404  EXAMINATION  OF  THE  SULPHATE  OF  QUINIA. 
21.44  per  cent,  of  water  of  crystallization  present,  and  the  per- 
centage composition  of  the  salt  appears  to  be  as  follows : 
Base      -       -       69.1  per  cent. 
S03        -       -        9.457  « 
HO        -      -       21.442    «     by  deduction. 
99.999 
Hence  it  follows  as  a  deduction,  that  the  base  cannot  be  quinia 
alone,  unless  it  was  in  the  form  of  neutral  sulphate. 
The  red  brown  amorphous  matter  I  have  not  examined,  except 
to  determine  by  chlorine,  water  and  ammonia  that  there  was 
only  a  trace  of  quinia  in  it. 
These,  then,  are  the  experiments  and  results  of  the  examina- 
tion as  far  as  I  have  time  to  carry  them  out ;  and  I  am  sorry 
that  other  occupations  prevent  me  from  pursuing  so  important 
and  interesting  a  subject  to  something  like  completion.  The 
deductions  from  these  results  I  leave  to  those  who  read  and  ex- 
amine them,  merely  remarking  that  the  experiments  were  prose- 
cuted far  enough  to  make  it  quite  clear  to  my  mind,  that  al- 
though there  is  not  10  per  cent.,  nor  perhaps  even  quite  5  per 
cent.,  of  uncombined  water  in  this  commercial  salt,  there  is  more 
than  10  per  cent,  of  water  and  other  impurities,  two-thirds  of 
which,  at  least,  might  and  should  be  avoided  in  the  manufacture 
of  medicinal  preparations. 
Naval  Laboratory,  New  York,  Aug.  8th,  1855. 
LETTER  FROM  MESSRS.  POWERS  AND  WEIGHTMAN  RELATIVE 
TO  THEIR  SULPHATE  OF  QUINIA. 
Mr.  W.  Procter,  Jr. 
Bear  Sir, — Though  the  politeness  of  Dr.  Squibb  we  are  again 
put  in  possession  of  the  proof  sheets  of  a  communication  by  him, 
in  reply  to  a  note  of  ours  in  the  last  number  of  the  Journal,  on 
the  subject  of  sulphate  of  quinia.  Our  former  communication 
was  necessarily  brief,  and  the  results  of  our  experiments  therein 
detailed  were  not  numerous,  nor  were  they  conducted  through  any 
protracted  period,  and  might  not  therefore  be  looked  upon  as 
conclusive  as  those,  detailed  by  the  Doctor. 
Since  then,  however,  we  have  had  more  experiments  made  on 
