550 
Doryphora  Decemlineata. 
(  Am.  Jour.  Pharm. 
{      Nov.,  1882. 
the  addition  of  the  soda,  removes  any  wax,  resinous  or  oily  substance 
present,  and  the  subsequent  treatment  with  a  fresh  portion  after  being 
rendered  alkaline  removes  the  alkaloids,  whilst  most  of  the  coloring- 
matter  is  retained  by  the  aqueous  portion.  In  order  to  save  tlie  chlo- 
roform distillation  can  be  resorted  to,  care,  however,  being  taken  to 
remove  any  adhering  alkaloid  by  repeatedly  washing  with  chloroform 
the  retort  used. 
DOEYPHOEA  DECEMLINEATA. 
By  John  D.  Forbes. 
From  an  Inaugural  Essay. 
Experiments  with  the  Live  Beetles. — The  beetles  were  mashed  in  a  mor- 
tar and  macerated  with  different  solvents. 
Alcohol  yielded  a  dark  oily  extract,  having  the  characteristic  odor, 
and  when  mixed  with  an  equal  quantity  of  resin  cerate  produced  no 
irritation  of  the  skin.  The  extract  redissolved  in  alcohol  and  mixed 
with  carbon  bisulphide  separated  into  three  layers,  the  lowest  of  which 
was  dark  brown  and  soluble  in  water ;  neither  this  nor  the  two  light- 
yellow  layers  above  produced  irritation  of  the  skin. 
Acetic  ether  yielded  a  tincture,  which  on  treatment  with  carbon 
bisulphide  separated  likewise  into  three  layers,  in  neither  of  which  the 
presence  of  cantharidin  was  indicated. 
Benzin  used  as  a  menstruum  and  the  product  treated  with  bisulphide 
of  carbon,  yielded  a  dark  oil  and  extractive  matter,  but  no_ trace  of 
cantharidin. 
The  beetles  were  exhausted  with  potassa  solution,  the  liquid  neutral- 
ized with  acid,  evaporated,  the  residue  treated  with  water  and  the 
undissolved  portion  taken  up  with  alcohol ;  on  evaporation  a  dark 
granular  mass  was  left,  which  mixed  with  an  equal  weight  of  resin 
cerate,  produced  on  the  skin  in  three  hours  slight  irritation  and  redness. 
Experiments  with  the  Dried  Beetles. — The  beetles  were  killed  with 
ether,  dried,  powdered  and  exhausted  by  chloroform.  On  treating  the 
product  with  carbon  bisulphide  a  supernatant  dark  oily  layer  and  a 
heavier  light-brown  li(|uid  were  obtained,  of  which  the  former,  when 
applied  to  the  skin  of  two  persons,  produced  a  tingling,  burning  sensa- 
tion, and  in  twelve  hours  vesicles  formed  under  the  irritated  surface.. 
The  remaining  solution,  evaporated  to  dryness  and  mixed  with  resin 
cerate,  produced  only  slight  irritation. 
It  follows  from  the  above  that  the  potato  bug  contains  a  vesicating; 
principle,  but  it  is  uncertain  whether  it  be  identical  with  cantharidin. 
