiece.  In  this  way  L.  Wagoner 
(Trans.  Am;  Inst.  Mining  £n^.  xxxi.  1901, 
798)  obtained  a  dose  approximation  to  the 
weight  of  beads  of  silver  of  0-02  mm.  in  diameter, 
which  weighed  about  0*00004  mg. 

The  aTOve  summary  has  special  reference  to 
the  leouirements  of  a  laboratory  for  making 
dry  or  fire  assays.  For  wet  assays,  the  apparatus 
and  reagents  are  those  of  the  ordinary  analytical 
laboratory  («.  Asalywb), 

In  all  methods  of  assaying,  wet  or  dry, 
time  must  be  considered  as  well  as  aoouiacy. 
It  is  sometimes  important  to  arrive  at  a  result 
in  the  course  of  an  hour  or  lees»  and  some  of 
the  methods  described  are  intended  for  such 
emergencies,  when  extreme  accuracy  must  be 
sacrinced.  It  is  also  necessary  to  observe 
that  assay  methods  are  intended  to  be  com- 
parative, and  wherever  it  is  possible  check  assays 
on  similar  materials  of  xnown  composition 
should  be  made  side  by  side  with  the  assays  of 
ores  or  other  bodies  requiring  examination,  and 
a  correction  applied  to  the  results.  In  the 
following  PW8»  only  methods  in  common  use 
in  assay  offices  are  described.  The  methods 
of  ordinary  analysis  are  generally  omitted  or 
made  the  subject  of  brief  reference. 

Ahiminliim.  There  are  no  special  methods 
of  assaying  the  ores  of  this  metaL  The  silicates 
are  broken  up,  and  the  silica  removed  as 
usual,  and  the  acid  solution  of  the  bases  is 
treated  so  as  to  separate  the  metals  contained 


in  it.  Aluminium  is  precipitated  and  weished 
as  phosphate  AIFO4,  or  oxide  Al,Oa*  It  is 
sometimes  weighed  as  oxide  tcM^ether  with  oxide 
of  iion  Fe,0„  and  also  PsOg»  if  these  con- 
stituents are  present  in  the  ore.  The  last 
mentioned  constituent  is  of  course  combined 
as  phosphate.  The  phosphorus  and  iron  are 
then  determined,  aluminium  beins  estimated 
by  difference  (Low's  Technical  Methods  of  Ore 
Analysis,  1st  ed.  22). 

Antimony.  The  antimony  in  ores  may  be 
determined  by  fusion  with  cyanide  of  potassium 
or  with  iron  (avoiding  excess)  and  black  flux, 
but  the  results  are  unsatisfactory.  The  sulphide 
of  wntimony  in  an  ore  may  also  be  approxi- 
mately determined  by  charging  500  ^ms  of 
ore  broken  to  nut-size  into  a  day  crucible  with 
a  perforated  bottom.  This  crucible  is  fitted  into 
another  of  about  the  same  size,  and  the  joint ' 
carefully  luted.  A  cover  is  also  luted  on,  and 
the  whole  is  slowly  raised  to  a  red  heat.  The 
sulphide  of  antimony  fuses  and  liquates  into 
the  lower  crucible,  from  which  it  can  be  detached 
when  cold,  and  weighed.  The  fused  sulphide 
of  antimony,  if  pure,  contains  71*7  p.c.  of  the 
metal.  The  valuation  of  antimony  sulphide 
ores  is  usually  effected,  according  to  Bedford 
McNeill  (Berenger's  Assaying,  Ilth  ed.  226), 
by  having  recourse  to  the  ordinary  smelting 
operation,  which  is  to  be  used  in  treating  the 
ore  on  the  laise  scale.  Charges  of  about  20  kilos, 
of  ore  are  used  for  the  valuation. 

The  wet  methods  of  estimation  of  antimony 
in  ore  are  far  more  accurate  than  those  referred 
to  above.  The  ore  is  fused  with  sulphur  and 
sodium  carbonate,  and  then  dieted  with 
water.  A  solution  of  an  alkabne  sulpho- 
compound  of  antimony  is  thus  obtained,  from 
whicn  a  mixture  of  antimony  and  arsenic  sul- 
phides and  free  sulphur  is  precipitated  by  the 
addition  of  dilute  hydrochloric  acid.  After 
the  arsenic  has  been  separated,  the  antimony 
sulphide  is  weighed  or  is  oxidised  by  fuming 
nitric  acid,  and  weighed  as  Sb,04.  Ores  may 
also  be  attacked  by  hydrochloric  acid.  The 
antimony  in  the  separated  sulphide  may  be 
estimated  volumetrically,  dissolving  the  sul- 
phides in  hydrochloric  acid  and  chlorate  of 
potash,  warming  to  expel  the  chlorine,  adding 
an  excess  of  potassium  iodide,  and  titrating 
with  thiosulphate  of  soda  (J.  Soo.  Chem.  Ind. 
XT.  255). 

Anenie.  The  determination  of  arsenic  in 
ores  and  metallurgical  products  is  usually  made 
bv  Pearoe's  method,  which  consists  in  fusing 
about  0*5  gram  of  the  ore  with  5  grams  of  a 
mixture  of  equal  parte  of  sodium  oarbonate 
and  nitre,  dissolving  out  the  soluble  arsenates  of 
the  alkalis  and  precipitating  the  arsenic  in  a 
neutral  solution  by  means  of  silver  nitrate. 
The  raecipitated  brick-red  silver  arsenate 
Ag|As04  is  filtered  off,  dissolved  in  nitric  acid, 
and  the  silver  in  it  determined  by  Volhard's 
thiocyanate  method.  The  amount  of  arsenic 
pesent  can  then  be  calculated  (Low's  Ore  Ana- 
lysis, 41).  Small  quantities  of  arsenic  in  metals 
and  minerals  may  be  separated  by  distillation 
with  ferric  chloride  ana  calcium  chloride  in  a 
hydrochloric  acid  solution,  the  distilled  arsenious 
chloride  being  condensed  in  a  vessel  of  cold  water 
(Berenicer's  .^saying,  384).   (For  arsenic  in  steel, 

p.  4L7.) 


412 


ASSAYING. 


Bismuth,  if  present  in  an  ore  in  the  metal  Ho 
state,  may  be  determined  by  liquation,  th« 
method  of  procedure  being  similar  to  that  used 
in  liquating  sulphide  of  antimony  {q.v.).  The 
bismuth  in  an  ore  may  also  be  determined  by 
fusing  it  with  fusion  mixture,  common  salt,  and 
cyanide  of  potassium.  These  methods  are 
inexact,  and  bismuth  is  usually  determined  by 
being  weighed  as  Bi^Ot  after  precipitation  as 
carbonate,  or  as  BiOCl  on  a  weighed  filter  or  a 
Goooh  crucible  after  being  c&ied  at  100®. 
Bismuth  in  metallic  lead  is  precipitated  and 
weighed  as  BiOQ,  and  in  metallic  copper  it 
is  (&tected  by  the  colour  given  to  lead  iodide. 
(For  estimation  of  bismuth  in  copper,  see 
p.  414.) 

Chromiain  occurs  in  chrome-iron  ore  and 
sometimes  in  other  iron  ores,  in  pig-iron  and 
in  steel.  Small  quantities  of  chromium  in  iron 
ores,  after  separation  from  other  metab  and 
earths,  are  precipitated  by  lead  acetate  in  an 
acetic  acid  solution,  and  weighed  as  PbCrO^, 
or,  in  the  altematiTe,  reducM  by  sulphurous 
acid  and  the  chromium  precipitated  from  the 
green  solution  by  means  ot  ammonia  and 
weighed  as  Gr^O,.  Chrome-iron  ore  is  assayed 
by  a  volumetno  method  based  on  the  oxidation 
ol  f erroua  iron  by  chromium  in  the  form  of 
chromate.  The  chromium  is  oxidised  by 
fusion  with  peroxide  of  sodium  (J.  Iron  and 
Steel  Inst  xlviiL  153).  The  ferrous  iron  is 
added  in  the  form  of  a  weighed  amount  of  ferrous 
ammonium  sulphate  or  of  a  weighed  amount  of 
metallic  iron  dissolved  in  sulphuric  acid.  The 
excess  of  ferrous  iron  present  in  the  solution  con- 
taining the  chromium  is  titrated  with  per- 
manganate. Chromium  in  steel  is  precipitated 
and  weighed  as  chromium  phosphate  (Chem. 
News,  lyiL  1888,  163),  or  as  onromic  oxide 
CrgO,. 

Cobalt    i9ee  Nickel,  p.  418. 

Copper.  The  principal  ores  of  copper  aro 
(a)  native  copper;  (6)  sulphide  ores,  copper 
pyrites  or  yellow  ore,  embeebite  or  purple  ore, 
grey  copper  ore,  &c. ;  (e)  oxidised  ores,  malachite, 
silicate  of  copper,  &o.  The  treatment  of  copper 
ores  results  m  the  production  of  copper  matte 
or  regulus  contahiing  from  30  to  60  p.c.  of  copper, 
and  cement  copper  or  copper  precipitate,  'con- 
taining 70  p.c.  or  more  of  metaUic  copper. 
In  addition  to  these  materials,  ordinary  com- 
mercial standard  copper,  refined  copper,  and 
the  alloys  of  copper  require  to  be  assayed. 

The  chief  methods  in  use  are  as  follows  : — 

(I)  Dry  or  Cornish  assay,  long  used  in  con- 
nection with  the  sale  of  copper  ores,  but 
applicable  chiefly  to  mattes  and  rich  sulphide 
ores.  It  is  especially  unsatisfactory  when 
dealing  with  poor  ores,  but  gives  low  results  in 
all  oases,  the  loss,  according  to  Beringer,  ransing 
from  2  p.c.  of  the  copper  present  in  the  richest 
materials  to  33  p.c.  of  the  copper  in  2  p.o.  ore. 
It  consists  in  fusing  the  calcmed  regulus  for 
metallic  copper  and  refining  the  copper.  Rich 
oxidised  ores  are  fused  for  metal  at  once.  The 
amount  of  ore  taken  for  assay  is  400  grains, 
but  with  rich  material  only  200  grains  or  even 
100  grains  are  taken.  The  fluxes  vary  with  the 
nature  of  the  ore,  in  which  there  may  be  too 
much  sulphur  and  iron,  as  in  copperpyrites,  &c., 
or  too  little,  as  in  grey  copper.  Ae  following 
are  examples  of  the  charges ; — 


lOre   . 
\Nitro 
Lime 
Fluorspar 
Glass 
Borax 
Hnmatite 
Sulphur 
Argol 


A.  Copper  pyittss  B.  Gref  oopperaro 


200  grains 
50 
200 
200 
150 
150 


100  grains 


200 

200 

150 

150 

1&-20 

25-30 

30 


» 

*» 
I* 


The  charge  is  fused  in  a '  largo  copper '  crucible 
at  a  low  red  heat,  which  is  gradually  raised. 
After  about  15  minutes  the  charge  is  poured  into 
a  conical  mould,  and,  as  soon  as  the  slag  is 
solid,  it  is  taken  up  by  tongs,  dipped  into  water, 
and  allowed  to  dry.  When  treated  in  this  wcy, 
the  slag  breaks  up  readily.  The  n^ulus  is 
detached  by  a  hammer  and  crushed  to  powder 
in  an  iron  mortar.  It  should  be  leddish-brown 
in  colour  and  contain  about  60  p.c.  of  copper 
and  20  p.c.  of  iron.  It  ia  roasted  in  a  Cornish 
crucible  in  the  melting  furnace  or  in  a  roasting 
dish  in  the  muffle,  at  a  low  but  increasing 
temperature,  with  continuous  stirring  at  first. 
When  *  sweet,'  t.e.  not  smelling  of  sulphur,  at 
a  full  red  heat,  it  is  mixed  with  a  little  charcoal 
powder,  and  re-roasted  to  decompose  sulphates. 
It  is  then  crushed  asain,  if  necessary,  and  fused 
in  the  same  cruciSe  with  aigol,  borax,  and 
sodium  carbonate.  A  high  temperature  is 
required,  and  the  charse  is  poured  in  al)out 
16  minutes.  The  slag  is  detached  and  cleaned 
by  a  second  fusion  with  more  argol  and  sodium 
carbonate.  The  *  coarse  copper '  obtained  in  this 
way  is  refined  by  beins  charged  into  a  very  hot 
crucible  and  meltecL  The  impurities  are 
oxidised  by  the  air  and  form  a  nnff  of  oxides 
round  an  eye  of  copper,  llien  refining  flux, 
which  consists  of  a  ctena^ted  mixture  <»  nitre, 
argol,  and  common  salt,  is  added,  and  2  minutes 
later  the  copper  is  poured,  and  if  it  i^  found 
to  be  at  *  tough  pitch,*  it  is  weighed.  The  slag 
contains  copper,  and  must  be  cleaned.  (For 
full  details  of  the  method,  sts  l'ercy*s  Metallurgy, 
L  1861,  464-478.) 

(2)  Ekclrolytie  assay  of  copper.  The  weight 
of  ore  taken  for  assay  depends  on  its  richness, 
a  convenient  amount  of  metallio  copper  for 
electro-deposition  being  from  0*1  to  0*6  gram. 
When  uflinff  this  method  or  any  of  the  other 
wet  methoos,  the  copper  must  not  be  brought 
into  solution  and  usually  separated  from  o&er 
metals.  Oxidised  ores  may  require  merely  to 
be  treated  with  hydrochloric  add.  Sulphide 
orss,  mattes,  copper  precipitate,  &o.,  are  at- 
taclud  by  nitric  acid,  evaporated  to  dryness, 
and  taken  up  by  hydrochlorio  acid.  Coippet 
slaffs  are  fused  with  sodium  and  potassium 
carbonate  (fusion  mixture),  and  a  little  nitre, 
and  are  then  digested  with  water  and  hydro- 
chloric acid.  The  copper  is  precipitated  from 
its  hydrochloric  acid  solution  by  means  of 
sulphuretted  hydrogen  or  (alter  evaporation 
with  sulphuric  acid)  by  sodium  thiosulphate, 
and  the  sulphides  are  filtered  off  and  redissolved 
in  nitric  acid.  The  copper  may  also  be  separated 
from  other  metals  by  adding  sulphuric  acid  to 
the  nitric  or  nitrohydrochloric  acid  solution  and 
boilii^  off  the  volatile  acids.  The  solution  is 
cooled,  diluted  and  filtered,  and  the  copper 
precipitated  at  a  boilinff  temperature  with 
aluminium  foil    For  the  dectrolytio  assay,  tho 


ASSA7INQ. 


418 


flohition  obtained  in  one  of  these  ways  is  diluted, 
wanned,  and  filtered  into  a  200  co.  flask,  and 
made  np  to  abont  100  o.a,  of  whioh  from  2*6  to 
5  p.0.  should  be  nitrio  add.  Platinum  electrodes 
(spiral  and  weighed  oone  or  cylinder)  are  then 
fuaoed  in  position,  and  a  current  from  two 
Daniell  cells  in  series  is  passed  through  for 
16  or  17  hours.  The  cylinder  is  remoTed  from 
the  colourless  solution,  washed  with  water  and 
afterwards  with  alooholf  dried  in  a  water-OTen, 
and  weighed.  The  copper  precipitate  should 
be  safanon-red  in  colour.  The  solution  still 
contains  a  little  copper,  which  is  estimated 
oolorimetricalhr,  ammonia  being  added,  and  the 
colour,  after  mtration,  compared  with  those  of 
standard  solutions  containing  known  amounts 
of  copper.  Silver,  meroury,  bismuth,  arsenic, 
and  antimony  interfero  wiUi  the  process,  being 
deposited  with  the  copper.  Meroury,  however, 
is  separated  on  dissolvmg  the  sulphides  in  nitrio 
add.  Bismuth  turns  the  copper  dark  grey,  but 
is  not  deposited  until  most  of  the  copper  has 
been  thrown  down.  Arsenic  and  antimony 
darken  the  copper  depodt,  but  may  be  driven 
off  by  heating  to  dull  redness.  Lead  is  de- 
podted  at  the  anode  as  a  dark-coloured  coating 
of  PbOf,  and  may  be  wdghed  in  that  form.  The 
electrolytic  assay  is  suitable  for  all  materials 
containing  copper  (c/.  Elbcibolttio  analysis). 

By  rapidlv  rotating  the  cathode  a  coherent 
depodt  can  be  obtained  even  when  a  strong 
currant  of  10  to  12  amperes  per  100  sq.  cms.  oi 
cathodic  area  instead  of  the  usual  current  of 
0-6  to  1 0  ampere  is  used.  The  time  required  for 
the  depodtion  of  the  copper  may  thus  be 
shortened  to  a  few  nunutes  (Amer.  J.  Sci  1903, 
zvlL  320,  zviii  56 ;  J.  Amer.  Chem.  8oo.  zxv. 
886 ;  Chem.  Soc.  Trans,  zd.  373). 

(3)  The  voUumetrio  aaaay  of  copper,  Thero 
an  two  main  processes — ^the  potasdum  cyanide 
and  the  iodide  methods.  Soth  aro  in  wide 
nse  in  the  assay  of  ores,  alloys,  &a  In  pre- 
parinff  to  use  these  methods,  the  copper  is 
orougnt  into  solution^  uid  may  be  separated 
from  other  metals,  ^.,  as  already  described, 
with  any  further  precautions  necessary  to 
remove  special  impurities.  With  ordinazy 
pyritic  ores,  however,  containing  no  dno,  diver, 
niokd,  or  cobalt,  it  is  sufficient,  in  preparing 
for  the  (yanide  process,  to  heat  the  oro  gentlv 
with  concentrated  nitric  acid  to  which  a  little 
sulphuric  add  has  been  added.  It  is  then 
diluted,  an  excess  of  ammonia  or  of  NagGOg 
added,  the  bulk  made  up  to  some  convenient 
amount  such  as  300  ca,  and  the  solution  titrated 
with  potasdum  qyamde.  The  blue  solution  is 
decolourised,  and  when  overdone  changes  to  a 
straw-yellow  colour.  The  results  are  affected 
by  tune,  temperature,  degree  of  dilution,  and 
1^  the  amounts  of  ammonia  and  of  ammonium 
salts.  The  conditions  of  the  check  assays  on 
pun  copper  and  those  on  ores,  fta,  must 
thenfon  oe  identical,  and  ferric  hydrate,  for 
example,  must  be  present  either  in  both  or  in 
neither.  If,  however,  the  solution  is  free  from 
ammonia  and  ammonium  salts,  and  is  made 
alkalme  with  sodium  carbonate,  the  effects  of 
time,  temperature  and  degree  of  dilution  an 
much  reduced,  while  ferric  salts  do  not  affect 
the  result  unless  present  in  such  amount  as  to 
mask  the  end  reaction.  The  standard  cyanide 
solution*  which  decomposes  somewhat  rapidly. 


contains  about  42  grams  KQy  to  the  litn,  and 
100  cc  of  this  is  equivalent  to  1  gram  of  copper. 
The  reaction,  according  to  Beringer,  is  npn- 
sented  by  the  equation : 

CuS04+4KCy=2KCyCuCJyg-fK^04. 

The  quantity  of  copper  usually  present  in  an 
aspay  is  about  0*6  gram.  At  the  finish  the  effect 
of  an  addition  of  0'6  cc.  of  cvanide  is  readily 
observable.  Zinc,  silver,  nickel,  and  cobalt 
interfen  with  the  assay,  and  must  be  nmoved 
befon  titration. 

In  the  iodide  method,  the  alloy  or  the  sul- 
phide of  copper  separated  from  the  on  is 
dissolved  in  nitric  add,  evaporated  almost  to 
divness  in  order  to  expel  nitrous  fumes,  and 
diluted.  The  nitrous  products  may  also  be 
destroyed  by  urea.  The  solution  is  then  filtered 
if  necessary,  and  carefuUy  neutratised  with 
sodium  caroonate,  avoiding  excess.  One  cc.  of 
acetic  add  is  then  added,  which  should  be  enough 
to  redissolve  the  predpitated  copper.  Next, 
after  cooling  the  nask,  an  amount  of  about 
6  grams  of  potasdum  iodide  crystals  is  added 
(or  not  less  than  ten  times  the  weight  of  the 
copper  present) ;  the  solution  is  diluted  to  a 
fixed  amount,  say  60  cc ;  and  the  liberated 
iodine  is  at  once  titrated  with  a  solution  con- 
taining 39*18  grams  sodium  thiosulphate  (equiva- 
lent to  10  grams  of  oopper)  to  tne  litre  The 
reactions  an  npresented  by  the  equations: 

2CuS044-4KI=Cu,T,-f2I+2K,S04 
2Na,S,0,+2I=2NaI+NagS40,. 

When  the  yellow  colour  is  almost  discharged, 
2  CO.  of  frosh  starch  solution  is  added,  and  the 
addition  of  the  thiosulphate  continued  drop 
by  drop  until  the  blue  colour  disappears  and 
does  not  rotum  within  2  or  3  minutes.  The 
effect  of  one  drop  or  0*06  cc  of  standard  solu- 
tion, equivalent  to  0*6  mg.  copper,  is  obseirable. 
The  solution  is  standanused  with  pun  electro- 
lytic copper.  Ferric  acetate,  arsenic,  lead,  and 
large  quantities  of  sodium  acetate  may  interfen 
wiw  the  titration.  According  to  J.  W.  West- 
moreland (Beiinger's  Assaying,  441),  sodium 
acetate  counteracts  the  interference  of  arsenic 
and  bismuth,  and  the  bad  effect  of  large  quanti- 
ties of  sodium  acetate  is  nmoved  by  doubling 
the  amount  of  potasdum  iodide  added.  Iron,  if 
present,  is  precipitated  by  anmionium  phosphate 
(J.  Soc  Chem.  Ind.  v.  48).  Instead  of  nentralidng 
with  sodium  carbonate  and  acidifying  with  acetic 
acid,  an  addition  of  20  c.c#f  a  saturated  solution 
of  dnc  aoetete  may  be  made  (A.  H.  Low). 
In  order  to  dispense  with  the  large  quantities 
of  expensive  potasdum  iodide  required  in  the 
ordinary  method,  Moir  proposes  (J.  Chem.  Met. 
and  Mng.  Soc  of  S.A.,  voL  xviiL,  Nov.  1917, 
p.  133)  to  add  a  dight  excess  of  sodium  thio- 
sulphate to  the  usual  very  faintiv  add  solution  of 
cupric  acetete,  and  to  titrate  back  with  NliQ- 
iodme,  of  which  only  a  small  quantity  will  be 
required. 

The  oolorimetrio  method  of  assaying  copper 
is  sometimes  used  in  the  case  of  very  poor  ores, 
or  generally  whenever  the  quantity  of  copper 
present  is  smalL  Reference  nas  been  maoe  to 
it  above. 

Examination  of  commercial  copper.  Electro- 
lytic and  Lake  copper  aro  ffenerauy  nearly  pun, 
but  some  of  the  metel  sold  oonteins  as  much  as 


414 


ASSATINO. 


2  or  3  p.o.  of  impuritiet.  The  most  im- 
portant of  theae  axe  anenio,  lead,  niokel«  oxygen, 
and  phoaphorna ;  but  antimony,  biamuth,  oo&lt, 
gold,  iron,  aeleniom,  ailver,  aalphur,  and  tellurium 
may  alao  be  preaent.  The  impuxitiea  to  be 
looked  for  in  copper  which  haa  paaaed  a  high 
conductivity  test  are  mainly  bismuth,  selenium, 
and  tellurium.  Arsenic  and  phosphorus  are 
separated  as  iron  arsenate  and  phosphate 
mixed  with  acetate.  Gold  and  antimony  are 
separated  by  dissolving  the  copper  in  nitric 
acid,  and  suver  is  precipitated  as  chloride  or 
bromide  from  a  nitric  acid  solution.  It  may 
be  collected  in  a  precipitate  of  lead  sulphate. 
Nickel  ia  left  in  aolution  by  precipitating  copper 
electrolytically,  or  by  sulphuretted  hydrogen 
in  an  add  solution.  Lead  is  detected  by  the 
blackening  of  the  anode  in  the  electrolytic 
assay,  anu  ia  eatimated  aa  aulphate  or  ohromate. 
The  methods  of  determining  oxygen  may  be 
classified  in  two  groups  (J.  Inst  Metals,  viL  1912, 
232)  :— 

1.  The  estimation  of  cuprous  oxide. 

2.  The  eatimation  of  total  oxygen. 

In  Hampe'a  method  (Zeitach.  anaL  Chem. 
xiiL  1874,  216)  of  estimating  the  amount  of 
cuprous  oxide  in  copper,  the  copper  is  dissolved 
in  cold  dilute  silver  nitrate  solution  free  from 
acid.    The  equations  are  aa  follows : — 

Cu+2AgNq,=Cu(NOg),+2Ag 
3Cn,0 + 6AgN0,+ 3H,0 

c=2Cu(NO,),+2Cu,(HO),NO,-t-6Ag 

The  copper  existing  as  CujO  is  found  by 
multiplying  the  copper  in  the  precipitate  by  j. 
The  results  are  satisfactory. 

Total  oxygen  is  estimated  by  heating  thin 
strips  or  bright  turnings  of  copper  to  redness  in  a 
stream  of  hydrogen  and  weighing  the  water 
produced,  or,  better  still,  the  residual  copper. 
In  the  latter  case,  aa  mirrors  of  arsenic,  antimony 
and  bismuth  may  be  formed,  it  is  neoessaiy  to 
weigh  the  tube  and  copper  together. 

Bismuth  is  separated,  according  to  Berinser, 
by  precipitation  by  sodium  bicarlK>nate.  After 
redissolvmg  in  sulphuric  acid,  it  is  boiled  with 
sulphurous  acid  and  potassium  iodide,  and  the 
bismuth  in  the  yellow  solution  estimated 
colorimetricaUy.  Tellurium  and  selenium  (J. 
Amer.  Chem.  8oc.  xvii.  280)  are  precipitated  as 
iron  tellurite  and  selenite  by  additions  of  iron 
nitrate  and  ammonia.  The  prepipitate  is  re- 
dissolved  in  HCl,  tartaric  acid anapotash  added, 
and  a  current  of  sulj^luretted  hydrosen  passed. 
The  selenium  and  tellurium  are  subsequently 

Eredpitated  by  a  current  of  sulphurous  acid  in  a 
ydrochloric  solution,  and  parted  by  boiling  with 
potasdnm  cyanide. 

Gold.  Gold  is  generally  in  the  metallic 
state  in  its  ores,  either  in  the  form  of  grains, 
scales,  pellets,  &c.,  in  loose  alluvial  gravels,  or 
in  various  forms  embedded  in  quartz  or  other 
gangue  in  veins.  It  is  frequently  associated 
with  iron  pyrites,  blende,  &c.,  but  the  only 
native  compounds  are  the  tellurides.  Besides 
these,  the  auriferous  materials  to  be  assayed 
comprise  tailings  or  residues  of  ores  after  treat- 
ment, copper  bottoms,  pig  lead,  unrefined 
bullion,  which  contains  diver,  copper,  and  other 
metals,  fine  (t.e.  refined)  gold,  and  the  commercial 
alloys  used  for  coinage,  plate,  &c.  The  assay 
^f  gold  ores  and  alloys  is  made  with  greater 


exaotneaa  than  oth«r  aasaya,  owfaig  to  the  high 
value  of  the  metaL 

A  panning  assay,  or  concentration  teat  ia 
carried  out  aa  deaoribed  on  p.  409.  The  oon- 
oentratea  oonaiat  of  *  black  aand '  or  oxidea  of 
iron,  titanium,  fto.,  aulphidea  and  arsenides, 
and  sometimes  |prains  of  platinum.  Fiee  cold 
is  sometimes  visible,  and  is  collected  by  grinding 
in  a  mortar  with  mercury,  panning  out  the 
amalcam,  and  recovering  the  gold  by  distilling 
off  the  mercury  or  diasolvins  it  in  nitric  add. 
In  dther  case  the  gold  must  be  parted  from  the 
silver  as  described  on  p.  416.  The  panning 
assay  of  alluvial  gold  depodts  is  usually  reported 
in  grains  of  fine  gold  per  cubic  yaird,  which 
weigha  about  3000  lbs.,  or  H  short  tons.  In 
the  panning  assay,  from  60  to  90  p.c.  of  the 
gold  in  the  ore  is  usually  recovered. 

Ordinary  gold  ores  are  assayed  by  (1)  the 
fudon  or  crucible  method,  or  (2)  the  scorifioation 
method.  In  the  cntcibU  assay,  the  ore,  crushed 
through  an  SO-mesh  or  finer  sieve,  is  mixed  with 
litharge  or  red  lead,  charcoal,  or  argol,  and  the 
necessary  fluxes,  and,  fnaed  in  the  mefting  furnace 
or,  aa  in  Western  America,  in  the  muffle.    The 


amount  of  ore  taken  ia  usually  1  A.T.  (aaaay- 
ton,  see  p.  410),  but  is  sometimes  only  i  A.T., 
and,  in  the  case  of  poor  tailings  in  which  there 


are  only  a  few  grains  of  gold  per  ton,  as  much  aa 
12  A.T.  is  taken  and  fused  in  sevcval  chama, 
the  gold  being  finally  collected  into  one  lead 
button.  The  fluxea  vary  with  the  nature  of 
the  ^  ore.  The  following  are  typical  charjg^ 
Bubject  to  very  large  variations  to  meet  special 


oaaea: — 


A.  StUeioni  ore 

B.  Baslo 

(grey  or  white 

oxidised 

G.  Pyiltic 

wlthaUtUe 

ore  (red  or 

ore 

pyiites,  Ac) 

brown) 

Ore  . 

1A.T. 

1  A.T. 

1A.T. 

Litiiarge  or 

redle^ 

1    » 

1     » 

I    M 

Charcoal   . 

1*2-1*6  grams 

2*0  grains 

0-1  gram 

Sodium 

• 

car Donate 

IIA.T. 

26      „ 

1  A.T. 

Borax 

6-10  grams 

10      „ 

10  grams 

Sand  is  added  to  B  and  0  if  necessary  for  the 
protection  of  the  crudUa  from  corrodon.  The 
borax  is  usuidly  not  mixed  with  the  oharse, 
but  is  added  aa  a  cover  or  charged  in  after  tiie 
fudon  haa  begun.  The  charge  is  well  mixed 
and  put  into  a  cold  crucible,  which  it  must  not 
make  more  than  two-thirds  full,  and  pieoea  of 
hoop  iron  or  two  or  three  tenpenny  naila  are 
embedded  in  the  mixture.  The  crucible  ia 
gradually  heated,  a  red  heat  beginning  to  appear 
after  cbout  10  minutes,  and  a  dull  rra  heat  not 
being  attained  for  30  minutes  or  more.  Tranquil 
fusion  results  in  40  or  60  minutes  from  the  time 
of  charging  in.  The  pot  is  then  lifted  out  of 
the  furnace,  the  nails  removed,  and  the  charge 
poured  into  a  conical  mould  or  allowed  to  oool 
m  the  pot,  idiich  is  afterwards  broken.  When 
cool,  the  lead  button  is  detached  from  the  slag 
by  hammering.  The  button  should  weigh  at 
least  26  grams.  If  less  than  this  amount  of 
lead  is  reduced,  a  fre^h  charge  is  made  up  con- 
taining more  charcoal,  and  any  change  is  made 


ASSAYING. 


415 


in  the  fluxes  whi<rfi  may  seem  desirable  from  the 
appearance  of  the  slag.  If  the  load  is  hard  or 
brittle,  owin^  to  the  presence  of  impurities,  it  is 
usually  scorified,  sometimes  with  the  addition 
of  fresh  lead,  before  being  cupelled,  as  other- 
wise the  loss  of  ffold  is  increased. 

The  slag  wSl  contain  gold  and  a  foriion 
silver  if  the  conditions  during  fusion  are  lavour- 
able  to  oxidation  of  the  metius.  For  this  reason 
it  is  better  to  reduce  almost  all  the  litharge 
than  to  leave  some  of  it  in  the  slag,  and  the 
more  readily  oxidised  metals — ^iron,  manganese, 
&a — must  be  reduced  to  their  lowest  oxides^ 
ferrous  oxide,  &a  Practically  all  the  copper, 
nickel,  and  other  readily  reducible  metals  will 
then  be  in  the  lead  button.  In  the  case  of  ores 
oontaining  much  copper,  this  is  a  disadvantase, 
entailing  loss  of  gold  in  cupellation,  and  tne 
copper  may  be  removed  from  the  ore  by  treat* 
ment  with  acid  before  fusion  (with  some  loss  of 
silver)  or  Iaw  quantities  of  litharae  (6  A.T.  of 
PbO  to  1  A.T.  of  ore)  may  be  adctod,  and  only 
a  small  part  of  it  reduced.  In  the  latter  case 
the  slag  contains  gold  and  silver,  and  is  cleaned 
by  a  second  fusion,  with  the  reduction  of  more 
lead.  A  similar  method  of  fluxiug  is  used  for 
telluride  ores,  an  excess  of  litharge  in  the  slae 
preventing  tellurium  from  entering  the  leaa 
/  Duttoo.  Antimonial  and  arsenical  gold  ores 
are  sometimes  roasted  with  coal-dust  in  a  re- 
ducing atmosphere,  in  order  to  remove  the 
antimony  or  arseuic  as  a  sulphide  before  fusion. 
An  alternative  method  is  to  fuse  with  much 
litharse  and  enough  nitre  to  oxidise  the  antimony 
with  we  formation  of  antimoniates.  Sulphides 
maybe  roasted  in  air  before  fusion. 

The  lead  button,  rounded  by  hammering,  is 
placed  on  a  hot  cupel  in  the  mufie  (see  p.  403), 
which  is  kept  at  a  full  red  heat.  The  lead  melts 
and  oxidises,  and  the  litharge  and  other  oxides 
are  absorbed  by  the  cupel,  the  gold  and  silver 
being  lelt  as  a  bead  (or  '  prill ')  on  the  surface. 
If  the  bead  is  large  and  contains  much  silver,  it 
must  be  cooled  gradually  to  prevent  it  from 
'  spitting '  on  solimfication,  by  which  jnrt  of  the 
metals  might  be  lost.  The  bead  is  cleaned, 
weighed,  mkttened,  and  parted  by  dissolution  in 
boilmg  nitric  acid  in  a  porcelain  crucible  or  test- 
tube.  If  less  than  two  parts  of  silver  are  present 
to  one  of  gold,  the  metals  are  not  parted  com- 
pletely, silver  being  left  in  the  gold,  and  it  is 
convenient  to  have  a  greater  proportion  of  silver 
present.  It  is,  therafore,  often  necessary  to 
melt  the  bead  wiUi  more  silver,  the  proportion 
varying  with  the  sice  of  the  bead,  as  f oUows : — 

Weight  of  ifold  Silver  required  for  parting 

10  miUigrams  40  milligrams 

0-2        „         or  less  2  „ 

A  little  extra  silver  is  permissible,  but  if  too 
much  silver  is  present,  there  is  a  tendency  for 
the  sold  to  break  up  into  very  fine  particles, 
which  are  di£Scult  to  wash  without  loss.  The 
separation  of  these  minute  jMrtides  is  avoided  ' 
by  dropping  the  bead  into  boiling  acid,  sp.gr.  1*2, 
when  the  parting  will  be  completed  in  a  few ' 
seconds.  The  parted  gold  is  washed  free  from 
silver  nitrate,  Aa,  and  is  made  firm  and  co- 
herent for  weighing  by  being  annealed  at  a  red 
heat.  (For  weights,  balances,  &c.,  s<e  p.  410.) 
The  silver  is  estimated  by  difference.  The 
litharge,  fluxes,   Ac.,  must  be  tested  for  silver 


and  gold  by  running  blank  charges  without 
ore. 

In  scorification  about  0*1  or  0-2  A.T.  of  ore  is 
mixed  with  30  or  40  grams  of  granulated  lead, 
and  transferred  to  a  dry  scorifier.  The  charge  is 
covered  by  a  similar  amount  of  granulated  lead, 
and  from  0*5  to  1  gram  of  borax  is  sprinkled  on 
last.  The  scorifying  dish  is  then  charged  into  a 
mufile,  which  has  Men  raised  to  a  temperature 
of  1000''-1100^  or  considerably  above  that 
required  for  cupellation,  and  the  muffle  is  closed. 
Ae  soon  as  the  charge  is  melted  down,  the  muffle 
is  opened.  The  lead  now  oxidises,  and  the 
litharge,  fonning  a  rinff  of  slag  round  the 
scorifier,  oxidises  the  smphides,  &c.,  and  slags 
off  the  earthy  materials  in  the  ore.  As  oxidation 
proceeds,  the  litharge  encroaches  on  the  'eye  * 
of  metal,  and  at  length  covers  it  over.  A  pinch 
of  charcoal  powder  is  then  added  in  tissue  paper, 
and  when  the  fusion  is  again  tranquil,  the  charge 
is  poured  into  a  mould,  and  the  slag  detached. 
The  load  is  cupelled,  and  the  assay  finished  as 
before. 

In  cupellation  some  gold  and  silver  is  carried 
into  the  cupel  with  the  litharge,  especially  if 
tellurium,  selenium,  copper,  &c.,  are  present. 
The  gold  and  silver  are  usually  recovered  bv 
fusmg  the  crushed  cupel  with  litharge,  charcoal, 
sodium  carbonate,  borax,  and  fluorspar,  and 
cupelling  the  button  of  lead  (see  Lodge's  Notes 
on  Assaying,  112-160). 

Assay  o/  gold  bvUum  and  ailoys,  A  piece  of 
the  metal  to  be  examined  is  adjusted  by  cuttine 
and  filing  to  correspond  in  weight  wi^  a  standard 
weight  marked  *  1000,'  ^diich  varies  with  differ- 
ent assayers  between  5  and  10  grains,  but  is 
usually  0*5  gram.  To  the  assay  piece  is  added  a 
piece  of  silver  (free  from  gold)  equal  in  weight  to 
2}  times  (at  the  Royal  Mint  2*1  times)  that  of 
the  cold  estimated  to  be  present  in  the  alloy, 
whicn,  if  not  already  known,  can  be  ascertained 
by  a  rough  preliminary  assay  or  by  the  touch- 
stone (see  p.  416)*  Tho  whole  is  wrapped  in 
sheet  lead,  the  weight  of  which  depends  mainly 
on  the  amount  of  copper  to  be  removed,  and 
varies  from  8  to  82  times  the  weight  of  metal 
taken  for  assay.  The  lead  packets  are  then 
transferred  by  means  of  tongs  to  cupels  already 
raised  to  a  bright  red  heat  in  the  muffle,  the 
current  of  air  through  the  muffle  is  carefully 
regulated  and  the  heat  maintained.  In  from 
10  to  20  minutes,  a  rapid  passage  of  brilliant 
iridescent  bands  of  oolour  over  the  surface  of 
the  button  is  observed  to  take  place,  and  the 
buttons  then  appear  to  become  colder,  no  longer 
glowing  brightly  with  the  oxidation  of  the  lead. 
A  few  minutes  later  the  muffle  is  closed  to  allow 
the  buttons  to  set  without  loss  by  spitting.  If 
copper  is  present  in  the  assay  pieces,  however, 
this  is  not  to  be  feared,  and  the  charse  can  be 
drawn  whUe  the  buttons  are  still  mcuten.  At 
the  Royal  Mint  a  charge  consists  of  72  assay 
pieces,  which  are  chargM  in  simultaneously  by 
means  of  a  divided  metal  tray  with  a  sliding 
bottom  and  withdrawn  simultaneously  while 
still  molten  by  means  of  a  tray  made  of  a 
mixture  of  graphite  and  clay,  on  which  the 
cupels  are  placea.  The  buttons  are  cleaned  by 
brushing,  flattened  on  an  anvil,  annealed  in  the 
muffle  or  before  a  blon-pipe,  and  reduced  to  a 
thickness  of  about  0-2  mm.  by  pa^ssage  through 
a  small  pair  of  flatting  roU«.    The  '  fiUets '  are 


416 


ASSATINa 


again  annealed  and  coiled  into  a  ipiTal  or  'comet ' 
by  the  finger  and  thimb. 

The  parting  in  nitric  acid  if  effected  either 
in  glass  parting  flasks  or  in  a  pjatinnm  boiling 
apparatus.  If  parting  flasks  are  nsed,  aa 
amount  of  about  2  oz.  of  nitric  acid  of  sp.gr.  1*2 
is  heated  in  the  fladc  almost  to  boiling,  and  the 
comet  is  then  dropped  in  and  boiled  until  2  or  3 
minutes  after  the  red  fumes  have  disappeared, 
llie  acid  is  then  poured  off,  and  the  gola,  after 
being  washed  twice  with  boiline  wat«r,  is  boiled 
for  a  further  16  minutes  wim  nitric  acid  of 
8p.gr.  1-2  or  stronger.  The  acid  must  be  free 
from  silver,  chlorine,  &o. 

The  gold  is  again  washed,  and  is  then  trans- 
ferred to  a  porous  crucible  or  *  annevline  cup ' 
by  filling  the  flask  with-  water,  placing  tne  cup 
over  its  mouth,  and  inverting  it.  The  gold  falLi 
into  the  cup,  and  the  flask  is  removed  without 
agitating  the  water  in  the  cup.  The  gold  is 
then  dried,  annealed  by  heating  to  redness,  and 
weighed.  If  no  more  than  thxee  parts  of  silver 
are  present  to  one  of  gold,  the  comet  does  not 
break  up;  and  if  enough  is  known  previously 
of  the  composition  of  the  bullion  to  make  sure 
of  this  in  the  cupelled  button,  a  platinum  tray, 
containing  a  number  of  little  platinum  cupe  may 
be  used.  A  comet  is  placed  in  each  cup,  and 
the  whole  tray  is  immersed  in  nitric  acid,  and 
subsequently  washed  by  dipping  in  and  out  of 
hot  water.  Less  acid  is  used  per  assay  piece 
by  this  method,  and  the  boilinjg  is  more  pro- 
longed, 30  minutes  in  each  of  two  acids  of  >p.gr. 
1-23  being  used  at  the  Royal  Mint. 

In  each  batch  of  assays,  two  or  more  check 
assays  on  pure  gold  are  made  to  determine  the 
*  surchar;^ '  or  net  sum  of  the  losses  of  gold  and 
the  gain  m  weight  due  to  the  retention  of  sflver. 
With  alloys  boiled  separately  in  fladcs,  check 
assays  are  of  comparatively  little  value  (see 
Rose's  MetallursT  of  Gold,  5th  ed.  470-498). 

AUoys  of  gM  and  Hlver  If  the  alloy  con- 
tains enough  silver  to  be  parted  by  nitric  acid, 
no  difficulty  arises.  Hie  silver  is  dissolved, 
precipitated  by  hydrochloric  acid,  and  weighed 
either  as  chloride  or  as  metal.  If  the  silver  is 
deficient  in  quantity,  the  alloy  is  mdted  with 
two  and  a  half  times  its  weight  ot  cadmium  under 
a  cover  of  potassium  cyanide  and  j^arted  witii 
nitric  acid.  The  silver  is  precipitated  and 
weighed  as  chloride,  or  determined  volumetri- 
cally  in  solution  by  means  of  sulphocvanide. 
Sometimes  the  silver  is  determined  bfv  <Unerence, 
the  alloys  beinff  cupelled  and  weighed,  and  subse- 
quently cupeUed  again  with  uie  addition  of 
silver,  and  parted. 

(For  alloys  containing  gM  atid  platinum,  »ee 
p.  418.) 

Assay  hy  the  touchsUme,  This  ancient 
method  consists  in  comparing  the  colour  of  the 
streak  produced  by  a  sample  of  gold  of  unknown 
composition  on  a  black  surface  with  those  from 
a  series  of  alloys  of  known  compositions,  after 
all  have  been  treated  alike  with  nitric  acid. 
Any  abrading  surface  on  which  the  add  is 
without  action  can  be  employed  for  this  purpose. 

Iridlam  occurs  alloyed  with  platinum,  and 
finds  its  way  into  gold  bullion.  In  the  latter 
case,  it  is  found  with  the  gold  comet  obtained 
in  the  bullion  assay,  adhering  in  the  form  of 
black  scales  or  powder  to  that  side  of  the  gold 
^jirhich  was  originally  nearest  to  the  cupel.    It 


can  be  estimated  by  dissolving  the  gold  in  ajua 
regia,  the  iridium  remaining  undissolved. 

Iron.  The  dry  assay  of  iron,  made  by 
fnsinff  ores  with  fluxes  in  caxboa-lined  (brasqued) 
craciolee,  is  obsolete,  and  need  not  be  described. 
The  wet  methods  are  volometrio,  based  on  the 
oxidation  of  iron  from  the  ferrous  to  the  ferric 
state  or  on  the  oonTerse  reduction.  Eitiier  the 
bichromate  or  the  permanganate  method  is 
g^enerall^  used  to  determine  the  total  amount 
of  iron  m  ores  or  the  amount  of  iron  present  in 
the  ferrous  condition.  The  stannous  chloride 
method  is  used  for  measuring  the  amount  of 
ironpiesent  in  the  ferric  state  in  an  ore. 

fx>r  the  determination  of  the  total  amount 
o(  iron,  the  ore  is  passed  through  an  SO-mesh 
sieve,  and  attacked  by  acids  as  usnaL  Moat 
ores  are  oxides,  carbonates,  ftc.,  and  the  iron  in 
them  is  easily  dissolved  by  hydrochloric  acid. 

Titaniferous  ores  are  fused  with  add  potas- 
num  sulphate  and  dissolved  in  water  and 
hydrochloric  add.  If  nitric  add  is  present  in 
the  acid  solution,  it  is  destroyed  by  evaporating 
to  dr3aiess  with  hydrochloric  add  and  taking 
up  with  hydrochloric  acid  and  water,  and  the 
iron  is  then  reduced  by  sine,  which  gives  a 
stream  of  hydrogen  or  (if  titanium  is  nresent)  by 
crystals  of  sodium  sulphite  in  a  neutralor  slightly 
acid  solution.  As  soon  as  the  solution  is  colour- 
less, the  exoess  of  zinc  is  removed,  or  the  sodium 
sulphite  decomposed  by  boiling  with  hydro- 
chloric acid,  and  titration  is  carried  out  in  a 
porcelain  baisin  by  means  of  a  solution  prepared 
by  weighing  out  4*39  grams  of  potassium  bichro- 
mate to  the  litre,  equivalent  to  6  grams  of  iron 
according  to  the  equation  : 
6FeajH-K,Cr,0,H-14Ha 

«:3Fe,a,-fCr,ag+2Ka+7H,0. 

Potassium  ferricyanide  (0*1  p.c.  solution, 
freshly  prepared)  is  used  as  an  indicator,  a  drop 
from  the  assay  solution  bein^  mixed  with  a  drop 
of  the  test  solution  on  a  white  glazed  tUe,  from 
I  time  to  time.  The  end-point  is  reached  when  a 
colour  is  no  longer  produced.  Tlie  solution  of 
bichromate  is  standardised  by  means  of  piano 
wire,  which  contains  about  0-4  p.a  of  impurities. 

The  permanganate  method  is  carried  out  in 
a  sulphuric  acid  solution,  the  equation  being : 

10FeSO4-fK,Mn,O,+8H,SO4 

-6Fe,(S()4),-f2MnS04+K,S04+8H,0. 

The  standard  solution  is  prepared  by  weighing 
out  2*82  grams  of  potassium  permanganate  per 
litre,  which  is  equivalent  to  5  grams  of  iron. 
The  end  reaction,  the  appearance  of  a  pinkish 
tinge  in  the  solution  in  the  flask,  is  very  sharp. 

When  the  amount  of  ferrous  iron  only  in  the 
ore  is  required,  the  ore  is  difssolved  in  hydro- 
chloric or  sulphuric  acid  with  exclusion  of  air. 
The  ferric  iron  may  be  determined  by  difference, 
or,  as  a  check,  the  stannous  chloride  method 
may  be  used,  in  which  the  yellow  solution  of 
ferric  iron  in  hydrochloric  acid  is  decolourised. 
The  standard  solution  (20  grams  of  commercial 
stannous  chloride  per  litre,  acidulated  with 
hydrochloric  acid)  is  run  into  a  boiling-hot 
solution  of  iron,  and  b  standardised  by  moans 
of  a  solution  of  ferric  chloride  free  from  nitric 
acid. 

Analysis  of  iron  and  sled.  The  elements 
requiring  estimation  are  carbon  (graphite,  com- 
bined carbon  and  total  carbon),  silicon,  man- 


ASSAYING. 


417 


ganese,  sulphur,  phosphonis,  arsenic,  and,  in  [ 
special  steels,  chromium,  nickel,  tungsten, 
molybdenum,  vanadium,  Ac  The  total  carbon 
is  estimated  by  combustion,  usually  after 
removal  of  the  iron  by  a  cupric  salt.  The 
graphite  is  estimated  by  combustion  of  the 
residue  after  dissolving  the  iron  in  hydrochloric 
add,  by  which  the  combined  carbon  ia  removed 
in  combination  with  the  hydrogen  evolved,  j 
or  more  advantageously  in  nitric  acid,  by  which 
the  combined  carbon  is  oxidised  and  retained  in 
solution.  The  combined  carbon  is  determined  by 
the  colour  of  a  nitric  acid  solution  compared  with 
the  colour  of  certain  standard  solutions  con- 
taining known  amounts  of  carbon.  Silicon  is 
weighed  as  silica  after  dissolution  of  the  iron 
by  acids  or  iodine.  Sulphur  is  weighed  aa 
barium  sulphate,  after  the  iron  has  been  dis- 
solved in  aqva  regia^  or  it  is  evolved  as  sul- 
phuretted hydrogen,  which  is  absorbed  by 
caustic  soda,  and  decomposed  by  a  standard 
solution  of  iodine.  'The  excess  of  iodine  is 
estimated  by  sodium  thiosulphate. 

Manganese  is  sepatated  bv  precipitation  with 
bromine  in  an  ammoniacal  solution  after  removal 
of  the  iron  as  basic  acetate.  The  precipitated 
bydrated  peroxide  is  heated  strongly  in  a  muffle 
and  weighed  as  Mn,04.  There  is  aJso  a  colori- 
metric  estimation,  the  steel  being  dissolved  in 
nitric  acid  axid  the  solution  boued  with  lead 
peroxide.  The  colour  of  the  permanganate 
produced  is  compared  with  those  of  standard 
solutions.  Phosphorus  is  precipitated  by  ammo- 
nium molybdate  or  magnesia  mixture.  Arsenic 
is  separated  by  precipitation  as  sulphide  in  an 
acid  solution,  converted  into  arsenic  acid  and 
determined  by  precipitation  by  magnesia  mixture. 

(7or  the  determination  of  the  metals  in 
special  steels,  «es  under  the  headings  Chromium, 
Nicid,  &c.  For  full  details  of  the  analyris  of 
iron  and  steel  andalso  of  the  complete  analysis 
of  iron  ores,  see  Blair's  Chemical  Analysis  of 
Iron,  Gampredon's  Guide  Pratique  du  Cnimiste 
M^lhixgiste  et  de  I'Essayeur,  438-634,  and 
Breariey  and  Ibbotson's  AnalyslB  of  Steel  Works 
llaterials.) 

Load.  Both  dry  and  wet  methods  of  assay 
are  used.  The  dry  assay  is  only  applicable  to 
rich  ores  and  to  con'^entrates,  and  even  with 
these  is  less  accurate  than  the  wet  methods. 
The  ore  is  crushed  through  a  60-mesh  sieve, 
mixed  with  sodium  carbonate  and  argol,  and 
fused  in  a  wrought-iron  crucible  or  in  a  clay  pot 
with  hoop-iron.  Galena  is  reduced  by  the  iron, 
and  any  oxides,  sulphates,  &c.,  of  lead  are 
reduced  by  the  ugpl*  Borax  is  sometimes 
added  as  a  cover.  ^Aie  following  are  examples 
of  the  charges  recommended  by  Percy : — 

2.  Any 
1.  Blch  galena,  esp.  8.  Phos-   4.  Cenis- 
galena   poor  ores   phate  ore     site 
Ore      •         .  SOOgrs.  600  grs.  300  grs.  500  grs. 
Sodium    car- 
bonate      .  600  „     350  „     350  „     500  „ 


Argol  (Urtar)    60  „      100  „      100 
Borax  .         .     —         150  „       30 


>f 


M 


100  „ 
30  „ 


The  iron  crucible  is  made  red  hot,  cleaned,  and 
allowed  to  oooL  The  charge  is  then  transferred 
to  it,  care  being  taken  to  avoid  loss  by  dusting, 
and  the  borax,  or,  if  none  is  used,  part  of  the 
aodium  carbonate  is  added  as  a  cover.  A  day 
lid  is  also  placed  on  the  crucible.    The  charge 

Vol.  I.— T. 


is  slowly  heated  for  about  20  minutes,  and  ia 
then  ]xiured  into  a  mould,  provided  that  all 
siens  of  offorvescencQ  have  disappeared,  and  the 
mixture  is  seen  to  be  in  a  state  of  tranquil 
fusion.  The  lead  is  found  at  the  bottom.  It 
is  detached  from  the  slag  with  a  hammer,  and  ia 
cleaned  and  weighed.  The  slag  is  examined  for 
lead  beads  before  being  thrown  away.  Clay 
crucibles. are  used  for  phosphate  and  carbonate 
ores. 

When  the  ore  contains  arsenic,  a  speise  is 
formed  which  is  found  adhering  to  the  upper 
surface  of  the  lead,  below  the  slag.  It  must 
be  removed  with  great  care  to  avoid  loss  of  lead. 
The  lead  should  be  soft  and  malleable.  The 
silver  and  gold  in  the  ore  arc  determined  by 
oupellation  and  parting  {see  p.  415).  The 
method  gives  results  with  pure  ores  wmch  are 
about  1  or  2  p.c.  too  low.  When  the  ore 
contains  antimony,  bismuth,  copper,  &c,  these 
metals  are  in  part  reduced  with  the  lead,  and 
are  weighed  with  it.  If  the  lead  button  is 
hard,  it  is  necessary  to  estimate  the  lead  in  it 
by  weighing  it  as  lead  sulphate  or  otherwise,  or 
to  adopt  wet  methods  of  assaying  the  ore. 

(For  detaib  of  the  dry  assay  of  lead,  see 
Percy's  Metallurgy  of  Lead,  103-119.) 

In  the  wet  methods,  oxidised  ores  are 
attacked  by  hydrochloric  acid,  followed  by 
nitric  acid,  if  necessary.  Sulphide  ores  are 
treated  direct  with  nitric  aoiol  The  lead  is 
determined  either  as  sulphate  or  volumetrically, 
by  means  of  ammonium  molvbdate  (Alexander's 
method).  In  the  latter  mewod  (Eng.  and  Mne. 
J.  April  1,  1893,  298),  the  mixture  of  nitric 
acid  and  ore  is  evaporated  with  sulphuric  acid, 
diluted,  boiled,  and  filtered.  The  lead  sulphate 
in  the  residue  is  dissolved  in  hot  ammonium 
acetate,  acidified  with  acetic  acid,  raised  to 
boiling,  and  titrated  with  a  standard  solution  of 
ammonium  molybdate,  containing,  according  to 
Low,  4*26  grams  per  litre.  The  solution  is 
standardised  w^ith  pure  lead  foil.  Tannin  is 
used  as  an  indicator,  giving  a  yellow  colour  to 
a  drop  of  the  solution  on  a  white  placed  tile 
when  the  ammoiuum  molybdate  is  in  excess. 
If  iron  and  calcium  are  present,  it  is  better  to 
separate  the  lead  as  sulphide  and  redissolve 
before  titration  (Low's  Ore  Analysis,  113). 

Lead  may  also  be  determined  in  a  feebly 
acid  solution  by  adding  an  excess  of  potassium 
chromate  and  estimating  the  amount  of  excess 
by  means  of  a  standud  solution  of  ferrous 
chloride.  The  reaction  is  the  same  as  in  the 
bichromate  assay  of  iron,  but  in  this  case  the 
end  is  marked  by  the  appearance  of  a  green 
colour  in  the  test  drops  on  the  plate  (Beringer'i 
Assaying,  214). 

Manganese  occurs  as  MnO^  in  pvrolusite. 
Spiegcleisen,  ferromanganese,  and  steel  are  also 
assayed  for  mansanese.  Either  the  ferrous 
sulpnate  assay  or  Volhard*s  volumetric  process 
is  generally  used.  In  the  latter  method  the 
manganese  is  precipitated  by  potassium  per- 
manganate in  a  boiling  neut^l  solution.  The 
precipitate,  as  far  as  numbers  are  concerned,  is 
represented  by  the  equation : 

K.Mn,0,+3MnS04+2H,0 

=K,S04+6MnO,+2H^04 

About  one  gram  of  the  ore  or  spiegcleisen 
is  dissolved  in  hydroohlorio  and  nitric  acids, 

2  K 


4id 


ASSAYING. 


heated  with  tolphurio  aoid,  and  neutralised  by 
the  addition  ot  an  emulsion  of  zinc  oxide  in 
slight  excess.  AU  the  iron  is  precipitated,  and, 
after  violently  shaking  the  mixture,  it  is  made 
up  to  500  0.0. ,  allowed  to  settle,  and  100  c.c.  of 
the  clear  supernatant  liquid  is  drawn  off,  heated 
to  boiling,  and  titrated.  The  end  point  is 
marked  by  the  appearance  of  a  pinkish  tinge. 
(For  the  estimation  of  manganese  in  steel,  see 

P  417.) 

Mereniy.  The  wet  methods  of  assay  ars  not 
satisfactory,  and  one  of  the  distillation  methods 
is  usually  employed.  When  a  laise  percentage 
of  mercuiT  Is  present,  a  combustion  tube  of 
18-20  inches  long  is  used.  It  is  sealed  at  one 
end  and  magnesite  powder  plaoed  in  it  first,  to 
a  depth  of  3  or  4  inches.  Next  a  layer  of  2 
inches  of  unslaked  lime  is  added  and  then  6  or  10 
grams  of  ore  well  mixed  in  a  mortar  with  10  grams 
of  lime.  The  mortar  is  cleaned  with  more  lime 
and  the  rinsings  added  to  the  tube  and  coyered 
with  clean  Ume  to  a  depth  of  3  or  4  inches. 
Finally,  a  loosely  fitting  plug  of  asbestos  is 
inserted  and  the  unoccupied  portion  of  the  tube 
is  drawn  out  almost  to  a  point  and  bent  over 
at  right  angles,  care  bein^  taken  that  no  hollow 
in  the  glass  is  formed  which  might  collect  some 
of  the  mercurv.  The  tube  is  placed  in  position 
in  a  combustion  furnace  and  tapped  until  the 
mixture  settles  and  leaves  a  free  passage  for 
eases  throughout  its  length.  The  narrow  open- 
ing is  made  to  dip  into  a  beaker  of  water,  and 
the  tube  is  heated,  beginning  with  the  ssbestos 
plug  and  finishing  with  the  magnesite,  which 
yields  enough  carbon  dioxide  to  sweep  out  the 
vapours  of  mercury.  The  time  required  for 
heating  is  about  30  minutes.  While  the  tube 
is  still  red  hot  throughout  its  length,  its  end  is 
out  off  and  dropped  into  the  oeaker.  Hie 
mercury  collects  m  the  water,  and  is  dried  b^ 
blotting-paper  and  then  in  a  desiccator  an 
weighed  m  a  porcelain  crucible. 

When  only  small  quantities  of  mercury  are 

S resent,  Eschka's  method  is  used  (DingL  poly. 
.  cciv.  74),  in  which  the  mercury  is  condensed 
on  a  weighed  pieoe  of  gold.  This  is  in  the 
form  of  a  basm  made  of  thin  sheet  gold, 
used  as  the  cover  of  a  porcelain  crucible  and 
filled  with  water  to  keep  it  cool.  The  basin 
projects  beyond  the  rim  of  the  crucible,  and 
usually  weighs  about  10  grams.  FVom  0'2  to  2*0 
grams  of  ore  is  mixed  with  1-4  grams  of  iron 
filings,  and  heated  in  the  crucible  for  10  or  20 
minutes,  the  flame  being  kept  from  heating  the 
upper  part.  This  may  be  done  by  fitting  the 
crucible  into  a  hole  in  a  pieoe  of  sheet  asbestos. 
The  gold  basin  is  then  dried  without  the  agency 
of  heat,  and  weighed,  the  increase  of  weight 
representing  the  mercury. 

Molybdeniim  in  ores  is  estimated  by  pre- 
oipitation  as  mercurous  molybdate  in  a  very 
slightly  alkaline  or  neutral  solution  by  means  of 
mercurous  nitrate.  The  precipitate  is  ignited 
in  a  porcelain  crucible,  either  alone  or  with 
litharge,  until  the  mercury  is  expelled.  The 
increase  in  the  weight  of  the  oruoiUe  is  taken 
as  MoO„  but  if  chromium,  vanadium,  tungsten, 
phosphorus,  or  arsenic  is  present  in  the  ore,  the 
Ignited  MoOg  must  be  purified  by  further  treat- 
ment or  separated  before  precipitation.  Moly- 
bdenum in  steel  is  precipitated  as  ammonium 
phospho-molybdate. 


Nickel  and  cobalt  occur  together  in  ore%  tlie 
former  more  commonly  and  in  greater  proportion 
than  the  latter.  They  are  usually  assayed 
together.  In  the  fire  assay,  the  ore  is  roasted 
sweet  and  then  fused  with  arsenic  to  form  a 
speise.  This  is  heated  in  air  on  a  little  clay  dish 
in  the  muffle,  and  the  metals  oxidised  succes- 
sively, iron  passing  into  the  slag  first,  cobalt 
next,  and  then  nickel,  copper  being  left  until 
last.  The  changes  in  oolour  of  the  borax  slag 
show  the  progress  of  the  assay.  The  slag  is 
coloured  brown  while  iron  is  passing  into  it,  blue 
by  cobalt^  dierry-brown  by  nickel,  and  blue  by 
copper.  Gold  is  added  to  the  speise  after  the 
elimination  of  cobalt  if  copper  is  present.  The 
speise  is  weighed  after  each  metal  has  been 
removed.  The  slag  must  be  frequently  ex* 
amined  and  renewed,  and  great  oare  and  ex- 
perience are  needed  ta  attain  even  approximate 
results. 

The  method  is  easier  to  carry  out  if  copper 
is  absent,  and  this  metal  is  sometimes  removed 
by  precipitation  with  sulphuretted  hydrogen  in 
an  acid  solution  before  the  spelae  is  formed.  If 
cobalt  is  absent,  a  weighed  amount  may  be  added, 
as  otiierwise  it  is  difficult  to  observe  the  point  at 
which  nickel  begins  to  pass  into  the  slag  after  the 
removal  of  the  iron.  The  arsenides  in  the 
speise  have  the  formula  FcgAs,  CotAs,  Ni^Asy 
and  CujAs  (Bhead  &  Sexton*s  Assaying,  187). 

In  the  wet  methods  it  is  usual  to  roast  the 
ore  as  a  preliminary  in  order  to  remove  the 
aisenic,  sulphur,  &o.,  and  then  to  separato 
the  nickel  and  cobalt  horn  the  iron,  manganese, 
zinc,  &c.,  by  suitable  methods.  The  nickel  is 
precipitated  as  hydrate  and  weighed  as  NiO. 
Cobalt  is  often  included  in  the  nickel,  but  is 
separated  if  present  in  large  quantities.  A 
volumetric  method  depends  on  the  interference 
by  nickel  in  the  titration  of  cyanide  with  a 
standard  solution  of  rilver  nitrate.  An  alkaline 
solution  containing  caustic  soda  is  used,  and  a 
littie  potassium  iodide  added  as  an  indicator. 
An  excess  of  a  standard  solution  of  potassium 
cyanide  is  added  to  a  solution  of  nickel  sulphate 
made  alkaline  (and  precipitated)  by  caustio 
soda.  The  excess  of  cyamde  is  titrated  by  a 
standard  solution  of  suver  nitrate  (Beringer's 
Assavingp  255).  The  reactions  are  represented 
by  the  equations : 

4KCy+NiS04-K,NiOy4+K,804. 
2KCy-fAgN0,=KAgpy,+KN0r 

Nickel  and  cobalt  are  also  sometimes  esti- 
mated by  electrolysis,  and  for  this  purpose  must 
be  separated  from  Eino  and  other  metals,  dis- 
solvea  in  nitric  acid,  and  precipitated  in  an 
ammoniacal  solution. 

Nickel  is  separated  horn  cobalt  by  precipi- 
tation with  dimethylglyoxime,  and  may  oe 
estimated  in  that  way.    {See  Akai<tsi8.) 

Nickel  in  steel  is  precipitated  by  bromine 
water  and  caustic  soda,  after  removal  of  the 
iron  as  basic  acetate.    It  is  weighed  as  NiO. 

Platinum  in  alluvial  deposits  is  concentrated 
by  panning,  as  in  the  case  of  auriferous  sands« 
In  all  cases  platinum  can  be  coUeoted  in  lead 
by  the  same  methods  as  those  deeoribed  under 
the  assay  of  gold  ores.  The  lead  buttons  are 
sometimes  cupelled  at  a  very  high  temperature, 
but  it  is  difficult  to  remove  the  whole  of  the  lead 
in  this  way,  as  the  '  prill  *  freeses  on  the  ciypel 


ASSAYING. 


419 


when  oiily  part  of  the  lead  has  been  oxidised,  > 
uniesj  a  weighed  amount  of  gold  or  silver  is 
added  in  older  to  produce  an  alloy  of  lower 
melting  noint  than  pure  platinum. 

CopeUation  may  he  finished  in  the  oxygen-gas 
blowpipe  flame,  but  the  loss  of  platinum  is  then 
large.  It  is  more  usual  to  dissolve  the  lead 
button  in  dilute  nitrio  aoid  and  to  filter  of!  the 
platinum  and  gold  residue,  which  is  parted  by 
dissolving  in  aqua  rfffia,  and  precipitating  the 
ffold  with  oxalic  acid.  The  platmum  is  estimated 
by  difference  or  by  precipitation  as  (NHJ.PtCl,. 

Platinum  in  alloys  or  in  rich  alluvial  con- 
centrates may  be  estimated  by  melting  with 
six  parts  of  puze  lead,  and  grinding  in  a  mortar 
the  brittle  alloy  freed  from  slag.  Portions  of 
the  alloy  are  scorified  with  fresh  lead  and 
dissolved  in  nitrio  acid. 

Alloys  eontaining  gold,  silver,  and  platinum 
are  difficult  to  assay,  as  they  are  insoluble  in 
aqua  regia.  The  method  adopted  is  first  to 
cupel  the  alloy  to  remove  copper,  ko,,  these 
metals  bein^  estimated  by  difference.  The 
alloy  is  then  inquarted  by  cupellation  with  twice 
its  weight  of  silver  and  parted  by  boiling  in 
sulphuric  acid.  The  residue  contains  the  gold 
ana  platinum.  These  may  be  parted  by  a^ain 
inquarting  with  silver  and  dissolving  in  nitrio 
acid,  provided  that  the  amount  of  g^d  present 
is  at  least  ten  times  that  of  the  pUtinum.  If 
the  proportion  of  gold  present  is  less  than  this, 
part  of  the  platinum  remains  undissolved,  and 
It  is  therefore  necessary  to  add  sold  in  many 
cases.    The  parted  gold  is  weighed  and  the 

SUtinum  estimated  by  difference  (6*»*  Rapport 
es  Monnaies,  1901,  p.  xxix. ;  Rose's  Precious 
Metals,  272). 

Snver.  The  ores  of  silver  are  assayed  in  the 
same  way  as  those  of  cold  of  a  similar  kind, 
the  soorification  method  beins  used  far  more 
frequently  than  in  the  case  of  ^old  ores.  The 
sla^  and  oupds  must  be  exammed  usually,  as 
silver  is  more  readily  lost  than  gold.  The  tem- 
perature of  cupeUation  is  kept  as  low  as  iK)ssible, 
to  check  the  loss  of  silver  by  volatilisation  (see 
Lodge's  Notes  on  Assaying,  37-111). 

Silver  bullion  and  alloys  are  assayed  by 
cupellation,  by  the  Gay  Lussao  or  the  Volhard 
volumetric  processes,  or  by  weighing  the  chloride 
(India  Mint  method).  In  cupellation,  the 
*  base '  or  oxidisable  metals  are  removed  in  the 
muffle,  and  the  silver  prill  is  cleaned  and  weighed. 
The  weight  of  silver  taken  is  usually  10  grains. 
The  amount  of  lead  required  varies  from  six 
times  the  weight  of  the  silver  for  alloys  of  high 
standard  to  twelve  times  for  silver  700  fine. 
The  method  is  not  suitable  for  alloys  containing 
less  than  70  p.o.  of  silvei^  The  muffle  is  kept 
at  a  lower  temperature  than  that  required  for 
gold  cupellation,  but  must  be  raised  to  above  the 
melting-point  of  pure  silver  (962*)  at  the  finish, 
to  prevent  the  metal  from  setting  in  the  furnace 
before  all  the  lead  has  been  removed.  When 
the  oupeUation  is  complete,  the  mouth  of  the 
furnace  is  dosed  with  great  care  to  exclude 
draughts,  and  the  furnace  is  allowed  to  cool 
slowfy  to  prevent  loss  of  silver  by  spittine.  The 
solidified  priUs  are  cleaned  and^  weighed.  The 
loss  of  silver  in  cupellation  varies  from  6  to  15 
parts  per  1000,  and  check  assays  on  pure  silver 
are  placed  in  all  parts  of  the  furnace  to  measure 
this  loss.    Any  gold  that  may  be  present  is 


weighed  as  silver.  The  prooen  is  Twy  ancient, 
and  clear  reference  is  made  to  it  in  connection 
with  a  trial  of  the  Pyx  in  the  Black  Book  of  the 
I^chequer,  written  in  the  reign  of  Henry  IL 

In  the  Gay  Lussao  process,  the  volume  is 
measured  of  a  standard  solution  of  common 
salt  or  sodium  bromide  required  for  the  pre- 
cipitatior  of  a  little  more  than  a  gram  of  silver 
in  solution  as  nitrate.  No  iodicator  is  used,  and 
the  end  of  the  operation  is  judged  from  the 
appearance  of  a  faint  cloud  of  chloride  in  a 
solution  from  which  almost  all  the  silver  has 
been  precipitated.  It  is  the  most  accurate 
method  of  assaying  silver  bullion.  The  standard 
solution  of  common  salt  (usually  called  the 
*  normal  solution  ')  contains  about  6*416  grams 
of  NaCl  per  litre,  so  that  100  c.c.  will  precipitate 
1  gram  of  silver.  A  weight  of  silver  bullion  con- 
taining^ about  1-003  gram  of  silver  is  weighed 
and  dissolved  in  nitric  acid,  and  100  cc.  of  the 
salt  solution  added  to  it  from  a  pipette.  The 
chloride  is  agglomerated  by  a  shaking  in  a 
stoppered  bottle,  and  the  clear  supernatant 
liquid  is  tested  by  *decinormal'  solutions  of 
common  salt  and,  if  neoessary,  of  silver 
nitrate.  The  appearance  of  the  cloud  of  silver 
chloride  shows  the  amount  of  silver  left  in  so- 
lution. Further  shakings  are  resorted  to  if 
required,  and  the  final  reading  is  taken  after 
waiting  for  about  6  or  10  minutes.  Check 
assays  on  fine  silver  are  used  with  every  batch 
to  test  the  strength  of  the  solution,  which  varies 
with  the  temperature,  A^c.  Mercury  interferes 
with  the  method,  and  is  detected  by  the  colour 
of  the  precipitated  silver  chloride,  which  doe^ 
not  darlcen  if  mercury  is  present.  Acetate  of 
soda  corrects  the  error  if  the  quantity  of  mercury 

rjent  iB  smalL  The  Gay  Lussac  method  can 
used  only  in  oases  where  the  approximate 
assay  is  already  known  (Percy's  Silver  and  Gold« 
282;  Riche  et  Fore«t,L'Art  de  I'Essayeur,  183). 

In  the  India  Mint  method,  the  sUver  alloy 
is  dissolved  in  nitrio  aoid  and  precipitated  by 
a  slight  excess  of  hydroohlorio  acid.  The  silver 
chloride  is  then  collected  by  shaking  in  a  stop- 
pered bottle,  and,  after  bemg  washed,  ii  trans- 
ferred to  a  porous  cup,  dried,  and  weighed  while 
warm.  The  ohloride  is  washed  by  dMantation, 
but  the  dryins  is  tedious,  and  is  expedited  by 
breaking  up  we  crust  with  a  glass  rod.  Any 
gold  that  may  be  present  is  weighed  as  silver 
chloride.  This  is  the  best  method  for  alloys  con- 
taining less  than  70  p.o.  of  silvev  (Trans.  Instb 
Mn£.  *  Met.  xviL  334). 

The  Volhard  method  is  largely  used  in  this 
country.  The  nitrio  acid  solution  of  the  silver 
is  freed  from  nitrous  aoid  by  boilings  and  is  then 
diluted  and  titrated  with  a  solution  oontaining 
7*04  grains  of  ammonium  thiocyanate  per  litre. 
As  tms  salt  is  deliquescent,  it  is  usual  to  weigh 
out  about  7*3  grains  per  litres  Iron  alum  ii 
used  as  an  indicator,  giving  a  red  colour  when 
all  the  silver  has  been  precipitated.  Time  is 
saved  and  the  aoouraoy  of  the  method  increased 
by  taking  for  assay  an  amount  of  aUoy  oontain- 
ing about  1*003  gram  of  silver,  and  running  in 
1(%  cc.  of  the  standard  solution  of  thioo^aoate 
from  a  pipette.  After  shaking  the  liquid  in  a 
flask,  the  titration  is  finished  by  adding  the 
thiocyanate  a  drop  or  two  at  a  time.  Check 
assays  on  line  silver  are  used  (Trans.  Inst.  Mng, 
&  Met.  xvi.  154). 


420 


ASSAYiNG* 


Tin.  Tin  ore  is  concentrated  on  a  vanning 
shovel  with  the  production  o£  *  black  tin  *  in 
order  to  determine  what  yield  may  be  expected 
when  the  ore  is  treated  on  the  (uessing  floors. 
The  ore  is  crushed  and  sampled,  and  about 
30  grams  (or  less  with  rich  ores)  are  thoroughly 
mixed  with  30  or  40  c.c.  of  water  on  the  vanning 
shovel,  to  prevent,  as  far  as  possible,  the  loss  of 
*  float  tin.  The  ore  is  then  collected  by  a 
v^^orous  circular  motion  of  the  water,  and  the 
swnes  are  poured  ofiF,  a  process  which  is  repeated 
until  the  water  remains  clear  after  being  left 
to  settle  for  a  few  seconds.  A  smaller  quantity 
of  water  is  used  for  the  subsequent  operations. 
By  means  of  a  circular  motion  of  the  shovel, 
combined  with  a  series  of  jerks,  the  tin  oxide  is 
now  separated  from  the  lighter  material*  which 
is  carried  down  by  the  descending  wave.  The 
tailings  are  sometintes  saved  and  washed  over 
again  until  thev  yield  no  more  tin,  and  are  then 
crushed  by  rubbmg  with  a  hammer  and  again 
washed.  The  concentrates  are  dried  and 
roasted  and  dressed  once  more  after  being  rubbed 
down  with  a  hammer.  Sometimes  they  are 
washed  quite  clean  from  worthless  material, 
and  sometimes  left  impure  with  oxide  of  iron, 
&c.,  according  tc  the  nature  of  the  ore  and  the 
custom  of  the  opeAtor.  Sometimes  they  are 
purified  by  boiling  in  hydrochloric  add  or  aqua 
regia,  which,  aocordins  to  J.  H.  Collins,  causes  a 
loss  of  tin.  The  residue  is  usually  reported  in 
pounds  of  block  tin  to  the  long  ton  of  ore. 
The  losses  of  oassiterite  in  vanning  vary  con- 
siderably, and  may  be  reckoned  as  30  to  40  p.c. 

The  black  tin  obtained  by  vanning  may  be 
assayed  for  metallic  tin  by  reduction  with 
anthracite  (Cormsh  method)  or  by  fusion  with 
potassium  cyanide.  In  the  Oomish  method 
100  grams  of  tinstone  are  heated  with  20  grams 
of  anthracite  in  a  plumbago  crucible  at  a  white 
heat  for  15  or  20  minutes  before  pouring.  The 
excess  of  anthracite  contains  beads  of  tin,  which 
are  separated  by  sieving  and  vanning.  In  the 
cyanide  process,  10  grams  of  tinstone  are  fused 
with  40  grams  of  impure  cyanide  (containing 
potassium  carbonate),  and  poured  at  a  red  heat. 
The  Qerman  process  consists  in  reducing  a 
mixture  of  5  grams  each  of  tinstone  and  cuprio 
oxide  with  16  grams  of  black  flux  (a  mixture  of 
carbon  mad  potassium  carbonate,  obtained  by 
heating  tartar)  and  1*26  grams  of  borax  with  a 
cover  of  common  salt.  The  reduced  metal  is 
compared  in  weight  with  tJiat  of  the  copper 
reduced  from  <^prio  oxide  alone.  The  most 
trustworthy  of  these  methods  is  the  fusion  with 
cyanide.  The  reduced  tin,  however  obtained, 
is  usually  impure  (Beringer's  Assaying  and  Kerl's 
Metallurgische  Probirkunst). 

Tin  is  also  estimated  volumetrically.  A 
satisfactonr  method  described  by  Beringer 
(Text-Book  of  Assaying,  11th  ed.  285)  iB  to 
reduce  the  solution  of  stannic  chloride  to  stan- 
nous chloride  by  means  of  nickel  foil,  and  to 
titrate  with  a  standard  solution  of  iodine  in  an 
atmosphere  of  carbonic  acid  gas.  Starch  is 
used  as  an  indicator.  In  all  wet  methods,  tin 
oxide  must  be  reduced  to  metallic  tin  before  it 
can  be  dissolved.  Beringer  prefers  reduction 
by  means  of  zinc  vapour  acting  on  ore  mixed 
with  oxide  of  sine.  The  alloy  of  zinc  and  tin 
thus  produced  is  dissolved  in  hydrochloric  acid, 
to  which  crystals  of  permanganate  are  added. 


In  Pearce*8  method  (Low*s  Technical  Analysis. 
261)  the  ore  is  fused  with  caustic  soda  and 
charcoal  powder,  and  the  mass  dissolved  in 
hydrochloric  acid ;  the  reduction  of  the  stannic 
to  stannous  chloride  is  then  effected  with  iron 
rods. 

Titanium  in  ores  is  generally  in  the  form  of 
titanic  oxide,  which  is  insoluble  in  acids.  Tita- 
nates,  however,  are  somewhat  soluble,  so  that 
on  attacking  ores  with  acid,  titanium  will  be 
found  parthr  in  the  residue  and  partly  in  the 
solution.  The  metals  of  the  iron  group  with 
titanium  are  precipitated  from  the  solution  as 
basic  acetates,  which  are  fused  with  potassium 
bisulphate  and  extracted  with  water.  The 
titanic  acid  is  precipitated  from  the  solution 
by  means  of  prolonged  boiling  with  sulphurous 
acid.  The  rasidue  left  by  the  attack  on  the 
original  ore  with  acids  is  similarly  treated,  after 
the  silica  has  been  removed  by  heating  with 
sulphuric    and   hydrofluoric   acids    (Beringer*8 

Assuring*  293). 

Tangsten  in  wolfram,  steel,  &c.,  is  estimated 
by  weighing  as  tungstic  acid  WO,.  The  ore  is 
boiled  with  hydrochlorio  acid  followed  by  aqua 
regia,  when  the  tungsten  separates  as  insoluble 
yellow  tungstie  acid.  After  thorough  washing, 
this  is  dissolved  in  ammonia,  filtered,  and  re- 
covered by  evaporating  the  solution  to  dryness, 
and  gently  igniting  the  residue  to  decompose  the 
ammonium  tungstate.  Nearly  pure  tungstie 
acid  remains.  Any  silica  that  may  be  present 
may  be  removed  by  hydrofluoric  acioL  The 
tungstie  acid  may  also  be  precipitated  from 
solution  by  neutralising  with  nitric  acid  and 
adding  a  solution  of  mercurous  nitrate 
(Beringer's  Assaying,  13th  ed.  p.  297  d.).  In 
attackmg  ores  with  acid,  some  wO,  is  dissolved 
in  the  presence  of  fluorides,  arsenic  or  phosphorus* 
but  this  is  corrected  by  the.  addition  of  cin- 
chonxne.  The  ores  may  be  attacked  by  fusion 
with  caustic  noda  and  sodium  peroxide,  or  by 
digesting  with  soda  solution  instead  of  by 
boiling  with  acid  (Hutchin  and  Tonks,  J.  Inst. 
Mng.  and  Met.  18,  1909,  425). 

Uranium.  The  mineral  is  evaporated  with 
nitric  acid  and  taken  up  with  HCL  After 
separation  of  the  other  metals  as  sulphides  and 
carbonates,  the  uranium  is  precipitated  by 
ammonia  and  weighed  as  Vfig,  or  it  is  pre- 
cipitated by  microoosmic  salt  in  the  presence 
01  acetic  acid  and  ammonium  acetate.  The 
precipitate  consists  of  ammonium  uranyl 
phosphate  U0aNH4P0^  which  is  washed, 
ignited  gently  luid  weighed  or  converted  into 
uranyl  pyrophosphate  {VO^)JPfiy,  for  greater 
accuracy  (Low*s  Technical  Ore  Analysis,  201). 
This  precipitation  ia  also  the  basis  of  a  volu- 
metric method,  a  boiling  solution  of  uranium 
being  titrated  with  a  standard  solution  of 
phosphate,  until  ferrooyanide  no  longer  gives  a 
brown  colour. 

Vanadium  in  steel  is  estimated  by  titrating 
with  potassium  permanganate.  '  The  steel  is 
dissolved  in  HCl  and  evaporated  to  dirness  with 
a  little  nitric  acid.  The  residue  is  fused  with 
nitre  and  fusion  mixture,  boiled  in  water  and 
flltered,  and  the  filtrate  evaporated  with  H^04, 
reduced  by  sulphur  dioxide  and  titrated.  One 
atom  of  iron  is  equivalent  to  one  of  vanadium 
in  the  titration  (Rhead  and  Sexton's  Assaying, 
270). 


ASSAYING. 


421 


Sno.  The  old  dry  method  of  Maa.y  of  ores 
baaed  on  the  loss  of  weight  due  to  the  volatilisa- 
tion of  zino  at  a  white  heat  is  obsolete.  Certain 
alloys  of  zinc  with  tin  and  copper,  e.g.  coinage 
bronze,  are  assayed  for  zinc  by  heating  to 
1200^  for  two  honzB  in  carbon  crucibles  (J.  Soc. 
Ghem.  Ind.  33,  1914,  270).  The  loss  of  weight 
gives  the  zinc  tofl^ther  with  any  cadmium  or 
oxygen  present.  Check  assays  on  trial  plates  of 
known  composition  are  necessary  Zinc  is 
usually  weighed  as  oxide  after  precipitation  as 
carbonate,  or  it  is  titrated  with  sodium  sulphide 
or  potassium  ferrocyanide.  An  amount  of 
1  or  2  grams  of  ore  is  weighed  out  and  dissolved 
m  hy<uochloric  acid  or  aqua  regta.  The  silica 
and  metals  other  than  zinc  are  removed  as  usual. 
All  the  precipitates  will  contain  zinc  if  they  are 
bulky,  and  must  be  redissolved  and  reprecipi- 
tated.  The  alkaline  filtrate  may  be  diluted  to 
200  c.c.  and  used  for  the  sodium  sulphide  ti- 
tration, Tduch  is  carried  out  at  GO^-W.  A  flake 
or  two  of  freshly  precipitated  ferric  hydrate  is 
used  as  an  indicator,  turning  from  red  to  black 
as  soon  as  sodium  sulphide  is  in  excess.  One  c.c. 
of  the  standard  solution  of  sodium  sulphide 
should  be  equal  to  OOl  gram  zinc.  Instead  of 
ferric  hydrate,  sodium  nitroprusside.  may  be 
used  as  an  indicator  on  a  white  tile.  This  gives 
a  purple  colour  with  sodium  sulphide. 

For  titration  with  potassium  ferrocyanide, 
the  pure  ammoniacal  solution  of  zinc  obtained 
as  above  is  acidified  with  hydrochloric  acid, 
boiled  and  titrated  hot.  The  standard  solution 
of  ferrocyanide  is  made  up  by  dissolving  41*25 
grams  of  the  pine  salt  in  a  li&e  of  water.  The 
test  solution  oonsiste  of  0*5  nam  of  uranium 
acetate  dissolved  in  20  o.c.  of  water.  A  drop 
of  tiiis  solution  gives  a  brown  colour  on  a  white 
tile  with  a  drop  of  the  zinc  solution  as  soon  as 
the  ferrocyanide  is  in  excess.  It  is  advisable 
to  confirm  the  end  reaction  bv  adding  5  c.c.  of 
a  standard  solution  of  zinc  in  hydrocmoric  acid, 
containing  10  grams  of  zinc  per  litre,  and  again 
titrating  (Chem.  News,  Ixxvi.  6). 

The  assay  of  zinc-dust  for  metallic  zino  is 
made  by  acting  on  the  sample  with  dilute  sul- 
phuric acid,  and  coUeoting  and  measuring  the 
hydrogen  which  is  evolved. 

Commercial  metallic  zinc  contains  lead, 
cadmium,  and  iron,  and  may  also  contain 
arsenic,  copper,  antimony,  tin,  &c  By  dis- 
solving in  cUlute  sulphuric  acid,  the  lead  and  the 
greater  part  of  the  copper,  tin,  cadmium,  ftc, 
are  left  undissolved.  The  residue  is  attacked 
with  nitric  acid,  and  the  metals  separated  as 
osuaL  Iron  in  zino  is  titrated  in  the  sulphuric 
acid  solution  without  being  separated.  Arsenic 
and  antimony  are  |waBed  with  the  hydrogen 
evolved  by  sulphuric  acid  into  a  solution  of 
silver  nitrate  (Campredon.  Guide  Pratique,  700 ; 
Eliot  and  Storer,  Amer.  Acad.  Arte  &  Sciences, 
viii.  67). 

Goal.  The  assay  of  coal  usually  comprises 
the  determination  of  moisture,  total  ash,  sulphur, 
coking  properties,  and  calorific  power.  The 
coal  is  raoken  down  and  sampled  as  in  the  case 
of  ores  (see  p.  406),  and  the  sample  is  passed 
Uirough  an  SO-mesh  sieve. 

The  moisture  is  determined  by  drying  1 
gram  in  a  water-oven  for  30  minutes  and  weigh- 
m^.  The  coal  is  then  again  wanned  for  15 
nunutes  and  reweighed,  and  the  process  is  con- 


tinned  until  the  weight  is  constant  or  b^ins  to 
increase.  • 

For  sulphur,  2  grams  of  coal  are  mixed 
with  3  grams  of  a  mixture  of  two  parte  of 
calcined  ms^esiaand  one  part  of  potassium  car- 
bonate, ana  heated  to  dull  redness  for  an  hour 
in  a  porcelain  or  platinum  crucible,  with  occa- 
sional stirring.  After  cooling,  the  charge  is 
transferred  to  a  beaker  and  digested  with  water 
and  1  CO.  of  bromine.  It  is  then  acidulated 
with  hydrochloric  acid,  the  bromine  boiled  o£F, 
and  the  sulphur,  now  in  the  form  of  sulphate, 
precipiteted  by  barium  chloride.  The  sulphur 
may  also  be  oxidised  by  heating  the  coal  with 
a  mixture  of  nitre  and  common  salt.  Phos- 
phorus in  coal,  if  determined  at  all,  is  estimated 
in  the  ash,  which  may  require  complete  analysis. 

The  coking  qualities  of  coal  are  examined  by 
heating  50  grams  of  coarsely  crushed  coal  in  a 
*  large  copper '  crucible  covered  with  a  closely 
fitting  lid.  The  evolution  of  gases  is  completed 
after  15  or  20  minutes  at  a  full  red  heat.  After 
cooling,  the  coke  is  turned  out  and  weighed,  the 
loss  of  weight  giving  the  amount  of  volatile 
matter. 

The  oaldrific  power  of  coal  is  determined  by 
igniting  2  grams  of  the  finely  powdered  sample 
with  20  grains  of  a  mixture  of  six  parte  of  po- 
tassium chlorate  and  one  part  of  nitre.  The  coal 
and  deflagrating  mixture  are  ground  together 
in  a  morter  and  ignited  in  a  l^ompson  calori- 
meter. The  error  due  to  loss  of  heat  oy  escaping 
gases,  Ac,  is  always  taken  as  one-tenth  of  the 
totsl  evolved.  The  calorific  power  reported  is 
the  weight  of  water  that  could  be  evaporated  at 
100*  and  700  mm.  pressure  by  a  unit  weight  of 
the  fuel  {v.  Fuel). 

Cyanide  solntloiis.  In  gold  mills,  these 
solutions  are  in  wide  use,  and  require  frequent 
analysis.  Free  cyanide  is  estimated  by  means 
of  a  solution  of  silver  nitrate  prepared  by  dis- 
solving 13 "04  grams  of  crystallisea  AgNO,  in  a 
litre  Sf  water.  One  c.c.  of  this  solution  is 
equivalent  to  0*01  gram  of  KCy,  the  end  of  the 
titration  being  denoted  by  the  solution  becoming 
milky  from  the  precipitetion  of  AgOy.  The 
reaction  is  represented  by  the  equation : 

AgN0,-f2KCy=KAgCy,+KN0,. 

The  amount  of  cyanide  solution  taken  for 
assay  may  be  from  10  cc  to  100  cc,  according 
to  ito  strength.  AlkaUs  and  other  compounds 
which  may  be  present  dissolve  silver  cyanide, 
and  accordingly  it  is  usual  to  add  potassium 
iodide  as  an  indicator.  Turbid  cyanide  solution 
must  be  filtered  before  titration.  If  sduble 
sulphides  are  present,  they  prevent  the  assay 
from  being  carried  out.  They  are  removed  by 
agiteting  the  solution  with  freshly  precipitated 
iMid  carbonate.  If  zinc  is  present  in  the 
solution,  part  of  the  cyanide  contained  in  the 
double  cyanide  K,Zn(>V4  is  estimated  as  free  KCy. 
The  *  total  alkali  '^  in  a  cyanide  solution  is 
estimated  (J.  E.  Qennell,  Chemistry  of  Cyanide 
Solutions,  62)  by  titration  with  a  standard 
solution  of  sulphuric  acid,  using  methyl  oran^o 
as  an  indicator.  '  Protective  alkali  (op.  cti. 
63)  is  determined  by  adding  a  slight  excess 
of  silver  nitrate  together  with  a  litue  phenol- 
phthalein  solution,  and  titratinff  with  sulphuric 
acid  until  the  pink  colour  disapjiears.  The 
'  reducing  power    of  cyanide  solutions  is  deter- 


422 


ASSAYING. 


• 

mined  by  acidifioatioti  and  ftubae^uent  titration 
with  potassium  permanganate,  until  the  pink 
tint  becomes  permanent,  or  by  adding  an  excess 
of  permanganate  followed  by  an  excess  of 
potassium  iodide  and  estimating  tJie  amount 
of  iodine  liberated  (op.  cU.  71). 

Gold  and  silver  in  cyanide  solutions  are 
determined  by  evaporation  on  lead  foil,  which 
is  afterwards  cupelled,  or  by  evaporation  with 
litharge,  which  is  fused  for  lead.  A  more  rapid 
method  is  to  precipitate  the  gold  and  silver  with 
zinc-dust  and  sulphuric  acid,  filter,  and  scorify 
or  fuse  the  residue.  The  latter  method  is  espe- 
cially  saitable  for  treating  laree  samples  of 
poor  solutions  containing  very  uttle  gold  and 
silver.  In  all  these  methods,  a  button  of  lead  is 
obtained  which  is  cupelled  and  the  gold  and 
silver  parted  as  usual. 

Siliea.  The  silica  in  ores  is  partly  free  and 
partly  combined.  The  white  sandy  residue  left 
after  careful  extraction  with  acids  is  sometimes 
nearly  pure  silica,  and  is  often  reported  as 
*  silica  and  silicates  insoluble  in  acids.^  It  may 
be  tested  with  sulphuric  and  hydrofluoric  adds. 
The  usual  method  with  ores,  slags,  &c.,  is  to 
fuse  I  gram  with  5  grams  of  fusion  mixture 
and  a  little  nitre  in  a  platinum  crucible  or  dish. 
'It  is  extracted  with  warm  water  and  a  little 
hydrochloric  acid  and  evaporated  to  dryness  on  a 
water-bath.  The  bases  are  dissolved  out  with 
hydrochlorio  acid,  and  the  silica  filtered  off. 
Ijie  filtrate  is  again  taken  to  dryness  and  dis- 
solved in  hydrochlorio  acid  to  separate  the 
remainder  of  the  silica.  If  the  ore  contains  a 
lar^e  percentage  of  sulphides,  oiddes,  &c., 
which  rje  soluole  in  acios,  these  are  removed 
before  the  fusion.  In  this  case  the  acid  solution 
ma^  contain  silica,  which  is  removed  by  evapo- 
ratmg  to  dryness,  taking  up  with  hydrochloric 
acid  and  filtering.  The  purity  of  the  silica  is 
tested  by  evaporating  two  or  three  times  with 
water,  sulphuric  acid  and  hydrofluoric  acid.  The 
silica  is  volatilised  (J.  Amer.  Chem.  Scib.  xxiv. 
1902,  362). 

Sulphur.  A  rapid  method  of  determinins 
the  sulphur  in  ores  given  by  Furman  (Manuu 
of  Practical  Assaying,  5th  ed.  91)  is  to  fuse 
5  grams  of  the  ore  with  16  grams  of  borax,  3 
grams  of  charcoal,  and  one  or  two  nails  in  a 
hot  fire.  The  time  required  for  fusion  is  about 
15  minutes.  The  nails  are  then  withdrawn  and 
the  charge  poured.  As  soon  as  the  slac  is  cool, 
the  matte  is  detached  from  it  with  a  nammer 
and  weighed.  If  the  matte  were  pure  FeS,  it 
would  contain  36*3  p.c.  of  sulphur.  By  analysis, 
Furman  finds  that  the  nearest  approximation  is 
to  take  the  sulphur  as  30  p.c.  of  tne  matte.  The 
method,  though  inaccurate,  is  sometimes  useful, 
as  it  can  be  completed  in  less  than  half  an  hour. 

The  more  accurate  methods  consist  in 
oxidising  the  sulphur  by  o^iia  regia  or  nitric 
acid  and  potassium  chlorate,  or  by  fusion  with 
a  mixture  of  nitre  and  sodium  carbonate,  and 
weighing  it  as  barium  sulphate.  A  good  method 
for  ores  and  slags  consists  in  fusion  with 
caustic  alkali,  extracting  with  water,  and  oxidis* 
ing  with  bromine.  After  separation  of  the  silica, 
the  sulphur  ia  precipitated  by  barium  chloride 
(Chem.  News,  i.  1884, 194).  If  lead  is  present, 
the  solution  is  boiled  with  ammonium  car- 
bonate. T.  K.  R. 

ASTATKI.    A    Russian    term,     signifying 


'dr^s,'  applied  to  the  residue  left  in  the  dis- 
tillation of  Baku  petroleum  after  the  volatilisa- 
tion of  the  kerosene,  and  now  largely  used  as 
fuel  in  the  Caspian  region  {v.  PaTBOiauM). 

ASTERIA  (star  Sapphire)  v.  Cobundxtm. 

ASTERIN  V.  Antbooyanins. 

ASTEROL.  A  combination  of  the  mercury 
salt  of  jp-phenol-sulphonic  acid  (hydragyrol)  and 
ammonium  tartrate 

C„HioO,S,Hg,4[C,H,0,(NH,),1.8H,0. 
used  as  an  antiseptic  in  surgery.    « 

ASTRAUNE.  Russian  petroleum  oil,  used 
for  burning  (v.  Pstbolbum). 

ASTRAUTE.  A  glass  resembling  aven- 
turine,  but  containing  crystals  of  a  cupreous 
compound  which  by  reflected  light  exhibit  a 
dichroio  iridescence  of  daak  red  and  greenish- 
blue.  Hade  by  fusing  and  allowing  to  cool 
slowly  a  mixture  of  80  pts.  silica,  120  lead  oxide, 
72  sodium  carbonate,  18  borax,  with  either 
24  pts.  scale  oxide  of  copper,  and  1  pt.  scale 
oxide  of  iron,  or  with  5  pts.  lime,  26  copper 
oxide,  and  2  iron  oxide. 

ASTROUN.  Trade  name  for  antipyrine- 
methyl-ethyl  glycollate  C,HxoO„CiiHi,ON,, 
m.p.  64*-66'6®.  A  colourless  powder,  with  a 
slight  smell  and  pleasant  taste,  readily  soluble 
in  water  and  alcohol. 

ASUROL.  Sodium-mercuri-amido-oxyMO- 
butyrosalicylate. 

ASYPHIL.  Trade  name  for  a  mercury  aaU 
of  p-aminophenylarainic  acid 

(NH,C.H4AsO(OH)0),Hg  . 

{v.  Absbnioals,  Oboakio). 

ATACAMITE.  Hydrated  oxychloride  of 
copper  OuCl,'30u(OH),,  occurring  in  the 
Atacama  r^ion  of  Chile,  sometimes  in  sufficient 
amounts  for  use  as  a  copper  ore  (Cu  59*4  p.c). 
Large  quantities  have  also  been  mined  at 
Wallaroo  in  South  Australia.  Orthorhombic 
crystals  of  a  bright-green  colour  and  with 
bnlliant  faces  are  not  uncommon.  Sp.gr.  3*76. 
Before  the  days  of  blotting-paper,  it  was  used, 
under  the  name  of  arsenillo,  as  a  writing;  sand 
for  absorbingink  {v.  Cofpbb).  L.  J.  8. 

ATELESITE.  A  bismuth  arsenate  con- 
taining  iron  phosphate  found  at  Schneeberg  in 
Saxony  :  Bi,0„  5715  ;  Fe,P,0„  12-60  ;  As.O,, 
30*35  (Frenzel,  J.  M.  1873.  786). 

ATHAR  or  ATTAR,  Indian  name  for 
volatile  oil  of  roses  {v.  Oils,  Essbntial). 

ATISINE,  V.  AcoNiTiNB. 

ATLAS  DYNAMITE  v.  Exflosivbs. 

ATLAS  POWDER  v.  Explosives. 

ATLAS  SCARLET  v.  Azo-  coloubino 
kattbbs. 

ATMOSPHERE.  The  gaseous  envelope  sur- 
rounding any  liquid  or  sohd  body ;  more  part* 
oularly  the  gaseous  envelope  which  surrounds 
the  earth,  and  which  is  commonly  known  as  air. 
The  thickness  of  this  aerial  envelope  is  not 
known  even  approximately,  but  it  is  quite  certain 
that  it  exceeds  45  miles  measured  from  the 
earth's  surface,  which  was  the  limit  assigned  to 
it  by  WoUaston.  Secchi  calculated  that  air 
exists  even  at  a  height  of  300  kUometree  above 
the  earth's  suriace.  From  the  ratio  of  decrease 
of  density  with  elevation,  the  atmosphere  at 
a  height  of  50  miles  cannot  exert  any  measurable 
pressure.  The  mass  of  the  atmosphere  forms, 
like  the  earth  itself,  an  oblate  spheroid,  the  polar 


ATMOS^liEREl. 


ftxiB  of  wiuch  is  mooh  shorter  clian  the  equatorial 
axis,  the  ratio  of  the  two  axes  being,  accordmg 
to  Laplace,  as  2  to  3. 

The  pressure  of  the  atmosphere  at  any  par- 
ticular spot  may  be  measured  in  terms  of  the 
height  of  a  column  of  mercury  which  it  is  capable 
of  Bustainine.  It  follows  from  the  law  of 
Boyle  that  tne  density  of  the  air  rapidly  dimi- 
nishes with  the  hei^nt.  For  air  of  constant 
temperature,  its  density,  or,  what  comes  to  the 
same  thing,  the  height  of  the  mercurial  column, 
should  diminish  in  geometric  progression,  whilst 
the  distance  from  the  earth  increases  in  arith- 
metic progression.  The  nressure,  even  at  the 
same  place,  is  continually  yaryin^  from  a 
yariety  of  causes,  and  hence  the  height  of  the 
barometer,  as  the  mercurial  column  was  first 
termed  by  Boyle,  is  practically  neyer  absolutely 
constant.  The  ayerage  height  at  any  one  spot 
at  the  sea-leyel  is  mainly  dependent  upon  the 
great  moyements  of  air  which  result  from  the 
effect  of  the  earth's  motion  upon  the  gaseous 
enyelope,  combined  with  yariations  m  the 
density  of  the  aerial  mass  due  to  solar  action. 

According  to  Regnault,  1  litre  of  dry  air,  free 
from  carbonic  acid  and  ammonia,  measured  at 
0*"  and  0-76  mm.  pressure,  at  Paris  (lat.  48*  60') 
and  at  a  height  of  60  metres  aboye  the  sea-leyel, 
weighs  1  '293 1 87  grams.  Lasch  found  that  1  litre 
of  pure  air  at  standard  temperature  and  pressure 
weighs  at  Berlin  (kit.  &2''  360  1-293035 
grams. 

Guye  found  1*2030  grams  at  Geneya,  and 
concluded  that  it  may  yary,  on  the  same  day, 
from  place  to  place  to  the  extent  of  seyeral 
tenths  of  a  milligram  (Guye,  Koyacs  and 
Wourtzel,  Ck>mpt.  rend.  1912,  154,  1584).  The 
mean  of  the  most  recent  determinations  giyes 
the  yalne  1*2928  grams  as  the  weight  of  a  normal 
litre  of  air.  Guye  considers  that  the  moat 
probable  explanation  of  the  yariations  in  density 
observed  from  time  to  time  is  based  on  the 
presence  in  the  air  of  yarying  quantities  of  dust, 
inyisible  under  the  ultramicroscope. 

The  Bureau  Intemat.  des  Poids  et  Mesures 

adopts  for  the  weight  of  1  litre  of  dry  air,  con- 

tainmg  0'04  p.c.  carbonic  acid,  at  the  normal 

.temperature,  and  under  the  normal  barometric 

pressure  at  lat.  45*  and  sea-leyel, 

P   =   1M3062        J^ 
•^    1  +  oooser  ^  Teo' 

on  the  assumption  that  0*00367  is  the  expansion 
coefficient  of  air  at  constant  pressure  for  a 
normal  degree.  According  to  Ledno  the  mean 
composition  of  air  at  Paris,  purified  from 
aqueous  yaponr  and  gases  absorbable  by  alkali, 
is  aa  follows : 

Oxyffen    Kltrogea      Arffon         Neon 
Byyolume     0-2100        0-7ft06        0*0094        16x10-* 
By  weight      0-2321        0*7640        0*0130       8*4X10-* 

Helium    Hydrogen     Krypton    JCenon 
Byyoluroe    0*6xl0-«       lxlO-«     50x10*     «xlO-» 
By  weight     0*7x10^  0*07  x  10"*   UOxlO"*  SOxlO"* 

For  such  air  at  0**  and  a  pressure  of  76  cm.  of 
mercury  at  Paris  the  mass  of  1  litre  is  found  to 
be  1*2932  grm.  Under  normal  pressure  (76 
cm.  of  mercury  at  0*" ;  g«=980  665)  the  weight 
Is  1*2928.  In  other  terms,  taking  the  sp.gr.  of 
mercury  as  13*5961  and  the  yalue  of  g  at  the 
4th  atofy  of  the  Sorbonne  aa  980*97,  the  mass 
of  a  litre  of  air  under  the  pretfuie  of  a  megabar 


is  1*2759  grm.  For  purposes  of  ordinary 
chemical  calculation  it  may  be  assumed  with 
sufficient  accuracy  that  1  gram  of  air  measures 
at  standard  temperature  and  pressure  773  c.c. 

The  total  weight  of  the  atmosphere  is  about 
11  'trillions  of  pounds,  or  about  5  trillion  kilo- 
grams and  the  relatiye  amounts  of  the  chief 
constituents  may  be  assumed  to  be — 


Nitrogen  (argon,  &c.) 
Oxygen  .  .         • 

Carbonic  acid  • 


Trillions  kgm. 
.     4-04 12U0 
•     1*218040 
.     0-003156 


5*262396 


Herschcl  calculated  that,  allowing  for  the 
space  occupied  by  the  land  aboye  the  sea,  the 
mass  of  tJie  atmosphere  is  about  YvAnra  P^^  ^^ 
that  of  the  earth. 

The  unit  of  pressure  adopted  by  engineers 
and  others,  and  styled  an  aimospnere,  is  an 
amount  equal  to  the  ayerage  pressure  of  the 
atmosphere  at  the  sea^s  leyel.  In  British 
measure  an  atmosphere  ii  the  pressure  equiyalent 
to  29-905  inches  of  mercury  at  32^  F.  at  London, 
and  is  about  14-73  lbs.  on  the  sq.  inch.  In 
the  metric  system  it  is  the  pressure  of  760  mm. 
(29-922  inches)  at  O""  C.  at  Paris,  and  is  equal' to 
1-033  kilos  on  a  sq.  centimetre.  Hence  the 
English  *  atmosphere'  is  0*99968  that  o^  the 
metric  system. 

The  specific  heat  of  air  at  constant  pressure 
is  0*239  (Hercus  and  Laby).  Its  coefficient 
of  thermal  expansion  between  —30°  and  200°  is 
0*003665  for  T.  Its  thermal  conduotiyity  is 
5*22x10—*  caL/cm.  sec.  deg.  (Hercus  and  Laby, 
Proo.  Roy.  Soc.  1918,  A,  206).  Its  yiscosity 
(No  XlO«)= 1-733. 

By  the  application  of  sufficient  cold  and 
pressure,  air  may  be  liquefied. 

Comparatiyely  little  of  the  sun's  heat  is 
absorbed  in  its  direct  passage  through  the  air. 
According  to  Tyndall,  a  column  of  air  1  metre 
long  absorbs  0*088  p.c.  of  the  heat  which  passes 
through  it.  Accoroing  to  Violle,  and  also  Lecher 
and  Pemter,  the  amount  is  not  greater  than 
0*0070  p.c.  This  absorption  is  mainly  due  to 
aqueous  yapour,  and,  in  a  lower  degree,  to  car- 
bonic acid  and  suspended  organic  matter.  The 
air  mainly  gets  its  neat  by  conduction  from  the 
earth,  and  hence,  as  a  rule,  it  is  hottest  near  the 
ground.  The  law  of  the  decrement  in  tempera- 
ture corresponding  to  height  is  not  accurately 
known ;  it  ii  usually  stated  to  be  about  0-56* 
per  100  metres,  but"  the  rate  ii  liable  to  yery 
great  yariations. 

Air  is  not  perfectly  transparent.  Its  particles 
reflect  and  scatter  light  in  sufficient  quantity  to 
obscure  the  light  from  the  stars.  The  olue  colour 
of  the  sky  is  due  to  the  fact  that  the  most  re- 
frangible rays  are  most  widely  scattered  (c/ 
Rayleiffh,  Phil.  iiag.  1899,  47,  375).  Strutt  has 
deyiaed  a  method  of  showing  the  scattering  of 
light  by  dust-free  air  and  of  artificially  repro- 
ducing the  blue  colour  of  the  sky  (Proc.  Ivoy*  ooc. 
1918,  94  A,  453;  see  also  Cabannes,  Gompt. 
rend.  1915, 160, 62).  In  the  higher  r^ons  of  the 
atmosphere,  where  the  amount  of  reflected  light 
becomes  less  and  less,  owing  to  the  decreased 
density  of  the  air,  the  sky  appears  to  grow 
graduaUy  darker.  Brewster  first  proyed  that 
the  blue  light  from  the  sky,  aa  well  as  the  white 


424 


ji  due  t 


ATMOSPHERE. 

reaecltd  liglit, 


(ZeiUoh.  anal.  Chom.  ISTO.  IS,  U 
■ticks  of  pboBpboniB  for  the  s 

tho   Omt  »ppsnitiu   {v.  Qia ,.     __ 

a  temperature  below  7°  the  oxidatioll  of  the 
phoaphoniB  ceaseB.  Watoon  (Chem.  Soa  Trans. 
1911,  99,  1460)  has  daaoiibad  an  aooomW 
method  of  aaoerlAining  the  amount  of  oxygen  in 
air  t^  the  nae  of  fellow  phoflphorns.  A  modifi- 
caUoD  of  the  appantua  foi  eatunating  tite  oxjtea 
oonterat  of  air  from  the  npper  atmosphere  nu 
been  snggested  by  Aaton  (Chem.  Soc.  Trans, 
leip.  472). 

2.  Pyrogaitol  in  Alkaline  soluiion.  Gberreul, 
in  1820,  first  suggested  the  use  of  thia  reagent. 
The  absorption  is  apt  to  be  aooomponied  bj  the 
formation  of  notable  quantities  of  carbon 
monoxide  if  the  amonnt  of  oxygen  is  large  or 
the  alkaline  solution  very  concentrated.  Accord- 
ing to  Hempel  (Ber.  20,  1865),  tiie  best  pro- 
portions arp  SgramspTrt^alloldisBolvedin  IQe.o. 
water  mixed  with  120  grams  caustic  potaab  dis- 
solved in  80  cm.  of  wat«r.  Fraotically  no 
carbon  monoiide  is  formed  with  this  solution. 
The  absorption  is  very  rapid  (Hempel,  Ber.  IS, 
367  and  1800).  Ouye  and  Germann  have 
described  a  volumeter  by  which  it  ia  poeable 
to  analyse  acoonitely  very  small  qnantities  of 
air  (0-2B  e.o.)  [Compt.  rand.  1014,  169,  ItH). 

3.  MetalXie  Copper.  A  spiral  of  copper  wiro 
is  heated  to  redness  in  dry  air  free  from  carbonic 
acid  and  of  known  pressure  nntil  the  whole 
of  the  oxygen  baa  combined  with  tho  metal 
bo  form  ouprio  oxide.  The  preasnre  of  the 
regidual  gas  is  then  determined,  wherebv  the 

^  amount  of  nitrogen  ia  ascertained,  atid  hence 

alterations  in  temperature.        '  the  amount  of  oxygen.     An  apparatus  on  thia 

of  nitrogen,  oxygen,  aqueous  ,  principle  was  suggroted  by  Jolly  {W.  N.  8. 6638) ; 


light  from  the  clouds,  was 

by  the  fact  that  it  was  polarised. 

Soapended    matter,    dust,    smoke,    aqneona 
vapour  in  a  state  of  partial  precipitation,   &a,, 
greatly  HI  mini  «h  the  transparency  of  air.     Wild 
gives  the  followin 
transparancy  coef 

I^  air  (free  from  duet)      .         .         .    0-90718 
Air  of  a  room   (dry,   but  containing 

dnat)    ......    0-99620 

Air  froe  from  dust,  bat  saturated  with 

aqiuous  vapour      ....    0-09328 

The  refractive  indioee  of  dry  air  at  standard 
temperature  and  prcsaure  for  the  Fraunhofcr 
lines  A,  B,  C,  D,  E,  F,  G,  H,  are,  aooordiog  to 
Kettler  (Pogg.  Ann.  124-401),  as  foUows  :— 
nA  =  l-0002»286      I      i.E-l-000296g4 
nB=l-0002934B  »F=1-00029685 

nC^l-00020383  nG=I-00029873 

t>D= 1-00029470  I  nH~l-O003O026 
The  emission  spectmm  of  air  has  been  mapped 
by  Hugging  (Phil.  Trana.  154,  139)  and  Ang- 
strom (Pogg.  Ann.  94,  141),  and  the  spectrum 
of  lightning  by  Knndt  (Fogg.  Ann.  136,  316), 
who  has  shown  that  forkea  lightning  gives  a 
line  Bpsctrum,  whereas  sheet  lightning  gives  a 
band  spectrum.  The  absorption  spoQtrum  of 
air  was  first  mapped  by  Brewster  and  Gladstone, 
and  has  been  further  examined  by  Janssen, 
Comn,  and  Chappuis  (Compt,  rend.  Ql,  988). 

Air,  owing  to  the  oiygen  it  contains,  is  a 
magnetic  substance.  The  diurnal  variation  in 
magnetic  declination  has  been  allied  to  be 
due  to  the  varying  magnetic  potential  of  the 
oxygon  owing  to  alterations  in  temperati — 

Air  is  a  mixture  of  nitrogen,  oxygen, 
vapour,  argon,  carbon  dioxide,  with 
quantities  of  ozone,  hydrogen  perosine,  am- 
monia, nitrous  and  nitric  acids,  nydrocorbons, 
helium,  neon,  krypton,  xenon,  hydrogen,  &0. 
That  Uie  air  is  not  a  chemical  compound 
of  its  component  gases  is  proved  by  the  facte : 
(1)  that  these  gasea  ara  not  present  in  any 
constant  ratio ;  (2)  that  air  can  be  made  by 
simply  mi  ling  its  constituente  in  the  proportion 
indicated  by  the  analysis  of  air,  without  con- 
traction 01  any  thermal  disturbanoe  resulting ; 
(3)  that  on  treating  air  with  water  and  expelling 
the  dissolved  air  by  boiling,  the  proportion  (h 
the  o^gen  to  the  nitrogen  is  foond  to  be  in - 
cnuwed,  and  in  amount  oorreeponding  with 
the  law  of  partial  pressures ;  (4)  that  the 
constituents  of  the  air  can  be  mochanioally 
separated  by  processes  of  diSusion ;  and  (6)  that 
the  refractive  power  of  the  air  is  equal  to  the 
mean  of  the  refractive  powers  of  its  constituents, 
whereas  in  compound  gases  the  refractive  power 
is  either  greater  or  less  than  the  refractive  power 
of  the  elements  in  a  state  of  mixture. 

The  amonnt  of  oxygen  in  air  may  be  ascer- 
tained by  measuring  tlie  diminution  in  volume 
which  a  known  bulk  experiences  when  in  contact 
with  some  substance  capable  of  absorbing  or 
combining  with  oxygen  gas.  Among  the  sub- 
stances which  may  be  oonvem'ently  used  for  this 
purpose  are: 

1.  PhotphoTM.  A  fragment  of  phosphorus 
OD  the  end  of  a  platinum  or  copper  ^viro  is 
exposed  to  a  measuiod  volume  of  air  standing 
over  water  or  mercury  until  no  further  decrease 
of  volume  is  observed  (Borthollel).     iindemann 


Fig.   1. 
replenishtd  with  tho  air   under  i 
This  II   then  cooled   to  0°   by  si 


ATMOSPHERE. 


425 


liith  the  metaUic  cylinder  fi,  which  is  filled 
with  melting  ice.  The  tension  of  the  confined 
air  is  measured  by  the  height  of  mercury  in  the 
glass  tubes  g  and  d,  which  are  connected  to- 
gether by  caoutchouc  tubing.  The  tube  g  is 
movable  in  the  clamp  /,  the  position  of  d  being 
fixed  with  reference  to  a.  By  turning  the  three- 
way  stop-cock  h,  A  and  d  may  be  alone  brought 
into  connection,  or  both  may  be  made  to  connect 
with  the  outer  atmosphere.  Tlie  cock  is  now 
so  turned  that  a  and  a  are  alone  in  connection  ; 
the  tube  ^  is  now  raised  until  the  level  of  the 
mercury  in  d  just  touches  the  point  m,  when 
the  tension  of  the  air  is  read  off  on  the  graduated 
scale  behind  g.  '  The  copper  spiral  in  a  is  next 
heated  to  redness  by  an  electric  current,  whereby 
the  heated  metal  rapidly  combines  with  the 
oxygen.  The  cylinder  b  is  onoe  more  placed 
round  a,  the  residual  nitrogen  cooled  down  to  0^ 
by  means  of  melting  ioe,  and  its  tension  measured 
by  adjusting  the  level  of  the  mercury  to  m,  and 
reading  off  the  height  of  the  mercury  in  g. 
If,  for  example,  the  pressure  before  abstracting 
the  oxygen  was  702-56  mm.,  and  after  the  ab- 
straction was  555*70  mm.,  then  1  volume  of  the 

air  would  be  reduced  to=^^^=0-79096  vol., 

or,  expressed  centesimally,  the  composition  of 
the  air  would  be : 


Nitrogen  (argon,  Ac.) 
Oxygen 


79-006 
20*904 


lOOOOO 
Kreusler  has  shown  that  unless  the  air  be  care- 
fully dried  before  being  heated  with  the  copper 
spiral,  the  proportion  of  oxygen  will  be  apparently 
too  low. 

Dumas  and  Boussingault  (Ann.  Chim.  Phys. 
rS]  3257),  as  far  back  as  1841,  made  use  of  the 
fact  that  heated  metallic  copper  combines  with 
oxygen,  in  order  to  determme  the  gravimetric 
composition  of  air.  Air  deprived  of  moisture 
and  carbonic  acid  was  passed  through  a  weighed 
tube  containing  metallic  copper  heated  to  red- 
ness, whereby  all  the  oxygen  was  absorbed,  the 
nitrogen  being  collected  in  a  vacuous  glass  globe 
also  previously  weighed.  At  the  conclusion 
of  the  experiment  the  tube  containing  the 
metallic  copper  was  again  weighed ;  the  increase 
in  its  weight  gave  the  amount  of  absorbed 
oxygen,  together  with  the  weight  of  the  nitrogen 
which  it  also  contained.  The  nitrogen  was  then 
removed  by  the  air  pump  and  the  tube  again 
weighed ;  the  difference  oetween  the  first  and 
third  weighings  of  the  tube  containing  the  copper 
gave  the  weight  of  absorbed  oxygen,  and  the 
weight  of  nitrogen  was  obtained  by  adding  the 
difference  between  the  second  and  third  weighings 
of  the  tube  to  the  increase  in  the  weight  of  the 
glass  globe.  As  the  mean  of  a  large  number 
of  experiments  made  by  this  method,  the 
precentage  composition  by  weight  of  air  free 
from  water  and  carbonic  acid  was  found  to  be 


Oxygen  . 

Nitrogen  (with  argon,  &c.) 


23-00 
77-00 


100-00 

Leduc  has  shown  that  this  proportion  of 
oxygen  is  too  low,  as  an  average  ;  the  amount 
is  about  23*2  p.c.  by  weight  as  calculated  from 
the  kno^vm  density  of  air  and  of  its  constituent 


gases  (Compt.  rend.  1896,  12,  1805 ;  1803,  126, 
413).  • 

4.  Exphn'on  with  hydrogen,  A  measured 
volume  of  air  is  mixed  with  a  known  volume  of 
hydrogen  in  excess,  and  the  mixture  is  exploded 
by  the  electric  spark,  when  the  oxy^n  combines 
with  the  hydrogen  in  the  proportion  of  1  vol. 
of  the  former  to  2  of*  the  latter  to  form  water. 
One-third  of  the  contraction  resulting  from  the 
explosion  represents*  therefore,  the  amount  of 
oxysen  in  the  air  under  examination.  This 
method,  first  suggested  by  Volta,  was  perfected 
by  Bunsen.  Modifioations  of  the  method  have 
been  made  by  Regnault  and  Reiset,  Williamson 
and  Russell,  FraiQdand  and  Ward,  and  others. 
These  methods  are  extremely  accurate,  and 
have  afforded  us  all  the  exact  knowledge  we 
have  respecting  the  variations  in  the  amount  of 
oxygen  in  atmospheric  air.  Thus  Bunsen,  in  a 
eeries  of  analyses  made  in  the  winter  of  1846, 
found  that  the  percentage  amount  varied  from 
20-97  to  20-84.  Reffnault  made  a  large  number 
of  analy^^es  of  air  c<3leoted  from  all  parts  of  the 
world.  In  100  analyses  of  air  collected  in  Paris 
the  minimum  amount  of  oxygen  was  20-913,  the 
maximum  20  -999.  Air  collected  in  various  parts 
of  Europe,  from  above  the  Atlantic  Ocean,  from 
the  summits  of  the  Andes  and  firom  tiie  South 
Polar  Sea,  contained  an  amount  of  oxygen  vary- 
ing from  20-86  to  21  p.c.  Many  hundreds  of 
analyses  were  made  by  Angus  Smith,  of  air 
collected  in  various  towns  in  England  and 
Scotland,  and  also  of  air  collected  in  the  country. 
The  oxygen  in  London  air  VMi^d  from  /20'857  to 
20-95,  less  oxygen  as  a  rule  being  found  in  the 
air  of  streets  than  in  that  of  the  parks  and  open 
spaces.  A  series  of  30  analyses  of  Glasgow  air 
showed  variations  from  20-887  in  the  closer 
parts  to  20*929  in  the  more  open  spaces.  Even 
wider  extremes  were  found  by  Leeds  in  the  air 
of  New  York,  viz.  from  20*821  to  21029  p.c. 
According  to  E.   W.  Morley,  the  diminished 

Proportion  of  oxygen  may  be  caused  by  the 
own-rush  of  air  from  the  higher  regions  of  the 
atmosphere,  which  probably  contain  a  less 
relative  amount  of  oxygen.  Regnault*s  experi- 
ments afford  some  evi<Mnce  for  the  belief  that 
the  air  of  the  tropics  contains  slightly  less 
oxygen  than  that  in  northern  latitudes  (v.  also 
Jolly,  W.  N.  F.  61,  520).  A  similar  conclusion 
has  been  drawxwby  Hempel  (Ber.  20, 1864)  from 
the  analysis  of  a  large  number  of  analyses  of 
air  collected  simultaneously  at  Tromso,  Dresden, 
and  Para.    The  mean  results  were : 


TromsS 

Dresden 

Para 


Oxygen. 
20-92 

20*90 

20*89 


From  the  results  of  203  analyses  of  air  col- 
lected at  five  different  spots  and  analysed  by 
three  independent  methods,  it  follows  that  the 
most  probable  mean  percentage  amount  of 
oxygen  is  20*95.  Numerous  determinations 
by  Pettersson  and  Hdgland  of  the  air  of  Stock- 
holm during  October,  November,  and  December, 
1889,  gave  0^=20-94  (Ber.  22,  3324 ;  Hempel, 
Ber.  20,  1864;  Kreusler,  Ber.  20,  991).  More 
recent  work  by  Durius  and  Zuntz,  Watson 
(Chem.  Soc.  Trans.  1911, 99, 1460),  and  Benedict 
(Carnegie  Inst.  Report,  160),  indicates  that  such 
small  variations  as  occur  are  not  traceable  to 


426 


ATMOStHERB. 


metooroloffical  conditioiid.  The  mean  per- 
centage of  oxygen  (20'952)  found  by  Benedict 
from  1909  to  1912  oorreeponds  closely  with 
that  found  by  Morley  (20 -95^)  in  1881. 

Air  from  vaiioua  parte  of  Fnuioe,  the  Alps, 
and  Algiers,  taken  both  in  spring  and  winter, 
was  found  by  Leduo  to  show  on  an  average 
23 '20-23 '21  p,o.  of  oxygen  by  weight,  the 
extreme  values  being  23 '05  and  23*26  p.c.  The 
percentage  is  s%htly  lower  in  the  north  and  at 
sea-level  than  ebewhere,  and  is  less  in  London 
than  in  Paris.  Samples  oi  the  upper  air  are 
less  rich  in  oxygen  tluin  air  at  the  level  of  the 
earth,  although  the  difiFezences  are  much  1ms 
than  are  indicated  by  the  law  of  Laplace. 

Ozone  is  always  present  in  minute  quantity 
in  normal  air.  Air  over  marshes  contains  little 
or  no  ozone.  No  osone  can  be  detected  in  the 
air  of  laise  towns  or  in  inhabited  houses. 
Atmospheric  ozona  is  probably  formed  by  the 
action  of  electricity  on  air.  Most  of  the  informa- 
tion we  at  present  possess  concerning  the  distri- 
bution of  atmospheric  ozone  has  been  obtained 
by  the  use  of  so-called  ozone  papers.  Of  these 
the  best  known  is  Sch5nbein*s,  which  is  based 
on  the  fact  that  ozone  liberates  iodine  from 
potassium  iodide,  and  thereby  renders  starch 
Dlue.  To  prepare  them,  unsised  paper  is 
immersed  in  a  solution  of  16  parts  starch  and 
1  part  potassium  iodide  in  200  parts  of  water 
and  dried  in  the  dark.  To  make  a  determina- 
tion of  ozone  the  paper  is  freely  eixposed  to  the 
air  for  some  hours  and  moirtened  with  water, 
and  the  depth  of  tint  produced  compared  with  a 
standard  scale  of  colour.  The  method  has  no 
pretensions  to  scientific  accuracy.  Houzeau 
(Ann.  Chim.  Phys.  4,  27,  5)  determines  the 
relative  amount  of  ozone  by  exposing  red  litmus 
paper  previously  dipped  in  1  p.c.  soL  of  potassium 
iodide  and  drie!a,  to  the  action  of  the  air.  The 
ozone  liberates  iodine  and  the  free  alkali  turns 
the  paper  blue.  Thallium  salts  are  turned  brown 
by  me  action  of  ozone,  and  hence  papers  soaked 
in  solution  of  these  salts  have  been  used  for  the 
recognition  of  ozone.  Paper  soaked  in  a  very 
dilute  solution  of  neutral  gold  chloride  is  turned 
a  deep  violet  colour  by  ozone  (Bottger,  Chim. 
Zentr.  1880,  719). 

Attempts  have  been  made  to  estimate  ozone 
bv  aspirating  larse  volumes  of  air  through 
dilute  solutions  of  nvdriodic  acid  and  determin- 
ing the  amount  of  the  liberated  iodine  bv  iodo- 
metric  anivlysis.  Also  by  leading  the  air  tnrough 
a  mixed  solution  of  potassium  arsenite  and 
potassium  iodide,  whereby  the  liberated  iodine 
converts  the  arsenite  to  arsenate.  The  liquid 
through  which  the  air  had  passed  was  tnen 
mixed  with  a  few  drops  of  ammonium  carbonate 
solution  and  starch  paste,  and  a  standard  solu- 
tion of  iodine  (1 :  1000)  added  until  the  blue 
colour  was  permanent  A  precisely  similar 
experiment  was  made  on  equal  amounts  of 
distilled  water,  iodine,  arsenite,  A;o.,  used,  and 
from  the  difference  in  the  amount  of  iodine 
solution  needed  the  amount  of  oxidised  arsenite 
and  hence  the  quantity  of  ozone  was  determined. 

According  to  David  (Compt.  rend.  1917, 
164,  430)  the  ozone  in  air  may  oe  estimated  bv 
adding  5  c.o.  of  J^/100-ferrons  ammonium  sul- 
phate acidified  with  sulphuric  acid  to  a  vessel  of 
1  litre  capacity,  and  tnen  titrating  back  with 
N/IOOO  potassium  permanganate. 


Pring  (Proc.  Roy.  Soc.  1914,  A  90,  204),  by 
observations  on  the  action  of  ozone  on  aqueous 
solutions  of  potassium  iodide,  with  the  forma- 
tion of  hypoiodite  and  free  iodine,  finds  that  the 
average  amount  of  ozone  in  the  atmosphere  is 
2-6  vols,  per  million  of  air,  and  that  this  amount 
varies  very  little  with  the  altitude  between 
5  and  20  kilometres.  In  the  Alps  a  mean  value 
of  2-6  vols,  was  observed  at  2100  metres,  and  4 '7 
vols,  at  3680  metres.  Pring  r^ards  ozone  as  a 
contributing  factor  in  determining  the  blue 
colour  of  the  sky.  The  use  of  potassium  iodide 
as  an  agent  for  the  estimation  of  atmospheric 
ozone  is  deprecated  by  Usher  and  Rao  (Ohem. 
Soc.  Trans.  1917,  111,  799),  who  have  devised 
a  method  in  which  the  air  to  be  examined  is 
shaken  with  a  dilute  standard  solution  of  sodium 
nitrite  made  slightly  alkaline ;  and  the  on- 
changed  nitrite*  content  subsequently  deter- 
mined colorimetrieally  by  the  production  of 
the  red  dye  with  a-naphthylamine  and  sul- 
phanilio  acid  (Griess-Ilosvay  method).  For 
particulars  the  original  description  must  be 
consulted. 

It  appears  that  the  amount  of  ozone  varies 
with  the  seasons :  it  is  greatest  in  winter,  be- 
comes gradually  less  during  spring  and  autumn, 
and  is  least  in  summer.  Ozone  is  more  fre- 
quently observed  on  rainy  days  than  in  fine 
weather ;  thunderstorms,  sales,  and  hurricanes 
are  frequently  accompanied  by  relatively  strong 
manifestations  of  it  (c/.  Thierry,  Compt.  reno. 
1897,  124,  460). 

According  to  Holmes  (Amer.  Chem.  J.  1912, 
47,  497)  the  maximum  amount  of  ozone  in  the 
air  is  only  found  when  '  high  *  barometric  areas 
are  so  near  that  the  air  from  sreat  heights  flows 
rapidly  down  to  the  earth.  Most  of  the  ozone 
is  produced  by  the  action  of  the  8un*s  ultra* 
violet  rays  on  the  upper  air  (c/.  Stmtt,  Proc. 
Roy.  Soc.  1917,  94,  260).  According  to  Moore 
(Proc.  Roy.  Soc.  1918,  B,  90,  168),  the  '  ozone  * 
odour  in  air  is  probably  due  to  oxides  of  nitrpgen 
formed  by  the  action  of  sunlight  rich  in  ultra- 
violet light  in  the  upper  layers  of  the  atmosphere 
on  air  and  water-vapour. 

It  is  highly  probable  that  many  so-called 
ozone  manitestations  are  due  to  the  existence  of 
hydrogen  peroxide  in  the  air,  which  was  first 
demonstrated  by  Meissner  in  1863.  SohSne 
found  from  observations  made  at  Moscow,  that 
it  was  invariably  present  in  rain,  dew,  and  snow, 
and  was  less  in  winter  than  in  summer;  and 
more  in  southerly  winds  than  in  those  from  the 
norUi.  The  amounts  in  all  cases  were,  however, 
very  minute,  the  maximum  being  1*4  cc,  and 
the  mean  0*38  co.  hydrogen  peroxide  vapour 
in  1000  CO.  air. 

The  quantity  of  aquemu  vapour  in  the  air 
varies  .with  tiie  temperature :  thus  1  cm.  of  air 
when  saturated  with  water  contains : 


At-lO*"    2-284  grams 

At  +20'  17*167  grams 

0*   4*871    „ 

26^' 22*843    „ 

-f  6*»   6*796    „ 

30*  30*095    „ 

10*    9*362     „ 

36*39*262    „ 

16»  12-746    „ 

The  most  accurate  method  of  determuiing 
the  amount  of  aqueous  vapour  in  the  air  oonsists 
in  aspirating  a  given  volume  of  the  air  throQffh 
weighed  tubes  filled  with  some  h^ffrosoopio  sob- 
stance,   such  as  phosphoric  oxiae  or  pumioe 


ATMOSPHERE. 


427 


aoaked  in  oil  of  ritiiol  and  reweighing  the  tubes, 
when  the  increase  of  weight  gives  the  quantity  of 
moisture  present. 

Usually,  howeTer,  the  humidity  of  the  air  is 
estimated  by  means  of  hydrometers,  the  best- 
known  form  of  which  is  we  psychrometer  or 
wet-and-dzy-bulb  thermometer  of  August.  The 
abaohUe  humidity  of  the  air  is  the  weight  of 
aqueous  yapour  contained  in  1  am.  The  relative 
humtdity  denotes  the  rdation  between  the 
weioht  actually  present  and  that  which  could 
be  weoretioaUy  present  if  the  air  were  saturated ; 
it  is  usually  expressed  in  per  cent,  of  the  maxi- 
mum humidity.  The  air  ia  seldom  absolutely 
saturated  with  aqueous  vapour,  although  in  our 
moist  climate  saturation  is  occasionally  very 
nearly  attained.  With  us  the  most  humid 
month  is  December,  and  the  driest  is  July. 

The  presence  of  carbonic  acid  in  the  atmo- 
sphere was  first  indicated  by  Black  in  1752. 
xbe  quantity  in  normal  air  is  about  0*03  p.c. ; 
in  that  of  large  towns  it  is  slightly  greater. 
Ajngus  Smith  gives  the  following  summary  of 
results  obtained  in  London  in  1864  and  1869 
(Air  and  Rain,  69-58)  :— 
Over  River  Thames  .     8  expts.     0*0343  p.o. 
IntihePark       .         .     5      ,»        0*0301    „ 
In  the  streets    .         .  10      „        00380    „ 

Any  circumstance  which  interferes  with  the 
ready  diffusion  of  the  products  of  respiration 
and  of  the  combustion  of  fuel  will  tend 
to  increase  the  relative  amount  of  carbonic 
add  in  the  air  of  a  town :  hence  during  fogs 
the  amount  may  be  as  great  as  0*1  p.o. 

The  amount  of  carlK>nic  acid  in  the  air  of 
the  country  at  night  is  usually  greater  than  in 
the  day,  as  the  following  comparison  shows : — 

Air  in  ihe  day-time. 


Observer 

Tear 

Plaee 

Amount 

Fr.ScholM 
T.  AeUet    . 
G.  F.  Armstronc 
If  llntz  A  Aubin  . 
A.  Levy 
Petcrmann 
Brown  A  Btoombe 

it 

T.  Rdset    . 
0.  P.  Armstcong 

1861-71 
1878-«0 

1870 

1881 
1877-83 

1802 
1808-1001 

if  in  ihe  ni 

187»-80 
1870 

0*0202  p.e. 
0*0200   „ 
00200  „ 
00284  „ 
0*0200   „ 
0*0200   „ 
00204   „ 

0*0804  p.e. 
0*0880  „ 

These  di£ferences  are  mainly  due  to  the  ex- 
halation of  carbonic  acid  from  plants  at  nig^ht, 
and,  to  a  smaller  extent,  to  the  absence  of  wind 
and  of  any  decomposition  of  the  sas  by  the 
action  of  sunlight.  Over  the  sea  tnis  diurnal 
TSkriation  is  not  perceived,  as  the  following 
results  indicate : — 

Carbonic  <icid  in  sea  air. 


T.S.  Thorpe 


Irish  Channel 
aad  Atlaatic 
Ocean 


186&-e 


Day. 
Night 


0*0801  P.O. 
0*0200  „ 


Hean  0*0300 


In  cold  regions  the  dissociation  pressure  of 
hydrogen  carbonates  in  the  sea  being  low,  the 
proportion  of  carbon  dioxide  in  the  air  is  below 
DormaL    Samples  of  air  collected  over  the  sea  at 


latitudes  of  64-70,  at  temperatures  betwe^i 
1^  and  2°,  gave  a  mean  value  of  2*0524  voK  in 

Carbonic  acid  in  the  air  of  tropical  countries. 


T.  B.  Thorpe . 
Ml&nU  A  Aubbi 


S.  America 
S.  and  Oentral 
America 


1896 
1882 


0*0828  P.O. 
0*0278   „ 


Mean  0*0308 


10,000  of  air,  a  distinctly  smaller  proportion 
than  is  met  with  in  warmer  regions  (Muntz  and 
Laintf,  Gompt.  rend.  1011,  153,  1116). 

The  pressure  exerted  by  the  carbonic  acid  in 
air  is  so  small  that  its  amount  is  not  perceptibly 
diminished  by  rain.  The  amount  also  is  not 
sensibly  altered  in  the  higher  regions  of  the 
atmosphere. 

Of  the  several  methods  which  have  boon  pro- 
posed for  the  estimation  of  atmospherio  carbonio 
acid,  the  most  generally  convement  is  that  of 
Pettenkofer.  It  consists  in  exposing  a  known 
volume  (say  50  c.o.)  of  dilute  oaryta  water  of 
known  strength  to  a  measured  quantity  of  air 
(4-6  litres)  contained  in  a  weU-closed  flask.  In 
about  5  or  6  hours  the  absorption  of  the  car- 
bonio acid  will  be  complete,  provided  that  the 
sides  of  the  flask  have  been  moistened  from  time 
to  time  by  the  baryta  solution.  The  baryta 
solution  is  then  decaifted  and  allowed  to  stand 
in  a  small  stoppered  bottle  until  the  barium  car- 
bonate has  settled,  when  aliquot  portions  (say 
20  CO.)  of  the  clear  solution  are  withdrawn  and 
the  amount  of  the  baryta  still  in  solution  deters 
mined  by  titration  with  a  standard  solution  of 
sulphuric  or  hydrochloric  acid,  of  which  1  c.c.  «=  1 
mgm.  COf,  phenolthalein  being  used  as  indicator 
{v.  Aoidimxtbt).  The  difFerence  in  the  volume 
of  acid  needed  for  the  neutralisation  of  the  baryta 
before  and  after  exposure  to  the  confined 
volume  of  air  gives  the  number  of  milligrams  of 
carbonic  acid  contained  in  the  air.  Blochmann 
(Annalen,  237,  72)  has  described  a  modification 
of  the  apparatus  which  aUows  of  the  titration 
being  effected  without  exposure  to  the  air  of  the 
laboratory. 

(For  other  methods,  v.  Haldane  and  Pembroy, 
Roy.  Soa  Proo.  1889;  CL  Winkler,  Chem. 
Unter.  der  Industrieffase,  Freiberg,  1877  ;  Reisot, 
Chem.  Soc.  Trans.  90,  1144 ;  Mftntz  and  Aubin, 
Gompt.  rend.  92,  247.) 

(For  An^^  Smith's  minimetrio  method,  v. 
Air  and  Ram ;  compare  Lunge,  Dingl.  poly.  J. 
231,331.) 

(On  the  influence  of  the  sea  upon  the  amount 
of  atmospheric  carbonic  acid,  r.  Levy,  Ann.  Chim. 
Phvs.  [3J  34,  5;  Thorpe,  Ohem.  Soc  Trans. 
1867;  Schloesing,  Gompt.  rend,  93»  1410; 
Lawes,  Phil  Mag.  [5]  11,  206.) 

Minute  quantities  of  ammonia  and  nitrous 
and  nitric  aoids  are  also  present  in  the  air. 
Although  many  of  the  published  observations 
are  probably  maccurate  owing  to  the  imper- 
fection of  the  methods  emploved,  it  appears  to 
be  proved  that  the  amount  of  ammonia,  which 
exists  mainly  as  carbonate^  is  subject  to  very 
great  variations.  By  aspirating  from  10  to  20 
Iitra  of  air  through  Nesftler's  solution  (an  alka- 
line solution  of  potassium-mercury  iodide)  and 
comparing  the  depth  of  colour  with  that  pro- 
duced by  a  standard  solution  of  an  ammonium 
salt,  H.  T.  Brown  (Roy.  Soc.  Proc.   18.  286) 


428 


ATMOSPHERE. 


foand  th&t  the  air  of  Burton-on-Trcnt  during 
September,  October,  and  November,  1869, 
taken  2  metres  from  the  ground,  contained  from 
0-4059  to  0-8732  part  (NHJsCO,  in  100,000  parta 
of  air,  whereas  that  of  the  country  taken  during 
December  and  February  contained  from  0-51(^ 
to  0*0085  part.  The  direction  of  the  wind  had 
apparently  no  influence  on  the  amount ;  heavy 
rain  seemed  to  diminish  it,  but  the  air  wm 
restored  to  its  normal  condition  in  a  few  hours. 
Truchot  found  from  0*93  to  2*79  mgm.  per  cubic 
metro  in  the  air  of  Auvergne,  the  minimum 
being  found  in  clear  weather  and  the  maximum 
during  fqgs  (Compt.  rend.  77,  1059).  Mfinti 
and  Aiibin,  from  observations  on  rain  vrater, 
found  that  the  upper  starata  of  air  contain  much 
Ices  ammonia  than  air  near  the  ground.  Levy 
(Compt.  rend.  91,  94)  found  that  the  rain  water 
and  snow  of  Paris  contain  in  mean  1*17  cigm. 
of  ammoniacal  nitrogen  per  litre  of  water.  The 
amount  of  ammonia  in  this  meteoric  water  is 
least  in  winter  and  greatest  during  the  warrcer 
periods  of  the  year.  Gilbert  and  Lawes  found 
that  1,000,000  pts.  of  rain  water  collected  in  the 
countiy  contained  0*927  to  1*142  pts.  of  am- 
monia. Rain  water  collected  in  towns  always 
contains  large  quantities  of  ammonia.  Thus 
Angus  Smith  found  that  rain  water  collected  in 
the  sparsely  populated  districts  in  Scotland  con- 
tained 0*53  pt.  per  million,  whereas  the  rain 
water  of  London  contained  3*45,  that  of  Liver- 
pool 5*38,  that  of  Manchester  6*47,  and  that  of 
Glasgow  9*1  per  million.  The  increased  amotRit 
in  the  towns  is  doubtless  due  to  the  influence  of 
animal  life  and  to  the  constant  presence  in 
ffToater  proportion  than  in  the  country  of  readily 
decomposabh  nitr  senous  oraanic  matter  m 
the  air  (ij.  Heinricn,  Chem.  Soc.  Abst.  1898, 
ii.  114). 

The  quantities  of  nitrous  and  nitric  acids  in 
the  air  are  even  smaller  than  that  of  ammonia. 
Angus  Smith  (Air  and  Rain,  287)  has  given 
the  following  results  showing  the  amount  con- 
tained in  a  million  pts.  of  rain  water : — 

Scotland,  inland  country  places  •  0*306 

Ireland        „  „  ^     .  0*370 

Scotland,  country  places     .         .  0*424 

„        towns  .         .  1164 

England,  inland  country  places  .  0*749 

„        towns         .  0*863 

Trieschmann'found  that  the  average  per  million 
brought  down  in  rain  at  Mount  Veinon,  Iowa, 
over  a  period  of  %\  months  was  of  free  ammonia 
0*407 ;  albuminoid  ammonia,  0*366 ;  nitrates, 
0-255 ;  and  nitrates  0018.  Rain  was  found  to 
be  richer  in  nitrogen  contents  than  snow  (Chem. 
News,  1919,  119,  49). 

Occasionaily,  and  more  especially  in  the  air 
of  towns,  minute  quantities  of  hydrocarbons, 
iulphuretted  hydrogen,  carbonic  oxide, 
sulphurous  acid,  common  salt,  alkaline 
sulphates,  are  met  with.  Boracic  acid  and 
sal  ammoniac  have  been  observed  in  air  in 
the  neighbourhood  of  active  volcanos. 

The  percentage  amount  by  volume  of  the 
inert  gases  in  the  air  may  be  stated  as  follows  : — 
Argon  ....  0*93000  p.c. 
Krypton  .  .  .  0*00995  „ 
Xenon  ....  0*00114  „ 
Neon  ....  0*00123  „ 
Helium  .  .     0*00040    „ 


(Moissan,    Compt.    rend.    137,  600;    RamflAy» 
Etoy  Soc.  Proc.  1908,  80  A,  599.) 

Organic  matter  in  greater  or  less  quantity 
M  always  present  in  the  air.    Much  of  this  is 
nitrogenous,  and  hpparontly  readily  susoeptiblo 
to  putrefaction,  givmg  rise  to  products  which  arc 
alternately  transformed  into  ammonia,  nitrous 
and  nitric  adds.    This  form  of  oreanic  matter 
reduces  silver  nitrate  and  potassiflm  perman- 
ganate solutions.    A   portion   of   the   organic 
matter    consists    of     micro-organiBms    which 
are  rapidly  deposited  in  the  aroenoe  of  strong 
aSrial  currents.     Hesse  quantitatively  estimates 
the  relative  proportions  of  micro-organisms  con- 
tained in  air  by  aspirating  a  given  volume  of 
the  air  through  glass  tubes  coated  internally 
with  gelatine  peptone,  which  is  then  kept  at  a 
temperature  of  about  25*  for  some  days,  when 
the  various  monad  bacilli  and  micrococci  which 
are  arrested  and  which  are  capable  of  growing 
in  the  gelatine  peptone  are  recognised  by  the 
colonies  which  they  form.     By  means  of  this 
method    Percy    F.    Frankland    has    made    a 
number  of  estimations  of  the  mioro-crganisma 
contained  in  the  air  of  tonus  ni  d  in  the  country 
and  in  inhabited  buildings.     By  simultaneously 
exposing  small  circular  glass  dishes  partially 
filled  with  the  nutrient  gelatine  to  the  action 
of  the  air,  a  rough  estimate  was  obtained  not 
only  of  the  number  of  micro-organisms  in  a 
given  volume  of  the  air,  but  also  of  the  number 
which  fell  during  a  given  time  on  a  definite 
horizonted  area.    As  the  mean  of  a  series  of 
observations  made  on  the  roof  of  the  South 
Kensington  Museum  between  January  and  June, 
1886,  it  was  found  that  there  were  35  organisms 
in  10  litres  of  air,  whilst  279  was  the  average 
number  which  fell  on  1  sq.  ft.  in  1  minute. 
Similar  experiments  made  near  Reigate  and  in 
the  vicinity  of  Norwich  showed  an  average  of 
14  organisms  in  10  litres  of  air,  while  79  feU 
per  sq.  ft.  per  minute.    Experiments  made  in 
Eensinffton  Gardens,  Hyde  Park,  and  on  Prim- 
rose Hul,  gave  an  average  of  24  oiganisms  in 
10  litres,  and  a  deposition  of  85  per  sq.  ft.  per 
minute.    At  St.  Paul's  Cathedral,  56  organisms 
were  found  at  the  base,  29  in  the  Stone  Gallery, 
and  11  in  the  Golden  Gallery,  in  10  litres  of  air. 
At  Norwich  Cathedral,  18  at  the  base,  9  at  a  height 
of  180  ft.  and  7  at  300  ft    In  inhabited  build- 
ings great  variations  were  observed ;  as  a  rule, 
the  number  of  micro-or^^aniBms  was  less  than 
was  found  in  the  open  air  when  the  air  of  the 
room  was  undisturbed,  but  rose  rapidly  when  the 
air  was  set  in  motion  by  draughts  or  by  the 
presence  odP  many  people  (P.  F.  frankland,  Roy. 
Soc.  Proc.  40,  509). 

Experiments  made  at  the  Montsouris  Obser- 
vatory have  shown  that  far  fewer  organisms  are 
present  in  the  air  during  winter  wan  during 
spring  and  summer.  The  number  also  seemA  to 
be  greatly  increased  after  rain.  Whilst  in  the 
warm  months  the  number  of  spores  in  1  litre  of 
air  was  28,  after  heavy  rain  it  rose  to  95  and 
120. 

Atmospheric  dust  is  made  up  of  both  in- 
organic and  orsanic  matter,  lissandier  found 
that  1  cm  of  the  air  of  Paris  contained  <m  the 
average  7*5  mgms.  of  dust;  after  a  period  of 
dry  weather  (8  days),  23*0  mnns.,  and  after 
heavy  rain,  only  6*0  mgms.  It  consisted  of 
from  27  to  34  p.c.  volatile  matter,  and  from 


ATOMIC  WEIGHTS  AND  SYMBOI^. 


420 


6G  to  75  p.c.  mineral  matter,  viz.  sulphates 
and  chlorides  of  the  alkalis  and  alkaline  earthst 
oxides  of  iron,  earthy '  carbonates  and  phos- 
phates, Ac.  (r/.  J.  Aitkeo,  Trans.  Boy.  Soe. 
Edin.  35,  37,  39). 

RADIOACnVX  OoySTlTUKKTS  OF  THB  AtMO- 

SFHXBX. 

A  charged  electroscope  slowly  loses  its  charge 
in  air,  and  it  has  been  shown  that  this  is  not  due 
to  moisture,  but  that,  on  the  contrary,  the 
leakage  is  greater  in  dry  than  in  wet  weather. 
The  conductivity  of  air  is  lessened  by  passage 
through  a  metal  tube  or  by  the  presence  of  a 
weak  electric  field.  These  facts  indicate  that 
the  conductivity  of  air  is  due  to  the  presence 
of  charged  ions  (Townsend,  Proc.  Roy.  Soc. 
1899,  65,  192;  Geitel,  Naturw.  Bundsch.  21, 
221).  The  rate  of  leakage  of  electricity  from 
a  charged  conductor  in  dust-free  air  is  the  same 
for  positive  and  negative  charges,  but  varies 
^\'ith  the  pressure.  The  loss  of  charge  per  second 
corresponds  to  the  production  of  M>out  20  ions 
of  either  sign  in  each  cubic  centimetre  of  air 
(Wilson,  Proo.  Boy.  Soc  68,  151). 

ELster  and  Geitel  have  shown  (Wied.  Ann. 
[2]  39,  321)  that  ions  are  produced  durins 
the  formation  of  ozone  by  contact  of  air  with 
flames  or  by  the  slow  oxidation  of  phosphorus, 
&c,  but  the  mere  presence  of  ozone  does  not 
impart  conductivity  to  air  (Jorissen  and  Binger, 
Ber.  1906,  39,  2090).  Langevin  (Compt.  rend. 
1905,  140,  232)  states  that  in  air,  in  addition  to 
ordinary  ions  carrying  charees  equal  to  that  of  a 
hydrogen  ion  in  solution,  tnere  exist  other  ions 
having  a  much  smaller  mobility,  but  carrying 
charges  fifty  times  as  great. 

Nordmann  has  described  (Compt.  rend.  140, 
430)  an  apparatus  for  continuously  recording  the 
state  of  ionisation  of  the  air.  Air  is  caused  to 
circulate  between  the  plates  of  a  cylindrical 
condens^,  and  the  charge  given  up  by  the  ions 
is  removed  by  dropping  water.  The  condenser 
is  connected  with  an  electroscope,  the  deviations 
of  which  are  recorded  photographically,  and  are 
proportional  to  the  number  of  ions  present  in 
unit  volume  of  air.  Another  apparatus  for  the 
same  purpose  is  that  of  Langevin  and  Moulin 
(Compt.  rend.  140,  305). 

No  satisfactory  explanation  of  the  ionisation 
of  air  was  found  until  Elster  and  Geitel  showed 
(FhysikaL  Zeitsch.  1901, 76, 590)  that  a  negatively 
chiurged  wire  suspended  in  the  open  air  t)ec«me 
coated  with  radioactive  matter,  the  presence  of 
which  could  be  proved  by  its  action  upon  a 
charged  electroscope,  although  the  quantity 
present  was  altogeUier  too  small  to  respond  to 
any  chemical  test.  Butherford  ana  Allan 
confirmed  this  observation,  and  measured  the 
rate  of  decay  of  the  deposit  (Phil.  Mag.  1902, 
vi.  4,  704).  Later,  Allan  showed  that  the 
radioactive  matter  could  be  removed  from  the 
wire  by  rubbing  it  with  a  piece  of  felt  or  by 
solution  in  ammonia,  and  that  the  ashes  of  the 
felt  or  the  residue  from  the  evaporation  of  the 
solution  showed  radioactivity  having  a  period 
of  decay  equal  to  that  of  the  deposit  on  the 
wire  (PhiL  Mag.  1904,  vi.  7,  140). 

These  phenomena  are  due  to  the  presence 
in  the  atmosphere  of  the  gaseous  emanations 
of  radioactive  elements,  probably  those  of 
radium  and  thorium  (Bumstead,  Amer.  J.  Sci. 


1904,  18,  1).  The  amount  of  active  matter 
is  not  constant,  but  increases  with  increased 
circulation  of  the  air,  and  is  therefore  probably 
due  to  the  presence  of  radium  in  the  sod  (Simp- 
son, Phil.  Trans.  1905,  A,  205,  61).  Balloon 
observations  made  by  flemming  (Zeitsch. 
physikaL  Chem.  1908,  9,  801)  show  that  radium 
emanation  is  present  even  at  a  height  of  3000 
metres.  Thorium  emanation  exists  principally 
in  air  taken  from  the  soil  or  the  lower  layers 
of  the  atmosphere  (Gockel  and  Wulf,  PhysikaL 
Zeitsch.  1908,  9,  907).  That  it  is  not  widely 
disseminated  in  the  air  is  probably  due  to  its 
rapid  rate  of  decay  (Blanc,  Physikal.  Zeitsch.  . 
19US,  9,  294).  The  experiments  of  Dadourian 
(PhysikaL  Zeitsch.  1908,  9,  333)  and  of  Wilson 
(Phil.  Mag.  1909,  17,  321)  indicate  that  air 
normally  contains  about  3700  times  as  much 
radium  emanation  as  thorium  emanation. 

By  passing  air  through  a  copper  spiral  cooled 
in  liquid  air,  the  emanations  are  condensed,  and 
may  then  be  volatilised  into  an  electroscope  and 
the  amount  estimated  by  their  effect  in  ionising 
the  contained  air.  Ashman  (Amer.  J.  Sol 
1908,  26,  119)  has  thus  found  in  Chicago  air 
an  amount  of  emanation  per  cubic  metre  equal 
to  that  which  would  be  in  equilibrium  with 
about  1 -0x10'^*  gram  of  radium.  By  absorb- 
ing the  emanations  in  charcoal  and  then 
v(3atilising  them  into  an  electroscope.  Eve 
has  obtamed  results  of  the  same  order — 
0'8xlO~^*  gram  for  the  radium  equivalent  of 
the  emanation  in  the  air  of  Montreal  (Phil.  Mag. 
1907,  14,  724),  and  has  shown  by  numerous 
observations  that  the  value  i^  not  affected  by 
temperature,  but  that  a  deep  cyclone  with  rain 
causes  an  increase,  whilst  anti-cyclonic  conditions 
cause  a  decrease  in  the  amount  of  emanation 
(PhiL  Mag.  1908,  16,  622).  These  results  have 
been  confirmed  by  Satterly  (Phil.  Mag.  16»  584). 

All  investigators  are  agreed  that  these 
emanations  are  the  chief  cr  use  of  the  ionisation 
of  air,  but  Wilson,  by  experiments  on  the  effect 
of  pressure  on  *  natural '  ionisation  of  air  enolosed 
in  a  metal  cylinder,  has  shown  (Phil.  Mag.  1909, 

17,  216)  that  it  is  partly  due  to  some  pene- 
trating radiation  the  source  of  which  Is  not 
in  the  soil  (Pacini,  Atti  R.  Acad.  Lincei,  1909, 

18,  123).  Both  Pacini  and  Wulf  (Physikal. 
Zeitsch.  1909,  10,  152)  have  detected  a  double 
diurnal  periodicity  in  the  state  of  ionisation  of 
the  air. 

{8e€  also  Harvey  (PhysikaL  ZeitsoL  1909, 
10,  46)  and  Bunge  (Chem.  Soc.  Abstr.  1908,  ii 
80).) 

ATOMIC  WEIGHTS  AND  SYMBOLB  OF  THB 
ELEMENTS  (0==  16). 

Aluminium       .         .        •         .  Al      27*1 

Antimony         .        .         •         •  Sb  120*2 

Aigon A        39*9 

Arsenic    .         •         .         .         .As      74'96 

Barium Ba  137*37 

Bismuth Bi  208O 

Boron B        10-9 

Bromine Br      79-92 

Cadmium  .         .         .         .  Cd  112^0 

Cssium Cs  132*81 

Calcium Ca      40-07 

Carbon C         12-005 

Cerium Ce  140  25 

Chlorine CI       35*46 


430 


ATOMIC  WEIGHTS  AND  SYMBOLS. 


Ghiomiom        • 

Cr 

52-0 

Cobalt     . 

Co 

58-97 

Goluinbiam 

Cb 

931 

Copper     • 

Cu 

63-67 

I^sprosium 

Dy 

162-5 

Erbium    . 

Er 

167-7 

Europium 

Eu 

1620 

Fluorinn  • 

P 

19-0 

Qadolinium 

Gd 

167-3 

QaUinm 

Ga 

701 

Germanium 

Ge 

72-5 

Glucinum 

Gl 

91 

Gold 

Au 

197-2 

Helium    • 

He 

4-00 

Holmium 

,    Ho 

163-5 

Hydrogen 

H 

1-008 

Indium    . 

In 

114*8 

Iodine 

.    I 

126-92 

Iridium    • 

.     Ir 

1931 

Iron 

.     Fe 

66-84 

Krypton  . 

Kr 

82-92 

lanthanum 

La 

139-0 

Lead 

Pb 

207-20 

Lithium  . 

.     Li 

6-94 

Lutecium 

.     Lu 

ireo 

Magnesium 

.     Mg 

24-32 

Manganeee 

.     Mn 

64-93 

MerouiT  . 
Molybdenum 

.     Hg 

200-6 

.     Mo 

960 

Neodymium 

.     Nd 

144-3 

Neon 

.     Ne 

20-2 

Nicxel      . 

.     Ni 

68-68 

Niton      . 

.    Nt 

222-4 

Nitrogen  • 

.    N 

14-008 

Osmium  . 

.    Os 

190-9 

Oi^gen    . 
Palladium 

.     0 
.    Pd 

1600 
106-7 

Phosphorus 

.    P 

31-04 

Platkium 

.    Pt 

195-2 

Potassium 

.     K 

39*10 

Praseodymium 

•  • 

.     Pr 

140*9 

Radium  • 

.    Ra 

2260 

Rhodium 

.     Rh 

102O 

Rubidium 

.     Rb 

86-45 

Ruthenium 

.     Ru 

101-7 

Samarium 

.    Sa 

160-4 

Scandium 

.     Sc 

44-1 

Selenium 

.     Se 

79-2 

Silicon     . 

.     Si 

28-3 

Silyer 

.     Ag 

107-88 

Sodium    • 

.     Na 

23-00 

Strontium 

.     Sr 

87-63 

Sulphur   • 

.     S 

32-06 

Tantalum 

.    Ta 

181-6 

Tellurium 

.    Te 

127-5 

Terbium 

.    Tb 

169-2 

Thallium 

.    Tl 

204O 

Thorium 

.     Th 

232-15 

Thulium 

.     Tm 

168-5 

Tin 

.    Sn 

118-7 

Titanium 

.    Ti 

48-1 

Tungsten 

.    W 

1840 

Uranium  • 

.     U 

238-2 

Vanadium 

.    V 

510 

Xenon     • 

.     Xe 

130-2 

Ytterbium  (Nee 

>vtterl 

)ium) 

.    Yb 

173-5 

Yttrium  0 

.     Yt 

89-33 

Zinc 

.     Zn 

65-37 

Zirconium 

.     Zr 

90-6 

ATOPHAN.    Trade     name     for     S 

^-phenyl- 

quinoiine-4-carl 

)ozyli 

0  add 

I. 

COOH 


U\/-C'H» 


Used  as  a  uric  acid  eliminant  and  as  an  analgesic 
in  the  treatment  of  gout  and  sciatica. 

ATOXYL.  Trade  name  for  the  mono-sodium 
salt  of  p-aminophenykiFBinio  acid  (EhrUch 
and  Bertheim).  Forms  a  white  ciystalline  taste- 
less, odourless  po\rder.  So  named  from  its 
relatiyely  low  toxic  action  (v.  Absbnigals, 
OsQAmo.) 

ATRAMENTUM  STONE.  (Atrameniymatin, 
Ger.)  A  product  of  the  partial  oxidation 
of  iron  pyrites,  consisting  of  a  mixture  of  ferrous 
and  ferric  sulphates  with  free  ferric  oxide.  Used 
in  tiie  manunu^ture  of  ink. 

ATBANORIN  Ci^i«0,  is  present  in  the 
lichens  Evemia  vtdpina,  E,  prunaHri,  E.  fur- 
furaeeap  Lecanora  aira,  L,  aordida,  Parmelia 
perlaUit  P.  phy8odes,  P.  Undoriumf  Physda 
steUaris,  Xanihoria  parietina,  Cladonia  rangi- 
formiSf  Stereoeatdan  vesuvianum  and  others, 
it  forms  colourless  prisms,  m.p.  195^-197^  C. 
(Zopf),  18r*-188''  C.  (Hesse),  easily  soluble  in 
hot  chloroform,  soluble  in  alkalis  with  a  yellow 
colour. 

According  to  Patemd,  by  heating  with  wat^r 
to  160®,  atranorin  gives  physdol  (methyl- 
phloroglucinol)  and  atraric  acid  (betorcinol- 
carboxylic  add  methyl  ester),  and  these  sub- 
stances are  also  obtained  when  atranorin  is 
heated  with  acetic  acid  in  a  sealed  tube  (Hesse). 

PhyMUjl  forms  qolouriess  needles,  m.p. 
104^-105^  gives  a  blue-green  colouration  with 
ferric  chloride,  and  possesses,  according  to 
Hesse,  the  constitution  of  a  methyl-pMoro- 
gluoinol — 

CH, 


HO— 


Bdorcinol  earboxyUc  add  meihyl  tsier 
C10H1JO4,  crystalUses  in  leaflets,  m.p.  140®- 
141®  C.,  and  gives  a  blood-red  colouration  with 
calcium  hypochlorite  solution.  Digested  with 
boiling  hyoriodic  acid,  it  is  converted  into 
fi'Ordn  (Stenhouse  and  Groves),  C^HioOs, 
according  to  the  equation — 

Cija„044-HI-CH,I+CO,+C.HioO. 

fi-ordn  {we  also  barhatic  acid)  is  1 : 4-dimethyl- 
resorcinoL 

The  constitution  assigned  to  betorcinol 
carboxylic  acid  methyl  ester  is — 

CH, 

OCOOCIT, 
OH 
CH, 

Heated  with  alcohol  in  a  sealed  tube,  atranorin 
gives,  according  to  Patem6,  hatnuUommic  add 
and  hcBmatomminic  add ;  but  the  researches 
of  Hesse   indicate   that  these   compounds  in 


AURAMINE. 


431 


reality  conaist  of  hmmaiommic  add  meihyl  eiher 
and  betorcinol  carboxylic  acid  methyl  eiher, 

HamaUmmiG  acid  methyl  ether  CioHioOi 
forms  colourless  needles,  m.p.  147®,  soluble  in 
alkaline  solutions  with  a  yellow  oolour.  With 
ferric  chloride  it  gives  a  purple-red  or  purple- 
brown  oolouratjpn.  The  ethyl  eiher,  CnHnO,, 
Rives  colourless  needles,  melts  at  lll'*-112' 
(Hewe);  USM14®  (Zopf).  It  is  represented  by 
the  formula — 


When  a  solution  of  atranorin  in  dilute  aoetie 
acid  is  gently  evaporated*  alranorinie  acid 
(Hesae)  is  produced.  This  compound  is  also 
present  in  the  Cladonia  rangijormia  (Hesse) 
when  gathered  in  Deceibber,  but  is  absent  from 
the  lichen  in  summer. 

Atranoriwic  add  Cx,HigO,,H,0  forms 
colourless  dvstals,  which  are  anhydrous  at 
lOO"*,  and  then  melt  at  157^  With  ferric 
chloride  it  ^ives  a  dark  brownish-red  colouration. 
With  hydnodic  acid  it  gives  fi-ordn,  and  when 
heated  with  alcohol  vields  carbon  dioxide, 
phywM  and  fi-ordn.  The  constitutions  aesignod 
to  atranorinio  acid  (1)  and  atranorin  itself  (2)  are 
as  follows : — 


GH, 

0-^OOH 
--0-CH, 

CH,  0 

CH./N 


CH, 

0-^OOCH, 
— 0--C'H, 

CH,  0 


OH 
COOH 


I. 


Befereneea. — ^Patem6  and  Ogllalaro 
(Gaszetta,  7,  289),  Patem6  {ibid.,  10  ,  157.  and 
12,  257);  Zopf  (Annalen,  288,  38);  Hesse 
(J.  pr.  Chem.  57,  280) ;  Ludecke  (Annalen,  288, 
42);  HeMe  (Annalen,  119,  365) ;  Stenhouse  and 
Groves  (Annalen,  203,  302);  Hesse  (J.  pr. 
Ghemj  1906,  [il]  73,  113).  A.  G.  P. 

ATRINAL.  Trade  name  for  atropine  sul- 
phuric acid. 

ATROLACTIIIIC  ACID  v.  L^ono  acid. 

ATROPAinilB.    Set  under  Tbopeiuxb. 

ATROPINE  V,  Tbofxines. 

ATBOSCINB.     8u  Htoscins,  under  Tbo- 


ATTAR  OF  ROSBS  v.  Oils,  Essxntial. 

ATTR06TL.  vyn.  for  AsyphiL 

AUCUBIN  V.  6LU0O8IDX8. 

AURAMINE*  IminoietramethMiparamino-di- 
pkenylmethaM  hydrochloride,  C|fH.,N„Ha,H.O, 
indb,<5^4C(NH)<VH4OTleg,HCl,H,0(0^ 
or  MeJN-C^4<3(NH.)  i  CgH^ :  NMe,Cl,H,0 
(Stock;  Dlmroth  and  Zoeppritz).  According 
to  Stock  (J.  pr.  Chem.  47,  401 ;  Ber.  1900, 
33,  318),  and  Dimroth  and  Zoeppritz  (Bcr.  1902, 
35,  984),  the  base  has  the  constitution  assigned 
to  it  by  Graebe  (Ber.  1899,  32,  1078 ;  1902,  35. 


2616),  but  the  hydrochloride  and  the  other  salts 
have  the  quinonoid structure Me,N-C^4-C(NHg). 
CfH^ :  NMoiCl,  and  are  to  be  regarded  as 
derivatives  of  triphenylmethane  in  which  an 
amino-  group  ha?  replaced  one  of  the  benxena 
residues.  (C/.  Semper,  Annalen,  1911,  381, 
234.; 

Auramine,  the  first  member  of  a  series  of 
yellow,  orange-yellow,  or  brown  dyes,  is  the 
nydioohloride  of  a  colourless  base  obtained  by 
the  action  of  ammonia  on  tetramethyldiamino- 
benzophenone,  and  comes  into  the  market  either 
in  the  nearly  pure  form  as  Auramine  0,  or  mixed 
with  dextrin  as  Auramine  L  and  //.  (Graebe, 
Ber.  20,  3264).  Fehrmann  (Ber.  20,  2847)  pro- 
posed  to  restrict  the  name  auramine  to  the 
colourless  base,  but  such  a  change  would  inevit- 
ably lead  to  confusion ;  and  Graebe  ({.c.)  has 
consequently  adopted  the  name  auramine-lnue 
for  the  base  itself,  using  the  term  auramine  in 
its  usual  signification. 

PreparotHm.— ( 1 )  Auramine  was  originally  pre- 
pared from  tetramethyldiaminobenzophenone 
by  dissolving  it  in  some  indifferent  solvent  such 
as  chloroform,  carbon  disulphide,  hydrocarbons, 
&C.,  treating  it  with  halt  its  weight  of  nhos- 
phorus  trichloride  or  oxychloride,  and  aadinff 
excess  of  concentrated  ammonia  to  the  chlori- 
nated compound  thus  obtained  (B.  A.  S.  F.» 
D.  R.  P.  27789).. 

(2)  Auramine  can  be  prepared  more  econo- 
mically by  heating  tetramethyldiaminobenio- 
phenone  with  suitable  ammonium  salts,  such 
as  the  chloride,  acetate,  tartrate,  thiocyanate, 
&c.;  in  the  presence  of  sine  chloride  at  2Wf 
(B.  A.  S.  F.,  D.  B.  P.  29060).  Acetamide 
may  be  employed  instead  of  ammonium  salts 
(B.  A.  a  F.,  D.  R.  P.  38433),  or  the  dye  may 
be  obtained  by  heating  aniUne  hydrochloride 
with  sine  chloride  and  carbamide,  phenylcar- 
bamide,  diphenyloarbamide,  or  carbanil  (Ewer 
and  Pick,  D.  R.  P.  31936) ;  but  these  alterna- 
tive methods  have  no  practical  Importsaoe. 

(3)  At  the  present  day,  auramine  is  pre- 
pared by  a  method  due  to  Sandmeyer  (&ig. 
Pat  12549,  1889;  16666,  1890)  and  Walker 
(J.  Soc  Ghem.  Ind.  1901,  34),  which  consists 
in  heating  a  mixture  of  tetnkmethyldiamino- 
diphenvlmethane,  sulphur,  ammonium  chloride, 
and  sodium  chloride  in  a  current  of  dry  ammonia. 
A  modification  of  this  method  is  described  by 
J.  Y.  Johnson  (B.  A.  S.  F.,  D.  R.  P.  71320; 
Eng.  Pat.  6240,  Maroh  23,  1893),  in  which  the 
tetramethyldiaminodiphenylmethane  is  replaced 
by  dimethyl  •  tetramethyldiaminodiphenylme- 
thane  obtained  by  condcmsing  acetone  and 
dimethylaniline  (Ber.  1878, 12,  813).  About  14 
kilos,  of  dimeth^l-tetramethyldiaminodiphenyl- 
methane  are  nuxed  with  12Q  kilos,  of  salt,  6 
kilos,  of  sulphur,  and  7  kilos,  of  ammonium 
chloride,  and  a  stream  of  ammonia  gas  is  passed 
tlirough  the  mixture  for  eisht  hours  at  175*. 
The  mass  is  first  washed  with  cold  water  to  dis- 
solve away  the  salt  and  ammonium  chloride, 
it  is  then  dissolved  in  water  at  70*,  filtered, 
and  the  dye  salted  out,  pressed,  and  dried. 
Auramine  is  also  prepared  by  heating  dimeth^l- 
aminobenzamide  ana  dimethylaniline  with  zmo 
chloride  at  160*-200*  (D.  R.  P.  77329). 

(4)  Guyot  (Compt.  rend.  1907,  144,  1219 ; 
J.  Soc.  Chem.  Ind.  1908,  679)  has  r^thesised 
aura  mines    by    means    of    the    oxalic    esters. 


432 


AURAMINE. 


Tetraalkyldiaminodiplienylglyoollic  esters  ( J.Soc. 
Chem.  Ind.  1907»  603)  form  neutral  salts  with 
aoids,  the  indigo-blue  aqueous  solutions  of  whioh 
react  with  ammonia  even  when  dilute  to  furnish 
tetraalkyldiaminodiphenylamino  acetio  esters, 
according  to  the  equation  : 

(R,N-C,H4),0C1<X),R'+2NH, 

=NH4a+(R8N-C,HJ,C(NH,)(X),R'. 

These  new  compounds  are  «ro-carbozylio  deriva- 
tives of  the  leuoaiiramines,  and  possess  all  the 
properties  of  the  latter.  They  dissolve  in 
glacial  acetic  acid  with  an  intense  blue  coloura- 
tion, and  condense  with  aromatic  tertiary  amines 
to  form  triphenylmethane  derivatives.  Thus 
ethylhexamethyltriaminotriphenvl  acetate  is 
produced  by  heating  an  equimolecular  mixture 
of  dimethylaniline  and  ethyltetramethyl- 
diaminodiphenylaminoacetate  in  glacial  acetic 
acid  on  the  water-bath  for  some  miiiutes : 

(Mo,N-C.H4),C(00,Et)NH,+C,H.NMe, 

-(Me,N-C,HJ,C(C0,Et)C,H4NMe,+NH,. 

When  a  dilute  alkaline  solution  of  the  amino- 
acetio  ester  is  oxidised  with  dilute  potassium 
f erricyanide  solution  in  the  cold,  a  quantitative 
yidd  oi  the  corresponding  anramine  is  produced. 

Properties. — Auramine  orystallisee  from 
water  in  yellow  scales,  which  seem  to  consist  of 
six-sided  tables,  and  from  alcohol  in  solden- 
yellow  scales,  melts  at  267*  (Qraebe),  caroonises 
at  266*-280*  without  previous  fusion  (Fehrmann), 
and  is  sparingly  soluble  in  cold  but  readily 
soluble  in  hot  water;  the  temperature  of  the 
aqueous  solution,  however,  must  not  exceed  60*- 
70*,  otherwise  decomposition  ensues,  with  the 
formation  of  ammonia  and  tetramethyldiamino- 
benzophenone.  On  treatment  with  mineral  acids, 
the  aqueous  solution  undergoes  a  similar  decom- 
position either  slo'vdy  in  the  cold  or  very  rapidly 
on  heating.  Spectroscopically,  auramine  be- 
haves like  most  yellow  dyes ;  a  hot  concentrated 
aqueous  solution,  however,  shows  two  bands, 
one  in  the  red  and  one  in  the  green,  which 
become  broader  on  dilution  and  finally  coalesce, 
forming  a  bright  broad  band  extending  from  the 
middle  of  the  red  to  the  commencement  of  the 
green  (Qraebe).  On  treatment  in  the  cold  with 
ammonia,  auramine  (orvBtallised  from  alcohol) 
is  converted  into  the  colourless  base  Gx^HaiN,, 
which  melts  at  136*,  and  is  characterised  by 
yielding  with  acids  intensely  yellow,  and  for  the 
most  part  crystalline  salts,  which  dissolve  in 
water  and  alcohol  without  fluorescence.  Alka- 
line reducing  agents,  such  as  sodium  amalgam, 
slowly  deccSourise  the  alcoholic  solution  of 
auramine,  forming  Uucawramint  OitH|.N„  a 
colourless  crystaUme  reduction  compound  melt- 
ing at  135*,  which  dissolves  in  acetic  acid  with 
an  intense  blue  colour  owing  to  its  decompo- 
sition into  ammonia  and  tetramethyldiamino- 
benzhydrol. 

Auramine  dyos  wool  and  silk  direct,  pro- 
ducing colours  which  are  pore  ydlow  and  fairly 
fast  to  light  and  soap.  Cotton,  for  which  the 
dye  is  chiefly  used,  requires  to  be  first  mordanted 
with  tannin  and  tartar  emetic,  and  on  this 
account  auramine  is  useful  for  producing  com- 
pound shades  with  other  basic  colouring  matters, 
such  as  safranine,  benzaldehyde-green,  &c., 
which  are  fixed  by  the  same  mordant.  (For 
further  information  v.  Koohlin,  Wagner*s  Jahr. 
1834,  1139.) 


Salts.  Auramine  hydrochloride  Ci^H,iN, 
HC3,  is  sparingly  soluble  in  water^  and  has  fin 
90*4  at  25*  ;  the  palmitate  Oi7H,iN,,C,,U,tOt, 
has  m.p.  57*,  the  sUaraie  has  m.p.  68*  (Gnehm, 
Roteli  Zeit.  Angew.  Chom.  1898, 487) ;  the  meth^ 
sulphate  obtained  by  the  action  of  dimethyl 
sulphate  on  auramine,  has  m.p.  225*  (Zohlon,  J. 
pr.  Chem.  1902,  66,  [20]  387). 

Snbstttated  Aoramlnes.  In  addition  to 
auramine,  substituted  auramines  have  also  been 
prepared.  Auramine  G»  obtained  by  treating  a 
hot  mixture  of  sym-dimothvldiamino-di-o-toiyl- 
methane  (from  methyl  o-tdluidine  and  formal- 
dehyde) sulphur,  ammonium  chloride  and  salt 
with  dry  ammonia  gas  (Gnehm  and  Wright,  U.S. 
Pat.  488430),  has  m.p.  120*,  the  ptcrote  nas  m.p. 
234*,  the  sulphate  m.p.  182*,  the  oxalate  m.p. 
210*.    Leucauramtne  O  has  m.p.  208*. 

Metaiybrlauramine  can  be  obtained  bv  heat- 
ing an  intimate  mixture  of  10  kilos,  of  tetra- 
methyldiaminobensophenone  and  23  kiloa.  of 
metaxylidine  hydrochloride  for  about  4  hours 
at  200*  in  an  enamelled  vessel  provided  with  a 
mechanical  stirrer.  Fusion  takes  place  slowly, 
and  the  mass  hecomes  reddish  yellow  in  colour, 
assuming  finally  a  greenish  metallio  lustre  towards 
the  close  of  the  reaction,  which  is  complete  when 
a  test  roecimen  is  almost  entirely  soluble  in 
water.  The  cooled  mass  is  extracted  with  hot 
water,  and  the  dye  precipitated  in  orange-yellow 
flocks  by  addition  of  sodium  nitrate  to  tiie 
filtered  solution. 

Methylaaramlne  MeN :  C(C«H4*NHe,)t»  m-p- 
133*  (Zohlen,  J.  pr.  Chem.  1902,  66,  387),  the 
hydrochloride  Oi.U,«N,Cl,  has  m.p.  225*,  the  p2a- 
tinichhride  (OijH,4N,Cl),Pta^  m.p.  190*-200*, 
the  hydrcbromtde  0.gHs«NaBr,  m.p.  260*,  the 
hydriodide  Ci,H,4N,l,  m.p.  259*,  forms  a  series 
of  unstable  polyiodides:  the  trichromate 
(C,,H,.N,).0,Oio,  m.p.  70*,  the  ihiocyanaU 
OxaH,«N,CNS,  m.p.  213*-214*,  and  the  picraU 
OigH„N„C,H,0^^,  m.p.  225*. 

Effiylauramlne  JBtN :  C(CcH4'NMe,)g,  from 
auramine  ethyl  iodide  and  zinc  oxide  (D.  R.  P. 
136616),  m.p.  130*-131*,  dyes  mordanted  cotton 
a  pure  yellow. 

PheoylaiiramllM  PhN :  C(C,H4-NMe,)t,  pre- 
pared by  heating  tetramethyldiaminodijuienyl* 
methane  with  aniline  and  sulphur  at  200*  (Feer, 
D.  R.  P.  53614) ;  or  bv  heating  dimethylainino- 
benzanilide  with  dimethylaniline  and  phosphorus 
oxychloride  (D.  R.  P.  44077);  has  m.p.  172*; 
the  hydriodide  C,3H,.N„HI,  has  m.p.  242* ;  the 
methiodide  CttH,,Nt,MeI,  has  m.p.  214*. 

Paraminophenylauraiiiine  NH,  •  C^HaN  : 
C(CeH4*NMe,)t  (^ckh  and  Sohwimmer,  J.  pr. 
Chem.  1894,  50,  401),  has  m.p.  221*-222* ;  the 
hydrochloride,  m.p.  224* ;  the  picratef  m.p.  185*- 
186*  (coiT. ) ;  the  aiaeeiul  derivative  has  m.p.  194*- 
195*;  the  triacetyl  derivative  has  m.p.  257*- 
258*  ;  monobenzoyl  denveXiye  has  m.p.  117°:  ana 
the  itbeiuQyJ  derivative  has  m.£.  180*-181*: 
paraphenyJenediauramine  G4H  JN  :  C(C4H4' 

NMcj),!,,  has  m.p.  311*-312*. 

Orthamlnopheiiylaaraiiiine,  m.p.  199*-200*, 
forms  a  picraie,  m.p.  220*-221*,  and  a  heiaaoyl 
derivative,  nup.  236*-237*;  OfiAopA€i^2eiie- 
diauramine  has  m.p.  305*. 

p-Tolylanramine,  obtained  by  heating  te- 
tramethyldiaminodiphenylmethane  with  p- 
toluidine  and  sulphur  (D.  R.  P.  53614),  or  from 
dimethylaminobenzo  -  p  •  toluidine,     dimethyl- 


Miiliiie,  Mid  phoaphonu  oiyoMorid«  (D.  R.  P. 
44077),  hum.p.  178*.  o-TolylsnmninB  similHrl? 

prepared  to  the  p.  oompoundhMm.p.  173'-174*, 
a  -  Biphthjlauramlne  [Me.N-C.H.lc  t  IfC,,H, 
(D.  R.  P.  44077),  luu  m.p.  225'.  fl-n»pM6yl- 
AOnuiiliH  (M8,N-C,H4),C :  N-C,jH,  (D.  B.  P. 
41077).  m-p.  179*  -  ISO*.  BeQzylaDnmlna 
C.H.-CH.-N :  C(C^,-NMe,}^  (D.  R.  P.  138816) 
fram  aurammB  benzylahlonde  &nd  magnesia, 
ha*  ni.p.  116*.  BeiUOjIaiiraillln*  {Finckh  and 
Schinmrner,  J.  pr.  Chem.  1S94,  50,  401]  NBi : 
C(G,H,-NMe,)^  has  m-p.  17B*  (oorr.). 

MMytphenslanramint  hydroMoriile,  de- 
phenylavramiiu,  and  penlaTiKthulnKavramiiM 
Kavebeen  described  by  Stock  (Ber.  1900,33,313; 
J.  pr.  CSiom.  47,  401-413).  The  following  oom- 
pouttda,  cloaelv  related  to  the  mmhthjlauraiDinei, 
form  the  tobjeot  of  a  patent  (D.  R.  P.  44077) ; 
Ulraethyldiamiiiadiphetiyltiuihyltne  -  ■  -  naphihyl- 


n-naphlhylamint  [Mo.N-C.HJ  (Et,N-C,Hj)C  ;  N- 
Cj,H_  m.p.  m'-ns' ;  taraethyidiaminodi- 
Jiatylmilhyltnt-P-naphthylamine  (Et,N-C,Hf  ),C: 
N-C,^7,  m.p.  1C&° ;  dimethyldietkyldiamiiwdi- 
phenyl7neihykae-P-7iapMhylamiat  (Me,N-C,H,] 
(Et,B-C,H,)0:N-C,^,  m.p.  leS'-lM". 

ThB  mbatitnted  aarainiaM  dve  silk  and 
irool,  and  also  cotton  aftei  mordanting  with 
tannin.  The  ahadea  produoed  on  cotton  are, 
however,  distinctly  reddish  or  biowniah-yellow 
compared  with  the  pure  yellow  produoed  by 
aUTMnine  itaelf ;  for  example,  the  auramines 
from  orthot«luidine,  metaxylidine  and  cumi- 
dine  hydrochloridM  dye  cotton  golden-yellow ; 
those  from  aniline  and  poratoluiduie  dye  orange- 
red,  that  from  metaphenylenediamine  dyea 
orange-brown,  and  those  from  a-  and  ^-naphtbrl- 
arnine  dye  browniah-yellow  shades  (B.  A.  S.  F., 
D.  R.  P.  29080 ;  Fehrmann,  Ber.  20,  2B52). 

ADBAMTIA  {Kaueyea)  is  the  commercial 
name  of  the  amnoiuum  salt  ol  hezanitro- 
diphenylamine. 

Htxmtarodiphenylamine  NH[;C,H,(NO,),],  is 
obtained  by  ttenting  diphenyUmiae  or  methyldi- 
phonylamine  with  nitric  acid,  and,  after  the  Grat 
vigorous  action  has  subsided,  heating  to  com- 
pute the  leaotion.  The  product  is  then  ex- 
tracted with  water  to  remove  any  resin  or  piorio 
acid  aaaociated  with  it,  and  Snally  crysMliaed 
from  acetio  add. 

It  forms  bright-yellow  prisms,  melts  at  238* 
with  decomposition,  but  can  be  sublimed  in 
jrallow  needles  by  osVeful  heating,  and  is  almost 
insoluble  in  water,  more  soluble  in  alcohol,  and 
easily  solnble  in  ethor.  It  readily  yields  salts, 
and  the  ammoni'tini  salt  (aurantia)  cryBtallises 
in  lustrous  brown- red  needles,  although  com- 
mercially it  is  obtained  as  a  brick-red  powder 
which  dissolvea  in  water  and  dyea  silk  and  wool 
a  beautiful  orange  colour  (Gcehm,  Brr.  7.  1399 ; 
g.  124fi;  cf.  Townsend,  Ber.  7,  124S  ;  Mcrtena, 
B^.  11,  840).  Aurantia  is  used  chieSy  as  a  dya 
for  leather  (W.  J.  1877,  1002).  Like  heianitro- 
diphenylamine ,  it  is  very  explosive,  but  any 
danger  may  be  avoided  by  moistening  it  with 

gyeerol  (W.  J.  1878,  998).  Acconling  to 
nehm  (Ber.  9,  1248,  1557)  and  Bayer  £  Co. 
(W.  J.  1S77,  879),  aurantia  produoes  skin 
eruptions ;  Martins,  however,  contends  that 
this  effect  is  dne  to  idiosyncrasy,  and  quotes  the 
opinions  of  Salkowski  and  Ziureck  in  support 
TOU  I.— y 


■LAVE.  433 

of  his  statement  (Ber.  9,  lft7),and  the  qnestion 
appear*  to  iiave  teoeived  a  solution  in  this  sense 
in  Qsrmany,  since  the  ministerial  order  ol 
NoTember  6,  1377,  prohibiting  its  manuFootun, 
WM  cancelled  in  June,  18S0. 

ADRIN  and  ROSOUC  ACID  v.  Tufbbnvl. 

UITHUia  OOLOTTBOra  1UTTXB3. 

AUROCANTAN.  Cantharidylethylenedia- 
mine  aurocyiuiide. 

AUROCHIH.    Quinine  j)-aminobenzoflt«. 

AURUH  HUSnrUH  or  HDSAIGUM.  Jfomic 
]M.  Hade  by  triturating  an  amalgam  of  2 
parte  tin  and  1  of  meroury  with  1  part  lal 
ammoDiao  and  1  of  sulphur,  and  snbseauently 
subliming.  Used  as  a  broniing  powder  for 
plaster  fiauies  (if.  Bbonu  roWDSBS). 

ADSTENITE.  A  solid  solution  of  carbon  in 
iron,  of  variable  composition ;  is  a  constant 
constituent  of  steels  containing  1-1  p.o.  of  carbon 
or  more  when  cooled  rapidly  nom  a  temperature 
of  IIOC-ISOO'.  It  ma^^  be  obtained  pure 
by  quenching  a  steel  containing  0'93  p.o.  carbon 
and  1-67  p.c.  manganese  from  1050°  in  ice- 
water  (Maurar,  M^t^urgie.  1909,  0, 33).  Steels 
containing  13  p.o.  of  manganese  or  2G  p.o.  of 


nickel  ci 


n  only  auitenite,  and  are  soft  and 

Under  the  microscope  aasteoite  is  recognised 
by  its  softness  as  compared  with  '  marlentiU,' 
with  which  it  is  usually  associated ;  by  its 
atructureless  appearance  and  by  the  brightness 
at  an  etched,  polished  section  (Le  Chatelier, 
Rovuo  da  Metallurgie,  1904). 

AUSTRALENE  v.  Timpumra. 

AOSTIUAN  CINNABAR.  Bona  Uad  dtrc 
matt  (u.  (^ooiAuii). 

AUTAN.  A  mixture  of  solid  (polymerised) 
Formaldehyde  and  the  dioxides  ol  barium  or 
strontium,  used  in  the  disinfection  of  living- 
rooms.  On  miiing  the  powder  wiUi  wat«r,  a  . 
rapid  disengagement  of  formaldehyde  vapour, 
mixed  with  oxygen,  ocouis. 

AUTOCLAVE.    An  appamtus  oonstmcted  on 
the  principle  of  Pepin's  digester,  for  heating 
liquids   at   temperatures   above   their   boiUng- 
points.     Autoclaves  are  usually  made  of  cast- 
iron  or  Btoel,  occasionally  of  copper,  and  in  some 
cases   of   sboet-iron  or   steeL    Cast-iron   auto- 
claves   are    sometimes 
strapped  with  steel  rings 
for     greater     security. 
Tboy  are  often  enamel- 
led or  lined  with  sheet- 
tin,  lead,  copper,  or  zinc. 
MetaUic  Uninga  are  now  ! 
soldered  rigidly  to  the  | 
surface  of  the  autoclave.  ' 
Tboy  are  atted  with  a 
pressuro      gauge      and 
safety  valve,  and  tubes 
for  the  insertion  of  ther- 


usually    closed     by 
screw    or    flanged       - 
washer   of   load. 


Fio.  L 


..— .  working  against  a 
minium  or  copper,  and 
by  steam,  direct  fire, 
electrical  heaters,  the  cireulation  of  hot  oU. 
or  in  a  bath  of  molt«n  lead.  Tbey  are  tested 
before  use  at  (at  least)  twice  their  working 
pressure  by  means  of  a  hydraulic  test  pump. 
OceasionaUy  they  are  provided  with  agitators 
working   through   stuffing   boxes,   in   unler   to 


f  thorough  mixing  o£  the  cooients  when 


AUTOCLAVE. 

eDzymcB,  and   are   soalaaouB   to   tioie   wliloh 
inxMT  in  digestion  i  indeed  the  term  »uto-ilig««- 
tion  ie  sometimes  employed.    The  itudy  of  snoh 
changes  is  important  be- 
cause it  is  belieTeil  that 
the   change  atter  death, 
when   the  celts   "       "''" 


Fio   2.  Fia.  3. 

Figs  I,  2  and  3  illustrate  the  types  of 
apparatus  for  pressures  of  20  or  30  atmospheres, 
but  when  very  high  pressures  are  employed 
(too  atmoi.  or  more]  a  tubular  design,  Fig.  4, 
is  more  satisfactory  both  in  coat  and  ease  of 
manipulation.  Autoclaves  working  at  about 
10  atmos.  are  usually  of  metted  steel  plates, 
and  loUow  ordinary  steam  boiler  practice. 
Welding  is  not  as  reliable  as  rivetting,  and  must 
always  be  viewed  with  suspicion  in  this  class  of 
piBDt.  It  is  obvious  that  the  ordinary  safe 
working  stresses  adopted  by  mechanical  engineers 
are  not  suitable  for  designing  autoclaves. 

Considerations  relating  to  the  eSect  ol 
temperature  and  chemical  action  may  arise- 
In  the  case  of  CAst  metal  auto('lav.n8  the  grettest 
care  in  design,  in  selecting  the  material,  and  in 
casting  to  minimise  internal  stresses  must  be 
taken.  When  treating  liquids,  suitable  pipes 
for  odmission  and  (fischarge  may  make  it 
unnecessary  to  remove  the  cover  under  ordmary 
circumstances,  but  when  solid  substances  are 
charged,  the  mechanical  problem  of  repeatedly 
making  a  tight  Joint  prewnts  itself.  £atension 
of  the  cover  bolts  under  steess  and  heat  most  be 
considered  to  avoid  leakage  under  the  worst 
working  conditions. 

The  joint  is  usually  made  by 
tongue  in  the  cover  pressing  ou  a  soft  metal 
ring  in  a  groove  made  in  the  llange  of  the  body. 
A  broad  suriaoe  is  unsuitable  and  in  the  case  ol 
»  eo^per  ting,  a  beating  area  not  more  than 
one-eighth  inch  wide  is  usually  satisfactory  at  all 
prcsBures.  Such  a  joint  may  be  remade 
hundreds  of  times  without  failure.  On  aooonnt 
of  ita  high  elastic  limit,  nickel  steel  is  the  most 
suitt^le  material  for  both  bodies  and  bolts  of 
high-pressore  autoclavea,  and    by  the 


high-pm 
■ditoble 


When  a  kMise  container,  aa  shown  in  Fig.  2, 
Is  employed,  the  spaoa  between  the  body  and 

the  oontainer  should  be  Slled  with  a  liquid 
(paraffin  wax  is  genendly  most  suitable)  to 
improve  the  rate  of  heat  tranaference. 

J.  W.  H. 
ADTOLniS,    A  physiological  term  ngni- 

5 ling  seU-deatmotion,  and  used  to  indicate  the 
estruetiTe  changes  (apart  from  putrefaction  due 
to  micro-oiganisms)  which  occur  in  ceils  after 
death  or  removal  from  the  living  body.  These 
hanges  are  due  to  the  action  ot  In tia- cellular 


identical  with  those 
which   occur  during   life 

the  forma-  „ 
tion  ol  waste  substances,  t 
the  products  of  vital 
activity.  During  life, 
however,  the  destructive 
changea  are  counter- 
balaneed  by  changes  in 
the  opposite  direction  by 
which  the  cells  build 
themselves  up  from  food 
materials  to  repair  their 
wear  and  tear.  Assimi- 
lation of  this  kind  is 
■  ivioosly  impossible  after 

AUTDHITE  or   CAL- 
-    CRANITE.  A 

mineral  consisting  of 
hydrated  phosphate  of 
uranium  and  calcium 
Ca(U0,l,P,0,-8H,0, 
which  within  recent  years 
hag  been  somewhat  ex- 
tensively mined  ns  an  ore 
of  uranium  and  radium. 
It  is  a  member  of  the 
isomorphous  group  of 
mineials  known  as  the 
'  uranium  micas,'  which 
crystallise  in  square, 
tetragonal  (or  very  nearly 
square,  '  orthorhombic) 
plates  with  a  perfect 
mioacoous  and  pearly 
cleavage  parallel  to  their 
surface.  In  the  ortho- 
rhombic  autunite  the 
colour  is  characteristically 
sulphur.yellow,  or  some- 
times with  a  greenish 
tinge,  so  that  this  mineral 
is  readily  distinguished 
from  the  emerald-green 
torbemite  or  cupro-uia- 
nite.  Sp.gr-  3-1 ;  H-  2-2^. 
It  occurs  as  an  altera. 
tion  product  of  pitch- 
blende, and  is  often  fonnd 
as  a  Bcal^  enomslation 
on  the  ]oint-planea  of 
weathered  granite  < 
portant  localities  a 
Antun  in  France  (hence  t 
St.  Just,  Redruth,  and  Grampound  Road  in 
Cornwall ;  Johanng^rgMutadt  and  Falken- 
stein  in  Saxony  ;  Black  Hills  in  Bouth  Dakota ; 
Olary  and  Mount  Painter  in  South  Anstnlia; 
and  Sabugal,  near  Qnarda  in  PortogaL  At 
the  last-named  locality  teveral  mines  have 
recently  been  opened  up ;  the  crude  ore  is  here 
leached  with  sulphuric  acid,  and  the  eitncts 
sent  to  li'aris  for  further  treatment.      la  J.  8> 


Fio.  4, 
gneiss.    The   mo[«  im- 
St.    Symphorien,    near 
autunita) ; 


AZAFRAN. 


435 


AUXOCHROME  v.  Coloub  and  Ghbmical 
CoirsTiTnnov. 

AVA  or  Kava-katfa.  The  root  of  Piper 
meUiyslicum  (Font,  f.),  growing  in  the  lolaDds 
of  the  Pacific.  It  is  taken  aa  an  intoxicant  by 
the  natives,  and  ia  used  as  a  drug  on  the  Con- 
tinent. It  is  often  adulterated  with  matico 
and  annatto  (Phann.  J.  [3]  7, 140). 

AVBNTURINE  or  AVANTURINE.  A  variety 
of  quartz  found  at  Capa  de  Gata,  Spain,  spangled 
throughout  with  minute  yellow  scales  of  mica, 
ia  known  as  aventurine  quartz.  An  aventurine 
felspar  or  sunstone  is  found  at  Tvedestrand, 
Norway.    It  is  used  for  ornaments. 

Artificial  avenltrtne,  or  glaaSf  or  goid  fittx, 
was  manufactured  for  a  long  period  at  the  glass- 
works of  Murano,  near  Venice.  It  may  be  pre- 
pared by  adding  to  100  parts  of  a  not  too  re- 
fractory glass,  8  to  10  parte  of  a  mixture  of  equal 
parte  of  terrous  and  cuprous  oxides,  and  allowing 
the  mixture  to  cool  very  slowly  so  as  to  facilitote 
the  formation  of  crystals. 

AtfeiUurine  glaze  for  porcelain,  invented  by 
Wohler  (Annalen,  70,  57),  is  prepared  by  finelv 
grinding  31  parte  Halle  kaolin,  43  quartz  sand, 
14  gypsum,  and  12  porcelain  fragmente ;  making 
the  wnole  into  a  paste  with  300  parte  water,  and 
adding  successively  19  parte  potassium  dichro- 
mate,  47  lead  acetate,  100  ferrous  sulphate,  and 
sufficient  ammonia  to  preoipiteto  the  whole  of 
the  iron.  After  the  soluble  potash  and  am- 
monium salte  have  been  washed  out,  the  glazing 
ia  ready  for  use. 

AVIGNON  GRAINS.  The  seeds  of  i2AamniM 
infectoriuSf  employed  in  dyeing  for  the  produc- 
tion of  ydlow  coloon  (v.  Bhamnin^  art  Xan- 

THOBHi^anH). 

AVOCADO  PEAR  or  ALUGATOR  PEAR. 

The  fruit  of  Persea  graiisMtnat  a  tropical  product. 
The  fruit,  which  usually  weighs  from  4  to  6 
oz.,  oonsiste  of  rind  (about  8  p.c.),  flesh  (67  pc), 
and  a  large  'stone*  or  *pit*  (about  25  p.c.). 
According  to  Prinaen-Qeerlings  (Chem.  Zeit. 
1897,  21,  716),  the  flesh  conteins  : 

Glucose     Fraotoss     Saecfaaioie     Total  logat 
0-40        0-46  0-86  1*72 

The  flesh,  which  has  a  nut-like  flavour,  is 
ttsuaUy  eaten  with  pepper  and  salt.  An  analysis, 
made  Dy  Janueson  ((Jhem.  News,  1910, 102,  61), 
gave: 

Water    Ether  eztnMA  Protein    Sugar     Fibre     Ash 
ftfl-9  10-6  5-7         11        4-0       20 

The  ether  extract  was  green,  and  contained 
about  4  p.e.  of  resins.  After  their  removal,  an 
oil,  res^nrbling  that  of  bergamot,  was  obtained, 
which  had  an  iodine  value  of  29-9,  and  saponi- 
fication value  of  207.  La  Forge  (J.  Biol.  Cnem. 
1916,  24)  found  that  the  sugar  present  in  tiie 
pulp  of  the  ripe  fruit  could  be  extracted  with 
water  and  cryeteUises  from  dilute  alcohol  in 
hexagonal  prisms,  m.p.  152^.  It  is  non- ferment- 
able and  not  oxidised  by  bromine,  and  is  probably 
mannoketoheptoae.  H.  I. 

AVOCADO  PEAR,  OIL  OF.  An  ofl  obtained 
from  the  oleaginous  fruit  of  the  Perua  gratisnma, 
Uofmann  stated  that  for  the  purposes  of  the 
soapmaker  this  oil  would  be  aa  valuable  as 
palm  oil. 

AWAL  or  Tarwar,  An  Indian  drug,  the 
bark  of  Cassia  anricvUUa  (Limu)  (Dymock, 
Pharm.  J.  [2]  7.  977). 


AWLA  V.  AifLA.si. 

AXIN.  A  waxy  secretion  of  a  Mexican 
rhynchotrous  insect  Liaveia  axinus  which  feeds 
on  Spondias  luita^  XatUhozylufn  Clata-f^erculis, 
and  A.  pentanome :  has  the  consistence  of  butter, 
the  smell  of  rancid  fat,  and  a  yellow  colour. 
Melto  at  3S^  and  ia  soluble  in  hot  alcohol  and 
ether.  ^  Rapidly  absorbs  oxygen  from  the  air, 
becoming  brown,  hard  and  insoluble  in 
alcohol  and  ether.  Is  readily  saponified,  yield- 
ing axinic  acid  and  glycerol.  It  rcsemLles 
Japan  lao  and  forms  an  excellent  lacquer  for 
wood,  metels,  and  pottery  (Bocquillon,  J.  Phirm. 
Chim.  1910,  2,  406;  J.  Soc  Chem.   Ind.  29, 

AXINITE,  A  complex  borosilicate  of  alu- 
minium, calcium,  iron  and  manganese.  Various 
formula  have  been  proposed:  W.  E.  Ford 
(1903)  gives  R'%R'"4BJSiO-)„  where  R"=Ca, 
Fe,  Mn,  Mg,  H,,  and  R^"==A1,  Fe.  According  to 
W.  T.  Schaller  (1909)  the  composition  is  ex- 
pressed as  isomorphous  mixtures  of  *  ferro- 
axinite '  4CaO'2FeO-2Al,0,B,0,-8SiO,H,0, 
and  *  manganaxinite  '  4CaO-2MnO-2Al,0,-B,Oa. 
8SiO,*H|0.  The  mineral  conteins  5-6  p.c. 
B|0,.  Crystals  are  triclinic  with  a  T^haracter- 
istic  axe-shaped  habit,  hence  the  name.  The 
colour  is  usually  dove-brown,  but  may  he 
yellowish  or  greenish.  D3  03-3 -36,1101 -7. 
Axinite  occurs  in  ciystelline  schiste  and  mcte- 
morphic  rocks  at  many  localities.  Fine  crystals, 
suitable  for  cutting  as  gem-stones,  are  not  un- 
common from  Bourg  d'Oiaans,  Is^re,  France, 
and  large  groups  of  crystals  come  from  Japan. 
In  the  metamorphic  rocks  surrounding  the 
granite  mass  of  Bodmin,  in  Cornwall,  massive 
axinite  and  axinite-rock  are  of  abundant 
occurrence  (G.  Barrow,  Mineralog.  ^lag.  1908, 
XV.  113 ;  Geology  of  Bbdmin  and  St.  Austell, 
Mem.  Geol.  Survey,  1909). 

Tourmaline  {q.v.)^  another  complex  boro- 
siUcate  containing  rather  more  boron  (B|0,  9-11 
p.c),  is  also  of  common  occurrence  under  the 
same  conditions  in  Cornwall  It  is  possible  that 
these  occurrences  may  be  of  use  as  a  source  of 
boron.  L.  J.  S. 

AZADIRACHTA,  Margosa,  or  Nim,  The 
bark  of  the  nlm  tree,  Mdia  indica  (Brandis) 
[M.  Azadiraehid],  is  commonly  used  in  India  as 
a  touic  and  febrifuge.  It  contains  a  bitter  resin. 
An  oil,  used  in  medicine  and  for  buminff  ia 
expressed  from  the  seeds,  which  on  saponifica- 
tion yielded  35  p.c.  of  fatty  acid  molting  at  30^, 
and  65  p.c.  melting  at  44^. 

AZAFRAN  or  AZAFRANILLO.  The  root  of  a 
plant  obtained  from  Paraguay,  belonging  to  the 
family  of  the  ScrophulafiaceaSf  used  to  colour 
fate.  Contains  about  1  p.c.  of  a  dye  (azafrin) 
easily  extracted  by  boiling  benzene.  Forms 
orange-red  cruste  of  microscopic  needles, 
m.p.  214*.  Does  not  contain  nitrogen  or 
methoxy-  or  ethoxy-  groups;  one  hydroxyl 
group  is  shown  bv  Zerewitinoff*s  method.  Uvea 
wool  yellow,  and  forms  yellow  to  orange  lakes 
with  Scheurer's  mordants ;  wool  extracte  the 
whole  of  the  dye  from  a  hyposulphite  vat. 
Gives  a  fine  blue  solution  in  concentrated  sul- 
phuric acid,  which  becomes  violet  on  adding 
alcohol  (Liebermann,  Ber.  1911,  44,  850).  It  is 
not  identical  with  blxin,  as  conjectured  by  van 
Hasselt,  in  spite  of  the  similarity  in  their  re- 
actions.   The  acid  reactions  of  azafrin  afford  a 


436 


AZAPRAN. 


good  example  of  haloohromiBm.  Methyl-azafrin, 
obtained  by  the  action  of  dimethyl-sulphate, 
gives  a  series  of  salts  parallel  vnth  those  of  the 
parent  substance  (Liebermann  and  Sohiller, 
Ber.  1913»  46,  1973). 

AZ£LAIC  ACID.  Lepargylie  add.  GO,H* 
(CH,),-COtH.  It  is  obtained  by  oxidising 
Chinese  wax  (Buckton*  J.  I857»  803),  cocoanut 
oil  (Wine,  Annalcn,  104,  261),  or  castor  oil  (Arppe, 
Annalen,  124,  86)  ^th  nitric  acid;  by  tne 
oxidation  of  oleic  acid  with  potassium  perman- 
ganate and  caustic  potash  (Ehmed,  Chem.  Soc. 
Traoa.  1 898, 627),  and  by  the  oxidation  of  keratin 
(horn  shavinfis)  with  permanganate  (Lissizin, 
Zeitach.  ph^sioL  Chenu  1009,  226).  It  is  formed 
toother  with  other  products  when  fats  or  oleic 
acid  become  rancid  (Soala,  Chem.  Zentr.  1898, 
i.  439).  It  has  been  synthesised  from  penta- 
methylene  bromide  and  sodium  acetoacetate 
(Ha worth  and  Perkin,  Chem.  Soc.  Ttana.  1894, 
86),  and  has  been  obtained  by  decomposing  the 
ozonide  of  oleic  acid  (Molinari  ana  Soncini, 
Ber.  1906,  2736;  Harries  and  Thiome,  ibid. 
1906.  2844;  Molinari  and  Fenaroli,  ibid.  1908, 
2789).  It.  is  best  prepared  by  oxidising  with 
potassium  permancanato  an  alkaline  solution 
of  riotnoleic  acid  Ootained  by  the  hydrolysis  of 
castor  oil  (Maouenne,  BulL  Soa  chim.  1899, 

iiLj  21»  106;   Uasura  and  GrQssner,  Monatsh. 

V  476).  Azdaio  acid  crystallises  in  colourless 
plates,  m.n.  106*2*  (Massol,  BulL    Soc   chim. 

3]  19,  301),  and  is  readily  soluble  in  alcohol, 

ess  soluble  in  water  or  ether.  By  heating 
acelaic  acid  with  soda  lime,  azelaone  (cyclo- 
nonanone) C.H.JO,  b.p.  205* (circa),  is  obtained 
(Miller  and  fbchitBchkin,  Chem.  Zentr.  1899, 
ii.  181);  Harris  and  Tank  (Ber.  1907,  4556) 
have  shown  that  a  complex  mixture  of  oydo- 
ketones  is  obtained  by  distilling  the  calcium 
salt  of  azelaic  add.  Azelaic  anhydride  is 
obtained  by  heating  aselaic  acid  with  7-8  pts. 

of  acetyl  chloride.  It  melts  at  56*-57*  (£taiz, 
Ann.  dhim.  Phrs.  [7]  9,  399). 

AZELAONB  «.  aimlaio  acid. 

AZmiHB  BLACK,  -BLUE,  -BORDEAUX. 
-BROWN,  -FAST  RED,  -FAST  SCARLET, 
-GREEN,  -ORANOE,  -PURPURINE,  -YELLOW, 
-VIOLET,  -WOOL  BLUE  v.  Azo-   oouovbssq 

MATTSBS.  

AZimNOBENZENE  v.  Diazo  ooMFOuin>a 
AZIHINONAPHTHALENES  v.  Diazo  com- 

POUITDS. 

AZINES  (QnlnozaUnes).  Aionlnm  bases, 
and  eoloiiring  matters  derived  from  them. 

Definition. — ^The  term  'azines'  has  been 
^iven  to  a  group  of  organic  bases,  which  contain 
in  their  molecule  as  an  intrinsic  part  of  their 
constitution  a  heterocyclic  hexagonal  ring,  built 
up  of  four  carbon  and  two  nitrogen  atoms, 
arranged  in  such  a  manner  that  the  nitrogen 
atoms  stand  in  para-position  to  each  other, 
whilst  the  four  carbon  atoms  are  disposed  in 
two  pairs  between  them,  thus : 


i 


1 


The  term  *  azine,*  first  proposed  by  Merz,  is 
not  happily  chosen,  and  is  even  misleading,  as 
it  enters    into  the   nanies   of    other  nitrogen 


compounds  of  a  different  constitution,  such  as 
thehydrazineB. 

The  name  '  quinoxaline '  was  given  by 
Hinsbeig  to  compounds  which  idso  correspond 
with  the  above  definition.  It  was,  therefore,  con- 
sidered for  some  time  as  synonymous  with  the 
word  *  azine,*  which  latter  was,  however,  more 
frequently  used.  In  later  years  it  has  become 
customary  to  distinguish  between  the  two  terms, 
and  to  use  them  for  the  two  tautomerio  forms 
in  which  these  bases  occur  (see  Theory). 

The  name  '  azonium  bases  *  has  been  given 
by  Witt  to  a  class  of  organic  bases,  derived  from 
the  azines  by  the  linking  of  a^  organic  radicle  to 
one  of  the  nitrogen  atoms,  whereby  this  atom 
passes  from  the  trivalent  into  the  pentavalent 
state,  a  process  which  results  in  a  very  marked 
change  of  the  properties  of  the  substance. 

Both  the  azines  and  azonium  bases  possess 
the  nature  of  powerful  chromogens,  the  netero- 
oydic  ring  above  mentioned  being  endowed  with 
strong  ohromophorio  properties.  Behig  highly 
basic  and  capable  of  assuming  a  quinonoid  stmo* 
ture  [see  Theory),  they,  and  especially  the 
azonium  bases,  possess  to  some  extent  the 
nature  of  dyestufb,  which  is,  however,  much 
more  strongly  developed  by  the  introduction  of 
separate  auxochromio  groups.  A  very  large 
number  of  powerful  colouring  matters  of  great 
intensity,  variation,  and  punty  of  shade  may 
thus  be  obtained,  some  of  which  have  acquired 
considerable  practical  importance.  According 
to  their  constitution,  which  is  in  almoet  all  cases 
completely  cleared  up,  thoy  have  been  classified 
into  groups,  which  have  received  the  names 
eurhodines,  eurhodois,  safranines,  sa- 
franols,  aposafranines,  indulines,  and 
fluorindines. 

The  inveBti|^ation  of  the  azines  and  their 
derivatives,  which  was  accomplished  by  a  num- 
ber of  ohenuats  during  the  last  20  yean  of 
the  nineteenth  century,  nas  been  of  considerable 
importance  in  the  development  of  our  present 
views  on  the  constitution  of  colouring  matters, 
and  especially  in  the  adoption  of  the  modem 
quinonoid  stmotural  formula  for  the  great 
majority  of  them. 

History. — ^The  two  simplest  and  most 
typical  members  of  the  azine  group,  diphenazine 
and  dinaphtazine,  have  been  known  lor  many 

(ears  as  ^  azophenylene '  (dans  and  Rasenaok, 
873;  Annalen,  168,  1)  and  'naphtase' 
(Laurent,  1835;  Ann.  Chim.  Phys.  69,  384), 
but  their  constitution  was  not  properly  under- 
stood and  their  importance  not  recognised. 
Merz  (1886,  Ber.  19,  725)  finally  proved  the 
constitution  of  the  former,  which  had  been  in- 
sufficiently substantiated  by  CSIaus,  and  pro- 
posed for  it  the  name  diphenazine ;  Witt  (1886, 
Ber.  19,  2791)  determined  the  true  nature  of 
*naphtAse.'  In  1884  Hinsberg  (Ber.  17,  319) 
described  a  general  method  for  preparing  his 
quinoxalines,  which  proved  most  rruitful  in  the 
further    development   of    the    subject.    Other 

faneral  methods  were  discovered  by  Witt,  Mers, 
app,  Ullmann,  and  others. 
The  first  eurhodines  were  prepared  hj  Witt 
in  1879  and  1885.  He  recognised  that  they 
formed  a  new  class  <^  dyestnflEs,  and  also 
that  they  were  related  to  the  safranines.  He 
determined  their  constitution  in  1886  (Ber.  19, 
441)  b^  showing  that  the^  are  the  amino-  denva* 


AZtKSS. 


4S7 


tives  of  the  azines  ot  quinozalinos.  At  the 
game  time  he  dinovered  the  first  eurhodol.  The 
nataral  ooDseqaeiiioe  of  thw  diaooyery  was  the 
clearing  up  of  the  nature  of  the  flafranines, 
which  were  recognised  in  the  same  year  simol- 
taneously  and  independently  b^  Witt»  Nietaki, 
and  Bemthsen  as  diamino-  derivatives  of  the 
(then  hypothetical)  asoninm  bases.  The  first 
representative  of  this  new  class  of  bases  was 
prepared  in  1887  by  Witt  (Ber.  20, 1183). 

The  subject  was  now  taken  up  and  rapidly 
advanced  by  many  chemists,  amonsst  whom 
Nietski  and  his  collaborators,  fehrmann, 
Ullmann,  and  their  collaborators,  may  Jbe  cited. 
Otto  FuMher  and  Hepp  also  did  a  considerable 
amount  of  work  in  this  domain,  and  especially 
in  the  investigatioii  of  the  indulines  and  apo- 
lafranines. 

The  typical  indulines  and  safraninea  have 
been  discovered  by  purely  empirical  methods 
in  the  early  days  of  the  colour  industry.  The 
simplest  representative  of  the  group,  phenO' 
safranine^  was  prepared  by  Witt  in  1877.  Its 
phenyUted  derivative  is  mauv^ne,  the  first  arti- 
ficial dyestuli  prepared  by  W.  H.  PerJdn  in  1866. 

Theory. — It  has  been  already  stated  that 
the  essential  part  of  the  molecule  of  an  azine  is 
the  heterocyclic  ring  consistiiig  of  two  atoms 
of  nitrogen  and  four  of  carbon.  Each  of  these 
six  atoms  has  three  valencies  engaged  in  the 
fonnation  of  the  ring ;  the  nitrogen  atoms  have, 
therefore,  no  free  valencies  left  (so  long  as  thev 
remain  in  the  trivalent  condition),  whilst  each 
of  the  carbon  atoms  has  one  valency  free  to  be 
saturated  by  hydrc^Ken  or  another  monovalent 
element  or  radicle.  The  simplest  possible  com- 
pound  ol  the  kind  would  thus  have  the  formula 
C4N,H4.  It  seems  natural  to  suppose  that  it 
would  be  the  prototy^  of  all  the  aunes. 

Such  a  cpmpouna  exists  and  is  well  known. 
It  has  received  the  name  pyrazine.  Many 
derivatives  of  it,  formed  by  the  substitution  of  its 
hydrogen  atoms  by  monovalent  organic  radicles 
are  also  known ;  they  form  the  large  and  well- 
investigated  class  of  the  ketine  or  aldine  bases. 
But  neither  pyrazina  itself  (which  in  its  properties 
resembles  pyridine,  to  which  it  stands  m  the 
same  relation  as  pyridine  stands  to  benzene)  nor 
the  ketines  show  any  resemblance  to  the  typical 
azines.  They  exhibit  no  colourations,  nor  do 
they  form  any  derivatives  which  have  the  nature 
of  ayestu&.  For  this  reason  pyrazine  and  the 
ketines  are  no  longer  considered  as  belonging  to 
the  azine  group. 

The  characteristic  properties  of  the  azines 
only  appear  in  compounds  in  which  at  least 
one  other  ring  system  is  linked  to  the  pyrazine 
ring,  in  such  manner  that  one  of  the  Oa-gi^ups 
of  the  latter  becomes  part  of  an  aromatic 
radide.  The  process  may  be  repeated.  Thus 
the  simplest  representatives  of  the  azine  group 
would  be  compounds  of  the  following  type : — 

Fheoadne.  Dlphenasins. 

The  nomenclature  of  the  true  azines  has  been 
chosen  accordingly.  The  aromatic  radicle  or 
radicles  linked  to  the  central  (or  '  meso  •')  ring 
are  j^refixed  to  the  syllables  •azine. 


The  arine^  are  members  of  the  aromatic 
If  we  consider  them  as  such,  we  rocognise 
at  once  a  strons  analogy  to  other  substances 
which  contain  neterocydio  ringp  linked  to 
aiomatio  radicles,  sooh  as : 

0 


apo 


A 


AnthraqulnoiM. 

k 

Ozaxins. 


Aflridins. 
6 


(XX) 


Thiaiine. 


all  of  which  are  chromogens,  like  the  asioes. 

If  we  consider  the  manner  in  which  the  six 
atomicities  of  the  two  nitrogen  atoms  contained 
in  the  meso-  ring  of  an  azine  may  be  disposed,  we 
recognise  two  possibilities  which  are  repre- 
sented in  the  following  structural  formula  of 
diphenazine : — 


/i\/' 


n. 

Formula  I.  is  the  one  first  proposed  by  CSaiis 
for  his  *  azophenylene,'  and  by  Merz  for  his 
azines ;  II.,  the  one  sugsested  by  Hinsbeigf or  his 
quinoxi^es.  Practiudly,  there  is  no  difference 
between  azines  and  quinoxalines ;  they  form 
one  group;  but  it  has  been  for  a  long  time 
a  matter  of  opinion  which  of  the  above 
f ormulflB  was  more  adapted  to  the  properties  of 
these  substances.  Formula  L  explains  bv  its 
perfect  symmetry  the  extreme  stability  of  the 
azines,  the  fact  that  they  may  all  be  distilled 
without  the  slightest  decomposition  at  extremely 
high  temperatures.  Formula  IL,  on  the  other 
hand,  is  oistinctly  (ortho-)  quinonoid,  and  con- 
sequenUy  suggestive  of  chromogenio  proper- 
ties. 

The  existing  difference  of  opinion  as  to  the 
constitution  of  the  azines  has  been  finally  dis- 
posed of  by  the  admission  that  the  azines  are 
undoubtedly  tautomeric,  capable  of  assuming 
either  of  the  constitutions  L  and  II.,  accord- 
ing to  circumstances.  In  their  free  state,  in 
which  they  are  volatile  and  almost  colourless, 
they  possess  the  symmetrical  (azine-)  constitu- 
tion I.,  whereas  in  their  intensely  coloured  salts 
they  have  more  probably  the  asymmetrical, 
quinonoid  (quinoxaline-)  constitution  IL  In  the 
oolouriiu;  matters  derived  from  the  azines,  the 
case  is  nequently  complicated  by  the  fact  that 
the    auxo(Miromio    groups   participate    in    the 


438 


AZINES. 


formation  of  the  quinonoid  constitution,  which, 
by  that  means,  may  become  parat-  as  well  as 
orfAo-quinoid.  Sometimes  it  is  difficult  to 
decide  between  the  existing  possibilities. 

Syniheiical  methods  for  the  production  of 
azines,  and  their  derivattves  and  description  of 
some  typical  representatives  of  the  group. 

1.  Azines.  (a)  Sffrdhetical  methods.  (These 
will  be  referred  to  in  the  description  of  typical 
representatives  by  their  number.) 

1.  By  heating  a-nitronaphthalene  with 
powdered  quicklime,  Laurent  (Ann.  Chim.  Phys. 
69,  384)  obtained  dxnaphthazine,  which  he 
called  naphthase.  Doer  (Ber.  3,  291)  and 
Klobukowski  (Ber.  10,  573)  modified  the  method 
by  replactns  the  quicklime  by  zinc-dust^  Schi- 
chuzky  (J.  K.  6,  2404)  used  lead  oxide. 

Wohl  and  Aue  (Ber.  34.  2443)  observed  (1901) 
that  nitrobenzene  gives  considerable  quantities 
of  diphenazine  on  being  heated  with  strong 
caustic  soda,  a  reaction  which  is  practically 
identical  with  the  one  discovered  by  Laurent. 

2.  daus  and  Rasenaek  (Annalen,  168,  1) 
obtained  *  azophenylene '  (diphenazine)  by  the 
dry  distillation  of  orthoazobenzoio  acid  in  the 
shape  of  its  calcium  or  potassium  salt.  Glaus 
proposed  the  azine  formula  for  his  product,  but 
failed  to  afford  convincing  proofs  for  it. 

3.  A  general  method  of  great  applicability 
was  mdicated  by  HinsberB  (Ber.  17,  319 ;  18, 
1228),  who  showed  that  whenever  an  alpha-  or 
oriAo-diketone  reacts  on  an  aromatic  ortho- 
diamine,  two  molecules  of  water  are  given  off  j 
tnd  an  azine  is  formed.  The  method  was  first 
applied  to  the  production  of  phenazine : 


/- 


0     H,N— /\ 

I        + 
C-0     H,N— 

\ 


V 


GlyozaU       o-Phcnylenediamlne.  Phenazine 

(quinozaiine). 

It  works  in  most  cases  so  well,  that  it  has  been 
recommended  by  its  author  (Annalen,  273,  343, 
371)  as  the  beet  method  of  identifying  either  an 
orthodiamino  or  an  orthodiketone.  Very  small 
ouantitiee  of  the  ingredients  are  necessary,  and 
tne  azine  formed  is  easily  recognised  by  its 
melting-point  and  sulphuric  acid  reaction. 

Hinsoerg's  reaction  nia^  be  extended  to 
nitroso-iB-naphtbol,  which  is  in  reality  the 
oxime  of  ortho-naphthaquinone.  Ulimann  and 
Heisler  obtained  (Ber.  42,  4263)  naphthaphen- 
azine  by  heating  ortho-phenylenediamine  hydro- 
chloride with  nltro80-/3-naphthol : 


les4  general  application.  It  consists  in  the 
action  of  orthodihydroxyl-  derivatives  upon 
orthodiamines :  the  hydro-  derivatives  of  the 
azines  are  formed,  and  these  are  oxklised  by 
the  oxygen  of  the  air  into  the  azicos : 

v/— OH  ^  H,N— v^y'  ^ 
PyrocatechoL    Orthophenylene  diamine. 

Dtphcnaiine. 

6.  Early  investigators  had  studied  the  re- 
action of  ammonia  under  pressure  upon  benzoin 
(Erdmann,  Annalen,  135,  181)  and  phenanthra- 
qninone  (Sommaruga,  Monatsh.  1,  146).  Japp 
and  Burton  shownl  that  the  free  ammonia 
may  be  advantageously  replaoed  by  ammonium 
acetate,  and  proved  that  the  *  ditolane  aiotide ' 
and  *  phenanthrene  azotide  *  obtained  were 
tetraphenyiketine  and  di)>henanthrazine.  They 
generalised  the  method  and  applied  it  to  fi- 
naphthaquinone,  from  which  they  obtained 
dinaphthazine  (Chem.  Soc  Trans.  1887,  98). 

6.  Another  mode  of  formation  of  the  azines 
consists  in  the  joint  oxidation  of  a  phenol,  in 
which  the  para-  position  is  no  longer  open  to 
substitution,  and  aromatic  orthodiamines.  This 
method  was  discovered  by  Witt  (Ber.  19,  917), 
who  used  it  for  the  production  of  a  new  isomende 
of  tolunaphthazine  by  oxidising  a  mixture  of 
fi-naphthol  and  orthotolylene  diamine : 


NH. 


-OH  +  n,N- 


I 


cn. 


-f20 


^NaphthoL 


Orthotolylfoie  diamine 


A^ 


9r' 


H,N 


H,N 


+    Ha 


-  k/  I       -f  3H,0. 

I^/LCH. 

To|anaphthaxtno. 

7.  An  elceant  modification  of  the  above 
method  was  devised  in  1905  by  Ullroann  and 
Ankersmit  (Ber.  38,  1811),  who  heated  $• 
naphthol  with  orthoaminoazotoluene.  The 
latter  takes  up  the  hydrogen  liberated  in  the 
reaction,  yieldmg  at  the  same  time  the  neoeswry 
orthodiamino. 


Nitfoso-/i-naphtlioL  Orthophenylene  diamine. 


-fH,0  +  NH,OHHCL 

Hydroxylamlne 
hydroohioride. 

Naphthapheoaxine. 
4.  The  method  of  Mors  (Ber.  19,  725)  is  U 


00-0= 


C,H, 

I 
N 

I 


^-NaphthoL 


OrthoaminosiotttlttBQSb 


AZINES. 


439 


n/  I       +  H,0. 
Tolunaphthaiiiie. 


8.  A  verj  peculiar  mode  of  formation  of 
these  substances  was  discovered  by  Witt  (Ber. 
20,  671),  who  showed  that  the  orthoazo-  deriva- 
tives of  secondary  amines,  and  more  especially 
of  such  amines  containing  the  /3-naphthyl-  group, 
are  decomposed  by  being  heated  with  aoicb  into 
the  corresponding  azine  and  »mino-  compound, 
ihusx 


O.H. 


C.Ht 
AnUlne. 


Benssne-aio-phenyl- 
^nsjihtliylamine. 


NaphtbaphenazlM. 


reactions  are  hishly  characteristic,  and  form  the 
best  means  of  identifying  the  azines. 

Notwithstanding  these  intense  colourations* 
the  azines  are  not  applicable  as  dvestufiEs.  lliey 
are  only  to  be  considered  as  onromogens  and 
suitable  to  produce  colouring  matters  by  the 
introduction  of  auxochromio  groups  into  their 
molecules.  They  are  thus  strictly  analosous 
to  the  other  heterocyclic  ohromogens  such  as 
anthraquinone,  acridine,  ozazine,  and  thiazine. 

There  is,  however,  one  group  of  aiines  to 
which  all  the  rules  and  general  characteristics 
given  above  cannot  very  well  be  applied.  These 
are  the  *  Indanthrenes,*  certain  azines  of  the 
anthracene  group,  which,  owing  to  their  large 
molecule  and  very  complioatM  constitution, 
possess  properties  quite  different  from  all  the 
other  azmes.  They  are  intenselv  coloured  and 
extremely  valuable  as  dyestuffs  if  applied  to  the 
textile  fibre  by  the  *  vat  nrocess  ^  like  indiga 
This  peculiar  mode  of  application  brinn  them 
into  dose  relationship  with  indigo,  and  they  will 
therefore  be  treated  m  this  work  under  IiCDiao 

▲KD  DTDIQOID  DTISTUtfS  (g.V.)* 

(c)  Desaiplion  oj  some  typical  represintaiivti 
ofVu 


The  reaction  !s  simple  and  easy,  and  gives, 
as  a  rule,  excellent  yields.  It  is  in  reanty  a 
oondensation  of  the  secondary  amine  into  the 
corresponding  azine  by  the  dehydrosenating 
influence  of  the  azo-  group  temporarily  intro- 
duced for  the  purpose. 

(b)  (Tenerte  characUrB  of  the  azine  group.  All 
azioM  have  certain  peculiar  properties  in  com- 
mon. As  a  rule,  they  are  solid,  well-crystallised 
compounds  of  white,  pale  vellow,  or  even  orange 
colour,  possessing  a  high  melting-point,  and 
boiling  under  atmospheric  pressure  at  very  high 
temperatures  (in  some  cases  approaching  rod 
heat)  practically  without  decomposition,  xhey 
sublime  at  temperatures  below  their  boiling- 
point,  and  their  vapours  condense  into  volu- 
minous aggregates  of  crystals. 

All  the  azines  are  bases  which  form  salts 
with  acids.  The  mono-acid  salts,  with  the 
stronger  mineral  adds^may  generally  be  obtained 
in  a  crystallised  condition ;  but  they  aro  stable 
only  in  the  presence  of  an  excess  of  acid  or  in 
the  absenoe  of  water,  which  easily  decomposes 
them  into  their  constituents.  These  salts  are 
intensely  coloured,  a  fact  which  iustlBes  the 
inference  that  thev  contain  the  base  in  the 
quinonoid  (quinoxsline)  form.  The  hydrolytic 
action  of  the  water  is  therefore  accompanied  by 
the  tautomeric  change  into  the  symmetrical 
(azine)  form.  These  salts,  some  of  which  have 
been  analysed,  invariably  contain  one  equivalent 
of  acid  for  one  molecule  of  the  base.  The  di-acid 
salts  cannot  be  isolated,  but  evidence  of  their 
existence  is  given  by  the  intense  red,  violet,  or 
blue  colourations  euiibited  by  the  solutions  of 
azines  in  a  great  excess  of  strong  acid,  preferably 
sulphuric  acid.  If  water  be  added  to  these 
idhitionsr  a  ohanffc  takes  place;  the  di-acid 
salt  is  deoomposec^  the  yellow  or  orange  mono- 
acid  salt  is  formed,  and,  on  further  a<Mition  of 
a  large  excess  of  water,  the  free  azine  itself 
separates  oat  in  flakes.    These  striking  colour 


anne  group» 

Dlphenailnt 


C„H^, 


aix) 


(Glaus,  Annalen,  168,  1 ;  Bemthsen,  Ber.  10, 
3250 ;  Ris,  Ber.  19,  2200 ;  Wohl,  Ber.  34,  2443) 
has  been  obtained  by  the  methods  1,  2,  and  4^ 
It  forms  pale-yellow  needles,  of  the  m.p.  170*- 
171*,  soluble  in  alcohol  and  most  other  solvents. 
It  distils  without  decomposition.  It  dissolves 
in  strong  acids,  forming  unstable  salts  of  yellow 
and  red  colour. 
Tolaphenazine 


-ax> 


N' 

has  been  prepared  by  Merz  (Ber.  19,  725)  by  the 
action  of  pyrocatechol  on  orthotolylenediamine 
(method  4).    It  is  very  similar  to  diphenazine. 
Its  m.p.  is  117*,  its  Kp.  350*. 
Maphthaphenaiin* 


CuHj^g » 


has  been  prepared  hj  Witt  (Ber.  20,  571).  The 
best  mode  of  obtainmg  it  is  by  the  decomposi- 
tion, by  acid,  of  the  azo-  compounds  derived  from 
phenyi-3-naphthylamine,  but  it  has  als»  been 
prepared  by  the  action  of  iS-naphthaquinone  on 
orthophenylonedlamine  and  bv  simultaneous 
oxidation  of  the  latter  and  jS-naphthol.  It  forms 
vonow  needles,  meltins  at  142*5*,  distilling  at  a 
nigh  temperature  without  decomposition,  and 
dissolving  in  sulphuric  acid  with  a  reddish- brown 
colouration.  On  dilution,  two  sulphates  crystal- 
lise from  this  solution.  It  is  supposed  that  the 
formation  of  two  series  of  monaoid  salts  of  this 


440 


AZINES 


base  is  dne  to  either  of  the  two  nitrogen  atoms  be- 
coming pentayaleot  and  saturated  with  the  acid. 
Totiliiaphtbadnes  CjfUitN,.  Three  sub- 
stances  of  this  formula  are  known,  the  isomerism 
of  which  has  been  discussed  by  Witt  (Ber.  20, 
677).  One  of  these,  melting  at  179*8*  has  been 
prepared  by  the  simnltaneoos  oxidation  (Ber. 
19,  917)  of  orthotolylenediamins  and  /l-naph- 
thol  (methods  6  and  7).  Its  oonstitation  is 
expressed  by  the  formula 


It  dissolves  in  sulphuric  acid  with  a  violet  oolonr- 
ation.  The  other  is  formed  by  the  decomposition 
by  acids  of  the  aco-  derivatives  of  paratolyl- 
/3-naphthylamine  (Ber.  20,  677)  (method  8). 
Its  constitution  is  represented  by  the  formula 


Its  melting-point  is  169*;  its  sulphuric  aold 
reaction  is  similar  to  that  of  naphthaphenazine. 
The  third  tolunaphthazine,  -  discovered  by 
Hinsberg  (Annalen,  237,  34da,  371)  (method  3), 
has  been  proved  to  consist  of  a  molecular  com- 
bination of  the  two  preceding  ones :  its  meltins- 
point  is  139*-142*. 

Several  other  tolunaphthazines  are  theore- 
tically possible.  They  have  not»  however, 
hitherto  been  prepared. 

Dloapbthazines  C,oHitN,.  It  hss  already 
been  stated  that  Laurent's  mysterious  <  naph- 
thase,'  prepared  by  method  1,  finally  proved  to 
be  dinaphthazine.  It  is  probable  that  Lauient's 
product  was  a  moleculu  combination  of  two  of 
the  four  isomeric  dinaphthazines  foreseen  by 
theory.  A  similar  mixture  may  be  obtained 
by  reacting  with  o^-QAphthylenediamine  upon 
iS-naphthaquinone  (method  2).  This  method 
was  used  by  Witt  in  his  identification  of 
Laurent's  'naphthase'  (Ber.  19,  2791).  For 
preparing  the  constituents  of  this  mixture  in  a 
pure  state  the  synthetical  method  8  should  be 
resorted  to ;  it  consists  in  the  decomposition  of 
the  azo-  derivatives  of  the  two  isomeric  (a,  fi,  and 
/3/3)-dinaphthylamhies  (Matthes,  Ber.  23,  1329 
and  1333).  The  compounds  thus  obtained 
have  the  following  constitutions  and  melting- 
points  :— 


The  two  other  possible  isomerides : 


tkfi,fi,fi.    DLp.  240P 

may  be  obtained  from  /9i3-naphthylenedTamine 
by  the  reaction  of  the  two  orthonaphthaquinonee 
(method  2),  but^  so  far,  only  the  imrmmetrioal 
one  has  been  prepared  by  Otto  Iischer  and 
Albert  (Ber.  29,  2087). 

Aitnei  of  the  Phenanthreno  gronii.  Owing 
to  the  extreme  facility  and  precision  with  which 
phenanthraquinone  acts  upon  all  orthodiamines, 
these  azines  are  most  easily  prepared,  and 
phenanthraquinone  is  commonly  used  for 
decidinf[  the  question  whether  any  siven 
aromatic  diamine  is  an  ortho-  compound  A 
large  number  of  azines  has  thus  become  known, 
of  which  only  a  few  may  be  described  as  typical 
representatives  of  the  group. 

Phenanthraphenaiine  CtoHi,Nt  (isomerio 
with  dinaphthazine)  may  be  obtamod  by  acting 
on  orthophenylenediamine  with  either  |^eii- 
anthraquinone  in  an  acetic  aoid  solution  (Hins- 
berg, Annalen,  237,  340),  or  with  phenanthra- 
(^uinone  sodium  bisulphite  in  an  aqueous  solu- 
tion (method  2).  It  crystidlises  in  psle-yellow 
needles,  meltinjs  at  217*,  and  dissolves  m  sul- 

{ihuric  acid  with  a  beautiful  red  colouration, 
ts  constitution  is 


•,*ffi,fi.    m.p.  28SO-884®       e, /3. /5.  «.    m.p.  242°-24r. 


A  similar  substance  may  be  obtamed  from 
orthotolylenediamine.     It  melts  at  212*-213*. 

Phenanthranaphthailne  CnHi^Na  is  easily 
obtained  (Lawson,  Ber.  18,  2426)  from  ortho- 
naphthylenediamine  and  phenanthraquinone 
(method  2).  It  gives  a  violet  colouration  with 
sulphuric  acid.  M.p.  273*.  The  sulphonic 
acid  derivatives  of  this  substance,  C,4H|,Ns- 
SO3H,  are  obtained  (Witt,  Ber.  19,  1719 ; 
21,  3485  seq.)  by  acting  with  an  aqueous 
solution  of  phenanthraquinone  sodium  bisul- 
phite upon  the  solutions  of  the  various  naphthyl- 
enediamine sulphonic  acids  in  sodium  acetate 
solution,  acidulated  with  acetic  acid.  These 
sodium  salts  are  soluble  in  pure  water;  very 
small  quantities  of  alkaline  salts  are  suifioient 
to  precipitate  them  from  these  solutions. 

Chr^toluazine  Cs.H|,Nt  and  ChiyBonaphQi- 
azine  C|aH,,N,  have  oeen  prepared  by  Lieber- 
mann  and  Witt  (Ber.  20,  2442)  from  chryso- 
quinone  and  the  corresponding  orthodiammes 
(method  2).  The  same  authors  obtained  asine 
derivatives  from  the  ouinone  of  pioene. 

Tolustilbazine  C,iH,,N|  was  discovered  by 
Hinsberg,  who  described  it  under  the  somewhi^ 


AZINBS. 


441 


misleading  name  '  Biphenyltoluquinozaline ' 
(Annalen,  237,  339).  It  is  typical  of  the  many 
azines  which  may  be  obtained  b^  the  aotioQ  ii 
benidl  upon  aromatic  orthodiammes. 

It  separates  in  silvery  leaflets  from  an 
alcoholic  solution  of  bensil  mixed  with  a  solution 
of  oithotolylenediamine  (method  2).  It  melts 
at  111*,  and  dissolves  with  a  crimson  shade  in 
sulphuric  aoid.  Its  oonstitntion  is  expressed  by 
the  formula 


The  corresponding  derivative  of  orthonaph- 
thylenediamine  was  prepared  by  Lawson  (Ber. 
18,  2426). 

T^luindadne  CifHi^N,,  the  azine  derivative 
of  isatine,  has  been  prepared  by  Hinsberg 
(Annalen,  237,  344)  from  orthotolylenodiamine 
and  isatin,  by  meltins  together  the  ingredients 
(method  2)  and  crystaljQsinff  the  product  obtained 
from  a  mixture  of  alcohol  and  acetic  acid.  It 
forms  yellow  needles,  melting  at  290^  and  dis- 
solving in  acids  with  a  brownish-red  colouration. 
Its  constitution  is  expressed  by  the  formula 


A  laige  number  of  other  less  important  asines 
have  been  prepared  in  experiments  made  with  a 
view^  to  showing  that  certain  compounds 
obtained  by  the  authors  were  either  orthodike- 
tones  or  orthodiamines. 

n.  Colouring  matteis  derived  from  aitnes 
(eurhodines  and  eoihodols). 

It  has  slready  been  said  that  by  the  intro- 
duction of  an  auxochromic  group,  NH,  or  OH, 
into  the  molecule  of  an  azine,  the  latter  is  trans- 
formed into  a  colouring  matter.  The  amino- 
derivatives  of  azines  containing  either  one  or 
several  amino-  groups,  are  embraced  by  the 
generic  name  of  eurhbdines,  whilst  the  name  of 
eurhodoU  has  been  given  to  the  phenolic  (OH) 
derivatives  of  the  azines.  The  following  is  an 
enumeration  of  the  various  methods  by  which 
eurhodines  and  eurhodols  have  been  obtained : — 

A.  EVBHODDnS. 

1.  By  heating  together  any  crthamino-azo- 
compound  and  the  hydrochloride  of  certain 
aromatic  monoamines,  such  as,  for  instance, 
a-naphthylamine  or  a-aminoquinoline,  preferably 
in  a  phenol  solution,  monoamine -azines  (the 
eurhodines  proper)  are  obtained.     It  was  by  this 

Erocees  that  the  first  eurhodine  was  discovered 
y  Witt  in  1883  (Ber.  18,  1119 ;  19,  441)  by 
heatinff  orthaminoazotoluene  with  naphthyl- 
amine  hydrochloride.  In  this  reaction  an  ortho- 
diamine  is  formed  by  the  reduction  of  the  amino- 
azo  compound,  which  combines  with  o-naphthyl- 
amine,  hydrogen  being  eliminated  and  absorbed 
by  the  amino-azo-  compound  still  present. 

drtoocolylaiie-  a-Kaphthyl-  Typical 

diamine  amme.  enrhodlne. 


2.  Another  method  of  much  greater  applica- 
bility consists  in  reacting  with  a-diketones  upon 
aromatic  triamines,  which  contain  two  ammo- 
groups  in  the  ortho-  position.  Two  molecules 
of  water  are  eliminated  for  every  molecule  of 
eurhodine  formed.  Thus,  for  instance^  a  eurho- 
dine was  obtained  from  triaminobeniene  and 
phenanthiaquinone  (Witt,  Ber.  19,  446)  i 


NH^ 


+  2H|0. 


8.  Another  method  of  considerable  applica- 
bility consists  in  heating  together  nitroso-amines 
(Witt,  Ber.  21,  719)  or  quinonedichlorimides 
(Nietzki  a.  Otto,  Ber.  21,  1698)  with  aromatic 
amines  in  which  the  para-  position  to  the  amino- 
^up  is  occupied  b^  some  radicle.  Thus,  for 
instance,  a  eurhodme  is  formed  by  heating 
together  nitrosodtmethylaniline  hydrochloride 
and  /S-OAphthylamine,  in  an  aoetio  aoid  solution  t 

Ha 

N(CH,), 


8 


^-Naphthylamine. 


NitfctodlmethylaniUne 
hydrochloride. 

Ha 

(CH,),Nv^ 


Ha 

(CH,),N 


^ 


+  8H,0  + 


\  y\  /  Paraphenytonedime- 

\X   \/  thyldlamlns  mooo- 

DlmsthyUminooaphthaphen*  hydroehlorlde. 
azine  hydrochloride. 

and  an  analogous,  though  somewhat  different 
reaction  takes  place  if  the  nitrosodimethylaniline 
be  substituted  by  dichloroquinonimide. 

a 


"•"XX) 


DlobloioquinoDlmlde. 


442 


AZ1NES. 


+  2HCL 


AminooftphUiapheiuuine. 

4.  Eurhodines  proper  may  also  be  obtained 
b^  the  reduction  (with  ammonium  sulphide)  of 
nitro-azinet.    Thus,   for   instance,   nitropheno- 

Shenanthrasine  may  be  reduced  into  the  eurho- 
ine  aminophenophenanthrasine  (Heim,  Ber.  21, 
2306). 

0.  If  certain  azo-  colours,  such  as  chiysoldine, 
be  heated  with  /l-naphthol,  an  eurhodine  is 
formed :  (Ullmaon  and  Ankersmit,  Ber.  38, 1812) : 


:oAA/ 

^Ni^thoL 


OhryBoldine. 


+C,H,NH2+H,0 


Bnrhodins. 

6.  Diaminoazines  are  formed  by  the  de- 
composition of  certain  indamines  when  their 
solutions  are  boiled  for  a  certain  time.  Thus 
tolylene  blue,  the  indamine  produced  by  the 
action  of  nitrosodimeth^laniline  hydrochloride 
upon  metatolylenediamme,  ii  decomposed  if 
its  solution  be  boiled  for  some  time,  dimethyldi- 
aminotoluphenazine  (tolylene  red)  being  the 
principal  product  of  this  reaction  (Witt,  Ber. 
12,  031) : 


nS5«'HCJ1    N^«Ha 


GH 


|CH, 


NH 

i 


•H, 


NH, 

CSHg 


xCH« 
I  CH, 


I 

CH, 

TolylMM  bfais.      Leuootolylsae  bins.     Tolylena  red 

(dimethyldiamiDC^ 
totaphenaiine). 

7.  Di-andpolyamino-aiincimayalaobepre- 


I  pared  by  the  oxidation  of  orthodiamines  and  of 
polyamines  containing  two  amino-  gruura  in  the 
ortho-  position.  Urns  O.  fischer  and  &.  Hepp 
proved  (Ber.  22,  356)  thai  the  red  substance 
which  is  formed  by  the  oxidation  of  orthophenyl- 
enediamine  and  which  has  been  observed  bv 
many  investiflaton  (Griess,  Ber.  fi,  202;  Sal- 
kowski,  Anniuen,  173,  08;  Rudolph,  Ber.  12,' 
2211 ;  Wieringer,  Annalen,  224,  363),  is  nothine 
else  than  diaminophenazine.  And  Nietski  and 
Mfiller  obtained  (Ber.  22,  447)  by  oxidising 
tetra-aminobenzene  with  a  current  of  air  tetra- 
aminophenazine.  Aminooxyphenazines  may 
sometimes  be  found  as  by-products  in  this 
reaction  (Ullmann  and  Kauthner,  Ber.  36, 
4302  and  ibid.  30,  4026). 

B.   EUBHODOLS. 

These  may  likewise  be  prepared  by  varions 
methods. 

1.  The  sulphonio  adds  of  azines,  fused  with 
potash,  readilyyield  the  corresponding  oxyazines 
or  eurhodols  (Witt,  Ber.  19, 2791).   For  insUnoe : 

C,«H„N/?0,Na+2NaOH 
Sodium  naphthaptwnanthrarinewilphonate. 

-C„H„N,ONa+Na^O,. 
PhoiaBttaraiiapbtliaeiirhodol. 

2.  Several  eurhodines  (amino- azines)  yield 
the  corresponding  eurhodol  on  being  heated 
under  pressure  with  strong  acids,  a  hydrolysas 
taking  place  in  the  oiroumstanoes  (Witt»  Ber. 
19,  4U) : 

C„H.,N,-NH,+H,0— NH,-|-Cj,H„N,OH. 
lyplcal  eorbodlDA.  SurhodoL 

3.  Diszo-azines,  on  beini;  boiled  with  water, 

G'eld  the  corresponding  eurhodols;    on  being 
>iled  with  alcohol  they  yield  the  alkyl  ethers 
of  these  eurhodols  (Witt,  Ber.  19, 444) : 

C,^H„N,N  I  N-a+H,0 
Diaxosuriiodhis  chloride. 

-Ha+N,-f  C,  tH„N,OH. 
SmhodoL 
Ci,H,iN,N :  N-a+C,H,OH 

.  -Ha+N,+C„H„N,OC,Hg. 
Bthylevrhodol. 

The  following  is  an  enumeration  of  those  of 
the  eurhodines  and  eurhodols  which  have  been 
more  closely  investigated,  the  properties  of 
which  are  typical  for  the  whole  class  of  colouring 
matters : — 

Typical  eorhodlno  CitHi,N,  (Witt,  Ber.  10, 
446).  The  mode  of  formation  of  this  substance 
has  already  been  ^ven  (Section  A,  1).  It  is  best 
prepared  by  heating  to  130*  equal  molecules  of 
orbhoaminoazotolueno,  of  the  meltixig-point 
118*5*,  and  a-naphthylamine  bydrochloriae,  dis- 
solved in  phenol  until  the  colour  of  the  mix- 
ture, which  is  at  first  of  an  emerald  green,  has 
changed  into  a  briUiant  scarlet.  The  mixture  is 
now  treated  with  a  large  quantity  of  toluene, 
when  the  hydrochloride  of  the  new  dyestnff  is 
precipitated  in  a  crystalline  state.  By  reoiyatal- 
lisation  from  water  acidified  with  hydrochloric 
acid,  it  may  be  obtained  in  a  pure  state.  From 
the  pure  hydrochloride  the  free  eurhodine  base 
is  precipitated  by  alkalis  or  ammonia  in  the 
form  of  a  yeUow  powder^  which  may  be  re- 
crystallised  from  aniline.  Thus  prepared,  it 
forms  glisteninff  yellow  prisms  and  needles  of  a 
dark-brown  c<w>ur.  It  dissolves  in  ether  with 
a  yellow  colour  and  a  magnifibent  green  fluoiea- 
oenoe,  ividoh  is  oharaoteristio  of  all  the  membect 


AZINES. 


443 


ot  Hub  group  of  dyestufft.  Eurhodine  forms 
three  aeriee  of  aalts*  of  which,  however,  only 
thoae  with  one  moleoole  of  add  are  fairly  stable, 
whilst  those  containing  more  acid  are  decom- 
posed by  the  addition  of  water.  It  is  to  the 
formation  of  these  ▼arions  salts  that  the  peculiar 
change  of  colour  is  due  whtch  ia  observed  on 
adding  water  to  a  solution  of  eurhodine  in  con- 
centrated sulphuric  acid.  This  solution  is  of  a 
cherry-red  colour.  On  adding  a  small  quantity 
of  water  the  colour  changes  to  a  fine  emerald 
green,  whilst  still  more  water  produces  the 
scarlet  shade  of  the  normal  sulphate^  This 
change  of  colour,  which  is  observed  with  all  the 
eurhmUnes,  links  them  to  thoir  parent-sub- 
stances, tlie  azines,  which  exhibit  similar 
curious  phenomena,  and  also  to  the  safraninee. 

The  normal  salts  of  eurhodine  are  well 
crystallised  and  of  a  bronzed  copper  odour  when 
solid.  In  solution  they  exhibit  a  bright  scarlet 
tint  which  they  communicate  to  the  fibre. 
These  normal  salts  are,  however,  psrtially  de- 
composed by  an  excess  of  water,  the  free  eurho- 
dine base  Ming  regenerated.  The  same  takes 
place  if  fibres  dyed  rod  with  eurhodine  be  washed. 
The  scarlet  shade  is  gradually  replaced  by  the 
yellow  shade  of  the  free  eurhodine  base.  For 
this  reason  eurhodine  has  not  found  an  applica- 
tion in  the  industry  of  artificial  dyestuffs. 

Amlnonaphthapheiiaiine  CigHjiN,  has  been 
obUined  bv  Nietzki  and  Otto  (Ber.  21,  1698) 
from  /9-naphthylamine  and  dichloroquinonimide 
(Ullmann  and  Ankersmit,  Ber.  38,  1811).  It 
omtallises  in  dark-yellow  needles.  Its  salts  are 
of  a  crimson  colour.  Its  solution  in  «iiIphurio 
acid  changes  by  the  addition  of  water  from  red- 
dish-brown through  ffn&a  into  red.  It  forms  a 
diaio-  compound  which,  when  boiled  with  alco- 
hol, yields  the  ordinary  naphthapbenazine,  of 
the  melting-point  142*6*.  The  following  com- 
pound is  its  dimethyl  derivative : — 

DbnefhyUunlnonaphtlUipheDaxIna  C,sH,,N, 
(THtt,  Ber.  21, 719).  This  eurhodine,  the  forma- 
tion of  which  has  been  described  under  Section  A, 
3,  may  easily  be  prepared  in  quantity  by  heating 
together  20  parts  nitrosodimethyUniUne  hydro- 
chloride and  10  parts  3-n*phthylamine  with 
60  glacial  acetic  acid;  the  reaction  sets  in 
below  100*,  and  is  apt  to  become  violenU  The 
product  changes  to  a  fine  violet  colour.  It  ii 
dissolved  in  water  acidified  with  hydrochloric 
acid,  and  the  filtered  solution  isprecipitated  by 
the  addition  of  sodium  acetate.  Tne  crude  eurho- 
dine Tdiich  is  thus  precipitated  may  be  purified 
bv  dissolving  it  in  alcohol  acidified  with  hydro- 
chloric acid.  From  this  solution  the  normal 
eurhodine  hydrochloride  crystallises  in  bronse- 
coloured  needles.'  Trom  these  ammonia  liberates 
the  free  eurhodine  base  in  the  form  of  a  scarlet 
crystalline  powder.  It  may  be  recrystaDised 
from  boiling  xylene;  it  is  thus  obtained  in 
ma^flcent  otystals  resembling  magnesium- 
platinocyanide»  melting  at  206*. 

The  change  of  colour  of  a  sulphuric  acid 
solution  of  tms  eurhodine  is  not  very  marked, 
going  from  violet  throush  black  and  green  into 
violet.  The  ethereal  s^ution  of  tiie  free  base 
exhibits  the  brilliant  fluorescence  characteristic 
of  all  enrhodines. 

AminophaiuiplMiuuilhraifaie  0,oH|,N,.  This 
eurhodine  was  prepared  by  Witt  (Ber.  19,  446) 
and  by  Heim  (Ber.  21.  £K)6)  by  the  methods 


given  under  Section  A,  2  and  4.  It  orystaUisee 
mm  toluene  in  ahoit,  thick,  yellow  prisms^ 
melting  at  279*. 

Dlm«tliyldlamlnotohiplMDailii«;  TolytoM  red 
Gi|H|«N4.  The  formation  of  this  compound  by 
the  spontaneous  decomposition  of  tolyiene  blue 
has  been  described  unaer  Section  A,  6.  This 
eurhodine  forms,  in  a  pure  state,  orange  crystals, 
which  contain  4  mols.  of  water  of  crystallisation  ; 
at  160*  this  is  given  off  and  the  annydrous  base 
remains  as  a  dark-red  powder.  The  h3rdrsted 
base  is  soluble  in  ether  with  a  pink  colour  and  a 
beautiful  orange  fluorescence.  The  solution  in 
concentrated  sulphuric  acid  is  neen  ;  on  being 
diluted  with  water  it  changes  through  sky-blue 
into  red.  The  normal  (monacid)  salts  arc 
perfectly  stable  and  soluble  in  water  with  a 
pfaik  colour.  This  solution  dyes  unmordanted 
or  mordanted  cotton  and  other  fibres  a  pink 
which  in  darker  shades  deepens  into  a  coppery 
fed. 

The  production  of  this  dyettuff  has  been 
patented  (Otto  N.  Witt,  D.  R.  P.  16272; 
£ng.  Pat  4846, 1880).  The  commercial  product, 
which  contains  a  certain  amount  of  impurities, 
is  sold  under  the  name  of  *  neutral  red.*  It  is 
chiefly  used  in  calico-printing,  and  gives  very 
fast  and  useful  shades. 

A  similar  product  is  prepared  from  the  in* 
damine  which  is  formed  by  reacting  with  nitroso- 
dimethylamine  hydrochloride  upon  metaphenyl- 
enediamine.  It  is  embraced  by  the  same  patent 
and  sold  under  the  name  of  *  neutral  violet.' 

Typical  enrhodol  Ci^EuVfiK  (Witt,  Ber. 
19,  444).  This  substance,  the  formation  of 
which  takes  place  according  to  the  equation 
given  under  Section  B,  2,  forms  small  leaflets  of 
a  yellow  or  red  colour  which  dissolve  in  con- 
centrated sulphuric  acid  with  a  red  colouration, 
and  are  reprecipitated  from  this  solution  by  the 
addition  oi  water.  Caustic  soda  solution  dis- 
solves it  with  an  orange  shade.  Thus  it  is  shown 
that  this  eurhodol  (Bke  all  oompounds  of  the 
same  class)  exhibits  both  acid  and  basic  pro- 
perties, the  latter  being  due  to  the  asine  group 
contained  hi  their  molecule. 

Eurhodol  0,«Hi4N,0H.  a-Hydioxynaphtha- 
phenanthrazine  has  been  obtained  (Witt, 
Ber.  19,  2791)  by  the  method  described  under 
Section  B,  1,  by  the  fusion  of  naphthaphen- 
anthrazine-a-sulphonic  acid  with  caustic  alkalis. 
Its  solution  in  sulphuric  acid  is  of  a  fine  and 
intense  indigo-blue ;  it  changes  very  suddenly 
mto  red  on  the  addition  of  water,  the  sulphate 
being  precipitated.  This  substance  is  a  yellow 
colounng  matter  which  may  be  fixed  on  cotton 
with  alum-mordant,  like  alizarin.  OwinA,  how- 
ever, to  its  costliness,  it  has  not  been  brought 
into  commerce.  A  large  number  of  isomerides 
may  be  prepared  by  starting  from  the  numerous 
sulpho-  aenvatives  of  orthonaphthylenediamine, 
tranrforming  them  into  azinesulphonates  by 
condensation  with  phenanthzaquinone  and  into 
eurhodols  by  subsequent  fusion  with  oanstio 
alkalis. 

IIL  Aiontam  bases  and  latraiiliiii.  The 
azonium  bases  are  a  dass  of  compounds  of  which 
our  knowledge  is  very  restricted,  very  few 
representatives  of  the  class  being  at  present 
known,  and  thai  rather  imperfectly.  They  are, 
however,  of  importance,  as  it  is  now  estabushed 
beyond  doubt  that  thoy  are  the  parent  sub- 


444 


A2lNffi. 


stances  of  the  yeiy  important  class  of  dyestafifs 
known  as  satenines.  Although  the  fint 
artificial  dyestiifl^  maavdne,  was  a  tme  safra- 
nine,  and  altiiongh  this  aron^  of  compounds 
has  been  frequently  vnoer  investigation*  a 
oorreot  view  of  their  constitution  had  not  been 
obtained  until  quite  recently.  Aoooiding  to 
the  theory  now  universally  adopted,  all  safra- 
nines  are  amino-  derivatives  of  aaoninm.  bases, 
to  which  they  stand  in  the  same  relation  as  the 
enrhodines  to  the  azines.  Hydroxy-  derivatives 
of  azonium  bases  have  also  been  prepared  and 
described  under  the  name  of  safnnols.  They 
are,  however,  of  no  importance  as  colouring 
matters. 

The  aconium  bases  themselves,  none  of 
which  has  so  far  been  obtained  in  a  state 
fit  for  analysis,  stand  in  the  same  rriation  to  the 
axines  as  the  ammonium  bases  to  the  amines. 
They  are  axines  in  which  one  of  the  nitrogen 
atoms  has  become  pentavalent  by  being  satu- 
rated with  three  organic  radicles  and  one  acid 
radicle,  the  connection  with  the  second  nitrogen 
atom  being  still  preserved  by  the  fifth  vslenoy 
of  the  pentavalent  nitrogen  atom.  Thus  the 
characteristic  constitution  of  the  azonium  com- 
pomida  may  be  expressed  by  the  general  formula 

Rn<    I      >Rn 


in  which  Ri  and  RQ  represent  mono-  and 
divalent  organic  radicles,  and  X^  a  monovalent 
acid  radicle.  The  azonium  bases  are  compounds 
which  possess  strong  basic  properties,  and  which, 
by  t^e  tenacity  with  which  they  retain  their 
acid  radicle,  strongly  resemble  the  ammonium 
bases.  It  is  probable  that  the  free  azonium 
bases  contain,  like  the  ammonium  bases,  the 
hydroxyl  group  in  the  position  Xi  of  the  above 
general  formula.  The  azonium  bases  and  the 
dvestuib  derived  from  them  are  also  capable 
of  tautomeric  changes,  which  lead  to  their 
assuming  quinonoid  structures.  The  nature  of 
these  changes  is  in  many  oases  doubtful  and  too 
complicatea  to  be  fully  discussed  in  this  article. 

The  azonium  bases  are  strongly  coloured 
substances,  but  their  dyeina  properties  are 
developed  and  brought  to  pconection  by  the  in- 
troduction of  amino-  groups  into  their  molecule. 
As  the  azonium  bases  theoretically  possible  are 
very  numerous,  and  each  of  them  is  capable  of 
producing  very  numerous  isomeric  mono-  and 
polyamino-  derivatives,  the  number  of  possible 
safranines  is  exceedingly  large,  and  the  number 
of  those  which  have  already  been  prepared  is 
insisnificant  in  comparison  with  that  fore- 
shaaowed  by  theory. 

Of  the  safranmes  which  have  hitherto  been 
prepared,  only  a  few  are  monoamine-  derivatives 
of  azonium  bases.  A  few  more  are  of  doubtful 
or  unknown  constitution.  The  majority  are 
asymmetric  diamine-  derivatives  of  azonium 
bases,  containing  one  amino-  group  in  one  of 
the  diatomic  organic  radicles  {BJ^  whilst  the 

other  is  attached  to  the  monoatomic  radicle  (Ri). 

The    true    constitution   of    phenosafraniae 

and  its  congeners  has  been  recognised  by  Witt, 

who,  after  pointing  out  the  analogy  between  the 


curhodines  and  safranines  (Ber.  18,  1119)  and 
dearinff  up  the  constitution  of  the  former  (Ber. 
19,  44o),  proved  the  latter  to  be  asymmetric 
diaminoazonium  bases  (Ber.  19,  3121).  Bemth- 
sen  had  proposed  (Ber.  19,  2690)  somewhat 
earlier  a  sjrmmetrical  formula  for  the  safranines 
based  upon  ^^itt's  enrfaodine  researches.  His 
view  was  subseqneiitly  adopted  bysomechemists. 
but  the  author  of  tliis  arti<ue  fails  to  see  the  force 
of  the  aiguments  adduced  in  support  of  it.  C/. 
supplementary  artiola. 

JL  Aionlioil  bafit.  L  The  tjrpical  compoond 
was  obtained  by  Witt  (Ber.  20,  1183)  by  the 
reaction  of  phenanthraquinone  on  phenylOTtho- 
naphthylenediamine.  ^y  heating  these  ingre- 
dients in  an  acetic  acid  solution  an  inter- 
mediate product  is  obtained,  which  on  treat- 
ment witn  a  mineral  acid  is  transformed  into 
the  salt  of  the  azonium  base : 


If  nitric  acid  is  used,  the  nitrate  is  deposited 
in  very  fine  crystals.  It  is  sparingly  soluble  in 
water,  readily  soluble  in  spirit  with  a  fine 
orange-red  colouration.  The  nydrochloride  dis- 
solves in  sulphuric  add  with  a  violet  tint^  which 
changes  into  red  on  dilution  with  water. 

2.  If  in  this  reaction  the  phenylorthonaphthyl- 
enediamine  be  replaced  by  phen^ortho- 
phenylenediamine,  the  reeultins  compound  is 
a  yeuow  dyestuf!  of  considerable  strength.  It 
is  manufactured  and  sold  under  the  name 
'  Slavinduline '  (1893). 

3.  A  very  similar  compound  was  obtained 
by  Otto  N.  Witt  and  Christoph  Schmidt  in 
1892  (Ber.  25,  1017),  by  the  reaction  of  benzil 
upon  ethorTphenylorthonaphthylendiamine.  It 
was  called  ethoxyphenymaphthostflbazoninm 
chloride  and  has  the  constitution : 

C.H, 


(i 


It  is  a  beautiful  yellow  dyestuff,  but  too 
expensive  to  be  prepared  on  a  manufacturing 
scale. 

B.  Safranines.  The  various  colouring  mat- 
ters beloDginff  to  this  group  have  mostly  been 
prepared  by  different  synthetical  methods,  which 
may  be  classed  in  the  following  manner  :-— 

1.  Reduction  of  the  nitro-  derivatives  of 
azonium  bases.  By  reacting  with  mononitro- 
phenanthraquinone  or  dinitrophenanthra- 
quinone     on     phenylorthonaphthylenediamine. 


I 


AZTNES. 


440 


nitro-  and  diiutio-  deriTatiYM  of  the  above 
aaoniiuii  baae  are  obtained,  which  on  rednotion 
with  ammonium  snlphide  yield  reddish-violet 
ooloariziff  matten  belonfling  to  the  safranina 
group  (Witt,  nnpnbliahed  obeemrations). 

2.  U  the  stilbaxoninm  baae  obtained  by 
Witt  and  Schmidt,  or  any  of  ita  conflenerB 
prepared  from  ethylated  arylorthona]^thyl- 
eneidiaminee  be  heated  with  ammonia,  the 
ethozy  group  la  repUoed  by  the  amino-  group 
and  the  oorreaponding  aafnninea  are  formed. 
Thia  ia  quite  a  general  reaction  (Witt  and 
Schmidt,  Ber.  26,  2003 ;  Witt  and  v.  HeLnolt^ 
Ber.  27,  2366 ;  Witt  and  Buntrook,  Ber.  27, 
2362). 

3.  By  the  action  of  dichloroquinonimidea 
upon  aecondary  aromatic  aminea,  in  whioh  the 
para-  poaition  to  the  amino-  group  is  occupied, 
monoamino-asonium  baaea  are  formed  (Nietsid 
and  Otto,  Ber.  21,  1696).  The  reaction,  for  In- 
atance^  beitween  dichloroauinonimide  and  phenyl- 
/9-naphthylamlne  may  be  represented  oy  the 
equation : 


\An 


XX) 


Phanyl-^Qaiithttiylainliie. 


DtohloroqnhKnBiniMe, 


-  Ha  +    ^JL/ 


Kewdyestufl. 

4.  In  a  aimilar  manner  nitroaodimeth^l- 
aniline  (or  any  other  nitroso-amine)  reaota  with 
phfliiyl.i|.nnphthylamine  (Witt,  Ber.  21»  719): 

Hd 

N(CH,), 


+  8       -       N> 

/ 

PhfiDyl-^-naphthylamlnn. 


mtroiodlmattiylaiilUne 
hydrochlnridet 


(CH,)^- 


Ha*N((}Ha), 
-f3H,0+ 


ITew  dyeatufl. 


Dimethylparaphenyl- 
enediamine  mooo- 
lur4roctilarld9. 


I  6.  The  aafraninea  proper  (aaymmetrio  di- 
aminoazonium  baaea)  are  formed  by  the  joint 
oxidation  of  one  molecule  of  diamine  and  two 
moleculeB  of  an  aromatic  monoamineii  In  thja 
reaction  fugitive  indaminea  are  formed  aa  inter- 
mediate producta;  the  proceaa  thua  becomaa 
■teictly  analogoua  to  the  formation  d  toluylene 
red  and  ita  congenera. 

Thia  ia  the  proceaa  which  ia  generaDy  uaed 
in  the  manufacture  of  aafraninea,  and  it  will 
therefore  be  fully  explained. 

B^  the  joint  oxidation  of  an  aromatio  para* 
diamme  with  one  molclbule  of  an  aromatio 
monoamine,  an  indamine  ia  invariably  formed 
(p.  Ikdaiumxb).  If  theae  indaminea  be  oxidiaed 
in  the  preaence  of  another  molecule  of  an 
aromatio  monoamine,  a  aafranine  ia  formed  i 

lint  Stage. 


NH, 


+      11    +0,-    N 


+2H^. 


Second  Stage. 


Ha 
NH, 


1.  +rS 


•i-20-2H.O+ 


R 

0 

!l 
NH 

hdamlna. 


Aniline 
hydrochlorida. 


fH. 
RMnoaafranlna. 


Of  courae^  any  other  paradiamine  may  be 
aubatituted  for  parapheoylenediamine,  and  any 
other  monoamine  for  aniline.  Aa,  however,  the 
formation  of  an  indamine  only  takea  place  if  the 
para-  poaition  to  the  amino-  group  he  atill  free, 
it  reaulta,  that  at  leaat  one  of  the  two  moleculea 
of  monoaminea  must  fulfil  this  condition.  Thua 
the  formation  of  a  aafranine  from  paraphenyl- 
enediamine  takea  place  on  oxidation  of  one 
molecule  of  the  diamine  with 

(1)  Two  moleculea  of  aniline. 

(2)  Two  moleculea  of  orthotoluidine. 

(3)  One  of  aniline  and  one  of  orthotoluidine. 

(4)  One  of  aniline  and  one  of  paratoluidine. 

(6)  One  of  orthotoluidine  and  one  of  para- 
toluidine ;  but  it  doea  not  take  place  with  one 
molecule  of  paraphenylenediamine  and  two  of 
paratoluidine  (Witt,  J.  Soc.  C3iem.  Ind.  1882, 
266). 

On  the  pther  hand,  tbc  other  of  the  two 


446 


AZINBS. 


molecules  of  monoaminet  must  have  a  free  ortho-  j 
pofii  tiou  in  order  to  be  capable  of  entering  the 
reactioQ.  Thus  the  indamine  of  the  aoove 
formula  forma  cafranines  with  all  the  primary 
aromatic  monoamlaes  of  the  benzene  aenee,  with 
the  exception  of  one  zylidine  and  of  mesidinct 
of  the  reepoctive  formula* 

ch/\ch.     ^^^     ch/\ch. 


NH. 


because  these  two  have  no  free  ortho-  position  to 
be  used  for  the  formation  of  the  azonium  group 
(l^ietdd,  Ber.  10,  3017  and  3136). 

It  18  also  necessary  that  this  second  molecule 
of  monoamine  be  a  primary  base,  whilst  the  one 
necessary  for  the  formation  of  the  indamine  may 
be  either  primary,  aecondar}',  or  tertiary,  pro- 
vided always  that  it  possesses  a  free  para- 
position. 

6.  It  is  evident  that  the  general  process  do- 
scribed  under  4  may  be  modified ;  thus,  for 
instance,  the  dipara-amino-  derivatives  of 
secondary  bases  (bsing  the  leuco-  compounds  of 
indamincs)  may  be  oxidised  together  with  one 
molecule  of  a  primary  aromatic  monoamine, 
when  a  safranino  is  the  result  (see  top  of  page, 
second  column) : 

7.  Another  modification  (Witt,  Ber.  10,  873) 
consists  in  heating  aminoazo-  compounds  with 
the   hydrochlorides  of    aromatic   monoamines. 


NH, 
I       1  NH,Ha 

Y     A 

NH  +^1 


NH, 


J  -i-30-3H,0+         / 


Aniline 
hydrochloride. 


Dipara-amlno- 
dlphenylamine. 


NH, 
Bafranins. 


This  is  the  oldest  process  for  the  manufacture 
of  safranines.  The  mechanism  of  this  reaction 
is  simple.  Part  of  the  aminoazo-  compound 
being  reduced,  a  mixture  of  a  paradiamine  and  a 
primary  monoamine  in  molecular  proportions  is 
formed,  which  with  the  monoamine  added  in  the 
shape  of  hydrochloride,  is  transformed  into 
safranine  by  the  dehydrosenating  action  of  the 
remaining  part  of  the  aminoazo-  compound.  It 
is  evident  that  the  yield  must  be  small  in  this 
process  of  manufacture,  and  such  is  actually 
the  case. 

8.  An  asymmetrical  safranine  has  been 
obtained  by  the  reduction  of  pioryl-ortho- 
phenylenediamine  (Kehrmann,  Ber.  33,  3074). 

9.  Certain  compounds  belonging  to  the 
safranine  group  (mauvelne,  &c.)  are  formed  in 
a  very  complicated  reaction  by  the  oxidation  of 
heavy  aniline  alone;  on  continued  oxidation 
roauvelne  is  converted  into  a  safranine  (Perkin, 
Hoy.  Soc.  Proc.  36,  717). 


The  following  is  an  account  of  the  more 
important  and  more  thoroughly  investigated 
safranines : — 

A.    MoNAMivo-  Derivatives  ov  Azonium 

Bases. 

1.  Aposafnnlne,  Monoaminophenylphenazo- 
nium  chloride,  has  been  obtained  by  Nietzki 
and  Otto  (Ber.  21,  1736;  ue  also  AnniJftn, 
286,  188,  and  Ber.  30,  2624,  and  33,  3078)  from 
phenosafranine  (see  below)  by  diaaotising  one 
of  its  amino*  groups,  and  eliminating  it  by 
means  of  alcohS.  It  is  a  red  dvestulf  of  no 
practical  importance,  but  very  mteresting  as 
prototype  of    the   induline   group   {see   under 

1NDULINE8). 

2.  Red  dyestuff  C(,H,,N,C1  Obtamed  bv 
the  action  of  dichioroquinonimide  on  phenyl- 
/3-naphthylamine,  was  prepared  by  Nietzki  and 
Otto  (Ber.  21, 1598)  by  heating  the  ingredients  in 
moletsular  proportion  in  alcoholic  solution  on 
the  water-bath.  The  nitrate  forms  green  needles 
or  prisms  which  are  soluble  in  water  with  a 
magenta-red  colour.  The  hydrochloride  dis- 
solves in  sulphuric  acid  with  a  red  colouration, 
which  on  dilution  changes  through  green  into 
red. 

3.  Violet  eolouring  matter  C,4H„N,GL  Pre- 
pared by  Witt  (Ber.  21,  719)  by  acting  with  3 
moleculefl  of  nitrosodimethyUniline  hydro- 
chloride in  an  acetic  acid  solution  on  2  molecules 
of  phenyl-iS-naphthylamine.  This  is  the  di' 
nietnyl-  derivative  of  the  preceding  substanoa 
The  hydrochloride  forms  la^  black  needles 
soluble  in  water,  with  a  fine  violet  colour.  The 
free  base,  0,4H2,N,*OH,  is  liberated  from  the 
salts  by  caustic  alkalis  only.  It  is  insoluble  in 
water,  soluble  in  alcohol,  with  a  red  colour  and 
a  fine  orange  fluorescence.  It  is  sold  as '  neutral 
blue.' 

4.  Violet  eolonring  matter  C„H„NaCL  Pre- 
pared by  Witt  (Ber.  21,  719)  from  paratolyl- 
3-naphthylamine  in  exactly  the  same  manner  as 
the  preceding  substance,  of  which  this  is  the 
next  homologue.  Violet  soft  needles,  resem- 
bling in  their  colour  and  reactions  the  phenyl- 
derivative. 

The  above  substances  have  been  patented 
(Otto  N.  WiU,  D.  R.  P.  19224,  dated  Feb.  18, 
1882). 

5.  Basle  blue  Ca|H,,N«a  is  a  fine  blue 
dyestuff  prepared  (T.  Annaheim,  Ber.  20, 
1371 ;  Durand  and  Huguenin,  Get,  Pat.  40886) 
by  the  reaction  of  nitrosodimethylaniline 
hydrochloride  on  the  paratolvlnaphthWene- 
diamine  which  is  formed  by  heating  Ebert 
and  Merz*s  dihydrox^Tiaphthalene  with  para- 
toluidine  hydrochloride.  It  forms  a  brown 
crystalline  powder,  soluble  in  water  with  a 
bluish-violet  shade.  In  concentrated  sulphuric 
acid  it  dissolves  vnth  a  greenish- brown  shade, 
which  changes  through  green  into  violet  on 
dilution. 

6.  Asbie  green  C,oH|sN401  is  formed  by 
the  reaction  of  nitro^odimethvlaniline  hydro- 
chloride upon  2  -  6  -  diphenylnaphthylenedia- 
mine. 

7.  Induline  searlet  Ci,Hi,N,Gl,  a  very 
beautiful  red  dyestufif  discovered  by  SchrauM 
(D.  R.  P.  77266  ;  Eng.  Pat.  10138A,  1892),  and 
manufactured  by  the  Badische  Aniline  and  Soda- 
Fabrik.  is  really  not  an  induline,  but  a  Safnuiine. 
It  is  prepared  by  melting  together  the  hydro- 


AZINE3. 


4A7 


ch'oride  of  anilliiasoethylpaimtolmdine  and  a- 
aaphthyUminfi,  The  reaction  is  strictly  analo- 
gous to  the  fonnation  of  the  typical  eurhodine. 

(Indnline  scariet  is  used  as  a  catalyst  in 
discharge  printing  in  some  cases  (c/.  D.  R.  P. 
184381).  BongaUte  speciaX  (B.  A.  S.  F.)  and 
hydrosolphite  oonc.  special  (M.  L.  B.)  both  con- 
tain induJine  soi^et. — ^F.  A.  M.) 

B.  IhjjaxO'  Dbbiyatiyxs  ov  Azohium  Basks. 

1.  Phemsalraiitaw  C^fiig^JCi.  Discovered 
by  Witt  (exhibited  in  Paris  in  1878  ;  and  men- 
tioned in  the  catalogue  of  Messrs.  Williams, 
Thomas  ft  Dower,  closely  investigated  by 
Nietxki  (Ber.  16,  464)  and  by  Bindschedler 
(Ber.  13,  207  ;  16,  865). 

It  was  with  this  compound  that  the  mode  of 
formaticm  of  the  safranines  and  their  chemical 
properties  were  definitely  ascertained,  chiefly  by 
R.  xfietzki,  whose  brilliant  researches  on  this 
subject  did  much  to  clear  up  the  chemistry  of 
this  group. 

Phenosafranine   is   prepared    by   the   joint 
oxidation  of  paraphenytonediamine  and  aniline. 
The  mechanism  of  this  process  has  already  been 
discussed.    A   dilute  aqueous  solution  of  the 
normal  hydrochlorides  of  these  bases  is  used,  and 
their    oxidation    is    accomplished    by    adding 
potassium  or  sodium  bichromate  or  manganese 
dioxide  in  the  necessary  proportion  to  the  hot 
solution.    The    blue   colour   of    the    indamine 
which  appears  at  first  is  immediately  replaced 
by  the  red  colour  of  the  safremine  formed.    A 
certain  quantity  of  insoluble  dark  by-products 
is  always  formed,  but  by  careful  work  the  yield 
of  pure  safranine  m^  be  raised  to  70  p.c.  of  the 
theory.  When  the  oxidation  is  finished,  soda  solu- 
tion or  chalk  is  added  in  order  to  precipitate  the 
imparities^  and  the  liquid  is  filtered.     By  adding 
a  small  amount  of  nitrio  acid  and  some  sodium 
nitrate  to  the  filtered  solution,  the  nitrate  of  the 
safranine  orystalliaes  out ;  or  the  chloride  may 
be  prepared  by  adding  oommon  salt  to  the  solu- 
tion after  acidifying  it  with  hydrochloric  acid. 
By   repeated   reorystalliBation   from    water   or 
alcohol  the  phenosafranine    is  obtained   in  s 
state  of  purity,  in  the  form  of  magnifloent  greon 
needles.    The  sulphate  forms  blue  needles.    The 
platinum    salt    (C|,H|.N«Cl)|Pta4   forms    in- 
soluble shining  leaflets.    Phenosafranine  forms  a 
diacetvl-  derivative  on  boiling  with  acetic  sn- 
hydrioe  in  the  presence  of  dry  sodium  acetate. 
It  forms  two  diazo-derivatives,  of  which  the 
fin! 

is  rather  stable  and  soluble  in  water,  with  blue 
colouration.    The  other  diazo-  compound 

^^N :  N€l 

C„H„N,C1 
^^N :  N<J1 

is  very  unstable  and  of  a  green  oolonr. 

Phenosafranine  dyes  wool,  silk,  and  cotton  a 
magnificent  pink.  Its  aqueous  sciutions  are  red 
and  show  no  fluoresoenoe,  whiUt  alcoholic  solu- 
tions show  a  marked  greenish-yellow  fiuor- 
esoence.  Phenosafranine  dissolves  in  con- 
centrated sulphuric  acid  with  a  green  colouration 
which  changes  through  blue  into  red  on  dilution, 


thu^  indicating  the  actual  existence  of  the  three 
series  of  salts  foreshadowed  by  theory. 

If  phenosafranine  or  its  homologues  be 
diaiotised  and  then  combined  with  i3-naphthol» 
beautiful  basic  blue  dyestuAs  are  obtained, 
which  are  largely  prepared  and  used  for  cotton- 
dyeing  and  ^ioo-prmting  under  tha  name  of 
'  Indoine  blue.* 

The  alkyl-  derivatives  of  phenosafranine  are 
interesting  colouring  matters,  some  of  which 
have  found  an  industrial  application.  Thev 
have  not  been  prepared  by  introducing  alkyl- 
sroups  into  ready-formed  safranine,  but  rather 
by  direct  synthesis  from  suitable  raw  materials. 
Eiach  of  them  exists  in  two  isomeric  modifica- 
tions, according  to  Uio  amino-  group  into  which 
the  alkyl-  group  has  been  introduced.  The  two 
amino-  groups  of  phenosafranine  being  asym- 
metric, and  therefore  not  equivalent  to  one 
another,  must  of  necessity  produce  different  pro- 
ducts on  being  alkylated. 

a-Dtmethylsatnttlne  C2«H,,N4C1  is  produoed 
by  the  simultaneous  oxidation  of  one  molecule 
ol  paraphonylenedimethyldiamine  with  two 
molecules  of  aniline. 

It  is  a  dyestuff  of  a  magenta-red  shade.  Its 
nitrate  crystolliMs  in  green  needles  (Bindschedler, 
Ber.  16,  809). 

3-Diiiietliylsatmilne  is  obtained  by  ozidining 
a  mixture  of  one  molecule  of  parajriieoylene- 
diamine  with  one  molecule  of  aniline  and  one 
molecule  of  dimeUiylaniline.  Ita  shade  is 
similar  to  that  of  the  preceding  one ;  its  nitrate 
forms  brown  leaflets  (Nietxki,  Ber.  19,  3017  and 
3136). 

The  two  dlethylsafruiliMS  are  obtained  in 
a  similar  manner.  Their  chlorides  form  green 
needles  which  dissolve  in  water  with  a  violet 
shade  (IHetaki,  Ber.  16,  464).  These  sub- 
stances, and  especially  the  «•  derivatives,  are 
manufactured  under  Uie  name  of  FucKtia, 

Tetnmethylsafnnlne  (Bindschedler,  Lc)  and 
(etnethylsatranine  (Nietxki,  Le.)  may  be  pre- 
pared by  the  joint  oxidation  of  one  molecule  of 
paraphenylenedimethyl-  (or  diethyl-)  diamine 
with  one  molecule  of  aniline  and  one  molecule 
of  dimeUiyl-  or  diethvlaniline.  These  substances 
have  been  sold  unaer  the  name  of  AmdhvH, 
Their  shade  is  a  magnificent  violet,  with  a  fine 
crimson  fluorescence.  Unfortunatdy,  they  are 
very  fugitive. 

2.  Tolusafniilliei  (Hofmann  aud  Geyger, 
Ber.  5,  526,  and  very  numerous  other  publi- 
cations) C,tH,|N|C!l.  A  mixture  of  the  iso- 
merides  of  this  formula  is  the  safranine  of 
commerce.  It  ia  prepared  by  the  oxidation  of 
a  mixture  of  paratolylenediamine  with  the  two 
toluidines.  This  mixture  is  obtained  by  treat- 
ing three  molecules  of  the  orthotoluidine  of 
commerce  (which  contains  from  6  to  10  p.c  of 
paratoluidine)  with  two  molecules  of  h^^dro- 
chloric  acid  and  one  molecule  of  sodium  nitrite 
dissolved  in  as  little  water  as  possible.  A  thick 
heavy  oil  is  the  result,  which  is  merely  a  solution 
of  amino-azotoluene  in  the  excess  of  toluidine 
present.  By  dissolving  this  oil  in  hydrochloric 
acid,  and  reducing  it  with  either  tmo-dust  or 
iron  borings,  the  amino-aso-  compound  is  split 
up  into  paratolylenediamine  and  orthoto- 
luidine; consequently,  the  ai^ueous  liquid  pro- 
duoed contains  the  bases  m  the  necessary 
proportions  for  the   production   of  safranine. 


448 


AZINES. 


The  rest  of  the  treatment  is  exactly  similar  to) 
the  one  desoribed  for  pheno-safranine.  The 
safranine  is  precipitated  from  the  liquid  by  the 
addition  of  salt.  By  redissolving  it  in  water, 
boiling  with  a  small  quantity  of  potassium 
bichromate,  treating  it  afresh  with  muk  of  lime 
or  ehalk,  and  lepreoipitating  the  filtered  liquid 
with  clean  salt,  the  safranine  is  purified  so  as 
to  give  the  brightest  shades  on  dyeing.  Safra- 
nine prepared  with  a  toluidlne  rich  in  para- 
toluidme  is  very  insolnble  in  cold  water,  and 
therefore  genenuly  disliked  by  the  dyer.  The 
presence  <ra  aniline  has  not  the  same  disagree- 
able effect:  some  manufacturers  therefore  use 
the  first  runnings  of  the  magenta  process,  which 
consist  of  aniline  and  orthotoluidine,  and  con- 
tain no  paratoluidine,  as  a  suitable  raw  product 
for  the  manufacture  of  safranine.  The  safra- 
nine of  commerce  forms  a  brown  powder  which 
dissolyes  readily  in  hot  water.   It  dyes  a  bluish- 

Sink  on  textile  fibres,  and  was  chiefly  used  for 
yeing  cotton.  The  introduction  of  the  so- 
called  substantive  an>*  colours,  derived  from 
benzidine  and  its  congeners,  has  much  diminished 
the  use  of  safranine. 

8.  Girofle.  A  dimethylphenojcylosafranine 
has  been  produced  by  heating  nrtrosodimethyl- 
anfline  hydrochloride  with  xylidine,  and  sold 
under  the  above  name  as  a  violet  colouring 
matter  of  a  pleasing  shade. 

4.  Safranlsol  C|,H„(OGH,).N«-a  is  a  sub- 
stance which  has  been  obtained  by  Nietzki  by 
the  joint  oxidation  of  one  molecule  of  para- 
phenvlenediamine  with  two  molecules  of  ortho- 
anisidine.  It  dves  a  very  beautiful  yellowish- 
pfaik  with  a  yeUow  fluorescence.  This  pitxluct 
has  been  patented  (Kalle  &  Co.,  D.  R.  P.  24229  ; 
Eng.  Pats.  218, 1883  and  3096,  1883),  but  owing 
to  the  high  price  of  its  production  it  has  been 
unable  to  compete  with  the  eosin  colours, 
which  are  perhaps  still  more  brilliant  in  shade. 

6.  Blagdala  red  CsoHtiN^O.  This  old  and 
very  beautiful  colouring  matter  is  the  safranine 
of  the  naphthalene  series.  It  was  discovered  by 
Schiendl  and  first  investigated  by  Hofmann 
(Ber.  2,  374),  ^o,  however,  owing  to  the  great 
difficulties  of  its  analysis,  assigned  to  it  the 
erroneous  formula  GsoH||N,*HCl.  After  a 
revision  of  the  analjrtical  data  by  Julius  (Ber. 
19,  1385),  its  true  composition  was  established. 
This  substance  cannot  be  prepared  by  the 
usual  oxidation  process  from  paranaphthylene- 
diamine  and*  naphthylamine  because  para- 
naphthylenediamine  is  at  once  transformed  into 
a-naphthaquinone  even  by  the  feeblest  oxidising 
agents.  Magdala  red  has  therefore  to  be  pre- 
pared by  the  old  process  of  heating  a-ammo- 
asonaphthalene  with  a-naphthylamine  acetate. 
The  cnief  product  of  this  reaction  is  rhodindine, 
the  induline  of  the  naphthalene  series  (v.  Indu- 
LiNBS) ;  but  a  small  proportion  (&-8  p.c.)  of 
Magdala  red  is  formed  at  the  same  time.  This 
is  extracted  from  the  melt  by  repeated  treat- 
ment with  boiling  water,  in  wmch  it  is  sparingly 
soluble.  On  cooling*  this  solution  deposits 
the  dyestuff  in  the  uiape  of  gelatinous  flaicea. 
It  is  purified  by  repeated  crystallisations  from 
water.  When  pure,  it  forms  a  dark  crystal- 
line powder,  which  dissolves  in  alcohol  \\ith  a 
pink  colour  and  a  magnificent  oranse  fluoies- 
oence.  It  is  used  for  dyeing  light  pim»  on  silk, 
but  is  now  rapidly  being  replaced  by  rhodamine 


V.  TAIPHBNYLHSTHiKB  COLOTTBINa  MATTKtS)    If 

ready-formed  paranaphthylenediamino  be  added 
to  the  magenta-melt,  the  proportion  of  Ma^gHaj^ 
red  formed  is  considerably  mcreased  (Otto  N. 
Witt,  D.  R.  P.  40868).  It  is  thus  shown  that 
Magdala  red  is,  after  all,  onlv  a  product  of  the 
joint  oxidation  of  paranaphtnylenediamine  and 
a-naphthylamine. 

The  pure  salts  of  Magdala  red,  when  re- 
crystallised  from  spirit,  form  green  needles  with 
a  metallic  lustre.  The  chloride,  sulphate,  pi- 
orate,  and  platinum  double  chloride  have  been 
prepared  and  analvsed.  These  salts  dissolve  in 
concentrated  sulphuric  acid  with  a  blue-black 
colour  which  changes  into  red  on  dilution. 

Mixed  Magdala  reds  have  been  prepared 
either  by  heating  amino-azonaphthalene  with 
aromatic  monoanunee  of  the  benzene  series  (M. 
T.  Leoco,  Ber.  7, 1290),  or  by  heating  aminoazo- 
compounds  of  the  benzene  series  with  para- 
naphthylenediamine  hydrochloride  and  aniline, 
toluidine,  or  even  phenol  (Otto  N.  Witt,  D.  R.  P. 
40868).  These  dyeetufb  resemble  Magdala  red 
in  their  properties. 

6.  Indudne  is  the  commercial  name  of  a 
safranine  dye,  which  is  obtained  by  heating 
the  symmetrical  diphenylmetaphenylenediamine 
(prepared  by  heating  resorcin  with  aniline 
hydrochloride  in  the  presence  of  zinc  chloride) 
with  nitrosodimethylaniline  hvdrochloride.  Its 
constitution  may  be  inferred  from  its  analocr 
to  the  violet  dyestuff  prepared  from  nitroeooS- 
methyUniline  and  phenyl-iS-naphthylamine.  It 
is  a  serviceable  Uue,  of  considerable  intensity, 
but  little  brillian<rv  of  shade. 

Mauveme  Qti^n^fi^  T^^  subunce,  the 
oldest  of  all  the  artificial  colouring  matters,  is 
still  manuf  aotured  in  a  small  way,  and  sold  under 
the  name  of  rosoiane.  it  was  discovered  and 
examined  hj  W.  H.  Perkin  (Roy.  Soo.  Pioe.  35, 
717 ;  Eng.  Pat.  1984,  1856),  who  also  desoribed 
the  mode  of  its  production.  It  is  prepared  by 
oxidising  heavy  aniline  with  potassium  dichro- 
mate,  and  extracting  the  manvehie  formed  with 
water  or  spirit  from  the  black  insoluble  maas 
which  is  the  chief  product  of  the  reaction.  A 
dyestuff  resembling  mauvelne  in  all  its  properties 
may  be  prepared  by  the  reaction  of  nitroeo- 
dipnenylamine  on  aniline  (Otto  Fischer  and 
Hepp,  Ber.  21,  2617)  or  by  the  joint  oxidation 
of  diphenylmetaphenylenediamine  and  para- 
phenylenediainine  or  meta-aminodiphenylamine 
and  para-aminodiphenylamine.  These  syntheses 
are  a  clue  to  the  constitution  of  mauvelne, 
which  has  been  a  mystery  for  nearly  half  a 
century — it  stands  revealed  as  phenylphenosa- 
franine.  The  above  sjmthetical  methods,  have 
been  adopted  for  the  industrial  preparation  of 
mauvelne,  as  they  give  better  yields  than 
Perkifi's  old  process  of  oxidation.  Mauvelne 
is  generally  sold  in  the  shape  of  a  violet  paste. 
It  is  insoluble  in  cold,  sparingly  soluble  in  hot 
water,  easily  soluble  with  a  fine  purple  shade  in 
spirit.  Concentrated  sulphuric  acid  dissolves 
it  with  an  olive-green  colouration,  which  on 
dilution  with  water  changes  through  green  and 
blue  into  purple.  Mauveine  still  holds  its  own 
against  the  cheaper  new  violets  on  account  of 
its  great  fastness  to  light  and  other  influences. 
It  is  used  for  shading  the  white  in  bleached  silks, 
and  also  for  printing  on  paper.  (It  was  also  used 
for  printing  the  old  violet  penny  postage  stamp.) 


AZINEa 


449 


Manyelne  yields  on  oxidation  a  pink  dyestnff 
which  18  Ba|ypo8ed  to  be  identical  with  ordinary 
phenosafranine.  In  our  opinion  this  statement 
requires  confirmation.  O.  N   W. 

Addendum. 

Since  the  foregoing  article  was  revised  by 
the  late  Prof.  Witt  &ere  has  been  rolativelv 
slight  activity  in  the  azine  group  of  dyes,  such 
developments  as  have  taken  place  being  chiefly 
theoretical ;  on  the  technical  side  arow  new 
or  improved  methods  of  preparing  aadne  deriva- 
tives have  been  patented,  and  are  noted  later, 
but  substantially  the  situation  remains  much  as 
it  was,  no  striking  advances  having  been  made. 

So  far  as  concerns  the  theory  of  the  structure 
of  the  dyes  of  this  class,  we  may  note  that  the 
general  consensus  of  opinion  amongst  chemists 
is  that  the  ortho-quinoid  formulation  is,  on  the 
whole^  in  better  agreement  with  the  known  facts 
than  the  older  para-quinoid  strictures  ascribed 
to  them  by  Witt,  and,  in  addition,  sa&anine,  one 
of  the  most  important  members  of  the  azine  series, 
is  usually  given  a  symmetricalformula  rather  than 
the  unsymmetrical  formula  favoured  by  Witt. 

We  may  therefore  note  shortly  the  chief 
grounds  upon  which  these  alterations  are  based  : 
Hrst  as  regards  the  symmetrical  formulation, 
Nietdd  showed  that  the  same  phenyl-safranine 
was  obtained  by  condensing  (a)  phenyl-m- 
phenylenediamine  and  phenyl-j>-phenvlenedi- 
amine;  {b)  diphenyl-m-phenylenediamme  and 
jD'phenylenediamine,  according  to  the  schemes : 


H.N-y-; 


(«) 


I 


H^- 


NHC,Hj 


0* 

CEsa 

C.H,  CI 


NH, 


A  result  that  appears  hardly  explicable  if  we 
assume  a  aymmetrical  formula  for  the  safranine. 
Further,  the  synthesis  of  safranine  from 
m-aminodiphenylamine  and  p-phenylenediamine 
also  points  in  tne  same  direction,  since  a  safnt- 
nine  is  also  produced  if  methyl-m-phenylene- 
diamine  be  used  in  place  of  phenyl-m-phenylene- 
diamine,  a  result  clearly  incompatil^Ie  with  an 
unsymmetrical  formula,  for  whilst  the  methyl 
group  can  replace  the  phenyl  group  attached 
to  the  azonium  nitrogen  on  the  symmetrical 
formula,  it  cannot  possibly  replace  one  of  the 
benzene  nuclei  of  the  azine  ring  system  as  would 
be  demanded  by  the  unsymmetrical  formula. 

Nietzki  clamied  to  have  shown  the  existence 
of  two  isomeric  diethyl  safranines  which  he 
prepared  from  diethylphenylenediamine+2  mols. 
anitine,  and  from  anifine,  -f  p-phenylenediamine 
-4-diethy1aniline  respectively,  and  quoted  this 
Vol.  I—r. 


as  an  argument  in  favour  of  the  unsymmetrical 
formula.  Komer  and  Sohraube,  however  (C3iem. 
Zeit.  17,  305),  destroyed  this  argument  bv 
showing  that  the  two  isomers  were  identical. 
A  further  argument  in  favour  of  the  un^rm- 
metrical  formula  was  brought  forward  by 
Barbier  and  Sisley  (Ann.  Chim.  Phys.  1908,  96)» 
who  claimed  to  have  proved  the  existence  of 
two  isomeric  safranines,  an  unaymmetrical  and 
a  symmetrical,  the  technical  dye  consisting  of  a 
mixture  of  both  forms.  Hewitt,  Newman,  and 
Winmill  have,  however,  contradicted  this  state- 
ment (Chem.  Soc.  Trans.  1009,  95,  577).  Havas 
and  Bemhard  (Ber.  46,  272.3)  also  claim  to  have 
proved  that  phenosafranine  is  homogeneous, 
and  that  Barbier  and  Sisley^s  two  products  are 
either  different  hydrates  or  homologues  which  may 
be  present  in  the  purest  commercial  safranine. 

The  balance  of  evidence  api>ear8,  therefore, 
to  be  strongly  in  favour  of  tne  symmetrical 
formula  for  the  safranines  : 

(fX) 

h^/^W^\nh. 

C.H, 

As  regards  the  vexed  question  of  ortJuh 
versus  para-  quinoid  structure,  we  cannot  say 
that  this  is  finally  settled,  as  there  is  little  doubt 
that,  in  certain  cases,  at  all  events,  tautomerism 
occurs  between  the  two  forms. 

Assuming  the  correctness  of  the  mnmetrical 
arrangement  discussed  above,  we  nave  three 
possible  methods  oi  writing  the  structural 
formula : — 


H,N 


aixX: 

0 


I. 


^N/^^NHHa 


a/ 1 

0 


III. 

(For  a  fourth  suggested  formula,  c/.  Balls, 
Hewitt,  and  WinmillTChem.  Soc.  Trans.  1912, 
101,  1840.) 

2  O 


4B0 


AZINEa 


Of  these,  fonnoU  I.,  originally  proposed  by 
Bemthsen  (Ber.  19,  2690),  is  constmoted  in 
accordance  with  the  older  'peroxide*  formula 
for  quinone,  which  is  not  used  now,  and  may 
therefore  be  disregarded. 

Between  II.  and  III.,  the  ;»ra-qninoid  and 
the  oriJIo-qainoid  formnln,  a  decision  could  be 
arriyed  at  by  the  behayiour  of  the  substance 
with  nitrous  acid,  since  II.  contains  only  one 
amino-  group,  whilst  III.  possesses  two.  One 
amino-  ^up  can  be  readily  removed  by  diazo- 
Usation  in  the  ordinary  way,  yielding  aposafra- 
nine,  whilst  the  second  group  Is  considerably 
more  resistant ;  but  Kehrmann  (Ber.  1896,  29, 
2316),  by  diazotising  the  sulphuric  acid  solution 
of  aposafranine,  succeeded  in  removing  the 
second  amino-  group,  obtaining  by  this  means 
phenyl  phenazonium  chloride : 


oco 


> 


a/  1 


0 


which  can  only  have  an  orf  Ao-quinoid  structure 
(c/.  also  Nietzki,  Ber.  29,  2771). 

A  further  proof  by  Kehrmann  (Ber.  30, 
1566,  2620 ;  33,  395)  consists  in  the  fact  that 
on  treating  phenylphenazonium  chloride  with 
ammonia  an  amino-  ffroup  is  added  on  (just  as 
quinone,  for  example,  adds  on  hydrochloric 
acid)  yielding  leucoaposafranine : 


+NH, 


NH, 


a/  I 

.  ..-     0 

which  oxidises  at  once  in  air  to  aposafranine 
itself;  if  the  latter  be  then  acetylated  and 
again  treated  with  ammonia  a  further  amino- 
group  is  added  on  yielding  acetylphenosafranine : 

(    J  +0+NH, 

'\m/\/\nhcoch,        • 


0 


l\)l 

0 


OX) 

6 


\ 


NH-COOH, 


Such  a  synthesis  is  readily  explicable  on  the 
orfAo-quinoid  hypothesis,  but  it  would  be  difficult 
to  understand  how  ammonia  could  add  on  to 
the  non-quinoid  nucleus  were  the  para-quinoid 
structure  aocepted. 

We  may  therefore  take  it  that  the  behaviour 
of  the  azine  group  of  dyes  can  be  best  explained 
by  the  assumption  of  an  orf  Ao-quinoid  stnicture, 
but  the  possibility  of  tautomeric  change  into 
the  t>-quinoid  form  must  not  be  lost  sight  of. 

Kehrmann,  Havas,  and  Grandmougin,  and 
their  pupils,  have  earned  out  a  good  dcial  of 
research  in  recent  years  on  the  structure  of  the 
azine  dyes.  In  jpartioular,  they  have  examined 
the  behaviour  ot  some  phenazonium  compounds 
with  vaiying  concentrations  of  sulphunc  acid« 
As  is  well  known,  by  increasing  tiie  concentra- 
tion of  the  acid  strilong  colour  changes  are  pro- 
duced, and  the  results  obtained  show'  that, 
with  few  exceptions,  the  number  of  colour 
clumges  produM  increases  with  the  number  of 
amino-  groups  present  in  the  molecule,  which 
they  explain  by  assuming  that  salt  formation 
takes  place  step-wise,  each  transformation  of  a 
basic  into  a  salt  group  causing  a  colour  change. 

Frequently  the  second  ult  of  a  diamino 
compound  exhibits  colour  and  spectral  relation- 
ships identical  with  those  shown  by  the  salt  of 
t^e  monoamino  compound,  the  effect  of  the 
acid  being  to  neutralise  the  chromophoric  effects 
of  the  particular  amino-  group,  e,g.  the  '  second  * 
colouration  of  1:3,  3:7,  or  3:11  diunino- 
phenylphenazonium  salts  is  the  same  as  that  of 
the  3-amino-  compound  '  first '  eoloorataon  (Ber. 
46,  2802). 

Where  Ui^ule  does  not  hold  good  the 
assumption  IBnule  that  a  change  has  ocoorred 
from  ortho-  to  pam -quinoid  structure,  or  vice 
versa. 

Most  of  the  researches  of  these  investigators 
are  of  too  theoretical  a  nature  to  be  considered 
in  the  present  article,  but  it  is  worthy  of  note 
that  they  brins  forward  evidence  which  tends 
to  show  that  the  assumption  of  such  a  change 
in  the  structure  of  azine  dyes  from  ortho-  to 
para-quinoid  rests  to  some  extent  on  an  experi- 
mentai  basis.  Thus  Qrandmougin  and  Smirous 
(Ber.  46,  3425)  consider  that  the  green  tii-add 
safranine  salts  obtained  on  solution  in  sulphuric 
acid  are  mixtures  of  a  yellow  o-quinoid,  and  a 
blue  p-quinoid  compound,  and  it  was  found 
that  on  treating  such '  green  solutions  with 
sodium  nitrite  they  at  first  undergo  only  partial 
diazotisation,  but  on  standix^  for  some  days  the 
para-  form  is  slowly  rearranged  into  the  ortho- 
quinoid  form,  and  is  bis-diazotised  so  that  on 
pourinff  into  alcohol  phenylphenazine  is  formed. 

Bails,  Hewitt,  and  Newman  (Chem.  Soc 
Trans.  1912,  101,  1840),  from  an  examination  of 
the  absorption  curves  of  various  azine  dyes, 
consider  tnlse  to  confirm  the  tautomeric  struc- 
ture of  the  safranines,  the  structure  changing 
from  orUuh  to  para-quinoid,  according  to  con- 
ditions : 


./^\. 


HQHN 


000 


NH. 


AZOBENZENB. 


481 


h.nA/\n/\/\nh. 

C.H. 


otOto 


C.H. 

ortho 

pttpa 


NH-HQ 


Regarding  other  recent  developments  we 
may  note  tnat  phenazine  has  heen  produced 
by  ZerevitinoY  and  OsstromniiwIftnBki  (Ber.  44, 
2402)  by  heating  nitrobenzene  with  barium  oxide 
at  200''-280*'  C,  the  only  other  substance  pro- 
duced being  aniline. 

Another  synthesis  from  o-nitraniline  and  o- 
nitrobrombenzene,  using  cuprous  chloride  as  a 
catalyst,  is  described  oy  Eckert  and  Steiner 
(Monateh.  1914,  35,  1163). 

On  the  purely  technical  side  we  may  note 
that  Bayer  A^  Ck>.  (D.  R.  P.  230456)  describee 
the  production  of  green  azine  dyes  of  the 
type: 


0  0 


from  1 : 3-diaiylna^thylene  diamines  or  their 
sulphonic  acids.  JBy  oxidising  alkylbenzyl- 
anuine  sulphonic  acids  with  derivatiyes  of 
d^enylamme  sulphonic  acids  of  the  general 
formula : 

(H,N)(SO,H) :  CJEI,NHC,H«X 
(X  3=  hydrogen  or  aralkyl) 

to  the  corresponding  indamine,  and  then  the 
latter  with  an  aromatic  amine,  safranine  sul- 

fhonic  acids  are  produced  (Akt.  ges.  f.  Anililfe 
'ab. ;  Fr.  Pat.  417669). 
In  Fr.  Pat.  426790  (D.  R.^  P.  243491)  the 
Farbwerke  Hochst  claim  the  production  of  a 
safranine  disulphonic  acid  by  the  joint  oxida« 
tion  of  o-iminodiphenylamine  sulphonic  acids, 
sulphanilio  acid,  and  monosulphonic  acids  of 
tertiary  amines  in  which  the  pans-  position  is 
free,  such  as  alkyl-benzyl-aniline  sulphonic 
adds. 

J.  D.  Riedel  claims  the  manufacture  of 
azine  dyes  by  the  action  of  m-toluy1ene  diamine 
and  a-naphthylamine  upon  j:>-nitroso  phenyl- 
glycine  (Eng.  Pat.  22694,  1913;  D.  R.  P. 
268208). 


Basic  safranine  dyes  result  from  the  con- 
densation of  nitrosomethyl-o-toluidine  and  m- 
aminomethyl-p-toluidine,    giving   yellowish-red 

Srints  on  cotton.  A  bettw  method  is  to  pro- 
uce  these  safranine  dyes  by  oxidismg  a  mixture 
of  methyl-p-toluylenediamine  and  methyl-m- 
toluylenediamine  (Durand,  Huguenin  ft  Co., 
Eng.  Pat.  2933,  1915;  D.  R.  P.  282346, 
287271). 

Bayer  ft  Co.  claim  the  production  of  com- 
pounds of  basic  dyes  of  the  safranine  series  by 
converting  the  dyes  or  their  salts  into  the  corre- 
sponding gallocarboxylic  acid  salts  (D.  R.  P. 
285500). 

A  somewhat  fresh  application  of  safranines 
is  given  by  the  Saccharin  Fabrik  vorm.  Fahlberg 
list  ft  Co.,  who  claim  the  treatment  of  pheno- 
safranine  and  its  homologues  with  mercury 
salts,  the  resultant  merourised  safranines 
Dossessing  therapeutic  properties  (D.  R.  P. 
286097). 

Another  therapeutic  use  for  safranine  deriva- 
tives is  describea  by  the  Akt.  Qes.  f.  Aniline 
Fab.  (Fr.  Pat.  463357),  who  daim  the  prepara- 
tion of  a  substance  W  combining  tolusafranine 
with  tannin  in  hot  8  p.o.  soda  lye,  and  pre- 
cipitating the  product  with  salt ;  it  forms  a  red 
powder  dightly  soluble  in  water,  soluble  in  con- 
centrated sulphuric  add  to  a  green  solution. 
It  has  no  puigative  action,  and  may  be  used  as 
a  drug  for  the  treatment  of  trypanosoma  and 
other  protozoic  infections. 

Finally,  it  should  be  noted  that  recent  work 
by  Qreen  and  others  (Ber.  44,  2570 ;  45,  1955  ; 
46,  33  ;  Proc.  Chem.  Soc.  28,  250,  1912 ;  Chem. 
Soa  Trans.  97,  2388)  has  proved  that  aniline 
black  is  a  complex  azine  denvative  {see  Ariunb 
blaok).  The  mdulines  and  nigrosines  are  also 
complex  derivatives  containing  azine  nudd 
{see  INDUUNSS  and  Niobosines). 

Fa    A.    Ma 

AZOBBNZENE  Ci,H,  ^Na.  A  product  of  the 
partial  reduction  of  nitrobenzene,  obtsined  by 
Mitscherlich  (Annalen,  12,  311)  by  boiling  an 
alcoholic  solution  of  nitrobenzene  with  potash 
and  distillinjB;  the  product. 

PreparcUton. — Azobenzene  is  obtained  by 
acting  i»ith  sodium  amalgam  (4rn5  p.c  of 
sodium)  on  nitrobenzene  dissolved  in  ether  con- 
taining water  (Werigo,  Annalen,  135, 176 ;  Alexe- 
jeff,  J.  1864,  525 ;  Rasmack,  Ber.  5,  367) ;  the 
product,  according  to  Alezejeff  (J.  1867,  503)  is 
azobenzene  or  azoxybenzene,  according  as  the 
sodium  amalgam  or  nitrobenzene  is  in  excess. 
Chi  the  largo  scale  azobenzene  is  prepared  by  the 
reduction  of  nitrobenzene  in  alcoholic  solution 
with  zinc-dust  and  aqueous  soda.  In  this  re- 
action Uie  reduction  tends  to  go  further,  and 
some  hydrazobenzene  is  also  obtained ;  this, 
however,  is  readily  oxidised  to  azobenzene  if 
nitrous  fumes  are  passed  into  the  alcoholic  solu- 
tion of  the  product  fAlexejeff,  J.  1867,  503). 
Azobenzene  can  also  be  prepared  by  distilling 
azoxybenzene  (1  part)  with  iron  filings  (3  parts) 
(Schmidt  and  Schultz,  Ber.  12, 484) ;  by  heatmg 
nitrobenzene  on  a  wator-bath  with  the  calculated 
quantity  (2  mols.)  of  stannous  chloride  dissolved 
in  excess  of  aqueotis  oaustio  soda  (Witt,  Ber. 
18,  2912) ;  by  reducing  nitrobenzene  in  alcoholic 
solution  with  magnesium  amalgam  (yidd  95  p.c.) 
(Evans  and  Fetsch,  J.  Amor.  Chem.  Soo.  1904, 
11158);   by  reducing  nitrobenzene   with  alkali 


4ff2 


AZOBENZENE. 


sulphide  in  the  preeence  of  alkali  (Farb.  yoim. 
Meuter,  Luchu,  and  Brfining,  D.  R.  P.  21624«t, 
J.  Soa  Chem.  Ind,  1909,  1310) ;  by  heating 
nitiobeniCTie  with  cbarco«d  and  alkali  (Farbu 
vorm.  Fried.  Bayer  A;  Co.,  D.  R.  P.  210S06; 
Chem.  Zentr.  1909,  2,  163);  bv  treating  phenyl- 
hydraxine  with  bleaohilig  powaor  solution  (Brun- 
ner  and  Pelet,  Ber.  1897,  284).  Axobenzene 
can  be  prepared  by  the  dectroljrtio  redaotion 
of  nitrobenzene  in  the  preeenoe  of  alkali  (Elbe 
and  Kopp,  J.  Soc.  Chem.  Ind.  1898,  1137  ;  Lob, 
Ber.  1900,  2329 ;  Farb.  vorm.  Fried.  Bayer  & 
Ca,  D.  R.  PP.  121899  and  121900;  Chem. 
Zentr.  1901,  2,  163;  Farb.  vorm.  Meister, 
Luciua  and  Brfinmg;  D.  R.  P.  141635;  Chem. 
Zentr.  1903,  (L)  1283 ;  and  Farb.  Torm.  Weiler- 
ter.Meer,D.  R.  P.  138496;  Chem.  Zentr.  1903, 

(i.)  372). 

Properties.  ^Asobeaxime  orystallises  in  large 
yellowish-red  orystals  belonging  to  the  mono- 
clinic  system  (Boeris,  R.  AcoAd.  Linoei,  [6]  8,  L 
676),  and  to  the  rhombic  system  ( Alexejeff,  Chem. 
Soc  Abetr.  42,  966) ;  melts  at  68^  boils  at  293^ 
and  is  readily  soluble  in  alcohol  and  ether,  in- 
soluble in  water.  From  benzene  it  ci^^stallises 
with  benzene  of  crystallisation  in  rhombic  prisms^ 
which  lose  benzene  on  exposure  to  the  air. 
Weak  reducing  agents,  such  as  ammonium  sul- 
phide or  zinc-dust  in  alkaline  solution  (Alexeieff, 
Annalen,  207, 327)  or  phenylhydrazine  (Walther, 
J.  pr.  Chem.  1896,  64,  433),  convert  azobenzene 
into  hydrazobenzene,  but  benzidine  is  obtained 
when  stronger  reducing  agents  such  as  sul- 
phurous acid  or  hydrogen  iodide  are  employed 
(Bordenstein,  D.  R.  P.  172669;  J.  Soc.  Chem. 
Ind.  1907,  272),  or  the  alcoholic  solution  is 
treated  in  the  cold  with  stannous  chloride  and 
a  little  sulphuric  acid  (Schultz,  Ber.  17,  464 ; 
Mentha  and  Heumann,  Ber.  19,  2970).  Azo- 
besizene  can  also  be  electrolytioally  reduced  to 
benzidine  (Lob,  Ber.  1900,  2329 ;  when  heated 
with  ammonium  hydrogen  sulphite  and  alcohol 
under  pressure,  it  is  converted  into  benzidine- 
sulphamic  acid  (Spiegel,  Ber.  18,  1481).  When 
melted  with  p-phenylenediamine  in  the 
presence  of  ammonium  chloride,  it  yields  a 
soluble  induline  dye  (Farb.  vorm.  FriecL  Bayer 
&  Co.,  D.  R.  P.  63198 ;  Ber.  1891,  Ref.  137).  Azo- 
benzene yields  a  mixture  of  mono-,  di-,  and  tri- 
nitroazot)enzene0  when  treated  with  fuming 
nitric  acid  (C^rhardt  and  Laurent,  Annalen,  76, 
73;  Janovsky  and  Erb,  Ber.  18,  1133;  19, 
2167;  Janovsky,  Monatsh.  7,  124  ;  Werner  and 
Stiasny,  Ber.  1899,  3266):  ordinary  sulphuric 
acid  dissolves  it  without  alteration,  whilst 
the  fuming  acid  at  130*  converts  it  into 
azobenzenemonosulphonic  acid  (Griess,  Annalen, 
164,  208;  Janovsky,  Monateh.  2,  219); 
chromic  acid  oxidises  it  to  carbon  dioxide 
and  nitrogen  (De  Coninck,  0>mpt.  rend.  1899, 
128,  682).  The  bromine  derivatives  of  azo- 
benzene have  been  examined  by  Weriso  (Anna- 
len, 166,  189),  Janovsky  (2x.),  and  Mills  {Chem. 
Soc.  Trans.  1894,  61). 

AZOBENZENE   RED    v.  Azo-   coloubino 

1IATTXB8. 

AZO-BLACK  or  NAPHTHOL  BLACK  v.  Azo- 

CWLOXnUNO  MATTBB8. 

AZO-BLUE  V.  Azo-  colouring  matters. 
AZO-OOOCINE  V.  Azo-  coix)t;riiyo  matters. 
AZO-  COLOURING  MATTERS. 
History. — ^The    colouring    matters    of    thie 


olaas  contain  one  or  more  azo-groups — N  :  N — 
linking  toceUier  aromatic  radicals.  The  tjrpical 
parent  suBstance  &om  which  these  compounds 
may  be  rMarded  as  being  derived  is  azobenzene. 
(3,1T,-N :  W-C,H.,  which  nas  been  known  since 
the  year  1834  (Mitscherlich,  Annalen,  12,  311). 
The  basic  and  acid  derivatives  of  azobenzene 
are  all  colouring  matters,  the  amino-  derivative, 
aminoazobenzene,  having  been  the  fibrst  of 
these  compounds  which  was  prepared  and  intro- 
duced into  commerce  on  anythmg  approachinff 
a  large  scale  by  the  firm  of  Simpson,  Maule,  and 
Nicholson  in  1863.  This  substance  was  jpte- 
pared  by  the  action  of  nitrous  gases  on  aniline 
aiasolved  in  alcohol,  and  was  known  in  the 
market  by  the  name  of  <  aniline  yellow,*  the 
true  constitution  of  the  colour  beinc  at  the  time 
unknown.  The  introduction  of  tne  first  azo- 
colour  into  commerce  is  thus  due  to  the  firm 
above  mentioned,  although  the  production  of 
the  colour  iteelf  appears  to  have  been  previously 
obeervecl  by  Mine  (Compt.  rend.  1861,  62,  31 1|, 
Luthringer  (Fr.  Pat  60901,  Aug.  30,  1861), 
and  Griees  (Annalen,  1862,  121,  262,  noU). 
The  first  researches  on  the  diazo-  compounds 
(as  distinguished  from  azo-  compounds)  were 
published  m  1868  by  Grioss  (Annalen,  106,  123), 
who  in  1862  discovered  a  compound  produced 
by  the  action  of  nitrous  acid  on  aniline,  to  which 
he  gave  the  name  of  *  diazoamidobenzol ' 
(Annalen,  131,  267).  The  latter  was,  however, 
a  true  diazo-  compound,  and  on  comparing  it 
with  the  *  aniline  yellow '  of  commerce  it  was 
found  that  the  two  substances  were  isomeric, 
a  discovery  which  led  to  the  establishment  of  the 
true  formula  of  aminoazobenzene  by  Uartius 
and  Griees  in  1866  (Zeitsch.  Chem.  N.  F.  2, 132). 
In  this  same  year  a  brown  dye  was  sent  into  the 
market  by  the  firm  of  Roberts,  Bale,  and  Ca, 
of  Manchester,  and  this  colouring  matter  (known 
as  lAanchester  Brown,  Vesuvine,  Phenylene 
Brown,  or,  more  ffenerally,  Bismarck  Brown) 
wao  investigated  oy  Caro  and  Griess,  and 
identified  as  an  azo-  compound  in  1867  (Zeitsch. 
Chem.  N.  F.  3,  278).  These  chemists  reffarded 
it  as  triaminoazobenzene,  but  G.  &>hultK 
(Chemie  des  Steinkohlentheers,  2nd  ed.  2,  103) 
showed  that  it  is  benzene- 1 : 3-di8azophenyl- 
enediamine.  This  compound  still  occupies  ao 
impcnrtant  place  in  the  tinctorial  industries, 
whilst  the  earlier  known  aminoazobenzene 
(aniline  yellow)  has  been  completely  abandoned 
on  account  of  its  fugitive  chaiacter.  It  is,  how- 
ever, used  in  the  preparation  of  other  azo- 
colouring  matters  and  indulines.  In  1876  a 
beautifully  crystalline  orange  colouring  matter 
n^jkde  its  appearance  as  a  commercial  product 
under  the  name  of  *  chrysoldine,*  its  composi- 
tion and  constitution  having  been  established 
by  Hofmann  (Ber.  1877,  10,  213),  who  showed 
that  it  was  diaminoazobenzeno.  This  colouring 
matter  was  discovered  almost  simultaneously  by 
Caro  and  Witt,  independently,  in  1876,  but  was 
first  introduced  into  commerce  by  the  latter, 
the  manufacture  having  been  carried  out  by 
the  firm  of  Williams,  Aomas,  and  Dower,  of 
Brentford  and  Fulham. 

The  manufacture  of  chrysotdine  was  the 
first  industrial  application  of  Grieas's  discovery 
of  the  diazo-  compounds,  the  colouring  matter  in 
question  being  prepared  hj  the  action  of  a  diaao- 
salt  (diazobonzene  chloride)  on  «i-phenylene- 


AZO-  COLOURING  MATTERS. 


453 


diamine,  and  this  manufacture  waa  soon 
followed  by  the  appearance  of  acid  aso-  com- 
pounds prepared  by  the  action  of  diaxoeulphonio 
acids  on  phenols.  *The  typical  parent  substance 
of  these  acid  azo-  oolouis  may  be  regarded  as 
hydroxyazobenzene,  C,H,*N,-CcH4'0H,  which 
was  first  prepared  by  Griess  in  1864  (Phil.  Trans. 
163,  670).  The  general  method  by  which  the 
azo-  colours  are  now  prepared  is  an  application  of 
the  reaction  between  oiazo-  salts  and  phenols 
in  alkaline  solution,  first  made  known  by  JKekultf 
and  Hidesh  (Ber.  1870, 3, 233),  the  first  colouring 
matters  of  this  class  having  been  introduced  by 
Witt  under  the  name  of  '  Tropsolines  '  (Chem. 
Soo.  Trans.  1870, 35, 179),  and  simultaneously  by 
Poirrier,  of  St.  Denis,  under  the  designation  of 
'  Orange  *  of  various  brands.  Since  the  first 
appearance  of  the  acid  azo-  colours  immense 
numbeiB  of  these  compounds  have  been  sent 
into  commerce  under  various  designations,  the 
first  patent  having  been  taken  out  by  Griess  in 
1877  (K  P.  3608),  and  being  quickly  followed 
by  othfifB,  which  will  be  referrod  to  in  due  order. 
Of  the  aoid  azo-  colours  described  in  the  earlier 
speoifioationB,  the  most  successful  from  an 
industrial  point  of  view  were  those  manufactured 
by  the  Badische  Anilin-  und  Soda-Fabrik  (Ber. 
1870,  12,  1364),  and  bv  Meister,  Lucius,  and 
Bruning,  of  Hochst  (ibia.  144). 

The  next  step  of  importance  in  the  industrial 
history  of  the  azo-  colours  was  the  introduetion 
of  diaazO'  compounds,  containing  two  azo-  groups. 
The  typical  compound  of  this  cutss  is  benzeueazo- 
benzeneazophenol  CgHj-Nj-C.H.-Nj-C-H^-OH, 
discovered  m  1877  by  Caro  and  Schraube  (Ber. 
10,  2230).  In  1870  appeared  the  '  Biebrich 
scarlet'  of  Nietzki  (Ber.  1880,  13,  800,  1838), 
which  was  introduced  by  the  firm  of  Kalle  k 
Co.  of  Biebrich.  This  dyestuff  is  prepared  by 
combining  diazotised  aminoazobenzenodisul- 
phonio  acid  with  /3-naphthoI,  and  was  the  first 
of  the  secondary  disazo-  compounds.  The  first 
primary  disazo-  colouring  matter,  *  Resorcin 
brown,  was  discovered  in  1881  by  WaUach, 
who  combined  tioo  molecules  of  a  oiazo-  com- 
pound (m-xylidine  and  sulphanilic  acid)  with  om 
molecule  of  a  phenol  (resorcinol).  In  1884  a 
very  important  discovery  in  the  history  of  azo- 
colouring  matters  was  made  by  P.  Bottiger,  who 
found  that  the  disazo-  compound  obtained  by 
combining  the  tetrazo-  salt  prepared  from 
benzidine  with  naphthionic  acid  possessed  the 
valuable  property  of  dyeing  cotton  direct,  with- 
out the  use  of  a  mordant.  This  colouring 
matter  was  put  on  the  market  by  the  Aktienge- 
seUschaft  fiir  Anilinfabrikation,  under  the  name 
of  *  Congo  red.'  This  discovery  has  given  rise 
to  the  production  of  a  vei^  laige  number  of 
similarly  constituted  colouring  matters,  which 
appear  on  the  market  under  the  names  of  benzo-, 
dongo-,  diamine-,  and  other  dyestufiEs.  In  the 
following  year  another  important  development 
was  announced  by  the  introduction  of  the  first 
satisfactory  black  azo-  colouring  matter  (naph- 
thol  black)  for  wool.  This  was  discovered  by 
Hoffmann  and  Weinberg,  and  placed  on  the 
market  by  L.  Cassella  £  Co.  In  1887  A.  G. 
Green  found  that  primuline,  which  he  had  dis- 
covered, dyed  cotton  direct,  and  that  the  yellow 
colouring  matter  when  thus  dyed  on  the  fibre, 
oould  be  diazotised  and  combined  (developed) 
with    /B-naphthol,     m-phenylenediamine,     and 


I  similar  '  developers,'  thus  giving  rise  to  »  series 
'  of  new  azo-  dyestnffs  (Ingrain  colours).  This 
discovery  led  to  the  manufacture  ci  many  azo- 
colouring  matters  which  were  capable  of  bemg 
similarly  diazotised  and  developed  on  the  fibre 
{eg,  diamine  black),  as  also  to  the  production  of 
azo-  colouring  matters  oti  the  fibre  by  treating 
the  fibre  already  dyed  with  an  azo-  colour  with 
a  diazo-  compound  {e,g.  benzonitrol  colours). 
In  both  oases  darker  and  faster  dyeings  are 
obtained. 

The  first  direct  cotton  black  (diamine  bladk, 
RO)  was  discovered  in  1889  by  Gans  (CSassella 
&  Co.),  and  in  1801  Hoffmann  and  Daimler 
prepared  the  first  green  colouring  matter  of  this 
kind  (diamine  green). 

A  modified  method  of  the  process  introduced 
in  1880  by  Read  Holliday  and  Sons,  of  producing 
insoluble  azo-  colouring  matters  direcuy  on  the 
fibre,  has  been  largely  developed  ol  late  years. 
The  first  example  of  this,  viz.  the  combination 
of  diazotised  p-nitroaniline  with  iS-naphthcl 
('  paranitraniline  red ')  still  holds  the  place  of 
greatest  importance. 

Manufacture, — ^The  general  method  of  pre- 
paring the  azo-  colours  on  4  large  scale  depends 
upon  the  reaction  between  a  diazo-  salt,  usually 
the  chloride,  and  a  phenol  or  phenolsulphonic 
acid  in  presence  of  an  alkali^  as  typified  oy  the 
following  example : — 

C,H,-N,a+C,H.-ONa 
DlaxobeDzene      Sodium 
chloride.      phenozide. 


.CjH.N.OjH^OH+NaCH. 
Benzeneaxoph  enoi. 


Aminosulphonic   acids    or   aminocarboxylio 
acids  when  diazotised  react  in  a  similar  manner : 

CiH*<sO*,>  +0,H.ONa 
Diasoeulphaullio  Sodium 

acid.  phenozide. 

-SOjNaCH^N.CH.OH. 
Sulphobenzeneasophenol  OioiUum  ialt). 

Preparation  of  the  diazo-  saUe. — The  amine 
to  be  diazotised  is  usually  dissolved  in  about 
10  parts  of  water  and  one  equivalent  of  hydro- 
chloric (more  rarely  sulphuric)  acid.  For 
diamines  twice  this  amount  of  acid  is  taken. 
The  solution  ^  is  now  cooled  by  adding  ice  until 
the  temperature  is,  in  the  case  of  aniline,  the 
toluidinedi,  the  xvli^es,  &c.,  0*-2^  or,  in  the 
case  of  the  naphthylamines,  the  nitroanilines 
and  diamines  such  as  benzidine,  tolidine, 
dianisldine,  &a,  Bf*-1Q^,  This  ib  done  by  adding 
ice  to  the  solution.  More  acid  (ljh-2  equiva- 
lents) is'  now  added  (or  3-4  in  the  case  of 
diamines),  and  a  solution  of  the  calculated 
quantity  of  sodium  nitrite  is  run  in,  sufiScient 
being  used  to  give  a  reaction  with  starch-iodide 
paper  after  the  whole  has  been  mixed  for  two 
or  three  minutes.  (For  velocity  of  diazotisation» 
see  Hantzsch  and  Schumann,  Ber.  .1800,  32, 
1601 ;  Schumann,  t^id,  1000,  33,  527  ;  Tassilly, 
Compt  rend.  1913,  157,  1148 ;  1014,  158,  335, 
480).  In  certain  cases  {e.g.  a-naphthylamine, 
p-nitroaniline,  &c.)  it  is  better  to  add  the 
nitrite  all  at  once  in  order  to  avoid  the  formation 
of  'the  diazoamino-  compound.  In  diazotising 
such  compounds  as  give  an  insoluble  diazo- 

1  Some  of  the  dlazosulphonlc  adds,  such  as  diaso- 
naphthionic  acid,  are  hisoluble  In  water,  and  are  there- 
fore ampioyed  hi  a  itate  of  luspenslon. 


454 


AZO-  OOLOUBINO  MATTBRa 


deanAxvt,  m,  for  example,  p-eolphobeoieneeso- 
o-naphthylamme  or  p-aoetylammobenzeiieeEO- 
a-naphibylamine*  and  which  themeehreB  are 
ineomble  in  acide  (under  the  above  conditione) 
it  ie  adTieable  to  lue  an  ezoeas  of  nitrite  and 
to  stir  the  ioe-oold  mixture  for  eeveral  houn. 
Spedal  methods  have  to  be  employed  to  diaco- 
tue  amines  oontainiog  sereral  negative  groups ; 
the  operation  may  often  be  effected  by  carryinf 
it  ont  in  the  presence  of  excess  of  50  p.c.  sul- 
phtirio  acid,  and  Witt  has  shown  (Bar.  1009, 
42,  2063)  that  diasotisation  is  easily  brought 
about  in  these  cases  by  employing  strong 
nitric  aoid.  Other  substances  which  axe  difficult 
to  dtazotiw  satisfactorily  are  those  which  are 
readily  oxidised  by  the  nitrous  add,  such  as 
the  1:2-  and  the  2 : 1-aminonaphthols  and 
their  snlphonic  acids.  In  this  case  the  diazotisa- 
tion  may  be  done  in  the  presence  of  sino  or 
copper  salts  (compare  £.  P.  10235  of  1904; 
D.  k  P.  171024,  172446 ;  F.  P.  353786)  or  by 
means  of  zinc  nitrite.  Another  method  is  to 
diazotise  in  presence  of  an  excess  of  acetic  or 
oxalic  acid  (compare  D.  R.  P.  155083,  175593, 
also  E.  P.  2946  of  1896). 

Difficulties  are .  often  encountered  in  en- 
deavouring to  diasotise  certain  diamines. 
o-Phenylene-  and  tolvlene-diamines  cannot  be 
diasotised,  as  they  yield  the  azimino-  derivatives, 
and,  under  the  usual  conditions,  the  meta- 
diamines  furnish  Bismarck  brown ;  but  if  the 
diamine  is  run  into  a  mixture  of  nitrite  and  acid 
the  totrazo-  compound  may  be  obtained  (Griess, 
Ber.  1886,  19,  317 ;  Tauber  and  Walder,  Ber. 
1897,  30,  2901 ;  K  P.  1593  of  1888 ;  D.  R.  P. 
103685).  In  the  case  of  p-phenylenediamine 
and  certain  diamines  of  the  naphthalene  series 
diazotiBation  is  brought  about  indirectly,  as  the 
direct  action  of  nitrous  acid  often  leads  to  a 
mixture  of  the  mono-  with  the  bis-diazo-  (or 
totraco-)  compound.  Either  the  correspondmg 
nitroamine  or  the  monoacetylated  diamine 
is  employed.  Tlus  is  diazotised  and  combined 
with  a  component  in  the  usual  way  (see  below), 
and  then  the  nitro-  group  is  reduced  or  the  acetyl 
group  hydrolvsed  when  the  free  amino-  group 
can  then  reamly  be  diazotised.  Some  diamines, 
indeed,  can  omy  be  diazotised  as  regards  one 
amino-  group,  the  other  being  qulto  unattAcked. 
In  such  cases  {eg.  o-nitro-p-phenylenediamine, 
1 :  4-naphthylenediamine-2r8uiphomc  acid — ^the 
latter  being  diazotisable  only  in  acetic  or  oxalic 
acid  solution^  the  monodiazo-salt  is  combined 
with  a  component  and  then  the  remaining 
amino-  group,  which  before  resisted  all  attempts 
at  diazotisation,  is  easily  diazotised  (compare 
BfUow,  Ber.  1896  29,  2285;  E.  P.  2946  of  1896). 
(For  further  information  on  this  subject,  see 
Gain,  The  Ghemistrv  and  Technology  of  the 
Dia7o-  Ck>m pounds,  Arnold,  1920.) 

