CONSTITUENTS  OF  COCA  LEAVES. 
123 
Wackenroder,  Johnston,  Gaedcke,  and  Maclagan,  and  states  that 
the  alkaloid  prepared  by  Pizzi  of  La  Paz,  and  brought  by  Tschudi 
to  Europe,  was  analyzed  by  him  and  found  to  be  gypsum. 
The  following  is  the  author's  process  for  preparing  the  alka- 
loid which  he  proposes  to  name  cocaina.  The  leaves  are  ex- 
hausted with  86  per  ct.  alcohol  containing  sulphuric  acid,  the 
tincture  treated  with  milk  of  lime,  the  filtrate  neutralized  with 
sulphuric  acid,  and  the  alcohol  regained  from  the  filtrate  by 
distillation.  The  syrupy  residue  is  treated  with  water  to  sepa- 
rate resin,  the  liquid  is  precipitated  by  carbonate  of  soda,  when 
an  odor  reminding  of  nicotia  is  emitted^  and  the  alkaloid  is  ex- 
hausted by  repeated  agitation  with  ether,  distilling  off  most  of 
the  ether,  and  evaporating  the  balance  spontaneously.  The  yield 
is  about  \  per  ct.  of  crude  cocaina,  consisting  of  colorless  crys- 
tals mechanically  mixed  with  a  yellowish  brown  matter  of  a 
disagreeable  almost  narcotic  odor,  which  cannot  be  removed  by 
animal  charcoal  or  recrystallization,  but  may  be  separated  by 
washing  with  cold  alcohol.  Less  loss  is  sustained  if  the  ethereal 
solution  is  agitated  with  diluted  sulphuric  acid,  the  aqueous  so- 
lution of  the  sulphate  precipitated  by  carbonate  of  soda  and  the 
precipitate  freed  from  the  last  traces  of  coloring  matter  by  alco- 
hol. The  alkaloid  crystallizes  best  on  evaporating  spontaneous- 
ly an  alcoholic  solution  previously  diluted  with  water. 
Pure  cocaina  is  in  colorless  transparent,  rather  large  prisms, 
inodorous,  soluble  in  704  parts  water  at  12^  C.  (SS.G'^  F.),  more 
in  alcohol,  freely  in  ether.  The  solutions  have  an  alkaline  re- 
action, a  bitterish  taste,  promote  the  flow  of  the  saliva,  and  leave 
upon  the  tongue  a  peculiar  numbness,  followed  by  a  sensation 
of  cold.  The  crystals  fuse  at  98^  C.  (208^  F.)  and  congeal  again 
to  a  transparent  mass, which  gradually  assumes  a  crystalline  struc- 
ture. Heated  above  its  fusing  point,  it  becomes  colored,  and  is 
decomposed;  it  runs  up  the  sides  of  the  vessel,  and  it  is  uncer- 
tain yet  whether  a  small  portion  will  sublime  unaltered.  It 
fuses  upon  platinum  foil,  and  burns  with  a  bright  flame,  leaving 
a  charcoal,  burning  with  some  difficulty. 
No  physiological  experiments  have  as  yet  been  made  with  it. 
The  alkaloid  is  readily  soluble  in  all  diluted  acids,  forming  salts 
which  are  of  a  more  intensely  bitter  taste  than  uncombined  co- 
caina.   It  absorbs  dry  hydrochloric  acid  gas,  fuses  and  congeals 
