Ulceration as a consequence of chronic in flammation of the mucous membrane of this organ is unfrequent, but as an effect of the presence of a calculus is less so. Of the first species a description, with a fine plate, is given by Baillie, of a case in which the mucous membane covering the posterior and superior surface of the bladder was destroyed ; a simi lar case is given also, with a plate, by Walter; another is described by Pare.* A case is described by Jalon,f in which the whole of the muscular tunic was as well displayed as if it had been prepared by dissection. There are several well-marked cases on record in which this species of ulceration, consequent upon chronic inflammation, had extended to the whole of the tunics and caused an extrava sation of urine. These ulcerations are some times very numerous, almost like erosions, and they are often concealed between the folds of the relaxed mucous membrane, so that they are not discovered until the membrane is stretched out. Under the influence of either acute or chronic inflammation, pseudo-mem branes are now and then generated upon the surface of the mucous tunic of the organ, usually during the suppurating period of the affection. These membranes are either ad herent or free, and they are sometimes ex gelled through the urethra : this circumstance has induced a belief in an often repeated error, that the mucous tunic of the bladder may be entirely detached and expelled with the urine ; among those who have perpetuated this error are Ruysch arid Morgagni.
Under the influence of chronic, and much more rarely of subacute inflammation, the mucous membrane of the bladder furnishes in large quantity a species of inuco-purulent fluid. This affection was termed by Lieu taud § catarrh of the bladder. When the affection presents the subacute form, it is fre quently extended to the other tunics of the organ ; and if we examine it after death, we shall find similar appearances to those which have been described in speaking of acute in flammation. When the disease is chronic, it often lasts for years, and we then discover little change of colour in the membrane, but we find it often prodigiously thickened, the vessels varicose, and the cavity much con tracted.
Idiopathic the progress of some acute and many chronic diseases, the mucous membranes of the body not un frequently become softened, in the absence of inflammatory action in their tissues : in the bladder, however, this state has been only very rarely witnessed. This fact is important, espe cially when we reflect upon the functions of the organ and the great variations to which the liquid of which it is the reservoir is exposed. M. Louis,Il in a very careful examination of five hundred bodies, found this idiopathic softening in only two cases. In these the mucous membrane in a great portion of the fundus of the organ was reduced into a ‘c mucilage" possessing a consistence little if at all superior to that of mucous branes. The membrane thus altered was pale,
even at the limits of the softening ; there was no injection or vascular congestion at any point of the bladder, nor in any of the vessels which existed on the exterior of the organ ; neither was there at the interior any erosion or other product of inflammation. It is probable that it is in such cases that even a careful intro duction of the sound has occasioned a per foration of the bladder; it may be as well to mention that no true friability of the mucous membrane, so commonly found in inflam mation, existed in these two cases; the tunic was soft, as if formed of a viscid jelly, but it did not present either the redness, the infil tration or the induration by which inflam mation is characterised. So general is the opinion that softening is uniformly a conse quence of inflammation, that in taking an opposite opinion it appears to be incum bent upon us to state our reasons for doing so. Although the differences which may be remarked between softening of this tissue and its inflammatory condition appear to be very great, yet able observers have still be lieved themselves justified in regarding all softening as the result of inflammation. It is so important to have correct ideas on this point, that we ought here to refute the reason ing by which that opinion is supported. It is stated that softening of mucous tunics is, in the greater number of cases, united to evi dently inflammatory alterations; such as a more or less vivid redness of the softened parts, together with an injection and tume faction. This assertion is gratuitous ; for in all cases where the condition has been well observed, softening in the first degree has scarcely ever been united to unequivocal in flammatory alterations. In the second degree of softening, the existence of inflammation is frequently demonstrable.
It is especially by studying the anatomical characters of the early stage of softening that we shall be enabled to establish the non-existence of inflammation ; we may go farther, and say that the characteristics of sof tening are directly opposed to those of in flammation. In the latter we find injection and vascular congestion ; in the former the capillaries have disappeared ;—in inflammation, thickening, and at first augmentation of density in the membrane, which becomes rugous to the touch; in softening we find thinning and diminution in the density of the tunic, with loss of its tenacity, and it is soft to the touch; —in inflammation we observe specific inflam matory products at the surface and in the sub stance of the tissue ; in softening a diminu tion and absence, then a total extinction of this secretion, which is not only not augmented at the commencement of the disease, as in the first stage of inflammation, but is immediately diminished.