528 
Oxidation  of  Drying  Oils. 
Am.  Jour.  Pharm. 
Oct.,  1884. 
results  from  this  injection  as  from  the  tail  inoculation  recommended  by 
Willerus.  Immunity  in  this  case  is  sometimes  perfect,  and  does  not 
cause  changes  which  occur  when  the  disease  is  taken  in  the  natural 
way.  —  Bifd.  Centr.,  1883,  pp.  674-677;  Jour.  Chem.  Soc,  May, 
1884,  p.  623. 
ACCELERATION  OF  THE  OXIDATION  OF  DRYING 
OILS. 
By  A.  Livache. 
"When  a  drying  oil,  previously  treated  with  litharge  or  finely  divided 
metallic  lead  is  agitated  with  a  solution  of  zinc  sulphate,  all  the  lead 
is  precipitated  from  the  oil,  but  the  latter  now  holds  zinc  in  solution. 
By  using  manganese  sulphate,  copper  sulphate,  etc.,  in  this  way,  every 
trace  of  lead  is  removed  from  the  oil,  but  the  lead  is  replaced  by  man- 
ganese, copper,  etc.  If  an  oil  charged  with  lead  will  dry  in  24  hours 
when  spread  out  in  a  thin  layer  on  glass,  it  will  dry  completely  in  five 
or  six  hours  if  charged  with  manganese,  in  30  to  36  hours  with  copper, 
zinc  or  cobalt,  and  in  more  than  48  hours  with  nickel,  iron,  chromium, 
etc. 
It  is  more  convenient  to  use  the  solid  finely  powdered  salt  in  place 
of  a  solution,  since  the  latter  forms  an  emulsion  with  the  oil.  In  fact, 
treatment  with  metallic  lead  and  a  solid  sulphate  may  take  place  sim- 
ultaneously, but  in  this  case  the  oil  will  contain  some  lead  in  addition 
to  the  other  metal. 
Although  solidification  of  a  drying  oil  charged  with  manganese  takes 
place  in  five  or  six  hours  when  spread  out  in  thin  layers,  the  solidifi- 
cation of  thick  layers  requires  a  long  time,  even  though  the  protecting 
pellicle  which  forms  on  the  surface  is  continually  removed.  Oxida- 
tion is  more  rapid  at  a  higher  temperature,  but  with  thick  layers  a 
long  time  is  required  for  couiplete  solidification,  even  under  these  con- 
ditions. 
A  temperature  of  50-60°  accelerates  the  oxidation  of  drying  oil, 
partly  because  the  oil  becomes  more  fluid,  and  partly  because  the  oxygen 
is  more  active  at  a  higher  temperature. 
When  a  manganiferous  oil  is  dissolved  in  an  equal  volume  of  ben- 
zene, aud  agitated  with  air  in  a  closed  vessel,  rapid  absorption  of 
oxygen  takes  place,  especially  at  a  temperature  of  40-50°.   If  the  air 