Combinatum  {coupling)  of  the  diazo-  compound 
with  a  component  {phenol  or  amine)  to  form  an 
azo-  dyestuff.^ — Before  the  diazo-  solution  is  pre- 
pared a  solution  of  a  phenol  or  amine  is  made 
ready  so  that  no  delay  may  occur  before  coupling 
takes  place.  As  a  general  rule,  phenols  are 
combined  in  alkaline  and  amines  in  acid  (acetic) 
solution.     In  the  case  of  phenols  or  naphUiols 

'  For  the  mechanism  of  the  reaction,  aee  Ghanier 
Oass.  chbn.  iUl.  1914,  44,  U.  503  ;  Auwers  and 
MiobaeUs.  Ber.  1914,  47.  1276 ;  Meyer,  Irschick  and 
SohUSsssr,  ibid.  1741 ;  and  Karrer  Ber.  1016, 48, 189a. 


the  substance  is  fint  diasolTed  in  the  calculated 
amount  of  sodium  hydroxide,  the  solution  diluted 
with  water,  and  sodium  carbonate  added  in 
sufficient  quantity  to  ensure  an  alkaline  reaction 
being  obtained  at  the  end  of  the  combination 
(•.e.  a  little  more  than  one  molecule  of  sodium 
carbonate  to  each  molecule  of  hydrochloric 
acid,  so  that  sodium  hydrogen  carbonate  may 
be  formed).  When  nhenofio  sulphonic  acids 
are  the  components,  tney  may  be  dissolved  in 
sodium  carbonate  instead  of  hydroxide.  The 
phenolic  solution,  bavins  been  cooled  to  about 
10%  is  now  ready,  ana  the  diazo-  solution  is 
run  in  gradually  with  constant  stirring.  Com- 
bination takes  place  at  onoe^i  and  when 
all  the  diazo-  solution  has  been  added,  the 
mixture  must  be  tested  to  ensure  an  alkaline 
reaction,  and  the  preseooe  of  a  slight  excess 
of  the  phenol  (about  2-5  p.c  excess  of  the 
theoretical  amount  is  usually  taken).  The 
next  day  the  colouring  matter  is  filtered  through 
filter  presses.  If  it  has  separated  out,  no  further 
treatment  ii  necessary,  but  if  it  is  still  partiy 
or  wholly  in  solution,  it  is  <  salted  out '  (not  or 
cold)  by  adding  common  salt  until  a  qx>t  on 
filter  paper  shows  only  a  faintiy  coloured  rim. 
In  rare  oases  the  precipitetion  is  effected  by 
acidifying.  The  filtration  is  best  effected  by 
the  aid  of  compressed  air  and  the  press  cake 
IB  spread  on  trays  and  dried.  The  dry  lumps 
are  then  ground  in  a  null,  adjusted  to  *  tvpe ' 
or  '  standard '  by  means  of  common  salt^  sooinm 
sulphate,  Ac,  and  the  product  is  then  ready  for 
the  market.  In  cases  where  the  possibility  of 
the  formation  of  a  disazo-  dyestuff  is  present 
(dihydroxy-  oompounds,  a-naphthol,  to.),  the 
coupling  may  advautageously  oe  carried  out  in 
acetic  acid  solution. 

The  procedure  adopted  in  the  case  of  amines 
is  verv  similar  to  the  above.  The  amino  is 
first  dissolved  in  the  appropriate  amount  of 
hydrodiloric  acid,  the  solution  diluted  and 
sufficient  sodium  acetote  added  to  ensure  that 
no  free  mineral  acid  remains  at  the  end  of  the 
combination  (in  rare  cases  oouplmj;  is  e&cted 
in  mineral  acid  or  alkaline  solution).  When 
the  combination  is  complete,  the  dyestuff  is 
filtered  off  either  as  it  is  or  alter  haying  been 
rendered  alkaline. 

Many  disazo- dyestufb  are  prepared  by  com- 
bining two  molecules  of  the  same  or  diffecent 
diazo-  compounds  with  an  aminonaphthol- 
sulphonio  acid.  In  this  case  oombination  is 
ef^ted  first  in  acid  solution  and  then  the 
monoaso-  dyestuff  thus  formed  is  rendered 
alkaline,  and  the  second  molecule  ol 


compound  added. 

Position  assumed  h^  ik$  oMh  group  in  the 
formation  of  azo-  colounng  mattars.'--{a)  Benzene 
series :  When  the  para-  position  with  respect  to 
the  amino-  or  hydroxy-  group  is  occupied  by  ^ 
hydrogen  atom,  and  no  groups  suoh  as  NO,, 
SOaH,  or  NB,()1,  is  in  the  mete-  position,  the 
azo-  group  enters  the  para-  nosition  in  plsoe  of 
the  hydit)gen  atom.  (6)  Naphihaiene  series : 
In  corresponding  compounds  of  the  naphthalene 
series  (a-naphthvlamine,  a-naphthol)  tne  enter- 
ing azo-  group  also  t-akes  up  tne  para-  position, 
but  when,  in  a-naphthol,  a  sulphonic  group  is 
in  the  3-  or  6-position  with  respect  to  the 


paper 


For  the  fomatlon  of  diaioKkxy-  compounda,  sw  a 
by  DUnroth  and  Eartmann,  Ber.  1908,  41,  4018. 


AZO-  COLOURING  BCATTERS. 


405 


hydroxy-  gronp,  or  a  nitro-  or  NBaCl-  group  is 
in  tha  3-  poution  the  azo-  group  enters  the  Z» 
positioiL 

When  the  para-  position  -is  substitnted, 
the  azo- '  group  enters  the  ortho-(2)-  position, 
but  if  the  para-  subetituent  is  a  carbozy- 
group,  this  is  usually  displaced  by  the  aso* 
group. 

When  diazo-  compounds  act  on  /3-naphthyl- 
amine  or  3-naphthoi.  the  azo-  group  enters 
position  1  (m  the  ortho-  position  with' respect 
to  the  amino-  or  hydroxy-  group).  If  the 
1-  position  in  /l-na{>hth<d  is  occupied  by  a  carb- 
oxy-  groups  this  is  dispLaoed  (compare  aJso 
Scharwin  and  Kaljanoff,  Ber.  1908»  41,  2066 
and  artide  on  Dibaso-  and  Tbtbaio-  oolous- 

OrO  MATISBS). 

Differing  capaeity  for  eotnbinaiian.^AB  will 
have  Deen  gathered  from  tha  preceding  para- 
graph, the  azo-  group  nerer  enters  the  meta- 
position  with  respect  to  an  amino-  or  hrdroxy- 
gronp.  Further,  a  component  in  which  the  para- 
position  is  occupied  by  a  substitueni  group  is 
not  so  readily  attacked  (in  the  ortho-  position) 
as  one  that  is  not  substituted  (when  the  azo- 
group  enters  the  para-  position).  Moreover,  the 
capacity  for  combmation  depends  idso  on  the 
kind  of  diazo-  compound  employed,  thus  2- 
naphthol-8-sulphonic  acid  and  2-naphthol- 
6 : 8-disulphomc  acid  in  dilute  solution  do  not 
combine  at  all  wilii  diazotised  xylidme  or 
naphthylamine^  whilst  diazotised  aniline^  amino- 
asobeniene,  aminoazobenzenesulphonic  acid  and 
naphthylaminesulphonic  acids  couple  easily 
with  them.  The  combination  with  diazotised 
zylidine  and  naphthylamine  can,  however,  be 
made  to  take  ptace  in  concentrated  solution. 
The  diazo-  compound  of  p-nitroaniline,  in  most 
cases,  combines  with  extreme  ease.  Finally, 
2-naphthylamino-6 : 8-disulphonic  acid  does 
not  combine  with  uiy  diazo-  compound.  (For 
measurement  of  the  rate  of  formation  of  dye- 
stuffs,  me  Qoldschmidt,  Ber.  1897,  30,  670, 
2076;  1899,  32,  366;  1900,  33,  893;  1902,  36, 
3634;  Veley,  Trans.  COiem.  Soc.  1909,  96, 
1186.) 

Considering  now  the  formation  of  aio- 
dyestufb  from  tetrazotised  diamines,  it  should 
be  noted  that  diamines  of  the  type  of  benzidine 
furnish  tetrazo-  compounds  which  can  either  be 
combined  with  two  molecules  of  one  component 
(phenol  or  amine)  or  with  one  molecule  each  of 
two  components,  and  the  reaction  can  thus  be 
divided  into  two  stages.  This  holds  good  even 
when  one  component  only  is  used ;  thus  tetrazo- 
tised benzidine  combines  almost  at  once  with 
one  molecule  of  naphthionic  acid,  forming  a 
so-called  intermediate  product ;  but  the  second 
molecule  of  naphthionic  acid  combines  with  this 
only  slowly.  Here  also  a  difference  in  combining 
power  is  to  be  noted,  thus  tetrazotiMd  benzidine 
combines  more  readily  than  does  Uie  correspond- 
ing compound  from  tolidine. 

Cfeneral  properties.^!)  Adion  of  alkalis. 
'Hjdroxvtaxh  dyes  containing  a  snlphonic  or 
carboxylio  group  usually  form  differently 
oolonred  salts,  and  consequently  the  addition 
of  sodium  hydroxide  to  their  solutions  produces 
a  modification  in  the  shade  (compare  Hewitt 
and  Mitchell,  Trans.  1907,  91,  1261).  The 
isomeric    colouring    matters    prepared    from 


I  a-  and  iS-naphthol  show  a  characteristic  differ- 
ence in  that  only  those  derived  from  the  former 
are  chansed  by  sodium  hydroxide  (eg.  benso- 
azurine,  &c.). 

(2)  Action  of  cM  dUuie  acids,  Dyestuffs 
containing  amino-  or  substituted  amino-  sroups 
generally  undergo  a  change  when  treated  with 
dilute  acid  (compare  Fox  and  Hewitt,  Trans. 

1908,  93,    333  ;    Hewitt    and    Thomas,  ibid. 

1909,  96,  1292 ;  Hewitt  and  Thole,  ibid.  1909, 
96,  1398 ;  1910,  97,  611).  In  t^  case  of  Congo 
red  and  methyl  orange  this  change  is  so  pro- 
found that  these  colouring  matters  can  be  used 
as  indicators. 

(3)  Action  of  cold  concentrated  sulphuric 
acid.  Nearly  all  azo-  colouring  matters  give 
characteristic  colour  changes  with  this  reagent, 
and  it  is  often  used  as  an  aid  in  the  detection 
of  dyes.  Mixtures  of  dyes,  when  covered  with 
sulphuric  acid,  often  reveal  themselves  by  the 
various  colours  produced  by  the  particles  as 
they  become  dissolved.  There  are  certain  re- 
lationships between  the  colour  of  the  solution 
of  azo-  dyes  in  sulphuric  acid,  and  therefore  of 
their  absorption  spectra  and  their  chemical 
constitution.  Thus  the  dyestuff  from  amino- 
azobenzenesulphonic add  and  iS-naphthol  ^ives 
a  green  colour,  those  from  the  same  (diazotised) 
amine  and  /9-naphtholsulphonic  acids,  a  blue, 
and  those  from  aminoazobenzene  and  its 
homologues  combined  with  /9-naphtholsulphonic 
acids  a  red  violet  (compare  Ber.  1880,  13,  1840 ; 
Vogel,  Sitzungsber.  K.  Akad.  Berlin,  1887,  34, 
716;  Ber.  1889,  22,  634,  2062;  SchAtze, 
Zeitech.  physikal.  Chem.  1892,  9,  2;  Grebe, 
Diss.  Leipug,  1892). 

(4)  Action  of  h<4  hydrochloric  acid.  Certain 
azo-  colouring  matters,  such  as,  for  example, 
aminoazobenzene,  are  decomposed  when  boued 
with  concentrated  hydrochloric  acid ;  reduction 
and  oxidation  take  place  accompanied  by 
chlorination.  In  the  infltance  quoted  phenyf- 
enediamine,  aniline,  and  benzoquinone  or  its 
chloro-  derivatives  are  produced  (WaUaoh  and 
Kdlliker,  Ber.  1884,  17,  396). 

(6)  Aaion  of  ha  sulphuric  add  (Witt,  Ber. 
1887,  20,  671).  Azo-  colouring  matters  which 
are  derived  from  phenyl-  or  tolyl-j9-naphthyl- 
amine  by  the  action  oS  diazo-  compounds  on 
these  bases,  when  boiled  with  moderately 
dilute  sulphuric  acid,  yield  the  bases,  or  their 
sulphonic  acids,  from  which  the  diazo-  compound 
was  prepared,  together  with  naphthazines. 
Thus  the  dyestuff  obtained  by  combining 
diazotised  sulphanilic  acid  wiui  phenyl-/S- 
naphthylamine,  is  decomposed  into  sulpluuiilio 
acid  and  phenonaphthacine : 

SO,H-C,H4N,CioH,NH-C^g  jj 

-S0,H-C,H4NH,+CitH,/  I Nj.H*. 

(6)  Action  of  nitric  acid.  Azo-  colouring 
matters  are  readily  attacked  by  nitric  acid, 
and  the  course  of  the  reaction  depends  lar^g^y 
on  the  conditions  of  temperature  and  concentra- 
tion. By  the  moderate  action  of  nitric  acid, 
the  dyestuff  may  simply  be  nitrated,  thus 
diphenylamine  orange  yields  ouroumeine  and, 
by  further  action,  azo-  acid  yellow,  the  dyestuffs 
in  both  cases,  however,  being  accompanied  by 
some  nitrodiphenylamine  noduced  by  tiie 
fission  of  the  aso-  group.    AIk>  when  navuMl 


456 


AZO-  GUU)aRING  BiArTEJEUS. 


(diazotised  toluidine  combined  with  aalicylic 
aoid)  IS  nitrated,  it  yields  Persian  yellow  (o-nitro- 
tolueneasosalioylio  acid)  (oompare  Ber.  1906,  40, 
4207). 

Methyl  orance  is  docompoBed  even  by  cold 
dilute  nitric  aoia ;  a  methyl  group  is  eliminated 
in  the  process,  and  dinitromonomethylaniline 
is  produwd.  The  presence  of  a  diazo-  compound 
can  also  be  detected  (Fox,  Ber.  1908,  41,  1989). 

Gold  fuming  nitric  aoid  decomposes  many 
azo-  colouring  mattefs  (particularly  those  con- 
taining an  amino-  or  hydroxy-  group  in  the 
para-  positi<m  with  respect  to  the  azo-  group), 
with  the  production  of  the  diazo-  compound 
from  which  the  dye  is  prepared  and  the  nitro- 
derivatiYe  of  the  other  component;  thus, 
orange  n  yields  diazotised  sulphanilic  acid  and 
a  nitro-  derivative  of  /S-naphthol,  whilst  methyl 
orange  gives  op-dinitrodimethylaniline,  tetra- 
nitrodimethylanilino  and  diazoUsed  sulphanilic 
acid  (O.  Schmidt,.  Ber.  1905,  38,  3201). 

Certain  hydioxyazo-  compounds  combine 
with  two  molecules  of  nitric  acid  forming  un- 
stable nitrates  (Charrier  and  Ferreri,  Gazz. 
ohim.  itaL  1913,  43,  u.  148;  1914,  44,  L  120, 
165,  405). 

Finally,  warm  nitric  add  usually  decomposes 
azo-  dyestuffs,  with  the  production  of  nitro- 
phenols  or  bases. 

(7)  Aciion  of  chiorine  and  bromine.  All  azo- 
colouring  matters  are  readily  attacked  by 
chlorine  or  bromine.  Fission  generally  takes 
place  at  the  azo-  group  with  the  production  of 
nalogenated  phenols  (oompare  Schmidt,  J.  pr. 
Ghem.  1912,  (ii.)  85,  235),  but  some  dyestuffs  aie 
converted  into  substitution  products  (compare 
Ber.  1884,  17,  272). 

(8)  Action  of  reducing  agents.  Reducing 
agents,  such  as  zino-dust  and  water,  zinc-dust 
imH  ammonia,  or  sodium  hydroxide,  zino-dust 
and  dilute  acids,  tin  and  hydrochloric  add, 
stannous  chloride,  a  solution  of  sulphur  in 
sodium  sulphide  (Cobenzl,  Chem.  Zeit.  1915,  39, 
869),  or  sodium  hyposulphite  (technically  known 
as  *hydro6ulphite  )  (Grandmougin,  Ber.  1906, 
39,  2494, 3561,  3929 ;  compare  also  J.  pr.  Ghem. 
1907,  (ii.)  76,  124;  Franzen  and  Stieldorf,  J. 
pr.  Chem.  1907,  (ii.)  76,  467;  0.  Fischer, 
f^tzen  and  Eilles,  J.  pr.  Chem.  1909,  (ii.)  79, 
562)  attack  the  azo-  group  and  convert  it  into 
two  amino-  groups ;  Uius : 

NHjCgH^N :  NC.H5+2H, 

=NH,C.H4NH,+OH,NH,. 

The  base  which  was  used  to  provide  the  diazo- 
compound  is  thus  regenerated,  whilst  the 
other  component  ia  converted  into  its  amino- 
derivative. 

By  careful  reduction  with  zinc-dust,  dyestuffs 
obtained  by  the  combination  of  diatoUsed 
aminoazobenzenesulphonio  acid  with  phenols 
yield  the  aminoazosulphonic  acid  without  the 
latter  undergoing  reauction.  Further,  nitro- 
azo-  dyestufifs  can  be  reduced  to  the  correspond- 
ing aminoazo-  dyestufts  with  sodium  sulphide. 
The  reduction  of  azo-  dyestufifs  is  a  useful 
means  of  attacking  the  problem  of  their  con- 
stitution, althou^  the  operation  requires 
considerable  care  (compare  Witt,  Ber.  1886, 
19,  1719;  1888,  21,  3468,  and  especially  the 
references  quoted  in  connection  with  reduction 
by  hydroemphite). 


Azo-  dyestuffs  are  also  readily  reduced  by 
titanous  chloride,  and  a  process  for  their  estima- 
tion bv  titration  with  this  reagent  has  been 
worked  out  by  Knecht  (J.  Soc.  Dyers,  1903, 
19,  169 ;  Ber.  1903,  36,  166,  1549 ;  1907,  40. 
3819).  A  detailed  account  of  the  method  of 
carrying  out  this  and  other  methods  of  reduc- 
tion ^  will  be  found  in  Knecht  and  Hibbert^s 
New  Reduction  Methods  in  Volumetric  Analysis 
(Longmans). 

(9)  Action  of  aodium  bisulphite.  When  boiled 
with  aqueous-alcohoHc  sodium  bisulphite  solu- 
tion, hydroxyazo-  colouring  matters  g^ve 
sulphurous  esters,  the  hydroxyl  group  being 
converted  into  O'SOtNa  (Voroshoov,  J.  Russ. 
Phys.  Ghem.  Soc  1911,  43,  771;  1915,  47, 
1669;  published  in  French  in  Ann.  Ghim. 
1916,  [ix.]  6,  381 ;  1917,  7,  60).  In  aqueous 
solution  fission  takes  place  (Lepetit  and  Levi, 
Gazz.  chim.  itaL  1911,  41,  i  675). 

Identification  of  cuo-  colouring  matters  o» 
the  fibre.  This  is  carried  out  by  observing  the 
action  on  the  dyed  fabric  of  various  reagents, 
for  which  various  tables  have  been  constructed 
(oompare  Cain  and  Thorpe,  The  Sjmthetio 
Dyestufifs,  4th  ed.  1918;  Lunge,  Chemisch- 
technische  UntersuchungensmeUioden,  Eng. 
trans.,  edited  by  Keane,  1911 ;  Green,  The 
Analysis  of  Dyestufifs). 

Direct  formation  of  azo-  cclowrs  in  the  fibre, — 
The  production  of  an  insoluble  azo-  dyestnfif  in 
the  fibre  ii-as  first  achieved  by  T.  and  R.  HoUiday 
(£.  P.  2757  of  1880),  who  imprsgnated  the  fibre 
with  a-  or  iS-naphthol,  passed  it  then  through 
a  diazo-  solution,  ana  finally  developed  the 
colour  by  treatment  with  alkalL  An  improve- 
ment on  this  process  was  introduced  by  the 
Farbwerke  vormals  Meister,  Ludus  «nd 
Briining,  in  1889,  which  consisted  in  *  padding ' 
the  fibre  (generally  cotton)  with  the  sodium  salt 
of  a  phenol  (usually  /B-naphthol),  and  passing 
the  cloth  through  a  diazo-  solution,  the  free 
mineral  acid  of  which  has  been  neutralised  by 
adding  sodium  acetate.  This  process  is  very 
largely  used  at  the  present  day,  and  is  applied 
to  the  greatest  extent  to  the  production  ot  the 
so-called  *  para-red '  (the  azo-  colour  obtained 
by  combining  diazotised  2>-nitroaniline  with 
/S-naphthol).  The  colouring  matters  produced 
in  this  way  will  now  be  described. 

Paranitraiillliie  Red.  The  colourins  matter 
was  first  prepared  in  substance  by  Meldola  (Cliem. 
Soc.  Trans.  1885,  47,  657)  by  combining  diazo- 
tised p-nitroaniline  with  /3-naphthol  in  alkaline 
solution.  As  stated  above,  it  is  now  almost 
entirdy  produced  on  the  fibre.  The  goods  are 
soaked  in  a  bath  containing  sodium  Jl-naphth- 
oxide  and  Turkey-red  oil,  or  uiickening  materials, 
squeezed  out  and  dried  at  65*--80*.  They  are 
then  passed  through  the  diaso-  solution,  washed 
and  soaped.  In  order  to  avoid  preparing  the 
diazo-  solution  in  the  dye-house,  various  pre- 
parations may  be  used.  Thus,  PannltniillliM 
extra  N  paste  is  a  mixture  ol  |>-nitroaniline 
with  the  calculated  amount  of  sodium  nitrite, 
and  needs  only  to  be  stirred  slowly  into  the 
necessary  quantity  of  hydrochloric  or  sulphozio 
add,  ice,  and  water,  to  produce  the  diaio- 
solutioiL    A   similar    product    is    Benionltiol 

1  For  the  estimation  with  sodium  hjrposalphlle, 
tes  Grandmougin  and  Havsa,  Ghem.  SSeit.  1912,  Stt. 
1167, 


AZO-  COLOURING  MATTEKS. 


467 


pasfca.  Oiher  preparations  contain  the  diazo- 
oompound  in  a  suitable  form  for  keeping. 
Thus,  Mttrotamlne  Bed  is  the  sodium  salt  of 
]^nitroan<fdjazobenzene  (which  is  very  stable) 
and  furnishes  the  true  diazo-  solution  when 
mixed  with  dilute  acid.  Axophor  Bed»  AlOgan 
Bed  and  Nltrazol  C,  are  mixtures  of  the  diuo- 
sulphate  with  sodium  sulphate  (whereby  sodium 
hydrogen  sulphate  is  produced) ;  they  are  dis- 
solved in  water,  the  solution  filtered,  if  necessary, 
and  neutralised  before  use  with  sodium  acetate 

or  hydroxide.  Paranll  is  a  stable  compound  of 
diazotised  j9-nitroaniline  and  naphthalene-/?- 
sulphonic  acid.  Paranitraniline  red  is  used  as  a 
substitute  for  the  red  Ck>nffo  dyestuffs  and  for 
Turkey  red.  It  is  extractea  from  the  fibre  when 
treated  with  oiganic  solvents,  and  when  the 
fibre  ia  heated  to  180^-200^  the  dyestuff  partly 
Bttbl&nes.  (For  the  formation  of  paranitraniline 
red,  see  Pomeranz,  Zeitsch.  Farben.  Ind.  1906, 
5,  184 ;  Erban  and  Mebus,  Chem.  Zeit.  1907, 
31,  663,  678,  687;  lichtenstein,  Zeitsch. 
Elektrochem.  1908,  14,  586 ;  Prud'homme  and 
Colin,  Rev.  Gen.  Mat.  Col.  1909,  13,  1,  66; 
Bull.  Soc.  chim.  1909,  (iv.)  5,  779 ;  Bucherer, 
and  Wolff,  Zeitsch.  angew.  Chem.  1909,  22,  731 ; 
Justin-Mueller,  Bull  Soc.  chim.  1910,  (iv.)  7,  60.) 
When  in  the  form  of  a  lake  it  is  known  as 
Pigment  Bed  G  (M.i);  Autol  Red  BGL  (B.); 
Sitan  Bed  (T.  M.). 

MeUnltraniUiie  Orange  and  Nitro-o-toluidine 
Orange.  Prepared  as  above  from  diazotised 
f»-nitroani]ine  or  |)-nitro-o-toluidine  and  fi- 
naphthoL  The  former  gives  yellowish  and  the 
latter  reddish  shades  of  orange.  Their  use  is 
not  very  extensive,  as  they  are  not  fast  to 
rubbing,  and  the  colours  sublime  on  keeping. 
An  orange  free  from  these  disadvantages  can, 
however,  be  obtained  by  using  m-nitro-j7- 
phenetidine. 

Nitro-o-toluidine  orange,  in  the  form  of  a 
lake,  is  soM  as  Pigment  Orange  B  (M.) ;  Fast 
Orange  (By.). 

NJtcrophenetldine  Bose  or  Blue-red.  Here 
o-nitro-j^phenetidine  is  used  as  the  diazotised 
base. 

Axophor  Bose  A  (M.)  is  the  stabilised  diazo- 
oompound  of  o-anisidine.  The  compound  of 
diazotised  o-anisidine  and  jS-naphthol  is  used  as 
a  lake  under  the  names  Pigment  Purple  A  (M.) ; 
Sudan  B  (A.). 

Naphthol  Bose  is  the  stabilised  diazo-  com- 
pound of  p-nitro-o-anisidine. 

Lftertrfttre.— E.  P.  26756  of  1897 ;  D.  R.  P. 
98637 ;  F.  P.  271908. 

Chloranlsidina  Scarlet  (M.)  is  produced  on 
the  fibre  by  the  aid  of  diazotised  p-chloro-o- 

Naphthylamlne  Bordeaux.  Prepared  on  the 
fibre  from  diazotised  a-naphthyjamine  *  and 
/3-naphthoL    The  dvestuff  is   used  also   as   a 

Sigment  colour  unaer  the  names  Carminaph 
iamet  (D.  H.),  Cerottne  Scarlet  2  B  (C.  J.),  &c. 
Axo  Turkey  Bed  is  produced  by  treating  cloth 
padded    with   i9-naphthol   with-  diazotised    0- 

^  See  p.  458  for  the  full  names  of  firms  of  which 
tlieee  letters  are  a  contraction. 

*  Finely  ground  a-naphthylamine  sulphate  is  sold 
as  «-Naidithylamine  salt  S,  and  a  stable  compound 
of  dlasotised  a-naphtbylamlne  with  a-naphthalene- 
dUulphonlc  add  as  x^apnthol  garnet  50  p.c.  paste. 


naphthylamine.    It  ia  a  bright  scarlet*  which, 
however,  is  not  very  fast. 

Fast  Axo  Garnet.  Prepared  from  diazotised 
o-aminoazotoluene  and  i3-naphthoL  It  is  also 
manufactured  in  substance  and  is  used  for 
colouring  oils  and  varnishes  under  the  names 
OU  Scarlet  (M)  (K)  (W),  Bed  B,  Oil  soluble, 
extra  cone.  (Remy),  Cerotine  Ponceau  8  B 
(C.  J.),  and  Fat  Poneeau  B  (K). 

Benzidine  and  Tolidlne  Puce.  Obtained  from 
tetrazotiaed  benzidine  or  tolidine  and  )3-naphthoL 
Dark  garnet  to  brown  shades  are  produced  which, 
however,  are  not  fast  to  light  Bather  yellower 
shades  result  by  using  tetrazotiaed  diaminocar- 
bazole  instead  of  these  diamines ;  when  treated 
with  copper  salts  the  tints  are  very  fast  to 
light 

Dianisidine  Blue.  Tetrazotised  diamsidine 
is  combined  on  the  fibre  with  iS-naphthol  in 
presence  of  copper  salts.  The  tetrazo-compound 
ia  sJso  put  on  the  market  as  Axophor  Blue  D, 
a  mizture  of  the  tetrazo-  compound  and  alu- 
minium sulphate  which  has  been  dried  in  a 
vacuum  at  45**.  The  .colour  is  very  fast  to 
light  soap,  and  rubbing.  Asophor  Blacic  S  is  a 
stabilised  mixture  of  the  tetrazo-  compound  of 
dianisidine  with  other  diazo-  compounds  (from 
benzidine,  p-nitroaniline,  and  especiaUy  m- 
nitroaniline,  cf,  D.  R.  P.  83963). 

The  production  of  black  insoluble  colours 
in  the  fibre  was  first  effected  by  the  Farbwerke 
vorm.  Meister,  Lucius  und  Briining.  The 
cloth  is  padded  with  iS-naphthol  and  tragacanth, 
and  treated  with  a  mixture  of  the  tetrazo- 
compounds  of  dianisidine  and  certain  other 
bases.  The  mixture  of  bases  sold  for  this 
purpose  is  known  as  Axo  BlaclE  Base  0,  and  the 
diazo-  compounds  are  put  on  the  market  under 
the  name  of  Axophor  Black  S.  Cassella  &  Co. 
have  introduced  a  black  obtained  by  padding 
the  cloth  with  1:6-  or  1 : 7-aminonaphthoi, 
and  then  passing  it  through  diazotised  ;p-nitro- 
aniline  so  as  to  form  the  diiukzo-  colouring  matter. 
The  aminonaphthol  is  put  on  the  market  as 
Amidonaphttiol  BD  and  8  B,  and  both  brands 
are  mixtures  of  the  two  aminonaphthols  men- 
tioned. Full  black  colours  are  obtained  which 
are  fast  to  soap  and  chlorine,  but  thev  are  not 
very  easily  applied  in  printing.  A  black,  also 
introduced  by  the  same  firm,  is  produced  ^m 
Azotol  C,  which  is  an  asymmetric  dialkylated 
di-p-diaminoazobenzene  (it  is  identical  with 
Kinzlberger's  Ice  Black).  The  base  is  diazo- 
tised and  combined  with  jS-naphthol  on  the 
fibre  in  the  usual  way.  The  latter  firm  also 
has  introduced  the  use.  of  the  diazo-  compound 
of  aminochrysoldine,  and  of  the  tetrazo-  com- 
pound of  j3!p-diaminodiphenylamine  for  the 
production  of  black  colours.  Other  tetrazo- 
compounds  recommended  are  these  of  amino- 
benzene-azo- a-naphthylamine  (By.)  and  diamino- 
dimethylcarbazole  (M.). 

Nigropbor  BASF  (B.).  Diazotised  2:6- 
dichloroaniline  is  combined  with  l-amino-8- 
naphthol-5-sulphonio  acid  in  acid  solution,  the 
monoazo-  dye  is  dissolved  in  sodium  hydroxide 
solution,  mixed  with  p-nitrophenylnitrosamine 
and  cloth  padded  with  the  solution.  After 
being  dried  and  exposed  to  the  air  a  greemsh- 
blaok  is  produced  on  the  fibre.  a-Naphthyl- 
amine  may  also  be  used  inst^ead  of  p-nitro- 
aniline. 


408 


AZO-  OOLOOBINO  MATTERS. 


Ltfera/ur^— £.  P.  1002  of  1805 ;  B.  R.  P. 
116676;  F.  P.  24424,  245211. 

Another  prooeas  of  producing  azo-  oolouring 
matters  on  the  fibre  is  by  the  nee  of  primn- 
line  iq.v.).  When  cotton  dyed  with  thu  d^e- 
■taff  ia  treated  with  a  solution  containmg 
hydrochloric  acid  and  sodium  nitrite,  the  dye- 
stuff  is  diazotised.  The  cloth  is  now  passed 
through  a  bath  oontainiiig  the  '  developer,' 
consiHting  of  a  solution  of  an  amine  or  a  phenoL 
/3-Naphthol  is  mostly  used  in  giving  Ingrain-  or 
Primulfaie  Red.  An  orange  colour  is  obtained 
with  resoroinol  (Ingrain  &ange),  and  a  brown 
with  m-phenylenediamine  (Ingrain  Brown). 
Hany  direct-dyeing  cotton  colours  which  contain 
a  (uasotiMble  amino-  group  (for  example, 
diamine  black  BH)  acquire  a  faster,  deeper, 
and  modified  shade  when  similarly  diaaotued 
on  the  fibre  and  developed  with  iS-naphthol 
or  m-phenylenediamine.  .1 

In  the  succeeding  portion  of  this  article  it  is  I 
proposed  to  sive  an  account  of  the  most  impor- 
tant aao-  cofours  which  are  at  present  in  com- 
merce. Each  colour  will  be  treated  of  under 
its  commercial  name;  its  chemical  formula 
given,  and  the  mode  of  preparation  and  general 
properties  briefly  described. 

Unless  otherwise  stated,  it  may  be  assumed 
that  colouring  matters  containing  a  sulphonic 
or  carboxylic  group  are  placed  on  the  market 
in  the  form  of  their  sodium  salts. 

The  following  abbreviations  are  used  for  the 
names  of  firms  ^  : — 


(H.) 


(A.) 
(B.) 
(B.EL) 
(By.) 
(C.) 
(C.  J.) 
(CI.  Co.) 
rClausft 


(D.) 
(D.  H.) 


(G.) 


«3  Aktiengesellschaft  fiir    Anilinfa- 

brikation,  Berlin. 
Bs  Badische     AniUn-     und     Soda- 

Fabrik,  Ludwigshafen  a/Rhein. 

B  Leipziger  Anilinfabrik  Beyer  k 
&egeL 

B  Farbenfabriken  vorm.  Fr.  Bayer 
&  Co.,  Elberfeld. 

Bs  Leopold  Cass  Ua  &  Co.,  Frank- 
furt a/Main. 

B  Carl  Ja^er,  6.  m.  b.  H.,  Dussel- 
dorf-Derendorf. 

B^he  Clayton  Aniline  Co.,  Ltd., 
Clayton,  Manchester. 

Co.)  Bs  Claus  &  Co.,  Clayton,  Man- 
chester (since  1917  amalga- 
mated with  Levinstein,  Ltd.). 

B  Wnlfing,  Dahl  &  Co.,  Barmen. 

B  Dye  Works,  formerly  L.  Durand, 
Hugueniu,  ft  Co.,  Basle. 

B  A.  Fischesser  ft  Co.,  Lutterbach. 

B  Aniline  Colour-  and  Extract- 
Works,  formerly  John  R. 
Geigy,  Basle. 


'  Since  the  Uat  editton  of  this  '  Dictionary '  was 
published  a  great  revival  of  the  Dye  Industry  has 
taken  place  in  Sngland,  France,  Italy,  America, 
Sweden,  and  Japan.  The  principal  new  companies 
which  have  been  formed  are  British  I^^,  Ltd. 
(later  Incorporated  with  Levinstein  Ltd.,  under  the 
name  of  British  Dyestuffs  Corporation,  LtdA  Com- 
paanle  Nationals  des  Matieres  Oolorantes  et  JProdults 
Obhnlques  (France),  Italian  National  DyestuH  Ck>. 
ataly).  The  NaUonal  AniUne  and  Chemical  Co.,  Inc. 
(America),  The  A.B.  Kemlsk  Industrie  (Sweden),  and 
The  Japan  Dyestuff  Co.  (Japan).  Other  new  firms 
manufacturing  aso-  colouxbg  matters  are  Indicated 
under  the  parUcular  dyes. 


(L) 

(K.) 
(K.  8.) 

(Ll) 
(Lev.) 


(M.) 
(N.  L) 
(0.) 


(P.) 


(Sch.) 


B  Read  Holliday  and  Sons,  Ltd., 
Huddersfield  (now  British  Dye- 
stuffs  Corporation,  Ltd.,  Hud- 
derfifield  branch). 

Bs  Soci^t^  pour  rindustrie  Chimique, 
(formerly  Bindschedler  und 
Busch),  Basle. 

B  Kalle  ft  Co.,  Biebrich  a/Rhein. 

Bs  Sandoz  ft  Ca  (formerly  Kern 
and  Sandos),  Basle. 

B  Farbweric  Mulheim  (formerly  A. 
Leonhardt  ft  Co.),  MUlheim, 
near  Frankfurt. 

mm  Levinstein,  Ltd.,  Blackley,  Man- 
chester (now  British  I^frestaffs 
Corporation,  Ltd.,  BlacUey 
branch). 

»  Farfowerke  vornL  Meister,  Lucius, 
und  Briimng,  HOchst  a/Main. 

Bs  Farbweik  Griesheim,  NOtiel, 
Istel  ft  Co.,  Griesheim  a/Main. 

es  Chemisohe  Fabrik  Griesheim- 
Elektron,  Work  Oehler  (for- 
merly  EL.  Oehler),  Griesheim. 

» Soci6t6  Anonyme  des  Matieres 
Colorantes  ft  Produits  Chi- 
miques  de  St  Denis,  Paris. 

Bs  The  SchOllkopf  Aniline  and 
Chemical  Company,  Buffalo, 
U.S.A.  (since  1917  is  included 
in  The  National  Aniline  and 
Chemical  Co.,  Lie,  New  Yoric). 

■B  Chemisohe  Fabriken  vorm.  Wei- 
ler  ter  Meer,  Uerdiogen  a/ 
Rhein. 

B3  Williams  Bros,  ft  Co.,  Hounslow, 
Kiddlesez. 

Also  E.  P.  s  English  Patent ;  D.  R.  P.  » 
German  Patent ;  F.  P.  »  French  Patent ;  A.  P. 
=3  American  Patent 

L  Baflio  Aso-  Comfouitds. 

Aniline  TeUow ;  Aminoaaobencene 

CgHg-N.-C-H.-NH, 
[if  [4] 

This  compound,  discovered  by  Mtoe  in  1861 
(/.c),  and  introduced  into  commerce  by  Simpson, 
Maule,  and  Nicholson  in  1863,  is  interestiug  as 
being  the  first  azo-  colour  made  on  a  manu- 
facturing scale.  It  was  formerly  prepared  by 
passing  nitrous  acid  gas  into  an  aloohoUc  solu- 
tion of  aniline.  As  a  oolouring  matter  it  is  now 
of  no  importance,  but  is  lately  used  as  the 
starting-point  in  tiie  manufacture  of  other  aso- 
colours  and  of  indulines.  In  practice  thia 
compound  cannot  be  prepared  directly  by  the 
action  of  one  molecule  of  nitrous  ada  on  two 
molecules  of  aniline, <since  diaaoaminobenaene  is 
always  the  first  product  of  this  reaction : 

2C,HgNHja[a+NaN0. 

-C,H,^N,NHC,H,+Naa-fHa-*-2H,0. 
The  diaio-  compound  is  slowly  converted  into 
the  isomerio  aniline  yellow  on  being  kept  for 
some  time  in  oontaot  with  aniline  and  an 
aniline  salt : 

C4H,N,NH-C,H.-C,H,N,-C,H4NH^ 


(T.  M.) 


(W.) 


AZO-  COLOURING  MATTBRa 


459 


The   manufactare  is  carried  out  as  fallows :  I  pheDylenediamina  hydroohloride  an  run  simul 


100  kilos,  of  aniline  are  mixed  with  86  kilos,  of 
concentrated  hydrochloric  acid,  the  mixture 
cooled  (from  outside)  to  about  18^  and  a  solution 
of  16'5  kilos,  ol  sodium  nitrite  in  18  kilos,  of 
water  and  18  Idlos.  of  saturated  sodium  chloride 
solution  added  at  first  fairly  rapidly,  so  that 
the  temperature  rises  to  26*,  and  then  more 
slowly,  Uie  temperature  being  kept  below  28* 
by  outside  cooling.  This  operation  takes  about 
7-^  hours.  After  24  hours  the  change  of 
diaioaminobeniene  into  aminoazobensene  is 
complete.  The  sait  solution  is  now  drawn  of^ 
the  residue  stirred  with  96  kilos,  of  hydrochloric 
acid  and  64  kilos,  ol  water,  and  the  aminoaso-^ 
beniene  hydroohloride  is  filtered  o^  washed  with 
2  p.c  hydrochloric  acid,  centrifused  and  dried 
at  60^.  The  yield  is  41  kilos,  of  dry  aminoazo- 
benzene  hydrocUoride.  The  old  aniline  yeUow 
was  the  oxalate  of  the  base.  The  free  base 
orvstallises  in  yellow  rhombic  prisms.  ILik 
127^*;  b.p.  above  300*.  The  hydrochloride 
orvstallises  in  steel-blue  needles.  Bass  slightlv 
soluble  in  hot  water,  readily  soluble  in  alcohoL 
Yellow  solution  coloured  red  by  hydroohloiio 
acid. 

LUeraiure. — ^Mtoe,  1861  {see  above);  Dale 
and  Garo,  £.  P.  3307  of  1863;  MarUus  und 
Griess,  Zeitsoh.  f.  Chem.  1866,  2,  132 ;  Kekul^ 
ibid.  2,  689;  Witt  and  Thomas,  Chem.  Soc. 
Trans.  1883,  43,  112 ;  Fiiswell  and  Green,  ibid. 
1886,  47,  917  ;  and  1886,  49,  746  ;  Stadel  and 
Bauer,  Ber.  1886,  19,  1963;  Paul,  Zeitsch. 
angew.  Chem.  1896,  9,  689;  Jansen,  Zeitsch. 
Farb.  Ind.  1913, 12, 197. 

Spirit  YeUow  R  (K.) ;  YeUow  Fat  Colour ; 
o-Aminoazotoluene 

CH,C,H4-N,-C,H,(CH,)-NH, 

Prepared  similarly  to  aniline  yellow,  from  o- 
toluidine. 

Ltferotiire.— Ber.  1877, 10,  662. 

Batkr  YeUow;  OU  YeUow  (W.):  Dimethyl- 
aminoazobehzene  C«Hs'N,'CcH4*N(CH,),.  Pie- 
pared  by  the  action  of  diazobenzene  chloride 
on  dimethylaniline.  Substance  forms  yellow 
leaflets  of  m.p.  116* ;  soluble  in  dilute  hydro- 
chloric acid  with  a  red  colour ;  precipitated  by 
aUcalL  Soluble  in  sulphuric  acid  ^  with  a 
yeUow  colour,  becoming  red  on  dilution. 

Li(eni<ttre.— Grisss,  Ber.  1877,  10,  628. 

Chryaoidliie  (most  firms);  Chiysoldlne  Y 
(H).  (W.)  (Harden,  Orth,  and  Hastings  Corp. 
New  York)  (Sch.) ;  Chrysoldbie  JEE  (GTj.)  (P.) ; 
Ctaiyioldlne  Ciystali  *;  Chryioldlno  SnudlCiystali 
(T.M.) 

Diaminoazobenzene  CgH|'N,*C,H,(NH.).. 

[1]  [2:4] 

This  colouiins  matter  is  prepared  by  mixing 
a  solution  of  diazobenzene  chloride  with  a 
solution  of  m-phenylenediamine.  In  practice 
a  known  weignt  of  aniline  is  dissolved  in 
dilute  hvdrochloric  acid  and  diazotised,  the 
solution  being  dUuted  so  as  to  contain  about  2-3 
p.&  of  diazo-  salt    This  and  a  dilute  solution  of 

*  In  tfaeae  cotonr  raacttons  'Bulpharic  acid '  meanf 
the  ordinary  ooDoeatrated  add  of  06  96  Dcr  cent. 


■  Ohi|rioIdlD6  Onttals  alio  contain  the  bomologuet    atifcution. 
tram  o.  and  j^-tdultflns.  I  sutouou. 


taneously  into  a  sodium  chloride  solution,  and 
the  colouring  matter  is  filtered  off  through  a 
filter  press.  The  press  cake  is  then  dissolved 
in  hot  dilute  hydrochloric  acid,  the  hot  solution 
filtered,  and  hydrochloric  acid  added  to  the 
filtrate.  The  chrysoldine  separates  in  smaU 
needles,  which  are  filtered  off,  centrifuged,  and 
dried  at  60^  The  free  base  forms  yeUow 
needles;  m.p.  117'6^  Slightly  solu&le-  in 
water,  readily  in  alcohol;  solutions  orange. 
The  commercial  product  is  the  hydrochloride 
GitHitN4,HCl,  which  forms  beautiful  blackish- 
green  prisms  with  a  metaUic  lustre.  The  strong 
solution  of  the  salt  solidifies  on  rapid  cooling  to 
a  red  jeUy.  Dissolves  in  sulphuric  acid  wiUi  a 
brownish-yellow  colour. 

I^ifercrture.— Hofmann,  Ber.  1877,  10,  213; 
Witt,  AidE.  360  and  664 ;  Griess,  ibid.  389. 

OhrysoUine  R  (H.)  (W.)  (G.)  (I.)  (Sch.); 
ChrysoXdina  REE  (P.) ;  Csrotliie  Orange  (C.  J.) ; 
Gold  Orange  for  Cotton  (T.  M.)  (D.  H.) ;  Benzens- 
azo-m-tolylenediamine 

C,H,-N,C,H,(CH,)(NH,), 

Prepared  from  aiuline  and  m-tolylenediamine 
as  in  the  preceding  case.  The  free  base  melts 
at  166^-166^  The  commercial  product  is  the 
hydrochloride,  which  forms  yeUowish-brown 
lumps.  Dissolves  in  sulphuric  acid  with  a 
grecmish-yeUow  colour. 

Chiysoldlne  R  (D.  H.)  (C.) ;  Tolueneazo-m- 
tolylenediainineCHa'CcH4Na-C,H,(CH,)(NHa)a. 
Prepared  as  above  from  o-toluidine  and  m- 
tolyienediamine.  The  commercial  product  is 
the  hydrochloride.  It  is  a  crystalline  violet 
powder  which  gives  a  brown  colour  in  sulphuric 
add. 

Heta  Chrome  Brown  B  (A.)  (Brotherton& 
Go.) ;  Dinitrophenolazo-m-tolylenediamine 

OHC,H,(NO,),-N,-C,H,(CH,)(NH,), 

Prepared  from  picramic  acid  and  Y?i-tolylene- 
diamine.  It  is  a  brown  paste  giving  a  dark 
orange-red  solution  in  hot  water.  It  yields  a 
red  solution  with  sulphuric  acid. 

Literature.— E,  P.  13213  of  1899 ;  10294  of 
1910 ;  D.  R.  P.  112819,  118013 ;  A.  P.  667064, 
667066. 

Chrome  Brown  P  (P.) ;  Dinitrophenolazo-m- 
aminophenolOHC.H^(NOa).-N.C«H,(OH)NH.. 
Prepared  from  picramic  acid  ana  m-aminophenol. 
Introduced  in  1903. 

Liieratwe.—D.  B.  P.  169679 ;  F.  P.  336669. 

Meta  Chrome  Bordeaux  R,  B  (A.).  Prepared 
from  diazotisedpicramic  add  and  a  m-aminoaryl- 
gnj^hamide.  The  R  brand  gives  an  orange- 
brown  solution  in  hot  water,  and  a  reddish- 
violet  solution  in  sulphuric  acid,  which  yields 
a  brown  precipitate  on  dilution. 

Literatwe.—E.  P.  4028  of  1902 ;  D.  R.  P. 
136016 ;  A.  P.  704826,  704826. 

Dlaiine  Green  S  (K.) ;  Janos  Green  B  (M.) ; 
Union  Green  B  (M.).  Prepared  from  diazotised 
aafranine  and  dimethylaniline.  The  commercial 
product  is  a  brown  or  dark-green  powder  giving 
an  olive-green  solution  with  sulphuric  add. 
Janos  Green  G  is  a  dyestuff  of  anak^oos  con- 


460 


AZO-  COLOURING  MATTERS. 


LiUrature.'-E.  P.  7337  of  1897;  F.  P. 
265438;  D.  R.  P.  95668. 

IL  ACZD  AXO-  COMFOirHDS. 

A.  SolplMMile  Adds  of  Amlnoaio-  Compoimds. 

Aeid  TeUow  (A.) ;  Fast  YeUow  (B.)  (By.) ; 
FtotYeUowG;  New  TeUow  L  (K.) ;  Yellow  SS 
(P.) ;  Fut  Yellow  eita  (By.).  This  colouring 
matter  is  a  mixture  of  the  sodium  salta  of  mono- 
and  di-  sulphonio  acids  ot  aminoazobenzene 

HS0,-C,H.N,CgH4-NH,  and 
HS0,C,H4'N,-C,H,(HS0,)NHg 

Prepared  by  the  action  of  fuming  sulphuric  acid 
on  aniline  yellow  (3-5  parts  acid  to  one-  of 
aminoazobenzene).  Solution  not  precipitated 
by  alkali;  colour  dissolves  in  sulphuric  acid 
with  a  brownish-yellow  colour  becoming  redder 
on  dilution.  Solution  gives  a  precipitate  with 
barium  chloride,  but  not  with  calcium  chloride. 
The  corresponding  colouring  matter  from 
anunoazotoluene  is  somewhat  more  orange  in 
shade,  and  is  known  as  Fast  Yellow  Y  (B.); 
Fast  YeUow  R  (K.). 

Xi7era/iire.--Gra88ler,  £.  P.  43  of  1879; 
A.  P.  253598  ;  D.  R.  P.  4186,  7094  ;  Chem.  Ind. 
1879,  2,  48,  346  ;  Griess,  Ber.  1882,  15,  2187 ; 
Kger,  Ber.  1889,  22,  847. 

Methyl   Orange   (Consolidated   Colour   and 

Chemical  Co.,  New  Jersey);    HeUanthin  (B.) ; 

Orange  in.  (P.)  (T.  M.)  (D.  H.)  (W.) ;    Gold 

Orange  (A.);    p-Sulphobenzeneazodimethylani- 

line  HSO.-C-H.N, C.H-N(CH,),.        Prepared 

W  (IJ  I4J 

by  the  aotioii  of  diazotised  sulphanilio  acid^ 

on  dimethylaniline.  Solution  of  colouring  matter 

orange,  and  not  precipitated  by  alkali ;   dilute 

acids   produce   a^^  crystalline   precipitate,    the 

crystals  having   a  violet   reflection   (the   free 

sulphonio   acid).    The   substance   dissolves   in 

sulphuric  acid  with  a  yellow  colour  becoming 

red  on  dilution. 

Literature,— Grieaa,  Ber.  1877,  10,  528. 

Orange  IV.  (most  finns);    TropsoUne  00 ' 
(C.) ;  Aeld  YeUow  D  (A.) ;  Orange  N  (B.)  (I.) ; 
Kew  Yellow  (By.) ;  p-Sulphobenzeneazodiphenyl- 
amine HS0,C,H4N,CgH4-NHC,H,.  Produced 
[4]  [11  ^      >      ^ 

by  the  action  of  diazotised  sulpnanilio  acid  on 
diphenylamine  dissolved  in  alcohol  or  crude 
carbolic  acid.  The  product  is  thrown  on  an 
open  filter,  the  paste  dissolved  in  concentrated 
aqueous  potassium  carbonate  and  precipitated 
by  adding  sodium  hydroxide.  The  colouring 
matter  is  not  very  readily  soluble  in  water; 
the  solution  is  yellow,  and  when  strong  deposits 
crystals  on  cooling.  Substance  diuolves  in 
sulphurio  acid  with  a  violet  colour,  becoming 
reader  and  giving  a  greyish  precipitate  of  the 
free  sulphonio  acid  on  dilution.  The  aqueous 
solution  of  the  substance  is  coloured  red  by 
dilute  adds. 

When  nitrated  this  colour  furnishes  a  mono- 
nitro>  derivative  together  with  a  mixture  of 
mono-,     di-,     and      tri-    nitrodiphenylamine ; 

^  For  dfttrftilftd  infonnaUon  on  the  manufactura  of 
snlphaDlIio  add  and  its  homologues  tee  Mflhlh&uaer, 
Dingl.  poly.  J.  1887»  204,  181  and  238 :  Paul,  ZeiUch. 
angew.  Chem.  1806,  0,  086. 


moderate  nitration  yields  a  yeUow  coJoonng 
matter  which  is  found  in  oommeroe  under  the 
names  of  Citronlne  (D.  H.)  (I.)  (L.)  (K.  8.)  (O.) ; 
Cnreameine  (A.);  Axollavlne  8  R  ex.  oono 
(T.  M.) ;  Citronlne  HE  (P.) ;  Indian  YeUow  R 
(By.)  (G!.)  (H.).  More  enerffetio  nitration  of 
Orange  IV.  furnishes  Aio  Aeld  Yellow  (A.); 
Axo  Yellow  (K.)  (K.  S.)  (M.) ;  Axo  YeUow  8  G, 
ex.  cone.  (T.  M.) ;  Cttronine  2  AEJ  (P.) ;  Aao- 
llavlne  S  new  (B.);  Indian  YeUow  O  (By.). 
Both  dyestuffs  are  ochre-yellow  powders  and 
give  with  sulphurio  acid  reddisn-violet  and 
nuigenta-red  solutions  respectively. 

MetanU  YeUow  (most  firms);  Orange  MN 
(I.) ;  TropaBoUne  G  (C.) ;  YeUow  M  (P.) ;  MetanU 
Yellow  GR  extra  (T.  M.) ;  fii-SulphobenzeneaEo- 
diphenylamine     ESO^'C^H^'Nj^'CJS^'^fR-C^Hi, 

[31  Uf  -5p 

Prepared  in  the  same  manner  as  the  preceding 
from  m-diazobenzenesttlphonio  add^  and  di- 
phenylamine. Aqueous  solution  oraAge,  giving 
no  precipitate  with  alkalis,  becoming  red  and 
precipitating  with  dilute  acids.  Dissolves  in 
sulphurio  acid  with  a  dnU  violet  colour,  becoming 
magenta-red  on  dUution. 

MetanU  YeUow  S ;  Add  YeUow  8  G  (O.) ;  is 

produced  by  sulphonating  the  preoeding  colour- 
ing matter. 

Liierature.-^E.  P.  1226  of  1879;  4966  ol 
1880;  Paul,  Zeitsch.  angew.  Chem.  1896,  9, 
686. 

MetanU  Yellow  Bromlnated  (P.).  Prepared 
by  the  action  of  bromine  on  metanil  yeUow;  has 
similar  reaction. 

Literature.— E.  P.  5696.  of  1882 ;  D.  R.  P. 
26642;  F.  P.  140114. 

Jaone  SoUde  N  (P.);  Sulphotolueneazodi- 
phenylamine        HSOt-CTHe*N.*CcH«*NHC,H^ 

Prepared  from  diazotised  |)-toluidine-o-sttlphonio 
acia  and  diphenylamine;  in  its  general  pro- 
perties it  resembles  the  two  preceding  dyes. 

Literature, — ^Boussin  and  Poirrier,  E.  P. 
4491  of  1878. 

ArehU  Substitute  V;  y-Nitrobenaeneago- 
a-naphthylamine-4-sulphonic  acid 

N0,C,H4N,CipH,(NHJHS0, 

Prepared  by  the  action  of  diazotised  o-uitro- 
aniUne  on  naphthioric  eicid '  in  weaklv  aoid 
solution.  Solution  precipitated  by  adds  and 
alk&lis.  Sulphuric  acid  gives  a  magenta-red 
solution,  becoming  browmsh  and  precipitating 
on  dilution. 

Literature. — Roussin  and  Poirrier,  E.  P. 
4490  of  1878 ;  D.  R.  P.  6715 ;  F.  P.  127221 ; 
Chem.  Ind.  1879,  2,  292. 

ArehU  Substitute  8  VN  (P.) ;  ;).Nitroben2en0- 
azo-a-naphthylaminesulphonic  acid 

NO,C,H4N,CioH,(NH,)SO,H 

Prepared  by  the  action  of  diazotised  p-nitro- 
aniline    on    a-naphthylamine-5-sulphonio   acid. 

^  m-AmhiobeazeQesulphoiilc  add  Is  preparsd  by 
sulphonatiiig  Ditrobenxene  and  redadng  the  s»4itn>- 
beiksenesulplioaio  add  thus  fonned. 

*  KapMhlonic  add  is  manof actund  on  a  large  scsls 
by  heating  naphthyiamine  add  lulphate,  mixed  with  a 
little  ozaAc  add,  to  about  180*. 


AZO-  COLOURINQ   MATTERS. 


461 


Forms  a  brown  powder  giving  a  rad  sohition  in 
water  or  solphiiric  acid. 

Liierature,—E.  P.  126fl2  of  1887 ;  D.  R.  P. 
46787  ;  P.  P.  185908. 

Aio  Cardinal  6  (A.);  p-Niirobenzeneazo- 
beniylethylanilinesulphomc  add 

NOg-C,H4N,-C.H4N(CgH,)CHg-C,H4SO,H 

Pnrpared  by  the  action  of  diazotiaed  |>-nitro- 
aniline  on  benzylethylanilinesolphonic  acid.  A 
brick-red  powder  givinff  a  reddish-yellow  solu- 
tion in  water  and  a  yellow  solution  in  sulphuric 
add,  beoomiug  red  on  dilution 

LUerature.—T).  R.  P.  appl.  A  3661. 

Falatina  Chrome  Brown  W  (B.);  Add 
AUnrine  Brown  B  (M.);  Anthraiqrl  Chrome 
Brown  D  (D.) ;  ^Sulpho-o-hydroxybenzeneazo- 
m-phenylenediamine 

SO,H-C,H,(OH)-N,-C,H,(NH,), 

Prepared  £rom  diazotised  o-aminophenol-p- 
sulphonio  add  and  m-phenylenediamine.  A 
black-brown  powder  dissolving  in  hot  water 
with  an  orange-brown  colour,  and  in  sulphuric 
add  to  give  a  dark  orange-brown  solution. 

LUerature.—A.  P.  628814 ;  D.  R.  P.  78409  ; 
F.  P.  284741. 

Omega  Chrome  Blaek  FV,  PB  (E.  S.); 
Omega  Chrome  Bine  B,  R  (K.  S.)  are  chrome 
colours  prepared  from  o-diazophenols  and  aiyl- 
1 : 8-naphtnylaminesulphonic  acids. 

LiUrtaure,—lL  P.  22738  of  1905 ;  D.  R.  P. 
176625  ;  F.  P.  359222  ;  A.  P.  841371. 

Add  Anthracene  Brown  R  (By.)  is  prepared 
from  diazotised  picramio  acid  and  substituted 
phen^lenediaminesulphonic  acids.  The  aqueous 
solution  is  reddish-brown,  and  that  in  sulphuric 
add  is  reddish- violet,  becoming  yellowish-brown 
on  dilution. 

Anthraeyl  Chrome  Green  (D.);  IMnitro- 
pheno]azo-a-naphthy]amine-4-8ulphonio  acid 

OH-CJH,(N6,),N,CioHs(SO,H)NH, 

Prepared  by  the  action  of  diazotised  picramic 
add  on  naphthionio  acid.  Solution  in  water 
is  reddish-brown,  and  in  sulphuric  add  bluish 
fiery  red. 

lAUraiwrt.—J>,  R.  P.  142163. 

Alkali  Brown  (D.) ;  Benzo  Brown  5  R  (By.) ; 
AlkaU  Brown  R  (L.  P.);  Primulineazo-m- 
phenvlenediamine  P^  *N,-GcH,(NH.),.  Pre- 
pared from  diazotised  primuline  or  dehydrothio- 
p-toluidinesulphonic  acid  and  m-phenylenedia- 
mine. Solution  brownish-red,  precipitated  by 
acids  or  alkalis.  Qives  a  bluish- violet  solution 
with  sulphuric  acid. 

Pyramine  Yellow  R  (B.)  Diazotised  primu- 
line is  combined  with  nitro-m-phenylenedlamine. 
Aqueous  solution  is  reddish-yellow,  and  solution 
in  sulphuric  acid  is  brownish-yellow. 

L%teratwre,—1&,  P.  8664  of  1894 ;  D.  R.  P. 
80973 ;  F.  P.  238340. 

Cotton  Orange  6  (B.) ;  Diazotised  primuline 
is  combined  with  m-phenylenediaminedisulphomo 
add.  It  gives  an  orange-yellow  solution  in 
water,  and  a  brownish-orange  in  sulphuric  acid. 

Liieralure.—E.  P.  14678  of  1893 ;  D.  R.  P. 
73369;  F.  P.  231694 ;  A.  P.  624262. 

>  Fstbe  residue  of  primuline. 


ApoDo Red (O.) ;  AreliOSiihittMeiiCra(C.): 
p '  Nitrobenzeneaso-a-naphthylaminedirolphonic 
acid,  N0,-C,H4-N,-C,A(NH,)(S0,H);.  Pre- 
pared from  diazotised  ]^nitroaniline  and  a- 
naphthylamine-4 :  6-  or  4  : 7-disulphonio  acid. 
Gives  a  brownish-red  solution  in  water  and  a 
magenta-red  in  sulphuric  add. 

Lit€rature.--E,  P.  9468  of  1887  A.  P. 
376392  ;  F.  P.  184638. 

Brilliant  Arehil  C  (C.) ;  Azimide  of  p-nitro- 
benzeneazo-1  :  S-naphthylenediaminediBulpho- 
nic  acid 

NO,-C^.N,-C»oH,(SO,H),Q\NH 

« 
Prepared  by  the  action  of  nitrous  add  on  the 
product  from  diazotised  p-nitroaniline  and 
1 :  8-naphthyIenediamine-3  :  6-di8ulphanio  add. 
A  brownish-red  powder  dissolving  in  water  with 
a  red,  and  in  sulphonio  add  with  a  blue,  solution. 
Literaiure,—E.  P.  24714  of  1893 ;  D.  R.  P. 
77426  ;  F.  P.  234837. 

Wool  Violet  S  (B.);  Dmitrobenieneazo- 
diethylmetanilic  add 

(NO,),C.H,-N,-C^rfSO,H)N(C,H,), 

Prepared  from  diazotised  2 : 4-dinitroaniline 
ana  diethylmetanilic  add.  A  bUck  powder 
giving  a  reddish- violet  solution  in  water  and  a 
scarlet-red  in  sulphuric  add. 

Literature.— E.  P.  6197  of  1894;  D.  R.  P. 
86071 ;  F.  P.  239096 ;  A.  P.  626666. 

Salmon  Red  (A.);  Methylbenzenylamino- 
thioxylenolazo-i3-naphthylamine-3  :  6-aisulpho- 
nic  acid 

(CH,),C,H,<^^^C,H,-N,-CxoH,(SO,H), 

GHg       NHg 

Prepared  from  diazotised  dehydrothio-m-xyli- 
dine  and  ^-naphthylamine-3  :  6-di8ulphonio  acid 
R.  Aoueous  solution  is  orange-red.  Gives 
violet  solution  in  sulphuric  add. 

Literature,-— Vavl,  Zdtsoh.  angew.  Chem« 
1896,  9,  680. 

BrmiantTenowS  (B.)  (T.  M.)  (B.  K.) ;  TeUow 
WR  (I.);  Cnreomine  (G.);  p-Sulnhobenzene- 
azodiphenylaminesulphonio  add.  Prepared  b^ 
sulphonatinp  oranse  IV.  Solution  in  water  is 
yellow  and  m  sulphuric  add  bluish-red. 

Literature.— D,  R.  P.  21903. 

Lanacyl  Violet  B  (C):  Disulphohydrozy- 
naphthaleneazoethyl-a-naphthylamme 

(HSO,),CxoH^(OH)N,-C|,H,-NH-C,H, 

Prepared  from  diazotised  1 :  8-aminonaphthol- 
3 :  o-disulphonic  acid  and  ethyl-a-naphthyl- 
amine.  Solution  in  water  is  reddish  violet,  and 
in  sulphuric  acid  is  greenish-blue. 

Literature.— E.  P.  12666  of  1896 ;  D.  R.  P. 
94288 :  F.  P.  267136. 

Tolyl  Blue  SR  (M.) ;  Sulphone  Add  Blue  R 
(By.).  Prepared,  as  the  preceding,  from  diazo- 
tised H-acid  and  l.phenylnaphthylamine-8- 
sulphonic  acid.  Solution  in  water  is  reddish- 
violet,  and  in  sulphuric  acid  dirty  blue.  The 
corresponding  colouring  matter  with  the  tolyl- 
substituted  acid  is  Tolyl  Blue  SB  (M.) ;  Sulphone 


462 


AZO-  COLOURING  MATTERS. 


Acid  Blue  B  (By.) ;  BrilUsiit  Clotb  Bine  in.  F 

(K.) ;  it  dissolyes  in  water  to  a  reddish-blue, 
and  in  sulphmio  aoid  to  a  dirty  violet  solution. 

Literature.— E,  P.  24830  of  1898 ;  D.  R.  P. 
76671,  108646. 

B.  Carboxylle  Adds  of  Amlnoazo-  Compounds. 

Tellow  fast-to-soap  (P.) ;  m-Garboxybenzene- 
azodiphenylamine 

C0,HC,H4N,CeH4NHC«H, 

Prepared  by  the  action  of  m-diazobenzoic  acid 
on  diphen3fiamine.  'Used  in  wool-dyeing  and 
eepedaUy  calico-printing ;  the  shades  are  very 
fast  to  soap.  A  orown  paste,  sparingly  soluble 
in  water.  Solution  TOComes  reddish-violet 
with  acids.  Dissolves  with  a  violet  colour  in 
sulphuric  acid,  becoming  red  on  dilution. 

LUertUure.—E.  P.  4621  of  1883 ;  D.  R.  P. 
299'  1 ;  F.  P.  167766 ;  A.  P.  297862. 

C.  Hydroqraio-  Compounds. 

Sudan  Brown  (A.)  (Sch.) ;  Brown  G  (C.  J.) ; 
Pyronal  Brown  (D,);  Oil  Brown  (Farbwerk 
Ajnmersfoort)  (Wiescher  &  Co.) ;  a-Naphthalene- 
azo-a-naphthol  CiqHf'Ni'CioHf'OH.  Prepared 
by  the  action  of  diazotised  a-naphthylamine  on 
a-naphthol  in  alkaline  solution. 

LUerature.—E,  P.  786  of  1878;  D.  R.  P. 
6411 ;  F.  P.  123148  ;  A.  P.  204799;  Frankland, 
Trans.  Chem.  Soo.  1880,  37,  762. 

Sudan  G  (A.)  (W.) ;  Carmlnaph  J  (D.  H.) ; 
Cerasine  Orange  G  (C);  Cerotine  TeUow  R 
(G.  J.);  Chiysoin  Insoluble  (P.);  Pyronal 
YeUow(I>.);  Oil  Orange  (I.) ;  Benzeneazoreeor- 
cinol  0«Hs;N,'GeH,(OH),.  Prepared  by  the 
action  of  diazobenzene  chloride  on  resorcinol  in 
alkaline  solution.  Solution  of  colouring  matter 
in  alkali  hydroxide  is  orange-y^ow,  giving  a 
brown  precipitate  with  acids.  Dissolves  in 
sulphuric  acid  with  a  yeUowish-brown  colour. 

JMeraiure. — ^Baeyer  and  Jager,  Ber.  1876,  8, 
161 ;  Tjrpke,  ibid.  1877,  10,  1676 ;  Wallach. 
ibid.  1881,  14,  24 ;  Wallach  and  Fischer,  ibid. 
1882,  16,  2814;  Meyer  and  Kreis,  ibid.  1883, 
16,  1329;  Liebermann  and  Kostanecki,  ibid. 
1884,  17,  880;  Heumann  and  Oeconomides, 
ibid.  1887,  20,  904 ;  WiU  and  PukaU,  ibid.  1120 ; 
Pukall,  tbid.  1147 ;  Fischer  and  Wimmer,  ibid. 
1678 ;  Will,  ibid.  1888,  21,  604 ;  Kostanecki, 
ibid.  3119. 

Sudan  I  (A.)  (K.)  (W.) ;  Carmlnaph  (D.  H.) ; 
Cerotine  Orange  G  (C.  J.) ;  Oil  Orange  (0.)  (Farb- 
werk Ammersfoort)  (Wiescher  &  Co.) ;  MotI 
Orange  R  (T.  M.);  J^onal  Orange  (D.); 
Spirit  Orange  (L.) ;  Searlet  B  (B.  K.) ;  OU  YeUow 
(Sch.);  Insoluble  Aniline  Orange  (P.);  Benzene- 
azo-/3-naphthol  GeHt'N,'CioHe*OH.  Prepared 
from  diazobenzene  chloride  and  jS-naphthol. 
A  brick-red  powder  insoluble  in  water.  Used 
for  colouring  oils,  &c. 

•  i/»teni/ur«.-— Liebermann,  Ber.  1883, 16, 2860 ; 
Denare,  Gazz.  chim.  ital.  1886,  16,  406 ;  Zincke 
and  Bindewald,  Ber.  1884, 17, 3031 ;  Zincke  and 
Rathgen,  ibid.  1886, 19, 2484  ;  Fischer  and  Wim- 
mer,  vbid.  1887,  20,  1679  ;  Weinbeig,  ibid.  3172 ; 
Jacobson,  ibid.  1888, 21, 416 ;  Meldola  and  East, 
Trans.  Ghem.  Soo.  1888,  63,  460 ;  Meldola  and 
Morgan,  ibid.  1889,  66,  603 ;   Goldschmidt  and 


Resell,  Ber.  1890,  23,  496;  Goldschmidt  and 
Brubaoher,  ibid.  1891,  24,  2306;  McPherson, 
Ber.  1896,  28,  2418;  Farmer  and  Hantzsch* 
ibid.  1899,  32,  3100;  Mohlau  and  Strohbach, 
ibid.  1900,  33,  806 ;  Goldschmidt  and  Keppeler, 
ibid.  894;  Mohlau  and  Kegel,  ibid.  2873; 
Betti,  Gazz.  chim.  ital.  1900,  30,  ii.  164. 

Pigment  Fast  Red  HL  (M.) ;  Hello  Fast  Red 
RL  (By.) ;  Uthol  Fast  Searlet  R,  RPN  (B.) ; 
Graphltol  Fast  Red  GAERR  (O.) ;  SItara  Fast 
Red  RL  (T.  M.) ;  m-Nitrotolueneazo-^-naphthol 

NO,G7HeN,G,oH,OH 

Prepared  from  diazotised  m-nitro-p-toluidine 
and  jS-naphthol.    Used  only  for  lakes. 

Liter€aure.—E.  P.  19100  of  1906 ;  D.  R.  P. 
appl.  F  20266 ;  F.  P.  367868. 

Tuseallne  Orange  G  (B.).  Prepared  from 
diazotised  m-nitro-o-anisidine  and  i9-naphthol  is 
used  in  calico-printing  and  as  a  lake. 

Sudan  II  (A.)  (K.);  Cerotine  Searlet  0 
(G.  J.) ;  MotI  Red  G  (T.  M.) ;  Pyronal  Red  R 
(D.) ;  Orange  RR  (B.  K.) ;  Insoluble  Xylidlno 
Poneeau  (P.) ;  Xyleneazo-i3-naphthol 

G,H,(GH,),-N,-GioH,OH 

Prepared  from  diazotised  xylidine  and  jS- 
napnthol. 

Carmlnaph  Garnet  (D.  H.) ;  Cerotine  Searlet 
2  R  (G.  J.) ;  00  Red  Brown  (Farbwerk  Ammers- 
foort) ;  Pigment  Bordeaux  N  (M.) ;  Autol  Red 
(B.);  Insoluble  Naphthylamlne  Poneeau  (P.); 
a-Naphthaleneazo-^-naphthol 

GioH/N,-GioH,-OH 

Prepared  from  diazotised  a-naphthylamine  and 
3-naphthol.  An  insoluble  paste  used  in  print- 
ing.   {See  also  Naphthylamlne  Bordeaux. 

Aiophosphlne  GO  (Bl).  Chloride  of  «- 
trimethylaminobenzeneazoresorcinol 

C1N(GH,),-G,H4-N,-G,H,(0H), 

Prepared  from  diazotised  m-aminophenyltri- 
metnylammonium  chloride  and  resorcinol.  Solu  • 
tion  m  water  is  yellowish-red,  and  in  sulphuric 
acid  brownish-red.  A  similar  dye  is  Aiophos- 
phlne  BRO  (M.). 

Literaiwre.—K  P.  14494  of  1896 ;  D.  R.  P. 
87267  ;  F.  P.  249227 ;  A.  P.  626913. 

New  Phosphlne  G  (G.);  «-Dimethylamino- 
tolneneazoresorcinol 

N(GH,),GH,GgH4N,GeH,(0H), 

Prepared  from  diazotised  p-aminobenzyldi- 
metnylamine  and  resorcinol.  Gives  a  yellowish- 
brown  solution  in  water  and  sulphuric  acid. 

•  Literature.— E.  P.  22672  of  1892 ;   D.  R.  P. 
70678  ;  F.  P.  226968 ;  A.  P.  616100. 

Tannin  Orange  R  (G.) ;  co-Dimethylamino- 
tolueneazo-iB-naphthol 

N(GH,),-GH,-G.H4-N,'CxoHo-OH 

Prepared  from  diazotised  p-aminobenzyldi- 
metnylamine  and  /3-naphthoL  A  brown  powder 
or  a  60  p.c.  paste.  Sparingly  soluble  in  water, 
with  a  brown  colour.  Giyes  a  yellowish-brown 
solution  in  sulphuric  add. 

Literature, — ^As  for  the  preceding  colour. 


AZO-  GOLOUKINO  KATTBRa 


463 


AnMbromllie  (G.) ;  Tetrahydroxyazoben- 
zene  0H-G,H4*Na'CcHa(0H)a.  Pzvparad  from 
diAzotised  }>-aminophenol  and  pyrogallol.  Com- 
mercial product  18  a  30  p.o.  pasto,  giving  a 
d^'k-yellow  solution  in  boiling  water.  With 
sulphuric  aoid  it_give8  a  brown  solution. 

LUerature.—R.  P.  11902  of  1893 ;  B.  R.  P. 
81109 ;  F.  P.  230937  ;  A.  P.  548460. 

Dfaudne  Blaek  (K.);  Safranineazophenol. 
Prepared  from  one  of  the  varieties  of  sairanine 
ana  phenol.  Its  solution  in  water  is  dark 
g^reen^lne,  and  in  sulphuric  acid  green. 

LUeraiure.'-Mon.  ScL  1886,  (iii.)  16,  984. 

Indolne  Blm  R  (B.)  (Q.) ;  Janus  Blae  (M.) ; 
MaphfUndone  (C.) ;  Vae  Blue  (H.) ;  Fast  Cotton 
Blue  B  (0.) ;  Indole  Blue  (A.)  (L.) ;  Dlazlne  Blue 
(K.) ;  Madras  Blue  P  (P.) ;  Indone  Blua  (By.) ; 
nst  Blue  B  (T.  M.) ;  Indogenln  (Delft  Ck>lour 
Works) ;  Safranineazo-^-naphthoL  Prepared 
from  various  safranines  and  iS-naphthol.  It 
ffives  a  violet  solution  in  water,  and  a  greenish- 
Brown  in  sulphuric  acid. 

lMerature.—E.  P.  4643  of  1891,  18769  of 
1893,  3488  of  1896,  23985  of  1898 ;  D.  B.  P. 
61692,  85690,  85932,  91721,  92015,  105433, 
108497 ;  F.  P.  212276,  245239,  250239,  283013, 
285360;  A.  P.  524251,  524254;  Walter,  Aus 
der  Praxis  der  Anilinfarbenfabrikation,  1903, 
306  (where  the  preparation  is  described  in 
detaU). 

Methyl  Indone  B,  R  (C.)  is  prepared  from 
diazotised  safranine  and  an  aminonaphthol. 
The  aqueous  solution  is  blue,  and  that  in  sul- 
phuric aoid  greenish-blue. 

lAteraiure.—Jy.  B.  P.  appl.  L  3377. 

Aiarine  S  (M.) 

OHC,H,a,NHN(80,-NHJ-CioH,-OH 

4 : 6-I>ichIoro-2-aminophenol  is  diazotised  and 
combined  with  iS-naphthol,  and  the  product  is 
treated  with  ammomum  bisulphite.  It  forms  a 
yellow  paste,  giving  a  yellow  solution  in  water 
and  a  magenta-red  solution  in  sulphuric  acid, 
giving  a  rwldish-brown  precipitate  on  dilution. 

Laeraiure,—E.  P.  5767  of  1883;  D.  R.  P. 
29067  ;  F.  P.  159604 ;  A.  P.  302790,  306546. 

Sulphamlne  Brown  A  (D.);  a-Naphthlne 
Brown  (P.)  is  prepared  by  the  action  of  diazo- 
tised a-naphthylamine  on  the  sodium  bisulphite 
compound  of  nitroeo-3-naphthol.  It  dissolves 
in  water  to  a  brown,  and  in  sulphuric  acid  to  a 
green,  solution.  Sulphamlne  Brown  B  (D.)  is 
made  from  iS-naphthvlamine ;  the  aqueous 
solution  is  red,  and  that  in  sulphuric  acid  is 
violet. 

LUeraiwre.—E,  P.  11556  of  1893;  D.  R.  P. 
79583  ;  F.  P.  239100. 

D.  Snlphonle  Acids  of  Hydroxyazo-  Compounds. 
1.  MoNosuLPHoiac  Acids. 

Chryioifn  (most  firms) ;  TropsBoline  0  (C.) ; 
Resorein  TeQow  (A.)  (B.  K.)  (K.)  (T.  M.)  (H.) 
(Sch.);  Gold  Yellow  (By.) ;  Acme  YeUow  (L.) ; 
p-Sulphobenzeneazoresorcinol 

HSO,0JEl4N,C,H,(OH), 

Produced  by  the  action  of  diazotised  sulphanilic 
acid  on  resorcinol  in  alkaline  solution.  Solution 
of  colouring  matter  orange ;  substance  dissolves 
in  sulphuric  acid  with  a  yellow  colour. 

Lii€raiure.--GneaB,  Ber.  1878,  11,  2195; 
Witt.  Trans.  Chem.  Soc.  1879,  35,  183. 


Add  Alizarine  Ganel  R  (M.);  p-Sulpbo- 
phenoUtsoresoroinol 

H80,-Cja,(0H)N,-C,H,(0H), 

Similarly  prepared  from  o-aminophenol-p-sul- 
phonic  acid  and  resorcinol.  Solution  in  water 
or  sulphuric  acid  is  orange-brown. 

Orange  II  (Most  firms);  Mandarin  G  (A.) 
(B.  K.)  (By.):  Gold  Orange  (By.)  (B.  K.)  (D.) 
(T.  M.);  Orange  Extra  (0.);  OraiueA(L.)(8ch.); 
Orange  P(0.);  Orange  G  (B.K.)  (H.);  Add 
Orange  (O.) ;  p-8ulphobenzeneazo-/i.naphthol 
H80,*0«H4*Ni*OioH|-OH.  Prepared  from  diazo- 
tised sulphaniuc  acid  and  3-naphthol.  Solution 
orange,  oecoming  red  on  addition  of  sodium 
hydroxide.  Solution  in  sulphuric  aoid  red, 
becoming  orange  on  dilution. 

Ltlero^ure.— Hofmann,  Ber.  1877,  10,  1378 ; 
Griess,  ibid,  1878, 11, 2198 ;  Witt,  ibid,  1879, 12. 
259 ;  Miller,  ibid,  1880,  13,  268 ;  Witt,  Chem. 
Zeit.  1880,  4, 437  ;  Muhlh&user,  Dingl.  poly.  J. 
1887,  264,  181,  238;  Paul,  Zeitsch.  angew, 
Chem.  1896,  9,  686  (the  last  two  papers  give 
detsils  of  the  manufacture). 

Orange  R  (I.)   (C.)  (D.   H.)   (B.)   (Sch.); 
Orange  T  (K.)  (T.  M.) ;  Kermedn  Orange  (L.) 
8ulpho-o-tolueneazo-)3-naphthol 

HSOa-C7H,-N,-CioH,OH(i9) 

Homoloffous  with  the  preceding,  the  diazotised 
sulphomc  acid  of  o-toluidine  being  used  instead 
of  sulphanilic  acid. 

Ltteraiure, — ^The  manufacture  is  described 
in  the  paper  by  Muhlh&user  already  referred  to. 

LItnol  Rublne  B  (B.) ;  Permanent  Red  4  B 
(A.);  Pigment  Rublne  R  (A.);  Sulpho-p-toluene- 
azo-/9-hydroxy-3-naphthoic  acid 

HSO,C,H.N,-C,oH,(OH)CO,H 

Prepared  by  the  action  of  diazotised  ;}-toluidine- 
Bulphonic  acid  (CH, :  KH.  :  SO,H=  1:4:3)  on 
/3-hydroxynaphthoic  acid.  A  fiery  red  powder 
or  paste  used  for  making  lakes. 

Literature,— E.  P.  11004  of  1903;  D.  R.  P. 
151205 ;  F.  P.  332145 ;  A.  P.  741029. 

Azofuchsine  B  (By.) ;  Tolueneazo-1 :  8-dihy- 
drozynaphthalenesulphonic  acid 

CH,0,H4N,CioH4(OH),-SO,H 

Prepared  by  the  action  of  diazotised  commer- 
cial toluidine  on  1 :  8-dihydrozynaphthalene-4- 
Bulphonic  acid.  Solution  in  water  is  bluish- 
red,  and  in  sulphuric  acid  violet. 

Literature.'^K  P.  18517  of  1889 ;  D.  R.  P. 
54116 ;  F.  P.  203744 ;  A.  P.  466841,  468142. 

Ponceau  4  GB  (A.)  (Lev.)  (B.K.);  Crocdne 
Orange  (By.)  (B.  K.)  (K.)  (P.) ;  CroceVne  Orange 
Y(Sch.);  Crocd'ne  Orange  GR(T.M.);  Brilliant 
Orange  G  (M.)  (C.  J.);  Orange  GRX  (B.); 
Pyrotlne  Orange  (D.) ;  Benzeneazo-/3.naphthoU 
sulphonic  acid  C,Hj-N,CioH.(80,H)-OH(/i). 
Prepared  by  the  action  of  diazobenzene  chloride 
on  ^•naphtnol-6-sulphonic  aoid  (Sch&ffer's  acid) 
in  alkaline  solution.  Solutions  in  water  or 
sulphuric  acid  are  orange-yellow. 

Literature,— Oiieaa,  Ber.  1878,  11,  2197. 

Orange  GT  (By.) ;  Orange  RN  (C.) ;  BriQIant 
Orange  0  (M.) ;  Brilliant  Orange  RO  (0.  J.) ; 
Croedne  Onnge  R  (Bv.)  (T.  M.) ;  Tolneneazo-^- 
naphtholsulphonic  acid 

C,H,N,'C,pH,(S0,H)0HO) 


464 


AZO-  COLOURINQ  MATTERS. 


Prepared  by  diazotising  commercial  tolnidien 
and  combining  with  Schaffer^s  /8-naphtholmono- 
sulphonic  acid  in  alkaline  solution.  Orange 
aqueous  solution  gives  an  oily  precipitate  with 
acids.  Dissolves  in  sulphuric  acid  with  a 
magenta-red  colour,  giving  an  oily  deposit  on 
dilution. 

Literature:— -K  P.  623  of  1879 ;  Ber.  1880, 
13,  586. 

Seariet  GR  (A.) ;  Scariet  R  (By.) ;  BrlUlant 
Orange  R(M.)  (C.  J.)(B.K.);  Orange  L  (Lev.) 
(P.)  (O.) ;  Xylidlne  Orange  2  R  (T.  M.) ;  Orange  N 
(K.)  (B.) ;  Ponceau  2  G  (B.).  Homologous  with 
the  last;  prepu^  from  diazotised  r^lidine 
and  Schafifer's  acid.  Dissolves  in  sulphuric 
acid  with  a  red  colour,  becoming  brown  and 
precipitating  on  dilution. 

Literature. — ^Levinstein,  Ber.  1880,  13,  686. 

Azoeoeelne  2  R  (A.) ;  Doable  Scarlet  R  (Lev.) ; 
Jote  Scarlet  (D.) ;  Ponceaa  R  for  Jute  (B.) ; 
Xyleneazo-a-naphtholsulphonic  acid 

(CH,),C,H,-N,-C,oH5(SO,H)-OH(o) 

Prepared  bv  the  action  of  diazoxylene  chloride 
(commercial  zylidine  diazotised)  on  a-naphthol- 
4-sulphonic  acid  in  alkaline  solution.  Aqueous 
solution  not  precipitated  by  alkalis ;  when  hot 
and  concentrated  deposits  bronzy  crystals  on 
coolinff.  Dissolves  in  sulphuric  acid  with  a 
reddish- violet  colour,  becoming  brown  and  pre- 
cipitating free  acid  on  dilution. 

Literature.—'E,  P.  2237  of  1883 ;  D.  B.  P. 
26012. 

Cochineal  Scarlet  4  R  (Sch.).  Isomeric  with 
the  preceding,  a-naphthol-6-sulphonic  acid  being 
used  instead  of  the  4-sulphonic  acid.  Dissolves 
in  sulphuric  acid  with  a  magenta-red  colour, 
giving  a  precipitate  on  dilution. 

Azoeoslne  G  (K.)  (By.)  (Lev.);  Cochineal 
Seariet  R  (D.);  Buffalo  Flamlne  G  (Sch.); 
Anisoleazo-a-naphthol-4-sulphonic  acid 

CH,OC.H,N,-C,oH5(SO,H)-OH 

Prepared  from  diazotised  o-anisidine  and  a- 
naphthol-4-sulphomc  acid.  Gives  a  red  solution 
in  water  and  a  carmine-red  in  sulphuric  acid. 

Literature,— E,  P.  2237  of  1883. 

Benzoyl  Pink ;  Rose  de  Benzoyl  (P.) ;  Benz- 
oylaminoditolylazo-a-naphthol-4-sulphonic  acid 

C,H5CONHC,H4CJi4N,-CioH,-OH 


i) 


H,  CH,        SO,H 


Prepared  from  diazotised  monobenzoyl-o-toli- 
dine  and  a-naphthol-4-8ulphonic  acid.  A  brick- 
red  paste,  givinff  a  cherry-rod  solution  in  water, 
and  a  bluisn*red  solution  in  sulphuric  acid. 

Literature,— J).  R.  P.  60332. 

Double  Ponceau  R,  2  R,  8  R,  4  R  (By.) ; 
a-Naphthaleneazo-a-naphthol-5-sulphonic  acid 
CioH^N,-CioH5(SO,H)^OH.  Prepared  from  di- 
azotised a-naphthylamine  and  a-naphthol-5- 
sulphonic  acid.  Gives  an  orange-red  solution  in 
water,  and  a  red  in  sulphuric  acid. 

Ftot  RedBT  (By.)  (Lev.)  (D.  H.)  (B.  K.) ;  a- 
Naphthaleneazo  -  j8  -  naphthol  -  6  -  sulphonic  acid. 
Isomeric  with  the  preceding.  Prepared  from 
diazotised  a-naphthylamine  and  /9-naphthol-6- 
sulphonic  acid  (Schafier).  Gives  a  red  solution 
in  water  and  a  violet  in  sulphuric  acid. 

Literature.— E.  P.  786  of  1878;  D.  R.  P. 
5411  ;  F.  P.  123148 ;  A.  P.  204799. 


Pigment  Seariet  G  (M.);  Garbozybenzene- 
azo-jS-naphthol-6-sulphonic  acid 

CO,HC,H4-N,C,oH,(80,H)OH 

Prepared  from  diazotised  anthranilic  add  and 
Schaffer  salt.  A  bronzy-red  powder  giving  a 
yellowish-red  aqueous  solution  and  used  for 
the  preparation  of  lakes. 

Literature.— J>.  R.  P.  175828;  P.  P.  366110. 

Fast  Brown  N  (By.) ;  Chrome  Brown  RO  (M.) ; 
Naphthylamlne  Brown  (B.) ;  p-Sulphonaphtha- 
leneazo-a-naphthol  HSO,'CioH«'N,'GioM«'OH. 
Prepared  by  the  action  of  diazotised  a-naph- 
thybkmine^t-sulphonic  acid  (naphthionic  acid) 
on  a-naphthol  m  alkaline  solution.  Golouring 
matter  gives  a  reddish-brown  solution,  not 
changed  Dv  acids  or  alkalis.  Dissolves  in  sul- 
phuric acid  with  a  reddish- violet  colour. 

Literaiure,—E.  P.  786  of  1878;  D.  R.  P. 
5411,  87003 ;  F.  P.  123148 ;  A.  P.  204799. 

FM  Brown  8  B  (A.) ;  Saiphonaphthalehe-2- 
azo-a-naphtholHSO,C„JI,-N,-CioH,-OH.  Pre- 
pared by  the  action  of  diazotised  J9-naphthyl- 
ainine-6-sulphonic  acid  on  a-naphthol  in  alkaline 
solution. 

Aqueous  solution  brownish-red,  becoming 
violet  with  dilute  acids  and  red  with  alkalis. 
Solution  in  sulphuric  acid  blue,  giving  reddish- 
violet  precipitate  on  dilution. 

Ltfeftrfitrc— E.  P.  3724  of  1882 ;  D.  R.  P. 
22547  ;  F.  P.  150503  ;  A.  P.  332829. 

Permanent  Orange  R  (A.);  Ghloroeulpho- 
benzeneazo-jS-naphthol 

HSOa-O.H,ClN,-CioHe-OH 

Prepared  from  diazotised  m-chloroanilina-o- 
sulphonic  ^d  and  iB-naphthol.  It  is  an  orange 
paste  used  for  maldng  lakes. 

Fast  Orange  0  (M.) ;  Nitrosulphobenzenoaco- 
^-naphthol 

H80,'C,H,(NO,)N,-CioH,OH 

Prepared  from  diazotised  o-nitroaniline-p-sul- 
phonic  acid  and  jS-naphthol.  An  orange  powder 
used  for  making  lakes. 

Literature.— E.  P.  16409  of  1901 ;  D.  R.  P. 
129539  ;  F.  P.  313598  ;  A.  P.  714883. 

Lake  Red  P  (M.) ;  Isomeric  with  the  pre- 
ceding. Prepared  from  diazotised  p-mtro- 
aniline-o-sulpnonio  acid  and  j3-naphthoL  It  is  a 
yellowish-red  paste  used  for  making  caldum 
and  barium  lakes. 

LUeraiure.—E.  P.  16409  of  1901 ;  D.  R.  P. 
128466  ;  F.  P.  313598  ;  A.  P.  714882. 

Uike  Red  C  (M.) ;  Ghlorosulphotolueneazo- 
j8-naphthol  HSO,*C7H4aN,C,oH,-OH.  Pre- 
pared from  diazotised  6-chloro-3-toluidine-4- 
sulphonic  acid  (CH,=  1)  and  /3-naphthol.  An 
orange  paste  used  for  making  the  red  barium 
lake 

Literature.— E.  P.  23831  of  1902 ;  D.  R.  P. 
145908 ;  F.  P.  328131 ;  A.  P.  733280. 

Chrome  Fast  Cyanlne  G  (I.),  introduced  into 
commerce  in  1907,  is  prepared  by  the  action  of 
diazotised  l-amino-2-naphthdsulphonic  acid  on 
a-naphthol. 

&loohrome  Blue  Black  B  (G.);  Sulpho- 
naphtholazo-a-naphthol. 

HSO,-OioH«(OH)'N,-C,oH,OH 
Prepared  by  the  action  of  diazotised  1 -amino- 


AZO-  COLOURING  MATTERS. 


466 


/i-iiaphtihol-4-suIphonic  acid  on  a-naphthol.^ 
The  Dlackish-violet  aqueous  solution  on  addition 
of  hydiochlorio  acid  becomes  first  reddish- 
brown,  and  then  eives  a  brownish-black  pre- 
dpitate.  With  somum  hydroxide  the  solution 
becomes  first  blue  and,  on  adding  excess,  finally 
red.  The  solution  in  sulphuric  acid  is  blue, 
giving  a  violet-black  precipitate  on  dilution. 

LUerature.—E.  P.  16025  oi  1904 ;  D.  R.  P. 
181326  ;  F.  P.  350056  ;  Ital.  P.  73530  ;  Aust. 
P.  30630. 

.Erioehrome  Black  T  (G.);  Nitrosulpho- 
naphtholazo-a-naphthol 

NOg-C,oH4(SO,H)N,C,oH,-OH 

Prepared  by  the  action  of  diazotised  8-nitro-l- 
amino-;8-naphthol-4-sulphonic  acid  on  a-naph- 
thol.  The  reddish-brown  aqueous  solution 
gives  a  violet-brown  precipitate  with  hydro- 
chloric acid,  and,  with  sodium  hydroxide, 
becomes  first  deep-blue  and  then  red.  The 
solution  in  sulphuric  acid  is  blackish-blue, 
giving  a  brown  precipitate  on  dilution. 

lMerature.—E,  P.  15982  of  1904 ;  D.  R.  P. 
169683  ;  F.  P.  350071 ;  Ital.  P.  73531 ;  Aust.  P. 
127191. 

Double  BrilUant  Scarlet  0  (A.)  (Lev.)  (K.) 
(T.  M.)  (A.);  Scarlet  for  sUk  (M.);  Double 
Scarlet  (D.).  Prepared  from  /3-naphthylamine- 
6-8alphonio  acid  and  /3-naphthol.  Aqueous  solu- 
tion ojivee  brown  precipitate  with  dilute  acids. 
Dissolves  in  sulphuric  acid  with  a  red  colour, 
giving  a  brown  precipitate  on  dilution. 

^tenrfure.— E.  P.  3724  of  1882 ;  D.  R.  P. 
22547  ;  F.  P.  150603  ;  A.  P.  332829. 

FM  Red  cone.  (Sch.) ;  Fast  Red  A  (B.) 
(C.  J.)  (Lev.)  (B.  K.)  (By.)  (Glaus  &  Co.)  (L.)  (K.) 
(D.)  (T.  M.)(0.) ;  Roeeelllne(D.  H.)  (B.K.)  (C.) 
(L)  (G.)  (P.)  (K.  S.)  (T.  M.)  (Central  Dyestuff 
and  Chemical  Co.) ;  Fast  Red  AV  (B.) ;  Fast 
Red  O  (M.);  Cardinal  Red  (H.);  Rubldlne 
(B.  K.) ;  Sulphoni^hthaleneazo-jS-naphthol 

HSO.CioH.N.CioH.OH 

Prepared  by  the  action  of  diazotised  naphthionio 
aoid  on  /3-naphthol  in  alkaline  solution.  Sub- 
stance dissolves  in  hot  water  with  a  reddish- 
biown  colour;  concentrated  solution  when 
rapidly  cooled  solidifying  to  a  brown  gelatinous 
mass.  Soluble  in  sulphuric  acid  with  a  violet 
colour,  becoming  brown  and  giving  a  psecipitate 
of  the  free  acid  on  dilution.  The  corr^ponding 
colouring  matter  from  a-naphthylamine-5-sul- 
phonic  acid  is  called  Brffllant  Fast  Red  G  (B.). 

Lttefoittfe.— E.  P.  786  of  1878;  D.  R.  P. 
6411 ;  F.  P.  123148 ;  A.  P.  204799  ;  Griess,  Ber. 
1878,  11,  2199;   1879,  12,  1364. 

Add  Ponceau  (D.  H.)  (K.  S.) ;  Ponceau  for 
Silk  (P.) ;  Ponceau  S  for  silk  (I.) ;  Ponceau  G 
for  SUk  (K.) ;  Scarlet  for'SUk  (B.) ;  Sulpho-i9- 
naphthaleneaco-/3-naphthol 

HSO,-C,oH,N,C,oH,OH 

^  In  the  oonstltntional  formula  of  this  colpuring 
matter,  kindly  oommimicated  along  with  other  Informa- 
tion to  the  writer  by  the  manufacturers,  the  axo-  gtony 
is  shown  attached  to  the  2-  position  of  the  «-naphUiol. 
although  the  4-  position  is  unoccupied.  The  combina- 
tion is  probably  effected  hi  presence  of  yery  concentrated 
alkali  hydroxide.  Other  examples  of  this  ortlio-  oom- 
bhiation  are  known,  both  hi  the  benxene  and  napntna- 
lene  series.  (Compare  Michel  and  Orandmougln,  Ber. 
1808,  2C,  2353 ;  Bamberger,  iMd.  1900. 83,  3188  ;  Bam- 
beiger  and  Mehnberg,  Urid.  1805.  28. 1889 ;  Bamberger, 
ihid.  S4Si  D.  &.  P.  14448.) 

Vol.  L— r. 


Prepared  by  sulphonating  i9-naphthylamine, 
diazotisinff  the  mixed  iBomeric  sulphonio  aoida, 
and  oomblning  with  iS-naphthol  in  alkaline 
solution.  Aqueous  solution  gives  a  brown  pre- 
cipitate with  dilute  acids.  Dissolves  in  sul- 
phuric acid  with  a  red  colour,  becoming  brown 
and  precipitating  on  dilution. 

Lithol  Red  R  (B.) ;  Sulphonaphthaleneazo- 
/S-naphthol  HSO,C,oH,N,C,oHeOH.  Pre- 
pared by  the  action  of  diazotised  /S-naphthyl- 
amine- 1 -sulphonio  acid  on  iS-naphthol.  The 
commercial  product  is  a  paste  which  is  only 
very  sparingly  soluble  even  in  hot  water.  It 
is  used  exclusively  in  the  manufacture  of  lakes. 

Literature.— K,  P.  25611  of  1899;  4859  of 
1909;  7922  of  1910;  D.  B.  P.  112833 ;  F.  P. 
297330  ;  A.  P.  650767. 

Lake  Bordeaax  B  (M.).  Prepared  from  the 
same  diazo-  compound  as  the  preceding  and 
)3-hydroxynaphthoic  acid.  It  is  a  boraeaux- 
red  paste  used  for  making  lakes. 

Literature.— E.  P.  7361  of  1907 ;  D.  R.  P. 
205080 ;  F.  P.  385570 ;  A.  P.  858065. 

Clayton  Cloth  Red  (CI.  Co.);  Stanley  Red 
(CI.  Co.) ;  Titan  Scarlet  (H.) ;  Sulphobenzenyl- 
aminothiocresolazo-iS-naphthol 

CH,C,H,/  Vc.H4(SO,H)N,CioH«-OH 

^S^ 

Prepared  by  the  action  of  diazotised  dehydro- 
thio-p-toluidinesulphonio  acid  on  iS-naphthol. 
The  commercial  product  is  the  ammonium  salt. 
Forms  a  reddish-orown  solution  in  water,  and  a 
violet-red  with  sulphuric  acid. 

Literature.— E.F.  18901  of  1889;  D.  R.  P. 
51331. 

Add  Alizarine  Violet  N  (M.);  Palatine 
Chrome  Violet  (B.) ;  Anthracene  Chrome  Violet 
B  (C.) ;  Ortho  Cerise  B  (A.) ;  Copper  Red  N 
(M.) ;  Sulphophenolazo-/3-naphthol 

OHC,H,(SO,H)N,CioH,OH 

Prepared  from  diazotised  2-aminophenol-4- 
sulphonio  acid  and  /3-naphthol.  Aqueous  solu- 
tion is  dark  bordeaux-red,  and  solution  in 
sulphuric  acid  is  magenta-red. 

Literature.— J>.  R.  P.  78409 ;  D.  R.  P.  appl. 
A  7938;  F.  P.  310608. 

Add  Alizarine  Black  R  (M.) ;  Nitrosulpho- 
phenolazo-i3-naphthol 

OHC.H,(NO,)(SO,H)N,CioH,-OH 

Prepared  from  diazotised  6-nitro-2-am]nophenol- 
4-siQphonio  aoid  and  i8-naphthol.  Aeneous 
solution  is  brownish-violet,  and  solution  in 
sulphuric  aoid  is  reddish- violet. 

Literaiure,—E.  P.  2772  of  1900 ;  D.  R.  P. 
143892  ;  F.  P.  300011 ;  A.  P.  667935. 

Anthracene  Chrome  Black  (C);  Sulpho- 
naphtholazo-iB-naphthol 

HSO,CioH5(OH)-N,CioH,-OH 

Prepared  by  the  action  of  diazotised  3-amino- 
/3-naphthol-7-sulphonic  acid  (R.)  on  /S-naphthol.* 
Aq ueous  solution  is  red ;  hydrochloric  acid  gives  a 
reddish- violet  precipitate,  and  sodium  hydroxide 
turns  it  bluish-violet.  Solution  in  sulphuric 
acid  is  bluish-green,  giving  a  reddish-violet 
precipitate  on  dflution. 

literature.— E.  P.  28107  of  1897 ;  D.  R.  P. 
109932  ;  F.  P.  272620,  272621. 

2  H 


466 


AZO-  COLOURING  MATTEBS. 


PiUttne  Chrome  BlMk  6  B  (6.) ;  Eriochrome 
Blae  Blaek  R  (G.) ;  SaUein  BUek  (K.) ;  Add 
Alizarin  Blue  BUek  A  (M.);  Diamond  Blue 
Blaek  EB  (By.);  Anthraeene  Bine  Blaek  BE 
(C);  Chrome  Fast  Blaek  PW  (I.);  Chrome 
Bine  N  (P.)*  Isomerio  with  the  preceding. 
Prepared  from  diazotised  l-ammo-/3-naphthoi- 
4-8alphonio  add  and  j^-naphthol.  Blue  aqueous 
solution  giyes  yeUowieh-brown  precipitate  with 
hydroohlorio  acid,  and  turns  first  blue  and  then 
red  with  sodium  hydroxide.  Solution  in  sul- 
phuric acid  is  dark-blue,  giving  a  blackish-brown 
precipitate  on  dilution. 

lMerature,—E,  P.  27372  of  1003 ;  4997  and 
10025  of  1904;  D.  B.  P.  156440,  160536, 
181326, 171024, 188645, 190693, 181714, 189175 ; 
D.  R.  P.  appl.  G  21484 ;  F.  P.  338819,  350056 ; 
A.  P.  770177. 

Salldn  Blaek  UL  (K.)  Ib  the  zinc  sodium  salt 
of  the  above,  and  is  prepared  by  diazotising 
l-amino-/8-naphthol-4-sulpnonic  acid  with  zinc 
nitrite  and  combining  the  diazo-oompound  with 
/3-naphthol  in  concentrated  alkaline  solution. 

LUeraiurt.—K.  P.  23034  of  1905 ;  22200  of 
1909 ;  D.  R.  P.  175593,  196228  ;  F.  P.  353786  ; 
A.  P.  807422;  Tomioka,  J.  Soc.  Chem.  Ind. 
1917,  36,  1043. 

Brioehrome  Blaek  A  (G.);  Nitrosulpho- 
naphtholazo-iB-naphthol 

NO,CioH4(SO,H)(OH)N,-CioH,OH. 
Prepared  from  diazotised  8-nitro-l-amino-/3- 
naphthol-4-sulphonic  acid  and  /3-naphthol. 
Dark-blue  aqueous  solution  gives  a  reddish- 
brown  precipitate  with  hydrochloric  acid,  and 
becomes  cherry-red  with  sodium  hydroxide. 
Solution  in  sulphuric  acid  is  dark-violet  blue, 
giving  a  brown  precipitate  on  dilution. 

LSera/ur«.— E.  P.  15982  of  1904 ;  D.  R.  P. 
169683  ;  F.  P.  350071 ;  A.  P.  790363  ;  Ital.  P. 
73531 ;  Aust.  P.  27191. 

Diamond  Blaek  PV  (By.) ;  Sulphophenolazo- 
1 : 5-dihydroxynaphthalene 

OH-C^,(SO,H)N,CioH»(OH), 

Prepared  from  diazotised  o-aminophenol-p-sul* 
phonic  acid  and  1  :  5-dihydroxynaphthalene. 
The  azo-  group  enters  the  2-po8itidn  in  the  latter 
component.  Blmsh-red  aqueous  solution  gives 
a  dark-red  precipitate  with  hydrochloric  acid. 
Solution  in  sulphuric  acid  is  blaokish-green, 
giving  a reddiidiprecipitate  on  dilution. 

IMerature,—i.  P.  18139  and  18569  of  1902  ; 
Fischer,  J.  pr.  Chem.  1917,  Tii]  95,  261. 

Am  Aeld  Blue  (M.)  (By.) ;  Ethyl  Add  Bine 
RR  (B.).  Is  prepared  by  the  action  of  diazo- 
tised p-nitroaniline  on  1 :  8-dihydroxynaphtha- 
lene-4-sulphonio  add,  reducing  the  nitro-  group 
and  alkylating  the  product,  or  by  the  action  of 
diazotised  dialkyl-p-phenylenediamine  on  the 
sulphonic  acid.  It  gives  a  blue- violet  solution 
in  water  and  a  reddish-violet  in  sulphuric  acid. 

LOercrfvrc.— E.  P.  8270  of  1892 ;  D.  R.  P. 
70885,  77169 ;  F.  P.  221363  ;  A.  P.  567615. 

Milling  YeUow  (Lev.)  (D.)  (L.);  Chrome 
YeUow  D  (By.) ;  Anthraeene  Yellow  BN  (C.) ; 
Mordant  Yellow  (B.)  (M.) ;  Chrome  Fait  YeUow 
R(A.);  SaUeIn  YeUow  D  (K.) ;  AUiarol  YeUow 
(Sch.) ;  SulphonaphthaleneazosalicyUc  acid 

HSO,CioH.N,C.H,(CO,H)-OH 

Prepared  by  the  action  of  diazotised  /9-naphthyl- 
amine-6-(or  5-)-sulphonic  acid  on  salicylic  acid. 


Solution  in  water  is  yeUow,  and  in  snlphnrio 
acid  yeUowish-red. 

LUerature.'—V.  P.  206755. 

Oriol  YeUow  (G.) ;  Cotton  YeUow  R  (B.) ; 
AUcaU  YeUow  (D.).  Prepared  by  the  action  of 
diazotised  dehydrothio-p-toluidineeulphonic  acid 
or  primuline  on  salicyUc  add.  Gives  an  oran^ 
yellow  solution  in  water,  and  a  scarlet-red  with 
sulphuric  acid. 

Literature,— J).  R.  P.  48465  ;  F.  P.  192628 ; 
A.  P.  398990. 

Erioehrome  Phosphlne  R  (G.) ;  Nitrosulpho- 
benzeneazosalicylic  acid 

NO,-0eH,(SO,H)N,C.H,(CO,H)OH 

Prepared  by  the  action  of  diazotised  p-nitro- 
aniune-o-su^honic  acid  on  sallcyUc  acid. 
Ydlowish-orange  aqueous  solution  bcNComes  pale 
orange  with  hydrochloric  acid,  and  blue-red  with 
sodium  hydroxide.  Solution  in  sulphuric  acid 
is  ydlowish-orange  giving  a  pale-yeliow  precipi- 
tate on  dilution. 

LitertUure.—D.  R.  P.  226242. 

2.  DisuLFHONio  Acids. 

Chrome  Brown  RR  (G.);  Disulphophenol- 
azopyrogallol 

OHC.H,(SO,H),N,C,H,(OH), 

Prepared  by  the  action  of  diazotised  p-amino- 
phenol-2 : 6-diBulphonio  acid  on  pyrogaUol. 
Solution  in  water  is  yeUow,  and  in  sulphuric 
acid  brown. 

Literature.— 1&.  P.  11902  of  1893  ;  D.  R.  P. 
81109  ;  F.  P.  230937  ;  A.  P.  548460. 

Orange  G  (A.)  (M.)  (B.)  (P.)  (0.  J.)  (T.  M.) 
(Sch.)  (K.)  (0.)  (Central  Dyestuff  and  Chemical 
Co.);  Orange  GG  (C.)  (B.  K.)  (D.);  Orange  GG  In 
Cr^tals  (Sch.);  Fast  Light  Orange  G  (By.); 
Benzeneazo-iS-naphtholdisulphonic  add 

C,H8-N,-CioH,(SO,H),-OH(j3) 

Produced  bv  the  action  of  diazobenzene  chloride 
on  iS-naphthol-6 : 8-di8ulphonic  acid  (G-salt)  in 
alkaline  solution.  Solution  not  precipitated  by 
alkali;  dissolves  in  sulphuric  acia  with  an 
orange  colour,  undeigoing  no  change  on  dilution. 

Literature,— E.  P.  1715  of  1878 ;  D.  R.  P. 
3229;  F.  P.  124811 ;  A.  P.  251162. 

Crystal  Seariet  6  R  (C.)  (M.)  (By.)  (B.  K.) ; 
Crystal  Poneeau  (A.)  (K.)  (B.)  (D.)  (L.)  (P.) ;  Pon- 
ceau 6  R  tT.M.) ;  a-Naphthaleneazo-jS-naphthol- 
6 : 8-diBulphonio  acid  (G-add).  Produced  by 
the  action  of  diazotised  a-naphthylamine  upon 
)3-naphthol-6 : 8-diBulphonio  acid  in  alkaline 
solution. 

Literature,— E.  P.  816  of  1884;  D.  R.  P. 
36491  ;  A.  P.  332528. 

Ponceau  2  G  (B.)  (M.)  (B.  K.) ;  BriUlant 
Poneeau  GG  (C);  Orange  R  (H.).  Isomeric 
with  Orange  G.  Prepared  by  the  action  of 
diazobenzene  chloride  upon  /8-naphthol-3 : 6- 
disulphonic  acid  (R-salt).  Properties  similar  to 
those  of  the  preceding  compound ;  colour 
slightly  redder  in  shade. 

Literature  as  for  Oranse  G. 

Acoeoralllne  L  (D.) ;  Azogrenadlne  L  (By.) ; 
p-Acetylaminobenzeneazo-)3-naphthol-3 : 6-di8ul- 
phonic  acid 

CH,CONHCeH4N,CioH4(SO,H),OH 

Prepared  b^  the  action  of  diazotised  aoetvl-}»- 
phenylenediamine     on     )3-naphthol-3 : 6-di8i&- 


AZO-  COLOURING  MATTERS. 


467 


phonic  acid  (R-salt).  Solution  in  water  is 
orange-red,  ana  in  sulphuric  acid  yellowish-red. 

Literalvre.'-Nietaiki,  Ber.  1884,  17,  344. 

Add  Alizarine  Red  B  (M.) ;  Pilatlne  Chrome 
Red  B  (B.) ;  Garboxybenzeneazo-iS-naphthol- 
3 : 6-disulphonio  acid 

COtH-C,H4N,C,oH4(SO,H),OH 

Prepared  from  diazotised  anthranilio  acid  and 
R-salt.  It  gives  a  yellowish-red  aqueous  solu- 
tion, and  a  red  solution  in  sulphuric  acid.  In 
the  form  of  a  lake  it  is  known  as  Pigment 
Beftrlet  8  B  (M.). 

Literature,^E,  P.  23830  of  1002 ;  D.  R.  P. 
141267  ;  P.  P.  328128 ;  A.  P.  767109. 

PolieeMi  R,  2  R,  6  and  GR  ^  (A.)  (B.)  (M.). 
(By.)  (B.  K.)  (0.)  (P.)  (L.)  (K.  S.)  (T.  M.)  (Lev.) 
(C.)  (C.  J.);  Brilliant  Poneean  R  (T.  M.); 
Scarlet  2  R  (H.)  (Calco  Chemical  Co.);  Xy- 
leneazo-)3-naphthol-3 :  B-diBulphonic  acid 

C,H,N,-CtA(SO,)H,-OH(iB) 

Produced  by  the  action  of  diazotised  xylidine 
(chiefly  meta-)  on  /3-naphthol-3  :  6-disulphonic 
acid  (R-salt).  Properties  similar  to  those  of 
Oranp;e  G.  Colour  a  distinct  scarlet ;  aqueous 
solution  not  precipitated  by  alkali;   an  amor- 

Shous  precipitate  by  calcium  or  barium  chloride, 
oluble  with  a  red  colour  in  sulphuric  acid, 
becoming  brown  and  precipitating  on  dilution. 

LUmaure,—lSi,  P.  1716  of  1878 ;  D.  B.  P. 
3229 ;  F.  P.  124811 ;  A.  P.  210233. 

Poneean  8  R  (A.)  (B.)  (M.)  (C.  J.)  (K.) 
TBy.)  (L.)  (0.) ;  Poneean  4  R*  (A.) ;  Poneean 
8  R  66  (Soh.) ;  Cumeneazo-8-naphthol-3  :  6- 
diBulphonio  acid 

C.Hu-N,-C,oH.(SO,H),OH(« 

Produced  by  the  action  of  diazocumene  chloride 
(from  4^-cumidine)  on  R-salt.  Properties  as 
above ;  colour  of  a  redder  shade  than  the  last. 

Literature, — See  above,  and  A.  P.  261163. 

Bordeaux  B  (H.)  (A.)  (M.)  (B.  K.)  (Calco 
Chemical  Co.) ;  Fast  Red  B  (B.)  (B.  K.)  (L.) ; 
rui  Red  P  extra  (By.) ;  Bordeaux  BL  (C.) ; 
Bordeaux  R  extra  (M.);  Bordeaux  G  (D.); 
Bordeaux  R  (T.  M.) ;  Ceraiine  (P.) ;  Cerasine  R 
(D.  H.) ;  Arehelline  2  B  (Lev.) ;  Am  Bordeaux 
(Sch.) ;  a-Naphthaleneazo-d-naphthol-3  :  6-di- 
sulphonic  acid 

CioH,N,C,oH4(80,H),OH 

Prepared  from  diazotised  a-naphthylamine  and 
R-salt.  Solution  in  water  is  magenta-red,  and 
in  sulphuric  acid  blue,  becoming  magenta-red 
on  dilution. 

Literaiure.—E.  P.  1716  of  1878 ;  D.  R.  P. 
3229 ;  F.  P.  124811 ;  A.  P.  261164. 

Coeeinine  B,  C  (M.) 

CH,0'C,H,(CH,)N,CioH4(SO,H),OH 

Prepared  from  diazotiBed3-amino-4-oresol  methyl 
ether  and  R-salt.  Gives  a  cherry-red  solution 
in  water  or  sulphuric  acid. 

Xttero/ure.— E.  P.  4914  of  1878 ;  D.  R.  P. 
7217;  P.P.  124811. 

SorUne  Red  (B.);  Axogrenadine  8  (By.); 
Lanatnehsine  (various  marks)  (C);   Azo  Aeid 

>  Q  OR  and  BriWant  Ponotau  G  (C)  are  made  from 
crude  xylidine  and  cnide  &-aalt,  R  from  crude  xylidioe 
and  S  R  from  m-zylldlne  and  pure  R-salt. 

'  3  R  is  made  from  crude  cumldioe  and  4  R  fiom  pure 
^•camldlne. 


Red  B  (M.) ;  Wool  Red  SB  (0.) ;  p-Aoetylamino- 
benzeneazo-a-naphthol-3  :  6-disulphonic  acid 

CH,-CONHC4H4N,C,oH4(SO,H),OH 
Prepared  b^  the  action  of  diazotised  tuoetyhp- 
phenylenediamine  on  a-naphthol-3 : 6-disulphonio 
acid.    Aqueous  solution  is  currant-red,  and  in 
sulphuric  acid  fiery  red. 

LUer€Uure.—Chem,  Zeit.  1900,  24,  493; 
Zeitsch.  Farben.  Ind.  1902,  26,  223. 

Palatine  Searlet  A  (B.) ;  Coehineal  Seariet  PS 
(By.) ;  Nassoira  Searlet  0  (M.) ;  Brilliant  Wool 
Searlet  (K.) ;  BrilUant  Coehineal  2  R,  4  R  (C.) ; 
m-Xyleneazo-a-naphthol-3 : 6-disulphonic  acid 
C|,H,'Na*CioH4(SO,H),-OH.  Pr^i^ed  from 
diazotised  m-xylidine  and  a-naphthol-3 : 6- 
disulphonic  acid.  Solution  in  water  is  scarlet- 
red,  and  in  sulphuric  acid  bluish-red. 

Literature.—J}.  R.  P.  appl.  G  3636. 

XL  Carmoi'sine  6  B  (H.) ;  m-X^leneasodi- 
hydroimiaphthalene-3  :  6-disulphomc  acid 

C«H,N,C,oH,(SO,H),(OH),.  Prepared  by  the 
action  of  diazotised  m-zylidine  on  1  : 8-dihy- 
droxynaphthalene-3  :  6-disulphonio  acid  (chro- 
matrope  acid). 

Eoeamine  B,  G  (A.) ;  Methoxytolueneazo-a- 
naphthol-3 : 8-(lisulphonic  acid 

CH,OC,H,N,C,aH.(SO,H),OH 
Prepared     from     diazotised    m-amino-p-cresol 
metnyl  ether  and  a-naphthol-3  :  8-disulphonic 
acid.    Solution  in  water  is  bluish-red,  and  in 
sulphuric  acid  violet-blue. 

Literature. — Chem.  Ind.  1896,  19,  8. 

PaUtine  Red  A  (B.) ;  Naphthorubin  0  (M.) ; 
a-Naphthaleneazo-a-naphthol-3  :  6-disulphonic 
acid  CtoH7N,-CioH.(SO,H),'OH.  Prepared 
from  diazotised  a-naphthylamine  and  a-naph- 
thol-3 :  6-disulphonic  acid.  Bluish-red  solution 
in  water,  and  blue  in  sulphuric  acid. 

Literature.— E.  P.  16716  of  1886 ;  D.  R.  P. 
38281. 

Dlreet  Rose  0  (K.  S.) ;  Erika  2  ON  (A.): 

CH,C,H,<^^C.H,N,C,oH,(SO,H),OH 

Prepared  from  diazotised  dehvdrothio-p-tolui- 
dine  and  a-naphthol-3 :  8-disulphonio  acid  (f  • 
acid).  Cherry-red  aqueous  solution  gives  a 
scarlet-red  precipitate  with  hydrochloric  acid, 
and  a  bluish-red  one  with  sodium  hydroxide. 
Solution  in  sulphuric  acid  is  dark-bluish  red, 
giving  a  scarlet-red  precipitate  on  dilution. 

Geranine  2  B,  G  (Bv.) ;  Brilliant  Geranine 
B,  2  BN,  8  B  (By.).  These  dyes  are  prepared 
from  the  same  diazo-  compound  as  the  preoeding, 
combined  with  a-naphthol-4  :  8-disulphonic 
acid  (2  B),  a-naphthol-3-sulphonio  acid  (G), 
or  1 :  8-dihydroz3maphthalene-4-sulphonic  add 
(Brilliant  Geranine).  The  aoueous  solution  is 
red,  and  that  in  sulphuric  acid  is  violet-red  (2  B 
and  G)  or  blue  (Brilliant  CJeranine). 

Literature.— D.  R.  P.  73261,  73340. 

Erika  B  extra,  BN  (Lev.)  (L.)  (A.) ;  Methyl- 
benzenylaminothioxylenolazo-a-naphthol-3  :  8- 
disulphonic  acid 

(CH,),C.h/^\cC,H,N,CioH,(SO,H), 


'\n^^  I 


CH, 


i 


H 


Prepared  from  diazotised  dehydrothio-m- xyli- 
dine and  a-naphthol-3 : 8-disulphonio  acid. 
Solution  in  water  or  sulphuric  acid  is  red. 


408 


AZO.  COLOURINa  MATTERS. 


lAteraiure,—^  P.  17333  of  18S8 ;   D.  R.  P., 
63961 ;  F.  P.  194406  ;  A.  P.  418657  ;  Anschutz 
and  Schultz,  Ber.  1889,  22,  683. 

Erika  0  extra,  6N  (A.)  (Lev.) ;  Erika  4  GN 
(A.).  Is  isomeric  with  the  preceding,  being 
prepared  from  ^-naphthol-6  :  8-di8alphonic  acid 
(G-acid),  and  has  similar  reactions. 

Literature.— Ber.  1889,  22,  685. 

Azoeoehlneal  (By.) ;  Anisoleazo-a-naphthol- 
4 :  S-disulphonic  acid 

CH,OCA-N,C,oH4(SO,H),-OH 

Prepared  from  diazotised  o-anisidine  and  a- 
napnthol-4 : 8-disulphonio  acid.  Solution  In 
water  and  sulphuric  acid  is  red. 

Literature.— K  P.  16776  and  15781  of  1885 ; 
D.  R.  P.  40571 ;  F.  P.  173083,  173084. 

Chromotrope  2  R  (M.) ;  XL  Carmoisine  B 
(H.) ;  Benzeneazo-  I  :  8-dihydroxynaphthalene- 
3 :  6-di8ulphonio  acid 

.  C.H.N,CioH,(SO,H),(OH), 

Produced  from  diazotised  aniline  and  1 : 8- 
dihydroxynaphthalene  -3:6-  disulphonic  acid. 
Gives  in  water  a  magenta-red,  and  in  sulphuric 
acid  a  ruby-red  solution. 

Literature.—^.  P.  9268  of  1890 ;  D.  R  P. 
69096  ;  F.  P.  206439,  212607  ;  A.  P.  458283. 

Chromotrope  2  B  (M.) ;  p-Nitrobenzeneazo- 
1:8-  dihydroxynaphthalene  -3:6-  disulphonic 
acid  NO,C.H,N,C,oH,(SO,H),(OH),.  Pre- 
pared by  the  action  of  diazotised  }>-nitroani- 
tine  on  1  :  8-dihydroxynaphthalene-3  :  6-di8ul- 
phonic  acid.  Solution  in  water  is  yellowish-red, 
and  in  sulphuric  acid  dark-violet. 

Literature. — ^As  under  Chromotrope  2R. 

Victoria  Violet  4  BS  (M.)  (By.) ;  Domingo 
Violet  A  (L.) ;  Ethyl  Acid  Violet  S  4  B  (B.) ; 
Axo  Wool  Blue  (C.) ;  ji-Aminobenzeneazo-l :  8- 
dihydroxynaphthalene  -3:6-  disulphonic  acid 
NHg-C. H4N,-C,o H, (SO,H), (OH),.  Prepared 
by  the  alkaline  reduction  of  chromotrope  2  B 
or  by  eliminating  the  acetyl-  group  from  cnromo- 
trope  6  B  {see  l)elow).  It  gives  a  dark-violet 
solution  in  water,  and  a  bluish-red  in  sulphuric 
acid.  Similar  colouring  matters  are  Victoria 
Violet  8  BS  (M.),  Victoria  Violet  5  B  (By.),  and 
Victoria  Violet  L  (I.). 

Literature.— E.  P.  8270  of  1892 ;  D.  R.  P. 
70885,  73321 ;  F.  P.  221363,  226690. 

Chromotrope  6  B  (M.) ;  XL  Fuchsine  6  B 
(H.);  Fttt  Add  Red  EBB  (L.) ;  p-Acetylamino- 
benzeneazo-1  :  8-dihydroxynaphthalene-3  :  6- 
disulphonic  acid 

CH,-CONHCeH4N,-CioH,(SO,H),(OH), 

Prepared  by  the  action  of  diazotised  acetyl-^- 
phenylenediamine  on  1 :  8-dihvdroxynaphthal- 
ene-3 : 6-disulphonio  acid.  Solution  in  water 
is  violet-red,  and  in  sulphuric  acid  ruby-red. 

Literature.— D.  R.  P.  75738. 

Chromotrope  10  B  (M.) ;  Naphthaleneazo 
1 :  8-dihydroxynaphthalene-3 : 6  disulphonic  acid 

C,.H,-N.C,.H,(SO,H),(OH), 

Prepared  from  diazotised  a-naphthylamine  and 
the  above  acid.  Violet  solution  in  water,  and 
greenish-blue  in  sulphuric  acid. 

Literature. — ^As  under  Chromotrope  2  R. 

Chromazone  Red  A  (G.) ;  Benzaldehydeazo- 
1  :  8-dihydroxyi\aphtha)ene-3  :  6-disulphonic 
acid    CHOCcH4N,C,oH,(SO,H),(OH),.    Pro- 


duced from  diazotised  7)-aminobenzaldehyde 
and  1  :  8-dihydroxynaphthalene-3 : 6-disnlphonic 
acid.  Solution  in  water  is  red,  and  in  sulphuric 
acid  blue. 

Literature.— E.  P.  13744  of  1896 ;  D.  R.  P. 
85233;  F.  P.  248517. 

Chromazone  Blue  R  (G.) ;  Phenylethylhy- 
drazone  of  the  preceding  colouring  matter 

C,H5(CjH4)N  N :  CHOgH4N,CioH,(80,H),(OH), 

Prepared  either  by  condensing  chromazone  red 
with  (M-phenylethylhydrazine  or  by  the  action 
of  diazotised  p-aminobenzylidenephenylethylhy- 
drazone  on  1 :  8-dihydroxy-3  :  6-disulphonic  acid. 
Solution  in  water  is  blue- violet,  and  in  sulphnrio 
acid  blue-red. 

Literature  as  above. 

Diamine  Rose  (various  marks)  ;  Dianfl 
Rose  BD.(M.);  Benzenylaminothiophcnolazo- 
chloronaphtholdisulphonic  acid 

CH,CaH,<f®';>CCeH4N,*CioH,a(SO,H),OH 

Prepared  from  diazotised  dehydrothio-p-tolui- 
dine  and  8-chloro-a-naphthol-3  :  6-disulphonic 
acid.  Magenta-red  solution  in  water,  and 
reddish-violet  in  sulphuric  acid. 

Literature.— E.  P.  1920  and  9441  of  1894; 
D.  R.  P.  79056,  82285,  96768,  99227;  F.  P. 
235271 ;  A.  P.  535037. 

Fast  Add  Fachsine  B  (By.);  Fast  Add 
Fuchsine  G  (B.K.) ;  Benzeneazo-1  8:  -amino- 
naphthol  3  :  6-disulphonic  acid 

C,H,N,*CioH,(SO,H),(OH)-NH, 

Prepared  from  diazotised  aniline  and  1 : 8- 
aminonaphthol-3  :  6-disulphonic  acid  (H-acid) 
in  alkalme  solution.  Solution  in  water  or 
sulphuric  acid  is  magenta-red. 

Literature.— E.  P.  13343  of  1890 ;  D.  R.  P. 
62368,  70031 ;  F.  P.  210033. 

Tolane  Red  B  (K.) ;  Benzeneazo-1 :  8-amino- 
naphthol-4  *  6-disulphonic  acid.  Isomeric  with 
the  preceding.  Prepared  from  diazotised  aniline 
and  1  :  8-aminonaphthol-4  :  6-di8ulphonic  acid 
(K-acid).  Solution  in  water  or  sulphuric  acid 
is  magenta-red. 

Literature.— E.  P.  615  of  1894;  D.  R.  P. 
99164  ;  A.  P.  563383. 

Amidonaphthol  Red  Q  (M.) ;  Brilliant  Add 
Carmine  2  G  (O.) ;  Azo  Phloxine  2  G  (By.) ; 
Benzeneazo-1  :  8-acetylaminonaphthol-3  :  6-di- 
sulphonic acid 

C,H,N,CioH,(S03H),(OH)NH-COCH, 

Prepared  from  diazotised  aniline  and  acetyl 
H-acid  in  alkaline  solution.  Scarlet-red  solution 
in  water,  and  red  solution  in  sulphuric  acid. 

Literature.— E.  P.  26457  of  1905 ;  D.  R.  P. 
180089  ;  F.  P.  348426. 

Amido  Naphthol  Red  6  B  (M.) ;  Brilliant 
Acid  Carmine  6  B  (O.).  Prepared  as  the  pre- 
ceding, but  p-aminoacetanilide  is  used  instead 
of  aniline.  The  solution  in  water  or  sulphuric 
acid  is  red. 

Palatine  Chrome  Green  G  (B.);  Chrome 
Fast  Green  G  (1.);  4-Nitro-2-aminophenol  U 
diazotised  and  combined  with  H-acid.  It  gives 
a  dark  reddish- violet  solution  in  water,  and  a 
reddish- violet  in  sulphuric  acid. 

Fast  Sulphone  Violet  5  BS  (K.  S.)  is  prepared 
by  combining  a  diazo-  compound  with   1  : 8- 


AZO-  COLOURING  BiATTERS. 


460 


aminonaphthol-3  :  6-  or  -4  :  G-disulphonic  acid 
in  alkaline  solution,  and  treating  the  product 
with  p-toluenesulphonyl  chloride,  whereby  the 
amino-  group  is  transformed  into  the  p-toluene- 
Bulphonylamino-  group.  Other  dyestuffs  of  the 
same  kind  are  BnUiant  Sulphone  Red  B  (K.  S.) 
and  Fast  Sulphone  Violet  4  R  (K  8.). 

Lit&ralure.—E.  P.  22886  of  1899 ;  D.  R.  P. 
120081 ;  F.  P.  294325;  A.  P.  6409b9. 

Azo  Arebll  R.  (A.);  Benzeneazo-2-amino- 
8-naphthol-3 :  d-disulphonio  acid  (2  R-  acid). 
Isomeric  with  fast  acid  fuchsine  B  (By.). 
Prepared  from  diazotised  aniline  and  2  R-acid. 
Solution  in  water  or  sulphuric  acid  is  yellowish- 
red. 

LiUrature,—D,  R.  P.  appl.  A  3710. 

Aiorublne  (Wiescher  &  Co.)  (0.)  (Lev.) 
(Central  Dyestuff  and  Chemical  Co.) ;  AzoinUne 
S(A.)  (Sch.) ;  Azonibine G  (T.  M.) ;  Azonibine  A 
(0.) ;  Azo  Acid  Rubine  (C.  J.)  (D.) ;  Azo  Acid 
Rublne  R  (K.);  Nacarat  (P.);  Fast  Red  C 
(B.)  (B.  K.) ;  Cannoi'sine  (K.  S.) ;  Carmoisine  B 
(By.);  Caimoisine  S  (H.);  Man  Red  G  (B.) ; 
Mllant  Crimson  (CI.  Co.) ;  Brilliant  Cannoi'sine 
0  (M.) ;  Sulpho-a-naphthaleneazo-a-naphthol- 
sulphonic  acid 

HSO,C|oH,-N,-C,oH5(SO,H)OH 

Prepared  by  the  action  of  diazotised  naphthionic 
acici  on  a-naphthol-4-suIphonio  acid  in  presence 
of  alkali.  Solution  gives  a  red  crystalune  pre- 
cipitate with  calcium  chloride ;  substance  dis- 
solves in  sulphuric  acid  with  a  bluish-violet 
colour,  beconung  red  on  dilution.  When  used 
for  aftier-chrominff  on  wool  the  dyestuff  is  known 
as  Azoclirome  Blue  R  (K.) ;  Chrome  Blue  R 
(B.);  Chromotrope  FB  (M.);  Omega  Chrome 
Blue  A  (K.  S.). 

Literature,— E,  P.  2237  and  4237  of  1883 ; 
D.  R.  P.  26012,  66838,  67240. 

Fast  Red  VR  (Bv);  isomeric  with  the 
preceding.  Prepared  from  diazotised  naphthi- 
onic acid  and  a-naphthol-5-8ulphonio  acid. 
Aqueous  solution  is  oluish-red  and  gives  a 
reddish-brown  precipitate  with  hydrochloric 
acid.  Substance  dissolves  in  sulphuric  acid 
with  reddj/sh-blue  colour.  When  used  for  after- 
chroming  on  wool  the  dyestuff  is  known  as 
Azoclirome  Blue  B  (K.) ;  Chromotrope  F  4  B 
(M.).  Diamona  Blue  8  B  (By.)  also  belongs  to 
this  class. 

Fftst  Red  (B.)(IC)(By.)(B.K.)  (T.  M.)  (D.) 
(O.);  Fast  Red  S(M.)(D.H.);  Naphthol  Red  EB 
(C);  Mapbthol  Red  GR  (B.) ;  Acid  Cannoisine  B 
(B.  K.);  Fast  Red  (Lev.)  (A.)  (C.  J.)  (P.);  Sulpho- 
a  •  naphthaleneazo  -  /3  -  naphtholsulphonic  acid 
HSO,CioH,-N,-CioH4(SO,H)-OH.  Isomeric  with 
the  precedinff ;  prepared  from  diazotised 
naphthionio  acid  and i9-naphthol-6-8ulphonio  acid. 
Aqueous  solution  claret-red;  not  precipitated 
b^  acids,  dissolves  in  sulphuric  acid  with  a 
violet  oolonr,  becoming  red  on  dilution. 

Ltterature.—E.  P.  786  of  1878;  D.  R.  P. 
5411 ;  F.  P.  123148 ;  A.  P.  204799. 

Croeeifne  Scarlet  8  BX  (By.)  (K.) ;  Coccine  2  B 
(A.) ;  Scarlet  000  (H.) ;  Acidol  Coccine  2  B 
(T.  M.).  Isomeric  with  the  last;  prepared 
from  diazotised  naphthionic  acid  and  /3-naphthol- 
8-8uli^onio  acid.  Hot  solution  (concentrated) 
gives  a  orystalline  magnesium  salt  on  adding 
magnesiam    sulphate  and    allowing    to    cool; 


solution  in  sulphuric  acid  reddish- violet  becoming 
yellowish-red  on  dilution. 

Literature,—^.  P.  2031  of  1881 ;  D.  R.  P. 
20402  ;  A.  P.  256376. 

Double  Scarlet  Extra  S  (A.)  (Lev.) ;  Double 
Brilliant  Scarlet  3  R  (By.);  Double  Brilliant 
Scarlet  S  (K.) ;  Brilliant  Ponceau  4  R  (By.) ; 
Scarlet  PR  (P.) ;  Scarlet  2  R  extra  cone  (T.  M.). 
Isomeric  with  the  last ;  prepared  from  diazotised 
jS-naphthylamine-6-sulphomo  acid  and  a-naph- 
thol-4-suiphonic  acid 

HSOaCioH,N,CioHj(SO,H)OH 

Aqueous  solution  gives  yellowish-brown  pre- 
cipitate with  dilute  acids.  Dissolves  in  sul- 
phuric acid  with  a  red  colour,  becoming  yellower 
on  dilution. 

Xrtera/ur«.— E.  P.  3724  of  1882 ;  D.  R.  P. 
22547  ;  F.  P.  160603  ;  A.  P.  332829. 

Azotuchsine  G  (By.) ;  Fast  Fuchsine  G  (Sch.) ; 
p  •  Sulphobenzeneazodihydrozynaphthalene  -  4  - 
sulphonio  acid 

HSO,C.H4N,CioH4(OH),SO,H 

Prepared  from  diazotised  snlphfimilic  acid  and 
1 : 8-dihydroxynaphthalene-4-sulphonio  acid.  So- 
lution in  water  is  bluish-red,  and  in  sulphuric 
acid  violet.  Analogous  colours  are  Azofuchsine 
S,  6  B,  and  GN  extra  (By.). 

Literature.— E.  P.  18517  of  1889 ;  D.  R.  P. 
54116  ;  F.  P.  203744  ;  A.  P.  466841,  468142. 

CrumpsaU  Yellow  (Lev.) ;  Disulphonaphtha- 
leneazosidicylic  acid 

CioH,(SO,H),N,C,H,(OH)CO,H 

Produced  by  the  action  of  diazotised  ^-naph- 
thylamine-6  :  8-di8ulphonic  acid  on  salicylic  acid. 
Solution  in  water  is  yellow,  and  in  sulphuric 
ax)id,  orange-red. 

Literature.— E.  P.  12145  of  1894 ;  D.  R.  P. 
87483. 

Lanaeyl  Blue  BB  (C);  Disulphohydroxy- 
naphthaleneazoaminonaphthol 

CioH4(SO,H),(OH)N,OioH,(OH)NH, 

Prepared  from  diazotised  1  :  8-aminonaphthol- 
3  :  6-disulphonic  acid  (H-acid)  and  1 :  5-amino- 
naphthol  in  acetic  acid  solution  (the  azo-  group 
attacks  the  ortho-  position  relative  to  the 
hydroxy-  group).  Solution  in  water  is  reddish 
or  bluish-violet,  and  in  sulphuric  acid  blue. 
To  this  group  belong  also  Lanaeyl  Blue  R  and 
Lanaeyl  Navy  Blue  B,  2  B,  and  8  B  (C). 

Literature.— E.  P.  24134  of  1896 ;  D.  R.  P. 
95190 ;  F.  P.  260848. 

Rosophenine  10  B  (CI.  Co.);  Rosophenine 
Pink  (CI.  Co.) ;  Direct  Scarlet  B  (K.) ;  Thiazine 
Red  R  (B.) ;  Benzoin  Fast  Red  AE  (B.  K.) ; 
Sulphobenzenylaminothiocresolazo-  a  -  naphthol- 
4-sulphonic  acid 

C.H,<C  \c*C*H«N,CioH,OH 

CH,  SO»H      SO,H 

Prepared  from  diazotised  dehydrothio-p-tolui- 
dinesulphonic  acid  and  a-naphthol-4-sulphonio 
acid.  Solution  in  water  is  crimson-red,  and  in 
sulphuric  acid  violet-red. 

The  corresponding  colour  from  diazotised 

primuline  is  called  Rosophenine  SG  (CI.  Co.) ; 

(D.  R.  P.  48465 ;  F.  P.  192628,  196988 ;  A.  P. 

398990). 

I       TMazine  Red  G  (B.).    Prepared  from  diazo- 


470 


AZO-  COLOURING  MATTERS. 


tJBed  primuline  (sulphonic  acid)  and  ^-naphthol- 
6-sulphonic  acid.  Orange-red  aqueoua  solution 
gives  an  orange-red  precipitate  with  hydrochlorio 
acid,  and  becomes  oark  with  sodium  nydrozide. 
Solution  in  sulphuric  acid  is  blood-red,  giving 
an  orange  precipitate  on  dilution. 

The  corresponding  colour  from  diazotised 
dehydrothio-p-toluidinesulphonic  acid  is  Clayton 
CI0&  Searlet  (CI.  Co.) ;  ntan  Pink  8  B  (H.)  ; 
ThUzlne  Red  GN  (B.). 

References  as  tor  roeophenin^  SG. 

3.  TaisuLPHOKio  Agios. 

Am  Red  A  (C.) ;  Sulpho-a-naphthaleneazo- 
a-naphthol-3 : 6-disttlphonic  acid 

HSO,-CioH,-N,-CioH4(80,H),OH 

Ftepaxed  by  the  action  of  diazotised  naphthionic 
acid  on  a-naphthol-3  :  6-disulphonic  acid.  Aque- 
ous solution  red.  Solution  m  sulphuric  acid  is 
blue,  becoming  violet  and  then  rea  on  dilution. 
New  Coodne  (A.)  (M.);  Brilliant  Searlet 
(Lev.)  (C.) ;  Croeei'ne  Searlet  4  BX  (K.) ;  Victoria 
Searlet  4  R  (T.  M.) ;  Special  Ponceau  (P.) ;  Co- 
chineal Red  A  (B.);  Brilliant  Ponceau  4  R 
(By.)  (C.) ;  Brilliant  Ponceau  5  R  (By.)  (D.) ; 
Ponceau  4  R  (B.  K.) ;  Brilliant  Scarlet  i  (Sch.) ; 
Scariet  5  0  (H.) ;  Scariet  N  (Farbwerk  Ammers- 
foort) ;  Sul^ho-g-naphthaleneazo-jS-naphthol- 
6 : 8-disulphomc  acid 

HSO,CioH.-N,CioH4(SO,H),OH  ' 

Prepazed  by  the  action  of  diazotised  naphthionic 
acid  on  /St-naphthol-6 : 8-disulphonic  acid  (G- 
salt).  Aqueous  solution  red,  not  precipitated 
by  acids.  Dissolves  in  sulphuric  acid  with  a 
rod  colour,  becoming  yellowish-red  on  dilution. 

Literaturc—E.  P.  816  of  1884;  D.  R.  P. 
3229,  36491 ;  F.  P.  124811 :  A.  P.  314938. 

Fast  Red  D  (B.)  (0.) ;  Azo  Add  Rubinc  2  B 
(D.)  (B.  K.)  (C.  J.);  Cloth  Red  (T.  M.);  Bordeaux 
S  (A.)  (Lev.) ;  Amaranth  (M.)  (C.)  (B.  K.)  (P.) 
(L)  (D.  H.)  (T.  M.)  (Lev.)  (Central  Dyestuff  and 
Chemical  Ck>.)  (Ault  and  Wiborg  Co.) ;  Naphthol 
RcdO(Bi.);  Naphthol  Red  S(B.)(B.K.):  Naphthol 
Rod  C  (C);  Naphthylaminc  Red  G  (By.); 
Fast  Red  (C.  J.) ;  Fast  Red  NS  (By.) ;  Bordeaux 
DH  (D.  H.);  Victoria  Rubinc  0  (M.)  (B.K.); 
Axo  Rubinc  S  (K.  S.) ;  Amaranth  107  (Sch.) ; 
Acid  Crimson  (H.);  Wool  Red  (Sch.);  Wool 
Red  extra  (K.) ;  Aio  Red  N  extra  (L.).  Isomeric 
with  the  preceding.  Prepsxed  from  diazotised 
naphthiomc  acid  and  B-salt. 

Literatwrc—D,  B.  P.  3229. 

Chromotrope  8  B  (M.) ;  p-Sulphonaphthalene- 
azodihydroxynaphthalene-3 : 6-aisulphonic  acid 

HSO,CioH,N,CioH,(SO,H),(OH), 

Prm^Mtred  by  the  action  of  diazotised  naphthionic 
acid  on  1 :  8-dihydrozynaphthalene-3  :  6-disul- 
phonic acid.  Solution  in  water  is  violet-red,  and 
m  sulphuric  acid  indigo-blue.  In  addition  to 
this  and  the  other  *  chromotrope '  colours 
mentioned  above,  the  marks  S  and  7  B  also 
appear  on  the  market,  but  their  constitution 
has  not  yet  been  published. 

i/»tera/ttr«.— E.  P.  9258  of  1890 ;  D.  R.  P. 
69096;  F.  P.  212607 ;  A.  P.  468283. 

4.  TSTBASULFHONIC  AdDS. 

Ponceau  6  R  (M)  (B.) ;  p-Sulphonaphtha- 
leneazo-iS-naphtholtrisulphonio  acid 


HSO,CioH,-N,CioH,(SO,H).OH 

Prepared  by  the  action  of  diazotised  naphthionic 
acid  on  iS-naphthol-3  :  6 :  8-trisulphonic  acid. 
Solution  in  water  is  magenta-red,  and  in  sul- 
phuric acid  violet. 

LUerature.--E.  P.  2644  of  1882 ;  D.  R.  P. 
22038  ;  F.  P.  149249  ;  A.  P.  268606. 

HcUopurpurinc  4  BL  (Bv.) ;  IHsulphonaph- 
thaleneazo-tt-naphthol-3 :  6-disiilphonic  acid 

OioH4(SO,H),N,-CioH4(SO,H),-OH 

Prepared  from  diazotised  /3-naphthvlamine- 
3  :  o-disulphonic  acid  and  a-naphthol-3  :  6- 
disulphomc  acid.  Used  exclusively  in  tlie 
manufacture  of  lakes. 

i^tteni^ttre.— Farber-Zeit.  1904,  16,  96. 

HcUopurpurinc  7  BL  (Bv.).  Isomeric  with 
the  preceding.  Prepared  by  the  action  of 
diazotised  jS-naphthylamine-l :  6-disulphonic 
acid  on  i3-naphthol-3 : 6-diBulphonic  acid  (R- 
salt).    Used  only  for  lakes. 

Literature  as  above. 

6.   PENTASULFHOinc  AciBS. 

HcUopurpurinc  GL  (By.) ;  Disulphonaphtha- 
leneazo-iS-naphthol-3  :  6 :  8-tri8ulphonic  acid 

C,oH,(SO,H),-N,'CioH,(SO,H),OH 

Prepared  from  diazotised  /3-naphthylamine- 
3  :  6-di8ulphonic  acid  and  i3-naphthol-3  :  6 :  8- 
trisulphonic  acid. 

Use  and  literature  as  above. 

E.  CarboxyUc  Acids  of  Hydroxyazo-  Compounds.^ 

AUzarinc  TcUow  GO  (M.)  (L);  Chrome 
YcUow  R  (P.) ;  AUzarinc  YcUow  G,  8G  (Lev.) ; 
AUzarinc  TcUow  8  G  (By.);  Mordant  YcUow 
2GT(B.);  Anthracene  YcUow  GG  (C.) ;  AUza- 
rinc YcUow  G  (K.  S.) ;  m-NitrobenzeneazosaU- 
cyUc  acid 

N0,-C,H4N,C,H,(C0,H)0H 

Prepared  from  diazotised  m-nitroaniline  and 
salicyUc  acid.  The  commercial  product  (the 
free  acid)  is  usuaUy  a  yeUow  paste,  insoluble 
in  water,  and  giving  an  orange  solution  with 
sulphuric  acid.  The  sodium  sut  is  put  on  the 
market  in  the  dry  state  as  Alizarine  YcUow  GGW 
(M.)  (Ault  and  Wiborg  Co.). 

Literature,— E.  P.  17683  of  1887 ;  D.  R.  P. 
44170 ;  F.  P.  187821 ;  A.  P.  424019. 

AUzarinc  YcUow  R  (M.)  (C.  R.)  (Bv.); 
AUzarinc  Grange  R,  2  R  (Lev.) ;  Mordant  YcUow 
3  R  (B.);  Mordant  YcUow  PN  (Farbwerk 
Ammersfoort) ;  Orange  R  (K.  S.);  Milling 
Orange  R  (L.);  Anthracene  YcUow  RN  (C); 
Mctachrome  Orange  R  (A.)  (Brotherton  &  Co.) ; 
Chromoxanthtaic  (K.  S.);  Terracotta  R  (G.); 
Chrome  Orange  (P.).  Isomeric  with  the  last. 
Prepared  from  diazotised  ;}-nitroaniline  and 
salicyUc  acid.  Comes  on  the  market  as  a 
brown  paste  insoluble  in  water  and  giving  an 
orsAge-yeUow  solution  with  sulphuric  acid. 
This  consists  of  the  free  acid ;  the  sodium  salt 
(soluble  in  water  with  an  orange  colour)  is 
called  AUzarinc  YcUow  RW  (M.)  (Harden, 
Orth,  and  Hastings  Corporation). 

Literature, — ^Afeldola,  Chem.  Soc.  Trans.  1886, 
47,  666;    BuU.  MuUiouse,  1892,  198;   J.  Soa 

^  CarboxyUc  acids  contalniog  also  lulphonic  add 
gzoups  are  described  under  the  oonespondiniB  sulphonlo 
or  disulphonio  adds. 


AZO-  COLOURING  MATTERS. 


471 


Ohem.  Ind.  1890,  9,  63 ;  1892,  11,  699 ;  J.  Soc. 
I>yei8,  1889,  5,  106;  £.  P.  13920  of  1888; 
F.  P.  193190 ;  A.  P.  431297. 

Chrome  Fast  Tallow  GO  (A.) ;  o-Anisoleazo- 
salioylio  acid  CH,OC.H4N,C.H,(00,H)OH. 
Prepared  from  diaEotued  o-aniaidme  and  sali- 
oylio  acid.  In  commerce  as  a  bright-yellow 
paste  or  a  yellow  powder.  Solution  in  hot  water 
IS  greenish-yellow,  and  in  sulphjxric  acid  yellow- 
ish-brown. 

Ltlrrodirf.— E.  P.  12221  of  1896;  D.  R.  P. 
84772. 

Aioalliailiio  Yellow  6  0  (D.  H.) ;  Alizarine 
Yellow  5  G  (M.) ;  Tartraehromine  GG  (I.) ; 
p-phenetoleazoealicylio  acid 

C,H50C,H4-N,C,H,(CO,H)OH 

Prepared  from  diazotised  p-phenetidine  and 
salicylic  acid.  Solution  in  water  la  yellowish- 
brown,  and  in  sulphuric  acid  brown-red. 

Diamond  Flavlne  G  (By.);  p-Hydroxydi- 
phenylazosalicylic  acid 

OH-Ci^,N,C,H,(CO,H)OH 

Prepared  by  boiling  the  intermediate  product 
from  tetrazotised  benzidine  and  one  molecule  of 
salicylic  acid.  In  commerce  as  a  yellowish- 
brown  paste  or  powder  which  dissolves  in  water 
only  alter  the  addition  of  sodium  acetate. 
Solution  in  sulphuric  acid  is  blood-red.  If  the 
intermediate  product  is  treated  with  sodium 
bisulphite,  the  product  is  known  as  Dutch  Yellow 
(Farbwerk  Ammersf oort) ;  Mordant  Ydlow  GRO 
(B.),  which  gives  a  yellow  solution  in  water,  and 
a  bordeaux-red  one  in  sulphuric  acid  (D.  R.  P. 
68963). 

Literature,— K  P.  11663  of  1891 ;  D.  R.  P. 
60373  ;  F.  P.  214766. 

Diamond  Yellow  G  (By.);  m-Carboxyben- 
zeneazosalicylic  acid 

C0,HC.H4N,C,H,|C0,H)0H 

Prepared  from  diazotised  fii-aminobenzoio  acid 
ana  salicylic  acid.  A  greyish-yellow  paste 
soluble  in  water  (with  addition  of  sodium 
acetate  or  carbonate)  with  a  yellow  colour. 
Gives  a  reddish-yellow  solution  with  sulphuric 
acid. 

LUerature.—E.  P.  8299  of  1889 ;  D.  R.  P. 
68271 ;  F.  P.  198621  (addition) ;  A.  P.  602368, 
602369. 

Lake  Red  D  (M.) ;  Carboxybenzeneazo-jS- 
naphthol  COjHC.H^N.CioH.OH.  Prepared 
from  diazotised  anthntnilic  acid  and  )3-naphthol. 
Orange-red  paste  used  for  lakes. 

literature,— E,  P.  22781  of  1906 ;  D.  R.  P. 
189023  ;  F.  P.  373116  ;  A.  P.  878964. 

BriUlant^Lake  Red  R  (M.);  Benzeneazo-2- 
hydroxy-3-naphthoic  acid 

C^,-N,-0,oH5(OH)-CO,H 

i^cepared  from  diazotised  aniline  and  iS-hydroxy- 
napnthoic  acid.    Used  for  making  lakes 
Literature.— Bet.  1893,  26,  2897. 

F.  Unclassified  Monoazo-  Colouring  Matters. 

Perl  Wool  Blue  B,  BG,  G  (C).  These 
oolooiing  matters  are  produced  by  the  action  of 
diazotised  nitroaminophenols  on  peri-  derivatives 
of  naphthalene. 


III.  DiSAzo-  Compounds.* 

A.  Primary  Dlsaso-  Colouring  Matters.* 
Leather  Brown  (0.) : 

NH,0eH4N,-C,H,(NHJ,N,0,H4NH, 

Prepared  by  combining  2  mols.  of  p-diazoacet- 
anifide  with  1  mol.  of  m-phenylenediamine, 
and  heating  the  product  with  strong  hydro- 
chloric acid.  Commercial  product  is  the  mono- 
hydrochloride  or  the  zinc  chloride  double  salt. 
The  brown  aqueous  solution  becomes  yellower 
on  adding  hydrochloric  acid,  and  sives  a  brown 
precipitate  with  sodium  hydroxide.  The  sub- 
stance gives  a  brown  solution  in  sulphuric  acid, 
which  Socomes  yeUowish-brown  on  dilution. 

Literature,— B,  P.  11218  of  1891 ;  D.  B.  P. 
57429;  A.*P.  462414. 

Terra  Cotta  F  (G.) ;  Clayton  Cotton  Brown 

(CI.  Co.) : 

P  •  •N,C.H,(NH,),N,CxoH,SO,H 

Prepared  by  combining  first  diazotised  naphthi- 
onic  acid  and  secondly  diazotised  j^rimuline 
with  m-phenylenediamine.  Solution  m  water 
is  brown,  giving  a  brown  precipitate  with  hydro- 
chloric acid.  Sulphuric  acid  dissolves  colour  to 
a  reddish-violet  solution,  giving  a  brown  pre- 
cipitate on  dilution. 

Literature,— E,  P.  1688  and  8215  of  1890 ; 
D.  R.  P.  appl.  Q.  5870 ;  F.  P.  203439 ;  A.  P. 
440288. 

Cotton  Orange  R  (B.) :       ' 

P « •N,C.(NH,),(S0,H),N,C,H4S0,H« 

Prepared  by  combining  first  diazotised  primuline 
ana  seconoly  diazotued  metanilic  acid  with 
m-phenylenediaminedisulphonic  acid.  The 
orange-red  aqueous  solution  gives  a  reddish 
precipitate  with  hydrochloric  acid.  Solution  in 
sulphuric  acid  is  bright  red,  precipitating  on 
dilution. 

Literature,— E,  P.  21753  of  1893 ;  D.  B.  P. 
76118 ;  F.  P.  231694  ;  A.  P.  524261. 

Anthracene  Acid  Brown  G  (C.)  (Harden, 
Orth,  and  Hastings  Corporation) : 

HSOaC,H4N,C.H,(CO,H)(OH)N,C,H4NO, 

Prepared  by  combining  diazotised  sulphanilic 
acid  (1  mol.)  and  mazotised  p-nitroaniline 
(1  mol.)  with  salicylic  acid  (1  mol.).  Aqueous 
solution  is  reddish-Drown,  and  that  in  sulphuric 
acid  is  bluish-green. 

Literature,— E.  P.  17590  of  1896 ;  D.  R.  P. 
95066 ;  F.  P.  258783. 

Resoreln  Brown  (A.)  (K.)  (H.)  (I.)  (B.  K.) 
(Sch.) :  ^ 

HSO,C.H4N,0,H,(OH),N,C,H, 

Diazoxylene  chloride  is  combined  with  resoroin 
yellow.  Aqueous  solution  gives  a  brown 
precipitate  with  acids.  Dissolves  in  sulphuric 
acid  with  a  brown  colour. 

Literature.— D.  R.  P.  18861 ;  A.  P.  269359. 

^Sm  also  DlSAZO-  IVD  TITBAXO-  OOLOUUHO 
MATTUtS. 

*  It  will  be  suffldent  to  give  the  chemical  formuln  of 
these  dlsaso-oompoonds  without  giving  tbelr  names  in 
fuU. 

*  Psreeidne  of  primuline  or  dehydrothlotoluldine 
refers  to  sulphonio  add. 

*  Acooralng  to  Heunuum  (Die  Anilinfarben  and  Ihre 
Fabrlkatlon)  the  formula  Is — 

PN,C,H(NH,XS0,H),NHN,C,H4S0,H 


472 


AZO-  COLOURING  MATTERS. 


Fast  Brown  6  (A.) ;  Add  Brown  (D.)  (P.) ; 
Aeid  Brown  6  (T.  M.)  (B.  IL): 

(HSO,C.H4-N,),CioH5-OH(a) 

Prepared  by  the  action  of  diazotised  sulphanilio 
aouf  (2  molB.)  on  a-naphthol  (1  mol.).  Aqueous 
solution  red-brown;  violet  precipitate  with 
dilute  acid.  Sulphuric  acid  solution  violet, 
becoming  yeUowisn-brown  on  dilution. 

Lii€rcUure,—Kiohn,  Ber.  1888,  21,  3241. 

Fast  Brown  (By.) ;  Resorcin  Dark  Brown 
(B.K.) ;  (HSO,-C,oHr.N,),C,H,(OH),.  Prepared 
by  the  action  of  diazotised  naphthionic  acid 
(2  mols.)  on  resorcinol  (1  mol.).  Brown  aqueous 
solution  gives  a  readily  soluble  precipitate  with 
hydrochloric  acid,  and  becomes  cherry-red  with 
sodium  hydroxide.  Solution  in  sulphuric  acid 
is  currant-ted. 

LiUrcUure,—!),  R.  P.  18861. 

Palatine  Blaek  A  (B.) ;  Wool  Blaek  4  B  and 
6B(A.);  Buffalo  Black  PY  (Sch.): 

HJSO,C,H4-N,-OioH,(SO,H)(OH)(NH,)N,-CioH, 

Prepcired  by  the  action  of  diazotised  sulphanilic 
acia  (1  mol.)  on  1  : 8-aminonaphthol-4-8ul- 
phonic  acid  in  acid  solution,  and  treating  the 
product  in  alkaline  solution  with  diazotised 
a-naphthylamine  (1  mol.)  in  alkaline  solution. 
Dark-blue  aqueous  solution  becomes  bluish-green 
with  hydrochloric  acid  and  pure  blue  with 
sodium  hydroxide.  The  solution  in  sulphuric 
acid  is  blue,  giving  a  dark-blue  precipitate  on 
dilution. 

Literature.— E.  P.  7713  of  1891  and  0894  of 
1893;  D.  R.  P.  71199,  91856;  F.  P.  213232; 
A.  P.  590088,  593790. 

Naphthol  Blue  Blaek  S;  Naphtiiol  Blaek 
12B(C.);  Naphthol  Blue  Blaek  B ;  Add  Blaek 
16d22  (L.) ;  Wool  Blaek  6  G  extra  eone.  (T.  M.) ; 
Naphthalene  Blaek  10  B  (P.) ;  Blue  Blaek  NB 
(K.);  Coomassle  Blue  Blaek  (Lev.);  Amide 
Blaek  10  BO  (M.) ;  Amldo  Aeid  Blaek  10  B  (A.) ; 
Naphthylamlne  Blaek  10  B  (By.) ;  Buffalo  Blaek 
NB(Sch.);  Agalma  Blaek  10  B  (B.) : 

NO,C,H4N,CioH,(SO,H),(OH)(NH,)N,-CoH5 

Prepared  by  the  action  of  diazotised  j9-nitro- 
anifine  (1  mol.)  on  1 :  8-aminonaphthol-3  :  6- 
disulphonio  acid  (H-acid)  in  acid  solution,  and 
treatmg  the  product  in  alkaline  solution  with 
diazotised  aniline.  The  dark-blue  aqueous 
solution  gives  a  blue  precipitate  with  hydro- 
chloric acid.  The  solution  in  sulphuric  acid 
is  green,  giving  a  blue  precipitate  on  dilution. 

LitercUure.—K  P.  1742  and  6972  of  1891 
D.  R.  P.  65651 ;  F.  P.  fourth  addition  to  201770 
A.  P.  480326. 

Domingo  Blue  Blaek  (various  marks)  (L.) 
Isomeric    with    the    preceding,     1 : 8-amino 
na^thol-3  : 5-disuIphonicacid  being  used  instead 
of  U-acidi    Mark  B  gives  a  violet  aqueous  solu 
tion,  and  a  green  solution  in  sulphuric  acid. 

LUerature.—E,  P.  19253  of  1895;   D.  R.  P. 
appl.  F  8626  ;  A.  P.  606438. 

Chrome  Patent  Green  N,  C  (K.) : 

(NOJ,C.H,-N,CiaH,(SO,H),(NHJ-OH 

I  i 

OH         N,C,H, 

Prepared  by  the  action  of  diazotised  aniline 
(1  mol.)  ana  diazotised  picramic  acid  (1  mol.) 
on  1  :  8-aminonaphthol-4  :  6-disulphonic  acid. 


Literature,— E.  P.  15074  of  1899 ;   D.  R.  P. 
110711;  F.  P.  291316. 
Blue  Blaek  N  (K.) : 

NO,CeH4N,CioH,(SO,H),(OH)NH, 

I 
N,-O.H, 

Prepared  by  the  action  of  diazotised  p-nitro- 

aniune  (1   mol.)  on    1 :  8-aminonaphthol-4  :  6- 

disulphonic  acid  in  acid  solution,  and  treating 

the  product  in  alkaline  solution  with  diazotised 

aniline. 

,     Literature.— Jy.  R.  P.  108266 ;  F.  P.  271070 ; 

A.  P.  563384,  613639. 

Supramlne  Blaek  BR  (By.).  The  special 
base  used  in  the  preparation  of  this  colouring 
matter  ia  p-aminophenyl  ether.  Two  mols.  (or 
one  of  this  and  one  of  another  base)  are  diazo- 
tised and  combined  with  1 : 8-aminonaphthol- 
4  :  6-  or  3  :  6-disulphonic  acid. 

Literature,— V.  P.  402546 ;  A.  P.  958830. 

Janus  Yellow  B  (M.): 

NrCH,),ClC,H4N,C,H,(OH),N,CeH4NO, 

Prepared  by  combining  diazotised  m-amino- 
phenvltrimethylammonium  chloride  with  m- 
nitrobenzeneazoresoroinol.  Yellowish  -  brown 
aqueous  solution  gives  a  yellowish-brown  pre- 
cipitate. Solution  in  sulphuric  acid  is  magenta- 
red,  becoming  yellow  on  dilution. 

Literature,— E,  P.  5119  of  1897;  D.  R.  P. 
93499,  95530,  99127,  100420;  F.  P.  264579; 
A.  P.  623697. 

Addine  Fast  Searlet  GG8, 4BS,  7  BS  (G.  J.). 
These  dyes  are  prepared  by  the  action  of  2 
mols.  of  a  diazo-  compound  on  the  substance 

HSO,CioH5(OH)NH-CONHC.H,(CHJSO»H 

aHCioHj(SO,H)NHCONH 

The  brand  GGS  is  made  from  diaaotiBed 
o-toluidine  (2  mols.),  4  BS  from  diazotised  o- 
toluidine  (1  mol.),  and  diazotised  /3-naphthyl- 
amine  (1  mol.),  and  7  BS  from  diazotised  fi- 
naphthylamlne  (2  mols.). 

Literature,— E.  P.  1781  of  1910 ;  D.  R.  P. 
appl.  J.  11718;  F.  P.  412138;  A.  P.  (appl.) 
541843. 

Benzo  Fast  Searlet  GS,  4  BS,  S  BS,  fto.  (By.). 
These  dyes  are  obtained  by  the  action  of  2  mda. 
of  a  diazo-  compound  on  the  urea  produced  by 
the  action  of  carbonyl  chloride  on  2  mols.  of  5- 
amino-a-naphthol-3-sulphonio  acid  (J-acid) :  t.e. 
HSO,-CioH^(OH)NH-(X)-NHC,oH5(OH)SO,H, 
or  by  treating  azo-  colouring  matters  from  diazo- 
compounds  and  J-acid  with  carbonyl  chloride 
or  with  carbon  disulphide. 

Literaure.—E.  P.  3615  of  1900;  D.  R.  P. 
122904, 126133, 126801, 128195, 132511, 133466; 
F.  P.  297367 ;  A.  P.  653498,  662122,  675629, 
675632. 

B.  Seeondaiy  Disazo-  Colouring  Hatten. 

Sudan  m  (A.) ;  Gerasine  Red  (G.)  (Barking 
Chemicals  Co.,  Ltd.);  Fat  PoneteU  G  (K.) ; 
Searlet  R  (C.  J.) ;  Searlet  B  Oil  Soluble  (B.  K^ : 
Moti  Red  2  R  (T.  M.) ;  Pyronal  Bed  B  (D.) ; 
OU  Red  0  (Sch.) : 

C,H5N,C.H4N,OioH.OH(« 

Prepared  by  the  action  of  diazotised  aminoazo 
benzene  on  /3-naphthol.    Insoluble  in  wat^; 
dissolves  in  sulphuric  acid  with  a  ipreen  colour. 


AZO-  COLOURING  MATTERS. 


473 


becoming  blue,  and  finally  red  and  precipitating 
on  dilation. 

Literature.— Nietzki,  Bar.  1880»  13,  1838; 
£.  P.  6003  of  1879 ;  D.  R.  P.  16483,  65779 ; 
F.  P.  134802. 

Poneeau  5  R  (M.)  (K.) ;  Erythrine  P  (B.) : 

C.H»N,-C^4N,CioH,(SO,H),OH 

Prepared  by  the  action  of  diazotised  aminoazo- 
benzene  on  /3-naphthol-3  :  6  :  8-trisuIphomo  acid 
in  alkaline  solution.  Cherry-red  aqueons  solu- 
tion gives  a  brown  precipitate  with  hydrochloric 
acid,  and  becomes  violet  with  sulphuric  acid. 

Literaiure.—E.  P.  2644  of  1882 ;  D.  R.  P. 
22038  ;  F.  P.  149249 ;  A.  P.  268607. 

Cloth  Red  6  (By.) ;  Cloth  Red  R  (D.) ;  Silk 
RedR(B.);  Fast  Slik  Red  (0.) : 

C,H,N,C,H4N,CioH4(SOaH)OH 

Prepared  by  the  action  of  diazotised  aminoazo- 
benzene  on  a-naphthol-4-sulphonic  acid  in 
alkaline  solution.  Dissolves  in  sulphuric  acid 
with  a  violet  colour,  giving  a  brownish-red 
precipitate  on  dilution. 

Uterature.—E.  P.  2237  of  1883 ;  D.  R.  P. 
26012. 

Croeei'lie  B  (Sch.).  The  disulphonic  acid 
corresponding  with  the  preceding ;  produced 
by  the  action  of  diazotised  aminoazobenzene 
on  a-naphthol-4  :  8-disulphonio  acid. 

LUeraiitre.''E.  P.  16776  and  16781  of  1886 ; 
D.  R.  P.  40671 ;  F.  P.  173083,  173084 ;  A.  P. 
333037. 

Croeetoe  AZ  (C).  Isomeric  with  the  pre- 
ceding. Prepared  from  a-naphthol-3  :  6-disul- 
pLomc  acid.  The  solution  in  water  is  red,  and 
in  sulphuric  acid  reddish- violet. 

BHliiantCioeefne  H  (C.)(B.K.)  (O.);  BrfllUmt 
Croetfne  3  B  (By.) ;  Brilliant  Croeeine  Uulsh 
(M.):  Brilliant  Croeeine  0  (K);  Brilliant 
Croeeibe,  extra  eone.  (T.  M.);  Cotton  Searlet 
(B.);  Poneeau  BO  extra  (A.);  Croeelfne  8  B 
(P.) ;  Croetfne  AZ  (K.  S.) ;  Paper  Searlet  (M.) : 

C,H,-N,-C,H4N,CioH4(SO,H)aOH 

Prepared  by  the  action  of  diazotised  aminoazo- 
benzene on  /3-naphthol-6  :  8-disulphonic  acid. 
Dissolves  in  sulpnurio  (Bhdd  with  a  reddish- 
violet,  becoming  first  bluer  and  then  red  on 
dilution. 

LUerature.—E.  P.  816  of  1884;  D.  R.  P. 
36491  ;  F.  P.  169998 ;  A.  P.  314939. 

Azo  Aeld  Violets  (various  marks)  (By.)  are 
prepared  from  diazotised  aminoazobenzene  (and 
similar  oompounds)  and  1 : 8-dihydroxynaph- 
thalene-4-Bu^honic  acid  (or  disulphonic  acid). 

Literature,— '1&.  P.  3397  of  1890;  6984  of 
1891 ;  D.  R.  P.  67021,  64017. 

Sadan  IV  (A.)  (D.J ;  Oil  Ponceau  (M.)  (W.) ; 
Cerotlne  Poneeau  8  B  (C.  J.) ;  Fat  Ponceau  R 
(K.i;  Scarlet  BBB  Oil  Soluble  (B.  K.);  Red 
P  1566  (P.).  {See  also  Fast  Azo  Garnet,  p.  467.) 
C^H/Nj-C,  H,N,-C|o H,OH.  Prepared  from 
diazotised  o-aminoazotoluene  and  jS-naphthol. 
Insoluble  in  water,  but  soluble  in  alc<^ol  or 
benzene  with  a  bluish-red  colour.  Sulphuric 
acid  ^vee  a  blue  solution,  which  yields  a  red 
predpitate  on  dilution. 

Cloth  Red  B  (By.)  (D.) : 

C,H/N,C,H,N,CioH,(SO^)OH 

Prepared  by  the  action  of  diazotiwd  o-amino- 
azotoluene    on     a-naphthol-4-sulphomc     acid. 


The  red  aqueous  solution  gives  a  red  precipitate 
with  hydit>chloric  acid,  and  on 'adding  sodium 
hydroxide  to  the  solution  it  becomes  violet. 
The  solution  in  sulphuric  acid  is  blackish-blue. 

Literature,— K  P.  6003  of  1879 ;  D.  R.  P. 
16482. 

Cloth  Red  0  (0.) ;  Cloth  Red  G  extra  (By.) ; 
Cloth  Red  GA  (A.) ;  Aeidol  Cloth  Red  G  (T.  M.) : 

C7H/N,C^,-N,CioH,(80,H)OH(/5) 

Produced  by  the  action  of  diazotised  amino- 
azotoluene  on  i3-naphthol-6-sulphomc  acid. 
Dissolves  in  water  with  a  red-brown  colour 
giving  a  similarly  coloured  precipitate  on  addi- 
tion of  acid.  Dissolves  with  a  blue  colour  in 
sulphuric  acid,  giving  a  brownish-red  precipitate 
on  dilution. 

Literature,— E.  P.  6003  of  1879 ;  D.  R.  P. 
16482. 

Cloth  Red  B  (O.)  (K.) ;  doth  Red  0  (M.) ; 
Cloth  Red  BA  (A.) ;  Cloth  Red  BB  (D.) ;  Ftot 
Bordeaux  0  (M.) ;  Ftot  Hilling  Red  B  (Lev.) ; 
Wool  Red  B  (C.) : 

C^7N,C^.-N,-CioH4(SO,H),OH(i3) 

Prepared  by  the  action  of  diazotised  aminoazo- 
toluene  on  /3-naphthol-3  :  6-di8ulphonic  acid  (R- 
salt).  Aqueous  solution  red,  becoming  brownish 
on  addition  of  hydrochloric  acid.  Dissolves  in 
sulphuric  acid  with  a  blue  colour,  giving  a 
brownish-red  precipitate  on  dilution. 

Literature  as  under  preceding  colour  and 
£.  P.  636  of  1880. 

Cloth  Red  3  G  extra  (By.) ;  Cloth  Red  8  GA 
(A.);  Cloth  Red  8 G  (0.) : 

C7H7N,C,H,N,CioH,(SO,H)NH, 

Prepared  by  the  action  of  diazotised  amino- 
azotoluene  on  /3-nAphthyIamine-6-sulphonic  acid. 
The  red  aqueous  solution  gives  with  hydrochloric 
acid  a  dark  reddish-brown  precipitate.  The 
solution  in  sulphuric  acid  is  dark  greenish-blue, 
and  gives  a  brownish-red  precipitate  on  dilution. 
Bordeaux  BX  (By.) : 

C.H,N,CgHeN,CioH4(SO,H)OH 

Prepared  by  the  action  of  diazotised  amino- 
azozylene  on  /3-naphthol-6-sulphonic  acid. 
Solution  in  water  is  brownish-red,  and  gives  a 
brownish-red  precipitate  with  hjjrdrochlorio  acid 
or  sodium  hydroxide.  Sulphunc  acid  dissolves 
colour  to  a  ^reen  solution,  which  gives  a  reddish- 
brown  precipitate  on  dilution.        • 

Literaiure,—E.  P.  6003  of  1879 ;  D.  R.  P. 
16482. 

Union  Fast  Claret  (Lev.) : 

C8H,N,CaHg-N,C,oH,(SO,H),OH(/3) 

Prepared  by  the  action  of  diazotised  aminoazo- 
xylene  on  iB-naphthol-3 : 6-di8ulphonic  acid. 
Soluble  in  water  with  a  Bordeaux-red  colour; 
reddish-brown  flocculent  precipitate  on  adding 
dilute  acid.  Solution  in  sulphuric  acid  dark 
blue,  giving  reddish- brown  precipitate  on 
dilution. 

LiteraJlure,—E.  P.  6003  and  6021  of  1879, 
636  of  1880 ;  D.  R.  P.  22010 ;  A.  P.  210233, 
246221. 

Croeeine  Scarlet  8  B  (By.)  (K.)  (T.  M.); 
Erythrlne  2  R  (B.) ;  Poneeau  4  RB  (A.) : 

HSOaC,H4N,C.H4N,CioH,(80,H)OH 

Produced  bv  the  action  of  diazotised  aminoazo- 
benzenesulphonic     acid     on     i3-naphUiol-8-sul- 


474 


AZO-  COLOURING  MATTERS. 


phonic  acid  (Bayer*s).  Solution  not  prooipi- 
tatcd  by  alkali ;  a  rod  precipitate  produced  by 
barium  chloride,  becoming  dark-violet  and 
crystalline  on  boiling.  Diuolyes  in  sulphuric 
acid  with  a  deep-blue  colour,  becoming  violet 
and  then  red  on  dilution. 

Litenaurc—E.  P.  1225  and  2030  of  1881, 
2411  of  1883,  8390  of  1884 ;  D.  R.  P.  18027  ; 
F.  P.  142024 ;  A.  P.  256380. 

Fnsi  Seariet  B  (K.) : 

HSO,C,H4N,C,H4'N,-CxoH8(SO,H)OH 

Prepared  by  the  action  of  diazotised  aminoazo- 
benzenemonoBulphonio  acid  on  j3-naphthol- 
6-Bulphonio  acid  (Sch&ffer's).  Red  solution 
in  water,  giving  brown  precipitate  with  hydro- 
chloric acid  and  a  red-violet  colouration  with 
sodium  hydroxide.  Solution  in  sulphuric  acid 
is  blue,  and  becomes  red  on  dilution. 

Literature,— D.  R.  P.  16482. 

Cloth  Seariet  G  (K.) : 

HSO,-C.H4N,C,H4N,CioH,OH 

Prepared  by  the  action  of  diazotised  aminoazo- 
benzenemonosulphonio  acid  on  /3-naphthol. 
The  scarlet  solution  in  water  gives  a  brown 
precipitate  with  sodium  hydroxi(£,  and  becomes 
yeUower  on  addition  of  hydrochloric  acid  when 
dilute,  but  in  concentrated  solutions  a  light- 
red  precipitate  is  produced.  The  solution  in 
sulphuric  acid  is  neen,  becoming  red  on  dilution. 

Literature.— t,  P.  5003  and  5021  of  1879, 
536  of  1880 ;  D.  R.  P.  16482. 

Mining  Orange  (D.) : 

HSO,CJE[4N,C.H4N,C.H,(CO,H)OH 

Prepared  by  the  action  of  diazotised  aminoazo- 
benzenemonosulphonic  acid  on  salicylic  acid. 
Orange-red  solution  in  water,  giving  ^yish- 
yellow  precipitate  with  hydrocmoric  acid,  and 
a  dark-red  solution  and  precipitate  with  sodium 
hydroxide.  The  solution  in  sulphuric  acid  is 
violet,  giving  a  groyish-yellow  precipitate  on 
dilution. 

Paneeaa  8  RB  (A.)  (B.  K.) ;  New  Red  L  (K.) ; 
Poneean  B  extra  (M.) ;  Fast  Poneean  B  (B.) ; 
Double  Seariet  (K.) ;  Seariet  EC  (G.) ;  Blaekley 
Seariet  (Lev.) ;  Seariet  B  (P.): 

HSO,C.H4N,-C,H,(SO.H)N,-OioH,OH 

Prepared  from  diazotised  aminoazobenzene- 
disiuphonic  acid  and  i9-naphthol.  Solution  not 
precipitated  by  alkali;  a  brown  flooculent 
precipitate  b}r  dilute  acids.  Dissolves  in  sul- 
phuric acid  with  a  green  colour,  becoming  first 
olue  and  finally  brown  and  precipitating  on 
dilution. 

Literature.— E.  P.  5003  of  1879,  529  of  1880 ; 
D.  R.  P.  16482  ;  A.  P.  224927, 224928  ;  Nietzki, 
Ber.  1880,  13,  800,  1838;  MiUer,  ibid.  542, 
803,  980. 

Croeebe  Seariet  0  extra  (K.) : 

H80,-C,H4'Nt-CcH,(SO,H)N,*CioH4(80|H)'OH 

Prepared  by  the  action  of  diazotised  aminoazo- 
benzenedismphonic  acid  on  /3-naphthol-8-sul- 
phonic  acid.  The  yellowish-red  aaueous  solu- 
tion gives  a  violet  colouration  with  hydrochloric 
acid  or  sodium  liydroxide.  The  solution  in 
sulphuric  acid  is  blue,  becoming  yellowish-red 
on  dilution. 

Croeei'ne  Seariet  7  B  (Ruch  &  Fils) ;  Poneean 
6  RB  (A.) ;  Croeeine  Seariet  8  B  (K.)  (By.) ; 
Erythrine  7  B  (B.) ;  Coeeeine  7  B  (P.) : 


HSO,C,H,-N,C,H.-N,-CioH5(SO,H)OHO) 

Prepared  bv  the  action  of  diazotised  aminoazo- 
toluenesulphonio  acid  on  /3-naphthol-8-sulphonic 
acid  (Bayer's)  in  presence  of  alkali.  Reaemblee 
croeeine  scarlet  3  B  in  general  properties ;  givee 
a  crystalline  magnesium  salt  on  adding  magne- 
sium sulphate  to  hot  concentrated  solution  and 
allowing  to  cool.  Dissolves  with  a  blue  colour 
in  sulphuric  acid,  becoming  red  on  dilution. 

Literature  as  for  crocebie  scarlet  3  B ;  and 
A.  P.  256375. 

Orseilline  2  B  (By.).  Prepared  by  the  action 
of  diazotised  aminoazotoluenesulphonio  acid 
on  a-naphthol-4-sulphomo  acid.  Dissolves  with 
a  blue  colour  in  sulphuric  acid,  becoming  red 
on  dilution. 

Literature.— E.  P.  2237  and  4237  of  1883 ; 
D.  R.  P.  26012. 

Bordeaux  G  (By.)  (M.).  Prepared  by  the 
action  of  diazotised  aminoazotoluenemono- 
sulphonic  acid  on  i3-naphthol-6-Bulphonic  acid. 

Literature.— E.  P.  5003  of  1879 ;  D.  R.  P. 
16482,  16483. 

Erioehrome  Verdone  A  (Q.) : 

HSO,C,H4N,C7H,(OH)N,C,oH.OH 

Sulphanilic  acid  is  diazotised  and  combined  with 
fi»-amino-i>-oresol  and  the  product  is  diazotised 
and  comoined  with  /S-naphthol.  The  violet 
aqueous  solution  becomes  claret-red  with 
hydrochloric  acid,  and  blue-green  with  sodium 
hydroxide.  The  solution  in  sulphuric  acid  is 
gpreen,  giving  a  brown-red  precipitate  on  dilu- 
tion. Wool  is  dyed  in  claret-red  shades  from 
an  acid- bath  ^nd  on  chroming  becomes  blue- 
green. 

Literature.— E.  P.  13903  and  13904  of  1909 ; 
D.  R.  P.  201377.  224024,  227197 ;  F.  P.  404536. 

Poneean  10  RB  (A.) : 

HSO,-C,H4N,-CgH,(OCH,)N,CioH5(SO,H)OH 

Sulphanilic  acid  is  diazotised  and  combined 
with  o-anisidine,  and  the  product  diazotised 
and  combined  with  iB-naphthol-8-sulphonic  acid. 
The  aqueous  solution  is  red,  and  Uiat  in  sul- 
phuric acid  blue. 
Janna  Red  B  (M.) : 

N(CH,),ClC,H4N,C,H,(CH,)N,C,oH.-OH 

Prepared  by  diazotisins  m-aminophenyltri- 
metnylammonium  chloriae,  combiiung  with 
m-toluidine,  diazotising  the  product  and  com- 
bining witli  iS-naphthol.  The  red  aqueous 
solution  gives  a  brownish-red  precipitate  with 
hydrochloric  acid  and  a  bluish- violet  precipitate 
with  sodium  hydroxide.  The  solution  in  sul- 
phuric acid  is  green,  and  gives  a  red  precipitate 
on  dilution. 

Literature.— E.  P.  5119  of  1897,  10696  of 
1898;  D.  R.  P.  93499,  95718,  98585,  100919; 
F.  P.  264579 ;  A.  P.  623697. 

Neutral  Grey  G  (A.) : 

C.H5N,C,oH,N,C,oH4(SO,H)(NHJOH 

Diazotised  benzeneazo-a-naphthvlamine  is  com- 
bined with  7-amino-a-naphthol-3-sulphonic  acid 
(7-acid).  It  sives  a  blaclush-vlolet  solution  in 
water,  and  a  bluish-green  in  sulphuric  acid. 

Literature.— J>.  R.  P.  appl.  A.  3743. 

Myanza  Blaek  B  (A.) : 

NH,-C«H4-N,-C,oH,-N,-C,oH,(SO,H)(NHJ-OH 
Prepared  by  the  action  of  diazotised  p-amino- 


AZO-  COLOURING  MATTERS. 


476 


bezizeneazo-a-naphthylaznine  (only  one  amino- 

froup  is  diazotised)  ^  on  7-ammo-a-naphthol- 
-Bulphonic  add  (y-aoid).  Solation  is  dark- 
violet  and  ^ivee  violet  precipitates  with  hydro- 
ohlorio  aoid  and  sodium  hydroxide.  The 
solation  in  sulphuric  acid  is  blue,  and  eives  a 
violet  ptrecipitate  on  dilution.  The  colouring 
matter  itaeli  produces  only  indifferent  shades, 
but  when  diazotised  coid  developed  on  the  fibre 
fast  shades  are  obtained.  When  developed 
with  m-tolylenediamine,  a  brown-black  is 
obtained,  and  with  i9-naphthol  a  navy-blue. 

Liter(Uure.-^E.  P.  277  and  6630  of  1892; 
D.  R.  P.  72393,  72394,  80421 ;   P.  P.  221378 ; 
A.  P.  491410,  611688,  612167. 
Coomassie  Wool  Blaek  R  (Lev.) : 

NH,C,H4N,C,oH.N,CiaH,(SO,H)OH 

Prepared  by  the  action  of  diazotised  p-acetyl- 
ammobenzeneazo-a-naphthylamine  on  /3-naph- 
thQl-6-sulphonic  acid  (Schafier*s),  and  hydrolys- 
ixig  the  product.  The  dark-violet  solution 
gives  a  precipitate  with  hydrochloric  acid.  The 
solution  in  sulphuric  acid  is  green,  becoming 
red  on  dilution. 

Literature,— E.  P.  24980  of  1899 ;  D.  R.  P. 
122467  ;  A.  P.  664167,  664168. 

Ooomassle  Wool  Blaek  S  (Lev.): 

NH,-C^4-N,-CioH,N,C,oH4(SO,H),OH 

Prepared  as  the  preceding  dvestuff,  the  final 
component  being  /3-naphthol-3  :  6-disulphonic 
acid  (R-salt).  Tne  blue-black  aqueous  solution 
becomes  redder  with  hydrochloric  acid.  The 
solution  in  sulphuric  acid  is  green,  becoming 
red  on  dilation. 

Literature, — as  above. 

Dlamlnogon  BB  extra  (C.) : 

NH,C,oH,(BO^)N,.CioH,N,C^oRi(SO,H)OH 

Monoacetyl-1  :  4-naphthylenediamine-7-suIpho- 
nic  acid  ia  diazotised  and  combined  with 
a-naphth^amine,  the  intermediate  product 
diazotised  and  combined  with  7-amino-a- 
naphthol-3-sulphonic    acid    ('/•acid),    and    the 

Sroduct  hydrblysed.  When  diazotLsed  and 
eveloped  on  the  fibre  a  fast  black  is  produced. 

Literature.—E,  P.  16444  of  1893 ;  D.  R.  P. 
78831,  79910;  F.  P.  232299;  A.  P.  633463, 
660796. 

Diamlnogen  Blue  BB  (G.) ;  Dlazanil  Blue  BB 
(M.).  Prepared  as  the  preceding,  but  the  end 
component  is  ^i3-naphthol-6-sulphonio  acid 
(Schaffer*s). 

Literaiure  as  above. 

Diamlnogen  Blae  0  (G. ).  Prepared  as  above, 
the  end-component  being  /3-naphthol-3 : 6- 
disulphonic  acid  (R-salt). 

Literature  as  above. 

Dlazo  Indigo  Blue  is  an  analogous  product. 

Zambesi  SlEy  Blue  4  B  (A.).  Prepared  from 
diazotised  monoacetyl-3  :  6-diaminocresyl  methyl 
ether  combined  with  a-naphthylamine,'  the 
intermediate  product  bein^  diazotised  and 
combined  witn  /3-naphthoT-6-Bulphonio  acid 
and  the  end-product  saponified.  The  reddish- 
violet  aqueous  solution  becomes  redder  with 

I  AU  the  authorities  give  the  above  oonBtituUon  for 
this  colourliig  matter,  but  It  is  generally  understood  that 
a  benienoid  amino-  group  is  diazotised  preferably  to  a 
Dapbthalenoid  amino-  group. 

*  According  to  Buptrocic  (Zeitsch.  Farben-Ind.  1002, 
1,  224).  The  patents  quoted  give  the  0-  or  7-Bulpbonic 
acid  ai  Inteimediate  component. 


hydrochloric  acid  and  bluer  with  sodium 
hydroxide.  The  solution  in  sulphuric  acid  is 
blue,  and  becomes  violet-red  on  dilution. 

Literature.— E.  P.  2188  of  1901 ;  D.  R.  P. 
126172. 

Victoria  Blaek  B  (By.): 

HSO,CeH4N,CioH,N,-CioH4(OH),SO,H 

Prepared   by   the   action  of   diazotised  ]}-8ul- 

§hoDenzeneazo-a-naphthvlamine  on  1 :  8-dihy- 
roxynaphthalene-4-8ulphonio  acid.  The  dark 
reddish  -  violet  aqueous  solution  gives  with 
hydrochloric  acid  a  Bordeaux-red  precipitate, 
and  with  sodium  hydroxide  becomes  dark- 
blue  violet.  The  solution  in  sulphuric  acid  is 
moss-ffreen,  ohanging  on  dilution  to  sea-green, 
and  then  to  bluish-rra. 

Literature,— E.  P.  13666  of  1889 ;   D.  R.  P. 
61707,  62946  ;  P.  P.  200620 ;  A.  P.  466202. 
Buffalo  Black  10  B(Sch.);  Acid  Black  N  (P.): 

H803C,H4-NaCioH,-N,CioHs(SOaH)j|(OH)NH, 

Prepared  as  the  preceding,  except  that  1  : 8- 
aminonaphthol-3  :  6-diaulphonic  acid  (H-acid)  is 
used  as  the  end-component.  The  solutions  in 
water  or  sulphuric  acid  are  blue. 

Literature,— A,  P.  618963. 

Jet  Blaek  R  (By.) : 

(HSO,),C,H,N,GioH.N,CioH,-NHG,H, 

Prepared  by  the  action  of  diazotised  disulpho- 
benzeneazo-a-naphthylamime  on  phenyl-&- 
naphthylamine.  The  bluish  -  violet  aqueous 
solution  gives  a  bluish-black  precipitate  with 
hydrochloric  acid,  and  a  soluble  violet  precipitate 
with  sodium  hydroxide.  Sulphuric  acid  dis- 
solves the  colouring  matter  to  a  blue  solution, 
which  gives  a  greenish-blue  precipitate  on 
dilution. 

Literature.— E,  P.  14442  of  1888 ;  D.  R.  P. 
48924 ;  F.  P.  193430 ;  A.  P.  426886. 

DiamoDd  Black  F  (By.)  (B.)  (L.) ;  Chrome 
Fast  Black  FRW  (I.);  ChroMo  Deep  Black 
(T.  M.);  SaUcin  Black  D  (K.) ;  Era  Black  F 
(Lev.);  Fast  Chrome  Black  B  (Sch.);  Fast 
Mordant  Black  B,  T  (M.) ;  Chrome  Black  J  (H.) : 

GO,HG,H,(OH)N,GioH,N,G,oH,(SO,H)OH 

Aminosalicvlic  acid  is  diazotised  and  combined 
with  a-napnthylamine,  and  the  product  diazo- 
tised and  combined  with  a-naphthol-4-  (or  6-) 
sulphonio  acid.  Bluish-violet  solution  gives 
violet  precipitate  with  hydrochloric  acid,  and 
becomes  blue  with  sodium  hydroxide.  Solution 
in  sulphuric .  acid  is  greenish,  giving  a  violet 
precipitate  on  dilution.  Similar  dyestuffs  are 
Era  Blacks  J  and  NO  (Lev.). 

Literature.— E,  P.  8299  of  1889;  D.  R.  P. 
61604 ;  F.  P.  198621 ;  A.  P.  438438. 

Nerol  B  (A.) : 

C,H4NHGeH,N,C,oH,-N,CioH4(SO,H), 

I  I 

SO,H  OH 

p-Aminodiphenylamine-o-sulphonic  acid  is  di- 
azotised and  combined  with  a-naphthylamine, 
and  the  intermediate  product  is  diazotised  and 
combined  with  /3-naphthoI-3  :  6-disulphonio  acid 
(R-salt).  Dark  violet-blue  solution  in  water 
gives  a  blue  precipitate  with  hydrochloric  acid. 
The  solution  in  sulphuric  acid  is  dark  blue- 
violet,  giving  a  blue-violet  precipitate  on  dilu- 
tion. 


476 


AZO-  COLOURING  MATTERS. 


Literature,— E.  P.  24527  of  1897 ;  D.  R.  P. 
101274;  F.  P.  271609. 

Nerol  2  B  (A.).  Prepared  as  the  precedinff, 
except  that  the  last  component  Is  a-naphthol-4- 
Bulphonio  acid. 

Froperties  and  literature  as  above. 

Diamond  Green  (By.) : 

C.H,(OH)NgCioH,-N,CioH4(SO,H)(OH), 

CO,H 

Prepared  by  dlazoUsing  aminosalio^Uo  acid 
ana  combining  with  a-naphthylamine,  the 
intermediate  product  being  diazotised  and 
combined  with  1 : 8-dihydroxynaphthalene-4- 
Bulphonio  acid.  The  blackish-violet  aqueous 
solution  gives  a  dark  reddish- violet  precipitate 
with  hyiuochlorio  acid,  and  becomes  dark  blue 
with  sodium  hydroxide.  The  solution  in 
sulphuric  acid  is  bmish-green,  becoming  greenish- 
blue,  and  finally  giving  a  blaokish-violet  pre- 
cipitate on  dilution. 

Literature,— E.  P.  8299  of  1889  1828  of 
1890 ;  D.  R.  P.  61604,  62003 ;  P.  P.  198621  ; 
A.  P.  438438. 

Nsphthybunine  BUek  D  (C.)  (K.);  Deep 
Blaek  D,  oone.  (T.  M.) ;  Coomassie  Wool  Blaek  D 
(Lev.) ;  Buffalo  Blaek  AD  (Sch.) ;  Aeid  Blaek 
NN(L);  Naphthalene  Blaek  R  (H.) : 

(HSO,),CioH5N,CioH,N,CioH«NH, 

a-Naphthylamine-3  :  6-diBulphonic  acid  is  diazo- 
tised and  combined  with  a-naphthylamine, 
and  the  intermediate  product  diazotised  and 
combined  with  a-naphthylamine.  The  violet- 
black  aqueous  solution  gives  a  black  precipitate 
¥rith  hydrochloric  acid.  The  solution  in  sul- 
phuric acid  is  bluish-black,  and  on  dilution 
oecomes  green,  and  finally  gives  a  black 
precipitate. 

literature.— E.  P.  18425  of  1888 ;  D.  R.  P. 
50907 ;  F.  P.  170342  ;  A.  P.  412440. 

Naphthylamlne  Blaek  4  B  (0.) ;  Naphthalene 
Blaek  D  (H.)  is  a  mixture  of  Naphthol  blue- 
black  and  the  preceding  colouring  matter. 

NM»hthyI  Bine  Black  N  (0.) ;  Alphyl  Blue 
Blaek  0  (M.).  4 : 7-Di8ulphonaphthaleneazo- 
a-naphthylamine  is  diazotised  and  combined 
with  aminonaphthol  ethyl  ether.  The  dark- 
violet  aqueous  solution  turns  blue  and  gives  a 
blackish-blue  precipitate  with  hydrochloric 
acid,  and  becomes  blue  and  precipitates  with 
sodium  hydroxide.  The  solution  m  sulphuric 
acid  is  dark  blue,  which  on  dilution  becomes 
blue,  and  finally  bluish-violet. 

Literature,— Chem.  Ind.  1896,  19,  548. 

Anthraelte  Blaek  B  (0.) ;  Phenylene  Blaek 

(P.): 

{HSOJ,Ci,H,N,CioH,N,-C»H,(NHC,H,), 

a-Naphthylamine-3  :  6-(4  :  7-in  the  case  of  the 
latter  dye)  -disulphonic  acid  is  diazotised  and 
combined  with  a-naphthylamine,  and  the  pro- 
duct diazotised  and  combined  with  diphenyl-m- 
phenylened  iamine.  The  dull-violet  aqueous 
solution  gives  a  violet  precipitate  with  hydro- 
chloric acid.  The  solution  in  sulphuric  acid 
is  black,  giving  a  greenish-black  precipitate  on 
dilution. 

Literature,— E.  P.  4825  and  7977  of  1889 ; 
D.  R.  P.  62616,  61202 ;  F.  P.  196793,  197963 ; 
A.  P.  502912. 


Naphthol  Blaek  B  (C.) ;  Brilliant  Blaes  B 
(B.);  Naphthol  Blaek  OPAS  (Lev.);  Buffalo 
BhMk  2  B  (Sch.) ;  Carbon  Blaek  B,  8  B  (H) ; 
Wool  Blaek  B,  8G  (D.) : 

(HSO,)aCioH,-N,CjoH.-N,-C,oH4(SO,H),.OH 

/3-Naphthylamine-6  :  8-disulph5nic  acid  is  dia- 
zotised and  combined  with  a-naphthylamine, 
and  the  product  diazotised  and  combined  with 
/3-naphthol-3  :  6-disulphonic  acid  (R-salt).  The 
violet  aqueous  solution  gives  with  hydrochloric 
acid  a  radish- violet  and  with  sodium  hydroxide 
a  blue  precipitate.  The  solution  in  sulphuric 
acid  is  green,  becoming  bluer  on  dilution,  and 
then  giving  a  reddish- violet  precipitate. 

Ltterature,—E.  P.  9214  of  1885;  D.  R.  P. 
39029  ;  F.  P.  170342  ;  A.  P.  345901. 

Naphthol  Blaek  2  B  (Lev.)  is  prepared  as 
the  preceding,  but  starting  with  a-naphthyl- 
amine-3 : 6-diBulphonic  acid. 

Naphthol  Blaek  6  B  (G.)  (K.) ;  Add  Blaek 
6B(H.);  Brilliant  Blaek  BD  (B.) ;  Naphthalene 
Blaek  5  B  (P.) ;  Naphthol  Blaek  (D.) ;  Aeld 
Blaek  5  B,  BR  (T.  M.) ;  Wool  Blaek  (B.  K.) ; 
Aeldol  Blaek  (T.  M.)  is  prepared  by  the  action 
of  diazotised  4 : 7-disulphonaphthaleneazo-a- 
naphthylamino  on  iS-naphtholdisulphonic  acid 
(R-salt).  Aqueous  solution  dark  violet,  becom- 
ing dark  blue  with  acid  or  alkali ;  dissolves  in 
sulphuric  acid  with  a  dark-green  colour,  becoming 
blue  on  dilution. 

Literature,— E.  P.  9214  of  1885 ;  D.  R.  P. 
39029 ;  F.  P.  170342 ;  A.  P.  346901. 

Sulphone  Blaek  6,  R  (By.) : 

C.H,N,CioH,(SO,H)N,C,oH4(OH),SO,H 

Diazotised  aniline  is  combined  with  a-naphthyl- 
amine-6 -(or  7)-sulphonic  acid«  the  pzxxiact 
diazotised  and  combmed  with  1 : 8-dihydroxy- 
n&phthalene-4-8ulphonio  acid.  *  The  aqueous 
solution  is  reddish- violet,  and  that  in  sulphurio 
acid  is  greenish-blue. 

Blebrieh  Patent  Blaek  BO  (K.) : 

(HSO,)AoH,-N,CioH,-N,CioH4(SO,H),OH 

I 
SO,H 

a-Naphthvlaminedisulphonio  acid  is  diazotised 
and  combined  with  a-naphthylamine-6-(or  7)- 
sulphonic  acid,  the  product  dii^otised  and  com- 
bined with  i3-naphthol-3 :  6-disulphonic  acid 
(R-salt).  The  dark  reddish-violet  aqueous 
solution  is  turned  slightly  blue  with  hydrochloric 
acid  and  pure  blue  with  sodium  hydroxide. 
Solution  in  sulphuric  acid  is  dark  greenish- 
blue,  becoming  aark  violet  on  dilution. 

Literature,— E,  P.  2718  of  1892 ;  D.  R.  P. 
73901,  83672,  84460;  F.  P.  219424;  A.  P. 
476070,  546068,  546069. 

Blebrieh  Patent  Blaek  4  AN  (K.) : 

HSO,CioH,N,CioH,(SO,H)N,CioH«-NH, 

Prepared  from  diazotised  naphthionic  acid  and 
a-naphthylamine-6-(or  7)-suJphonio  add,  the 
product  bein^  diazotised  and  combined  with 
a-naphthylamine.  The  violet  aqueous  solution 
gives  a  bluish-black  precipitate  with  hydro- 
chloric acid,  and  becomes  blue  with  sodium 
hydroxide.    Solution     in     sulphuric     acid 


IS 


bluish-green,  giving  a  bluish-blaok  precipitate 
on  dilution.    Similar  dyestuffs  bear  the  brands 
6  AN,  4  BN,  and  6  BN. 
References  as  above. 


AZO-  COLOURING  MATTERS. 


477 


Anthraoene  Acid  Blaek  (various  markB)  (C.) : 

OHC,H,N,C,oH,N,*CioH4(SO,H),OH 

I  I 

CO,H      SO,H 

AminoBalicylic  acid  is  diazotised  and  combined 
with  a-naphthy]amine-6-(or  7)-8ulphonic  acid, 
and  the  product  diazotised  and  combined  with 
i9-naphthol-3  :  6-disulphonic  acid  (R-salt).  The 
violet  aqueous  solution  gives  a  violet  precipitate 
with  hydrochloric  acid,  and  becomes  bluish- 
violet  with  sodium  hydroxide.  Solution  in 
sulphuric  acid  is  green,  giving  a  violet  precipitate 
on  dilution. 

Naphthalene  Add  Black  4  B  (By.) : 

HSO,C,H4N,C,oH5(SO,H)N,C,oH,NH, 

Metanilio  acid  is  diazotised  and  combined  with 
the  same  acid  as  in  the  preceding,  and  the 
product  diazotised  and  comoined  with  a-naph- 
thylamine.  Aqueous  solution  is  violet,  becoming 
blue  with  hydrochloric  acid,  and  redder  with 
sodium  hydroxide.  Solution  in  sulphuric  acid 
is  blue,  becoming  violet  on  dilution. 

Solphocyanines  (various  marks)  (By.) ;  Tolyl 
Blue  GR  extra,  5  R  extra  (M.) ;  Coomassie  Navy 
Blue  (various  marks)  (Lev.)  are  prepared  from 
diazoUsed  metanilic  acid,  which  is  combined 
with  a-naphthylamine,  the  product  being 
diazotised  and  combined  with  phenyl-  or  tolyl- 
a-naphthylamine-8-8ulphonio  acid.  The  violet 
aqueous  solution  gives  a  greyish-blue  precipitate 
with  hydrochloric  acid.  Solution  in  sulphuric 
acid  is  blue,  becoming  greener  and  giving  a  blue 
precipitate  on  dilution.  Similar  dyes  are 
Snlphone  Blaek  8  B,  4  BT  (By.)  (c/.  D.  R.  P. 
76671). 

Literature.— J),  R.  P.  118666. 

Sulphoncyamlne  Blaek  B,  2  B  (By.) ;  Tolyl 
Blaek  B,  BB  (M.).  a-Naphthylamine-6-Bulpho- 
nic  acid  is  diazotised  and  combined  with  a- 
naphthylamine  (or  with  Cleve*s  acids),  the  pro- 
duct being  diazotised  and  combined  with 
phenyl-a-naphthylamine-8-sulphonic  acid.  The 
aqueous  solution  is  violet,  and  that  in  sulphuric 
acid  dark  blue. 

Liieralure.—J).  R.  P.  118666. 

BrIlllaBt  Croeeme  9  B  (C.) : 

(HSO,),CioH8-N,C,H4-N,CioH4(SO,H),OH 

^Naphthylamine-6  :  8-disulphonic  acid  is  dia- 
Kotised  and  combined  with  aniline,  the  product 
being  diazotised  and  combined  with  a  mixture 
of  i3-naphthol-3  :  6-  and  6  :  S-disulphonic  acids. 
The  blmsh-red  aqueous  solution  becomes  darker 
and  bluer  with  hydrochloric  acid,  and  brownish 
with  sodium  hydroxide.  The  solution  in 
sulphuric  acid  is  l>lue,  changing  to  bluish-red  on 
dilution. 

Fast  Sulphone  Black  F,  FB  (K.  S.): 

H80,-CioH.-N,-CioH,(SO,H),(OH)N,CioH,-OH 

Naphthionio  acid  is  diazotised  and  combined 
with  1 :  8-aminonaphthol-3  :  6-disulphonic  acid 
(H-acid),  the  product  diazotised  and  combined 
with  3-naphthol.  The  solution  in  water  is 
greenish- black,  and  in  sulphuric  acid  blackish- 
violet. 

Literature,'-E.  P.  14768  of  1003 ;  D.  R.  P. 
168134. 

C.  Tetnio-  Mooring  Matters. 

Anthraeene    TeOow   C   (C.)   (By.);     Fact 


Mordant  Yellow  GI  (B.) ;  Acid  Alizarine  TeUow 

RC  (M.) : 

o^C.H4N,C,H,(C0,H)-0H 
^"\C,H4N,C,H,(C0,H)0H 

Prepared  from  tetrazotised  thioaniline  and 
salicylic  acid  (2  mols.).  The  light  yellowish- 
brown  aqueous  solution  gives  a  creenish-brown 
precipitate  with  hydrochloric  acid.  The  solution 
in  sulphuric  acid  is  dark  reddish-violet,  giving 
a  yellowish-grey  precipitate  on  dilution. 
Milling  Red  G  (G.) : 

D,,..-C,H«N,C,oH,(SO,H)OH 
°\C,H^N,CioH5(SO,H)OH 

Similarly  prepared  from  tetrazotised  thioaniline 
and  3-naphtnol-6-8ulphonic  acid  (Schaflfer^s). 
The  orange-red  aqueous  solution  gives  a  brown 
precipitate  with  hydrochloric  acid.  The  solution 
in  sulphuric  acid  is  reddish-violet,  giving  a 
brown  precipitate  on  dilution. 

Cotton  Yellow  G  (B.)t  Benzo  Fast  Yellow 
6  GL  (By.) ;  Diamine  Fast  YeUow  8  G  (C.) : 

P^^NHC,H4N,C,H,(C0,H)0H 
^"\NHC,H4N,C,H,(C0,H)0H 

p-Aminoacctanilide  is  diazotised  and  combined 
with  salicylic  acid,  the  product  hydrolysed  and 
treated  with  carbonyl  chloride.  The  yellow 
aqueous  solution  gives  a  brown  precipitate 
with  hydrochloric  acid,  and  becomes  rather 
more  orange  with  sodium  hydroxide.  The 
solution  in  sulphuric  acid  is  oranee-red,  giving 
a  bluish- violet  precipitate  on  dilution. 

Liieraiure.—E,  P.  16268  of  1888 ;  D.  R.  P. 
46737,  47902  ;  A.  P.  430536. 

Benzo  Fast  Pink  2  BL  (By.) : 

CO^.H,(SO,H)-N,-C,oH,(SO,H)(OH)NH, 
^"\C.H,(SO,H)N,-CioH4(SO,H)(OH)NH, 

Prepared  from  tetrazotised  di-p-aminodiphenyl- 
carbamidedisulphonic  acid  and  7  -  amino-  a  • 
naphthol-3-sulphonic  acid  (7-acid;  2  mob.)  in 
neutral  or  acid  solution.  The  red  aqueous  solu- 
tion becomes  reddish-violet  with  hydrochloric 
acid  and  yellower  with  sodium  hydroxide.  The 
solution  in  sulphuric  acid  is  blue,  giving  an 
almost  black  precipitate  on  dilution. 

Literalure.—E.  P.  11766  of  1901 ;  D.  R.  P. 
129388,  131613;  F.  P.  311339;  A.  P.  687171; 
Zeitsch.  Farben.-Ind.  1902,  1,  192 ;  Chem.  Zeil. 
1902,  26,  486. 

MilUng  Red  R  (D.) : 

CH  ^.H4N,CioH,(SO,H),-OH 
^^«\C,H4N,CioH4(SO,H),OH 

Prepared  from  tetrazotised  diaminodiphenyl- 
metnane  and  )3-naphthol-3  :  6-disulphonic  acid 
f R-salt;  2  mols.).  The  corresponding  colour 
from  diaminodixylylmethane  is  (annabar  Scarlet 
BF  (B.  K.),  and  that  from  diaminodixylylphenyl- 
methane  is  Cotton  Ponceau  (B.  K.) ;  Cmnabar 
Scarlet  G,  R  (B.  K.).  They  are  all  also  used  for 
the  preparation  of  lakes. 

Literature,— D,  R.  P.  43644. 

Bbmarck  Brown  (most  firmp) ;  Manchester 
Brown ;  Phenylene  Brown ;  Vesuvine ;  Leather 
Brown;  Cinnamon  Brown;  English  Brown: 
Brown  A  (P.) : 

(NH,)AH,-N,-C.H4N,C.H,(NH,), 

Prepared  by  adding  a  solution  of  42*6  kiloe  of 
sodium  nitrite  and  127*6  kilos  of  hydrochloric 
acid    to    a    solution    of    m-phenylenediamine 


478 


AZO.  COLOURraG  BfATTERS. 


propared  by  reducing  250  kilos  of  m-dinitro- 
benzene.  The  commeroial  product  is  the 
hydrochloride.  The  aqueous  solution  ffiyee  a 
brown  j^recipitate  with  sodium  hv£roxide. 
The  solution  in  sulphuric  acid  is  brown,  becoming 
red  on  dilution. 

Literalure.—E,  P.  3307  of  1803 ;  Zeitsch.  f. 
Ghem.  1807,  3,  278;  Ber.  1897,  30,  2111,  2203, 
2899. 

Azo  Alizarine  Bordeaaz  W  (D.  H.) : 

CO,H-C4H,(OH)N,C,H4N,C,oH.(SO,H)OH 

p-Aminoacetanilide  is  diazotised  and^  combined 
with  salicylic  acid,  the  product  fiydrolysed 
and  diazotised  and  combined  with  a-naphthol- 
4-sulphonio  acid.  The  aqueous  solution  is  red, 
and  that  in  sulphuric  acid  is  blue. 

Liierature.—E,  P.  1033  of  1899 ;  D.  R.  P. 
appl.  D.  9290 ;  F.  P.  284776 ;  A.  P.  631089. 

Azo  Alizarine  Blaek  I  (D.  H.).  Prepared  as 
the  preceding,  except^  that  the  end-component 
is  1  :  8-dihydrozynaphthalene-3  :  6-di-(or  4- 
'mono)-Bulphonic  acid.  The  aqueous  solution  is 
violet,  and  that  in  sulphuric  acid  blue. 

LiUralure,'-E.  P.  1033  of  1899 ;  D.  R.  P. 
appl.  D.  9290 ;  F.  P.  284775 ;  A.  P.  640010, 
628721. 

Violet  Blaek  (B.) : 

NH,CioH,N,C,H4N,CioH,(SO,H)-OH 

p-Aminoacetanilide  is  diazotised  and  combined 
with  1  mol.  of  a-naphthol-4-sulphonio  acid. 
The  acetyl-  group  is  then  removed  bv  heating 
with  alkali,  and  the  amino-  compound  is  diazo- 
tised and  combined  with  1  mol.  of  a-naphthyl- 
amine.  Aqueous  solution  brownish-red,  giving 
violet  precipitate  with  mineral  acids  and 
reddish-violet  colouration  with  acetic  acid  or 
with  sodium  hydroxide;  blue  solution  in  sul- 
phuric acid  giving  violet  precipitate  on  dilution. 

LitercUure.—D.  R.  P.  42814. 

Ingnin  Blaek  C  (H.) : 

H80,CioH4(NH^N,C,H40ioH4(80,HXOH)NH, 

f»-Aminoaoetanilide  ia  diazotised  and  combined 
with  a-naphthylamine-6-(or  7)-sulphonio  acid 
(Clove's  acid),  the  product  hydrolysed,  diazo- 
tised, and  combined  with  1  mol.  of  7-amino-a- 
naphthol-3-8ulphonic  acid  (y-acid). 
,  Add  Alizarine  Blaek  SE  (M.);  Palatine 
Chrome  Blaek  F  (B.) : 

HSO,C,H,(OH)(N,CioH,-OH), 

Prepared  from  tetrazotised  2  :  6-diaminophenol- 
4-siuphonic  acid  and  iS-naphthol  (2  mols.). 
Dark-blue  aqueous  solution  ffives  a  red  pre- 
cipitate with  hydrochloric  acia  and  a  sreenish- 
blue  precipitate  with  sodium  hydroxide.  The 
solution  in  sulphuric  acid  is  violet,  giving  a 
red  precipitate  on  dilution. 

Liter(Uure.—E,  P.  18624  of  1900,  16811  and 
2397  of  1901  ;  D.  R.  P.  147880,  160373 ;  F.  P. 
304694,  308688,  310697,  313671 ;  A.  P.  665696, 
677231. 

Add  Alizarine  Blaek  SN  (M.);  Palatine 
Chrome  Blaek  S  (B.).  Similar  to  the  above, 
except  that  1  mol.  of  /3-naphthol  and  1  mol.  of 
)9-naphtiiol-6-sulphonio  acid  are  used  as  com- 
ponents. The  blue  aqueous  solution  gives  a 
red  precipitate  with  hydrochloric  acid,  and 
becomes  violet  with  sodium  hydroxide.  The 
solution  in  sulphuric  acid  is  violet,  giving  a 
reddish-brown  precipitate  on  dilution. 


LOeraifire.'-K  P.  2397  and  16811  of  1901 ; 
D.  R.  P.  148212,  150373 ;  F.  P.  308000,  310697, 
313671 ;  A.  P.  680283,  677227. 

Manehester Brown EE(C.) (Lev.);  Biimank 
Brown  R  (I.)  (By.)  (0.)  (H.)  (Central  I^estnff 
and  Chemical  Co.)  (Ault  and  Wiborg  Co.),  Ao. ; 
Bismarek  Brown  2  R.  eonc.  (T.  M.) ;  Bismarok 
Brown  T  (D.  H.) ;  Vesuvine  B  (B.) ;  Brown  N 
(P.);  Bullalo  Brown  58  (Soh.) : 

(NH,),C,H,-N,-C^,-N,C,H,(NH,), 

Prepared  in  the  same  manner  as  Bismarck 
brown,  but  m-tolylenediamine  is  need  instead 
of  m-phenylenediamine.  The  reddish-brown 
aqueous  solution  becomes  yellowish-brown  witii 
hydrochloric  acid,  and  gives  a  lisht-brown 
precipitate  with  sodium  hydroxide.  The  solu- 
tion m  sulphuric  acid  is  dark  brown,  becoming 
first  red  and  then  brown  on  dilution. 

LitenUure.'-GnGBa,  Ber.  1878,  11,  627. 

Toinylene  Brown  G  (0.)  (By.) : 

HSO,-C,H,<^J>C,H.(NH,), 

Prepared  by  the  action  of  tetrazotised  tolylene- 
diaminesulphonic  acid  (CH,  ?  NH^ :  SO,H  :  NH, 
=  1 : 2  : 4  :  6)  on  1  mol.  of  m-phenylenediamine. 
Solution  in  water  is  brown,  and  in  sulphuric 
acid  brownish-red. 

Literatwe.—E.  P.  17546  of  1892 ;  D.  R.  P. 
65853  ;  A.  P.  616380. 

Toluyiene  Yellow  (0.).  Prepared  from  the 
same  tetrazo-compound  as  the  precedin^r,  and 
2  mols.  of  6-nitro-ff»-phenylenediamine  m  hy- 
drochloric acid  solution.  The  yellowish-brown 
aqueous  solution  eivee  brown  precipitates  with 
hydrochloric  acid  and  sodium  hydroxide. 
The  solution  in  sulphuric  acid  ia  brown. 

Liter€Uure,—E.  P.  1331  of  1896 ;  D.  R.  P. 
86940 ;  A.  P.  568549. 

Toluyiene  Orange  RR  (0.).  Prepared  from 
the  same  tetrazo-compound  as  before,  and 
2  mols.  of  i3-naphthylamine.  The  yellowish- 
red  aqueous  solution  gives  a  brownish-red 
precipitate  with  hydrochloric  acid,  and  a 
yellowish-red  precipitate  with  sodium  hydroxide. 
The  solution  in  sulphuric  acid  is  bluish-grey. . 

Literature.— E.  P.  17546  of  1892 ;  D.  R.  P. 
70147  ;  A.  P.  497032. 

Diamine  Gold  YeUow  (C.) : 

C,H,-0 •C,H4N,-Ci,H4(S0,H),N,C,H40  C A 

Prepared  from  tetrazotised  1 : 5-naphtfiylene- 
diamine-3 : 7-disulphonic  acid  and  phenol  (2 
mols.),  the  product  then  being  ethylated.  The 
yellow  aqueous  solution  eives  a  brownish- 
yellow  precipitate  with  hydrochloric  acid  and 
a  yellow  precipitate  with  sodium  hydroxide. 
The  solution  in  sulphuric  acid  is  reddish-violet, 
becoming  green  ana  then  yellow  on  dilution. 

Literature,— E,  P.  16346  of  1890 ;  D.  R.  P. 
61174  ;  F.  P.  182063,  208526  ;  A.  P.  472121. 

Naphthylene  Violet  (C.) : 
NH,-CioH.-N,CioH4(SO,H),-N,-CioH,NH, 

Prepared  from  the  preceding  tetrazo-  compound 
and  a-naphthylamine  (2  mob.).  The  Bordeaux- 
red  aqueous  solution  gives  a  blue  precipitate 
with  hydrochloric  acid,  and  a  red  predpitate 
with  sodium  hydroxide.  The  solution  in 
sulphuric  acid  is  blue,  and  gives  a  violet  pre- 
cipitate on  dilution.  The  colouring  matter  is 
usually  diazotised  and  developed  on  the  fibre 


AZO-   COLOURING  MATTERS. 


479 


or  treated  on  the  fibre  with  nitrous  acid,  the 
latter  colour  being  known  as  Diamine  Cuteh, 
which  is  a  fast  brown  shade. 

Lileraturc—K  P.  15346  and  16347  of  1890 ; 
D.  R.  P.  62076 ;  F.  P.  208626,  208670 ;  A.  P. 
464666. 

Coomaasle  Navy  Blue  (Lev.) : 

(H80,),C,oH4(OH)N,CioH,(80,H)Nj|OioH,OH 

Prepared  bv  diazotising  1  : 4-naphthylene- 
diamine-2-suIphonio  acid  (only  one  amino- 
group  can  be  diazotised),  combining  with  B- 
naphthol-3  :  6-disulphonic  acid,  diazotising  the 

Sroduct  (the  second  amino-  group  can  now  be 
iazotised),  and  combining  with  /3-naphthol. 
Dark-blue  aqueous  solution  becomes  violet  with 
sodium  hydroxide.  Solution  in  sulphuric  acid 
is  blue-green,  becoming  dark  blue  on  dilution. 

Irfienrfttre.— E.  P.  2946  of  1896 ;  D.  R.  P. 
102160 ;  F.  P.  266862 ;  A.  P.  619194,  634009, 
639748. 

DIp'henyl  Fast  Black^  (G.) : 
jjg^C,H.N,C,oH,(OH)(NHJ-SO,H 

Prepared  from  tetrazotised  p-diaminoditolyl- 
amine  and  1  mol.  of  7-amino-a-naphthol-3- 
snlphonio  acid  (7-acid)  and  1  mol.  of  m-tolylene- 
.diamine.  The  violet-black  aqueous  solution 
gives  with  hydrochloric  acid  a  bluish-black 
precipitate,  and  with  sodium  hydroxide  a  black 
precipitate.  The  solution  in  sulphuric  acid  is 
dark  blue,  and  gives  a  black  precipitate  on 
dilution. 

LOercUvre.-'K  P.  16682  of  1896;  F.  P. 
268621 ;  A.  P.  676904. 

DlantUne  (Claus  A  Co.) ;  St.  Denis  Red  (P.) ; 
RosoFhenine  4  B  (Gl.  Co.) ;  Rosanol  4  B  (K.) ; 
Cotton  Red  8  (B.) : 

^NC,H,N,Ci,H,(80,H)0H 

\nC^,N,C,oH,(SO,H)OH 

Prepared  from  tetrazotised  diaminoazoxytoluene 
and  a-naphthol-4-sulj^honic  acid  (2  mols.). 
The  red  aqueous  solution  nves  red  precipitates 
with  hvdrochloric  add  ana  sodium  hydroxide. 
The  solution  in  sulphuric  acid  is  red,  and  gives 
a  red  precipitate  on  dilution. 

Literature,— E,  P.  9316  and  11976  of  1887, 
6736  of  1890,  19891  of  1892  ;  D.  R.  P.  44046, 
44664;  F./P.  184649;  Compt.rend.  1901,132,986. 

Congo  Orange  6  (A.) : 

0,H4N,-CgH40C,H, 


i. 


!,H,N,C..H«(SO,H),-NH, 

Propared  from  tetrazotised  benzidine  '  and  1 
mdL  of  i8-naphthylamine-3  :  6-disulphonic  acid, 
and  1  mol.  of  phenol,  the  product  being  ethylated. 
The  orange-yellow  aqueous  solution  sives  a 
brown  precipitate  with  hydrochloric  acid.  The 
solution  in  sulphuric  acid  is  blue,  becoming 
reddish- violet  on  dilution,  and  finally  giving  a 
brown  precipitate.  The  corresponding  colounng 
matter irom  tolidine  is  Congo  Orange  R  (A.). 

*  Dlamlm  DtspBlack  (C.)  Is  derived  from  p-diamlno- 
dlphenyUmine ;  Pluto  Blaek  (By.)  also  belongs  to 
the  same  oliiss. 

*  Benzidine  or  p-diaminodlphenyl  Is  praiutred  by 
reducing  nitiobensene  with  zinc-dust  and  alkali  to 
hydrazobenzene  and  converting  this  by  means  of  acids 
Into  benxidine.  The  homologues  of  benzidine  are  pre- 
pared in  a  similar  manner. 


Literature,— E.  P.  17967  of  1889 ;   D.  R.  P. 
62328 ;   F.  P.  160722. 

Pyramidol  Brown  EG  (Farbwerk  Ammen- 
f oort) : 

C,H,-N.C,H,(OH). 


t. 


!^,N,-C,H.(OH), 

Prepared  from  tetrazotised  benzidine  and 
resorcinol  (2  mols.).  The  orange-brown  aqueous 
solution  gives  a  brown  precipitate  with  hydro- 
chloric acid,  and  becomes  Rordeaux-red  with 
sodium  hydroxide.  The  solution  in  sulphuric 
acid  is  reddish- violet,  giving  a  brown  precipitate 
on  dilution.  Cotton  d^ed  red  with  this  colouring 
matter  is  converted  mto  a  deep  brown  when 
treated  with  a  diazo-  compound  on  the  fibre. 

Cbryiamlne  G  (Ry.)  (A.)  (Lev.)  (H.)  (L.) 
(T.  M.)  (K.  S.)(Rarking  Chemicals  Co.)  (Marden, 
Orth,  and  Hastings  Corporation)  (Calco  Chemical 
C!o.) ;  Azldlne  YeUow  6  (C.  J.) ;  Dlroet  YeUow  CG 
(SoL): 

C,H4N,C,H,(0H)(X),H 


i 


.H,N,C,H^OH)<X),H 

Prepared  by  the  action  of  tetrazotised  benzidine 
on  salicylic  acid  (2  mols.)  in  alkaline  solution. 
Used  for  dyeing  cotton  goods  yellow  directly 
from  a  soap- bath.  Aqueous  solution  orange, 
becoming  redder  on  addition  of  sodium  hy- 
droxide; orange  flocoulent  precipitate,  with 
dilute  sulphuric  acid.  Scduble  m  sulphuric  acid, 
with  a  magenta-red  colour,  becoming  orange 
and  predpitatinff  on  dilution.  The  homologue 
from  tetrazoditolyl  is  Chrysamlne  R  (Ry.)  (A.) 
(L.)  (Lev.)  (T.  M.)  (K.  S.). 

Literature.— E.  P.  9162  and  9606  of  1884; 
D.  R.  P.  31668  ;  A.  P.  329638. 

Cresotlne  YeUow  G  (M.)  (O.) : 

C,H4N,C,H,(C0,H)0H 


i 


!.H4N,C,H,(C0,H)0H 

Prepared  from  tetrazotised  benzidine  and 
hydroxytoluic  acid  (OH  :  CH,  :  COaH  =»  1  : 
2 : 6).  Yellow  aqueous  solution  gives  a 
brownish-yellow  precipitate  with  hydrochloric 
acid  and  becomes  yellowish-red  with  sodium 
hydroxide.  Solution  in  sulphuric  acid  is 
reddish-violet,  precipitating  on  dilution.  The 
corresponding  colouring  matter  from  tolidine 
is  Cresotlne  YeUow  R  (0.) ;  Azldlne  YeUow  R 
(C.  J.). 

Literature.— E.   P.    7997   of    1888;    A.    P. 
394841. 

Brliilant  Oiange  G  (A.)  (Ry.) : 
C,H4N,C.H,(C0,H)0H 


i. 


I.H,N,C.H,(SO,H)(OH)NH, 

Prepared  from  tetrazotised  benzidine  and  1  mol. 
each  of  saliovlic  acid  and  aminophenolsulphonic 
acid  m.  Yellowish-brown  aqueous  solution 
gives  a  violet-brown  precipitate  with  hydro- 
chloric acid.  Solution  in  sulphuric  acid  is 
reddish-violet. 

Literature,-!),  R.  P.  78626. 

Orange  TA  (A.)  (Ry.)  (L.) : 

CeH,N,C,oH,(SO,H)NH, 
CeH^N.-CH/OH     • 


480 


AZO-  COLOURING   MATTERS. 


Prepared  from  tetrazotiaed  benzidine  and  1  mol. 
each  of  naphthionic  acid  and  creeol.  Reddish- 
brown  aqueooB  solution  gives  a  violet-blue  pre- 
cipitate with  hydrochloric  acid,  and  becomes 
reader  with  sodium  hvdrozide.  Solution  in 
sulphuric  acid  is  blue,  giving  a  blue  precipitate 
on  dilution. 

Benzo  Orange  R  (By.)  (K.  S.)  (Harden,  Orth, 
and  Hastings  (Corporation) : 

C,H4N,C,H,(C0,H)0H 


i. 


J,H4-N,-CioH,(SO,H)NH, 

Prepared  from  tetrazotised  benzidine  and  1  mol.« 
each  of  salicylic  acid  and  naphthionic  acid. 
The  orange-yellow  aqueous  solution  becomes 
reddish-violet  with  hydrochloric  acid,  and  ffivee 
a  reddish-yellow  precipitate  with  sodium 
hydroxide.  Solution  in  sulphuric  acid  is 
violet- blue,  giving  a  greyish- violet  precipitate 
on  dilution. 

Literaiure,—^.  P.  2213  of  1886;  D.  R.  P. 
44797  ;  A.  P.  447303. 

Bordeaux  GOV  (A.) ;  Bordeaux  extra  (By.) ; 
Bordeaux  BL  extra  (T.  M.) ;  Azidine  Violet  B 
(0.  J.) ;  New  Bordeaux  L  (B.) : 

0,H4-N,-OioH,(SO,H)OH 


i. 


J,H4-N,-CioH,(SO,H)OH 

Prepared  from  tetrazotised  benzidine  and  fi- 
naphthol-8-sulphonic  acid  (2  mole.).  Bordeaux- 
red  solution  in  water,  and  violet  in  sulphuric 
acid. 

LUeraiure.—E.  P.  8406  of  1884 ;  D.  R.  P. 
30077. 

Diamine  Fast  Red  F  (C);  DIanol  Fast 
Red  F  (Lev.) ;  Azidine  Fast  Red  F  (0.  J.) ; 
Oxamine  Vnsi  Red  F  (B.) ;  Maphthamlne  Red 
H(K.);  Dianll  Fast  Red  PH  (M.) ;  Benzo  Fast 
Red  FC  (By.);  Columbia  FM  Red  F  (A.); 
Triazol  Fast  Red  G  (0.) ;  Diphenyl  Fast  Red 
(G.);  Hessian  Fast  Red  F  (L.);  Benzamine 
Ftol  Red  F  (D.) ;  Dlreet  Fast  Red  F  (Sch.)  (I.) : 

C,H4-N,-OioH4(SO,H)(OH)-NH, 


A 


),H4N,C.H,(C0tH)0H 

Prepared  from  tetrazotised  benzidine  and  1  mol. 
of  7-amino-a-naphthol-3-sulphonic  acid  (7-acid) 
combined  in  acia  solution,->and  1  mol.  of  salicylic 
acid.  Red  aqueous  solution  fives  a  brown 
precipitate  with  hydrochloric  acid.  The  solution 
in  smphuric  acid  is  reddish-blue,  and  gives  a 
brown  precipitate  on  dilution. 

Liierature,—E,  P.  16699  of  1889 ;  D.  R.  P. 
67867  ;  P.  P.  201770. 

Crumpsall  Direet  Fast  Red  R  (Lev.) : 

C,H4N,C,oH4(SO,H),OH 


i. 


(L);    Direct  Brown  8  RB  (Sch.);    Oxamine 
Brown  R  (B.) : 

C,H4N,CoH,(00,H)OH 


i 


l,H4-N,C,oH4(SO,H)(OH)^NH, 
Prepared  from  tetrazotised  benzidine  and  1  mol. 
each  of  salicylic  acid  and  7-amino-a-naphthol-3- 
sulphonio  acid  (7-acid) ;  the  latter  being 
combined  in  alkaline  solution.  The  reddish- 
brown  aqueous  solution  eivee  a  brown  precipitate 
with  hydrochloric  acid  and  a  reddish-brown 
precipitate  with  sodium  hydroxide.  The  solu- 
tion in  sulphuric  acid  is  violet,  changing  tc 
brown  on  dilution. 

Literature,— I>.  R.  P.  67867 ;  F.  P.  201770. 

Diphenyl  Brown  BN  (G.) : 


i. 


5.H4N,C,H,(CO,H)OH 

Prepared  from  tetrazotised  benzidine  and  1  mol. 
each  of  i3-naphthol-3  :  6-disulphonic  acid  (R-salt) 
and  salicylic  acid. 

Literature.— E,  P.  2213  of  1886 ;    D.  R.  P. 
44797  ;  A.  P.  447303. 

Diamine  Brown  H  (G.) ;  Chlorazol  Brown  H 
(H.) ;  Renol  Brown  MB,  eone.  (T.  M.) ;  Azidine 
Brown  M  (C.  J.) ;  Naphthamlne  Brown  H  (K.) ; 
Cnunpsall  Direct  Fast  Brown  B  (Lev.) ;  Dianll 
Brown  MH  (M.);  Benzamine  Brown  M  {D.)f 
Direct  Dark  Brown  M  (L.);  Direct  Brown  M 


,H4-N,CxoH4(SO,H)(OH)N(CH,), 

Prepared  from  tetrazotised  benzidine  and  1  moL 
each  of  salicylic  acid  and  7-dimethylamino-a- 
naphthol-3-sulphomc  acid.  [The  corresponding 
colouring  matter  from  the  monomethyiamino- 
compound  is  Diphenyl  Brown  RN  (G.).]  The 
dark-brown  solution  gives  a  red  precipitate  with 
liydrochloric  acid.  The  solution  in  sulphuric 
acid  is  blmsh-violet,  giving  a  red  j^recipitate 
on  dilution.  When  toudine  is  used  mst^ead  of 
benzidine,  Diphenyl  Brown  8  6N  (G.)  ia  obtained. 

Literature.— E.  P.  2771  of  1896;   D.  R.  P. 
103149 :  F.  P.  260697 ;  A.  P.  667413. 

Diamine  Brown  B  (C.) ;  CnunpsaU  Brown  M 
(Lev.) : 

C,H4N,-C.H,(CX),H)-0H 


i. 


l,H4N,-CioH4(SO,H)(OH)NHC,H, 

Prepared  from  tetrazotised  benzidine  and  1  moL 
each  of  siUicylic  acid  and '  7-phenylainino-a- 
naphthol-3^ulphonic  acid.  The  dark-brown 
aqueous  solution  gives  a  Bordeaux-red  pre- 
cipitate with  hydrochloric  acid,  and  becomes 
redder  with  sodium  hydroxide.  The  solution 
in  sulphuric  add  is  violet,  giving  a  brown  pre- 
cipitate on  dilution. 
Oxamine  Maroon  (B.) : 

C,H4-N,-C,H,(C0,H)-0H 


k 


l,H4-N,-CipH4(S0,H)(0H)-NH, 

Prepared  by  combining  tetrazotised  benzidine 
with  1  mol.  of  6-amino-a-naphthol-3-8ulphonic 
acid  in  alkaline  solution,  ana  adding  1  moL  of 
salicylic  acid  to  the  product.  The  ruby-red 
aqueous  solution  does  not  change  with  acids  or 
alkalis.  The  solution  in  sulphuric  acid  is  dark 
violet,  changing  to  wine-red  on  dilution. 

LitenUure.—E.  P.  2370  of  1893 ;  D.  R.  P. 
82672  ;  F.  P.  229263  ;  A.  P.  668344. 

Oxamine  Red  (B.).  Isomeric  with  the  pre- 
ceding. 6-Amino-a-naphthol-3-sulphonic  acid 
is  vaSd.  inst^ead  of  the  6-amino-  acid.  The  red 
aqueous  solution  is  not  changed  by  hydrochloric 
acid,  but  becomes  slighUy  more  violet  with 
sodium  hydroxide.  The  solution  in  sulphuric 
acid  is  blue,  changing  to  wine-red  on  dilution. 

Literature.— E.  P.  2614  of  1893 ;  D.  U.  P. 
93276  ;  F.  P.  227892  ;  A.  P.  666359. 

Wool  Red  6  (B.) : 

0,H4-N,-C.H^S0,H)0H 


i 


.H4N,C,oH4(SO,H)(OH)NH, 


AZO-  OOLOURINQ   MATTERa 


481 


Prepared  from  tetrazotised  bonzidine  and  1  mol. 
eaca  of  phenol-o-snlphonic  acid  and  7-ammo-a- 
naphthoI-3-8nlplionio  aoid  (y-acid),  the  latter 
being  combined  in  acid  solution.  The  red 
aqueouB  solution  gives  a  brown  precipitate  with 
hydxochlorio  acid,  and  becomes  darlk-red  with 
sodium  hydroxide.  Solution  in  sulphuric  acid 
is  yiolet,  giving  a  brown  precimtate  on  dilution. 

LUeratwrc—D,  B.  P.  appl.  B.  29649  of  1901 ; 
F.  P.  313633. 

Dlamlno  Seartot  B  (C.) ;  Dlanll  Ponoeaa  G 
(M.)  1 : 


i. 


5AN,-C,oH4(80,H),NH, 

Tetrazotised  benzidine  is  combined  first  with  I 
mol.  of  iB-naphthylamine-6  :  S-disulphonio  add, 
then  with  1  mol.  of  phenol  and  the  product  is 
ethylated.  The  red  aqueous  solution  becomes 
browmsh-red  with  hydrochloric  acid.  The 
solution  in  sulphuric  acid  is  violet,  becoming 
brown  on  dilution. 

Literature.— E.  P.  12560  of  1889 ;  D.  R.  P. 
64084 ;  F.  P.  200162 ;  A.  P.  426346. 

Pynmlne  Onmge  2  R  (B.) : 

C,H4-N,CioH4(S(^),NH, 


k 


Prepared  from  tetrazotised  benzidine  and  1  mol. 
eaon  of  /3-naphthylamine-3 :  disulphonio  acid 
and  p-niixo-m-phenylenediamine.  The  yellow 
aqueous  solution  is  not  changed  by  acids  or 
alkalis.  The  solution  in  sulphuric  acid  is  blue, 
becoming  yeUowish-red  on  duution. 

Literature.— E,  P.  6827  of  1899 ;   D.  R.  P. 
107731 ;  F.  P.  280914 ;  A.  P.  631611. 

Pynmlne  Orange  3  Q  (B.): 

C,H4N,-C,H,(NH,),-N0, 


k 


J,H,N,C,H(SO,H),(NH,), 

Prepared  from  tetrazotised  benzidine  and  1  mol. 
each  of  ifi-phenylenediamine-4 :  6-diBulphonic 
acid  and  p-nitro-m-phenylmediamine.  The 
vellowish-red  aqueous  solution  is  not  changed 
by  acids  or  alkalis.  The  solution  in  sulphuric 
add  is  yellpwish-red,  becoming  brownish- 
yellow  on  dilution. 

Literature.— K  P.  18606  of  1898 ;  D.  R.  P. 
106349 ;  F.  P.  280914 ;  A.  P.  631610. 

Congo  Rod  (Lev.)  (A.)  (By!)  (L.)  (K.  S.) 
(B.  K.)  (Sch.)  (Harden,  Orth,  and  Hastings  Cor- 
poration);  Congo  Red  R  (H.);  Cosmbs  Red 
(B.) ;  Cotton  Red  eone.  (T.  M.) ;  Cotton  Red  C 
(I.)  (P.) ;  Cotton  Red  B  (K.) ;  DIanU  Red  R 
(M.);  Cotton  Red  4  B  (0.) ;  Direet  Red  C  (Farb- 
werk  Ammersfoort) : 

C,H4N,CxoH,(80,H)NH, 


k 


J,H4-N,-CioH,(SO,H)NH, 

Prepared  by  the  action  of  tetrazotised  benzidine 
on  naphthionio  add  (2  mols.).  It  can  also  be 
obtained  by  ozidisinff  benzeneazonaphthionic 
add  with  manganese  dioxide  in  sulphuric  acid 
solution  (£.  P.  6697  of  1896 ;  D.  R.  P.  84893  ; 
F.  P.  248210).  The  red  aaueous  solution 
becomes  blue  on  addition  of  dilute  acids; 
substance  dissolves  in  sulphuric  add  wiUi  a 

^  ,  *  DIaiiiine  esarisi  S  B(C.) ;  Dlanll  Poncsau  S  R  (M.) 
baloDgg  to  the  same  group,  but  li  bluer. 

Vou  J.—T. 


slaty  blue,  giving  a  bluish  predpitate  on  dilu- 
tion. 

Literature.— E.  P.  4416  of  1884 ;  D.  R.  P. 
28763 ;  F.  P.  160722 ;  Ber.  1886,  19,  1719. 

Dlazo  Blaek  B  (Bv.).  Isomeric  with  the 
preceding.  Prepared  from  tetrazotised  benzi- 
dine and  a-naphthylamine-6-sulphonic  acid 
(L-acid ;  2  mols.).  The  violet  aqueous  solution 
becomes  blue  with  hydrochloric  acid,  and  gives 
a  blue  predpitate  with  sodium  hydroxide. 
The  solution  in  sulphuric  acid  is  blue,  remaining 
blue  on  dilution.  The  colouring  matter  is 
generally  diazotised  and  developed  on  the  fibre. 

Congo  Rnbine  (A.)  (Lev.)  (By.)  (L.)  (B.  K.) ; 
Azidlne  Bordeaux  (G.  J.);  Congo  Rnbine  A 
(K.  S.) ;  Congo  Rnbine  B  (K.) ;  Cotton  Rnbine 
(B.);  Renol  Rnbine,  extra  (T.  M.):  Direet 
Crimson  B  (Sch.) : 

C,H4N,CioH,(SO,H)NH, 


i 


!,H,N,CioH5(SO,H)OH 

Prepared  from  tetrazotised  benzidine  and  1  mol. 
each  of  i3-naphthol-8-sulphemc  acid  and  naph- 
thionic  acid.  The  cherry-red  aqueous  solution 
gives  a  blue  precipitate  with  hydrochloric  acid 
and  a  violet-red  one  with  socuum  hydroxide. 
The  solution  in  sulphuric  acid  is  blue,  giving  a 
blue  precipitate  on  dilution. 

Literature.— D.  R.  P.  62669. 

Congo  Corinth  (A.)  (By.)  (L.)  (Lev.)  (K.  S.) 
(B.  K.) ;  Cotton  Corinth  G  (B.)  (O.) ;  Dianll 
Bordeaux  G  (M.);  Renol  Corinth  G  (T.  M.); 
Buffalo  Garnet  R  (Sch.) : 

C.H4N,C,»H5(SO,H)OH 


k 


l,H4N,C,oH,(80,H)NH, 

Prepared  from  tetrazotised  benzidine,  a-naph- 
thvIamine-4-sulphonio  acid  and  a-naphthoI-4- 
sulphonio  add.  Aqueous  solution  red;  violet 
precipitate  with  hydrochloric  acid  and  colouration 
with  acetic  acid.  Solution  in  sulphuric  add 
blue,  giving  violet  precipitate  on  dilution. 

Literature.— E.  P.  16296  of  1886,  2213  of 
1886 ;  D.  R.  P.  39096 ;  F.  P.  160722,  163172  ; 
A.  P.  344971,  368866. 

Brilliant  Congo  G  (A.)  (L.) : 

C,H4N,-CioH4(SO  JI),NH,  • 


k 


;H4-N,-CioH,(SO,H)-NH, 

From  tetrazotised  benzidine,  iS-naphthylamine- 
3  :  6-disulphonic  acid  and  i3-naphthylamine-6- 
sulphonic  acid  (Bronner's).  Aqueous  solution 
gives  a  brownish-violet  precipitate  with  hydro- 
chloric  add.  Solution  m  sulphuric  add  blue, 
giving  violet  precipitate  on  dilution. 

L7teraiure.—E.  P.  6687  of  1887 ;  B.  R.  P. 
41096 ;  F.  P.  160722. 

HeUotrope  2  B  (A.)  (By.)  (L.) : 

C,H4N,CioH,(SO,H)OH 


i 


!,H.N,-CioH4(SO,H),OH 

Prepared  from  tetrazotised  benzidine  and  1  moL 
each  of  a-naphthol-4  :  8-  (or  3  :  8-)  disulphonic 
acid  and  /3-naphthol-8-8ulphonio  add.  Reddish- 
violet  aqueous  solution  gives  a  bluish-violet 
predpitete  with  hydrochloric  add,  and  becomes 
redder  with  sodium  hydroxide.  Solution  in 
sulphuric  add  is  blue,  oecomii^  reddish-violet 
on  dilution,  and  finally  giving  a  violet  precipitate. 

2  X 


482 


AZO-  COLOURING  MATTERS. 


LUeraiwre.—E,  P.  1346  of  1888 ;  D.  R.  P. 
45342. 

Trisulphone  Violet  B  (K.  S.) ;  Trisulphone 
Blue  B  (K.  S.) ;  Trisulphone  Blue  B  (K.  S.) : 

CeH4N,CioH,(SO,H),OH 

C^^N.-CioH.OH 

The  first-named  (for  which  the  formula  is  given) 
is  prepared  from  tetrazotised  benzidine  and 
1  mol.  each  of  a-naphthol-3  :  6  :  8-tri8ulphonic 
acid  and  ^-naphthoi.  The  second  and  last 
colonring  matters  are  prepared  from  tetrazotised 
tolidine  and  dianisidine  respectively  instead  of 
benzidine.  The  solutions  in  water  are  violet 
to  blue,  and  give  bluish-violet  to  blue  precipi- 
tates with  hydrochloric  acid.  With  sodium 
hydroxide  the  aqueous  solutions  become  reddish- 
violet.  The  solutions  in  sulphuric  acid  are 
ffreenish-blue»  giving  violet  precipitates  on 
dilution. 

Literaiure.—E,  P.  4703  of  1897;  P.  P. 
264279  ;  A.  P.  684981. 

Chleago  Blue  4  R  (A.) ;  Benzo  Blue  4  R  (By.) ; 
Diamine  Blue  C  4  R  (C.) : 

C.H4-N,-CioH5(OH)SO,H 

C,H4-N,CioH4(OH)(NH,)SO,H 

Prepared  from  benzidine,  and  1  mol.  each  of 
1:8-  aminonaphthol  -  4  -  sulphonic  acid  and 
/9-naphthol-8-sulphonic  acid.  Violet-blue  aque- 
ous solution  becomes  blue  with  hydrochloric 
add,  and  reddish-violet  with  sodium  hydroxide. 
Solution  in  sulphuric  acid  is  blue,  giving  a 
violet  precipitate  on  dilution. 

Columbia  Blue  R  (A.) ;  Benxo  Red  Blue  R 
(By.);  Diamine  Blue  LR  (C).  a-Naphthol- 
3 : 8-disulphonio  acid  is  used  instead  of  iS- 
naphthol-8-sul^honio  acid  in  the  preceding  dye. 
The  blue  aqueous  solution  gives  a  blue  precipi- 
tate with  hydrochloiio  acid,  and  is  unchanjged  by 
sodium  hydroxide.  Solution  in  sulphuric  acid 
is  blue,  giving  a  violet  precipitate  on  dilution. 

Diamine  Violet  N  (C.) ;  Chloracol  Violet  B 
(H.);  Dianol  Violet  N  (Lev.);  Azidine  Violet  DV 
(C.  J.);  Maphthamine  Violet  N  (K.);  DianU 
Violet  H  (M.) ;  Direct  Violet  R  (Sch.) ;  Benzo 
fait  Violet  NC  (By.) : 

C,H4N,-CioH4(SO,H)(OH)NH, 

I 
C,H4N,CioH4(SO,H)(OH)NH, 

Prepared  by  the  action  of  tetrazotised  benzidine 
on  2  mols.  of  7-amino-a-naphthol-3-sulphonic 
acid  (7-acid)  in  acid  solution.  The  reddish- 
violet  aqueous  solution  ^ives  a  violet-black 
precipitate  with  hydrochlonc  acid.  The  solution 
m  sulphuric  acid  is  greenish-blue,  giving  a 
reddish-violet  precipitate  on  dilution. 

LUeraiure,—E,  P.  16699  of  1889 ;  D.  B.  P. 
W648 ;  P.  P.  201770. 

Diamine  Black  RO  (C.) ;  Maphthamine  Blaeli[ 
BVE  (K.) ;  Dianol  BiaelK  RO  (Lev.) ;  Oxamlne 
Black  2  R  (B.) ;  Melantherine  RO  (I.).  Isomeric 
with  the  preceding.  The  combination  is  effected 
in  alkidine  solution  whereby  the  azo-  group 
enters  the  2-  position  with  respect  to  the  hyc&oxy- 
group,  whereas  in  the  preceding  case  the  azo- 
group  enters  the  8-  position  (ortho  to  the 
amino-  group).  The  violet-black  aqueous  solu- 
tion gives  a  bine  precipitate  with  hydrochloric 
aoldf  and  becomes  violet  with  sodium  hydroxide. 


The  solution  in  sulphuric  acid  is  blue,  giving 
a  reddish-blue  precipitate  on  dilution. 
'  Literature. — ^As  abova 
Maphthamine  Black  RE  (K.) : 

C.H4N,CioH«(SO,H)(OH)NH, 

C,H4N,OioH4(SO,H)(OH)NH, 

Prepared  from  tetrazotised  benzidine  and  2 
mots,  of  1 :  8-aminonaphthol-6-8ulphonic  acid. 

Uteraiure.—E,  P.  615  of  1894;  D.  R.  P. 
appl.  K.  11223  ;  A.  P.  563386. 

Benzo  Violet  R  (By.) : 

C,H4N,CioH,(SO,H)OH 


i. 


eH4-N,-C,oH4(SO,H),OH 

Prepared  from  tetrazotised  benzidine  and  1  mol. 
each  of  a-naphthol-4-sulphonic  acid  and  a-naph- 
thol-3 :  6-disulphonic  acid.  The  reddish- violet 
aqueous  solution  gives  a  soluble  violet  precipi- 
tate with  hydrocmorio  acid,  and  becomes  red 
with  sodium  hydroxide.  The  solution  in 
sulphuric  acid  is  violet,  giving  a  violet  precipitate 
on  dilution. 

Maphthylamiiy  Diazo  Black  (K.) : 

C,H4-N,-0,  oH4(SO  ,H)(OH)  NH, 

C,H,-N,-OioH,(SO,H),(OH)NH, 

Prepared  from  tetrazotised  and  benzidine  1  mol. 
eeMD.  of  8-amino-a-naphthol-3 : 5-disulphonio 
acid  (K-  acid),  and  7-amino-a-naphthot3-sul- 
phonio  acid  (7-aoid). 

Literature,— E.  P.  515  of  1894;  D.  R.  P. 
99164 ;  A.  P.  563386. 

Diamine  Brown  V  (0.) : 

CeH4NaCioH4(SO,H)(OH)-NH, 


k 


!,H,N,-C.H,(NH,), 

Prepared  from  tetrazotised  benzidine  and  1  mol. 
eacfi  of  7-amino-a-naphthol-3-sulphonic  acid 
(7-acid)  and  m-phenylenediamine.  Brown-red 
aqueous  solution  gives  a  chocolate-brown  pre- 
cipitate with  hydrochloric  acid,  and  pnrpush- 
brown  precipitate  with  sodium  hydroxide. 
Solution  in  sulphuric  acid  is  bluish-violet, 
giving  a  purplish- brown  precipitate  on  dilution. 

L^terature^—E.  P.  16699  of  1889 ;  D.  R.  P. 
57857  ;  F.  P.  201770. 

Dlanil  Garnet  B  (M.);  Benzo  Fast  Red 
9  BL  (By.) : 

0,H4N,CxoH4(SO,H)(OH)NH, 


i. 


!.H,N,-CioH4(SO,H),-NH, 

Prepared  from  tetrazotised  benzidine  and  i  moL 
each  of  y-  acid  and  /B-naphthylamine-3  :  6-disul- 
phonic acid.  Bordeaux-red  aqueous  solution 
gives  a  blackish-blue  precipitate  with  hydro- 
chloric acid.    Solution  m  sulphuric  acid  is  blue. 

LOero/ure.— D.  B.  P.  190694. 

Zambesi  Brown  G,  2  O  (A.) : 

O.H4N,-CioH4(NH,),-80,H 


k 


!«H4-N,CioH4(SO,H)(OH)NH, 

Prepared  from  tetrazotised  benzidine  and  1  moL 
each  of  y-  acid  and  2 : 7-naphthylenediamine- 
sulphonio  acid.  Cotton  is  dyed  corinth  brown 
(G)  or  violet  (2  G). 

Literature,--!).  R.  P.  appl.  A.  3775. 


AZO-  COLOURING  MATTERS. 


483 


I 


Diamine  BUok  BH  (C);  Dianol  Blue  BH 
(Lev.) ;  Diaio  Black  BHN  (B}\) ;  Renolamlne 
Blaek  BH  (T.  M.) ;  Azidlne  Blaek  BHM  (0.  J.) ; 
Ingrain  Blaek  2  B  (H.) ;  Naphthamlne  Blaek  CE 
(K.) ;  Dlanil  Blaek  £S  (M.) ;  Melantherine  BH 
(I.);  Direet  Blaek  HB  (L.);  Diazlne  Blaek 
BH  extra  (Sch.) ;  Oxamine  Blaek  BHN  (B.) ; 
Direct  Blaek  BD  (P.) : 

C,H4N,CioH4(SO,H)(OH)-NH, 

C,H4-N,CioH,(SO,H),(OH)NH, 

Prepared  from  tetrazotised  benzidine  and  1  mol. 
each  of  7-amino-a-naphthol-3-8ulphonio  acid 
and  8-amino-a-naphthol-3  :  6-diBalphonio  acid 
(H-acid).  The  reddish-blue  aqueous  solution 
becomes  violet  with  hydrocUorio  acid  and 
reddish-violet  with  sodium  hydroxide.  The 
solution  in  sulphuric  acid  is  blue,  giving  a 
violet  precipitate  on  dilution. 

Literature.— E,  P.  1742  and  6972  of  1891 ; 
D.  R.  P.  68462 ;  F.  P.  233032. 

Benzo  Cyanine  R  (By.) ;  Diamine  Cyanlne  R 
(C.) ;  Congo  Cyanlne  R  (A.).  Prepared  as  the 
preceding,  except  that  1 : 8-aminonaphthol-4- 
sulphonio  acid  is  used  instead  of  7-acid.  The 
solution  in  water  or  sulphuric  acid  is  blue. 
The  oonespondinff  B  marKs  are  prepared  from 
tolidine,  and  the  8  B  from  dianisidine. 

Literature.— D.  R.  P.  appl.  F.  6667 ;  A.  P. 
533508,  578432. 

examine  Violet  (B.) ;  Chloraiol  Violet  R  (H.) ; 
Naphthamlne  Violet  BE  (K.) ;  Dlanil  Violet  BE 
(M.);  Oxydiamine Violet BF(C.);  BenxoVloletO 

(By.);  Diieet  violet  0  (L) : 

CA-N,CioH4(80,H)(OH)NH, 


(I 


!^4-N,-CioH4(SO,H)(OH)NH, 

Prepared  from  tetrazotised  benzidine  and  6- 
amino-a-naphthol-3-sulphonic  acid  (2  mols.). 
The  combination  is  effected  in  alkaline  solution. 
The  reddish-violet  aqueous  solution  gives  a 
violet  precipitate  with  acids  or  alkalis.  The 
solution  in  sulphuric  acid  is  blue,  giving  a 
violet  precipitate  on  dilution. 

Literature.— E.  P.  2614  of  1893 ;  D.  R.  P. 
75469 ;  F.  P.  227892  ;  A.  P.  521096. 

Diamine  Bine  BB  (C.)  (Central  Dyestuff  and 
Chemical  Co.) ;  Benxo  Bine  BB  (By.)  (Lev.) ; 
Congo  Bine  2  BX  (A.) ;  Direet  Bine  V  (P.) ; 
Axidine  Blue  2  B  (C.  J.) ;  Chlorazol  Blue  RB 
(H.) ;  Naphthamine  Blue  2  BX  (K.) ;  Dlanil 
Blue  HZG  (M.);  Benzamine  Blue  2  B  (D.); 
Niagara  Blue  2  B  (Sch.) : 

CANi'OioH,(SO,H),(OH)NH, 


i 


J,H4N,CioH,(SO,H),(OH)NH, 

Prepared  by  combining  tetrazotised  benzidine 
in  alkaline  solution  with  8-amino-a-naphthol- 
3 :  6-disulphonic  acid  (H-acid ;  2  mols.).  The 
reddish-bfue  aqueous  solution  is  unchanged  by 
adds  or  alkalis.  The  solution  in  sulphuric  acid 
is  blne»  becoming  violet  on  dilution. 

Literature.-^.  P.  13443  of  1890.  1742  of 
1891 ;  D.  R.  P.  74593;  F.  P.  210033;  A.  P. 
464135. 

Dipiienyl  Bine  Blaek  (GJ : 

C,H4N,C,  pH,(SO,H),(OH)-NH, 

CAN,CioH4(80,H)(OH)NHC,H, 


Prepared  from  tetrazotised  benzidine  and  1  mol. 
each  of  H-acid  and  7-ethylamino-a-naphthol-3- 
sulphonic  acid.  The  dark-blue  aqueous  solution 
gives  a  violet  precipitate  with  hydrochloric  acid, 
and  becomes  dark  violet  with  sodium  hydroxide. 
The  solution  in  sulphuric  acid  is  blue,  giving  a 
dark  violet  precipitate  on  dilution. 

Literature.— E.  P.  2771  of  1896 ;  D.  R.  P. 
103149  ;  F.  P.  250697  ;  A.  P.  556164,  567413. 

Naphthamlne  Blues  2B,  8B,  and  5B  (K.). 
These  are  derived  from  tetrazotised  benzidine, 
toUdine,  &o.,  and  8-amino-o-naphthol-3  : 5-diBlil- 
phonio  acid  (K-acid).  The  blue  aqueous  solution 
gives  a  blue  precipitate  with  hychrochloric  acid, 
and  turns  reddiBh- violet  with  sodium  hydroxide. 
The  solution  in  sulphuric  acid  is  bluish-green. 

Literature.— E.  P.  515  of  1894;  D.  R.  P. 
99164 ;  A.  P.  563385,  563386. 

Direet  Gray  R  (L) : 

C,H4N,CioH,(OH),(CO,H)SO,H 


k 


•H4-N,CioH,(OH),(CO,H)-SO,H 

Prepared  from  tetrazotised  benzidine  and 
1  :  7-dihydroxy  •  6  •  carboxynaphthalene-3-sul- 
phonic  acid  (2  mols.).  Tne  violet  aqueous 
solution  gives  a  bluish-grey  precipitate  with 
hydrochloric  acid  and  becomes  dull  violet-red 
with  sodium  hydroxide.  The  solution  in  sul- 
phuric acid  is  blue,  giving  a  bluish-grey  precipi- 
tate on  dilution.  The  corresponding  colour 
from  tolidine  is  Direet  Gray  R. 

Literature.— E.  P.  14253  of  1892 ;   D.  R.  P 
75258  ;  F.  P.  220468 ;  A.  P.  493564. 

Direet  Violet  R  (L): 
^C.H4N,CioH,(OH),(00,H)SO,H 

(!jA-N,C,H.(NH,),       . 

Prepared  from  tetrazotised  benzidine  and  1  mol. 
each  of  the  above  dihydroxycarboxynaphthalene- 
sulphonic  acid  and  m-tolylenediamine.  The 
solution  in  water  is  violet,  and  in  sulphuric  acid 
blue. 

Literature.— A.  P.  527070. 

Dianol  Red  2  B  (Lev.) ;  Aiidine  Purporlne 
10  B  (C.  J.) : 

CAC1N,CioH,(SO,H)NH, 


i. 


!,H,aN,CioH,(SO,H)NH, 

Prepai«d  from  tetrazotised  dichlorobenzidine 
(NH,  :  Cl=4 :  3),  and  naphthionio  acid  (2  mols.). 
The  red  aqueous  solution  becomes  violet  with 
hydrochloric  acid.  The  solution  in  sulphuric 
acid  is  blue,  changing  to  violet  on  dilution. 

Literature.— E.  P.  25725  of  1896 ;  D.  R.  P. 
94410 ;  F.  P.  265135 ;  A.  P.  625174,  640743. 

Dianol  Brilliant  Red  extra  (Lev.) ;  Toluylene 
Red  (O.);  Chlorantlne  Red  8  B  (L);  Aeeto- 
purpurine  8  B  (A.) ;  Diphenyl  Red  8  B  (G.) ; 
Aiidine  Brilliant  Red  8  B  (C.  J.);  Oxamlne 
Seariet  B  (B.) : 

C,H,aN,-CioH4(SOtH),-NH, 


k 


l,H,a-N,-CioH4(SO,H),-NH, 

Prepared  from  tetrazotised  dichlorobenzidine 
ana  /3-naphthvlamine-3 : 0-disulphonic  acid. 
The  blnish-red  aqueous  solution  becomes 
sliffhtly  darker  with  hydrochloric  acid.  The 
solution  in  sulphuric  acid  is  blue,  becoming  red 
on  dilution. 


484 


AZO-  COLOURING  MATTERS. 


i. 


!.H,-N,CxoH.(80,H),NH, 

Prepared  from  tetraEotifled  benzidinemono- 
Bulphonio  aoid  and  iS-naphthylamine-S  :  6-diBul- 
phonic  add  (2  mols.).  it  is  a  brown  powder, 
soluble  in  water,  and  the  solution  gi^es  a  blue 


LUmUure,—E,  P.  26726  of  1896 ;  D.  R.  P. 
94410,  97101 ;  F.  P.  266136 ;  A.  P.  626174, 
640743. 

AnOmeene  Red  (L)  (By.) 

NO,C^,-N,C^,(CO,H)OH 

C.H4N,0,oH,(SO,H)OH 

Prepared  by  oombinine  tetrazotised  nitro- 
benzidine  first  with  1  m(M.  of  salioylio  acid  and 
then  with  1  mol.  of  a-naphthol-4-smphonio  acid. 
(The  same  colour  is  not  produced  by  inverting 
the  order  of  combination.)  The  red  aqueous 
solution  gives  a  red  precipitate  with  hydrochloric 
aoid.  The  solution  in  smphuric  acid  is  carmine- 
red,  giving  a  brownish-red  precipitate  on 
dilution. 

LUeraturf.—E.  P.  13476  of  1892 ;  D.  R.  P. 
72867  ;  F.  P.  223176  ;  A.  P.  493683. 

Salieine  Red  G  (K.).  Prepared  from  tetra- 
zotised nitrobenzidine  and  1  mol.  each  of  salicylic 
acid  and  iS-naphthol,  the  product  being  sul- 
phonated. 

LUeraiure.'-K  P.  9464  of  1896 ;  D.  R.  P. 
87484. 

Salieine  Yellow  G  (K.).  Prepared  from 
tetrazotised  nitrobenzidine  and  salicylic  add 
(2  mols.),  the  product  bein^  sulphonatod.  The 
orange  aqueous  solution  is  precipitated  with 
hydrochloric  acid  and  becomes  reddish-brown 
with  sodium  hydroxide.  The  solution  in  sul- 
phuric acid  is  orange-yellow,  and  gives  a  brown 
preci]^itate  on  dilution. 

IMenUure, — ^As  above,  and  Chem.  Ind.  1896, 
19,  662. 

Sttlphone  Aznrine  (By.)  (A.)  (L.)  (Lev.) : 

<C,H,(SO,H)N,-CioH,NHC^, 
I 
C.H,(SO,H)N,CioH,NHC,H, 

Prepared  from  tetrazotised  benzidinesulphone- 
diimphonio  acid  and  phenyl-a-naphthylamine 
(2  mols.).    The  blue  aqueous  solution  gives  blue 

Precipitates  with  hydrochloric  acid  and  sodium 
ydrozide.  The  solution  in  sulphuric  acid  is 
violet,  giving  a  blackish-violet  precipitate  on 
dilution. 

Literature,— E.  P.  1074  and  1099  of  1884 ; 
D.  R.  P.  27964, 33088 ;  A.  P.  432989 ;  Ber.  1889, 
22,2469. 

Pynunlne  Orange  R  (B.) : 

SO,HC,H,N,C,H,(NH,),-NO, 

80^C,H,N,C,H,(NH,),N0, 

Prepared  from  tetrazotised  benzidinedisulphonic 
acid  and  6-nitro-ffi-phenylenediamine  (2  mols.). 
The  orange-red  aqueous  solution  sives  a  yellow- 
ish-red precipitate  with  hydrocnioric  acid  or 
sodium  nydiozide.  The  solution  in  sulphuric 
acid  Lb  yeUow,  giving  a  yeUowish-red  precipitate 
on  dilution. 

Literature,— 'R,  P.  8664  of  1894 ;  D.  R.  P. 
80973  ;  F.  P.  238340 ;  A.  P.  646333. 

Trypan  Red  (M.) : 

SO,HC,H,.N,-CioH.(SO,H),NH, 


precipitate  with  hydrochloric  add.    It  is  used 
m  medicine. 

Pyrunldol   Brown  T   (Farbwerk  Amrnen- 
foort): 

C^,N,C.H,(OH), 


A 


^,N,CJIg(OH), 


Propared  from  tetrazotised  tolidine  and  ze- 
soroinol  (2  mols.).  The  zeddish-brown  aqueous 
solution  gives  a  brown  predpitate  with  nydro- 
chlorio  acid,  and  becomes  orownish-red  with 
sodium  hydroxide.  The  solution  in  sulphuric 
acid  IB  violet,  givim^  blackish-brown  precipi- 
tate on  dilution.  When  the  fibre  is  treated 
with  diazo-  solutions  a  deep  brown  is  obtained. 
Toloylene  Orsnge  G  (0.)  (By.)  (A.)  (L.); 
Azldine  Orange  G  (0.  J.);  IManll  Orange  H 
(SI') ;  Alkali  Orange  GT  (D.) ;  Renol  Orange  G 
(T.  M.) ;  Direct  Orange  G  (I.) ;  DIreet  Orange  Y 
(Soh.);  Oiydlamlne  Orange  G  (C);  Floto 
Orange  G  (By.) ;  Direct  Orange  G  (P.) : 

C  ,H,N,-C,H,(C50.H)-0H 


k 


,H,N,C,H4(NH,),S0,H 

Propared  from  tetrazotised  tolidine  and  1  mol. 
each  of  hydroxytoluic  add  (CH,:OH:CO,H 
=  1:2:3)  and  m-tolylenediaminesulpbonic  acid 
rCH, :  NH, :  NH, :  SOaH»l :  2  : 4  : 6).  The 
Drownish  •  yellow  aqueous  solution  gives  a 
yellowish-brown  precipitate  with  hydrochloric 
acid,  and  becomes  reddlBh-oranffe  with  sodium 
hydroxida  The  solution  in  smphuric  aeid  Is 
magenta-red,  giving  a  brown  predpitate  on 
dilution. 

Literature,— E.  P.  7997  of  1888 ;  D.  R.  P. 
44797,  47236 ;  A.  P.  386634. 

Toluylene  Orange  R  (0.)  (M.)  (L.)  (K.  8.) ; 
Aildlne  Orange  R  (0.  J.) ;  Alkali  Orange  RT 
(D.);  Renol  Orange  R  (T.  M.) ;  Direet  Orange  R 
(I.)  (Sch.) ;  Pyramine  Orange  RT  (B.) ;  Oxydl- 
amine  Orange  R  (C) ;  Plato  Orange  R  (By.) : 

07H,N,-C,H4(NHJ,SO.H 


i 


,H,N,C,H4(NHJ,-S0tH 

Propared  from  tetrazotised  tolidine  and  the 
above  m-tolylenediaminesulphonic  add  (2  mols.). 
The  orange  aqueous  solution  gives  a  bluish-red 
precipitate  with  hydrochloric  add.  The  solu- 
tion m  sulphuric  acid  is  brown,  giving  a  reddish 
precipitate  on  dilution. 

Literature.— E.  P.  4492  of  1887 ;  D.  R.  P. 
40906. 

Benzopnrporlne  B  (By.)  (A.)  (L.)  (Lev.)  (H.) 
(T.  M.)  (0.)  (Ontral  Dyestuff  and  Chemical  Co.) : 
Cotton  Red  B  (L) : 

C,H,N,CioH,(SO,H)NH, 


i 


,H,N,<5.^^S0,H)NH, 

Prepared  by  the  action  of  tetrazotised  tolidine 
on  /3-naphthylamine-6-sulphonio  add  (2  mols.) 
in  presence  ot  alkali.  Aqueous  solution,  orange- 
rea;  unchanged  by  sodium  hydroxide;  a 
brownish-red  predpitate  by  dilute  sulphuzio 
acid.  Dissolves  in  sulphuric  add  with  a  blue 
colour,  giving  a  brown  predpitate  on  dilution. 

Literature.— E,  P.  3803  of  1886 :  D.  R.  P. 
36616  ;  A.  P.  329633. 

Benzopurpurlne  4  B  (By.)  (A.)  (Lev.)  (T.  M.) 
(L.)  (0.)  (K.  S.)  (Farbwerk  Ammersfoort)  (B.  K.) 


AZO-  COLOURING  BiIATTERS. 


485 


(Sck)  (H.) ;  Cotton  Red  4  B  (B.)  (K.)  (I.) ; 
Cotton  Rod  BP  (P.) ;  Diamlno  Rod  4  B  (C.) ; 
DIanU  Rod  4  B  (M.) ;  Dlioet  Rod  4  B  (Soh.) : 

C^,N,CioH,(SO.H)NH, 


i 


J,H,N,-CxoH,(SO,H)NH, 

Prepared  b^  the  action  of  tetraKotised  tolidine 
on  naphthionio  acid  (2  mols.)-  About  twice 
the  theoretical  amount  of  naphthionio  acid  is 
used,  the  excess  being  regained  from  the  filtrate 
after  separating  the  ccuoor.  The  alternative 
method  of  preparation  by  oxidising  toluene- 
aEonaphthionio  acid  {cp.  Congo  Rm)  is  not 
used  teohnically.  Homologous  with  Congo  Red, 
and  isomeric  with  the  last.  Aqueous  solution 
orange-xed,  siving  a  red  precipitate  with  excess 
of  sodium  nydroxide;  olue  precipitate  with 
hydrochloric  acid;  dissolves  in  sulphuric  acid 
with  a  pure  blue  colour. 

Literature.—E.  P.  3803  of  1886, 6697  of  1896 ; 
D.  R.  P.  36616,  84893 ;  F.  P.  167876,  248210 ; 
A.  P.  329632. 

Bonioparpnrlno  6  B  (Jjev.)  (By.)  (A.)  (L.) 
(T.  M.)  (0.) ;  DUuUl  Rod  6  B  (M.) ;  Cotton  Red 
6  B  (L) ;  Diamine  Rod  6  B  (C).  Prepared  as 
above  fropi  tetrazoditolyl  and  a-naphthyl- 
amine-6-sulphonio  acid.  Colouring  matter  very 
similar  in  properties  to  the  precediiu[.  The 
same  constitution  is  assigned  to  Dlazo  firflUant 
Blaok  B  (By.),  which  gives  blues  or  blacks 
when  diazotised  and  developed  on  the  fibre. 

LUeraiure.'-K  P.  3803  of  1885;  D.  R.  P. 
35615. 

Diamine  Rod  B  (A.) : 

0,H,N,C,pH,(80jH)NH, 

C^,N,C„H,(SO,H)-NH, 

Prepared  from  tetrazoditolyl  and  1  mol.  of 
2-naphthylamine-7*8ulphonic  acid  and  1  mol.  of 
the  6-sulphonic  acid.  Deltapurpurino  6  B 
(By.)  (A.)  (Lev.)  (L.)  (M.)  (B.  K.)  (K.)  (K.  8.) ; 
Cotton  Porplo  5  B  (B.) ;  Cotton  Red  D  (I.)  is 
prepared  from  2  moJs.  of  the  crude  /3-naphth^l- 
amine-0-sulphonic  add.  It  is  therefore  a  mix- 
ture of  Diamine  Red  B  (50  p.c.).  Diamine  Red 
3  B  (25  p.c.),  and  Benzopurpurine  B  (25  p.c.). 
Aqueous  solution  red,  giving  a  brown  colouration 
with  acetic  acid,  and  a  brown  precipitate  with 
hydrochloric  acid.  Red  precipitate  with  sodium 
h^dronde.  Solution  in  sulphuric  acid  blue, 
giving  a  brown  precipitate  on  dilution. 

Lttenaure,'-iL  P.  5846  of  1886 ;  D.  R.  P. 
42021;  F.  P.  180728;  Ber.  1887,  20,  1430, 
2910,  3160,  3353. 

Diamine  Red  8  B  (A.) ;  Doltaparpnrino  T  B 
(Lev.).  Isomeric  with  the  preceding.  Prepared 
from  tetrazotised  tolidine  and  /3-naphthyl- 
amine-7-Bulphonic  add.  The  colouring  matter 
is  precipitated  from  its  aqueous  solution  by 
acetic  acid,  and  forms  an  insoluble  calcium 
salt.  Red  predpitate  with  sodium  hydroxide. 
Solution  in  sulphuric  acid  blue,  giving  brown 
predpitate  on  (ulotion. 

lAterature.—K  P.  4846  and  12908  of  1886 ; 
D.  R.  P.  41201,  48074 ;  F.  P.  178979 ;  Ber. 
1887,  20,  2910,  3160. 

Rooainrino'G  (By.)  (A.): 

Cja,N,CioHi(80,H)NHC,H. 


Prepared  from  tetrazotised  tolidine  and  1  mol. 
each  of  /3-naphthy]amine-7-Bulphonio  acid  and 
ethyl-i3-naphtnylainine-7-sulphonic  add.  When 
2  mols.  of  the  latter  acid  are  employed  the 
product  is  known  as  Rooainrino  B.  Both  dyes 
give  a  cherry-red  aqueous  solution,  which  sives 
a  reddish-violet  precipitate  with  hydrocnloric 
acid.  Their  solutions  in  Sulphuric  add  are 
blue,  giving  a  violet  predpitate  on  dilution. 

Literatwre.'-E.  P.  17083  of  1886 ;  D.  R.  P. 
41761 ;  F.  P.  180727. 

Brilliant  Pnrpnrlno  R  (A.)  (By.)  (L.)  x 

C,H,-N,CioH4(SO,H),NH. 


k 


l,H,N,C,^,(SO,H)NH. 

Prepared  from  tetrazotised  tolidine  and  1  mol. 
each  of  i3-iiaphthylamine-3  : 0-disulphonic  acid 
and  naphthionic  add.  The  red  aaueous  solution 
gives  a  black  precipitate  with  hvorochlorio  acid, 
and  a  red  one  with  sodium  hvdroxide.  The 
solution  in  sulphuric  add  is  blue,  giving  a 
blue-black  predpitate  on  dilution. 

Literature.— E,  P.  6687  of  1887 ;   D.  R.  P. 
41096 ;  F.  P.  160722. 

Brilliant  Porparino  4  B  (A.)  (By.) : 
C,H,N,Ci»H,(SO,H)NH, 


i 


,H,N,-CxoH,(SOaH)NH, 

Prepared  from  tetrazotised  tolidine  and  1  mol. 
each  of  i3-naphthylamine-6-sulphonic  acid  and 
naphthionio  add.  The  vellowish-red  aqueous 
solution  gives  a  violet-blue  predpitate  with 
hydrochloric  acid.  The  solution  in  sulphuric 
acid  is  violet-blue,  giving  a  violet-blue  precipi- 
tate on  dilution. 

LitenUure.—E.  P.  15296  of  1885 ;   D.  R.  P. 
39096 ;  F.  P.  160722. 

Azo  Blue  (By.)  (A.)  (Lev.) ;  Bonsoln  Blao  R 
(B.  K.) : 

C^,-N,CioHj(SO,H)OH 


A 


,H,N,-CioH,(SO,H)OH 

Prepared  bv  the  action  of  tetrazotised  tolidine 
on  a-naphthol-4-sulphonic  add.  Aqueous  solu- 
tion of  colouring  matter  violet,  becoming  crimson 
on  addition  of  sodium  hydroxide;  restored  to 
violet  by  dilute  sulphuric  add.  Dissolves  in 
sulphuric  add  with  a  pure  blue  colour,  giving 
violet  predpitate  on  dilution. 

Literature.— E.  P.  9510  of  1885 ;  D.  R.  P. 
35341 ;  F.  P.  171133  ;  A.  P.  366078. 

Congo  Corinth  B  (Bv.)  (A.)  (Lev.)  (B.  K.) 
(L.)  (K.  S.);  Cotton  Corinth  B  (O.);  Ronol 
Corinth  B  (T.  M.) ;  Bnflalo  Violet  4  R  (Soh.) ; 
Dianll  Bordeaux  B  (M.) : 

07H,N,CioH,(SO.H)NH, 


I 


i 


^,N,'Ci^,(SO,H)NH, 


?H,-N,-CioH5(SO,H)OH 

From  tetrazotised  tolidine,  naphthionio  acid> 
and  a-iiaphthol-4-Bulphonic  acid.  Aqueous  solu  - 
tion  magenta-red,  giving  violet  precipitate  with 
mineral  acids.  Blue  solution  in  sulphuric  acid  ; 
violet  precipitate  on  dilution. 

Literature.— E.  P.  16296  of  1885 ;  2213  and 
6687  of  1886 ;  D.  R.  P.  39096 ;  A.  P.  358865. 

Congo  Rod  4  R  (A.)  (By.) : 
C^.N,C.H,(OH), 


i 


»H,N,CioH,(SO,H)NH, 


486 


AZO-  COLOURING  MATTERS. 


From  tetrasotised  tolidine,  resorcinol,  and  naph- 
thionio  acid.  Aqueous  solution  brownish-red, 
violet  precipitate  with  mineral  acids,  brown 
precipitate  with  acetic  acid.  Solution  in 
sulphuric  acid  blue,  giving  violet  precipitate  on 
dilution. 

Laeraiiire,-^E,  P.  15296  of  1885 ;  2213  of 
1886 ;  D.  R.  P.  39096 ;  F.  P.  160722  (addition). 

Brimant  Congo  R  (A.)  (By.)  (L.) ;  BriUlant 
DianU  Rod  R  (M.) ;  Azldino  Searlot  R  (0.  J.) : 

CtH,N,CioH4(SO,H),NH, 

C,He-N,-CioH,(SO,H)NH, 

From  tetrazotised  tolidine,  /3-naphthylamine- 
3  :  6-di8ulphonic  acid  and  /3-naphtiiylamine-6- 
sulphonic  acid  (Br6nner*s).  Aqueous  solution 
brownish-rod,  giving  a  similarly  coloured  pre- 
cipitate with  mineral  acids.  Solution  becomes 
bluer  with  acetic  acid.  Orange  precipitate  with 
sodium  hydroxide.  Blue  solution  in  sulphuric 
add,  giving  dark-brown  precipitate  on  dilution. 

LU€ratwe.—E.  P.  6687  of  1887 ;  D.  R.  P. 
41095. 

Aio  Blaok  Blao  B,  R  (O.) : 

OtH,-N,C,H,(OH)NHC,H5 


i, 


IAN,CioH,(SO,H),(OH)NH, 

Prepared  from  tetrazotised  tolidine  and  1  mol. 
each  of  m-hydrozydiphenylamine  and  8-amino- 
a-naphthol-3  :  6-disulphomc  acid  (H-acid).  Solu- 
tion m  water  is  brownish- violet  and  in  sulphuric 
acid  blue,  giving  a  bluish-violet  precipitate  on 
dilution. 

Literature.— K  P.  10861  of  1891 ;  D.  R.  P. 
70201 ;  A.  P.  402415. 

Aio  Haavo  B  (0.) : 

C,H,N,Ci^,(SO,H)^OH)NH, 

Prepared  from  tetrazotised  tolidine  and  1  mol. 
each  of  8-amino-a-naphthol-3 : 6-disulphonic 
add  (H-acid)  and  a-naphthylamine.  Violet 
aqueous  solution  gives  a  violet  precipitate  with 
h  vdrochlorio  acid,  and  becomes  rather  bluer  with 
dilute  acetic  acid.  Solution  in  sulphuric  acid 
is  blue,  becoming  violet  on  dilution.  When  jB- 
naphthylamine  is  used  instead  of  the  a-cora- 
pound  the  product  is  Naphthazurino  B  (0.),  the 
reactions  of  which  are  similar  to  the  above. 

Literature.— Ab  above  and  A.  P.  462415, 
606999. 

Chieago  Blao  2  R  (A.);  Bonxo  Bluo  2  R 
(By.) ;  Diamino  Blao  C  2  R  (C.) ;  Azldlno  Wool 
Blao  R  (C.  J.) : 

C,H,-N,CioH,(SO,H)-OH 


i 


l,H,-N,-CioH,(SO,H)(OH)NH, 

Prepared  from  tetrazotiaed  tolidine  and  1  mol. 
each  of  /3-naphthol-8-sulphonio  acid  and  8- 
amino-a-naphthol-5-sulphonic  acid.  The  violet- 
blue  aqueous  solution  gives  a  dark-blue  precipi- 
tate with  hydrochloric  acid,  and  becomes 
reddish-violet  with  sodium  hydroxide.  Solution 
in  sulphuric  acid  is  blue,  giving  a  blue  precipitate 
on  duution.  The  corresponding  colour  from 
dianisidine  is  Azidino  Wool  Blao  B  (G.  J.). 

Literature.— E.  P.  27609  of  1907 ;  D.  R.  P. 
203535,  209269 ;  F.  P.  383747 ;  A.  P.  888036. 

Ozamlno  Blao  4  R  (B.) ;  Aildlno  Blao  8  RH 


(C.  J.) ;  Naphtbamino  Bluo  3  RE  (K.) ;  Dianll 
Azarino  8  R  (M.);    BonzoaKarino  8  R  (By.) 

(O.): 

C7H,N,CioH,(80,H)-OH 


i. 


7H,N,CioH4(SO,H)(OH)NH, 

Prepared  from  tetrazotised  tolidine  and  1  mol. 
each  of  6-amino-a-naphthol-3-sulphonic  acid  and 
a-naphthol-4-sulphonic  add.  Violet  aqueous 
solution  is  precipitated  with  hydrochloric  add 
or  sodium  hydroxide.  Solution  in  sulphuric 
acid  is  blue,  giving  a  violet  precipitate  on 
dilution. 

Literature.— B.  P.  2614  of  1893 ;  D.  R.  P. 
93276  ;  F.  P.  227892  ;  A.  P.  521095. 

Colambia  Blao  0  (A.) ;  Bonzo  Rod  Blao  6 
(By.);  Dlamlno Blao  LG  (G.) : 

C^,-N,-CxoH4(SO,H),OH 


k 


!,H,N,C,oH4(SO,H)(OH)-NH, 

Prepared  from  tetrazotised  tolidine  and  1  moL 
each  of  a-naphthol-3 : 8-diBulphonic  acid  and 
8-amino  -  d  •  naphthol  •  6  -  sulphonic  acid.  Blue 
aqueous  solution  gives  a  blue  precipitate  with 
hydrochloric  acid,  and  a  reddish-violet  one 
with  sodium  hydroxide.  Solution  in  sulphuric 
acid  is  greenish-blue,  giving  a  reddish-violet 
precipitate  on  dilution. 

Chioago  Blao  R  (A.)  (By.) ;  Diamino  Blao  CR 
(G.): 

G,H,N,GioH4(SO,H)(OH)NH, 


i 


tH,-N,-GioH«(SO,H)(OH)-NH, 

Prepared  from  tetrazotised  tolidine  and  8-amino- 
a-naphthol-5-sulphomc  acid  (2  mols.).  The 
violet-blue  solution  gives  a  dsik-violet  precipi> 
tate  with  hydrochloric  acid.  The  solution  in 
sulphuric  acid  is  cornflower  blue, jgiving  a  bluish- 
violet  precipitate  on  dilution.  Toe  correspond- 
ing colour  from  dianisidine  is  ChloagO  Blao  B 
(A.)  (By.) ;  Dlamlno  Blao  CB  (0.). 

Literature.— A.  P.  506284. 

Dianll  Blao  B  (M.) : 

C^,-N,-Gi^,{SO,H)^OH), 


i. 


^,-N,-GioH,(SO,H),(OH), 

Prepared  from  tetrazotised  tolidine  and  2  mols. 
of  1 :  8-dihydroxynaphthalene-3  :  6-diBulphonio 
acid  (chromotrope  acid).  The  blue  aqueous 
solution  is  not  onanged  with  hydrochloric  add 
or  sodium  hydroxide.  The  solution  in  sulphuric 
add  is  deep-blue,  becoming  bluish-violet  on 
dilution. 

The  corresponding  colour  from  benzidine  is 
Dianll  JBlao  R,  and  from  dianisidine  Dianll 
Blao  G,  and  when  1  mol.  each  of  chromotrope 
add  and  a-naphthol-4-sulphonic  add  are  used 
the  product  is  Dianll  Bmo  8  R  (M.) ;  Naph- 
tbamino Brilliant  Blao  2  R  (K.) ;  Bonzo  Mow 
Blao  2  B  (By.). 

Diamino  Blao  8  B  (0.) ;  Bonzo  Blao  8  B  (By.) ; 
Congo  Blao  8  B  (A.)  (Lev.) ;  Azldlno  Blao  8  B 
(G.  J.);  Chlorazol Blao  8 B  (H.) ;  Ni^hthamlno 
Blao  8  BX  (K.);  DIanU  Blao  H  8  Q  (H.); 
Benzamlao  Blao  8  B  (D.) ;  Niagara  Blao  8  B 
(Sch.) : 

G,H,N,-CioH,(SO,H),(OH)NH, 


<i 


,H,-N,CioH,(SOaH),(OH)NH, 


AZO-  COLOURING  MATTERS. 


48*; 


Prepared  from  tetrazotiaed  tolidine  and  8-amino- 
a-naphthol-S  :  6-disulphonio  acid  (H-acid ;  2 
moLs.)-  When  used  in  medicine  it  is  known  as 
Trypan  Blue  (M.).  The  violet  aqueous  solution 
becomes  bluer  with  hydrochloric  acid,  and  gives 
a  precipitate  with  excess..  The  solution  in 
sulphuric  acid  is  blue,  giving  a  violet  precipitate 
on  dilution. 

Literaiure.—E.  P.  13443  of  1890;  1742  of 
1891 ;  D.  R.  P.  74593 ;  F.  P.  201770,  210033. 

EboU  Blue  B  (L.).  Isomeric  with  the  above, 
8-amino-a-naphthol-4  :  6-disulphonio  acid  being 
used  insteaa  of  H-acid.  Tne  blue  aqueous 
solution  gives  a  blue  precipitate  with  hydro- 
chloric acid,  and  becomes  reddish-violet  with 
sodium  hydroxide.  The  solution  in  sulphuric 
acid  is  blue. 

Literaiure.—E.  P.  19253  of  1896 ;  D.  R.  P. 
apia.  F.  8626;  A.  P.  606436,  606437,  606438, 
606439. 

Diamine  Blue  BX  (0.) ;  Benzo  Blue  BX  (By.) ; 
Congo  Bine  BX  (A.)  (Lev.) ;  Azidlne  Blue  BX 
(C.  J.) ;  Niq^itliAmine  Blue  BXR  (K.) ;  DIanll 
Blue  HQ(M.);  EboU  New  Blue  2  B  (L.) ;  Benz- 
amine  Blue  BX  (D.) ;  Niagara  Blue  BX  (Sch.) : 

C7H,N,C,aH,(S0,H),(0H)NH, 


i, 


l^,N,CiaH,(S0,H)0H 

Prepared  from  tetrazotised  tolidine  and  1  mol. 
each  of  a-naphthol-4-sulphonic  acid  and  8- 
amino-a-naphtliol-3 : 6-disulphonic  acid  (H- 
acid).  The  bluish-violet  aqueous  solution  gives 
a  violet  precipitate  with  hydrochlorio  acid,  and 
becomes  oluish-red  with  sodium  hydroxide.  The 
solution  in  sulphuric  acid  is  blue,  giving  a  violet 
precipitate  on  dilution. 

likrtUvre.—E,  P.  1742  of  1891 ;  D.  R.  P. 
74693 ;  F.  P.  201770  addition. 

Dlieet  Blue  R  (L): 

C,H.-N,-CxoH,(CO,H)(OH),SOaH 


k 


?,H.N,-CioH,(SO,H)OH 

Prepared  from  tetrazotised  tolidine  and  1  mol. 
each  of  1 :  7-dihydroxy-6-carboxynaphthalene- 
3-sulphonic  acid  and  a-naphthol-4-sulphomc 
acid.  The  violet  aqueous  solution  gives  a  violet 
precipitation  with  hydrochloric  acid,  and 
Deoomes  violet-red  with  sodium  hydroxide.  The 
solution  in  sulphuric  acid  is  blue.  The  corre- 
sponding colour  from  dianisidine  is  Direct 
Bine  B  (I.). 

UiercUur€.—E.  P.  14161  and  14263  of  1892  ; 
D.  R.  P.  67000,  76268 ;  F.  P.  219876,  220468 ; 
A.  P.  493563,  493564. 

Indazurlne  RM  (I.).  Isomeric  with  the 
preceding.  A  different  naphthoic  acid,  viz. : 
1  :  7-dihydroxy-2  -  carboxynaphthalene  -  4  -  sul- 
phonic  acid  is  used,  the  other  constituents  being 
the  same.  The  violet- blue  aqueous  solution 
becomes  bluer  with  hvdrochloric  acid  and  red 
with  sodium  hvdroxide.  The  solution  in  sul- 
phuric acid  is  blue,  giving  a  violet  precipitate 
on  dilution.  The  corresponding  colour  from 
dianisidine  is  IndaEUrine  GM  (I.). 

Literaiure,—A,  P.  624070. 

Indazurlne  TS  (I.) : 

C^,N,CioH,(CO.H)(OH),H50,H 


k 


a-naphthol-3*sulphonic  acid  is  used  instead  of 
a-naphthol-4-sulphonic  acid.  The  violet-blue 
aqueous  solution  becomes  redder  with  acids  or 
alkalis.  The  solution  in  sulphuric  acid  is  blue, 
giving  a  violet  precipitate  on  dilution. 

Ltteratiire, — ^As  aoove. 

MilUng  Scarlet  4  R  (M.) ;  Acid  Anthracene 
Red  8  B  (By.);  Florida  Red  R  (L.) : 

HSO,C7H,N,-OioH,OH 

HS04C^,N,CioH.OH 

Prepared  from  tetrazotised  toUdinedisulphonio 
acid  and  i8-nap)ithol  (2  mols.).  The  carmoisine- 
red  aqueous  solution  nves  a  violet  precipitate 
with  hydrochlorio  acid.  The  solution  in  sul- 
phuric acid  is  violet-red. 
Diamine  Yellow  N  (C.) : 

0,H50-C,H,N,C,H,(GQ,H)OH 


i. 


I^.N,-CioH4(SO,H)(OH)NH, 
Prepared  as  the  preceding,  except  that  7-amino- 


!,H,N,C,H,0-C,H, 

Prepared  by  combinim^  tetrazotised  ethoxyben- 
zidine  first  with  salicyQc  acid  (1  mol.)  and  then 
with  phenol  (1  mol.)  and  ethylating  the  product. 
The  yellow  aqueous  solution  ^ives  a  greenish 
precipitate  with  hydrochloric  acid  and  a  reddish- 
vellow  with  sodium  hydroxide.  The  solution, 
m  sulphuric  acid  is  violet,  giving  a  greenish- 
brown  precipitate  on  dilution. 

Liierature.-'E.  P.  14464  of  1887 ;   D.  R.  P. 
46134 ;  F.  P.  186666,  186667 ;  A.  P.  380067. 

Diamine  Blue  8  R  (C.) : 

C,H50C,H,N,CijP5(SO,H)OH 

CeH4N,CioH5(SO,H)OH 

Prepared  from  tetrazotised  ethoxybenzidine  and 
a-naphthol-4-8ulphonic  acid  (2  mols.).  The 
reddish-blue  aqueous  solution  is  not  changed 
with  hydrochloric  acid,  but  becomes  reddish- 
violet  with  sodium  hvdroxide.  The  solution  in 
sulphuric  acid  is  dark-blue,  giving  a  violet 
precipitate  on  dilution. 

LtiercUure. — As  above. 

Diamine  Blue  B  (0.) : 

C,H,OC,H,N,CioH4(SO,H),OH 


i 


!eH4N,CiaH5(SO,H)OH 

Prepared  from  tetrazotised  ethoxybenzidine  and 
1  mol.  each  of  /3-naphthol-3  :  7-dl8ulphonic  acid 
and  a-naphthol-4-sulphonic  acid.  The  blue 
aqueous  solution  gives  a  blue  precipitate  with 
hydrochloric  acid,  and  becomes  roddish-blue 
with  sodium  hydroxide.    The  solution  in  sul- 

Shuric  acid  is  blue,  giving  a  blue  precipitate  on 
ilution. 
Literature. — ^As  above. 
Diamine  Blue  Blacls  E  (C.) : 

C,H,OC,H,N,CioH,(SO,H),OH 


k 


!,H4N,C,oH4(SO,H)(OH)NH, 

Prepared  as  the  preceding,  except  that  7 -amino- 
a-naphthol-3-sulphonio  acid  is  used  instead  of 
a-naphthol-4-sulphonic  acid.  The  combination 
is  effected  in  aJkaline  solution.  The  blackish- 
blue  aqueous  solution  gives  a  blue  precipitate 
with  hydrochloric  add,  and  is  not  changed  with 
sodium  hydroxide.  The  solution  in  sulphuric 
acid  is  blackish-blue,  giving  a  blue  precipitate 
on  dilution. 


488 


AZO-  COLOURING  BiATTBRS. 


LUerfUure.—E.  P.  16699  of  1889 ;   D.  R.  P. 
67867  ;  F.  P.  201770. 
Dlaiiirine  B  (By.) : 

CH,OC,H,N,CioH,(SO,H)-NH, 

CH,OC,H,-N,-CioH,(SO,H)NH, 

Pzepared  from  tetrazotiaed  dianiBidine  and  a-' 
napnthylamme-6-(or  7-)siilphomo  acid  (Cleye's 
aoid)  (2  mols.).  The  browniflh-ted  aqueous 
solution  ^vee  a  blue  preoipitate  ifith  njdro- 
ohlorio  acid  and  a  soluble  red  one  with  sodium 
hvdrozida.  The  solution  in  sulphurio  acid  is 
blue,  giving  a  blue  precipitate  on  dilution. 

LitenUure,—!),  K.  P.  66262. 

Benxopuipurtne  10  B  (By.)  (Lev.)  (K.)  (L.) 
(A.)  (0.)  (K.  S.)  (T.  M.) ;  DiAiiU  Red  10  B  (M.) ; 
Cotton  Red  10  B  (I.)  (P.) ;  Diamine  Red  10  B 
(C);  Buffalo  Cardinal  7  B  fSoh.).  Isomeric 
wiUi  the  pieoedinff.  Prepared  from  tetrazotised 
dianimdine  and  2  mols.  of  naphthionio  aoid. 
The  carmine-red  aqueous  solution  gives  a  blue 
precipitate  with  hvdrochlorio  acid  and  a  red 
one  with  sodium  nydroxide.  The  solution  in 
sulphuric  acid  is  blue,  giving  a  blue  precipitate 
on  dilution. 

Literaiure,—E,  P.  14424  of  1886 ;  D.  R.  P. 
88802 ;  F.  P.  173042  ;  A.  P.  481964. 

Azo-  Violet  (By.)  (A.)  (L.)  (Lev.) : 

CH,OC.H,N,<:iioH5(80,H)NH, 

CH,0-C,H,-N,-CioH,(SO,H)OH 

Tetrazotised  dianisidine  (1  md.)  is  combined 
with  1  mol.  of  naphthionio  acid,  and  then  with 
1  mol.  of  a-naphthol-4-Bulphonio  acid.  Aqueous 
solution  reddish- violet,  eiving  blue  precipitate 
with  mineral  acids  and  Uuish- violet  colouration 
with  acetic  acid.  Solution  turned  magenta 
by  sodium  hydroxide.  Dissolves  with  a  blue 
colour  in  sulphurio  acid,  giving  a  blue  precipitate 
on  Hil^ttion, 

Literature.— E.  P.  14424  of  1886 ;  7283  of 
1886 ;  D.  R.  P.  40247 ;  F.  P.  173042 ;  A.  P. 
447302. 

Benzoazurlne  G  (By.)  (A.)  (L.)  (Lev.)  (K.) 
(0.)  (K.  8.) ;  Dlanll  Azurlne  G  (M.) ;  Renol 
Blue  B  (T.  M.) ;  Cotton  Blue  8  G  (L) ;  Benzoin 
Blue  GN,  SGN,  5GN  (B.  K.);  DIreet  Blue  G 
extra  (Sch.);  Oxamlne  Blue  A  (B.);  Azidlne 
Blue  BA  (C.  J.y. 

OH,OC,H,N,C,oH,(SO,H)OH 

OH,OC,H,N,<:!ioH,(SO,H)OH 

Prepared  by  the  action  of  tetrazotised  dianisi- 
dine on  a-naphthol-4-sulphonio  acid.  Aqueous 
solution  bluish-violet,  becoming  red  on  addition 
of  sodium  hydroxide;  dark- violet  precipitate 
with  dilute  hydrochlorio  acid.  Dissolves  in 
sulphuric  acid  with  a  blue  colour,  givii^  violet 
precipitate  on  dilution.  BenzoazurlneR  (By.) 
(A.)  (L.)  (0.)  is  a  mixture  of  benzoazurlne  G 
and  azo  Uue. 

Literaiurc—E.  P.  14424  of  1886 ;  D.  R.  P. 
38802 ;  F.  P.  173042 ;  A.  P.  367273,  481964. 

Benzoazurlne  8  G  (By.)  (A.)  (L.)  (Lev.)  (SL). 
Isomeric  with  the  above.  a-Naphthol-6-sul- 
phonic  acid  (Laurent's  add)  is  used  instead  of 
the  4-sulphonio  acid.  Aqueous  solution  bluish- 
violet,  giving  bluish-violet  precipitate  with 
hydrochloric  acid  and  becoming  vi<Met-red  with 


sodium  hydroxide.    Solution  in  sulphurio  add 
is  blue,  giving  violet  precipitate  on 'dilution. 
Literature, — ^As  above. 

Congo  Blue  8  B  (By.) : 

CH,0  0,H,-^,-C,oH4(SO,H),OH 

CH,OC,H,N,-CioH,(SO,H)OH 

Prepared  from  tetrazotised  dianisidine  and  1 
mol.  each  of  /3-naphthol-3 : 6-disulphonio  add 
and  a-naphthol-4-sulphonic  add.  Blue  aqueous 
solution  gives  a  dark- blue  precipitate  with 
hydrochlorio  acid,  and  becomes  magenta-red 
with  sodium  hydroxide.  Solution  in  sulphurio 
add  is  blue,  giving  a  blue  precipitate  on  dilution. 

LUeraiure.—E.  P.  7283  of  1886;  D.  R.  P. 
40247 ;  F.  P.  173042  (addition) ;  A.  P.  467162. 

Chlorazol  Blue  R  and  8  G  (H.) : 

CH,0  0,H,N,-C,oH4C!l(SO,H)OH 

CH,0-C,H,-N,C,oH4a(SO,H)OH 

Prepared  from  tetrazotised  dianisidine  and 
2  mob.  of  chloro-a-naphthol-6-  and  -4-sulphonio 
acids  respectivdy.  The  violet  aqueous  solu- 
tion undergoes  httle  change  with  nydrochlorio 
acid,  but  turns  crimson  wim  sodium  hydroxide. 
The  solution  in  sulphurio  add  is  greeniab-blue 
(R)  or  green  (3  G). 

Literature.— E.  P.  12086  of  1898. 

Diamine  Brilliant  Blue  G  (C.) : 

CH,0-CgH,N,-CioH,Cl(SO,H),OH 

CH,0-C.H,N,-CiACl(SO,H),OH 

Prepared  from  tetrazotised  dianiftidine  and  2 
mob.  of  8-chloro-a-naphthol-3  :  O-disulphonio 
acid.  Bluish-violet  aqueous  solution  gives  a 
soluble  violet  predpitete  with  hydrochlorio  acidp 
and  becomes  cherry-red  with  sodium  hydroxide. 
Solution  in  sulphuric  acid  is  greenish-bine, 
turning  violet  on  dilution. 

Literature.— E.  P.  1920  of  1894 ;  D.  R.  P. 
79066,  82286 ;  F.  P.  236271 ;  A.  P.  632126. 
636037. 

examine  Blue  B  (B.) : 

CH,OC,H,N,OxoH,(SOja)OH 

CH,OC,H,N.<JioH4(SO,H)(OH)NH, 

Prepared  from  tetrazotised  dianisidine  and  1  mol. 
each  of  6-amino-a-naphthol-3-sulphonio  add 
and  a-naphthol-4-sulphomo  acid.  Dark-blue 
aqueous  solution  turns  reddish-violet  with 
sodium  hy^oxide,  and  pale  violet  with  hydro- 
chlorio  acid.  The  solution  in  sulphurio  add  is 
bluish-green,  becoming  violet  on  dUution. 

Literature.— E.  P.  2370  of  1893 ;  D.  R.  P. 
82672  ;  V.  P.  229263 ;  A.  P.  668344. 

Chleago  Blue  6  B  (A.) ;  Brilliant  Benio  Blue 
6B(By.);  Diamine  Sky  Blue  FF  (C.) ;  Azidine 
Sky  Blue  FF  (G.  J.) ;  Chlorazol  Sky  Blue  FF  (H.) ; 
Dianol  Brilliant  Blue  6  B  (Lev.);  Oxamlne 
Sky  Blue  6  B  (B.) ;  Dlanll  Sky  Blue  FH  (M.) : 

CH,OC,H,N,CioH,(SO.H),(OH)NH, 

0H,-OC,H,-N,-CioH,(SO,H),(OH)-NH, 

Prepared  from  tetrazotised  dianisidine  and  2 
mols.  of  8-amino-a-naphthol-6 : 7-disulphonio 
aoid  (8-aoid).  The  oomoination  is  effeotod  in 
alkaline  solution.  Blue  aqueous  solution  is  not 
changed  with  hydrochloric  acid,  but  becomes 


AZO-  COLOURING  MATTERS. 


489 


biuiflh-yiolet  with  sodium  hydroxide.  Solution 
in  Bolphario  acid  Ib  bluish-green,  becoming  pure 
blue  on  dilution. 

Diamine  Sky  Blue  (0.) ;  Benzo  Sky  Blue  (By.) ; 
Congo  Sky  Blue  (A.) ;  0lanol  Sky  Blue  (Ley.) ; 
Renol  Pure  Blue  (T.  M.);  Aildlne  Slqr  Blue 
(C.  J.) ;  Chlonzol  Blue  6  Q  (H.) ;  Naphthamlne 
Blue7B(K.};  DUnil Blue H 6 G (M.) ;  examine 
Sky  Blue  5  B  (B.) ;  Bencamlne  Sky  Blue  (D.) ; 
Benzoin  Sky  Blue  (B.  K.) ;  Dlreet  Blue  RBA  (L.) ; 
Niagara  Blue  4  B  (Sch.).  Isomeric  with  the 
preMding.  Two  mols.  of  8-ftmino-a-naphthol- 
3  :  6-di8ulphonio  acid  (H-acid)  are  used  as  com- 
ponents. Blue  aqueous  solution  is  not  changed 
with  hydrochloric  acid,  but  becomes  redder 
with  sodium  hydroxide.  Solution  in  sulphuric 
add  is  bluish-green,  becoming  pure  blue  on 
dilution. 

Literaiure.—E.  P.  1742  of  1891 ;  D.  R.  P. 
74593  ;  P.  P.  201770 ;  A.  P.  464135. 

Ghleago  Blue  RW  (A.);  Beuzo  Blue  RW 
(By.) ;  Diamine  Blue  RW  (C.) ;  Dianol  Blue 
RW  (Lev.) : 

CH,OC,H,N,C,oH,(SO,H),(OH)NH, 

CH,0-C,H,N,CioH,OH 

Prepared  from  tetrazotised  diamsidine  and  1 
mol.  each  of  8-amino-a-naphthol-5 : 7-disul- 
phonio  acid  and  3-naphthol.  Blue  aqueous  solu- 
tion gives  a  blue  precipitate  with  hydrochloric 
acid,  and  becomes  violet  with  sodium  hydroxide. 
Solution  in  sulphuric  acid  is  green,  giving  a 
violet  precipitate  on  dilution. 

Chleago  Blue  4  B  (A.) ;  Benso  Sky  Blue  4  B 
(By.) ;  Diamine  Sky  Blue  G  4  B  (C).  Instead 
of  ^-naphthol  in  the  preceding  colouring  matter, 
S-amino-a-naphthol-o-sulphonio  acid  is  used. 
Blue  aqueous  solution  gives  a  bluish-violet 
precipitate  with  hydrochloric  acid,  and  is 
unchanged  with  sodium  hydroxide.  Solution 
in  sulphuric  acid  is  bluish-green,  giving  a  blue 
precipitate  on  dilution. 

Indaiurine  B  (I.) : 

CH,OC,H,N,CioH4(SO,H),OH 

CH,-0-C,H,N,CioH4(SO,H)(OH), 

Prepared  from  tetrazotised  diamsidine  and  1  mol. 
each  of  1 :  7-dihvdroxynaphthalene-4-Bulphonic 
acid  and  /3-naphthol-3  :  6-ai8ulphonic  acid.  Blue 
aqueous  solution  turns  bluer  with  hydrochloric 
acid  and  red  with  sodium  hydroxide.  Solution 
in  sulphuric  acid  is  blue,  giving  a  reddish-blue 
precipitate  on  dilution.  When  m-tolylenedi- 
amine  is  used  instead  of  R-salt  the  colour  pro- 
duced is  called  Dlreet  Violet  BB  (I.).  The 
violet  aqueous  solution  shows  the  same  reactions 
as  the  above,  as  does  also  the  solution  in  sul- 
phuric acid. 

Literaiurc—J).  R.  P.  524069 ;  A.  P.  524069. 

BriOlant  Azurlne  6  G  (By.)  (A.)  (L.) : 

.       CH,-0-C.H»N,C,oH4(SO,H)(OH), 

I 
CH,-0-C,H,-N,0,oH4(SO,H)tOH), 

Prepared  bv  combining  tetrazotised  diamsidine 
with  2  mols.  of  1  : 8-dihydroxynaphthalene-4- 
sulphonio  acid  in  acetic  acid  solution.  Aqueous 
solution  is  bluish- violet ;  with  hydrochloric  acid 
gives  a  blue  precipitate,  and  with  sodium 
hydroxide  becomes  red.    Solution  in  sulphuric 


acid  IB  greenish-bine,  giving  a  dark  reddish- 
blue  precipitate  on  dilution. 

L&emtufe.— E.  P.  14424  of  1885 ;  13665  of 
1889 ;  D.  R.  P.  57166 ;  F.  P.  173042 ;  A.  P. 
417294. 

Indaiurine  BB  (I.) : 
CH,0-0,H,N,C,oH,(CO,H)(SO,H)(OH)g 

I 
CH,OCja,N,CioH4(SO,H),OH 

Prepared  from  tetrazotised  dianisidine  and  1  moL 
each  of  1  :  7-dihydroxy-2-carboxynaphthalene- 
4-sulphonic  acid  and  3-naphthol-3 : 6-aisulphonic 
acid  (R-salt).  Blue  aqueous  solution  becomes 
sUghUy  bluer  with  hydrochloric  acid,  and  redder 
with  sodium  hydroxide.  Solution  in  sulphuric 
acid  is  greenish-blue,  giving  a  blue  precipitate 
on  dilution. 

Literature.—A.  P.  524070. 

Indazurine  5  GM  (I.) : 

CH,OC,H,N,-C,oH,((X),H)(SO,H)(OH), 

CH,OC,H,N,CipH,(SO,H),(OH)NH, 

Prepared  as  the  preceding,  except  that  8-amino- 
a-naphthol-3 : 6-disulphonio  acid  (H-acid)  is 
used  instead  of  R-salt.  The  pure  blue  aqueous 
solution  is  not  changed  with  hydrochloric  acid, 
but  becomes  redder  with  sodium  hydroxide. 
The  solution  in  sulphuric  acid  ia  bluish-green, 
becoming  bluish- violet  on  dilution. 

Literature, — ^As  above. 

Hessian  YeUow  (L.) : 

CH-C,H^SOja[)N,C,H,(CO,H)OH 


k 


iHC,H,(SO,H)N,0,H,(CO,H)OH 

Prepared  from  tetrazotiBed  diaminostilbenedi- 
sulphonic  acid  ^  and  salicylic  acid.  Aqueous 
solution  oohreous,  giving  blackish  precipitate 
with  mineral  acids.  Solution  reddened  by 
sodium  hydroxide.  Reddish-violet  solution  in 
sulphuric  acid,  giving  blackish  precipitate  on 
dilution. 

LUerature,--E,  P.  4387  of  1886;  D.  R.  P. 
38735 ;  A.  P.  350299,  350230. 

Hessian  Purple  K  (L.)  (By.): 

CH-C,H,(SO,H)N,-CioH,NH, 

CHC,H,(SO,H)N,CjoH,NH, 

From  tetrazotised  diaminostilbenedisulphonic 
acid  and  i8-naphthylamine.  Aqueous  solution 
red,  givins  bluish-bJaok  precipitate  with  mineral 
acids,  and  violet-black  precipitate  with  acetic 
acid.  Red  colouration  or  precipitate  with  sodium 
hydroxide.  Blue  solution  in  sulphuric  acid, 
givinff  bluish-black  precipitate  on  cululion. 
References  as  hi  preceding. 
Brilliant  TeUow  (L.)  (A.)  (By.) : 

CH-C,H^S0,H)N,-C,H40H 


h 


!H-C,H,(S0,H)N,C,H40H 
From  the  same  tetrazo-disulphonic  add  and 

1  UlaminostUbenedisulphonic  add 

CH  =  CH 

V 

NHt     NH, 

is  prepared  by  boillog  p-nltrotolnene-o-sulphonic  acid 
with  Bodium  hydroxide  and  reducing  the  product  with 
dnc-doit. 


SOaHi 


490 


AZO-  COLOURING  MATTERS. 


phenol.  Aqueous  solution  orange,  giving  violet 
precipitate  with  mineral  acids.  Dissolves  with 
a  reddish-violet  in  sulphuric  acid,  giving  a 
violet  precipitate  on  dilution. 

References  as  in  preceding. 

Chrysophenine  G  (K.  S.)  (L.)  (A.)  (By.); 
Chiysobarlne  G  extra  cone.  (T.  M.);  Phenlne 
Yellow  (P.) ;  Azidine  Yellow  CP  (C.  J.) ;  Direct 
Yellow  CRG  (L.) ;  Aarophenine  0  (M.) ;  Pyra- 
mine  Yellow  G  (B.) ;  Trlazol  Yellow  G  (0.) : 

CHC,H,(S0,H)N,C,H40C,H, 


h 


3HC,H,(SO,H)N,C,H40C,H, 

Prepared  by  ethylating  the  preceding  colouring 
matter.  Aqueous  solution  orange,  giving  brown 
precipitate  with  mineral  acids.  Dissolves  with 
a  reddish- violet  colour  in  sulphuric  add,  giving 
blue  precipitate  on  dilution. 

ZAter€Uure.—E.  P.  3994  of  1887 ;  D.  R.  P. 
42466;  F.  P.  182063;  Ber.  1894,  27,  3367; 
1903,  36,  2975. 

Hessian  Brilliant  Purple  (L.): 

CHC,H,(SO,H)N,-OioH,(SO,H)NH, 

II 
CHC,H,(SO,H)N,-C,oH,(SO,H)NH, 

Prepared  from  tetrazotised  diaminostilbenedi- 
sulphonic  acid,  and  2  mols.  of  jS-naphthylamine- 
6-sulphonio  acid.  Purple-red  aqueous  solution 
gives  bluish-black  precipitate  with  hydrochloric 
acid  and  carmine-red  precipitate  with  sodium 
hydroxide.  Solution  in  smphuric  acid  blue, 
giving  a  bluish-black  precit>itate  on  dilution. 
Rieferences  as  for  Hessian  Yellow. 

Stilbene  Colouring  Matters. 

The  colouring  matters  which  have  hitherto 
been  classified  under  this  head  are  produced  by 
alkaline  condensation  and  oxidation:  of  ^-nitro- 
toluenesulphonic  acid  under  various  conditions. 
They  have  generally  been  considered  to  be 
nitroso-  or  azozy-  stilbene  derivatives,  but  the 
recent  researches  of  A.  G.  Green  and  his  colla- 
borators have  shown  that  all  the  colouring 
matters  of  this  group  must  be  regarded  as  azo- 
dyes  (Chem.  Soc.  Trans.  1904,  85,  1424,  1432 ; 
1906,  89, 1602  ;  1907,  91,  2076 ;  1908,  93,  1721 ; 
J.  Soc.  Dvers,  1^7,  23,  162).  The  first  action 
of  alkali  hydroxide  on  p-nitrotoluenesulphonic 
acid  leads  to  the  formation  of  a  dinitrosoetubene- 
disulphonic  acid,  one  molecule  of  which  is  oxi- 
dised at  the  expense  of  a  second  molecule,  and 
the  remaining  two  nitrogen  atoms  of  two  mole- 
cules combine  to  form  an  azo-  group  in  a 
distilbene  molecule : 

CHC,H,(SO,H)Np 


2 

CHC,H,(SO,H)NO 
CHC,H,(SO,H)N^=^NC,H,(SO,H)CH 

II     ^  II 

CHC.H,(SO,H)NO,     NO,C,H,(SO,H)CH 

The  equation  represents  the  formation  of  the 
greenest  yellow  of  the  series  (stilbene  yellow 
8G  :  see  below).  The  redder  vellows  and  oranges 
may  be  regarded  as  formed  therefrom  by  the 
reduction  of  the  two  nitro-  groups,  first  to  an 
azoxy-  and  finally  to  an  azo-  group. 

Sun  YeUow  (G.)  (K.  S.) ;  Afghan  YeUow  (H.) ; 
Cnrcumlne  8  (L.)  (A.) ;  DIreet  Yellow  J  (P.) ; 
Azidine  Fast  YeUow  G  (C.  J.) ;  Direct  YeUow  RT 
(CI.  Go.) ;  Dlnet  YeUow  F  (Sch.) ;  DIreet  YeUow 


G  (I.) ;  Direct  Y^ow  R  (P.)  (O.) ;  Diamine 
Fftst  YeUow  A  (0.).  Prepared  by  heatuig  p- 
nitrotoluenesulphonic  acid  with  aqueous  sodium 
hydroxide.  Direct  yellow  RT,  which  was 
analysed  by  Green  (/.c),  is  considered  to  have 
the  constitution: 

CHC,H,(SO,H)N=NC,H^SO,H)-CH 


(!jHC,H,i 


II 


(SO,H)N— NC,H,(SO,H)-CH 

V 

(the  colouring  matter  being,  of  course,  the 
sodium  salt). 

Aqueous  solution  is  brownish-yeUow.  Solu- 
tion in  sulphuric  acid  is  violet,  becoming  yellow 
on  dilution. 

Liter€Uure.—E,  P.  4387  of  1886 ;  D.  R.  P. 
38736;  F.  P.  176630;  A.  P.  360653;  BulL 
Mulhouse,  1887,  99 ;  Ber.  1886,  19,  3234. 

Naphthamlne  YeUow  G  (K.) ;  Direct  YeUow 
R  (By.) ;  •  Renol  YeUow  R  (T.  M.).  Prepared  as 
above,  but  the  temperature  of  the  reaction 
is  60*^-86°.  Reddish-yellow  aqueous  solution 
gives  brown  precipitate  with  excess  of  hydro- 
chloric acid  and  a  yeUow  precipitate  with 
sodium  hydroxide.  Solution  in  sulphuric  acid 
is  cherry-red,  becoming  yeUow  on  dilution. 

Literature.— E.  P.  23672  of  1892 ;  D.  R.  P. 
79241 ;  F.  P.  226636 ;  Ber.  1893,  26,  2233 ; 
1896  28  2281. 

MUcado  YeUow  (A.) ;  MUcado  YeUow  G  (L.) ; 
MUcado  Gold  YeUow  2  G,  4  G,  6  G,  8  G  (L.) ; 
Naphthamlne  YeUow  2  G,  8  G  (K.);  Renol 
YeUow  2  G  (T.  M.) ;  DIanfl  DIreet  YeUow  S 
(M.);  Formal  YeUow  (G.) ;  StUbene  YeUow  8  G 
(B.) ;  Paper  YeUow  (M.).  Prepared  by  treating 
the  products  of  condensation  of  p-idtrotoluene- 
sulphonic  acid  and  sodium  hydroxide  with 
oxidising  agente.  YeUow  aqueous  solution 
gives  a  brownish-yeUow  precipitate  with  hydro- 
chloric acid,  and  yellow  solution  or  precipitate 
with  sodium  hydroxida  Solution  in  sulphuric 
acid  is  orange  to  red,  becoming  yeUow  on 
dUution. 

Lit€rature,—E.  P.  23672  of  1892 ;  D.  R.  P. 
42466;  F.  P.  226636;  Ber.  1893,  26,  2234; 
1897,  30,  2618,  3097  ;   1898,  31,  364,  1078. 

Stilbene  YeUow  G,  4  G,  6  G,  8  G  (CI.  Co.). 
The  constitution  of  the  last  brand  has  already 
been  given.  The  colouring  matters  are  alkaline 
condensation  products  of  dinitrodibenzyldisnl- 

ghonic  acid,  and  dinitrostilbenedisulphonic  add. 
olution  in  sulphuric  acid  is  orange  to  yeUowish- 
red,  becoming  yellow  on  dUution. 

Literature.— E,  P.  6361,  21663,  21399,  of 
1897 ;  3393  of  1898 ;  D.  R.  P.  96107,  113613, 
113614;  F.  P.  272384,  273018,  273037;  Ber. 
1897,  30,  3097 ;  1898,  31,  1087. 

Diphenyldtronine  G  (G.).  Prepared  by  con- 
densing dinitrodibenzyldisulphonic  acid  with 
aniline  in  presence  of  sodium  hydroxide  or  by 
condensing  similarly  dinitrostilbenedisulphonic. 
acid.  YeUow  aqueous  solution  fives  a  browmsh- 
yellow  precipitate  with  hydrodiloric  acid,  and 
an  orange-yellow  one  with  sodium  hydroxide. 
Solution  in  sulphuric  acid  is  orange,  giving  a 
brownish-yeUow  precipitate  on  dilution. 

Literature.—E.  P.  18990,  21399,  21663  of 
1897 ;  D.  R.  P.  101760,  113614;  V,  P.  269466, 
273018  ;  A.  P.  613911. 

Dlphenyl   Fast  YeUow  (G.).    Prepared  by 


AZO-  COLOURING  MATTERS. 


491 


condensine  dimtrodibenzyldisalphonio  aoid  or 
dinitrostilbeQediaulphomo  aoid  with  primuline 
or  dehydrothio-p-toluidinesulphonic  acid  in 
presence  of  sodium  hydroxide.  Yellow  aqueous 
solution  ffiyes  a  bro^mish-orange  yellow  precipi- 
tate with  hydrochloric  acid,  and  an  oran^e- 
^eliow  one  with  sodium  hydroxide.  Solution 
m  sulphuric  acid  is  red,  giving  a  brownish- 
yellow  precipitate  on  dilution. 

Literaiure,-'E,  P.  18990,  21399,  21553  of 
1897 ;  D.  R.  P.  100613,  113614 ;  F.  P.  269466, 
273018. 

Mikado  Blrown  B,  8  GO,  M  (L.).  Prepared 
bv  the  action  of  alkalis  on  jj-nitrotoluenesul- 
phonic  acid  in  presence  of  oxidisable  substances. 
Brown  aqueous  solution  gives  a  brown  pre- 
cipitate with  hydrochloric  acid.  Solution  in 
smphuric  acid  is  violet-black,  giving  a  brown 
precipitate  on  dilution. 

Xttefo/ttre.— E.  P.  2664  of  1888 ;  D.  R.  P. 
46252,  48528;  F.  P.  189697;  A.  P.  395115, 
396527. 

Mikado  Orange  G  to  5  R  (L.) ;  Naphthamine 
Oraage  2  R  (K.) ;  Direet  Orange  G  (G.) ;  Chlor- 
amlne  Orange  G  (By.) ;  Stllliene  Orange  4  R 
ra.  Co.) ;  Stilbene  YeUow  8  G  (B.).  Prepared 
by  the  same  reaction  as  the  preceding,  and 
by  the  action  of  alkaline  reducing  agents  on 
direct  yellow.  Orange-yeUow  aqueous  solution 
gives  a  dark-brown  precipitate  with  hydro- 
chloric acid,  and  an  oranse  one  with  sodium 
hydroxide.  Solution  in  sulphuric  acid  is  violet 
to  blue,  giving  a  brown  precipitate  on  dilu- 
tion. 

Mikado  Orange  8  RO  (L.)  has  the  constitu- 
tion: 

CHC,H,(SO,H)N :  NC,H,(SO,H)CH 

II  II 

CHC,H,(SO,H)N :  NC  JH,(SO,H)CH 

Brands  4  RO  and  5  RO  are  redder  shades. 

Litmaure.—E.  P.  2664  of  1888 ;  D.  R.  P. 
46252,  48528,  96929;  F.  P.  189697;  A.  P. 
395115,  396527 ;  Ber.  1893,  26,  2233 ;  1895,  28, 
2281. 

Polyehromlne  B  (G.) ;  Fast  Cotton  Brown  R 
(Ci.);  Direct  Brown  R  (G.).  Prepared  bv 
boiling  equal  molecules  of  p-nitrotoluenesul- 
phonic  acid  and  p-phenylenediamine  with 
sodium  hydroxide.  Orange  -  brown  aqueous 
solution  gives  a  blue-black  precipitate  with 
hydrochloric  acid.  Solution  in  sulphuric  acid 
is  reddish-violet,  giving  a  bluish-black  precipi- 
tate on  dilution. 

Lt<ero<ttre.— E.  P.  15671  of  1890 ;  D.  R.  P. 
50290 ;  F.  P.  208626  ;  A.  P.  455952. 

Dlphenyl  Orange  RR  (G.) ;  Azidine  Orange  D 
2  R  (0.  J.).  Prepared  by  condensing  2  moLs.  of 
p-nitrotoluenesulphonic  acid  with  2  mols.  of 
p-phenylenediamme  in  presence  of  concentrated 
aqueous  sodium  hydroxide.  Orange  -  yellow 
aqueous  solution  gives  a  bluish-black  precipitate 
with  hydrochloric  acid,  and  an  orange  one  with 
sodium  hydroxide.  Solution  in  sulphuric  acid 
is  red,  giving  a  bluish-black  precipitate  on 
dilution. 

Literaiure.—lS^.  P.  6651  of  1899 ;  D.  R.  P. 
appl.  G.  13069 ;  F.  P.  286620  ;  A.  P.  636065. 

Chleago  Qnagt  G  (G.).  Prepared  by  con- 
densing p-nitrotoluenesulphonic  acid  with  benzi- 
dine in  presenoe  of  sodium  hydroxide.  Orange- 
yellow  aqueous  solution  gives  a  brown  precipi- 


tate with  hydrochloric  acid,  and  an  orange- brown 
one  with  sodium  hydroxide.  Solution  in  sul- 
phuric acid  is  violet,  giving  a  brown  precipitate 
on  dilution. 

Liieraiure,—E.  P.  788  of  1893;  D.  R.  P. 
75326  ;  F.  P.  227271. 

Amlea  YeUow  (G. ).  Prepared  by  condensing 
p-nitrotoluenesulphonic  acid  with  p-amino- 
phenol  in  presence  of  boiling  aqaeous  sodium 
hydroxide.  Brownish-yellow  aqueous  solution 
gives  a  brownish-black  precipitate  with  hydro- 
chloric acid.  Solution  in  sulphuric  acid  is 
violet,  giving  a  dark-brown  precipitate  on 
dilution. 

Literature,^¥.  P.  222554. 

Dlphenyl  ChrysoiHe  G  (G.).  Prepared  by 
ethylating  the  preceding.  The  constitution  is 
probably 

CHC,H,(SO,Na)N :  N-C.H^OCjH. 

II 

CH<:5,H,(S0,Na)N :  NC.H^O-C.H, 

Golden-yellow  aqueous  solution  gives  a  blackish- 
brown  precipitate  with  hydrochloric  acid,  and  an 
orange  one  with  sodium  hydroxide.  Solution 
in  sulphuric  acid  is  violet-red,  giving  a  blackish- 
brown  precipitate  on  dilution. 

Literature.— E,  P.  6651  of  1899;  D.  R.  P. 
appl.  G.  7525,  13069;  F.  P.  286620;  A.  P. 
636065. 

Dlphenyl  Chrysoitie  RR  (G.).  Prepared  by 
diazotising  diphenyl  orange  RR  (G.),  combining 
the  diazo-  compound  with  phenol  and  ethylating 
the  product.  Keddish-orange  aqueous  solution 
gives  a  blackish-brown  precipitate  with  hydro- 
chloric acid,  and  a  reddish-brown  one  with 
sodium  hydroxide.  Solution  in  sulphuric  add 
is  pure  blue,  giving  a  brownish-black  precipi- 
tate on  dilution. 

Literature,— E.  P.  6651  of  1899;  D.  R.  P. 
117729;   F.  P.  286620;   A.  P.  644462. 

Diphenyl  Fast  Brown  G  (G.).  Prepared  as 
the  preceding,  but  the  diazo-  compouna  is  com- 
bined with  7-phenylamino-a-naphthol-3-sul- 
phonic  acid.  The  dark  yellowish-brown  aque- 
ous solution  gives  a  blackish-brown  precipitate 
with  hydrocluoric  acid,  and  a  dark-brown  one 
with  sodium  hydroxide.  Solution  in  sulphuric 
acid  is  dark  blue,  giving  a  blackish-orown 
precipitate  on  dilution. 

Referenced  as  above. 

Diphenyl  Cateehlne  G  (G.).  Prepared  as 
above,  but  the  diazo-  compound  is  combined 
with  7  -  dimethylamino  -  a  •  naphthol-3-8ulphonio 
acid.  Yellowish-brown  aqueous  solution  gives 
a  dark-brown  precipitate  with  hydrochloric  aoid, 
and  a  brown  one  with  sodium  hydroxide. 
Solution  in  sulphuric  acid  is  blackish  violet-blue, 
giving  a  blackish-brown  precipitate  on  dilution. 

References  as  above. 

Cureaphenlne  (CI.  Co.).  Prepared  by  con- 
densing p-nitrotoluenesulphonic  acid  with  de- 
hydrotnio-;>-toluidinesulphoiiic  acid  in  presence 
of  very  dilute  aqueous  sodium  hydroxide. 
Yellow  aqueous  solution  gives  a  brown  precipi- 
tate with  hydrochloric  acid.  The  solution  in 
sulphuric  acid  is  red,  giving  a  brownish-yellow 
precipitate  on  dilution. 

Literature,— E.  P.  12922  of  1896 ;  D.  R.  P. 
99576  ;   F.  P.  264756. 

Chlorophenlne  Orange  (various  marks)  (G.  Co.) 
are  reduction  products  of  the  preceding. 


492 


AZO-  COLOURING   MATTERS. 


IV.  Tbis-^o-  Goloubino  BIattxbs. 


These  colouis,  as  their  name  implies,  contain 
three  aKO-gronps. 
Janiu  Brown  B(B1): 

l^(CH,),ClC,H4'N,Ci0H,N,C,H,(NH^,N,C,H, 

Prepared  by  combining  diazotised  m-amino- 
phenyltrimethylammonium  chloride  with  a- 
naphthvlamine,  diazotising  the  product  and 
combimng  with  chrysoidine.  AqueouB  solution 
is  brown,  giving  a  soluble  brown  precipitate  with 
hy(hochloric  acid  or  sodium  hydroxide.  Solu- 
tion in  sulphuric  acid  is  dark  green,  becoming 
brown  on  dilution. 

LUerature.—K  P.  9343  of  1896;   D.  R.  P. 
95630. 


Janus  Brown  R  (K.)  is  prepared  firom  diazo- 
9d  p-aminobenzyidiethylanune  a 
thylaznine,  the  product  being  diazotised  and 


and  a-naph- 


combined  with  chrysoidine,  resorcinol,  or  m- 
phenylenediamine.  Reactions  are  similar  to 
those  given  by  the  preceding  colour. 

IMerttture.—l&.  P.  19976  of  1896 ;  D.  R.  P. 
99127  ;  F.  P.  256156  ;  A.  P.  610345 ;  see  also 
D.  R.  P.  93499,  100420 ;  F.  P.  264679 ;  A.  P. 
602638,  602639,  602640,  623697,  626913. 

Mdogene  Blue  BH  (K.  S.) ;  Diamine  Beta 
Black  {0,y. 

^  ^.H,-N,-C,oH.(SO,H),(OH)NH, 
^•<«^Ci,H,N,(5ioH,(SO,H),(OH)NH, 

TetrazotSsed  benzidine  is  combined  with  1  mol. 
of  p-xylidine,  the  product  diazotised  and  com- 
bined with  2  mols.  of  8-amino-a-naphthol-3  :  6- 
disulphonio  acid  (H-acid).  The  violet-blue 
aqueous  solution  ffives  a  violet  precipitate  with 
hydrochloric  acid,  and  becomes  violet  with 
sodium  hydroxide.  The  solution  in  sulphuric 
acid  is  blue,  giving  a  bluish-violet  precipitate 
on  dilution. 

LUeraturC'-B.  P.  28810  of  1896;  F.  P. 
262109 :  A.  P.  591616. 

DiaEO  Bine  Blaek  RS  (By.) : 

jj  ^,oH.N,CioH,(SO,H),(OH)NH, 
^•<^Ci,H,N,CioH^SO,H),(OH)NH, 

Tetrazotised  benzidine  is  combined  with  1  mol. 
of  a-naphthylamine,  the  product  diazotised  and 
combined  with  2  mols.  of  H-acid.  The  dark 
blue  aqueous  solution  gives  a  blue  precipitate 
with  hydrochloric  acid,  and  becomes  redder  with 
sodium  hydroxide.  The  solution  in  sulphuric 
acid  is  dark  bluish-green,  giving  a  blue  precipitate 
on  dilution. 

Dlroet  Blaek  V  and  RR  (P.)  are  analogous 
colours  derived  from  benzidine,  8-ainino-a- 
naphtholsulphonic  acid,  a  primary  amine,  and  a 
m-diamine. 

Benzo  Gray  S  extra  (By.)-. 

N  ^ioH,N,<:Jii,(SO^OH 
^«\CMHgN,C,H,{CO,H)OH 

The  colouring  matter  from  tetrazotised  benzidine 
and  1  mol.  each  of  salicvlic  acid  and  a-naphthyl- 
amine  is  diazotised  and  combined  with  a-naph- 
thol-4-sulphonio  acid.  The  Bordeaux-brown 
aqueous  solution  gives  a  black  precipitate  with 
hydrochloric  acid.  The  solution  in  sulphuric 
acid  is  blue,  giving  a  black  precipitate  on 
dilution. 

Literature.— E.  P.  13235  of  1890 ;  D.  R.  P. 
67331 ;  F.  P.  187366. 


Benzo  Olive  (By.) : 


NH, 


N  ^ioH,N,-OioH,(SO,H),(OH)- 
^  «\Ci,H.N,O,H,(C0^)0H 

Prepared  as  the  preceding,  except  that  8>ainino- 
a-naphthol-3 : 6-ai8ulphoiiio  acid  (H-aoid)  is 
used  as  the  end  component.  The  dark  moss- 
green  aqueous  solution  gives  a  blackish-grey 
precipitate  with  hydrochloric  add,  and  becomes 
daik  brown  with  sodium  hydroxide.  Solution 
in  sulphuric  acid  is  violet,  giving  a  greenish- 
black  precipitate  on  dilution. 

Literature,— E.  P.  3439  of  1891 ;  D.  R.  P. 
66480  ;  F.  P.  187365. 

Congo  Fait  Blue  R  (A.) ;  Benio  Fast  Blue  R 

(By.) : 

J,  .,.x-OioH,-N,CwH-(80,H).-OH 
^*v^CuH,,lf,-C,oH4(SO,H),OH 

Tolidine  is  tetrazotised  and  combined  with 
1  mol.  of  a-naphthylamine,  the  product  diazo- 
tised and  combined  with  2  mols.  of  a-naphthol- 
3  :  8-disulphonic  acid  (c-add).  The  blue  aqueous 
solution  IS  precipitated  with  acids  or  alkalis. 
The  solution  in  sulphuric  acid  is  blue,  giving  a 
blue  precipitate  on  dilution. 

Literature.— E.  P.  6932  of  1890;  D.  R.  P. 
60921 ;  F.  P.  205616. 

Benzo  Blaek  Bine  R  (By.) : 

jj:  ^,oH,N,-CioH,(SO,H)OH 
^»\.CuHi,N,CioH,(SO,H)-OH 

Tolidine  is  tetrazotised  sad  combined  with 
1  mol.  of  a-naphthyUmine  and  the  intermediate 
product  diazotised  and  combined  with  2  mols. 
of  a-naphthol-4-sulphonic  add.  Bluish-violet 
aqueous  solution  gives  a  violet  predpitate  with 
hydrochloric  add.  Solution  in  sulphuric  add 
is  blue,  giving  a  bluish-violet  predpitate  on 
dilution. 

Literature.— E.  P.  16484  of  1887;  F.  P. 
187365;  A.  P.  440639. 

