ON"  THE  CHEMICAL  CONSTITUENTS  OF  COCA  LEAVES.  497 
vestigations  was  to  search  for  an  alkaloid,  whicli  he  separated  in 
a  pure  state  and  analyzed.  The  wax  and  tannin  were  separated 
incidentally  in  the  process  for  liberating  the  alkaloid,  so  that  we 
are  still  in  the  dark  about  its  other  constituents. 
A  few  months  ago,  I  obtained  through  the  kindness  of  Pro- 
fessor Procter,  a  few  ounces  of  coca  leaves  for  the  purpose  of 
analyzing  them.  I  should  have  desired  very  much  to  pay  at- 
tention likewise  to  those  constituents  which  are  probably  of  less 
importance  in  regard  to  their  medical  properties,  but  at  all  events 
I  had  to  follow  the  course  marked  out  by  Dr.  Niemann,  so  as  not 
to  lose  the  opportunity  of  obtaining  a  little  of  the  new  alkaloid, 
and  study  the  other  substances  isolated  by  him. 
Accordingly,  1500  grains  of  the  coarsely  powdered  leaves  were 
exhausted  in  a  funnel-displacer  by  alcohol  mixed  with  a  little 
sulphuric  acid.  The  dark  colored  brown-green  tincture  was 
agitated  with  an  excess  of  milk  of  lime,  which  assumed  a 
brownish-green  color  ;  the  filtrate  therefrom,  together  with  the 
washings  with  cold  alcohol,  was  carefully  neutralized  with  sul- 
phuric acid,  filtered  from  the  greenish  sulphate  of  lime  and 
distilled.  The  aqueous  residue  separated  but  little  resinous 
matter,  the  filtrate  therefrom  was  precipitated  by  carbonate  of 
soda  and  the  alkaloid  gained  in  an  impure  state  by  shaking  the 
mixture  with  ether  and  evaporating  the  light  straw-colored  ethe- 
real solution.  The  yield  was  4  grains,  and  the  alkaloid  showed 
the  behaviour  described  on  pages  123  and  124. 
On  adding  the  milk  of  lime  to  the  acid  tincture,  the  peculiar 
tea-like  odor  of  the  leaves  was  strongly  developed  ;  but  on  the  ad- 
dition of  the  carbonate  of  soda  another  heavy  and  narcotic 
odor  is  observed  ;  this  is  described  by  Maclagan  and  Niemann  as 
reminding  of  nicotina.  I  observed  this  slight  resemblance,  but 
still  the  odor  is  very  difi*erent, 
I  likewise  found  Dr.  Niemann's  statements  correct  regarding 
the  vegetable  wax  and  the  tannin  ;  though,  owing  to  the  small 
quantity  operated  on,  I  was  unable  to  obtain  the  former  in  a 
snow-white  condition.  The  second  acid,  which  Niemann  considers 
as  tannin  modified  by  nitric  acid,  I  obtained  also  in  solution 
contaminated  with  some  of  the  latter  acid. 
The  alkaloids  of  coffee  and  cacao,  which,  though  in  a  less 
degree,  possess  properties  similar  to  those  of  coca,  contain. 
32 
