306      COMPARATIVE  EXAMINATION  OF  IPECACUANHAS,  ETC. 
But  whilst  druggists  appear  to  be  satisfied  with  the  new  Ipe- 
cac from  its  physical  characters,  pharmaceutists  have  had  some 
hesitation  to  adopt  it  in  the  absence  of  direct  analysis  and  thera- 
peutic trials,  and  it  was  with  the  motive  of  settling  by  analysis 
the  real  character  of  this  Ipecac  that  the  author  undertook  this 
paper. 
1.  Pelletier  and  M,  Dumas,  tracing  for  the  first  time  the 
chemical  history  of  emetia,  remarked  that  this  alkaloid  produces 
a  very  insoluble  tannate ;  this  reaction  has  been  used  to  deter- 
loine  the  proportion  of  emetia  contained  in  each  of  the  commer- 
cial varieties. 
A  certain  weight  of  powdered  Ipecac  dried  at  212°  was  ex- 
hausted, first,  with  warm  alcohol,  and  then  with  diluted  alcohol, 
the  solutions  united  and  evaporated  to  a  syrupy  consistence. 
The  residue  was  treated  with  fifteen  to  twenty  times  its  weight 
of  water,  the  solution  filtered  and  a  slight  excess  of  tannin  added, 
which  caused  an  abundant  precipitate  of  tannate  of  emetia. 
This  precipitate,  collected  on  a  tared  filter,  was  washed,  afld 
dried  in  a  stove.  This  process  unites  great  precision  with  readi- 
ness of  execution,  and  has  enabled  us  to  discover  that  New 
Grenada  Ipecac  is  always  a  little  less  rich  in  emetia  than  that 
of  Brazil. 
The  following  results  were  obtained  in  operating  on  ten  gram- 
mes (154  grains)  of  the  powder  of  each  kind,  deprived  of  the 
woody  portion : 
Ipecacuanha  of  Brazil.  Tannate  of  Emetia o 
First  experiment       100  grammes  yielded  1*441  grammes. 
Second      "  100       "  "     1458  " 
Ipecacuanha  of  New  Grenada. 
First  experiment       100  grammes  yielded  1-380  grammes. 
Second       "  100       "  "  1-302 
•2.  In  studying  the  chemical  properties  of  emetia  M.  Lefort 
has  discovered  that  its  nitrate  enjoys  the  rare  property  of  being 
but  little  soluble  in  water,  so  that  an  aqueous  solution  of  acetate 
of  emetia  is  precipitated  voluminously  by  nitrate  of  potassa, 
which  precipitate  agglutinates  into  a  brown  extract  like  mass 
very  soluble  in  alcohol. 
The  author  tried  this  reaction  as  an  assay,  operating  on  an 
