Poll-Evil, in farriery, is an abscess formed in the sinuses between the poll-bone, and the uppermost vertebra of the neck of a horse.

When this malady is occasioned, by blows, bruises, or any external violence, the swelled part should first be bathed with hot vinegar ; but, if the hair be fretted off, and a discharge ooze through the skin, a fomentation, prepared of two parts of vinegar, and one of spirit of wine, will be more proper. Should, however, great irritation arise from heat and inflammation, it will be necessary to bleed the animal, and to apply poultices of bread, milk, and elder-flowers; which method, with the assistance of appropriate physic, will frequently disperse the swelling, and prevent the farther progress of the disease.

But, when the tumor becomes critical, and contains fluctuating matter, its maturation ought to be promoted by poultices, till it either burst spontaneously, or arrive at a state proper for applying the knife. If such operation become necessary, it should always be performed by a skilful veterinary surgeon ; as it frequently happens, that, though a complete cure of this evil be effected by common farriers, yet,by making deep incisions, resorting to corrosive mixtures, and a tedious course of hot, irritating applications, the poor animal is so disfigured as to be fit only for the meanest drudgery.

A more judicious and simple method of discussing tumors of this description, has lately been recommended by Mr. Clark, of Edinburgh.—As soon as matter is perceived to fluctuate in the part affected, Mr. C. directs a large seton-needle, armed with a cord, to be introduced at the upper part of the swelling, and brought out at the under or lower part of it: from which orifice the pus will speedily discharge itself; and in a few weeks the wound will be perfectly healed, without leaving any scar or blemish, or the least trace of the disorder.—Deep-seated abscesses may be treated in a similar manner; and, if there be two or more sinuses, the same method may be adopted, in order to obtain a depending orifice, for a free discharge of matter: thus, a cure is generally and speedily effected.