ARSENITE  OF  STRYCHNIA. 
353 
ARSENITE  OF  STRYCHNIA. 
By  M.  F.  Ceresoli,  of  Paris. 
This  salt  appears  to  have  been  first  examined  therapeutically 
by  Prof.  Grimelli,  for  whom  it  was  prepared  by  M.  Chiappero,  of 
Turin,  who  made  it  by  neutralizing  a  solution  of  arsenious  acid 
in  diluted  muriatic  acid  with  strychnia.  In  this  way  the  salt 
contained  muriate  of  strychnia.  To  avoid  this  result  the  author 
sought  a  process  by  double  decomposition,  based  on  the  fact  that 
sulphate  of  potassa  is  insoluble  in  alcohol  whilst  arsenite  of 
strychnia  is  readily  dissolved  by  this  liquid  of  86  per  cent.  The 
following  is  the  process  : 
Take  of  Caustic  potassa,       .       .       3*12  grammes. 
Arsenious  acid,        .       .       3*30  " 
Distilled  water,        .       .      60-00  " 
Sulphuric  acid,         .       .       2-65  " 
Crystallized  strychnia,      .      12*00  " 
Dissolve  the  caustic  potassa  in  40  grammes  of  the  water  heated 
to  ebullition,  add  the  arsenious  acid  and  form  a  solution.  Then 
dilute  the  sulphuric  acid  with  20  grammes  of  distilled  water,  heat 
to  ebullition  and  add  the  strychnia,  so  as  to  form  a  complete  so- 
lution.   The  two  solutions  are  then  mixed  at  the  temperature  of 
204°  F.,  adding  the  arsenite  of  potassa  to  the  sulphate  of  strych- 
nia.   A  magma  of  crystals  of  sulphate  of  potassa  and  arsenite  of 
strychnia  is  thus  produced.    Heat  causes  the  latter  salt  to  dis- 
solve when  the  solution  is  filtered  from  the  undissolved  portion 
of  sulphate  of  potassa,  and  is  then  evaporated  nearly  to  dryness. 
The  saline  mass  thus  obtained  is  treated  with  alcohol,  which 
separates  the  remainder  of  the  sulphate  of  potassa.    The  alco- 
holic solution  is  then  allowed  to  evaporate  till  crystallization 
occurs,  which  is  in  about  two  days. 
Arsenite  of  strychnia  crystallizes  in  cubes  of  a  dead  white ;  it 
contains  water  which  is  lost  by  exposure  to  the  air.  Heat  de- 
composes it  completely,  and  leaves  for  a  residue  a  black  and 
porous  charcoal.  The  odor  by  the  action  of  heat  is  at  first  em- 
pyreumatic,  followed  by  dense  white  vapors  and  the  odor  of 
garlic.  Its  taste  i3  bitter  and  metallic.  It  is  without  action  on 
polarized  light,  soluble  in  alcohol,  less  soluble  in  ether,  and  solu- 
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