^'^'a^^aIS^s'^'^'} Chemical  Examination  of  Cincho-^inine.  149 
Qualitative  result  No.  6. — Cincho-quinine  contains  cinchonia  in  its  alka- 
loidal  condition. 
A  fourth  and  weighed  portion  of  cincho-quinine  was  dissolved  in 
dilute  sulphuric  acid,  precipitated  with  ammonia,  digested  with  ether, 
and  the  ethereal  solution  evaporated  and  weighed  ;  our  aim  being  to 
ascertain  the  proportion  of,  in  ether,  soluble  alkaloids,  which  amounted 
to  4'75  per  cent,  of  the  cincho-quinine  employed.  We  wish  it  to  be 
understood,  however,  that  this  experiment  was  not  conducted  with  the 
degree  of  care  required  for  a  quantitative  experiment,  the  result  as 
obtained  being  sufficiently  accurate  for  a  qualitative  experiment,  as  was 
intended. 
Qualitative  result  No.  7. — Cincho-quinine  contains  but  a  small  relative 
proportion  of  in  ether soluble  alkaloids. 
The  ethereal  residue,  as  above  obtained,  was  found  to  contain  either 
quinia  or  quinidia,  or  both.  We  dissolved  a  portion  in  dilute  alcohol, 
containing  5  per  cent,  sulphuric  acid,  added  tincture  of  iodine,  and  re- 
dissolved  the  bulky  brown  precipitate  produced,  by  the  aid  of  gentle 
heat.  After  standing  24  hours,  the  deposit  which  had  formed  was  ex- 
amined, and  was  found  to  consist  mainly  of  brown  iodo-sulphate  of 
quinidia,  interspersed  with  the  characteristic  green-black  crystals  of 
herapathit  (iodo-sulphate  of  quinia). 
Qualitative  result  No.  8.  —  Cincho-quinine  contains  both  quinia  and 
quinidia.,  but  the  relative  proportion  of  quinia  to  quinidia  is  very  small. 
By  these  qualitative  experiments  we  have  proven  : 
1.  That  cincho-quinine  contains  sulphuric  acid. 
2.  That  this  sulphuric  acid  is  partly  represented  by  sulphate  of  am- 
monium. 
3.  That  the  greater  part  of  the  sulphuric  acid  is  represented  by 
alkaloidal  sulphate. 
4.  That  cincho-quinine  contains  but  a  small  percentage  of  quinia, 
either  as  alkaloid  or  as  sulphate. 
5.  That  the  entire  quantity  of,  in  ether,  soluble  alkaloids  contained 
in  cincho-quinine  does  not  exceed  5  per  cent.,  and  that  the  bulk  of  the, 
in  ether,  soluble  alkaloid  is  composed  of  quinidia  (present  in  the  cincho- 
quinine,  either  as  alkaloid  or  sulphate). 
6.  That  cincho-quinine  is  mainly  composed  of  cinchonia,  partly  as 
alkaloid  and  partly  as  sulphate. 
7.  That,  therefore,  cincho-quinine  is  not  a  fair  nor  accurate  alka- 
loidal  representative  of  cinchona  bark. 
