from ἕρπω, a branch, is a term applied to several surgical complaints, of which the characteristic symptom is that a part of one of the organs of the body protrudes through some aperture. Hence when the brain protrudes through an aperture in the skull it is styled a hernia cerebri. Most commonly, however, the term is limited to a protrusion of the bowels through some aperture in their containing walls, the integument still remaining entire; and though this protrusion may occur at almost any part of the abdomen, it does so most frequently through those apertures which naturally exist for the transmission of vessels. These natural apertures are the umbilicus, and the inguinal and femoral canals. Hence hernia tumours which occupy these apertures are named umbilical, inguinal, and femoral hernia. As hernia, when not congenital, are generally the result of violent exertions, as from lifting heavy weights, leaping, violent fits of coughing, &c., and the patient at the moment experiences a sensation as if some part of the bowels had been ruptured, the disease in common language is significantly styled a rupture. In all cases the bowel pushes before it a portion of the peritoneum, the smooth membrane which lines the cavity of the abdomen, and this membrane constitutes the sac of the hernia.

Umbilical hernia is almost always congenital, or makes its appearance shortly after birth. If there be no malformation, and means are used to reduce the protrusion and prevent its recurrence, a cure of this form of hernia may in general be easily effected, as the aperture through which the protrusion occurs has a natural tendency to become obliterated. But if means be neglected in infancy the complaint remains for life. A halfpenny or a slice of cork enveloped in chamois leather, and fixed over the umbilicus by means of a broad strap of adhesive plaster, after the hernia is reduced, is the best mode of treating the complaint. A conical compress, recommended by many, is objectionable, as it tends to prevent the natural obliteration of the aperture, and is apt to render the complaint permanent.

Inguinal Hernia. The vessels of the testicle in the male, and the round ligament in the female, proceed through the parietes of the abdomen at the groin in an oblique canal about 2½ inches in length. This canal has consequently an upper aperture or ring, where the vessels enter it, and a lower ring, where the vessels leave it. These two points, then, are probably the weakest parts of the walls of the abdomen; and on any unusual strain a knot of bowel or of omentum is apt to be forced either into the upper aperture and down the course of the vessels, or directly through the lower or external ring, where the vessels leave the canal. If the tumour remains small, and is confined to the groin, it is termed a bubonocele; but if large, as it usually is when congenital or of long duration, and distends the scrotum or labium, it is termed a scrotal or pudendal hernia. Inguinal hernia is often congenital in the male, in consequence of the aperture not having become obliterated through which the testicle descended to the scrotum; and from the much larger size of the inguinal canal in the male this form of hernia is very much more common among males than among females.

Femoral Hernia is constituted by the viscera protruding through the space between the femoral vessels and the crescentic margin of the crural arch. In consequence of the breadth of the female pelvis, and the consequently larger size of the femoral aperture, this form of hernia is much more common in females than in males.

All the forms of hernia are met with in three states:—1st, Reducible, in which the tumour may be pressed back into the abdomen, when it disappears with a gurgling noise. 2d, Incarcerated, in which the viscera have contracted adhesion to the sac, and cannot be pressed back into the abdomen, but the person suffers no particular uneasiness. 3d, Strangulated, in which the viscera in the hernial tumour are subjected to such an amount of constriction that their functions are impeded, when violent and dangerous symptoms arise, which, unless speedily relieved, end in mortification and death. All forms of hernia are apt, from special causes, to end in strangulation; hence the existence of hernia is always looked on with suspicion, as rendering life more than usually hazardous.

When a hernia occurs the person should be laid in the horizontal position, and pressure should be so applied to the tumour as to induce its return to the cavity of the abdomen. The effect of this external and scientific application of pressure—the taxis—is frequently aided by warm baths, blood-letting, the administration of tartar emetic, or tobacco enemas, with the view of inducing relaxation of the ring which prevents the return of the bowel, or of inducing collapse of the protruded bowel. Ice and ether are also sometimes applied over the tumour with the same view. If the taxis fails, and urgent symptoms arise, as constant vomiting, redness, swelling, and excessive pain in the tumour, high fever, &c., a surgical operation is required to relieve the strangulation, else rapid mortification of the tumour may occur, and death ensue within a few hours. In all cases, after the hernia is reduced, a pad with a bandage, or truss, must be applied and constantly worn, that by pressing on the aperture through which the bowel descended a recurrence of the protrusion may be prevented. (J.S.—K.)