Lethargy, or Lethargus, a species of apoplexy, which is manifested by an invincible drowsiness, or inclination to sleep, from which the patient is with difficulty awakened; and, if roused, he remains destitute both of sense and memory; so that lie soon relapses into his former sleep. It is attended with an increased degree of heat; slow fever; full pulse ; paleness ; swelling of the eyes ; and a coldness of the extremities.

Various circumstances concur to produce this affection : the more remarkable of these are, injuries of the brain, arising either from external or internal causes ; congestions of blood in the head ; terror, anger, or other depressing passions; to which may be added, sneezing medicines, and strong exhalations of flowers.

Many remedies have been employed to remove this growing drowsiness, with different degrees of success. In plethoric persons, blood-letting, blisters, and emetics, have often procured relief. Con siderable benefit has also been derived from the sudden affusion of cold water upon the head ; from the use of stimulant clysters; and the burning of feathers, or other fetid substances, held near the nostrils. The patient ought to avoid whatever is difficult of digestion, such as heavy salt meats, fish, milk, and cheese. His diet should be light, and taken in small quantities; while he must endeavour to resist and counteract the propensity to sleep, by frequenting chearful company, taking daily and moderate exercise in the open air, or similar exhilirating means.

Lethargy, in Farriery, a disorder to which horses are frequently liable. It is easily discovered, when the animal rests his head with his mouth in the manger ; is often inclined to eat, but generally falls asleep with the food in his mouth, and frequently swallows hay or corn without chewing it.—In such case, emollient clysters are equally useful and necessary : it will also be advisable to take a little blood, if the horse be young and robust, but in old animals, diligent curry-combing, and moderate walking, or occasional bathing in the sea, or a river, will be more conducive to their cure. Volatile salts, and other pungent odours, are here likewise of service, and should be often applied to the nostrils.—The following alterative purge may be administered, and repeated, if there be a prospect of recoyery: Take one ounce of socotrine aloes, half an ounce of myrrh, two drams of asafoetida, a similar quantity of gum ammoniac, and one dram of saffron. These jngredients are to be carefully mixed, and formed into a ball, with syrup.

Such remedies are generally attended with success, if the horse be not old, but in the possession of its vigour. Farther, it is a favourable symptom, if he have a tolerable appetite; drink freely, without drivelling; lie down and rise carefully, though seldom. But, if the contrary circumstances occur, and the animal be altogether listless, taking no notice of whatever happens about him ; if he dung and stale rarely, while he is sleeping and dozing; these appearances prognosticate a speedy dissolution, which cannot be prevented by art.