"^'"Airll^s^s!''"''}  Chemical  Examination  of  Cincho-^inine.  1 5 1 
4'559  grams,  and  had  therefore  lost  0-441  grams  =—  8*82  per  cent.  [See 
results  ^4.) 
Quantitative  result  No.  2. — Amount  of  substances  f  oreign  to  an  alkaloidal 
condition  of  cincho-quinine  8*820  per  cent. 
A  3. — The  filtrates  and  washings  from  A  2  were  mixed,  evaporated 
to  a  small  volume,  acidulated  with  hydrochloric  acid,  and  chloride  ot 
barium  added,  in  slight  excess.  The  precipitate  which  had  formed 
was  collected  on  a  filter,  washed,  dried  and  weighed.  The  so  obtained 
sulphate  of  barium  weighed  0'6()^  grams  ;  corresponding  to  0*240  grams 
of  sulphuric  acid  =  4*8  per  cent.,  SO3. 
Quantitative  result  No.  3. — Cincho-quinine  contains  of  sulphuric  acid 
4*8oo  per  cent. 
A  4. — The  filtrate  and  washings  from  A  3  were  concentrated  to  a 
small  bulk,  sulphuric  acid  added  in  slight  excess,  to  remove  the  excess 
of  barium  used  as  chloride,  the  sulphate  of  barium  was  filtered  off,  and 
to  the  clear  filtrate  ammonia  was  added  in  slight  excess.  No  precipitate 
of  alkaloids  was  formed  after  standing  for  more  than  a  week. 
Result  No.  4. —  The  washings  from  the  precipitated  alkaloids.,  A  2,  did 
not  hold  alkaloids  in  solution. 
Remarks. — By  these  experiments,  ^,  we  have  shown,  that  the 
sample  of  cincho-quinine  (No.  2),  contained  8*820  per  cent,  of  con- 
stituents which  are  foreign  to  its  alkaloidal  condition.  Of  this  quan- 
tity, sulphuric  acid  constitutes  a  portion  equal  to  4*80  per  cent,  of  the 
cincho-quinine,  and  water,  driven  off  by  the  heat  of  the  water-bath, 
1*262  per  cent.,  leaving  2*758  per  cent,  to  be  accounted  for.  Our 
qualitative  experiments  have  shown  the  presence  of  a  small  quantity  of 
ammonia  as  sulphate,  and  of  a  considerable  quantity  of  sulphate  of  the 
alkaloids ;  and,  further  on,  we  propose  to  show  the  exact  quantities  of 
these  sulphates,  obtainable  by  a  given  quantity  of  water  from  each  of 
the  four  samples  of  cincho-quinine  examined.  We  have  also  found 
that  the  filtrates  and  washings  from  the  precipitated  alkaloids,  did  not 
contain  any  alkaloids  in  solution  (-^4),  and  therefore,  unhesitatingly 
account  for  the  2*758  per  cent,  of  foreign  matter,  as  ammonia  and 
water  of  crystallization  in  the  alkaloidal  sulphates. 
RECAPITULATION   OF   RESULTS  A. 
Per  cent. 
1.  Amount  of  sulphuric  acid  in  cincho-quinine,      .....  4-800 
2.  "  of  moisture  expelled  by  heating  to  i8o°-2oo°  F.,  .  .  1-262 
-z.  "  of  ammonia,  |  ^ 
4.                 of  water  of  crystallization  in  alkaloidal  sulphate,    j      *        •      ^  75 
Total  constituents  foreign  to  an  alkaloidal  condition  of  cincho-quinine,  8*820 
