108  Chemistry  of  Ipecacuanha.  { A Varch,  i9hoi!"m' 
EMETINE. 
Emetine  is  apparently  an  amorphous  base  and  almost  colorless.  It 
melts  at  about  68°  C,  is  strongly  alkaline  to  litmus,  and  neutralizes 
acids  completely.  On  exposure  to  light  it  becomes  of  a  yellowish 
color.  It  is  readily  soluble  in  alcohol,  ether,  chloroform  or  ben- 
zine, but  is  only  sparingly  soluble  in  hot  petroleum  spirit  or  in 
water.  On  evaporation  of  any  of  these  solutions  emetine  is  left  in 
the  form  of-  a  transparent  varnish.  Emetine  is  insoluble  in  solu- 
tions of  caustic  alkali,  and  is  thus  distinguishable  from  cephaeline. 
Analysis  of  the  base,  emetine,  which  had  been  prepared  from  the 
crystalline  emetine  hydrochloride  by  precipitation  with  ammonia^ 
gave  the  following  results.  These  results  correspond  very  closely  with 
those  obtained  by  Glenard  and  with  the  formula  C15H22N02  —  248 
or  QoH44N204  =  496. 
i.  2.  Mean.  Theory. 
Carbon  72*23  71*80         72*01  72*58 
Hydrogen  8*71  9*02  8*86  8*87 
Nitrogen  —  5*75  5*75  5*64 
Oxygen  —  —  13*38  12*91 
ioo*  ioo* 
The  platinochloride  was  obtained  as  a  buff-colored  amorphous  pre- 
cipitate, almost  insoluble  in  water  or  alcohol.  It  was  dried  until  con- 
stant at  iOO°  C,  being  partially  decomposed  at  120°  C.  On  analysis 
•208  gramme  gave  -045  gramme  platinum  =  21-63  percent.  Calcu- 
lated for  (C15H22N02)2PtCl42HCl  =  21*53  percent.  Molecular  weight 
of  the  platinum  salt,  905-7. 
On  titrating  emetine  with  hydrochloric  acid  it  was  found  to  require 
for  neutralization  14*56  per  cent.  HC1;  this  result  corresponds 
with  12*71  per  cent,  in  the  hydrochloride,  the  calculated  quantity 
being  12*83  per  cent.,  agreeing  with  the  formula  C15H22N02HC1  or 
C30H44N2O4.2HCl. 
The  saturating  power  of  the  base  is,  of  course,  the  same  whether 
emetine  is  expressed  as  monovalent  C15H22N02  =  248,  according 
to  Glenard,  or  bivalent  with  the  formula  CgoH^N^  =  496,  as  in 
either  case  248  parts  of  emetine  are  equal  to  36*5  parts  HC1  or  496 
parts  to  98  parts  H2S04,  respectively. 
Emetine  hydrochloride  may  be  obtained  in  a  crystalline  form  by 
evaporating  a  water  solution  slowly  or  by  adding  ether  to  an  alco- 
holic solution.    From  water  the  salt  crystallizes  in  radiating  groups 
