390 
Commercial  Sulphate  of  Quinine. 
Am.  Jour.  Pharm. 
Aug.,  1886. 
hydrochloric  acid  and  sufficient  water  to  measure  50  ccm.  at  17°  C. ; 
this  solution  is  tested  in  Laurent's  polariscope  in  a  tube  0.5  m.  in 
length.  Two  commercial  samples  of  English  manufacture  were  thus 
found  to  contain  5.723  and  10.850  of  water,  and  9.508  and  6.942  of 
cinchonidine  sulphate  ;  two  of  French  manufacture,  14.646  and  13.762 
water,  and  9.072  and  12.448  cinchonidine  salt ;  five  of  German  manu- 
facture, between  12.426  and  17.842  water,  and  between  4.730  and 
8.180  cinchonidine  salt,  and  one  of  Dutch  manufacture,  13.714  water 
and  8.355  cinchonidine  salt,  while  a  sample  made  at  Amsterdam  from 
the  acid  sulphate  contained  12.425  water  of  crystallization  and  was 
free  from  cinchonidine. 
Dr.  O.  Hesse  (Phar.  Jour,  and  Trans.,  June  5,  1886)  states  that 
the  rotatory  power  of  quinine  sulphate  on  being  heated  to  120°  C.  is 
not  augmented,  but  undergoes  a  minute  reduction,  as  he  showed  in 
1876  (Liebig's  Annalen,  vol.  182,  p.  154),  and  criticises  the  different 
results  obtained  by  Dr.  De  Vrij  with  the  same  sample  of  quinine  salt 
by  means  of  the  optical  method  By  this  method,  however,  cinchoni- 
dine can  be  most  accurately  determined  in  the  presence  of  quinine  in 
the  absence  of  hydroquinine,  which  is  usually  present  in  commercial 
quinine  sulphate.  In  1882,  Dr.  Hesse  published  a  note  on  hydroqui- 
nine (see  Am.  Jour.  Phar.,  1882,  p.  363),  and  a  more  extended  me- 
moir will  shortly  be  published.  This  alkaloid  which  is  associated 
with  quinine  in  cinchona  bark,  is  a  saturated  compound  while  quinine 
is  not.  Its  neutral  sulphate  crystallizes  with  8  H20,  sometimes  with 
6  H20;  the  anhydrous  salt  requires  at  15°  C.  348  parts  of  water  for 
solution,  and  although  5  ccm.  of  this  liquid  require  25  ccm.  of  am- 
monia, sp.  gr.  "960,  for  the  complete  solution  of  the  alkaloid,  it  can- 
not be  detected  in  quinine  sulphate  by  the  pharmacopoeia!  test.  The 
twTo  sulphates  form  a  compound  crystallizing  in  long  delicate  needles, 
and  hydroquinine  cannot  be  separated  completely  except  by  converting 
quinine  sulphate  into  the  acid  salt,  and  recrystallizing  this  from  water 
or  alcohol,  when  hydroquinine  remains  in  the  mother  liquors.  Its  tar- 
trate is  almost  as  sparingly  soluble  as  quinine  tartrate. 
As  a  therapeutic  agent  hydroquinine  is  of  the  same  kind  as  quinine 
sulphate.  But  when  the  optical  method  of  testing  is  applied  to  such 
a  salt,  the  hydroquinine  sulphate  present  in  it  produces  an  effect  simi- 
lating  that  of  cinchonidine  sulphate  in  the  proportion  of  1  :  0*42, 
and  it  is  in  this  way  that  the  optical  method  of  testing  leads  to  a  re- 
sult that  is  incorrectly  unfavorable  so  far  as  relates  to  the  amount  of 
