THE  AMERICAN 
JOURNAL  OF  PHARMACY. 
DECEMBER,  1882. 
ON  BISMUTH  SUBNITRATE. 
By  Simon  E.  Wolf,  Ph.G.i 
Having  learned  that  in  a  post-mortem  examination  bismuth "siibni- 
trate  had  been  found  in  the  stomach  in  an  unchanged  state,  except  that 
the  particles  had  become  covered  with  a  thin  coating  of  bismuth  sul- 
phide^ several  commercial  samples  of  the  subnitrate  were  examined 
microscopically  and  found  to  be,  some  of  them  distinctly  crystalline, 
others  amorphous.  This  induced  an  inquiry  into  the  conditions  under 
which  bismuth  subnitrate  may  be  obtained  in  different  forms;  the 
results  show  that  the  precipitation  of  the  salt  is  influenced  by  the  tem- 
perature, the  amount  of  the  precipitating  liquid,  the  manner  in  which 
the  latter  is  added,  and  by  its  composition.  It  appears  that  analogous 
salts,  especially  the  nitrates,  interfere  with  the  precipitation  of  the  sub- 
nitrate and  enable  solutions  of  bismuth  nitrate  to  be  diluted  with  much 
larger  volumes  of  water  than  when  these  salts  are  absent.  For  all  the 
experiments  the  same  solution  was  used,  prepared  by  dissolving  30  gm. 
of  bismuth  subnitrate  in  30  cc.  of  nitric  acid  with  the  aid  of  heat,  and 
adding  sufficient  distilled  water  to  make  the  solution  measure  150 
cubic  centimeters. 
Effects  of  Temperature. — The  precipitating  liquid  was  heated  to 
100°C.,  and  2  cc.  of  the  solution  added  to  it,  when — 
1.  With  10  cc.  of  distilled  water  distinct  prismatic  crystals  were 
obtained. 
2.  With  80  cc.  of  water  the  precipitate  was  amorphous. 
3.  With  40  cc.  of  water  acidulated  with  hydrochloric  acid  (quan- 
tity?) no  precipitate  was  produced. 
1  The  author,  who  graduated  from  the  Philadelphia  College  of  Pharmacy 
in  March,  died  at  Harrisburg,  Pa.,  May  29,  1882.  The  above  essay  is  a 
brief  abstract,  prepared  from  his  graduating  thesis,  which  contains  eight 
carefully  executed  microscopic  drawings  from  which  a  selection  for  the 
accompanying  wood  cut  has  been  made.  -Editor  Am.  Jour.  Piiarm. 
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