the lousy evil, from φθορία, "a loathe." It is a lousy distemper; children are frequently its subjects, and adults are sometimes troubled with it. The increase of lice, when in a warm moist situation, is very great; but a cold and dry one soon destroys them. On the human body four kinds of lice are distinguished: 1. The pediculi, so called because they are more troublesome with their feet than by their bite. These are in the heads of children, especially if sore or scabby; and often in those of adults, if they are slothful and nasty. 2. Crab-lice, see Crab-Lice. 3. Body lice; these infest the body, and breed in the clothes of the nasty and slothful. 4. A sort which breed under the cuticle, and are found in the hands and feet: they are of a round form, and so minute as often to escape the sight: by creeping under the scarf-skin they cause an intolerable itching; and when the skin bursts where they lodge, clusters of them are found there. See Acarus.

A good diet and cleanliness conduces much to the destruction of lice. When they are in the head, comb it every day; and, after each combing, sprinkle the pulp. sem. staph. agr. or coccul. Ind. among the hairs every night, and confine it with a tight cap.

Codrochitis, in his treatise on lice, says, that the powdered coc. Ind. exceeds all other means; and that it may be mixed in the pulp of apple, or in lard, and applied every night to the hair. Some writers assert, that if the pul. cort. rad. faesfr. is sprinkled on the head, and confined with a handkerchief, it destroys the lice in one night.

The body-lice are destroyed by any bitter, sour, salt, or mercurial medicine, if applied to the skin. The black soap, and the flowers called cardamine, or lady's-fnock, are said to be specifics in all cases of lice on the human body.