Am.  Jour.  Pharm. 
July,  1892. 
Assay  of  Nitx  Vomica. 
353 
present  itself.  It  is  seen  that  each  assay  gave  a  higher  average 
than  the  manufacturer  had  established,  and  every  precaution  was 
taken  to  reduce  the  residues  to  constant  weight.  That  the  maker 
slightly  under-estimated  (preferring  probably  to  understate  rather 
than  overdraw)  its  alkaloidal  value  seems  therefore  evident  from 
this  series  of  investigations,  which  were  partly  experimental  and  not 
designed  to  establish  the  highest  possible  results,  and  to  which  may 
be  added  the  product  with  specimen  A  (Table  IX),  in  which  the 
alkaloidal  percentage  was  2-56  per  cent.  The  average  percentage, 
as  shown  by  five  assays,  was  2-53  per  cent.  The  difference  (0-17 
per  cent.)  between  this  amount  and  the  valuation  stated  by  the 
manufacturer  being  closer  than  might  be  expected,  considering  that 
the  details  of  methods  may  have  been  different,  and  the  conditions 
of  residue  exposure  such  as  to  lead  to  unavoidable  variations. 
(11)  Time  Consumed  in  the  Assay. — (A)  The  abstraction  of  the 
iron  magma  by  means  of  the  mechanical  mixer  requires  five  minutes. 
(B)  The  evaporation  of  the  chloroform,  if  a  deep  beaker  is  used, 
and  a  steam  or  water-bath,  will  be  nearly  accomplished  during  the 
abstraction  of  the  magma  A.  The  several  portions  of  chloroform 
should  be  decanted  into  the  beaker  successively  and  the  two  opera- 
tions (A  and  B)  may  be  completed  in  ten  minutes. 
(C)  The  washing  of  the  fatty  residue  and  filtration  of  the  acid 
solutions  will  take  about  ten  minutes.1 
(D)  The  rotations  of  the  aqueous  solution  of  the  alkaloid  with 
chloroform  require  ten  minutes. 
(is)  The  evaporation  of  the  alkaloidal  chloroform  in  a  deep 
beaker  on  a  water  or  steam-bath  should  be  accomplished  in  a  couple 
of  minutes  after  the  last  chloroform  (D)  has  been  abstracted  from 
the  rotator,  for  these  two  operations  should  progress  simultaneously, 
one  portion  of  chloroform  being  evaporated  while  the  succeeding 
rotation  is  being  made. 
(i7)  The  final  exposure  of  the  residue,  in  my  opinion,  if  the 
temperature  ranges  from  I400  F.  to  1 75 0  F.,  should  not  require 
more  than  fifteen  minutes  to  bring  it  to  a  brittle  glass-like  condition 
when  cold.    Total,  forty-five  minutes. 
1  If,  as  seems  to  me  desirable,  one  portion  of  chloroform  (15  cc.)  be  used  to 
abstract  the  iron  magma  A,  and  one  portion  of  15  cc.  to  rotate  the  aqueous 
solution  D,  the  time  will  be  much  reduced. 
