Am.  Jour.  Phar  in.  \ 
March,  1889.  / 
Processes  for  Testing  Quinine. 
147 
chonidine  found)  must  be  applied.  The  author  gives  a  curve  for  the 
purpose.  The  cinchonidine  is  very  nearly  pure.  The  hydro-bases  are 
determined  approximately  by  oxidizing  the  quinine  and  cinchonidine 
in  acid  solution  by  a  1  per  cent,  solution  of  potassium  permanganate, 
rendering  alkaline,  and  shaking  with  ether,  followed  by  chloroform. 
The  residues  from  these  solutions,  although  very  impure,  are  regarded 
as  hydroquinine. 
The  "  chromate  process"  was  recommended  by  Dr.  De  Vrij  (see 
Amer.  Jour.  Phar.,  1887,  p.  343),  and  the  "oxalate  test"  by  Dr. 
L.Schaefer  (see  Amer.  Jour.  Phar.,  1887,  p.  153).  The  amount  of 
oxalate  prescribed  is  insufficient  for  samples  containing  less  than 
15  per  cent,  of  water,  and  the  cooling  at  20°  should  be  prolonged  to 
one  hour.  Schaefer's  correction  of  0*04  gram  per  100  cc.  appears  to 
be  too  large. 
In  Hesse's  "  bisulphate  process "  5  grams  of  quinine  sulphate  is 
dissolved  in  12  cc.  of  normal  sulphuric  acid  by  warming,  and  the  so- 
lution is  allowed  to  crystallize  in  a  narrow-necked  funnel  in  a  cold 
place.  The  mother-liquor  is  withdrawn  by  a  filter-pump  into  a  grad- 
uated cylinder,  and  the  crystals  washed  with  three  cc.  of  water.  This 
solution  is  shaken  with  16  cc.  of  ether  (0*721 — 0'728),  then  3  cc. 
of  ammonia  (0*96)  added,  again  shaken,  and  left  for  24  hours.  The 
ether  is  removed  by  a  pipette,  the  crystals  are  collected  on  a  filter, 
washed  with  water  saturated  with  ether,  dried  between  filter-paper, 
washed  again  with  ether,  and  dried.  # 
In  the  "  crystallization  process "  of  Paul  and  Hesse,  5  grams  of 
quinine  sulphate  is  dissolved  in  boiling  water,  and  crystallized  out 
four  times,  using  in  the  first  case  150  cc,  next  130  cc,  and  then 
twice  120  cc.  The  united  mother-liquors  are  evaporated  at  a  low 
temperature  almost  to  dryness,  the  residue  dissolved  in  the  smallest 
possible  quantity  of  dilute  sulphuric  acid,  made  up  to  20  cc,  and 
shaken  with  ether  and  excess  of  ammonia.  The  crystals  which  form 
are  treated  as  in  the  bisulphate  test.  The  hydro-bases  crystallize  in 
part  with  the  quinine,  therefore  the  mother-liquor  should  not  be  used 
for  their  determination. 
The  chromate  process  gives  very  varying  results,  but  on  the  aver- 
age gives  the  highest  yield  of  cinchonidine,  especially  with  the  purer 
samples.  The  oxalate  test  gives  the  lowest  numbers,  but  they  are 
more  concordant  than  those  of  the  chromate  process.  The  composi- 
tion of  the  bye-product  is,  however,  variable.    The  bisulphate  test 
