familiar to all readers of the more recent works on the pathology of the kidney. It is not presumed that any novelty attaches to them. What the author seeks is to illustrate the several stages of renal degeneration, by portraying the appearance of the renal cells and casts at intervals during the progress of the disorder, believing that by this mode of illustration the student in this branch of clinical observation will be relieved from the embarrassment which has hitherto beset him when he seeks to know what meaning or inference he is to draw from the several varieties of casts and -cells which he meets with in the urine. The figures hitherto published to illustrate the deposit in Bright's disease are grouped together in one plate, and, with the exception of Dr. George Johnson's and Dr. Gairdner's works, no reference whatever is made to the stage of the disease at which the several varieties may be expected to appear. I venture to hope that the following illustrations may not be without their value, both to the student and the practitioner.

The sediment found in albuminous urine consists principally of certain cylindrical forms moulded in the uriniferous tubes of the kidney; these present different characters according to the stage of the disease, or the intensity of the morbid process. They may be either coarsely granular, finely granular, or partly granular and transparent, or completely hyaline. Associated with these casts are various cell-structures—the blood-cell, the epithelial cell, healthy or abortive; the compound granule-cell; and the various modifications which cell-growth undergoes during the progress of acute or chronic disease. When hæmorrhage takes place into the uriniferous tubes from the rupture of the Malpighian capillaries, the coagulum formed is washed away and appears in the urine as a cylindrical cast of a granular appearance, entangling a number of blood-cells within its mould. These casts are usually stained of a red colour by the hæmatin of the effused blood. As the hæmorrhagic state subsides epithelial cells appear in the cast, mixed with blood-corpuscles; these latter become less numerous and ultimately disappear. The casts gradually lose their fibrinous, or, properly speaking, their coarsely granular appearance, and the epithelial cells then

seem imbedded or rather held together by a fine granular exudation. In favorable cases the casts become daily more transparent and the epithelial cells less abundant. In other cases various modifications of cell-development take place; resplendent granules, free nuclei, accompany the cast; compound granule-cells, abortive epithelial cells, disintegrated granule-cells, in the shape of grape-like clusters of nuclei, and other evidence of cell-transformation, make their appearance and supply information of the nature and direction of the renal disease.

The following objects are from time to time met with in albuminous urine :

Fibrinous casts, containing blood-discs (blood-casts). (Pl. 1, fig. 1.)

Granular casts, containing epithelial cells and blood-discs. (Pl. 1, fig. 2.) Finely granular casts, containing epithelial cells, either natural or undergoing transformation. (Pl. 2, fig. 2.)

Finely granular casts, containing compound granule cells and free nuclei, and occasionally pus-cells. (Pl. 1, fig. 4, and Pl. 4. fig. 2.)

Pus-casts,-casts composed exclusively of pus-cells are very rare; but casts containing cells with reniform or trefoiled nuclei are occasionally seen. (Pl. 4, fig. 11.)

Hyaline casts, containing epithelial cells, either natural or in a state of change. (Pl. 1, fig. 12.)

Hyaline casts, containing resplendent granules, free nuclei, and here and there an epithelial cell. (Pl. 3, fig. 4.)

Hyaline casts, containing compound granule-cells, free nuclei, and disintegrated cells. (Pl. 5, figs. 4, 5.)

Hyaline casts containing large fat-granules, and grape-like clusters of nuclei, having an oily appearance. (Pl. 6, figs. 2, 4.)

Waxy or cloudy casts, without admixture or structure of any kind. (Pl. 4, fig. 12.)

Epithelial cells, isolated or in groups, from the uriniferous tubes, the pelvis of the kidney, ureters, bladder, urethra, or vagina.

Amorphous flakes of a granular material, stained of an orange-red by the hæmatin, sometimes entangling blood-discs, more frequently without. (Pl. 1, figs. 7, 8.)

Blood-corpuscles, always single, never in rouleaux.

Pus-cells, isolated or massed together in groups.

Compound granule-cells, isolated resplendent granules (free nuclei).

Botryoidal clusters of granules, or nuclei (disintegrated compound cells,) and diffuse granular matter.

Crystals of uric acid, rhomboidal or lozenge-shaped, occasionally columnar, sometimes amorphous (grit).

Crystals of oxalate of lime (octohedra). Dumb bells, or irregularly crystallized.

Crystals of the triple phosphate.

Vibriones.

Spermatozoa.

Sporules of Penicilium glaucum, rapidly developed in all albuminous fluids, according to temperature or time of year.

METAMORPHOSIS

CHAPTER V.

OF CELL-STRUCTURE AND ITS PATHOLOGICAL SIGNIFICATION.-ORIGIN AND NATURE OF THE TUBE CASTS.

Bur little attention has hitherto been paid to the progressive alteration of cell-structure which accompanies the casts in albuminous urine. With the exception of the so-called epithelial casts, and the fatty and oily and waxy casts, but little notice has been given to the various modification of cells which are thrown off as exudations from the uriniferous tubes; and no effort has been made to extract any information, as the disease advances from those transformations of the cells which are present to the eye in morbid urine. Those who adopt Dr. George Johnson's nomenclature have hitherto been content to interpret the presence of cells in the casts as significant of an acute or chronic process of desquamation, or of fatty degeneration, but no special value has hitherto been accorded to the transformation and change which the cells themselves exhibit during the lifetime of the patient.

Dr. George Johnson communicated to the Royal Medical and Chirurgical Society a paper on the Pathology of Bright's Disease of the Kidney, which was published in the Transactions' of 1846, in which he successfully showed that in one form of that disease, the epithelial cells of the kidney underwent a fatty degeneration, and that "the disease was primarily and essentially an exaggeration of the fatty matter which exists naturally in small quantities in the epithelial cells of the healthy organ." He pointed out also the diagnostic value of a microscopic examination of the urine, and that the pre

sence of renal disease might be inferred from the character of the epithelial cells seen in the sediment of albuminous urine.

These researches have done good service to the cause of renal pathology, and they have been the means of directing the investigations of others into the proper paths of observation. I desire to amplify these views, to travel onward by this road,—to extend to a wider sphere this plan of research; and if my conclusions are not always in accordance with his, I nevertheless acknowledge the benefit I have derived from his observations; his facts remain uncontradicted, interpret them as we may.

I propose briefly to notice the origin and nature of these tube-casts. The granular and hyaline casts are strictly analogous to what is formed by other epithelial surfaces having the character of mucous membranes, and further investigation into this subject convinced me that in their nature all the various forms of casts differ but little, except in their tubular form or appearance, from what is thrown off from the bronchial mucous membrane under the influence of irritation or the so-called inflammatory causes. I have traced these excretory matters in all the commoner forms of pulmonary disorder; and I have traced from the ordinary sputa of simple catarrh, through the various grades of bronchitis-especially in that somewhat unusual form, the tubular or plastic bronchitis, as well as capillary bronchitis-in pneumonia, both in the mild and severe forms, even in phthisis, types of nearly all the forms of casts found in renal dropsy.

Plates XIII and XIV represent these various forms of sputa. In fig. 1 is portrayed the hyaline appearance of the sputa, containing a few large spherical cells (mucous corpuscles), with one large granule-cell-often called a pigment cell, from its being in many cases deeply coloured greyish or black, particularly in the sputa of those living in large towns.

These sputa are the type of the hyaline casts seen in atrophying kidneys, in the gouty kidney, and in the last and more favorable stage of the curable cases of renal dropsy. In these latter cases, as I have elsewhere remarked, it signifies a simple catarrhal state of the renal tubes. That is a state in which but