J34 
Cinchona  Alkaloids. 
1  Am.  Jour.  Pharm. 
\      Mar.,  1879. 
for  by  the  fact  that  the  above  sulphates,  when  mixed,  sometimes  have 
different  actions  than  when  separated. 
The  method  in  question  does  not  indicate,  according  to  my  experi- 
ments when  using  solutions  of  1  in  10,  an  admixture  of  to  per  cent, 
sulphate  of  cinchonia  in  sulphate  of  quinidia,  or  vice  versa,  as  needles 
arranged  in  stellate  groups  are  produced,  which  may  belong  to  either 
alkaloid.  More  satisfactory,  however,  is  the  result  if  the  presence  of 
sulphate  of  cinchonidia  or  homo-cinchonidia  is  to  be  detected  in  the 
alkaloids  deviating  to  the  right.  If,  for  instance,  sulphate  of  cinchonia 
containing  10  per  cent,  of  sulphate  of  cinchonidia  or  homo-cincho- 
nidia is  used,  it  will  be  observed  that  first  much  sulphocyanide  of  cin- 
chonia is  separated  in  single  crystals  and  dendritic  groups  of  prisms, 
and  then  delicate  needles,  concentrically  grouped,  representing  cincho- 
nidia or  homo-cinchonidia.  If,  however,  either  of  the  latter  sulphates 
is  present  in  cinchonia  sulphate  in  smaller  proportions  than  5  per  cent, 
it  will  not  be  indicated.  The  test  also  fails  when  quinia  is  present  in 
cinchonia  sulphate  or  quinia  in  quinidia  sulphate.  In  the  latter  case 
the  only  indication  of  the  presence  of  quinia  might  be  that  then  the 
sulphocyanide  of  quinidia  is  partly  separated  in  wart-like  aggregations. 
But  a  small  amount  of  cinchonidia  or  homo-cinchonidia  produces  a 
similar  effect.  If  3  per  cent,  of  the  latter  sulphates  are  present  in  sul- 
phate of  quinidia  the  wart-like  and  dendritic  groups  of  sulphocyanide 
of  quinidia  will  first  separate,  and  afterwards  dense  stellate  crystals- 
belonging  to  the  sulphocyanides  of  the  left  rotating  alkaloids. 
As  for  testing  sulphate  of  quinia  qualitatively  by  this  method,  its 
difficult  solubility  in  cold  water  may  be  taken  advantage  of.  The 
microscopic  determination  is  especially  sensitive  in  discerning  ar* 
admixture  of  quinidia  and  cinchonia.  If  1  per  cent,  sulphate  of 
quinidia  is  present  in  quinia  wart-like  crystal  clusters  of  sulphocyanide 
of  quinidia,  and  later,  several  groups  of  the  crystals  of  sulphocyanide 
of  quinia  will  be  formed.  If  2  per  cent,  is  present,  the  dendritic  forms 
of  sulphocyanide  of  quinidia  will  immediately  be  noticed.  If  sulphate 
of  quinia  contains  1  per  cent,  sulphate  of  cinchonia  isolated  prisms, 
some  of  them  curved,  will  immediately  be  obtained,  then  a  few  stellate 
groups,  and  at  last  the  characteristic  groups  of  quinia  are  formed. 
Entirely  different  will  be  the  result,  however,  if  the  sulphates  of  cincho- 
nidia and  homo-cinchonidia  are  present  in  quinia.  From  the  results  with 
the  pure  sulphates,  an  abundant  formation  of  crystals  was  anticipated  if 
