I3« 
Camphor  with  Phenols. 
Am.  Jour.  Pharrru 
March,  1891. 
source  as  the  sample  first  mentioned  gives  a  still  higher  melting- 
point  than  before.  The  bulk  solidifies  at  5 2°  F.,  and,  by  separating 
the  crystals  which  first  form,  it  is  comparatively  easy  to  obtain  a 
fraction  with  a  melting-point  of  530  F.  This  is  the  highest  figure 
yet  noticed;  and  even  now  we  do  not  know  that  this  is  "  paralde- 
hyde absolute."  By  systematic  fractional  crystallization  of  a  large 
quantity  of  material,  a  still  higher  melting-point  might  be 
obtained. 
As  the  solid  polymer  "  metaldehyde "  is  almost  insoluble  in 
paraldehyde  (except  while  heated),  it  is  probable  that  the  higher  the 
melting-point  the  purer  the  compound ;  but  any  sample  which 
passes  the  other  tests,  and  conforms  to  the  B.  P.  standard  of  "  begin- 
ning to  congeal  at  io°  C."  ("  with  agitation"  being  understood), 
should  be  sufficiently  pure  for  all  practical  purposes. —  The  Chemist 
and  Druggist,  1890,  p.  852. 
COMBINATION  OF  CAMPHOR  WITH  PHENOLS.1 
By  E.  Leger. 
Camphor  and  the  phenol  are  melted  together  in  the  calculated 
proportions  in  closed  vessels.  Under  these  conditions,  compounds 
are  formed  which  decompose  easily  under  the  influence  of  heat,  or 
when  treated  with  solvents  or  with  alkalies.  That  definite  com- 
pounds are  formed  is,  however,  shown  by  the  fact  that  the  liquid 
products  contain  their  constituents  in  molecular  proportions,  and 
that  in  those  cases  where  they  crystallize  the  composition  of  the  first 
crystals  is  the  same  as  that  of  the  last.  The  addition  of  phenols  to 
alcoholic  solutions  of  camphor  reduces  the  rotatory  power  of  the 
latter  to  one-half.  The  compositions  of  the  various  products  were 
determined  by  means  of  the  polarimeter,  and  the  method  will  be 
described  in  detail  subsequently. 
PJienol  monocamphoride,  C6H6O,C10H16O,  is  a  colorless  liquid, 
which  crystallizes  only  at  about  —  23 0  ;  sp.  gr.  at  about  o°  ===  1-0205  ; 
[a\D  =  _|_  200.  Phenol  hemicamphoride,  2C6H6O,C10H16O,  a  color- 
less liquid  which  does  not  solidify  at  —  500  ;  sp.  gr.  at  o°  1-040  ; 
[a]^  =  -[-  10-5°.  It  combines  with  camphor  to  form  the  mono- 
camphoride ;  if  mixed  with  excess  of  phenol,  the  latter  dissolves, 
1  Compt.  rend.,  in,  109-111  ;  reprinted  from  Jour.  Chem.  Soc.,  December, 
1890,  p.  1427. 