Benzo  Indigo  Blue  (By.) : 

N  ^ioH,N,-CtoH*(SO,H)(OH), 
^«<^C,4H|,N,-C,A(80,H)(OH), 

* 

The  same  intermediate  tetrazo-oompound  as 
above  is  combined  with  2  mols.  of  1 : 8-di- 
hydroxynaphthalene-4-sulphonic  add  (S-acid). 
The  violet  aqueous  solution  gives  a  bluish- violet 
precipitate  with  hydrochloric  add,  and  becomes 
reddish- violet  with  sodium  hydroxide.  Solution 
in  sulphuric  acid  is  greenish-blue,  giving  a  violet- 
blue  precipitate  on  dilution. 

Uleraiure.—E.  P.  13665  of  1889 ;  D.  R.  P. 
57912  ;  F.  P.  200620 ;  A.  P.  601118. 

Congo  Fast  Blue  B  (A.) ;  Benzo  Faat  Blue  B 

(By.) : 

^  ,.^ioH,N,Cj,H4(SO,H),OH 
^«'\0uH„O,N,CipH^(SO,H),-OH 

Diamsidine  is  tetrazotised  and  combined  with 
1  mol.  of  a-naphthylamine  and  the  intermediate 
product  diazotised  and  combined  with  2  mols. 
of  a-naphthol-3 : 8-disulphonio  acid  (c-add). 
Blue  aqueous  solution  gives  a  blue  preidpitate 
with  adds  or  alkalis.  Solution  in  sulphuric 
acid  is  cornflower  blue,  giving  a  blue  precipitate 
on  dilution. 

Literature.— E.  P.  6932  of  1890;  D.  R.  P. 
57444 ;  F.  P.  206615. 

Colombia  Blaek  FB  and  FF  eztra  (A.); 
I  Azldlne  Blaek  FF  {0.  J.) ;  Titan  Biaeki  (H.) ; 


AZO-  COLOURING  MATTERS. 


493 


DIanolB]aekFB,FF(LeT.);  Pmama  BUek  R,  F 
(Sch.) ;  Patent  Dlanil  Blaek  FF  extra  (M.) : 

*'«<v.C,oH4(80,H)(OH)-N,-0,H,(NH,), 

p-Aminoaoetanilide  is  diazotised  and  oombined 
with  7-amixio-a-naphthol-3-Biilphonio  aoid  (7- 
aoid)y  the  prodaot  Baponiiiea  with  sodium 
hydroxide,  the  resulting  diamino-compound 
tetrazotised  and  oombined  first  with  1  mol.  of 
a-naphthylamine-G-  (or  7)-sulphonic  acid  (Cleye^s 
adds)  and  then  with  1  mol.  of  m-phenylenedi- 
amine.  The  aqueous  solution  is  violet-blaok, 
and  is  precipitated  by  acids  or  alkalis.  Solution 
in  sulphune  acid  is  blue,  giving  a  precipitate 
on  dilution. 

Literaiure,—E.  P.  12804  of  1900;  D.  R.  P. 
131986,  131987  ;  F.  P.  302499 ;  A.  P.  679221. 

Direet  Blaek  BMP  (P.)  has  the  same  or  a  very 
similar  constitution,  and  dvestuffs  belonging  to 
the  same  class  are  Carbon  Biaeks  (various  marks) 
(K.),  and  Ni^hthamlno  Direet  Blaeks  FF,  B, 
FG  and  CS  (K.j.  They  are  of  the  type  desoribed 
in  D.  R.  P.  126671,  viz.  i^-nitroaniline-o-sulphonio 
aoid  is  diazotised  and  combined  with  Gleve's 
acids,  the  product  reduced,  tetrazotised  and 
combined  with  2  mob.  of  a  meta-diamine. 

Titan  Black  J  (H.): 

^  ^xK5,H--N,C,pH.(S0,H)-NH, 
^»<v,CioH4(S04l)(OH)N,-C,H,(NH,), 

p-Aminoaoetanilide  is  diazotised  and  combined 
with  6-amino-a-naphthol-3-Bnlphonio  add  (J- 
add),  the  product  saponified,  tetrazotised,  and 
oombined  with  1  mol.  each  of  a-naphthylamine- 
6-(or  7)-sulphonic  add  (Cleye's  acids)  and  m- 
phenylenediamine. 

Oxydlamine  Blaek  N  (G.) : 

-  ^C,H4-N,-0,oH.(SO,H)(OH)NBL 
"•\C,oHi(80jS)(OH)N,C,H,(NH,), 

Prepared  like  Columbia  black  FB,  except  that 
7-amino-a-naphthol-3-sulphonic  aoid  (^-acid)  is 
used  instead  of  deve's  add.  Blue- black  aqueous 
solution  gives  a  black-violet  predpitate  with 
hydrochloric  acid,  and  a  red-violet  one  with 
sodium  hydroxide.  Solution  in  sulphuric  add 
is  ffreenish-blue,  giving  a  violet-olack  pre- 
dpitate on  dilution. 

LUerature.—A.  P.  526763. 

bodlphenyl  Blaek  R  (O.) : 

,^  ^^x<J,H.N,C,H,(OH), 
^»^\0i,H4(S0,H)(0H)N,-C,H,(NH,), 

Prepared  as  Columbia  black  FB,  except  that 
resorcinol  is  used  instead  of  Cleve*s  add.  Violet- 
black  aqueous  solution  gives  a  black  precipitate 
with  acids  or  alkalis.  Solution  in  sulphuric 
add  is  bladdsh-blue,  giving  a  black  precipitate 
on  dilution. 

Xtlemltfff.—E.  P.  20278  of  1897;    F.  P. 
270161 ;  A.  P.  616497. 

Dlieet  Blaek  V  (K.  a) ;  Dlaio  Dlreel  Blaek 
(Wiescher  ft  Co.): 

N  ^taH,(SO,H),(OH)N,-0,oH.-NH, 
'*«\C„H,-N,-0,oH4(SO,H)(OH)NH, 

7.Amino-a-naphthol-3 : 6-disulphonic  add  (2  R- 
add)  is  diazotised  and  oombined  with  1  mol.  of 
ci-naohthylamine  in-  add  solution.  The  mono- 
aso-c^ytstnff  is  then  dissolved  by  addins  sodium 
hydroxide  and  tetrazotised  benzidine  added,  the 
combination  being  effected  in  presence  of  sodium 


carbonate.  To  this  intermediate  product  is  then 
added  1  mol.  of  7-amino-«-naphthol-3-sulphonio 
add  (y-aoid).  Violet-black  aqueous  s^ution 
gives  a  blue-black  precipitate  with  hvdrochlorio 
add,  and  becomes  reddish-violet  with  sodium 
hvdroxide.  Solution  in  sulphuric  add  is 
blue,  giving  a  blue-black  precipitate  on  dilution. 

Literature,— E.  P.  16294  of  1896 ;  D.  R.  P. 
109161 ;  F.  P.  266960 ;  A.  P.  601033. 

Direet  Indone  Bine  R  (K.  S.) : 

J.  ^,oH,(SO,H),(OH)N,-C,oH.-NH, 
^«\Ci,H/N,CioH,(SO,H),(OH)NH, 

Prepared  as  the  preceding,  except  that  8-amino- 
a-naphthol-3 : 0-disulphonio  add  (H-add)  is 
used  as  the  end-component.  Blue- black  aque- 
ous solution  gives  a  dark-blue  predpitate  with 
hydrochloric  acid,  and  becomes  violet  with 
sodium  hydroxide.  Solution  in  sulphuric  acid 
is  blue,  giving  a  dark-blue  precipitate  on 
dilution. 

References  as  above. 

Diamine  Bronze  G  (C.) : 

N  ^ioH,(SO,HUOH)-N,CA(NH,), 
^  »\Cx,H,N,C,H,(CO,H)OH 

The  dyestuff  from  tetrazotised  benzidine  and 
1  mol.  each  of  salicylio  acid  and  8-ainino-a- 
naphthol-3  :  6-disulphonio  acid  (H-add)  is  diaeo- 
tised  and  combined  with  1  mol.  of  m-phenylene- 
diamine.  The  chocolate-brown  aqueous  solu- 
tion ^ves  a  purple-brown  predpitate  with  hydro- 
chloric acid,  and  becomes  vellower  with  sodium 
hydroxide.  Solution  in  sulphuric  add  is  bluish- 
violet,  giving  a  black  precipitate  on  dilution. 

Literature,— E.  P.  6972  of  1891 ;  D.  R.  P. 
76762  ;  F.  P.  201770. 

Trisolphone  Browns  B,  G'  and  GG  (K.  8.). 
These  are  constituted  simihurly  to  the  preoedinff, 
except  that  7  -  amino  -  a  -  naphthol  -3:6-  disuS- 
phonic  acid  (2  R-acid)  is  employed  instead  of 
H-acid.  The  diamines  used  are  benzidine 
(for  B),  tolidine  (for  G),  and  dianisidine  (for  GG). 
Each  brand  gives  a  brown  solution  in  water, 
which  vields  a  blackish-brown  precipitate  with 
hydrochloric  acid,  and  becomes  red  with  sodium 
hvdroxide.  The  solution  in  sulphuric  acid  is 
bluish-violet,  giving  a  dark-brown  predpitate 
on  dilution. 

Literature.— E,  P.  6746  of  1898 ;  D.  R.  P. 
114638  ;  F.  P.  276733  ;  A.  P.  608024. 

Chlorazol  Deep  Brown  B  (H.) : 

^•\Ci,HgN,C,H,(CO,H)OH 

Benaidine  is  tetrazotised  and  oombined  with 
1  mol.  each  of  salioylio  acid  and  7-amino-a-naph- 
th^-3 : 6-disulphonio  add  (2  R-add),  the  pro- 
duct being  diazotised  and  combined  with  ta- 

t^l  jrlAti  aH  i  ft.fnm<t, 

OoliimbtonaekR(A.): 

Tolidine  is  tetrazotised  and  combined  with  1  moL 
eaoh  of  7-ainino-a-naphthol-3 : 6-diBulphonio 
add  (2  R-acid  and  m-toiylenediamine,  and  the 
product  is  diazotised  and  combined  with  m- 
tolylenediamine.  Brown-black  aqueous  solu- 
tion gives  a  black  precipitate  with  hydrochloric 
acid,  and  becomes  brown  with  sodium  hy- 
droxide. Solution  in  sulphuric  acid  is  pure  blue^ 
giving  a  violet-black  precipitate  on  dilution. 


494 


AZO-  COLOURING  MATTERS. 


Literature.— E,  P.  14896  of  1893 ;  D.  R.  P. 
102815 ;  F.  P.  231976. 

Columblft  Blaek  B  (A.) ;  ntan  BUek  M  (H.) ; 
INreet  Blue  Blaek  B,  2  B  (B^.)-  Prepaied  as  the 
preceding,  except  that  dianuidme  is  used  instead 
of  beiizi<une.  The  violet-black  aqueous  solution 
gives  a  dark  flocoulent  precipitate  with  hydro- 
ohlorio  acid,  and  becomes  roddish-violet  with 
sodium  hydroxide.  Solution  in  sulphuric  acid 
is  blue-black,  giving  a  violet-black  precipitate  on 
dilution. 

Literaiure.—E.  P.  14895  of  1893 ;  D.  R.  P. 
111744;  F.  P.  231976. 

Ck>liimbla  BUeks  2  BX  and  2  BW  (A.)  belong 
to  the  same  class. 

BiDio  Blaek  Blue  G  (By.) : 

N  ^,oH.N,-C,oH,(SO,H)lOH 
^«*^Cj,H,(SO,H),N,0,oH,(SO,H)-OH 

Benzidinedisulphonio  acid  is  tetrazotised  and 
combined  with  1  mol.  of  a-naphthylamine,  the 
product  diazotised  and  combined  with  2  mols. 
of  a-naphthol-4-sulphonic  acid.  The  blue-black 
a(|ueous  solution  gives  a  black-blue  precipitate 
with  hydrochloric  acid,  and  becomes  blue  with 
sodium  hydroxide.  The  solution  in  sulphuric 
acid  is  blackish-green,  giving  a  blaokisn-blue 
precipitate  on  dilution. 

Ltterature,—E.  P.  16484  of  1887 ;  D.  R.  P. 
44779 ;  Ber.  1889,  22,  3463. 

Benco  Blaek  Blue  5  G  (By.).  As  the  pre- 
ceding, except  that  1 :  8-dihyaroxynaphthalene- 
4-sulphonio  acid  is  used  instead  of  a-naphthol- 
4-sulphonio  acid.  The  blackish-blue  aijueous 
solution  ffives  a  dark  ffreemsh-blue  precipitate 
with  hydrochloric  acid.  The  solution  in  sul- 
phuric acid  is  black-sreen,  giviiig  a  dark  greenish- 
olue  precipitate  on  dilution. 

Columbia  Green  (A.) ;  Direct  Green  CO  (L.) : 

N,C„H„-N,C,H,(CO,H)-OH 
(!'ioHt(SO,H)(OH)NH, 

N,C,H,-SO,H 

Benzidine  is  tetrazotised  and  combined  with 
1  mol.  of  salicylic  acid,  and  the  intermediate 
product  is  combined  in  alkaline  solution  with 
the  product  of  the  action  of  diazotised  sul- 
phanilic  acid  on  8-amino-a-naphthol-5-8ulphonio 
acid  (S-acid)  in  acid  solution.  The  green 
aqueous  solution  gives  a  green  precipitate  with 
hydrochloric  acid,  and  becomes  greenish-black 
with  sodium  hydroxide.  The  solution  in  sul- 
phuric acid  is  blue-violet,  giving  a  green  pre- 
cipitate on  dilution.  When  diazotised  aniline 
is  used  instead  of  diazotised  sulphanilio  acid 
in  the  above,  Columbia  Blaek  Green  D  (A.)  is 
produced. 

Literahire.—D,  R.  P.  appl.  A.  3574. 

Diamine  Green  B  (C);    Dlanol  Green  B 

iLev.) ;  Renol  Green  B  (T.  M.) ;  DIreet  Green 
)N  (P.) ;  Azidlne  Green  2  B  (G.  J.) ;  DlanO 
Green  B  (M.);  Alkali  Green  (D.);  Diamine 
Green  B  (B.) : 

Ni-CiiHgNjCH^OH 

CioH,(SO,H),(OH)NH, 

N.-CgH^-NO, 
Pxepared  in  a  similar  manner  as  the  preceding. 


Tetrazotised  benzidine  is  comjtined  with  1  mcL 
of  phenol  and  the  product  is  combined  with  the 
azo-colour  from  diazotised  p-nitroaniline  and 
8-amino-a-naphthol-3  : 6-di8ulphonic  acid  (H- 
acid).  DuU-green  aqueous  solution  gives  a 
bluish-black  precipitate  with  hydrochloric  acid, 
,  and  becomes  yellower  with  sodium  hydroxide. 
Solution  in  sulphuric  acid  is  violet,  giving  a 
black  precipitate  on  dilution. 

Liter€Uure.—E.  P.  16725  of  1891 ;  D.  R.  P. 
66351 ;  F.  P.  201770;  A.  P.  514599. 

Diamine  Green  G  (C.) ;  Chloraiol  Green  G 
(H.) ;  Dlanol  Green  G  (Lev.) ;  Azidlne  Green 
2  G  (0.  J.);  AlkaU  Green  D  (D.);  DiaoU 
Green  BBN,  G  (M.) ;  Benzoin  Dark  Green  (B.  K.) ; 
Erie  Direct  Green  MT,  BT  (Sch.);  Oxamine 
Green  G  (B.).  Prepared  as  the  preceding,  except 
that  salicylic  acid  is  used  instead  of  phenol. 

Reactions  and  literature  as  above. 

Eboll  Green  (various  marks)  (L.).  Tetrazo- 
tised benzidine  combined  with  1  mol.  of  salicylic 
acid  is  combined  with  the  product  of  the  action 
of  diazotised  sulphanilic  acid  on  8-amino-a- 
naphthol-4  : 6-diBulphonic  acid. 

Literature.— E,  P.  19253  of  1895 ;  D.  R.  P. 
appl.  F.  8626 ;  A.  P.  606439. 

DIphenyl  Green  G  (O.).  Prepared  like 
diamine  ^reen  B  (above),  except  that  o-chloro- 
p-nitroandine  is  used  instead  of  i>-nitroaniline. 
The  reactions  are  also  similar  to  those  given  by 
this  colour. 

Literature.— A.  P.  628233. 

DIphenyl  Green  8  G  (G.).  Prepared  like 
diamine  green  G,  o-chloro-p-nitroanuine  being 
used  instead  of  p-nitroaiiiline.  The  green 
aqueous  solution  gives  a  creen  precipitate  with 
hydrochloric  acid,  and  becomes  duller  with 
sodium  hydroxide.  Solution  in  sulphuric  add 
is  reddish- violet,  giving  a  green  precipitate  on 
dilution. 

Reference  as  the  preceding. 

Chloramlne  Green  B  (K.  S.).  Prepared  like 
diamine  green  B,  2  : 5-dichloroaniline  being  used 
instead  of  p-nitroaniline.  The  green  aqueous 
solution  gives  a  violet-black  precipitate  with 
hydrochloric  acid,  and  becomes  olack-ffreen 
with  sodium  hydroxide.  Solution  in  sulphuric 
acid  is  violet,  giving  a  violet-black  precipitate 
on  dilution. 

Literature.— E.  P.  8503  of  1899 ;  D.  R.  P. 
112820 ;  F.  P.  287971 ;  A.  P.  627679. 

Chloramlne  Blaek  N  (K.  S.).  Tetrazotised 
benzidine  is  combined  with  1  mol.  of  m-phenylene- 
dianiine  and  the  product  oombinea  with  the 
azo-colour  from  diazotised  2  : 5-dichloroaniline 
and  H-acid.  The  dark  bluish-green  aqueous 
solution  gives  a  blue  precipitate  with  hydro- 
chloric acid,  and  a  bluiui-f^reen  precipitate  irith 
sodium  hydroxide.  Solution  in  sulphuric  acid 
is  blue,  giving  a  blue  precipitate  on  dilation. 

Chtoramine  Bine  HW  (K.  B.y 


N,Ci^.N,'CioH4(SO,H)(OH)NH» 
ipH,(SO,H),(OH)NH, 


J.: 


Tetrazotised  benzidine  is  combined  with  1  moL 
of  7-acid  in  alkaline  solution  and  then,  also  in 
alkaline  solution,  with  the  product  of  the  action 
of  diazotised  2 : 5-dichloroaniline  on  H-aoid 
(1  mol.)  in  acid  solution. 


AZO-  COLOURING  MATTERS. 


4d6 


Ghloramlne  Btae  8  G  (K.  S.) : 

N,C,AN,C.oH,(80,H),(OH)NH, 


A, 


,H,(SO,H),(OH)NH, 


TetnusotJBed  benzidine  is  combined  with  1  mol. 
of  8-amino-a-naphthol*3  :  6-diBulphonic  acid  (H- 
acid)  and  then  with  I  mol.  of  H-aoid  to  which 
has  been  added  1  mol.  of  diazotiBed  dichloro- 
aniline  in  acid  solution. 

References  for  the  last  two'  colours  as  for 
chloramine  green  B. 

Erie  Dlreet  Blaek  OX  (Soh.) ;  Reno!  Blaek  G 
(T.  M.) ;  Patent  DlanU  Blaek  EB  (M.) ;  Union 
Blaek  (By.);  Dlreet  Deep  Blaek  EW  (By.); 
Cotton  Blaek  RW  <B.) : 

^^KJ,oH,(SO,H),(OH)(NH,)N,C,H, 

Tetrazotised  benzidine  is  combined  with  1  mol* 
of  H-acid  in  aoid  solution,  after  making  alkaline 
1  mol.  of  diazotised  aniline  is  added,  and  then 
1  mol.  of  m-phenylenediamine.  When  m- 
tolylenediamine  is  used  in  the  last  combination 
the  colour  is  known  as  Erie  Dlreet  Blaek  RX 
(Sch.) ;  Renol  Blaek  R  (T.  M.) ;  Patent  Dlanll 
Bla^  EBV  (M.) ;  Dlreet  Deep  Blaek  RW  (By.) ; 
Cotton  Blaek  E  (B.).  The  aqueous  solutions  of 
both  dyes  become  violet  with  hydrochloric  acid 
and  blue  with  sodium  hydroxide  and  the  sul- 
phuric acid  solutions  are  violet  blue.  With 
phenol  as  end  component  Erie  Dlreet  Green  ET 
(Soh.)  is  obtained.  The  ereen  aqueous  solution 
becomes  blue  with  hvdrochloric  acid  and  greenish 
black  with  sodium  hydroxide.  The  solution  in 
sulphuric  acid  is  bluish-green,  becoming  blue 
on  dilution. 

LttmUure,—^.  P.  12305  of  1902 ;  D.  R.  P. 
153567  and  appl.  A.  8974  ;  F.  P.  321626 ;  A.  P. 
088478,  717560. 

Diamine  Blaek  HW  (C.) ;  Ingrain  Blaek  G 
(H.);  Maphthamlne  Blaek  H  (K.) : 

N,C„H.-N,CioH4(SO,H)(OH)-NH, 
C,JH,(SO,H),(OH)NH, 

N.-CgH^NO, 

Prepared  like  diamine  green  B  (above),  except 
that  7-amino-a-naphthol-3-sulphonio  acid  (7- 
acid)  is  used  inst^ead  of  phenol.  Blackish- blue 
aqueous  solution  gives  a  blue  precipitate  with 
hvdrochloric  acid.  Solution  in  sulphuric  acid  is 
blue,  giving  a  blue  precipitate  on  dilution. 

Liieraiure,—E.  P.  16725  of  1891 ;  D.  R.  P. 
66351, 70393  ;  F.  P.  201770 ;  A.  P.  514599. 

Dlanll  Blaek  R  (M.) : 


N,Ci,H.-N,-C,H,(NH,), 
,^^80,H),(0H), 


N,-Ci.H,SO,H 

Tetrazotised  benzidine  is  combined  with  1  mol. 
of  m-phenylenediamine  and  then  with  1  mol.  of 
1:8-  dihydroxynaphthalene-3  :  6  -  disulphonic 
add  (ohromotrope  acid),  to  which  has  been  added 
1  mol.  of  diazotised  naphthionio  acid.  The 
reddish-violet  aqueous  solution  ffivee  a  precipi- 
tate with  hydrochloric  acid,  and  becomes  blue 
with  sodium  hydroxide.    Solution  in  sulphuric 


acid  is  dark  blue,  giving  <a  reddish- violet  pre- 
cipitate on  dilution. 

Literature.— D.  R.  P.  89285. 

Congo  Brown  G  (A.)  (Lev.);  Naphthamlne 
Brown  4  G  (K.) ;  Benioln  Brown  C  (B.  K.) ; 
Dlreet  Brown  GR  (Sch.) : 

N,-Ci,H,N,C,H,((X),H)-OH 


(i 
J 


.H,(OH), 


N,C,H4S0,H 

The  dyestuff  from  tetrazotised  benzidine, 
salicylic  acid  and  reeorcinol  is  treated  with 
diazotised  sulphanilic  aoid  or  the  intermediate 
product  from  tetrazotised  benzidine  and  1  mol. 
of  salicylic  acid  is  combined  with  1  mol.  of 
resoroinol  to  which  1  mol.  of  diazotised  Sulphan- 
ilic aoid  has  been  added.  The  red  aqueous 
solution  gives  a  brown  precipitate  with  hvdro- 
chloric acid.  Solution  in  sulphuric  acid  is 
reddish-violet,  giving  a  reddish-brown  pre- 
cipitate on  dilution. 

LUerature.—E.  P.  10653  of  1888 ;  D.  R.  P. 
46328,  46601 ;  F.  P.  192331 ;  A.  P.  399581. 

Congo  Brown  R  (A.)  (Lev.) : 


N,0i,H,N,C,H^COjH)OH 
.H.(OH), 


(J 

N,C,oH,SO,H 

Prepared  as  the  preceding,  except  that  a-naph- 
thyIamine-6-sulphomc  acid  (Laurent's  aoid)  is 
used  instead  of  sulphanilic  acid.  Reactions  and 
references  as  the  preceding. 

Benzamine  Brown  3  GO  (D.)  is  prepared  as 
Congo  brown  G,  except  that  m-phenylenediamine 
is  used  instead  of  resoroinol.  The  reddish- 
yellow  aqueous  solution  gives  a  brown  precipi- 
tate with  hydrochloric  acid,  and  becomes 
brownish-fellow  with  sodium  hydroxide. 
Solution  m  sulphuric  acid  is  brownish -violet, 
giving  a  brown  precipitate  on  dilution. 

Azo  Corinth  (0.) : 

N,-Ci4Hi,N,-C,H,(S0,H)(0H)NH, 


•H,(OH), 


N.CioH.SO.H 

Tetrazotised  tolidine  is  combined  with  1  mol. 
of  3-aminophenol-6-sulphonic  acid  (acid  III.) 
and  1  mol.  of  resoroinol,  and  the  colouring  matter 
so  obtained  is  treated  with  1  mol.  of  duzotised 
naphthionic  acid.  Reddish-brown  aqueous  solu- 
tion gives  a  reddish-brown  precipitate  with 
hydrochloric  acid,  and  is  turned  bluish-red  with 
sodium  hydroxide.  Solution  in  sulphuric  acid 
is  bluish-violet,  giving  a  reddish-brown  precipi- 
tate on  dilution. 

LUeraiurc—E,  P.  13402  of  1893 ;   D.  R.  P. 
71182;  A.  P.  516381. 

V.  Tbtbakisazo-  Coloubtno  Mattbbs. 

These  contain  four  azo-groups. 
Benzo  Brown  G  (By.)  (Harden,  Orth  and 
Hastings  Corporation) : 

C  H.^N,C,H,(NH,),N.C.H,SO,H 
^•^•^<N,C,H,(NH,),N,C,H4S0aH 

Prepared  by  the  action  of  diazotised  sulphanilic 
acid  (2  mols.)  on  Bismarck  brown  (1   mol.). 


496 


AZO.  COLOURING  MATTERS. 


Reddish-brown  aqueouB  solution  gives  a  brown 
precipitate  with  acids  and  alkalis.  Solution  in 
sulphuric  add  is  violet-brown,  giving  a  brown 
precipitate  on  dilution. 

lAUnUure,—E,  P.  16493  of  1887 ;  D.  R.  P. 
46804 ;  A.  P.  384316. 

Benzo  Brown  B  (By.): 

C  H  ^N,CH,(NH,),N,C,^,SO,H 
^•***\^N,C,H,(NH,),N,-C,oH,SO,H 

Prepared  as  the  preoedinff,  except  that  naph- 
thionio  acid  is  used  insteaa  of  sulphanilio  acid. 

Reactions  and  references  as  above. 

Direet  Brown  J  (I.).  Prepared  as  bento 
brown  G,  except  that  aminobenzoio  acid  is  used 
instead  of  sulphanilio  add.  The  yellowish 
brown  aqueous  solution  gives  a  dark  brown 
predpitate  with  hydrochloric  add.  Solution 
in  sulphuric  add  is  orown,  giving  a  brown  pre- 
dpitate on  dilution. 

Literature.— D.  R.  P.  76127  ;  F.  P.  219925 ; 
A.  P.  491422. 

Toluylone  Brown  R  (0.);  Aildino  Brown 
T2R(C.  J.);  Dlroet Brown R (Sch.) : 

WRft  -r  H  ^^^••C,H,(NH,),N,CioH,SO,H 
HSO,'C^,^jj|.cJgJ^jjHjj|.jj«^^^^.gQ^H 

Prepared  by  treating  the  colour  from  tetrazo- 
tised  2  :  6-tolylenediamine-4-sulphonic  add  and 
2  mols.  of  m-phenylenediamine  with  2  mols.  of 
diazotised  naphthionio  add.  Brown  aqueous 
solution  g^vee  a  brown  predpitate  with  hydro- 
chloric acid.  Solution  in  sulphuric  acid  is  duU 
reddish-violet. 

LUerature.—E,  P.  11000  of  1889;  D.  R.  P. 
68667  ;  F.  P.  199668 ;  A.  P.  466116. 

Hessian  Brown  BBN  (L.) : 

r  H  ^N,C.H^0H),N,-C,H4S0,H 
Ci,Hik^N^.C^H,(0H),N,cIh4S0,H 
Prepared  by  tiie  action  of  tetrazotised  benzidine 
on  2  mols.  of  the  monoazo-dyestuff  from  diazo- 
tised  sulphanilio  add  and  resoroinol.  Aqueous 
solution  is  brown,  giving  a  brown  precipitate 
with  hydrochloric  add,  and  becoming  red  with 
sodium  hydroxide.  Solution  in  sulphuric  acid 
is  violet-black,  giving  a  brown  precipitate  on 
dilution. 

Dianll  Black  PR  (M.) : 

HBO  C   H  /C.ioH*(803H)(OH)N,0,H,(NH^, 

•  "  \c,pH4(B0,HX0H)N,0,H^NH,), 
Benzidinesulphonio  acid  is  tetrazotised  and  com- 
bined with  2  mols.  of  7-amino-a-naphthol-3- 
sulphonic  add  (7-add)  in  alkaline  solution,  and 
the  product  is  tetrazotised  and  combined  with 
2  mds.  of  m-phenylenediamine.  Black  aqueous 
solution  is  precipitated  with  hydrochloric  add 
or  sodium  hydroxide.  Solution  in  sulphuric 
acid  is  dark-blue,  giving  a  blaok  precipitate  on 
dilution. 

Literature.— E.   P.    13743   of   1896;    F.   P. 
267246 ;  A.  P.  678680. 

Anthracene  Add  Brown  B  (0.) : 

NO,C,HJCO,HKOH)N,CioH,N,\ 

NO,'C,H,(CO,HKOH)N,CioH,N,/ 

Nitroaminoealicyclic  acid  is  diazotised  and  com- 
bined with  a-naphthyUmine.  Two  mols.  of  this 
are  diazotised  and  combined  with  1  mol.  of  m- 
phenylenediamine.  Brown  aqueous  solution 
gives  a  violet  precipitate  with  hydrochloric  acid. 
Solution  in  sulphuric  add  is  greyish-violet, 
giving  a  brown- violet  predpitate  on  dilution. 


Literature.— E,  P.  2446  of  1896 ;  D.  R.  P. 
92666 :  F.  P.  263834.  J.  C.  C. 

AZO-  ACID  YELLOW,  -AUZABIN 
YELLOW,  -BLACK  BASE  0,  -BORDEAUX, 
-CHROMDIE,  -COCCINE,  -CiDCHIlfEAL, 
-OORALLmE,  EOSINE,  -FLAVINE,  -FUCH- 
SHIES,  -VIOLET  {v.  Azo-  ooloubing  mattsbs. 

AZODERMIM.    Acetylamidoazotoluene. 

AZOERYTHROI  v.  Abchil. 

AZOFLAVm  V.  Azo-  ooLOXTBiNa  mattebs. 

AZOGEN  RED  v.  Azo-  coloubiko  mattbbs. 

AZOGRENADINES      v.    Azo-    coloubino 

1CATTXB8. 

AZOmiDE  (Hffdruroic  add)  NaH  was  first 
isolated  in  1890  bv  Curtius  (Bet.  1890,  23,  3023), 
although  in  the  form  of  its  phenyl  dwivative 
(diazobenzeneimide)  G«HsN,  it  was  known  in 
1866,  having  been  then  prepared  by  P.  Grieas 
(Annalen,  1866,  137,  66,  77). 

Curtius  obtained  azoimide  b^  the  action  of 
sodium  nitrite  and  acetic  acid  on  benzoyl 
hydrazine,  the  nitroso-  derivative  first  formed 
passing  into  benzoyl  azoimide  by  loss  of  water 

C,H,C50NHNH,+H0N0= 
H,0-f-C,H,CON(NO)NH,->H,0+C,H,OON, 

The  benzoyl  azide  so  obtained  was  dissolved 
in  an  equal  weight  of  absolute  alcohol  and 
digested  on  the  water-bath  with  1  mol.  pro- 
portion of  sodium,  also  dissolved  in  absolute 
alcohol,  when  sodium  aside  was  formed,  and  this 
was  precipitated  from  the  solution  by  the  addition 
of  etner : 

C,H,CON,+2NaOH 

= H,0 +C,H,OOONa+NaN, 

The  following  methods  have  also  been  em- 
ployed for  the  preparation  of  azoimide  and  its 
salts. 

1.  Hippuryl  hydrazine  bv  the  action  of 
nitrous  acid  is  converted  into  hippurazide,  from 
which  by  the  action  of  ammoma,  ammonium 
azide  is  produced  (Curtius,  Ber.  1891,  24,  3341) : 

C,H,CONHCH,<JO  NHNH, 
HONG 

->    [C,H,CONHCH,<X)NHN,OH 

C,H,OONH-CH,-CON,-fH,0 

C,H,C0NHCH,C0NH,-|-NH4N,^  * 

2.  o.p-Diazobenzeneimide  (prepared  from 
o.p-Dinitro-aniline),  on  treatment  with  alcoholic 

Sotash,  yidds  potassium  azide  (Nfilting  and 
randmougin,  Ber.  1892,  26,  3328) : 

o.p.  C,H,(NO,),NH,-HNO, 

HOKO 
^     C,H,(NO,),N.NO, 
Br 
->    C,H,(NO,),NBrNBr, 


Jf    NH, 
C.Hrfl^O.),N. 


KOH 

C,H,(NO,)t-OK-fH,0+N,K    ^ 

3.  The  decomposition  of  diazotised  amido- 
guanidine  nitrate  by  caustic  alkalis  (Thiele. 
Annalen,  1892,  270,  1): 

HN :  C(NH,)NHNH,HNO, 

HOKO 
->    HN:C(NH,)NH-N,NO, 

-»       CNNH,+HNO,-fNtH 


AZOmiDE. 


497 


4.  The  action  of  nltrooa  oxide  on  sodamide 
(W.  WiBlicenuB,  Ber.  1802,  86,  2084) : 

NaNH.+N,0=NaNg+N,0 

6.  The  aotion  of  an  aqueona  solution  of 
hydrazine  on  a  benzene  solation  of  nitrogen 
chloride  (Tanatar,  Ber.  1899,  32,  1399) : 

N^4+NCla=NgH-f3Ha 

6.  The  oxidation  of  a  miztore  of  hydrazine 
sulphate  and  hydroxylamine*  hydrochloride  by 
ehromio  acid  mixture  (Brown,  Ber.  1905,  38, 
1826). 

7.  The  decomposition  of  hydrazine  sulphate 
by  potassium  nitrite  (Dennstedt,  Chem.  Zeit. 
1897,  21,  876) : 

N,H4+H0N0  -» [NHjN.OH] -^ HtO+N,H 

8.  The  decomposition  of  hydrazine  sulphate 
by  a  saturated  aqueous  solution  of  silver  nitrite, 
crystalline  silyer  azide  being  precipitated 
(^eli,  Ber.  1893,  26,  885,  Ref.). 

9.  In  nearly  quantitative  yield,  th^  sodium 
salt  may  be  prepared  by  mixing  hydrazine 
hjrdrate  witA  sodium  methoxide,  and  adding  an 
ether  solution  of  ethyl  nitrite  to  the  mixture. 
If  the  free  add  be  required  it  is  sufficient  to 
shake  hydrazine  sulphate  for  several  hours  with 
sodium  hydroxide  solution  and  ethyl  nitrite, 
about  8(^84  p.c.  of  the  hydrazine  compound 
undergoing  decomposition  (Thiele,  Ber.  1908,  41, 
2681). 

The  free  add  may  be  obtained  by  distilling 
the  salts  with  dilute  sulphuric  add.  In  the 
anhydrous  condition  it  is  a  colourless  mobile 
liqmd  of  very  unpleasant  odour.  It  boils  at 
37**  C,  and  is  readily  soluble  in  water.  Azoimide 
is  a  most  dangerous  substance  to  handle  on 
account  of  the  fact  that  it  decomposes  with 
explosive  violence  on  agitation.  It  somewhat 
resembles  the  halosen  acids  in  that  it  forms 
difficultly  soluble  lead,  silver  and  mercurous 
salts.  It  is  very  poisonous,  its  vapour  attacks 
the  mucous  membrane  rapidly,  whilst  the 
aqueous  solution  of  the  acid  attacks  the  skin. 
The  metallic  salte  of  the  add  all  crystallise  in 
the  anhydrous  state,  and  when  heated,  decom- 
pose, senerally  with  explosive  violence,  leaving 
a  residue  of  the  pure  metal. 

Azoimide  is  a  *  weak  *  acid,  comparable  in 
strength  with  acetic  acid  (West,  Trans.  1900, 
77,  705).  The  heat  of  formation  of  the  acid 
has  been  measured  by  Berthelot  and  Matignon 
(Compt.  rend.,  1891,  113,  672),  with  the  foUow- 
ing  result: 

3N-f  H4-aq=NaHaq-61,600  cal. 

A  7  p.o.  solution  of  the  acid  dissolves  magnesium 
and  zinc,  with  evolution  of  hydrogen.  From 
solutions  of  ferric,  aluminium,  chromic  and 
thallium  salte  the  corresponding  hydroxides  are 
quantitetively  precipiteted  on  boiling  with 
azoimide.  On  reduction  with  sodium  amalgam, 
or  by  zinc  and  add,  azoimide  is  converted  into 
ammonia  and  hydrazine;  if,  however,  sodium 
sulphide  or  ferrous  hydroxide  be  used  as  reducing 
agents,  little  hydrazine  is  formed. 

The  reaction  N,H+HNO,=N,-hN,0+H,0 
IB  quantitative,  and  can  be  used  for  the  estima- 
tion of  simple  nitrites.  In  this  method  a  known 
excess  of  sodium  azide  ia  added  to  the  acid 
solution  of  the  nitrite,  and  the  mixture  well 
shaken.  The  solution  is  made  just  alkaline  by 
Vol.  I.— T. 


baiyta  water,  boiled  to  expel  nitrous  oxide, 
acidified  by  acetic  add  and  tne  excess  azoimide 
estimated  by  titration  with  iodine  and  sodium 
thiosulphate. 

Hyarazine  azide  NgH, ;  is  obtained  by  the 
action  of  lead  azide  on  hydrazine  sulphate.  It 
crystallises  in  prisms  and  is  veiy  volatik.  When 
rapidly  heated  it  explodes  with  great  violence. 

loaine  azide  N,I  is  obtained  as  an  unsteble 
nearly  colourless  solid  when  silver  azide  is 
suspended  in  water  and  shaken  with  a  solution  of 
iodme  in  ether  at  0®  G.  (Hantzsch,  Ber.  1900,  33, 
522).  It  decomposes  readily,  alkaline  hydroxides 
converting  it  into  the  correspondmg  idkali 
azide  N,H-2KHO=N,K4-H,0+KJO.  The 
aqueous  solution  of  the  azide  n'adually  decom- 
poses on  keeping  N,I+H,0=N,H+H10. 

Chlorine  aziae  N,C1  was  prepared  in  1908  by 
Raschig  (Ber.  1908,  41,  4194),  on  addinc  sodium 
hypochlorite  to  sodium  azide  and  acidifying  the 
mixture.    It  is  a  colourless  gas. 

Phenyl  azide  (Diazobenzene  imide)  CgH^, 
was  first  prepared  by  Griess  (Annalen,  1866, 
137,  65,  77)  by  decomposing  diazobenzene  per- 
bromide  with  ammonia.  It  is  a  pale  yellow  oil 
boiling  at  65'5*'-66'5°  C,  and  is  volatile  in  steam. 
On  heatinff  with  hydrochloric  acid  it  yields 
o-  and  p-chloroaniline  and  nitrogen.  Reduction 
in  add  solution  converte  it  into  aniline  and 
ammonia. 

Benzyl  azide  CjH^l^^  is  obtained  as  an 
aromatic  smeUing  oil,  by  the  action  of  warm 
acid  on  nitrosobenzylhyarazine,  or  by  decom- 
posing silver  azide  with  benzyl  iodide.  It  boils 
at74^C.  (11  mm.). 

Azides  of  the  above  type  may  be  obteined 
generally  by  the  following  methods: — 

1.  The  decomposition  of  diazobenzene  per- 
bromides  with  aqueous  ammonia : 

C,H,NBrNBr,-f4NH,=C,H5N,-f3NH4Br 

2.  The  decomposition  of  diazonium  sulphates 
with  hydroxylamine : 

C,HjN,HS04+NH,OH=H,S04+HtO  +  C,HjN, 

3.  The  action  of  nitrous  acid  on  phenyl- 
hydrazine  hydrochloride : 

C.HjNHNH,    ->    C,H-N(NO)NH, 

->    H,0+C,H,N, 

4.  The  decomposition  of  ;9-phenylBemi- 
carbazides  with  sodium  hypochlorite : 

0,HjNHNH-CONH,    -^     C.H,N :  NCONHt 
->    C,HjN:NNH,    ->    C,H,N, 

6.  The  action  of  chloroamine  on  diazonium 
salte  (M.  0.  Forster) : 

C,H,Na+NH,a=Ha-fC,H4N :  NNHa 


^ 


-»    HC1+C,H,N, 

6.  Aryl  diazonium  derivatives  of  trinitro- 
methane  readily  decompose  in  the  presence  of 
moist  ether  to  aryluof  ormhydroxamio  adds,  and 
the  latter  on  heating  with  aqueous  alkali 
hydroxides  are  convert^  into  the  corresponding 
azide  (Ponzio,  Gazz.  1915,  45,  ii.  12  ;  1916,  46, 
ii.  56) : 

ArN.OON  :  C(NO,),    ->    ArN  :  NCONHOH 

ArN,+CO,+H, 

The  aryl  azides  are  decomposed  on  heating 

2  K 


i98 


AZOIMEDE. 


with  hydrochloric  acid,  nitrogen  being  evolved 
and  the  corresponding  chloro-anilinee  formed 
Similarly  with  sulphuric  acid  they  yield  amino- 
phenols.  Hot  alcoholic  potash  converts  the 
o-  and  p-nitro  derivatives  mto  azoimide  and  the 
nitrophenols.  On  condensation  with  the 
Grignard  reagent  and  subsequent  decomposition 
diazoamines  (triazens)  are  formed  (Dimroth) : 

C,H,N,-f  CHjMgl      ->      C.HjN  :  NN  CH, 

Mgl 
->    C,H,N : NNHCH, 
Phenyl  methyl  tilizen 

Condensation  with  j3-ketonic  esters  converts 
them  into  triazoles  (Ber.  1902,  35,  4041) : 

C^H^N.+CHjCOOR 

=     H,0+ 
30  CH, 


I. 


i/ 


N- 


CCOOR 

\N(C,H,)-C;CH, 

whilst  with  benzaldehyde-arylhydrazones   they 
similarly  yield  tetrazoles  (Ber.  1907,  40,  2402) : 
C.HjNg-f  C,H,NHN :  CHC.H, 

c=C,H5NH,+CeH,N(^         I 

\N=CC,H, 

Mdhyl  azide  CH,*N,  is  prepared  bv  the  action 
of  dimethyl  sulphate  on  sodium  azide  (Dimroth 
and  W.  Wislioenus,  Ber.  1905,  38,  1573).  Mag- 
nesium methyl  iodide  converts  it  into  dimethyi- 
triazen  CH,N :  NNHCH,  (Dimroth,  Ber.  1906, 
39, 3905). 

The  acyl  derivatives  of  azoimide  may  be  pre- 
pared by  the  decomposition  of  acyl  hydrazmes 
with  nitrous  acid  (so<Hum  nitrite  and  acetic  acid) : 
0,HjCONHNH,-fHONO=C.H5CON,-f2H,O 

Tetrameihylammonium  azide  NMe^Ng  is 
prepared  by  the  gradual  addition  of  a  solution  of 
tetramethylammonium  iodide  to  an  aqueous 
suspension  of  a  slight  excess  of  silver  azide. 
Tetragonal  oiystals  (a  :c=l :  0*7245).  Fairlv 
stable  substance  ;  does  not  explode  when  struck 
with  a  hammer,  or  ground  in  a  mortar,  or  when 
dropped  on  a  hot  plate.  Dry  salt  b^ins  to 
decompose  at  about  125°  (Friedlander,  J.  Amer. 
Ghem.  6oc.  1918,  40,  1945). 

Benzeyl  azoimide  CcH^CON,  (Curtius,  Ber. 
1890,  23,  3024  et  seq.)  crystalUses  in  colourless 
tables  and  melts  at  32**  0.  It  explodes  on 
heating. 

This    type    of    azide    shows    characteristic 
decompositions,  two-thirds  of  the  nitrogen  being 
eliminated,  and  the  residual  nitrogen  linking 
up  the  aromatic  nucleus  with  a  carbonyl  group. 
Thus  when  gently  warmed  in  alcoholic  solution 
a  urethane  is  produced,  on  boiling  with  water  a 
di-substituted  urea  is  obtained,  and  on  heating 
the  solution  of  the  azide  in  benzene  it  is  trans- 
formed into  an  iBOoyanate : 
C,H,C50N,-fO,H,OH=N,-fC,H,NHCOOC,H, 
2C,H500N,-f2H,0=2N,-f2C,HjNHCOOH 
=2N^H,0+CO,+CO(NHC.H5), 
C,H,C0N,=N,+C,H5NC0 

On  tne  decomposition  of  the  azides  of  the 
mono  and  dialkyf  malonic  acids,  and  of  the 
a-hydroxy  acids,  see  Festschrift  Th.  Curtius, 
1907,  p.  Ixxxii 

Some  controversy  has  arisen  over  the  struc- 
ture of  azoimide,  the  earlier  given  cyclic  struc- 


ture having  been  objected  to  by  Thiele  (Ber. 
1911,  44,  2522)  who  considers  that  a  straight 
chain  formation  best  represents  the  reactions  of 
the  acid : 

^\ 

II  \NH  or  HN  :  N  :  N 

N/ 
AZOIMIDES,    AROMATIC   v.    Diazo   com- 

POUNDS. 

AZOLTTMIN.    A    substance    assumed     by 
Kane  to  exist  in  litmus  (Annalen,  39,  25). 
AZOMETHANE  v.  Dtazo  compouxds. 
AZOORSEILUN       v.      Azo-       coLOUBiNa 

MATTERS 

AZOPHENTLENE  v.  Azines. 

AZOPHOR  -BLACK,  -BLUE,  -RED,  -ROSE  v. 

Azo-  colourino  matters. 

AZOPHOSPHINES      v,     Azo-    coloubiho 

MATTERS 

AZO-REDS,  AZORUBOfES  v.  Azo-  coloub- 

ING  MA^iTBRS. 

AZOTE.  A  name  given  to  nitrogen  bv 
Lavoisier,  and  hence  commonly  used  in  French 
literature  to  d^icnate  that  element. 

AZOTINE.  An  explosive  made  in  Austria- 
Hungary  (J.  Soc.  (]!hem.  Ind.  4,  366). 

AZOTOL  V.  Azo-  coLOURmo  matters. 

AZOTOMETER.  A  term  applied  by  W.  Knop 
to  an  apparatus  designed  to  measure  the  nitrogen 
evolved  Dy  the  action  of  sodium  hypochlorite  or 
hypobromite  on  ammonium  salts  and  certain 
organic  substances. 

AZO-    TURKEY    RED  v,  Azo-  coLOURrNQ 

MATTERS. 

AZOVERMIN.  Trade  name  for  acetyl- 
amino  azotoluene. 

AZOXINE     COLOURING      MATTERS     «. 

OXAZINE  COLOITRIMO  MATTERS. 

AZOXYBENZENE  C,.H.oN,0.  A  product 
of  the  partial  reduction  of  nitrobenzene  with 
alcoholic  potash  (Zinin,  J.  pr.  Chem.  36,  93; 
Schmidt  and  Schultz,  Annalen,  207,  325 ;  Ber. 
12,484);  or  with  sodium  amalgam  containing 
3-8  p.c.  of  sodium  (Alexejeff,  J.  1864,  625; 
Moltschanowsky,  Ber.  15,  1575). 

Preparation. — Azoxybenzene  is  best  prepared 
by  dissolving  1  part  of  sodium  in  25  parts  of 
methyl  alcohol,  adding  3  parts  of  nitrooaizene 
and  heating  for  5  or  6  hours  on  a  water-bath  in 
a  flask  provided  with  a  reversed  condenser.  The 
methyl  alcohol  is  then  distilled  off  and  the  residue 
treated  with  water,  which  dissolves  the  aodium 
formate  formed  in  the  reaction,  and  leaves  the 
azoxybenzene  as  a  yellow  oil;  this  soon  solidi- 
fies, and  is  obtained  pure  by  one  cryflAdlisation 
from  alcohol  (Klinger,  Ber.  15,  866;  Molt- 
schanowsky, he,  and  Ber.  16,  81 ;  Klingw, 
Ber.  16,  941,  footnote). 

Azoxybenzene  is  ako  prepared  by  the 
redaction  of  nitrobenzene  with  araenioQB  oxide 
and  canstio  soda  (Loesner,  Eng.  Pat.  1566, 
J.  Soo.  Chem.  Ind.  1895,  31) ;  by  the  rednction 
of  nitrobenzene  with  alkali  sulphides  in  alkali 
hydroxide,  the  products  being  mainly  azoxy- 
benzene and  azobenzene,  in  proportions  varying 
with  the  amount  of  sulphide  and  the  time  3 
reduction  (Farb.  vorm.  Meister,  Lncins,  and 
Bruning,  D.  R.  P.  216246,  J.  Soc  CShem.  Ind. 
1909,  1310);  by  boiling  nitrobenzene  with 
60  p.0.  aqueous  sodium  hydroxide  and  iron 
pyrites,  or  other  heavy  sulphides,  90  p.c  of  the 


BABLAH  OR  NEB-NER 


400 


product  botng  uoxybenzene  (Farbenfab.  yonn. 
Fried.  Bayer  A  Co.,  D.  H.  P.  204653,  Chem.  800. 
Abet.  IW9^  L  272) ;  by  heatiDff  nitrobenzene 
witb  cbarcoal  and  alkali  (Farbenfab.  Torm. 
Fried.  Bayer  &  Co.,  D.  R.  P.  210806 ;  Cbem. 
Zentr.  1000.  IL  163) ;  and  by  tbe  electrolytic 
reduction  df  nitrobenzene  in  tbe  presence  of 
alkali  (Farb.  vorm.  Meistor,  Lucius,  and  Bruning, 
D.  R.  P.  127727 ;  Chem.  Zcntr.  1002,  i  440, 
and  Farb.  vorm*  Weiler-ter-Meer,  D.  R.  P. 
138406 :  Chem.  Zentr.  1003,  L  372). 

Azoxybenzene  or  its  homologues  can  be 
obtained  b^  heating  nitrobenzene  or  the  oorro- 
sponding  nitro-  compound  with  an  equal  weight 
of  zinc- dust  and  of  an  aqueous  solution  of  eal- 
oium  chloride  boiling  at  130^ ;  aqueous  solutions 
of  other  salts  may  be  employed,  and  the  reactiuu 
ensues  at  the  boiling-point  of  the  aqueous  soiu 
tion  {V,  Dechend,  J),  R.  P.  43230). 

Pro;wHiM.^-Azoxybenzene  crystallises  in 
pale  ydlow  rhombic  needles,  melts  at  36^,  and 
18  soluble  in  alcohol  or  ether,  insoluble  in  water. 
When  heated  with  non-volatile  substances,  such 
as  iron  filings,  it  decomposes  into  aniline  snd 
azobenzene.  Weak  reducing  agents,  such  as 
sodium  amalgam  in  alcoholic  solution,  convert  it 
into  hydrazooenzene  (AlezejefF,  J.  1867,  603) ; 
but  more  powerful  Ments,  such  as  zinc  chloride 
in  acid  solution,  reduce  it  chiefly  to  aniline,  a 
small  quantity  of  hydrazobenzene  and  bases 
derived  from  it  by  molecular  changes  being 
also  formed  (Schmidt  and  Schultz).  Azoxy- 
benzene yields  two  isomeric  nitroazoxybenzenes 
when  heated  with  concentrated  mtric  acid 
(Linin,  Annalen,  114, 217),  and  when  heated  with 
concentrated  sulphuric  acid  to  a  moderate 
temperature  is  converted  into  the  isomeric 
hydroxyazobenzene  (WsUach  and  Kiepenheuer, 
Ber.  14,  2617). 

In  addition  to  azoxybenzene  other  azoxv- 
compounds  have  been  prepared  by  reducing  the 
corresponding  nitro-  derivatives  either  with 
sodium  amalgam  in  methyl  alcohol  solution  or 
with  zinc-dust  and  soda  (c/.  Limpricht,  Ber.  18, 
1406;  Klinger  and  Pitechke,  Ber.  18,  2553; 
Janovdcy  and  Reimann,  Ber.  22, 41 ;  v.  Dechend, 
Le.),  Tne  s^oxy-  compounds  derived  from 
metanitraniline,  the  nitrotoluidines  melting  at 
78^  and  107°,  and  the  nitroxylidine  melting  at 
123*^  yield,  when  diazotised  and  combined  witb 
phenols,  amines  or  their  sulphonic  acids,  a  class 
of  yellow,  orange  or  red  azo-  dyes,  which  can  be 
employed  for  cotton  and  wool  (Poirrier  and 
Rosenstiehl,  D.  R.  P.  44045, 44554). 

AZOXY- COLOURING  MATTERS.    The  dyes 
formerly  classified  under  this  heading,  of  which 
*  sun  yellow '  is  perhaps  the  best  known,  have 
been  shown  to  be  azo-  dyes  (9. v.). 
p-AZOXTo-TOLUIDlifE 


iB  obtained  by  the  alkaline  reduction  of  p-nliro- 
o-toluidine  {q,v.)  by  zinc  dust  or  dextrose; 
m.p.  168^  Used  in  the  manufacture  of  azo- 
dyes. 

AZO- YELLOWS  v.  Azo-ooloubiko  matters. 
AZULENE  C|.Ht«,  a  hydrocarbon,  an 
intensely  blue,  slighUy  viscid  liquid,  D,.00738. 
b.p.  205*'-300**  ( 185**-105°/25  mm.),  found  in  the 
oils  of  cubebs,  amyris,  guaiaoum  wood,  gurjun 
and  eucalyptus,  and  to  which  their  blue  colour 
is  due.  When  exposed  to  ligh^  and  air  is  con- 
verted into  a  brown  resin.  Is  soluble  in  sul- 
phuric acid,  giving  a  fluorescent  solution,  and 
forming  a  sulphonic  acid,  yielding  a  crystalline 
sodium  salt,  soluble  in  water,  and  giving  a  violet- 
coloured  solution  which  becomes  green  when 
acidified.  Is  possibly  identical  with  Piease's 
Azulin  iq.v.).  It  forms  a  pierate,  m.p.  120^, 
lustrous  bUck  needles,  by  which  the  hydro- 
carbon may  be  identified.  It  appears  that 
azulene  is  tricyclic  and  contains  an  aromatid 
nucleus,  four  ethylenic  Unkings,  but  no  hydro- 
aromatic  conjugate  double  linkii^s,  as  it 
suffers  no  reduction  when  treated  with  sodium 
in  alcohol  (Shemdal,  J.  Amer.  Chem.  Soo. 
1015,  37,  167  and  1537). 

AZULIN.  Blue  colouring  matter,  contained 
in  certain  essential  oils ;  e,g,  chamomile,  mille- 
folium, and  wormwood. 

AZULIN  V.  Triphenylmsthanx  coloubino 

MATTSRS. 

AZURE  v.  Pigment. 

AZURIN  C,.H.,N40,.  Obtained  by  heaUng 
salicylic  aldehyde  with  o-tolylenediamine. 
Colourless  tables,  givins  blue  fluorescent  solu- 
tions (Ladenbux^,  Ber.  11,  506). 

AZURITE  or  Chessylite.  Hydrated  basic 
copper  carbonate,  2CuC0,*Cu(0H)„  forming 
monodinio  crystals  of  an  azure- blue  colour. 
Finely  crystallised  specimens  have  been  found 
in  abundance  in  an  old  copper  mine  at  Chessy, 
near  Lyon  in  the  south  of  France,  and  on  this 
account  the  mineral  is  often  known  as  chessylite 
(Brooke  and  Miller,  1852);  the  name  azurite 
(F.  8.  Beudant,  1824)  refers  to  the  characteristic 
colour.  Sp.gr.  3-8 ;  hardness  3|-4.  It  ocour.^ 
as  an  alteration  product  of  copper-pyrites  and 
other  sulphide  ores  of  copper  in  the  'upper 
oxidised  zones  of  mineral  veins ;  and  it  is  itself 
often  altered  to  malachite,  the  green  carbonate 
(CuCOa'Cu(OH)t).  Fine  crystals  are  also  found 
at  Broken  Hill  in  New  South  Wales,  Tsumeb  in 
South- West  Africa,  and  at  Bisbeo  in  Arizona ; 
at  the  last-named  place  it  occurs,  together  with 
malachite,  in  sufficient  abundance  to  be  mined 
as  an  ore  of  copper.  It  was  also  formerly  mined 
at  Burra-Burra,  in  South  Australia.  From 
Arizona  come  pretty  specimens,  with  azurite  and 
malachite  banded  together,  which  are  polished 
for  use  in  cheap  jewellery.  Powdered  azurite 
was  foimerly  used  as  a  i)igment  under  the  name 
*  mountain  blue,*  but  this  is  now  replaced  by  an 
artificial  product.  L.  J.  S. 


B 

BABBIT*8  METAL,    An  alloy  of  25  parts  I  East,  in  combination  with  alumina  and  iron 
Hn,  2  parts  antimony,  and  0*5  part  copper,  used  '  mordants,  to  produce  various  shades  of  drab  and 


as  an  anti -attrition  metal  (v.  Antimony). 

BABLAH  or  NEB-NEB.    Commercial  names 
for  froits  of  several  species  of  acaoia ;  used  in  the 


fawn  colour  ~in  calico-printing.  East  Indion 
bsblah  is  largely  obtained  from  Atacia  arabiea 
(Willd.)    {A.  indiea    (Benth.)) :    Senegal    snd 


600 


BABLAH  OR  NEB.KEB. 


Effypiian  Bablah  largely  from  Acacia  arabica 
{A,  nikiiea  (DeliL)).  The  aqueous  extracts 
contain  a  red  colouring  matter  together  with 
considerable  quantities  of  gallic  and  tannic  acids. 

BABUL  BARK.  The  bark  from  Acacia 
arabica  (Willd.)  which  occurs  in  India,  Arabia, 
and  tropical  Africa :  its  Indian  vernacular  name 
is  *  babul.'    Used  in  India  as  a  tannine  material. 

BABUL  GUM.  An  inferior  kind  of  gum 
arable  from  Acacia  arabica  (Willd. ).  Known  also 
as  *  Bengal  gum '  or  *  Gond  babul.' 

BACTEIUA,   CHEMICAL   ACTION   OF,   v. 

FflBlffENTATION. 

BADDELEYITE.  Native  zirconium  oxide, 
ZrO(,  crystallising  in  the  monoclinic  system. 
A  few  isolated  ciystals  have  been  found  in  the 
gem-ffravels  of  deylon,  and  a  more  abundant 
supp^  of  small  crystals  was  met  with  at  about 
the  same  time  in  the  iron  mine  of  Jacupiranga, 
in  Sfto  Paulo,  Brazil.  The  latter,  at  first  de- 
scribed under  the  name  brazilite,  occur  as  an 
accessory  constituent  of  a  magnetite-pyroxene 
rock  called  jacupirangite,  which  is  associated 
with  the  deposits  of  magnetite.  The  crystals 
from  Ceylon  are  black  and  opaque,  with  sub- 
metallic  lustre,  but  small  splinters  are  trans- 
parent and  ycdlowish  in  colour;  sp.gr.  6'72> 
6-025 ;  ZrO,  98*9  p.c.  The  smaller  crystals 
from  Brazil  range  from  colourless  to  brown; 
sp.gr.  5*5 ;  they  contain  ZrO^  96*52  p.c,  with 
small  amounts  of  silica,  alumina,  ferric  oxide, 
lime,  &c.  The  mineral  has  also  been  identified 
in  a  rock  resembline  jacupirangite  in  the  iron 
mines  of  the  island  of  Alno,  Sweden.  More 
recently,  minute  crystals  have  been  detected 
in  a  sanidine  bomb  rich  in  zircon  from  Monte 
8omma,  Vesuvius,  and  in  a  corundum-syenite 
from  Bozeman,  Montana. 

A  massive  form  of  zirconia  occurs  much  more 
abundantly  in  the  Serra  de  Caldas  region  of 
Minas  Qeraes,  Brazil,  a  r^on  characterised 
by  the  occurrence  of  nepheune-syenite  rocks. 
Peb^es  of  compact  material  are  here  found  in 
the  diamond  washings,  and  are  known  to  the 
diamond  miners  as  *  favas  '  (meaning  *  b^an  ; ' 
other  *  favas'  consist  of  titanium  dioxide). 
These  are  pale-brown,  slate-grey  or  blackish  in 
colour,  fine-grained,  and  hara.  Sp.gr.  4*6-5*4 ; 
they  contain  ZrO,  73-93  p.c,  the  principal 
impurity  being  silica,  with  some  iron,  alumina, 
and  tituiium.  In  the  same  region  there  has  also 
been  found,  as  a  crust  on  weathered  augite- 
syenite,  mamillated  or  reniform  masses  with  a 
radially-fibrous  structure  and  concentric  band- 
ing. It  contains  ZrO,  97  p.c,  and  has  sp.gr. 
5*538.  This  variety  appears  to  occur  in  con- 
siderable quantity,  and  m  lumps  weighing  several 
kilograms.  E.  Hussak,  in  1899,  referred  the 
massive  form  occurring  as  '  favas '  to  badde- 
leyite,  but  he  was  inclined  in  1903  to  regard  the 
fibrous  variety  as  a  distinct  modification  of 
zirconia.  The  latter  has  recently  been  sold  in 
America  under  the  trade  name  ztrkite,  and  it  is 
stated  to  consist  of  a  mechanical  mixture  of 
baddeleyite,  zircon,  and  a  new  zirconium  silicate. 
The  mineral  possesses  a  high  desreeof  infusibility, 
high  resistance  to  basic  ana  acid  slags,  low 
thermal  conductivity,  and  a  very  low  coefficient 
of  expansion.  It  is  thus  eminently  suitable  as 
a  renuctoiy  material  for  the  construction  of 
crucibles,  muffles,  fire-bricks,  and  furnace 
linings.    It   is  also  employed  as  an  opacifier 


and  as  an  abrasive.  (W.  T.  SohAUer,  Mineral 
Resources,  U.S.  Geol.  Survey  for  1916,  1917,  ii 
877;  A.  Granger,  Ghem.  News,  1919,  118, 115.) 

L.  J.  S. 
BADISCHE    ACID.    2-naphthylam]ne-8-  sul- 
phonic  acid.     F.  Naphthai^enb. 

BAEL  FRUIT.  The  dried  half-ripe  fruit  of 
ASgle  Marmelos  (Correa),  from  Malabar  and 
Coromandel ;  is  used  in  diarrhoea  and  dysentery, 
and  the  fresh  pulp  is  sometimes  employed  as  a 
laxative.  

BAEUMLERTTE.  A  potash-salt  mineral 
found  as  thin  bands  in  the  rock-salt  of  the 
Desdemona  salt  mine  in  the  Leine  Valley, 
Prussia  (0.  Benner,  1912).  It  is  colourless  and 
transparent,  extremely  deliquescent,  and  has 
the  composition  KCl'CaCl,.  F.  Zanibonini 
(1912)  has  suggested  that  this  is  identical  with 
the  Vesuvian  mineral  *  chlorocalcite,'  first 
described  by  A.  Scacchi  in  1872,  and  later 
proved  to  lie  cubic  and  with  the  composition 
Ka-Caa,.  L.  J.  S. 

BAGASSE,  BEGASS,  or  ME6ASS.  Terms 
applied  to  the  refuse  sugar-cane  after  crushing. 

BAKELITE.  A  condensation  product  of 
phenol,  cresol  or  other  phenolic  bodies,  and 
formaldehyde,  paraformaldehyde,  hexamethy- 
lenetetramine,  or  other  substances  with  a  reactive 
methylene  group,  mixed  with  asbestos  or  some 
form  of  cellulose,  and  heated  so  as  to  convert  it 
into  a  solid  infusible  resinoid  teass  capable  of 
being  moulded  or  worked. 

In  the  actual  manufacture  of  bakelite 
ordinary  commercial  carbolic  acid,  which  con> 
sists'lai^ely  of  cresols,  is  employed,  in  connection 
with  small  quantities  of  various  alkaline  sub- 
stances, which  appear  to  act  catalytically  in 
promoting  the  action  of  the  formaldehyde. 
The  first  products  obtained  are  semi -solid  resin- 
like bodies  which  under  the  influence  of  heat  and 
pressure  become  hard,  insoluble  and  infusible, 
and  of  a  high  chemical  and  mechanical  resistance. 
This  initial  stage  is  variously  termed '  Bakelite  A, 
Liquid  or  Solid,'  Resinil  mass,  &c.  The  final 
product  is  known  as  'Bakelite  C,'  'Resinite,' 
^^Condensite,'  or  '  Resite.*  It  is  r^arded  by 
Backeland,  with  whose  name  the  invention  and 
commercial  application  of  the  substance  is 
associated,  as  a  polymerised  hydroxybenzyl- 
methvleneglycolanhydride.  To  form  it  'Bake- 
lite A '  is  heated  in  a  modified  form  of  auto- 
clave to  about  170°,  under  pressure  produced 
by  compressed  air  or  an  inert  gas,  such  as 
carbon  dioxide.  Instead  of  the  autoclave  the 
Bakelite  A,  after  being  mixed  with  the  appro- 
priate fibrous  material,  may  be  placed  in  a  steel 
mould,  and  gradually  hardened  in  a  hot  press 
during  from  1  to  2  hours,  at  a  temperature 
between  100°  and  200°. 

Bakelite  C  in  its  purest  form  is  a  colourless 
or  light  golden-yellow  mass  of  sp.gr.  1*25. 
It  is  a  bad  conductor  of  heat  and  deciricity, 
and  a  first  rate  insulating  material.    It  resists 

{)res8u!re  and  shock,  but  has  a  comparatively 
ow  elasticity.  It  can  be  heated  to  300°  without 
change.  At  a  higher  temperature  it  chars,  but 
does  not  inflame.  It  is  non-hj^grosoopio,  and 
resists  the  action  of  concentrated  hydrochlorio 
acid,  oil  of  vitriol,  nitric  acid  and  bromine. 
It  is  less  resistant  to  the  action  of  alkalis.  From 
the  ease  with  which  it  can  be  worked  it  can  be 
used  for  a  great  variety  of  articles,  such  as 


BAKING   POWDERS. 


601 


Bwitch-boards,  telephone  receivers,  armAtores, 
and  commut-ators  for  dynamos  and  motors, 
phonograph  records,  mouldings  for  kodaks, 
photographic  developing  trays,  &c.  Also  for 
the  manufacture  of  billiard-balliB,  razor  handles, 
umbrella  and  stick  handles,  pen  and  pencil 
holders,  cigar  and  cigarette  holders,  pipe  mouth- 
pieces, ornaments  and  beads  for  jewelleiy,  &o. 
(Lebach,  Jour.  Soc.  Ghem.  Ind.  1913,  32,  559). 
The  conditions  of  the  formation  of  bakelite 
have  been  investigated  by  Matsumoto  (J.  Chem. 
Ind.  (Tokyo)  18,  No.  207),  who  found  that  all 
stages  of  the  reactions  are  greatly  accelerated  by 
small  additions  of  various  substances.  The 
best  results,  as  regards  yield  and  quality  of 

Eroduct,  were  obtamed  by  the  use  of  sodium 
ydroxide  and  ammonia  as  condensing  and 
hardening  agent  respectively.  Sulphuric  acid, 
hydrochloric  acid,  ammonia,  hexamethylene- 
tetramine,  aniline,  sodium  sulphite  and  sodium 
carbonate  were  also  satisfactory  as  condensing 
acents,  but  only  basic  substances,  such  as 
aScali  hydroxides  or  ammonia  were  suitable  as 
hardening  agents  (Jour.  Chem.  Soc.  Ind.  1915, 
34, 1104). 

The  General  Bakelite  Co.  has  a  very  complete 
plant  at  Perth,  Amboy,  and  there  are  a  large 
number  of  licensees  in  the  United  States ; 
bakelite  plants  in  Germany,  France  and  England, 
and  several  factories  where  bakelite  ^oods,  such 
as  buttons,  are  manufactured  under  licence. 

Bakelite  is  amber-yellow  when  freshly  made, 
but  graduallv  aoauires  a  wine-red  colour  under 
the  action  of  daylight.  If  the  red  colour  is  not 
too  strong  it  may  oe  discharged  by  heating  to 
100^-150°  for  several  hours.  This  colour  change 
has  proved  objectionable  when  the  substance  is 
naea  for  ornamental  purposes  (imitation  amber), 
and  has  led  to  its  abfuidonment  in  certain  trades 
(Newbery  and  Lupton,  Manchester  Memoirs, 
62  (1918),  13). 

BAKERTTE.  A  hydrated  borosilicate  of 
calcium,  8CaO'5B,0,-6SiOs -611,0,  containing 
B|0,  27*7  p.c.  It  is  massive  and  snow-white, 
sometimes  with  a  greenish  tinge,  and  resembles 
ungUued  procelain  or  fine-grained  marble  in 
appearance.  D  2-73-2*93,  H  4  J.  It  occurs  with 
howlite  as  veins  and  nodules  of  considerable  size 
in  the  borate  mines  in  the  Mohave  Desert,  sixteen 
miles  north-east  of  Daggett,  in  San  Bernardino 
Co.,  California  (W.  B.  Giles,  Mineralog.  Mag. 
1903,  xiii,  353).  L.  J.  S. 

BAKH A  R.  an  artificial  ferment  prepared  from 
rice,  powdered  roots  and  other  parts  of  certain 

Slants,  by  Indian  natives,  and  used  in  the  pro- 
uction  of  Hindu  rice-beer  (pachwai),and  of^the 
spirit  distilled  from  it.  It  contains  many  varie- 
ties of  moiflds  and  fungi  capable  of  saccharifying 
starch,  of  which  the  most  active  is  Aspergillus 
oryzcB,  and  several  yeasts  capable  of  producing 
alcohol  (Hutchinson  and  Ram  Ayyar  (Jour.  Soc. 
Chem.  Ind.  1916,  35,  761). 

BAKING  POWDERS  are  any  powders  used 
as  substitutes  for  yeast.  The  bread  or  cake 
is  rendered  spongy  by  the  carbon  dioxide 
generated  in  the  dough ;  this  is  effected  by  the 
action  of  an  acid,  such  as  tartaric  acid,  on  sdoium 
bicarbonate,  and  some  farinaceous  substance  is 
added  to  act  als  diluent.  To  permit  the  use  of 
djaooloived  flour,  alum  was  frequently  employed, 
this  reDders  the  bread  white,  but  at  the  same 
time  indigestible.    In   1399  such   artiolet   as 


baking  powder  were  included  in  the  Sale  of 
Food  and  Dru^s  Acts,  and  therefore  the  use 
of  alum  or  any  mjurious  matter  was  prohibited. 
All  articles  are  perfectly  dried  before  mixing, 
passed  through  a  fine  sieve,  and  kept  in  air- 
tight packages  in  a  dry  place.  To  ever^  pound 
of  flour,  1  teaspoonf  ul  of  baking  powder  is  added 
for  bread,  and  2  teaspoonf uh  for  cakes.  General 
preparations  are  i 

(1)  0  ozs.  tartaric  acid,  2  obb.  todium  bi- 
carbonate, and  1  -6  ozs.  of  farina. 

(2)  16  CIS.  sodium  bicarbonate,  14  oss. 
tartitfic  acid, -and  6  ozs.  magnesium  oarbonate, 
and  12  ozs.  farina  (Workshop  Receipts,  1909). 

(3)  2^  lbs.  cream  of  tartar,  21  lbs.  sodium 
bicarbonate,  1  lb.  acid  calcium  phosphate,  and 
4  Ibii.  ux)mflour  (Pharm.  Formula,  1008,  p.  822). 

{4)  3  lbs.  acid  potassium  sulphate,  .1  lb. 
sodfium  bicarbonate,  and  1  lb.  of  cornflour 
(Pharm.  Formula,  1908,  p.  322). 

(6)  6  ozs.  tartaric  acid,  16  ois.  cream  of 
tartar,  20  ozs.  sodium  carbonate,  and  M  ois. 
rice  flour  (Workshop  Receipts,  1909,  p.  90). 

(6)  20  parts  acid  sodium  phosphate,  20  parts 
acid  calcium  phosphate,  26  parts  sodium 
bicarbonate,  and  36  parts  starch  (Hiscox,  1907, 
102). 

Cratnpion^s  powder :  2  parts  cream  of  tartar, 
1  part  sodium  bicarbonate,  and  1  part  com 
starch. 

BumJord*t  powder  :  (approx.)  7  ozs.  sodium 
bicarbonate,  14^  ozs.  soaium  phosphate,  and 
3}  ozs.  starch. 

RoycU  powder:  A  mixture  of  cream  of 
tartar,  tartaric  acid,  sodium  bioslrbonate,  and 
starch. 

QoodaWe  powder  is  a  mixture  of  2  parts  rice 
flour  with  1  part  tartaric  acid  ana  1  part 
bicarbonate  of  soda. 

Oreen^e  powder :  36  lbs.  tartaric  acid,  66  lbs. 
of  sodium  carbonate,  and  1  cwt.  of  potato  flour. 

Horejord^e  powder  consists  of  2  packets:  (1) 
acid  calcium  and  magnesium  phospnates,  made 
up  with  a  certain  quantity  of  flour ;  (2)  bicarbo- 
nate of  soda  with  a  little  potassium  chloride. 

Bortoick's  powder  is  an  artificial  fermentation 
powder  compounded  with  coarse  maize. 

Sd/'raising  flour  may  be  prepared  by  mizing 
8  ozs.  sodium  bicarbonate,  and  18  ozs.  cream  of 
tartar  with  1  Qwt.  of  flour. 

Milk  in  the  solid  form,  concentrated  in  a 
vacuum  at  60*-60*  was  used  by  Hooker,  to 
replace  inert  farinaceous  matter.  It  is  claimed 
to  have  a  better  nutriment  value  and  increased 
leavening  power:  20  parts  tartaric  acid, 
54  parts  milk  powder,  and  1  part  moisture. 
The  soda  is  added  before  the  milk  is  completely 
dry,  then  the  whole  dried  and  ground  flnely  in 
a  mortar  (J.  Soc.  CSiem.  Ind.  27,  1908).  Cream 
of  tartar  is  soluble  in  hot  water,  but  only  slightly 
so  in  cold,  whilst  tartaric  acid  dissolves  refdily. 
Therefore  a  powder  containing  orean^  of  tartar 
evolves  carbon  dioxide  much  more  slowly  than 
one  compounded  with  tartaric  acid.  This  is 
advantageous,  as  a  dough  containing  it  can  be 
kept  for  some  time  before  baking,  also  it  does  not 
darken  the  bread  ;  on  the  other  hand,  it  forms 
Rochelle  salt  which  has  a  very  slight  saline 
taste.  The  best  powders  are  made  from  a 
mixture  of  tartaric  acid  and  cream  of  tartar. 
Gk)od  substitutes  for  tartaric  add  are  acid 
ammQuium    phosphate,    and    acid    potassium 


602 


BAKING  POWDERS. 


sulphate,  acid  potasskam  and  calcium  phosphates, 
but  they  have  a  tendency  to  darken  the  bread. 
The  acid  calcium  phosphate  used  in  baking  and 
self-raising  flours  occasionally  contains  an  undue 
amount  of  calcium  sulphate  (J.  M.  HamiU, 
Report  of  the  Local  Gov.  Board,  1911,  Food 
Report,  No.  13). 

Ammonium  carbonate  is  used  in  very  light 
pastries,  but  it  requires  expert  handling,  and 
so  is  very  rarely  present  in  the  make-up  pre- 
parations. 

BAKUIN.  Russian  mineral  machine  oils; 
rcoommended  for  lubricaling  heavy  machinery 
on  account  of  their  hiffh  viscosity  and  gieat 
power  of  lesisthig  cola  (Seifenseid,  Zeit.  31, 
36G;  32,  378;  J.  See  Chem.  Ind.  3,  181). 

BAKUOL.  A  name  given  by  Mendel^ff  to 
an  illuminating  oil,  prepared  m>m  the  crude 
oils  of  Baku  by  mizinff  ordinary  kerosene  of 
sp.^.  0-82  to  0-83  and  flashmi;  point  20*  to 
30^,  with  the  so-called  intermediate  oil,  which 
has  a  sp.sr.  of  0-86  to  0-88  at  16^  and  is  not  in- 
flammable at  100^  The  mixture  has  a  sp.gr.  of 
0-84  to  0-86,  and  fliashes  at  temperatures  varying 
from  00*  to  70*.  From  100  parts  crude  naphtha 
20  to  30  purts  of  kerosene  and  10  to  20  parts  of 
intermediate  oil  can  be  obtained. 

The  following;  taUe  gives  the  sp.gr.,  flashinff- 
point,  and  luminiferous  value  of  four  bakuds 
examined  by  Ilimow : — 


Speci- 

meaof 

oO 


No. 
1 
2 
8 

4 


Bp.gr. 

at 
17-«6 


0-8280 
0-8S10 
0*8880 
0-8810 


Flashing 
point  st 
700  mm. 


sSo 

87-6 
80-6 
49*6 


Csndle- 
power 


7-40 

10-40 

0-84 

8-80 


CJonsumptloa  per 
hour  in  Bussian  lbs. 


For  the 
lamp 


0-0688 
0-0688 
0-0688 
0-0676 


Per 
caodle 
power 


0HM>80 
0-0060 
0-0064 
0-0081 


Literature, — ^Hendel^e£f.  Zeitschr.  Teohnik, 
1886,  No.  109 ;  Chem.  Zeit.  1883,231 ;  Ilimow, 
ibui.  10,  1469 ;  J.  8oa  Chem.  Ind.  2,  238 ;  5, 
661 ;  6,  135  (v.  Pbtbolbum,  Russian). 

BAKURIN.  A  lubricating  oil,  prepared  by 
mixing  100  parts  of  crude  Baku  oil  with  25  parts 
of  castor  oil  and  60  to  70  parts  of  sulphuric  acid 
of  66*B.  After  standing  the  mixtujre'iB  stirred 
two  or  three  times  with  water,  the  water 
run  off,  and  the  oO  treated  with  soda  or 
potash  (Mailer,  D.  R.  P.  35141,  DingL  poly.  J. 
280,  240). 

BALAHCB.  A  raierio  term,  designating  a 
variety  of  machines  for  asoertaining  the  weight  of 
a  body  in  terms  of  the  weight,  at  the  time  and 
place,  of  a  standard  mass  (^m,  ounce,  pound, 
&0.),  and  thus  determining  its  mass.  By  means 
of  a  baUmoe  and  a  set  of  *  weights,'  we  ascertain 
that  a  body  has  P  times  the  weight  of  the  unit 
piece  of  the  set,  and  conclude  that  its  mass  Ib 
P  times  the  mass  of  this  pieoe  likewise,  whatever 
the  chemical  nature  of  the  body  may  be.  In 
justifioatioo  of  tkus  inference  we  might  refer  to 
Newton's  pendulum  experiments,  or  to  the  often 
proved  chemical  axiom  that  the  weight  of  any 
body  or  set  of  bodies  is  independent  of  the 
state  of  oombination  of  its  elements.  But  from 
the  standpoint  of  the  chemist  it  is  sufficient  to 
know  that»  supposing  even  each  element  had  its 


own  factor  for  converting  *  weight  *  into  mass,  it 
would  still  follow  that  the  weieht  of  a  body, 
however  complex,  is  equal  to  ue  sum  of  the 
weights  of  what  in  any  sense  we  may  caU  its 
*  components,'  and  that  the  ratio  of- the  weight 
W|  of  a  body  of  fixed  elementarir  composition  to 
the  weight  Wg  of  another  body  of  even  a  different 
6xed  composition  is  as  constant,  although 
perhaps  not  equal  to  the  ratio  of  the  mssoes 
M. :  Mf.  Of  all  balances  the  equal-armed  lever 
balance,  often  called  *  the  balance '  par  excel' 
lence,  is  by  far  the  most  important. 

The  balance  exists  in  a  variety  of  forms» 
all  of  which  seek  to  reaUse  the  same  ideal 
machine.  An  absolutely  rigid  beam,  so  sus- 
pended that  whilst  it  can  rotate  freely  about  a 
certain  axis  (which  goes  acroos  it  somewhere 
above  its  centre  of  gravity,  and  of  which  every 
point  holds  a  fixed  position  in  reference  to  the 
itnnd)  it  is  not  capable  of  anv  other  motion. 
From  two  points,  a  and  ft,  which  lie  in  the  same 
plane  as  the  axis  of  rotation— one  near  the  left, 
the  other  near  the  right  end  of  the  beam — the 

Sans  are  suspended  by  means  of  absolutely 
exible  linear  strings,  a  and  b  are  equidistant 
from  the  axis  of  rotation.  So  far  all  balances 
are  alike.  In  now  passing  to  the  actual  instra- 
ment,  we  shall  confine  ourselves  in  the  main  to 
the  class  of  balances  known  as  precision  baUnoea. 
Of  the  difficulties  involved  in  the  eonstruc- 
tion  of  such  balances,  that  of  producing  a  suffi- 
ciently Uffht  and  yet  practically  inflexibre  beam, 
seems  to  have  rested  most  heavily  on  the  minds 
of  the  earlier  makers;  but  there  cao  be  no 
doubt  that  many  of  their  efforts  in  this  direction, 
which  occasionally  resulted  in  what  we  should 
now  call  fantastical  beam-forms  (hollow  ellip- 
soids, monstrous  skeleton-forms,  iba),  must  be 
traced  back  to  their  inability  to  reach  a  sufficient 
degree  of  precision  in  the  geometric  adjustment 
of  the  three  pivots,  and  to  their  charging  against 
the  flexibilitv  of  the  beam  what  was  reauy  owing 
to  these  defects  in  the  adjustment.  As  these 
difficulties  were  overcome,  beams  assumed  less 
fantastic  forms.  Sacr^  of  Brussek,  we  believe, 
never  uses  any  but  plain  rod-shaped  beams  (only 
perforated  in  the  middle  to  inwrt  the  bearing 
of  the  central  knife).  Most  balance  makers, 
however,  prefer  the  form  of  a  largely  perforated 
rhombus  or  isosceles  triangle  (cut  out,  virtually, 
of  a  plate  of  metal),  and  thus  attain  all  that  is 
needrul  without  offending  the  eye  by  unduly 
stretching  the  middle  section,  and  without  using 
anything  more  intrinsically  rigid  than  hammered 
brass  or  some  kind  of  bronse.  In  refereace  to 
ordinaiy  chemical  balances  (for  charges  up  to 
say  100  grams),  it  would  be  no  great  exag- 
^;eration  to  say  that  anv  reasonably  made  beam 
IS  sufficiently  rigid ;  only  in  the  case  of  balances 
intended  for  very  high  charges,  such  as  5-10 
kilogrammes,  is  it  at  all  worth  while  to  employ 
refinedl^  designed  beam-forms,  or  to  look  out  for 
a  material  of  exceptionally  hiffh  rigidity.  For 
those  particular  balances  hara  steel  would  be 
the  best  material;  but»  unfortunately,  steel 
beams  are  apt  to  become  magnetic.  With  small 
assay-balances  intended  for  charges  up  to,  say, 
5  ^ms,  on  the  other  hand,  the  question  of 
riffidity  is  practically  out  of  court,  sad  the  use 
01  an  exceptionally  licht  material— suob  as 
aluminium,  or,  better,  that  aUo^  of  OS  parts  of 
aluminium  and  5  of  silver  (which-  Sartorkis  d 


BALANCE. 


603 


Gottingen  uees  for  small  balanoes  generally)  is 
indicated.^  In  all  balances  the  axis  of  rotation 
is  recJised  in  a  straight  knife-edge  ground  to  a 
prism  of  hard  material,  which  is  firmly  fixed  to 
the  beam,  trayersing  it  oroaswise  and  resting  on 
a  hard  bearins.  In  ordinary  balances  the  middle 
knife  is  8im]^y  driven  through  the  beam,  and 
only  its  two  ends  are  supported  in  cylindrical, 
or,  what  is  better,  roof- shaped  bearings,  which 
form  secures  to  the  edco  a  sufiicient  fixity  of 
position,  forward  and  oack  sliding  being  pre- 
vented by  cutting  off  the  ends  of  the  ]mife 
obliquely,  so  that  the  edge  terminates  in  two 
points,  and  closing  the  bearinc  at  each  end  by 
a  steel  plate,  so  that  the  knife  nas  just  room  be- 
tween without  jamminjK.  In  suspended  balances 
the  central  bearing  is  fixed  at  the  lower  end  of  a 
light  framework,  terminating  above  in  a  hinged- 
on  ring  for  suspending  the  instrument  from  a 
fixed  hook  or  the  thumb  of  the  operator. 

In  all  precision  balances  the  central  bearing 
is  attachea  to  a  fixed  pillar,  and  is  plane ;  in  the 
bert  balances  the  bearing  is  made  of  one  piece, 
and  the  central  knife-edse  rests  upon  it  m  its 
entire  length.  A  plane  oearing  necessarily  in- 
volves an  arrestment  so  constructed  that,  besides 
doing  its  primary  dutv,  it  assigns  to  each  point 
of  the  oentnl  knife-edge  a  fixMl  position  on  its 
bearin|;.  In  former  times  hard  steel  was  used 
exdusilrely  for  both  knives  and  bearings ;  sub- 
sequently agate  bearings  came  to  be  combined 
with  steel  knives.  Robinson  of  Ix>ndon  was 
the  first  to  make  both  knives  and  bearings  of 
agate.  The  agate  knife  adds  nothing  to  the  pre- 
cision of  a  newlv-made  balance,  but  it  always 
remains  clean,  while  a  steel  knife,  in  a  chemical 
laboratory  more  especially,  ia  apt  to  rust.  Steel 
knife-edges  are  generally  ground  to  an  angle  of 
60^  (or  9o^  for  very  heavy  charges).  In  agate 
knives,  as  made  by  Oertling,  only  the  body  of 
the  agate  prism  is  ground  to  60^  while  the  edge 
is  formed  oy  two  narrow  facets,  inclined  to  each 
other  at  a  far  more  obtuse  aogle.  Such  an 
obtuse  edge  stands  many  years'  constant  use 
without  wearing  out.  American  makers  have 
introduced  the  artificially  made  osmium-iridium, 
which  is  used  for  the  tipping  of  stylograph  pens, 
as  a  material  for  both  knives  and  bearings. 

For  the  realisation  of  the  two  point- pivots  a 

and  B,  a  great  many  combinations  have  been 

invented.     A    now    obsolete    construction    of 

Weber's  (Bib.  2)  adapts  itself  very  closely  to  our 

ideal  conception.    He  provides  tne  beam  at  its 

two  ends  with  knife-edges  turned  sideways  and 

suspends  the  pans  by  means  of  threads  of  unspun 

silk  which  are  fixed  somewhere  in  the  back  of  the 

beam  and  hang  over  the  edge,    llie  axis  of 

rotation    is    rMilieed    similarly.     In    ordinary 

bajanoes,  as  a  rule,  a  vertical  slit  is  cut  into  each 

end  of  the  beam,  and  this  is  traversed  by  a  short 

prismatic  knife,  the  edee  of  which  is  a  circular- 

arc  of  small  radius  whicn  stands  peipendicular  to 

the  line  ab.      ¥tom  each  such  knife  the  pan  is 

suspended  by  means  of  an  8  or  2-shaped  steel 

hook.    This  oonstmotion,  if  well  executed,  may 

affcmi  high  precision,  but  the  suspender-hook 

is  apt  to  rub  against  the  sides  of  the  slit  in  the 

beam.    Hence,     wherever     the     hook-and-eye 

arnuigement  is  adopted  for  precision  balanoes« 

it  is  modified  in  this  sense,  that  the  knife-edge 

1  7or  a  foUar  diacuBsion  of  this  subject,  v.  tLe 
writer's  Msmoir  (Bib.  0«  U2). 


forms  a  circle  of  relatively  large  radius  which  lies 
entirely  outside  the  bodv  of  the  beam.  This 
system,  compared  with  tkose  considered  in  the 
sequel,  offers  the  advantage  of  easy  adjustment. 
It  used  to  be  very  popular  with  balance  makers, 
and  many  excellent  instruments  have  been  pro- 
duced with  it  especially  by  Dcleuil  of  Paris.  For 
small  assay-balances  it  is  indeed  probably  as 
good  as  any  other  that  could  be  named ;  for 
balances  intended  for  higher  charges  it  does  not 
possess  sufficient  durability,  although,  as  the 
writer  is  able  to  say  from  his  own  experience,  if 
well  made,  it  lasts  better  than  is  generally  sup- 
posed. In  modern  balances  it  is  rarely  seen; 
in  these,  as  a  rule,  the  pans  are  suspended  from 
long  straight  knife-edges,  similar  to  the  central 
one,  by  means  of  broad  bearings  which,  of  course, 
must  be  arranged  so  that  they  neither  twist  nor 
slide.  A  very  efficient  and  easily  made  arrange- 
ment is  to  give  the  bearing  the  form  of  a  roof 
out  and  of  one  side  of  a  prismatic  block  of  steel 
or  agate,  and  to  fix  it  to  the  upper  end  of  a 
stirrup-shaped  or  "7-shaped  holaer  which  ter- 
minates below  in  an  eye,  from  which  the  pan 
is  suspended  by  a  suitable  hook.  The  eye  stands 
at  right  angles  to  the  knife-edge ;  its  working 
point,  when  the  instrument  is  in  use,  lies  verti- 
cally below  the  centre  of  the  respective  end-edge, 
and  the  effect  is  the  same  as  if  the  whole  of  uie 
load  were  concentrated  in  that  one  centre-point, 
although  the  pressure  of  the  bearing  on  the  knife 
is  equfdly  distributed  over  the  whofe  of  its  work- 
ing length.  This  hook-and-eye  arrangement  is 
absolutely  indispensable  if  the  pans  are  suspended 
by  stiff  stirrups,  because,  if  these  were  rigidly 
connected  with  their  bearings,  the  virtual  point 
of  appb'cation  of  the  load  would  shift  forwards 
and  backwards  on  the  edge,  and  the  least  want 
of  parallelism  between  it  and  the  axis  of  rotation 
would  cause  the  balance  to  give  inconstant 
readings. 

These  roof-shaped  bearings  were  formerly 
used  almost  exclusively  by  German  makers, 
although  an  undoubtedly  superior  system  had 
been  mtroduced  successfully  by  Robinson  of 
London  many  years  ago.  In  it  the  pans 
are  suspended  by  plane  bearings  which  a 
suitable  extension  of  the  arrestment  keeps  in 
their  right  positions.  Robinson's  balances 
were  justly  famous  in  Great  Britain — a  few 
of  them  are  still  working  to  this  day — ^yet, 
after  Robinson's  death,  Oertling  was  almost  the 
only  balance  maker  who  follo\ved  him  in  this 
respect.  Hie  genercd  plea  against  the  system 
was  that  flat  end-bearings  were  liable  to  twist ; 
and  some,  after  having  adopted  Robinson's  plan, 
*  improved '  upon  it  by  cutting  out  a  central 
portion  of  each  end-knife,  so  that  it  worked  only 
with  its  two  ends ;  proving  thereby  that  they 
did  not  understand  their  business,  because  a 
really  plane  bearing,  as  a  matter  of  fact,  does 
not  twist  on  a  really  eiraight  knife-edge,  even  if 
the  pan  oscillates  strongly.  The  principal 
advantage  of  the  Robinson  system  is  that  it 
enables  one  to  do  what  the  roof -shaped  bearing 
prohibits,  namely,  to  satisfy  himself  that  the 
knives  and  bearings  are  geometrically  perfect. 
But  here,  as  in  all  analogous  oases,  we  must  not 
forget  that  the  excellence  of  an  instrument — 
supposing  it  to  be  based  on  a  reasonable  system — 
dependsfar  more  on  the  skill  of  the  maker  than 
on  the  theoretioa]  perfection  of  the  design. 


004  BAU 

From  the  bare  realisBtion  ol  the  ideal 
machine,  we  DOir  jhus  U»  the  acoeBsoriea  which 
a  baliuioe  ueeda  in  order  to  become  a  convenieal 
inBtniment,  and  we  will  conudar  tbeM  in  the 
order  of  their  importance. 

Tht  arrttlmtnt  is  a  mechaniotl  oonlriTanoe 
to  enable  tbe  beam  to  be  arretted  at  anj  point  of 
its  angular  motion,  and  to  bring  it  to  permanent 
rest  in  ite  '  nomuil '  position,  in  which  the  plane 
of  three  axes  Btands  horizontaL  If  the  three 
pivota  are  self -adjusting,  there  is,  itriotly  apeak- 
mg,  no  need  of  an  arrestment ;  tiHl  for  the  rapid 
execution  of  pieoise  weighing*  it  is  almost 
indispensable. 

If  the  oenttal  bearing  forma  part  of  a  sua- 
pended  frame,  on  arrestment  is  easilv  devised  in 
the  ways  illustiated  by  Figs.  1  and  2.  Fig.  1 
explains  itseU  ;  in  Fig.  2 
the  balance  is  hinged 
on  to  the  bent-down 
end  of  a  flat  bar  wfaioh 
slides  up  and  down 
in  guides  fixed  to  the 
pillar  between  two  beds 
of  rollers  2x2  in  the 
guides  on  the  front  side 
of  the  bar,  and  one 
which  is  pressed  against 
its  back  by  a  spring. 
At  its  lower  end  the 
bar  has  a  small  wheel 
which  rests  on  the 
shorter     end     of     the 


^o*  •■  rused    or    lowered.     A 

small  vertical  adjusting  screw  below  the  shorter 

end  of  the  lever  deSnes  the  lowest  position  of  the 

bar  at  which  the  pans  just  touch  the  table 

~~''^'iout    alockening 

)rovement  to 
pend  a  heavy 
ck  of  metal  at 
lower  end  of  the 
ne,  to  compel  it 
lang  plumb,  and 
hinder  it  from 
iUating.  The 
^iGc  advantage 
tuapendtd  bal- 
es is  that  the7 
d  no  horizontal 
le  or  levelling 
iws  at  the  board 
■PjQ   3  on  which  they  may 

be  erected.  But 
pillar- balances  are  on  the  whole  more  con- 
venieiit.  In  the  c^ue  of  these  (supposing 
plane  beanngs  to  be  absent)  a  good  system 
IB  to  fix  the  central  bearing  to  the  top  of 
a  rod  which  slides  up  and  down  within  the 
pillar — properly  guided  to  prevent  shaking  and 
rotatory  motion— and,  with  its  lower  end,  rests 
on  an  eccentric  concealed  in  the  sole  and  governed  i 
by  a  lever-  or  diso-ihaped  handle.  The  eooentrio 
must  be  so  adjusted  that  when  it  is  at  one  of  ita 
extreme  positions,  the  pane  just  touch  the  boaid 
and  no  more,  while,  when  it  is  in  its  other  extreme 
position,  the  beam  is  at  it«  maximum  angle  of 
free   play.     In   the   ezoellent    Tarinoaafftn   of 


Mes-ira.  Becker's  Sons,  Bottardam,  this  system  ol 
arrestment  is  realised  to  perfection. 

The  system  needs  only  be  slightly  modified  to 
adapt  itself  to  tlie  rase  of  a  plane  central  bearing, 
but  we  prefer  to  at  onoe  pass  to  the  case  of  iXrtt 
plane  bearings,  and  in  dcmg  so  cannot  do  better 
than  descriM  a  balance  (for  charges  np  to  S 
kilos. )  which  Mr.  Oertling  made  for  ui  some  years 
Eigo.  As  shown  by  Fig.  3^  the  instrument  reals 
on   three   piltarj  standing  on  a  hollow  square 


Fio-  3. 

blook    of    iron    which   conceals   the   « 

Firmly  6xed  to  tbe  top  ends  of  the  pitlan  is  a 
substantial  brass  frame  whioh  terminates  at  ita 
two  ends  in  V-shaped  support*  for  tiie  end- 
bearings.  Theselatter  are  agate  plates  cemented 
each  to  the  horizontal  bar  of  a  kind  of  stirrup, 
the  bar  terminating  on  each  dda  in  a  oylindrioal 
steel  pin  which,  when  the  balance  is  at  rest,  lies 
in  the  corresponding  V  of  the  frame.  The 
central  pillar  conceals  a  movable  steel  rod,  fao- 
vided  at  its  lower  end  with  a  wherl  which  rests 
on  the  eccentrio.  Its  upper  end  carries  a  sub- 
stantial brass  block  which  divides  into  two  short 
tiers  above,  whilst  it  expands  below  into  m, 
arizontal  plate,  pierced  by  a  circular  perforation 
near  each  end.  These  pertorations  fit  exactly 
around  two  cylindricai  steel  pins,  r,  r,  fixed  to  the 
top  pUte  of  tbe  pillais,  so  that  the  rod,  when 
movmg  up  or  down,  cannot  turn  or  shake  in  the 
slightest  dtnee.  The  space  between  the  two 
pinra  is  brit^^  over  by  the  oentral  bearing,  a 

Elane  agate  jjate  fixed  to  a  prismatic  piece  of 
rass,  ivhioh  is  dovetailed  into  the  tops  of  the 
piers,  so  that,  while  perfectly  steady  when  in  ita 
place,  it  osn  without  much  raort  be  slid  ont  or  in 

tFig.  4).  It  is  inserted  while  the  beam  ii  being 
eld  in  its  intended  position  and  pasMS  thioush 
a  large  perforation  in  the  beam  mto  whioh  the 
midiQe  knife  projects.  The  beam  terminates  at 
its  left  end  in  one,  at  its  right  end  in  two,  horiion- 
tsl  steel  pins  whose  shouldere  are  continuous  bat 
rapidly  expanding  surfaces  of  rotation,  and  thcM 
pins  fit,  the  Blngle  one  into  a  notch,  the  oouple 
into  a  fork,  forming  part  of  tbe  fixed  arrestment 
frame.  In  the  airMted  balance  each  bearing 
is  almost  in  contact  with  its  knife ;  if  the 
eccentric  be  now  turned,  the  central  bearing 
rises  and  lifts  tbe  whole,  besms  and  end-besujnga, 
to  a  greater  oi  len  height,  and  ultimately  into 
that  mozimnm  height  at  whioh  the  eoosntiie 
stand*  still  withoat  being  Md  in  it*  poeitioD. 
If  Om  Dooentria  be  now  turned  tb»  other  w^. 


both  the  beam  and  the  end-be&ringa  tail  baoh, 
ultimatelj,  into  thnir  pt^scribed  positiona  of 
nat,  even  if  thay  tbould  bava  twisted,  which, 
however,  they  never  do  in  the  inatrument 
Dndsi  deeciiptioiL  For  a  balance  intended  for 
ijuick  worl^  and  more  eipecially  for  one  used 
ooouionally  for  the  weighing  out  of  predet«r- 
mined  qnantitiei  of  aolids  or  Gquida,  tbu  sjitem 
of  UTeetment  it  the  ben  that  we  know  of,  be- 
oanee  it  enables  the  instrument  to  be  handled 
pretty  mDoh  like  an  ordinary  pair  of  scale*  ;  oalj, 
to  be  able  to  do  so  to  the  best  advantage,  and 
without  spoiling  the  terminal  pivote,  the  pana 
muM  be  suspended  by  flexible  short-linked  ehoina 


whose  length  is  so  adjusted  that  the  pans  jnst 
touch  the  table  when  the  balance  is  fully  arreeted. 
Stirrup-shaped  pan-suspondeis  (as  represented 
in  the  figure)  are  more  convenient  than  chains 
in  many  respeote,  but,  for  the  purpose  under 
consideration,  they  do  not  work  with  plane  end- 
bearing  The  ratohet-wbeel  visible  in  the  %ara 
was  intended  to  enable  the  eocentric  to  be 
arrested  at  intermediate  positions  (in  taring  with 
garnets  and  similar  operations)  but  was  found 
not  to  work  satisfactorily ;  it  is  simpler  and 
better  to  have  a  block  of  wood  so  adjusted  that 
when  put  under  the  handle  it  just  rsiisee  the 
beam  snfGciently  to  enable  one  to  see  which  side 


Instead  of  fising  the  arraatment  frame  to  the 
pillar  and  making  the  central  bearing  movable, 
we  aay  of  course  do  the  reverse,  ana  this  latter 


^fVr 


in.  Section  thrDDgh  pIlUt  end  middit  knlte : 
iV.  Hoiltoatal  projaotlon. 
Fia.  S. 
system,  indeed,  is  generally  preferred  for  pre- 
cision bsiancee  of  a  nigher  order. 

The  tiW'^"'™'  of  Heasrs.  C.  Staudinger'a 
Kachfolger  of  Gieasen,  Germany,  enables  us  to 
give  a  oeUlled  description  and  drawing  ci  t^ 


S06 


BALANGB. 


kJxid  of  movable  iiame  arresiment  which  they 
are  in  the  habit  of  applying  to  their  best  instru- 
monta. 

As  shown  by  Fig.  6  (I.  to  IV.)  the  pillar  is 
hollow  and  accommodates  a  round  bronze  rod  f. 
This  rod  itself,  however,  conceab  a  oo-azial 
roand  rod  L  of  nickelled  steeL  The  bronze  rod 
r,  at  Its  lower  end,  is  guided  by  perfornte<l  blocks, 
<>  <»  Fig.  L,  while  at  its  upper  end  it  terminates 
in  a  thinner  cylinder  surrounded  by  a  cently 
acting  spiral  spring  it.  The  head  of  the  pular  is 
perforated  and  guides  the  attenuated  end  of  f  in 
its  up-and-down  motion.  The  inner  (steel)  rod, 
Lp  is  guided  similarly  within  the  bronze  rod  f 
and  has  a  spring  t,  I^g.  11.,  about  its  lower 
end  to  assist  its  natural  tendency  to  sink.  The 
two  rods  F  and  l  carry  two  independent  arrest- 
ment-bars ;  L  the  bar  T^  for  the  end-bearings,  F 
the  bar  T,  for  the  beam. 

A  square  pillar  K  (Figs.  III.  and  IV.),  which 
rises  from  a  prolongation  of  the  head  of  the  stand 
pillar  8,  by  passing  through  perforations  in  the 
two  ban  Ti  and  t,,  prevents  any  motion  of 
these  about  the  axis  of  their  rods.  Aa  shown  by 
Fig.  IV.,  an  adjusting  screw,  passing  through  the 
bar,  and  a  flat  spring  t  on  one  side  of  the  square 
perforation  of  the  bar  (t^  or  t,),  enforce  steadi- 
neas  of  motion. 

The  upright  pins  g  g  (L),  which  are  tipped 
with  sharp  agate  cones,  arrest  the  end-bearings 
by  rising  into  correspondinj^  conical  hollows  m 
the   latter.    (Fig.    6,   though   taken   from   an 

Oertling  balance,  will  Kive 
an  idea  of  the  way  in  which 
these  pins  work.)  The  two 
slanting  lines  0  O  (F^.  I.) 
are  meant  to  indicate 
two  supports,  which  pass 
throuffh  slota  in  the  pillar  s 
and  we  bronze  rod  F,  and 
are  fixed  to  the  inner  rod  L, 
to  lend  additional  rigidity  and  steadiness  of 
motion  to  the  end-beanngs  arrestment. 

The  arrestment  of  the  beam  is  effected  by  two 
adjustable  piers  z  rising  from  the  bar  t^  of  the 
bronze  rod.  The  tops  of  these  piers  carry  roof  • 
shaped  agate  bearings,  in  which  the  arrested 
beam  lies  with  its  lower  (bevelled)  edge.  This 
would  be  sufficient  to  keep  the  beam  from  turn- 
ing. To  hinder  it  from  moving  prosressivelv, 
there  is  a  horizontal  frame  l  (Figs.  III.  and  IV.) 
united  with  bar  t^  bv  two  little  pillars  o,  o,  and 
carrying  two  agate  bearings,  a  roof-shaped  one 
at  the  hmder  end  and  a  plane  one  at  the  front  end 
of  the  middle  (agate)  imife.  The  roof-shaped 
bearing  receives  that  end  of  the  middle  knife 
as  the  roof-shaped  bearing  of  an  ordinary 
baluioe  would  (so  that  bv  it,  and  the  two  beam- 
supports,  three  points  of  the  arrested  beam  are 
fixed  ui  prescribed  positions) ;  the  plane  bearing 
in  front  only  supports  the  Imife  as  it  rises  up  to 
it  on  arresting.  This  plane  bearing  is  adjustable 
by  means  of  a  screw,  so  that  the  arrested  central 
knife-edge  can  be  made  rigorously  parallel  to 
the  fixed  central  bearing  of  the  working  in- 
strument. 

There  are  three  eccentrics,  all  attached  to 
the  same  axis  and  governed  by  the  same  handle 
(Fiff.  IL),  one,  a,  for  the  bronze  rod  f,  a  second, 
B,  rar  the  inner  steel  rod  L,  and  a  third,  c,  for 
a  paa-aiiestment,  whose  mode  of  acting  will 
readily  be  seen  by  a  glanoe  at  Fig.  L    When  the 


Fio.  6. 


handle  stands  so  that  line  p  (Fig.  I.)  b  vertical 
the  beam  is  arrested ;  after  this  point  has  been 
passed,  the  beam-supports  remain  at  the  same 
altitude,  but,  on  turning  the  handle  further, 
bar  T,  is  raised  to  lift  the  terminal  bearings  as 
soon  as  line  q  stands  verticaL  The  last  third  of 
the  motion  of  the  handle  arrests  the  pans. 

The  principal  feature  in  Messrs.  Staudinger's 
Nachfolger's  arrestment  obviously  is  the  rela* 
tive  independence  of  the  beam-arrestment  and 
of  the  end- bearings  arrestment.  In  most 
other  movable  frame  systems  there  is  only  one 
frame  for  both,  and  thinfls  are  arranged  so 
that  the  middle  edge  is  held  fast  after  tlM  eiid- 
bearings  have  been  lifted  by  a  hair's  breadth, 
and  that  the  upward  motion  comes  to  an  end  as 
soon  as  the  middle  knife  is  just  visible  above  its 
bearing.  A  refinement  upon  this  construction  is 
to  menly  efEeot  the  three  contacts,  and  then,  by 
means  of  a  special  eccentric,  to  let  the  middle 
bearing  drop  through  a  distance  of  0*1  or  0-2  mm. 

Wmlst  ful  the  several  points  of  a  riffid  thou||h 
movable  arrestment-bar  move  up  and  down  m 
vertical  straight  lines,  the  end-edges  of  the  vibra- 
ting beam  describe  circular  arcs.  Hence  when- 
ever, the  bar  is  raised  against  the  Wanting  beam, 
the  end-bearings  tend  to  slide  over  their  knives 
and  to  spoil  them.  To  preclude  the  possibility 
of  tfajs,  Becker  ft  Sons,  m  their  finest  balances, 
make  the  bar  for  the  end  bearings  arrestment  of 
two  halves  which  are  hinged  on  to  the  pillar  in 
or  very  near  the  axis  of  rotation.  Sartorius 
adopted  this  system  and  brought  it  into  a  sli^tlv 
different  form,  regardinff  which  we  refer  to  BibL 
4,  where  it  is  illustratea  by  a  drawing. 

In  a  balance  which  has  only^plane  bearing 
no  kind  of  arrestment,  of  course,  will  give  satis- 
faction, unless  its  several  parts,  and  also  the 
pillar  and  the  sole,  are  sufficiently  substantial  to 
ensure  absolute  constancy  of  configuration  and 
absolute  steadiness  of  motion  even  after  long- 
continued  use.  The  old  masters  used  to  pay  great 
attention  to  this  important  point,  but  it  is  sadly 
neglected  by  the  majority  of  their  present  suc- 
cessors. 

In  a  balance  of  which  the  end-pivots  are  self- 
adjusting,  the  movable  arrestment  frame 
assumes  a  very  simple  form.  All  that  is  needed 
is  a  small  frame  bearins  V-shaped  notches  for 
arresting  the  middle  Imife  in  a  prescribed 
position,  and  fixed  to  a  horizontal  bar  with  two 
projecting  pins,  in  order,  at  the  same  time,  to 
support  uio  beam  in  a  horizontal  position.  As 
these  pins  have  no  other  function,  the  bar  may 
be  very  light,  and  the  whole  system  need  not 
have  that  absolute  steadiness  A  motion  which 
is  indispensable  in  the  case  of  plane  end- 
bearings. 

The  needU  aifd  scale  serve  to  define  the 
angular  position  of  the  beam.  In  all  modem 
precision  balances  the  needle  points  downwards, 
and  is  meant  to  embody  a  straight  lin0  pMsing 
through  the  axis  of  rotation  and  standing*  per- 
pendicular on  the  line  connecting  the  two  point 
pivots  A  and  b.  The  scale  is  attached  to  the 
pillar ;  its  zero,  if  the  Mand  is  properly  levelled* 
lies  vertically  below  the  axis  of  rotation.  To 
enable  the  stand  to  be  levelled,  there  must  be 
either  a  plumb  line  or  two  spirit  levels  fixed  to 
(he  piOar,  and  so  adiusted  that  when  they  point 
to  their  zeros,  the  line  oonneoting  the  aero  of 
the  scale  with  its  proJeotioQ  on  the  middle 


%ALANC& 


607 


edge  is  TerticaL  The  scale  should  be  so  gradu- 
ated that  the  needle-line,  if  produced,  would 
cut,  DOt  the  circle  described  bj  the  needle's 
reference  point,  but  the  horiionUl  tangent  to 
this  cirde,  into  pieces  of  equal  length  (v.  infra). 
In  most  practical  cases,  howerer,  this  comes  to 
the  same  as  saying  *  into  pieces  of  equal  angular 
value.'  In  balances  provided  with  a  fixed  arrest- 
ment frame  the  scale  should  be  made  to  move  up 
and  down  with  the  beam,  so  that  its  position  in 
reference  to  the  needle  remains  constant.  In 
most  balances  the  end-point  of  the  needle  is 
just  clear^>f  the  upper  circular  edge  of  the  scale, 
but  it  is  better  to  make  its  lowest  portion  almost 
linear,  and  let  this  project  over  the  scale  and 
almost  touch  it. 

The  ridtr. — Small  weights  are  difficult  to 
handle  and  easily  lost.  To  avoid  this  incon- 
venience, Berzelius  conceived  the  happy  idea  of 
dividing  the  right  aide  of  the  beam,  or  rather  the 
horizontal  lever  arm  corresponding  to  it»  into  ten 
equal  parts,  and  substituting  one  rider  weighinj; 
ten  centigrams  for  all  the  centigram  and  milli- 
^am  pieces  of  the  set  of  weights.  Obviously  the 
rider,  when  suspended  at  the  first,  second,  ^kc 
mark  from  the  centre,  acts  like  1,  2,  &o.  centi- 
grams placed  in  the  pan,  and  it  is  equally  obvious 
that  every  tenth  of  a  division  on  the  beam  corre- 
sponds to  one  milUgram  of  additional  weight. 
This  system  was  universally  adopted  and  is  still 
in  use,  only  with  this  <}ualmoation,  that  we  now 
apply  it  to  the  oountmg  of  the  milligrams  by 
means  of  a  rider  weighing  ten  milligrams.  The 
reason  for  the  change  is  obvious.  In  most 
balances  the  points  0  and  10  of  the  rider-scale 
are  inaccessible.  Becker  &  Sons  avoid  this 
inconvenience  by  dividing  the  arm  into  twelve 
parts,  and  supplying  a  rider  weighing  twelve 
milligrams.  Otner  makers,  for  instance,  Messrs. 
Verlwek  &  Peckholdt,  of  Dresden,  make  the  top 
bar  of  their  beams  exactly  horizontal,  and, 
besides  keepins  it  dear  of  impediments,  make  it 
project  beyond  the  terminal  edges.  One  of  the 
advantages  of  this  svstem  is  that,  in  the  case  of 
a  short  Mam,  it  enables  us  to  double  the  degrees 
of  the  rider  scale,  by  dividing  each  arm  into  only 
five  (integer)  parts,  numbenng  these  from  the 
left  knife  onwards  and  using  a  rider  weighing 
five  miUisrams.  Only,  if  we  do  so,  the  rider 
suspendea  at  tiie  zero  must  be  counted  part  and 
pai^  of  the  instrument.  Bunge  provides  a 
spedal  rider-bar  so  contrived  that  the  path  of 
the  rider  lies  in  the  plane  of  the  three  axes.  This, 
iheoreiicdUy^  is  the  most  perfect  arrangement. 

A  rider  arrangement,  to  be  complete,  must  be 
supplemented  by  a  mechanical  contrivance  en- 
abling one  to  shift  the  rider  while  the  balance 
case  18  dosed,  and  to  do  so  with  ereater  rapidity, 
ease,  and  certainty  than  would  be  afforded  bv  a 
forceps,  suppoeins  the  case  to  be  open.  Ri(2er- 
guidee  fulmmig  this  latter  condition  are  scarce ; 
even  with  the  best  the  rider  drops  down  occasion- 
ally, and  has  to  be  searched  for. 

To  avoid  tins  source  of  annoyance  Hempd  does 
away  with  the  rider  and  substitutes  for  it  a  vane 
with  a  limb  graduated  into  milligrams  (v.  infra). 

The  gravity  &o&— a  small  button  or  disc  of 
metal  so  attached  to  a  wire  standing  vertically 
on  the  top  of  the  beam  exactly  above  the  axis  of 
rotation -that  it  can  be  screwed  up  and  down 
along  the  whole  range  of  the  wire.  It  enables 
one  to  raise  or  lower  the  centre  of  gravity  of  the 


beam,  and  thus  to  establish  any  desirable  degree 
of  sensibility. 

A  bob  thus  constructed  meets  all  the  require- 
ments of  the  balance  maker,  but  for  the  chemist 
who  uses  the  balance  it  is  desirable  to  have  an 
arrangement  which  enables  him  at  a  moment's 
notice  to  establish  any  predetermined  degree  of 
sensibility.  Such  an  arrangement  was  invented 
by  the  writer  some  years  ago  (BibL  8  and  5).  It 
consists  of  a  small  bob  fixed  by  mere  friction 
to  the  upper  end  of  the  needle,  which  at  that 
part  has  the  form  of  a  triangular  nrism,  and 
is  provided  with  a  naduation.  llie  mods 
of  standardising  the  soUe  is  explained  below. 

Seme  arrangewumi  for  MJahiiihing  perfect 
equilibrium  in  the  unloaded  instrument  is  re- 
quired. A  small  bob  screwing  along  a  horiiontal 
wire  fixed  to  some  convenient  part  of  tha  beam 
answers  best.  Less  convenient  is  a  *  vane,' 
meaning  a  little  movable  horizontal  lever  at* 
tached  to  the  lowest  point  of  the  wire,  which 
carries  the  ordinary  gravity-bob,  or  to  the 
upper  part  of  the  neecue.  To  understand  the 
working  of  the  vane— and  at  the  same  time  that 
of  Hempd's  invention  above  referred  to — sub- 
stitute for  the  vane  an  equivalent  rigid  Une 
(Fig.  7).    If  the  vane-line  stands  in  the  position 


00 — 1.«.,  if  it  is  paralld  to  the  middle  knife— it 
adds  no  weight  to  either  side,  if  turned  through 
00*  into  position  0  (10),  it  virtually  adds,  tot 
us  say,  10  milligrams  to  the  charge  of  the  right 
pan.  Divide  the  line  0  ( 10)  into  ten  equal  parts, 
erect  an  ordinate  in  each  point,  and  you  find  the 
points  0,  1,  2,  3,  &c.,  of  the  ciroular  path  of  the 
end-point  of  the  vane,  to  which  the  vane-line 
must  point,  if  the  virtual  addition  to  the  right 
pan  is  to  be  equal  to  0;  1,2..  ..10  milligrams.  A 
glance  at  the  figure  shows  one  weak  point  in  the 
vane  contrivance.  There  is,  however,  no  need 
of  our  dividing  the  ciroular  limb  exactly  in  the 
way  of  our  figure.  We  may,  for  instance,  place 
the  zero  at  the  —7  and  the  ten  at  the  -f  7  of  our 
figure^  divide  the  interval  betfween  the  projec- 
tions on  line  (10)  {W)  of  -f-7  and  ^7  into  ten 
equal  parts,  and  so  adjust  the  mass  of  the  vaqe 
and  its  distribution  that,  by  turning  it  from  the 
new  zero  (at  —7)  to  the  new  '  10 '  (at  +7),  we 
virtually  add  10  milligrams  to  the  right  eharge. 
The  d^rees,  corresponding  each  to  1  milligram, 
then  become  so  nearly  equal  to  one  another  that 

# 


606 


BALANCE.  ^ 


the  Bubdiviflion  of  each  into  ten  parts  of  equal 
angular  value  is  permissible. 

Ths  Thsobt  ov  thx  Balanob. 

For  a  first  approximation  imagine  a  balance 
which  is  ideally  perfect^  and  assume  it  to  be 
charged  with  r  grams  from  the  left  and  with 
P  grams  from  the  right  point  pivot.  The 
balance,  when  free  to  vibrate,  can  remain  at  rest 
in  only  its  normal  position,  »nd  if  brousht  out 
of  it  wUl  vibrate  about  it  as  a  pendulum.  Because 
the  two  charges  are  CNqnivaJent  statically  to 
one  heavy  particle  weighing  2P,  situated  in 
•  the  central  Imife-edge.  Kow,  put  a  small  over- 
weight A  on,  say,  the  right  pan  ;  the  position  of 
potential  rest  will  shift,  and  the  beam,  to  reach 
it,  must  turn  (downwards  on  the  right  side) 
through  a  certain  uur le  a,  which  depends  only 
on  A  and  on  the  weight  W  of  the  empty  beam, 
which  latter  we  may  assume  to  be  concentrated 
in  its  centre  of  gravity  o,  the  force  2P  being 
obviously  out  of  consideration.  But  the  two 
weights,  A  at  b  and  W  at  o,  are  equivalent  to  a 
point  weighing  W+A  aud  lying  on  the  straight 
line  ob  at  a  point  o",  not  far  from  a  The  new 
position  of  rest  is  gained  as  soon  as  ff  lies  verti- 
cally below  the  axis  of  rotation,  or,  to  put  it 
in  other  words,  the  right  side  of  the  beam  goes 
down  until  the  levenupe  of  a  is  so  far  reduced 
and  that  of  W  has  so  &r  increased,  that  the  two 
momenia  tUUiea  are  equal  to  each  other. 

.  Imacine  dow  the  axis  of  rotation  were  shifted 
verticaUv  upwards  through  a  small  height  h,  but 
remained  parallel  to  itself.  The  imaffinazy  point 
weighing  2P  now,  as  soon  as  the  beam  turns, 
haa  a  lever  and  helps  the  weight  W ;  the  beam 
will  turn  through  a  less  angle  a'  to  gain  its  new 
position  of  rest,  and,  supposing  2P  to  increase, 
a'  becomes  leas  as  2P  increases. 

Imasine  now  the  axis  of  rotation  to  be 
shifted  downwards  towards  the  centre  of  gravity. 
The  heavy  point  weighine  2P  grams  now  helps 
A,  and  the  angle  which  -separates  the  two 
positions  of  rest  will  become  greater  than  the 
original  angle ;  the  greater  2P  the  greater  ^^ill 
be  the  actual  angle  a".  But  the  two  weights,  W 
concentrated  in  o,  and  2P  concentrated  in  the 
centre  of  the  line  ab,  taken  jointly,  are  equi- 
valent to  one  point  &  weighing  W+2P  granu, 
and  situated  on  the  straight  line  connecting  the 
two  points;  and  supposing  2P  to  increase 
gradually  from  nil  onwards,  (/,  in  the  second 
case,  will  rise  and  rise,  and  at  a  certain  value  of 
2P  fall  into  the  axis  of  rotation.  The  balance 
then  has  no  definite  position  of  rest ;  and  if  o' 
rises  still  higher,  the  oalance  upsets.  However 
small  an  overweight  A  may  be  put  on  either  side, 
the  beam  would  have  to  turn  upside  down  to 
reach  its  one  (theoretical)  position  of  stable 
equilibrium. 

The  balance  maker  of  course  takes  care  so 
to  adjust  his  instrument  that  even  if  the  sensi- 
bility is  at  the  highest  value  which  the  balance 
is  meant  to  affora,  and  the  two-sided  charge 
2P  at  its  maximum  likewise,  the  centre  of 
gravity  of  the  whole  system  lies  on  the  safe  side 
of  the  axis  of  rotation. 

Assuming  this  condition  to  be  fulfilled,  the 
balance  to  be  exactly  equal  armed  and  to  be 
charged  with  a  pan  weiffhinff  Pq  grams  and  a 
load  of  p  grams  on  each  sioe,  the  angle  a  of 
deviation  is  govei^ied  by  the  equation 


where  I  stands  for  the  arm-length,  §  fof  the 
distance  of  the  centre  of  gravity  of  the  empty 
beam  from  the  axis  of  rotation,  and  k  for  the 
distance  of  the  axis  of  rotation  from  the  plane 
of  the  two  end-edges,  the  axis  being  assumed  to 
lie  above  the  plane.  In  the  opposite  case  h  must 
be  assumed  to  be  negative,  or  the  plus  sign 
before  the  second  term  in  the  denominator  be 
replaced  by  a  minua  sign.  But  Iga  is  the  ntio 
of  the  absolute  length  of  scale  (measured  tan- 
gentially,  v.  supra)  conesponding  to  aoffle  •  to 
the  distance  1  of  the  tangent-sero  fromthe  axis 
of  rotation.     Hence  we  have 

aZI 

"-W«  +  3(p,+y)A°'^-'^'       •  W 

where,  supposing  I  to  be  measured  in  tangential 
scale  degrees,  n  may  be  read  as  meaning  the 
number  of  degrees  through  which  the  needle 
turns  in  consequence  of  the  addition  of  A.  The 
product  condensed  into  *  E '  wa  will  call  .the 
sensibility.* 
The  reciprocal  of  E,  i.e.  the  number  E~' 

n^,  is  the  weight- value  of  1  degree  of  the  scale 

— I.e.  the  particular  A  which  makes  naal. 
With  a  precision  balance  the  milligram  is  a 
convenient  unit  for  A. 

For  a  balance  provided  with  the  writer's 
auxiliary  bob,  eq.  (2)  may  conveniently  be 
brought  into  the  form 

(W^-f2PAj-f6(y,+y) 

II  •  KM) 

where  b  is  the  weight  of  the  bob  and  y^+y  the 
distance  of  its  centre  of  gravity  from  the  axis  of 
rotation  y^  being  that  distance  which  prevails 
when  the  nob  is  at  its  highest  (zero)  position. 
In  a  well-made  balance  the  influence  of  P  on  £ 
is  small ;  we  may  therefore  assume  the  P  of  the 
equation  to  be  some  average  value,  and,  con- 
tracting constants,  say,  the  weight-value  of  one 
degree  is 

E->-A  +  By       .         .         (8) 

where  A  and  B  are  constants ;  A  obviously  beins 
that  value  which  E->  assumes  when  yaO.  —  B 
is  easily  determined  by  one  trial  at  yato  its 
maximum,  and  the  scale  thus  standardised. 

Th€  theory  of  the  rider  might  be  allowed  to 
take  care  of  itself  if  in  general  practice  the 
rider's  path  exactly  coincided  witu  the  plane 
of  the  tbre^  axes.  But  such  is  not  the  case : 
this  path,  as  a  rule,  lies  above  the  plane,  ana 
each  mark  at  its  own  altitude  H.  Let  us  thera- 
fore  assume  that,  after  the  balance  had  been 
charged  with  P  on  each  side,  a  rider  weighing 
p  hM,  been  suspended  at  a  point  of  the  beam 
corresponding  to  the  fraction  Id  of  the  arm- 
length  (at  the  lOk)^  mark  counting  from  the 
centre).  If  the  beam  stand  horizontal,  and  a 
weight  hp  be  placed  in  the  opposite  pan,  the 
beam  wUl  remain  in  equilibrium,  because  we 
have  lipk)=p{kl)  whatever  H  may  be  ;  the  rider 
whore  it  is  and  the  charge  kp  (virtually)  in  the 
left  knife-edge  are  conjointly  e(^uivalent  to  a 
fixed  point  weighing  ^p+P*  i^nd  situated  on  the 
straight  line  joinine  the  left  edge  and  the  point 
(lOk)  where  the  rider  is.  And  thitf  equivslenoe 
holds  for  the  slanting  beam  as  well,  and  is  inde- 


n 


tv** 


BALANCE. 


609 


pendent  of  P.  But  the  sensibility  of  the  beam 
with  the  rider  on  is  evidently  greater  than  It 
was  with  the  rider  off.  Statically  speaking, 
the  weight  of  the  beam  and  the  two  charges  P 
and  P  are  eqnivalent  to  a  fixed  point  Cq  weigh- 
ing W'«=W-f 2P,  and  situated  vertically  below 
the  axis  of  rotation  at  a  distance  So,  and  this 
particle,  conjointly  with  the  one  embodied  in 
the  rider,  is  equivalent  to  a  point  weighing 
\7^2P+p,  and  situated  on  the  straight  line 
between  Co  and  the  point  where  the  rider  sits. 
Referring  to  a  system  of  rectangular  co-ordinates 
whose  A-azis  passes  throush  the  centre  of  the 
eentral  edge  and  is  paralld  to  AB,  and  whose 
Y-axis  passes  through  the  same  centre,  we  have 
for  the  position  of  the  resultant  point  the 
equations 

*(W'  +p)='lkp;  and  y( W  +  p)  «  W'*o  -  pH 

We  see  that  if  H  be  constant — t.e.  if  the  rider- 
path  be  parallel  to  the  plane  of  the  three  axes — 
iga  is  proportional  to  tne  overweight  kp  virtu- 
ally added  to  the  charge  of  the  right  pan ;  but 
it  is  as  well  to  notice  that  the  tga  oF  our  equation 
\s  different  from  the  {iga)^  which  is  brought 
about  if,  instead  of  hanging  the  rider  on  the 
{]Oky^  mark,  we  actually  put  kp  units  into  the 
right  pan.    Obviously 

With  a  rider  weighing  only  10  milligrams,  and, 
say,  a  hectogram  balance,  the  term  pH  in  the 
denominator  comes  to  very  little,  but  With  a 
rider  of  ten  times  the  weight  it  (as  a  rule)  can 
no  longer  be  neglected;  such  a  rider  cannot 
conveniently  be  used  unless  H  is  constant  and 
the  rider  must  always  hang  at  the  balance  (at 
its  zero,  over,  say,  the  central  knife  when  it  is 
not  used  as  a  weight),  or  else  the  sensibility 
has  one  value  with  the  heavy  rider  on  and 
another  with  the  rider  off.  Another  requisite  is 
that  notches  cut  into  the  beam  be  substituted 
for  mere  marks,  and  that  the  rider  have  a  sharp 
edge  to  give  sufficient  constancy  of  position  to 
its  point  of  application. 

From  what  we  have  said  so  far,  it  would 
appear  that  in  a  balance  provided  with  a  gravity- 
bob  we  can  give  the  sensibility  any  value  we 
may  fancy.  And  so  we  can,  but  it  does  not 
follow  that  we  can  command  any  desired  degree 
of  precision.  Because  the  tmree  edeee  and 
bearing  are  not  what  they  ought  to  oe,  and, 
as  a  bttle  reflection  shows,  the  effect  of  their 
defects  is  the  same  as  if,  say,  the  length  of  the 
right  arm,  instead  of  being  at  the  constant 
vuue  ),  osdllated  irregularly  between  2— X  and 
I+X>  where  x  is  a  very  smaU  length,  which 
increases  when  W  and  P  increase,  but  is  inde- 
pendent of  L  And  this  again  is  the  same  as 
if  X  were  nil,  but  the  charge  of,  say,  the  right 
side,  instead  of  being  at  a  constant  value  P, 
varied  irregularly  from  P— t  to  P+c.  In  a 
g|iven'  balance  charsed  with  a  given  P  at  each 
side  c  is  constant^  but  the  corresponding  angle 
of  deviation  fi  varies  when  the  sensibility  varies. 
Within  this  angle  0  the  balance  is,  so  to  say,  in 
a  state  of  indifferent  equilibrium.  By  going  a 
little  more  deeply  into  the  matter,  we  easily 
satisfy  ourselves  that,  even  allowing  for  the  fact 


that  we  cannot  substitute  a  longer  for  a  shorter 
beam  without  increasing  the  beam-weight,  e  will 
increase  when  I  becomes  less.  In  a  balance 
meant  to  afford  a  certain  degree  of  precision, 
we  cannot  allow  the  arm  length  to  fall  below 
some  (very  uncertain)  value  of  ^o* 

A  glance  at  eq.  (2)  would  show,  if  it  were 
not  clear  without  it,  that,  if  the  three  axes  lie  in 
exactly  the  same  plane— 4.e.  if  h^O — ^the  sensi- 
bility becomes  mdependent  of  the  charge, 
which  is  a  great  convenience.  But  A  obviously 
cannot  be  equal  to  n»{  at  all  chai|[es ;  hence  in 
the  case  of  the  best  instruments  it  is  regulated 
BO  that  it  has  a  small  negative  value  when  only 
the  pans  are  suspended,  and,  by  the  unavoidable 
deflection  of  the  beam,  becomes  nil  at  some 
suitably  selected  medium  oharse,  so  that,  from 
this  charge  upwards,  it  has  small  positive  values. 
That  such  a  degree  of  precision  cannot  be 
attained  by  purely  constructive  methods  goes 
without  saying;  indeed,  any  precision  balance 
requires  to  be  *  adjusted '  before  it  is  fit  to  be 
used.  For  this  purpose  the  value  of  the  h  corre- 
sponding to  the  medium  charae  and  the  ratio 
of  the  actual  arm-lengths  I' :  r  must  be  deter- 

V 
mined  and  the  errors  h  and  w,^l  corrected. 

For  the  direct  geometric  measurement  of  h 
special  apparatus  have  been  constructed,  which, 
in  their  present  form,  we  believe,  afford  a  suffi- 
cient degree  of  precision;  but  the  final  test 
always  is  (or  at  least  was  until  lately)  at  a  suit- 
able position  of  the  bob,  to  determine  the  weight- 
value  B~^  of  one  degree  of  deviation  for  a  series 
of  charges,  say,  p^O,  50,  100  grams,  ftc,  up 
to  the  maximum  charge  which  the  balance  is 
intended  to  measure ;  and  to  at  least  virituilly 
calculate  the  corresponding  values  h  by  means 
of  eq.  (2).  Whether  h  is  positive  or  negative, 
is  oi  course  seen  from  the  values  £~^  without 
calculation.  Supposing  now  h  has  a  greater 
value  than  can  be  tolerated,  one  of  the  Knives 
must  be  lowered  or  raised  until  at  a  certain 
medium  charge  the  three  edges  are  as  exactly 
as  possible  in  one  plane.  Most  mechanicians 
provide  adjusting  screws  for  this  purpose  whicli 
enable  one  to  work  in  a  systematic  manner. 
Some,  however  (for  instance,  Becker  &  Sons, 
following  the  example  of  Deleuil),  prefer  to  fix 
all  the  Knives  definitely  and  to  alter  the  form 
of  the  beam  ilself  by  means  of  the  hammer.  If 
the  central  edge  has  to  be  lowered,  the  lower 
bar  of  the  beam  is  struck  (on  both  sides) ;  if  it 
is  to  be  raised,  the  upper  bar  is  struck,  until  the 
correction  is  presumably  almost  but  not  quite 
completely  effected.  The  values  £~*  are  then 
again  determined,  and  if  they  are  not  suffi- 
ciently near  one  another,  the  hammerins  is 
renewed  until  the  adjustment  Is  perfect.  In  a 
similar  manner  (or  by  means  of  adjusting 
screws)  the  two  arms  are  made  equal  to  each 
other.  The  test  here  is  very  simple.  The 
balance,  after  having  been  brought  to  the 
highest  degree  of  sensibility  which  it  will  stand 
at  the  highest  chai^  P,  is  charged  with  exactly 
P  grams  on  each  side.  The  longer  arm  goes 
down,  and  by  determining  the  small  over- 
weight which  must  be  added  to  the  other  side  to 
establish  equilibrium,  we  can  easily  determine  the 
ratio  {' :  V  numerically.  All  these  adjustments 
are  effected  by  the  mechanician,  and  when  once 
effected  are  final.    Some  mechanicians — ^for  in- 


510 


BALANCE. 


stance,  the  Beokers— fix  even  the  oentre  of 
gravity,  but  this  is  a  mistake.  A  balance,  to  be 
complete,  must  have  a  movable  '  bob  '  to  enable 
the  operator  to  give  the  sensibility  that  value 
which  suits  him  best.  What  degree  of  sensi- 
bility should  we  choose  ?  Answer :  In  general, 
the  lowest  degree  which  suffices  for  the  purpose 
in  hand.  Supposing,  for  instance,  we  can  neglect 
the  half-milligram,  it  is  of  no  use  to  screw  up  the 
bob  any  hi^^er  than  necessary  for  rendering 
the  angle  of  deviation  corresponding  to  0'5  mil- 
ligram conveniently  visible  and  no  more,  because 
the  less  the  sensibility,  the  greater  the  ran^  of 
weights  determinable  by  the  method  of  vibnu 
tion,  the  greater,  as  is  easily  shown  from  eq.  (2), 
the  relative  independence  of  the  sensibility  from 
the  charge,  and  last,  not  least,  the  less  the  time 
of  vibration.  The  time  of  vibration  can  of 
course  not  be  allowed  to  faU  below  a  certain 
minimum,  or  else  the  centres  of  gravity  of  the 
charges  will  not  be  able  to  follow  the  oscillations 
of  the  beam  with  sufficient  promptitude.  But 
this  clause,  with  larger  balances  wrought  at  Ugh 
precision,  ususJly  takes  care  of  itself.  The 
exact  relation  in  a  balance  between  the  time  of 
vibration  i  (in  seconds)  and  ths  sensibility  £  is 
given  by  equation : 

(•  «  ^|*W  +  2P}-E      .         .  (6) 

where  R  is  the  length  of  the  mathematical 
pendulum  beating  seconds  at  the  place  of  obser- 
vation, P  the  total  charge  on  one  side,  and  k 
a  numerical  factor,  ibWZ*  being  the  momentum 
inerti<B  of  the  empty  beam.  With  the  customary 
perforated  rhombus  or  triangle,  k  is  very  nearly 
equal  to  I.  From  the  equation  we  clearly  see  that 
with  a  *  bob  *  of  sufficient  range  we  can  choose 
our  own  time  of  vibration  or  our  own  sensibility, 
but  we  cannot  choose  both,  in  a  ready-made 
balance.  It  stands  differently  with  a  balance  to 
be  eongtructed.  To  avoid  indefiniteness,  let  us 
assume  that  we  wished  to  design  a  balance  for 
weighing  quantities  up  to  100  grams  with  a 
toleration  of  0*1  mgr.  Let  us  assume  also  that 
we  had  made  up  our  minds  regarding  the  mate- 
rial and  the  general  form  for  the  beam,  and  that 
we  had  defined  the  latter  so  that  the  relation 
betweeii  arm-length  2,  and  weight  W,  were  in 
accordance  with  an  equation  of  the  form 

W  =  C-fBI    .         .         .    (7) 

where  W  includes  the  empty  pans,  C  designates 
the  conjoint  weieht  of  sll  that  which  is  inde- 
pendent'of  I ;  and  B  stands  for  the  weight  of  the 
rest  if  the  arm-length  2=1.  Our  equation  now 
assumes  this-form 


<««^{c«  +  2j>  +  w}b    . 


.  (8) 

where  p  stands  for  the  charge  in  each  pan. 
This  equation  affords  some  guidance  in  the 
selection  of  I.  Assuming  for  E  a  value  which 
renders  the  decimiUigram  just  visible,  and 
taking  p^O,  we  substitute  for  t  the  smallest 
admissible  value  and  solve  our  equation  in 
recard  to  2.  Of  course  I  cannot  be  allowed  to  fall 
bdow  that  mihimum  l^  {v.  supra)  at  which  the 
inherent  error  would  rise  to  anything  like  0*1  mgr. 
Where  does  this  limit  value  l^lieJ  Staudinger 
used  to  draw  the  Une  at  200,  Oertling  at  180 
millimetres,  and  similar  values  were  adopted  by 
other  makers,  until  Bunge,  some  twenty- five 
yean  ago,  showed  in  the  most  direct  manner 


posable  that  a  sufficient  degree  of  constancy 
can  be  attained  with  an  arm-length  of  as  little  as 
60  millimetres.  Thanks  to  the  general  excdlenoe 
of  Bunge's  work  his  short  beams  soon  became 
very  popular  with  chemists,  and  the  fact  that 
almost  all  other  German  makers  have  since  come 
to  adopt  the  Bunge  system  shows  that  the 
additional  perfection  in  the  pivots  which  the 
short  beam  undoubtedly  demands  is  not  so 
difficult  to  realise  as  an  outsider  might  be  in- 
clined to  think.  Assuming  this  diffcuUv  to  be 
wercome,  it  cannot  be  denwd  that  the  short  in 
opposition  to  the  long  beam  does  offer  certain 
advantages.  Ist.  It  is  relatively  lights  and  hence 
the  working  of  the  arrestment  is  a  less  effort.  2nd. 
It  is  less  liable  to  irregularities  through  one-sided 
elevation  or  depression  of  temperature.  Perhaps 
we  may  add  that,  3rd,  it  is  easier  in  its  case  than 
in  that  of  the  long  beam  to  make  a  smooth- 
working  arrestment,  and  on  this  account  chiefly 
it  enables  one  to  weigh  more  quickly.  4th,  and 
least  in  our  opinion,  it  vibrates  more  quickly. 
Not  that  we  value  this  last  advantage  at  nothing. 
The  writer's  auxiliary  bob  indeed  was  invented 
with  the  veiy  object  of  remedying  the  corre- 
sponding defect  in  the  older  tomiS  the  instru- 
ment, being  originally  intended  to  be  used  thus. 
In  the  outset,  place  tne  bob  far  down,  say  to  the 
mark  where  1^  of  deviation  corresponds  to  2 
mgrs.  or  some  other  value  securinff  great  rapidity 
of  vibration,  and  establish  equilibrium  as  far  as 
thus  possible.  Then  raise  the  bob  to  the  mark 
at  which  1*B=0-1  mgr.,  allow  to  vibrate,  shift  the 
rider  correspondingly,  and  verify  3rour  result. 
The  uTiter,  however,  soon  came  to  find  this 
method  less  convenient  than  he  had  expected, 
and  adopted  another  very  obvious  expedient. 
It  is  easy  in  any  beam  to  bring  down  we  time 
of  vibration  to  the  least  value  one  could  reason- 
ably wish  for  by  screwing  down  the  bob  to  the 
corresponding  place.  Tiub,  of  course,  may 
render  the  decimiUigram  invisible  to  the  naked 
eye.  But  why  not  help  the  eye  by  optical 
means  7  An  ordinary  lens  magnifying  six  times 
linearly  affords. more  than  there  is  any  occasion 
for;  only  it  magnifies  the  paraUactic  eaot  as 
well,  and  the  effort  to  avoid  this  error  strains  the 
eye  very  unpleasantly.  This  experience  led  the 
writer  to  the  following  oombination»  which  he 
found  to  give  perfect  satisfaction.  A  narrow 
ivory  scale  divided  into  degrees  of  about  0*1  mm. 
is  fixed  slantingly  to  the  needle  pretty  far  down, 
yet  far  enough  up  for  not  obscuring  the  ordinary 
scale  which  does  duty  as  usual ;  on  the  other 
hand,  a  c6mpound  microscope  of  feeble  power, 
which  passes  throuffh  the  central  fixed  portion  of 
the  front  pane  of  we  case,  is  fixed  slantingly  to 
the  piUar,  The  microscope  has  one  vertical 
'  wire  *  in  its  focus  which  acts  as  a  needle.  As 
the  microscope  inverts  its  images,  the  apparent 
motion  of  the  wire  in  reference  to  the  scale 
(which  one  easily  persuades  himself  is  fixed)  is 
the  same  in  sense  as  the  real  motion  <rf  the 
needle  in  reference  to  the  ordinary  scale,  so 
that  mistakes  in  regard  to  the  -f  and  —  are 
avoided.  The  ordinary  scale  is  mduated  after 
the  micro-scale  so  that  each  of  its  degrees  is 
equal  in  angular  value  to  10*  of  the  latter. 
The  writer  some  five  years  ago  caused  Ifr. 
Oertling  to  apply  this  arrangement  to  two  ol 
his  baluicee,  and  he  has  found  it  to  work  very 
satisfactorily.    Although  it  was  originally  in* 


BALANCE. 


611 


tended  chiefly  for  special  oceasioiia— the  adjust- 
ing of  weights,  &c. — it  is  used  even  for  our  every- 
day work,  as  it  was  found  that  the  mioroeoope 
puts  a  less  strain  on  the  eye  than  the  naked-eye 
roading  of  the  ordinary  scale.  The  micro- 
aoopic  arrangement  described  adds  about  ZL  to 
the  cost  of  the  balance.  A  cheaper  arrangement 
is  the  following.  A  micro-scale,  divided  con- 
veniently into  fifth- millimetres,  is  fixed  slantingly 
to  the  pillar,  the  needle  at  the  oonespondmg 


part  ia  shaped  thus. 


f- 


and  a  hair  by  means 


of  capillary  perforations  is  stretched  out  between 
a  and  b ;  the  hair  is  parallel  to  the  face  of  the 
scale,  and  only  some  0*2  to  0-5  mm.  removed 
from  it.    A  short  terrestrial  telescope,  fixed  in 
the  central  (fixed)  part  of  the  front-pane  of  the 
case,  serves  for  the  readings.    The  object  glass 
serves  only  to  produce  an  image  of  the  spalo  and 
hair  within  the  tube,  which  the  eye-piece  (a 
compound  microscox)e)  magnifies  as  far  as  neces- 
sary.   As  the  telescope  need  not  be  perfectly 
steady,  it  can  be  fixed  at  a  relatively  low  cost 
We  have  used  this  arrangement  in  connection 
with  one  of  our  balances  for  over  two  yeaw,  and 
found  it  to  be  almost  as  good  as  the  one  first 
described. 

Ok  thx  Settiito  vt  avd  Tssmro  of  a 
Precision  Balance. 

A  real  precision  balance,  to  be  able  to  do 
justice  to  itself,  must  stand  on  a  very  steady 
support,  in  a  room  where  it  is  not  exposed  to 
one-sided  changes  of  temperature,  llio  light 
should  fall  in  from  the  back  of  the  observer. 
The  best  support,  of  course,  ia  a  pillar  of  masonry, 
standing  directly  on  the  earth.  Next  after  it 
(in  a  BubstantiaUy  built  building)  comes  a  shelf 
fixed  to  the  wall  by  strong  brackets.  A  good 
heavy  table,  however,  suffices  in  practice.  In 
a  laige  city  the  street  traffic  becomes  very  in- 
convenient in  weighing.  Its  e£Foct  can  be 
minimised  by  putting  small  pieces  of  thick 
vulcanised-niober  plate  between  the  le^  of  the 
case  and  the  table.  In  the  examination  of  a 
newly  set-up  balance  we  naturally  begin  by 
seeing  that  the  arrestment,  the  rider-shiftinc 
apparatus,  &c.,  are  in  good  order,  we  then  level 
the  case,  and  next  leave  the  balance  to  itself 
for  some  four  hours  at  least,  to  enable  it  to 
acquire  the  temperature  of  the  room.  After 
these  preliminaries  we  proceed  to  the  foUowing 
determinations. 

DetermifuUion  of  the  inherent  error  c. — For 
this  purpose  we  charge  the  balance  equally 
on  both  sides  with  the  highest  weight  which  it 
IB  intended  to  measure  (a  hectogram  balance,  for 
instance,  with  a  hundred-gram  piece  on  each 
side),  and  after  having  established  approximate 
equUibrium  at  the  highest  degree  of  sensibility 
which  the  balance  will  stand  at  this  charge  with- 
out giving  obviously  inconstant  readings,  deter- 
mine the  exact  position  of  rest,  first  with  the 
two  heoto^ms  in  the  centres  of  their  pans, 
and  then,  m  a  series  of  successive  experiments, 
with  one  or  other  of  the  hectograms  placed 
at  some  point  of  the  edge  of  its  pan  so  as  to 
give  any  non-parallelism  in  the  axes  or  any 
other  cfefect  in  the  terminal  pivots  a  good 
chance  of  influencing  the  result,  taking  care  to 


interpolate  occasionally  an  experiment  with  the 
two  weights  centrally  placed  in  order  to  see  if 
the  balance  still  gives  the  same  readings  aait  did 
at  first.  If  it  does  not,  this  is  probably  owing  to 
external  causes,  such  as  unequal  heating  of  the 
two  arms.  To  be  able  to  translate  degrees  of 
deviation  into  difierenoes  of  weight,  we  must  at 
some  stage  make  two  successive  determinations 
of  the  position  of  rest,  one  with  P'  in  the  left 
and  P"  in  the  right  pan  (F  and  F'  stand  for  the 
two  hectogram- pieces)  and  another  with,  say, 
one  milligram  added  to  F'.  For  the  precise 
determination  of  a  position  of  rest,  we  cause  the 
balance  to  vibrate  moderately,  and  (neglecting 
the  first  reading  as  being  in  general  liable  to 
irregularities),  record  3,  5,  7  .  .  .  successive 
turning-points  of  the  needle,  applying  a  -f  to 
scale-points  lying  to  the  left,  and  a  ~  to  soale- 
points  lying  to  the  right  of  the  aero  (or  vice 
vereA) ;  an  odd  number  in  any  case  in  order  to 
correct  for  the  retarding  effect  of  the  resistance 
of  the  air,  Ac. ;  those  influences,  in  other  words, 
through  which  the  needle,  supposing  it  to  start 
from  —4*,  at  the  end  of  a  douole  vibration,  does 
not  come  back  to  exactly  —4*,  but  perhaps  to 
—3*7*.  The  algebraic  sum  of  any  two  succefe- 
sive  readings  gives  the  point  a  of  the  scale  at 
which  the  needle  would  come  to  rest,  in  half- 
degrees,  and  there  is  no  reason  why  the  huf- 
de^pree  should  not  be  adopted  as  a  convenient 
unit  for  the  purpose  in  hand.  Supposing  the 
readings  to  be 

0|  tty  Oj  a|  tt^- 

(Example)  +3-7     -2-7     -f-3'5     -2-4     +3-5 
we  have  for  a  the  values  :  ai+O} =  + 1  '0 ;  a|+t^ 
=  +0-8;   a,+04=  +  l-l;   a4+a|a  +  M— Mean 

=+io. 

The  mean  value  of  the  four  results  is  put 
down  as  the  value  of  a.  Supposing  a,  throush 
the  addition  of  A  milligrams  to  the  right 
charge  to  increase  by  n  demi-degrees,  then 

E  =  -( =:  2  *  £ '  in  the  sense  of  our  equation 
(2) )  is  the  sensibility  in  domi-degrees  ;   and  its 

reciprocal  E-*  =  ~(™  oE  *  '  *  ®'  ©quation  (2)] 

the  weight-value  of  the  demi-degree  in  milli- 
grams. Supposing  the  values  for  a  obtained 
with  abnormal  positions  of  the  charges  to  be 
a,,  a,,  a,,  &o.,  instead  of  the  mean  value  a^, 
corresponding  to  the  centrally  placed  chaises, 
then  (Ot--ai)E-*=»i,  (ao— aj)K-'=t;„  Ac,  give 
each  a  value  for  the  inconstancy  of  the  balance 
in  milligrams  (or  rather  fractions  of  a  milli- 
ffram,  it  is  to  be  hoped).  According  to  a  rule 
deduced  from  the  law  of  frequency  of  error,  the 
computation 


0-845     ,     ,       ,       . 


Vn(n-1) 


.) 


where  all  the  v's  must  be  taken  as  positive, 
gives  the  *  probable '  weight- value  of  the  devia- 
tion of  any  one  a  from  a^  meaning  that  value  of 
(a,— a)E-^  which,  in  a  very  large  number  of 
determinations,  is  as  often  exceeded  as  not 
reached.  But  in  practice  the  number  of  deter- 
minations made  is  never  sufficiently  great  to 
bring  out  anything  like  a  close  approximation 
to  the  law,  and  it  suffices  to  take  r  as  being  equal 
to  0*845  times  the  mean  of  aU  the  values  v,  and 


612 


BALANCE. 


»  I 


adopt  it  as  sufficiently  near  to  the  theoretical ' «. 
The  probability  that,  in  a  given  case,  (Oq— a)E'-^ 

€XC€€ds 

2f  3r  4f  5r 

is  018        0O4        0-007        0-0007 
respectively. 

7n  these  determinations,  if  the  balance  lacks 
a  microscopic  reading  arrangement,  it  is  as  well 
to  read  from  a  distance  with  a  telescope,  to  avoid 
the  parallactio  eiror  which  we  have  no  right  to 
cham  against  the  balance. 

VeUrminatum  of  h, — All  that  is  necessary  is 
to  determine  the  weight  value  of  one  degree  in 
the  sense  of  equation  (2)  for,  say,  |>b100,  75, 
50,  25,  0  grams,  and  to  calculate  the  corre- 
sponding values  A.  In  a  good  balance  A  is  so 
small  that  (supposing  our  rule  rmrding  the 
adjustment  of  the  bob  to  be  followed)  the  sensi- 
bility remains  almost  constant  from  p^O  to 
pes  100  grams.  Hence,  practically,  it  suffices 
to  adjust  the  bob  so  that  at  a  convenient  average 
charge  (where  *  average '  refers  to  the  mc«t 
frequently  occurring  values  of  p)  one  demi- 
degree  corresponds  to  say  (  or  }  of  a  milligram 
exactly,  and  then  to  see  what  it  is  at  other 
charges.  If  there  is  no  sufficient  constancy  we 
enter  the  values  E— '  found  on  a  system  of  rect- 
angular co-ordinates  in  function  of  the  charges 
p,  and  draw  the  nearest  curve  to  the  points, 
lliis  curve  (if  h  were  absolutely  constant)  would 
be  a  straight  line.  In  any  case  it  sup]^lies  the 
data  for  a  table  of  values  for  E->.  This  table, 
however,  must  not  be  relied  on  in  dandard 
weighings,  because  the  value  h  is  subject  to 
changes,  for  this  reason  amon^t  others,  that  the 
aeate  of  the  knives  has  a  different  coefficient 
of  expansion  from  the  metal  of  the  beam. 

The  arm-lengths. — ^For  the  determination  of 
the  ratio  of  tiie  arm-lengths,  the  orthodox 
method  (for  a  hectogram  balance)  is  to  adjust  two 
hectogram-pieces  to  exact  equality,  and,  after 
havinff  estfJbliriied  equilibrium,  to  put  one  into 
the  left  and  the  other  into  the  right  pan,  ko. 
But  in  practice  the  following  method  is  better. 
Take  any  two  fairly  well  aajusted  hectograms 
and  viewing  them,  one  as  a  standard  representing 
100,000,  the  other  as  an  object  weighing  x  miUi- 
grams,  go  throush  the  ordinary  operation  of 
weighing  once  with  the  object  in  the  left  pan  and 
the  standard  in  the  right,  and  once  the  otner  way. 

Supposing  (using  8  as  a  symbol  for  100,000 
milligrams)  we  find 

xV  -(S-f  a|)f     •         .        .         .    I 
xl"  -  (8  H-  9tW      .         .         .         .11 
(where  any  9  may  be  negative),  we  have  b^  divi- 
sion of  I  Dy  II,  and  subsequent  multiphcation 
with  I" :  l\ 


v\*    s-f-y 

'8  +  8, 


(9 


whence,  m  a  sufBcient  spproxiiiuttioii. 


V 


+»('-^) 


No  maker  who  has  a  name  to  lose  would 
care  to  send  out  a  precision  balance  in  which 

l^Z  is  more  than  ±0-00005  at  the  outside, 

although  for  any  scientific  purpose  a  considerably 
greater  error  could  be  tolerated.     The  corre- 


sponding adjustment  indeed,  while  of  the  first 
importance  in  commercial  balances,  in  precision 
balances  is  in  a  sense  irrelevant. 

Unsqual-abmed  Lbvsb  Balaitcxs. 

(1)  The  steelyard  or  Roman  balance. — In  it 
only  the  shorter  arm  (of  the  length  I)  bears  a 
pan;  the  longer  arm,  by  notches  cut  into  its 
oack,  is  divided  into  puts  of  equal  length,  I 
being  the  unit.  The  worldng  points  or  lines  of 
the  notches  should  lie  in  the  plane  of  the  two 
edges,  being  so  many  bearings  for  the  knife-edge 
forming  part  of  a  sliding  weight  adjusted  to  r 
units.  The  unloaded  buance  is  in  its  position 
of  rest  when  the  beam  stands  horizontal.  To 
wei^h  a  body,  it  is  placed  in  the  pan  and  the 
sliding  weiffht  shift^  forwuds  from  notch  to 
notch  until  (when  the  weight  hangs  at  the 
distance  nl  from  the  axis  of  rotation)  the  beam 
is  again  at  rest  in  its  horizontal  position.  We 
then  have  for  the  weight  sought 

xls^nlP  or  ««"nP. 

As  fully  explained  above,  the  principle  of  the 
steelyard  is  discounted  in  the  modem  precision 
balance  for  the  determination  of  small  differ- 
ences of  weight.  In  theory  there  ia  no  objection 
to  its«exten8ion  to  the  determination  of  weights 
generally,  but  the  technical  difficulties  to  be 
overcome  are  great.  On  an  equal-armed 
balance,  whose  b^m  is  divided  into  100  equal 
parts  (from  end  to  end),  all  weights  from  0*0001 
to  100  grams  might  be  determined  with  three 
riders  weighing  half  of  (100,  1,  and  0-01)  gram 
respectively,  but  the  realisation  of  101  exact 
pivots  is  no  small  matter.  Where  relatively 
high  precision  is  aimed  at,  it  is  better  to  provide 
omy  a  small  number  of  notches  (say  10)  and 
have  a  set  of  riders,  weighing  say  10,  1,  0-1, 
0-01  grams  respectively.  The  specific  gravity 
balances  of  Westphal  of  Oelle,  are  made  on  this 
principle.  It  strikes  us  that  the  steelyard 
principle  might  be  discounted  for  the  decimal 
subdivision  of  weights,  thus  : 

Imagine  a  precision  balance  whose  two  arms 
measure  101  and  III  units.  10  grams  placed 
in  the  pan  of  the  longer  arm  are  balanced  by 
10 -f  1  grams  placed  in  Uiat  of  the  shorter ;  hence 
a  1 -gram  piece  may  be  adjusted  after  two  exact 
10-gram  pieces,  &o. 

The  tangent  balance  has  only  one  short  arm, 
from  which  the  pan  is  suspended ;  its  centre  of 
cravity  lies  low,  so  that  the  momentum  staticum 
Ws  of  the  beam  assumes  a  high  value,  and  even 
a  considerable  weight  placed  in  the  pan  produces 
only  a  moderate  angle  of  deviation.  The  needle 
moves  along  a  circular  limb  divided  so  that 
the  readings  are  proportional  to  the  tangents  of 
the  respective  angles  of  deviation,  and  give  the 
corresponding  weights  directly.    The  equation 

A«*— ,—  (see  equation  (1),  above)  holds  theo- 
retically for  any  value  A,  but  the  an^lar 
deviation  corresponding  to  1  gram  of  additional 
charge  becomes  less  and  less  as  the  charae  in- 
creases. The  tangent  balance,  though  usenil  for 
the  rough  weighing  of  letters,  parcels,  Ac,  is  not 
available  for  exact  gravimetric  work. 

COHPOUVD  LSVBB  BaLAXCVB, 

In  all  these,  practical  convenience  and  rapid 
working  are  gained  at  the  expense  of  precision.  In 


the  Rdbtnal  boJiMCe   the  pans  are  BboT«  the 
■yatem  of  leven  (which  u  »  rale  is  concealed 
Q  ID  a  box),  BO  that  there 
is  room  for  bodice  of 
even     large     dimen 
■ions.     Our   diagrun, 
-^b  Pig'  B.  IB  intended  to 
Mplaiii  only  the  pnii- 
rijlt  of  the  machine, 
which  in  practice  aa- 
suin«e      an      endleea 
Fio.  8.  variety  of  forma. 

The  beam  coiiHist«  of  two  parallel  vertical 
parailelograma  of  which  only  the  front  one  ia 
repreaented  in  our  flgnre.  T  and  /  (and  ■*  and 
/'  in  the  other  paraJteloaram)  are  fixed  pivotB, 
1.,  B,  a  and  h  (i',  a',  a',  b',  behind)  are  movable 
jointa.  On  each  aide  a  horizontal  bridge  con-  Ti 
necta  a  point  d  on  the  vertical  aide  «a  (and  a  4 
aimilar  point  on  b6)  with  a  oorreaponding  point 
d'  on  the  back  parallelogram  (so  that,  for  in- 
■tanoe^  Ao,  a'o',  dd'  form  one  piece)  and, 
from  the  oentrea  of  theae  bridgea,  vertical  rods 
arise  which  support  the  pana.  Supposing  each 
pan  to  bo  chaiged  with  F  pODoda,  the  centre 
of  gravity  of  either  of  theae  two  equal  charges 
may  lie  in  any  of  a  great  many  poaitiona  about 
the  cespeottve  pan,  yet  the  statical  efiect  is  the 
same  aa  if  it  were  concentrated,  one  in  the  centre 
of  the  one  bridge,  and  the  other  in  the  cuitie  of 
the  other ;  the  two  charges  will  balanoe  each 
other,  b^nae,  if  the  oentre  of  gravity  of  one 
deaocnds  by  h  mm.  that  of  the  other  riaea  by 
h  mm.,  BO  that  the  work  PA  is  the  same  on  both 
sidea.  An  over-weieht  added  to  one  of  the 
chafes  will  bring  down  that  side.  The  bars 
AM  toA  a'b'  are  relatively  heavy  beams,  the 
lower  bars  a&  and  a'b'  are  light.  Hence  it 
depends  chiefly  on  the  distribution  of  the  mast 
in  the  beams  ab  and  a'b'  whether  tbe  balance 
(if  nearly  eqnally  charged)  has  a  definite  posi. 


each  side  of  the  beam.    The  middle  band  lies 
below  the  plane  of  the  two  end  band*  by  about 


but  e 


t  has.  It  will  never 


vibrate  like  an  ordinary  balance,  on  account  of 
the  great  friction  in  the  numerous  pivots.  If  it 
eoold  only  be  eared  of  this  defeot,  the  Roberval 
woidd  be  the  ideal  baiajioe  for  the  counter  or 
ordinary  weiahings  in  the  laboratory.  This 
problem  has  been  to  some  extent  solved  in  the 
tonioD  balance  of  Springer,  in  which  the  axes 
are  realised  in  ttretchea  out  horiiontal  bands 
of  elaatic  steel,  whiob  act,  so  to  say,  aa  knivea 
and  bearings  in  one. 

Tbe  '  loTfion  balance '  is  made  ■  in  a  groat 
variety  of  forms,  but  the  principle  of  conatruction 
ia  the  aame  in  alL  The  following  detoriptioD  is 
baaed  npon  the  examination  of  what  was  aold  as 
a  bigb-claaa  pair  of  counter -sea  Irs  for  loads  up 
to  20  Iba.  Aa  shown  by  Fig.  0,  the  balance  con- 
sists of  two  parallel  beams  united  into  a  flexible 
parallelogram  by  means  of  three  vertical  frames, 
the  bond  of  union  in  tbe  case  of  each  frame  con- 
sisting  of  two  horizontal  band*  of  elastic  steel, 
which  bridge  over  certain  gape  of  the  frames, 
the  middle  portion  of  each  band  being  firmly 
united  with  the  rcspeotive  beam  end  at  it*  lower 
side  1^  means  of  a  serewed-on  block  of  metaL 
In  thia  inatmment  the  beam*  measure  200  mm. 
from  end  pivot  to  end  idvot,  the  steel  bands  are 
6'6  mm.  broad  and  0-«l  mm.  thick ;  the  length 
of  the  working  part  of  a  band  is  68  mm.,  Z9  on 
'  BrthaTorakmBalaiMaandBeale  Company,  BZErodi 
Street.  Hew  Yoik. 

Vol-  L— r. 


2  ram.     Tia  central  frame,  which  does  ae 
a  pillar,  is  fixed  to  the  sole  of  the  inst.     _   .   . 
tbe  end  frames  sre  fixed  only  to  their  respecUve 
beam  ends.     Fig.   10,  which  is  drawn  to  scale. 


B',  where  they  a  .  _ 
To  give  them  the  reonisite  degree  of  hleh  tension, 
the  frame,  of  which  part  of  the  ri^t  side  it 
movable,  is  stretched  laterally  (by  means  of  pegs 
fixed  to  the  two  sidea  of  a  vice  and  alippM 
through  the  two  holea  of  the  frame)  and  the  sap 
which  is  thus  produoed  between  the  two  ha^e* 
of  the  right  si^  of  the  frame  is  made  permanent 
by  means  of  metal  plate*  wed^  into  it.  The 
central  frame  is  somewhat  difteientl^  shaped 
from  the  lateral  ones ;  the  upper  rmg,  r,  I* 
omitted,  to  oiable  the  upper  beam  tf>  pass  freely 
through  between  the  legs  o(  a  stool  fixed  to  tbe 
lower  and  termloatbig  in  a  verHwl  peg  which 


514 


BALANCE. 


than  a  pound,  can  be  raised  or  lowered  to  enable 
the  sensibility  of  the  instrument  to  be  varied. 
The  system  of  beams  is  inclosed  within  a  case 
of  plate-glass ;  the  top  plate  supports  an  arch 
made  of  a  metal  tube  irom  which  an  ivory  scale 
graduated  on  both  sides  is  suspended  vertically 
so  that  its  lower  edge  runs  through  a  notch  in 
the  upper  eharpened  end  of  the  needle  to  enable 
the  viorations  to  be  read  from  either  side. 

To  explain  the  working  of  the  instrument, 
let  us  for  a  moment  substitute  for  the  steel  bands 
BO  many  linear  wires,  which,  though  unbondable, 
offer  no  resistance  to  torsional  dlsB^pirement. 
The  torsion  balance  thus  modi6ed  is  m  theory 
identicaJI  with  the  ideally  perfect  *  Robsrval,' 
and,  if  the  centres  of  gravity  of  the  beams 
are  in  their  axes  of  rotation,  tne  parallelogram 
will  be  in  a  state  of  indifferent  equilibrium  at 
any  shape  which  it  may  assume.  To  give  it  a 
definite  position  of  rest,  we  must  either  shift  (let 
us  say  one  of)  the  centres  of  gravity  vertically 
downwards,  or  else  we  must  endow  our  ideal 
wires  with  torsional  elasticity,  which,  of  course, 
brings  us  back  to  the  actuaJ  instrument.  But 
the  torsional  elasticity  of  the  steel  bands  is  very 
considerably  more  tlian  we  want ;  its  effect  on 
the  sensibility  is  the  same  bb  if  (supposing  the 
upper  beam  is  suspended  at  its  centre  of  gravity) 
that  of  the  lower  lay  at  a  very  considerabto  depth 
below  its  axis  of  rotation.  To  give  the  balance 
a  sufficient  degree  of  sensibility,  we  must  raise 
the  centre  of  gravity  of  say,  the  lower  beam, 
until  the  stability  of  the  position  of  rest  is  reduced 
to  a  sufficiently  small  value.  In  the  actual  in- 
strument this  is  effected  by  means  of  the  heavy 
gravity  bob  above  referred  to. 

The  principal  advantage  claimed  for  the 
toraion-balance,  in  oontr^istinction  to  the 
Boberyal  balance,  is  its  freedom  from  friction ; 
and  this  advantage  it  undoubtedly  possesses,  but 
it  is  compensated  for  to  a  large  extent  by  the 
unavoidable  viscosity  in  the  elastic  bands.  The 
instrument  described  above,  when  equally 
charved  on  both  sides,  and  with  the  bob  suffi- 
oiently  far  down,  vibrates  like  a  precision  balance 
of  a  high  order ;  the  position  of  rest  as  calculated 
from  a  series  of  couples  of  successive  deviations 
of  the  needle,  is  remarkably  constant  up  to  at 
least  a  charge  of  6  kilos,  on  each  side ;  but  once, 
when  we  determmed  the  sensibility  at  first  with 
no  charge,  then  at  a  charge  of  2  kilos.,  and  lastly 
for  a  oharffs  of  5  kilos.,  and  then  redetermined 
the  sensibility  of  the  unloaded  instrument,  we 
found  that  it  was  out  of  equilibrium  to  the  extent 
of  more  than  a  decigram.  We  also  found  that 
the  reading  of  the  balance  is  not  quite  indepen- 
dent of  the  position  of  the  loads  on  the  pans. 

The  ordinary  decimal  balance,  as  used  for  weigh- 
ing heavy  loads,  is  a  combination  of  levers  as 
shown  in  Fig.  11.  a,  b,  e,  d,  e,  f,  g,  h,  are  all  joints 
or  pivots ;  a  ,  « 


and  h  rest 
on  the  fixed 
framework  of 
the  machine 
and  conse- 


Suently  in-  ^-$ 
irectly  on 


R 
to 


the    ground,  ^^^-  ^^• 

c  rests  on  the  lever  ah.  In  the  actual  machine 
cd  supports  the  bridge  which  accommodates 
the  load,  while  a  pan  suspended  at  /  receives 


the  weights.  The  pan  is  so  adjusted  that  \% 
counterpoises  the  bridge.  Suppose  the  load 
amounts  to  P  units  and  its  centre  of  gravity 
lies  vertically  above  t ;  a  portion  Pe  presses  on 
the  knife-edse  at  c  and  thcrest  P^  =  P— Pc  pulls 
at  d  and  with  the  same  force  at  g»  Now  Pe  pull- 
ing at  c  is  equivalent  to  a  less  force  ^Pc  pulling  at 

etc 
b,  and  bPo .  a6  =  Po.  oc,  whence  bP.  s=Po -^.  But 

ao 

bPe  pulling  at  6  or  «  is  equivalent  to  a  crcater 

force  gPo  pulling    at  g  and    gP«.  yA=bPe«  ^; 

eh      ab 
The  dimensions  are  so  adjusted  that  zr  *=  zr 

whence   "t  •  rr  =*  1 »  hence  the  joint  effect  of 

Pe  and  Pd  at  (7  is  the  same  as  if  they  both,  ».e. 
P,  were  suspended  at  g  ;  and  if,  for  instance,  gh 
is  \  of  A/,  \^  P  units  in  the  pan  will  balance 
the  P  units  lying  on  the  bridge.  In  many 
balances  of  this  kind  the  long  arm  hj  is  divided 
so  that  lesser  weights  can  be  determined  by 
means  of  a  rider. 

Elasticity  Balances. 

Imagine  an  elastic  solid  body — beam,  wire, 
spiral,  &c. — ^to  be  held  fast  in  one  or  more 
fixed  points,  and  suppose  some  one  other  point 
a  to  oe  used  as  a  pivot  for  the  suspension 
of  a  load  of  P  unit's.  Point  a  will  sink  until, 
at  a  certain  depth  h,  ^he  strain  developed  by 
the  deformation  of  the  working  body  balances 
that  weight  P.  As  long  as  the  workine  body  is 
not  stretched  beyond  its  Umi^  of  perfect  elas- 
ticity, the  length  &,  if  not  proportional  to,  is  at 
least  a  fixed  ranction  of  P ;  hence  the  path  of 
a  can  be  graduated,  at  least  empirically,  so  that 
each  point  of  the  scale  corresponds  to  a  fixed 
number  of  units  of  weight.  This  is  the  general 
principle  of  the  multitude  of  spring  baUineeM, 
Sometimes  a  relatively  strong  spring  is  used  to 
effect  only  a  small  displacement  of  a  even  with 
the  highest  charge,  but  this  displacement  is 
then  multiplied  by  a  system  of  levers,  so  that 
the  least  difference  of  weight  which  the  balance 
is  meant  to  show  becomes  visible.  In  a  very 
neat  kind  of  spring- balance,  which  has  become 
popular,  the  displacement  of  a  is,  by  means  of 
levers  and  a  toothed  wheel,  translated  into  the 
circular  motion  of  a  needle  which  moves  along  a 
divided  circular  limb  like  the  hands  of  a  clock 
on  their  dial. 

Jolly  constructed  a  ^luwt  precision  spring- 
balance  for  6p.gr.  determinations  thus  : — ^A  long 
spiral  of  wire  is  suspended  vertically  in  front 
of  a  vertical  millimetre-scale^  etched  on  a  strip 
of  plate  glass  which  is  silvered  behind,  so  as  to 
avoid  the  error  of  parallax.  Prom  the  lower  end 
of  the  spiral  a  light  pan  is  suspended  ;  the  index 
is  close  above  the  pan  at  a  convenient  point. 
The  instrument  has  never  come  into  general 
use,  because  any  second-class  precision  balance 
beats  it  in  every  sense.  A  similar  remark 
applies  to  an  ingenious  little  instrument  invented 
by  Ritchie  for  the  determination  of  minute 
weichts. 

llitchie^s  balance  consists  of  a  very  light 
beam  whose  axis  of  rotation  passes  through  its 
centre  of  gravity,  and  which  js  firmly  united 
with  a  thin  horizontal  wire  which  lies  in  the 


BALANCE. 


615 


axis  of  rotation.  The  hind  end  of  the  wire  is 
abaolntely  fixed  to  the  stand;  the  front  end 
forms  the  continuation  of  the  axis  of  a  ciroular 
pin  revolvable  within  a  oircolar  bearing.  A 
needle  fixed  radially  to  the  pin  points  to  a 
divided  circular  limb.  The  empty  babuioe  is  sq 
arranged  before  use  that  the  beam  when  hori- 
Eontal  is  at  rest.  To  determine  a  small  weight 
(x  mgr.),  it  is  placed  in,  say,  the  right  pan,  and 
the  wire  turned  from  the  right  to  the  left  by 
turning  the  pin  until  after  the  needle  has  passed 
through  a  degrees  (where  «  may  be  more  than 
360^) ;  the  beam  is  again  at  rest  when  horizontal. 
We  then  have  zsconst.  a.  The  constant  must 
be  determmed  by  experiments  with  known 
weights.  Sartorius  of  Gottingen  used  to  apply 
thenitchie  arrangement  ta  his  precision  balances 
for  the  determination  of  differences  of  weight 
from  10  mgrs.  downwards  (BibL  5),  but  he  has 
long  since  given  up  the  notion  :  at  aivy  rate  it  is 
no  longer  to  be  seen  in  his  price  list.  A  Ritchie 
bnlance  might  perhaps  do  well  for  the  adjusting 
of  small  weights,  but  a  small  precision  steclyara 
would  work  infinitely  better. 

Sartorius*  combination,  if  provided  with  a 
relatively  strong  wire,  might  make  a  handy 
instrument  for  the  rapid  (approximate)  deter- 
mination of  weights  without  the  use  of  any 
standard  mass  less  than  1  gram. 

The  Htdsostatio  Balancb 

is  a  hydrometer  provided  with  a  relatively  large 
body  and  a  narrow  neck,  and  so  adjusted  that  it 
weighs  considerably  less  than  its  own  volume  of 
water.  The  top  end  of  the  neck  bears  a  hori- 
zontal table,  which  serves  as  a  pan,  or,  what  is 
Hotter,  is  provided  with  a  horizontal  system  ol 
oroes-bars,  from  ^ose  ends  a  pan  is  suspended 
by  means  of  wires  or  chains,  below  the  shelf 
supporting  the  vessel  containing  the  floating 
hydrometer.  A  certain  weight  P,  placed  in  the 
pan,  brings  down  the  hydrometer  so  far  that  the 
surface  of  the  water  touches  a  certain  mark  on 
the  stem.  If  an  unknown  .weight  x  requires  to 
be  supplemented  by  standard  weights  equal  to  p 
units,  to  produce  the  same  effect,  x+p^F,  or 
xbP— p.  Even  for  Pa  let  us  say  2  lolos.,  the 
neck  need  not  be  thicker  than  an  ordinary 
knitting  needle,  so  that  the  milli^m,  as  a  differ- 
ence of  weight,  becomes  perceptible.  Wherever 
a  precision  balance  has  to  be  extemporised 
this  instrument  is  useful ;  but  it  has  no  other 
raison  d'Stre,  Indeed  of  all  the  multitude 
of  machines  which  the  science  of  mechanics 
places  at  our  disposal  for  the  measurement  of 
weights,  the  equal-armed  lever-pendulum  is  the 
only  one  which,  so  far,  has  worked  satisfactorily 
for  precise  gravimetric  determinations. 

A  halanu  based  on  dynamical  prineipUs  has 
been  proposed.  Imagine  a  pendulum  provided 
with  a  sniftable  bob  above  the  fulcrum,  and 
carrying  a  pan  attached  to  the  bottom  end  of  ^e 
rod  Dy  a  hook-and-eye.  In  a  given  instrument 
the  time  of  vibration  is  a  function  of  the  distance 
of  the  bob  from  the  fulcrum,  and  of  the  weight  x 
of  the  object  in  the  pan,  and  consequently  Uie 
weight  a;  is  a  function  of  the  other  variables. 

Bibliography.-~{l)  Leonhard  Euler:  First 
Development  of  the  Theory  of  the  Balance; 
Trans,  of  the  Petersburg  Academy. 

(2)  WiUulm  Weberi  Balance:  G5ttingen 
golehrte  Anzeigen  for  1837,  287.    Description 


and  Drawing  in  Garrs  Reporiorium  fiir  physi- 
kalische  Technik,  1, 18. 

(3)  HSwenhen :  Report  on  Metrological 
Instruments  in  Bericht  uber  die  wissenschaft- 
lichen  Apparate  auf  der  Londoner  Ausstellung  in 
1876 ;  Braunschweig,  1881.  Vacuum  Balances, 
223-232.  Balance  Beams,  232-237.  The 
Pivots :  Modes  of  Fixing  the  Knives,  237-245 ; 
Bearings,  246-247 ;  Arrestments,  248-253. 

{4)  LOwenherzi  Zeitschrift  fur  Instrumen- 
tenkunde  for  1881,  125 ;  Report  on  Sartorius* 
Hinged  Axrestment  Frame. 

(5)  LOwenherz;  same  Journal,  year  1881, 
184w  A  Report  on  Apparatus  for  Measuring 
Small  Weights  by  the  Torsion  of  Wires :  Hooke, 
Ritchie,  Sartorius.  Full  drawing  of  Sartorius' 
contrivance  on  p.  188. 

(6)  Dittmar;  Waage  des  Chemikers;  same 
Jonnial,  year  1881,  313-326. 

(7)  Dittmar;  same  Journal,  yoar  1882,  63; 
Mikroscopische  Ablesungsvorriohtung  fQr  feine 
Waagon. 

(8)  Dittmar ;  R  Soo.  Ed.  Proc.  for  1876 ; 
Chem.  News,  33, 157.  W.  D. 

On  HiaHLY  Rifikbd  Wbiordto. 

Introductory. — In  the  late  Professor  Dittmai^s 
article  {vide  supra),  typical  forms  of  the  preciuon 
and  other  balances  have  been  considered : 
the  theory  of  the  balance  and  the  conditions 
necessary  for  accurate  work  in  general,  have  also 
been  duly  treated.  In  the  present  article,  it  is 
therefore  unnecessary  to  add  more  than  a  con- 
sideration of  some  exceptional,  but  absolutely 
indispensable,  precautionary  measures  adopted 
when  we  desire  to  reach  that  which  some  may  be 
inclined  to  term  an  ultra-degree  of  refinement 
of  weighing. 

This  article  is  bas^  chiefly  upon  results 
obtained  during  two  researches,  which,  for 
successful  issue,  demanded  more  than  usual 
care.  The  subject  was  of  necessity  studied 
from  the  severely  practical  point  of  view ;  and 
few,  if  any,  of  the  remarks  tbftt  follow  have  their 
foundation  in  pure  theory  alone.  The  following 
points  are  severally  diBcussed : — 

(1)  The  Balance  Room. 

(2)  The  Balance  Table. 

(3)  The  Levelling  Screws. 

(4)  The  Scale. 

(5)  The  Illumination  of  the  Scale. 

(6)  Of  possible  Variations  in  the  Level  of  the 
Bench. 

(7)  The  Telescope  and  its  Carriage. 

(8)  Of  the  Necessity  for  Fati^;uing  the  Beam. 

(9)  Device  for  Maintaining  Uniformity  in  the 
Temperature  of  the  Beam. 

(10)  Temperature  Coefficients  of  a  Balance. 

(11)  Suppression  of  Air-Streams  about  the 
Pans. 

(12)  Concerning  the  Wiping  of  Glass  Vessels. 

(13)  Of  Certain  Precautions  to  be  taken  in 
Weighing  Glass  Vessels. 

(14)  Determination  of  the  Pressure  Co- 
efficients of  Glass  Globes. 

(16)  Of  the  Different  Methods  for  Weighing. 

(16)  Errors  attending  the  Weighing  of  Hot 
Bodies. 

(1)  The  Balance  Boom, — ^The  balance  room 
should  be  upon  the  basement :  and  in  selecting 
it,  the  choice  should  fall  upon  one  having  a  north- 
easterly aspect :    for  then  comparatively  little 


018  BALi 

of  the  uutTument  and  that  of  the  balance  pointer 
are  in  one  and  the  aame  horiKontal  line,  and  they 
are  coatained  by  a,  vertical  plane  common  to 
both. 

With  the  tiltometer  placed  aa  indinated,  it 
is  evident  that  BJiy  vertical  movemente  of  the 
levelling  screws  resulting  from  a  flexure  of  the 
bench,  are  also  impacted,  and  in  the  Bume  degree, 
to  the  tiltometer.  Such  movement*,  provided 
they  Hre  Btiictlj  equal,  are  not  detrimental,  and 
they  pasBundetected ;  butunequalBeiureaeffect 
a  (^longc  in  level ;  and  any  appreciable  change 
taking  place  along  a  line  joining  the  two  ends  of 
the  buanoe  cose,  is  recorded  and  may  be 
meaaored  by  the  tiltometer. 

The  tiltometer  tube  is  protected  by  surround- 
ing it  with  a  metal  guard,  the  btao  of  which  is  a 
heavy  bissa  ring  B  ;  this  ring  is  prevented  from 


no  direct  Contact.     For  a  series  of  welgbtngi 
we  proceed  as  follows  ;^ 

The  telescope  is  first  brought  oppoaite  tha 
tiltomet«r  and  the  positioa  ot  the  jilumb-Iioo 
determined  ivith  the  aid  ot  the  micrometer. 
Next,  the  teteaoope  is  moved  along  until  the 
ecole  behind  the  pointer  appears  in  the  field  of 
view  ;  the  weighuig  is  then  carried  out  with  oU 
due  precautions.  Lastly,  the  tiltometer  ia 
re-observed :  if  the  former  and  latter  readings 
are  identioal,  and  thoy  rarely  differ  within  so 
short  a  time,  the  data  for  the  weighing  may  be 
accepted  ;  otherwise  the  eiperiment  is  rejected 
and  a  new  one  undertaken.  When  carrying  out 
a  new  weighing  at  a  later  hour  or  on  another 
day,  the  tiltometer  reading  may  be  slightly 
lo^er  or  BmaUer  ;  but  given  an  accurate  know- 
ledge ol  any  such  difference  t,  the  new  weighing 
is  easily  reduced  and  made  strictly  comparable 
with  the  first,  by  the  addition  of   i^i  to   the 


'^' 


aecond  TsJne  obtMoed  for  the  resting  point, 
R.P.,  of  the  beam. 

(7)  The  Tehteopt  and  iit  Carnage.— For 
observing  the  vibrttUons  of  the  pointer,  the  beat 
and  most  convenient  plan  is  probably  that  in 


which  the  telescope  is  mounted  upon  a  firm 
beach  at  a  distance  of  approiimatety  2  metres 
from  the  balance.  In  order  that  t^e  pointer  oa 
well  aa  the  tiltometer  of  the  preceoing  pora- 


the  line  of  vidon  as  shown  in  Fig.  17.  The 
carriage  has  three  supports  ;  two  consist  of  braas 
balls,  which  rest  in  the  groove  :  one  of  those  h 
is  seen  in  the  figure.  The  third  BOpport  is  a 
broad  wheel  w  of  boxwood.  Easy  and  smooth 
movement  is  ensured  by  lubricating  the  groove 
with  tallow.  In  order  that  the  tiltometer 
{vidi  eupra)  may  be  read  with  accuracy,  the 
eyepiece  of  the  telescope  is  fitted  with  a  hori- 
zontal micrometer  u,  graduated  to  0-01  mm- 

(8)  OftheNeiWiitgfor  Faiiguinytlie  Bean.— 
Although  from  the  practical  point  of  view,  a 
balance  beam  may  in  itself  be  perfectly  in- 
flexible, it  is  a9  yet  impoasible  to  so  incorporate 
the  knife  edges  that  they  and  the  beam  shall 
constitute  one  absolutely  rigid  whole.  On 
releasing  a  loaded  beam,  the  consequent  stresses 
bring  about  alight  relative  movements  of  the 
several  knife  edges  and  their  serews.  Snoh 
movements  frequently  aSect,  although  in  minute 
d^ree  only,  the  ratio  of  1i»  lengths  of  tiie 
baJanoe    arms.    The   time    required   for   their 


oompkUon  tuim  not  only  with  tbe  twI&Qw, 
but  also  with  tbe  load,  and  it  maj  luige  from 
few  to  manj  minutes  ;  but,  in  general,  a,  period 
of  from  10  to  16  minutcA  sufficee.  Now,  from 
tbe  above,  it  Aill  be  evident  that  no  weighing 
can  be  of  definite  value,  unleoi  the  knife  edges 
have  already  aasumed  truly  norm&l  ponUons ; 
tad  in  order  that  they  may  do  so,  the  balance 
must  be  fatiffaed.  This  limple  operation 
conaiBta  in  allowing  the  beam  to  vibrate,  for' 
an  appropriate  lima,  after  tbe  pans  have  been 
loaded  aad  the  weighta  adjusted  for  weighing  ; 
the  beam  is  perfectly  fatigued  when  lucceuive 
R.P.  delermiruktioiu  ogroe.  Having  reducvd 
the  balance  to  a  normal  state,  the  actual  weighing 
is  undertaken ;  and  for  this  the  crank  handle 
is  fint  cautiously  tumrd,  bo  that  withont  in 
any  way  relieving  tlia  inttniment  of  its  load,  one 
of  the  ancBtort  is  mom«itarily  and  very  gently 
made  to  lift  its  pan  and  thus  cause  the  be&m  to 
te-oscUlate.    Several  vibratjona  having  pasied 


NCE.  619 

unrecorded,  the  usual  observations  for  the 
determination  of  the  R.  P.  are  earned  out.  The 
above  remark*  conoeming  fatiguing,  are  equally 
applicable  in  the  case  of  an  '  unloaded  '  balance. 
In  Fig.  18  we  have  an  illuitration  typical  in 
character  and  magnitude,  of  initial  nufe-edge 
movements.  Tbe  curve  then  shown,  and  in 
which  Huccesaive  R.Pb.  are  giaphed  against 
coirecponding  time  intervals,  repreaents  tbe 
TMuIta  of  an  eipenment  with  a  highly  inflexible 
buun  of  the  cantilever  form.  Tlw  movements, 
at  first  of  an  oscillatory  nature,  die  away, 
and    finally    the    R.P.    acquires    a    coustaat 

If  for  any  reason  the  loaded  beam  a  arrested, 
the  balance  must  again  be  fatigued  before  a  final 
weighing  is  proceeded  with.  When  it  is  neces- 
sary to  readjust  the  position  of  the  rider  upon 
the  fatigued  beam,  the  operation  may  be  carried 
out  without  detriment,  by  first  slowly  laising 
the  pan  arreston  until  tbey  an  in  mch  a  positim 


m 

m 

m 

^ 

* 

m 

MB 

«  ,._.  .  i 

li 

Jl 

\i 

I 

\t 

4III> 

4ii 

rime  in  seconds  — *■ 


that,  although  they  do  not  support  the  loaded 
pans  and  so  reli         '     ■ 
vibratioika  to  a  Ti 


(9)  Device  for  tnaiMaiiutig  Vnifonuty  in  Us 
Temperatwt  of  the  Beam. — If  a  diOerential 
bolometer  is  ononged  within  a  balance  ease, 
10  that  it*  two  resLstanoe  ooila  are  separated  by 
a  distance  equal,  say,  to  the  length  of  the  beam, 
it  is  easy  to  show  that  small  and  rapid  flnctua 
tions  in  the  temperature  of  tbe  air  are  con- 
tinoally  taking  place,  even  when  the  case  is 
closed.  On  lifting  the  shutter,  the  fluctuations 
become  mots  marked,  and  during  tbe  loading 
of  the  pans  thev  are,  comparatively  speaking, 
quite  violent^  A  pair  of  aenaitive  mcrcury-in- 
slass  thermometers  similarly  placed,  naturally 
tail,  on  account  of  their  sluggishness,  to  indicate 
variations  in  temperature ;  they  show  a  mean 
valne  only.  In  order  that  the  highest  def[ree 
of  precision  may  be  attained,  it  is  imperative 
that  the  temperature  of  the  air  enveloping  the 
beam  should  remain  for  at  least  some  time, 
both  before  and  during  the  proceas  of  weighing, 
ttiicUy  oniform.  The  required  uniformity  may 
be  ensured  by  the  device  iUustrated  in 
Fig.  19. 

As  may  be  seen,  we  have  here,  in  addition 
to  the  usual  balance  case,  a  small  inner  auxiliary 
chamber  which  completely  enctoaes  the  beam. 
Tbe  base  plate  e,  i,  of  this  chamber,  is  of 
aJaminium,  having  a  thickness  of  2  mm.  or 
more ;   it  is  suila^y  slotted  and  perforated  for 


the  passage  of  tbe  pointer  and  books  by  which 
the  pans  are  suspended.  The  ends  ■,  r,  are 
conveniently  made  of  well-seasoned  mahogany, 
having  a  thicknew  of  1  cm.    The  front,  back  and 


Fia.  19. 

also  the  top  of  the  chamber,  are  of  8~I0  mm. 
thick  piste  glass.  The  front  of  the  chamber 
may  be  removed  and .  the  beam  thua  rendered 
occeHsible,  after  dropping  the  holders  h,  k. 
Discs  r,  I,  I,  of  thin  aluminium,  are  fastened  to 
the  pointer  and  pan  hooks  a  little  below  the  base 


520 


BALANCE. 


plate ;  theae  screen  the  apertures  immediately 
above  them.  When  placed  within  tiie  auxiliary 
chamber,  a  differential  bolometer  recording 
variations  as  small  as  jM*  C.  remains  quite 
unaffected,  even  during  the  loading  of  the  pans. 
The  decided  advantage  held  by  the  protected 
over  the  unprotected  beam  is  very  well  shown 
in  Fiff.  20.  The  groups  a,  b  are  the  bolometer 
records  obtained  when,  using  9  weights,  one  of 
the  pans  was  loaded  and  unloaded  six  times  in 
succession.  During  the  experiments,  the  position 
of  the  bolometer  near  the  beam  remained 
unchanged.^ 

(10)  Temperature  Coefficients  of  a  Balance, — 
OthiBr  conditions  being  constant,  the  R.P.  of  a 
beam  will,  in  general,  vary  simultaneously  with 
the  temperature ;  therefore,  unless  the  balance 
is  thermoetaticaUy  controlled,  we  must  know 
with   considerable   exactitude   the   temperature 


coefficient  k  of  the  instrument  The  value  of  h 
will  vary  with  the  balance  and  also  with  its 
load ;  but  for  a  given  balance,  the  several  values 
of  h  for  different  loads  may  be  determined  as 
follows : — 

Clommencing  at  an  early  hour,  when  pre- 
sumably the  temperature  of  the  room  is  at  its 
lowest,  and  with  the  pans  as  the  only  load,  the 
beam  is  released  and  duly  fatigued ;  the  R.P. 
is  then  found  and  the  thermometer  in  close 
proximity  to  the  beam  read.  Using  hot-water 
pipes,  an  electric  radiator,  or  a  gas-fire,  the 
temperature  of  the  room  is  next  raised  by 
about  2^  G. ;  a  litUe  later  the  R.P.  is  re-deter- 
mined and  the  thermometer  within  the  balance 
case  read  a  second  time.  Proceeding  in  this 
way  step  by  step,  a  total  range  of  temperature 
of  some  10°  or  12®  C.  is  covered.  Finally,  the 
room  is  allowed  to  reassnme  its  original  tempera- 


l<k 

}ding. 

t/ntoadmg. 

r 

w 

y  /  L« 

777  unprotected 

• 

\ 

A 

V  V^ 

"^y- 

1.  J 

/ 

\ 

Beam 

protected. 

/ 

w 

0                          4 

4 

I                j 

4 

\  Minuter. 

»a3 


2002 


20-Cf 


20^C. 


Fig.  20. 


tnre,  or  approximately  so,  and  a  last  determina- 
tion of  tne  R.P.  for  this  series  made.  If  the 
first  and  last  members  of  the  series  are  in  agree- 
ment, the  R.P.  values  for  the  higher  tempera- 
tures should  be  reliable.  From  the  data  thus 
obtained,  a  'temperature  coefficient  curve  is 
now  prepared  by  plotting  the  R.P.  values  against 
those  for  the  corresponding  temperatures ;  the 
resultant  graph  enables  us  to  discover  the  true 
R.P.  for  any  temperature  falling  within  the 
experimental  limits  and  for  the  particular  load 
employed.  (In  this  case,  the  so-called  zero 
load.)  Extrapolation  should  never  be  resorted 
to  ;  for  I;  may  at  any  other  temperature  assume 
a  distinctly  different  value ;  its  sign  may  even 
be  reversed :  and  so  ib,  from  being  an  aclditive, 
may  become  a  subtractive  quantity.  Usually, 
it  will  be  sufficient  if  the  temperature  of  the 


*  An  excelleot  plan  Is  to  permanently  set  up  a 
differential  bolometer  In  the  Immediate  vicinity  of  the 
beam;  the  thermometric  condition  of  the  enveloping 
air  oan  then  be  readily  tested  at  any  time. 


beam  is  known  to  0*06*  C.  The  thermometer 
is  placed  horizontally  within  the  auxiliary 
case. 

With  the  completion  of  the  above,  further 
operations  identical  in  kind  are  proceeded  with ; 
and  unless  the  balance  develops  abnormal 
behaviour,  experiments  with  four  additional 
loads  will  suffice.  For  a  200-grm.  balance,  the 
several  loads  may  convenientlv  be  60, 100,  150, 
and  200  grms.  The  results  obtained  with  each 
of  these  loads  are,  as  before,  represented  by 
smoothed  graphs,  all  drawn  upon  one  and  the 
same  sheet.  Often  these  graphs  are  of  the  same 
family ;  with  such  a  group  we  may,  for  the 
given  ranee  of  temperature,  make  use  of  interpo- 
lated values  for  drawing  the  temperatiu^ 
coefficient  curve  corresponding  to  an  inter- 
mediate load.  Finally,  the  whole  series  is 
completed  by  a  re-determination  of  the  R.Pib. 
for  the  unloaded  pans:  the  value  of  all  the 
results  is  thereby  greatly  enhanced. 

Characteristic  curves  for  ib  for  a  200-grm. 
balance  are  reproduced  in  Fig.  21.    The  two 


BALANCE. 


621 


dotted  line  curves  were  derived  from  interpo- 
lated values. 

(11)  The  Suppression  of  Air-streama  about 
the  Pans — ^Increased  accuracy  is  secured  and 
labour  saved,  bv  adopting  some  plan  whereby 
uniformity  in  the  temperature  of  the  air  sur- 
rounding the  pans  is  ensured ;  one  that  in 
practice  has  proved  highly  efScient  is  illustrated 
in  Fig.  22. 

fiach  pan,  together  with  its  stirrup,  is 
enclosed  by  a  fixed  and  massive  brass  cylinder  o, 
having  a  diameter  but  little  ^greater  than  that 


of  the  pan.  The  cylinders  extend  from  the 
floor  of  the  balance  case,  where  they  fit  into 
grooves  in  thick  brass  plates  pp,  to  the  aluminium 
plate  of  the  anxiliaiy  chamber;  and  each  is 
surrounded  by  a  slightly  laiser  cylinder  B, 
which  rests  upon  3  wheels  attached  to  o ;  these 
wheels,  of  which  four  lettered  w  are  shown,  are 
placed  apart  at  an  angle  of  120^  Bv  covering 
that  portion  of  the  fixed  cvlinder  encloeed  by  b 
with  silk,  a  smooth  and  easy  movement  is 
imparted  to  the  latter  when  the  handle  h  is 
pressed  towards  the  right  or  left    To  render 


Temperature  Coefl^cfent  Curves, 

• 

/ 

• 

• 

• 
• 

/ 

/ 

• 

y 

* 
^ 

X 

• 

X 

' 

\ 

€j- 

i 

1 

• 

y 

4/ 

/          / 
/          / 

• 

/ 

/    / 
/    / 
/   / 

• 

y^ 

^ 

II 

/f? 

13 

M 

19 

mx. 

i. 

Fia.  21. 


the  pans  accessible,  lazge  rectangular  apertures 
A  are  cut  in  the  cylinders ;  these  are  opened  or 
closed  by  an  appropriate  rotation  of  b.  In  the 
figure,  the  left-hand  cylinder  is  open  and  the 
other  closed.  The  interior  surfaces  of  the 
cylinders  are  coated  with  a  dead-black  lacquer, 
but  the  exterior  surfaces  are  polished  and  left 
unvarnished.  Now,  theoiy  and  practice  alike 
show  that  with  these  conduitions,  a  temperature 
uniform  in  the  highest  degree,  and  one,  moreover, 
unsusceptible  to  any  but  slow  variations,  is 
quickly  established.  But  given  uniformity 
in  temperature,  it  follows  that  within  a  space  so 
limited  and  confined,  winds  or  air-streams  are 
non-existent;  and  therefore  the  minor  irregu- 
larities ordinarily  arising  from  convection 
currents  about  the  pans,  are  avoided. 

(12)  Concerning  the  Wiping  of  Glass  Vessels, — 
For  glass  vessels  that  are  to  be  weighed  with  any 
degree  of  refinement,  a  most  ceu»ful  wiping  is 
an  indispensable  preliminary;    and  in  malung 


choice  of  material  for  the  purooee,  some  dis- 
crimination must  be  shown.  Theoretical  con- 
siderations verified  by  experiment,  lead  to  the 
conclusion  that  in  all  probability  it  would  be 
difficult  to  discover  anything  superior  or  equal 
to  silk ;  this  substance  possesses  a  very  low 
heat  conductivity  ;  and  during  use  good  speci- 
mens show  a  remarkably  small  tendency  for 
casting  off  loose  filaments.  Objection  is  some- 
times taken  to  the  production  of  electric  chaiges ; 
but  from  the  practical  point  of  view,  the  ground 
upon  which  the  objection  is  based  is  more 
imaginary  than  real 

During  the  process  of  wiping,  direct  contact 
between  the  vessel  and  the  hand  must  be 
scrupulously  avoided;  more  particularly  so  if 
we  desire  to  maintain  oonstancv  of  temperature. 
Some  four  or  even  more  folds  of  silk  should 
intervene  between  the  hand  and  the  vessel ;  and 
if  at  the  same  time  the  hands  are  thickly  gloved, 
so  muoh  the  better.    The  vessel  immediately 


after  it  has  been  wiped,  ihould  be  trtuufeired 

to  the  pan  ot-  the  bsluice  with  the  aid  ol  a 
suitable  lifter.  When  the  tempeiattlre  of  a  globe 
having  a  capacity  of  200  cc.  is  raised  by  ^°  C, 
the  connequent  loss  in  bnoyant^  results  in  an 
apparent  inareaae  of  weight  equal  to  fg  mg. 
A  slightly  warmed  vessel  leassumes  ita  original 
temperature  with  extreme  slowness ;  heooe  the 
desirability  for  guarding  against  any  change  in 
its  temperature. 

(13)  0/ the  Preeavliinu  to  be  laken  in  weighing 
Qlati  Vetselt. — In  weighing  glass  Teasels,  seated 
or   open,   special   difficulties   «  '      * 


These  chiefly  wise  from  (I)  the  variablenna  of 
the  water  skin  upon  tjie  surface ;  (2)  the 
fluctuating  temperature  and  pressure  of  the  air  j 
and  (3)  in  the  case  of  closed  Teasels,  the  in- 
oonstanty  of  volume  rasnlting  from  changca 
in  the  temperature  and  effectiTe  preasnie 
within ;  the  difficulties  are  still  further  accen- 
tuated when  (he  vessel  contains  liquid  matter, 
and  more  pBrticularly  so  when  the  contents  aie 
solid.  For  many  purposes  the  errors  attendant 
upon  cansea  (1)  and  (2)  are  suffioientl^  com- 
pensated by  connterpoiaing  tba  expenmental 
vessels  with  otbera  having  very  similar  volumes ; 


...  .  i  f or  when,  I 
from  the  nature  of  the  investigation,  equality  of 
arta  as  well  as  that  of  Tolume  becomce  a  prime 
necessity.  Now,  although  two  volumes  may, 
by  trial,  be  adjusted  to  almoat  strict  equality,  to 
secure  at  the  same  time  a  similar  equality  ot 
area  is  a  highly  diliicult  problem  t  and  yet, 
unless  coaditlons  are  so  orden>d  that  a  complete 
absence  of  moisture  is  ensured,  a  difference  in 
the  areas  of  a  vessel  and  its  counlerpolBe  may 
well  prove  fatal  to  the  object  in  view.  This 
particular  difficulty  is  surmounted  in  tbe 
following  way  ; — 

A  blower  is  formed  by  fitting  up  a  large  glass 
jar  A,  as  shown  in  the  aelf-eipWatory  Fig.  23. 
A  alow  working  of  the  Buusen  water  pump  p  is 
tU  that  is  required  for  keeping  the  jar  full 
of  air,  the  pressure  of  which  is  governed  by 
the  length  of  the  tube  suppotting  the  bulb  B. 
On    leaving    the    jar   by    way    of   the    tap   1. 


the  air  is  by  means  of  two  further  taps 
divided  into  equal  streams;  each  stream  is 
driven  lirst  through  a  Dreoshel  wash-bottle,  and 
then  through  a  spiral  glass  tube,  both  charged 
with  conoeutrated  sulplioria  acid.  Th«  stream 
on  emergmg  from  the  spiral,  enten  its  own  set 
ot  3  purifying  tubes  ;  the  first  half  of  each  set  i* 
packed  with  small  fragments  of  soda-lime,  and 
the  second  half  with  similar  piece*  of  calcium 
chloride.  Finally,  the  air  is  filtered  through 
glass  wool  or  anbestos,  and  led,  first  throogh 
the  walls  of  the  baJanoe  case,  and  then  through 
the  upper  ends  of  the  cylinders  surrounding 
the  pans.  From  thenoe  either  stream  is 
delivered  through  a  glass  jet  directed  downwarda 
and  placed  centrally  within ■i-.t 


I  ita  cylinder.    With 


described  apparatus,  any  two  obiecta 
[e.g.  a  oloaed  vessel  and  its  counterpoise),  wbcas 


I  to  be  subsequently  compared,  e*a 
be  simultaneously  subjected  to  a  very  perfect 
washing   with   air  freed  from   carboD  dioxide. 


molstare,  snd  dost ;  tfaia  wuhing  U  allowed  to 
proceed  duting  the  f»tigiiing  of  the  beam.  On 
eaoaping  from  the  cyhndere,  the  purified  air 
dispfaceB  the  ordinary  air  of  the  baJaoce  caae ; 
and  as  it  ia  unneceisuy  to  re-open  Uie  shutter 
before  weighing,  the  operation  is  carried  out 
within  an  atmosphere  of  standard  and  easily 
roproducibte  qualitjr.  A  great  cobveaience  is 
secuied  if  the  air  stteama  can  be  arreeted  by  taps 
placed  near  the  balance ;  these  taps  are  closed 
jost  before  the  object  is  weighed.  The  plan 
hece  advocated  haa  met  mth  UTOur  in  several 


Fia.  S3. 

of  the  Oxford  laboratories,  where  it  haa  now 
been  need  for  some  years.  Tbe  method  might 
with  advantage  be  universally  substituted  for 
the  defective  plan  ao  commonly  adopted  with 
chemical  and  physical  balance*.  To  do  tbia 
for  any  balance,  it  is  but  necessary  to  pass  tubea 
delivering  purified  air,  through  the  tep  of  the 
case  juat  above  the  pans  or  in  a  lino  with  the 
extremities  of  the  beam.  The  usual  method  for 
drying  the  air  nithin  a  balance  case  has  several 
■erioua  objcotions,  which  cannot  be  diaciused 

(14)  Dttrrminalioji  of  the  Presmre  Co- 
(.iftcientoo/OIaMOIo&ef.— -When  oloaed  vessels  ace 
weighed  under  different  pressures,  it  is  important 
that  the  vessel  and  its  counterpoisB  poesew  not 
only  similarity  of  lorm  and  volume,  but  also 


I   imperfect   and   vary 


iritli    the 


Fio.  24. 


globular  veBseU  may  be  compared  ai 
measured  with  the  aid 
of  the  apponitus  indi- 
cated in  Tig.  24.  The 
taps  having  been  tem- 
porarily removed,  cither 
globe  is  introduced  into 
the  bell  jar  i,  and  its 
neck  passed  up  throagh 
an  airtight  cork  secure-  ij 
ly  fixed  in  the  mouth  of /j 
the  jar;  a  glass  tap, [4 
connected  with  a  aealed  ^ 
mercury  manometer  ra, 
is  then  fused  at  d  to 
tbe  neck  of  the  globe, 
and  the  open  end  of  the 
jar  closed  by  a  stout 
brass  plate  Pi  the  plate 
may  be  attached  »ith 
Faraday  cement  or 
marine  glua,  i>otb  of 
which  are  insoluble  in 
water  and  readily  soften 
with  heat.  Next, 
through  a  hole  in  (he 
cork  made  foe  the  reception  of  the  tube  T,  air- 
free  water  is  introduced  until  the  jar  is  com- 
pletely filled  ;  the  tube  t,  also  filled  witl:  water, 
IB  then  placed  tn  litu,  and  its  fine  capillary  jet 
kept  immersed  in  water  as  shown. 

In  measuring  the  pressure  coelficient.  a 
small  weighed  bottle  is  first  substituted  for  that 
usually  kept  beneath  the  jet;  air  is  then  forced 
into  the  globe  until  the  desired  pressure  is 
iiKlicated  by  the  manometer  j  as  the  pressoie 
distends  tbe  globe,  water  iaejeoted  into  the  bottle; 
this  ia  weighed  and  the  expansion  resulting  from 
the  pressure  calculated.  II  a  series  of  preastires 
be  applied,  their  values  may  subsequently  be 

Stted  against  tbe  corresponding  expansions ; 
m'  the  gnph  thus  obtained  eipanaiona  foe 
other  pressures  are  readily  determined.  With 
slight  and  obvious  modifications  contraction 
coefSoients  may  also  be  measured. 

(16).  Of  tU  Appartni  Change  in  lit  Weight 
of  a  Cooling  Body. — When  it  is  necessary  to  heat 
a  body  before  ita  weight  is  determined,  ample 
time  must  tie  allowed  lor  the  subsequent  cooling. 
The  time  required  for  a  hot  body  to  assume  the 
temperature  of  the  balance  case  is  great«r  than 
one  would  in  general  suppose.  The  importance 
of  delaying  tbe  weighing  until  tbe  object  baa 
acquired  the  temperature  of  the  surrounding 
air  ia  admirably  illuatrated  in  the  following 
Fig.  20. 

The  data  for  the  above  graph  was  obtained 
as  follows :  A  No.  00  B.P.  crucible  was  beated 
to  bright  redness  for  some  time  and  then  re- 
moved from  the  flame.  When  the  cmcible  was 
no  longer  vieibti/  hot,  it  was  placed  upon  the 
balance  and  immediately  weighed  under  ordinary 
conditions ;  this  weighing  was  followed  by 
others  at  convenient  interval?  until  9  weighings 
in  all  had  been  carried  out  During  the  perimi 
of  half  an  hour  required  for  tbe  experiment,  the 
weight  of  the  crucible  was  constantly  growing, 
at  first  rapidly,  and  then  slowly  ;   and  notwiUi- 


524 


BALANCE. 


standing  the  smaUneat  of  the  mass,  ita  limited 
surface  and  the  free  coolinff  in  air,  Uie  apparent 
weight  of  the  crucible  had  not  attained  a 
maximum  yalue  when  the  experiment  was 
terminated.  The  observed  ohaoges  in  the 
apparent  weight  result  from  a  summation  of 
Tarious  e£Fectfl  of  which  the  following  appear  to 
be  the  chief. 

1.  An  apparent  inereage  in  weight  due  to  (a) 
the  gradual  re-condensation  of  moisture  upon 
the  glazed  surface ;  (/9)  a  slight  Increase  in  the 


length    of    the    arm    supporting    the    object 

r;  (7)  the  re-absorption  of  air  and  moisture 
^  the  porous  mass  of  the  crucible;  and 
(8)  the  lessened  buoyancy  of  tiie  heated  air 
immediately  enveloping  the  crucible  and  babmce 
pan. 

2.  An  apparent  decreaae  in  weight  due  to 
ascending  convection  currents  which  tend  to 
lift  the  object  pan. 

The  lengthening  of  the  balance  arm  noted  in 
1  (/9)  is  effected  by  the  heated  air  rising  from  the 


Xnoff^' 

% 

^ 

20,  /^ 

- — 



/ 

IS. 

• 

/ 

10, 

fxper. 

Jan.3i 

0OB.P.crL 

db/e. 

/ 

5. 

a 

/ 

Or 

• 

S' 


w 


/5' 

Fig.  25. 


20' 


25' 


30 


cooling  crucible.  The  re-absoiption  of  air  and 
moisture  (1,  (3))  by  the  general  mass  of  the 
porcelain  was  rendered  possible  by  the  entire 
absence  of  glaze  upon  the  bottom  of  the  crucible. 
When  the  crucible  is  completely  glazed,  the 
internal  condition  of  the  porcelain  remains 
presumably  for  all  practical  purposes,  strictly 
constant. 

(16)  Concerning  Ordinary  Balance  Cases, — 
(a)  With  few  exceptions  the  top  of  the  usual 
balance  case  consists  of  a  sunk  glass  panel  a,  6 
(Fig.  26) ;  this  is  a  constructioxial  defect  which 
we  remedy  in  the  following  way.  A  strip  of 
velvet  p  about  an  inch  wide  is  fastened  by  means 
of  thin  glus  or  seocotine  along  the  four  sides  and 


near  the  edges  of  the  top  of  the  balance  ease, 
as  shown  in  the  accompanying  Fig.  26. 

When  the  glue  has  naidened,  but  not  before, 
a  piece  of  plate  glass  ab,  su£ScienUy  large  to 
just  overlap  the  rectangle  is  placed  upon  the 
velvet.  The  velvet  surface  not  only  grips  the  glass 
and  thus  prevents  it  from  being  readUy  distuned^ 
but  also  acts'  as  a  highly  efficient  filter  and  so 
prevents  dust  from  penetrating  to  the  ordinaiy 
panel  within.  The  added  pand  is  easily  dusted, 
and  during  the  cleaning  we  do  not  aa  before 
incur  the  risk  of  forcing  dust  between  the  glass 
and  the  supporting  surfaces  and  so  to  the 
interior  of  the  balance  case. 

{fi)  The  case  of  a  pxedaioa  balance  should 


be  opeoed  or  clomd  by  lUdiiiB  rathsr  thui  by 
hinged  doois.  When  %  hinged  door  i*  opened 
(he  preeaure  of  the  air  within  the  caae  is 
momeDtArily  lowered ;  in  oonoequenoe  of  thii, 
the  eitemal  tur  nuhe«  thioogh  the  innomenble 
crevices  in  the  framework,  uid  aweepiog  before 
it  the  eistwhile  quieecent  dost,  ohai^ce  the  spMce 
wittiin  with  flouting  partiales.  Thu  fact  may 
be  Terified  by  oonduoting  »n  eiperiment  in 
bright  sunlight ;  on  opening  the  door  the  mn- 
beuna  At  onoe  rereal  toe  inroming  diut. 


ordinary    window    Bsshee.     Shutter*    that    i 
anrated  by  olatchee  are  highly  objectionable. 
Daring  the  working  of   a  clutch  vibrations  arc 
aet  up,  and  thaw  are  communioated  tothe  balance 
with  delrimental  eSecta. 

(IT)  Oftht  DiStreni  Mtthodt  oj  Wtighing.— 
An  article  on  weighing  i»  incomplete  unleaa  it 
contains  some  alloaioD  to  the  several  methods 
available  for  accurate  work ;  but  thoee  methods 
an  so  well  known  both  in  theory  and  praotioe 
that  die  briefest  outline  will  here  suEGce.  To 
b^in  with,  we  take  it  as  gmjited  that  an 
experimanter  seeking  for  high  precidon  would 
noe  the  method  of  vibrations  for  ascertaining  the 
R.P.  of  his  balance ;  in  the  preceding  article 
this  matter  has  been  dealt  with  by  the  lato 
Prof.  Dittmar  ;  and,  therefore,  further  oommeDt 


obemistB  and  physicists  for  much  of  their  work, 
there  remain  (1)  the  method  of  Borda,  and  (2) 
that  introduced  by  Gansa. 

(1)  In  Bordas  method  the  object  to  b« 
weighed  is  placed  in  either  pan,  and  then 
accurately  counterpoised  by  any  convenient 
nnknown  mMM«i  such  masses  may  consist  of 
indifierent  brass  weights,  lead  shots,  fine  sand, 
he.  When  the  adjostment  is  complete,  standard 
masecs  are  sabsUtnted  for  the  objeot,  and  these 
are  varied  until  equilibrium  has  been  re-estab- 
lished. Given  nncbangin^  conditions,  it  is 
obrioDS  that  the  total  weight  of  the  standard 


tiona:  (■),  its  tediousnees  and  IS)  the  impossi- 
biU^  of  adjusting  two  initially  different  magni- 
todea  to  pnate  equality.  These  objections  are 
so  weighty  that  Bordas  method  is,  compara- 
tively spMkins,  bnt  seldom  used. 

(2)  Following  Ganss  and  nsin^  the  method 
ol  vibrations,  the  R.P.  is  found  wttb  ths  object 


fint  in  mm  pan  and  then  in  the  other ;  two 
determinations,  d,,  d,,  of  the  R.P.  are  thus 
obtained.  Then  if  S  be  the  sensibility  of  the 
balance  in  mg.,  the  diffenttee  D  between  tlw 
weight  of  the  standard  mass  employed  and  that 
of  the  object  is  given  by  the  equatiiai 

and  the  apparent  weight  of  the  body  is  thus 
determined.  The  superiority  oE  this  method 
over  others  is  based  uptm  a  principle  well 
tmderstood  by  physicists,  that  in  general  ii' 
""'^ir  to  determine  wj*^  -ftrt«i.artT.  Kh  w^nf  m 
magnitudes  difli 
value  of  either. 
For  some  further  information  upon  the  very 
important  subject  at  highly  t«£aed  weighing, 
thereadermay  ite  referred  to  {!] '  The  Limitations 
of  the  Balance,'  B.  Blount,  Chem.  Soc.  Trans. 
iglT,  voL  iu.  1036 ;  (2)  '  Vacunm  Balance  Cases,' 
Blount  and  Woodcock,  Chem.  8oa.  Trans.  191B, 
vol.  cxiiL81;(3)'ObservatloiuontheAnomaioua 
Behaviour  ol  DeUoate  Balanoea,'  Manley,  PhiL 
Trans.  Series  A,  vol.  eoz.  387-415 ;  (4)  '  On  the 
Apparent  Change  in  Weight  during  Chemical 
Reaction,' Hanley,  PhiL  Trans.  SerieaA,  vol  ecxii. 
227-260;  (6)  'Obaerved  Variations  in  the 
Temperature  Coefficients  of  a  Precision  Balance,' 
Mauley,  Pror.  Roy.  Soc.  A,  voL  Ixiivi.  091-600; 
and  (8) 'Dependence  of  Gravity  on  Temperator*,' 
Southenis,  Proa.  Roy.  Soc.  A,  vol.  IzxviiL 
393.  As  the  above  third-named  paper  contains 
referenoee  to  other  papers  bearing  upon  the 
same  subject.  It  is  nnneoeeiary  to  repeat  them 

In  concluding  this  particular  bi«noh  of  an 
interesting  inbjeot,  we  may  state  that  by 
availing  onr«elvea  of  all  precautions  at  present 
known  to  us,  it  has  been  found  possible  to  attain 
the  Bconraoy  of  ±  t  in  2  X  10*  or- thereabonta, 

MieroJxUa»ft». — For  thi  accurate  determina- 
tion of  extremely  small  masses,  instnunents 
known  as  micro- E>ala7ice<  are  used.  These  are  of 
two  types  ;  the  action  of  the  one  depends  upon 
toraion,  and  that  of  the  other  upon  gravity  ; 
bnt  of  the  two  the  latter  has  been  the  more 
successfully  and  highly  developed.  Nemst  and 
Rieaenfeld  (Ber.  1903,  30.  2066)  dewribed  a 
tonion  balanoe  aensitive  to  0-0005  mg.  wit& 
a  load  of  several  milligrams  (for  applications  of 
same,  v.  Jtnecke,  Zeitech.  anaL  (]hem.  1904, 
43,  547  ;  Brill,  Ber.  I90S,  3B,  140 ;  Brill  and 
Evans,  Chem.  Soc.  Trans.  1908,  93,  1442).  The 
lero    of    this   balance   is   inconstant,   and    ila 


Grant  (Froc.  Roy.  Soc.  1900,  A.  82,  SSO),  and 
modified  by  Gray  and  Ramsay  (fbid.  1911,  A. 
M,  630 ;  1912,  A.  86,  270),  to  carry  loads  ranging 
from  1  or  2  mg.  to  1  decigram  with  a  anisi- 
tjveneu  of  I  x  10-^  to  4  x  lO-'  grm.  The  lero* 
of  these  balances  remun  constant  over  long 
periods  of  time. 

The  beam,  consisting  of  thin  dllca  rods  fused 
together  to  fonn  a  framework  as  shown  in  Fig.  27, 
has  a  length  of  10  cms.  (io  Pig.  28  (n)  a  besm 
having  a  more  rigid  type  it  repre«ent«d).     The 


quarts  knife  edge  reets  upcn  a  highly  polished 
and  truly  plane  quarts  surface  secured  V>  the 
top  of  the  brdss  pillar  > 


The  vibntiona  ol  the  bsUnce  are  observed  , 
by  means  of  a  beam  of  light  intiodnoed  through 
the  window  c  and  reflected  b;  a  tinj  platdnised 
quartz  mirror  fiued  to  the  beam  at  o ;  with  the 
milTor  in  this  pomtion,  ita  angular  movements 
are  not  accompanied  by  appreciable  ones  of  a 
translational  kind.  The  rcfleoted  light  fallanpon 
a  vertical  mm.  scale  placed  at  some  convenient 
distance  from  the  mirror.  The  thtee-way  tap  ■ 
allows  the  interior  of  the  balance  com  to  b« 
put  into  communication  with  either  the  atmo- 
sphere  or  a  vaocum  pump ;  the  manometer  F 
recordB  the  prefflure  withm  the  case.  A  fine 
quarts  thread  fused  to  the  beam  at  o  support* 
fl.)  a  quartz  bulb  fi  of  known  volume  V  c.c, 
{either  iilled  with  but  or  vacuous),  (ii.)  the  scale- 
pan  J,  and  (iii.)  a  quatti  coonterpoige  k.  The 
whole  bancs  within  tht  tube  l  (fitted  b>  the 
case  by  toe  eroundslass  joint  h),  and  is 
counterpbi'ed  by  a  »obd  bead  of  lUica  fused  to 
the  beam  at  k.  A  little  uraninm  oxide  inside 
the  case  ionises  (he  air  and  eliminates  disturb- 
ing electrical  eflecte;  and  cal  ium  chloride  in 
L  keepa  the  interior  dry. 


Fio.  27- 
To  perform  a  wwghing,  the  preasure  in  the 
cue  is  suitably  lowered  (to  P,  at  temp.  Tj  aba.), 
and  the  position  of  the  reflected  spot  of  light  on 
the  scale  Uken  as  the  lero.  The  substanoe  is 
then  placed  on  the  pan  j,  and  a  nowpreasure 
(P,  at  temp.  T.aba.)  determioed  under  which  the 
wro  of  the  balance  is  reoovered.  The  weight  of 
the  suhatonoe  is  then  given  by  the  espreasion 
(,,-wt.  of  1  0.0-  air  at  N.T.P.) 
873Vg,/-Pi 


760 


\T,    T,7 


The  usual  vacuum  correctiou  is.  of  on 
neoessary.  Only  weights  less  than  the  weight 
of  alz  that  the  bulb  a  oau  hold  may  be  thus 
determined.  To  meaanro  greater  weights,  the 
oountorpoise  K  is  replaced  by  a  lighter  one ;  a 
Mries  of  such  counterpoises  is  required,  and  the 
diSerenoes  between  their  weighta  may  "^ 
measured  on  the  micro-balance  iteelf.  Tt  isc 
venient  to  malie  the  bead  n  counterpoise  the 
bulb,  Ecale  pan,  and  a  set  of  weights  (Fig.  28  (£)) 
(langing  from  2  to  O'l  mgm.  and  made  from 
capiDary  quartz  tubing  :  these  are  cahbrated  on 
the  balance).  In  weighing  a  enbstance,  weiihts 
are  removed  to  obtain  acoaise  adjustment:  the 


pieisure  within  the  case  is  then  idtered,  thereby 

making  the  (variable)  buoyancy  of  the  air  on  ^e 


Fio.  28. 

accuracy   of  the   weighings   is   limited  to   the 
acy   with   which  V   may   be  determined ; 


the  beam,  < 


lighed  0-t 


the  bulb  a 
cc!  and  contained 
the  baliinoe  had  a 
was    sennvitive   to 


Bighe< 
had  a  capacity  of  0- 
6-MxlO-'  grma 
period    of    ^  B 
4  X 10-'  arm. 

The  mioro-balani^  of  Gray  and  Ramsay  haa 
been  modified  by  Hans  Petteraaon  (Goteborgx, 
Vet.  Vitterh.  Samt.  19U,  14th  series,  ivi ). 
In  the  altered  form  the  oentnl  knite  edges  are 
dispensed  with,  and  the  beam  suspended,  as 
shown   in   Fig.   29,  by  two  thin  quartz  fibres. 


which  are  highly  atUtnuated  at  their  points  of 

junction  with  tne   horizontal   rod.    Petttrsson 

also  greatly  improved  the  balance  case ;   and 

for  a  vacuum-tight  cement  he   uses  an  alloy 

having     a     low    fosing -point.      Further,    the 

beam    arrestment    is    magnetically    controlled 

tlirough    the    top   of    the    balance    caee ;    in 

this     wav,    certain     sources     of     eiror,     doe 

to     possible    air    leakage,    are     avmded^      R. 

Stromberg    (Aonalen,   der     Phy- 

sik.  1916,  47,  039),  haa  improved  c 

thePettetason  balance,  and  at  the 

same  time  increased  its  sensibility  ^^^= 

by  the  substitution  of  detacliable 

forfiiedthreada.     Theformot  the 

StiSmberg   suspension    is    shown 

in    Fig.   30,   and    the    complete      FlO.  30. 

Pettersaon-Stromberg    beam    and 

its  accessories   in  Kg.  31.      To   the  axial  rod 

of   the   balance  are   attached  (1)  a  Wny  screw 


r,  toi  adjusting  Ihe  centre  of  grevitf ,  and  (2)  ( 


^ 


.inate  plane  mirror  m,  for  indimting  with  the 
d  ot  nSected  light  the  angular  position  of  the 


NCE.  BS7 

y>eam.  A  section  of  the  complete  balance  ia 
ahown  in  Fig.  32.  An  instrument  of  thu  type 
when  ourying  ita  maximum  toad  of  GO  mg., 
may  appamnUy  have  a  aenaibility  as  high  as 
-01  ^-mgrm.  (1  x  10-~ii  grm-}.  The  Fettersaon- 
StiOmb^  balance  has  Iwen  osed  for  tMting  the 
validity  of  Pajynting'B  Uw  at  high  temperataree, 
for  measuring  the  volatility  of  silica  at  M0°  C, 
and  also  for  the  aoouiato  determination  of  the 
diamsgnetio  oonstanta  of  gaseous  hydn^en  and 
nitrogen. 

A  simple  form  of  mioro-balaaoe  for  determin- 
ing the  density  of  a  gas  has  been  described  bv 
P.  W.  Aston  (Proo.  Roy.  8oo.  1914,  A.  89,  43DJ. 
The  balance,  tvhich  is  made  entirely  of  quartz, 
is  represented  in  Fig.  33.  Tbe  beam  oonaiata  of 
tno  thin  rods  fused  together  aa  shown  ;  tho 
lower  end  of  the  shorter  rod,  t,  terminates  in  a 
knife  edge  which  rests  upon  a  quarti  plane. 
To  one  end  of  the  beam  ia  fused  a  bulb  b,  having 
a  capacity  of  about  0*3  c.c,  and  to  the  other  the 
oonnterpoiaing  rod  r.  The  case,  made  of  rect- 
angular piece*  of  pUte  glass,  is  as  dimiuative  aa 
cironmstaooea  permit ;  the  cell  containing  tbe 
beam  ia  not  mora  than  3  mm.  wide,  and  its 
voltune  is  a  tew  cc.  only.  A  speoial  chamber  t, 
which  is  cemented  to  the  left  end  of  the  case, 
ia  oloaed  by  the  stopper  «,  which  is  pushed  in 
nntil  it  just  fails  to  touch  the  contamed  bnlb. 
One  limb  of  a  T-tube  having  a  capillary  bore, 
gives  acoeas  to  the  interior  of  the  balance  case ; 
the  second  limb  i»  fused  to  a  mercncy  manometer, 
and  the  third  to  a  S-way  tap.  By  means  of 
this  tap  communication    between  the  balance 


530 


BALATA. 


^tiapercha  oontaininf  a  similar  amonnt  of  resin, 
it  is  found  to  be  a  little  softer  and  more  flexible. 


The  composition  of  Balata  is  shown  by  the 
following  typical  analyses : — 


DescrtptloB. 


Specially  prepared  sheet  * 
Block  balata  ^ 
Commercial  specimens  * ' 
Balata*  •     •         .         . 


Sonree. 


British  Qniaaa 

VeneoEneU 

Mostly  British  Gniana 

Datch  Qniana 


Moisture 
per  oeat* 


GiitU 

per 

eent. 


1-9 

1-8 

13-8 

6-3 


49-7 
45-7 
41-5 
43*5 


Besln 

per 

cent. 


44-0 
44-2 
34-8 
36-9 


Protddi   Dirt 


per 
oeot. 


3*8 
3*0 


per 
cent. 


nfl 
5-3 
9*9 
14*3 


Anh 

per 

cent. 


0-6 
[1-28] 


The  gutta  of  balata  is  very  tenacious  and  of 
excellent  miality;  it  is  insoluble  in  alooho!, 
acetone,  ether,  or  cold  petroleum  spirit,  but  is 
readily  dissolved  by  cmoroform,  carbon  disul- 
phide^  or  boilinc  petroleum  spirit  The  resins 
present  are  similar  to  those  of  guitapercha,  and 
consist  of  (1)  a  white  crvstalUne  resin  UiAane) 
soluble  in  hot  but  insoluble  in  cold  alcohol; 
and  (2)  an  amorphous  yellow  resin  ifiuamU) 
soluble  in  cold  alcohoL  An  examination  of  the 
total  resin  of  balata  by  Obach  showed  that  it 
oonnsted  of  about  2  parts  of  albane  to  3  parts  of 
fluayile. 

Balata  is  utilised  commercially  as  a  substitute 
for  guttapercha.  Its  chief  appuoations  are  for 
the  manufacture  of  belUng,  in  which  the  balata 
is  interposed  between  layers  of  canvas;  for 
insulating  purposes;  and  for  the  manufacture 
of  the  covers  of  golf  balls,  after  the  removal 
of  the  greater  part  of  the  resin  by  solvents.  It  is 
also  employed  to  a  considerable  extent  for  mixing 
with  rubber,  and  for  numerous  minor  purposes. 

The  bulk  of  the  commeroiid  supphes  of 
balata  are  obtained  from  British  and  Dutch 
Guiana  and  Venezuela.  Cf.  Ter  Lasg,  Caout.  et 
Guttapercha,  1915,  12,  8619.  H.  B. 

BALLISTITE  v.  Ezplosivxs. 

BALLOON  or  FLEXIBLE  VARNISH  v. 
Vabkish. 

BALL  SODA  v.  Soda  maitufaoturb,  art 
Sodium. 

BALM  OF  COPAIBA  v.  Oleobbsins. 

BALM  OF  OILEAD.  Mecca  or  Opobalsam 
(v.  OLso-Basiirs). 

BALSAMS.  The  exudations  of  plants, 
whether  spontaneous  or  promoted  by  incisions 
made  in  tneir  stems  or  roots,  consist  chiefly  of 
resin,  gum,  volatile  oil,  and  certain  aromatic 
acids,  or  mixtures  of  these.  The  resins  are 
characterised  by  insolubility  in  water  and 
solubility  in  alcohol,  the  gums  by  solubility 
in  water  and  insolubility  in  alcohol,  and 
both  by  not  beins  volatile  without  decom- 
position. In  certam  exudations  the  resin  is 
dissolved  in  volatile  oil,  forming  the  class  of 
oUo-resins  of  which  the  so-called  Canada  balsam 
is  an  instance.  Gum  arable  is  a  familiar  in- 
stance of  a  gum  obtained  direct  from  the  plant ; 
mastic  is  an  instance  of  a  resin.  The  cwss  of 
gum-resins  may  be  represented  by  myrrh. 

Now,  amongst  these  resins  and  oleo-resins 
there  ii  a  group  the  members  of  which  are  marked 
by  possessing  a  peculiar  fragrant  odour  and 
agreeable  pungent  taste,  which  is  due  to  the 
presence  of  free  or  combined  cinnamic  or  ben- 

1  Analysed  at  Imperial  Institute. 
>  Analysed  by  Br.  Obaoh. 

•  Average   flgurea   for   nineteen   commercial   lota 
representing  50  tons. 


zoic  acid.  These  are  the  balsams^  and  it  Is 
convenient  to  consider  them  as  a  class  by  them- 
selves. The  word  '  balsam,'  it  is  true,  has  some- 
times been  used  in  a  wider  sense — ^indeed,  it  was 
originally  employed  for  an  oleo-resin  resem- 
bling the  so-called  Canada  balsam ;  but  it  is 
more  convenient  to  restrict  the  term  to  resins  or 
oleo-resins  which  contain  cinnamic  or  benzoic 
acid.  The  balsams  have  long  been  familiar  to 
writers  on  materia  medica,  some  of  them  being 
known  to  Plinv,  and  even  earlier  to  the  Greek 
physicians.  They  are  favourite  constituents  of 
the  incense  used  in  the  Greek  and  Roman 
churches,  and  while  they  cannot  be  said  to  have 
an  important  therapeutic  value,  they  are  reputed 
mild  tonics  and  stimulants  aiid  are  a  common 
flavouring  agent  in  expectorant  medicines.  The 
following  are  the  more  important : — 

Benzoin.  Oum  Benjamin;  Benzointim, 
B.P.,  U.8.P.  {BeruBoin,  Fr. ;  Benzoiharz,  Ger.). 
The  benzoin  of  Java  and  Sumatra  is  derived 
from  the  thick-stemmed  trees  of  Styrax  BemoHn 
(Dryander,  PhiL  Trans.  1787,  303;  BenU.  a. 
Trim.  169),  while  the  more  l^ghly  prized  8iam 
benzoin  is  probably  obtained,  according  to 
Royle,  from  the  Styrax  Finlaysoniana  (Wall). 
The  souree  of  Siam  benzoin  is,  however,  still 
uncertain  (Holmes,  Pharm.  J.  [3]  14,  354).  The 
first  European  writer  to  mention  benzoin  is 
Batuta,  who  travelled  in  the  East  early  in  the 
fourteenth  century,  and  from  that  time  to  the 
present  day  the  drug  has  been  an  established 
article  of  materia  medica.  It  is  largely  used  for 
incense  and  in  the  preparation  of  fumigating 
pastilles,  and  enters  into  the  well-known  Friarr 
Balsam  or  compound  tincture  of  benzcdn,  a 
favourite  dressing  for  wounds. 

'The  juice  exudes'from  the  trees  as  the  result 
of  incisions,  and  it  is  allowed  to  harden  before 
it  is  removed.  During  the  firet  three  years 
of  the  life  of  a  tree  the  oalsam  dries  in  the  form 
of  tears,  Tlus  is  called  head  benzoin,  and  is 
the  most  highly  reputed.  A  less  esteemed 
variety  is  obtained  during  the  following  seven  or 
eiffht  years,  which  is  browner  in  colour  and  is 
ccSled  b^My  benzoin.  Lastly,  the  trees  are  split, 
and  the  commoner  foot  bexLzoIn  is  scraped  off 
(r/.  Fliick.  a.  Hanb.  405). 

Benzoin  is  obtained  as  a  hard  brittle  mass, 
consisting  essentially  of  a  mixture  of  resins 
together  with  uncombined  benzoic  and  some- 
times cinnamic  acids.  The  resins  are  entirely 
soluble  in  solution  of  potash  and  in  alcohol,  but 
by  their  behaviour  toward  other  solvents  they 
have  been  distinguished  as  a-resin,  $-resin,  ki» 
(Unverdorben,  Pogg.  Ann.  8,  W7 ;  Kopp, 
Compt  rend.  19, 1269 ;  Van  der  Vliet,  Annakii, 
34,  177).  The  yield  of  bentoic  add  varies  from 
12  to  20  p.c,  being  on  an  average  about  14  p.c. 


BALSAMS. 


S31 


To  extract  it  (1)  the  benzoin  may  be  mixed  with 
sand  and  heated  in  a  snitable  yessel,  over  which 
is  placed  a  receiver  to  collect  the  vapours  of 
benzoic  add,  which  condense  in  beautunl  tufts 
of  acicular  crystals :  or  (2)  the  benzoin  may  be 
boiled  with  milk  of  lime^  filtered,  and  after 
concentration  of  the  calcium  benzoate  solution 
thus  obtained,  the  benzoic  acid  precipitated  by 
hydrochloric  acid :  or  (3)  the  free  benzoic  acid 
may  be  extracted  by  treating  the  powdered 
resin  with  warm  carbon  duulphide.  Ludy 
(Arch.  PharuL  231,  43)  has  shown  that  the 
a-,  fi;  «md  y-  resins  of  the  earlier  investigators 
are  mixtures  of  the  partially  hydrolysed  cinna- 
matee  of  the  resin  alcohols  present,  the  a-resin 
being  the  least  and  the  y-  the  most  hydrolysed. 
He  also  finds  that  benzoin  from  Sumatra  con- 
tains bemaie  acid,  gtjfrene,  traces  of  betuxUdehffde 
and  benzene,  I  p.c.  of  vanillin,  1  p.o.  of  phenyl- 
propyl  dnnamate,  2-3  p.c.  of  einnamyl  dnnamate, 
and  a  mixture  of  a  little  benzoresifud  einnafnate 
with  much  reainotannol  dnnamate,  this  mixture 
fOrmine  the  main  constituent  of  the  balsam. 
In  addition,  woody  impurities  occur  to  the 
extent  of  14--17  p.c,  also  free  dnnamie  add,  but 
to  a  less  extent  than  free  benzoic  add.  By 
hydrolysis  of  the  mixture  of  benzoresinol  and 
resinotannol  dnnamates  the  two  alcohols  are 
obtained,  hefuorednoi  OicHggOs,  consisting  of 
white  c^stals,  and  rednokinnol  GisHsqOa, 
a  brown  amorphous  powder. 

Siamese  benzoin  also  examined  by  Liidy 
(Arch.  Pharm.  231,  461)  differs  from  Sumatra 
benzoin  by  containing  no  oinnamic  acid  either 
free  or' combined,  the  main  constituent  being  a 
mixture  of  a  little  benzoresinol  benzoate  with 
much  siarednolannol  hemoate*  The  total  amount 
of  benzoic  add  from  both  esters  was  38*2  p.c. 
The  alcohols  obtained  by  the  hydrolysis  of  the 
resin  are  present  in  the  proportion  of  about  1:11. 
The  benzoresinol  is  identical  with  that  obtained 
from  Sumatra  benzoin  and  ciystallises  in  white 
prisms;  m.p.  272^  Siarednolannol  Ci^Hifim 
is  a  brown  powder  very  similar  to  resinotannol 
obtained  from  benzoin  of  Sumatra.  To  dis- 
tinguish between  Sumatra  and  Siam  benzoin, 
0*5  grm.  is  slowly  heated  to  40**  G.  with  10  c.o. 

SotMsium    permanganate    solution,  when    the 
umatra  variety  gives  the  odour  of  benzaldehyde 
(U.S.P.). 

Benzoin,  with  the  exception  of  woody  frag- 
ments always  present  in  the  cake  variety,  should 
dissolve  in  five  times  its  weight  of  alcohol,  and 
this  solution  should  give  wi£h  water  a  milky 
emulsion  having  an  add  reaction ;  not  less  than 
75  p.c.  of  Sumatra  and  00  p.c.  of  Siam  benzoin 
should  be  soluble  in  alcohoL  Adulteration  with 
resin  may  be  detected  by  warming  with 
petroleum  benzine  or  carbon  disulphide,  wash- 
ing the  benzin  solution  with  sodium  bicarbonate 
and  then  with  water,  and  finally  shaking  with 
copper  acetate  solution :  a  green  colour  indicates 
the  presence  of  resin. 

PeriL  Balsamum  Peruvianum,  B.P. ; 
U.S.P.  {Baume  de  Pirou,  Fr. ;  Perubaleam, 
Ger.) 

A  dark  molasses-like  liquid  obtaiaed  in  the 
State  of  Salvador  in  Central  America  from  trees 
of  MyroxyUm  Pereira  (Klotzsch).  I>escription, 
V,  BentL  a.  Trim.  83.  Balsam  of  Peru  was  pro- 
bably introduced  into  Europe  soon  after  the 
'  Spanish  conquest  of  Guatemala  in  1624  (Fluck.  a. 


Hanb.  206).  The  bark  is  bruised  and  scorched 
late  in  the  autumn,  and  the  exudation  ezdted 
by  this  means  is  collected  (Fluck.  a.  Hanb.  2p7  ; 
Dorat,  Amer.  J.  Pharm.  [3]  8,  302 ;  Hanbury, 
Pharm.  J.  [3]  6,  241,  316). 

Balsam  of  Pern  sinks  in  water,  in  which  it 
is  insoluble.  It  has  a  sp.gr.  of  1*140  to  1-168 
(M30-M60  at  26%  U.S.P.).  It  is  soluble  in 
absolute  alcohol,  chloroform,  acetone,  and  glacial 
acetic  add.  Examined  by  Kraut  (Annalen,  162, 
129)  and  Kachler  (Ber.  2,  612),  the  chief  con- 
stituent  of  Pern  balsam  was  supposed  to  be 
dnnam^n,  benzyl  dnnamate 

C,H,CH :  CJHCOOCtHt 

Kachler*s  analysis  of  Peru  balsam  is : — cinnamic 
acid  46  p.c,  benzyl  alcohol  20  p.c,  resin  32  p.c 
Cf.  Attfield  (J.  1863,  667);  Delafontaine  (Z. 
1869, 166)  finds  in  addition  to  benzyl  dnnamate, 
dnnamyl  dnnamate  or  tiyradn,  Trog.  (Arch. 
Pharm.  232,  70)  by  suitable  treatment  has 
divided  Peru  balsam  into  two  constituents,  an 
oil  and  a  redn.  The  liquid  portion,  known  as 
oinnamein  to  the  earlier  investigators,  consists 
of  benzyl  benzoate  with  a  small  quantity  of 
benzyl  cinnamate  and  forms  from  6o  to  60  p.c. 
of  the  balsam ;  cinnamic  acid  and  vanillin  are 
present  in  very  small  proportions.  The  resin 
when  hydrolysed  yields  cinnamic  add  and  a 
small  proportion  of  benzoic  acid  and  pervirednO' 
tanncl,  a  resin  alcohol  of  the  formula  Gxfi^O^* 
The  balsam  has  also  been  examined  by  Thoms 
(Arch.  Pharm.  237,  271). 

The  B.P.  demands  that  at  least  67  p.c  shall 
remain  in  ethereal  solution  after  shakmg  with 
NI2  NaOH  solution ;  this  portion,  termed  dnna- 
meln,  must  have  a  sapoxufication  value  of  not 
less  than  236.  The  U.S.P.  requires  an  acid 
number  66  to  84  and  60  to  66  p.c  of  dnnameln, 
extracted  by  ether  from  4*6  p.c.  NaOH  solution ; 
the  saponification  value  of  the  dnnameln  must 
be  236-238. 

A  useful  test  is  that  1  grm.  balsam  should 
give  a  clear  solution  with  3  grms.  chloral  hydrate 
in  2  cc  water.  Among  the  adulterants  used 
have  been  copaiba,  gurjun  colophony,  Ganada 
turpentine,  storaz,  toiu  alcohol,  &c.  The 
presence  of  turpentine  may  be  detected  by 
warming  1  grm.  balsam  with  6  cc  purified 
petroleimi  benzine  on  a  water-bath ;  the  petro- 
leum extract  on  evaporation  shoidd  yield  no 
smell  of  turpentine  and  give  neither  green  nor 
blue  colouration  with  a  drop  of  nitric  acid, 
showinff  absence  of  resin  (U.S. P.).  On  shaking 
the  balsam  with  water,  a  diminution  in  its 
volume  will  occur  if  alcohol  has  been  added; 
the  specific  gravity  also  gives  information  as 
to  the  probable  presence  of  alcohol. 

(For  other  modes  of  testing,  v,  Hirschsohn 
(Pharm.  Zdt  16,  81) ;  Fliickiger  (Pharm.  J.  [3] 
12,  46) ;  SchUckum  (Arch.  Pharm.  [3]  20,  498) ; 
MacEwan  (Pharm.  J.  [3]  16,  236);  Andr^ 
(Arch.  Pharm.  [3]  22,  661) ;  Denner  (J.  Pharm. 
Ohim.  [6]  18,  269).  Testing  of  balsams,  resins, 
and  gum-resins :   Pharm.  J.  [3]  17,  647.) 

A  White  Peru  Balaam  is  sometimes  pre- 
pared in  Salvador  by  expresdon  from  the  nruit 
of  the  Myroxylon  Pereira,  It  is  a  golden  yellow 
semi-fluid  granular  crystalline  mass  containing 
a  crvstallme  resin,  myroxoearpin  Otfiu^t* 
together  with  Myrokne,  slyradn,  and  dnnamie 
ac%d  (Stenhouse,  Annalen,   77,  306;    Pereira, 


532 


BALSAMS. 


Annalen,  77,  300 ;  Schariing,  Annalen,  97»  70 ; 
HarriBon  a.  Malach,  J.  1876,  856).  (For  more 
recent  investigatioiu,  see  Gennann  (Arch.  Pharm. 
234/641) ;  BUtz  (Chem.  Zeit  26, 436) ;  Thorns  a. 
Bilto  (Cham.  Zentr.  1904,  iL  1047) ;  HellBtrom 
(Arch.  Pharm.  243,  218).  For  other  varieties 
of  Pera  balsam,  v,  Fiuck.  a.  Hanb.  210.) 

Storaz,  L/ijuid  Storax ;  BaUamum  Siyracia  ; 
Styrax  praeparaiue,  B.P. ;  Styrax,  U.S. P. 
(Styrax  Liquide,  Fr. ;    Fli^siger  Storax,  Ger.) 

Storax  balsam  is  derived  from  trees  of 
Liquidambar  orientalis  (Miller),  which  are 
natives  of  Asia  Minor  (c/.  BentL  a.  Trim.  107). 
This  liquid  storax  is  nearly  related  to  another 
harder  resin — the  exudation  of  the  Styrax 
officinale  (Linn).  Both  have  been  known 
since  the  later  Greek  period,  but  the  latter  is 
now  no  longer  an  article  of  commerce.  Storax 
has  been  identified  in  the  resins  obtained  from 
embalmed  Egyptian  mummies  dating  back 
about  3000  years  (Tschirch  and  Reuter,  Arch. 
Pharm.  250,  170).  To  obtain  the  storax  the 
outer  bark  of  the  tree  is  removed,  and  the  inner 
bark  is  collected  and  boiled  in  water.  The 
balsam  melts  and  rises  to  the  surface  and  is 
skimmed  off. 

Liquid  storax  is  heavier  than  water,  about 
the  consistence  of  honey,  and  of  a  greyish-brown 
colour.  It  always  contains  a  little  water,  which 
imparts  to  it  a  greyish  opacity.  When  this  is 
removed,  by  long  standing  or  by  heat,  the  resin 
becomes  quite  transparent  Dried  in  this  way  it 
is  soluble  in  alcohol,  ether,  carbon  disulphide, 
and  volatile  oils ;  but  not  in  light  petroleum. 
The  odour  of  storax  is  agreeably  bahamic  and 
the  taste  aromatic  and  pungent.  Examined 
with  a  microscope  crystals  may  be  detected 
which  have  been  identified,  the  feathery  spicular 
crystals  as  styracin,  and  the  rectangular  tables 
and  short  prisms  as  cinnamic  acid. 

Storax  contains  lO'p.c.  to  20  p.c.  of  water,  13 
p.c.  to  18  p.c.  of  woody  and  inoiganic  impurities, 
leaving  56  p.c.  to  71  p.c.  of  matter  soluble  in 
alcohol,  which  consists  chiefly  of  styrene,  meta- 
styrene,  cinnamic  acid,  styracin,  and  a  large 
proportion  of  resin  (Fluck.  a.  Hanb.  275).  The 
alcohol-soluble  part  constitutes  the  styrax 
praepartUus  of  the  B.P. 

Styrene  or  phenylethylene  C^Hg'CH  :  CHj  is 
obtained  as  a  colourless  mobile  liquid  by  distill- 
ing storax  with  water  (Bonastre,  J.  Pharm.  Chim. 
16,  88 ;  Simon,  Annalen,  31,  267).  The  solid 
polymeride  of  styrene,  mdastyrene,  is  also  said 
to  exist  in  storax.  Cinnamic  acid  to  the  extent 
of  6  p.c.  to  12  p.c.  is  obtained  by  boiling  the 
balsam  with  sodium  carbonate  solution,  which 
extracts  it  as  a  sodium  salt  from  which  the  free 
acid  is  liberated  by  mineral  acids. 

Styracin  or  cinnamyl  cinnamate 

C.H.-CH ;  CHCOOC.H, 

was  originally  discovered  in  storax  by  Bonastre. 
It  may  be  obtained,  after  removal  of  the  styrene 
and  cinnamic  acid  by  treatment  of  the  residue 
with  ether,  alcohol,  or  light  petroleum  in  the 
form  of  a  liquid,  which  with  difficulty  assumes  a 
solid  ciystalline  form,  the  crystals  melting  at 
44**  (Simon,  Annalen,  31,  273 ;  Toel,  Annalen, 
70,  1 ;  Miller,  Annalen,  188,  200).  Styracin 
is  readily  converted,  by  alkali  into  cinnamyl 
Icohol  and  cinnamate.  Benzyl  alcohol  has  been 
steoted  as  a  constituent  of  storax  by  Lanben 


heimer  (Annalen,  1 64, 289).  A  eood  bibliography 
will  be  found  in  W.  von  Millers  memoir  on  the 
Chemical  Compounds  contained  in  liquid 
Storax  (Annalen,  188,  184),  in  which  the  author 
describes  as  present,  in  addition  to  the  consti- 
tuents already  mentioned,  phenylpropyl  cinna- 
mate, ethyl  dnnamaie,  ethyl  fxmiUin,  laigo 
quantities  of  two  alcoholic  compounds,  a-  and 
fi'Storesin,  and  their  cinnamic  esters,  a  sodium 
compound  oj  storesin  and  a  resin.  Dieterich 
showed  that  31iller's  ethyl  vanillin  was  really 
vanillin  (Pharm.  CentraUialle,  1896,  No.  28). 
According  to  v.  Itallie  (Chem.  Zmtr.  1901,  iL 
856),  a  good  specimen  of  storax  contains  about 
2*4  p.c.  of  substances  insoluble  in  ether,  23*1  p.c. 
of  &ee  cinnamic  acid,  14  p.c.  of  water,  22*5  p.c. 
of  aromatic  esters,  2  p.c.  of  styrene  and  vanillin, 
and  36  p.c.  of  resin.  The  total  proportion  of 
cinnamic  acid  is  about  43  p  c. ;  the  combined 
acid  occurring  partly  in  the  resin  and  partly  in 
the  aromatic  esters. 

The  B.P.  demands  an  acid  value  between 
60  and  90,  and  an  ester  value  between  100  and 
146 ;  the  U.S.P.  an  acid  value  of  56-85  and  a 
saponification  vahie  of  170-230.  Storax  is  some- 
times adulterated  with  turpentine.  To  detect 
this  Hager  dissolves  the  bamm  in  a  little  warm 
alcohol,  and  shakes  this  solution  with  light 
petroleum.  The  light  petroleum  on  evaporation 
leaves  a  residue  in  which  the  terebfhthinous 
odour  is  concentrated,  and  may  be  readily 
detected.  Further,  the  residue  so  obtained*  in 
the  case  of  genuine  storax,  is  colourless  with  a 
bluish  opalescence,  and  represents  45-55  p.c. 
of  the  original  balsam ;  but  if  turpentine  be 
present  the  percentage  is  laiger,  and  the  residue 
has  a  yellowish  colour  (Ph.  Oenth.  15,  163). 

Closely  allied  to  h'quid  storax  are  the  exuda- 
tions from  the  Styrax  officinale  (Linn.),  Liquid' 
ambar  styraciflua  (Linn.),  a  native  of  North 
America,  the  balsam  of  which  was  examined 
by  Fluckiger  and  v.  Miller  (Arch.  Pharm. 
[3]  20,  646,  .a.  648).  It  is  obtained  in  the 
form  of  a  sticky  grey  mcMS  containing  white 
crystalline  portions  mixed  with  fragments  of 
wood  and  bark.  Its  composition  does  not 
differ  essentially  from  that  of  Asiatic  Storax 
{v,  Itallie).  Liquidambar  formoaana  (Hance) ; 
and  AUingia  excelsa  (Noronha)  (c/.  Fliick.  a. 
Hanb.  276 ;  Tschirch  a.  v.  Itallie,  Arch.  Pharm. 
239,  541). 

Tolu.  BdUamum  tolutanum,  B.P. ;  U.S.P. 
(Baume  de  tolu,  Fr. ;   Tolvbaham,  Ger.) 

Monardes,  in  his  book  published  in  1674, 
describing  the  products  of  we  West  Indies,  is 
the  first  to  mention  balsam  of  tolu.  Soon  after- 
wards it  was  introduced  into  England.  Tola  is 
the  product  of  the  trees  of  Myroxylon  ioluiferum 
(H.  B.  a.  K.),  natives  of  Venezuela  and  New 
Granada,  and  probably  also  of  Ecuador  and 
Brazil.  Considerable  amounts  are  exported  by 
Bolivia.  (For  botanical  characters,  v.  BentL  a. 
Trim.  84.)  V-shapcd  incisions  are  made,  and  the 
concreted  juice  from  time  to  time  collected.  This 
draining  of  the  trees  goes  on  for  eight  months  of 
the  year  (Weir,  Joum.  R.  Hort.  Soc.,  May* 
1864). 

Balsam  of  tolu  is  a  viscid  resin  or  plastic 
solid,  which  on  exposure  hardens  and  is  brittle 
in  cold  weather.  It  has  an  agreeable  odour 
suggestive  of  vanilla,  and  has  a  decided  aromatic 
taste.    Crystals  of  cinnamic  acid  may  be  seen 


BANANA. 


633 


in  tolu  when  thin  layers  are  examined.  It  ia 
soluble  in  alcohol  (1  in  1),  glacial  acetic  acid 
(1  in  I),  chloroform  (2  in  1),  benaene  (1  in  3), 
acetone,  also  in  caustic  potash.  Carbon  di- 
sulphide  dissolves  it  partially,  removing  chiefly 
cinnamic  acid.  Balsam  of  tolu  consists  for  the 
most  part  of  an  amorphous  resin  similar  to  that 
left  by  carbon  disulphide  in  the  case  of  Peru 
balsam.  This  resin  on  hydrolysis  yields  tolu- 
rtsinotawnol  (^ii^xfi^t  a  lower  homoloffue  of 
peruresinotannol,  a  dark  brown  pbwder  decom- 
posing at  100®  without  melting.  It  gives  colour 
reactions  with  ferric  chloride  and  potassium 
dichromate»  and  precipitates  with  lead  acetate 
and  gelatin  (Oberlander,  Ajch.  Pharm.  232, 559). 
Treatment  with  water  extracts  from  balsam  of 
tolu  cinnamic  acid  (Carles,  J.  Pharm.  Chim.  19, 
112),  and  according  to  Busse  (Ber.  9,  830)  it 
contains  also  benzoic  acid,  and  both  benzyl 
benzoale  and  einnamate*  Distilled  with  water, 
small  quantities  of  a  peculiar  hydrocarbon  pass 
over  which  has  been  called  tolene.  The  yield, 
according  to  Deville,  is  2  p.c.  (Ann.  Chim.  Phys. 
[3]  3,  152).  Tolene  has  the  formula  CioHir 
Its  sp.gr.  at  10**  is  0*858  (Kopp),  and  it  boils  at 
IW,  according  to  Deville  and  Scharling,  or  at 
154M60''  (Kojpp).  Deville  found  tolene  to  have 
a  vapour  density  of  5*1.  This  hydrocarbon  does 
not  appear  to  have  been  further  studied  or  to  be 
known  in  any  other  chemical  relation. 

Colophony  present  as  an  adulteration  in 
tolu  may  be  detected  by  extracting  1  grm.  with 
25  C.C.  of  carbon  disulphide  and  filtering ;  on 
evaporation  the  residue,  dissolved  in  glacial 
acetic  acid,  does  not  become  green  on  adding  a 
few  drops  of  sulphuric  acid.  The  carbon  di- 
sulphide, or  light  petroleum  extract,  filtered  and 
shaken  with  0*1  p.c.  copper  acetate,  does  not 
become  green  (Hirschsohn,  Chem.  Zentr.  1895, 
iL  694).  Added  colophony  is  also  detected  by  the 
saponification  number  of  the  residue  left  on 
evaporation  of  the  carbon  disulphide.  If  the 
residue  falls  below  25  p.c.  the  addition  of 
exhausted  balsam  mav  be  suspected.  When 
turpentine  has  been  added,  sulphuric  acid  pro- 
duces a  black  instead  of  the  normal  cherry- red 
colour.  The  U.S.P.  demands  saponification 
value  154-220  and  acid  value  112-168  for  tolu 
balsam;  the  B.P.  requires  107'4-147'2  for 
acid  value,  and  a  saponification  number  of 
107-202. 

Xuithonhcn  Balsams.  A  number  of  bal- 
samic resins  are  obtained  from  the  xanthorrhosas 
or  grass  trees  of  Australia.  Seven  species  of 
these,  the  arborea,  auslralis.  Hostile,  media, 
minor,  bracteata,  and  Pumilio  were  described  as 
earlv  as  1810  by  Brown  (Prodromus  Nov» 
Hollanditt).  The  first  two  are  arborescent  trees, 
the  third  and  fourth  have  short  stems,  and  the 
last  three  are  stemless.  Hirschsohn  (Pharm. 
Zeit  16,  81)  distinguishes  three  xanthorrh»a 
balsamic  exudates;  but  of  these  only  two  are 
important,  the  yellow  or  acaroid  b(dsam  and  the 
red  balsam  (Pereira,  Mat.  Med.  3rd  ed.  1099). 

Acaroid  Balsam,  Acaroid  Resin,  Resina 
,  Acaroides,  Resin  of  Botany  Bay,  This  balsam 
was  first  mentioned  by  Governor  Phillips  in 
1789  (Voysffe  to  Botanv  Bay).  It  exudes  spon- 
taneously nom  the  AarUhorrhcsa  HastiU  and, 
l^cording  to  some  writers,  from  the  X,  arborea, 
it  has  a  yellow  colour  resembling  gamboge, 
and  when  heated  evolves  a  balsamic  odour. 


It  is  used  in  the  preparation  of  sealing-wax  and 
lacquers  and  japanner's  gold'taize.  Rudling 
found  for  the  yellow  resin  an  acid  value  of 
65-90,  a  saponification  value  of  10(^-150,  and 
an  iodine  value  of  175-176  (Chem.  Rev.  Fett 
V.  Harz.  Ind.  1903, 10, 51).  It  mav  be  identified 
by  heating  with  nitric  acid,  dissolving  the  cold 
residue  in  alcohol  and  adding  10  drops  of  5  p.c 
ferric  chloride  solution.  A  brownish-black 
colour  and  turbid  appearance  denotes  the 
presence  of  acaroid  resin  (Bebs,  Lack.  und. 
Farb.  Ind.  1908,  No.  11).  Its  chief  constituents 
are  resin,  a  trace  of  volaixU  oil,  and  cinnamic^ 
benzoic,  and  para-coumaric  acidst  also  pora- 
hydroxybenzaidehyde  and  probably  vanillin  (Bam- 
berger, Monatsh.  14,  333).  The  resin  consists  of 
xanthoresinotannol  Ci^^^Oxo*  chieflv  in  form 
of  para-coumarate  (Uildebrand,  Arch.  Pharm. 
234,  698).  (For  properties  of  xanthorrhoea 
resin  oil,  see  Schinunei  and  Co.  (Chem.  Zentr. 
1898,  i.  258);  Haensel  (Chem.  Zeit,  1908,  I 
1837).)  Bv  distilling  acaroid  balsam,  Stenhouse 
obtained  a  ught  neutral  oil  containing  benzene  and 
cinnamene,  and  by  treatment  with  nitric  acid 
the  same  observer  finds  acaroid  balsam  to  give  so 
ku^e  a  yield  of  picric  acid  that  he  recommends  it 
as  a  convenient  source  of  that  compound.  As 
much  as  13  p.c.  of  parahydroxybenzoic  add  is 
formed  when  acaroid  balsam  is  fused  with  potash. 
Amongst  the  other  products  of  this  reaction,  are 
resorcinol,  pyrocaiechol,  and  a  double  compound  of 
para-hydroxybenzoic  and  protocatechuic  acids 
Ci4H,,07,2HjO,  which  has  been  likewise  ob- 
tained from  benzoin  (Hlasiwets  and  Barth,  J* 
1866,  630). 

-  Red  Acaroid  Balsam,  Orass-tree  Oum.  Black* 
boy  Oum.  A  red  balsamic  resin  resembling 
diBgon's  blood,  and  obtained  chiefly  from 
XanthorrhcBa  auslralis.  When  heated  it  evolves 
a  balsamic  odour.  This  resin  does  not  contain 
cinnamic  or  benzoic  acid,  it  contains  a  small 
quantity  of  para-hydroxybemaldehyde,  and  con- 
sists mainly  of  crythroresinotannol  C^%S.j^Oiq, 
chieflv  as  para-coumarate  (Bamberger,  Hilde* 
brand).  Its  solution  in  alcohol  stains  a  deep 
mahogany  colour.  A  red  acaroid  balsam  is  also 
obtained  from  the  Bahamas,  which  is  lighter  in 
colour  than  the  Australian  variety.  It  is 
Mmilii.r  in  composition  to  the  latter,  except  that 
it  contains  cinnamic  acid.  Grass-tree  resins 
are  used  in  the  preparation  of  spirit  hioquers, 
varnishes,  sealing-wax,  &c.  During  the  Euro- 
pean War  considerable  quantities  of  picric  acid 
were  made  from  the  different  varieties  of 
xanthorrfuBa  resins. 

BAMBARA  FAT  v,  Bassia  oils. 

BAMBOO*  The  ash  of  the  shoots  of  these 
grasses  {Bambusa  arundinacea  (Willd),  Gigan- 
tochloa  verticillata  (Munro),  &c.)  contains  fiom 
30  to  40  p.c.  of  potash  (K,0),  and  constitutes  a 
good  source  of  potash.  The  fibres  of  the  shootii 
supply  an  excellent  paper- making  material, 
and  have  been  used  for  this  purpose  by  the 
Chinese  from  time  immemorial  (Romanis, 
Chem.  News.  45,  158 ;  46,  51  ;  Nature,  18,  60). 

BAMBOO!  FAT  or  BAMBUK  BUTTER  t^. 
Bassia  on^s. 

BANANA.  The  fruit  of  Musa  sapientium, 
a  plant  growing  freely  in  tropical  countries. 
When  ripe  the  pulp  is  rich  in  sucrose  and  invert 
sugar,  but  in  the  unripe  condition  contains  much 
staroh»  and  is  extensively  used  for  the  prepaia- 


§u 


BANANA. 


tion  of  baiian*  flour  in  the  Indi&n  Archipelago, 
Brazil,  the  west  coMt  of  Africa,  and  the  Pacmo 
IslandiB. 

Analyses  by  Lenscher  (Zeitsch.  offentL 
Chem.  1902,  8,  125)  of  (1)  green  husks,  (2)  ripe 
husks,  (3)  unripe  fruit  (pulp),  (4)  ripe  fruit  (pulp), 
and  (5)  banana-meal,  are  as  foUovs : — 


(1) 

(2) 

(3) 

(4) 

(6) 

Water      . 

.     700 

70-0 

70-6 

671 

16-0 

Crude  protein   . 
Crude  fat 

2*0 

2-9 

3-9 

5-0 

7-0 

.      45 

41 

01 

0-2 

0-3 

Crude  fibre 

9-9 

8-6 

0*4 

0-3 

6-91 

N-free  extract  . 

8-3 

10-4 

— . 

— . 

70-0 

Starch      . 

,        — — 

— 

191 

— 

Dextrin    . 

— 

^— 

2-6 

1-0 

Tannin     . 

,        — 

— 

2-2 

01 

Sucrose    • 

»       -*- 

— 

— 

15-8 

Invert  sugar 

— 

— 

—' 

9-7 

Ash 

6-3 

3-9 

11 

0-9 

1-8 

Only  the  quite  green  fruit,  containing  mere  traces 
of  su^ar,  can  be  used  for  preparing  the  meaL 

Ripe  bananas  contain  inveiiase  (Mirran, 
Chem.  Zeit  1894, 17, 1283).  American  analyses 
show  much  less  protein  in  ripe  bananas  than 
is  given  in  Leuscher's  figures,  tne  average  being 
only  1-3  p.0.  (Bulletin  28,  U.S.  Dept  of 
Agriculture,  1899). 

The  pulp  appears  to  contain  small  quantities 
of  amy!  acetate,  to  which  ita  chancteristic 
aroma  is  due. 

For  a  study  of  the  relative  amounts  of 
sucrose,  invert  sugar  and  starch  present  in  the 
fruit  dried  at  temperatures  between  40®  and 
lOS"",  He  Waterman  (Chem.  Weekblad,  1915, 
12, 552).  For  a  study  of  the  changes  in  composi- 
tion of  ripening  bananas,  see  Gore  (J.  Agrio. 
Research,  1914,  3,  187). 

The  stalks  and  skins  of  bananas  are  rich  in 
potash,  and  have  been  suggested  as  worth 
coUecthig  for  manurial  purp68e8  (Ellis,  Jour.  Soc' 
Chem.  Ind.  1916,  456  and!^521).  The  following 
figures  were  quoted : — 

StaUa.  Skins. 

Moisture    .         •         •     91*6  p.c      88-2  p.o. 
Dry  matter         .         .       8*4  „         11-8  „ 
Ash,  in  original  •      2*4  „  1-8  „ 

Potash,  in  original       .       1  *1  „  1 0  „ 

Ash,  in  dry  matter      .     29*9  „         15*0  „ 
Potash,  in  dry  matter .     13*7  „  9*0  „ 

Potash  in  ash     .         •      45*9  „        57*2  „ 

It  is  estimated  that  the  bananas  imported 
into  this  country  per  annum  (about  9,000,000 
bunches)  include,  on  the  average,  about  16,000 
tons  of  stalks  and  60,000  tons  of  skins,  containing 
about  1 60  tons  and  600  tons  of  potash,  respectively. 

BANDROWSKI'S  BASE.  Tetraamino- 
diphenyl^-asophenylene. 

BAPTISIN  V.  Glucosidxs. 

BAPTITOXINE  v.  Cytisikb. 

BARBALOIN  v.  Glucosidxs. 

BARBATIC  ACID.  BarbtUic  add  C^^RtoO, 
was  first  isolated  from  the  lichen  Umea  harbaia 
by  Stenhouse  and  Groves  (Chem.  Soc.  Trans. 
1880,  37,  405),  in  which  it  occurs  in  conjunction 
with  usnic  acid  Zopf  (Annalan,  1897,  297,  271) 
found  barbatic  acid  m  the  Uan^t  Umgiseimat  in 
the  Sledora  oehroie  uea  {ibid,  1899, 306, 282),  and 
in  the  Uenea  dasypoga  (ibid.  1902,  324,  39) ; 
Hesse  (J.  pr.  Chem.  1898,  IL  57,  232)  describes 
its  presence  in  the   Uanea  longissima,   Usnea 

I  liMludlsg  taaaln  and  ooiourljig  matter. 


bofhata,  and  Uenea  eeraUna,  Hesse  (Lc 
originally  considered  that  barbatio  acid  had  the 
composition  CtJ^i^fi^  and  described  potassium 
barium  and  copper  salts  and  an  etnyl  ester, 
m.p.  132%  which  apparently  established  this 
formulsy  but  in  a  later  paper  (J.  pr.  Chem.  1903. 
ii.  68,  1)  he  adopted  Stenhouse  and  Groves' 
formoJa,  Ci^HmOt*    The  sodium  saU 

OitHifOfNa,  2HtO 

orystallises  in  straight-sided  leaflets  (</.  also 
Zopf,  1902, 789).  The  action  of  acetic  anhydride 
on  barbatic  acid  leads  to  the  formation  of  a 
compound  which  is  probablv  the  lactone  of 
acetylbarbatio  add ;  this  melts  at  250®  and  on 
reorystallisation  from  acetic  anhydride  yields 
acetylbarbcUic  add  Ci»Hi»(C,HsO)Oy,  m.p.  172% 
By  the  hydrolysis  of  barbatic  acid  with  aqueous 
alkaliB  betordnol  and  rhizoninic  add  are  formed. 
Barbatio  add  crystallises  in  colourless  needles, 
m.p.  184**  (Hesse,  J.  pr.  Chem.,  1906  (2),  73, 
113).  A.  G.  P. 

BARBERRY.  Barbeiiy  or  berberry,  Ber- 
beris  vuJffaris,  is  a  compact  bush  which  attains 
to  a  height  of  from  8  to  10  feet,  and  is  found  wild 
in  Great  Britain  and  throughout  most  parts  of 
Europe  and  North  America.  The  colouring 
matter  present  is  berberine^  and  this,  though 
occurring  mainly  in  the  bark,  is  also  present  in 
the  stem  and  root  of  the  plant. 

Until  recently  a  concentrated  commercial 
extract  of  this  material,  known  as  'Barberry 
extract,'  was  to  be  found  on  the  market,  and 
employed  for  dyeing  sUk  and  leather.  It  does 
not  appear  to  have  been  at  any  time  extensively 
used  for  these  purposes,  and  is  now  apparently 
obsolete* 

BiSoerry  is,  however,  interesting,  in  that  it 
contains  the  only  natural  basic  dyestuff  at 
present  known,  and  may,  in  fact,  be  applied 
to  fabrics  in  the  same  way  as  the  luidfidal  basio 
colouring  matters.  Silk  and  wool,  for  instance, 
may  be  dyed  yellow  by  means  of  a  &intly 
acidulated  decoction  of  the  material,  preferably 
at  from  50®  to  60®,  whereas  for  cotton,  a  tannin 
antimony  mordant  is  necessary. 

For  tiie  isolation  of  berbenne  the  procedure 
is  simple,  and  consists  merely  in  extraotm^  the 
ground  dyestuff  with  boiling  water  oontaimng  a 
slight  excess  of  lead  acetate.  The  concen- 
trated extract  is  mixed  with  hydrochloric  add 
when,  on  cooling,  ciystals  of  berberine  hydro- 
chloride separate.  Berberine  hydrochloride, 
C.0H19O4NCI,*  when  pure,  crystallises  in  long 
silky  needles  which  possess  an  intense  yellow 
colour  and  are  soluble  in  hot  water  and  alcofaoL 
The  most  reliable  of  the  earlier  analyses  of 
berberine  are  those  given  by  Perrins  (Annalen, 
Supp.  2,  176),  who  suggested  the  formula 
CioHitNOa,  but  it  is  now  imown  that  berberine 
has   the   composition   C^JB^ifiO^    The    base 

^  The  substance  commoDly  known  as  ft#»<rftis  Jfcyrfw- 
dUorHie  U,  In  fact,  not  a  hjdrochloiide,  but  a  qnatemanr 
chloride  containing  the  gronplng  given  below,  and 
should  be  named  hefberif^m  eklorioe  (W.  H.  Perkin, 
Chem.  Soc.  Trans.  1018, 118  608)— 


The  old  names  for  this  and  the  other  salts  described 
are,  however,  retained  in  this  article. 


berberine  (or  betberinal)  i«  best  obUuned  by 
•  addiiig  ■truDs  caustio  aoda  (o  the  ftqueoiu 
eolutjon  of  the  Bulphate  ui3  extracting  the 
product  with  ethar,  from  which  it  MpKratea  in 
j-elloir  needles  ajid  mella  at  141''  (Gadun«r, 
Arohiv.  der  Pharm.  190Q,  243.  34).  Berberiae 
'a  a  atrong  bftse,  yielding  w?ll-deGned  orystaJlius 
aaJts  of  a,  deep  yellow  oolour,  of  which  th* 
following  may  be  given  as  eiamples  : — 

Btrberine  niirale  C,^i,NO,-NO„  BerbtnTit 
hyirochloridt,  C„H,^0,C1,  Berberine  h^diiodidt 
Ci^nNOJ.  and  Berbaint  plalinieNoridt 
(C„H„NO,)^tar 


IS64,  407),  who  by  raduoing  the  base  with 
and  eulphurio  acid  pteparod  UlTaAydroberben 
C,gH,,N04,  and  by  fusion  with  alkali  obtained 
the  acids  C,H,0,  and  C.H,0(,  the  seoond  of  which 
was  termed  berbtrinic  Mid.  Ferkin  (Chem.  Soc. 
Tmu.  16S9, 65,  89),  who  aubsequently  examined 
this  latter  compound  and  found  that  its  proper- 
ties agreed  in  all  respects  with  those  given  by 
^aaivetE  and  Gilm,  has  shown  that  it  pogseeaes 
the  constitution  of  a  ImmocaUchoi  airboxylic  acid. 

Interesting  also  is  the  fact  that  by  the  alkali 
fuaofi  of  berberine,  or  by  distiUini;  it  with  lime, 
Bemheimer  and  B5decker  isolatea  an  oily  base 
which  thsy  regarded  as  quinoline,  but  which  is 
now  known  to  be  iio-quinoiint. 

The  most  valuable  reeulta,  bowsrer,  have 
been  aSorded  by  a  atady  of  the  oxidation  pro- 
ducts of  berberine  hydrocblondo.  Weidel,  who 
employed  nitric  acid  for  t.liiii  purpose,  obtained 
berberonie  acid,  C,H,NO,.  which  he  rightly 
r^arded  as  a  pyridine  tncarboxylie  acid,  and 

this  has  been  more  recently  ahown  '  ~ ''    ' 

the  2:4:  S  compound^ 
N 

coohI^ 

COOH 
whereas  Schmid  and  Sohilbach  (Arch.  Pharm.  [3], 


iO/^|COOH 


*3a 

is,  164)  by  the  action  of  perauuiganata  obtainwl 

quantity  of  itmipinie  acid-- 

COOH 
MeOi^ 
Meot^ 

Subsequently,  W.  H.  Perkin,  jour.  (Chem. 
Soo.  Trans.  1889.  66,  75 1  IS90,  57,  991  ;  1910, 
97,  323)  published  a  series  of  elaborate  researches 
on  this  subject,  and  it  is  almost  entirely  to  these 
that  oui  present  knowledge  ol  berberine  ia  due. 
By  adopting  special  preoaulions  and  by  the 
employment  of  a  very  large  i^nantity  of  material, 
this  antbor  succeeded  in  obtamins  from  berberine 
hydrochloride  by  the  action  olpemiai^anate, 
numerous  importaot  compounds,  the  study  of 
which  gave  the  clue  to  its  constitution.  The 
operations  employed  are  of  too  involved  a  nature 
to  be  dealt  with  in  detail  here,  but  a  general  idea 
of  the  methods  employed  can  be  gathered  from 
the  scheme  given  below,  drawn  up  by  the 
investigator  bmiself  (I.e.  1890). 

Among  the  oxidation  products  of  berberine, 
anhydroberberilto  acid  and  berberal  have 
proved  to  be  the  most  important,  and  these  only 
trill  be  discussed  here  in  detail. 

AnAydrobtrbrrilie  acid  C.gHnNO,.  h  it* 
name  denotes,  is  an  anbydro  derivative  of 
berberilic  acid,  into  the  sodium  salt  of  which 
it  is  readily  transformed  by  the  gentle  action  of 
sodium  hydroxide  solution— 

C,^i  ^0,  +  2N»0H =C,^,^0,Na,-|-H,0 
Berberilic  acid,  C.^nNO*,  though  only  slowly 
attacked  by  alkalis,  is  readily  hydrolysed  by 
boiling  dilute  sulphuric  acid,  and  Ferkin  thus 
obtained  hemipinic  acid  and  a  basic  oompotmd 
C„H„NO,— 


-COOH 

Njooh 

irWyltc  acid— 


TtUae  Ntrait  ■vapitaUd  U>  Half  Its  Bulk  and  filtered. 


bviji<>cen 
BUlphlir. 


berbcrUlD 

add, 
J„H,^0, 


berine. 

anhydio- 

betberiUc 


m  «vipont«d, 
luu  aiKllum  eai- 
aod  ailwsd  hut. 


D„H,KO,j 


acid  and  flIUied. 


'aoa* 

£dd! 
c.^„o. 


•old, 

^lii'lplper- 

oxyUc  ao- 
lirdrlde. 


636 


BARBERRY. 


CH,— O 
\)[^NC00H 


U' 


and  the  main  facts  which  lead  to  the  detennina- 
tion  of  its  constitution  are  as  follows  : — 

When  boiled  with  water,  it  readily  loses  the 
elements  of  water  with  production  of  the 
anhydrido — 

vOv  /CO — ^NH 

^•<o>*<ch.Jh. 

which  reacts  with  nitrous  acid  to  give  the  nitroso 
derivative — 


.0 


CO  •  N-NO 


and  this  compound  with  dilute  caustic  soda 
evolves  nitrogen  with  the  production  of  «•%- 
droxyeihylpiperonyl'Carboxylic  acid — 


CH,/ 


o>'< 


COOH 
CHjCHaOH 


The  anhydride — 


/Ov  /CO— O 

^0^  \CH,CH, 

readily  obtained  from  this  latter  by  merely 
boiling  with  water,  when  fused  with  alkali  yields 
catechol  and  protocatechuic  acid — 

OH^^H.COOH 

and  by  the  action  of  hydrochloric  add  at  170°- 
176°  is  converted  with  loss  of  carbon,  a  reaction 
characteristic  of  piperonal  derivatives,  into 
hydroxyeihylaUechol-carboxylic  anhydride — 

,0^  XO — 0 


ch/  \c,h/        I 


OHv  .CO — O 

=       >C.H,<(  J      +C 

OH/  XIHj-iH, 

A.S  the  result  of  these  experiments,  there  could 
be  little  doubt  that  berberilic  acid  (1)  and  its 
anhydride  (2)  possess  the  constitutions  given 
below — 


(1) 


OMe 
MeO/\— COOH 


cooh/\o^ 


(2) 


— CO— NH-CHjCH,— is^o/ 
OMe 
^eO/\-CO  COOH/\Oy^ 

\^-C0— N-CH,CH,-!^0/ 

and  that  these  are  correct  was  subsequently 
established  by  the  observation  that  the  hemipi- 
nate  of  vaminoethylpiperonyl-carboxylio  acid 
(3)  on  heating  is  transformed  into  anhydro- 
berberilic  acid — 


(3) 
MeO 


Me 


> 


/Ov 


/COOH  COOH.  ^. 

•^«\  )C,H,(    )CH, 

\;OOH,NHa-CH,-CH/         ^G^ 


Bcrbcralf  As  in  the  case  of  berberilio 
acid,  the  constitution  of  berberal  has  been 
established  mainly  by  a  study  of  the  products 
of  its  hydrolysis.  By  the  action  of  alcohoUo 
potash  it  yields  ev-aminoethylpiperonyl-car- 
boxylic  acid  and  an  acid  CioHioO,,  and  tiius 
resembles  berberilic  acid  which  under  similar 
conditions  gives  hemipinic  acid  in  the  place  of 
this  latter. 

The  acid  CioHioO,  on  examination  proved  to 
be  constituted  similarly  to  opianic  acid  (1),  and 
was,  therefore,  termed  pseudo-opianic  acid  (2)— 


MeO 
MeCfNcOH 


(2)  \/COOH 


MeO 

Meo/NcOOH 
(1)  IJCOH 

Thus  by  the  action  of  caustic  potash  solution  it 
gave  veratric  acid — 

MeO 

MeOfl 

l^COOH 

and  when  reduced  formed  the  unstable  acid  (3) 
which  readily  passed  into  pseudomecanine — 
MeO  MeO      p„ 


MeOf     ICH.OH 
(3)         Is^COOH        W 


MeOj^''^^ 


O 

^''^^CO'^ 

Perkin  now  found  that  whereas  pseudo-opianic 
acid  and  w-aminoethylpiperonyl-carboxylic  acid 
on  heating  together  give  first  the  salt  of  the  base, 
that  this  subsequently  by  elimination  of  water 
passes  into  berberal — 

CioHioO,+Ci^,NO,=CjoH„NO,+H,0 

Apparently,  therefore,  berberal  could  be  repie- 
sented  as  follows  : — 

MeO  0 CH, 

MeO/\-COH     ^^CO— /\o/ 

'\^-C0— N— CH,-CH,ls^ 

and  this  formula  was  at  first  adopted. 

Liebermann,  however  (Ber.  1896,  29,  175), 
subsequentiy  pointed  out  that  when  opianic 
acid  reacts  ^ith  aniline  to  form  anilinoopiamo 
acid  (1)  the  latter  behaves  as  a  derivative  of 
hydroxyphthalide  (2) — 


^^  /CO 
MeOfY     N 


MeO 


MeOf^, 
(2)        IJ. 


XO 

c> 

M)HOH 

and  it  is  now  generaUy  accepted  that  in  the 
condensations^  of  opianic  acid  with  basic  sub- 
stances, it  is  always  the  carbon  atom  of  the 
aldehyde  group  which  becomes  attached  to  the 
nitrogen  in  the  final  product. 

As  a  result  of  this  later  work,  Perkin  and 
Robinson  have  modified  the  original  ex- 
pression for  berberal  as  follows : — 


MeO 
MeO 


yCH N-CH,CH/^N 


CO" 


Su^"' 


An  examination  of  the  formula  both  of  berberilio 
acid  and  of  berberal,  led  Perkin  in  1890  to  the 


BARBERRY. 


637 


consideration  that  in  berberine  the  following 
groups  of  atoms  are  present — 

MeO 
MeOf^^C  and  -N-CH,-CH,- 


^^ 


•"0-.- 


and  that,  in  order  to  construct  a  formula  for  this 
alkaloid,  these  require  to  be  united  with  the 
addition  of  but  one  atom  of  hydrogen.  As  a 
result  the  following  constitution  was  assigned  to 
this  alkaloid — 


Clf,~0 


N  CH, 


this  structure  being  based  upon  the  older 
formula  of  berberine,  CtoHirN04,  which  at  that 
time  was  considered  to  be  correct 

Subsequently  Perkin  and  Robinson  pointed 
out  that  the  methylenedioxy-group  in 
Perkin^s  original  formuJa  had  been  in- 
correctly placed,  as  was  evident  from  an 
examination  of  the  structure  of  w-amino- 
ethylpiperonyl-carboxylic  acid  (c/.  also  Freund 
and  Beck,  Ber.  1904,  37,  4673).  Moreover, 
as  a  result  of  the  newer  views  of  the  former 
authors  as  to  the  constitution  of  berberal  {l.c.) 
the  position  of  the  methoxy  groups  iA»  the  old 
berberine  formula  required  modification.  It  is 
now  considered  that  berberine  has  the  formula 
CgoHisOgN,  and  is  represented  by  formula  (1), 
and  that  for  the  purpose  of  salt  formation  it 
undergoes  change  into  the  modification  called 
berberinium  hydroxide  (2),  from  which  the  salts 
are  obtained  by  the  replacement  of  the  OH 
group  by  the  acid  radical — 


berberine  are  derived  from  the  hydroxyl  formula 
and  contain  the  grouping — 


\c/\/ 


(where   X=C1,  HSO4,  NO.,   &o.),  the  alkaloid 
itself  exists  as  a  different  modification. 

When  berberine  sulphate  is  treated  with 
barium  hydroxide  (Gadamer),  a  strongly  alkaline 
liquid  is  produced  which  possibly  contains  the 
hydroxy  modification  of  berberine  (berberinium 
hydroxide),  but  if  to  this  solution  excess  of 
sodium  hydroxide  is  added,  the  yellow  modifica- 
tion known  as  berberinal  is  obtained.  The  con- 
stitution assigned  to  this  substance  by  Gadamer 


was— t 


O CH, 


MeOl     J> 


.CH 


Sc 


MeO^HO^^^ 


a 


CH, 


but  it4  most  probable  structure  is  that  repro 
sented  by  the  formula — 

O CH. 


/V*^^^c/" 


O CH, 


(1) 


MeO 


MeO       I  CH, 

on 


JcH. 


O CH, 


(2)      /\y^^\c/\y 


MeO 


O^  ^"«' 


The  reasons  for  this  assumption  (W.  H.  Perkin, 
jun.,  Chem.  Soc.  Trans.  1918, 113,  503)  are  based 
on  the  similarity  between  berberine  and  cotar- 
nine,  but  are  too  complex  to  enter  into  in  this 
article,  and  for  their  understanding  the  literature 
must  be  consulted  (c/.  Robinson  and  Robinson, 
Irans.  1917,  111,958). 

Interesting  is  the  fact  that  though  the  salte  of 


"^     o'h  ' 

(cp.  Tinkler,  Chem.  Soc.  Trans.  1911,  90,  1315). 
When  treated  with  excess  of  alkali,  berberinal 
yields  dihydroberberine  (1)  with  simultaneous 
formation  of  oxyberberine  (2),  owing,  according 
to  Gadamer,  to  the  conversion  of  the  COH  group 
into  CH,(OH)  and  COOH  in  the  manner  cha- 
racteristic of  aromatic  aldehyde 


(1) 


CH< 


MbO    ^«         OH, 


O CH, 

0/ 


O CH, 

0/ 


(2) 


0 


/^\c/ 


0 


MeO    ^"  CH, 

The  latter  compound  was  first  obtained 
by  Perkin  as  an  oxidation  product  of  ber- 
berine. 

On  the  other  hand,  Faltis  (Monatsh.  1910, 
31,  557)  considers  the  reaction  of  berberinal  wiUi 
alkali  to  be  similar  to  that  which  takes  place 
between  quinoline  methiodide  under  the  same 
conditions  and  that  the  products  of  the  reaction 
are  oxyberberine  and  tetrabyto^^tberine  (c/. 
Dekker,  1903, 1205  and  2668>.     It  ^las.  however. 


638 


BARBERRY. 


view 
c6m- 


been  shown  conclanvely  that  Faltis' 
is  incorrect  (W.  H.  Perkin,  private 
munication). 

Berberine  is  closely  allied  to  hydrastine, 
which  occurs  along  with  it  in  hydrastis  canadensis, 
and  the  relationwip  between  these  compounds 
is  clearly  evident,  if  the  formula  of  Gadamer  for 
berberinal  and  that  of  hydrastine  {see  above) 
are  compared — 

O CSH, 


MeO 


0 

MeO 


\CH0  ^°N 


BerbexinaL 


0 

CHt 


MeO 


O CH, 

0"^ 


HydrasUoe. 


In  1911  Pictet  and  Gams  (Ber.  1911,  44, 
2480)  were  successful  in  effecting  the  synthesis  of 
berberine  by  the  following  series  of  reactions. 

Homopiperonylamine, 

CH,  :  0,  :  CgH,CH,-CHaNH, 

by  condensation  with  the  chloride  of  homo 
veratrio  acid, 

(CH,0),C,H,CH,C0C1, 
yields  homo-veratroyl-homopiperanylamine  (1)  — 


(1)       ,/V^«\co 


0 CH, 

(T 


MeoLy 
MeO 


\^,^^' 


and  this  compound  on  treatment  with  phos- 
phorus pentozide  in  the  presence  of  boiling 
xylene  is  transformed  into  the  dihydro-quinoline 
base  (2).  By  reduction  with  tin  and  hydro- 
chloric acid  this  passes  into  vercUrayl-methykne- 
dioxy-telrahydro-iso-quinoline  (veratryl  norhydrO' 
kydrastinine)  (3) — 

0 CH. 

(2)  /\/^^t\c/\/ 


MeO 
MeO 


CH, 


(3) 


O CH» 

(Y 


NH       'CH, 
CHt 


which  on  treatment  with  methylal,  CH^iOCH^)^ 
gives  tetrahydrcberberine  (4),  a  compound 
originally  prepared  by  HLadwetz  and  Gilm,  and 
subsequently  examined  by  Perkin  and  others. 
This  b^  the  action  of  mild  oxidising  agents  such 
as  iodme  or  merourio  acetate  is  reamly  traos- 
formed  into  berberine  (d) — 

O CH, 

o/ 


•\chA^ 


OH 

For  the  synthesis  of  oxyberberine  the  paper  of 
Pictet  and  Spengler  (Ber.  1911,  44,  2036)  must 
be  consulted. 

Numerous  plants  contain  berberine,  and 
though  most  of  these  have  been  or  are  used 
medicinally,  their  employment  for  dyeing  ha« 
apparently  been  of  rare  occurrence.  The 
following  list  embodies  most  of  these : — 

Berberis  aquifalium  (Gordin,  Areh.  Pharm. 
1902,  240, 146),  B.  oeinensis  (Perkin,  Chem.  Soc. 
Trans.  1897,  71,  1198),  Cossiniutn  feneslnUum 
and  Xanihorrisa  aquifoUa  (Perrins,  Amialen,  83* 
276),  Hydrastis  canadensis  (MaUa,  Amer.  Chem. 
J.  [2],  33,  843),  Cojpiis  acela  and  C.  tHfoUa, 
CheUdonium  majus  and  Stylophorum  diphj/Uwn 
(Schlotterbeck,  Amer.  J.  Phann.  1902,  74,  584), 
Evodia  meHafoUa  and  Toddalia  aouleata  (Peikin 
and  Hummel,  Chem.  Soa  Trans.  67,  414), 
Xanihoxylum  dava  Herculis  (Chevallier  and 
PeUetan,  Joum.  de  Chim.  M^cale,  1826,  2, 
314),  yellow  Assam  wood  or  'Woodumpar' 
(Crookes*  Dyeing  and  Calico  Printing),  Cododine 
polycarpa  (Stenhouse,  Annalen,  66,  384 ;  69, 40), 
Archangdisa  lemnis-cata  ^Beoc.)  and  Makonia 
nepalensis  (D.C.),  (Brooks  Philippine  Joum.  of 
Science,  1910,  v.  442). 

For  the  commercial  preparation  of  berberine 
the  Hydrastis  canadensis,  which  contains  about 
4  p.c.  of  the  alkaloid,  forms  the  best  available 
material.  A.  6.  P. 

BARBITAL  and  BARBITONE.  iSfee  V ebonal, 
Pybimidinbs  and  Synthbtio  Dbuos. 

BARBITURIC  ACID  v.  Malon yl  cab  ba  mtdb. 

BARILLA  or  BARILLOR.  (Fr.  Barilk.) 
Commeroial  name  of  an  impure  soda  obtained 
^m  the  ashes  of  the  Salsola  Soda  (Linu.), 
formerly  grown  specially  in  Spain,  Sicily, 
Sardinia,  the  Canary  Islands,  and  the  Levant. 
The  seed  was  sown  at  the  end  of  the  year,  and  the 
plants  were  ready  for  cutting  in  September  of  the 
following  year ;  they  were  usually  burnt  during 
October.  A  hole  capable  of  hokUng  one  or  two 
tons  of  soda  was  dug  in  the  ground  and  covered 
over  with  an  iron  grating;  the  dried  plants, 
mixed  with  canes,  were  heaped  on  this  and  set 
on  fire.  The  heat  was  sufficient  to  melt  the  ash, 
which  ran  down  and  ooIlMted  in  the  hole.    Move 


BABIUM. 


639 


material  was  supplied  to  the  fire  till  the  hole  was 
full  of  fused  Booa;  it  was  then  covered  with 
earth  and  left  to  cqoI,  after  which  the  porous 
mass  was  broken  out  and  was  ready  for  shipment. 
Contained  about  20  p.c.  alkali,  together  with 
chlorides  and  sulphates  of  sodium,  calcium  and 
aluminium  and  very  little  sulphur.  Formerly 
much  used  for  making  soda  soap ;  little,  if  at 
all,  used  now. 

Kelp  is  sometimes  called  British  Barilla. 

BARIUM.    Symbol,  Ba.    At  wt.  137-37. 

The  name  *  baroto  *  (from  Pap^s,  heavy)  was 
given  to  the  earth  contained  in  heavy-spar 
{terra  ponderoaa)  by  Guyton  de  Morveau  in 
1779,  and  was  afterwards  altered  to  '  baryte '  by 
Lavoisier ;  the  name  itself,  therefore,  is  indica- 
tive of  the  great  densitv  of-ito  compounds. 
Barium  oooun  prindpally  as  the  sulphate, 
barjftis  or  heavy-ipar  iBaSO^,  and  is  generally 
found  associated  with  metallic  ores  containing 
sulphur.  Dieulafait  (Ann.  CSiim.  Phys.  [6]  16, 
630)  has  shown  that  all  primary  rocks  oonteiu 
barium  in  sufficient  quantity  to  be  easily 
detected.  Barium  also  occurs  in  nature  as 
wUheriU  BaCO,,  harifUxeiMliU  (BaSrCa)S04, 
barytoealcite  (BaOa)CX)„  aUtonite  (BaOajCO,, 
ana  in  certein  varieties  of  the  ores  of  manffanese ; 
also  in  certain  silicates,  as  brewtUrite  U4(SrBa) 
A]J3i,Oi„3H,0,  harmoicme  H«(K,Ba)Al^i.Oi,* 
4^0,  and  hytiopJume  or  htuyta'/elapar  K«Ba* 
2Af|8igOs4,  *^d  frequently  in  mineral  waters. 
Barium  is  also  frequently  found  in  calcium  and 
strontium  minerals,  replacing  a  portion  of  those 
elements  with  which  it  is  isomorphous. 

It  is  never  found  native.  Ite  oxide,  baryta 
BaO,  was  first  recognised  as  a  peouliu  eajrth 
distinct  from  lime  by  Scheele  in  1774. 

Preparation.— D&Yj  (PhiL  Trans.  1808,  364) 
electrolysed  a  moist  paste  of  a  barium  salt, 
usin^  a  oathode  of  mercury.  He  thereby 
obtemed  a  poor  amalgam  which  on  distillation 
yielded  a  silver-white  solid  that  he  believed  to  be 
metallio  bsrium,  but  which  in  reality  was  only 
a  rich  amalgam  as  shown  by  Donath  (Ber. 
12,  746}. 

Bmisen  (Pogg.  Ann.  91, 619)  slightly  modified 
Davy's  process,  heating  the  amalgam  in  a 
oharooal  boat  in  a  current  of  hydrogen,  obtaining 
a  tumefied  mass  which  was  probaoly  a  mixture 
of  hydride  and  oarbide.  Quntz  has  also  shown 
that  Kern's  method  (Chem.  News,  31,  243)  of 
heating  the  iodide  with  sodium  yields  a  sub- 
iodide  which  decomposes  water. 

Clarke  (Ann.  PhiL  17,  419)  exposed  baryte 
to  the  action  of  the  oxy-hydrogen  Uow-pipe 
flame  on  charcoal  and  obtained  metcdlio-looking 
globules  probably  of  barium  carbide. 

Matthiessen  (Annalen,  93,  277)  electrolysed 
the  fused  chloride  and  obteined  metallic- 
looking  globules  which  were  probably  sub- 
chloride. 

Maquenne  (Bull  Soc.  chim.  (3)  7,  368) 
heated  the  amalsam  tii  vacuo,  but  owing  to 
decrepitetion  of  we  substance  and  rupture  of 
the  tube  he  was  unable  to  obtein  satisfactory 
results. 

Gunts  (BulL  Soc.  chim.  [3]  29,  483),  by 
studving  the  same  process,  was  finally  able  tK> 
distil  on  all  the  mercury  without  decrepitetion 
or  burstinff  of  the  tube.  After  many  experi- 
mente,  he  finally  adopted  the  following  method : 
An  amalgam  oonteining  3  p.0.  ol  barium  was 


prepared  according  to  Davy's  original  process, 
and  6  to  6  kilos  of  it  were  distiUea  in  an  atmo- 
sphere of  hydrogen  under  reduced  pressure  to 
such  a  point  as  to  obtein  an  amalgam  having  a 
close  grain  and  not  readily  oxidisaUe,  conteinmg 
about  10  p.a  barium.  About  half  a  kilo,  of 
it  was  then  placed  m  an  iron  boat  conteined  in  a 
large  porcelain  tube.  Over  the  boat  was  placed 
a  nickel  spiral  to  prevent  spurting  ana  loss. 
The  tube  was  then  heated  very  slowly  by  an 
electric  current  circuit  so  as  to  arrive  at  a  dull 
red  heat  in  about  four  hours,  a  vacuum  being 
maintained  in  the  tube.  The  amalgam  slowly 
loses  mercury  without  change  of  form,  and 
towards  900^*  it  suddenly  liquefies,  when  the 
current  is  turned  off  to  avoid  ebullition  and 
loss.  The  amalgam  so  obtained,  containing 
about  66  p.0.  barium,  has  a  ooarsely  faceted 
crystalline  structure,  and  quickly  oxidises  in 
air.  For  the  last  operation  it  is  placed  in  a 
nickel  boat  conteined  in  a  porcelain  tube  lined 
with  nickel  foil  The  latter  is  necessary  as 
when  the  barium  distils  towards  the  end  of  the 
operation  ite  corrosive  action  on  the  glass 
causes  rupture.  The  tube  is  mainteined  at 
900*  for  two  or  three  hours  under  diminished 
pressure,  keeping  the  ends  of  the  tube  suitebly 
cooled  ;  then  at  960^  for  one  hour  during  which 
time  there  is  a  considerable  loss  of  oarium. 
The  barium  so  obtained  is  kept  in  an  atmosphere 
of  dry  carbon  dioxide.  A  sample  obtained  by 
distilling  half  the  barium  had  the  composition 
Ba  98*36,  Hg  0-83,  Fe  0^.  In  repeated  experi- 
mente   Guntz  failed  to  obtein   barium   much 

Eurer  than  98  p.c  He,  however,  found  in  his 
kter  experimente  that  by  preparation  of  the 
hydride  a  much  purer  metal  could  be  obteined 
(Compt.  rend.  141,  1240).  Hie  method  is  a 
modification  of  the  earlier  experiment.  After 
the  preparation  of  the  metal  in  the  above  way 
pure  dry  hydrogen  ii  allowed  to  enter  l^e 
tube,  mainteinea  at  900*.  It  is  then  heated 
to  1200*,  just  below  the  fusion  point  of  the 
hydride ;  by  this  means  every  trace  of  mercury 
can  be  removed.  The  hydride  contained  in  a 
nickel  boat  is  then  placed  in  the  nickel-lined 
tube,  heated  in  a  vacuum  at  1200^,  whereby 
the  hydride  is  completely  decomposed  and  the 
volatilised  barium  is  condensed  on  a  polished 
steel  tube  cooled  by  circulating  water  placed 
inside  where  the  vapours  are  being  liberated. 
The  metel  so  obtained  assayed  99-6  p.o.  barium 
and  was  free  from  hydrogen. 

A  very  convenient  laboratory  method  for 
preparing  small  quantities  of  barium,  also  due 
to  Gunte,  is  to  heat  barium  oxide  with  one- tenth 
ite  weight  of  metallic  aluminium  at  1200^  in  a 
vacuum.  The  metal  condenses  in  the  cooler 
part  of  the  tube  and  assays  as  much  as  98*8  p.o. 
barium. 

Matignon  (Compt.  rend.  156,  1378)  has 
obtained  barium  by  heating  the  oxide  (3  mols.) 
with  silicon  (1  atom.)  in  a  vacuum,  in  a  steel 
tube,  at  1200*.  The  metel  distils  off  and  con- 
denses in  the  cooler  part  of  the  tube,  the  reaction 
being — 

3BaO+Si=BaSiOt+2Ba-37  cals. 
The  silicon  can  be  replaced  by  ferro-silicon  con- 
staining  95  p.c.  silicon. 

The  preparation  of  the  metal  by  electrolysis 
of  the  fused  oxide  or  chloride  does  not  appear  to 
be  attended  with  success ;  sub-salta  are  formed. 


640 


BARIUM. 


and  the  current  passes  without  further  action 
(Z.  Electroch.  9,  291:). 

Properties. — ^Barium  when  absolutely  pure 
is  a  silver- white  metal  with  a  density  of  3*78. 
It  is  slightly  harder  than  lead.  It  melts  at 
about  850°  and  commences  to  volatilise  at  950°. 
Barium  oxidises  rapidly  in  air,  yielding  princi- 
pally the  monoxide ;  the  powder  easily  takes 
fire  spontaneously.  Guntz  states  that  molten 
barium  attacked  all  the  metals  he  tried,  iron 
and  nickel  being  the  most  resistant.  Barium 
decomposes  water  and  alcohol  in  the  cold,  yield- 
ing in  the  latter  case  barium  ethoxide. 

Oxides  of  barium,  Three  oxides  of  barium 
are  known — barium  suboxide  Ba^O,  barium 
oxide  or  baryta  BaO,  and  barium  peroxide 
BaO,. 

Barium  suboxide  Ba-O  is  obtained,  according 
to  Guntz  (Compt.  rend.  143,  339),  by  heating 
the  protoxide  with  magnesium  or  barium  to  a 
temperature  of  1100°.  It  is  a  black  mass  which 
decomposes  water. 

Barium  oxide,  protoxide,  monoxide,  or 
baryta,  BaO,  is  the  oxide  formed  when  the  metal 
bums  in  air.  It  is  more  readily  obtained  by 
lieating  (1)  the  nitrate  or  (2)  the  carbonate  of 

barium. 

(1)  Barium    nitrate    heated    progressively, 

fuses,  then  decomposes  with  the  liberation  of 
nitric  fumes  and  much  frothing  leaving  a  porous 
mass  of  barium  oxide. 

(2)  The  carbonate  may  also  be  converted  into 
barium  oxide  by  exposing  it  to  the  strongest  heat 
of  a  forge  fire ;  but  the  last  traces  of  carbonic 
acid  are  only  expelled  with  difficulty.  However, 
at  an  ordinary  white  heat,  this  may  be  accom- 
plished by  mixing  the  carbonate  with  one-tenth 
of  its  weight  of  lampblack  or  charcoal  and 
making  into  a  thick  paste  with  oil  or  tar,  carbonic 
oxide  being  evolved,  thus : 

BaCO,+C=BaO+2CO. 

The  mixture  should  be  heated  in  an  earthen 
crucible  lined  with  lampblack  and  fitted  with 
a  tight  cover ;  on  the  large  scale  witherite  is 
thus  converted  into  baryta  for  use  in  separating 
crystallised  sugar  from  molasses.  In  a  second 
baryta-manufacturing  process  a  mixture  of  the 
carbonates  of  barium  and  calcium  is  ignited  in 
a  current  of  aqueous  vapour. 

(3)  On  the  small  scale,  baryta  may  be  easily 
obtained  by  heatinff  barium  iodate,  whjch  readily 
gives  up  all  its  io(une,  together  with  five-sixths 
of  its  oxygen,  without  fusing  or  frothing : 

Ba(IOa),=BaO-fI,0,. 

Barium  oxide  as  prepared  by  the  above 
methods  is  generally  a  greyish-white  friable 
mass  of  specific  gravity  4*7-^5*5.  Brtigclmann 
(Annalen,  [2]  4, 277),  by  heating  barium  nitrate  in 
a  porcelain  flask,  obtained  minute  crystals  of 
BaO  belonging  to  the  regular  system,  of  sp.gr. 
5*722.  He  found  later  that  by  heating  uie 
oxide  in  a  clay  or  graphite  crucible  he  obtained 
needles  belonging  to  the  hexagonal  system 
sp.gr.  6 '32,  but  if  heated  in  a  platinum  crucible 
the  oxide  is  obtained  in  cubic  forms,  8p.gr. 
5*74.  It  is  therefore  dimorphous  (Zeitsch. 
anaL  Chem.  29,  127).  It  Is  only  just  melted 
even  by  the  heat  of  the  oxyhydrogen  blow- 
pipe ;  but  in  the  electric  furnace  it  may  be 
readily  liquefied  and  volatilised.  The  liquid 
on    cooling  yields  a  crystalline  mass  (Moissan, 


Ann.  Chim.  Phvs.  [7]  A,  139);  it  is  a  non- 
conductor of  electricity,  but  in  presence  of 
mercury  may  be  electrolysed  into  barium  and 
oxygen.  BaO  is  strongly  alkaline,  caustic,  and 
poisonous.  Fluorine  attacks  it  in  the  ooM, 
liberating  oxyeen,  the  mass  becoming  incandes- 
cent. I^y  ohforine  has  little  or  no  action  on  the 
perfectly  anhydrous  baryta^  It  is  deoxidised 
by  potassium  at  a  red  heat,  and  slakes  with 
water,  forming  barium  hydrate  Ba(OH),  with 
such  energy  that  the  whole  mass  faleoomee 
inca.ndescent  provided  the  amount  of  water 
be  not  too  large.  It  rapidly  abeorbe  moistore 
from  the  air.  It  unites  with  methyl  and  ethyl 
alcohols,  forming  the  compounds  BaO,2CH40 
and  BaO,2C|H,0.  Heated  in  the  vapour  of 
carbon  disulphide,  it  forms  barium  carbonate 
and  barium  sulphide : 

3Ba04-C8,=BaCO,-f2BaS. 
It  dissolves  readily  in  dilute  nitric  and  hydro- 
chloric acids,  but  with  most  other  acids  forms 
insoluble  salts.  When  vapour  of  sulphuric  an- 
hydride is  passed  over  it,  heated  to  low  redness 
in  a  glass  tube,  formation  of  barium  sulphate 
BaS04  occurs  with  incandescence. 

Barium  peroxide  or  dioxide  BaO,  is  formed 
when  anhydrous  baryta  is  heated  to  a  dull  red 
heat  in  a  stream  of  oxygen  or  of  air  freed  from 
carbonic  acid.  Barium  hydroxide  may  be  similarly 
converted  into  the  peroxide,  but  less  readily,  as 
it  fuses  below  the  temperature  of  absorption  of 
oxygen ;  but  the  absorption  may  be  rendered 
rapid  by  mixing  the  hydroxide  with  lime  or 
magnesia  which  prevents  fusion  and  keeps  the 
mass  porous.  Peroxide  of  barium  may  also  be 
obtained  by  sprinkling  red-hot  bsiyta  with  four 
times  its  weight  of  powdered  pota.ssium  chlorate 
in  successive  small  portions ;  the  potassium 
chloride  simultaneously  formed  may  be  washed 
out  with  water,  leaving  the  peroxide  in  the  form 
of  a  hydrate. 

The  peroxide  obtained  by  these  means  is  not 
pure,  beinp  contaminated  with  a  little  uncon- 
verted barium  oxide,  iron,  silica,  and  other  sub- 
stances derived  from  the  preparing  vessels.  In 
order  to  purify  it  the  finely  powdered  crude  pro- 
duct is  gradually  added  to  an  excess  of  dilate 
hydrochloric  acid,  avoiding  any  considerable  rise 
of  temperature  ;  the  cru(&  substance  dissolves* 
forming  barium  chloride  and  peroxide  of  hydro- 
gen. The  solution  is  filtered  from  insoluble 
matters  and  treated  with  baryta  water  until  the 
silica  and  ferric  oxide,  together  with  a  little 
hydrated  barium  peroxide,  regenerated  by  action 
ot  the  peroxide  of  hydroeen  upon  the  banum 
hydroxide,  are  precipitated.  Tne  liquid  is  again 
filtered  and  then  supersaturated  with  baryta. 
By  this  means  the  whole  of  the  peroxide  of 
hydrogen  re^nerates  barium  peroxide,  which  is 

Precipitated  in  minute  prisms  or  lamins  of  the 
ydrate  BaO^fSHjO,  in  which  condition  the  per- 
oxide is  best  preserved,  and  is  a  suitable  form  foe 
use  in  the  preparation  of  peroxide  of  hydrogen. 
On  drying  at  130°  or  at  oramary  temperatures  in 
vacuo  it  is  converted  into  pure  anhydrous  barium 
peroxide. 

The  preparation  of  barium  peroxide  in  the 
wet  way  always  yields  the  octohydrate  when 
more  than  one  molecule  of  baryta  is  present  per 
molecule  of  HiO^.  Above  60°  it  is  formed,  what- 
ever tbe  composition  of  the  solution.  Below  40° 
the  di-peroxyhydrate  BaOt,2HgOa  is  obtained 


BARIUM. 


541 


from  solutions  containing  much  H.O^.  A 
compound  BaO,»H,0|  may  oe  obtained  between 
SO""  and  60°  (Zeitscb.  Anorg.  Ghem.  89,  406). 

Barium  peroxide  is  a  grey,  impalpable  powder, 
slightly  more  fusible  than  the  monoxide.  The 
temperature  of  dissociation  depends  upon  the 
pressure.  According  to  Le  Chatelier  (Compt. 
rend.  115,  6m4),  the  figures  are-as  follows  : — 

Temp.C.°  520  665  050  670  720  735  750  775  785  700 
Press,  mm.   20    25    65   80  210  260  840  510  620  670 

These  pressures  vary  according  to  the  degree  of 
decomposition  being  highest  at  the  commence- 
ment of  the  operation.  Brings  method  of 
preparing  oxygen  depends  upon  the  above 
physical  factors.  The  spongy  protoxide  of 
barium  prepared  as  indicated  above  is  placed  in 
thin  beds  in  iron  retorts  heated  by  special 
furnaces.  The  temperature  is  maintained  as 
constant  as  possible  between  500°  and  600°. 
Air  which  has  been  freed  from  moisture  and 
carbon  dioxide  by  passing  first  over  quicklime 
and  then  over  caustic  aoda,  is  forced  by  pumps 
through  the  retorts  whereby  the  BaO  is  con- 
verted to  BaOg.  The  residual  nitrogen  is 
allowed  to  escape  into  the  atmosphere.  When 
the  peroxidation  is  complete  a  set  of  valves 
places  the  retorts  in  connection  with  the  exhaust 
pumps,  the  reduction  of  pressure  causing  libera- 
tion of  oxygen.  The  first  portions  are  allowed 
to  escape  until  the  pressure  measures  65  cm. 
mercury,  another  set  of  valves  then  comes  into 
play  and  automatically  connects  the  retorts 
with  the  gasometer.  The  oxygen  obtained  is 
97  to  98  p.c.  pure.  Barium  peroxide  is  used 
in  the  preparation  of  hydrogen  peroxide  or 
dissolved  in  accidulated  water  as  a  bleaching 
agent. 

Peroxide  of  barium  is  decomposed  by  sul- 
phuretted hydrogen  at  ordinary  temperatures, 
and  when  heated  in  a  current  of  carbonlo  oxide 
it  bpcomos  white  hot.  It  becomes  incandescent 
when  heated  in  sulphur  dioxide.  When  treated 
with  strone  sulphuric  acid  at  a  temperature 
exceeding  70",  oxygen  is  given  off;  at  lower 
temperatures  the  oxygen  is  mixed  with  Ofone. 
When  the  peroxide  is  mixed  with  acidulated 
water  in  presence  of  oxide  of  silver,  peroxide 
of  manganese,  or  peroxide  of  lead,  oxygen 
18  evolved  both  from  the  peroxide  of  bairinm  and 
from  the  other  oxide.  A  small  quantity  of  a 
silver  compound  is  capable  of  decompc»ing  a 
Urge  quantity  of  barium  peroxide,  but  iocune 
de^mposes  an  exactly  equivalent  quantity : 

BaO,-M,=BaI,H-0,. 

The  amount  of  active  oxygen  in  BaO,  may 
be  determined  by  adding  a  known  quantity  of 
the  peroxide  to  pure  hydrochloric  acid,  then 
potassium  iodide  free  from  iodate  together  with 
excess  of  bicarbonate  of  soda,  and  titrating  the 
liberated  iodine  with  a  standard  solution  of 
sodium  thiosulphate.  It  may  also  be  estimated 
by  titrating  an  acidulated  solution  with  standard 
potassium  permanganate  (Bertrand,  BulL  8oo. 
chim.  [2]  33,  148). 

Barinm  hydroxide,  Hydrate  qf    Baryta^  or 
Cavstic  Baryta  Ba(0U)2  orBaO-HiO,  is  formed, 
with  great  evolution  of  boat,  when  water  is 
added  to  anhydrous  baryta  (b«rium  oxide) : 
BaO+H,0«=Ba(OH),. 

A  hot  concentrated  solution  of  equivalent 
quantities  of  barium  nitrate  and  sodium  or  po- 


tassium hydroxide  deposits,  on  cooling,  crystals 
of  barium  hydroxide.  Soda  is  usually  employed, 
of  sp.gr.  1  ■10-1*15,  and  the  crystals  obtained  are 
freed  Irom  mother  liquor  by  fining,  or  better, 
by  means  of  a  centrifugal  machine. 

Commercial  caustic  baryta  is  prepared  on 
the  large  scale  by  igniting  the  native  sulphate 
01  heavy  spar  with  coal  or  charcoal,  whereby  an 
impure  barium  sulphide  is  obtained,  and  heating 
this  is  earthenware  retorts  into  which  a  current 
of  moist  carbonic  acid  is  passed,  thus  converting 
it  into  carbonate : 

BaS+CO,+H,0=BaCO,+H,S. 
Superheated   steam    is   then    passed   over   the 
heated  carbonate,  when  the  following  decom- 
position takes  place : — 

BaCO,+H,0«Ba(OH),+CO,. 

According  to  R.  Heintz  (Chem.  Zcit.  1901, 
199),  only  iho  carbonate  is  used  to  any  extent. 
The  calcination  is  conducted  in  specially  con- 
structed furnaces  lined  with  basic  material 
and  heated  with  producer  gas.  The  product 
contains  95  p.c.  BaO.  The  same  author  reviews 
the  methods  that  have  been  suggested  for  the 
manufacture  of  baryta  from  barytes,  and  con- 
siders them  tooi  costly  for  the  production  of  a 
cheap  commercial  oxide. 

Marino  (Gazz.  chim.  ital.  43,  416)  has  shown 
that  the  reduction  of  barium  sulphate  to  sulphide 
is  effected  by  reducing  gases,  especially  water  gas, 
more  readily  than  with  the  use  of  coal,  the  reduc- 
tion occurring  at  525°-540°.  In  practice 
600°-C25°  is  used,  and  a  yield  of  95-98  p.o.  was 
obtained  in  an  experimental  furnace.  Baryta 
is  then  prepared  by  the  electrolysis  of  a  solution 
of  barium  sulphide  by  Brochet  and  Ransome's 
process,  a  diaphragm  of  high  resistenoe  being 
employed  in  all  cases.  The  best  results  are 
obtained  with  copper  electrodes  and  a  solution 
containing  20  p.c.  of  BaS.  The  barium  hydrate 
at  the  anode  increases  as  long  as  the  concentra- 
tion does  not  fall  below  5  p.c,  and  in  concen- 
trated solutions,  at  70°-80°  amounts,  after 
24  hours,  to  13  grms.  per  litre.  Formation  is 
due  to  interaction  of  hydroxyl  ions  with  the 
BaS. 

Caustic  baryta  crystallises  from  water  in 
laige,  transparent,  colourless,  quadratic  prisms 
capped  by  pyramids.  The  crystals  Ba(OH)|, 
8HjO  are  isomorphous  with  the  corresponding 
strontium  compound.  They  dissolve  in  20  parts 
of  water  at  15  ,  and  in  2  parts  of  boiling  water. 
The  aqueous  solution  known  as  baiyta  water  is 
highly  caustic  and  of  strong  alkaline  reaction, 
rapidly  becoming  covered  with  a  film  of  car- 
bonate owing  to  absorption  of  atmospheno  car- 
bonic acid ;  bence  it  ia  frequently  used  in  the 
determination  of  the  amount  of  carbonic  acid 
contained  in  the  air.  On  exixMure  to  air  the 
crystals  fall  to  a  white  powder,  with  loss  of 
seven  molecules  of  water.  De  Forcrand  (Compt. 
rend.  103,  59)  isolate  the  hydrate  Ba(OH)|,n,0 
by  allowing  the  compound  BaO,2CH,0+2H«0 
to  evaporate  over  sulphuric  acid  in  vacuo. 
H.  Lescoeur  (Compt.  rendL  96,  1578)  shows  that 
at  100®  Ba(OH)s,H,0  has  a  tension  of  dissocia- 
tion of  45  mm.,  and  that  this  hydrate  is  com- 
pletely converted  to  Ba(OH),  when  heated  to 
100°  in  vacuo.  LescoBur  also  proves  that  the 
dissociation  tension  of  Ba(0H)|,8H|0  is  213 
mm.  at  75°,  so  that  at  this  temperature  all  three 
hydrates   of   BaO   may   exist   simultaneously. 


542 


BABIUIL 


.Ba(0H)2,  when  heated  alone,  is  only  redaoed 
to  baryta  a  bove  a  red  heat ;  if  not  heated  above 
rednew,  it  re-formi»  on  cooling,  a  oryat^IIine 
mass  of  Ba(OH)„  bat  ^en  heated  in  a  onrrent 
of  air  it  takes  up  ozyj^en  and  is  oonverted  into 

geroxide  of  banum  with  loss  of  water;   when 
eated  in  a  oorrent  of  carbonic  acid  it  also  loses 
water  and  is  converted  into  barium  carbonate : 
Ba(OH),+0=BaO,+H,0. 
Ba(OH),+00,-»BaCO,+H,0. 
Baryta  has  until  recently  been  used  in  the 
processes  of  sugar-refining,  inasmuch  as  it  forms 
the  compound  CitHg^OiiBaO  with  cane-sugar, 
which,  when  treated  with  carbonic  acid  gas,  is 
decomposed  into  insoluble  barium  carbonate  and 
sugar,  nence  affording  a  means  of  separating  the 

Sure  sugar  from  the  molasses ;  but  as  strontium 
ydrate  acts  in  a  nmilar  manner,  and  is  not 
poisonous,  it  has  been  substituted  for  baryta  in 
sugar-refining. 

Hydnted  barium  peroxide.  SchSne  has 
shown  (Ber.  13,  803)  that  only  one  hydrate  of 
BaOa  exists,  containing  8  molecules  of  water, 
BaOs,8H,0.  This  hjSnte  is  precipitated  in 
crystalline  scales  vdien  peroxide  of  hydrogen  is 
aaded  to  concentrated  solutions  of  barium 
hydroxide.  It  is  slightly  soluble  in  cold  water,  but 
decomposes  in  boiUng  water,  forming  Ba(OH), 
and  evolving  oxygpu. 

Barium  snbenforide  BaQ  is  obtained  (Guntc, 
Bull.  Soc  chim.  [3]  20,  490)  when  equal  amounts 
of  BaCli  and  Ba  are  heated  together  in  t/acuo  at 
850°.  The  fragments  of  BaCl|  absorb  the  molten 
barium  without  change,  and  are  microcrystallina 
The  material  so  obtained  is  not  pure.  It  decom- 
poses water.  By  using  Na,  a  definite  compound 
NaClBaCl  can  be  obtamed.  BaCl  appears  to  be 
formed  when  electrolysing  fused  BaCl,. 

Barium  chloride  BaCit.  Crystallised  {terra 
ponderosa  aalUa)  BaCl|,2H|0.  fiarium  chloride 
may  be  prepared  either  from  witherite,  the 
native  cart)onate,  or  from  heavj^-spar,  the  native 
sulphate.  The  witherite  is  dissolved  in  dilute 
hydrochloric  acid  and  the  solution  allowed  to 
stand  some  time  in  contact  with  excess  of  the 
carbonate,  which  is  added  to  precipitate  iron  and 
other  foreign  metals  present  in  the  mineral; 
the  rapidity  of  precipitation  is  much  increased 
by  the  addition  of  a  little  baryta  water.  The 
filtered  liquid  is  then  neutralised  with  hydro- 
chloric acid,  and  the  salt  ciystallised  out  and 
purified  by  reorystallisation. 

Item  the  native  sulphate  barium  chloride 
may  be  prepared  in  two  ways : 

(1)  tfy  heating  the  sulphate  in  a  crucible  with 
powderea  coal  and  decomposing  a  filtered  solu- 
tion in  water  of  the  barium  sulphide  formed  with 
hydrochloric  acid :  BaS-|-2Ha=Baa,+H,S. 

Excess  of  hydrochloric  acid  is  added,  and 
the  liquid  boiled  till  free  from  sulphuretted 
hydrogen  ;  it  is  then  filtered,  cooled,  and  evapo- 
rated to  the  crystallising  point. 

(2)  Bv  heating  a  mixture  of  100  parts  finely 
powderea  heavy-spar,  40  parts  of  charcoal,  20 
parts  of  limestone,  and  50  parts  of  calcium 
chloride  to  a  red  heat  in  a  reverberatory  furnace, 
by  which  barium  chloride  and  calcium  sulphide 
are  formed.  The  mass  is  lixiviated  with  water, 
when  the  barium  chloride  is  dissolved  out, 
leaving  an  insoluble  calcium  oxysulphide  formed 
by  the  union  of  the  sulphide  with  the  oxide  of 
calcium  produced  by  ignition  of  the  limestone.) 


Commereial  l>ariuiii  chloride  generally  eoo- 
tains  small  quantities  of  strontium  and  calcium 
chlorides,  together  witii  traces  of  the  chlorides 
of  iron,  aluminium,  copper,  and  lead.  Washing 
the  crystals  with  alcohol  removes  both  the 
strontium  and  oalcium  chlorides,  whilst  calcium 
chloride  may  also  be  removed  by  digesting  with 
barium  oartionate  suspended  in  water,  whim  the 
calcium  chloride  becomes  converted  to  car- 
bonate, or  more  rapidly  by  adding  baryta  water 
and  passing  carbcmic  acid  gas  into  the  liquid. 
Digestion  with  barium  carbonate  also  precipi- 
tates the  sesquioxides  of  iron  and  ahimina. 
Lead  and  copper  may  best  be  removed  by  the 
addition  of  a  fittle  barium  sulphide. 

Barium  chloride  may  be  recovered  from 
mixtures  of  chlorides  of  the  alkalis  and  alkaline 
earths  by  treating  the  concentrated  liquor  with 
a  hot  saturated  sSution  of  nlt^  when  on  cooling 
a  mixture  of  barium  and  sodium  chlorides 
crystallises  out;  by  treating  a  cold  saturated 
solution  of  this  mixture  with  twice  its  volume  of 
hydrochloric  acid,  barium  cMoride  is  precipitated 
(Di^.  poly.  J.  250,  91). 

Barium  chloride  crystallises  from  aqueous 
solution  with  two  molecules  of  water  BaXJi^Kfi 
in  transparent*  colourless,  rhombic  tables; 
sp.gr.  2*66-3*05.  The  crystals  decrepitate 
when  heated.  They  have  an  unpleasant,  bitter, 
sharply  saline  taste,  exciting  nausea,  and  are 
very  poisonous. 

One  hundred  parts  of  water  at  0*  dissolve 
82*62  parts  of  anhydrous  barium  chloride,  and 
0*2711  part  for  every  desree  above  0*;  100 
parts  of  water  at  15*6*  dissolves  43*5,  and  at 
105  -5*  78  parts  of  the  crystallised  chloride.  One 
part  of  crystaUised  barium  chloride  at  18-1*  dis- 
solves in  2*257  parts  of  water  to  form  a  sdution 
of  sp.gr.  1*28251  (Earsten).  A  solution  satu- 
rated at  8**  has  a  sp.gr.  of  1*270  (Anthon). 

Barium  chloride  is  almost  insoluble  in  strong 
hydrochloric  acid,  so  that  it  is  precipitated  from 
its  solutions  by  hydrochloric  acid,  and  a  few 
drops  of  the  acid  reduces  the  solubiUty  consider- 
ably. Hot  absolute  alcohol  dissolves  only  ^^ 
part  of  the  crystals ;  but  according  to  Freeenibs, 
1  part  of  the  salt  dissolves  in  8108  parts  of 
alcohol  of  99*3  p.c.  at  14*^,  and  in  4857  parts  of 
the  same  alcohol  at  its  boiling  point. 

The  crystals  are  not  efflorescent,  but  give  up 
the  whole  of  their  water  at  100*,  leaving  a 
white  mass  of  the  anhydrous  salt,  which  melts 
at  a-  red  heat»  forming  a  translucent  mass  on 
cooling;  the  ciystflds  are  optically  biaxial  and 
positive.  Specific  gravity  of  the  anhydrous 
chloride  is  given  by  various  observers  as  3*70  to 
4*15.  Hans  Winter  (Diss.  Leipzig.  1913, 1)  gives 
the  following  constants,  in.p.  958%  spwgr.  3*789. 
When  heat^  in  a  current  of  steam  it  evolves 
hydrochloric  acid  below  its  fusing  point 

Calcium  and  barium  chlorides  form  the  double 
salt  CaCl,BaCla  (m.p.  63r),  but  no  mixed 
crystals.  Barium  and  strontium  chlorides  form 
a  complete  series  of  regular  (fi)  mixed  crystals, 
which  on  cooling  are  transformed  to  (a)  crystals 
(monoclinic).  The  two  series  correspond  with 
the  a  and  fi  forms  of  BaCl,,  which  coexist  in 
equilibrium  at  922*.  The  freezing-point  curve 
shows  a  minimum  at  847*,  at  which  point  30 
mols.  p.c.  BaClg  are  present.  The  double 
chlorides  2KCl,Sr01,  and  2KGl,BaClt  are 
isomorphous  and  rhombic 


BiRIUM. 


643 


A  concentrated  solution  of  barium  chloride  is 
decompoeed  by  Bodinm  or  potaarinm  nitrate, 
forming  barium  nitrate  and  a  chloride  of  the 
alkali-metaL  With  glycocol  CHa(NHa)-OOOH 
it  forms  a  crystalline  compound,  and  also  acts 
npon  blood  as  a  preventive  of  putrefaction  and 
coagulation. 

%arium  chloride  is  extensively  used  as  a  re- 
agent, especially  for  the  detection  and  estimation 
of  sulphuric  acid.  It  is  also  used  for  the  prepara- 
tion of  artificial  sulphate  or  '  permanent  wtdte/ 
and  for  preventing  the  incrustation  of  steam 
boilers  by  decomposing  the  gypsum  of  hard 
waters. 

Barinm  oxyehloride.  Andrtf  (Ck>mpt.  rend. 
93,  68)  obtained  an  ozychloride  of  barium  by 
adding  60  grams  of  Ba(OH)fl  to  200  grams  of 
crystallised  barium  chloride,  and  boUing  the 
mixture  with  500  grams  of  water,  filtering,  and 
allowing  to  cool,  when  nacreous  lamellte,  to 
which  he  ascribed  the  formula  BaCl|'BaO,5HsO, 
separated  out  (Compt.  rend.  08,  672).  Beck- 
mann  (J.  pr.  Ghem.  [2]  27,  126)  also  obtained 
nacreous  plates  by  similar  means  to  which  he 

gave  the  formula  BaCI(OH),2HaO.  These  plates 
Me  f  ths  of  their  water  at  120^  and  the  remaining 
fifth  at  the  fusing-point  by  prolonged  heating 
in  a  stream  of  hy^ogen.  This  oxychloride  is 
readily  decomposed  by  water  or  alcohol. 

Barlmn  ehlorite  Ba(C10a)|  may  be  obtained 
absolutely  free  from  chloriae  by  the  action  of  a 
mixture  of  chlorine  dioxide  and  carbon  dioxide 
free  from  chlorine  on  barium  peroxide  suspended 
in  hydrogen  peroxide.  The  decomposition  of 
barium  chlorite  takes  place  according  to  the 
equation — 

Ba(C10,),=:BaCl,+20,+48-6  cals. 

From  this  follows  the  equation — 

Ba+CIa+20a=Ba(ClOa)a(8oUd)+148  cals. 
and 

BaCIgH-20,=Ba(aO,),-48-6  cals. 

Ba(C10,),+0,=Ba(C10,),+22-8  cals. 

Ba(aO,),+O,=Ba(ClO4)|-f-30-2  cals. 
Consequently  in  compounds  containing  chlorine 
in  different  deerees  ox  oxidation  the  formation  is 
the  lees  endothermic  and  the  more  exothermic 
the  higher  the  degree  of  oxidation  (Gazz.  chim. 
ital.  46, 161). 

Barium  ehlorate  Ba(aO,)a.  Diy  Ba(OH)a 
does  not  absorb  chlorine,  but  in  presence  of 
water  it  rapidly  takes  it  up,  forming  first  hypo- 
chlorite and  chloride,  the  former  of  which  breaks 
up  into  chlorate  and  chloride 

6BaO+6Clg=6BaClt+Ba(C10,), 

(KonigelWiesberg,  Ber.  12,  346). 

As  it  is  difficult  to  separate  from  the  chloride, 
the  chlorate  is  best  prepared  by  neutralising  a 
solution  of  chloric  acid  with  buium  carbonate 
and  evaporating  to  the  oiystHlUsing  point.  It 
crystallises  in  colourless  monoclinic  prisms  with 
1  molecule  of  water,  soluble  in  4  parts  of  cold  and 
less  than  1  part  of  boiling  water. 

Barium  chlorate  is  also  slightlv  soluble  in 
alc<Aol,  and  the  alcoholic  solution  bums  with  a 
green  flame. 

If  strongly  heated  fused  barium  chlorate  be 
plunped  into  a  jar  of  coal  gas,  a  brilliant  com- 
bustion of  the  carbon  and  hydrogen  contained  in 
the  coal  gas  occurs  at  the  expense  of  the  oxygen 
of  the  chlorate. 


Barimii  parohlorate  Ba(aO^).,4HaO  is  readily 
formed  by  neutralifling  i)erchIoric  acid  witn 
barium  hydrate  or  carbonate.  It  crystalUses 
from  the  solution  in  long  deliquescent  prisms 
very  soluble  in  water. 

Barium  bromide  BaBrt.  Crystallised 
BaBr.,2HaO. 
This  salt  it  prepared  by  saturating  baryta 
water  or  barium  carbonate  or  sulphide  with 
hydrobromic  acid;  or  by  decomposing  the 
sulphide  with  free  bromine,  sulphur  being  pre- 
cipitated. 

The  most  eonvenient  method  is  to  bring  to- 

rther  under  water  12*6  parts  of  bromine  Mind 
part  of  amoff^iws  ^oaphorus,  by  which  a 
solution  of  hycuobromic  and  phosphoric  acids 
is  formed,  which  ia  neutraUsed  witnbarkim  car- 
bonate rendered  alkaline  by  baryta  water.  The 
insoluble  barium  phosphate  may  then  be  filtered 
off  and  the  bromide  obtained  by  evaporation  and 
crystallisation. 

Barium  bromide  is  very  soluble  in  water,  and 
enrstaUises  with  difficulty;  it  is  isomorphous 
with  the  chloride,  but  unlike  the  latter  udt  is 
soluble  in  strong  alcohoL  It  loses  one  molecule 
of  water  at  75*,  and  the  second  at  120*  (Beck- 
mann,  J.  pr.  Chem.  [2]  27,  126),  m.p.  of  anhy- 
drous salt  847''. 

Barium  oxyhromldes.  Two  oxybromides 
have  been  prepared  by  Beckmana  (I.e.). 

BaBr(0H),2H|0  resembles  the  correspond- 
ing oxychloride.  BaBr(OH)  ,311,0  was  obtained 
by  addingalcohol  to  mixed  solutions  of  BaBr, 
and  Ba(()H),. 

Barinm  Iodide  Bal,.  Anhydrous,  sp.gr.  4-91 7, 
it  forms  several  hydrates  with  7,6,2,1  molecules 
of  water.  Barium  iodide  is  formed  when 
hydriodic  acid  gas  is  passed  over  bar3rta  at  a 
red  heat,  a  violent  action  occurring  attended 
with  inoandescence.  It  is  ^nerally  prepared 
by  mixing  barium  monosulphide  with  a  saturated 
solution  of  iodine  in  alcohol  as  long  fts  sulphur 
i3  precipitated;  the  filtrate  is  then  boiled 
rapidly  to  near  dryness,  redissolved  in  a  little 
water  and  again  evaporated,  this  time  to  dry- 
ness,  preventing  the  access  of  air  as  much  ai 
possible  by  perrorming  the  operation  in  a  glass 
Dolt-head.  On  redlssolving  the  mass  in  hot 
water  and  allowing  to  cool,  slender  needles 
separate  out  of  the  composition  BaI,,7HaO 
(Croft,  Gazz.  chim.  ital.  1866,  126;  Thomsen, 
Ber.  10,  1343). 

These  crystals  are  very  deliquescent  and 
readily  soluble  in  alcohol.  They  lose  6  molecules 
of  water  at  126°,  and  the  remainder  at  160'' 
(Beckmann,  J.  pr.  Chem. '[2]  27,  126).  They 
decompose  slowly  at  ordinary  temperatures,  ana 
quickly  when  warmed,  giving  off  violet  vapours 
of  iodine.  Commeroiaf  banum  iodide  crystal- 
lises at  the  ordinary  temperature  in  laige  hexa- 
gonal prisms,  apparently  isomorphous  with 
SnCl|,6U,0.  They  melt  in  their  water  of 
crystallisation  at  267''  (Centr.  Min.  1918, 106). 

