114  Commercial  Sulphate  of  Strychnine.  | 
f  Am.  Jour.  Pharm. 
Mar..  188:i 
acidulated  with  hydrochloric  acid,  precipitated  by  baric  chloride, 
filtered,  the  precipitate  well  washed,  dried,  ignited,  and  weighed. 
I.  1*8094  gm.  of  anhydrous  strychnine  sulphate  gave  0'5641  gm. 
of  baric  sulphate,  corresponding  to  13"106  per  cent,  of  H2SO4,  as  seen 
by  the  following  equation  : 
BaSO,:H2S04::  0-5641:  X  or 
233  :  98::  0-5641 : 0-23725  or  amount  of  H^SO,  present. 
Then  1-8094:0-23725::  100:x  or  13-106  per  cent.  H2SO,. 
II.  1*7883  gm.  of  No.  2,  gave  0*5503  gm.  of  baric  sulphate,  corres- 
ponding to  12*941  per  cent,  of  H.^SO^,  as  seen  by  the  equation  : 
BaSO, :  H.SO^::  0-5503  :x  or 
233  :       98::  0-5503: 0-23145  or  amount  of  H2SO4  present. 
Then  1-7883:0-23145::  100: x  or  12-941  percent,  of  H.SO,  present. 
On  calculating  the  percentage  of  II2SO4  in  a  neutral  and  acid  sul- 
phate of  strychnine,  the. following  result  is  obtained: 
Calculated.  Found. 
(C2iH22N202)2H2SO,.       (C2iH2,N202)H2SO,.       No.  1.  No.  2. 
H2SO,  12-793  per  cent.    22-685  per  cent.       13-106  per  cent.    12.941  per  cent. 
On  comparing  these  results,  it  is  at  once  evident  that  sulphate  of 
strychnine  of  the  American  manufacturers  is  a  neutral  salt,  having  the 
formula  (C2iH22]SrA)2H2S04. 
The  next  step  was  to  determine  the  amount  of  water  of  crystalliza- 
tion. According  to  Rammelsberg,  the  salt  of  German  commerce,  in 
addition  to  being  an  acid  sulphate,  contains  but  two  molecules  of  water, 
while  a  neutral  salt  prepared  therefrom  contains  five  molecules  (when 
crystallized  from  a  hot  solution)  or  six  molecules  when  obtained  by  the 
slow  evaporation  of  the  solution.  For  this  determination,  I  re-crystall- 
ized a  portion  of  the  two  salts,  so  as  to  avoid  any  error  through  efflo- 
rescence. Having  obtained  the  salts  in  fine  crystals,  they  were  care- 
fully dried  upon  bibulous  paper,  and  portions  of  each  were  subjected 
to  a  temperature,  gradually  increased  to  185°C.,  until  they  ceased  to 
loose  weight.  I.  0*8885  gm.  of  the  salt  lost  by  heating,  0*1075  gm., 
corresponding  to  12*099  per  cent,  of  water  of  crystallization. 
II.  0*9709  gm.  of  the  salt  lost  by  heating  0*1241  gm.,  corresponding 
to  12*503  per  cent,  of  water  of  crystallization.  In  calculating  the  per- 
centage of  water  in  a  salt,  containing  six  molecules  HgO,  and  also  one 
containing  seven  molecules  H2O,  the  following  result  is  obtained: 
