the microscope, unless by modifying the light. "They generally," he says, "occur, only scattered in the chronic form of Bright's disease, in fully developed fatty degeneration of the kidneys." An epithelial cell, or the rudiment of it, may often be observed in these species of cylinder, and Lehmann considers these transparent casts as the membrana propria of the urinary ducts. This membrana propria of Lehmann is the basement or germinal membrane of the renal tubes, and to suppose that it can be shed or cast off is inconceivable to any one acquainted with histological anatomy. I cannot coincide with this view, I have always supposed them composed of some viscid material; their outline is peculiar, often exhibiting fissures of the margin. Pl. IV, fig. 12.

These so-called waxy casts are of different import to the hyaline or transparent cast. Their fanciful similarity to a wax mould or cast of a tube is very difficult to realise. In the ordinary hyaline cast, some vestige of cell-structure is usually apparent, a little granular appearance in one part, or here and there a resplendent granule, the nucleus of a disintegrated cell. But the waxy cast, erroneously so called, is devoid of any similar accompaniments. It is quite translucent, its margins are perhaps faintly opalescent, and by management it may be made to roll round in the field of view, and its apparently solid character demonstrated. Its margin often exhibits fissures. They are sometimes seen in conjunction with the ordinary hyaline cast, with its occasional isolated nuclei. Pl. V, fig. 4, shows one in conjunction with the ordinary hyaline cast. It is, however, very difficult to convey by engraving the special character belonging to them. They are of more serious import than the simply hyaline cast, as they are chiefly seen in chronic forms of morbus Brightii, and I believe indicate the granular or slightly nodular kidney. They are also seen in the more unfavorable forms of the gouty or atrophic kidney. They often indicate an amyloid reaction with iodine.

The pus-cast. These pus-casts are examples of cells having reniform or trefoiled nuclei, rendered very clear and distinct by dilute acetic acid.

They may be aggregated together in a tubular form, Plate IV, fig. 11, or they cohere together in irregular number, as seen in Plate VIII, fig. 12. They are transitional cells derived from the epithelium of the renal tubes, less frequently formed, however or seen in the casts than the simple mono-nuclear, cloudy, or granular epithelial cell. They nevertheless are occasionally

seen.

Attention to the microscopic character of these several forms of casts will enable the practitioner to estimate the nature and intensity of the disease, its advance or decline, its form, and its probable termination. The blood-casts represent the period of active hyperæmia and hæmorrhage, the coarsely granular epithelial cast, with its compound inflammation corpuscles, and accompanied by amorphous granular flakes, stained with hamatin, the period of inflammatory exudation; the finely granular, semi-transparent casts, with scattered epithelial and granule cells, the subsidence of that stage. Transparent casts, with compound cells, with isolated, resplendent molecules, and grapelike clusters of granules, represent a stage of chronic, sub-acute disease of grave import; and if these casts become more and more loaded with large and gradually increasing fat-granules, and even oily drops, the progress of fatal fatty degeneration is clearly marked.

CHAPTER VII.

EVIDENCE THAT THE DEGENERATION OF TISSUE IN FATAL CASES OF MORBUS BRIGHTII IS NOT LIMITED TO THE KIDNEYS.

THE various forms of casts just described are closely indicative of the stages, as well as of the intensity of the renal disorder in cases of dropsy with albuminous urine. They are accepted as evidence of a certain degree of cell deterioration, but it must not be inferred that these deteriorating conditions are limited to these organs.

For there is reason to believe that the nutrition of other textures and organs proportionately fails; and although not so apparent, because incapable of being determined or demonstrated during life, nevertheless the tissues throughout the organism become more or less degenerate and inefficient for the purpose of life.

Alteration of cell-structure may be traced in tissues far remote from the kidneys.

Even in the acute form of morbus Brightii cases which have run their fatal course in a few weeks the epithelial cells of other parts present a granular and imperfect appearance. The epithelium of the mouth, throat, and alimentary passages is granular, and sometimes even fatty, the pavement epithelium of the bladder often most prominently so. The epithelial cells of the bronchial mucous membrane are cloudy and granular, and accompanied by evidence of cellular deterioration identical in character to what we witness in the renal tubes.

Even in the most acute cases structural changes in the heartfibre are present.

Virchow says the small arteries which lead to the epithelial layers are everywhere diseased; and not only in the most advanced forms of renal degeneration, such as that known as the amyloid degeneration, but in the other various forms of renal dropsy, the small arteries of the whole digestive tract, from the buccal cavity to the anus, are similarly affected.

The inevitable result of this wide-spread decay is that the parts and cells which are the seat of it become inefficient in their power of ministering to the functions either of nutrition or excretion. The gland-cells imperfectly perform the function of secretion, and the vessels supply defective nutrition to the tissues from which the epithelial gland-cell is formed.

A few proofs of this widespread degeneration may be adduced.

The bronchial mucous membrane exhibits remarkable proofs of the wide spread degeneration of tissue. Plate XI, fig. 4, represents a vertical section through one of the smaller bronchial tubes. No trace of ciliated epithelium is visible; the successive layers of cells, as they form, are more indicative of the mucous corpuscle or effete cell than of the layers seen in healthy tissue. Immediately beneath the basement membrane the fibro-clastic tissue is seen studded with fat-granules, and subordinate to it the layer of unstriped muscle is seen also fatty and degenerating. Figs. 5 and 6 represent these layers separately and more highly magnified.

The expectoration in these cases of morbus Brightii is represented in fig. 3, and presents the usual evidence of imperfect cell development invariably present when a mucous membrane is the seat of nutritive or irritative disturbance.

Nor must the change which takes place in the ordinary fatcell of the subcutaneous connective tissue be overlooked; this, which in health contains fat more or less solid, and which may

* Virchow, p. 378.

be considered to represent its ordinary nutritive contents, in these states of general anasarca contains only a few fluid drops of oily-looking fat, but is crammed to over-distension with a thin, serous, albuminous fluid.

With these facts before us, we must be led to the conviction that the agency of deterioration in renal dropsy is not a local agent, manifesting itself only in renal cells, but that it is some widespread depressing influence, pervading the organism; operating perhaps, less palpably, but not less fatally, everywhere.

I may here be permitted to remark, with regard to this universal decadence, that, throughout the entire scries of epithelial mucous membranes, there appears to exist a uniform law of decadence common to all the epithelial cells, whatever the function of those cells may be. So that whether they be the scaly or pavement, the spheroidal or glandular, the oval or ciliated-whether the function of the cell be secretory or simply protective-when under the influence of a morbid cause, they severally exhibit a departure from the healthy type of the tissue to which they belong in a direction common to them all.

They first become cloudy, swell, and look rounded, and apparently filled with a fine granular matter, in which the nucleus is concealed; this is the so-called mucous corpuscle; the nucleus, in many of these cells, becomes much larger in appearance, and the contents more distinctly granular. All these cells may rapidly disintegrate, and yield, by their breaking up, the mucin which is so abundant in all catarrhal affections in which these cells are so numerous. Next in order we meet with cells with highly resplendent nuclei, refracting light highly. These fatty nuclei accompany cells of much larger diameter. These are the so-called Gluge's inflammatory corpuscles. Other cells continue to exhibit well-formed nuclei, but differing materially in form from those aready noticed. They are smaller in diameter than the fat-granule-cell (Gluge's). The nucleus may be made very distinct by dilute acetic acid; and it presents various forms or appearances-reniform, tre