CATHARTICS.

WHATEVER excites the intestines to a more early, a more frequent, and a more copious discharge of their contents, may be termed a cathartic or purge. If this effect be intended to be produced in a slight degree only, the article effecting it is termed a laxative. The principal cathartic in veterinary practice, is aloes.

Castor oil, calomel, and neutral salts, may be considered as laxatives.

CERATES.

ARE ointments of a dry healing nature; the principal of which is calamine or Turner's cerate.

BURGUNDY PITCH,

Differs but little from resin, and will be found under that head.

ALOES.

THERE are two kinds used in horse practice, the Barbadoes' and the Cape. The Socotrine preferred by the human surgeon are very uncertain in their effect on the horse. Of the Barbadoes and the Cape, the first are much to be preferred.

Barbadoes aloes are obtained principally from the island of Barbadoes, and are the juice of the large leaves of the aloes boiled to a considerable thickness, and then poured into gourds, in which they gradually harden

The true Cape is the extract of a species of aloes chiefly cultivated from the Cape of Good Hope.

The Socotrine aloes are of a brown colour, inclining to red, and brittle.

The Barbadoes aloes are black, with a shade of brown, of an unctuous feeling and a stronger smell, broken with difficulty, and the fracture dull.

The Cape are darker coloured, stronger smelling, very brittle, and the fracture perfectly glossy.

Every person who uses much aloes should buy them in the mass, and powder them himself; and then, by attending to this account of the difference of the three, he can scarcely be imposed upon. Aloes purchased in powder, are too often sadly adulterated. The Cape may be powdered at all times; and the Barbadoes in frosty weather, when enough may be prepared to be kept in closed bottles for the year's consumption. They may also be powdered when they have been taken from the gourd and exposed to a gentle heat for two or three hours before they are put into the mortar.

Fifteen ounces of powdered aloes, mixed with one ounce of ginger, and beaten up with eight ounces of palm oil, and afterwards divided into the proper doses, will form a purging mass more effectual, and much less likely to gripe, than any that can be procured by melting the drug. If the physic is given in the shape of a ball, it more readily dissolves in the stomach, and more certainly and safely acts on the bowels when made up with some oily matter, like that just recommended, than when combined with syrup or

honey. It is also worse than useless to add any diuretic to the mass, as soap or carbonate of soda. The action of these on one set of organs, will weaken the action of the aloes on another.

A physic mass should never be kept more than two or three months, for after that time it rapidly loses its purgative property.

Directions for physicing will be found elsewhere. We will only add that, as a promoter of condition, the dose should be always mild. A few fluid stools will be sufficient for every good purpose. Violent disease will alone justify violent purging.

Three drachms of Barbadoes aloes will have as much purgative effect as four drachms of the Cape, exclusive of griping less, and being safer. If the horse is well mashed, and carefully exercised, and will drink plenty of warm water, the Cape may be ventured on, or at least mixed with equal quantities of the Barbadoes; but if there be any neglect of preparation for physic, or during the usual operation of the physic, the Cape are not to be depended upon, and may be dangerous.

Some persons are fond of what are called half doses of physic. Three or four drachms are given in one day, and three or four on the following; and, perhaps, if the medicine has not operated, as in this divided state it will not always, two or three additional drachms are given on the third day. The consequence is, that the bowels having been rendered irritable by the former doses, the horse is over purged, and inflammation and death not unfrequently ensues when the effect of the three becomes combined.

In physicing a horse, whatever is to be done should be done at once. Whatever quantity is intended to be given should be given in one dose.

The system of giving small doses of aloes as altera

tives, is not good. These repeated small doses lodging in some of the folds of the intestines, and at length uniting, often produce more effect than desired; and it is never safe to ride a horse far or fast, with even a small dose of aloes in him.

Most of all objectionable is the custom of giving small doses of aloes as a nauseat in inflammation of the lungs. There is so much sympathy between the contents of the chest and belly of the horse, and inflammation of one part is so likely to be transferred to another, that it is treading on very dangerous ground, when, with much inflammation of the lungs, that is given which will stimulate and may inflame the intestines

Aloes are most commonly, because most easily, administered in the form of a ball, but in a state of solution their effect is more speedy, effectual, and safe. Two ounces of aloes, and one ounce of gum, (to suspend the imperfect solution of the aloes,) are put into a pint of boiling water, and the mixture freely stirred.

When it is cold, two ounces of tincture are added, as an aromatic, to prevent the griping of the aloes, and also to keep the mixture from fermenting. The aloes must not be boiled in the water; even five minutes' boiling would take away much of the purgative effect of the drug. The dose of the solution should vary from six to eight ounces.

Aloes are useful in the form of a tincture. Eight ounces of powdered aloes, and one ounce of powdered myrrh, should be put into two quarts of rectified spirit, diluted with an equal quantity of water. The mixture should be daily well shaken for a fortnight, and then suffered to stand, that the undissolved portior may fall to the bottom. This will constitute a very excellent application for wounds, whether recent or

of long standing, and indisposed to heal. It is not only a gentle stimulant, but it forms a thin crust over the wound and shields it from the action of the air.

The principal adulteration of aloes is by means of resin, and the alteration of colour is concealed by the addition of charcoal or lamp black

This adulteration is easily enough detected by dissolving the aloes in hot water. All aloes contain some resinous matter, which the water will not dissolve, and which has very slight purgative effect. The excess of this resin at the bottom of the solution will mark the degree of adulteration.

THIS compounded body of sulphuric acid and pure argil, is in very general use in veterinary practice both externally and internally. In doses of one or two drachms, it is a useful astringent in diarrhoea, diabetes, and other fluxes; it also possesses some virtue as a stomachic. Externally, it is used as a styptic to stop hæmorrhage, by sprinkling it on the bleeding orifice, when its coagulating properties plug up the mouth of the vessel.

It is a useful escharotic to destroy fungus, and a valuable detergent for foul ulcers.

It is also a useful stimulant in inflammation of the eye; and a whey made of it forms a good astringent clyster.

When it is burnt, it is rather milder, but its properties are not otherwise materially altered.