The  double  iodide  of  barium  and  meroury 
has  a  sp.gr.  of  3  '688  higher  than  Ahat  of  Thoulet  s 
solution,  and  may  be  of  use  for  petrographical 
purposes  (Rohrbaoh,  Jahrb.  Min.  1883,  2, 
tfem.  186). 

Bariom  oiytodlda*  Beckmann  (J.  pr.  Ghem. 
[2]  27,  120)  prepared  an  ozyiodide  of  barium 
of  the  formula  BaI(0H),4H,0  which  crystallises 
in  short  thick  needles. 


M4 


BARIUM 


Buinm  iodate  Ba(IOt)i  is  largely  used  for 
the  preparation  of  iodic  acid,  and  is  obtained  m 
a  wlute  granular  precipitate  by  adding  potaarinm 
iodate  to  barium  chloride. 

It  is  soluble  in  3000  parts  of  cold  and  600 
parte  of  boiling  water.  It  dissolves  in  hot  nitric 
acid,  and  crystallises  out  on  cooling  in  bright, 
glittering,  monoclinic  prisms  isomorphous  with 
the  chlorate.  Hydrochloric  acid  dissolves  it 
with  evolution  of  chlorine. 

Barium  periodate.  By  passing  iodine  vapour 
in  a  current  of  dry  air  over  heated  oxide  of 
barium  a  basic  periodate  of  the  formula  Ba,IsOif 
or  Ba(I04)t'4BaO  is  formed.  The  same  ha^ 
'  periodate  is  formed  when  bsrium  iodate  i« 
heated  to  a  high  temperature : 

6Ba(IO,),=Ba5T,Oi,+4I,+90, 

or  on  heating  barium  iodide  in  a  current  of  air 
until  no  more  iodine  is  given  off : 

6BaI,-|-60,=BaJ,Oi,4-4T,. 

Hence  Sugiura  and  Cross  (J.  Chem.  Soc.  1879, 
118)  conclude  that  BagliOia  is  the  most  stable 
combination  of  barium,  iodine,  and  oxygen. 

Barium  fluoride  BaF,  (m.p.  1289^),  is  ob- 
tained by  neutralising  hydrofluoric  acid  with 
barium  hydroxide  or  recently  precipitated 
carbonate ;  or  by  precipitating  a  solution  of 
barium  nitrate  with  sodium  or  potassium  fluoride. 
It  forms  a  white,  granular,  crystalline  powder, 
sparingly  soluble  in  water,  but  readily  soluble 
in  nitric,  hydrochloric,  or  hydrofluoric  acids. 
It  ciystallises  in  the  cubic  system. 

It  combines  with  fluorides  of  silicon  and 
boron,  forming  the  compounds  BaFa*2SiF4 
barium  silicofluoride  and  BaF,'2BF,.  The 
former  is  precipitated  by  adding  hydrofluosilicic 
acid  to  soluble  barium  salts  as  a  crystalline 
precipitate  totally  insoluble  in  alcohol,  and 
serves  as  a  means  of  separating  barium  from 
strontium  and  calcium,  which  are  not  precipi- 
tated by  hydrofluosilicic  acid. 

Barium  fluoride  forms  a  crystalline  compound 
with  the  chloride  of  barium  BaCl,*BaF|  when  a 
solution  of  barium  chloride  is  mixed  with  one  of 
sodium  or  potassium  fluoride  ;  this  double  com- 
pound is  more  stable  than  the  fluoride  itself,  and 
remains  as  a  granular  mass  on  evaporation  of 
the  solution.  The  crystals  are  tetragonal  in 
habit,  and  optically  negative,  m.p.  1008*^, 
sp.gr.«  5*931. 

Barium  earblde  BaC,  was  first  obtained  by 
Maquenne  (Ann.  Chim.  Phys.  (6)  28,  269)  by 
heating  a  mixture  of  the  carbonate  and  carbon 
with  magnesium  or  by  the  action  of  carbon  on 
the  ama^am  in  an  atmosphere  of  hydrogen  at 
a  red  heat.  Moissan  (Compt.  rend.  118,  683) 
obtained  it  in  a  pure  crystalline  condition  by 
heating  a  mixture  of  the  carbonate  or  the  oxide 
with  carbon  in  an  electric  furnace.  Its  specific 
gravity  is  3*75,  and  it  possesses  properties 
similar  to  CaCf,  but  is  more  fusible. 

Barium  carbonate  BaCO,.  The  native  car- 
bonate was  first  noticed  to  occur  at  Leadhills  in 
Scotland,  in  1783,  by  Withering,  and  hence 
received  the  name  wiiheriU,  It  is  found  in 
maaiy  places  in  England,  specially  fine  crystals 
being  met  with  at  Fallowfield  in  Northumber- 
land :  it  is  ako  found  in  Silesia,  Hungary, 
Styria,  Russia,  South  America.  Witherite 
crystallises  in  the  rhombic  system  isomorphous 


with  aragonite.  It  occurs  also  in  globular, 
tuberose,  and  botryoidal  forms ;  more  froquently 
massive.    Sp.gr.  4-29-4*35  ;   hardness  3-3*75. 

Knop  (Landw.  Versuchs-Stat.  17,  65)  found 
0*02  p.c.  of  barium  carbonate  in  Nile  mud 
from  Minich  and  Achmin;  and  Dworzack 
(Landw.  Versuchs-Stat.  17,  65)  found  baryta  in 
the  ash  of  the  wheat  grown  thereon.  Alsloniie. 
(BaCa)COs  contains  barium  and  calcium  in 
varying  proportions,  and  is  isomorphous  with 
witherite.  Baryto-caldte  BaCOj-f-CaCO,  crys- 
tallises in  the  monoclinic  system. 

Boeke  (Jahrb.  Min.  9-10)  shows  by  heating 
barium  carbonate  under  pressure  of  carbon- 
dioxide,  that  it  undergoes  two  reversible  trans- 
formations. At  811°  the  ^  form  (witherite, 
orthorhombio  and  pseudo-hexagonal)  passes 
to  the  fi  form  (hexagonal),  and  at  982°  to  the 
a  form  (cubic),  m.p.  about  1740°.  The  system 
barium  carbonate-calcium  carbonate  (repre- 
sented by  the  minerals  alstonite  and  baryto- 
calcite)  give  iso-dimorphous  mixed  crystals  with 
a  eutectic  at  1139°  and  52|  mol.  p.c.  CaCO,. 
Up  to  30  moL  p.c.  CaCO^  the  orthorhombio 
alstonite  is  the  stable  form,  but  with  more 
calcium  carbonate,  this  is  replaced  by  trigonal 
baiyto-calcite.  Monoclinic  baryto-calcite  is  not 
present  in  the  fusions. 

Barium  carbonate  is  rapidly  formed  when 
baryta,  hydrated  or  anhydrous,  is  exposed  to 
the  atmosphere.  When  BaO  is  heated  in  CO, 
it  absorbs  the  gas,  becoming  incandescent ;  the 
basic  carbonate  being  formed  (Raoult,  Compt. 
rend.  92,  1,  110). 

It  is  readily  prepared  by  precipitating 
aqueous  solutions  of  the  nitrate  or  chloride  with 
ammonium  carbonate,  filtering,  and  washing 
with  hot  water ;  or  by  igniting  a  mixture  of  10 
parte  powdered  heavy -spar,  2  parte  charcoal,  and 
5  parte  pearl  ash  (potassium  carbonate).  Potas- 
sium sulphide  and  barium  carbonate  are  obteined 
and  may  be  separated  by  water.  The  impure 
carbonate  thus  produced  may  be  used  to  prepare 
other  salto  of  barium,  but  these  salte  will  contein 
iron. 

Artificial  barium  carbonate  is  a  dense  soft 
white  powder,  poisonous,  and  hence  used  for 
destroying  rats.  It  is  very  sparingly  soluble  in 
water,  slightly  soluble  in  water  containing 
carbonic  acid,  owing  to  the  formation  of  an  acid 
carbonate  which  is  steble  only  in  solution.  It 
dissolves  readily  in  ammonium  chloride,  nitrate, 
and  succinate,  and  when  boiled  with  ammonium 
chloride  is  totolly  decomposed,  forming  ammon- 
nium  carbonate  and  barium  chloride. 

The  solubility  of  BaCOg  in  water  has  been 
determined  by  Missenberger  (Zeitschr.  physikal. 
Chem.  88,  257),  and  also  in  water  conteining 
small  quantities  of  sodium  ■  hydroxide,  which 
represses  the  hydrolysis  and  so  furnishes  a  lower 
and  more  accurate  value  for  the  solubility.  The 
minimum  solubility  is  found  in  aqueous  solutions 
conteining  1  '25  x  10~^  mols.  of  sodium  hydroxide. 
The  following  values  were  obteined  (1)  for  pure 
water  at  13°.  1  62  X  10-»;  1 8°,  1  72  X  10-» ; 
22°,  1-83  X  10-»  ;  27°,  1*96  X  lO-«  ;  33°,  2*14  X 
10-« ;  37°,  2*28  X  10-«  mols.  per  litre,  and  (2) 
true  values  calculated  from  experimental  reauite 
in  faintly  alkaline  solutions  at  14°,  4*32  X 10-^ ; 
18°,  4*57x10-*;  23°,  4*89  XlO-*;  27°,  6*22  X 
lO-« ;  32°,  5*69  X 10-*  ;  38°,  6*27  X  10~«  gram 
mol.  per  litre. 


BARIUM. 


645 


It  is  not  deoomposed  at  a  stiong  red  heat, 
but  at  1361®  it  fuses  with  loss  of  carbon  dioxide  ; 
the  tension  of  COf  emitted  at  1100®  is  20  mm. ; 
at  1600®  dissociation  is  complete.  The  decom- 
position is  much  more  easily  effected  in  presence 
of  carbon,  being  complete  at  1450®.'  It  is  de- 
composed by  steam  at  a  red  heat,  and  very 
easily  if  mixed  with  an  equal  weight  of  chalk  or 
slaked  lime. 

The  artificial  carbonate  is  of  considerable 
use  in  chemical  analysis. 

Barium  nitride  Ba,N,.  Maquenne  (Bull 
Soc.  chim.  [3]  7, 368)  obtained  this  compound  by 
passing  nitrogen  into  a  tube  containing  a  25  p.c. 
amalgam  at  a^  red  heat.  Gunts  and  Mentrel 
(tbid,  (3)  29,  681)  obtained  it  by  heating  barium 
ammonium  at  430®.  So  obtained  it  is  a  light 
porous  material  of  a  canary-yellow  colour.  It 
decomposes  water  in  the  cola,  giving  ammonia 
and  Ba(OH)a. 

The  pure  nitride  and  hydride  are  readily 
obtained  by  heating  the  metal  in  the  respective 

gases.  When  the  nitride  is  heated  in  a  purrent  of 
ydrogen  a  compound  having  the  formula 
Ba^NaH^  is  formed,  but  the  product  is  impure 
since  the  compound  reacts  even  at  relatively  low 
temperatures  with  hydrogen  according  to  the 
equation 

Bi,N,H4-fH,=3BaH,+N, 

When  hydrogen  is  passed  over  the  heated  impure 
nitride  ammonia  is  formed.  BaH,  which  is 
thereby  produced  is  readily  transformed  back 
to  the  nitride  by  the  action  of  nitrogen,  so  that 
a  process  is  given  for  the  fixation  of  nitrogen 
(Monatsh.  34,  16a5). 

Barlnm  ammonium  is  formed  by  the  action 
of  ammonia  gas  on  barium  or  barium  amalgam 
below  28®  ;  but  it  is  best  prepared  by  dissolving 
barium  in  dry  liauid  ammonia  at  —50®,  when 
it  forms  a  dark- blue  oily  liquid  immiscible  with 
the  liquid  ammonia.  The  compound  is  some- 
what indefinite,  but  a  body  having  the  formula 
Ba(NHs)g  appeara  to  exist. 

Barium  amide  Ba(KHt)t  is  obtained  by 
heating  barium  ammonium  to  60®  or  by  passing 
ammonia  over  barium  at  280®  C. 

When  a  barium  salt  and  excess  of  potassa- 
mide  are  allowed  to  interact  in  liqtiid  ammonia 
solution  a  white  insoluble  precipitate  of  potassium 
ammonobariate  BaNK,2NHs,  or  Ba(NB,)„ 
KNHa,  is  produced.  The  strontium  and 
calcium  salts  may  be  prepared  in  the  same  way 
(J.  Amer.  Chem.  Soc.  37,  2205). 

Barium  nitrite  Ba(NOa).,HaO  is  prepared 
by  heating  the  nitrate,  dissolving  in  water,  and 
precipitating  any  baryta  formea  by  passing  a 
stream  of  carbon  dioxide  through  tiie  solution, 
adding  alcohol  to  the  filtrate  to  precipitate 
the  unreduced  nitrate,  and  evaporating  to 
the  crystallising  point  Or  by  passing  nitrous 
vapoura  into  oaryta  water,  evaporating  to 
dryness,  digesting  in  a  small  quantity  of  water 
(not  sufficient  to  oUssolve  the  nitrate)  and  crystal- 
lising. It  is  most  readily  prepared  pure  by 
addmg  barium  chloride  to  a  boiling  solution  of 
silver  nitrite,  filtering  off  the  silver  chloride,  and 
evaporating. 

It  is  permanent  in  the  air,  readily  soluble  in 
water  or  alcohol,  and  crystallises  in  colourless 
prisms,  either  needle-shaped  or,  according  to 
Fischer,  thick  short  prisms  of  71}®. 

Vol.  I.— r. 


Barium  nitrate  Ba(NOa),.  A  native  barium 
nitrate  has  been  discovered  in  Chile  in  the  form 
of  colourless  octahedra,  occasionally  twinned 
like  spinel  (Groth,  Jahrb.  Min.  1883,  1,  Ref.  14). 

Barium  nitrate  is  prepared  on  the  laigo  scale 
either  by  dissolving  the  native  carbonate 
(witherite)  or  the  crude  sulphide  in  dilute  nitric 
acid,  or  bv  mixing  hot  saturated  solutions  of 
barium  chloride  and  sodium  nitrate.  On  cool- 
ing, the  larger  portion  of  the  barium  nitrate 
crystallises  out,  and  the  evaporation  of  the 
mother  liquors  yields  the  remaining  portion. 

Barium  nitrate  crystallises  in  lustrous,  colour- 
less, regular  octahedra,  frequently  modified 
by  faces  of  the  cube,  of  sp.gr.  3'2.  The  crystals 
are  permanent  in  the  air,  decrepitating  when 
heated,  and  melting  at  595-53®  (Camelley  597®). 
At  a  red  heat  the  salt  decomposes,  evolving 
oxygen,  nitroffen,  and  nitrogen  peroxide,  and 
leaving  a  residue  of  pure  ba^ta.  It  detonates 
slightly  with  combustible  bodies,  and  decomposes 
with  a  yellowish  light  when  thrown  upon  the 
fire.  It  is  largely  used  in  pyrotechny  for  giving 
green-coloured  lights,  especially  for  the  prepara- 
tion of  ^reen  fire ;  and  for  the  manufacture  of 
s<unfrag%n,  au  explosive  mixture  of  76  parts  of 
barium  nitrate,  2  parts  of  nitre,  and  22  parts 
of  chareoaL 

It  dissolves  in  water,  producing  a  slight 
depression  of  temperature ;  100  parts  of  water 
dissolve  5*2  parts  of  barium  nitrate  at  0®,  9*2  at 
20®,  171  at  50®,  and  322  at  100®.  It  is  less 
soluble  in  dilute  nitric  acid;  hence  a  second 
crop  of  crystals  may  be  obtained  from  cooled 
saturated  solutions  on  addition  of  i^  little  nitric 
acid.  It  is  quite  insoluble  in  concentrated  nitric 
acid  and  in  alcohoL 

Hirzel  (Zeitsch.  f.  Pharm.  1854,  49)  obtained 
a  hydrate  Ba(NO()t,2HgO  from  a  solution  cooled 
below  12®.  Berry  (Chem.  News,  44,  190),  by 
saturaUng  the  same  water  with  barium  and 
strontium  nitrates,  introducing  a  crystal  of 
Sr(NOs)a,4HaO,  and  evaporating  over  sulphuric 
acid  in  vacuo,  obtained  crystals  containing  17  p.c. 
of  a  hydrated  barium  nitrate  isomorphous  with 
the  strontium  compound.     On  account  of  the 

?;rBat  electro  affinitv  of  nitrion  (nitrate  ion),  the 
ormation  of  double  nitrates  is  found  to  t>ccur 
in  few  cases,  and  with  one  exception  (the  double 
nitrate  of  barium  and  potassium)  are  formed  only 
when  one  of  the  metals  has  a  valencv  greater 
than  2.  The  unexpected  formation  of  the  double 
nitrate  of  potassium  and  barium  was  first 
observed  by  Wallbridge  (Amer.  Chem.  J.  30, 
154),  whose  analysis  showed  it  to  be  anhydrous 
and  to  have  the  formula  2KN0„Ba(N0,)a. 
Foote  showed  (Amer.  Chem.  J.  32,  251)  that  the 
double  salt  can  form  at  25®  under  a  moderately 
wide  range  of  conditions,  as,  for  example,  from 
solutions  containing  15  to  27  p.c.  KSO^  and 
from  6  to  2  p.c.  Bi^NOa)f  The  salt  cannot  bo 
recrystaUiseoL  Only  one  well-defined  basic 
nitrate  BagNiO^  is  known,  and  this  forms  several 
hydrates. 

Barium  monoiulphide  BaS  is  obtained  in  a 
pure  state  by  passing  sulphuretted  hydrogen 
over  heated  baryta  as  long  as  water  is  formed. 
Veley  (ChenL  Soc.  Trans.  1886,  369)  prepared 
pure  crystals  of  the  hydrate  of  barium  hydroxide 
Ba(OH)„8HtO,  and  heated  them  at  80®  in  a 
current  of  hydrogen  until  they  attained  the 
constant  composition   Ba(OH^^,HlO,   when   a 

2s 


646 


BABIUAL 


stream  of  sulphuretted  hydrogen  was  passed 
oyer  them,  yielding  pure  oaS  and  water : 

Ba(OH),^,0+HaS=BaS+3H.O 

Tt  may  also  be  prepared  by  passing  carbon 
disulphide  over  red-hot  baryta,  or  by  reducing 
powdered  barium  sulphate  in  a  stream  ox 
nydn^en. 

On  the  manufacturing  scale  it  is  prepared  by 
roasting  100  parts  of  heavy-spar  with  20  parts  of 
coal  slack  or  charcoal  If  charcoal  is  used,  a 
thorough  mixture  must  be  effected,  as  the 
reaction  is  otherwise  very  imperfect,  owing  to  the 
non-fusibility  of  the  mass.  If  the  slack  of 
bituminous  coal  is  used,  the  *  caking  '  supplies  a 
carbonaceous  material  which  readily  permeates 
the  mass  and  ensures  complete  reduction.  The 
admixture  of  resin,  oil,  or  sawdust  is  also  advan- 
tageous, and  the  asphalt  of  gasworks  is  a 
capita]  reducing  material,  as  the  hydrogen  con- 
tained in  it  prevents  the  formation  of  poly- 
sulphides  of  iMirinm.  The  mass  thus  obtained 
contains  excess  of  carbon  and  some  undecom- 
posed  sulphate,  but  the  barium  sulphide  may  be 
extracted  by  treating  with  hot  water. 

Another  method  is  to  heat  a  mixture  of  100 
parte  heavy -spar.  200  of  common  salt,  and  15 
parts  charcoal  powder  in  a  reverberatory  furnace, 
the  salt  being  added  to  assist  fusion. 

Barium  sulphide  forms  a  white  mass  of 
hepatic  odour  and  alkaline  taste,  soluble  in  water, 
forming  a  mixture  of  hydrate  and  sulphydrate : 

2BaS-f-2H,0=Ba(SH),-fBa(OH), 

When  exposed  to  the  air  it  becomes  converted 
into  carbonate  with  evolution  of  sulphuretted 
hydrogen,  owing  to  absorption  of  moisture  and 
carbonic  acid.  When  heated  to  redness  in  pre- 
sence of  aqueous  vspour,  it  is  converted  into 
barium  sulphate  with  elimination  of  hydrogen. 
It  is  decomposed  by  hydrochloric  and  nitric 
acids  with  formation  of  the  chloride  and  nitrate 
and  elimination  of  sulphuretted  hydrogen. 
Chlorine,  bromine,  and  iooine  decompose  it  wth 
formation  of  chloride,  bromide,  and  iodide,  and 
deposition  of  sulphur. 

The  phosphorescent  material  known  as 
*  Bolognian  phosphorus  *  is  a  sulphide  of  barium 
obtained  by  heating  5  parts  of  precipitated 
barium  sulphate  with  1  part  of  powdered  char- 
coal over  a  gas  flame  for  half  an  nour,  and  then 
heating  for  ten  minutes  over  the  blowpipe ;  it 
must  he  sealed  up  while  still  hot  in  glass  tubes. 
After  exposure  to  the  sun's  rays,  or  to  any  light 
rich  in  ultra-violet  rays  such  as  that  emitted  by 
burning  magnesium  wire  or  the  electric  arc,  it 
phosphoresces  in  the  dark  with  a  brilliant 
orange-coloiured  light.  Sulphides  of  barium, 
strontium,  and  calcium  are  now  manufactured 
for  the  preparation  of  luminous  paints  which  are 
used  for  coating  dock-faces,  match-boxes,  &o 
Their  surfaces  are  protected  from  moisture  by  a 
tliin  coating  of  vaniish.  Good  Bolognian  stones 
are  obtained  (J.  pr.  Chem.  iL  82,  193)  from  a 
mixture  of  strontium-  carbonate  (20  grams), 
sulphur  (3  grams),  lithium  carbonate  (0'5  gram), 
thorium  nitrate  (1  c.c.  of  0'5  p.c.  alcoholic 
solution),  or  barium  carbonate  may  be  sub- 
stituted for  strontium  carbonate  and  (0*3  gram) 
rubidium  carbonate  instead  of  thorium  nitrate. 
The  phosphorescence  is  more  intente  if  one  half 
of  the  alkaline  earth  carbonate  is  replaced  by  the 


corresponding  hydroxide.  Stcmes  exceeding  any 
others  previously  made  in  the  intensity  and 
duration  of  the  phosphorescence  have  been 
prepared  by  the  ignition  for  {  hour  in  a  Rdssler 
furnace  of  the  following  mixture :  calcium  oxide 
(10  grams),  strontium  carbonate  (10  grams), 
barium  carbonate  (10  grams),  magnesium  oxide 
(10  grams),  sulphur  (6  grams),  potassium  sul- 
phate (1  gram),  sodium  sulphate  (1  gram), 
lithium  carbonate  (2  grams),  starch  (2  grams), 
bismuth  nitrate  (2  c.c  of  0*5  p.c.  solution),  and 
thallium  sulphate  (2  c.c  of  0*5  p.c.  solution). 
The  stones  exhibit  a  pale  blue  phosphoiesoenoe. 
When  the  ignition  is  prolonged  to  two  hours  the 
phosphorescence  is  very  intense'  and  gremish- 
yellow.  After  three  hours*  ignition  the  stones  are 
no  longer  luminous.  The  finest  green  phos- 
phorescence is  produced  by  ignition  for  }  hour 
of  the  following  mixture:  calcium  oxide 
(10  grams),  strontium  oxide  (10  grams),  sulphur 
(3  grams),  potassium  sulphate  (0*5  gram), 
sodium  sulphate  (0*5  gram),  lithium  carbonate 
(1  gram),  starch  (1  gram),  bismuth  nitrate  (1  cc.), 
rubidium  nitrate  (1  cc.  0*5  p.c  solution). 
Barium  sulphide  is  now  largely  useci  in  the  manu- 
facture  of  lithophone  by  adoinff  it  dissolved  in 
water  to  a  solution  of  zinc  siuphate.  Mutual 
precipitation  takes  place,  and  the  >white  powder 
formed,  oonsiBting  of  zinc  sulphide  and  baiinm 
sulphate,  is  used  as  a  rubber  filler  and  pigment. 

When  a  solution  of  5  parts  of  barium  sul- 
phide is  boiled  with  1  part  of  sulphur,  and  the 
solution  evaporated  over  sulphuric  acid  tn 
vacuo,  colourless  six-sided  tranqMurent  tables  of 
BaS,6H,0  are  deposited,  which  are  decomposed 
by  a  small  quantity  of  water,  forming  barium 
hydrosulphide  which  dissolves,  and  barium 
hydroxide  which  remains  behind. 

Barium  hydrosulphide  Ba(SH),  is  formed  by 
saturating  a  warm  solution  of  barium  hydroxide 
or  sulphide  with  sulphuretted  hvdrogen,  evapo- 
RLting  apart  from  the  air  and  cooling,  when 
crystals  of  baryta  and  yellow  prisms  separate 
out  The  mother  liquor  is  mixed  with  au>ohol, 
filtered  from  the  sulphur  and  biuinm  thio- 
sulphate  formed,  and  cooled  to  —10^,  when 
colourless  transparent  four-sided  prisms  are 
obtained.  The  crystals  contain  water,  which 
they  lose  on  heating,  becoming  white.  Exposure 
to  air  decomposes  the  crystals,  with  efflorescence, 
into  barium  thiosulphate  and  sulphate.  Heated 
in  a  retort,  they  lose  their  water  of  crystallisatton 
without  fusing,  evolving  sulphuretted  hydrogen 
as  the  temperature  approaches  redness,  and 
leaving  a  yellow  mass  of  barium  monosulphide, 
which  becomes  white  on  cooling.  It  is  insoluble 
in  alcohol. 

Veley  (Chem.  Soo.  Trans.  1886, 309)  finds  that 
the  composition  of  crystals  of  barium  sulphydrate 
is  Ba(SH).,4H,0. 

Barium  frisulphido  BaS,  is  formed  as  a 
greenish-yellow  mass  when  2  parts  of  barium 
sulphide  are  fused  with  1  part  of  sulphur,  the  ex- 
cess of  sulphur  being  distilled  off  below  360^  It 
melts  at  400'  with  loss  of  sulphur  and  formation 
of  a  black  liquid.  On  boiling  for  some  time  with 
water  it  dissolves  to  a  red  liquid  which  deposits 
on  cooling  crystals  of  the  hydzated  mono-  and 
tetrasulpmdes  of  barium. 

Barium  tstrasul^ilde  BaS4.    When  7  parts  of 

barium  sulphide  are  boiled  in  water  with  4  ^arts 

I  of  sulphur,  pale-red  riiombio  prisms  are  deposited* 


BARIUM. 


047 


aoluUe  in  water  to  a  red-coloured  liquid  from 
which  alcohol  |.recipitate8  it  as  an  crange- 
c<^oared  civBtallme  powder. 

Veley  (Chem.  Soc.  Trans.  188(%  369)  obtains  it 
by  dissolving  sulphur  in  a  warm  saturated  solu- 
tion of  banum  hydrosulphide ;  the  crystals 
which  separate  out  have  the  composition 
BaS|^H,0. 

When  a  mixture  of  2  parts  of  barium 
hydroxide,  I  part  of  sulphur,  and  25  parts 
of  water  is  boiled,  a  deep  brown  liquid  is 
obtained,  which  on  cooling  becomes  orange-red 
in  colour.  If  this  solution  is  evaporated  rapidly 
until  a  crust  a  formed  on  the  suiiaoe,  on  cooling 
the  liquid  deposits  voluminous  red  prisms  of 
banum  tetrasuiphide  BaS4*HtO  mixed  with 
sulphur  and  banum  thioeulphate.  The  orange- 
red  liquid  contains  sulphur  and  barium  in  the 
proportion  oorrespondii^^with  the  pentasulphide, 
which  appears  to  exist  in  solution,  but  decom- 
poses ouring  evaporation  (Compt.  rend.  63. 
300). 

Barium  p«itasalphld«  BaS,  is  obtained  in 
solution  by  boiling  an  aqueous  solution  of  the 
monosulphide  with  sulphur.  On  evaporation  of 
the  eanstio  alkaline  yellow  solution,  crystals  of 
barium  tetiasulphide  and  sulphur  axe  ootained  : 
BaS.»BaS4-fS. 

Barium  foliriioearboiiate  BaGS,  is  depodted 
as  a  oanary-yellow  crystalline  powder  when  a 
solution  of  barium  sulphide  is  added  to  carbon 
disulphide  (Thenard,  Compt.  rend.  70,  673).  On 
the  large  scale  00  p.o.  yield  may  be  obtained, 
and  lAunas  suggested  its  use  against  the 
phylloxera  in  wine  districts.  Thenard  was  of 
opinion  that  this  barium  salt  would  be  injurious 
to  the  sou,  and  proposed  to  convert  it  into  the 
potassium  salt  by  adding  potassium  sulphate  to 
its  solution. 

Barium  sulphite  BaSO^  is  obtained  as  a  white 
crystalline  precipitate  by  adding  potassium  oi 
sodium  sulphite  to  a  soluble  barium  salt.  Is 
soluble  in  a  warm  solution  of  sulphurous  acid, 
and  crystallises  out  on  cooling  in  six-sided  prisms. 
When  heated  in  closed  vessels  it  is  converted 
into  a  mixture  of  sulphide  and  sulphate,  but 
heated  in  air  the  sulphate  is  the  sole  product 
Bimbaum  and  Wittich  (Ber.  13,  651)  state  that 
BaO  unites  slowly  with  SO.  at  200^  but  more 
rapidly  at  230^  forming  BaSO,. 

Barlom  tuipliata  BaS04  occurs  in  nature  as 
Uurfftes,  or  heavy-spar,  forming  fine  tabular 
crjrstsJs  belonging  to  the  rhombic  system.  It 
is  a  very  common  mineral  in  metalliferous  veina^ 
andT  is  more  particularly  associated  with  lead, 
silver,  and  cobalt  ores.  Clowes  (Chem.  News, 
52,  104)  states  that  the  beds  of  the  new  red 
sandstone  near  Nottingham  are  permeated  by 
minute  crystals  of  heavy-spar,  which  acts  as  a 
cementing  material. 

Crystals  of  artificial  barytes,  identical  in  form 
and  properties  with  native  heavy-sjpar,  ma^  be 
obtamed  by  fusing  certain  metallio  chlondes, 
suoh  as  those  of  manganese,  sodium,  potassium, 
or  even  barium  itoelf,  gradually  dissolving 
barium  sulphate  in  the  fused  mass,  very  slowly 
ooolinff,  and  afterwards  extracting  the  soluble 
chloriaeB  with  water.  By  this  means  Gorgeu 
(Compt.  rend.  06, 1734)  prepared  crystals  much 
larger  than  those  obtained  oy  the  older  process 
of  fusing  potassium  sulphate  with  Mrium 
chloride.     The    sp.gr.    of    the     mineral    and 


of     the    artificial    crystals    variee    from    4*3 
to  4-7. 

Barium  sulphate  has  been  formed  by  Spring 
(BulL  Soc.  cmm.  46,  200)  by  subjecting  an 
intimate  mixture  of  molecular  proportions  of 
sodium  sulphate  and  barium  carlranate  to  great 
pressure.  It  is  precipitated  as  a  heavy  white 
amorphous  powder  of  Bp.gr.  4'0-4*5,  when 
sulphuric  acid  or  a  solubfe  sulphate  is  added 
to  the  solution  of  a  barium  salt ;  this  precipitate 
is  neariy  insoluble  in  water  (1  pt.  m  23i2,588 
pts.),  veiy  slightly  soluble  in  dilute  acids,  more 
so  in  strong  acids.  Concentrated  sulphuric 
acid  does  not  attack  anhydrous  baryta,  but 
pyrosulphurio  acid  attacks  it  so  violently  that 
the  mass  becomes  incandescent,  and  forms 
barium  sulphate.  For  heat  of  combinations 
of  Ba  and  SO4  ions  see  Bull.  Soo.  chim.  1018 
(iv.),  23,  13.  When  freshly  precipitated,  it 
il  readily  soluble  in  concentrated  sulphuric  acid 
at  100*,  the  solution  depositing  on  cooling 
lustrous  prisms  of  the  acid  barium  sulphate 
BaHt(S04)s.  If  the  acid  solution  be  exposed 
to  the  air,  moisture  is  taken  up,  and  siDrv  needles 
of  a  salt  having  the  composition  BaHt(S04)tt 
2HaO  are  deposited.  Both  these  acid  salts  are 
decomposed  oy  water,  yielding  sulphuric  acid 
and  the  neutral  salt. 

Barium  sulphate  is  also  soluble  to  a  per- 
ceptible extent  in  ammonium  and  potassium 
nitrates.  Hydrobromio  acid  solution  containing 
40  p.0.  HBr  dissolves  it  to  the  extent  of  1  in 
2500  parts  acid  (Haslam,  Chem.  News,  53,  87 ; 
Karaoglanow.  Zeitach.  anal  Chem.  1017,  56, 
225). 

Barium  sulphate  is  partially  decomposed  by 
l)oiling  with  a  concentrated  solution  of  a  fixed 
alkaline  carbonate  into  alkaline  sulphate  and 
barium  carbonate,  but  the  reaction  is  much  more 
oomplete  when  the  sulphate  and  alkaline  car- 
bonate are  fused  together.  It  is  reduced  to 
sulphide  by  ignition  with  charcoal  or  organic 
matter,  also  by  ignition  in  a  stream  of  cou  gas 
or  of  hydrogen  mixed  with  vapour  of  carbon 
disulphide. 

I^wdered  heavy-spar  is  used  to  adulterate 
white  lead,  but  has  not  suffioi«int  body  to  form 
a  pigment  by  itself ;  the  amorphous  sulphate  is 
prepared  on  the  larse  scale  bv  precipitation  of  a 
solution  of  barium  diloride  of  sp.gr.  1*10  bv  one 
of  sulphuric  acid  of  sp.gr.  1  *245,  and  is  used  as  a 
pigment  under  the  name  of  *  permanent  white ' 
or  *  blano  fixe.' 

Bariom  sodium  sulpiiata  BaNa,(SOJa  is 
formed  as  an  opaque  hard  mass  of  peuly  lustre 
by  fusing  togetner  equivalent  quantities  of  tibe 
sulfates  of  sodium  and  barium  (Berthier). 

Barinm  dtsulphate  BaS.Oy.  If  preoipitated, 
barium  sulphate  be  dissolved  in  fummg  sul- 
phuric acid,  and  the  solution  heated  to  iSf,  on 
cooling  a  clistening  deposit  of  jzranular  crystals 
of  the  dismpbate  is  obtained.  Decomposition  of 
these  crystals  occurs  at  a  low  red  heat  without 
previous  fusion. 

Bariom  ditUonato  BaSiOc,2H,0.    Ptepared 

by  adding  barium  sulphide  to  the  manganese  salt 

formed  on  puiiBing  sulphur  dioxide  through  finely 

divided  manganese  dioxide  suspended  in  water : 

MnS.Og-fBaS^linS-i-BaS.O,. 

On  allowing  the  solution  to  evaporate  in  a 
warm  phice,  gkttering  monookxDio  or^stils  of  the 
ialt  are  deposited  of   the  compotiUou  BaS/)«, 


M8 


BARIUM. 


t 


2H,0.  According  to  86iiMmont  aad  Ram- 
melsberg,  the  crystals  are  riiombic.  According  to 
V.  Lang  (Sita"'.  B.  [2]  45, 27 ),  they  are  monoclinic. 

The  orystalB  are  soluble  in  4  parts  of  water 
at  18*  and  in  M  parts  at  100*.  When  the 
dry  salt  is  heated,  it  breaks  np  into  sulphur 
dioxide  and  barium  sulphate.  The  same  de- 
composition ooours  on  boiling  with  hydrochloric 
acid,  but  the  solution  of  the  dithionate  itself  io 
water  may  be  boiled  without  decomposition. 

A  tetrahydrate  BaS20«,4H,0  may  also  be 
obtained  by  spontaneous  evaporation  in  dif^inct 
shining  monoclinic  crystaLs,  which  eflSoresce  on 
exposure  to  air. 

Barium  thlMVlphaia 

BaS,0,^sO  or  BaH,(80|), 

is  obtained  as  a  white  crystalline  precipitate 
when  Uie  sodium  salt  "Stkfifi^  is  added  to  barium 
acetate ;  it  loses  its  water  of  crystallisation  at 
215*.  The  anhydrous  salt*  when  heated  to  red- 
ness, gives  off  sulphur  and  leaves  a  residue  of 
barium  sulphide,  sulphite,  and  sulphate  : 

6BaStO,»BaS+2BaSO,+3BaSO«+6S. 

Barium  selenldo  BaSe  is  formed  by  heating 
barium  selenite  to  redness  in  a  stream  of  hydro- 
gen. It  is  decomposed  by  water  into  barium 
hydroxide  and  a  higher  selenide,  which  is  decom- 
posed by  acids  with  evolution  of  H^Se  and 
precipitation  of  selenium. 

Barimn  selenate  BaSe04  resembles  the  sul- 
phate in  being  insoluble  in  water,  but  differs 
from  it  in  being  decomposed  by  hydrochloric 
aoid  into  selenite,  which  dissolves  in  the  hydro- 
chloric acid. 

Barium  ehromate  BaCrOf  is  precipitated  as 
a  yellow  crystalline  powder  when  potasaium* 
ohromate  or  bichromate  is  added  to  the  solution 
of  a  barium  salt.  The  salt  may  be  obtained  in 
green  rhombic  crystals  isomorphous  with  BaSO^ 
by  heating  two  equivalents  of  BaCL  with  one 
equivalent  of  potassium  chromate  and  one  of 
sodium  chromate,  and  allowing  the  mixture  to 
cool ;  the  chlorides  may  be  boiled  out  with  ^vatcr, 
leaving  the  right  rhombic  prisms  of  BaCrOf,  of 
sp.gr.  4*0.  'fiiey  are  insoluble  in  water,  but 
are  easily  soluble  in  hydrochloric  and  nitric 
acids,  and  are  decomposed  b^  sulphuric  acid  into 
Ba804  and  CrO,  (Bourgeois,  Compt.  rend.  88, 
382). 

The  precipitated  chromate  is  used  as  a  pig- 
ment under  the  name  of  *  lemon  yellow'  or 
*  yellow  ultramarine.*  When  strong  sulphuric 
acid  is  added  to  the  dry  pigment,  great  heat  is 
developed,  and  it  is  coloiued  deep  red  from 
liberation  of  CrO,.  If  it  be  now  ground  in  a 
mortar  and  heated  to  bright  redness,  the 
chromic  acid  is  reduced  to  chromic  oxide,  and  a 
fine  green  pigment  is  obtained  (Douglas,  Chem. 
News,  40,  59). 

Barium  dlchromate  BaOsOf  is  obtained  by 
dissolving  barium  chromate  in  not  concentrated 
chromic  acid.  On  cooling,  red  crystals  of  the 
composition  BaGr|0.,2H|0  are  deposited,  which 
lose  their  water  at  100*,  and  are  decomposed  by 
water  into  the  normal  chromate  and  chromic 
aohydride  (FreiB  and  Rayman,  Ber.  13,  340). 

^mn  maDfanate  BaMhOi  is  formed  when 

lee  dioxide  is  heated  with  barium  car- 

m  nitrate  as  an  emerald-green  powder 

g  of  microscopic  four-sided  prisms  or 


six-sided  plates,  insoluble  in  water  but  decom- 
posed by  aoids.  This  salt  is  now  used  in  plaoe 
of  the  poisonous  Scbeele's  men. 

Barium  pennanganate  BaMn,0,  is  prepared 
by  passing  oarbonio  acid  gas  through  water 
containing  barium  mancanate  in  suspension ; 
after  filtering  off  the  banum  carbonate  the  red 
solution  is  rapidly  evaporated.  Or  it  may  be 
obtained  by  uie  action  of  barium  chloride  on 
silver  permanganate. 

Or  potassium  permanganate  may  be  decom- 
posed by  slight  excess  of  hydrofluosilicic  aoid, 
the  mixture  Kept  oool«  and,  after  separation  of 
the  precipitated  potassium  silicofluoride,  the 
supernatant  solution  decanted  and  saturated  in 
the  cold  with  barium  hydroxida  After  separation 
of  the  insoluble  barium  silicofluoride,  the  solution 
is  evaporated  untfl  the  barium  permanganate 
separates  out  on  cooling  (Rousseau  and  Bruneau, 
Compt.  rend.  98,  229)^ 

It  forms  large  orthorhombic  octahedra,  deep- 
red  and  almost  olack,  with  a  violet  reflection. 

It  is  used  for  Uie  preparation  of  permanganic 
aoid  and  of  t^e  ammonium  salt. 

Rousseau  and  Sa^er  (Compt.  rend.  99,  139) 
find  that  on  heating  two  grams  of  barium  man- 

?^anate  with  ten  grams  ca  barium  chloride  for 
our  hours  to  15(^*,  and  extracting  with  water 
and  dilute  acid,  a  residue  of  small  opaque 
bluish-black  crystals  of  barium  manoanite 
BaMnO.  remains ;  sp.gr^  6*85 ;  readily  soluble  in 
hydrochloric  acid  with  evolution  of  chlorine. 
Tlie  manganite  is  also  formed  when  mixtures  of 
manganese  chloride  and  barium  oxyohloride  are 
heated  below  1000*  or  above  llOOi^.  Between 
these  temperatures  the  product  is  barium  di- 
manganito  BaO-2MnOt,  which  crystallises  in 
biriUumt  black  lamellsB.  At  1600*  the  manganite 
is  reconverted  to  mannuiate. 

Buium  phosphide  Sa,P^  When  vapour  of 
phosphorus  is  passed  over  red-hot  bwvta,  a 
brownish-red  mixture  of  barium  phosphide  and 
phosphate  is  obtained  commonly  known  as 
phosphuret  of  baryta.'  It  is  decomposed  by 
water,  forming  a  solution  of  hypophosphite  of 
barium  and  evolving  a  mixture  of  free  hydrogen 
and  spontaneously  inflammable  phosphoretted 
hydrogen. 

JaBoin  (Compt.  rend.  129,  762)  prepared  the 
phosphide  b^  heating  100  parts  of  barium 
phosphate  with  16  piwts  of  lamp  black  in  an 
electric  furnace.  The  product  so  obtained  has 
a  crystalline  structure.  It  decomposes  water, 
yieldSnff  PH,  and  Ba(OH),. 

Bartum  monometaphosphata  is  obtained  as 
a  white  powder  by  evaporating  a  solution  of 
barium  carbonate  m  excess  of  metaphorohoric 
acid  and  heating  the  residue  to  316*.  Its 
formula  is  not  known  with  certainty. 

Barium  dImeUphosphate  Ba(PO,).,2HaO  is 
formed  as  a  ci^stalline  sparingly  soluble  precipi- 
tate when  barium  chloride  is  added  to  a  solution 
of  the  corresponding  ammonium  or  sodium  salt. 

Barium  trimetaphosphate  Ba,P,0i„6H,0, 
apparently  a  polymeric  form  of  the  last  salt,  is 
produced  when  a  solution  of  1  pcurt  of  the  corre- 
sponding sodium  salt  in  10  to  15  parts  of  water 
is  mixeS  with  a  nearly  saturated  solution  of 
3  parts  barium  ddonde.  On  standmg,  the 
salt  separates  in  monoclinic  prisms,  whioE  give 
off  two-thirds  of  their  water  at  100*,  and  the 
rest  at  a  higher  temperature. 


BARIUM. 


540 


Btriam  bexamctaphosphate  is  obtained  as 
ft  gelatinoQB  precipitate  by  precipitatinff  the  oor- 
responding  sodiam  salt  witn  barium  chloride. 

Monobarimn  orOiophosphate  BaH^CPOA),  is 
prepared  by  eraporating  a  solution  of  the  di-  or 
tri-CMtfinm  salt  in  aqueous  phosphoric  acid.  It 
forms  colourless  crystals— triclinio  according  to 
Erlenmeyer,  with  acid  reaction ;  soluble  without 
decomposition  in  a  small  quantity  of  water,  but 
decomposed  by  excess  of  water  mto  free  phos- 
phoric acid  and  the  neutral  salt. 

Joly  (Gompt.  rend.  98,  1274)  states  that  as 
the  total  weignt  of  salt  brought  in  contact  with 
the  same  quantity  of  water  increa|M«  in  arithme- 
tical progression,  the  weight  which  is  dissolved 
without  decomposition  decreases  in  geometrical 
progression ;  but  as  soon  as  half  the  original  salt 
has  been  decomposed  a  diacid  salt  ia  formed 
BaO*2P,Os+arH|0,  the  proportion  of  which 
increases  as  the  acidity  of  the  liquid  increases, 
and  eventually  exists  alone  in  solution. 

DflMrium  orthftpbosphate  Ba,Ht(F04)t  or 
BaHP04  is  obtained  as  a  white,  scaly,  crystalline 
precipitate  when  hydrogen  disodium  phosphate 
is  added  to  a  neutral  sSution  of  a  barium  salt. 
It  is  soluble  in  20,670  parts  of  water  at  20*, 
somewhat  more  soluble  in  water  containing 
barium  or  sodium  chloride  or  ammoniacal  salts. 
¥Vom  the  solution  in  nitric  or  hydrochloric  acid 
excess  of  ammonia  precipitates  the  tribarium 
ssJt  or  a  salt  intermediate  between  the  two. 
Thus,  according  to  Wackenrgdcr,  a  solution  of 
BaHP04  in  nitric  acid  yields,  on  addition  of 
ammonia,  a  precipitate  of  barium  phosphato- 
nitrate  4Bain*04*^(NO,)2»  which  leaves,  on 
heating,  a  mixture  of  di-  and  tri-barium  phos- 
phates. 

By  precipitating  a  solution  of  dibarium  phos- 
phate with  alcohol,  a  salt  intermediate  between 
the  mono-  and  di-salts  is  obtained : 

BaH4(P04),  •2BaHP04,3H,0. 

If  a  mixture  of  potassium  silicate  and  baryta 
water  is  boiled,  and  afterwards  mixed  with  a 
solution  of  potassium  silicate  containing  a  quan- 
tity of  potassium  phosphate,  on  cooling,  cuoical 
crystsJs  of  the  composition  BaKPOfplOHJO 
separate  out.  BaNaPO4,10H,O  was  similany 
obtained  in  regular  tetrahedrons  (Be  Sohulten, 
Compfe.  rend.  06,  706). 

Tribarimn  ortbopbospbato,  or  neutral  phos- 
phate of  barium,  Ba,(P04)t*H,0  is  prepared  by 
adding  hydrogen  disodium  phosphate  to  a  solu- 
tion of  buium  chloride  rendered  strongly  alkaline 
by  ammonia,  and  separates  as  a  heavy  granular 
powder.  It  parts  with  a  portion  only  of  its 
water  at  200*. 

If  a  saturated  solution  of  tribarium  phos- 
phate in  hydrochloric  acid  is  evaporatea,  on 
cooling,  crystals  of  barium  chlonde  are  do- 
posited,  more  and  more  monobarium  phosphate 
oeing  left  in  solution,  and  if  more  hydroonloric 
acid  IS  added,  all  the  barium  may  be  ciTstallised 
out  as  barium  chloride,  and  pure  phosphoric 
acid  remains. 

If  the  solution  of  tribarium  phosphate  in 
hydrochloric  acid  is  boiled,  ahining  neeoles  form 
in  the  liquid,  and  on  adding  sufficient  water  to 
redissolve  them,  well-definea  cr3rptals  of  a  phos- 
phato-chloride  4BaH4(P04).*BaCl,  are  deposited 
on  standing  (Erlenme^rer,  J.  1867,  147). 

According  to  Ludwig,  a  solution  of  dibarium 


phosphate  in  hydrochloric  acid  also  yields,  on 
addition  of  ammonia,  a  phosphato-chloride  con- 
taining 3Ba,H,P40|4-Baa,-3H,0. 

A  salt  intermediate  between  the  di-  and  tri- 
phosphates, containmg  Ba,(P04)a'2BaHPO«  oc 
Ba,H2P40|4,  is  formed  when  a  solution  of  the 
dibarium  phosphate  in  hydrochloric  acid  is 
mixed  with  a  quantity  of  ammonia  just  sufBcient 
to  m«cipitate  it. 

Barium  pyropbospbato  Ba,PaOf.  P^- 
phosphoric  acid  does  not  precipitate  barium 
salts,  but  with  bar}^  water  gives  a  precipitate 
of  barium  pyrophosphate.  &rium  nits,  how- 
ever, give  with  sodium  pyrophosphate  a  white 
amorphous  precipitate  of  l!arium  pyrophosphate, 
soluble  in  aqueous  pyrophosphonc  and  sulphur- 
ous acids ;  more  soluble  in  hydrochloric  or  nitric 
acid,  but  not  perceptibly  soluble  in  water  con- 
taining ammonium  chloride  or  in  acetic  acid. 

Monobarlom  araenate  BaH4(As04)2  ib  ob- 
tained by  adding  baryta  water  to  aqueous  arsenic 
acid  until  a  precipitate  begins  to  form,  or  by  dis- 
solving the  dibarium  salt  in  aqueous  arsenic 
acid  and  leaving  the  solution  to  crystaUise. 

Dibarium  araemite 

2BaHAs04»H,0  or  BaHAs04,H,0 

according  to  Berzelius,  is  obtained  when  a  solu- 
tion of  tne  disodium  salt  is  added  to  excess  of 
barium  chloride.  It  gives  up  its  water  at  a  red 
heat,  and  in  contact  with  water  is  decomposed 
into  the  tribarium  salt,  which  is  precipitated, 
and  the  monobarium  salt,  which  dissolves. 

Tribarium  arsenate  Ba,(As04),  is  obtained  as 
a  white  sparingly  soluble  powder  by  precipitating 
aqueous  arsenic  acid  with  baryta  water,  or  better, 
by  gradually  dropping  trisodium  arsenate  into 
barium  chloride, 

Bartam  ormo-tbloanaoata  Baa(AsS4)a  is 
obtained  together  with  Ba(AsS9)g  by  the  action 
of  hydrogen  sulphide  on  a  solution  of  BaHAs04. 
The  banum  tnioarsenate  U  precipitated  J>y 
adding  alcohol  Arsenic  pentasulphide  pre- 
pared by  the  action  of  a  rapid  stream  of  hvdrtMen 
9uiphide  on  a  solution  of  arsenic  acid  and  hyouo- 
chioric  acid,  reacts  with  a  freshly  prepared 
solution  of  Ba(SH)a  according  to  the  equation 

3Ba(SH)«+ As,Ss»Ba,As^4 +3HaS 
After  evaporation  transparent  yellow  needles 
of  Ba,As^,,6H,0  separate  (Zeitsch.  anorg. 
Chem.  70,  86).  A  solution  reacts  with  potassium 
chloride  yielding  potassium  barium  ortho- 
thioarsenate  BaKAsS4,6H|0,  which  may  also 
be  prepared  direct  by  adding  KCl  to  a  solution 
of  Ba(SH)a  saturated  with  AsaS|. 

Barium  slUeate.  Solutions  of  baryta,  when 
kept  in  glass  bottles  for  any  length  of  time, 
deposit  transparent  rhombic  crystals  of  the 
composition  BiGtSiOt,7H,0.  These  crystals  lose 
their  water  a  little  above  100*,  and  become 
turquoise-blue  :  they  are  decomposed  by  boiling 
water  (Le  Chatelier,  Compt.  rend.  02,  031); 
Cossa  and  Lavalle  (Zeitsch.  I.  Chem.  11,  300). 

According  to  Lc  Chatelier,  they  may  be  readily 
obtained  in  a  few  days,  by  suspending  calcined 
silica  in  baryta  water,  when  tne  sides  become 
oovered  with  crystals. 

Barium  dlslueata  BaSi.Os  has  been  prepared 
synthetically.  It  crystalliBea  in  the  ortho- 
rhpmbic  system.  The  colourloea  six-sided  plates 
which  form  in  opticsJ  glass  nch  in  barium 
have  been  identified  with  this  com^x&nd. 


6fi0 


BARIUM. 


Barlom  tttamtte.  When  eqaivalent  quan- 
fcities  of  titanio  anhydride  and  barium  carbonate 
are  fused  at  a  bright  red  heat  for  an  hour  with 
excess  of  barium  chloride,  and  the  product 
extracted  with  very  dilute  hydrochloric  acid,  a 
residue  of  yellow  microscopic  crystals  resembling 
cubes  and  octahedra  of  the  composition  | 

2BaO-3TIO, 

and  of  sp.gr.  6*91  remains  undissolved.  These 
crystals  are  found  on  examination  by  polarised 
light  to  consist  of  aggregations  of  rhombic 
lamelln. 

ReaetioDs  of  (he  compounds  of  barinm. 
When  heated  on  a  thin  platinum  wire  in  the 
inner  blowpipe  flame,  or  when  brought  into  any 
non -luminous  flame,  barium  compounds  impart  a 
yellowish-green  colour  to  the  o^tor  flame.  When 
viewed  through  the  spectroscope  two  green  lines 
Baa  and  Ba^  come  out  most  intensely ;  Bay, 
though  not  so  marked,  is  also  a  characteristic 
line.  Besides  these,  there  are  numerous  lines 
in  the  red  and  yellow  and  one  broad  indis- 
tinct line  in  the  olue,  close  to  IVaunhofer's  F. 
Bunsen  found  that  i^  of  a  milligram  of  barium 
salt  may  be  detected  spectroscopically.  Silicates 
of  barium  give  this  reaction  on  moistening  with 
strong  hycuochloric  aoid. 

The  hydrate,  sulphide,  chloride,  bromide, 
iodide,  nitrate,  and  many  organic  salts  of  barium 
aro  soluble  in  water,  and  idl  are  poisonous.  The 
majority  of  the  remaining  salts  are  soluble  in 
hydrochloric  and  nitric  acids,  whilst  the  sulphate 
and  silicofluoride  are  insoluble  in  all  acids. 

Alkaline  carbonates  precipitate  white  barium 
carbonate,  soluble  in  most  acids,  hence  ammo- 
nium carbonate  is  used  to  precipitate  it  (along 
with  the  carbonates  of  strontium  and  calcium) 
in  qualitative  analysis. 

Potassium  and  sodium  hydroxides,  free  from 
carbonates  and  sc^phates,  give  a  voluminous 
preoipitate  of  barium  hydroxide  Ba(OH),  with 
concentrated  solutions  soluble  in'mdro  water. 
Ammonia  gives  no  precipitate. 

Sulphuric  acid,  as  well  as  all  soluble  sul- 
phates, throws  down  barium  sulphate  from  all 
solutions  of  barium  salts.  Pickering  (Ghem. 
News,  40,  223)  states  that  the  smallest  quantity 
of  buium  which  can  be  detected  is  1  part  in 
833,000  parts  of  water.  The  presence  of  an 
alkaline  citrate  greatly  interferes  with  the 
precipitation.  Strontium  sulphate  (which  is 
more  soluble)  forms  a  delicate  test  for  barium. 

Phosphate,  arsenate,  borate,  and  iodate  of 
sodium  also  give  precipitates  soluble  in  acids. 

Ammonium  oxalate  gives,  from  moderately 
dilute  solutions,  a  white  pulverulent  precipitate 
of  barium  oxalate. 

Potassium  chromate  precipitates  bright 
lemon-yellow  barium  chromate,  soluble  in  nitric, 
hydrochloric  or  chromic  acid,  insoluble  in 
dilute  acetic  acid. 

Hydrofluosilicic  acid  gives  a  colourless  cr^^s- 
talline  precipitate  of  barium  silicofluoride ;  this 
reaction  will  detect  1  part  of  tiie  chloride  in 
3800  parts  water.  The  precipitate  is  nearly  in- 
soluble in  nitric  and  hydrochloric  acids,  more 
insoluble  in  alcohol. 

Barium  is  readily  distinguished  from  lead 
{which  also  forms  a  sulphate  insoluble  in  water)  by 
the  fact  that  sulphuretted  hydrogen  flives  a  black 
precipitate  of  lead  sulphide  with  solulue  lead  salts. 


Soluble  barium  salts  are  at  once  distinguished 
from  those  of  strontium  and  calMnm  by  the  fact 
that  they  are  immediately  precipitated  by  a 
solution  of  calcium  sulphate,  which  only  spyes 
a  precipitate  with  strontium  salts  on  stanaing. 
The  hydrofluosilicic  acid  reaction  is  also  of 
u.5e  in  separating  barium  from  the  other 
two  metals.  Barium  chloride  is  insoluble  in 
alcohol,  whilst  the  chlorides  of  strontium  and 
calcium  are  soluble,  and  the  nitrates  of  barium 
and  strontium  are  insoluble,  in  alcohol,  whUsfc 
calcium  nitrate  is  soluble.  From  the^  facts  a 
scheme  of  separation  is  readily  derived,  the  pre- 
cipitated  caroonates  of  barium,  strontium,  and 
caicium  being  converted  into  chlorides,  and  the 
chlorides  of  strontium  and  calcium  dissolved  out 
by  alcohol,  leaving  a  residue  of  chloride  of 
barium,  llie  strontium  and  calcium  may  then 
be  separated  by  converting  their  reprecipitated 
carbonates  to  nitrates  and  dissolving  out  the 
calcium  nitrate  (v.  Akaltsis). 

Estiiiiatloii  of  barium.  When  no  other 
alkaline  metal  is  present,  barium  may  be  esti- 
mated as  sulphate.  A  solution  of  the  chlorides 
sliffhtly  acidified  with  hydrochloric  acid  is  best. 
Smphurio  acid  is  added  cautiously  to  the  hot 
solution  in  slight  excess.  The  procipitato  is 
allowed  to  settle  in  a  warm  place  for  some  houcs 
before  filtering. 

For  precautions  and  efifect  of  salts,  see  work 
of  Karooglanow  (Zeitsch.  anaL  Chem.  or  Abstrs. 
J.  Chem.  Soc.  for  1017).  For  details  of  volu- 
metric estimation  of  barium  by  separation  as 
chromate  and  titration  of  lib^ted  iodine,  on 
addition  of  KI  to  HGl  solution,  see  Analyst, 
43,  287. 

Li  its  organic  salts  barium  may  be  estimated 

as  carbonate  by  heating  in  a  platinum  crucible 
and  subsequent  moistening  of  the  reeidne  with 
a  concentrated  solution  of  ammonium  car- 
bonate, evaporation,  genile  ignition,  and  weigh- 
ing. 

Where  strontium  and  calcium  are  present, 
after  the  separation  of  the  other  elements,  the 
alkaline  earths  are  precipitated  by  ammonia  and 
ammonium  carbonate.  This  precipitate  is  then 
dissolved  in  acetic  acid,  and  the  barium  twice 
precipitated  as  chromate,  in  which  form  it  may 
be  weighed  or  dissolved  in  hydrochloric  acid, 
then  precipitated,  and  weighed  as  sulphate. 

Q.  S.  B. 

BARK  BREAD.  A  kind  of  bread  which  was 
formerly  made  by  the  peasants  in  various  parts 
of  Norway  from  the  inner  bark  of  Pt aim  symsirif 
(Linn.).       

BARKLTTTE  v.  CoTLxnsmxm. 

BARLEY.  Two  species  are  in  oommon 
cultivation — Hordeum  disliehum,  two-rowed, 
ani  H.  mdgare,  six-rowed.  Many  Tarieties  are 
known,  diJSering  in  size  and  shape  of  ear  and 
grain.  The  two-rowed  varieties  are  chiefly 
grown  as  spring-sown  crops,  iwiiile  the  six-rowed 
varieties  are  often  sown  m  the  autumn. 

The  grain  resembles  in  composition  that  of 
other  cereals,  but  contains  less  gluten  than 
wheat ;  moreover,  the  eluten  of  barley  is  not 
so  tenacious  as  that  of  wheat;  conseaoeotly, 
barley  meal  does  not  yield  a  satisfactory  oread. 

Barley  is  chiefly  grown  for  cattle-feeding  and 
for  malt  production.  For  the  latter  purpose,  a 
grain  containing  but  little  nitrogenous  matter  is 
preferred,  so  that  too  lavish  nitrogenous  manur- 


BARLEY. 


551 


ing  must  be  avoided  in  the  production  of  malting 
bwley. 

Tne  foOowing  are  analyses  of  typical  average 
barley  ae  given  l)y  1,  Warington  ;  2-5,  Kellner 
(German) ;  6,  Wiley  (of  American  barley). 

The  table  lepreeents  the  composition  of 
barley  expressed  in  the  usual  manner.  The 
item  'nitrogenous  substances'  is  simply  the 
total  nitrogen  X  6-25.  Of  the  total  nitrogen,  a 
small  portion — probably  about  ^Jg — is  present  in 
non-albuminoid  form. 


1 

2 

8 

4 

6 

8 

Bng- 
lish 

Med- 

Large 

Flat 

Feed- 

Amer- 

ian! 

gr'nd 

gr'nd 
14-8 

ing 

ican 

Water     .     . 

14-8 

14-3 

14-8 

14*8 

10-86  , 

MitrogauNis 

1 

•ubstsnoet 

lO-fti 

0-4 

8-7 

10-2 

12-0 

11-00 

Fat    .     .     . 

2-1 

2-1 

1-8 

2-5 

2-4 

2-26 

Soluble  cartx)- 

1 

hydiatet  . 

06*0 

67-8 

70-2 

«8-7 

«8-7 

69*55  ' 

4-6 

8-9 

2-7 

6-6 

60 

8-85  1 

Ash    .     .     . 

2*6 

2-5 

2-8 

2-8 

2*8 

2-60  1 

According  to  Osborne  (18th  Ann.  Rep.  Conn. 
Expt.  St.),  the  proteids  in  barley  are :  (1)  Soluble : ' 
leucosine  0-30  p.o.,  hordein  4-0  p.c.,  edestine 
and  proteose  1-05  p.c. ;  (2)  insoluble  proteids 
4*50  p.0.  The  soluble  proteids  just  mentioned 
oontam  an  average  of  17*6  p.o.  of  nitrogen,  so 


that  the  factor  to  convert  nitrogen  into  proteids 
in  barley  should  be  much  less  than  6-25,  probablv 
about  5  *7.  Consequently,  the  amount  ofproteids 
in  barley  should  be  about  1  p.o.  less  ana  that  of 
carbohydrates  (since  they  are  determined  by 
difiference)  1  p.c.  more  than  the  values  given  in 
the  tables. 

Under  the  heading  *  soluble  carbohydrates ' 
are  included  :  pentosami  6*5  p.c.  (BulL  13,  U.S. 
Bent,  of  Agric.  1898) ;  cane  sugar  0-8~lSS  p.c 
(O^^ullivan,  J.  Chem.  Soc  1886,  49,  58) ;  1*3  p.c. 
(Banister,  C3iem.  News,  1885,  298);  0-2  p.o. 
(Bull.  13,  Z.e.) ;  small  quantities  of  reducing  sugars 
(O'Sullivan) ;  dextrine  and  raffinose  (O'Sullivan). 
The  remainder  is  chiefly  made  up  of  starch  and 
cellulose,  though  gum  2-8  p.o.  (Muntz,  Compt. 
rend.  102,681)  and  amylan  2-4  p.c.  (O'Sullivan, 
J.  C!hem.  Soc.  41,  24)  have  also  oeen  found. 

•  Barley  contains  diastase  even  before  germina- 
tion (when  its  amount  is  enormously  increasted). 
Brown  and  Morris  (J.  Chem.  Soc.  1890,  505) 
recognise  two  kinds  of  diastase — of  secretion,  as 
formed  in  germination,  which  rapidly  corrodes 
starch  granules,  and  of  displacement — present 
in  the  ungerminated  grain- which  slowly 
diminishes  the  volume  of  starch  granules  with 
out  visibly  corroding  them. 

The  ash  of  barley,  neglecting  the  CO,,  has 
the  average  composition : 


— 

K,0 

KasO 

CaO 

KgO 

8-23 
7-87 
8  62 

FejOs 

P»0, 

80, 

CI 

SiOg 

'  Mean,  28  American  samples 
'      „      19  Canadian        „ 
M      Wolffs  analyses 

24  15 
26-78 
2015 

6-42 
9-36 
2-35 

2-44 
4-27 
2-60 

0-33 
0-35 
0-97 

36-47 
24-63 
34-68 

0  22 
0-71 
1-69 

0-56 
0-47 
0-93 

22-30 
20-69 
27-54 

For  a  full  yield  of  barley  the  soil  must  be  wcU 
supplied  with  plant  food*  including  combined 
nitrogen,  but  Buch  a  crop,  though  excellent  from 
the  Mrmer's  point  of  view  and  valuable  for 
feeding  purposes,  is  rarelv  suited  to  the  maltster's 
requirement.  Good  maltina  barley  should  be  as 
rion  as  possible  in  starch  ana  low  in  albuminoida 
Between  8  and  9  p.c.  of  nitrogenous  matter  is 
nsaally  regarded  as  the  most  aesiiable  propor- 
tion in  malting  barley.  If  grown  in  hot,  dry 
countries,  e.g.  Southern  Russia,  it  is  usually 
richer  in  nitrogen.  The  best  malting  barleys 
are  grown  on  light  soils  not  too  rich  in  nitrogen, 
and  in  temperate  climates  (e.  BsswiNO). 

Owing  to  the  injurious  effect  of  too  lavish  a 
supply  of  nitrc^n  upon  the  maltins  properties 
of  iMurlev,  it  is  by  many  considered  Best  to  take 
the  barley  crop  after  wheat,  rather  than  after 
roots,  thoush  the  latter  procedure  is  often 
adopted  in  Ireland. 

Pearl  barley  is  barley  deprived  of  its  husk.  Ame- 
rican analyses  give  as  its  aver^  composition  : 
Water,  10*8  p.a ;  protein,  9-3  p.c. ;  fat,  10 
p.0. ;  carbohydrates,  77*6  p.c. ;  asn,  1-3  p.c. 

Aooording  to  Wolff's  analyses,  the  ash  of  the 
barley  kemelamounts  to  2-13  p.c.,  and  100  parts 
of  the  ash  contain  : 

KjO    Na«0    CaO    HgO    FesOa   PfOi    SOs    SiOt 
28-6    fS      3-1     12-0      1-9     471    2-9    3-6 

BarkOT  liraw  ii  much  more  affected  in  com- 

*  Of  which  10*2  p.c.  are  albamlnotds. 

*  Compoelte  sainples  from  the  World's  Columblau 
Expoeltkm  (Wiley.  BuU.  13.  U.S.  Dept.  of  Agric), 


position  than  the  grain  by  the  richness  or  poverty 
of  the  soil,  and  by  the  conditions  under  which  it 
is  srown.  If  the  ripening  of  the  grain  has  been 
fuUy  completed,  the  straw  is  robbed  of  its  nitro- 
genous matter  and  phosphates  to  a  much  greater 
extent  than  when  the  seed  has  not  been  fully 
matured.  Thus  the  straw  of  a  crop  cut  before  it 
is  fully  ripe  possesses  much  higher  feeding  value 
than  usual. 

According  to  Kellner,  the  following  repre- 
sents the  average  composition  of  barley  straw : — 

Solable 
Ether  carbohy- 
Water  Protein  extract  drates  Fibre  Ash 
Summer  barley  14-3    3-5       I -4     35-9  39*5  5-4 
Winter  barley    14-3    3*2       1-4     33-5  42-0  5-0 

The  ash  of  barley  straw  (Wolff)  contains : 

KjO   Na,0   CaO  MgO   FetOs  P«Oft   80s    SiO<  CI 
23-3    3-5     7-2     2*6      1-1     4-2     3-9    51-0  3-2 

Barley  straw  con.<«i8ts  laigely  of  cellulose,  and 
pentosans  and  lignose.  The  amount  of  pento- 
sans has  been  estimated  at  about  25  p.a  The 
*  crude  protein '  given  in  the  above  table  is 
probably -nearly  all  true  albuminoids,  since  direct 
experiments  showed  about  91  p.o.  of  the  total 
nitrogen  to  be  present  as  albuminoids.  The 
lowest  portions  of  the  stems  are  least  nutritious, 
while  tne  uppermost  leaves  and  top  of  the  stem 
are  the  most  digestible  and  richest  in  protein. 

When  barley  precedes  clover,  as  is  often  the 
case  in  Englond,  the  barley  straw  is  enriched  by 
including  a  portion  of  young  clover  plants. 
Under  such  circumetanccs,  t^e  product  is  of 


55a 


BARLEY, 


much  higher  feeding  vtlne,  and  contains  more 
protein  (up  to  6  or  7  p.o.)t  and  soluble  carbo- 
nycbrates  (38  or  39  p.o.)»  and  less  crude  fibre. 

BARRESWIL'S  or  FEHUNO'5  SOLUTION. 

It  has  lonK  been  known  that  a  mixture  of 
verdiffris,  honey,  and  Tin^ar,  when  boiled 
toffewer  to  form  an  ointment,  changes  in 
colour  from  green  to  red. 

Vogel  (Sohweigger's  Joum.  13,  162)  proved 
that  the  precipitate  formed  consisted  of  cuprous 
oxide,  and  later  Buchner  attempted  to  explain 
the  part  played  by  the  sugar  in  the  change. 
Trommer  first  used  alkaline  copper  sulphate 
solution  as  a  qualitative  reagent  tor  sugars,  and 
succeeded  in  detecting  one  part  of  grape  sugar 
in  a  million  parts  of  water,  and  also  m  differ- 
entiating between  different  kinds  of  sugars 
(Annalen,  1841,  39,  360). 

Alkaline  copper  solution  was  first  applied 
to  volumetric  analysis  by  Barreswil  (J.  Pharm. 
Chim.  1844,  [3]  6,  301),  who  added  potassium 
tartrate  to  the  solution,  and  the  method  of 
titration  was  worked  out  by  H.  Fehling 
(Annalen,  1849,  72,  106  ;    1858,  106,  75). 

Various  formuln  have  been  suggested  for 
the  preparation  of  Barreswil's  solution  by 
Bddekerr,  Soxhlet,  Meissl,  Herzfeld,  Allihn, 
Kjeldahl,  &c  (Bruhns,  Zeitsch.  anaL  Chem. 
1899,  38,  78).  Indeed,  more  than  fifty  cupro- 
potassic  solutions  are  known.  They  may  be 
divided  into  four  groups,  in  which  potassium 
hydrogen  tartrate,  (2)  potassium  sodium  tartrate, 
(3)  potassium  tartrate,  and  (4)  tartaric  acid  are 
employed.  That  recommended  by  Soxhlet  is 
usually  preferred,  partly  on  account  of  its  small 
alkali  content. 

34*64  grams  of  pure  crystallised  copper 
sulphate,  powdered  and  dried  by  pressure 
between  filter  paper,  is  dissolved  in  distilled 
water  and  dilutea  to  500  c.c. ;  and  70  grams, 
sodium  hydroxide  (of  not  less  iJian  97  p.c.)  and 
180  grams  of  potassium  sodium  tartrate  (Ro- 
chelle  salt)  are  dissolved  in  400  c.c.  of  distilled 
water  and  diluted  to  500  c.c.  Equal  volumes  of 
the  two  solutions  are  mixed  to  form  the  test, 
which  diould  be  kept  in  a  carefully  closed  bottle 
to  prevent  absorption  of  carbon  dioxide,  and 
should  not  be  unduly  exposed  to  light  As  the 
solution  is  liable  to  decomposition,  a  small 
portion  should  always  be  heated  to  boiling  before 
commencing  the  test,  and  the  liquid  should  not 
be  used  if  any  precipitation  occurs.  It  is,  how- 
ever, preferable  to  keep  the  two  solutions 
separate  until  shortly  before  use  (Zeitsch.  anal. 
Chem.  1890,  29,  615). 

The  RochcUe  salt  used  is  best  prepared  by 
dissolving  commercial  cream  of  tutar  in  hot 
water,  rendering  the  liquid  slightly  alkaline  after 
boiling  by  addition  of  sodium  carbonate,  filter- 
ing off  the  precipitated  calcium  carbonate,  and 
crystallising  the  Kochelle  salt  from  the  filtrate. 

Addition  of  small  quantities  of  mineral  acids 
to  Barreswil's  solution  by  lessening  its  alkalinity 
effects  its  reduction,  even  when  it  is  still  alkaline 
to  litmus.  Often  the  action  commences  before 
the  liquid  is  warmed,  reduction  being  completed 
by  gentle  heating.  The  reduction  is  attrilbuted 
to  the  decomposing  action  of  the  mineral  acid 
upon  the  tartaric  acid  (Jovitschitsch.  Ber.  1897, 
2431).  Evidence  of  the  negative  character  of 
the  blue  ion  in  Barreswil's  solution  was  first 


adduced    by    Kahlenberg    (Zeitsoh.    plmikal 
Chem.   1895,   17,  686),  and  later   by  Kuater 
(Zeitsch.  Elektroohem.  1897,  105)  and  Masson 
(Phil.  Trans.  1899,  192,  331). 

Masson  employed  a  solution  as  free  as  possible 
from  alkali,  and  electrolysed  it  in  conjunction 
with  a  solution  of  copper  sulphate,  the  blue  ions 
in  the  two  solutions  travelling  in  opposite 
directions  along  a  tube  containing  a  jelly  solu- 
tion of  potassium  chloride.  The  presence  of  an 
invisible  ion,  probably  tartaric  ion,  accompany- 
ing the  negative  blue  ions,  was  demonstrated  by 
the  formation  of  a  precipitate  at  the  boundary 
of  the  positive  blue  ions,  when  the  negative  ions 
were  still  some  way  off. 

The  constituent  salt  of  the  neutral  Barreswil's 
solution  was  isolated  and  analysed  by  Masson 
and  Steele  (Chem.  Soc.  Trans.  1899, 75, 725),  who 
represented  its  formation  from  cupric  tartrate 
thus: 

5NaOH+4CuC4H40, 

«NatC4H40,+Na,C„HtCu40„-f5HtO 

They  also  obtained  evidence  that  the  excess  of 
alkali  in  Barreswil's  solution,  as  usually  made,  is 
combined  with  the  blue  salt 

F.  BuUuheimer  and  E.  Seits  (Ber.  1899, 
2347 ;  1900,  817)  showed  that  three  classes  of 
cupric  tartrates  exist;  monotartrates,  con- 
taminff  carboxylic  and  hvdrosrlic  hydrogen, 
all  replaoed  by  metal ;  double  salts  consisting  of 
monotartrate,  probably  united  through  copper 
to  a  molecule  of  basic  alkali  tartrate ;  and  a 
third  class  consisting  of  monotartrate  combined 
with  basic  cupric  tairtrate. 

The  salts  in  Barreswil's  solution,  from  their 
general  reactions,  appear  to  belong  to  the  second 
class,  and  compounds  having  the  formula 
C,H«Oi.CuNasK,  and  CaH40itCuNa,K  have 
been  isolated. 

The  neutral  cuprotartrate  of  Masson  (Lc) 
requires  the  addition  of  alkali  in  order  to  form 
the  usual  Barreswil's  solution  with  its  character- 
istic colour. 

Barreswil's  solution  is  not  reduced  by  cane 
sugar,  dextrin,  or  cellulose,  but  is  reduced  by 
dextrose,  Invulose,  maltose,  lactose,  mannose, 
galactose,  arabinose,  gallisin,  aldehyde,  chloral, 
chloroform,  valeraldehyde,  resoroinol,  pyro- 
gallol,  gallotannic  and  trichloracetic  acids,  and  by 
arsenious  acid. 

The  action  of  these  substances  on  the  solution 
is  doubtful  Among  the  products  are  formic, 
acetic,  tartronic,  and  some  acids  of  doubtful 
composition  and  a  gum-like  substance.  Its  use 
is  almost  restricted  to  the  detection  and  estima- 
tion of  reducing  sugars.  For  the  detedum  of 
sugars,  the  clear,  acid-free  liquid  is  heated  with 
two  volumes  of  Barreswil's  solution.  If  one  of 
the  above  reducing  compounds  be  present,  a 
yellow  precipitate  of  cuprous  oxioe,  which 
rapidly  becomes  converted  into  the  orange-red 
or  bright  red  oxide,  is  produced.  The  com- 
position of  the  oxide  whatever  its  colour  may  be 
18  identical,  the  var3ring  colour  being  due  to 
differences  of  subdivision,  depending  upon  the 
conditions  during  precipitation.  Microscopical 
examination  shows  that  as  the  different  cofours 
are  developed  there  is  a  gradual  increase  in  the 
size  of  the  particles  (Fischer  and  Hooker, 
J.  Lab.  and  Clin.  Med.  1918,  3,  6). 

If  the  liquid  to  be  tested  is  much  coloured. 


BARRESWIL'S  OR  FEHLINQ*S  SOLUTION. 


563 


it  mnflt  be  fint  clarified,  u  described  under 
Saochabdisibt.  Wben  the  clarification  baa 
been  performed  with  lead,  an  amount  of  the 
solution  containing  a  known  weight  (2  to  5 
grams)  of  glucose  or  other  body,  estimated,  is 
placed  in  a  100  c.o.  fiask  and  is  treated  with 
siilphnrons  acid  gas,  or  with  a  strong  solution 
of  that  gas,  until  the  whole  of  the  )om1  is  pre 
cipitate^  and,  after  the  addition  of  a  ktUe 
freshly  precipitated,  washed  alumina,  is  diluted 
to  100  C.C.,  agitated  and  filtered. 

Cane  sugar,  when  estimated,  is  first  clarified, 
if  necessary,  and  then '  inverted ' — i.e.  converted 
into  a  mixture  of  dextrose  and  laevulose.  For 
this  purpose,  a  solution  containing  not  more 
than  1  ^m  of  sugar  to  4  ca  of  solution  is 
mixed  with  one-tenui  its  bulk  of  fumins  hydro- 
chloric add,  and  is  heated  to  70**  for  10  to  15 
minutes,  and  finally  neutralised  by  addition  of 
sodium  carbonate. 

Starch  and  starchy  bodies  may  also  be  con- 
verted into  invert  sugar,  and  estimated  by 
Barreswirs  solution.  Two  or  three  strong  flasks, 
each  containing  from  one-half  to  one  gram  of  the 
substance  and  50  or  60  cc.  of  decinormal  sul- 
phuric acid  solution,  are  closed  with  caoutchouc 
corks  carefully  tied  down,  and  are  heated  in  a 
water-bath.  After  4  hours,  one  flask  is  taken 
out  and  contents  neutralised  and  titrated  with 
Barreswil*s  solution  as  hereafter  described,  and 
after  a  further  interval  of  2  hours  the  second  is 
similarly  examined.  If  the  amount  of  sugar 
found  in  the  second  fiask  does  not  exceed  that 
in  the  first,  the  result  may  be  taken  as  correct ; 
but  if  the  quantities  differ  markediv,  the  third 
flask  is  heated  a  further  period  of  from  2  to 
4  hours,  and  then  titrated.  Each  100  parts  of 
invert  sugar  found  represents  90  parts  of  starch. 

In  titrating  solutions  of  these  substemces, 
10  cc.  of  Barreswil*s  solution  is  measured  into 
a  wide  test-tube  and  diluted  to  40  cc,  and 
heated  to  boiliog.  The  neutralised  sugar  solution, 
which  should  contain  not  more  than  one  gram 
per  100  cc,  is  then  run  in  from  a  burette  in 
portions  of  2  cc,  the  mixture  being  boiled  after 
each  addition  until  the  blue  colour  has  nearly 
disappeared.  The  suffar  is  then  added  cautiously 
until  the  Uquid  is  colourless  or  slightly  yellow. 
A  few  drops  of  the  filtered  solution  are  tested 
for  copper  by  sulphuretted  hydrogen  or  by  a 
mixture  of  potassium  ferrocyanide  and  acetic 
acid. 

The  solution  may  be  standardised  for  invert 
sugar  as  follows :  4*75  grams  of  sucrose  are  dis- 
solved in  75  cc  water,  and  5  cc.  of  hydrochloric 
acid  (sp.gr.  1  *188)  added.  The  solution  is  warmed 
to  70^  for  about  7  minutes,  making  a  total  of 
10  minutes'  heating.  After  inversion,  the  acid  is 
neutralised  with  sodium  hydroxide,  and  the 
liquid  diluted  to  1  litre.  10  cc  of  this  solution 
contains  0*050  gram  of  invert  sugar,  and 
should  reduce  10  cc.  of  the  copper  solution 
{see  also  Bomtrager,  Zeitsch.  angew.  Chem. 
1893,  600). 

Experience  shows  that  the  time  occupied  in 
the  analysis,  the  amount  of  excess  of  copper 
present  in  the  solution,  the  concentration  of  the 
Uquid,  and  other  details,  affect  the  result. 
Soxhlet  (Pharm.  J.  [3]  1880-1,  11,  721)  recom- 
mends adherence  to  the  following  process. 
Having  approximately  found  the  strength  of 
the  solution    by    running    the    sugar    solution 


into  50  cc  of  Baiieswil^s  solution  as  above 
until  the  blue  colour  disappears,  dilute  it  until 
containiiuE  about  I  gram  per  100  cc,  and  heat 
50  cc  Barreswirs  solution  with  as  mooh  ot 
the  dQuted  solution  as  should  precipitate  all  the 
copper.  When  the  sugar  estimated  is  invert 
sugar,  grape  sugar,  or  Isvuloee,  the  heatins 
should  oooupv  2  minutes,  while  for  maltose  and 
lactose  4  and  6  minutes  respectively  shook!  be 
allowed.  The  whole  fluid  is  then  filtered  and 
tested  for  copper.     A  third  titration  is  next 

rtif  ormed  with  a  biger  amount  of  the  fluid,  with 
cc  less  of  sugar  (according  to  the  presence  or 
absence  of  copper),  and  the  titrations  are  re- 
peated with  varying  amounts  of  sugar  solution, 
each  time  adding  the  whole  of  that  solution  at 
once,  until  1  cc  more  or  less  would  give  a  filtrate 
free  from  or  containlns  a  trace  of  copper,  after 
which  the  variatk>n  m  the  amount  of  sugar 
solution  IB  decreased.  In  this  way,  the  volume 
of  sugar  solution  required  may  be  determined  to 
0-1  cc  Under  these  conditions,  100  cc  of  the 
mixed  copper  reagent  require  0*475  gram  anhy- 
drous dextrose  or  0*494  gram  of  invert  sugar  for 
complete  reduction.  The  foUowing  may  be 
taken  as  the  weight  of  sugar  capable  of  reducing 

10  cc  of  Barreswil's  solution : — 

crain 

Dextrose,  Isevulose,  or  invert  sugar  0-0500 

Cane  sugar  (inverted)    .         .         .  0*0475 

Milk  sugar  (lactose)       •         •         .  0*0678 

Malt  sugar  (maltose)     .         .         .  0-0807 

Soxhbt  (Lc),  operating  by  his  method  as 
described  above,  has  obtained  the  following 
results.  (His  method  of  '  inverting '  cane  sugar 
has  been  somewhat  objected  to) — 


Wbiqht  ov 

SxrOAB  BXDUCZNO   10  C.O. 

cm 

Babrbswil's  Solution. 

Dilated  with 

Time  of 
heating 

Un- 
diluted 

One 

Two  J  Three 
vols.ofyol8.of 

Four 

(mlDB.) 

▼ol.  of 

vols.of 

00475 

water 

water 

water 

water 

Dextrose 

2 

004825 

0-0488 

0*0402 

00404 

Invert 

lugar 

2 

00404 

005080 

0-0500  0  0514 

00515 

Lievulose 

2 

00613 

006285 

0  0580  0  0686 

00526 

LaeCose 

e 

00076 

Unaffeo 

ted  by  dilution 

0-0676 

Laeto- 

gluoose 
Maltose 

2 

00511 

••               •• 

0-0588 

8to4 

00778 

••               if 

0-0740 

The  titration  of  raw  sugars  and  other 
coloured  commercial  products  is  very  unsatis- 
factory when  potassium  ferrocyanide  Is  used  as 
an  indicator,  mainly  because  the  amino  com- 
pounds present  cause  the  solution  of  much  cuprous 
oxide,  which  then  gives  a  precipitate  with 
potassium  ferrocyanide.  On  this  account,  Indi- 
cators have  been  proposed  which  will  show  the 
presence  of  a  tnce  of  cupric  salt  without 
pevious  filtration,  the  best  of  these  beins 
ferrous  thiocyanate  (A.  R.  Ling,  T.  Rendle,  ana 
G.  a  Jones,  Analyst,  1906,  30,  182 ;  1908,  33, 
160-170),  which  gives  the  characteristic  red 
colour  of  ferric  thiocyanate  when  treated  with 
cupric  salt  solution.  The  reagent  is  prepared 
by  dissolving  1  gram  of  fenous  ammonium 
sulphate  and  1*5  grams  of  ammonium  thio- 
cyanate in  10  cc.  of  warm  water,  adding  2*6  ac 
of  cone,  hydrochloric  acid,  and  completely  re- 
moving all  trace  <4  ferric  salt  by  addition  of  zinc- 


654 


-BARRESWIL'S  OR  FEELING'S  SOLUTION. 


dust.  The  titration  of  the  sugar  solution  is 
carried  out  muoh  as  usual,  ezoept  that  it  must 
be  done  as  quickly  as  possible  to  avoid  oxidation 
(Luur.  J.  Inst.  Brewing,  1906,  12,  No.  I). 

A  modification  of  Barreswil^s  process,  devised 
bv  Pavy,  is  based  on  the  fact  that  precipitation 
of  the  cuprous  oxide  is  prevented  by  the  presence 
of  excess  of  ammonia,  the  solution  losing  its 
intense  blue  colour  and  becoming  absolutely 
colourless  after  the  whole  of  the  copper  has  been 
reduced. 

The  solution  used  is  prepared  by  mixing 
120  CO.  of  Barreswil's  solution  with  300  c.c.  of 
ammonia  (0*880  sp.gr.)  and  400  c.c.  of  12  p.c. 
caustic  soda  solution,  and  diluting  to  1  litre. 
100  CO.  of  this  solution  corresponds  with  10  cc 
of  Barreswil's  solution.  The  huger  quantity  of 
Barreswil's  solution  (120  cc.  instead  of  100  cc.) 
used  to  prepare  this  test  is  required  on  account 
of  the  lower  oxidising  power  of  Pavy's  solution, 
the  action  of  which  on  invert  sugar  is  only  five- 
sixths  of  that  of  Barreswirs  solution.  Its  action 
on  maltose  and  lactose  also  differs  from  that 
of  Barreswil's  solution. 

To  prevent  reoxidation  of  the  decolourised 
solution,  with  reproduction  of  the  blue  colour, 
the  operation  should  be  performed  without  access 
of  air,  by  connecting  the  burette  supplying  the 
sugar  solution  with  a  tube  passing  tlux>ugh  a 
cork  into  the  flask  containing  the  Barre^vil's 
solution,  the  steam  from  which  escapes  through 
another  tube  dipping  beneath  the  surface  of 
mercury.  A  slow  current  of  coal  gas  may  be 
passed  through  the  flask  during  the  operation. 

The  sugar  solution  is  run  into  the  flask,  in 
which  100  c.c.  of  the  copper  solution  has  been 
heated  to  ebullition,  and  the  boiling  is  con- 
tinued until  the  colour  has  disappeared.  Hehner 
(Analyst,  1881,  6,  218)  has  shown  that  alkaline 
tartrates,  carbonates,  and  other  salts  affect  the 
results. 

The  method  is  most  used  in  clinical  chemistry, 
particularly  for  urine  analysis.  It  is  also  of 
great  value  in  studying  the  saccharine  products 
of  enzyme  action,  e«ipecially  as  it  gives  with 
glucose  a  very  mu(!h  lar;^er  *  copper  *  value  than 
with  maltose  (Croft  Hill,  Chem.  Soo.  Trans. 
1898,  73,  634). 

The  most  accurate  method  of  using 
Barreswil*s  solution,  especially  when  the  sugar 
solution  is  unclarified,  consists  in  separating  and 
estimating  the  precipitated  cuprous  oxide.  One 
of  the  many  processes  recommended  is  that  of 
Pavy.  The  BarreswiFs  solution  is  boiled,  in 
slight  excess,  with  the  sugar  solution,  the 
strength  of  which  should  be  about  1  p.c,  and  the 
precipitated  suboxide  is  rapidly  separated  by 
filtering  the  liquid  through  a  funnel  loosely 
packed  at  the  neck  with  glass  wool  or  asbestos. 
The  precipitate,  after  washing,  is  dissolved  in  hot 
dilute  nitric  acid,  or  2  c.c  cone  nitric  acid,  or  a 
mixture  of  dilute  sulphuric  and  nitric  acids,  and 
the  copper  estimated  oy  electro-deposition.  The 
weight  of  copper  obtained  is  multiplied  by  0*5395 
to  obtain  its  equivalent  in  inverted  cane  sugar, 
or  by  other  factors,  which  may  be  calculated 
from  the  tables  given  above,  to  obtain  the 
equivalent  of  any  other  sugar  which  may  be 
estimated. 

Brunner  recommends  solution  of  the  cuprous 
oxide,  filtered  as  above,  in  a  solution  of  pure 
ferric  chloride  or  sulphate  acidulated  with  sul- 


phuric add,  and  the  estimation  of  the  ferrous 
salt  so  produced,  by  titration  with  a  standard 
solution  of  potassium  permanganate  or  di- 
chromate. 

The  cuprous  oxide  can  also  be  weighed 
directly  after  washing  with  alcohol  and  ether. 
It  may  also  be  estimated  as  metallic  copper  after 
reduction  by  hydrogen  or  as  cupric  oxide  after 
ignition  in  porcelain. 

For  the  influence  of  light  on  Barreswil's 
solution,  see  Leighton  (J.  Phys.  Chem.  1913,  IT, 
205). 

BARUS  CAMPHOR  v.  Camfhobs. 

BARUTIN.  Trade  name  for  the  double  salt 
of  theobromine  barium  and  sodium  salicylate ; 
a  white  amorphous  powder  of  sweetish  taste  and 
alkaline  reaction,  sparingly  soluble  in  water. 
Used  in  the  treatment  of  renal  disease.      V. 

STKTHXnO  DBUQS. 

BARWOOD.  Barwood  is  the  wood  of  a 
large,  fine  tree,  Baphia  nitida  (Lodd.),  and  is 
imported  from  the  west  coast  of  Africa,  e.g. 
Sierra  Leone,  Angola,  &c.  In  the  log  ito  physicai 
properties  are  generally  similar  to  those  of 
sanderswood ;  in  the  rasped  condition  it  has  a 
somewhat  brighter  red  colour  and  is  devoid  of 
aromatic  odour.  According  to  Girardin  and 
Preisser,  boiling  water  extracto  about  7  p.c  of 
colouring  matter,  alcohol  about  23  p.c.,  and 
hydrated  ether  about  10  p.c. 

Anderson  (Chem.  Soc  Trans.  1876,  iL  582) 
extracted  ground  barwood  with  anhydrous 
methylated  ether  free  from  alcohol.  By 
spontaneous  evaporation  of  the  concentrated 
ethereal  solution  a  small  quantity  of  baphic  add 
is  deposited  in  the  form  of  tabular  crystals. 
After  further  evaporation,  mixing  the  concen- 
trated extract  with  alcohol,  and  allowing  to 
stand  for  some  days,  there  is  deposited  a  crystal- 
line magma  of  baphiin  contaminated  with  a  solid 
red  colouring  matter  and  some  dark  viscous 
colouring  matter  not  yet  examined. 

After  exhaustion  with  ether  the  wood  is 
extracted  with  alcohol,  and  after  concentrating 
the  solution  it  is  left  at  rest  for  some  lime, 
when  it  congeals  to  a  semi-crvstalline  mass 
which  contains  a  viscous  red  colouring  matter 
and  a  crystalline  constituent  not  examined. 

Baphiin,  Ca^HMO,  (m.p.  about  200^), 
crrstalUses  from  alcohol  in  the  form  of  lustrous 
tabular  crystals  having  an  odour  of  orris  root ; 
from  ether  it  crystalEses  in  tufto  of  needles. 
It  is  insoluble  in  water,  and  very  sparingly 
soluble  in  benzene  or  in  carbon  disulphlde.  In 
alcoholic  solution  it  rapidly  oxidises  on  exposure 
to  air,  producing  orange-red  or  pale  purple 
colours. 

Baphic  acid  Ct4H|.0«  or  C|4H||0i«  is  pre- 
pared by  boilinff  baphiin  with  dilute  caustic 
potash,  and  adding  hydrochloric  acid,  whoi 
it  is  thrown  down  as  a  yellowish-white  pre- 
cipitate. Crystallised  from  ether  it  forms 
wnite  nacreous  scales,  very  soluble  in  ether, 
slightly  less  so  in  alcohol,  and  insoluble  in 
water  (c/.  Santal). 

Baphinitin  Cf^Uffi^  ia  thrown  down  as  a 
crystalline  precipitate  on  the  addition  of  water 
to  the  filtrate  from  the  precipitate  of  lead 
baphate  which  is  formed  on  mixing  alcoholic 
solutions  of  baphiin  and  lead  acetate.  It  is  also 
the  chief  product  of  the  action  of  boiling  dilute 
caustic  potash  on  baphiin.    Baphinitin  forms 


BABYTA  GBEEN. 


656 


white  needles,  soluble  in  alcohol  or  in  ether,  but 
insoluble  in  water;  it  has  the  same  odour  as 
baphiin  but  stronger  (e/.  Pterocarpin). 

Baphiiutane  C^fi^^^ — On  boiling  baphiin 
with  a  strong  aqueous  solution  of  caustic  potash 
without  access  of  air,  an  insoluble  residue  is  left 
which  contains  three  substances :  (1)  baphinitin, 
moderately  soluble  in  alcohol  or  other;  (2) 
baphinitone,  very  readily  soluble  in  these 
liquidi ;  (3)  a  small  quantity  of  an  unexamined 
substance,  m.p.  164*1^,  very  sparingly  soluble 
even  in  hot  alcohol,  and  separating  therefrom 
In  granular  ciystals.  Baphinitone  is  extracted 
from  the  abore-mentioned  residue  insoluble  in 
caustic  potash,  by  treating  it  with  cold  alcohol, 
in  whicn  it  readily  dissolves  along  with  a  very 
small  amount  of  baphinitin.  The  solution  is 
evaporated,  and  the  treatment  with  alcohol  is 
repeated  until  the  crystals  thus  obtained,  after 
diVing  over  sulphuric  acid,  have  a  m.p.  of  about 
88  .  Baphinitone  crystallises  from  alcohol  in 
hemispherical  masses  composed  of  white  lustrous 
radiating  crystals  insoluble  in  water  (c/.  Homo- 
pterocarpin). 

Tribromo-baphinitone  C^^H^p'BTfPm  is  ob- 
tained by  mixing  ethereal  solutions  of  baphini- 
tone and  bromine ;  on  evaporating  off  the  ether 
it  remains  as  a  white  substance,  which  may  be 
purified  by  washing  with  alcohol  or  ether,  in 
which  it  is  almost  insoluble.  It  separates  from  a 
hot  ethereal  solution  in  small  granules,  which 
melt  with  blackening  at  180*2''. 

Baphiin,  baphinitone,  and  substance  (3) 
above  referred  to,  are  all  coloured  orange- 
yellow  by  sulphuric  acid ;  with  nitric  acid  an 
orange-red  colour  is  obtained,  which  changes 
gradually  to  green. 

In  addition  to  the  above-mentioned  sub- 
stances, barwood  contains,  according  to 
Anderson,  at  least  three  colouring  matters. 
Ether  extracts  from  the  wood  two  of  these ; 
one  (a)  which  is  less  soluble,  and  which  tena- 
ciously adheres  to  the  baphiin,  and  another  (6) 
which  is  ciystalline  and  is  easily  removed  from 
it  When  the  extraction  with  ether  i»  com- 
pleted, alcohol  will  dissolve  out  a  third  colouring 
matter  (c).  All  are  insoluble  in  benzene,  ana 
give  purple  lakes  with  lead  acetate,  and  purple 
solutions  with  alkalis. 

O'Neill  and  Perkin  (Ic)  worked  up  barwood 
by  the  same  methods  they  had  previously  applied 
to  aanderswood,  and  isolated  a  colouring  matter, 
corresponding  with  the  santalin  of  this  latter, 
This,  which  consisted  of  a  chocolate-red  powder, 
possessed  the  formula  C|,H|gOB(OCH8)|,  and 
on  heating  commenced  to  soften  at  240°, 
apparently  decomposing,  and  at  270®  had  the 
appearance  of  a  honeycombed  carbonaceous 
mass.  Its  colour  reactions  are  the  same  as 
those  given  by  santalin,  and  it  thus  appears 
probable  that  the  two  compounds  are  identical. 

When  the  crude  colouring  matter  of  barwood, 
dissolved  in  alcohol,  is  poured  into  ether  the 
main  bulk  of  the  santalin  is  precipitated.  The 
ethereal  liquid  now  contains,  in  addition  to  a 
colouring  matter  resembling  dearysanlalin,  two 
crystalline  substances  identical  with  those 
previously  stated  by  Wiedel  (Lc.)  as  present 
in  sanderswood.  To  isolate  santal  the  ether 
solution  is  treated  with  hydrobromic  acid  to 
remove  colouring  matter,  the  colourless  crystal- 
line   residue    remaining    after   evaporation    is 


washed  with  benzene,  and  reorystallised  first 
from  dilute  and  subsequently  from  absolute 
alcohol 

The  analytical  figures  f;iven  by  this  compound 
agree  with  those  obtamed  by  Weidel,  but 
methoxy  determinations  show  that  its  formula 
is  to  be  represented  as  OigH«0,(OOHs),  and  not 
CsHfOt,  as  proposed  by  this  author. 

Santal,  which  seems  to  be  very  similar  to 
Anderson's  baphic  acid,  melts  at  222^-223®, 
is  readily  soluble  in  dilute  alkali  hydroxides,  and 
sparingly  so  in  absolute  alcohol  from  which  it 
crystaUises  in  thin  plates  or  flat  needles.  With 
alcoholic  lead  acetate  it  gives  a  colourless  pre- 
cipitate, and  with  alcoholic  ferric  chloride  a 
violet-black  colouration,  although  this,  aocordina 
to  Weidel,  is  dark  red.  By  the  action  of 
hydriodic  acid  santal  is  converted  into'  saniol, 
probably  C|gH|oOc,  which  consists  of  small 
colourless  flat  needles,  m.p.  270''-273®.  Its 
solution  in  dilute  alkali  hydroxide,  at  first 
colourless,  rapidly  develops  a  reddish-violet 
tint,  and  the  liquid  on  acidification  deposits 
yellow  crystals.  If  the  acid  mixture  is  boiled 
those  become  colourless,  apparentlv  with  re- 
generation of  santol,  for  when  oouected  and 
washed  the  product  can  apain  be  made  to 
produce  the  same  changes.  Santol  thus  luppears 
to  contain  a  lactone  group.  The  hydrobromic 
acid  liquid  obtained  during  the  isolation  of  the 
santal,  was  diluted  with  water,  the  precipitated 
colouring  matter  dissolved  in  a  little  ethyl 
acetate,  the  solution  being  allowed  to  evaporate 
spontaneously.  Minute  crystals  were  slowly . 
cleposited,  and  these  were  collected  and  digested 
with  absolute  alcohol  to  remove  santal.  This 
compound,  evidently  Weidel's  substance 
^i4^ii^4»  <^^  termed  bv  O'Neill  and  Per- 
kin Mmtalonct  is  sparingly  soluble  in  most 
oiganic  solvents,  and  crystallises  from  alcohol 
in  small  red  leaflets.  H  is  soluble  in  dilute 
alkalis  with  a  red  colour,  whereas  alcoholic 
ferric  chloride  colours  it  a  violet  tint.  As 
obtained  by  these  latter  authors  its  complete 
purity  was  doubtful,  but  the  purest  preparation 
obtained  darkened  about  280*^  and  melted  at 
300°.  Its  true  formula  is  probably  either 
C„H,804(0CH,),  or  C„Hi,04(0CH,)„  and  in 
case  this  is  correct  this  compound  has  tiie  com- 
position of  a  deoxysanUdin  monomeUiyl  ether  with 
which  its  general  properties  are  in  harmony. 

Ryan  and  Fitzgerald  (Proc.  Rov.  Irish 
Acad.  1013,  5,  106),  employing  the  following 
method,  have  isolated  homopterocarpin  from 
barwood.  The  ground  material  was  percolated 
for  a  few  days  with  warm  alcohol,  then  with 
ether,  and  finally  with  chloroform.  The  residue 
obtained  by  evaporating  these  extracts  was 
exhausted  with  ether,  the  ethereal  solution 
washed  with  dilute  alkali  and  then  distilled. 
The  product,  when  recrvstalliBed  from  alcohol, 
formed  colourless  acicular  crystals,  m.p.  84*, 
and  was  identical  with  the  baphinitone  of 
Anderson  and  the  homopterocarpin  existing  in 
sanderswood. 

A  fuller  account  of  this  compound,  which 
possesses  the  formula  G«  7Hi,04,  is  given  in  the 
article  describing  the  latter  dyewood.  It  is 
very  probable,  again,  tbat  ^e  bopKinittn 
described  by  Anderson  »»  existing  Vabarwo^  is 
pterocarpin.  A.  Ci.  P. 

BARYTA  GRBBR  V*  l^^^axsi^- 


856 


BARYTBS. 


BARTTBB.  Buite,  or  heavy-spar  (from 
Ba^s,  heavy) ;  a  common  mineral  oonsiBting  of 
Dariiim  sulphate  (BbSOa),  and  orystallising  in 
the  orthorhomhio  system.  The  name  ba^rtes 
is,  however,  sometimes  loosely,  but  incorrectly, 
applied  to  include  both  this  species  and  the 
mineral  witherite  (BaCOa,  9*v*)f  o'  these  are 
occasionally  referred  to  as  '  snlplukte  of  baiytes  ' 
and  'carbonate  of  barytes*  respectively.  The 
reason  for  this  confusion  is  that  the  two  minerals 
are  often  mined  together,  although  they  are  not 
always  put  to  the  same  uses. 

Barytes  is  frequently  to  be  found  as  well- 
developed  crystals,  which  vary  considerably  in 
their  appearance  and  habit.  They  possess  a 
perfect  cleavage  parallel  to  the  base,  and  per- 
pendicular to  this  are  two  prismatic  deavaffes 
parallel  to  the  faces  of  the  primitive  rhombic 
prism,  and  inclined  to  one  another  at  an  angle 
of  TS"*  22y.  With  these  three  directions  of 
perfect  cleavage,  massive  barytes  sometimes 
presents  a  certain  resemblance  to  calcite,  and 
its  hardness  is  also  about  the  same  (H.»=3). 
The  angles  between  the  cleavages  are,  however, 
different ;  and,  further,  baiytes  may  be  readily 
distinguished  from  calcite  by  its  heaviness 
(sp.gr.  4*»),  and  from  both  calcite  and  witherite 
by  not  effervescing  with  acid.  The  massive 
materia]  is  often  white  and  opaque ;  but  crystals 
are  sometimes  transparent  and  colourless,  or  with 
brownish,  greenish,  or  bluish  shades  of  colour. 

Bar3rtes  is  usually  met  with  in  veins,  often 
in  association  with  ores  of  lead.  Some  of  the 
old  lead-mines  of  the  north  of  England,  Derby- 
shire and  Shropshire  are  now  being  reworked 
for  barytes.  A  remarkable  vein  of  barytes, 
consisting  of  pure  white  massive  material  with  a 
thickness  vaiying  from  a  few  inches  to  16  feet,  is 
extensively  worked  in  the  coal-measures  at  New 
Brancepeth  Ck>Uieiy,  near  I>urham  (L.  J. 
Spencer,  Mineralog.  Mag.  1910,  xv,  302). 
Beautiful  crystalliwd  specimens  are  abundant 
in  the  haematite-mines  of  west  Cumberland,  but, 
owing  to  the  brown  or  yellow  colour  of  this 
material,  it  is  of  no  commercial  value.  A  pure 
white  granular  barytes  resembling  marble  in 
appearance  is  mined  at  Dunmanus  Bay,  in  Go. 
Cork.  Important  deposits  of  the  mineral  are 
worked  in  the  United  States,  Germany,  Rhodesia, 
&c.  Baiytes  occurs  abundimtly  as  a  cementing 
material  in  Triassic  sandstones  in  the  Midlands 
of  England  (F.  Clowes,  1889,  1899) ;  and  it  has 
been  recently  suggested  that  this  could  be  easily 
won  by  washing. 

Biuytes  is  mainly  used  in  the  manufacture 
of  paints,  not  only  of  white  painty  but  as  an 
inert  body  in  coloured  paints.  lithophone 
paint  consists  laraely  of  barium  sulphate  with 
zinc  oxide  and  sulphide.  It  is  often  suggested 
that  barytes  is  used  for  adulterating  various 
articles.  Barium  sulphide  and  carbonate  are 
also  prepared  from  baiytes  by  roasting  it  with 
coal,  and  from  the  product,  barium  chloride, 
barium  hydroxide,  &c.,  are  prepared.  In 
preparing  the  crude  barytes  for  the  market,  it  is 
coarsely  crushed  and  hand-picked ;  or  when  mixed 
with  rock  and  dirt,  these  are  separated  b^  agita- 
tion (jigging)  in  water.  Coloured  impurities  are 
sometimes  extracted  by  steam-boiling  with 
sulphuric  acid.  The  purified  material  is  kiln- 
dried  and  reduced  to  very  fine  white  powder  in  a 
ball-mill  provided  with  screens,  or  between  mill- 


stones. The  barytes  flour  so  prepared  still 
consists  of  minute  oiprBtaUine  (cleavage)  parlicka, 
and  it  is  this  that  gives  the  *  tooth '  or  adhesive 
properties  to  the  coarser  baiytes  paints.  The 
finer  qualities  ('  blanc  fixe  *)  are  prepared  from 
precipitated  barium  sulphate ;  and  this  is  also 
used  for  dressing  doth  and  leather,  and  for 
producing  the  smooth  coating  on  '  art '  papers. 
References. — ^For  details  of  British  occur- 
rences, gee  Special  Reports  on  the  Mineral 
Resources  of  Great  Britain,  voL  ii,  Baiytes  and 
Witherite,  Mem.  GeoL  Survey,  2nd  ed.  1910. 
For  the  IJnited  States,  and  a  general  account 
with  bibliography,  see  Mineral  Resources  of  the 
United  States,  for  1915,  U.S.  Geol.  Survey, 
1916 ;  H.  Ries,  Economic  Greology,  New  York, 
1916.  L.  J.  8. 

BARTTIC  WHITE  or  PERHANEMT  WHITB 
or  BLAHC  FIXE  v,  Babittm;  also  PKGmknts. 
BARTTO-CELESTITE  r.  Babitm. 
BARYTOCALCITE,    Barium    and    oaldum 
carbonate,  BaCOs'CaCOs,  ciystallisinff  as  pris- 
matic and  blade-shaped  ciystals  in  we  mono- 
dinic   i^stem.    There   are  ffood  cleavages  in 
three  directions  (the  basal  plane  and  a  prism), 
and   curiously   the  angles   between   these  are 
near  to  the  angles  between  the  thjnee  cleavages 
of  calcite.    The  composition  is  the  same  as  that 
of  alstonite  (g.v.),  but  whilst  alstonite  is  an 
iBomorphous  mixture  of  barium  and  caldum 
carbonates,  baiytocaldte  is  a  double  salt.    The 
mineral  is  white  or  colourless,  and  has  a  vitreous 
lustre.    Sp.gr.  3*65 ;   hardness  4.    Apart  from  a 
doubtful    record    from    Glamorganshire,     the 
mineral  has  been  found  only  in  me  old  Blagill, 
or  Bleagill,^  lead  mine,  near  Alston,  in  Cumber- 
land.   Here  it  occurs  in  considerable  quantity, 
and  was  at  one  time  jnined  as  a  *  low-grade 
witherite.*    Laige  blocts  of  masaiye  material 
with  ciystal-linid  cavities  may  still  be  found 
lyixur  outside  the  mine.    Although  containing 
less  barium  carbonate  (66*3  p.c.)  than  witherite, 
it  may  prove  to  be  of  commeroial  value.    L.  J.  8. 
BASALT.    A  group  of  volcanic  rocks  of 
basic  composition  (SiOg  45-55  p.c),  correspond- 
ing with  tne  plutonic  gabbros.    The  name  'a  one 
of  the  oldest  in  petrography,  being  of  Ethiopian 
origin  and  said  to  signify  a  stone  that  yields 
iron.    Many    of    the    ancient    E^^yptian    and 
Assyrian  monuments  were  carved  in  t^asalt,  and 
it  is  the  material  of  the  famous  Rosetta  stone. 
The  term  is  used  in  rather  different  senses.    A 
quaftyman  often  recognises  amongst  the  diffi- 
cultly-worked igneous  rocks  only  sranite  and 
basalt,  and  commonly  any  dark-coloured  fine- 
grained rock  is  incluaed  under  the  term  baaalt 
or  trap-rock.    Also  petrographers  are  not  agreed 
amongst  themselves  as  to  the  limitations  of  the 
terra.    Strictly,  it  should  be  applied  to  a  rock 
which  has  flowed  as  a  lava  on  the  earth's  surface, 
and  is  composed  of  a  basic  plagiodase-felspar 
(bytownlte  or  labradorite)  and  augittf,  together 
with  small  amounts  of  magnetite  and  ilmenite, 
and  somatimes  glassy  (uncrystallised)  material 
in    the    groundmass.    Sometimes    porphyritic 
crystals  are  pre^nt,  but  usually  the  component 
nunerals   can   only   be   recognised   when   thin 
sections  of  the  rock  are  examined  under  the 
microscope;    the  rock  appearing  compact  and 

>  A  corraptlon  of  the  German  Blel  (lead),  and  a  relle 
of  the  Oerman  miners  emptoved  In  the  Comberiand 
mines  In  the  reign  of  Queen  Elisabeth. 


BASSIA  OILS. 


067 


L 

n. 

111. 

IV. 

V. 

.     49-06 

4711 

46-61 

60-26 

47-98 

.       1-36 

0-78 

1-81 

0-67 

0-68 

.     16-70 

14-33 

16-22 

21-41 

13*34 

.       5-38 

4-88 

3-49 

1-76 

4-00 

.       6-37 

11-06 

7-71 

1-82 

4-24 

.       0-31 

0-21 

0-13 

— . 

trace 

.       8*05 

9-J2 

10-08 

4-48 

9-32 

.       617 

8-46 

8-66 

0-31 

7-01 

.       311 

1-91 

2-43 

6-16 

3-61 

.       1-62 

0-20 

0-67 

11-32 

6-00 

.       1-62 

.1-62 

3-17 

0-96 

2-10 

.      0-46 

0-29 

010 

012 

1-03 

homogeiiAouB  to  the  nnaided  eye.  Other 
mineralB  are  eometimee  present*  particularly 
olivine,  and  we  then  have  the  varietiee  olivine- 
basalt,  hornblende-basalt,  &o.  In  a  less  common 
type  of  alkali-basalt  the  felspars  are  partly  or 
wholly  replaced  by  felspathoid  minerals  (nephe 
lite,  leudte,  and  melilite).  When  the  felspars  are 
wholly  replaced  we  have  the  varieties  nephelite- 
basalt,  lencite-basalt,  &c. ;  and  when  both 
felspar  and  felspathoid  are  present  the  rock  is 
termed  tepnrite  or  basanite,  according  as  olivine 
is  absent  or  present.  A  leacite-basanite,  then, 
consists  of  plagioclase,  angite,  olivine,  and 
leucite.  Analyses  of  some  of  these  types  of 
basaltic  rocks  are  given  below :  I,  average  of 
198  analyses  of  typical  basalts,  including  olivine- 
basalts;  U,  basalt  from  Bisko  Island,  west 
Greenland;  lU,  olivine-basalt  from  the  Isle  of 
Skye,  Scotland;  IV,  leaoite-tephrite  from 
Rome;  V,  lencite-basalt  from  Highwood 
Mountains,  Montana. 

SiOa 

TiO, 

A1,0. 

FeiO, 

FeO 

MnO 

GaO 

MgO 

Na,0 

K,0 

H,0 

P.O. 

As  a  consequence  of  their  volcanic  origin, 
basalts  often  exhibit  a  vesicular  texture,  owins 
to  the  expansion  of  water-vapour  in  the  rock 
before  consolidation;  and  in  these  cavities 
secondary  minerals  (chalcedony,  calcite,  and 
zeolites)  are  often  deposited.  A  well-marked 
columnar  structure,  often  on  a  large  scale,  is  a 
common  character ;  e,g,  at  the  Giants'  Gauseway 
in  Ga  Antrim,  the  Staffa  caves  in  the  Western 
Isles  of  Scotland,  and  in  the  Linz  basalt  quarry 
on  the  Rhine.  It  is  a  dense,  black  rock  weather- 
ing to  brown  or  dark  green.  Sp.gr.  2*8-3-1. 
The  crushing  strength  is  high  (2000-^3000  tons 
per  square  foot) ;  we  absorption  for  water  low 
(about  1  p.o.) ;  and  the  conductivity  for  heat 
considerable,  buildings  of  basalt  being  for  this 
reason  cold  in  winter  and  hot  in  summer. 

Basalts  are  of  world-wide  distribution,  and 
sometimes  cover  enormous  tracts  of  country ; 
e,g.  the  Arctic  region  extending  to  the  Western 
Ides  of  Scotland,  and  the  north  of  Ireland,  the 
I>eccan  traps  of  India,  and  the  lava-fields  of 
Washington,  Oregon,  and  Idaho.  The  rock  is 
quarried  at  many  places  for  road-metal  and 
paving  stones,  and  on  the  Continent  as  a  building 
stone.  But  it  is  to  be  remembered  that  much 
of  the  rock  quarried  under  the  name  of  basalt 
is  included  by  petrographers  under  other  terms, 
particularly  dolerite  and  diabase  (g.v.).  The 
types  of  alkali-basalts  are  less  widely  distributed, 
but  are  abundant  in  central  Italy,  in  the 
neighbourhood  of  Rome  and  Vesuvius,  and  are 
known  in  Germany,  Bohemia,  Wyoming, 
Montana,  and  Brazil  These  are  of  importance 
on  aoooont  of  their  high  content  of  potash 
(aoalyws  IV  and  V  above).  L.  J.  S. 

BASE  OILS  V.  Oils  and  Fats. 


BASIC  BBSSBMBR  STEEL  v.  Iron. 

BASILICON.  Ream  cerate.  A  mixture  of 
oil,  wax,  and  resin. 

BASIL  OIL  V.  Oils,  Esssmtial. 

BASLE  BLUE  v.  Ansms. 

BASSIA  HAHWA  or  HOWRAH  FLOWERS. 
The  flowers  of  B.  (lUipi)  IcUifolia  (Roxb.)  or 
Mahwa,  a  tree  growing  to  the  height  of  60  feet, 
very  abundant  m  Central  India,  are  very  succu- 
lent, and  fall  from  the  tree  in  lai^e  quantities 
everr  night,  a  sio^le  tree  affording  from  200  to 
400  lbs.  of  flowers  m  a  season,  which  lasts  during 
March  and  April  They  are  used  as  an  article 
of  food,  both  cooked  and  raw.  By  fermentation 
and  distillation  they  yield  upwards  of  6  gallons 
of  proof  spirit  per  cwt.  It  is  of  superior  Quality, 
and  when  the  operations  have  been  carefullv  per- 
formed, is  very  much  like  good  Irish  whisky, 
having  a  strong  smoky  and  rather  fcetid  flavour, 
which  disappears  with  age. 

They  have  also  been  used  as  a  cattle  food 
with  success.  It  is  said  that  the  flesh  of  pigs  and 
other  animals  is  much  improved,  acquiring  a 
delicate  flavour. 

The  dried  flowers  have  been  recommended 
as  a  source  of  sugar.  Nesri  found  in  them 
67-9  p.c.  of  glucose,  yielding  26-74  P.O.  of  alcohol 
on  distillation  (Rev.  Ghim.  Med.  Phann.  2,  384 ; 
c/.  von  Lippmann,  Ber.  1902,  35,  1448). 

BASSIA  OIU.  Under  this  name  aie  com- 
prised a  number  of  ofls  belonging  to  the 
genus  Bcusia,  The  most  important  oiu  (or  fats) 
derived  from  Baaeia  species  are :  Mowrah  Seed 
Oil,  Illip^  Butter,  Shea  Butter,  Njave  Oil,  and 
Phulwa  Butter.  For  a  description  of  the  fats 
derived  from  the  kernels  of  different  species  of 
Bassia,  eee  Bull  Imp.  Inst.  1911,  9,  228. 

Mowrah  Seed  Oil  is  the  fat  obtained  from  the 
seeds  of  Basaia  latifoUa  (Roxb.)  (lUipi  kUifolia, 
Roxb.  or  Engler ;  Baaaia  viUaaa,  Wall),  a  tree 
widely  distributed  in  the  northern  provinces  of 
India,  and  especially  in  Bengal.  The  tree  is 
frequently  cultivated  in  East  India,  and  forms 
small  plantations ;  but  even  under  the  incentive 
of  modem  demand  for  a  solid  fat,  the  cultivation 
of  the  Mowrah  Seed  tree  for  the  production  of 
fat  is  not  likely  to  be  taken  in  hand  in  the  near 
future.  The  tree  ffradually  disappears  towards 
Calcutta,  and  is  omy  sparingly  met  with  in  the 
Madras  presidency,  where  its  place  is  taken  by 
Baaaia  longi/olia  \au  below). 

The  kernels  are  1-2  cm.  long,  and  are  enclosed 
in  a  light-brown  shiny  husk.  The  seeds  are  very 
similar  in  appearance  to  those  of  Baaaia  longx- 
folia,  with  which  they  are  frequently  con- 
founded, much  as  the  fat  obtained  from  both 
species  is  frequently  confounded  in  commerce. 
This  is  partly  due  to  the  fact  that  the  two  kinds 
of  fats  are  mixed  together  when  exported  to 
Europe,  a  practice  which  is  greatly  favoured 
by  the  fact  that  both  species  are  known  to  the 
natives  under  such  similarly  sounding  names 
as  Illipi,  Elupa,  Katillipl 

The  kernels  dried  at  100^  contain,  according 
to  Valenta : 
Fat  extracted  (by  petroleum  ether) 

„  soluble  in  al>solute  alcohol 
Tannin         .         .         .         .         • 
Bitter  principle,  soluble  in  water    • 
Starch         .  ,         .         .         • 

Vegetable  mucilaoe 

Albuminous  suba^^ces  toluble  in  water 


61-14 
7-83 
2-12 
O-flO 
0-07 
1-66 
3*60 


658 

Extractiye  sabstanoeB  soluble  in  water 
Insoluble  proteins 

Total  ash 

Fibre  and  loss      .         •         •         • 


BASSIA  OILS.< 


15-59 
4-40 
2*71 

10*29 


In  its  fresh  state  the  fat  is  yellow ;  on  ex- 
posure to  the  air  the  colouring  matter  is  bleached. 
The  oil  can  also  be  bleached  chemicaUy,  as  has 
been  done  by  the  author,  on  a  large  scale. 

The  fat  has  the  sp.gr.  of  0*9175  at  ]5^  melts 
at  about  25-3''-30^  and  solidifies  at  18-5''-22''. 

The  fat  has  a  bitter  aromatic  taste  and  a 
peculiar  odour.  The  iodine  value  of  the  fat  is 
50,  thus  indicating  a  considerable  amount  of 
oleic  acid.  The  chief  constituent  of  the  solid 
fatty  acid  is  palmitic  acid;  arachidic  acid  is 
absent ;  stearic  acid  (13-25  p.c.)  has  been  found 
to  occur  in  specimens  examined  by  Menon. 
The  saponification  value  of  the  commercial 
fats  is  sl^;htiy  lower  than  that  of  fats  having 
the  constitution  due  to  the  fatty  acids  named, 
owing  to  a  somewhat  high  proportion  of  un- 
saponifiable  matter,  viz.  2*34  p.c.  The  fat  ia 
prepared  in  India  in  a  crude  manner,  and  the 
cakes  are  used  as  manure.  Owing  to  a  bitter 
principle  (saponin)  contained  in  the  cakes, 
they  are  unfit  as  food  for  cattle.  Nevertheless, 
the  cake  is  frequently  added  as  an  adulterant  to 
the  so-called  *  native  linseed  cake,'  which,  under 
this  misleading  name,  has  latterly  found  ex- 
tensive sales  on  the  Continent.  The  seeds  and 
the  oil  have  become  an  important  article  of 
commerce.  They  are  imported  to  Europe  in 
irregidar  quantities,  and  are  chiefiy  used  in  the 
soap  and  candle  industries.  Endeavours  have 
aJso  been  made  to  convert  the  fat  into  an  edible 
fat.  In  India,  Mowrah  seed  oil  ia  laigelv  used  as 
an  edible  fat  under  the  name  *  Dolia  oil,*  and  as 
a  medicinal  oil  in  the  treatment  of  skin  diseases 
under  the  name  *  Me  o£L' 

IlUp6  Butter  is  obtained  from  the  seeds  of 
Bassia  longifolia  (Linn.),  a  tree  indigenous  to  the 
southern  part  of  India ;  a  variety  of  this  Basaia 
species  is  Known  as  lUipi  malabarica  (Konig),  in 
the  Western  Ghats  from  Kanara  to  Travancore 
and  the  Anamalais,  where  the  tree  is  found  at 
an  altitude  of  about  4000  feet  The  seeds  bear 
a  close  resemblance  to  those  of  B.  kUifolia, 
but  are  mostly  3-4  cm.  lont;,  and  less  rounded 
than  the  seeds  of  B,  latijolia.  The  average 
weight  of  one  seed  is  1*4  ffrms.  The  kernels 
form  75  p.c.  of  the  seeds,  and  contain  50-55  p.c. 
of  a  white  to  light-yellow  coloused  £ftt.  The  fat 
closely  reeembfes  Mowrah  seed  oil,  but  differs 
from  it  by  its  lower  solidifying  and  melting 
points ;  in  correspondence  therewith  the  iodine 
value  of  the  fat  is  58-64,  %,t.  higher  than  that 
of  B,  latijolia.  The  fat  contains  from  12  to 
20  p.c.  of  stearic  acid ;  arachidic  acid  is  absent 
(Menon). 

Illip!^  seeds  are  imported  into  France  and 
England  (usually  in  adnuxture  with  Mowrah 
seeds),  where  the  fat  is  expressed  for  use  in 
candle- making.  The  proposal  to  employ  the 
fat  as  a  chocolate  &tt  appears  to  be  due  to  the 
confounding  of  true  Illipe  seeds  with  seeds  from 
the  Malayan  Stetes,  erroneously  described  in  the 
market  as  *  Illip€  nuts.* 

Owing  to  the  fact  that  the  term  *■  illiptf  *  is 
applied  to  many  fats,  it  has  been  suggested  by 
Revis  and  Bolton  (Fatty  Foods,  183)  that 
liie  confusion  might  be  prevented  by  adopting 


the  name  *  Latif olia  *  and '  Longifolia  fat  *  for  the 
products  of  the  preceding  species. 

Shea  Butter  is  the  lat  obtained  from  the 
seeds  of  Bassia  Parkii^  De  O.  (Hassk.),  BtUyro- 
spermum  Par  Hi,  [G.  Bon]  (Kotschy),  a  tree 
belonging  to  the  Sapotacecs,  The  tree  was 
first  described  by  Mungo  Park,  who  found  it  in 
the  kingdom  of  Bambara.  Hence  the  fat  was 
known  as  Bambara  fat  and  also  Bamboo!  fat. 
Other  native  names  are  Galam  Butter,  Bambuk 
Butter,  and/ in  French  West  Africa,  Karit4S  Oil. 
The  Shea  Butter  tree,  or  Karite  tree,  which 
resembles  in  appeailuice  the  American  oak,  and 
grows  to  a  height  of  about  40  feet,  occurs  in 
enormous  quantities  on  the  West  Coast  of  Africa, 
and  through  the  centre  of  Africa  in  Hie  French 
and  English  Soudan.  It  is  especiaUy  abundant 
in  the  middle  basin  of  the  Niger,  and  is  as 
characteristic  of  the  region  of  Uie  middle  Niger 
as  is  the  palm  tree  of  the  lower  reaches  of  the 
riven  and  of  the  coast  line.  The  Shea  nut  has 
the  size  and  shape  of  an  ordinary  plum ;  the 
outer  shell  of  soma  specimens  is  coveiid  with  fine 
fibres,  whereas  the  shell  of  nuto  coming  from 
the  middle  Niger  district  has  a  polished  surface. 
Owing  to  the  wide  distribution  of  the  tree,  the 
different  specimens  of  nuto  and  &to  exported 
to  Europe  show  characteristic  differences.  A 
special  variety  appears  to  be  repreeented  hy 
the  specimen  known  as  Bassia  nuoticum  (Kot- 
schy et  Chevalier).  The  seeds  contain  from 
about  32  to  44  p.c.  of  fat»  corresponding  to 
about  49  to  59  p.c.  in  the  kernel,  the  amount 
varying  with  the  origin  of  the  seed.  The  natives 
extract  the  fat  by  pounding  the  kernels  and 
boiling  the  paste  with  water.  The  fat  rises 
to  the  surface  and  is  skimmed  off  into  large 
calabashes,  in  which  it  is  carried  to  the  over 
for  shipment  Since  little  care  is  taken  in  the 
preparation  of  the  exported  oil,  much  of  the 
shea  butter  sent  to  Europe  had  at  one  time  a 
dark-grey  colour,  which  was  considered  to  he 
characteristio  of  shea  butter.  The  fait  used  by 
the  natives  for  their  own  purposes  is,  however, 
prepared  in  a  more  careful  manner,  made  into 
cakes  and  wrapped  round  with  leaves,  so  that 
it  may  keep.  Tnis  fat  is  of  a  white  colour,  and 
keeps  well  for  several  months. 

Shea  butter  plays  a  very  important  part 
in  the  economy  of  the  natives  as  an  ^ble  fat, 
and  also  as  a  burning  oil,  and  for  cosmetic 
purposes.  Attempto  have  been  frequently 
made  to  ship  the  fat  and  the  nuto  in  bulk  to 
Europe.  Owing  partly  to  Uie  careless  prepara- 
tion, and  partlv  to  a  resinous  substance  dissolved 
by  the  fat,  shea  butter  contains  considerable 
amounts  of  unsaponifiable  matter  which  imparto 
to  the  fat  an  indiarubber-like  taste.  This  large 
amount  of  unsaponifiable  matter  (5-9  p.c)  has 
prevented  the  extensive  employment  of  the 
fat  for  soap-making  purposes ;  but  methods  tor 
removing  part  of  the  unsaponifiable  matter 
have  been  devised.  The  fat  is  lUso  used  as  a 
candle  material,  and,  in  the  refined  form,  as  a 
substitute  for  lard. 

The  specific  gravity  of  the  fat  is  0*9177  ;  ito 
melting-point  varies  from  25*^  to  28^  Owing 
to  the  considerable  amount  of  unsaponifiable 
matter,  the  saponification  value  varies  from  171 
to  192.  The  iodine  value  varies  from  56  to  63, 
so  that  the  proportion  of  oleic  acid  in  the  fist 
may  be  estimated  at  about  00  p.o.    The  aathor 


BASTNASITE. 


069 


found  in  a  number  of  shea  butters  from  33  to 
37  p.0.  of  Bteario  acid.  The  remainder  of  the 
fatty  acid  appears  to  consist  of  laurio  add 
(Southoombe,  J.  Soc.  Chem.  Ind  1009,  499). 

NJave  Oil,  Njave  Butter,  Nari  OH,  Noumgou 
Oil,  adjdb  Oil,  is  the  oil  obtained  from  the  seeds 
of  Mimtisopa  Njave  (De  Lanessan),  syn.  Bassia 
Djave  (De  Lanessan) ;  Bassia  toxisperma  (Raoul) ; 
Tieghemdla  africana  (Pierre) ;  BailkmeUa  toxi- 
sperma  (Pierre) ;  BaittoneUa  Djave  (Pierre) ; 
TieghemeUa  JdUyana  (Pierre),  a  tree  belonging 
to  the  family  of  the  SapolacecB,  The  wood  of 
this  tree  is  known  in  commerce  as  *  Cameroon 
mahogany/  The  tree  is  indigenous  to  West 
Africa,  the  Cameroons,  Gaboon,  and  Nigeria, 
and  fumisheSy  like  most  trees  belonging  to  the 
SapolacecB,  guttapercha.  The  Suits  are 
known  in  commerce  as  '  Mahogany  nuts  * ;  in 
the  Gold  Coast  Colony  they  are  tei;ped  *  Abeku  ' 
and  *  Bako '  nuts.  The  weight  of  the  nuts 
varies  between  10  and  21*6  grams,  one- third  of 
which  is  made  up  by  the  sheU.  The  kernels 
contain  43-64  p.c.  of  a  white  fat,  which  the 
natives  (the  Jaundea  and  the  Ngumbaa)  prepare 
by  drying  the  seeds  over  fire  and  breaking  the 
shell  with  stones.  The  kernels  are  then  pounded 
in  a  mortar  or  comminuted  by  rubbing  oetween 
stones.  The  mass  is  next  boiled  out  with 
water,  the  fat  is  skimmed  off  by  hand,  and 
freed  from  the  bulk  of  water  by  squeezing 
between  the  hands,  and  then  subjecting  it  to  a 
somewhat  stronger  pressure  in  baskets,  by 
heaping  stones  on  the  mass.  By  this  process 
an  extremely  poisonous  saponin,  contained  in 
the  fresh  seeds,  is  completely  removed,  so  that 
the  fat  can  be  used  for  edible  purposes.  In 
case  the  seeds  should  be  expressed  on  a  large 
scale  the  press  cakes  would  retain  the  poisonous 
substance,  and  hence  be  valueless  as  a  feeding 
cake  (Der  Tropenpflanzer,  1910,  29),  unless  the 
saponin  be  removed  C4>mplete]y  by  boiling  out 
with  water.  But  even  if  this  process  were 
feasible,  a  considerable  amount  of  nutritive 
substances  would  be  removed  thereby.  The 
economic  prospects  of  the  seeds  are,  there- 
fore, still  doubtful;  nevertheless,  the  exports 
from  the  German  Cameroons  have  increased 
from  3  tons  in  1906  to  183  tons  in  1908.  The 
fat  solidifies  at  about  21**,  and  has  an  iodine 
value  of  about  65. 

Phnlwa  Butter  is  the  fat  expressed  from  the 
kernels  of  Baasia  (lUipi)  butyracea  (Roxb.),  the 
'Indian  butter  tree,'  which  is  indigenous  to 
the  Himalayas.  The  seeds,  known  as  'phul- 
wara,*  are  smaller  and  thinner  than  thoste  of 
B,  kUifoiia  and  longifolia.  The  average  weight 
of  one  seed  is  one  gram.  The  kernels  form 
67*5  p.c.  of  the  total  seed ;  they  contain  50-66 
p.c.  of  a  white  fat,  having  the  consistence  of 
lard.  Phulwa  Butter  is  one  of  the  most  im- 
portant foodstuffs  amongst  the  natives  of  the 
North- West  Provinces,  on  account  of  its  pleasant 
odour  and  agreeable  taste,  and  is  frequently 
used  to  adulterate  Ghee.  The  butter  is  also 
highly  valued  by  the  natives  as  an  ointment 
when  properly  perfumed.  The  melting-point 
of  the  fat  is  39^,  and  its  iodine  value  42^.  Stearic 
acid  is  absent  (Menon). 

Less-known  Bassia  Oils  are :  Payena  Oil  or 
Kansive  OH,  from  Payena  oleifera  (Chemical 
Technology  and  AnalysiB  of  Oils,  Fats,  and 
Waxes,  uT  SOO),  and  Kaiio  OiT»  from  Baaaia 


MaUleyana,  which  solidifies  at  UMS*"  and  has 
an  iodine  value  of  63-65  (Brooks,  Analyst. 
1909,  207).  J.  L. 

BASSORIN  V.  Gums  and  Gum  Tbaoaoakth. 

BASSWOOD  OIL.  An  oil  from  TUia  ameri- 
cana,  resembling  cotton-seed  oil,  and  consisting 
of  glycerides  rich  in  butyric  acid  (Wiechmann, 
Amer.  Chem.  J.  1895,  17,  306). 

BAST  FIBRES.  Elongated  narrow  plant- 
oeUs  that  form  strengthening  tissue  in  stems  and 
leaves,  especially  in  connection  wiUi  the  fibro- 
vasoular  bundles,  but  not  belonging  to  the  wood. 
The  raw  material,  bast  or  bast-like  fibre,  used  for 
textile  purposes  or  for  the  manufacture  of  paper, 
ropes,  and  the  like,  ia  of  varied  nature  and 
source,  but  is  always  characterised  by  the 
abundance  in  it  of  bast  fibres.  It  may  be 
composed  of  a  number  of  fibro-vascular  bundles, 
or  one  such  bundle  {t.g.  coco-nut  fibre),  or  part 
of  fibro-vascular  bundle  (e.jr.  fibre  from  leaves  of 
monocotyledons),  or  merely  a  bundle  of  true 
bast  fibres  (from  the  fibro-vascular  bundles  or 
bark  of  dicotyledonous  stems). 

A  typical  bast  fibre  has  a  thick  wall,  with 
slit-like  oblique  pits,  and  a  relatively  small 
lumen.  The  ends  usually  taper  to  fine  points, 
but  may  be  blunt  or  even  branched.  The  cell- 
wall  varies  in  thickness  in  different  species,  from 
comparatively  thin  to  extremely  thick,  and  may 
vary  in  the  same  fibre,  so  that  the  lumen  is  alter- 
nately wider  and  narrower.  When  tlie  wall  is 
veiy  thick  the  lumen  is  reduced  to  a  line,  and 
may  be  locally  evanescent.  There  are  similar 
differences  in  we  width,  lensth,  and  strength  of 
the  raw  material  and  inmvidual  bast  fibre. 
The  colour  varies  from  the  usual  whitish-grey  or 
ffreen  or  yellow,  through  yellow  and  brown  to 
black. 

The  cell- wall  is  mainly  composed  of  celluloses 
and  in  certain  species  (flue,  Caldtropisgigantea, 
and  others)  is  entirely  soluble  in  ammoniacal 
cupric  oxide,  and  gives  tiie  colour  reactions  for 
celluloses ;  but  the  bast  fibres  of  certain  other 
species  (jute,  hemp,  esparto,  and  others)  show 
lignification,  and  give  corresponding  colour 
reactions. 

Bast  fibres  in  commercial  use  are  mainly 
obtained  from  comparatively  few  alliances  and 
families  of  dicotyledons,  and  genera  of  mono- 
cotyledons, namely,  Malvales  (Malvaoen), 
Tiliacefe,  Sterculiacete,  Urticales  (Moracen, 
Urticacee,  Ulmacen),  L^uminossB,  Linaces, 
Apocynac»e,  and  Asclepiaxucee,  Boraginacee ; 
Agave  and  Fourcroya,  AM,  Bromelia,  Sanaeviera, 
Muaa,  Stipa,  Pandanua,  and  several  palms. 
{See  articles  on  any  of  these,  and  Juts  and 
HsMF.  For  a  full  authoritative  account'  of 
vegetable  fibres,  aee  Wiesner,  Die  Rohstoffe  des 
Pflanzenreichs,  1903,  Bd.  ii.  167-463.) 

BASTNASITE.  A  fluocarbonate  of  cerium- 
metals  (CeF)COs,  long  known  as  small  yellowish 
masses  with  greasy  lustre  embedded  between 
aUanite  crystius  at  the  Bastnas  mine,  Riddar- 
hyttan,  Sweden.  It  has  also  been  observed  as 
an  alteration  product  of  tysonite  (CeF.)  in  the 
granite  of  the  Pikers  Peak  region  in  £1  Paso  Co., 
Colorado.  Recently  large  masses  have  been 
found  in  Madagascar  in  we  weathered  debris  of 
pegmatite  at  Torendrika  to  the  east  of  Ambositra 
and  near  Antsirabe.  These  have  the  form  of 
rough  hexagonal  prisms  o!  a  yellow  to  reddish- 
brown  colour.    ^106  orystalB  show  an  easy 


060 


BA8TNA8ITE. 


■epuatiQD  panllel  to  the  basal  plane  on  which 
the  liiBtre  is  then  po^tfly*  otherwise  it  is 
greasy  in  character.  The  CTystals  axe  optically 
uniaxial  and  positiye.  filp.gr.  4*048.  The 
mineral  is  difficultly  attacked  by  hydrochlorio 
acid,  but  is  decomposed  by  sulphuric  acid,  with 
evolution  of  carbon  diozioe  and  fluorine.  It  is 
infusible  before  the  blowpipe.  L.  J.  & 

BATATAS,  or  Sweet  Potatoes,  the  tubers  of 
Imomma  baUUaa  or  Baiata  edulis,  a  convolvulus- 
like  plant,  usually  with  purple  flowers,  growing 
freely  in  tropical  and  sub-tropical  countries. 
The  tubers  are  sometimes  of  great  size — ^up  to 
12  lbs.  or  more  in  weight. 

It  can  be  propagated  by  cuttings  or  by  the 
tubers,  and,  once  estabfished,  often  jrields 
several  crops  in  succession.  An  average  crop  is 
about  6  tons  per  acre.  Light  friable  soils  are 
most  suitable. 

Average  composition  of  sweet  potatoes  and 
their  vines: 

Bolubia 
carbohy- 
drates  Fibre   Afh 
24-7        1-3     1-0 
29-3      13-6    5-8 


Tubers 
Vines 


Water 
711 
4L-6 


Protein  Fat 
1-6  0-4 
7-6      21 


A  more  detailed  analysis  of  the  tubers  as  grown 
in  Monte  Video,  is  given  by  Saco  (Bied.  Zentr. 
1883,  337) : 

Pectio 
Water  Protein  Oluoose  Mucilage  add  Starch  Fibre  Ash 
67-0    0-66      0-3      116      127      13      10    1-0 
to       to       to  to      to 

68-2    0-64      4-0  15     178 

The  sweet  potatoes  are  hugely  used  as  food, 
and  also  in  the  manufacture  of  aioohoL 

According  to  Stone  (Ber.  1890, 23, 1406),  they 
contain  from  1-5  to  2-0  p.c.  of  cane  suffer,  and 
baking  converts  the  starch  into  the  soluble  form 
and  hydrolyses  the  cane  sugar.  The  tops  of 
sweet  potatoes  are  sreedily  eaten  by  farm 
animals,  but  diould  be  used  with  care,  since 
they  sometimes  contain  a  poisonous  cyanogetic 
glucoside.  Amounts  of  hydrocyanic  acid,  vary- 
ing from  0*014  to  0*019  p.c.  of  the  green  material, 
have  been  found.  Sweet  potato  vines  have 
often  proved  fatal  to  piffs  in  Queensland. 

Hasselbring  and  Hawkins  (J.  Agric.  Research, 
1915,  5,  543)  state  that  the  amount  of  sugar  in 
the  tubers  is  comparatively  small  until  alter 
th^  are  harvested ;  but  when  they  are  cut  off 
from  connection  with  the  leaves,  the  starch  is 
transformed,  first,  into  reducing  sugars,  and 
ultimately  into  sucrose.  The  reaction  proceeds 
rapidly  at  high  temperatures,  but  soon  reaches 
an '  end-point,  while  at  lower  temperatures  the 
change  is  slower,  but  ultimately  proceeds  further. 

H.  I. 

BATH  BRICK.  A  brick  made  from  deposits 
of  silicious  and  calcareous  earth  at  Bridgwater, 
Highbridffe,  and  elsewhere,  and  used  for  polish- 
ing metau. 

BATH-METAL.  An  alloy  of  copper  and 
zinc,  containing  a  larger  proportion  of  copper 
than  ordinary  brass,  viz.  83  p.c.  copper  to  17  p.c. 
zinc ;  sp.gr.  8*451 ;  fracture  crystalline,  and 
colour  yellowish-red. 

BATHYCHROIIE  r.  Goloub  and  Ghsmioal 
OoNsnTimoN. 

BATI8T.  A  material  oonsisting  of  cotton 
impregnated  with  caoutohouo  on  one  or  bothl 


sides,   largely   used  in  the  French  army   for 
compresses  and  antiseptic  dressings. 

BAUXITE.  A  clay-like  aluminium  hydroxide 
first  noticed  1^  P.  iBerthier  in  1821  {alumine 
hffdraiie  dea  JBeaux),  and  named  beauxite  by 
A.  Dufr^noy  in  1847,  and  bauxite  by  H.  Sainte- 
Claire  Deville  in  1861 ;  this  name  being  from 
the  village  Les  Beaux,  or  Les  Baux,  near  Aries, 
dep.  Bouches-du-Bhdne,  in  the  south  of  France, 
where  the  material  was  found.  This  material 
came  to  be  regarded  as  a  mineral  species  with 
the  composition  AltO|,2HsO,  correspondmg 
with  A1jO„  73*0 ;  and  11,0,  26*1  p.c  ;  that  is, 
intermediate  between  the '  definite  crvstalliaed 
species  diaspore  (AlaO,,HtO)  and  hyorargillite 
or  gibbsite  (AlgOt^SHaO).  It,  however,  varies 
widely  in  composition,  owing  to  intermixtiue 
with  quart£-sand,  clay,  and  iron  hydroxide, 
and  it  passes  insensibly  into  clays,  iron-ores, 
and  laterite.  The  variations  shown  by  different 
analyses  are  :  A1,0,,  30*3-76-9 ;  HaO,  8*6-31*1 ; 
Fe,0„  01-48-8 ;  SiO„  1*1-41*6  ;  TiO„  l*6-4'0 
(from  table  of  analyses  quoted  by  O.  P.  Merrill, 
The  Non-metallic  Minerals,  New  York,  1910). 
(For  other  analyses  of  Frcoich  bauxite,  see  H. 
Araandanx,  Gompt.  rend.  1909,  cxlviii,  936, 
1115  ;  Bull  Soc.  fran9.  Min.  1913,  xxxvi,  70.) 

The  material  never  shows  any  indications 
of  crystalline  structure,  being  always  com- 
pact or  earthy,  or  often  with  a  conoretionaiy 
(pisolitic  or  oolitic)  structure.  In  colour  it 
ranges  from  white,  through  creamy  and  yellow, 
to  brown  and  deep  red..  Under  the  microscope 
it  shows  only  optically  isotropic,  flocculent 
grains.  Bauxite  is  thus  no  doubt  a  mixture 
of  colloidal  aluminium  hydroxides  (for  which 
the  mineralogical  name  kliachite  has  been 
proposed  by  F.  Comu,  1909,  and  sporoffelite 
oy  M.  Kilpati6,  1912)  with  various  iron  hydr- 
oxides, clays,  &c.,  and  possibly  also  the  crystalloids 
diaspore  and  hydrargillite ;  and  it  is  thus  rather 
of  the  nature  of  a  rock  than  a  simple  minemL 

In  its  mode  of  occurrence,  and  no  doubt  also 
in  its  mode  of  origin,  it  also  shows  wide  differ- 
ences. The  extensive  deposits  in  the  south  of 
France  have  the  form  of  beds  interstratified  with 
limestones  of  Cretaceous  age,  or  of  irregular 
pockets  in  the  limestone.  Those  of  Go.  Antrim 
and  of  the  Vogelsbeis  and  Wee^terwald  in 
Germany,  are  associatea  with  laterite,  and  are 
interbedded  with  basaltic  lava-fiows.  In  Ar- 
kansas the  bauxite  deposits  occur  only  in 
Tertiary  areas  in  the  neighbourhood  of  eruptive 
syenites,  while  in  Alabama  and  Geonna  they 
overlie  ancient  sedimentary  rocks.  The  fre- 
quent presence  of  pisolitic  structures  in  the 
material  and  its  association  with  Hmestones,  has 
led  to  the  suggestion  that  bauxite  has  been 
deposited  by  hot  springs  containing  aluminium 
salts  in  solution  (probably  aluminium  sulphate 
from  the  decomposition  of  pyritous  shales), 
where  these  have  come  into  contact  with  lime- 
stone rocks.  On  the  other  hand,  the  material 
associated  with  laterite  and  basalt  has,  no 
doubt,  been  produced  by  the  weathering  under 
special  conditions  (the  agency  of  bacteria  has 
been  suggested)  of  basalt  or  of  other  igneous 
and  crystalline  rocks.  (For  papm  on  the 
constitution  of  bauxite  and  laterite,  see  M. 
Bauer,  Jahrb.  Min.  1898,  ii,  163;  T.  H 
Holland,  Geol.  Mag.  1903,  59;  A.  Laoroix, 
Nouv.    Archives   du    Mus^    Pkris»    1914,    v^ 


BEAN. 


661 


reviewed  by  L.  I-u  Fennor,  Geol.  Bia^.  1915; 
G.  A.  J.  Cole,  The  Interbaaaltic  Rocks  (Lron  Ores 
and  Bauxites)  o!  Noiih-East  Ireland,  Mem.  GeoL 
Survey,  Ireland,  1912;  H.  Ries,  Economic 
Geology,  New  York,  1916;  W.  C.  Phalen, 
Mineral  Resouroes  of  the  United  SUtes,  for 
1915,  1916,  ii,  169.) 

The  alum- clay  or  bauxite  mined  in  Co. 
Antrim  is  all  sent  to  the  aluminium  works  at 
Foyers  and  Kinlochleven  in  Scotland.  In 
France  the  present  source  of  supply  is  mainly 
in  dep.  Var;  and  in  America  the  production 
is  confined  to  the  states  of  Alabama,  Geonpa, 
and  Arkansas.  The  French  bauxite  is  roughly 
divided  into  three  classes:  (1)  white  bauxite, 
with  60  p.c.  alumina,  not  more  than  4  p.c.  iron, 
and  no  silica, — this  being  used  for  the  manu- 
facture of  aluminium  salts  and  alum;  (2)  red 
bauxite,  with  60  p.c.  alumina  and  3  p.c  silica, — 
used  for  the  manufacture  of  aluminium ;  (3)  a 
special  kind  of  white  bauxite,  with  46  p.c. 
alumina,  a  trace  of  iron,  and  much  silica, — used 
for  making  refractory  bauxite  bricks.  The 
greater  pait  of  the  material  is  used  in  the 
manufacture  of  aluminium,  but  in  America 
large  quantities  are  fused  in  the  electric  furnace 
to  produce  artificial  corundum,  which,  under  the 
name  of  alundum,  is  largely  used  as  an  abrasive 
agent.  L.  J.  S. 

BAVAUTE  V.  Thusimoitb. 

BAY,  BAY  OIL  v.  Laubus  nobius. 
BAYBERRY  TALLOW  v.  Waxes. 
BAYER'S     ACID,     2Naphthol.8.sulphonic 
acid.     F.  Nafhthalxkb. 

BAY-LEAF  OIL  v.  Oils,  Essbntul. 
BAY-SALT  V,  Sodium  ohlobidb. 
BAZILLOL.    Trade  name  for  a  preparation 


of  crude  carbolic  acid.     Used  as  a  disinfectant 

BDELUUM  V,  Gum  bbsins. 

BDELUUM  RESIN  v.  Rbszns. 

BEAN.  The  name  given  to  many  seeds 
which  resemble  in  size  and  shape  the  ordinary 
kidney  bean.  Thus  the  seeds  of  coffee,  cocoa, 
castor,  &c.,  are  often  known  as  'beans.* 
Usually,  however,  the  term  is  restricted  to 
seeds  of  various  leguminoam. 

The  most  important  species  of  beans  are : 

(1)  Adxuki  beans  {Phaseolus  radicUua), 

(2)  Field  or  horse  beans,  of  which  the  broad 
bean  is  a  variety  ( Vicia  Jaha). 

(3)  French  or  kidney  bean  {Phasedui 
vulgaris). 

(4)  Java  or  Lima  bean  {Phaseolus  lunatus). 
(6)  So^  or  Soja    bean  {Qlycine  hispida  or 

8qja  hisptda). 

(6)  Velvet  bean  {Mucuna  uiilis), 

(7)  Garob  or  locust  bean  {Ceratonia  sUiqua). 

In  chemical  composition  beans  are  remark- 
able for  the  large  proportion  of  albuminoid 
matter  which  they  contain.  They  thus  possess 
high  nutritive  value  as  foods. 

In  some  cases  the  seed  only  is  eaten,  either 
sreen  as  in  broad  beans,  or  dried  as  in  haricot 
Beans,  which  are  a  variety  of  PhaseoluB  vulgaris. 
In  oUiers,  e.g.  in  the  kidney  bean,  the  whole 
pod,  in  the  unripe  condition,  is  eeten ;  whilst  in 
the  case  of  the  carob  bean,  the  dried  pod  rathor 
than  the  seeds  b  the  valued  product.  The 
velvet  bean  is  usuaUv  grown  lor  its  foliage, 
either  for  making  into  hay  for  cattle  or  for  green 
manuring. 

In  the  following  table  are  given  analyses 
of  various  beans,  as  far  as  possible  of  the 
products  as  they  are  usually  consumed  as 
food: — 


(1) 

(«) 

(») 

(*) 

(6) 

(«) 

(7) 

(8) 

(•) 

Water 

13* 

87-3 

IM 

68-6     14*4 

lOO 

16-0 

9*3 

19-7 

Protein 

231 

2-2 

16-9 

71 

23-9 

33-2 

17-2 

13-3 

6-6 

Fat 

2-3 

0-4 

1-8 

0-7 

1-6 

17-6 

2-2 

2-6 

0*8 

Soluble  carbohydrates 

Gmde  fibre        .... 

66-6 
3-9 

}  9-4 

671 

22-0| 

49*3 
7-6 

30-2 

28-9 
'29TS 

39-4 
27-6 

39-6 
7-8 

Ash           .... 

3*6 

0-7 

41 

1-7 

3-2 

4-7 

6-2 

7-8 

2-6 

Undetermined    .... 

— ~- 

•"" 

■~" 

"■" 

"~" 

^^ 

*"~ 

^~" 

241 

(1)  Phaseolxis  vulgaris,  dried  seeds,  as  used  as 
haricot  beans. 

(2)  Phaseoius  vulgaris,  green  pods,  as  used  as 
kidney  beans. 

(3)  Phaseoius  lunatus,  dried. 

(4)  „  „       green. 
(6)  Vicia  faba,  dried, 

(6)  Soja  hispida,  dried  seeds. 

(7)  „        „      hay. 

(8)  Mucuna  tUilis,  hay. 

(9)  Ceratonia  sHiqua,  whole  pod. 

The  proteins  of  beans  were  thought  to  con- 
sist largely  of  legumin,  or  *v^etable  casein,* 
firet  obtained  from  them  by  Einhof  in  1806, 
but  Hoppe-Seyler  has  shown  that  the  vegetable 
casein  is  produced  by  the  action  of  the  alkali 
used  in  extraction  upon  the  globulins  and 
albumins  present  in  the  seeds. 

The  proteins  of  Phaseoius  vulgaris  are  chiefly 
phaseohn,  a  globulin  containing  16*45  p.c.  N  and 
0*6  p.c.  S,  and  phaselin  (Osborne,  J.  Amer. 
ChenL    Soa    1894,    16,    6.33).      In    Phaseoius 

Vol.  L— T. 


radiatus  are  present  phaseolin  and  another 
globulin  containing  16*31  p.c.  N  and  0*88  p.c.  S 
(Osborne  and  Campbell,  J.  Amer.  Chem.  Soo. 
1897,  19,  509).  In  Vicia  f aba,  the  same  investi- 
gators found  legumin,  vicilin,  l^umelin,  and 
a  proteose  (same  Journal,  1898,  20,  393).  In 
Soja  hispida  they  found,  as  the  chief  proteid, 
a  fflobuJjn  resembling  legumin,  but  containing 
twice  as  much  sulphur,  for  which  they  propose 
the  name  glycinin.  Legumelin,  a  trace  of  a 
proteose,  and  a  globulin,  probably  identical  with 
phaseolin,  were  also  present  {Lc.  20,  419). 

The  nitrogen- free  extract  of  soja  beans  con- 
tains the  following  substances  (Street  and 
Bailey,  J.  Ind.  £ng.  Chem.  1915,  7,  863); 
galaotans  4*86  p.c. ;  pentosans,  4*94  p.c. ; 
organic  acids  (as  citric  acid),  1*44  p.c. ;  invert 
sugar,  0*07  p.o. ;  sucrose,  3*31  p.c. ;  rafiinoEO, 
1*13  p.a  ;  staroh,  0*60  p.c. ;  cellulose,  3*29  p.o. ; 
hemicelluloses,  0*04  p.c. ;  dextrin,  3*14  p.c. ; 
waxes,  tannins,  &c.  (by  diff.),  8'(X)  p.c.  The 
same  investigatorB  found  soja  beans  to  contain 

2  o 


m 


BEAI^. 


the  following  enzymes:  urease,  amylase,  a 
glucosicle'Splitting  enzyme,  s  protease,  a  perozy- 
dase,  and  a  lipase. 

According  to  Fkurent  (Compt.  rend.  1898, 
126,  1374),  bean  flour  contains  31  p.c.  of  nitro- 
genous matter,  comprising  legumin,  18*9  p.c. ; 
vegetable  albumin,  0*2  p.c. ;  glutenin,  9'5  p.c. ; 
and  gitadin,  2'4  p.c. ;  and  has  been  used  to  add 
to  wheaten  flour,  since  the  addition  of  2  or  3  p.c. 
to  the  latter  increases  the  ratio  of  glutenin  to 
^liadin  in  the  mixture,  and  thus  in  many  cases 
improves  the  flour  for  bread  making.  The 
flour  made  from  haricot  beans  contains  starch 
as  ovoid  grains  with  distinct  elongated  or 
fissured  hila,  and  square  or  rectangular  cells 
containing  prismatic  cxystals  of  calcium  oxalate. 

The  fat  of  beans  contains  choline,  cholesterol, 
and  glvcerides  of  valeric,  oleic,  and  palmitic 
acids,  but  no  stearic  acid  (Jacobson,  S^eitsch. 
physioL  Ohem.  1889,  13,  32).  According  to 
Kosutany  (Landw.  Versuchs-Stat.  1900,  64, 
463),  bean  oil  resembles  olive  oil  in  appearance, 
has  a  sp.gr.  of  0'967,  Reichert-Messef  number 
2*46,  iodine  number  (HiibL)  119*9,  and  contains 
much  lecithin  and  sulphur.  Stanek  (Zeitsch. 
physiol.  Chem.  1906,  48,  334}  found  both  betaine 
and  choline  in  horse  beans. 

Several  varieties  of  beans  contain  a  cyano- 
genetic  glucoside.  In  Phaseolua  lunaitis,  Dunstan 
and  Henry  (Proc.  Boy.  Soc.  1903,  72,  285)  found 
a  glucoside  which  they  named  phaseolunatin 
CioUifOfN,  yielding  dextrose,  prussio  acid,  and 
acetone  on  hydrolysis.  The  wild  plant  contains 
it  in  much  larger  quantity  than  the  cultivated 
one.  From  haricot  beans  Tatlock  and  Thomson 
(Analyst,  1906,  31,  249)  obtained  from  0-001- 
9 '009  p.c.  of  hydrocyanic  acid.  Most  of  the 
oyanogen  compound,  and  the  whole  of  the 
enzyme  which  nydrolyses  it,  are  destroyed  by 
boiling. 

The  oarob  or  locust  bean  is  remarkable  for 
the  large  amount  of  sugar  (cane  sugar  23  p.c., 
glucose  11  p.o.)  contained  in  the  pod,  while 
the  seed  contains  a  carbohydrate,  caroubin, 
a  white,  spongy,  friable  substance,  of  the  same 
composition  as  cellulose  (Effront,  Compt.  rend. 
1897,  125,  38),  which  yields  in  contact  with 
water  a  very  syrupy  liquid  or  jelly,  3  or  4  grams 
of  the  substance  being  sufficient  to  convert  a 
litre  of  water  into  a  thick  syrup.  Caroubin 
might  be  used  with  advantage  in  the  prepara* 
tion  of  nutrient  media  for  bacteriological  work. 

It  has  been  introduced  under  the  name  of 
'  tragasol '  as  a  gum  for  sizins,  colour  printing 
and  dyeing  (J.  Soc.  Chem.  Ind.  1894,  410,  and 
1896,  112). 

Effront  (Compt.  rend.  1897,  125,  309) 
states  that  by  hydrolysis,  either  by  dilute 
acids  or  the  enzyme  caroubinase,  present  in  the 
seeds,  caroubin  yields  a  sugar,  which  he  ca  Is 
oaroubinose,  resembling  dextrose,  but  with  lower 
rotatory  power. 

Van  Ekenstein  (Compt  rend.  1897, 125,  719), 
however,  finds  this  sugar  to  be  identical  with 
flE-mannose.  So,  too,  Sourquelot  and  Hcrissoy 
find  that  the  action  of  dilute  acid  upon  the 
oarob  seed  yields  a  'mixture  of  mannose  and 
galactose  so  that  caroubin  apparently  consists 
of  mannans  and  galaotans  (dompt.  rend.  1899, 
129,  228  and  391).  For  analyses  of  commercial 
carobs  v.  Ballandi,  J.  Pharm.  chim.  1904, 19, 569. 

All  species  of  beans,  like  other  leguminose. 


serve  as  hosts  for  the  tabercle-forming,  nitrogea- 
fixing  organisms  {Baeilhu  radicoeaia),  and  thus, 
under  suitable  conditions,  are  independent 
of  supplies  of  combined  nitiogen  in  the  soiL 
Beans  are  therefore  sometimes  used  for  enriching 
soils  in  combined  nitrogen,  being  employed  for 
green  manuring,  though  the  root  dAris  of  a  crop 
of  beans,  even  after  the  removal  of  the  seed  and 
haulms,  often  effects  this  object  to  a  oonsiderahle 
extent.  H.  L 

BEAN  OIL.    See  Soya  bean  oii«. 

BEARBERRY  LEAVES.  The  dried  leaves 
of  Arctostaphylos  leva-ursi  (Spreng). 

BEBEERIIIE  (beberine,  bilnrine)  is  a  name 
which  has  been  applied  variously. 

1.  Kaclagan  (Annalen,  1843,  48,  106;  with 
Tilley,  1845,  55,  105)  first  applied  it  to  the 
amorphous  ether-soluble  alkaloid  of  bebeeru 
bark  (Nedandra  Bodiei,  Hook.),  to  which  the 
formula  C,»H,«OtN  (C  =  6;  0  =  8)  was 
attributed.  This  base  was  accompanied  by 
another  amorphous  alkaloid,  slpeerine,  which 
was  insoluble  in  ether,  whilst  bebeeru  wood 
contained  a  third  amorphous  alkaloid,  nectan- 
drine  CmH^sO^N  (Maclagan  and  Gamgee, 
Pharm.  J.  1869-1870,  [ii.]  11,  19). 

2.  It  was  applied  later  to  the  total  alkaloids 
of  bebeeru  bark,  the  sulphate  of  which  was 
official  in  the  B.  P.  1885,  and  was  used  as  a 
febrifuge,  as  a  substitute  for  quinine. 

3.  Bebeerine  (from  bebeeru  bark)  has  been 
stated  to  be  probably  identical  with  the  alka- 
loids of  true  pareira  root  {Chondodendron 
iorfieTitosum,  Riuz.  and  Pav.),  with  buxine,  con- 
tained in  Buxus  sempervirena  (Linn.),  and  with 
the  pelosine  of  Cissampelos  Pareira  (Linn.), 
but  the  evidence  of  identification  is  incon- 
clusive. It  has  led,  however,  to  the  use  of  the 
term  bebeerine  for  alkaloids  isolated  from 
Chondodendron  tomentoaum  by  Scholtz  (Arch. 
Pharm.  1898,  236,  530;  1906,  244,  255)  and 
Faltis  rMonatsh  1912,  33,  873).  Scholtz'  bebee- 
rine Ci^BLiG^N  crystallises  from  methyl  alcohol 
in  colourless  prisms,  m.p.  214^,  [a]^— 298^  in 

alcohol,  f  jrms  c^stalline  salts,  is  phenolic,  and 
contains  one  'OMe  and  one  'NMe  group.  Faltis 
has  described  iS-bebeerine,  amorphous,  m.p. 
142M50^,   [a]jj+28*6*»   in   alcohol,    -24-r*   in 

pyridine ;    Mobebeerine,  rhombic  needles,  m.p 
290*',    optically    inactive;     and    bebeerine-B, 
C„H„0»N,  yeUowpowder, m.p.  220**,  [a]^-\-5G-T 

in  pyridine.  To  fi-  and  ssobebeerine,  Faltis 
attribute?  the  formula  C^jH^OfN,  whilst 
Scholtz  (Arch.  Pharm.  1913,  251,  136)  prefers 
the  formula  Ci»H,iO,N.  F.  L.  P. 

BECKELITE.  A  silicate  of  calcium  and 
cerium-oarths  Ca,(Ce,La,Di,Y)4(Si,Zr),0i„  con* 
taining  Ce,0,  281,  La,0,  13*6,  Di,0,  18-0. 
(Y,£r)tOa  2*8,  ZrO^  2*5  p.c,  etc.  It  occurs  as 
wax-yellow  grains  and  cubic  crystals  as  an 
accessory  constituent  in  a  dyke  rock  associated 
with  elaeolite-syenite  in  the  Mariupol  district 
on  the  Sea  of  Azov,  South  Russia.  The  cnrstals 
(J  cm.  diameter)  have  the  form  of  octahedra 
and  rhombic-dodecahedra,  and  resemble  pyro- 
chlore  in  general  appearance  and  physical 
characters,  but  they  possess  a  cubic  instead  of 
an  octahedral  cleavage.  Chemically,  however, 
they  are  quite  distinct  from  pyrochlore,  ooo- 
taining  no  columbium,  titanium,  or  fluorine. 
Sp.gr.  4*15 :  hardness  5.  L.  J.  S. 


BEET-ROOT. 


6(i3 


BEECHNUT  OIL.  This  oil  ia  derived  from 
the  seed-kerneli  of  the  beech  tree  (FagtM 
mhxUiea,  L.),  which  contain  from  30  to  42  p.c, 
the  yield  from  the  whole  nuts  being  from  10  to 
12  p.c.  The  oil  derived  from  the  nuts  of  the 
Japanese  beech  (var.  Sieboldi,  Maxim.)  is^ised 
for  food  and  as  a  lubricant,  for  which  latter 
purpose  it  is  not  well  suited,  as  it  is  a  *semi- 
drying  '  oil.  The  cold-drawn  oil  is  pale  yellow, 
and  has  a  pleasant  odour  and  taste.  It  has 
sp.ffr.  0-9205  at  15*";  iodine  value  111-120; 
and  mj>.  of  fatty  acids  17^-17*5^  (Higuchi, 
BulL  Forest  Exp.  ^  Stat.  Tokyo,  1915).  In 
Europe  beechnut  oil  is  sometimes  used  to 
adulterate  almond  oiL 

C.  A.  M. 

BEECH  TAR.  According  to  Fisher,  100 
parts  of  beech  wood  yield  on  dir  distillation  45 
parts  of  acetic  acid,  23  parts  of  charcoal,  4  of 
oil,  and  28  of  gas,  consisting  of  20  parts  carbon 
dioxide,  7  of  carbon  monoxide,  0*5  of  marsh 
gas,  0*05  of  hydrogen,  and  0*45  of  water  (DingL 
poly.  J.  238,  55). 

The  tar  contains  phenol,  cresol,  phlorol, 
guaiacol,  and  creosol,  the  dimethyl  ether  of 
propyl  pyrogallol,  the  dimethvl  ether  of  pyro* 
galloi,  which  on  oxidation  yield  coDrulignone  or 
cediret,  pittacal,  and  picamar. 

According  to  Gratzel  (J.  Pharm.  [5]  6,  520), 
ferric  chlori<&  colours  beech  tar  creosote  a  blue 
passing  to  brown. 

(For  a  history  of  the  investigations  made 
upon  wood  tars,  v,  Schorlemmer,  J.  Soc.  Chem. 
Ind.  4,  162,  where  also  will  be  found  a  biblio- 
ffraphy  of  the  subject ;  v,  also  CREOSOTBy  and 
Wood,  DxsTRUcnvB  distillation  OF.) 

BEESWAX  V.  Waxes. 

BEET-ROOT.  The  root  of  Beta  vulgaris 
(Linn.).  Many  varieties  are  known,  differing  in 
colour,  shape,  and  size.  Mangel-wurzel,  or 
mancold,  as  it  is  often  called,  is  a  variety  (of 
which  there  are  many  sub-varieties),  largely 
grown  as  winter  food  for  cattle ;  garden  beet-root, 
employed  as  salad  or  vegetable,  is  often  under- 
stood when  the  term  *  beet-root '  is  used.  The 
most  important  variety,  however,  is  the  sugar 
beet,  of  which  many  sub-varieties  are  known. 
These  have  been  obtained  by  careful  selection 
with  a  vie^  to  obtaining  the  highest  proportion 
of  cane  sugar. 

The  presence  of  sugar  in  the  juice  of  beet- root 
was  observed  in  1747  by  Marggraf,  who  suggested 
its  extraction  on  a  commercial  scale.  The 
early  attempts,  however,  proved  failures,  aa 
the  process  could  not  compete  with  the  cane- 
sugar  industry.  This  is  not  surprising  when  it  is 
remembered  that  the  beets  tnen  grown  only 
yielded  about  2  p.a  of  sugar. 

Careful  selection  of  seed,  and  improved 
cultivation  and  methods  of  extraction,  aided 
by  a  system  of  bounties  by  continental  Govern- 
ments, have  resulted  in  beet  sugar  almost 
entirely  replacing  cane  sugar  in  the  principal 
markets  of  Europe  (v.  Suoab). 

Beet-root  contains  water,  nitrogenous  mat- 
ten  (including  true  albuminoids  and  the  bases 
glutamine,  betaine,  and  choline),  pectins,  sugars 
(of  which  cane  sugar  and  raffinose  are  the  chief), 
oolonring  matter  of  an  unstable  character 
(Ftomanek,  J.  pr.  Chem.  1900,  iL  62,  310), 
and  ash.  It  will  be  well  to  consider,  in  turn,  the 
oomposition  of  average  specimens  of  the  three 


principal  varieties  of  beet-root  mantioued 
above. 

(a)  Manod-wuTXtiU  or  Mangolds,  called  some, 
times  field  beets.  Many  varieties,  difforing  in 
colour,  size,  and  shape,  are  in  cultivation.  Ihey 
may  be  classified  into  long,  tankard,  and  globe 
forms. 

Mangolds  grow  best  in  deep,  somewhat 
clayey  soils,  and  in  warm,  fairly  dry  climates. 
They  demand  abundant  supplies  of  plant  food, 
and,  under  favourable  oonciitions,  yield  very 
heavy  crops,  from  20  to  30  tons  per  acre  being 
usually  obtained.  They  are  better  as  food  for 
csttle  and  sheep  after  they  have  boon  stored 
for  some  weeks. 

As  in  almost  all  root  crops,  large  mangolds 
are  distinctly'  more  watery  than  small  ones. 

The  following  is  the  average  composition 
of  mangolds,  according  to  (1)  Warington,  (2) 
Kellner : — 


JL 

2 

Lsrue 

Small 
87-0 

Large 

Medium 

Small 

Water    .     . 

89-0 

89-5 

88  0 

86-5 

Nitrogenous 

substances 

1-2 

1-0 

1-3 

1-2 

M 

Either  extract 

01 

0  1 

01 

0  1 

0  1 

Soluble   car- 

• 

bohydrates 

7-7 

10-2 

6-7 

8-7 

10  0 

Oude  fibre  . 

1-0 

0-8 

10 

0-9 

0-8 

Ash    • 

10 
100  0 

0  0 

1-4 

1-1 
100-0 

0  9 

• 

100-0 

100-0 

100  0 

The  nitrogenous  substances  comprise  real 
albuminoids,  in  proportion  varying  from ^33  to 
60  p.c.  of  the  whole  (being  lowest  in  the  Inrgo 
and  highest  in  the  small  roots),  and  ami<lcfi. 
Quite  considerable  (quantities  of  nitrates  arc 
often  present  in  the  juice. 

The  soluble  *  carbohydrates  *  consist  chiefly 

of  sugars,   pectins,  cellulose,  and    pentosans ; 

starch  is  not  present.    The  ash  of  mangolds, 

according  to  VVolfF,  contains : 

KtO     MaiO    MgO  CaO    P«0|     80i      01     SlOi 

531      14-i    61    4-6     9-0     3-3      66    3*3 • 

The  unusually  large  proportion  of  chlorine  is  a 
noticeable  feature,  fieets,  being  descen(lants  of 
a  maritime  plant,  are  found  to  oe  benefited  bv 
applications  of  common  salt  to  the  soil  in 
wiuch  they  are  grown.  Oxalic  acid,  to  the 
extent  of  about  0*1  p.o.,  ia  present  in  beet- 
root. 

(6)  Oarden  htd-root.  These  are  almost  al- 
ways rod- fleshed.  In  composition  they  resemble 
the  mangel-wurzel. 

The  average  of  17  American  analyses  shows : 

Water,     87  6    p.c. ;      nitrogenous    substances, 

i  1*0  p.c;  fat,0-lp.c. ;  soluble  carbohydrates  and 

fibre,  9*6  p.c. ;  ash,  1  'I  p.c. 
I  (c)  Swjar  6e(>l4.  Of  those,  many  varieties 
have  been  obtained  by  careful  selection.  They 
are  usuallv  white-  or  ycUow-flcshed,  conical  in 
shape,  and  grow  with  the  root  entirely  under- 
ground. The  sugar  content  now  ranges  from 
10  or  11  to  16,  18,  or  even  20  p.c. 

Roots  not  exceeding  U  to  2  lbs.  in  wei^t 
are  preferred.  A  deep  medium  loam  cont>ainmg 
a  fair  proportion  of  lune  is  the  soil  best  suited 
for  their  growth.     Nitrogenous  manuring  must 


664 


BEET-ROOT. 


be  only  sparingly  done,  or  the  roots  become 
watery  and  deficient  in  lugar. 

It  is  difficult  to  give  the  typical  composition 
of  sugar  beets,  since  their  sugar  content  yaries 
so  greatly  with  variety  of  plant,  season,  size 
of  root,  cultivation,  and  manuring.  Small  roots 
are  almost  invariably  richer  tluin  larse  ones, 
other  things  being  equal ;  a  dry  period  during 
the  ripening  and  maturing  of  the  root«  is  also 
favourable  to  sugar  formation ;  well-tilled  soil, 
regularity  of  shape  of  root,  and  suitable  manur- 
ing, are  all  important  factors  in  determining  the 
yield  of  sugar. 

There  is  evidence  that  the  careful  selection  of 
beets  for  sugar  production  has  altered  the 
plant  considerably,  po  f ar  as  content  of  ash  is 
concerned  (Schneidowind,  Bied.  Zentr.  1900, 
29,  81).  The  proportion  of  ash  is  much  lower 
than  formerly,  the  quantity  of  potash  is  only 
about  hall  of  what  it  was,  while  the  soda  has 
doubled ;  magnesia  has  remained  unchanged* 
while  phosphoric  acid  is  less. 

According  to  Kellner,  the  average  composi- 
tion of  sugar  beets  is :  Water,  75  p.c. ;  crude 
protein,  1*3  p.c. ;  fat,  0*1  p.c;  soluble  carbohy- 
drates, 21-4  p.c. ;  fibre,  1-6  p.c. ;  ash,  0'7  p.c. 
In  addition  to  the  sugar  content,  the  purity 
coefficient  (the  ratio  of  cane  sugar  to  total  sugar) 
is  of  importance  {see  Suqab). 

The  leaves  of  mangolds  and  sugar  beets 
contain  much  oxalic  acid,  up  to  8  p.c.  of  the 
dry  matter  (Stoklasa,  Bied.  Zentr.  1901,  30, 
393),  and  their  ash  is  rich  in  lime,  magnesia,  and 
soda.  They  contain  about  84  p.c.  water, 
2-3  p.c.  nitrogenous  matter,  0*4  p.o.  ether 
extract,  7*4  p.c.  soluble  carbohydrates,  1*6  p.c. 
fibre,  and  4*8  p.c.  ash. 

They  are  sometimes  used  as  cattle  food, 
either  in  the  fresh  or  dried  condition,  or  some- 
times as  silage.  In  order  to  prevent  ill  effects 
from  the  oxaUo  acid  present,  it  is  recommended 
to  sprinkle  powdered  calcium  carbonate  on  the 
leaves  before  giving  them  to  animals.  About 
1  lb.  calcium  carbonate  to  1000  lbs.  of  leaves  is 
sufficient  (KeUner).  The  leaves  are  sometimes 
dried  by  artificial  heat,  and  then  furnish  a 
valuable  food,  equal  to  meadow  hay.       H.  I. 

BEET-ROOT  OUM  v.  Gums. 

BEHENIC  ACID  Cs.H.^O,  is  said  to  be 
present  as  a  glycer.'de  in  ben  oil  {q.iK).  The 
tatty  acid  nrepared  from  the  oil  melted, at  80^- 
82**  and  solidified  at  76**  79**  (J.  pr.  Chem.  1894, 
61).  The  acid  prepared  synthetically  from 
erucic  acid  has  m.p.  83^-84°,  and  solidifies  at 
77^9** ;  b.p.  (60  mm.)  306**  (Talanzeff,  J.  pr. 
Chem.  1895,  50,  71).  It  forms  acicular  crystals, 
soluble  in  alcohol  (0*102  p.c.  at  17**)  and  ether 
(0*1922  p.c.  at  16**) ;  m.p.  of  ethyl  ester,  48**-40°. 
A  method  of  detecting  rape  oil  in  olive  oil  has 
been  based  on  the  hydrogenation  of  the  liquid 
fatty  acids,  and  separation  of  the  behenic  acid 
formed  from  the  erucic  acid  ( Biazzo  and  Vigdorcik, 
Annali  Chim.  Appl.  1916,  6, 18.")).        C.  A.  M. 

BELLADONNA.  (Fr.  Belledanie.)  The 
Atropa  belladonna  (Linn.),  or  deadly  nightshade. 
A  poisonous  plant  cf  the  SolanacecB  order. 
Employed  in  medicine  as  an  anodyne,  &c.,  and 
for  dilating  the  pupil.  The  name  appears  to 
have  been  derived  ^m  the  circumstance  of  its 
employment  in  an  Italian  cosmetic.  Its 
physiological  action  is  due  to  atropine, 

BELLITE.    An  explosive  prepared  ^  y  mi ^ring 


a  nitrate  with  a  nitro-  oompouud  such  as  dinitro- 
benzene,  trinitronaphthalene,  or  nitrotoluene, 
and  then  subjecting  the  mixture  to  a  temperature 
of  from  50»  to  100*  (Eng.  Pat.  13690,  Nov.  10, 
1885;  V.  Explosives). 

%ELL1TE.  This  name  has  also  been  nsed 
(W.  F.  Petterd,  1905)  for  an  incompletely 
determined  mineral,  described  as  a  chrome- 
arsenate  of  lead,  and  occurrins  as  bright-red  or 
yellow  velvety  tufts,  or  as  powdery  encrustations, 
at  Ma^et  in  Tasmania.  L.  J.  S. 

BELL-METAL.  An  alloy  of  copper  and  tin 
used  in  the  manufacture  of  bolls.  Contains  from 
3  to  4  parts  of  copper  to  1  part  of  tin. 

BELLMETAL  ORE  v.  Stannitb. 

BENG ALINE  v.  Azo-  colouriko  mattsbs. 

BENGAL  LIGHTS.  These  fires  may  be  made 
by  mixing  potassium  chlorate,  carbon,  antimony 
sulphide,  strontium  nitrato,  &c.,  together  in 
suitable  proportions ;  but  all  such  mixtures'  of 
potassium  chlorate  and  sulphur  are  dangerous 
from  their  tendency  to  inflame  spontaneously 
owing  to  sulphur  frequently  containing  sulphurio 
acid.  Saunders  suggests  that  120  grams  of 
potassium  bicarbonate  should  be  added  to 
each  pound  of  sulphur  to  neutralise  the  free 
acid. 

An    improvement   in    the    manufacture    of 

Bengal  lights  has  been  suggested  by  Chertier 
(Wagner's  Jahr.  24, 464),  who  obtains  a  smokeless 
and  odourless  fire  by  melting  shellac  and  adding, 
with  continuous  stirring,  the  nitrate.  The  pro- 
portions given  are :  for  nd  fires,  one  part  of  shellac 
to  five  of  strontium  nitrate;  for  green,  one  of 
shellac  to  five  of  barium  nitrate;  and  for  yellow, 
one  of  shellac  to  three  of  sodium  nitrate.  They 
bum  slowly,  and  are  well  adapted  for  theatres,  Ac. 

C.  Schmidt  has  patented  (D.  B.  P.  34020, 
1885)  the  following  process.  From  1  to  10 
grams  of  magnesium  dust  are  added  to  100 
grams  of  collodion,  and  3  grams  of  barium  or 
strontium  chloride  are  addwl.  On  evaporation 
of  the  ether,  thin  plates  are  obtained  which  bom 
with  great  brilliancy. 

Another  formula  recommended  by  a  German 
firm  is,  for  white  fires,  to  fuse  one  part  sheliao 
with  six  barium  nitrate,  grind  and  mix  with  2*5 
parts  magnesium  powder.  For  red  fires,  five 
parts  strontium  nitrate  is  used  instead  of  the 
barium  nitrate.  These  mixtures  can  be  made 
into  ribbons  or  charged  into  thin  zinc  tubes  so  as 
to  make  torches  (Bingl.  poly.  J.  256, 518).  (^ee 
also  Flash  lights  :  rYBOTSCHMT.) 

BENITOITE.  This  interesting  mineral  is 
an  acid  titano-silicate  of  barium  BaTiSiaOtf 
and  forms  beautiful  sapphire-blue,  transparent 
crystals  suitable  for  cutting  as  gems.  The 
crystals  afford  the  only  known  example  (except 
Ag.HPO.  (H.  Dufet,  1886))  of  the  ditrigonal- 
bipyramidal  class.  Sp.gr.  3 •64-3*67 ;  H.  61 . 
The  dichroism  is  intense,  the  ordinary  ray  being 
colourless,  and  the  extraordinary  ray  greenish- 
blue  to  indigo-blue.  The  mineral  was  first  found 
(and  described  by  G.  D.  Louderback)  in  1907, 
near  the  source  of  the  San  Benito  river  in  San 
Benito  Co.,  California,  the  crystals  occuning 
embedded  in  natrolite  veins  traversing  achistooo 
rocks.  L^  *! ■  (^ 

BENJAMIN,  GUM,  v.  Balsams, 

BEN  OIL,  Behen  Oil,  is  obtained  from  the 
seeds  of  the  Ben  nut,  from  Moringa  ptrrtfyo- 
spcrma  {oUiJera)  and  Moringa  apiera  (Gart.). 


BENZALDEHYDE. 


6A6 


The  Moringa  trees  are  indigenous  to  India, 
Arabia,  and  Syria,  and  were  introduced  to 
Jamaica  from  the  East  Indies  in  ]784.  Moringa 
pUrygosperma  has  also  been  found  in  Northern 
Nigeria  and  Dahomey.  Ben  oil  has  a  slightly 
yeUowish  colour,  is  ooourless,  and  has  a  sweetish 
taste.  The  oil  consists  of  the  glycerides  of 
oleic,  palmitic,  and  stearic  acids;  it  also  con- 
tains a  solid  acid  of  high  melting-point,  which, 
according  to  Volcker  (Annalen,  64,  342),  is 
identical  with  behonic  acid  (m.p.  76**) ;  though 
possibly  this  acid  may  be  arachidic  acid.  In 
the  East,  ben  oil  is  used  for  cosmetic  purposes, 
it  is  also  employed  in  the  *  maceration  '  process 
for  extracting  perfumes  from  flowers.  In  the 
West  Indies  the  oil  is  used  for  edible  purposes. 
Jamaica  oil,  from  which  any  solid  deposit  has 
been  separated  by  flltration,  is  used  for  lubricat- 
ing watches  and  other  delicate  machinery,  for 
which  purpose  it  is  particularly  suitable  owing 
to  its  not  readily  oxidising  when  exposed  to  the 
air.  This  property  is  in  accordance  with  the 
low  iodine  veJue  of  the  oil.  A  genuine  sample 
from  Jamaica,  examined  by  Lewkowitsch 
(Analyst,  1903,  28,  343)  gave  the  following 
results:  sp.gr.  at  16^  0*9127;  iodine  value, 
72*2  ;  iodine  value  of  liquid  fatty  acids,  97 '53  ; 
and  butyro-refractometer  reading,  60  "0^  The 
low  iodine  value  of  the  liquid  fatty  acids  indicates 
that  fatty  acids  more  unsaturated  than  oleic  acid 
were  only  present  in  small  proportion.  Com- 
mercial samples  of  ben  oil  frequently  have  much 
higher  iodine  values  {e.g.  110),  but  the  genuine 
character  of  these  is  open  to  question.      J.  L. 

BENZACETIN  v.  8yvthbtig  deuos. 

BENZAL  CHLORIDE.  Benzylidene  chloride, 
Benzidene  chloride  {v.  Tolitxnb,  Chlobh^s  db- 
BiVATivxs  or). 

BENZALDEHYDE  C^«0  or  C.Hs-CHO.  Ben- 
toic  aldehffde.  Benzoyl  hydride.  Ethereal,  or 
volatile,  or  eMeniial  oil  of  bitter  almonds.  Essence 
of  hitter  almonds.  {Aldehyde  henzcHque,  Fr. ; 
BiUermanddOl,  Ger.)  Mortrte  showed,  in  1803, 
that,  in  addition  to  the  fatty  oU,  a  volatile 
oil  could  be  obtained  from  bitter  almonds ;  but 
pure  benzaldehyde  was  first  isolated,  its  compo- 
sition determined,  and  its  reactions  studied,  oy 
Liebig  and  Wohler  in  1837  (Annalen,  22,  1). 
Benzaldehyde  is  not  contained,  as  such,  in  bitter 
almonds:  it  is  produced  by  the  action  of  a 
soluble  ferment,  emvlsin  (also  termed  svnaptase), 

rient  in  the  almond,  on  amugdalin  CioHsyNOii. 
this  fermentation,  which  occurs  when  the 
bruised  almonds  are  mixed  with  cold  water,  the 
amygdalin  is  hvdrolysed,  yielding  benzaldehyde, 
together  with  hydrocyanic  acid  and  glucose : 

C,JH,^0u+2H,0  =  C,H,0+HCN+2C,Hi,0. 

If  boiling  water  is  used,  the  ferment  is  destroyed 
and  the  reaction  does  not  take  place.  Peach 
kemeJs  and  kernels  of  other  stone  fruits  contain- 
ing amygdalin  also  yield  benzaldehyde.  It 
occurs,  ready  formed,  in  the  leaves  of  the  cherry 
laurel  {Prunus  laurocerasus),  of  the  bird  cherry 
{Prunus  padus),  and  of  the  peach  (Amygdalus 
persica). 

Preparation, — 1.  From  bitter  almonds.  The 
bitter  almonds  (or  more  rarely,  peach  kernels) 
are  ground  and  then  cold-pressed,  to  extract  the 
fatty  oiL  The  press  cake  ia  made  into  a  thin 
cream  with  cold  water,  introduced  into  a  still, 
allowed  to  stand  for  24  hours,  and  then  distilled 


either  by  bio  wins  in  superheated  steam,  or, 
less  advantageously,  over  a  fire,  in  which  caee 
mechanical  stirring  must  be  employed  to  prevent 
the  charring  of  the  vegetable  matter.  The 
distillation  is  continued  as  long  as  the  distillate 
appears  milky.  Most  of  the  crude  benzaldehyde 
separates  as  an  oily  layer  under  the  aqueous 
distillate ;  some,  however,  remains  in  solution 
and  may  be  recovered  by  distilling  the  aqueous 
liquid,  when  the  benzaldehyde  passes  over  with 
the  earlier  portions. 

Michael  Pettenkofer  (Annalen,  122,  77) 
modifies  the  foregoing  process  as  follows : — 
12  parts  of  the  coarsely  powdered  press  cake  are 
added  to  100-120  parts  of  boiling  water,  stirring 
during  the  process,  and  the  mixture  is  kept 
boiling  for  about  half  an  hour.  In  this  way  ell 
the  amycdalin  is  obtained  in  solution.  The 
liquid  is  tnen  allowed  to  cool ;  1  part  of  ground 
bitt«r  almonds,  suspended  in  6-7  parts  of  cold 
water,  is  added,  and  after  standing  for  1 2  hours 
the  whole  is  slowly  distilled.  According  to 
Pettenkofer,  the  maximum  yield  of  bcnzaldenyde 
is  thus  obtained,  no  amygdalin  remaining  unde- 
composed.  Polz,  however,  states  (J.  1864 »  654) 
that  the  yield  of  benzaldehyde  in  this  procora 
is  no  greater  than  is  obtained  by  macerating 
merely  the  above-mentioned  1  part  of  ground 
bitter  almonds  with  cold  water  and  then 
distilling. 

The  oil  prepared  by  either  of  these  methods 
contains  hydrocyanic  acid,  from  which  it  may 
be  freed  by  fractional  distillation,  the  hydro- 
cvanio  acid  coming  over  with  the  first  part  of 
tne  distillate.  The  hvdrocyanio  acid  may  also 
be  removed  without  distillation  by  shaking  the 
oil  with  a  mixture  of  milk  of  lime  and  ferrous 
sulphate  (Liebig  and  Wohler).  The  purest  ben- 
zaldehyde is  obtained  by  shaking  the  crude 
product  with  3-4  time^  its  volume  of  a  concen- 
trated solution  of  sodium  bisulphite,  washing 
,  the  crystals  of  the  double  compound 

I  (C7H,0,NaHS0,),H,0 

with  alcohol,  recrystallising  them  from  water, 
'  and  distilling  them  with  a  solution  of  sodium 
carbonate  (Bertagnini,  Annalen.  85,  183  : 
MUUer  and  Limprioht,  ibid.  Ill,  1.36). 
I  2.  From  toluene. — ^At  the  present  dav  benz- 
aldehyde is  generally  prepared  artificially  from 
chlorinated  derivatives  of  toluene.  The  follow- 
ing are  the  chief  processes  that  have  been  pro- 
posed : — 

Lauth  and  Grimaux  (Bull  Soc.  chim.  [2]  7, 
105)  boil  I  part  of  benzyl  chloride  GcHg'CHaCl, 
li  parts  of  lead  nitrate  (or  copper  nitrate),  and 
10  parts  of  water  with  a  reflux  condenser  for 
several  hours,  passing  a  current  of  carbon 
dioxide  through  the  apparatus  to  prevent 
oxidation.  Half  the  liquid  is  then  distiUed  off, 
and  the  oil,  which  separates  in  the  distillate,  is 
rectified.  The  product,  which  consists  mainly 
of  benzaldehyde,  may  be  further  purified  by 
converting  it  into  the  bisulphite  compound. 

The  Dow  Chemical  Co.  (U.S.  Pat.  1272522) 
heat  benzyl  bromide  with  an  aqueous  solution 
of  calcium  nitrate  or  sodium  nitrate.  The 
reaction  takes  place  between  equimolecular 
proportions  of  benzyl  bromide  and  sodium 
nitrate,  and  the  benzaldehyde  ia  practically  a 
pure  product. 

IL  Schmidt  (D.  R.  P.  ^»W>»  \  3.  %oc.  Chem. 


666 


BEKZAI.DEHYDE. 


Ind.  1883,  274)  chlorinates  boiling  toluene  until 
it  attains  a  8p.gr.  of  l'I75,  when  it  consists 
essentially  of  a  mixture  of  2  mols.  of  benzyl 
chloride  with  1  moL  of  benzal  chloride.  This 
product  is  boiled  with  six  times  its  volume  of 
water  and  a  quantity  of  powdered  black  oxide 
of  manganese  containing  two  atoms  of  available 
oxygen  to  the  above  molecular  proportion. 
The  reaction  is  supposed  to  take  place  according 
to  the  equation 

2C.H,CH,a+C,H,CHCa,4-2MnO, 

=3C.H,.CHO+2MnC3,  r  H,0 

The  product  is  steam-distilled,  and  the  aldehyde 
purified  in  the  usual  wsy.  A  mixture  of  benzyl 
bromide  and  benzal  bromide  may  be  substituted 
for  the  chlorine  compounds. 

Another  method  consists  in  heating  benzal 
chloride  with  milk  of  lime  under  pressure. 

CA*CHClt-fCa(OH),=C«Hf'CHO+CaCI,+HsO 

According  to  Espenschied  (D.  R.  P.  47187),  tlie 
reaction  takes  plaoe  under  ordinary  pressures  if 
insoluble  substances  such  as  chalk  or  barium 
sulphate  are  added'  along  with  the  milk  of  lime, 
so  as  to  produce  an  emulsion  of  the  benzal 
chloride. 

E.  Jacobsen  (D.  R.  P.  11494  and  13127; 
Ber.  13, 2013,  and  14, 1425)  heats  benzal  chloride 
with  an  organic  acid  (or  an  ethereal  salt  of  an 
organic  acid)  and  a  metallic  chloride,  oxide,  or 
sulphide.  Thus  benzal  chloride,  when  heated 
on  the  water-bath  with  acetic  acid  and  a  little 
zinc  chloride,  yields  benzaldehyde,  acetyl 
chloride,  and  hy(uochloric  acid 
CcH,-CHCIls+0H,'COaH=0eH^'CHO-fCH,'0OCl-l-HQ 

The  acetyl  chloride,  owing  to  its  much  lower 
boilinff-point,  may  be  readily  removed  from  the 
benzaldehyde  bv  distillation. 

Benzaldehyae  can  be  prepared  by  oxidising 
benzyl  aniline  to  benzyudene  aniline,  which, 
on  addition  of  acids,  splits  into  benzaldehyde 
and  aniline.  For  this  purpose  100  kilos,  of 
benzyl  aniline,  and  from  600-1000  litres  of 
water  are  placed  in  a  laige  retort  fitted  with  an 
agitator;  during  agitation  and  boiling  the 
following  mixture  is  gradually  run  in  during  a 
few  hours :  potassium  or  sodium  bichromate, 
50  kilos ;  water,  200  litres,  acidulated  with 
hydrochloric  acid  (20®B.),  165  kilos,  or  its 
equivalent  of  sulphuric  acid  ;  distillation  ensues, 
water  and  benzaldehyde  coming  over.  The 
nitrobenzaldehydes  may  be  obtaimed  by  sub- 
stituting the  corresponding  nitrobenzylaniline. 
Another  method  consists  in  oxidising  the  salt 
of  the  benzylaniline  sulnhonio  acid  to  the 
benzylidene  compound,  ana  then  treating  it  with 
the  salt  of  an  aromatic  base,  followed  by  hydro- 
chloric acid.  The  aldehyde  is  formed,  and  the 
aromatic  base  can  be  recovered  and  used  for 
another  operation  (Farb.  vorm.  Meister,  Lucius, 
and  Bruning,  Eng.  Pat.  10689  and  30118; 
D.  R.  P.  110173;  J.  Soo.  Ghem.  Ind.  1897, 
558,  and  1899,  36).  It  has  been  prepared  by 
passing  a  current  of  air  charged'  with  the  vapour 
of  toluene  through  a  chamber  containing  a 
catalyser  such  as  oxide  of  iron,  and  heated 
between  150^  and  300^  By  substituting  porous 
carbon  for  oxide  of  iron  and  using  a  nigher 
temperature,  benzoic  acid  may  be  obtaintNl 
(Chavy,  Delage,  and  Woog,  Fr.  Pat.  379716; 
J.  Soo.  Ghem.  Ind.  1907,  1254;  IpatiefF,  Ber. 
1908,  993). 


It  has  also  been  prepared  by  the  oxidation  of 
benzyl  aniline,  or  benzyl  tolnidine  with  chromic 
acid  mixture  or  with  potassium  permanganate 
solution  in  acetone  (D.  R.  PP.  91503,  92084 ; 
FrdL  iv.  129,  131). 

It  has  also  been  prepared  from  phenyl 
magnesium  bromide  and  orthoformic  ester 
(Farb.  vorm.  Fried.  Bayer  A  Co.  D.  R.  P. 
157573  ;  GhenL  Zentr.  1905,  L  309).  By  using 
15  grams  of  magnesium,  ICiO  grams  of  bromo- 
benzene,  and  60  grams  of  orthoformic  ester,  a 
90  p.c.  yield  can  be  obtained  (Bodronx,  Compi. 
rend.  1904,  L  92).  Gatterman's  adaptation  of 
the  Friedel  and  Grafts  reaction  (Annalen,  1906, 
347,  347)  has  also  been  employed  for  the  pre- 
paration of  benzaldehyde.  In  this  process 
benzene  is  condensed  with  hydrogen  chloride 
and  carbon  monoxide  in  the  presence  of  alumi- 
nium chloride  and  cuprous  chloride,  the  mixture 
of  gases  acting  potentially  as  formyl  chloride; 
condensation  following  the  usual  course  (D.  R.  P. 
126421) 

C,H,+G1GH0=G,H,-CH0+Ha 

Schuke(D.  R.  PP.  82927,  85493)  heats  b^uo- 
trichloride  at  25^-30®  with  some  ferric  benzoate 
or  finely  divided  iron,  water  is  then  added,  and 
the  mixture  warmed  to  90*^-95®,  when  hydro- 
chloric acid  distils  over.  The  residue  is  decom- 
posed by  milk  of  lime  and  distilled  in  a  cnrrNit 
of  steam  to  obtain  the  aldehyde. 

Owing  to  the  fact  that  the  product  obtained 
from  the  chlorinated  derivatives  of  toluene 
frequently  contains  chloro-  compounds,  methods 
have  been  devised  for  the  direct  oxidation  of 
toluene  to  the  aldehyde.  Rasohiff  (Ghem.  Zeit. 
1900,  24,  446)  uses  manganese  dioxide,  in  the 
presence  of  65  p.c.  sulphuric  acid  at  40^.  300 
Icilos  of  toluene  are  mixed  with  700  kilos  sul- 
phuric acid,  and  90  kilos  finriy  powdered  precipi- 
tated manganese  dioxide  are  added,  the  whole 
being  violently  shaken  during  the  addition, 
and  the  temperature  kept  at  40^.  After  com- 
pletion of  the  action  the  benzaldehyde  and  un- 
altered toluene  are  driven  over  and  the  aldehyde 
separated  in  the  usual  manner  .(</.  D.  R.  PP. 
101221,  107722).  The  Badisohe  Anilin  u. 
Soda-Fabrik  use  nickel  and  cobalt  oxidee,  as 
oxidants  (D.  R.  P.  127388),  whilst  the  firm 
of  Meister,  Lucius,  und  Bruning  (D.  R.  P. 
158609)  have  suggested  the  use  of  cerium  com- 
pounds. 

By  passing  a  stream  of  carbon  monoxide 
and  hydrochloric  acid  gas  (2:1)  through  a 
cooled  mixture  consisting  of  equal  weights  of 
aluminium  bromide  and  benzene,  and  ^  their 
weight  of  copper  chloride,  a  solid  mass  is  ob- 
tained :  this  is  decomposed  by  ioe  water, 
extracted  with  ether,  and  fractionated.  The 
yield  is  85-90  p.c.  (Eleformatsky,  D.  R.  P. 
126421 ;  Ghem.  Zentr.  1901, 1  1226 ;  iL  1372). 

Benzaldehyde  has  also  been  prepared  l^  the 
electrolytic  n^uction  of  benzoic  acid  or  its  salts. 
An  electrode  of  finely  divided  graphite  and 
benzoic  acid  is  employed  as  the  cathode  of  the 
cell,  the  anode  being  of  lead  or  platinum.  The 
solution  in  the  cell  is  20  p.c.  sulphuric  acid, 
saturated  with  benzoic  acid,  the  current  used 
is  1*5  amp.  per  sq.  dcm.,  and  12-15  volte 
(Mithack,  D.  R.  P.  123554 ;  Ghem.  Soo.  Abatr. 
1902,  i.  291).  Mettler  (Ber.  1908,  4148)  uses  a 
sodium-amalgam  electrode ;  and  Moeet  (D.  R.  P. 


BENZALDEHYDE. 


667 


138442 ;  Chem.  Zentr.  1903,  i.  370)  electrolyses 
a  solution  of  sodium  phenylaoetate. 

A  method  has  been  described  for  purifjrinff 
benzaldehyde  by  dissolving  it  in  sulphurous  acia 
and  precipitating  the  bisulphite  compound  by 
adding  potassium  chloride  (Chem.  Fab.  Groi- 
sheim-Elektron,  D.  R.  P.  154499 ;  CQiem.  Zentr. 
1904,  ii.  965). 

Other  modes  of  fomuUion, — Benzaldehyde  is 
also  formed  in  the  following  reactions,  which, 
however,  are  not  of  praotic^  importance.  Bv 
distilling  a  mixture  of  calcium  benzoate  and  cal- 
cium formate  (Piria,  Annalen,  100,  105) ;  by  the 
oxidation  of  benzyl  alcohol  (Cannizzaro,  Ann. 
Chim.  Phys.  [3]  40,  234);  of  cinnamic  acid 
(Dumas  and  Peligot,  Annsilen,  14,  60  ;  Harries, 
Ber.  1903,  1296) ;  or  of  stilbene  (Harries,  2.c) ; 
by  the  reduction  of  benzoic  acid,  either  with 
sodium  amalgam  in  acid  solution  (Kolbe, 
Annalen,  118,  122),  or  by  passing  its  vapour 
over  heated  zinc-dust  (Biaeyer,  Annalon,  140, 
296) ;  by  treating  toluene  i»ith  chromyl  chloride 

and  then  with  water  (Etard,  Ann.  C!him.  Phys. 
[5]  22,  226) ;  by  treating  1  molecule  of  benzal 
chloride  with  slightly  more  than  2  molecules  of 
acetio  acid  (B^al,  Gompt.  rond.  148,  179) ; 
by  acting  on  benzophenoneoxime  with  phos- 
phorus pentasulphide,  and  decomposing  the 
thiobenzanilide  thus  formed  with  boiling  alkali 
and  zinc-dust  (Cuisa,  Chem.  Zentr.  1907,  i.  28). 

Properties, — Benzaldehyde  is  a  colourless, 
strongly  refractive  liquid  with  a  pleasant  aro- 
matic odour,  boiling  at  179^-180  ,  and  solidi- 
fying at  --13*6®  (Piotet^  Compt.  rend.  119, 
955 ;  Altschul  and  Schneider,  Zeitsch.  physical,  i 
Chem.  1896,24);  sp.gr.  1-0504  1674'' (Mendel^ff, 
J.  I860,  7).  It  is  soluble  in  300  parts  of  water, 
and  miscible  in  all  proportions  with  alcohol 
and  ether.  It  is  non-poisonous,  the  poisonous 
properties  of  ordinary  oil  of  bitter  almonds 
being  due  to  the  presence  of  hydrocyanic  acid. 
Its  magnetic  rotatory  power  has  been  studied 
by  Perkin  (J.  Chem.  Soo.  1896,  1064). 

Reactions. — Benzaldehyde  readily  undergoes 
oxidation  ;  thus  it  absorbs  oxygen  m>m  the  air, 
forming  .benzoic  acid.  The  presence  of  hydro- 
cyanic acid  protects  it  from  oxidation ;  accord- 
ing to  Dusart  (BuU.  Soo.  chim.  8,  469),  it  is 
theroforo  usual  to  add  hydrocyanic  acid  to 
artificial  benzaldehyde.  Taken  internally, 
benzaldehyde  is  oxidised  in  the  organism,  re- 
appearing in  the  urine  as  hippuric  acid  and 
benzamide.  Aqueous  catuiic  potash  converts  it 
into  benzoic  acid  and  benzyl  alcohol 

2C,HgCHO+KOH=C,H,CO,K4-C,H5CH,OH 

When  warmed  with  alcoholic  potassium  cyanide 
it  is  converted  into  benzoin 

C.H,CHOHCOC,H» 

It  forms  crystalline  compoimds  with  the  bisul- 
^iUs  of  the  alkali  melals  ;   thus  : 

(0,H,0,NaHSO,),H,0 

Under  the  influence  of  dehydrating  agents,  it 
readily  undergoes  condensation  with  various 
other  substances ;  thus  when  heated  with  acetic 
anhydride  and  dry  sodium  acetate  it  yields  cinna- 
mic acid. 

C,H,-CHO-f  CHs'COtH=CtH,*CH :  CH-CO^H+H^O 

(Perkin,  J.  Chem.  Soc.  31, 389) ;  cinnamic  acid  is 
also  obtained  from  ethyl  acetate  and  benzaldehyde 
(daisen,  Ber.  1890,  976 ;   Farb.  vorm.  Meister, 


Lucius  and  Bruning,  D.  R.  P.  53671;  Ber. 
1891,  Ref.  180).  It  combines  with  hydrazine 
to  form  benzalazine  Ci^H^iNs,  which,  on  dis- 
tillation, yields  stilbene  (diphenyl-ethylene) 
C,H.-CH  :  CH-CeH..  With  dimsthylanUine  in 
presence  of  zinc  chloride  it  forms  the  compound 
CeH,CH(CtH4NMe,),.  the  leuco-  base  of 
benzaldehyde  green  which,  by  oxidation,  is 
converted  into  that  colouring  matter  (O. 
Fischer,  Ber.  11,  950). 

When  hydrogenatcd  in  presence  of  nickel 
between  210°  and  235"",  benzaldehyde  yields  a 
mixture  of  benzene  and  toluene,  together  with 
their  hexahydrides.  Under  other  conditions  it 
may  be  reduced  by  the  catalytic  action  of 
metals  and  hydrogen  to  benzyl  cdcohoL 

With  pyro^allol  benzaldehyde  forms  dye- 
stufib  of  the  triphenylmethane  series  (Hofmann, 
Ber.  1893,  1 139),  and  with  chloracetopyrogallol 
a  golden-yellow  dyestuff  (Kusselkaul  and 
Kostanecki,  Ber.  1896,  1886).  By  heatins 
benzaldehyde  with  a  little  sulphur  in  a  sealed 
tube,  stilbene  and  benzoic  acid  are  formed 
(Barbaglia  and  Marquardt,  Ber.  1891,  1881). 

Derivatives. — The  most  important  derivatives 
are  the  sulphonic  acids,  which  are  the  parent 
substances  of  various  dyestuffs  (Gnehm  and 
Schule,  Annalen,  299,  347).  Benzaldehyde  o- 
sulphonic  acid  (Kafa,  Ber.  1891,  791 ;  Wallach 
and  Wflster,  Ber.  1893,  160;  Gnehm  and 
Schfile,  Annalen,  1898,  24;  D.  R.  P.  88962), 
Benzaldehyde  «-Bulphonio  acid  (Farb.  vorm. 
Sandoz,  D.  R.  P.  154528 ;  Chem.  Zentr.  1904, 
ii  1269). 

Impurities  and  aduUerations. — Benzaldehyde 
very  frequently  contains  hydrocyanic  acid, 
either  originally  present  or  suoeequently  added 
(v.  supra),  and  benzoic  acid,  formed  by  spon- 
taneous oxidation.  The  artificial  product  gene- 
rally contains  chlorinated  benzaldehydes.  Alco- 
hol, ethereal  oils,  and  nitrobenzene  are  some- 
times fraudulently  added  ;  the  latter  substance 
resembles  benzalaehyde  in  smelL 

In  order  to  test  the  purity  of  a  sample  of 
benzaldehyde,  the  8p.gr.  and  boiling-point  snould 
first  be  determined,  as  both  of  these  are  altered 
by  the  presence  of  impurities.  The  substance 
should  also  dissolve  without  residue  in  a  solution 
of  sodium  bisulphite. 

Of  the  impurities  above  mentioned,  hydro- 
cyanic acid  may  be  detected  by  distiUins  the 
oil  and  then  testing  the  first  portions  of  the 
distillate  by  the  Prussian-blue  test;  chlorine 
compounds,  by  heating  the  oil  with  metallic 
sodium,  when  Eodium  chloride  will  be  formed* 
in  which  the  chlorine  can  be  detected  b^  silver 
nitrate,  taking  care,  however,  to  distinguish 
between  silver  chloride  and  silver  cyanide,  as 
this  latter  will  be  formed  if  hydrocyanic  acid  or 
nitrobenzene  is  present ;  alcohol,  by  the  iodo- 
form test ;  and  ethereal  oils  or  nitrobenzene,  by 
dissolving  the  sample  in  sodium  bisulphite, 
when  these  admixtures  remain  behind.  Bour- 
goin  (Ber.  6,  293)  tests  for  nitrobenzene  in 
benzaldehyde  by  mixing  the  sample  with  twice 
its  volume  of  caustic  potash  :  if  nitrobenzene  is 
present,  the  mixture  turns  green,  and  on  adding 
water  the  liquid  forms  two  layers,  of  which  the 
under  layer  is  yellow  and  the  upper  green, 
this  latter  turning  red  on  standing  for  some 
hours. 

Estimation, — Xhe  teagent  employed  consists 


M8 


BENZALDEHYDB. 


of  1  C.C.  of  fmhly  redistiiled  phenvlhydiazine, 
0*5  cc.  glacial  acetic  acid  dissolved  in  100  cc. 
distilled  water.  Hie  liquid  oontaining  the 
benzaldehyde  is  heated  on  the  water-bath  for 
hiUf  an  hour,  set  aside  for  12  honrs,  uid  filtered 
through  a  Gooch  crucible,  dried  over  oono. 
sulphuric  acid,  and  weighed.  Weight  of  phenyl 
hydrazone  X  0*5481  gives  the  amount  of 
benzaldehyde  present.  Small  quantities  may 
be  satisfactorily  estimated  by  this  method 
(H^rissey,  J.  Pharm.  1906,  60;  Dennis  and 
Dunbar,  J.  8oc.  Chem.  Ind.  1090, 488).  Another 
method  consists  in  estimating  benzaldehyde 
colorimetrically  with  fuchsin  decolourised  with 
sulphurous  acid  (Woodman  and  Lyford,  J. 
Amer.  Chem.  Soo.  1908,  1607). 

To  estimate  the  presence  of  benzoic  acid, 
60  c.c.  of  the  sample  are  shaken  with  water 
and  10  c.c.  N-sodium  hydroxide,  the  excess 
alkali  being  then  back  titrated  with  N-acid, 
using  phenolphthalein  as  indicator. 

Substitution  Desivatiyes  of  Bekzaldehydb. 

o-Nitrobenzaldehyde.  It  may  be  prepared 
by  the  oxidation  of  the  dimercuiy  derivative  of 
o-toluene  (Reissert,  D.  R.  P.  186881;  Chem. 
Boc.  Abstr.  1907,  L  1046  ;  Kalle  ^  Co.,  D.  R.  P. 
199147;  Chem.  Soc.  Abstr.  1909,  L  76);  by 
the  oxidation  of  o-nitrotoluene  with  manganese 
dioxide  or  by  passing  the  vapour  of  the  hydro- 
carbon over  manganese  dioxide  heated  to  210^- 
250®  (Gilliaid,  Monnet  and  Cartier,  D.  R.  P. 
101221 ;  Chem.  Zentr.  1899,  L  960 ;  Bad.  Anil, 
u.  Sod.  fab.,  Eng.  Pat.  21947 ;  J.  Soc.  Chem 
Ind.  1900,  892) ;  by  the  oxidation  of  o-nitro- 
toluene with  nickel  oxide,  nickel  chloride,  and 
hypochlorite  (Bad.  AniL  u.  Sod.  Fab.,  D.  R.  P. 
127388;  Chem.  Zentr.  1902,  i.  150);  by  the 
oxidation  of  o-nitrobenasylaniline  {q.v.  benzalde- 
hyde) ;  by  the  oxidation  of  o-nitrobenzylalcohol 
and  its  esters  (Eug.  Fischer,  D.  R.  P.  48722 ; 
Frdl.  ii  98;  Kalle  &  Co.,  D.  R.  PP.  104360, 
106712;  Chem.  Zentr.  1899,  ii.  950;  1900,  i. 
885) ;  by  the  hydrolysis  of  o-nitrobenzaldehyde 
dlacetate,  which  is  obtained  by  the  oxidation  of 
o-nitrotoluene  with  a  mixture  of  acetic  anhydride, 
acetic  acid,  and  sulphuric  acid  (Thiefe  and 
Winter,  Annalen,  311,  356 ;  Fried.  Bayer  k  Co., 
D.  R.  P.  121788;  Chem.  Zentr.  1901,  ii  70); 
or  by  the  oxidation  of  the  sodium  salt  of  o- 
nitrophenylnitromethane  by  potassiura  per- 
manganate at  low  temperature  m  aqueous  solu- 
tion (Soo.  Chim.  des  Usines  du  Rhdne,  D.  R.  P. 
237358) 

3C,H4(NO,)CH :  NOONa4-2KMn04-hH,0 
«3C.H4(NO,)CHO+3NaNO,-f2MnO,+2KHO 

Properties. — ^Laige  yellow  needles,  m.p.  46*. 
When  treated  with  acetone  and  caustic  soda  it 
yields  indigotin  (Baeyer,  Ber.  16,  2866).  With 
methyl-  and  ethyl-aniline  or  their  sulphonic 
acids  it  condenses  to  form  leuco-bases  of  blue- 
green  triphenyl  methane  dyestuffs  (Clayton 
AniUne  Co.,  D.  R.  P.  108317;  Chem.  Zentr. 
1900,  i.  1081). 

m-Nltrobenzaldehyde.  It  may  be  prepared 
b^r  dissolving  1  volume  of  benzaldehyde  in  a 
mixture  of  6  volumes  of  fuming  nitric  acid,  and 
10  volumes  of  sulphuric  acid,  precipitating  by 
addition  of  water  and  recrystaUusing  from 
dilute  alcohol  (Widmann,  Ber.  13,  678 rSertag- 
-^^Qi,  Annalen,  79,  260). 


Properties. — Pale-jrellow  needles,  m-p.  68". 
It  condenses  with  1»e  sulphonic  acids  of  the 
tertiary  aniline  bases  to  yield  dyestn£te  (Kalle  A 

Co.,  D.  R.  P.  73147,  Frdl ;  iii.  85). 

IvNttrobeilBadeliyde.  It  is  prepared  by 
similar  methods  to  those  by  which  the  ortho- 
compound  is  obtained  (D.  R.  PP.  91503,  92084, 
93539;  Frdl.  iv.  129);  by  heating  p-nitro- 
benzylfJcohol  with  copper  oxide  or  other 
metallic  oxides  (Schmidt^  D.  R.  P.  15881; 
Frdl.  L  60). 

Properties.— Ck>\onrie»  prisms,  m.p.  106*. 
It  condenses  with  benzene  and  it«  homologues 
by  addition  of  sulphuric  acid  to  form  p-nitro- 
triphenylmethane  (Stolz,  D.  R.  P.  40340 ;  FrdL 
i.  68) ;  with  secondary  and  tertiary  amines  to 
form  alkyl-  and  aryl-  derivatives  of  p-nitro- 
diaminotriphenylmethane  (O.  Fischer,  D.  R.  PP. 
16766,  16707 ;   Frdl.  L  54) ;   and  with  the  sul- 

{>honic  acids  of  tertiary  aniline  bases  (Kalle  k 
>).,  D.  R.  P.  73147 ;  Frdl.  iU.  86).  The  sul- 
phonic  acid  of  p-nitrobenzaldehyde  is  prepared 
by  the  oxidation  of  p-nitrotoluene  o-sulpnonic 
acid,  and  from  it  blue  and  bluish-red  dyestufis 
of  the  triphenylmethane  series  are  easily  obtain- 
able (Green  and  Wahl,  Eng.  Pat.  21825;  J. 
Soo.  Chem.  Ind.  1898,  916).  2.4-Dillitrobaii- 
aldehyde  has  been  prepared  by  Sachs  (Ber.  1902, 
35,  1228)  by  condensing  2'4-dinitrotoluene  with 
p-nitrosodunethylaniline  and  decomposition  of 
the  resultant  product  by  acid 

(N0,),C,H,CH,-t-N0-C,H4N(CH,), 

«(N0,),C,H,CH=NC,H4N(CH,), 
(N0,),C,H,-CH=NC,H4N(CH,),-fH,0 

=(NO,),C.H,CHO  +H,NC,H4N(CH,), 

a 

o-Chlorbenzaldehyde  ^  yCHO.  It  is  pre- 
pared by  the  oxidation  of  o-chlortoluene  with 
manganese  dioxide  and  sulphuric  acid  (Gillard, 
Monnet  et  Cartier,  D.  R.  P.  101221 ;  Chem. 
Zentr.  1899,  i  960),  by  extraction  from  the 
products  of  the  incomplete  chlorination  of 
o-nitrotoluene  (Kalle  k  Co.,  D.  R.  PP.  110010, 
115516;  Chem.  Zentr.  1900,  ii.  460,  1168). 

Properties. — ^Jt  is  a  liquid,  freezing  at  — 4*, 
and  boiling  at  208''  (748  mm.) ;  sp.gr.  1*29  at 
8°.  By  heating  with  sulphite  it  is  converted 
into  benzaldehyde  o-sulphonic  acid  (Gei^r  k 
Co.,  D.  R.  P.  88962;  Frdl.  iv.  113).  It  is 
easily  condensed  with  aromatic  secondary  and 
tertiarv  amines  to  yield  dyestufis  of  the  tri- 
phenylmethane group  (Greigy  k  Co.,  D.  R.  P. 
94126 ;  Chem.  Zentr.  1898,  i.  296).  By  sulpho- 
nation,  1:3:  6-chlorbenzaldehyde  sulphonic  acid 
is  produced,  which  when  condensed  with 
secondary  or  tertiary  amines  and  then  oxidised 
yields  greenish-blue  or  blue  dyeetuffs  (Soo. 
Chem.  Ind.  of  Basle,  Eng.  Pat  26128 ;  J.  Soc. 
Chem.  Ind.  1897.  137;  Gnehm  and  Schiile, 
Annalen,  290,  347). 

m-Chlorbeiualdehyde.  It  is  obtained  from 
m-nitrobenzaldehyde  by  replacing  the  nitro* 
group  by  chlorine  (Erdmann  and  Schwechten, 
Annalen,  260,  259;  Eichengriin  and  Einhom, 
ibid.  262,  135).  It  crystallises  in  prisms,  m.p. 
17*,  and  boils  at  213^ 

p-Chlorbenxaldehyde.  It  is  associated  with 
the  ortho-  compound  in  most  preparations,  and 
may  be  obtained  from  the  mixture  by  sulpho- 
nating  the  ortho-  compound  by  treatment  with 


BENZENE  AND  ITS  HOMOLOGUEa 


669 


faming  sulphuric  acid  (Gresel.  f.  Chem.  Ind., 
D.  R.  P.  98229  ;  Chem.  Zentr.  1898,  ii.  743) ;  by 
niirating  the  ortho-  compound  with  nitric  and 
Rulphuric  acids,  and  steam-distilling  the  para- 
compound  (Gesel.  f.  Chem.  Ind.,  D.  R.  P. 
102745 ;  Ohem.  Zentr.  1899,  ii.  408) ;  by  frac- 
tional distillation  (Farb.  vorm.  Meister,  Lucius 
and  Bruning,  D.  R.  P.  207157 ;  J.  Chem.  Soc. 
Abst.  1909,  i.  307).  It  is  a  crystalline  solid, 
melting  at  47*5'',  and  boiling  at  21^°-214^ 

Of  the  diehlorbenzaldehydes  the  2:5-  and 
2 : 6-dichIor-  compounds  are  the  parent  sub- 
stances of  many  dyestuffs  2  :  5-diehiorbenzalde- 
hyde  (Gnehm  and  Banziger,  Ber.  1896,  875; 
Schfile,  Annalen,  299,  34)  melts  at  57*'-58'*,  and 
is  obtained  by  the  action  of  antimony  penta- 
chloride  on  benzaldehyde  in  the  presence  of 
iodine.  2  : 6-dlehlorbeiizaldehyde  (Anil.  Fabw. 
und  Ext.  Fabrik.,  D.  R.  P.  199943  ;  Chem.  Soc. 
Abstr.  1908,  i.  986).  Reduction  of  the  nitro- 
benzaldehydes  yields  the  amino-benzaldehydes, 
of  which  the  most  important  is  the  para- 
compound.  This  may  also  be  prepared  by 
heating  p-nitrotoluene  with  sulphur  and  sodium 
hydroxide  (Geigy.D.  R.  P.  86874).  Bayer  &  Co. 
(D.  R.  P.  218364)  separate  the  amino-Jpenzalde- 
hydes  by  reducing  the  crude  nitro-  compounds 
with  hot  sodium  hydrosulphite  solution,  cooling 
to  60^,  and  acidification  with  hydrochloric  acid. 
The  mixture  is  then  boiled  for  one  minute,  and, 
on  coolinc,  the  anhydro-compound  of  the  o- 
aminoaldohyde  separates,  whilst  the  m-amino- 
benzaldehyde  remcuns  in  solution,  and  can  be 
recovered,  and  hence  used  for  the  preparation 
of  the  m-hydroxybenzaldehyde.  ^-Dimethyl- 
amino  benzaldehyde  (CH,),N'CeH4*CH0  is  best 
obtained  by  Ullmann  and  Frey's  method  (Ber. 
1904,  37,  859),  in  which  jD-dimethylaminobenzyl 
alcohol  (from  dimethylanitine  and  formaldehyde) 
is  condensed  with  ^nitrosodimethylaniline,  and 
the  resulting  compound  decomposed  by  nitrous 
acid.  It  oiystaUises  in  colourless  needles, 
melts  at  73^,  and  is  used  in  the  preparation  of 
triphenylmethane  dyes. 

Hydroxybenzaldeliydes  (^.t*.)  Salicylaldebyde. 

BENZALDEHYDE  GREEN   v.   Triphentl- 

MBTHANB  OOLOUBriTO  MATTERS. 

BENZALDEHYDE  oSULPHONIC  ACID 

SO.H 
<3CH0 

The  most  technically  important  member  of  the 
group,  is  obtained  by  heating  o-chlorobenzene- 
aldehyde  with  an  aqueous  solution  of  sodium 
sulphite  under  pressure  at  170*^-180®,  and 
treating  the  product  with  sulphuric  acid.  When 
the  sulphur  dioxide  is  expelled  by  boiling,  the 
cooled  liquid  is  neutralised  with  sodium  carbo- 
nate, and  the  sodium  salt  extracted  with  alcohol. 
Or  the  sulphonic  acid  may  be  converted  into 
the  sparingly  soluble  barium  salt  (Geigy  &  Co., 
D.  R.  P.  88952). 

The  free  acid  is  a  syrup ;  the  sodium  and 
barium  salts  crystallise  in  prisms  (Gnehm  and 
Sohule,  Annalen,  1898,  299,  347). 

The  acid  may  also  be  prepared  by  oxidising 
stilbene  disulphonic  acid  with  potaissium  per- 
manganate (Levinstein,  Eng.  Pat.  21968,  1897). 

BENZAMIC  ACIDv.  Ajoko-  aoids  (aromatic). 


BENZANTHRONE, 


Prepared  by  heating  a  mixture  of  anthranol 
with  sulphuric  acid  and  glycerol  at  120^, 
treating  the  product  with  water,  washing  the 
crude  substance  with  sodium  hydroxide  solu- 
tion, pressing,  and  drying.  .May  be  prepared 
from  anthracene  by  treatment  with  sulphuric 
acid  and  glycerol  (Badische  Anilin  und  Soda 
Fabrik,  B.  R.  P.  176019) ;  and  by  condensing 
anthranol  with  acetin,  or  2-aminoanthraquinone 
with  dichlorohydrin  {idem.  D.  R.  P.  204354) ; 
or  by  heatinff  phenyl-a-naphthyl  ketone  with 
aluminium  chloride  or  ferric  chloride.  For 
other  syntheses,  v.  Schaarschmidt  and  Korten, 
Ber.  1918,  51,  1074;  Schaarschmidt  and 
Georgeacopol,  Ber.  1918,  51,  1082 ;  v.  Kbtonbs. 

Crystallised  from  alcohol  benzanthrone  forms 
pale  yellow  needles,  m.p.  170®.  Used  in  the 
manufacture  of  indanthrene  dyes  {see  Benzan- 
throne Colours,  art.  Ikdanthbbnx). 

BENZAURIN  v.  Axtbin. 

BENZENE  AND  ITS  HOMOLOGUES. 

Benzene.  {Bemol,  Benzole,  Fr. ;  Benzol, 
Ger.)  The  name  of  this  substance  was  derived 
in  its  original  form  from  that  of  gum  benzoin, 
probably  as  benzoin  oleum,  hence  benzole,  which 
latter  form  is  still  in  use  amongst  nearly  all 
distillers  and  users  of  it  both  in  this  country  and 
on  the  Continent  In  more  strictly  scientific 
literature,  however,  the  name  benzene  has  now 
become  generally  accepted,  and  the  systematic 
termination  -ene  is  employed  in  the  names  of 
its  various  homologues,  as  toluene,  xylene, 
cymene,  &o. 

Pure  benzene  is  a  limpid,  colourless,  highly 
refracting  liquid  at  ordinary  temperatures.  Its 
sp.gr.  at  0°  is  0*8991  (Kopp),  0-90023  (Adriaansz), 
and  at  15"*  0-8841  (Mendel^ff). 

Its  refraction  index  for  the  D  line  at  16*2^  is 
1  -4957  ( Adriaansz) ;  at  9°,  1  -4593  for  A,  1  -5050  for 
D.  1-5037  for  H  (Gladstone);  at  8•5^  1-60381 
for  H«  (Perkin,  Chem.  Soc.  Trans.  1900,  77, 
273). 

When  surrounded  by  ice  it  becomes  solid, 
and  if  crystallisation  is  allowed  to  take  place 
slowly,  rhombic  crystals  are  produced,  the 
axes  of  which,  a,  b,  c,  are 0891,  1,  0*799  (Groth). 
The  solid  melts  at  5-483''  (Richards  and  Shipley, 
J.  Amer.  Chem.  Soc.  1914,  36,  1825). 

It  contracts  on  solidification,  the  difference 
in  the  specific  volume  of  the  liquid  and  solid 
Vf—v^=sAv  is  between  01219  and  0*1304  at  6*35'* 
(Heydweiller,  Ann.  Phys.  Chem.  1897,  (ilL)  61, 
527). 

It  exhibits  no  absorption  lines  or  bands  in 
the  visible  portion  of  the  spectrum.  Beyond 
H,  however,  photographs  show  a  series  of 
four  bands  covering  the  region  ]3ring  between 
W.L.  3171  and  2190  tenth-metres.  The  methyl- 
ated benzenes,  toluene,  and  the  three  xylenes 
exhibit  a  similar  absorption,  requiring,  indeed, 
very  careful  measurement  to  distinguish  one 
from  the  other  (Hartley,  Chem.  8<x).  Trans. 
1885,  47,  685;  p^c.  B^Y-  ^^'  l^3>  ^>  A> 


570 


BENZENE   AND  ITS  H0M0L06UES. 


162;  Hartley  and  Dobbie,  Cliein.  Soc.  Trans. 
1898,  73,  605 ;  Baly  and  Collie,  ibid.  1905,  87, 
1332;  Friedericha,  Zeitech.  photochem.  1905, 
3,  154 ;  Grebe,  ibid,  376 ;  MiM,  ibid.  1909,  7, 
357  ;  1910,  8,  287  ;  Witte,  ibid.  1915,  14,  347 ; 
Ma8«>l  and  Faacon,  CSompt.  read.  1918,  166, 
819). 

Benzene  is  an  excellent  solyeni,  eaafly  dis- 
solving  caoutchouc  and  asphaltnm,  if  they  have 
not  been  exposed  to  lipht,  though  the  protective 
effect  of  the  lifl^ht  on  the  asphaltnm  is  bnt  slight, 
and  prolonged  treatment  with  benzene  canses 
it  to  dissolve.  Nearly  lUl  the  gnm  resins,  sol- 
phnr,  phosphoms,  fats,  oils,  most  of  the  natural 
alkaloids,  and  many  other  oiganio  compounds, 
are  soluble  in  it  It  has  also,  in  common  with 
carbon  disulphide,  the  property  of  dissolving 
iodine  with  production  of  a  violet  solution. 

Benzene  is  itself  soluble  to  a  very  sUght 
extent  in  water,  considerably  more  so  in  alcohol, 
whilst  ether,  glacial  acetic  add,  acetone,  and 
carbon  disulphide,  dissolve  it  readily. 

Benzene  boils  under  normal  pressure  at 
80*36''  (Regnault).  For  benzene  from  coal  tar, 
Adriaansz  found  8053''  to  80*62'' ;  and  for  that 
obtained  from  benzoic  acid  prepared  from  gum 
benzoin,  80-60"  to  8067* ;  80-f*  (oorr.)  Thorpe 
and  Rodger.  Its  specific  heat  at  temperatures 
between  -185*  and  +20*  is  0*176  (Nordmwer 
and  Bemonilli,  Ber.  Deut  physikal.  Ges. 
1907,  5,  175)  and  at  94*  is  0*4814  (Schlamp, 
Ann.  Phys.  Chem.  1896,  (iiL)  58,  759).  The 
latent  heat  of  vaporisation  is  94*37  (Griffiths 
and  Marshall,  Phil  Mag.  1896,  (v.)  41,  1)  or 
94*93  (Campbell  Brown,  Chem.  Soc.  Trans.  1905, 
87,  265). 

For  observations  on  its  thermal  expansion, 
«ee  Kopp  (Jahr.  1847-1848,  66),  Louguinine 
(Ann.  Chun.  Phys.  4,  11,  465),  Adriaansz  (BnlL 
Soc.  ohim.  20,  1873). 

The  vapour  when  inhaled  produces  giddiness 
and  ultimately  insensibility. 

Benzene  forms  with  picric  acid  the  molecular 
compound  C^KJiNOtUOKfCfi^,  which  melts 
with  decomposition  at  90*. 

Oxidising  agents,  such  as  potassium  per- 
manganate or  manganese  dioxide  and  sulphuric 
acid,  convert  it  into  formic,  propionic,  and  oxalic 
acids,  together  with  small  quantities  of  benzoic 
and  phthaUo  acids,  the  latter  substances  being 
produced  by  the  simultaneous  oxidation  of 
formic  acid  and  benzene,  the  process  of  condensa- 
tion resembling  that  occurring  in  the  conversion 
of  dimethylamline  into  metnyl  violet.  When 
strongly  heated  in  sealed  tubes  or  when  passed 
slowly  through  strongly  heated  open  tubes,  con- 
densation and  decomposition  go  on  together, 
acetylene,  diphenyl,  diphenylbenzene,  &c., 
being  formed  with  evolution  of  hydrogen  and 
deposition  of  carbon  (c/.  Smith  and  I^wcock, 
Chem.  Soc.  Trans.  1912,  101,  1453;  Zanetti 
and  Egloff,  J.  Ind.  Eng.  Chem  1917,  9,  350). 

There  can  be  little  doubt  that  toluene  and 

xylenes  can  also  be  produced  in  this  way,  and 

since  Berthelot  has  shown  that  toluene  and 

xylene  when  passed  through  strongly  heated 

tubes  can  produce  anthracene  and  naphthalene, 

and  since  he  also  obtained  anthracene  by  so 

treating  a  mixture  of  benzene  and  ethylene,  we 

"v  assume  that  if  benzene  is  not  the  mother 

ance  of  the  whole  series  of  hydrocarbons 

led  from  coal  tar,    it    is    yet    capable, 


under  pn^r  conditions,  of  generating  all  the 
othersL 

Vwpoor  of  benzene  mixed  with  hydrogen 
passed  over  finely  divided  nickel  li»i.ted  to 
170*^190''  yields  cyclohexane  C^His.  The  homo- 
Ipgues  of  benzene  behave  sinulariy. 

By^  passing  dry  ammonia  through  benzene 
containing  calcium  shavings  a  calcium-ammonia 
compound  Ga(NHs)4  is  formed,  which  with  the 
benzene  produces  duufdrobenzene  CgH^ : 

Ca(NHg)4=Ca(NH,),4-2N,H+H, 
Hj4-CgHg=CjHg 

(Dnmanski  and  Zvereva,  J.  Russ.  Phys.  Chem. 
Soc  1916,  48,  994). 

Whea  chlorine  acts  on  pure  benzene  in 
sunshine,  benzene  hexachloride  Cfijd^  ia 
formed.  The  substitution  of  chlorine  for 
hydrosea  in  the  nucleus  or  benzene  ring  is  a 
very  uow  operation  if  chlorine  alone  is  us^  but 
if  in  every  litre  of  benzene  about  10  grams  of 
iodine  are  dissolved,  and  the  liquid  kept  bculing 
while  a  brisk  ourrent  of  chlorine  is  passed  into 
it,  substitution  readily  takes  place  and  chlori- 
nated benzenes  are  produced.  The  reaction 
may  be  continued  until  the  whole  of  the  hydrogen 
is  replaced  with  production  of  hexachloro- 
benzene  C«Clf.  (For  the  electrolytic  chlori- 
nation  of  benzene  and  toluencj^  see  Name  and 
Maryott,  Amer.  J.  ScL  1913,  (iv.)  35,  153; 
Fichter  and  Glantzstein,  Ber.  1916,  49,  2473). 
Corresponding  bromine  and  iodine  compounds, 
and  mono-  and  j^di•fluoro-  derivatives  are 
known. 

When  subjected  to  the  action  of  strong  nitric 
acid  or  a  mixture  of  nitric  and  sulphuric  acids, 
substitution  of  hydrogen  by  NO^  takes  place  with 
great  ease.  If  the  mixture  is  kept  cool  onlv 
mononitrobenzene  is  formed,  but  if  heated, 
the  three  dinitrobenzenes  are  produced,  tiie 
metadinitro-  product  (m.p.  89*)  always  greaUy 
predominating.  The  ortho-  and  para-  com- 
pounds can  only  be  produced  in  quantity  by 
indirect  methods.  Trinitrobenzenes  can  only 
be  obtained  by  the  action  of  a  great  excess  of  a 
mixture  of  nitric  add  and  fuming  sulphuric  add. 

AU  the  nitro-  compounds  <m  reduction  with 
appropriate  reagents,  such  as  iron,  zinc,  or  tin, 
in  the  presence  of  add,  preferably  hydrochloric 
and  water,  yield  amino-  compounds  oorre- 
nK>nding  with  the  nitro-  compound  reduced 
Such  are  aniline  CgHg'NHg,  the  three  dia- 
minobenzenes  or  phenylenediamines 
C,H4(NH,)t,  Ac. 

The  amino-  compounds,  by  the  action  of 
nitrous  acid  or  nitrites  in  the  presence  ol  an 
excess  of  acid,  preferably  hydrochloric,  are 
converted  into  diazo-  compounds.  If  a  diazo- 
benzene  salt,  e.g.  CgH.*N|Cl,  is  dissolved  in 
absolute  alcohol,  and  the  solution  heated,  the 
nitrogen  is  evolved  as  gas  whilst  benzene  is 
regenerated  If  a  diazo-  salt  is  oissolved  in 
water  and  boiled  in  the  presence  of  an  add, 
nitrogen  is  also  evolved  and  the  correspondiug 
phenol  is  produced 

The  diazo-  compounds  react  with  certain 
amino-  compounds  or  phenols,  giving  rise  to  the 
almost  innumerable  series  of  dyes  known  as  aso- 
colourins  matters  {q.v.).  Solutions  cooled  with 
ice  should  be  employed,  and  all  rise  of  tempera- 
ture must  be  carefully  avoided  Under  propw 
conditions  9ome  diaao^  oomponndii  however^ 


BENZENE  AND  ITS  HOMOLOGUES. 


571 


attack  the  amino-  group  of  amino-  compounds, 
forming  diazoamino-  compounds  such  as  diazo- 
aminoMnzene  CgH^'N  :  N*NH'C,Hs.  These  can 
be  made  to  undergo  an  isomeric  change  resulting 
in  the  formation  of  what  are  known  as  aminoazo- 
compounds,  of  which  aminoazobenzeno 

C.HjN :  NC.H^NH, 

is  a  typical  example.  Such  substances,  when 
treated  with  a  reducing  agent,  split  up  into  an 
amine  and  a  paradiamine,  while  diazo-  com- 
pounds yield  hydrazines  only,  and  diazoamino- 
compounds  a  mixture  of  a  hydrazine  and  an 
amine. 

If  the  nitro-  compounds  are  submitted  to  the 
action  of  alkaline  reducing  agents  in  alcoholic 
solution,  such  as  a  mixture  of  zinc-dust  and 
alcoholic  soda,  the  reaction  takes  a  difiFerent 
course  altogether.  The  action  of  alcoholic  soda 
and  heat  alone  will  convert  mononitrobenzene 
into  Bzoxybenzene  GcE^'N  :  N'OgHg ;  this,  by 


li 


nascent  hydrogen,  is  conrerted  into  azobenzene 
CgH^'N  :  N'OsH,,  which  under  the  action  of  the 
same  reagent  is  still  further  reduced  to  hydrazo- 
benzene  C,H,-NH-NHC,Hg.  The  latter,  when 
treated  with  an  acid,  is  converted  into  a  salt  of 
benzidine  (paradiaminodiphenyl) 

NH.-CjH^CjH^NH, 

which  is  a  strongly  basic  compound  isomeric 
with  hydrazobenzene. 

When  heated  with  concentrated  sulphuric 
acid  or  treated  in  the  cold  with  solutions  of 
sulphur  trioxide  in  sulphuric  acid,  sulphonic 
acids  are  produced  by  suoetitution  of  HSO^  for 
hydrogen.  These  are  either  mono-,  di-,  or  poly- 
sulphonio  acids,  according  to  the  treatment 
adopted.  They  are  all  powerful  acids,  and 
form  well-defined  and  generally  well-crystaUised 
salts  with  sodium,  potassium,  and  ammonium, 
and  equally  definite,  though  leas  easily  crystal- 
Used  salts  with  calcium,  barium,  copper,  iron, 
eto.  Theee,  especially  the  sodium  or  potassium 
salts,' if  fused  with  caustic  potash  or  soda,  or 
heated  under  great  pressure  (40  atmospheres) 
with  aqueous  soda  or  potash,  are  decomposed 
with  production  of  a  sulphite  of  the  Hlkali  metal, 
and  conversion  of  the  benzene  residue  into 
the  corresponding  hydroxy-  or  phenolio  com- 
pound. 

Only  the  methyl  homologuesof  benzene  will 
be  considered  here,  as  these  are  the  chief  ones 
which  occur  in  coal-tar. 

The  monomethyl  derivative  is  known  as 
tokiene,  and  under  all  treatments  behaves  as  a 
completely  homogeneous  substance. 

The  dmiethyl  derivative  is  known  as  xylene, 
the  substance  of  that  name  occurring  in  coal 
tar^  which  ocouis  as  three  isomeric  compounds : 
Orihoxylene,  boiling  at  341*-142*,  whicn,  when 
gently  oxidised  with  weak  nitrio  acid,  gives  a 
toluic  acid  melting  at  102* ;  metoeyJene,  Doiling 
at  139*,  which  gives  a  toluic  acid  melting  at 
106*;  paraxyUne^  melting  at  16*,  and  boiling 
at  138*,  givine  a  toluic  acid  melting  at  178*. 

Each  of  these  difierent  xylenes  is,  however, 
absolutely  identical  in  peroentaoa  composition, 
and  this  isomerism  is  considered  to  be  due  to 
the  eonfiguraiion  of  the  molecule,  or,  in  other 
words,  to  the  positions  in  space  occupied  rela- 


tively to  each  other,  and  to  the  benzene  residue, 
by  the  two  substituting  molecules. 

This  method  of  regarding  the  coxistitution  of 
benzene  and  its  innumeraue  series  of  deriva- 
tives is  usually,  for  purposes  of  discussion,  in- 
vestigation, or  explanation,  represented  by 
drawing  a  hexagon  to  represent  the  molecule  of 

|«       s 
ll       s 

benzene,  the  six  angles  representing  the  six 
groups  of  CH  at  any  of  which  substitution  is 
supposed  to  take  place.  Since  only  one  mono- 
substitution  compound  of  a  given  kind  (i.e.  con- 
taining a  eiven  substituting  group)  is  known,  all 
the  six  CH-  groups  in  benzene  are  supposed  to  be 
of  equal  value.  The  fact  that  disubstitution 
compounds  exist  in  throe  distinct  isomeric  modi- 
fications (com^Mtre  the  above- mentioned  xylenes), 
is  explained  m  this  scheme  by  the  following 
suppositions  as  to  the  relative  positions  occupied 
by  the  substituting  ffroups.  First,  substitution 
is  supposed  to  take  mace  at  two  adjacent  ansles, 
e.g.  1  and  2,  2  and  3,  4  and  5,  &c.,  in  which 
case  the  word  orOuh  is  prefixed  to  the  name  o( 
the  substance,  as  orthodimethylbenzene  ^com- 
monly called  orthoxylene),  or  orthodichloro-, 
orthddibromo-,  or  orthodiamino-benzene,  etc. 
Or  the  substitution  is  supposed  to  take  place  at 
two  angles  not  adjacent,  but  with  one  inter- 
posing, as  at  1  and  3,  2  and  4,  or  1  and  5,  etc. 
in  this  case  the  product  is  indicated  by  the  prefix 
meta-,  as  metadimethylbenzene  (commonly 
called  metaxylene,  &c.  Lastly,  the  substitution 
is'supposed  to  take  place  at  opposite  angles,  such 
as  1  and  4,  2  and  5,  3  and  6,  etc.  In  such  a  case 
the  substance  is  known  as  a  para-  compound,  as 
paradimethylbencene,  or  paraxylene,  paradinitro 
benzene,  etc. 

This  theory  is  due  to  Kekul^,  and  satisfac- 
torily agrees  with  most  of  the  phenomena. 
(For  a  risumi  of  work  on  the  constitution  of 
benzene,  see  Kaufihnann,  Chem.  Zeitschr.  4, 
289;    HoUeman,   Chem.   Weekblad,    1915,   12, 

4400 

Toluene  and  xylene  generally  react  under 

similar  conditions  m  the  same  way  as  benzene, 
producing  a  similar  series  of  compounds.  Since, 
however,  toluene  itself  is  a  mono-  substituted 
benzene,  mono-  substituted  toluenes  are  really 
di-  derivatives  of  benzene.  For  instance,  there  is 
but  one  mononitrobenzene,  but  there  are  three 
mononitrotoliSenes.  There  are  three  dinitro- 
and  three  diamine-  benzenes,  but  there  are  six 
dinitrotoluenes  and  six  diaminotoluenefly  and 
so  on. 

^  It  is  to  be  borne  in  mind  that  in  all  substi- 
tution derivatives  higher  than  the  di-  substitution 
series,  the  number  of  possible  modifications  is 
greater  when  the  substituting  RTOups  ue  dis- 
similar than  when  they  are  aU  alike;  thus, 
idthough  thoe  are  only  three  isomeric  tri-  substi- 
tution compounds  of  the  formula  C«H|X's  or 
0«H,Y'„  there  are  six  such  compounds  of  ths 
formula  C,H,X',Y'. 

It  follows  that  the  xylenes  being  di-  deriva- 
tives, their  mono-  are  tri-  derivatives  of  benzene, 
and  conse<|uently  correspond  in  number  with 
the  di-  denvatives  of  toluene. 

The  introduction  di  the  methyl  group,  more- 
over, permits  of  another  kind  of    substitution 


672 


BENZENE  AND  ITS  H0M0L0GUE8. 


which  gives  rise  to  &  totally  different  class  of 
compounds  from  those  described  above  as  con- 
figurational  isomerides,  in  which  substitution 
takes  place  not  intho  benzene  nucleus,  but  in  the 
methyl  group  itself.  Such  substitution  ia  said  to 
be  eztra-muctear. 

Thus,  as  mentioned  above,  there  are  three 
substances  having  the  formula  C.H,o  known  as 
ortho-,  meta-,  or  para-zylene.  Tnese  isomerides 
are  represented  as  dimethylbenzenes  of  th6 
following  configurations:— 

CH,  CHg  CH, 

0™'  a.  0- 

but  there  is  another  0,Hjo  only  known  to  occur 
in  one  form,  and  always  behaving  as  a  mono- 
derivative  of  benzene ;  this  is  e t by  1  benzene 

CHjCH, 


0 


Just  as  in  this  case  a  methyl  group  has  been 
introduced  into  the  methyl  instead  of  into  the 
nucleus,  so  chlorine,  bromine,  &c.,  may  be  in- 
troduced, and  in  this  manner  such  compounds 
as  benzyl  chloride  C^H^'CHgCl,  the  di-  or  tri- 
chloride, benzaldehyde,  and  many  others  are 
formed. 

The  physical  properties  of  toluene  greatly 
resemble  those  of  benzene.  As  solvents,  there 
is  little  or  no  difference  in  their  powers,  and 
though  the  boiling-point  of  toluene  is  so  much 
higher  than  that  of  oenzene,  yet  in  a  current  of 
air  at  ordinary  temperatures  it  evaporates  nearly 
as  quickly. 

Toltiene  is  a  colourless  limpid  liquid  which 
solidifies  at  —94 '2®  (Ladenbuig  and  Krugel, 
Ber.  1899,  32, 1818)  or  -97**  to^99**  (Archibald, 
and  Mcintosh,  J.  Amer.  Chem.  Soc.  1904,  26, 
305).  Its  specific  gravity  is  less  than  that  ol 
benzene,  being  at  O""  0-882,  at  Ig""  0*872,  its 
index  of  refraction  at  25*5^  is  for  A  1*4709, 
D  1*4794,  H.  1*5090  (Gladstone  and  Dale),  at  8*5° 
for  Ha  1-49891  (Perkin). 

Toluene  boils  constantly  at  lll^  110*56'' 
(corr.)  (Thorpe  and  Rodger) ;  the  vapour  has 
much  the  same  physiological  effects  as  that  of 
benzene,  but  its  odour  is  decidedly  less  pleasant. 
If  ingested  into  the  stomach,  it  is  eliminated 
in  the  urine  as  hippuric  acid. 

Of  the  three  xylenes  the  meta-  is  chiefly  used 
in  commerce.  Orthoxylene  boils  at  141*^-1 42® 
144*07**  (corr.)  (Thorpe  and  Rodger).  Metaxy- 
lene  boils  at  139°,  and  its  specific  gravity  is 
0*8668  at  19°,  138*8°  (corr.)  (Thorpe  and  Rodger) ; 
sp.gr.  0*8812  (Pinette).  Paraxylene  boils  at 
138°,  and  at  19°  its  sp-sr.  is  0*8621,  138*23° 
(corr.)  (Thorpe  and  Rodger);  sp.gr.  0*8801 
(Pinette).  The  two  former  are  liquid  at  all 
temperatures  down  to  at  least  —  20  ,  but  para- 
xylene becomes  solid  when  exposed  to  a  freezing 
mixture,  and  when  once  frozen  it  only  melts 
at  16®. 

The  xylenes  are  distinctly  less  volatile  than 
toluene  and  benzene  in  an  air  current.  The 
emell  of  the  vapours  is  unpleasant  and  pungent. 


and  they  possess  the  power  of  producing  un- 
consciousness when  inhaled. 

Both  benzene  and  toluene  when  prepared 
from  coal  tar  are  accompanied  by  sulphur  com- 
pounds known  as  Ihiopni^^.  That  derived  from 
benzene,  no  doubt  by  the  action  of  sulphur  from 
the  pvrites  of  coal  at  a  high  temperature  during 
distillation  in  the  gas  retort,  is  represented  by 

the  formula  C^H^S  or  f     \ 

It  was  isolated  in  1882  by^V.  Meyer,  who 
obtained  by  constant  and  repeated  agitation 
with  sulphuric  acid  about  2  Jdlos  from  2000 
kilos  of  commercial  benzene.  It  is  a  colouriesa 
liquid,  boiling  constantly  at  84° ;  8p.gr.  at  15° 
1-100.  In  many  of  its  reactions  it  behaves 
exactly  like  benzene.     F.  Thiophkit. 

Two  thiotolens  corresponding  with  toluene. 
I.e.  being  methylthiophen,  are  known.  They 
both  boil  at  about  113',  sp.fi;r.  1-0194.  Hie  very 
minute  quantity  in  which  these  substances  oocur 
renders  them  '6i  no  industrial  importance,  even 
as  impurities. 

Benzene  was  first  isolated  by  Faraday  in 
1826,  in  the  liquid  separating  from  condensed  oil 

It  is  unnecessary  here  to  describe  the  pro- 
oesses  by  which  Mitscherlioh,  D'Arcet,  Kopp, 
and  many  others  obtained  benzene,  as  the  nrat 
pfacticaUy  industrial  process  was  that  of  Mans- 
neld,  founded  entirelv  at  first  on  Faraday's,  and 
dealing  with  a  similar  product  as  the  souxoe, 
namely,  coal  tar  (Mansfield,  Quart.  Jour.  Chem. 
Soo.  1848,  1,  244).  Mansfield  took  the  lower 
boiling  portion  of  coal  tar,  which  was  then  used 
under  the  name  of  naphtha  for  lighting  purpoaes, 
and  distilled  it  over  a  flame  in  a  stiU  provided 
with  a  jacketed  head  and  a  simple  form  of 
dephlegmator  made  by  oonneotinff  the  upper 
part  of  the  condensing  worm  with  tiie  still  body 
by  an  inclined  tube.  The  water  in  the  jaclret 
round  the  long  egg-shaped  head  partially  con- 
densed the  vapours  rising  from  the  bofling  fluid 
until  it  reached  a  temperature  of  100^,  when  those 
vapours  condensable  at  that  temperature  were 
alone  affected  and  returned  to  the  still,  those 
requiring  a  lower  temperature  passing  on  to  the 
worm,  and  being  condensed  and  collected.  Much 
of  the  spray  carried  upward  by  the  vapours  was 
stopped  in  the  head,  and  what  pawed  it  and  was 
condensed  in  the  connecting  tube  between  the 
still  head  and  the  worm  flowed  into  the  inclined 
tube,  and  found  its  way  back  to  the  body  of  the 
still.  Finally,  when  nothing  more  oould  pass 
the  boiling  water  in  the  jacl^ted  head,  this  in- 
clined tube,  on  a  cook  being  fully  opened,  which 
during  the  first  part  of  the  process  was  partially 
closed,  oould  be  made  use  of  to  distil  over  the 
higher  boiling  portions. 

Such  an  apparatus  could,  of  course,  only  effiect 
a  rough  separation  of  the  oil  into  a  *  benzol  * 
mainly  distilling  below  100°  and  a  'naphtha,' 
most  of  which  would  not  distil  below  100  . 

If,  however,  the  water  of  the  water  jaoket 
round  the  head  were  carefully  kept  at  a  stated 
temperature,  say  80°-82°,  a  much  purer  product 
could  be  obtained.  For  some  years  the  process 
was  only  carried  out  with  the  object  of  getting 
oils  for  the  Read  HoUiday  lamp,  and  for  Uie  use 
of  rubber  manufacturers. 


BBNZBNB  AMD   ITS  H0U0L0QUE3. 


A.  Still  bodr.     ■.  AuJrilaa  otdumn,     C.  CooIft  krpt  at  tcrnKTMnre  of  dliliiute  ««nt(d.    D,  CondoiMrlM 
pandbUiWe.    B.Vot"----'-'-'- -"-"■'-*-■ —     -  ■--        ■■ '-•-- 


674 


BENZENE  AND  ITS  HOMOLOGUES. 


The  early  demands  for  'benzol'  for  use  in 
the  aniline  colour  industry  were  confined  to 
what  were  known  as  30  p.o.,  SO  p.c.,  and  90  p.c. 
benzols,  which  terms  were  understood  to  mean 
that  30,  50,  or  90  p.c  by  measure  of  the  sample 
boiled  below  100^  Of  these  the  30  p.c.  was 
mainlv  used  for  the  production  of  aniline  for  red, 
and  the  90  p.c.  for  aniline  for  blue.  Mansfield 
had,  however,  subjected  his  distillates  to  a  care- 
ful but  most  laborious  fractionation  in  glass 
retorts,  finally  obtaining  perfectly  pure  benzene 
by  recourse  to  freezing  and  pressure,  and  he 
pointed  out  that  *  it  is  evident  that  any  of  the 
summary  processes  of  rectification  which  are 
practised  by  distillers  in  the  manufacture  of 
alcoholic  spirits  are  applicable  to  Uie  separa- 
tion of  benzole  from  the  less  volatile  fluids  of  the 
naphtha'  (Reports  of  the  Royal  College  of 
ChemistcT,  1849,  267). 

Biansfield,  in  fact,  in  the  remarkable  paper 
just  quoted,  laid  the  foundations  of  the  whole 
benzene  industry,  and  his  processes  with 
scarcely  a  change  are  in  use  to  this  day.  The 
departures  from  them  have  been  one  by  one 
abandoned  in  favour  of  his  method  of  araolute 
separation  of  the  light  oils  into  their  consti- 
tuents, and  it  is  not  too  much  to  say  that  had  it 
not  been  for  his  terrible  death  ^  in  Februaiy, 
1866,  we  should  have  had  the  pure  hydrocarbons 
in  the  market  many  years  ago. 

The  introduction  of  the  aniline  black  printing 
processes  and  other  improvements  in  the  dye 
mdustry,  however,  slowlv  save  rise  to  a  demand 
for  a  purer  benzene,  while  later  on  a  demand  for 
toluene  and  xylene  stimulated  the  improvement 
of  the  distillation  process. 

The  movement  was  naturally,  as  Mansfield 
had  suggested,  towards  the  use  of  such  a  still 
as  had  c>een  introduced  by  Mr.  Coffey  in  his 
patent  of  1832  and  subsequently  carried  to  great 
efficiency  bj  succeeding  generations  of  spirit 
distillers.  Coupier  of  Paris  appears  first  to  have 
worked  on  a  larao  scale  in  this  direction  about 
1803.  He  modified  the  original  Biansfield  appa- 
ratus in  the  way  mentioned  above,  and  showed 
that  at  one  operation  he  could  separate  ordinary 
60  p.c  commercial  benzol  as  follows : — 

100  lUres  yielded  t 
44  litres  between  80"*  and  82^  ('  Pure  benzol ') 
6    „  „        82*»  „  110**(Crude\oluol) 

17    „  „       110*»  „   112*»(*  Pure  toluol') 

6    „  „       112«  „  137*  (Crude  xylol) 

9    „  „       137*  „  140*  ('Pure  xylol') 

13-14    „  „       140^  „  160^  last  runnings. 

In  addition  there  were  about  6  litres  between 
62*  and  80*,  consisting  of  various  impurities 
such  as  carbon  disulphide,  acetonitrile,  etc. 

Vedl^,  Savalle  of  Paris,  and  others  followed 
with  various  improvements  in  the  same  direc- 
tion, Savalle  being  most  generally  considered  to 
have  produced  toe  best  still,  though  it  had 
two  great  drawbacks,  viz.  it  was  manufactured 
of  copper,  which  made  it  very  costly,  and  it  was 
hampered,  as  far  as  its  condensation  arrange- 
ments were  concerned,  by  an  expensive  and 
useless  attempt  to  use  air  from  a  fan 
driven  by  steiam  as  a  means  of  cooling  the 
condensers. 


*  Mansfield  was  burned  to  death  by  the  boiling  over 
'  <%  benzene  still. 


///■///■/■f  ,^y/''/o^.'^'r>.-^      '////r-7/- 


K  ^//.y//.v//2 


7!7////7.  '■■//////////yj^  •71. -n) 


7//  rrrf//  .'•        >i»kv// 


^  w/JV//-*'. 


The  latter  attempt  was  soon  given  up.  In 
Fig.  I  (p.  673)  is  seen  the  apfMun^tus  in  its 
latest  form  as  made 
by  the  Metallwerke 
vormals  T.  Aders,  of 
Magdebuxg-Neustadt. 
The  still  being 
charged      with      the 

.  proper     quantity    of 

I  napntha  or  crude  ben- 
zol, which  has  under- 

I  gone    the    necessary 

'  washings     with    sul- 
phuric acid  andsodium 
hydroxide,  steam  is  ad- 
mitted into  the  coils,  p.      « 
where  it  circulates,  the 

condensed  water  escaping  through  another  tube  in 
the  usual  fashion.  As  soon  as  the  liquid  begins 
to  boil,  the  vapour  ascends  into  the  head  a  and 

.passes  through  the  curved  tube  a*  into  the  bottom 
of  the  column  b.  This  contains  26  to  30  flat 
diaphragms,  each  pierced  with  a  number  of  small 
holes,  and  one  larger,  into  which  is  fitted  a  short 
wide  overflow  tuM,  the  end  of  which  stands  up 
about  2  inches  above  the  level  of  the  plate.  On 
the  opposite  side  of  the  plate  is  a  small  dej^eesioa 
about  2  inches  deep  and  4  inches  in  diameter,  inta 
which  the  overflow  tube  from  the  plate  above 
dips,  its  own  tube  dipping  in  the  same  way  into 
a  depression  in  the  p&te  bdow.  1^  condensed 
fluid  acta  to  each  overflow  tube  as  a  trap  (Fig.  2), 
and  prevents  the  ascent  of  vapour  through  it. 

llie  rising  vapour  condenses  rapidly  on  those 
plates,  and  the  fluid  thus  produced,  unable  to 
penetrate  the  small  holes  through  which  the 
hot  vapour  is  rushing,  rises  to  the  brim  of  the 
overflow  tube,  and  then  pours  down  from  plate 
to  plate  into  the  still  body.  The  non-con- 
densed vapour  rises  through  the  perforations 
of  the  next  plate,  ndiere  it  undergoes  a  similar 
operation,  and  so  on  to  the  top,  the  vapour 
passing  away  from  which  has  thus  been  succes- 
sively washed  by  bubbling  through  some  thirty 
layers  of  fluid,  each  slight^  cooler  than  the  one 
beneath.  Finally,  the  vapour  passes  through  a 
surface  or  multitubular  condenser,  c,  which  is 
provided  with  a  water  supply  so  regulated  that 
its  temperature  is  about  that  of  the  boiling- 
point  ot  the  liquid  required.  The  liquid  here 
condensed  flows  back  into  the  column  at  a  suit- 
able point,  while  the  now  purified  vapour  passes 
on  to  the  second  condenser,  d,  and  is  finally  com- 
pletely condensed  into  the  liquid  form.  Thence 
it  flows  into  the  glass  vase  B,  which  is  fitted  on 
to  a  stand-pipe  communicating  with  the  dis- 
tributing-pipes which  convey  it  to  the  store 
tanks.  The  fractions  taken  aliould  now  IkhI  as 
follows:  Benzene,  80*;  toluene,  110*;  xylene, 
140*. 

If  pure  products  are  required,  each  fraction 
is  washed  with  concentrated  sulphurio  acid, 
and  a  washing  with  soda  solution  foUows. 
The  fraction  is  introduced  into  a  cast-iron 
vessel  provided  with  a  lid  with  manhole  and 
inlet  pipe.  Through  the  centre  pasoeo  a  vertical 
shaft  rotated  by  mitre  geared  wheels.  The  diaft 
is  provided  with  arms  so  arranged  that  the  con- 
tents can  be  thoroughly  churned  up..  A  good 
form  of  apparatus  is  seen  in  Fig.  3.  The  details 
need  no  description  except  to  point  out  that  the 
screws  used  to  force  the  fluids  through  the  two 


BENZENE  AND  ITS  HOMOLOQOES. 


676 


,'  should  be  set  0 
revetwil  rigtit  ttn.  _. 
a  tluit  the  lowbr  one  csuses  the  lon-cr  fluid 
msh  up,  knd  the  upper  one  the  upper  fluid 
to  rush  down  ;  they  thus  ouse  the  two  ourrent* 
to  Dieot  together  violently  and  thoroughly 
taingle.  The  centre  dwft  nay  also  consist  of 
an  Archimodean  screw  or  of  a  truncated  hollow 


Fra.  3. 
cone.     Air  agitation  is  not  advisable  on  account 
of  the  loss  of  heniol  which  it  is  apt  to  cause. 

If  the  fraction  is  of  fairly  good  quality  and 
has  been  pi«P«f')'  separated  from  the  crude 
benio)  or  light  oils,  the  amount  of  acid  required 
need  not  be  more  than  ono-twentieth  of  ita 
weight.  In  some  oases,  however,  where  the 
impurities  are  difficult  to  remove,  more  must 
be  used,  and  the  operation  repeated.  After 
the  aoid  haa  been  run  oS,  a  waihiiig  with  enough 
soda  solution  to  neutralise  excess  of  acid  and 
remove  traces  of  phenols  follows,  and  the  frac- 
tion is  then  i««dy  for  a  aecond  rectification. 

If  crude  naphtiia  has  been  used  to  charge 
the  still.it  will  have  yielded,  i/Uer  olio,  60  p-o.  or 
BO  p.c.  beniol  according  to  requirements.  On 
redistillation,   100  parte  of  the   former  should 

field  4S-iS  parts  of  pure  beiuene,  and  from 
00  Mrta  of  the  latt«r  TO  parte  of  pure  beniene 
ahould  bo  obtained. 

When  rC'rectifled,  the  benzene  and  toluene 
should  eaoh  distil  constantly  within  0-6*  and 
1-0*  respectively,  and  the  xylene  within  S*. 

The  treatment  for  obtaining  toluene  is  exactly 
the  same  as  tliat  described  for  benione,  the 
toluene  following;  the  benzene  from  the  crude 
benzol  still  and  being  subaequently  re-rectiSed. 
Toluene  is  also  accompanied  by  the  coireapond- 
ing  thiophen  (thiotolen),  and  requires  very 
CBjeful  and  thorough  washing  with  sulphuric 
aoid,  or  It  cannot  be  properly  nitrated. 

After  the  separation  of  the  toluene,  more  or 
lea  onide  lykne  is  obtained,  and  the  residue 
in  the  still  is  then  cooled  and  nm  out.  When 
good  crude  bentol  has  been  worked,  the  residue 
contains  a  very  large  quantity  of  naphthalene. 


'hioh  separates  from  it  when  cold,  and  is  known 
1  the  uorks  as  '  naphthalene  salts.'  As  it  has 
all  been  brought  oS  from  the  tor  at  a  low  tem- 
perature, it  is  extremely  free  from  higher  boiling 
substances,  and  very  pure  naphthalene  can  be 
obtained  hom  it  witn  little  trouble.  Of  the 
some  20-30  p.c.  consists  of  phenol,  to 
which  the  same  remarks  apply.  The  remaining 
third  oonaista  of  »  mixture  of  hydrocarbons 
from  which  some  more  xylene  could  no  doubt 
'Covered,  but  the  bulk  of  this  '  dead  oil,'  as 
it  is  often  called,  is  used  for  burnine.  Mcta- 
xykne  oan  be  prepared  from  the  purihed  mixed 
xylenes  by  agitation  with  lulphuria  acid,  aa 
desoribed  for  wniene  and  toluene,  to  Mmove  the 
tJhiophena,  when  a  subsequent  treatment  with 
''a  own  weight  of  sulphuric  acid  converts  the 
letazylene  mto  a  sufphonio  acid,  vhich  after 
separation  from  the  insoluble  portion  is  hydro- 
lysed,  and  metaxylene  of  great  purity  obtained. 

iSenzene,  it  u  alAted,  la  formed  'by'pauing 
the  vapour  of  petroleum  mixed  with  hydrogen 
through  a  tube  containing  a  suitable  catalyst — - 
iron,  cupper,  zinc,  nickel,  &,c. — at  a  temperature 
between  180°  and  3U0°  (Eng.  Pat  17272,  IB13  ; 
20470,  1913  :  2S38,  1914}. 

Benzene  and  toluene  may  be  obtained  by 
the  demethylation  or  '  cracking  '  of  the  higher 
benzenoid  hydncarbons.  The  optimum  tem- 
perature* for  the  production  of  benzene  and 
toluene  are  respectively  800°  and  7S0°,  the 
solvent  naphtha  containing  the  higher  hydro- 
carbons being  passed  through  a  heated  steel  tube 
under  a  pressure  of  II  atmospheres.  About 
25  p.c.  of  the  solvent  naphtha  is  demethylated, 
the  percentage  yields  of  benzene  and  toluene 
at  the  foregoing  temporaturee  being  1&'9  and 
20'6  respectively  (Eglol!  and  Moore,  J.  Soc. 
Chcm.  Ind.  1917, 36, 128 ;  G.  T.  Morgan,  Report 
(or  1017,  J.  Soc.  Chem.  Ind.). 

Valuaiion  of  Commtrciai  '  Pure  Bensol.'^Aa 
stat«d  above,  the  whole  should  boil  within  06° 
of  the  correct  boiling-point.  It  should  give  no 
cijstalline  precipitate  on  standing,  with  a  few 
drops  of  phenylhydrazine  (lest  for  carbon 
disulphide}.  When  shaken  with  concentrated 
sulphuric  acid  the  latter  should  be  only  slightly 
daAened  (thiophen  or  aliphatic  hydrocarbons). 
On  sbaiting  with  sulphuric  acid  and  a  trace  of 
isatin,  no  blue  colouration  should  be  produced 
(thiophen).  On  treatment  with  a  miituiv  of 
nitric  and  sulphuric  acids,  and  subsequent  dis- 
tillation in  a  current  of  steam,  no  unnitrated 
hydrocarbons  should  be  obtained  (aliphatic 
hydrocarbons).  Lastly,  it  should  aolidify  when 
cooled  below  0°. 

PtiTs  toluene  of  commerce  ehould  not  import 
any  colouration  to  vnlphuria  acid  when  shaken 
with  it.  On  shaking  DO  c.c.  of  toluene  with 
10  c.c  of  nitric  acid  (sp.gr.  1-44)  in  a  stoppered 
bottle,  the  acid  should  assume  only  a  red  colour, 
remain  quite  clear  and  bright,  not  turning 
greenish  or  blackish.  (For  much  information  aa 
to  the  commercial  valuation  o(  '  benzols,'  see 
Lunge,  Coal  Tar  and  Ammonia,  Hth  ed.  1916  ; 
and  Northall-Laurie,  Analyst,  lOte,  40,  3S4  ; 
James,  J.  Soc.  Chem.  Ind.  19I<1,  35,  236; 
Spielmann  and  .Tonfs,  Hiid.  911  ;  1917,  36,  4811 ; 
Spielmann  and  Wheeler,  il'id.  396  ;  Edwards, 
Aid.  687  j  Wilson  and  Roberta,  J.  Gaa  Lighting, 
1918,  134,  22D;  Harker,  J.  Roy.  Soc.  New 
South  Wales,   IQLQ    50,  Wi    Egloff,  Met.  and 


076 


BENZENE  AND  ITS  HOMOLOGUES. 


Chem.   Eng.    1917»    16,   259 ;    Jones,  J.   Soc.  I  facture  in   1817   from  coal-tar  benzene.    The 


Chem.  Ind.  1918,  37,  324 ;  Weiss,  J.  Ind.  Eng. 
Chem.  1918,  10,  1006.) 

NUralian  of  Benzene,  Toluene,  etc. — ^Nitro- 
benzene first  made  its  appearance  in  the  arts 
mider  the  name  of  eseence  de  myrbane,  manu- 
factured in  France  by  Coilas.  It  was  used  to 
scent  soap  and  as  a  bitter-almond  flavouring. 
Mansfield  had  taken  out  a  patent  for  its  manu- 


usual  arnuurement  now  adopted  for  its  manu- 
facture  {see  Fig.  4)  is  as  follows :  ^ — 

The  nitra&ig  pan  has  a  tots!  capacity  of 
1600  gallons,  and  is  capable  of  treating  500 

fallons  or  4420  lbs.  of  oenzol  in  one  charge, 
t  is  of  cast  iron,  1}  inches  thick,  the  aides,  from 
the  lid  down  to  a  depth  of  3  feet,  being  |  inch 
thicker.    The  vertical  agitating  shaft  is  sns- 


Fio.  4. 


A,  Mbced-acid  pan. 

B,  GompresBed-alr  pipe. 

C,  Sulphuric  acid  inlet. 

D,  Nitric  acid  Inlet. 

E,  Acid-vapour  pipe. 

F,  Nitrobenzene  pan. 


O,  Thermometer. 
H,  Propeller  agitator. 
Jj  Lead  cooliDg-foilB. 
K,  SupDorting  grids. 
L,  CooUng-water  outlet. 
H,    do.        do.      do. 


N»  Cooling-water  Inlet. 
O,    Do.       do.     do. 


pended  from  the  lid  on  ball  bearings,  and  carrier 
two  propellor  agitators.  The  internal  cooling 
pipes  consist  of  two  separate  coils  of  thin  lead 
pipe  2  inches  diameter,  each  coil  being  about 
150  feet  long.  They  are  supported  on  ciroular 
oast-tfon  srates  or  tables,  as  Aown.  The  coils 
<^re  spaoea  out  so  as  to  allow  free  passage  of 
liquid  between  them.  To  direct  the  upward 
of  the  liquid,  the  lower  propellor  agitator  is 


T,  Nltrobenxen^pipe. 

V,  Compreued-air  pipe. 
P,  CompresMcd-alr  pipe.       V,  Waste^cld  pipe. 
Q,  Water  inlet.  W,  Pipe  to  N.  B.  tank. 

B,  Nitrobenzene  wathpan.  X,  Alr-piesaore  egg. 
8,  Pipe  from  egg. 

surrounded  by  a  cast-iron  cylinder  with  large 
perforations  at  the  bottom  to  admit  the  descend- 
ing liquid.  This  serves  also  as  a  support  for 
the  grates  and  coils.  Five  hundred  gallons  of 
pure  benzol  are  first  run  by  sravity  into  the 
machine.    The  acid-mizlng  tank,  wmch  stands 

I  See  Chdm.  Trade  Jour.  1906.  88,  60.  The  writer  b 
indebted  to  Messrs.  Davis  Bios,  for  permtsskm  to 
reproduce  the  sketch  of  the  apparatus. 


BENZENE  AND  ITS  HOMOLOOUES. 


577 


aboTO,  IB  charged  with  5000  Ibe.  of  nitric  acid, 
1-43  8T>.gr.  or  8d^w.,  and  6600  Iba.  of  sulphuric 
acid  of  ^  p.c,  and  these  are  thoroughly  mixed  by 
air  agitation.  In  some  factories  the  acids  are 
mixed  in  the  above  proportions  in  large  stock 
tanks.  The  mixed  acid  is  run  in  a  thin  stream 
into  the  benzol,  while  the  agitators  are  revolving 
at  a  speed  of  about  60  revs,  per  minute.  The 
heat  of  the  reaction  is  indicated  on  a  Ions 
thermometer  suspended  in  a  metal  tube,  which 
passes  through  the  lid  and  dips  into  the  liquid. 
The  temperature  is  kept  below  60^  by  checking 
the  flow  of  aoids  if  the  temperature  rises.  With 
a  good  supply  of  cooling  water  passing  tlirough 
the  coils,  very  little  attention  is  required,  and 
the  process,  which  a  few  years  ago  was  attended 
with  danger  and  frequent  loss,  is  now  carried 
on  almost  automatically.  This  is  principally 
owing  to  the  purity  of  the  benzol  employed,  and 
the  use  of  internal  cooling  coils  in  place  of  the 
outside  water-jacket. 

It  is  important  that  the  coils  should  be  of 
pure  chemical  lead,  without  flaw,  and  before 
being  used,  they  should  be  examined  minutely. 
Some  of  these  coils  have  been  known  to  work 
nearly  4  years  continuously.  The  vertical 
portions,  connecting  the  coils  with  the  exterior, 
should  be  urotected,  as  these  are  quickly 
attacked.  This  is  done  by  '  threading '  them 
through  lead  pipes  of  slightly  larger  diameter, 
and  mlinff  up  tne  intervening  space  with  any 
acid-proof  cement.  After  the  full  charge  of 
mixed  aoids  has  been  run  into  the  machine, 
the  agitation  is  continued  for  about  4}  hours, 
and  tne  benzol  will  then  be  completely  trans- 
formed into  nitrobenzol.  If  a  sample  is  then 
taken  while  the  agitators  are  running,  and 
flJlowed  to  setUe,  tne  weak  sulphuric  (called 
waste  acid)  will  contain  less  than  1  p.o.  of  nitric 
aoid,  and  the  upper  layer  of  nitrobenzol  will 
have  a  sp.gr.  of  1-235.  The  aeitation  is  then 
stopped,  and  the  contents  of  the  machine 
allowed  to  settle  for  5  hours.  The  *  waste 
acid,'  having  settled  to  the  bottom,  is  run  off 
into  the  air-pressure  egg  below,  and  blown  to 
the  sulphuric  acid  concentrating  deportment  to 
be  rectified.  The  nitrobenzol  is  next  run  off 
into  the  air-pressure  egg  and  blown  into  the 
washing  pan  above,  ^ere  it  is  washed  by 
violent  air  a^tation  with  an  equal  volume  of 
water  containing  sufficient  sodium  hydroxide 
to  neutralise  any  trace  of  acid  left  in  it.  After 
settling- a  few  hours  the  nitrobenzol  settles  to 
the  bottom,  and  is  run  down  into  the  air-pressure 
effg,  and  forced  from  there  into  a  large  store  tank, 
^^oh  is  set  at  a  hich  level,  so  that  the  contents 
oan  run  by  gravity  to  the  aniline  machine. 
The  wash-water,  which  contains  a  little  nitro- 
benzol in  suspension,  is  run  into  a  series  of 
settling  tanks,  and  the  oil  recovered.  Although 
it  is  possible  to  work  a  charge  of  benzol  in  each 
macnine  daily,  it  is  customary  to  have  a  duplicate 
set  of  machmes,  and  to  work  each  machme  on 
alternate  days.  For  an  output  of  160  tons  of 
pure  aniline  o3  per  month,  six  nitrobenzol 
machines  are  required,  with  their  corresxx)nding 
adjuncts,  as  shown  in  the  figure.  The  yield  of 
nitroboizol  from  the  pure  touzoI  employed  is 
154}  p.a  by  weight,  and  this  approaches  so 
near  tne  theoretical  yield,  via.  167H9  p.c.,  that 
there  is  little  room  for  improvement.  It  is 
possible    slightly    to    increase    this    yield    by 

Vol.  I.— y. 


settlinff  the  waste  acid  for  48  hours  in  a  series 
of  tazuKS,  and  skimming  off  the  nitrobenzol, 
but  in  practice  it  has  not  been  found  to  pay 
for  the  toouble,  especially  if  the  previous  separa- 
tion be  earefully  watched.^  Several  pumts 
have  been  proposed  for  the  continuous  process 
of  nitration  of  benzene,  the  hydrocarbon  and 
nitrating  acid  being  led  into  the  apparatus  at 
certain  points  and  the  nitrobenzene  emerging 
at  another  {see  Gain,  The  Manufacture  of 
Intermediate  Products  for  Dyes,  Macmillan, 
1918). 

For  a  cryofcopic  method  of  determining 
nitrobenzene  in  commercial  nitrobenzenes,  see 
Simpson  and  Jones,  J.  Soc.  Chem.  Ind.  1919, 
3S,  325 ;  Analyst,  1919,  379. 

When  the  nitrobenzol  is  to  be  sold  as 
'  myrbane,*  it  is  distilled  under  diminished 
pressure  in  order  to  obtain  a  perfectly  clear  and 
transparent  liquid  such  as  the  users  of  myrbane 
demand.  It  is  customary  to  use  toluene  im- 
perfectly freed  from  benzene  for  this  purpose, 
that  article  being  cheaper  and  yielding  a  some- 
what more  fragrant  mvrbane  than  benzene  alone. 

The  treatment  adopted  with  toluene  and 
xylene  is  in  all  essential  particulars  the  same  as 
with  benzene.  In  the  former  case,  however,  if 
the  nitrotoluene  is  not  employed  direct,  the 
product  is  separated  into  p-  and  o-nitrotoluene 
by  fractional  distillation  under  diminished  pres- 
sure through  a  Savalle  coin  ma.  The  distillation 
is  stopped  when  40  p.c.  has  distilled,  and  the 
distillate  on  redistillation  gives  nearlv  pure 
o-nitrotoluene  (b.p.  233*).  The  residue  on 
cooling  deposits  crvstals  of  |7-nitrotoluene 
(b.p.  238*;  m.p.  54*),  which  are  freed  from 
oil  by  centrifu^atin^. 

(For  the  estimation  of  o-  and  |>-nitrotoluene, 
see  Beverdin  and  De  la  Harpe,  BulL  Soc.  chim. 
1888,  (ii.)  50,  44;  Glasmann,  Ser.  1903,  86,  4260  ; 
Ghenu  Zeit.  1904,  28,  187 ;  HoUeman,  Froc.  K. 
Akad.  Amsterdam,  1904,  7,  395;  Bee.  trav. 
chim.  1908,  27,  458.) 

JHnUrcbengene  and  dinitrotaluene  are  obtained 
by  treating  a  chai^  of  the  hydrocarbon  with 
double  the  ijroportion  of  the  mixed  acids,  the 
operation  being  carried  out  in  two  stages,  and 
the  second  charge  of  acids  run  in  directly  after 
the  first.  The  cooling  water  is  shut  off  and  the 
temperature  allowed  to  rise  rapidly.  Or  nitro- 
benzol already  manufactured  may  be  taken 
and  again  treated  with  the  necessary  acid. 

The  product  of  the  reaction  is  separated  from 
the  ada  as  usual,  and  then  thoroughly  washed 
witb  cold,  and  lastly  with  hot,  water.  As 
dinitrobenzene  is  sensibly  soluble  in  the  latter, 
the  hot  wash-water  had  better  always  be  pre- 
served and  used  for  first  washing  a  subsequent 
batch:  Finally,  it  is  allowed  to  settle,  and, 
while  still  warm,  run  out  into  iron  trays,  in 
which  it  solidifies  in  masses  2  to  4  inches  thick. 
The  principal  product  of  the  reaction  is  met a- 

1  Benzene  may  also  be  nitrated  by  using  sodium 
nitrate  instead  of  nitric  acid.  For  example :  86  klloa. 
of  benzene  aad  115  kilos,  of  sodiam  nitrate  are  mixed 
at  eo^'-SO",  and  160  kilos,  of  90-96  p.c.  eulpharlo  add 
added  slowly.  The  temperature  rises  to  about  lOO*, 
when  66  kilos,  of  benzene  are  added,  and  when  the 
nitration  Is  complete  the  lower  layer  of  blsnlphate  is 
drawn  off.  The  yield  is  stated  to  be  160-154  kilos,  of 
washed  nitrobenzene,  sp.gr.  1*18  at  16*,  or  148  kilos,  of 
the  pure  substance  bollmg  at  96*  under  a  pressure 
of  Id  mm.  (Saccharln.fAbrlk.  Akt.-Oes.  vorin.  Fahl- 
berg,  List  &  Co.  D.  R.  p,  221787  ;  F.  P.  401679), 

2  V 


578 


BENZENE  AND  ITS  HOMOLOQUES. 


dinitrobenzene,  m.p.  S9'8^  but  orthodi- 
nitrobenzene,  m.p.  118*,  and  p*aradinitro- 
benzene,  nLp.  172^  are  also  proauoed,  the  m.p. 
of  the  oommeroial  product  bemg  about  85*-87  . 
It  should  not  contain  anv  nitrobenzene,  and 
should  be  w^  orystaUiBed,  hard,  and  aJmoet 
odourless,  and  shoiud  not  render  paper  greasy. 

DinUrotoluene  is  prepared  by  a  process 
similar  to  the  above,  and,  since  ortho-  and 
para-nitrotoluene  yield,  when  nitrated  at  a  high 
temperature,  inost  of  the  2  :  4-dinitrotoluene, 
it  is  better  to  proceed  straight  on  from  the 
toluene.^ 

The  subsequent  treatment  is  the  same  as 
when  dinitrolMnzene  is  manufactured.  Com 
mercial  dinitrotoluene  consists  mainly  of  the 
last-named  and  the  2 : 6-  modifications,  but 
always  contains  small  quantities  of  the  other 
isomerides.  The  2  r6-  only  occurs  in  small  pre- 
portion,  and  mainly  in  the  oily  draiuings  uom 
the  crude  product.  The  nitration  of  the  pure 
metazylene  does  not  differ  from  the  processes 
already  described. 

To  obtain  the  more  highly  nitrated  deriva- 
tives  nitrosyl  sulphate  may  be  employed,  m- 
DiriUrcbenzAne  (1  part)  is  slowly  heated  with 
nitrosyl  sulphate  (2  parts)  until  dissolved,  when 
nitric  acid  (2  parts)  is  added  and  the  mixture 
maintained  at  100^-120®  until  s-irinilnbemene 
is  produced  (Heinemann,  Eng.  Pat.  102216  of 
1916). 

TrifiUrotoluene.  There  are  six  possible 
isomerides  of  this  compound,  viz. : — 

a  or  2.4.6  trinitrotoluene.  •      80*8*^* 

i9  or  2.3.4  „  .  .112** 

7  or  2.4.5  „  .  .       104** 

a  or  3.4.5  ,.  .  .    137 -G** 

cor  2.3.6  „  .  .      97*2'' 

(or  2.3.6  „  .      79-6* 

All  of  them  are  of  practically  equal  value 
as  explosives,  but  the  best-known  is  the  a- 
compound,  the  product  known  as  T.N.T.,  or 
trotyl  or  trilite.  The  other  isomerides  in  the 
commercial  product  are  derived  from  m-nitro- 
toluene,  which  is  present  in  the  ordinary  mono- 
nitrotoluene  to  the  extent  of  4-^  p.c.  The 
various  trinitrotoluenes  give  different  coloura- 
tions with  acetone  and  ammonia,  viz.  a,  deep 
red ;  ^,  greenish-yellow ;  y,  blue ;  (,  orange- 
red  ;  and  c,  rose-red. 

In  the  manufacture  of  a-trinitrotoluene 
(T.N.T.),  mononitrotoluene  is  first  prepared  by 
using  the  waste  acid  resulting  from  the  manu- 
facturinff  process.  The  nitration  is  carried  out 
in  a  jacketed  apparatus  provided  with  rotating 
arms.  The  toluene  is  run  into  the  apparatus, 
and  whilst  it  lb  kept  agitated,  the  waste  acid 
and  fresh  nitric  acid  are  added.  The  temfiera- 
ture  is  kept  below  30*.  After  setting  .for  six 
hours  the  mononitrotoluene  is  separated  from 
the  waste  acid.  To  the  latter  fuming  sulphuric 
acid  and  nitric  acid  are  added.  Tins  fresh 
mixture  is  added  to  the  mononitrotoluene  in 
the  agitating  vessel,  and  kept  in  oontinuoufi 
motion  for  six  hours  at  a  temperature  of  90*. 
The  steam  is  then  shut  off  in  the  jacket,  agita- 
tion is  discontinued,  and  cold  water  and  finally 


^  For  a  detailed  description  of  the  manufacture,  _ 
Kayser.  Zeitsch.  Farb.  Ind.  1003,  2,  16,  31.  Cf,  Kldo- 
koro,  J.  Chem.  Ind.  Tokyo,  1017,  20,  460;  J.  Soc. 
Chem.  Ind.  1017,  86  1065. 


a  refrigerated  liquid  at  2*  are  passed  round  the 
jacket.  The  dinitrotoluene  is  Uius  crystallised 
out  in  the  mixing  vessel,  and  the  waste  acid 
can  be  run  off.  The  latter  is  revivified  by  the 
addition  of  fuming  sulphuric  acid,  and  this 
fresh  mixture  is  Mded  to  the  diaitrotoluene. 
After  warming  and  agitating  nitric  acid  is 
added  and  the  temperature  raiwd  veiy  gradually 
to  92*.  After  heating  for  twenty  hours  the 
whole  of  the  contents  of  the  vessel  is  run  into 
cooling  tanks,  where  the  trinitrotoluene  is 
allowed  to  crystallise  out  slowly,  during  some 
four  to  five  days.  The  waste  acid  is  then 
separated  and  used  for  the  preparation  of  mono- 
nitroluene.  The  trinitrotoluene  is  washed  with 
water,  ground  under  edge  runners,  and  finally 
washed  in  an  alkali  solution.  It  is  then  dis- 
solved in  acetone,  and  sodium  carbonate  is 
added.  The  solution  is  heated  in  a  steam- 
jacketed  vessel  for  four  hours,  after  which  the 
acetone  is  distilled  off  and  condensed,  and  the 
molten  trinitrotoluene  is  run  into  cooling 
vessels  to  ciystallise  out.  The  crystals  ace 
thoroughly  washed  with  water,  dissolved  in 
hot  96  p.c.  alcohol,  the  solution  filtered  and 
allowed  to  crystallise  (Vasquez,  Z.  gee.  Sohiees-  a. 
Sprengstoffw.  1911,  6,  301;  J.  Soa  Chem. 
Ind.  1911,30,  1046). 

lisngenscheidt  (Z.  ges.  Schieas-  u.  Spreng- 
stoffw. 1912,  7,  426)  describes  the  process  as 
follows : 

A  mixed   acid   (1400   kilos),  oonsiBting   of 
equal  quantities  of  sulphuric  acid  and  nitric 
acid  (94-95  p.c.),  is  allowed  to  fiow  dowly  into 
a    cast-iron   vessel    containing    a   solution    of 
orthonitrotoluene  (500  kilos)  m  sulphuric  acid 
(1400  kilos  of  100  p.c.  acid)  which  has  been 
warmed    to    OOMO^    This   vessel   is   steam- 
jacketed,  and  has  also  water-cooling  coils,  and 
a  screw  agitator,  which  runs  at  about  182  revohi- 
tions  per  minute.    At  the  commencement  the 
temperature  of  the  mixture  is  prevented  from 
rising  bv  means  of  the  water  coils  until  the 
whole  of  the  orthonitrotoluene  is  converted  into 
dinitrotoluene.    Steam  is  now  passed  through 
the  jacket  to  start  the  conversion  of  the  dini- 
trotoluene into  trinitrotoluene,  and  the  tempera- 
ture is  not  allowed  to  rise  above  160**.     When 
nitration  is  complete,  the  temperature  is  main- 
tained at  this  point  for  one  hour.    It  is  then 
allowed  to  fall  to  lOO"",  and  200  titres  of  water 
are  added  in  order  to  increase  the  yield.    The 
molten   trinitrotoluene  is  separatea  from   the 
acid  and  washed  until  neutral.    This  product 
hajs  a  m.p.  of  72M4^,  and  Lb  used  in  the  ammo- 
nium nitrate  class  of  explosives.    To  produce 
the   trinitrotoluene   of  higher   m.p.    (81^-82*), 
which  is  used  for  filling  shdls,  the  lower  melting 
product  (600  kilos)  is  dissolved  in  2300  litreeS 
a  mixture  of  90  p.c.  alcohol  containing  6-10 
p.c.  of  benzene,  and,  after  filtering,  the  solution 
18  crystallised  in  a  water-jacketed  enamelled 
pan.     By   evaporating   the   mother   liquor   to 
one-third  of  its  bulk,  a  quantity  of  browmsh- 
coloured  crystals  are  obtained,  which  are  used 
in  the  ammonium  nitrate  class  of  explosives, 
whilst,  on  further   evaporation,  a  danc-brown 
or  red  liquid  (16-6-17*2  p.c  N)  is  obtained, 
which  is  used  in  the  explosive  industry  for 
gelatinising  collodion  cotton  under  the  name  of 
Bquid  trimtrotoluene  (J.  Soc  Chem.  Ind.  1912, 
31,  1147). 


BENZO-AUBTNE. 


579 


The  chief  difficulties  in  the  nittaiion  piocees 
Aie  due  to  the  presence  ol  inoiganic  impurities, 
chieBy  lead  and  iron  salts,  derived  from  the 
snlphurio  acid  and  from  the  action  of  the 
nitrating  acid  on  the  apparatus,  and  organic 
by-products  formed  by  sulphonationy  oxidation, 
and  reduction.  Amon^  the  by-products  may 
be:  (1)  Trinitrobenzoio  acid  or  tetranitro- 
methane,  owing  to  oxidation  in  case  of  over- 
heating or  pressure;  the  last-named  may  be 
reoogiuBed  by  its  intense  odour;  metallic  salts 
may  act  as  catalysts  in  promoting  oxidation. 
(2)  Phenolic  compounds,  such  as  cresols,  formed 
by  the  reduction  of  the  nitro-  compounds  by 
hydrogen  produced  by  the  action  of  the  nitrating 
acid  on  the  apparatus,  the  amino-  compounds 
being  then  converted  into  diazo-  and  hydroxy- 
oomnounds;  in  presence  of  metaUic  salts^ 
higmy  explosive  salts  of  nitro-cresols  may  be 
formed.  (3)  Sulphonic  adds  owing  to  too  low 
a  concentration  of  nitric  acid.  To  obtain  good 
results  the  following  conditions  should  be 
observed:  (1)  The  amount  of  nitric  add  used 
should  exceed  the  theoretical  quantity  by  at 
least  I  moL  (2)  The  degree  of  nitration  should 
be  controlled  by  the  concentration  of  nitrating 
acid,  temperature,  and  duration  of  reaction 
ratiier  thiMi  by  the  actual  quantity  of  nitric 
add  used.  (3)  The  reaction  product  should  be 
separated  from  the  spent  acid  as  quickly  as 
possible.  (4)  The  action  ol  the  nitrating  acid 
on  the  apparatus  should  be  reduced  to  a  minimum 
by  suitable  choice  of  material  and  concentration 
of  add  (Gojpisarow). 

The  following  bibliography  has  been  com- 

Siled  by  Gopisarow  (J.  Soc  Ghem.  Ind.  1015, 
i,  1169) :~ 
Wilbrand,  Annalen,  1863,  128,  178 ;  Hepp, 
Annalen,  1882,  215,  366;  St&del,  Annalen, 
1890,  259,  208 ;  H&ussermann,  J.  Soa  Chem 
Ind.  1891,  1028 ;  1892,  236 ;  Bichel,  Fr.  Pats. 
357,  925,  3691371,  1906 ;  J.  Soc.  Chem.  Ind. 
1900,  135  ;  1907,  115  ;  RudelofiF,  J.  Soc  CheuL 
Ind.  1907,  67;  Escales,  Z.  ges.  Schiess-  u. 
Sprengstoffw.  1908,  3,  21;  Nobd  A  Co., 
D.  R.  P.  212169;  J.  Soc  Chem.  Ind.  1909, 
1065 ;  Van  den  Arend,  Rec  trav.  chim.  1909, 
28,  408 ;  Vender,  Eng.  Pat  18281,  1909 ;  J. 
Soc.  Chem.  Ind  1910,  265;  Com^,  J.  Ind. 
Eng.  Chem.  1910,  2,  103:  Vasgues,  J.  Soa 
Chem.  Ind.  1911,  1046 ;  Verola,  J.  Soa  Chem. 
Ind.  1912,  152 ;  Dautriche,  J.  Soa  Chem.  Ind. 

1912,  153;  Nobel  ft  Co.,  Fr.  Pat  432981; 
J.  Soa  ChenL  Ind.  1912,  153 ;  Langenscheidt, 
J.  Soa  Chem.  Ind.  1912,  1147 ;  Blodc,  Zdtsch. 
physikaL  Chem.  1912,  78,  385 ;  Nobel  ft  Co., 
U.  R.  P.  264503;  J.  Soc.  Chem.  Ind.  1913, 
1088;   East,  Z.  ges.  Schiess-  u.  Sprengstoffw. 

1913,  8,  65,  88,  155,  172;  Will,  J.  Soc.  Chem. 
Ind.  1914,  376;  Molinari  and  Giua,  J.  Soa 
Chem.  Ind.  1914,  686;  Giua,  J.  Soc.  Chem. 
Ind.  1914,  687 ;  Koemer  and  Contardi,  AttL 
R.  Accad.  Uncei  1914,  23,  iL  464 ;  Holleman, 
Rea  trav.  chim.  1914,  33,  1 ;  Rintoul,  J.  Soc. 
Chem.  Ind.  1915,  60 ;  OberschlesiBche  A.  G.  f. 
Fabrik.  von  lignose,  D.  R.  P.  277325 :  J.  Soc. 
Chem.  Ind.  1915,  199;  McHutchison  and 
Wright  J.  S(io.  ChenL  Ind  1915,  781 ;  Giua, 
J.  Soc.  Chem.  Ind.  1915,  827,  984 ;  Craig  and 
others,  Eng.  Pat  23181,  1914 ;  J.  Soa  Chem. 
Ind.  1915,  985 ;  Koe^ner  and  Contardi,  J.  Soc. 
Chem.    Ind.    1915,    1046;     Soc.    ItaL    Prod. 


Esplodenti,  Eng.  Pat  19566,  1914;  J.  Soa 
Chem.  Ind.  1915,  1118 ;  Marshall,  Explodves : 
Their  History,Properties,  and  Ifanufacture,  1915. 

For  mode  of  inspeetion  and  testing  of  com- 
mercial trinitrotoluene,  see  Stevens,  J.  Ind. 
Eng.  Chem.  1917,  9,  801 ;  J.  Soc.  Chem.  Ind. 
1917,  36,  1029.  J.  C.  C. 

BENZENEAZOSAUCTUC  ACID  is  obtained 
by  diazotising  a  cooled  mixture  of  aniline  and 
hydrochloric  add  with  sodium  nitrite,  and 
adding  the  diazonium  chloride  ■  to  an  aqueous 
solution  of  sodium  salicylate  when  the  yellow 
sodium  salt  of  the  azo-  compound  is  formed 
(Fischer  and  Schaar-Rosenbeig,  Ber.  1899, 
32,  HI). 

BENZENE  DIAZONIUM  8ALT8  v.    DiAto 

COMPOUNDS. 

BENZENE  SULPHONIC  ACIDS, 

Benzoie  lulphoole  add  {phentd  stdphwaiu 
addf  sul'phabenzolic  acid)  CgH^'SOtH  may  be 
prepared  by  shaking  benzene  with  fuming 
sulphuric  acid,  or  by  passing  benzene  vapour 
into  heated  sulphuric  acid ;  by  oxididng  benzene 
sulphinic  add ;  by  boiling  p-diazobenzena 
sulphonic  add  with  alcohol. 

On  the  large  scale  it  is  made  as  an  inter- 
mediate product  for  the  manufacture  (A  phenol 
by  sulphonating  benzene  in  a  dosed  cast-iron 
steam-jacketed  nan  fitted  with  a  hdioal  stirrer. 
For  details  of  the  various  methods  of  oairving 
out  this  operation,  see  Cain's  Intermeduate 
Products  for  Dyes,  Macmillan  and  Co.,  1918. 
The  free  add  is  best  obtained  by  decomposing 
the  lead  or  barium  salt  with  sulphuric  ad£ 
Forms  small  deliquescent  plates  containing 
1}  mob.  H,0. 

Bemene»m-di9%Mumic  acid  CcH4(80aH)j. 
Obtained  hj  the  further  action  of  sulphuric 
add  upon  benzene,  or  on  the  preceding  com- 
pound, at  a  temperature  of  240''-250''.  At 
nigher  temperatures,  or  under  the  influence  of 
catalysts  (meroury,  ferrous  sulphate),  the  j»- 
isomeride  is  formed  in  additu>n.  Lamberts 
(D.  R.  P.  113784)  employs  as  sulphonating 
agent  sodum  hydrogen  dindpkaU  NaHJSO«)t 
(obtained  b^  heating  acid  sodium  sulphate 
with  sulphunc  add).  This  is  mixed  with  benzene 
and  heated  to  200%  treated  with  milk  of  lime, 
and  the  solution  of  the  sodium  benzene-m- 
diBulphonate  filtered  off  and  evaporated.  The 
free  add  forms  very  ddiquescent  crystals 
containing  2^  mols.  H^O. 

Bemene'tri-sulphonic  acid  C^HJSOgH)^,  pre- 
pared by  heating  an  alkaline  salt  of  the  mono-  or 
m-disulphonic  add  with  sulphuric  acid  until  the 
sulphunc  acid  volatilises. 

BENZIDINE  and  BENZIDINE  BEARRANGB- 

MENT  V.  DiFHBNYL. 

BENZIDINE  AZO-  DTES  v,  Azo-  ooloubino 
MATTBBS,  and  DiSAZO-  and  Tbtbazo-  coloubino 

HATTBBS. 

BENZmiNEDISULPHONIC    ACID    v.    Di- 


BENZIDINE    PUCE    v.     Azo-    coloubimo 

MATTBBS. 

BENZIL  V,  Kbtohbs. 

BENZINE,  Light  petroleum  (v.  Pbtbolbum). 

BENZmOFOBM.    Syn.    for   carbon   tetra 
chloride  {q.v.). 

BENZO-AUBlME,  -BLACK  BLUE,  -BLUE, 
-BROWNS,  -FAST  PINK,  -FAST  SCARLETS, 
-INDIGO  BLUB,  -GBST.  -OLIVE,  -ORANGE, 


580 


BENZOFLAVINE. 


-PURPUHiro,  -RED  BLUE,  -VIOLET  v.  Azo- 

OOLOUBIKO  MATTBBS. 

BENZOFLAVINE  v.  Aobidiki  dybstutfs. 

BENZOIC  ACID  C,H,0,opC,H,CO,H.  (Acide 
henzdlqy^  Ft.;  BemoiMiure,  Qer.}  Acidum 
henzoicum.  Blaise  de  Vigen^re,  in  hu  Traits  du 
fen  et  du  eel,  published  in  1608,  described  the 
preparation  of  oenzoio  acid  by  sublimation  from 
gum  benzoin.  Lemery,  in  1676,  called  attention 
to  its  acid  properties ;  and  Scheele  showed,  in 
1776,  that  it  could  be  extracted  from  gum 
benzoin  by  boiling  the  oum  with  lime,  concen- 
trating the  solution,  and  decomposing  the  salt 
with  hydrochloric  acid.  Scheele  also,  in  1786, 
obtained  benzoic  acid  from  cow's  urine ;  but  it 
was  not  until  1829  that  Uebig  showed  that  the 
substance  contained  in  the  urine,  by  the  decom- 

fosition  of  which  benzoic  acid  is  formed,  is 
ippurio  acid. 
Occurrence, — ^Benzoic  acid  occurs  in  gum 
benzoin,  tolu  balsam,  storaz,  dragon's  blood, 
and  various  other  natural  resins ;  in  oil  of  ber- 
gamot  and  oU  of  cinnamon  ;  in  vanilla,  calamus 
root,  and  the  ripe  fruit  of  the  dove  tree;  in 
various  sweet-smelling  flowers — thus  in  the 
flowers  of  Vnona  odaratissima,  from  which  the 
perfume  vtatig-ylang  is  prepared ;  as  hippuric 
acid  (and  sometimes  even,  it  is  asserted,  as 
free  benzoic  add)  in  the  urine  of  herbiyora ;  and 
in  ecwtoretfm,  a  viscid,  fostid  secretion,  found  in 
pouches  situated  in  the  perinnum  of  the  beaver. 
FomuUion. — ^By  the  oxidation  of  all  com- 
pounds which  contain  the  phenyl  oroup  united 
to  a  single  lateral  chain,  such  as  tohiene,  benzyl 
chloride,  bcnzvl  alcohol,  benzaldehyde,  cinnamic 
acid,  ftc.  ByneatingbenzotrichlorideC.H.'CGl, 
with  water.  By  heating  benzonitrile  CfHg-CN 
with  acids  or  alkalis.  By  boiling  hippuric 
acid  with  hydrochloric  acid 
(C,H,0)NHCH,CO,H-hH,0 

=C,HgOa+NH,CH,CO,H. 

By  passing  carbon  dioxide  into  benzene  con- 
taining aluminium  chloride 

C,H,+CO,=C,H,CO,H. 

Preparation. — 1.  From  gum  benzoin.  In 
order  to  obtain  the  acid  from  gum  benzoSn  bv 
sublimation,  the  gum,  broken  up  into  small 
pieces,  is  introduce  into  a  flat  iron  vessel,  over 
the  mouth  of  which  filter  paper  is  then  pasted.  A 
huge  conical  cap  of  strong  paper,  exactly  fitting 
the  iron  vessel,  is  placed  over  the  filter  paper, 
tied  round  the  rim,  and  the  whole  is  gently 
heated  over  a  sand-bath  at  a  temperature  of 
about  170^  The  benzoic  acid  sublimes  through 
the  filter  paper  and  collects  in  colourless  oryst^ 
inside  the  paper  cone,  from  which  it  is  removed  at 
the  end  of  the  operation  (Mohr,  Annalen,  29, 177). 
The  yield  is  about  4  p.c.  of  the  gum  employed, 
and  from  three  to  four  hours  are  required  for 
tke  sublimation  of  a  pound  of  benzoic  acid.  A 
trace  of  an  aromatic  oil  from  the  gum  adheres 
to  the  crystals,  imparting  to  them  a  pleasant 
odour  of  vanilla,  and  enhancing  their  value  as  a 
pharmaceutical  preparation.  On  a  manuiactur- 
mg  scale  a  modification  of  the  foregoing  labora- 
tory process  is  employed,  in  whioH  the  gum  is  | 
heatea  in  a  dosed  vessel  and  the  vapour  of  the  ' 
sublimine  acid  flows  over  into  a  side  chamber 
and  condenses  at  a  point  bdow  the  source  of 
heat,  thus  obviating  all  risk  of  fusing  the  sub- 
limate. The  gum  benzoin  is  introduced  by 
means  of  a  metal  drawer,  which  is  heated  from 


beneath  by  gas-jets;  whilst  the  sublimed  acid 
collects  in  a  second  drawer,  and  can  thus  be 
removed  at  the  end  of  the  operation  (oomp. 
Starting,  Arch.  Pharm.  231,  342).  By  other 
methods  the  yield  from  gum  benzlon  may  be 
increased  to  26  p.c 

Wdhlor's  method  (Annalen,  49,  246)  consists 
in  dissolvinfl;  the  powdered  gum  in  an  equal 
volume  of  alcohol  of  90-96  p. a,  adding  fuming 
hydrochloric  acid  to  the  hot  solution  until  a 
precipitate  begins  to  be  formed,  and  distilUng  the 
mixture.  The  distillate  contains  ethyl  benzoate, 
alcohol,  and  hydrochloric  acid.  The  residue  is 
again  distilled  with  water  as  Ions  as  ethyl  ben- 
zoate  passes  over,  and  the  united  distillates  are 
boiled  with  caustic  potash  to  decompose  the 
ethyl  benzoate.  From  the  solution  the  benzoic 
acid  is  precipitated  with  hydrochloric  acid.  It 
smeUs  like  the  sublimed  product. 

Schede's  method  of  extracting  the  benzoio 
acid  from  the  gum  with  slaked  lime  and  water 
{v.  supra),  may  also  be  employed. 

2.  From  vrt'ns.  The  urine  of  the  cow  or 
horse  is  allowed  to  putrefy,  so  as  to  induce  a 
hydiolytic  decomposition  of  the  hippuric  acid 
into  benzoic  acid  and  elyoocolL  Milk  of  lime  is 
then  added,  the  filtered  solution  is  evaporated  to 
a  small  buUc,  and  the  benzoic  acid  predpitated 
with  hydrochloric  acid.  In  order  to  avoid  the 
evaporation  and  the  attendant  disagreeabie 
smell,  the  excess  of  lime  may  be  removed  by 
carbon  dioxide,  the  benzoic'acid  precipitated  by 
the  addition  of  ferric  chloride,  and  the  ferric 
benzoate,  after  separating  it  by  filtration,  de- 
composed by  hydrochloric  acid.  The  add  thus 
prepared  smells  of  urine,  and  4nust  not  be  uaed 
m  medicine.  The  smdl  may,  however,  be 
removed  or  concealed  by  mixing  the  acid 
with  a  small  quantity  of  gum  benzoin  and 
subliming;  it. 

The  neah  urine  may  also  be  evajwrated  to 
one-third  of  its  bulk,  filtered,  mixed  with  hydro- 
chloric acid,  and  allowed  to  oooL  Hippuric  acid 
crystallises  out,  which,  by  boiling  with  oonoen- 
trated  hydrochloric  acid,  is  decompoeed  into 

flycocoll  hydrochloride  and  benzoic  acid. 
benzoic  acid  may  also  be  prepared  by  the  action 
of  ammonia  and  zinc-dust  on  gallic  acid  and 
catechu-tannic  acid  (Quignet,  Compt.  rend.  113, 
200). 

3.  From  toluene.  Most  of  the  benzoic  add 
employed  at  the  present  day,  and  certainly  all 
that  is  employed  in  the  coal-tar  colour  industry, 
is  manufactured  from  toluene  {v.  infira).  Toluene 
by  oxidation  with  nitric  acid,  may  be  directly 
converted  into  benzoic  acid ;  but  it  is  better 
to  chlorinate  it  first  to  benzyl  chloride,  which  is 
more  readily  attacked  by  the  oxidisins  agents 
Lunge  and  Petri  (Ber^  10,  1276)  boil  benzyl 
chloride  (1  pari>)  and  dilute  nitric  acid  (3  parts  of 
acid  of  36^Baum^  with  2  parts  of  water)  In 
a  reflux  apparatus  until  the  smdl  of  benzyl 
chloride  ana  benzaldehyde  is  no  longer  pcar- 
ceptible.  A.  v.  Rad  (DingL  poly.  J.  231,  638). 
however.  iit.ates  that  tlus  method  is  onsuited  for 
preparing  the  acid  on  a  manufacturing  scale,  and 
prefers  to  decompose  benzotrichlorideby  heating 
it  with  water  under  pressure : 

C,HjCa,+2H,0=C,H,<X),H-h3Ha ; 

but  it  is  difficult  to  prepare  pure  beniotri- 
chloride,  and  the  benzoic  acid  manufactured  by 
this  process  is  always  contaminated  with  chloro- 


BENZOIC  ACID. 


681 


benzoic  acids  formed  from  ohlorinated  benzo- 
trioblorides. 

EspeoBohied  (D.  B.  P.  47187)  boilB  the 
benzotrichloride  wiUi  milk  of  lime,  or  with  a 
solution  of  caustic  soda  mixed  with  whitinff  or 
other  insoluble  matter,  the  presence  of  which 
aids  the  reaction  by  preventing  the  benzotri- 
chloride from  forming  a  separate  layer  and  also 
by  promoting  local  superheating. 

£.  Jacobsen  (D.  R.  P.  11404  and  13127) 
heats  benzotrichloride  with  acetic  acid  to  which 
a  little  zinc  chloride  has  been  added : 

CcH,*0(31s-h2CHs-COsH=C«H|'GOtH-l-2CHt*GO01-t-HCl 

The  acetyl  chloride  is  distilled  off,  the  residue 
extracted  with  sodium  carbonate,  and  the 
benzoic  acid  precipitated  with  hydrochloric 
aoid. 

P.  Schulze  (D.  R.  PP.  82927,  86493)  heats 
benzotrichloride  with  lime-water  in  the  presence 
of  some  iron  powder.  In  order  to  avoid  the 
formation  of  chloro-derivatives,  the  direct 
oxidation  of  toluene  either  by  nitric  acid  or  by 
manganese  dioxide  and  sulphuric  acid,  has  been 
suggested  {see  D.  R.  PP.  101222,  107722, 
176295,  216091). 

The  Weston  Chem.  Co.  and  J.  Savage  (Eng. 
Pat.  116348)  convert  benzyl  chloride  into  benzyl 
alcohol  b]r  boiling  with  sodium  hydroxide  solu 
tion  or  inilk  of  bme,  and  oxidising  the  alcohol 
to  alkali  benzoate  by  hypochlorite  in  presence 
of  alkali. 

The  benzoic  acid  required  in  the  coal-tar 
colour  industry  is  obtained  as  a  by-product  in  the 
manufacture  of  benzaldehyde  by  bMiting  benzal 
chloride  with  milk  of  lime  {v.  Bbnzaldbhtds), 
a  portion  of  the  benzaldehyde  being  converted 
into  calcium  benzoate  in  this  process. 

4.  From  coal-tar  oiL  Ab&engesellschaft  f  iir 
Theer  und  Erdol  Industrie,  £iur.  Pat.  7867; 
D.  R.  P.  109122 ;  J.  Soc.  Chem.  bid.  1899,  786. 
The  carbolic  or  creosote  oil  fraction,  obtained 
from  coal  tar,  and  boiling  between  160*  and 
240^  contains  benzonitrile.  The  fraction  from 
which  phenol  is  obtained  is  washed  with  dilute 
soda  lye  (sp.gr.  1*1)  to  remove  the  phenol  and 
cresol,  and  the  remaining  oil  placed  in  a  jacketed 
vessel,  provided  with  an  agitator  and  connected 
with  a  condenser  and  receiver.  Caustic  soda 
lye  (s]p.gr.  1*4)  is  added  in  about  twice  the 
quantity  corresponding  to  the  benzonitrile 
present.  The  mixture  is  agitated,  and  wet 
steam  passed  in  for  some  hours,  as  long  as 
ammonia  is  evolved  in  considerable  quantity. 
The  receiver  then  contains  the  lower  boiling 
constituents  of  the  oil,  together  with  a  somewhat 
concentrated  ammonia  solution,  whilst  the 
contents  of  the  stiy  consist  of  a  lower  alkaline 
layer  spd  an  upper  oily  one.  The  former  is 
neutralised  with  carbonic  acid  or  a  nuneral  acid, 
separated  from  traces  of  phenol  or  resinous 
matters,  and  the  reeultine  solution  of  sodium 
benzoate  decomposed  whibt  hot  by  adding  an 
excess  of  acid.  On  cooling,  pure  benzoic  acid 
separates  in  white  crystals. 

6.  From  the  naphthcis  and  other  naphthalene 
derivatives.  Baale  Chemical  Works,  J.  Soc. 
Chem.  Ind.  1901,  1139  j  D.  R  P.  136410 ;  Fr. 
Pat.  313187;  Eng.  Pat.  16627;  U.S.  Pat. 
702171.  (See  also  Chem.  Zentr.  1903,  i.  646,  867, 
1106;  D.  R  PP.  138790,139966, 140999.)  By 
heating  the  naphthols  or  other  naphthalene 
derivatives  to  about  260*,  in  presence  of  alkali 


with  metallic  oxides  or  peroxides  stoh  as  copper 
or  iron  oxide,  barium,  lead  or  manganese  per- 
oxide, they  yield  phthalio  and  benzoic  acids,  and 
a  few  intermediate  products.  The  excess  of 
alkali  is  removed  by  lixiviation  with  a  little 
water ;  the  acids  are  then  dissolved  in  water  and 
decanted  from  the  reduced  oxide.  This  solution 
is  saturated  with  carbon  dioxide  and  filtered 
from  unchanged  naphthoL  The  filtrate  ia 
decomposed  with  suJphurio  acid  and  evapo* 
rated,  the  precipitated  acids  being  purified  oy 
distillation. 

6.  By  the  eUctrdytie  oxidation  of  phenanthrene. 
Farbwerke  vorm.  Meister,  Lucius  and  Brflning, 
Chem.  Zentr.  1904,  iL  71 ;  D.  R  P.  162063. 

Properties. — It  crsrstallises  in  lustrous  leaflets 
or  flat  needles  of  sp.gr.  1*2669  16V4*,  melting  at 
121*4*.  It  boilB  at  249*,  but  is  volatUe  even  at 
100*,  so  that  it  may  readily  be  sublimed ;  the 
vapour  excites  coughing.  It  may  be  distilled 
with  steam ;  2  litres  of  aqueous  distillate  con- 
tain 1  gram  of  benzoic  acid.  100  parts  of  water 
dissolve  at 


4'6° 
1-823 


10° 
2068 


81° 
4*247 


75° 
21*931 


(Ullmann,  Enzyklop.  ii) ;  it  is  soluble  in  about 
twice  its  weight  of  ether  and  in  about  its  own 
weight  of  ab(M)lute  alcohel  at  ordinary  tempera- 
tures. 

Traces  of  impurity  lower  the  melting-point 
of  benzoic  aoid  very  considerably.  The  impure 
acid  is  also  deposited  from  its  solutions  in 
smaller  crystals  than  the  pure. 

(For  absorption  spectra,  see  Hartley  and 
Headley,  Chem.  Soa  Trans.  1907,  319.) 

Reactions. — When  heated  with  lime,  benzoic 
acid  yields  benzene  and  calcium  carbonate 
(Mitscherlich).  It  is  very  stable  towards  oxi- 
dising agents;  dilute  chromic  acid  is  without 
action  on  it,  but  by  wanning  it  with  manganese 
dioxide  and  svlphwric  acid  it  is  converted  in1bo 
formic  acid,  carbon  dioxide,  and  phthalic  acid — 
the  latter  being  formed  by  the  simultaneous 
oxidation  of  forndo  and  benizoio  adds  (Carius, 
Annalen,  148,  72).  Sodium  amaigam  reduces 
benzoic  acid  in  boiling  alcoholic  solution  to 
benzyl  alcohol,  benzaldehyde,  and  tetrahydro- 
benzoic  acid  (Aschan,  Ber.  24, 1864,  and  Anxiaien, 
271,  231).  By  electrolytic  reduction,  benzalde- 
hyde is  obtained  (Mettler,  Ber.  41, 4148),  and  by 
reduction  with  hydrogen  and  platinum,  hexa- 
hydrobenzoic  acid  is  the  chief  product  (WiU- 
statter  and  Mayer,  Ber.  41,  1479).  When  dis- 
tilled over  heated  zinc-duei  it  yields  benzalde- 
hyde (Baeyer,  Annalen,  140,  296).  Calcium 
benzoate  yields  on  distillation  benzophenone 
CfHi'CO'C^H,,  together  with  a  small  quantity  of 
benzene  and  anthraquinone  Q^fifi*  (Kekul^ 
and  Franchimont,  Ber.  6,  908).  Taken  inter- 
naUy,  benzoic  acid  is  excreted  in  the  urine  as 
hippuric  acid  (Wohler). 

When  a  solution  of  ferric  chloride  which 
has  been  mixed  with  sufficient  ammonia  to  turn 
it  dark-red  is  added  to  a  solution  of  a  benzoate, 
a  flesh-coloured  precipitate  of  basic  ferric  ben- 
zoate (C,Hs02),Fe,Fe(0H),  is  formed.  This  re- 
action is  used  in  the  separation  of  benzoic  acid, 
and  also  in  separating  iron  from  manganese. 

Uses. — Benzoic  acid  is  used  in  medicine ; 
but  for  this  purpose  only  the  natural  product, 
obtained  from  gum  bedoln  by  sublimation,  is 
suitable.    AdultQr^^^ou  ^^^  ^  artificial  aoid 


582 


BENZOIC  ACm. 


is  detected  by  heating  a  portion  of  the  acid  on 
platinum  wire  and  holding  a  porcelain  dish 
moistened  with  pbloroglaoolvanillin  over  the 
flame;  the  prodnotion  of  a  red  oolotur,  due  to 
the  presence  of  hydrochloric  acid,  indicaten  the 
presence  of  the  artificial  acid.  Artificial  benzoic 
acid  is  employed  in  the  manufacture  of  anilme 
blue.  It  has  been  used  as  a  mordant  in  calico- 
printing.  Benzoic  acid,  dissolved  in  a  mixture 
of  1  part  of  ether  and  20  parts  of  alcohol,  has 
been  recommended  for  the  preservation  of 
anatomical  preparations.  It  is  said  to  be  used 
in  giving  an  aroma  to  tobacco. 

As  an  antiseptic  it  is  mjuiious  to  health, 
producing  serious  disturbance  of  the  metabolic 
functions,  attended  with  injunr  to  the  digestion 
(Wiley,  U.S.  Dept.  of  Agric,  «f.  Soc.  Chem.  Ind. 
1908,  9U). 

For  its  use  as  an  acidimetric  standard,  see 
Morey,  J.  Amer.  Chem.  Soc.  1912,  34,  1027; 
Analyst,  1912,  458. 

Detection  in  fobdstuffs. — By  the  production 
of  diaminobenzoic  acid  (Mohler,  Bull.  Soc.  chim. 
3,  414) ;  b^  the  action  of  the  acid  on  roeaniline 
hydrochloride  dissolved  in  aniline  oil,  when 
aniline  blue  is  formed  (De  Brevans,  J.  Pharm. 
Chim.  14,  438) ;  by  converting  the  acid  into 
salicylic  acid  with  hydrogen  peroxide,  and  then 
adding  ferric  chloride  ( Jonescu,  J.  Pharm.  Chim. 
29,  623).  In  butter:  By  the  formation  of 
ammonium  diaminobenzoate,  which  gives  a 
brownish-red  colouration  in  alkaline  solution 
(Halphen,  Pharm.  J.  28,  201;  Robin,  Ann. 
Chim.  anal.  14,  53).  In  fermented  beverages 
and  milk  i  As  in  butter  (Robin,  Ann.  Chun, 
anal.  14, 53  ;  Breustedt,  Arch.  Pharm.  237, 170). 
In  meats  and  fats  (Fischer  and  Gruenert,  J. 
Soa  Chem.  Ind.  28,  849). 

Examination  of  the  commercitU  product. — 
The  artificial  benzoic  acid  of  commerce  is  almost 
always  contaminated  with  chlorobenzoic  acids 
(i;.  suvra),  the  presence  of  which  in  any  con- 
sideraole  quantity  is  stated  to  be  detrimental  in 
the  aniline  blue  manufacture.  The  chlorine 
may  be  detected  by  heating  the  acid  with 
metallic  sodium,  extracting  the  residue  with 
water  and  testing  the  solution  with  silver 
nitrate.  The  acid  should  have  the  proper 
melting-point,  and  should  dissolve  without 
residue  in  boiling  water. 

Salts  and  eturs  of  benxole  adds.  Benzoic 
acid  is  monobasic.  Most  of  the  benzoates  are 
soluble  both  in  water  and  in  alcohol.  Potassium 
bemoaie  C7H(OsK,3H,0  :  efflorescent  lamime. 
Sodium  benzoate  C7H.0tNa,H,0 :  efflorescent 
needles,  used  for  inhalation  in  tuberculosis. 
Ammonium  benzoate  C7H,0|(NH4),  rhombic 
crystals,  also  used  in  medicine.  Calcium  ben- 
zoate (C7H,Ot)|C!a,3HaO,  lustrous  needles,  used 
in  the  preparation  of  benzophenone.  Other 
hydrates  are  known.  Forms  an  unstable 
dialcoholate.    Basic  ferric  benzoate 

(C7H,0.),Fe,Fe(0H), 

(v.  supra).  Mercuric  benzoate  small  white 
odourless  tasteless  crystals;  powerful  antiseptic; 
successfully  employed  in  syphilitic  and  similar 
diseases  (MeroTs  Bull.  1890,  [5]  33 ;  [6]  49 ; 
[7]  73). 

The  esters  of  benzoic  acid  are  obtained  either 
by  distilling  benzoic  acid  with  the  alcohol  and 
sulphuric  acid,  or,  better,  by  saturatinfl  a  solu- 
tion of  benzoic  add  in  the  alcohol  witn  hydro- 


gen chloride,  digesting  the  mixture  on  the  water- 
oath  for  some  hours,  precipitating  the  ester 
with  water,  and  purifying  by  distfllation. 
Methyl  benzoate  C-fifi^'CH^  is  a  liquid  bcnliog 
at  198*6''  (Perkin,  Chem.  Soc.  Trans.  69,  1026). 
Ethyl  benzoate  C^Ufl^-CJElt,  boils  at  211 -S"* 
(Perkin,  {.c).  Propyl  benzoate  C7H.0,*C,H„ 
boils  at  230-7''  (Perkin,  I.e.). 

Benzyl  benzoate.  This  ester  forms  the 
therapeutically  active  portion  of  Pern  balsam, 
and  also  the  larger  nraction  of  the  prodoot 
formerly  known  by  the  name  of  cinnam^in,  and 
generally  described  as  consisting  chiefly  or 
entirely  of  benzyl  dnnamate.  Benzyl  benzoate 
is  a  colourless  oil,  boiling  at  173^  under  9  mm. 
pressure,  whilst  the  benzyl  cinnamate  is  crys- 
talline, melting  at  37'',  and  boiling  at  213''- 
214°  under  9  mm.  pressure.  It  is  stated  that 
benzyl  benzoate  is  as  efficacious,  therapeutically, 
as  the  ester  obtained  direct  from  Peru  balsam, 
whilst  it  has  the  advantages  that  it  is  free  from 
colour  and  smell,  is  constant  in  compodtion, 
and  does  not  cause  the  irritation  sometimes 
occadoned  by  Peru  balsam  owing  to  the  free 
acids  present  (E.  iflrdmann,  Pharm  J.  66,  387). 

Siihstitution  Derivatives  of  Benzoic  Acid. — 
o-Chhrobenzoic  add  a-C^H.-COOH  mdts  at 
140",  and  is  obtained  by  the  oxidation  of  o- 
chlorotoluene.  The  chlorine  atom  in  this  acid 
is  very  easily  replaceable  (UUmann,  Annalen, 
1907,  355,  312).  The  macid  melts  at  160°, 
the  p-  acid  at  243°.  Nitration  of  benzoic  acid 
yidos  mainly  the  m-acid,  the  rdative  propor- 
tions of  the  0-,  m-,  and  p-adds  formed  at 
different  temperatures  being  shown  in  the 
subjoined  table  (HoUeman,  Zdtsch.  physikal. 
Chem.  31,  79) : 

o.  m.  p. 

-30°        .         .     14-4        850        0-6 
0°        .         .     18-5        80-2         1-3 
-f30°       .         .     22-3        76-5        12 
The  o-add,  melting  at  144°,  is  prepared  by 
oxidising   o-nitrotoluene   with   potassium  per- 
manganate,  or  with  manganese  dioxide  and 
sulphuric  acid  (D.  R.  P.  179689).    The  m-add, 
by  the  action  of  sodium  nitrate  and  sulphurio 
acid  on  benzoic  add,  or  by  oxidising  m-nitro- 
benzaldehyde  with  sodium  hypochloride  (Ba- 
dische,  AnilLn  u.  Soda  Fabrik,  D.  R.  P.  211950). 
It  mdts  at  140°-141°.    The  p-acid,  mdtin^  at 
238°,  is  obtained  by  the  oxidation  of  p-mtro- 
toluene  with  chromic  and  sulphuric  adds. 

Sulphcbenzoic  acids.    The  o-add 

HOOC-C,H4SO,H,3H,0 
is  obtained  by  the  oxidation  of  toluene-o-sul- 

Shonic  acid*  or  of  thioealicylic  add,  or  bv 
iazotising  anthnmilic  acid  and  adding  sul- 
phurous acid.  It  melts  at  68°-69°,  and  in  the 
anhydrous  condition  at  134°.  Direct  sulphona- 
tion  of  benzoic  acid  yields  chiefly  the  m-add 

BENZOIC  ANHYDRIDE  (C,H.<X)),0.  First 
prepared  by  Gerhardt  (Ann.  Chim.  Phys.  [3]  37, 
z99)  by  the  action  of  benzoyl  chloride  on  sodium 
benzoate  or  on  sodium  oxalate,  or  of  phosphoras 
oxychloride  on  sodium  benzoate : 

CjP.C0,Na+C,H,O0a=(C,H.-C0),0+NaCl; 
2C^,(X)Cl+Na,C,04 

=(CjH,(X)),0-h2NaCl-hOO-hOO, ; 
4C,H,<X),Na+P0Cl, 

-2(CgH,<X)),0-fNaPOa+3Naa 

Preparation. — ^Pour  100  grams  of  phosphorus 

oxychloride  over  600  grams  of  dry  sodium  ben- 


BENZOYL  SULPHONIC  IMIDE, 


083 


Eoate  contained  in  a  flask;  complete  the  re- 
action b^  heating  at  150^  ;  remove  sodium  salts 
by  washmg  the  cooled  mass  with  dilute  sodium 
oarbonate,  and  purify  the  anhydride  by  dis- 
tillation. 

Ansohiitz  (Annalen,  226,  15)  heats  benzoyl 
chloride  with  anhydrous  oxalic  acid.  This 
avoids  the  formation  of  metallic  salts  altogether. 

It  may  also  be  prepared  by  heating  Iwnzoyl 
chloride  with  fused  and  powdered  sodium  nitrite 
for  12  hours;  the  product  is  extracted  with 
ether  and  freed  from  traces  of  benzoic 'acid  by 
rapidly  washing  with  a  very  dilute  solution  of 
sodium  carbonate,  and  finiedly  with  distilled 
water;  yield  70  p.c.  (Minunni  and  Caberti, 
Gazz.  chun.  itaL  20,  665).  By  mixing  together 
benzoyl  chloride  and  pyridine  and  adcuuff  water 
after  half  an  hour,  pure  benzoic  anhydride  is 
precipitated;  yield  80  p.c.  (Minunni,  Gazz. 
ohim.  ital.  22,  ii.  213).  By  treating  benzoyl 
chloride  with  sodium  carbonate  and  pyridine ; 
yield  quantitative  (Deninger,  J.  pr.  Ohem. 
60,  ii.  470).  By  treating  benzoyl  chloride  with 
sodium  hyposu^>hite  in  the  presence  or  absence 
of  pyridine  (Binz  and  Marx,  Ber.  40,  3855) ;  by 
treating  benzenesulphonic  chloride  with  sodium 
benzoate  (Chem.  Fab.  von  Heyden,  D.  R.  P. 
123052;  Chem.  Zentr.  ig!P2,  2,  518);  by 
treating  benzoic  acid  or  sodium  benzoate  witn 
methylchlorsulphate  (Bad.  Anil,  und  Sod. 
FabiJk,  D.  R.  P.  146690 ;  Chem.  Zentr.  1904, 
i  65) ;  by  treating  benzoic  acid  with  acetic 
anhydride  in  the  presence  of  an  indifferent 
solvent  such  as  benzene  or  xylene  (Kaufmann 
and  Luterbaoher,  Ber.  42,  3483) ;  from  benzo- 
trichloride  and  acetic  acid  (B€hal,  Compt.  rend. 
148,  648);  by  the  action  of  concentrated 
sulphuric  acid  on  benzotrichloride ;  and  by  the 
action  of  sulphuryl  chloride  on  a  mixture  of 
sodium  and  calcium  benzoates  (D.  R.  P.  161882). 

Propertied. — ^Rhombic  prisms,  sp.gr.  1*1989 
1674*',  melting  at  42^  and  boiling  at  360°  (corr.) 
(Lnnuiden,  Chem.  Soc.  Trans.  1905, 93).  Insoluble 
in  water ;  readily  soluble  in  alcohol  and  ether. 

Beactions. — ^Water  decomposes  it  very  slowly 
in  the  cold,  more  rapidly  on  boiling,  with  forma- 
tion of  benzoic  add.  Towards  ammonia,  amino- 
and  imino-  compounds,  alcohols  and  phenols,  it 
behaves  like  benzoyl  chloride,  replacing  bv  a 
benzoyl-  group  a  hydrogen  atom  attached  to 
nitrogen  or  oxygen.  For  this  reason  it  'a,  like 
benzoyl  chloride  {q»v,),  used  as  a  reagent  for 
amino-,  imino,  and  hydroxyl-  groups,  and  it  has 
the  advantage  over  the  latter  leaeent  that  no 
hydrochloric  acid,  a  substance  which  has  a  very 
prejudicial  effect  on  many  organic  compounds, 
IS  liberated  during  its  action. 

BENZOte  GUM  V.  Balsams. 

BENZOfil  YELLOW.  This  compound  is 
obtained  by  condensing  benzoin  with  sallio  acid. 
Benzoin  is  added  to  a  solution  of  gallic  acid  in 
sulphuric  acid,  kept  at  a  temperature  of  0^-5°, 
ana,  after  being  stirred  during  24  hours,  the 
mixture  is  poured  into  water,  the  dye  beins 
precipitated.  It  crystallises  from  a  mixture  m 
acetic  acid  and  alcohol  in  yellow  needles.  Its 
constitution  is  given  as 

CH^-C C'Ph 

^X>^fi{On)^^  to  :  (OH), :  C0=  1 : 2  :  3  : 4] 
(Bad.  Anil.  Sod.  Fab.  D.  R.  P.  96739 ;  Chem. 


Zentr.  1898,  L  870,  and  Graebe,  Ber.  31,  2975) 

(V,  AUZARiy  AND  ALU  ED  GOLOUBINO  MATTISRS). 

BENZONAFHTHOL,  j3-NAPHTH0L  BENZO- 
ATE V.  Synthbtig  Drugs. 

BENZOPHENONE  {Diphenyl  Ketone)  (v. 
Ketones). 

BENZO-QUINONE.    See  Quinone. 

BEHZOSALIN.  l>ade  name  for  benzoyl- 
salicylic-acid-methyl  ester,  used  in  the  treatment 
of  aiticular  and  muscular  rheumatism,  neuritis, 
neun^ia,  and  sciatica.     V.  Synthetic  dbugs. 

BraZOSOL  6UIAC0L  BENZOATE  v.  Syn- 

THETIG  DRUGS. 

BENZOTRICHLORIDE  V.  Toluene,  Chlor- 
ine DERIVATIVES  OF. 

BENZOYL  CHLORIDE  C.H.COa.  First 
obtained  by  Liebig  and  Wohler,  by  passing 
chlorine  into  benzaldehyde  (Annalen,  3,  262). 
By  the  action  of  phosphorus  pentachloride  on 
benzoic  acid  (Cahours,  Aim.'Chmi.  Phys.  [3]  23, 
334). 

Preparation. — Benzoic  acid  is  heated  with 
slightlv  more  than  the  molecular  proportion  of 
phosphorus  pentachloride 

C,H,C00H+PCl,=C,H,C0a+P0a,4-HCl 

The  resulting  benzoyl  chloride  is  freed  from  the 
phosphorus  oxychloride  by  fractional  distillation. 
Commercial  l>enzoyl  chloride  is  usually  con- 
taminated with  chlorbenzoylchloride  and  fre- 
quently with  small  quantities  of  benzaldehyde 
(V.  Meyer,  Ber.  24,  4251,  and  25,  209). 

From  oxalyl  chloride,  benzene,  and  alu- 
minium chloride  (Staudinger,  Ber.  1908,  3566). 
From  benzoic  acid  or  sodium  benzoate  and 
methylchlorosulphate  (Bad.  Anil,  und  Sod. 
Fabrik,  D.  R.  P.  146690;  Chem.  Zentr.  1904, 
i.  65). 

From  salts  of  benzoic  acid.  By  treatment 
with  sulphur  dioxide  and  chlorine  (Farb.  vorm. 
Meister,  Lucius  and  Briining,  D.  R.  P.  210806 ; 
Clhem.  Zentr.  1909, 279) ;  or  with  sodium  chloro- 
sulphonate  (D.  R.  P.  146690) ;  or  b$r  the  action 
of  sulphuryl  chloride  on  benzoic  aci<£ 

Properties. — Colourless  liquid,  with  a  pungent 
odour,  boiling  at  199^  (Lumsden,  Chem.  Soc. 
Trans.  1905,  94) ;  197  2''  (corr.)  (Perkin,  Chem. 
Soc.  Trans.  69,  1244).  Its  vapour  attacks  the 
eyes,  causing  a  flow  of  tears.  Sp.gr.  1*2122 
2074°  (BruhJ,  Annalen,  235,  11). 

Reactiona. — Benzoyl  chloride  reacts  with 
tiNz/er,  slowly  in  the  cold,  rapidly  on  heating, 
with  formation  of  benzoic  and  hydrochloric  acids. 
With  ammonia  it  forms  benzamide 

C,H,C0NH, 

together  with  ammonium  chloride.  In  like 
manner  it  reacts  with  compounds  containing 
hydroxvl-,  amino-,  or  imino-  groups,  introducing 
benzoyl  in  place  of  hydrogen,  and  is  therefore 
employed  in  organic  chemistry  as  a  test  for  the 
presence  of  these  groups  in  a  compound.  Thus 
with  dkohot  it  yields  ethyl  benzoate ;  with 
aniline,  benzanilide  and  dibenzanilide. 

