_Remarks._--As the more general use of clysters is recommended by the author, especially in acute diseases, he has thought proper to introduce, in this part of the work, a few remarks on them, with examples of their different forms. They serve not only to evacuate the rectum of its contents, but assist to evacuate the intestines, and serve also to convey nourishment into the system; as in cases of locked-jaw, and great prostration. They soften the hardened excrement in the rectum, and cause it to be expelled; besides, by their warm and relaxing powers, they act as fomentations. A stimulating clyster in congestion of the brain, or lungs, will relieve those parts by counter-irritation. An animal that is unable to swallow may be supported by nourishing clysters; for the lacteals, which open into the inner cavity of the intestines, absorb, or take up, the nourishment, and convey it into the thoracic duct, as already described. Some persons deny the utility of injections. We are satisfied on that point, and are able to convince any one, beyond a reasonable doubt, that fluids are absorbed in the rectum, notwithstanding the opinion of some men to the contrary. In administering clysters, it ought always to be observed that the fluids should be neither too hot nor too cold: they should be about the temperature of the blood. The common sixteen-ounce metal syringe, with a wooden pipe about six inches in length, and gradually tapering from base to point, is to be preferred. It is, after being oiled, much more easily introduced into the fundament than one that is considerably smaller; and, having a blunt point, there is no danger of hurting the animal, or wounding the rectum. The following injections are suitable for all kinds of animals. The quantity, however, should be regulated according to the size of the patient. Thus a quart will suffice for a sheep or pig, while three or four quarts are generally necessary in the case of horses and cattle. If clysters are intended to have a nutritive effect, they must be introduced in the most gentle manner, and not more than one pint should be given at any one time, for fear of exciting the expulsive action of the rectum. In constriction and intussusception of the intestines, and when relaxing clysters are indicated, they should not be too long persevered in, for falling of the rectum has been known, in many instances, to arise from repeated injections. Efforts should be made to relax the whole animal by warmth and moisture externally, and in the use of antispasmodic teas, rather than to place too much dependence on clysters. FORMS OF CLYSTERS. _Laxative Clyster._ Warm water, 3 or 4 quarts. Linseed oil, 8 ounces. Common salt, (fine,) 1 table-spoonful. _Another._ Warm water, 4 quarts. Soft soap, 1 gill. Fine salt, half a table-spoonful.