SULPHATE  OF  QUINIA. 
Mr.  Wm.  Procter,  Jr. 
Dear  Sir — Our  attention  having  been  called  to  an  article  on  Citrate 
of  Iron  and  Quinia,  for  the  forthcoming  number  of  the  Journal,  we 
have  been  politely  favored  by  the  author  with  a  proof-copy.  As  there 
are  some  inaccuracies  in  this  article,  we  beg  to  state  that  we  have  re- 
peated the  process  described  in  precipitating  the  Quinia,  with  different 
results. 
We  used,  in  making  these  trials,  87.5  grains  of  Crystallized  Sulphate 
of  Quinia  in  two,  and  100  grains  in  a  third;  from  all  we  obtained  the 
full  calculated  quantity  of  Quinia,  viz.:  from  the  first  two,  65  grains 
each,  and  from  the  last,  74.5  grains.  We  cannot  account  for  the 
author's  failure  to  obtain  proper  results,  in  any  other  way  than  by  sup- 
posing that  too  much  of  the  precipitant  was  used  (thereby  redissolving 
the  precipitate,)  and  subsequent  excessive  washing,  or  else  the  oppo- 
site, by  not  precipitating  the  whole  of  the  alkaloid  from  an  insufficiency 
of  Ammonia,  both  of  which  are  points  of  importance. 
There  is  another  singular  inference,  which  to  us  is  mysterious,  that 
the  effloresced  salt  contains  10  per  cent,  of  uncombined  water.  If  this 
could  be  so,  why  was  not  the  water  dissipated  during  the  exposure  of 
drying? 
To  verify  the  results  named  we  also  submitted  100  grains  of  the 
crystallized  Sulphate  used  in  making  these  trials  to  an  exposure  in  warm 
dry  air,  and  obtained  87.5  grains  of  effloresced  Sulphate  from  it,  which 
is  as  close  an  approximation  to  the  calculated  weight,  87.61,  as  our 
scales  would  indicate. 
As  these  errors  may  be  of  grave  importance  to  our  business,  we  beg 
the  favor  of  an  insertion  in  the  same  Journal,  or  if  too  late,  permission 
for  the  binder  to  attach  as  a  separate  page. 
Very  respectfully  your  friends, 
POWEKS  &  WEIGHTMAN. 
Philadelphia,  June  25,  1855. 
