Am.  Jour.  Pharm.  \ 
Feb..  1893.  ) 
A  Ikaloidal  A ssaying. 
8i 
the  high  specific  gravity  of  the  chloroform  allowing  a  film  or  layer 
of  amorphous  alkaloid  to  form  on  the  surface,  which  then  prevents 
the  escape  of  the  remainder  of  the  chloroform  ;  the  last  portions  of 
the  chloroform  can  be  gotten  rid  of  by  dissolving  the  residue  in  5 
or  10  cc.  ether  and  evaporating  the  ether  at  the  temperature  of 
the  water-bath ;  by  repeating  the  operation  only  traces  of  the 
chloroform  will  remain,  and  drying  at  90-IOO0  C.  is  facilitated 
by  the  amorphous  alkaloid  becoming  crystalline.  The  titration  of 
the  alkaloidal  residue  is  effected  readily  by  dissolving  in  alcohol, 
adding  water  until  a  faint  turbidity  results  and  titrating  with  the 
acid;  haematoxylin  (1  per  cent.)  in  alcoholic  solution  gives  after  a 
little  practice  the  best  results  as  an  indicator,  care  being  taken 
to  add  only  one  or  two  drops  of  the  solution,  otherwise  difficulty 
is  encountered  in  determining  the  end  reaction. 
Assay  of  the  fluid  extract  of  ipecac. — 8  grams  of  the  fluid  extract 
are  diluted  with  8  grams  water  in  an  ordinary  vial,  32  grams  chloro- 
form and  48  grams  ether  added  and  thoroughly  agitated  ;  4  grams 
water  of  ammonia  are  next  added  and  the  mixture  frequently 
agitated  during  half  an  hour.  After  separation  50  grams  of  the 
chloroform-ether  solution  representing  5  grams  of  the  extract  are 
poured  or  filtered  into  a  tared  flask  and  the  solvent  distilled  off ; 
the  varnish-like  residue  is  twice  treated  with  5-10  cc.  ether  and 
evaporated  by  forcing  a  current  of  air  into  the  flask  by  means  of  a 
rubber  bulb  ;  after  the  last  traces  of  ether  have  been  removed  and 
the  residue  dried  in  a  water-bath  it  is  weighed.  For  the  titration 
the  alkaloid  is  dissolved  with  the  aid  of  heat  in  10  cc.  absolute  alcohol 
and  sufficient  water  added  to  give  a  permanent  turbidity ;  after 
adding  one  or  two  drops  haematoxylin  solution  ^  ^-hydrochloric 
acid  is  added  until  the  violet-red  color  changes  to  a  pure  pale-yellow. 
Emetine,  according  to  Kunz,  is  di-acid  and  has  the  formula  CgoH^ 
N2Os,  mol.  weight  508  (by  a  control  experiment  with  pure  emetine 
this  formula  was  found  to  be  correct  ;  the  older  formula  C20H30N2O5, 
however,  is  still  to  be  found  in  some  recent  standard  works), the  equiv- 
alent weight,  therefore,  is  254  and  I  cc.y1^-  ^-hydrochloric  acid  repre- 
sents 0  0254  grams  emetine.  In  various  samples  of  fluid  extract  of 
ipecac  made  from  the  same  drug  by  different  methods  2-54-2-59  per 
cent,  emetine  was  found. 
The  statement,  recently  published  by  Caesar  &  Loretz  (Am.  Jour. 
Pharm.  1892,  568),  that  the  best  selected  ipecac  root  yielded  at  the 
