Chemical  Examination  of  Cincho-^inine.  1 55 
also  wished  to  determine  the  amounts  of,  in  ether,  soluble  alkaloids 
contained  in  samples  No.  i.  No.  3,  and  No.  4,  and  to  determine  the 
amount  of  quinia  in  one  or  more  of  these  samples. 
EXPERIMENTS  D. 
D  I. — 2*0  grams  of  each  of  the  samples  of  cincho-quinine,  No.  i, 
No.  2,  No.  3,  and  No.  4,  were  tested  as  follows  :  The  sample  was 
triturated  to  a  fine  powder,  and  agitated  in  a  flask,  occasionally,  for  24 
hours  with  60  grams  of  water  ;  the  contents  of  the  flask  were  then 
poured  on  a  filter,  and  the  residue  on  the  filter  washed  with  sufficient 
water  to  make  the  weight  of  the  filtrate  up  to  60  grams.  The  filtrate 
was  evaporated  in  a  tared  capsule  and  heated  until  it  no  longer  lost 
weight,  at  a  temperature  of  about  i8o°F.  The  following  table  shows 
our  results  : 
2  GRAMS  CINCHO-QUININE. 
WEIGHT   OF  RESIDUE 
FROM 
AQUEOUS  SOLUTION. 
PERCENTAGE 
Sample  No.  i. 
0*255  grams. 
12.75  per  cent. 
Sample  No.  2. 
0-235  grams. 
11-75  per  cent. 
Sample  No.  3. 
0*350  grams. 
17*70  per  cent. 
Sample  No.  4. 
0*44.0  grams. 
22*00  per  cent. 
These  residues  consisted  mainly  of  short,  prismatic  crystals,  and  were 
perfectly  white.  We  subjected  the  residue  from  sample  No.  4  to  the 
following  qualitative  examination: 
D  2. — The  residue  (from  sample  No.  4)  was  digested  with  30  grams 
of  cold  water  for  24  hours,  and  the  solution  was  then  filtered  from  the 
undissolved  portion.     The  solution=^.     The  undissolved  portion^/*. 
a.  The  solution  (a)  was  found  to  contain  sulphuric  acid,  by  the  usual 
test.  Upon  the  addition  of  ammonia,  an  abundant  alkaloidal  precip- 
itate was  produced.  The  addition  of  chlorine  water,  followed  by  am- 
monia, gave  no  color  reaction. 
Result  of  a. — The  cold  aqueous  solution  is  composed  of  sulphate 
of  cinchonia  (and,  perhaps,  sulphate  of  cinchonidia). 
b.  The  undissolved  portion  /»,  was  dissolved  in  a  little  water  by  the 
aid  of  hydrochloric  acid.  The  solution  gave  abundant  evidence  of 
sulphuric  acid  and  of  alkaloid,  by  the  tests  heretofore  used.     It  gave  a 
