in zoology, a genus of insects of the order of coleoptera. The antennae are jointed, the last joint being oval; the breast is roundish; the elytra are soft and flexible; and the head is inflected and gibbous. There are 16 species, principally distinguished by their colour. The most remarkable is the vesicatorius, or cantharis of the shops; which, when bruised, is universally used as a blistering plaster. These insects are of a shining green colour, intermingled with more or less of a blue and a gold yellow. They are found adhering to different kinds of trees and herbs, in Spain, Italy, and France; the largest and most esteemed come from Italy.

Cantharides are extremely acrimonious: applied to the skin, they first inflame, and afterwards excoriate the part, raising a more perfect blister than any of the vegetable acids, and occasioning a more plentiful discharge of serum. All the blistering compositions have cantharides for their basis. The external application of cantharides is often followed by a strangury, accompanied with thirst and feverish heat; this inconvenience may be remedied by soft unctuous or mucilaginous liquors liberally drank.

Cantharides taken internally often occasion a discharge of blood by urine, with exquisite pain: if the dose is considerable, they seem to inflame and ulcerate the whole intestinal canal; the stools become mucous and purulent; the breath fetid and endaverous; intense pains are felt in the lower belly; the patient faints, grows giddy, raving mad, and dies. All these terrible consequences have sometimes happened from a few grains. Herman relates, that he has known a quarter of a grain inflame the kidneys, and occasion bloody urine with violent pain. There are nevertheless cases in which this stimulating fly, given in larger doses, proves not only safe, but of singular efficacy for the cure of diseases that yield little to medicines of a milder class. In cold phlegmatic sluggish habits, where the viscera are overloaded, and the kidneys and ureters obstructed with thick viscid mucous matter, cantharides have excellent effects: here the abounding mucus defends the solids from the acrimony of the fly, till it is itself expelled; when the medicine ought to be discontinued. Groenveld employed cantharides with great success in dropsies, obstinate suppressions of urine, and ulcerations of the bladder; giving very considerable doses made into boluses with camphor; and interposing large draughts of emulsions, milk, or other emollient liquids: by this means, the excessive irritation, which they would otherwise have occasioned, was in great measure prevented. The camphor did not perhaps contribute so much to this effect as is generally imagined: since it has no sensible quality that promises any considerable abatement of the acrimony of cantharides: nitre would answer all that the camphor is supposed to perform; this, with milk, or emollient mucilaginous liquors, drank in large quantity, are the best correctors. Cantharides, in very small doses, may be given with safety also in other cases. Dr Mead observes, that the obstinate gleetings which frequently remain after the cure of venereal maladies, and which rarely yield to balsamic medi- Melon cines, are effectually remedied by cantharides; and that no one remedy is more efficacious in leprous dis- orders; in which last, proper purgatives are to be occasionally taken during the use of the cantharides.

The best and safest preparation of cantharides for these purposes, is a spirituous tincture; and indeed in all cases, the tincture is far preferable, for internal use, to the fly in substance.

The virtues of cantharides are extracted by rectified spirit of wine, proof spirit, and water; but do not arise in distillation. The watery and spirituous extracts blister as freely as the fly in substance; whilst the fly remaining after the several menstrua have performed their office, is to the taste insipid, and does not in the least blister or inflame the skin.