The congenital rupture, then, has no proper sac, but is lodged within the tunica vaginalis in close apposition with the testis • hence many of its peculiarities can be explained. It is obviously the only kind of hernia in which an adhesion can exist between the testicle and the protruded viscus, and it is also evident that the testis does not bear the same relation to the protruded viscus in this that it does in cases of ordinary rupture. Here it is higher up, and seems to be more mixed and identified with the other contents ; the entire tumour is more even and firm, the protruded parts are less easily felt and distinguished ; and I I esselbach states that when strangulation is present, the sac is every where equally tense, and the testis cannot be felt at all. In very young infants a small quantity of fluid is often present along with the intestine in the tunica vaginalis : it disappears when the child is placed in the recumbent posi tion, and does not add to the difficulty or im portance of the case. it has been stated that the tunica vaginalis has a natural tendency to become closed at its neck, and therefore is it more likely to thicken and diminish in capacity in this situation so as to form a band round the protruded viscus. l'ott* was of opinion that congenital hernia was more subject to be con stricted at the neck of the sac than any other : Wilmer stated that out of five cases of congen ital hernia on which he operated, three were strangulated at the neck of the sac; and Sandi fort and others maintained the same doctrine. Scarpat thought that every displaced portion of peritoneum possessed the same tendency to contraction, and advanced it as a reason why stricture in the neck of a hernial sac should be more frequent in all kinds of hernia than is generally supposed. It is not easy to place implicit reliance on this latter opinion, because the neck of the common hernial sac when once formed is never again completely closed ; but with respect to congenital hernia the observa tion appears to be equally correct and im portant.
Scarpat describes a form of hernia which may under certain circumstances of imperfect or care less examination appear to be devoid of a proper sac, formed by a descent of the peritoneum. This occurs at the right groin, is always large, and is formed by a protrusion of the crecum with the appendix vermiformis and the begin ning of the colon. The mecum is placed in the right ileo-lumbar region, and a portion of it does not possess a peritoneal covering, but lies abso lutely without the great abdominal membranous sac : when therefore these parts are protruded, a portion of the ececum and the beginning of the colon will be found included and contained in the hernial sac, while another portion of the same intestines will be necessarily without the sac, and lying denuded in the cellular substance which accompanies the descent of the perito neum in the hernia. If this tumour is opened into by an incision carried too much towards its external side, the cmcuin and colon will be exposed lying outside of the peritoneum,and ap parently devoid of a hernial sac; but if cut into precisely in the middle or a little towards the inner side, under the cremaster muscle and the subjacent cellular tissue, the true hernial sac will be found, formed of the peritoneum.
Within this will be seen "the greater portion of the ccecum with the appendix vermiformis, and likewise the membranous folds and bridles which seem to be detached from the hernial sac: to be inserted into these intestines, the smaller portion of which will be without the sac, in tile same manner as when these viscera occupied the ilco•lumbar region." 'This form of rupture I have never seen, and must there fore refer the reader to Scarpa's work, wherein lie will find the peculiarity most satisfactorily explained.
But in the arrangement of Immix, that di vision is most practically interesting which has reference to the condition or state of the intes tine or other protruded viseus, and the disease is then described as being reducible, or irredu cible, or strangulated.
1. A hernia is said to be reducible when it either retires spontaneously on the patient as suming the recumbent posture, or can be re placed without difficulty to the operator or future inconvenience to the patient beyond that resulting from the employment of measures adapted to retain it within the cavity. This condition supposes that the relation (particu larly as to size) between the hernia and the aperture through which it had escaped has not undergone any alteration.
2. It is irreducible when there is such a change in the structure, situation, or other con dition of the protruded viscus as to render it impossible to be returned, although the aper ture through which it passed may offer no im pediment. There is another case in which a hernia has been considered irreducible, namely, when it would be impolitic or unwise to attempt the reduction, supposing it to be perfectly practicable.
3. A hernia is strangulated when the relation as to size between the protruded viscus and the aperture through which it has passed is so altered as not only to prevent reduction, but to cause such a degree of compression at the aperture as will interrupt the circulation through the escaped viscus, and endanger its vitality. This condition has been supposed to exist in two different forms, strangulation by inflammation and by " engouement,"• or as Scarpa terms them, " the acute and chronic;"t but this division only has reference to the severity of the symptoms and to the rapidity or slowness of their progress, for although an intestine may he in a state of obstruction which will, if unrelieved, proceed to strangulation, yet the latter state cannot be said to have arrived until the return of the venous blood from it is actually impeded. The protruded viscus is then in a situation precisely similar to that of a limb round which a cord had been tied with sufficient tightness to interrupt the circulation and threaten to induce mortification.