Am.  Jour.  Pharm.  \ 
Aug  1, 1872.  / 
On  Monobromated  Camphor. 
339 
tallized.  This  oil  contained  more  or  less  of  the  latter  compound  in 
solution,  which  was  obtained  by  reducing  it  to  a  low  temperature. 
The  mother  liquors  containing  the  oil,  in  consequence  of  the  frequent 
application  of  heat,  turned  black  and  left  after  the  evaporation  of  the 
menstruum  a  black  oil,  which  in  the  course  of  several  weeks  became 
granular ;  the  oil  still  present  in  the  magma  could  not  be  removed  bj 
different  solvents  which  would  also  dissolve  the  crystallized  granules. 
On  being  expressed  between  bibulous  paper  a  grey  solid  mass  was  left 
behind,  which  was  permanent  in  a  temperature  of  32°  C.  (90°  F.), 
but  became  soft  and  oily  when  exposed  to  the  direct  heat  of  the  sun, 
which  was  above  38°  C.  (100°  F.)  This  compound  is  not  monobro- 
mated camphor  ;  its  composition  has  not  yet  been  investigated. 
Attempts  to  separate  the  whole  of  the  monobromated  camphor  from 
this  oily  substance  by  sublimation  were  not  successful ;  the  whole 
mass,  after  a  slight  white  sublimate  had  been  obtained,  near  132°  C. 
(270°  F.),  turned  black,  and  after  cooling  sometimes  did  not  separate 
any  crystals,  but  remained  liquid  and  oily,  while  at  other  times  dark 
blackish-grey  crystals  were  obtained. 
It  was  noticed  that  the  mother  liquors  of  the  first  crystallizations 
of  monobromated  camphor  contained  considerable  hydrobromic  acid, 
which  also  adhered  to  the  crystals.  The  endeavor  to  remove  it  by  wash- 
ing with  hot  water  was  not  entirely  successful,  and  necessitated  the 
drying  of  the  solid  portion  previous  to  recrystallization  from  alcoholic 
solvents.  To  avoid  these  difficulties  the  removal  of  the  acid  by  means 
of  a  weak  alkali  (carbonate  of  lime)  suggested  itself,  and,  instead  of 
alcohol,  petroleum  benzine  was  experimented  with  as  a  suitable  men- 
struum for  recrystallization. 
The  first  crystallizations,  whether  obtained  from  alcohol  or  from 
petroleum  benzine,  contained  notable  quantities  of  the  oily  matter 
mentioned  above,  in  consequence  of  which  bromine  was  liberated  on 
exposure  to  the  light.  The  greatest  portion  of  this  oil  could  be  re- 
moved by  pressure  between  bibulous  paper,  and  the  remainder  by 
subsequent  recrystallization ;  but  the  loss  of  monobromated  camphor 
was  considerable,  owing  to  its  being  partly  absorbed  by  the  paper 
with  the  oil,  and  to  remain  to  some  extent  in  the  mother  liquor 
with  that  portion  of  the  oil  not  absorbed  by  the  paper.  Gasoline  or 
petroleum  naphtha  was  found  to  be  a  good  solvent  for  this  oil,  and  to 
dissolve  at  the  same  time  much  less  of  the  monobromated  camphor 
than  alcohol,  ether  or  petroleum  benzine.    Accordingly,  when  the 
