Am.  Jour.  Pharm.  \ 
September,  1911.  j 
The  Fixation  of  Sulphide. 
413 
ments  in  order  to  determine  if  there  were  any  chemical  basis  for 
such  a  difference,  in  other  words,  whether  the  various  basic  bismuth 
salts  really  differ  in  their  behavior  tow^ard  sulphides. 
In  the  first  series  of  experiments  the  sulphides  were  applied 
directly  to  suspensions  of  bismuth  salts  (0.5  gm.  with  water  q.s.  — 25 
cc).  The  reaction  of  the  suspension  to  litmus  paper  was  noted, 
through  one  set  of  samples  a  current  of  HgSwas  passed  to  saturation. 
To  the  other  Ammonium  Sulphide  (NH4)oS  sol  (5  cc.)  was  added. 
Suspensions 
Reaction 
H2S 
(NHO2S 
Bismuth  Magma  (dried)  old  
Bismuth  Magma  (dried)  new .... 
Bismuth  Subcarbonate   
Bismuth  Subnitrate  
Bismuth  Subsalicylate  
Neutral 
Neutral 
Neutral 
Neutral 
Neutral 
Neutral 
Positive 
Positive 
Positive 
Positive 
Positive 
Positive 
Positive 
Positive 
Positive 
Positive 
Positive 
Positive 
Two  samples  of  finished  Creams  of  Bismuth,  one  made  by  the  N.  F. 
process,  the  other  by  Raubenheimer's  modification,  were  tested  with 
(NH^)oS;  both  gave  dark  ash  colored  ppts. 
It  will  be  seen  that  the  sulphide  is  formed  in  all,  but  somewhat 
less  readily  in  the  old  magma. 
A  second  series  of  experiments  was  made  to  determine  whether 
any  bismuth  goes  into  sol.  in  water.  0.5  gm.  of  the  Bisimith  subsalt 
in  water  q.s.  25  cc.  was  allowed  to  stand  24-48  hrs.,  frequently 
agitated,  filtered  and  filtrate  brought  up  to  25  cc.  These  filtrates  were 
tested  the  same  as  the  first  series. 
Filtrates 
Reaction 
H2S 
(NH4)2S 
Bismuth  Magma  (dried)  old  
Bismuth  Magma  (dried)  new  
Bismuth  Subcarbonate  
Bismuth  Subgallate  
Bismuth  Subnitrate  
Bismuth  Subsalicylate  
Neutral 
Neutral 
Neutral 
Neutral 
Neutral 
Neutral 
Negative 
Negative 
Negative 
Positive 
Positive 
Negative 

Negative 
Negative 
Negative 
Positive 
Positive 
Negative 
Conclusions . — The  suspensions  of  the  various  basic  bismuth  salts 
are  practically,  equally  effective  in  binding  H^S  but  in  old  magma 
this  property  is  impaired. 
Water  left  in  contact  with  the  basic  bismuth  salts  dissolves 
some  bismuth  from  the  subnitrate  and  subgallate  but  none  from  the 
others. 
