Cochineal, a drag used by dyers for imparting red colours, and also for the purpose of making carmine. It consists of an insect which is collected from the cactus cochenillifer, or, as it is differently called, nopal, or nopalleca, the Indian fig-tree ; and is found most abundantly in the provinces of Oaxaca, Tlascala, and Chiapa, in South America. It is nourished solely by the juice of the plant on which it breeds, and which be-comes converted into its substance, yielding a most beautiful scarlet and crimson colour.
The cochineal insects are usually gathered in the beginning of August, when they are killed, either by being immersed in hot water, or put into an oven moderately heated for that purpose; or, more advantageously, by being exposed to the scorching rays of the sun. - The last mentioned me-thod is reputed to be of superior efficacy for preserving the colouring property; and the coc:ineal thus treated, is of a shining silver grey. More than one million of pounds of this drug are annually imported into Europe; and it pays at present, in this country, only a convoy duty of l0d. per pound : the best sort was lately sold at from 15s. to one guinea the lb.— It is remarkable, that these worms may be kept in a dry state for more than a hundred years, without being in the least affected by the tooth of time.