Mesentery, in animal economy, signifies that fat membrane, or membranous duplicature, which is situated in the middle of the abdomen, for preventing the intestines from entangling with each other, as they lie in a small compass. It is nearly of a circular figure, being about four inches in diameter, but from three to four yards in circumference, on account of its plaits or foldings. The bowels are tied like a border around the mesentery; as the former are from ten to twelve yards in length, according to the size of the individual; so that to every inch of this circumference, there are fastened three inches of the latter..

This membrane is by Nature designed to support the intestines in their due place; to strengthen them; and to afford a situation to the milk-vessels (see Lacteals), glands, nerves, blood-vessels, etc. which are connected with the bowels. From its important use in the animal system, it may be y conceived that the mesentery is liable to be affected with various diseases, the origin and seat of which are often neither suspected, nor clearly understood. It is, however, certain, that a disordered state of the mesenteric glands generally lays the foundation of the rickets, scrophula, wens, white swellings, and early consumption. Hence the injury done to infants, by stuffing them with superfluous or improper food; by allowing children promiscuously to eat cakes, gingerbread, and unripe fruit; all of which corrupt the Lymph (which see), and cannot fail to produce distressing maladies. One of the most fatal, however, is an inflammation of the mesentery and its glands; which, though difficult to ascertain, is not a rare occurrence : it is generally accompanied with costiveness, and always with a retention of urine ; but seldom with violent fever or pain ; and on examining the parts affected, there will appear a large swollen belly, and a deep seated tension in the abdomen. Sometimes blood and fetid matter are discharged by stool ; and it is remarkable, that male children are more frequently subject to it than those of the female sex; and that the disorder, unlike other inflammations, may prey on the little patient for weeks, before it be discovered; though in acute cases, it proves suddenly fatal.

Cure :—As soon as the nature of this dangerous affection is ascertained, leeches ought to be applied to the lower belly, and a large blister to the small of the back. Emollient clysters, fomentations made of an infusion of chamomile flowers, with the addition of laudanum; and the tepid bath, will also be of essential service.

The patient's regimen and diet should be similar to that stated p, 12, of this volume: he may likewise drink sweet whey with honey, or equal parts of Seltzer water and milk. With a view to check a debilitating looseness, he ought to take decoctions of the salep-root, sago, tapioca, etc.