196     MEDICINAL  VALUE  OE  THE  CA&THAK1S  VITTATA,  ETC". 
The  C.  vittata  usually  inhabiting  the  potato  vine  from  June 
untiljfrost,  in  the  Middle,  Western,  and  Southern  States,  is  there- 
procurable  in  considerable  quantities,  and  quite  adequate,  I  think? 
to  the  demand  of  our  market. 
In  an  economical  point  of  view  it  is  worthy  of  notice.  The 
C.  vittata  can  be  procured  at  a  cost  of  about  one  third,  and  I 
venture  to  say  not  exceeding  one  half  the  imported  article. 
Then  we  have  an  indigenous  vesicating  fly,  capable  of  replac- 
ing beyond  a  doubt  the  foreign  article,  as  regards  its  therapeutic 
applications  at  least. 
The  Mylabris  cichorii,  the  subject  of  the  third  investigation 
was  found  to  contain  in  500  gr.  2.13  gr.  of  cantharidin,  being 
5  per  ct.  more  than  the  yield  of  the  0.  vesicatoria. 
Thus  it  will  be  seen,  according  to  these  results,  that  the  Mylabris 
is  the  most  valuable  and  powerful  variety  of  the  vesicating  flies 
known.  It  can  be  procured  at  a  cost  20  per.  ct.  less  than  the 
Spanish  fly. 
The  Mylabris  cichorii  is  an  insect  of  about  eight  to  five  lines 
in  length,  having  long  elytra  of  a  yellow  hue,  marked  transversely 
with  three  black  streaks  of  irregular  corresponding  outlines? 
being  one  of  the  most  beautiful  of  the  beetle  tribe  of  insects. 
It  is  quite  abundant  in  China,  and  probably  in  other  parts  of 
the  East  Indies. 
Its  properties  have  been  long  known  to  the  Chinese  who  have 
employed  it  from  time  immemorial.  It  is  quite  probable  that 
it  is  the  same  insect  referred  to  by  Pliny  and  Dioscorides,  in  their 
writings. 
Of  the  numerous  advantages  of  the  process  herein  adopted  for 
procuring  cantharidin?  it  is  hardly  necessary  for  me  to  allude,  as 
they  are  quite  apparent.  The  green  oil  so  difficult  to  remove  in 
the  usual  process,  is  entirely  avoided,  as  it  is  left  in  the  residue 
after  the  fly  is  treated  with  water. 
Cantharidin,  as  1  obtained  it,  did  not  present  the  scaly 
micaceous  appearance,  but  seemed  to  be  in  minute  hexagonal 
elongated  crystals,  soluble  in  essential  oils  of  cinnamon,  sassafras, 
and  cloves,  the  fixed  oils,  olive  and  almond,  and  probably  most 
of  other  oils.  Soluble  in  cold  ether  to  the  extent  of  one  part  to 
811.4,  and  its  solubility  but  slightly  increased  in  boiling  ether. 
In  oil  of  turpentine  of  312°,  its  boiling  point,  it  is  soluble  in  the 
