MANUFACTURE  OF  SULPHURIC  ACID. 
255 
Drying  Oils  heat  much  more  strongly  with  sulphuric  acid  than 
the  non-drying  ones,  and  can  be  thereby  distinguished  from  them. 
Thus,  when  olive  oil  at  77°  exhibits  a  greater  elevation  of  tem- 
perature than  76°,  it  is  adulterated  with  other  oils. — Annals  of 
Pharm,from  Comptes  Rendus. 
ON  THE  COLORING  MATTER  OF  VOLATILE  OILS. 
Br  G.  E.  Sachsse. 
It  is  well  known  that  most  ethereal  oils  are  colorless  ;  however, 
there  are  a  great  number  colored,  some  of  which  are  blue,  some 
green  and  some  yellow.  Up  to  the  present  time  the  question  has 
not  been  decided,  whether  it  is  the  necessary  property  of  ethereal 
oils  to  have  a  color,  or  whether  their  color  is  not  due  to  the 
presence  of  some  coloring  matter  which  can  be  removed.  It  is 
most  probable  that  their  color  arises  from  the  presence  of  a  foreign 
substance,  as  the  colored  ethereal  oils  can  at  first,  by  careful  dis- 
tillation, be  obtained  colorless,  whilst  later  the  colored  portion 
passes  over.  Subsequent  appearances  lead  to  the  solution  of  the 
question,  and  are  certain  evidence  that  ethereal  oils,  when  they  are 
colored,  owe  their  color  to  peculiar  substances  which,  by  certain 
conditions,  may  be  communicated  from  one  oil  to  another.  When 
a  mixture  of  oils  of  wormwood,  lemons,  and  cloves  is  subjected  to 
distillation,  the  previously  green-colored  oil  of  wormwood  passes 
over,  at  the  commencement,  colorless,  while,  towards  the  end  of  the 
distillation,  after  the  receiver  has  been  frequently  charged,  the  oil 
of  cloves  distils  over  in  very  dense  drops  of  a  dark  green  color.  It 
therefore  appears  that  the  green  coloring  matter  of  the  oil  of 
wormwood  has  been  transferred  to  the  oil  of  cloves. — Ibid,  from 
Zeitschrift  far  Pharmacie. 
APPLICATION  OF  ELECTRICITY  AND  OZONE  IN  THE  MANU- 
FACTURE OF  SULPHURIC  ACID. 
The  Pharmaceutical  Journal,  for  March,  contains  the  specifi- 
cation of  a  patent  granted  to  Thomas  Bell,  of  South  Shields, 
and  enrolled  December  24th,  1852.  It  consists,  firstly,  in  apply- 
ing currents  of  electricity  in  the  sulphuric  acid  chambers  for  the 
purpose  of  promoting  the  union  of  oxygen  and  sulphurous  acid, 
