Am.  Jour.  Pharm. 
Aug. ,  1886.  ' 
Commercial  Sulphate  of  Quinine. 
389 
ON  COMMERCIAL  SULPHATE  OF  QUININE. 
The  purity  of  commercial  sulphate  of  quinine  has  been  the  subject 
of  a  number  of  communications  to  European  journals.  One  of  these 
papers  has  been  republished  on  p.  243  of  the  present  volume  of  this 
Journal.  Dr.  O.  Hesse  (Phar.  Jour,  and  Trans.,  March  27,  1886) 
shows  that  the  commercial  salt  containing  a  moderate  amount  of  cin- 
chonidine  sulphate,  can  be  deprived  of  this  impurity  by  two  re-crys- 
tallizations from  boiling  water.  On  further  re-crystallization,  no 
alteration  should  take  place  in  the  rotatory  power,  which  for  absolutely 
pure  quinine  sulphate,  was  ascertained  to  be  [a]  D— — 233.75°.  It 
is  also  shown  that  from  moderately  concentrated  solutions  the  quinine 
sulphate  crystallizes  together  with  the  cinchonidine  sulphate  in  mas- 
sive brilliant  needles,  which  may  be  regarded  as  an  actual  double  salt. 
Cinchonidine  hydrochlorate  crystallizes  from  concentrated  solutions 
in  needles  with  2  H20,  and  from  dilute  solutions  in  octohedrons  with 
1  H20 ;  but  when  mixed  with  a  preponderating  amount  of  quinine 
hydrochlorate  (which  crystallizes  only  in  needles  with  2  H20),  the  two 
salts  crystallize  in  needles  with  2  H20,  not  separately,  but  in  all  pro- 
portions together. 
Dr.  J.  E.  De  Yrij  (The  Chemist  and  Druggist,  May  1, 1886)  observed 
in  1883  that  quinine  sulphate  tested  in  Hesse's  quinometer  (see  Am. 
Jour.  Phar.,  1879,  p.  136)  would  invariably  yield  crystals  of  cin- 
chonidine if  the  ethereal  liquid  was  kept  for  12  or  14  days;  and  he 
recommended  (Nieuw  Tijdschr.,  1884,  p.  10)  as  the  best  practical 
means  for  obtaining  pure  quinine  sulphate,  that  it  be  prepared  from 
the  acid  sulphate,  which  never  contains  cinchonidine.  Dr.  De  Vrifs 
assertion  that  no  commercial  quinine  sulphate  containing  less  than  5 
per  cent,  of  cinchonidine  sulphate  was  to  be  met  with,  was  based  upon 
a  number  of  assays,  one  of  which,  made  since,  is  described,  and  con- 
sists in  converting  the  salt  into  the  acid  sulphate,  precipitating  the 
mother  liquid  with  soda,  converting  these  alkaloids  into  tartrate,  and 
submitting  to  the  optical  test  (Oudemans,  1875,  1877).  This  method 
showed  the  sample  to  contain  7.41  per  cent,  cinchonidine  sulphate, 
and  is  stated  to  afford  approximate  results  only,  while  accurate  results 
(9.46  cinchonidine  sulphate  in  the  same  sample)  are  stated  to  be  ob- 
tained by  mixing  a  hot  solution  of  quinine  sulphate  with  a  hot  solution 
of  an  equal  weight  of  sodium  tartrate,  drying  the  precipitated  tartrate 
below  30°  C,  and  dissolving  1  gm.  of  this  salt  in  7.5  ccm.  of  normal 
