EXAMINATION  OF  THE  SULPHATE  OF  QUINIA. 
395 
has  found  that  a  solution  of  cane  sugar  kept  for  some  time, 
experiences  the  same  conversion  into  uncrystallizable  sugar  as 
when  heated  with  acids.  The  sugar  in  these  two  preparations 
was  exactly  in  a  condition  to  undergo  this  change  in  solution, 
and  had  been  kept  for  some  time,  and  at  the  commencement  no 
free  acid  was  present,  but  by  the  metamorphosis  free  acid  was 
probably  generated  arid  accelerated  the  change.  To  obviate  this 
difficulty  in  the  above  and  like  preparations,  I  would  suggest 
the  propriety  of  using  grape  sugar  as  a  protective  agent ;  it 
could  be  easily  made  from  starch,  and  would  be  as  economical, 
and  not  change  or  deposit  by  the  action  of  acids  as  cane  sugar 
will. 
Cincinnati,  August,  1855. 
EXAMINATION  OF  THE   SULPHATE  OF  QUINIA  OF  MESSRS. 
POWERS  &  WEIGHTMAN,  OF  PHILADELPHIA. 
By  Edward  R.  Squibb,  M.  D.,  U.  S.  Navy. 
Assistant  Director  U.  S.  Naval  Laboratory,  New  York. 
Mr.  Wm.  Procter,  Jr. 
Bear  Sir:- — In  the  last  number  of  the  Journal  there  appears 
by  the  side  of  my  paper  on  citrate  of  iron  anlf  quinia,  a  note  to 
you  from  Messrs.  Powers  &  Weightman,  characterizing  a  part, 
at  least,  of  that  paper  as  inaccurate.  Now  my  remarks  upon 
their  sulphate  of  quinia  did  not  pretend  to  more  than  the  accu- 
racy of  ordinary  practical  pharmacy;  and  the  aim  was  to  attain 
constancy  and  certainty  in  connection  with  the  subject  of  the 
paper,  and  to  forestall  any  inferences  as  to  whose  sulphate  of 
quinia  it  was  that  gave  so  short  a  yield.  The  amount  (10  per 
cent.)  of  uncombined  water  stated  to  be  in  this  sulphate,  I  now 
know  to  be  technically  incorrect.  But  it  was  judged  of  by  the 
loss  in  partially  efflorescing  at  212°,  in  comparison  with  the 
statements  of  the  majority  of  authorities  at  hand,  and  by  an 
inference  of  its  purity.  This  latter  inference  was  also  both 
technically  and  practically  incorrect. 
The  pecuniary  sensibilities  of  the  manufacturers  appe'ar  to  have 
led  them  to  receive  these  remarks  upon  their  preparation  as  a 
critical  analysis,  and  they  contradict  the  results,  and  substitute 
for  them  others,  which,  as  chemical  analyses,  to  establish  the 
