320 
Some  Commercial  Cocoas. 
Aid.  Jour.  Pharm. 
June,  1895. 
Nos  I  and  7,  led  to  a  further  examination  as  to  their  solubilities 
in  water  and  acid. 
The  water-soluble  portion  was  obtained  by  treating  the  ash  with 
water,  filtering,  evaporating  filtrate  and  then  carefully  heating  the 
residue.  The  portion  insoluble  in  water  Was  then  treated  with 
dilute  hydrochloric  acid  and  the  insoluble  residue  carefully  washed, 
dried  and  heated  to  redness. 
It  was  found  that  in  those  samples  having  a  high  per  cent,  of  ash, 
the  proportion  soluble  in  water  was  two  or  three  times  larger  than 
in  those  brands  having  a  lower  per  cent,  of  inorganic  constituents. 
The  fat  was  determined  in  the  following  manner  :  5  grammes  of 
the  powder  were  placed  in  a  test  tube  and  agitated  with  a  conve- 
nient quantity  of  petroleum  ether  and  allowed  to  settle,  when  the 
clear  liquid  was  separated ;  this  was  repeated  four  or  five  times,  or 
until  all  of  the  fat  was  removed.  The  petroleum  ether  was  allowed 
to  evaporate  spontaneously,  and  the  fat  so  obtained  placed  in  a  desic- 
cator to  deprive  it  of  moisture.  The  melting  point  was  then  ascer- 
tained by  simply  exposing  this  residue  contained  in  a  beaker  to  the 
temperature  of  a  water-bath.  The  melting  points,  so  ascertained  of 
the  several  samples,  were  found  not  to  vary  much,  the  range  being 
from  370  C.  to  400  C.  This,  together  with  the  general  appearance, 
was  thought  to  indicate  the  genuine  character  of  the  fat  contained 
in  these  brands. 
The  residue  left  after  the  extraction  of  the  fat  was  exhausted  with 
hot  alcohol,  sp.  gr.  o  850,  and  this  extract,  while  still  warm,  treated 
with  basic  lead  acetate,  to  precipitate  tannates,  tartrates,  etc.  The 
filtrate  was  then  evaporated,  the  residue  taken  up  with  chloroform, 
the  mixture  filtered,  and  the  residue  obtained  upon  evaporation  to 
dryness  weighed  as  theobromine. 
That  part  of  the  sample  undissolved  by  the  treatment  with  hot 
alcohol  was  treated  with  cold  water  until  the  filtrate  was  nearly  free 
from  color,  and  the  aqueous  solution  so  obtained  wras  evaporated  to 
dryness  and  weighed  as  extractive. 
The  portion  undissolved  by  the  foregoing  solvent  was  dried  at 
ioo°  C.  and  calculated  as  starch,  fibre,  etc. 
For  the  determination  of  starch  100  mg.  of  this  residue  were 
gently  boiled  for  two  hours  with  50  c.c.  distilled  water  acidulated 
with  2  per  cent,  of  dilute  sulphuric  acid  in  a  250  c.c.  flask,  the  water 
lost  by  evaporation  being  replaced  from  time  to  time.    After  filter- 
