ON  CANTHARIDIN. 
231 
solution  of  potash,  which  is  employed  in  Reichenbach's  method, 
furnishes  a  different  product  according  as  it  is  continued  a  longer 
or  shorter  time.  But  whilst  Volckel  is  of  opinion  that  the  treat- 
ment with  solution  of  potash  changes,  destroys  and  separates 
certain  oleaginous  bodies  which  accompany  the  creosote,  raising 
its  amount  of  carbon  and  hydrogen  and  diminishing  its  specific 
gravity,  the  author  thinks  that  it  produces  a  change  of  the  creo- 
sote itself,  characterised  by  the  elimination  of  hydrogen  and  ab- 
sorption of  oxygen. 
At  the  conclusion  of  his  memoir,  the  author  suggests  that 
creosote  of  the  formula  C24  H14  O5  may,  perhaps,  be  still  more 
highly  oxydized  by  continued  treatment  with  potash.  By  this 
means,  perhaps,  guaiacole  might  be  obtained,  a  body  which 
stands  in  close  relation  to  creosote.  Velckel  has  adopted  for  it 
the  formula  Cls  IIs  O4,  but  the  author  thinks  that,  from  Volckel's 
analyses,  the  formula  might  just  as  well  be  calculated  at  C48  li25 
O13.    We  should  then  have — - 
C24  II15  O4,  the  author's  creosote  after  one  treatment  with  solu- 
tion of  potash. 
O24  H14^  O4*,  the  same  after  the  second  treatment. 
€24  H14  O5,  Volckel's  creosote. 
€24  II13  0s  5  wantmS- 
€24  H12*  Q%  guaiacole, 
€26  H18  O2,  carvacrole  ( Schweitzer.  | 
London  Ohem.  Graz.,  Feb.  1^  1856,  from  LieMg'$  Annalen* 
CM  CANTHAEIDIN. 
By  Dr.  Wittsteiisl, 
Preparation* — Coarsely  powdered  Spanish  flies  are  digested 
in  a  sand  bath  for  a  day  with  four  parts  of  water,  strained 
through  linen,  pressed,  and  twice  again  digested  with  two  parts 
of  water ;  the  strained  liquid  is  allowed  to  settle  for  one  day,  the 
supernatant  oil  separated,  and  after  adding  wood  charcoal  one- 
tenth  the  weight  of  the  insects,  evaporated  to  dryness  in  a  water 
bath.  The  dry  mass  is  powdered  and  treated  with  sulphuric 
ether  so  long  as  the  solution  yields  on  evaporation  a  laminated 
