Softening of the mucous membrane in ge neral, or of any one or more of its elements in particular, presents various degrees. In the first degree, the mucous membrane, instead of possessing that degree of cohesion which per mits of its being detached from the submucous tissue, breaks as soon as it is seized between the fincrers or blades of the forceps ; in the second° degree, the edge of a scalpel, or the finger, pressed lightly over its surface, converts it into a soft and somewhat opaque creamy looking pulp ; and, in the third stage, it is so soft that it is removed with ease by a slight stream of water. In this stage portions of the mucous membrane are found partially or en tirely destroyed, and having been removed by the fluid contents of the stomach or intes tines, as the case may be, during life, the sub mucous cellular tissue is thus found destitute of its natural covering. It is in this manner that various forms of softening are produced, as irregular or circular patches of various sizes. It is important to notice this circumstance, for, when the softening is limited to the gland ulm solitarim, as is frequently the case in dys entery, it might be overlooked ; these bodies being very small, and their entire destruction by softening being often unaccompanied by any obvious alteration of the mucous mem brane itself, the seat and nature of the intes tinal affection might not be ascertained, were it not for the presence of a nutnber of minute circular patches, which, when narrowly ex amined, are found to be the result of softening of these follicles ; for it often happens that enlarged follicles are seen intermixed with the patches, and which, when a scalpel is carried over the surface of the mucous mem brane, break down or are removed, and thus other patches are formed similar to the former. These circular patches, which have the sub mucous tissue for their base, are often de scribed as ulceration of the mucous membrane; but in all cases of doubt, the scalpel, used as above, will enable us to determine their na ture.
Softening of the mucous membrane in the form of stripes and bands, has been described with great care by Louis, and has been much insisted upon as a characteristic of inflam matory softening; but Carswell has proved its origin from post mortem causes.
Softening of the mucous membrane of the digestive organs, may present various degrees of redness, or it may be quite pale; the red ness may be confined to the softened part, or it may extend to the neighbouring parts at the same time ; or the latter may be red and the former pale.
The redness of the softened membrane may vary from a light or a dark red to a brown ish or purple ; varieties of colour the value of which it is by no means easy to estimate, inasmuch as the quantity of blood in an in flamed tissue cannot be taken as a measure of the degree of inflammation which had caused the accumulation of this fluid.
The pale softening presents also some va riety of tint. The softened tissue is either of a pale greyish or yellowish grey tint, being little altered from its natural colour ; or it may be paler than natural, when it generally presents a milky aspect, owing to the colour of the submucous tissue being seen through it.
The pale softening is found in pthisis, in tubercular disease of the mesenteric glands, and in any disease accompanied by great ema ciation.
Softening may be accompanied by thicken ing of the submucous tissues, and may pre cede and surround ulcerations.
The inflammatory softening of the other tnucous membranes resembles as closely as possible that which has been described ; it is not however so frequently complicated with post mortem effects, nor does it so often occur, except in the cesophagus, stomach, and intes tines from the action of irritant poisons, which produce it either by their direct action, or by inducing and modifying inflammation.
Softening of mucous membranes from post mortem causes, is of great importance as a pathological fact, and may be produced by the action of the secretions of the membrane itself, or by putrefaction. This last cause is of doubtful efficacy ; it is not likely to be met with in post mortem examinations, made at a reasonable period after death ; it may however suffice to cause complete decompo sition, when the membrane has been the seat of disease before death, and more particularly when the lesion has been of such a kind as to deprive the tissue of its vital properties sud denly. General putrefaction rapidly occurs in many cases of sudden death, especially in those in which the nervous system, or blood, or both, happen to be the vehicles of the de structive agent.
Softening from the action of special secre tions may occur in two manners, either by simple maceration, which is long in taking place, or by chemical action. The first rnay happen in all mucous membranes, the second in the stomach and intestines alone.
Under favourable circumstances, and at a greater or less period after death, we find softening of the coats of the stomach, per foration, and the contents of the viscus free in the cavity of the peritoneum.
Various opinions have been given by the most celebrated pathologists, to account for this phenomenon ; some embracing the views of Hunter, and recognising a chemical and post-mortem catise ; and others attributing it to certain inflammatory causes, which pro duced ulceration and subsequent perforation.
Now, Hunter's view is demonstrable by direct experiment, whilst that held by the others is disproved by the absence of symp toms during life sufficient to account for such vast organic changes, and by the difference between such ulceration and those solutions of continuity which we are now about to de scribe.
The following facts tend to strengthen the first, and militate strongly against the latter opinion. When a rabbit, dog, cat, or any animal, in fact, is killed an hour or so after a meal when digestion is going on, and is al lowed to remain in one position and in a moderate temperature, we find, after a few hours' have elapsed, that the mucous mem brane of the most depending part of the stomach is softened, and can, with the sub mucous cellular tissue and the muscular coat, be broken down with the greatest facility. The vessels ramifying in the softened part are black from the action of the solvent upon their blood.