138 Cantharidin in the Potatoe Fly. 
remaining at the bottom of the vessel in flocculi; the clear 
alcoholic solution of an amber colour was poured into.a 
retort, and the spirit drawn off by distillation; a reddish 
brown substance remained which possessed some peculiar 
properties. It was very pungent to the taste; when dry and 
warm it was brittle like rosin, and presented a rosinous frac- 
ture ; after remaining some minutes exposed to the air it 
became soft like wax, or more like sulphur when prepared 
for making sulphur casts, and gradually deliquesced neasly 
to the consistence of tar or treacle at 60° or 70° Faht. It 
was readily soluble in water, as might be inferred from its 
deliquescence. 
This substance was put into a portion of pure sulphuric 
et’ >; at first no change appeared, but after a few hours 
the substance softened, and by agitation the ether acquired 
a yellow colour; the ether was poured off and other por- 
tions added until they ceased to acquire colour. ‘The sub- 
was then suffered to evaporate spontaneously in the open 
air. The substance remaining after the dissipation of the 
ether was glutinous and of a light yellow colour; very high- 
ly rectified alcohol was poured over it, and instantly as- 
sumed a yellow colour, while numerous minute crystalline 
plates appeared diffused through the liquid, and soon sub- 
sided ; the small crystals were washed in alcohol and dried ; 
they were in very minute quantity, white and pearly ; the 
quantity was so small, that their properties could not be as- 
certained ; they were placed on the tender skin between 
the fingers and soon excited itching and redness; probably 
full vesication would hate been produced if a larger quah- 
tity had been used. 
-It was proposed to repeat these experiments on a larger 
and more extended scale, that the properties of the curious 
substances above mentioned might be more fully ascertain- 
ed; but it was impossible to procure a sufficient quantity © 
the Fly in which numerous larve were not busily employ- 
ed, and which probably caused the first infusions in water 
rapidly to putrify and exhale a most offensive odour. — 
