THIRD CLASS. -LO OAL DISEASES.
These, for the most part, are diseases connected with those that are not, we shall con sider first.
Poi.r.-Evm is the name given to a tumor or ab scess which forms behind the poll, in the cavity be tween the occiput and first cervical vertebra:. It owes its origin to blows or some other injury; pro bably to the constant pressure of a stiff, hard, or tight head collar. So long as the skin remains un broken, the swelling, if soft and yielding, should be frequently fomented, and warm vinegar may be used in place of water; but if it has become hard, it will be better to rub it daily with sal-ammoniac dis solved in vinegar, or else to blister it. Should the inflammation run high, the horse may at the same time be purged, and also, if in high condition, even bled with advantage. In case such measures to disperse the tumour fail—should it, in spite of all we can do, continue to enlarge and grow soft- we had better give vent to the matter at once, than wait for its spontaneous issue; for, when once formed, the matter is apt to burrow between the bones and ligaments, and do a great deal of mis chief. Therefore, give it a free outlet: and after wards search the cavity with a probe in order to inform yourself of the number and direction of any sinuses or pipes that may lead from the main chasm; which, as far as is practicable, it is generally the best practice to lay open into the great cavity. A
great variety of dressings have been recommended to our notice, and the truth is, that, taking them altogether, they may prove serviceable or unser viceable, according to the nature of the case and the discretionary judgment of the employer of them. Caustic dressings are mostly required in the first instance, and should be persevered in until the parts assume a healthful appearance, and the matter discharged is considered what is called " laudable" pus. When any dead bone or gristly or sinewy materials remain to come away, the ni tric acid lotion will be found most proper. As a caustic, we have used powdered arsenic with great advantage. A mixture of blue vitriol and sulphuric acid, made into a paste, is also occasionally useful. Whenever healthy action is established, oily or greasy applications are to be preferred, and the simpler they are the better: alum or citrine oint ment, or a turpentine unguent, or even simple oint ment.