GLEANINGS  FROM  THE  FRENCH  JOURNALS.  417 
GLEANINGS  FROM  THE  FRENCH  JOURNALS. 
By  the  Editor. 
On  the  Extraction  of  Cantharidin  and  on  the  Assay  of 
Cantharides.  By  M.  Mortreux — Having  observed  that  can- 
tharidin is  insoluble  in  sulphuret  of  carbon  it  occurred  to  me 
that  this  property  might  be  employed  in  isolating  the  active 
principle  of  cantharides. 
If  cantharides  are  treated  by  chloroform,  as  has  been  indi- 
cated by  Mr.  William  Procter,  and  the  solution  is  evaporated, 
the  cantharidin  is  obtained  in  the  form  of  crystals  disseminated 
in  solid  fat  and  green  oil. 
By  now  employing  the  sulphuret  of  carbon,  this  vehicle  dis- 
solves the  fatty  bodies  and  leaves  the  cantharidin  nearly  pure, 
which  it  is  easy  to  collect  on  a  filter  and  wash  and  weigh. 
The  study  that  I  have  made  of  these  facts  lead  me  to  found 
on  them  a  process  for  assaying  cantharidin  in  cantharides. 
Here  is  the  modus  faoiendi  I  offer: — 
Introduce  into  the  adapter  of  Payen's  apparatus,  for  extrac- 
tion by  vapor,  (a  vapor  percolater,)  a  wad  of  cotton,  and  on  this 
a  layer  of  fine  washed  sand,  10  to  15  millimetres. 
The  cantharides  to  be  examined,  being  reduced  to  fine  powder, 
40  grammes  (617  grains)  are  taken  and  placed  on  the  layer  of 
sand,  when  it  is  settled  by  jarring  the  beak  of  the  adapter  on 
the  table ;  over  the  cantharides  is  put  a  thin  layer  of  cotton, 
and  above  this  a  circle  of  filtering  paper. 
The  adapter  is  then  inserted  in  a  flask  containing  three  or  four 
cubic  centimeters  of  ether,  which  flask  is  connected  by  a  lateral 
tube  with  another  flask  surmounting  the  adapter.  The  appa- 
ratus is  then  heated  in  a  water  bath,  and  when  the  vapor  arrives 
in  the  upper  flask  about  60  cubic  centimetres  of  concentrated 
ether  are  poured  in  the  adapter  and  a  safety  tube  adapted. 
The  distillation  is  continued  until  the  liquor  passes  colorless 
(about  three  hours  are  required),  when  the  apparatus  is  removed 
from  the  water  bath ;  the  upper  flask  removed,  ten  cubic  centi- 
metres of  ether  added,  and  on  this  disappearing  below  the  paper, 
water  is  poured  on  to  displace  the  ether.  The  ether  is  dis. 
tilled  off  and  the  residue,  after  the  total  disappearance  of  the 
ether,  is  treated  with  60  to  60  cubic  centimetres  of  sulphuret 
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