This affection of the kidneys, which has been named after its discoverer, Bright, and has of late been extensively investigated, is of extreme importance. It has been termed granular degeneration, by Christison, and nephrite albumineuse, by Rayer. We treat of it in connection with inflammatory affections of the organ, for reasons which will appear in the sequel.

It is generally a chronic disease; however there are numerous cases that incline to an acute course, and some equal, or even exceed, acute inflammation in rapidity.

It assumes very different forms, which have reference either to the degree and rapidity of the disease, or to its stage of development; the former bear a close relation, first, to the amount of local reaction in the renal tissue, and, secondly, to the dyscrasic state of the blood. We shall commence by describing the various phases which the disease presents as distinct forms; we shall then examine its complications, their course, stages, degrees, and transitions, and lastly, arrive at a general analysis of the disease.

The cortical substance is that which is primarily and chiefly affected; in the course of the disease, however, the tubular substance also becomes involved in the manner which will be immediately delineated.

First Form

The kidney appears enlarged, swollen, heavier; the cortical tissue is almost uniformly infiltrated with dirty brownish-red, turbid fluid, and the bloodvessels, with the tissue immediately surrounding them, are delineated on this background in the shape of spots, or streaks of a darker red. Other red spots may be visible, which are owing to extravasations of blood into the tissue, - ecchymoses. The pyramids, however, present a similar though darker discoloration, with dull-red striae. The entire parenchyma, but more especially the cortical substance, is peculiarly pulpy and friable, and the surface, presented by section or fracture, yields a reddish-brown, limpid, delicately flocculent and opaque, sanguinolent and slightly viscid fluid. The organ generally is characterized by a turgid though flabby state. The fascia propria, from the injected state of its vessels, but more from the exudation of blood into its tissue, is of a dirty red color, and is easily detached; the mucous membrane of the calices and pelvis is similarly reddened and tumefied; and their cavity contains a thin, muco-sanguinolent, turbid, urinous fluid.

Second Form

Besides the increase in size and weight found in the first variety, the cortical substance presents an infiltration of a grayish or grayish-red, or yellow, viscid, and turbid fluid, which pervades it uniformly or in diffused spots; the color of the tissue corresponds, and if more carefully examined, an indistinct, dotted, or linear arrangement is perceived. At the same time, small punctiform or striated ecchymoses are found, which are the more conspicuous the paler the color of the infiltrated tissue. The tissue frequently presents the infiltrated and pallid appearance in some parts, whilst the hyperaemia and ecchymoses predominate in others; this constitutes the combination of partial anaemia and hyperaemia, alluded to by authors as a special variety. The organ appears of diminished firmness, but this character is less marked here than in the first form. The renal fascia observes the same bearing, the mucous membrane of the pelvis and calices of the kidney is of a roseate hue, and tumefied; and the latter contain a flocculent, turbid, yellowish or reddish-white fluid.

Third Form

There is considerable enlargement and increase in weight; the cortical substance is completely anaemic; and only a few solitary dilated vessels, bearing an asteroid, convoluted, or striated appearance, are seen in it. The cortical portion presents an increase in diameter of from five to nine lines; its surface is smooth and slightly glossy; it is tense, friable, and infiltrated with a large quantity of opaque, milky-white, or yellowish fluid. The superficial layer more particularly, but also the deeper-seated parts, are found to be made up of white or yellowish-white, loose, tense granules (Bright's granulations), of the size of a poppy-seed, or a pin's head; in the neighborhood of the pyramids these granulations assume a linear appearance.

The increase of the cortical substance either extends to the base of the pyramids only, or affects those portions also that dip down between the latter; by this means the pyramids, and more particularly their apices, become compressed. The pyramids are of a pale-red color, and from the granular cortical substance forcing its way between the tubuli and separating them, the basis of the pyramids presents a frayed or unravelled appearance, resembling a plume with dependent feathers, or a sheaf of wheat.

The renal fascia is easily detached; its tissue is swollen and opaque, the mucous membrane of the calices and pelvis of the kidney is reddened, and there is a milky, turbid, viscid fluid in their cavities.

Fourth Form

The increase in size and weight is very considerable, and the consistency of the tissues is much diminished; the cortical substance is very tense, and here and there appears almost fluctuating; its tissue is completely anaemic and very friable, and gorged with a large quantity of milky-white or yellowish juice. The granulations exceed the size of millet-seeds, and equal that of hemp-seeds; and as this enlargement is chiefly effected in the peripheral layer, they project from the surface of the organ, and give it a racemose appearance. Occasionally, we find this increase of size occurring with great rapidity in sections, and we then have an accumulation of granulations shooting like a cauliflower from the surface, and producing irregularities and nodulated protuberances upon the kidney. The granulations are very soft, tear and dissolve upon the slightest touch; the renal sheath is almost unattached, the pyramids are of a pale-red color and undefined, and the reddened calices and pelves contain a viscid creamy fluid.