BENZOYL  BCGONINE  v.  Cogainb  and  the 

Cog  A   ALALOID3. 

BENZOYL  FORMIC  ACID  v.  Ketones. 
BENZOYL  GLYCOCOLL  v.  Hifpurig  acid. 
BENZOYL  PINK  v.  Azo-  golouring  matters. 
BENZOYL  SULPHONIC  Q&IDE  and  BEN- 
ZOIC  SULPHIDE  V.  Saccuarxn. 


684 


BENZYLAMINE  GARBOXYLIC  AOIDS. 


BENZYLAMINE   CARBOXYUO   ACIDS   v. 

Amino-  acids  (aromatio). 

BENZYL  BLUE.  A  dye  made  by  the 
Aktieiigesellsohaft  fur  Anilmfabrikaiion,  Berlin, 
by  sarotituting  three  atoms  of  hydrogen  in 
rosaniline  by  three  benzyl-  groups.  It  is  easily 
soluble  in  water ;  dyes  silks,  wools,  and  cotton 
(Reimann's  Farber-Zoit.  1879,  251 ;  Industrie- 
Blatter,  39,  360). 

BENZYL  CHLORIDE  v.  Toluene,  Ohlob- 

XNE  DEBIVATIYBS  OF. 

BENZYLDIPHENYLAMINE   v.    Diphenyl- 

AMINE. 

BENZYLHORPHINE  v.  Opium. 
BENZYLPHENYLHYDRAZONES  v.  Htdba. 

ZONES. 

BERBERINE  AND  THE  BERBERIS  ALKA- 
LOIDS. Berberine  C,oHi,OgN  is  contained  in 
various  species  of  Berberie,  especially  B.  vulgaris 
(Linn.)  (the  barberry),  which  also  contains 
berbamine  G|,H|,OaN  (Hesse,  Ber.  1886,  19, 
3193),  and  ozyacanthine  {v.  infra),  in  Hydrastis 
canadensis  (Linn.),  together  with  hydrastine  and 
canadine  in  Coptis  Teela  (Wall.),  which  con- 
tains as  much  as  8  p.c.,  and  in  many  other 
plants,  but  not  in  calumba  root  (Gordin,  Arch. 
Pharm.  1902,  240,  146). 

Preparation. — ^The  best  available  material 
from  which  to  extract  berberine  is  the  root  of 
Hydrastis  canadensis  (Linn.)  (*Qolden  Seal'), 
which  contains  about  4  p.c.  of  the  alkaloid. 
The  finely-powdered  hydrastis  root  is  exhausted 
with  alcohol,  tiie  greater  part  of  the  alcohol 
removed  by  distillation,  and  the  alkaloid  con- 
verted into  sulphate  or  nitrate  by  the  addition 
of  sufficient  dilute  sulphuric  acid  or  nitric  acid. 
The  crude  berberine  salt  which  separates  is 
collect,  dissolved  in  water,  and  mixed  with 
acetone  and  sodium  hydroxide,  when  the 
crystalline  condensation  product,  aSihydrober- 
berineacetone,  separates  (Gaze,  Zeit.  Naturwiss. 
Halle,  1890,  62,  399).  After  recrystallisation, 
this  product  melts  at  175®  (corr.)  (Pyman,  Chem: 
Soc.  Trans.  1911,  99,  1690) ;  it  yields  with  hot 
dilute  mineral  acids  the  corresponding  berberi- 
nium  salts.  The  free  base  exists  in  two  isomeric 
forms,  represented  by  the  partial  formula 
below: 

CH  CH 

C  lie 


IL 

as  the  quaternary  ammonium  hydroxide, 
berberinium  hydroxide  (I.),  which  is  known 
only  in  aqueous  solution,  and  as  the  carbinol- 
amine,  berberine  (II.),  adso  termed  berberinal 
and  berberinol.  For  the  nomenclature  of 
berberine  and  its  salts,  see  Perkin  (Chem.  Soo. 
Trans.  1918,  113,  603).  A  solution  of  berberi- 
nium hydroxide  is  prepared  by  adding  the 
equivalent  quantity  of  barium  hydroxide  to 
an  aqueous  solution  of  berberinium  sulphate, 
whilst  the  addition  of  an  excess  of  sodium 
hydroxide  to  this  solution  afifords  a  precipitate 
of  the  carbinolamine,  berberine,  which  is 
extracted  by  ether,  and  crystallises  on  con- 
centrating the  solution  (Gadamer,  Arch.  Pharm. 
1905,  243,  31). 


Properties, — Berberine  GmHi^OsN  crystal- 
lises from  ether  in  yellow  needles,  which  melt 
at  144°,  and  are  anhydrous.  It  is  insoluble  in 
oold  water,  but  on  warming  gradually  yields 
a  solution  of  berberinium  hy(uoxide.  It  dis- 
solves in  acids,  giving  salts  of  berberiniom 
hydroxide.  The  berbennium  salts  CioHigO^NX 
(where  X  is  a  monobasic  add  radical)  crystallise 
well,  and  are  of  a  yellow  or  red  colour.  They 
are  sparingly  soluble  in  water,  especially  in  thue 
presence  of  mineral  acids  or  salts.  Their 
aqueous  solutions  are  neutral  to  litmus,  optically 
inactive,  and  have  a  bitter  taste.  Berberine  is 
not  poisonous  to  man,  and  is  used  medicinally, 
like  preparations  of  the  plants  containing  it,  as 
a  tonic. 

Detection  and  Estimation. — Chlorine  water 
gives  with  a  solution  of  the  hydroxide  a  bright- 
red  colouration  even  in  very  dilute  solutions. 
For  the  detection  of  berberine  in  plants,  see 
Gordin,  Aroh.  Pharm.  1902,  240,  146.  The 
same  author  recommends  for  its  estimation  the 
precipitation  of  the  alkaloid  as  sulphate  from 
its  alcoholic  solution,  the  decomposition  of  the 
sulphate  by  potassium  iodide  and  the  titration 
of  the  sulphuric  acid  liberated  by  means  of 
i^/40  potassium  hydroxide  {ibid.  1901,  239,  638). 

Constitution. — ^^he  main  features  of  the 
constitution  of  berberine  were  determined  by 
Perkin  (Chem.  Soc.  Trans.  1889,  55,  63 ;  1890, 
57,  992)  by  a  study  of  its  oxidation  products, 
and  subsequent  work  by  Gadamer  (Chem.  2ieit. 
1902,  26,  291,  385;  Arch.  Pharm.  1905,  243, 
31 ;  1910, 248, 43),  Perkin  and  Robinson  (Chem. 
Soc.  Trans.  1910,  97,  321),  and  Tinkler  {ibid. 
1911,  99,  1340),  established  the  formula  given 
below,  which  has  since  been  confirmed  through 
the  synthesis  of  the  alkaloid  by  Pictet  and  Gams 
(Ber.  1911,44,2480). 

0— P^« 


MeO 


mo 


CH 


MeO  CHOH  CH, 


Attention  may  be  drawn  to  the  similarity 
between  the  formula  of  berberine  and  that  of 
hydrastine  which  occurs  with  it  in  Hydrastis 
canadensis  (Linn.). 

Oxyeanthine  Ci»H,|0,N  accompanies  ber- 
berine in  Berberis  vulgaris  (Linn.)  (Folex,  Aroh. 
Pharm.  1836,  [ii.]  6,  271 ;  Hesse,  Ber.  1886, 
19,  3190;  Budel,  Arch.  Pharm.  1891,  229, 
631),  and  may  be  isolated  from  the  mother-Uqaor 
from  which  all  the  berberine  salt  has  crystallised 
by  precipitation  with  sodium  carbonate.  It 
crystallises  with  difficulty  from  alcohol  or  ether, 
m.p.  208''-214''  (Hesse),  is  insoluble  in  water, 
easily  soluble  in  chloroform,  less  so  in  alcohol. 
The  alcoholic  solution  is  dextrorotatory,  and 
has  a  bitter  taste.     It  yields  crystalline  salts 

F.  L.  P. 

BERENOELTTE,  A  bituminous  reainoiis 
mineral  from  San  Juan  de  Berengela,  melting 
at  100°,  soluble  in  alcohol  and  ether.  According 
to  Dietrich,  specimens  from  Trinidad  and  Arica, 
Chile,  contained  71*84  C,  9*95  H,  and  18*21  of  O 
(Chem.  Zentr.  80, 559).    Used  for  oauUdng  ships. 

BER6AM0T  v.  Oils,  Essbntial. 


BETAINE. 


586 


BERGMANN'S  POWDER.  An  exploaive 
composed  of  60  parts  potassiom  chlorate,  6  of 
pyrolusite,  and  46  of  bran,  sawdust,  or  tan  (J. 
37.  1748). 

BERLIN  BLACK.  A  black  varnish  drying 
with  a  dead  surface,  used  for  coating  ironwork. 

BERLIN   BLUE   or   PRUSSIAN    BLUE   v. 

OVAiaDES. 

BERNTHSEN'S  VIOLET.  Iwthionine.  p- 
AmidothiodiphenifUmide.  Formed  by  reduc- 
ing ^-dinitrodiphenylaminesulphoxide  and  oxi- 
dising the  leuco-  base  with  ferric  chloride.  The 
hydrochloride  crystallises  in  needles.  Dyes 
reddish-violet.  Isomeric  with  LatUh's  violet 
(Bemthsoi,  Annalen,  230,  133). 

BERRY  WAX  v.  Waxes. 

BERTHIERINE  v.  Thubingitb. 

BERTHIERITE.  Iron  sulphaTUimoniie  {v. 
Antimony). 

BERYL.  A  mineral  consisting  of  glucinum 
aluminium  silicate  61sAl,Si«0i8,  crystallising 
in  the  hezasonal  S3r8tem.  The  ancient  name, 
fiiipvWos,  included  also  some  other  gem-stones 
of  a  greenish  colour.  Th#  crystals  are  usually 
quite  simple  in  form,  with  only  the  hexagonal 
prism  and  the  basal  plane;  the  habit  Deins 
commonly  prismatic  and  the  prism  faces  striated 
vertically.  They  are  usually  cloudy  or  opaque, 
with  a  pale-greenish  or  yellowish  colour  and  are 
often  of  considerable  size,  crystals  weighing  as 
much  as  one  or  two  tons  having  been  found  at 
Acworth  in  New  Hampshire.  The  sp.gr.  is 
2*63-2-80,  and  the  hardness  7^8.  The  material 
is  not  attacked  by  acids,  except  hydrofluoric ; 
and  before  the  blowpipe  is  fusible  only  with 
difficulty  on  the  edges. 

Crystals  of  a  difrerent  type  are  found  in  asso- 
ciation with  lithia  minerals  (lepidolite  and  rubel- 
lite)  in  pegmatites  in  the  Urtds,  Califomia,  and 
Madagascar.  These  are  tabular  in  habit  and 
roae-ied  or  colourless.  Further,  they  differ 
chemically  in  containing  small  amounts  of 
alkalis  (Cs,0  3*1,  Li,0  1*4  p.c).  V.  Vemadsky 
(1908)  expresses  the  composition  by  the  for- 
mula TsGudfiifiiyyA,  where  A  is  GlH,Si04, 
GlSiO,(7),  Cs^iO„  Li^iO,,  or  Na,SiO, ;  and 
for  the  CKsium-bearing  variety  he  proposes  the 
name  vorebyevite. 

Being  by  far  the  most  abundant  of  glucinum 
minerals,  beryl  is  employed  for  the  preparation 
of  the  little-used  salts  of  glucinum.  It  finds 
more  extensive  application  in  jewellery.  The 
clear  grass-green  variety  is  the  emarald,  one  of 
the  most  valuable  of  gems  on  account  of  the 
rarity  of  flawless  material.  Gem-stones  of  a 
greenish,  bluish,  or  sea-green  colour  are  known 
as  aquamarine.  Pink  beryl  of  gem  quality  has 
been  called  morganite,  and  a  g^den  ocryl  from 
South- West  Africa  is  p[iven  the  name  heUodor. 
For  a  fuller  description  of  material  of  gem 
quality  and  its  occurrences,  «ee  M.  Bauer, 
Precious  Stones,  transl.  by  L.  J.  Spencer, 
London,  1904.  On  the  gem  beryls  from 
Madagascar,  see  A.  Lacroix,  Mineialogie  de 
la  Fiance,  1910,  1913.  L.  J.  S. 

BERYLLIUM  v,  Glucinum. 

BERZEUANITE.  Native  copper  selenide 
Cn^Se,  occurring  in  a  black  powdery  form  in 
calcite  at  Skrikerum  in  Sweden  and  at  Lehrbach 
in  the  Haiz.  Named  after  the  Swedish  chemist 
J.  J.  Berzelius  (1779-1848),  who  first  analysed  it. 

La     J.     S. 


BERZEUTE.  Arsenate  of  calcium,  manga- 
nese, and  magnesium  (Ca,Mn,Mg),As,0,,  occur- 
ring as  small  yellow  cubic  crystals,  and  as  com- 
pact maMew,  with  ores  of  iron  and  manganese 
at  Lngban  in  Wermland,  Sweden.  Also 
named  after  J.  J.  Beizelius.  Other  forms  of  the 
same  name,  berzeline  and  berzelite,  have  been 
applied  to  these,  as  well  as  to  some  other  minerals. 

BESSEMER  STEEL  v.  Ibon. 

BETAFITE.  The  betafite  group  of  minerals, 
recognised  by  A.  Lacroix  in  1912  in  the  pegma- 
tites of  Mad^ascar,  includes  betafite,  samiresite, 
and  blomstrandite  (of  G.  Lindstrom,  1874). 
They  are  titano-columbates  (and  tantalates)  of 
uranium,  &o.,  crystallising  in  the  cubic  system, 
and  closely  allied  to  pyrochlore  and  hatchettolite. 
From  the  former  they  differ  in  containing  only 
little  lime  and  rare-earths  and  an  absence  of 
alkalis  and  fluorine;  and  from  the  latter  in 
containing  titanium.  Betafite  is  a  hydrated 
titano-colnmbate  of  uranium  (UO,  26-28  p.c.). 
Sharply  developed  octahedral  crystals  with  the 
edges  truncated  by  faces  of  the  rhombic- 
dodecahedron  have  been  found  in  considerable 
numbers  at  Ambolotara  near  Betafo,  and  other 
localities  in  Madasascar.  They  reach  an  inch 
in  diameter,  and  uiow  a  dull  yellow  weathered 
surface,  but  in  the  interior  the  material  is 
brownish-black  with  a  bright  greasy  lustre. 
Sp.gr.  3*69-4*476  depending  on  the  degree  of 
hycuation.  Samiresite,  a  titano-colum&te  of 
uranium  (UO*  21  p.c.)  and  lead,  is  from  Samiresy 
near  Anteirabe.  In  blomstrandite  a  part  of 
the  columbium  is  replaced  by  tantalum.  (A. 
Lacroix,  Mindralogie  de  la  France  et  de  ses 
colonies,  1913,  vol.  v.)  L.  J.  S. 

BETAINE     (CH,),N<^^;^CO     may     be 

regarded  as  the  internal  anhydride  of  the 
acid  (CH,),N(OH)CH,COOH  derived  from 
acetic  acid  by  the  replacement  of  one  atom  of 
hydrogen  by  trimethyl  hydroxyammonium. 
It  occurs  in  beets  and  mansolcb  (especially 
unripe  roots),  in  cotton  seed,  m  the  shoots  of 
barley,  in  wormseed  {Artemisia  gfJlica)  and  in 
many  other  plants,  often  in  association  with 
choline,  from  which  it  may  readily  be  obtained 
by  oxidation.  For  observations  on  the  localisa- 
tion of  betaine  in  plants  and  its  part  in  the 
nitrogen  metabolism,  see  Stands  (Zeitsch. 
physiol.  Chem.  1911,  72,  402).  Betaine  is  found 
m  the  extracts  of  muscles  from  the  scallop, 
periwinkle,  and  lamprey. 

Betaine  can  be  synthesised  by  the  inter- 
action of  chloracetio  acid  and  trimethylamine 
(Liebreich,  Ber.  1869,  2,  13).  It  can  also  be 
obtained  by  the  action  of  a  methyl  haloid  upon 
methyl  dimethylaminoacetate  (J.  Chem.  Soc. 
Abst.  1914,  1,  938). 

It  can  be  extracted  from  beet-root  molasses 
by  dilution  with  water,  boiling  with  barvta, 
filtering,  precipitating  the  excess  of  BaTi,Oa 
with  COt,  evaporating  the  liquid  to  small  volume, 
and  extracting  with  alcohol.  The  alcoholic 
solution  ii  treated  with  alcoholic  zinc  chloride, 
the  ppt.  recrystaUised  from  water  and  decom- 
posed by  baryta  water.  The  barium  is  then 
exactly  removed  from  the  filtrate  by  H1SO4,  and 
betaine  hydrochloride  crystallises  on  evaporation 
(Liebreich,  Ber.  3,  161 ;  Friihling  and  Schuk, 
Ber.  10,  1070). 


586 


BETAINE. 


Urban  (Zeiteoh.  Zudcerind.  Bohm.  1913,  37, 
339)  givoB  the  followixig  method.  The  evapo- 
rated molaaaes  reeidues  are  mixed  with  an 
equal  volume  of  concentrated  hvdroobloric  acid. 
After  cooling,  the  alkali  ohlondes  which  have 
separated  are  removed  by  filtration,  and  the 
filtrate  i*  evaporated.  The  volatile  oiganio 
aoide  and  hydrochloric  acid  paas  away,  and 
hnmus  Bubstances  are  precipitated.  These  are 
also  filtered  off,  and  the  residue  further  evapo- 
rated to  a  thick  syrup.  This  is  dissolved  in 
water,  filtered,  decolourised  by  charcoal,  and 
concentrated,  when  nearly  pure  betaine  hydro- 
chloride separates  out  (c/.  flhrlich,  Ber.  1912, 
45,  2409 ;  also  Andrlik,  Z.  Zuckerind,  Bohm. 
1915,  39,  387  ;  J.  Soc.  Chem.  Ind.  1915,  i.  781 ; 
J.  Soc.  Chem.  Ind.  1915,  1064). 

A  general  method  of  obtaining  betaine  from 
plant  extracts  is  to  precipitate  with  lead  acetate, 
filter,  remove  the  lead  by  sulphuretted  hydrogen, 
filter,  evaporate  to  dryness,  extract  residue  with 
alcohol,  and  precipitate  with  alcoholic  mercuric 
chloride.  The  mercuric  double  salt  is  then 
recrystallised,  decomposed  by  sulphuretted 
hydroffen,  and  the  hycLrochloride  obtamed  from 
the  scuution  by  evaporation.  If  choline  is  also 
present,  it  can  be  removed  from  the  mixed 
nydrochlorides  by  extraction  with  cold  alcohol, 
leaving  the  betaine  hydrochloride  (Schulze, 
Zeitsch.  physiol.  Chem.  1909,  60,  165). 

Betaine  crystallises  from  alcohol  in  larsre 
crystals  contaming  one  molecule  of  water.  It 
is  deliquescent  in  air,  and  loses  its  water  when 
dried  over  sulphuric  acid.  Strong  sulphuric 
acid  has  but  little  action  upon  it,  even  at  120^ 
(Stan^k,  Zeit.  Zuckerind,  Bohm,  1902,  26,  287). 

It  is  neutral  to  litmus,  and  has  a  sweet  taste. 
It  melU  and  decomposes  at  293''  (Willstatter, 
Ber.  1902,  35,  584),  giving  off  the  smell  of  tri- 
methylamine  and  of  burnt  susar.  The  auri- 
chloride  C.Hi|NO,*HCl*AuCL,  forms  plates  or 
needles  which  melt  at  209''  (Willstatter),  or,  ac- 
cording to  Fischer  (Ber.  1902,  35,  1593),  at  250"*. 
The  platinichloride  Pta.2(C4H„NO,,HCl),4H,0 
forms  laige  plates ;  after  losing  its  water  it 
melts  and  decomposes  at  242"*  (Willstatter). 

CgHiiNOa'Hui  is  very  soluble  m  water, 
slightly  soluble  in  cold  alcohol.  C.H,iNOa*HI 
is  soluDle  in  water  or  boiling  alcohol,  and  melts 
at  188*'-190^.  A  compound  with  KI  crystallises 
as  (C,H,iN0,),-KI,2H,0,  m.p.  139°  (Komer  and 
Menozzi,  Gazz.  chim.  ital.  13,  351),  or,  if  anhy- 
drous, at  228''-229''  (Willstatter). 

Stoltzenberg  (Zeitsch.  physiol.  Chem.  1914, 
92,  445)  prepared  the  following  compounds  of 
betaine : — 

The  hydrofluoride  and  acid  hydrofluoride, 
basic  hydrochloride(C5H,  ,NO,),HCrH,0,  mono- 
clinic  prisms,  m.p.  250°  (decomp.) ;  CfHi^NOs' 
HBr,  m.p.  233°  (decomp.) ;  basic  hydrobromide 
(C,Hi,NO,),HBr,  prisms,  m.p.  262°;  basic 
hydriodide  (C,UiiNO,),HI,  frittering  plates, 
m.p.  242° ;  basic  aurichlonde  5C5H|iNOt. 
4AuCl^'H,0,  yeUow  crystalline  powder,  m.p. 
169°  (decomp.) ;  basic  auribromide  5C5H11NO,' 
4AuBr4,  m.p.  185°;  auribromide  C^HiiNO,* 
HAuBr4,  dark  brown  plates,  m.p.  260°  (decomp.); 
two  platinichlorides,  one  with  4H,0,  m.p. 
254°-255°,  the  other  with  3H,0,  m.p.  255°-260* ; 
a  basic  platinichloride  5C.H^NO,•4H,Pta«, 
orange  crystals,  m.p.  246°  (aecomp.) ;  the 
phosphate,  m.p.  199°;  the  sulphate  (CtilxiNOt), 


H^SOf,  rhombic  crystals,  m.p.  180° ;  the 
nitrate,  m.p.  124°;  the  chlorate,  m.p.  115°; 
the  dichromate,  m.p.  226°-227°  (decomp.); 
and  the  permanganate,  m.p.  120°.  llie  chlorate 
and  permanganate  explcrale  on  percussion  or 
rapid  neating. 

On  heating  betaine  with  potassium  hydroxide 
at  200°-220°,  about  one-third  of  the  nitropen  is 
eliminated  as  trimethylamine,  carbon  dioxide 
being  evolved.  The  compound  in  alkaline  solu- 
tion gives  a  hydrochloride  C4H,0,N,HC1,  m.p. 
187°-189°.  The  platinochloride  forms  a  yellow 
crystalline  mass,  m.p.  120°-121°  (Albers,  Chem. 
Zeit.  1913,  37,  1533). 

The  term  *  betaine  *  is  now  generally  used 
for  substances  containing  the  group 

with  other  aikyl-  groups  than  methyl,  or  other 
acyl-  groups  than  acetyl. 

Thus,  dimdhykthylacetylbekUnt  or  (since 
acetyl  is  to  be  understood  if  no  acyl-  group  ia 
mentioned)  dimethykthylbeiaine 

(CH.)Ajj/CH.Vx) 

crystallises  from  alcohol  in  four-sided  plates, 
melting  and  decomposing  at  229°-231°  (Will- 
statter), while  tritnethylbutyrdbeiaine 


(CH,),N 


H I — CHs — CH|"^ 
0- 


crystalliBes  in  colourless  plates  with  3H,0 ;  in 
the  anhydrous  state  it  softens  at  130°  and 
decomposes  at  222°  (Willstatter). 

The  betaines  are  isomeric  with  the  esters 
of  amino-  acids ;  thus,  ordinary  betaine  is 
isomeric  with  methyldimethylaminoacetate 
(CH,),NCH,-COOCH„  a  volatile  oily  liquid, 
b.p.  135°,  while  trimethylbutyrobetaine  is  iso- 
meric with  methyl-7-aimethylanunobutyrate 
(CH,),:NCH,CH,'CH,COOCH„  b.p.  171**- 
173°. 

(For  betaines  of  the  pyridine  series,  see 
Kirpal,  Monatsh.  1908,  29,  471). 

According  to  Schulze  and  Trier  (Zeitsch. 
physiol.  Chem.  1910,  67,  46),  the  three  betaines 
wmch  have  been  isolated  from  plant  tissues  are : 
betaine,  trigonelline  [found  m  fenugreek  by 
Jahns  (Ber.  1885,  18,  2518)  associated  witb 
choline],  and  stachydrine,  found  in  the  tubers 
of  Siaehys  tvberifera  and  in  the  leaves  of  Cilrue 
aurarUium  (v,  Tbiookbllinx  and  Staohtdbikx). 

BetSine  CgHnOsN  {lycine^  oxynevrine)  ooouib 
in  sugar-beet  and  in  numerous  other  plants. 
Oystuline,  m.p.  293°  (dnr),  optically  inactive. 
Sweet  taste.  The  hydro(«loriae  has  been  used 
in  medicine.  It  is  formed  by  the  oxidation  of 
choUne  and  by  the  action  of  trimethylamine 
on  chloroacetic  acid 


CH,aC00H4-NMe,  H 

OlUoroacetto   Trimetbyl- 
acld.  amine. 


ClNMe,CH,<X)OH 

Bet&lne  bydrochloride. 


->  iMe,CH,-00-6 
BetAine. 

The  special  anhydride  noilping  (betaine 
grouping)  characteristic  of  betame  occurs  in 
several  natural  alkaloids,  e,g.  trigonelUtte. 
Naturally  occurring  betaines  of  other  ammo- 
acids  are  betonicine,  ergothioneine,  hypaphorine, 
trimethylhistidine,    trigonelline,    and     staohy- 


BETAINES. 


587 


drine.    See  Barger,  The  Simpler  Natural  Bases , 
ohap  ill.,  L<mgmaD8»  1914.  H.  I. 

BETAHnSi  are  completely  methylated  amino- 
acids  with  qninqaeyaJent  nitrogen.  Bases  of 
this  type  derivea  from  several  of  the  amino- 
acids  of  protein  occur  naturally  in  plants  and 
animals.    Betaine  par  excellence 


(CH,),N<^^^>CO 


is  the  most  important  and  the  simpleet,  being 
trimethylglycine,  and  later  gave  its  name  to 
the  whole  class  (for  the  nomenclature  and 
general  properties  of  which,  see  Willstatter,  Ber. 
1902,  36,  584,  and  S.  Komatsu,  Mem.  CoU.  Soi. 
Kyoto,  1916, 1, 369).  Betaine  (acetobetaine,  oxy- 
neurine,  lycine)  occurs  in  Beta  vulgaris,  the  sugar- 
beet,  and  in  all  other  ChenopodittcecB  examined, 
sporadically  in  a  number  of  other  plants,  in 
mussels,  cuttle  fish,  cravfish,  &c.  For  localisa- 
tion and  migration  of  betfdne  in  plants,  see 
StanTk  (Zeitsch.  physiol.  Chem.  1911,  72,  402 
and  Zeit.  Zuckerind,  BohuL  1916,  40,  300). 
Young  sugar  beets  contain  more  than  older 
ones.  Crude  beet-sugar  may  contain  0-375  p.c. 
of  betaine  (Waller  and  PUmmer,  Proc.  Itoy. 
Soc.  1903,  72,  346).  The  only  practical  natural 
source  is  the  final  mother  liquor  left  aftor 
desaccharification  of  the  molasses  by  strontium, 
which  liquor,  with  20  p.o.  of  wator,  may  con- 
tain 116  grams  of  betaine  per  kilo.  The  extrac- 
tion of  Mtaine  is  apparently  best  carried  out 
by  vigorous  agitation  with  96  p.c.  idcohol. 
After  evaporation  of  the  alcohol  the  betaine  is 
converted  into  chloride  and  crystallised  as 
such.  Yield  of  the  liquor  of  pure  chloride 
10-12  p.c.  of  the  liquor  employed  (Ehrlich, 
Ber.  1912,  45,  2409;  D.  R.  P.  157173;  c/. 
Stoltzenberg,  Ber.  1912,  45,  2248;  D.  R.  P. 
243332  ;  and  Chem.  Zentr.  1914,  L  22  ;  Urban, 
Zeit.  Zuckerind,  Bohm.  1913,  37,  339; 
Andrlik,  ibid.  1915,  39,  387). 

Betaine  is  also  obtained  by  the  oxidation  of 
choline  (*  oxyneurine,*  liebreich,  1869),  by  the 
methylation  of  glycine  and,  as  chloride,  by  the 
action  of  trimethylamine  on  chloracetic  acid. 
A  synthesis  by  heating  methyldimethvlamino- 
aoetato  with  methvl  halides  and  subsecnient 
hydrolysis  of  the  betaine  ester  with  acids  is 
stated  to  give  a  quantitative  yield,  and  has 
been  patented  (D.  R.  P.  269338).  For 
the  isolation  from  plant  extracts  (Schulze) 
and  estimation  (Stan6k),  see  the  article  on 
Choline. 

Betaine  crystaUiBes  from  alcohol  in  deli- 
quescent crystals,  which  lose  one  molecule  of 
water  at  100^,  presumably  changing  from  the 
ammonium  hydroxide  to  the  cyclic  anhydride. 
It  melts  at  293°  with  partial  isomerisation  to 
methyldimethylaminoacetato  (Willstatter,  l.c). 
It  is  a  very  feeble  base,  and  neutral  to  litmus. 
The  chloride  C1(CH,),N'CH.-(X)0H  forms  leaflets 
very  soluble  in  water,  and  peculiar  among  the 
chlorides  of  oiganic  bases  in  being  hardly 
soluble  in  alcohol  (1  part  in  365  c.c.  at  room 
temperatures;  separation  from  choline  and 
other  bases).  This  salt  has  a  strongly  acid 
reaction  and  has  been  used  as  a  solid  surotitute 
for  hydrochloric  acid  under  the  name  *  acidol ' 
in  the  preparation  of  tablets,  &c.  (c./.  acid  pepsin 
tablets,  D.  R.  P.  172862).  When  pure  it  is  a 
convenient    standard    for    alkalimetry.    The 


aurichloride  C,fliiO,N-fiAua4  is  the  most 
characteristic  derivative,  and  is  dimorphous; 
regular,  m.p.  209°,  and  rhombic,  m.p.  248°- 
250°  (Fischer,  Ber.  1902,  35,  1693 ;  WiUstattor, 
ibid.  2700).    The  plaiiniehhride 

(C,HnO»N),H,PtCl„ 

m.p.  242°,  crystallises  from  hot  water  in  anhy- 
drous needles,  which  in  contact  with  the  aqueous 
mother  liquor  form  four-sided  tables  with  4H,0 
(Trier,  Zeitsch.  physiol.  Chem.  1913,  85,  372), 
who  recommends  tms  as  a  test  for  betaine).  The 
picrtUe,  m.p.  180°,  may  also  be  used  for  the 
separation  trom  mixtures.  A  large  number  of 
other  salts  have  been  described  by  Stoltzenbei^ 
(Zeitsch.  physiol.  Chem.  1914,  92, 446).  Betaine 
is  not  a  nitrogenous  food ;  it  has  no  appreciable 
action  on  animals,  and  the  part  playeoT  by  it  in 
plant  economy  is  obscure. 

Other    betaines    occurring    naturally,    are: 
Staehydrine 

CH,-CH<<^>0 
(iHg-CH^(CH,), 

1 

the  betaine  of  a-pyrrolidine  carboxylic  acid 
(proline)  was  discovered  in  the  edible  tubers  of 
Stachys  iubifera  (Von  Planta,  Ber.  1890,  23, 
1 699),  and  occurs  in  a  few  other  plants.  Accord- 
ing to  Yoshimura  and  Trier  (Zeitsch.  physiol. 
Chem.  1912,  77,  290),  the  alkaloid  chrysanthe- 
mine  described  by  Marino-Zuco  as  occurring  in 
Dalmatian  insect  powder  (ChrysafUhemum  etne- 
rariaefolium)  is  a  mixture  of  staehydrine  and 
choline.  Staehydrine  has  been  obtained  synthe- 
tically by  methylating  proline  (Engeland,  Ber. 

1909,  42,  2962),  and  from  the  methyl  estor  of 
hygric    acid    (Trier,    Zeitsch.    physiol.    Chem. 

1910,  67,  324). 
BetoniciTie 


HOCH--CH<^^^ 
ciH|-CH;^(CH,), 


is  dextro  rotatory  oxyproline  betaine  and  turicine 
its  stereoisomer.  Both  occur  in  Bekmica 
officinalis  and  have  been  obtained  by  methylating 
natural  oxyproline  (Kiing,  Zeitsch.  physiol. 
Chem.  1913,  85, 217),  and  natural  4-hydrohyffric 
acid  (Goodson  and  Clew^r,  Trans.  GheoL  Soc. 
1919,  116,923). 
Trinu^ylhisiidine 

.NH— CH  (CH,),N — 0 

^N 0-CH,— CH— CO 

the  betaine  of  histidine,  has  been  obtained 
from  fungi  (Kutscher,  Zentralbl.  f.  Physiol. 
1910,  24,  776 ;  Renter,  Zeitsch.  physiol.  Chem. 
1912,  78,  167),  and  by  the  oxidation  of  ergothio- 
neine  (Barger  and  Ewins,  Biochem.  J.  1913,  7, 
204).  The  latter  base  contains  an  additional 
sulphur  atom  in  the  glyoxaline  ring  and  occurs 
in  eigot  {q.v.). 
Hypaphorine 


0 


— ,.— CH,-CH— CO 

\Z  (CH,).k— I) 


the  betaine  of  tryptophane,  occurs  in  the  seeds 
of   Eryihrina    Ig^afhorus  of  Java  (Greshoff, 


BETA1I9ES. 


MededMUngen  nit**  Lands  Piantontam,  1888). 
For  cofiftiiation  uid  tjnthenB,  see  Van  Rom- 
bai|h  and  Baiger,  Cbem.  Soc.  Trans.  1911,  99, 

All  the  aboTe  are  derived  from  a-amino- 
acids.    The  next  three  aie  not.     Trigonelline 

CH 

ch!!Jch 

(CH,)jf 1 

the  betaine  of  nicotinic  acid,  has  been  found  in 
quite  a  number  of  plants,  but  generally  only  in 
▼eiy  small  amount.  It  probably  oocurs  in 
many  more  species.  It  was  discovered  in  the 
fenugreek  {TrtgoneUa  Jcenum  grcKum)  by  Jahns 
(Ber.  1886,  18,  2518),  who  later  showed  it  to  be 
identical  with  the  *  methrlbetain '  of  nicotinic 
add,  already  synthesised  by  Hantzsch  (Ber. 
1886,  19,  3140). 
y-Bulyrcbekiine 

(CH,), :  N^H,-CH,^^« 

was  obtained  by  Takeda  (Pfluger*s  Arohiy. 
1910,  133,  365)  from  dog's  urine  after  phos- 

5 horns  poisoning  (which  interferes  with  the 
eaminatins  action  of  the  liver).  It  is  almost 
certainly  i&ntical  with  one,  if  not  with  three, 
of  Brieger*s  putrefaction  bases  (Untersuch. 
tiber  Ptomaine,  i.  p.  27,  Berlin,  1886),  and  was 
first  synthesised  by  Willst&tter  (Ber.  1902,  35, 
584). 

Carnitine,  a-hydrozy-7-btttyrobetaine 

(CHJ.:N<05;I^^>CH0H 

is  a  hydroxy  derivative  of  the  foregoing,  and 
was  isolated  from  meat  extract  (yield  1.3  p.c.) 
by  Qulewitech  and  Kximbeiv  (Zeitsch.  physiol. 
Chem.  1905,  45,  326),  and  ny  Kutscher  (Zeit. 
Unters.  Nahr.  Oenussm.  1905,  10,  528;  'no- 
vain  ').  According  to  the  latter,  it  Ib  identical 
with  a  base  C7H.  ,(J,N,  isolated  from  human  urine 
bv  Bombrowski  (Compt.  rend.  1902,  135,  244). 
Heating  with  banrta  yields  trimethylamine  and 
orotonio  acid ;  phosphorus  and  hydriodic  acid 
reduce  to  y-butyrobetaine.  Racemic  carnitine 
was  probably  synthesised  by  Fischer  and 
Qoddertz  (Ber.  1910,  43,  3272).  The  smaU 
diflPeiences  from  natural  carnitine  were  probably 
connected  with  the  optical  activity  of  toe  latter 
substance. 

Myohynine,  isolated   bv  Ackermann  (Zeit. 
Biol.  1912,  59,  433)  from  the  muscles  of  horses 
and  dogs,  is  probably  Z-hexamethyl-omithine 
(CH,),N(OH)0H,-0H,CH,CH(COOH)N(0H,),OH 

AU  the  above  bases,  or  at  least  all  the  a- 
betainee,  are  without  marked  physiological 
activity. 

For  a  fuller  account  of  betaines,  ae^.  Barger, 
The  Simpler  Natural  Bases,  Longmans,  1914. 

G.  B. 

BETEL*  A  mixture  of  the  leaf  of  the  betel- 
pepper,  Piver  Betle  (Linn.)  with  the  fruit  of 
Areea  catechu  (Linn.)  or  betel  nut  and  chwiam 
(lime  obtained  bv  calcining  shells),  universally 
used  by  the  people  of  Ontral  and  Tropical  Asia 
as  a  masticatory. 

BETEL-NUT.  The  fruit  of  Areca  catechu 
(Linn.)  v.  Abboa  Nut. 

BETH-ABARRA  WOOD*  A  wood  im- 
ported from  the  West  Coast  of  Africa,  much 


valued  for  its  ton^hnew  and  capability  of 
receiving  a  high  polish.  The  inteniioes  ot  the 
fibrssare  filled  witn  a  ydkw  crystalline  sabetanoe 
which  can  be  extracted  from  the  sawdust  bv 
heating  with  distiUed  water  containing  a  little 
sodium  carbonate,  and  precipitating  the  resulting 
daret-colouied  solution  wiui  aoetie  acid.  It  is 
purified  by  repeated  crystallisations  from  80  p.c. 
alcoh<d.  By  precipitating  the  red  solution  with 
hydrochloric  add  and  washing  the  resulting 
precipitate  with  ether,.  Greene  and  Hooker 
(Amer.  Chem.  J.  11,  267)  found  the  crystals  to 
be  identical  in  all  respects  with  lapaohic  add. 

If  differs  from  chraophanio  acid  by  melting 
at  135^  and  in  not  tonmns  a  compound  with 
alum  (Sadtlor  a.  Rowland,  Amer.  Chem.  J. 
1881,  22).  (For  tables  showing  the  difference  in 
the  reactions  of  brasilin,  hematoxylin,  santalin, 
and  beth-a-bana,  v.  Amer.  Chem.  J.  1 1, 49,  and 
Wagner's  Jahr.  28,  637.) 

BETOL    3-MAPHTHOL    SAUCTLATE    v. 

STKTHKTIO  DBUG8.' 

BETOKICINE  r.  Bstaikbs. 

BETORCm  or  /3-ORGIM  CtH^.O,.  A  sub- 
stance  obtained  bv  the  decomposition  of  bar- 
batic  acid,  found  in  the  lichen  D&nea  barbata^ 
It  is  less  soluble  in  water  than  orcin,  and  gives  a 
deeper  crimson  colour  with  hypochlorites. 
Kostanecki  has  obtained  it  by  the  action  of 
nitrous  add  on  m-amino-p-xylenol,  thus  showing 
that  it  is  a  dihydroxy-xylene  (dimethylresordnoQ 
having  the  substituting  groups  in  the  positions 
CH„  CH„  OH,  0H=:1,  4,  3,  5  (Stenhouse  *. 
Groves,  Chem.  Soc.  Trans.  37,  396 ;  Lampartie, 
Annalen,  134,  248;  Menschutkin,  BuU.  Soa 
chim.  2,  428 ;   Kostanecki,  Ber.  19,  2321). 

BETULA  RESIN  v.  Rssnrs. 

BETULOL  CisH,40,  a  biovclic  sesquiterpene 
alcohol  of  the  terben^type  found  in  birch  oil, 

B.P.  157-^58713  mm.,  D1.*0-9777,  n-*j5l-5160, 
a^^-26*5^  Slowly  absorbs  hydrogen  in  pre- 
sence of  platinum  yielding  teirahydrcbetrol, 
b.p.  153**-158714  mm.,  D^^ 09415,  n^®  1-4908, 
a^^-6.8%  and  bicyolic  tetrahyirobeivkne  Ci,H,k, 
b.p.  118^-120711  mm.,  Dl^  0-8737,  »^j§  1-4744, 
a'^— 3^.     For  other  derivatives  see  Semmler, 

(Jonas  and  Richterr  Ber.  1918,  51,  417). 

BEZETTA.  Toumesol  en  drapeaux,  Sckmink' 
lappchen.  Bezetta  rubra  et  ecerulea.  A  dye  or 
pigment  prepared  by  dipping  linen  rags  in  solu- 
tions of  certain  colouring  matters.  Red  besetta  is 
coloured  with  cochineal,  and  is  used  as  a  cosmetic 

Blue  bezetta  {Toumesol  en  drapeaux),  which 
is  chiefly  used  for  colouring  the  rind  of  Dutch 
cheeses,  is  prepued  at  Galmigues,  near  Ntmes, 
in  the  department  of  Gard,  from  a  euphorbi- 
aceous  plant,  Chrozophora  tinctoria  (A.  Juas.) 
[Croton  tinctorius].  The  fruits  and  the  tons  of 
the  plants  are  gathered,  and,  the  juice  being 
expressed,  rags  of  coarse  cloth  are  dipped  into  it, 
then  dried,  and  afterwards  exposed  to  the  fumes 
of  mules*  or  horses*  dung.  Tlus  last  operation 
is  called  aluminadou.  The  doths  are  turned 
from  time  to  time,  to  ensure  uniform  colouration 
and  prevent  any  part  from  being  exposed  too 
long  to  the  fumes  of  the  dung,  which  would 
turn  them  yellow.  They  are  then  dried  a 
second  time,  again  soaked  in  the  juice,  mixed 
this  time  with  urine,  and  lastly  exposed  for  some 
time  to  the  action  of  the  sun  and  wind.    The 


BILBERBT. 


680 


quantity  thus  manufaotured  amounts  to  about 
50  tons  yearly.  The  blue  of  bezetta  is  reddened 
by  acids  like  litmus,  though  not  so  quickly,  but 
difiPers  from  the  latter  in  not  being  restorisd  by 
alkalis.  According  to  Joly,  the  same  dye  may 
be  obtained  from  other  euphorbiaceous  plants, 
•'-^^hrozorphora  dblongaia  [obliqua  (A.  Juss.)  ?], 
C.  'plicata  (A.  Juss.),  Argilhamnia  tricuspidaia 
(Muell.),  Mercurialis  perennis  (Unn.),  and  M. 
tomerUoda  (Linn.).  The  juice  exists  in  all  these 
plants  in  the  colourless  state,  and  turns  blue  only 
on  exposure  to  the  air  (Handw.  d.  Ghem.  2,  [1] 
1030 ;   Gerh.  Traits,  8,  820). 

BEZOAB.  This  name,  which  is  derived  from 
a  Persian  word  signifying  an  antidote  to  poison, 
was  given  to  a  concretion  found  in  the  stomach 
or  intestines  of  an  animal  of  the  goat  kind. 
Copra  aegroffua,  which  was  once  very  highly 
valued  for  tms  imaginary  quality,  and  has  thence 
been  extended  to  all  concretions  found  in 
animals. 

According  to  Taylor  (Phfl.  Mag.  No.  186,  36, 
and  No.  I^,  192),  becoars  may  be  divided 
into  nine  varieties:  1.  Phosphate  of  calcium, 
which  forms  concretions  in  the  intestines  of  many 
mammalia.  2.  Phosphate  of  magnesium; 
semi-transparent  and  yellowish,  and  of  sp.gr. 
2*160.  3.  Phosphate  of  ammonium  and  mag- 
nesium ;  a  oonoretion  of  a  grey  or  brown  colour, 
composed  of  radiations  from  a  centre.  4. 
Oxalate  of  calcium.  5.  Vegetable  fibres.  6. 
Animal  hair.  7.  Ambergris.  8.  LithofeUio 
acid.    9.  EUagio  or  bezoaroic  add. 

Of  true  bezoars  there  are  three  kmds :  Oriental. 
Occidental,  and  German.  The  true  Oriental 
bezoars  found  in  the  Capra  cegmgiu,  the  gazelle 
{OiueUa  dorcas),  and  other  ruminant  animals, 
are  spherical  or  oval  masses,  varying  from  the 
size  of  a  pea  to  that  of  the  fist,  ana  composed  of 
conoentno  layers  of  resinous  matter  with  a 
nucleus  of  some  foreign  substance,  such  as  pieces 
of  bark  or  other  hara  v^geteble  matter  which 
the  animal  has  swallowed.  They  have  a  shining 
resinous  fracture,  are  destitute  of  taste  and  odour, 
nearly  insoluble  in  water  and  aqueous  hydro- 
chlonc  acid,  but  soluble  for  the  greater  part  in 
potash  lye.  These  characters  suffice  to  distin- 
guish the  Oriental  bezoars  from  those  varieties 
which  contain  a  considerable  quantity  of  in- 
organic matter.  There  are  two  kinds  of  them, 
the  one  oonsistinff  of  ellagic,  the  other  of  litho- 
fellio  acid.  The  &tter  have  a  more  waxy  lustre 
and  greener  colour  than  the  former,  and  are  also 
distinguished  by  their  lower  sp.gr.,  viz.  1*1, 
whilst  that  of  the  ellaffic  acid  stones  is  1  *6.  They 
contain,  besides  lithofellic  acid,  a  substence 
resemblinfi  the  colouring  matter  of  bile,  and  are 
perhaps  biliary  calculi.  Oriental  bezoars  are 
greatly  prized  in  Persia  and  other  countries  of 
the  East  for  their  supposed  medical  properties. 
The  Shah  of  Persia  sent  one  in  1808  as  a  present 
to  Napoleon.  The  Occidental  bezoars  are  found 
in  the  lama  {Auehenia  flafna)  and  in  A.  vtcugtM. 
They  resemble  the  Oriental  in  external  appear- 
ance, but  differ  totally  in  their  chemical  cha- 
racters, inasmuch  as  they  consist  chiefly  of  cal- 
cium phosphate,  with  but  little  organic  matter. 
German  bezoars,  which  are  chiefly  obteined 
from  the  chamois  or  gemsbock  (Rupicapra 
tragus),  consist  chiefly  of  interlaced  vegetable 
fibres  or  animal  hairs  bound  together  by  a 
leathery  coating. 


BICUHYBA    FAT«      See    Mtbishoa    fat 

QBOUP. 

BIDRT.  An  Indian  alloy  of  zinc,  copper, 
and  lead,  and  occasionally  tin.  Articles  of  this 
alloy,  after  being  turned  in  a  lathe  and  engraved, 
are  blackened  by  immersion  in  a  solution  of  sal 
ammoniac,  nitre,  common  salt,  aad  copper  sul- 
phate,   ^own  also  as  Vidry, 

BIEBRICH  ACID  BED,  PATEHT  BLACKS, 
8CABLET  PONCEAU  v.  Azo-  ooLOUBiNa  mat- 
ters. 

BIGNONIA    TECOHA.^      TECOMIN.      The 

Bignonia  tecoma  is  a  somewhat  common  toee  in 
the  uplands  of  Minas,  Brazil,  which  when  fully 
ffrown  is  about  30  feet  high  and  in  September 
IS  covered  with  brilliant  yellow  flowers.  The 
natives  mix  the  sawdust  and  shavings  of  this 
tree  with  slaked  lime,  heat  the  mass  with  water 
jeind  employ  the  resulting  bath  to  dye  cotton 
cloth.  A  paste  made  of  tne  sawdust  mixed  with 
lime  is  also  used  to  stein  lighter-coloured  woods 
a  deep  brown.  By  exhausting  the  sawdust 
with  boiling  85  p.c.  alcohol  ana  concentrating 
the  extract,  Lee  (Chem.  Soc.  Trans.  1901,  79, 
284)  isolated  the  colouring  matter  tecomin. 
This,  which  has  apparently  not  been  submitted 
to  analysis,  forms  shining  chrome-yellow  crystals 
possessing  a  nacreous  lustre,  soluble  in  alkalis 
with  a  rose>red  colouration. 

A  further  quantity  of  this  compound  could 
be  isolated  from  the  alcoholic  filtrate,  the  total 
amount  thus  given  by  the  wood  being  approxi- 
mately 6  p.c. 

The  sawdust  extracted  with  alcohol  still 
conteins  a  deep  brown  dye  which  mav  now  be 
removed  from  it  by  alkalis,  and  by  acidification 
this  is  deposited  as  an  amorphous  brown 
powder.  Nothing  is  at  present  known  as 
regards  the  relationship,  if  such  existo,  between 
tecomin  and  the  colouring  matter  of  chica  red 
or  carajura,  which  originates  from  the  Biflnonia 
chica.  A.  Q.  P. 

filKHACONITlNE  v,  Acotininb. 
BILBEBBY.     Vaccinium  MyriiUus  (Linn.). 
K5nig  gives  as  the  average  composition  of  the 

fruit: 

Free  Other  carbo- Grade 

Water  Protein    acid  Sugar  hydrates     fibre       Ash 

78-4       0-8        1*7  6-0       0*9        12*3        1*0 

According  to  Otto  (Bied.  Zentr.  1899,  28, 
2S4),  Silesian  bilberries  contain  from  3-5  to  70 
p.c.  of  sugar  and  acid  corresponding  to  from 
0*9  to  1*6  p.c.  of  tertaric  acid.  He  found 
that  fermentetion  of  the  juice  with  ordinary 
yeast  was  very  dow  unless  some  nitrosenous 
matter  {e.g.  ammonium  chloride  or,  better, 
asparagine  (about  0*6  fnm  per  litre))  were 
aoded.  Bilberries  contain  a  small  quantity  of  a 
wax  melting  at  71*  (Seifert,  Landw.  Versuchs- 
Stet.  1894,  45,  29). 

The  juice  of  bilberries  contains  from  4  to 
9*5  p.c.  of  total  solids,  0*25  to  0*31  p.o.  ash,  and 
acidity  corresponding  to  from  15*6  to  19*6  ac. 
N/1  alkali.  The  juice  contains  some  substance 
wnich  sives  a  blue  colouration  when  heated  with 
hydrocnloric  add.  This  colouration  is  ap- 
parently not  connected  with  the  red  colouring 

>  According  to  Holmes  the  name  Bimumia  tteoma 
does  not  appear  In  tlie  Kew  Index,  but  only 
Bignonia  tieomo^des,  which  li,  however,  a  shrubby 
species. 


590 


BILBERRY. 


matter  of  the  berries  and  appears  to  be  cha- 
raoteristic  of  the  Vacciniacem  for  cranberries, 
Vaccinium  vitis  Idcea  also  yield  the  same 
reaction  (Plahl,  Zeitsoh.  Nahr.  Qenossm.  1907, 

13,  1). 

The  sugar  in  bilberries  is  entirely  invert 
sugar  (Windisoh  and  Boehm,  Zeitsch  Nahr. 
Genuasm.  1908,  8,  347).    The  ash  contains : 

K.0  Na,0  CaO  ICffO  Fe,0,MOs04PaO,  SO,  SiO, 
67-1'  6-2     80     61     11    21     17-4     3J     0-9 

(Borggreve  and  Homberger,  Bied.  Zentr.  1886, 
487). 

Bilberries  contain  a  red-brown  dye,  insoluble 
in  acidified  water  and  a  soluble  dye  which,  when 
boiled  with  acid,  yields  sugar  and  the  insoluble 
colouring  matter  (Weigert,  Bied*  Zentr.  1896, 
20,  58). 

The  juice  of  this  berry  (Ger.  Heidelbeert) 
is  used  for  oolourinff  wines.  The  colouring 
matters  of  grapes  and  of  bilberries  behave  in 
an  almost  identical  way  with  most  reagents 
(Andr^e,  Arch.  Pharm.  [3]  13,  90;  Ber.  13, 
582 :  Plahl,  Chem.  Zentr.  1907,  L  837). 

To  detect  bilberry  juice  in  wine,  50  cc.  of 
the  wine  is  made  famtly  alkaline  with  sodium 
hydroxide,  and  evaporated  to  half  its  volume. 
After  cooling  it  is  made  up  to  the  original  volume 
and  precipitated  with  lead  acetate.  The  filtrate 
is  then  precipitated  i^ith  sodium  sulphate  and 
alter  filtration  thtf  solution  is  acidified  with 
hydrochloric  acid.  If  any  vegetable  colouring 
matter  is  still  present,  the  solution  at  once 
becomes  red,  but  the  blue  colour  given  by 
bilben^  only  appears  on  heating  the  solution  in 
a  boilmg  water-bath.  In  this  way  2  p.c.  of 
bilberry  juice  can  be  detected  (Plahl,  Chem. 
Zentr.  1908,  L  1482). 

According  to  Vogel  (Ber.  21,  1746),  the 
oolourinff  matter  of  f;rapes  and  of  bilberries  can 
be  readily  distinguished  by  their  absorption 
spectra,  providing  the  wine  is  not  too  concen- 
trated, and  after  adding  a  trace  of  alum  solution, 
it  is  carefully  neutralised  with  ammonia.  After 
long  keeping,  however,  the  colouring  matters 
eannot  be  distinguished  in  this  way. 

The  colouring  matter  of  the  juice  can  be 
extracted  by  neutralising  it  with  caustic  sodia  and 
then  treating  it  with  hide  powder.  After  two  days 
the  hide  powder  containing  the  colouring  matter 
is  filtered  off,  washed  with  water,  and  treated 
with  dilute  hydrochloric  acid,  after  which  it  is 
precipitated  with  dilute  soda.  The  colouring 
substance,  probably  Cio^itOs*  ^  soluble  in 
mineral  and  oiganio  acids,  but  insoluble  in  water, 
alcohol,  ether,  chloroform*  or  benzene.  It 
reduces  Fehling's  solution,  and  is  decomposed  by 
hot  cone,  sulphuric  acid,  a  compound  Ut4H|407 
being  thrown  down  when  water  is  added  to  the 
red  solution  thus  obtained.  The  oolourinff 
matter  is  oxidised  by  nitric  acid  to  oxalic  and 
picric  acids.  It  slowly  decomposes  on  stand- 
ing, evolving  carbon  dioxide^  and  its  solution 
when  treated  with  copper  sulphate  or  zinc 
chloride^  turns  violet;  with  lead  acetate  it  turns 
blue,  and  with  ferric  chloride  dark  -  brown 
(Nachen,  Chem.  Zentr.  1895,  66,  1084). 

Considerable  quantities  of  citric  and  malic 
acids  are  present  in  the  juice,  which  also  contains 
hydrocarbons,  glucoses,  pentoses,  and  inositol 
(Nachen,  l.cJ),  Ammonia  turns  bilberry  juice 
a  brownish -green ;  nitric  acid  in  the  cold  blue, 


changing  to  red  and  becoming  oran^  on  boiling ; 
lead  acetate  gives  a  blue  precipitate,  copper 
sulphate  a  violet  colour,  scxlium  carbonate  a 
blue-black,  and  borax  an  amaranth  red 
(Griessmayer.  Chem.  Zentr.  8,  381). 

When  chlorine  is  passed  into  the  juice,  a 
bright-grev  amorphous  precipitate  is  obtained 
(Nachen,  I.C.). 

(For  quantitative  analysis  of  the  juice,  com- 
pare Mathes,  Muller,  and  Ramstedt  (Chem. 
Zentr.  1905,  L  407);  Lfihring,  Bohrisch*  and 
Hepner  (ibid,  1907,  iL  1755);  Shamm  and 
Jegin  {ibid,  1907,  L  983) ;  Behre,  Grosse,  and 
Schmidt  (ibid.  1909,  L  456).) 

When  the  juice  is  fermented,  the  produota 
include  aldehyde,  and  capric,  propionic,  valeric, 
and  butyric  acids  (Nachen,  2.c). 

Wine  has  been  prepared  from  bilberry  juice 
by  allowing  it  to  ferment  spontaneously  whea 
mixed  with  a  third  its  weignt  of  honey.  Th& 
wine  thus  prepared  bears  prolonged  storage,  is 
rich  in  alcohol  and  tannin,  is  of  a  rich  clear 
colour,  and  has  an  agreeable  flavour  (Graftien, 
Bl.  Assoc.  Beige  des  chim.  12,  [3]  107 ;  Otto, 
Bied.  Zentr.  1899,  28,  284). 

When  bilberries  are  extracted  with  ohloro* 
form,  the  solution  evaporated,  and  the  residue 
extracted  with  light  petroleum,  the  soluble  portion 
yields  a'wax,  m.p.  7 1  ,  and  a  crystalline  compound, 
probably   vdin,    m.p.    255*-260*    [o]j^+60-72« 

(Seifert,  Landw.  Versuchs-Stat.  45,  29). 

BILE.  Bile  is  the  secretion  of  the  liver  which 
is  poured  into  the  duodenum  (the  first  part  of 
the  small  intestine).  It  can  be  collected  in 
animals  by  means  of  a  biliary  fistula ;  the  same 
operation  has  occasionally  oeen  performed  in 
human  beings.  After  death,  the  gall  bladder 
yields  a  good  supply  of  bile,  which  is  more 
concentrated  than  that  obtained  from  a  fistula. 
The  amount  of  bile  secreted  is  difierentlpr 
estimated  by  different  observers;  in  man  it 
probably  varies  from  500  to  1000  ao.  per  diran. 

Its  constituents  are  the  bile  salts  proper 
(sodium  glycocholate  and  taurochoUte),  the  bile 
piffments  (bilirubin  and  biliverdin),  a  mudnoid 
substance,  small  quantities  of  fats,  soap^ 
cholesterol,  lecithin,  urea,  and  mineral  salts,  of 
which  sodium  chloride  and  the  phosphates  of 
calcium  and  iron  are  the  most  important. 

Bile  is  a  yellowish,  reddiBh-brown,  or  green 
fiuid,  accordmff  to  the  relative  preponderance 
of  its  two  chief  pigments.  It  has  a  musk-like 
odour,  a  bitter-sweet  taste,  and  is  alkaline  to 
litmus.  The  specific  gravity  of  human  bile  is 
1*026  to  1-032  from  the  gall  bladder,  and  about 
1*011  when  derived  from  a  fistula.  The  greater 
concentration  of  ffall-bladder  Inle  is  partly 
explained  by  the  a<raition  to  it  from  the  wall  A 
that  cavity  of  the  mucinoid  material  it  seoretea. 
The  following  table  will,  however,  show  that 
the  low  percentage  of  solids  in  fistula  bile  is  due 
mainly  to  paucity  of  bile  salts.  This  is  accounted 
for  in  the  way  first  suggested  by  Schiff — that 
there  is  normally  a  bile  circulation  goinff  on  in 
the  body,  a  large  quantity  of  the  bile  safis  tJiat 
pass  into  the  intestine  being  first  split  up,  then 
re-absorbed  and  again  synttesised  and  secreted. 
This  would  obviouslv  be  impossible  in  easeo 
where  all  the  bile  is  aischarged  to  the  exterior 
through  a  fistula.  The  following  is  the  table  in 
question,  the  results  being  the  mean  of  several 
analyses  of  human  bile : — 


BILE. 


691 


Conttttiwinti 
Bile  MbltB 

Cholesterol,  lecithin,  fat 
Muoinoid  material 
Pigment .         •         • 
Ash     ^  •         •        • 


Fistula  Oftn-bladdef 


bUe 

0-42 

0-07 

017 

007 

0-66 


} 


bile 

914 

M8 

2-98 
0-78 


Total  solids      .  .     1*39        14-08 

Water  (by  difference)         .  98-61        85-92 
For  methods  of  analysinff  human  bile,  8tt  v. 
Czyhlaiz,  Fuchs  and  v.  Fiirth,  Bioohem.  Zeitsoh. 
1913,  49,  120  ;  Analyst,  1913,  208. 

The  Fd  hovinwn  pwificalum  of  the  pharma- 
oopoeia  is  made  by  mixing  ox  bile 'with  twice  its 
volnme  of  rectified  spirit :  this  is  set  aside  for 
12  hours  nntil  the  sediment  subsides ;  the  clear 
solution  is  decanted  and  evaporatcKl  on  the 
water  -  bath  until  it  acquires  a  consistence 
suitable  for  forming  pills.  The  material  so 
obtained  consists  mainly  of  bile  salts,  cholesterol, 
fats,  salts,  and  a  certain  amount  of  the  mucinoid 
materiaL  Its  yellowish-green  colour  is  due  to 
bile  pigment.  It  is  given  in  doses  of  5  to  10 
grains,  usually  as  pilu  coated  with  keratin  to 
obviate  its  deleterious  action  on  gastric  digestion. 
It  is  ffiven  mainly  in  cases  where  the  natural 
secretion  is  absent  or  scanty,  as  in  jaundice. 
But  for  a  full  description  of  its  medicmal  uses, 
and  also  for  a  description  oi  the  action  of  drugs 
(cholagogues)  which  stimulate  the  liver  either 
to  secrete  more  bile  or  to  cause  a  discharge  of 
bile  already  formed,  the  reader  is  referred  to  any 
standard  iext-book  on  Pharmacology. 

PkMner*s  crystaUind  tnle.  The  bile  salts 
are  sc^uble  in  water  and  in  alcohol,  but  not  in 
ether.  Their  solution  in  alcohol  is  therefore 
precipitated  by  ether,  and  this  precipitate  gives, 
with  proper  precautions  in  technique,  rosettes 
or  baUs  of  mie  needles,  or  4r-6  sided  prisms 
composed  of  the  bile  salts.  This  preparation  is 
known  as  Plattner's  crystallised  bile;  it  is 
nsuaUy  made  from  ox  bde,  in  which  case  the 
main  constituent  is  sodium  ^ycocholate. 

The  hiU  saUs.  The  sodium  salts  of  glyco- 
oholio  and  taurocholic  acids  are  those  most  fre- 
quently found.  The  former  is  more  abundant  in 
the  bile  of  man  and  herbivora,  the  latter  in  car- 
nivora.  Glycocholic  aoid  (CmH4,N0c)  is  by  the 
action  of  cUlute  alkalis  and  acids,  and  a)so  in 
the  intestine,  hydrolysed  and  split  into  glycine 
(amino-acetic  add),  and  cholalic  (cholic)  acid 

C„H«NO.+H,0=C,H^O,-fC„H«0, 

Its  sodium  salt  has  the  formula  G,,H4^aN0c. 
Taurocholic  acid  (Ct«H4BN07S)  similarly  splits 
into  taurine  (amino-ethyl  sulphonic  acid)  and 
cholalic  acid 

CmH|sNO^-I'H,OsO,H4-NH,-HSO,-I-C,«H4oO, 

Its  sodium  salt  has  the  formula  C24H44NaNO  ,8. 
These  substances  usually  are  detected  by 
Pettenkofer's  reaction;  small  quantities  of 
cane  sugar  and  sulphuric  acid  added  to  the  bile 
produce  a  brilliant  purple  colour.  This  is  due 
to  the  interaction  of  furfuraldehyde  (produced 
from  the  sugar  and  sulphuric  acia)  ana  cholalic 
add. 

Throughout  the  animal  kingdom  considerable 
variations  are  found  in  the  bue  salts.  Thus  in 
many  fishes  potassium  instead  of  sodium  salts 


are  present.  There  are  also  variations  in  the 
bile  acids  themselves ;  for  instance,  in  the  pig 
hvoglycocholic  acid  (C|7H4sNOb)  tc^es  the 
place  of  ordinary  glycocholic  acid,  and  in  the 
goose  ohenotaurooholic  acid  (Cg»H4,NS0«)  of 
ordinary  taurocholic  add. 

A  good  deal  of  work  has  been  expended 
on  the  constitution  of  cholalic  acid,  but  much 
vet  remains  to  be  done.  According  to  Mylius,  it 
IS  a  monobasic  alcohol  acid  with  a  secondary 
and  two  primary  alcohol  groups.    Its  formula 

ICHOH 
(CH,OH)..  On 
(X)OH 
oxidation  it  3aelds  other  acids,  which  have 
been  named  dehydrocholalic  acid  (C|4Hg40(), 
bilianic  acid  iC^^^fig),  dlianic  acid  (G,oHgi,Og); 
on  reduction  aesoxycholalic  acid  (0g4H4«O4) 
is  obtained. 

Gholdo  acid  is  another  cholalic  add,  with  the 
formula  Cg4H4o04,  found  in  small  quantities  in 
the  bile  of  ox  and  man.  It  is  probably  identical 
with  desoxycholalic  acid.  Feluc  acid  (OtgH4o04) 
IB  still  another  add  obtainable  from  human  bile 
along  with  the  ordinary  add.  The  principal 
cholalic  acid  in  bear's  bue  is  termed  urBOQhoidc 
add  (Ci8Hgs04  or  Oi,Hgo04)  by  Hammarsten. 
The  same  investigator  finds  in  the  walrus  that 
the  principal  bile  adds  are  a-phoc«taurocholic 
acid,  the  cholalic  acid  from  which  has  the 
formula  OggHgoOg ;  and  )3-phocetaurocholic 
acid,  the  cholalic  add  from  which  differs  in 
certain  particulars  from  ordinaty  cholalic  add, 
although-  it  has  the  same  empirical  formula ; 
he  terms  it  iaocholalic  acid. 

The  bUe  pigments.  Bilirubin  has  the  formula 
Cg,HggN40g,  and  biUverdin  contains  more 
oxygen  (Ci4Hi,Ng04)n  ;  in  bile  exposed  to  the 
air,  bilirubin  Ib  &irly  rapidly  oxidised  to 
biliverdin.  It  has  been  proved  iy  physiological 
experiment  that  the  bile  pigment  is  an  iron-free 
derivative  of  the  blood  pigment ;  it  is,  in  fact, 
identical  with  the  substance  termed  htematoidin, 
which  occurs  usually  in  crystalline  form  in 
extravasations  of  blood  in  the  body,  as  in  a 
bruise.  The  bile  pigment  shows  no  absorption 
bands  with  the  spectroscope,  and  \b  detected  by 
various  colour  reactions,  of  which  the  most 
familiar  is  Gmelin*s  test ;  this  consists  in  the 
play  of  colours — green,  blue,  red,  and  finally 
yellow — ^produced  by  the  oxidisinff  action  of 
fuming  nitric  acid.  The  end  or  yellow  product 
IB  calfed  choletelin  {O^fizJ^fiiJj*  By  reduc- 
tion outside  the  body,  a  product  called  hydro- 
bilirubin  (CggH4oN407)  \b  obtained.  A  similar 
but  not  identical  reduction  product  containing 
less  nitrogen  than  hydrobilirubin  is  formed  in 
the  intestine,  and  constitutes  stercobilin,  the 
pigment  of  the  feces.  Some  of  this  Ib  absorbed 
and  ultimately  leaves  the  body  in  the  uzine, 
where  it  is  termed  urobilin.  A  small  quantity 
of  urobilin  ia  sometimes  found  preformed  in  the 
bile. 

BiU  mvjcin.  The  viBCous  material  in  the 
bile  of  some  animals  {e,g.  man)  \b  true  mucin ; 
in  other  {t,g.  the  ox)  it  is  a  nucleoprotein. 

Choluterol.  Of  the  other  constituents  of 
the  bile,  cholesterol  or  cholesterin  is  the  most 
interesting ;  although  normally  present  in  traces 
only,  it  may  occur  in  excess  and  form  the  con- 
cretions known  as  gall  stones,  which  are  usually 
more  or  less  tinged  with  bile  pigment.    It  iB  a 


502 


BILE. 


monaiomio  unflatarated  alcohol,  with  the 
empirioal  formula  0,fH4,*0H.  Windaus  and 
others  have  shown  that  it  is  a  member  of  the 
terpene  series,  which  had  hitherto  only  been 
found  as  excretory  oroducts  of  plant  life. 

The  physidogteat  uaea  of  bile. — Bile  is  doubt- 
lees  to  some  extent  an  excretion.  Some  state 
that  it  has  a  slight  lipolytic  action;  and  in 
some  animals  it  certainly  haa  a  feeble  diastatic 
power.  Its  main  action,  however,  is  to  assist 
pmcreatio  digestion;  this  it  does  not  only 
because  its  alkalinity  is  useful  in  helping  to 
neutralise  the  acid  mixture  which  leaves  the 
stomach  (chyme),  but  it  also  acts  as  a  coadjutor 
to  the  enzymes  of  panoreatio  juice.  Tlus  is 
true  for  the  proteol3rtic  enzyme  (trypsin),  and 
the  amylolytio  enzyme  (amylopsin),  but  is 
especially  so  in  the  case  of  pancreatic  lipase; 
some  go  so  far  as  to  speak  of  tne  bile  salts  as  the 
co-enzyme  of  this  ferment. 

In  virtue  of  the  properties  which  the  bile 
salts  possess  of  lowering  surface  tension,  the 
products  of  fat-deava^e  pass  more  rapidly 
through  membranes  moistened  with  bile  than 
through  these  which  are  not.  There  is  a  good 
deal  of  evidence  that  the  same  holds  intra  vttam, 
and  thus  the  presence  of  bile  aids  the  absorption 
of  fats  by  the  mucous  membrane  which  lines 
the  intestinal  walL  Bile  also  is  a  solvent  of 
fattyacids. 

When  the  bile  meets  the  chyme,  the  turbidity 
of  the  latter  is  increased  owing  to  the  precipita- 
tion of  unpeptonised  protein.  TbiB  action  of  the 
bile  salts  is  probably  useful*  as  it  converts  the 
chyme  into  a  more  viscid  mass,  and  somewhat 
hinders  its  proffress  along  the  first  part  of  the 
intestine,  so  allowing  digestion  and  absorption 
to  occur  there. 

Bile  is  said  to  be  a  natural  antiseptic,  but  it 
is  very  doubtful  if  it  is  reaUy  efficient  m  reducing 
the  putrefactive  processes  in  the  bowel.  Ttie 
bile  salts  are  in  vitro  ver^  feeble  germicides, 
and  the  bile  itself  la  readily  putrescible;  any 
power  it  may  have  in  lessening  putrescence  in 
the  intestine  is  due  chiefly  to  the  fact  Uiat  by 
increasing  absorption  it  lessens  the  amount  of 
putrescible  material  in  the  intestinal  tract.  It 
IS  .stated  also  that  bile  increases  the  peristaltic 
action  of  the  lai^  intestine. 

Industrial  and  commercial  uses  of  bile. — 
Apart  from  a  somewhat  limited  use  as  a  thera- 
peutic agent,  to  which  allusion  has  already  been 
made,  bile  has  but  little  commercial  importance. 
It  is,  however,  employed  for  cleansing  woollen 
goods,  and,  as  housekeepers  know,  is  specially 
useful  in  cleaning  carpets.  This  is  probably 
connected  with  its  power  of  lowering  surface 
tension.  Bile  is  also  used  by  artists  to  ensure 
the  uniform  spreading  of  water  colours  on  paper. 

No  attempt  has  been  made  in  the  foregoing 
article  to  allude  to  the  very  extensive  literature 
of  bile.  This  relates  almost  exclusively  to  the 
physiology  and  patholoaar  of  bile,  and  the 
important  references  can  oe  best  obtained  from 
some  standard  work  on  Physiological  Chemistry. 

W.  D.  H. 

BIOOEN  or  MAGNESIUM  PERHYDROL. 
Trade  name  for  a  mixture  of  magnesia  and 
magnesium  peroxide. 

BIOTITE  V.  MiOA. 

BIRCH  BARK.  Betula.  {Birke,  Qer.; 
Bouleau,  Ft.)    The  inner  bark  is  used  in  India 


as  a  substitute  for  paper  and  for  lining  the  rocf s 
of  houses  (^ymock,  Fliarm.  J.  [3]  10,  061). 

It  contains  good  tanning  materials,  yielding 
bright-yellow  leather  (Wagner's  Jahr.  HO,  1206 ; 
Trotman  and  Hackford,  J.  Soa  Chem.  Ind.  1906^ 
1006 ;  Bogh,  Chem.  Zentr.  1906,  L  1915). 

The  drjr  distillation  of  birch  bark  yields  a 
tar  and  an  acid  aqueous  solution  (Kuriloff, 
J.  Russ.  Phys.  Chem.  Soc.  23,  98).  The  chief 
constituents  of  birohwood  tar  creosote  are 
guaiacoland  1:3:  4-oreosol,  together  with  traces 
of  phenol,  cresol,  and  1:3: 4-xylenol  (Pfreager, 
Arch.  Pharm.  228, 713).  Accordmg  to  Hirsohsohn 
(Pharm.  Gentr.  H,  1903,  44,  846)  birch  tar  is 
often  adulterated  with  crude  naphtha  or 
naphtha  residues,  but  the  adulterated  oan  be 
distinsnished  from  the  pure  product  by  the 
fact  that  the  former  is  only  partially  soluble  in 
acetone,  whereas  the  latter  is  wholly  soluble. 

When  warm  birch  tar  is  treated  with  air, 
oxyeen,  or  ozonised  air,  a  pleasant-smelling  aolid 
product  is  obtained,  soluble  in  alkalis,  bat  almost 
insoluble  in  alcohol,  benzene,  and  ether.  It  and 
its  salts  can  be  employed  in  medicine,  phannaoY, 
and  technically.  At  the  same  time,  readilv 
condensible  liquid  products  distil  over,  which 
can  also  be  used  medicinally  and  technfoally, 
as  antiseptics  and  in  perfumery  (Friedl&nder's 
Fortschr.  der  Teerfabr.  1905-7, 930). 

A  colouring  substance  employed  in  pharma- 
ceutical and  cosmetic  preparations  is  obtained 
when  the  bark  of  young  birch  trees  Is  soaked  in 
water  containing  about  Jp  of  its  weight  of 
bicarbonate  of  soda  or  other  carbonate.  It  is 
then  boiled  and  filtered.  ■  Hydrochloric  acid  is 
added  to  the  red-brown  filtrate  until  a  pre- 
cipitate is  formed  which  is  filtered,  washed,  and 
dned  at  a  gentle  heat.  It  should  be  kept  in  well- 
stoppered  vessels  (Eriedlander's  Fortschr.  der 
Teerfabr.  1897-00,  661). 

The  bark  contains  a  crystalline  sabstance 
termed  betidin  0,|H,oO„  m.p.  257*8*,  sablimes 
In  a  current  of  air,  readily  yields  an  anhydride  at 
130^,  and  is  tasteless  and  odourless.  It  does  not 
combine  with  acids  or  alkalis,  is  insoluble  in 
water,  sparingly  solnble  in  alcohol,  readily  in 
ether  and  turpentine. 

It  is  prepared  by  mixing  the  powdered 
epidermis  of  netula  a&a  with  1-8  p.0.  of  potas- 
sium nitrate,  pressing  the  mixture  into  amail 
tablets,  and  burning  them  in  closed  chambers 
without  flame,  and  with  the  introduction  of  a 
regulated  supply  of  air.  The  betulin  so  formed 
is  used  as  films  for  certain  substances  in  which 
it  acts  as  an  antiseptic,  as  a  protection  against 
damp  or  against  corrosive  acids  (Wheeler, 
Pharm.  J.  1899,  494). 

The  films  can  be  deposited  direct  on  various 
substances  by  allowing  the  vapours  to  play  upon 
them.  By  a  slight  modification  the  films  oap 
be  made  to  have  a  greater  or  less  degree  of 
transparency  and  porosity  (Wheeler,  Cbem. 
Zentr.  1900,  u.  798). 

According  to  Wheeler  (J.  Soc.  Chem.  Ind. 
1899,  606),  when  birch  bark  or  materials  made 
from  the  latter,  containing  betulin  are  heated 
in  a  closed  chamber  and  in  a  current  of  air, 
substances  termed  pyrdbtttdin  and  pvrobehdin 
anhydride  are  produced  in  forms  other  than  films. 

Oatdiherine  C]cHi,0.,H«0,  a  glucoside,  is 
obtained  by  extracting  the  bark  of  Betula  tenia 
with  alcoholic  lead  acetate,  precipitating  by 


BISMUTH, 


693 


eth«r,  and  reorystallifiing  from  alcohol.  The 
aqaeoos  solution  has  a  bitter  flavour,  is  levo- 
rotatory,  and  reduces  Fehling's  solution  when 
boiled.  It  is  hydrolysed  by  mineral  acids, 
bai^rta,  and  by  water  when  heated  to  130^-140*, 
givmg  a  sugar  and  methyl  salicylate  (Schaugans 
and  Gerooh,  Arch.  Pharm.  232,  437). 

A  gum  of  probable  formula  C4H«03  has  been 
isolated  from  American  birch  wood  {Betttla 
aiba)  (Johnson,  Amer.  Ghem.  J.  1896,  214). 

JBirchbark  oH  is  obtained  by  distilling  birch 
bark  {Bdula  cUba)  in  steam.  It  is  brown,  and 
has  a  similar  odour  to  birch  bud  oiL  On  cooling, 
crystalB  separate.  It  contains  palmitic  acid 
(Maensel,  Chem.  Zentr.  1907,  iL  1620;  Ziegel- 
mann,  Pharm.  Review,  1905,  23,  83). 

The  birch  bark  oil  prepared  from  the  bark  of 
Beiuia  aWa  by  Haensel  (Chem.  Zentr.  1908,  ii. 
1436),  had  8p.gr.  0-9003  at  20»  and  [a]p-12-08*; 
a  colourless  monocydio  sesquiterpene  was 
isolated  from  it,  having  b.p.  255^-256y744  mm., 
8p.gr.  0-8844  at  20*,  and  [a]„-0-6*.  The 
teipene  yields  a  hydrochloride,  sp.gr.  0-9753  at 
20*,  and  a  hydrocarbon,  b.p.  258'-260*/747  mm., 
and  sp.ffr.  0-8898  at  20^ 

Bircn  oil,  or  the  winteigreen  ofl  of  commerce, 
is  obtained  from  the  twigs  of  North  American 
birches,  especially  the  Bettda  lenta^  but  the  pure 
genuine  ou  is  prepared  from  OautOieria  pro- 
cumbens  (J.  8oo.  tlhem.  Ind.  Abstr.  1893,  174). 
It  consists  of  methylsalicylate,  a  hydrocarbon 
C.  gH,4,  and  small  quantities  of  benzoic  acid  and 
ethyl  alcohol  (Schroeter,  Amer.  J.  Pharm. 
Aug.  1889 ;  Trimble  and  Schroeter,  Pharm.  J. 
20,  166;  Ziegelmann,  2.C.). 

Oil  of  Qamheria  procwmbens  contains  99  p.c. 
methylsalicylate,  together  with  some  paiafiSn 
~CmH,,— probably  triacontane;  an  amehyde 
or  ketone;  a  secondary  alcohol  C,H,,0,  and 
an  ester  Ci4H,40„  and  is  lievo-rotatory,  sp.gr. 
1*180;  that  obtained  from  the  birch  contauis 
99*8  p.c.  methylsalicylate,  together  with  the 
above  constituents  except  the  alcohol  CgHigO, 
which  is  absent.  It  is  optically  inactive ;  sp.flT. 
1187  (Pharm.  J.  1895,  307,  328). 

Birch  hvd  oUiB  obtained  by  the  distillation 
of  birch  buds  with  steam.  It  is  yellow,  and  has 
a  pleasant  aromatic  odour.  Crystals  separate 
out  at  ordinary  temperatures,  and  ft  becomes 
whoUy  crystalline  at  — 46"  (J.  Soo.  Chem.  Ind. 
1903,  228).  It  is  soluble  in  alcohol  and  in  ether, 
but  not  in  alkalis,  carbon  disulphide,  or  glacial 
acetic  acid.  It  is  Uevo-rotatory,  its  rotation 
and  speoifio  gnvity  varying  with  different 
preparations.  That  obtamed  by  Sohimmel 
(Chem.  Zentr.  1909,  fl.  2156)  had  sp.ffr.  0-9730 
atWand«p-5*34'. 

It  contains  a  jMirafBn,  m.p.  50*,  an  esterg 
and  a  sesquiterpene  alcohol,  oeitUol,  probably 
^is^tsOH,  which  is  very  much  like  amyrol 
(obtained  from  sandalwood  oil),  has  a  bitter 
taste,  an  odour  like  incense,  b.p.  284*-288*/743 
mm.,  138M40*/4  mm.;  sp.gr.  0-975;  [a]p-35* 
(von  Soden  and  Elze,  Ber.  38,  1636 ;  Haensel, 
Chem.  Zentr.  1909,  ii.  1156.  Compare  also 
Pharm.  Zeit  47,  818 ;  Schimmel,  Chem.  Zentr. 
1905,  L  1340). 

The  leaves  of  BelvJa  alba  yield  an  olive-green 
oil,  which  is  solid  at  ordinary  temperature,  bu  t  fl  uid 
at  35°,  has  8p.gr.  0*9074  at  35^  and  is  optically 
inactive  (Haensel,  Chem.  Zentr.  1904,  u.  1737). 
Vol.  l.^T, 


Haensal  (Chem.  Zentr.  1908,  L  1837)  has 
isolated  a  crystalline  paraffin,  m.p.  49-5*-^**, 
from  the  oil  of  birch  leaves. 

According  to  Qrasser  and  Purkert  (Chem. 
Zentr.  1910,  i.  489),  products  C«iH7o07,C,pH,,0„ 
readily  soluble  in  water,  and  of  which  the 
potassium  salt  C^Hg^KtOy  can  be  used  thera- 
peutically as  a  diuretic,  can  be  obtained  by 
extracting  birch  leaves  with  alcohol,  treating 
the  warm  extract  with  potassium  hydroxide, 
and  then  saturating  the  solution  with  dry 
carbon  dioxide.  Water  is  now  added  and  the 
insoluble  products  filtered  off.  The  filtrate  is 
concentrated,  the  soluble  products  precipitated 
with  a  mineral  acid,  and  separated  from  one 
another  by  conversion  into  their  di-  and  tri- 
alkali  derivatives. 

Birch  juice  obtained  from  birch  trees  contains 
IsBvulose,  a  large  quantity  of  malates,  and 
basic  constituents.  When  fermented  with 
dextrose  and  milk  of  almonds,  it  forms  '  birch 
wine'  (Lenz,  Ber.  Deut.  Pharm.  Gee.  19,  332). 

BIRD-UME.  {Glu,  Fr. ;  VogeUeim,  Ger.) 
Bird-lime,  from  lUz  aquifolium  (Linn.),  was 
found  by  Personne  to  consist,  in  addition  to 
vegetable  dAris  and  water,  of  calcium  oxalate, 
caoutchouc,  and  ethereal  salts  of  a  solid  crystal- 
line substance,  iUeic  akohol  Gf^'R^fi,  OLp.  175% 
with  undetermined  fatty  acids. 

According  to  Divers  and  Kawakita,  Japanese 
bird-lime,  maide  from  I,  inteffra,  contains  ethereal 
salts  of  palmitic  acid,  and  in  Very  small  quantity 
a  semi-solid  acid,  the  calcium  salt  of  which  is 
soluble  in  ether  and  in  aloohoL  Japanese  bird- 
lime also  yields  two  very  similar  alcohols  by 
hvdrolvsis,  one  differing  only  sliehtly  from  ilicic 
alcohol,  and  termed  tlicylic  wcohol  CttH,.0, 
m.p.  172%  and  another  named  mochylic  aleMoi 
C,«&4.0,  m.p.  234%  from  mochi,  the  Japanese 
word  for  bird-lime. 

Caoutchouc  is  also  present  in  Japanese  bird- 
lime to  the  extent  of  about  6  p.c.,  but  only 
minute  quantities  of  oxalates.  Bv  distillation^ 
bird-lime  yields  much  palmitic  acid  and  a  thick 
oily  hydrocarbon  C,4H44  (Divers  and  Kawakita, 
Chem.  Soc.  Trans.  1888,  268). 

BIREBZ.  Persian  name  for  gum  galbanum 
(I>ymock.  Pharm.  J.  [3]  9,  1016). 

BISABOL  V.  Myrrh,  art.  Gttm  Rbstns. 

BISCINIOD.  Trade  name  for  a  combination 
of  cinchonidine  hydriodide  and  bismuth  iodide. 

BISDIAZONIUM  SALTS  v.  Diazo  com- 
pounds. 

BISMAL.  Bismuth  methylene  dip^allate  (v, 
BrsHCJTH,   Organic  compounds   of;  also  Syk- 

THBTIO   DBUOS). 

BISMARCK   BROWN  v.  Azo-    coloubiho 

BISMITE  or  BISMUTHOCHRE.  Native 
bismuth  oxide,  Bi,0„  occurring  as  a  yellow 
earthy  powder,  or  as  minute  rhombohedral 
scales.  Analysis  of  various  bismuth-ochres  from 
the  tourmaline  mines  of  San  Diego  Co.,  Cali- 
fornia, show  these  to  be  either  bismuth  hydroxide, 
Bi(OH)„  or  pucherite,  BiV04,  or  mixtures  of 
these ;  and  ooubt  has  been  expressed  as  to  the 
occurrence  of  the  pure  oxide  BigO*  in  nature 
(W.  T.  SchaUer,  1911).  L.  J.  8. 

BISMON  V.  Synthetic  Deuos. 

BISMUTH.  Bismuth,  {Etain  de  glace,  Fr. ; 
Wiamuth,  Ger.)  Symbol  Bi.  At.  wt.  208-5 
(De  Coninck  and  Q^rard^- 

2  q 


504 


BISMUTH. 


Occurrence. — ^Metallio  bismuth  occurs  in 
small  quantities  in  widely  distributed  localities, 
usually  with  other  ores,  such  as  those  of  cobalt, 
nickel,  copper,  silver,  lead,  and  tin.  It  is  found 
massiye,  eranulated,  reticulated  or  arborescent, 
associated  with  arsenic  and  silver,  and  occasion- 
ally iron. 

The  principal  sources  are  Bolivia,  South 
Australia,  Altenberg,  Schneeberg,  Annaberg, 
Marienbeig,  Joachimsthal,  Johannffeoigenstadt, 
Lolling  in  Carinthia,  Fahlun,  Sweden,  and  New 
South  Wales.  In  small  quantities  it  occurs  at 
Huel  Spamon,  Cornwall,  Carrick  Fells,  Alva, 
Stirlingshire.  Alloyed  with  64  p.c.  sold  it 
occurs  at  Maldon,  Victoria.  Alloyed  with 
tellurium  it  occurs  as  ietradymite  in  Cumberland. 
An  alloy  of  bismuth  with  3  p.o.  arsenic  occurs  at 
Palmbaum  near  Marienbeig. 

Bismuth  sulphide  is  widely  distributed  in 
small  quantities,  being  found  in  Saxony,  Sweden, 
South  Australia,  America,  and  Cumberland.  A 
sulphide  of  bismuth,  copper,  and  lead  occurs  as 
needle  ore,  acictUite  or  jnUrinite. 

As  oxide,  or  hiamulh  ochre,  it  is  found  as  a 
yellow  substance,  frequently  as  a  coating  on 
other  minerals,  associated  with  iron  and  other 
impurities,  at  Schneeberg,  Joachimsthal,  Beresof 
in  Siberia,  and  in  New  South  Wales.  The  prin- 
cipal ore  in  Bolivia,  which  is  stated  by  Domeyko 
to  be  the  richest  country  in  bismuth,  is  a  compact 
earthy  hydrated  oxide. 

Bismuth  occurs  as  carbonate  or  hiemvihiie, 
usually  containing  carbonates  of  iron  and  copper, 
at  Meymac,  with  antimony,  arsenic,  lead,  iron, 
and  lime ;  in  Mexico,  whence  it  is  imported  to 
this  country ;  in  North  Carolina,  and  other 
localities.  Of  late  years  considerable  deposits 
of  bismuth  ores  have  been  found  in  many  places 
in  America,  but  they  have  been  very  littie 
worked. 

Extraction. — At  Schneebexg  in  Saxony  the 
ore  worked  is  principally  metallic  bismuth  occur- 
ring in  ores  wnich  contain  silver,  lead,  tin,  and 
arsenic  in  gneiss  and  clay-slate. 

The  ore,  which  contains  from  7  to  12  p.c. 
bismuth,  is  sorted  by  hand  as  far  as  possible  from 
the  gangne  before  treatment.  The  old  method 
of  liqtuUion  or  *  sweating '  is  still  used,  but  has 
now  been  lareely  supenMed  bv  smelting  pro- 
cesses, in  whicn  the  metal  is  much  more  penectiy 
extracted. 

Liquation.^  In  this  process  the  metal  is 
separated  as  far  as  possible  from  the  gangue  by 
melting  at  a  low  temperature.  The  picked  ore 
is  broken  into  pieces  as  large  as  a  hazel  nut,  and 
placed  in  inclined  iron  tubes  in  charges  of  about 
12  owts.,  sufficient  space  being  left  in  the  tube  for 
stirrinff  the  ore  from  the  upper  end  (Figs.  1,  2,  3). 
The  tubes  are  closed  at  the  upper  ends  by  plates 
of  iron,  and  at  the  lower  ends  by  similar  plates 
containing  circular  apertures  through  whicn  the 
molten  metal  may  run.  The  ends  of  the  tubes 
project  slightiy  beyond  the  wall3  of  the  furnace, 
the  upper  over  a  tank  and  the  lower  ends  over 
iron  crucibles  which  contain  powdered  charcoal, 
and  which  are  gently  heated  from  below  by  a 
small  charcoal  nimace.  The  tubes  are  heated 
so  as  to  cause  the  metal  to  flow  easily,  and  in 
about  10  minutes  the  bismuth  commences  to 
pass  out  into  the  crucibles,  being  there  covered 
by  the  charcoal  and  thus  protected  from  oxida- 
tion.   The  ore  is  occasionally  stirred  with  an 


iron  rod  from  the  upper  end,  and  in  from  30 
to  60  minutes  the  operation  is  completed. 
The  residues,  graupen  or  bismuth  hadeif,  axe 
raked  from  the  upper  end  into  the  tsAk,  and  at 
once  replaced  by  fresh  ore.  In  this  manner  only 
about  two-thirds  of  the  bismuth  is  extraoted. 
20  cwts.  of  ore  require  63  cubic  feet  of  wood. 
The  contents  of  the  pots  are  removed  by  ladles 
to  moulds  and  cast  mto  ingots  of  25  to  60  lbs. 
weight. 

Sulphurous  ores  are  usually  roasted  to  re 
move  sulphur,  and  then  smelted  with  iron 
(to  remove  the  last  traces  of  sulphur),  carbon, 
slag,  sodium  carbonate,  limestone,  and  some- 
timea  fluor-spar.  The  regulus  of  bismuth  thus 
obtained  is  fused 
on  an  inclined  iron 
plate  and  run  down, 
leaving  a  dross  con* 
tainin^  much  of  the 
impurity.  Bismuth 
ores  are  sent  from 
Joachimsthal,  and 
worked  by  this  pro- 
cess at  Schncebeig. 

The  following 
analyses  of  two 
tvpical  samples 
show  the  composi- 
tion of  commercial 
bismuth :  From 
Saxony — Bismuth, ' 
09*77  p.c. ;  copper,  0*08 ;  silver,  0-05 ;  sulphur, 
0*10;  iron,  trace.  Fh>m  Joachimsthal — Bismuth, 
99*32  p.c.;  lead,  0*30;  silver,  0*38;  iron  and 
copper,  tracts;  sulptiur,  none. 

At  Joachimsthal  a  method  devised  by  R. 


Fio.  1. 


®o/ao® 


Fio.  2. 

Vogel  is  used  (DingL  poly.  J.  167, 187)  for  extract- 
ing bismuth  from  ores  free  from  lead.  The 
ores,  which  usually  contain  from  10  to  30  pia 
bismuth,  are  mixed,  according  to  their  riohneas, 
with  23  to  30  p.o.  iron  turnings,  15  to  60  p.o. 
sodium  carbonate  (according  ic  the  amount  of 
gangue  present),  5  {kc.  lime,  aad  5  p.o.  fluor- 

rThe  mixture  is  introduced  in  charges  of 
it  1  cwt.  into  day  crucibles,  23  inches  high 
and  16  inches  wide  at  the  month,  covered  and 
heated  in  a  wind  furnace  to  tranquil  fusion,  and 
poured  into  conical  moulds.  The  liquid  sepa- 
rates into  three 
layers,  the  upper 
consisting  of  slag,  the 
second  of  a  speiss 
containing  the  arse- 
nic, sulphur,  nicked, 
cobalt,  and  iron,  and 
most  of  the  other 
impurities,  with 
about  2  p.c.  of  bis- 
muth, and  the  lower 


Fio.  3. 


consisting  of  a  re^us  of  nearly  pui«  bismutlL 
The  metal  is  again  fused  and  remoulded  (see 
Kerl,  Handb.  der  Met.  Hflttenkunde). 


BISMUTH. 


695 


A  rimilftr  prooeas  haa  Iseen  adopted  by  Patera 
(J.  1862,  646)  for  the  extraction  ol  biBmath  from 
refinery  residues. 

In  Franoe  the  carbonate  of  bismuth  imported 
from  Meymac  is  dissolved  in  the  minimnm 
quantity  of  hydrochloric  acid  and  pieces  of  iron 
insertea  in  the  slightly  acid  liquid.  The  bismuth 
is  thus  precipitated  as  a  black  powder,  which  is 
well  washed  and  fused  in  a  plumbago  crucible 
mider  a  layer  of  charcoal  at  as  low  a  texnpera- 
ture  as  possible  (Ad.  Camot,  Ann.  Chem.  rhys. 
[5]  1,  406  ;  and  Bull.  Soc.  chim.  21,  114). 

Ores  of  bismuth  averaging  60  p.c.  bismuth  are 
imported  into  England,  principally  from  Ade- 
laide, South  Australia,  and  from  Mexico.  They 
are  usually,  fused  in  plumbago  pots  with  borax, 
sodium  carbonate,  and  a  little  crude  tartar. 

For  the  extraction  of  bismuth  for  pharma- 
ceutical purposes  from  sulphurous  ores,  Valen- 
ciennes roasts  the  ore  on  the  level  bed  of  a 
reverberatory  furnace  for  24  hours  with  the 
occasional  addition  of  charcoal  and  frequent 
stirring  with  an  iron  rabble.  When  the  sulphur 
has  thus  been  evolved,  the  ore  is  mixed  with 
about  30  p.c.  charcoal,  and  a  mixture  of  chalk, 
salt,  and  fluor-spar,  and  again  fused  in  a  rever- 
beratory furnace.  From  5  to  8  p.  c.  of  the  bis- 
muth is  lost  by  this  process,  but  this  is  compen- 
sated by  the  extra  purity  of  the  product.  By 
sufcoequent  fusion  with  nitre,  the  antimony, 
arsenic,  and  sulphur  are  removed,  and  by  the 
ordinary  wet  methods  the  lead,  copper,  and 
silver  are  eliminated  (M.  A.  Valenciennes,  Ann. 
Chim.  Phys.  [6]  1,  397).    • 

H.  Tamm  (Chem.  News,  25,  86)  states  that 
bismuth  can  be  SCT>arated  from  ores  containing 
much  copper  by  fusion  with  an  alkaline  flux 
containing  free  sulphur,  in  which  case  the  copper 
remains  imreducedL  He  recommends  a  mixture 
of  6  parts  sodium  carbonate,  2  salt,  1  sulphur,  1 
carbon,  to  be  mixed  in  about  equal  proportions 
with  the  ore.  The  bismuth  produced  is  stated 
to  be  much  more  free  than  usual  from  arsenic, 
antimony,  and  lead,  but  about  8  p.c.  of  the  total 
bismuth  is  lost. 

The  bismuth  present  in  small  quantities  in 
lead,  copper,  and  silver  ores  frequently  becomes 
concentrated  in  the  secondary  products  of  the 
metallurgical  processes  and  may  then  be  profit- 
ably extractea.  In  the  oxidation  of  silver-lead 
oontaininff  bismuth,  the  lead  oxidises  much  more 
rapidly  tEian  the  bismuth,  and  at  the  close  of 
the  cupe^tion  a  blackish  litharge  rich  in  bis- 
muth IS  obtained,  from  which  thftt  metal  may 
be  extracted  by  further  concentration  and  acid 
treatment  (J.  12,  711).  In  this  manner  bismuth 
becomes  concentrated  in  the  blick«ilber  in  the 
treatment  of  silver  ores  at  Freiberff,  and  passes 
into  the  hearth  bottoms,  as  much  as  25  p.c. 
being  sometimes  so  absorbed.  When  the  hearths 
contain  sufficient  bismuth  to  be  profitably 
extracted,  they  are  finely  ground  and  treated 
with  hydrochloric  acid,  with  the  formation  of 
bismuth  chloride.  Water  is  added  to  the 
solution  to  precipitate  the  metal  as  oxychloride, 
and  the  precipitate  is  collected,  washed,  dried, 
and  reduced  to  metal  by  fusion  with  charcoal, 
sodium  carbonate,  and  powdered  glass  {v. 
Phillips's  Metallurgy). 

S^eral  proposals  have  been  made  for  the 
extraction  of  bismuth  by  wet  methods.  Becker 
(Fr.  Pat.  366439,  19Q6)  suggests  the  treatment 


of  sulphide  ores  with  a  solution  of  an  alkali  or 
alkaline  earth  hyposulphite.  The  solution  thus 
obtained  is  treated  with  alkali  sulphides,  and 
the  resulting  precipitate  of  bismuth  sulphide  is 
dried  and  smelted  as  described  above. 

Both  Becker  (ibid,)  and  Ranald  (Eng.  Pat. 
16622,  1898)  have  patented  the  use  of  a  solution 
of  ferric  chloride  as  a  solvent  for  bismuth 
sulphide  and  the  subsequent  precipitation  of 
metallic  bismuth  from  the  solution  by  means 
of  iron  or  zinc,  or  by  electrolysis. 

Eulert  (Rev.  Prod.  Chim.  4,  164)  employs  a 
mixture  of  sulphuric  acid,  water,  common  salt, 
and  potassium  nitrate  as  the  extracting  liquor, 
and  the  process  can  be  made  continuous.  The 
bismuth  is  finally  obtained  as  the  oxychloride, 
which  can  be  sold  or  smelted  for  the  metal. 

On  the  extraction  of  bismuth  from  its  ores,  v. 
also  Winckler  (Ber.  Entwick.  Chem.  Ind.  1, 953). 

Purification, — ^The  crude  bismuth  produced 
by  the  above  methods  contains  a  variety  of 
impurities,  from  which  it  is  important  in  many 
cases  to  separate  it.  These  impurities  are  sul- 
phur, arsenic,  antimony,  copper,  nickel,  cobalt, 
silver,  gold,  lead,  and  iron. 

Sulphur  and  arsenic  may  be  removed  by 
fusion  with  ^  of  its  weight  of  potassium  nitrate, 
with  constant  stirring  at  a  temperature  slightly 
above  the  temperature  of  fusion ;  the  nitre 
soon  oxidises  the  impurities  and  a  little  of  the 
bismuth,  forming  with  them  a  slag  which  rises 
and  solidifies  at  the  surface.  For  the  complete 
removal  of  these  impurities  a  second  fusion  is 
frequently  necessary. 

C.  M^hu  (Pharm.  J.  [3]  4,  341)  recommends 
the  following  process  for  the  removal  of  sulphur 
and  arsenic.  The  metal  is  heated  considerably 
above  the  melting-point  in  a  vessel  so  as  to 
expose  a  large  sur»ce,  and  the  oxide  is  removed 
to  the  sides  as  fast  as  it  forms  until  about  one- 
fourth  of  the  metal  has  become  oxidised ;  the 
Cter  part  of  the  sulphur  and  arsenic  will  then 
>  passed  off  as  oxides.  The  mass  is  cooled, 
pulverised,  and  mixed  with  chareoal,  dried  soap, 
and  potassium  carbonate  (free  from  sulphate), 
about  one-fourth  of  the  original  weight  of  Uie 
metal,  in  a  crucible,  covered  with  charcoal,  and 
heated  to  redness  for  one  hour.  Arsenic  may 
also  be  mostly  removed  by  fusion  for  a  consider- 
able time  under  a  layer  of  charcoal.  Arsenic, 
sulphur,  and  most  <rf  the  antimony  may  be 
eliminated  by  fusion  at  a  bright-red  heat  under 
borax,  starring  witb  a  rod  of  iron  until  the  action 
ceases.  The  iron  combines  with  the  impurities 
and  rises  as  a  difficultly  fusible  sUg  to  the  surface 
from  beneath  which  the  still  liquid  metal  may 
be  poured  after  partial  cooling. 

For  the  complete  removal  of  antimony,  2  or 
3  parts  of  bismuth  oxide  for  each  part  of  anti- 
mony supposed  present  are  fused  with  the 
metal,  ^e  oxide  of  bismuth  then  gives  up  its 
oxygen  to  the  antimony,  becoming  itsislf  reduced 
and  the  antim<»iious  oxide  floats  on  the  surface. 

^ugo  Tamm  (Chem.  News,  25,  85)  recom- 
mends for  the  removal  of  copper  the  fusion  oi 
the  metal  at  a  low  temperature  under  1  part  of  s 
mixture  of  8  potassium  cyanide  and  3  sulphur. 
When  the  action  has  ceased  the  mass  is  stirred 
with  a  clay  (not  iron)  rod,  cooled  until  the  flux 
has  set,  and  the  metal  poured  out  from  beneath. 
If  impure  cyanide  is  used,  a  relatively  larger 
quantity  is  required. 


596 


BISMUTH. 


Iron  may  be  completely  removed,  according 
to  H.  Tfirach  (J.  pr  (Jhem.  [2]  14,309),  byfoaioo 
under  a  layer  of  potassium  chlorate  containing 
from  2  to  5  p.a  sodium  carbonate. 

From  sHver  bismuth  may  be  separated  by 
oupellation  and  subsequent  reduction  of  the 
bismuth  oxide  so  produced,  or  the  metal  may  be 
dissolved  in  nitric  acid,  the  silver  precipitated 
with  hydrochloric  acid,  the  solution  nltered,  and 
the  basic  salt  of  bismuth  precipitated  by  excess 
of  water,  and  reduced  to  metal. 

Silver  can  be  partially  removed  from  bismuth 
by  a  process  resembling  Pattinson's  process  for 
lead  (Schneider,  J.  pr.  Chem.  [2]  23,  75). 

Jjead  may  be  precipitated  from  a  nitric  acid 
solution  of  tne  metal  by  the  addition  of  sulphuric 
acid,  and  the  bismuth  recovered  as  already 
described.  A  method  commonly  used  is  to 
fuse  the  impure  metal  with  bismuth  oxychloride, 
from  which  the  lead  liberates  bismuth,  itself 
becoifaing  combined  with  oxygen  and  chlorine. 

A  number  of  investigations  on  the  refining 
of  bismuth  have  been  conducted  by  E.  Matthey, 
and  the  methods  he  proposes  are  given  separately 
bolow,  inasmuch  as  they  possess  the  merit  of 
simplicity  and  have  been  thoroughly  tested  on  a 
large  scale. 

Arsenic  is  removed  completely  by  maintain- 
ing molten  bismuth  at  a  temperature  of  510^- 
520^  for  some  time.  There  is  only  a  very 
slight  loss  due  to  oxidation  (E.  Matthey,  CSiem. 
News,  67,  63). 

Antimony  is  separated  by  melting  the  metal 
and  maintaining  the  temperature  at  350*. 
An  alloy  of  bismuth  and  antimony,  containing 
over  30  p.o.  of  the  latter,  rises  to  the  surface  of 
the  metal,  givine  it  an  *  oily '  appearance,  and 
can  be  ddmmea  off.  A  complete  removal  of 
the  antimony  is  thus  effected  (£.  Matthey,  l.e.). 

Copper,  For  the  separation  of  copper  from 
bismuth  which  has  been  previously  freed  from 
arsenic,  antimony,  lead,  &c.,  E.  Matthey 
(Roy.  Soo.  Proc.  43,  172)  recommends  its  fusion 
with  bismuth  sulphide.  The  pure  metal  ob- 
tained amounts  to  90  p.o.  of  the  crude  material, 
while  the  remaining  bismuth  sulphide,  containing 
oopper  sulphide,  may  be  resmelted. 

Alkali  solphides  may  be  substituted  for  the 
bismuth  sulphide  in  the  above  operation  (E. 
Matthey,  Proc.  Boy..Soc.  49,  78). 

Lead  may  be  separated  from  the  fused  metal 
by  repeated  crystallisations,  the  alloy  of  bismuth 
and  lead  melting  at  lower  temperatures  than  the 
purer  bismutlL  E.  Bfatthey  has  thus  by  four 
crystallisations  reduced  the  percentage  of  lead 
from  12  to  0*4  p.c.  (Proc.  Boy.  Soc.  42,  93). 

For  the  separation  of  geld  and  silver,  E. 
Matthey  (Proc.  Boy.  Soc.  42, 89, 94)  recommends 
the  addition  of  2  p.c.  zinc  to  the  molten  metal 
The  mass  is  fionduaUy  cooled  and  the  surface  crust 
removed.  This  operation  is  repeated,  whereby 
the  whole  of  the  precious  metals  are  concen- 
trated in  the  skimmings.  On  fusing  these  in  a 
crucible  with  borax,  the  gold  and  silver  are  freed 
from  impurities  by  the  action  of  the  oxide  of 
bismuth,  and  sink  to  the  bottom.  To  separate 
the  last  traces  of  these  metals  from  the  slag,  it  is 
again  fused  with  bismuth. 

A.  Mohr  states  (Elektrochem.  u.  Met.  Ind. 
1907,  5,  314)  that  an  electrolytic  method  has 
been  used  with  success  for  the  purification  of  a 
Mexican  lead-bismuth  alloy  containing  81*1  p.a 


lead  and  14*5  p.o.  bismuth,  together  with  small 
amounts  of  antimony,  iron,  sine,  arsenic,  nlver, 
and  gold.  First  the  metal  is  made  the  anode 
in  an  electrolyte  containing  6  p:c.  lead  fluo- 
silicate  and  14  p.c.  hydroflnoolioic  add.  IRie 
lead  is  deposited  on  a  cathode  of  pure  lead, 
and  contains  only  0*01  p.c.  bismuth.  The  anode 
slimes  are  fused  with  sodium  hydroxide  and 
carbontfte,  and  the  metal,  containing  94  p.a 
bismuth,  cast  into  anodes,  which  are  then  used 
in  a  second  electrolysis,  using  a  solution  of  bis- 
muth chloride  (about  10  p.c.)  and  free  hyd^ 
chloric  acid  (about  10  p.c. ).  The  cathodes  are  of 
Acheson  graphite,  and  are  i>laced  on  the  floor  of 
the  cell.  The  current  used  is  20  amp.  per  sq.  ft. 
at  the  cathode,  and  60  amp.  per  sq.  ft.  at  the 
anode,  with  a  P.  D.  at  the  terminals  of  1*2  volt& 
The  resulting  bismuth  is  99*8  p.c.  pure,  the 
remaining  0*2  p.c.  consisting  chiefly  of  silver. 
{See  also  Zahorski,  Hurter  and  Brock,  Etag. 
Pat.  22251,  1895.) 

ChemieaUy  pure  bismuth  is  best  prepared  by 
dissolving  the  commercial  metal  in  nitric  aoid, 
decanting  from  any  residue,  and  adding  excess 
of  water,  whereby  the  bismuth  is  precipitated  as 
basic  nitrate,  leaving  the  impurities  in  solutioD. 
The  precipitate  is  well  washed  by  decantatka, 
dried,  mixed  with  black  flux  or  other  i«duoins 
agent  which  produces  a  readily  fusible  flux,  ana 
r^uced  at  a  gentle  heat  in  a  crucible. 

Properties, — Bismuth    is    a    greyish  -  white 
crystalline  metal  of  distinctly  red  tinge  when 
compared  with  whiter  metals  such  as  sine  or 
antimony.     It  is  very  brittle  and  easily  pow- 
dered, and  a  bad  conductor  of  heat  and  eleo- 
tricity.     Its  tenacity  is  very  small,  a  rod  2  mm. 
in  diameter  will  just  support  a  weight  of  14*19 
kilos.  (Muschenbroeck).    It  forms   fine  obtuse 
rhombohedral   crystals,   which   approach   very 
closely  to  the  form  of  cubes.    It  nas  also  been 
obtained  in  the  form  of  aoicular  needles,  which 
are  really  eloncated  hexagonal  prisms  (Heberdey, 
Ber.  Akad.  Wien.  104,  L  254i    Bismuth  mdts 
at  27r  (Mylius  and  Groschuff).  and  boils  at  a 
temperature    between    the    melting-point    of 
copper  and  nickel,  i.e.  between  1084^  and  1450° 
(Camelley  and  Carlton  Williams),  condemang 
in  lamina.    The  vapour  density  at  temperatures 
between  1600''  and  1700°  is  11,  which  corre- 
sponds to  that  calculated  for  a  mixture  of  mon- 
atomic   and   diatomic   molecules  (Meyer,  Ber. 
1889,   22,    726).     Its  sp.gr.    at    12°   is   9*823. 
W.  Spring  has  shown  tnat  by  the  exposure  of 
bismuth  of  density  9 '804  to  a  pressure  of  20,000 
atmospheres,  the  density  was  raised  to  9*856; 
a  second  compression  still  further  increased  the 
density  to  9*863  (Ber.  16,  2724).     It  is  stoted 
that  by  careful  hammering  its  density  may  be 
raised  to  9*88. 

Bismuth  expands  in  cooling.  Tribe  (Chem. 
Soc.  Trans.)  has  shown  that  this  expansion  does 
not  take  place  until  after  solidification. 

According  to  Cohen  and  Moesveld,  bismuth 
exists  in  two  enantiotropic  modifications,  the 
transition  temperature  being  75°/760  mm.  The 
transformation  of  the  form  stable  below  tliis 
temperature  (a)  into  the  other  modification  (3) 
is  accompanied  by  considerable  increase  in 
volume.  The  3- variety  can  exist  in  the  meta- 
stable  condition  below  the  transition  point. 

Exposed  to  dry  air,  bismuth  remains  nn- 
alterea  at  the  ordinary  temnerature,  bat  in  moist 


BISMUTH. 


597 


air  or  in  contact  with  water  it  becomee  coated 
with  oxide.  When  heated  in  air  it  bums  with  a 
blnish  flame^  evolving  yellowish  fumes  of  oxide. 
At  hiffh  temperatures  it  decomposes  water. 

Ccud  sulphuric  acid  has  no  action,  but  the 
hot  concentrated  acid  dissolves  bismuth.  Hydro- 
chloric acid  acts  but  slowly,  and  Ditte  and 
Metzner  have  shown  (Compt.  rend.  115,  1303) 
that  this  action  can  only  take  place  in  presence  of 
oxygen.  Nitric  acid,  dilute  or  strong,  dissolves 
it  r^Miily,  with  the  formation  of  nitnte.  Pow- 
dered bismuth  thrown  into  chlorine  gas  ignites 
with  the  formation  of  trichloride.  It  also  unites 
directly  with  bromine,  iodine,  and  sulphur. 

When  comparatively  pure,  bismuth  dystal- 
lises  readily.  To  obtain  it  in  the  form  of  fine 
cxystals  it  is  melted  and  allowed  to  cool  until  a 
orust  has  formed;  the  crust  is  pierced  on 
opposite  sides  with  a  hot  iron,  and  the  still  liquid 
potion  poured  through  one  of  the  ox>enin£8. 
On  careful  removal  of  the  crust  the  sides  of  the 
vessel  are  found  covered  with  crystals,  frequently 
resembling  hollow  pyramidal  cubes  hk»  those  of 
salt,  but  wnicb  are  m  reality  obtuse  rhombohedra. 
Their  iridescent  lustre  ib  due  to  a  veiy  thin 
film  of  oxide  which  shows  the  colour  character- 
istic of  thin  plates. 

Bismuth  can  be  obtained  in  the  colloidal 
state  by  reducing  a  solution  of  the  nitrate  with 
stannous  chlori<M»  or  by  the  action  of  hypo- 
phosphorus  acid  on  bismuth  oxychloride(Gutbier 
and  Mofmeyer,  Zeitsch.  anoig.  Chem.  44,  225). 

Bismuth  is  the  most  diamagnetic  substance 
known,  a  bar  of  the  metal  placing  itself  equa- 
torially  between  the  poles  of  a  magnet,  t.e.  at 
right  angles  to  the  position  taken  up  oy  a  bar  of 
iron.  Bismuth  also  occupies  an  extreme  place 
in  the  thermo-electric  series,  being  used  with 
antimony  in  the  preparation  of  the  most  delicate 
thermopiles. 

Analysis. — ^All  compounds  of  bismuth,  when 
mixed  with  carbon  or  other  reducing  agent  and 
fused  before  the  blowpipe,  ^ve  a  orittU  white 
bead  of  metal  and  a  yellow  morustation  on  the 
charcoal,  darker  than  that  of  oxide  of  lead. 

A  very  good  di^  test  for  bismuth  is  that  due 
to  von  KooelL  The  substance  is  heated  on 
charcoal  with  a  mixture  of  potassium  iodide  and 
sulphur,  when,  if  bismuth  is  present,  a  brilliant 
scarlet  incrustation  ib  obtained. 

Salts  of  bismuth  in  solution  give,  on  addition 
of  excess  of  water,  a  white  precipitate  of  basic 
salth  which  is  insoluble  in  tartaric  acid,  and 
blackens  with  sulphuretted  hydrogen  (distinction 
from  antimony). 

Metallic  iron,  copper,  lead,  and  tin  precipitate 
metallio  bismuth  from  solutions. 

A  qualitative  test  for  bismuth  proposed  by 
Beichard  (GheuL  Zeit.  28,  1024)  is  the  addition 
of  a  brudne  salt,  or,  better,  brucine  itself  to  the 
solution.  In  presence  of  bismuth  a  deep-red 
colour  ii  produced  which  is  distinguished  horn 
that  given  by  nitric  acid  by  the  fact  that  it 
becomes  deeper  on  heating,  whereas  the  colour 
given  by  nitric  acid  turns  to  yellow. 

Estimaium, — ^Bismuth  may  be  separated  from 
copper,  cadmium*  mercury,  and  silver,  lead 
having  been  removed  previously  by  precipita- 
tion as  sulphate,  by  the  following  method,  due 
to  St&hler  and  Schaxfenberg  (Ber.  38,  3862). 

The  solution*  which  may  contain  hydrochloric 
acid,  and  should  contain  about  0*m)*2  gram 


of  bismuth,  is  diluted  to  300-400  cc,  and  any 
precipitate  redissolved  by  the  cautious  addition 
of  nitric  acid.  Tins  solution  is  heated  to  boiling, 
and  treated  with  a  boiling  10  p.c.  solution  of 
trisodium  phosphate  Na,P04  ^obtained  by 
mixing  equivalent  amounts  of  sodium  hydrogen 
phosphate  and  caustic  soda).  In  presence  of 
much  hydrochloric  acid,  a  considerable  excess  of 
the  phosphate  must,  be  used,  but,  should  the 
solution  oeoome  alkaline,  nitric  acid  must  be 
added.  After  boilins  the  whole  for  some  time, 
the  precipitate  ia  allowed  to  settle,  and  the 
supernatant  liquid  is  tested  with  sodium  phos- 
phate. If  precipitation  is  complete,  the  pro- 
cipitate  ia  collected  hot  on  a  Gooch  crucible, 
washed  with  1  p.c.  nitric  acid,  containing 
ammonium  nitrate,  dried  at  120*,  and  finally 
heated  over  a  bunsen  burner,  and  weighed  as 
bismuth  phosphate  BiP04.  The  precipitate 
is  venr  hygroscopic :  suitable  precautions  must 
theretore  m  taken  in  weighing  it. 

A  modification  of  this  method,  which  renders 
it  suitable  for  the  separation  of  bismuth  from 
considerable  amounts  of  merouxy,  has  been 
described  by  Stabler  (Ghem.  Zeit.  31,  615). 

A  volumetric  method  for  the  estimation  of 
bismuth,  for  which  considerable  accuracy  is 
claimed,  is  the  chromate  method  of  Lowe  as 
modified  by  Rupp  and  Schaumann  (J.  Soc.  C9iem* 
Ind.  1002,  1558). 

H.  W.  Rowell  has  published  a  method  (J.  Soc. 
CSiem.  Ind.  1908,  102)  for  the  estimation  of 
small  quantities  of  bismuth  in  ores,  &o.  The 
methoa  is  colorimetric,  depending  on  the 
yellow  colour  produced  when  potassium  iodide 
is  added  to  a  solution  of  the  bismuth  compound 
in  sulphuric  acid  {see  also  Eng.  and  Mining 
Jour.  1901,  459). 

An  account  of  other  methods  used  for  the 
estimation  of  bismuth  will  be  found  in  the 
article  on  Analysis. 

For  the  dry  assay  of  bismuth  ores  the  fluxes 
used  must  depend  on  the  composition  of  the 
ore.  Thus  witn  ores  containing  metallic  bismuth 
or  that  metal  as  oxide,  sulphide,  carbonate,  &c., 
a  flux  consisting  of  a  mixture  of  2  parts  potassium 
or  sodium  carbonate,  1  part  sodium  chloride,  and 
a  proper  quantity  of  ftrgol  or  potassium  cyanide 
or  charcoal  powder,  will  oe  useful  (Tamm) ;  with 
the  addition,  where  much  earthy  matter  is 
present,  of  borax.  Where  much  copper  is 
present,  Tamm  advises  the  use  of  one  part  of  the 
ore  mixed  with  one  part  or  less  of  a  mixture  of 
sodium  carbonate  1,  salt  2,  sulphur  2,  charcoal 
powder  1  part.  The  exact  proportions  in  which 
these  fluxes  are  most  useful  must  be  learned  by 
experience. 

Alloys  of  Bismuth. 

Bismuth  unites  readilv  with  most  metals, 
forming  alloys  which,  witn  few  exceptions,  are 
not  of  commercial  importance. 

Tin  and  Lead.  Tne  alloys  of  bismuth  with 
these  two  metals  are  of  special  interest.  They  are 
extremely  fusible,  and  on  account  of  their  expan- 
sion on  cooling  they  tdke  a  very  fine  impression, 
being  laively  used  for  electrotype  moulds,  &c. 

An  alby  of  1  bismuth,  2  tin,  1  lead  is  used  as 
a  soft  solder  by  pewterars,  sjid  for  the  cake 
moulds  for  toilet  soap.  An  expensive  but  effeo 
tive  alloy  for  stereotype  cliche  and  metallic 
writing  pencils  contains  5  biamutbi  2  ^  ^  l^^d ; 
ttmeltsat9^66^ 


•99B 


BISMUTH. 


A  thorough  phyaioo-chemical  investiffation 
of  these  ternary  alloys  has  been  mtuae  hy 
Chaipy  (Compt.  rend.  126,  1569),  whose  memoir 
should  be  consulted  for  details.  He  finds  that 
the  eatectic  mixture  contains  32  p.c.  lead,  16  p.c. 
tin,  and  62  p.c.  bismuth;  and  has  m.p.  96°. 
Such  alloys  are  used  to  a  considerable  extent  in 


aatomalM 


safety   plugs    for    boilers   and   for 
sprinklers. 

The  varieties  of  fusible  meial  contain  these 
three  metab,  with  the  addition  sometimes  <rf 
nA/lmiiim^  wMch  Still  further  lowers  the  melting- 
point.  A  table  of  the  most  important  of  these 
alloys  is  given  below : 


Name  of  alloy 


Newton's        • 
Rose's    . 
D*Arcet's 
liohtenberg's  . 
Wood's  .         . 

Lipowitz's 
Guthrie's  *  Eutectic ' 


Bismuth 

Load 

Tin 

50 

31-25 

18-75 

50 

2810 

241 

50 

25  0 

250 

50 

30-0 

20-0 

50 

26-0 

12-5 

50 

26-9 

12-78 

50 

20-55 

21-10 

Cadmium 


12-5 
10-4 
14-03 


Temperature  of 
maximum  density 


55°  (Spring) 


25''  (Spring) 
38-5*'(    „    ) 


The  action  of  heat  on  fusible  metal  is  some- 
what  anomalous.  Taking  Lipowitz's  alloy  as  a 
tvpical  example,  we  find  (from  Spring's  table  of 
densitieB  at  different  temperatures)  that  this 
alloy  whilst  cooling  contracts  very  rapidly  at 
the  solidifying  pomt  (65°),  contracts  slowly 
from  that  temperature  to  38-5°,  expands  thence 
to  about  25°,  and  again  contracts,  occupying 
at  0°  the  same  volume  as  at  46°. 

For  this  reason,  in  taking  a  cast  or  impression 
with  fusible  metal,  it  is  advisable  to  allow  the 
alloy  to  cool  to  a  pasty  mass  before  placing  in 
the  mould  {v.  lurther,  Godefroy,  Fremy's 
Encvcl.  Chimique,  art.  '  Bismuth,'  1888,  24-30). 

Mercury  dissolves  a  considerable  amount  of 
bismuth  without  solidifying.  The  amalgam  con- 
taining 1  bismuth  and  4  mercury  adheres 
stronffly  to  smooth  surfaces  such  as  glass.  One 
partbismuth  and  2  parts  mercury  forms  a  pastv 
amalgam.  The  alloy  consisting  of  D'Aroets 
alloy  and  mercury,  for  which  250  parts  of  mercurv 
are  used  for  100  parts  of  D'Arcers  allov,  is  used, 
on  account  of  its  low  melting-point,  for  taking 
casts  of  anatomical  preparations.  The  alloy 
is  introduced  in  the  liquid  state,  allowed  to 
solidifv,  and  the  fleshy  parts  dissolved  by  solu- 
tion of  caustic  soda.  This  aUoy  is  also  used  for 
silvering  glass  tubes,  &c. 

Bismuth  alloys  with  the  alkali  meUds; 
Johannis  (Compt.  rend.  114,  585)  has  obtained 
an  alloy  of  bismuth  and  sodium,  of  the  formula 
BiKa„  by  the  action  of  a  solution  of  sodium  in 
liquid  ammonia  on  bismuth.  The  compound 
forms  small,  dark-grey  crystalline  laminae, 
m.p.  776°,  and  takes  fire  in.  the  air.  It  mav 
easily  be  prepared  by  slowly  adding  bismuth 
to  sodium  melted  boieath  paraffin  heated  to 
300°-310°  when  the  crystals  separate  out.  An 
aUo^  with  potassium,  K,Bi,  may  be  prepared  in 
a  similar  manner  (Voumasos,  Ber.  1911,  44, 
3266).  The  alkali  bismuthides  are  readily 
oxidised  in  the  air,  turning  black,  and  bum 
eaaHj,  eiving  a  red  residue  of  alkali  bismuthate. 
They  absorb  hydrogen  at  350°,  forming  a  pro- 
duct which  is  decomposed  by  water,  evolving 
hydrogen.  They  decompose  water  slowly  at 
the  ordinary  temperature,  and  more  rapidly 
on  boiling,  and  reduce  copper  salts  in  solution  to 
metallio  copper. 

A.  H.  Gallatin  (Phil  Mag.  [4]  38, 57)  has  pre- 
pared  an  alloy  of  bismuth  with  ammonium  (7). 


He  scattered  ammonium  chloride  over  biamaui 
sodium  alloy,  and  added  water.  The  alloy 
swelled  and  then  contracted.  On  plunging 
in  water  or  heating,  a  mixture  of  h^dn^en  and 
ammonia  was  evdved.  After  drying  in  vacud 
over  sulphuric  acid,  it  evolved  27  volumes  ol 
gas  on  heating. 

CoMPou»DS  OF  Bismuth. 

Bismuth  forms  two  well-defined  dasaes  of 
compounds,  in  which  it  is  a  diad  and  a  triad 
respectively.  There  are  indications  of  the 
existence  of  some  more  highly  oxidised  com- 
pounds, but,  assuming  their  existence  to  be 
proved,  their  constitution  can  be  more  easily 
explained  by  the  assumption  of  a  higher  valency 
for  oxvgen  than  by  assuming  bismuth  to  be  a 
pentad. 

Hydride.  A  gaseous  hydride  of  bismnih 
appears  to  be  formed  by  the  solution  of  an  allov 
of  bismuth  and  magnesium  with  thorium-U 
or  radium-C  in  0*2  N  hydrochloric  acid.  It  is 
fairly  stable  at  ordinary  temperatures,  but  is 
decomposed  at  a  red  heat  and  forms  a  mirror 
in  the  Marsh  apparatus  similar  to  antimony 
(Paneth,  Ber.  1918,  51,  1704;  Paneth  and 
Wintemitz,  idem.  51,  1728). 

Oxides.  Only  two  oxides  of  bismuth*  the 
dioxide  and  the  trioxide,  are  definitely  known. 
The  statements  of  Deichler,  Hauser,  and  Vanino 
and  Treubert,  that  bismuthic  acid  and  tetroxide 
exist,  have  been  controverted  by  Gntbier  and 
Bunz  (Zeitsch.  anorg.  Chem.  48,  162 ;  49,  432 ; 
50,  210;  52,  124);  Moser  (Zeitsch.  anoig. 
Chem.  50,  33)  states  that  the  addition  of  hydro- 

ten  peroxide  to  a  bismuth  salt  precipitates  only 
ismuth  trioxide.  According  to  HoUard  (Compt. 
rend.  136,  229)  a  peroxide  of  the  formula  BiaO* 
is  formed  during  tne  electrolysis  of  a  solution  of 
bismuth  sulphate,  but  this  observation  has  not 
been  confirmed.  It  is  doubtful  whether  a  sab- 
oxide  exists. 

The  trioxide  and  the  compounds  derived  from 
it  are  the  only  ones  of  commercial  importance. 
Bifmuth  trioxide  Bi,Ot  occurs  in  naUm 
as  hiemuih  ochre.  It  is  best  prepared  by 
heating  the  subnitrate  of  bismuth  until  red 
fumes  cease  to  be  evolved.  It  may  also  bo 
prepared  by  exposing  the  metal  to  a  red-wfaite 
heat  in  a  mufite.  The  metal  then  bonis  maoA 
forms  the  oxide^  which  oondenees  as  a  yellow 


BISMUTH. 


699 


powder.  Bismuth  oxide  thus  obtained  is  a 
pale-yellow  amorphous  substance,  which  melts 
at  a  red  heat  to  a  glass  without  change  of  weight. 
Its  sp.gT.  is  8*21.  Heated  in  sulphur  dioxide  it  is 
ultimately  converted  into  a  basic  sulphate 
4Bi,0„380,. 

The  oxide  can  be  obtained  crystalline,  and 
has  been  shown  to  be  isodimorphous  with 
antimony  trioxide  (Muir  and  Hutchiason,  Chem. 
Soc.  Trans.  1889,  143). 

It  is  used  for  glass  and  porcelain  stainine ; 
as  an  addition  to  certain  fluxes  to  prevent  the 
production  of  colour ;  and  in  gilding  porcelain, 
being  mixed  in  the  proportion  of  1  part  oxide  to 
15  ^rts  of  the  ^old. 

The  darkenmg  of  the  commercial  substance 
on  exposure  to  light  is  due  to  the  presence  of  a 
trace  of  silver. 

A  bydrated  bismuth  oxide  Bi,0„H,0  is  pre- 
cipitated as  a  white  powder  on  addition  of 
caustic  alkali  to  a  bismuthous  salt,  such  as  the 
nitrate ;  but  Thibault  (J.  Pharm.  Chim.  12,  569) 
has  shown  that  under  these  conditions  the 
product  contains  appreciable  quantities  of 
oxy-  acid  salts.  By  precipitating  the  hydroxide 
from  an  alkaline  solution  by  the  edition  of  acid, 
a  pure  product  is  obtained  which  on  drying 
yields  the  pure  oxide.  It  dissolves  in  alkali  in 
presence  of  glycerol.  On  addition  of  sugar  to 
the  solution,  metallic  bismuth  is  precipitated, 
whilst  arsenic,  if  present,  remains  in  solution. 
Lowe  (Zeitsch.  anal.  Chem.  22,  498-505)  recom- 
mends this  method  for  the  preparation  of  pure 
bismuth  for  pharmaceutical  purposes. 

Blsmnth  earbonate  CO(0*BiO),  is  best  pre- 
pared by  trituratinff  powdered  bismuth  nitrate 
with  mannitol  unaer  water  until  solution  is 
obtained,  when  a  strong  solution  of  potassium 
carbonate  is  added.  Bismuth  carbonate 
separates  as  a  fine  heavy  powder  which  is 
washed  with  water,  alcohol  and  ether,  and  dried 
in  the  air  (Vaning,  Pharm.  Zentr-h.  1911,  52, 
761). 

Blsmttth  nitrate Bi(N0,)„5H,0  is  prepared  by 
•dissolvinff  bismuth  or  its  oxide  or  carbonate  in 
moderately  strong  nitric  acid.  The  concen- 
trated solution  ia  filtered,  if  neoessary,  through 
asbestos,  and  deposits  on  ooolinfr  large  deliques- 
cent cr3rstals,  mich  are  caustic  and  melt  in 
thobr  water  of  crystallisation  when  gently  heated. 
When  the  bismuth  used  for  the  preparation 
contains  arsenic,  excess  of  nitric  acid  should  be 
used  for  the  solution ;  the  arsenic  is  then  oxidised 
to  arsenic  acid,  and  combines  with  its  equivalent 
of  bismuth,  being  precipitated  as  arsenate  of  bis- 
muth. R.  Schneider  (J.  pr.  Chem.  20,  418-434) 
recommends  the  following  proportions :  2  kilos, 
bismuth,  10  kilos,  hot  nitric  acid  (75''  to  90"*) ; 
when  the  action  is  finished  the  liquid  is  de- 
canted from  the  sediment,  which  contains  all 
the  acsenic.  On  addition  of  water  to  the  solu- 
tion a  white  precipitate  of  basic  nitrate  falls,  the 
constitution  of  which  varies  with  the  amount 
of  water  used.  This  was  formerly  known  as 
magisUry  of  bismuth,  and  is  now  called  flake  or 
pemrl  white,  the  latter  name  being  also  applied 
to  the  oxychloride  of  bismuth. 

For  pharmaceutical  purposes  the  subnitrate 
is  prepared  as  follows  :  Dissolve  2  parts  of  bis- 
muth in  4  parte  nitrio  acid  of  sp.£f.  1*42,  diluted 
with  3  parts  water,  pour  from  deposit,  if  any, 
evaporate  to  one-thuxl  the  bulk,  and  pour  into 


80  parts  of  water,  filter,  wash  and  drv  the  pre* 
oipitato  at  a  temperature  not  above  55*. 

It  is  a  pearly-white  powder  consisting  of 
minute  crystiftlline  scales.  It  is  employed  as  a 
fiux  for  certain  enamels,  augmenting  their 
fusibility  without  imparting  any  colour,  and  on 
this  account  is  used  as  a  vehicle  for  metallic 
oxides.  For  the  colourless  iridescent  ^laze  on 
porcelain  the  basic  nitrate  is  rubbed  with  resin 
and  sently  heated  with  lavender  oil;  by  the 
addition  of  coloured  oxides,  yellow  and  other 
colours  are  produced.  It  is  also  used  like  the 
oxide  and  in  the  same  proportions  for  gilding 
porcelain,  and  to  some  extent  as  a  cosmetic 
under  the  names  blanc  de  fard  and  blanc 
d'E&pagne,    It  is  largely  used  in  medicine. 

When  prepared  from  impure  metal  it  is  liable 
to  contain  arsenic,  lead,  and  silver;  tellurium 
has  also  been  suspected  (Pharm.  J.  3,  No«287).  To 
test  for  arsenic,  heat  a  little  of  the  nitrate  in  a 
tube  until  brown  fumes  cease  to  be  evolved*. 
Add  a  small  crystal  of  potassium  acetate,  and 
again  heat ;  in  presence  of  a  trace  of  arsenic  the 
odour  of  kakodyl  is  observed  (A.  Glenard,  J.  de 
Pharm.  [41  1,  217). 

Bismuth  ehlorlde  BiOl,.  This  compound 
is  produced  when  finely  powdered  bismuth  is 
thrown  into  chlorine  gas  or  when  chlorine  is 
nassed  over  the  heated  metAl.  It  is  also  formed 
by  the  solution  of  bismuth  in  aqua  regia  and 
evaporation  of  the  liquid ;  or  by  distilling  a 
solution  of  the  oxide  in  hydrochloric  acid, 
changing  the  receiver  when  all  the  water  has 
distiUed  over. 

It  is  a  white,  easily  fusible  solid,  which 
absorbs  moisture  from  the  air,  forming  a  crystal- 
line hydrate.  By  the  addition  of  water  a  white 
precipitate  of  basic  chloride  or  oxychloride  is 
produced  corresponding  to  BiOCSt  though  its 
composition  vanes  considerably. 

The  oxychloride  of  bismuth  is,  however, 
usually  prepared  by  pouring  a  solution  of  the 
normal  nitrate  into  a  dilute  solution  of  common 
salt,  forming  oxychloride  of  bismuth  and  sodium 
nitrate. 

It  is  a  white  pearly  powder  known  as  pearl 
white,  and  is  used  as  a  pigment,  and  in  the  pre- 
paration of  a  very  fine  yeUow  pigment  known  as 
Merimde's  antimony  yellow  (v,  Aniimony). 
For  double  salts  of  bismuth  chloride  and  chlorides 
of  bivalent  metals,  see  Weinland,  Alber  and 
Schweiger,  Arch.  Pharm.  1916,  254,  521. 
Bismuth  chromate  v.  under  Chromium. 
Bismuth  sulphite,  produced  by  the  action  of 
sulphurous  acid  on  bismuth  carbonate,  or  by 
double  deoomposition  between  a  bismuth  salt 
and  an  alkali  sulphite,  is  a  white  crystalline 
powder,  and  is  used  in  medical  practice  to  check 
mtostinal  fermentation,  and  in  cases  of  worms. 
The  organic  compounds  of  bismuth  have  found 
many  applications  in  medicine  and  surgery. 

Bismuth  salicylate  is  prepared,  according  to 
Causse  (Compt.  rend.  112,  1220),  by  adding  a 
solution  of  a  neutral  salicylate  to  a  solution  of 
bismuth  nitrate  in  a  minimum  amount  of 
h^-drochlorio  acid.  Considerable  quantities  of 
ammonium  chloride  are  added  to  the  solutions 
before  they  are  mixed.  Hydrated  bismuth 
saUcylate  Bi(CTH,0,)„4H,0  is  thus  obtained 
as  a  white  crystalline  powder,  insoluble  in  oold 
water 

A  better  m^^Jiod  oi  preparation,  due  to 


600 


BISMUTH. 


Thibault  (Bull  800.  ohim.  25,  704).  coneiBts 
in  treating  the  bismuth  oxide  obtaiixed  by 
precipitation  from  16  parts  of  bismuth  nitrate 
with  a  solution  of  10  parts  of  salioylio  acid  in 
200  parts  of  water  ana  heating  on  the  water- 
bath  till  the  action  is  complete.  The  product 
is  decanted,  washed  with  cold  alcohol,  and  dried 
at  100*.  It  is  thus  obtained  in  rose-grey 
crystals,  which  are  soluble  without  decomposition 
in  cold  alcohol,  ether,  or  in  a  saturated  aqueous 
solution  of  salicylic  acid. 

Martinotti  and  Comelio  (BulL  Ghim.  Pharm. 
40,  141)  noint  out  that  commercial  preparations 
of  the  salt  yary  very  much  in  composition,  the 
amount  of  acid  ranging  from  6  to  67  p.a,  and 
that  of  bismuth  oxioe  from  37  to  79  p.c. 

Kebler,  however,  has  shown  (Phann.  J.  64, 
691)  that  the  alcoholic  test  of  the  British 
Pharmacgpcdia  is  too  stringent,  as  hot  alcohol 
decomposes  the  salt.  A  more  trustworthy 
method  of  testing  of  bismuth  salicylate  for  tree 
acid  consists  in  extracting  it  with  90  p.c.  benzene 
and  filtering  the  extract  into  dilute  ferric 
chloride  solution  (1  in  3000),  when  a  violet  ring 
is  produced  at  the  junction  of  the  two  liquids 
if  nee  acid  is  present. 

Basle  bismuth  gaUate,  known  commercially 
as  *  dermatol,*  is  prepared  as  follows  :  306  grams 
of  basic  bismuth  nitrate  is  dissolved  in  328  grams 
nitric  acid  of  strength  38*B.,  diluted  with  200 
grams  water.  The  solution  is  filtered  through 
glass-wool,  evaporated  down  to  600  grams,  and 
allowed  to  crystallise.  The  product  is  dissolved 
in  980  grams  glacial  acetic  acid,  diluted  with 
8  litres  of  water,  and  then  mixed  with  a  solution 
of  188  grams  crystallised  saUic  acid  in  8  litres  of 
water.  The  precipitate  m  bismuth  gaUate  t^us 
produced  is  washed  five  or  six  times  with  water, 
pressed,  and  dried  (Hartz,  Pharm.  Bundach. 
12, 182). 

Another  method  consists  in  treatins  a  solu- 
tion of  bismuth  nitrate  in  nitric  acia  with  a 
solution  of  gallic  acid  in  70  p.c.  alcohol,  nearly 
neutralising  with  sodium  hydroxide  or  sodium 
carbonate,  and  finally  adding  considerable 
quantities  of  sodium  acetate  or  diluting  largely 
with  water.  The  compound  is  thus  obtainea  as 
a  yellow  precipitate,  wruch  is  collected  and  dried 
{EDg.  Pat.  6234,  1891). 

The  empirical  formula  of  the  substance  is 
BiCfH^Of,  and  Thibault  (J.  Pharm.  Ghim.  14, 
487)  considers  that  it  is  really  bismuthogallic 
acid,  adducing  in  favour  of  this  view  the  fact 
that  with  alka£s  it  forms  salts  of  which  potassium 
bismuthogallate  K.BiC^HfOf  is  a  type. 

A  general  method  for  the  preparation  of 
bismuth  salts  of  organic  acids  is  the  solution 
of  freshly  precipitated  bismuth  hydroxide  in 
a  solution  of  the  acid  (Fischer  and  Grfitzner, 
Arch.  Pharm.  1894,  232,  460;  v.  also  Telle, 
ibid,  1908, 246, 484,  for  the  preparation  of  bUmtUh 
laciaie  by  this  method). 

Basle  bbmuth  dibromohydrozyiiaphthoate, 
which  has  been  suggested  as  a  substitute  for 
iodoform  in  surgi^  dressings  (G.  Richter, 
Apoth.  Zeit.  1908,  23,  600),  is  obtained  by  a 
similar  method.  /3-hydroxynaphthoic  acid  is 
brominated  in  acetic  add  solution,  and  the 
recrystaUised  product  heated  with  bismuth 
hydroxide.  The  salt  is  a  finely  crystalline^ 
yellow,  odourless,  insoluble  powder,  which  is 
una£fected  by  heating  to  110  . 


Bismuth  chrysophanate  ('  Dermot*) 
Bi(C„H,OJ,Bi.O,(t) 
a    yellowish-brown    powder,   is,   according    to 
Merck,  a  mixture  of  impure  chrysarobin  and 
bismuth  hydrate. 

Compounds  of  bbmuth  with  phenob  are 
obtained  by  double  decomposition  between  an 
alkaline  salt  of  the  phenol  and  a  salt  of  bismuth, 
such  as  the  nilrate.  Among  those  that  have 
been  made  commercially  may  be  mentioned : 

orphol  (the  jS-naphthol  compound) 
CioH,OBi(OH),+Bi,0,+H,0  ; 

xeroform  (the  tribromophenol  compound) 
(C,H,Br,0)aBiOH+Bi,0, ; 

hdcosol  (the  pyrogallate) 

[C,H,(OH),0],-Bi-OH. 
An  important  pathological  application  of  bis- 
muth salts  is  their  Mlministration  internally 
in  order  to  outline  parts  of  the  body  in  Rontgen 
ray  work. 

Bbmuth  oxylodosubgallate  CcH,(OH:),<X>a- 
Bil(OH),  *  aifvl,*  is  prepared  by  heating  together 
in  60  parts  of  water  36  parts  bismuth  oxyiodide, 
and  18*8  parts  gallic  acid  until  the  product  is  a 
sreyish-green  powder.  It  is  used  as  a  substitute 
for  iodolorm. 

Other  compounds  of  bbmuth  to  whioh  trade 
names  have  been  given  are: 

Bismol,  bismuth  methylenedigallate^  ob- 
tained by  the  general  method  from  t£e  hydroxide 
and  metnylenedigallio  acid. 

Markaaol,  bismuth  borophenate. 

Thioform,  bismuth  dithioealicylate,  need  as 
a  substitute  for  iodoform  {v.  Synthbtio  Dscroa). 

Tertiary  aromatic  bbmuthines  and  their 
halogen  derivatives  have  been  prepared  by 
Challenger  (Chem.  Soc.  Trans.  1914,  106,  2210). 
Other  organo-bismuth  compounds  have  been 
described  by  Lowig,  Annalen,  1860,  76,  365; 
Breed,  ibid.  1862,  82,  106;  Dunhaupt,  ibid, 
1864,  92,  371;  MiohseUs  and  coUaboratois, 
Ber.  1887,  20,  62,  64,  1616 ;  1888,  21,  2035 ; 
GiUmeister,  Ber.  1897,  30,  2843 ;  Pfei£fer  and 
Pietsch,  ibid.  1904,  37,  4620;  HUpert  and 
Gruttner,  ibid.  1913,  46,  1686;  HUpert  and 
Ditmar,  ibid.  3741 ;  Ehrlich  and  Kanet,  ibid. 
3664  ;  Vanino  and  Mus^nug,  Ber.  1917,  50,  21. 

BISMUTHINITE  or  BISMUTH-GLANCE. 
Native  bismuth  sulphide,  Bi^S,,  occurring  as 
acicular  or  bladed  orthorhombic  crratals  or 
lamellar  masses,  very  like  stibnite  (Sb^^  in 
appearance.  In  Queensland  and  Bolivia  it  is 
found  in  sufficient  abundance  to  be  mined  as  an 
ore  of  bismuth.  L.  J.  8. 

BISHUHTE.  Basic  bismuth  carbonate,  con 
taining  about  90  p.c.  Bi^O^;  formula  perhaps 
Bi|0,CX),HtO.  It  is  a  yellowish  earthy 
material,  and  presenting  such  an  appearance  is 
surprisingly  heavy  (sp.gr.  variously  given  as 
6*9  and  7*6).  It  occurs  as  an  alteration  product 
of  native  bismuth,  and  in  Bolivia  is  an  important 
ore  of  this  metal.  L.  J.  8. 

BISMUTOSE  V.  Symthbtic  Drugs. 

BISTRE  V.  Pigments. 

BISULPHIDE  OF  CABBOH  v.  Cadxm 
diaulphide,  art.  Casbok. 

BITTER  ALMOND  OIL  v.  Benzaldbhyds, 
and  Oils,  Essehtial. 

BITTER  APPLE  v.  Colocvnth. 

BTTTER  SWEET  v.  Dxjlcamaba. 

BITTER  WOOD  v.  Quassia. 


BLACKING. 


601 


BITTERN.  The  mother  liquor  which  re- 
mains after  the  oiystalliBation  of  common  salt 
from  Bea-water,  or  Hie  water  from  salt  Bprings. 
It  oontainB  soluble  magnesium  salts,  bromides, 
and  iodides. 

The  same  term  is  also  applied  to  a  mixture 
of  equal  parts  of  quassia  extract  and  sulphate  of 
iron,  2  parts  extract  of  Coceulus  indicus,  4  parts 
Spanish  liquorice,  and  8  parts  treacle,  used  to 
Bophistioate  beers. 

JUTUMEN.  This  term  includes  a  consider- 
able number  of  inflammable  mineral  substances 
oonaisting  mainly  of  hydrocarbons.  Thev  are  of 
yariouB  consistence,  from  thin  fluid  to  solid,  but 
the  solid  bitumens  are  for  the  most  part  lique- 
fiable  at  a  moderate  heat.  The  purest  kind  of 
fluid  bitumen,  called  naphtha  or  rock  oil,  is  a 
colourless  liquid  of  sp.gr.  0'7-0'84,  and  with  a 
bituminous  odour,  it  often  occurs  in  nature 
with  asphalt  and  other  solid  bitumens.  Petro- 
leum is  a  dark-coloured  fluid  variety  containing 
much  naphtha.  Mfldtha  or  mineral  tar  is  a  more 
viscid  variety.  The  solid  bitumens  are  asvhaU 
{q*v.);  mineral  iattow  or  hatchelin;  tUulic 
hUumen^  mineral  caoutchouc  or  daieriU;  ozo- 
keriU,  &c. 

An  abundance  of  bitumen  is  found  in  the 
island  of  Trinidad  at  the  Pitch  Lakes,  and  in 
Mexico.  It  is  supposed  to  be  a  product  of  the 
decomposition  of  vegetable  matter,  and  consists 
chiefly  of  hydrocarbons  with  variable  quantities 
of  oxygen  and  nitrogen  {v.  Pitch). 

BITUMINOUS  COAL  v.  Fdkl. 

BDCEIN,  BDON.  Colouring  matters  of 
annatto  (v,  Annatto). 

BLACK  BAND  IRONSTONE  v.  Ibon,  Ores  of. 

BLACKBERRIES.    The  fruit  of  the  bramble, 

Bubus  fnUicostis.    Konig  gives,  as  the  average 

composition : 

Free  Other  carbo- 

¥rater    Protein    acid      Sugar  hydrates  Fibre      Ash 

86*4        0-5        1-2        4-4        1*8        5*2        0*5 

The  seeds  contain  about  12-6  p.c.  of  a  drying 
oil,  8p.gr.  at  !&"  0*9256,  iodine  number  147*8, 
the  liquid  fatty  acids — ^about  91  p.c.  of  the  oil, 
contain  about  80  p.o.  of  linolio  acid,  17  p.c.  of 
oleic  acid,  and  3  p.c.  of  linolenic  acid,  whilst  the 
Bolid  acids,  chiefly  palmitic  acid,  amount  to 
about  4*7  p.c. ;  volatile  acids  are  not  present  in 
the  oil.  A  small  quantity  of  phytosterol  is 
present  (Kiziian,  Chem.  Rev.  Fett  u.  Harz,  Ind. 
1908,  16,  7).  For  a  study  of  the  colouring 
matter  of  the  fruit,  tee  Veoohi  (Chem.  Zeit.  1914, 
L  1209).  H.  L 

BLACK  BOY  GUM  v.  Balsams. 

BLACK  CHALK.  A  kind  of  clay  containing 
carbon,  found  in  Carnarvonshire  and  in  the  Isle 
of  Islay. 

BLACK  COPPER  v.  Copper. 

BLACK  EARTHY  COBALT  v.  Cobalt. 

BLACK  FLUX  v.  Assaying. 

BLACK  HAW.  The  dried  bark  of  Viburnum 
prunijclium  (Linn.). 

BLACK  HELLEBORE  ROOT.  Radix  Utile- 
hori  nigri.  {Racine  d*ElUbore  noir,  Fr. ;  Schwarze 
Nieatpurzel,  Ger.). 

The  root  of  the  Heliebarue  niger  (linn.)  or 
Christmas  Rose  (WoodviUe,   Med.   Bot.    169  ; 


Bentl.  a.  Trim.  2).  Black  hellebore  and 
the  nearly  related  sreen  hellebore,  HeUeborua 
viridis  (Linn.),  are  seldom  employed  in  England 
except  in  veterinary  medicine.  They  are  both 
powerful  intestinal  irritants.  {Veratrum  viride 
and  F.  album,  also  known  as  green  and  white 
hellebore  respectively,  are  very  different  plants, 
and  contain  alkaloids.) 

According  to  Husemann  and  Marm6  ( Annalen, 
133,  65),  both  species  of  Helleborua  contain  a 
glucoside  heUebor^n,  and  a  smaller  quantity  of 
a  second  glucoside  hdUborin,  The  former  is, 
according  to  Siebuig  (Arch.  Pharm.  1913,  251, 
154),  an  amorphous  saponin  (CiiHs^Oiq)^,  and 
is  hydrolysed  bv  boiling  dilute  si:dphuric  acid  to 
2  mols.  each  of  dextrose  and  araoinoee,  1  mol. 
of  acetic  acid,  <icid  heUeboretin  CfiB.^fiy  (a 
lactone  7),  and  7ieutral  HeUeboretin  CuK^fi^,  a 
greenish-black  mass.  Helleborein  is  not  a 
suitable  substitute  for  digitcdis  (r/.  also  Thaeter, 
Arch.  Pharm.  1897,  235, 414).  Helleborin  melU 
with  decomposition  at  150^,  dissolves  eaailv  in 
boilins  alcouol  or  chloroform  and  gives  a  aeep 
red  solution  with  sulphuric  acid. 

BLACKING.  Blacking  for  shoes  is  mentioned 
aa  early  as  1598,  but  it  was  not  introduced  into 
England  until  the  reign  of  Chailes  U.  It  con- 
sists  of  (1)  black  TOne  charcoal  (free  from 
calcium  phosphate,  otherwise  it  is  subeequentlv 
treated  with  dilute  sulphuric  acid)  ana  black 
colourinff  matter ;  (2)  a  mixture  of  sugar  and 
oil,  whidi,  on  rubbing,  imparts  the  gloss ;  and 
(3)  fatty  matter  for  preservation  purposes. 

Camauba  wax  with  its  hardness  and  high 
melting-point  is  the  basis  of  modem  friction 
polishes.  The  cheaper  candelilla  wax  may,  to  a* 
certain  extent,  replace  the  camauba  with  but 
little  difference  in  the  quality  of  the  polish. 

There  are  two  chief  methods  for  working 
these  waxes  into  polish  :  The  wax  is  emulsiOea 
by  boiling  in  a  solution  of  borax.  The  product 
is  known  as  white  stock.  If  polish  is  to  be  in  the 
form  of  paste,  the  white  stocK  while  hot  is  mixed 
with  a  not  solution  of  ordinary  laundrv  soap 
and  sufficient  nigrosin  to  give  the  desired  depth 
of  colour.  The  mixture  cools  as  a  soft  paste 
that  may  readily  be  applied  by  means  of  a  brush 
or  sponge.  If  the  polish  is  desired  in  the  liquid 
form,  the  best  grade  of  Castille  soap  is  used ; 
a  solution  of  this  variety  of  soap  does  not 
gelatinise.  Numerous  trials  have  shown  that 
no  matter  how  dilute  the  soap  solution,  a  satis- 
factory liquid  cannot  be  obtained  unless  Castille 
soap  is  usisd.  Both  the  paste  and  liquid  forms 
are  widely  used.  With  a  moderate  friction, 
the  hard  waxes  held  upon  the  leathar  by  the 
soap,  give  a  beautiful  and  very  desirable  polish. 

The  second  method  of  dealing  with  the  hard 
waxes  is  as  follows :  Camauba  or  candelilla  or 
a  mixture  of  the  two  with  beeswax  and  ceresin 
or  paraffin  is  dissolved  in  hot  turpentine  and 
mixed  with  very  finely  pulverised  bone  charcoal. 
When  properly  coolea  Uiere  results  a  firm  paste 
that  spreads  rapidly  under  a  brush  or  sponge. 
When  this  mixture  is  poured  into  boxes  it  must 
be  properly  cooled,  otnerwise  there  is  a  separa- 
tion of  the  harder  waxes  from  the  solvent,  the 
result  being  a  granular  sloppy  mass  instead  of  the 
firm  paste  desired.  If  the  harder  waxes  alone 
were  used  it  would  be  difficult  to  prevent 
septuration  from  the  turpentine  on  cooling,  hence 


602 


BLACKING. 


the  admixture  of  softer  waxes.  Beeswax  gives 
also  a  toughness  or  lack  of  shortness  to  the 
paste,  and  a  smooth  finish  that  cannot  be 
obtained  without  it.  These  softer  waxes  reduce 
the  gloss  available  from  the  camauba  or 
cand^illa.  The  use  of  bone  black  as  a  colouring 
agent  is  an  attempt  to  overcome  the  weakness 
inherent  in  the  use  of  the  softer  waxes,  and  to 
add  to  the  gloss  obtainable  from  the  waxes 
that  obtained  by  friction  of  the  bone  carbon. 

For  tan  leathers  the  same  goods  are  used, 
except  that  a  brown  or  yellow  <fye  and  pigment 
replace  the  nierosin  and  bone  char.  The  appli- 
cation of  the  ian  polish  is  frequently  preceded 
by  the  use  of  a  cleaning  solution  to  remove 
stains  and  discolouration  (J.  T.  Donald,  J.  8oc. 
Chem.  Ind.  1913.  32,  459). 

A  liquid  hlackina  can  be  prepared  from  120 
parts  of  ivory  blaok,  90  parts  brown  sugar,  16 
parts  olive  oil,  and  BOO  Pftrts  stab  beer.  The 
ivory  black,  sugar,  and  olive  oil  are  mixed  into 
a  smooth  paste,  and  the  beer  added  under 
constant  stirring  (Hiscox,  1907). 

A  German  recipe  is  as  follows:  20  parts 
Marseilles  soap  are  dissolved  in  375  parts  of 
warm  spirit  (25  p.o.)  and  40  parts  of  glyoerol 
added ;  this  is  shaken  and  added  to  a  solution 
of  200  parts  of  shellac  dissolved  in  1000  parts 
of  spirit  (95  p.o.)  and  5  pBtrts  nigrosine  in  125 
parts  of  spirit  added.  The  mixture  is  well 
shaken  in  a  closed  vessel  and  left  for  a  fort« 
night. 

Liquid  polish,  4  os.  asphaltum,  8  fl.  oz. 
turpentine,  3  fl.  ok.  of  gold  size,  ^  oz.  nigrosine, 
and  3  fl.  OS.  linseed  oil.  The  mixture  is  heated 
until  uniform  and  thinned  down  to  desired  oon- 
sistence  with  oil  of  turpentine  (Phot.  J.  Deo. 
1908,  738). 

Day  and  Martin's  chief  blaokins  is  obtained 
by  mixing  ground  animal  charcoal,  sperm  oil, 
raw  sugar  or  treacle,  and  a  small  portion  of 
vinesar.  Dilute  sulphurio  acid  is  then  added 
to  tne  mass  until  intumescence  ceases,  and 
the  product  is  thinned  by  the  addition  of 
vinegar. 

Bryant  and  James's  indiarubber  blacking  is 
prepared  by  trituratinff  thoroughly  18  oz.  very 
nne  shreds  of  indiarubber,  9  lbs.  hot  rapeseed 
oil,  60  lbs.  finely  powdered  animal  charcoal, 
45  lbs.  treacle,  1  lb.  gum  arable  previously 
dissolved  in  20  galL  vinegar.  The  whole  is 
placed  in  a  wooden  vessel,  and  12  lbs. 
sulphuric  acid  added  in  small  quantities  at 
a  time,  and  stirred  for  i  hour  daily  for  14 
days,  3  lbs.  of  finely  sround  gum  arable  added, 
and  stirrilig  continueoL  for  14  da3r8.  If  required 
in  the  paste  form,  only  12  gall,  vinegar  added  and 
6  or  7  oays*  stirring  is  suflSoient. 

Brunner  makes  a  blacking  by  stirring  10 
parts  of  bone  black  with  100  parts  of  glucose 
syrup,  and  5  parts  sulphuric  acid  added  with 
rapid  stirring  until  the  mass  is  homogeneous. 
2  parte  of  bckUi  are  dissolved  in  4  parts  water, 
and  20  parts  train  oil  added  and  ooiled  with 
constant  stirring  until  a  thick  liquid  is  formed : 
the  other  mixture  is  then  added  with  repeated 
stilling. 

A  cheap  and  good  shot  blacking  may  be  pre- 
pared by  mixing  1  lb.  of  ivozy  black,  1  lb. 
molasses,  8  tablespoonfuls  sweet  oil,  and  1  oz. 
of  gum  arable,  diraolved  in  2  quarts  of  vinegar 
and  i  lb.  of  oU  of  vitrioL 


Paste  blacking.  Mix  16  oz.  ivory  black, 
16  oz.  lampblack,  6  oz.  treacle,  5  oz.  vinegar, 
and  4  oz.  snerm  oiL  Mix  and  add  gndnally 
4  oz.  sulphurio  acid.  When  intumeeoenoe 
ceases,  add  ^  oz.  of  iron  sulphate,  6  oz.  gam 
arable,  and  5  oz.  water  (Phann.  Formula. 
1908, 378).  ^ 

Sticks  of  blacking  of  plastic  consistence  are 
made  from  the  following :  5  oz.  stearin,  5  oz. 
paraffin  wax,  2^  oz.  camauba  wax,  2)  oz. 
lustrous  pitch,  and  7  oz.  turpentine  (Phann.  J. 
Pat.  2564,  1908). 

Hiscox  describes  the  following  paste:  122 
parte  BCarseilles  soap,  61  parts  potassium  car- 
bonate, 500  parts  beeswax,  and  2000  parts 
water  are  mixed  with  constant  stirring  and 
153  parts  rock  candy  (powdered),  61  parts  ffom 
aiabio,  and  1000  parts  ivory  blaok  are  added 
with  constant  stirring. 

Boot  polish.  6i  oz.  ozokerite,  2  lbs.  oerasin, 
5^  oz.  camauba  wax,  1}  oz.  beeswax,  4  pints 
turpentine,  2  lb&  lampblack,  20  srams  uack 
aniline  dye,  and  perfume  added  if  desired  (Pharm. 
J.  1908,  506). 


8d/-shining  blacking.  Dissolve  4  oz.  sum 
arable,  1^  oz.  coarse  sugar,  i  pint  good  bUok 
ink,  and  1  oz.  sweet  oil,  rob  m  a  mortar,  add 


2  oz.  strong  vinegar,  and  add  lastly  1  oz.  rectified 
spirits  (Scientific  Amer.  1903, 39). 

French  shoe  dressing.  32  oz.  vinegar,  8  oz. 
logwood,  and  ^  oz.  potassium  dichromate  are 
boiled  and  stramed  whilst  hot  into  a  mixture  of 
4  oz.  gelatine,  4  oz.  tragaoanth,  4  oz.  glyoerol 
and  15  oz.  water.  The  mixture  is  allowed  to 
stand  for  some  hours:  2  oz.  indigo  are  then 
added,  and  the  whole  triturated  m  a  mortar 
(Pharm.  Form.  1908) 

Boot-top  liquid.  I  oz.  oxalic  acid,  1  oz.  zino 
sulphate,  dissolved  in  30  oz.  water.  Apply 
witn  a  sponge  to  the  leather,  which  has  oeea 
previously  washed  with  water,  then  wash  off 
with  water,  and  dry  (Workshop  Receipts,  1909^ 
123). 

For  kid  shoes,  2  oz.  gum  shellac,  1  oz. 
aqueous  ammonis,  8  oz.  water,  and  aniline  blaek 
enouffh  to  colour.  The  first  two  ingredients 
are  neated  almost  to  boiling,  and  water  is 
added  to  make  the  whole  measure  16  os. 
(Scien.  Amer.  1903,  39). 

Waterproof  blacking.    6  oz.  caoutchouo  and 

3  lbs.  hot  rape  oil  are  added  to  20  lbs.  ivory  Uaok, 
15  lbs.  molasses,  and  6  or  7  galL  vinegar  in  which 
6  oz.  ground  gum  arable  baa  been  dissolved; 
then  add  4  l^  sulphuric  acid  and  stir  con- 
stantly. Allow  to  stand  for  2  weeki,  then  add 
1  lb.  fine  gum  arable  Stir  daily  daring  2 
weeks,  and  bottle  (Workshop  Receipts,  1909, 
124). 

For  dress  boots.  8  oz.  gum  arable  and  2  oz. 
molasses  dissolved  in  2  oz.  ink  and  I  pt. 
vinegar.  This  is  strained,  and  2  oz.  spirits  of 
wine  added. 

BLACK"JACK.  A  miner's  term  for  blende, 
or  zinc  sulphide  (v  Zinc).     V.  Zutoblendx. 

BLACK  LEAD.  The  common  name  ol 
plumbago  or  graphite  {v.  Gabbon). 

BLACKLEV  0LUE  V.  iNDULorxs. 

BLACK  LIQUOB.  Ferrous  aoetate  («.  Aoqrio 
▲oid).  

BLACK  MUSTARD  SEED  OIL «.  Rapi  on.: 
Oils  and  Fats. 

BLACK  TBLLURIUM  «.  TiLLUBnni. 


BLACK  TIN  r  Tin. 
BLACK    VABNISB  ( 


BLACK  JAPAN 


BLACK  WAD  v.  MAKOAtnm. 
BLACK,     WOOL. 


Aw>- 


BLAHK  riX£.  Trade  name  for  ground 
buinm     nilpluta      lued     u    a     pigment     (i'. 

BLANKIT.  A  tnda  or  iMtor;  E«rm  lor 
•odinin  hjdioaiilphite. 

BLAKQCETTE.  A  kind  of  crude  Boda,  Uaa 
OMUtio  than  bwilla,  obtained  at  Aiguee-Uwtes 
bj  the  inoinenttion  ol  SaUola  kali. 

BLAST  FUBMACB  QAS  v.  Fdeu 

BLASTING  QBLATUE  AND  POWDEB  v 

BLAD  or  BLUE  OAS.   A  mliluieot  volatite 


n  solation  under  preainre. 
■olntiim  ia  filled  into  st«el  cjlinders,  and  i»  thus 
kvailable  (or  tnuupoit  Used  for  illuminating, 
hektina,  and  power  purpoaee  (Uallock,  J,  Soc. 
Chem.likd.  1906,  060J. 

BLEACfliHG.  Thia  term  aignifiea  the  art 
of  destroying  the  natural  colour  of  T^etablo 
and  aninial  products  iu  such  a  manner  as  to 
leave  them  nnimpairsd  with  as  white  an  appear- 
ance as  possible.  The  removal  of  certain  other 
natnnJ  or  artificial  impurities  usually  acoom- 
paniee  the  bleaching  proper.  The  art  acquirea 
ita  greatest  importance  in  oonnection  with  the 
textile  6 bre«,  cotton,  linen,  wool,  and  silk;  hence 
apeoial  roferenoe  will  be  made  to  the  modem 
methods  of  bleaching  theae  materials. 

Cotton  HMCblnc.  Cotton  is  usually  bleached 
in  the  fonn  of  yarn,  thread,  and  fabric,  seldom 
M  loose  oottOD-wool.  The  natural  impurities 
oecnrring  in  taw  ootton  amount  to  about 
S  p.a.,  and  consist  chiefly  of  peotio  matbeia  ; 
oUier  substances  present  are  brown  colouring 
matter  and  very  minute  quantities  of  a  fatty 
acid,  cotton  wax,  and  albuminous  matter.  The 
•oiled  grey  appeaTuice  of  raw  ootton-wool,  yam, 
and  tfajcead  is  almost  entirely  due  to  the  preeenoe 
of  these  natural  impurities.  Cotton  cloth  or 
calico,  however,  is  still  further  contaminated 
with  flour  or  starch,  fatty  matter,  China  clay, 
and  other  mbersi  eubatAaoee,  aL  of  which,  to 
the  amount  of  30-60  p.a.,  have  been  intoodnced 


cotton  yarn  is  in  the  form  of '  warps,'  these 
loosely  plaited  by  hand  or  machine  in  order  to 
rednoe  Uieir  inoonvenient  length  ;  if  in  the  form 
of  *  hanks,'  these  are  hleai^ed  separately  or 
linked  together  in  chain  fonu  ;  weft  yam  is 
sometimes  bleached  in  the  form  of  '  oops,'  i.e. 
rewly  for  the  spool  of  the  weaver's  shuttle. 


Bleep  undei  sieve  likll  an  nuoi     *aah 
under  sieve  half  an  hour  and  afterwards 
in  waahina  machine. 
4.  jScopin;     an^     blueing.     Soap     solution 
about  e  grams  per  Utre,  with  addition 

-I 11 .:. — I  -Ti(iig(,.pm.pio  (indi- 

e  at  soda),  steep 


got 

2  hours  under  sieve. 
.   Dum^ng.     Pass   tikrough   doming   i 


containing  soap  solution  and 
indigo -purple,  as  in  operatimi  No.  4 ; 
wash,   sqneeie   or  hydro^eztract,  and 

Tie  first,  seoond,  and  third  operations  are 
repeated  in  the  ease  of  thread  because  of  its 
closer  texture.  For  the  second  ley-boil,  30  litres 
oaastic  soda  (sp.f^.  I'lB)  and  15  kilos,  soap  ue 
used  i  the  cbemioking  and  souring  are  exact 
repetitions. 

The  ley-boit  takes  plaoe  in  Isriie  iron  boilera 
of  '  kiers,    a  representation  of  which  is  shown 


The 


rerat"  operations    of    the    Ueaobing 
for  ISOO  Kilos,  yam,  employing  low 


preesote  kien,  an  as  follows  :- 

1.  Ltji-boiL    300  litres  caustic  soda  (sp.gr. 

116),  2000  Ltres  water,  boil  6  hours; 
wash  in  kier  1  hour. 

2.  Clumicting.     Bleaching-powder    solution 

(Bp.gr.  1  -006),  steep  under  sieve  2  hours ; 
wash  tmder  sieve  naif  ui  honr. 

3.  Sowitig.     Snlidinrio   acid   (ap.gr.    1-006), 


L 


0  is  a  perforated  false  bottom  ;  D  is  the  lid 
hinged  at  x  and  capable  of  being  readily  lifted 
by  means  of  a  aham  and  counterweight ;  v  is 
an  air  valve,  L  a  steam  pressure  gauge ;   h  sjid 

1  are  the  steam  and  Uquor  pipes  connected  bv 
the  two-way  valve  K  with  the  pipe  t,  whiefa 
enters  the  kier  immediately  below  the  pafler 
pipe ;  Q  is  the  let-ofi  valve. 

When  such  a  kier  has  been  oharged  with 
yarn  and  caustic  soda  solution,  the  lid  is  fastened 
down  and  steam  is  admitted.  The  liquor  below 
the  false  bottom  soon  begins  to  boil,  and  as  the 
pressure  of  steam  increases,  a  portion  of  the  boil- 
ing liquor  is  forcibly  ejected  np  the  puCFer  pipe 
and  spread  over  the  yam.  The  liquor  drMsa 
through  the  yam,  soon  to  be  ejected  as  before. 
In  this  intermittent  manner  the  circulation  of 
the  boiling  liquor  is  maintained. 

The  apparatus  for  chemioking,  sonring,  wash- 
ing under  slevei  soaping  and  blaeing,  shown  in 
Fig.  2,  consists  <A   a  stone  twik,  ■,  with  per- 


BLBACHING. 


foTkted  false  bottom  f,  uid  lommunioaliiiie  by 
the  velre  a  with  the  ttome  tank  d  below.  The 
ch&ia  of  yun  is  drewD  from  the  kier  uid  led 
into  the  tank  ■  by  means  of  the  irmoh  A. 
When  ■  is  auitably  filled  with  jun,  the  liquoi 
in  tank  D  is  laised  by  the  pnmp  o  to  the  uere 
r',  whence  it  drains  througu  the  yarn  into  the 
well  below,  sgain  to  be  pumped  Dp  u  before  ; 
B  in  the  eooentria  wheel  on  Tevolving  shaft  b; 
which  the  pump  is  worked. 

The  '  dompiDg '  machine  referred  to  ooniiata 
of  a  pair  of  hearv  wooden  rollei*  ^aoed  over  a 
luge  wooden  tank  oootaininn  the  soap  solution.  [ 


•  oTOM-wonnd  tfooTt '  {'  ehMMi '}.  The  cop* 
may  be  packed  in  wicker  baskets  or  in  linen 
bags  and  boiled  in  an  ordinary  kier,  or  they  am 
treBt«d  in  Bpecial  cop^feing  appuatus.  It  is 
preferable  to  use  a  solution  of  sodium  hypo- 
chlorite in  place  of  a  bleaobing-powder  solution. 
Cotton-eloth  or  mUn  bleubloc  Accord- 
ing to  the  pun)ose  for  iriiioh  the  bleaehed 
material  is  intenoed.  We  may  distinguish  between 
the  madder  bltach,  the  marktt  bltaeh,  and  tb> 
Tviiey-Ttd  bUach. 

Th«  madder  UeMb.  This,  the  most  thorough 
kind  of  calico  bleaching,  is  in  general  use  with 
.  oslloo-prlntert.  It  aims  at 
^  entirely  removing  eveiy  im- 
r  purity  which  will  attract 
'  Dolouiing  matter  in  the  madder 
or  other  dye- bath,  so  that  the 
finished  print  may  have  a 
pure  wliit«  groond. 

Before  proceeding  to  the 
actual  bleaching  process  the 
preiiminor;  operations  of 
Mamjiing,  ttiiclung,  and  tittgt- 
ing  have  to  be  periormed. 
To  ...        - 


Pio.  8. 

The  upper  roller  is  eorered  widi  cotton  rope 
and  rests  loosely  on  the  lower  one.  The  yoin  is 
first  passed  throngh  the  soap  solution  and  then 
between  the  Bqueesing  rollers  ;  the  irregularities 
caused  by  the  unking  or  plaiting  impart  to  the 
upper  roller  a  oonstsjit  jumping  motion,  which 


When  honk  yam  is  not  linked  to  form  a 
chaiu,  but  treated  as  separat«  honks,  '  wash 
stoeki'  in  which  the  yam  is  subjected  to  (be 
beating    aotion    of    heavy    wooden    hammers. 


ol  yarn  In  tli«  loim  ol  '  eopi '  oi 


cloth  and  to  trace  damages, 
the  end*  are  stamped  with 
numbers  and  lettms,  usually 
with  thick  gas  tar,  oocaaion- 
ally  with  amline  black.  The 
pieces  are  then  stitched  to- 
gether by  machine. 

The  aingtiitg  operation  is 
for  the  poipose  of  buming 
oR  the  looee  fibres  on  the 
surface  of  the  calico,  sinoo 
they  int«ifere  with  the  pro- 
ductioQ  of  fine  impressioDa, 
and  are  apt  to  give  rise  to 
certain    defects    during    the 

iirinting  prooess.  It  is  per- 
armed  by  rapidly  passing 
,  the  cloth  in  the  open  width 
over  red-hot  copper  platea  or 
cylinders,  or  over  a  row  of 
Bunsen  ^as  flames.  We  may 
distinguish,  therefore,  between 
jiiate  lingetng  and  ^iw  amgeina, 
the  former  being  generally 
preferred  for  thick  heavy 
doth,  the  latter  for  light  thin 
sloth,  muslins,  &c. 

In  plate  singeing  it  is  im- 
part«nt  that  th«  platee  be  kept 
at  a  uniform  strong  red  heat 
sufGoiently  high  to  overoome 
the  cooling  actionof  the  rapidly 
moving  cIotL     The  best  results  are  obtained 
by  means  of  the  '  singeing  roller,'  which  con- 
sists   ol    a   slowly    revolving    copper   cylinder 
through  which  a  furnace  flame  is  conducted. 
In  this  case  the  cloth  presses  continually  against 
a  different  portion  of  the  red-hot  surface  ol  the 
roller ;   the  cooling  action  is  thus  reduced  to  a 
minimum,  and  a  rt^ulor  even  singe  is  the  Msdt 
All   singeing   machines   are   provided   with 
lever  arrangements  for  immediately  removing 
the  cloth  from  the  hot  plate,  or  the  gss  Smm 
from  the  cloth,  in  case  of  neoessity ;    further 
danger   from   fire   is  avoided   by   causing   tbs 
singed  cloth  to  pass  at  once  between  a  pair  of 


BLBACHIKQ. 


roUen  inoiit«iied  with  mter,  or  thnnfik  »  itaall 
•t««m  ohambar,  in  order  to  eztingnuh  apulu 
adhoriiig  to  tbe  cloth. 

The  aboTfl  preliminuy  operations  bt«  nov 
succeeded  b}*  those  of  the  bluchiiig  proper. 
The  foUowii^  is  ut  outline  of  the  procen  at 

Creeeul  in  nee  for  24,000  kilos,  cloth,  employing 
■w-pmauTe  kiers : — 

1.  Wuh  after  nDKeins. 

2.  Limt-boU.     1000  kiloa.  lime,  water  about 

37,000  litres  ;   boil  12  hours  ;   wash. 

3.  lAnu   tour   or   grey-iovr.     Psm    through 


about  37,000  litree ;   boil  3  hours. 

Znd.     800   kihM.    soda     ash,    3S0 
kilos,    lesin,   190    kilos,    oaostic    soda 


(■oUd),   water  87,000   litre* ;    boU  12 

3rd.  380    kilos,    soda    ash,    water 

37,000  litres  ;    boil  3  hours ;   wash. 
6.  Chtmickitig.     Pass     through     bleaching- 

powder  eolation  (sp.gr.   l-002f>) ;    pUe 

2-12  hours ;  ffseh. 
6.  Whilt-*our.    Past   through   hydroohlorie 

or  snlphurie  acid  (sp-gr.   1-01);    pile 

1-3  hour*. 


machine  in  rope  form,  then  plaited  down  on 
the  floor  and  allowed  to  lie  '  m  pile'  for  some 
boors  to  soften.  By  this  operation  the  oloth  is 
well  soaked  with  water,  and  is  thus  better  pre- 


Fia.  3. 

pared  to  abeorb  the  liquors  nsed  in  the  sub- 
sequent operations.  Should  the  doth  be  heavily 
siied,  much  of  the  adventitious  matter  Is  also 
removed  at  this  stage. 

The  form  of  washing  machine  generally 
employed  is  shown  in  Figs.  3  and  4.  It  con- 
sists of  a  watiff  trough,  B,  above  which  a  pair 
of  heavy  wooden  squoezing  rollers,  a,  a,  are  sup- 
ported. Two  strands  of  cloth  are  wsished  simul- 
taneously ;  they  enter  the  aachiQe  at  tbe  ends, 
pass  between  the  squeezing  rollors,  then  ronnd 
Uie  roller  B  in  the  water  tiougb,  again  between 
the  Totlers  t,  a,  and  thus  travel  spindly  towards 
the  centre  of  the  machine,  whence  they  are 
drawn  out  by  a  winch  and  pQed  on  the  floor. ' 
A  oonituit  stream  of  water  from  the  main 
0  enters  at  the  centre  of  the  trough  by  the 
tap  x,  the  dirty  water  flowing  out  at  both  ends  ;  i 
c,care  wooden  guide  p^s  to  sepArate  the  several  I 


no.  4 

strands  of  cloth ;  s,  9  are  strong  brass  rings  or 
'  pot  eyes '  through  which  tbe  cloth  enters 
the  machine,  and  which  can  be  set  at  any  angle 
to  regulate  its  tension  ;  K  and  w  are  the  screws, 
levers,  and  weights  for  regulating  the  pressure  of 
the  squeeung  rollers  a^uost  each  other.  The 
action  of  this  machine  is  such  that  the  cloth  is 
continuously  being  soaked  with  water  and  then 
squeezed,  thus  causing  a  vigorous  stream  of 
water  to  flow  down  the  upward-moving  strands 
of  cloth. 

2.  Lime-boil  (lime-bowk,  bucking,  bowking). 
The  pieces  are  ruu  through  milk  of  Lme  supplied 
to  a  washing  machine  of  amall  dimensions — 
generally  termed  the  '  liming  machine  ' — and  are 
at  once  drawn  by  winches  into  the  lime  kiers, 
carrying  with  them  the  lime  they  have  absorbed. 
The  cloth  is  plaited  in  regular  folds  and  well 
tiamped  down   by  boys,  who  enter  the  kiers. 


605 


BLEAGHINO. 


After  adding  the  neoessaiy  amonnt  of  water, 
the  boiling  and  oironlation  of  the  liqnor  takes 
place  as  uready  desoribed  in  the  case  of  tiie 
ley-boil  of  ootton-yam  bleaching. 

The  lime-boil  has  for  its  object  the  decom- 
position of  the  fatty,  waxy,  and  resinous  im- 
purities present  in  the  cloth.  Though  not 
removed,  but  adhering  still  to  the  fabric  in  the 
form  of  lime-soaps,  their  altered  condition  facili- 
tates their  removal  by  the  subsequent  processes. 
The  starch  of  the  size  is  removed,  and  the 
colouring  matter  of  the  fibre  is  modified.  Lime 
is  preferred  to  caustic  soda  because  it  is  cheaper, 
and  much  more  effective  in  saponifying  neutral 
fatty  matter  than  the  caustic  or  carbonated 
alkidis;  indeed,  with  the  exception  of  barium 
hydroxide,  it  seems  to  be  the  most  energetic 
saponifying  agent  which  could  be  used  in  cotton 
bleaching. 

It  is  very  essential  to  have  a  sufficiency  of 
water  in  the  kier,  so  that  it  stands  at  least  about 
2  feet  above  the  false  bottom ;  otherwise  the 
cloth,  either  at  the  top  or  bottom  of  the  kier,  is 
very  apt  to  be  tendered,  probably  because  it 
becomes  oxidised  by  the  action  of  the  steam 
upon  the  cloth  in  ito  limed  condition.  On  the 
other  hand,  an  excess  of  water  in  the  kier  is  to 
be  avoided,  since  then  the  doth  is  apt  to  float 
and  become  entangled,  or  damaged  by  rubbing 
against  the  sides  of  the  kier  during  the  boiling. 
When  closed  hich-preesure  kiers  and  live  steam 
are  employed,  uie  increase  in  volume  of  liquor 
by  the  condensation  of  the  steam  must  be  taken 
into  account,  and,  if  necessary,  a  little  liquor 
must  be  allowed  to  escape. 

Of  the  several  varieties  of  kier  which  have 
from  time  to  time  been  intfoduoed  in  practice, 
mention  may  be  made  of  '  BarlowU  kiera* 
These  axe  always  worked  in  pairs,  and  so 
arrai^ged  that  the  top  of  one  kier  is  connected  by 
a  pipe  with  the  bottom  of  the  other ;  the  pipes 
wmdi  enter  at  the  top  and  centre  of  each  kier  are 
continued  as  perforated  pipes  or  *  distributors ' 
to  a  little  above  the  false  bottom,  and  then  to 
the  bottom  of  the  kier  as  a  stay.  Both  kiers 
having  been  charged  with  cloth,  the  necessary 
amount  of  water  is  run  into  one  kier  only ;  high- 
pressure  steam  is  then  admitted  at  the  top,  and 
the  liquor  forced  out  below  enters  the  distributor 
of  the  other  kier  at  the  top  and  permeates  the 
cloth.  When  all  the  liquor  has  been  thus 
transferred,  the  taps  are  reversed  so  that  the 
steam  forces  iJie  liquor  in  a  similar  manner  back 
into  the  first  kier.  This  alternating  process  and 
circulation  of  the  liquor  is  continued  for  about 
seven  hours. 

Pendlebury's  arransement  of  kiers  is  rae- 
oisely  similar  to  that  of  Barlow,  the  onl  v  differ- 
ence being  that  one  kier  \b  smaller  and  serves 
only  to  hold  the  liquor  each  time  it  is  forced 
through  the  cloth  contained  in  the  larger  kier. 
The  arrangement  is  cheaper,  more  economical 
as  regards  space  required,  and  is  suitable  for 
small  requirements. 

In  the  vacuum  Icier  of  Mason  and  others, 
the  circulation  of  the  liquors  is  effected  by  means 
of  a  pump.  After  filling  the  kier  with  cloth, 
the  air  is  pumped  out  and  the  boiling  liquor  is 
then  admitted ;  in  this  manner  a  more  perfect 
penetration  of  the  material  by  the  liquor  is 
obtained. 

The   injector  kier  of  Mather  and   Piatt  is 


shown  in  Fig,  6.  a  is  the  kier  filled  with  doth  ; 
B,  B  are  the  steam  pipes;  o  is  the  injector;  and 
D  the  circulating  pipe ;  F  is  the  liquor  pipe  by 
which  water  or  other  liquor  is  admitted ;  b,  ■  is 
the  draw-off  valve  and  waste  pipe.  When  the 
kier  has  been  suitably  filled  with  cloth  and  liquor, 
steam  is  turned  on,  and,  by  the  action  of  the 
injector  0,  the  liquid  is  withdrawn  from  the  Ider 
below,  forced  up  the  pipe  x>,  and  spread  over 
the  cloth  at  o.  Temporarily  collecting  at  H, 
the  liquor  is  gradually  drawn  through  the  doth, 
and  in  this  manner  a  continual  circulation  of 
liquor  is  maintained. 

3.  Lime-sour   (grey-sour).    After  the   lime- 
boil' the  pieces  are  washed,  then  passed  through 

I  a  washing  machine  fed  with  dilute  hydrochloric 
I  aoid,  and,  if  convenient,  at  once  washed. 
'  The  object  of  the  lime-sour  is  to  decompose 
the  insoluble-lime-soaps  fixed  on  the  doth  during 
the  lime-boil,  and  to  dissolve  and  remove  the 
lime,  also  any  iron  or  other  metallic  oxides 
present.  Experiments  by  A.  Scheurer  show  alao 
that  the  use  of  the  lime-sour  makes  it  less 
essential  that  complete  saponification  of  the 
fatty  matter  should  t(dce  place  during  the  lime- 
boil  than  would  be  the  case  if  it  were  omitted. 
This  is  so  because  the  free  fatty  add  liberated 
during  the  lime-sour  areatly  facilitates  the 
saponification  of  an^  undecomposed  neutral  fat 
during  the  succeeding  ley-boi^  since  the  soap 
which  the  fatty  acid  then  forms  emulsifies  the 
neutral  fat  and  exposes  it  to  the  action  of 
the  alkali  employed!  Hence  the  adoption  of 
the  lime-sour  is  equivalent  to  shortenmg  the 
time  of  the  lime-boiL  A  continual  flow  of  fresh 
dilute  acid  into  the  machine  must  be  maintained, 
and,  since  it  is  rapidly  neutralised  by  the  lime,  it 
is  wdl  to  ensure  a  constant  slight  acidity  of  the 
liquor  by  occasionally  making  acidimetrioal  tests. 
Hydrochloric  acid  is  preferred  to  sulphuric  acid, 
because  it  gives  the  more  soluble  oaldnm 
chloride.  The  soured  cloth  should  never  be 
permitted  to  remain  long  exposed  to  air, 
especially  air  currents,  otherwise  the  aoid  is  apt 
to  concentrate  in  the  exposed  portions  and  thus 
tender  the  fibre. 

4.  Ley-boiL  This  operation  takes  place  in 
the  same  kind  of  kiers  as  are  used  for  tne  lime- 
boil.  The  fatty  acids  resulting  from  the  decom- 
position of  the  lime-soaps  during  the  grey-sour, 
also  the  brown  colouring  matters,  are  removed 
during  this  operation.  Its  special  feature  is 
the  use  of  resm-soap,  which  greatly  facilitates 
the  removal  of  fat^  matter  hj  exercising  a 
purely  mechanical  emulsive  action,  ttie  alkali 
present  being  then  able  more  readily  to  saponify 
the  emulsified  fats,  particularly  tnose  neutral 
fats  which  perchance  have  escaped  the  action  of 
the  lime-boiL  Ordinary  soft-soap  acts  in  a 
dmilar  manner,  but  resin-soap  is  cheaper  and 
better.  A.  Scheurer  finds  by  experiment  that^ 
after  caustic  lime,  the  most  rapid  saponification 
of  a  neutral  fat  spotted  on  a  piece  of  calico  is 
effected  when  boiling  under  pressure  at  120**  C, 
by  a  solution  containing  10  grams  anhydrous 
caustic  soda  and  2(  grains  resin  per  litre.  In- 
creasing the  amount  of  resin  does  not  hasten 
saponification,  though  this  is  done  by  increasing 
the  vdocity  of  the  circulation  of  the  solution. 
Indeed,  wuh  circuUUion  even  a  more  rapid  sa- 
ponification is  effected  with  caustic  soda  and 
resin  than  with  hme. 


BLEACHING. 


807 


nw  pnlimiiury  ahoii  boilii^  with  coda  uh,  |  <teun-he«t«d    copper    oylindeis,    and    folded, 

whjoh  ii  wimetiinea  replseed  b;  laenlj  Boaking  The   time   Dnully   reqmred   to    complete   the 

the  oloth  in  a  weak  solution  of  aods  ('  tweet'  madder  bleach  is  foar  to  five  days. 
ening '),   prevent*   tendering   of   the   cloth   by  Tbs  BttAVt  blMCb.    In   market   bleaching 

neutral isiiig  an?  traoee  of  acid  left  in  by  reuon  the  object  ia  unply  to  give  a  brilliant  while 

of  insufficient  washing  after  touring.     The  boil-  appeantncetothecuicoorotbersimilarmateriki, 

ing  with  Boda-ash  after  the  reein-boil  ia  for  the  to  fit  them  for  immediate  sale  in  the  market 

purpose   of   completing   the   removal   of   fatty  as  Snished  white  goodi.     It  ia  not  necessary  to 

mattera  and  an;  undiMolved  raain,  which  other-  have  the  calico  '  well  bottomed  ' — i.e.  cleansed 

wise  give  rise  to  brown  itains.     Immediate  re-  from  all  colour-attracting  impurities,  aince  no 

moval  of  the  cloth  from  the  kier  and  washing  subsequent  dyeing  or  printing  u  intended.     The 

ia  necessary  to  prevent  the  nroduction  of  iron  ooerations  are  for  the  moat  nart  

S.  ChtHkkitig.  Tl 
bleaching-powder  tolu 
ing  machines  of  the  or 
with  stone  instead  of 
of  their  greater  durabil 
takes  idsoe  eesentiall; 
or  eipomre  to  air  of  tl 
solution  of  bleaching  f 
of  the  air  liberates  hy 
n  the  presence  of  the 


tracee    of    coloi 


It  is  necessary  to 
the  use  of  strong  sol 
of  bleaching  powder, 
wise  the  fibre  itaelf 
tacked,  oiy cellulose 
produoed ;  and  even 
cotton  is  not  tendered 
by  it  is  still  apt  to  a 

qneut  operati 
by  the  calii:!.- 
.  printer,  e.g.  steam' ~ 
ing,  or  to  prodoce  % 
UDeven  shades  in  ^ 
dveinir, 

6.  WhiU-sour. 
operation  ia  similar 
lime-sour  already  des 
except  that  sulphur 
is  usually  em^oyed 
of  hydrochloric  acid, 
because  ol  its  lowe 
Its  object  is  to  deci 


undecomposed  b1< 
powder,  lime,  iron,  i 
oxidised  colouring  m 

7.  The    final     wuhing 
must   be   as    thorough    as  ,     ,    „ 

possible  in  order  to  ensure  the  removal  ol  all 
traces  of  acid,  which,  if  left  in  the  cloth,  would 
inevitably  tender  portions  of  it  during  the  drying  | 
process.  After  washing,  the  cloth  ia  roecially  , 
squeezed  by  passing  through  a  pair  of  heavy 
wooden  rollers,  or  through  the  modem  grooved 


wooden  rolfers,  or  through  tl „- -  ^ 

brass  roller  and  disc  machine  of  W.  Birch. 
The  chain  of  cloth  then  pas»s  ia  a  honiont- 
loosely  hanging  position,  between  a  pair 
rapidly  revolvuig,  double- armed  winche« 
scutchers,  which  effectually  shake  out  < 
twi«t  from  the  strand.  Thus  opened  ont  to  ■ 
full  width,  the  cloth  ia  dried  by  paeung  o 


2.  Lime-iouT.     Hydrochloric     acid     (sp.gr. 

l-Ol);  steep  2-4  hours  ;   wash. 
3    F'rii      Uy-hoa   or  grty-boU.     240   kiloe, 

caustic  soda  (solid),  about  37.000  Utres 

water;  boil  12  hours;   wash. 
4.  ChrmicHng.     Bleaching-powder    solution 

(BD.irr.  1-005);  steep  2-*  hours  ;  wash. 
6   SreJid  Itv-boil  or  ahiU-boU.    240  kilos. 

»od»  ash,  about  37,000  litres  water ; 

boil  12  hours;  wash. 


OM  BLEA( 

6.  While-lour.     Sulphurio  acid  (ip.gr.  1-01); 

ateep  2-4  hours ;   waah. 

7.  Tint  with  blue ;  iqueeie  dry. 

HoTo  or  leaa  elaborate  finialiiiig  owrations 
follow — e.g.  stMohing,  calenderine,  Deetling, 
atentering,  &o.  Boms  bleachers  introduce  a 
wbite-iour  botireeii  operatioiu  4  and  0,  and  a 
second  chemicking  betweea  operations  6  and  6. 
The  absence  ot  resin-soap  in  the  lej- boils  is 
charaotoristio. 

Tba  Tarkej-rad  UeMh.  This  ia  merely  a 
curtailment  of  the  foregoing  processee,  and  is 
spedallj  intended  for  yam  or  oloth  to  be  sub- 
sequentlj  dyed  plain  afizarin-red  or  Turkey-red. 
In  it  the  operation  of  singeing  and  the  amplication 
of  blaachtng  powder  ate  omitted,  since  they 
liiminiBh  the  fulneaa  and  brillianoy  of  the 
Tntfcey-red  dye  ;  the  use  of  the  latter  is  to  be 
aroided,  beoanw  it  give*  rise  to  the  ^oduotion 
of  ozycellnlose.  The  ate  of  remn-soap  is  un- 
neoesaary,  and  the  process  is  limited  to  the 
following  operations : — 

1.  Wash. 

2.  Boil  in  water  2  hours  j  waah. 


(■P-gr. 


3.  Leu-lMa. 

lit  00     litres     caustic     soda 
I'3S),   about   3000   litres    ' 
boil  lO  horns  ;   wash. 

2nd.  TO   litree   oaastic    soda    (sp.   gr. 
IZS);  ditto,  ditto. 

4.  SoitT.    Sulphuric  aoid  (sp.gr.  I-Ol) ;  steep 

B.  Wash  well  and  dry. 

The  above  qoantities  of  materials  ai«  in- 
tended for  2000  kilos,  cloth,  with  loir-presEnre 

The  itAsmw-kla  blttehlng  prmeat.  The 
bleaching  proceesoa  previously  described  have 
been  in  vogne  with  little  change  dnriag  the 
last  forty  years ;  minor  modlGcations  have 
aettainly  bosn  introduced,  but  the  chief  im- 
provements have  always  beeo  in  leepect  of  the 
mechanical  appliancea  employed. 

In  1S83  Thompson  patented  a  bleaching 
process  in  which  the  goods  oontained  in  an 
air-tisbt  kier  are  submitted  to  the  action  of 
bleaching- powder  solution  and  of  carbonic  aoid 
alternately. 


FlO.  6. 
In  18S4  W.  Mather,  of  the  Erm  of  Mather  & 

Piatt,  Uancheeter,  devised  an  improved  arrange- 
ment in  which  the  calico  could  be  passed  con- 
tinuonaly  through  chambers  or  tanks  containing 
the  two  necessary  agents  mentioned. 

The  Bo-oalled  '  Ataihtr-Thomjuum  process 
results  from  a  combination  of  the  two  proeeaaee 
here  indicated.  With  regard  to  the  principles 
of  the  prooeBS  there  is  nothing  new,  for  the 
application  of  carbonic  acid  in  connection  with 
bleaching-powder  solution  was  patented  by 
P.  F.  Didot  in  1S65,  nhile  the  steaming  of  goo^ 
impregnated  with  alkali  was  patented  as  far 
back  as  1800  by  J.  TumbuR 

The  novelty  consists  essentially  in  the  ma- 
chinery employed,  by  which  the  duration  of  the 
bleaching  process  is  very  much  shortened,  and 
other  material  advantages  are  gained. 

In  the  following  year  Mather  introduced  the 
80-oalled  lUamer-kier,  in  which  the  goods, 
previously  impregnated  with  dilute  caustic  soda, 
were  submitted  to  the  action  of  low.pressure 


The  steamer-kier  oonsista  of  a  strong  w 


mght- 


iron  horizontal  boiler,  one  end  of  which  can 
be  dosed  by  a  specially  constructed  sliding  door. 
At  the  side  of  the  kier  stands  a  centtifogal 
pomp  connected  with  the  top  and  bottom  of 
the  kier,  and  also  with  liquor  tanks  beneath, 
so  that  eitkei  boiling  water  or  dilute  caustic 
alkali  solution  can  be  sprinkled  on  and  cir- 
culated through  the  goods.  Figs.  6  and  7  show 
the  general  disposition  of  the  steamer- kier. 

Two  waggons  of  cloth  having  been  run  into 
the  kier,  and  the  door  closed,  steam  is  admitted 
till  the  pressure  reaches  a  maximum  of  4-0  Iba. 
During  the  steaming  or  boiling  process,  a 
continual  sprinkling  of  the  cloth  with  dHute 
caustic  soda  (sp.gr.  1-01-1-02)  'is  maintained, 
in  order  to  keep  the  cloth  veil  saturated  with 
liquid,  and  thus  prevent  oxidation  and  oonse- 
quent  tendering  of  the  fibre  by  the  action  of  the 
steam.  The  ezcdlent  circulation  of  the  liquors 
in  the  steameT'lder  ia  a  noteworthy  and  most 
important  feature,  since  it  greatly  faoiliUtes  t^e 
saponification  of  the  fatty  matters  on  the  cotton. 
After  steaming,  the  liquor  is  run  off,  the.kier 
I  is  almost  filled  with  hot  water,  and  this  is  cir- 


BLEACHING. 


600 


tmlated  through  the  cloth  by  means  of  thecentri-  Idecoinposition  of  any  insoluble  fatty  acid  com 


f  ugal  pump  foF  one  hour.  A  similar  washing  with 
fresh  not  water  takes  place  during  another  hour. 

Each  kier  is  provided  with  two  pairs  of 
waggons,  so  tiiat  while  the  goods  in  one  pair  are 
being  steamed,  the  other  pair  can  bo  emptied 
and  refilled  with  cloth  ready  to  be  steamed.  In 
this  manner  the  operation  of  steaming  is  ren- 
dered as  continuous  as  possible  and  a  very  great 
saving  of  time  is  e£fected. 

The  following  details  have  been  furnished  by 
H.  Koeohlin,  of  the  Loerrach  Printworks  : — 

To  effect  the  madder  "bleach  by  the  tieamer 


pounds  present  in  the  grey  cloth ;  it  removes 
calcareous  or  other  mineral  matter  soluble  in 
acids,  and  modifies  any  starohv  matter  present, 
probably  rendering  it  more  soluble.  The  addi- 
tion of  the  small  proportion  of  the  reducing  agent 
bisulphite  of  soda,  along  with  the  caustic  soda 
in  the  preparing  process,  is  intended  to  prevent 
any  oxidation  and  consequent  tendering  of  the 
cotton  during  the  steaming  process.  The  use  of 
resin-soap  along  with  the  caustic  soda,  combined 
with  the  perfect  circulation  of  the  Uquor,  is 
very  material  to  the  success  of  this  method  of 


hier  process,  the  continuous  bleach  with  the '  madder  bleachin^for  reasons  already  stated, 
application  of  carbonic  acid,  &o.,  is  omitted,  the        According  to  H.  Koeohlin,  this  method  gives 
older  method  of  ohemiokin^  and  souring  being  a  perfectly  satisfactory  bldkch.    The  white  is 
preferred.    Those  who  consider  the  lime- boil  as   not  permanently  stained  in  an  alizarin  dye- bath, 
essential  may  apply  it  equally  well  by  means  of  and  does  not  become  yellow  on  steaming, 
the  steamer-kier. 


The  operations  in  this  case  are  as  follows : — 

1.  lAmt-haU  (or  $team).     Run  throush  milk 

of  lime,  50  grams  per  litre,  and  pile  in 
steamer- waffgon  ;  boil  in  steamer-kier  6 
hours  at  10^ lbs.  pressure,  circulating 
2000  litres  water.  Wash  in  kier  with 
hot  water. 

2.  8<mr.    Sour  as   usual   with   dilute   HGl 

(sp.gr.  1-015);  pile  2-3  hours,  and 
wash. 

3.  Ley-prtpart.     Pass  through  NaOH  solu- 

tion (sp.gr.  1  -005-1 01).  heated  to  70°  C, 
and  pile  in  steamer- wa^on. 

4.  Ley-boit  {or    steam).    B<m    6    hours    in 

steamer-kier  at  10  lbs.  pressure,  with 
circulation  of  resin-soap  liquor:  40 
kilos,  soda  ash,  20  kilos,  resin,  1000 
litres  water.  Wash  four  times  (^-1 
hoiir  each  time)  with  boiling  water,  and 
finally  with  cold  water,  in  kier. 

5.  Chemicking.     Pass  as  usuiil  through  di- 

lute bleaching-powder  solution  (sp.gr. 
1-0025);   wash. 

6.  Sour,     Pass  as  usual  through  dilute  sul- 

phuric  acid  (sp.gr.  1*01);    wash  and 
dry. 
Perfectly  satisfactory  results,  however,  are 
obtained   by  even  omitting  the  lime-boil  and 
proceeding  as  follows  : — 

1.  Sour,  Pass  as  usual  through  dilute  H,S04 
(sp.gr.  1*015) ;    pile  2-^  hours ;    wash 
and  squeeze. 
Ley '  prepare. 


STEAM  6AUCC 


Fio.  8. 


2. 


A  noteworthy  invention  of  Dr.  Q.  Lunge  is 

the  application  of  acetic  acid  in   connection 

I  with  bleaching  powder,    in    place    of    mineral 

,        ^  Pass    through    following   acids  or  carbonic  add.     It  can  be  applied  im- 

solution  at  70°  C. :  20  litres  bisulphite  '  mediately  before  or  after,  or  even  along  with, 

of  soda  (sp.gr.  1-3),  20  kUos.  NaOH   the  solution  of  bleaching  powder.     It  liberates 

hypochlorous  acid   with  formation  of  soluble 

When  the  hypochlorous  acid 


(solid  72  p.c.),  1800  litres  water ;  pile  in 
steamer- waggons. 

3.  Ley^boil    {or    steam).    Boil    in    steamer- 

kier  6-8  hours  at  10  lbs.  pressure,  with 
circulation  of  resin-soap  liquor:  20 
kilos.  NaOH  (solid  72  p.c.),  40  kilos, 
soda  ash,  20  kilos,  resin,  2000  litres 
water;  wash  4  times  (^1  hour  each 
time)  with  boiling  water,  and  onoe 
with  cold  water  in  Kier. 

4.  Chemicking,     As  above. 

5.  Sour.     As  above ;   wash  and  dry. 

With  the  exception  of  the  employment  of 
the  steamer-kier  and  the  use  of  bisulphite  of 
soda,  this  process  is  essentially  the  same  as  that 
employed  for  many  vears  with  success  by  Messrs. 
Guillaome  Frdres  of  St.  Denis. 

The  preliminary  souring  process  effects  the 

Vol.  I.— T. 


calcium  acetate. 

exercises  its  bleaching  power,  it  gives  up  oxygen 
and  produces  hydrochloric  acid,  which  immedi- 
ately acts  upon  the  calcium  acetate.  In  this 
manner  the  acetic  acid  is  reproduced,  and  is  thus 
ready  to  decompose  fredi  portions  of  calcium 
hypochlorite. 

Hadfield  and  Sumnei  patented  a  process  in 
which  the  doth,  after  having  been  impregnated 
with  a  solution  of  bleaching  powder,  ia  passed 
through  a  box  containing  acetic  acid  vapour. 

A  solution  of  sulphurous  ac^  has  been  used 
by  some  bleachers  for  the  final  souring  process 
in  place  of  sulphuric  add,  over  which  it  possesses 
the  advantage  of  being  an  antichlor,  in  conse- 
quence of  its  reducing  action. 

The  Walsh  Her,     in  this  kier,  shown  in  Figs. 

2  B 


810  BLBA( 

6  »nd  0,  which  is  vorv  laiacly  naed,  the  boiliiiK 
Uqnot  ii  oiroolBted  bj  meant  of  s  oeatrifu^J 
pump,  uid  it  ia  befttad  in  a  tpeoiaJ  koabng 
urangemeot  outsida  the  boiling  kiet. 

In  the  Benti-EdmaUm  and  in  the  TagUani- 
Riganumli  kiers  the  boiling  operation  ia  a  oon- 
tinuoiu  procoBi.  lew  pressure  ia  uBually 
employed,  and  the  impregnation  of  ttie  pieoea 
'\  the  boilins  liquor  in  tbe  lower  put  of  the 


plaited  into  wooden   boxes,  in  whioh  thej*  are 

allowed  to  lie  for  aome  hours. 

Piece  goods,  sach  u  heavy  twilla,  ka., 
whiob  are  frequently  damaged  (oreaaed)  in  or- 
dinary bleaching  in  the  rope  form,  are  treated 
in  the  open  width.  Special  Ider*  have  been 
coDstnict^  for  this  purpose,  the  principal  one 
being  the  Jackton-Hurd  kier  (Fig.  10). 


Pio.  10. 

PrcTioiu  to  boiling  in  tbia  kiet  the  doth  is 
impK^nated  with  caustic  sodu  ley,  which  Iim 
been  nsed  in  a  former  boiling,  in  a  spe(!1al 
batching  machine.  In  this  the  oloth  tmvola 
tiTor  a  pei4orat«d  drum,  uid  Uie  «oda  ley  ia 
forced  through  it  hy  means  of  steam,  which  is 
blown  agaioat  it  whilst  it  travels  over  the  drum. 
Ultimately,  the  cloth  ia  wonnd  tightly  and  evenly 
into  a  batch. 

Thia  batch  is  now  placed  on  a  wanon, 
which  is  transferred  to  the  horizontal  b^ing 


Specisl 
ot  which  t 


IriTing  gear  u 


another  batching  roller,  passing  over  a  heavy 
perforated  drum  whioh  rests  on  both  batches, 
rhe  eauatie  soda  liquor  is  ciroulated  by  meuia 
of  •  oentrifugal  pump,  and  ia  showered  over  the 
eloth  dnring  lU  paMsge  over  the  perforated  drum. 

In  this  Ider  the  cloth  ia  usually  boiled  nnder 
high  ptesanre  (about  4S  lbs.). 

In  the  preparatiOD  of  sodium  \ypocldariU 
solution,  by  eleotrolyaing  a  solution  <^  common 
salt  two  types  of  processes  are  employed,  one  in 
whioh  the  products  of  eleotrolyais,  viz.  sodium 
and  chlorine,  are  not  allowed  to  combine,  and 
the  other  in  whioh  they  are  allowed  to  combine 
to  form  sodium  hypochlorite 

2NaOH-fa,-NaOa+Naa+H,0. 
The  latter  process  oomes  chiefly  into  considera- 
tion as  regsjda  the  bleaching  of  textjla  materiais. 

The  appBTatUB  used  may  be  divided  into  two 
classes,  Uie  one  in  whioh  electrodes  made  of 
platinum  -  iridium  an  nsed,  and  the  other  in 
which  carbon  electrodes  (highly  comprcsitid 
grajdtite)  are  employed. 

In  the  KellneT  eleotrolyMr,  which  b«longa  to 
the  former  kind,  a  centrifugal  pump  is  employed 
by  means  of  whioh  the  salt  aolntion  is  repeatccUy 
passed  through  the  apparatus  until  it  oontuns 
from  3  1«  G  grama  of  active  chlorine  per  liti«. 

In  the  Haas  and  Oettel  electrolyser,  whiiA 
belongs  to  the  latter  kind,  the  salt  solntiMl  it 
electrolysed  until  it  contains  from  10  U>  IS 
grami  of  active  chlorine  per  litre. 

Powerful  oiroulatioa  of  the  salt  solution  is 
obtained  by  means  of  the  hydrogen  gas  evolved 


ring  electrolysing. 

Bwachina  by  mea  _  _    _ 

pared  hypoonlorito  solution,  although  employed 


Bleaching  by  means  of  eleotrolytioally  [ve- 


advantage  in  special  cases,  such  as  tbe 
bleaching  of  oope.  is  not  commonly  practised, 
because  it  is  more  expensive  in  its  applioatioa 
than  bleachii^  powder. 

The  statement  that  ao  electrolytioaUy  pre- 
pared bloaching  aolntion  it  more  effective  than 
a  solution  of  ueaohing  powder  containing  the 
■ama   amount   of   active    chlorine^  cennot    be 

firmed  in  practice. 

Ptrmanganale  of  polaih,  rodium  penaide, 
and  hydrogen  peroaide  give  eioeUent  iMolta  in 
bleaomng.  Their  price,  at  compared  with 
bleaching  powder,  is,  however,  in  meat  instances, 
prohibitive. 

The  history  of  ootton  bleaching  may  b« 
briefly  said  to  comprise  the  following  noteworthy 


2.  The  boiling  with  carbonate  of  toda  instead 

oaoatic  soda,  after  the  lime-boil,  introdooed 

im   America  about   1837.     A  mote  eSeotoa] 

decomposition    of    the    lime-toapa    was    Ouu 

obtained. 

8.  The  adoption  of  the  lime-tour,  as  proposed 
by  A.  Scheurer-Rott  in  1S37. 

4.  The  use  of  resin-soap  in  the  ley-boils 
about  the  same  period. 

C.  The  introduction  ot  high-pressure  boiliiig 
kier*  about  1844. 

6.  The  use  of  caustic  alkali  and  teain-scup 

conjunction  vrith  the  steamer-kior,  to  the 
eicluiioQ  of  the  lime-boil,  in  1883-84. 

linw  UeaeUng.  Since  the  retted  flas  fibre 
containf  a  much  larger  proportion  of  natural 


BLEACHING. 


611 


impurities  than  cotton,  e.y.  25-30  p.c.  of  pectic 
acid,  beside  fatty  matter,  &c.,  linen  is  not  so 
readily  bleached  as  cotton.  In  the  main,  how- 
ever, the  methods  adopted  for  the  two  fibres  are 
the  same.  Linen  is  bleached  in  the  form  of  yam, 
thread,  or  cloth. 

Linen-yarn  bleaehlng.  Very  frequently  linen 
yam  ia  only  partially  bleached,  the  process  being 
completed,  if  necessary,  when  the  yam  has  been 
woven  into  cloth. 

The  following  operations  are  employed  in 
order  to  obtain  'half -white'  or  cream,  with  1600 
kilos,  yam,  usine  low-pressure  kiers : 

1.  Ley-hoil    Boil  3-4  hours  in  a  solution  of 

160  kilos,  soda  ash  ;  wash  and  squeeze. 

2.  Chemick  {red).    Reel  1  hour  in  bloaching- 

]>owder  solution,  sp.gr.  1*0026 ;  wash. 

3.  Sour,    Steep  1  hour  in  dilute  sulphurio 

aoid.  sp.gr.  1*005:   wash. 

4.  Ley-hoil  {icald).    Boil  1  hour  in  a  solution 

of  30-75  kilos,  soda  ash ;  wash. 

5.  Chemiek.    Reel  in  a   dilute  solution  of 

bleaching  powder,  sp.gr.  1*0025 ;  wash. 

6.  Sour,    Steep  1  hour  m  dilute  sulphurio 

acid,  sp.er.  1*005 ;  wash  well  and  dry. 

If  the  ysm  snould  be  bleached  more  com- 
pletely, then  operations  4,  5,  and  6  are  repeated 
two  or  three  tunes,  as  may  be  found  necessary, 
with  this  difference,  that  between  4  and  6  the 
yam  is  *  grassed,'  t.e.  exposed  in  the  Geld  to  the 
action  of  the  air,  light,  and  moisture,  for  several 
days.  By  introducing  this  very  gentle  method 
of  bleaclung,  the  full  strength  of  the  fibre  is 
better  maintained. 

The  various  operations  are  conducted  in 
appeuratus  precisely  similar  to  that  employed  in 
the  bleaching  of  cotton  yam,  except  in  tne  opera- 
tion of  chemickinff.  Although  steeping  under  the 
sieve  in  dilute  bkaching-powder  solution  might 
well  be  employed,  it  is  usual  to  suspend  the 
hanks  of  linen  yam  on  reels  in  such  a  manner  that 
they  are  only  partially  immersed  in  the  solution 
contained  in  a  shallow  tank.  As  the  reels  revolve 
the  yam  becomes  thus  alternately  impregnated 
with  the  solution  and  exposed  to  the  air.  The 
liberation  of  hypochlorous  aoid  by  the  carbonic 
acid  of  the  air  is  advantageous,  and  the  bleach 
is  more  effective  and  regular. 

The  application  of  acetic  acid,  as  proposed 
by  Lunge,  instead  of  this  exposure  to  air,  may 
here  be  strongly  recommended,  since  then  no  in- 
soluble lime  salt  is  fixed  on  the  fibre,  and  the  sub- 
sequent sourinff  is  reduced  to  a  minimum. 

To  avoid  the  presence  of  caustic  lime,  some 
bleachers  use  hypochlorite  of  magnesia,  as  pro- 
posed by  Hodge,  instead  of  bleaching  powder. 

Unen-eloth  bleaching.  The  old  method  of 
bleachins  linen  doth  consisted  in  alternately 
boiling  we  fabric  with  solutions  of  sodium  car- 
bonate and  exposing  on  the  grass,  succeeded  by 
souring,  and  mbbinff  with  solutions  of  soap, 
l^e  modem  methoc^  adapted  from  that  em- 
ployed for  calico,  is  given  in  the  following 
r^sumd.  It  is  intended  for  1500  kilos,  brown 
Unen,  using  low-pressure  kiers. — 

1.  Lime-boil.    Boil  14  hours  with  125  kilos. 

lime,  2000  litres  water ;   wash. 

2.  Sour.    Steep  2-6  hours  in  dilute  hydro- 

chloric acid,  sp.gr.   1-0025;    wash  in 
stocks,  turn-hank,  wash. 
3»  Ley-hoiU.    First,   boil   8-10  hours   with 
2000  litres  water  containing  resin-soap ; 


30  kilos,  oanstio  soda  (solid),  30 
kilos,  resin,  previously  boiled  together 
with  water;  secondly,  boil  6-7  hours 
with  2000  litres  water,  15  kilos,  caustic 
soda  (solid),  previously  dissolved; 
wash. 
i.  Expose  in  field  2-7  days  according  to  the 
weather. 

5.  Chemick.    Steep    4-6    hours    in    dilute 

bleaching-powder       solution,       sp.gr. 
1*0025;  wash. 

6.  Sour.    Steep  2-3  hours  in  dilute  sulphurio 

acid,  sp.gr.  1*005  ;   wash. 

7.  Ley-hoU   {kM).     Boil   4-5    hours    with 

2000  litres  water,  8-13  kilos,  caustic 
soda  (solid) ;    wash. 

8.  Expose  infield  2-4  days. 

0.  Chemick.    Steep    3-5    hours    in    dilute 

bleaohing-powdcr       solution,       sp.gr. 

1*0013:   wash. 

At  this  stage  the  cloth  is  examined;  those 

pieces  which  are  sufficiently  bleached  are  soured 

and  washed,  the  rest  are  further  treated  as 

follows : — 

10.  Bub  with  rubbing  boards  and  a  solution 

of  soft  soap. 

11.  Expose  infield  2-4  da3rs. 

12.  Chemick.    Steep    2-4    hours    in   dilate 

bleaching-powder       solution,       sp.gr. 
1-0006;   wash. 

13.  Sour.    Steep  2-3  hours  in  dilute  sul- 

phuric acid,  sp.gr.  1*005. 

14.  Wash,  squeeze,  and  drv. 

If  the  linen  is  not  brown,  but  made  of  ysm 
already  partly  bleached,  the  above  process  is 
much  cuitailea,  and  weaker  liquors  are  employed. 

The  kiers,  chemickinff  ana  souring  machines 
are  the  same  as  those  usea  in  ootton-doth  bleach- 
ing. The  washing  is  done  in  the  so-called  wash- 
stocks  or  by  slack- washing  machines.  Hie  latter 
are  very  similar  to  the  cotton- washing  machines, 
the  chief  difference  being  that  the  water  tank  is 
divided  into  compartments,  each  of  which  holds 
a  few  yards  of  slack  cloth  forming  each  strand, 
before  it  passes  through  the  squeezine  rollers. 

The  *  rubbing  '  referred  to  is  for  the  purpose 
of  removing  mechanically  any  remaining  brown 
particles  of  ligneous  matter  termed  ^spnts.'  It 
consists  in  passing  the  chain  of  cloth  through  a 
solution  of  soap,  and  then  immediately  between 
a  pair  of  horizontal,  corrugated,  heavy  boards ; 
the  upper  board  rests  loosely  upon  the  lower 
one,  and  moves  lengthwise  to  and  fro,  while  the 
pieces  pass  between  them  at  right  angles. 


The  operation  of  '  tum-hanking  *  consists  in 
disentan^^ling  the  pieces  after  they  have  been 
washed  m  the  stocks,  and  then  refolding  them 
for  a  further  wash,  thus  ensuring  a  thorough 
deansing  of  every  portion  of  the  cloth.  When 
slack-wuhing  machines  are  employed,  the 
operation  is  of  course  not  necessary. 

The  chemistry  of  linen  bleaching  is  essenti- 
ally the  same  as  that  of  bleaching  cotton.  The 
pectio  acid,  fattv  matters,  &c.,  are  rendered 
soluble  by  the  alkaline  boilings,  and  the  colour- 
ing matters  still  remaining  are  oxidised  and 
destroyed  by  hypochlorites.  The  repetition 
of  these  operations  is  considered  necessary  by 
reason  of  the  large  percentage  of  impurities 
present;  but  it  is  verv  probable  that  good 
results  would  be  obtaineu  by  adoptine  the  more 
rational  plan  of  first  removing  the  whole  of  the 


612 


BLEACHING. 


pectio  and  fatty  matters  before  applying  the 
hypochlorites. 

A  prooesa  of  boiling  linen  goods  preparatory 
to  the  bleaching  has  bMn  pat^ted  by  Oroaa  and 
Parkes.  The  pieces  are  first  impregnated  with 
a  solution  of  soap,  silicate  of  soda,  caustic  soda, 
and  mineral  oiL  They  are  then  wound  on  a 
batching  roller  in  a  chamber  containing  steam, 
and  afterwards  steamed  for  some  hours.  This 
is  followed  by  boiling  with  a  solution  of  silicate 
of  soda  or  of  soda  mIl  The  goods  are  finally 
washed;  they  are  now  readv  for  the  first  <  dip.* 

Wool  seoiiring  and  bleaching.  The  bleaching 
of  wool  never  forms  a  separate  industry,  as  in  the 
case  of  cotton  and  linen,  and,  although  in  itself 
of  minor  importance,  it  is  necessarily  preceded 
by  the  operation  of  *  scouring,'  which  is  of 
fundamental  importance  both  to  the  woollen 
manufacturer  and  the  dyer. 

In  its  natural  oondition  the  wool  fibre  ii 
contammated  with  15-80  p.c  of  forei^  matter, 
consisting  partly  of  dirt,  &c.,  derived  itom 
without,  but  mainly  of  certain  fatty  matters 
designated  as  'yolk,'  secreted  by  the  animal 
from  which  it  is  derived.  This  secretion  is 
separable  into  two  parts — ^the  one,  *  wool-perspi- 
ration,' is  soluble  in  water,  and  consists  essenti- 
aUy  of  the  potassium  compounds  of  oleic  and 


I  stearic  acids  (potash  soaps),  dui, ;  the  other 
portion,  termed  '  wool-fat»'  is  insoluble  in  water, 
and  is  composed  of  cholesterol  and  iso-choleste- 
rol,  which  exists  partly  In  the  free  state,  bot 
chiefly  in  combination  with  oleic  add  and  other 
fatty  acids. 

Loose-wool  seouring.  The  object  of  scouring 
wool  is  to  remove  from  it  the  yolk,  ftc,  and  thus 
render  it  more  suitable  for  spinning,  dyeing,  or 
bleachinff.  Two  methods  of  effecting  it  may  be 
employeo.  The  one  generally  adoptra  is  to  treat 
the  wool  with  dilute  alkaline  solutions  capaUe 
of  forming  emulsions  with  the  yolk ;  the  other 
mode  is  to  submit  the  wool  to  the  successive 
action  of  fat  solvents,  carbon  disulphide,  &«., 
and  of  water. 

Seouring  with  alkaline  lolotlons.  When 
carried  out  in  the  most  complete  manner,  this 
method  comprises  the  following  operations : — 

1.  8Uep  several  hours  in  tepid  water. 

2.  Scour  15-30  mmntee  with  dilute  alkaline 

solutions  (soap,  sodium  carbonate,  &a) 
at  about  SO*"  G. 

3.  Wiuh  with  water. 

The  steeping  is  performed  in  a  series  of  larse 
iron  tanks^  in  whicn  the  wool  is  systematically 
washed  or  rather  steeped  in  water  heated  to 
46**  C,  until  it  is  deprived  of  soluble  matter.    As 


a  rule,  two  or  three  steeps  with  fresh  water  are 
found  sufficient;  but  it  is  customary  to  pass  the 
wash-water  through  several  loto  of  wool  until  it 
becomes  well  saturated  with  '  wool-perspiration.* 
It  is  jMtfticuIarly  advantageous  in  the  case  of 
wools  rich  in  yolk  {e.g,  Buenos  Ayres  wool,  &c.), 
since  it  prevente  too  rapid  soiling  of  the  scouring 
bath  and  consequent  staining  of  the  wool,  ana 
thus  it  tends  to  ensure  more  complete  scouring. 
By  evaporating  the  waste  steepmg  liquors  to 
dr3mess,  and  oalcining  the  residue,  a  good  quality 
of  potassium  carbonate,  conteining  very  IttUe 
sodium  salto  and  suitable  for  glass  manufac- 
turers, is  obtained. 

The  $couring  and  washing  of  the  wool  in 
order  to  remove  the  remaining  *  wool-fat '  is  best 
performed  by  the  aid  of  so-called  wool-scouiing 
machines,  one  of  which  (J.  &  W.  McNaught's) 
is  shown  in  Fig.  11. 

It  oonsisto  of  a  laige  rectangular  trough,  ▲, 
with  a  light  frame,  b,  suspended  over  it  by  onains 
and  carrying  a  series  of  transverse,  fixed,  vertical 
rakes  or  combs,  a 

The  wool,  either  in  ito  raw  condition  or  after 
steeping,  is  spread  evenly  on  the  moving  endless 
apron  or  feeder  d  ;  it  is  thus  continuously 
introduced  at  one  end  of  the  trough. 

By  suitable  mechanism  the  frame  is  lowered, 
and  tne  wool  is  at  once  pressed  beneath  the  sur- 
face of  the  scouring  liquor  by  the  perforated  tray 


or  sieve  n.  When  the  frame  is  sufficiently 
lowered,  it  moves  forward,  the  rakes  gently  oarty- 
mff  the  wool  towards  the  other  end  of  the  trough. 
When  the  forward  stroke  is  completed,  the  frame 
is  lifted  up,  the  rakes  rise  vertically  out  of  the 
liquid,  and  the  frame  returns  to  its  original 
position.  By  these  successive  movemente  the 
wool  is  slo^y  passed  through  the  scouring  liquor. 
At  the  delivery  end  it  is  carried  up  the  incUned 
plane  f  by  the  rakes  fixed  on  the  small  frame  o, 
which  is  hinged  to  the  larger  one.  Having  been 
pushed  over  the  ridge,  the  wool  slips  down 
between  the  squeezing  roUers  H,  H,  resay  to  be 
passed  through  a  second  similar  machine. 

The  worlong  of  the  machine  as  above  de- 
scribed, is  suiteble  for  Botany  and  other  fine 
olasses  of  wooL  When  washing  low  ClSape,  River 
Plate,  and  similar  wools,  which  contain  much 
dirt  and  sand,  an  additional  movement  is  g^ven 
to  the  rakes  while  in  the  liquor.  This  is  effected 
by  having  the  rakes  fixed  m  a  second  frame,  oo, 
which  receives  a  slight  backward-and-forward 
movement  by  means  of  the  rod  o  and  the  cam  K 
during  the  inward  movement  of  the  main  frame 
BB,  to  which  it  is  attached.  By  this  means  the 
wool  is  sliffhtly  opened  out  and  agitated,  and  the 
sand  and  dirt  fall  through  the  perforated  grating 
LL.  When  the  scouring  liquor  becomes  to& 
soiled  for  further  use,  the  steam  injectors  mm 
are  brought  into  action  in  order  to  stir  up  all 


BLEACHING. 


sediment,  and  the  dirty  liquor  is  run  off  by  the 
plus-hole  N. 

For  a  complete  arrangement  there  should  be 
at  least  three  such  machineB  placed  in  line,  so 
that  the  wool  passes  automatically  from  one 
to  the  other.  The  first  contains  more  or  less 
soiled  scouring  liquid  which  has  been  previously 
used  in  the  second  trough ;  the  second  contains 
fresh  scouring  liquid ;  and  the  third  a  continual 
flow  of  clean,  cold,  or  preferably  tepid  water. 

The  choice  of  scourinj^  agents  depends  upon 
the  character  and  quahty  of  the  wooL  For 
fine  lustrous  wools  and  such  as  are  poor  in 
yolk,  a  mild  scouring  agent  should  be  selected,  e,g, 
soap,  ammonia,  ammonium  carbonate,  'lant,' 
fta,  that  is  to  say,  agents  which  are  capable  of 
removing  the  yoUc  with  the  least  injury  to  the 
fibre.  The  best  soaps  to  use  are  those  which 
are  most  soluble  and  least  likely  to  contain  any 
trace  of  caustic  or  carbonated  potash  or  soda. 
Shoulcl  these  injurious  constituents  be  present, 
the  soap  solution  may  be  de-aUcalised  by  the 
addition  of  a  small  quantity  of  boracic  acid  cr 
ammonium  chloride,  thus  yielding  the  less  in- 
jurious alkali  borates  and  ammonia,  respectively. 

Potash  soaps,  being  very  apt  to  contain  excess 
of  alkali,  should  be  critically  examined.  An 
excellent  and  very  soluble  soap  may  be  readily 
made  from  oleic  acid  and  caustic  soda. 

Although  a  perfectly  neutral  soap  does  not 
always  effect  a  rapid  and  complete  removal  of 
yolk,  still  it  is  better  to  adopt  it,  since  one  can 
always  add  the  proper  quantity  of  other  agents, 
t.g,  sodium  carbonate,  ammonia,  ftc,  when 
necessary. 

For  low-class  wools  containing  a  large  po- 
portion  of  yolk,  and  when  cheapness  is  a  oesi- 
oeratum,  sufficiently  satisfactory  results  are 
obtained  by  the  proper  use  of  sodium  carbonate 
free  from  caustic  soda  or  other  injurious  im- 
purity. Suitable  sodium  carbonates  are  sold 
under  such  commercial  names  as  refined  soda 
ash,  Solvay  soda,  concentrated  crystal  soda 
(Brunner,  Mond,  ^  Go.),  crystal  carbonate 
(Gaskell^  Deacon,  &  Go.),  ftc. 

It  is  impossible  to  ^ve  precise  data  with 
respect  to  the  concentration  and  temperature  of 
the  scouring  solution  to  be  employed,  since 
these  vary  somewhat  accordins  to  the  character 
of  the  wool  operated  upon.  If  the  best  results 
are  to  be  obtained,  the  solutions  must  i^ways  be 
applied  as  dilute  and  at  as  low  a  temperature 
(not  above  60^  0. )  as  is  consistent  with  tbe  com  - 
plete  removal  of  the  yolk. 

The  waste  soourinff  liquors  are  collected  in 
large  tanks  and  neutnuised  with  sulphuric  acid  ; 
the  liberated  fatty  acids  are  sold  to  oil  refiners, 
who  by  distillation  obtain  purer  products, 
suitable  for  making  soap. 

Seouring  wtth  voUtile  ttqnids.  This  method 
is  still  only  in  an  experimental  stage.  Mechani- 
cal difficulties,  the  fear  of  fire  and  explosions,  the 
first  cost  of  the  scouring  agent,  Ac,  seem  to  have 
prevented  the  general  adoption  of  this  process. 
Its  advantages  are  that  the  wool-fat  is  more 
completely  removed  than  by  the  emulsion 
method,  and  the  wool  itself  is  not  injured.  A 
certain  degree  of  success  has  been  obtained  by 
the  method  proposed  by  T.  J.  MuUings,  and 
tried  on  a  large  scale.  It  consists  in  submitting 
the  wool  to  the  action  of  carbon  disulphide 
in  a  closed  centrifugal  machine  until  the  whole 


613 

of  the  wool-fat  is  dissolved,  then  expelling  the 
solvent  by  means  of  water,  and  not  as  heretofore 
by  heat  or  steam,  which  always  leaves  the  wool 
with  a  yellow  colour.  The  wool  must  afterwards 
be  washed  in  warm  water  to  remove  wool- 
perspiration  and  other  impurities.  The  wool 
cleansed  in  this  manner  is  said  to  be  stronger, 
capable  of  spinning  finer  yam  and  with  Tees 
waste  and  at  less  cost  than  if  scoured  by  the 
ordinary  method  with  soap. 

The  same  principle  is  adopted  in  the  process 
of  Singer  &  Judell.  of  Adelaide,  who  employ, 
however,  a  more  elaborate  and  more  pc^ect 
apparatus,  whereby  the  scouring  is  made  con- 
tmuous.  The  raw  wool  is  placed  on  a  feedinc 
apron  and  carried  along  between  two  broad 
endless  bands  of  wire  gauze,  first  through  a 
succession  of  fourteen  tanks  containing  carbon 
disulphide  and  then  throueh  five  containinff 
water,  all  suitably  enclosed.  The  wool,  still  held 
between  the  wire  gauie  bands,  then  passes 
between  hot  rollers  in  a  steam-heated  oryins 
chamber  and  emerges  in  a  scoured,  washed,  and 
dried  condition.  Arrangements  for  automati- 
cally collecting  the  dirt  which  settles  from  the 
carbon  disulphide,  for  separating  the  latter  from 
the  water,  distilling  and  returning  it  to  the 
scouring  tanks  with  the  least  possible  loss,  are 
aU  provided  for  by  ingenious  devices,  and  the 
general  arrangement  seems  eminently  typical  of 
the  method  of  scouring  wool  to  be  adopted  in  the 
future.  It  is  said  to  have  been  worked  with 
success  in  Australia. 

Woollen-yarn  seooring.  The  object  of  scour- 
ing woollen  yam  is  to  remove  the  oU  with  which 
wool  has  been  impregnated  by  the  spinner. 
Precisely  the  same  agents  are  used  as  for  loose 
wool,  but  the  machinery  employed  is  necessarily 
different. 

Those  yams  which  have  a  tendency  to  curl 
up  because  they  have  been  highly  twisted  are 
submitted  to  the  preliminary  operation  of 
'  stretching ' ;  it  also  prevents  them  trom  shrink- 
ing duriiu;  the  subsequent  scouring  process. 

The  hanks  of  yam  are  suspended  on  the 
arms  of  a  strong  iron  frame  and  tightly  stretched 
by  means  of  screws.  Thus  charged,  the  frame  is 
immersed  in  boiling  water  for  a  few  minutes. 
After  changing  the  position  of  the  hanks  on  the 
arms,  the  operation  is  repeated,  the  yam  is 
allowed  to  cool  in  the  stretched  condition,  and 
is  then  removed  ready  for  scouring. 

The  scouring  of  yam  is  effected  either  by 
hand  or  by  machine.  In  the  first  case  the 
hanks  of  yam  are  suspended  on  wooden  rods 
placed  across  a  rectangular  steam-heated  tank 
containing  the  scouring  liquor.  During  a  period 
of  15  to  20  minutes  the  rods  are  swayed  to  and 


Fio.  12. 

fro   by  hand,   one  by  one,  each  hank  being 
frequently  tom^  in  order  to  expose  every  por- 


a  of  tha  liquor.     The  yam  a  |  in   enioiiiia;  the  Booured  and  vashed  wooUea 


Above  and  below,  and  a  pair  of  Bqueeiing  collani,   pot  ii  ignited,  the  ohamber  door  ia  oloeed,  md 


Bud.  The  hanks  of  yam, 
linked  together  by  meant  of  string  loops,  are 
passed  oontinuoualy  thmugh  the  scouring  liquor, 
and  ate  then  wsahed  in  a  Bimikr  maonine 
(sec  Fig.  12). 

WooUw-elotli  wonrlng. ,  Woolleu  oloth  is 
also  Mtonrod  for  the  purpose  of  removing  the  oil 
with  which  ibe  yarn  is  impregnated  by  the 
■pinner.  The  operation  consists  in  passing  tha 
cloth  as  an  endless  band,  either  in  the  strand  form 
or  in  tha  open  width,  through  the  soourino  liquor 
and  then  through  a  pair  of  squeezing  loller*. 

For  thick  woollen  ololhs,  flannels,  Ac,  sooot- 
ing  in  the  strand  is  preferred,  since  a  certain 
amount  of  felting  takes  place  and  the  cloth 
acquiiea  a  better  handle.  For  wanted  goods 
and  Buoh  M  are  liable  to  crease,  soouring  in  the 
open  width  is  preferable. 

Fig.  13  shows  a  section  of  £.  Kampe's 
machuie  for  this  purpose.     It  consists  of  two 


Fio.  13. 


^_  o  containing  the  (counng  liquor. 

The  roller  i>  servee  to  draw  the  cloth  Rom  ijke 
squeezing  rollers,  and  causes  it  U>  fall  in  regular 
ftjds  upon  the  inclined  plane  u.  This  is 
ooTcred  with  corrugated  cine,  the  groovea  of 
which  run  longitndinally,  in  order  to  raduce  the 
friction  of  the  cloth,  and  to  prevent  the  latter 
from  moving  to  either  side.  The  upper  part  of 
the  inclined  plane  is  hinged  at  F,  so  that  the 
inolination  of  this  port  can  be  regulated  to  suit 
different  qualities  of  cloth,  and  te  ensure  that  it 
always  slips  down  in  regular  folds  without  any 
tendency  to  fall  over  or  become  blocked.  The 
perforated  water- pipee  a,  o  are  for  the  purpose  of 
washing  the  cloth  after  scouring. 

Blt&chlng  of  WOOL  After  scouring,  the  wool 
still  poBseasee  a  faint  yeUow  tint,  to  remove  which 
is  the  object  of  the  bleaching  proper.  The  agent 
almost  univoTBaUy  employed  u  sulphur  dioxide, 
either  in  the  form  of  gas  (gas-bleaching)  or  in 
solution  (liquid- bleaching).  With  hydrogen  per- 
oxide a  more  permanent  white  is  obtained,  but 
it  is  still  too  expensive'  to  admit  of  extended 
appUcation,  but  it  serves  as  an  ezoellcnt  bleach- 
ing agent  for  oertain  fine  materials. 

Ou-blMeUiif ,  ttofliis,  or  nilpliniiiii.  oonsists 


the  material  is  then  left  exposed  ti 
of  the  gaa  for  eiz  or  eight  hours,  or  even  over- 
nighL  Thin  cloth  ia  geacrotly  passed  in  a  con- 
tinuous manner  through  a  sirnilar  <diamber  pn>- 
vided  with  rollers  above  and  below.  The  doth 
in  tha  open  width  enters  through  a  narrow  slit 
at  one  end  of  the  chambai ;  it  passes  in  a  zig- 
zag course  under  and  over  tha  loUen  to  the 
further  end,  then  returns  aad  pMses  out  by  the 
same  slit.  The  sulphur  dioxide  ia  prepared  in 
the  stove  itself,  or  it  is  produced  in  a  separate 
furnace  and  led  beneath  the  perforated  floor  of 
the  chamber.  Aooording  to  the  appearance  of 
the  fabric,  it  is  passed  through  tike  bleaohinn 
ohambdr  once  or  several  times.  Fig.  14  giva  a 
sectional  view  of  the  sulphur  store  for  the 
continuous  bleachine  of  cloth. 

In  UqnU-bleaeUiig  the  woollen  material 
is  immeiMd  and  moved  about  for  several  hoon 
in  a  solution  of  sulphurous  acid,  or  in  one  oon^ 
taining  sodium  bisulphite,  and  ocidi&ad  wiUi 
sulphuric  acid.  One  may  also  steep  the  wool, 
first  in  a  solution  of  sodium  bisulphite  and  tboo 
in  dilute  sulphuric  acid,  and  repeat  the  opera- 
tions as  often  as  may  be  neoeasary.  The  liquid- 
bleaching  pnwees  bu  not  met  with  that  general 
acoeptonoe  to  which  it  seems  entitled. 

After  bleaching,  the  materials  aie  well  waahed 
and  tinted  blue  or  bluish-violet,  e.g.  with  rafiued 
indigo,  indigo-eitraot,  oniliue-blae,  msUiy] 
violet,  &0.,  in  order  to  oonnteraot  the  yellowiut 
tint  which  is  so  liable  to  return. 

The  bleaching  action  of  sul^^nrom  ooid  ia 
most  iffobably  due  to  its  reducing  properties. 
According  to  this  view,  the  sulphuroua  acid  take« 
np  oxygen  from  the  water  present,  while  Hm 
liberated  hydrogen  oombinee  with  the  oolonring 
matter  of  the  wool  to  form  a  colourless  lenoo- 
compound.  Another  explanation,  however,  is 
that  a  colourless  sulphurous  add  compound  U 
formed.  Frequent  washing  of  t^a  wool  with 
alkaline  solutions  reetoras  the  yellow  colour. 
It  seems  evident,  however,  that  the  yellowing 
influence  of  alkalis  is  largely  due  to  their  further 
action  upon  the  wool  substance  itstdf  since  they 
cause  the  wool  eventually  to  beoome  yellower 
than  it  was  before  bleaching. 

Bleaching  with  hydrogen  peroxide  is  effected 
by  steeping  the  wool  for  sevenl  hours  in  more  or 
less  dilute  solutions  of  this  liquid,  made  slightly 
alkaline  by  tha  addition  of  ammonia.  Tha 
simultaneous  action  of  light  aocelKatea  and 
improves  the  bleaching.  The  white  ia  vary  good 
and  permanent,  probably  bacausa.  in  this  case, 
the  colouring  matter  is  destroyed  by  oxidation. 
Excessive  bleaching  by  this  method  gives  the 
wool  a  harsh  feel.  Lunge  reoommcnds  a  sli^t 
treatment  with  hydrogen  peroxide  of  sulphur- 
Ueached  wool  in  order  to  oxidise  and  Uius 
render  innocuous  traces  of  sulphurous  aoid  not 
lamoved  by  washing.  A  very  dilute  solution  of 
sodium  hypochlorite  and  exposure  to  air  will 
effect  the  same  purpose. 

Bleaching  of  wool  with  hydrosclphite  of  soda 
has  been  suggested  by  F.  V.  Kallah.  It  is 
prepared  by  adding  zino  powder  to  a  atdntMn 


of  bitulphite  of  «ada.    The  lino  ii  preoipilatod 
by  adding  milS  of  limo. 

811k  Monrliig  uid  blauUng.  The  n-a  silk 
fibre  conaUts  easantialh'  of  two  aubatonoa, 
fibratiu  and  ttricine.  The  former  oonatilutea 
the  central  portion  of  the  fibre,  and  m«j  be  ro- 
guded  aa  the  fibre  proper,  while  the  latter  retide* 
prinoipally  in  the  external  part  and  ia  readily 
removed  by  water  and  espeoially  alkaline 
solutions. 

Raw  ailk  is  harsh,  atiff,  loatreless,  and  more 
or  lees  nnsuitable  for  dyeing,  but  vhen  th«  ex- 
ternal serioiue  or  sjlk-glne  is  nmovedit  become* 
soft  and  Instroos,  and  aoqniiM  an  increased 
affinity  for  colouring  matters. 

The  object  then  of  soonriog  is  to  remove  the 
mik-gloe  from  the  raw  silk.  It  is  effected  by  the 
two  operations,  '  alripping  '  and  '  boQing-off.' 

Btripping  -or  ungamming.  In  order  to  r 
move  calcareous  or  other  mineral  matter  soluble 
in  dQnte  acids,  it  ia  well  first  to  rinse  the  silk  in 
a  tepid  bath  of  dilute  hydiochloria  acid,  and 
then  wash.  The  haoka  oC  silk  are  then  hung  on 
smooth  wooden  roda  and  worked,  aa  in  wooUen- 
yam  scooring,  in  a  aoap-bath  heated  to  about 
80°-9&°  C  for  aboot  20  minutes.  A  second  and 
eren  a  third  bath  may  be  used  with  advan- 
tage. Long  working  in  one  bath  is  not  good, 
espeoUUy  for  ailk  intended  to  be  white,  aiooe  the 
silk  (Sbrolne)  is  apt  to  attract  lome  of  the  ooloor- 
iog  matter  at  first  removed  aloiu  wiUi  the  ailk- 
slne,  and  it  is  afterwaniB  very  dififoinlt  to  remove. 
With  yellow  ailk  this  point  must  be  iHU«fiiUy 
attended  to. 

During  the  stripping  operation  the  sericine 
at  fint  smlls  up  and  makes  the  ailk  somewhat 

fibre  soft  and  Inatrt 
stcoogly  impregoa 
foU^  preserved  and 


silk  is  effected  by  exposing  the  •oonied  silk,  w 
still  in  the  wet  state,  to  the  action  of  solphur 
dioxide  gas.  The  operation  is  precisely  similar 
to  the  staving  of  wool. 

In  oertain  oases,  t.g.  with  so-called  '  souple  ' 
silk,  the  atoving  is  preceded  by  a  preliminary 
bleaching  in  aqva  rtgia,  diluted  to  ap.gr.  1-03 
and  heated  to  M'-SB"  C.  The  silk  is  rinsed  in 
this  solution  for  8~lfi  minutes  until  it  aoqnire« 
a  greeniah-grey  colour,  and  then  at  once  washed 
well  in  cold  water.  A  dilute  solution  of  the 
so-called  'chamber-crystals'  of  the  sulphuric 
acid  manufacture  may  replace  the  aqua  rtgia. 

The  bleaohing  of  silk  with  hydrogen  peroxide 
Is  gradually  bemg  more  and  more  adopted, 
especially  for  Tuaaur  ailk  and  other  wild  silka. 
Indeed,  for  these  silka  no  other  method  of 
bleaching  is  ao  sstisfaotoiy.  The  silk  ia  steeped 
and  worked  in  a  dilute  solution  of  hydrogen  per- 
oxide, rendered  slightly  alkaline  with  ammonia 
or  with  silics(«  of  soda  or  borax,  until  it  is 
BufEciently  bleached.  A  more  rapid  and 
effective  method  ia  to  ateep  the  silk  in  a  some- 
what stionger  solution,  then  wring  out  the 
excess  of  Uqoid,  and  steam.  The  operations  may 
be  repeated  until  the  silk  is  sufficiently  bleacheii. 

TmtlllCOl  silk.  Bleached  silk  is  finiUy  tinted 
or  dyed  ia  delioato  ahades  of  blue,  purplish -blue, 
cream  colour,  Ac  For  pure  white  it  is  usual  to 
dye  the  silk  in  a  Tery  dilute  solution  of  a  suitable 
coal-tar  colour.  After  tinting,  the  ailk  ia  allghtly 
tinsed  in  water  and  dried  in  a  moderately  warm 
and  darkoied  stove.  J.  HiL 

BLEACHIMQ  POWDER  v.  Cuu>e.mt. 
BLENAL,    Carbonie  acid  eater  of  sant«lol 


-  Whenai 


Vhen  apidying  th< 

o  retard  their  atl 
thus  ensures  the  pi 
oolours. 

After  stripping 
containing  a  smal 
sodium  carbonate. 
Boiling-off.  Tl 
ia  to  completo 
the  removal  of 
the  ailk-glue  and 
thus  give  the  silk 
all  the  lustre  and 
brilliancy  of 
which  it  is  cap- 
aUe.  The  hanks 
of  silk  are  tied 
up  in  coarse  bags 
of  cotton  or 
hemp,  generally  -, 
called  '  pockets,'  >' 
and  these  are 
boiled  for  one  to 
three  boura  in 
open       copper 

boilers.  The  silk  is  then  well  rinsed  in  a  weak 
t0pid  solution  of  carbonate  of  soda,  and  finally 
bi  cold  water. 

During  the  operations  abore  described, 
Japaneae  and  Chinese  silks  lose  lS-22  p.c  in 
weight,  European  silks  lose  2S-30  p.c. 


Fio.  14. 

BLEHDE,   from    Skndtn,   Get.,   to   dacxle. 

Native  line  sulphide.  It  usually  oootaios  iron 
sulphide  which  gives  it  a  black  colour,  whence 
the  name  Black  Jack  applied  to  it.  An  im- 
portant ore  of  lino.  The  sulphur  it  contains  is 
oooasionally  utilised  in  the  manufacture  of  sul- 


bid 


BLENDB. 


phuno  acid.    (For  doBctiptionB  of  burners  for 
this  purpose,  v.  J.  Soo.  Chem.  Ind.  3,  631 ;   4, 

54.)      F.  ZlNC-BLBKDB. 

BLEU  DIRECT  or  DIPHENYLAMINE  BLUE 

V,  Triphekylbubthakb  coloubiko  mattbrg. 

BLEU  FLUORESCENT  C„H,Br.N,0.(NH,). 
A  oolounng  matter  obtained  by  Weselsky  and 
Bencdikt  in  1880  by  treating  diazoresorufin 
dissolved  in  potassium  carbonate  with  bromine 
and  precipitating  by  an  acid.  Soluble  in  boiling 
water  with  a  red-violet  colour,  giving  a  fluor- 
escent green  solution.  Dyes  silk  and  wool  blue 
with  brownish  fluorescence  (Weselsky  and 
Benedikt,  Monatsh.  6,  606;  Ber.  1886,  18; 
Ref.  76). 

BLEU  DE  6ARANCE.  Artificial  ultra- 
marine {v.  Ultbamabinb  ;   Piombnts). 

BLEU  LUHI&RE  v.  Triphbnylmbthanb 
coLOUBnra  mattebs. 

BLEU  DE  LYON,  BLEU  DE  NUIT,  BLEU 
DE  PARIS  V.  Tbifhsnylhethanb  coloubino 

MATTEBS. 

BLEU     MARIN     v.     Tbiphbhylmbthakb 

GOLOUBINO  ICATTEBS. 

BLEU  DE  SAXE  v.  Cobalt. 

BLEU  SOLUBLE  v,  Tbifhenylmbthakb 
coloubino  mattbbs. 

BUND-COAL.  A  Scotch  term  for  anthra- 
cite. 

BUSTER  STEEL  v.  Ibok. 

BLOCK  FUEL  v.  Fuel  ;  also  Pitch. 

BLOCK  TIN  V,  Tin. 

BLOEDITE.  A  hydrated  double  sulphate 
of  magnesium  and  sodium,  Na2Mg(S04),'4H|0, 
forming  water-clear  monoclinic  crystals,  often  of 
laige  size  and  beautifully  developed.  They  are 
found  in  the  salt  mines  of  Stassfurt  and  in 
Austria,  and  in  the  Punjab  Salt  Range,  India. 
Crystals  16|  cm.  in  length  have  been  found  in 
the  black  mud  beneath  a  crust  of  sodium  sul- 

ghate  on  Soda  Lake,   San  Luis  Obispo  Co., 
alifomia.     Simonyite   and   astrakanite   (from 
salt  lakes  ne«kr  Astrakan)  are  sjmonyms. 

L  J  S 
BLOMSTRANDINE.  A  rare-earth  mineral 
consisting  of  a  titano-columbate  of  yttrium - 
metals,  thorium,  uranium,  &c.,  occurring  as 
orthorhombio  crystals  in  pegmatite  veins  at 
several  localities  in  southern  Norway.  The 
large  crystals  of  tabular  habit  are  found  in  the 
felspar  quarries,  and  those  from  the  island  of 
Hittero  are  well  known  in  collections.  They 
are  brown  on  the  surface,  but  on  a  fresh  con- 
choidal  fracture  the  colour  is  black  with  a  bright 
pitchy  lustre.  The  mineral  is  optically  iso- 
tropic, owing  to  alteration  by  hydration. 
Sp.gr.  4*82-4*93.  These  crystals  were  pro- 
visionally referred  by  W.  C.  Brogger  in  1879  to 
aeschynite  {g-v.),  an  allied  species  differing 
maimy  in  containing  cerium-metaJs  in  place 
of  yttrium-metals.  More  recently,  Brogger 
(Die  Mineralien  der  siidnorweffischen  Granit- 
Pegmatitgange,  Videnskabs-Sel^kabets  Skrifter, 
Kristiania,  1906)  has  given  a  detailed  descrip- 
tion of  this  material,  and  he  gives  several  other 
Norwegian  localities  for  the  mineral,  namely, 
near  i!^ndal  and  in  Stetersdal.  He  interprets 
the  complex  composition  as  an  isomorpnous 
mixture  in  varying  proportions  of  a  meta- 
columbate  with  a  metatitanate ;  and  for 
another  member  of  the  same  series  from  the 
tin  gravels  of  Swaziland,  Transvaal,  shown  by 


G.  T.  Prior's  analysis  (1899)  to  Contain  more 
columbium  with  less  titanium,  he  proposed  the 
name  priorite.  These  isomorphous  TninAri>.]a 
I  blomstrandine  and  priorite,  are  respectively 
!  dimorphous  with  polycrase  and  euxenite ;  the 
four  minerals  euxenite-polycrase  and  priorite- 
blomstrandine  thus  forming  an  isodimorphoua 
series. 

The  name  blomstrandine  is  not  to  be  con- 
fused with  the  earlier  name  hlomMrandite 
(of  G.  landstrom,  1874),  which  jiras  applied  to 
an  uncrystaUised  hydrated  titano-columbate 
and  tantalate  of  uranium  with,  some  calcium  and 
iron,  from  a  felspar  quarry  at  Nohl,  in  Sweden 
(V.  Betafiti),  L.  J.  8. 

BLOOD  is  a  richly  albuminous  fluid  which 
holds  in  suspension  large  numbers  of  corpuscles. 
The  fluid  medium  in  which  the  corpuscles  float 
18  called  the  plasma,  or  Uquor  sanguinis.  In 
round  figures,  tne  plasma  contains  about  10  p.o. 
of  solids,  of  which  proteins  comprise  8,  eztrao- 
tives  1,  and  inorganic  salts  (the  princifAl  one 
being  sodium  chloride)  the  remaining  1.  The 
proteins  are  all  ooa^lable  by  heat,  and  are 
named  serum  albuxmn,  serum  globulin,  and 
fibrinogen.  The  last-named  is  the  least  abun- 
dant (0*4  p.c.),  but  confers  upon  the  blood  its 
characteristic  power  to  dot  or  coagulate  when 
it  is  shed.  When  shed,  the  blood  rapidly 
becomes  viscous,  and  then  sets  into  a  jelly ;  the 
jelly  contracts  and  squeezes  out  of  the  clot  a 
straw-coloured  fluid  called  serum,  in  which  the 
shrunken  clot  then  floats.  The  formation  of 
threads  of  a  solid  protein  called  fibrin  from 
fibrinogen  is  the  essential  act  in  coagulation ; 
this  with  the  corpuscles  it  entangles  constitutea 
the  clot,  and  serum  is  plasma  minus  the  fibrin 
which.it  yields.  The  following  scheme  shows 
the  relationships  of  the  ooni^ituenta  of  the 
blood  at  a  glance  : —  . 

(1  rserum 

plasmajgjj^ . 
corpuscles  r^^^ 
In  round  figures,  the  blood  contains  60-65  p.c 
of  plasma,  and  35-40  p.o.  of  corpusdee.  llLe 
corpuscles  are  of  three  kinds,  the  i^  corpuscles 
or  erythrocytes,  the  white  or  colourless  oor- 
pnscles  or  leucocytes,  and  some  very  small 
particles  also  colourless,  which  are  called  the 
blood-platelets. 

The  subject  of  blood  dotting  has  been  the 
battlefield  of  numerous  opposing  theories,  but 
the  view  now  generally  held  is  that  the  conversion 
of  fibrinogen  into  fibrin  is  due  to  the  action  of 
an  enzyme  called  thrombin  or  fibrin-ferment. 
This  agent  takes  ori^  from  the  platdets  and 
white  corpuscles ;  it  is  first  shed  out  horn  them 
in  an  inactive  form  called  thrombogen ;  throm- 
bogen  is  converted  into  the  active  enzyme 
thrombin  by  the  combined  action  of  the  calcium 
salts  of  the  plasma  and  of  an  activating  agent 
termed  thrombokinase,  which  originates  nom 
the  cells  of  the  blood  itself  and  of  the  other 
tissues  of  the  body. 

The  transformation  of  fibrinogen  into  fibrin 
has  been  regarded  as  a  chemical  change.  But 
the  recent  work  of  Hekma  fBiochem.  Zeitsch. 
1916,  Ixxiii.  and  Ixxiv.)  and  of  Howdl  (Amer.  J. 
Physiol.  1916,  40)  shows  that  the  change  is 
probably  a  nhysical  one.  Fibrinogen  is  the  sol^ 
and  fibrin  the  gdphase  of  the  protein.  Fibrin 
is  first  deposit^  as  ultramicrosoopio  particles 


BLOOD. 


617 


(mioroxu),  then  fine  needle-like  crystals  appear ; 
tiiese  by  agglutinating  together  mtimateiy  lead 
to  the  xormation  of  typical  fibrin  threads. 

The  white  or  colouness  corpuscles  are  typical 
nucleated  animal  cells  which  have  been  differ* 
entiated  into  varieties  by  their  staining  re- 
actions, the  number  of  their  nuclei,  and  their 
seat  of  origin  (lymphoid  tissue,  and  red  bone 
marrow][.  Their  most  important  property  is 
their  power  of  amosboid  movement,  by  which 
they  ingest  and  subsequently  digest  foreign 
particles.  They  act  in  this  way  as  scaven^rs 
(phagocytes),  and  thus  confer  protection  against 
pathogenic  organisms  (bacteria,  &c.)* 

The  red  corpuscles  are  much  more  numerous 
than  the  whiter  averaeing  in  man  5,000,000  per 
cubic  millimetre,  or  400-^K)0  red  to  each  white 
corpuscle.  It  is  these  which  give  the  red  colour 
to  the  blood.  They  vary  in  size  and  structure 
in  different  groups  of  the  vertebrates.  In 
mammals  they  are  biconcave  (except  in  the 
camel  tribe,  where  they  are  biconvex)  non- 
nucleated  discs,  in  man  y^^  inch  in  diameter ; 
during  foetal  life  nucleated  red  corpuscles  are, 
however,  found.  In  birds,  reptiles,  amphibia, 
and  fiflhes,  they  are  biconvex  oval  discs  with  a 
nudeos;  they  are  largest  among  the  amphi- 
bians. Their  most  important  and  abunoiant 
constituent  is  the  pigment  hsmoglobin.  In 
invertebrates  this  respiratory  pigment  is  usually 
absent,  and  when  present  is,  with  few  exceptions, 
in  solution  in  the  plasma  and  not  in  special 
corpuscles.  In  other  invertebrates  its  place  is 
taken  by  other  respiratory  pigments,  for 
instance,  by  the  ereen  pigment  wmch  contains 
iron  and  is  called  chlorocruorin  (in  certain  worms), 
or  by  the  blue  pigment  which  contains  copper 
and  is  termed  htemooyanin  (in  certain  crus- 
taceans and  molluscs).  The  vast  majority  of 
invertebrates  have  colourless  blood  containing 
only  colourless  corpuscles.  Hemoglobin  con- 
tains 0*4  p.0.  of  iron ;  it  and  certain  of  its 
dwivatives  give  characteristic  absorption  spectra 
which  form  one  of  the  best  tests  for  blood.  It 
is  termed  a  conjugated  protein^  consisting  of  a 
protein  (globin)  in  combination  with  the  iron 
containing  material  termed  hssmatin 

(0„H,oN4FeO,) 
H»moglobin  is  onrstallisable,  but  hsmatin 
has  not  yet  been  obtained  in  crystalline  form. 
By  boilmg  dried  blood  with  a  little  sodium 
chloride  and  glacial  acetic  acid,  the  character- 
istic brown  crystals  of  hsematin  hydrochloride 
or  hemin  are  readily  obtained,  and  this  is  the 
best  chemical  test  for  blood ;  it  can  be  performed 
quite  readily  on  a  microscope  slide.  By  treat- 
ment with  acid,  an  iron-free  derivative  of  h»- 
matin  is  obtained  called  hnmatoporphyrin,  and 
in  the  body  certain  iron-free  derivatives  some- 
what similar  to  haamatoporphyrin  axe  formed ; 
these  constitute  the  pigments  of  the  bile.  By 
the  reduction  of  hematopozphyrin,  hiemo- 
pyrrol  (a  mixture  of  pyrrol  derivatives)  is 
obtained,  and  the  same  substances  are  ob- 
tained also  from  phvlloporphyrin,  a  deriva- 
tive of  chlorophyll ;  tnis  is  an  interesting  fact, 
as  it  indicates  a  near  relationship  between  the 
principal  pigments  of  the  animal  and  vegetable 
worlds. 

During  life  the  blood  is  in  constant  move- 
ment (circulation),  and  it  is  owing  to  this  cir- 
cumstance that  it  supplies  the  tissues  with  both 


nutriment  and  oxygen.  The  products  of  pro- . 
tein  and  carbohyorate  digestion  pass  directly 
from  the  alimentary  canal  into  the  blood-vessels  ; 
the  fat  reaches  the  blood  indirectly  by  the 
lymph-stream.  The  blood,  however,  does  not, 
except  in  the  spleen,  actually  bathe  the  tissue 
elements;  the  middle-man  between  blood  and 
tissues  is  a  fluid  called  lymph,  which  exudes  from 
the  blood  through  the  thin  walls  of  the  capillary 
blood-vessels.  The  lymph  thus  supplies  the 
tissues  with  material  for  their  repair  or  for 
storage ;  it  also  removes  from  the  tissues  the 
waste  products  of  their  activity ;  it  is  collected 
by  lymphatic  vessels,  which  converge  to  the 
main  lymphatic  channel  called  the  thoracic  duct. 
This  opens  into  the  large  veins  near  to  their 
entrance  into  the  heart,  and  thus  the  lymph  is 
returned  to  the  blood,  and  the  waste  products 
are  then  conveyed  to  the  various  organs  (lungs, 
kidneys,  skin)  by  which  they  are  discharged 
from  the  body. 

The  function  of  blood  as  an  oxygen  carrier 
is  dependent  on  tiie  presence  of  hemoglobin. 
Oxysen  passes  by  diffusion  into  the  blood  of 
the  lunss,  and  is  then  seized  by  the  pigment, 
with  which  it  forms  a  loose  comx)ound  called 
oxyluemoglobin  ;  this  bright  -  red  arterial  or 
oxygenatM  blood  passes  to  the  heart,  and  is 
thence  propelled  by  the  arteries  all  over  the 
body ;  m  the  tissues,  where  the  oxygen  tension 
is  very  low,  oxyhsemoglobin  is  dissociated,  and 
the  oxygen  passes  into  the  plasma,  and  again 
reaches  the  actual  tissue  elements  vid  the  lymph. 
The  reduction  of  oxyhemoglobin  chanses  the 
colour  of  the  blood  to  the  darker  tint  wnich  it 
has  in  the  veins,  by  which  vessels  it  is  carried 
back  to  the  heart  and  sent  to  the  Ixram  for  a 
fresh  supply  of  oxygen.  The  venous  olood  is 
also  rich  in  carbonic  acid,  which  finds  an  exit 
from  the  blood  in  the  lungs  into  the  expired 
air.  It  should  be  noted  wat  hemo^obm  is 
not  the  exclusive  carrier  of  carbon  dioxide ;  the 
other  proteins  act  similarly,  but  the  ffas  is 
carried  mainly  as  carbonates  in  the  blood- 
plasma. 

The  amount  of  respiratorr  oxygen  carried  by 
the   blood   pigment   is   1*34   c.c.   oxygen   per 

fram  of  hemoglobin.  This  can  be  replaioed 
y  equivalent  amounts  of  such  gases  as  carbon 
monoxide  or  nitric  oxide.  These  compoufids 
are  more  stable  than  oxyhemoglobin,  and  the 
gas  is  not  removable  by  the  tissues ;  hence  in 
coal-gas  poisoning  the  colour  of  the  blood  is 
eqaafiy  bright  in  arteries  and  veins,  and  the 
cause  of  death  is  oxyoen  starvation. 

The  foresoing  ouUine  of  the  composition  and 
uses  of  the  olood  from  the  phvsiological  point 
of  view  can  be  amplified  by  the  study  of  any 
standard  textbook  of  physiology  or  physiological 
chemistry. 

Passing  now  to  the  technical  and  commercial 
aspect  of  the  case,  the  uses  of  the  blood  come 
mainly  under  four  headings:  (1)  as  food  ;  (2)  as 
manure ;  (3)  as  a  clarifying  agent ;  and  (4)  as  a 
drug. 

(1)  As  food.  Blood  as  such  is  only  used  as 
food  by  savages,  and  attempts  have  been  made 
to  utihse  dried  defibrinated  blood  as  a  com- 
mercial food  product  without  any  great  success. 
It,  however,  forms  an  important  constituent  of 
ceortain  articles  of  diet,  of  which  Black  pudding 
and  the  Grerman  Blutwurst  (Blood  sausage)  are 


618 


BLOOD. 


the  beet  known.  In  the  preparation  of  these 
pig's  blood  is  most  commonly  employed,  and 
tfaSy  are  of  high  nutritive  valne.  (For  the 
composition  of  varions  kinds  of  Blutwnrst^  see 
Konig,  Ghemie  d.  menBchl,  Nahranm  nnd 
Genussmittel,  Berlin,  1904,  625 ;  Pott.  Handb. 
d.  Tier-Emahrung,  iiL  513,  1909 ;  £.  Schmidt^ 
Lehrb.  d.  pharm.  Chem.  ii  2,  1833,  1901.) 

(2)  As  manure.  Dried  blood,  the  so-called 
Blood-meal  (Blutmehl),  is  extensively  used  as 
manure,  and  may  be  placed  directly  on  the  land, 
or,  more  frequently,  is  mixed  with  superphos- 
phates. It  is  a  brown  powder  with  a  glue-like 
smell,  and  must  be  kept  in  dry  places  to  avoid 
putrefaction.  It  is  valuable  on  account  of  its 
high  percentage  of  nitrogen  (11*8)  and  of 
phosphorus  (1*2  p.c.).  Numerous  patent  ma- 
nures contain  a  certain  proportion  of  blood. 
(For  details,  ha  Elonig,  l,c  496 ;  Merck's  Waren- 
Lexicon,  5th  ed.  art.  *  Blut.') 

(3)  As  a  clarifying  agent.  Blood  is  employed 
in  the  same  way  as  milk,  gelatin,  and  albumin 
are,  as  a  clarifying  agent  for  wines,  syrups,  and 
similar  liquids,  in  the  proportion  of  150-200  cc. 
of  blood  per  litre.  The  clearing  action  is  due  to 
the  proteins  present,  but  used  m  this  way  there 
is  considerable  danger  of  infection,  as  also  is  the 
case  for  milk.  Dried  blood  or  the  dried  blood- 
albumin  is  therefore  preferable.  Blood-albumin 
is  prepared  from  the  serum  drained  off  from  the 
clot ;  the  product  is  really  dried  serum,  as  the 
proteins  are  mixed  with  the  other  constituents 
of  that  fluid,  and  the  word  *  albumin '  is  used  as 
svnony  mous  with '  protein,'  and  not  in  the  correct 
chemical  sense.  It  has  the  advantage  of  being 
considerably  cheaper  than  e^K-albumin,  for  the 
total  blood  of  an  ox  will  y^d  750-^800  grams 
of  the  dried  product,  a  good-sised  calf  will  yield 
340-400  srams,  and  a  sheep  about  200  grams 
(«ee  Merck,  Lc.  art.  '  Blutalbumin '). 

(4)  The  therapeutic  uses  of  blood  and  serum. 
The  high  nutritive  value  of  blood  makes  it  a 
valuable  drug  in  the  treatment  of  an»mia,  and 
certain  patent  medicines  sold  under  the  name 
of  hsmatogen  consist  very  largely  of  blood 
mixed  with  suitable  flavouring  and  preservative 
agents.  A  still  larger  practical  use  of  blood 
products  (serum  therapy)  has  been  the  outcome 
of  work  on  immunity,  in  which  the  names  of 
Richet,  Ehrlioh,  BeliriQg,  and  Boux  may  be 
mentioned  as  those  of  pioneers.  Those  inte- 
rested in  problems  of  immunity  should  consult 
current  handbooks  of  pathologv.  The  foUowinc 
does  not  pretend  to  do  more  than  give  a  sketch 
of  the  mala  facts,  and  the  example  selected  of 
the  usefulness  of  the  method  is  that  in  which 
serum  therapy  has  been  the  most  successful, 
namelv,  the  treatment  of  diphtheria.  The 
animal  body  is  protected  against  its  foes  by  a 
variety  of  mechanisms,  and  against  our  micro- 
scopic (bacterial)  enemies  the  most  potent  of 
these  is  the  action  of  colourless  blood  corpuscles 
(phagocytosis).  This,  however,  ia  assisted  in 
certain  cases  by  the  presence  in  the  fluid  peurt 
of  the  blood  of  chemical  substances  which  have 
received  a  variety  of  names;  for  instance^  *  bacte- 
riolysins '  are  substances  which  actually  kill 
bacteria  ;  '  agglutinins  '  are  substances  which 
clump  the  bacteria  together  and  render  them 
immobile ;  '  opsonins '  are  substances  which 
render  bacteria  an  easy  prey  to  leucocytes,  either 
by  adding  sometMng  to  them  to  make  them 


tasty  or  removing  somathing  from  them  which 
makes  them  distasteful ;  and  *  antitoxins '  an 
substances  which  neutralise  the  poisons  or  toxins 
which  are- produced  by  the  bacteria.  There  is 
very  little  accurate  chemical  knowledge  of  the 
composition  of  these  various  materiujs;  they 
are,  however,  as  a  rule,  destroyed  by  a  high 
temperature,  and  are  probably  protein-like  in 
nature.  The  amount  of  these  substances  in  the 
blood  may  be  increased  by  certain  stimuli,  much 
in  the  same  way  as  the  epidermis  becomes  thick- 
ened as  the  result  of  manual  labour.  The 
administration,  for  instance,  of  small  doses  oi 
the  toxin  will  produce  an  excessive  production 
of  the  antitoxin  which  specifically  neutralises 
the  poison.  Substances  which  m  this  way 
stimulate  the  production  of  these  natural  anti- 
dotes are  spoken  of  in  general  terms  as  antigens. 

If  the  bacilli  ^ich  produce  diphtheria  are 
grown  in  a  suitable  medium,  they  produoe 
the  diphtheria  toxin  much  in  the  same  way  as 
yeast  will  produce  alcohol  when  grown  in  a 
solution  of  sugar.  If  a  certain  smaU  dose  of 
this  poison  is  injected  into  an  animal,  it  will 
produoe  death,  and  that  is  called  the  lethal 
dose.  But  if  the  animal  receives  a  smaller  doe^, 
it  will  recover ;  a  few  days  later  it  will  stand  a 
larger  dose  and  recover  more  quickly;  this  is 
continued  until  after  many  successively  increas- 
ing doses,  it  will  finally  withstand  without  ill 
CTOCts  an  amount  equal  to  many  lethal  doses. 
The  animal  is  now  immune  against  diphtheria, 
for  the  administration  of  the  toxin  (or  antigen) 
has  called  forth  an  excessive  production  of 
antitoxin,  and  the  blood  remains  rich  in  anti- 
toxin for  a  considerable  but  variable  time ;  the 
serum  obtained  from  the  blood  of  the  immunised 
animal  is  then  employed  for  injecting  into  other 
animals  or  human  beings  sulraring  from  diph- 
theria, and  rapidly  cures  the  disease.  The  horse 
is  the  animal  selected  for  the  preparatitm  of 
antitoxin,  and  the  success  of  the  new  treatment 
in  reducing  the  death-rate  from  what  used  to 
be  considered  a  terrible  disease  is  one  of  the 
wonders  of  modem  medicine. 

(5)  MiaceUaneous  uses  of  blood.  Blood  is,  or 
has  been,  employed  in  a  number  of  industrial 
processes,  but  it  will  be  sufficient  here  just  to 
enumerate  a  few  of  them  :  thus  it  has  been  used 
as  a  medium  for  paints  (Johnson,  Eng.  Ftet.  82, 
1883),  in  the  preparation  of  adhesive  cements,  as 
a  precipitant  of  sewage  in  the  alum,  bloody  and. 
day  process,  and  in  the  manufacture  of  pure 
animal  charcoal. 

Tests  for  blood.  It  is  often  necessary,  in 
medico-legal  practice,  to  be  able  to  identify 
blood-stains  on  garments  and  instruments.  If 
the  blood  is  fresh*  a  microscopic  investigation 
reveals  the  presence  of  corpuscles,  and  an 
aqueous  extract  will  show  the  typical  absorption 
bands  of  hnmoglobin  with  the  spectroscopeu 
Hie  best  chemical  test  is  the  formation  of 
hesmio  crystals  already  described,  and  is  gi^ai 
bv  quite  small  quantities  of  blood,  even  if  it  is 
old  and  dry.  When  the  blood  is  dry,  and  small 
quantities  only  are  present,  the  most  deUcate 
spectroscopic  test  consists  in  dissolving  it  in 
dilute  potash  with  the  aid  of  heat^  and  then 
adding  a  drop  of  a  reducing  agent  such  as 
ammonium  sulphide;  the  two  absorption 
band^  of  reduced  hematin  are  then  seen,  one 
about  half-way   between  the  D  and  E  lines. 


BLUB,  RESOROIN,  OR  LAOMOID. 


610 


and  the  other  just  on  the  bine  side  of  the  E 
line. 

Human  blood  can  only  be  distinguiflhed  with 
certainty  from  the  blooa  of  other  animalw  by 
the  so-called  *  biological  reaction.'  The  injection 
in  sucoessiTe  doses  of  blood  of  another  species 
into  an  animal  acts  as  an  antisen,  and  causes  the 
development  in  the  blood  of  tneiniected  animal, 
of  a  specific  *  precipitin ' ;  the  addition  of  the 
blood  to  the  serum  of  the  animal  which  furnished 
the  injected  blood  causes  a  precipitate;  and 
such  a  precipitate  does  not  form  except  between 
the  Uood  of  the  two  species  of  animal  used  in 
the  experiment.  This  nas  been  applied  to  the 
case  of  human  blood,  by  taking  a  rabbit  and 
injectinff  human  blood  into  it.  The  serum  of 
this  raboit  will  then  give  a  precipitate  with  the 
blood  oi  man  (and  to  a  less  extent  of  the  higher 
apes),  and  with  the  blood  of  no  other  species  of 
animal.  The  test  is  extraordinarily  delicate, 
and  will  detect  human  blood  that  has  been  dried 
for  months,  and  even  when  it  is  mixed  with  the 
blood  of  other  animals.  W.  D.  H. 

BLOODSTONE.  A  poxmlar  name  for  the 
mineral  hdiotrope,  a  variety  of  chalcedony 
(SiOf),  showing  bright-red  nxits  on  a  dark-green 
ground.  It  is  maoh  used  tor  the  engraving  of 
rinc-stones  and  seals. 

The  same  name  has  also  been  used  for 
hamatite  (Fe,0,),  being  a  translation  of 
tUfUkrtmis,  so  called  because  the  colour  of  the 
powdered  mineral  is  like  that  of  dried  blood. 

Ii«  J.  S. 

BIX)OM.  A  term  given  to  a  mass  of 
iron  after  it  leaves  the  puddling  furnace  {v. 

IBON). 

BLOOMERT.  An  old  term  for  an  iron 
furnace. 

BLOWN  OILS  V.  Oils  and  Fats. 

BLOWPIPE  V.  Ahaltsis. 

BLUBBER  onus  v.  On^  and  Fats. 

BLUE,  ACETUf,  Coupier^s  hhte  {v.  Ihdu- 
Lnrss). 

BLUE,  ALIZARIN.  This  name  is  given  to 
dioa^nthraouinon€'guinolin€  CxfH^NO^,  and  its 
sodium  bisulphite  compound 

C„H„N0i^,Na, 

(v.  Alizabiv  and  allimd  coLOUBnro  mattbbs). 

BLUE,  ALKALI,  NICHOUON'S  BLUE  or 

SOLUBLE  BLUE  v.  Tbifebnylmxthavb  colous- 

IHO  XATTIBS. 

BLUE,  ANILINE.  GENTIAN  BLUE,'  OPAL 
BLUE,  NIGHT  BLUE,  LIGHT  BLUE,  or  FINE 
BLUE  V.  TBipmorrLMSTHANB  colovbiho  hit- 
TXBS;  alaoANiUNs  blvx. 

BLUE,  ANTWERP,  v.  PiaifXKTS. 

BLUE,  AZO-,  17.  Azo-  coloubiho  mattxbs. 

BLUE,  AZODIPHENTL,  ACETIN  BLUE, 
COUPIER*S  BLUE,  INDULIN,  FAST  BLUE  R. 
CigH.gN|Gl  (v.  Ibdulikxs). 

BLUE,  BASLE.  ToiyldimMylaminopheno- 
Ulf^minonaphihtuonntm  chloride  CttH,,N4Gl 
(v.  AZDnS  AVD  coLOinuvo  icattbbs  dxbivbd 

rBOM  THBH). 

BLUE,  BAVARIAN,  v.  Tbifbbntlmbthakb 

COLOUBINQ  icattbbs. 

BLUE,   BENZIDINE,   v.    Aso-   ooloitbiko 


BLUE  BLACK  v.  Azo-  ooLoxnBUKo  mattxbs. 

BLUE,  BLACKLET,  «.  iKDULnrss.     

BLUE,    BRILLIANT    COTTON,    METHYL 


BLUE,  METHYL  WATER  BLUE.    Soda  saU 
of    tnphsnifl'fi'rosanilinetristUphouie     add    {v, 

TBIPHSmrLMBTHAKB  OOLOUBOrO  MATTXBS. 

BLUE,  CERULEAN,  v.  PiOMxirre. 

BLUE,  CHINA,  WATER  BLUE  6  B 
EXTRA,  OPAL  BLUE,  COTTON  BLUE, 
MARINE  BLUB,  v,  I^ofhxkylmxthakb  coloub^ 

IHO  HATTBBS. 

BLUE,  CHINESB,  or  PRUSSIAN  BLUE  v. 
Cyaxidbs;  also  PioMxirTS. 

BLUE,  COBALT,  v.  Cobalt;  also  Piaiaarrs. 

BLUE,  COTTON,  v.  Tbifhxxtlmbthavb 
ooLOUBnra  xattxbs. 

BLUE,  COUPIER'S,  v.  brDnLms. 

BLUE,  CYANINE,  v,  Piohxhts. 

BLUE,  DIPHENYLAMINE,  BLEU  DIRECT 
Triphenyl'fi-rosaniline    hydrochloride    (v.    Tmi- 

TaXSYUOTBAMm  CX>L0UBaiO  MATTBBS). 

BLUE'ETHYLENE  v.  THioirnrx  coLouBoro 
mattxbs. 

BLUE,  FAST,  MELDOLA'S  BLUE,  NEW 
BLUE,  NAPHTHYLENE  BLUE.  Chloride  oj 
dimethifiphenyl-^mmonium-fi-naphthoxazine  («. 
OxAzm  ooLoxnuvo  mattxbs). 

BLUB,  FLUORESCENT,  v.  Blbu  ilvobbs- 

CBBT.  

BLUE,  GENTIAN,  SPIRIT  BLUE  O,  OPAL 
BLUE,  BLEU  DE  NUIT,  BLEU  LUMIlblE, 
FINE  BLUE,  V,  Tbithbm  ylmxthaxb  ooloub- 

UrO  MATTXBS. 

BLUE,  INDIAN,  v.  Piomxitts. 

BLUB,  INTENSE,  v.  Piomxitts. 

BLUE  IRON-EARTH.  An  earthy  blue 
variety  of  the  mineial  vivianite,  a  hvdrated 
ferrous  phosphate,  ¥e^fi^,SH.fi,  often  found  as 
a  blue  powder  encrusting  vegetable  remains  and 
bones  in  bog-iron  ore,  peat,  and  clays.    L.  J.  S. 

BLUE,  LEITCH'S,  v.  Piqmsnts. 

BLUE,  UGHT,  BLEU  LUMIERE,  LYONS 
BLUE,  OPAL  BLUE,  BLEU  DE  NUIT  v.  Tbi- 

PHXHYLMBTHAITB  OOLOUBnfQ  MATTXBS. 

BLUB,  METHYLDIPHENYLAMINE 

C„H,4N,a 

obtained  in  1874  by  Qirard  by  the  action  of 
oxalic  acid  upon  methyldiphenylamine.      Or  by 
the  action  of  copper  nitrate  (Bardy  and  Dusart). 
(^  with  chloranil  (Geigy).    No  longer  made. 
BLUE,  METHYLENE,  v.  Thionixb  ooloub- 

nro  MATTBBS. 

BLUE,  NEUTRAL,  v.  Aziiras  akd  ooloub- 

nrO  MATTBBS  DBBIVBD   XBOM  THXM. 

BLUE,  NILE,  V,  Ozazikx  coLouBura  mat- 


BLUE,     PARIS,     V.     TBrPHBXYLMnHAMx 
coLouBnro  mattxbs. 

BLUE,  PRUSSIAN,  v.  Cyahidbs;  also  Pig- 


BLUE,  QUUfOLINE,  v.  Tbifhbxylmbthahb 
coLouBnro  mattxbs. 

BLUE  RED  V.  Azo-  coloubiho  mattxbs. 

BLUB,  RESORCIN,  or  LACMOID  C„H,NO«  ? 
jjrC,H,(OH), 
probably     •  \C«H.rOH,  a  colouring  matter  ob- 

10 
I I 

Uined  by  Weselsky  and  Benedikt  in  1880,  by 
the  action  of  sodium  nitrite  on  resorcin.  Blue 
violet  powder  soluble  in  water.  Soluble  in 
alcohol  with  blue  colour  and  dark*green  fluores- 
cence.   Used    as  an    indicator  in   alkalimetry 


620 


BLUE,   SAXON. 


BLUE,  SAXON,  v.  Cobalt. 

BLUE,  VICTORIA,  v,  TBXPHSNYLMarHAVi 

OOLOUBINO  HATTBBS. 

BLUE  COPPERAS,  BLUB  STONE,  or  BLUB 
VITRIOL.    Copper  ndpJiaie  {v,  Goppxb). 

BLUE  OUM  TREE*  The  Eucalyptua  glo- 
hvhu  (Labdll.)»a  tree  commoQ  in  Tasmania  and 
South-Eastem  Australia. 

BLUE  JOHN.  A  variety  of  flnor-spar  found 
in  Derbyshire,  and  valued  for  making  ornamental 
articles  {v.  Calcium). 

BLUE  LEAD.  A  term  applied  to  galena  by 
miners  to  distinguish  it  from  white-lead  oro,  or 
carbonate. 

BLUE  PIGMENTS  v.  PiOMnns. 

BOBBINTTE  v.  Ezflosivss. 

BODY  VARNISH  v.  VABinsH. 

BOFFINITE.  An  explosive  consisting  of 
potassium  nitrate,  62-65  pts. ;  charcoal,  17-19^ 
pts. ;  sulphur,  li--2i  pts.,  copper  sulphate  ana 
ammonium  sulphate,  13-17  pts.  

BOG-BUTTER  or  BUTTRELLTTE.  A 
substance  resembling  adipocere  {q.t\),  occasion- 
ally found  in  peat  in  Ireland  and  elsewhere.  (For 
list  of  chemical  and  physical  constants  of  a  sample 
of  bog- butter  found  in  Tyrone,  v.  Radcliffe  and 
Haddocks,  J.  Soc  Chem.  Ind.  1907,  3.) 

BOGHEAD  COAL  v.  Paiiaffik. 

BOGHEAD  NAPHTHA  v,  Pabaffht. 

BOG-IRON-ORE.  An  impure  iron  hydroxide 
of  recent  formation  in  bogs  and  marshes.  It  is 
referable  to  the  mineral  species  limonite  (2Fe,0,, 
3H,0),  and,  in  fact,  this  name  (from  Xnifi^y,  a 
meadow)  was  at  first  applied  to  this  materia], 
which  is  known  in  German  as  Raseneisenstein 
or  Wiesenerz  (meadow-ore).  It  is  sometimes 
placed  under  the  species  limnite  (from  Xifomi,  a 
marsh),  to  which  the  formula  Fe,0„3H,0  is 
assigned.  It  contains  20-78  p.c.  Fe,0,,  some  silica 
and  organic  matter,  and  often  phosphates  in  con* 
siderable  amount.  The  material  Das  been  de- 
posited bv  the  oxidation,  through  the  agency  of 
aige  and  bacteria,  of  chalybeate  waters.  It  is  dug 
in  shallow  pits  in  the  peat-bogs  of  Irelanc^  the 
production  amounting  to  a  few  thousand  tons 
per  annum,  and  is  mainly  used  for  Uie  purification 
of  coal-gas.  The  Swedish  lake  ores  (sjomalm )  are 
of  the  same  nature.  L.  J.  S. 

BOG  MANGANESE,  wad,  or  earthy  mang*. 
nese  [v.  Manoakssi  and  Wad). 

BOHEMIAN  BOLE.  A  yellow  variety  oi 
bole  (q.v.). 

BOILED  OIL.    Linseed  oil  {v.  Linseed  oil). 

BOILER  INCRUSTATIONS  AND  DEPOSITS. 
The  deposition  of  insoluble  salts  directly  through 
boiling  the  water  in  boilers,  or  through  concentra- 
tion beyond  the  limit  of  solubility  ot  salts  in  solu- 
tion, or  again,  by  interaction  between  otherwise 
soluble  salts  leading  to  the  precipitation  of 
insoluble  salts,  causes  serious  trouble  in  boiler 
practice,  and  lowers  the  efficiency  of  the  boilers. 
Any  incrustation  or  scale  retards  heat  trans- 
mission to  the  water,  thereby  increasing  fuel 
consumption ;  overheating  of  the  plates  or  tubes 
may  result  in  serious  damage,  and  the  removal  of 
a  hard  scale  by  mechamcal  means  leads  to 
further  damage,  in  addition  to  the  cost  of 
removal  and  the  boiler  being  idle  for  some  time. 
If  the  deposit  remains  as  a  soft  mud,  frequent 
use  of  the  blow-off  cock  is  demanded,  and  heat 
is  lost  in  the  hot  water  blown  off ;  but  this,  of 
course,  is  preferable  to  the  accumulation  of  the 


deposit,  and  its  baking  on  the  plates  or  tubes  to 
a  hard  mass. 

The  question  of  corrosion  is  also  closely 
associated  in  many  cases  with  the  production 
of  deposits,  and  treatment  on  scientific  liq^  for 
the  removal  of  the  latter  overcomes  troubles  from 
the  former. 

Natural  waters  vary  widely  in  composition, 
and  some  are  wholly  unsuited  for  boiler  use, 
either  by  reason  of  the  formation  of  deposits 
and  scale,  or  of  their  corrosive  action.  For  the 
different  characters,  of  natural  waters  and  their 
coniposition,  see  article  on  Water. 

It  is  convenient  to  regard  deposits  bm  the 
soft  material  which  can  be  removed  as  sludge ; 
incrustations  as  deposits  more  or  less  firmly 
adherent  to  the  boiler;  and  scale  as  the  firm 
hard  material  which  can  only  be  removed  with 
difficulty,  usually  requiring  chipping  off. 
Naturally  no  hard-and-fast  Ime  can  oe  drawn 
between  these  forms. 

Either  form  is  to  be  associated  primarily 
with  the  'hardness'  of  water.  *  Temporary 
hardness,*  i.e.  hardness  removable  by  simple 
boiling,  is  due  to  calcium  and  magnesium 
carbonates  (to  a  small  extent  also  to  ferrous 
carbonate).  These  salts,  although  almost  in- 
soluble in  pure  water,  dissolve  in  the  presence 
of  carbon  dioxide,  owing  to  the  formation  of 
soluble  bicarbonates  (C;aCO,-HsCO, ;  MgCO,- 
H^COa).  One  litre  of  water  holds  about 
1*2  grams  of  calcium  carbonate  (as  bicarbonate) 
in  solution ;  after  prolonged  boiling  about 
18-20  milligrams  per  litre.  In  the  presence  of 
other  soluble  salts  the  solubility  is  iucreaaed, 
thus  with  calcium  sulphate  present  the  solu- 
bility may  be  increased  to  1-8  grams  of  CaCOs 
(as  oicarl!onate)  per  litre. 

When  water  containing  calcium  bicarbona'^c 
is  heated  to  about  65°  G.  it  begins  to  deposit 
the  normal  carbonate  in  powdery  form ;  at  a 
later  stage  the  deposit  becomes  crystalline,  and 
may  form  a  fairly  adherent  incrustation. 
Calcium  carbonate  exists  in  two  crystaUine 
forms,  cakiU  (rhombohedral,  belonging  to  the 
hexaeonal  system),  and  aragonUe  (ortho- 
rhombic,  belonging  to  the  rhombic  system). 
The  latter  is  haraer  and  denser  than  calcite,  and 
is  believed  by  some  authorities  to  be  the  cause 
of  incrustation  from  carbonated  waters.  On 
boiling  such  waters  the  precipitate  is  a  mixture 
of  calcite  and  aragonite ;  the  presence  of  other 
soluble  ftalts  favours  the  formation  of  aragonite. 

Magnesium  carbonate  behaves  somewhat 
differently,  several  intermediate  hydroxv-  car- 
bonates bdng  formed,  the  composition  of  which 
is  dependent  on  temperature.  Bv  continued 
boiling  in  the  presence  of  water  at  high  tempera- 
tures (under  pressure)  maffnesium  carbonate 
forms  the  hydroxide  (Mg(HO)t),  with  liberation 
of  carbon  dioxide,  and,  accordiog  to  J.  H.  Paul, 
insoluble  magnesium  oxide  may  even  result. 
W.  A.  Davis  (J.  Soc.  Chem.  Ind.  1906,  788) 
found  that  on  heating  an  alkaline  solution  of 
magnesium  bicarbonate  to  60°  in  a  partially 
dorod  flask,  the  precipitate  was  MgCOs'SH^O. 
At  100°  it  lost  water  (2H.0),  and  at  125°  the 
third  molecule,  toffetfaer  with  carbon  dioxide. 

A  table  of  solubility  of  maffnesium  carbcmato 
in  water  containing  carbon  dioxide  at  various 
pressures    will    be    found     under    Maokmitm 

OABBONATB. 


BOILER  INCRUSTATIONS  AND  DEPOSITS. 


621 


Solutions  of  magnesium  carbonate  decom-i 
pose  much  more  slowly  on  boiling  than  those  of^ ' 
calcium  bicarbonate,  but  the  precipitation  is 
more  complete.    In  peaty  waters  the  deposition 
of  both  carbonates  is  considerably  retarded  and 
may  be  prevented. 

Ferrous  carbonate  behi^yes  similarly  to 
calcium  carbonate. 

The  *  permanent  hardness '  is  due  chiefly  to 
the  sulphates  of  calcium  and  magnesium ;  to  a 
minor  extent  to  the  chlorides  and  nitrates  of  these 
metals.  Boiling  at  ordinary  pressure  does  not 
cause  the  deposition  of  any  oi  these  salts,  pro- 
yiduiff  the  water  does  not  become  too  concen- 
trated. On  the  other  hand,  boUing  at  the  higher 
pressures  existing  in  boilers  almost  oom]^ete 
precipitation  of  calcium  sulphate  occurs,  and 
this  constitutes  the  most  troublesome  constituent 
in  boiler  waters,  being  very  largely  responsible 
for  the  formation  of  hard  adherent  scales. 

Calcium  sulphate  (CaS04)  is  practically  in- 
soluble in  water.  It  occurs  naturally  in  the 
hydrated  form  (CaS04*2H,0)  as  gypsum.  Two 
varieties  of  the  anhydrous  sulphate  are  recog- 
nised ;  insoluble  and^soluble  anhydrite^  The 
solubility  of  natural  gypsum  attains  a  maximum 
at  32''  C,  100  parts  of  water  dissolving  0-2096 
part.  At  10""  C.  the  solubility  is  01929 ;  at 
100'',  0-1620  (Hulett  and  Allen,  J.  Amer.  Chem. 
Soc.  1902,  24,  667).  Much  stress  has  been  laid 
on  the  decreasing  solubility  with  rise  of  tempera- 
ture as  the  important  factor  in  causing  deposition 
in  practice,  but  since  the  amount  of  calcium 
sulphate  is  generally  much  below  the  limit  of 
solubility  at  100°,  it  seems  impossible  that  it  can 
be  an  important  factor.  According  to  Silchester, 
at  low  boiler  pressure  (28-29  lbs.)  water  contain- 
ing the  salt  will  concentrate  like  other  waters 
without  scale,  but  at  higher  pressures  (40-50  lbs.) 
will  deposit,  due  to  the  formation  of  a  hemi- 
hydrate,  2CaS04'H20,  at  a  temperature  of 
107°.  This  has  be^  recognised  by  Johnston 
in  scale  from  boilers  working  at  2  atmos. 
Above  130°  the  ankydrous  calcmm  sulphate  is 
formed.  These  are  salient  facts  in  the  formation 
of  hard  scales  due  to  this  salt,  for  it  is  evident 
that  it  is  not  a  question  of  concentration  above 
the  limit  of  solubiUty  of  CaSO^^H.O,  but  the 
definite  formation  of  another  phase,  and  the 
material  being  practically  insoluble  in  this  phase 
is  almost  completely  precipitated  even  when 
present  in  very  small  amount  in  the  water. 
130°,  or  perhaps  a  little  lower,  may  be  regarded 
as  the  critical  point  determining  the  precipita- 
tion of  calcium  sulphate. 

The  solubility  is  increased  by  the  presence  of 
othermore  soluble  saltssuch  as  sodium  cnloride  and 
sulphate,  and  calcium  sulphate  may  concentrate  to 
a  fairly  high  degree  in  a  ooiler  water,  as  is  shown 
by  the  f oUowing  analysis  by  J.  C.  W.  Greth : — 

Grains  per  Imperial 
gallon 
Volatile  and  organic  matter  .     6*04 

Silica 0*66 

Calcium  carbonate         •         .1-20 

Calcium  sulphate  •         .94*56 

Magnesium  sulphate      .         •7*63 

Soiuum  chloride   .         .         .12-66 

Sodium  sulphate  .         .    23*77 

Other  constituents  of  natural  waters,  such  as 

calcium    chloride,    magnesium    sulphate    and 

chloride,  often  play  an  important  part  in  the 

formation  of  scale  by  interaction;    thus  mag- 


nesium sulphate,  although  so  soluble  that  it 
should  never  form  part  of  a  scale  under  proper 
working  conditions,  may  be  almost  as  trouble- 
some as  calcium  sulphate,  since  with  calcium 
carbonate  or  chloride  it  reacts  with  the  formation 
of  calcium  sulphate  and  magnesium  carbonate 
or  chloride. 

Formation  of  scaU, — ^Waters  which  are  in  the 
main  temporarily  hard  will  deposit  the  carbon- 
ates of  calcium  and  masnesium  (also  ferrous, 
carbonate,  if  present),  either  in  the  boiler  or 
feed-water  heaters  by  the  simple  dissolution  of 
the  bicarbonates.  Such  deposits  are  usually 
powdery ;  in  the  presence  of  organic  matter 
they  seldom  form  c<merent  deposits,  and  so  may 
be  got  rid  of  by  the  sludge  cock.  Under  some 
conditions,  however,  the  deposits  bake  on  the 
plates  or  tubes  and  form  incrustations.  Further, 
on  concentration  of  the  water  other  seJts  in 
solution,  like  magnesium  or  sodium  sulphate, 
may  react  on  the  incrustation  with  the  formation 
of  calcium  sulphate  and  produce  a  much  harder 
deposit — a  true  scale.  Similarly,  an  incrustation 
containing  magnesium  hydroxide  may  react 
with  magnesium  chloride  and  form  a  hard 
incrustation. 

The  deposition  of  the  carbonates  is  a  gradual 

Srocess  so  that  a  temporarily  hard  water  which 
eposits  much  of  its  calcium  carbonate  in  the 
feed-water  heaters,  but  less  of  the  magnesium 
carbonate  because  of  its  slower  rate  of  de> 
position  on  heating,  will  continue  to  deposit  in 
pipes,  and  such  deposit  will,  for  the  same  reason, 
contain  a  higher  proportion  of  magnesium 
carbonate.  Such  actions  are  modified  by  the 
presence  of  other  salts;  thus,  according  to 
Fetit,  sodium  chloride  reduces  the  proportion  of 
lime  and  increases  that  of  magnesium,  whilst 
magnesium  sulphate  causes  more  lime  to  be 
retained  in  solution. 

Calcium  sulphate,  whether  present  as  such 
or  formed  by  interactions  on  concentration  of 
the  water,  becomes  deposited  in  the  anhydrous 
form  as  soon  as  the  temperature  is  above  that 
corresponding  to  the  phases  CaS04-2H|0  or 
CaS04'H20.  It  forms  an  extremely  hard  scale 
of  itself.  If  deposited  amongst  the  precipitated 
carbonates  it  acts  as  a  binder,  and  may  form 
hud  incrustations  or  scales.  Its  deleterious 
action  may,  therefore,  be  far  greater  than  the 
mere  proportion  present  would  indicate.  Calcium 
sulphate  is  throughout  the  most  important 
factor  in  the  formation  of  hard  incrustations  and 
true  scales. 

In  broad  terms,  whilst  the  carbonated  waters 
(temporary  hard)  form  soft  easily  removed 
deposits  or  incrustations,  and  waters  containing 
caesium  sulphate,  or  salts  liable  to  form  it  by 
interaction  (permanently  hard),  produce  haid 
scales,  and  serve  to  bind  loose  incrustations  into 
harder  masses,  such  a  generalisation  must  only 
be  accepted  as  broadly  true,  for  exceptions  are 
not  infrequent  under  the  varying  composition 
of  natural  waters  and  conditions  of  practice. 

Magnesium  hydroxide  (Mff(HO)t)  with  mag- 
nesium chloride  forms  a  hard  material ;  certam 
covering  compositions  for  ships*  decks  are  made 
on  this  basis.  In  the  presence  of  calcium  sul- 
phate these  salts  form  very  hard  porcelain-like 
scales,  which  are  extremely  difficult  to  remove. 
According  to  J.  H.  Paul,  the  tidal  waters  of  the 
Thames  give  such  a  scale,  the  composition  being 


622 


BOILER  INCRUSTATIONS  AND  DEPOSITS. 


very    constant    between    85-87    p.c.    calciun^ 
sulphate,  and  10-13  p.c.  ma^esiam  hydioxid^ 
which  approximately  agrees  with  a  molecalar 
composition  3CaS04-Mg(HO),. 

Under  bad  conditions  of  working  the  concen- 
tration of  the  water  in  a  boiler  is  sometimes 
allowed  to  increase  to  such  an  extent  that 
soluble  salts  are  deposited  along  with  the  true 
incrustation-formins  solids.  Paul  sives  the 
composition  of  such  a  scale  from  a  feed-water 
containing  20  erains  of  lime  and  magnesia,  and 
40  grains  of  sodium  salts  per  gallon  as': — 
Calcium  carbonate  .  .3*80  p.c. 
Magnesium  carbonate    .         .1*16  „ 

Silica 0-69  „ 

Iron  oxide   .         .         .         ,     0-77  „ 

Sodium  chloride   .         .         .    77*09  „ 

Sodium  sulphate  .         .         .    11*82  „ 

Sodium  car  Donate  .     3*62  „ 

Combined  water  .  5*96  „ 

Ninety-five  p.c.  of  this  hard  tough  crystalline 

scale  was  soluole  in  water.    The  removal  of 

scales  of  this  *  soluble '  type  is  simple,  it  being 

only  necessary  to  blow  down  the  boiler  and  fifi 

up  with  fresh  water  and  again  empty. 

The  formation  of  scale  from  sea  water  is  a 
matter  of  some  importance,  for  although  the 
use  of  sea  water  in  boilers  has  been  almost 
entirely  discarded  in  favour  of  the  use  of  distilled 
water  for  the  *'  make  up,*  made  in  the  ship^s 
evaporating  plant,  yet  sea  water  frequently 
finos  its  wav  into  the  feed  from  leaky  con- 
densers, or  through  priming  in  the  evaporator. 
The  scale  from  sea  water  is  mainly  calcium  sul- 
phate, together  with  magnesium  hydroxide  and 
silica,  f^equentlv  the  scale  can  be  separated 
into  a  hard  and  soft  portion,  the  latter  containing 
a  considerably  higher  proportion  of  magnesium 
hydroxide.  The  calcium  sulphate  may  be 
between  80-90  p.c,  magnesium  hydroxide 
2-5  p.c,  calcium  carbonate  is  usually  under 
1  p.c  One  ton  of  sea  water  contains  about 
3*5  lbs.  of  scale  forming  salts,  of  which  a  little 
over  3  lbs.  is  calcium  smphate. 

With  low-pressure  boilers  it  was  possible 
to  evaporate  sea  water  without  any  serious 
trouble,  providing  the  density  was  not  allowed 
to  become  excessive  (according  to  Lewes,  to  a 
density  of  1*09  without  deposition  of  calcium 
sulphate),  but  with  modem  boilers  working  at 
hign  pressures,  so  that  the  boiling-point  was 
raised  above  the  critical  temperature  of  de- 
position of  calcium  sulphate  in  brine  solution, 
troubles  from  scaling  became  so  developed  that 
the  use  of  such  water  in  these  boilers  had  to  be 
abandoned. 

The  formation  of  magnesium  hydroxide  is 
probably  due  to  the  interaction  of  the  concen- 
trated solution  of  magnesium  chloride  on  the 
small  amount  of  calcium  carbonate  which  would 
be  the  first  substance  to  deposit,  the  magnesium 
carbonate  formed  later  losing  carbon  dioxide. 
Such  a  reaction  accounts  for  the  very  small 
quantity  of  calcium  carbonate  in  the  scale. 
Magnesium  hydroxide  may  also  partly  result  bv 
direct  liydrolysis  of  magnesium  chloride  which 
takes  place  readily  in  contact  with  heated  iron. 
Hydrochloric  acid  is  set  froo,  and  this  is  closelv 
associated  with  corrosion  of  the  boiler  on  which 
it  acts  with  the  production  of  ferrous  chloride, 
this  further  reacts  with  magnesium  hydroxide 
precipitating  black  ferrous  oxide  (or  hydroxide) 


in  the  absence  of  air.  Free  hydrochlorio  acid 
and  iron  are  thus  not  found  in  the  water ;  indeed 
the  water  is  slightly  alkaline,  due  to  the  solu- 
bility of  the  excess  of  magnesium  hydroxide. 

Pbevxntion  of  Scalb. 

The  treatmei^  of  water  to  prevent  the 
formation  of  incrustations  or  scale  may  eiUier 
be  preparatory  to  its  use  in  the  boiler,  or 
chemicals  (generally  sold  as  '  boiler  fluids ')  may 
be  added  £rom  time  to  time  to  the  water  in  the 
boiler.  In  the  latter  case  prevention  of  trouUe- 
some  scale  may  be  ppssible,  the  added  firnds 
causing  precipitation  in  a  form  which  can  be 
easily  removed  by  the  sludge  cock,  but  unleas  all 
scale-forming  materials  can  be  kept  in  solution, 
an  almost  unroalisable  condition,  it  is  cleai^ 
more  satisfactory  to  remove  the  causes  of  troubJe 
before  the  water  enters  the  boiler. 

There  is  no  relationship  between  the  amount 
of  impurity  in  a  water  and  its  scale  forming 
charactei*,  since  concentration,  will  soon  increase 
the  quantity  from  even  a  very  pure  water.  The 
essential  point  is  the  character  of  the  dissolved 
solids,  and  accurate  analysis  is  essential  both 
from  the  point  of  view  of  determining  suitability 
for  boiler  use,  and  the  correct  system  of  treat- 
ment neoeoaary  to  render  a  natural  watec 
suitable. 

With  purely  carbonated  waters  treatment  in 
a  special  torm  of  heater,  whereby  the  calcium  and 
magnesium  carbonates  are  to  a  considerable 
extent  precipitated,  may  be  satisfactory,  but  in 
ffeneral  chemical  processes  are  employed. 
Although  a  laige  number  of  reagents  have  been 
proposed  and  adopted  with  success  in  %>ecial 
cases,  three  only  find  extended  use,  namely,  lime 
(as  milk  of  lime  or  as  clear  lime-water),  sodium 
carbonate  (soda  ash),  and  sodium  hydroxide 
(caustic  soda).  The  action  of  lime  on  the 
bicarbonates  is 

CaCO,*H,CO,H-Ca(HO),=2CaCO,+2H,0 
MgCO,*H,COs+Ca(HO), 

=CaC0,+MgC0,+2H,0 
The  removal  of  calcium  carbonate  is  never  quito 
complete,  and  the  reaction  is  still  lees  complete 
with  magnesium  bicarbonate. 

It  can  be  ascertained  when  lime  has  been 
added  in  the  requisite  slight  excess  by  the 
yellowish  brown  colouration  the  water  gives 
with  silver  nitrate  solution. 

lime  has  no  action  on  the  salts  which  cause 
permanent  hardness,  so  that  it  is  seldom 
employed  alone,  but  generally  in  conjunction 
witn  soda  ash  or  caustic  soda.  Either  or  both 
of  these  reagents  may  be  employed  without 
lime,  and  mil  remove  both  temporary  and 
permanent  hardness  under  suitable  condutions. 
Soda  ash  reacts  as  follows : — 
CaC0,*H,COa-fNa,C0,=CJaC0.+2NaHCO, 

At  temperatures  above  160^  the  sodium 
bicarbonate  is  converted  into  the  normal  car- 
bonate again,  and  carbon  dioxide  is  liberated. 

With  caustic  soda  the  reaction  is  similar, 
so  that  theoreticaUv  a  small  amount  of  either 
reagent  ia  capable  oi  dealing  with  the  temporary 
haraness  of  a  large  quantity  of  water,  but  there 
is  always  the  liability  of  the  water  becoming 
unduly  alkaline  by  concentration. 

With  magnesium  bicarbonate  it  is  frequently 
found  that  when  the  correct  quantity  of 
alkaline  carbonate  or  hydroxide  is  added  there 


BOILER   INCRUSTATIONS  AND  DEPOSITS. 


623 


is  no  precipitation  in  the  cold.  W.  A.  Davis 
(I.e.)  states  that  this  is  due  to  the  formation  of 
the  soluble  salts 

MgHCO,-COs.Na  or  Mg(CO,-Na)„ 
according  to  the  proportions  used.  Precipita- 
tion only  occurs  when  the  liquid  is  heated 
sufficiently  to  decompose  these  soluble  double 
salts  when  a  mixture  of  magnesium  hydroxide 
and  a  basic  carbonate,  ]^(OH)'(H*CO,),  is 
precipitated.  Consequently  oelow  a  certain 
temperature  it  is  impossible  to  completely 
soften  magnesian  waters  containing  small 
quantities  of  the  bicarbonate,  sulpnate  or 
chloride  by  means  of  either  sodium  carbonate 
or  hydroxide. 

U  follows  that  a  water  containing  magnesium 
salts  if  treated  by  these  chemicals  in  the  cold 
will  deposit  sludge  or  form  an  incrustation  in  a 
boiler  or  in  feed- water  heaters. 

The  action  of  sodium  carbonate  on  calcium 
or  magnesium  sulphate  causes  precipitation 
of  the  respective  carbonates  and  the  formation  of 
sodium  sulphate.  Sodium  hydroxide  forms 
calcium  hyc&oxide  and  sodium  sulphate,  and 
the  calcium  hydroxide  may  then  react  on  the 
salts  causing  temporary  hardness,  if  these  latter 
have  not  already  been  acted  on  directly  according 
to  the  equation 
CaCO,H,CO,+2NaOH 

=CaC0,-fNa,C0,+2H,0 

With  these  soluble  alkalu  it  is  important 
to  note  that  the  water  will  be  left  with  free 
alkali  in  solution  if  the  salts  causing  temporary 
hardness  are  in  excess  of  the  molecular  equiva- 
lent of  those  causing  permanent  hardness. 
With  calcium  sulphate,  on  the  other  hand,  in 
excess,  or  in  molecular  proportion,  the  sodium 
will  all  remain  as  sulphate 

CaCO,H,CO,-|-Na,CO,=CaC03+2NaHCO, 
(Mol.  Wt.  100). 
Above  160*^  C.  2NaHC0,=Na,C0,+H,0-i-C0, 

CaS04+Na,CO,=CaCO,+Na,S04 
(Mol.  Wt.  136). 

Accumulation  of  free  alkali  in  boiler  waters 
is  objectionable ;  it  is  commonly  associated  with 
priming  or  foaming,  and  if  the  solution  be  at  all 
concentrated,  may  cause  attack  of  brass  boiler 
fittings  and  even  of  the  gauge  glass.  For 
certain  industrial  purposes  also  alkalme  water  is 
inadmissible  ;  for  example,  in  affecting  delicate 
shades  of  colour  in  dyeing,  and  in  the  preparation 
of  tan  liquors. 

Caustic  soda  requires  using  with  discretion. 
It  finds  most  useful  application  with  waters 
containing  the  sulphates,  chlorides  and  nitrates 
of  calcium  and  magnesium. 

Other  chemicals  which  have  been  employed 
include  magnesium  oxide  (or  hydroxide), 
barium  hydroxide  and  chloride,  and  the  oxalates 
of  potassium  and  sodium,  but  as  they  offer  little 
advantage  over  lime  and  soda,  and  are  very 
much  more  expensive,  they  are  but  seldom 
epiployed.  Aluminium  sulphate,  alum  solution, 
or  sodium  aluminate  are  sometimes  employed. 

A  most  successful  system,  both  for  boiler  and 
industrial  purposes,  is  the  Permniiie  process, 
and  this  gives  an  almost  perfectly  softened  water, 
and  the  process  is  one  requiring  the  minimum  of 
plant,  it  oeing  simply  necessary  to  pass  the  water 
through  vessels  containing  the  material.  This  is 
an  aHificial  aseolite  made  by  fusing  together 
silica,   alumina   (or   China   clay)   and   sodium 


carbonate,  and  extracting  the  soluble  portion 
with  water.  The  crystalluie  product  is  a  double 
silicate  of  alumina  and  soda,  approximating 
to  the  composition  AlaO,*Na,0'4Si02'5H,0. 
Generally  a  portion  of  the  soda  is  replaced  by  a 
small  quantity  of  potash  (K,0)  and  Ume. 

Water   is   passed   through    the    crystalline 
material  when  the  sodium  is  replaced  quantita- 
tively by  other  metals,  such  as  lime 
AljO  jNajO  -4810,+ CaCO  ,H,CO, 

=Al,0,CaO-4SiO,-f2NaHCOa 
Al,0,Na,0.4SiOg+CaS04 

=Al,0,CaO-4SiO,+Na,S04 

The  permutite  may  be  regenerated  when 
exhausted  by  passing  strong  brine  through  it, 
and  this  therefore  is  practically  the  only 
softening  agent  consumed. 

With  the  ordinary  permutite  waters  contain- 
ing iron  cannot  be  treated,  and  a  special  form 
containing  a  proportion  of  the  higher  oxides 
of  manganese  is  used.  This  causes  oxidation 
of  ferrous  to  ferric  salts',  which  are  precipitated. 

According  to  Bahrdt  the  reactions  between 
the  alkaline  earth  metals  and  permutite  are 
reversible,  cmd  calcium  can  displace  magnesium 
from  magnesium  permutite  if  first  formed,  and 
more  magnesium  may  at  times  be  present  in  the 
treated  than  in  the  untreated  water.  Bahrdt 
therefore  recommends  prior  removal  of  the 
temporary  hardness  by  lime  and  confining  the 
permutite  treatment  to  the  removal  of  permanent 
hardness.  Such  treatment  would  require  to  be 
carefully  controlled,  as  a  too  highly  alkaline 
water  spoils  permutite. 

The  point  must  be  emphasised  that  whilst 
with  lime  in  the  correct  proportion  to  remove 
temporary  hardness  the  precipitate  is  wholly 
insoluble^  and  no  soluble  salts  are  formed,  with 
practically  all  other  reagents  an  insoluble  and 
soluble  salts  are  formed.  The  latter  will  increase 
by  concentration  in  the  boiler,  and  care  must 
be  taken  that  this  does  not  become  excessive. 
Especially  is  this  important  where  the  soluble 
salt  is  alkaline. 

Softening  piant.  Numerous  forms  of  plant 
are  employed  for  carrying  out  the  softening 
process  ;  in  some  the  sludge  ii  allowed  to  settle, 
two  tanks  being  used  alternately.  To  decrease 
the  settling  period  the  sludge  is  generally  stirred 
up  with  the  fresh  charge,  and  since  the  upper 
portion  of  the  water  clarifies  first  consideraole 
saving  of  time  (and  consequent  reduction  in 
size  of  tanks)  is  possible  bv  the  use  of  a  draw-off 
pipe  carried  by  a  float.  Many  softening  plants 
are  provided  with  automatic  means  of  measuring 
in  the  required  reagents  in  the  proportion 
determined  by  analysis,  also  with  mechanically 
operated  stirrers  and  suitable  filtering  arrange- 
ments. It  has  been  found  that  the  softening 
process  is  more  complete  when  there  is  an 
accumulation  of  precipitated  material  in  the 
filters,  which  sugja^ests  that  the  action  of  the 
sludge  left  in  settlmg  tanks  is  beneficial  beyond 
its  mere  mechanical  action  in  promoting 
clarification. 

With  waters  softened  by  the  lime-soda 
treatment,  even  with  heat,  the  actions  are  often 
not  completed  in  the  tanks,  and  deposits  are 
found  in  the  feed- water  heaters  and  pipes. 
These  incompleted  reactions  are  primarily  due 
to  magnesium  salts,  the  behaviour  of  which  has 
already   been   referred  to.    In  the  Archbutt- 


624 


BOILER  INCRUSTATIONS  AND  DEPOSITS. 


Dcely  process  this  trouble  is  overcome  by 
passing  carbon  dioxide  into  the  softened  water, 
the  gas  being  drawn  oflf  from  a  coke  fire,  freed 
from  sulphur  dioxide  by  limestone,  and  injected 
by  the  steam  blower,  which  serves  to  draw  the 
gases  from  the  small  producer. 

BoiLBB  Fluids. 

The  use  of  an  anti-incrustation  fluid  in  the 
boUer  is  greatly  favoured  by  many  engineers, 
but  is  not  such  a  satisf aotorv  method  of  treatment 
as  the  prior  removal  of  the  scale-forming  con- 
stituents. The  method  has  the  advantage  of 
requiring  no  external  plant,  and  for  one  or  two 
boilers  this  is  an  advantage;  but  for  larger 
installations  a  proper  softening  plant  is  better 
and  more  eeneral  in  practice.  It  is  obvious  that 
precipitation  of  any  solids  by  the  boiler  fluid 
takes  place  in  the  boiler,  and  the  sludjze  so  formed 
must  oe  blown  out  at  intervals.  Some  of  the 
compounds  used  are  not  without  action  on  boiler 
plates,  tubes  and  fittings,  especially  copper  alloys. 

Sodium  carbonate  and  hydroxide  with  waters 
containing  little  of  the  bicarbonates  of  lime  and 
maffnesium,  especially  if  the  water  is  slightly 
acid,  give  good  results.  With  carbonated 
waters  the  alkali  will  not  be  used  up  and  the 
water  may  become  objectionably  alkaline. 

Ammonium  chloride  reacts  with  calcium 
carbonate,  producing  calcium  chloride  and 
ammonium  carbonate,  and  the  latter  is  decom- 
posed at  boiler  temperatures,  ammonia  escaping 
m  the  steam.  With  magnesium  salts  magnesium 
chloride  may  be  formed,  and  this  is  an  active 
corrosive  agent. 

Sodium  phosphate  (Na,HP04'12HsO)  is 
suitable  for  sulphated  waters.  Bicarbonates 
are  also  decomposed,  apparently  throuffh  hydro- 
lysis of  the  safi*  in  solution  with  the*formation 
of  a  small  amount  of  sodium  hydroxide. 

Sodium  sulphite  and  silicate  are  also  some- 
times employed.  The  former  precipitates 
calcium  sulphite,  which  is  slowly  oxidised  to 
sulphate,  in  a  non-crystalline  form  so  that  it  can 
be  olown  off.  Sulphites  are,  however,  likely  to 
cause  corrosion,  especially  in  the  presence  of 
nitrates,  which  become  reduced  to  nitrites,  and 
as  these  decompose  active  corrosion  may  result. 
The  objection  to  sodium  silicate  is  its  liability 
to  harden  otherwise  soft  incrustations. 

Many  organic  substances  of  *the  most  varied 
character,  starchy,  albuminous  and  gelatinous 
materials,  are  used.  The  general  action  appears 
to  be  due  to  their  colloidal  character,  which 
prevents  the  formation  of  crystalline  deposits. 

Tannic  acid,  or  sodium  tannate,  have  been 
widely  employed.  The  free  acid  decomposes 
ike  carbonates  with  the  formation  of  insoluble 
tannates.  Tannic  acid  may  act  on  the  iron,  and 
should  only  be  used  with  alkaline  waters,  and 
then  under  careful  chemical  supervision. 
Alkaline  solutions  containing  more  or  less  sodium 
tannate  are  frequently  employed,  but  it  is 
probable  that  the  anti-incrustation  action  is 
mainly  physical  and  due  more  to  the  organic 
extractives  than  the  sodium  tannate  itself, 
except  in  so  far  as  the  alkali  itself  acts  in 
accordance  with  reactions  already  dealt  with. 

Oily  Dbposits. 
The  presence  of  oil  globules  carried  into  the 
boiler  by  the  condensed  steam  from  the  cylinders 
has  been  the  cause  of  several  boilers  collapsing. 


owinf  chiefly  to  overheating  of  the  crown  plates 
of  we  furnace.  Even  with  good  mineral 
cylinder  oils  a  process  akin  to  steam  distillation 
may  take  place,  so  that  portions  of  the  oil 
normally  of  higher  boiling-point  than  the 
temperature  of  the  steam  are  carried  forward  in 
the  condensed  feed-water.  These  oily  globules 
attach  themselves  to  any  precipitated  cart>onates 
or  sulphates,  rendering  tne  material  lighter,  so 
that  it  is  carried  freely  by  the  convection 
currents  until  meeting  highly  heated  metal 
surfaces  it  becomes  deposits.  It  is  character- 
istic of  such  deposits  that  they  occur  as  fre- 
quently on  the  underside  of  tubes  as  on  the  upper 
side  (where  non-oily  incrustations  are  usually 
much  thicker),  this  being  due  to  this  circulating 
action.  Frequently  all  oil  may  disappear  from 
the  incrustation,  owing  to  excessive  heating 
of  the  metal  in  contact  with  it. 

Another  action  not  generally  recognised  is 
that  some  oils  derived  solely  from  petroleum 
(mineral  oils)  are  liable  to  oxidation  with  the 
formation  of  acids  akin  to,  if  not  identical  with, 
fatty  acids,  and  these  form  insoluble  soaps  with 
lime  and  magnesia.  With  the  latter  m  par- 
ticular the  soap  is  of  an  adhesive  character,  it 
collects  other  floating  solids,  and  deposits  a  mass 
on  plates  and  tubes.  The  free  staoB  also  attack 
copper,  lead  and  zinc  of  brass  fittings,  and  the 
salts  of  these  metals  are  frequently  found  in  the 
incrustation.  Paul  has  published  analyses  of 
several  such  deposits,  a  typical  one  from  a 
whoUy  mineral  oil  being  : — 

Uncombined  oil    .         •         .   49*99  p.o. 
Combined  oily  acids      •         .     6*72  „ 
Zinc  oxychloride  •         .    22*79  „ 

Lead  oxide  ....  0*47  ,» 
Oopper  oxide  .  .  .  •  0*10  „ 
Feme  oxide  .         .  7*02  „ 

Magnesium  oxide  .         .    11*90  ,, 

SiUoa 110  „ 

When  mixtures  of  saponifiable  and  non- 
saponifiable  oils  were  employed  for  cylinder 
lubrication  the  formation  of  fatty  acids  which 
passed  to  the  boUer  feed  water  was  much  more 
serious,  and  led  to  the  abandonment  of  saponi- 
fiable oils.  With  boilers  working  at  the  high 
pressures  now  common,  especially  m  conjunction 
with  high  super-heat  of  the  steam,  it  has  become 
a  most  important  matter  to  select  only  cylinder 
oils  of  the  highest  quality,  free  from  tendency  to 
form  acids.  In  every  case  where  condensed 
water  is  used  it  is  most  essential  to  instal 
efficient  means  of  removing  oil,  either  in  exhaust 
steam  separators  or  feed-water  filters.  Alu- 
minium sulphate  or  alum  have  been  employed 
with  success  to  aid  the  separation  of  the  emulsi- 
fied oil,  the  aluminium  hydroxide  formed  by 
precipitation  with  any  alkali  present  collecting 
the  oil  globules,  and  their  removal  by  filtration 
is  facilitated.  J.  S.  S.  B. 

BOIS-PIQUAIIT  BARK.  The  bark  of  Zan- 
thoxylum  cariboeum  (Lam.),  and  Z.  PerrcUeUi 
(D.C.).  Used  in  France  as  a  febrifuge  (Heckel  a. 
Schlfu^denhaffen,  Oompt.  rend.  98,  996). 

BOLDO.  A  shrub,  Peumus  hMtu  (Molina), 
belonging  to  the  Monimiaceca,  growing  in  the 
Chilian  Andes.  The  bark  is  used  in  tannine,  the 
wood  makes  a  good  charcoal,  and  the  bark  and 
leaves  contain  a  glucoside  CaoHs,0«,  useful  as  a 
hypnotic  and  cholagogue  (Chapoteau,  Oompt. 
rend.  98,  1062). 


BONE. 


626 


BOLE.  (Bd,  Ger.)  A  ferroginona  clay-like 
substanoe^  of  red,  brown,  or  yellowish  colour.  It 
IB  not  plastio,  and  when  thrown  into  water 
falls  to  pieces  with  emission  of  streams  of 
minute  air-bubbles.  It  has  an  unctuous  feel, 
and  some  yarieties  adhere  to  the  tongue.  When 
out  it  presents  a  shining  streak.  Before  the 
blowpipe  it  fuses  to  a  yellowish  or  white  enamel. 
Its  composition  is  very  variable,  but  its  usual 
limits  are  from  41  to  47  p.c.  SiO„  18  to  26  p.c. 
A1,0,  and  24  to  26  p.o.  H.O,  with  a  proportion 
of  Fe^O,,  which  may  reach  12  p.o.  It  will  be 
noticed  that  the  percentage  of  water  is  higher 
than  in  clays.  The  Fettbol  of  Freiberg  in 
Saxony  occurs  in  mineral  yeins,  and  contains 
only  about  3  p.c.  of  Al,Ot.  The  bole  of  Stolpen 
in  Saxony  is  a  yellowish  substance  containing 
only  a  trace  of  F.'tOs.  Rammelsb^v's  analysis 
yielded  SiO,.  4692  ;  A1,0„  2214  ;  CaO,  3*9  ; 
HaO,  26-86.  In  the  '  bole  of  Sinope  '  (sinopite) 
from  Asia  Minor  the  SiO,  falls  as  low  as  32  p.c. 
The  ancients  obtained  this  material  from 
Gappadocia,  and  used  it  as  a  red  pigment.  It 
was  also  employed  in  medicine  as  an  astringent 

{v.  LlMNIAK  EaBTIT). 

The  following  is  an  analysis  of  bole,  occurring 
in  granite,  at  Steinkirchen,  Bohemia. — ^Dried 
at  rOO**  it  yielded  SiO„  46-73 ;  A1,0„  2617  ; 
Fe,0„  12-34;  CaO,  1-64;  MgO,  1-31 ;  K,0, 098; 
MnO,  0-28 ;  loss  on  ignition,  1063  (6.  Starkl, 
Verb.  k.  k.  Geolog.  Reichs.  Vienna,  1880, 
279). 

Bole  IS  frequently  found  as  a  product  of  the 
decomposition  of  basaltic  rocks.  Thus  the 
sheets  of  basalt  in  N.E.  Ireland,  representing 
Tertiary  laya-flows,  are  separated  by  partings  ol 
bole,  associated  with  lithomaiffe,  bauxite, 
pisolitic  iron-ore,  and  seams  of  lignite.  The 
Antrim  bole  is  described  as  a  poor  variety  of 
aluminous  iron-ore  (0.  A.  J.  Cole,  The  inter- 
basaltic  rocks  (iron  ores  and  bauxites)  of  north- 
east Ireland,  Mem.  Geol.  Survey,  Ireland,  1912). 

L.  w.  S. 

BGLOGNIAN  STONE.  A  native  variety  of 
barium  sulphate  found  as  nodular  massej 
embedded  in  clay  near  Bologna ;  when  partially 
reduced  to  sulphide  by  calcination  with  charcoal 
it  exhibits  phosphorescence.  Vanino  and  Zum- 
busch  (J.  prakt.  Chem.  1911,  84,  306)  have 
attempted  to  ascertain  the  factors  which 
determine  the  phoephoreyent  queJity  of  Bologna 
stones.  Good  samples  may  vary  in  sulphur 
content  between  12  and  33  p.c.  Marked  phos- 
phorescing power  seems  to  depend  upon  the 
presence  of  polysulphides ;  produc'a  containing 
only  monosmphide  are  deficient  in  this  respect. 
The  presence  of  calcium  oxide  appears  to  increase 
the  phosphorescing  power  (v.  Babium  and 
Barytbs). 

BOLORETIN  v.  Resins. 

BOMBICBSTOROL  v.  Stsrols. 

BONE.  Bony  tissue  may  be  either  compact 
as  in  the  shafts  of  the  long  bones,  or  sponsy  or 
oanceUated  as  in  the  flat  Iranes  of  the  SKulTand 
in  the  extremities  of  the  lonff  bones;  here  an 
external  compact  layer  encloses  a  mass  of 
spongy  bone  or  diploS.  From  the  embryolo^ical 
point  of  view,  bones  may  be  divided  into 
cartilage  bones  and  membrane  bones.  The 
cartilage  bones  are  those  which  in  embryonic 
life   are   preceded    by   cartilaginous    profignro- 

Vou  I.— r. 


menta;  these  oomprise  the  majority  of  the  bones 
in  the  body,  and  include  all  the  long  bones  except 
the  clavicle.  In  the  case  of  membrane  bones 
(for  instance,  the  flat  bones  of  the  cranium),  there 
is  no  such  preliminary  cartilaginous  prefigure- 
mentb  It  must  not,  however,  be  supposed  that 
in  the  cartilage  bones  the  cartilage  is  converted 
into  bone ;  for  here,  as  in  the  cases  where  there  is 
no  cartiUffe  present,  the  true  bony  tissue  is 
laid  down  oy  the  agency  of  certain  cells  termed 
osteoblasts  in  the  connective  tissue  sheath 
(periosteum)  of  the  bone,  and  the  oartflage 
when  present^  after  undergoing  a  certain  amount 
of  calcification,  is  then  entirely  eaten  away  by 
certain  large  cells  called  osteoclasts.  In  the 
cartilaginous,  as  distinfuished  from  the  bony 
or  teleostean,  fishes,  the  replacement  of  the 
cartilage  by  true  bone  does  not  occur. 

Bone  is  deposited  in  concentric  lamins,  the 
majority  of  the  layers  encircling  the  channels 
called  Haversian  canals,  in  which  the  blood- 
vessels lie.  The  living  elements  in  bone,  the 
bone  cells,  lie  in  spaces  between  the  laminse, 
and  these  spaces  (lacunsB)  intercommimicate 
by  minute  canals,  in  which  lymph  flows  and 
maintains  their  nutrition. 

The  chemical  materials  present  are  organic 
and  inorganic.  The  or^nic  materials  are 
proteins  and  nudeln  denved  from  Uie  bone 
cellsy  a  small  quantity  of  an  elastin-like  sub- 
stance which  forms  a  lining  to  the  Haversian 
canals,  and  a  mucoid  or  glucoprotein ;   but  the 


principal  organic  material,  sometimes  misnamed 
bone  cartilage,  is  better  termed  ossein.  Ossein 
is  identical  with  the  collagen  of  connective  tissues, 
and  like  it  yields  gelatin  on  boiling  with  water. 
If ^  the  inorganic  salts  are  dissolved  out  by 
mineral  aci(u,  the  ossein  remains  as  an  elastic 
mass  which  preserves  the  original  shape  of  the 
bone. 

The  inorganic  constituents  remain  as  the 
so-called  bone  earth  after  the  bone  is  completely 
calcined ;  it  consists  chiefly  of  calcium  phosphate, 
but  also  contains  calcium  carbonate,  and  small 
amounts  of  magnesium,  chlorine,  and  fluorine. 
Gabriel  (ZeitscL  physioL  Chem.  18)  states 
that  potassium  and  sodium  also  occur.  Traces 
of  iron  come  from  the  blood  in  the  bone,  and  of 
sulphate  from  chondroitin-Bulphuricacid(Momer, 
ibid.  23). 

Investigators  differ  as  to  the  manner  in 
which  the  inorganic  substances  are  combined. 
Chlorine  and  fluorine  are  present  in  the  same 
form  as  in  apatite  (CaFl,-3Ca,P,0t),  and 
according  to  Gabriel,  the  remaining  mineral 
constituents  form  the  combination  3(Ga,P,0a) 
CaCO,.  He  gives  as  the  simplest  expression 
for  the  composition  of  the  ash  of  bones  and 
teeth  the  formula  Ca,(P04),-fCa,HP,0,,-f  H.O, 
m  which  2-3  p.a  of  the  lime  ia  replaced  by 
magnesia,  potash,  and  soda,  and  4-6  p.o.  of 
the  phosphoric  acid  by  carbon  dioxide,  cmorine, 
and  fluorine. 

Zalesky's  analyses  (Hoppe-Seyler's  Med. 
Chem.  Untersuch.  19)  show  how  closely  bone 
earth  agrees  in  composition  in  different  animals. 
The  figures  represent  parts  per  1000.  (See  Table. ) 
The  various  bones  of  the  skeleton  differ  a  good 
deal  in  the  proportion  of  water,  oiganic  solids, 
and  inoi^anic  solids  which  they  contain.  This 
depends  to  some  extent  on  the  admixture  of 
marrow,   blood-vessels,  and    other    formations 

2s 


026 


BONE. 


from  whioh  it  is  difficnli  to  freo  entirely  the 
osaeons  tissue  proper.    The  quantity  of  water 


• 

Man 

Ox 

Tor- 
toise 

Oninea- 
pig 

Calcium     phosidiAte 

Cb,(P04),     . 

888« 

8600 

850*8 

878*8 

Mngneshitii  phoaphate 
ligi(P04),    . 

10*4 

10-2 

18-6 

10*5 

Ca     combined  with 

CO..  Ft,  and  CI     . 
C0|  (pattly  loat  on 

76-S 

788 

68*2 

70*8 

calcining) 

57-8 

6t-0 

62-7 

— 

Clilorine  .        .        • 

1-8 

20 

— 

1*8 

Fluorine  . 

2-3 

80 

20 

"■ 

in  freeh  bones  thus  varies  from  14  to  44  p.c., 
and  of  fat  between  1  and  27  p.c.  The  quantity 
of  total  organic  substance  varies  from  30  to 
fi2  p.0.,  the  remainder  being  inorganic. 

The  marrow  is  from  the  chemical  point  of 
view  mainly  fat;  its  cells  yield  protein  and 
nudeoprotem. 

On  a  rough  average  it  may  be  said  that  two- 
thirds  of  the  solids  consist  of  inorganic  and  one- 
third  of  oiganic  compounds. 

With  r^;aid  to  the  minute  composition  of 
bones  at  difierent  ages,  we  have  no  very  accurate 
information.  Voit  found  in  dogs  and  J^rubacher 
in  children,  that  the  water  in  the  skeleton 
decreases  and  the  ash  increases  with  advance 
of  years.  Gra£Fenber^er*s  observations  on  rab- 
bits confirmed  this  view. 

A  great  many  experiments  have  been  made  to 
determine  the  influence  of  food — ^for  instance, 
rich  or  poor  in  lime  salts — on  the  composition 
of  bone,  but  the  results  have  been  doubtful  or 
contradictory.  The  attempts  to  substitute 
other  alkaline  earths  for  lime  have  also  eiven 
uncertain  results  {see  H.  Weiske,  Zeit.  f.  JBiol. 
31 ;  also  Hammarsten's  Physiol.  Chom.  translated 
by  Mandd). 

A  lan^e  number  of  data  have  also  been 
publishea  regarding  the  variations  in  chemical 
composition  m  different  diseases  of  bone.  Thus 
in  exostoses  the  inorganic  material  is  usually 
increased;  in  rickets  and  osteomalacia,  the 
proportion  of  water  and  ossein  to  bone  earth  is 
raised.  The  view  that  lactic  acid  is  responsible 
for  the  washing  out  of  lime  salts  from  bones 
in  rickets  is,  however,  discredited. 

The  somewhat  rare  condition  of  a  curious 

Srotein  (cidled  Bence-Jones  protein,  after  its 
iscoverer)  in  the  urine  is  almost  invariably 
associated  with  bone  disease  (osteomalacia,  or 
malignant  new  growths).  This  protein  in  many 
of  its  characters  resembles  a  proteose,  but  is 
probably  derived  from  the  mucoid  of  osseous 
tissue  (Rosenbloom,  J.  Biol.  Chem.  1910,  7, 
14;  WUliams,  Bio.  Chem.  J.  1910,  5,  225). 

On  heating  out  of  contact  with  air,  bone 
evolves  a  la^e  quantity  of  volatile  matter 
(v.  BozTB  oil)  which  contains  ammonia,  pyridine 
bases,  P3rrrol,  nitriles,  &c.  A  black  residue  is 
left,  consisting  of  the  bone  ash  in  association 
with  carbon,  which  is  called  animal  charcoal  {q.v,). 

The  industrial  uses  of  bone  are  very  numerous 
and  involve  a  large  import  trade ;  not  only  is 
the  bone  itself  made  into  many  utensils,  but 
the  materials  made  from  the  bone  (charcoal, 
bone  ash,  gelatin,  Ac.)  are  put  to  many  uses. 

Thus  animal  charcoal  or  bone  black  is  em- 
ployed in  many  chemical  operations,  in  sugar 
refining,  as  a  polish  for  silver  work,  &a 


Bone  meal  and  bone  ash  are  eztenmvely 
employed  as  manure,  and  in  the  preparatioii  of 
the  superphosphates  of  commerce.^ 

The  gelatin  in  an  impure  form  is  used  m  the 
preparation  of  paper,  silk,  furs,  &o.,  and  the 
purer  varieties  are  also  put  to  numerous  uses, 
for  instance,  as  a  clarifying  agent  in  the  prepara- 
tion of  wines,  beers,  liqueurs,  for  food  in  the 
preparation  of  soups,  jellies,  and  puddings,  in 
the  making  of  photographic  films,  and  in 
Bacteriology  for  the  preparation  of  cnltare 
media.  {See  Merck's  Waren-Lexikon,  arts. 
'Knochen,'  *  Knochenasche,'  *  Knochenkohle,' 
'  Knochenol ' ;  H.  Ost,  Lehrbuch  der  Chem. 
Technologic,  6th  ed.  1907,  *  Knochenmehl,' 
187,  *  Knochenleim,'  621 ;  Dammer,  Handbuch 
d.  chem.  Technologic,  1898,  6,  art  *  Knochen- 
verarbeitung,*  254.) 

