Am jJa°nU"i8^arm'}       Assaying  of  Alkaloidal  Drugs.  43 
of  150  gm.  capacity  until  10  drops  of  the  percolate  leave  no  residue 
upon  evaporation,  which  requires  about  100  cc.  ether  and  from  30 
to  90  minutes  according  to  the  fineness  of  the  powder.  (To  deter- 
mine the  amount  of  alkaloid  extracted  in  this  treatment  by  the 
solubility  of  the  alkaloidal  salt  in  the  fixed  oil  solution,  the  ethereal 
solution  was  agitated  with  an  excess  of  hydrochloric  acid,  the 
greater  part  of  the  ether  decanted  and  the  residual  liquid  titrated  with 
Yq-  ammonia  using  iodoeosin  as  indicator  (Am.  Joum,  Pharm., 
1892,  521).  The  rather  remarkable  observation  was  made  in  this 
connection  that  using  the  unpeeled  nux  vomica  about  24  per  cent, 
of  the  total  alkaloid  was  found  in  the  yellow  ethereal  solution  against 
only  7  per  cent,  in  the  case  of  peeled  nux  vomica  yielding  a  color- 
less filtrate  ;  the  fat  averaging  3-1  5  per  cent.  The  extraction  tube  is 
next  placed  on  a  dry,  tared  vial  of  250  gm.  capacity,  the  cotton  plug 
pushed  into  the  vial  and  the  drug  washed  in  with  ether  adding  of 
the  latter  to  make  up  to  roo  gm.;  after  adding  50  gm.  chloroform 
and  thoroughly  agitating  10  cc.  ammonia  water  (10  per  cent.)  are 
added  and  the  mixture  shaken  repeatedly  during  half  an  hour.  In 
the  meantime  the  ethereal  fat  solution  is  agitated  with  5  cc.  ^~ 
hydrochloric  acid  and  10  cc.  water,  pouring  off  the  ether  as  far  as 
practicable  and  securing  a  complete  separation  by  the  use  of  a  sepa- 
rating funnel  which  is  then  washed  with  several  portions  of  water 
so  that  the  acid  solution  and  washings  measure  25  cc.  This  acid 
liquid  is  added  to  the  mixture  in  the  vial,  shaking  for  several  min- 
utes, and  after  the  separation  into  two  layers  1 00  gm.  of  the  ether- 
chloroform  solution  are  poured  (if  necessary  through  a  small  filter 
moistened  with  the  solvent)  into  a  tared  Erlenmeyer  flask  and  the 
solvent  distilled  off.  The  alkaloids  remain  as  a  colorless  varnish 
which  is  freed  with  difficulty  from  the  chloroform  by  heat,  but  which 
can  be  easily  effected  by  covering  the  alkaloids  several  times  with 
small  quantities  of  alcohol  which  is  then  boiled  away  in  a  water-bath  ; 
the  alkaloids  during  these  operations  become  crystalline  and  can  be 
dried  to  constant  weight  at  a  temperature  not  exceeding  95-1000  C. 
The  alkaloids  can  then  be  titrated  by  dissolving  in  5  cc.  chloroform 
with  the  aid  of  a  little  heat,  adding  40  cc.  ether,  10  cc.  water,  one 
drop  of  an  alcoholic  iodoeosin  solution  (one  per  cent.)  and  10  cc. 
hydrochloric  acid  ;  after  agitation  the  excess  of  acid  is  titrated  with 
-jSj-  ammonia  until  a  permanent  red  color  appears  in  the  aqueous 
solution  ;  after  each  addition  of  ammonia  the  flask  must  be  corked 
