ADecimberP!19i71'  ^    Decomposition  of  Quinine  Bisulphate.  593 
of  8o°  C,  but  no  mention  of  decomposition.  "  Brit.  Pharm.  Codex. 
1907"  states  that  the  salt  softens  at  60 0  C,  is  semi-fluid  at  700  C, 
melts  at  about  1600  C,  with  decomposition,  being  converted  into 
acid  quinicine  sulphate.  It  is  curious  to  observe  that  the  P.B.  is 
one  of  very  few  official  Pharmacopoeias  which  fail  to  include  this 
highly  important  salt.  It  should  also  be  noted  that  in  all  the  au- 
thorities above  quoted  the  lowest  temperature  mentioned  at  which 
decomposition  occurs  is  1200  C.  The  present  authors  consider  that 
the  uncertainty  with  regard  to  the  actual  temperature  of  decomposi- 
tion is  highly  unsatisfactory  and  actually  misleading,  as  it  might 
be  presumed  that  no  decomposition  would  take  place  at  any  tem- 
perature below  those  limits  mentioned  in  the  authorities  stated 
above.  This,  however,  is  not  the  case,  and  it  has  been  found  that 
decomposition  will  occur  at  very  moderate  temperatures,  and  under 
conditions  which  might  be  used  (unless  warning  was  given)  in  the 
preparation  of  a  solution  of  the  bisulphate  for  hypodermic  injection. 
The  "U.  S.  P.  IX,"  p.  616,  in  describing  "sterilization,"  recom- 
mends the  heating  of  the  solution  to  115  —  1200  C.  The  steriliza- 
tion of  a  10  per  cent,  solution  of  the  salt  at  this  temperature  for 
thirty  minutes  actually  caused  5  per  cent,  of  the  alkaloid  to  be 
decomposed  into  quinicine.  A  large  number  of  experiments  have 
been  carried  out  with  the  salt  to  ascertain  the  dangerous  tempera- 
ture at  which  decomposition  would  occur.  In  each  case  the  amount 
of  decomposition  was  ascertained  by  separating;  the  unchanged 
quinine  from  the  quinicine  in  the  following  manner : 
The  mass,  after  being  submitted  to  a  constant  heat  for  twenty- 
four  hours,  was  dissolved,  the  boiling  solution  neutralized*  with 
ammonia,  and  the  unchanged  quinine  sulphate  crystallized  out  on 
cooling.  This  was  filtered,  dried  and  weighed.  The  quinine  re- 
maining in  the  mother  liquor  was  obtained  as  tartrate  by  the  addi- 
tion of  sodium  potassium  tartrate  to  the  filtrate.  The  small  amount 
of  tartrate  so  obtained  was  weighed ;  the  weight  added  to  the 
quinine  sulphate,  giving  the  total  quinine  sulphate  remaining  un- 
changed. This  value  was  converted  into  bisulphate  by  the  factor 
1.244,  and,  by  deduction  from  the  original  weight  of  bisulphate,  the 
percentage  loss  due  to  conversion  into  quinicine  obtained.  The  quini- 
cine was  removed  from  the  tartrate  mother  liquor  by  precipitation 
into  ether,  and  identified  by  the  melting  point  (6o°  C),  the  specific 
rotation  in  chloroform  (+44°),  and  the  formation  of  insoluble 
thiocyanates  and  hypochlorites.    The  following  conclusions  have 