The  mention  of  gelatin  as  food  suggests  a 
word  on  its  nutritive  value.  It  is  easily 
digestible  and  assimilable,  and  so  ia  much  em- 
ployed in  invalid  cookery  ;  nevertheless,  it  has 
k)ng  been  recognised  that  it  is  of  inferior 
nutritive  value.  If  aninuUs  receive  gelatin  as 
their  sole  nitrogenous  food,  they  waste  and  die 
more  rapidly  tJum  if  nitro^nous  food  is  entirelv 
withhela  from  them;  still,  when  mixed  witli 
other  proteins,  less  of  tHe  latter  is  sufficient  to 
maintain  life.  Recent  investigations  on  the 
chemistry  of  proteins  have  shown  that  gelatin 
is  destitute  of  the  tyrosine  and  tryptophane 
groups,  and  these  groups  appear  to  bo  of  spedal 
value  or  even  indispensable  for  tissue  repair; 
the  previoudv  puzdmg  behaviour  of  gelatm  in 
nutrition  is  thus  explicable.  W.  D.  H. 

BONE  ASH  V.  Bom  and  Febttussbs. 

BONE  BLACK  v,  Aktmal  chabcoal. 

BONE  EARTH.  The  calcined  residue  of 
bones,  consisting  chiefly  of  calcium  phosphate 
(v.  Bovb). 

BONE  FAT  is  the  fatty  matter  contained  in 
the  bones  of  animals,  and  is  practically  a  bv-pro- 
duct  in  the  process  of  working  up  bones,  whether 
it  be  for  the  manufacture  of  bone  char  or  for  the 
production  of  glue  and  gelatin.  In  either  of 
these  manufactures,  the  *  degreasin^ '  of  the 
bones  precedes  all  further  manipulations. 
Bones  from  head,  ribs,  shoulder  blades,  Slc^ 
contain  from  12  to  13  p.c.  of  fat,  whilst  the 
*  marrow'  bones,  t.e.  the  large  thigh  bone^ 
contain  as  much  as  18-20  p.o.  Formerly  booe 
fat  was  produced  by  boiling  the  broken  bones 
with  water  in  open  vessels,' and  allowing  the 
hot  liquor  to  stand,  so  that  the  fat  could  separai  < 
on  the  top  and  be  skimmed  off.  In  the  case  of 
fresh  bones,  the  recovered  bone  fat  had  a  white 
to  yellowish  colour,  a  faint  odour  and  taste, 
and  the  consistence  of  butter.  When  putrid 
bones  were  employed,  the  bone  fat  passed, 
according  to  age  and  state  of  decomposition 
of  the  organic  matter  in  the  bones,  through  all 
mdations  from  a  white  fat  to  a  dark  rancid 
fat  of  a  very  disagreeable  smell.  The  boiling- 
out  process  allows  only  about  one-half  of  the 
fat  to  be  recovered.  The  small  yield,  and  the 
nuisance  connected  with  the  preparation  of 
the  bone  fat  forced  the  manufacturers  to  treat 
the  bones  with  steam  under  pressure.  The 
broken  bones  were  placed  in  a  cage  fixed  inside 
an  autoclave,  and  were  heated  therein  with 
open  steam,  under  a  pressure,  of  2  to  3  atmo- 
spheres.   The  bone  fat  so  obtained  was  of  the 


BONE  OIL. 


627 


•ame  quftLi^  as  that  prepared  bjr  the  former 
prooees.  The  best  bone  fat  obtainable  in  the 
market  is  at  present  prepared  by  this  prooees, 
especially  in  the  laige  packing  houses  of  the 
United  States  and  &utn  Amerioa,  where  the 
bones  are  worked  up  in  the  fresh  stato.  They 
are  first  washed  in  *  bone-washing  machines.' 
These  are  cylinders  usually  10  feet  long  and 
3  feet  to  4  feet  in  diameter,  built  up  from  iron 
bars,  1  inch  apart,  fixed  into  two  cast-iron 
heads.  They  are  driven  by  chain  and  sprocket, 
and  rotate  slowly,  making  about  ten  revolutions 
per  minute.  Through  the  entire  length  of  the 
drum  there  is  a  hmged  door  made  of  bars, 
which  allows  the  filling  and  emptying  of  the 
cylinder.  The  machines  are  usually  set  at  an 
angle  to  facilitate  the  washing  and  emptying 
operations.  Some  manufacturers  even  resort 
to  steeping  the  bones  in  a  solution  of  sulphurous 
acid  in  o^er  to  obtain  a  whiter  fat  (as  also  a 
better  glue)  than  unbleached  bones  afford 
{see,  however.  Head  and  Lloyd,  J.  Soc.  Chem. 
Ind.  1912, 31, 317).  The  yield  of  bone  fat  in  the 
steaming-out  process  under  pressure  is  con- 
siderably higher  (by  about  50  p.o.)  than  in  the 
boiling-out  process  in  open  vessels,  so  that  from 
bones  contaming  12  p.c.  of  fat,  8  to  9  p.o.  can  be 
recovered. 

Bone  fats  of  this  quality  can  be  bleached, 
but  only  the  best  kinds  are  likely  to  yield  a 
ffood  product.  The  higher  the  percentage  of 
me  fatty  acids,  the  greater  is  the  difficulty  in 
bleaching.  In  fact,  products  containing  more 
than  60  p.o.  of  free  fatty  acids  could  mtherto 
not  be  bleached  successfully. 

The  highest  yield  of  bone  fat  is  obtained  by 
treating  the  bones  with  an  organic  solvent, 
whereby  the  animal  tissue  remains  unimpaired, 
so  that  the  whole  of  the  glue-yielding  organic 
substances  can  be  convert^  into  glue  after  the 
fat  has  been  removed.  The  solvent  used  in  bone- ' 
extracting  works  is  almost  exclusively  petroleum 
spirit  or  Scotch  shale  oil,  boiling  between  100^ 
and  130^.  Proposals  have  been  made  to  use 
carbon  tetrachloride  or  chloro-  compounds  of 
ethylene  and  ethane.  Experiments  with  carbon 
tetrachloride  have,  however,  been  abandoned  as 
unremunerative.  Extraction  with  *  benzine '  or 
shale  oil  takes  place  in  iron  digesters  under 
pressure  or  in  open  apparatus.  The  fat  obtained 
Dy  the  extracting  process  is  dark-brown,  and 
has  a  very  penetrating,  unpleasant  smell.  In 
addition  to  a  consideraole  amount  of  free  fatty 
acids,  it  contains  lime-soap,  calcium  lactate, 
calcium  butyrate,  and  hydrocarbons  from  the 
'  benzine '  which  cannot  be  fully  removed  even 
by  prolonged  steaming.  Hitherto,  this  kind  of 
fat  has  not  been  treated  successfully,  and  even 
when  some  immediate  improvement  was  ob- 
tained, the  colour  and  also  the  unpleasant  smell 
*  reverted  *  after  a  short  time.  A  patent  by  V  ol- 
land  (D.  R.  P.  222669)  claims,  however,  to  bleach 
extracted  bone  fat  by  means  of  barium  peroxide. 
In  von  Girsewald's  process  (Fr.  Pat.  430015, 
1911)  the  vapour  of  the  petroleum  spirit  or 
other  solvent  finally  remaining  in  the  pores  of 
the  material  is  condensed  by  the  introduction 
of  Tapour  of  the  same  solvent  at  a  pressure 
sufficient  to  produce  condensation  witliin  the 
extractor.  More  complete  extraction  of  the 
bones  is  thus  effected  and  the  re-admission  of  air 
is  prevented. 


The  process  patented  by  Schmidt  (Eng.  Pat. 
5368,  1913)  has  tor  its  object  the  rapid  separa- 
tion of  water  from  the  solvent.  This  is  effected 
by  condensing  the  vapours  from  the  extractor 
in  a  series  of  compartments  at  temperatures  just 
below  the  boiling-point  of  the  solvent  or  of  the 
respective  fractions,  and  conducting  the  con- 
densed liquids  to  a  common  separator,  where  the 
water  is  removed  prior  to  the  return  of  the  solvent 
to  the  extractor. 

A  method  of  removing  the  fat  from  bones 
without  the  use  of  a  solvent  is  claimed  in 
Powlinff's  process  (Eng.  Pat.  8397,  1912),  the 
materifu  Ming  agitated  in  a  steam  jacketed 
cylinder  until  the  fat  has  separated  and  the 
water  has  evaporated. 

The  bone  fat  obtained  by  the  boiling-out 
or  steamins-out  process  can  be  used  for  soap 
making ;  tne  fat  obtained  by  the  extracting 
process  is  utterly  unsuitable  for  that  purpose  in 
this  country,  on  account  of  its  rank  smell. 
On  the  continent,  however,  such  benzine- 
extracted  fat  is  used  up  for  soap  in  small  quanti- 
ties, especially  when  tne  price  of  fatty  materials 
is  high.  The  bulk  of  bone  fat  is,  however,  used 
in  candle  works,  where  it  is  hydrolysed  in  an 
autoclave  and  subsequently  subjected  to  the 
usual  acidif3ang  and  distilling  processes. 

Bone  fat  is  an  important  article  of  commerce. 
The  chemical  composition  of  bone  fat  lies 
midway  between  that  of  marrow  fat  and  tallow. 
On  account  of  the  larce  amount  of  fatty  acid 
contained  in  bone  fat,  wis  fat  must  be  examined 
by  special  methods,  for  which  the  reader  is 
referred  to  Lewkowitsch,  Chemical  Technology 
and  Analysis  of  Oils. 

Bone  oil,  fatty  bone  oil  (not  to  be  confounded 
with  DippePs  oil),  is  the  liquid  portion  of  bone 
fat  which  is  sometimes  prepared  in  the  same 
manner  as  tallow  oil  is  obtained  from  tallow. 
Bone  oil  is  used  as  a  lubricant,  and  in  the 
leather  industries  replaces  neat*s-foot  oil  in 
the  preparation  of  *  fat  liquor '  and  other 
emulsions.  If  such  bone  oil  is  free  from  fatty 
acids,  it  represents  one  of  the  best  lubricating 
oils  on  account  of  its  very  low  *  cold  test.' 

J.  L. 

BONE  HEAL  v.  Febtilisxbs. 

BONE  OIL.  Animal  oil ;  DippeTs  oil ;  Oil 
of  hartshorn  ;  Oleum  animale  empyreumaXieum  ; 
Oleum  comu  eervi;  Oleum  Dippelii.  {Knoeh- 
end,  Thierol,  Ger.)  The  product  obtained  by 
distiUing  bones  in  the  preparation  of  bone  black 
or  ammal  charcoal.  The  first  mention  of  an 
animal  oil  appears  to  be  in  the  writings  of 
0.  Gesner,  1552,  and  of  A.  Libavius  (Alchemia 
Lib.  IL,  Tract  IL),  1596,  whilst  J.  R.  Glauber 
(1604-1668)  also  describes  the  unpleasant - 
smelling  oil  derived  from  the  distillation  of 
animal  parts.  Apparently  the  first  consistent 
steps  in  an  examination  of  the  oil  were  made  by 
Johann  Dippel  in  1711,  and  afterwards  b^ 
O.  Unverdoroen  (1826),  who  isolated  from  it 
four  bases  which  he  described  as  odorin,  animin, 
olanin  and  ammolin.  The  investigations  of 
Anderson  (Trans.  Roy.  Soc.  Edin.  16,  123  ;  463  ; 
20,  247  ;  21,219)  were  the  first  in  which  the  pure 
pjrridine  bases  present  in  the  oil,  were  obtained. 

The  bones  are  first  boiled  in  a  large  quantity 
of  water,  which  removes  the  greater  part  of  the 
fatty  matters  ;  they  are  then  roughly  dried  and 
are  subjected  to  dry  distillation  in  iron  retorts. 


628 


BONE  OIL. 


similar  to  those  used  in  the  manufaxstiue  of  coal 
gas.  Bone  black  or  animal  charcoal  remains 
behind  and  bone  oil  distils.  The  products  of 
distillation  are  conducted  through  long  iron 
tubes,  which  act  as  condensers  and  le«^  into 
receivers,  where  the  crude  bone  oil  collects, 
together  with  water.  The  gases  are  then  passed 
into  a  separator  containing  sulphuric  acid  to 
retain  ammonia,  and  can  afterwards  be  used  for 
heating  purposes,  or,  if  passed  through  purifiers, 
for  illumination.  The  crude  oil  is  separated 
from  the  aqueous  distillate  and  is  subjected  to 
redistillation.  The  aqueous  liquid  consists  of  a 
sol  jtion  of. ammonium  sulphide,  ammonium  thio- 
cyanats  snd  cyanide,  ammonium  carbonate,  and 
small  quantities  of  very  volatile  organic  bases. 
This  is  treated  with  sulphuric  acid  and  afterwards 
distilled  with  slaked  lime.  The  distillate,  on 
treating  with  solid  potash,  yields  laige  quantities 
of  ammonia,  whilst  some  ouy  bases  separate  out, 
and  are  afterwards  worked  up  with  the  bases 
contained  in  the  crude  oil.  This  latter  is  a 
dark- brown,  nearly  black  liquid,  having  a  foetid, 
most  offensive  smell,  and  a  sp.er.  0*970. 

On  subjecting  it  to  redistillation  it  begins  to 
boil  at  80"*,  when  quantities  of  ammonia  come 
over  together  with  an  oil.  The  temperature 
rises  very  gradually  to  about  250**.  From 
180°  upward  large  quantities  of  ammonium 
cyanide  and  ammonium  carbonate  sublime  over, 
and  care  has  to  be  taken  to  prevent  the  con- 
denser being  stopped  up.  A  black  resinous 
tar  remains,  whicn  is  employed  in  making 
Brunswick  black. 

The  following  substances  have  been  isolated 
from  bone  oil  oy  fractional  distillation  com- 
bined with  treatment  with  acids  to  separate 
basic  from  non-basic  constituents: — 


Chief  congtituents 
Butyro-nitrile 
Valero-nitrile 
Hexo-nitrile 
Isohezo-nitrile 
Beco-nitrile 
Palmito-nitrile 
Stearo-nitrilo 
Pyrrole 

Methyl-pvrrole 
Dimethyl-pyrrole 

Hydrocarbons 


14 


Subsidiary  coruiituenU 
Methvlamine 
Ethylamine 
Aniline 
Pyridine 
Bdfethyl-pyridine 
Dimethyl-pyridine 
Quinoline 
Phenol 
Propionitrile 
Valeramide 
ToWene 
Ethyl- benzene 
Naphthalene 


CiiHj, 

(Weidel  and  Ciamician,  Ber.  13,  65). 

As  to  the  formation  of  the  various  compounds 
in  bone  oil,  the  nitriles  are  formed  by  the  action 
of  ammonia  on  the  fatty  acids,  pyrrole  and  the 
pyrroles  are  the  products  of  decomposition  of  the 
gelatinous  substances,  and  pyridine  and  its 
derivatives  are  condensation  products  of  acro- 
lein, from  the  dry  distillation  of  the  fats,  with 
ammonia,  methylamine,  &c. 

Pyrrole.  That  portion  of  the  non-basic  part 
of  bone  oil  boiling  at  08^-150°  contains  pyrrole 
and  its  homologues.  Ciamician  and  Dennstedt 
(Ber.  1886,  19,  173)  purify  the  crude  pyrrole  by 
heating  for  m^ny  hours  under  reflux  with  solid 
caustic  alkali,  until  the  solid  mass  becomes 
fused.  After  coolins,  the  unaltered  oil  is 
separated  from  the  solid  residue,  and  the  residue 
powdered  and  washed  with  absolute  ether. 
Water  is  added  and  the  mass  distilled  in  a 
current  of  steam  when  the  pyrrole  distils  over. 


The  fraction  140'*-lfi0*^  oonnste  of  a  mixton  of 
homopyrroles — i.e.  methylpyxroles.  That  aboTC 
160°  contains  dimetiiylpyirole.  To  ssputte 
the  a-  and  fi-  derivatives,  the  mixture  is 
converted  into  the  potassium  oomponnd  by 
fusion  with  potash,  and  heated  in  a  conent 
of  carbon  dioxide  to  200^  Two  isomeric  homo- 
pyrrole  carboxylic  acids  are  formed,  which  differ 
m  the  solubility  of  their  lead  salts^  a-Homo- 
pyrrole'carboxylic  acid  melts  at  169*5°,  and  its 
letA  salt  is  veiy  soluble  in  water,  differing  fran 
ike  i9-acid,  which  melts  at  142*1%  and  forms  s 
slightly  soluble  lead  salt.  The  adds  obUuned 
respectively  yield  on  distillation  with  lime  the 
corresponding  methyimToles.  a-Homopymfe 
boils  at  148°  under  760  mm.  pressure,  and 
/3-homopyrrole  at  143°  at  743  mm. 

The  constitution  of  pynclL?)  is  represented  as 
follows :—  CH=CHv 

the  positions  2  and  5  and  3  and  4  being  known 
as  the  a-  and  $-  positions  respectively.  It  boils 
at  130°-131°,  and  its  8p.gr.  is  0*9762  at  12°. 
Refractive  index  /u  ==1*6074  (Gladstone,  CheOL 

Soc.  Trans.  1884,  246).  It  is  slightly  soluble  in 
water,  readily  soluble  in  alcohol  and  ether.  It 
is  a  weak  base,  and  is  only  slowly  dissolved  by 
dilute  acids  in  the  cold,  it  also  possesses  faintly 
acidic  properties. 

By  the  action  of  iodine  on  potassium  pynole, 
tetriodopyrrole  is  formed,  which  crystaOtses  in 
yeUowisn-brown  prisms  and  decomposes  tX 
about  140°.  It  acts  like  iodoform  as  an  anti- 
septic, and  is  known  as  iodol.  It  has  the  advan- 
tage over  iodoform  of  being  free  from  smelL 

Pyrrole  has  been  synthesised  by  passing 
acetylene  and  ammonia  through  red-hot  tubes : 

2C,H,+NH,=C4H4NH-fH, ; 
also  by  distilling  the  ammonium  salts  of  mocie 
and  saccharic  acids.    Succinimide,  on  heating 
with  zinc-dust  containing  uno  hydrate,  abo 
yields  pyrrole 
CH,— CO  OH=CH 

I  \nH+2H,=  I  \NH-f  2H,0 

CH,— do  CH=CH 

Most  of  these  methods  eive  only  a  smaB 
yield  of  pyrrole,  but  Khotinsky  (1909)  obtained 
a  42  p.c.  yield  by  heating  ammonium  mucate 
with  an  excess  of  glycerol,  saturating  the  mixtme 
with  ammonia  at  270°  and  then  distilling  at 
320°-30°, 

Potassium  dissolves  in  pyrrole  with  the 
formation  of  potassium  pyrrole  C^H^NK,  a 
substance  insoluble  in  ether  and  decomposed  by 
water  into  pyrrole  and  potassium  hydroxide. 
This  substance  reacts  with  alkali  iodides  to  form 
substituted  pyrroles ;   e.g. : 

N-Methylpyrrole,  04H4N*CHa :  boils  at  1  IS" ; 
sp.gr.  0*9203. 

N.Ethylpyrrole  O^H^N-CtH^  :  boik  at  131° ; 
so  irr  0*9042 

N-Phenylpyrroie  C4H4N*C,H,,  obtained  by 
distilling  the  anilides  of  mncio  and  saccharic 
acids,  melts  at  62°.  The  homologues  of  pyrrole 
contained  in  bone  oil  are,  however,  all  substi- 
tuted in  the  group  G4H4. 

Pyrrole  homologues  may  be  prepared  by 
Paal's  method,  which  consists  in  the  condensa- 
tion of  7-diketone8  {e,g.  acetonyl-aoetone)  witb 
ammonia : 


BONE  OIL. 


629 


CH.COCH.CHj-COCH, 

CH CH       NH, 


cu,h^ 


CH-CH 

r     II 


X  .CCH,        CH,Cv  ^CCH, 

OH  HO  NH 

By  the  action  of  bcnzalchloride  on  pyrrole  in 
presence  of  sodium  a  phenylpyridine  is  obtained 
in  which  the  phenyl  is  in  the  meta-  position  to 
the  nitrogen  (Ciamician  and  Silber,  Ber.  20, 191). 

By  rraucinff  pyrrole  with  zinc  and  acetic  add 
A*  pyrroline  is  produced  (Ber.  1901»  3962). 
Electrolytic  reduction  to  the  same  substance 
may  be  effected  by  suspending  pyrrolo  in  dilute 
sulphuric  acid  in  the  cathode  cell  of  an  electro- 
lytic apparatus,  the  cathode  being  lead,  and 
passing  a  current  of  density  1  amp.  per  sq.  cm. 
Homofogues  may  be  similarly  reduced  (D.  R.  P. 
127086,  1902).  The  stronger  reduction  of 
pyrrole,  by  means  of  hydrlodic  acid  and  phos- 

EhoruB,  or  by  passing  pyrrole  vapour  mixed  with 
ydrogen,  over  reduced  nickel  at  180^,  converts 
it  into  pyrrolidine  (tetrahydro  pyrrole)  C4H,N. 

Nascent  hydrogen  converts  pyrrole  into 
pyrroline  CaH^NH,  a  liquid  boiling  at  91^  which 
dissolves  eaaily  in  water.  It  yields,  with  nitrous 
acid,  a  nitrosoamine  CaH^N'NO,  m.p.  37^, 
and  on  heating  with  methyl  iodide  gives  methyl- 
pyrroline  (Ber.  16,  1536). 

Pyrrole  is  readily  oxidised  to  maUimide 
C4H,0aN,  which  forms  faintly  yellow  crystals, 
melting  at  93°,  and  readily  yields  a  dibromide, 
melting  at  226°  under  the  influence  of  light  and 
bromine  water  (Atti.  B.  1904,  (v.)  L  489). 

The  action  of  formaldehyde  and  meihylene 
chloride  on  pyrrole  is  described  by  Pictet  and 
Bimet(Ber.  1907,  1166). 

By  the  action  of  chloroform  in  absolute  ether 
on  the  potassium  derivative  of  pyrrole,  )3-chloro- 
pyridine  is  obtained. 

Pjrrrole  derivatives  condense  with  aldehydes 
under  the  following  conditions:  (1)  When  the 
derivatives  contain  at  least  one  hydrogen  atom 
combined  with  a  carbon  atom  of  the  nucleus, 
either  in  the  a-  or  j3-  position ;  (2)  when  both 
a-  and  j3-  positions  are  occupied  by  subetituents, 
no  combination  occurs  even  if  the  iminic  hydro- 
gen is  present ;  (3)  pyrrole  derivatives  containing 
more  than  one  CH  group  in  the  ring  may  com- 
bine with  aldehydes  in  molecular  proportions  (Ber. 
1902, 1647).  On  the  constitution  of  uie  tripyrrole, 
obtained  by  passing  dry  hydrogen  chlonde  into 
a  benzene  solution  of  pyrrole,  see  Tschelincev, 
J.  Russ.  Phys.  Chem.  Soc.  1915,  47,  1224. 

IndoU  C,H4<^^>CH  is  obtained  by  dis- 

solviDg  pyrrole  in  10  p.c.  sulphuiio  acid,  allow- 
ing the  mixture  to  stand  1-2  houis,  and  then 
distilling  in  steam  after  adding  excess  of  sodium 
hydroxide.  Diethyl  indole  prepajed  by  this 
process  is  a  viacid  ill-smelling  oil,  boiling  at 
270°-310«  (D.  R.  P.  125489). 

Pyrrole  may  also  be  converted  into  indole 
by  dissolving  in  dilute  hydrochloric  acid, 
adding  slight  excess  of  ammonia,  filtering, 
extracting  the  filtrate  twice  with  ether,  and 
heating  tne  tripjrrroline  obtained  in  the  extract 
to  above  300°,  when  indole  and  pyrrole  result 
(Ber.  1894,  476). 

Indole  may  also  be  obtained  by  the  reduction 
of  o-oitrophenyl  acetaldehyde,  by  fusion  of  o-ni- 
trocinnamic  add  with  iron  and  caustic  potash 


NOjC^H*  CH :  CHC0,H+2KH0-f-4H 

=K,C0,+3H,0+C,H,N 

or  from  o-aminophenylacetamide  by  internal 
condensation  to  the  amino-indole  and  subsequent 
reduction  with  sodium  amalgam  (Pschorr). 

It  crystallises  in  colourless  laminse,  melts  at 
52°,  and  is  soluble  in  hot  water.  It  behaves  as  a 
feeble  base.  On  treatment  with  sodium  ethoxide 
and  chloroform  it  is  converted  into  quinoltne. 
The  indole  molecule  is  rather  difficult  to  oxidise, 
without  more  or  less  complete  decomposition, 
but  if  it  be  first  converted  mto  1 -benzoyl  indole 
then  on  oxidation  in  acetone  solution  by 
potassium  permanganate  it  yields  benzoyl 
anthranilio  acid  readily,  from  which  anthranilic 
add  is  easily  obtained  by  hydrolysis.  In  a 
similar  manner  halogen  substituted  indoles  can 
be  obtained  by  the  direct  action  of  halogen  on 
the  benzoyl  indole  in  carbon  bisulphide  scuution, 
followed  by  hydrolysis  of  the  benzoyl  group  with 
aqueous  ammonia  (Weissgerber,  Ber.  1913,  46, 
651).  When  large  quantities  of  indole  are 
distilled,  a  small  quantity  of  hi^h  boiling  residue 
is  left  behind,  this  is  a  trimenc  form  of  indole 
(Keller,  Ber.  1913,  46,  726).  Substituted  indoles 
may  be  prepa^red  by  the  action  of  heat  and  a 
catalyst  (zinc  chlonde  or  cuprous- chloride)  on 
the  hydrazones  of  aldehydes  and  ketones  e,g. 
methyl  ethyl  ketone  phenylhydrazone  at 
180°-230°  with  a  trace  of  cuprous  chloride  yields 
2'3-dimethyl  indole  (Arbuzor,  J.  Russ.  Phys. 
Chem.  Soc.  1913,  45,  70).  Primary  and 
secondary  amines  on  condensation  with 
mesoxalio  esters  also  yield  substituted  indole 
derivatives;  thus  from  aniline,  dioxindole-3- 
carboxylic  acid  is  obtained,  from  which  dioxin- 
dole  results  on  hydrolysis  of  the  carboxylic 
acid  ester  in  the  absence  of  air  (Guyot  and 
Martinet,  Compt.  rend.  1913,  156,  1625) 

(HO),CCOOR 

ROOC 
NH, 

(^^ C(OH)COOR 

NH 

Pyrrole  may  be  converted  into  tetramethtflene 
diamine  as  follows.  On  treatment  with  hy- 
droxylamine,  a  solid  compound,  probably  the 
dioxime  of  succinaldehyde,  is  formed,  and.  this, 
by  reduction  with  sodium  and  absolute  alcohol, 
yields  tetramethylene  diamine. 

Pyrrole  derivatives  of  the  constitution 
EtO,CC=CMe 


a 


u 


\ 


NC.H4N0, 


HC=CPh 
have  been  synthesised  from  the  three  nitro- 
anilines  by  the  action  of  ethylphenacyl  acetate 
(Ber.  1907,  1343). 

In  addition,  a  large  number  of  pyrrole 
derivatives  has  been  synthesised  by  Paal  and 
BraikofiF  (Ber.  1890,  1086,  and  also  Ber.  1886, 
558,  3156). 

The  physiological  action  of  03^:010  and  its 
derivatives  is  characterised  by  their  paralysing 
action  on  the  peripheral  nerves  connected  with 
the  mechanism  of  the  heart.  By  the  introduc- 
tion of  a  side  group,  such  as,  for  instance,  the 
inactive  pyridine  ring,  tbe  physiological  effect  is 


630 


BONE  OIL. 


greatly  intensified.  The  action  of  1 -methyl 
pyrrolidine  resembles  that  of  nicotine,  atropine, 
or  cocaine,  as  might  be  anticipated  from  their 
similaiity  of  constitution  (Ghem.  Zentr.  1902, 
ii.  390). 

Chloro-  and  Bromo-  Pyrroles.  Sulphuryl 
chloride  in  excess  acting  on  an  ethereal  solution 
of  pyrrole  at  0^  produces  peniachhroptfrrole  in 
nearly  theoretical  yield ;  b.p.  209''  or  142716  mm. 
If  two  molecules  only  of  sulphuryl  chloride  are 
used,  followed  by  •bromine  (2  mols.),  chloro- 
tnbromopyrrole  G4NHBr,Cl  is  obtained,  which 
separates  from  light  petroleum  in  large  prismatic 
masses  of  a  pink  colour. 

Sulphuryl  chloride  (3  mols.)  followed  bv 
bromine  (1  moL)  gives  dichlorodibromopyrrole 
GfHNClaBr,,  which  crystallises  in  laige  shining 
scales  decomposing  just  above  106°  (Gazz.  chim. 
ital.  1902,  313). 

GGliGGlv 

Trichhromondbromopyrrole        \  ^NH 

GBr:Ga/ 
may  be  obtained  by  the  action  of  sulphuryl 
chloride  and  bromine  on  ethereal  solution  of 
pyrrole  at  0°.  .It  crystallises  in  monoclinic 
prisms  with  yellowish-red  reflex,  turning  brown 
at  105°,  and  melting  and  decomposing  at  116° 
(Gazz.  chim.  ital.  1902,  313  ;   1904,  ii.  178). 

Monohalogen  derivatives  of  pjrrrole  may  be 
prepared  by  the  action  of  magnesium  methyl 
iodide  on  a  secondary  pyrrok,  followed  iy 
halogen  at  low  temperature  (Hess  and  Wissing, 
Ber.  1914,  47.  14163. 


Br 


-f  MgXBr 


u  -  uwx  -^  KM 

NMgX      NH  NH 

These  compounds  are  very  unstable,  and  de- 
compose even  on  keeping ;  thus,  bromo- 
pjrrrole  explodes  violently  even  when  kept  in  a 
sealed  tube,  decomposing  into  carbon  and 
ammonium  bromide. 

The  dimethylpyrrole  contained  in  the  fraction 
of  bone  oil  boiling  above  160°  has  been  obtained 
synthetically  as  Follows :  By  the  action  of  am- 
monia on  diacetosuccinic  ether,  the  ether  of 
dimethylpyrrole  dicarboxylic  acid  is  obtained. 
This,  on  saponification,  yields  the  acid,  and,  on 
heating,  carbon  dioxide  i^  split  off,  leaving  di- 
methylpyrrole.    It  has  the  composition 

GH=CCH, 

Nnh 

GH=CCH, 
and  is  an  almost  colourless  oil  boiling  at  166°. 
It  is  very  volatile  with  steam,  colours  a  pine 
splint  an  intense  red,  and  yields  on  boiling  with 
acids  a  pyrrole-red  similar  to  other  pyrrole 
homologues. 

PyrroleearboxyUe  acids  G4(NH)H,G0,H.  The 
a-acid  ifi  obtained  from  a-homopyrrole  by  fusion 
with  potash  or  by  the  action  of  tetrachloride 
of  carbon  and  alcoholic  potash  on  pyrrole.  It 
melts  at  191°,  and  differs  from  the  fi-  acid  in 
forming  a  soluble  lead  salt.  On  heating  with 
acetic  anhydride,  the  substance  py  roc  oil 

C4H,=N— CO 


60 N=C4H, 


is  formed,  which  is  a  product  obtained  by  dis- 
tilling gelatine  (Ber.  17,  103). 

/S-j^rroleearboiyUe  aeld  is  formed  by  fusing 


^-methylpyrrole  with  potash.  It  crystallises  in 
fine  needles,  melting  at  162°,  and  forms  an  in- 
soluble lead  salt. 

N-Aoetylpyrrole  G.H«NG,H,0,  obtained  by 
the  action  of  acetyl  chloride  on  potaesiom 
pyrrole,  is  an  oil  boiung  at  178°.  It  is  decom- 
posed by  alkalis  into  pyrrole  and  acetic  add 
(Ber.  16,  2362). 

G-Acetylpytrole  G4H,(C,H.0)(NH)  is  formed, 
together  with  the  foregoing,  by  acting  on  pyrrole 
with  acetic  anhydri(&.  It  melts  at  90"^  and 
boils  at  220°,  but  is  not  decomposed  by  alkalis. 

A  di-indole  has  been  obtained  from  di-(ortho- 
nitrophenyl-bromo)  ethylene  by  redaction  with 
stannous  chloride  to  the  corresponding  di-amino 
.compound,  followed  bv  elimination  of  hydro- 
bromic  acid,  first  by  boiling  for  a  short  time  with 
alcoholic  picric  acid  and  subsequently  with 
alcoholic  potash  (Ruggli,  Ber.  1917,  60,  883). 


0 


GBr  NO, 


^NO, 


GBr 


-0 


_.^  GBr  NH,. 


NH 


Pyridine  G^HgN  is  contained  in  that  fraction 
of  the  basic  oils  of  bone  oil  which  boils  below 
120°,  but  is  also  found  in  smaller  quantities  in 
the  higher  fractions.  It  can  be  separated  in 
these  by  means  of  its  picrate 

G,H5N,C,H,(N0,),0H 

which  melts  at  162°.  It  is  not  easily  acted  on 
by  oxidising  agents,  and  can  be  separated  by 
this  means  from  the  other  components  of  the 
fraction. 

It  is  formed  from  all  pyridinecarboxylic 
acids  by  distilling  with  lime. 

The  following  are  some  of  the  synthetic 
methods  for  preparing  pyridine  and  its  homo- 
logues : — 

1.  Hvdrocyanic  acid  and  acetvlene  when 
passed  tnrough  a  red-hot  tube  yield  pyridine 

2G,H,-fHGN=G4H.N 

(Ramsay,  Ber.  10,  736). 

2.  Isoamyl  nitrate  when  heated  with  phos- 
phoric anhyaride  yields  pyridine 

G4HuONO,+3P,0,=G,H;,N+6HPO, 

(Ghapman  and  Smith,  Ann.  Suppl.  6,  329). 

3.  Acrolein  ammonia,  on  heating,  gives  off 
water  yielding  methylpyridine 

G.H,NO = G5H^(GH,)N + H,0 

4.  The  same  compound  is  formed  by  heating 
allyl  tribromide  with  alcoholic  ammonia  at  2d0' 

2G,H4Br,4-NH,=G,H4(GH,)N-f6HBr 

6.  Glycerol  and  acetamide,  on  heating  with 
phosphorus  pentoxide,  yield  methylpyridine 
(Ber.  16.  628). 

6.  Potassium  pyrrole,  on  heating  with  chloro- 
form, yields  chloropyridine. 

7.  Ethyl  aoetoaoetate,  heated  with  aldehyde 
ammonia,  gives  dihydrocoUidine  dioarboj^lio 
ester 


BONE  OIL. 


631 


=C,H,N(CH,),(C0,Cja,),+3H,0 
(Ber.  17,  1521). 

8.  Guareschi  has  obtained  compounds  of  the 
pyiidone  type  by  condensing  alkyi  aceto-acetio 
esters  with  cyanacetic  esters  and  ammonia 


H,CCN 


CCN 


CH,C=: 
BCH 
CO— NH-CO 


CH.CO 

BCH 

COOB     BOOC 
H,NH 

9.  Buhemann  has  also  obtained  the  pyiidone 
type  by  the  condensation  of  alkyl  dicarboxy- 
glataconic  esters  with  ammonia 
RCCl,+3CHNa<C00B'), 

=CH,(C00R'),+3Naa 

+(B'OOC),C :  CBCH(COOB'), 
(B'OOC),C :  CB'CH(COOR')|-fNH, 

=B'OOCC=CR— CH-COOB' 

C0-NH-C0  +  2B'0H 

10.  Cinnamenylidine  acetozime  on  distilla- 
tion is  converted  in  a-phenyl-a'-methyl  pyridine 

CH— CH=CH 
CH^CH  HON=CCH, 


H,0  + 


CcHjC- 


CH— CH=CH 

II 


-N=C 


•CH, 


11.  Pyridine  bases  are  obtained  by  the  con- 
densation of  ketones  with  acid  amides  (Pictet  and 
Stehelin,  Compt.  rend.  1916,  162,  867) ;  thus 
by  heating  acetone  (2  mols.)  with  acetamide 
a  mol.)  at  250'',  2.4.6-trimethyl  pyridine  is 
formed,  whilst  triphenyl  pyridine  results  similarly 
from  acetophenone  and  benzamide. 

By  heating  a  mixture  of  glycerol  and 
ammonium  phosphate,  a  mixture  of  a  lai^e 
number  of  pyridine  bases  is  formed.  j3-methvl, 
iS-ethyl,  probably  ^-propyl,  pyridine,  besides 
pyridfine  itself  and  homofogues  of  the  diazine 
C4H4N,,  have  been  recognised  (Stoehr.  J.  pr. 
Chem.  1892,  20). 

Pyridine  is  a  liquid  with  a  pungent  smell, 
nuscible  with  water ;  sp.gr.  0*9855  at  15°,  and 
0*9944  at  4"* ;  and  boils  at  1 15*27760  mm.  It 
forms  a  hydrochloride  CgH^NyHCl,  and  a  platini- 
chloride  (C,H«NHCl)sPtCl4.  Sodium  amalgam 
yields  piperidine,  i.e.  hexahydropyridinc, 
which  Lb  reconverted  into  pyridine  on  oxidation. 
It  forms  an  ammonium  iodide  with  alkyl  iodides, 
and  with  chloracetio    acid  a  pyridine- betaine 

C,H5N<:^Q^^0.    By  the  action  of  sodium  on 

pyridine  a  di pyridine  CiqHjoN,  is  obtained, an 
oU  boiling  at  280''>281''/744  mm.,  which  on  oxi- 
dation with  permanganate  yields  Monicotinic 
acid.  Together  wiUi  dipyridine,  a  body  ^-di- 
pyridyl  is  formed  NCsH^'C^HiN,  which  melts 
at  1 14''  and  distils  at  304^.  It  also  yields  Mouico- 
tinio  acid  on  oxidation,  and  on  reduction  with 
tin  and  hydrochloric  acid  forms  t«oniootine, 
which  melts  at  78''  (Ber.  16,  423). 

Sodium  reacts  with  pyridine  at  ordinary 
temperature  (best  in  an  atmosphere  of  nitroeen) 
to  form  dipyridine  sodium  (C(H.N),Na,  which 
on  heating  to  130^^  is  transformed  into  pyridine 
sodium  CsH,N*Na  (B.  Emmert,  Ber.  1914,  47, 
2598 ;    1916,  40,  1060). 


The  isomeric  m-dipyridvl  is  obtained  from 
m-dipyridyldicarboxylic  acid  (by  oxidising  phen- 
anthroline).  It  boils  at  293^*,  and  yieloB  on 
reduction  with  tin  and  hydrochloric  acid 
nicdidine  C^^H.^N,,  which  boils  at  228''  (Ber. 
16,  2521). 

Piperidine  between  180**  and  250*'  is  converted 
into  pyridine  in  presence  of  nickel;  pyridine, 
when  passed  together  with  hydrogen  over 
reduced  nickel  at  160°-180'',  yields  amylamine, 
not  piperidine,  and  this  in  poor  yield.  At  higher 
temperatures  ammonia,  pentane  and  lower 
hydrocarbons  are  obtained  (Sabatier  and  Mailhe, 
Compt.  rend.  1907,  784). 

Pyridine  may  advantageously  be  employed 
as  a  haloffen  carrier  in  halogenation  of  aromatic 
compounds  (Cross  and  Cohen«  Chem.  Soc.  Proo. 
1908,  15). 

The  compound  of  pyridine  with  methyl 
iodide,  when  added  to  a  solution  of  the  neces« 
sary  amount  of  iodine  in  alcohol,  is  converted 
into  pyridine  methylpentiodide  C,H,N(MeI)Ij, 
melting  at  47*5''.  Various  other  periodidcs 
are  described  by  Prescott  and  Trowbridge 
(J.  Amer.  Chem.  Soc.  1895,  859). 

Acetyl  and  benzoyl  chlorides  if  quite  pure 
do  not  react  with  pyridine  in  the  presence  of 
anhydrous  aluminium  chloride,  but  if  a  trace 
of  thionyl  chloride  beintroduoed,  then  the  normal 
ketone  production  takes  place  (Wolffenstein  and 
Hartwich,  Ber.  1915,  48,  2043). 

Double  compounds  with  zinc  bromide, 
nickel  bromide,  copper  bromide,  and  silver 
iodide,  are  formed,  out  are  rather  unstable 
(Compt.  rend.  1891,  622). 

Tne  physiological  action  of  pyridine  is  similar 
to  that  of  piperidine,  but  more  energetic.  Both 
produce  paralysis  of  the  motor  nerves,  by  their 
effect  on  the  motor  centres.  There  are  also 
destructive  changes  in  the  blood  corpuscles,  and 
paralysis  of  the  heart,  especially  m  pyridine 
poisoning  (Chem.  Soc.  Abstr.  1891,  603). 
It  iB  excreted  as  methylpyridylammonium 
hydroxide  (Chem.  Soc.  Abstr.  1893,  ii.  544). 

The  double  compound  of  pyridine  with  silver 
nitrate  AgN0,*2CfH(N  has  been  recommended 
by  Witt  as  a  ripening  agent  for  photographic 
emulsions  (J.  Soc.  Chem.  Ind.  1904,  235). 
Liippe-Cramer,  however,  denies  that  it  has 
any  advantages  over  the  ordinary  ammonia 
rijlening  {ibid.  1906,  197). 

Sulphurous  acid  esters  of  pyridine,  which 
may  be  obtained  by  heating  under  a  reflux 
condenser  with  excess  of  a  bisulphite  solution, 
are  useful  in  the  preparation  of  dyestuffs,  and 
are  also  used  as  medicaments  (D.  R.  P.  208638). 

A  pyridine-2.3-thiophen  has  been  obtained 
in  small  quantity  by  the  application  of  the 
Skraup  reaction  to  2-aminothiophen,  using 
2-uitrothiophen  as  the  oxidising  agent 

.  fV,i 

N      S 
(Steinkopf  and  Lutzendorfif,  Annalen,  1914,  403, 
45). 

On  heating  pyridine  with  concentrated  sul- 
phuric acid  to  300°,  iS-pyridiue-sulphonic  acid  is 
obtained.  The  sodium  salt  of  this  acid,  distilled 
with  potassium  cyanide,  yields  js-pyridyl 
cyanide,  which  on  hydrolysis  forms  nicotinio 
acid. 


63^ 


BONE  OIL. 


Sulphonation  of  the  jpyridine  nucleiw  can  be 
carried  out  more  readily  in  the  presence  of 
vanadyl  sulphate. 

Pyridine  may  be  directly  nitrated  by  heating 
with  a  mixture  of  fuming  nitrio  and  fuming 
sulphuric  acids.  Pyridine  nitrates  more  readily 
if  an  amino  group  is  present,  e.g.  2-amino- 
pyridine  nitrates  nearly  as  readil>[  as  aniline. 
The  nitro  pyridines  resemble  the  nitro-anilines, 
are  yellow  in  colour  and  feebly  basic. 

Pyridine  may  be  estimated  in  aqueous 
solution  by  heating  with  excess  of  gold  chloride 
and  dilute  HCl,  evaporating  to  dryness  and 
heating  the  ppt.  after  repeated  washing  with 

Surety  ether.    The  ppt.  has  the  composition 
,H,N-HClAuCl,  (Compt.  rend.  1903,  324). 
Pyridine  can  be  represented  as  a  benzene 
ring  m  which  one  CH  group  is  replaced  by  nitro- 
gen according  to  the  following  scheme : — 


4 
,0 


\ 


C3 


/ 
6C 

!I 
6C         C2 

1 


or 


:a 


The  positions  2,  6,  and  3,  6  are  known  as 
ortho-  and  meta-,  and  4  as  the  para-  position. 
Hence  three  mono-  derivatives  of  pyridine  are 
possible.  The  position  of  the  substituting  groups 
m  these  isomerides  has  been  proved  by  means 
of  the  phenylpyridinets  obtained  from  the  naph- 
thaquinolines  (Monatsh.  4,  437  ;  Ber.  17,  1518). 

Hydroxy-  Dkeivativks  of  Pyeidinb. 

The  three  possible  hydroxypyridines  are 
known: — 

a-Hydrozypyridine,  a-pyrldone,  by  distilling 
the  silver  salt  of  hydroxyquinolinic  acid ;  melts 
at  107°,  and  i^i  coloured  red  by  ferric  chloride. 

/S-Hydroxypyridine  is  formed  from  the  /S-sul- 
phonic  acid  bv  fusing  with  potash.  It  melts  at 
123°,  and  is  also  coloured  red  by  ferric  chlorida 

Y-Hydroxypyridine  or  7-pyridone  (which  is 
probably  not  a  hydroxyl-  but  a  carbonyl-  com- 
pound) is  obtained  from  hydroxypicolmic  acid 
with  evolution  of  CO^.  It  melts  at  148°  or  at 
62°  in  the  hydrated  form,  and  is  coloured  yellow 
by  ferric  chloride  (Ber.  17,  Ref.  169). 

Amiko-  Pyridines. 

Of  the  three  possible  aminopyridines,  two 
have  been  definitefy  isolated. 

1. — Aminopyridine  is  formed  by  the  distilla- 
tion of  2-aminopyridine-5-carboxylic  acid.  It 
melts  at  66°  and  boils  at  204^.  It  is  not 
diazotisable,  but  on  treatment  with  concen- 
trated hydrochloric  acid  and  nitrous  acid  yields 
2-chloropyridine.  « 

2. — Aminopyridine  ia  formed  by  the  action  of 
sodium  hypobromite  on  the  amide  of  nicotinic 
acid,  or  bv  the  action  of  sodamide  on  pyridine 
below  120  ,  and  decomposition  of  the  resultant 
product  with  water;  the  further  action  of 
sodamide  vields  2'6-di-aminopyridine,  which 
couples  with  diazo-compounds  (Tschitschibabin, 
J.  Kuss.  Phys.  Chem.  Soc.  1914,  46,  1216). 
It  melts  at  62°  and  boils  at  250°-252°.  It  is  a 
diazotisable  base. 


Pyridine  Monocarboxylic  Acids 
C,NH4(C0^). 

a-Pyridineearboxylie  add  (2-  or  ortho-), 
picolinic  acid  was  first  obtained  by  oxidising 
a-picoline.  It  is  easily  soluble  in  water,  crystal- 
lises in  white  needles,  melts  at  137°,  and  sab- 
limes.  By  the  action  of  sodium  amalgam, 
ammonia  is  given  off  with  the  formation  of  an 
acid  GgHgOt  (oxysorbinic  acid). 

/3-I^dIneearDOxylle  add  (3-  or  meta-),  called 
nicotinic  acid  from  the  fact  of  being  first  obtained 
by  oxidising  nicotine,  is  also  obtained  from 
/9-methyl-  or  ethyl-pyridine,  from  ^-pyrid^ 
cyanide,  and  from  three  dicarboxyUc  acidfl 
of  pyridine  (quinolinic  acid,  cinchomeronic 
acid,  and  Mocinchomeronic  acid),  which  on 
heating  give  off  carbon  dioxide.  It  crystallises 
in  needles  and  melts  at  232°.  It  is  readily 
soluble  in  hot  water  and  in  alcohol,  bat  is 
insoluble  in  ether. 

7-PyridlQeearbo]^Iie  add  (4-  or  pai&-),  im- 
nicotinic  acid  ia  obtained  from  cinchomeronic  add 
and  2 : 4-pyridinedicarboxylic  acid  on  heating, 
and  also  By  the  oxidation  of  all  7-Bub0titated 
pyridines.  It  melts  at  299*5°  with  sublimatioa 
or  at  316°  in  a  dosed  tube,  and  crystallisee  from 
hot  water  in  fine  needles. 

Hydroxypyridinb-monocarroxylio  AOID8. 

Several  of  these  CMsids  have  been  prepared 
either  synthetically,  e.g.  by  heating  Komanic 
acid  CeHfOf  with  ammonia,  or  from  the  dicar- 
boxyUc acids  by  splitting  off  1  mol.  of  carbon 
dioxide  (Ber.  17,  689). 

Komenaminle  aeid  C,NH.(0H),G00H,2H,O 
ia  obtained  by  boiling  komenic  acid  C^H^O^ 
with  ammonia.  It  decomposes  at  270  into 
carbon  dioxide  and  dihydroxypyridine. 

PYRIDIKB-DIOARROXYLIC  AOIDS  C,NH,(COiH)t. 

The  acids  of  this  type  may  be  obtained  as 
follows : — 

1.  By  the  oxidation  of  disubstituted  pyri- 
dines, containing  aliphatic  side  chains;  or  of 
monosubstituted  monocarboxylic  adds. 

2.  By  heatingk  the  tricarboxylic  acids. 

3.  By  the  oxidation  of  quinoline  and  its 
homologues. 

4.  By  the  oxidation  of  various  alkalddB 
(cinchonine,  cinchonidine,  &c.). 

Quinolinic  add  {afi-  or  2:3-)  is  formed  by 
oxidising  quinoline.  It  decomposes  and  softeDs 
at  190°-196°,  solidifies  at  200°,  and  mdta  affain 
at  231°.  It  decomposes  on  heating  into  carboQ 
dioxide  and  nicotimc  acid. 

Cinehomeronlo  add  (jSy-  or  3  : 4- )  is  formed  by 
the  oxidation  of  the  quinine  alkaloids  with  nitric 
add,  or  from  ^y-methylpyridinccarboxylic  add 
on  oxidation  with  permanganate^  It  mdte  at 
269°,  decomposing  into  carbon  dioxide,  wo- 
nicotinic  acia,  ana  some  nicotinic  acid. 

Lutidinie  aeid  {ay-  or  2  : 4-)  is  obtained,  to- 
gether with  some  Mocinchomeronio  acid,  by 
oxidising  lutidine.  It  mdts  at  239^-240^ 
(Voigt,  Annalen,  228,  64),  236°  (Ladenburg. 
Annalen,  247,  27),  decomposing  into  carbon 
dioxide  and  idonicotinic  add. 

/wdnehomeronie  add  {fia'-)  mdts  at  236^, 
decomposing  into  carbon  dioxide  and  nicotinic 
add  (Werdd  and  Herzig,  Wiener  Akad.  B.  i870» 
826). 


BONE   OIL, 


633 


Dlearboxylie  aold  {fifi'-)  or  Dlniootinic  aeid- 
By  heatipg  to  150^  «-pyiidine  tetracarboxylic 
acid  obtained  by  ozidisinff'the  lutidincarboxvlic 
acid,  prepared  by  the  coxufensation  of  »wbutalde- 
hyde  ethylacetoaoetate  and  ammonia.  The 
acid  does  not  melt  at  285®  (Hantzach  and  Weiss, 
Ber.  1886,  19,  284). 

Dlearboxylie  aeld  (aa'-)  or  Dlpieolinle  aeld. 
Obtained  by  oxidising  2  :  6-dimethylpyridine. 
It  melts  at  243*"  (Epstein,  Annalen,  231,  32), 
decomposing  into  caroon  dioxide  and  pyridine. 

Hydbozypybidinb-dicabboxylio  Acids 
C»NH,(OH)(CO,H),. 

Hydroxyqnlnolliiie  add  [OH :  (CO,H),= 
(a' :  a :  jS)].  By  fusing  quinolinic  acid  with 
potash.  It  blackens  without  melting  at  254° 
(Ber.  16,  2158).  Heated  with  water  to  IGS"*  it 
decomposes  into  carbon  dioxide  and  hydroxy- 
pyridinecarboxyUo  acid.  Its  silver  salt  on 
seating  yields  a-hydroxypyndine  (Ber.  17,  500). 

Ammoiiloelielldonle  aeid  is  obtained  by  heat- 
ing chelidonic  acid  with  ammonia. 

Pybioihb-tbicabboxylic  Acids  CsNH,(COsH)g. 

(ijSY-Triearbozylle  aeid,  Carboelnohomeronie 
add,  is  formed  by  completely  oxidising  the 
quinine  alkaloids,  also  from  7-methylquinoline 
and  from  y-quinolinecarboxylio  acid.  It  loses 
HHfi  (of  crystallisation)  at  115^-120°,  and 
melts,  if  quickly  heated,  at  250°  (Annalen, 
204,  308). 

a^)Sr-TriearboxyUe  add,  Carbodlnleotinie 
add,  is  obtained  from  j3-quinolinecarboxylic 
acid. 

The  six  tricarboxylic  acids  theoretically 
possible  are  known  and  characterised. 

Pybidinb  tbtracabboxyuo  Acids 
C5NH(00,H)4. 

o^'iS'-TetraearboxyUe  aeid.  By  oxidising 
the  lutidinedicarboxvlic  acid  formed  by  the 
condensation  of  Mobutylaldehyde  with  ethyl 
acetoacetate  and  ammonia  (Hantzsch  and  Weiss, 
Ber.  19,  284). 

The  acid  obtained  by  oxidising  coUidine- 
monocarboxylic  acid  crystallises  with  2  mole- 
cules of  water.  It  does  not  possess  basic  pro- 
perties. Eneigetic  oxidation  converts  it  mto 
oxalic  acid. 

Pyridine-pentaearboxylle  add  CtN(C0,H)s 
from  trimethylpyridine-dicarboxylic  acid.  Ciys- 
taUises  from  water  with  SH^O.  Decomposes 
without  melting  about  200°. 

Haloobn  Dbbivativbs  of  Pybidinb. 

a-Chlarapyridine  results  from  the  action  of 
PCU  on  a-hydroxypyridine ;  is  an  oil  boiling  at 
166^/714  mm.  (Ber.  1891,  3150). 

P-Chloropyridine.  By  the  action  of  chloro- 
form or  carbon  tetrachloride  on  potassium 
pyrrole  (Ber.  14,  1153)  is  an  oil;  b.p.  148°/743 
mm. 

Dichloro-  and  trichloro-pyridine  are  known. 

A  dibromopyridine  {^6^)  has  been  obtained 
by  acting  on  collidine-aicarboxylic  acid  with 
bromine  and  afterwards  removing  the  carboxyl- 
groups  (Pfei£Fer,  Ber.  20,  1349).  It  is  identical 
with  that  obtained  by  acting  on  pyridine  with 
bromine  (Hofmann,  Ber.  12,  988). 

a-Picoline  is  transformed  by  acetic  anhydride 


into  pkolide  OitHi^O^N,  which  on  heatins  with 
hydrochloric  acid  yields  pyrindoU  CsHfN,  an 
isomeride  of  indole. 


C=CH 


>CH 


^/N-CH' 
(SoholtK  and  Fraude,  Ber.  1913,  46,  1069). 

Homolooubs  of  Pybidinb. 

?\eoUn»{a'meihylpyridine)C^Ht{CU^),  This 
base  is  sepiarated  from  that  portion  of  bone 
oil  which  boils  between  130°  and  145°.  On 
subjecting  this  to  redistillation,  the  greater 
part  of  tne  oil  comes  over  between  133°  and 
139°.  It  is  not  possible  to  effect  a  separation 
of  the  bases  by  means  of  fractional  distil- 
lation, but  a  difference  in  the  solubility  of  the 
platinum  salts  of  the  two  bases  furnishes  a 
means  of  separating  them.  According  to 
Ladeabuig  (Ber.  1885,  47),  commercial  picoline 
consists  of  three  bases :  a-methvlpyridine,  a 
little  d-methylpyridine,  and  probaDly  aa'-di- 
methylpyridine.  The  same  observer  (Ber. 
1885,  51)  has  also  noticed  the  presence  of 
pyridine  in  this  fraction.  It  can  be  separated  by 
means  of  its  picrate,  which  melts  at  162°. 

Picoline  boils  at  128;^<'/760  nun.;  is  an 
optically  inactive  oil,  and  on  oxidation  yields 
picolinic  acid  (v.  supra). 

/3-Metliylpyridine  may  be  synthetically  pre- 
pared by  heatinff  acetamide  with  glycerol  and 
phosphoric  anhydride.  It  boils  at  143*5°,  and  on 
oxidation  yields  nicotinic  acid.  It  also  differs 
from  the  a-derivative  in  being  slightly  Isevo- 
rotatoi^.  Landolt  shows  tlus  effect  to  be  due  to 
errors  in  manipulation  (Ber.  1886,  157). 

7-Metliylpyridine  does  not  appear  to  be 
contained  in  bone  oiL  It  has  roen  obtained 
synthetically  by  the  action  of  heat  on  acrolein- 
ammonia,  and  also  from  allyl  tribromide ;  b.p. 
1431°/760  mm. 

PiCOLINB  MONOCABBOXYLIO  AcIDS 

C,NH,(CH,)C0,H. 

PicolineearlMxylie  aeid  {pyridine-a-methyl-y- 
carboxylic  acid)  is  formed  from  uvitonio  acid, 
the  product  of  condensation  of  pyruvic  acid 
and  ammonia.  It  sublimes  without  melting, 
and  yields  on  oxidation  a :  7-pyridinedicar- 
boxyhc  acid. 

S^-Methyipyridlne  earboxylie  add 
(CH,  :  C0,H^7  :  j9)    U    obtained    by    heating 
methylqoinolinic  acid  to  180°-185'.    It  melts 
at  212°  (Ann.  Chim.  Phys.  [5]  27,  493),  and 
yields  on  oxidation  cinchomeronio  acid. 

,  Six  of  the  ten  possible  picoline  monocar- 
boxylic acids  are  known  and  charaoterised. 

PlCOLUfB-DIGABBOXYUC  AOIDS 

C,NH,(CH,)(CO,H),. 

HethylqulnoUnle  aeid  ((COaH), :  GH,»a37). 
By  oxidising  7-methylquinoline  with  perman- 
ganate. It  melts  at  186f,  giving  carbon  dioxide 
and  7-methyl-i3-pyridine-carboinrlio  acid. 

UTitonie  aeid  r(GO,H), :  GH,=a7a']  is  the 
condensation  product  obtained  from  pyruvic 
acid  and  alcoholic  ammonia.  It  melts  at  274*, 
splitting  up  into  carbon  dioxide  and  picoline- 
oarbozyllo  acid. 

Pieoliiit-dlearboiylie  aeid,  from  aldehydine. 


634 


BONE   OIL. 


the  co&deDfiation  product  of  ethylidine  chloride  I 
and    aldehyde    ammonia.    It   sablimes    easily 
without  melting. 

Three  other  isomerides  are  known. 

A  picoline-tetraoarbozylio  acid  is  also 
obtainable  from  the  dicarbozylio  acid  of  oollidine 
by  oxidation  of  the  methyl-  groups  with  perman- 
ganate. Lutidine-tricarbozylio  acid  is  formed 
as  an  intermediate  product. 

Lutidine  (dimeihylpyridine).  The  bases  hav- 
ing this  constitution  are  mainly  contained 
in  that  portion  of  the  basic  oil  boiling 
between  160M70*.  After  redistilling,  it  is 
separated  into  the  two  fractions  160*-160^ 
and  160*-170^  The  position  of  the  methyl 
groups  in  these  two  fractions  is  determined 
By  means  of  the  oxidation  products  formed. 
The  first  fraction  yields  on  oxidation  wocin- 
chomeronic  acid,  which  melts  at  236*.  On 
heating*  carbon  dioxide  is  split  off  and  nicotinic 
acid  is  formed.  From  this  is  inferred  that  the 
position  of  the  two  methyl  groups  is  a' 6.  The 
higher  fraction  yields  lutidinic  acid  on  oxidation, 
and  this,  on  heating,  gives  Monicotinio  acid,  from 
which  it  follows  that  the  methyl-  groups  have  the 
positions  ay.  All  the  acids  give  pyridine  on 
distillation  with  lime.  According  to  the  re- 
searches of  Ladenbure  and  Roth  (Ber.  18,  49), 
the  fraction  139*-142*  also  contains  a  lutidine, 
which  was  separated  by  means  of  the  mercuric 
chloride  salt,  melting  at  186*.  This  was  de- 
composed with  potaish,  and  distilled,  when, 
after  drying,  an  oil  was  obtained  which  boiled 
at  142*-143*,  and  yielded  on  oxidation  with  per- 
manganate a  dibaido  acid  which  is  identical 
with  that  obtained  from  synthetical  lutidine 
prepared  by  condensing  cinnamio  aldehyde, 
ethyl  acetoacetate,  ana  ammonia  (Epstein, 
Annalen,  231,4).  Its  sp.gr.  is  0-9546,  and  b.p. 
143* 

The  constitution  of  the  jS-lutidine  is 


< 


CH, 
^N 
CH. 


(Ladenburg  and  Both). 

By  distilling  dimethyl  pyridine  dicarboxylic 
acid  with  lime  a  91  p.c.  yield  of  2 : 6-lutidine 
can  be  obtained.  Thus  method  appears  to  be 
the  most  convenient  way  of  preparing  pure 
lutidine  (Mumm  and  Hiincke,  Ber.  1917,  50, 
1568;   1918,51,160). 

The  isomeric  a,  jS  and  7-ethyl  pyridines  are 
also  known,  the  j3  and  7-forms  being  produced 
when  cinchonine  or  brucine  are  distilled  with 
caustic  alkali,  and  the  a-form  on  heating 
pyridinium  ethyl  iodide  to  290^. 

Lutidine-monooarboxylio  aeid  {aa* 'dimethyl' 
nicotinic  acid).  Obtained  by  distilling  lutidine- 
dicarboxyUc  acid  (Weiss,  Ber.  19,  1308).  It 
crystallises  in  fine  needles  melting  at  160*. 

Lutidine-diearboxylie  aeid  {aa'-dimeihyl-pp^- 

dicarboxylic  acid).  Obtained  by  the  oondensa- 
tion  of  wobutylaldehyde,  ethyl-  aceto-acetato, 
and  ammonia  (Engelmann,  Annalen,  231,  51 ; 
Hantzsch  and  Weiss,  Ber.  19,  284). 

LutidiDC-triearboxylle  a/d^iay-dimeihyl-pa'p'- 
tricarboxylic  acid)  is  formed  by  the  oxidation  of 
colUdine-dicarboxylic  acid  wim  permanganate. 

a-Lutidlne(2  -A-dimeihylpyridtne).  Separated 
by  adding  mercuric  chloride  to  a  solution  in  hydro  • 


chloric  acid  of  the  baMsboiliikcatl58*~160*.  The 
salt  has  the  composition  G7H,N,HGl,2Hga2, 
and  melts  at  127*.  On  distilling  with  potash,  the 
salt  is  decomposed,  and  the  iMise,  after  drying, 
boils  at  167*.  Its  sp.gr.  is  0-9493  at  0*/4*.  It  yields 
a  pyridine-dicarboxylic  acid  on  oxidation  with 
permanganate,  and  the  acid  melts  at  235*.  This 
is  known  as  a-lutidinio  acid  or  ay-pjridine- 
dicarboxylic  acid,  since  on  heating  carbon  dioxide 
is  given  ofif  and  Moniootinic  acid  is  formed. 
Hence  a-lutidine  has  the  composition 

CH, 

\ 

CH, 

(Ladenburg  and  Roth,  Ber.  18,  913). 

CiolUdines      {y-coUidinef      irimethylpyridine) 

C.NH,(CH,), 

may  be  prepared  by  distilling  coUidine 
dicarboxylic  ester  (obtained  by  oxidising 
the  condensation  product  of  aldehyde  ammonia 
and  ethyl  acetoacetate)  with  lime.  It  boils  at 
171*-172*,  and  has  the  constitution 

CH, 
/\ 
CH,l  ^CH,. 

A  base,  C,H.iN,  has  been  isolated  from 
the  fraction  of  bone  oil  boiling  between  170* 
and  180*,  but  this  has  been  shown  by  Weidel  and 
Pick  to  be  a  2-methyl-4-ethylpyrid]ne  from  the 
fact  of  its  giving  on  oxidation  lutidinic  acid  melt- 
ing at  219*.  The  base  is  more  soluble  in  oold 
than  in  hot  water.  Its  sp.gr.  is  0-9286  at  16-8*  ; 
it  boilB  at  177-8*/768  mm.  (Weidel  and  Pick, 
Monatsh.  6,  656).  These  authors  are  of  opinion 
that  Anderson's  collidine  (Phil.  Mag.  4,  9,  146, 
214)  was  impure.  The  base  does  not  form  any 
orystaUised  salts,  and  is  not  identical  with  any 
synthetical  collidine. 

Aldehydine  {2-Tndhyl-5-elhylpyridine).  Formed 
by  the  condensation  of  ethylidene  chloride 
with  ammonia  (Durkopf ,  Ber.  18,  921),  by  heat- 
ing an  alcoholic  solution  of  aldehyde-ammonia 
to  120""  (Baeyer  and  Ader,  Annalen,  155,  294), 
and  as  a  decomposition  proauct  of  cinchonine 
or  brucine  when  these  alkaloids  are  distilled 
with  caustic  alkali.  It  boils  at  176*,  and  has 
sp.gr.  0-9389  at  074**. 

Of  the  isomerides  of  collidine,  a-normal 
propyl  pyridine  (conyrine)  is  of  considerable 
theoretical  importance,  owing  to  its  relationship 
with  the  alkaloid  conine  {q.v.). 

Collidine  diearboxylle  aeid  is  obtained  bv 
oxidising  hydrocollidine-dicarboxylic  acid  with 
nitrous  acid.  The  ester  of  the  latter  acid  is  the 
product  of  condensation  of  ethyl  acetoacetate 
with  aldehyde  ammonia.  It  yields  on  heatin<r 
with  lime  aa'7-trimethylpyridine.  The  acid 
yields  by  successive  oxidation  of  the  methyl- 
groups  by  permanganate  the  following  carboxylio 
acids : 

Lutidine-tricarboxylic  acid 

C5N(CH,),(C0,H)„ 

Picoline-tetracarboxylic  acid 
C,N(CH,)(C0,H)4, 


BONE  OIL. 


635 


PvridiBe-pentacarboxylio  acid  C,N(COaH),. 

If  one  carboxyl-  group  be  removed  from  the 
original  acid  and  then  it  be  oxidised,  the  following 
acids  are  successively  obtained : — 

From  coUidine-monocarboxylio  acid 
CsNH(CUs),CO,H  the  acids  lutidine-dicarboxyUo 
acid  C5NH(GH,),(C0,H),,  picoline- tricarboxylic 
acid  C,NH(CH,)(CO,H)„  pyridine-tetracar- 
boxyUc  acid  C,NH(C0,H)4. 

Flpertdlne,  hexslhydro-pyridine,  is  obtained 
in  small  quantity  by  the  reduction  of  pyridine 
with  tin  and  hydrochloric  acid  (Konigs,  Ber. 
1881,  14,  1856).  A  better  yield  is  obtained  by 
operating  in  absolute  alconoUc  solution  witn 
sodium.  It  may  be  prepared  from  pyridine 
in  06  p.o.  yield  by  electrolytic  redaction 
(£.  Merck,  D.  B.  P.  90308;  Pin,  Ens.  Pat. 
21471).  It  may  also  be  prepared  by  heating 
piperine,  obtained  from  pepper,  with  soda  lime, 
or  by  the  reduction  of  trimethylene  cyanide  in 
alcoholic  solution  with  sodium.  It  is  a  liquid 
smelling  like  pepper  and  ammonia,  boiling  at 
105-7^  sp.^r.  0'8810  at  0^  lliscible  in  aU  pro- 
portions with  water.  It  combines  with  quinones 
to  form  dyes.  J.  y.  Braun  ( 1904)  has  shown  that 
by  benzoylation  of  piperidine  and  subsequent 
heating  with  phosphorus  pentachloride  to  250^ 
the  cyclic  system  is  destroyed  and  a  ^ood  yield 
of  pentamethylene  dichlonde  is  obtamed,  such 
l*5-dichloro-compounds  being  very  difficult  to 
obtain  by  ordinary  B3mthetio  methods. 

CH,CH, 
C,HjCON/^^CH, 

CH,    CH, 

CHjCH, 

->  c,h,cci,n/~\oh, 

CH,    CH, 
^         C.H.CN+ClCCHJ^a 

Its  combination  with  hydroquinone,  pyro 
catechin,  and  several  other  phenols,  has  been 
patented  by  Joseph  Turner  &  Co.,  Ltd.  (B.  B.  P. 
98466). 

An  account  of  the  physiological  action  of 
piperidine  and  allied  compound  is  given  by 
WolfiFenstein  (Ber.  34,  2410). 

Piperidine  guaiacolate  prepared  by  the 
action  of  piperidine  on  euaiacol  dissolved  in 
benzene  or  petroleum  melts*  at  79*8*^.  It  is 
used  in  the  treatment  of  phthisis  (Pharm.  J. 
1897,  81),  and  is  important  as  combining  the 
properties  of  a  strong  vascular  and  nervine 
tome — ^piperidine — ^with  an  antiseptic  guaiacol 
(Tnnnicliffe,  Chem.  Soc.  Trans.  1898,  146). 

Various  derivatives  of  piperidine  have  been 
synthesised  by  Ahrens  (Ber.  1898,  2278). 

Qulnoline.    See  Quinounb. 

COLOUBUCO   MaTTXBS  DXSIVED  niOM  BONS-OIL 

Bases. 

1.  From  Pyrrole.  A  red  dye  may  be  obtained 
from  pyrrole  by  treating  cotton  doth,  after 
dipping  in  a  weak  alcoholic  solution  of  bitter 
almona  oil  (benzaldehyde),  with  alcoholic 
pyrrole  solution,  hydrochloric  acid,  ferxio 
chloride,  and  gently  warming.  A  black  colour 
is  obtained  by  substituting  cinnamon  oil  (cinna- 
mic  aldehyde)  (Chem.  Zeit.  1890,  348). 


Pine  wood  may  be  dyed  red  b^  moistening 
with  hydrochloric  acid,  and  treating  with  the 
vapour  of  pyrrole. 

Pyrrole  olue  may  be  obtained  in  two  yazie- 
ties :  (a)  by  mixing  pyrrole  and  isatin  (1  mol.  of 
each)  in  sulphunc  acid,  yielding  the  '  A ' 
variety;  and  (6)  by  operating  in  acetic  acid 
under  specified  conditions,  when  pyrrole  blue 
*  B  '  is  obtained  with  a  certain  amount  of  A. 
Pyrrole  blue  B  has  a  metallic  lustre,  and  is  much 
less  soluble  than  pyrrole  blue  A.  P3rrrole  blue  A 
cannot  be  acetylated,  but  on  treating  pyridine 
solution  with  acetic  anhydride  a  small  amount  of 
the  pyrrole  blue  B  derivative  is  obtained.  This 
acetyl  derivative  dissolves  in  sulphuric  acid 
to  a  magenta  solution,  which  rapidly  changes 
to  a  cornflower  blue,  owing  to  the  formation  of 
a  disulphonic  acid.  This  acid  is  very  soluble 
in  water  and  dyes  silk  blue  (Liebermann  and 
Hase,  Ber.  1906,  2847  ;  «ee  also  Ber.  17,  1034). 

2.  From  Pyridine.  Pyridine  dyestuffs  mav 
be  obtained  by  diazoUsing  aminobenzyl- 
pyridine,  and  combining  with  the  usual  com- 
ponents. Aminobenzylpyridine  is  obtained  by 
reducing  the  nitro-  compound  produced  by  the 
condensation  of  nitrobenzyl  chloride  and  pyri- 
dine bases.  These  products  dye  tannin-mor- 
danted cotton,  or  wool  and  cotton  from  an 
acid-bath  (Farb.  vorm.  Meister,  Lucius  and 
Bruning,  Eng.  Pat.  4646). 

When  mixtures  of  pyridine  (1  moL)  and 
aromatic  amines  (2  mols.)  are  acted  upon  by 
cyanogen  chloride  or  bromide  dyestufifs  are 
formed  practically  quantitatively  and  very  pure, 
with  the  elimination  1  mol.  of  oyanamide. 
They  crystallise  well,  and  vary  from  yellow, 
through  orange  and  red,  to  violet,  and  <we  silk 
in  shfules  showing  fine  fluorescence ;  ana  some 
show  marked  afuiity  for  unmordanted  cotton. 
They  are  soluble  in  water  with  difficulty,  more 
readily  in  acetic  acid  and  alcohol,  and  in  pyridine 
(W.  Konig,  J.  pr.  Chem.  1904,  106). 

3.  Ffom  Piperidine.  The  quinones  (benzo-, 
tolu-,  naphtha-,  phenanthra-quinones)  interact 
with  piperidine,  yielding  colouring  matters  which 
are  readily  chansed  by  acids  and  alkalis.  The 
compouna  with  benzoquinone  CfH,0,(NC,H,o), 
forms  thick,  reddish-violet  pnsms  with  blue 
reflex,  meltinff  at  178^  Neutral  or  alkaline 
solutions  are  blood-red,  acid  solutions  carmine 
(Lachowicz,  Monatsh.  1888,  606). 

Isatin  blue'  is  derived  from  piperidine  as 
follows:  Dipiperidyl  (satin  is  prepared  by 
heatinff  an  alcoholic  solution  of  isatia  ( 1  moL )  with 
(2  moLs.)  piperidine  on  the  water-bath  for  an 
hour,  ana  crystallising  from  alcohol.  Isatin 
blue  results  fsom  heating  this  compound  to 
125^-160?  in  a  current  of  air,  or  by  SjgitatiAe 
with  acetic  anhydride  at  60°  for  some  time  ana 
pouring  into  water.  It  forms  indigo-blue 
solutions  in  alcohol,  ether,  or  acetic  acid,  and 
is  insoluble  in  benzene  or  chloroform.  It 
may  be  heated  without  change  to  160*,  but  is 
completely  decomposed  at  230*  (Schotten, 
Ber.  1891,  1366). 

p-Aminophenyl  piperidine,  which  may  be 
compared  with  p-aminodimethyl  aniline, 
reacts  ia  many  cases  in  a  similar  way  to  this 
compound.  When  oxidised  with  a  primary, 
secondary,  or  tertiary  amine,  indaminea,  varyins 
from  blue  to  green  are  poduced.  Oxidised 
in  the  presence  of  meta-diamines,  compounds 


636 


BONE  OIL. 


may  be  piecipitated  by  meaoa  of  zinc  chloride 
which  dye  oofton  blue. 

With  phenol,  when  oxidised  with  the  theo- 
xetioal  quantity  of  potaaaium  ferrioyanide,  a 
blue  indophenol  is  obtained*  With  naphthola 
violet  colouzB  result.  Other  colours  are  also 
described  by  Lellmann  and  Geller  (fier.  1888, 
2287). 

Literature. — Anderson,  Trans.  Roy.  Soo.  Edin. 
16,  463  ;  20,  247  ;  21,  219 ;  21,  671  ;  Annalen, 
70,  32  ;  84,  44  ;  94,  358  ;  106,  335 ;  Weidel, 
Sitz.  Ber.  79,  837  ;  80,  443  ;  80,  821 ;  81,  512 ; 
90,  972;  Giamician,  Ber.  1904,  4200^255; 
Bamberi^,  Ber.  1891,  1758 ;  and  in  general  the 

ekpers  of  the  following :  Giamician,  I>ennstedt, 
oogewerff  and  van  Doxp,  laebermann,  Oeduner 
de  (x>ninok,  and  Weidef. 

BONE  PHOSPHATES  v.  Fbbtiusxbs. 

BOOKUM  or  SAPPAH  WOOD.  An  Indian 
wood,  the  product  of  Cmsaipinia  8appan  (Idnn.). 
Used  in  dyeing  reds. 

BOOltAH  NUTS.  The  fmit  of  Pycnocama 
maerophyUa  (Benth.),  belonging  to  the  Euphor- 
biaces.  Used  in  tanning  (Holmes,  Pharm.  J. 
[3]  8,  363). 

BORACIC  or  BORIC  ACU)  v.  Bobov. 

BORACITE.  Borate  and  chloride  of  mag- 
nesium, 6MgO*MgGl|*8BsOa,  forming  smafi, 
bright,  sharply-developed  cubic  crystals  of 
tetrahedral  symmetry,  m  which  the  cube  faces 
usually  predominate.  The  crystals  are  interest- 
ing on  account  of  their  strong  pyro-electrical 
characters,  and  the  optical  anomalies  which  they 
exhibit.  Each  cubic  crystal  is  built  up  of 
twelve  rhombic  pyramids,  the  bases  of  which 
coincide  with  the  twelve  faces  of  the  rhombic- 
dodecahedron  and  the  apices  meeting  in  the 
centre  of  the  group.  At  a  temperature  oi 
265°  the  birefringence  and  twin-lameU»  dis- 
appear and  the  crystal  is  then  truly  cubia  This 
affords  a  good  example  of  an  enantiotropic 
change  in  state,  the  cubic  modification  being 
stable  only  above  this  temperature.  The 
crystals  usually  occur  embedded  m  gypsum,  and 
are  bounded  on  all  sides  by  brigtit  facets. 
Sp.gr.  2'9~3'0,  H  7  (as  high  as  that  of  quartz). 
Ijiey  are  found  in  considerable  numbers  at 
Liinebuig,  in  Hanover,  and  at  Stassfurt,  and 
elsewhere  in  the  Prussian  salt-deposits.  A 
massive  earthy  variety,  known  as  *  stasisfurthite,* 
occurs  as  nodules  at  Stassfurt  in  quantities 
sufficiently  large  for  collecting  for  commercial 
purposes.  J.  L.  S. 

BORAL  V,  Synthbtic  dbuos. 

BORATES  V.  Bo^oN. 

BORAX.  As  a  mineral,  borax  (Na^B^O}, 
10H,0)  is  found  as  an  efflorescence  and  as  mono- 
clinic  crystals,  sometimes  of  considerable  size, 
on  the  shores  of  the  salt  lakes  of  Tibet  and 
California.  In  San  Bernardino  and  Lake 
counties  m  Galifomia  there  are  several  places 
known  as  *  Borax  Lake  * ;  but  most  of  the 
borates  commercially  mined  in  this  region 
belong  to  other  species  ( ulexite,  colemauite,  &  c. ). 
The  Tibetan  deposits  extend  from  the  lake- 
plain  of  Pugha  in  the  west  to  the  lakes  of 
Tengri  Nur  in  the  east,  and  formerly',  since  very 
early  times,  much  crude  material  was  exported 
under  the  name  of  tincal  (v.  Boron.)      L.  J.  S. 

BORDEAUX  V.  Azo-  coLouBiNa  mattebs. 
Lambert  (2<eit8ch.  anal.  Chem.  22,  46)  detects 
this  dye  in  wines  by  precipitating  with  basic 


lead  acetate,  and  extracting  the  precipitate 
with  alcohol ;  the  red  solution  thus  obtained 
is  turned  yeJlow  by  alkalis.  Wool  heated  with 
the  wine  withdraws  its  colouring  matters. 

BelUer  (J. -Pharm.  Chim.  [6]  14,  7)  describes 
a  method  of  determimng  quantitatively  the 
amount  of  this  dye  in  wines. 

BORDEAUX  MIXTURE  v.  Plant  sfbayb. 

BORNEO  CAMPHOR  v.  GiLMPHOBs. 

BORNEOL  V,  Cabcphobs  ;   Tebfbnbs. 

BORNEO  TALLOW  is  a  generic  term  for 
a  large  variety  of  fats  obtained  from  the  kernels 
of  a  number  of  plants  belonging  to  the  Diptero- 
carptu  family,  such  as  Shorea  slem^ptera  (Burck.), 
SJtorea  altera  (Burck.),  Hopea  asvera  (de  Verise), 
Pentacme  siameneis  (Kurz),  all  of  which  arc 
indigenous  to  the  Sunda  Islands,  Indo-Ciuna, 
and  the  Malay  States.  All  the  fata  derived 
from  these  trees  are  also  in  commerce  known 
under  the  native  name  of  Ifinjak  Tangkawang 
(Tangkawang  Fat).  Minjak  Tangkawaiig  repre- 
sents a  mixture  of  at  least  six  fats,  obtained  m>m 
six  varieties  of  trees  known  to  the  natives  as 
Tangkawanff  toengkoel,  T.  rambei,  T.  lagar 
(these  trees  nave  a  diameter  of  more  than  3  ft.), 
T.  goentjang  (ffrowins  in  swampy  rM^ions,  and 
reaching  a  height  of  22  ft., whilst  the  diameter  of 
the  trunk  rarely  exceeds  6  inches),  T.  madjan, 
T.  terindak.  The  trees  frmt  only  at  irregular 
intervals,  the  nuts  vielding,  according  to  the 
species,  ^m  about  43  to  61  p.c.  of  fat. 

The  fat  ia  prepared  bv  the  natives  in  a 
ver^  crude  manner.  In  the  *  wet  process '  the 
fruits  are  placed  in  baskets,  immersed  in  water, 
and  left  therein  for  from  30  to  40  days.  After 
that  time'  the  shells  are  removed,  the  kernels 
are  split  into  four  parts,  and  these  spread  on 
boanu,  exposed  to  the  sun  to  dry.  The  dried 
fruit  is  then  pounded,  boiled  with  water,  and 
the  liquid  fat  skimmed  off  and  moulded  in  the 
intemodes  of  bamboo  stems;  hence  the  com- 
mercial samples  have  a  cylindrical  shape. 
The  '  dry  process '  consists  in  cutting  the  kernels 
into  diBcs  immediately  after  the  fmit  has  been 
Golleotod,  drying  the  discs  by  exposure  to  the  sun, 
and  subsequently  pressinir.  The  fat  obtained 
by  the  d^  process  Yields  the  best  product, 
which  ia  laiseiy  used  lor  ediUe  purposes  in  the 
East.  The  Icemels  of  the  Shorea  fruit  (errone- 
ously described  in  commerce  as  '  Illipe  nuts,' 
se^  Bassia  Oils),  are  shipped  to  Europe,  where 
they  are  expressed,  and  the  fat  is  used  in  the 
manufacture  of  candles  and  as  a  substitutes  for 
cacao  butter.  The  commercial  grades  are 
described  as  *  lacge  black  Pontianac  illipe  nuts,' 
and  *  large  Pontianac  or  Sarawak  ilhpe  nuts 
without  guarantee  of  colour.'  *  Siak  illipe  nuts  * 
are  smalfor,  and  yield  a  softer  fat ;  they  are  the 
product  of  a  species  of  Paiaqudum  (N.  0. 
aapotacece). 

In  1913,  8275  cwt.  of  illip^  nuto,  valued  at 
£6954,  were  exported  from  Singapore,  principally 
to  Belgium,  whilst  small  quantities  were  sent  to 
the  United  States  and  to  England  (BulL  Imp. 
Inst.  1015,  23,  335). 

Borneo  tallow  contains  considerable  quanti- 
ties of  stearic  acid.  Samples  examined  in  the 
writer's  laboratoiv  contained  as  much  as  66  p.c. 
of  stearic  acid.  The  fat  melts  at  29'*-3S'* ;  and 
has  iodine  value  31-35*9;  and  saponification 
value,  190-4-194'5.  The  insoluble  fatty  acids 
have  a  high  melting-point,  viz.  5Z**-6S^,  and  seem 


BORON. 


©37 


to  oonfliBt  of  66  p.o.  of  stearic  acid  and  34  p.o.  of 
oleic  acid.  The  fat  separated  from  the  kernels 
in  Europe  nsually  contains  a  high  proportion  of 
free  fatty  acids,  the  acid  value  of  the  product  of 
Pontianac  nuts  being  as  high  as  35. 

The  fats  from  Shorea  Ohytbertiana  and 
from  Isoperta  bomensis  have  been  described  as 
Enkabang  fat  and  Teglam  fat  respectively 
(Brookes,  Analyst,  1009,  206).  J.  L. 

BORHEBPT  V.  Glucosidis. 

BORNITE.  A  sulphide  of  copper  and  iron, 
of  importance  as  an  ore  of  copper  (Cu  46-71  p.c). 
On  a  freshly  fractured  suriaoe  the  colour  is 
dark  bronze,  but  this  quickly  tarnishes  to  purple 
or  deep  reddish ;  hence  the  names  purple 
copper-ore,  variegated  copper-ore  (Buntkup- 
fererz),  erubescite,  and  the  C!omish  miner^s 
name  hone*flesh-ore.  Further  alteration  pro- 
duces a  black  sooty  coating.  The  massive  ore 
is  always  much  interminffled  with  copper- 
pyrites,  and  even  the  rardy  occurring  cubic 
crystals  usually  contain  a  nucleus  of  copper- 
pyrites.  The  exact  composition  of  the  mineral 
nas  therefore  long  been  doubtful;  analyses 
by  B.  J.  Harrington  (1903)  and  £.  T.  Allen 
(1916)  of  carefully  selected  material  gave  the 
formula  Cu.FeS4.  This  is  the  bomite  of  W. 
Haidin^r  (1845) :  bomite  of  F.  8.  Beudant 
(1832)  IS  an  obsolete  synonym  of  tetradymite  or 
telluric  bismuth.  L.  J.  8. 

BORNYVAL.  Pharmaceutical  name  for  the 
Movalerianic  ester  of  bomeol  GioHifO'CjHtO, 
a  limpid  fluid  smelling  like  valerian,  insoluble 
in  water,  freely  soluble  in  alcohol  or  ether; 
b.p.  266°-260^;  sp.gr.  0951  at  20°,[D],o= 
27°  40'. 

BOROFORM.  Trade  name  for  a  solution  of 
formaldehyde  in  sodium  glyceroborate. 

BORO-GLTCERINE.  An  antiseptic,  patented 
by  Bar£F  (D.  R.  P.  18108;  Eng.  Pat.  5906, 
1884),  prepared  by  heating  92  parts  glycerol 
with  62  parts  of  Iwric  acid  at  200"".  It  is  a 
yellowish,  trannmrent  substance,  soluble  in 
alcohol  and  in  40  parts  of  water.    Used  as  a 

ffreservative  for  fruits  and  wines  (J.  8oc.  Ghem. 
nd.  1,  244  ;  4,  362). 

BORON.  B.  At.  wt.  10*90  Smith  and  van 
Haagen.  An  element  usually  reckoned  aniong 
the  metalloids,  although  it  presents  analogies  to 
the  metals,  and  has  been  placed  by  JBtard 
(Compt.  rend.  91,  627)  at  the  head  of  the  vana- 
dium group,  intermediate  between  the  places 
of  phosphorus  and  carbon ;  is  a  triad  in  most  of 
its  known  combinations,  but  is  also  capable  of 
acting  as' a  pentad  (Michaelis  and  Becker,  Ber. 
13,  58).  Never  occurs  free;  usually  as  boric 
acid,  and  in  several  minerals,  as  borax  or  tinealf 
horacite,  hydroboraeiU,  rhodiziie,  saaaoiiU,  horoctU- 
ciie,  horonatroealeitef  and  botryoliie,  and  in  small 
quantities  in  schorl,  daUHiie,  tourmaline,  apyrite, 
and  axiniie.  Minute  quantities  of  boron  are 
found  in  mineral  waters ;  in  sea- water;  in  plant 
ashes,  and  in  animal  tissues. 

The  element  was  first  isolated  by  Gay-Lussao 
and  Th^nard  in  1808,  by  heating  boric  oxide 
with  potassium.  According  to  Wohler  and 
Deville  (Ann.  Ohim.  Phys,  [3]  62,  63),  it  may  be 
obtained  by  mixing  60  grains  of  sodium  in  small 
pieces  with  100  grams  of  powdered  boric  oxide 
m  an  iron  crucible,  covering  the  mixture  with 
a  layer  of  30  grams  ignited  sodium  chloride  in 
fine  powder,  and  heating  the  whole  to  redness. 


After  the  completion  of  the  reaction,  which  is 
very  violent,  the  mixture  is  stirred  with  an  iron 
rod,  until  the  sodium  and  sodium  chloride  are 
fused,  and  carefully  poured  into  dilute  hydro- 
chloric acid,  and  the  residue  washed  with  water 
containing  ammonium  chloride  (which  salt 
is  subsequently  removed  by  alcohol)  and  dried. 
Boron  can  also  be  obtained  by  heating  potassium 
borofluoride  with  potassium  (Berzelius),  or 
magnesium  (Wohler  and  Deville) ;  by  the 
ele^rolyais  of  fused  boric  oxide  (I>avy) ;  by 
reducing  boron  trichloride  by  hydrogen  (Dumas), 
or  preferably  with  hydrcMy^  in  the  high  tension 
electric  arc ;  by  fusing  borax  with  amorphous 
phosphorus  (DragendOTff) ;  by  heating  boric 
oxide  with  magnesium  or  calcium,  and  treating 
the  residue  with  dilute  hydrochloric  acid.  Boron 
may  also  be  obtained  by  the  dissociation  of  the 
nitride,  or  of  magnesium  boride  at  high  tempera- 
tures. 

Wohler  and  Deville's  method  gives  a 
product  containing,  in  addition  to  boron, 
compounds  of  boron  with  sodium,  iron,  and 
hydrogen,  and  boron  nitride.  The  host  method 
is  that  of  Moissan,  as  modified  by  Weintraub 
(J.  Ind.  Enff.  Ghem.  1911,  3,  299 :  1913, 5,  106). 
Pure  and  arv  boric  oxide  is  intimately  mixed 
with  as  mucn  masnesium  filings  as  will  suffice 
to  reduce  one-thira  of  it.  The  mixture  is  placed 
in  an  earthenware  crucible  in  a  furnace  at  a 
bright-red  heat,  when  the  reaction  proceeds  at 
once  rather  violently.  Heating  is  continued  for 
ten  minutes  and  the  mass  allowed  to  cool.  The 
middle  portion  of  the  mass,  which  is  of  a  reddish 
colour,  IS  mechanically  separated  from  the  sur- 
rounding black  portion  as  completely  as  possible, 
and  boifed  with  a  laige  excess  of  dilute  hydro- 
chloric add  which  removes  the  boric  acid  and 
borides  of  magnesium.  The  maenesium  borate  is 
removed  by  repeated  boiling  with  strons  hydro- 
chloric acid :  and  the  silica  (resulting  from  the 
disintegration  of  the  crucible)  by  heatii^  the 
residue  in  a  platinum  vessel  witn  hydrofluoric 
acid.  The  residue  is  washed  by  decantation 
with  water  and  dried.  It  is  then  approximately 
pure,  but  still  contains  a  small  Quantity  of  a 
magnesium  boride  which  cannot  oe  got  rid  of 
except  by  fusing  the  product  with  about  fifty 
times  its  weight  of  boric  oxide,  and  repeating  the 
above  operations. 

The  product  when  heated  in  vacuo,  at  a 
sufficiently  high  temperature^  or  when  heated 
to  bright  redness  in  hydroffen  with  excess  of 
maonesinm  or  sodium,  and  extracted  succes- 
mrSiy  with  water,  hydrochloric  acid  and  hot 
dilute  nitric  add  yielcis  pure  boron  (Ray.  Ghem. 
Soc.  Trsns.  1914,  105,  2162). 

Boron  has  been  produced  by  Weston  and 
Ellis  (Trans.  Faraday  Soc.  1907,  170)  by  the 
action  of  aluminium  powder  on  boric  oxide. 
If  2  mols.  of  boric  oxide  to  2  atoms  of  aluminium 
are  used,  the  chief  product  is  boron,  but  with  a 
smaller  proportion  of  boric  oxide  aluminium 
boride  is  produced  to  a  large  extent. 

Boron  may  be  prepared  electrolytically  as 
follows :  A  fused  metallic  borate  is  electrolysed 
between  carbon  poles  separated  so  as  to  prevent 
the  boron  floating  to  the  cathode.  By  the 
use  of  a  high-current  densi^  at  the  anode 
sufficient  heat  is  generated  to  effect  the  reduction 
of  the  boric  oxide  which  collects  there  (U.S.  Pat. 
785962). 


638 


BORON. 


Commercial  boron  is  purified  by  |[rindiiig 
the  product  obtained  by  heating  bone  oxide 
and  magnesium  with  hydrochloric  acid,  and 
quickly  pouring  off  the  upper  liquid.  This 
contains  matter  in  suspension  which  holds 
a  higher  proportion  of  impurities  than  does 
the  residue  at  the  bottom.  This  process  of 
*  fractional  decantation'  is  repeated  several 
times.  The  residual  boron,  which  may  still 
contain  boron  hydride,  magnesium  boride, 
boric  oxide,  and  a  borate,  is  compressed  into  a 
thick  stick  or  cake,  and  heated  to  1200**  in  a 
vacuum  electric  furnace,  which  either  volatilises 
or  dissociates  all  these  impurities.  The  pure 
boron  is  then  melted  down  in  the  are  in  a 
current  of  inert  gas,  preferably  hydrogen.  The 
resulting  boron  is  a  dense  solid  substance  which 
conducto  electricity  and  is  completely  fusible 
without  apparent  volatilisation  (British  Thom- 
son-Houston Co.,  Eng.  Pat.  1197,  1907). 
Colloidal  solutions  of  boron  have  been  prepared 
by  Gutbier  (Kolloid.  Zeitsch.  1913,  13, 137). 

The  amorphous  boron  described  by  Moissan 
and  others  as  a  chestnut-coloured  powder  of 
sp.er.  2 '45  always  contains  oxygen,  and  appears 
to  be  a  solution  of  a  lower  oxide  of  boron  and  of 
magnesium  oxide  in  boron  in  the  superfused 
liquid  state ;  it  is  tasteless,  odourless,  staining 
the  fingers  strongly ;  becomes  denser  on  being 
heated  in  a  vacuum  or  in  gases  which  have  no 
action  upon  it ;  not  oxidised  at  ordinary 
temperatures  in  cither  air  or  oxygen ;  heated 
in  air,  it  bums  with  a  reddish  light,  forming  Bfi^ 
and  BN ;  bums  with  dazzling  brightness  in 
oxygen,  forming  B^O,.  Boiling  water  has  no 
action  on  it,  but  it  is  readily  oxidised  by  strong 
nitric  acid  in  the  cold,  and  by  sulphuric  acid 
when  heated.  When  heated  to  redness  with  the 
alkaline  salts  of  oxyacids,  yields  an  alkaline 
borate,  the  formation  being  frequently  attended 
with  incandescence,  and  in  the  case  of  nitre  with 
explosion.  Heated  with  potash  it  forms  po- 
tassium borate  with  liberation  of  hydrogen,  and 
reduces  the  chlorides  of  lead,  gold,  mercury,  and 
silver,  and  sulphide  of  lead,  chloride  or  sulphide 
of  boron  being  formed  (Wohler  and  Deville,  l.c, ; 
and  Annalen,  105,  72).  Heated  in  nitrogen,  it 
forms  white  boron  nitride.  It  decomposes  nitric 
oxide  at  a  red  heat,  burning  brilliantly  and  form- 
ing boric  oxide  and  nitride,  but  apparently  has 
no  action  on  nitrous  oxide*.  {Cf.  RroU,  Zeitsch. 
anoig.  Chem.  1918,  102,  1.) 

Crystalline  boron— the  only  pure  form  of 
boron — ^is  a  black  solid  of  sp.gr.  2 '34,  almost  as 
hard  as  diamond,  and  only  inferior  to  it  in 
touffhness  and  strength.  Melts  at  about  2200^, 
and  has  a  sensible  vapour  tension  at  1600°. 
Rapidly  increases  in  electrical  conductivity  when 
heated.  It  may  be  obtained  by  placing 
8  parts  of  aluminium  with  10  parts  of  fused  boric 
acid  in  a  gas-carbon  crucible  filled  up  with 
ignited  charcoal  and  placed  inside  another 
crucible  of  graphite  which  is  heated  to  1600°, 
for  five  hours.  The  aluminium  is  removed  from 
the  resulting  mass  by  means  of  fairly  strong 
soda,  and  the  residue  is  then  boiled  out  with 
hydrochloric  and  hydrofluoric  acids.  The  re- 
sidue contains  some  alumina  which  is  separated 
mechanically  as  far  as  possible,  and  completely 
by  glacial  phosphoric  acid.  Crystals  may  also 
be  obtained  by  heating  2  parts  of  fused  and 
powdered   borax  with   1   part  of  magnesium. 


A  oommerdal  prooesB  has  been  patented  by 
Kuhn  (Chem.  Zentr.  1904,  i.  64).  Boron  com- 
pounds are  mixed  with  sulphur  and  aluminium, 
and  the  mixture,  which  bums,  u^nited.  Crystals 
of  boron  are  found  in  the  resulting  mass,  and  are 
separated  from  it  by  extraction  with  water, 
which  decomposes  the  aluminium  sulphide, 
forming  aluminium  hydroxide  and  H^S,  and 
leaving  the  crystals  of  boron. 

It  18  only  oxidised  with  very  great  difficulty 
in  oxygen,  and  in  air  no  change  tiucee  place  even 
at  2000°.  Molten  potash  or  lead  chromate 
oxidises    it    with    mcandescenoe,    but    fused 

Sotassium  nitrate  does  not  affect  it.  *  Boron 
iamonds  '  of  the  composition  Bt^CtAlg  (Hampe) 
(C2AI3B44,  Biltz)  may  be  obtained  by  strongly 
heating  a  mixture  of  boron  trioxide,  sulphur, 
aluminium  and  soot.  The  fused  mass  gives  a 
mixture  of  yellow  transparent  quadratic  cr3rstals 
mixed  with  black  opaque  crystals  of  AlB^,, 
which  can  be  separated  by  fractional  flotation  in 
a  mixture  of  methylene  iodide  and  benzene,  the 
yellow  quadratic  crystals  being  slightly  heavier 
than  the  others.  They  are  not  attacked  by  hot 
strong  hydrochloric  or  sulphuric  acids,  or  by  a 
solution  of  chromic  anhydride  in  >strong  sul- 
phuric acid  (Biltz.,  Ber.  1910,  43,  297). 

Boron  may  be  introduced  into  st€»el,  and  the 
properties  of  the  boron  steel  so  obtained  have 
Deen  studied  by  Osmond  (Compt.  rend.  110, 
242,  and  346),  by  Moissan  and  Charpy  {Qnd, 
120,  130),  by  L.  Guillet  {ibid.  144,  1049),  and  by 
Hannessen  (Zeitsch.  anoig.  Chem.  1914,  89, 257). 
Boron  steels  are  obtained  either  by  heating 
amorphous  boron  with  reduced  iron  in  a  current 
of  hydrogen,  or  by  adding  ciystalline  boron  to 
the  molton  metal.  On  hardening  by  heating 
to  a  known  temperature  and  quenching,  boron 
steel  behaves  luce  a  high-grade  hard  carbon 
steel  as  regards  increase  in  tensile  strength, 
whilst  the  diminution  in  extension  is  not  so 
great.  The  hardness  of  boron  steel  is  not  much 
affected  by  heating  and  quenching.  The  special 
effect  of  boron  appears  to  be  to  communicate 
to  the  steel  a  hign  tensile  strength  rather  than 
actual  hardness  when  the  metal  is  heated  and 
quenched. 

Boron  rapidly  reduces  manganese  oxides  in 
the  electric  furnace.  With  excess  of  oxide 
products  containing  up  to  97  p.o.  manganese, 
may  be  obtained  whicn  are  soft  enough  to  be 
filed.  With  excess  of  boron,  harder,  granular 
substances  result,  containing  up  to  20  p.c.  boron. 
From  these  a  definite  boride  MnB  may  be 
isolated.  It  is  a  crystalline  metallic  powder 
attacked  by  halc^ens  and  oxyeen  at  high 
temperatures,  and  by  alkali  hydroxides  and 
carbonates  at  a  red  heat.  Water  or  steam 
slowly  decomposes  it  with  evolution  of  hydrogen 
(Binet  du  Jassonneix,  Compt.  rend.  139,  1209). 
The  same  author  has  obtained  very  similar  results 
with  molybdenum  dioxide  and  boron  (Compt. 
rend.  143,  169) ;  and  has  also  mepared  two 
definite  borides  of  chromium  Cr,B,  and  CrB, 
by  fusing  together  chromium  and  boron.  They 
are  very  s^ble  towards  reagents,  especially 
the  former,  but  are  decomposed  by  fused 
alkalis,  and  by  chlorine  at  a  red  heat.  They 
are  soluble  in  hydrofluoric,  hydroohlorio,  and 
concentrated  sulphuric  acids  (Compt.  rend. 
143,  1149).  The  same  author  has  also  prepared 
Ni,B,  NiB„  Co,B,  and  CoB,  (Compt.  rend.  145, 


BORON. 


639 


240)  J  and  boridea  of  zirconium,  chromium, 
tungsten,  and  molybdenum  have  been  prepared 
by  Tucker  and  Moody  (Chem.  Soc.  Proc.  1901, 
129) ;  and  borides  of  vanadium,  uranium  and 
titanium  by  Wedekind,  Horst  and  Jochem 
(Ber.  1913,46,1198). 

comfoukds  07  bobon  with  non- metallic 

Elshbnts. 

Boron  hydrides  are  formed  by  dissolving 
magneflium  boride  in  hydrochloric  acid,  or  more 
easuy  by  dissolving  commercial  ferroboron  in 
dilute  sulphuric  acid.  Spontaneously  inflam- 
mable. Boron  hydrides  admixed  with  hydrogen 
are  evolved,  and  an  insoluble  residue  formed. 
The  gases  have  a  characteristic  smell,  and  de- 
compose a  moderately  concentrated  silver 
nitrate  solution,  forming  a  blackish- brown  pre- 
cipitate with  metidlic  lustre.  They  bum  with  a 
green  flcune  and  form  a  mirror  when  passed 
through  a  red-hot  glass  tube  (HofiFmann,  Chem. 
Zeit.  1911,  35,  265). 

Four  unstable  hydrides  have  been  isolated, 
B,H|,  BJ3,o,  BcH„,  and  a  solid  hydride 
B10H14.  Boron  hydride,  B4H10,  is  a  colourless 
liquid,  b.p.  16*'-177760  mm.;  m.p.  ca. -112°, 
of  a  peculiar  and  most  disagreeable  odour. 
A  few  Dubbles  of  the  gas  affect  respiration  and 
cause lieadache.  It  is  a  very  unstable  substance, 
decomposing  at  the  ordinary  temperature  after 
a  few  hours,  especially  unaer  the  influence  of 
ultra-violet  light,  and  quicker  at  higher  tempera- 
tures, giving  rise  to  B  ^Hg.  It  is  similarly  decom- 
posed by  electric  sparks.  It  takes  fire  spon- 
taneously in  the  air  or  in  oxygen,  burning  with  a 
green  flame.  Water  and  £lute  hydrochloric 
acid  decompose  it,  and  it  is  oxidised  by  concen- 
trated nitric  acid  with  explosive  violence.  It  is 
rapidly  absorbed  by  aqueous  sodium  hydroxide, 
the  solution  slowly  evolving  hydrogen.  Am- 
monia gives  a  solid  light  brown  substance, 
insoluble  in  water,  whilst  alcohol  decomposes 
the  hydride  with  evolution  of  hydrogen.  The 
solution  in  benzene  is  very  stable  towards 
oxygen. 

The  hydride  B^Hu  is  a  colourless  liquid, 
b.p.  10715  mm.  ea.  1007760  mm.,  possessing  a 
highly  disagreeable  odour  and  taking  fire 
spontaneously  in  the  air.  It  is  more  sensitive 
towards  water  and  moisture  than  the  hydride 
BaHiq.  With  aqueous  alkalis,  hydrogen  is 
immediately  evolved  (Stock  and  Massenez, 
Ber.  1912,  45,  3568). 

B^H^  is  a  colourless  gas  possessing  a  cha- 
racteristic, repulsive  odour,  resembling  that  of 
the  hydride  B4H10.  B.p.  —ST  to  -88°/760  mm., 
m.p.  —169^  It  is  more  stable  than  B4H10, 
but  decomposes  slowly  at  ordinary  tempera- 
tures. It  only  takes  fire  in  the  air  when  mixed 
with  other  boron  hydrides.  With  alkalis,  it 
reacts  similarly  to  B4H,o ;  with  sodium 
hydroxide  it  gives  solutions  containing  hypo- 
borates. 

The  formula  B^H,  shows  that  boron  must  be 
at  least  quadrivalent  and  not  tervalent  as  a 
maximum,  as  it  should  be  according  to  its 
position  in  the  periodic  system  (Stock  and 
Friederici,  Ber.  1913,  46,  1959). 

The  solid  hydride  B^qHi^  obtained  by  heating 
the  other  hydrides  is  a  colourless  substance  with 
a  penetrating  peculiar  odour,  dissimilar  to  that 
of   the  gaseous   hydrides.     It   sublimes  in  a 


vacuum  giving  long  needles,  m.p.  99'6 ;  D  0*94. 
Not  attacked  b^  water,  even  when  boiling, 
soluble  in  alkahne  hydroxide,  giving  intense 
yellow  solutions  (Stock,  Friederici  and  Friess, 
Ber.  1913,  46,  3353). 

All  the  hydrides  when  treated  with  caustic 
alkalis  evolve  hydrogen  and  form  alkaline 
hypoborates:  thus  with  potassium  hydroxide, 
B4H,o+4KOH=4KOBH,+H,.  The  solutions 
of  the  hypoborates  thus  formed  are  stable  for 
hours  at  0°,  but  on  boiling  they  decompose 
rapidly.  Potassium  hypoboraie  KOBH,  forms 
glistening,  octahedral,  colourless  crystals  which 
are  stable  in  dry  air.  It  is  deliquescent,  and  its 
solutions  gradually  decompose  at  ordinary 
temperatures,  evolving  hydrogen  and  forming 
potassium  borate.  The  aqueous  solution  is  a 
strong  reducing  agent,  giving  witii  copper  salta  a 
precipitate  of  copper  hydride,  and  with  nickel 
salts  black  insoluble  nickel  boride,  Ni^B  (Stock 
and  Kuss,  Ber.  1914,  47,  810.  For  action  of 
halogens  on  the  hydrides,  see  Stock,  Kuss  and 
Priess,  Ber.  1914, 47,  3115). 

Boramlde  B(NH,),  is  formed  together  with 
ammonium  chloride  by  the  action  of  ammonia 
on  boron  trichloride  at  a  low  temperature 
(Joannis,  Compt.  rend.  135,  1106). 

Borimide  B,(NH),  is  a  spongy  white  mass 
insoluble  in  most  solvents.  On  heating  it  begins 
to  give  off  ammonia  at  125^-130°,  and  is  com- 
pletely transformed  into  boron  nitride  at 
slightly  higher  temperatures.  It  is  prepared  by 
heating  the  compound  of  boron  trisulpnide  and 
ammonia  B,S„6NH,  for  some  time  at  115°-120'' 
in  a  current  of  hydrogen  or  dry  ammonia  (Stock 
and  Blix,  Ber.  1901,  3039 ;  and  Joannis,  Compt. 
rend.  135,  1106). 

Boron  carbide  B^C  forms  exceedingly  hard 
shining  black  crystals,  which  are  capable  of 
polishmg  diamonds.  It  may  be  obtained 
massive  by  fusing  together  boric  oxide  and 
carbon  in  an  electric  resistance  furnace  and 
cooling  fairly  rapi^y  (E.  A.  Sperry,  U.S.  Pat. 
869114). 

Shaped  blocks  of  boron  carbide  are  obtained 
by  preparing  the  body  of  the  block  in  pure 
carbon,  emb^din^  this  in  powdered  carbide,  and 
firing  in  an  electric  furnace  (Boiling,  Eng.  Pat. 
6693,  1905).  Modifications  of  this  process  have 
also  been  patented  (Additions  (2)  Sept.  30, 
1904,  to  Fr.  Pat.  353017). 

Boron  nitride  BN  is  a  white,  amorphous, 
bulk^  powder  discovered  by  Balmain  in«1842. 
It  is  iniusible,  insoluble  in  water,  and  generally 
somewhat  inert  to  reagents,  but  Stock  and  Blix 
(Ber.  1901,  3039)  have  described  anpther  modifi- 
cation which  is  chemically  much  more  active. 
It  may  be  obtained  mixed  with  B^Os  by  burning 
boron  in  air ;  or  by  the  action  of  nitrogen  on  a 
mixture  of  boric  anhydride  and  carbon  heated 
to  redness  (Wohler  and  Deville,  Ann.  Chem. 
Phys.  [3]  52,  84).  It  may  be  prepared  by  the 
action  of  ammonium  chloride  vapour  pn  a 
porous  mass  of  calcium  phosphate  and  borax 
or  boric  oxide  heated  to  oright  redness,  after- 
wards extracting  the  cold  mass  with  hydro- 
chloric acid  and  water,  and  drying  the  residue 
of  BN  in  a  vacuum  desiccator  (Moeser  and 
Eidmann,  Ber.  1902,  535) ;  or  by  allowing 
boron  bromide  to  drop  into  liquid  ammonia, 
and  heating  the  precipitated  mixture  of  boramide 
and  borimide  to  750°  in  a  ounent  of  ammonia 


640 


BORON. 


ffas  (Stock  and  HoUe,  Ber.  1908,  2096) ;  or  by 
heating  boric  acid  and  calcium  eyaaamide.  A 
mixture  of  borocaloite  CaB^O,  and  carbon 
heated  to  ISSO**  and  then  to  1400'',  affoids  a 
theoretical  yield  of  boron  nitride  (Stabler  and 
Elbert,  Ber.  1913,  46,  2060).  B,N  has  been 
prepared  by  heatiii^  boric  acid  with  magnesium 
nitride. 

Boron  sulphide  B,8,  forms  fine  white  needles 
of  density  about  1*66,  which  melt  at  310°.  It 
is  volatile  in  hydrogen  without  decomposition 
(Moissan,  Compt.  rend.  116,  203).  It  may  be 
prepared  by  neatins  together  sulphur  and 
amorphous  boron  ( WOhler  and  De^e) ;  or, 
better,  by  heatine  ferroboron  in  a  stream  of  dry 
hydrogen  sulphide  at  400°,  and  purifying  the 
resulting  product  by  dissolving  out  the  sulphur 
with  carbon  dibulphide  (Hofmann,  Zeit.  angew. 
Ghem.  1906,  1362).  Combines  with  hydrogen 
sulphide  to  form  thiomeiaborie  acid  H^B^Sa.  Ib 
decomposed  by  carbon  dioxide. 

Boron  triflaorldo  BF,.  Amorphous  boron 
unites  with  fluorine  at  the  ordinary  temperature. 
It  is  a  gas  at  ordinary  temperatures,  and  may  be 
prepareid  by  heating  a  mixture  of  boron  trioxide 
and  calcium  fluonde  with  sulphuric  acid,  or 
a  mixture  of  potassium  borofluoride  and  boron 
sesquioxide  with  sidphuric  acid.  It  may  be 
liquefied  and  solidified  by  cold  and  pressure : 
melts  at  -127°  and  boils  at  -101°.  It  is 
rapidly  decomposed  by  water,  forming  hydro- 
fluoborio  and  boric  acids. 

Boron  trlehloride  BGl,  is  a  colourless,  very 
mobile,  refractive  liquid  which  fumes  in  the 
air.  Sp.gr.  1  -4338  at  0°  ;  m.p.  — 107°,  b.p.  12-5°. 
It  is  decomposed  by  water  with  formation  of 
hydrochloric  and  boric  acids.  It  is  prepared  by 
passing  dry  chlorine  over  amorphous  boron,  and 
coUectmg  the  vapours  in  a  U-tube  immersed  in 
•a  freezing  mixture.  The  product  is  purified  by 
shaking  with  mercury  to  remove  chlorine,  and 
by  fractionation.  It  may  also  be  prepared  by 
heatine  boron  sesquioxide  with  phosphorus 
pentachloride. 

Boron  tribromlde  BBr,  resembles  the 
chloride  in  physical  properties.  It  is  prepared 
in  the  same  way,  substituting  bromine  for 
chlorine,  or  by  treating  a  red-hot  mixture 
of  carbon  and  boric  oxide  with  bromine 
vapour.  M.p.  —46° ;  b.p.  90*6° ;  sp.gr.  2*66 
atO°. 

Boron  tri-lodlde  Big  may  be  obtained  by 
acting  on  heated  amorphous  boron  with  iodine 
or  hydriodio  acid,  or  by  treating  the  vapour  of 
the  trichloride  with  hydrogen  iodide.  It 
crystallises  in  colourless  nacreous  plates  and  is 
readilv  acted  upon  by  liffht.  M.p.  43°;b.p.  210°. 
Soluble  in  carbon  disulphide,  benzene,  and  other 
organic  solvents.  Bums  when  heated  in  oxvgen, 
and  is  decomposed  when  wanned  with  sulj^ur 
or  phosphorus. 

BOrIC  oxide  B^Oa  may  be  obtained  by  burning 
boron  in  oxygen,  or,  more  easily,  by  strongly 
heating  boric  acid,  when  it  melts  at  677°  to  a 
viscid  mass,  cooling  to  a  colourless  brittle  glass 
of  8p.gr.  1*88.  May  be  vaporised  in  vacuo,  and 
is  capable  of  expelling  carbonic,  nitric,  and 
sulphuric  acids  from  their  salts  at  a  red  heat. 
Somble  in  water,  forming  boric  acid.  For 
velocity  of  hydration  of  boric  oxide  to  metaboric 
acid  and  orthoboric  acid,  9m  Myers,  Ghem.  Soc. 
Trans.  1917,  111,  172. 


A  blue  glass,  '  boron-ultramarine,*  of  ooloar 
varying  with  the  duration  and  intensity  of 
heating,  and  with  the  proportions  of  the 
ingredients,  is  made  from  sodium  sulphide  and 
boric  anhydride.  It  is  stable  in  air  and  only 
slightly  soluble  in  water  (J.  Hoffmann,  Zeitsch. 
angew.  Ghem.  1906,  1089). 

Tetraboron  trioxide  B4O,,  horcn  dioxide 
BgO,,  and  ieirdboron  pentoxide  B4O,  are  ako 
known. 

Borle  or  Borade  aeld.  Sal  MdaHvum 
Hombergii,  Sal  narcotieym  vitrioli.  Boric  oxide 
forms  three  hydrates : 

Orthoboric  acid  B,0,-3HsO=H,BOa. 
Metaboric  acid  B,0,H,0=H,B,04. 
Pyroboric  acid  2B,0,-H,0=H,B40,. 

Ray  (Ghem.  Soc.  Trans.  1918,  803)  has  described 
the  mode  oi  formation  of  a  potassium  borate 
K2B4O.,  and  hence  the  existence  of  an  acid 
H,B40,. 

Bono  acid  appears  to  be  a  dibasic  acid,  and 
most  of  its  salts  may  be  regarded  as  derived  from 
metaboric  or  pyroborio  aoid.  Both  these  are  so- 
called  *  weak '  adds.  Their  salts,  when  aoluUep 
have  usually  an  alkaline  reaction,  'even  when 
containing  excess  of  borio  acid,  and  are  decom- 
posed even  bv  carbonic  acid. 

Boric  acid  is  found  free  in  nature  in  many 
voloanio  districts.  In  Oentral  Italy  it  is  pro- 
duced on  a  large  scale  in  the  territories  of 
four  communes :  Pomerance,  Maasa  Marittima, 
GasteL  Nuovo  di  Val  di  Gecina,  Montieri,  all 
in  the  province  of  Tuscany,  the  nearest  ahip- 

Eing  point  being  Leehom,  to  which  place  it  is 
rought  by  raiLroad  from  Volterra.  It  also 
occurs  in  the  extinct  crater  of  a  volcano  on 
one  of  the  Lipari  Islands,  and  in  the  crater 
of  Stromboli,  an  active  volcano  on  another 
island  of  the  sieime  group,  near  Sicilv.  Volcanic 
emanations  containing  boric  acid  occdr  in 
Nevada,  in  Galif omia,  and  Nova  Scotia.  It  exists 
in  solution  in  the  mineral  waters  of  Wiesbaden, 
Aachen,  and  Krankenlied,  in  Germany ;  in  the 
mud  volcanoes  of  the  Golorado  Desert,  in  San 
Diego  county,  Galifomia ;  in  the  water  of  several 
mineral  sprmgs  in  Tehama  county,  Galifomia. 
In  smaller  quantities  it  exists  in  sea  wat«r  and 
in  the  ash  of  many  plants. 

Saasolite,  or  Tuscan  boric  acid,  is  never 
produced  in  the  pure  state,  but  is  always  asso- 
ciated with  impurities,  both  soluble  and  in- 
soluble. It  differs  considerably  in  quality,  some 
parcels  containing  89  p.c.  of  crystalliaed  acid, 
while  others  yield  only  76  p.a  The  foQoWing 
analyses  show  its  genml  composition : — 

Analyses  of  crude  Tuscan  boric  acid. 
Boric  acid  Bfi^ 

I  hygroscopic 
Ammonium  sulphate  (NHJ2SO4 
Sulphate  of  alumina  and  iron 
Calcium  sulphate     . 
Magnesium  sulphate 
Sodium  sulphate 
Sodium  chloride 
Sand 
Sulphur 
Organic  matter 


.     47-96 

44-04 

:     37-00 

33-98 

.       0-73 

2-80 

»4      6-67 

1062 

n      013 

0-20 

.     trace 

1-20 

.       6-91 

4-03 

.      0-07 

110 

.      0-23 

0-32 

.      0-42 

0-80 

i — 

trace 

.      0-89 

0-91 

100-00 

100-00 

BORON. 


641 


An  aniklyBis  of  an  average  sample  taken  from 
5000  tons  flhowB  it  to  be  comf  osed  as  foUows  : — 

Crystamsed  bono  acid  BiO„2H,0  .      83-5 

HygroBCopio  water  .1-4 

Ammonium  sulphate 

Magnesium  sulphate 

Iron  and  alumina 

Sand,  organic  matter,  &o. 


5-3 
7-6 
0-3 

2-0 


100-0 

Boric  acid  occurs  on  the  West  Coast  of  South 
America,  principally  in  the  form  of  boronatro- 
oalcite  {tuexite^  or  hayenne),  and  is  found 
throuehout  the  pcoTince  of  Ataoama  and  in 
portions  of  Chile.  Ascotan  and  llKaricun^a, 
to  the  north  of  Copiapo,  are  the  places  which 
have  proved  most  successful  commercially. 
The  crude  material,  known  as  tha,  occurs  m 
both  places  in  lagoons  or  troughs ;  these,  instead 
of  bemg  entirely  filled  with  common  salt,  as  is 
usually  the  case  in  the  desert,  contain  zones  or 
layers  of  boronatrocaloite,  alternating  with 
layers  of  salt  and  salty  earth.  The  lagoons  of 
Maricunga  are  estimated  to  cover  3,000,000 
sq.  metres.  The  raw  material  contains  on  the 
average  about  26  p.c.  of  boric  acid,  but  by 
washing  and  calcination  it  ma^  be  raised  to 
65  or  60  p.c.  The  roughly  purified  boronatro- 
caloite is  shipped  to  Engluid  and  Germany. 

A  borate  of  lime  {rhodizite)  is  imported  from 
the  West  Coast  of  Africa. 

Pure  orthoboric  add  is  easily  obtained  by 
treating  a  solution  of  3  parts  borax  in  12  parts 
hot  water  with  1  part  sulphuric  acid.  On  cooling, 
boric  acid  separates  out ;  it  is  recrystallised  from 
hot  water,  dried  and  fused  to  expel  traces  of 
sulphuric  acid,  and  again  recrystalUsed  from 
water.  It  forms  white,  translucent,  monoclinic 
lamin»  (Kenngott),  which  have  a  mother-of- 
pearl  lustre  and  are  unctuous  to  the  touch. 
Sp.gr.  1-434  at  15°. 

Boric  acid  evaporates  freely  in  a  current 
of  steam.  The  loss  sustained  by  evaporating 
an  aqueous  solution  is  0-28  p.c.  of  the  water 
evaporated,  equal  to  2-8  lbs.  for  every  100 
gallons.  {CJ,  Nasini  and  Ageno  AttL  R. 
Accad.  dei  Lincei,  1912,  21,  U.  125.) 

The  solubilitv  of  boric  acid  in  water  has 
been  determined  by  Ditto  (Conrpt.  rend.  85, 
1060),  but  his  results  are  probably  low.  Herz 
and  Knoch  find  considerably  higher  values  at 
13°,  20°,  25°,  and  26°.  The  figures  of  Brandos 
and  Firnhaber  (Areh.  Pharm.  7,  50)  also  differ. 
The  results  obtiuned  by  Nasini  and  Ageno 
(Zeitsch.  physikal.  Chem.  1909,  69,  482)  are 
quoted  below : 


TMnpe- 
ratare 

Orams  of  H,BOs 

per  100-gram 

solution. 

Tempe- 
rature 

Grams  of  H,BO, 

per  100-gram 

solutloD 

0° 

12-2° 
21° 
31° 

40° 
50° 

2-59 
3-69 
4-90 
6-44 
8-02 
10-35 

60° 
69-6° 
;     80° 
90° 
99'4>° 

12-90 
15-58 
1911 
23-30 
2810 

C/.  Nasini  and  Ageno  (GassetU,  1911, 41,  i.  141). 

The  solubility  of  orthoboric  acid  in  water  is 

low oned    (not,    as    stated    in    various    places, 

increased)  by  the  presence  of  hydrochlonc  acid 

Vol.  I.— r. 


(Herz,  Chem.  Zentr.  1903,  i.  312)  and  of  sul- 
phuric, nitric,  and  acetic  acids ;  but  tartaric  and 
oxalic  acids  have  the  opposite  effect  {ibid.  755). 
Boric  acid  is  soluble  in  alcohol,  glaioial  acetic 
acid,  and  volatile  oils.  A  cold  saturated  aqueous 
solution  colours  litmus  a  wine-red;  a  hot 
saturated  solution  g^ves  a  briffht-red  colour. 

Crystallised  boric  acid,  heated  to  100°,  is 
converted  into  H^,04  (Schaffgotsch,  J.  1859, 
71),  and  into  Ufifl^  at  160°  (Merz,  J.  pr.  Chem. 
99,  179;  Ebehnen  and  Bouquet,  Ann.  Chim. 
Phys.  [3]  17,  63).  At  a  stronger  heat  the  acid 
froths  up,  parting  with  its  water  and  forming 
boric  anhyoride  as  a  fused  viscid  mass,  solidify- 
ing to  a  fissured  glass  on  cooling.  For  the  action 
of  boric  acid  on  sodium  chlonde  on  heating,  sec 
Levi  and  Castellani  (Gazz.  chim.  ital.  1910,  40,  i. 
138) ;  Levi  and  Garavini  {ibid.  191 1.  41,  i.  756). 

Boric  acid  and  its  salts  are  extensively  used  in 
medicine  as    an   antiseptic;    and  as  a  food 

Ervative  they  are  also  very  widely  employed, 
are  also  employed  for  glazins  porcelain  and 
enware,in  the  preparation  of  glass  and  certain 
pigments,  in  the  manutaoture  of  cosmetics,  soaps, 
m  the  Unings  of  safes,  in  the  elazing  of  paper,  for 
dressing  leather,  as  a  flux,  b^  laundrrases,  and 
for  soakinff  the  wicks  of  steann  candles. 

The  efitect  of  boric  acid  in  glazes  is  to  increase 
their  hardness  and  their  f usifauity,  and  to  modify 
the  coefiioient  of  expansion.  A  small  amount  of 
boric  acid  lowers  tne  expansion,  whilst  a  large 
quantity  produces  an  increase.  This  effect  is 
explained  ov  Grenet  (Compt.  rend.  123,  891)  to 
be  due  to  the  fact  that  when  the  proportion  of 
bases  to  boric  acid  is  high,  devitrification  occurs, 
whilst  when  the  boric  acid  is  the  more  important 
constituent,  the  coefficient  of  expansion  tends 
to  approximate  to  that  of  bone  add  itself, 
which  is  higher  than  that  of  any  glass. 

It  has  also  been  proposed  to  use  boric  acid 
in  the  preparation  of  nitric  acid  from  Chile 
saltoetre,  so  as  to  obtain  borax  as  a  by-product. 

udastrlal  extraetton  of  boric  aeid.  The 
occurrence  of  the  sal  sedativum  of  Homberg  in 
the  water  of  the  Tuscan  lagoons  appears  to  have 
been  first  noticed  in  1777  by  H6fer,  a  Florentine 
apothecary,  and  its  extraction  was  beeun  about 
1815,  and  to-day  a  laise  part  of  the  Doric  acid 
of  commerce  is  derived  from  the  lagoons  near 
Monto  Rotondo,  Lago  Zolforeo,  Sasso,  and 
Laiderello,  in  the  Maremma  of  Tuscanv»  inclosing 
both  natural  and  artificial  vents,  ihe  soffioni 
or  jets  of  steam,  which  often  rise  in  thick  columns 
to  a  considerable  height,  contain  only  traces  of 
boric  acid,  but  when  these  are  condensed  iif  the 
water  of  the  lagoons  this  becomes  gradually 
chaiged  with  the  acid  which  is  obtamed  from 
the  solution  by  evaporation. 

To  obtain  the  Doric  acid,  the  soffioni  are 
surrounded  by  basins  of  rough  masonry,  several 
of  which  are  arranged  in  steps,  one  above  the 
other,  in  such  manner  that  the  contents  of  each 
basin  can  be  led  by  ffravitetion  into  the  basin 
below.  Fresh  water  m>m  a  neighbouring  spring 
is  conducted  into  the  uppermost  basin,  whilst 
the  gases  and  vapours  of  the  fumaroles  rise 
through  the  water  from  beneath  oceadonally 
with  such  violence  as  to  eject  the  water  to  a 
height  of  several  feet.  After  twenty-four  hours 
the  water  in  the  first  basin,  which  is  generally 
muddy,  is  allowed  to  pass  into  the  second  bctfin, 
the  first  being  recharged  with  fresh  water.   After 

2t 


642 


BORON. 


another  twenty- four  hours  the  second  basin  is 
discharged  into  the  third  and  the  first  into  the 
second,  the  second  and  following  basins  being 
also  built  round  soffioni.  After  naving  passed 
through  four  or  five  of  these  basins,  the  solution 
is  passed  into  rectangular  reservoirs  in  which 
the  suspended  matter  is  deposited  on  standing. 
From  these  it  passes  into  a  series  of  leaden 
evaporating  pans,  placed  in  couples  one  above 
the  other  in  the  form  of  a  terrace.  These  pans 
are  heated  by  the  gases  and  vapours  of  soffioni 
which,  on  account  of  their  situation,  are  other- 
wise useless — by  a  method  first  adopted  by 
Count  Lardarel  in  1815.  The  evaporatmg  pans 
are  square,  about  1  foot  deep  and  9  feet  square, 
and  are  supported  on  wooden  beams.  The  solu- 
tion is  heated  in  these  for  twenty-four  hours 
until  it  has  attained  a  density  of  IK)!?,  when  it 
is  decanted  into  a  second  series  of  pans,  where, 
after  another  twenty-four  hours,  it  attains  a 
density  of  1*034,  and  is  finally  decanted  into  the 
last  four  pans,  where  it  is  evaporated  to  a  specific 
gravity  of  1-07. 

The  temperature  gradually  increases,  being 
in  the  first  pans  about  60**  to  70^.  in  the  following 
pans  about  75^  and  in  the  last  as  high  as  80*. 

In  all  these  pans  a  precipitation  of  gypsum 
takes  place,  which  requues  to  be  removed  from 
time  to  time.  When  the  solution  in  the  last 
pans  has  attained  a  density  of  107,  it  is  run 
through  funnels  into  the  crystallising  vats,  con- 
sisting of  wooden  tubs  lined  with  tead.  After 
twenty-four  hours  the  crystallisation  is  complete, 
the  mother  liquor  is  then  decanted  on  and 
added  to  the  evaporating  pans  a  few  hours 
before  the  completion  of  the  concentration.  The 
crystals  are  drained  in  baskets  placed  under  the 
crystallising  vats  for  twentv-four  hours,  and  are 
spread  out  on  the  bottom  of  a  large  drying  oven, 
which  is  likewise  heated  by  the  vapour  from 
the  soffioni.  The  layer  of  crystals,  which  is  two 
or  three  inches  thick,  is  stirred  at  intervals  to 
assist  the  drying,  lliis  is  complete  in.  twenty- 
four  hours.  An  improved  form  of  evaporating 
apparatus  consists  in^  decanting  the  solution  in 
the  reservoirs  from  which  the  suspended  matter 
has  deposited  into  a  pan,  and  thence  running  it 
into  a  slightly  inclined  trough  made  of  sheet 
lead  with  the  edses  tum^  upwards.  The 
troueh  has  an  unduLitory  form,  is  supported  on 
wooden  sleepers,  and  neated  b;|^  tne  soffioni 
vapours,  llie  solution  of  boric  acid,  after 
passing  through  this  heated  trough,  becomes  so 
concentrated  as  to  be  ready  for  crystallisation. 

Artificial  soffioni  have  been  bored  to  a  depth 
of  200  feet  in  the  vicinitv  of  the  Monte  Botondo. 
.  The  chief  works  are  at  Monte  Gerboli,  Larderello, 
San  Federigo,  Castel  Nuovo,  Sasso,  Monte 
Botondo,  Lustignano,  Serranzano,  Lago,  and 
San  Eduardo,  each  of  which  has  from  8  to  35 
lagoni,  100  to  200  feet  in  diameter  (Payen, 
Ind.  Chem.  transl.  by  Paul). 

The  boric  add  thus  obtained  is  far  from 
pure.  Analyses  of  different  samples  by  Payen, 
Vohl,  and  Wittstein  show  that  it  contains  from 
74  to  80  p.c.  crystallised  boric  acid,  from  4*5  to  7 
p.c.  of  hygroscopic  water,  ammonium  and  mag- 
nesium sulphates  8-14  p.c.,  together  witn 
gypsum,  day,  sand,  sulphur,  organic  matter, 
and  free  acids  and  ammonia. 

The  origin  of  the  boric  add  in  the  soffioni 
IB  not  understood.    Dumas  suggested  that  it  is 


formed  by  the  decomposition  by  means  of  water 
of  a  bed  of  boron  sulphide  formed  at  some 
depth  bdow  the  surface.  BoUey  (Annalen« 
68,  122)  supposed  that  it  is  produced  bv  the 
action  of  a  not  solution  of  ammonium  chloride 
upon  the  borates  contained  in  the  earth.  Accord- 
ing to  Warington  (Chem.  Gazette,  1854,  419), 
mhler  and  l)eville  (Annalen,  105,  69),  and 
Popp  (Annalen,  SuppL  8,  1),  its  formation  is 
probably  due  to  the  action  of  water  upon  boron 
nitride. 

Dieulafait  has  found  boric  acid  in  regions 
'where  there  are  no  visible  manifestations  of 
volcanic  action,  and  concludes  that  it  is  of 
aqueous  origin,  and  derived  from  the  waters 
of  ancient  seas  (Compt.  rend.  100,  1017,  and 
1240). 

Of  late  years  the  importation  of  boraoite 
from  South  America  and  oolemanite  from 
Oalifomia,  and  also  some  Persian  ores,  has  had 
a  considerable  effect  on  the  Italian  industry. 
Besides  the  obvious  method  of  separating  the 
boric  acid  from  these  ores  by  addification  and 
crystallisation,  other  processes  are  used  for  its 
extraction.  ^ 

One  process  consists  in  grinding  the  borate 
of  lime  or  ulexite  to  an  im^pable  powder  and 
treating  it  with  sulphurous  acid^ 

A  large  wrought-iron  tank,  circular  in  shape 
and  eg^-ended,  is  lined  with  stout  sheet  lead ;  it 
is  provided  with  a  cover  and  still  head,  mechani- 
cal agitator,  and  steam  pipes.  It  is  first  of 
all  charged  about  half  full  witii  water  or  weak 
liquor  from  a  previous  operation.  The  liquor  is 
then  boiled,  and  the  powdraed  borate  fed  in  by 
means  of  an  Arohimedean  screw. 

Sulphur  is  then  burnt  in  an  adjoining  fomaoe, 
and  the  sulphurous  gas  is  injected  by  means  of 
a  peculiarly  constructed  lead  injector  into  the 
boiling  liquor.  A  special  type  of  sulphur  burner 
for  tms  process  is  patentea  by  the  American 
Borax  Co.  (U.S.  Pat.  809650,  1906).  The  gas 
is  wholly  absorbed  by  the  calcium  borate, 
which  itself  is  slightly  soluble  in  water,  boric 
acid  and  calcium  sulphite  bein^  formed.  The 
steam  arising  from  the  operation,  oontaininf 
boric  acid  vapours,  passes  from  the  still  held 
through  a  condenser  in  order  to  {wevent  any 
loss  that  would  occur.  When  the  operation  is 
complete,  the  steam  and  gas  are  shut  off,  and 
the  contents  of  the  pan  allowed  to  settle,  which 
occupies  about  ten  hours.  The  dear  boric 
acid  liquor  is  then  run  dther  into  vats  made 
from  white  sugar  pine,  or  of  ordinary  wood 
lead-lined,  where  the  boric  add  crystallises 
out.  The  -  mother  liquors  are  then  dAwn  off, 
to  be  used  over  again  if  not  too  highly  impreg- 
nated with  foreign  salts,  or  still  further  treated 
for  the  recovery  of  the  calcium  sulphite  and  the 
slight  percentage  of  boric  acid  thev  contain. 

Bigot  (J.  Soc.  Chem.  Ind.  1899, 330)  obtahis  it 
by  heating  together  borate  of  caldum  and  ammo- 
nium siUmiate  in  a  closed  veoseL  The  ammonia 
driven  off  is  condensed  and  collected,  and  the 
boric  add  obtained  by  extraction  of  the  reddae. 

Another  method  is  to  treat  boracite  with 
sodium  bisulphate,  a  by-product  in  nitric  add 
manufacture.  The  two  are  dissolved  in  theo- 
retical quantities  in  water  to  a  dendty  of  15°  B.  at 
100".  The  solution  is  filtered  and  ooncentitated 
to  30°  B.  On  cooling,  the  boric  acid  crystalliaeB 
out  and  very  pure  sodium  sulphate  is  obtained 


BORON. 


643 


by  concentration  of  the  mother  liquors  (Heidl- 

bers.  Chem.  Zeit.  1907, 31,  Rep.  48). 

Chenal  Douilhet  &  Co.  (D.  R.  P.  110421, 
1899)  produce  boric  acid  by  taking  advantage 
of  the  fact  that  when  a  borate  ia  boiled  with 
ammonium  chloride,  ammonia  and  boric  acid 
are  jnoduced.  If  the  concentration  is  too  high, 
there  is  a  tendency  to  recombination ;  the 
boric  acid  is  therefore  removed  frequently  by 
crystallisation  from  portions  of  the  liquid,  the 
mother  liquors  being  returned  to  the  main  volume. 
By  this  process  it  is  claimed  that  98-99  p.0.  of 
the  boric  acid  in  combination  is  recovered. 

In  another  process  chlorine  is  passed  into 
water  at  70^  containing  finely  powdered  calcium 
borate  in  suspension.  Calcium  chloride  and  chlo* 
rate  and  boric  acid  are  produced*  The  boric  acid 
is  removed  by  cooling,  and  the  mother  liquors 
used  acain  until  sufficiently  concentrated  for 
convenient  extraction  of  the  chlorate  (0.  0. 
Moore,  E!ng.  Pat.  20384,  1899). 

MSTALUO   BOSATKS. 

Borates  are  obtained  by  the  action  of  boric 
acid  on  metaUio  oxides  or  their  salts,  in  either 
the  dry  or  wet  way. 

In  solution  boric  acid  is  a  verv  weak  acid, 
being  expelled  by  almost  all  acids  from  its  com- 
binations, partiaUy  so  even  by  carbonic  and 
hydrosulphurio  acids.  A  boiling  concentrated 
solution,  however,  decomposes  carbonates  and 
soluble  sulphides  and  manganese  sulphide. 

In  the  dry  way,  at  high  temperatures,  it  is 
capable  of  decomposing  the  salts  of  all  more 
volatile  acids. 

Alkaline  borates  are  soluble  in  water,  but 
aro  precipitated  by  alcohol.  The  remaining 
borates  are  insoluble,  or  very  sparingly  soluble 
in  water.  The  soluble  borates  produce  precipi- 
tfbtes  in  solutions  of  salts  of  calcium,  barium, 
strontium,  nickel,  and  cobalt,  and  of  ferric  salts 
which  are  readily  soluble  in  ammonium  chloride. 

Anhydrous  borates  are  produced  by  fusing 
together,  in  a  special  furnace  at  1350°- 140^ 
for  three  hours,  Doric  oxide  with  the  necessary 
quantity  of  oxide,  carbonate,  or  nitrate  of  the 
metal.  With  large  excess  of  boric  acid,  lithium, 
potassium,  sodium,  rubidium,  caesium,  thallium, 
and  silver  produce  clear  fusions  which  either 
cr^tallise  or  leave  clear  glasses  on  cooling. 
Cuprous  oxide,  and  oxides  of  lead,  bismuth, 
antimony,  arsenic,  titanium,  molybdenum,  and 
tungsten   produce   clear   fusions    at   the   high 


temperatures  which  form  emulsions  on  cooling. 
The  oxides  of  calcium,  strontium,  barium, 
magnesium,  zinc,  cadmium,  maoffanese,  iron, 
cobalt,  and  nickel,  do  not  give  homogeneous 
fusions,  but  separate  into  two  layers  ( W.  Guertler, 
J.  Soc.  Chem.  Ind.  1908,  168). 

Borates  have  also  been  prepared  eleotrolyti- 
cally  by  Levi  and  Castellani  by  electrolysing  boric 
acid  and  an  alkaline  earth  chloride  in  a  special 
type  of  divided  cell  (J.  Soc.  Chem.  Ind.  1909, 248). 

Ammonium  borates.    LadereaUe 

(NH4),BioO„.6H,0 
occurs  in  the  Tuscan  lagoons  in  small  crystal- 
line rhomboidal  plates  (D*Achiardi,  Chem.  Soc. 
Abetr.  1900,  600).  Atterberg  (Zeitseh.  anorg. 
Chem.  1906,  48,  367)  distinguishes  a  diborate 
(NH4),B«07,6H,0,  crystalliamg  in  tetragonal 
pyramids,  besides  the  perUaborcUe 

(NH4),0,6B,0„3H,0, 
orystalliaing  in  rhombic  double  pyramids  pre- 
viously prepared  by  Rammelsberg.    Cf,  Sboxgi 
(Atti  R.  Accad.  dei  Linoei,  1912,  21,  ii.  855 ; 
1913,  22,  L  90). 

Barimn  bontes.  The  interaction  of  barium 
hydroxide  and  boric  acid  in  aqueous  solution  has 
been  studied  by  Sborgi  (Atti  R.  Accad.  dei 
Lined,  1914,  23,  i.  530,  717,  854).  The  only 
stable  compounds  which  appear  to  exist  aro  the 
triborates  (Ba0,3B,0„+Ht0)  and  the  meta- 
borate  (Ba0,B,0,4-H^). 

Caletun  borates  Ca^«0,i.  Thero  aro  three 
varieties  of  calcium  borate,  which  correspond  to 
the  three  varieties  of  calcium  carbonate,  calo 
spar,  marble,  and  chalk — viz.  horaeiit  or  pandet- 
mite,  eoUmanitef  and  prieite'—etLoh.  found  in 
difFerent  parts  of  the  world  in  large  quantities, 
and  of  a  well-defined  and  constant  composition. 
Meyerhoffer  and  van  't  Hoff  (Annalen,  351,  100), 
in  attempting  to  inreparo  compounds  of  similar 
composition  artificially,  have  obtained  several 
other  calcium  borates.  These  authors  assign 
different  compositions  to  colemanite  and  pander- 
mite.  Boraette,  in  outward  appearance,  closely 
resembles  a  snow-white,  fine-grained  marble; 
cciemanite  is  of  a  crystalline  naturo  like  calc  spar, 
or  Iceland  spar,  and  has  been  termed  borate 
spar ;  pricUe^  6r  hechiUU,  is  a  very  fine,  whiter 
soft,  chalky  mineral  of  a  cohesive  naturo,  easily 
rubbed  to  powder,  and  resembling  chalk. 
Chemically  speaking,  they  aro  all  hydrated 
calcium  borates,  differing  only  in  their  composi- 
tion in  respect  to  the  water  of  combination, 
their  composition  being  given  in  table  below. 


• 

C»iBtOii,8Aq. 

Ga,B,0ii,4AQ. 

Ca|B,0ii,SA4. 

CasB,Oi,.SAq. 

Boric  acid  B«0a 

limeCaO        .... 

Water  H,0      .... 

55-8 
300 
14-2 

53*3 
28-4 
18-3 

50-9 
27-2 
21-9 

48-8 
261 
251 

100-0 

100-0 

1000 

100-0 

Cf.  Sborgi  (Atti  R.  Accad.  dei  Lincei,  1913, 22, 
i.  639,  715). 

Boracite  has  been  extensively  mined  at 
Sultan-Chairi,  in  the  district  of  the  Villayet  of 
Brousa  in  Asia  Biinor,  forty-five  miles  from 
Panderma,  a  port  on  the  Sea  of  Marmora ;  the 
principal  deposits,  as  far  as  yet  known,  exist 


near  the  Tschataldga  Mountain,  in  long.  28*^  2' 
east  of  Greenwich  and  lat  40°  norui.  The 
Susurlu  river  runs  from  the  Tschataldga  Moun- 
tain to  the  Sea  of  Marmora :  it  is  partly  navi- 
gated to  a  point  called  Mohalitch ;  the  field  is 
situated  in  a  basin  of  Tertiary  age,  surrounded 
by  volcanic  rocks,  which  vary  from  granite  on 


644 


BORON. 


the  east  to  trachyte  on  the  north,  and  oolunmar 
basalt  on  tiie  west.  Several  basaltic  hills  and 
dykes  protrude  in  different  portions  of  the  basin, 
and  the  presence  of  hot  and  mineral  springs 
further  testifies  to  the  volcanic  influences  whi% 
have  been  at  work,  and  in  which,  doubtless, 
originated  the  boraoio  mineral.  The  latter 
occurs  in  a  stratum  at  the  bottom  of  an  enormous 
bed  of  ^psum  |  its  greater  sp.gr.  probably  im- 
pelling it  downwards,  while  the  whole  mass  was 
yet  in  a  soft  state.  Several  feet  of  day  cover 
the  gypsum  bed,  which  is  here  60  or  70  feet  thick, 
though  in  places  it  attains  to  double  that  thick- 
ness. The  borate  strata  vary  in  depth,  and  have 
been  proved  for  a  vertical  distance  of  46  feet. 
The  mineral  ezivts  in  closely  packed  nodules  of 
very  irregular  size  and  shape,  and  of  all  weights 
up  to  a  ton.  It  is  easily  separated  from  the 
dark-coloured  gypsum  in  which  it  ia  embedded, 
and  a  number  of  people  are  employed  at  the  pit 
mouth  in  picking  and  selecting  the  material.  It 
is  sold  on  a  basis  of  40  p.c  boric  acid,  which 
would  be  equal  to  78-5  p.c.  of  the  pure  calcium 
borate  with  five  molecules  of  waterCasB.Oi  j  >6Aq., 
the  remainder  consisting  of  calcium  sulphate  and 
other  impurities. 

Boraie  war  or  coUmanite  has  been  exten- 
sively mined  since  1883  at  Calico,  in  San  Ber- 


nardino county,  California,  462  miles  south-east 
of  San  Franoisoo.  The  geological  formation 
of  the  surrounding  hills  oonsists  of  black  Uva, 
sandstones  of  different  colours,  gypsum,  steatite, 
and  calcium  carbonate ;  it  is  found  in  veins  and 
seams  from  2  feet  to  8  feet  in  thickness,  in  some 
cases  dipping  at  an  angle  of  36%  and  at  others 
running  into  the  hillsides  almost  horizontally. 
Its  colour  and  streak  is  white-milky  to  tnns* 
parent ;  hardness  3*5-4  ;  8p.gr.  2*4 ;  before  the 
blowpipe  it  exfoliates,  decrepitates  violently,  and 
melts  imperfectly  after  considerable  heating ; 
it  imparts  a  redoish-yellow  colour  to  the  flame, 
which  changes  to  green.  The  fiagmenta  are 
obscurely  niombic  and  pulverise  easfly;  it 
is  wholly  soluble  in  hot  hydrochloric  acid ' 
from  the  solution  boric  acid  crystallises  oo 
cooling.  Lustre  of  the  mineral  is  vitreous  to 
adamantine.  The  veins  and  seams  are  inter- 
spersed with  masses  of  calcium  carbonate  and 
magnesium  silicate,  from  which,  like  the  bora- 
cite,  it  has  to  be  picked  and  selected. 

Its  formula  is  CajB^O^i^SAq. ;  it  is  sold  on  the 
basis  of  40  p.c.  boric  acid.  Average  samjples 
from  the  buDc  vary  in  composition  from  33-8 
p.a  boric  acid  up  to  41*2  p.c. ;  the  foUowing 
analyses  may  serve  as  examples  of  the  generu 
composition : — 


BoBATB  Sfab. 


Component  parts 

1 

2 

S 

4 

ft 

^Calcium  borate  Ca.BeOf  (5 Aq.  . 
Calcium  carbonate  CaCOg 
Insoluble  matter  SiOj 
Remaining  impurities  MgO,  &o. 

66*2 

16*3 

10*5 

7-0 

70-4 

161 

10-2 

4-3 

75-0 

11-6 

8*9 

4*5 

78-00 
8-76 
7-10 
6-15 

80-80 
717 
7*60 
4-43 

— 

100-0 

100*0 

lOOH) 

100-00 

100*00 

•=  to  boric  acid        •         .         •         • 

33-8  p.c. 

35-9  p.c. 

38*2  p.c. 

39-8  p.c. 

41-2  p.c. 

Borate  spar  is  also  found  in  the  neighbourhood 
of  Furnace  Creek,  Inyo  county,  California ;  its 
outward  appearance  is  frequently  so  exactly 
like  calc  spar  as  often  to  be  mistaken  for  that 
mineral.  Friceite  has  hitherto  not  been  so  ex- 
tensivdv  mined  as  boracite  and  colemanite ;  a 
mine  of  this  mineral,  however,  exists  at  Lone 
Ranch,  Cheteo,  Curry,  county  Oregon,  from 
wiuch  source,  since  the  first  cargo  was  extractea 
by  £.  L.  Fleming  in  1888,  several  hundred  tons 
have  been  taken.  It  is  found  embedded  in 
boulders  of  dlffernit  size,  the  nodules  varying  in 
weight  up  to  one  ton.  It  is  of  a  soft  chSky 
nature,  purely  white,  oan  be  easily  rubbed  to 
powder,  but  is  of  a  cohesive  character;  it  is 
very  soluble  in  sulphurous  acid,  hydrochloric 
acid,  or  acetic  acid,  yidding  boric  acid.  The 
following  analysis  from  bulk  shows  its  composi- 
tion: — 

Boric  acid  B,0,       .         .         .     44-24 


Lime  CaO 
Water  H,0  . 
Magnesia  HgO 
Silica  SiO,      . 


30-91 

23-00 

0-65 

1-20 


Its  composition  is  represented  by  the  formula 
CaB^O^SHjO. 

BoronatrocalcUe.  Ulexite,  Hxa,  eaUonbalU^ 
hayesine  Ca|B,OiiNa,B40.,16HaO,  is  a  soft, 
fibrous,  silky  mineral  of  a  brilliant  white  when 
pure,  generally  found  in  nodules  of  a  yellowish- 
white  colour,  varying  in  size  from  that  of  a 
Brazil  nut  to  a  potato.  This  curious  mineral  was 
first  found  in  the  nitre  beds  of  P^ru  in  small 

Suantities,  and  was  examined  by  Ulex  in  1836. 
t  was  discovered  .in  Taiapaoa,  30  miles  from 
Iquique,  under  the  crust  that  covers  the  nitimte 
of  soda  beds.  It  has  since  been  discovered  in 
Chile,  Bolivia,  Cslifomia,  Nevada,  Nova  Sootiay 
and  Persia. 

Its  composition  is  constant,  containing, 
pure: 

Boric  acid  B|0,         •         •         •  43*1 

lime  CaO          ....  13-8 

SodaNa,0        .         •         .         •  7-7 

Water  H,0       ....  35-4 


100-0 


100  00 
Beehilite  is  a  calcium  borate  found  in  the 
lagoons  in  Tuscany. 


The  nodules  are  frequently  found  incrusted 
with  a  coating  'of  sodiunt  sulphate  and  salt, 
from  which  cause  the  percenti^ge  of  boric  aoid 
in  large  parcels  varies  considerably,  tho  avenge 
being  from  18  to  26  p.c. 


BORON. 


046 


Chile  hfts  hitherto  been  the  principal  Bonrce 


It  18  also  found  in  nodules  in  jrey  limestone 
of  supply  of  this  borax  material.'    Ulezite,  when  '  at  Werksthal,  Hungary,  and  at  Danbuzy,  Oon- 


in  a  state  of  fine  division,  is  difficultly  soluble  in 
boiling  water. 

cScium     horosaieaU,       DoUiiU    {Howlitt). 


nectiout»  United  States* 

8uu€xiU  is  a  hydrated  borate  of  manganese 
and  magnesia  found  in  Sussex   county.  New 


A  siliceous  borate  of  Ume,  colour  white,  streak  i  Jersey,  United  States.  Towmalint^  found  in 
white,  opaque,  of  a  chaUcy  nature,  found  at  I  different  parts  of  the  world  in  different  colours. 
Calico,  SanBemardino  counW,  Cahfomla,  anu  also  contains  a  small  percentage  of  boiio 
at  Brookville,  Nova  Scotia.    Composition : 

Boric  acid  B,0,       .         .         .  44*22 

LimeCaO        ....  28*09 

SQioaSiO,       ....  15-25 

Water  H,0     ....  11-84 


lOOOO 


acid. 

Potassium  bontss.  Atterberg  distingoishes 
five  difierentpotassium  borates :  a  monoborate 
K,0,B,0„3]^0 ;  three  diboratee  K,0,2B20i 
crystallising  with  4,  51,  and  6  molecules  of 
water  respectively ;  and  Laurent's  pentaborate 
KtO,5B,0„8HaO  (Zeitsoh.  anorg.  Chem.  190G, 
867). 


?*fP"v**'?*^.  *■  T^^  ?^^  ^^  ^J?"^^  I  Sodtam  bontsi.  The  only  commercially 
a  soluble  borate  m  solution  wrtJi  cc^pw  oUonde  ^  i^^  compounds    are    sodium    diborate 

or  sulphate.    It  is  blue,  and  used  m  certam  ^^    ^^,^j  ^^  ^^^  perborate  (v,   PerhoraUs), 
oil  oamts  and  also  m  the  oolourmg  of  poreelam.  rj^^^  meUboiate  NaB0„4H,0  is  leadUy  obtained 

Iron  ■»'«8*.^A^**Jg»*«d.  »»»*•  of  «;on,  ^y  fusing  together  the  necessary  proportions  of 
laganiie  Fe,0„3B,0„3H,0,  is  found  m  the  ^^^j  ^  ^^^  sodium  carbonate,  and  cr3'stal. 
Tuscan  lagoons.  liaing. 

Uad  bontss.  By  mixing  concentrated  ^^id  borates  Na,0-3B,0,  and  Na,0,4B,0, 
solutions  of  lead  nitrate  and  borax,  the  meU-  melting  at  6d4**  and  783**  respectively  may  be 
borate  Pb(BO,),,H,0  is  preoipiUted,  and  by  obtained  by  fusing  mixtures  of  borax  and  boron 
the  use  of  solutions  of  smaller  concentrations  trioxide. 

Rose  obUined  many  basic  salts.    Thev  all  melt        Sodium  diborate^  or  Borax,    Borax  occurs  in 
on  strong  heating  to  colourless  or  light-yeUow,  ^^^  crude    state   in   what  are   termed    borax 


highly  retractive  glasses,  the  hardness  increasing 
with  the  boron  content.  Glasses  may  be  ob- 
tsined  by  fusing  together  lead  oxide  and  boric 
acid  in   any  proportions   greater  than  0'0725 


marshes,  which  are  generally  the  bottoms  of 
dried-up  Ukes,  or,  where  tincal  is  found,  Iskes 
that  are  neariy  dried.  The  crude  borax  in  the 
former  instances  is  found  lying  on  the  surface 


equivalent  of  PbO  to  1  equivalent  B,0„  but  ^j    ^^    ^^^^    of    a    peculiar   greyish-yellow 
below  this  limit  an  emulsion  is  fomed  on  cooling,    colour,  having  a  depth  of  from  1  inch  to  18 

r^  '^^^^  ^!^  J!?f?J^  inches.    It  iifgenerilly  associated  with  other 

""    '""     substances,  both  soluble  and  insoluble,  as  the 
table  of  anslyses  below  shows. 


This  mineral  occurs  crystalline  and  massive, 
colour  white,  streak  white,,  fracture  conchoidal 
uneven,  subtransparent,  translucent,  lustre 
vitreous  inclining  to  adamantine,  haidness  7, 


At  Jagadhri   in  Northern   India,  37  miles 
S.E.  of  Umballa,  there  is  a  borax  refinery,  the 


sp.Kr.  2-83.  Pyrojelectric,  soluble  in  acids.  It  ^^^  ^  ^j^^^  j,  ^^  ^  Caleutta.  The 
js  found  sA  Stossfurt,  Prussia,  embedded  m  the  |  ^^^y  of  tincal  and  Vrax  obtained  from 
kamite  beds,  the  composition  being  t  ,  IV  ^    j^rL:^^.    ^4    *\.^    tt:m.u«.»    M/^....f^;». 


beds,  the  composition  being 

Boric  acid  B,0,       .                  .  62-33 

Magnesia  ligO                            .  27-03 

Chlorine  a      ....  7-91 

Magnesium  Mg                          .  2-73 


100-00 
Composition  ot  Cbuds  Bokax  r£oM  tub  &ABSHi:st 


the  districts  of  the  Himalayan  Mountains 
amounts  to  about  2000  tons  per  annum.  Tl.e 
!  tincal  deposits  are  of  very  ancient  origin. 
In  North  America  there  are  no  less  than  ten 
deposits,  five  of  them  being  in  the  State  of 
California — at  Saline  Valley,  Furnace  Creek,  and 
Armagora  (in  Inyo  county),  Slate  Range  (in  San 


Sodium  biborate 
Water      .         ,         .         . 
Sand  and  insoluble  matter 
Sodium  carbonate 
Scdium  sulphate 
Sodium  chloride 
Calcium  carbonate 
Magnesium  carbonate 
Oxide  of  iron  and  alumina 


1 

S 

8 

4 

5 

s 

7 

8 

30-30 

38-3 

2-10 

53-08 

1-0 

33-30 

6-52 

45-20 

37*68 

40-8 

14-08 

30-24 

25-7 

25-88 

16-46 

43-80 

18-00 

10-0 

12-80 

1-20 

33-0 

2-40 

8-80 

7-15 

6-10 

5-3 

16-10 

5-50 

34-3 

13-70 

18-30 

2-75 

0-26 

01 

1910 

0-35 

0-5 

8-25 

20-22 

— . 

0-50 

0-4 

34-60 

0-50 

0-7 

15-40 

28-20 

0-40 

3-28 

2-4 

0-70 

.— . 

2-0 

0-60 

0-80 

0-30 

2-26 

0-4 

0-30 

-~ 

0-6 

0-30 

0-50 

0-30 

1-62 

1-4 

0-22 

013 

1-3 

0-17 

0-20 

0-10 

100-00 

100-0 

100-00 

100-00 

1000 

100-00 

100-00 

100-00 

Bernardino  county),  and  Lower  Lake  (in  Lake 
county);  the  remaining  five  are  in  the  State  of 
Nevada-— at  Rhodes,  Teels  Marsh,  Columbus, 
and  Fish  Lake  (in  Esmeralda  county),  and  Salt 
Wells  (Carson  Lake,  Churchill  county). 

Borax  was  first  accidentally  discovered  in 


I  California,  in  1856,  by  Dr.  John  A.  Veatch,  since 
:  which  time  the  different  deposits  mentioned 
•  have  been  developed,  and  the  available  supply 
'  is  practically  unhmited,  and  is  solelv  regulated 
by  the  demand.  The  exports  of  borax  from 
iLxnerica  have  increased  very  greatly  of  Ute 


646' 


BORON. 


yeaxB,  and»  to  a  large  extent,  havs  taken  the 
plaoe  of  the  Italian  product. 

Commeroially,  borax  is  valued  by  evaporating 
to  dr>nies8  a  knoMm  weight  of  the  sample  with 
hydroohloric  aoid,  and  estimating  the  chloride 
\  olumetrioally  in  the  residue  with  silver  nitrate. 
Any  chloride  present  in  the  sample  as  impurity 
is  estimated  separately  and  allowed  for,  the 
percentage  of  borax  being  calculated  from  the 
equation 

Na,B40,+2Ha4-6H,0=2Naa+4H,BO,. 

Propertif.8, — Borax  forms  two  varieties  of 
crystals,  (1)  the  decahydrtUe,  which  Is  produced 
by  allowing  solutions  of  borax  to  or^'stallise  by 
coolinff  down  to  the  ordinary  temperature  ;  (2) 
octahSrcd  borax,  which  is  a  pentahydrate  ^hich 
sepanites  out  when  the  solution  is  allowed  to 
crystallise  above  60^ 

1.  Ordinary  or  prismatic  borax  Na^BfO^, 
10H,0  forma  large  transparent  monoclinic 
prisms  with  truncated  lateral  edges.  They 
effloresce  when  exposed  to  the  air,  have  a  rather 
sweet  cooling  alkaline  taste,  and  a  sp.gr. 
of  1-75.  When  heated  they  melt  in  their 
water  of  crystallisation,  swcU  up,  and  leave 
a  porous  spongy  mass,  called  burnt  or  calcined 
borax  {borcuc  usta),  and  fuse  at  a  red  heat  to  a 
colourless  anhydrous  glass  (vitrified  borax)  with 
a  sp.gr.  of  2*36,  which  gradually  absorbs 
water  from  the  air,  reforming  prismatic  borax. 
At  62®  the  decahydrate  undergoes  transition 
into  the  pentahydrate  Na,B407,6H,0.  At 
130"*  the  salt  contains  3  mols.  H,0 ;  at  150°, 
2  molB.  H,0 ;  at  180^  1  mol.  H,0.  At  318'' 
it  becomes  anhydrous. 

When  borax  is  distilled  with  methyl  alcohol, 
about  50  p.a  of  the  boric  add  comes  over  fairly 
readily,  and  on  longer  treatment  nearly  60  p.c. 
From  the  liquor  remaining  in  the  flask,  crystals 
of  NaB0,,6GH,0H  separate  (Polenske,  Analyst, 
1902,  34). 

Borax  dissolves  in  water,  but  is  insoluble  in 
alcohol.  The  aqueous  solution  has  an  alkaline 
reaction,  and  changes  the  colour  of  an  alooholic 
solution  of  turmeric  to  brown ;  a  small  quantity 
of  a  mineral  acid  restores  the  original  yellow 
colour,  but  a  laiger  quantity  liberates  bono  acid 
in  sufficient  quantity  to  produce  the  character- 
istic brown  colouration.  The  following  deter- 
minations of  its  solubility  are  those  of  Horn 
and  van  Wagoner  (Amer.  Ohem.  J.  1903, 
346) :— 


f 

100  grams  H,0  dis- 
solve of  anhydrous 
borax  JSb^b^Oj 

1? 

100  srams  H,0  dis- 
solve of  anhydrous 
borax  KasB^O, 

6® 
21-5' 

1  '3  gram 
.     2-8 

60® 
70® 

.   10-9  grams 
.  24-4 

80® 

.     3-9 

80® 

.  31-4 

46® 

.     81 

90® 

.  40-8 

60® 

.   10-5 

100® 

.  52-8 

56® 

.   14-2 

For  conditions  determining  the  crystallisa- 
tion  of  borax,  see  Levi  and  Castellani  (Gazz. 
chim.  ital.  1901,  40, 1.  138). 

At  the  temperature  of  27®,  borax  solutions 
hold  1  lb.  of  borax  to  the  imperial  gallon,  and 
have  a  Bp.gr.  of  1-500,  or  10®  Tw.  The  general 
crvstallismg  strength  is  1*160  sp.ffr.,  or  32®  Tw., 
when  the  solution  holds  5  lbs.  cut  borax  to  the 
gallon,  crystallisation  commencing  at  65-5®. 


Borax  is  easily  decomposed  by  adds.  Hydro* 
chloric  add  leaves,  on  evaporation,  sodiom 
chloride  and  free  borio  add.  CaHnmic  acid  is 
absorbed  by  a  solution  of  borax  from  the  air,  and 
no  borax  is  precipitated  on  the  addition  of 
aloohoL  Saturated  with  sulphureUed  hydrogen 
and  mixed  with  alcohol,  the  Uouid  separates  on 
the  addition  of  ether  into  two  layers,  the  lower 
containing  sodium  sulphide,  the  upper  free  boric 
acid. 

It  forms  double  salts  with  arsenious  acid 
of  the  empirical  formula. 

3Na.O-6B,0,*5As,0,+  lOAq 

(Schwdzer,  J.  1850,  257).  With  sodium  fluoride 
it  forms  sodium  fluorborate.  When  1  pt.  tar- 
taric add  is  mixed  with  2  pts.  of  a  hot  sola- 
tion  of  borax,  boric  acid  separates  out  on 
cooling.  If  the  tartaric  add  be  increased,  the 
separation  of  boric  add  likewise  increases  up  to 
a  certain  point,  after  which  it  diminishes,  and 
ultimatdy  is  no  longer  separated.  Acid  tartrate 
of  potassium  forms  a  double  salt  with  borax. 
Silicic  acid  is  insoluble,  or  nearly  so,  in  solutiona 
of  borax. 

Benzoic,  tartaric,  and  gallic  acids  dissolve 
more  readily  in  borax  than  in  water.  Many 
fatty  acids  and  resins  dissolve  as  readily  in 
borax  as  in  alkaline  leys,  the  borax  behaving 
like  a  mixture  of  boric  acid  and  free  soda. 

Borax  fuses  at  730®  and  readily  dissolves  and 
unites  with  metallic  oxides,  forming  a  fusible 
glass  of  a  double  salt,  which  property  renders  it 
of  great  use  in  soldering  and  in  metallurgical 
operations  and  in  blowpipe  analysis,  the  glasses 
thus  formed  often  exnibiting  charactoriBUo 
colours.  It  is  used  also  in  the  preparation  of 
easily  fusible  slass  fluxes  for  enamels  and  glazes. 

2.  Octahe&d  borax  Na,B40,,6HtO  u  ob- 
tained bv  allowinff  a  saturated  solution  of  borax 
to  oool  down  to  aoout  60®  in  a  warm  plaoe  and 
removing  the  crystals. 

The  crystals  are  regular,  transparent  octa^ 
hedra,  harder  than  the  ordinary  borax.  They 
have  a  conohoidal  fracture  and  a  sp.gr.  of  1-8. 
They  do  not  chan^  in  dry  air,  but  abscnrb 
moisture  very  readily  and  become  prismatio. 
They  fuse  more  readily  than  the  prismatic 
crystals,  and  with  less  intumesoenoe,  and  with* 
out  splitting.  Octahedral  borax  is  therefore 
better  adapted  for  soldering  and  as  a  flux  than 
oommon  borax*  and  the  smaller  quantity  of 
water  (a  difference  of  17  p.o.)  diminishes  the  cost 
of  transport.  The  prismatic  variety  is»  how- 
ever, generally  preferred,  probably  because  it  is 
cheaper  weight  for  weight. 

Tne  oommonest  impurities  in  borax  are 
sodium  carbonate  and  small  quantities  of 
chlorides  and  sulphates  of  sodium,  calcium,  and 
magnesium.  It  is  ocoadonally  adulterated  with 
earthy  matters,  alum,  and  sodium  chloride.  It 
should  dissolve  in  two  parts  of  boiling  water  and 
should  not  effervesce  with  acids.  Tne  aqueous 
solution  should  not  be  rendered  turbid  when 
treated  witii  an  alkali,  or  with  barium  chloride 
or  silver  nitrate  in  presence  of  nitric  add. 

The  manufacture  of  borax  from  boric  add. 

This  industry  is  chiefly  assooiated  with  the 
production  from  the  Tuscan  lagoons.  The  arade 
add,  packed  in  larse  casks  weishing  about  13 
cwts.,  on  arrival  at  me  borax  works  is  first  of  aU 


BORON. 


047 


nuuupulated  in  the  casks  thomselves.  For  this 
purpose,  Uie  cask  is  placed  on  what  is  termed  a 
■Ullage,  the  head  taken  off,  the  acid  loosened 
with  a  spade  and  treated  with  small  quantities 
of  water  for  the  purpose  of  washing  out  the  sul- 
phates of  ammonia  and  magnesia,  which,  on 
account  of  their  greater  solubility,  easily  sepa- 
rate from  the  less  soluble  boric  acid,  the  wsah- 
ings  being  used  for  the  recovery  of  the  ammonia 
and  magnesia  they  contain,  whilst  the  acid, 
wh'oh  formerly  contained  83*46  p.o.  BaO«3Aq. 
or  equivalent  to  128*5  p.c.  borax,  is  brought  up 
to  a  strength  of  96-67  p.c.  B,0,3Aq.  or  equivalent 
to  148*87  p.o.  borax.  The  acid,  after  draining 
for  twenty-four  hours,  is  then  placed  in  wicker 
baskets  and  transferred  to  the  saturators.  These 
are  made  of  wrought-iron  }  plates,  having  a 
diameter  of  10  feet,  ege-ended,  height  9  feet  6 
inches,  provided  with  nopper  and  swivel  dis- 
charge, stiU  head,  inspection  glasses,  run-off 
stop-cocks,  and  connected  by  steam  pipes  with  a 
penorated  iron  coil  in  the  bottom  of  the  pan  for 
the  purpose  of  boiling  the  borax  liquor  with 
injected  steauL  There  is  also  a  manhole  with 
movable  cover.  When  the  saturator  is  ready 
for  charging,  liquor  is  pumped  in  to  the  height 
of  4  feeC  or  2300  gallons,  n  hich  is  then  boUed 
with  steam  and  boAa  ash.  Anhydrous  sodium 
carbonate  is  then  added,  about  23  cwts.  being 
generally  required  to  60  cwts.  of  acid.  When 
the  soda  ash  is  all  dissolved,  the  manhole  lid  is 
placed  on,  and  the  boric  acid  is  put  in  by 
degrees  through  a  hopper,  half  a  hundredweight 
at  a  time.  At  each  addition  of  acid  a  brisk 
ebullition  of  carbonic  acid  takes  place,  which 
passes  along  the  still  head,  and  after  being  de- 
prived of  its  ammonia  may  be  utilised  for  making 
bicarbonate  of  soda. 

After  the  saturator  has  received  its  charge  of 
soda  ash  and  acid,  the  liquor  is  thoroughly  boiled 
for  five  hours  and  allowed  to  settle,  in  order  that 
the  solid  impurities  may  subside.  This  gene- 
rally occupies  from  eight  to  ten  hours,  after 
wbioh  the  liquor  is  run  into  large  wrought- 
iron  vats  12  feet  long,  6  feet  wide,  4  feet  deep, 
into  which  the  wires  made  of  iron,  technically 
called  '  straps,'  are  suspended  over  bars  of  wood 
laid  across  the  top  of  the  vat.  The  liquor  on 
cooling  crystallises  on  the  wires,  sides,  and 
bottom  of  Uie  vat,  and  when  the  temperature  has 
fallen  to  26*  (80*F.),  the  liquor  is  siphoned  off 
from  the  vats,  and  men  fpt  in,  and,  bv  the  aid  of 
ircm  bars  terminating  m  a  ohisellea  end,  first 
remove  the  crystallised  borax  from  the  straps, 
then  out  np  the  borax  crystallising  on  the  bottom 
of  the  vat,  and  lastly  knock  down  the  sides. 
This  borax  is  not  of  sufficient  purity  for  the 
market,  and  is,  therefore,  subjected  to  a  second 
refining,  and,  if  necessary,  bleaching.  For  this 
purpose  a  series  of  pans,  called  refining  pui>>  Are 
employed;  they  are  also  of  wrougnt  iron, 
circular,  9  feet  duameter,  egg-ended,  8  feet  deep, 
open  at  the  top  and  provided  with  cradles  of 
wrought  iron  perforated  with  holes,  suspended 
by  iron  chains  from  a  patent  block  overhead  in 
such  a  manner  as  to  be  raised  or  lowered  in  the 
pans  as  required.  The  pans  are  boiled  with 
steam  issuing  from  a  perforated  pipe  in  the 
bottom.  They  are  first  hidf  filled  with  water,  or 
some  of  the  clearest  liquor  from  a  previous 
operation,  and  when  the  liquor  is  boiling  crude 
borax  is  thrown  into  the  cradle  and  allowed  to 


dissolve.  The  right  amount  of  borax  is  tested 
by  means  of  the  Twaddell  hydrometer,  which 
should  read  30*  when  the  liquor  is  of  the  required 
strength.  About  5  cwts.  of  sodium  carbonate  is 
added,  and  a  little  chloride  of  lime,  and  the 
whole  thoroughly  boiled.  The  saturated  liquor 
is  then  allowed  to  settle  in  the  pans  for  ten  hours, 
covers  being  placed  on  them  to  prevent  the 
liquor  chilling ;  the  pans  are  run  off  into  vats  of 
similar  size  and  shape  to  those  employed  in  the 
first  process,  and  the  borax  allowed  to  cr>'BtaUise, 
which  takes  six  days.  Upon  the  expiration  of 
that  time,  the  liquor  is  siphoned  off  to  a  well, 
made  by  sinking  a  wrought-iron  tank  in  the 
ground  below  the  level  of  the  vats,  and,  if  impure, 
IS  pumped  up  to  the  refining  pans  to  be  used  over 
again,  and  if  sufficiently  pure  is  pumped  to  boil- 
ing-doMm  pans,  to  be  concentrated  to  such  a 
degree  as  to  yield  a  further  crop  of  borax. 

The  liquors  from  the  first  vats  are  also 
pumped  to  the  boiling-down  pans,  where  the} 
likewise  undergo  a  process  of  concentration. 
These  boiling-down  pans  are  made  of  wrought 
iron,  and  are  capable  of  holding  about  4O0O 
gallons.  They  are  provided  with  (vy-steam  coils, 
and  are  superior  to  other  moans  of  concentra- 
tion from  the  fact  that  they  are  completely 
under  control,  and  the  evaporation  of  the  liquor 
can  be  regulated  as  fast  or  as  slow  as  may  be 
necessary.  The  liquors  in  these  pans  are  concen- 
trated until  they  reach  a  sp.gr.  of  1*300,  or  60* 
Tw.,  when  they  are  run  off  into  vats  to  yield  first 
a  crop  of  borax,  and  then  upon  reaching  a  tem- 
perature of  80*F.  they  are  siphoned  off  into 
other  vats,  where  they  yield  a  crop  of  Glauber 
salts,  or  sodium  sulphate,  after  which  the  liquors, 
being  rich  in  sodium  carbonate,  are  used  again 
in  the  saturators  for  making  up  a  treah  batch  of 
borax  with  acid  and  soda  ash.  The  mother 
liquors,  strong  in  common  salt  and  weak  in 
sodium  carbonate,  are  further  concentrated  in 
jacketed  pans,  where,  on  continued  boiling,  the 
salt  falls  to  the  bottom,  is  collected  by  means 
of  rakes,  and  fished  out  with  perforated  scoops 
provided  with  long  wooden  handles,  and  the  salt 
IS  ladled  into  iron  baskets  set  over  the  pans  and 
allowed  to  drain.  By  this  means  all  the  salts 
contained  in  the  soda  ash  and  boric  acid  are 
saved,  and  nothing  is  run  to  waste. 

The  washings  Irom  the  boric  acid  in  the 
first  process,  containing  the  ammonium  sul- 
phate and  magnesium  sulphato,  are  collected 
together,  and  placed  in  a  wrought-iron  still  pro- 
vided with  a  dry-steam  coiL  The  reouisito 
amount  of  sodium  carbonato  is  then  added,  and 
the  ammonium  carbonato  is  distilled  off,  yield- 
ing a  highly  concentrated  and  very  pure  carbon- 
ate of  ammonia  liquor,  which  is  either  sold  in 
that  state  or  utilised  for  making  the  purest 
volcanic  ammonia  salts. 

The  borax  from  the  refined  «vats,  consisting 
of  the  straps  and  sides,  is  carried  to  the  packing 
room,  there  to  be  picked,  selected,  and  packea 
in  casks,  whilst  the  borax  bottoms,  not  b«ing  in 
the  form  of  merchantable  borax,  are  refined  again. 

Manufadure  of  borax  from  borate  of  lime. 
The  mineral  is  first  crushed  in  a  stone 
breaker,  the  size  of  jaws  being  8  inches  and 
known  as  No.  4,  easily  capable  of  crushing 
12  tons  in  twenty-four  hours.  As  the  minend 
passes  through  it  is  taken  up  by  an  elevator  and 


648 


BORON. 


run  through  millstones,  30  inches  in  diameter, 
and  placed  by  the  side  of  the  crusher.  There 
are  two  jmirs,  one  grinding  fresh  ore  and  the 
other  gnnding  the  tailings.  The  millstones 
deliver  the  powdered  ore  into  another  elevator, 
which  passes  it  through  a  bolting  or  sifting 
machine,  10  feet  Ions  and  30  inches  in  diameter, 
)iaving  octagonal  sides,  the  bolting  cloth  being 
of  silk  known  as  No.  8.  As  considerable  fine 
and  impalpable  dust  arises  from  the  siftinff,  it  is 
kept  down  by  means  of  an  exhaust  fan  bfowing 
the  dust  into  a  dust  room.  The  fine  mineral  is 
conveyed  by  means  of  an  Archimedean  screw 
and  elevator  into  bins,  each  holding  a  certain 
quantity  and  placed  over  the  saturators.  These 
are  wrought-iron  tanks  capable  of  holding  a 
charge  of  2600  gallons,  and  provided  with  suit- 
able agitators  and  either  dry  or  wet  steam  coils, 
the  bottom'  of  the  saturators  beii^  connected 
«  by  3-inch  wrousht-iron  valves  and  pipes  to  a 
powerful  pump  for  the  purpose  of  removing  the 
contents  of  the  saturator  when  desired.  The 
saturators  are  grouped  to|;ether  in  sets  of  four 
for  facilitating  uie  liziviation  of  the  contents  by 
means  of  repeated  washings,  after  the  first  de- 
composition of  the  mineral.  The  saturators, 
as  in  the  case  of  the  manufacture  of  borax  from 
borio  acid,  are  first  charged  with  liquor  and 
broueht  to  the  boil ;  a  charge  of  soda  ash, 
usuafiy  about  30  cwts.,  being  put  in,  which  in 
sufficient  to  decompose  three  tons  of  the  borate 
of  lime  which  is  gradually  added  after  the  soda 
ash  is  all  dissolved.  The  soda  ash  gradually  but 
completely  decomposes  the  sesquiborate  forming 
calcium  carbonate,  borate  of  soda,  and  biborate 
of  soda : 
C2a,B,Oii+2Na,CO, 

-=2CaGO,+Na,B40,+2NaBO,. 
After  boiling  five  hours  the  steam  and 
affitators  are  stopped,  and  the  muddy  liquor 
afiowed  to  settle  for  ten  hours,  after  which  time 
the  dear  supernatant  liquor  is  run  off  to  vats  to 
crystallise,  and  the  reddue  is  again  washed  with 
weaker  liquor  from  the  saturator  previously 
washed,  the  operation  being  repeated  of  boiling 
and  washins  with  the  gradually  weaker  liquors 
from  the  oUier  saturators  in  rotation.  By  the 
time  the  mud  has  received  eight  washings,  the 
last  being  ^ith  water,  the  whole  of  the  borax 
will  have  been  removed,  and  the  chalk  which  is 
left  is  then  pumped  through  an  iron  filter  press, 
which  completely  presses  out  the  remaining 
weak  liquor  and  leaves  the  chalk  in  a  solid  cake, 
which  is  generally  thrown  to  one  side,  being  too 
impure  for  any  purpose.  The  first  liquor  run  to 
the  vats  contams  the  biborate  and  borate  of 
soda,  together  with  carbonate  and  sulphate  of 
soda  in  solution.  The  biborate  of  soda  or  borax 
crystallises  out  after  cooling  in  the  vats  for 
about  six  days,  leaving  the  borate  of  soda  in 
solution.  The  liquor  is  then  siphoned  off  into 
the  well  and  pumped  to  the  boiung-down  pans, 
where  it  undergoes  the  process  of  concentration 
until  it  reaches  a  sp.^.  of  1-360  to  1-400  (70° 
to  80*Tw.),  when  it  is  run  off  into  vats  and 
allowed  to  throw  a  further  crop  of  borax.  The 
mother  liquor  is  now  of  a  syrupy  consistence, 
and  is  pumped  into  a  decomposing  tank,  where 
carbon  dioxide  is  blown  through  it.  The  following 
decomposition  takes  place : — 

4NaBO.+CO,-Na,B40,+Na,CO, 


The  borax  falls  to  the  bottom  of  the  tank  in 
a  iinely  divided  state,  whilst  the  sodium  car- 
bonate remains  in  solution,  and  can  be  used  over 
again  in  the  saturators  for  the  first  operation. 
The  refining  of  the  borax  from  the  first  process  is 
the  same  as  that  employed  in  the  borio  aoid 
process,  and  therefore  need  not  be  further 
described.  The  only  precaution  necessary  is  the 
addition  of  a  little  bicarbonate  of  soda  in  the 
pans  to  decompose  any  borate  of  soda  that  might 
be  associated  with  the  borax.  Three  tons  of 
borate  of  lime  produce  2  tons  of  borax  and  1  ton 
of  borax  in  the  state  of  metaborate  of  soda.  Meta- 
borate  of  soda  may  be  formed  by  mixing  the  con- 
centrated solutions  of  borax  and  oaustio  soda 
together  in  their  equivalent  quantities,  and 
evaporating  to  70^Tw. : 

Na,B«07+2NaHO=4NaBO,+H,0 
from  which  the  metaborate  of  soda  crjrstalliset 
in  needle-shaped  crystals  having  the  formula 
NaB0„4H,0. 

100  parts  of  metaborate  of  soda,  when  de- 
composed by  carbonic  acid,  produce  69*6  parts 
of  borax  and  34*4  parts  of  sodium  carbonate  ; 
about  30  cwts.  of  borate  of  soda  thus  produce 
20  cwts.  of  borax. 

The  following  process  is  used  by  Masson, 
Gembloux,  and  TiUi^re,  Brussels.  An  am- 
monium salt  is  treated  with  lime  in  a  distilling 
column  and  the  ammonia  set  free  is  passed  into 
water  contained  in  a  digester,  and  the  digester  ia 
then  charged  with  carSonic  or  sulphurous  acid. 
The  digester  is  gently  heated  and  pandermite  is 
introduced.  It  is  then  closed  and  more  strongly 
heated  for  several  hours,  whilst  the  contents  are 
mechanically  agitated  and  are  transferred,  when 
the  action  is  complete,  to  filter  presses,  whenco 
the  liquor  passes  to  a  reaction  chamber  where  it 
is  ag|itated  with  sodium  chloride  and,  after 
addition  of  a  little  ammonia,  is  discharged  into 
crystallisers.  After  removal  of  the  borax  which 
crystallises  out,  the  mother  liquor  is  used  instead 
of  water  in  the  succeeding  operation.  After 
several  operations,  the  mother  liquor  requires  a 
special  treatment. 

In  this  process,  an  ammonium  biborate  is 
first  obtained  b^  the  ammonium  carbonate 
treatment  of  calcium  borate,  and  from  this  am- 
monium salt  borax  is  obtained  by  double  do- 
comjposition  with  sodium  chloride.  Boronatro- 
calcite  may  be  used  instead  of  pandermite  if  the 
process  is  slightly  modified. 

Manufaetun  of  borax  from  uUxiie, 
Borax  is  manufactured  from  this  mineral  at 
the  various  deposits,  and  also  in  FWl%nd, 
France^  and  Germany,  to  which  places  it  is  ex- 
ported from  Chile  and  California,  selected  and 
packed  in  sacks. 

The  first  operation  consists  in  reducing  the 
material  to  a  state  of  fine  division,  and  for  this 
purpose  a  mill  is  used  so  constructed  as  to  tear 
the  borate  to  pieces  instead  of  grindinff  it,  which, 
owing  to  its  fibrous  silky  nature,  is  found  pre- 
ferable. 

The  borate  is  then  mixed  with  its  proper 
proportion  of  soda  ash  and  bicarbonate  of  sooa, 
or  soda  ash  and  boric  acid,  havins  regard  to 
the  fact  that,  if  associated  with  mudi  gypsum,  a 
proportionate  additional  allowance  of  soda  ash 
must  be  made,  as  the  gypsum  decomposes  the 
sodium    carbonate,    formioR    sodium    sulphate 


BORON. 


049 


and  chalk.    The  composition  of  uloxite  being 

Ca,B.0||-Na,B40.,  it  reqnizes  one  eauivalent  of 
bicarbonate  of  Booa  and  one  equivalent  of  car- 
b<mate  of  soda  to  decompose  it : 
2(Oa,B,Oi,Na,B407)+2NaHCO,+2Na,CO, 

■=6Na,B40,+4CaCO,+H,0. 
These  ingredients  are  all  mixed  together  in  the 
dry  state.  The  process  adopted  is  similar  to  the 
processes  already  described — ^namely,  that  of 
first  boiling  the  liquor  in  the  saturator,  then 
gradually  adding  the  crude  material,  boiling, 
settling,  liziyiating. 

100  parte  of  the  ulezite,  testing  43  p.c  boric 
acid,  require  10  parte  of  bicarbonate  of  soda 
and  12  parts  of  carbonate  of  soda,  for  its  con- 
version into  117  parts  of  borax 

ManufaUwrt  of  borax  from  crude,  borax. 

This  l»anch  of  the  industry  is  generall}* 
carried  on  at  the  borax  marsh.  It  may  bfe 
desirable  to  give  a  description  of  the  Saline 
Valley,  Inyo  county,  California,  where  the  most 
extensive  deposit  of  natural  borax  exists  in 
North  America,  before  entering  into  the  details 
of  refining. 

The  valley,  situated  on  the  eastern  slope  of 
the  Sieira  Nevada  Mountains,  11  miles  from  the 
Carson  and  Colorado  railroad,  is  18  miles  long  and 
12  miles  wide,  suirounded  with  mountainous  hills 
which  afford  no  outlet,  and  therefore  the  valley 
may  be  said  to  be  the  bottom  of  a  dried-up  lake. 
At  the  point  of  deepest  depression  an  area  of  over 
1000  acres  is  covered  with  crude  borax  from  6  to 
18  inches  in  depth.  The  colour  of  the  crude 
material  as  it  lies  upon  the  level  plain  is  a  peculiar 
grey  yellow.  The  borax  in  Saline  Valley  is 
mixed  with  sand,  which  is  volcanic  ash  and  de- 
composed lime  rock,  sodium  sulphate,  sodium 
carbonate,  and  sodium  chloride,  llie  surround- 
ing hiUs  consist  of  granite,  marble,  dolomite, 
black  lava,  and  felspar.  The  composition  of  the 
crude  material  varies  in  strength  from  10  p.c.  of 
borax  up  to  90  p.a,  whilst  in  some  places  on  the 
marsh — under  a  crust  composed  of  sodium  sul- 
phate, sodium  carbonate,  and  common  salt — beds 
of  tincal,  or  large  crystals  of  borax,  some  two 
feet  in  thickness,  are  found ;  whilst  below  the 
tincal  there  is  a  strong  saturated  yellowish 
liquor  containing  1  lb.  of  borax  to  the  gallon. 
All  the  manipulation  that  is  required  is  to 
shovel  off  the  surface  of  the  marsh  to  a  depth 
of  18  inches  and  cart  the  material  to  long 
hemispherical  wrought-iron  pans  set  on  arohes 
of  stone,  fired  beneath  with  wood  fuel  obtained 
in  the  neighbourhood.  The  pans  are  charged 
with  water,  and  the  crude  material  thrown  in 
and  vifforously  stirred  with  lone  poles,  until, 
with  the  aid  of  heat,  all  the  sorable  salts  are 
dissolved.  The  fires  are  then  withdrawn,  and 
the  contents  of  the  pans  allowed  to  settle  for  ten 
hours,  when  the  liquor  is  draAvn  off  into  vats, 
where  the  borax  crystallises  out.  The  mother 
liquor  after  six  days  is  drawn  off,  and  the  borax 
is  taken  out  and  packed  into  sacks  for  shipment. 

Borax   and  boric  acid  are  applied  in  the 
manufacturing  industries  as  foUows  : — 
Brick  and  tiU  makers.    Glazed  surfaces. 
Candle  tnakers.    Pftparation  of  wicks. 
Cement,    Making  the  finest  kinds,  which  take  a 

poluh. 
China  and  earthenware.     In   preparing  a  frit 

used  for  glazing  what  is  technically  termed 


'  biscuit  ware '  in   pottery  of    all   descrip- 
tions. 
Cohur  makers.     In  preparing  Guignet's  green 

and  borate  of  manganese  (a  drier). 
Copperemitha,    In  braiing. 
DniffgUts,    Pharmaceutical  prepaiations. 
EnameUed  iron.    An  enameUea  coating  to  cast 

and  wrought  iron. 
Glass,    Making  pastes  and  as  an  ingredient. 
Hat  maieers.    Dissolving  sheUao  for  a  stiffener. 
Ironsmiihs,    In  welding. 
Jewellers,    In    solderins.    (Ancient    name    for 

borax, 'chry80Colla,^eold-glue.) 
Laundresses,    As  a  starch-glase  for  linen. 
Paper  makers.    Superfine  note  and  highly  glazed 

paper  and  cards. 
Pork  packers.    Curing  and  preserving  hams  and 

bacon. 
Safe  makers.    Lining  safes  to  resist  fire. 
Soap  makers.    As  an  emollient. 
Tanners,    Dressing  leather. 
Textile   manufacturers.    Solvent-bleach;     mor- 
dant: fireproof er. 
Timber  merchants.    In  preparation  of  hard  from 

soft  wood. 

Zlne  borate  is  formed  by  adding  borax  in 
slight  excess  to  a  solution  of  a  zinc  salt.  For 
conditions  of  formation,  see  Borohers  (Zeitsch. 
anorg.  Chem.  1910,  68,  269). 

Parliontas  are  salts  of  the  acid  HBO,  or 
0 


HO 


/ 


•^\ci 


which  has  not  been  prepared  in  the 


free  state  on  account  of  its  instability.  The 
alkali  and  alkaline  earth  salts  are  soluble  in  water 
and  have  an  alkaline  reaction.  They  behave  in 
solution  like  mixtures  of  borates  with  hydrogen 
peroxide ;  the  active  oxygen  being  liberated  by 
heat,  by  acidifying  the  solution,  or  by  large 
dilution.  Oxydases,  reductases,  and  manga- 
nese dioxide  cause  them  to  give  up  the  whole  of 
their  reactive  oxygen.  They  convert  chromic 
acid -and  molybdatos  into  perchromic  acid  and 
yellow  permolybdatee.  Tney  readily  oxidise 
protoxides  and  their  salts  into  higher  oxides,  but 
do  not  always  fojm  perborates  with  them. 
Ferrous,  merouzous,  manganous,  and  lead  salts 
yield  higher  oxides ;  the  salts  of  other  metals 
yield  perborates  of  an  indefinite  or  baaio  com- 
position. Perborates  of  the  alkali  metals  may 
be  obtained  by  careful  precipitation  of  solutions 
of  alkali  borates  with  alcoh(M  in  the  presence  of 
hydrogen  peroxide. 

Ammonium  perborate  NH4BO,,HaO  is  the 
best  characterised  of  the  several  perborates 
resulting  from  the  ^.action  of  ammonia  and 
hydrogen  peroxide  on  ammonium  borate.  It 
contains  16*84  p.c.  of  active  ox\^en. 

Potassium  biperborate  KBsO„2H,0  is 
obtained  by  the  action  of  hydrogen  peroxide 
on  potassium  borate.* 

Sodium  f>erborate  NaB0„4H,0.  When 
248  grams  of  boric  acid  are  mixed  with  78  erams 
of  TOdium  peroxide  and  added  graduaUy  to 
2  litres  of  cold  water,  the  mixture  dissolves  at 
first,  but  later  a  crystalline  substance  separates 
out  which  may  be  filtered  off  and  dried.  This 
substance,  wmch  has  a  composition  Na,B408, 
10H,O,  is  called  *  perborax,*  and  is  soluble  in 
water  to  the  extent  of  42  grams  per  litre  at  11°. 
When  one-half  of  its  sodium  is  displaced  b^  a 
mineral  acid,  a  crystalline  precipitate  of  sodtum 


050 


BORON. 


perboraU   NaOO*B^  I +4H,0    separates   out. 

This  is  a  venr  stable  substanoe,  and  can  be  pre- 
served indennitely  at  ordinary  temperatures. 
It  dissolves  readily  with  slight  decomposition  in 
water  at  W*-Wy  and  a  vigorous  ebullition  of 
oxygen  takes  place  at  lOO"".  The  cold  fiqueous 
solution  possesses  all  the  properties  of  hydrogen 
peroxide.  When  powdered  sodium  perborate  is 
added  gradually  to  50  p.c.  sulphuric  acid,  and 
the  solution  filtered  through  guncotton  a  very 
stfon^  (150-200  vols.)  s^ution  of  hydrogen 
peroxide  is  obtained. 

For  the  constitution  of  the  perborates,  see, 
Bosshard  and  Zwicky,  Zeitsch.  angew.  Chem. 
1912,  25,  993. 

Oboanio  Dsbivatiyss  or  Bobio  Aao. 

Aniline  boraie,  and  compounds  of  piperidine, 
coniine,  tdrahydropiinoline,  and  tetramethyl- 
ammonium  hydroxide,  have  been  prepared  by 
L.  &  T.  Spiegel  (J.  Soc.  Chem.  Ind.  1905,  103). 
The  metUkyl  and  bomyl  eaten  are  readilv 
prepared  by  heating  menthol  and  bomeol  with 
Done  acid,  xylene  being  used  as  a  medium  in 
the  latter  case  (Verein  Chininfabriken,  Zimmer 
&  Co..  Eng.  Pat.  11574,  1906). 

Ethyl  borostdicykUe,  or  *  boryl,*  is  prepared  by 
boiling  together  62  grams  of  bone  acid  and 
138  grams  of  salicylic  acid  wiUi  200  c.c.  of  water. 
The  resulting  borosalicylio  acid  is  esterified  by 
adding  60  grams  of  95  p.c.  alcohol  and  heating 
with  40  grams  of  sulphunc  acid.  It  forms  needle- 
shaped  crystals  which  are  more  convenient  than 
oil  of  winter-green  for  many  medidnal  purposes 
(Cohn,  Cheqi.  Zentr.  1911,  1;  1806). 

Zinc  boropicrate,  or  '  tiirysyl,*  is  the  product 
obtained  by  boilixig  together  boric  ana  picric 
acids,  and  saturating  the  mixture  with  'zinc 
oxide.  It  is  a  yellow  powder  used  as  a  medicinal 
antiseptic  (Monteil,  J.  Soc.  Chem.  Ind.  1908, 
354). 

Phenyl  horale  B(0Ph)g,  diphenylboric  acid 
B(OH)(OPh)„  m-tolyl  borate  B(OC,H«Me)p  and 
fi-napfUhyl  borate  B(CioH70)a,  together  with 
several  other  aryl  halogen  boron  compounds  and 
f'borobenxoic  acid  C0,H-C,H4-B(0H)„  have 
been  prepared  by  Michaelis  (Annalen,  316, 
19-43). 

Boreitraies  are  valuable  as  remedies  in  oases 

of  kidney  disease  and  urinary  oalculL  Their 
solvent  power  for  urates  and  phosphates  is 
ereater  than  that  of  lithium  faiensoate.  The 
diborooitrates  are  best  adapted  for  the  purpose. 
The  following  are  known : — 

Magnesium  triborooitrate(CfH,0 ,)  gMgg(B,H,04)  g 
„  diborocitrate  (C«H.q,)gMgg(B,Hs04), 
„       monoborocitrate  (C^HfO J,Mg(BHOt) 


Lithium,  potassium,  sodiuxn,  and  ammonium, 
mono-,  di-,  and  tri*borooitrates  of  similar  con- 
stitution have  been  prepared.  Iron  salts  have 
also  been  obtained  containing  respectively  8  and 
16  p.c.  of  iron  by  acting  on  sodium  di-  and 
mono-borocitrate  with  ferric  hydrate  (Scheile, 
Pharm.  J.  [3]  11,  389). 

The  magnesium  compounds  possess  strong 
anUseptic  properties. 

DBTionoir  aitd  Estuiatios  of  Bobov. 

Boron  almost  always  occurs  in  the  form  of 
boric  acid.    When  the  acid  is  in  the  free  stale 


I  it  can  leadUy  be  xecogoised  by  the  green  colour 
which  it  gives  to  the  flame,  and  by  its  action 
upon  turmeric. 

Turmeric  paper,  when  moistened  with  a  solu- 
tion of  boric  acid  and  dried,  acquires  a  cherry-red 
colour,  which  is  changed  to  olive-green  on  moisten- 
ing with  an  alkalL  Acid  solutions  of  ziroonic, 
tantalic,  niobic,  and  molybdic  acids  also  colour 
turmeric  brown.  Cassal  and  Qerrans  (Chem. 
News,  1903,  27)  find  that  the  sensitiveness  is 
greatly  increased  by  the  addition  of  oxalic  acid, 
and  l>ase  a  oolorimetric  method  of  estimation 
of  boric  acid  on  this  reaction. 

The  green  colour  imparted  to  flame  is  a  very 
delicate  test  for  boron  (according  to  Merz,  J.  pr. 
Chem.  80, 487, 1  part  in  1400  may  be  detected  by 
means  of  it).  It  is,  however,  to  be  noted  that 
salts  of  copper  likewise  colour  flame  green, 
as  well  as  certain  compounds  of  chlorine  snd 
barium  and  thallium.  When  the  boric  aoid  is 
combined  with  a  base  the  compound  in  the  state 
of  powder  ia  decomposed  by  means  of  sulphuric 
acid,  and  the  boric  acid  extracted  bv  alcohol. 
Compounds  not  decomposed  by  sulphuric  acid 
are  fused  with  potash  and  digested  with  alcohol 
and  sulphuric  acid. 

The  presence  of  boron  in  minerals  may 
be  detected  by  mixing  the  mineral  in  powder 
with  a  flux  containing  1  part  fluor-spxr  to  4^ 
parts  hydrogen  potassium  sulphate,  made  into  a 
paste  with  water,  and  heating  the  mixture  in 
the  inner  blowpipe  flame,  when  boron  chloride  is 
given  off  which  tinges  the  flame  green ;  or  by 
mixing  the  suspected  substance  with  fluor-spar 
moistening  with  concentrated  sulphuric  acid^ 
and  passing  the  escaping  gas  through  a  tube 
drawn  to  a  fine  point  into  the  non-luminous 
bunsen  flame,  which  it  colours  green. 

The  spectrum  of  boron  shows  three  bright 
lines  in  Uie  green  and  one  in  the  blue.  HarUey 
finds  in  the  spectra  of  boric  acid  and  borax  the 
lines  A.3450'3,  x2407,  and  X2496-3,  which  he 
considers  characteristic  of  boron  (Roy.  Soc 
Ptoc.  35,  301).  (For  the  measurement  of  the 
intensity  of  these  bands,  v.  Lecoq  de  Bois- 
baudran,  Compt.  rend.  76,  883.) 

The  quantitative  estimation  of  boron  is 
difficult,  as  all  borates  are  soluble  to  some 
extent  in  water  and  sloohol,  and  boric  aokl 
cannot  be  heated  without  loss  in  contaot  with 
water. 

One  method  of  direct  determinatioii  is  to 
precipitate  the  boron  as  potassium  borofluoride, 
which  is  quite  insoluble  in  alcohol  (Berzclius, 
Lehrbuch,  3  ed.  10,  84 ;  Stromeyer,  Annalen, 
100,  82;  Thaddeeff,  J.  Soc  Chem.  Ind.  1898, 
953).  This  method  has  been  adversely  criticised 
by  Gooch  and  others,  and  has  been  almost 
entirely  superseded. 

The  most  trustworthy  method  of  estimating 
boron  is  due  to  Qooch.  If  the  hatoa  ia  not 
present  as  boric  acid,  it  is  brought  into  that 
state  by  heating  for  some  hours  in  a  sealed  tube 
with  nitric  acid.  The  resulting  solution  ia 
repeatedly  distilled  with  methyl  alooh<d,  the 
boric  acid  passing  over  in  the  vapour.  The 
distillate  is  tnen  treated  with  an  exactly  weighed 
excess  of  pure  lime,  tnmsferred  to  a  platinum 
crucible,  evaporated  to  dzyness  on  the  water- 
bath  and  strongly  heated.  The  increaae  in 
weiffht  represents  the  boric  anhydride. 

Volumetrically,  boric  add  may  be  estimated 


BRAGA. 


651 


accurately  by  titration  with  caustic  soda,  u&inff 
phenolphthaleln  as  indicator,  if  about  one-tbira 
oi  the  Dulk  of  the  solution  of  glycerol  is  added 
(Thomson,  J.  Soc.  Chem.  Ind.  1894, 432 ;  v.  also 
Analysis). 

A  freshly  prepared  solution  of  manna  mi^ 
replace  the  glyowol  (lies,  Analyst,  1018,  43, 
3267).  Tropaolin  0  (sodium-p-benzene-asore- 
soroinol-sulphonate)  may  be  used  for  the  direct 
titration  of  boric  acid  without  the  addition  of 
mannitol  or  glycerol.  Soda  is  first  neutralised 
by  standard  hydrochloric  acid  in  the  presence  of 
meUiyl  orange  or  p-nitrophenol,  excess  of  sodium 
chloride  not  materially  interfering  with  the 
accuracy  of  the  metnod.  The  mdioator  is 
introduced  as  0'04  p.c.  solution  (Prideauz, 
Zeitsch.  anorg.  Chem.  1013,  83,  362). 

Boron  may  be  estimated  indirecUy  by  digest- 
faig  a  weighed  quantity  of  the  finely  divided 
compound  in  a  platinum  vessel  with  hydrofluoric 
acid,  and  then  with  concentrated  sulphuric  acid. 
On  warming  gently,  the  boron  present  is  expelled 
as  fluoride,  and  after  driving  off  the  excess  of 
sulphuric  acid,  the  quantity  of  bases  in  the 
residue  is  determined.  Their  weight,  deducted 
from  the  weight  of  the  original  substance,  gives 
the  quantity  of  boric  anhy&de. 

When  combined  with  potash  or  soda,  boric 
add  may  be  determined  by  evaporating  the 
solution  of  the  previously  weip;hed  salt  with 
hydrochloric  acid,  and  determining  the  chlorine 
in  the  dry  residue  (Schweizer,  Aiarm.  Gentr. 
1860,  372 ;  J.  1860,  690). 

Crude  boric  acid  (Italian)  is  usually  valued  by 
detwmining  the  water  and  the  substances 
insoluble  in  alcohol,  and  taking  the  rest  as  being 
boric  acid.  According  to  Zschimmer  (Chem. 
Zentr.  1901,  [6]  44,  and  [7]  67),  the  results  are 
icaoourate,  on  account  of  the  water  not  being 
completely  driven  off  under  the  conditions  nsea 
(2  hours  drying  at  46®  and  2  hours  in  desiccator). 

Boron  is  best  estimated  in  the  presence  of 
silicates ;  e,g.  in  tourmaline,  by  the  method  of 
G.  W.  San;ent,  who  has  submitted  all  the 
processes  published  to  examination  and  criticism 
(J.  Amer.  Chem.  Soc  1899,  86^-888}.  The 
mineral  is  fused  with  a]kali  carbonates,  and, 
after  lixiviating  and  acidifying,  the  boric  acid  is 
volatilised  from  the  solution  as  the  methyl 
ester.  A  convenient  form  of  apparatus  for 
performing  this  operation  is  described.  The 
boric  ester  is  subsequently  hydrolysed  by  a 
weighed  quantity  of  pure  lime,  and  estimated  by 
GoMh'i  process. 

A  method  for  its  estimation  in  insoluble 
silicates  is  also  given  by  Wherry  and  Chapin 
(J.  Amer.  Chem.  Soa  1908,  1687-1701). 

A  solution  of  boric  acid  produces  no  change 
of  colour  in  solutions  of  helianthin,  tropasolin, 
and  methyl  orange,  but  a  drop  of  hydrochloric 
acid  immediately  changes  the  yellow  colour  into 
red.  Borax  may  thus  be  titrated  by  the  stronger 
acids  (A.  Joly»  Oompt.  rend.  100,  103). 

(For  the  estimation  of  boric  acid  in  mineral 
waters*  9.  Fresenius,  Zeitsch.  anaL  Chem.  25, 
202.) 

To  detect  boric  acid  in  milk,  baryta  is  added 
to  100  cc  of  milk  till  alkaline.  After  incinera- 
tion, the  ash  is  dissolved  in  a  little  strons  hydro- 
chloric add,  evaporated  to  dryness,  ana  a  solu- 
tion of  turmeric  with  a  drop  of  dilute  hydro- 
chloric acid  added,  and  the  solution  evaporated 
on  a  water-bath.    0-(X)l  p.c  boric  acid  gives 


a  distinct  colour  to  turmeric  in  this  »"f»-nnftr 
(J.  Soc.  Caiem.  Ind.  1887,  663). 

Boric  acid  may  be  rapidly  determined  in 
butter  by  stirring  a  weigbdd  quantity  with  a 
known  volume  of  warm  standard  sulphuric  acid 
till  melted,  aUowing  to  settle,  and  titrating  a 
portion  of  the  aqueous  part  with  caustic  sods, 
using  phenolnhthaleln.  The  pink  colour  appears 
when  the  sulphuric  acid  has  been  neutralised; 
glycerol  is  then  added  and  caustic  soda  run  in 
till  the  colour  reappears.  The  second  titration 
represents  the  boric  acid(  Richmond  and  Harrison, 
Analyst,  1902,  179). 

BORONATROCALCITE.  An  early  name  (G.  L. 
Ulex,  1849)  for  the  mineral  ulexite,  a  hydrated 
borate  of  sodium  and  calcium  NaCaB(0„8H,0. 
Most  of  the  natural  borates  exported  from  South 
America  (Chile,  Bolivia,  and  Argentina)  are  of 
this  species ;  it  is  also  abundant  in  the  borate 
deposits  of  (California  and  Nevada.       L.  J.  S. 

BOROVERTIM  v.  Synthetic  drugs. 

BORSALYL.  Trade  name  for  sodium  boro- 
salicylate. 

BORYL.  Trade  name  for  ethyl  borosali- 
cylate.  Prepared*  by  boiling  together  solutions 
of  boric  acia  and  salicylic  acid  and  esterifying 
by  the  addition  of  alcohol  and  sulphuric  acid. 
Needle-shaped  ciystals.  Used  in  medicine  as  a 
substitute  for  ethyl  salicylate  (Monteil,  J. 
Soc.  Chem.  Ind.  1908,  364). 

BOSCH,  An  inferior  butter  prepared  in 
Holland.  The  term  is  sometimes  used  as 
synonymous  with  margarine  (^.v.). 

BOSTONITE.  A  trade  name  formerly  in  use 
for  the  Canadian  serpentine  -  asbestos  {v. 
Asbestos).  L.  J.  S. 

BOSWELLIA  SERRATA  (Roxb.)  or  GUGAL. 
The  gum  of  this  plant  (ord.  Burseracece)  is  used  as 
an  incense.  It  is  often  confounded  with  bder- 
lium  and  olibanum(Dymock  Pharm.  J.  [3  J  7, 190)* 

BOTANY  BAY  RESIN  v.  Baisams. 

BOTRYOLITE  v.  Calcium. 

BOTTLE-NOSE  OIL.  An  oil  obtained  from 
the  bottle-nosed  whale,  closely  resembling  sperm 
oil ;  its  sp.gr.  varies  from  0-876  to  0-880  (Allen, 
J.  Soc.  Chem.  Ind.  2,  63). 

BOUILLON  NOIR.  Ferric  aeelaU  (v.  Acsxio 
acid). 

BOU-NEFA.  The  root  bark  of  Thapgia  gar- 
ganica  (Linn.),  an  umbelliferous  plant  growing  in 
the  South  of  Europe  and  Algeria.  It  contains  a 
resin  used  as  a  medicine  in  France. 

BOURNEENE  or  VALERENE.  A  liquid 
hydrocarbon  isomeric  with  oil  of  turpentine, 
secreted  by  the  Drydbaianopa  aronuUica  ((Saertr. ), 
and  holding  in  solution  bomeol  or  Borneo  cam- 
phor. According  to  Wallach  (Annalen,  230, 
226 ;  Caiem.  Soc.  Trans.  [2]  60, 70),  it  is  a  mixture 
of  the  decomposition  products  of  camphene. 

BOURNONITE.  Sulphantimonate  of  copper 
and  lead  CuPbSbSs*  crystallising  in  tabular 
orthorhombio  crystids;  these  are  frequently 
twinned  and  show  re-entrant  angles  at  the  edges, 
hence  the  names  *  cogwheel-ore  *  and  *  wheel- 
ore.'  It  is  found  in  Uomwall,  Hans,  Ao. ;  and 
in  Bolivia.  It  sometimes  occurs  in  sufficient 
abundance  to  be  used  as  an  ore  of  copper  and 
lead.  L.  J.  a 

BOVEY  COAL  v.  Fuil. 

BRAGA*  An  alcoholic  beverage  used  in 
Bon  mania,  prepared  by  the  fermentation  of 
millet.  The  seed  is  boiled  with  about  12  times 
its  weight  of  water  for  14  hours,  the  resulting 


652 


BBAOA. 


▼iM'ous  masB  cooled,  stured   with   watei   and  ] 
allowed  to  ferment.    The  liquid  is  filtered  and 
mixed  with  water,  when  it  ia  ready  for  sale. 
It  is  somewhat  sweet,  and  contains  about  1-3  p.c. 
of  alcohol  by  weight. 

BSAm  POWuBB*    An  explosive  consisting 
of  60  parts  of  a  mixture  of  potassium  chlorate, 

Sotassium  nitrate,  wood  charooal,  and  oak  saw- 
ust  saturated  with  40  parts  of  trinitroglyoerine 
(Wagner's  Jahr.  22,  470). 

BRAN.    The  name  given  to  the  coarser  frag- 


ments, consisting  mainly  of  the  outer  laywi^ 
which  are  produced  m  the  grindmg  or  nulling  d 
cereal  or  other  seeds.  When  the  term  is  used 
without  any  descriptive  adjective,  the  product 
from  wheat  is  usually  understood ;  but  maixe, 
barley,  buckwheat,  rye,  oats,  even  peas  and 
earth  nuts,  when  milled,  yield  products  which 
are  described  as  '  bran.' 

The  following  analyses,  compiled  chiefly 
from  Gierman  and  American  sources,  show  the 
general  average  composition  of  various  *  brans ' : 


— 

Water 

Protein 

Fat 

Sol.carbo- 
hydrates 

Fibre 

Ash 

Wheat  bran,  fine           .... 

13-2 

15-5 

4-8 

54-0 

8-0 

4-5     1 

„     coarse 

13-2 

14-3 

4-2 

52-2 

10-2 

6-9 

„                spring  wheat 

11-5 

16-1 

4-5 

54*5 

8-0 

5-4 

,y         „     winter  wheat 

12-3 

160 

4-0 

53-7 

8-1 

6-9 

Rye  bran  (German) 

12-5 

16-7 

31 

58-0 

5-2 

4-5 

„       „     (American) 

11-6 

14-7 

2-8 

63-8 

3-5 

3-6 

Barley  bran 

10-5 

14-8 

3-6 

67-6 

8-5 

6-0 

Oat  bran     \         ,         .         , 

9-6 

7-6 

2-7 

53-8 

21-6 

5-7 

Maize  bran 

12-5 

9-9 

3-6 

61-5 

9-6 

3-0 

Rice  bran    . 

9-7 

121 

8-8 

49-9 

9-6 

lOK) 

Buckwheat  bran,  fine    . 

12-0 

15-2 

4-5 

60-0 

11-3 

7-0 

„      coarse 

15-6 

8-0 

1*8 

34*2 

37-6 

2-8 

Pea  bran      .... 

11-7 

10-8 

1-7 

46-2 

20-1 

3-5 

Earth  nut  bran    . 

10-5 

21-8 

181 

24-7 

;9-6 

5^ 

The  digestion  coefficients  for  the  constituents 
of  most  varieties  of  bran  are  low,  so  that  their 
food  value  is  in  genoral  not  so  high  as  the  analyses 
would  indicate. 

The  character  and  composition  of  the  bran 
from  any  particular  grain  is  liable  to  considerable 
variation,  accordiag  to  the  method  of  milling 
adopted.  As  a  rule,  the  less  perfectly  the  com 
is  ground,  the  richer  is  the  bran  in  meal  and 
therefore  in  feeding  value. 

It  will  be  noticed  that  bran  is  much  richer 
in  protein*  fat,  ash,  and  fibre  than  the  fine  por- 
tions of  the  meal  from  the  same  grain. 

In  the  case  of  wheat,  the  finer  portions  of  the 
bran  are  known  as  '  middlings  '  and  *  sharps  '  or 
'shorts.'  Usually  the  last  term  denoteis  the 
portions  which  most  nearly  resemble  bran,  while 
''middlings '  refers  to  an  intermediate  product 


more  approximating  to  floor  in  composition, 
though  much  richer  m  protein,  ash,  and  fibre. 

The  processes  employed  in  the  milling  of 
wheat,  however,  are  so  complex  that  about  80 
or  100  products  are  separated.  For  a  study  of 
the  composition  of  the  various  products  of  a 
modem  roller  mill,  see  Clifiord  Richardson  (BulL 
No.  4,  U.S.  Dept.  of  Agric.  Div.  of  Chemis- 
try, reproduced  m  part  9,  BulL  13,  [1898]). 
Usually,  about  70  to  75  p.c  of  the  wheat  is  ob- 
tained as  flour  of  various  grades,  about  20  p.a 
as  bran,  3  or  4  p.c  as  *  shorts,'  and  the  remainder 
as  screenings  and  loss. 

Weinwurm  (Oesterr-Ungar.  Zeits.  Zucker- 
ind.  u.  Landw.  1890)  found  that  from  Hnn- 
ffarian  wheat,  20  p.c  of  bran  of  three  degrees  of 
fineness  were  obtained,  possessing  the  fculowing 
composition : — 


Yield 

P.O. 

Water 

Composition  of  dry  matter 

Protein 

Insol.        Sol. 

in  dU.  acetic  acid 

Fat 

Sol.  carbo- 
hydrate! 

Fibre 

Ash 

Fine  bran 
Medium  bran    . 
Ck)ar8ebran 

16 
2 
2 

11-35 
11-55 
12-37 

13-50 
13-38 
13-44 

3-06 
2-72 
317 

4-54 
3-96 
3-46 

63-64 
63-97 
62-13 

8-71 
9-08 
9-79 

6-56 
6-89 
701 

Snyder  (Studies  on  Bread  and  Bread- 
making  at  the  University  of  Minnesota,  1901) 
examined  the  products  from  the  milling  of  wheat 
by  the  American  methods,  using  a  hiurd  Scotch 
Fife  wheat. 

The  shorts  and  bran  obtained  had  the  follow- 
ing composition  :— 

protein  Total  carbo- 

(NX5'7)  Fat      hydrates  Aih  Acidity 

14-87  6-37      66-47    4-66    014 

14-02  4-39      66-64    6-06    0-23 


Water 
Shorts  8-73 
Bran      9-99 


The  acidity  ia  expressed  in  terms  of  lactic  acid. 


The  carbohvdrates  of  bran  have  been  in- 
vestigated by  shemian  (J.  Amer.  Qiem.  Soc. 
1897,  19,  291).  He  found  the  following  average 
percentages  in  wheat  bran : — 

Total  soluble  carbohydrates  calcu- 
lated as  dextrin      .         .         .7-2  p.c. 

Starch 17-7 

True  pentosans  17-6 

Lisnin  and  allied  substances  11-6 

OeUulose 8*5 


Total  carbohydrates    . 


62*5 


BRANDY. 


6SS 


Other  investigatocB  —  ToUena,  Ghalmot, 
G  anther  and  Stone— have  found  from  22  to 
26  p.0.  of  pentosans  in  wheat  bran,  while  maize 
bran  contains  about  40  p.c 

Girard  (Oompt.  rend.  1897,  lU,  926)  ciTee 
the  resolts  of  the  examination  of  by-proancts 
from  wheat — presumably  shorts  and  bran — by 
a  method  different  from  the  oonyentional  one. 

In  estimating  the  amount  of  water-soluble 
matter  in  products  from  seeds,  he  points  out  the 
necessity  of  using  ice-cold  water,  otherwise  the 
enzymes  present  may  act  upon  the  constituents 
of  the  seed,  and  greatly  increase  the  amount  of 
matter  soluble  in  water. 

The  following  are  the  mean  figures  calculated 
from  analyses  of  the  by-products  from  four 
French  wiieats : — 

Wster     Solnble  In  water     iDSdiible  In  water 
14*72  10-63  74-65 

■ 

The  matter  soluble  in  water  consisted  of — 
proteids  2-70,  carbohydrates  6-16,  inoiganic 
matter  1-77.  The  matter  insoluble  in  water 
consisted  of — gluten  4*66,  starch  28-08,  nitro- 

fenous  woody  matter  6*70,  fats  3-17,  cellulose 
0-22,  inorganic  matter  1-94,  loss  and  undeter- 
mined 0-99. 

The  mineral  matter  in  bran  is  very  hich  as 
compared  with  that  in  the  rest  of  the  seed,  being 
usually  between  6  and  6  p.c.,  whilst  that  in  flour 
is  usually  less  than  0*6  p.c. 

The  ash  of  bran  is  particularly  rich  in  phos- 
phoric acid,  but  poor  in  lime.  The  following 
analysis  by  Wolff  gives  its  usual  composition  : — 


E,0      Na^O       MgO       CaO 
24-0      0^        16-8      4-7 


P,0.     SIO, 


There  is  a  widespread  belief  that  bran  is 
partienlarly  well  fitted,  because  of  its  richness 
m  mineral  matter,  to  supply  the  needs  of 
animals  with  reference  to  the  development  and 
nutrition  of  bone.  But  from  a  study  of  a  bone 
di^w^fA  among  horses  and  mules  in  South  Africa, 
it  has  been  deduced  that  for  normal  bone  nutri- 
tion it  is  necessary  that  animals  be  supplied,  in 
their  rations,  with  phosphoric  oxide  ana  lime  in 
approximately  equal  proportions  by  weight 
(Ingle,  Jour.  Gomp.  Path,  and  Therapeutics, 
1907,  March,  also  Jour.  Agric.  Science,  1908, 
3,  22).  From  this  point  of  view,  bran  is 
particularly  ill  suited  to  aid  bone  development, 
since  it  contains  an  overwhelming  preponderance 
of  phosphoric  acid  over  lime,  being  in  the  ratio 
of  100  to  9  in  the  above  analysis,  while  in  some 
samples  it  is  as  high  as  100  :  6-6.  That  bran 
has  an  injurious  action  upon  bone  nutrition 
when  used  in  laige  quantities,  is  shoMm  by  the 
occurrence  of  a  peculiar  bone  disease  in  horses 
known  as  *  bran  rachitis '  or  *  millers'  horse 
rickets,'  observed  in  animals  fed  largely  on  bran. 

The  phosphoric  acid  in  bran,  however,  does 
not  exist  entirely  as  metallic  phosphates.  Ac- 
cording to  Patten  and  Hart  (Bull  260,  New 
York  Agric.  Expt.  Station,  1904)  about  68  p.c. 
of  the  total  phosphorus  is  extracted  by  0*2  p.c. 
hydrochloric  acia  solution,  and  of  this,  nearly 
the  whole  exists  as  anhydro-oxymethylene  di- 
phosphoric  acid  CsHi,P,Ot 

=(OH),6pO-CH,-0-CH,-OPO(OH), 

a  substance  first  isolated  by  Postemak  (Revue 
General  de  Botanique,  1900,  12,  6  and  66 ; 
Compt.  rend.   1903.   137,  439).     In  bran,  this 


acid   exists  in  combination   with   magnesinm, 
calcium,  and  potassium. 

According  to  more  recent  views  (Anderson, 
J.  Biol.  Chem.  1916,  20,  463,  476,  483,  and 
493 ;  Robinson  and  Mueller,  Biochem.  Bull. 
1916,  4,  100 ;  Clarke,  Chem.  Soc.  Trans.  1916, 
360)  the  phosphorus  in  bran  is  mainly  in  com- 
bination witn  inositol,  the  triphoflphate 
CcHi,Oj.P,  and  the  hexaphoephate  Ccki^Ot^Og 
being  the  most  important.  Anderson  (/.r.) 
finds  that  wheat  bran  contains  about  0*1  p.c. 
of  inorganic  phosphorus,  i.e.  about  11  p.c.  of 
the  total  soluble  pnosphorus. 

The  free,  acid,  when  heated  with  mineral 
acids,  or  with  the  enzyme-phytase  (q.v.),  is 
hydrolysed,  yielding  inositol  and  phosphoric 
acid3C,H,P,0,-f-3H,0=C,Hi,0,+6H,P04. 

Bran  is  laigely  used  as  a  food  for  farm 
animals,  but  has  a  weakening  effect  upon 
digestion  if  used  in  laige  quantities.  It  is 
more  suitable  as  a  food  for  fattening  than 
for  working  animals.  Owing  probably,  to  its 
mechanical  action  on  the  bowels,  it  has  a'  purga- 
tive effect.  Jf  used  lan^ely  for  milch  cows,  it 
tends  to  make  the  butter  soft.  Similarly,  laige 
quantities  of  bran  given  to  fattening  uninnua 
tend  to  lower  the  melting-point  of  the  body-fat. 
This  is  an  advantage  in  the  production  of  mutton 
or  beef,  but  a  disadvantage  with  bacon. 

Bran  is  also  laigelv  used  in  tanning  leather. 
(For  a  description  of  the  process  and  of  the 
changes  occurring  in  the  fermentation  of  bran 
so  employed,  «ee  Wood  and  Wilcox,  J.  Soc. 
Chem.  Ind.  1893,  422,  and  1897,  610.)    H.  L 

BRAHDT.  {Mau-de-vu,  Fr. ;  Jirannttoein, 
Ger.)  The  term  'brandy'  is  an  abbreviation 
of  *  brandy- wine  *  the  original  Engli.ah  form  of 
the  word,  which  occurs  also  in  all  the  Teutonic 
languages  of  Northern  Europe,  and  signifies 
burnt  or  distilled  wine.  The  latter  term  (wine) 
in  its  widest  sense  includes  the  product  obtained 
by  fermentation  of  all  natural  fruit  juices  or 
extracts  from  grain,  and  not  fermented  grape 
juice  (mly.  CM  English  Acts  of  Parliament 
refer  to  'brandy '  ana  *  aqua  vit» '  made  from 
midted  com,  whilst  the  (German  word  brantU- 
wein  is  applied  to  strong  potable  spirits 
generally  without  implying  that  such  spirit  is 
necessarily  derived  from  wine.  At  the  present 
time,  however,  the  *  brandy '  of  commerce  is 
almoHBt  universally  understood  to  be  a  spirit 
derived  exclusively  from  the  grape. 

Besides  alcohol  and  water,  the  principal 
constituents  of  brandy  are  acetic,  butyric, 
oananthic,  and  valerianic  esters,  acetic  acid,  a 
small  quantity  of  a  volatile  oil,  and  a  little 
fixed  add,  tannin,  and  colouring  matter.  When 
new,  brandy  is  colourless,  but  gradually  acquires 
ayellowish-brown  colour  by  storaee  in  oak  casks. 
The  required  colour  for  particwar  brands  is, 
however,  usually  obtained  by  the  addition  of  a 
solution  of  caramel  or  burnt  sugar.  Genuine 
brandy  of  good  quality  has  a  sweet  mellow 
ethereal  flavour,  without  any  suspicion  of  the 
*  fiery '  or  *  earthy  *  taste  common  to  inferior 
or  fictitious  brandies. 

The  bouquet  of  brandy  depends  upon  (a)  the 
nature  and  quality  of  the  wme  from  which  it 
has  been  produced;  (6)  the  conditions  under 
which  the  wine  has  been  fermented;  (c)  the 
method  of  distillation  employed ;  and  (d)  the  age 
of  the  brandy.    The  oharaoieristio  flavour  of 


654 


BRANDY. 


hrandy  is  said  to  be  due  chiefly  to  oenftuthio 
ester  (ethyl  pelarsonate),  but  it  yaries  with  the 
total  amount  and  relative  proportions  of  other 
volatile  constituents  present.  Acoording  to 
Ordonneau,  the  peculiar  fragrant  odour  of 
brandy  is  due  to  a  very  smafi  quantity  of  a 
terpene  which  boils  at  178*,  and  which,  on 
oxidation,  gives  the  characteristic  flavour  to  old 
brandy. 

Over  90  p.c.  of  the  brandy  imported  into  the 
United  Kingdom  comes  from  France,  the  finest 
grades  being  Cognac  and  Artnagnac,  so  named 
from  the  Irench*  towns  in  which  they  were 
originally  distilled.  But  little  brandy  is  now 
distilled  in  Cognac  itself,  the  greater  part  being 
produced  on  the  brandy  farms  of  the  surrounding 
districts.  Other  brandies  of  less  value  commer- 
cially are  those  of  the  Midi  and  the  districts  of 
Aude,  Gard,  Herault,  and  Pyren^  Occidentales, 
commonly  known  as  the  ^Trois-siz  de  Mont- 
peUier.'  Marc  brandies  are  distilled  from  the 
fermented  *  marc  '  or  refuse  of  the  wine-press  as 
well  as  from  the  lees  of  the  wine-casks. 

Whilst  the  term  '  Cognac '  has  by  custom 
come  to  be  used  almost  as  a  generic  term  for 
*  brandy,*  it  is,  strictly  speaking,  applicable  only 
to  spirits  made  from  wine  grown  m  the  Cognac 
region,  which  comprises  a  certain  part  of  the 
two  departments  of  Charente  and  Charente 
Inf^eure,  also  Dordogne  and  Les  Deuz-Sevres. 
A  strict  delimitation  of  the  Cognac  arek  has 
been  made  by  the  French  Gfovemment  b^ 
decree  dated  Ist  Blay,  1909,  and  the  region  is 
locally  subdivided  into  the  Grande  or  Fine 
Champagne,  the  Petite  Champagne,  the  Borderies 
and  the  Bois,  according  to  the  quality  of  the 
wine  produced* 

The  soil  of  the  district  is  mainly  calcareous, 
and  the  grape  is  a  small  white  berry  with  very 
acid  juice,-  producing  a  wine  of  inferior  quality 
for  drinking  purposes.  (For  the  extraction  and 
fermentation  of  the  grape  juice,  see  Wiki.) 

As  the  reputation  of  the  brandies  of  the 
Cognac  and  Armagnac  districts  depends  so  much 
upon  their  bouquet,  they  are  submitted  to  slight 
recti flcation  only,  and  distillation  is 'therefore 
usually  conducted  in  a  simple  '  pot '  still  by  the 
professionil  distiller  as  well  as  by  the  farmer. 
The  still,  which  yaries  in  content  from  about 
160  to  200  gallons,  is  usually  enclosed  in  brick- 
work, with  only  a  small  bulbous  head  exposed, 
and  is  generally  heated  by  means  of  a  furnace, 
wood  toing  considered  the  best  fuel  In  a  few 
distilleries  the  stills  are  heated  by  steam.  Occa- 
sionally, a  subsidiary  vessel,  filled  with  wine  and 
called  a  *  chauffe-vm,'  is  attached  to  the  still, 
and  through  it  the  pipe  oonveyins  the  spirit 
vapour  to  the  refrigerator  passes,  neatmg  the 
wine  so  that  the  utter  is  quickly  raised  to 
boiling-point  when  subsequently  passed  into  the 
still,  thereby  effecting  a  saving  of  fuel.  Two 
distillationB  are  made,  termed  *  brouilhs '  and 
**  bonne-chauffe,'  corresponding  respectively  with 
the  *  low  wines '  and  spirits  '  of  the  whiskey 
distiller. 

In  some  distilleries  the  finished  spirit  is 
produced  at  one  continuous  distillation  by  means 
of  a  still  described  as  *  Ik  premier  jet.'  In  this 
form  of  still,  a  vessel  is  attached  to  and  above 
the  head  of  the  still,  and  through  it  the  spirit  of 
the  first  distillation  is  conveyed.  This  spirit  is 
ijkgain  vapourised  by  the  heat  of  the  spirit  vapour 


rising  from  the  still  itself  on  its  way  to  the 
refrigerator.    The  spirit  produced  in  this  way 
is  not  considered  so  fine  as  that  obtained  by  the 
pot  still,  but  it  is  of  higher  strength  and  more 
suitable  for  the  manufacture  of  liqueurs. 

The  quality  of  the  spirit  depends  greatly  on 
the  care  with  which  the  distillation  process  is 
carried  out.  The  stills  should  be  worked  slowly 
and  regularly,  the  normal  time  for  the  complete 
distillation  of  a  charge  being  about  ten  hours. 

The  quantity  of  wine  used  in  the  process  of 
manufacture  is  relatively  very  great,  the  amount 
of  brandy  produced  from  a  given  measure  being 
only  from  10  to  16  p.c.  The  strength  of  the 
wine  varies  from  4-6  to  9  p.c.  by  weight  of  pore 
alcohol,  or  approximately  from  10  to  20  p.c  of 
proof  spirit,  the  averajge  beinf  6-6  p.c.  of  afcohol, 
or  14  p.c.  of  proof  spirit.  I^e  finished  spirit  as 
run  from  the  still  contains  about  64  p.c  by  weight 
of  alcohol,  equivalent  to  a  strength  of  about 
26  over-proof.  The  brandy,  as  received  from 
the  farmers,  is  blended  and  diluted  in  vats, 
sweetened  with  cane  sugar,  slightly  coloured 
with  caramel,  and  filterra  (if  necessary)  into 
storage  vats  in  which  it  is  matured. 

The  French  Government  has  by  various  laws 
and  decrees  of  the  years  1906  to  1909  prohibited 
the  description  *  Cognac '  to  be  applied  to  any 
mixture  of  Cognac  or  other  wine  spirit,  with  grain 
or  beet  spirit,  and  has  further  provided  that 
labels,  marks,  &c.,  bearing  the  word  '  Gc^nao 
should  signify  that  the  spirit  in  question  is 
solely  the  product  of  the  Cognac  region  (vids 
supra). 

The  simple  pot  stills  and  the  modified  stills 
known  as  '  k  premier  jet,*  above  referred  to,  as 
bekiff  used  in  the  CSharento  districts,  are  not 
suitable  for  wines  having  a  strong  earthy  flavoar 
(*  terroir ')  or  other  undesirable  qualities.  In 
such  cases,  as  in  the  brandies  of  the  Midi,  the 
Rochelle  district,  and  the  marc  brandiee  of 
Burgundy,  stills  of  a  more  complicated  nature 
are  employed,  owing  to  the  necessity  for  a  greater 
degree  of  rectification.  In  these  the  distulation 
is  continuous,  and  in  the  Rochelle  district  and 
the  islands  of  the  N.W.  coast,  a  pot  still  with 
a  rectifying  head,  known  as  the  Alembic  dee 
lies,'  is  employed,  whilst  in  the  south  the 
distilling  column  consists  of  a  series  of  compart- 
ments separated  by  plates  or  *  plateaux,'  con- 
nected with  tape  by  means  of  which  it  is  possible 
to  t-ake  off  the  spirit  at  a  higher  or  lower  strength 
as  desired.  These  stills  are  generaUy  heated  by 
direct  fire. 

Immense  quantities  of  wine  are  produced  in 
the  Midi  for  conversion  into  brandy,  the  grapes 
of  this  region  being  unsuitable  for  making  sood 
wine.  This  is  attributed  to  tiie  effects  of  the 
PhyttoxerOf  which  devastated  the  whole  of  the 
Charento  district  in  the  years  1875-1878.  Before 
this  time,  most  of  the  brandy  exported  to  the 
United  Kingdom  was  genuine  Cognac,  but  the 
destruction  of  the  Charento  vineyams  stimulated 
the  production  of  brandy  in  other  parts  of  Franoe 
as  well  as  in  other  countries.  The  vineyards  of 
the  Cognac  district  were  replanted  with  American 
stocks,  on  which  Charento  vines  were  grafted, 
and  the  result  has  been  highly  successful ;  bat 
in  the  south  of  Fhuice  the  vineyards  ravaged  by 
the  phylloxera  were  replanted  with  vines  which 
were  not  appropriate  to  the  soil,  and  which 
yielded  wine  in.  great  quantity  but  at  the  aaorifioe 


BRANDY. 


655 


of  sood  quality.  Hence  the  use  of  the  rectifying 
stiSs  in  the  Midi  and  the  large  quantiW  of  brandy 
produoed.  Most  of  thia  is  consumed  in  France. 
The  spirit  deriyed  from  diseased  or  unsound  wines 
is  highly  rectified  and  used  for  industrial  pur- 
poses. The  cheapness  of  wine,  therefore,  affords 
tittle  or  no  inducement  to  the  distillers  of  the 
Midi  to  use  beet  or  grain  as  the  raw  material  for 
the  production  of  their  brandies. 

The  relative  values  of  the  spirits  above 
mentioned  may  be  gathered  from  the  average 
prices  per  proof  gulon  in  1909,  which  just 
oefore  the  war  (1914)  were  from  Is.  dd.  for 
brandy  of  the  best  Ck>gnao  district  (Champagne) 
to  3«.  for  Bois  brandy,  the  cheapest  m  the 
Coffnao  district,  whilst  Midi  branay  was  2s. , 
and  grain  and  beet  spirit  about  is.  Sd.  (f.  o.  b.) 
per  proof  ffaUon. 

Maro  brandies  or  eavx-de-vie  de  iikK-c  are, 
as  the  name  implies,  derived  from  the  maio  or 
refuse  of  the  grapes  after  the  juice  has  been 
extracted.  They  nave  a  strong  earthy  flavour, 
and  usually  are  very  rich  in  secondary  products. 
The^  are  therefore  often  added  to  other  wine 
spints  to  impart  the  brandy  character,  or 
admixed  with  neutral  spirit  nom  grain,  beet, 
Ac,  in  the  preparation  of  fictitious  brandies. 

Algerian  orandy  ia  of  high  quality,  resembling 
Cognac,  and  is  generally  sent  to  Fnnce,  whence 
considerable  quantities  are  reshh>ped  from  the 
Charente  district  to  the  United  kingdom. 

Brandies  are  produced  in  most  other  wine- 
growing countries,  especially  when,  owing  to 
over-production  of  wine,  or  some  defect  in  its 
quality,  it  becomes  more  profitable  to  convert  it 
into  spirit  than  to  dispose  of  it  as  *  wine.'  The 
most  important  commercially  are  from  Spain, 
Egypt,  (iermany.  South  Afnca,  and  Australia, 
but  the  quantities  of  these  exported  to  the 
United  Kingdom  are  small  as  compared  with 
French  brandies. 

The  Spanish  brandies  are  similar  in  character 
to  the  French,  and  command  a  high  price. 
Genuine  Egyptian  brandy  is  made  from  fresh 
grapes,  although  the  wine  grape  is  not  cultivated 
in  £^ypt.  The  grapes  are  imported  into 
Alexandria  from  Southern  Turkey,  Greece, 
Cyprus,  and  Asia  Minor,  and  there  made  into 
wine  from  which  the  brandy  is  distilled.  Thev 
have  a  strong  ohacacteristio  flavour,  much 
appreciated  by  consumers  of  the  cheaper  brandies. 
Spurious  brandies  of  doubtful  origin,  but 
described  as  *  ikmptian,'  are  also  on  the  market 
They  are  probably  made  from  the  currant  grape 
grown  in  Greece  and  Asia  Minor,  and  have  no 
right  to  the  title  of  *  E^ptian,*  beyond  the  fact 
thaX  they  are  exported  vid  Alexandria.  Increas- 
ing quantities  of  brandy  of  fair  quality  are  being 
produced  in  South  Africa  and  Australia.  The 
BO-oallod  'dop*  brandy  of  South  Africa  is 
produoed  in  the  same  way  as  the  French  *  maro  ' 
brandies,  and  has  similar  characteristics. 

The  natural  improvement  observed  m 
genuine  brandies  by  *  ageing  *  is  always  accom- 
panied by  a  rise  in  me  quantity  of  the  secondary 
constituents  due  to  the  formation  of  oxidation 
products  (aldehydes  and  acids)  and  esters,  as 
well  as  to  concentration  due  to  loss  of  alcohol 
and  water.  The  higher  alcohols  also  tend  to 
increase,  and  furfural  to  diminish,  with  age. 
Aooordinf^  to  Duplais,  the  mellowness  due  to  s«e 
may  be  imparted  to  new  brandy,  mM.lriTig  jt  fit 


for  immediate  use,  by  adding  the  following  to 
every  100  litres :  old  rum,  2*0  litres ;  old  kirsch, 
1-75  litres;  svrup  of  raisins,  2*0  litres;  and 
infusion  of  wamut  hulls,  0*75  litre.  Low  wines 
which  have  been  kept  for  some  months  in  casks 
containing  clear  rain- water  preserved  by  the 
addition  of  10  or  12  p.c.  of  strong  brandy  (85°) 
are  also  used  for  a  similar  purpose. 

Whilst  there  is  a  legitimate  use  of  colouring 
which  has  become  practically  an  essenUe^. 
character  of  the  brandy  of  commerce,  the  colour 
acquired  by  old  brandies,  owing  to  long  storage 
in  casks,  is  often  simulated  in  order  to  give  to 
new  brandies  a  fictitious  appearance  of  sge  by 
means  of  a  tincture  of  oak  extract  obtained 
from  chips,  shavings,  or  sawdust  of  the  white 
oak  used  at  Cognac  for  making  brandy 
casks. 

Brandy  was  formerly  described  in  the 
British  Pharmacopoeia,  as  *Spiritus  Vini  Gallici,* 
thus  implying  the  French  origin  of  the  spirit, 
and  was  defined  as  *  a  spirituous  liquid  distilled 
from  wine  and  matured  by  age,  and  containing 
not  less  than  36^  p.c.  by  weight,  or  43^  p.c. 
by  volume  of  eth^l  hydroxide  ^(approximately 
76  p.c.  of  proof  spirit). 

This  definition,  however,  takes  no  cognisance 
of  the  nature,  quantity,  or  relative  proportions 
of  the  secondary  products  to  which  we  peculiar 
medicinal  properties  of  brandy  are  attributed, 
and  in  view  of  the  variations  in  these  con- 
stituents even  in  the  brandies  of  commerce 
known  to  be  genuine,  and  the  difficulty  of 
arriving  at  any  satisfactory  standud,  the 
British  Medical  Association  eliminated  *  brandy  ' 
in  the  last  edition  of  the  British  Pharmacopoeia 
published  in  1914. 

The  following  standards  of  purity  are  pre- 
scribed by  the  united  States  Pharmacoposia. 
Brandy  snould  be  at  least  4  years  old;  its 
alcoholic  content  from  39  to  47  p.c.  by  weight 
(81-96  p.c.  British  proof  spirit) ;  specific  gravity 
not  exceeding  0*941  nor  less  than  0*925;  the 
residue  should  not,  on  the  volatilisation  of  the 
last  traces  of  alcohol,  evolve  a  marked  disagree- 
able odour  of  fusel  oil,  and  should  not  exceed 
1*5  p.c. ;  also  the  residue  from  100  c.c.  should 
dissolve  readily  in  10  c.c.  of  cold  water,  and 
should  be  free  from  moro  than  traces  of  tannin 
(t.e.  should  not  give  moro  than  a  pale-green 
colouration  on  the  addition  of  a  dilute  solution 
of  ferric  chloride) ;  and  the  acidity  should 
requiro  not  moro  than  1  c.c.  of  decinormal  alkali 
for  neutralisation  using  phenolphthalein  as  an 
indicator. 

Under  the  Sale  of  Food  and  Drugs  Act,  no 
standard  for  brandy  is  fixed  beyond  the  limita- 
tion of  strongth  (in  common  with  whiskey  and 
rum)  to  a  minimum  of  25  p.a  under  proof,  below 
which  it  may  not  legally  be  sold  without  tho 
fact  of  dilution  being  declared.  Thia  is  now 
(during  the  war)  superseded  hj  special  lesisla- 
tion,  iniioh  permits  of  spirits  being  reduced  to  a 
minimum  strength  of  50  p.c.  under  proof  and 
30  p.c.  under  proof  as  a  maximum  strength  at 
which  they  may  be  sold  as  a  beverage.  The 
strongth  of  brandy  as  imported  into  the  United 
Kingdom  varies  considerably,  but  the  average 
is  about  5°  below  proof,  or  46*5  p.c.  of  i^oohol 
by  weight. 

Or(u>nneau  (C!ompt.  rend.  102, 217)  subjected 
too  litres  of  25-year-old  brandy  to  fractional 


666 


BRANDY. 


distillation,  and  obtained  the  following  substance 
estimated  in  grams  per  hectolitre  : — 

Aldehyde 3*0 

Normal  propyl  alcohol  .  .40*0 

Normal  butyl  alcohol    .  .  218*0 

Amyl  alcohol  .         .83*8 

Hezyl  alcohol       .         .  .0*6 

Heptyl  alcohol      .         .         .         .1*5 

Acetic  ester  .         •         .         .35-0 

Propionio,  batyric,  and  caproic  esters     3^ 

CBnanthio  ester  (about)  .         .       4-0 

Acetal  and  amines  .         .     traces 


Morin  (Oompt.  rend.  105,  1010)  distilled  92 
litres  of  pure  cosnao  in  Claudin  and  Morin's 
apparatus.  The  mrst  portion  of  the  distillate 
contained  tho  more  volatile  bodies ;  the  second 
consisted  of  tolerably  pure  ethyl  alcohol ;  the 
third,  the  higher-boiling  alcohols,  &c.  The 
residue,  chiefly  water,  was  tested  for  free  acids, 
wobutylelycol  and  glycerol. 

The  nnt  three  portions  were  then  fraction- 
ated, 5  litres  of  liffht  alcohol,  65  litres  of  pure 
ethyl  alcohol,  ana  3*6  litres  of  higher-boiling 
compounds  being  obtained.  The  latter  fraction 
smelt  strongly  of  fusel  oil,  and  possessed  a 
burning  taste.  The  water  remaininff  behind  was 
added  to  that  already  obtained.  The  fractions 
were  then  redistilled  in  Le  Bel  and  Henninger's 
apparatus.  The  fusel  oil  portion,  which  after 
dehydration  by  potassium  carbonate  weighed 

362  grams,  gave : 

ffrains 
Water 7 


Ethyl  alcohol 
Normal  propyl  slcohol 
IsoYmtyl  alcohol 
Amyl  alcohol 
Furfural  •         • 

Wine  oils   . 


130 

25 

6 

176 
2 
7 


The  water  contained  a  little  acetic  and  butyric 
scids,  and  a  small  quantity  of  a  viscous  liquid 
which  distilled  undecompOEed  under  diminished 
pressure,  and  appeared  to  consist  of  isobutyl 
alcohol  and  glycerol  The  residue  contained 
tannin,  together  with  substances  extracted  from 
the  wood. 

In  the  following;  table:  1  shows  the  com- 
pounds contained  m  100  litres  of  the  cognac  ; 
2  shows  the  same  obtained  by  the  fermentation 

of  100  kilos,  of  sugar  : — 

1  2 

grams  grami 

Aldehyde       .         .          trace  trace 

Ethyl  alcohol         .     50,837-00  60,616-0 

Norm,  propyl  alcohol         27-17  2-0 

/sobutyl  alcohol     .             6-62  1-5 

Amyl  alcohol                    100-21  61-0 

Furfural  bases                     2-10  — 

WineoU        .                      7-61  2-0 

Acetic  acid    .                     trace  — 

Butyric  acid           .           trace  — 

isobutyl  glycol       .            2-10  ^ 

Glycerol        .         .            4-3S  — 

Butyl  alcohol  was  absent ;  furfural  was 
detected  directly  by  the  addition  o£  aniline  to 
the  cognac,  a  red  colouration  beine  produced 
in  the  presence  of  acetic  acid.  It  will  be  observed 
that  wobutyl  alcohol  is  present  only  in  small 
quantity,  whilst  in  Ordonneau's  results  it  is 
absent  altooether. 

The  analytical  data  usually  relied  upon  for 


discriminatinff  between  genuine  brandies  and 
those  blended  with  neutral  spirit  are  (a)  volatile 
acids;  (5)  aldehydes;  (c)  esters;  {d)  higher 
alcohols;  and  (e)  furfuraL  The  results  are 
calculated  in  parts  per  100,000  of  abedluto 
alcohol,  e.47.  in  millicrams  per  100  0.0.,  or.  srams 
per  hectolitre.  The  total  amount  of  the 
secondary  products  expressed  in  this  manner 
is  termeid  the  '  coefficient  of  impurities,'  or 
preferably  the  *  coefficient  non-aloohoL'  The 
standard  coefficient  suggested  by  Girard  and 
Cuniasse  for  genuine  brandy  is  300,  of  idiich  not 
ieis  than  80  would  be  eaters.  In  oalculatimt  the 
proportion  of  neutral  spirit  in  a  mixture,  aBow- 
anoe  should  be  made  for  the  small  amount  of 
secondary  products  present  in  neutral  spirit. 
The  average  coefficient  for  industrial  alcohol,  as 
shown  by  the  analyses  of  Girard  and  Cmuasse, 
is  17  and  the  esters  8. 

(For  a  detailed  description  of  the  methods  of 
analvsis  employed,  we  Thoipe,  Minutes  of 
Evidence  taken  by  the  Royal  Commission  on 
Whiskey  and  other  Potable  Spirits,  iL  Appen- 
dix Q,  xii  1000.) 

The  causes  which  affect  the  characteristic 
bouquet  of  the  wine  naturally  influence  the 
proportion  as  well  as  the  character  of  the 
volatile  matters  induded  in  the  '  coefficient '  of 
the  brandy.  Thus  the  proportion  of  acids  and 
esters  is  considerably  augmented  if  the  wine 
beoomes  sour,  and,  speaking  generally,  the 
aldehydes  are  higher  in  white  than  in  red  wines. 
Also  m  regard  to  distillation,  the  aldehyde  and 
more  volatile  esters  are  found  mainly  m  the 
flrst  runninffs  (*produit8  de  t^te'),  whilst  the 
higher  alcohols  and  furfural  occur  in  lamet 
quantity  in  the  tailinas  ('  produits  de  qaeoe  ). 

In  the  brandies  of  Gharente  and  Armagnao 
the  coefficient  is  usually  rather  high,  bat 
ordinarily,  in  cognacs  and  fine  champagne^  it 
ranges  between  275  and  460,  although  oooasion- 
ally  it  falls  considerably  beyond  weee  limits. 
Brandies  obtained  from  wines  of  the  Midi  and 
from  Algeria  show  much  wider  variations, 
ranging  mm  25  (indicating  strong  rectifioation) 
to  600.  Marc  brandies  have  almost  invariably 
a  very  hieh  coefficient,  ranging  from  500  to  neariy 
1500,  ana  in  these,  aldehydes  often  form  a  large 
proportion. 

Attempts  have  been  inade  to  fix  minimum 
and  maximum  values  for  the  coefficient*  but 
without  much  success,  the  former  with  a  view 
to  the  detection  of  the  admixture  of  neutral 
spirit,  and  the  latter  to  restrict  the  amount  of 
secondary  products  for  h wienie  reasons.  Hie 
effect  of  such  limits  would  be  to  condemn  many 
brandies  that  are  undoubtedly  genuine  and  even 
of  high  commercial  value. 

Srom  the  hygienic  point  of  view,  the  esters, 
furfural,  and  especially  the  aldehydes,  have  a 
much  more  deleterious  action  on  the  human 
system  than  the  higher  aJcohols,  whilst  the 
acids,  particularly  acel^c,  which  frequently  forms 
a  laige  proportion  of  the  coefficient*  cannot  be 
said  to  have  any  detrimental  influence. 

The  French  Government*  in  1004*  instituted 
inquiry  by  the    Technical   Oommittoe   of 


an 


(Enology  into  the  possibility  of  fixing  standaids 
for  the  total  amount  of  secondary  products 
(*ooefficient  non-alcohol')  of  genuine  brandy, 
but  the  conclusion  arrived  at  was  that  neither  a 
mipitmiTp  n<)^  maximum  limit  oould  be  reoom- 


BRAZILWOOD. 


657 


mended  owing  to  the  extremely  variable  character 
of  brandy,  not  only  with  respect  to  the  co- 
efficient aa  a  whole,  but  also  in  regard  to  the 
proportions  of  the  volatile  constituents  relatively 
to  each  other.  Chemical  analysis  should  not 
be  relied  upon  alone,  but  should  be  supplemented 
and  its  results  confirmed  by  expert  tasting 
{*  degustation  ')• 

British  brandy  is  usually  made  from  grain 
spirit  distilled  with  certain  flavouring  materials, 
or  by  adding  flavouring  ingredients  to  the  spirits. 
It  is  frequently  mixed  with  foreign  brandy,  and 
is  largely  used  for  cooking  purposes. 

Amongst  the  flavouring  ingredients  used  in 
the  manufacture  of  artificial  brandies  (including 
British  brandy)  may  be  mentioned  the  following  : 
oenanthic  ester,  tincture  of  catechu,  balsam  of 
tolu,  acetic  ester,  argol,  cognac  oil,  essence  of 
cognac,  infusions  of  oitter  almond  shells,  tea, 
and  walnut  huUs,  liquorice  root,  prune  juice, 
rum,  syrup  of  raisins,  vanilla,  &c.     So-called 

*  cognac  essences '  contain  mixtures  of  the 
aromatic    compounds   just    mentioned,    whilst 

*  cognac  oil '  ia  made  by  the  distillation  of  a 
mixture  of  alcohol,  coco-nut  oil,  and  sulphuric 
Acid,  oenanthic  ester  beine  one  of  the  products. 

Cider  brandy  is  manufactured  in  the  United 
States  and  Canada  from  cider  and  perry. 

Danzig  brandy  is  made  from  rye  ground  with 
the  root  of  CcJamus  aromatietts, 

Gawnsey  brandy  is  the  spirit  of  beet  root 
flavoured  to  imitate  true  brandy. 

Hamburg  brandy  is  said  to  consist  of  potato 
or  beet-root  spirit  as  a  basis,  flavoured  with 
es^ehces  or  by  the  addition  of  inferior  brandy, 
and  coloured  to  represent  genuine  brandy. 
Similar  imitation  brandies  appear  to  be  made  in 
the  north  of  France,  in  Belgmm,  and  in  other 
foreign  countries.  (Girard  and  Cuniasse,  Man. 
pratique  de  FAnalyse  des  Alcools  et  des  Spi- 
ritueux ;  Schidrowitz,  Analyst,  June,  1906,  and 
June,  1006;  Thorpe,  Nature,  3  Nov.  1904; 
and  Report  of  Royal  Commission  on  Whiskey 
and  other  PoUble  Spirits,  190S-9.)  J.  C. 

BRASS  V.  Znro. 

BRASSIC  ACID  v.  Brassidio  acii>. 

BRASSIDIC  ACW  (Brassic  acid) 

cji,^^-^<Cci,H„-co,n 

13  isomeric  with  erucio  acid  (g.v.),  from  which  it 
may  be  obtained  by  the  action  of  nitrous  acid 
(Haussknecht,  Annalen,  143,  54;  Reimer  and 
Will,  Ber.  1886,  3321 ;  Websky,  Jahrb.  Chem. 
1853,  444 ;  Fitz,  Ber.  1871,  444) ;  b^  treatment 
with  hydrogen  bromide  in  acetic  acid  solution, 
monobromlMhenic  aoid  Cs|H4.0|Br,  being  also 
formed  (Ponzio,  Gazz.  chim.  ital.  35,  ii.  394) ;  and 
by  heating  with  concentrated  sulphurous  acid 
at  200*  (M.  K.  and  A.  Saytzew,  J.  Russ.  Phys. 
Chem.  Soc.  24,  482 ;  J.  pr.  Chem.  50,  [2]  78). 
It  may  also  be  obtaiued  by  heating  behenolic 
acid  with  zino  and  acetic  acid,  and  a  few  drops 
of  hydrochloric  acid  (Holt.  Ber.  1982,  962),  and 
by  the  reduction  of  monobrombraasidic  acid, 
which  is  obtained  by  treating  behenolic  aoid  with 
hydrogen  bromide  (Hasse  and  Stutzer,  Ber. 
1903,  3601).  Brassidio  acid  orystallisea  from 
alcohol  in  plates,  m.p.  65*-66*  (Saytzew,  Lc), 
b.p.  282*  (30  mm.),  265*  (15  mm.),  256*  (10  mm.), 
180*  (0  mm.),  (Krafft  and  Woilandt,  Ber.  1896, 
1325);  8p.gr.  0-8585  at  57  r/4*;  is  less  soluble 
Vol.  t—T. 


than  erucio  acid  in  alcohol  and  ether.  (For 
relationship  to  erudc  acid  and  comparison  of  their 
behaviour  towards  various  reagents,  v.  Albitzirjr, 
J.  Russ.  Phys.  Chem.  Soc.  31,  76;  34,  788; 
J.  pr.  Chem.  61,  [2-3]  65;  Maaoarelli,  Atti.  R. 
Accad.  Lincei,  1917,  [v.]  26,  i.  71).  By  fusing 
brassic  add  with  potash,  aracMdic  acid  Cf,oH«eO| 
is  obtained  (Goloschmidt,  Jahrb.  Chem.  1877, 
728) ;   oxidation  with  potassium  permanganate 

S'elds  a  dihydroxybehenic  add  (Jukovuy,  J. 
uss.  Phys.  Chem.  Soc.  24,  499  ;  Albitzlcjr,  /.c). 
Treatment  with  hydriodic  acid  in  gladal  acetic 
acid  yields  iodobehenic  acid  (Bayer  and  Co., 
D.  R.  P.  180087  ;  Chem.  Soc.  Abst.  1907,  i.  380). 

BRASSIL.    A  local  name  for  iron  pyrites. 

BRASSTUC  ACID  C,,H,«0«.  Obtained, 
together  with  other  products,  by  acting  on 
behenolic  acid  G^^H^qO^,  with  fuming  nitric  acid 
(Haussknecht,  Annalen,  143,  45 ;  Grosamann, 
Ber.  1893, 644).  May  be  prepared  by  the  action  of 
nitric  acid  on  erucic  acid  (Fileti  and  Ponzio,  Gazz. 
chim.  ital.  23,  ii.  393),  and  from  iir-undecenoic 
acid  (Krafft  and  Seldis,  Ber.  1900,  3571).  Flat 
needles;  m.p.  11.3°- 1 14°;  readily  soluble  in 
alcohol  and  ether,  sparingly  soluble  in  water. 

BRAUNITE.  A  manganese  mineral  classed 
with  the  oxides,  but  containing  an  appreciable 
amount  of  silica  (8-10  p.c.),  the  formula  being 
8Mn,0,;MnSiO,  or  4Mn,0,*MnSiO|.  The  man- 
ganeee  is  usually  isomorphously  replaced  by  small 
amounts  of  iron,  calcium,  barium,  Ac.  It  ii 
generally  found  in  compact  maflaaa,  but  sometimes 
as  tetn4;onal  pyramids,  the  angles  of  which  are 
very  near  to  those  of  the  regular  octahedron. 
The  crystals  possess  a  perfect  pyramidal  cleavage. 
The  colour  is  olaok  with  a  sub-metallic  to  met^o 
lustre.  Sp.gr.  4*8 ;  H.  6-6}.  The  mineral  is 
found  in  tne  manganese-mines  in  Sweden  ;  and, 
with  the  exception  of  psilomelane,  it  is  the  most 
abundant  of  the  manganese  ores  in  India  {v. 
L.  Ifc  Fermor,  Mem.  Geol.  Survey,  India,  1909, 
xxvii).  L.  J.  S. 

BRAZILTTE.  A  synonym  of  baddeleyite 
iq.v.).  The  same  name  has  also  been  applied 
to  an  oil-bearing  rock  from  Bahia,  Brazil. 

Ij.  J.  S. 

BRAZIL  NUTS  are  the  fruits  of  BerthoOetia 
exceUa  (Humb.  and  Bonp.).  They  yield  73  p.c. 
of  a  fatty  oil  of  pale  yellow  colour,  of  a  taste 
similar  to  that  of  the  nuts  themselves.  In 
South  America  an  edible  oil  is  expressed  from 
the  fresh  nuts,  but  the  oil  known  m  Europe  is 
derived  from  mouldy  nuts,  and  is  only  fit  for 
the  manufacture  of  soap.  The  oil  deposits  a 
large  amount  of  '  stearine  '  on  standing.  It  is  a 
'  semi-drying  '  oil ;  iodine  value  about  106  ; 
m.p.  of  fatty  acids  28''-30''  (De  Nc^ri  and 
Fabris).  J.  L. 

BRAZILEITO.  An  inferior  kind  of  Brazil- 
wood obtained  from  CcBsalpinia  hratilienai4 
(Unn.),  nowing  in  the  West  Indies, 

BRAZlLW<K>D.  Under  the  name  of  Brazil- 
wood  certain  varieties  of  the  so-called  '  soluble  ' 
red  woods  are  known,  the  term  *  soluble  '  being 
employed  to  distinguish  them  from  the  dye- 
stuffs  of  the  barwood  dass,  which  only  with 
difficulty  yidd  their  colouring  matters  to  boiling 
water.  These  soluble  red  woods  give  with 
aluminium  mordanted  fabrics,  a  bright-red  shadeg 
which  in  each  case  is  derived  from  one  and  the 
same  colouring  matter,  and  all  are  botanicaUy 
allied,  in  that  they  consist  of  the  wood  of  various 

2u 


658 


BRAZILWOOD. 


spedoB  of  Casalpinia.  About  nine  Tarieties 
have  been  employed  aa  dyeeta&,  of  which  the 
following  are  tne  best  known : —  * 

Femambueo  or  Pemambuco  wood  is  considered 
to  be  the  richest  in  colouring  matter,  and  is  the 
product  of  the  Ccesalpinia  crista,  a  troe  which  is 
abundant  in  Jamaica  and  Brazil. 

The  true  Brazilwood  is  derived  from  the 
Ccualpinia  hrazUiensis,  and  is  said  to  contain 
only  one-half  the  colouring  matter  which  is 
present  in  the  Femambueo  variety.  It  is 
obtained  exclusively  from  Brazil. 

Sappanwood  is  obtained  from  the  CcBsalpinia 
iappan,  a  tree  which  is  common  to  the  warmer 
regions  of  Asia.  The  so-called  Limawood  is  a 
variety  of  sappan,  and  the  dyewood  imported 
from  the  Philippine  Islands  is  an  inferior  quality 
of  this  product. 

Peachwood  is  the  product  of  the  CcMolpinia 
echinaia,  which  occurs  in  Central  America  and 
the  nortiiem  parts  of  South  America. 

These  woods,  which  are  very  hard,  and  of  a 
deep-red  colour,  come  into  the  market  in  the 
form  of  billets  varying  in  weight  from  a  few 
pounds  up  to  a  hundredweight.  If  freshly  out, 
the  internal  colour  of  the  wood  is  seen  to  be 
light-yellow,  but  this  soon  changes  to  deep-red 
in  contact  with  air. 

Some  varieties  of  these  woods  were  employed 
for  dyeing  purposes  in  India  long  before  the 
discovery  of  America,  and  it  is  stated  that  when 
South  Ainerica  was  discovered  by  the  Spaniards, 
in  1600,  the  northerly  portion  of  the  country 
was  named  Brazil  (from  hraxa,  fiery  red),  because 
this  red  dyewood  was  found  there  in  such  im- 
mense quantities. 

Owing  to  the  fugitive  character  of  the 
colours  yielded  by  Brazilwood,  it  is  now  only 
employed  to  a  somewhat  limited  extent. 

Braxilin  0i,H|40,,  the  colouring  principle  of 
Brazilwood,  was  first  isolated  in  a  orystalline 
condition  by  Chevreul  (Ann.  Ctdm.  Pays.  [11 
66,  225) ;  but  was  not  further  examined  until 
1864,  when  Bolley  (Schweiz.  polv.  Zeitsch.  ix. 
267)  assigned  to  it  the  formula  C,,H.oO, 
Subsequently  Kopp  (Ber.  6,  446)  proposed  the 
formula  O^Jlifiy,  out  it  was  left  to  Liebermann 
and  Bui:^  (Ber.  9,  1883)  to  determine  the  exact 
composition  of  this  substance,  and  their  formula, 
CjcHiaO.,  is  in  use  at  the  present  time.  To 
prepare  brazilin  from  the  wood  itself,  it  is  best 
to  employ  the  commercial  extract.  This  is 
stirred  up  with  a  considerable  quantity  of  sand, 
the  product  extracted  with  cold  ether,  the 
ethereal  liquid  evaporated  to  a  small  bulk, 
treated  with  a  little  water,  and  allowed  to  stand 
for  some  days.  Crystals  slowly  separate,  and 
these  are  purified  by  crystallisation  nom  a  little 
water. 

This  method  is,  however,  tedious,  and  the 
usual  source  of  bntzilin  consists  of  the  crude 
crystalline  crusts  of  this  substance  which  are 
frequently  deposited  from  Brazilwood  liquor, 
an  intermediate  product  in  the  manufacture  of 
Brazilwood  extract.  The  crude  substance  is  best 
purified  by  two  or  three  crystallisations  from 
water,  to  which  a  little  sulphurous  acid  has  been 
added  (Gilbody,  W.  H.  Perkin,  and  Tates,  Chem. 
Soc.  Trans.  1901,  79, 1396).  Brazilin  crystallises 
in  two  forms,  either  as  colourless  needles  contain- 
ing l^HtO,  or  as  colourless  jprisms  with  1H,0. 
It  is  readily  soluble  in  aloonol  and  water,  and 


dissolves  in    a  dilute  solution  of   sodium  car- 
bonate with  a  beautiful  carmine-red  colour. 

Teiraacetylbrazilin  C,«Hi«0,(C,H,0)4,  colour- 
less  needles,  m.p.  149°- 151°  (Liebermann  and 
Buic) ;  triacetyfbrazOin  C,«H,i0|(C,H,0)„ 
needUes,  m.p.  105°-106°  (Buchka  and  Erck,  Ber. 
18,  1139) ;  orowbrazilin  Ci^Hi^rOt^  brown-red 
leaflets  (B.  and  E.) ;  dibronArazUin  C,cH|sBr,0„ 
leaflets  (Schall  and  Dralle,  Ber.  23,  1560) ;  teira- 
acetylbrombraziUn  Ci«H,)Br,0((CtH,0)4,  needles, 
m.p.  203°~204°  (Buchka,  Annalen,  17,  685); 
Utraacetyldibronibrazain  Oi«H,Br,Os(CtH,0)«, 
m.p.  185°  (S.  and  D.) ;  tribronJbraztlin 
Ci^nBr,0,  (S.  and  D.) ;  diehhrbrazain 
C,eHj|Cl,0s  (L.  and  B.) ;  and  tetrabrombrazUin 
Gifiifirfif,  fine  red  needles  (B.  and  £.)  have 
beenprepared. 

when  brazilin  is  methylated  with  methyl 
iodide  in  the  usual  manner,  it  gives  hraziUn 
Irimethyl  ether  (S.  and  D.,  Ber.  20,  3365  ;  Heizig, 
Monatsh.  14,  66;  and  Schall,  Ber.  27,  526) 
CuHii0a(00H,)„  prisms,  m.p.  138°-139°,  which 
on  acetylation  yields  acetylbraziUn  trimethyl 
ether  Ci,HioO,(OCH,),(C,H,0),  m.p.  171°-17r 
(Herzig,  Monatsh.  16, 140 ;  SchaU,B6r.  27, 236). 

According  to  Gilbody,  W.  H.  Perkin,  and 
Yates  (Chem.  Soc.  Trans.  79,  1403),  lan^e 
quantities  of  the  trimethyl  ether  are  convenienuy 
prepared  as  follows:  143  grams  of  brazUin 
dissblved  in  the  smallest  possible  quantity  of 
methyl  alcohol  are  treatea  with  35  grams  of 
sodium  in  methyl  alcohol  and  methyl  iodide 
(250  grams),  and  the  mixture  is  heated  50  hours 
to  6(r-65°  in  absence  of  air.  •  A  second  method 
employed  also  by  v.  Kostanecki  and  Lampe 
(Ber.  36,  1669)  consists  in  methylatins  braailm 
with  excess  of  dimethyl  sulphate  and  sikali. 

The  difficulty  experienced  in  fuUy  methylat- 
ing  brazilin  is  evidence  of  the  presence  of  an 
alcoholic  group ;  but  the  tetramelhyl  ether 
Ci«HioO(OCH,)4,  m.p.  137°-139°,  has  been  pre- 
pared by  Schall  by  treating  the  sodium  com- 
pound of  the  trimethyl  derivative  suspended 
in  benzene  with  methyl  iodide  at  120°  (oomi>are 
also  Herzig,  Z.e.).  From  this  substance  the  fdlow- 
ing  derivatives  have  been  prepared : — 

BrombrazUin  tetramelhyl  ether  Ci.HtB'O* 
(OCH,)«,  prisms,  m.p.  180°-181°  (S.  and  B.,  Ber. 
21,  3014) ;  and  dibironibrazUin  tetramethyl  eiher 
C,,H,Br,0-(0CH,)4,  m.p.  216°  (S.  and  D.  Ber. 
23,  1432). 

When  brazilin  is  submitted  to  dry  distiUallon, 
it  ffives  resorcin  (Kopp,  Ic),  and  by  fusing  it 
witn  potassium  hydroxide,  Liebermann  and  Bug 
obtained  resorcin,  and  Herzig  (Monatsh.  27, 739) 
also  vrotocaUehuic  acid.  With  nitric  acid  brazilin 
yields  trinitroremrcinol  (Reim,  Ber.  4,  334). 

When  brazilin,  the  colouring  principle,   is 
oxidised  under  suitable  conditions,  it  is  oonvorted 
into  brazilein,  the  true  colouring  matter 
CuHi40,-f0=Ci,H,;q,-f-H,0 
and  for  tms  purpose  the  action  of  air  on  aa 
alkaline     brazilin    solution,     alcoholic     iodine 
(Liebermann  and  Bui^),  potassium  nitrite,  and 
acetic  acid  (SchaU  and  Ihralle),  nitric  acid  in 
the  presence  of  ether  (Buchka  and  Erck),  and 
sodium   iodate   (Mayer,    Zentr.    1904,   L    228) 
have  been  employed.    It  can,  however,  be  move 
economically  prepared  from  Brazilwood  extract 
in  the  following  manner  (Humm^  and  A.  G. 
Perkin,  Chem.  Soc.  Trans.  1882,  41,  367)  :— 
To  an  aqueous  solution  of  the  extract  of  tlia 


BRAZILWOOD. 


659 


wood,  an  excem  of  ammonia  is  added,  and  air  is 
aspirated  through  the  liquid.  A  precipitate  of 
the  impure  ammonium  salt  of  braziuen  gradually 
separates,  and  this  is  collected,  disrolved  in 
hot  water,  and  treated  with  dilute  acetic  acid 
(8p.gr.  1'04).  A  brown  viscous  precipitate  of 
the  crude  colouring  matter  is  thus  obtained, 
which  is  extracted  with  hot  dilute  acetic  acid, 
and  the  extract  evaporated  on  the  water-bath. 
Crystals  of  brazilein  separate,  which  are  collected 
and  washed  with  acetic  acid. 

Brazilein  consists  of  minute  plates  possessing 
a  strong  metallic  lustre,  and  by  tnnsmittea 
light  a  reddish- brown  colour.  It  is  very  spar- 
ingly soluble  in  all  the  usual  solvento,  and 
cannot  be  recrystallised  in  the  ordinary  manner. 
It  is  in  reality  the  colouring  matter  of  Brazil- 
wood, and  possesses  strong  tinctorial  property. 
Alkaline  somtions  dissolve  it  with  a  deep-red 
colouration,  which  on  standing  in  air  nasses 
gradually  to  brown.  A  study  of  this  oxidation 
was  carried  out  by  Schall  and  Dralle,  with 
interesting  results.  2*7  grams  of  brazilin  dis- 
solved in  150  C.C.  of  water  was  treated  with  10 
C.C.  of  sodium  hydroxide  solution  (8p.ffr.  1*37), 
and  air  aspirated  through  the  liquid  for  36  hours. 
Ether  extracted  from  the  acidified  solution 
^resorcylic  acid,  and  a  *  substance  C«H(04, 
oryBtaUising  in  brownish-yellow  needles,  m.p. 
271%  which  gave  a  (itace<y2  compound,  m.p.  148 - 
149*",  and  a  dimethyl  ether,  m.p.  IdO'^-HO^. 
When  the  latter  was  oxidised  in  acetic  acid  solu- 
tion, with  potcMsium  permanganate  fi-ruofcylic 
acid  monomethyl  ether  was  produced  : 

CH,0/\0H 
l^^COOH 

Schall  and  Dralle  considered  that  this  com- 
pound was  probably  apheno-7»pyrone  derivative, 
and  Feuerstein  and  Kostanecki  (Ber.  32,  1024) 
proved  that  this  was  in  reality  the  case,  and 
assigned  to  it  the  following  constitution  : — 

y' 11 — 


\/\        /COH. 

xo^ 

Thus  the  dimethyl  ether,  when  hydrolysed 
with  alcoholic  potash,  gave  fisetol  dimethyl  ether 

CHjOf^OH 

IJC0-CH,*0CH, 

a  subfltanoe  which  had  already  been  obtained 
in  a  similar  manner  by  Herzig  ^m  fisetin  tetra- 
methyl  ether  (see  Toung  Fustic). 

(>ur  chief  knowledge  of  the  constitution  of 
braadlin  is  due  to  the  elaborate  investi^atiouB  of 
W.  H.  Perkin  and  his  pupils,  who  obtamed  most 
important  results  by  the  oxidation  of  brazilin 
trimethyl  ether  with  potassium  permanganate, 
and  alao  with  chromic  acid. 

Gilbody,  Perkin  and  Yates  (CSiem.  Soo. 
Trans.  1001,  70,  1465)  found  that  when  brazilin 
trimethyl  ether  is  oxidised  with  permanganate,  it 
gives,  in  addition  to  oxalic,  acetic,  and  formic 
aoids,  the  following  compounds  :-— 

1.  m-Hemipinie  aeid 

CHjOf^COOH 
CHjOl     JCOOH. 


The  isolation  of  this  substance  was  important, 
since  it  showed  that  brazilin  contains  a  catechol 
nucleus  and  two  orthohvdroxyls,  and  as  a  result 
of  these  latter  no  doubt  in  part  its  tinctorial 
properties  are  due. 

2.  2'Carboxy'6-mei7uKeyphenoxyaeetic  aeid 

CH,o/\o*CH,CO,H 
'\^'C0,H. 

On  fusion  with  alkali,  this  compound  yields 
resorcinol,  and  on  heating  with  water  to  200* 
is  converted  into  methoxyphenoxyacetic  aeid 

CH,0/\0*CH,C00H 

This  can  be  syntheaised  by  the  interaction  of 
ethylbromacetate  and  the  sodium  compound 
of  resorcinol  monomethyl  ether  and  sobeequent 
hydrolysis. 

3.  BrazUic  acid 

%,o/\r^^^,cn. 

[^\      ^(0H)*CH,-C00n 

when  fused  with  alkali,  gives  resoroin,  and  on 
warmine  with  sulphuric  acid  is  converted  into 
anhydroorazilie  actd 

Ov/ 

CHaOl 


lJ\^'(^CH..COOH 


Boiling  baryta  water  hydrolvses  anhydrobrazilio 
acid,  with  production  of  formic  aeid  and 
Q'hydroxy'4,'4nethoxybenxoylpropionie  aeid 


CH 


•«rt^ 


.      J— 00— CH,— CH  j-COOH 

On  methylatton  this  is  converted  into  the 
dimethyl  ether,  and  the  latter  can  be  produced 
by  the  interaction  of  dimethyl  resorcinol  and 
the  half-chloride  of  st^cinic  acid  monoethyl 
ester,  and  subsequent  hydrolysis.  It  is  also 
formed  when  resorcinol  dimethyl  ether  and 
succinic  acid  are  treated  with  aluminium  chloride 
without  emploving  a  solvent. 

Finally,  when  the  methyl  ester  of  this 
hydroxymethoxybenzoylpropionic  acid  is  dis- 
solved in  ethyl  formate  and  treated  with  sodium, 
the  fi^yl  ^ttter  of  anhydr6bra;gilic  acid  is  pro- 
duced. This  interesting  synthesis  may  be  repre- 
sented as  follows : — 

CH,o/N-OH 

I  i— CO— CH,CH,OOOCHg 

CH,o/V-OH  CHOH 


[  ^j— 00- 


0 


CH,0 


0— CHjCOOCHg 


.C— CH,*COOCH,. 


Dimethoxycarboxybenzylformie  acid  (I),  and 
dimethoxyca  ooxybewBoytformic  acid  (2). 


COOH- 


[/N-o( 

)IJ=0( 


represent  intermediate  stages  in  the  formation 
of  fA-hnnipinio  add  from  brazilin  trimethyl 
etheTp  whereas  the  add 


060 


BRAZILWOOD 


OH,o/V-0— CH.CH(OH)COOH 
'vjCOOH 

also  isolated,  is,  no  doubt,  that  product  of  tbe 
oxidation  which  U  anterior  to  the  formation  of 
carboxymethoxyphenoxyaoetio  acid  {see  above). 

The  earlier  work  suggested  the  following 
probable  constitution  for  brazilin : — 

Oh/V-0 CH /\0H 

I      LcH(OH)-CH-CH,-I^^OH 

but  this,  as  a  result  of  the  investigation  of 
brazilinic  acid,  a  very  important  substance, 
also  produced  by  the  oxidation  of  brazilin 
trimethyl  ether,  was  subsequently  discarded. 

Brazilinic  acid.  The  constitution  of  this  acid 
has  been  conclusively  demonstrated  by  its  synthe- 
sis, which  has  been  effected  by  the  interaction  of 
m-hemipinio  anhydride  with  ethyl  methoxyphen- 
oxyacetate  in  the  presence  of  aluminium  chloride. 
This  is  illustrated  by  the  following  equation  :— ■ 

CH  ,o/^— O— CH,<X)OEt 


OCH,  OCH, 
CH,o/^0— CH,<X)OH 


Iv 


1— CO 


/ 


OCH,  OCH,. 
BraztUnic  acid. 

When  brazilinic  acid  is  reduced  with  sodium 
amalgam,  it  is  .quantitatively  converted  into 
dihy&obrazilinic  acid  Ci,H,oO„  which  at  once 
loses  water  with  the  formation  of  the  lactone 
Oi,H|,0,. 

To  synthesise  the  latter  compound,  m-hemi- 
pinic  annydride  is  condensed  with  resorcinol  di- 
methyl ether  to  form  2-hydroxff'4.6'A'4rimeihoxy 
benzoyWemoic  acid 

CHjO./^OCH,     ,    r.^o-(^,o(m^ 

'   IJ  +     ^"^CO— t^OCH, 

CH,o/N— OH  cooh/Noch, 

I) CO ^l^OCH,, 

When  reduced  with  sodium  amalgam,  this 
acid  gives  2-m-meconyl-5'methcxyphenol  (1), 
and  th»  by  the  action  of  chloraoetic  acid  and 
potassium  hydroxide  is  converted  into  the 
lactone  of  dihydrobrazilinic  acid  (2) 

CH,( 


(1) 


(3) 


H  O^^^V-O— CH,-OOOH 
L    J— CHOH  OOOH 

CHjO     OCH,. 
DihydrobrazOinio  acid  itself  ia  aocordingly 
represented  by  formula  (3). 
The  following  constitution  :— 

O 

OH,^YV®« 
y^(OH) 


(2) 


I  j— ch/  N:;o 
obn;    OCH, 


HO       OH. 

has,  as  a  result  of  this  work,  been  assigned  to 
brazilin  by  Perkin  and  Robinson  (Chem.  See 
Trans.  1908,  93,  496),  and  is  in  complete  har- 
mony with  the  facta  above  enumerated. 
Oxidation  of  triweihylbraziUn  wiOt  chromic  acid 
When  trimethylbrazilin  is  oxidised  with 
chromic  acid  it  is  converted  into  Wimihyl' 
hrazilone  (Gilbody  and  Perkin.  v.  infra}— 

and  this  apparently  simple  reaction  has  proved 
to  be  of  an  extremely  puzzling  character. 

When  trimethylbrazilone  is  oxidised  with 
permanganate,  it  gives  mhemipinic  acid,  2- 
carboxy  •  6  '  methoxyphenoxyacetic  actd,  br^Ote 
acid,  dimethoxycarboxybenzoylfortnic  aeid^  ^me- 
ihoxycarboxybenzylformic  acid,  methoxycarooxy' 
phenoxylactic  acid,  Mid  brazUinic  acid. 

In  an  earUer  paper.  GUbody  and  Piwkm 
(Chem.  Soc.  Trans.  1902,  81,  1040)  suggested  for 
trimethylbrazilone  a  constitution  baaed  upon 
their  first  formula  for  brazilin  («c  above),  but  it 
was  subsequently  shown  {ibid.  1908, 93, 498)  that 
the  reaction  proceeds  as  follows :  By  the  oxida- 
tion  of  trimettiylbrazilin  (1)  with  chromic  a«id  a 
disruption  of  the  central  linkage  occurs,  with  the 
formation  of  an  unstable  diketone  (2),  and 
this  subsequently  undergoes  aldol  condensation, 
and  trimethylbrazilone  is  produced  (3) — 

CH,0/\^^^-<JH, 


CH,0/\^^\GH. 

C(OH) 


(1) 


(2) 


\/\oo 


<; 


(3) 


I  r 

OCH,    OCH,         och; 

CH.o/V^^CH<X) 


CH, 


"Oct, 


C(OH) 


OGSi      5CT, 


This  formula  represents  trimethylbrazilone 
as  a  derivative  both  of  coumaran  and  tetrahy- 
dronaphthalene,  and  affords  a  ready  explanation 
of  the  decomposition  products  of  this  compound. 

An  important  pomt  in  favour  of  thw  ooo- 
stitution  is  afforded  by  the  behaviour  of  trimethyl- 


BRAZILWOOD. 


061 


brazilone  with  alkalis,  or  acetic  anhydride  and 
other  dehydrating  M^ents,  for  it  is  thus  converted 
with  loss  of  one  mofecule  of  water  into  anhydro- 
trimethyUjrazilone  (CH,0),0,.H70a.  There  can 
be  little  doubt  that  the  formation  of  this  sub- 
stance is  due  to  the  elimination  of  water  from 
the  aldol  grouping  in  trimethylbrazilone,  and 
that  it  possesses  the  following  formula : 


CH, 


V' 


\ 


0 


< 


C— COH 
CH 

\ 
"OCH, 


^v 


OCH, 

Anhydrotrimethylbrazilone  is  thus  a  deriva- 
tive of  fi-naphthoi,  and  it  possesses  manv  of  the 
properties  of  this  su  bstanoe.  It  is  soluble  m  dilute 
alkali,  and  this  solution  gives  with  diazobenzene 
chloride  a  red  azo-  dyestuff.  Diazonaphthalene 
chloride  behaves  similarly,  and  the  dye  thus 
produced  dissolves  in  sulphuric  acid  with  a  blue 
colour. 

When  trimethyl brazilone  is  boiled  in  acetic 
acid  solution  with  phenylhydrazine,  deoxytri' 
methytbrazilone  CicH.O,(CH,0),  is  obtained, 
and  this  is  probably  a  cQhydronaphthalene 
derivative  of  the  formula 

OCH,  OCH, 
The   most  striking   reacSon  of  trimethyl- 
brazilone  is  its  behaviour  with  nitric  acid,  when 
it  yields  a  compound  possessing  the  composition 
of  a  nilrohydroxydihyarotrimeikylbrtizilone 

Ci,H,0,(CH,0),+HNO,  =  CuHioO,N(CH,0), 

This  substance  dissolves  in  alkali  with  a 
purple  colour,  but  on  standing  the  colour  rapidly 
lades,  o-nitrohon^veratrol  separates,  and  the 
solution  contains  p-methozywUicylic  acid.  Oxi- 
dation with  permanganate  gives  2-carhoxy-5' 
meihoxy]phtnoxyaceiic  acid,  and  these  decom- 
positions point  clearly  to  the  formula 

CH,0^^\jH,       OgN'^.OCH, 

C(OH)-CH,!      'oCH, 

as  representing  the  constitution  of  this  nitro- 
compound. (See  aUo  Perkin  and  Robinson, 
ibid,  1909,  96,  381.) 

Feuerstein  and  v.  Kostaneckl  (Ber.  32,  1024) 
assigned  at  first  the  following  constitution  to 
brazilin : — 

OH^  ^-^  ^^CU 

I 
COfl 


which  was  based  upon  the  production  from  it  of 
dihydrozypheno-v-pyrone  (Schall  and  Dralle) 
by  alkaline  oxioation,  and  of  protocatechuic 
acid  by  fusion  with  alkali  (Herzig). 

It  was,  however,  pointed  out  by  Perkin 
that  this  formula  does  not  account  for  the 
presence  of  fn-hemipinic  acid  among  the  oxida- 
tion products  of  trimethylbrazUin,  and  Herzis 
and  PoUak  (Monatsh.  1901,  22,  207)  advanced 
a  similar  criticism*  On  the  other  hand,  it  was 
suggested  at  the  time  by  v.  Kostaneckl  and 
Lampe  (Ber.  1902,  35,  1667)  that  m-hemipinio 
acid  was  not  to  be  regarded  as  an  oxidation 
product  of  trimethylbrazilin  itself,  but  that  it 
arose  from  the  formation,  during  the  oxidation, 
of  a  phenanthrene  or  indene*  derivative,  which 
by  the  further  action  of  permanganate  gives 
this  acid.  Such  an  indene-condensation  is 
illustrated  by  the  following  scheme,  which, 
according  to  these  authors,  probably  occurred 
during  the  formation  of  trimetbylbrazilooa  from 
trimethylbrazilin. 

The  first  product  of  the  oxidation  with 
chromic  acid  will  possess  the  formula  (1),  and 
this  is  converted  by  the  following  stages  into 
trimethylbrazilone  (3) : — 


CH 


/%H 


(1) 


«*^f  AOCH. 

CH, V^OCH, 


(2) 


(3) 


/\ocif, 

\^OCH, 


This  constitution  accounts  in  a  simple 
manner  for  the  formation  of  the  anhydrotri- 
methylbrazilone (1),  and  the  nitrohydroxydi- 
hydrotiimethylbrazilone  (2),  of  Perkin,  which 
can  be  represented  as  follows  : — 


(1) 


0, 


CH,o/\/  \:;h 


\c/ 


hoc- 


c 


\ 


0> 


Oocn, 
OCH, 


CH,(>/\/   \^^ 


(2) 


,COH 


EO^      ..;/\ 


0,N 


HOCH ^k^ 


OCH, 
lOCH, 


662 


BRAZILWOOD. 


When  anhydrotrimethylbrazilone  is  digested 
with  hydriodic  acid,  anhydrobrazilone  CicHioOt 
+£[,0  is  produced,  but  when  trimethylbrazi- 
lone  itself  is  treated  in  a  similar  manner,  the 
result  is  of  a  peculiar  nature.  The  compound 
GxfHeO(OH)4  so  obtained  does  not  consist  of 
brazilone,  but  possesses  the  formula  (1)  or  (2), 
and  on  distillation  with  zinc-dust  gives  brazan 
(3)  (Kostanecki  and  Lloyd,  Ber.  1903,  36, 
2193). 


0^ 


1. 


2. 


OH 

H0A/"YY>H 
's^ L    A    JOH 


a. 


11      III 
\y — 


Li  1899  Liebermann  (Ber.  32,  924)  obtained 
anhydro-a-naphthoquinone  resoroin  by  the  con- 
densation  of  2-3-dichlor-a-naphthoquLnone  with 
resorcin 


O 


O 

II 


uo— 


o 

and  this,  according  te  v.  Kostanecki  and  Lampe 
(Ber.  1908, 41, 2373),  is  3-hydroxybrazanquinone. 
By  reduction  with  hydriodic  acid*  this  gives 
hydroxy  brazan 


HorYYY^ 


and  from  this  latter  or  from  the  quinone  itself, 
brazan,  identical  with  that  obtained  from 
trimethylbrazilone,  is  produced  by  distillation 
with  zinc-dust.  Brazan  crystallises  in  leaflets, 
and  melts  at  202®. 

V.  Kostanecki  and  Lampe  (Ber.  1902,  35, 
1674)  considered  it  probable  that,  alter  all, 
trimethylbrazilin  does  contain,  as  found  by 
Perkin,  a  nucleus  which  on  oxidation  yields 
hemipinio  acid,  and  appear  to  have  adopted  the 
following  as  their  final  formula  for  brazilin : — 


HO- 


/V^\ 


I 


CH 


I 
HO'CH- 


OH 
OH 


V 

This  constitution,  it  is  evident,  will  still 
harmonise  with  the  formulas  of  trimethyl- 
brazilone and  azihydrotrim«thylbFazilone  given 
above  by  these  auuiors. 

HeiQff  and  Pollak  (Ber.  1906,  39,  267) 
suggestea  the  following  constitution  for  brazilin, 
trimethylbrazilone,  and  anhydrotrimethylbrazi- 
lone ; — 


ho^^^^^Njh, 

I    .OH 


k^ 


/\0H 

"vNch/  oh 

\3H/\/ 
Bouilin. 


CII.O 


\Ach/ 

TrimetbylbraiiloDe. 
CH.O/'^'^N^H 


I 
C 


"\»"\/ 


och, 
och. 


AnhydrotrimeUiylbraiilone. 

Herzig,  moreover,  observed  (Ber.  1904,  37, 
031)  that  trimethylbrazilone  undeigoes  isomeric 
change  when  it  is  dissolved  in  sulphuric  acid,  and 
yields  ytrimethylbrazUone  G,.H90,(OOH^„m.pL 
170*»-173%  to  which  the  formula 

^^HOOCK/^^* 
was  assigned  (Herzig  and  Pollak,  Monatah. 
1906,  27,  743).  Perkin  and  Bobinaon  (2.c) 
find  that  on  oxidation  with  permangaoate  this 
compound  gives  large  quantities  of  2-car&oaEy- 
^-6-iimAihoxyfhtnylacetic  acid  (GHgO)a*C«H|- 
(C00H)CH,-C00H,  and  that  theie  can  be 
little  doubt  that  its  true  constitution  ia  r^ne- 
sented  by  one  of  the  following  f ormuls : — 

ch,oj^Y^\h   cooh-ch.^och. 


\h    cooh/\)ch, 
£ chA^^' 

Finally,  in  1906  Herzig  and  Pollak  (Monatoh. 
27,  743)  considered  it  necessary  to  modify  their 
first  formula  for  braziUn,  and  have  azrived  at 
the  conclusion  that  that  finallv  proposed  by  v. 
Kostanecki  and  Lampe  correctly  represents  this 
colouring  principle.  The  more  recent  work  of 
Perkin  and  Robinson  detailed  above  shows,  how- 
ever, that  such  a  constitution  cannot  be  correct, 
because  it  does  not  account  for  the  producticm 
of  brazilinic  acid  by  the  oxidation  of  Uimethyl- 
brazilin 

0-CH,<X)OH 


CH.or^ 
l^'-co 


COOH 


BRAZILWOOD. 


663 


and  there  is  •yerv  reason  to  oonflider  that  the 
formula  suggeetea  by  the  latter  authors  is  the 
collect  representation  of  the  constitution  (c/. 
also  Perkm  and  Robinson,  Chem.  Soc.  Trans. 
1009,  95,  381)  of  braulin. 

BraziUin  yields  a  triaoetyl  derivative 
C„H,0,(C,H,0)„  yellow  leaflets,  m.p.  203*-207** 
(Schall  and  Dralle,  Ber.  23, 1434),  and  a  trimethyl 
ether  Ci,H|(0CH.),0t,  which  crystallises  in  two 
modifications,  melting  at  160*  and  178*  respec- 
tively (Engels  and  Perkin,  Chem.  Soc.  Proc.  1906, 
22,  132).  Brazilein  trimethyl  ether  combines 
with  formic  acid,  yielding  a  formic  acid  derivative 
which  crystidlises  in  gamet-ooloured  prisms,  and 
is  decomposed  into  its  components  by  treatment 
with  alcohoL 

The  constitution  assigned  to  brazilein  by 
Perkin  is  as  follows : — 


H0/\/°\cH. 

C(OH) 


<r 


These  authors  assign  an  orthoquinonoid 
structure  to  this  and  similar  ozonium  salts. 

More  recently  Crabtree,  Robinson,  and 
Turner  (Chem.  Soc.  Trans.  1918,  113,  859), 
emploving  butein  trimethyl  ether,  have  sue- 
ceoded  by  very  simple  methods  in  -  synthesising 
isobrazilein  hydrocmoride.  By  reducing  butein 
trimethyl  ether  (1) : — 


OH 

When  brazilein  is  dissolved  in  sulphuric  acid, 
and  the  solution  is  diluted  with  acetic  acid, 
minute  orange-red  prisms  of  isobrazilein  sulphcUe 
CifHiiOf'SO^H  separate  (Hummel  and  A.  G. 
Perkin,  CJiem.  Soc.  Trans.  1882, 41, 367),  and  this, 
on  treatment  with  alcohol,  gives  the  basic  sulphate 
Ci|Hi,0.(C^sH„0.S04H),,  which  crystallises  in 
red  neeoles.  Hydrochlorio  and  hydrobromic 
acids  at  100*  give  tMbrazileinchlorhydrin 
Ci|H||04'Cl,  and  isobrazikinbromhydrin 
CifHiiO^Br,  and  both  compounds  consist  of 
orange-colour^  prisms,  which  are  somewhat 
readfly  soluble  in  water,  forming  a  solution 
which  contains  free  haloid  acid.  These  interest- 
ing substances  dye  mordanted  fabrics  colours 
which  are  entirely  difFerent  from  those  yielded  bv 
brazilein,  and  the  shades  which  are  produced, 
especially  on  calico,  somewhat  resemole  those 
given  by  alizarin.  From  these  haloid  salts  by 
digestion  with  silver  oxide  a  substance  is  pro- 
duced known  as  isobrazilein,  which  has  the 
formula  CigH^aOs,  but  is  totally  distinct  from 
brazilein. 

According  to  Engels,  Perkin,  and  Robinson 
(Chem.  Soc.  Trans.  1908,  93,  1140),  whose 
paper  must  be  consulted  for  the  detailed 
account  of  brazilein  and  its  derivatives,  these 
Mobrazilein  salts  are  derived  from  4-3-tfu2eno- 
bemovyranol  (I),  and  the  sulphate  which  is 
t  rihffaroxy-4  -  S-iiidefiobenzopyranolanhydrohydro  - 
gen  stUpfHUe  (2),  may  be  represented  Uius : 

HSOt 


A^^CH  OHf^V^'N^H 


(1) 


CH 

II 
C 


CrOB.   CH, 


(2) 


c 


C        CH, 
OH        OH 


It  was  found,  for  instance,  that  when  brazilein 
trimethyl  ether  (3)  is  treated  with  sulphuric  acid, 
it  is  converted  with  loss  of  methyl  alcohol  into 
the  dimethyl  ether  of  isobrazilein  sulphate  (4) 

HSO4 

CH.O^^^^   \;H,       CHjOf^N^N^H 

II 
OOCH, 

(3)  0         CH, 


(*) 


C         CH, 

I  I 


<zz> 

OCH,    O 


> 


.r-'<y 


OH 


OCH, 
\)0— CH=CH— /~\OCH, 

the  dihydro  (benzylacetophenone)  compound 
(2)  is  obtained.  This  by  digestion  with  an 
excess  of  absolute  formic  acid  in  presence  of 
zinc  chloride  is  transformed  mto  the  hydro- 
chloride of  isobrazilein  trimethyl  ether  (3) : — 

HOCH 


.OH    O 


(2) 


cu,o/\/ 

^\C0^      *\)H, 


(3) 


ICH,  OCH, 

With  fuming  hydrochloric  acid  at  120''-160' 
demethylation  occurs  and  isobrazilein  hydro* 
chloride  is  produced  : — 

CI 

I 


H0/\^  \:H 


664 


BRAZILWOOD. 


By  the  subttitution  of  acetio  aoid  for  formic 
acid  in  this  reaction  the  corresponding  methyl 
iflobnuBilein  derivative  can  be  obtained  : — 


The  sjmthesiB  in  this  manner  of  a  colouring 
matter  so  closely  allied  to  brazilin  itself  by  the 
employment  of  butein«  a  yellow  dye  which 
exists  in  the  flowers  of  the  Buiea  frondoaa 
(Perkin,  Chem.  Soc.  Trans.  1904,  86,  1459),  is 
of  ezpectional  interest. 

Tne  oommercidl  prepartUiona  of  Brazilwood 
known  as  Brazilwood  extract  and  Brazilwood 
liquor,  are  prepared  by  boiling  the  ground  frosh 
wood  with  water,  and  evaporating  the  decoction 
thus  obtained  to  various  degrees  of  consistency 
without  acoeas  of  air,  or  as  rapidly  and  at  as  low 
a  temperature  as  possible,  t,g,  in  vacuum  pans. 

Dyting  Propertied, — Before  dyeing,  the  logs 
as  imported  are  rasped  to  a  coarse  powder,  and 
this  is  then  UFually  moistened  with  water  and 
allowed  to  ferment  for  some  weekB.  This 
operation  is  performed  in  order  to  increase  the 
colouring  power  of  the  wood,  and  there  can  be 
little  doubt  that  a  considerable  quantity  of  the 
bradlin  present  is  thereby  oxidised  to  the 
colouring  matter  brazilein.  It  has  been  con- 
sidered by  some  that  the  fresh  wood  contains  in 
reality  a  gluooside  of  brazilin,  which,  under  the 
influence  of  fermentation,  is  hydrolysed,  but  no 
evidence  has  been  forthcoming  in  support  of 
this  suffgestion. 

Although  still  used  in  calico-printing  and  in 
wool-dyeing,  Brazilwood  and  its  allies  have 
lost  their  importance,  chiefly  because  of  the 
fugitive  character  of  the  colours  thoy  yield.  In 
cafico-jprinting,  sappan  liquor  is  employed  for 
producing  steam-i^as  and  pinks,  the  mordant 
used  being  aluminium  acetate  or  stannic  oxalate, 
separately  or  combined,  together  with  some  oxi- 
dising agent,  e.g,  potassium  chlorate  or  a  copper 
salt.  It  also  enterfi  into  the  composition 
of  steam-chocolates  and  certain  steam  colours 
in  conjunction  with  other  dyewood  extracts. 
These  woods  have  also  been  much  used  in 
the  past  along  with  garanoine  in  dyeing  the 
reds,  chocolates,  and  other  colours  of  cheap 
prints. 

In  wool-dyeing  these  woods  have  been  ap- 
plied for  the  purpose  of  dyeing  reds  and  various 
shades  of  claret  and  brown,  the  wool  being  pre- 
viously mordanted  with  alum  and  cream  of  tar- 
tar or  oxalic  acid,  or  with  potassium  dichromatCL 
In  which  case  other  dyewoods,  e.g,  logwood 
and  old  fustic,  are  applied  in  addition.  The 
colours  produced  by  uiis  method  are  now  only 
used  to  a  limited  extent. 

In  cotton-dyeing,  peachwood-red  was  for- 
merly obtained  bv  fint  preparing  the  cotton  with 
tannm  matter,  toen  mordanting  with  a  stannio 
salt,  and  finally  dyeing  with  peach  wood,  sappan- 
wood,  &a  Browns  were  obtained  by  the  use  of 
logwood  in  addition,  with  or  without  a  final 


passage  through  a  feme  salt  solution  (nitrate  of 
von).  These  colours  are  now  replaced  by  othos 
obtained  from  coal  tar.  A,  G.  P. 

BRAZILEIN  and  BRAZILIN  v.  Bsazilwood. 

BRAZILIAN  ANIHE  o.  Oleo-bbois. 

BREAD  may  be  defined  as  the  doush  made 
by  the  mixture  of  the  flour  of  grain  wiUi  water, 
charged  in  some  way  with  sas  so  as  to  distend  it, 
and  afterwards  baked.  The  resulting  loaf  has 
a  delicate  spongy  structure  which  causes  it  to 
be  the  most  readily  and  eaaily  digested  of  all 
wheat  foods.  The  simplest  and  most  primitive 
form  of  bread  making  consisted  merely  in  mixing 
flour  with  water  ana  baking  the  donirk,  and  it 
survives  still  in  the  Passover  cakes  of  the  Jews 
and  in  the  '  damper '  of  the  Australian  settler. 
The  chaiging  with  carbonic  ffas  is  commonly 
effected  by  fermentation  with  leaven  or  yeast ; 
alternative  methods  involve  the  use  of  baking 
powders  (q.v,)  or  the  direct  injection  of  the  gas. 
In  addition  to  producing  gas,  fermentation  has  a 
profound  effect  on  the  constituents  d  flour,  and 
improves  the  flavour  and  digestibility  of  the* 
loaf. 

The  mechanical  result  of  aSratiqn  is  the 
creation  of  innumerable  vesicles  or  ceus  within 
the  dough,  which  are  subsequently  distended  by 
heat,  the  whole  mass  Icing  encased  in  the  baking 
within  the  crust  of  dextrin  formed  by  the  action 
of  heat  upon  the  starch.  The  making  of  bread 
from  wheaten  flour  a  only  possible  becaoae  the 
latter  contains  gluten.  Gluten  is  a  mixture  of 
proteins  which  becomes  viscid  when  mixed  with 
water,  and,  when  blown  up  with  gas,  has  suffi- 
oient  coherence  to  remain  in  the  form  of  a  honey- 
comb insteajd  of  collapsing  and  allowing  the  gas 
to  escape. 

Leavening  (LaU  levo^  to  rise)  has  been 
practised  from  time  immemorial  in  the  East; 
from  the  Egvptians  it  passed  to  the  Greeks  and 
thence  to  Tdb  Romans,  whose  conquests  and 
colonies  extended  the  art.  It  copsisted  in  the 
first  instance  probably  in  a  natural  fermentation 
of  the  dough  by  leaving  it  to  become  soar ;  but 
to  hssten  the  process  it  became  usual  to  add  to 
new  dough  a  portion  of  old  fermented  paste  or 
*  leaven.'  More  recently,  yeasts  were  substi- 
tuted for  the  piece  of  leaven.  These  weve  of 
various  oriffin,  that  from  the  distillery  being  the 
most  suitable.  To-day,  *  pressed '  or  Gorman 
yeast,  which  consists  of  yeast  grown  in  a  special 
way,  purified  by  repeated  washing  and  oom- 
preesed  into  cakes,  is  the  most  ^nerally  ased« 
This  keeps  well,  is  uniform  in  quahty ,  and  enables 
the  baker  to  exercise  a  close  control  over  the 
regularity  of  the  process. 

Bough  oonsisto  roughly  by  weight  of  two- 
thirds  mna  and  one-third  water,  the  quality  of 
the  water  being  a  matter  of  some  importainoe. 
The  softer  the  water  the  quicker  is  the  fermenta- 
tion, and  since  the  quality  of  the  bread  depends 
on  Cermentation  being  allowed  to  prooeed  to 
exactly  the  rieht  poinC  it  oannot  be  carried  out 
under  precise^  the  same  conditions  with  hard 
as  with  soft  water. 

ChenUsbry  of  bread  making. — ^The  chief  oon- 
stituents  of  flour,  so  far  as  bread  making  is  con- 
cerned, are  (1)  the  carbohydrates^  (2)  the 
proteins.  The  former  include  sugars  and  starch, 
the  proteins  consist  of  a  small  proportion  ol 
soluble  protein  and  a  large  proportion  of  in* 
soluble  gluten. 


BREAD. 


066 


The  gaa  formed  during  panary  fermentation 
is  produoed  by  the  action  of  the  yeast  organism 
on  dextrose.  Floor  contains  aoont  1  p.a  of 
sucrose  and  a  little  rafiinose  :  before  fermenta- 
tion, both  these  sugars  are  converted  into 
dextooee  b^  the  enzyme  inverUue  present  in 
yeast.  This  amount  of  sugar  would  not  suffice 
to  give  the  necessary  amount  of  gas,  but  it  is 
supplemented  by  the  maltose  produced  from  the 
starch  of  the  flour,  maltose  being  itself  converted 
into  fermentable  dextrose  by  another  enzyme 
malUue  contained  in  yeask 

The  formation  of  maltose  is  effected  by  tlio 
a^«ncv  of  a  diastatic  enzyme  present  in  flour ; 
itoegins  ilirectly  the  flour  is  wetted  and  continues 
throughout  fermentation  until  the  loaf  is  baked. 
Yeast  contains  no  diastatic  enzyme,  but  it  is 
possible  that  its  action  on  the  proteins  of  flour 
taoilitatos  the  production  of  diastase. 

Gas  escapes  from  the  doueh  throughout  the 
process  of  making  a  loaf,  and  the  supply  available 
must  be  sufficient  to  distend  the  loaf  and  main- 
tain it  f ull  V  distended  until  it  is  fixed  in  the  oven. 
Flours  which  have  relatively  little  diastatic 
enzyme  will  produce  insufficient  gas,  and  this 
fact  explains  perhaps  the  beneficial  results 
sometimes  obtained  on  adding  malt  extract* 
which  is  rich  in  diastase,  to  dough.  This  ques- 
tion is  in  reality  somewhat  more  complicated  in 
that  diastase  consists  of  two  enzymes — a  liquefy* 
ing  enzyme  which  renders  the  staroh  soluble,  and 
a  liydrolysin^  enzyme  which  converts  it  into 
maltose.  It  is  the  former  rather  than  the  latter 
enzyme  which  is  sometimes  lacking  in  flour. 

■Gluten  is  the  characteristic  and  the  most 
important  constituent  of  flour  (v.  Gluxsn).  It 
is  the  agent  which  principally  determines  how 
much  water  a  dough  will  take ;  what  length  of 
time  it  requires  to  be  fermented ;  what  will  be 
the  size  of  the  loaves,  and  their  colour,  flavour, 
and  general  appearance.  The  baker  requires 
quality  rather  than  quantity :  the  relation 
between  chemical  constitution  and  quality  is 
not  yet  TuUy  understood  {see  British  Association 
Report  on  Wheat,  Winnipeg,  1900).  During 
fermentation,  gluten  becomes  softer  and  at  first 
more  elastic,  siiosequently  it  softens  still  further, 
loses  elasticity,  and  begins  to  break  down. 
Baker's  yeast  always  contains  lactic  acid 
organisms,  and  the  conditions  in  a  long  sponge 
are  favourable  for  the  formation  of  this  acid, 
which  has  a  marked  solvent  and  disintegrating 
action  on  eluten.  Accordingly,  in  a  long 
sponae,  the  ^uten  is  considerably  disintegrated. 
The  Daker*s  art  consists  in  taking  the  sponge 
when  sufficiently  mellow.  If  under-fermented, 
a  foxy  crust  16  obtained ;  if  over-ripe,  the  eluten 
becomes  too  much  disintegrated  and  the  loaf  is 
less  bulky,  inclined  to  crumble,  and  in  extreme 
oases  becomes  sour. 

Common  salt  is  rery  generally  added  to 
bread.  This  is  done  firstly  to  give  the  necessary 
flavour,  as  owing  largely  to  the  action  of  salt  in 
stimulating  the  palate,  minute  quantities  of 
other  substances  can  be  recognised  in  its  pre- 
sence. Secondly,  salt  has  a  toushening  and 
binding  effect  cm  gluten,  though  it  has  a  solvent 
effect  on  some  of  the  proteins  of  flour.  In  view 
of  the  modem  theory  that  the  properties  of 
gluten  are  due  to  small  quantities  of  associated 
salts,  the  effect  of  the  added  sodium  chloride 
must  be  taken  also  into  account.    Salt  also 


checks  diastatic  action  and  fermentation  to 
some  extent.  Dse  is  made  of  this  property  by 
the  baker  in  dealing  with  sponges  which  are 
over-ripe  :  a  little  more  salt  than  usual  is  used 
in  making  the  douffh,  and  the  subsequent  fer- 
mentation is  retaraed  and  the  disintegrated 
gluten  somewhat  toughened. 

To  make  a  large,  well-aSrated,  shapely  loaf 
of  good  colour  and  flavour,  it  is  necessary  to  use 
a  large  proportion  of  flour  from  strong  wheats. 
Such  a  flour  usuaUy  contains  more  nitrogenous 
compounds  than  a  weak  flour.  Commercially, 
a  demand  has  arisen  for  strong  flours,  which 
accordingly  realise  a  higher  price  than  weak 
flours.  The  strongest  flours  come  from  parts  of 
the  United  States  and  Western  Canada,  also 
from  Hungary.  English  wheats  give,  as  a  rule, 
weak  flours,  which  by  themselves  are  unsuited 
for  modem  bread  making. 

It  is  the  object  of  the  &rge  millers  to  produce 
a  brand  of  flour  suited  for  bread  making  which  is 
a  blend  of  several  wheats,  and  to  maintain  this 
brand  of  flour  of  uniform  quality  throughout  the 
year.  The  preparation  of  sample  loaves,  made 
under  carefully  standardised  scientific  conditions, 
still  remains  the  most  satisfactory  test  of  quality, 
and  many  flour  mills  maintain  a  laboratory  for 
this  purpose. 

According  to  Humphries,  the  starch  of  flours 
made  from  wheat  grown  in  hot,  dry  climates  is 
very  stable  and  resists  disintegration.  Such 
flours  require  special  treatment,  tne  addition  of 
malt  extract  being  a  very  common  process. 
This  addition  generally  causes  an  improvement 
in  flavour,  due,  it  is  supposed,  to  the  production 
of  dextrinous  products,  which  further  have  the 
effect  of  making  the  bread  more  moist. 

There  is  a  loss  of  weight  during  panary 
fermentation,  due  to  the  conversion  of  carbo- 
hydrates into  alcohol  and  carbon  dioxide.  Jago 
estimates  this  loss  at  1*3  p.c. ;  other  authorities 
give  somewhat  higher  values.  Experiments 
made  at  Pittsburg  indicate  that  over  two- thirds 
of  the  total  fat  present  in  flour  is  lost  during 
baking. 

The  manufaetiue  of  bread.  To-day,  in 
large  towns,  bread  is  usually  made  in  bakeries  on 
a  manufacturing  scale,  and  machinery  is  em- 
ployed for  the  mixing  of  the  dough,  wei^hinjg 
and  moulding  of  the  loaves,  whilst  Uie  baking  is 
carried  out  in  large  draw-plate  ovens. 

There  are  various  systems  of  bread  making 
depending  on  whether  the  dough  is  made  right 
off  in  one  operation,  or  whether  a  portion  of  the 
flour,  the  yeast  and  the  water,  are  first  made  up 
into  a  loose  paste — ^the  sponge — ^and  the  rest  of 
the  fiour  aaded  some  nours  later.  A  thiid 
system  involves  the  preparation  of  a  ferment 
most  commonly  consisting  of  potatoes,  boiled 
and  mashed  with  water  to  which  a  little  raw 
flour  is  added.  The  yeast  is  introduced  into 
this  and  fermentation  carried  out  so  as  to  favour 
growth  and  reproduction  and  get  the  yeast  in  a 
particularly  active  state.  Flour  is  added  to 
make  a  sponge,  and  this,  some  hours  later,  made 
into  dough.  The  longest  system  of  fermenta- 
tion is  that  practised  in  Scotland.  An  eighth  or 
tenth  of  the  flour  is  made  into  a  fairly  tight 
dough  with  a  little  yeast  and  allowed  to  He  14  to 
18  £>ur8,  during  wmch  time  the  eluten  becomes 
almost  entirely  soluble,  and  the  dough  acquires 
a  distinctly  vinous  smell  and  taste.    It  is  then 


666 


BREAD. 


broken  ap  with  flour  and  the  remainder  of  the 
liquor  to  a  thin  sponge,  whioh  lies  about  1}  hours 
tiH  it  shows  signs  of  turning  and  is  then  made  up 
into  a  rather  soft  dough.  The  long  systems 
formerly  in  use,  were  partly  the  result  of  custom 
and  partly  due  to  the  slow  working  yeasts  used. 
To-day,  partioularly  in  large  bakeries,  the 
tendency  is  in  the  direction  of  the  straight 
dough,  though  the  sponee-and-dough  method  is 
very  largely  practised.  It  has  been  claimed  that 
the  lonser  processes  require  less  veast,  make 
bulkier  oread,  and  bread  of  better  flavour. 

When  the  dough  is  ready  it  is  scaled  off  and 
kneaded  into  shape.  This  presses  out  nearly  all 
the  gas  and  toughens  the  f^luten;  if  it  is  not 
thoroughly  done  the  loaf  is  likely  to  contain 
holes.  The  loaves  are  next  put  aside  in  a  warm 
place  to  prove,  during  which  the  gluten  relaxes 
and  the  yeast  expands  the  dough  evenly.  Too 
much  proof  must  be  avoided,  as  on  putting  the 
bread  in  the  oven  the  excessive  expansion  is 
frequently  followed  by  the  coUapse  and  flatten- 
ing of  the  loaves.  The  loaves  are  then  baked  at 
^B(f'-600''F.,  a  2-lb.  loal  requiring  about  4(MM) 
minutes.  During  baking,  the  gases  are  at  first 
expanded  and  the  dough  swdla,  the  yeast  is 
killed,  some  of  the  starch  cells  burst,  the  heat 
sets  the  gluten  and  the  starch,  and  finally  the 
crust  is  converted  into  dextrin  and  in  part 
caramelised. 

It  is  the  baker's  object  to  get  the  maximum 
number  of  loaves  from  a  sack  of  flour.  Accord- 
ingly, that  flour  is  selected  which  has  the 
greatest  power 'to  take  up  and  retain  moisture. 
Such  flours  are  often  termed  strong.  A  sack 
(280  lbs.)  of  good  flour  yields  about  96 
quartern  loaves. 

Vienna  bread  is  a  term  applied  to  rolls 
and  light  fancy  bread  baked  in  an  atmosphere 
entirely  charged  with  steam,  to  obtain  wmch  a 
special  oven  construction  is  adopted.  The 
starch  of  the  flour  is  burst  b^  heat  and  chai]{g|ed 
into  dextrin  by  the  aid  of  moisture,  so  that  a  nch 
golden-brown  highly  glazed  crust  is  obtained. 

Leavened  6rea(i.— In  France  and  elsewhere 
on  the  Continent,  bread  is  made  from  leaven,  but 
in  the  more  important  towns  this  mode  of  bread 
making  has  been  given  up  for  the  Viennese  and 
English  processes.  The  practice  in  the  prepara- 
tion of  tne  leaven  consisted  in  a  series  of  stages 
(*levain  de  chef,  levain  de  premiere,  levain  de 
seconde,  levain  de  tout  point^*  by  which,  starting 
with  a  piece  of  dough  put  away  from  a  previous 
baking  and  adding  at  intervaJs  more  and  more 
flour  and  water,  the  required  quantity  is  leavened. 
From  this  is  taken  a  hau,  which  when  baked  yields 
a  dark,  sour  bread ;  the  remainder,  being  again 
mixed  with  a  quantity  of  flour  and  some  yeast, 
produces  a  whiter  and  less  sour  dough,  a  portion 
of  which  is  baked  and  the  residue  once  more 
added  to  fresh  flour.  This  subdivision  is  re- 
peated three  times,  the  bread  improving  at  each 
stage.  A  characteristic  example  ofleavened 
bread  is  seen  in  the  rye  bread  (Sohwarzbrod)  of 
Germany. 

Next  to  wheat,  rye  is  the  chief  bread-making 
^ain  throughout  the  world,  and  in  particular  it 
is  largely  uSod  in  Northern  Europe.  Rye  bread 
is  moister,  closer,  and  darker  m  colour  than 
ordinary  household  bread.  There  are  several 
qualities,  differing  in  the  proportion  of  bran 
oontained,  the  so-called  <  pumpernickel '  being  an 


extreme  example.  Fine  rye  bread  is  as  digee- 
tiUe  as  wheaten  bread,  but  in  the  case  of 
pumpernickel  a  very  large  proportion  is  un- 
absorbed  (Romberg,  Arcmv.  i.  Hygiene,  1897, 
28,  244). 

Baking  Powders, — Oarbon  dioxide  may  also 
be  generated  within  dough  by  the  action  of 
bakmg  powders,  which  are  usually  mixtures  of 
sodium  carbonate  and  some  acid  or  acid  salt, 
and  evolve  gas  when  moistened  or  heated. 
Owing  possibly  to  the  difficulties  of  distributing 
fresh  yeast,  baking  powders  were  formerly 
widely  employed  in  America.  They  are  not 
used  much  in  this  country  for  wmte  bread. 
They  are  usually  classified  according  to  the  acid 
constituent,  as  tartrate,  phosphate^  or  alum 
powders  (r.  BAsnro  powdxbs).  The  so-called 
self-raising  flour  contains  baking  powder  already 
mixed  wiw  it. 

AiraUd  bread  is  made  by  injecting  carbon 
dioxide  into  dough  by  mechuucal  means.  The 
process  was  originated  by  Dr.  Dauslish  in  1859, 
apd  at  one  time  enjoyed  considerate  popularity, 
but  it  has  not  met  with  universal  favour  on 
account  of  the  raw  and  insipid  taste  of  the  bread, 
due  to  the  absuice  of  the  products  idiioh  yeast 

Sroduces  during  fermentation.  The  carbon 
ioxide  is  produced  separately  and  forced  into 
water  under  pressure :  this  water  is  mixed  with 
the  flour  in  a  specially  constructed  vessel,  in 
which  the  pressure  is  maintained.  On  opening 
the  vessel,  the  dough  rises  and  can  be  imme- 
diately baked.  The  advantages  claimed  for  the 
system  are  uniformity  of  result,  and  the  avoidance 
of  the  losses  in  weight  which  occur  during  fer- 
mentation. A  later  development  consisted  in 
mi^g  a  little  wort,  made  m>m  malt  and  flour 
and  fermented  till  sour,  with  the  water  to  be 
agrated,  so  as  to  improve  the  flavour.  The 
process  is  eminently  suited  for  the  manufacture 
of  whole-meal  bread,  as  the  preparation  of  a 
batch  of  douffh  can  be  effected  in  tlurty  minutee. 
Compositum  of  Bread, — ^The  general  composi- 
tion of  bread  is  very  variable.  About  two-thirds 
of  the  volume  is  made  up  of  gas.  By  weight  it 
contains  40-50  p.c.  of  water  and  6*5  p.a  of 
protein,  the  balance  being  mainly  carbohydrate. 
Hutchison  sives  the  following  mean  figures  for  a 
number  of  breads  analysed  by  him : — 

Carbo- 
Water  Protein  Fat  hydiatai  GeUulose  Ath 
White    .       .  40      6*5      10      61-2      0-3       1-0 
Wholemeal.  46     6-3      1*2     44*8      1-5      1-2 

On  keeping,  a  loaf  gradually  loses  mouture  to 
the  extent  of  8  p.c.  in  48  hours,  14  p.a  in  72 
hours  (Goodfellow)  or  14  p.c.  in  1  week  (▼•  Bibca). 
At  the  same  time,  the  bread  becomes  stale,  but 
this  change  is  not  attributed  to  loss  of  moisture, 
as  much  of  the  freshness  is  restored  on  heating, 
during  which  considerably  more  water  is  lost. 
It  is  suggested  that  staleness  is  due  to  a  gradual 
combination  of  water  with  the  starch  or  gluten 
which  is  readily  broken  up  by  heat ;  or,  alter- 
natively, tiiat  it  is  due  to  the  shrinkage  of  the 
fibres  which  form  the  walls  of  its  visible  pores. 

KatE  (Zeitsoh.  physioL  Chem.  1915)  haa 
shown  that,  whereas  the  softening  of  the  bread 
crust  is  due  to  the  absorption  of  moistare,  the 
crumb  will  become  stale  even  when  no  kas  of 
moisture  takes  place. 

The  experiments  indicate  that  when  bread 
crumb  is  Lept  at  ordinary  temperatuiM  and 


BREAD. 


667 


loas  of  moisture  prevented,  the  starch  becomes 
harder  and  the  amount  of  water-soluble  poly- 
saccharides diminishes,  the  latter  being  suggested 
as  the  cause  of  the  sweeter  taste  of  new  bread 
as  compared  with  stale. 

The  gluten  appears  to  absorb  moisture  from 
the  starch  sraniues  as  staling  proceeds,  the 
latter  shrinking,  with  the  result  that  the 
granules  are  retMily  separable  from  the  gluten, 
thus  causing  the  bread  to  become  crumbly. 

The  shrmkage  of  the  granules  can  m  seen 
with  the  microscope,  narrow  air  spaces  being 
observed  between  the  granules  and  the  gluten. 

The  adulteration  of  bread  with  alum,  zinc, 
and  copper  sulphates,  lime,  &o.,  is  now  entirely 
a  thing  of  the  past.  These  were  added  to 
prevent  the  injurious  effects  of  an  excess  of 
cUastase  on  the  starch  during  pananr  fermenta- 
tion when  inferior  flour  was  employed.  The 
cheapening  of  flour  and  the  critical  demands  of 
the  public  for  a  well-risen  white  loaf,  as  well  as 
improvements  in  the  miller's  technique,  have 
necessitated  the  use  of  the  best  flours  in  bread. 

The  question  of  colour,  meaning  brightness 
of  appearance  in  crumb  and  crust,  is  an  im- 
portant one ;  at  the  moment,  the  demand  is  for 
a  white  loaf.  Colour  is  lai^^ely  a  question  of 
optics  ;  a  weak  but  very  white  flour  may  make 
poor  diziffy-looking  loaves,  whilst  a  darker, 
stronger  flour  will  make  loaves  which  are  better 
aerated  and  hence  appear  much  whiter. 

A  modem*  development  is  the  artificial 
bleachinff  of  flour,  usually  with  nitrous  fumes 
produced  by  some  electrical  process.  There  is 
no  proof  that  bread  made  with  bleached  flour  is 
deleterious  to  health,  but  its  use  has  been  for- 
bidden in  America  under  the  Pure  Food  Laws. 
It  is  a  matter  of  controversy  whether  bleaching 
by  nitrogen  peroxide  is  due  to  oxidation  or  to 
nitration.  Bleaching  does  not  change  a  low- 
grade  flour  into  a  higher  one,  and  bleached  flour 
should  therefore  be  declared  as  such. 

The  souring  of  bread  is  one  of  the  baker's 
problems.  It  is  the  result  of  a  combination  of 
bacterial  fermentations,  the  bacteria  being 
introduced  by  the  yeast,  by  the  flour,  or,  as 
should  not  occur,  by  the  use  of  dirty  vessels. 
The  flavour  of  fermented  bread  improves 
gradually  as  the  process  proceeds  until  a  maxi- 
mum is  reached,  after  which,  if  fermentation  is 
continued,  it  begins  to  deteriorate.  At  this 
stage  the  alcohofic  ferment  is  exhausted  and 
the  acid  fermentation  begins  to  predominate. 
The  sourness  is  mainly  due  to  lactic  and  acetic 
acids,  the  odour  to  acetic  and  sometimes  butyric 
acids  (J.  Soc.  Chem.  Ind.  1916).  A  cause  of 
mustiness  in  bread  has  been  traced  to  the 
presence  of  Bhizopus  nigricans  and  AspergiUtis 
m  the  flour  from  which  the  bread  was  made. 

Extracts  made  from  such  flours  when  mixed 
with  good  flour  caused  mustiness  or  sourness 
in  the  resulting  bread. 

Such  bread-diseases  as  ropiness  (c/.  £.  J. 
Watkins,  Bopiness  in  Flour  and  Breaid,  J.  Soc. 
Chem.  Ind.  1906, 360)  are  due  to  specific  bacteria. 
According  to  Kayser  and  Delaval,  ropiness  is 
due  tobacteria  of  the  genus  Mesenterieus, 
originating  in  flour.  The  spores  form  rods 
3-6  ft  long  and  8*4-0*6  fi  thick,  sometimes 
united  in  pairs  and  very  resistant  to  chemical 
and  physical  reagents.  The  development  on 
breaa  is  very  rapia  with  abundant  spore  forma- 


tion. The  bread  becomes  yellowish-brown,  soft, 
and  viscous  and  acquires  an  objectionable 
smell.  The  addition  of  lactic  acid  to  the  dough 
with  from  30  to  45  minutes  baking,  depending 
on  the  weight  of  the  loaf,  prevents  the  germina- 
tion of  spores. 

In  a  modem  bakehouse,  bacterial  diseases 
should  not  occur ;  they  may  often  be  traced  to 
the  use  of  unsound  flour. 

WhoU-tneal  Breads. — ^The  majority  of  the 
patent  breads  belong  to  the  *  brown  variety, 
and  contain  more  of  the  wheat  grain  than  the 
white  flour.  In  some,  the  finely  ground  bran  is 
introduced,  in  others  the  germ,  whilst  a  third 
class  claim  to  contain  the  complete  wheat  grain. 
Bran  is  very  rich  in  diastatic  enzyme,  here 
termed  cerealin,  and  its  introduction  causes  a 
veiT  rapid  conversion  of  the  starch  into  dextrin 
and  suffar.  This  causes  the  dough  to  become 
soft  ana  clammy  and  to  bake  brown :  in  addition, 
it  becomes  very  prone  to  souiinff.  The  use  of 
sodium  bicarbonate  and  hydrochloric  acid  for 
aerating  whole-meal  bread  is  common.  When 
the  fermentetion  process  is  used,  the  bran  is  not 
introduced  until  the  dough  stace.  Whole-meal 
bread  has  a  sreat  tendency  to  oecome  sodden ; 
it  has  to  be  baked  for  a  considerable  time,  and 
consequently  often  has  a  thick  crust.  Germ 
has  a  very  injurious  effect  on  flour,  owinc;  to  its 
diastatic  character,  and  the  tendency  to  become 
rancid.  Every  effort  is  therefore  made  to 
remove  it  as  completely  as  possible.  When 
subjected  to  the  action  of  superheated  steam, 
the  germ  is  cooked,  the  diastatic  properties  are 
destroyed,  and  it  acquires  a  pleasant  malt-like, 
nutty  flavour  and  aroma.  This  process  was 
patented  by  B.  Smith  of  Macclesfield,  and  a 
mixture  of  one  part  of  treated  germ  and  three 
parts  of  white  flour  constitutes  Hovis  flour,  from 
which  Hovis  bread  is  made. 

The  relative  nutritive  values  of  white  and 
whole-meal  bread  is  a  highly  controversial 
subject.  It  is  claimed  that  whole- meal  bread  is 
richer  in  protein  and  so  more  valuable,  but  this 
is  far  from  being  generiilly  true.  A  second  con- 
tention is  the  lu'ger  amount  of  mineral  matter, 
especially  phosphoric  acid,  in  the  brown  bread. 
This  is  certainly  true,  but  experience  has  shown 
that  the  mineral  matter  is  not  all  absorbed  from 
white  bread,  whilst  in  whole-meal  bread  the 
quantity  absorbed  is  so  much  less  that  it  is 
probable  the  blood  obtains  mnoh  the  same 
amount  from  both  (Hutchison).  Whole-meal 
bread  is  defectively  absorbed,  owing  to  the 
cellulose  which  it  contains  preventing  the  gastric 
juices  from  gaining  access  to  the  neighbouring 
nutritive  in^edients,  and  for  the  same  reason 
it  interferes  somewhat  with  the  absorption  of 
other  foods.  When  tiie  unsatisfactory  nature 
of  the  whole-mead  bread  itself  and  the  pro- 
cautions  necessary  in  its  manufacture  are  taken 
into  consideration,  its  universal  use  in  times 
of  plenty  is  not  to  be  advocated.  With  bread 
containing  added  germ  the  case  is  different,  the 
bran  is  absent  and  the  food  value,  both  as 
regards  protein  and  phosphate,  is  larger  than 
of  white  Dread. 

The  use  of  flour  containing  the  untreated 
original  germ  of  the  wheat  beny  for  bread  is, 
none  the  less,  disadvantageous,  since  the  flour 
easily  becomes  rancid  and  the  germ  enzymes 
commence  to  act  on  the  gluten  from  the  moment 


668 


BREAD. 


the  floor  is  made,  causing  the  loaf  to  be  of  poor  I 
oolour  and  to  be  less  finely  vesiculated  and  j 
digestible.  These  factors  more  than  outweigh  \ 
the  advantages  of  the  very  small  additional 
amounts  of  protein,  oil,  and  phosphate  intro- 
duced and  the  slightly  sweeter  flavour  of  serm 
bread.  The  germ  contains  10-12  p.c.  of  oil, 
which,  it  IS  stated,  can  be  used  for  the  pro- 
duction of  margarine.  Under  war  conditions 
in  Germany  arrangements  were  made  to 
collect  the  eerm  from  the  nuUs  and  extract 
this  oil.  The  residue  of  the  germ  yields  a 
valuable  protein  food.  The  germ  also  contains 
such  vitamines  as  are  present  in  the  wheat- 
grain.  If  the  vitamines  which  are  considered 
as  essential  to  the  maintenance  of  health, 
are  to  be  obtained  from  none  of  the  other 
foods  eaten  in  the  dietary,  then  wholemeal 
brecui  will  have  obvious  aavantages  over  that 
made  from  white  flour.  However,  in  actual 
practice  this  is  not  the  case. 

The  desire  for  more  phosphates  can  be  met 
by  the  addition  of  phosphoric  acid  to  the  flour, 
as  is  indeed  being  done  at  the  present  moment 
during  the  milling  process  in  order  to  improve 
the  quality  of  flour  (c/.  Humphries,  £ng.  Pat. 
13136  and  17279  of  1908 ;  Chitty  and  Jago, 
Eng.  Pat.  22434  of  1909;  Levin,  Eng.  Pat. 
3673  of  1910). 

Under  the  stress  of  war  conditions  both 
milling  and  baking  practices  were  altered,  and 
every  effort  was  nuuie  to  render  the  maTJmnm 
possible  proportion  of  the  wheat  grain  available 
for  human  food.  Millers  were  only  allowed 
to  manufacture  straight  run  flour,  and  the 
percentage  to  be  extracted  from  wheats  of 
various  origin  was  laid  down  in  numerous 
orders  under  the  Defence  of  the  Realm  Act. 
This  amounted  to  81  p.c.  for  English  and  hard 
Manitoba  wheats,  ana  83  p.c.  for  Indian  and 
Australian  varieties.  In  addition,  not  more 
than  25  p.c.  and  not  less  than  10  p.c.  flour  from 
other  cereals  was  to  be  mixed  witn  the  wheaten 
flour.  Bread  was  to  be  at  least  12  hours  old 
before  it  was  sold. 

AtUhorities. — Jago,  Science  and  Art  of 
Breadmaking,  London,  1911 ;  Hutchinson,  Food 
and  the  Principles  of  Dietetics,  London,  1911 ; 
Wheat :  Brit.  Ass.  Report,  Winnipeg,  1909 ; 
Hamill,  Local  Govt.  Board,  No.  114,  1911. 

E.  F.  A. 

BREAD  FRUIT.  The  fruit  of  Artocarpus 
ineisa  (Linn.).  The  tree  grows  freely  in  tropical 
islands,  and  yields  fruit  continuously  for  9  months 
in  the  year.  The  fruit  is  nearly  spherical,  and 
sometimes  weighs  6  or  6  lbs.    It  is  usually 

gathered  while  yet  unripe,  t.e.  before  its  starch 
as  changed  into  sugar ;  sometimes  the  unripe 
fruit  IB  peeled,  wrapped  in  leaves  and  cooked 
whole,  when  a  product  resembling  ordinary 
bread  is  obtained ;  or  the  unripe  fruit  ia  dried, 
powdered,  and  sifted,  yielding  a  flour  which  has 
the  following  composition  : — 

Water  PrrUcin  Fat     Starch    Fibre    Afih 
14-3       10      0-2      83-8      0*2      04 

(Balland,  J.  Pharm.  Chim.  1903,  17,  [10]  476). 

The  leaves  and  wood  of  Artocarpus  ijicisa  are 
devoid  of  oolourinff  matter  (A.  G.  Perkin, 
Ghem.  Soc.  Trans.  1898,  73,  1019).  A  closely 
related  tree  {Artocarpus  integrifoUa)  bears  a  still 
larger  fruit,  '  jak  fruit,'  weighing  about  26  lbs., 


of  which  about  26  p.o.  ia  flesh*  the  remainder 
being  rind  66  p.c.,  and  seed  8  p.c.  The  flesh, 
when  ripe,  contains  about  6  p.c  of  sugar,  mainly 
cane  sugar  (Prinaen,  Geeriigs,  Ghem.  Zeit.*18979 
21,  f721  719).  H.  L 

BREAH  V.  Olbo-bbsins. 

BREEZES.  {Braise,  Ft.)  The  dust  of  coke 
or  charcoal.  The  coke  burner  applies  this  term 
to  the  smaU  residual  coke  obtained  in  coke 
burning.  The  sifted  ashes  removed  from  houses 
is  called  *  breese,'  and  sold  under  that  name  to 
briokmakers  and  others.  An  airangement  for 
burning  breeze  is  described  in  J.  Soc.  Chem.  Ind. 
5,  425. 

BRElDttr,  BREltN  v.  Olbo-besiks. 

BREMEN  BLUE  and  BREMEN  GREEN. 
Pigments  containing  a  bade  copper  carbonate 
with  alumina  and  calcium  carbonate. 

BREWING.  Beer  is  made  from  water, 
malt,  and  hops.  Raw,  prepared  grain,  or  sugar 
is  often  substituted  for  a  portion  of  the  malt, 
and  some  other  vegetable  bitters  occasionally 
for  a  portion  of  the  hops. 

Water  used  in  brewing  must  be  free  from 
sewage  pollution,  poisonous  metals,  or  sub- 
stances which  may  affect  the  flavour  of  the 
beer,  such  as  iron. 

The  composition  of  the  water  used  in  mashing 
has  an  important  effect  on  the  final  products 
Indeed,  it  may  be  considered  that  the  reputation 
of  the  best-known  brewing  districts  was  initially 
due  to  their  natural  water  supplies.  The 
following  table  ^ives  the  amounts  of  the  more 
important  constituents  of  some  of  these  waters. 
The  figures  represent  parts  per  100,000 : — 

Burton  Dublin  London  Munich  Pilsen 

CaO            .  20-40  14  2-10  10-20  4r-l0 

MgO           .  6-15  1  1-2  3-4  2-4 

SO,            .  40-80  1-4  1-20  2-4  2-14 

CO,            .  16  10  4-36  10  3-5 

CI      .         .  4  2  2-10  6  1-4 
Na,0  and 

K,0  6  1  4-20  —  2 

Nitrates     .  2-10  —  —  —  — 

The  Burton  waters,  by  means  of  which  are 
produced  the  finest  pale  and  strong  ales,  are 
characterised  by  calcmm  sulphate  with  smaller 
quantities  of  carbonate,  and  magnesium  sulphate 
and  carbonate.  Small  quantities  of  chlorides 
and  nitrates  are  usually  present,  even  in  watere 
which  are  free  from  sewage  pollution.  The 
amount  of  calcium  sulphate  vanes  considerably 
in  the  different  weUs,  owing  to  the  uneven 
distribution  of  the  gypsum  in  the  formations 
through  which  the  water  peroolates. 

