ON  CANTHARIDIN 
247 
and  even  apoplexia.  Otherwise  its  action  is  similar  to  other  nar- 
cotics. 
The  very  decidedly  poisonous  properties  of  H.  fcetidus,  which 
contains  less  of  the  second  glucoside,  is  most  probably  due  to  a 
volatile  principle,  together  with  the  true  narcotic  principle,  helle- 
borein. — Druggists'  Circular,  April,  1866,  p.  90. 
ON  CANTHARIDIN. 
Mr.  Bluhm,  [Pharm.  Zeitsch.  Z.  Russland,  II  160,)  states 
that  the  usual  methods  for  the  extraction  of  the  active  principle 
of  Spanish  flies  do  not  yield  the  whole  quantity  of  it  that  is 
present,  on  account  of  a  portion  remaining  behind  in  the  form  of 
an  insoluble  compound.  To  obtain  this  portion,  he  recommends 
that  the  powdered  flies  should  be  stirred  up  to  a  paste  with  one- 
third  their  weight  of  calcined  magnesia  and  some  water,  and  the 
mixture  then  be  dried  on  the  water-bath  ;  after  which,  it  should 
be  supersaturated  with  dilute  sulphuric  acid,  and  then  repeatedly 
shaken  with  ether.  The  latter  extracts  the  cantharidin  with 
fatty  and  yellow  coloring  matter,  of  which  impurities  the  first  is 
removed  by  bi-sulphide  of  carbon,  and  the  last  by  alcohol.  Can- 
tharidin is,  however,  somewhat  soluble  in  those  menstruums.  In 
many  respects  it  acts  like  an  acid,  forming  compounds  with 
bases : 
Cantharidin^ 
100  parts  by  weight  of  Alcohol  (64°  F.)  dissolved,  -03 
"       "  /   "  Bisulphide  of  Carbon.  "  -06 
"       "       "  Ether  "  -11 
"       "       «  Benzole  "  -20 
"       "       "  Chloroform  "  1-20 
This  substance  is  not  volatilized  when  boiled  with  water.  The 
author  uses  its  form  of  crystallization  as  well  as  that  of  the  mag- 
nesia compound  to  distinguish  it,  together  with  its  vesicating 
action.  The  officinal  fly  showed  -26  per  cent,  of  the  principle, 
while  a  species  of  mylabris,  common  at  the  author's  place  of 
residence,  contained  nearly  double  (half  per  cent.) ;  Mylabris 
Melanura  of  the  same  neighborhood  had  very  little.— Druggists' 
Circular,  April,  1866. 
