Note 441 — PHARMACOLOGIA. (continued 2)

Cantharidin may be obtained by the following process: Boil the cantharides in water until all the soluble parts are extracted; filter the decoction, and evaporate to the consistence of an extract. Digest this extract in concentrated alcohol, then pour off the alcohol and evaporate it; if sulphuric acid be then added to this extract, it will take up the Cantharidin, which may be obtained in a tolerably pure state by evaporation. The crystalline plates may be afterwards freed from the adhering colouring matter by alcohol.