CASTRATION
—is the loss of the testicles by extirpation, which requires a very nice eye, and steady hand, in the operator: for, although it has, in general, been performed by Vulcanians of the inferior order, who are strangers to the delicate structure and formation of the parts, yet it is now to be anxiously hoped, we are fast emerging from former ignorance, and that we shall become as expert and dexterous in this art (if not so famous) as the Italians. There are two modes of operation; one of those not of long standing: the original manner of operating was by first casting the horse upon a bed of straw, properly prepared for the purpose; then securing the testes by bandage, and making an incision longitudinally through the scrotum; laying bare the testicle, and, after making firm a waxed thread around the spermatic cord, the testicle was then extracted by the knife, and the farther effusion of blood prevented by the hot iron, or actual cautery. This is the method still in use in most parts of the kingdom, and most probably where the greater number of colts are bred; but in the present increase of veterinarians, some verification of the old adage, "New lords, new laws," must be expected; and they proceed in a different way.
Presuming upon the possibility of the cauterized eschar coming away by chance or accident, and the profuse hæmorrhage that might probably follow, before the apparatus could be again collected, and the horse reduced to a proper position for securing the arteries from a farther effusion of blood, the following mode is now adopted. The horse being cast, and the incision made through the scrotum, as before described, the spermatic cord is then secured by passing across it a slit stick up close to the body, which is secured at each end with the waxed thread used by shoemakers: this acting as a tourniquet upon the artery, the separation and dissection is then made with the knife; after which a few pledgets, of warm digestives, are introduced; no cautery at all applied; a trifling inflammation, with consequent discharge, ensues; the superfluous parts slough off, and ten days or a fortnight terminates the whole.
In respect to the age and season most applicable, and best adapted, to the operation, custom and experience seem to have left no room for improvement: twelve or thirteen months old is the best time to perform the operation, and in the months of April, May, or June, that either extreme of heat or cold may be equally avoided. In the last seven years, several practitioners of the new school (to shew the superiority of art over NATURE) held forth the theory of castrating horses of any age, without the least confinement or rest, the subject being permitted to go directly about his business as usual. This proposition was too surprising, and too alluring, not to obtain converts; numbers acquiesced; theory was in a variety of instances reduced to practice; and the practice soon proved (to the mortification of the owners) the truth of the adage, "Dead men tell no tales."
CATARACT
,—the technical term for a defect of the eye, to which no particular cause of origin has been yet decisively ascertained. The faculty define it, "an opacity of the crystalline humour of the eye, which prevents the rays of light passing to the retina, and of course preventing vision." Doctor Hunter says, "it is when an inflammation in the coat of the crystalline humour hath rendered it opaque." But Mr. St. Yves seems to be of opinion that the crystalline humour swells. He also divides the cataract into the true, the doubtful, and false: the true he subdivides again into three; the doubtful into four; and the false into the glaucoma, and the shaking cataract. All this division and sub-division seems little regarded even by the most curious and indefatigable in anatomical researches; particularly as it is much to be regretted, that, with every professional and energetic endeavour, no medicines, external or internal, have ever been discovered, that are known certainly capable of removing this disorder. In the human frame, methods of operating on the crystalline humour were successfully practised by Sharp, Daviel, and others: little, however, is to be expected with the horse. In such case, perhaps, it may be "better to bear those ills we have, than venture upon those we know not of."
CATHARTICS
—are synonimous with purgatives, and include all medicines of that description.
CAUSTICS
—are medicines which externally constitute a destruction of the texture (or superficies) of the parts to which they are applied. Caustics are of different kinds, and of various powers, according to the reduction, or extirpation, for which they are intended. The actual cautery, or red-hot iron, is used in firing, as well as for the farther prevention of sand-cracks already broke out. The antimonial caustic, or butter of antimony, (in judicious hands), is a complete and perfect cure for poll evil, fistula, quittor, and canker in the foot. Lunar caustic is an admirable counteraction to warts, and fast-shooting fungus. Red precipitate is an excellent substitute, when so much strength is not required; few wounds in horses can be brought to a favourable state of cicatrization without it.