D. 3. Articulata. Cl. 4. Insecta. Ord. 5. Coleoptera. Cuvier. Feelers filiform. Palpi four, unequal : the posterior ones clubbed.

Thorax nearly round. Head inflected, gibbous. Elytra soft, flexible. Species 1. Cantharis vesicatoria. Blistering Fly. Latreille, torn. ii.

p. 220. Lamarck. Hist. Nat. des Animaux sans Vertebres. Officinal. Cantharis, Lond. Cantharis vesicatoria, Edin.

Dub. Blistering or Spanish Fly. Cantharides.

Syn. Cantharides (F.), Spanische Fliegenoder Kanthariden (G.), Spaansche Vliegen {Dutch), Spanca (Swed.), Machy Hisapanskie (Pol.), Cantarelle (I.) Cantharidas (S.).

This insect is found on the privet, ash, elder, lilac, white poplar, and the tartarian honeysuckle, in Spain, Italy, France, and to a certain extent over the greater part of Europe. It is two thirds of an inch in length, and one fourth of an inch in breadth, oblong, and of a green, gold-shining colour; with long, flexible elytra or wing sheaths, marked with three longitudinal raised stripes, and covering brown, membranous, transparent wings. The body is terminated by two small, callous, sharp spines, and on the head are two black, jointed feelers. The mandibles are strong, equal, and terminate in a point: there are no teeth. The jaws are partly bony, partly membranous; lobated. The corslet is small, square, and less than the abdomen. The feet are furnished with filiform tarsi, and terminated by a double pair of long, curved, horny hooks. The larva of the Cantharis live in the ground. When alive Cantharides have a foetid odour.'2 They are gathered by smoking with brimstone the trees on which they are found, and catching them on a cloth spread underneath.

They are sometimes simply shaken from the trees, and then killed by the steams of boiling vinegar, and dried either by the sun or in a stove.

Blistering flies are imported from Sicily, but chiefly from Astracan, packed in casks and small chests. The best are of a lively, fresh colour, a small size, and not mouldy, nor mixed with the Melolontha vitis, an insect resembling them in some degree, but possessing no vesicating property. It may be distinguished by its form, which is altogether more square than that of the Cantharis, and by its black feet.1 If the blistering flies have been properly dried, and are kept in a well-stopped glass bottle, they will remain unchanged in appearance, and retain their acrimony for a great length of time2; but sometimes, in spite of every precaution, they are attacked by a small worm, which, however, feeds on the soft parts only of the fly, reducing it to a powder that still possesses the active quality of the entire insect. They soon putrefy when kept in a damp place, and therefore should be occasionally spread out to the air. In the East Indies, the Meloe trianthema is used; and in China, the Mylabris variabilis, which has lately been employed to a limited extent in this country.

1 This bark and the fruit of the capsicum were formerly common ingredients in the food and drink of the Caraibs, the ancient inhabitants of the Antilles; and at present enter the meagre pot of the negroes. - Linn. Trans. 1. c.

2 It is ascertained that a person who sits under a tree on which many of these insects are, particularly at the time of copulation, experiences ardor urinae, pain of the bladder, and sometimes Ophthalmia.

Qualities. - Blistering flies have a heavy disagreeable odour, and an acrid taste. Lewis found that their active constituents are soluble both in water and in alcohol, and that the residuum is inert. Thouvenel, Beaupoil, and Robiquet have analyzed the insect.

Thouvenel treated the entire flies with water, alcohol, and ether, separately, submitting them to the press; and obtained the following results: 1st, Three eighths of reddish yellow, very bitter, extractive, affording by distillation an acid liquor: 2d, One tenth of concrete, waxy, green oil, having the odour of the flies, and yielding by distillation a very sharp acid and a thick oil: 3d, One fiftieth of concrete, yellow oil, apparently the colouring matter of the insect; and, 4th, One half of solid parenchymatous matter. He imagined that the blistering principle resides in the green waxy oil; and that the strangury produced by blisters is the effect of the acid obtained from this oil by distillation.3

Beaupoil found that an aqueous infusion of the flies, when exposed to the air, lets fall a yellow precipitate, exhales an ammoniacal odour, and reddens tincture of turnsole: the addition of ether or alcohol divides it into two parts; viz. a black gluey matter, insoluble in alcohol, and a yellowish-brown, very soluble matter.4 The black matter blistered the skin without

1 Fabricius thus describes the Melolontha : "Maxilla brevis cornea; apice multidentata. Anlennae lamellatae. Melolontha vitis. Viridis, thoracis lateribus flavis, pedes nigri." Vide Raemer, Gen. Insect, t. 1. fig. 11.

2 Van Swieten kept them upwards of 30 years in a glass vessel not particularly well corked, and they still produced vesication.

3 Annales de Chymie, xlvii. 280.

4 From one ounce of cantharides he obtained, of black matter, 2 gros. 2 grs.; affecting the urinary organs; the yellow matter did not blister when applied alone, but blistered quickly when united with wax; and a green matter, which he also obtained, acted under similar circumstances, but less actively.

Robiquet asserts, that the flies, when recently collected, yield some uric acid. By treating them with water, alcohol, and ether, he obtained a peculiar matter in the form of small, crystalline, micaceous plates, insoluble in water and in cold alcohol, but soluble in boiling alcohol, in ether, and in oils; on the presence of which the vesicating property of the flies depends, and which, in combination with oil, might supersede their use. Dr. Thomsonl has named it, Cantharidin2 Orfila has found that by distillation a volatile principle is procured, on which the foetid odour of the beetle depends.