The  Dublin  water  used  in  brewing  the  well- 
Imown  stout  has  its  chief  constituent,  calcium 
carbonate,  removed  by  boiling  before  use,  so 
that  as  used  in  the  mash  tun  it  ia  a  very  pure 
water. 

The  London  waters  are  used  for  beer  and 
stout  brewing,  but  although  the  beers  are  not 
much  known  outside  the  district,  London  pewter 
has  more  than  a  local  reputation.  They  are 
chiefly  characterised  by  calcium  and  sodium 
carbonate ;  sulphates  and  chlorides  are  also 
usually  present.  Some  show  a  high  amount  of 
sodium  chloride,  and  are,  no  doubt,  contaminated 
by  sea  water,  and  if  more  than  100  parts  NaCl 
per  100,000  are  present  are  unsuitable  fur 
brewing. 


Typic*!,  RpntRS  OP  tub  Poitr  Sricnta  o 
A,  Hordeum  vulgan 


Four  Poems  of  Babt.bt,  bpowiso  Sevebal  roHHoK  C'HARAtTBBS. 


Fio.  1. — Vabhties  of  Barlbt. 


670 


BREWING. 


The  Munich  waters  are  very  similar  to  the 
Dublin  waters,  and  the  dark  fuU-flayoured  lager 
is  their  product. 

The  Pilsen  waters  are  extremely  pure,  and 
in  the  small  amohnt  of  salts  the  carbonates  do 
not  dominate  the  sulphates,  as  in  the  Dublin, 
London,  and  Munich  waters.  The  lager  beer 
produced  is  a  pale  and  delicate  beer. 

Waters  containing  sodium  chloride  up  to 
60  parts  per  100,000  are  considered  suitable  for 
brewing  mild  ales. 

Where  the  natural  water  does  not  conform 
to  one  of  these  types,  it  is  usual  to  make  some 
attempt  at  imitating  it  by  the  addition  of  one 
or  more  salts.  Thus,  if  paJe  ale  is  to  be  brewed, 
calcium  sulphate  or  chloride  is  added ;  if  mild 
ale,  a  smaller  proportion  of  calcium  salts  and  a 
little  sodium  chloride.  For  brewing  stouts,  the 
water  is  softened  by  the  addition  of  suitable 
salts.  In  general,  calcium  and  magnesium 
carbonates  are  removed  by  boiling  or  by  heating 
under  pressure  with  agitation.  Such  treatment, 
although  resulting  in  a  better  beer,  is  said  not 
to  equal  that  obtained  by  the  untreated  natural 
waters. 

Much  has  been  written  in  order  to  explain 
the  effect  of  the  dissolved  salts.  Waters  con- 
taining calcium  sulphate  produce  pale,  delicate 
beers  which  clarify  well ;  calcium  chloride 
appears  to  have  similar  effects.  Calcium  salts 
remove  much  phosphoric  acid.  Malt  always 
contains  more  of  this  than  the  yeast  requires, 
and  it  is  possible  that  a  removal  of  a  portion 
may  be  beneficial,  although  it  is  conceivable 
that  under  some  conditions,  such  as  the  use  of 
a  large  proportion  of  some  malt  substitutes,  too 
much  might  be  removed.  Magnesium  salts  do 
not  give  such  satisfactory  results;  the  beers 
have  a  reddish  shade,  and  do  not  clarify  so  well. 
Sodium  chloride  produces  a  sweet  flavoured  beer. 
Calcium  and  magnesium  carbonates  give  dark, 
harsh  flavoured  beers,  which  do  not  clarify 
easily,  and  these  effects  are  accentuated  if 
sodium  carbonate  is  present. 

On  the  whole,  tne  evidence  indicates  that 
although  the  nature  of  the  dissolved  ssJts  has 
some  effect,  yet  the  chief  results  are  due  to  the 
change  which  the  salts  produce  on  the  hydrogen 
ion  concentration  when  the  malt  is  mashed  with 
the  water. 

The  effect  of  acidity  on  enzyme  action  is 
well  known,  and  the  bad  effects  of  alkaline 
waters  are  largely  due  to  their  restrictive  effect 
on  enzyme  action.  Schjeming  (C.  R.  de.  trav. 
du  Lab.  de  Carlsbeig,  1913,  312)  measured  the 
hydrogen  ion  concentration  of  worts  made  with 
waters  containing  various  salts.  He  found 
calcium  sulphate  and  chloride  and  magnesium 
sulphate  and  chloride,  when  about  1(K)  parts 
per  100,000  are  present,  all  raised  this  trom  F> 
6'1  to  5*7.  That  sodium  chloride  and  sodium 
sulphate  had  no  effect,  and  that  calcium  and 
magnesium  carbonates  lowered  it.  He  also 
found  that  P*  6*5  was  the  most  favourable  for 
enzyme  action  on  the  carbohydrates,  and  5 '3 
for  the  proteid  transformation,  and  that  dight 
changes  between  this  and  Oi,  the  normal  P^ 
of  malt  worts  prepared  with  distilled  water* 
have  a  marked  effect  on  these  actions.  Sherman 
and  Thomas  (J.  Amer.  Chem.  Soc.  1915,  625) 
find  a  P*  4'2  to  4*6  for  the  maximum  diastatic 
action.    The  effects  of  these  salts  on  enzyme 


action  have  been  confirmed  by  other  authorB. 
H.  T.  Brown  (J.  Inst.  Brewing,  1909.  216) 
and  Weiss  (0.  R.  du  Lab,  de  Carlsbeig,  1903, 
216)  found  that  calcium  salts  increMed  the 
amount  of  soluble  nitrogen  compounds,  and 
many  others  have  observ^  the  effect  on  starch 
tWormatioii. 

Malt  contains  primary  and  secondary  phos- 
phates, and  it  is  easy  to  construct  an  equation 
showing  how  calcium  salts  may  increase  the 
acidity,  thus : — 

4K,HP04-f3CaS04 

=2KH,P04+3K,S04+Ca,(P04), 

Other  equations  may  be  written,  showing  tiie 
formation  of  dicalcium  phosphate,  but  as  this 
is  also  insoluble,  the  result  will  not  be  affected. 
It  may  be  otherwise  with  magnesium  salts,  as 
dimagnesium  phosphate  is  soluble,  and  this 
may  explain  the  less  satisfactory  effect  of 
magnesium  salts.  On  the  other  hand,  Schjeming 
found  them  to  have  the  same  effect  on  the 
hydrogen  ion  concentration  as  calcium  salts. 

The  preference  of  brewers  for  hard  water 
for  brewing  beers  thus  seems  explicable ;  bnt 
the  equalfy  well-established  fact  that  soft 
water  must  be  used  for  stout  does  not  appear 
so  evident.  The  la^er  beer  brewers  also  find 
hard  waters  nnsmtable.  Some  Continental 
authorities  have  gone  the  length  of  stating  that 
the  most  suitable  brewing  water  for  all  purposes 
is  water  free  from  dissolved  salts,  bnt  uie  taith 
of  the  pale  ale  brewer  in  his  sulphated  water 
remains.  See  also  0.  Miskowsky,  Zeit.  f.  d.  sea. 
Brau.  1911,  49  and  97  ;  Windisoh  and  G<rfdacker 
(Jahresber  des.  Ver.  u.  Lehranstalt  f.  Brauerei, 
Berlin,  1916 ;  Read- 
man,  J.  Soc.  Chem. 
Ind.  1894, 367 ;  Lott, 
Trans.  L  Br.  1897, 344; 
Matthews,  Trans.  I. 
Br.  1893, 109,andl75). 

Malt  is  made  from 
barley,  occasionally 
from  wheat  or  oats. 
Barley  used  for  malt- 
ing is  mainly  of  four 
different  varieties: —  p 
Fig.  1. 

A.  Ifordetim    vtd- 
gore      (fiexasiiehuni), 
found    in    commerce  . 
as     Chilean    bariey, 
sometimes  Syrian. 

B.  HordeXim  inter- 
medium,    found    in  ^ 
commerce  as  North 
AJMcan  and  Smyrna 
barley.  Bere. 

C.  Hordeum  die- 
ttchon,  found  in  com- 
merce as  Goldthorpe, 
Chevalier,  &c. 

D.  Hordeum  defi- 
dena.  Bulletin  622, 
Bureau  of  Plant 
Industry,  Washing- 
ton, U.S.A. 

The   barley   com 
consists  of  three  chief  parts,  the  coverings  (tlie 
palese  (P),  the  endosperm  (£),  and  the  embryo 
(O)  (Kg.  2). 


Fio.  JL 


BREWING. 


671 


60-60] 

p.c 

9-10 

8-14 

2 

2-3 

15-30 

2i-3i 

The  coveringt  oontain  the  greater  portion 
of  the  celluloee  and  oellnlar  matter,  ^nd  a  laiger 
proportion  of  aah  than  the  remainder  of  the 
com ;  the  endosperm  contains  the  starch  and 
some  reserve  protoid. 

The  six-rowed  barleys,  the  first  two  on  the 
above  list,  are  smaller  than  the  two-rowed 
barleys,  roughly  in  the  'proportion  of  3:4; 
the  proportion  of  endosperm  to  the  remainder 
of  tne  com  is  smaller,  and  consequently  they 
contain  less  starch.  The  chevalier  barleys  con- 
tain a  less  weight  of  skin  (paleie)  than  the 
goldthorpe. 

The  following  table  summarises  the  most 
trustworthy  data  obtained  from  the  analyses 
of  barley.  Whilst  the  relative  amounts  of  the 
constituents  differ,  the  same  substances  are 
present  in  all  ripe  barleys  used  in  malting, 
whether  of  different  varieties,  or  crown  und^ 
different  climatic  conditions.  Baney  may  be 
considered  as  normally  containing  14  p.c.  of 
moisture. 

AVSBA.GX  Composition  ot  Dry  Bablby. 

Starch  .... 
Gums  .... 
Nitrogen  compounds  . 

Sugar  .... 
Fat  .... 

Cellulose  and  fibre     . 
Ash  .... 

The  gums  are  hydrolysable  to  glucose, 
arabinose,  and  xylose  (Lindet,  Compt.  rend. 
1903,  73 ;  O'Sullivan,  Chem.  Soo.  Trans.  1882, 
1 ;  Brown,  Trans.  Guiness  Lab.  1906,  312). 

Nitrogen  compounds,  46  p.o.  are  insoluble 
in  water  and  alcohol ;  36  p.c.  msoluble  in  water, 
but  soluble  in  76  p.c.  alcohol  (hoideine) ;  and 
20  p.o.  soluble  in  water  (leucosin,  edestin,  &c.) 
(Osoome,  Amer.  Chem.  Soo.  1896,  639). 

Sugars  consist  chiefly  of  cane  sugar  with  a 
little  raffinoee  and  glucose  (O'Sullivan,  Chem. 
Soc.  Trans.  1886,  68). 

F(U  contains  78  p.o.  neutral  fat,  14  t>.c. 
free  fatty  acids,  4  p.o.  lecithin,  and  6  p.c.  choles- 
terol (Stellwaag,  Zeite.  f.  d.  ges.  Brau,  1886, 
176). 

Cellulose  and  fibre.  About  one-third  is  true 
cellulose. 

Ash  consists  chiefly  of  silica  and  potassium 
phosphate;  probably  in  the  barley  the  phos- 
phorus is  not  present  as  phosphate  (Windisch, 
C  C.  1906, 1573).  A  lipoid  or  diamino  phospha- 
tide has  been  identified.  Barley  also  contains 
enzymes,  including  a  diastase  of  tnuislocation 
which  does  not  act  on  starch  paste,  but  sacchari- 
fises  soluble  starch  (Kjeldahl,  C.  B.  Lab.  Carls- 
beig,  1879,  129;  Ford  and  Guthrie,  J.  Inst. 
Brewing,  1908,  61). 

Halting  consists  in  the  partial  germination 
of  the  grain,  by  first  steeping  it  in  water,  then 
allowing  it  to  erow  to  a  demiite  amount,  and 
then  stopping  the  process  by  drying  by  heat. 

The  object  in  malting  is  to  so  modify  the 
cell  walls  of  the  endosperm,  and  produce  enzymes 
that  in  the  mash  tun  the  starch  may  be  readily 
dissolved;  to  do  this  with  the  least  loss  by 
respiration  or  rootlet;  without  transforming 
too  much  of  the  insoluble  proteids  into  soluble 
compounds ;  and  avoiding  the  production  of 
nndmirable  decomposition  compounds  by  moulds 
or  bacteria. 


It  is  evident  that  the  first  essential  is  a 
suitable  barley.  Such  a  barley  must  be  mature 
in  the  widest  sense  of  the  word.  If  it  is,  then 
all  the  grains  will,  ^der  the  proper  conditions, 
germinate  evenly.  It  must  be  uniform  in 
size  and  in  composition,  both  chemically  and 
morphologically.  It  must  be  free  from  damaged 
corns  or  foreign  mixL  Other  things  being  equal, 
barleys  with  a  high  nitrogen  content  are  not 
so  satisfactory. 

Elaborate  schemes  have  been  drawn  up  in 
Germany  for  the  valuation  of  barley,  based  on 
a  system  of  marking  of  points,  but  they  are  too 
cumbersome  for  ordinary  practice.  Experience 
enables  a  fair  judgment  to  be  made  of  the 
malting  value  of  a  sample.  Unless  a  barley  has 
been  harvested  under  the  best  climatic  con- 
ditions, it  is  found  that  its  uniformitv  of  germi- 
nation is  improved  by  drying  on  a  kim,  and  this 
is  a  common  practice.  Also  that  storage  for  a 
few  months  alter  harvesting  is  for  the  same 
reason  advisable. 

The  malting  process  is  commenced  by 
steeping  the  ffrain  in  water.  The  steeping 
cistern  is  usual^  of  brick  or  iron,  and  provided 
with  a  perforated  bottom  for  drawing  off  the 
water. 

It  is  usual  to  use  a  moderately  hard  water, 
such  as  would  form  a  good  domestic  supply, 
but  as  some  authorities  advocate  the  adoption 
of  lime-water,  it  would  appear  that  a' slightly 
alkaline  water  is  quite  suitable. 

Two  or  three  days  are  necessary  at  a  tem- 
perature of  10°-13''  a  (60*'-66°  F.) ;  the  thicker- 
skinned  varieties  taking  the  longer  time.  About 
60  p.c.  of  water  is  absorbed,  and  the  grain 
becomes  quite  soft  to  the  finger-nail. 

One  of  the  inner  coatings  of  the  barley  grain 
is  semi-permeable,  and  will  not  allow  any  of 
the  soluble  constituents  to  pass  from  the 
interior,  nor  admit  anythine  but  pure  water 
from  such  waters  as  are  likely  to  be  employed 
for  steeping  (A.  J.  Brown,  Proc.  Roy.  Soc. 
1909,  81).  A  considerable  amount  of  matter  is 
extracted  from  the  surface  and  outer  skin  of 
the  grain,  and,  of  course,  from  the  interior  of 
damaffed  corns.  As  numerous  bacteria,  &c., 
are  uways  adherent  to  the  surface  of  the 
barley,  the  water  soon  becomes  putrid,  and  it  is 
therefore  customary  to  change  the  steep  water 
several  times. 

The  drawing  off  and  renewal  of  the  water 
aerates  the  steeping  barley,  and  this  is  found 
to  be  beneficial. 

Too  long  a  steeping  impairs  the  vitality  of 
the  com,  and  too  diort  does  not  allow  sufficient 
water  to  be  absorbed  to  carry  on  the  germination 
sufficiently. 

It  is  probable  that  germination  commences 
durinf  steeping,[but  the  amount  of  change  is  small. 

Aner  steeping,  the  grain  is  thrown  out  of 
the  cistern  on  to  the  growing  floors.  These  are 
made  of  cement  or  tifes.  Chitting  soon  begins, 
leading  to  the  production  of  rootlets,  and  the 
plumule  begins  to  grow.  Owing  to  the  adherence 
of  the  paleae,  the  plumule  grows  up  the  side  of 
the  com  under  these,  and  does  not  emeree 
until  it  reaches  the  distal  end  of  the  grain.  The 
rootlets  emerge  from  the  proximal  end  of  the 
grain.  These  outward  appearances  of  gennina- 
tion  are  accompanied  by  profound  change  in  the 
interior  of  the  grain. 


672 


BREWING. 


Germination  is  an  enzymio  prooess  of 
demolition,  followed  by  a  building  up.  The 
embryo  secretes  enzymes,  which  breal  down  into 
a  soluble  form  the  reserve  inatters  of  the  endo- 
sperm, and*  utilise  them  for  its  growth.  So  at 
any  stage  before  germination  is  complete  there 
will  be  a  whole  series  of  compounds  present  in 
the  grain  from  complex  to  simple,  and  again 
from  simple  to  complex. 

One  enzyme,  CyUise,  attacks  the  walls  of  the 
starch  cells ;  this  action  is  most  important,  as 
on  its  completeness  depends  the  tenderness  of 
the  malt.  The  walls  of  the  starch  cells  of 
various  barleys  differ  materially  in  their 
tendency  to  ready  dissolution.  Generally  those 
barleys  most  prized  for  malting  are  those  in 
which  the  cell  walls  give  way  most  easily.  These 
cell  walls  must  be  broken  down  before  the 
starch  is  available;  the  products  of  their 
transformation  form  an  important  food  for  the 
first  growth  of  the  young  plant.  This  dis- 
solution not  only  preceaes  starch  dissolution,  but 
proceeds  more  rapidly,  and  this  fact  renders 
it  possible  to  attack  the  greater  parts  of  the 
cell  walls  before  the  starch  is  to  any  ereat 
extent  dissolved.    The  diagram  (Fig.  3)  shows 


o 
Fio  3. 

the  process  (Brown  and  Morris,  Chem.  Soc. 
Tran9.  1890,  469).  A  at  3  days,  B  at  6  days, 
C  at  10  days. 

Amylase  attacks  the  starch  and  transforms 
it  into  sugfirs,  part  of  which  are  still  found  in  the 
finished  malt,  part  utilised  by  the  embryo  and 
part  oxidised  oy  respiration  to  carbon  dioxide 
and   water.    Proteolytic   enzymes   attack   the 


reserve  protoplasm  (Weiss,  C.  G.  1904,  385); 
there  are  probably  also  fat  splitting  enzymes,  fte. 

These  changes  are  affected  by  temperature, 
amount  of  moisture,  aeration,  and  tiie  business 
of  the  maltster  is  to  control  them.  Tids  he 
does  by  turning  the  malt,  spreading  it  in  thick 
or  thin  layers,  sprinkling  it  with  water,  and 
regulating  the  temperature  of  the  malthouse  as 
b^  he  may.  If  the  temperature  be  allowed  to 
rise  above  12°-13°  (56''  F.),  increased  enzyme 
action  leads  to  larger  rootlet  production  'and 
respiration  losses.  Increased  temperature,  ae- 
companied  by  increased  moisture,  leads  to 
increase  in  both  proteid  and  starch  degradation 
products  in  the  finished  malt  (Brown,  J.  I.  Br. 
1909,  190).  If  too  much  water  be  given  the 
plumule  (acrospire)  flprows  too  fast.  Both 
excess  and  deficiency  of  water  reduce  oxidation 
and  rootlet  growth.  If  the  carbon  dioxide  of 
respiration  is  too  much  dispersed  by  excessive 
turning  and  the  grain  is  too  much  sired,  there 
is  excessive  respiration  loss.  Too  little  oxygen 
impairs  the  necessanr  germinative  chutes 
(Schjeming,  C.  R.  Lab.  Carlsbeig,  1910,  169; 
Brown,  J.  Inst.  Brewing,  1907,  394;  and  1909, 
170).  The  grain  having  grown  several  bushy 
rootlets,  and  the  acrospire  from  2/3  to  3/4  up 
the  grain,  it  should  have  arrived  at  the  proper 
state  of  endosperm  modification ;  that  is,  the 
cell  walls  should  be  broken  down.  10**- 13** 
(50°^5°F.)  is  considered  the  most  satisfactory 
growing  temperature  (Day,  G.  J.  1891,  664; 
Blaber,  Brewers  J.  1907,  369;  Weiss,  C.  G. 
1904,  373).  The  time  on  the  floor  necessary  for 
this  is  from  10  to  12  days  at  the  usual  mslting 
temperature  (60°-66°F.),  the  thin  six-rowc^ 
varieties  take  longer.  Some  Continental  maister^ 
floor  the  malt  For  a  shorter  time,  but  they 
are  satisfied  with  a  less  modified  malt. 

In  order  to  save  the  considerable  amount  of 
labour  and  space  necessary  in  a  floor  malting, 
and  to  obtain  more  command  over  the  tempera- 
ture, several  other  germination  methods  have 
been  devised  ;  these  go  by  the  genend  name  of 
pneumatic  malting.  The  steOT>ed  barley  is 
placed  in  rotating  drums  which  are  supplied 
with  cooled  saturated  air,  the  amount  of  which 
may  be  regulated  at  will.  The  difficult  is, 
that  in  cooling  the  malt  by  a  current  of  air 
excessive  respiration  takes  place,  and  this 
often  at  the  later  stage  of  germination,  when  a 
check  on  respiration  is  most  necessary.  A 
method  of  overcoming  this  is  to  conduct  the 
final  stage  of  germination  in  the  drum  or  in  a 
box  in  which  the  carbon  dioxide  is  allowed  to 
accumulate. 

The  grain  is  now  ready  for  the  next  prooees 
that  of  dmng. 

The  kiln  consists  of  a  tall  building  adjacent 
to  the  growing  floor.  On  the  ground  floor  is 
one  or  more  fire  baskets  for  burning  coke  or 
anthracite  coal,  or  a  furnace  for  heating  air  in 
case  the  drying  is  to  be  done  without  bringing 
the  products  of  combustion  in  contact  with  the 
malt.  The  former  is  the  British  plan,  the  laUer 
the  Ck>ntinental  Above  the  fire  baskets  or 
furnace,  is  a  floor  or  two  floors  of  perforated 
tiles  or  wire  mesh,  on  which  the  grain  to  be 
dried  is  loaded,  and  above  is  a  roof  with  a 
cowl  or  other  suitable  ventilating  appUaaoe 
with  adjustable  openings.  The  air  infets  on 
the  ground  floor  are  also  capable  of  Relation. 


BREWING. 


673 


If  the  kiln  has  two  floora,  the  drying  is 
begun  on  the  top  floor  and  finished  on  the 
bottom  floor. 

The  malt  beinff  loaded  in  the  kihi,  the 
temperature  is  slonny  raised  so  that  about  66°- 
66°  (160°  F.)  is  reached  in  three  days,  when  the 
temperature  is  further  raised  to  93°-04°  (200°  F.) 
more  or  less,  dependent  on  the  kind  of  malt 
that  is  being  dried. 

Owin^  to  the  slow  rise  of  temperature, 
germination  continues  during  the  earlier  stages 
of  drying;  but  as  the  temperature  increases 
the  vitality  of  the  com  is  destroyed,  the  enzymes 
being  reduced  or  altered.  The  amount  of 
diastase  in  the  dry  malt  is  1/3  to  1/4  of  that  in 
the  green  malt.  In  the  last  period  empyreu- 
matio  products  are  produced  by  the  caramelisa- 
tion  of  the  carbohydrates  and  proteids,  and  the 
well-known  bisouity  flavour  appears.  In  order 
to  produce  this,  the  temperature  and  moisture 
must  have  a  certain  correlation.  Too  much 
water  at  a  high  temperature  would  produce  a 
cooked  product,  and  too  little,  not  sufficient 
caramelisation. 

If  the  products  of  combustion  are  allowed 
to  come  in  contact  with  the  malt,  care  must  be 
taken  that  the  fuel  used  is  free  from  arsenic. 
Coal  and  coke  nearly  always  contain  some,  so 
that  that  variety  must  be  selected  which  does 
not  contain  more  than  1/20  grain  arsenic  per 
pound. 

When  the  malt  is  dry,  it  is  removed  from 
the  kiln  and  passed  through  a  machine  which 
first  detaches  the  rootlets  by  beaters,  and  then 
separates  them  from  the  malt  by  screens.  When 
cool,  the  malt  is  stored  in  air-tight  bins  until 
required  for  use  in  the  brewery.  If  exposed  to 
damp  air,  it  absorbs  moisture  and  deteriorates. 

The  rootlets  or  '  culms  *  form  a  valuable 
cattle  food,  a  large  part  being  digestible.  Their 
composition  is : — 


Fat 

Proteids  . 
Carbohydrates  * 
Cellulose  and  fibre 
Ash     . 


1-2    p.0. 
24-28 
42-48 
11-16 

6-7 


>* 


»» 


»t 


fi 


100  parts  dry  Chevalier  barley  yield  on  the 
average  89  parts  malt ;  4  p.c.  is  lost  in  rootlets, 
and  7  p.c.  in  respiration  (£.  S.  Beaven,  J.  Inst. 
Brewing,  1902,  687). 

The  changes  which  take  place  when  barley 
is  converted  into  malt  are  complex.  In  a 
normally  malted  barley  about  60-70  p.c.  of  the 
nitrogen  compounds  are  in  some  way  altered, 
and  about  36-40  p.c.  have  passed  from  the 
endosperm  to  the  embryo.  Some  of  the  nitro- 
genous compounds  are  removed  with  the  rootlet, 
so  that  malt  always  contains  less  than  the  barley 
from  which  it  is  made.  On  the  whole,  a  large 
proportion  of  the  insoluble  albuminoid  of  barley 
IS  still  insoluble  in  the  malt ;  the  hordein  is 
partly  converted  into  a  similar  body,  hynin, 
and  partly  into  soluble  nitrogenous  compounds 
of  lower  molecular  weight. 

The  soluble  bodies  are  further  degraded. 
About  40  p.c.  of  the  nitrogenous  bodies  are 
permanently  soluble  on  mashing.  The  nitrogen 
m  the  non-coagulable  nitrogenous  matters  of 
malt  soluble  in  cold  water  is  distributed  as 
follows :  (H.  T.  Brown,  J.  Inst.  Brewig,  1907, 
413): 

Vol.  I.— T. 


Ammonio  nitrogen 
Albumose  nitrogen 
Peptone  nitrogen 
Amide  and  amine  nitrogen  ^ 
Oivanic  bases  nitrogen 
(betaine,  choline)    . 
Unaccounted  for 


3-6 

p.c. 

20 

»» 

31 

>• 

8-6 

't 

4 

ft 

33 

•■ 

100 


When  mashed,  the  soluble  nitrogen  sub- 
stances ^m  be  increased  about  60  p.c 
Schjeming  (C.  R.  Lab.  Carlsbeig,  1910,  387) 
states  that  20  p.c.  of  the  total  nitrogen  of  the 
malt  should  be  tryptic  decomposition  products 
(ammonia,  amine-amid),  and  that  6  or  6  p.c. 
of  the  total  nitrogen  amount  occurs  in  the  wort 
as  albumin  (leucosin).  About  one- third  of 
the  total  nitrogen  of  the  malt  is  soluble  on 
mashing. 

From  16  to  18  p.c.  of  the  starch  has  been 
transformed  into  sugars— the  greatest  portion 
(9-16  p.c.)  is  found  in  the  malt,  a  portion  has 
been  utilised  by  the  drowning  embryo,  another 
portion  is  removed  by  the  rootlet,  and  some 
nas  been  lost  by  respiration. 

Malt  is  always  more  acid  thim  barley,  and 
it  has  been  suggested  that  as  it  usually  contains 
less  fat  than  barlev,  a  portion  of  this  is  due  to 
saponification  and  corresponding  liberation  of 
fatty  acid.  The  increased  acidity  has  also 
been  attributed  to  the  work  of  acid-forming 
bacteria  during  the  flooring  and  early  stages^ 
the  drying. 

Malt  contains  fats  containing  free  fatty 
acids  and  unsaponifiable  matter;  also  a 
lipoid  (diaminophosphatide)  (Liiers,  Zeitsoh. 
ges.  Brau.  1916,  97,  126). 

Malt,  like  barley,  contains  amylans  or  gums, 
but  we  know  nothing  of  the  change  produoed 
in  these  by  malting. 

The  cellulose  and  fibre  are  very  slightly,  if 
at  all,  affected  by  the  malting  process. 

There  is  a  little  less  ash  in  malt  than  in 
barloy,  as  the  steep  water  dissolves  about  one- 
tenth  of  it;  the  constituents  are,  however, 
unaltered. 

One  of  the  most  important  facts  for  the 
brewer  is  the  proportion  of  the  malt  soluble  in 
the  mash  tun.  This  includes  all  the  water- 
soluble  compounds  of  the  malt  and  those  trans- 
formed into  soluble  compounds  by  enzymes  at 
the  mashing  temperature.  The  chief  of  these 
is  starch,  but  some  of  the  insoluble  nitrogenous 
substances  are  also  rendered  soluble. 

The  *  extract  *  varies  from  76  p.o.  or  more 
for  the  best  two-rowed  varieties,  such  as 
English,  Hungarian,  &c.,  to  70-73  p.o.  for 
Califomian  and  Smyrna,  and  is  as  low  as 
66  p.c.  for  some  of  the  very  thin  six-rowed 
North  African  varieties. 

There  is  probably  more  than  one  amylase, 
perhaps  two ;  one  liquifies,  and  one  sacchari- 
nes ;  out  there  may  be  more.  It  is  said  that 
amylase  may  be  extracted  by  a  60  p.c.  aqueous 
solution  of  glycerine  or  a  3  p.c.  aqueous  solution 
of  pyridene,  and  that  such  extracts  will  retain 
theor  activity  for  years.  Maltase  is  also  present 
(Marino  and  Fiorentino,  Gazz.  chim.  itai.  1906, 

^  Chiefly  asparagine,  a  Utile  toudne  and  tyioBlne 
and  a  trace  of  aUantoIn. 

2  X 


396;  Davis  and  ling,  Chem.  Soo.  Tnna.  1904, 
16). 

A  proteolytic  and  tiro  pepbolytic  enzymes 
ore  present,  the  former  with  an  optimunk  tem- 
perature of  58°-68°  C,  and  the  Utter  26°-3T'  C, 
the  Brat  U  deetxoyed  and  the  others  greatly 
weakened  at  50°  C. 

Also  peroxidase  and  catalasee  which  exist 
in  ba,riev  inoreaae  during  germination  uid 
decisase  by  kilning  (Van  Laer,  J.  Inst.  Brewing, 
1906,  313  i  -  Schjeming,  C.  R.  Lab.  CarUberg, 
1910,  200). 

Malt,  as  it  leaves  the  kiln,  is  free  from 
moisture,  but  on  exposure  it  quickly  absorbs 
B  small  percentage.  C^re  must  be  taken  that  this 
doee  not  exceed  3-4  p.0.,  or  the  malt  becomes 
alack  and  deteriorateB.  Unknown  (possibly 
proteolyUo)  changes  take  place  which  render  it 
unfit  for  brewing. 

As  already  stated,  a  portion  of  the  malt  is 
often  replaced  by  substitutee.  In  1915  British 
brewers   used  7(1   p-o,   malt,   1   p.c.    unmalted 

5r^n,  6  p.0.  maize,  rice,  and  other  preparations, 
6  p.0.  BDsars.  American  brewers  used  large 
amounts  of  raw  grain  or  maize  grits.  German 
biever*  in  pre-war  days  used  no  malt  sub- 
stitutee, but  some  used  partially  malted  barley, 
which  more  nearly  resembled  barley  than  malt. 
Although  no  doubt  unmalted  grain,  maize,  rioe, 
and  tbeir  preparations  are  u^  on  the  score 
of  economy,  the  same  cannot  be  said  of  the 
sugar ;  the  use  of  this  is  considered  to  yield  a 
beer  that  ctarilies  quicker,  but  the  chief  reason 
is,  that  a  fuller  (sweeter)  beer  is  obtained.  This 
is  what  the  public  demands. 

Maize,  nca.  and  their  preparations  are  used 
either  as  grits,  consisting  of  the  broken  up 
endosperm  free  from  the  germ  and  coverings,  or 
as  the  same  material  flaked,  i.e.  a  form  in 
which  the  starch  has  been  partly  gelatinised 
by  moisture  and  heat. 

The  sQgars  in  common  use  are  raw  cane 
sugar  (not  raw  beet  sugar,  which  contains 
nauseons  impurities),  refined  cane  sugar,  invert 
sugar  prepared  by  inverting  with  weak  acid 
raw  cane  sugar  and  purifying  the  product,  and 
glucose  prepared  by  the  action  of  acid  on 
stareh  (q.v.). 

Hop!  give  to  beer  its  well. known  flavour,  and 
act  as  a  preservative.     They  also  fulfil  other 
important  functions  in  the  coarse  of  brewing. 
A    characteristic    pecu- 
liarity of  the  bitterness 
of  hops  is  that  it  is  tran- 
sient, after  the  beer  is 
swallowed  the  bitterness 
at  once  passes  away. 
)       Thenpefemaleflower 
is  the  part  used  in  brew- 
'  ing.     This  consists  of  a 
cone  of  bracto  (6).     At 
the  base  of  the   bracts 
are  the  seeds  and  lupulin 


Fio.  4. 


in   the  Continental  gar- 
dens the  hops  are  seed- 
(Fiim  Pereitaft  i/riail- \eaB_    Enalish  and  Ame- 
£co)  i™™»™"  naa.n    hops   are   seeded 

owing  to  the  presence  of 
a  few  mate  plants  in  the  gardens.  There  are  good 
reasons  for  both  these  practices,  dependent  on  the 


variety  of  hops  grown.  In  an  experiment  made 
on  English  hops  it  was  found  that  seeded  hops 
contained  Ifi  p.c.  lupulin  compared  with  17  p.c 
in  the  same  variety  seedless,  but  as  tbs  yield 
was  much  larger  m  the  first  case,  147  Ifaa. 
lupulin  per  acre  were  obtained  in  tlw  one  case 
against  92  lbs.  in  the  other. 

The  brewing  value  of  the  hop  depends  msinly 
on  the  lupulin.  The  amount  varies  very  greatly, 
from  a  few  p.o.  up  to  as  much  as  20  p.0.  of 
the  weight  of  the  hop.  It  contains  onnential 
oil,  wax,  raainB,  and  one  or  more  alkaloids, 
Ac. 

The  eaaenUal  oil  forms  0-2-0-8  p.o.  of  the 
hops.  It  is  easily  soluble  in  alcohol  and  ether, 
but  only  in  600  parts  of  water.  Its  principle 
oonstdtuents  are  an  aliphatic  hydrocarbon 
myreeae  Ci«U,^  b.p.  ie6°-16S°,  and  a  sesqui- 
terpene humvUtu,  b.p.  263°-266°,  these  form 
80-90  p.o.  of  the  oil.  There  are  also  oenanthylic, 
oaprybc,  and  pelargonio  ethers  of  myreenol 
(CioH,,OH)  (Chapman,  Chem.  Soo.  Trans. 
189G,  783 ;  1903,  505 ;  and  Babak,  J.  Inst. 
Brewing,  1916,  76). 

Host  of  the  oil  is  volatilised  when  hops  are 
boiled  with  the  wort,  but  as  hops  are  also  added 
to  the  finished  beer,  the  oil  &om  these  latt«r 
wiU  remain. 

The  resin  is  sud  to  consist  of  two  orratollis- 
able  slightly  acid  bitter  substanoes  solnble  in 
petroleum  spirit,  named  the  >-  and  3-reHiDB,  and 
areain(r-resiu)  Insoluble  in  petroleum  spirit,  but 
soluble  in  alcohol  and  not  [ffeaiiatatea  by  lead 

All  three  are  soluble  in  ethyl-ether  and 
methyl-alcohol. 

The  a-acid  C„H,gO„  m.p.  66°  0.,  precipiUbte 
by  alcoholic  lead  acetate,  may  be  oxidised  to 
valeric  acid,  the  ^-aoid  not  precrpitated  by  this 
reagent  is  C„U,.0„  m.p.  92°~93°  C,  on  oxida- 
tion yields  B  ydlow  resm ;  the  7-acid  is  stated 
by  some  authorities  to  be  tasteless  and  volnelo* 
in  brewing,  and  by  others  to  have  a  slight  bitter 
flavour  and  to  be  capable  of  coagulatmg  some 
albuminoids  from  w<»ts. 

Authorities  differ  aa  to  which  of  the  first 
two  are  the  more  valuable  in  brewing ;  tbe 
P-  acid  is  usually  present  in  largest  amount. 
Both  of  these  ore  easily  changed  by  heat  or 
storage  into  insoluble  and  presumably  less 
valuoUe  resins.  The  a-  and  3-  or  soft  resins 
may  be  estimated  in  hops  by  extraction  with 
petroleum  spirit,  which  also  extracts  the  wax  ; 
this  may  be  removed  by  extracting  with 
methyl  ether,  in  which  the  wax  is  iosolnblc, 
and  weighing  the  amountextrocted  ;  or  titralinK 
this  with  N/,gKOU,  using  phenolphthaletn  and 
taking  1  c.o.  of  normal  potash  as  equal  to  0'40 
gram  resin.  There  is  considerable  discrepancy 
concerning  these  reoins  in  the  literature  of  the 

About  2-5  p.c.  of  tauuin  is  present  in  hope  j 
whether  this  is  of  value  as  an  albuminoid  pre- 
cipitant is  uncertain.  Hops  also  contain  0'6- 
1  p.c  nitrogen  compounds  soluble  in  hot  water 
(Chapman,  Chem.  Soc  Trans.  1914,  1895  and 
S79).  Small  quantities  of  alkaloids  are  present 
in  hops,  and  choline  baa  been  idenUSea;  aJ«o 
carbohydrates,  fibre,  ash,  and  moisture.  An 
oil  can  be  extracted  from  the  seeda.  Hops 
contain  diastase. 

Power.  Tutten,  and  Eogerson  (Chem.  Soo. 


Trana.  1013,  1291)  examined  the  alcoholic 
extract'  which  wu  insoluble  in  water  and 
amounted  to  I4'l  p.o.  of  the  hops  examined. 
These  were  New  Kent,  containing  10  0  p.0. 
wkter.  2'4  p.o.  tannin,  T'9  p.o.  Mh.  Tney 
isolated  from  it : — 

Ceryl  alcohol  Cj,H,|0,  hentricontane  C„U,„ 
A  phytoflWrol  Cj,H,,0,  A  phytoslerol  gluoodde 
C„H„0,.  A  miiture  of  volatile  fatty  acids,  con- 
sisting of  formic,  acetic,  butyric,  valeric,  and  a 
heienoic  C.H.oO,,  b.p.  2O4''-208°,  and  idenUfied 
as  6-tsopropyliicijiio  acid  and  a  little  nonoic 
~  acidC,H,,0,i  saturated 

and  unsat  orated  non- 
volatile acids,  including 
palmitic,  stearic,  and 
ceTOtic  acids,  and  an  acid 
C„H,,0„  m.p.  626°- 
63°,  appareotly  od  iso- 
meride  of  arachidic  acid, 
cluytonio  aoid  C  i|  H^  ,0 1, 
m.p.  69° ;  humulol 
C,,H„0„  m.p.  106°, 
with  a  bitter  t^te ;  and 
xanthohnmol  C|,H,40|, 
~.p.  172°,  tasteless. 
*t  thus  appears  that 
mess  of  hops  is 
oanjiinglesab- 

!  at  is  to  be  attri. 

tnamberofpro- 


H  xanthol 

f  J  ■■  It    t 


>st  of  which  Bi 


well -defin- 
ed    bitter 
,   Bubstanco, 
'   humvtol, 
has,   how- 

isolated. 


The   antiseptio   Talae   of 
hops  is  considered  to  be  due 
to  the  soft  (a-  and  B-]  reeins, 
but  experimente  made  on  the 
toxio  power  of  aqueous  hop 
extract  on  baotena   do  not 
alt<^elher   confirm   this.     It 
was  found  that  the  volatile 
constituents    have   no   anti> 
septic  power,  that  Gve-sizths 
of  the  antiseptic  power  was 
extracted  by  one  hour's  boil- 
ing with  water,  but  that  under 
these  conditions  not  much  of  the  soft  reeina 
wsa  extracted,  and  the  portion  extracted  seemed 
to  be  changed  to  the  uard  or  insoluble  resin. 
The  antiseptic  substanoe  was  present  in  true 
solution,  and  compared  with  other  antiseptics 
was   weight   for   weight   more   toiio   to   beer 
bacteria  than  salicylic  acid  or  potassium  meta- 
bisulphite  (Brown,  J.  lost.  Brewing,  1910,  641  ; 
and  lel3,  261). 

It   thus   appears   that   the   nature   of   the 

Sreservative  substance  of  bops  is  still  to  be 
etermined,  and  that  the  value  of  the  resulte 
obteined  from  e«timatioiw  of  the  so-called  hard 


TSa.  873 

and  soft  resins  is  doubtful.  In  practice  Mnpuical 
methods  ore  employed  for  valiung  hops.  These 
are  based  on  the  '  feel '  and  '  aroma '  of  the 
hops  when  rubbed  between  the  hands.  This,  in 
experienced  hands,  enables  a  judgment  to  be 
made  of  flavouring  and  preservative  values. 
It  seems  likely  that  the  judgment  so  arrived 
at  on  the  preservative  power  is  often  erroneous  ; 
but  in  the  present  state  of  the  chemistry  of  the 
hop  no  more  trustworthy  means  is  available. 

Hops  are  sometimes  contaminated  by  arsenic 
derivea  from  the  fuel  used  in  the  kUns  in  which 
(hey  are  dried.  To  avoid  this,  hot  air  is  often 
Dsed,  the  actual  combustion  products  not  coming 
into  contact  with  the  bops.  Hope  are  asuoLy 
exposed  to  sulphur  dioxide  when  drying  in  the 
kiln.     This  improves  their  colour  and  otherwise 

Spears  to  have  no  ill  effect.  Free  sulphur  is 
o  found  in  hops  ;  this  is  due  to  the  apphoation 
of  sulphur  to  the  hop  plant  for  the  prevention 
of  mould,  or  may  possibly  occur  when  sulphuring 
hops  on  kiln  by  incomplete  oombustion  and 
Tolatilisation  of  some  sulphur. 

Sulphur  is  transformed  b^  ^eost  into  sul- 
phuretted hydrogen,  which,  if  mtroduced  into 
the  finished  beer,  may  spoil  the  flavour.  It  may 
be  detected  and  estimated  by  the  amount  of 
stain  produced  by  the  evolved  gases  on  lead 
paper. 

PatenI,  roatUd,  hiadc,  or  ekocalatt  nutt  is 
made  by  roasting  already  prepared  and  usually 
short  grown  malt  in  a  rotating  cvlinder.  Ten 
p.o.  of  this  malt  gives  to  st«nls  ana  porters  their 

Brown  malt  is  dried  in  a  special  kiln,  on 
which  a  high  finishing  temperature  is  obtained, 
beech  wood  being  the  fuel  used. 

Amhtr  and  crystal  malt  are  prepared  by 
heating  malt  in  cylindera,  but  the  roostiog  is 
much  less  than  in  the  preparation  of  block 
I  malls.     Brown,     amber,    and    crystal    malts, 

ive  colour  to 

by  healing 
d  for  colour' 
The  heating 

9  presence  m 
ks  in  this  way 


(Chem.  Soc.  Trans.  1917, 589-608).  V.  Caumil. 
The  first  stage  of  actutd  brbwinq  ii  the 
grinding  of  the  malt.  If  the  malt  were  com- 
pletely modified,  that  is,  if  the  cell  walls  of  the 
starch  cells  were  completely  disint«grated,  this 
would  be  a  comparatively  easy  matter,  and  the 
simple  method  of  j  ust  crushing  the  grain  between 
two  plain  iron  rollers  would  be  all  that  is  neces- 
sary. Although  malt  never  is  perfectly  modified, 
yet  much  that  is  made  is  sufficiently  so  for  this 
method  to  be  employed  in  many  brewerie*. 
Still  even  with  the  best  malts,  when  omshed  by 
this  method,  it  U  possible  to  detect  starch  in 


the  regidiie  r 


1  the  maih  tun  aiter 


>  the 


fuel,  u  has  olroady  been  described,  that  dii- 
Bolalion  of  the  cell  wall  prooeeda  from  the 
proximal  to  the  distal  end  of  the  grain ;  Mid 
that  oa  even  the  finest  bu'leye  do  not  terminate 
absolutely  evenly,  to  avoid  e»eea«ivo  loas  from 
overgrown  conu,  the  procees  must  be  Btopped 
in  many  corns  before  iti  completion,  bo  that 
there  must  be  a  Dumber  of  oonu  coDtoining  », 
■mailer  or  greater '  hard  end.' 

In  order  to  reduce  these  '  hard  ends  '  to  a 
condition  in  which  they  will  dissolve  in  the  maah 
tun,  they  tnuit  be  finely  ground.  If  the  whole 
com  were  finely  groond,  the  extraction  wonld  be 
so  slow  as  to  make  the  prooeas  unworkable. 
Mills  have  therefore  been  devised  in  which  the 
roughly  crushed  malt  is  separated  by  sieves  and 
air  onirenta  into  vaiioua  portions,  and  the  grita 
and  hard  ends  finely  ground  and  re-miied  with 
the  remainder  of  the  crushed  malt.     Fig.  6  is  a 


is  brushed,  beaten,  exposed  to  a  current  of  air, 
and  sieved.  Thus  stones,  surface  dirt,  straw, 
weevily  (empty)  corns,  and  other  Coreign  bodies 

The  ground  malt  is  collected  in  reoeiTers 
(malt  hoppers  or  grist  cases)  until  the  amount 
required  for  the  brew  is  complete.  These 
receivers  command  t^e  maoh  tun.  the,  vessel  in 
which  the  malt  and  water  are  mixed. 

Fig.  0  is  a  diag^nnmatic  representation  of  the 
mashinK  side  of  a  brewery. 

hiash  tuns  (Fig.  7)  consist  of  wood  or  iron 
vessels  fitted  with  false  bottoms  of  perforated 
metal  plates.  Pipes  are  connected  with  the 
bottom  of  the  tub  for  drawing  oS  the  extract 
(wort).  In  the  npper  portion,  or  above  the 
tun,  are  inlete  for  the  malt,  hot  and  cold  water ; 
and  Ml  underlet  for  hot  water  is  usually  inserted 
in  the  bottom  of  the  ton.  The  tun  is  generally 
provided  inth  miring  gear  ('  ium  ').  A 
•parger  for  sprinkling  hot  water  on  the  surface 


of  Uie  mash  is  required,  so  that  the  grains  may 
be  thotoogbly  extracted. 

At  the  proper  time,  water  at  a  pte-deter- 
mined  temperature  and  the  ground  malt  are 
mixed.  Ttus  is  done  either  1^  flacinK  in  the 
mash  tun  sufiicient  hot  water  and  admitting 
the  matt  with  oonsttut  stiiTing,  or  the  malt  and 
hot  water  are  admitted  together  through  a 
special  miTing  machine,  a  *  steel  ^  masher  Being 
the  one  in  common  ose  (Fig.  8).  The  maaE 
may  now  be  treated  by  the  '  inAuion  '  («  the 
'  decoction  '  system. 

The  infuKon  system  is  empkyed  in  the  prO' 
dnotion  of  British  beers.  The  mash  (tempera 
ture  about  6S°-66'  (ISO°F.))  is  simply  allowed 
to  stand  for  a  couple  of  hours,  and  the  infusion 
then  drawn  off,  iJie  insoluble  rMidue  (brewcn 
grains)    is    exhausted    by    spoiling    with    hot 

The  decootion  system  is  employed  for  the 
production  of  '  lager '  beers.  The  malt  is 
usually  mixed  with  water  to  give  a  compara- 
tively low  temperature  mash,  3fC-i9'  (100°- 
120°  F.)  (sometimee  cold  water  is  need),  and 
allowed  to  stand  at  this  temperature  for  a 
couple  of  hours;  no  starch  degradation  takes 
place,  but  it  is  a  favourable  temperature  for 
proteid  transformationa.  About  one -third  of 
the  tiiiok  mash  from  the  bottom  of  the 
tun  is  run  into  a  ooppet  (mash-co[iper) 
and  than  boiled  for  half  an  hour,  after  which 
it  is  returned  to  the  maah  tuna ;  this  raises 
the  temperature  of  the  whole  about  30°  F. 
After  another  interval,  a  further  portion  is 
withdrawn  and  boiled  and  returned  to  the 
mash  tun,  and  this  agam  repealed  if  re- 
quired, liie  maoh  is  then  treated  as  by  the 
infusion  system. 

Instead  of  being  extracted  in  maah  tuns, 
the  mash  may  be  pumped  into  a  Biter  press, 
and  in  this  way  the  wort  separated  from 
the  insoluble  residue.  Special  presses  have 
been  deaigned  for  the  purpose.  Loiser  extracts 
are  obtained,  as  it  is  possible  to  deal  with  finer 
ground  malt. 

When  the  mixture  (mash)  is  first  made, 
there  is  a  rise  of  temperature  of  S!°-3°  F. 
due  to  hydration  or  adsorption;  the  drier 
the  malt,  the  more  heat  is  evolved.  Starch 
transformation  causes  a  riw  of  Ov"  F.  Im- 
portant entymic  changes  take  place  in  the 
maah.  The  chief  of  these  is  the  saccharificatioD 
of  the  starch.  There  ore  also  important 
proteolytic  changes  and  other  less  important 
en^matic  actions.  Thc«e  changes  are  inflneiioed 
by  the  temperature,  fineness  of  grinding,  orooont 
of  dilution,  duration  of  the  process,  and  com- 
position of  the  mashing  water,  Ac.  The 
temperature  has  a  great  influence  on  the 
character  of  the  stsjroh  transformation  {>er 
Stareh).  Brewery  moshee  are  usually  carried 
out  between  63°  and  68°  (I4(>°  and  165°  F.). 
and  about  four-fiftiia  of  the  stareh  is  ccmverted 
into  maltose ;  C6°-efl°  (160°  F.)  is  tlie  optunom 
temperature  for  quantity, 

Proteid  translonnation  is  most  active  at  • 
lower  temperature,  ib'Stf  (113°-131°F.).  but 
the  action  continues  up  to  about  77°  (170°  F.). 
From  6  to  12  p.c.  of  nitrogen  oompounda  ar« 
rendered   soluble  at  06°  (l^W'F.),  and  if    the 


in     the     production     of     mora     lovei'  -  grade  1 

The  fineneu  of  grinding,  as  has  already  been  I 

Eomt«d  out,  will  aSect  the  amount  of  extract,  | 
ut    the    conpoution    of 
the  wort  is  not  otherwise 
afCealed. 

The  extract  increase! 
with  the  atnoont  of  dilu- 
tion op  to  6  water  to  I 
malt,  after  which  it  de- 
creases. This  is  due  to  an 
increaae  in  tbo  quantity  o( 
BUrch  Bocchiuified,  as  the 
amount  of  proteid  trans- 
formation  decrease*  with 
the  dilution.  All  the  en- 
lyme  actions  reach  their 
maximum  amount  within 
the  first  hour,  or,  at  mosl. 

The  efloct  of  alterationH 
of  the  mashing  water  has 
already  been  described ;  i 
the  more  sparging  water  is 
used  for  extracting,  the 
greater  is  the  amount  ot 
nitrogen  compound  ex- 
tmcted.  For  this  reason 
brewers  do  not   press  the 

When  nw  grain  or  grits 
aie  used  as  substitute  for  a  portion  of  the  malt,  the  I 
starch  of  theee  must  be  Srst  gelatinised  by  boil- 
ing, and  this  when  mixed  with  the  mash  is  sac-  I 
chatified  by  maltdiastase.  It  is  stated,  however,  ' 
that  if  the  material  is  finely  ground,  the  starch 
can  be  saccharified  in  the  mash  tun  by  the  malt 
diastase  without  previous  boihng.  flaked  grits 
will  saccharify  in  the  mash  without  previous 
boiling. 

Sugars  ore  usually  added  to  the  wort  in  the 
copper. 

The  drafl  or  '  grains  '  remaining  In  the  mash 
tun  after  extraction  is  completed,  forms  a 
valuable  cattle  food. 
It  may  be  used  fresh, 
and  then  contains 
about  TO  p.c.  water; 
in  this  state  it  does 
not  keep  well.  ]f 
dried,  it  keeps  In- 
definilely. 

The   composition 
of    the    dried    pro- 


said  to  be  used  for  this  purpose)  and  heated  by 
fire  or  steam.  The  amount  of  bops  used  varies 
with  the  quality  of  the  beer  to  be  brewed. 
Ordinsiy   mild   alee   require   about   I    lb.   per 


barrel,  bitter  l>eera  from  two  to  three  times  this 
quantity,  and  export  and  strong  ale*  still  more. 
The  average  amount  used  in  the  United  Kingdom 
in  1914-16  was  1}  lbs.  per  barrel.  Lager  beer 
brewers  use  about  }  lb.  hops  per  borreL 

Boiling  with  hops  destroys  the  enzymes  of 
the  wort,  increases  the  acidity,  precipitates 
coagulable  albuminoids,  hydrolyses  some  con- 
stituents, increases  the  wort  constituents  by 
the  addition  of  the  soluble  portions  of  the  hops, 
sterilises  the  wort,  and  darkens  the  colour, 
probably  due  to  sgration  causing  oxidation. 

The   hydrogen   ion    potential   increases    by 


100 

The  mash  tun  wort  as  it  (lows  from  the  mash 
tun  is  collected  in  a  wort  receiver  or  underbock, 
and  tbenoe  is  conducted  into  the  coppers  where 
it  is  boiled  with  hops. 

These  vessels,  oa  their  name  indicates,  ore 
made  of  copper  (although  iron  vessels  are  also 


Fio.  S. 

boiling  with  1   lb.   hops   per  barrel  from  0   to 
6'S,  and  to  6  if  2j  lbs.  per  barret  are  added. 

Proteid  coagulation  reaches  its  maximum 
after  4  hours  boiling,  about  6  p.c.  of  the  total 
nitrogen  is  thus  precipitated ;  the  great«r  the 
amount   of   hops   the   greater   the   amount   of 


678  BRB1 

coagulation,  but  aa  the  hops  contribute  nitro- 
geoou*  compouiid«,  the  total  amount  of  nitro- 
genous bodies  in  the  wort  is  not  much  affected. 
After  boilins,  the  contonta  of  the  coppers  are 
emptied  into  ttie  hop  back,  s  vessel  fumidied 
with  a  false  bottom  of  perforated  platea  by 
means  of  wlilch  the  hops  are  strained  from  the 
wort.  The  layer  of  hops  acts  as  a  filter,  and 
removes  the  albuminoids  and  other  matter 
precipitated  by  boiling.  The  iiopa  rsmaining 
are  either  extracted  with  hot  water  or  pressed 
dry   in   a   hydivulic   press,    the   spargings   or 


hops  were  lonnerly  used  as  a 
(191S),  owing  to  the  scarcity  and  high  price  of 
feeding  stuff,  are  used  as  cattle  food,  either 
fre«h  from  Uie  brewei?  or  usually  dried  and 
ground  and  incorporated  with  other  materials. 
The  dried  hops  contun  H  p.c.  proteins  and  3i> 


p.c.  assimilahle  carbohydrates  (Baker  and 
Hulton,  J.  Inst.  Brewing,  1917, 465).  The  wort 
ahonid  run  off  from  the  bop-baob  quite  '  bright.' 
It  is  now  allowed  to  eooL  Formerly  only  laige 
sh^ow  vessels  were  used,  but  now  these  vessels 
are  of  varying  depth,  or  are  sometimes  dis- 
pensed with ;  in  any  osae  the  wort  remains  in 
them  only  for  a  short  time.  The  cooling  ia 
completed  by  allowing  the  wort  to  flow  over 
refrigerBtors,  vessels  in  which  a  cnrttnt  of  oold 
water  flows  in  tubes  in  the  reverse  direction  to 
the  wort  which  flows  outside  (he  tubes.  The 
cooling  stage  is  of  considerable  intportaaoei  both 
chemicaUy  and  biologically. 

The  wort,  during  cooling,  throws  down  a 
deposit,  partly  due  to  the  separation  of  calcinm 
oxalate,  some  of  which  forms  a  scale  on  the 
rtly  to  a  separati 
I  gluten  particles,  and 
o  be  a  compound  of  proteid  and 
•  ■    ■  "      ■      iflia.  M). 


during  all  subsequent  stages  of  brewing  and 
storage.  Although  its  total  amount  is  small, 
never  reaching  more  than  1  p.c.  of  the  nitrogen 
compounds,  yet  owing  to  ite  liabihty  to  form 
opalescent  suapenaiona.  it  is  of  considerable 
importance.  Agitetion  whilst  cooling  from 
49^  (120=F.)  te  27*  (80°F.)  is  found  to  cause 
llocculation  of  these  particles. 

During  the  cooling  process,  the  wort  absorbs 
oxygen  from  the  air.  From  experiments  it 
appears  that  from  6  to  7  c.c.  oxygen  may  be 
absorbed  per  litre  of  wort,  the  mtler  figure 
indicating  full  saturation. 

The  wort  also  usually  becomes  infected 
during  cooling.  Until  the  temperature  falls 
below  55°  C.  (130°  F.)  there  can  be  no  infection; 
so  for  this  reason  coolers  are  sometimes  dis- 

Eensed  with,  and  the  worts  run  direct  from 
op  back  to  refrigerator  and  thus  rapidly 
cooled  This  is  eflectoal  in  lednotng  infection, 
but  it  has  been  found  sometimes  to  lead  to 
clarification  trouble,  which  appears  to  be  due  to 


the  separation  of  the  above-mentioned  gluten 
bodies  in  such  a  minute  state  tiiat  th^  wiU  not 
deposit.      In   general   some   kind   of  cooler  is 

used,  either  a  shallow  or  deep  vesaeL 

Infection  on  the  cooler  and  refrigerator 
must  be  initially  due  to  air  infection,  and 
proposals  have  been  made  to  supply  the  rooms 
in  which  these  are  placed  with  sterilised  air. 
In  practice  it  is  found,  in  all  but  exceptional 
oases,  tlkat  the  amount  of  air  infection  ia  very 
small  compared  with  the  amount  of  vessel 
infection.  If  the  coolers  are  made  ol  metal 
there  should  be  little  difficulty  in  keeping  these 
aterilised,  as  the  hot  wort  every  time  it  oovers 
them  should  do  this ;  if  they  are  wood  it  is  found 
that,   however  well   made,   sterilisation   is  im- 

Cible.  Owing  to  its  porous  nature  organiama 
in  the  poree  just  below  the  surface,  and  the 
non-conducting  nature  of  the  wood  preveals 
any  but  the  immediate  surfaoe  layers  rising  to 
the  sterilising  temperature. 

The  nfr^eiatora,   with  the  necessary  pipo 


BREWING. 


679 


oonnections,  are  metal,  and  it  apoeara  at  iiist 
that  there  should  be  no  diffioulty  in  Keeping  these 
sterile,  but  owing  to  orevioes  at  joints,  Ao.,  in 
practioe  complete  sterility  is  impossible  to  attain. 

With  care,  a  harmful  amount  of  infection  can 
be  avoided,  and  air  sterilisation ,  although  it  may  be 
looked  on  as  a  counsel  of  perfection,  rendered  un- 
necessary.  If,  however,  precautions  are  not  taken, 
the  cooled  wort  may  be  very  grossly  infected. 

The  wort  runs  from  the  refrigerator  at  a 
temperature  of  15''-16''  (60'' F.)  or  thereabouts, 
according  to  the  time  of  the  year  and  kind  of  beer, 
into  the  fermenting  vessels.  For  lager  beer,  how- 
ever, the  wort  is  cooled  to  6M°  (40**-45*  F.). 

The  fermentation  vessels  are  made  of  wood, 
metal,  stone,  slate,  concrete,  &c.  Metal  may 
be  considered  the  ideal  material,  as  its  surface 
is  impervious,  and  it  is  easily  sterilised.  Thev 
are  usually  either  circular  or  rectangular  witn 
flat  bottoms ;  circular  vessels  have  no  comers 
in  which  dirt  can  accumulate,  but  rectangular 
vessels  make  more  use  of  the  often  limited  space. 

As  soon  as  the  collection  begins  the  wort  is 

*  pitched,'  I.e.  is  seeded  with  a  yeast  derived 
from  a  nrevious  brewing.  The  number  of  yeast 
cells  aaded  is  very  much  greater  than  the 
number  of  organisms  with  which  the  wort  is 
normally  infected.  The  amount,  however,  must 
be  so  regulated,  according  to  the  nature  of  the 
wort,  that  a  considerable  increase  (5-10  times)  is 
possible.  The  yeast  ^  Saccharomyoes  cenvieia,* 
used  by  brewers,  is  a  '  culture '  yeast,  that  is,  one 
which  has  been  selected  or  possibly  evolved  in  civi- 
lised communities  as  specially  suitable  for  brewing. 

There  are  two  main  varieties,   '  high '   or 

*  top  *  fermentation  yeast,  and  *  low  *  or 
'  bottom  '  fermentation  yeast. 

The  first  is  used  at  a  higher  temperature 
than  the  second;  the  brewery  fermentations 
are  consequently  more  rapid ;  the  yeast  rises  to 
the  top  towards  the  ena  of  the  fermentation, 
whereas,  under  the  conditions  in  which  the  latter 
is  used,  it  falls  to  the  bottom  at  the  end  of  the 
fermentation.  Lager  beer  is  brewed  on  the  low 
fermentation  system  ;  all  other  beers  a^d  stouts 
on  the  high  fermentation  system. 

Ab  worts  usually  become  infected  by  other 
yeasts  (wild  yeasts)  and  bacteria  dunng  the 
coolins  and  subsequent  processes,  the  yeast 
crop  obtained  at  the  termination  of  fermentation 
will  contain  foreign  organisms.  As  this  is  used 
for  seeding  the  succeeding  worts,  it  is  easily 
possible  in  time  for  the  swed  yeast  to  become 
seriously  infected,  even  if  the  initial  wort  infec- 
tion is  kept  down  by  suitable  precautions.  As 
will  be  seen  later,  these  foreign  organisms  may 
lead  to  serious  defects  in  the  final  product. 

In  order  to  surmount  this  difficulty,  Hansen, 
in  1883,  introduced  his  pure  yeast  system  into 
bottom  fermentation  breweries  He  separated 
single  yeast  ceUs  from  the  brewery  yeast,  and 
from  each  of  these  grew  sufficient  to  make  a 
trial  brewing.  The  culture  giving  the  most 
satisfactory  result  was  selected  and  used  in  the 
brewery.  A  pure  pitching  yeast  was  thus 
obtained.  This  has  been  adopted  with  great 
success  in  laser  beer  brewing,  but  breweries 
working  on  the  top  fermentation  system  have 
not  found  the  pure  yeast  thus  prepared  altogether 
satisfactory.  Many  reasons  have  been  given 
for  this.  Although  there  seems  to  be  no  doubt 
that  in  some  breweries,  notably  in  Denmark 


and  America,  top  fermentations  are  carried  out 
successfully  with  a  pure  yeast;  yet  in  many 
other  breweries  in  which  it  has  been  tried,  it 
has  been  abandoned.  It  is  fairly  well  agreed 
that  the  explanation  of  its  non-success  is  that 
a  mixture  of  yeast  is  necessary  in  this  case, 
although  there  is  much  diversity  of  opinion  as 
to  what  this  mixture  should  be  (Claussen,  J. 
Inst.  Brewing,  1004,  308 ;  Van  Laer,  ibid.  1804, 
55 ;  Siau,  ibid.  1906,  118 ;  Schionning,  C.  R. 
Lab.  Carlsbeig,  1908,  138 ;  Morris,  1900,  333). 
Yeast  may  be  freed  from  bacteria  by  treatment 
with  solution  of  definite  acidity  (about  0*1  p.c. 
H^OJ  (Brown,  J.  Inst.  Brewing,  1916,  328). 

Fermentation  by  growing  yeast  cells  is  a 
complicated  process,  in  which  numerous 
chemical  reactions  take  part.  Although  our 
knowledge  of  these  is  far  from  complete,  yet 
many  important  factors  have  been  determined. 
It  is  considered  that  only  the  hexose  sugars 
are  fermentable,  the  cit-saccharides  being  first 
transformed  into  their  constituent  hexoees  by 
ens^mes,  cane  sugar  by  invertase,  maltose  by 
maltase.  The  rate  of  fermentation  of  glucose 
and  levulose  is  independent  of  the  concentoktion, 
except  in  very  strong  or  very  weak  solutions ; 
it  isproportional  to  the  amount  of  yeast 

The  amount  of  yeast  present  in  the  fer- 
menting wort  at  any  time  depends  on  many 
factors.  If  a  small  yeast  seeding  be  introduced 
into  wort,  the  yeast  grows  unrestrictedly  until 
the  concentration  is  sufficient  to  cause  con- 
siderable chemical  changes  in  the  wort ;  the 
yeast  growth  is  then  slowed. 

During  the  period  of  unrestricted  growth  the 
number  of  yeast  cells  increases  logarithmally  with 
the  time  ;  that  is,  x>ver  equal  intervals  of  time 
(generation  time)  the  number  of  cells  double 
themselves.  Brewers'  yeast  growing  unrestrict- 
edly at  20°  C.  has  a  generation  time  of  three 
hours.  Temperature  has  a  great  influence; 
between  the  limits  at  which  yeast  grows  freely, 
5°C.  increase  causes  the  rate  of  growth  to  be 
doubled.  Carbon  dioxide  retards  the  rate; 
saturation  with  this  gas  halves  the  rate  of 
growth.  Alcohol  over  2  p.c.  retards  the  rate 
of  growth,  the  amount  depending  on  the  teni- 
perature  as  well  as  the  concentration.  Air 
(oxygen)  is  necessary  for  yeast  growth.  Brewery 
wort  naturaUy  contains  dissolved  air,  and  oxygen 
combined  with  some  wort  constituent  can  also 
be  used  by  the  yeast  Half-fermented  wort, 
saturated  with  carbon  dioxide  and  prevented 
from  absorbing  oxygen  by  a  covering  of  this 
gas,  is  deficient  in  oxygen  necessary  for  yeast 
growth.  The  amount  required  is  smalL  H.  T. 
Brown  estimates  that  1*7  c.c.  oxygen  is  necessary 
for  the  growth  of  10^*  yeast  cells  (about  ^ 
grams  pressed  yeast).  Yeast  growth  also 
depends  on  the  chemical  composition  of  the 
wort.  There  must  be  present  a  carbohydrate, 
suitable  nitrogenous  substances  such  as  are  pro* 
duced  during  the  germination  of  the  barley  for 
the  purposes  of  the  growing  embryo,  and  phos- 
phates, potcusium,  calcium,  and  magnesium  salts 
(A.  J.  Brown,  Chem.  Soc.  Trans.  1905,  1395 ; 
H.  T.  Brown,  J.  Inst  Brewing,  1909,  169 ;  and 
Annals  of  Botany,  1914,  197  ;  Stem,  Chem.  Soc. 
Trans.  1899,  201 ;  and  1901,  943 ;  Slator,  ibid. 
1906, 128 ;  1908, 217  ;  Biochem.  J.  1913, 197 ;  J. 
O^SuUivan,  Chem.  Soc.  Trans.  1892, 593,  and  926). 
The  changes  which  take  place  during  the 


680 


BREWING. 


fermentation  of  a  brewery  wort  are  briefly  as 
follows:  An  average  seeding  (pitching)  of 
10  million  cells  per  cubic  cent,  will  increase 
up  to  about  100  million  per  c.o.  There  is  a 
period  of  quiescence  before  growth  starts.  It 
then  proceeds  steadily,  but  retarding  influences 
soon  come  into  action  and  continually  slow 
down  the  rate.  The  chief  of  these  is  the  effect 
of  carbon  dioxide  and  the  gradual  failure  of 
the  oxygen  supply.  There  is  plenty  of  yeast 
food  present,  and  the  amount  of  alcohol  is  not 
sufficient  to  have  any  great  influence.  Rapid 
fermentation  is  now  taking  place,  with  evolution 
of  laige  quantities  of  carbon  dioxide  which 
prevents  air  getting  into  the  fermenting  solu- 
tion. It  is  at  this  stage  of  the  fermentation 
that  brewers  who  employ  two  fermentation 
vessels  {see  below)  usually  *  drop  '  or  *  tun/  that 
is,  transfer  the  fermenting  worts  from  the  one 
vessel  to  the  other.  Tlus  causes  the  removal 
of  some  carbon  dioxide,  and  allows  some  air  to 
be  absorbed  by  the  worts,  there  is  a  slight 
renewal  of  yeast  growth  ;  but  the  chief  amount 
of  yeast  increase  has  now  taken  place.  The 
rate  of  fermentation  is  now  mainly  dependent 
on  the  number  of  yeast  cells  and  the  temperature. 

The  influence  of  temperature  is  great ;  the 
following  table  gives  the  grams  dextrose  fer- 
mented |)er  second  by  10^*  yeast  cells  (Burton 
yeast) : — 

Temperature  40°  0.  •  5-05  grams. 
36°  C.  .  405 
30°  C.  .  3-00 
26°  C.  .  208 
20°  C.  .  1-30 
16°C.  .  0-68 
10°  C.  .  0-346 
6°C.     .     0140 

The  temperature  continuously  rises  owing 
to  the  heat  evolved  by  fermentation:  the  heat 
of  fermentation  of  glucose  is  22K.  (Bouffard, 
Compt.  rend.  1896,  367 ;  A.  J.  Brown,  J.  Inst. 
Brewing,  1901,  93),  and  the  brewer  has  to 
control  this  by  suitable  cooling  appliances. 

Glucose,  fructose,  and  cane  sugar  are  fer- 
mented faster  than  maltose ;  maltase  is  not 
so  abundant  in  the  yeast  as  invertase.  Small 
amounts  of  glucose  present  in  half-fermented 
wort  may  very  likely  have  come  from  the 
maltose;  there  are  also  present  in  malt  worts 
transformation  products  of  starch  of  higher 
molecular  weight  than  maltose,  and  there  is 
some  evidence  that  some  of  these  are  fermented. 

The  mechanism  of  alcoholic  fermentation 
is  still  to  be  discovered,  although  some  facts 
have  been  determined.  Buchner  and  his  co- 
workers (1893-98)  proved  that  an  enzyme  capable 
of  fermenting  glucose  could  be  separated  from 
the  living  yeast  cell  by  great  pressure.  Harden 
and  Young  (Proc.  Roy.  Soc.  1908,  299  ;*  1909, 
336  ;  1910,  321)  have  investigated  this  reaction 
and  established  the  equation, 
2CgHi,0,+2P04HR, 

=2CO,^-2C,H,0-i-2H,0+C,H,o04(P04R;^, 
The  hexose  phosphate  may  be  isolated  and  its 
salts  prepared ;  when  hydrolysed  by  acid  it 
decomposes  into  phosphoric  acid  and  fructose ; 
it  is  slowly  hydrolysed  bv  an  enzyme  present 
in  yeast  juice  and  the  resulting  sugar  fermented. 
By  filtering  the  juice  through  gelatine  supported 
by  a  porous  filter  cell.  Harden  and  Young  were 
aole  to  separate  the  juice  into  two  portions. 


tt 


tt 


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tt 


It 


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f> 


either  of  which  was  itself  incapable  of  fermenting 
glucose,  but  which  regained  this  property  when 
reunited.  The  filtrate  containmg  the  co- 
enzyme can  be  boiled  without  losing  its  activity, 
but  the  residue  is  thermolabile.  Harden 
(Bioofaem.  J.  1917,  1104)  found  that  a  mixtuze 
of  potassium  or  ammonium  phosphate  with 
acetaldehyde  or  potassium  pyruvate  can  function 
completely  as  the  co-enzyme.  Instead  of  yeast 
juice  obtained  from  tiie  living  cell  by  pressure ; 
these  reactions  can  be  carried  out  by  Lebedeff's 
dried  yeast  (Compt.  rend.  1911,  49),  or  zymin 
(Albert,  Buchner,  and  Rapp,  Ber.  1902,  2376). 

How  far  this  important  work  bears  on 
brewery  fermentation  it  is  difficult  to  say. 
Fermentation  by  living,  yeast  is  not  influenced 
by  the  addition  of  phosphates,  and  one-half  of 
the  sugar  is  not  fermented  rapidly  and  one-half 
slowly.  It  seems  probable  that  were  are  inter- 
mediate products  between  the  sugar,  and 
alcohol,  and  carbon  dioxide,  and  although  much 
work  has  been  done,  the  theories  so  far  advanced 
do  not  carry  conviction. 

The  chief  products  of  alcoholic  fermentation 
are  alcohol  and  carbon  dioxide,  the  amount  of 
alcohol  produced  according  to  the  simple 
equation  of  Gay-Lussac  is  61*1  p.c.  from  a 
mono-saccharide,  and  64*1  p.c.  from  a  di- 
saccharide.  The  sugars  of  malt  worts  consist 
of  about  83  p.c.  maltose  and  17  p.c.  of  sugars 
pre-ezistent  in  the  malt  which  are  mainly  cane 
sugar,  glucose  and  fructose.  H.  T.  Srown 
(J.  Inst.  Brewing,  1914,  693)  found  there  was 
produced  at  the  commencement  of  the  fermenta- 
tion 66  p.c.  of  alcohol  (0-1*6  p.c.  alcohol)  falling 
to  62*6  p.c.  (1*6-3-0  p.c.  alcohol)  and  61*6  p.c. 
(3  p.c.  alcohol  onwards). 

Besides  alcohol  and  carbon  dioxide  there  are 
produced  by  the  fermentation,  glycerol,  anodnic 
acid  (Ehrlich,  Bied.  Zentr.  1908, 197),  and  higher 
alcohols  (Ehrlich,  Ber.  1907,  1027;  Ashdown 
and  Hewitt,  Chem.  Soc.  Trans.  1910,  1636). 

A  considerable  reduction  of  the  nitrogen  con- 
tent of  the  wort  takes  place  during  fermentation. 
This  varies  from  20  to  40  p.c.  of  the  total  wort 
nitrogen,  according  to  working  conditions.  By 
adding  more  sugar  and  again  fermenting  it  is 
j>ossible  to  remove  nearly  60  p.c.,  but  a  furtiier 
fermentation  will  only  remove  a  few  per  oent. 
more  (H.  T.  Brown,  J.  Inst  Brewing,  1907,  423). 

The  hydroffen-ion  potential  increases  during 
fermentation  from  6  to  4  (Luers,  Zeits.  Ges. 
Brau.  1914,  79). 

The  amount  of  acid  produced  during  fer- 
mentation is  dependent  on  the  acidity  of  the 
wort ;  within  limits,  the  more  alkaline  the  wort 
the  more  acidity  is  produced;  thus  the  yeast 
tends  to  produce  a  certain  favourable  con- 
centration of  acid  (Windiach  and  Koolman. 
Woch.  Brau.  1914,  226;  Moo^ang,  Brass,  et 
Malt,  1913,  177  and  297  ;  1914,  72).  » 

If  the  wort  were  left  undisturbed  in  the 
fermentation  vessel,  the  first  cauliflower-like 
foam  which  forms  in  a  few  hours,  would  give 
place  about  two  hours  later  to  a  larger  rocky 
and  glistening  foam,  and  this  in  two  or  three 
days  in  turn  to  a  veasty  head.  ThxDughout  the 
greater  portion  of  the  fermentation,  the  yeast, 
which  nas  a  higher  specific  gravity  than  the 
wort,  is  kept  in  suspension  by  we  rising  bubbles 
of  carbon  dioxide,  but  towards  the  end  it 
flocculates  and  entangles  the  rising  babbles  of 


C0|,  ths  Bpongy  masi  thus  fonu«d  rUee  U>  the 
Burlace,  forming  tbe  yetuty  head.  If,  however, 
not  quickly  removed,  the  gas  'a  lost  and  the 
feast  Jails  to  the  bottom  of  the  liquid.  If 
.  yiast  be  not  removed  as  soon  as  it  rises,  but  be 
allowed  to  fall  through  the  fermented  wort 
(or  beer  as  it  now  is),  it  communicates  to  this  a 
yessty  Barour  and  spoils  it.  In  bottom  fer- 
menl*tion  the  yeast  also  flocculates  towards 
tbe  end  of  the  fermentatioQ,  which  owing  to 
the  low  temperature  proceeds  mach  slower,  and 
the  yeast  faUs  to  the  bottom  of  the  veeseL 

The    top    fermentation    brewer,    therefore, 
■ulopts   some   system   of   '  cleansing,'    that   is. 
some  mode  of  removal  of  the  yeast  aa  sooa  as 
it  rise*  to  the  aurfnce.    There  are  two  typiciil 
systems   ia  use,  i.t.   'the   skimming 
system,'   in   which  the   fermentation 
throughout  proceeds  in  lai^e  vessels, 
ana  the  yeast  as  it  rises  is  skimmed  off ; 
and  the  '  cleansing  system,'  in  which 
the  latter  portion  of  the  fermentation  | 
is  conducted  in  casks,  and  the  yeast  al  - 
lowed  to  work  out  of  the  bung  hole,  the 
cask  being  kept  su the iently  full  by  top- 
pings of  bright  beer.     There  are  many  < 
moaJGcHtions  of  these  two  Bystems. 

The  skimming  syslcni  ia  the  one 
chiefly  employed  in  the  United  King- 
dom, but  instead  of  skimming  off  the 
yeast  by  hand,  an  apparatus  termed  a, 
yeast  parachute  ia  fined  in  the  fer- 
menting vessel ;  this  has  a  funnel  shape 
with  the  narrow  end  in  communication 
witha  pipe  passing  through  the  bottom 
of  the  vessel  (Fias.  9  and  10). 

The  height  of  the  aperture  is  con. 
trolled  by  auit^ble  gearing,  so  that  the 
yeast  as  it  rises  flows  over  the  edge 
through  the  pipe  into  a  vessel  below. 
In  very  large  ve«sels  this  is  assisted  by 
tbe  movement  of  the  board.  Attem- 
perators,  or  coils  through  which  cold 
water  can  be  circulate,  are  usually 
fitted  BO  that  the  temperature  of  the 
fermenting  wort  may  be  controlled. 

It  is  usual  to  commence  the  fermen- 
tation in  a  plain  vessel  and  'drop  '  the 
wort  when  about  half  fermented  into 
the  skimming  vessel.  Tbe  effect  of 
this  has  been  described  above. 

An  elaboration  of  the  simple  cleans- 
ing   in   casks,    is   the   Burton    Union 
S;^lem.      This  ia  so  totally  different 
fnim  the  skimming  system  that  all  others  may  be 
■aid  to  be  intermediate,  and  it  is  not  proposed 
to  describe  them. 

The  beer  to  be  worked  or  '  cleansed '  by  the 
Burton  System,  is  collected  and  pitched  (seeded) 
in  vessels  of  about  60  barrels  capacity,  and  the 
fermentation  allowed  to  proceed  until  the  at- 
tenuation of  the  fermenting  wort  is  about  two- 
thirds  of  the  original  gravity,  and  the  tempera- 
t«reha8riBentol8''-2r(05M0''F.).  Thewortia 
Itien  '  tunned,'  that  is.  tnmsferred  to  the  onions. 

A  set  of  Burton  Unions  (Fig.  1 1 )  consists  of 
two  TOWS  of  casks,  each  cask  holding  about 
160  gallona,  mount^  horizontally  on  trunnions 
oa  aframe  work.  Above  the  casks  is  fixed 
»  long  shaUow  trough  (the  yeast  trough),  not 
quite  one-half  the  width  of  the  double  row  of 
cask*,  and  at  one  end  of  the  union  set  Is  a  smaller 


cross  trough,  tbe  bottom  of  which  Is  a  few  inche« 
lower  than  the  yeast  trough,  but  high  enough  to 
command  the  casks.  Each  cask  is  furnished  with 
a  swan  neck  which  fits  into  a  socket  in  the  highest 
portion  of  the  cask,  and  projects  just  over  the 
edge  of  the  yeoat  trough,  and  with  a  tap  at  the 
lowest  portion  of  the  cask,  the  nozzle  of  which 
projects  a  couple  of  inches  into  the  cask.  The 
tap  has  a  screw  thread,  so  that  tho  inlet  can  be 
lowered  or  the  tap  entirely  removed,  leaving  the 
cask  opening  tree.  The  casks  are  also  provided 
with  attemperatois  through  which  cold  water 
may  be  passed  for  oontrolling  the  temperature 
of  ^rmentation.  The  yeast  trough  is  ahK>  pro- 
vided with  attemperators  which  are  counter- 
poised in  order  that  they  may  be  easily  lifted  up. 


From  Stiitt  and  £uw'>  £rcu<iv  {Cliarle4  OtiSiJi  i  Co.,  Ltd.). 

At  one  end  the  yeast  trough  communicates 
with  the  cross  trough  or  feeder  by  outlets  at 
various  levels,  any  one  or  all  of  which  may  be 
closed  as  required.  The  feeder  communicates 
with  tbe  casks  bj  a  long  side  pipe,  the  feeder 
inlet  of  this  having  a  screw  cup  which  may  be 
raised  or  lowered  in  order  to  prevent  sediment 
from  the  feeder  getting  into  the  cask,  or  the 
cup  may  be  removed  entirely.  This  pipe  ia 
fumLsbed  with  a  main  tap  to  control  the  flow 
into  the  cask  (the  feed),  and  each  cask  with  a 
8epaiat«  tap,  so  that  any  one  may  be  dis- 
connected. There  are  abo  outlets  from  the 
yeast  trough  and  feeder  for  removing  yeast 
(barm). 

The  casks,  top  trough,  and  feeder  are  filled 
with  tiie  fermentii^  wort,  but  none  of  the 
vessels  ia  full  of  liquid,  as  there  is  a  considerable 


amaunt  of  foam.  The  fermenting  wort  in 
the  cask  is  under  the  prearare  of  Uie  head  of 
liquor  in  the  feeder,  and  oonaequentlj  bo  long 
aa  carbon  dioxide  is  being  prodnoed  in  quantity, 
a  foam  is  forced  vp  the  ewiui  neck  into  the  yeast 
trough.  This  settles  to  lome  extent,  uid 
funushea  more  head  of  liquor  in  the  feeder,  and 
so  the  circulation  cootinuet.  With  a  wort  of 
fairly  high  gravity  the  whole  bulk  of  the  brewing 
would  circulate  saveral  times.  When  the 
fermeatation  nears  the  end,  the  character  of 
the  foam  changes,  owing  to  the  rise  of  the  yeaat. 
It  becomes  yeaa^,  and  in  the  yeast  troush 
sepuftte«,  a  part  of  the  yeast  settlit^  to  tBe 
bottom,  and  a  port  foRning  a  thick  skm  on  the 
surface ;  in  between  these  two  layers  is  a 
stratiuQ  of  fairly  bright  beer.  This  bnght  beer 
only  is  allowed  to  return  through  the  feeder. 


t  beer,   and  the 


where  a,  little  r 
the  casks,  si 

filled  with  more  or  less  bright  b 
greater  part  of  the  yeast  remains  ii 
troogk.  The  beer  is  allowed  sjiother  day  or*Bo 
in  the  cask  to  settle,  and  it  is  then  run  from  the 
bottom  tap  by  a  trough  into  a  veaKl  below  (the 
nuiking  vessel),  the  tap  projecting  into  the  cask 
suffioiently  to  hold  back  the  oediment  (grounds). 
The  fermentation  is  so  oontrolled  that  *t 
the  racking  stage  there  always  remaiuB  some 
fermentable  sugar ;  and  aa  whatever  mode  of 
yeast  removal  is  adopted,  it  is  impoaiible  lo 
Kmove  all,  some  remains  in  suspension.  In 
this  state  the  beer  is  iscked,  i.e.  transferred 
from  the  brewery  vessels  to  the  carriage  cuks. 
It  is  convenient  and  usnaJ  to  employ  an  inter- 
mediate vessel   (racking  vessel).    This  ia  pro- 


vided with  taps,  usually  of  special  design,  so  that 
the  casks  are  filled  without  loss  doe  to  overflow. 

Lager  beer  is  not  racked  into  the  carriage 
casks  immediately  at  the  conclusion  of  the 
brewery  fermentation,  but  kept  in  cold  stores 
for  2-4  months  in  lager  casks  (huge  vessels 
holding  100-3000  gallons).  During  storage  a 
slow  afler-fermentatioa  taJies  place,  and  during 
the  lost  period  the  carbon  dioxide  is  allowed  *~ 
accumulate  up  to  a  pressure  of  2-4  lbs.  per 
square  inch.  The  beer  clarifies,  and  is  racked 
into  casks  or  bottles  for  immediate  consumptit 
Stout  is  also  often  stored  in  vats  betwevn  the  end 
of  the  brewery  fermentation  and  rocking  stage. 

Several  additions  are  commonly  made  to  the 
beerwhen  racked  direct  from  the  brewery  vessels, 
flops  are  usually  added,  from  2  oz.  per  barrel 

Bi  to  1  lb.  per  barrel  for  strong  or  slock  ales. 
ops  of  fine  flavour  are  chosen  for  this  purpose, 
sa  the  hop  oil  which  is  lost  when  boiled  in  the 
copper  is  here  retained  and  odds  to  the  beer 
aroma.  Pieeervative  substances  of  the  hop  dis- 
solve in  the  beer,  and  the  bracts,  tc,  mecliani- 
cally  assist  clarification.  If  ops  contain  diastase, 
which,  acting  on  some  carbohydrate  constituents 


of  tlie   beer,   may  produce   fermentable  sugar, 

and  thus  give  life  or  '  condition  '  to  the  beer 

[Brown  andHorria,  J.  Inst.  Brewing,  1893,  94). 

Sugar  solutions  ore  often  added  at  racking, 

«  shortly  afterwords.  This  makes  '  condition  ' 
rtain. 
An  antieeptic,  usually  a  sulphite,  is  com' 
monly  added.  Beer  naturally  contains  some 
SO,,  this  is  introduced  during  the  kilning  of 
tlie  malt  and  drying  of  the  hope ;  aa  much  aa 
26  milligrams  per  htre  have  been  found,  but  moat 
beers  contain  only  a  few  milligrams  per  lilnt 
(Borm,  Ann.  des  Falsifications,  1909,  44);  it  ia 
also  an  ancient  custom  to  sterilise  the  interior 
of  the  vessels  with  sulphur  dioxide.  Wbtti 
sulphurous  acid  (or  sulphites)  a  added  to  beer, 
a  portion  is  soon  oxidised,  the  remainder  com- 
bines with  the  sugars  or  other  oldehydio  or 
ketonio  compounds,  and  in  this  state  is  much 
less  toxic  than  tba  free  acid.  Wiley  (U.S.A. 
Dept.  of  Agriculture,  ]H01)  and  Kerp  (Arb.  aos 
der  Kaiserlicha  Oesundheitsampte,  1904,  21, 
IG6-284  ;  1907,  26,  231)  have  made  exhaustive 
investigations  on  its  toiio  action.  The  modente 
use  of  this  antiseptic  is  generally   permitted. 


BREWING. 


683 


The  Beer  Materials  Committee,  1899,  reported 
that  it  would  be  unwise  to  prohibit  preservatives 
in  beer.  An  International  Food  Congress, 
Paris,  1909,  recommended  that  it  be  alloweid  up 
to  85  milligrams  per  litre.  Such  an  amount  has 
but  a  slight  retarding  effect  on  yeast  growth  and 
fermentation,  and  less  is  sufficient  to  prevent  the 
growth  of  some  common  beer  bacteria,  such 
as  8acch(trobaciUu8  Pastoriantu,  which  in  the 
absence  of  sulphite  may  do  much  damage. 

An  important  by-product  of  the  fermentation 
is  the  yeast  or  barm ;  not  so  long  ago  this  was 
a  waste  product  difficult  to  get  rid  of,  and  only 
used  as  a  manure.  Now  it  is  a  valuable  food, 
and  otherwise  usefuL 

The  barm,  as  separated  from  the  beer,  is  a 
thick  creamy  mass,  and  is  usually  pressed  in  a 
filter  press,  the  bright  beer  being  returned  to 
the  brewery  vessels.  The  filter  caike  is  a  cream- 
coloured  powdery  mass  containing  about  75 
p.c.  water.  If  allowed  to  stand,  it  autolyses 
and  liquefies  in  a  few  days  by  the  action  of  the 
digestive  enzymes  it  contains;  the  most 
satisfactoiy  way  to  preserve  it,  is  to  dry  it  on 
steam-heated  rollers.  The  pressed  yeast  is 
heated,  when  it  liquefies,  and  then  flows  in  a 
thin  film  on  to  the  hot  revolving  roller,  a  current 
of  hot  air  drives  away  the  steam,  and  in  about 
three-fourths  revolution  the  film  is  dry  and  is 
scraped  off  by  a  fixed  knife.  Such  dried  yeast 
is  an  excellent  food  for  cattle,  but  possesses  a 
rather  bitter  flavour;  this  may  be  to  some 
extent  removed  by  washiug  the  pressed  yeast 
before  drying  with  ammonium  or  scdium 
carbonate.  It  contains  5-10  p.c.  water,  60-60 
p.c.  albumenoids,  25-35  p.c.  carbohydrates,  up 
to  4  p.c  fat,  and  about  10  p.c.  ash,  of  whicn 
about  one-half  is  phosphoric  acid.  By  some 
refinements  in  the  preparation  a  product  is 
obtained  resembling  meat  extract,  and  largely 
used  in  the  preparation  of  dried  soups  (Petit, 
Brass,  et  Malt,  1917,  257).  It  has  been  shown 
to  contain  water  soluble  accessory  growth-pro> 
moting  substance ;  this  is  not  present  in  meat 
extracts  (Drummond,  Biochem.  J.  1917,  255). 

From  brewers'  yeast  is  prepared  nucleic 
acid  (Clarke  and  Schiyver,  Biochem.  J.  1917, 
319) ;  this,  on  hydrolysis,  yields  phosphoric  acid, 
adenine,  guanine,  uracil,  cytosine,  and  <i-ribose. 
Yeast  nucleic  acid  or  its  sodium  salt  is  injected 
subcutaneously  with  the  object  of  increasing 
the  number  of  leucocytes.  Silver  preparations 
(nucleosil  and  nargol)  are  used  in  inflammatory 
diseases,  and  iron  salts  (fer  ascolic  and  nucleogen) 
in  cases  of  antemia.  Thyminic  acid  (solurol)  is 
also  prepared  from  yeast  and  used  for  rheuma- 
tism and  gout. 

Brewers'  veast  has  been  used  from  time 
immemorial  tor  bread-making.  Within  recent 
years  its  use  has  been  largely  supplanted  by 
*  bakers'  yeast,'  a  different  variety  of  Saccha- 
romyceSf  which  works  at  a  higher  temperature 
and  does  not  undergo  autolysis  so  quickly. 
This  yeast,  although  not  suitable  for  brewers 
use,  is  employed  by  distillers.  Breweiy  yeast  is, 
however,  improved  for  bakers'  use  by  passing 
through  a  fermentation  in  a  not-hopped  (dis- 
tillers)' wort  (Baker,  J.  Soc  Chem.  Ind-  1917, 
836).  Yeast  contains  glycogen,  as  much  as 
40  p.a  has  been  found ;  when  used  in  fermenta- 
tion estimations  yeast  must  be  freed  from 
glycogen  by  exposing  it  in  thin  layers  to  the 


air,  otherwise  there  will  be  a  considerable 
correction  to  be  applied  for  the  auto-fermenta- 
tion of  the  glycogen  (Henneberg,  W.  f.  Brau. 
1902,  781 ;  and  Zeit.  Spiritusind,  1910,  242). 
It  mi^  be  easily  prepared  from  yeast  (Harden 
and  Young,  Chem.  Soc.  Trans.  1912,  1928),  and 
at  the  same  time  another  carbohydrate,  the 
yeast  gum  of  Salkowski  (Ber.  1904,  497  and  925) 
is  obtained.  This  latter  yields  mannose  on  hy- 
drolysis. Yeast  contains  about  2  p.c.  lecithine  (at- 
palmitoncholine-lecithine).  Yeast  has  a  strong 
reducing  power,  it  reduces  sulphur  and  also  sul- 
phites under  certain  conditions  to  sulphuretted 
hydrogen,  and  under  starvation  conditions  can 
even  reduce  sulphates  (Stem,  Chem.  Soc.  Trans. 
1899,  201 ;  and  J.  Inst.  Brewing,  1899,  399). 

The  beer  racked  into  the  carriage  casks  is 
*  shived  down.'     The  residual  sugar  and  yeast 
react,  and  the  carbon  dioxide  produced  by  fermen- 
tation super-saturates  the  beer,  and  it  is  now 
ready  for  sale.     If  left  undisturbed  for  a  few 
weeks  the  beer  will  normally  fall  bright.     This 
is  not  quick  enough  for  ordinary  purposes,  so  it 
is  usual  to  add   '  fining.'    Fining  is  prepared 
from  isinglass,  the  swimming  bladder  oi  various 
fishes,  i.e.  Acipenser  (sturgeon)  giving  Beluga 
leaf,  Siberian  purse,  and  other  Russian  isin- 
fflass ;     Polynemide     giving     Bombay,    East 
Indian,  and  Penang  isingliws;    Siluride  (cat- 
fishee)  giving   BrazU  lump;    and  some   well- 
known  food  fishes  as  cod,  whiting,  haddock, 
and    hake    giving    inferior    kinds    of   isinglass 
(Bridge,   J.    Inst.    Browing,    1905,   508).    Sole 
skin  is  also  used.    To  prepare  fining,  isinglass 
is  soaked  in  water  acidified  with  acetic,  tartaric, 
or  sulphurous  acid,  or  a  mixture  of  these ;    it 
swells  up,  and  more  water  is  added  from  time 
to  time,  until  the  isinglass  is  thoroughly  *  cut ' 
and  a  viscous  liquid  is  obtained,  from  which 
the  undissolved  skin  is  removed  by  wire  sieves. 
About  3  lbs.  of  isinglass  makes  a  barrel  of  fining. 
From  I  pint  to  1  quart  added  to  a  barrel  causes 
a  coagulation  in  which  both  fining  and  the 
suspended  matter  of  the  beer  take  part  and 
which  soon  settles  out,  leaving  the  beer  bright. 
If  the  cask  is  vented  and  carbon  dioxide  is 
coming  off  freely,  the  coagulum  \a  entansled  bv 
the  rising  bubbles  of  gas  and  expelled  urough 
the  vent  hole.    Fining  will  not  remove  actively 
fermenting  yeast  or  iMicteria.    It  is  known  that 
beer  colloids  carry  an  electric  chaige  and  move  to 
the  cathode  (Emslander  and  Freundlich,  Zeitsch. 
physikaL  Chem.  1904,  317),  and  a  simple  ex- 
planation of  the  action  of  fining  appears  to  be 
that  the  fining  colloid  carries  an  opposite  charge, 
and  hence,  when  mixed,  the  two  coagulate. 

Isioglass  dissolves  in  hot  water,  and  a  solu- 
tion of  gelatine  is  obtained,  which  however  has 
no  fining  action  on  beer. 

The  cask  of  bright  beer  is  now  ready  for 
consumption.  Cask  beer  kept  '  on  tap '  more 
than  a  few  days  deteriorates  owing  to  the  loss 
of  carbon  dioxide  and  aeration.  Bottled  beer  is 
free  from  this  risk  of  deterioration  and  has 
advantages  of  convenience ;  hence  an  increasing 
demand  has  arisen  for  it. 

If  bright  beer  be  bottled,  corked,  and  placed 
on  one  side  for  a  few  weeks,  it  will  usually  be 
found  that  a  growth  of  yeast  has  taken  place 
with  fermentation  and  consequent  production 
of  condition  in  the  beer.  The  yeast  easily 
settles  out,  and  there  ia  usually  also  a  deposit 


684 


BREWING. 


of  glutin  bodies.  This  yeast  will,  as  a  rule,  not 
be  the  yeast  whioh  has  produced  the  brewery 
fermentation,  and  which  nas  also  produced  the 
'  condition '  which  follows  immediately  on 
racking,  but  a  wild  (secondary)  yeast  possessing 
quite  different  properties,  and  which  has 
fortuitously  obtamed  access  to  the  beer.  The 
matter  fermented  corresponds  with  the  com- 
position of  a  mixture  of  dextrin  and  maltose 
(Morris,  J.  Inst.  Brewing,  1895,  125).  This 
fermentation  would,  of  course,  also  take  place 
if  the  beer  had  remained  in  cask,  and  the  beer 
would  have  become  turbid  from  the  growth  of 
the  wild  yeast ;  but  when  growth  and  fermentation 
were  completed, '  the  yeast  would  have  settled 
out,  leaving  the  beer  again  bright,  but  with  an 
altered  flavour.  Only  beers  brewed  with  good 
material  and  a  sufficiency  of  hop  remain  stable 
for  the  length  of  time  necessary  for  the  secondary 
fermentation  and  subsequent  clarification ;  inferior 
and  lightly  hopped  beers  fall  a  prey  to  bacteria. 

The  best  brands  of  bottled  ale  thus  pro- 
duced possess  a  character  and  piquancy  which 
is  definite  and  much  in  demand.  Owing  to 
the  difficulty  of  always  ensuring  the  correct 
amount  of  fermentable  matter  and  secondary 
yeasts,  and  the  preparation  of  a  beer  of  sufficient 
stability,,  other  methods  of  preparing  bottled 
ale  have  been  devised. 

The  most  successful  is  to  rack  the  beer  into 
strong  casks  or  metal  tanks  and  add  sufficient 
sugar,  which,  when  fermented,  will  produce  a 
considerable  pressure  of  carbon  dioxide.  This 
having  taken  place,  the  casks  containing  the  beer 
under  pressure  are  placed  in  a  cold  store  (if  the 
beer  has  been  conditioned  in  tank,  the  beer  is 
forced  by  air  pressure  into  a  similar  tank  in 
cold  store)  ana  kept  at  a  temperature  of  —2^ 
(29®  F.)  for  a  week  or  more.  The  beer,  when 
cooled,  should  still  be  super-saturated  with  carbon 
dioxide.  The  cooling  causes  a  precipitation, 
and  in  time  the  beer  would  fall  bright.  Tliis 
would,  however,  take  so  long  that  it  is  usual  to 
filter  the  beer  through  cellulose  pulp  made  up 
in  a  filter  press.  The  beer  issues  from  this 
brilliant,  ana  passes  to  the  bottle-filling  machine  ; 
in  this  the  pressure  is  maintained  so  that  no 
carbon  dioxide  is  evolved,  which  would  cause 
foaming,  and  render  th^  regular  filling  of  the 
bottles  impossible.  The  full  bottles  are  removed 
from  the  machine  and  quickly  corked.  The 
beer  is  ready  for  immediate  consumption,  and 
when  raised  to  room  temperature  pours  out  with 
considerable  sparkle,  ana  in  this  way  resembles 
what  may  be  termed  naturally  conditioned  beer. 
It  has  the  advantage  of  being  ffee  from  sediment, 
but  as  the  beer  is  not  sterile,  this  only  continues 
for  a  few  weeks,  after  which  a  sediment  forms. 
A  considerable  loss  of  colloids  takes  place 
during  chilling  and  filtering,  and  this  renders  the 
beer  inferior  in  flavour  to  beer  not  thus  treated. 

It  is  not  usual  to  pasteurise  beer  brewed  in 
this  country ;  it  keeps  sufficiently  well  for 
ordinary  use,  which  varies  from  a  few  weeks  to 
a  few  months ;  strong  ale,  which  is  often  kept 
for  a  year  or  more,  keeps  quite  well  for  this 
time  owing  to  its  high  alcohol  content  and  hop 
rate ;  and  export  ale  wiU  remain  stable  for 
years,  being  brewed  from  fine  malt  and  large 
proportion  of  hops.  With  lager  beer,  however, 
the  contrary  is  the  case  ;  if  required  for  export 
this  must  be  pasteurised,  usually  at  a  tempera- 


ture of  5o*'-00'»  (130°-140*  F.),  and  is  often  so 
treated  for  home  consumption  as  it  does  not  keep 
more  than  3-6  weeks  at  ordinary  temperatures. 

The  chief  beer  brewing  countries  aie  the 
United  Kingdom,  the  Unit^  States  of  America, 
Germany,  Austria,  Belgium,  and  DenmariL. 
In  each  country  the  methods,  and  consequently 
the  products,  differ.  The  United  Kuigdom 
brewers  employ  mainly  the  high  fermentation 
system,  although  a  little  lafer  is  also  produced. 
The  beerp  are  mild,  bitter,  and  stout  (porter). 
The  mild  ale  differs  from  the  bitter  in  being 
brewed  with  less  hop,  1  lb.  against  2  lb.  per 
barrel  for  a  wort  of  sp.gr.  1060,  and  with  a  higher 
dried  malt  giving  a  sweeter  and  darker  beer. 

Stouts  and  porters  are  prepared  with  an 
intermediate  quantity  of  hops  and  roasted  malt 
to  give  the  black  colour  and  flavour. 

Pale  ale  is  a  bitter  beer  prepared  from  a  wort 
of  sp.gr.  1060  and  about  3  lbs.  hops  per  barrel 
Strong  and  export  ales  are  highly  hopped,  the 
wort  for  the  former  is  usually  of  a  sp.gr.  1 100, 
but  occasionally  beer  from  worts  sp.gr.  1125 
has  been  brewed. 

The  average  original  gravity  was  1052  in 
1914,  since  then,  special  war  restrictions  have 
reduced  this  to  1030  (1918). 

The  average  amount  of  hop  per  barrel  used 
in  1915  was  If  lbs. 

The  beer  duty  is  levied  on  the  specific  gravity 
of  the  worts. 

German  and  Austrian  brewers  employ  almost 
exclusively  the  low  fermentation  system.  Bark 
been  are  brewed  from  well-grown  high  dried  malts, 
and  light  beer  from  less  grown  low  dried  malta. 

In  pre-war  days  very  little  malt  substitute 
was  used  in  Germany.  Berlin  white  beer  is 
brewed  from  wheat  and  barley  malt.  The 
gravity  of  German  beers  did  not  materially 
differ  from  those  of  the  beers  of  this  country, 
although  the  average  gravity  is  lower  owing  to 
the  non-production  of  strong  ales.  The  average 
gravity  of  Austrian  beers  is  a  little  more  than 
that  of  German  beers.  The  war  has  caused  a 
considerable  reduction,  beers  being  now  brewed 
of  an  original  gravity  of  1012-1036.  The  beer 
duty  is  levied  on  the  material 

United  States  brewers  employed  both  high 
and  low  fermentation  systems,  tiiat  is,  brewed 
*  ale '  and  *  beer,'  as  the  products  of  these  two 
systems  were  there  called.  The  tendency  was, 
however,  for  beer  (lager)  to  be  the  chief  products 
Rice  andmaize  preparations  were  used  extensively 
as  malt  substitutes,  and  the  malt  was  prepared 
from  a  barley  of  higher  nitrogen  content  than 
the  European  brewers  would  care  to  use.  The 
duty  was  levied  on  the  beer  produced. 

Belgium  brewed  chiefly  top-fermentation 
beer,  but  imported  considerable  quantities  of 
all  varieties  from  the  United  Kingdom  and 
Germany.  Lambic,  Faro,  and  Mars  are  spon- 
taneously fermented  been  prepared  from  wlieat 
and  barley  malt,  and  may  take  as  long  as  three 
yean  to  prepare.  They  have  a  high  acidity. 
Lambic  is  prepared  from  a  wort  sp.gr.  1066, 
Mare  1050®,  and  Faro  a  mixture  of  the  otiier  two. 

In  France  beer  is  chiefly  brewed  in  the 
northern  part  and  mostly  by  top-fermentation. 

Holland  brews  chiefly  top-fermentation  beer 
of  rather  poor  quality,  but  the  brewing  of  lager 
is  increasing. 

Denmanc  has  a  highly  developed  brewing 


BREWING. 


686 


industry.  Both  top  and  bottom  fermentation 
been  of  average  nayity  are  produced.  The 
duty  is  levied  on  the  beer,  but  that  containing 
less  than  2*26  p.o.  alcohol  is  duty  free. 

Sweden  produces  half  its  beer  from  a  wort 


sp.gr.  less  than  1024,  and  this  is  free  from  duty  ; 
the  other  half  being  law  fermentation  beer  of  the 
UBiial  lager  type. 

The  following  table  gives  the  average  per- 
centage composition  of  the  chief  tyx>es  of  beers : — 


Original 
wort 


Pale  ale  • 
Strong  ale  . 
Extra  stout 
Mild  ale     . 


tf 


Light  bitter  ale  • 

Munich  lager 

(dark) 

Vienna  lager 

Pilsener     • 

American  beers 
(lager)  all  malt. 

American  beers, 
40  p.c.  com, 
60   p.c.  malt  . 

American  ales     . 

Berlin  white  beer 


16-4 
24-2 
18-0 
14-0 
110 
11-0 

12-6-160 
10-14 
11-12 

12-14 


111-12-6 
16-7 
9-12 


Unfer- 
luented 

1 
Alcohol 

Acidity  as 
lactic 

Ash 

Nitrogen 

Phosphoric 
acid 

residue 

1 
1 

acid 

5-3 

5-3 

01 

0-36 

0O8-0-09 

0O6-0-06 

11-2 

6-9 

0-3 

U-65 

0-12 

010 

72 

6-7 

0-2-0-6 

0-33 

011-0-14 

0-16 

60 

4-6 

0O9 

0-3 

008 

0O6 

4-4 

3-5 

0-09 

0-3 

0O44 

0O38 

3-7 

3-9 

0-08 

0-22 

0O44 

0O40 

6-6-7 -2 

3<M1 

0-1 

0-17-0-27 

0O8-O-11 

0O66-O-102 

4-5-6-5 

2-9-3-9 

0-16 

— 

4-5^-0 

3-3-3-7 

01 

0-185 

0O62 

0057 

6^ 

3-4 

01-0-2 

0-20-0-36 

0O8-016 

0O7-013 

6-5-6-6 

31-3-3 

01-0-2 

0166-0-219 

006-008 

0O55-0-064 

6-2 

5  6 

0-2 

0O73 

0O61 

4-6-5 

0-9-3-6 
(av.  2-75) 

0-4 

014 

0O46 

0O30 

Analysis  of  Brewing  Materials  and  Beers. — 
Water  is  analysed  by  methods  in  common  use. 

M(Ut  analysis  is  laigely  empirical  Official 
methods  have  been  laid  down  by  the  Institute  of 
Brewing  (Journal,  1906,  1 ;  and  1910,  629),  by 
Ck>ntinental  Brewing  Stations  (J.  Inst.  Brewing, 
1903,  694 ;  Zeitsch.  ges.  Brauw.  1914,  372  and 
384).    The  determinations  usually  made  are : — 

Moisture, — As  malt  oxidises  and  otherwise 
decomposes  when  heated,  a  definite  time  and 
temperature  is  prescribed  for  drying. 

Extract  obtained  on  mashing.  As  this  also 
varies  with  the  conditions,  the  official  method 
must  be  used  to  obtain  comparable  results. 
It  ia  customary  to  express  the  result  of  extract 
determination  as  the  specific  gravity  which  would 
be  obtained  if  1  quarter  (336  lbs.)  of  malt  yielded 
one  barrel  (36  gallons)  wort.  The  specific 
gravity  is  expr^sed  in  'brewers  pounds.' 
This  method  of  expressing  the  specific  gravity 
is  arrived  at  by  taking  the  weight  of  one  barrel 
water  (360  lbs.)  as  unity,  and  the  'pounds' 
gravity  is  the  figure  obtained  by  deductiiu; 
360  from  the  specific  gravity  thus  expressed. 
That  iB,  1  lb.  grayity=g=lO028 ;  or  3*60  lbs. 

gravity =^^=10 10.  Degrees  of  specific 
gravity  {i.e.  the  excess  over  1000)  can  be  con- 
verted into  *  brewers  pounds '  by  multiplying 
by  0*36.  Continental  brewers  express  the 
extract  as  percentage.  To  obtain  the  quantity 
of  matter  in  solution  from  the  specific  gravity, 
the  saocharometer  of  Balling  ia  largely  used ; 
this  is  graduated  according  to  the  following 
empirical  scale : — 

Degrees  Balling=Bp.  gr.  IXegrees  BaIIing=Sp.  gr. 

1  1O040  6             1O240 

2  1O080  7            10281 

3  1O120  8            10322 

4  10160  9             10363 
6            1O200  10            1-0404 


Degrees  Balllng= Sp.  gr.  Degrees  Balling  -iSp.gr. 

11  .10446  16             10614 

12  10488  16            10657 

13  1O630  17            1O700 

14  10672  ^8            10744 

The  degrees  Balling  are  supposed  to  yidicate 

percentages  of  cane  sugar;    they  certamly  do 

not  correspond  with  the  percentage  of  matter 

dissolved  in  malt  worts.    The  tables  of  Schulze- 

Ostermann  (Zeit.  f.  d.  Res.  Brauw.  1878,  248 ; 

1883,  10)  are  also  used  extensively  and  give 

percentages,  and  grams  per  100  cc,  for  malt 

worts.    A  set  of  tables  drawn  up  by  Elion 

(Zeitsch.  angew.  Chem.  1890,  291  and  321)  can 

lay  greater  claim  to  accuracy,  and  also  give  an 

approximation  to  the  percentase  solids  in  beer 

residues.    According  to  this  table,  if  the  excess 

specific  gravity  ovier  1000  be  divided  by  the 

following  factors,  the  result  expresses  the  grams 

per  100  cc.  at  15**  C.    For  25  grams  per  100  cc. 

factor  is  307 ;  for  20  grams  308 ;  for  16  grams 

3-99 ;    for  10  grams  4O0 ;    for  6  grams  401 ; 

for  1  gram  4018. 

A   simple   calculation   will  show   that   the 

figures  expressing  brewers  pounds  extract,  per 

quarter,  per  barrel,  divided  oy  one  of  the  above 

factors  multiplied  by  0-336,  will  give  percentage 

extract.     The  factor  may  usually  be  taken  as  4, 

so  that  a  malt  yielding  90  lbs.  extract,  contains 

90 
2 — .>  oofl=^7  p.c  matter  soluble  on  mashing. 

Cciow  of  the  wort  or  beer  is  determined  by 
Lovibond's  tintometer.  Continental  analysts 
employ  decinormal  iodine  solution  as  the 
standard  for  comparison. 

Matter  soluble  in  cold  water  is  determined ; 
this  is  considered  to  give  an  indication  of  the 
manner  in  which  the  germination  was  carried 
out. 

Diastatic  activity,  measured  by  Ijntner's 
method  or  the  modification  laid  down  by  the 


686 


BREWING. 


Institute  of  Brewing  Committee,  is  a  useful 
indication  of  the  kilning. 

Nitrogen  is  conveniently  detennined  by  the 
Kjeldahl  process. 

Ash, — ^The  determination  of  ash  by  burning 
in  a  muffle  usually  sives  low  results,  owing 
to  the  loss  of  acid  radicals,  as  in  sulphates  or 
chlorides.  Suitable  precautions  must  be  taken 
to  prevent  this. 

Hope. — ^The  chemical  examination  of  hops 
has  already  been  referred  to. 

MdU  substitutes,  such  as  maize,  rice,  and 
their  preparations,  and  sugars  are  in  general 
analysed  by  methods  in  common  use.  The 
extract  of  starohy  material  is  determined  by 
the  addition  of  a  sufficient  quantity  of  malt  to 
convert  the  starch,  and  on  the  same  lines  as  that 
of  malt.  The  extract  yielded  by  the  sugars  is 
usually  expressed  as  *  pounds*  extract  per 
2  cwt.  per  barrel. 

Worts  and  beer  residues  are  examined  for 
matter  fermentable  by  yeast,  the  optical  activity, 
and  cupric  reducing  power  determined ;  and 
these  determinations  may  be  interpreted  in 
quantities  of  dextrin,  maltose,  and  other  matter 
with  some  approach  to  probability  (Morris,  J. 
Inst.  Brewing,  1895,  125). 

Beer. — ^The  most  important  determinations 
are  those  of  the  alcohol  and  the  unfermented 
residue,  from  which  can  be  deduced  the  original 
gravity  of  the  worts  before  fermentation.  This 
analysis  Ib  treated  of  in  great  detail  in  the 
Report  on  Original  Gravities  by  Thorpe  and 
Brown  (J.  Inst.  Brewing,  1914,  569),  and  on  this 
is  based  the  official  table  used  for  revenue 
purposes,  and  which  is  given  here  : — 


• 

Spirit  indicatioDS 

Corresponding  degrees 
of  gravity  lost 
.      4-26 

2      .         .         , 

.      8-50 

3      .         .         . 

.    12-90 

4      .          .          . 

.    17-30 

6      .          .         . 

.    21-86 

6      .         .         . 

.    26-40 

7     .         .         , 

.    31-00 

8     .         .         . 

.    35-65 

9      .         .         , 

.    40-30 

10     .         .         , 

.    45-00 

11      .         .         < 

.    49-85 

12     .         .         . 

.    54-85 

13      . 

.    59-95 

A  measured  quantity  of  the  beer  (usually  100 
O.C.)  is  taken,  mtered,  and  washed  into  a  dis- 
tilling flask;  a  condenser  ia  connected  and 
the  beer  distilled  to  about  four-fifths  of  its 
volume.  The  distillate  and  residue  are  each 
made  up  to  the  original  volume  and  the  specific 
gravities    taken,    usually     with    a    1000«grain 

rific-gravity  bottle.  The  table  gives  the 
^  ees  of  original  specific  gravity  equivalent 
to^the  specific  gravity  of  the  distillate.  The 
amount  of  alcohol  contained  in  the  distillate 
is  found  from  published  tables,  of  which  an 
excellent  one  appears  in  the  report  above 
mentioned,  and  is  also  published  separately. 

The  carbohydrates,  nitrogen,  ash,  and 
colour  of  beer  are  estimated  in  the  same  manner 
as  indicated  above  for  malt  worto. 

Preservatives, — Methods  for  the  estimation 
of  preservatives  in  beer  are  given  in  Bulletin  65 
ot  the  United  Stetes  Dept.  of  Agriculture,  1901, 


and  cireular  33  of  the  same,  March,  1907.  The 
most  common  is  sulphurous  acid ;  itycaimot  be 
estimated  by  direct  titration  with  iodine,  as  the 
sulphurous  acid  is  in  a  fairly  stable  state  of 
combination;  but  an  approximate  tatration 
may  be  made  by  first  decomposing  with  alkali, 
then  acidifying  and  titrating  (Ripper,  J.  pr. 
Chem.  (2),  46,  428).  The  most  satisfactory 
method  is  to  acidify  with  phosphoric  acid,  distil 
in  a  current  of  caroon  dioxide,  and  receive  the 
distillate  in  a  solution  of  iodine,  the  sulphuric 
acid  formed  is  weighed  as  barium  sulphate. 

Salicylic  acid  may  be  detected  by  extractmg 
a  concentrated  and  acidified  beer  residue  with 
a  mixture  of  petroleum  spirit  and  ether.  The 
ethereal  solution  is  drawn  off,  and  evaporated. 
The  residue  dissolved  in  water  gives  the  well- 
known  violet  colour  with  dilute  ferric  chloride 
if  salicylic  acid  is  present.  If  saccharin  is 
present,  this  would  be  extracted  at  the  same 
time,  and  recognised  by  ite  intense  sweetness. 
Boric  acid,  fluorides,  benzoic  acid  are  occasionally 
added.  Complete  details  of  beer  analytical 
methods  will  be  found  in  W.  Windisch,  Das. 
Chem.  Lab.  des  Brauers,  Berlin,  1907. 

Characteristics  and  Defects  of  Beer. — ^Beer 
should  have  a  pleasant  flavour  and  aroma,  be 
super-saturated  with  carbon  dioxide,  and  when 
poured  into  a  glass  be  bright  with  a  persistent 
foamy  head.  Beer  defecte  caused  by  the 
absence  of  these  characteristics  may  be  due  to 
chemical  or  biological  causes,  or  a  combination 
of  both.  Bacteria  are  often  a  cause  of  defective 
beer,  slight  changes  in  acidity  have  a  marked 
effect  on  the  susceptibility  of  the  beer,  slight 
increases  in  acidity  making  it  more,  and  slight 
increases  in  alkalinity  less,  stable. 

Aerobic  forms  such  as  the  ordinary  acetic 
acid  bacteria  do  not  grow  in  beer  charged  with 
carbon  dioxide.  One  of  the  most  common 
causes  of  spoilt  beer  is  Sardna  {Pedioeoccus 
cerevisicB),  this  causes  turbidi^  and  acidity. 
Another  bacteria  causing  a  silky  appearance 
and  production  of  acidity  is  saceharobacittus 
Pastorianus*  Ropineas  is  another  defect  caused 
by  bacteria;  there  are  several  bacteria  which 
can  cause  this,  usually  not  much  acidity  is 
produced,  nor  is  the  oeer  necessarily  torbid. 
The  composition  of  the  substance  which  sives 
the  viscosity  is  C^HigO.  (A.  J.  Brown,  Chem. 
Soc.  Trans.  J  886,  432 ;  Lafar,  Technical  Myco- 
logy, transL  by  C.  T.  C.  Salter,  London,  1898, 
1910). 

Wild  yeast  or  torula  growing  in  beer  will 
usually  produce  turbidi^,  and  sometimes 
unpleasant  flavour  and  smell.  This,  however, 
is  by  no  means  always  the  case,  and  if  bacteria 
do  not  obtein  access  to  the  beer,  when  the  yeast 
growth  is  completed,  it  setties  out  and  leaves 
the  beer  bright  with  an  altered,  but  possibly 
improved,  flavour. 

An  unpleasant  bitter  flavour  is  produced 
by  the  culture  yeast  if  the  greater  portion  be 
not  promptly  removed  at  the  termination  of  the 
primary  fermentation.  This  is  due  to  the  cell 
contento  passing  into  the  beer. 

If  beer  be  infected  with  bacteria  and  wild 
yeasto,  it  does  not  always  happen  that  these 
organisms  grow  and  spoil  the  beer.  Much  work 
has  been  done  to  determine  the  conditions 
which  influence  this.  H.  T.  Brown  (J.  Inst. 
Brewing,  1916,  344),  in  a  review  of  our  preseat 


BROMRIGON. 


687 


knowledge,  concludes  that  the  composition  of 
the  beer  has  no  influence  on  its  liability  to  wild 
yeast  ^wth  ;  but  that  allowing  for  the  bacteri- 
cidal influence  of  hops,  there  is  some  relation 
between  the  total  nitrogen  content  and  its 
liability  to  bacterial  disease.  It  is  disappointing 
that  the  large  amount  of  accumulated  Imowledge 
has  not  been  of  more  assistance  to  the  brewer 
in  avoiding  these  troubles.  We  are  led  back 
to  the  work  of  Pasteur  and  his  followers,  to  the 

E re-eminent  importance  of  mycology  to  the 
rewer. 
Beer  turbidity  is  often  caused  by  the  so- 
called  gluten  bodies  referred  to  above,  separating 
out  in  such  a  minute  form  as  not  to  settle. 
This  is  often  the  case  with  pasteurised  beer. 
Wallerstein  (U.S.  Pat  996820)  suggests  the 
addition  of  a  prOteolytio  enzyme  to  degrade 
these  bodies,  and  this  has  been  found  efficacious 
in  some  cases.  This  form  of  turbidity  is  closely 
connected  with  the  chemistry  of  the  colloids  of 
beer.  These  bodies  play  an  important  part  in 
the  production*  of  flavour  and  foam  retention. 
They  may  be  poisonous  to  yeast  and  also  affect 
the  stabilitv  of  beer  towards  bacteria.  Little 
is  known  of  their  properties,  but  a  statement  of 
the  present  stage  of  our  knowledge  will  be  found 
in  the  Report  on  Colloid  Chemistry,  Brit  Assoc. 
I9I7.  A.  L.  6. 

BRIDSUA  BARK  or  ASDUANA.  The  bark 
of  Briddia  numtana  is  a  useful  Indian  astringent 
(Dymook,  Pharm.  J.  [3]  7,  309). 

BRILLIAMT  ARCHIL,  -AZURDIB,  -BLACKS 
V.  Aso-  ooLouBnrQ  xattbis. 

BRILUAHT  CONGO,  -GROCliitN,  -DOUBLE 
SCARLET,  -GERANINB   v,    Azo-    coloubixo 


BRILUAHT  COTFOll  BLUB  v.  TBimimr 

lOTHAKS  00XX>UBINO  MATTSBS. 

BRILLfAMT  GREEN  v.  TBiPHnrTLiaTSAini 
ooLOUBnro  icattbbs. 

BRILUANT  ORANGE, -PONCEAU, -PUR. 
PURINE,    -SCARLET    v.     Azq-     ooLOUBiNa 


BRILLIANT  TBLU>W  v.  Azo-  ooloubivo 


BRIMSTONE  v.  Stjlfhub. 

BRINDONIA  DfPICA  v.  QAMoaiJL  dtoioa. 

BRIQUETTES  v.  Fxjml  ;  also  Fitoh. 

BRITANNIA  METAL.  Is  an  aUoy  of  van- 
able  composition,  usually  containing  only  tin 
and  antimony,  although  brass  and  bismuth  are 
sometimes  added. 

An  alloy  consisting  of  9  parts  of  tin  and  1 
part  of  antimony  is  attacked  slightly  by  solu- 
tions of  common  salt,  potassium,  ammonium, 
and  magnesium  chlorides,  potassium  sulphate, 
potassium  nitrate,  and  sodium  carbonate. 
Caustic  soda  has  a  more  marked  action  (Dingl. 
poly.  J.  221, 259). 

This  alloy  is  used  in  the  manufacture  of 
teapots,  spoons,  and  dish-covers. 

Article  made  from  it  may  be  coloured  bv 
heating  Uiem  for  15  to  30  minutes  in  a  bath 
made  By  mixing  2  lbs.  of  water,  1}  oz.  of  cream 
of  tartar,  (  oz.  of  tartar  emetic,  2  oz.  of  hydro- 
chloric acid,  i  lb.  of  pulverised  zinc,  and  1  oz.  of 
powdered  antimony.  This  gives  them  a  brilliant 
lustre. 

By  heating  in  a  bath  composed  of  1  part 
tartar  emetic,  1  part  cream  of  tartar,  3-4  of 
hydrochloric  acid,  and  3-4  of  ground  antimony, 


the  following  tints  may  be  obtained :    golden, 
copper-red,  violet,  and*  blue-grey. 

A  metallic  ring  can  be  given  to  articles  made 
of  Britannia  metal  by  heating  them  in  an  oil- 
bath  to  220^  and  then  cautiously  raising 
the  temperature  to  below  3^  above  the  fusing 
point  of  the  alloy.  Small  articles  must  be  kept 
at  this  temperature  for  from  15  to  30  minutes, 
large  articloB  for  one  hour;  the  bath  is  then 
allowed  to  cool.  The  rapidity  of  the  cooling 
seems  to  have  no  appreciable  enect  (D.  Ind.  Ztg. 
1867,  607)  {v.  Antimony). 

BRITISH  GUM  v,  Dbxtbin. 

BROCHANTITE.  A  hydrated  basic  copper 
sulphate,  CuS04'3Cu(OH)|»  forming  bright-green 
ortnorhombio  crystals,  found  in  Cornwall,  Urals, 
&c.  It  is  largely  present  in  some  of  the  Chilean 
copper  ,9re&  L.  J.  S. 

BROGGERITE.  A  crystallised  variety  of 
the  mineral  pitchblende  (q.v,)  or  uraninite,  found 
as  small,  isolated  octahedra  and  cubo-octahedra 
in  the  felspar  quarries  near  Moss  in  Norway.  It 
contains  about  80  p.c.  uranium  oxide,  together 
with  thorium,  lead,  fto.  Cleveite  is  a  very 
similar,  or  identical,  mineral  found  in  the  felspar 
quarries  near  Arendal  in  Norway.      L.  J.  S. 

BROMAL.  THbromaeetaldeliydt  CBr.CHO. 
P^pared  by  passing  bromine  into  a  solution  of 
paraldehyde  m  ethylacetate  (Pinner.  Annalen, 
179,  68),  or  by  passing  bromine  into  absolute 
alcohol,  fractionally  distilling  the  product,  and 
treating  the  fraction  boiling  at  165^-180*  with 
water.  The  bromalhydrate  thus  formed  is 
decomposed  on  distillation  into  bromal  and 
water  (Schaffer,  Ber.  1871, 366 ;  Lowig,  Annalen, 
8,  288).  Bromal  is  an  oily  liquid  boiling  at 
174^(760  mm.) ;  8p.gr.  3-34.  Alkalis  decompose 
it  on  heating  into  oromof orm  and  a  formate. 

Bromalhydrate  CBr,CH(OH)s.  Crystallises 
from  water  in  colourless  monoclinic  prisms  con- 
taining one  molecule  of  water  of  crvstallisation, 
m.p.  53*5*.  It  is  less  soluble  than  choralhydrate 
(Pope,  Ghem.  Soc.  Trans.  1899,  460). 

Bromal  aleoholates.  Bromalothylalcoholate 
is  a  orvstalline  solid,  m.p.  44* ;  readily  soluble 
in  aloonol,  sparingly  soluble  in  water  (Schaffer, 
2.c).  £t8id  (Compt.  rend.  114,  753)  has  de- 
scribed tiie  action  of  bromine  on  various  alcohols 
with  the  formation  of  different  bromal  alooho- 
lates. 

The  following  condensation  products  of 
bromal  have  been  prepared  :  Bromalammonia  ^ 
(8chiff  and  Tassinari,  Ber.  1877,  1786) ;  com- 
pound with  hexametkyleneiriamine  (Lederer, 
E^g.  Pat.  17693;  J.  Soc.  Chem.  Ind.  1897, 
1039) ;  compoimds  with  formaldehyde  (Pinner, 
Ber.  1900,  1432);  hromaldiaceiate  (Orabutti, 
Gazz.  chim.  itaL  1900,  30,  ii.  191);  bromal- 
glyoAaU  (Gabutti,  Chem.  Soc.  Abet.  1902,  i. 
261) ;  and  hromaUMorakarhamidit  (Kalle  and 
Co.,  Chem.  Soc.  Abstr.  1902,  L  429). 

BROMALBIN.  A  bromine  derivative  of 
protein. 

BROMAUN.  Trade  name  for  a  combina- 
tion of  hexamethylenetetramine  with  ethyl- 
bromide  used  in  the  treatment  of  neurasthenia 
and  epilepsy  (v.  Synth btio  Drugs. 

BROMBENZENE  v.  Bbbntl. 

a-BROMCARMINB  and  )3-BR0MCARMINE 

t;.  COOHINAAL. 

BROMEIGON.  Trade  name  for  an  albumin 
preparation  containing  bromine. 


688 


BROMELIA. 


BROBIELIA.  Trade  name  for  /S-naphthyl- 
ethyl  ether. 

BROmBTONE.  Trade  name  for  tribromo- 
tert-hntyl  alcohol  CBr,C(CH,),'OH.  Used  as  a 
sedative  and  aniesthetio  in  sea-sickness,  vomit- 
ing, chorea,  Ac. 

BROMINE.  Sym.  Br.  At  wt.  79*92.  An 
element  beloi^ing  to  the  class  of  the  halogens, 
and  the  only  element,  other  than  mercury,  which 
is  liquid  at  ordinary  temperature  and  pressure  ; 
discovered  by  Balard  in  1826.  Xame  from 
fip&fios,  a  stench.  Never  found  free ;  chiefly  in 
combination  with  alkalis  and  alkaline  earths. 
As  AgBr,  brom-  aigyrite  or  bromite,  also  as 
embofite  in  isomorphous  mixtures  with  AgCl  in 
Mexico,  Chile,  Honduras,  in  some  Sileeian  zine 
ores,  and  in  Chile  saltpetre.  In  sea  water,  in 
many  marine  plants  and  animals,  and  in  many 
saline  springs.  Bromine,  as  bromindigo,  has 
been  found  to  be  secreted  by  certain  species  of 
Murez,  and  is  an  essential  constituent  of  the 
Tyrian  purple  of  the  ancients.  Traces  of  it  are 
occasionally  to  be  met  with  in  coal,  and  hence 
in  gas  liquors. 

Bromine  is  contained  in  sea  water  in  the 
ratio  of  0*3  gram  Br  to  100  grams  CI.  Water 
from  the  Dead  Sea  contains  3  grams  of  Br  to 
100  grams  CI.  Some  marine  brines  analysed 
by  Hicks  gave  the  following  results  in  grams 
per  litre  :-*- 


8p.gr. 

1141 

1194 

1-193 

1-221 

1143 

1168 

1171 

1-202 

1-223 

1-062 

1066 

1-075 

1-069 

1-057 


Total 

solids 

17-00 

24-01 

22-04 

26-42 

18-40 

21-10 

22-40 

25-60 

26-98 

8-38 

8-82 

9-99 

9-27 

7-49 


CI. 

124-6 

176-9 

171-8 

202-9 

128-7 

154-1 

169-3 

189-2 

205-8 

55-6 

58-5 

65-7 

61-5 

50-5 


Br. 
1-3 
1-7 
1-6 
2*2 
0-6 
0-7 
0-3 
0-7 
1*7 
0-3 
0-4 
0-5 
0-3 
0-4 


At  ordinary  temperatures  bromine  is  a  dark 
brown-red  liquid  of  most  irritating  smell,  very 
volatile ;  vapour  yellowish-red,  and  becoming 
less  transparent  when  heated. 

It  boils  at  63''  and  solidifies  at  -73''  to  a 
brown-red  crystalline  mass  of  semi-metedllc 
lustre  and  conchoidal  fracture.  The  solidifying 
point  is  considerably  depressed  by  chlorine. 
The  specific  gravity  of  liquid  bromine  is 
3-18828,  074''  (Thorpe) ;  if  free  from  chlorine 
3-10227,  2574**  (Andrews  and  Carlton).  Co- 
efiicient  of  expansion  0-0011  between  25*^  and 
30"*.  Specific  heat  of  solid  0-08432  caL, 
of  liquid  0*1071  cal.,  of  gaseous  bromine  0-0555 
caL 

Latent  heat  of  evaporation  at  b.p.  45*6 
cal.,  critical  temperature  302*2®.  Vapour 
pressure: — 


"C. 

mm.  Hg 

°0. 

mm.  Hg 

-80-0 

0*13 

1*8 

67*3 

-69*9 

0*79 

4*0 

77*3 

-41-3 

2*89 

4*95 

82 

-19*4 

16*7 

6*96 

86*6 

-10-06 

360 

7*90 

95 

-  7*1 

44-6 

9-96 

104 

-    013 

02 

12*55 

119 

16*40 

18*16 

20-6 

22*66 

25*06 

29-8 


mm.  Hg 
139 
152-5 
172 
190 
212 
259 


34*7 
39-6 
46*6 
49*8 
54-7 
59-5 


mm.  Hg 
314 
378 
478 
563 
658 
768 


Tem]>. 
0-00 
10*34 
19*96 
30*17 
40*03 
49*86 


i00jMit6H,O    lOOpartsBr 
dUaolve       water  oontalu 


Solubility  of  bromine  in  water  (Winkler) : — 

1  part  Br  if 
dissolved  in 
parts  H.0 
24 

26*74 
27*94 


29-10 
29*02 
28-39 


parts  Br 
4*167 
3*740 
3*578 
3*437 
3*446 
3*552 


parts  Br 
4-00 
3*62 
3-46 
3*33 
3*34 
3-41 


The  solubility  of  bromine  in  water  is  in- 
fluenced by  the  presence  of  chlorine. 
If  I  litre  contains 


10 


it  dissolves 

46         66         66 

respectively.     Solubility 
1  moL  : — 

24 


15         20  grams  Q 


Na,S04 
(NMJjSO^  77-7 
NaCf  65-9 

grams  Br  per  litre. 
The  specific  gravity 

taining: — 

Parts  Br  per  litre 
10*72 
11*68 
12*05 
12-31 
19 
20 
.   31*69 


64  grams  Br 
in    the    presence    of 

NH^a  82-2 

NH^CtH.O,  340*5 
KBr  88*5 

of  bromine  water  oon- 

8p.gr. 
1-00901 
1-00931 
1*00996 
1*01223 
1-01491 
1-01807 
1-02367 


The  vapour  pressure  of  bromine  water  with 
liquid  bromine  as  bottom  body  : — 


Temperature 

0-0  *  a 

2-0 

3-0 

3-96 

4-96 

5-96 

6-2 

6-96 

7-96 
10-0 
12-5 
16-9 


mm.  Hg 

68 

76 

80 

83 

88 

92 

93 

96 
101 
110 
124 
146 


Bromine  water  when  cooled  depoaita  bromine 
hydrate  in  hyacinth-red  octahedral  crystals. 
Girau  (Ck>mpt  rend.  1914,  169,  246)  proposed, 
in  the  place  of  the  composition  BrgtlOH^O 
usually  given  (L5wig),  Brg,8IIsO  on  the  strength 
of  thermo-chemioal  and  analytical  data. 

The  solubility  of  water  in  bromine  is  imoer- 
tain;  according  to  Wildermann  100  moL  Br 
dissolve  0-4  moL  H.O.  Of  technical  importaDoe 
is  the  solubility  of  oromine  in  the  final  mother 
liquors  of  bromine  manufacture : 


At      2        10        20 
64*4    64-0    63*6 


30        40      50      55<* 
63-2    60*8    60-0    58*4 


grams  Br  are  soluble  in  1  litre. 

Bromine  is  very  soluble  in  alcohol,  etiier. 


Mrbon  disulphi'de,  chloroform,  c&rbon  tatra- 
chloride,  hvdrosen  chloride,  arsenic  chloride, 
mlphmyl  chloridja,  Hnlpbur  dioxide.  Sulphuric 
add  diwolvea  tracee  onlj.  It  is  miscible  with 
liquid  chlorine  sad  appreciably  soluble  in  com- 
pn«aed  saaea,  pari:icularij  oxygon,  which  at 
300  atm.  holds  6  times  the  quantit.v  with  which 
it  it  satiimted  at  ordinary  atmoapberio  pressure. 

Bromine  is  opaque  to  X-rays  j  tlie  d^ree 
of  opacity  of  bromine  compounds  is  in 
direot  pToportion  to  their  percentage  of  Br. 
Bromine  acta  violently  on  hydrogen,  aulphor, 
'  pho«phoTUS,  aneojo,  airtimonj,  tin,  alaminiura, 
the  heavy  metals,  and  potassium  ;  but  it  does 
not  react  irith  sodium  or  magnesium  even  on 
heating  to  200'.  It  combines  with  unsaturated 
organic  compounds  and  acts  as  a  bleacher  and 
disinfectant.  Its  vapour  acts  on  the  mucous 
membrane  and  occasions  great  irritation,  and 
has  been  used,  therefore,  in  gas  warfue. 

E^raction  and  Mnnufact-an.  —  Bromine 
occurs  in  nature  principally,  and  so  far  as  its 


industrial  prrpnration  is  concerned,  exolnalvely 
in  the  shape  of  bromidee,  accompanying  In  smHll 
quantities  the  chlorides  of  sodium,  calcium,  and 
magDesiuin.  Its  quantity  is  never  large  enoujih 
to  admit  of  ita  being  prepared  directly  from  the 
raw  material,  but  where  the  latter  is  in  tbe  first 
inttanee  worked  for  sodium  chloride  and  other 
salts,  the  bromide  accumulates  in  the  mother 
liquors,  and  can  be  recovered  from  these.  Thus 
Balard  discovered  bromine  in  the  mother 
liquors  obtained  on  making  common  salt  from 
sea.mter.  and  for  many  years  it  was  prepared 
from  the  mother  liquora  of  the  saltworks  at 
Kreuznach,  Schonebeck,  Neusalzwerk,  and  other 
plaoM  in  Germany.  It  was  also  found  in  184S. 
by  Alter,  in  similar  mother  liquors  in  America, 
especially  in  those  at  Natrona  and  Tarentnm, 
lat::'r  on  at  Pittsburg,  Syracuse,  Pomeray  (Ohio), 
and  in  the  Kaoawhn  region  in  West  Virginia 
(Mason  City,  Parkersville,   fto.). 

Manufacture   was    first  begun  in    1846   at 
Froeport,  Pa.     U.S.  Pat  12077  for  the  extrac- 


tion of  bromine  from  brine  was  taken  out  in 
IS54  by  Amalie  Stieren  of  Natrona,  Pa.  The 
American  bromine  indnatry  is  at  present  carried 
on  at  Saginaw,  St.  Charlee,  Bay  City,  Midland, 
and  Mount  Pleasant,  Michigan ;  at  Pomeroy, 
Ohio  i  Mason,  Hertford,  and  Maiden,  West 
Virginia ;  in  all  theee  localities,  except  Maiden, 
in  connection  with  the  salt  industry. 

Until  about  1X60  the  little  bromine  that  was 
made  was  nearly  all  used  for  scientiiic  purposes. 
Then,  however,  medicine  and  phot<^raphy  began 
to  demand  a  greater  supply  of  bromides,  and 
later  on  the  manufacture  of  coal-tar  dyes  raised 
an  even  more  extended  demand  for  bromine.  It 
now  became  remunerative  to  recover  it  in  the 
working  up  of  kelp  for  iodine,  but  this  yielded 
Mily  little  and  impure  bromine,  and  was  not 
long  continued.  An  idea  was  conceived  of 
recovering  it  from  the  water  of  the  Dead  Sea, 
but  the  project,  hardly  practicable  in  itself,  was 
abandoned  when  Fnnk  had  shown  that  an  ample 
aapniy  of  bromine  could  be  obtained  from  the 
mother  liqnoi*  of  the  Stassfnrt  potash  industry 
Vol.  I.— r. 


(o.  POTABSIUH  CHLOBiDx).     He  commenc«d  hit 

Siractioal  operations  in  1S05,  when  be  mano- 
actuied  about  750  kgs.  of  bromine  ;  in  1S67  the 
output  had  already  increased  to  7]  tons,  and  in 
1BS5  the  Stasifurt  production  of  bromine  was 
estimated  at  260  tons  per  annum,  the  price 
having  gone  down  from  50  or  60  (soraetiroes  as 
much  as  90)  marks  per  kilogram  to  070  mark. 
This  lowering  of  the  price  was  principally  due 
to  the  fact  that  since  1868  America  had  come  into 
the  market  with  bromine  made  from  the  above- 
named  saltworks ;  their  liquors  contained  it  in 
such  quantity  that  they  were  able  to  sell  much 
below  Stassfurt  prices. 

The  world's  production  before  the  wm  was 
practically  controlled  ty  the  '  Associated 
American  Producers,'  and  the  'German  Bro- 
mine Convention,'  in  Stassfurt  LeopoldahalL 

The  rise  in  price  caused  by  the  war  gave  a 
new  incentive  to  the  Amerioan  bromine  industry. 
However  many  of  the  new  producers,  after 
making  conaitferable  profits,  have  abandoned 
manufacture,  and  the  indnst^  in  the  vicinity  of 


090  BROl 

Saginaw,  Mich.,  for  iiutajice,  is  now  in  tho  hands 
of  a  few  firms  vho  buy  the  mother  liquors  from 

the  other  salt  producera. 

Chtmical  Procease'.^-'Sh.o  rew  in»t«ri«l 
worked  at  Stassfurt,  crude  caniallite  {v.  Po- 
TA8S1DU  OHLOKiDZ),  coTit&ins  bromine  to  the 
extent  of  from  O'JS  to  0'2B  p.o.  in  the  shape  of 
hrom-camaUite  MgBr,'KBr,6H,0,  JBomorphons 
with  camallite.  In  the  muiufncture  of  po- 
tiLwium  chloride,  the  magnesium  bromide 
aecumulatea  togetlier  with  magnesium  chloride 
in  the  mother  liquoTB,  which  contain  usually 
about  14  grams  KCl.  60  arams  MgSO,.  34B  grams 
Hg<?]„  12  grams  NaCl,  2-Aa  grams  Br  per 
litre,  and  have  sp.gr.  1'3I.  Ae  it  is  impossible 
to  separate  the  magnedum  bromide  by  fractional 
ciyitAlliiation,  the  bromine  is  always  extnicted 
,6  chemically,    being   re- 

1*  placed  by  a  current  of 


mixture  of  bromine,  chlorine,  and  water  vapour 
passed  through  the  lead  pipe  h  and  the  stone- 
ware condeoaing  coil  c  into  the  gloss  bottle  i>. 
holding  about  8  litres.  The  distillation  was 
carriea  on  until  the  pale  colour  oF  the  vapours 
in  the  glass  adapter  n  showed  that  no  more 
bromine  was  coming  over.  The  condensate 
separated  into  a  lower  layer  of  bromine  and  an 
upper  layer  ot  bromine  and  ohlorioe  water 
which  could  be  siphoned  o&  through  o  into 
vessel  X,  and  was  added  to  a  subsequent  chaige. 
Uncondensed  vapours  passed  into  vessel  v  filled 
with  iron  turnings  and  water,  and  fitted  with  a 
collar,  p,  to  allow  for  frothing,  with  a  nm-off 
into  jar  o.  Each  operation,  lasting  an  hour  to 
an  hour  and  a  half,  was  terminated  by  knocking 
out  plug  I,  and  runningoS  the  liquor  through  the 
oovered  culvert  nt  ooimeoted  to  the  factory 
ohimnev. 

cess  was  very  small. 
Z  5  kg?,  bromine^  the 
not  more  than  0-1 
The  intrrmittent 
rbacka — loss  of  time 
mtamination  of  the 
jitages  gave  rise  to 
I,  the  first  of  which 
178. 


prepared  outside  and  passed  Unto  the  solutions,  i 
cheap  compressed  chlorine  m  steel  cylinders 
being  nowadays  available  (or  that  purpose- 
In  the  early  days  of  the  bromme  industry,  \ 
the  extraction  was  always  done  by  intermittent 
working.  One  of  the  first  appar*tuB  employed  ■ 
was  demised  by  Frank,  and  is  shown  in  Fin.  l.| 
It  consisted  of  a  square  vessel  or  still,  a,  made  of. 
sandstone  or  slate  properly  jointed  together,  of 
about  3  cubic  metres  caf>acity,  which  wai 
charged  with  a  deSnitequantity  of  mother  liquor 
previously  heated  to  60  in  tank  b  by  steam  coil 
i;  about  200  kgs.  of  mangaoese  ore.sufGcient  for 
several  operations,  were  spread  on  the  false 
bottom  a.  After  closing  the  man-hole  /.  the 
required  qnantity  of  sulphuric  acid  of  sp.gr.  1'7 
was  run  in  through  pipe  g,  which  was  subse- 
quently stopped  up  with  clay,  and  live  steam 
was  pE^sed  into  the  liquor  thiough  pipe  jb.  The 
chlorine  evolved  on  boiling  acted  upon  the  mag- 
nesium bromide  present  and  liberated  bromine. 
This  oame  over  pure  at  first,  hut  above  7Q*  a 


ne  time  chlorine  na 
gmeraled  ontttdc 

'  and  steam  into  the 
lowest  veaael,  and 
in  cODDtor-ciiireat 
to  the  higher  ones. 
He  thus  obtained 

of  bromine  on  the 

i   one  hand,   wad  a 

;   solution   of   mag. 

I   neaium      chloride 

I  practically     freed 

i   from  bromine  and 

nncontaminated 

with     mangane^ 

salts,  on  the  other. 

After  »  time,  chlo- 

into  the  second  lowest  vessel,  and  steam  only 
into  the  lowest,  to  tree  its  contenta  from  chlorine 
before  running  off-  However,  the  high  pressore 
required    to    force    the    chlorine  gas   throngh 

several  successive  layers  of  the  lique '-' 

great  difficulties  in  the  i' 

this  plant.    Theee  were  o' 

tion  of  the  scrubber  principle  in  the  apparatus. 

patented  in  18S2  by  the  Leopotdshatl  L'hemioal 

Works  (D.  R.  P.  19780],  and  shown  in  Fig.  2. 

The  heated  mother  liquor  flows  through  the 
water-sealed  pipe  a  into  column  i  constmcled  of 
stoneware  or  acid-resisting  st«ne,  where  it  W 
evenly  distributed  by  pipe  b.  The  oolumn  is 
fitted  with  stoneware  balls,  e,  c  testing  on  a 
crating  which  effects  a  good  oontaet  of  tits 
liquor  with  the  chlorine  gas  ascending  through 
pipe  2.  This  pipe  is  wide  enough  to  serve  also  as 
outlet  for  the  liquor  which  runs  into  the  st 
vessel  R,  provided  with  a  number  of  supi 
posed  flagstone  shelves  oompelling  the  li 
to  flow  in  a  zigiag  course,  and  finally  i 


of  the  liquor  presented 
design  and  workinc  ot 
ivercome  by  the  appLca- 


BROMINE. 


691 


through  pipe  t .  Steam  is  forced  into  this 
7eesel  by  means  of  a  stone  pipe  g  and  is  distri- 
buted through  perforations  m  its  base.  The 
contents  of  B,  which  is  always  full,  are  kept 
boiling,  and  the  steam  rises  principally  throush 
holes  in  the  flagstones,  thereby  freeing  we 
liquor  from  chlorine  and  bromine.  The  vapours 
meet  tlie  current  of  fresh  chlorine  arriving 
through  pipe  I  (shown  in  dotted  lines),  which  is 
conveyed  through  pipe  z  into  the  tower  a, 
decomposing  the  magnesium  bromide.  The 
bromine  is  token  off  on  top,  and  passed  by  pipe  o 
tlirough  the-  stoneware  condenser  p  into  tJie 
receiver  q.  The  unoondensed  vapours  are  led 
through  X,  into  receptacle  n,  and  arrested  in  the 
smaller  scrubber  d  suspended  by  rod  i,  and  fitted 
with  iron  borings,  kept  moist  b^  a  stream  of 
water  from  tube/.  The  iron  bromide  collected  in 
n  is  siphoned  off  through  v  into  jar  w.  The  regu- 
larity_of  the  current  of  chlorine  arriving  from  m  is 
controlled  by  the  amount  of  water 
condensing  in  the  bend  of  the  glass 
tube  h.  If  too  much  water  has 
UK  accumulated,  it   is  blown   through 

ji  the  rubber  tube  u  into  the  chlorine 

_TW         washer  D.    By  filling  the  bend  of  h 

wiUi  water,  the  current  of 
may  be  interrupted. 
Of     late     years 
chlorine  electro- 
l3rticany  prepared 
and    compressed 
in  steel  cylinders 
has    been    used, 
^    whereby  the  re- 
^     gularity    of    the 
current  is  under 
complete  control. 
The  ap- 
paratus pa- 


'* 


'ti^ 


Fio.  3. 


tented  by  Wiinsche-Sauerbrey  (Fig.  3)  is  based 
on  the  same  principle  as  the  foregoing.  It  is, 
however,  technically  more  perfect  and  conse- 
quently much  superior  in  efiicienoy. 

It  consists  of  a  decomposing  vessel  A,  a 
steaming  vessel  B,a  condenser  o,  and  an  auxiliary 
condenser  d.  The  four  units  are  built  up  of 
oast-iron  elements  of  hexagonal  cross-section, 
lined  with  stoneware  plates  and  filled  with  a 
very  large  number,  several  thousands,  of 
specially  designed  contact  bodies  (D.  B.  P. 
168715)  which  rest  on  gratings  of  the  same 
material.  The  four  unite  are  so  arranged  in 
heiffht  that  a  perfect  counter-current  is  obtained, 
and  in  both  tne  decomposer  and  condenser  two 
centre  gratings  are  provided,  on  order  to  keep 
a  free  space.  The  chlorine  is  passed  into  the 
decomposer  at  ft,  the  liquor  entering  through  a 
at  a  temperature  of  66^ ;  after  treatment  in  this 
unit  it  runs  into  the  steaming  vessel  through  pipe 
/,  where  it  is  freed  from  chlorine  and  bromine 
vapours  by  means  of  live  steam  entering  at  (f, 
the  vapours  passinc  into  the  free  space  of  the 
decomposer.  The  bromine  leaves  the  decom- 
poser at  a  temperature  of  about  95®  and  under- 


§oes  preliminary  cooling  in  the  auxiliary  con- 
enser  d,  but  is  completely  condensed  in  the 
principal  condenser  by  a'  stream  of  water, 
passing  subsequently  a  bromine  and  water 
separator. 

The  features  of  this  apparatus  are  the  com- 
plete recoveiy  of  bromine  and  the  thorough 
utilisation  of  steam.      Although  of  moderate 
dimensions,  the  apparatus  is  capable,  on  account 
of  the  number  and  arrangement   of  contact 
bodies,  to  recover  250-270  kgs.  bromine  from 
1 50  cub.  m.  liquor  in  24  hours.    It  requires  0*6  kfz. 
chlorine  for  every  kg.  of  bromine  made,  and  only 
3  to  5  kgs.  bromine  are  necessary  in  the  form  of 
iron   bromide  for  the  subsequent  removal  of 
chlorine  from  100  kg?,  crude  bromine.    The  cost 
of  production  of  1  kg.  bromine  is  0*45  to  0'60 
mark. 

Whilst  the  value  of  WQnsche's  apparatus 
depends  on  the  most  favourable  distribution  and 
utilisation  of  gas  and  liquor,  Kubierschky  has 
designed  a  plant  (Ger.  Pat.  194567)  in  which  the 
counter-current  proper  is  divided  into  a  number 
of  systematically  arranged  parallel  currento. 
recognising  the  fact  that  bromine  vapour  will 
be  heavier  the  purer  it  becomes.  As  the  ratio 
of  the  density  of  water  to  that  of  bromine  is 
18 :  160,  a  simple  upward  current  cannot  possibly 
yield  the  best  separation,  as  under- currents  will 
always  be  set  up. 

'the  apparatus  consiste  of  a  single  tower 
oolumn,  shown  in  Fig.  4. 

It  is  lined  with  stoneware  and  divided  into 
superimposed  compartmenta,  the  division  plates 
being  liquor-sealed  and  allowing  liquid  to  pass, 
but  not  gas.  The  compartments  are  pro- 
vided with  perforated  plates  pp  or  other  contact 
bodies.  Communication  between  the  compart- 
mente  is  established  by  tubes  rr  so  arranged 
that  the  vapour  always  enters  from  the  lower 
compartment  into  the  uppes  part  of  the  next 
higher  one,  then  descends  over  the  plates  along 
with  the  liquid,  and  enters  the  vapour  pipe  near 
the  bottom,  passing  through  this  pipe  again  to 
the  top  of  the  next  compartment,  and  so  forth. 

The    previously    heatea  | 

mother  liquor   enters  at    ^ 

the  top  of  the   column, 

runs    down   in  a  direct 

course    and    is    met    by 

chlorine  introduced  in  the 

lower    part.      Steam    is 

passed  into  the  bottom 

compartment,  and  follows 

the      course     described. 

The    bromine,   not    sub- 
jected to  under-currente, 

issues    at    a    from    the 

column  and  is  condensed 

in  an  earthemware  coil. 
Although  of   extreme 

simplicity,  tliis  apparatus 

is  much   superior  to  all 

the   others,  especially  in 

regard     to     yield,     this 

amounting  to  from  90  to 

95  p.c.  of  the  bromine  present  in  the  crude  liquors. 
The  mother  liquors,  obtained  by  spontaneous 

evaporation  of  sea- water  to  sp.gr.  1*274  at  the 

salt  works  of  Salin  de  Giroud,  South  of  France, 

are  used  for  the  production  of  bromine.    They 

are  further  concentrated  to  specific  gravity  of 


692 


BROMINE. 


I '308  and  allowed  to  ciystalUse  during  the 
winter.  After  removing  the  magneaiam  sul- 
phate, bromine  is  extracted  in  the  following 
spring  by  pumping  the  liquors  into  vessels  of 
SR)  cub.  m.  each,  from  which  they  descend  in  a 
regulated  stream  into  stone  rectifying  columns 
throush  which  a  current  of  chlorine,  from 
cylinders,  and  a  current  of  steam  ascends.  The 
bromine,  after  passing  through  an  inclined 
U-tube  and  a  condensing  coil,  is  separated  from 
the  water  by  gravity,  uie  bromine-water  being 
returned  to  the  column.  The  crude  bromine  is 
rectified  by  passing  steam  through  it,  which 
carries  away  tne  chlorine  and  part  of  the  bromine. 
Three  units  are  employed,  each  of  which  deals 
with  60  to  60  cub.  m.  of  mother  Uquor  in  24 
hours,  and  yields  about  160  kilos  of  bromine 
Forty-four  tons  of  bromine  containing  only 
about  1  p.o.  of  chlorine  are  thus  obtained 
annually  from  15,000  cub.  m.  of  mother  liquor. 
The  Honors,  after  the  extraction  of  bromine,  are 
worked  up  for  potassium  chloride. 

In  America  the  manufacture  is  carried  on  in 
the  majoritv  of  works  in  Ohio,  West  Virginia,  and 
Michigan,  by  the  intermittent  process.  The 
bittern  from  the  main  grainers  of  the  salt  works 
is  further  concentrated  to  a  sp.gr.  of  about  1*38 
(hot),  and  then  passed  to  tne  bromine  stills. 
Most  of  these  are  made  from  sandstone  quarried 
at  Buena  Vista,  near  Portsmouth,  Ohio,  where 
the  sandstone  is  practically  free  from  iron  oxide 
and  is  of  close  texture.  The  shape  and  con- 
stmotion  differ  in  the  various  plants,  and  their 
working  capacity  ranges  from  400  to  1200  f^allons 
of  liquid.  Sodium  chlorate  and  sulphuric  acid 
of  sp.gr.  1*84  are  used  in  liberating  tne  bromine 
from  the  bittern.  The  use  of  manganese 
dioxide  and  potassium  chlorate  has  been  dis- 
continued. Steam  is  passed  into  the  solution 
and,  as  the  temperature  rises,  a  reaction  takes 
place  approximately  represented  by  the  following 
equation : — 

3MgBr,+3Hg804-fNaC10j 

=6Br+NaCl+3MgS04-|-3H,0 

The  bromine  set  free  passes  from  the  still 
together  with  any  excess  of  chlorine  which  is 
liberated.  The  bromine  vapour  is  freed  from 
chlorine  after  passing  through  washers  filled  with 
milk  of  lime  forming  calcium  chloride  and  calcium 
hypochlorite.  Some  bromine  is  taken  up  by  the 
Ume,  but  is  recovered  later.  The  bulk  of  the 
bromine  vapour  is  condensed  in  three  lead  ooiLb 
arranged  in  series,  each  of  which  discharges  tiie 
condensate  into  slass  bottles,  whilst  any  bromine 
passing  the  last  bottle  is  caught  in  towers  6  feet 
to  8  feet  high  and  2  feet  to  2  feet  6  inches  wide, 
made  of  sewer  pipe  and  filled  with  coke.  The 
bromine  caught  oeyond  the  first  bottle  is  usually 
rather  dilute  and  may  be  returned  to  the  still. 
The  lead  pipes  have  lately  been  replaced  by 
stoneware  coils  in  several  works.  About 
35  lbs.  of  bromine  are  obtained  from  700  gallons 
of  bittern. 

The  drawbacks  of  the  intermittent  process 
have  led  to  the    introduction  of    continuous 

Srocesses.    The    Dow    Chemical    Company    of 
fidland,    Mich.,   has   patented   a   number   of 
modifications  of  these. 

The  chlorine  used  may  be  produced  chemi- 
cally or  eleotrolytically  within  the  reacting  mass, 
or  introduced  from  outeide.     In  the  place  of 


steam  for  the  removal  of  free  bromine  a^  current 
of  air  is  used.  Ihe  bromine  is  abstracted  from 
the  bromine-laden  air  by  chemical  ro-agents 
such  as  iron  turnings,  Ume,  sodium  bicarbonate, 
and  others.  These  ore  worked  up  for  pure 
bromine  or  bromine  salts  by  subsidiary  processes ; 
for  instance,  the  ferric  bromide  solution  may  be 
converted  into  solid  ferrous  bromide  by  tieai- 
ment  with  further  iron. 

Electrolytic  ProccMCB. — Of  recent  jrears, 
efforts  have  been  made  to  effect  the  separation  of 
bromine  from  the  magnesium-bromide  liquors 
by  means  of  electrolysis.  A  number  of  pro- 
cesses have  been  devised  by  Wunsche.  Hopfner, 
Nalmsen,  Pemsel,  Rinck,  Dow,  and  Kossuth, 
but  although  in  some  cases  plants  have  been 
working  with  more  or  less  success,  their 
introduction  has  Hot  become  generaL  All 
but     the     last-named     process     employ    dia- 

Shragms,  to  avoid  secondary  reactions, 
.ossuth  works  without  this,  and  achieves  a 
great  simplicity  of  plant  and  working,  but  at  the 
expense  of  current  required.  The  yield  of 
electric  energy  is  40-50  p.c.  in  his  case,  and 
not  more  than  about  70  p.c.  in  any  other  method. 
This  low  yield  is  laivefy  due  to  the  eztremdy 
small  percentaee  of  bromine  in  the  liquors  and 
the  consequently  laise  bulk  to  be  dealt  with,  and 
to  the  formation  of  bromates  and  chlorates. 
The  formation  of  solid  magnesia  is  another 
drawback. 

In  nearly  all  the  electrolytic  methods  pro- 
posed, the  bromine  remains  dissolved  in  tne 
solution  and  must  be  recovered  by  the  processes 
described  above. 

Purification  of  Bromine. — Crude  bromine,  as 
obtained  by  most  of  the  processes  described, 
contains  very  small  quantities  of  iodine,  cyano- 
een,  bromoform  and  carbon  tetrabromide.  lead 
bromide,  and  as  principal  impurity  from  1  to 
4  p.c.  of  chlorine  as  chloride  of  bromine.  The 
oldest  method  of  purification  consisted  in  agitat- 
ing the  crude  bromine  with  a  solution  of  potas- 
sium or  ferrous  bromide.  On  account  of  the 
frequent  breakages  of  the  glass  veeselB  employed, 
this  method  was  replac^  by  that  of  redis- 
tillation. In  some  places  glass  retorts  were 
used  for  this  purpose,  oontaining  about  15  kgs. 
and  heated  in  sand-baths.  Only  3  or  4  charges 
could  be  worked  in  one  vessel,  and  fracture  of 
the  retorts  was  a  not  unfrequent  occurrence. 
In  Stassf urt  sandstones  stills  were  and  are  still 
employed.  These  wero  square  troughs  with  a 
stone  cover,  holding  about  1  cubic  metre.  The 
distillation  is  earned  out  in  the  presence  of 
ferrous  or  calcium  bromide,  these  liquors  being, 
when  used  up,  added  to  the  original  mother 
li  quors.  Of  late  vears  advantage  has  been  taken 
of  the  improvea  products  of  the  stoneware 
industry,  and  stiUs  of  this  material  are  laively 
used.  To  avoid  the  occasional  cracking  of  these 
stiUs,  Mitreiter  employs  vessek  of  boiler  plate 
lined  with  a  bromine-resisting  material. 

The  still  is  charged  with  200  litres  ferrous 
bromide  solution  of  13^  to  WB6,  and  about 
600  litres  xrude  bromine.  The  temperature  is 
gently  raised  by  direct  steam  up  to  tne  boiling- 
point.  Double  decomposition  ensues  between 
ohlorine  and  ferrous  bromide,  and  bromine 
distils  over  and  is  condensed  in  a  stoneware 
coil,  separated  from  water  and  then  oontains 
only  from  0*06  to  O'lO  p.c  chlorine. 


BROMINE. 


69S 


%, 


t 


Pure  bromine  may  be  made»  aocording  to 
Bantow,  without  the  aid  of  steam  or  heal^  by 
adding  solphnrio  acid  to  a  mixture  of  5  parts  of 
bromide  to  1  part  of  bromate  in  a  cement-lined 
tub  cooled  by  a  lead  ooil»  but  kept  above  the 
crystallising  point  of  the  sodium  sulphate  formed. 
The  free  bromine  formed  according  to  the 
equation : — 

oNaBr+NaBrO,+3HjS04 

=3Na,S04+8Br+3H,0 

can  be  drawn  off  from  the  bottom  of  the  con- 
denser, the  yield  being  95  p.c.  of  liquid  bromine, 
whilst  the  remainder  is 
blown  out  from  the 
solution  with  a  current 
of  air  and  recovered 
with  alkali. 

In  another  process, 
patented  by  Barstow 
(Fig.  5),  a  strong  iron 
bromide  solution  is  fed 
from  tank  2  into  the 
top  of  a  tailings  tower, 
1,  passes  through  a  con- 
densing coil,  3,  thence 
through  a  re-action 
column,  4,  in  which  it 
meets  a  rising  stream  of 
chlorine  gas  supplied 
from  5.  The  mixture  of 
iron  chloride  and  liquid 
bromine  flows  down- 
ward through  the  re- 
action column,  and  from 
it    through    a    cooling 


^' 


:>> 


i:»: 


C 


iti> 


•CI 


worm,  7,  to  a  con- 
tainer, 8,  where  it  is 
separated  by  cravity . 
Any  vapour  formed  by  the 
heat  produced  in  the  re- 
action column,  or  carried 
away  by  air,  which  may 
be  contained  in  the  chlo- 
rine giftS,  is  re-condensed  in  3  or  scrubbed  out 
in  tower  1.  Any  chlorine  contained  in  the 
crude  bromine  is  removed  by  agitation  with  an 
iron  bromide  solution,  and  the  bromine  retained 
by  the  iron  chloride  solution  may  be  blown  out 
with  air  and  re-absorbed  with  a  solution  of 
ferrous  bromide.  No  steam  is  used  in  the  pro- 
cess, and  the  iron  chloride  can  be  produced  as  a 
commercial  solution  of  sp.gr.  1*32. 

Recent  processes  attempt  the  purification  by 
rectifying  without  the  aid  of  chemical  agents. 
Kubierscnky  (Ger.  Pat.  174848)  employs  in  con« 
nection  with  his  separating  apparatus  a  refining 
tower ;  the  crude  bromme  flows  downwards 
into  a  vessel  charged  with  bromine  and  kept  at 
boiling  temperature.  The  chlorine  rises  in  the 
tower,  and  the  boiling  bromine,  freed  from 
chlorine,  is  continually  siphoned  off  and  cooled. 
The  German  Solvay  Works  (Ger.  Pat.  205448) 
have  found  that  in  raising  the  temperature  of 
-crude  bromine  very  slowly  and  keeping  it  just 
under  its  boiling-point,  it  is  possible  to  free  it 
entirely  from  its  chlorine.  The  time  factor  is  of 
great  importance  for  the  successful  carrying  out 
<A  their  process. 


On  heating  a  charge  to  59°  for  36  to  40  hours, 
it  is  possible  to  remove  practioall  v  all  the  chlorine 
with  not  much  more  bromine  than  corresponds 
to  the  composition  of  bromide  of  chlorine. 

Bromine  is  sold  in  strong,  white,  stoppered 
bottles,  holding  1  litre,  and  containing  2}  or  3 
kilos.  The  glass  stoppers  fnust  be  well  ground ; 
they  are  secured  by  pourine  some  shellac  on  to 
the  joint,  covering  tnem  with  clay  putty,  and 
tying  wet  parchment  paper  over  alL  From  four 
to  twelve  such  bottles  are  placed  in  a  wooden 
bozy  the  spaces  between  being  tightly  filled  with 
kieselgnhr  or  brown-coal  ashes,  depending  upon 
whether  the  bromine  is  exported  or  sold  for 
inland  consumption. 

The  principal  applications  of  bromine, 
whether  m  the  free  state  or  in  the  shape  of 
bromides,  are  in  photography,  in  medicine,  in 
the  manufacture  of  coal-tar  dyes  (especially 
eosine),  and  in  scientific  and  analytical  chemistry; 
in  the  latter  it  has  to  a  great  extent  taken  the 
place  of  chlorine,  owing  to  the  greater  con- 
venience of  its  manipulation.  A  similar  substi- 
tution has  been  proposed  for  many  technicAl 
purposes.  It  is  used  in  the  extraction  of  gold 
and  the  refining  ot  platinum,  and  in  connection 
with  the  manufacture  of  Prussian  blue  and 
potassium  permanganate.  It  is  also  a  disin- 
fectant, and  has  found  some  application  foi 
this  purpose,  especially  in  the  shape  of  hrrnnwrn 
«oZtVft/!ca<ttm  patented  by  Frank  (Ger.  Pat.  21644). 
This  is  kieselguhr  made  plastic  by  means  of 
molasses,  &o.,  pressed  into  sticks  of  \-  and  (-inch 
diameter,  driea,  burned  to  the  extent  that  the 
sticks  acquire  a  sufficient  degree  of  hardness 
without  losing  their  porosity,  and  saturated 
with  liquid  bromine  in  wide- mouthed  stoppered 
fflass  bottles.  After  the  excess  of  bromine  has 
been  poured  off,  the  sticks  remain  behind,  con- 
taining about  75  p.c.  of  the  weight  of  bromine, 
and  are  sold  m  the  same  bottles.  This  is  a  ver^ 
convenient  form  of  applying  it,  as  a  certain 
number  of  sticks  represent  a  given  weight,  and 
no  weighing  out  of  liquid  bromine  is  required. 

Bromide  of  iron  is  made  at  Staaofurt  and  in 
America,  and  serves  principally  as  raw  material 
for  the  mcmufaoture  of  potassium  and  sodium 
bromide.  It  is  a  compound  of  the  formula 
Fe,Br„  containing  56-70  p.c.  bromine,  up  to 
0'5  chlorine,  18-19  p.c.  iron,  and  10-15  p.c. 
water  and  insoluble  matter.  The  older  method 
for  its  manufacture  consists  in  passing  bromine 
vapours  free  from  chlorine  over  iron  borings  or 
turnings  contained  in  a  cast-iron  or  stoneware 
vessel,  and  kept  moist  by  a  stream  of  water. 
The  solution  obtained  is  passed  through  a  filter 
cloth  or  sand  filter  to  remove  impurities,  notably 
carbon,  and  evaporated  in  cast-iron  pans, 
whereby  enough  bromine  la  added  to  obtain  the 
compound  Fe,Br,.  The  brown-red  solution 
is  concentrated  to  a  pasty  consistency  and 
allowed  to  cool  to  a  black  crystalline  mass. 

The  Associated  Chemical  Works  of  Leopolds- 
hall  have  introduced  a  method  whereoy  a 
charge  of  1  ton  of  steel  wire  and  turnings  is 
treated  in  a  closed  stone  trough  with  a  mixture 
fk  bromine  vapour  and  steam  in  the  right 
proportion.  The  admission  of  bromine  is  so 
regulated  that  no  bromine  vapours  are  visible 
through  a  sight-glass  provided  on  the  outlet  pipe 
which  is  connected  to  a  little  scrubber  acting  as  a 
catch-boz.    As  soon  as  brown  vapours  and  the 


694 


BROMINE. 


falling  of  the  temperature  ivom  170*"  to  lOO*"  indi- 
cate a  ieasening  of  the  activity  ol  the  iion,  the 
operation  is  tenninated  and  the  solution  run  off. 
Being  sufficiently  concentrated,  the  solution 
obtained  in  the  process  may  be  run  direct  into 
the  transport  barrels,  where  it  is  allowed  to 
crystallise.  * 

Bromine  salt  In  connection  with  the 
manufacture  of  bromine  a  substance  commonly 
called  '  bromine  salt  *  is  produced,  which  fincu 
application  in  the  extraction  of  golil  ores.  It  is 
practically  the  mixture  NaBrO,+2NaBr,  and 
IS  made  b^  saturating  concentrated  caustic  soda 
solution  with  bromine.  The  solid  salt  obtained 
after  draining  off  the  mother  liquor — ^whjch  is 
evaporated— has  the  approximate  oompoettion 
INaBrOa+SNaBr.  To  this  sodium  bromate, 
electrolytically  prepared  from  bromide,  is  added, 
and  the  mixture  nnely  ground  and  packed  in 
kegs. 

Hydrobromie  aeld.  HBr.  Bromhydrie  add ; 
Hydiigtn  bromide.  A  colourless  pungent  gas 
of  irritating  smell;  fumes  strongly  in  the  air. 
Ck>ndenses  to  a  liquid  at  —73^.  May  be  ob- 
tained synthetically  by  passing  bromine  and 
hydrogen  through  a  hot  tube  or  over  heated 
platinum.  Best  prepared  by  action  of  phos> 
phorus  and  bromine  on  water,  5Br+P+4U,OB 
H,PO4+0HBr ;  or  by  the  action  of  a  concen- 
trated solution  of  HsPOa  on  KBr ;  or  by  drop- 
ping Br  upon  melted  paraffin  heated  to  185°. 

Qas  very  soluble  in  water ;  weight  of  normal 
litre  3*6442  grams;  solution  wl^n  saturated 
forms  a  colourless,  strongly  acid  liquid  of 
sp.gr.  1*78,  and  contains  82  p.c.  HBr  by  weight, 
corresponding  to  the  formula  HBr,HaO.  If 
the  concentrated  acid  be  heated  at  ordhiary 
pressures,  the  gas  is  evolved  until  the  amount 
of  HBr  in  the  solution  sinks  to  47-48  p.c.,  when 
the  liquid  boils  constantly  at  126°  under  a 
pressure  of  760  mm.  This  proportion  of  HBr 
corresponds  to  HBr+6HaO,  but  the  liquid  is 
not  a  true  hydrate,  since  the  composition  is 
altered  by  varying  the  pressure ;  tnus  if  the 
pressure  be  raised  to  1*95  mm.,  the  solution  boils 
at  153°  and  contains  46'3  p.c.  HBr. 

The  sp.gr.  at  15°  and  p.o.  composition  of 
aqueous  solutions  of  hydrobromic  acid,  is  given 
in  the  following  table  (Wright,  Chem.  News,  23, 
242):— 


Sp.  gr.  HBr  p.o. 
1-080        10-4 
1190       23-5 
1-248       30-0 


Sp.gr. 
1-385 
1-475 
1-515 


HBr  p.c. 
40-8 
49-5 
49-8 


For  pharmaoeuticcd  purposes  a  dilute  solu- 
tion of  hybrobromio  acid  may  be  prepared  by 
dissolving  84]^  grains  of  potassium  bromide  in  a 
fluid  ounce  of  water  and  adding  9  srains  of 
tartaric  acid  to  the  solution.  After  stanoing,  acid 
potassium  tartrate  ciystallises  out  and  the 
solution  contains  about  10  p.c.  of  hydrobromic 
acid.  Hydrobromic  £bcid  has  been  used  in  the 
treatment  of  ear  complaints.  B.  L. 

BROMINOL  (braminoleum).  Trade  name  for 
brominated  sesam^  oiL 

BROMIPIN,  BROMOFIN.  A  combination  of 
bromine  with  sesam^  oil  employed  in  medicine 
(v.  SYNTHano  Dbuqs). 

BROMITE  or  BROMTRTTE.  Native  sUver 
bromide,  found  in  Mexico  and  in  CSule  (v. 
SniVBB) 


w-BROMOACBTOPHraOHB  «.  Kstohxb. 

BROMOCHINOL    Trade    name    for 
dibromosaliqylate  of  quinine. 

BROMOCOLL  v.  STKTHxno  Dbuqs. 

BROMOFORM.  TribrommethaneCHBT^T}nB 
substance  is  occasionally  met  with  in  the  liquid 
left  after  the  rectification  of  bromine,  in  wluon  it 
occurs  associated  with  cMoro&romo/Drm  GHBr,Gl 
(Dyson,  Chem.  Soc.  Trans.  43,  46)  and  carbon 
teirabromide  CBr^  (Hamilton,  ibid,  39,  48). 

Preparaiion. — ^It  may  be  obtained  by  mixiDg 
100  ac.  soda  lye,  200  c.c.  acetone,  and  20  cc. 
bromine.  When  the  reaction  has  oeased*  10  ac. 
acetone  are  added  to  remove  the  yellow  colour 
of  the  hypobromite,  the  layer  of  bromoform 
which  separates  being  tapped  off  and  rectified. 
Yield  75  p.c.  (Denigte,  J.  Phann.  Ghim.  24, 243). 
It  may  also  be  prepared  by  the  simultaxieoDS 
action  of  bromine  and  caustic  potash  on  alcohol, 
of  bromine  and  lime  on  acetone  (Beniger, 
Amer.  J.  Phann.  63,  80);  of  oalcinm  hypo- 
chlorite and  potassium  bromide  on  acetone 
(Fromm,  Pharm.  Zeit.  39,  164),  and  by  the 
action  of  alkahs  on  bromaL  It  has  been  made 
electrolytically  from  potassium  bromide  and 
alcohol  (Fabrik  vom  Sobering,  D.  R.  P.  29771) ; 
from  potassium  bromide  and  acetone  (Coughlin, 
Amer.  Chem.  J.  27,  63 ;  and  Muller  and  Loebe, 
Zeit  Elektrochem.  10,  409),  and  from  calcium 
bromide,  alcohol,  and  water  (Trechoinokiy  C3ienL 
Zentr.  1907,  L  13). 

Properties. — ^It  is,  when  pure,  a  oolooriess 
liquid,  solidifying  at  2*5°  and  boiling  with  slight 
decomposition  at  146°  under  751  mm.  (Wolff 
and  Schwabe,  Annalen,  291,  241),  at  151°/7e0 
mm.  (Thorpe,  CheuL  Soc.  Trans.  37,  1S80» 
201.  Sp.gr.  2-902,  16°/15°  (Perkin,  Chem. 
Soc.  Trans.  45,  533);  2*8119,  8*6°/8-5°  (Thcurpe, 
loc.  cU.).  It  is  decomposed  by  pota^  into 
potassium  bromide,  hydrogen  bromide,  and 
carbon  monoxide,  and  may  be  estimated  by 
means  of  this  decomposition  (Peegrez,  Compt. 
rend.  125,  780,  and  Annalen  23,  76;  and 
Riohaud,  J.  Pharm.  Chim.  1899,  232).  Under 
the  influence  of  light  and  air  it  decomposes, 
the  decomposition  products  depending  on  the 
time  of  exposure  and  the  amount  of  available 
oxygen  (Schoorl  and  Van  den  Berg,  Cheni. 
Zentr.  1906,  L  441).  It  has  been  used  to  a  slight 
extent  as  an  anjBSthetic,  snd  in  the  treatment  of 
diphtheria.  Bromoform  in  water,  to  which  a 
little  alcohol  has  been  added,  has  been  success- 
fully used  in  cases  of  whooping-coush  compli- 
cated with  pneumonia  (Stepp  and  GoHschmidt^ 
J.  Soc.  Chem.  Ind.  1890,  213). 

BROMOOUDINE,  BROMOGLUTEH,  BRO- 
MOPROTEIN.  Preparations  of  wheat  gluten 
or  vegetable  albumm  containing  bromine  used 
as  substitute  for  alkaline  bromides. 

BROMOL,  BROMOLEIN,  BROMOTAM  «. 
S  Y  If THiriio  Dbugs. 

BROMURAL.  Trade  name  for  a-monobrom' 
iBOvalerylurea.  Employed^as  a  hypnotic  Forms 
white  needles,  slightlv  bitter  in  taste ;  readily 
soluble  in  hot  water,  alcohol,  and  ether,  spaang^r 
soluble  in  cold  water ;   m.p.  147°. 

BRi)NllER*S   ACID,    2-Naphthylamine-6- 
sulphonio  acid  v.  Nafhthalbnb. 

BRONZE  V.  TiK. 

BRONZE  POWDERS.  Bronze  powders  am 
composed  of  copper,  udo^  tin*  and  antimony, 
melted  together  in  the  requisite  proportions. 


BROOM  TOPS. 


69S 


in  th3  prooeas  of  manafaoture,  the  alloy  is  oast  | 
into  rods  i  inoh  in  diameter  and  3  feet  long. 
These  are  rolled  until  about  2  inches  wide,  and 
then  out  into  lengths  suitable  for  handling.  The 
pieces  are  hammered  out  thin,  and  deimsed  by 
immersion  in  dilute  sulphuric  add.  The  dried 
mi&terial  is  then  beaten  out  by  steam-hammers 
until  the  limit  ol  thickness  is  reached,  when  it  is 
cut  up  hy  shews  into  small  particles  or  *  clip- 
pings.' Tiiese  are  then  pulverised  in  stamp  millB, 
and  the  powder  sifted,  to  separate  the  heavier 
and  better  quality  powder  from  inferior  material. 
The  latter  is  mixed  with  quartz  powder  and 
sold  very  cheaply  (J.  Soc.  Ghem.  Ind.  1893,  12, 
475). 

The  expense  of  the  above  process  lies  mainly 
in  the  jNroduotion  of  *  clippings,'  which  necessi- 
tates a  great  deal  of  handwork,  and  a  number  of 
methods  have  been  patented  for  reducing  the 
alloy  to  a  finely  divided  state  bv  mechanical 
means.  According  to  one  method,  the  molten 
alloy  is  rained  into  a  sheet-iron  chamber,  in 
which  a  shaft  carryinj;  blades  is  rapidly  rotated, 
BO  as  to  greatly  agitate  the  air  and  thereby 
minutely  subdivide  the  metal  at  the  moment  of 
soUdification  (Ft.  Pat.  331371,  1003).  In 
another,  the  molten  metal  flows  in  a  thin  film 
into  a  receptacle,  where  it  meets  a  current  of 
compressed  air  or  else  a  jet  of  water,  the  object 
being  to  produce  bronze  foil  or  leaves  (Eng. 
Pat.  0064,  1903).  Methods  have  also  been 
patented  for  casting  the  metal  in  thin  films  on 
the  inner  surface  ci  a  rotating  hollow  cylinder 
or  in  the  annular  space  between  two  rotating 
cylinders  (J.  Soc.  Chem.  Ind.  1903,  22, 160 ;  Fr. 
Fat.  335112,  1903). 

After  the  powdered  metal  has  been  sifted, 
the  coarser  gprades  are  polished  in  a  dosed  steel 
cylinder,  in  which  sted  wire  brushes  rub  against 
the  walls.  When  it  is  necessary  to  reduce  the 
powder  to  a  finer  state  of  division,  it  is  rubbed 
with  gum-arabic  solution,  washed  and  dried  at 
the  lowest  possible  temperature. 

Zinc-dust  is  frequently  coated  with  brass  by 
simple  immersion  in  a  copper  and  zinc  cyanide 
solution,  the  powder  bemg  kept  aeitated  by 
means  of  brushes  (J.  Soc.  Chem.  In<L  1894,  }3, 
893,  958);  the  pitxluct  is  treated  finally  in  a 
polishing  mill,  and  used  as  a  bronze  powder. 

Bronze  powders  have  also  been  described 
containing  5-10  p.c.  of  aluminium,  and  0*05- 
0*1  p.c.  of  bismuth.  The  shade  of  colour  is 
altered  by  varying  thejwrcentage  of  aluminium, 
and  by  heating  in  air  (D.  B.  P.  44242,  1887). 

Few  analyses  of  bronze  powders  have  been 
published  (J.  Soc  Chem.  Ind.  1910,  29,  1062). 
^  Gold'  and  '  bronze '  powders  were  found  to 
contain  70-85  p.c.  of  copper,  and  30-15  p.c..of 
zinc,  together  with  small  amounts  of  lead,  tin, 
arsenic,  iron,  and  aluminium  ;  *  aluminium  ' 
powders  consist  of  nearly  pure  aluminium ;  and 
silver'  powders  contain  77  p.c  of  zinc  and 
21*5  p.c.  of  aluminium. 

Bronze  powders  are  coloured  in  various  ways. 
One  method  consists  in  heating  the  powder  in 
an  open  yessd  with  oil  and  vinegar,  or  with 
wax,  paraffin,  or  oils  containing  sulphur. 
Buchner's  process  consists  in  shaking  the  powder 
in  a  dosed  vessel  with  hydrogen  sulphide  solu- 
tion, allovring  to  stand  24  hours,  drying  and 
heating  in  an  ofl-bath  until  sufficiently  coloured 
(J.  Soo.  Chem.  Ind.  1806,  15,  283).    Artificial 


dyestufis  are   also  used  for  colourine  bronzi^. 
powders. 

The  following  are  examples : — 


Ooloar  of 
powder 

MetaUlo 
oonstltoents 

Total 
organic 
matter 

Cdoorlng 
matter 

Pink   . 

Blue    . 

Copper  ooloar 
Violet. 

Pale  green   . 

Olive  green  . 

Copper 

Tin  and  sine 

Copper  (little  sine) 
Tin  (little  copper) 

Copper  and  sine 

Copper  and  sine 

0*8  P.O. 
8-8  „ 

5-6  „ 
8*8  „ 

4-8  ,. 

5-9  „ 

Axtne  scarlet 

0 
YlctorU  blue 

4B, 

Fast  neutral 

violet  B 
Malachite 

green 
BrlUlant 

green 

Bronze  powders  are  used  considerably  for 
printing  on  textile  fabrics.  For  this  purpose, 
they  must  be  mixed  with  a  *  fixer  *  which  allows 
the  powder  to  be  readily  applied  to  the  material, 
whilst  so  fixing  it  that  brushing  will  not  remove 
it ;  the  fixer  must  not,  of  course,  interfere  with 
the  brilliancy  of  the  powder.  Two  classes  of 
'  fixers '  are  in  use,  eg^  or  blood  albumen,  and 
various  varnishes  having  caoutchouc  as  their 
base.  In  printing  such  eoods,  the  main  point 
to  be  obseryed  is  that  the  impression  shall  be 
sharp,  and  applied  with  sufficient  force  to 
prevent  the  particular  fibres  from  ^g^  risins. 
(For  further  particulars,  v.  J.  Soc  Chem.  Ind. 
1896,  15,  283  ;  1900,  19,  243  ;  1906,  25,  1040  ; 
and  for  various  bronze  powder  substitutes,  v, 
ibid.  1896,  15,  284.) 

BROOKITE  V.  TiTAirinM, 

BROOM  TOPS.  Scoparii  cacumina  B.P. 
Scaparitis,  U.S.  Pat.  was  deleted  in  1916,  but 
Sparteines  stUphas  is  retained.  {Oen&  d  balais. 
Ft.  ;  Besenginater,  Ger.).  The  tops  of  the 
common  broom,  Cytis-ua  acopariua,  Link= 
Spartium  scoparinm,  L.  (BentL  a.  Trim.  70),  have 
been  employed  for  their  diuretic  action  since  the 
Anglo-Saxon  period,  and  are  noticed  in  nearly 
all  the  herbals  and  pharmacopoeias  (Planta 
genista).  The  main  constituents  are  sparteine 
and  scoparin. 

Sparteine  Ci5H,,N„  a  liquid  alkaloid  (Sten- 
house,  Annalen,  1851,  78,  15 ;  Mills,  ibid.  1863, 
125,  71) ;  subsequently  shown  to  be  identical 
with  lupinidine  from  yellow  lupin  seeds  {L.  ItUcus) 
by  Willstatter  and  Man  (Ber.  1904,  37,  2351). 
It  may  be  obtained  from  broom  tops  by  extrac- 
tion with  yery  dilate  sulphuric  acid,  concentra- 
tion of  the  extract  and  steam-distillation  of  the 
residue,  after  addition  of  alkali.  The  crude 
alkaloid  may  be  purified  by  distillation  in  a 
current  of  hydrogen. 

Properties.  A  colourless  liquid,  sp.gr.  1*034 
at  O"",  b.p.  188**  under  18*5  mm.,  or  325"*  in  a 
current  of  hydrogen  under  754  mm.  pressure 
(Moureu  and  Valeur,  Compt.  rend.  1903,  137, 
194),  180*5''  under  18  mm.  (W.  and  M.  Z.c.). 
Slightly  soluble  in  water,  soluble  in  alcohol, 
ether,  or  chloroform ;  insoluble  in  light  petro- 
leum or  benzene.  The  aqueous  solution  is  alka- 
line and  yery  bitter,     [ol  =— 14*6®  in  alcohol 

(Bamberger,  Annalen,  1886,  235,  368),  —16-42*' 
(M.  and  v.  l.c.)  at  20^.  Sparteine  is  a  diacidic 
base,  which  forms  difficultly  crystallisable  salts. 
The  alkaloid  and  its  salts  are  toxic 


606 


BROOM   TOPS. 


Readiona  and  coruMuUan*  Sparteine  be- 
haves towards  alkyl  iodides  as  a  ditertiary 
base,  but  contains  no  methyl  linked  to  N 
(Herzig  and  Meyer,  Monatsh.  1894,  16,  613 ; 
1895,  16,  599  ;  M.  and  V.  l.c.).  It  furnishes  no 
reduction  products,  and  is  unaffected  by  per- 
map|;anate.  Sparteine  reacts  with  methyl 
iodi<&  to  form  two  monomethiodides,  which  are 
regarded  as  stereoisomerides.  On  *  exhaustive 
methylation '  sparteine  furnishes  hemispartei- 
lene  CigH^tN  and  trimethylamine  and  finally 
sparteilene  CnHto*  On  oxidation  with  chromic 
acid  it  yields  q>artyrine  Ci^Ht^N.,  and  eventu- 
ally oxy sparteine  CigH|40N|.  With  hydroeeQ 
peroxide  dioxysparteine  CxgH.cOsNg  resiuts, 
presumably  a  di-ammonium  oxide.  From  these 
and  other  data  Moureu  and  Valeur  (Ck)mpt.  rend. 
1905,  141,  261,  328)  have  assigned  the  following 
formula  to  sparteine — 

CH, CH,       CH,-— -CH, 


N-CHj-CH.-CH  CH-CH,CH,-N 


CH,- 


■CHCH,- 


CH- 
Sparteine. 


CH, 


The  .principal  papers  relating  to  sparteine  are  as 
follows :  Ahrens,  Ber.  1887,  20,  2218 ;  1888, 21, 
825 ;  1891,  24,  1095 ;  1892,  25,  3607 ;  1893, 
26,  3035 ;  1897,  30,  195 ;  Mouieu  and  Valeur, 
Compt.  rend.  1903,  137,  194;  1905,  140,  1601, 
1645 ;  141,  49,  117,  201,  328 ;  1907,  145,  815. 
929, 1184, 1343  ;  1908  ;  146,  79  ;  1911, 152, 386, 
527 ;  1912,  154,  309 ;  Bull  Soc.  chim.  1909, 
[iv.]  5,  31,  37,  40 ;  and  r^umd  Ann.  Chim. 
Phys.  1912  [viiL]  ?7, 246-391 ;  Wackemagel  and 
Wolffenstein,  Ber  1904.  37,  3238 ;  Wil&tatter 
and  collaborators,  ibid.  1904, 37, 2351 ;  1905, 38, 
1772. 

For  the  salts,  see  Bambeiger  {Lc)  and 
Corriez  (Bull  Sci  Pharmacol  1912, 19, 468,  527, 
533,  602).  The  sulphate  C„H„N„  H,304, 
6H,0  is  official  in  the  U.S.P.,  andiorms  hygro- 
scopic crystals  becoming  anhydrous  ut  100^  and 
melting  at  153''.  Crystals  with  3  and  with 
8H,0  have  also  been  described.  The  salt  is 
soluble  in  about  an  equal  weight  of  water,  less 
so  in  alcohoL  It  has  been  recommended  as  a 
cardiac  stimulant,  but  its  action  on  the  heart  is 
doubtfuL  Sparteine  is  much  less  poisonous 
than  coniine,  which  it  resembles  to  some  extent 
in  action;  it'  also  resembles  nicotine.  For 
colour  reactions  of  sparteine,  «ee  Reichard(Pharm. 
Zentr-H.  1906,  48,  386).  The  amount  present 
in  broom  tops  varies  considerably  with  the 
season  of  the  year.  There  is  a  well-defined 
maximum  in  March  and  minimum  in  August 
(Carr  and  Reynolds,  Pharm.  J.  1908  [iv.]  26, 
542 ;  Chevalier,  Compt.  rend.  1910,  160,  1068). 
The  former  authors  found  0*07  to  1*06  p.c. 
in  commercial  specimens,  and  in  specimens 
from  the  same  locality  0*53  p.c.  in  March, 
0*07  p.c.  in  August.  Chevidier  states  that  the 
alkaloid  wanders  into  the  fruit  in  the  following 
season,  mature  seeds  containing  1*1  p.c.  Valeur 
(Compt.  rend.  1917, 164, 818)  has  based  a  method 
for  the  estimation  on  the  decrease  of  solubility  in 
water  of  the  free  base  with  rise  of  temperature. 

Seoparin  C,oH,oOi„5H,0,  m.p.  202''-219'' 
(aooording  to  the  rate  of  heating),  is  a  pale  yellow 
powder  separating  from  the  aqueous  decoction 
as  a  jelly  and  crystallising  with  difficulty  from 


alcohoL  The  formula  may  be  reeolved  into 
C,H,-OMe(4)OH(3)-Ci,H«0,(OH)^  the  un- 
resolved  portion  yielding  phlorpgludnol  on 
potash  fusion,  and  probably  containing  a  pyrone 
ring  (Goldschmiedt  and  von  Hemmeunayr, 
Monatsh.  1893,  14,  212 ;  1894,  15,  360 ;  A.  G. 
Perkin,  Chem.  Soc.  Trans.  1900,  77,  422). 
Scoparin  dissolves  slightly  in  water,  readily  in 
alkalis,  e.g,  in  ammonia  with  a  deep  yellow- 
green  colour.  With  ferric  chloride  it  giyes 
a  violet-blue  colour,  rapidly  becoming  dark- 
brown ;  it  reduces  Fehling*s  solution.  Heated 
with  alcohol  lees  soluble  isoecoparin,  m.p.  235**, 
is  formed,  which  on  solution  in  alkalis  and  re- 
precipitation  is  reconverted  into  soopaiin. 
Dcojparin  is  stated  to  be  the  cause  of  the  diuretic 
action  of  broom  tops.  G.  B. 

BROPHENIN.  Brom-t«o- vaieiylamino  acet- 
p-phenetjdin. 

^^  BROSIMUII  GALACTODENDROM  (Don). 
The  latex  of  this  urticaoeous  tree  (oow-tiee,  milk- 
tree),  growing  in  Venecnela,  approximates  to 
oow*s  milk  in  composition.  It  contains  35-2  p.o. 
of  wax  and  sajponifiable  matten,  which  are  used 
in  the  manufacture  of  Cr^ndtBs  (Booatininult, 
Pharm.  J.  [3]  9,  679). 

BROUSSONETIA  PAPTRIFERA  (Vent). 
The  Paper  muibernf.  The  fibrous  bark  is  used 
in  China  and  Japan  for  the  manufacture  of  a 
kind  of  paper,  and  in  Polynesia  in  the  manu- 
f aoture  of  Tapa  cloth. 

BROVALOL.    The  bomeol  ester  of  a-bromo 
isovalerianic  acid  C^HjBr.OoOCioH,,. 

BROWN,  ACID,  V.  Azo-ooloubiko  mattsbs. 

BROWN,  ANIUNB ;  BISMARCK  BROWN, 
HANCHESTER  BROWN,  PHSNTLBHB 
BROWN,  VESUVINE,  LEATHER  BROWN, 
CINNAMON  BROWN,  ENGLISH  BROWN,  or 
GOLD  BROWN ;  v.  Ago-  ooLOUBoro  KAnsBS. 

BROWN,  ANTWERP,  v.  Piombxtb. 

BROWN,  ARCHIL,  v.  Aco-  ooLOUBoro  mat- 


BROWN,  BONE,  o.  PionBTS. 

BROWN,  CALEDONIAN,  v.  Piombbtb. 

BROWN,  CAPHEK,  v.  Piombmis. 

BROWN,  FAST,  v.  Azo-  coloubiko  mattbbs. 

BROWN,  FUSCANINE,  v.  Ahinofhbhol. 

BROWN,  GARNET.  The  potassium  or  am- 
monium salt  of  wopurpuric  acid  (CfH^N^O^K  or 
C,H,N,0.).  ObUined  by  Hlasiwets  in  1859  by 
the  action  of  potassium  cyanide  on  picric  acid 
(Annalen,  110,  289).  Forms  a  dark-brown 
powder,  readilv  soluble  in  hot  water  with  red- 
dish-brown colour.  Dyes  wool  and  silk  brown 
in  an  acid- bath.      No  longer  is  use   (v.  also 

ISOPUBPUBIO  AdD). 

BROWN,  MADDER,  v.  Piombhts. 
BROWN,    NAPHTHYLAMINE,     o.      Aio- 

COLOUBDIO  MATTBBS. 

BROWN,  PHENYL,  v.  Phbktl  bbowv. 
BROWN,  PICRYL,  v.  Piobtl  bbowv. 
BROWN,   PIGMENT,    v.    Azo-    ooloubdio 


PRUSSIAN,  V,  Piombxtb. 
RESORCIN,  V.   Azo-  ooloubuto 

SOUDAN,    V.   Azo-    ooLoirBuio 

VANDYKE,  V.  Piombbtb. 
VERONA,  V.  Piombhts. 
BERRIES.    The   fruit   of    Rybv* 


BROWN, 
BROWN, 

MATTBBS. 

BROWN, 

MATTBBS. 

BROWN, 
BROWN, 
BROWN 

Jrutieosus. 


BDCHU  OR  BUCCO. 


607 


BROWN  COAL  v.  Fuel. 

BROWN  H^EMATITB  v.  I&oK,  Ores  of. 

BROWN  IRON  ORE  (Limanite)  v.  Ibon, 
Obis  of. 

BRUCINE  V.  Nvx  Vomioa. 

BRUQTE.  Native  magnesiain  hydroxide, 
Mg(OH)|,  found  as  platy  oiystals  with  perfect 
micaoeooB  oieayage,  or  as  lameitar  masses,  in 
serpentine  rocks,  at  Unst,  one  of  the  Shetland 
Isles,  at  Texas  in  Pennsylvania,  &o.  It  some- 
times contains  a  small. amount  of  iron  (ferro- 
bnicite)  or  manganese  (manganbmcite).  A 
fibrous  variety  is  called  nemalite.         L.  J.  8. 

BRUNSmCK  BLACK  is  prepared  by  fosing 
2  lbs.  of  asphalt,  and  mixing  thorouffluy  with 
1  pint  of  hot  boiled  oil.  When  cool,  2  pints 
of  turpentine  are  added  to  the  mixture.  An 
inferior  but  cheaper  black  may  be  mode  by 


boiling  gently  together  for  five  hours  25  lbs. 
each  of  black  pitch  and  oas  tar  asphaltumi 
8  gallons  of  linseed  oil,  and  10  lbs.  each  of  litharge 


and  red  lead  are  then  mixed  in,  and  the  whole 
boiled.  After  cooling,  the  mixture  is  thinned  by 
the  addition  of  20  gallons  of  turpentine  (v.  also 
Bon  OIL). 

BRUNSWICK  GREEN.  An  oxychloride  of 
copper,  used  as  a  pigment.  Copper  filings  or 
turnings  are  moisteuMl  with  a  solution  of  sal* 
ammoniac,  and  left  in  contact  with  the  air ;  the 
oxychloride  so  formed  is  washed  off  with  water, 
and  dried  at  a  gentle  heat.  The  term  is  also  ap- 
plied to  chrome  green  and  to  emerald  green 
(o.  CorPEB  and  Piqmsxts). 

BRUSHITE.  A  hydiated  phosphate  of  lime, 
HCaP04,2H,0,  occurring  in  Uie  guano  of  Aves 
Island  and  Sombrero  in  the  Caribbean  Sea. 

BRUSSELS  SPROUTS.  A  variety  of  the 
cabbage  {Brcusica  oleracea),  in  which  numerous 
small  heads  are  developed  along  the  stalk  from 
the  axils  of  the  leaves,  instead  of  one  terminal 
head. 

The  edible  portion  contains,  according  to 
American  analyses : 

Water      Protein      Fat    Carbohydrates   Ash 
88-2  4-7        1-1  4-3  1-7 


{see  Cabbaos). 


H.  I. 


BRYOIDIN  t\  OLEO-BBsms. 

BRYONY  ROOT.  Bryony  root  has  been  used 
medicinally  from  a  v^ery  remote  period  on 
account  of  its  cathartic  properties,  and  was 
formerly  recognised  by  several  of  the  national 
Pharmacopoeias,  but  is  now  rarely  employed. 
The  plants  yielding  this  root  are  Bryonia  alba, 
Limie,  and  Bryonia  dioica,  Linn6  (Nat.  Ord. 
Curcurbitacee),  which  are  botanically  closely 
allied.  They  are  indigenous  to'  the  greater 
part  of  Europe,  but  the  mst-named  species  is  the 
only  one  of  the  genus  commonly  found  in  this 
country,  and,  therefore,  is  frequently  designated 
as  English  bryony.  The  roots  of  the  two 
species  are  generally  considered  to  possess  the 
same  properties,  and  they  appear  to  be  indis- 
criminately collected,  although  it  has  been 
asserted  by  Petresco  (United  States  Dispensa- 
tory, 18th  ed.,  p.  279)  that  they  differ  apjueciably 
in  their  physiological  action.  The  roots  of 
Bryonia  dtoica  contain  an  enzyme  as  a  light- 
brown  powder,  which  slowly  hydrolyses  the 
fflucoside  in  the  root»  and  also  effects  the  hydro- 
jysifi  of  amygdalin  and  salicin.  The  alcoholic 
•extract  of  the  dried  root  yields  a  pale  yellow 


essential  oil  of  characteristic  odour ;  a  colourless 
crystalline  neutral  substance,  Cs«H,oOs  (m.p. 
220''-222''}  [a]  +58*6'' ;  an  amorphous  glucoside 

of  a  brown  colour  and  bitter  taste,  which  on 
hydrolysis  yields  a  brown  resin,  and  a  sugar 
formiog  c^-phenylglucoeazone  (m.p.  208*'-210^) ; 
an  amorphous  a&Laloidal  principle,  brownish- 
yellow  in  colour,  and  of  an  intensely  bitter  taste. 


,     _^ „  yielding  a  diacetyl 

(m.p.  162**) ;  (iii)  a  mixture  of  fatty  acids, 
consisting  of  oleic,  linolic,  palmitiCf  and  stearic 
acids.  Bryonol  appears  to  oelong  to  a  group  of 
dihydric  alcohols  of  the  general  formula 
nHa^gO^,    comprising :     ipurgancl 

C,iHg,0,(OH), 

grinddol  Ct^EL^OtiOIL)^,  and  eurcufbiUd 
^a«HM0a(0H)2.  The  bryonin  of  previous  in- 
vestigators consisted  of  complex  mixtures.  The 
activity  of  bryony  root  Cannot  be  atrributed  to  a 
single  definite  principle,  its  purgative  property 
resides  chiefly  in  its  resinous  and  alkaloidal 
constituents   (Power  and  Moore,   Chem.   Soo. 

Trans.  1911.  99.  937).    ,         ,     ^ 

BUBUUN  (nom  fiois,  ox).  The  name  of  » 
peculiar  substance,  said  by  Morin  to  exist  in  cow- 
dung,  and  to  be  {vrecipitated  bv  metallic  salts, 
tincture  of  galls,  and  alum,  and  therefore  to  be 
active  in  the  application  of  cow-dung  to  calico- 
printing. 

BUCHU  V,  OnjB,  Essxntul. 

BUCHU  or  BUCCO.  The  leaves  of  three 
varieties  of  Baroama  (ord.  Butaceje),  viz.  B, 
hettdina  (Bartl  et  Wendl.  f.),  B.  crenvlata (Hook.), 
and  B.  serraUfolia  (Willd.),  are  known  under  this 
name.  The  leaves  are  used  medicinally  by  the 
South  African  natives. 

Their  composition  has  been  studied  by 
Brandos  (Arch.  d.  N.  Apoth.  Ver.  22,  229), 
Landerer  (Buchner's  Repert.  84,  63.,  Fluckiger 
(Pharm.  J.  3,  4,  689 ;  [3]  11,  219),  Wayne  {ibid. 
3,  6,  723).  By  extracting  the  leaves  with  light 
petroleum,  Bialobizeski  (Chem.  Zentr.  1896,  iU 
651)  obtained  chlorophyll,  a  resin,  and  an 
ethereal  oil  containing  chieliy  diosphenol, 
together  with  a  terpene  CjoH,  g,  b.p.  174  -176°, 
and  a  ketone  isomeric  with  menthone,  and 
having  the  constitution  CmHigO,  b.p.  206**- 
209°  ;  it  yields  an  oxime  and  a  tribrom  deriva- 
tive. After  extraction  with  light  petroleum,, 
the  leaves,  on  treatment  with  cold  alcohol,, 
yield  3  p.c.  of  a  brownish-fltreen  bitter  resin 
insoluble  in  benzene,  and  when  the  alcohoUo 
extract  is  treated  with  sodium  carbonate  or 
by  other  methods  diosmin  is  deposited,  forming 
tasteless,  odourless  crystals,  m.p.  244°. 

Semmler  and  Mckenzie  (Ber.  1906,  1168) 
found  that  the  round  leaves  of  Baroama  beitdtTia 
yield  about  2  p.c.  of  an  oil  which  crvstallises  on 
standing  at  ordinary  temperature ;  but  the  lonR 
leaves  of  Barosma  aerralijolia  yisHd  1  p.c.  ol  an 
oil  which  remains  liquid  under  similar  conditions. 

According  to  K^ondakoff  and  Bochtschiew 
(J.  pr.  Chem.  1901,  63,  49),  the  best  oU  of 
bucco  or  buchu  leaves  contains  10  p.c.  of 
hydrocarbons,  consisting  of  a  variety  of  d- 
limonene  and  dipentene;  60  p.c.  of  a  ketone 
C,.H„0,  [«]„.  -16°6'.  b.p.  208.6' -  209-6*. 
which,  on  reduction,  yioldB  a  menthol  not  identi- 
cal with  the  natural  product ;  20  p.c.  of  dios- 


698 


BUOHU  OR   BUCXX). 


phenol ;  5  p.o.  of  resin ;  and  5  p.o.  of  other  i 
constituents  (KondakoS,  J.  pr.  Chem.  1806, 
54,  433).  After  removing  diosphenol  from  the 
oil  of  buchu  leayesy  Tsohugsoff  succeeded  in 
obtaining  xanthogenide  derivatives  of  d-menthol 
from  a  fraction  of  the  residue  (J.  Russ.  Phys. 
ChenL  8oc.  1910,  42,  714;  Skovortsoff,  ibid. 
ii.  56).  Diosphenol  or  buchn  camphor  (Bialo- 
brzesid,  l.c ;  Kondakoff,  Lc ;  Semmler  and 
McKenzie,  he. ;  SemmJer,  Chem.  Zeit.  1906, 
30,  1208;  Kondakoff,  Chem.  Zentr.  1906,  ii 
1252 ;  Chem.  Zeit  1906, 1090,  1100)  is  optically 
inactive,  has  m.p.  82^,  b.p.  lOO^'-l  10^/10  mm., 
232^756  mm.  Its  composition  is  probably 
CjoHjfOf  It  IS  a  phenolic  aldehyde,  yielding 
an  ozime,  m.p.  156^  (Semmler  and  MoKenzie 
125^).  With  hydrochloric  acid  it  yields  thymol 
and  a  little  carvacroL  With  hydriodic  acid  it 
yields  a  hydrocarbon  CioH^o,  b.D.  165''-1687762 
nmi.;  whilst  with  sodium  in  alcoholic  solutioa 
it  forms  (1)  a  menthol ;  (2)  a  crystalline  glycol 
GtoH,,(OH)a  m.p.,  92®;  and  (3)  an  isomeric 
glycol,  b.p.  141-5''-145713  mm.  With  akK>- 
holio  potash,  a  hydroxy  acid  of  the  terpene 
series,  m.p.  94**,  is  obtained.  This  acid  has  been 
synthesised,  and  is  identical  with  the  natural 
product.  The  dibromide  C«oHi40|Brt  and 
other  derivatives  of  diosphenol  have  also  been 
obtained. 

BUCKTHORN  (Rhamnua  catharHca  [Linn.]). 
This  plant  ia  a  native  of  England ;  it  grows 
to  a  height  of  from  15  to  20  feet ;  its  flowers 
are  greenish-coloured,  and  its  berries  four- 
seeded.  The  juice  of  these  when  in  an  unripe 
state  has  the  colour  of  saffron;  when  ripe 
and  mixed  with  alum,  it  forms  the  sap  or 
bladder-green  of  the  painters  (v.  Piomxitts)  ;  and 
in  a  very  ripe  state  the  berries  afford  a  purple 
colour.  The  bask  also  yields  a  fine  yellow 
dye. 

The  berries  of  the  Bhamnus  cariharUea  (also 
known  as  Hungarian  berries)  have  been  examined 
by  Tschirch  and  Polacco  (Arch.  Pharm.  1900, 
238,  409),  and  evidently  contain  substances 
chemicaUy  distinct  from  those  which  are  present 
in  Peisian  berries. 

Ether  extracts  from  an  aqueous  extract  of 
the  berries  rJuunnocitrin,  rhamnohtHn,  rhantno- 
chryein,  and  the  residual  watery  liquid  on  boiling 
witn  dilute  sulphuric  acid  gives,  m  addition  to 
rhamnocitrin,  fi-rhamnocitrin.  The  berries  al- 
ready extracted  with  water  contain  rhamno 
emodin  and  rhamnonigrin. 

Bhamnocitrin  Ci,H,oO.,  yellow  needles,  melts 
at  221^-222®,  and  is  soluble  in  alkaline  solutions, 
with  a  yellow  colour.  Alcoholic  lead  acetate 
gives  an  organic  coloiured  precipitate,  and^  ferric 
chloride  a  green  colouration.  The  solution  in 
sulphuric  acid  possesses  an  intense  green 
fluorescence. 

TriacelylrhamnoeiinnCi  ,H70,(GaH,0)tf  orms 
colourless  needles,  meltinfc  at  199^-200®. 

Rhamnocitrin  appears  to  bo  a  dihydroirihy' 
droxyxanihofu,  and  probably  possesses  the  follow- 
ing constitution : — 

Qjj       O         OH 

OH  ^ 


It  dyes  with  iron  mordant  a  green- brown,  and 
with  aluminium  mordant  a  bright-yellow  colour. 

WiamnoluUn  Ct^H.oO.,  small  canary-yellow 
needles,  melts  above  Z60^  and  gives  with  lead 
acetate  an  orange-red  precipitate,  with  ferric 
chloride  a  green-black  colouration.  Its  sulphuric 
acid  solution  posseses  a  strong  green  fluorescence. 
TeiraacetylrhamnoluUn  (},  .H«0.(C,H,0)4,  colour- 
less  needles,  melts  at  182^-183''. 

Rhamnolutin  dyes  aluminium-  and  iron- 
mordanted  fabrics  respectively  canary-yellow 
and  green-brown  shades.  It  appears  to  be  a 
tetrahydroxyfiavone,  isomeric  witn  luteolin  and 
fisetin. 

fi-Rhamnocitrin  0,aH,^0.  is  sparingly  soluble 
in  alcohol  and  acetic  acid,  out  is  distinct  from 
rhamnetin  (CitHxoO,  ?),  and  does  not  contain 
methoxy-  groups.  It  melts  above  260®,  and, 
general^  speaking,  its  reactions  are  the  same  as 
those  of  rhamnocitrin  itself,  but,  on  the  othet 
hand,  it  possesses  strongei  dyeing  property. 
Diacetyl-fi-rhamnocibrin  0,  ,H,0«(CtH,0)a  lorms 
odourless  needles  melting  at  190*- 191^ 

/S-Rhamnocitrin,  according  to  Tsohiroh  and 
Polacco,  appears  to  reeemble  very  oloaely  the 
iS-rhamnetrin  of   Schutzenberget  (me  FnsiAa 


). 
Rhamnoemodin  C,tH.qO.,   m.p.    264''~266^ 

is  similar  to  franguia  tmotUn  {B.  frangula)  wliieh, 

according  to  Oesterle,  melts  at  250*. 

Bhamnonigrin  is  converted  by  boiling  with 
nitric  acid  into  chryMmminio  add^  and  by 
digestion  with  boiling  alcohoUo  potash  into 
emodin* 

The  alder  bnekthoni  (Bkamnua  fra$igula) 
grows  naturally,  and  is  very  abundant  in  woods 
and  thickets,  in  some  parts  of  Britain.  The 
berries  of  this  species  are  often  substituted  for 
those  of  tiie  above ;  but  they  are  easily  detected, 
since  they  contain  only  two  seeds.  In  a  green 
state  they  dye  wool  green  and  yellow ;  when 
ripe,  bluish-grey,  blue,  and  green.  The  bark  also 
dyes  yellow,  and,  with  preparation  of  iron*  black 
(Lawson) 

Roek  baekthom  {Bhamniu  $axaliUM\  yields 
berries  which  are  used  to  dye  morocco  leathet 
yellow.  These,  in  common  with  the  narrow- 
leaved  buckthorn  berries  (iS.  alatemue  [Linn.]) 
and  those  of  the  yellow-berried  buckthorn  {B. 
infecioriua  [Lhin.]),  are  sold  as  Avignon  bernes. 
The  wood  of  the  Bhamnue  erythroxyUm  (which 
is  a  native  of  Siberia,-  but  ^ws  freely  in  this 
climate),  in  a  ground  state  jields  the  bright- red 
colour  known  to  dyers  ondei  the  name  of 
redtoood.        A.  0.  P. 

BUCK  WHEAT  {Fagopyrum  eacvlenhtm 
fMoonch.])  is  grown  mainly  for  poultry  and  also 
for  pig-  and  cow-feeding  in  Europe.  Its  flowers 
furniBn  excellent  pasturage  for  oees.  Kellner 
gives  the  smalyses  on  opposite  page. 

Buckwheat,  after  soaking  in  water,  furnishes 
excellent  food  for  cattle  and  pigs,  though  not 
very  suitable  for  young  animais. 

The  globulin  of  buckwheat  has  the  composi- 
tion :  0  51-69,  H  6-90,  N  17*44,  8  M6,  and 
0  22*81.  It  contains  about  13  p.c.  aiginine, 
0*6  lustidine,  7*9  lysine,  and  1  p.c  cystein  and  a 
small  amount  of  tryptophan  (Johns  and 
Ohemoff,  J.  BioL  Chem.  1918,  34,  439). 

The  starch  of  buckwheat  occurs  in  rounded 
angular  grains  of  small  size,  showing  a  distinct 
hilum  and  a  tendency  to  agglomeratew 


BUILDING  STONE. 


«90 


Seed    . 
Fine  meal 
Goane  meal 
Fine  bran 
OockTse  bran 
Husks. 
Straw  . 
Whole  plant,  in  flower 
hay  . 


M 


»» 


Water 

• 

Protein 

Fat 

Carbo- 
hydrates 

Fibre 

Ash 

141 

11-3 

2-6 

64*8 

14-4 

2-8 

14-7 

8-6 

1-9 

72-6 

0-8 

1-4 

120 

31-8 

8-4 

38-3 

4-8 

4-7 

12-0 

16*2 

4-5 

60-0 

11-3 

7-0 

16-6 

80 

1-6 

34*2 

37-6 

2-8 

13-2 

4-6 

1-1 

36*4 

43-5 

2-2 

16-0 

4-8 

1-2 

34-6 

38-2 

6-2 

83-7 

2-5 

0-6 

7-8 

4*3 

M 

14-0 

10-5 

21 

• 

86*6 

31-4 

6*4 

The  flour  is  largely  used  in  making  buck- 
wheat cakes,  popular  in  America,  but  rarely  met 
with  in  Englandl  H.  I. 

BUCURUMANOA  BESIN.  A  fossU  resin, 
occurring  in  an  auriferous  alluvium  near  Bucuru- 
manga,  New  Granada.  It  is  light-yellow,  trans- 
'  parent,  somewhat  heavier  than  water,  becomes 
strongly  electric  by  friction ;  is  insoluble  in 
alcohol ;  swells  up  m  ether,  becoming  opaque ; 
melts  when  heated;  bums  in  the  an  without 
residue.  It  resembles  ambev  in  outward  appear- 
ance, but  does  not  ^ve  succinic  acid  on  dry 
distillation.  It  contams  82*7  p.c.  0,  10*8  p.c.  H, 
and  6*50  p.c.  0  (Boussingault,  Ann.  Chim.  Phys. 
[3]  6,  607)  (v.  BssiKs). 

BUFA6IN  V,  BuvoTALiN ;  and  Toad  vbnom. 

BUFFALO    RUBIN    v.    A20-     ooloubotg 

MATTBBS. 

BUFOTAUN,  the  poisonous  principle  of  the 
toad,  Ci,H,404, m.p.  148*  (decomp.)  WaO-fS^**, 

is  a  crystalline  neutral  substance.  AlkaU  con- 
verts it  into  the  unsaturated  hnjoUdic  acid, 
proving  bufotalin  to  be  a  lactone.  The  other 
two  oxygen  atoms  are  present  as  alcoholic 
hydrozyl  group&  It  dissolves  in  concentrated 
sulphuric  acid  with  an  orange-red  colouration 
which  becomes  deep  red  on  standing,  and  shows 
a  green  fluorescence.  Concentrated  hydrqgen 
chloride  in  the  cold  eliminates  2  mols.  of  water, 
forming  a  pale-yellow  crystalline  compound 
bufotalien  Ci«H,oO„  m.p.  219^  AcetyU 
bufoUdien  separates  in  lustrous,  yellow  platelets 
grouped  in  rosettes,  m.p.  184*  (decomp.). 

Bufotalin  is  not  identical  with  bu/agin 
^i«^a«G4,  obtained  from  the  parotoid  sland  of 
the  tropical  toad  Bufo  Agua  by  Aoel  and 
Maoht  (J.  Pharmacol  and  expt.  Ther.  1912, 
3,  319).  This  is  also  dextrorotatory  {-\-lV), 
sparingly  soluble  in  water,  m.p.  217*-218*. 
(Wieland  and  Weil,  Ber.  1913,  46,  3316). 

The  Chinese  drug  *senso,'  prepared  from 
toad  skins,  appears  to  contain  bufagin,  associated 
with  cholesterol,  together  with  adr^ialine  and 
imfotoxin,  a  member  of  the  piorotoxin  group  of 
poisons  (Shimizu,  J.  Pharm.  Expl.  Ther.  1916, 
8,  347).    V.  Toad  vbkom. 

BUHRSTONE  or  BURRSTONE.  A  hard, 
tough  rock  consistuig  of  chalcedonic  silica  with 
a  cellular  texture,  especially  suitable  for  use  as 
millstones  for  grinding  oom,  paints,  &o.  It  is 
white,  grey,  or  creamy  in  colour.  The  best 
stones  are  from  the  Tertiary  strata  of  the  Paris 
basin,  and  have  originated  by  the  silicification 
of  fresh*water  limestones,  the  cellular  spaces 
representing  the  oasts  of  fossil  shells  and  Chora 

BUILDIMO  STONB,    The  essential  quiuities 


of  a  building  stone  depend  on  its  physical 
characteiB  rather  than  on  chemical  composition. 
Nevertheless,  the  broad  classification  of  Duilding 
stones  has  a  chemical  basis,  viz. : — 

Sandstones  and  QrUSf  composed  largely  of 
silica  in  the  form  of  quartz  grams. 

Limestones  and  Marbles,  consisting  of  calcium 
carbonate,  sometimes  with  magnesium  carbonate. 

SlateSf  consisting  largely  of  secondary 
aluminium  silicates. 

Igneous  Bocks  (including  granite,  syenite, 
diorite,  gabbro,  porphyry,  porphyrite,  dolerite, 
diabase,  rhyolite,  andesite,  basalt)  composed  of  a 
dense  crystalline  aggregate  of  closely  interlocking 
grains  of  hard  silicate  minerals,  sometimes  with 
quartz. 

A  few  other  misoellaneous  rocks  used  as 
building  stones  include  flint,  serpentine,  pot- 
stone,  and  laterite.  Each  of  these  Idnds  of  rock 
is  considered  under  its  respective  heading. 

Although  a  large  number  of  analyses  of 
building  stones  are  on  record,  these  are  of  little 
direct  value  in  estimating  the  quality  of  a  stone. 
They  are,  however,  useful  in  indicating  whether 
a  limestone  is  dolomitic  {i.e.  containing  magnesia) 
or  clayey  in  character,  and  in  telling  the  nature 
of  the  cementinff  material  in  the  case  of  sand- 
stones. A  simpk  test  with  acid  is  often  useful 
in  helping  to  recognise  a  limestone,  otherwise 
there  is  usually  not  much  difficulty  in  allotting 
different  stones  to  l^eir  main  classes.  Colour 
and  change  of  colour  on  weathering  are  usually 
connected  with  the  amount  and  state  of  the  iron 
present  in  the  stone. 

In  the  decay  of  building  stones  in  buildings 
the  processes  involved  are  different  not  only  in 
degree  but  also  in  kind  from  those  which  take 
place  in  the  weathering  of  rocks  in  situ,  as 
considered  by  geologists.  Here  chemical  action 
is  in  general  of  less  importance  than  that  pro- 
duced by  mechanical  means,  especially  by  the 
action  of  frost  and  by  extreme  alternations  of 
temperature,  and  by  the  organic  action  of 
Uchens.  The  solvent  action  of  pure  rain-water 
is  insignificant  for  all  stones  except  alabaster. 
Carbonated  water  has  a  more  pronounced  solvent 
action  on  limestones  and  the  calcareous  cement 
of  sandstones.  In  the  case  of  silicate  rocks  ^  the 
action  of  carbonated  water  is  extremely  slight, 
unless  the  felspars  have  already  been  previously 
considerably  altered  by  weathering  in  situ.  In 
towns,    however,    the    action    of   sulphurous, 

^  Here  the  effect  of  alternations  of  temperature  is 
of  much  more  importajQce  owing  to  the  conjunction  of 
minerals  possessing  different  ooeffldents  of  expansion. 
In  passing  it  may  also  be  remarked  that  igneous  rocks 
(and  also  Jasper)  are  the  only  stones  used  for  outside 
decoratton  which  are  capable  of  retaining  a  lurfaos 
poliib« 


700 


BUILDING  STONE. 


sulphuric  (hydrochlorio  and  nitric)  acids  brought 
down  by  rain-water  is  of  more  importance, 
particularly  in  the  case  of  limestones.  The 
calcium  carbonate  is  converted  into  gypsum,  and 
this  crystallising  with  an  increase  in  volume 
of  slightly  more  than  double  causes  a  disruption 
of  the  surface  layers  of  the  stone.  (On  the 
weathering  of  Portland  stone  and  magnesium 
limestone  in  the  London  atmosphere,  see  £.  G. 
Clayton,  Proe^  Ghem.  Soo.  1901,  xvii,  p.  201 ; 
W.  Pollard,  Summ.  of  Progress,  GeoL  Survey 
United  Kingdom,  for  1901,  1902,  p.  83).  Here 
also  the  rate  of  decay  is  governed  more  by  the 
state  of  aggregation  of  the  calcium  carbonate 
than  by  the  chemical  composition  of  the  stone ; 
a  stone  with  a  cement  of  meiedy  calcium  carbonate 
going  much  more  quickly.  The  sodium  and 
magnesium  salts  of  sea-water  blown  as  spray 
on  buildings  often  have  a  deleterious  effect. 
Stones  containing  nodules  of  iron-pyrites  i^ould 
be  rejected,  since  this  mineral  is  readily  decom- 

Sosed,  giving  rise  to  unsightly  stains  and  pro- 
uciog  free  sulphuric  acid  which  causes  further 
injury  to  the  stone. 

Preservatives  against  decay  include  painting 
the  surface  with  oil-colours ;  or  saturating  the 
surface  with  a  solution  of  sodium  sUicate,  which 
may  be  followed  by  treatment  with  a  solution  of 
calcium  chloride.  The  carved  stonework  (lime- 
stone) of  the  Houses  of  Parliament  and  the 
Abbey  at  Westminster  was  restored  by  Sir  A.  H. 
Church  by  the  application  of  baryta  water,  the 
crumbly  surface  layer  of  gypsum  being  thereby 
converted  into  more  resisting  barium  sulphate. 
The  different  kinds  of  artificial  stone  manu- 
factured for  building  purposes  are  classified 
roughly  by  Howe  {see  references  below)  as 
follows : — 

1.  Stones  made  of  natural  rock  fragments 
held  together  by  Portland  or  magnesium  cement. 
E.g.  *  Pentuan  stone  '  and  concrete. 

2.  Similar  stones  subjected  to  a  subsequent 
hardening  process  by  treating  with  sooium 
silicate.  Here  the  action  of  the  cement  is 
modified  and  hydrated  calcium  silicates  are 
formed  which  harden  the  stone.  E.g.  *  Victoria 
stone '  made  from  the  granite  of  Groby  and 
Mount  Sorrel,  Leicestershire,  *  Atlas  stone,*  and 

*  Hard  York  non-slip  stone '  made  from  sand- 
stone. 

3.  Stones  in  which  granulated  rock  or  sand 
is  cemented  with  calipium  carbonate.  E.g. 
Thom's     patent    reconstructed    stone,     many 

*  lime-sand'  blocks,  and  pumice-,  trass-,  and 
pozzolana-lime  stones. 

4.  Stones  in  which  more  or  less  of  the  calcium 
c€irbonate  cement  ia  replaced  by  calcium  silicate. 

5.  Stones  cemented  by  bituminous,  asphaltic, 
or  other  organic  substance. 

Beferefhces. — J.  A.  Howe,  The  Geology  of 
Building  Stones,  London,  1910;  J.  Watson, 
British  and  Foreign  Building  Stones,  Cambridge, 
1911 ;  H.  Ries,  Building  Stones  and  Clav- 
products,  a  handbook  for  architects.  New  York, 
1912 ;  G.  P.  Merrill,  Stones  for  Building  and 
I)eooration,  3rd  ed..  New  York,  1903 ;  J.  ]£r8ch- 
wald.  Die  Prnfung  der  naturliohen  Bausteine 
auf  ihre  Wetterl^standigkeit,  Berlin,  1908 ; 
J.  Hirschwald,  Handbuch  der  bautechnischen 
Gesteinsprufung,  Berlin,  1912;  W.  A.  Parks, 
Report  on  the  Building  and  Ornamental  Stones 
of  Canada,  Dept.  Mines,  Ottawa,  1912.    Refer- 


ence may  also  be  made  to  the  petrographical 
text-books  of  .J.  J.  H.  Teall,  A.  Haiker,  and 
P.  H.  Hatch.  K  J.  S. 

BULBOCAPNIHE.    See  xmdeT  CorydaUne. 

BUNTKUPFERERZ(Ger.).  Variegatedcopper 
ore.  This  term  is  commonly  applied,  even  by 
English  mineralogists,  to  an  ore  of  copper  other- 
wise known  as  Bomite  (q.v.),  BrvbeacUe^  PkUUpS' 
ite,  and  Purple  Copper  Ore.  Cedled  '  horse-fleoh 
ore  *  ]^  the  Cornish  miners.  L.  J.  S. 

BUPLEUROL.  An  alcohol  found  in  the 
higher  boiling  fractions  of  the  oil  of  Bupteumm 
fnUicosum.  Optically  inactive,  sp.gr.  0*8490/1 7*, 
nj^==  1-4608;    b.p.  209*-210*»/762  mm.    Haa  a 

faint  odour  of  roses.  Ckmtains  one  doable 
linkage  and  yields  an  urethane  melting  at  45\ 
Probably  a  dihydro-derivative  of  nerol  of  the 
constitution : 

(CHg)aCH(CJHt)»C( :  CH,)-CH,CH,OH 

(Franceeconi  and  Semagiotto,  AttL  R.  Acoad. 
del  Linoei,  1913,  22,  L  34,  148 ;  J.  Soc  Ghem. 
Ind.  1913,  251). 

BURGUNDY  FITCH  or  NORWAY  SPRUCE 
RESIN.  {Ftchienkar,  Tannenhant,  Ger. ;  Paix 
des  Vosges,  Poix  blanche,  Poix  jaune,  Barras, 
Fr.)  The  resin  of  Picea  excdsa  (Link.)  Durified 
by  melting  in  hot  water  and  stnUmng.  it  is  an 
opaque,  yellowish-brown,  hard,  brittle  resin ;  its 
taste  is  sweet  and  aromatic.  It  is  veiy  soluble 
in  glacial  acetic  acid,  acetone,  and  ^oohoL 
Used  in  making  plasters.  It  is  much  adulte- 
rated. The  substance  usually  sold  by  this  name 
in  England  is  made  by  melting  colophony  with 
palm-oil  or  some  other  fat,  and  stirring  in  water 
to  make  the  mixture  opaque  (Morel»  Phaoo.  J. 
[3]  8,  342)  (v.  RBSors). 

BURNETTS  FLUID.  A  solution  of  zino 
chloride  is  commcmly  known  as  Sir  William 
Burnett's  disinfecting  fluid.  It  is  used  as  a 
disinfectant  and  as  a  preservative  of  construc- 
tional timber. 

BURTON  WATER  CRYSTALS  contain,  ac- 
cording  to  Moritz  and  Hartiey,  31-8  GaO,  40*4 
SO,,  1-04  CI,  6-46  MgO,  and  21*19  OH,  (J.  Soa 
Chem.  Ind.  2,  82). 

BUSH   SALT.    A    light-brown    or   greyiah 

gowder  prepared  bv  th^  natives  of  Saongea  by 
xiviating  the  ashes  of  the  se^Ke,  Cypems 
Haspan,  L.  Contains  77*77  p.c  KCl,  and  18*48 
KjSO^,  with  traces  of  sodium  salts  and  oiganic 
matter  (Lenz,  Ber.  deuts.  Pharm.  Ges.  1911,  21, 
270). 

BUSSORAH  GUM  v.  Gums. 

BUTALANINE  v.  Vaunb. 

BUTANE  V.  Butyl-  compoukds. 

BUTANONE  (Meihi^kthylkeione)  v.  Kxtonss. 

BUTEA  FRONDOSA.  The  Bvlea  frondosa^ 
also  called  Dhak  or  Ptdas,  is  a  fine  tree,  3(MtO 
feet  high,  belonging  to  the  order  Legumino8€B. 
It  is  common  throughout  India  and  Burma,  and 
is  found  in  the  North- West  Hunalaya.,  as  fakr  as 
the  Jhelum  River.  The  flowers,  which  in  the 
dried  condition  are  known  as  tfso,  kesif,  keanda 
or  paUs-k^pptQ,  have  a  bright-orange  oolonr, 
and,  althougn  they  are  much  larger,  closely  re- 
semble in  appearance  the  oonunon  gorse-flower 
{Ulex  europceus),  with  which,  indeedt  thev  are 
botanically  allied.  Lane  quantitiea  of  the 
flowers  are  collected  in  March  and  April,  and 
employed  by  the  natives  to  produoe  a  yfXkaw 
dye,  much  used  during  the '  Holi  *  f estivaL    The 


BUTEA  FKONBOSA. 


201 


dyeing  operation,  which  consists  in  steeping  the 
material  in  a  hot  or  cold  decoction  of  the  flowers, 
is  virtually  a  process  of  staining,  because  the 
colour  can  be  readily  washed  out.  On  the  other 
hand,  a  more  permanent  result  is  sometimes 
produced  either  dv  first  preparing  the  cloth  with 
alum  and  wood  ash  or  by  adding  uiese  substances 
to  the  dye-bath. 

From  the  Buiea  frondosa  is  also  obtained 
the  so-called  *  Butea  gum  *  or  *  Bengal  kino,* 
employed  by  the  natives  for  tanning  leather, 
ana  the  tree  is  of  additional  interest  because  in 
many  parts  of  India  the  lac  insect  {Coccus  lacca) 
is  reared  upon  it.  This  latter,  as  is  well  known, 
causes  the  formation  of  stick  lac,  from  which 
shellac  and  lac  dye  are  prepared. 

Butin  CisHisOj.  The  flowers  are  extracted 
with  water,  and  the  extract  disested  boiling  with 
a  little  sulphuric  acid.  A  light  viscous  precipi- 
tate devoid  of  dyeing  property  separates,  and 
this  is  removed  while  hot  and  the  filtrate  left 
over-night.  The  clear  liquid  is  now  decanted 
from  a  small  quantity  of  tarry  substance,  and 
partially  evaporated  on  the  water-bath.  A 
further  quantity  of  a  black  viscous  precipitate 
thus  separates,  and  when  this  has  been  removed 
the  filtrate,  after  some  days,  deposits  crystals  of 
the  colouring  principle.  For  purification  the 
product  is  dissolved  in  a  little  alcohol,  the 
mixture  poured  into  ether,  and  the  solution  well 
washed  with  water.  The  liquid  is  evaporated, 
and  the  residue  repeatedly  crystallised  from 
dilute  flJcohol  (Perkin  and  Hummel,  Ghem.  Soc. 
Trans.  1904,  85,  1459). 

Butin  crystallises  from  alcohol  in  colourless 
needles  with  iH,0,  m.p.  224'*-226°,  and  from 
water  in  pale-vellow  neeoles  with  2H,0;  dissolves 
in  alkaline  solutions  with  a  pale  orange-red  tint, 
and  gives  with  alcoholic  acetate  of  le»i  a  faintly 
yellow  almost  colourless  precipitate.  It  forms 
a  triacttyl  derivative  G,,H,Ot(GtH,0)s,  colour- 
lees  leaflets,  m.p.  123°-125^,  and  9,tr%btnzoyl  com- 
pound Ci5HtOB(C;HjO)s,  colourless  needles, 
m.p.  166*»-157*'.  On  fusion  with  alkaU  at  200**- 
220°  butin  gives  protocaiechuic  acid  and  reMrcinol. 
When  butin  is  boiled  with  dilute  potassium 
hydroxide  solution,  the  pale-coloured  liquid 
becomes  much  darker,  and  on  acidifying  an 
orange  crystalline  precipitate  separates  which 
consists  ot  huUin, 

But^ln  Cifiifiit'Bi^O,  needles,  melts  at 
213°-2l5°  ;  dissolves  in  alkaline  solutions  with 
a  deep  orange-red  colour,  and  with  alcoholic  lead 
acetate  gives  a  deep-red  precipitate.  Acetyl- 
huUin  Cj4Hh05(C,H,0)4,  paJeyellow  needles, 
melts  at  129*^-131^ 

When  fused  with  alkalis  butein  gives  reaor- 
cinol  and  protocaiechuic  acid,  whereas  by  the 
action  of  boiling  50  p.c.  potassium  hydroxide 
solution,  protocaiechuic  acid  and  resacetophenone 
are  produced. 

By  methylation  with  methyl  iodide  butin 
gives  hutin  trimeth^ether  C,bH,0,(OGH3)3, 
colourless  plates,  m.p.  119^-121°,  and  also  butein 
trimethyUther  GijH,0,(OGH,)„  yeUow  leaflets, 
m.p.  156^-158^.  In  a  similEkr  manner,  butein 
yields  not  only  butein  trimethylether,  but  also 
butin  trimethylether. 

The  constitution  assigned  to  butein  by  Perkin 
and  Hummel  is  that  of  a  letrahydroxybtnzylidene 
acetophenone  {tetrahydroxych<Uhone)  (1),  and  to 
butin  that  of  the  corresponding  ^ra none  (2) : 


OH 


(1)       0h/\)H  f^OH 

IJ-CO-CH^OH— I     1 


(2) 


and  that  these  formulae  are  correct  has  been 
established  by  the  synthesis  of  butein  and  butin 
trimethylethers  by  these  authors.  Thus  by  the 
condensation  of  resiioetophenone  monomethyl- 
ether  with  veratrio  aldehyde,  butein  trimethyl- 
ether (1)  is  produced : 

OCH, 


0CH^/"Y-0H 


\>CH, 


11. 


OGHyV-O-^DH-^;^^^ 


OCH, 
OGHa 


U-^- 


-00— CH, 


and  this,  when  digested  with  boiling  dilute 
alcoholic  sulphuric  acid,  a  method  devised  by 
V.  Kostanecki  and  his  colleagues  (Ber.  1904,  37» 
784,  773,  779),  gives  butin  trimethylether  (II). 

Somewhatlater  (Ber.  1911,44,3502)  Goschker 
and  Tambor  prepared  butein  itself  by  treating 
protocatechuic  udehyde  and  resacetophenone 
in  boiling  alcohol  with  potassium  hy(ht>xide 
solution  and  found  this  to  be  identical  in  all 
respects  with  the  natural  product.  Buiein 
methykther,  yellow  needles,  m.p.  185°,  3' :  4'* 
buiein  dimethylether,  yellow  prisms,  m.p.  203**, 
and  buiein  tetramethytether  (Ber.  1912,  45,  186), 
colourless  needles,  m.p.  89°,  were  idso  described. 

Butein  itself  is  also  converted  into  butin  by 
means  of  dilute  alcoholic  sulphuric  acid,  and  the 
butin  can  again  be  transformed  into  butein  by 
the  action  of  potassium  '  hydroxide  solution. 
With  alcoholic  potash  butin  trimethylether  also 
gives  butein  tnmethvlether,  and  these  changes 
are  readily  explained  if  it  is  assumed  that  the 
intermediate  compound  or  its  tri methyl  ether 


Oh/N)H       GH(OH 


OH 


I 


l^^-OO—CH, 


is  the  first  product  of  the  reaction  in  each  case, 
and  that  this  subsequently,  by  loss  of  water, 
passes   into   either   chalkone  or  flavanone,  or 

Doth. 

When  butein  dissolved  in  acetic  acid  is 
treated  with  a  few  drops  of  sulphuric  add,  and 
the  solution  is  boiled,  a  new  substance  gradually 
separates  in  the  form  of  ciystals,  which  possess 
a  beetle-green  iridescence,  and  dissolves  in 
alkaline  solutions  with  a  deep-blue  colour.  The 
add  liquid  decanted  from  the  crystals,  on  dilu- 
tion with  water,  gives  a  brown  precipitate 
soluble  in  alkalis  with  a  bluish- violet  colouration, 
which  dyes  mordanted  calico  shades  of  a  similar 
character  to  those  yielded  by  anthragallol.  It 
appears  probable  that  this  more  soluble  substance 


702 


BUTEA  FRONDOSA. 


represents  the  first  product  of  the  reaoUon,  and 
is  subsequently  converted  into  the  ffreen 
iridescent  compound.  A  consideration  of  the 
formula  of  butein  renders  it  unlikely  that  these 
new  substances  are  anthraquinone  derivatives  ; 
on  the  other  hand,  it  is  suspected  that  bv  loss 
of  water  ring  formation  takes  place,  and  that 
an  indone  derivative  of  the  following  type  is 
first  produced : — 

OH 


B0/\ 

J-00 


.c-/~\ 


\_/ 


OH 


— CH 


Butin  and  butein  dye  mordanted  woollen 
cloth  identical  shades,  though  as  butin  gives 
with  an  alcoholic  lead  acetate  a  practically 
colourless  precipitate,  it  is  not  to  be  regarded  as 
a  colouring  matter.  In  other  words,  butin  is 
merely  a  colouring  principle,  and  is  converted 
during  the  dyeing  operation  by  the  action  of 
the  mordant  mto  the  colouring  matter  butem.^ 
The  following  shades  are  obtained : — 

Chromium     Aluminium      Tin  Iran 

Beddish-brown  Brick-red  Full  yellow  Brownish-black 

and  these  are  strikingly  similar  to  those  yielded 

by  some    of    the  hydrozybenzyUdenecoumara- 

nones  artificially  prepared  by  Friedldnder  and 

Rudt  (Ber.  1896,  29,  879)  [see  above). 

The  butea  flowers  contain  but  a  trace  of 
free  butin  or  butein,  and  the  glucoside  present, 
which  has  not  yet  been  isolated,  is  probal>ly 
that  of  butin.  This  glucoside  does  not  decom- 
pose readily  during  the  dyeins  process,  hence  the 
flowers  do  not  dye  mordanted  cotton.  In  wool- 
dyeing,  where  acid-baths  are  employed,  a  better 
result  is  obtained,  although  in  this  case  the 
shades  possess  but  little  strength.  If  the 
glucoside  is  first  hydrolysed  by  boiling  the  flowers 
with  dilute  hydrochloric  acid,  or  if  sulphuric 
acid  is  employed,  and  the  add  then  neutralised 
with  sodium  carbonate,  on  evaporation  a 
material  is  obtained  which  readily  ayes  by  the 
usual  methods.  Such  products  give  the  follow- 
ing shades  :  with  chromium,  deep  terra-cotta ; 
with  aluminium,  a  bright  oranse;  with  tin, 
bright  yellow ;  and  with  iron,  a  browmsh-olive. 
The  cliromium  colour  is  characteristic,  and  is 
much  redder  in  tint  than  that  yielded  by  any 
known  natural  yellow  dye.  A.  G.  P. 

BUTEA  GUM.  The  juice  of  Butea  frondoaa 
(Roxb.),  often  sent  into  the  market  instead  of 
genuine  kino.  It  forms  black-brown,  slightly 
lustrous,  brittle  lumps,  has  an  astringent  taste, 
and  yields  pyrocatecnin  by  diy  distillation.  V, 
Kino. 

BUTINENES  C^He. 

1.  Eryihrene,  vinyl-ethylene  or  pyrrciene, 
CH| :  CH'CH  :  CH^  occurs  in  coal-gas  and  is 
said  to  be  formed  by  passing  fusel-oil  through  a 
red-hot  tube.  Obtained  by  boiling  erythrite 
with  strong  formic  acid  or  by  the  action  of 
potassium  hydroxide  on  di-methylpyrrolidine 
methyliodide.  Also  by  condensing  acetaldehyde 
with  ethyl  alcohol  in  presence  of  alumina  or  other 
catalyst.    Forms  a  tetrabromide,  m.p.  119°. 

^  This  mult  has  been  criticised  by  GOsohker  and 
Tambor,  who  by  the  employment  of  mordanted  calico 
obtained  from  butin  very  weak  shades.  It  la,  however, 
certain  that  by  the  use  of  mordanted  wool  a  conversion 
of  butin  into  butein  occurs. 


2.  Etkylacetylene  GH,*OHa*C:CH.  Obtained 
by  treating  methyl  ethyl  ketone  with  alco- 
holic potam  and  phosphorus  pentachloride,  or 
by  passing  acetylene  and  ethylene  through  a 
red-hot  tube.    Forms  a  tetrabromido,  m.p.  1 13^. 

3.  Crotonylene  CH,-C:C-CH9.  Obtained  by 
acting  on  bulylene  bromide  or  di-bromo-butane 
with  alcoholic  potash,  or  by  distilling  barium 
acetate  with  sulphur.  Dilute  sulphuric  acid 
converts  it  into  hexa-methyl-benzene. 

A  butinene  is  also  formed  by  the  destructive 
distillation  of  caoutchouc. 

BUTTEB*  Butter  is  the  fatty  product  pe- 
pared  from  the  milk  of  the  cow.  When  similar 
substances  are  obtained  from  the  milk  of  other 
mammals,  their  origin  is  indicated  in  the  descrip- 
I  tion,  e,g.  goats*  butter,  buffalo  butter.  Fatty 
food  substances  of  vegetable  origin  and  similar 
to  butter  in  consistency  are  also  sometimes 
desoribed  as  butter,  but  with  a  prefix,  as  veff^- 
table  htUter,  cocoa-nut  butter. 

Butter  consists  of  milk-  or  butter-fat,  with 
water,  and  small  quantities  of  milk  proteins, 
lactose,  mineral  salts,  and  natural  oolouring 
matter.  The  proteins  and  lactose,  together 
with  the  minentl  matter  associated  therewith, 
are  spoken  of  coUeotively  as  curd.  Gommercial 
butter  may  also  contain  common  salt,  preserva- 
tives, and  oolourinff  matter,  addea  during 
manufacture.  The  aaded  salt  and  preservatives 
are  not  included  with  the  curd  in  giving  the 
composition  of  butter,  but  are  separately  esti- 
mated. 

Fat  exists  in  milk  in  the  form  of  miniite 
globules  in  a  state  of  suspension  in  the  milk 
serum.  In  the  process  oi  churning,  the  fat 
globules  coalesce,  producing  irregularly-shaped 
granules  of  butter.  These  are  strained  from  the 
serum»  or  buttermilk,  washed  with  water,  and 
worked  into  a  mass  on  a  table  by  means  of 
mechanical  rollers,  or,  as  in  older  processes,  by 
huxd.  Salt,  preservatives,  oolourinff  matter, 
are  added,  if  desired,  after  washing  the  butter 
granules  with  water. 

As  regards  the  influence  of  salt  on  the 
chanses  taking  place  in  storage  it  has  been 
found  that  unsalted  butter  in  commercial  oold 
storage  keeps  as  well  as,  or  better  than,  salted 
butter.  According  to  Washburn  and  Dahlbeig 
(Bull.  Agric.  Intell.  1918,  9,  996),  salt,  exclusive 
of  its  antiseptic  property,  hastened  the  deteriora- 
tion of  butter ;  when  stored  at  -26'  (— 16*  F.), 
unsalted  butter  kept  as  well  as  salted  butter, 
and  the  bacteria  decreased  more  rapidly.  On 
the  other  hand,  thev,  as  well  as  the  acidity, 
increased  more  rapidly  in  the  unsalted  butter 
at  ordinary  temperatures. 

According  to  D.  C.  Dver(J.  AjKric.  Research, 
1916,  6,  927)  the  unpleasant  fliEkvourB  which 
develop  in  butter  durins  cold  storage  are 
produced  by  chemical  change  in  non-fatty 
ingredients. 

Milk  may  be  dinnstly  churned  for  the  purpose 
of  obtaining  butter,  and,  in  some  remote 
districts,  this  process  is  still  followed.  It  is, 
however,  usual  to  chum  *ircam,  that  is,  the  fattv 
layer  which  rises  to  the  surface  on  allowing  milk 
to  stand  or  on  subjecting  it  to  centrifugal 
action. 

Cream  may  be  churned  in  a  fresh  condition 
before  souring  has  taken  place.  In  such  a  case, 
the  period  of  churning  is  longer,  and  the  opera- 


BUTTER. 


703 


iton  muBt  be  carried  out  at  a  lower  temperature 
than  when  ripened  cream  or  milk  is  employed. 
It  is  therefore  usual  to  chum  ripened  cream. 
The  ripening  may  be  efiFected  by  standing  the 
cream,  and  is  accelerated  by  the  addition  of  a 
little  buttermilk  or  pure  culture  starters  con- 
taining suitable  bacteria.  The  taste  of  cream 
is  affected  by  certain  moulds  {Oidium  Iodic,  and 
P.  chrygngenum),  and  the  enzymes  secreted  by 
them  may  develop  abnormal  flavours  in  the 
butter.  Mould  spores  do  not  germinate  or 
grow  in  butter. 

Various  views  are  held  as  to  what  takes 
place  during  the  operation  of  churning.  Fleisoh- 
mann  (Book  of  the  Dairy,  159)  states  that '  the 
milk-fat  is  converted  from  fluid  to  solid  condi- 
tion by  the  shaking  which  it  undenoes,'  that  is, 
that  churning  resmta  in  the  solidification  of  fat 
which  in  milk  is  in  a  superfused  condition.  On 
the  other  hand,  Richmond's  results  (Dairy 
Chemistry,  Ap.  339)  would  indicate  that  the 
fat  before  churning  may  be  in  a  solid  condition. 
Whether  fat  as  present  in  milk  is  surrounded 
with  some  form  of  membrane  (B^hamp,  Storch) 

Sr  with  a  thin  watery  covering  (Fleischmann). 
e  mechanical  operation  of  cnuming  appears 
to  rub  away  or  remove  the  protective  coating, 
and  thus  enable  the  milk  globules  to  coalesce, 
forming  butter.  As  to  the  theories  reffardLing 
the  structure  of  the  fat  globules  in  milk,  see 
papers  by  Storch  (Analyst,  1897,  22,  197),  Beau 
(Revue  G^n^rale  du  Lait,  2,  16,  1903),  and 
Richmond  (Analyst,  1904,  29,  185). 

The  quantity  of  water  remaining  in  finished 
butter  IB  TOVcmed  by  the  conditions  of  manu- 
facture. Churning  at  too  high  a  temperature 
renders  tiie  removal  of  excess  water  during 
working  difficult.  It  results  in  over-worked  or 
*  greasy*  butter;  or  butter  with  an  excessive 
quantity  of  water.  The  maximum  limit  per- 
missible in  England  for  water  in  butter  is  16  p.c. 
Canada,  Queensland,  Holland,  have  the  same 
limit.  Victoria  has  15  p.c.;  Germany,  16  p.o. 
for  salted,  and  18  p.c.  for  unsalted ;  and  Belgium, 
16p.c 

The  proportion  of  curd  may  vary  from  0-2 
to  2*0  p.a  according  to  method  of  manufacture, 
lower  quantities   TOing  present   where  freshly 
separated  cream  is  churned  than  in  the  case  of 
ripened  cream.    Well-made  butter  rarely  con- 
tains so  high  a  quantity  as  2  p.c.,  and  where  this 
quantity  is  found,  examination  should  be  made 
for  the  presence  of  added  non-fatty  milk  solids. 
The  Government  Laboratory  has  found  (Jour. 
Board  of  Agric.  1912,  19,  760)  the  quantity  of 
curd  in  imported  butter  to  range  from  0'4  to 
1*86  p.c.,  average   1*04.     Out  of  366  samples 
only  11  contained  more  than  1*5  p.c.  of  curd. 
Butter  taken  from  factories  in  Great  Britain 
ransed  from  034  to  1*86  p.c.,  in  Ireland  from 
0-63  to  1-87  p.c.    No  Umits  have  been  fixed 
as  to  the  non-fatty  milk  solids  permissible  in 
butter,  but  the  Butter  and  Margarine  Act,  1907, 
^ves  power  to  the  Board  of  Agriculture  and 
Fisheries  to  make  regulations  on  the  point. 

Van  Slyke  and  Hart  (J.  Amer.  C^em.  Soo. 
1006,  27)  state  that  when  0-5  p.c.  or  over  of 
lactic  acid  is  in  the  cream,  the  casein  is  present 
in  the  butter  as  casein  lactate,  but  in  butter 
made  from  sweet  cream  as  calcium  casein.  They 
also  make  suggestions  with  rega^  to  the 
relation  between  casein  compounds  and  mottled 


butter.  Richmond  (Analyst^  1906,  31,  178)  has 
found  the  average  amount  of  casein  to  be 
0-38  p.c.,  and  not  to  exceed  0*5  p.c. 

The  mineral  matter  in  butter  (to  which  no 
foreign  substance  has  been  added  during  manufac- 
ture) consists  of  the  inoisanic  substances  derived 
from  the  buttermilk  enclosed  within  the  butter 
granules,  and  from  the  caseous  matter  adhering 
to  the  fat.  It  is  really  the  ash  of  the  curd,  or 
the  non-fatty  milk  solids  of  the  butter. 

When  butter  is  heated,  the  fat  melts  and 
separates  from  the  aqueous,  curdy  portion. 
After  allowing  this  to  settle,  the  fatty  layer  Is 
filtered  throueh  a  warm  funnel,  and  the  fat 
obtained  as  a  clear  oil,  usually  of  a  yellow  colour, 
but  under  certain  conditions  almost  colourless, 
setting  to  a  granular  crystalline  mass.  The  fat 
so  obtoined  consists  of  glycerides  of  fattv  acids 
together  with  the  natural  or  added  colouring 
matter,  if  any,  of  the  butter,  and  some  unsaponi- 
fiable  substances,  e.g.  cholesterol,  associated  with 
the  natural  fat.  The  total  quantity  of  the 
nnsaponifiable  matter  does  not  exceed  0*4  p.c. 
(Bomer,  Zeitsch.  Nahr.  Grenussm.  1901,  4, 
1070). 

The  glycerides  of  butter-fat  contain  butyric, 
oaproic,     caprylic,     capric,     lauric,     myrustic, 
palmitic,  stearic,  and  oleic  acids,  as  triglycerides, 
with,  possibly,  a  small  quantity  of  mono-  and  di- 
glycerides.      Bell    has  shown  the  presence   of 
'  mixed  *  glycerides,  and  describes  (CJnemistry  of 
Foods,   &)    an  oleopalmitobuWrate.    Browne 
(J.  Amer.  Chem.  Soc.  1899,  613)  finds  1*0  p.c. 
of   dihydroxystearic    acid ;     but   Lewkowitoch 
throws  doubt  upon  the  presence  of  any  hydroxy 
acids  (Oik  and  Fats,  4th  od.  ii.   667).    The 
composition,  as  given  by  Bell  (C!hem.  of  Foods, 
48),  is  compared  with  that  given  by  Browne  (J. 
Amer.  Chem.  Soc.  1899,  21,  807). 

100  parts  of  fat  on  saponification  yield  : 


• 

BeU 

Browne 

Butyric  acid 

613 

5-46 

Caproic    „ 

.    1 

2-091 

Caprylic  „ 

.    J     209 

0*49}  2*90 

(]!apric      „ 

.  ) 

0-32) 

Lauric     „ 

2*67 

Myiistic  „ 

9-89 

Palmitic  „ 

40-46 

38*61    60*33 

Stearic     „ 

1*83 

Oleic        „ 

3610 

32-50 

Dihydroxy  steal 

rio  aci 

d 

1-00 

Siegfield  (Zeitsch.  Nahr.  Genussm.  1912,  24, 
45)  found  no  stearic  acid,  and  Smedley  (Bio. 
Jour.  1912,  6,  451)  found  10  p.c.  of  stearic  acid 
in  butter  fat.  Holland,  Reed  and  Buckley 
(J.  Agric.  Research,  1916,  101 ;  ibid.  1918,  719) 
have  also  found  high  proportions  of  stearic  acid 
present.  Thev  found  the  percentage  quantities 
of  various  acicLB  in  butter-fat  as  follows  :  butyric 
acid,  3*163  ;  caproic  acid,  1*360 ;  caprylic  acid, 
0*976 ;  capric  acid,  1*831 ;  lauric  acid,  6*896 ; 
myristic  acid,  22*618;  pabnitic  acid,  19*229; 
stearic  acid,  11*384  ;  oleic  acid,  27*374.  These 
results  were  obtained  by  esterification  of  the 
butt«r-fat,  and  subsequent  fractionation  of  the 
resulting  esters.  For  details  the  original  paper 
must  be  consulted. 

Caldwell  and  Hurtley  (Chem.  Soc.  Trans. 
1909,  96,  863)  have  fractionally  distilled  samples 
of  butter  fat  in  the  vacuum  of  the  cathode 
light,   and   determined   certain  values   of   the 


704 


BUTTER. 


distillates.  They  conclude  that  there  is  no 
tributyiin  in  bntter-fot,  and  probably  no  tri- 
olein, the  oleic  acid  being  distnbuted  among  the 
glycerides  present,  most  of  it  as  oleostearo- 
palmitin.  Caldwell  and  Hurtley  {l.c,)  have  also 
similarly  distilled  the  fatty  acids.  According 
to  Ambeiger  (Zeitsch.  Nahr.  Gennssm.  1918,  35, 
313)  butter-fat  contains  a  small  quantity 
(2*4  p.c.)  of  triolein;  the  greater  part  of  the 
oleic  acid  existing  as  mixed  elyoerides.  Butyric 
and  other  volatile  acids  are  also  present  as  mixed 
glycerides ;  tributyrin  cannot  be  isolated. 
Examination  of  the  alcohol-soluble  portion  of 
hydrogenised  butter-fat  shows  that  the  original 
fat  contains  butyrodiolein,  butropalmito-olein 
and  oleo-dipalmitin. 

The  most  characteristic  feature  of  butter-fat 
is  the  presence  of  fatty  acids  soluble  in  water 
and  volatile  in  steam  ;  and  the  earliest  work  on 
butter  was  directed  to  the  estimation,  directly 
or  indirectly,  of  butyric  acid,  the  largest  con- 
stituent of  the  soluble  or  volatile  portion. 

Hehner  and  Angell  (Butter :  its  Analysis  and 
Adulterations,  Churchill,  2nd  ed.  1877),  following 
the  suggestion  of  Chevreul,  proposed  in  1874  to 
obtain  the  butyric  acid  by  distillation  of  the^ 
acids  liberated  by  dilute  sulphuric  acid  after 
saponification  of  the  fat  with  alkali  In  con- 
sequence of  the  variation  in  the  results,  therf 
proposed  the  determination  of  the  acids  insoluble 
in  water,  Dupr6  subsequently  adding  in  the 
same  process  the  titration  of  the  water-soluble 
acids  (Analyst,  1876).  The  quantity  of  insoluble 
fatty  acids  is  frequently  spoken  of  as  the 
'  Hehner  value.'  The  process  consists  in  saponi- 
fying a  weighed  quantity  of  the  fat  with  alconolic 
potash,  liberating  the  fatty  acids  from  the 
aqueous,  alcohol-free,  soap  solution  with  excess 
of  dilute  sulphuric  acid,  filtering  and  washing 
with  hot  water  the  insoluble  acids,  finally  weigh- 
ing these,  and  titrating  the  dissolved  acios. .  The 
quantity  of  soluble  acids  usually  falls  between 
4*2  and  6*0  p.c.  (calculated  as  butyric  acid),  and 
the  weight  of  the  insoluble  acids  between  90  and 
87*6  p.c. 

Reichert  adopted  a  modification  of  Chevreul 
and  Hehner's  distillation  of  the  butyric  add, 
operating  with  a  definite  quantity  of  fat  under 
prescribe  conditions,  and  thus  avoiding  the 
necessity  of  the  distillation  of  the  whole  of 
the  volatile  acids.  Reichert  took  2 '5  grams  of 
fat ;  and  the  number  of  cubic  centimetres  of  deci- 
normal  alkali  required  to  neutralise  the  distillate 
from  this  quantity,  operating  as  described,  was 
the  original  Reichert  number  (Chem.  Soc.  Trans. 
1879,  A,  406  ;  Zeitsch.  anal.  Chem.  1879,  18,  68). 
Meissl  suggested  the  use  of  5  grams  of  fat 
(Chem.  Soc.  1880,  A,  828),  and  Wollny  added 
a  number  of  modifications  (Chem.  Soc.  1888, 
A,  200).  This  process  was  adopted  by  a  com- 
mittee consisting  of  the  Principal  of  the 
Government  LalJoratory  and  memoers  of  the 
Society  of  Public  Analysts,  as  the  method  to  be 
used  in  the  estimation  of  butter-fat  in  margarine 
(Analyst,  1900,  25,  309).  The  conditions  of 
distillation  must  be  strictly  observed,  as  the 
whole  of  the  volatile  acid  is  not  distilled  during 
the  experiment.  Richmond  {ibid,  1895,  20, 
218)  found  only  87  p.o.  of  the  total  volatile  acids 
in  the  distillate.  (Jensen's  results  confirm  this 
(Zeitsch.  Nahr.  Genussm.  1906,  272).  Leffmann 
and  Beam  used  soda  dissolved  in  glycerol  for 


the  saponification  (Analyst,  1891, 16, 153).  The 
details  of  the  prooess,  as  adopted  by  the  com- 
mittee,  are:  5  crams  o&dear,  melted  fat  are 
weighed  into  a  flask  of  a  capacity  of  800  co, 
and  saponified  with  2  c.0.  of  soda  (prepared  by 
dissolving  sodium  hydroxide  in  equal  weight  of 
water),  and  10  co.  of  alcohol,  by  heatine  on  a 
hot  water- bath  under  reflux  condenser  for  15 
minutes.  After  evaporati<Mi  of  the  alcohol, 
the  dry  soap  is  dissolved  in  100  o.c.  of  hot 
water,  40  c.c.  of  normal  sulphuric  acid  and  a 
few  fragments  of  pumice  are  added,  and  the 
flask  connected  with  a  condenser.  It  is  then 
heated  so  that  110  ac.  of  distillate  are  collected 
in  about  30  minutes.  The  distillate  is  shaken, 
100  ac  filtered  off,  and  titrated  with  ded- 
normal  alkali,  using  phenolphthaleln  as  indi- 
cator. (Further  details  as  to  size  of  flask,  tubes, 
still-heaa,  condenser,  will  be  found  in  the  Analyst, 
1900, 25, 309. )  The  number  of  cubic  contimetrcs 
of  deoinormal  alkali  required  for  neutralisation, 
when  multiplied  by  1-1  and  corrected  to  5  grams, 
is  the  *  Reichert-WoUny  number.' 

The  proportion  of  volatile  acids  in  butter- 
fat  varies.  In  the  late  autumn  season,  in  the 
case  of  cows  fed  in  the  open,  the  batter-fat 
contains  lees  butyric  acid  tnan  it  does  during 
the  spring  and  summer.  Towards  the  close  of 
the  lactation  period,  butter  fat  also  shows  a 
depreciation  in  the  amount  of  volatile  acida. 
Among  other  factors  affecting  the  character  of 
the  fat  are  the  nature  of  we  food,  and  the 
sensitiveness  of  the  cows  to  varying  climatic 
conditions  and  their  surroundings.  Benoe  the 
uncertainty  as  regards  the  limits  that  shouU  be 
adopted.  In  the  case  of  butter  made  from  the 
mUk  of  mixed  herds,  when  the  influence  of 
individual  cases  does  not  seriously  depreciate 
the  butter  from  the  whole  herd,  the  proportaon 
of  volatile  acids  under  ordinary  conditions  of 
feeding  and  housing  reaches  a  maximum  in 
April-May-June,  and  is  at  a  minimum  in 
October-November.  Lewkowitsch  has  collected 
a  number  of  results  representing  the  produce  of 
different  countries  (OUs  and  Fate,  4th  ed.  n.  686). 
Although  the  milk  from  individual  cows  or  small 
herds  may,  in  consequence  of  special  circum- 
stances,  occasionally  yield  butter  fat  giving  a 
Reichert-WoUny  number  below  24,  the  batter 
from  the  mixed  milk  of  herds  under  normal 
conditions  usually  has  a  Reichert-WoUny  number 
falling  between  24  and  32.  The  Gommittee  on 
Butter  Regulations  appointed  by  the  Board  of 
Agriculture  in  this  country  recommended  that 
the  figure  24,  arrived  at  by  the  Reichert- Wollny 
method,  should  be  the  limit  bdow  which  a  pre- 
sumption should  be  raised  that  butter  is  not 
genuine  (Com.  on  Butter  Regns.  Report,  Od. 
174i),  18).  France  his  fixed  a  minimum  limit 
of  24 ;  Germany,  of  25 ;  Sweden,  of  23 ;  the 
United  States,  of  24 ;  Italy  declares  butter  with 
a  Reichert- Wollny  number  bdow  20  adultefsted, 
between  20  and  26  suspicious,  above  26  pure ; 
Belgium  declares  butter  to  be  abnormal,  and  its 
sale  is  prohibited,  if  the  Rekhert-WoUny  number 
falls  bdow  28,  and  if  in  addition  the  fat  has  a 
Zeiss  number  above  44  at  40°,  a  sp-gr.  below 
0-865  at  100^  a  saponification  value  bdow  222, 
and  a  Hehner  number  above  88*5. 

Uandby  Ball  (Analyst,  1907,  32,  202)  gives 
resulto  of  butters  produced  in  Ireland,  and  shows 
that  during  the  months  of  December  and  January, 


BUTTER. 


705 


when  the  output  of  milk  is  lowest,  the  Reichert- 
WcAhky  numher  frequently  falls  below  24.  The 
lowest  numbers  occur  when  the  milk  is  derived 
from  cows  at  the  end  of  the  lactation  period. 

Brownlee  (Jour.  Bept.  Agric.  *for  Ireland, 
1910,  10,  438)  has  nublishod  results  of  analyses 
of  Irish  butter  proauced  in  1008-9.  He  found 
16*2  p.c.  of  samples  below  24, 11*4  p.o.  below  23, 
6-6  p.o.  below  22,  and  1-4  p.c.  below  21.  TBb  tables 
given  by  Brownlee  show  that  throughout  the 
year  the  Reiohert-WoUny  number  varies  in  each 
ease  with  the  percentage  output  of  butter  from 
the  particular  dairy,  and  the  results  confirm  the 
opinion  that  the  chief  factor  influencing  the 
Reichert-WoUny  number  is  the  lactation  period 
of  the  cows  supplying  the  milk. 

The  oonolusion  that  butter  is  genuine  because 
the  Reichert-WoUny  exceeds  24,  may  be  erro- 
neous, as  this  numoer  may  have  been  the  result 
of  mixing  genuine  butter  liavins  a  high  Reichert- 
WoUny  number  with  some  other  fat.  On  the 
other  hand,  butter  falling  below  24  may  be 
genuine  but  abnormaL  In  order  to  be  in  a 
position  to  establish  the  genuineness  of  butter, 
the  Netherlands  Qovemment  has  organised  a 
system  of  butter  control,  by  means  of  which  the 
associated  creameries  are  frequently  inspected 
and  the  butter  produced  regularly  analysed. 
Oonsignments  from  the  factories  bear  a  govem- 
mentiabel,  giving  particulars  of  origin,  so  that 
the  officiids  can  trace  the  butter  and  ascertain  the 
Reichert-WoUny  number  of  the  butter  produced 
at  the  creamery. 

Higher  homologues  of  butvric  acid  volatilised 
in  the  steam  during  the  Reiohert  process  do  not 
whoUy  dissolve  in  the  distillate,  and  the  deter- 
mination of  the  insoluble  portion  affords  another 
index  to  the  character  of  the  fat,  as  wiU  be  seen 
later. 

Butter-fat  has  a  sp.gr.  at  37*8737-8'*  of 
0*910-0*913  (Thorpe,  Chem.  Soc.  Trans.  1904, 
249).  The  individual  data  in  BeU*s  resulto 
range  from  0*9094  to  0*9139,  but  he  states  the 
ordmarv  range  is  0*911  to  0-913.  The  sp.gr.  is 
affected  by  prolonged  heating  of  the  fat  andf  also 
by  the  storage  of  the  fat  for  a  lengthened  period- 

The  reac&ne  with  the  Zeiss  butyro-relracto- 
meter  at  45°  falls  usually  between  38  and  42. 
In  371  samples  of  genuine  butter  examined,  the 
range  was  37  to  45  (Com.  on  Butter  Regns., 
Ap.  585).  Excluding  14  exceptional  butters, 
the  uverage  range  was  39-4  to  42*0  (Chem.  Soc. 
Trans.  1904,  249).  (Zeiss  readings  are  taken  at 
various  temperatures  b^  different  observers. 
To  convert  the  scale  divisions  observed  at  a 
lower  temperature  into  the  scale  divisions  at  a 
higher  temperature,  deduct  0-55  of  a  division 
for  each  decree  of  temperature  that  the  reading 
has  been  taken  below  the  required  temperature ; 
conversely,  add  0*55  of  a  divirion  for  each 
degree  of  temperature  that  the  reading  has  been 
taken  above  tne  required  temperature). 

The  saponification  value  of  the  fat  was 
BUffgested  by  Koetstorffer  (FrdL  1879,  199),  and 
is  fraquently  known  as  the  Kodtstorffer  number. 
It  is  the  quantity  of  potash  expressed  in  miUi- 
grams  required  to  saponify  1  gram  of  fat.  The 
glycerides  in  butter-fat  contain  acids  of  com- 
paratively low  molecular  weights;  inconsequence, 
the  <f uantity  of  potash  for  saponification  wiU  be 
relatively  high  when  compared  with  fats  in 
which  the  glycerides  contain  only  acids  of  high 

Vol.  1,—T. 


molecular  weight,  as  in  animal  fats  in  f^eneral. 
Butter-fat  gives  figures  on  the  average  between 
219-9  and  232*5  (lliorpe).  KoStstorffer  gave 
227  as  a  mean  figure.  This  value  bears  a  dose 
relationship  to  the  Reichert  number. 

The  iodine  value  varies  considerably,  falling 
between  260  and  35*0  (Habl),  29*0  and  43^ 
(Jensen),  and  26*0 and  380  (WoUny). 

The  various  data  show  their  dependence 
upon  one  another,  within  certain  limits,  when  a 
comparison  is  made.  This  parallelism  is  shown 
in  the  foUowing  table  (Thorpe,  Cbem,  Soc 
Trans.  1904,  254) :— 


i 


o 


7 
17 
15 
27 
37 
51 
78 
56 
41 
18 
JO 

367 


w 

& 


pi 


22-5 
23*5 
24-5 
25*5 
26*5 
27*5 
28*5 
29*5 
30-5 
31*3 
32*6 


I, 


SS 


QQ 


0-9101 
0-9104 
0*9108 
0-9110 
0-9113 
0-9114 
0-9118 
0*9120 
0*9123 
0*9125 
0-9130 


219*9 
221*3 
223-3 
223*4 
225-3 
226*7 
228*3 
229*9 
231*4 
232*2 
232*5 


S> 


420 
41*5 
41*5 
41*3 
410 
40*6 
40*1 
40*1 
39*9 
39*7 
39*4 


00 


4-3 
4*6 
4*7 
4-8 
4-9 
5-2 
5-4 
5*6 
5-8 
5-7 
60 


90-1 
89-7 
89-4 
89*3 
88*9 
88-7 
88-4 
88-3 
87*9 
87-9 
87-7 


266*9 
265*5 
2650 
264*2 
261*9 
261-7 
260-9 
259-6 
260-1 
2580 
257-8 


The  examination  of  butter  comprises:  (1) 
the  determination  of  water,  fiat,  curd,  salt ;  (2) 
examination  of  the  fat ;  (3)  examination  of  the 
butter  for  preservatives,  colouring  matter,  and 
substances  foreign  to  butter. 

1.  Water.  The  sample  for  examination 
should  be  not  less  than  50  grams,  and  should  be 
placed  in  a  bottle  and  closed  securely  with 
screw-cap  or  stopper.  The  bottle  is  then  heated 
at  a  temperature  of  about  50**  untU  the  butter- 
fat  has  melted,  when  it  is  vigorously  shaken  to 
emulsify  the  fat  and  water.  The  shaking  is 
continued  whUe  the  bottle  and  contents  cool, 
untU  the  butter  is  of  the  consistency  of  thick 
creanL  From  6  to  8  grams  are  then  weighed 
into  a  flat- bottomed  dish,  in  which  is  a  glass  rod 
with  flattened  end.  The  dish  is  heated  on  a 
steam-bath  for  an  hour  with  fittauent  stirrins 
of  the  butter,  after  which  it  is  cooled  and  weighecL 
It  is  again  heated  untU  the  weight  is  constant. 
The  operation  is  considerablv  accelerated  by 
using  aluminium  dishes,  heated  on  an  aluminiuui 
hot  plate  adjusted  to  a  temperature  of  100*  to 
105^ 

Patrick  (J.  Amer.  Chem.  Soc.  1906,  1613) 
carries  out  the  estimation  of  the  quantity  of 
water  by  cautiously  heating  10  grams  of  batter 
in  an  aluminium  vessel  over  the  direct  flame, 
taking  care  to  avoid  over-heating. 

In  Cray's  method  (U.S.  Bept  of  Agric, 
Bureau  of  Animal  Industry,  Giro.  100)  10  grams 
of  butter,  weighed  on  a  parchment  paper,  aro 
placed  in  a  flask  together  with  a  Uttle  amyl- 
acetate,  and  the  flask  directly  heated.  The 
flask  is  connected  with  a  calibrated  tube 
arranged  as  a  reflux  condenser,  the  condensed 
water  and  amyl  acetate  being  collected  in  a 


706 


BUTTER* 


bulb  at  the  bottom  of  the  tube.  When  all  the 
water  is  driven  off,  the  tube  with  the  bulb  is 
removed,  and  inverted,  the  volume  of  water 
being  measured  in  the  calibrated  portion. 

Other  methods  are  Henzold's  (in  which 
pumice  is  mixed  with  the  butter)  and  Wibel's 
(J.  800.  Ghem.  Ind.  1893,  630). 

Fat,  The  butter  from  which  the  moisture 
has  been  expelled  is  extracted  with  ether, 
filtered  from  ourd  and  salt,  and,  after  evapora- 
tion of  the  solvent,  is  dried  and  weighed,  or  the 
matter  insoluble  in  ether  is  weighed,  and  the  fat 
taken  by  difference.  The  fat  may  also  be 
estimated  by  the  Gottlieb  method :  2  grams  of 
butter  are  washed  into  a  graduated  burette  tube 
with  about  8  c.c.'of  warm  water,  and  mixed  with 
1  0.0.  of  ammonia  (sp.sr.  0*880)  and  10  c.c.  ol 
alcohol,  mixing  well  after  each  addition.  The 
tube  is  cooled,  25  cc  of  methylated  ether  added, 
and  the  liquids  mixed;  25  c.c.  of  light  petro- 
leum are  tnen  added,  and  the  tube  carefully 
inverted  several  times  to  mix  the  solutions. 
The  volume  of  the  mixed  ether  solution  which 
separates  on  standing  is  measured,  and  a  known 
portion  removed  and  evaporated* 

Shaw  (U.S.  Dept.  of  Agric,  Bureau  of  Animal 
Industiy,  Giro.  202)  takes  25  grams  of  butter, 
and  using  a  separator,  washes  out  salt  and  curd 
first  with  hot  water,  and  then  with  slightly  diluted 
sulphuric  acid,  finally  measuring  the  volume  of 
fat  The  Governments  of  Queensland,  Victoria, 
and  Germany  have  fixed  a  minimum  limit  for  fat 
of  80  p.c. ;  Italy,  of  82  p.c. ;  and  the  United 
States,  of  82*5  p.c. 

Curd.  In  the  case  of  butters  free  from  salt 
and  preservative,  the  curd  is  the  matter  not 
soluble  in  ether  or  other  solvent.  -The  separate 
determination  of  the  proteins  and  lactose  must 
be  carried  out  to  decide  whether  a  butter  con- 
tains added  non-fatty  milk  products.  15-20 
grams  of  butter  are  weighed  in  a  dish  and  dried 
on  the  water-bath  with  frequent  stirring.  The 
fat  is  extracted  with  ether,  and  the  ether- 
insoluble  matter  transferred  with  concentrated 
Bulphurio  acid  to  a  Kjeldahl  digestion  liask, 
adding  the  filter  paper  used  for  filtration.  The 
quantity  of  nitrogen  multi])lied  by  G'38  gives  the 
proteins.  Kiohmond  gives  G-31)  (Analyst,  1908, 
33,  180). 

The  lactose  is  taken  by  difference,  after 
deducting  from  the  total  curd  the  proteins  and 
inorganic  salts.  But  it  is  in  all  cases  preferable 
to  make  a  direct  determination,  and  this  becomes 
necessary  when  boric  acid  is  present.  The 
lactose  and  proteins  may  then  be  estimated  as 
follows  :  The  residue  from  extraction  with  ether 
of  20  grams  of  butter  is  mixed  with  about  40  o.c. 
of  water,  made  just  acid  with  acetic  acid,  and 
the  proteins  precipitated  by  adding  a  few  drops, 
being  careful  to  avt»iJ  excess,  of  Fehlijig's  copper 
suipliate  solution.  It  is  then  filtered  on  tared 
paper,  washed,  dried  at  100°,  weighed,  anci 
incinerated.  The  weight  less  the  ash  is  the 
proteins.  The  filtrate  is  made  up  to  100  c.c. 
and  an  aliquot  portion  taken  for  gravimetric 
lactose  determination.  Wliere  sugar  only  is 
required,  the  residue  from  ether  extraction  may 
be  washed  into  lUU  c.c.  flask,  cleared  with  copi>er 
sulphate,  made  up  to  J 00  c.c,  iilLered,  and  an 
aliquot  portion  taken.  The  quantity  of  lactose 
should  not  exceed  0-4  p.e.,  and  is  usually  much 
less. 


The  matter  insoluble  in  ether  contains,  in 
addition  to  the  true  card  and  other  non-fatty 
solids  of  milk,  common  salt,  borax,  a  portion  of 
the  boric  acid  (partly  in  solution  in  ether),  and 
certain  other  preservatives,  if  these  have  been 
added  to  the  butter.  The  common  salt  is 
estimated  by  extracting  the  weighed  quantity 
of  curd  in  the  total  ourd  determinatioii  with  hot 
water,  and  titrating  the  solution  with  standard 
silver  nitrate. 

2.  Examlnatioil  of  the  f  At.  The  examination 
of  the  fat  to  ascertain  its  purity  is  one  of  con- 
siderable difficulty,  since  butter  adulteration  has 
been  directed  to  the  admixture  of  fats  prepared 
BO  as  to  give  no  distinctive  redaction.  All  animal 
fats,  such  as  refined  lard  and  beef  fat,  and  many 
vegetable  fats  used  for  this  purpoae,  have 
practically  no  volatile  acids.  Hence  Uie  addition 
to  butter  of  fats  of  this  class  reduces  the  salable 
volatile  acids  number.  Other  vegetable  fats 
contain  volatile  acids  only  partially  soluble  in 
water.  To  this  class  belong  cocoa-nut  oil  and 
palm-kernel  oiL 

Vegetable  fats,  unless  specially  prepared, 
contain  phytosterol,  and  the  detection  of  this 
substance  establishes  the  presence  of  foreign 
fat.  ^  Other  fats,  as  cotton  seed  and  sesame,  give 
specific  reactions,  and  may  therefore  be  directly 
tested  for.  It  has,  however,  been  eetaUiahed 
that  the  constituent  giving  the  reaction  may  be 
communicated  to  a  slight  extent  to  milk  and 
thence  to  butter  through  feeding  tike  Miitnala 
with  oil -cakes  made  from  these  seeds.  Positive 
reactions  in  these  ^  cases  must  therefore  be 
supported  by  other  'evidence.  With  the  object 
of  detecting  the  addition  of  foreign  fat,  it  is 
enacted  in  some  countries  that  margarine  and 
margarine  fats  must  contain,  when  prepared  for 
sale,  a  small  quantity  of  sesame'  ou,  aa  a  tell- 
tale substance  when  butter  with  whioh  rach  fat 
has  been  mixed  is  examined. 

(a)  The  soluble  volatile  acids  are  estimated 
by  the  Reichert-WoUny  process  described  above. 

Reychler  (BulL  Soc  chim.  1901,  25,  142) 
proposed  the  extension  of  the  Reichert-WoUny 
process  to  include  the  estimation  of  the  volatile 
insoluble  acids.  Wauters  (Analyst^  1901»  26, 
128)  modified  the  Reichert  process  and  made  two 
distillations,  determiniof  the  values  for  both 
soluble  and  insoluble  vobtile  acids. 

Polenske  fZeitsoh.  Nahr.  Gennssm.  1904, 
273)  adopts  the  Reichert- Wollny  prooess  and 
estimates  in  the  same  operation  uie  scdable  and 
msoluble  volatile  acids.  5  grams  of  the  fat  are 
weighed  into  a  300  0.0.  flask  and  saponified  with 
2  o.c.  of  soda  solution  and  20  grams  of  glycerol 
by  heating  the  flask  over  the  free  flame.  The 
flask  is  cooled  below  100*,  and  90  ac  of  hot 
water  and  a  little  powdered  pumioe  are  added. 
When  the  soap  is  in  solution  the  fatty  aoida  aie 
liberated  with  60  cc.  of  sulj^uric  acid  (25  0.0. 
pure  U1SO4  in  one  litre),  the  flask  attached  at 
once  to  a  condenser  arranged  vertical]  v,  and 
heated  so  that  110  aa  of  distillate  are  ooUeoted 
in  about  20  minutes.  The  heating  is  then 
stopped,  and  the  receiving  flask  leplaoed  by  a 
measuringjar  to  catch  the  dramings  of  the  eon- 
denser.  The  distillate  is  cooled  to  16%  gantly 
shaken,  and  100  aa  filtered  off  and  titrated 
with  decinormal  soda.  The  number  of  cobio 
centimetres  (multiplied  bv  1*1  and  ooiteoled 
to  6  grams)  is  the  Reichert-WoUny   number. 


BUTTER. 


707 


The  remainder  of  the  distillate  is  poured  on 
the  filter  paper,  and  then  washed  with  three 
quantities,  of  15  c.o.  eaoh,  of  water,  eaoh  of 
which  has  been  passed  in  suocession  through 
the  condenser  tuM,  the  measuring  jar,  and  the 
110  0.0.  flask.  These  washings  are  rejected. 
The  110  ao.  flask  is  then  pbced  under  the 
filter  funnel,  and  the  water-insoluble  acids  dis- 
Bolyed  in  alcohol  by  passing  three  quantities, 
of  15  aa  eaoh,  of  neutral  alcohol,  successively 
through  the  condenser  tube,  measuring  jar,  and 
filter  paper.  The  alcoholic  filtrates  are  titrated 
with  1/10  normal  soda,  using  phenolphthalein  as 
indicator.  The  number  of  cubic  centimetres 
,  required  is  the  insoluble  volatile  acids  number. 
In  butter-fat  this  number  varies  with  the 
soluble  aoids  number.  Polenske  {Lc)  gave  a 
range  of  1-35  insoluble  for  20*0  of  soluble,  to 
3-0  insoluble  for  30  of  soluble.  Individual 
butters  may,  however,  give  numbers  outside 
this  range.  Rideal  and  mirrison  (Analyst,  1006, 
31,  254)  give  results  of  examination  of  a  number 
ol  Engiiah  butters.  Harris  {ibid.  1006,  31, 
353)  shows  the  variation  in  insoluble  acids 
number  for  the  same  soluble  acids  number. 
Hesse  (Chem.  Zentr.  1905, 1, 566)  states  the  limits 

S'ven  by  Polenske  should  be  higher.  Hesse  and 
arris  (/.c)  point  out  the  importance  of  following 
exact  details  of  process,  particularly  in  regard 
to  size  of  pumice.  Harris  gives  varying  results 
obtained  by  operating  with  pumice  ofdi£ferent 
sizes.  Beerbohm  (Milch.  Zentr.  1913,  513) 
states  that  during  lactation,  the  R.W.  number 
falls  but  the  Polenske  number  rises. 

Cocoa-nut  fat  gives  a  soluble  acids  number 
by  this  process  of  7-0  and  an  insoluble  acids 
number  of  15-18.  Henoe  the  addition  of  this 
fat  to  butter  depresses  the  Reiohert-WoUny 
number,  and  increases  the  insoluble  volatile 
aoids  number.  At  the  same  time,  the  Zeiss  and 
iodine  numbers  would  be  lowered,  and  tha 
saponification  value  would  be  increased.  Thus, 
while  the  Polenske  value  alone  might  not  itself 
be  sufficient  evidence  of  adulteration  in  oases  of 
small  quantities  of  admixed  cocoa-nut  fat,  the 
disturbance  of  the  co-relation  between  the  other 
numbers  would  establish  the  presence  of  the 
adulterant.  Palm-kernel  fat  has  a  Reichert- 
WoUny  number  of  5,  and  Insoluble  volatile  acid 
number  of  10-12 ;  other  vegetable  and  animal 
fats  have  a  total  volatile  acids  number  less  than 
1.  The  addition  of  palm-kernel  oil  would 
operate  in  a  similar  manner  to  that  of  cocoa-nut 
fat ;  animal  fat  would  dencess  both  the  soluble 
and  insolubU  volatile  acids,  but  the  former  to 
a  greater  extent  than  the  latter,  lliorp 
(Analyst,  1906,  31,  173)  makes  a  second  distilla- 
tion m  the  ordinary  Reichert  process,  after 
addition  of  more  water,  and  obtains  an  increased 
value  for  the  total  insoluble  volatile  acids.  He 
gives  results  of  examination  of  butters  and 
mixtures. 

Muntz  and  Ooudon  (Hon.  SoL  1904,  18; 
Analyst,  1905,  30,  155)  have  devised  a  similar 
method  for  determining  the  ratio  between  the 
soluble  and  insoluble  volatile  acids.  They 
saponify  10  grams  of  fat  with  hot  strong  aqueous 
potash,  diss<3ve  the  soap  in  water,  add  |£osphorio 
acid  solution,  and  distil  200  cc,  using  a  spiral 
dephlegmator  of  oonsiderable  length.  The  dis- 
tillate IS  filtered,  and  the  soluble  acids  titrated. 
The  Insoluble  acids  in  the  condenser  tube  and 


flask,  and  on  the  paper  are  also  dissolved  in 
alcohol  and  titrated.  They  found  that  pure 
butters  yielded  from  4-79  to  6-01  p.c.  of  soluble 
volatile  aoids  (as  butyrio  acid)  and  0*5  to  0'87 
p.a  of  insoluble;  while  cocoa-nut  fat  gave 
1*15  to  l-27p.c.  soluble,  and  3-01  to  3-63  p.c. 
insoluble.    They  determine  the  foUowing  ratios : 

insoL  vol.       ,^^      ^  ,   ,    ^ 

for  genuine  butter,  and  250-3  to  282-3  for  cocoa- 
nut  fat. 

Vandam  (Analyst,  1901,  26^  320)  determined 
the  ratio  between  the  total  fatty  acids  soluble 
in  60  p.c.  alcohol,  and  those  soluble  in  the  alcohol 
but  insoluble  in  water.     Robin  (Oompt.  rend. 

1906,  143)  practically  applies  the  same  principle 

in  his  method.    He  found  that  the  ratio  *^^' 

iOl. 

X  10  was  8-3  to  12-7  butter,  232  for  margarine, 
and  226  for  cocoa-nut  fat.  Shrewsbury  and 
Knapp  (Analyst,  1910,  35,  385)  remove  the  aoids 
solubie  in  water,  and  then  determine  the 
solubility  of  the  remaining  fatty  aoids  in  dilute 
aioohoL  They  flnd  a  solubility  figure  of  28  for 
butter  and  163  for  cocoa-nut  fat.  It  has  been 
shown  (Caldwell  and  Hurtley,  Analyst,  1909, 
34,  274)  that  laurio  and  mynstic  acids  are  the 
chief  constituents  of  cocoa-nut  fatty  aoids,  but 
that  these  aoids  are  only  present  to  a  dight 
extent  in  butter;  and  these  processes  are 
therefore  based  upon  the  solubility  in  60  p.c 
alcohol  and  insolu  bility  in  water  of  these  acids. 
Fendler  (Zeitsch.  Nahr.  Gtonussm.  1910,  19,  544 ; 
Analyst,  1910,  35,  355)  has  a  similar  process. 
Av^-Lallemant    (Zeitsch.    Nahr.    Genussm. 

1907,  14,  317)  precipitotes  the  neutralised, 
alcohol-free. soap  solution  with  barium  chloride, 
and  determines  the  baryta  values  for  the  soluble 
barium  salts,  and  for  the  msoluble  barium  salts. 
He  finds  that  normal  butter  has  insoluble  baryta 
value  of  247  to  251,  and  soluble  baryta  value  of 
50  to  65.  The  value  [insoL  ~(200+ioluble)]  is 
negative  for  butter,  whereas  other  fats  have  a 
pjMitive  value  not  less  than  39.  {8u  also 
£!ritzsche,  Zeitsch.  Nahr.  Qenussm.  1907, 14, 329.) 

Ewers  {ibid.  1910, 19,  529)  proposes  a  method 
depending  upon  the  different  solubility  oi  the 
magnesium  salts  of  the  fatty  aoids,  and  on  the 
varjring  solubility  in  petroleum  spirit  of  the 
fatty  acids  from  the  soluble  magnesium  salts. 

Various  methods  have  bem  proposed  to 
distinguish  between  oocoa-nut  fat  and  butter 
fat  by  means  of  the  solubilities  of  the  silver 
salts  of  the  distilled  aoids  In  the  Reichert- Wolhiy 

Srocess  (K*  Jenson,  Analyst,  1905,  30,  396; 
.  Jenson,  Zeitsch.  Nahr.  Genussm.  1905,  10, 
265  ;  Kirsohner,  ibid.  1905,  9,  65 ;  Wijsman  and 
Reijst,  ibid.  1906,  11,  267;  Dean,  Ann.  Chim. 
anaL  1906,  11,  121).  Of  these,  the  method  of 
Kirschner  has  been  much  used  in  this  country  in 
connection  with  the  Reichert- Wollny-Polenske 
process.  As  it  gives  a  measure  of  the  amount  of 
Dutvric  acid  present,  and  eliminates  the  reading 
in  we  ordinarv  R.  W.  process  due  to  the  presence 
of  other  soluble  volatile  acids,  it  is  of  special 
value  for  the  detection  in  butter  of  margarine 
mixtures  containing  cocoanut  or  palm-kemd 
fats.  The  Kirschner  process  is  carried  out  as 
follows:  To  the  100  c.o.  which  have  been 
neutralised  with  baryta  for  the  R.W.  No. 
0*5  gram  of  AggSO^  is  added,  «id  after  standmg 


708 


BUTTER. 


lor  i  ]iour  with  ocoasional  shaking,  the  liquid  is 
filtered  through  a  dry  paper.  100  0.0.  are  taken ; 
35  C.C;  water,  10  0.0  of  dilute  H1SO4  (as  in  the 
Polenske  method),  and  a  piece  of  aluminium 
wire  are  added ;  and  the  distillation  carried  out 
as  before,  110  ac.  being  oolleoted  in  20  minutes. 
100  C.C.  are  titrated  and  the  Kirschner  number 
obtained  as  follows  : — 

^_      121    100+y 
^""*^100^    100. 

(xbs titration  value  of  100  c.o.  less  blank.) 
(y= number  of  c.c.  of  baryta  solution  used  in 
titration  of  original  R.W.  No.) 
Bolton  and  Revis  (Analyst,  1911  333)  and 
Bolton,  Richmond,  and  Revis  (Analyst,  J  912, 
183)  give  Uie  results  for  a  number  of  mixtures, 
and  formule  and  curves  for  the  calculation  of 
the  amount  of  cocoanut  or  butter-fat  present. 
They  suggest  the  following  table  for  the  re- 
lation between  the  Kirschner  and  Polenske 
numbers : — 


KirschiMir 

Polenske 

20 

1-60 

22 

210 

24 

2-65 

26 

3-20 

Cranfield  (Analyst,  1915, 441)  gives  the  R.W., 
Kirschner,  and  Polenske  values  for  a  laige  numbcf 
of  butters  analysed  at  the  Midland  Agricultural 
and  Dairy  College,  showing  similar  relations 
between  we  Kirschner  and  Polenske  figures. 

Bolton*  Richmond,  and  Revis  point  out  that 
if  an  allowance  of  :kl  is  taiade  in  the  Polenske 
value  corresponding  to  any  particular  Kirschner 
value,  the  presence  of  less  than  5  p.c.  of  cocoanut 
fat  will  cause  the  Polenske  value  to  faH  outside 
the  limit,  except  in  cases  of  special  feeding  of 
oows. 

Dons  (Zeitsch.  Nahr.  Qenussm.  1908,  15.  75) 
has  modified  the  process.  The  mixed  fatty 
acids  are  treated  with  water  to  remove  the 
soluble  portion.  Oapvlic  acid,  which  remains 
behind  with  the  insoluble  acids,  is  removed  by 
distillation,  and  estimated  in  tiie  distillate  by 
pedpitation  with  nlver  nitrate  solution.  Pure 
Dutter-fat  gives  a  value  1*6  to  2-0  and  ooooa-nut 
fat  5-3. 

Juckenaok  and  Pastemack  (Zeitsch.  Nahr. 
Qenussm.  1904,  7,  193)  proposed  to  determine 
the  presenoe  of  cocoa-nut  oil  in  butter  from  the 
relationship  between  the  Reioheit  •  WoUny 
number  and  the  saponification  value.  They 
point  out  that  aooording  to  the  formula  [RW. 
— (sapon.  value— 200)]  butter  fluctuates  between 
—8-5  and  +4*25.  For  cocoa-nut  oil  its  value  is 
—47.  Harris  (Analyst,  1906,  31, 355)  has  shown 
that  the  method  of  reasoning  suggested  is  of 
no  value  for  small  admixtures  of  coooa-nut  fat 
with  butter. 

Paal  and  Amberger  (^csch.  Nahr.  Qenussm. 

1909,  17,  23)  distU  separated  solid  fatty  acids  in 
a  current  of  steam  in  special  flask,  and  precipi- 
tate the  cadmium  salts  in  distillate. 

.  HanuS  {t^id.  1907,  13,  18)  and  Hanus  and 
atekl  {ibid,  1908,  15,  577)  and  Fendler  {ibid, 

1910,  19, 644)  nropose  methods  based  upon  the 
distillation  of  tke  ethyl  esters  of  the  fatty  acids. 
Fendler  prepares  the  esters  after  the  manner  of 
Heoriques  (Analyst,  1898,  23,  181)  and  oolleots 
the  esters  boiling  below  300*.    This  fraction 


would  include  the  ethvl  esters  of  the  acids  up  to 
and  indnding  myristic  acid.  The  volume  in 
the  case  of  butter  ranges  from  2-5  to  6-1 ;  ooooa- 
nut  fat,  40  to  42 ;  and  lard,  0-5  to  1*1  e.a 

CSald^^  and  Hurtley  (Lc)  state  that  tmaU 
quantities. of  ooooa-nut  fat  oan  be  detected  by 
tne  fractional  distillation  in  a  high  vaouom  of 
the  f  flatty  acids. 

(Jb)  The  foregoing  tests  for  the  deteotioa  of 
the  adulteration  of  butter-fat  are  based  upon  the 
disturbance  of  the  ratio  existing  in  normal  or 
aventfe  butter-fat  between  the  proportions  of 
solubfo  and  insoluble  aoids.  It  nas,  however, 
been  shown  that  special  feeding  may  affect  this 
relationship  and  produce  butter  giving  abnormal , 
results.  Uncertainty  as  to  the  conclusions  to 
be  drawn  may  be  removed  if  direct  evidence  is 
obtained  from  the  applioatioD  of  specific  tests. 
The  following  qualitative  tests  may  be  applied  :— 

PhytotUrot  (est  for  deUttion  of  vegHable  faU 
(B5mer,  Zeitsch.  Nahr.  Qenussm.  1901,  4,  1070. 
and  1902,  5,  1018).— The  abeolnte  alcohol 
extract  of  the  unsaponifiable  matter  from  100 
grams  of  fat  is  treated  with  acetic  anhydride, 
the  excess  of  which  is  removed,  and  the  acetates 
dissolved  in  alcohol,  crystallised,  and  recrystal- 
lised  several  times.  C9bolesteryl  acetate  mAtB  at 
113-5*  to  114-5*,  Tdiile  the  melting-point  of 
Phytosteryl  acetate  is  about  129*.  If  tiie  melt- 
ing-point  of  the  mixed  aoetates  from  the  sample 
under  examination  is  between  116*  and  117*,  it 
is  probabhr  adulterated  with  vegetable  fat;  if 
above  ll^t  vegetable  fat  is  certainly  present. 
The  test  is  not  of  value  if  paraflbi  wax  is  also 
present. 

Hink$*  tea  for  cocoa-md  foA  (Analyst*  1907, 
32,  160). — 5  ao.  of  the  fat  are  dissolved  in 
10  CO.  of  ether,  and  the  solution  cooled  in  ioe. 
After  half  an  hour,  it  is  rapidly  filtered,  the 
ether  evaporated  from  the  filtrate,  an4  the  fatty 
residue  dissolved  in  96  p.a  (voL)  aloohoL  The 
solution  is  oooled  to  5*  for  15  minutes,  filtered 
rapidlv,  and  the  filtrate  oooled  to  0*.  The 
deposit  which  separates  at  this  temperature  is 
then  examined  on  a  oold  dide  under  a  power 
of  about  250.  Butter  fat  yields  a  deposit 
of  round  granular  masses ;  ooooa-nut  fat*  fine 
needle-shaped  crystals ;  and  miztores  of  butter 
and  cocoa-nut  fat,  fine  feathery  nyBtalB  attached 
to  the  granular  butter  masses.  The  test  is 
capable  of  deteoting  5  p.0.  of  ooooa-nut  fat  in 
butter  fat. 

Badouin  tutfof  M&am4  oil.— ^  ae.  of  the  fat 
are  mixed  in  a  tube  with  5  a.a  of  HCl  (>p^gr- 
1-19)  and  0-1  o.a  of  a  2  p^a  furfural  solution. 
The  mixture  is  well  shaken  and  allowed  to  stand. 
The  aqueous  layer  which  separates  asBomea  a 
reddish  colour  in  presenoe  of  sesamtf  oiL  Butters 
ooloured  with  some  aniline  dyes  give  with  hydro* 
ohlorio  acid  a  pink-to- violet  oolooratlon,  and  in 
such  a  oase  the  aoid  and  fat  mixture  must  be 
heated  until  colourless  before  the  additioii  of 
the  furfural  solution. 

Haiphm  tetlfor  coUon  9ud  oH — 5  &&  of  the 
fat  are  dissolved  in  5  c.a  of  amjd  alcohol,  1  && 
of  a  solution  of  sulj^ur  in  oarbon  disulpliide  is 
added,  and  tiie  mixture  heated  for  20  miniitea 
at  105*  in  a  brine-bath.  A  red  ookMnmtion  is 
produced  in  presenoe  of  ootton-seed  oiL  The 
ohropiogenetio  substanoe  may,  however,  in 
exioeptional  cases,  be  oommunkated  to  batter  by 
feedmg  oows  with  cotton  cake ;  and  a  positive 


BUTTER. 


709 


reaction  miut  be  confirmed  by  other  data  of 
the  examination. 

(e)  The  apecifio  gravity  and  the  Zein  reading 
should  be  taken  ami  oonsideied  in  conjonotion 
with  and  reUtion  to  the  data  for  the  BeiohaEt- 
WoUny  nnmbeTp  saponification  and  iodine 
valnee. 

Of  other  physical  methods  there  may  be 
mentioned : 

VakniaUsi, — 3  co.  of  fat  are  dissolved  in 
an  equal  volume  of  g^ial  acetic  acid,  and  then 
allowed  to  cool  while  being  stirred  with  a  ther- 
mometer. Immediatelv  a  turbidity  is  noted*  the 
temperature  is  read.  A  modification  introduced 
by  Jean  is  to  measure  the  volume  of  acid  dissolved 
in  the  fat  at  60*^.  (For  recent  investigation  oi 
factors  affecting  the  Valenta  test,  itee  ^yer  and 
Weston,  Analyst,  1918, 43,  3.) 

Crismer  teat. — This  method  is  an  official 
one  in  Belgium.  0*6  co.  of  melted  fat  and  1  c.c. 
of  absolute  alcohol  are  placed  in  a  tube  fitted 
with  cork  and  thermometer,  the  bulb  of  which 
dips  into  the  liquid.  The  tube  is  gently  heated 
inmde  a  laiger  tube  until  the  liquid  becomes 
homogeneous.  It  is  then  allowed  to  cool,  and 
the  temperatuie  noted  when  turbidity  appears. 
This  point  is  the  critical  temperature  of  dis- 
solution (Crismer,  Analyst,  1897,  22,  71). 
Vandam  ha?  shown  how  the  alcohol  used  in  the 
test  may  be  standardised  by  means  of  petroleum 
spirit  (Ann.  dee  Falsifications,  1919,  20D). 

Butter  fat  gives  a  result  varying  from  50*6  to 
67,  whilst  margarine  has  a  value  over  66  if  it  is 
composed  of  animal  fat,  and  under  60  if  prepared 
from  vegetable  fat  The  fat  must  be  nee  from 
moisture  and  quite  clear,  and  can  generally  be  so 
obtained  by  filtration  in  a  hot-water  oven 
through  a  dried  filter  paper.  The  Crismer 
values  of  other  UiiB  are  as  follows :  sesam6  oil, 
67*6 ;  almond  oil,  64 ;  cotton  seed  oil,  61*6 ; 
arachis  oil,  67*6;  olive  oil,  66;  cacao  butter, 
47,  tallow,  34*6 ;  lard,  76-77 ;  pahn  oU,  22 ; 
oocoanut  oil,  16-19*6;  palm-kernel  oil,  13*5 
(Stewart,  J.  State  Med.  1918, 26, 312). 

3.  Biamlnatton  for  DreienrativflB.— (a)  Borom 
ecmpounds.  Boric  acia  or  borax  is  detected 
by  moistening  a  strip  of  turmeric  paper  (filter 
paper  soaked  m  an  alcoholic  solution  of  curcuma 
and  dried)  with  a  drop  of  water  squeezed  from 
the  butter,  or  with  the  aqueous  layer  obtained 
on  melting  the  butter.  The  paper  is  then  dried. 
Free  boric  acid  ^ves  a  pink  colour  changed  to 
sieen  with  alkali.  For  oorax  a  drop  of  diluto 
nydrochloric  acid  must  be  added  to  the  paper 
before  drying. 

The  boric  acid  is  estimated  by  Richmond  and 
Harrison's  method  (Analyst,  1902,  27, 170)  or  by 
washing  the  butter  in  a  separator  witii  hot 
water,  evaporating  the  aqueous  portion  aftor 
addition  of  soda,  incinerating,  and  proceeding  as 
in  Thomson's  process. 

A  method  suitable  for  rapid  determinations 
is  as  follows  :  10  grams  of  butter  are  shaken  in  a 
separator  with  20  c.c.  of  hot  water  and  10  ac  of 
decinormal  sulphuric  acid.  The  aqueous  layer  is 
run  off  after  a  few  minutes,  and  the  fat  washed 
twioe  more  with  small  quantities  of  hot  water. 
The  mineral  acid  in  the  combined  water  extracto 
is  then  neutndiBed,  with  laomoid  as  indicator. 
2  grams  of  mannito  are  now  added,  and  phenol* 
phthaleTn.  Decinormal  soda  is  then  added  until 
pink  colour   is   pei^nanent.    The   quantity  of 


soda  used  after  the  solution  was  nautral  to 
laomoid  indicates  the  proportion  of  borio  acid 
present.  A  control  experiment  should  be 
oairied  out  with  pare  butter  and  indicators. 

The  Oommittee  on  Preservatives  in  Food 
recommended  that  borax  of  borio  acid  should 
be  the  only  preservative  allowed  in  butter,  and 
that  the  quantity  should  not  exceed  0-6  p.c. 
calculated  as  Ixnic  acid. 

(6)  FormaUn  is  detected  by  the  application 
of  Hehner's  test  (Richmond,  Analyst^  1896^  21, 
92).  A  little  milk  is  added  to  the  aqueous  layer 
from  mdted  butter,  and  the  mixture  poured  on 
to  the  surface  of  sulphurio  add  containing  a 
trace  of  ferric  chloride.  In  presence  of  formal- 
dehyde a  blue  ring  appears  at  the  juncture  of 
i^e  aqueous  and  acid  layers. 

(c)  Fluorides,  fluorine  is  detected  bv  eva- 
poratinff  the  aqueous  portion  rendered  alkaline 
from  about  30  grams  <rf  butter,  incinerating, 
and  heating  the  ash  in  a  platinum  crucible 
with  strong  sulphurio  acid.  The  crucible  is 
covered  vith  a  watch-daas  coated  with  wax 
through  which  a  mark  or  design  has  been  soratohed 
with  a  fine  instrument.  In  presence  of  fluoride 
the  glass  will  be  etehed. 

O.  and  C.  W.  Hehner  (Analyst,  1902,  27, 
173)  indicate  how  to  remove  the  boric  add  if 
present  before  testing  for  fluQridei 

(d)  Benwic  acid  and  hemoaies,  10  grams  of 
butter  are  heated  for  some  time  with  alcohol 
acidified  with  diluto  sulphurio  aoid.  The 
alcoholic  extract,  after  dilution  with  water,  is 
extracted  with  ether  in  a  separator.  The  ether 
solution  is  then  shaken  with  diluto  ammonia, 
and  the  ammoniacal  extiact  evaporated  to 
dryness  in  a  porcelain  dish.  The  residue  is 
dissolved  in  water,  just  acidified  with  acetic 
add  to  ensure  that  no  free  ammonia  remains, 
and  a  drop  of  ferrio  chloride  solution  added. 
Benzoic  acid  ^ves  a  buff-coloured  predpitete. 

(«)  Salieyhc  acid,  A  portion  of  the  aloohoUo 
solution  prepared  for  benzoic  add  is  testoJ 
direotiy  with  a  drop  of  ferric  chloride  solution. 
Salicylic  acid  gives  a  violet  colour. 

if)  Richmond  (Analyst,  1908,  33,  116) 
pointe  out  that  f ormio  add  and  glucose  are  also 
used  as  preservative  agents. 

Cokmrlng  mAtten.  The  colour  of  butter 
prepared  without  addition  of  artificial  colouring 
matter,  varies  acoordinf;  to  the  food  of  the  cows. 
The  vellow  colour  is  due  to  the  yellow  pigmente 
which  accompany  chlorophvU  in  all  green  planto, 
of  which  carotin  and  xanthophyU  are  the  most 
important.  The  pigment  is  not  made  in  the 
animal  body,  but  is  derived  entirely  from  the 
food ;  fireeh  green  grass  contains  most^  and  gives 
the  highest  coloured  milk  fat.  There  is  a 
difference  in  breed,  but  this  is  not  so  importont 
a  factor  as  supposed  (Palmer  and  Eckles,  J.  Biol. 
Ghem.  1914,  17,  191).  (For  the  detection  of 
carotin  in  butter,  see  J,  Ind.  Ens.  Chem.  1916, 
614. )  Winter  butter  from  stall-fed  cows  is  nearly 
odourless.  Gdlouring  matter  is  frequentiy 
added  to  butter  during  manufaoture.  Annatto, 
turmeric,  carrot  juice,  saffron,  marigold,  safilowei* 
and  anilme  dyes  are  among  the  artifidal  colours 
emi^oyed.  A^itotion  of  the  butter  fat  with  hot 
alcohol  will  sive  an  indication  whether  colour 
has  been  adoed.  Oomelison  (J.  Amer.  Ghem. 
Soo.  1908,  80, 1478)  shakes  thoroughly  10  mms 
of  melted  fat  with  10  to  20  grams  of  glacial 


710 


BUTTER. 


acetic  acid  at  about  35^  The  acid  layer  im 
drawn  off  and  tested  with  variooB  reaffonts  for 
the  detection  of  aniline  and  Tegetafie  dyes. 
Leeda  (Analyst,  1887,  160)  has  aim  proposed  a 
scheme  .for  identification  of  dye. 

Annatto  and  aco-  dyes  may  be  rapidly 
tested  for  as  follows :  5  cc.  of  melted  fat  are 
plaoed  in  each  of  two  test-tubes.  To  one  5  c.o. 
of  hydpochlorio  acid  are  added,  and  the  mixture 
shaken.  Azo-  dyes  will  impart  a  reddish  colour 
to  the  acid  layer.  To  the  second  tube  add  6  o.a 
of  ether,  and  shake,  and  then  6  o.a  of  10  p.o. 
potadi  solution.  Shake  and  allow  to  separate. 
If  annatto  is  present,  the  alkaline  layer  will  be 
coloured  yellow.  To  confirm  the  annatto,  the 
alkaline  liquid  is  withdrawn,  evaporated  to 
dryness,  and  touched  with  a  drop  ik  sulphur^ 
acid.  Annatto  gives  an  indigo-blue  to  violet 
colouration. 

Crampton  and  Simons  (J.  Amer.  Ghem.  Soc 
1906,  27,  270)  point  out  the  use  of  palm  oil  as 
a  colouring  substance,  and  its  detection  by  the 
Halpheu  and  Liebermann-Storch  methodiii  for 
rosin  oiL 

The  further  examination  of  the  butter  is 
concerned  witii  its  flavour,  appearance,  rancidity. 
As  regards  rancidity,  the  quantity  of  free  acid 
dissolved  in  alcohol  may  be  ascertained,  but  tliia 
is  frjMjuentiy  no  guide  to  or  measure  of  the 
rancidity,  which  is  best  judged  by  smell  and  taste. 

The  definition  of  *  butter'  in  the  Margarine  Act, 
1887  (60  &  61  Vict.  c.  20)  is  as  follows :  *  The 
word  **  butter "  shall  mean  the  substance 
usually  known  aa  butter,  made  exclusively  from 
milk  or  cream,  or  both,  with  or  without  salt  or 
other  preservative,  and  with  or  without  the 
addition  of  colouring  matter.' 

The  Butter  and  Margarine  Act,  1907  (7  Edw. 
7,  e.  21)  describes  milk-blended  butter  as  *  any 
mixture  produoed  by  mixinff  or  blending  butter 
with  milk  or  cream  (other  than  condensed  milk 
or  cream).'  By  ths  provisions  of  this  Act 
milk-Uended  butter  may  contain  a  maximum 
of  24iko.  of  water. 

'  Renovated '  or  *  process '  butter  is  a  pro- 
duct mainly  of  the  United  States.  It  is  demied 
by  Act  of  OoDgrees  as  *  butter  which  has  been 
subjected  to  any  process  by  which  it  is  melted, 
clarified,  or  refined  and  made  to  resemble 
genuine  butter.'  Butter  which  is  unsaleable 
through  rancidity,  mould  growths,  or  other 
oauses,  is  melted,  and  the  oil  separated  from  the 
curd  and  water.  The  oil  is  then  aSrated  by 
*  blowing'  with  air,  and  afterwards  emulsified 
with  fresh  milk  inoculated  with  a  bacterial 
culture.  It  is  then  churned  and  worked  as  for 
ordinary  butter. 

Crampton  (J.  Amer.  CSiem.  Soc.  1903,  26, 
368)  gives  details  of  analyses  and  tests.  Several 
similar  processes  have  been  patented  here,  and 
in  some  factories  the  melting  aad  purification 
of  inferior  butter  is  now  carried  on.  Hence 
such  products  might  contain  or3rstalline  fat, 
and  the  microscopical  examination  is  now  of  no 
value  aa  a  test  for  foreign  fat. 

*  Factory '  butter  is  butter  which  has  been 
reworked  or  blended  with  other  butter;  by 
'dairy'  butter  is  understood  butter  made  at 
the  farmer's  homestead,  whether  from  idiole  milk 
or  cream;  and  the  term  'creamery'  butter  is 
generally  applied  to  butter  made  from  cream 
separated  by  centrifugal  force  from  the  mixed 


milk  of  a  number  of  herds  in  premises  specially 
utilised  for  the  purpose  («ee  the  Report  of  the 
Oommittee  of  the  Department  of  Agriculture  for 
Ireland,  on  the  Irish  Butter  Industry,  Od.  6092, 
1910). 

In  hot  countries,  owing  to  the  rapid  decompo- 
sition of  ordinary  butter,  the  clarified  fat,  nee 
from  water  and  curdy  is  propared  for  sale,  aa 
* schmelzbutter,'  'ghee.* 

Trimen  (Analyst,  1913,  242)  has  described 
the  preparation  of  '  Samna '  or  "  Samn,'  the 
Eg^tian  product  oorreijponding  to  the  '  ghee  * 
of  India.  Whole  milk  is  churned  in  goatskins 
until  the  butter  (zibda)  forms.  The  zibda  is 
collected  from  the  villages  by  the  samna  makers, 
who  heat  in  lanre  pans  until  it  melts»  the  samna 
being  poured  on  from  the  water  and  curd.  Its 
keeping  properties  are  much  superior  to  those  of 
butter,  and  it  may  be  used  years  after  it  has  been 
made.  It  is  pale  yellow  in  colour,  poosesciny  a 
smell,  sometimes  cheeey,  sometimee  acid,  ne- 
quently  rancid,  and  always  unpleasant  to 
European  ideas.  Both  Eeyptian  samna  and 
Indian  ehee  are  lugely  made  from  buffcJo  milk, 
and  unlees  artificially  coloured  are  very  pale. 
Syrian  samna  is  generally  believed  to  be  made 
from  sheep  and  goats'  nulk.  Trimen  gives  the 
results  of  analysis  of  a  number  of  samples.  (For 
otiier  analyses  of  ghee,  see  Bolton  and  Revis, 
Analyst,  1910,  343;  ibid.  1911,  392;  and 
Kesava  Menon,  J.  Soc  Chem.  Ind.  1910,  1428). 

O.  S. 

BUTTERIHB  o.  MAROABm. 

BUTTER  SUBSTITUTES  v.  MABaABiNE. 

BUTTER  SURROGATE  v.  Mabqasinb. 

BUTTER,  VEGETABLE.  A  greasy  substance 
expressed  from  the  kernel  of  the  Baasta  bulyraeea 
(Boxb.),  a  native  of  North  India.  This  grease 
is  said  to  make  excellent  soap.  Shea  butter  is 
obtained  from  the  Butyrmpermum  Parkii^  of 
West  Africa,  and  has  been  used  in  making 
candles  and  soap.  The  butter-tree  of  Sierra 
Leone  is  the  Ptntadesma  btUyracea  (Subine),  tiie 
fruit  of  which  yields  much  grease,  and  is  eaten 
by  the  negroes  (v.  Oiub  and  Fats). 

BUTTER  YELLOW.  Btfueneazodimdh^ 
aniUne  G,H,-N : N*G;H4N(GH.),.  A  yeUow 
colourine  matter  (m-P*  116*) ;  insoluble  in  water, 
soluble  m  dilute  H(X  with  red  colour ;  soluble 
in  fats.  Used  for  colouring  butter  (Witi.  Griess. 
Ber.  1877, 10,628)(e.Azo-  ooLovBiHa  icattxbs). 

BUTTERS,  MINERAL.  A  term  formerly  ap- 
plied to  several  of  the  metallic  ohloridea,  c^. 
chlorides  of  antimony,  tin,  bismuth,  line,  fte. 

BUTTL.  A  univalent  radica  yielding  four 
isomeric  mono-  derivatives : 

(1)  GH,'CH,*CH,-CH,X  (normal) ; 

(2)  CH,*CH.-CHX-CH,  (secondary) ; 
(8)  (CH,),CH-GH,X ; 

(4)  (CH,).OX  (tertiary). 

BuTTL  OoMPonirDS. 

BatylaleohoL  Tetiyl  alcohol  CtH^OH.  AD 
the  four  possible  bodiea  corresponding  to  this 
formula  are  known. 

I.  Normal  butyl  alcoM:  bttUanol;  prop^ 
embinU  CH.OH.-CHg-CH.OH ;  b.p.  117*42* 
(corr.)  (Thorpe  and  Biodger,  PhiL  Trans.  1894, 
186,  iL  636 ;  Briihl,  Annalen,  203,  16) ;  sp.gr. 
0''«0-8233,  20''b0-8109,  40''»0  7994,  9%'T  -* 
0-7738,  2074°=0-8099  (B.) ;  m  « ■»  1-89909.  moL 

refraotk)n>»86-46   (B.).    Occurs  in  the   heavy 


BUTYL. 


711 


oil  of  Cognac  brandy  to  the  extent  of  49  p.c. 
Is  nol  formed  in  the  fermentation  of  sugar 
rarodnoed  by  elliptical  yeast  (CSlaadon  and  Morin, 
Chem.  Soc  Trans.  1887,  ii  714).  Is  produced 
by  the  action  oi  sodium  amalgam  upon  butyryl 
chloride  and  butyric  acid  (Saytzeff,  Zeitsch. 
Chem.  1870, 108;  lannemann,  Annalen,  161, 178). 
Also  by  the  fermentation  of  glycerol  by  BaciUus 
butylieua  and  certain  other  bacteria  in  presence 
of  calcium  carbonate  and  Tarioua  foodstuffs, 
e.g.  ammonium  tartrate ;  the  yield  amounts  to 
9  p.c.  of  the  glycerol  usecL  Butyric  acid  and  a 
little  ethyl  alcohol  are  also  formed  (Fitz,  Ber.  9, 
1318  ;  Vigna,  Ber.  16,  1348).  Is  also  produced 
by  the  action  of  nascent  hydrogen  (iron  and 
acetic  acid)  upon  crotonaldehvde  and  trichloro- 
butyraldehyde  (Lieben  and  ^eisel,  Monatsh.  1, 
825,  842). 

Beyerinck  has  shown  that  the  BaciUua 
btUylieus  of  Fitz  (Ber.  1882,  867)  is  in  reality 
the  butyric  ferment.  The  true  butylic  ferment, 
Qranvlobacler  butylicum,  has  been  isolated  in  a 
pure  condition,  and  an  account  of  the  whole 
fermentation  process  is  given  (J.  Soc.  Chem.  Ind. 
1894,  167;  ibid,  969).  {See  also  Emmerling, 
Ber.  1896,  2726 ;  1897,  451 ;  Bnchner  and 
Meisenheimer,  Ber.  1908,  1410.) 

Properties. — Colourless  liquid,  soluble  in  12 
parts  of  water,  from  which  solution  it  can  be 
separated  by  means  of  calcium  chloride.  Soluble 
in  concehtrated  hydrochloric  acid ;  is  readily 
oxidised  to  butyric  acid.  Fused  zinc  chloride 
abstracts  water,  and  yields  /3-butylene  and 
smaller  amounts  of  normal  butylene  (Le  Bel 
and  Greene,  Amer.  Chem.  J.  2,  24). 

Bromine  acting  on  fi-butyl  alcohol  yields^ 
with   some  dlfficmty,  mono-brombutaldehyde, 

b.p.  235**  (l:tard,  Compt.  rend.  114,  753).  The 
action  of  aluminium  amalgam  on  the  butyl 
alcohols,  producing  liquid  aluminium  alkoxidea^ 
has  been  studied  by  Tistshenko  (Chem.  Soo. 
Abstr.  1899,  L  408). 

2.  l$o-buiyl  alcohoh  ieopropyl  cairbinol» 
arhydroxyfi-meAylpropane{CHt)fia'CEfiB,h.^, 
108*4''  (Linnemann,  Annalen,  160, 238),  107*5''  at 
756  mm.,  Michael  and  Zeidier  (Annalen,  1912, 
393,  81),  107*6''  (corr.),  Thorpe  and  Rodger 
(PhiL  Trans.  1894,  185,  A,  538) ;  sp.gr.  0*7265 
at  106*674'*  (Schi£F,  Annalen,  220,  102),  0*8168 
at  0*  (L.),  0*8069  at  16715*,  0*8008  at  25725* 
Perkin  (Chem.  Soc.  Trans.  1884,  468);  sp. 
heatsO-686 ;  molecular  rotation =4*936  at  17*7* 
(P.) ;    molecular  refraction=35'41 ;  /i^sl*4007. 

Sp.gr.    of   aqueous   solutions    (Duclaux,    Ann. 
im.  Phys.  [5113,91): 


6 


10 


Percentage  of  alco-\n.<' 
hoi  (by  VOL)       r 

^^solution  atl^"*}^  ^^  ^"^^  ^'^^^  ^"^^"^^ 
Occurs  in  fusel  oil  from  potatoes  and  beet 
(Wurta,  Ann.  Chim.  Phys.  [31  42,  129),  and 
combined  with  angelic  and  MODutprrio  acids  in 
Roman  oil  of  chamomile  (Kobig,  Annalen, 
195,  96). 

Preparation. — ^By  the  action  of  sodium 
amalgam  and  water  unon  jB-chlorMobntyl  alcohol, 
which  results  from  tne  action  of  hypochlorous 
acid  upon  isobut^lene  (Butlerow,  Annalen,  144, 
24).  Is  formed  m  small  quantity  by  the  action 
of  elliptioal  yeast  upon  sugar  or  glycerol 
(Claudon  and  Morin,  Cheio.  Boo.  Trans.  1887,  | 


ii  7 14).  By  the  reduction  of  tiiobutyric  aldehyde 
with  sodium  an^lgam  (Linnemann  and  Zotta, 
Annalen,  162,  11). 

Properties. — Colourless  liquid,  soluble  in 
10*5  parts  of  water,  from  which  calcium  chloride 
causes  it  to  separate.  Smells  like  fusel  oiL 
Is  oxidised  by  chromic  acid  into  Mobutyric  acid, 
acetic  acid,  carbon  dioxide,  acetone,  and  other 
products  (Kramer,  Ber.  7,  252 ;  Schmitt,  ibid. 
8,  1361).  Zinc  dust  yields  water  and  iso' 
butvlene  ( Jahn,  ibid.  13,  989). 

Treated  with  iodine  and  aluminium,  alumi- 
nium triMobutoxlde  Al(C4H.O).  is  formed.  It  is 
a  liquid  which  may  be  distuled  in  tfoeuo  (Glad- 
stone and  Tribe,  Chem.  Soo.  Trans.  1881,  6). 

Isohviiyl  alcohol  may  be  catalytically 
oxidised  to  Mobutyl  aldehyde.  The  vapour  of 
the  alcohol  mixed  with  air,  is  passed  over  warm 
freshly  reduced  copper  spiralB  and  the  products 
collected.  A  yield  of  50  p.c.  is  obtainable  (E. 
Orlow,  J.  Soo.  Chem.  Ind.  1908,  957). 

When  chlorine  is  passed  into  dry  i«obutyl 
alcohol,  and  the  solution  subsequently  heated 
gently,  the  product  can  be  separated  into  two 
fractions,  boiling  at  80*>100'^  and  170*-250*. 
The  lower  fraction  consists  of  dUoTMo&ti/aUe- 
hyde,  boiling  at  90*-91*;  sp.gr.  1*186, 1574*.  It 
combines  with  sodium  hydrogen  sulphite,  and 
when  oxidised  with  alkaline  permanganate  yields 
acetone  and  hydroxyMobutyrio  acid  C(CH,)|OH* 
CO  OH ,  melting  at  78*.  A  t  ermolecular  polyme- 
ride  C^^R^iCSfif,  which  melts  at  107%  is 
obtained  by  shaking  with  strong  sulphuric  acid 
(A.  Brochet,  Compt.  rend.  114,  1538).  If  the 
alcohol  is  kept  cold,  the  chief  product  is  dichiof' 
isobvtyl  oxide  C(CH,),C1*CHC1*0*CH,CH(CH,), 
boiling  at  192'5*/760,  and  of  8p.gr.  1*031, 15*/4*. 
Water  is  without  action  on  this  product  at  low 
temperatures,  but  at  100*  produces  hydrogen 
chloride  and  a-chlorMobutaldehyde  and  ditso- 
butyknonochlorMobutyral  C(CH,),Cl*CH(0C4Hg) 
boiling  at  218*,  and  of  sp.gr.  0*9355,  1574* 
(A.  Brochet,  Compt.  rend.  118,  1280;  v,  abo 
Brochet,  Bull.  Soc.  chim.  1896,  16 ;  ibid.  20). 

When  chlorine  is  led  into  hot  isobutvl  alco- 
hol, ohlon«obutyricMobutyl  ester,  a/9-dionlor»«o- 
butyric  acid,  Mobutyl  ester,  mono-  and  dichlor- 
Mobutyrio  aldehyde,  wobutyric  acid,  oxyiao- 
butyrio  acid,  crotonio  acid  CO,COa,  and  methyl 
chloride  are  produced.  Treating  aqueous  iso- 
butyl  alcohol  with  chlorine  water  produces 
wobutyric  acid,  and  a-chlort«obutyrio  acid 
itfobutyl  ester.  Chlorine  acting  on  odd  dry 
Mobutyl  alcohol  in  the  light  produces  1  : 2- 
dkshlorMobutyl  estei  (Brochet*  Ann.  Chim. 
Phys.  m  10,  363). 

/tfobntyl  alcohol,  when  acted  on  by  bromine, 
readily  yields  Mobutyl  bromide,  mixed  with 
Mobutyl  isobutyrate^  and  bromijobutaldehyde 
(EtarcC  Oompt.  send.  114.  753). 

(For  combinations  and  derivatives  of  tsobutyl 
alcohol,  V.  Gladstone  and  Tribe,  Chem.  Soc 
Trans.  1881,  6;  Pierre  and  Puchot,  Annalent 
163,  274;  and  Hemdl  Monatsh.  2,  208.) 

Z.  Secondary  butyl  alcohol,  2-hydroxybu- 
tone,   meihffi  eAyl  carhinol,    butylene   hydrate. 

^^•^CHOH;  b,p.  99*  at  738*8  mm.  (Lieben. 

Annalen,  150,  114) ;  sp.gr.  0*827  at  0*,  0*810 
at  22*  (L.). 

Formed  by  the  action  of  water  upon  the 
compound  of  zinc-ethyl  and  aldehyde  : 


712 


thus: 


BUTYL. 


CH,CH{C.H.)0Zn(C,H4) 


CH,OH(C,H,)OZnC,H, + H,0 

=C4H,OH+ZnO+C,H, 

(Wagner,  Annalen,  181,  261).  Also  by  acting 
npon  seoondary  butyl  iodide  with  silver  aoetate 
and  saponifying  the  resulting  acetate  by  means 
of  potash.  Normal  butyl  alcohol  may  be 
changed  into  the  secondary  alcohol ;  the  normal 
iodide  is  heated  with  potash,  and  the  normal 
butylene  so  obtained  on  treatment  with  hydri- 
odic  acid  yields  seoondaiy  butyl  iodide  (Saytzeff, 
Zeitsch.  anaL  Ghem.  1870,  327).  It  may  also  be 
prepared  from  the  normal  isomeride  by  treating 
»-butylamine  with  nitrous  acid  (Meyer,  Ber.  10, 
130;  Kanonnikoff  and  Saytzeff,  CSiem.  Soc 
Trans.  1875,  626). 

Properties. — Liquid,  with  strong  odour ;  upon 
oxidation  yields  a  ketone  GtH.*CX)'CH,  (b.p. 
80°),  and  acetic  acid  (Kanonnikoff  and  Saytzeff, 
Ghem.  Soc.  Trans.  1876,  626).  Heated  with 
a  trace  of  hydrochloric,  hydrobromic,  or  hydri* 
odio  acid,  in  a  sealed  tube,  to  240°,  yields  G4H, 
(peeudo-butylene).  It  has  been  separated  into 
its  optical  antipodes  by  R.  Meth  (Ber.  1907, 695) ; 
the  alcohol  has  [a]^,  0-32°. 

i.  Tertiary  butyl  alcohol,  tritneihyl 
cathind  (GHs),G-OH.  A  solul;  m.p.  25-45° 
(De  ForcrancC  Gompt.  rend..  136,  1034);  b.p. 
82*94*  (corr.)  (linnemann,  Annalen,  162,  26) ; 
81-5°-82°  (Perkin,  Ghem.  Soc.  Trans.  1884, 468) ; 
82-25°  (Thorpe  and  Rodger,  Pha  Trans.  1894, 
u.  539).  Sp.ffr.  0-7792  at  37°  (L ) ;  07788  at  30° 
(Butlerow,  Annalen,  162,  229);  0-7864  at 
20°/4°.  0-7802  at  26°/4°  (Bruhl,  Annalen.  203, 
17) ;  0-7836)  at  25°/W,  0-7761  at  35°/35° ; 
molecular  rotation  at  24-3°»5-122  (P.); 
/A^s=l*3924 ;   molecular  refraotiona35-53 ;  crit. 

temp.  =234-9°  (Pawlewski,  Ber.  16,  2634). 

Formed  from  Mobutyl  iodide  by  treatment 
with  acetks  acid  and  silyev  oade  (Linnemann ; 
Butlerow,  Annalen,  168,  143);  also  from  iaO" 
butylamine  by  treatment  with  nitrous  acid,  and 
from  isobutjrl  carbimide  G0-N-G4H4,  by  action 
of  potash  (Linnemann,  Annalen,  162,  12).  Gan 
be  prepared  by  allowing  20  grams  of  tertiary 
butyl  iodide  and  50  grams  of  water  to  stand  in 
contact  for  two  or  three  days  (Dobbin,  Ghem. 
800.  Trans.  1880,  238). 

/«obut^l  alcohol  heated  with  excess  of  hydro- 
chloric acid  yields  a  mixture  of  secondarr  and 
tertiaiy  butyl  chloridea,  and  when  heated  with 
six  Tolumes  of  watei  only  the  latter  is  decom- 
posed, yielding  the  alcohol  and  hydrochloric 
acid  (Freund,  J.  Pharm.  Ghim.  [21  12,  25). 

Pro}wr<te«.— Forma  rhombic  plates  pr  prisms. 
Unites  with  water  to  form  a  liquid  hydrate 
2G4HioO,H,0  (b.p.  80°;  fl|i.gr.  0*8276  at  0° 
(Butlerow,  Annalen,  162,  229).  On  oxkiation 
yields  acetone,  carbon  dioxide,  acetic  acid,  and 
a  small  quantity  of  Mobutyiio  add  (Butlerow, 
Zeitsch.  Ghem.  1871,  485). 

The  existence  of  the  hydrate  G4H,«0,2HaO, 
m,p.  0*,  is  confirmed  by  ciyoBcopic,  density 
and  Tiscosity  determinations  (Pat^n5  and 
Mieli,  AttL  R.  Aooad.  LinceL  1907  (v.),  16,  ii. 
103). 

In  sunlight  it  combines  with  chlorine,  form- 
ing tertiary  butyl  chloride  and  other  substances 
(irOtieppe,  J.  1881,  512). 


Trimeth^l  carbinol  explodes  feebly  when 
treated  with  bromine,  yielding  isAuiylene 
bromide  G(GH,),Br-GH,B>  boiling  at  148° 
(£tard,  Gompt.  rend.  114,  753). 

Tertiary  butyl  alcohol  has  a  slightly  narcotic 
action  when  taken  internally,  and  is  found  in 
the  urine  in  combination  with  glycuronio  acid 
(Thierfelder  and  y.  Mering,  Ghm.  Soc  Abstr. 
1885,  L  1002). 

Niirohiydrozybutanes  may  be  obtained  quanta- 
tatiyely  as  follows:  By  the  action  of  nitromethane 
on  formaldehyde,  in  presence  of  a  little  potassium 
carbonate,  tertiary  nitrotrihydroxybutane 
NO,*(GHsOH)|,  a  white  crystalline  solid,  melting 
at  158°-159°,  is  produced.  Nitroethane  pro- 
duces tertiary  nitrodihydroxybutaneNOa-G(GH  J 
(GH,OH)„  melting  at  139°-140°.  Secondary 
nitropropane  yields  nitroMobutyl  alcohol 
NO,-G(Ke),-GHaOH,  melting  at  82°  (L.  Henry, 
Gompt.  rend.  1895,  121,  210). 

Butyl  bromides.    Tctryl  bromides  G4H,Br. 

1.  Normal  butyl  bromide,  a-bromobutane 

GH,-GH,-GH,-CH,Br ; 
b.p.    99-0*  (corr.)  (Linnemann,  Annalen,    161, 
193^ :    sp.gr.  1-3060  at  0*,  1-2792  at  20°,  1-2571 
at  40°  (Lioben  and  Rossi,  ibid.  158,  161). 

Formed  from  normal  butyl  alcohol  and 
hydrobromic  add  (L.  and  R.  Taboury,  Bull. 
Soc.  chim.  1911  [iy.1  9,  124). 

By  the  action  of  bromine,  a^-dibrombutane 
GAHgBra  (b.p.  166°)  is  formed  (L.). 

2.  Isobutyl  bromide,  a-bromo-B-melhyl 
propane  (GH,)gGH-(nisBr ;  b.p.  92-3^  (corr.) 
(Linnemann,  Annalen,  162,  34) ;  91*3°  (Perkin, 
Ghem.  Soc.  Trans.  1884,  459);  91*7°  (coir.) 
(Thorpe) ;  sp.gr.  1-2038  at  16°  (L.),  1-2722  at 
15°/15°,  1-2598  at  25°/25°  (P.).  Molecular 
rotation=:8-003  at  16-2°  (P.).  From  Mobutyl 
alcohol,  bromine,  and  phosphorus  (Wurta, 
Annalen,  93,  114).  Unites  with  bromine  at 
160°  to  form  G4HyBr,  (L.).  Pure  fsobntyl 
bromide  is  an  unstable  substance,  both  in  the 
liquid  and  gaseous  states,  when  heated. 

