Am.  Jour.  Pharm.  \ 
August,  1887.  / 
Quinine  Testing. 
405 
what  lighter  form,  but  not  of  such  a  light  flocculeut  character  as  the 
sulphate  usually  prepared  and  answering  to  the  test  of  the  German 
Pharmacopoeia.  The  light  character  of  the  latter  is,  therefore,  due  to 
some  other  circumstance,  and  especially  to  the  presence  of  small 
admixtures  of  the  sulphates  of  hydroquinine  and  cinchonidine,  possi- 
bly also  of  hydrocinchonidine  and  homocinchonidine.  The  sulphates 
belonging  to  the  cinchonidine  group  can  be  separated  from  quinine 
sulphate  without  interfering  with  its  light  form  when  it  happens  that 
there  is  a  sufficient  amount  of  hydroquinine  present. 
Quinine  sulphate  does  not  assume  the  light  character  in  question 
as  a  result  of  the  presence  of  quinidine  or  cinchonine  sulphates ;  more- 
over, it  has  not  the  least  tendency  to  crystallize  together  with  either 
of  these  salts.  It  is  true,  Jungfleisch  states  that  quinine  sulphate 
made  from  cuprea  bark  contains  quinidine,  which  separates  in  crystals 
when  such  quinine  sulphate  is  subjected  to  my  test,  but  so  far  as  my 
observation  goes  this  statement  is  not  supported  by  experiment. 
Leaving  out  of  consideration  for  the  moment  hydroquinine — which, 
as  I  shall  show  in  a  subsequent  paper,  approximates  very  closely 
indeed  to  quinine  in  its  chemical  nature—as  well  as  the  traces  of 
hydrocinchonidine  and  homocinchonidine  that  are  now  and  then  met 
with  in  normal  quinine  sulphate,  cinchonidine  is  the  only  adventitious 
alkaloid  that  has  to  be  taken  into  account  as  being  not  unfrequently 
present  in  large  amount  in  the  bark  from  which  quinine  sulphate  is 
manufactured.  The  Ceylon  bark,  which  is  now  so  abundant  in  the 
market,  is  for  the  most  part  especially  rich  in  this  alkaloid.  But 
notwithstanding  this  disadvantage,  it  is  still  the  case  that  in  the  old- 
established  quinine  factories  quinine  sulphate  that  contains  only  a 
very  small  amount  of  cinchonidine  sulphate  is  made  from  this  bark. 
It  may  indeed  be  safely  assumed  that  formerly,  when  the  method 
of  manufacture  was  less  perfect  than  it  is  at  present,  quinine  sulphate 
contained  a  much  larger  proportion  of  cinchonidine,  although  the 
bark  then  employed  for  the  purpose  generally  contained  a  smaller 
amount  of  cinchonidine  than  at  the  present  time.  But  even  then  the 
amount  of  cinchonidine  was  limited  by  the  prescribed  method  of  test- 
ing. So  far  as  I  am  aware,  Liebig's  test  was  then  most  in  use,  and, 
as  I  have  shown  in  another  place,  it  indicates  the  presence  of  cinchoni- 
dine only  when  amounting  to  more  than  10  per  cent.  I,  therefore, 
consider  it  very  probable — and  in  this  respect  I  agree  fully  with 
DeVrij's  opinion — that  in  his  time  the  therapeutic  value  of  quinine 
