[ 185  ] 
X.  On  the  Properties  of  Eleetro-deposited  Antimony.  By  G.  Goee,  Esp 
CommiMiicated  hy  Dr.  Tyndall,  F.B.S. 
Received  December  10, — Read  December  10,  1857. 
1.  While  engaged  in  depositing  antimony  by  the  electro-process  in  October  1854,  I 
obserred  a remarkable  phenomenon  of  development  of  heat  in  the  deposited  metal  when 
gently  struck,  and  published  a brief  account  of  it  in  the  Philosophical  Magazine  for 
January  1855  ; since  that  period  I have  investigated  the  phenomenon,  and  have  now  the 
honour  of  laying  the  results  before  the  Eoyal  Society. 
2.  In  depositing  this  metal  by  the  electro-process  several  solutions  may  be  success- 
fully used,  consisting  of  compounds  of  the  metal  either  with  hydrochloric  or  tartaric 
acid ; but  those  I have  generally  operated  with  have  consisted, — 1st,  of  ordinary  chloride 
of  antimony  (as  prepared  for  pharmaceutical  purposes)  nearly  saturated  with  antimony, 
by  suspending  a plate  of  that  metal  in  it  as  an  anode,  and  passing  an  electric  current 
from  several  pairs  of  zinc  and  silver  batteries  through  it  until  a copious  deposit  of 
hj'ight  metal  occurred,  and  until  its  yellow  colour  had  nearly  disappeared ; and  2nd,  of 
five  parts  of  tartar-emetic  and  five  parts  of  tartaric  acid,  dissolved  in  a mixture  of  two 
parts  of  hydrochloric  acid  and  thirty  parts  of  water ; each  solution  being  filtered  before 
using.  A most  excellent  solution  in  lieu  of  the  first  may  quickly  be  formed  by  satu- 
rating ordinary  chloride  of  antimony  with  tartar-emetic,  using  about  three  or  four  parts 
of  the  former  to  one  of  the  latter ; or  by  dissolving  two  parts  of  tartar-emetic  in  three 
parts  of  hydrochloric  acid.  I have  also  in  place  of  that  liquid  occasionally  used  hydro- 
chloric acid  saturated  with  antimony  by  the  battery  process;  and  sometimes  a liquid 
composed  of  seven  parts  of  tartar-emetic  dissolved  in  a mixture  of  eight  parts  of  hydro- 
chloric acid  and  four  parts  of  water.  Substituting  pure  acid,  distilled  water,  and  pure 
antimony,  for  those  of  the  ordinary  quality,  made  no  material  difiierence  in  the  results. 
Each  solution  requires  to  be  electrolysed  a short  time  before  it  yields  a good  and  uniform 
deposit. 
3.  There  are  two  distinct  kinds  of  antimony  deposit  produced  in  these  liquids,  which 
I shall  distinguish  by  the  terms  amorphous  and  crystalline;  dark  and  grey,  for  the 
special  production  of  the  former  I use  the  first  liquid,  or  better  that  composed  of 
chloride  of  antimony  and  tartar-emetic ; and  for  the  latter  I use  the  second : the  first 
solution  will  yield  both  varieties,  but  the  second  gives  the  crystalline  variety  alone. 
The  hne  of  demarcation  between  the  two  kinds  of  deposit  is  rigorously  distinct,  and 
there  appears  to  be  no  transitional  or  intermediate  gradation,  at  least  not  by  this  mode 
of  procedure. 
4.  There  are  a great  many  circumstances  which  influence  the  production  of  those  two 
MDCCCLVIII.  2 c 