3.  Tertiary  butyl  brvmide,  ^^uromo-A-meiky^ 
propane  (GH,).GBr ;  b.p.  72°  at  761-6  mm. ; 
sp.gr.  1-215  at  20°,  1-2020  at  15°/15°,  M892  at 
25°/25° ;  molecular  rotation=8-238  at  17-8°  (P.). 
Formed  when  Mobutyl  bromide  is  heated  to  240* 
(Eltekow,  Ber.  8,  1244).  Also  from  trimelhyl 
carbinol  and  phosphorus  pentabromide  (Rebou, 
J.  1881,  409).  Ifay  also  be  prepared  l^  leadins 
Mobutylene  into  a  solution  of  hydrobimnic  acid 
of  sp.gr.  1-7  (Rooseboom,  Ber.  14,  2396).  Is 
readily  decomposed  at  300°  into  iM>bu^lene 
and  hydrobromic  acid.  Water,  in  the  oold, 
forms  the  alcohol 

Tribronio  teri-butyl  alooM  (brometoiie) 
OjaL^OBr^  ULp.  167°-176°,  forms  iriiite  crystals, 
has  a  camphor-like  taste  and  odour,  is  slowly 
volatile  in  air,  and  can  be  distilled  with  steam 
(Aldrich,  J.  Amer.  Ghem.  Soc.  1911,  33,  386). 
For  pharmacological  properties,  Me  Houghtoa 
and  Aldrich,  Proc.  Amer.  PhysdL  Soc.  19&I). 

4.  Secondary  butyl  bromide,  Mrom- 
buJtane  GH,-GH,-GHBr-CH, ;  b.p.  90°-te*  (V. 
Meyer  and  Muller,  J.  pr.  Ghem.  [2]  46,  183) ; 
obtained  from  secondly  butyl  alcohol  W  the 
action  of  hydrobromic  acid,  and  yields  p  (7)- 
dibrombutane  by  warming  with  iron  and 
bromine. 

For  observations  on  the  course  of  the  intra- 
molecular transformations  of  the  butyl 


BUTYL. 


713 


aad  ohioridiM,  &u  Michael  and  Leopold,  Annalen, 
1911»  379,  263 ;  Michael  and  Zeidler,  Annalen, 
1912,  393,  /81 ;  Michael,  ScharC  and  Voigt. 
T.  Amer.  Chem.  Soc.  1916,  38,  653. 

Butyl  chloridei.     Tetryl    chlorides  CfH,Gl. 

1.  Normal  butyl  chloride,  a-ehlofwUane 

CH,CH,CH,CH,C1 

b.p.  77  96°  (corr.)  (Linnemann,  Annalen,  61, 
197) ;  8p.gr.  0*9074  at  0^  0*8874  at  20*'  (Lieben 
and  Roeai,  ibid.  158,  161) ;  0*9074  at  0"*  (L.), 
0-8972  at  14^  Formed  by  the  action  of  chlorine 
upon  n-butane  ^Pelouze  and  Cahonra,  J.  1863, 
524).  More  easily  by  the  action  of  hydrochloric 
add  upon  n-batyl  alcohol  (Lieben  and  Rossi). 

2.  Isobutjil  ehloridBf  p-metkyl-a'MorprO' 
pane  (CH,).C!H'CHaCl ;  b.p.  68*5''  (Linne- 
mann,  Annalen,  162,  17);  68*5'*-69^  (Perkin, 
Chem.  Soc  Trans.  1884,  451);  69*02"*  (corr.) 
(Thorpe) ;  8p.gr.  0*8798  at  15''  (L.),  0*8953  at  O"", 
0*8651  at  27*8'',  0*8281  at  59''  (Pierre,  Puchot, 
Annalen,  163,  276),  0*8835  at  15''/15^  0*8739  at 
25725"  (P.).  Molecular  rotation  at  21-3"=6*144 
(Perkin).  Formed  by  the  action  of  hydro- 
chloric acid  or  PClg  npon  the  alcohol  (Warts, 
ibid,  93,  113).  By  the  action  of  chlorine,  heza- 
chlorbutane  is  produced. 

Isohutyl  chloride  is  also  prodnced  by  the 
interaction  of  chlorine  and  isobutane  in  difFused 
sunlight  (Mabery  and  Hudson,  Amer.  Chem.  J. 
]9»  245);  and  also  by  treatina  Mobutylamine 
cooled  to  —15*  with  nitrosyl  chloride  (Solonina, 
C9iem.  Zentr.  1898,  ii  887). 

3.  Tertiary  butyl  chloride,  fi-methyUfi- 
ehiarpropane  (CH,),0C1 ;  b.p.  51'*-n52»  (Perkin, 
Chem.  Soc.  Trans.  1884,  451);  sp-gr.  0>8658 
at  0*  (Puchot),  0-8471  at  15715*  0-8368  at 
25V25";  molecular  rotation  at  15* « 6*257 
(Perkin). 

Formed  (1)  by  the  ohlcrination  of  tertiary 
butane  (BuUerow) ;  (2)  by  the  action  of  iodine 
monochloride  upon  Mobutyl  iodide  (Lsnnemann, 
Annalen,  162,  18) ;  (3)  by  the  action  of  hydro- 
chloric acid  upon  isobutyiene  at  100*  (Zalessky, 
Ber.  5,  480 ;  Le  Bel,  Bull.  Soc.  chim.  28,  462) ; 
(4)  by  saturating  trimethyl  carbinol  at  0*  with 
HClgas  (Schramm,  Monatsh.  9,  619). 

Heated  with  five  or  six  vols,  of  water  to  100*, 
the  alcohol  is  produced  (Butlerow,  Annalen, 
144,  33).  Chlorme  in  diffused  daylight,  in  the 
cold,  forms  C4H,a,  (b.p.  106*-107*),  C4H,a, 
and  CtH^a,,  whilst  in  direct  sunlight  CJLtd^ 
(b.p.  in  partial  vacuum  about  115*),  and  other 
products  are  formed  (D'Ottreppe,  J.  1882,  441). 

Tertiary  butyl  chloride  is  also  formed  by  the 
action  of  VCig  on  trimethyl  carbinol  ( Janschenko, 
Chem.  Zentr.  1897,  ii  334).  It  also  results, 
together  with  iwbutyl  chloride  from  the  action 
of  nitrosy]  chloride  on  tertiary  butylamine  in 
xylene  solution  at  —15*  to  —20*  (Salonina, 
ibid,  1898,  ii.  888). 

4.  Secondarybutyl  chloride,  $-chJorobu- 
tone  CH,-CH,-CHa-CH»  Is  produced  by  the 
action  of  nitrosyl  chloride  on  secondary  butyl- 
amine in  xylene  solution  at  —2^*  (Solonina, 
Chem.  Zentr.  1898,  il  888). 

Botyl  cyuifttes.  Only  the  tso-cyanates  have 
been  described. 

1.  Isobufyl  isocyanate,  Isohutyl  oarbi- 
roide  (CH,),Cn*CH.*NCO ;  b.p.  110*  obtained 
by  the  distillation  m  wobutyl  iodide  with  silver 
qyanate  and  sand  (Brauoer,  Ber.  12,  1877). 


2.  Tertiary  butyl  isocyanate 
(CH,),C-N(X) ; 
b.p.  85-5*  (corr.) ;  sp.gr.  0-8676  at  0^ ;  remains 
liquid  aX  —25*.  Is  formed,  together  with  other 
substances,  when  silver  oyanateacts  upon  isohutyl 
iodide  (Brauner,  Ber.  12,  1874).  By  the  aotion 
of  hydrochloric  acid,  fonns  tertiary  Imtylamtne 
(CH|),C-NH^  Potash  produces  symmetrical 
dit>obutyI  urea,  meltin^at  242*. 

Butyl  cyanides.    C4H,CN. 

1.  Normal  butyl  cyanide,  valeronitrile 

CH,-CH,CH,-CH,CN ; 
b.p.  140-4*  at  739-3  mm. ;  8p.gr.  0-8164  at  0* 
(Lieben  and  Rossi,  Annalen,  158,  171). 

2.  Isobutul  cyanide  (CH,),-CH-CH,-CN ; 
b.p.  126*-128^  at  714  mnu  (Erlenmeyer  and 
Hell,  Annalen,  160,  266);  129-3*-129-5*  at 
764-3  mm.  (RSohiff,  Ber.  19,567);  8p.gr.  0*8227 
at 0*, 0-8069 at  20* (Erlenmeyer and  Hell);  0*6921 
at  129*/4*  (S.).  Formed  by  the  oxidation  of 
gelatin  (Schlieper,  Annalen,  59,  15)  or  casein 
(Gunckelberger,  ibid,  64,  76)  with  chromic  acid  ; 
also  by  the  action  of  PfOg  upon  ammonium 
isovalerate  (Dumas,  Maiaguti,  and  Leblanc, 
Qrid,  64,  334).  May  be  prepared  by  heating  300 
grams  wobuty>  iodide,  98  grams  of  potassium 
cyanide,  98  grams  of  alcohol,  and  25  srams  of 
water  for  thifee  days  on  the  water-bath  (Erlen- 
meyer and  Hell). 

3.  Tertiary  butyl  cyanide  (CH,),C*CN; 
m.p.  15*-16*;  b.p.  105*-106*.  Formed  by 
mixing  100  parts  of  tertiary  butyl  iodide,  110 
parts  of  mercury  potassium  cyanide  Hff(CN)|* 
2KCN  with  75  parts  of  dry  magnesia,  and  allow- 
ing the  mixture  to  remain  for  two  or  three  days 
at  a  temperature  not  exceedinff  5*.  The  massis 
then  treated  with  water,  and  distilled  on  the 
paraffin-bath  (Butlerow,  Annalen,  170,  154). 

4.  Secondary  butyl  cyanide,  methylethyl 
aoetonitrile  C,H.-CH,-(^'CN ;  b.p.  125*;  sp.gr. 
0*8061  at  0*.  Sodium  {\  eqv.)  is  dissolved  in 
acetonitrile  in  benzene,  and  ethyl  iodide  (1  eqv.) 
added  (Hanriot  and  Bouveault,  BulL  Soa  chim. 
(3),  1,  172). 

Butyl  hydridei.    Butanes,  tetranes. 

1.  Normal  butane^  diethyl,  methylpro- 
pane  CH,*CJH,*CH,*CH, ;  b.p.  1*  (Budeiow. 
Zeitsch.  Chem.  1867,  363) ;  -OS**,  Burrell  and 
Robertson ;  sp.gr.  0*60  at  0*  (Ronalds,  Chem. 
Soc.  Trans.  1865,  54).  Ctitical  temp.  153*2; 
critical  press.  35-67  atm.  Occurs  in  crude 
petroleum  (Ronalds,  Lefebvre,  Zeitsch.  Chem. 
1 869, 1 85).  Formed  by  heating  ethyl  iodide  with 
zinc  to  150"  (Frankland,  Annalen,  71,  173; 
Schoyen,  ibid,  130,  233).  Also  by  the  action  of 
sodium  amalgam  upon  ethyl  iodide  (L5wig, 
J.  1860,  397).  A  colourless  sas,  insoluble  m 
water.  1  voL  of  alcohol  at  14*2*  and  744*8  mm. 
absorbs  18*13  vols,  of  butane  (Frankland). 

2  Isobuiane,  trimethylmeihane  (CH,),CH. 
Formed  by  heating  0*9  part  of  isohutyl  iodide 
with  2*4  parts  of  aluminium  chloride  to  120* 
(K5hnlein,  Ber.  16,  562).  Alao  by  the  action  of 
zinc  and  water  upon  tertiary  butyl  iodide 
(Butlerow,  Annalen,  144,  10).  The  gas  is 
readily  soluble  in  alcohol,  from  which  it  can  be 
expelled  by  dilution  with  water,  b.p.  — 13*4* ;  criti- 
cal temp.  133*7;  critical  press.  36-54  atm.  Vapour 
prsssurs  may  be  represented  by  the  formula  : 
log  P=i-1632*661/T4-l-75  log  T-0*0158873 

+9-06814 


714 


BUTYL. 


(Burrell  and  Robertson,  J.  Amer.  Chem.  Soo. 
1915,  37,  2482). 

G.  Cyelobutanet  tetramethylena,       I  *      i 

has  not  yet  been  obtained,  but  many  derivatiyes 
have  been  prepared  by  Perkrn  (CheuL  Soo. 
Trana.  1803,  693  ;   1894,  950). 

Butyl  Mlta.    C4HtI. 

1.  Normal  bvffyl  iodide 

CHg-CH,CH,CH,I ; 

b.p.  129*8^  (oorr.)  (Linnemann,  Annalen,  161, 
196) ;  130*4*'-131*4'*  at  745*4  mm.  (Briihl,  ibid. 
203, 21) ;  8p.gr.  1*643  at  O"",  1*6136  at  20''  (lieben 
and  Rossi,  ibid.  158,  163),  1*6166  at  2074'' 
(Briihl).  From  n-batyl  aloohol  and  hydriodic 
aoid  (linnemann,  ibid.  161, 196).  By  the  action 
of  iodine  triohloride  at  250*  it  yields  hexa- 
ohlorethane  Cs01«  (Krafift,  Ber.  10,  805). 

2.  laobutyl  iodide,  a-iodo-B-meihylpro- 
pane  (CH,),*CH*CH,I ;  b.p.  1200*  (corr.) 
(Linnemann,  Annalen,  160,  240;  192,  69); 
83''-83'25<'  at  250  mm.  (Perkin,  Chem.  Soc. 
Trans.  1884, 461) ;  119-94**  (Thorpe  and  Rodger, 
PhiL  Trans.  1894,  A,  11,  470) ;  sp.gr.  1*6401  at 
0**  (L.),  1*6066  at  2074*  (Briihl,  Annalen,  203, 21), 
1*6138  at  15715',  1*6007  at  25'/26»  (P.).  Mole- 
coiar  rotation  at  19*4''= 12*199  (P.).  From  mo- 
bntyl  alcohol,  phosphorus,  and  iodine  (Wnrtz, 
Annalen,  93,  116). 

3.  Secondary  butyl  iodide,   fi-ioddbtOane 

C,H,CHICH, ; 
b.p.  117*-]  18*  (Luynes,  Bull.  Soo.  ohim.  2,  8); 
119M20*  (Lieben,  Annalen,  150,  96);  sp-gr. 
1  -6263  at  ©•/O*,  1  -5952  at  20yO*,  1  5787  at  3070* 
(Lieben).  Formed  by  distilling  ervthritol  with 
hydriodic  acid  (Lnynes)  or  from  n-butylene  and 
hydriodic  aoid  (Wurtz,  Annalen,  152,  23).  (See 
also  Oarke,  CSiem.  Zentr.  1908,  ii.  1015.) 

4.  Tertiary  buiyliodide,  fi-methyl-fi-iodo' 
propane  ((}H,),GI ;  b.p.  98''-99*  (with  decom.) 
(BuUerow) ;  100-3*  (Pnchot,  Ann.  CSiim.  Phys. 
[5]  28,  546);  8p.gr.  1*571  at  0*,  1*479  at  53*  (P.). 
From  tertiary  butyl  aloohol  and  hydriodic  acid 
or  ftMbntylene  and  hydriodic  acid  (Butlerow, 
Annalen,  144,  5,  22) ;  is  easilv  decomposed  (by 
sQTer  oxide,  potash,  or  by  heating  with  zinc 
and  water),  into  hydriodic  acid  and  Mobutylene 
(Butlerow,  Zeitsch.  Chem.  1867,  362).  Is  also 
decomposed  by  water  in  the  cold,  yielding 
hydriodic  acid  and  tertiary  butyl  alcohoL  On 
heating  with  sodium,  yields  a  mixtnre  of  hydro- 
gen, wobutylene,  and  triMobutylene  (C|tH,4) 
(Dobbin,  Chem.  Soa  Trans.  1880,  236). 

Butyl  meraaptans  CaH^-SH. 

1.  Normal   butyl   mercaptan 

CH,*CH,CH,CH,-SH ; 
b.p.  97*-^8* ;    8p.gr.  0*858  at  0*  (Saytzeff  and 
Grabowsky,  Annaton,  171,  251 ;    175,  351). 

2.  Isobutyl   mercaptan 

(CH,),CHCH,SH  ; 
b.p.  88*;  Bp.gr.  0-848  at  ll-5*(HumaBn,  Annalen, 
96,  256),  0-83573  at  20*/4*  (Nasini,  Ber.   15, 
2882). 

3.  Secondary  butyl  mercaptan 

C,H,CH(SH)CH, ; 
b.p.  84*-85* ;  8p.gr.  0-8299  at  17*.    The  meroury 
compound  (()4llgS)|Hg  melts  at  189*  (Beymann, 
Ber.  7,  1287). 


4.  Tertiary  butyl  mercaptan 
(CH,),CSH 
is  prepared  from  tertiary  butyl  iodide,   zino 
sulphide,    and   aloohol    (Dobbin,    Ckem,    Soo. 
Trans.    1890,  641).     It  boils  at  65*-67*»  and 
solidifies  in  a  freezing  mixture. 

Butyl  nitrates. 

1.  Normal  butyl  nitrate 

CH,-CH,-CH,-CH,*0-NO, ; 
boHB  at  1S6* ;  8p.gr.  1048  at  0*  (Bertoni,  Qasz. 
ohim.  itaL  20,  374). 


i 


P. );  b.p.  123-5*-124*5*  (Perkin,  Chem.  Soo.  Tnus. 
889, 684),  8p.gr.  1-0334  at  4*/4*,  1*0264  10*/I0*, 
1*0124  25*/25*^  (P.).  From  sUver  nitrate,  urea, 
and  itobutyl  iodide  (Wurtz,  Annalen,  93,  120; 
Chapman  and  Smith,  Zeitsch.  Chem.  1869,  433). 

3.  Secondary  butyl  nitrate  boils  at  124*; 
sp.gr.  1-0382  at  0*  (Bertoni,  Qazz.  ohim.  itaL  20. 
875). 

Butyl  nitrites,  nitrobutanes  CANO^ 

L  Isobutyl  nitrite  (CH,),CH*CH,-NO, ; 
b.p.  67*;  sp.gr.  0*89446  at  0*  (Chapman  and 
Smith,  Zeitsch.  Chem.  1869, 433),  0*8878  at  4*/4*, 
0-8806  at  10*/10*,  0-8752  at  15*/16*,  0-8702  at 
20*/20*,  0-8652  at  26*/26*;  molecular  rotation  at 
8*2*b6-61  ;  molecular  refraction  »43*9  (Peridn, 
Chem.  Soc.  Trans.  1889, 686  and  757).  Pkepaied 
by  mixing  Mobutyl  alcohol  and  sulphuiio  acid,  and 
gradually  pouring  the  cooled  mixture^  into  an 
aqueous  solution  of  sodium  nitrite  (1:3);  the 
upper  layer,  oonststing  of  Mobutyl  nitrite,  is 
decanted,  washed  witii  potassium  carbonate 
solution,  and  dried.  It  is  a  pale-yellow  liquid, 
ii  apt  to  become  acid  b^  keeping,  idien 
rapid  decomposition  sets  m.  T^en  medi- 
cinally, lowers  the  Uood  pressure  and  produces 
respiratory  paralysii  (Dunstan  and  WooUey, 
Pharm.  J.  [3]  19,  487). 

2.  Tertiary  butyl  nitrite  (CH,),C*NO« ; 
b.p.  63*;  sp.gr.  0-8914  at  0*  (Bertoni,  Gazz.  ohim. 
ital.  16, 361) ;  67*-^*  (Tschemiak,  Annalen,  180, 
165).  From  the  alcohol  and  elyce^l  nitrite 
(B.);  also  from  the  iodide  and  silver  nitrite  (T.). 
A  yellow,  mobile  liquid;  soluble  in  sJcohol 
etl^r,  and  chloroform;  sparingly  solable  in 
water. 

Aromatle  nltrobutyl  d«tfati?es. 

The  butyl  derivatives  of  many  aromatic 
nitrohvdrocarbons  have  a  musk-like  odoor,  and 
aro  sold  as  *  artifioial  musk.'  Musk  Baur,  tri- 
nitro  melabutyl  toluene  C,H((3H,)(N0,),0(CH,)to 
is  formed  b^  nitrating  meta  butyl  toluene  with 
fuming  nitnc  and  f ummg  sulphuric  adds.  Butyl 
toluene  is  formed  by  Itieidel  and  Qmft's  metiiod, 
as  described  below,  by  the  action  of  tertiary 
butyl  bromide  on  toluene  in  the  presence  of  alu- 
minium chloride.  Butyl  benzene,  ethyl  benzene, 
and  xylene  aro  formed  at  the  same  time. 

An  unsymmetrioal  butyl  cresol  is  formed 
by  adding  butyl  alcohol  uid  zinc  chloride  to 
meta-eresoL  When  etherified  and  nitrated, 
possesses  the  odour  of  civet  (A.  Baur,  J.  Soa 
Chem.  Ind.  1892,  307 ;  Dingl.  poly.  J.  273,  622 ; 
J.  Soc.  Chem.  Ind.  1894,  1218). 

Butyl  xylene  may  be  prepared  by  passing  a 
curront  of  Mobutylene  gas  throuch  a  mixturo  of 
6  kilos,  m-xylene,  60  grams  ifobutyl  chloride, 
and  200  grams  aluminium  chloride  at  10*.    The 


BUTYL. 


710 


product  18  washed  with  water*  and  the  fraction 
of  the  oil  boiling  at  200*-302''  collected.  GaseouB 
hydroohlorio  and  hydrobromio  acids  may  be 
employed  to  start  the  reaction  (Act.  QeselL  flir 
Anilin-Fabriken,  Fr.  Pat.  372603). 
Butyl  etlMis  (C«H,),0. 

1.  Normal  butyl  ether;  b.p.  140-5*  at 
741*6  mm.  (Lieben  and  Rossi,  Annalen,  165, 110) ; 
Bp.gr.  0-784  at  0^  0-7685  at  20''  (L.  and  R.),  0-7865 
at  0*  (Douiner,  Annalen,  243,  8).  Bv  the  action 
of  the  sodium  derivatives  of  the  alcohol  upon 
n-butyl  bromide  (Reboul,  Gompt.  rend.  108, 39). 

2.  Isohutyl  ether  [(CH,)sOH-CHt],0 ;  b.p. 
122*-122-5<'  (Reboul.  Gompt  rend.  108,  162); 
sp.sr.  0-7616 at  15*  (R. ).  From  ifobutyl  bromide 
and  sodium  wobutylate  (R.).  The  action  of 
iiobutyl  iodide  upon  potassium  Mobutylate— 
which,  according  to  Wurtz,  yields  this  ether — 
really  gives  a  mixture  of  ditsobutylene  and  iso- 
butvl  alcohol  (Reboul). 

3.  Secondary  butyl  ether 

[C,H,-CH(CH,)],0 ; 
b.p.  120*-121*;  sp.gr.  0-756  at  21*  (Kessel,  Anna- 
len»  175,  50).  From  ethyiidene  chlorhydrin,  and 
zinc  ethyl  (K.).  Formed  in  mere  traces  only  by 
the  action  of  secondaiv  butyl  bromide  upon  the 
sodium  derivative  ot  the  secondary  alcohol 
(Reboul,  Gompt.  rend.  108,  162).  Reboul  ob- 
tained  aJso  the  foUowins  mixed  ethers  : — 

Secondary  butyl  wobutyl  ether;  b.p.  12 1*- 
122*;  sp.^.  0-7652  at  21*; 

Normal  butyl  isobutyl  ether;  b.p.  131-5*; 
sp.n.  0-763  at  15*5; 

x^ormal  butyl  secondary  butyl  ether;  b.p. 
131*;  sp.ffr.  0-7687  at  15*; 

NormiS  butyl  tertiary  butyl  ether ;  b.p.  124*; 
but  could  not  obtain  the  secondary,  tertiary,  and 
the  ditertiary  ethers  (BulL  Soc.  ohim.  [3J  2, 
25). 

Butyl  lolphidos. 

1.  Normal  butyl  sulphide 

[CH,(GH,),],S ; 
b.p.  182*;  s^sa.  0-8523  at  0*  (Saytzeff,  Annalen, 
171,  253)b  From  butyl  iodide  and  potassium 
sulphide.  Fuming  nitric  acid  yields  the  sul- 
phofto  (G«H,),SO,  (m.p.  43-5^)  (Grabowsky, 
Annalen,  175,  348).  Nitric  acid  of  sp.gr.  1-3 
converts  it  into  the  oxide  (G4H,)^0,  melting 
at  32*. 

2.  leobutyl  sulphide  [(0H,),GH-GH,1,S ; 
h,p.  172*-173*  at  747  mm.  (Grabowsky  and  Sayt- 
zeff,  Annalen,  171,  254),  170-5*  at  752  mm. 
(Beckmann,  J.  pr.  Chem.  [21  17,  445);  sp.gr. 
0-8363  at  10*  (B.). 

Isobutyldisulphide  (G4H,),S.;  b.p.  220* 
(Spring  and  Legros,  Ber.  15,  1940). 

3.  Secondary  butyl  sulphide 

(CH,-CH-G,H,),S ; 
b.p.  165*;  sp.gr.  0-8317  at  23*  (Reymann,  Ber.  7, 
1288). 

Butyl  fhioearbimldflf.  Butyl  mustard  oils; 
wothiocvanates. 

1.  Normal  butyl  thiocarbimids 

(C4H,)NGS ; 
b.n.    167*    (Hofmann,    Ber.    7,    512).    From 
f»-Dutylamine,  carbon  disulphide,  and  alcohol 
(H.). 

2.  Isobutyl  thiooarbimide 

(CH,),GHGH,NG8 ;  * 

b.p.  162*;  sp.gr.  0-9638  at  14*  (Hofmann,  Ber.  7, 
511). 


I       3.  Secondary  butyl  thiocarbimide 

C,H,-0H(GH,)NC8 ; 
b.p.  159-5*;  sp.gr.  0-944  at  12*.    Occurs  in  the 
ethereal  oil  from  spoonwort  (Coehlearia  ojfci' 
nalis)  (Hofmann,  Ber.  2, 102 ;  7,  512). 
4.  Tertiary  butyl  thiocarbimide 
(GH,),G-NCS ; 
m.p.  10-5*;  b.p.  140*  at  770-3  mm.;  sp-gr.  0*9187 
at  10*,  0-9003  at  34*  (Rudnew,  BulL  Soc.  chim. 
1880,  300).    Has  a  pleasant  aromatic  odour. 


1.  Monobutylamlnes. 

(a)  Normal  butylamine,  amincbutane 
CH,CH,CH,-GH,-NH,  j 
b.p.  75-5*  at  740  mm.  (Lieben  and  Rossi,  Annalen, 
158, 172) ;  sp.n.  0-7553  at  0*,  0-7333  at  26*  (L.  and 
R. ),  0*7^1  at  20*  (Linnemann  and  Zotta,  Annalen, 
162,  3).  Formed  by  the  action  of  potassium  hy- 
droxide upon  butyl  cyanate  (Lieben  and  Rossi) ; 
also  from  propyl  cyanide  by  zinc  and  sulphuric  acid 
(Linnemann  and  Zotta,  Annalen,  162,  3),  or  from 
nitrobutane  by  action  of  tin  and  hydrochloric 
acid  (ZUblin,  Ber.  10,  2083).  Is  misdble  with 
water;  reduces  copper,  sUver,  and  meroury 
solutions  in  presence  of  alkalis.  The  chloride 
forms  a  yellow  crystalline  compound  with  PtGl|, 
which  is  almost  insoluble  in  cold  water. 

(6)  Isobutylamine,  a-amino-fi-methylpro- 
pane  (GH,)jGHGH,-NH,  ;  b.p.  68*  (Schiff,  Ber. 
19,  565),  68^-69*  (Perkin,  Ghem.  Soa  Trans.  55, 
694);  sp.gr.  0-7357  at  55*  (Linnemann,  Annalen, 
162, 23),  0-7464  at  4*/4*,  0-7408  at  10*/10*,  0-7363 
at  15*/15*,  0*7283  at  25*/25*;  mol.  rot  at 
15-3*  5-692  ;  heat  of  combustk>n  726,990. 
F^m  Mobutyl  cyanate  and  potash  (Linne- 
mann, Annalen,  162,  23);  also  from  Mobutyl 
iodide  and  ammonia  (Hughes  and  Romer,  Ber.  7, 
511);  also  from  wobutyl  chloride  and  ammonia 
dissolved  in  water  or  iwhuM  alcohol  All  three 
tsobutylaminesare  iMroduced,thetritsobutylamine 
in  largest  quantity.  The  bases  can  then  be 
separated  by  means  of  ethyl  oxalate.  The 
product  is  firet  separated  into  two  fractions,  the 
one  rich  in  the  monoisobutylamine,  .the  other 
rich  in  the  di-  and  tri-  compounds.  To  the 
former  water  and  then  ethyl  oxalate  are  added ; 
the  primary  base  is  thus  converted  into  the 
oxamide  G,0,(NHG4H,)„  which  is  almost 
insoluble  in  boiL'ng  water,  the  secondary 
amine  being  changed  into  the  ethyl  oxamato 
G,H40*G,0,N(G4H,),.  The  other  fraction 
(anhydrous)  being  poured  intQ  ethyl  oxalate,  the 
primary  and  secondary  bases  aro  converted  into 
oxamates.  The  tertiary  base  is  distilled  o£^  and 
the  oxamates  are  saponified  by  heating  with 
sliJced  lime.  The  calcium  oxamates  can  be 
separated  by  crystallisation,  the  diuobutyloxa- 
mate  being  the  more  soluble  in  alcohol,  from 
which  it  separates  in  slender  silky  needles 
(Halbot,  Gompt  rend.  104,  228). 

Gan  be  produced  by  heatins  wobutvl  alcohol 
with  ammoniacal  zinc  chloride  to  260*  (Merz 
and  Gasiorowski,  Ber.  17,  624),  or  by  the  action 
of  caustic  potash  (10  p.o.  solution)  upon  a  mix- 
ture of  bromine  and  wovaleramide  (equal  mole- 
cules) at  60*  (Hofmann,  Ber.  15,  769). 

HOxed  with  water,  contraction  and  deyek>p- 
ment  of  heat  are  produced.  A  mixture  of  equal 
volumes  of  water  and  isobutylamine  has  a  sp.gr. 
of  0*9002  at  15*/15*,  instead  of  the  oak.  density 


716 


BUTYL. 


0-8681  (Perkm,  Chem.  Soo.  Tnoa.  1880»  606). 
With  abtolnte  alcohol  and  tbe  amme  nmilar 
results  wwD  obtainedl,  the  8p.gr.  of  a  mixture 
of  equal  volumeB  betng  0-791  at  16*/lff*,  instead 
of  0*7662,  the  calculated  number, 
(e)  Secondary  buiylamine 

C,H,-CH(NH,)-CH,  f 

b.p.  6S*;  sp.gr.  0-718  at  23*  (Mensohutkin,  CShem. 
Zentr.  1808,  L  702).  Formed  by  the  action  of 
potash  upon  seocmdary  butyl  emanate,  or  of  am- 
monia upon  seoondary  butyl  iodide  (Hofmann, 
Ber.  7,  613).  Also  by  the  action  of  dflute  sul- 
|ihurio  aoid  upon  secondary  butyl  mustard  oil 
(Heymann,  Ber.  7,  1280). 

By  the  reduction  of  methyl  ethyl  ketozime 
by  hydrogen  and  finely  dliTided  nickel  at 
160^-170*,  seoondary  butylamine  and  di- 
fiecondary  butylamine  are  produced.  They  axe 
liquids,  the  latter  boiling  at  132V768  mm.  and 
forming  an  oxalate  melting  at  104*  (Mailhe, 
Compt.  rend.  1906,  113). 

Beoondaxy  butylamine  has  been  separated 
into  its  optical  antipodes  by  Thom6  (Ber.  1903, 
682) ;  [a]^  7-42*  at  20*. 

(tf)  Tertiary  butylamine  (CH|),CNHs; 
b.p.  46-2*  at  760  mm.  (Rudnew,  C&m.  Soc. 
Abstr.  1879,  40,  141);  43-8*  at  760  mm. ;  sp.  gr. 
0-7137  at  3^  0-7064  at  8*,  0-6031  at  16*  (EL), 
Formed  in  small  quantity  by  the  action  of 
potash  upon  Mobutyl  cyanate  (linnemann, 
Annakn,  162,  19;  Hofmann,  Ber.  7, 613).  Also 
as  a  by-product  in  preparing  trimethyl  acetic 
acid  from  trimethyl  carbinol  iodide  and  mercuric 
cyanide  (Rudnew). 
.  2.  DIbatylaiiilnai. 
(a)  Di-normal  butylamine 

(C3H,-CH,-CH,-CH,),NH  j 

b.p.  160*.  Formed  in  small  quantities  by  the 
action  of  potash  up6n  butyl  cyanate  (Lieben  and 
Rossi,  Aimalen,  168,  176) ;  aliso  by  the  action  of 
butyl  chloride  on  ammonia  (Betrg,  Ann.  Chim. 
Phys.  [71 3, 294).  Gives  [(04H,),NH-HCl],Pta4; 
yellow  needles,  almost  insoluble  in  cold 
water. 

{b)  Di-iso-butylamine 

[(CH,),CHCH  J,NH ; 

b.p.  136*-137*»;  sp.gr.  0-7677  at  4*/4*,  0-7491  at 
I&'/IS*,  0-7426  at  25*/26*  (Perkin,  Cham.  Soc. 
Trans.  1889,  697).  From  Mobutyl  bromide  and 
alcoholic  ammonia  at  160*  (Ladenburg,  Ber.  12, 
949) ;  also  from  Mobutyl  alcohol  and  ammoniacal 
zinc  chloride  at  270^  (Mers  and  Gasiorowski,  Ber. 
17,  627).  The  hydrochloride  (G«H,),NH-Ha 
forms  plates  or  leaflets  easily  soluble  in  alcohol 
and  water,  slightlv  in  ether.  The  platinum  com- 
pound forms  dark-red  prisms,  soluble  in  water, 
alcohol,  and  ether  (Blalbot,  Gompt.  rend.  104, 
366).  The  nitroso-  deriyative  (Cf4H,),N*N0  is 
a  disagreeably  smelling  oil;  m.p.  0*;  b.p. 
213*-216*  (with  decomposition) ;  obtained  by  the 
action  of  potassium  nitrite  upon  the  hydro- 
chloride (Ladenburg,  Ber.  12,  949). 
(c)  Di'tertiary  butylamine 

[(CH,),CI,NH; 

produced  as  iodide  when  tertiary  butyl  iodide 
and  tertiary  butylamine  are  heated  to  60^;  at 
70^  the  nuxture  is  decomposed,  forming  iso- 
butylene  and  tertiary  butylammonium  iodide 
(Rudnew).     The  iodide  is  easily  soluble  in  watei 


or  alcoh<d;  on  heating  the  aqueous  solution 
eyolves  tertiary  butylamineu 

3.  TrflmtylaiiiliMi. 

(a)  Tri-normal  butylam%ne{Cfi,^JSi\h,^ 
211*-216*  at  740  nun. ;  sp.gr.  0-791  at  0*,  0*7782 
at  20*,  0-7677  at  40*.  From  butyl  eyanate  and 
potash,  toother  with  the  mono-  and  dl-  com- 
pounds (Lieben  and  Rossi,  Annalen,  166,  116). 
With  butyl  iodide  forma  iodide  d  tetcmbatyl- 
smmoninm  N(G«H,)«I«  which  crystallises  in 
small  plates  (L.  Mid  R.).  Also  by  the  action  of 
ammonia  on  butykhloride ;  b.p.  216-6*  (Beig. 
Ann.  Ghim.  Phys.  [71  3,  299). 

(h)  Tri'i»o4>utylamine  (G«H,)«N ;  b.p. 
177*-180*  (Reimer,  Ber.  3,  767);  184*-18r 
(Sachtleben,Ber.ll,733).  Sp.^.0-786at21*(a). 
From  diisobutylainine  and  ifobntji'  bromide 
(R.)  From  the  alcohol  and  unmoniacal  zinc 
chloride  at  270''  (Merz  and  Gasiorowski,  Ber.  17, 
627);  also  from  tfobutyl  iodide  and  aqneoos 
ammonia  at  160"  (Malbot^  Gompt.  vend.  106,674). 
Is  not  miscible  with  water.  Forms  salts  with  hy- 
drochloric, nitric,  and  sulphuric  adds,  iHiich  are 
extremely  soluble  and  crystallise  with  difficulty. 
The  platinum  double  salt  forms  Isrge  ruby-red 

oiystab  (Malbot^  ^>°£.^-  ^^'^  ^^»  366). 

BatytenM  CJEi^  Three  iromcrie  bntyknes 
aro  possible  and  all  are  known. 

1.  Normal  (aYbutylene.  Eth^  ethylene 
GHg-GH,-GH:GBL;  b.p.— 6*. 

FormaUon, — ^From  normal  butyl  iodide  and 
alcoholic  potash  (Saytaef^  J.  pr.  Ghem.  [21  3, 
88;  Grabowsky  and  Saytsefi^  Annalen,  179, 
330).  From  bromethylene  and  une^thyl 
(WurtK,  Annalen,  162,  21),  together  with  bu^ 
alcohoL  From  normal  butylamine  and  nitroiia 
acid  (V.  Meyer,  Ber.  10, 136).  Propared  by  digeet- 
inff  on  the  water-bath  100  grams  normal  batyl 
iodide,  200  grains  potash,  and  160  gimms 
alcohol  (90  p.c. )  (8.).  A  gas  at  ordinary  tempera- 
tures, whicb  combines  readily  with  hydnodic 
acid  to  form  secondacy  butyl  iodide;  and  with 
bypochlorous  add  to  form  chloromethylethyl 
carbinol  GHt-CHi-GH(OH)-GH.CL  Ptased  oyer 
copper  heated  to  redness  lonns  butadiene 
GHt :  GH-GH  :  CHa,  which  may  be  polymerised 
to  rubber  by  means  of  metallic  sodium  (Eng.'Pkit 

9722,  1911). 

2.  fi-Buiylene.    Symmeirieai  dimetkyleikyi' 

ene  GH,-C^ :  GH-GH, ;  b.p.  1*  at  741-4  mm. 
(Lieben,  Annalen,  160, 108);  sp^^.  0-636  at  —13-6 
(Puchot,  BulL  Soc  chim.  30,  188). 

Formed  by  the  action  of  potaah  upon 
secondary  butyl  iodide  (Lnynes,  Annalen,  129, 
200;  Lieben,  ibid.  160,  108).  Together 
with  tsobutyleiie  by  dropping  iso-  or  normal 
butyl  alcohd  upon  strongly  heated  zinc  chloride 
(Neyole,  BuD.  Soc.  chim.  24,  122 ;  Le  Bel  and 
Greene,  Amer.  Ghem.  J.  2,  23).  From  trithio- 
aldehyde  (GAS)t  and  copper  (Eltekow,  Ber. 
10,  1904).  By  heating  a  mixture  of  methyl 
iodide  and  allyl  iodide  with  sodium  (Wnrtx, 
Annalen,  144,  236). 

Preparation. — ^/«obutyl  abohol  is  allowed  to 
drop  upon  heated  zinc  chloride,  and  the  eyolyed 
gas  is  kd  into  sulphuric  add  diluted  with  hall 
its  yolume  of  water ;  tlus  retains  the  t  sobutyleneu 
The  unabsorbed  gas  is  led  into  bromine,  and  is 
again  liberated  by  action  of  sodium  (Le  Bel  and 
GreoMB,  BulL  Soc.  chim.  29,  306).  Two  stereo- 
isomeric  modifications  are  known  (Widioenna 
Ghem.  Zentr.  1897,  ii  267). 


BUTYL. 


717 


/B-Butylene  combines  with  bromine  to  form  a 
dibromidf)  boiling  at  ISO'^-ISS*'.  This  oomponnd, 
by  the  action  of  potash^  forms  mono-bromo- 
pseudo-butylene CUaGBr:CHCH,;  b.p. 87''-88* 
(Hdlz,  Annalen.  250, 230).  Chlorine  forms  a  di- 
chloride ;  b.p.  112^-114'' (Ghechookow,  BulL  Soo. 
ohim.  43,  127). 

3.  yBuiylene.  /tfobntylene,  unsymmetrical 
dimethyl  ethylene  (CH,),C:GH,;  b.p.  -6'' 
(Bntlerow,  Zeitsoh.  Ohem.  1870, 236).  liquefied 
by  a  pressure  of  2-2|  atmospheres  at  16®- 18^  Is 
produced  by  the  dry  distillation  of  fats  (Faraday, 
PhiL  Trans.  1825,  440) ;  by  heating  the  vapour 
of  fusel  oil  to  redness  (Wurts,  Annalen,  104, 
249),  together  with  ethylene  and  ethane ;  also 
from  U^t  petroleum,  ^ligroin'  (b.p.  60^-90^) 
(Prunier,  J.  1873,  347) ;  from  mo-  or  tertiary- 
butyl  ioidide  and  alcoholic  potash  (Butlerow, 
Annalen,  144, 19) ;  by  heating  trimethyl  oarbinol 
and  dilute  sulphuric  acid  (1  toL  HJ3O4  to  2  toIs. 
water)  (Butlerow) ;  from  isobutyl  aloohiol  and 
sine  chloride,  though  in  very  small  quantity 
(NeTol^  BulL  800.  ohim.  24,  122). 

Pnparaiion, — (1)  5  parts  of  Mobutyl  alcohol, 
5  parts  sulphuric  acid,  1  part  of  water  and  sand 
are  heated  together  (Lermontow,  Annalen,  196, 
117).  (2)  Puchot*s  method  (Ann.  Chim.  Phys. 
[5]  28,  508)  of  heating  Mobutyl  alcohol  with  a 
mixture  of  sulphuric  acid,  potassium  sulphate, 
and  ffypsum,  gives  a  mizture  of  pseudo-  and  iso' 
but3rlene.  (3)  A  mixture  of  2  parts  of  oaustio 
potash  and  3  parts  of  alcohol  (90  p.o.)  is  slowly 
added  to  2  parts  of  ifobutyl  iodide,  and 
gently  warmed  (Butlerow,  Zeitsch.  f.  chem.  1870, 
238).  Butylene  is  a  gas,  with  unpleasant  smell, 
^lif^htly  soluble  in  water;  combines  with  hydriodio 
acid  to  form  tertiary  butyl  iodide.  A  mixture 
of  three  parts  of  sulphuno  acid  and  1  part  of 
water  completely  absorbs  the  gas;  on  distilling 
the  diluted  solution  trimethyl  carbinol  is 
evolved.  It  formi  a  mercury  compound 
C4H,(HgN0,)(Hg|N0,)  (Denig^  Oompt.  rend. 
126,  1043).  Oxidising  agent»-^.cr.  potassium 
permanganate— form  carbon  dioxide,  formic  and 
acetic  acids,  and  oxalic  acid  (and  in  the  case  of 
chromium  trioxide,  acetone)  (Zeidler,  Annalen. 
197, 251).  Bv  the  action  of  a  mixture  of  5  parts 
sulphuric  acid  and  1  part  of  water  forms  dode- 
cylene  (triMobutylene)  G,aH|4;  b.p.  177-5*- 
178-5*;  sp.gr.  0-774  at  0**  (Butlerow,  Ber.  6, 
561). 

Batyleiie  aleohol  v.  Bviifiene  fiyeoU. 

Ba^leiM  dibromidas. 

1.  Normal  hutyltne  dihromide,  afi- 
dihromhutant  GH,GH,-GHBrGHtBr ;  b.p. 
165-6'*-166'' ;  sp.gr.  1-876  at  0*  (Wurtz,  Annalen, 
152,  23),  1-8503  at  0\  1*8204  at  2070<*  (Gra- 
bowsky  and  Saytzeff,  Annalen,  179, 332).  Formed 
from  a- butylene  and  bromine  (Wurta);  from 
normal  buty  bromide  and  bromine  at  160* 
(Linnemaniu  Annalen  1^61,  199).  Gives  a- 
butylene  by  action  of  sodium. 

2.  fi'ButylenB  dihromide,  fiy-dihrom- 
butane  GHj-GHBrGHBrGH,;  b.p.  168*;  sp.gr. 
1  -82 1  at  0*.  Formed  from  /S-  butylene  and  bromine 
(Wurts,  Annalen,  144,  236),  or  by  heating  a-  o? 
3-brombutane  with  iron  and  bromine  (V.  Meyer 
and  MuUer.  J.  pr.  Chem,  [2]  46,  180).  Decom- 
posed bv  heating  to  14(r  with  water  and 
lead  oxide,  forming  lead  bromide  and  methyl 
ethyl  ketone  (Eltekow,  Ghem.  Soc.  Abstr.  1879, 
34). 


3.  Jso^utylene  di-bromide,  afi-dibrom- 
B-methyl  propane  {CR^fiBrGEfir;  b.p.  148'*- 
149*  at  737  mm. ;  8p.gr  1*798  at  14*  (Linne- 
mann,  Annalen,  162,  36),  b.p.  149*6*  (corr.) 
(Thorpe),  sp.gr.  1  7434  15*/15*  (Perkin).  From 
Mo-butylene  and  bromine  (Ij.  ;  also  Wurtz, 
Annalen,  104,  249 ;  Hell  and  Rothbeig,  Ber.  22, 
1737).  Bv  heating  with  water  to  150*  mo- 
butyraldehyde  and  Mobutylene  glycol  are  formed. 

4.  Tetramethylenedibromide,  aS-^t- 
brombutane,  GHtBr*GHa*GHa*CHaBr ;  boils  at 
188*-190*  (Gustavson  and  Demjanoff,  J.  pr. 
Ghem.  [2]  39, 543).  {See  also  Hainscourt,  (yompt. 
rend.  132,  345.) 

5.  PP-Dibrombutane  CH,*CBr,*CH,*CH, ; 
boils  at  144*-145*  (Wislicenus  and  Holz,  Anna- 
len,  250, 28^). 

6.  ay-Dibrombulane 

CH,BrCH,*CH,Br*CH, ; 
boils  at   174*-175*  (Perkin»  Ghem.  Soc.  Trans. 
1894,  963). 

Bntylene  eyanlds. 

Isobutylene  dicyanide  (dimeihyl  sued' 
nonttriU)  GN*G(GH,),*GH.*GN ;  b.p.  218*-220*. 
By  treating  an  aqueous  alcoholic  solution  of 
potassium  cyanide  with  y-butylene  bromide,  and 
allowing  the  mixture  to  stand  for  a  fortnight. 
A  colourless  oil,  moderatelv  soluble  in  water. 
Heated  to  150*  with  strong  hydrochloric  acid,  it 
is  decomposed  into  ammonia  and  dimethylsuo- 
cinic  acid  (Hell  and  Rothberg,  Ber.  22,  1737). 

Batyleno  glyeolehlorbydriii,  /S-chloroisobiityl- 
aleohol  (GH,).*Ga-GH.OH ;  b.p.  137.  From 
Mobutyleoe  and  hypochlorous  acid  (Butlerow^ 
Annalen,  144,  25).  Soluble  in  lar^  excess  of 
water.  See  also  Michael  and  Leighton  (Ber. 
1906,  2157). 

/S-Ghlorotsobutyl  alcohol  is  also  formed  by  the 
union  of  hvdrogen  chloride  with  isobutylene 
oxide,  whicn  rMults  from  the  action  of  dry 
powdered  potassium  hydroxide  on  chloro- 
titeethyl  oarbinoL  The  last  may  be  prepared 
from  magnesium  methyl  bromide,  chloroacetone 
and  ethyl  chloroacetate.  /3-chlorowobutyl 
alcohol  boilB  at  132*-133*.  It  forms  a  nitrate 
by  the  action  of  concentrated  sulphuric  and 
nitric  acids  G(Me),aGH,NOa,  and  a  nitrite 
G(Me)aa*GH,NO|  with  nitrous  aokl,  which 
distixiffuiBhes  it  from  the  isomeric  chlorotri- 
meth^  carbinol  (L.  Henry,  Gompt.  rend.  1906, 
142,  493). 

BatylApe  diamines. 

1.  T etramethylenediamine  (putrescine), 
a5-diaminobutane  NH2-GHa*GHa*GHa*GH,-NH«, 
occurs  in  urine  and  faces  in  oases  of  cystmuria, 
and  ^so  arises  during  the  putrefaction  of  her- 
rings. It  IB  prepa^ea  by  reducing  an  alcoholic 
solution  of  dicyanoethylene  with  sodium  (Laden- 
burg,  Ber.  1886,  780;  T^ellmann  and  Winthaer, 
Anmden,  228, 229) ;  or  in  a  similar  manner  from 
Buccinaldehyde  dioxime  (Giamician  and  Zanetti, 
Ber.  1889,  22,  1968,  1970).  Odourless  crystals 
meltingat27*-28*(G.Z.)andboaingat  158M60*. 
SmeDs  like  piperidine.  It  is  stronglv  basao, 
readily  absoroe  G0|,  and  forms  a  well-defined 
dihydrochloride,  aunchloride,  and  platinichloride. 
The  piorolonate  is  of  some  physiological  import- 
ance (Otori,  Ghem.  Soa  Abstr.  1905,  iL  126). 

Willst&tter  and  Heubner  have  prepared  the 
tetramethyl  derivative  of  tetramethylene  dia- 
mine, and  the  biquatemaxy  hexamethylammo- 
nium  salt  corresponding  to  it  (Ber.  1907,  3871, 


718 


BUTYL. 


8874).  Tha  identity  of  oS-diaminobutaae  | 
with  pntntoine  xests  on  the  experiments  of 
UdraiiBzky  and  Baunuuin  (Ber.  1888,  2938). 
Brie^  (UheoL  Zentr.  1907,  L  1703)  oonsiden 
the  identity  not  proven,  as  also  do  Willstatter 
and  Henbner  (Lc). 

2.  DitnethyUthyUnediamine^  fiy-dia- 
tnincbiUaM  OH,-CHNH,CHNH,-CH„  has  been 
prepared  by  Angeli  (Ber.  1890,  1358). 

/«o-Batylaeetl«  add  v.  Gafboic  acid. 

Batyl  ehlond  v.  Chloral. 

Batyl-laetlnle  aeld  v.  Htbboztbutybic  acids. 

Ba^lene  glyeob. 

1.  Normal-iay-butylene  glycol,  afi-di- 
hydroxybutane  CH,*0H,-CH0HCH20H ;  b.p. 
19iM92*  at  7471  mm. ;  sp.gr.  1-0189  atOVO^, 
1-0069  at  17-5/0^  From  normal  butylene  di- 
bromide  (Saytzeff  and  Grabowsky,  Annalen,  179, 
332). 

2.  fi-Butylene  glycol,  oydihydrox^ndant 
CHg-CaH(OH)-CH,-CH,OH;  b.p.203-6*-204*(Ke. 
kui^,  Annalen,  162,  310) ;  8p.gr.  1-0259  ( Wurts, 
J.  1873,  474 ;  BolL  Soa  chim.  41,  362).  Pro- 
dnoed  in  small  quantity  by  the  redaction  of  dilute 
aqueous  solution  of  aldehyde  by  sodium-amalgam 
(K.).  Prepared  from  /9-ozybutyric  aldehyde  by 
reduction  with  sodium  amalgam  (W.). 

3.  Isobutylene  glycol,  afi'dihydroxy-tL' 
mdhylpropane  {CH.t)fi{OK)<mtOB;  b.p.  176*- 
178* ;  sp.gr.  1-0129  at  0*,  1003  at  20*.  Pto- 
dnoed  by  tiie  fermentation  of  siurar  in  presence 
of  tartaric  acid  (Hennineer  and  &nson,  Oompt. 
rend.  106, 208).  Formed  by  heating  Mobutylene 
bromide  with  potassium  carbonate  and  water 
(Nevole,  BulL  Soa  chim.  27,  63) ;  also  b^  oxida- 
tion of  Mobntylene  by  means  of  potassram  per- 
manganate in  neutral  aqueous  solution  (Wagner, 
Ber.  21,  1232). 

4.  Symmetrical  dimeihylethylene  gly* 
col,  fiyJihydroxybtUane  GH,-GHOH-aHOH-GH,; 
b.p.  183*-184*.  Formed  by  heating  for  6  or  7 
hours  1  ToL  of  symmetrical  dimethylethylftie 
oxide  G^Efi  with  3  vols,  of  water  to  100* 
(Eltekow,  Chem.  Soo.  Abstr.  1883,  566). 

5.  Tetramethylene  glycol,  aJU-dihydroxy^ 
butane OH(CH,)«-OH ;  boUs at 203*>205* ;  sp.gr. 
1-0111  (Dekkers,  Chem.  Soc.  Abstr.,  1891, 164). 

6.  A'butylene  glycol,  differing  from  the 
above,  boiling  at  183*-184*;  has  alM>  been  pre- 
pared  by  Wurtz  (Ann.  Chim.  Phys.  [3]  55,  452); 
sp.gr.  1-048  at  0*. 

7.  a-Methyl  propanediol 

OHCH,-OH(CH,)-CH,OH 

(Henry,  BulL  Soc  chim.  [3]  13,  1002  .  Cesart», 
Chem.  Zentr.  1897,  li  179). 

ButyltOt  diiodide,  tepdiioddbtUane 
CH,CHI-CH,CH  ,1 ; 

sp.gr.  2-29L  From  /3-butyleue  glycol  and 
hy£iodic  acid  (Wurtz,  Bull.  Soc.  chim.  41,  362). 

bobutylan*  dlnlMta  C.H,(NOt)r  Bt  treat- 
ment of  isobutylene  with  concentrated  nitric 
acid  (Haitinger,  Monatsh.  2,  287).  Forms  a 
crystslline  mass.  Plrobably  the  same  body  was 
obtained  by  Beilstein  and  Kurbatow  (Ber.  14, 
1621)  by  treating  the  petroleum  of  Tiflis  (b.p. 
40*-n60*)  with  nitric  acid  (sp.gr.  1-62).  It  formed 
needles  which  melted  at  96*.  They  were  insoluble 
in  water,  but  soluble  in  alcohol  and  ether. 

Batytone  oxidai  C4H,0.  q 

1.  r9obutylene  oxide    (CH,),d- — "bH^; 


b.p.  51*-52*;  sp.gr. 0*831 1  atO*.  From  thechkr- 
hydrin  CfifiLO^  and  potash  (Eltekow,  Ghmn. 
Soo.  Abstr.  1883,  566). 

2.  s-Dimethyleihyltnt  oxide 


CHj-OT-CH 


•CH,; 


b.p.  l^-bVi  8p.gr.  0*8344  at  Hf,  Formed  from 
the  chlorhv<h3n  (prepared  from  the  symmetrical 
dimethyethylene  and  hypoohloroas  acid)  and 
potash  (Eltekow,  Chem.  Soa  Abstr.  1883,  666). 

BUTYRALDEHYDE.  By^yricdtdekyd^CJEifi. 
This  compound  exists  in  two  isomeric  fonns^ 
termed  normal  and  tsobutyric  aldehyde  respec- 
tively. 

Mwmal  bntynktohydt  CH,(CH,),-CHO  is 
formed  together  with  aoetaldehyde  and  propal- 
dehyde  by  the  action  of  ohzomio  acid  upon 
fibrin,  casein,  and  albumen  (Guckdberffer, 
Annalun,  64, 39).  It -is  readily  prepared  by  dis- 
tilling a  nuxture  of  calcium  formate  (2  molsL)  and 
oalohim  butyrate  (1  moi.)  m  quantities  of  60 
erams  at  a  time  with  twice  the  weight  of  iron 
filings.  The  distillate  is  fractionated,  the 
fraction  70*-110*  treated  with  sodium  hydrogen 
sulphite  (bisulphite),  then  shaken  with  ether  to 
extract  impurities,  and  finally  dirtilled  wiUi 
excess  of  soida  (Lipp,  Annalen,  211,  355 ;  Linne- 
mann,  '  ibid.  161,  186 ;  Kahn,  Ber.  1886, 
3364).  Bodronx  has  appUed  Gricnaid's  reagent 
to  a  solution  of  orthoiormio  and  aoetaldehyde, 
thA^by  obtaining  a  75  p.c.  yield  of  butyralde- 
hyde  (Chem.  Zentr.  1904,  L  1077). 

Properties, — ^Normal  butynddehyde  is  a 
liquid  which  boils  at  73*-74*  (Lipp,  at  73*-77*) 
and  has  a  sp.gr.  0-8170  at  20^/4^  (Brahl,  An- 
nalen, 203, 18).  It  is  soluble  in  27  parts  of  water. 
With  sodium  hydrogen  sulphite  (bisulphite)  it 
unites,  yielding  a  crystalline  compound  (Justin, 
Ber.  1884»  25()5).  When  tseated  with  aqueous 
ammonia  at  0*,  it  yields  butyraldehyde-am* 
monia  C4K|^NO,3iH,0,  which  crystallises  in 
acute  rhomoic  tetrahedia  and  melts  at  30i*-31* 
(Guckelberaer).  If,  however,  alcohoUo  ammonia 
and  the  aldehyde  are  allowed  to  stand  for  a 
month,  and  then  heated  for  a  day  at  100*,  con- 
densation occurs,  and,  after  removal  of  ammonia, 
alcohol  and  unattached  butyialdehydc  by  dis- 
tillation, two  bases,  tetrabutyraldine  and  di- 
butyraldine  CgHifNO  can  be  separated  by 
fractional  precipitation  with  nlatinic  ohlorida. 
The  latter  only  can  be  orystsJlised,  and  when 
heated  is  converted  into  paraoonine  C.H|gN  and 
water  (Schiff,  Annalen,  157,  352).  The  triehk>- 
robutvraldehyde  (butylchlocal)  and  its  hydrate 
have  been  prepared  by  Pinner  (Annalen,  179, 26). 

/sobntynldehyda  (CH,),CH-CHO  can  be  pre- 
pared by  the  oxidation  of  Mobutyl  alcohol  with 
potassium  dichromate  and  sulphuric  acid  (Lipp, 
Aimalen,  205,  2 ;  Pinner,  Ber.  5,  699 ;  Foasek, 
Monatsh.  2, 614 ;  4,.  661),  or  by  distillii^  calcium 
formate  with  calcium  Mobutyrate  (linnemann 
and  Zotta,  Annalen,  162,  7).  It  dissolves  in  9 
parts  of  water  at  20*,  and  is  soluble  in  alcohol 
and  ether.  The  boiling-point  is  63*~64*  at 
757  mm.  (Brfihl,  Annalen,  203,  18),  and  the 
sp.gr.  0-7938  at  20^/4<'  (Bruhl),  0^9722  at  15* 
(Perkin,  Chem.  Soa  Trans.  1884,  476).  Con- 
densation compounds  have  been  obtained  by 
Perkin  (Chem.  Soo.  Trans.  1883,^1). 

BUTYRIC    ACID    C^H.O,.    Two    isomeric 


BUTYRIC  ACID. 


719 


forms  of  this  acid  are  known,  normal  butyric 
and  isohutyno  add. 

Normal  butyrie aeid CH.CH ,CH,COOH 
Occurrence, — ^In  ordinaiy  butter  in  combina- 
tion with  glycerol  to  the  extent  of  2  p.c. ;  also 
in  the  i^uits  of  Heradeum  viUosum  (Fiach)  and  of 
Pencedavum  sativum  (Benth.  CL  Hook,  /.)  m 
hexyl'  butyrate  and  octyl  butyrate  respectively ; 
in  the  oil  of  Eucalypiua  Perriniana  as  n-butyl 
butyrate  (Smith,  J.  Koy.  Soc.  New  South  WalM, 
1914,  48,  464).  Butyric  acid  is  also  found  in 
flesh  juice,  and  is  frequently  a  constituent  of 
decomposing  orgaiiic  matter  (i;.  art.  Fismxkta- 
HOH)  (J.  1857,  363,  402,  403,  569 ;  1858,  231 ; 
1859,  363,  364 ;  1861,  454 ;  1866,  311).  The 
occurrence  of  butyric  acid  in  sour  milk  is  treated 
of  by  Thorpe  (Ghdm.  Zentr.  1909,  ii  1774). 

Preparatum, — (1)  Butyric  acid  is  a  frequent 
product  of  the  oxidaticm  of  organic  substances  ; 
casein,  fibrin,  and  albumen,  for  example,  yield 
this  add  among  other  products  on  oxidation 
with  manganese  dioxide  and  sulphuric  add 
(Guckelbeiger,  Annalen,  64,  68). 

(2)  All  amylaceous  and  saccharine  sub- 
stances which  yield  lactio  acid  as  a  product  of 
their  fermentation  can  undergo  a  further  fer- 
mentation to  butyric  acid,  and  this  fact  is  made 
use  of  for  the  preparation  of  the  acid.  5  kilos, 
of  rice  or  potato  starch  are  boiled  with  60  litres 
of  water  for  some  hours,  aUowed  to  cool,  and  the 
product  after  24  hours  is  treated  with  60  grams 
of  malt  stirred  up  with  2  litres  of  milk,  with  1 
kilo,  of  findv  divided  flesh,  and  with  2  kilos,  of 
chaUc,  the  chalk  being  added  to  neutralise  the 
lactic  and  butyric  adds  as  rapidly  as  they  are 
formed,  and  the  whole  is  allowed  to  remain  with 
occasional  stirrins  for  several  weeks  at  a  tempe- 
rature of  25*-30*.  When  the  evolution  of  gas 
has  ceased,  the  product  is  heated  to  80*,  filtered, 
precipitated  witn  sodium  carbonate  to  decompose 
the  calcium  salt,  again  filtered,  evaporated  to  a 
small  bulk,  and  treated  with  sulphuric  add. 
The  oily  layer  of  acid  so  obtained  islractionated 
to  free  it  from  the  acetic  and  caproic  adds 
formed  simultaneously,  and  the  fraction  155*- 
174*  is  extracted  with  water,  which  dissolves 
the  butyric  add  but  leaves  the  caproic  add  un- 
dissolved ;  the  aqueous  extract  is  then  neutral- 
ised with  lime,  the  solution  concentrated,  and 
the  salt  finally  decomposed  by  hydrochloric  add 
(Grillone,  Annalen,  165,  127). 

(3)  In  the  presence  of  a  schizomyces — ^the 
so-cisJled  BadUus  mbHUs,  which  can  readily  be 
obtained  by  stirring  hay  in  water,  straining  the 
liquor  through  a  sieve,  and  boiling  for  5  minutes 
—Fitz  (Ber.  11, 52)  has  found  that  storch  readily 
undergoes  fermentation,  yielding  normal  butyno 
add  as  chief  produoL 

Butyric  acid  has  also  been  obtained  by  the 
fermentation  of  glycerol  in  3  p.o.  aqueous 
solution  with  a  spedes  of  schizomyces  (Fitz, 
Ber.  9, 1348 ;  10, 276),  and  has  been  prepared  by 
various  synthetical  methods  (fVankland  and 
Duppa,  Annalen,  138,  218;  Geuther  and 
FrUioh,  ibid.  202,  306).  (For  oonditions 
affecting  the  production  of  butyric  add  by 
fermentation,  see  FsBianiTATEOir.) 

Proptfiies. — Butyric  acid  is  a  oolouriess, 
transparent  liquid,  having  an  odour  resembling 
that  of  rancid  butter,  ana  a  sour  burning  taste. 
Cooled  to  -19''  it  solidifies,  and  the  crystals 
melt  at  about  -2*.    The  acid  boils  at  161*5''  at 


760  mm.  (Kahlbaum,  Ber.  16,  2480) ;  at  162*3* 
(oorr.)  (Unnemann,  Annalen,  160,  228 ;  Zander, 
ibid.  224,  64);  162-02  (oorr.)  (Thorpe  and 
er) ;  and  has  a  sp.gr.  0*96704  at  15*/15* 
(Perkin,  Chem.  Soc.  Trans.  1884,  483),  0*9590  at 
20*/4* ;  fiijy,  1-39906  (Scheig,R.  1899, 169).  Butyric 
add  is  inflammable  and  bums  with  a  blue  flame. 
Alcohol,  wood-spirit,  and  water  dissolve  it  in  all 
proportions,  and  from  the  aqueous  solution  it 
can  be  separated  by  addition  of  caldum  chlorida 
Prolonged  boiling  with  nitric  add  converts  it 
into  succinic  add.  By  the  action  of  caldum 
carbide,  dipropyl  ketone  may  be  obtained 
(Haehn,  Chem.  Zentr.  1906,  iL  17). 

SaUa. — The  metallic  salts  of  normal  butyric 
add  are  generally  soluble  in  water,  and  are  crys- 
talline.   NaB  and  KB  orystidline  in  indistinct 

cauliflower^like  groups.  AgB  crystallises  in 
needles  or  monocUnic  prisms,  and  dissolves  in 
200  parts  of  water  at  14*  (Linnemann  and 
Zotta,  Annalen,  161,  177) ;  100  parts  of  water 
dissolve  0-413  part  at  16*  (Griinzweig,  Annalen, 
162,  203).  J^B^5HaO  ciystaUises  in  very 
soluble  scales  (Pdouze  and  G^lis,  Annalen,  47 
249).  BaBa,4H,0  crystallises  in  nacreous 
scales,  and  dissolves  in  2*48  parts  of  water  at  14* 
(Linnemann  and  Zotta).  OaBt,H,0  crystal- 
lises in  rhombic  forms;  100 parts  of  water  dissolve 
19-4  parts  at  0*.  (For  solubility  toble,  «ee 
Hecht^  Annalen,  213,  72.)  SiB,  forms  monodinio 
prisms ;  100  parts  of  water  at  20*  dissolve  39*2 
parU  of  the  salt  (Griinzweig).  ZnB<,2H,0 
forms  monodinic  prisms ;  100  |Murts  of  water  at 
16*  dissolve  10-7  P^rts  of  the  crystallised  salt 
(Griinzweig).  PbB,  is  an  oil  which  slowly 
solidifies   (Markownikow,    Annalen,    138,   361). 

CHiBt»HaO  orystalliaes  in  triclinic  forms  (Alth« 
Annalen,  91,  176),  and  CuB,,2H,0  crystallises 
in  monoolinio  forms  (Pelouze  and  G^lis). 

Separaiicn  fmm  nrmiet  aeHie^  and  propionic 
acids. — Mach  and  Portele  (Chem.  Soc.  Abetr. 
1890,  1344)  nve  the  following  method  for  the 
estimation  of  butyric  acid  in  the  presence  of 
acetic  add  (as  in  wine):  500  cc  of  the  solution 
is  distilled  to  a  bulk  of  125  0.0.,  diluted  to  the 
original  volume,  and  again  distilled  till  only 
125  CO.  remains.  This  is  done  four  times.  The 
total  add  in  the  distillate  is  estimated  bv 
titration  with  soda  or  baryta.  If  soda  is  used, 
the  neutralised  distillate  is  evaporated  down, 
sulphuric  acid  is  added,  and  the  mixture  steam- 
distilled.  The  distillate  is  neutralised  with 
baryta  and  evaporated  so  far  that  it  will  solidify 
when  cold.  The  barium  butyrate  is  then  ex- 
tracted with  absolute  alcohol,  and  the  aqueous 
solutions  of  the  separated  salts  treated  with 
sulphuric  add  and  steam-distilled,  the  add  in 
the  distillate  being  subsequently  titrated. 

The  separation  of  formic,  acetic,  propionic 
and  butyric  adds  is  also  dealt  with  by 
Willcox  (Chem.  Soc.  Proc  1895,  202);  Luck 
(Zeitsch.  AnaL  Chem.  10,  185);  Haberland 
{ibid.  1899,  217);  and  Muspratt  (J.  Soc. 
Chem.  Ind.  1900,  204).  An  expression  con- 
necting the  nercentage  of  butjrric  acid  in  an 
aqueous  distillate  with  the  proportion  of  the 
distillate  to  the  original  solution  is  given  by 
Leonard,  Smith,  and  Richmond  (Analyst,  1897, 
92). 

Bntyryl  chloride,  obtained  by  treating  96 


720 


BUTYRIC  ACID. 


grams  of  butyric  acid  with  100  grams  of  phos- 
phorus trichloride  (Burclcer,  Ann.  Chlm.  Phys. 
[5]  26,  468);  boils  at  lOOMOl-5*  (Linnemann); 
and  has  a  8p.0.  1'0277  at  23*74*  (Brtthl). 

Butyrie  anhydride,  prepared  bv  the  action  of 
butyiyl  chloride  on  butyric  aoia  (Unnemann, 
Annalen,  161, 179),  or  by  the  action  of  1  molecule 
of  acetic  anhydride  or  2  mols.  sodium  butyrate 
(Michael,  Chem.  Zentr.  1901,  L  1088),  boils  at 
191*-193*  (L.);  and  has  a  sp.gr.  0-978  at  12-6* 
(Gerhardt,  Annalen,  87,  156). 

Bntyrunide,  formed  by  heating  dry  ammo- 
nium bniyrate  for  six  hours  at  230*  (Hofmann, 
Ber.  1882,  982) ;  crystallises  in  tables ;  melts  at 
116*;  bolU  at  216*  (J.  1866,  616);  and  is  readUy 
soluble  in  Tv«ter. 

a-Chlorobntyrie  add  CH,-GH,-OHCl-OOaH 
is  a  thick  liquid  difficultly  soluble  in  water 
(llarkowuikow,  Annalen,  163,  241). 

iB-Chlorobatyrie  aeid  CH,GHC1-0H,-C0,H, 
thick  liquid  (Pinner,  Ber.  1879,  2066;  1884, 
2008). 

7-Chlorobatyrie  add  GHaCl-CH,-CH,-GOtH. 
Esters  only  biown  (Henry,  Chem.  Zentr.  1898, 
ii*  273)b 

ai8-I>iehIorolratyrie  add 
CH,-CHa-CHCl-CO,H,  melts  at  72*-73*  (Melj 
kow,  Annalen,  234,  201 ;  266,  372). 

/Sr-Dlehlorobutyrie  aeid 

CH,Cl-CHa-CH.-(X),H;  melts  at  49*-60*  (L^ 
pieau,  Compt.  rend.  129,  226). 
oo/s-Trienlorobirtyrle  add 

CH,-C!Ha-Ca,-CO,H;  melts  at  60*  (Kahlbaom 
Ber.  1879,  2337  ;  Garffaiolli,  Annalen,  182,  186). 

M7-Triehk)robatym  add 
CH,a-CH,-CCl,-CO,H ;  melts  at  73*-76*  (Nat- 
terer,  Monatsh.  4,  661 ;  6,  266). 

ajSjB-Triehlorobutyrie  aeid 
CHs-ca,-CHaCO|H;  melts  at  62*  (Szenio  and 
Ta^KeeeU,  Ber.  1896,  2666). 

^etraeUorolnityrie  add  C^^Jdfi^ ;  melts  at 
140*  (Pelooie  and  Gf^lis,  Arch.  Pharm.  [3]  10, 
434). 

Bromobiityrie  adds  have  also  been  obtained 
by  Naumann  (Annalen,  119,  120),  Schneider 
(J.  1861,  468),  and  Michael  and  Nbrton  (Amcr. 
Chem.  J.  2,  16).  {8§e  also  doves,  Chem.  Zentr. 
1902, 1.  406.) 

/sobutyrie  add  (CH,),-CH<X)OH. 

Occurrence. — ^/jobutyrio  acid  occurs  in  the 
fruit  of  Siliqua  dvicis  (GrOnzweig,  Chem.  Soo. 
Trans.  1873,  373),  and  in  amioa  root  {Arnica 
nuniiana)  (Sijgel,  Annalen,  170,  348). 

Preparation. — ^/M>butyric  acid  is  most  readily 
prepared  by  the  oxidation  of  isobutyl  alcohol 
with  a  mixture  of  sulphuric  acid  and  potassium 
diohromate.  Pierre  and  Puchot  (Ann.  Chim. 
Phys.  [4]  28,  366)  give  the  following  propor- 
tions :  isobutyl  alcohol  (300  parts)  is  mixed  with 
water  (1600  parts)  and  sulphuric  add  (640  parts) 
and  into  the  well-cooled  mixture  finely  powdered 
potassium  dichromate  (400  parts)  is  gradually 
mtroduced.  An  ethereal  layer  separates,  con- 
sisting of  isobutyl  Mobutyrate,  which  is  de- 
composed by  allowing  66  parts  to  fall  slowly  on 
100  parts  of  caustic  potash  to  which  one-tenth 
its  weight  of  water  has  been  added ;  the  re- 
sulting potassium  salt  ii  then  distilled  with 
dilute  sulphuric  acid,  and  the  aqueous  acid 
purified  by  fraotional  distillation. 

Synthetical  methods  for  preparing  this  acid 
have  been  described  by  Franklaud  and  Duppa 


(Annalen,  138,  337),  and  Markownikow  (Anna- 
len, 138,  361). 

Properties. — /«obutyric    acid    reeembles   its 
isomeride  in  appearance,  but  has  a  less  disagree- 
able odour.    It  boils  at  152*  at  760  mm.  (Kahl- 
baum,  Ber,  16,  2480) ;  at  163*6*~163-8*  at  760-3 
mm.  (Briihl,  Annalen,  200, 180) ;  at  164*-164-2* 
(Zander,  ibid.  224,  77) ;    J64-0*  (oorr.)  (Thorpe 
and  Rodger);    ffp.gr.  0-9661  at  0*  (Zander); 
0-9603  at  20*  (Linnemann,  Annalen,  162,  9). 
It  dissolves  in  five  times  its  volume  of  water  {L.\. 
The  metallic  salts  of  Mobutyric  aoid  are  more 
soluble  in  water  than  those  of  the  normal  acid. 
The  potassium  and  sodium  salts  fbrm  cauli- 
flower-like masses.    AgB  oiystalUses    in    cha- 
racteristic tabular  forms;   100  parts  of  water 
dissolve  0*928  part  at  16*  (GrQnzweig,  Annal^, 
162,      210).       MigF,     forms      white     scales. 
CaBs,6HaO  forms  four-sided  monoclinio  ciys- 
tals ;  100  parts  of  water  at  18*  dissolve  36  parts 
of  crystallised  salt  (G.),  and  the  solubility  in- 
creases as  the  temperature  rises.    Sr5,,6HaO; 
100  parts  of  water  at  17*  dissolve  44-1  parts 
of     the     crystallised     salt    (G.).    BaB^iHgO 
I  forms  monoclinic  ciystals  (Fitz,  Ber.  1880, 1316). 
Zn^„H,0 ;  100  parts  of  water  at  19-6*  disK^ve 
17*3  parts  of  the  crystallised  salt  (GrOnzweig). 

PbB,  crystallises  in  rhombic  tables  and  dissolves 
m  11  parts  of  water  at  16*. 

/sobatyryl  ehloride,  prepared  by  tnating 
Mobutvrio  aoid  (12  parts)  with  phosphoms  tri- 
chloride (7  parts),  and  subsequently  Hiafciliing 
(Tonniee  and  Staub,  Ber.  1884,  860);  boils  at 
91-6*-92-6*  at  748-2  mm.;  and  has  a  sp-gr. 
1  -01 74  at  a0*/4*  (Brtlhl,  Annalen,  203,  20). 

/sobntyryl  anhydride,  obtained  by  boiling 
Mobutyric  acid  with  isobutyryl  chloride  for 
12  hours  in  a  reflux  apparatus  and  fraotion- 
ating  the  {voduot  (Tonnies  and  Staub,  Ber. 
1884,  860);  boils  at  181-6*  at 734  mm.;  and  has 
a  sp.gr.  0-9674  at  16-6*. 

/tfobatynumide,  formed  by  heatmg  dry  am- 
monium isobutyrate  at  230*  for  six  hours ;  mdts 
at  12S*-129*  (Hofmann,  Ber.  1882,  982). 

a  Chloroisobntyrie  uM  (CH,),CCa-COtH ; 
melts  at  31*  and  boils  at  118*  (Henry,  BulL  Soo. 
chim.  26,  24;  Balbiano,  Ber.  1878,  1693). 

a3-DleliloroMobiityrie  aeU 
CH,CH(CH.a)-Ca-CO.H  (Broohet^  Ann.  Chim. 
Phya.  [7]  10,  376). 

Triemorisobntyrie  aeid  C«Hsa,0, ;  melts  at 
60*  (Gottlieb,  J.  pr.  Chem.  [2]  12,  1). 

BromoMobatyrle  aetdf  have  been  prepared  by 
Markownikow  (Annalen,  163,  229);  E^gelhom 
{ibid.  200,  66,  08);  Cahours  {ibid.  Suppit  2, 
34P,  362). 

Butyrie  eaten.  These  compounds  are  for 
the  most  part  prepared  by  the  action  of  bntyrio 
acid  on  the  corresponding  alcohols  in  presence 
of  some  dehydrating  agent  snoh  as  solphnrio 
aoid,  the  temperatiue  oeinf  raised  eventually 
to  comfdete  the  reaction.  Butyric  esters  are 
liquids  wliioh  dissolve  in  alcohol  and  ^her  in 
all  proportions,  but  are  only  very  sparingly 
soluble  in  water.  On  saponification  with 
caustic  potash  fhey  yield  the  corresponding 
alcohol  and  potassium  batyrate. 

Methyl  butyrate  C4HfO,Me,  prepared  ami- 
larly  to  the  ethj^  ester,  is  a  oolourleBS  liquid 
with  a  pleasant  odour  resemblinff  that  of  pine- 
apples.   It  boils  at  102*3*  at  760  mm.  (^n- 


CABBAGE 


721 


rnann,  Pogg.  Ann.  [2]  12,  41 1;  and  has  a  ep.gr. 
0-9194  at  074*  (ElsasBOr,  Annalen^  218,  314). 

BCbyl  batynte,  huiyrie  ether,  is  i^pajred  by 
adding  1  part  by  wei^t  of  solphono  add  to  2 
parte  eaoh  by  weight  m  butyric  acid  and  alooboL 
The  liquid  becomee  heated,  and  the  mixture  at 
once  eeparates  into  two  layers  of  which  the 
apper  one  consists  of  ethyl  ontyrate.    To  com- 

Siete  the  reaction  it  is  necessary  to  heat  the  pro- 
net  at  about  80*  for  a  short  time.  The  upper 
layer  is  separated,  washed  with  water,  cuned 
over  calcium  chloride,  and  distilled.  The  pre- 
sence of  considerable  quantities  of  water  does 
not  seem  to  hinder  esierifioaiion  (Pelouze  and 
G^s,  Annalen,  47,  250). 

Ethyl  butyrate  is  a  colourless  liquid  having 
an  odour  like  that  of  pine-apples.  It  boils  at 
119-9''  at  760  mm.  (Schumann);  and  has  a 
8p.gr.  0-8996  at  074**  (Elsftsser),  b.p.  120-0''- 
m-S**;  sp.gr.  0-8784  2074^  (Matthews  and 
Paville,  J.  Phys.  Chem.  1918,  22, 1).  A  solution 
of  ethyl  butyrate  is  used  in  perfumery  and  in 
confectionery  under  the  name  of  pine-apple  oiL 

Propyl  butyrate  boils  at  142*7*'  at  760  mm. 
(Schumann);  and  has  a  sp.gr.  0*8930  at  0*/^* 
(Els&sser). 

/«opropyl  butyrate  boils  at  129*  at  766  mm. ; 
and  has  a  sp.gr.  0-8787  at  0**  (Silva,  Ber.  1869, 
283),  0-9027  at  0*  (Pribram  and  Handl, 
Monatsh.  2,  690). 

Butyl  butyrate  boils  at  164*8*  (coir.),  and 
has  a  sp.gr.  0*8760  at  12*  (Linnemann,  Ann- 
alen, 161,  196 ;  compare  also  Lieben  and  Rossi, 
ibid.  168,  170). 

/Mbutyl  butyrate  boils  at  166*9*  at  760  mm. 
(Schumann);  and  has  a  sp.gr.  0-8798  at  0*, 
0-8664  at  16*  (Grtlnzweig,  Annalen,  162,  207). 

/«oamyl  butyrate  boUis  at  178*6*  at  760  mm. 
f Schumann);  and  has  a  sp.gr.  0*8823  at  0*/4* 
(SIs&sser). 

The  hexyl-  and  ootyl-butyrates  occur  in  the 
oili  from  the  fruits  of  Heradeum  gigarUeum 
(Franohimont  aad  Zincke,  Ber.  4,  824)  and 
PasUnaca  aativa  (Renesse,  Annalen,  166,  80) 
respectively. 

fSthereal  salts  of  Mobutyric  acid  have  been 
prepared: 


Metbyl  isobutyrate  boils  at  92-3*'  at  760  m.m. 
(Schumann):  and  has  a  sp.gr.  0*9112  (Els&sser). 

Bthyl  isobutyrata  boils  at  llOl*  at  760  mm. 
(Schumann) ;  its  sp.gr.  is  0*8903  (Elsfisser). 

Propyl  Mobutyrate  boils  at  133*9*  at  760  mm. 
(Schumann;  its  sp.gr.  is  0-8843  (Els&sser). 

/«opropyl  isobutyrate  boils  at  118*-121*  at 
727  mm.;  and  has  a  sp.gr.  0*8787  at  0*  (Piibram 
and  Handl). 

/tfobutyl  iffobutyrate  boils  at  146*6*  at 
760  mm.  (Schumann);  its  sp.gr.  at  0*  0*8762 
(Qrllnzweiff). 

JManiyi  iM»butyrat6  boils  at  168-8*  at 
760  mm.  (Schumann) ;  and  has  a  sp.gr.  0*8759 
at  074*'  (Elsasser). 

A-BUTYROBETAINE  v,  Bbtahtbs. 

BUTYROLACTONE  v.  Hydboxtbutybio 
A01D8. 

BUTYRONE.  Diprvpyl  ketone  GvHiaO. 

Butyrone  is  obtained  by  distilling  calcium 
butyrate,  or  preferably  a  mixture  of  calcium 
butyrate  and  calcium  carbonate  (Schmidt,  Ber.  ^ 
5,  697) ;  the  crude  product  is  dehydrated  by* 
treatment  with  calcium  chloride,  and  purified  by 
fractional  distillation.  Butyrone  bous  at  144  , 
and  has  sp.gr.  0*8196  at  20*,  does  not  com- 
bine with  ammonia  or  sodium  hydrogen  sul- 
phite (bisulphite),  yields  a  mixture  of  propionic 
and  butvnc  acids  on  oxidation  with  chromic 
acid,  and  is  converted  into  a  secondary  alcohol 
G7H11O  and  butyrone-pinacone  C|4Hs«0|  on 
treatment  with  sodium  amalgam  and  water 
(KurtK,  Annalen,  161,  206). 

An  isomeride  di-isopropylketone  can  be  pre- 
pared by  distilling  calcium  Mobutyrate  (Miinoh, 
Annalen,  180,  327) ;  it  boils  at  124<'-126%  has  a 
8p.er.  0*8264  at  17°,  and  does  not  combine 
with  sodium  hydrogen  sulphite. 

BUTYRO-REFRAGTOHETER  v.  Bbtbacto- 

HBTXBS. 

BUXIN.  An  alkaloid  obtained  from  the  box- 
tiee  ( Buxus  sempa^rens).  Hager  (Chem.  Zentr. 
1877,  119)  found  it  in  beer  as  an  adulterant.  It 
is  said  by  Walz  (N.  J.  P.  14,  16)  to  be  identical 
with  belieerine  (q.v.).  * 

BYNIN.  Trade  name  for  liquid  malt  ex- 
tract. 


0 


CABBAGE^  Braaeiea  (deracea.  This  plant 
has  been  modified  by  careful  selection  and 
cultivation  so  as  to  produce  several  apparently 
very  different  varieties : 

1.  Those  which  form  a  compact  head  by 
overlapping  of  the  leaves,  as  in  the  ordinary 
cabbage. 

2.  Those  of  a  straggling,  open  habit  of 
growth,  with  a  branching  stem  but  no  distinct 

*  heart '  or  head,  e,g,  thousand-headed  kale. 

3.  Those  in  which  a  dense  head  of  imperfect 
flowers  are  formed,  as  cauliflower  and  broccoli. 

4.  Those  in  which  the  stem  is  enormously 
developed  so  as  to  form  a  globe,  as  in  kohl- 
rabi 

6.  Those  in  which  a  large  number  of  small 

*  heads  '  are  formed  on  a  tall  stem — Brussels 
sprouts. 

Of    the    cabbage    itself,    there    are    many 
varieties,  differing  in  size,  shape,  and  colour. 
Like    all    the    members   of    the    Cruci/ercs, 
Vol.  L— 5r. 


cabbages  contain  sulphur  compounds,  some  of 
which  easily  undeigo  decomposition  with  pro- 
duction of  sulphuretted  hydrc^en. 

The  average  composition  of  cabbages,  as  used 
for  cattle  food,  is,  according  to  Kellner — 

Sol.  carbo- 
Water    Protein       Pat       hydrates     Fibre        Ash 
84-7  2-6  0*7  81  2*4  16 

whilst,  accordmg  to  American  analyses,  the 
edible  portion  of  culinary  cabbages  conteuns  : 

Sol.  carbohydrates  Fibre 

Water     Protein     Fat — — — Ash 

90-3         2-1         0-4  5-8  1'4 

Included  in  the  carbohydrates  mannitol  and 
glucose  have  both  been  detected  (Busolt,  J. 
Laudw.  1914,62,117). 

Cabbages,  as  a  farm  crop,  respond  to  liberal 
manuring,  and  in  inland  districts  are  benefited 
by  a  smaU  dressing  of  the  soil  with  common  salt. 
They  do  best,  as  a  rule,  on  heavy  land,  and  are 
usuaUy  transplanted  from  seed-beds. 

3  ▲ 


722 


CABBAGE. 


Formentated  cabbage  (sauerkraut)  yields 
acetic  and  propionic  acids  with  occasional  traces 
of  formic  acid  together  with  an  inactive  form  of 
lactic  acid.  Ethyl  and  propyl  alcohols  are  also 
formed  together  with  small  quantities  of  esters 
(Nelson  and  Beck,  J.  Amer.  Cnem.  Soc.  1918, 40, 
1001).  

CACAO  BUTTER  (spelt  also  Cocoa  Butter), 
is  expressed  from  the  cacao  bean,  the  seeds  of 
the  cacao  tree,  Thechroma  cacao  (Linn.)* 

The  cacao  tree  is  indigenous  to  the  West 
Indies,  but  has  been  intx^uced  into  various 
tropical  countries,  especially  Central  and  South 
America  and  to  the  West  Coast  of  Africa  and  the 
islands  in  the  Bay  of  Benin.  It  has  also  been 
introduced  into  Nigeria,  and  an  inducement  has 
been  held  out  by  the  Government  to  the  Nigerian 
peasants  to  grow  cacao.  As  the  beans  are 
chiefly  worked  up  for  the  preparation  of  cacao, 
the  cacao  butter  must  be  considered,  to  some 
extent,  a  by-product  of  the  chocolate  industry. 
For  the  production  of  cacao  butter,  the  beans 
are  roasted  over  a  coke  fire,  and  the  husks  aie 
separated  by  winnowing.  The  kernels  thus  laid 
bare  are  ground  under  millstones  and  reduced  to 
a  paste^  when  the  bulk  of  the  fat  is  removed 
by  hot  expression  in  hydraulic  presses.  As  the 
fat  in  the  bean  has  undeigone  slight  hydrolysis, 
it  is  usual  to  add  a  carbonate,  either  of  potassium 
or  ammonium,  to  the  beans  before  roasting, 
Hence,  in  the  examination  of  cacao  butter,  the 
presence  of  ammonia  or  potash  soap  may  be 
expected. 

In  Cook*s  patent  process  (U.S.  Pat.  1000013, 
1911)  the  roasted  beans  are  decorticated,  and 
then  pressed  sufficiently  to  powder  the  mass,  and 
express  part  of  the  fat. 

A  special  form  of  press  for  separating  the  fat 
from  the  beans  has  been  devised  by  Hanel 
(Ei^z.  Pat.  13188, 1015). 

The  average  composition  of  the  cacao  bean 
is,  according  to  Konig,  as  follows  : — 

Per  cent. 

Pat 490 

Water    .      *  .                           .6^ 
Proteins          ....     12*8 
Carbohydrates          .                   .25*7 
Crude  fibre      ....       .3-71 
Ash 3-41 

The  composition  of  the  shell  is  as  follows  : — 

Fat 4-21 


Water    . 
Proteins 
Carbohydrates 
Crude  fibre 
Ash 


1119 
13-61 
43-95 
17-63 
9-88 


100-47 


The  proportion  of  fat  in  the  bean  varies  from 
about  60  to  56  p.c.  In  the  production  of  cacao 
powder,  only  a  portion  of  the  cacao  butter  is 
expressed,  whereas  the  beans  intended  for  the 
manufacture  of  best  chocolate  are  not  expressed, 
so  that  the  full  amount  of  fat  is  allowed  to  remain 
in  the  ground  mass.  Manufacturers  of  cheap 
chocolates  remove  a  portion  of  the  costly  cacao 
butter  by  expression,  replacing  it  by  cheaper 
substitutes  {stp  Choooultb  fats).  The  kernels 
contain  a  small  amount  of  theobromine,  a  portion 
of  which  passes  into  the  cacao  butter  on  ex- 
pression. 


Cacao  butter  has  a  yellowish-white  colour, 
turning  white  on  keeping;  an  agreeable  taste  and 
pleasant  odour,  recalling  that  of  chocolate.  At 
the  ordinary  temperature,  the  fat  is  somewhat 
brittle.  It  appears  to  consist,  to  a  very  laige 
extent,  of  oleodistearin  and  d.eodipalmitin.  The 
solid  acids  of  cacao  butter  consist  of  stearic  and 
palmitic  acids ;  small  quantities  of  arachidic  acid 
are  stated  to  occur  also  amongst  the  solid  fatty 
acids. 

The  proportion  of  stearic  acid  in  the  fat  is  as 
high  as  39-40  p.c.  Amongst  the  liquid  fatty 
acids  there  seem  to  be  present  about  6  p.c  of 
acids  less  saturated  than  oleic  acid,  most  likely 
linolic  acid.  From  the  iodine  value  of  the  cacao 
butter,  viz.  32-42,  the  conclusion  may  therefore 
be  drawn  that  it  contains  not  more  than  about 
30  p.c.  of  oleic  add.  The  unsaponifiable  matter 
of  cacao  butter  amounts  to  less  than  1  p.c. 
Matthes  and  Rohdioh  (Ber.  1908,  41,  19) 
found  in  the  unsaponifiable  matter  a  hydro- 
carbon (most  likely  identical  with  amyruene), 
stigraasterol,  and  a  phytosterol  melUng  at 
130°. 

In  the  older  literature  the  statement  fre- 
quently occurs  that  cacao  butter  does  not  turn 
rancid.  But  it  is  a  matter  of  common  experi- 
ence that  cacao  butter,  exposed  to  light  ana  air 
at  the  ordinary  temperature,  becomes  rancid  in 
the  course  of  time.  Equally  erToneous  is  the 
statement  that  rancid  cacao  butter  is  obtained 
from  mouldy  beans.  Most  shipments  of  cacao 
beans  become  mouldy  in  transit,  but  as  the 
beans  in  the  initial  state  of  manufacture  are 
roasted,  the  mould  is  destroyed,  so  that  cacao 
butter  prepared  from  these  beans  need  not,  of 
necessity,  readily  become  rancid.  With  the 
growth  of  the  consumption  of  chocolate  and 
cacao,  the  trade  in  cacao  beans  has  become  of 
very  great  importance. 

Holland  is  the  largest  exporter  of  cacao 
butter,  whilst  Germany  was  the  largest  producer, 
but  exports  relatively  very  little.  Of  late 
years  the  demand  for  the  fat  has  greatly 
mcreased,  and  the  price  has  risen  corre- 
spondingly. 

Cacao  butter,  being  very  high  in  price,  in 
normal  times  even  higher  than  oows*  butter,  is 
frequently  adulterate  with,  if  not  completely 
substituted  by,  *  chocolate  fats.'  The  adulterants 
formerly  employed,  such  as  tallow  and  paraffin 
wax,  are  easily  detected,  and  hence  tlieee 
adulterants  have  disappeared.  The  same  holds 
good  of  coco-nut  and  palm-nut  stearins,  which,  for 
some  time,  were  largely  used  to  adulterate  cacao 
butter.  Latterly,  adulteration  with  cacao-shell 
butter  has  been  practised  and  is  still  in  vogue ; 
for  this  purpose,  the  husks  are  ground  and  again 
expressed,  or  even  extracted  with  volatile  sol- 
vents. As  the  fat  thus  obtained  yields,  in 
analysis,  practically  the  same  characteristiG 
numbers  as  genuine  cacao  butter  itself,  chemical 
analysis  alone  is  unable  to  reveal  adulteration 
with  cacao-shell  butter. 

Products  commeroiaUy  known  as  'green 
butter '  are  now  extensively  used  for  mixing 
with  cacao  butter.  They  consist  of  a  refined 
vegetable  tallow  coloured  with  chlorophyll  or 
with  an  aniline  dye.  The  adulteration  may  be 
detected  by  a  modification  of  Halphen's  test 
(J.  Pharm.  Chim.  1908,  28,  346).  On  adding 
bromine  to  a  solution  of  the  fat  iD  carbon  tetra- 


CADMIUM. 


723 


ohioride,  pure  oaoao  batter  immediately  gives  a 
turbidity,  whilst  in  the  ease  of '  gnen  buttw  *  the 
liquid  remains  clear  (Revis  and^olton.  Analyst, 
1913,  38,  201). 

Cacao  butter,  being  chiefly  produced  as  a 
bv-produot  in  the  manufacture  of  cocoa,  is 
obtainable  in  laige  quantities :  it  is  at  present 
mainlv  used  in  the  manufacture  of  cheaper 
chocolate.  Smaller  quantities  are  used  in 
confectionery,  in  pharmacy  for  iwA-lring  supposi- 
tories and  nitroglycerin  tablets,  and  in  the 
*enfleurage*  process  of  preparing  delicate 
ethereal  oils.  J.  L. 

CACHALOT  OIL.  Oil  obtained  from  the 
blubber  of  the  cachalot.  (For  its  properties  and 
composition,  v.  Fendler,  Chem.  Zeit.  1905,  29, 
565.) 

CACODTUAGOL.  Syn.  for  guaicol  caco- 
dylate. 

CACODTUC  ACID  and  CACODYLATES  v. 
Absxnio,  QBOAmo  compounds  of. 

CADAVERINE  r.  Putbefaction  basis. 

CADE,  OIL  OF  V,  Junipbb. 

CADIE  GUM  V,  Gums. 

CADINENE  V.  TsBFimis,  Juiopni. 

CADMIUM,  {Kadmium,  Get.)  Sym.  Cd. 
At.  wt  112-3  (Quinn  and  Hulett);  112*42 
(Baxter  and  Hartmann) ;  112*32  (De  Ckminck 
and  Gterd). 

Cadmium  occurs  in  small  quantities  as  sul- 
phide in  Oreenockite  at  Bishopton,  Renfrew- 
shire, and  in  Pennsylvania  and  Bohemia.  This 
is  the  only  ore  containing  cadmium  as  the  prin- 
cipal element.  Cadmium  occurs  in  small  quan- 
tities in  nearly  all  zinc  ores,  but  the  percentage 
is  considerably  lower  than  that  usually  stat^. 
Jensch  and  Klieeisen  have  shown  that  the  cad- 
mium in  zinc  ores  averages  about  0*1  p.c.,  0*5  p.c. 
being  only  reached  in  the  richest  samples,  though 
occasional  specimens  are  stated  to  have  yielded 
considerably  higher  values.  It  occurs  also  in 
the  silicate  and  carbonate  of  zinc  at  Freiberg, 
Derbyshire,  and  Cumberland,  and  in  most  com- 
mercial zinc. 

PrepanUum. — ^In  the  reduction  of  zinc  ores, 
the  first  }>ortions  of  the  distillate  consist  of  a 
mizture  of  the  metals  zinc  and  cadmium  and 
their  oxides,  but  containing  a  higher  percentage 
of  cadmium  (on  account  of  its  greater  volatility) 
than  the  original  ore,  and  by  further  similar 
treatment  it  is  still  further  increased.  When 
sufficiently  rich,  it  is  used  for  the  extraction  of 
the  cadmium.  At  Silesia,  the  first  portion  of  the 
distillate,  which  contains  from  2  to  6  p.c.  of 
cadmium,  is  mixed  with  about  one-fourth  of  its 
weight  of  coal,  and  distilled  at  a  dull-red  heat ; 
the  cadmium  then  distils  with  a  little  zinc,  but 
the  greater  i>art  of  the  latter  metal  remains 
behind.  The  cadmium  is  purified  by  fractional 
distillation  imtU  a  product  of  99*5  p.c.  or  more  is 
obtained;  it  is  then  cast  into  small  cylinders 
about  i  inch  thick. 

The  chief  output  of  cadmium  comes  from 
SUesia.  A  little  cadmium  is  recovered  in  this 
country  in  the  purification  of  zinc  sulphate,  in 
the  manufacture  of  lithopone,  or  from  baghouse 
dusts  as  lead  smelters.  Another  source  which 
may  become  important  in  view  of  the  increasing 
number  of  electrolytic  zinc  plants  is  the  precipi- 
tate obtained  in  purifjring  the  electrolyte  prior 
to  deposition  of  the  zmc,  as  well  as  the  anode 


mud.  Flue  dust  from  brass  works  contains  as 
much  as  2-3  p.c.  of  cadmium.  The  supply  can 
easily  bo  increased  to  meet  any  reasonable 
demand. 

Various  wet  methods  for  the  extraction  of 
the  cadmium  from  the  concentrated  flue  dust 
have  been  proposed  and  tried.  Some  of  these 
are  dependent  on  the  precipitation  of-  cadmium 
from  acid  solutions  by  means  of  zinc ;  others  on 
the  solubility  of  zinc  in  neutral  ammonium 
carbonate. 

Electrolytic  methods  for  the  refining  of 
cadmium  are  employed,  the  cadmium  being 
deposited  on  platinum  electrodes  and  distilled 
in  vacuo. 

Properties, — Cadmium  is  a  white  metal  with 
a  tinge  of  blue,  of  strong  lustre,  and  capable  of 
taking  a  high  polish.  It  produces  a  metallic 
streak  on  paper  like  lead,  but  less  leadily. 
Cadmium  is  compact  in  texture  and  of  fibrous 
fracture,  harder  and  more  tenacious  than  tin; 
it  may  be  drawn  into  thin  wire  or  hammered 
into  leaves,  but  when  heated  to  80^  it  becomes 
brittle,  and  may  be  powdered  in  a  mortar.  On 
account  of  its  crystalline  structure,  it  crackles, 
like  tin,  when  bent. 

By  distillation  in  a  current  of  hydrogen,  cad- 
mium may  be  produced  in  regular  octahedra  and 
other  forms  of  the  cubic  system. 

Cadmium  melts  at  321*7''  (Holbom  and  Day) ; 
320*9''  (Holbom  and  Henning),  and  boils  at 
765 *9''  under  a  pressure  of  760  mm.  (Heycock  and 
Lamplough).  Its  vapour  density  at  1040^  is 
3*94  referred  to  air,  or  56*3  referred  to  hydrogen. 
Hence  it  appears  that  the  molecule  of  cadmium 
contains  but  one  atom  at  that  temperature, 
whilst  further  the  values  for  the  latent  heat 
of  vaporisation    (calculated   from  the  vapour 

Eressure)  indicate  similar  molecular  states  in 
quid  and  gas  (Traube).  It  is  obtained  in 
colloidal  solution  by  electric  sparking  with  a 
cadmium  cathode  in  water. 

According  to  Demarcay,  it  emits  vapours 
when  heated  below  the  melting-point  (Compt. 
rend.  95,  183).  When  heated  in  air,  it  bums 
readily,  evolving  brown  fumes  of  the  oxide. 
Cadmium  dissolves  in  hydrochloric  and  sul- 
phuric acids  with  evolution  of  hydrogen.  It  is 
readilv  attacked  by  nitric  acid.  It  combines 
directly  with  chlorine,  bromine,  and  iodine  when 
placed  in  solutions  of  those  elements.  Cad- 
mium gives  a  brilliant  spectrum  of  red,  green, 
and  blue  lines,  and  its  use  has  been  suggested 
as  a  convenient  standard  in  refractometry 
(Lowry). 

The  salts  of  cadmium,  as  a  rule,  are  but 
slightly  dissociated  in  solution — ^this  is  especially 
so  in  the  case  of  the  iodide — and  are  hence 
liable  to  be  incompletely  precipitated  by 
reagents. 

Detection. — ^AU  compounds  of  cadmiumi 
when  heated  on  charcoal  in  the  reducing 
flame,  give  a  brown  incrustation.  Sulphuretted 
hydrogen  produces  a  yellow  precipitate  in  acid 
solutions,  soluble  in  strong  hydrochloric  acid, 
insoluble  in  alkaline  sulphides;  it  is  thus  dis- 
tinguished from  antimony  and  arsenic. 

Estimation, — Cadmium  may  be  precipitated 
as  carbonate  and  weighed  as  oxide.  Owing, 
however,  to  the  reduction  of  the  oxide  and  the 
great  volatility  of  the  metal,  if  filter  papers  are 
employed,  the  results  are  low,  even  when  careful 


724 


CADMIUM. 


precautions  are  taken.  A  Goooh  oraoible  and 
asbestos  filter  should  therefore  be  employed. 
Oadmium  may  also  be  estimated  by  precipitation 
from  a  neutral  solution  by  excess  of  oiammonium 
phosphate,  and,  after  standing  some  time, 
collecting  the  precipitate  on  a  weighed  filter 
paper,  dried  at  105^  (Page  and  Miller). 

Mectrolytio  methods  of  estimation  have  also 
been  found  to  be  suitable  and  to  yield  aocurate 
results.  A  cyanide  solution  with  an  E.M.F.  of 
3  to  3-5  volts  and  a  current  of  0-02  to  0-06 
ampere,  is  a  convenient  arrangement  (Rim- 
bacn). 

To  separate  it  from  other  metals  not  preoipit- 
able  bjr  sulphuretted  hvdroeen  in  acid  solution,  it 
is  precipitated  as  sulphide  oy  that  gas,  washed, 
dissolved  in  nitric  acid,  and  precipitated  with 
sodium  carbonate. 

AUoys  of  eadmllim.  The  addition  of  cad- 
mium  to  metals  usually  increases  their  fusibility 
without  de8tro3'ing  their  malleability. 

The  alloys  with  gold  and  copper  are  brittle ; 
the  others  are  usuuly  ductile  and  malleable. 
With  gold,  a  cr^alune  brittle  silvery  alloy, 
corresponding;  with  AuGd,  has  been  prepared, 
and  uie  existence  of  a  compound,  Au4Cda, 
is  also  indicated.  Alloys,  containing  between 
61  and  63  p.c.  of  cadmium,  are  very  brittle. 
With  platinum,  a  white  crystalline  compound 
appears  to  exist;  and  with  copper  compounds 
OusOd  and  Gu,Gd„  are  indicated.  The  aDoys 
rich  in  cadmium  are  steel-grey  and  soft,  but 
become  harder  and  more  brittle  with  increase  of 
copper  up  to  26*5  p.c,  when  the  hardness  again 
decreases  and  the  yellow  colour  of  copper 
appears.  Researches  by  Rose  on  alloys  of  silver 
and  cadmium  indicate  the  existence  of  the  com- 
pounds AgCdg,  Ag,Cd^  AgCd,  AggCd,,  Ag,Cd, 
and  Ag4Cd.  Alloys  containing  over  80  p.c. 
silver  are  uniform  and  homogeneous,  and  well 
suited  as  material  for  trial  plates  for  silver 
coinage  and  ware,  for  which  the  silver-copper 
aUoy  is  not  quite  satisfactory.  With  sodium 
a  compound,  Gd^Na,  has  been  prepared,  and 
compounds  CdMg  and  CdMgf  are  indicated  in 
the  alloys  with  magnesium.  The  addition  of 
i  p.c.  caamium  to  zinc  increases  the  breaking 
strain,  but  more  than  }  p.c.  has  the  opposite 
ellect.  The  amalgam,  with  mercury,  was 
formerly  used  in  dentistry,  but  its  use  lias  been 
discontinued,  as  it  produces  disoolouration  of 
the  dentine.  Multiple  alloys,  containing  bis- 
muth, frequently  melt  below  100°,  and  are  used 
as  fusible  alloys;  for  these  and  other  allovs  con- 
taining bismuth  and  cadmium,  v,  Auoya  of 
bismnth,  art.  Bismuth.  The  metal  is  occasion- 
ally used  as  a  substitute  for  tin  in  solder. 

Cadmium  oxide  CdO  a  prepared  by  heating 
the  carbonate,  in  which  case  it  is  of  a  pale-brown 
colour;  or  by  igniting  the  nitrate,  when  it  is 
much  darker  and  forms  minute  crystals.  By 
heating  cadmium  in  a  current  of  oxygen,  the 
oxide  may  be  condensed  in  octahedral  crystals  ; 
at  low  temperatures,  some  peroxide  ia  also 
formed  (Manchot).  Cadmium  oxide  is  infusible, 
insoluble  in  water,  soluble  in  acids.  It  con- 
stitutes the  brown  deposit  found  in  the  con- 
densers in  the  distillation  of  zinc. 

Cadmiom  suboxide  CdtO  appears  to  be 
formed  in  small  quantity  when  cadmium  oxalate 
is  heated  in  a  stream  of  carbon  dioxide  (Tanatar, 
Zeitsch.  anoig.  Chem.  1901,  27,  433),  or  when 


cadmium  oxide  is  heated  with  carbon  Konoxido 
(Brislee,  Gbem.  Soo.  Trans.  1908,  93,  162),  or 
by  dehydrating  cadmious  hydroxide,  obtained 
by  the  action  of  water  on  the  product  formed  by 
fusing  oadmium  chloride  with  oadmium  (Moon 
and  Jones,  Amer.  Chem.  J.  1890,  12,  488).  Cf, 
Denham,  Chem.  Soc.  Trans.  1919,  556. 

Cadmium  ehlorlde  CdClg  is  prepared  by 
evaporating  the  solution  of  the  metal  or  oxide 
in  hydrochloric  acid.  It  melts  below  a  red  heat 
and  sublimes  at  a  higher  temperature,  con- 
densing in  micaceous  plates. 

Ca&lum  iodide  Cdlt  is  obtained  hv  digesting 
J  part  of  the  metal  with  2  parts  of  iocune  in 
water  and  evaporating  the  solution.  It  crystal- 
lises in  larse  transparent  tablets,  soluble  in 
water  and  alcohol  It  is  used  in  medicine  and, 
on  account  of  its  stability  and  solubility  in 
alcohol,  for  iodising  collodion  plates  in  photo- 
graphy. 

Cadmium  sulphide.  Cadmium  tfeUow,  Jaun€ 
brillarU,  This  pigment  may  be  produoed  by  the 
addition  of  sulphuretted  hydrogen  or  an  allodine 
sulphide  to  a  solution  of  a  cadmium  salt.  It  may 
also  be  prepared  by  heating  a  mixture  of  cad- 
mium oxide  and  excess  of  sulphur,  but  that  pro- 
duced by  the  former  method  is  of  a  finer  ooloar 
and  has  greater  covering  pawer.  It  may  also  be 
formed  by  the  action  of  hydrogen  sulphide  on 
cadmium  vapour.  The  various  hues  of  different 
preparations  depend  on  whether  the  substance 
is  crystalline  or  amorphous,  and  on  the  size  and 
natim  of  the  surface  of  the  grains. 

It  is  an  oranffe-  or  lemon-ydlow  powder,  but 
may  be  obtained  in  prismatic  dystals  of  sp.gr. 
4*82.  When  heated  to  redness,  it  becomes  first 
brown,  then  carmine ;  it  melts  at  a  bright-rod 
heat,  and  solidifies,  on  cooling,  in  liMinmy»  of  the 
original  colour. 

It  is  a  very  brilliant  permanent  colour. 
According  to  Jacquet,  it  is  acted  upon  by  light 
and  by  chlorine.  It  is  much  used  as  an  oil 
and  water  colour,  for  colouring  certain  toilet 
soaps,  for  the  production  of  a  blue  flame  in 
pyitotechny,  and  in  calico  printing.  The  ohief 
adulterants  are  compounds  of  dna  Aooording 
to  Buchner  (Chem.  Zentr.  15, 329),  two  modifica- 
tions exist:  (1)  the  a- variety,  precipitated  hy 
hydrogen  sulphide  in  faintly  acid  solution;  it 
is  lemon-yellow,  and  possesses  good  covering 
power.  When  heated,  it  darkens  temporarily 
to  violet-red,  but  no  permanent  change  ooootb 
unless  the  temperature  is  high  enough  to  produce 
oxidation.  (2)  The  j8-variety,  produced  in 
strongly  acid  solution;  it  resembles  red  lead, 
possesses  good  coverii^  power,  and  is  ordinarily 
quite  permanent;  if  heated,  it  changes  to  th» 
a-variety.  Various  shades  are  obtainable  by 
mixture.  The  sulphide  can  also  be  obtained  in 
colloidal  solution. 

Schmid  (DingL  poly.  J.  241,  149),  prepares  a 
steam  yellow  for  calico-printing  as  follows :  16 
parts  wheaten  stareh  and  40  parts  burnt  starch 
are  boiled  in  1000  parts  of  water  and  mixed 
while  hot  with  350  parts  of  sodium  thiosnlphate. 
To  the  cooled  solution,  350  parts  of  finely 
powdered  cadmium  nitrate  are  added  with  con- 
stant stirring  until  dissolved.  This  solution 
does  not  react  in  the  cold,  and  mav  be  applied 
to  the  fabric  and  steamed,  the  yellow  sulphide 
being  then  precipitated. 

Cadmium  suiplMrte  CdS04,4H|0  is  a  very 


CAFFEINE  AND  THE  ALKALOIDS  OF  TFA«  COFFEE,  AND  COCOA.        725 


soluble  salt  prepared  by  dissolymg  the  oxide  or 
carbonate  in  stilphurio  acid.  It  is  used  to  some 
extent  in  medicine  in  place  of  zinc  sulphate, 
especially  on  the  Continent.  It  is  idso  used  in 
the  construction  of  the  Weston  cell  as  a  standard 
of  E.M.F.  The  cell  is  usually  made  in  the  form 
of  an  H.  One  of  the  limbs  contains  mercury, 
covered  by  a  paste  of  cadmium  and  mercurous 
sulphates.  The  other  contains  cadmium  amal- 
sam.  Above  both,  to  nearly  the  top  of  the 
Bmbe,  which  are  closed  by  cork  and  wax,  is  a 
saturated  solution,  with  crystals  of  cadmium 
sulphate.  Through  the  glass  of  the  lower  limbs, 
platinum  wires  pass.  The  cell  has  an  E.M.F. 
of  1*019  volts  at  15*'-I8'',  and  has  the  advantage 
of  a  very  low  temperature  coefficient. 

Forms  a  double  salt  with  ammonium  sulphate 
CdS04(NH4),SO«6HaO.  A  salt  of  the  composi- 
tion 2CdS04(NH  4)1804,  hygroscopic,  microscopic 
crystals,  yellow  when  hot,  white  when  cold,  of 
sp.gr.  3*11  at  22®  is  also  known  (Veres,  Compt. 
rend.  1914,  168,  39). 

Cadmium  nitrate  Cd(NOa)i,4HsO  is  prepared 
by  dissolving  the  oxide  or  carbonate  m  nitric 
acid.  It  crvstallises  in  deliquescent  fibrous 
needles,  soluble  ia  alcohol. 

CSadmhim  salleylate  is  prepared  from  the  acid 
and  oxide  or  carbonate.  It  is  readilv  soluble  in 
alcohol,  ether,  or  glycerol,  and  is  used  in 
medicine  as  an  external  antiseptic. 

CASIUM.  Symb.  Cs.  At  wt.  132*8. 
Cesium  was  discovered  in  1860  by  Bunsen  and 
Eirohhoff,  in  the  Diirkheim  water,  being  the  first 
element  detected  by  means  of  the  spectroscope. 

It  is  widely  but  sparsely  distributed,  usually 
in  association  with  rubidium,  as  in  the  lepidolUe 
from  Hebron  in  Maine,  U.S. A.,  which  contains 
0*4  p.c  cosium  oxide  and  0*2  p.c.  rubidium 
oxide ;  in  petalUe ;  in  the  mother  liquors  of  the 
Nauheim  salt  spring,  and  in  the  ash  of  seaweed, 
tobacco,  tea,  and  other  plants.  Setterbeig 
(Annalen,  210,  100)  describes  a  method  for  the 
separation  of  cesium  and  rubidium  from  the 
alums  obtained  as  a  by-product  in  the  manu- 
facture of  lithia  from  lepidolite.  For  observa- 
tions on  the  solubilities  of  cesium  alum,  8ee 
Hart  and  Huselton  (J.  Amer.  Chem.  Soc.  1914, 
36,  2082).  For  details  of  the  method  of  separa- 
tion of  cesium  and  rubidium  by  fractional 
orystalliBation  of  the  aluminium  and  iron  slums, 
see  Browning  and  Spencer  (Amer.  J.  Sd.  1916, 
42,  279).  Cesium  and  rubidium  chlorides  are 
also  obtained  from  camallite  by  repeated 
fractional  crystallisation.  The  cesium  is  sepa- 
rated from  the  rubidium  by  the  addition  of 
antimony  chloride,  which  precipitates  only 
the  cesium  in  the  form  of  the  double  salt 
SbCl,*6CsCl  (Fiet  and  Kubeirscky). 

Cesium  occurs  free  from  rubidium  in  the 
rare  mineral  poUucUe,  horn  Elba,  to  the  extent  of 
34  p.c.  of  cesium  oxide ;  to  the  extent  of  1*71 
parts  of  cesium  chloride  per  million  in  the  water 
of  the  Wheal  Clifford  Mine  (Yorke),  and  in  the 
mineral  waters  of  Frankhausen. 

Cesium  may  be  prepared  by  electrolysis  of 
a  fused  mixture  of  cesium  cyanide  4  parts  and 
barium  cyanide  1  part,  using  electrodes  of 
aluminium  (Setterbers).  It  is  more  readily  ob- 
tained by  heating  the  nydroxide  with  aluminium 
in  a  nickel  retort^  and  condensing  the  metal  in 
a  dass  receiver  (B^^toff) ;  or  1^  heating  the 
omonate  or  hydrate  witii  magnesium  in  a 


current  of  dry  hydrogen  (Graebe  and  Eckhardt). 
A  more  rapid  method,  giving  a  better  yield,  is 
stated  to  be  the  reduction  by  calcium ;  3  grams 
of  this  metal  in  small  pieces  with  12  grams  of 
cesium  chloride  are  heated  in  a  wide  inverted 
Y-tube,  the  vertical  limb  being  connected  to  a 
Sprengel  pump.  Reduction  occurs  at  about 
400**,  and  the  cesium  volatilises  and  condenses 
in  the  vertical  tube.  It  resembles  rubidium  and 
potassium  in  appearance,  being  silvery  white, 
and  soft  at  ordinary  temperatures.  It  quickly 
oxidises  in  air,  and  decomposes  water  at  —116* 
with  ignition  of  the  liberated  hydrogen  at  higher 
temperatures.  Its  sp.ffr.  at  16*  is  1*88,  1*9029 
(Hackspill,  Compt.  rend.  1911,  162),  its  melting- 
point  is  26*-27*  (Setterbeig) ;  28*46*  (Rengade, 
Comnt.  rend.  1913,  166,  1897). 

The  coefficient  of  expansion  of  the  soUd 
metal  is  0000291,  of  the  liquid  metal  0*000346 
between  28*  and  60*  (Haolupill,  2.C.).  Specific 
heat  (solid)  0*0622 -f  0*000137^  ;  liquid  0*0604- 
0*000034*;  heat  of  fusion  3*766 ;  ratio  of  atomic 
heat  of  fusion  to  abs.  m.p.sl-66  (Rengade). 

Cesium  is  the  most  electro-positive  of  all  the 
elements.  Its  salts  are  stable,  and  have  a  strong 
tendency  to  form  double  salts.  The  salts  are 
isomorphous  with  those  of  potassium  and 
rubidium,  and  impart  a  more  reddish  tinge  to 
the  bunsen  flame  than  salts  of  those  metals. 
The  hydroxide  CsHO  is  a  greyish-white  highly 
deliquescent  solid,  melting  below  a  red  heat. 
The  oxide  Cs,0  is  prepared  by  exposing  the 
metal  to  insufficient  oxygen  and  distilling  off 
excess  of  cesium  ;  a  peroxide  CsO^  is  formea  by 
heating  to  300*  in  excess  of  oxygen  (Rensade). 
For  its  absorption  spedrum,  see  Bevan  (Proo. 
Roy.  Soc.  1911,  86,  A,  64). 

C  AFFEARIMB.  Found  in  the  mother  liquors 
of  caffeine  from  coffee  berries ;  is  identical  with 
trigonelline  (^.v.)  (Gorter,  Aimalen,  1910,  372, 
237). 

CAFFEINE  AND  THE  ALKALOIDS  OF 
TEA,  COFinBE,  AND  COCOA.  The  chief  alka- 
loids of  practical  importance  in  this  series  are 
caffeine  CgHi0OaN4,  theobromine  C7Hb0*N4, 
and  theophylline  CfHsOaNA.  Adenine  C.H5N1 
xanthine  C|ti40«N4,  and  hypoxanthine  C^40N4 
have  also  been  found  in  tea  in  small  amounts. 

These '  alkaloids  are  all  derived  from  a 
parent  substance  purine  C,H4N4,  which  has 
not  been  found  occurring  naturally,  but  was 
^thesised  by  Fischer  (Ber.  1898,  31,  2660). 
Derivatives  of  purine  occur  widely  distributed 
in  plants  and  animals.  Of  these,  uric  acid 
(2:6: 8-trioxypurine)  C^H40sN^  is  of  con- 
siderable importance,  as  it  is  usea  in  the  indus- 
trial manufacture  of  the  alkaloids  of  this  series ; 
guano,  in  which  it  occurs  in  considerable  quan- 
tities, being  the  source  from  which  it  is  obtained. 
The  constitution  of  these  compounds  and  their 
relationship  to  purine  and  to  each  other  will 
be  considered  in  detail  below. 

Caffeine  CgHjo^t^A  ^  the  principal  alkaloid 
of  tea  and  coffee  and  of  similar  stimulants,  such 
as  kola  (West  Africa),  mat6  or  Paraguay  tea, 
and  guarana  (both  used  in  South  America). 

Average  samples  of  tea  leaves  contain  from 
2*6  to  3  p.c.  of  caffeine,  though  some  varieties 
may  contain  as  much  as  4  p.c.  Coffee  beans, 
in  which  caffeine  occurs  partly  free  and  partly 
as  potassium  caffeine  chlorogenale,  rarely  con- 
tain more  than  1*6  p.o.  (v.  BulL  Imp.  Inst. 


726         CAFFEINE  AND  THE  ALKALOIDS  OF  TEA.  COFFEE,  AND  COCOA. 


1008,  6,  1).  Mat6  contains  from  1  to  2  p.o., 
guarana  paste  from  3  to  4  p.o.,  and  kola  about 
3  p.c.  of  caffeine.  Only  very  small  amounts 
occur  in  cocoa  beans  (Schmidt^  Annalen,  1883, 
217,  306). 

Caffeine  is  obtained  industrially  almost 
entirely  from  tea  dust  or  damaged  tea.  The 
material  is  *  denatured'  by  addition  of  about 
10  p.o.  of  slaked  lime  and  0*1  p.o.  of  assafcstida. 
The  well-mixed  material  is  then  extracted 
either  with  boiling  water  or  more  usually  with 
hot  alcohol  in  a  reflux  apparatus.  The  extrac- 
tion is  repeated  ihxee  or  four  times,  the  extracts 
combined,  and  the  solvent  recoTered  by  dis- 
tillation. The  residual  liquid  is  treated  with 
lithaige  or  lead  acetate,  avoiding  excess;  the 
precipitate  is  filtered  off,  and  the  filtrate  con- 
centrated^  when  caffeine  crystallises  out  on 
cooling.  The  product  is  pureed  by  recrystal- 
lising,  decolourising  with  ohareoal,  &c.,  when 
necessary,  or  by  siublimation. 

An  utemative  method  sometimes  employed 
consists  in  the  exhaustive  pereolation  of  the 
denatured  tea  by  means  of  hot  benzene.  The 
concentrated  extract  is  freed  from  benzene,  the 
residue,  consisting  of  caffeine,  together  with 
fatty  and  resinous  material,  is  boiled  with 
water  and  filtered  from  insoluble  material 
On  concentrating  the  filtrate  caffeine  crystal- 
lises out,  and  may  be  purified  by  the  methods 
described  above. 

Caffeine  is  also  a  by-product  obtained  in  the 
manufiicture  of  '  caffeine  free  *  coffee,  and  is 
further  manufactured  synthetically  from  uric 
acid  {see  below).  For  the  preparation  of  small 
quantities  of  caffeine,  100  grams  of  tea  dust  is 
extracted  three  or  four  times  with  boiling  water. 
The  extracts  are  combined,  10-15  grams  of 
magnesia  added,  and  the  mixture  taken  to 
dryness.  The  residue  is  transferred  to  a  Sohxlet 
apparatus  and  extracted  with  chloroform. 
On  evaporating  off  the  solvent  a  somewhat 
impure  caffeine  remains,  which  may  be  purified 
by  crystallisation  from  water  or  by  sublimation. 

Caffeine  crystallises  from  water  with  IHyO, 
from  alcohol  anhydrous,  in  long  silky  needles. 
It  loses  water  at  100^,  and  when  anhydrous 
melts  at  234*'>235^  It  sublimes  readily  at 
about  180^ 

One  part  by  weight  of  caffeine  dissolves  in 
60  parts  of  alcohol  (90  p.c.),  300  parts  of  ether, 
9  parts  of  chloroform,  or  80  parts  of  water  at 
about  15*^.  It  is  very  soluble  in  hot  water 
(1:2),  so  that  a  hot  concentrated  aqueous 
solution  on  cooling  sets  to  a  solid  crystalline 
mass.  Its  aqueous  solution  reacts  neutral  to 
litmus. 

Caffeine  is  a  weak  base.  Its  salts  are  dis- 
sociated on  evaporation  of  their  aqueous  solu- 
tions, and  the  free  base  may  be  obtained  from 
acid  solutions  by  shaking  with  chloroform. 
Certain  double  lalts  of  caffeine  are  more  stable ; 
the  mereuriohloride  B*HgClg  forms  colourless 
needles,  m.p.  246* ;  the  aurichloride  B'HAuCHf* 
2H.0,  m.p.  243"*  (2485*  anhydrous),  on  warming 
with  water  forms  an  amorphous  ycdlow  precipi- 
tate *  anrichlorcaffeine  *  CsH9(Au(I3,)0^4,  m.p. 
207*  (Dunstan  and  Shepheard,  Chem.  Soc.  Trans. 
1893,  63,  198).  For  other  caffeine  salts,  see 
Niohokoii  (AnnalBn*  62,  71)  and  Schmidt 
{ibid.  1883,  217,  283  ;  and  Ber.  1881,  14,  813). 

Caffeine  citrate,  largely  used  in  medicine,  is 


obtained  by  evaporating  an  aqueous  aolutioa  of 
equimoleciuar  proportions  of  oafffsne  and  citric 
acid  to  dnness.  It  forms  a  white  powder 
easily  soluble  in  water.  Similar  compounds  are 
caffeine  sodio  salicylate  and  benzoate»  which  are 
also  used  medicinally. 

Caffeine  dissolves  without  colouration  in 
concentrated  sulphuric  acid  or  cold  ooncenteated 
nitric  add.  If  to  the  solution  in  sulphuric  acid 
a  crystal  of  potassium  dichromate  be  added  a 
green  colouration  is  produced.  CJaffeine,  in 
common  with  the  other  alkaloids  of  this  group, 
gives  the  murexide  reaction.  If  a  small  quan- 
tity of  the  base  be  moistened  with  concentrated 
hydrochloric  acid  a  crystal  of  potassium  chlorate 
added  and  the  mixture  evaporated  to  dryness, 
a  reddish-brown  residue  is  obtained,  which,  on 
moistening  with  dilute  ammonia,  gives  a  fine 
reddish-purple  colouration. 

Caffeine  in  dilute  acid  solution  is  precipi- 
tated by  phosphomolybdic  and  phoephotungstic 
acids  ana  by  potassium  bismuth  iodide,  with 
tannic  acid  a  precipitate  is  formed,  which  is 
soluble  in  excess  of  the  reagent  No  precipitate 
is  obtained  with  Mayer's  reagent  or  iodine  in 
potassium  iodide. 

Esiimaiion.  A  very  large  number  of  pro- 
cesses have  been  suggested  from  time  to  time 
for  the  estimation  of  caffeine  in  tea,  coffee,  &a, 
and  widelv  divergent  results  have  been  obtained 
with  methods  dBfering  only  in  minor  details. 
This  appears  to  be  due,  in  many  cases^  to 
unsatisfactory  preliminary  treatment  of  the 
material  under  investigation,  the  caffeine  not 
being  set  free  from  the  complex  compounds 
(e.^.  caffeine  potassium  chlorogenate)  in  which 
it  occurs  naturally. 

Stahlschmidt's  process,  as  modified  by  Alien, 
appears  to  give  satisfactory  results,  and  is 
carried  out  as  follows  : — 

Six  grams  of  finelv-powdered  tea  are  boiled 
under  reflux  with  500  c.c.  of  water  for  ^S 
hours.  The  decoction  is  then  filtered  and  the 
residue  washed  with  hot  water  until  the  volume 
of  the  filtrate  and  washings  is  600  0.0.  The 
solution  is  then  heated  nearly  to  boiling,  4 
grams  of  lead  acetate  added,  and  the  mixture 
boiled  under  reflux  for  10  minutes.  If  the  pre- 
cipitate does  not  coagulate  and  aettle  down 
readily  more  lead  acetate  is  added  and  the 
boiling  repeated.  The  liquid  is  filtered,  500 
C.C.  evaporated  to  40  cc,  and  the  caffeine 
extracted  by  «hAlring  vith  chloroform.  On 
evaporatine  off  the  solvent  caffeine  remains 
behmd  and  is  weighed.  Tatlock  and  Thomson 
(Analyst,  1910,  35,  105)  boil  2  grams  of  tea  with 
8(X)  cc.  of  water  for  one  hour,  filter  and  evanorate 
to  small  bulk.  The  solution  is  made  alkaline 
with  caustic  soda,  and  the  caffeine  extracted 
by  shaking  with  chloroform.  This  method  is 
said  to  give  results  identical  with  those  obtained 
by  more  complicated  processes.  Other  methods 
in  use  are  due  to  Paul  and  Cownley  (Pharm.  J. 
1887,  (iii.)  18,  417);  Dvorkowitsoh  (Ber.  1891, 
24, 1945) ;  Keller  (Ber.  Deut  pharm.  Ges.  1897, 
7,  105) ;  Power  and  Chesnut,  J.  Amer.  Chem. 
Soc.  1919,  41,  1298 ;  and  for  the  estimation  of 
caffeine  in  coffee  a  modification  of  the  last 
method  by  Katz  {ibid.  1902,  12,  250). 

Theobromine  Cfi/)^g  is  the  principal 
alkaloid  found  in  cocoa  beans  in  which  it  is 
present  to  the  extent  of  about  1*5-20  p.e. 


CAFPHINE   AND  THE   ALKALOIDS  OF  TEA,  COFFEE,  AND  (XKJOA.        727 


It  also  occuiB  in  small  quantities  in  kola  nuta 
and  leaves,  in  guarana,  and  in  tea. 

For  the  preparation  of  theobromine  the 
cocoa  beans  (commercially  the  husks  which 
contain  about  0*5-1  p.c.  of  theobromine  are 
employed)  are  freed  from  fat  as  far  as  possible, 
either  by  pressure  or  by  extraction  with  light 
petroleum,  the  residue  mixed  with  half  its 
weight  of  slaked  lime,  and  the  mixture  exhausted 
by  boiling  alcohol  (80  p.c.).  A  considerable 
portion  of  the  theobromine  separates  on  cooling, 
and  is  filtered  off.  The  filtrate  is  then  acidified, 
the  alcohol  removed  by  distillation,  the  residual 
liquid  filtered  hot,  and  the  filtrate  neutralised. 
Theobromine  separates  as  a  yellowish-white 
crystalline  jpowder.  The  product  is  purified  by 
crystallisation  from  boiling  water  or  alcohol, 
but  best  from  hot  glacial  acetic  acid.  On  the 
large  scale  purification  is  most  readily  achieved 
by  dissolving  in  alkaline  solution  and  roprecipi- 
tatinff  by  addition  of  acid. 

Theobromine  forms  a  white  oiystalline 
powder  which  sublimes  unchanged  at  about 
290**,  and  melts  at  329''-3d0''.  It  is  very  spar- 
ingly soluble  in  water  and  most  organic  solvents. 
It  is  soluble  in  about  20  parts  by  weight  of 
boiling  glacial  acetic  acid,  from  which  it  separates 
almost  completely  on  cooling.  It  behaves  both 
as  a  weak  oase  and  on  acid.  The  hydrochloride 
B-HCl,HsO  is  ciystalline,  and  is  obtained  by 
dissolving  theobromine  in  hot  concentrated 
hydrochloric  acid  and  cooling  the  solution. 
On  drying  at  lOO®  the  free  base  is  obtained. 
Theobromine  dissolves  in  dilute  nitric  acid,  and 
treated  with  silver  nitrate  slowly  forms  a  com- 
pound CjrHa0aN4HN0,AgN0g ;  if,  however, 
theobromine  be  dissolved  in  dilute  ammonia, 
silver  nitrate  added,  and  the  solution  then 
boiled,  a  white  ^^stalline  precipitate  of  silver 
theobromine  C-fiLiOfNiAg'l'dKfi,  which  is 
almost  insoluble  in  water,  is  obtained.  Theo- 
bromine also  forms  a  calcium  salt,  >Mrluch  can  be 
oiystallised  from  water. 

Theobromine  gives  the  murexide  reaction, 
and  is  predpitatMl  by  the  usual  alkaloid  pre- 
cipitanto,  with  the  exception  of  Mayer*s  reagent. 

The  base  finds  employment  in  medicine 
chiefiy  as  a  diuretic,  and  for  this  purpose 
numerous  soluble  compounds  of .  theobromine 
have  been  produced.  Chief  among  these  may 
bo  mentioned  Diureiin  (theobromine  sodium 
salicylate),  prepared  by  dissolving  theobromine 
in  the  calculated  equivalent  amount  of  caustic 
soda  solution,  adding  a  molecular  proportion 
of  sodium  salicylate  and  evaporatir^  the 
solution  to  dryness  in  vcunto.  UropJierin  (theo- 
bromine lithium  salicylate),  Uropherin-B  (theo- 
bromine lithium  benzoate),  and  BartUin  (barium 
theobromine  sodium  salicylate),  &c.,  are  com- 
pounds of  the  same  type. 

EsiinuUion.  Q^ie  following  process,  due  to 
Dekker  (Reo.  trav.  ohim.  1903,  22,  143),  is 
generally  employed  for  the  estimation  of 
theobromine  in  cocoa  and  similar  products  (e/. 
IMbourdeaux,  J.  Pharm.  ChinL  1917,  15,  306). 

Ten  ^pnana  of  the  powdered  material  is 
nuxed  with  5  grams  of  magnesia  and  boiled 
under  reflux  for  one  hour  with  300  c.c.  of  water. 
The  extract  is  filtered  off  and  the  extraction 
repeated  for  fifteen  minutes  with  a  fresh  quantity 
ox  water.  The  filtrates  are  combined  and 
evaporated  to  dryness  on  the  water-bath.    The 


residue  is  mixed  with  sand,  the  material  trans- 
ferred to  a  Soxhlet,  and  completely  extracted 
with  chloroform.  On  evaporation  of  the 
solvent  theobromine  remains,  and  is  dried  and 
weighed. 

A  method  for  the  estimation  of  theobromine 
depends  upon  the  formation  of  its  periodide 
C7HsOaN4,HI,l4.  0*1  gram  of  the  sample 
with  an  equivalent  quantity  of  sodium  acetate, 
is  dissolved  in  2  cc.  of  glacial  acetic  acid,  5  c.c. 
of  hot  water  are  addM,  and  the  solution  is 
transferred  to  a  100  c.o.  fiask  containing  60  cc. 
of  i^/10-iodine  solution;  20  o.c.  of  saturated 
sodium  chloride  solution  and  2  cc.  of  cone 
hydrochloric  acid  are  added,  and  after  about 
18  hours,  the  mixture  is  diluted  to  100  cc, 
filtered,  and  the  excess  of  iodine  titrated  in 
an  aliquot  portion  of  the  filtrate  (Emery  and 
Spencer,  J.  Ind.  Eng.  Chem.  1918,  10,  60i3). 

Theophylline  CfHsOtNt,  isomeric  with  theo- 
broimne,  is  of  much  less  importance  than 
theobromine  and  caffeine.  It  was  found  in 
smaU  quantity  in  tea  by  Kossel  (Zeitsch.  physioL 
Chem.  1889,  13,  298),  and  was  obtained  from 
the  mother  liquors  from  which  caffeine  had 
ciystalUsed  out.  The  complete  isolation  was 
effected  as  follows : — 

The  mother  liquors  were  diluted  with  water, 
acidified  with  dilute  sulphuric  acid,  and  filtered 
after  standing  for  some  time.  The  filtrate  was 
made  alkaline  with  ammonia,  silver  nitrate 
added,  and  the  mixture  allowed  to  stand  24 
hours.  The  precipitate  was  collected  and  dis- 
solved in  warm  dilute  nitric  acid.  On  cooling 
the  silver  compounds  of  adenine  and  hypoxan- 
thine  ciystaUued  out.  To  the  filtrate  from 
these  ammonia  was  added,  and  silver  theophyl- 
line was  precipitated.  The  precipitate  was 
decomposed  by  sulphuretted  hydrogen,  and  on 
concentrating  the  nitrate  xanthine  and  finally 
theophylline  crystallised  out.  Further  quanti- 
ties were  obtained  from  the  mother  liquor  by 
precipitation  with  mercuric  nitrate  and  decom- 
position of  the  mereury  precipitate. 

Theophylline  ciystalUses  with  IH^O  in 
thin  plates  or  needles,  m.p.  264®.  It  is  sparingly 
soluble  in  cold,  readily  soluble  in  hot,  water  or 
alcohol.  It  behaves  as  a  weak  base,  and  yields 
salts  with  acids  and  derivatives  with  metals. 
It  gives  the  murexide  reaction,  and  in  general  is 
very  similar  to  theobromine  It  forms  soluble 
double  salts,  of  which  theoevn  (sodium  theo- 
phylline sodium  acetate)  has  been  successfully 
emploved  in  medicine  as  a  diuretic. 

Adenine  C.H,Nf  (6-aminopurine),  as  men- 
tioned above,  has  beien  found  in  small  quantities 
in  tea.  It  ciystallises  with  3H|0,  sublimes  at 
250'',  and  melts  at  360''-^66''.  It  is  sparingly 
soluble  in  cold,  readily  soluble  in  hot,  water. 
The  picrolonate,  m.p.  265®,  crystallises  from 
water.  Adenine  has  been  synthesised  by 
Fischer  (Ber.  1897,  30,  2226),  and  by  Traube 
(Annalen,  1904,  331,  64). 

Hypoxanthine  CJE4ON4  (6  -  oxypurine), 
needles,  m.p.  150®,  was  found  in  small  quantities 
in  tea  (Kossel,  l.c),  Kruger,  however  (Zeitsch. 
physioL  Chem.  1895,  21,  274),  suggests  that  it 
was  produced  from  adenine  by  the  method  of 
isolation  employed.  It  is  a  weak  non-aoid  base 
and  forms  metallic  derivatives.  It  is  sparingly 
soluble  in  cold,  rather  more  readily  soluble  in 
hot,  water. 


728         CAFFEINE  AND  THE  ALKALOIDS  OF  TEA,  COFFEE,   AND  COCOA. 


Xanthine  CfifiJ^^  (2  :  6-dioxypurine)» 
found  to  be  present  in  tea  (KosBel*  Lc),  has 
Bimilar  properties  to  hypozanthine. 

Cbnstitatloii  and  Oynthesb  of  Caffeine, 
Theobromine,  and  Theophylline.  It  has  been 
mentioned  preyiouslv  that  the  alkaloida  desoiibed 
above  are  closely  related  members  of  a  group  of 
bases  derived  from  a  parent  substance  purine, 
which  has  the  constitution  denoted  by  the 
formula  shown  (Fischer,  Ber.  1898,  31,  2550). 

(1)    N=CH  (6) 

(2)  HO    C(5)-NH  (7) 

(3)  N-C(4)-N(9)/^^  <®* 

Caffeine,  theobromine,  and  theophylline  are, 
in  fact,  methylated  derivatives  of  xanthine, 
which  itself  is  2  :  6-diozypurine.  Theobromine 
and  theophylline  are  dimethvl  xanthines,  from 
which  caffeine  and  trimeUiyl  xanthine  may  be 
obtained  by  methylation.  Thus  caffeine  is 
formed  when  silver  theobromine  is  heated  with 
methyl  iodide  (Strecker,  Annalen,  1861,  118, 
170),  by  heating  potassium  theobromine  with 
methyl  iodide  at  100°  (E.  Schmidt,  Annalen, 
217,  295),  or  by  the  action  of  dimethyl  sulphate 
upon  theobromine  in  alkaline  solution  (tJlt^e, 
Chem.  Wkbld.  1910,  7,  32).  The  silver  com- 
pound of  theophylline,  on  treatment  with  methyl 
iodide,  similany  yields  caffeine. 

Our  knowledge  of  the  constitution  of  the 
purine  derivatives  is  laigely  due  to  the  work  of 
Fischer.  One  of  the  most  important  members 
of  the  series  is  uric  acid  2:6:  8-trioxypurine, 
which  occurs  naturally  in  large  quantities  in 
guano  and  serves  as  a  starting-point  for  the 
synthetic  manufacture  of  the  alkaloids  under 
consideration. 

The  synthesis  of  uric  acid  was  accomplished 
by  Fischer  and  Ach  (Ber.  1895,  28,  2473). 
Malonio  acid  was  condensed  with  urea  to  form 
malonyl  carbamide  (I.),  which,  by  the  action  of 
nitrous  acid,  yields  an  Monitroeo  derivative 
violurio  acid  (II.).  On  reduction  uranul  (III.)  is 
obtained,  which  by  the  action  of  potassium 
^anate  is  converted  into  patudo  uric  acid  (IV.). 
This,  on  treatment  with  hot  dilute  acid,  gives 
uric  acid  (V.). 


HN-CO 
OC    CH, 
HN— CO 


NH-CO 


oi 


C:NOH 


HN-CO 


HN—CO 
U. 


CHNH, 


HN 


—CO 


IlL 


NH-CO 

CO    c- 

liH-C- 
V. 


NH\ 


NH/ 


)C0 


HN-CO 

OC    CHNHCONH, 

I      I 
HN-CO 

IV. 

From  uric  acid  caffeine  is  manufactured 
syntheticallv  by  the  following  reactions  (Boeh- 
ringer  u.  Sonne,  D.  B.  P.  121224).  Uric  acid  is 
converted  by  heating  with  acetic  anhydride 
into  8-methvlxanthine  (VI.).  This,  on  methyla- 
tion in  alkaline  solution,  gives  1:3:7:8- 
tetramethylxantlune  (VII).  By  the  action  of 
chlorine  under  specified  conditions  this  is  con- 
verted into  a  tnchloro  derivative  of  the  con- 
stitution shown  in  formula  (VIII.)  which,  on 


heating  with  dilute  caustic  potash  solution, 
yields  caffeine  (IX.)  Under  slightly  different 
conditions  a  tetrachlor  derivative  (X.)  is  ob- 
tained, which  on  treatment  with  potash  yields 
theophylline  (XL). 

NH-CO  NMe-CO 

CO    C-NHv  CO      C-NMev 

II  >CMe  I  II  V'Me 

H-C-N    ^  NMe-C-N     ^ 


d 


VL 


VII. 

NMe-CO 

I        I 
CO      C-NMev 


NMe-CO 

CO      C-NMev 

J         II  >CC01,     I         II  >C0 

NMe-C-N     ^  NMe-C-N    ^ 

Vm.  IX. 

NMe-430  NMe      CO 

CO        C— NCH,av  CO     C— NHv 

1       II     .        >c-oci,  I       II       >;h 

NMe-C-N  ^  NMe-C-N  ^ 

X.  XI. 

Theophylline  (XI.)  is  also  obtained  commer- 
cially from  dimethyl  carbamide  (Tranbe,  Ber. 
1900,  33,  3036).  This  is  condensed  with  cyan- 
acetic  acid  in  presence  of  phosphoryl  chloride 
and  gives  dimethylimino  barbituric  acid  (XII.), 
which  by  the  action  of  nitrous  acid  yields  an 
oximino  derivative  (XIII.).  On  reduction  a 
dimethyl-diamino-dioxy-pyrimidine  (XIV.)  is 
produced,  which  with  formic  acid  yields  a 
formyl  derivative  (XV.).  Tins  on  heating  loses 
water  with  formation  of  theophylline  (XI .). 


NMe-CO 
CO      CH, 


NMc-C; 


NH 


xn. 


NMe-CO 

CO      CNH, 

J         il 
NMe— CNHj, 

XIV. 


NMe-CO 
CO      C :  NOH 
NMe-C:NH 

xm. 

NMe-CO 

do 


CNHCHO 


J         » 
NMe- 


CNH, 
XV. 


Theobromine  has  been  synthesised  by  a 
series  of  reactions  similar  to  those  above. 
Starting  with  methyl  carbamide  3-methyl- 
xanthine  (XVI.)  is  obtained,  which  on  methyla- 
tion gives  theobromine  XVII. 


NH  -CO 

I  I 

CO      C-NHv 

I  II  >H 

NMe-C-N    ^ 

XVI. 


NH  —CO 

CO      C-NMev 

l}Me-C-N    ^ 
XVIL 


Theobromine  may  also  be  obtiained  syntheti- 
cally from  uric  acid.  This  is  converted  into 
8-methylxanthine  (VI.)  as  in  the  caffeine  synthe- 
sis.  The  diydipotassium  salt  of  8-methylxanthine 
IB  heated  with,  methyl  iodide  when  trimethyl 
xanthine  (XVIII.)  is  obtained.  Chlorination  of 
this  compound  results  in  the  formation  of  a 
trichloro  derivative  (XIX.),  which  on  heating 
with  dilute  caustic  potash  solution  yields 
theobromine  (XVII.). 


CALCITB  OR  OALOSPAR. 


729 


NH-CO 

CO    C-NMev 
I         II  >CMe 

NMe-C-N    ^ 

XVUL 


NH-CO 


CO 

I        II 
NMe 


-C-N     ^ 


NMe^ 


COCl, 


XIX 


A.  J.  E. 


CAFFEONE  (Caffed),  A  brown  oU,  heavier 
than  water,  and  slightly  soluble  in  boiUng  water. 
Constitutes  the  aromatic  princk>le  of  co£fee. 
May  be  obtained  by  Hiwtilfing  fieshly  roasted 
coffee  with  water,  and  agita&ig  the  distillate 
with  ether,  which  dissolves  out  the  oiL  Accord- 
ing to  Lehmann  and  Wilhehn  (Chem.  Zentr. 
1898,  ii  372),  it  has  no  physiological  action  on  a 
healthy  man  (v.  Coffxb).  According  to  Grafe 
(Monatsh^  1912,  33,  1389),  it  consisto  of  about 
60  p.0.  of  furfuryl  alcohol  and  38  p.c.  of  valeric 
and  acetic  adds,  with  phenolic  sulxitances  of 
a  creosote  odour  and  a  nitrogenous  substance 
allied  to  pyridine  to  which  the  aroma  is  due. 
It  appears  to  be  formed  by  the  distUlation  of 
the  crude  fibre  of  the  bean. 

CAFFETANMIC  ACID  v.  TAznnNS. 
^  CAIL-CEDRA,  Khaya  aenegalensia  (A. 
Juss.).  A  tree  of  the  meliaceous  order,  growing 
on  the  banks  of  the  Gambia  and  on  the  lowlands 
of  the  peninsula  of  Cape  de  Verde.  Its  bark  is 
very  bitter,  and  is  much  prized  by  the  natives  as 
a  febrifuge,  on  which  account  it  has  been  called 
the  cinchona  of  Senegal.  Its  wood  resembles 
American  (Honduras,  Cuba,  Spanish)  mahogany, 
is  one  of  the  so-called  African  mahoganies,  and 
is  used  in  making  the  finer  kinds  of  furniture. 
The  bark  contains,  amongst  other  substances, 
an  extremely  bitter,  neutral  resinous  substance, 
called  call-cedrin,  to  which  its  active  properties 
appear  to  be  due. 

Cati-c^edrin  ia  very  sparingly  soluble  in  water, 
but  readily  soluble  in  alcohol,  ether,  and  chloro- 
form. It  is  obtaiued  by  repeatedly  exhausting 
the  coarsely  pulverised  bark  with  boiling  water ; 
evaporating  the  filtered  liquids  over  the  water- 
bath  to  the  consistence  of  a  syrup ;  exhausting 
this  extract  with  alcohol  of  90  p.c. ;  precipitating 
the  alcohol  filtrate  with  biuic  lead  acetate; 
filtering,  distilllTig  off  the  alcohol,  and  agitating 
the  residue  with  chloroform,  which  mssolves 
nothing  but  the  bitter  principle.  1  kilogram  of 
the  bark  yields  about  8  miU^^ms  of  cfJlcedrin 
(Caventou,  J.  Pharm.  [3]  16,  366 ;  33,  123). 

CAInCETIN  v.  Glucosides. 
CAINdN  V,  Glucosxdss. 
CXKrHGORM  V  QuABTz. 
CAJEPUT  or  CAJUPUT  OIL  v.  Oils,  Essjek- 
hal. 

CAJEPUTOL  V.  Camphobs. 

*  CAL  '  V.  TusosTEir. 

CALABAR  BEAN  v.  Okdeal  bkan. 

CALABAR  FAT  v.  Phtsostiominb. 

CALABARINE,    CALABAROL,    v.   Obdfal 

BBAV. 

CALAFATITE.  A  double  sulphate  of  alumi- 
nium and  potash,  so  named  after  its  discoverer, 
Calafat.  Occurs  near  Almeria.  Contains  SO4 
34-77,  A1,0,  37-98,  K,0  9*64,  H,0  17-61, 
sp.gr.  2*76.    ( V.  Alubitb.  ) 

CALAMIIIE  (G'almet,  Ger.).  Under  this  name 
two  common  zinc  minerals — ^the  carbonate  {v. 
Smithsonite)  and  the  hydrous  silicate  (v. 
Hemimorphite)— are     frequently     much     con- 


fused. The  Latin  form  lapis  ealaminaris  is 
supposed  to  be  a  corruption  of  the  old  name 
eadmia  (rad/Ja)  used  for  zinc  ores  in  general. 
The  minerals  in  question  often  so  closely  resemble 
one  another  in  external  appearance  that  it  is 
only  possible  to  distinguiah  them  by  chemical 
tests;  and  it  was  not  until  1803  that  James 
Smithson  definitely  established  the  existence  of, 
the  two  distinct  species.  The  name  calamine 
was  then  applied  by  some  authors  to  the 
carbonate  (sparry  calamine),  and  by  other 
authors  to  the  hydrous  silicate  (electric  Cala- 
mine). In  1832  F.  S.  Beudant  proposed  the 
name  smithsonite  for  the  carbonate,  restricting 
the  name  calamine  to  the  hydrous  silicate; 
but  most  unfortunately  Brooke  and  Miller,  in 
1862,  reversed  these  designations.  Beudant 
has  been  followed  by  Dana  and  many  other 
mineralogists,  but  m  Enffluid  the  name  cala- 
mine is  unfortunately  stiff  much  in  use  for  the 
carbonate,  and  hemimorphite  (G.  A.  Kenngott, 
1863)  for  the  hydrous  silicate.  The  use  of  the 
latter  name  partly  clears  up  the  confusion,  since 
it  is  descriptive  of  the  veir  characteristic  hemi- 
morphio  aevelopment  of  the  ciystals.  The 
old  name  zinc-spar  is  also  descriptive  of  the 
carbonate.  L.  J.  S. 

CALAMUS.  The  Indian  variety  of  Acorua 
calamus  (Unn.) ;  is  used  as  a  medicine  in  the 
Levant ;  the  Tnrlu  candy  it  and  employ  it  as 
a  remedy  against  contagion.  The  volatile  oil 
occasionally  enters  into  the  composition  of 
aromatic  vin^ar.  According  to  Thoms,  cicorin 
CggHf^Og,  in  contact  with  ferments,  splits  up 
into  sugar  and  oil  of  calamus 

Cs.HfoOg = C«H,  |0« +3CioHi« 
(cf,  von  Soden  and  Rojahn,  Chem.  Zentr.  1901, 
L  843 ;  Thoms  and  Beckstroero,  Ber.  1901,  34, 

1021 )  {V,  AOOBUS  OALAMUS). 

CALAVERITE,  A  telluride  of  gold,  AuTe., 
containing  40-43  p.o.  of  gold  with  1-3  p.c.  of 
silver.  It  was  first  found  in  Calaveras  Co., 
California,  and  afterwards  in  considerable 
abundance  in  the  Cripple  Creek  district  in 
Colorado  and  at  Kalgoorlie  in  Western  Aostnlia, 
where  it  is  of  importance  as  a  telluride  ore  of 
gold.  Sp.gr.  9-166-0*39.  The  small  complex 
(monoclinic  or  tridinic)  crystals  from  Colorado  are 
tin- white  in  colour,  tarnishing  to  bronze-yellow  on 
exposure.  The  massive  material  from  Kakoorlie 
is  pale  bronze-veUow  with  bright  metallic  histre ; 
and  with  its  suo-conchoidal  fracture  and  absence 
of  cleavage  it  much  resembles  iron-pyrites  in 
appearance— in  fact,  before  its  value  was  recog- 
nised, the  mineral  had  been  thrown  away  on  the 
waste  heaps  of  the  mines.  L.  J.  S. 

CALCIDINE.    Calcium  iodide. 

CALdNOL.    Calcium  iodate. 

CALCUE  09  CALC-SPAR.  One  of  the 
dimorphous  crystallised  forms  of  calcium  car- 
bonate (CaCOt).  This  rhombohedral  form  is 
less  dense  (sp.gr.  2*72)  and  lees  hard  (H.  3)  than 
the  orthorhombio  form  aragonite  (g.v.).  It  is 
also  the  more  stable  form :  when  aragonite  is 
heated  to  low  redness  it  passes  into  calcite^  and 
paramorphs  of  cakite  aftev  aragonite  are  of 
frequent  occurrence  in  nature.  From  an 
aqueous  solution  containing  carbon  dioxide, 
calcium  carbonate  crystallises  as  oaloite  at 
temperatures  of  0*-18^  and  as  a  mixture  of 
calclte  and  aragonite  at  higher  temperatures: 
the  presence  of  various  salts  in  the  solution  also 


730 


CAL01T£  OR  GALGSPAR. 


favoun  the  formation  of  aragonite.  (For  a  | 
summary  ot  the  literature  on  tnd  crystallisation 
of  calcium  carbonate,  see  F.  Vetter,  Zeitach. 
Kryst.  1910,  xlviii.  46.)  CSalcite  may  be  readily 
distinguished  from  aragonite  by  the  possession 
of  three  perfect  cleavages  parallel  to  the  faces  of 
the  primal  y  rhomboh^ron,  the  angles  between 
whidi  are  74''  66'  and  lOS""  5'  (the  plane  angles 
on  the  rhomb-shaped  faces  are  78^  and  IC^). 
The  mineral  is  readOy  scratched  with  a  knife, 
and  it  effervesces  briskly  in  coAtaot  with  cold 
dilute  acids. 

With  the  exception  of  quarts;  calcite  is  the 
commonest  of  nunerals.  It  frequently  occurs 
well  crystallised  and  in  a  great  variety  of  forms, 
the  various  forms  of  its  crystals  snsgesting  the 
trivial  names  *  dog-tooth-spar,'  *  nail-head-spar,' 
*  paper-spar,'  '  cannon-spar,'  &o.  As  the  essen- 
tial constituent  of  the  rocks  limestone,  marble, 
and  chalk,  it  is  of  abundant  occurrence.  In 
these  forms  it  finds  extensive  applications  as 
.building  and  ornamental  stones,  and  in  the 
manufMture  of  lime,  mortar,  and  cement.  The 
clear,  transparent  variety,  known  as  Iceland- 
spar  or  doublv-refracting  spar,  is  used  in  the 
construction  of  nicol  prisms  tor  optical  polarising 
appa>ratu&  Material  suitable  for  this  purpose  is 
oDtained  almost  exdusivelv  from  a  quarry  in 
basalt  on  the  Reydar-fiordnr  on  the  east  coast 
of  Iceland,  but  the  supply  n  limited  and  variable. 

A  considerable  quantity  of  dear  material 
suitable  for  optical  work  has  been  found  (1918) 
between  Greycliff  and  Bigtimber  in  Montana, 
where  it  occurs  in  vertical  veins  in  gneiss. 

JM   J.   S. 

CALCIUM.  Symbol  Gbt.  At.  wt.  40*0. 
Lime,  the  oxide  of  calcium,  has  been  employed 
in  the  preparation  of  mortar  from  very  early 
times.  Interesting  accounts  of  the  process  of 
lime-burning  are  given  by  Dioscorides  and 
Pliny.  It  was  not,  however,  until  1766  that  the 
difference  between  burnt  and  unbumt  lime  was 
explained  by  Black. 

Calcium  is  universally  found  as  carbonate 
GaCO,  in  the  forms  of  calcspar,  marble,  and 
limestone,  often  in  whole  mountain  ranges  or 
immense  ooral  reefs.  DclomiU  ov  biUer  spar, 
the  double  carbonate  of  calcium  and  magnesium, 
oonstitutes  the  geologica]  formation  termed  mag- 
nesian  limestone.  Calcium  sulphate  as  anhy- 
driU  CaS04  or  seieniie  {gypsum)  CaSO«-f  2HsO, 
is  also  very  plentiful  Tne  phosphate  united 
with  the  cmoride  or  fluoride  also  occurs  widely 
distributed,  often  as  minute  inclosures  in  crystals 
of  the  primary  rocks,  as  the  mineral  apaUte, 
whilst  calcium  is  an  impocbant  base  in  the  greater 
number  of  natural  silicates.  The  soluble  matter 
carried  away  by  rivers  largely  consists  of  the 
carbonate  and  sulphate  of  oaloium,  while  sea- 
water  contains,  in  addition  to  these,  both  phos- 
phate and  fluoride  of  calcium.  The  bones  of 
animals  consist  largely  of  ccdcium  phosphate, 
and  the  sheUs  of  molluscs  6t  the  carbonate. 
Oalcium  salts  are  never  absent  from  plant 
tissues,  concentrating  mainly  in  the  leaves. 

Calcium  also  occurs  in  extra-terrestrial 
bodies,  in  the  son,  meteorites,  and  many  fixed 
stars. 

Preparation  of  the  metal, — Calcium  was  ob- 
tained as  an  impure  metallic  powder  by  Davy  in 
1808,  by  the  electrolysis  of  the  ohioride,  using 
meroury  as  negative  electrode,  and  afterwards 
heating  the  amalgam  thus  formed  until  the 


mercury  was  volatilised.  It  was  obtained  as  a 
metallic  solid  by  Matthiessen  in  1856  (Chem* 
Soc.  Trans.  8,  28),  by  electrolysing  a  fused  mix- 
ture of  calcium  and  strontium  chlorides  in  the 
proportion  of  two  molecules  to  one  with  a  little 
ammonium  chloride,  the  whole  being  contained 
in  a 'porcelain  crucible.  On  passing  the  current, 
beads  of  metallic  calcium  separated  at  the 
negative  pole  and  were  ladled  out.  Moissan 
(Ann.  Chim.  Phys.  [71  18,  289)  repeated  the 
experiment,  increasing  the  size  of  the  apparatus, 
and  obtained  a  metol  possessing  a  yellowish 
colour. 

Lies-Bodart  and  Gobin  (Compt.  rend.  47,  23) 
obtained  calcium  by  heating;  the  iodide  with  an 
equivalent  of  sodium  in  an  iron  crucible,  the  lid 
of  which  was  screwed  down.  Moissan  repeated 
the  experiment  several  times,  and  states  that  the 
yield  and  purity  vary  greatly,  the  richest  metal 
obtained  containing  from  83  p.o.  to  93  puc. 
caloiuuL  The  reaction  proceeds  best  at  a  dull 
red  heat,  and  is  reversible  if  afterwards  the 
temperature  is  raised  to  whiteness. 

Frei  obtained  oalcium  in  globules  weighing 
2*4  to  4  fframs  by  the  electrolysis  of  the  chloride. 

Ano&er  process  consists  in  fusing  8  parts 
of  oalcium  cmoride  with  4  parta  ol  zino  and 
1  part  of  sodium,  thus  forming  an  alloy  ol  zino 
and  calcium,  which,  when  heated  in  a  gas-carbon 
crucible,  decomposes,  the  zinc  volatilising  and 
a  button  of  fused  calcium  remaining  (Caron« 
Annalen,  116,  366). 

Moissan  obtained  the  alloy  with  facility,  but 
was  unable  to  separate  the  csJcium  from  it. 

Moissan  ({.e.)  points  out  that  in  all  the  above 
metiiods  the  difficulty  is  to  free  the  calcium  from 
the  metal  with  which  it  has  become  associated 
in  the  preparation.  He>  however,  finally  suc- 
ceeded m  obtaining  the  pure  metal  by  utiliaing 
the  property,  unknown  bef  we  his  researches,  of 
molten  sodium  to  dissolve  oalcium.  For  the 
preparation,  he  adopted  a  modification  ol  the 
method  of  Lies-Bodart  and  Qobin.  In  an  iron 
crucible  of  about  1  litre  capaoity  ha  placed  a 
mixture  of  600  grains  of  coarsely  crushed  anhy- 
drous calcium  iodide*  with  240  grams  of  sodium 
in  pieces  as  large  as  nuts.  Tne  crucible  was 
closed  with  a  screw  lid  and  maintained  f ok  I  hour 
at  a  dull-red  heat,  then  allowed  to  cooL  The 
calcium,  which  is  soluble  in  excess  of  sodium  at  a 
red  heat»  separates  at  the  point  of  solidification 
and  becomes  practically  insoluble.  The  metallic 
portion  of  the  melt  is  cut  up  into  medium- 
sized  fragments  and  gradually  introduced  into 
absolute  aloohoL  The  sodium  dissolves,  leaving 
the  calcium  in  brilliant  white  crystals,  98*9  p.c. 
to  99'2  p.c.  pure. 

Buff  ana  Plato  have  succeeded  in  obtaining 
the  metal  in  relatively  laige  ouantities  by  the 
electrolysis  of  fused  calcium  chloride  by  keeping 
the  temperature  of  the  cathode  above  tho 
melting-point  of  calcium  (U.S.  Pat  806006). 
Borchers  and  Stockhem,  by  electrolysing  fused 
anhydrous  calcium  salts,  keeping  the  tempera- 
ture of  the  cathode  below  the  melting-point  of 
calcium,  obtained  the  metal  in  a  spongy  state 
( U.S.  Pat.  808066).  By  using  a  vertical  cathode, 
which  only  just  touches  Uie  surface  of  the 
fused  calcium  salt,  the  metal  is  deposited  on 
this  surface,  and  by  mechanically  nusing  the 
cathode  an  irroeularly  shaped  rod  of  cabium, 
resembling  a  oabbsge  stalk,  is  formed,  which 
itself  forms  the  oathode  (Eng.  I^t  90666 ;  ff. 


CALCIUM. 


731 


Johnson,  J.  Ind.  Eng.  Chem.  1910,  2,  466). 
The  eleotrolyte,  consisting  of  a  fused  mixture  of 
10  parts  of  CaClawith  17  parts  of  CaF^,  is  con- 
tained in  a  cylindrical  vessel  of  Acheeon  graphite. 
The  containing  vessel  forms  the  anode,  whilst 
the  cathode  is  an  iron  ribbon  which  can  be 
run  up  from  below.  The  best  deposits  were 
obtained  with  a  current  density  of  10  amperes 
per  square  cm.  If  the  cathode  current  density 
is  too  high  the  metal  does  not  adhere,  whilst  u 
the  anode  density  is  too  low  the  eletrolvte  is 
not  all  melted,  and  for  proper  control  the 
anode  and  cathode  surfaces  should  be  definite 
for  the  conditions  in  use.  Maldenhauer  and 
Andersen  (Zeitsch.  Elektrochem.  19,  144)  used 
a  mixture  of  85  p.c.  CaClg  with  15  p.c.  KCl 
and  a  current  density  of  60-110  amperes  per 
square  cm.  Rods  9^18  mm.  diameter  were 
obtained,  containing  Ca  96-09-9818,  K  0*0- 
014,  Fe  0-3-0-4,  Si  0-4O-O-70.  The  current 
yield  varied  from  65  to  over  90  p.c. 

Commercial  calcium  is  usually  coated  with 
CaClg,  which  can  be  partly  removed  by  absolute 
alcohol,  and  the  remainder  by  re-melting  in  an 
iron  bomb.  In  this  way  a  metal  containing 
99*44  p.c.  Ca  and  0*25  AIaO,+SiOt  ia  obtained. 

Calcium  is  made  commercially  at  Bitterfeld, 
Germany.  The  world's  production  is  about 
50  tons  a  year,  jwd  the  price  in  normal  times  is 
about  12^.  6d.  a  pound.  The  metal  melts  at 
810%  and  has  a  aensi^  of  1'548.  It  may  be 
turned  into  cylinders  Saving  a  brilliant  lustre 
*^Tnifthipg  in  air.  It  may  be  drawn  into  wire 
of  0*5  mm.  diameter.  Its  electric  conductivity 
is  16,  that  of  silver  being  100. 

Calcium  is  a  white  metal  approaching  silver 
in  colour. .  It  can  be  cut  with  a  Knife  or  oroken 
with  a  blow,  and  the  fracture  is  crystalline.  It 
scratches  lead,  but  not  calcite.  It  is  less  malle- 
able than  sodium  or  potassium.  The  crystals 
are  of  tabular  habit  and  belong  to  the  rhombo- 
hedral  system. 

GenUy  heated  in  air,  it  bums  with  incandes- 
oenoe,  or  if  heated  in  a  current  of  air  at  a  dull-red 
heat  it  leaves  a  spongy  mass  which  decomposes 
water,  producing  ammonia  and  calcium  hyorox- 
ide.  Calcium,  werefore,  fixes  both  nitrogen  and 
oxygen.  Calcium  inflames  when  heated  in 
oxygen  to  300^,  and  the  heat  is  so  great  that 
the  Time  formed  is  both  fused  and  pamy  volati- 
lised. Fluorine  gas  violently  attacks  calcium  at 
the  ordinanr  temperature.  Chlorine,  bromine, 
and  iodine  have  no  action  until  heated  to  400° 
or  above.  Metallic  calcium  exists  in  both  an 
active  and  an  inactive  form  in  its  power  of 
absorbing  ^ases.  Active  calcium  commences 
to  absorb  mtrogen  at  300®,  and  has  a  maximum 
action  at  440%  As  the  temperature  increases 
the  rate  of  combination  slowly  decreases,  until 
at  800®  it  has  ceased.  The  velocity  of  absorption 
is  dependent  on  the  presence  of  a  layer  of 
nitridb.  The  inactive  form  commences  to 
combine  with  nitrogen  at  800®.  The  difference 
is  not  due  to  the  existence  of  allotropes,  but  to 
the  state  of  sub-division.  The  active  variety  is 
porepared  by  slowly  cooling  mdten  calcium. 
This  variety  produces  a  black  nitride  (Zeitsch. 
Elektrochem.  22,  15).  Water  is  attacked  at 
the  oidinaxy  tempeFature  with  the  liberation 
of  hydrogen ;  tJie  action  is  slow,  owing  to  the 
formation  of  a  crust  of  calcium  hydroxide ;  the 
addition  of  sugar  hastens  the  action.  Fuming 
nitrio  add  attacks  it  only  slowly  if  free  from 


lime;  the  action  is  hastened  on  dilution. 
Fuming  sulphuric  acid  is  immediately  reduced 
in  the  cold  to  sulphur  and  sulphur  dioxide. 
Hydrochloric  and  acetic  adds  attack  caldum 
violently,  with  the  liberation  of  hydrogen.  At 
a  red  heat»  calcium  reduces  the  fluorides  and 
chlorides  of  potassium  and  sodium,  setting 
free  the  alkali  metals ;  under  the  same  condi> 
tions,  the  iodides  are  not  attacked. 

Calcium,  although  soluble  in  molten  sodium, 
from  which  it  separates  in  the  ciystalline  state 
on  solidification  of  the  solvent,  is  not  notably 
soluble  in  potassium.  The  only  definite  com- 
pound witn  mercury  appears  to  be  CaHg4, 
m.p.  266®  (decomp.).  With  magnedum,  it 
furnishes  an  alloy  which  decomposes  cold  water. 
The  freezing-point  curve  has  a  dmple  form,  the 
single  compound  Ca,MflN.  being  indicated  by  a 
maximum  at  715®,  whilst  there  are  eutectic 
points  at  514®  and  446®  and  18*7  and  78*7  p.c. 
of  Ca  respectively.  The  compound  Ca^Mg^  is 
brittle,  silvery  in  appearance,  stable  in  air,  and 
is  9nly  slowly  acted  on  bv  water.  Lead  and 
calcium  react  together  violently  in  the  molten 
state;  the  freezing-point  curve  has  maxima 
at  649®  and  1105®,  corresponding  with  the  com- 
pounds CaPba  and  Ca^Pb  respecUvdy.  Another 
compound  CaPb  is  formed  at  950®.  All  the 
alloys  fall  to  a  black  powder  in  air.  Copper  and 
calcium  form  a  single  compound  CaCu^,  mdting 
at  933®,  unstable  in  air.  Silver  ana  caldum 
form  a  complicated  system  of  alloys  (Zeitsch. 
Anorg.  Chem.  70,  352.  With  zinc  and  nickel 
it  forms  brittle  alloys.  Tin,  heated  just  abovd 
its  point  of  fusion,  combines  with  it  with 
incandescence,  forming  a  white  crystalline  alloy, 
containing  3*82  p.c.  calcium. 

Calelmn  hydride.  CaH,.  Caldum  does  not 
unite  with  hydrogen  at  the  oidinaiy  tempera- 
tures. To  prepare  it,  the  metal  cnt  into  small 
pieces  contained  in  several  nickel  boats,  is  placed 
in  a  glass  tube  sealed  at  one  end.  Hydn^a^  is 
fed  in  at  a  pressure  of  4  to  5  cms.  mercury,  the 
tube  being  neated  to  redness ;  the  temperature 
is  kept  sufficiently  low  to  prevent  union  between 
the  calcium  and  the  nickel  So  obtained,  it  is  a 
fused  white  solid ;  sp.gr.  1*7.  It  may  be  heated 
to  redness  in  air  without  chan^  Its  charac- 
teristic reaction  is  the  decomposition  of  water  in 
the  cold  with  the  liberation  of  hydrogen. 
Caldum  hydride  shows  a  marked  dissociation 
from  600®,  reaching  one  atmosphere  pressure 
below  800®.    This  cannot  be  a  true  dissodation 

Eressure,  as  the  hydride  is  readily  formed  by 
eating  calcium  in  hydrogen  at  830®.    A  second 
hydride  also  exists 

Ca-f  H-K;aH+23,100  caL  ; 

CaH+H->CaHa+22,000  oaL 

(Zdtsch.  Electrochem.  20,  81).  Bronsted  calcu- 
lates the  heat  of  formation  of  calcium  hydride 
from  solution  in  hydrochloric  add  :  for  CaH  from 
liquid  calcium  and  hydrogen  about  21,000,  and 
for  CaHg  firom  CaH  and  hydrogen  21,000. 
Gunts  and  Barrett  found  46,200  caL  from  solid 
caldum  (Zeitsch.  anorg.  Chem.  82,  130).  A 
mixture  of  BaS04  and  CaH,  ignited  by  a  fuse 
similar  to  that  used  in  thermite  react  vigorously 
according  to  the  equation : 

BaS04+CaH,»BaS+4CaO+4Ha 

(Ber.  46,  2264). 

Caleiam  oxide,     Lime.     CaO.     Anhydioui 


732  CA] 

oalcimn  oxide  (qnlcklmie)  it  obUiiMd  by  heating 
bo  redness  any  salt  of  "*!■''■■"'  oontoining  a 
Tolatile  acid,  aa  the  oarbonate  and  nitmle. 
Caloinm  carbooata,  vhen  heat«d  in  a  closed 
restel,  may  be  fined  without  deeonpositjon,  bat 
Then  laiaad  to  a  led  heat  unaer  ordiiiaiy 
preeaure  it  gives  off  iCa  carbon  dioxide,  and 
beoomea  converted  in  to  lime:  CaCO,=CaO-f  CO,, 

To  obtain  pore  lime,  Iceland  apar  oi  othsc 
forms  of  oaloite,  or  the  finest  nuuble,  may  be 
emploved,  the  ignition  being  performed  in  a 
cnioible  with  peiloroted  baoa  so  as  to  permit  of 
the  entraooe  of  fnmaoe  ga«e«,  which  carry  airay 
the  oarbon  dioxids  as  fast  as  it  it  formed  j  otfier- 
wise  the  dacompoeition  is  incomplete,  the  car- 
bonate undergoing  no  change  in  an  atmoaohere 
of  carbon  dioxide. 

Lime  is  made  by  healing  oaleium  oarbonate 
to  a  temperature  high  enough  to  drive  oS  the 
carbonic  aoid.  The  tensioa  ot  diasociation  of 
CaCD,  ia  27  nun.  at  S47'  and  753  mm.  at 
812*  i  in  practice,  the  temperature  for  boming 
lime  is  about  1000°.  The  raw  material  may  be 
nearly  pure  calcium  o^bonate  such  ^  marble 
or  chalk,  or  ma;  contain  so  much  elayey  matter 
that  the  product  is  a  cement  of  the  Portland  daaa 
rather  t^n  a  lime.  On  this  fact  choice  of  the 
mode  of  bDruing  in  part  depends,  because  if  the 
lime  is  needed  to  be  pure  it  must  be  burnt  out  of 
contact  with  solid  fi^l,  whereas  if  it  is  »  cement 
rather  than  a  lime,  the  addition  of  silicious 
matter  from  the  ash  of  the  fuel  may  be  actually 
an  advantage.  The  chief  usee  of  lime  are 
for  building,  in  agriculture  and  for  chemical 
manufacture.  For  the  first  purpose,  au  impure 
limestone,  burnt  in  contact  with  soUd  fuel,  is 
to  be  preferied,  whereoa  the  purest  obtainable 
limestinie.  heated  out  of  contact  with  fuel, 
yiehls  Ibe  beat  material  for  chemical  use.  In 
praotioe  ibsM  principles  ace  not  always  observed, 
partly  from  want  of  realisation  of  their  validity 
and  partly  because  it  is  sometimes  economical 
to  Modfioe  Uie  purity  of  the  produut  rather 
than  incut  the  expense  in  capital  and  fuel  of 
kilns  deeigned  to  bum  limeatone  out  of  contact 
with  solid  fuel,  but  tiie  knowledge  of  these  ia  of 
value  in  deciding  on  the  type  of  kiln  to  be 
adopted  in  any  given  ca^. 


bomt  under  an  oroh  made  of  the  material  to  be 
calcined,  thus  the  lime  produced  is  unocmtami- 
nated  with  ash.  So  crude  a  device  is,  of  course, 
not  economical  of  fuel,  but  its  simplicity  and 
cheapnese.  and  the  fact  that  it  can  produce 
exceUent  lime,  cause  it  to  be  still  used  to  a  cm. 
siderable  eit^t. 

Another  simple  form  is  the  common  runoing 
kUn  shown  in  Fig.  2.  .  The  limestone  or  ohalk 
is  loaded  into  the  kihl  with  alternate  layan 
of  small  coal  or  coke,  and  the  product  ii  btim 
time  to  time  drawn  from  an  eye  at  the  bottom 


FlO.  I. 
The  simplest  form  of  kihi  is  the  flare  kihi, 
shown  in  Fig.   I.     Tlia  fuel  (wood  or  psat)  is 


ol  the  kiln,  f reah  layers  of  raw  material  and  fuel 
being  added  throngh  the  charging  b^  at  the 
top  of  the  HIb.  Lime  made  m  kilii  of  this 
olaaa,  of  coarse,  contains  the  whole  of  the  ash  of 
the  fuel. 

A  more  elaborate  form  ot  tunning  kiln  It  the 
Oopeohogen  kiln,  ahown  in  Fig.  3.  It  u  ol 
the  oontmuous-thoft  type,  the  fnel  and  Umeetone 
bttaig  fed  in  at  the  t<^  and  the  lime  withdrawn 
at  the  b<4tam,  but  In  addition  a  definite  bntning 
son*  b  eetablkhed  by  feeding  a  portion  of  the 
fuel  In  at  the  side  openings  giving  into  the 
central  part  of  the  kiln.  The  heat  can  thus  be 
oontroUed  better  than  when  all  the  fuel  is  dla- 
ttibnted  through  the  whole  of  the  charge,  with 
the  result  tiiat  ooDsnmption  of  fuel  is  decreased. 

Another  shaft  kiln  is  the  Ryan  kiln,  need  in 
the  Buxton  district.  Ita  constmetion  ia  shown 
in  Fig.  4.  The  fuel  is  fed  in  at  the  udea  and 
the  Snestone  at  tbe^p,  so  that  the  ash  of  the 
former  la  leas  inextricably  mixed  with  the  burnt 
lime.  In  consequenoe  and  because  of  the  hard- 
ness fT"*  dense  structure  of  Buxton  limestone,  a 
large  part  of  tha  output  la  in  lump  praotkiaily 
onoontaminated  with  ash,  so  that  the  P«docJ 
can  be  picked  and  the  lump  of  lime  ot   high 


CALCIDH. 


733 


parify  (old  for  cbMtiioal  naa,  moh  m  tiw  muiu-  I  an  iot«nn«d(ate  ^p«  u  tlio  Rnmford  ItOn,  ihcnm 
iKtnn  ot  btoMhins  powder.  in  fig.  6. 

lime  emit  be  bnmt  tn  «  rotatorj  kUn,  nmilu 
to  diow  used  f m  oomMit  but  wockcd  «t  »  lower 
Iwnpciratiin,  but  few  nich  kflna  u«  fu  nao,  the 
probable  leuon  being  that  onlj  muU  lime  i 
would  be  prodneed,  kiid  for  m&ny  niea  lamp  lime  j 
iipreferrM. 


The  Ho8m*nn  kiln  (Fw.  S)  b  nted  to  pboe*  ', 
where  labour  i*  tofficient^  cbeai^  to  allow  of 
loading  and  nnloading  bj  hand  beug  performed 


3. — OOPKHHAOXH    KiLH, 


at  a  low  cost ;  it  has  the  advantage  of  being 
economical  of  fuel.  The  burning  chamber 
conaiata  of  an  endteaa  tunnel,  divided  into  com- 
partmente  of  approiimatetj  equal  size  by  means 
of  combustible  dampers.  Each  chamber  is 
provided  with  an  opening  in  the  outaide  wall 
for  charging  and  discluuging,  and  with  the 
main  flue  connecting  with  the  chimney.  The 
fuel  of  bleere  and  coal  is  introduced  through 
holes  in  the  arched  roof.  The  kiln  is  worked 
on  a  prt^ressive  scheine,  Fuel  being  ebargcd 
into  the  hottest  chamber,  and  air  beina  allowed 
to  enter  here  so  as  to  complete  the  calcination, 
while  the  gaaes  are  allowed  to  esca]ie  through 
dampen  in  the  last  chamber.  The  daily 
production       of      these      furnaces      is      very 

Passing  from  those  kilns,  like  all  the  torcgomg 
except  the  flare  kiln,  which  allow  at  least  some 
contact  of  the  ash  of  the  fuel  with  the  lime,  to 
gaa-Bred  kilns  in  whiob  contact  ii  whoUy  avoided. 


pass  to  the 
■haft  of  the 
kiln  and  over 
which  desoeiu]* 
the  Inimt  lime  t 

be  drawn. 

K 
kiln,  1 


I  openings  at  the  side,  where  it 


supply  of  secon- 
dary air,  heated 
by  passage 
through  the  hot 
lime  which  has 
deeoended  below 
the  level  of  the 
gas  inlets.  Kilns 
of  this  class 
have  the  ad  van- 
tages  that  they 
are  continuoua 
in  operation, 
need  but  little 
labour,  and 
allow  the  use  of 


the: 


Fw,  6, 


Commercial  lime  ranges  in  oompositioii  from 
almost  chemically  pure  calcium  oxide  to  a 
inat«rial  closely  resembling  Portland  oement. 
The  following  analyses  illustrate  tluB»~ 


WaMr  (E.O} . 
AUutllu  ^d  km 


}l>-71 


!P 


{l4-4T 


I  peewMfy.  >   moderately  riliOHniB  lime,  whleji 

e     will  wt  lightly  -per  »t,  la  pnferatda  to  tbe  flA 

S J     lime   aommomy   employpd.     In   ttii*   eonatry. 

Ea       I  lime  ii  almost  almya  ilaked  on  the  epot  and  at 

\  the  time  where  it  ia  to  be  need.     Abroad,  the 

VW  lime  is  usually  slaked  long  before  it  ia  uaed.  aod 
iit'TO  ^  '''""'  ^'°"'™  ^  become  completely  hydntod. 
j|.g4  The  cMiest  plan  is  to  make  a  p>M«  of  Ume  aad 
SS-43  I  water  (lime  putty],  and  keep  it  in  a  pit  nntil  it 
^;^*  I  is  needed.  In  like  manner,  dightly  hydiaulio 
gig^  lime  is  slaked  with  a  limited  qoantity  of  water 
£-eD  and  allowed  to  remain  in  siloa  nntil  the  Ume 
I'lS  itaeU  i»  completely  hydratad,  whilst  the  cementi- 
~7~.  tions  silicatee  remain  unaffected  and  ready  to 
act  as  cement  when  the  lime  is  put  to  aw. 

When   a   dolomitic   limestone   is   buint,    it 
yields   a   ILme   of   whfoh   the   foDowing   is   an 


.  , 


Insolnble  silicioDB  matter 
Alnmlna-t-terrio  oxide  (Al,0)+Fe|0|] 
Lime  (CaO) 


2-91 
1-00 
46-72 
32-60 
0-92 
3-27 
11-6B 


100-00 
Lime  of  this  kiod  needs  nAirb  care  in  slaking, 
ae  the  hydration  ot  the  magiiesia  takes  place 
■lowly  and  may  ocout  aft«r  the  mortar  ia  in  place, 
and  by  Gzpanaion  cause  destruction  of  the  work- 
AlthoDgh  lime  will  not  act  on  sand  at  the 
ordtHsry  temperatura,  yet,  like  other  alkaline 
bodies   it   attacks   H   readily   at   a    moderate 


FBI.  7. 


pnra  Tarieties  which  approach  the  natnn  of 
cement,  are  generally  preferable  for  bnildina. 
In  the  case  of  limes  containing  so  much 
silica  as  does  Chauz  de  Teil  and  so  much 
silica  and  alumina  as  does  Bine  Lisa  lime, 
they  mav  be  re^rded  aa  hydranlic  cements 
rather  tnan  limes  proper.  A  rongh  trade 
distinction  exists  between  '  fat '  and  '  poor ' 
time.  The  former  is  fairly  pore  and  dakea 
rapidly  and  with  a  high  rise  of  temperature ; 
the  latter,  contaiatng  some  combined  silica 
and  alumina,  slakes  slowly  and  relatively  feebly. 
Both,  when  mixed  with  eand,  form  mortars, 
but  fat  lime  sets  only  by  drying  aod  sab- 
sequent  absorption  of  carbouic  acid  from 
the  air,  whereas  the  lilicioua  constituents  in 
poor  liine  wiU  themselrea  set,  to  some  smalJ 
extent,  in  the  manner  of  a  cement.  Pure  lime, 
mixed  with  pure  q  narti  sand,  lias  no  appisotable 
action  on  it  at  the  ordinary  temperature,  but 
may  act  in  slight  d^ree  on  the  more  attackable 
silicious  concomitants  of  common  building  sand ; 
in  anj,  case,  however,  the  action  is  trifling,  and 
"•0  setting  of  common  mortar    b   practicaUy 


bricks 

'sand,  mixed  with  S-IO  p.c.  of  lime  just  hard 
I  enough  to  stick  together,  are  exposed  to  steam 
j  at  alMut  160° ;  at  that  temperature  the  lime  acta 
on  the  sand,  producing  calcium  silioatee,  which 
I  are  cementitious,  and  suffice  to  cement  the  sand 
I  grains  together  into  a  brick  of  ample  strength  for 
ordinary  building  pnrposes.  In  places  when  sand 
is  abundant  and  clay  snitable  for  briok  making 
ia  soaroe,  the  proceos  is  of  considerable  nee. 

Pure  calcium  oxide  forms  white  poroos 
amorphous  masses  of  s^.gr.  S-3  to  3-08,  highly 
infusible,  melting  only  in  the  highest  tempera- 
ture of  the  oxyhydrogen  blowpipe  flame  or  in  the 
eleotric  aro.  In  the  ordinary  ox^hydrogen  flame 
it  emits  an  intense  light,  wuch  u  mneh  aaed  lot 
lantern  projection. 

Calcium  oxide  has  been  obtained  by  BrOgel- 
mann  in  minute  cubic  crystals  of  sp.gr.  3-2S1 
by  heating  the  nitrate  in  a  porcelain  fladi  (Pogg. 
Ann.  [2]  S,  469  ;  and  [2]  4,  277). 

A  crystalline  mass,  found  upon  the  lining  of 
a  continuous  limekiln  at  Champigny  after  28 
months'  continuous  work,  was  alsoahowntocon- 
aistofamallcubical  crystals  of  pore  lime,  of  sp.gr. 
3'32iLevalloisandMeunier,Compt.rend.90, 1666). 
There  is  evidence  ot  the  existence  of  two 
forma  of  calcium  oxide.  The  oxide  otitained 
by  heating  caldte  at  a  low  red  heat  is  fine 
grained  and  porous.  When  heated  at  higher 
temperatures  the  refractive  index  ineroaaes  and 
cubic  cnatalline  calcium  oxide  ia  formed  for 
which  Nb=|-S3.  The  melting-point  of  CaO  aa 
determined  by  the  Holbom  Kurlbanm  optical 
pyrometer  is  2(iT0°  (J.  Washington  Acad.  Sci. 
133,  315}. 

Amorphous  Ume  takes  np   water  with  ra- 


CALCIUM. 


736 


markable  avidily,  formJiig  oaloinm  hydroxide 
Ca(OH),,  the  oombination  being  acoompanied 
by  a  contraction  in  volume  and  evolution  of 
heat  Owing  to  thiB  property,  it  is  used  exten- 
sively in  the  laboratory  and  works  as  a  drying 
agent.  On  exposure  to  air,  the  amorphous 
variety  of  lime  rapidly  absorbs  water  and  carbon 
dioxide ;  anhydrous  time,  however,  only  absorbs 
the -gas  when  heated  to  near  41 6^  Compara- 
tive tests  show  that  .carbon  dioxide  penetrates 
to  a  depth  of  about  3  inches  in  20  days.  More 
water  is  taken  up  in  summer  than  in  winter, 
but  the  carbon  dioxide  absorption  is  abont  the 
same  (Whetzel,  J.  Lad.  Eng.  Chem.  1917,  7. 
287)  lime  is  readily  soluble  in  dilute  mineral 
acids.  It  also  reacts  with  ethyl  alcohol  when 
heated  in  a  sealed  tube  to  115*  to  125*,  giving  a 
mixture  of  hydrate  and  ethylate  of  calcium. 

Caleliim  hydroxide,  or  Hydrate  ot  lime, 
Ga(OH),,  is  obtained  by  sUking  fresh  well- 
burnt  quicklime  with  about  a  third  of  its  weight 
of  water.  It  forms  a  white  amorphous  powder  of 
sp.ft.  2*078,  sparingly  soluble  in  water,  and  less 
so  m  hot  than  in  cold  water,  as  seen  from  the 
following  table  (Maben,  Pharm.  J.  [3]  14, 505) :— 


Parts  of  wster 

Parts  of  water 

Tempera- 

required  to 

Tempera- 

required to 

tare 

diitolve  one 

ture 

dissolve  one 

• 

partCaO 

partCaO 

0» 

769 

55* 

1104 

5* 

764 

60* 

1136 

10* 

770 

65* 

1208 

16* 

779 

70* 

1236 

20* 

791 

76* 

1313 

26* 

831 

80* 

1362 

30* 

862 

86* 

1388 

36* 

909 

90* 

1679 

40* 

932 

96* 

1650 

45* 

985 

99* 

1650 

50* 

1019 

According  to  Lamy  (Compt.  rend.  86,  333), 
the  solubility  varies  slightly  with  the  method  of 
preparation  of  the  hydroxide. 

The  solution  known  as  lime  water  has  an 
alkaline  reaction,  and  absorbs  the  carbon  dioxide 
of  the  atmorohere,  formins  a  pellicle  of  calcium 
carbonate.  Lime  water  of  definite  strength  for 
pharmaceutical  purposes,  is  best  prepared  by 
using  freshly  ignitea  lime.  In  preparing  lime 
water  from  ocdinary  lime,  the  first  solutions 
should  invariably  be  rejected,  as  they  will  contain 
nearly  all  the  soluble  salts  of  the  alkalis  and  the 
baryta  and  strontia  present  in  the  lime  as  im- 
purities. Milk  of  lime  is  an  emulsion  of  calcium 
hydroxide  suspended  in  less  water  than  is  required 
for  its  complete  solution.  Calcium  hydroxide  is 
much  more  soluble  in  solution  of  sugar  than  in 
pure  water,  due  to  the  formation  of  soluble 
saccharates  (for  solubilities,  v.  Weisberg,  BulL 
Soc  ohim.  21,  773). 

Calcium  hydroxide  is  precipitated  by  caustic 
potash  or  soda  from  strong  solutions  of  the 
chloride;  if  a  saturated  solution  of  calcium 
chloride  be  employed,  the  whole  becomes  solid. 

A  solution  evaporated  over  sulphuric  add  in 
a  vacuum  deposits  hexagonal  prisms,  accordins 
to  Qay-Lussao.  Crystals,  however,  which  haa 
separated  on  the  surface  of  samples  of  hydraulic 
cement  were  found  by  Glinka  to  belong  to  the 


rhombic  system  in  spite  of  their  hexagonal 
appearance.  A  deposit  of  grey  lAiinAllf[>^  con- 
sisting of  calcium  hydroxide,  was  found  by 
Luedecke  in  a  Carr6  ice  machine.  Selivanov 
(J.  Rubs.  Phys.  Chem.  Soc.  45,  252)  finds  that 
supersaturated  solutions  of  hydrated  calcium 
oxide  contain  0'260  to  0*264  gram  CaO  per  100 
c.c.  These  saturated  solutions  are  extremely 
sensitive  to  heat.  The  monohydrote  Ca(OH)| 
may  be  obtained  in  hexagonal  plates  by  heating 
the  solution.  The  cryohydrate  gives  on  solidi- 
fication transparent  ice,  but  the  solution  formed 
when  the  ice  melts  deposits  the  sesqui-hydrate 
2Ca(0H),,H gO  in  elongated  hexagonal  or  rhombic 
plates. «  The  compound  is  very  unstable. 

Calcium  hydroxide  is  an  energetic  base  com- 
bining with  acids  to  form  salts  and  displacing 
ammonia  from  its  compounds. 

At  a  red  heat,  calcium  hydroxide  is  decom- 
posed, water  being  driven  off  and  oxide  re- 
maining. 

Slaked  lime  is  used  extensively  in  the  pre- 
paration of  mortars  and  cements  {v.  Cements), 
for  softening  hard  waters,  in  the  preparation  of 
lyes  and  defecation  of  sugar,  and  for  agricultural 
purposes.  It  has  been  noted  that  as  regards 
the  application  of  lime  to  the  soil,  only  a  small 
proportion  reappears  as  carbonate,  the  remainder 
being  adsorbed  oy  the  soil  constituents. 

Calelom  dioxide  CaO,  was  first  prepared  by 
Thenard  by  the  action  of  excess  of  hydrogen 
peroxide  upon  Ume-water,  when  microscopic 
quadratic  plates  of  the  composition  Ca0t,8Ha0, 
sparingly  soluble  in  water  and  insoluble  in 
alcohol,  were  precipitated.  According  to  Conroy 
(Chem.  Soc.  Trans.  1873,  810),  the  peroxide  is 
most  conveniently  prepared  nby  adding  lime- 
water  in  considerable  excess  to  an  aqueous 
solution  of  sodium  peroxide  acidulated  with 
nitric  acid.  It  is  also  obtained  as  a  finely 
divided  white  precipitate  on  adding  a  neutral  or 
alkaline  solution  of  sodium  peroxide  to  a  solu- 
tion of  a  calcium  salt.  The  crystals  are  iso- 
morphous  with  those  of  hydrated  barium  per- 
oxide. On  exposure  to  air  they  effloresce,  and 
when  heated  to  130*  are  converted  into  the 
anhydrous  peroxide.  On  increasing  the  heat, 
half  the  oxygen  is  driven  off,  leavins  a  residue 
of  pure  lime.  CaO^  in  the  anhyobrous  form 
(Riesenfeld  and  Nottebohm,  Zeitsch.  anorg. 
Chem.  89, 405)  separates  from  very  concentrated 
solutions  near  0*,  and  above  40*  even  from  very 
dilute  solutions.  The  ootiUiydrate  is  obtained 
from  very  dilute  solutions  at  the  ordinary 
temperature.  The  octi^ydrate  is  dehydrated 
at  100*.  There  ia  no  appreciable  decomposition 
below  200*.  Up  to  273^  decomposition  is  slow, 
but  then  becomes  very  rapid.  Finely  divided 
CaOt  decomposes  explosively  when  heated 
rapidly  to  275*.  The  dissociation  pressure  at 
255*  is  more  than  190  atmospheiea. 

Caletum  eUorUe  OaCa,  is  found  in  the 
water  of  nearly  all  springs  and  rivers,  and  is 
consequently  a  constituent  of  the  saline  matter 
dissolved  in  sea* water.  This  salt  also  forms  the 
chief  saline  constituent  of  an  exudation  oc- 
curring on  the  faoe  of  the  old  red  sandstone 
rooks  at  Quy's  Cliff,  in  Warwickshire,  occurring 
to  the  extent  of  27*15  p.o.  (Spiller,  Chem.  Soc. 
Trans.  1876,  1,  154).  (Salcium  chloride  likewise 
occurs,  together  with  magnesium  chloride  and 
alkaline  chlorides  in  the  Utckydriti  and  camaUUe 


73d 


CALCIUM. 


of  the  Staasfurt  deposits,  iachydriU  containing 
21  p.e.  CaCl,  and  30  p.0.  MgCl,,  while  eamaUite 
contains  3  p.c.  CaClt,  and  31  p.c.  Msd^ 

Caloium  chloride  may  be  ootainea  by  passing 
chlorine  over  the  red-hot  oxide,  or  by  dissolvine 
lime,  chalk,  or  marble  in  hydroclilorio  acid  and 
evaporating.  If  it  is  neoessanr  to  obtain  the 
salt  pore,  chlorine  water  may  be  added  to  the 
solution  in  hydrochloric  acid  in  order  to  oxidise 
any  iron  nresent,  which  may  then  be  precipitated 
by  the  addition  of  milk  of  lime,  and  filtered  off. 
llie  slightly  alkaline  filtrate  is  then  acidified 
with  hydrochloric  add  and  evaporated  to  the 
orystalusing  point* 

Calcium  chloride  is  obtained  in  laiffa  quan- 
tities as  a  by-product  in  many  manuutcturing 
processes,  notaolv  in  the  preparation  of  potas- 
sium chlorate  ana  in  the  manufacture  of  sodium 
carbonate  by  the  ammonia-soda  process ;  it  may 
be  obtained  in  the  pure  state  from  these  crude 
products  by  the  method  just  indicated.  Many 
attempts  liave  been  made  to  utilise  this  waste 
calcium  chloride.  Richardson  (B.  P.  10418) 
treats  the  purified  crude  solution  with  am- 
monium sulphate  in  the  proportion  required  to 
convert  all  the  chloride  into  sulphate;  the 
calcium  sulphate  could  then  be  filtered  off,  and 
ammonium  chloride  recovered  by  crystallisation. 
Pelouze  (Compt.  rend.  62,  1267)  was  the  first  to 
point  out  that  calcium  chloride  mixed  with  sand 
to  prevent  fusion  is  almost  completely  decom- 
posed when  heated  to  redness  and  treated  with 
9team,  the  chlorine  being  evolved  as  hydro- 
chloric acid.  The  process  was  patented  by 
Solvay,  and  the  metnod  applied  to  the  waste 
calcium  chloride  liquors,  out  the  condensed 
hydrochloric  acia  obtained  is  dilute  and  does  not 

Eay  for  the  coal  consumed  in  the  operation, 
runge  considers  that  so  long  as  hydrochlorio  acid 
is  so  cheap,  no  possible  method  can  be  found  to 
utilise  the  dilorme  in  the  waste  liquors  at  a  profits 
Saturated  ilblutions  of  calcium  chloriae  de- 
posit the  hydrated  salt  in  laige  hexagonal  prisms 
terminated  by  pyramids,  ot  the  composition 
CaCla,6H,0.  The  crystals  melt  at  29*  in 
their  water  of  crystallisation  and  deliquesce 
rapidly  in  the  air,  forming  a  viscous  fluid, 
formerly  termed  oleum  cal^.  Heated  bdow 
200®,  or  in  a  vacuum  over  sulphuric  acid,  the 
crystals  lose  four  molecules  of  water.  The  re- 
maining two  molecules  can  only  be  expelled 
above  200"".  According  to  Weber  (Ber.  15, 
2316),  the  salt  dried  at  180'*-200<'  is  practicaUy 
anhvdrous,  containing  only  0*2  p.c.  of  water. 
Besides  the  two  hydrates  above  described, 
Lescoour  (Compt.  rend.  02,  1168),  from  deter- 
minations of  maximum  tensions  of  solutions, 
shows  the  probable  existence  of  two  others 
Caaa,4HtO  and  CaCla,H,0.  The  tetrahydrate, 
however,  can  only  exist  below  129**.  Milikitn 
(Zeitsch.  physikaL  Chem.  92,  496)  has  examined 
the  equilibrium  conditions  in  the  system 
CaCla-HCl-HaO.  The  solution  containing 
44*5  p.c.  CaClf  and  3'3  p.c.  HCl  is  in  equilibrium 
with  the  solid  phases  CaC]t,6H,OandCaClt,4H,0 
and  the  solution  containing  28*48  p.c.  CaCla 
and  21*40  p.c.  HCl  with  the  solid  phases  CaCI^, 
4H,0  and  Caa„2HaO. 

Anhydrous  calcium  chloride  is  a  white  porous 
mass,  which  fuses  at  a  red  heat  or,  accorcung  to 
liO  Chatelier  (Bull  Soc.  chim.  47,  300),  at  755^ 
On  cooling,  the  salt  solidifies  to  a  translucent 


mass  of  crystals  of  sp-gr.  2*206.  A  slight  de- 
composition into  oxide  and  carbonate  occurs 
when  the  fusion  is  performed  in  air.  On  this 
accoxmt,  the  porous  chloride  obtained  by  drying 
the  ciystali  at  260*"  is  better  adapted  for  desio- 
cating  purposes,  espedaUy  for  the  absorption  of 
water  in  organic  analysis.  HcPherson  {J.  Amer. 
Chem.  Soc.  1917,  39,  1317)  has  shown  that 
granular  calcium  chloride  when  absolutely  dry 
will  remove  every  trace  of  moisture  from  a  gas 
passed  over  a  sufficiently  long  colunm  of  it. 
If  the  fused  mass  is  exposed  to  the  sun*s  rays, 
it  becomes  phosphorescent  in  the  dark,  and  was 
formeriy  called  JSomberff^s  pho$pkonts,  after  tlie 
discoverer  of  the  lact  in  1603. 

Anhydnms  calcium  chloride  is  highly  de- 
liquescent. 100  parts  of  the  powder  exposed  to 
an  atmosphere  saturated  with  aqueous  vapour 
absorb  124  parts  of  water  in  96  days.  Accord- 
ing to  Kremers  (Pogg.  Ann.  103,  67  ;  104,  133  ; 
J.  1868,  40),  the  foUowing  quantities  of  water 
axe  required  to  dissolve  one  part  by  weight  of 
the  anhydrous  salt : — 

At  10-2*  20*  40*  60* 

1-68  1-36  0*83  0*72 

In  the  foUowing  table,  drawn  up  by  the  same 
author,  are  shown  the  specific  gravities  oi  solu* 
tions  of  varying  strengths  : — 

QuantitiM  in         8p.8r.  of  solaUoiis  at 
100  parte  wmfeer      19*6*'  (water  at  10*6?sl) 
6*97  1-0646 

12*68  10964 

23*33  11681 

36-33  1-2469 

60-67  1-3234 

62*90  1-3806 

According  to  Engel  (BulL  Sao.  chim.  47, 318), 
100  parts  of  water  at  0*  dissolve  60*3  parts  OaCls, 
Forming  a  solution  of  sp.gr.  1-367. 

A  solution  of  60  parts  anhydrous  Gad,  in 
100  parts  water,  boils  at  112*,  one  containing 
200  p.0.  boils  at  168*,  and  a  326  p.a  solution 
boils  at  180*. 

According  to  Lef ebvre  (Compt  rend.  70,  684) 
a  supersaturated  solution  of  calcium  chloride  is  * 
formed  by  dissolving  360-400  grams  of  the  orys* 
tallised  salt  in  60  c.c.  warm  water  or  200  grama 
of  the  anhydrous  salt  in  260  cc.  water ;  it  may  be 
shaken  alter  cooling  without  crystallisation,  but 
solidifies  on  contact  with  a  crystal  of  the  salt.  If 
oooled  to  6*8*,  this  solution  begins  to  crystallise, 
the  temperature  rising  to  28*-29*.  A  solution 
oontainng  66  p.a  CaC3|  deposits  at  about  16* 
lar;^  plates  of  the  tetrahydrate  CaGlt»4H,0, 
which  do  not  induce  the  crystalliBation  of  the 
supernatant  liquor.  This  solution,  in  passing 
from  liquid  to  solid  state,  undergoes  at  70^  a 
contraction  0*0832  of  its  volume. 

The  crystallised  chloride  CaCl„6H.O  also 
deliquesces  rapidly,  and  dissolves  in  naif  its 
weignt  of  water  at  0*,  in  one-fourth  its  weight 
at  16*,  and  in  all  proportions  of  hot  water.  In 
dissolving  it  absoros  heat,  while  the  anhydrous 
chloride  dissolves  with  evolution  of  heat.  A 
mixture  of  1*44  parts  ciystallised  chloride  with 
1  part  of  snow  produces  a  cold  of  —64-9*,  more 
than  sufficient  to  freeze  mercury. 

Both  the  anhydrous  and  hydrated  chloride 
dissolve  readily  in  alcohol,  10  parts  at  80*  dis- 
solving 6  parts  anhydrous  OaCA, ;  on  evaporation 
in  a  vacuum  at  winter  temperature,  rectangular 
plates  of  2Caas,7C,HcO  are  deposited. 


CALCIUM. 


737 


Anhydrous  calcium  chloride  absorbs  am- 
monia sas,  forming  the  compound  CaCl^tSNEa 
as  a  wnito  powder,  which,  on  exposure  to  air, 
solution  in  water,  or  on  heating,  is  decomposed. 
Thrown  into  chlorine  gas,  the  compound  takes 
fire.  Calcium  and  barium  chlorides  form  the 
double  salt  CaC],3aCla  (ra.p.  63V),  but  no 
mixed  crystals.  Calcium  and  strontium  chlor- 
ides form  a  continuous  series  of  mixed  c^stals 
with  a  minimum  meltinf-point  at  658*  and 
66  moL  p.o.  CaCL  (Jahr.  Min.  15). 

Calelnm  oxyenloride.  When  calcium  chlor- 
ide solution  is  boiled  with  slaked  lime,  and  the 
liquid  filtered,  white  needle-shaped  crystals 
of  calcium  oxychloride  separate  out  on  cooling 
of  the  composition  aCaO-Ca(OH),7HaO  or 
3CaO-Caat,15H,0  (Grimshaw,  Chem.  News*  30, 
280).  The  salt  is  stable  out  of  contact  with  air, 
loses  part  of  its  water  of  crystallisation  over 
sulphuric  acid  or  caustic  lime,  and  absorbs 
oaroon  dioxide  from  the  atmosphere.  It  is 
decomposed  by  water  or  alcohoL 

According  to  Andr€  (Compt.  rend.  92, 
1452),  the  composition  of  the  salt  is 

Caa,-3Ca0.16H,0 
and,  on  drying  in  a  vacuum,  it  becomes  converted 
into  Caa,*3CaO,3H,0. 

When  calcium  chloride  is  fused  at  a  bright- 
red  heat  in  a  current  of  moist  air,  it  is  gradually 
converted  to  an  oxychloride  of  the  composition 
Cadi'CaO,  and  eventuaUy  to  oxide  (Gorgeu, 
Compt.  rend.  99,  266). 

Caleium  hypoehlorite  v,  BLXAOHnra  fowdib. 

Calelnm  chlorate  Ca(aO,)2  is  produced  when 
chlorine  is  passed  into  hot  milk  of  lime,  but 
is  difficult  to  separate  from  the  chloride  simul- 
taneously formed.  This  is  the  first  step  in  the 
manufacture  of  potassium  chlorate,  and  the  re- 
action is  supposed  to  be  as  follows : — 

6Ca(OH),-f6a,=Ca(C10,),.f5Caa,+6H,0. 

According  to  Lunge  (J.  Soo.  Chem.  Lidr  1885, 
722),  the  reaction  r^lv  takes  place  in  several 
stages,  calcium  hypochlorite  and  hypochlorous 
acid  beinff  first  formed  and  mutually  reacting 
with  promiction  of  calcium  chlorate  : 

(1)  Oa(001)s-l-4GU2HiO=Oa01.+4HC10. 

(2)  2Ca(OOr)i-i'4HC10=CaCla+Ca(C10,),-»4Cl'i-2H|0. 

The  free  chlorine  serves  only  as  carrier  of 
the  oxygen  of  two  molecules  calcium  hypochlor- 
ite to  a  third  molecule  of  the  hypochlorite  which 
is  oxidised  to  chlorate.  Lunge's  experiments 
show  that  the  best  mode  of  convertmg  hypo- 
chlorite into  chlorate  is  to  raise  the  temperature 
of  the  solution,  slight  excess  chlorine  beine  at 
the  same  time  present.  The  heat  raoducea  by 
the  reaction  on  the  large  scale  is  sufficient. 

Calcium  chlorate  can  best  be  prepared  by  the 
electrolysis  of  a  10  p.c.  solution  of  calcium  chlor- 
ide. The  density  of  the  current  should  be  10 
amperes  per  square  decimeter  at  the  anode  and 
double  at  the  cathode  ;  temperature  50°  (Zeitsch. 
Elektrochem.  4,  464). 

It  may  also  be  prepared  by  precipi- 
tating potassium  chlorate  with  calcium  silico- 
fluoride.  It  crystallises  in  deliquescent  rhom- 
boidal  plates,  very  soluble  in  water  and  alcohol ; 
the  crystals  contain  16*5  p.o.  water,  melt 
when  warmed,  and  decompose  on  further 
heating. 

'     Caleium  perehlorate  Ca(a04)|  may  be  ob- 
tained by  saturating  perchloric  acid  with  caustic 

Vol.  L— r. 


lime.    It  is  extremely  deUqnescent  and  crystal- 
lises in  prisms  soluble  in  alcohoL 

Calcium  bromide  CaBr^  (m.p.  730°)  is  formed 
b^  burning  calcium  in  bromine  vapour,  or  by 
dissolving  lime  or  calcium  carbonate  in  hydro- 
bromic  acid  and  evaporating.  The  silky 
needles  thus  obtained  are  hydrated,  but  may 
be  converted  to  the  anhydrous  salt  by  heating. 
Calcium  bromide  much  resembles  the  chloride 
in  properties,  beiiig  deliquescent,  and  very 
soluble  in  alcohoL  NaBr  and  CaBr,  solidify 
to  form  two  series  of  solid  solutions  with  a 
eutectio  point  at  513°,  and  on  further  cooling  a 
reaction  takes  place  at  469°,  a  compound 
NaBr,2Ca6r,  beins  formed.  KBr  forms  a 
single  compound  KBrCaBr,,  represented  by  a 
maximum  on  the  freezing-point  curve  at  637°. 
There  are  eutectio  pointe  at  544°  and  563° 
respectively  (Zeitech.  anorg.  Chem.  99,  137). 

Calcium  iodide  Cal^  may  also  be  prepared 
by  combustion  of  calcium  in  iodine  vapour,  or 
by  solution  of  lime  or  the  carbonate  in  hydriodio 
acid,  evaporating  and  fusing  the  residue  in  a 
closed  vesseL  Heated  in  contact  with  air,  it 
fusee  below  a  red  heat,  and  is  decomposed  with 
liberation  of  iodine  vapours  and  formation  of  lime. 

liebig  (Annalen,  121,  222)  recommends  de- 
composition of  Cal|  by  K^SOf  for  preparation  of 
iodiae  of  potassium.  To  prepare  the  calcium 
iodide,  1  oz.  of  amorphous  phosphorus  is  drenched 
\nUi  30  oz.  hot  water,  and  finely  pulverised  iodine 
gradually  added  with  constant  stirring  as  long  as 
it  dissolves  without  colour  (quantity  thus  dis- 
solved being  13(  oz.).  The  colourless  liquid  is 
then  decanted  from  the  slight  deposit,  and  made 
sliffhtly  alkaline  with  milk  of  lime  (8  oz.  lime 
bemg  required) ;  the  solution  is  afterwards 
strained,  and  residue  of  phosphate,  phosphite, 
and  hydrate  of  calcium  washed.  The  solution 
then  contains  the  calcium  iodide,  which  may,  if 
necessary,  be  obtained  by  evaporation  in  the 
form  of  hvdrate  in  deliquescent  needles. 

A  double  iodide  of  calcium  and  silver  of  the 
composition  CaI|'2AgI,6HgO  has  been  prepared 
by  Simpson  (Proc.  Roy.  Soc.  27, 120)  by  saturat- 
ing a  hot  concentrated  solution  of  Cal.  with  moist 
silver  iodide.  It  crystallises  on  cooling  in  long 
white  needles,  decomposed  by  water.  The  basic 
salto  formed  by  the  alkaline  earth  metal  haloids 
have  been  studied  by  the  equilibrium  relations 
in  the  ternary  system  between  the  haloids,  the 
corresponding  hydroxides  and  water.  The  basic 
salt  Cal,  3Ca046H,0  is  stable  at  25°  m  contact 
wiUi  solutions  containing  28 '44  p.c.  to  66-68  p.c. 
Cal.  (Zeitech.  physikaL  Chem.  1917,  92,  59). 

Calcium  iodato  Ca(IO,)a  is  obtained  by  crys- 
tellising  mixed  solutions  of  potassium  iodate 
and  ciJcium  chloride.  The  hydrated  salt  forms 
four-sided  prisms  which  effloresce  in  the  air,  and 
become  anhydrous  when  heated  to  200°.  From 
a  solution  acidulated  with  nitric  acid,  it  separates 
in  trimetric  crystols.  The  crystals  are  soluble 
in  454  i>arta  water  at  18°,  and  in  102  parte  of 
boiling;  water,  but  are  insoluble  in  alcohol.  The 
anhy£x>us  salt,  gently  heated  in  a  porcelain 
retort,  evolves  14^8  p.c.  of  oxygen,  ana  54-07  of 
iodine,  leaving  31*14  p.o.  of  a  residue  rich  in 
pentobaaic  perlodate  of  calcium.  Heated  more 
strongly,  it  evolves  more  oxygen  and  iodine,  and 
leaves  20*35  p.c.  of  a  mixture  of  pentobasic  per- 
lodate and  free  lime.  Calcium  iodate  detonates 
violently  when  heated  on  charcoal. 

3  B 


738 


CALCIUM. 


Sonstadt  proposes  (Eng.  Pat.  6304»  1884)  to 
nae  calcium  iodate  as  an  antiseptic. 

Perlodates  of  ealeium.  When  the  sodium 
salt  NaH^IO.  is  decomposed  by  calcium  ni- 
trate, a  crystalline  white  precipitate  of  dicalcium 
penodate  CaHJO,  or  2Ca0.3HaO.I,0,  is  ob- 
tained. When  this  salt  is  heated,  water, 
oxygen,  and  iodine  are  given  off  and  penta- 
calcium  periodate  Ca.I^^,  remains  (Lanfflois). 
Calcium  fluoride  CaF,  is  found  widefy  dis- 
tributed in  nature  and  is  Known  aa  fluor-spar.  It 
is  the  only  common  mineral  in  which  fluorine 
forms  one  of  the  principal  constituents.  It 
occurs  both  massive  and  in  beautiful  cryst4il9, 
generally  cubes  or  forms  in  combination  with 
the  cube.  It  is  a  comiQon  vein  mineral,  occur- 
ring usually  in  association  with  metallic  ores, 
baiytes,  calcite,  &c.  It  presents  a  variety  of 
colours,  sometimes  shading  into  one  another  as 
in  the  beautiful  *  Blue  John '  of  Derbyshire. 
All  the  coloured  specimens  lose  their  colour  on 
heating,  green  specimens  being  the  most  difficult 
to  decolourise  completely.  Thermo-lumines- 
cence  is  very  markea  in  all  naturally  coloured 
crystals,  a  violet  light  being  emitted  in  most 
cases,  with  decrepitation.  Free  fluorine  has 
been  shown  to  exist  in  a  dark  violet  fluor  spar 
from  Quinci^,  Dept.  du  Rhdne.  Crystallised 
colourless  fluor  spar  can  be  coloured  deep  blue 
by  the  fi-  and  7-rays  of  radium,  and  then  shows 
on  gentle  warming  a  beautiful  green  thermo- 
luminescence  which  fades  and  changes  into  the 
pale  violet  light  characteristic  of  all  fluor  spars. 
Debieme  found  that  certain  dark  violet  fluor 
n>ars  smell  of  ozone.  When  heated  they  lose 
their  colour  and  thermo-luminescence  and  also 
yield  helium  in  variable  but  small  quantity. 
On  exposure  to  radium  rays  the  violet  colour 
was  restored.  It  is  also  a  constituent  in  small 
quantities  of  many  plant  ashes,  of  bones,  and 
ci  the  enamel  of  teeth.  When  calcium  fluoride, 
obtained  by  precipitating  any  soluble  calcium 
salt  with  fluoride  of  sodium  or  potassium,  is 
heated  with  water  slightly  acidifled  with  hydro- 
chloric acid,  the  precipitate  is  found  to  consist 
of  mioroioopic  octahedrons. 

Calcium  fluoride  is  soluble  in  about  2000 
parts  of  water  at  16*,  and  is  slightly  more 
soluble  in  water  containing  carbon  oioxide.  It 
dissolves  ia  hydrofluoric  acid  and  in  strong  hydro- 
chloric acid,  and  is  precipitated  in  the  gdatinous 
form  by  ammonia.  It  is  fusible  at  902**,  and 
is  used  as  a  flux  in  many  metallurgical  opera- 
tions, especially  in  the  reduction  of  aluminium. 
It  is  decomposed  at  a  hiffh  temperature  bv 
water  vapour  into  lime  ana  hydrofluoric  acid. 
Fusion  with  alkaline  carbonates  or  hydroxides 
yields  carbonate  or  oxide  of  calcium  and  alkaline 
fluorides.  Strong  sulphuric  aoid»  on  gently 
warming,  decomposes  it,  forming  calcium  sul- 
phate and  liberating  hydrofluono  acid.  At  a 
red  heat  it  is  also  decomposed  bv  chlorine. 
After  being  heated  fluor  spar  phosphoresces  in 
the  dark.  There  is  a  consideraole  industry  car- 
ried on  in  fluor-spar  districts  in  the  carvlne  of 
ornamental  vases  and  other  articles,  the  bril- 
liantly coloured  varieties  being  especially  in 
demand. 

Oalelum  earbldo  CaC,.  Wdhler  (Ann.  Chim. 
Phys.  126,  120)  showed  that  by  the  action  of 
carbon  on  a  molten  alloy  of  zinc  and  calcium,  a 
black  mass  is  obtained,  which  on  contact  with 


cold  water  liberates  various  gases,  Winkler 
indicated  the  reduction  of  the  alkaline  earths  by 
magnesium  (6er.  22,  120).  Maquenne,  in  1892, 
prepared  caloiam  carbide  as  an  impure  amor- 
phous black  powder,  and  Travers  obtained  it  by 
heating  together  calcium  chloride,  sodium,  ana 
carbon.  It  was  not,  however,  until  the  adv«nt 
of  the  electric  furnace  that  it  became  possible  to 
manufacture  a  pure  carbide  suitable  for  the 
preparation  of  acetylene.  Hoissan  (Compt. 
rend.  138,  243)  used  a  mixture  of  lime  120  grams, 
sugar  carbon  70  grams,  which  was  heated  in  the 
crucible  of  an  dectric  furnace  for  20  minutee 
with  a  current  of  360  amperes  and  70  volts. 
At  the  temperature  of  liquefaction  of  the  lime, 
this  reaction  occurs:  CaO+3Cs=CaCt+CO. 
Pure  calcium  carbide  is  crystalline,  colourless, 
and  transparent,  but  the  commercial  variety, 
disoolourea  by  iiDn,  is  usually  brownish-red. 

Its  characteristic  reaction  is  the  decomposi- 
tion of  water  in  the  cold,  with  the  liberation  of 
acstvlene  and  the  formation  of  calcium  hydr- 
oxide (v.  Acetylene). 

One  of  the  most  interesting  developments  of 
the  manufacture  ia  the  production  of  nitrolin,* 
calcium  cyanamide  Ca(CN)t>  from  calcium  car- 
bide for  manurial  purposes.  The  nitrogen  re- 
quired is 'obtained  from  the  air  by  the  Lin(^ 
Company *s  plant,  which  produces  bioth  nitrogen 
and  oxygen.  The  union  of  powdered  calcium 
and  nitrogen  takes  place  with  the  evolution  of 
heat,  hence  the  temperature  has  to  be  maintained 
between  800''-1000^,  as  at  higher  temperatures 
the  calcium  cyanamide  decomposes.  The  ab- 
sorption occupies  30  to  40  hours,  and  the  product 
is  a  cokelike  material  which  is  ground  to  powder 
before  being  placed  on  the  market  {v,  NiTBOom, 
UHLISATIOir  OF  atmosfhebio). 

Calcium  Gaibide,  Manulactnie  of.  The  com- 
mercial manufacture  of  calcium  carbide  ia 
credited  to  WiUson  in  America  and  Hdroult  in 
Europe.  It  was  started  in  the  early  eighties  of 
last  centuiT,  and  by  progressive  devdopment 
acquired  the  distinction  of  being  the  largest 
consumer  of  energy  in  the  electric  furnace 
industry.  This  continued  extension  resulted  in 
a  better  design  and  increased  size  of  furnace, 
together  with  the  necesssiy  equipment  for 
handling  laige  quantities  of  raw  materials  and 
for  preparing  the  carbide  for  the  market. 

The  chieffactors  which  have  to  be  considered 
in  the  choice  of  a  site  for  a  carbide  factory  are 
supplies  of  raw  material  consisting  of  limestone 
and  coke,  or  anthracite,  and  an  abundant  source 
of  cheap  electric  power.  Large  works  have 
consequently  been  established  in  places  where 
a  practicsUy  unlimited  supply  of  water  power  is 
available.  Hence,  most  progress  in  the  industiy 
has  been  witnessed  in  Norway,  where — excepting 
coal — other  demands  are  amply  satisfied. 

The  raw  materials  used  in  the  manufacture 
of  calcium  carbide  should  be  as  pure  as  possible. 
Special  attention  should  be  paid  to  obtaining 
them  free  from  phoq[>horus,  sulphur,  ana 
magnesia;   silica,  iron,  and  alumina  should  be 

5 resent  only  in  small  quantities  (t;.  Witherspon, 
.  Soc.  Chem.  Ind.  1913,  113). 
Phosphorus  occurs  in  limestone  as  calcium 
phosphate,  and  is  reduced  at  the  temperature  of 
the  tumace,  and  iii  the  presence  of  carbon,  to 
calcium  phosphide,  which,  when  brought  into 
contact    with    water,    evolves    phosphoretted 


I 

I 

I 


CALCIUM. 


739 


hydroeeiL  This  gas  mixes  with  the  acetylene, 
and  when  the  burners  are  lighted,  causes  a  haze 
of  phosphorus  pentozide,  which  is  very  objec- 
tionable. So  carefully,  however,  are  the  raw 
materials  selected  that  all  commercial  carbides 
are  practically  free  from  phosphorus,  the  average 
content  in  acetylene  bemg  less  tluui  0*002  p.c. 
by  volume.  (For  a  method  of  examining  com- 
mercial carbide  for  calcium  phosphide  based  on 
that  of  Lunge  and  Cedercreutz,  sec  Dennis  and 
O'Brien,  J.  Ind.  Eng.  Chem.  1912,  4,  834.) 

Sulphur,  unless  present  with  considerable 
amounts  of  alumina,  has  little  influence  on  the  re- 
sulting carbide.  Calcium  sulphide,  formed  in  the 
furnace  by  the  reduction  of  calcium  sulphate,  does 
not  decompose  in  the  production  of  acetylene, 
but  in  the  presence  of  alumina,  aluminium  sul- 
phide may  be  formed,  which  yields  hydrogen 
sulphide  when  brought  in  contact  with  water. 
Very  little  trouble,  however,  is  experienced  with 
sulphur,  as  the  lime  and  coal  used  in  the  manu- 
facture rarely  contain  a  prohibitive  quantity. 

Magnesia  has  the  peculiar  property  of 
interfering  with  the  formation  of  calcium  carbide 
in  the  furnace.  If  more  than  one  p.c.  of  magnesia 
be  present  in  the  lime  and  coal,  the  electrical 
eneigy  reauired  becomes  noticeably  so  much 
greater,  that  raw  materials  containing  such 
impurity  are  considered  unfit  for  use.  A  flux 
of  fluor  spar  has  been  used  to  counteract  this 
effect,  but  with  little  success.  Magnesia  mixed 
with  carbon  and  heated  in  the  electric  furnace 
does  not  form  a  carbide  and  is  highly  infusible ; 
under  similar  conditions  barium  and  strontium 
oxides  form  carbides  with  ease. 

Silica,  iron  oxides,  and  alumina  form  silicates, 
aluminates,  and  ferro-siltcon,  which  reduce  the 
puritv  of  the  carbide  and  the  output  of  the  furnace. 

The  preparation  of  the  raw  materials  in 
carbide  manufacture  is  of  much  importance, 
owing  to  the  high  temperatures  employed  in  the 
reduction  of  the  lime.  Water  in  tne  free  state 
in  the  coal,  or  combined  as  hydroxide  in  the 
lime,  should  be  entirely  eliminated,  its  presence 
reducing  the  output  of  the  furnace  in  very  serious 
proportions.  The  coal  is,  therefore,  thoroughly 
dried  at  a  low  heat  in  some  convenient  type  of 
oven  or  rotary  diyer.  The  limestone,  consisting 
of  calcium  carbonate,  requires  a  high  tempera- 
ture to  drive  off  the  carbon  dioxide,  and  the 
operation  is  usually  conducted  in  some  type  of 
lime  kiln  fired  by  coal  or  gas. — the  Alby  works 
at  Odda  used  producer  gas-fired  kilns— or  the 
limestone  may  be  burnt  in  specially  constructed 
chambers,  using  gases  evolved  from  the  manu- 
facture of  the  carbide.  The  ingredients  were 
formerly  ground  fine  to  ensure  a  uniform  pro- 
duct, but  this  IB  now  found  unneccessary,  and 
the  limestone  is  reduced  by  crushers  to  1-2  inch 
size,  and  the  coal  to  |-}  inch  mesh.  They  are 
then  weighed  and  mixed  roughly  in  about 
theoretical  proportions  required  by  the  equation 
CaO+3C=»CaC,+CO,  or  approximately  100 
parts  by  weight  of  lime  to  65  parts  by  weight 
of  the  carbon  contents  of  the  ooaL 

The  tvpes  of  electric  furnace  which  have 
been  used  in  the  manufacture  of  carbide  may 
be  roughly  divided  into  the  intermittent  and 
coiitinuons  forms.  In  the  first  and  earlier 
type  the  carbide  was  allowed  to  solidify  in  the 
crucible,  and  was  hence  known  as  the  ingot 
furnace.    This»  or  the  pot  furnace,  ^  which 


Borcher*s  is  the  simplest  type,  consists  of  a 
large  iron  crucible  lined  on  the  bottom  with  a 
layer  of  carbon,  this  forming  one  terminal  of 
the  electrical  circuit  The  other  terminal  is 
formed  of  a  carbon  rod  which  is  suspended 
vertically  in  the  crucible,  and  providea  with 
some  form  of  mechanical  hoist  to  give  a  vertical 
motion  to  the  rod  and  holder,  which  together 
may  weigh  as  much  as  one  ton.  To  start  the 
furnace,  the  moving  electrode  ia  lowered,  until 
on  passing  a  current  an  arc  is  formed  with  the 
carbon  bottom.  The  mixture  of  lime  and  coal 
previously  prepare<l  and  stored  in  a  bin  above 
the  furnace  is  fed  in  around  the  arc  until 
entirely  covered.  A  current  of  2000  amperes 
and  75  volts  was  used  in  the  early  Willson 
furnace.  The  arc  being  started,  interaction 
soon  commences  between  the  lime  and  the 
carbon,  producing  a  pool  of  carbide,  which 
gradually  deepens,  necessitating  frequent  lifting 
of  the  electrode  to  keep  the  current  constant. 
The  process  is  continued  until  the  furnace  is 
full,  when  the  crucible  is  wheeled  out  and  an 
empty  one  substituted.  When  sufficiently  cool, 
the  contents  are  dumped  on  to  a  ffrating  to 
separate  the  unconverted  mixture,  and  the  ingot 
removed  to  a  clearing  room,  where  the  crust  is 
removed  and  the  block  of  carbide  broken  up. 

In  practice  four  tons  of  raw  material  were 
handled  to  produce  one  ton  of  carbide,  and  the 
process  was  also  unsatisfactory  on  account  of 
the  varying  quality  of  the  product,  which, 
though  pure  carbide  in  the  centre,  was  only  a 
fritt^  mixture  of  lime  and  coke  on  the  crust. 
In  order  to  improve  both  the  quality  and  out- 
put the  American  makers  adopted  a  rotating 
furnace,  of  which  the  Horry  furnace  is  the 
best-known  type.  This  is  built  in  the  form  of 
a  spool  with  wide  flanges  fastened  to  the  drum, 
producing  three  sides  of  a  square  in  cross- 
section.  The  fourth  side  is  formed  by  a  remov- 
able plate,  clamped  across  the  flanges.  Two 
electrodes,  suspended  vertically,  form  an  arc 
in  the  furnace,  a  single-phase  current  of  4000 
amperes  and  75-80  volts  being  employed. 
The  electrodes  are  fixed,  but  the  furnace  is  made 
to  rotate  at  a  peripheral  speed  of  about  6  inches 
an  hour.  In  operating  the  furnace  a  layer  of 
broken  coke  is  placed  under  the  electrodes,  the 
arc  is  sprung,  and  the  ohaige  of  lime  and  coal 
fed  in  until  the  electrodes  are  covered.  As  the 
carbide  is  formed  the  rotation  brings  the 
electrodes  into  contact  with  a  fresh  ohaige,  while 
the  fluid  carbide  slowly  solidifles  to  an  ingot 
shape,  and  is  detached  in  lai^e  blocks  at«  the 
rear  end  of  the  furnace.  In  a  modification  the 
fused  carbide  is  made  to  pass  through  a  die 
which  separatee  the  fused  carbide  from  the 
unreduced  mixture,  and  cools  the  carbide 
sufficiently  to  determine  its  shape,  whence  it  is 
withdrawn  progressively  and  detached  in  the 
form  of  a  pig  devoid  of  orust. 

In  Europe  the  early  pot  furnace  was  soon 
changed  to  a  tapping  furnace,  in  which  the 
carbide  was  heated  until  sufficiently  fluid  to 
be  run  into  oast-iron  moulds.  The  earlier 
furnaces  were  similar  in  form  to  the  pot  furnace, 
with  one  suspended  electrode,  but  it  was 
difficult  to  get  the  desired  temperature  and 
fluidity.  Two  or  more  electrodes  were,  then 
introduced,  and  the  progress  in  electric  furnace 
design  for  high  temperatoree  followed  largely  its 


7*0  CAl 

devriopment  in  the  carbide  indnstiy.  The  fur- 
nace, as  constructed  hy  Albj  in  Siveden,  used  a 
aingle-pbaM  alternating  onrrent  of  ISOO  kilowatta, 
Mid  prodaced  60-00  torn  of  carbide  per  veek. 

Tbe  eleotrodei,  which  in  the  early  dayi  of 
the  induBtrr  were  obtainable  only  in  compara- 
tively Bmall  eizea,  could  later  be  purchaswi  up 
to  22  inohea  aquaro  and  more,  and  were  also 
used  by  tome  manufactiiren  aa  an  aaaambly  of 
smaller  ones.  The  working  temperature  in  tbe 
furnace  attained  3000"  C,  though  tbe  castini; 
temperature  may  be  somewhat  lower.  To 
withstand  snoh  a  grea-t  heat  tbe  furnace,  which 
is  constructed  of  ateel  framework  and  plates, 
has  to  be  lined  with  some  refractory  material,  pre- 
ferably as  inert  as  posiible  towards  the  elements 
of  the  charge,  and,  where  the  heat  is  most  intense, 
water  coolu^  tubes  may  be  built  into  tbe  lining 
It  is  necessary  also  to  insulate  the  electrodes  to 
prevent  short  circuiting  through  the  furnaoe  ooa- 
atruction.  as  also  to  make  a  goa-tight  joint  where 
the  ctoBud  form  of  fumaoe  is  employed. 

Considerable  progress  bos  t>een  made  in 
attaining  size  and  efticicncy  by  the  uw  of 
multiphase  currents,  wbioh  has  resulted  in 
advantage  not  only  to  the  carbide  industry  but 
also  in  the  manufaoture  of  ferro  silicon  and 
otbei  ferro  alloys.  According  to  Helfenstein 
and  Taussig  (Seventh  -  Congress  of  Applied 
Chemistry),  Uie  largest  power  ooosamption 
possible  with  a  built-up  electrode  amounts  to 
2600-3000  kw.,  the  current  being  30,000-10,000 
amperes  at  76-96  volts  at  the  ejectri>de.  Tn  a 
thiee-phase  fumaoe — the  only  type  used  for 
large  units — this  means  a  total  power  con- 
Bumption  of  from  7600  to  IXKK)  kw.,  or  10,000  to 
12,000  b.p.  In  the  manufacture  of  carbide  a 
further  step  has  been  taken  in  tbe  construction 
of  double  three-phoae  furnaces,  in  which  in  the 
same  hearth  bIz  instead  of  three  electrodes  are 
employed,   connected   ta   two   separata   tbree- 

Shase  units ;  the  power  nujiiired  being  from 
3,000  to  18,000  kw.,  corresponding  to  a  produo 
tion  of  from  60  to  1 10  tons  of  carbide  in  24  hours. 
In  this  modification  there  is  no  increase  in  load- 
ing, but  it  is  interesting  as  showing  that  the 
power  capacity  so  attainable  is  unlimit^,  whereas 
any  attempt  t«  increase  the  power  of  consump- 
tion beyond  2600  to  3000  kw.  per  electrode  is 
found  to  be  impracticable  unless  tbe  furnace  is 
operated  by  entirely  special  methoda. 

In  open  furnaces  the  heat  due  to  tbe  burning 
of  the  gaseous  products  of  the  reaction  is  so 
great,  that  even  wiUi  leas  Uian  3000  kw.  per 
electrode  special  protection  against  the  heat  OM 
to  be  provided  both  for  the  workers  and  the 
electrii^  plant.  Simultaneously  the  gaaes 
evolved  become  a  serious  nuisonoe  in  open 
carbide  furnaces,  and  smoke  is  developed  dis- 
proportionately aa  the  power  is  increased,  for 
which  T«a«oa  it  is  not  advisable  to  exceed 
3000  kw.  per  electrode.  Another  obstacle  to 
the  use  of  higher  concentration  of  power  it  the 
difficulty  of  satisfactorily  charging  the  raw 
materials  into  the  fumaoe  so  m  to  keep  the 
electrodes  uniformly  covered,  any  undue  expo- 
sure leading  to  fumini:,  or  distillaUon  of  material 
due  to  oveilieatiag. 

As  the  capacity  of  the  fumaoe  is  inoieaaed 
the  utilisation  of  the  gaaea  prodnoed  by  the 
reaction  becomes  of  greater  economic  moment. 
In  tbe  carbide  furnace  70-86  p.c.  of  the  gases  is 


carbon  monoxide,  with  carbon  dioxide  ana  water, 
which  are  easily  removable  in  practice  as  the  sole 
impurities,  Fumaees  are  now  designed  entirely 
closed  in,  so  that  evolved  gas  can  be  ntilised 
for  heating  purpoaee,  and  by  so  doing  smoke  nuis- 
ance and  eicesaiva  radiaticm  of  heat  is  avoided. 
The  type  of  fumace  as  covered  by  HelfMi- 
stein's  patents  illustrate  the  main  featoiea  ot 
intenst  in  connection  with  mechanical  ohargins 
and  other  general  problems  of  management  ot 
the  electrical  fumaoe  for  the  manufactaro  of 
carbide.  Fig.  6  shows  on  olevatian  and  section 
of  an  8000-10,000  kw.  siogle  three-phase  fumace. 
About  8-10  metres  above  the  bottom  plate  it 
a  charging  floor,  where  the  raw  material  is 
brought,  as  in  blast  fumace  plants,  by  tipping 
waggons  to  the  chaigrng  apparatus  at  regular 
intervals.  The  charging  arrangements  con- 
sist of  a  large  miiirg  chamber,  which  can  be 
dosed  gas  tight,  oommunicating  wil^  the  body 
of    the    fumace,    through    which    the    central 


hanging  electrode,  of  3000-4000  k.g.  weight, 
passee,  Deing  thui  surrounded  on  all  sides  by  tbft 
mixture.  The  mixing  reservoir,  which  lua  a 
capacity  of  from  6000  to  7000  k.^.,  is  fed  con- 
tinuously  as  the  material  is  used  m  the  process 
through  large  pipes  from  tbe  charging  floor 
above.  Wide  slits  provided  with  gaa-tight 
a  are  made  in  the  top  of  tbe  fumac* 
proper,  near  the  mouth  of  the  reservoir,  for 
obeervatioa  and  control  of  the  process. 

When  no  more  profitahle  use  of  the  waste 
gaaes  is  required,  their  immediate  application 
in  preheating  the  charge  can  be  oarried  out  oa 
illustrated  in  Fig.  0-  The  general  form  of  the 
fumace  is  the  same  as  Fig.  8.  It  is  seen  that 
the  upper  part  of  the  hearth  there  is  a  gas- 
fitled  comer  apace  bounded  by  tbe  naturally 
sloped  Eurfaoe  of  the  raw  materials  ;  by  blowing 
or  sacking  air  in  at  tbe  noules,  as  indicated  in 
the  diagram,  this  space  is  converted  into  a  com- 
bustion chamber,  the  goaee  burning  in  contact 
with  the  mixture  of  matwial  in  the  he«rth. 
In  another  Austrian  modifioation  the  fumace  is 


provided  with  charging  Teuels  in  the  form  of 
shsfti  Bj-niln-'-  in  tungn  to  Helfenoteiii's,  but 
with  ft  br»och  for  taking  off  the  waste  gues. 

The  A.Q.  wotkB  near  Col<»ne,  whioh  are 
capable  of  prodaciiu  200  tona  of  carbide  a  day, 
an  described  by  Allmand  and  Willianu  (J.  Boo. 
Chem.  InA  p.  304  R.,  1919).  The  power  ii 
obtained  from  five  three-phase  tarbo-generaton 
of   11,200   kw.   each,   and   throe   - — "—    


I  working  four  furnaces,  3 
.jmed  on  power  and  light.  ' 
(umaces  conaiet  of  steel  plate  ahella  30  by  14  by 
10  feet  daep,  lined  with  18  inches  of  firebrick, 
the  hearth  or  crucible  being  afterwards  rammed 
with  carbon  concrete.  The  electrodes  SO  by  20 
inches  cross  section,  and  7  feet  6  inches  to  S  feet 
in  length,  were  built  np  of  aectiona  20  by  20  and 


20  by  10  inches.  Flange,  boss,  and  contact  head 
of  each  electrode  were  separately  WAt«r  cooled, 
and  the  current  was  carried  by  groups  of  flexible 
copper  wires  suspended  by  chains,  each  with 
separate  electric  motor  control.  The  furnaces 
were  of  the  open  type,  tbe  smoke  and  dust  being 
ezhansted  from  openings  in  the  back  wall  of  the 
furnace.    260  tons  of  lime  to  IBS  tons  of  coke 

Cday  were  required  at  full  working  pressure- 
lime  was  passed  through  a  4-inch  ring,  and 
the  coke  waa  in  pieces  1  to  3  inches  across.  The 
electrode  consumption  was  five  kilo,  per  ton  of 
carbide.  One  tap  hole  was  tapped  in  each 
fomaoe  every  4G  minutes  by  an  arc  tapper,  and 
each  furnace  was  provided  by  three  lap  holea 
placed  below  the  three  electrodes. 

The  subsequent  treatment  of  the  carbide 
requires  special  machinery,  according  to  whether 
the  material  is  to  be  used  for  the  preparation  of 
acetylene  or  for  the  manufacture  of  cyanamide. 
In  the  former  case  the  clean  ingots  are  broken 
into  large  blocks  and  fed  into  jaw  croiheis, 
from  whence  it  is  pMMd  for  granouttioii  ttitoagfa 


rUM.  741 

slow-moving  rolls,  tbe  object  being  to  attain  the 
deaii«d  state  of  division  with  a  minimum  pro- 
duction of  dust.  The  crushed  material  is  used 
on  trommels  or  rotary  screens,  which  deliver  the 
product  in  size*  varying  from  large  lutnpe 
8  by  4  inches,  for  the  manufacture  of  acetylene 
on  a  large  so^,  to  10-30  mesh  tile,  for  automo- 
bile lamps,  &c  A  sheet-iron  plant,  where 
steel  drums  and  air-tight  cans  are  manufactured 
for  storing  and  transport  of  the  carbide,  is  »  necM- 


„ I  for 

making  acetvlene,  but  the  cyanamide  Iq.v.) 
industry  is  dependent  on  calcium  carbide  for 
its  monufaoturo.  For  this  purpose  it  is  necessary 
to  reduce  the  material  to  a  fine  state  of  division, 
and  to  prevent  oxidation  and  explosion  it  is 
usually  performed  in  on  atmosphere  of  nitrogen. 

Tlie  manufacture  of  calcium  oarbide  at 
prices  prevailing  in  normal  timee  depends  upon 
the  supply  of  cheap  electric  power.  Norway, 
having  abundance  of  water  power  and  depoaito 
of  suitable  limestone,  has  long  been  the  largest 
producer  of  carbide.  According  to  C.  Bingham 
(J.  Soc.  Chem.  Ind.  March  IS,  1918),  to  produce 
a  ton  of  carbide  requires  4250  units  of  electric 
power,  this  figure  including  not  only  the  current 
required  for  the  furnace*  themselves,  but  that 
absorbed  l^  transformers  and  leads,  as  also 
that  consumed  hy  motors  to  drive  crushers, 
elevators,  pumps,  and  drum-making  plant.  The 
cost  in  Norway  with  cheap  water  power  amounted 


TEhe 


>   25«.  per 
s  selling  price  was   £10   IS*. 


Gi«at  Britain  was  at 
which,  owing  to  lack  of 
eleotno  power,  was  removed  to  Manchester, 
where  a  urge  plant  has  been  built.  At  0'4d. 
per  tutit  tbe  coat  in  Great  Britain  for  current 
alone  would  be  £0  3«.  4<f.  per  ton  of  carbide, 
but  if  the  process  was  run  in  connection  with 
blastfurnaces  and  coke  ovens  having  a  surplus 
of  electric  power  or  gas  for  the  manufacture 
thereof,  it  la  calculated  that  this  figure  could 
be  reduced  to  £2  IOj.  per  ton  of  carbide, 
reckcHkiog  O-llif.  per  unit  for  depreciation  and 
running  cost,  and  2d.  per  1000  cu.  ft.  for  gss 
used  in  gas  engines  consuming  27  cu.  ft.  per 
kw.  hour,  or  for  the  4260  units  mentioned,  a 
cost  of  199.  2d. 

Tbe  Nitrogen   Product*  and  Carbide   Co., 


kmalgomated  with  the  Alby  United  Carbide 
ties,  Ltd.,  have  acquired  tbe  St.  "  '   " 
Colliery  and  Coke  Ovens,  Workington,  w 


object  of  producing  carbide  and  nitrolin  in  this 
'-mti^  on   an   economical   basis.    Electrode* 
I  bemg  produced  at  Hebbum-on-Tyne. 
Calahim  CUbouls  CaCO,  occurs  naturally 
the  forms  of  limestone,  chalk,  marble,  and 
oatcite ;   it  also  constitute*  the  principal  ingro- 
dient  in   egg-shells,   moUusc-BhcllB,   and  coral. 
It  is  formedwhen  IJie  oxide  or  hydroxide  is  ex- 
posed to  moist  air  containing  carbon  dioxide, 
but  is  not  produced  by  the  action  of  dry  carbon 
de  on  dry  lime.     It  may  be  obtained  in 
the  ^ure  state  by  dissolving  chalk,  or  marble,  or 
colcmed  oyster-snails  in  hydrochloric  acid,  pre- 
ipitAting  the  alumina,  oxide  of  iron,  and  earthy 
lEoaphatM  by  ammonia  or  milk  of  lime,  filtering, 


742 


CALCIUM. 


then  precipitating  the  calcium  by  ammonium 
carbonate,  washing  and  drying. 

Calcium  carbonate  is  dimorphous,  orystal- 
liaing  in  the  hexagonal  system  as  calcite  (9. v.) 
and  in  the  rhombic  system  as  aragonite 
iq.v.). 

A  litre  of  water  dissolves  about  18  milligrams 
of  calcium  carbonate.    The  solution  has  a  slight 
alkaline  reaction.    Gothe  (Chem.  Zeit.  39,  305) 
gives  the  solubility  of  CaCOg  in  water  free  from 
00a  fts  being  31*0  mg.  per  litre.    It  is  increased 
by    the    presence    of    chlorides,    nitrates,    and 
sulphates  in  the  water,  but  decreased  by  alka- 
line carbonates,  and  by  chlorides,  nitrates,  and 
sulphates  of  the  alkaline  earths.    When  boiled 
with   water  CaCOg  (Gazz.   chim.   ital   47,   ii. 
49)  slowly  dissociates  with  evolution  of  COt. 
This  dissociation  stops  at  a  certain  point,  and  is 
prevented,  if  a  solution  of  Ca(OH)a  (saturated 
at  the  ordinary  temperature)  is  added  to  the 
boiling  calcium  carbonate  in  water  in  the  pro- 
portion of  16  c.c.  per  litre.    Sodium  carbonate 
(OOS    gram    per   litre)    prevents    dissociation. 
Seyler  and  Lloyd  (Chem.  Soc.  Trans.  Ill,  994) 
find  that  the  ionic  solubility  product  of  calcium 
is  [Ca-]-[CO,-]=71-9xlO-i«,  which  gives  [Ca"] 
=14*6x10-*  for  a   saturated   solution  CaCOt 
in  pure  water.    In  this  solution  the  carbonate  is 
hydrolysed  to  the  extent  of  66  p.c.    Water 
containing  carbonic  acid  dissolves  it  much  more 
readily,  forming  the  acid  carbonate  CaHa(COs)|, 
which  is  Imown  only  in  solution.    Solubility  at 
higher  pressures  in  water  containing  carbonic 
acid  follows  the  law  of  Schloesmg  pretty  closely 
(Engel,  Compt.  rend.  101,  949).    The  solubility 
increases  under  an  increase  of  pressure  only  up 
to  3  grams  per  litre  according  to  Caro.    One 
litre  of  water  saturated  with  carbon  dioxide 
dissolves  0*7  gram  of  the  carbonate  at  0%  but 
0*88  gram  at  10"".    The  solubility  of  calcite  in 
water,  determined  at  different  temperatures  by 
bubbling  air  containing  3*18  parts  of  COf  per 
10,000    until   saturation    occurs,  expressed    in 
parts  of  CaCO,  per  million  is  :  at  10^  82  ;  21"*, 
60;  22^,67;  23^  67  ;  30*,  66.    Cavazri  (Gazzi 
chim.  ital.  46,  ii.  122)  finds  that  the  maximum 
quantity    of,  CaCO,,    which    after    prolonged 
snaking,  dissolves  at  0^  in  one  litre  of  water 
saturated  with  COf  and  maintained  so  in  the 
presence  of  the  gas  at  atmospheric  pressure  is 
1*66  grams  (2*5272  grams  Ca(HCO,),);  at  16^ 
1*1752  CaCO,  (1*9038  Ca(HCO,),).    A  supjer- 
saturated    solution   is    obtainable,   containing 
2-29  grams  CaCO «  per  litre.    This  acid  carbonate 
plays  a  most  important  part  in  nature,  for 
whenever  water  containing  carbonic  acid  comes 
in  contact  with  carbonate  or  silicates  of  calcium, 
the  calcium  is  gradually  converted  into  this 
soluble  form,  and  is  therefore  found  in  almost 
all  natural  waters.     Hence  also   the  deposits 
in  kettles  and  boilers ;   the  formation  of  which 
may  be  prevented  by  the  addition  of  ammonium 
chloride  to  the  water. 

Calcium  carbonate,  when  heated  to  full  red- 
ness in  open  vessels,  is  decomjMMed  into  lime 
and  carbon  dioxide.  The  decomposition  com- 
mences at  a  low  red  heat,  and  in  a  current 
of  air,  or  better  steam,  the  temperature  of  dis- 
sociation is  lower  still.  The  tension  of  dis- 
sociation becomes  equal  to  the  pressure  of  the 
atmosphere,  according  to  Le  Chatelier  (Compt. 
rend.   102,   1243),  at  about  812*".     If  heated 


rapidly,  the  stationary  temperature  of  dis- 
sociation is  925*'.  At  647*  the  tension  of 
dissociation  is  27  mm. ;  at  610*,  46  mm. ;  at 
626*,  66  mm. :  at  740*,  246  mm. ;  at  810^, 
678  mm. ;  and  at  866*,  1333  mm.  If  the  car- 
bonate be  ignited  in  a  closed  vessel,  it  fuses, 
resolidifying  to  a  mass  of  marble-like  calcite. 
According  to  Becker  (Jahrb.  Min.  1886,  1,  ReL 
403),  any  form  of  CaCO,,  even  at  a  low  pressure, 
is  changed  on  heating  in  a  closed  space  with 
exclusion  of  air  into  the  rhombohedral  form 
without  fusion.  The  crystalline  forms  of  calcium 
carbonate  dissociate  very  slowly  below  400* ; 
at  this  temperature  the  dissociation  pressures 
are  of  the  order  of  0*003-0*009  mm.  At  426* 
aragonito  is  transformed  into  calcite  within  an 
hour  when  heated  in  a  vacuum.  Besides  the 
two  well-known  forms  a  third  crystalline  form, 
referred  to  as  fiCaCOg  (Merwin  and  Williamson, 
Amer.  J.  Sci.  41,  473),  is  obtained  by  precipita- 
tion at  60*  along  with  calcite  and  aragonite. 
It  has  D.  2*51,  and  can  be  separated  from  calcite 
D.  2*71,  and  aragonite  D.  2*88  by  flotation  in  a 
liquid  D.  2*6.  If  small  quantities  of  the  pre- 
cipitated carbonate  are  thrown  into  a  fused 
mixture  of  sodium  and  potassium  chlorides  in 
equivalent  proportions,  no  carbon  dioxide  is 
evolved,  but  the  carbonate  becomes  crystalline 
calcite,  usually  in  aggregations  of  crjrstab  like 
snow  crystals  (Bourgeois,  BulL  Soc  chim.  [2] 
37,  447}. 

Penulijrdrated  ealelam  earbonata 

CaC0„6H,0. 
The  evaporation  of  natural  solutions  of  the 
acid  carbonate  generally  results  in  the  depositran 
of  the  ordinary  carbonate,  forming  the  stalac- 
tites and  stalagmites  of  caverns,  travertine,  and 
other  forms  of  deposit;  bat  sometimes  the 
solution  fields  six-sided  rhombic  prisms  of  the 
composition  CaC0,,6HtQ.  These  crystals  are 
often  found  in  pumps  and  pipes  leading  from 
wells,  also  adhering  to  the  oonfervn  in  ponds. 
They  keep  nnaltered  under  wster  at  20^,  but  at 
dlightly  higher  temperatures  lose  their  tnuos- 
parency  and  water  of  orvstallisation  In  air 
they  crumble  to  powder  through  loss  of  water 
(Pfeiffer,  Arch.  Pharm.  [2]  15,  212).  This  salt, 
according  to  Pelouze  (Ann.  Chim.  Phys.  ^1  48, 
301),  is  obtained  in  small  aoate  rhombonedra, 
8p.gr.  1*783,  by  boiling  lime  in  a  oonoentrated 
solution  of  sugar,  starch,  or  gum,  and  leaving 
the  solution  for  some  months  in  a  cold  place. 
Booquerel,  by  exposing  a  solution  of  lime  in 
sugar  water  to  a  voltaic  battery  of  12  oeUs, 
obtained  crystak  of  the  same  composition,  but 
in  form  of  rhombic  prisms. 

Basle  earbonatea  of  lime.  Calcium  oxide 
commences  to  absorb  carbon  dioxide  at  a  tem- 
perature of  415*,  forming  a  basic  carbonate  of  the 
composition  2(JaO*COs  (Bimbaum  and  Ifahn, 
Ber.  12,  1547). 

Raoult  (Compt.  rend.  92,  1457)  shows  that 
when  freshly  burnt  lime  is  heated  in  a  oorrent  of 
carbon  dioxide,  it  glows  strongly,  forming 
2CaO'CO|,  which  does  not  disintcsrate  in  moist 
air,  and  does  not  take  up  water  from  steam  at 
200*.  When  finely  powdered  and  treated  with 
a  little  water,  it  hardens  like  hydraulic  cement. 
The  hydrated  product  has  the  composition 
CaCO,*Ca(OH)^  On  heatms  to  dull  redness,  it 
loses  water  and  is  convertea  into  a  mixture  of 
I  CaCO,  and  CaO. 


CALCIUM. 


743 


When  burnt  lime  is  heated  in  contact  with 
carbon  dioxide  for  sevoral  days,  the  basic  salt 
2CaCO,-CaO  is  obtained,  which  stiU  absorbs  CO^, 
forming  a  third  salt  3CaCO,-CaO.  The  carbon 
dioxide  oontinnes  to  be  absorbed,  ho\i'ever, 
and  appears  eTentnally  to  form  the  normal  oar- 
bonatOi 

Calcium  nitride  Ca,Na  is  best  obtained  by 
passing  diy  nitrosen  over  metallic  calcium  con- 
tained in  a  nickel  boat  and  tube  heated  to  bright 
redness.  Two  to  throe  hours  are  required,  and 
the  resulting  material  is  fritted  and  possesses  a 
brownish-red  colour.  Its  fusion  point  is  about 
1200** ;  sp.gr.  2ft3  at  17**.  When  thrown  into 
water  it  proauces  a  lively  effervescence,  yielding 
ammonia  and  calcium  hydroxide 

Ca,Ng+6H,0=3Ca(OH),+2NH, 

(Moissan,  Ann.  Chim.  Phys.  [7]  18,  289).  The 
nitride,  heated  in  a  current  of  hydrogen,  gives 
a  compound  having  the  formula  CasN^H^ 
(Monatsh.  34,  1685). 

Caleittm  ammonium  Ca(NHa)4  is  formed  when 
a  current  of  dry  ammonia  gas  is  passed  over 
metallic  calcium,  maintained  at  a  temperature  of 
J  5^  to  20^.  It  possesses  a  brownish-red  colour, 
and  .takes  fire  when  exposed  to  air. 

Calcium  amide  Ca(NH,)a.  Calcium  am- 
monium slowly  decomposes,  forming  transparent 
crystals  of  calcium  amide,  hydrogen  and  am- 
monia being  evolved. 

Calcium  imide  CaNH  is  formed  by  passing 
equal  volumes  of  hydrogen  and  nitrogen  over 
heated  calcium.  It  has  not  been  obtained  pure 
(Monatsh.  34,  1685). 

Calcium  nitrite  Ca(NO.)a3tO  is  prepared  by 
decomposing  a  boiling  solution  of  silver  nitrite 
with  hme-water,  treating  the  filtrate  with  sul- 
phuretted hydrogen  and  carbonic  acid  to  remove 
excels  of  silver  and  calcium,  and  evaporating  at 
a  gentle  heat.  It  crystallises  in  deliquescent 
prisms  insoluble  in  alcohoL 

Calcium  nitrate  Ca(N0a)a,4H,0  occurs  as  a 
silky  efflorescence  in  limestone  caverns,  especially 
those  of  Kentucky,  also  on  the  walls  of  places 
where  there  is  much  oiganic  refuse.  It  is  found 
in  many  well  waters,  b^ng  derived  from  the  soil 
It  is  extremely  deliquescent  and  soluble,  and 
causes  rapid  disintegration  of  mortckr,  and  hence 
is  called  *  saltpetre  rot.'  It  may  be  prepared 
by  dissolving  the  carbonate  in  nitric  acid,  the 
solution  de|)Osituig  on  slow  evaporation  mono- 
clinic  six-sided  prisms  terminated  by  acute 
pyramids  of  the  above  composition.  On  evapo- 
rating the  solution  to  dryness,  the  anhydrous  salt 
of  sp.gr.  2*472  is  obtained,  possessing  a  warm 
bitter  taste  and  readily  soluble  -in  water  and 
alcohol.  On  heating  more  strongly,  it  becomes 
phosphorescent,  as  noticed  by  Baldwin  in  1674, 
and  hence  is  termed  BMmn*s  phoaphorus.  At 
a  higher  temperature,  oxygen  and  nitric  peroxide 
nre  evolved,  and  with  combustible  bodies  detona- 
tion occurs.  The  nitrate  is  formed  with  libera- 
tion of  nitrogen  when  nitrogen  peroxide  acts  on 
lime,  whatsoever  be  the  conditions  of  tempera- 
ture 2CaO+6NO,  ->  2Ca(NO,),+0'5N,.  It  is 
extensively  prepared  on  the  Continent  for  the 
manufacture  of  nitre  by  mixing  vegetable  and 
animal  refuse  with  chalk,  marl,  omders,  ftc, 
moistening  from  time  to  time  with  liquid  stable 
manure,  and  exposing  to  the  air  for  two  or 
three  years,  when  the  mass  is  lixiviated  and 


the  crude  nitrate  of  calcium  decomposed  by 
carbonate,  sulphate,  or  chloride  of  potassium. 
Laise  quantities  of  calcium  nitrate  are  now 
produced  by  the  Haber  process.  At  the 
Sv&lgfos  works,  Notodden  (55,000  h.p.),  and 
the  Ryukan  works  (120,000  h.p.,  to  be  increased 
to  3(X),000  h.p.),  the  nitrous  fumes  from  the 
Birkeland  ana  £^yde  furnaces  or  the  Schonherr 
furnaces  are  absorbed  in  granite  towers  and 
the  waters  neutralised  by  limestone.  The 
wet  method  of  absorption  is  now  being  replaced 
by  a  dry  method,  which  does  not  necessitate 
the  use  of  towers,  the  nitrous  fumes  being 
absorbed  by  passing  over  lime  kept  at  a  tempera- 
ture of  about  300®.  The  conversion  to  ammo- 
nium nitrate  cannot  be  accomplished  satis- 
factorily by  the  interaction  of  ammonium 
sulphate  and  calcium  nitrate  owing  to  the  fine 
condition  of  the  calcium  sulphate,  but  this 
becomes  crystalline  if  heated  in  an  enclosed 
vessel  to  150'*-175^  which  can  then  be  readily 
separated. 

Calcium  phoqiliide,  Moissan  (C^mpt.  rend. 
128,  787)  prepared  calcium  phosphide  from  pure 
crystallis^  calcium  and  red  phosphorus.  The 
two  bodies  were  placed  apart  in  a  tube  which 
was  exhausted  and  the  phosphorus  was  gentlv 
heated.  The  vapo'urs  evolved  combined  with 
the  calcium  with  incandescence.  He  also  ob- 
tained it  by  reduction  of  pure  calcium  phosphate 
with  carbon  in  an  electric  furnace,  using  310 
parts  and  06  parts  respectively  of  the  ingredients 
and  a  current  of  960  amperes  and  45  volts.  So 
obtained,  it  is  a  brownish-red  body,  crystalline 
when  prepared  in  the  electric  furnace.  Its 
characteristic  reaction  is  the  decomposition  of 
water  in  the  cold  with  the  production  of  calcium 
hydroxide  and  hydrogen  phosphide.  Prepared 
by  either  of  the  above  meuiods,  it  has  the  com- 
position Ca,Py 

Thenard  (Ann.  Chim.  Phys.  [3]  14,  12)  ob- 
tained  oaldum  phosphide  mixed  with  phosphate 
by  passing  the  vapour  of  phosphorus  over  red- 
hot  lime,  llie  substance  may  be  prepared  on  a 
larser  scale  by  filling  a  cmoihle  with  a  hole  in 
its  hase  with  pellets  of  lime,  and  plaoin^  it  upon 
the  grate  of  a  furnace.  A  flask  containing  phos- 
phorus is  placed  below  the  gratins  with  its  neok 
passing  into  the  hole  of  the  crucifie.  When  the 
ume  has  been  heated  to  redness,  the  phosphorus 
is  gradually  heated  so  that  its  vapour  passes 
through  the  lime.  The  brown  mass  is  stated  by 
Gmelm  (Handb.  3, 188)  to  be  a  mixture  of  mono- 
oaloium  phosphide  and  trioaloium  phosphate. 

When  thrown  into  water,  the  product  is  in- 
stantly decomposed  with  evolution  of  spon- 
taneously inflammable  phosphoretted  hydrogens. 

Owing  to  this  property,  calcium  phosphide  is 
utilised  for  the  production  of  signal  fires  at  sea. 
The  manufacture  is  carried  on  in  an  aziai^- 
ment  similar  to  the  above,  the  orucihles  being 
larger  and  divided  by  a  false  perforated  bottom 
into  two  compartments,  in  the  upper  of  which 
the  pieces  of  time  are  raised  to  a  red  heat,  the 
phosphorus  placed  in  the  lower  compartment 
Doing  afterwards  volatilised  by  the  heat  radiated 
from  above.  In  about  0  hours,  a  oharae, 
yielding  20  lbs.  of  product,  is  finished,  "nie 
brown  stony  mass  is  immediately  worked  up  into 
the  *  lights.'  These  consist  of  oylindrioal  turned- 
iron  boxes,  the  lower  hidf  of  which  is  filled  with 
about  16  OS.  of  the  fragments  of  phosphide. 


744 


CALCIUM. 


Two  amaU  circular  portions  of  the  upper  and 
under  surfaoee  of  metal  are  formed  of  soft  lead, 
so  that  they  may  be  pieroed  by  a  knife  just  be- 
fore being  thrown  overboard.  The  tins  are  sup- 
ported by  a  wooden  float  when  in  use.  The 
water  enters  below  and  the  gas  issues  from  the 
upper  outlet,  burning  with  a  flame  9  to  18 
inches  high,  lasting  alK)ut  half  an  hour.  Larger 
but  similar  *  lights  '  are  prepared  to  be  placed  in 
a  bucket  of  water  on  deck.  In  the  British  Navy 
torpedo  practice,  a  pciouliar  form  of  the  phos- 
phide is  also  used. 

Caldam  phospblto  CaHPO„H,0  separates 
as  a  or3rstalUne  crust  from  a  solution  of  the 
ammonium  salt  mixed  with  calcium  chloride. 
It  is  sparingly  soluble  in  cold  water,  and  the 
solution  decomposes  when  heated,  depositing 
a  basic  salt,  an  acid  salt  remaining  dissolved. 
It  gives  off  Hs  water  at  100°.  It  is  a  white 
crystalline  powjler,  which,  on  heating,  evolves 
spontaneously  inflammable  phosphoretted  hydro- 
gen, accompanied  by  slight  detonations.  At  a 
certain  temperature,  it  oeoomes  incandescent, 
and  leaves  a  residue  of  calcium  phosphate. 

An  acid  phosphite  CaH4(P0a)s,H^0  is  ob- 
tained as  a  crystalline  cnist  by  actmg  upon 
marble  with  aqueous  phosphorous  acid  as  long 
as  carbon  dioxide  escapes.  The  crust  consists 
of  needle-shaped  crystals  soluble  in  water,  and 
losing  their  water  at  100°. 

.  Caleium  hypophosphito  Ca(POaH,),  or 
CaH4(P0a)t  is  used  medicinally,  and  is  prepared 
by  boiling  phosphorus  with  milk  of  lime 

3Ca(OH),+2P4+6H,0=2PH,-f3CaH4(PO,),. 
On  evaporation  the  hypophosphite  is  obtained 
in  monoclinic  flexible  prisms  insoluble  in  alcohol 
When  heated  it  evolves  phosphoretted  hydrogen 
and  water,  leaving  calcium  pyrophosphate. 

Calefum  orthophosphato  Ca,(P04)a  occurs 
pure  in  the  mineral  osteoiiU,  and  as 

CaB(P04)„2H,0 

in  omiihiU,  Combined  with  calcium  fluoride  or 
chloride,  it  occurs  in  nature  as  apatite 

3Ca,(P04),+CaP. 

in  which  form  it  is  found  in  large  crystals  in  the 
metamorphic  limestones  at  Burgess,  Ontario, 
Canada.  The  massive^  variety,  j^ioaphoriUt  is 
mined  on  a  laxge  scale*  at  Od^garden,  Norway. 
In  certain  apatites,  the  CaF,  is  more  or  less 
replaced  by  CaCl|.  Specimens  of  apatite  and 
phosphorite  are  occasionally  coloured  brown, 
mauve,  and  green,  and  become  colourless  on 
heating.  Apatite  is  phosphorescent  when  heated, 
especially  after  exposure  to  radium. 

Calcium  phosphate  also  forms  a  principal 
constituent  of  the  coprolitee  frequenUy  found  in 
extensive  beds  in  the  stratified  rocks.  This 
material  forms  the  principal  source  of  the  rock 
phosphate  of  commerce.  It  is  the  chief  in- 
organic material  of  bones,  forming  about  80  p.c. 
of  burnt  bones. 

It  is  obtained  in  the  amorphous  state  by  pre- 
cipitating an  ammoniacal  solution  of  calcium 
chloride  with  excess  of  hydrogen  disodium  phos- 
phate. The  precipitate  is  gelatinous,  but  dries 
up  to  a  white  earthy  powder,  nearly  insoluble  in 
water,  but  i&  decomposed  by  long  boiling  into  an 
insoluble  basic  salt  of  the  composition 

Ca,(P04>,Ca,(P04)OH 


and  a  soluble  acid  salt.  This  reaction  alao 
occurs  slowlv  in  the  cold.  Calcium  phosphate 
is  ako  soluble  in  water  containing  carbonic  add 
(I  part  m  1789  parts  of  water  saturated  with 
carbon  dioxide),  ammonium  salts,  sodium  ni- 
trate, sodium  chloride,  and  other  salts.  Its 
absorption  by  the  roots  of  plants  is  therefore 
promoted  by  the  agency  of  saline  solutions. 

Bassett  has  shown  that  only  two  phosphates 
more  basic  than  dicalcium  phosphate  exist;' 
these  are  tricaloium  phosphate  Ca,P,Og  and 
hydroxy  apatite  (Ca,Pa04)„Ca(0H)a.  The 
latter  is  the  only  stable  soUd  phase  over  a 
range  of  acidity  of  great  practical  importance, 
as  it  can  exist  in  faintly  acid,  neutral,  or  alkaline 
solutions.  It  Ib  probable  that  this  compound 
is  the  only  calcium  phosphate  that  can  per- 
manently exist  under  normal  soil  conditionsL 
Bone  phosphate  is  considered  to  be  a  mixture 
of  hy^xyapatite  and  calcium  carbonate,  with 
small  amounta  of  absorbed  bicarbonates  of 
sodium,  potassium,  and  magnesium. 

The  melting-point  of  calcium  phosphate  is 
1660°.  It  is  not  reduced  by  CO,  but  H  reduces 
it  at  1300°  to  a  mixture  of  CaO  and  phosphorus. 
Carbon  begins  to  reduce  it  at  1400°.  It  is  not 
decompbsed  by  silica  in  a  neutral  atmosphere, 
but  a  chemical  combination  occurs  at  1160°, 
and  the  product  is  completely  reducible  by 
carbon.  The  compound  has  we  composition 
3CaO,3SiOg,PaO.,  and  \b  indicated  by  a  strong 
maxinium  on  the  freezing-point  curve  of  the 
system  caldum-phosphate  calcium-silicate.  Two 
compounds  2,SiO|,PgO|,  3SiOa,PsOg,  have  also 
been  isolated,  the  latter  melting  in  the  oxyhydro- 
gen  flame. 

Freshly  precipitated  calcium  phosphate  com- 
bines with  sulphur  dioxide,  becoming  solable  in 
water.  On  heating  the  solution,  some  of  the 
gas  is  liberated  and  a  crystalline  precipitate, 
having  the  composition  Ca^OsPaOcSH^aO,  is 
formed,  a  compound  which  is  very  stable  (Ber. 
16,  1441). 

Calcium  orthophoephate  may  be  obtained  in 
the  crystalline  form  by  heating  dicalcium  pyro- 
phosphate with  water,  whereby  it  is  resolvea  mto 
phosphoric  acid  and  tricalcium  phosphate,  which 
separates  in  rectangular  plates 

8Ca,P,0,-f3H,0«2Ca,(P04),-f2H,P04. 

Tricalohun  phosphate  is  not  decomposed  by 
ignition. 

Diealolom  orthophosphate  CaaH,(P04)t.  An 
aqueous  solution  of  phosphoric  acid  acts  on 
precipitated  chalk,  forming  small  needle-shaped 
crystals  of  dicalcium  phosphate.  Dried  at  100°, 
the  salt  contains  6H.0,  wnioh  it  does  not  lose 
below  116°.  It  Is  soluble  in  ammonium  citrate. 
Boiled  with  water,  it  is  partially  decomposed 
into  tricalcium  phosphate. 

On  mixing  boiling  solutions  of  sodium  phos- 
phate, calcium  chlonde,  and  acetic  acid, 

CaiH,(P04).,H,0 

is  formed ;  M  the  solutions  are  mixed  in  the  cold« 
Ca,H,(P04)„6H,0  is  formed  (Millot,  BulL  Soc 
chim.  [2]  33, 194).  The  salt  is  also  formed  ( Joly 
and  Sorrel,  Compt  rend.  118,  741)  when  satu- 
rated solutions  are  mixed  in  the  cold  if  hydro- 
chloric acid  is  added. 

When  a  solution  of  calcium  chloride  is  mixed 
with  one  of  ordinary  sodium  ^osphate,  a  white 
crystalline  precipiUte  of  OatH,(P04)t,4H,0  is 


CALCIUM. 


746 


thrown  down.  It  is  this  salt  whioh  is  oooadon- 
ally  deposited  from  wine  in  stellar  aggregates. 
Aooording  to  Beoquerel  and  Berzelius,  a  tri- 
hydrate  may  also  be  obtained.  These  different 
results  as  regards  water  of  orystallisation  are 
probably  owing  to  the  fact  that  the  precipitates 
vary  in  amount  of  water  and  solubility  in  aoids 
according  to  the  conditions  oi  their  precipita- 
tion. 

Monoealclum  phosphate  CaH^CPOJ,  is  ob- 
tained in  rhombic  tables  by  dissolving  either  of 
the  former  phosphates  in  phosphoric  acid  and 
allowing  the  solution  to  spontaneously  evaporate. 
It  has  a  strong  acid  reaction,  and  deliquesces 
in  air,  dissolvmg  readily  in  water.  A  small 
quantity  of  water  decomposes  it,  forming  in- 
soluble dicalcium  phosphate  and  free  phosphoric 
acid.  If  cold,  the  hydrate  CaaH4(P04)„4£[aO  is 
formed ;  if  hot,  the  same  salt,  free  from  water, 
is  precipitated. 

Monocalcium  phosphate  fuses  on  Heating, 
giving  up  its  water,  and  when  heated  to  200^  it 
parts  with  the  elements  of  water,  leaving  a  mix- 
ture of  calcium  pyrophosphate  and  metaphos- 
phoric  acid 

2CaH4(P04),=Ca,P,0,-f2HPOj+3H,0. 

When  the  mixture  is  heated  to  a  still  higher 
temperature,  pure  calcium  metaphosphate  re- 
mains. 

Superphosphate  of  lime  is  a  mixture  of  mono- 
calcium  phosphate  and  calcium  sulphate,  which 
is  manufactured  as  a  manure.  It  is  prepared 
bv  acting  on  bone-ash,  rock  phoBphato,  phos- 
phorites, or  other  mineral  phosphates  with  two- 
thirds  their  weight  of  sulpnuric  acid  : 

Ca,(P04),+2H^04=CaH4(POJ,+2CaS04. 

Besides  its  use  as  a  manure  for  root-crops,  it  is 
used  in  the  manufacture  of  phosphorus  (v.  Fba- 

TILISEBS). 

Caldiim  pyrophosphate  CaaP.O,  is  prepared 
by  action  of  aqueous  pyrophosphorio  acid  upon 
lime  water,  or  sodium  pyrophosphate  upon  cal- 
cium chloride.  If  the  precipitate  thus  obtained 
IB  dissolved  in  sulphurous  acid  and  the  solution 
heated,  the  salt  separates  as  a  crystalline  crust. 
The  ci^^stals  contain  four  moleculee  of  water. 

Caleiiim  metaphosphates.  The  monosalt 
Ca(P03)|  is  obtained  by  dissolving  calcium  car- 
bonate in  orthophosphorio  acid,  evaporating,  and 
heating  the' residue  to  316^  It  is  an  insoluble 
white  powder. 

The  dimetaphosphate  Ca,(PO,)4,4H,0  is  ob- 
tained pure  in  the  crystalline  form  by  precipi- 
tating the  corresponding  alkali  salt  with  excess 
of  ccJcium  chloride.  It  is  insoluble  in  water, 
but  is  decomposed  by  strong  sulphuric  acid. 
A  double  dimetaphosphate  of  calcium  and  am- 
monium Ca(NH.)t(PO,)4,2HaO  is  obtained  in 
■pioular  crvstals  by  mixing  a  solution  of  calcium 
chloride  with  excess  of  the  ammonium  salt.  It 
is  insoluble  in  water. 

Phosphato-ehlorides  of  ealetum  are  obtained 
by  evaporating  solutions  of  tricalcium  phosphate 
in  hydrochloric  acid.  A  saturated  solution,  on 
spontaneous  evaporation,  deposits  rhomboidal 
plates  of  7CaBr4(P04),-CaCla,14H,0.  If  the 
solution  is  evaporated  over  the  water-bath,  di- 
calcium phosphate  is  first  deposited,  then,  on 
further  evaporation,  the  above  phosphatio  chlor- 
ide comes  down,  and  afterwards  white  sc^es  of 
C»H4(P04).*CaCla,HaO.     When    a    solution    of 


dicalcium  orthophosphate  in  hydrochloric  acid 
is  saturated  at  ordinary  temperatures  with  tri- 
calcium phosphate,  then  mixed  with  half  the 
quantity  of  hydrochloric  acid  already  contained 
in  it,  and  evaporated,  on  cooling  below  6^  crystals 
separate  out  of  the  composition 

4CaH4(P04),*Caas,8H,0 
(Erlenmeyer,  J.  1857,  146). 

Calcium  siUco-phosphate.  According  to 
Carnot  and  Richard  (Compt.  rend.  97,  316),  the 
brownish-black  slag,  formed  in  working  the 
Thomas-Gilchrist  process  at  Joeuf  (Meurthe-et- 
Moselle),  ia  covered  with  black  crystals,  some 
slender  needles,  others  right  rhombic  prisms 
with  brilliant  faces,  frequently  aggregated  in 
columnar  masses  terminating  in  vitreous,  trans- 
lucent, blue  crystals.  Similar  blue  cr3rsta]s  are 
found  in  the  cavities,  possessing  the  constant 
composition  8P,03-8SiO,-AlsO,'FeO*36CaO, 
essentially  a  calcium  silioo-phosphate 

Cat(P04)s+Ga,Si04. 

Caldum  arsenates.  Dicalcium  arsenate  oc- 
curs native  as  haidingerUe  Ca,H|(As04)„H,0, 
and  pharmacoliU  CatH|(As04)s,5HtO,  and  may 
be  prepared  by  adding  a  solution  of  disodium 
arsenate  to  excess  of  calcium  chloride.  The 
tetrahydric  arsenate  obtained  by  addition  of 
lime  water  to  arsenic  acid  is  soluble,  while  the 
tricalcium  arsenate  is  insoluble  in  water,  and 
may  be  prepared  by  precipitating  calcium  chlor- 
ide with  trisodium  arsenate.  On  evaporating 
a  hydrochloric  acid  solution  of  calcium  ammo- 
nium arsenate  with  platinum  chloride,  the  mass 
left  on  ignition  of  the  platinochloride  is  found 
to  contam  fine  white  prisms  of  the  tricalcium 
orthoarsenate  Cas(A804)a  insoluble  in  acids. 
The  metaarsenate  Ca(A80t)t  is  formed  as  an 
insoluble  crystalline  powder  when  mixtures  of 
arsenious  anhydride  and  calcium  carbonate  are 
ignited. 

According  to  R.  H.  Robinson  (J.  Agric. 
Res.  1918,  13,  281),  pure  calcium  hydrogen 
arsenate  (CaHAsO^,H.O)  may  be  prepared  by 
pouring  an  acidifiea  solution  of  calcium  chloride 
into  an  acidified  solution  of  sodium  hydrogen 
arsenate.  It  forms  a  heavy  voluminous  pre- 
cipitate which  may  be  obtained  ciystalune. 
It  becomes  anhydrous  at  175^.  Tricalcium. 
arsenate  Caa(A804)2,2HaO  may  be  prepared  by 
pouring  an  alkaline  calcium  chlonde  solution 
into  an  alkaline  sodium  hydrogen  arsenate 
solution,  when  a  heavy  voluminous  sparingly 
soluble  precipitate  of  sp.gr.  3'23  ia  formed. 

Calclom  ammonium  arsenate 
CaNH4AsO,.7H,0 
is  produced  by  mixing  a  hot  solution  of  arsenic 
acid  in  excess  of  ammonia  with  calcium  nitrate 
or  chloride,  when  it  ciystallises  on  cooling  in 
tables.  In  a  vacuum  over  sulphuric  acid,  they 
become  Ca,(NH4)Ha(As04)„3HaO,  and  when 
dried  at  100®  have  the  composition 

Ca,(NH4)H5(A804)„3H,0 
On  ignition  they  are  converted  into  calcium  pyro- 
arsenate  Ca^AssOj  (Bloxam,  Chem.  News,  54, 
168). 

Another  salt,  Ca(NH4)2H,(  A804)g,  is  obtained 
by  adding  excess  of  ammonia  to  a  solution  of 
dicalcium  ckrsenate  ia  nitric  acid,  as  a  flocculent 
precipitate,  soon  becoming  a  mass  of  needles. 
The  same  salt  is  obtained  in  crystals  belonging 
to  the  regular  system  when  the  solution  of  the 


746 


CALCIUM. 


dicalcium  salt  is  onlv  partially  preoipitated  and 
allowed  to  stand ;  neaoe  it  appears  to  be  di- 
moiphous  (Baumann). 

Calelum  silieide  was  obtained  by  Moissan  by 
heating  calcium  oxide  with  excess  of  silicon  in  a 
carbon  tube  by  means  of  the  electric  furnace. 
It  forms  greyish  crystals,  sp.gr.  2*5,  which  are 
slowly  decomposed  by  water  with  eyolation  of 
hydrogen. 

Tamaru  (Zeitsch.  anorg.  Chem.  62,  81)  found 
that  molten  silicon  is  miscible  with  molten 
calcium  in  all  proportions. 

Kolb  (Zeitsch.  anorg.  Chem.  64,  342),  by 
heating  together  calcium  and  silicon,  obtained 
two  silicicus  according  to  the  component  in 
excess.  The  products  contain  63 '5  p.c.  and 
36*68  p.c.  silicon  reepectiYely,  corresponding 
approximately  with  the  formuln  CaeSi^t  and 
Ca.iSiif.  Both  silicides  are  crystalline,  evolye 
hydrogen  with  acetic  acid,  and  eyolve  spontane- 
ously inflammable  hydrogen  with  dilute  hydro- 
chloric acid  Silicones  are  obtained  with  strong 
hydrochloric  acid.  Both  silicides  absorb  nitro- 
gen near  1000^,  the  products  having  the  respec- 
tive compositions  CaSiiN^  and  Ca^iSiioNif. 

Caletom  siUeatM.  Calcium  oxide  is  an 
important  base  in  a  large  number  of  natural 
silicates,  and  Ib  the  principal  basic  constituent 
of  the  following  minerals :  WoUaaionUe  CaSiOt 
or  tabular  spar,  occurring  in  monodinic  otystab ; 
oibenite  CaHs(8iO,)a»H.O ;  x(}ndlU6 

4CaSiO„HsO ; 

guroliU    CasH,(SiO,)„HaO ;     and    apopkyOiU 
4CaH,(SiO,),KJP,4H,0. 

Gorgeu  (Compt.  rend.  99,  256)  obtained  arti- 
ficial woUastonite  bv  fusing  1  gram  of  silica  with 
16  grams  calcium  ohloride  and  3  grams  common 
salt  at  a  cherrv-red  heat  in  a  current  of  moist 
air  for  half  an  hour. 

Doelter  (Jahrb.  Min.  1886, 1, 119)  found  that 
in  absence  of  steam,  a  hexagonal  CaSiO,  is 
always  formed;  hence  wollastonite  must  have 
been  formed  in  presence  of  steam.  Calcium 
silicate  is  Uierefore  dimorphous. 

Rankin  and  Wright  (Amer.  J.  ScL  39, 1)  have 
examined  the  system  CaO— AltO,-SiOt.  The 
melting-points  of  the  three  components  are 
2670*  for  lime,  2050''  for  alumina,  and  1626'' 
for  cristabolite,  the  high  temperature  modifica- 
tion of  silica.  Of  the  binary  systems  involved 
alumina  and  silica  form  one  compound,  sillima- 
nite  Al,SiOg,  whilst  lime  and  alumina  form 
four  distinct  compounds,  Ca^AlgO^,  Ca^AlcOii, 
CaAl,04,  and  Ca,AlioO„.  The  third  binary 
system,  lime-silica,  also  gives  rise  to  four 
compounds,  Ca,SiOs,  Caa8iO«,  Ca;3i.0T,  and 
CaSiO,,  the  first  mentioned  of  which,  however, 
does  not  separate  from  the  fusion.  In  the 
ternary  system  three  compounds  exist,  but  only 
anorthite  Ca,Al,SitOs  and  CaaAlaSiO|  (7  pure 
gehlenite)  are  stable  at  their  melting-point,  the 
third  Ca,AlaSiOa  being  unstable.  The  above 
compounds  do  not  form  solid  solutions  to  any 
extent,  and  the  authors  did  not  detect  in  the 
crystallisations  the  eutectic  (fi)  structure  com- 
monly seen  in  alloys. 

On  precipitating  the  solution  of  any  calcium 
salt  wiUi  sodium  or  potassium  silicate,  the  sili- 
cates 2CaO-9SiOa,3H.O  and  CaO'SiOt  have 
been  obtained  by  Leiort  and  Von  Ammon  re- 
spectively. 


Gorgeu  (Compt.  rend.  99, 266)  obtained  two 
chloromicatee  by  heating  to  a  high  temperatore 
silica  and  calcium  chloride  in  proportion  of  one 
molecule  to  seven  in  presence  of  water  vapour. 
The  first,  2CaO*SiOa-CaCl|,  forms  birefractive 
riiombic  plates.  The  second,  CaO'SiO^'CaCIg, 
forms  hexagonal  plates,  and  is  produced  more 
rapidly  tlum  the  former,  which  requires  pro- 
longed heating.  Both  compounds  are  deoom- 
poMd  hy  wat^. 

Calelum  boride  CaBg  was  obtained  by  Moissan 
and  Williams  by  heating  quicklime  with  boron 
in  an  electric  furnace,  and  by  reducing  calcium 
borate  with  aluminium  in  the  presence  of  carbon, 
then  washing  with  hydrochloric  and  hydro- 
fluoric acids  and  ether.  It  is  a  bUok  crystalline 
body;  8p.gr.  2*33.  Nitric  acid  attacks  it 
vigorously. 

It  is  also  formed  (Ber.  46,  1886)  when 
oalciun)  metaborate  (30  grams)  is  reduced 
by  means  of  calcium  (50  grams),  the  theoretical 
quantity  of  calcium  boride  being  produced. 
The  reaction  product  is  extracted  with  dilute 
acetic  acid,  and  then  dilute  HCl  and  hot  water. 
So  obtained  it  is  a  light  brown  micro-crystalline 
powder  D"=2'll. 

Calelnm  borate  occurs  in  nature  in  several 
combinations.  The  best  known  la  colemanite 
HCa(B0a)„2H,0,  which  crystallises  in  beautiful 
monoclinic  prisms. 

Caleium  sflleoborate  Ca0'2Si0g-CaB.O4 
occurs  with  one  molecule  of  water  as  (foMoMe, 
and  with  two  molecules  of  water  as  boiryoliie* 

Calelom  titanato  or  CaTiO^  occurs  in  nature 
dS  vcTOVskiic* 

Caldum  sUtootttanato  CaSiTiOg  is  a  oommoii 
constituent  of  many  igneous  and  metamon>hio 
rocks,  and  is  known  as  titaniU  or  spkene. 
Synthetic  titanite  forms  blue  crystals  (melting- 
point  1221"),  which  usually  enclose  small  cry9^ 
tals  of  perovskite  (Zeitsch.  anonr.  ChenL  73,293). 
Caleium  monosulpliide  CaS.  Perfectly  dry 
lime  remains  unaltered  on  passing  over  it  a 
current  of  dry  sulphuretted  hydrogen ;  but  on 
hydrating  the  lime  and  again  passing  the  gaa, 
calcium  sulphide  is  formed  : 

Ca(OH).-{-H^»OaS-f2HtO. 
The  most  favourable   temperature  is    60" 
(Veley,  Chem.  Boo.  Trans.  1886,  478). 

It  may  also  be  prepared  by  heating  the  sul- 
phate  with  coal  or  ohaxooal,  or  by  action  of 
carbonic  oxide  at  a  xed  heat : 

CW304+4CO-CSiiS-l-400r 
It  may  be  prepared  in  the  crystalline  state 
by  direct  reduction  of  the  sulphate  with  carbon 
in  the  electric  furnace;    Mfkller  (Cent.   Min. 
1900,  178)  has  obtained  it  in  small  cubes. 

Anhydrous  calcium  sulphide  i$  a  white  powder 
which  emits  a  smell  of  SH,  in  the  air.  it  turns 
yellow  on  moistening,  due  to  the  formation  of 
oxidised  products.  It  is  but  sparinffiy  soluble 
in  water,  and  is  decomposed  bv  boiung  water, 
with  formation  of  hydroxide  and  sul^ydrate  of 
calchim  2Cafi-f 2H,0=CWHS),-fOa(HO)t.  Bus- 
pended  in  water,  it  is  readily  decomposed  by  ear- 
bonic  acid,  with  formation  of  calcium  carbonate 
and  sulphuretted  hydrogen 

CaS+H,0+00,-OaOO,+H|a 
After  bemg  heated,  osloium  sulphide  shines  in 
the  dark,  and  was  long  known   as   Canlon*4 
\  phosphorus. 


CALCIUM. 


747 


According  to  Vemeuil  (Compt.  rend.  103, 
600),  calcium  sulphide  with  a  violet  phosphor- 
esconce  may  be  prepared  as  follows :  20  grams  of 
finely  powdered  Ume,  obtained  by  heating  the 
shells  of  Hypopw  vulgaris^  is  intimately  mixed 
with  6  grams  of  sulphur  and  2  grams  of  starch, 
and  8  co.  of  a  solution  containing  0-5  gram  basic 
bismuth  nitrate  and  100  o.c  of  absolute  alcohol 
acidified  with  a  few  drops  of  hydrochloric  acid 
are  added.  The  mixture  is  exposed  to  the  air 
until  most  of  the  alcohol  has  evaporated,  and  is 
then  heated  to  cheny  redness  for  20  minutes. 
When  completely  cooled,  the  upper  layer  of  cal- 
cium sulphate  is  removed,  and  the  calcined  mass 
powdered  and  again  heated  for  16  minutes.  The 
violet  phosphorescence  of  the  product  is  due  to 
the  trace  of  bismuth.  0*1  p.c.  of  sulphides  of 
antimony,  cadmium,  merouiy,  tin,  copper,  lead, 
uranium,  platinum,  or  zinc  imparts  a  bluish-  or 
yellowish-green  tint  to  the  phosphorescence. 
Manganese  produces  an  orange  shade.  A  mix- 
ture of  100  parts  lime,  30  purts  sulphur,  10  of 
starch,  and  0-035  of  lead  acetate  yields  a  sulphide 
with  a  beautiful  yellowish-green  phosphorescence. 

Pure  calcium  carbonate  mixed  with  2  p.o. 
sodium  carbonate,  and  0-02  p.c.  common  salt, 
heated  with  30  p.c.  sulphur  and  0-02  p.o.  bis- 
muth nitrate,  yields  a  similar  product  to  that 
obtained  by  use  of  Hypopiu  shells.  Pure  calcium 
sulphide  does  not  phosphoresce ;  the  phenomenon 
is  Que  to  small  quantities  of  impurities ;  thus  in 
the  last  mixture  it  has  been  shown  by  Vemeuil 
to  be  due  to  simultaneous  presence  ol  traces  of 
bismuth  oxide,  sodium  carbonate  and  chloride, 
and  calcium  sidphate. 

These  phosphorescing  varieties  of  calcium 
sulphide  are  utilised  in  the  manufacture  of 
luminous  pamt^  Abney  (PhiL  Mag.  [51 13,  212) 
found  that  the  emission  spectrum  showed  neatest 
luminosity  between  Q  and  F,  and  a  feebler  one 
extendmg  from  between  E  and  F  as  far  as  the 
red.  The  rays  of  the  electric  light  somewhat 
beyond  H  on  one  side  and  Q  on  the  other  are 
most  active  in  exciting  phosphorescence. 

Calelum  dbulphlde  CaS^  is  deposited  in 
yellow  crystals  of  the  composition  CaSg^SH^O 
from  the  solution  obtained  by  boiling  sulphur 
with  milk  of  lime  and  filtering  while  hot. 

Caldum  pentasulphlde  CaS.  is  formed  when 
the  monosulphide  or  hydrate  of  calcium  is  boiled 
for  a  long  time  with  excess  of  sulphur.  Con- 
centrated solutions  of  calcium  hydrosulphide 
Ca(HS)a  also  react  eneigetically  upon  powdered 
roll  sulphur ;  on  preventing  access  of  air  by  per^ 
forming  the  operation  in  a  current  of  hydrogen, 
an  orange-red  solution  is  produced  with  fafi  of 
temperature,  and  on  warming  the  calcium  is 
completely  converted  into  CaS,.  The  reaction 
is  reversible,  a  current  of  sulphuretted  hydrogen 
causing  deposition  of  sulphur  and  reformation 
of  hy(m)sulphide. 

Auld  obtained  evidence  indicating  the 
possible  existence  of  poly^ulphides  as  high  as 
CaS  7,  and  suggests  the  constitution 


Ca<j\s.S.S.  .  .  . 


the  atoms  of  sulphur  in  the  chain  becoming 
progressively  more  loosely  attacked*  (For  the 
chemical  composition  of  lime-suldbur  animal  dips, 
Me  Chapin,  U.S.A.  Dept  Agrio.  Bull  451,  1916). 


Calelum  (nysnlpliides.  When  calcium  hydrox- 
ide  is  used  as  above,  besides  CaSg  there  is 
also  formed  an  oxysulphide  of  the  composition 
5CaS-CaO,20HaO  (Rose).  The  same  substance 
ia  obtained  in  gold-coloured  needles  when  the 
solution  obtained  by  boiling  crude  calcium 
monosulphide  with  much  water  is  evaporated. 

Accordiog  to  Hoffmann  (Comptb  rend.  62, 
291),  a  mixture  of  two  molecules  of  calcium  mono- 
sulphide and  one  molecule  lime  at  a  red  heat» 
forms  the  oxysulphide  2CaS'CaO.  This  oxy- 
sulphide is  contained  in  recently  lixiviated  soda 
residues. 

Geuther  (Annalen,  224, 178)  obtained  crystals 
of  CaS,*2CaO,10HaO  by  boihng  sulphur  in  milk 
of  lime.  They  dissolve  in  hydrochloric  acid, 
forming  hydrc^en  persulphide  H^St,  and  a  little 
H|S.  On  bouing  calcium  monosulphide  and 
sulphur  with  water,  crystals  of  CaSt'3&0,15H|O 
were  obtained.  Divers  obtained  a  compound  of 
the  formula  llCaS'5CaO  by  ignitins  Hme  in 
a  mixture  of  carbon  dioxide  and  carbon  disul- 
phide. 

Auld  (Chem.  Soc.  Trans.  107,  4d0),  by  boiling 
together  lime  and  sulphur  in  proportions 
calculated  to  give  the  disulphide  obtained  in 
each  case  Herschell's  crystals,  for  which  he 
proposes  the  formula  CaO,CaS2,7H|0.  A  lime 
sulphur  wash,  used  as  a  fungicide,  is  prepared 
by  boiling  together  one  part  of  quicklime,  two 
or  more  parts  of  sulphur,  and  ten  parts  of  water. 
The  concentrated  commercial  product  contains 
calcium  polysulphides  and  thiosulphate,  generally 
with  minor  proportions  of  sulphite  and  sulphate. 

Calcium  sulphydrate  Oa(HS)a  is  formed  to- 
gether with  the  hydroxide  when  the  monosulphide 
is  boiled  with  water.  The  best  mode  of  pre- 
paring it  is  to  pass  sulphuretted  hydrchron 
through  the  hydroxide  or  sulphide  suspended  in 
water,  with  constant  agitation,  until  it  ceases  to 
be  absorbed.  It  is  difficult  to  obtain  in  the  solid 
state,  being  decomposed,  when  the  stage  of  crjrs- 
talllsation  is  reached,  into  SH|  and  OsS  which 
feparates  in  silky  prisms. 

Divers  (Chem.  Soc.  Trans.  1884, 270)  obtained 
it  in  the  solid  form  by  f orcinff  sulphuretted  hydro- 
gen through  semi-solid  caE)ium  hydroxide  and 
u*ater  so  as  to  obtain  a  saturated  solution  of  the 
sulphydrate.  Air  was  excluded,  and,  on  settling, 
decanting  in  a  stream  of  H,Sy  and  cooling  by 
ice,  oiystals  formed  in  abundance.  Thibj  were 
colourless  prisms,  melting  on  slight  rise  of  tem- 
perature with  partial  decomposition.  They 
readily  dissolved  in  a  fourth  of  their  weight  of 
water,  and  could  not  be  removed  from  the  atmo- 
sphere of  sulphuretted  hydrogen  without  deoom- 
position.    They  possessed  the  formula 

CaH;3t,6HsO. 

Calcium  sulphydrate  may  be  used  as  a 
depilatory.  If  sulphuretted  hydrogen  be  passed 
into  thin  milk  of  lime  till  the  mass  acquires  a 
bluish-crey  colour,  the  paste  thus  formed,  when 
thinly  laid  upon  the  surface  from  which  the 
hair  is  to  be  removed,  permits  of  the  ready  re- 
moval of  the  hair  a  minute  or  two  afterwards  by 
scraping  with  a  dull  knife.  It  has  been  pro- 
posed to  employ  it  in  the  tan-yard. 

Calelum  hydroxy-tulphydrate  Oa(SH)(OH) 
is  formed,  according  to  Divers,  by  action  of  water 
upon  the  crystals  of  the  last-described  salt : 

Ca(SH).-f H.O  -  Oa(SH)OH-fH^ 


748 


CALCIUM. 


Also  b^  union  of  water  with  calcium  sulphide, 
as  in  interior  of  heaps  of  soda  waste ;  and  dv  re- 
action between  Oa(OH),+H^S  in  the  ooal-gas 
purifier.  Exposed  to  air»  crystals  of  Ca(HS)t  are 
rapidly  converted  to  Ca(SH)OH,  and  concen- 
trated solutions  of  the  sulphydrate  exposed  to 
air  become  rapidly  covered  with  crystals,  and  an 
abunduit  crop  of  crystals  of  Ca(SH)OH  is  ob- 
tained on  passing  in  a  current  of  air.  The 
crystals  are  oolouness  four-sided  prisms  of  silky 
lustre,  easily  obtained  dry,  of  the  composition 
Cs(SH)0H,3H,0.  Thev  slowly  evolve  SH,  in 
air,  and  become  yellow  by  absorption  of  oxygen. 
They  are  readily  soluble  in  water,  but  the  solution 
rapidly  decomposes  into  hydroxide  and  sulphy- 
drate.   l!hej  are  insoluble  in  alcohoL 

Accordmg  to  Folkard  (Chem.  News,  49, 258),  bv 
exposing  calcium  hydroxide  to  the  action  of  suL 
phuretted  hydrogen  until  it  ceases  to  gaui  weight 
a  grey  powder  of  the  composition  4Ca(HO)s'3H^ 
is  obtained.  By  the  action  of  coal  gas  sid- 
phuretted  hydrc^en  is  evolved  from  it,  and  at 
100"  water  is  eliminated*  leaving 
Ca(OH),-Ca(SH)OH. 

This  greyish-green  powder,  when  gently  heated 
in  oou  gas,  leaves  a  yellowish- white  salt 

2Ca(H0),-ai(SH)0H-CaS, 

and  this  at  a  red  heat  forms  2CaO-Ca(SH)OH-CaS, 
which,  when  ignited  in  air,  bums  like  tinder  to 
CaS04. 

The  lime-sulphur  solutions  employed  as 
insecticides  and  plant-sprays  in  affriculture, 
prepared  by  boiling  together  water,  lime,  and 
sulphur,  consist  makilv  of  calcium  jpolysulpliides, 
calcium  hydroxyrsulpnydrate,  calcium  tniosul- 
phate  with  snlphur  held  in  solution.  For  their 
analvsiB,  see  Bodnar,  Chem.  Zeit.  1916,  39,  715 ; 
Analyst,  1915,  513;  Ramsay,  J.  Agrio.  Sci. 
1914,  6,  470.  The  following  is  an  analysis  of  a 
typical  lime-sulphur  spray,  sp.gr.  1*3735,  the 
results  being  expressed  in  grams  per  100  c.o. 
(Ramsay,  /.c.) : — 

Sulphur.  lime. 

Hydroxy-sulphydrate  associated 

contiwiing         .  0*944  with  calcium  1*653 

Bisulphide  containing     14*716  ^        12*877 

Free  sulphur         .  23*11  — 

Thiosulphate  containing  0*99  0*86 

Sulphate  „  0*07  0*11 

39*83  15*50 

Caleimn  lulphoearboiutta  OaCS,.  Lime 
over  which  coal  gas  containing  sulphuretted 
h^droffen  has  been  passed  readily  absoros  carbon 
disulpnide.  Absorption  is  most  complete  when 
the  hme  is  moistened  with  water ;  this  material, 
when  folded,  is  mixed  with  an  equal  weight  of 
slaked  lime.  The  absorption  of  carbon  disulphide 
stops  when  one-third  of  the  sulphide  is  con- 
veiited  to  sulphocarbonate  CaS-f  GS,  ■■  CaCS,. 
On  exposing  the  product  for  a  short  time  to  the 
air,  it  is  again  rendered  capable  of  removing 
carbon  disulphide. 

On  passing  hvdrogen  saturated  with  vapour 
of  carbon  disulphide  into  a  mixture  of  calcium 
monosulphide  and  a  little  water,  the  liquid  be- 
comes rra,  and  in  vacuo  deposits  red  prismatio 
very  deliquescent  needles  of  composition 

Ca(OH),*CaOS„7H,0. 

When  the  hydroxy-sulphydrate  is  employed  in- 
stead of  monosulphide,  yellow  crystals  of 


2Ca(OH)s*CaCSs,lOH,0 

are  obtained. 

From  these  facts  Veley  (Chem.  Soo.  Trans. 
1885,  478)  concludes  that  the  carbon  disulphide 
is  absorbed  by  Ca(SH)OH,  and  not  by  CaS,  and 
that  the  reactions  are  as  follows : — 

(1)  CaS-f  H,0  -  Ca(SH)OH. 

(2)  Ca(SH)3.f  H«0  =  Oa(SH)OH-f  H^ 

(3)  2Ca(SH)0H-fCSa  -  Oa(OH),-CaC8,-f-H^ 

The  basic  sulphocarbonate  is  unstable^ 
being  decomposed  slowly  by  sulphuretted  hy- 
drogen and  readily  by  carbon  dioxide. 

When  milk  of  lime  is  agitated  with  carbon 
disulphide,  bright  orange  needles  of  a  basio 
sulphocarbonate  Ca(H0),'0aGSt,6H|0  are  de- 
posited. 

Caleiiim  selenUes.  The  monoselenide  is 
formed  as  a  flesh-coloured  precipitate  by  pre- 
cipitating calcium  chloride  with  potassium 
monoselenide.  lime  water  saturated  with  sele- 
niuretted  hydrogen  deposits  crystals  of  calcium 
selenide  when  exposed  to  the  air.  When  lime 
and  selenium  are  heated  just  below  redness,  a 
polyselenide  mixed  with  calcium  selenite  is 
formed. 

Calelum  sulphite  OaSO,  is  formed  wheia  a 
solution  of  an  alkaline  si^phite  is  added  to  the 
solution  of  a  calcium  salt :  it  is  a  white  powder 
soluble  in  800  parts  of  water.  It  dissolves  in 
sulphurous  acid,  and  the  solution  on  exposure 
to  air  deposits  six-sided  needles  of  the  composi- 
tion CaS0„2H,0. 

The  solution  in  sulphurous  acid  is  known 
commercially  as  bisulphite  of  lime,  and  is 
manufactured  by  passing  sulphur  dioxide  into 
milk  of  lime.  In  Kymuiton's  process  (P^t. 
15659,  1884)  a  mixture  of  caloiuih  chloride  solu- 
tion, ma^esia,  and  a  little  carbonate  of  lime  is 
brought  mto  contact  with  sulphur  dioxide.  The 
SO  I  IS  caused  to  ascend  a  flagstone  tower  packed 
with  pigeon-holed  brickworl^  while  the  mixture 
is  allowed  to  run  down  the  tower  in  such  propor- 
tions, that  from  the  baee  there  runs  a  mixture  of 
neutral  calcium  sulphite,  suspended  in  a  solu- 
tion of  magnesium  chloride  containing  the  excess 
of  sulphurous  acid.  The  sulphite  is  settled  out 
in  tai^,  the  supernatant  liquor  drawn  off  and 
concentrated  to  0*-4&*Tvr. ;  then  a  quantity  of 
alkali  waste  is  added  to  it  in  a  dosed  iron  vessel, 
and  the  whole  heated,  when  sulphuretted  hydro- 
gen is  given  off,  and  calcium  chloride,  magnesia, 
and  calcium  carbonate  with  alkali  cinders  remain. 
The  latter  are  removed  in  a  strainer,  and  the 
emulsion  is  ready  to  be  again  treated  with  sulphur 
dioxide.  The  whole  of  the  oaldnm  carbonate 
present  is  converted  to  sulphite,  carbon  dioxide 
being  evolved. 

According  to  Bimbaum  and  Wittioh  (Ber. 
13,  651),  calcium  oxide  does  not  absorb  sulphur 
dioxide  gas  below  400*,  but  at  this  temperature 
combination  takes  place  rapidity  with  formation 
of  a  basic  sulphite  Ca,S,0i.  or  60aO*6SO^  At 
500*  the  gas  is  rapidly  absorbed,  but  the  sulphite 
splits  up  into  sulphate  and  sulphide. 

Calcium  sulphate  CaS04  is  frequently  found 
in  limestone  rocks  or  in  company  with  common 
salt  in  the  anhydrous  state  as  the  nunend  anhy- 
drite.  Anhydrite  occurs  both  in  rhombic  crystals 
and  in  a  semi-crystalline  massive  fonn.  Clear 
colourless  cxystals  are  coloured  blue  by  exposure 
to   radium,   and   are  stightly   phosphorescent 


CALCIUM. 


749 


when  heated.  More  freqaently  the  sulphate  is 
found  hydrated  as  gypsum  CaS0«,2Il|0,  of 
which  the  weU-ciyBtallised  form  is  tenned 
eeknite,  a  fibrous  Variety  Miin-spar,  and  a 
finely  orystallo-granular  form  alabaster.  Selenite 
oooun  m  fine  monoclinio  prisms,  frequently 
twinned  in  charaoteristio  arrow-head  shapes. 

Gypsum  is  found  in  the  Keuper  marls  in 
Nottmghamshire,  and  at  CheUaston  in  Derby- 
shire. Selenite  crystals  exposed  to  radium  are 
occasionally  coloured,  in  parts,  a  faint  smoky 
brown. 

The  anhydrous  sulphate  may  be  artificially 
obtained  in  crystals  resembling  anhydrite,  of 
8p.gr.  2-9,  by  fusing  calcium  chloride  with  excess 
ci  potassium  sulphate  (Manross,  J.  1852,  9). 

Hydrated  calcium  sulphate  is  precipitated  on 
adding  dilute  sulphuric  acid  or  a  soluble  sulphate 
to  an  aqueous  soijitlon  of  calcium  chloride.  The 
sp.gr.  of  gypsum  is  2*31.  When  it  is  heated 
to  100*'-200^  it  gives  up  three-fourths  of  its 
water  rather  quickly,  but  it  requires  a  tem- 
perature of  20U°~250*'  to  expel  the  remainder. 
Dried  at  lOO"",  the  hydrate  20aS04,H,0  of  sp.gr. 
2'7  is  left.  The  anhydrous  salt  fuses  at  a  red 
heat  without  decomposition,  and  on  cooling, 
assumes  the  structure  of  anhydrite.  When  de- 
hydrated calcium  sulphate  is  pulverised  and 
mixed  with  water,  it  absorbs  two  molecules  of 
water,  and  solidifies  to  a  very  hard  mass  with 
evolution  of  heat,  expanding  in  so  doing  so  as  to 
fill  any  mould  in  wmch  it  is  cast,  due  probably 
to  the  outward  thrust  of  the  lath-shapea  crystals 
of  the  hydrated  salt  during  growth ;  hence  the 
use  of  ^psum  or  plaster  of  Paris  in  preparing 
casts.  If  the  gypsum  has  been  heated  to  a  little 
over  200°,  thus  being  deprived  of  all  its  water,  it 
becomes  dead  burnt,  and  takes  up  water  very 
slowly  and  without  hardening. 

Calcium  sulphate  is  very  slightly  soluble  in 
water,  the  anhydrous  sulphate  being  nearly 
insoluble.  The  solubility  of  the  hydrate  attains 
a  maximum  at  35^  one  part  dissolving  in  393 
parts  water  (Pog^iale) ;  at  0°  in  488  parts,  and 
at  100°  in  460  parts.  The  solubility  is  increased 
by  presence  of  hydrochloric  or  nitric  acids,  or 
chlorides  of  ammonium  or  sodium,  hence  its 
presence  in  salt  springs ;  probably  in  most  cases 
partial  double  decomposition  has  occurred. 

According  to  Lunge  (J.  Soo.  Chem.  Ind.  1886, 
31),  the  solubility  of  calcium  sulphate  in  solutions 
of  sodium  chloride  increases  with  the  per- 
centage of  salt,  but  diminishes  with  increase  of 
temperature. 

At  21*5°,  100  CO.  of  a  3*53  p.c.  solution  of 
NaCl  dissolves  0*5115  gram  CaS04. 

At  18*0°,  100  C.C.  of  a  14*18  p.o.  solution  of 
NaCl  dissolves  0*7340  gram  CaS04. 

At  101*0°,  100  C.C.  of  a  3*53  p.c.  solution  of 
NaCl  dissolves  0*4891  gram  CaS04. 

At  102*5°,  100  C.C.  of  a  14*18  p.c.  solution  of 
Naa  dissolves  0*6248  gram  CaS04. 

Calcium  chloride  diminishes  the  solubility  of 
CaS04  the  more  it  is  concentrated,  but  at  the 
boiling-point  the  concentration  is  immaterial. 
HydrCNohlorio  acid  increases  the  solubility  both 
with  increase  of  concentration  and  of  tempera- 
ture. 

Qypsum  is  readily  soluble  in  excess  of  sodium 
thiosulphate,  formmg  calcium  thioeulphate, 
which  combines  with  the  excess  of  the  sodium 
BflJt  to  form  a  soluble  double  thiosulphate.    On 


addition  of  alcohol,  this  double  salt  separates  a^ 
a  thick  heavv  liquid,  which  solidifies,  forming 
needle-shaped  crystals. 

Both  calcium  and  barium  sulphate  can  bo 
conveniently  and  quantitatively  reduced  at  a 
temperature  of  900°-960°  by  means  of  a  dry 
current  of  carbon  monoxide.  Reduction  com- 
mences at  680°-700°,  becomes  vigorous  at  750*- 
850°,  and  is  practically  finished  at  900°.  The 
reduction  with  carbon  in  an  atmosphere  of 
nitrogen  begins  at  700°,  is  vigorous  at  800°- 
900°,  and  is  complete  at  1000°  (Bull  Amer. 
Inst,  of  Min.  Eng.  1910,  917). 

A  large  experimental  plant  for  utilising,  in 
Germany,  the  dumps  of  calcium  sulphate 
resulting  from  the  neutralisation  of  excess 
sulphuric  acid  in  the  sulphonation  processes, 
consists  in  mixing  the  prenscake  with  coal  and  a 
slagging  material,  presumably  of  the  composi- 
tion required  to  give  a  cement  mixture ;  this  is 
fed  into  a  type  of  rotary  kiln  50  metres  long 
and  3  metres  in  diameter  which  is  coal-durt 
fired.  The  fumes  containing  sulphur  dioxide 
are  cleaned  from  dust  by  electrostatic  means 
(unsatisfactory  at  the  time)  and  are  passed  into 
the  sulphur  trioxide  converters.  The  cement 
produced  from  the  clinker  is  of  satisfactory 
quality.    (J.  Soc.  Chem.  Ind.  287,  1919.) 

Caleiom  lulpbate  eements.  Gjpmm,  hy- 
drated calcium  sulphate  CaS04,2HaO,  is  the 
source  of  this  class  of  cements^  which  depend 
for  this  property  of  setting  on  the  reacquisition 
of  the  water  associated  with  oalcinm  solphate 
in  ^psum. 

The  chemistry  of  calcium  sulphate  cements, 
though  much  the  simplest  of  tnat  concerned 
with  cements  depending  for  their  setting  on 
hydration,  is  of  considerable  difficulty,  and  its 
present  condition  is  far  from  definitive.  Putting 
aside  controversial  views,  the  situation  may  be 
summarised  thus :  When  CaS04,2H,0  is  heated* 
it  loses  water,  and  at  a  temperature  of  about 
107°  becomes  converted  into  the  hemi- 
hydrate  2CaS04,H,0.  When  this  substance  is 
mixed  with  water,  it  is  hydrated,  and  reforms 
CaS04,2H,0,  which  crystalliset  first  in  the 
orthorhomoic,  and  finally  in  the  monoclinio, 
system.  The  quantity  of  water  sufficient  to 
bring  the  hemi-hydrate  baok  to  the  fully  hydrated 
con(ution  is  much  tmaller  than  is  necessary  to 
dissolve  it ;  bnt^  nevertheless,  complete  crystal- 
lisation is  accomplished  thus :  the  hemi-hydrate 
readily  forms  a  supersaturated  solution,  from 
which  not  it  but  the  dihydrate  is  deposited. 
The  water  thus  released  dissolves  another  por- 
tion of  the  hemi-hydrate,  and  the  process  of 
deposition  is  repeated  indefinitely  until,  pro- 
viaed  there  was  originally  enough  water  to 
transform  2CaS04,H,0  into  CaS04,2H,0,  the 
whole  of  the  former  will  have  been  dissolved  in 
detail  and  deposited  in  detail  in  the  shape  of 
the  latter.  As  stated  in  the  section  dealing 
with  Portland  cement,  it  is  believed  that  this 
formation  of  a  supersaturated  solution,  deposi- 
tion of  the  surplus  dissolved  material,  and  re-use 
of  the  water  for  the  solution  of  another  fraction 
<St  the  material  is  general  for  cements  which  set 
when  mixed  with  water,  and,  although  there^  are 
many  gaps  in  the  proof,  yet  the  hypothesis  is 
usefuL  in  the  case  of  calcram  sulphate  cements, 
it  may  be  regarded  as  well  established. 

The  hemi-hydrate  2CaS0,H,0,  constitutes 


pUater  ot  Puia.    It  gfpmm  ii 


appear*  thftt  C&SO,  ci 
modifioktioiw,  whkh    I 


ITIK^ 


It 
.  ^ ,     . .  t  in  two  o»  moro 

modifioktioiw,  whkh  beh>Te  diSsniiitly  with 
water  As  all  eventnallj  become  hjdroted, 
but  not  aJ]  will  aet  u  plosler  of  Paris,  it  ia 
probable  that  only  those  which  will  set  poascaa 
tbe  dutacteriatic  property  oF  fonaing  a  auper- 
catnratisl  solntion,  aod  aJIonriog  the  maae  to 
cryBtallise  in  stages  in  tbe  manner  desciilied 
abore.  Keene's  cement  and  Estrlobgipa  (floor- 
ins  plaster)  are  rzsmplM  ot  cementa  conaiating 
lubstantiallj  of  anhydrous  calcium  aniphsle. 
Tbeii  sotting  is  inflnenoed  b;  both  the  tempera- 
ture at  which  the;  have  been  burnt  and  by 
the  presence  in  tbem  ot  small  qnantitiea  of 
lubstBDce*  other  than  CaSOt,  the  modut 
operandi,  of  which  ia  exceedingly  obscure.  In 
whatever  way  they  are  prepared,  the  final 
product  of  aettinc  ia^«S0,;2H,q. 


ah»lt  o. 

some  conditions  another  halt  at  139°.  There 
is  alao  on  inversion  into  plaster  ol  Paria 
(CaSO,)„H,0  at  107°  and  971  Hg.  presaure, 
though  the  temperature  may  bo  raisecl  to  200° 
without  thia  m version  being  complete.  In 
n^nniLit  practice  the  maximum  temperature 
sd  ia  130°,  in  Engliah  practice  110°-120°, 
a  American  200°  mav  be  reached.  These 
wcee  are  possible  Wauae  of  the  rate 
influence  ot  time  and  temperature  on  the  inver- 
aion  and  the  slowness  with  which  gypsum  and 

? luster  develop  their  true  vapour  pressures, 
he  same  author  considers  there  ia  only  one 
modification  of  oohydrous  calcium  sulphate, 
but  that  ita  properties  vary  with  tbe  degree 
of  agglomeration,  uid  these  with  the  method  of 
formation.  Tbe  setting  of  plaster  may  be 
letorded  by  adding  flooring  plaster,  colloids,  or 
any  subst«noe  which  will  lucreaae  the  aolubility 
of  the  gypsum  and  increased  by  adding  sub- 
•tance*  which  iucceaae  the  solubility. 

The  manufacture  of  plaater  of  Paris  it 
conduct«d  by  heating  tbe  mineral  gypsum  to  a 
temperature  above  that  neoesaary  to  remove 
I  of  its  water  of  crystallisation,  and  below  that 
requisite  to  dehydrate  it  completely.  Several 
method*  ot  burning  are  in  use,  ovena,  kettles, 
and  rotatory  kilos  being  employed.  In  EnKUsh 
practice  a  aunple  oven  ol  the  lund  shown  I  Figs. 
10  and  II)  ia  adopted,  the  gypsum  in  lumps  being 
piled  on  arches  in  which  the  fuel  is  burnt.  In 
the  United  States  the  common  plan  is  to  grind 
the  gypsum  first,  and  heat  it  in  a  large  iron  pot 
or  kettle  set  in  brickwork  and  heated  from 
below.  Tbia  method  is  known  as  '  boiling,' 
owing  to  the  fine  material  being  kept  in  a  state 
of  agitation  by  the  escaping  steam.  During 
the  process  tbe  powdered  material  ia  stirred  by 
an  Bgitat«r  driven  by  power.  A  superior  quality 
of  plBster  is  produced,  but  the  method  is  alow 
and  expensive,  and  is  gradually  being  abandoned 
in  favour  of  the  rotary  calciner. 

In  Scanegatty's  oven  the  interior  is  divided 
by  an  arch  about  a  foot  from  the  floor,  upon  the 
under  side  of  which  play  the  flames  from  a 
tumoee  connected  with  a  lower  chamber,  the 
liot  sir  and  gases  passing  afterwards  through 


apertures    into 
aqueous  vapour  p 
top  of  the  oven. 

Dumesoil's  oven  is  i 


form  which  has  been 


Fia  10. 
the  peculiar  arroDgement  of  the  lower  fire-room, 
whidi  haa  twelve  openings,  the  lower  block*  <rf 
gypsum  being  arranged  so  as  to  facilitate  Um 
circulation  of  the  draught  from  these.  The 
firing  ia  continued  for  about  4  hours,  then  tbe 
heat  is  increased  for  S  hours,  when  all  openingi 
are  closed,  and  5-6  cubio  metres  of  coarse 
gypium  powder  spread  equally  over  the  top  of 
the  burning  sulphate.  By  this  means  conwder- 
able  saving  of  fuel  ia  ejected.  After  standing 
12  hours  to  cool,  the  contents  of  the  kiln  are 
removed.  It  ia  mostly  in  a  state  ot  powder, 
and  Uie  pulverisation  is  completed  Ire  grinding 
in  a  atamp  or  roller  mill  The  powder  ia  then 
sifted  and  stored  iu  a  dry  place. 

Many  improvements  on  tbe  old  forms  have 
been  effected  by  making  the  furnaces  continuous. 


PiQ.    II. 

and  ao  designing  them  that  the  gypsum  ia  eqoallT 
heated,  and,  consequently,  dehydrated  Utrough- 
ouL  This  end  is  also  euamed  by  grinding  the 
gypsum  before  calcination.  The  ttpea  of  ovens 
employed  ore  very  numerous.    Thkt  <rf  Pet»y 


CALCIUM. 


761 


and  Hecking,  Dortmund,  is  a  rotary  kiln,  with 
mill  and  furnace  arranged  aimilarly  to  those  of 
a  cement  works.  The  barrel  oven  of  Perin  of 
Paris  is  a  revolving  cylinder,  supported  upon 
hollow  trunnions,  one  of  which  serves  for  the 
entrance  of  the  heated  gases  from  the  furnace, 
and  the  other  for  exit.  The  chaigine  is  per- 
nformed  from  a  hopper  placed  above  througn  a 
trap-door  in  the  side  of  the  cylinder,  which 
similarly  serves  to  discharge  the  material  when 
burnt.  The  Mannheim  calciner  is  provided 
with  a  pre-heating  chamber,  which  is  placed 
above  the  rotati^  cylindrical  furnace.  The 
crushed  gypeum  is  passed  through  the  former 
by  means  of  a  worm  conveyor  and  then  into  the 
rotating  cylinder,  whilst  the  hot  gases  from  the 
furnace  pass  in  the  opposite  direction.  In 
the  Cummer  rotary  calciner,  which  is  much 
used  in  the  United  States,  the  rotating  cylinder 
is  surrounded  by  a  brick  chamber,  into  which 
the  hot  gasee  first  pass,  and  are  reduced  to  a 
suitable  temperature  by  cold  air  through  inlets 
in  the  walls  oefore  passing  through  the  calciner. 
Other  ovens  are  made  stationary,  but  are  pro- 
vided with  revolving  screws  or  vanes,  which 
serve  to  keep  the  ground  gypsum  in  constant 
motion,  and  also  to  discharge  it  Some  ovens 
are  heated  by  means  of  superheated  steam. 

In  all  cases  the  temperature  must  be  oare- 
fuUy  regulated  so  that  only  the  hemi-hydrate 
is  obtamed.  On  account  of  the  fact  that  a 
considerable  quantity  of  water  has  to  be  driven 
off,  the  temperature  of  the  source  of  heat  may 
be  and  in  practice  is  considerably  higher  than 
107^,  but  the  temperature  of  the  mass  of 
gypsum  must  not  be  allowed  to  rise  above  this, 
test  complete  dehydration  occur. 

Plaster  of  Paris  varies  in  composition  accord- 
ing to  the  purity  of  the  g3rpeum  from  which  it  is 
made.    The  following  analyses  are  illustrative, 
and  for  comparison  the  composition  of  the  hem! 
hydrate  is  appended  : — 


2CaS04,H,0 

Commeroial 

plaiterof 

Paris 

1 

2 

Oalclom  mlidiate  (CaS04)   . 

Water  (HtO) 

Silica  (dlOa) 

Alnmina  and  ferrio  oxide) 

Caiciam  carlwnate  (OaCQa) 
liagnetlum  carbonate(MgCO  ») 

p.e. 

08-8 

6-2 

p.0. 

04*58 

412 

0*67 

p.c. 

88-55 
6-67 
4-27 

(0*47 

(8'07 
1*47 

Keene's  cement  is  nsnaUy  made  in  this 
country  by  first  burning  the  gypsum  to  the  con- 
dition of  plaster  of  Paris,  dipping  the  lumps 
in  a  solution  of  alum  or  of  aluminium  sulphate, 
and  rebumine  at  a  temperature  of  about  600^ 
the  operation  oeing  conducted  in  ovens  in  which 
the  fuel  is  prevented  from  comins  into  contact 
with  the  material,  so  as  to  avoid  discolouration. 
The  following  is  a  typical  analysis  of  Keene*s 
cement  of  good  quality 


6iHca(SiO,)  . 
Alumina  (AljOt) 
Lime(CaO)    . 
Magnesia  (MsO) 
Sulphuric  anhydride  (SO,) 
Carbonic  anhydride  (COt) 


Per  cent, 
trace 
trace 
42-04 
trace 
56*54 
1-37 


It  will  be  seen  that  Keene's  cement  is  almost 
ehemically  pure  CaSOf,  the  quantity  of  added 
matter,  sncn  as  alum,  being  negligible.  As 
mentioned  above,  the  function  of  this  and  similar 
additions  is  obscure,  and  even  the  necessity  for 
their  use  appears  doubtful  because  flooring 
plastei  {Esinchgipa)  is  made  by  burning  pure 
gypsum  at  about  600**,  and,  though  destitute 
of  alum  and  the  like,  sets  welL  MsM^k's  cement 
is  produced  by  addiiig  calcined  sodium  sulphate 
or  potassium  sulphate  to  the  completely  de- 
hydrated gypmuKL  Martin's  cement  is  pre- 
pared like  Keene's,  but  a  solution  of  potassium 
carbonate  replaces  the  alum. 

There  are  many  different  qualities  of  plaster, 
but  all  are  of  the  type  of  plaster  of  Paris,  or  of 
Keene's  cement.  The  former  set  in  a  few 
minutes,  whilst  the  latter  take  several  hours, 
and  as  the  rate  of  setting  of  plaster  of  Paris  is 
inconveniently  rapid  for  some  purposes,  *re- 
tarders,*  consisting  of  such  orsanic  substances 
as  glue,  blood,  and  vegetable  juices,  are  often 
added.  These  substances  of  a  colloidal  nature 
probably  act  by  obstructing  the  growth  of  the 
crystals  of  CaS04,2H^O,  and  uius  delaying 
the  process  of  hydration,  and,  consequently, 
the  setting. 

The  chief  uses  of  plasters  made  from  calcium 
sulphate  are  for  making  castings  or  mouldings  for 
interior  decoration,  for  which  their  white  colour, 
conspicuous  in  the  purer  kinds,  and  their 
expansion  on  setting  and  causing  the  production 
of  sharp  outlines,  peculiarly  adapt  them.  On 
account  of  the  solubility  of  calcium  sulphate  in 
water,  these  plasters  cannot  be  used  for  outdoor 
work.  Minor  uses  are  for  making  moulds  for 
any  material  which  can  be  cast  at  a  sufficiently 
low  temperature,  for  making  surgical  support  for 
broken  limbs,  and,  as  an  addition  to  Portland 
cement,  to  lengthen  its  time  of  setting. 

Add  ealelam  snlphata  CaSO«*H,SO«  is  formed 
by  heating  the  neutral  sulphate  with  strong 
sulphuric  acid  to  SO^'-lOO^  A  portion  of  the 
porous  mass  produced  dissolves  and  separates 
on  coolinff  in  microscopic  prisms  of  the  com- 
position above  indicated.  It  is  decomposed  by 
water,  even  the  moisture  of  the  air,  into  gypeum 
and  sulphuric  acid. 

Calckm-fodiiim  sulphate  CaNat(SO«)a  occurs 
native  in  rhombic  prisms  as  the  mineral  glau' 
herUe,  It  may  be  obtained  in  the  same  form  by 
fusing  together  calcium  and  sodium  sulphates. 
On  heating  50  parts  sodium  sulphate  (Glauber*s 
salt)  with  an  emulsion  of  1  part  gypeum  in  25 
parts  water  to  80'',  crystalline  needles  of 

CaS04-2Na,S04,2H,0 

are  deposited.  On  further  heating,  these  crystals 
are  transformed  into  microscopic  rhombohedral 
crystals  of  slauberite. 

In  the  Welsh  process  of  manufacturing  so- 
dium acetate,  during  evaporation  of  the  liquor 
formed  by  double  decomposition  of  calcium 
acetate  by  sodium  sulphate,  micaceous  spangles 
of  glauberite  have  been  noticed  by  Folkard 
(Chem.  News,  43,  6)  to  separate  out  This 
explains  why  calcium  sulphate  so  tenaciously 
retains  sodium  sulphate. 

Calehim  potassnim  lolphate 

CaSO^KJSO^jH.O 
ooouiB  native  in  monoclinic  ciystab  as  syngenite* 


782 


CALCIUAL 


It.  is  formed  by  mixing  Bolations  of  the  two 
salts.  When  a  mixture  of  equal  weights  of 
anhydrous  calcium  sulphate  and  potassium  sul- 
phate is  stirred  up  with  less  than  its  weight  of 
water,  the  mass  suddenly  solidifies.  If  4-5  parts 
of  water  are  used,  the  solidification  is  not  quite 
so  rapid,  but  gives  casts  superior  to  those  of 
plaster  of  Paris,  inasmuch  as  they  possess  a 
polished  surface. 

A  salt  of  the  composition 

is  obtained  by  adding  an  excess  of  potassium 
sulphate  to  a  warm  concentrated  solution  of 
ammonium  sulphate  which  has  b.een  saturated 
with  calcium  sulphate.  The  same  salt  is  formed 
when  the  double  sulphate  of  calcium  and  po- 
tassium is  treated  with  a  warm  solution  of  am- 
monium sulphate  (Fassbender,  Ber.  11,  1968). 

Calelum  thiosulphate  CaSsO„6HaO  is  pre- 
pared by  heating  an  emulsion  of  calcium  sul- 
phate and  sulphur  in  water.  Divers  (Chem. 
Soc.  Trans.  1884,  270)  obtains  it  by  oxidction 
of  calcium  sulphydrate  in  a  current  of  air, 
calcium  hydroxysulphydrate  being  first  formed 
and  then  oxidised  by  the  SH^  to  thiosulphate 

Ca(SH)OH+20,+H,S=CaS,0,H-2H,0 

It  forms  triclinio  prisms  soluble  in  their  own 
weight  of  cold  water.  On  heating  the  solution 
to  60^,  it  is  decomposed  with  deposition  of 
sulphur.  It  is  usea  for  the  preparation  of 
antimony  cinnabar  Sb|OS«,  used  in  oil  painting. 

Calcium  chromate  CaCr04,4HaO  is  prepared 
by  dissolving  calcium  carbonate  in  aqueous 
chromic  add,  or  as  a  light-yellow  precipitate 
on  mixing  concentrated  solutions  of  cfiucium 
chloride  and  potassium  chromate.  Bouigeois 
(Jahrb.  Min.  1880,  1  Ref.  351)  prepares  the 
anhydrous  salt  by  heating  to  bright  redness  two 
molecules  of  the  chloride  with  a  molecule  of 
potassium  chromate  and  one  of  sodium  carbon- 
ate. It  forms  slender  yellow  needles,  formed 
from  a  rectangular  prism,  moderately  soluble  in 
water,  and  is  used  as  a  pigment.  The  hydrated 
salt  gives  up  its  water  at  200®. 

The  acid  chromate  CaCr^OyfSH^O  is  obtained 
in  red  deliquescent  ciystals  by  evaporating  a  solu- 
tion of  the  neutral  salt  in  aqueous  chromic  acid. 

Caleium  potassium  eluromate  (CaKa)(Cr04)|Aq 
forms  yellow  silky  needles,  obtained  by  satu- 
rating acid  potassium  chromate  with  calcium 
hydroxide. 

Detection  arul  Efttimation  of  Calcium, — ^The 
hydrated  chloride,  when  heated  in  a  non-lumi- 
nous flame  on  platinum  wire,  imparts  to  the 
flame  a  red  colour  of  less  brilliancy  than  stron- 
tium, but  still  very  distinct.  If  the  compound 
to  be  tested  is  decomposed  by  hydrochloric 
acid,  it  IB  only  necessaiy  to  moisten  the  pla- 
tinum wire  with  the  acid,  and  then  dip  it  mto 
the  powdered  substance.  If  the  compound  is 
a  silicate,  it  should  be  powdered  and  mixed 
with  ammonium  fluoride,  gently  heating  on 
platinum  foil  until  the  fluoride  is  volatilisea  ;  it 
is  then  moistened  with  sulphuric  acid  and  tested 
in  the  flame  on  platinum  wire,  when  the  red 


colouration  ia  obtained  aa  soon  as  the  excess  of 
acid  is  driven  off. 

The  spectrum  of  this  red  flame  consists  of  a 
laige  number  of  lines,  of  which  the  green  line 
Cal  is  most  prominent.  Another  characteristic 
line  ia  the  strong  orange  one  Caa.  A  quantity 
of  calcium  chloride  as  little  as  Tin/W  mgm.  may 
be  detected  by  the  spectroscope.  ^  ^ 

All  the  calcium  salts  except  the  sulphate  dis- 
solve readily  in  nitric  or  hydrochloric  acid ;  the 
carbonate,  phosphate,  arsenate,  and  oxalate  are 
insoluble,  the  sulphate  sparingly,  and  almost  all 
the  other  salts  of  calcium  are  readily  soluble  in 
water. 

Ammonium  carbonate  precipitates  calcium 
carbonate  from  solutions  of  calcium  salts,  tiius 
separating  it  from  the  alkali  metals.  In  order 
to  completely  remove  calcium  (the  carbonate 
being  slightly  soluble,  1  part  dissolving  in 
40,000  parts  water),  it  is  usual  to  precipitate  it 
by  means  of  ammonium  oxalate  in  ammoniaoal 
solution,  calcium  oxiUate  beinf^  almost  com- 
pletely insoluble  in  water.  It  is  distingmshed 
from  barium  and  strontium  by  the  greater  solu- 
bility of  its  sulphate,  a  solution  of  calcium  sul- 
phate giving  an  immediate  precipitate  with 
barium  salts,  and  one  after  some  time  with 
soluble  strontium  salts.  Calcium  may  be  dis- 
tinguished from  barium  and  strontium  by  the 
solubilities  of  the  fluorides,  1  litre  of  water 
dissolves  16  mg.  GaF,;  117  mg.  SrF,;  1630 
mg.  BaF*.  Barium  fluoride  is  used  as  the 
reagent.  The  presence  of  SrOl^  or  NH4GI  does 
not  affect  the  reaction,  but  BaCl|  decreases  it. 

Calcium  is  generally  estimated  quantitatively 
as  oxide  or  carbonate  with  intermediate  precipita- 
tion as  oxalate,  by  addition  of  ammoma  till  the 
reaction  is  alkaline,  and  afterwards  of  ammo- 
nium oxalate.  The  washed  and  dried  oxalate 
is  heated  to  low  redness  if  it  is  to  be  converted 
into  carbonate ;  but  if  the  oxide  is  required  it  is 
ignited  over  the  blowpipe  in  a  platinum  crucible. 
If  boric  or  phosphoric  acids  are  present,  this 
method  cannot  be  employed,  and  the  calcium  is 
then  precipitated  as  sulphate  by  adding  dilute 
sulphuric  acid  and  alcohoL  Phosphoric  acid 
may  also  be  flrst  eliminated  by  adding  ferric 
chloride  and  separating  the  iron  and  phosphoric 
acid  by  precipitation  with  ammonia  and  ammo- 
nium acetate.  The  calcium  may  then  be 
estimated  in  the  filtrate  in  the  usual  way. 

The  rapid  estimation  of  lime,  in  technical 
analysis,  is  generally  performed  by  titration  of 
the  oxalate,  after  separation  in  the  usual  way, 
with  standard  permanganate  solution,  at  60^-70% 
in  the  presence  of  sulphuric  acid. 

If  strontium  or  barium  are  present  in  small 
amounts,  the  weighed  calcium  oxide  is  dissolved 
in  nitric  acid,  evaporated  to  dryness,  and  equal 
parts  of  alcohol  and  ether  added.  The  calcium 
nitrate  dissolves  and  barium  and  strontium  fall 
as  a  crystalline  precipitate. 

In  presence  of  much  magnesium  Sonstadt 
(Chem,  News,  29,  209)  recommends  use  of 
potassium  iodate,  which  completely  precipitates 
calcium,  but  not  a  trace  of  magnesium.     0. 8.  B. 


SMD   OF  THB   FIBST   VOLVUE. 


PBINTID  IN  GBEAT  BRITAIN  BT  WILLIAM  OLOWBS  AMD  SONS,  U1[ITB]>,  BBOOLia 


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A  dictionary  of 


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