the majority of them are very minute-mostly of a diameter rather larger than that of the tubes among which they lie. They frequently have a somewhat linear arrangement, particularly evident in the cones, where they are frequently oval in shape, and lie end to end like a string of sausages. The walls are composed of thin membrane, upon which nuclei, or even epithelial cells, are sometimes seen, and which closely resemble the walls of the neighbouring tubes. From these From facts there can be little doubt that the cysts are produced by mation of the transformation of tubes. In order that this should take tubes. A transfor A. Epithelial cells from advanced granular kidneys, distorted by pressure. of external pressure. place, it appears to be necessary that there should be a development of a contractile tissue in the intertubular parts of the organ. By this means the tubes are narrowed where By means they have become involved in the exudation, and are even completely obstructed by the external pressure, as by ligature, at certain points. The occurrence of these cysts may be looked upon as a proof of the existence of intertubular formation. Within the parts so cut off, fluid accumulates until cysts are produced, which are most numerous where the atrophy of the tubes is the greatest. Beside the cysts thus formed there is frequently seen in Also result from dilatation hian this disease a peculiar dilatation of the capsules of the malpighian bodies, which become converted into cavities of a globular shape. An empty space remains between the wall and the capillary knot, which hangs like a pea in its pod, by a stalk from one side. It is generally reduced in size, and distorted in shape, as if from pressure. The cysts thus formed are often visible to the naked eye, giving a fine of malpig- spongy appearance to the part of the cortex affected. They probably owe their origin to the occlusion of the tubes in the manner which has been described. The fluid poured out of bodies. Section through the cortical part of an advanced granular kidney from a gouty subject, showing the transformation of the malpighian bodies into cysts. The capsules are dilated, the vascular knot compressed, while fluid has collected in the intervening space. the malpighian vessel is obstructed in its way out, and accumulates in and distends the capsule. Thus, cysts are produced either by the subdivision of the ducts or by dilatation of the malpighian body. Both proceed from the same cause, namely, from the obstruction of the tubes by external compression." Before leaving the subject of cysts as depending upon See Paper by Dr. Bristowe, Path. Trans., vol. ix. p. 309. Also Dr. Hughes Bennett, Clinical Medicine, 4th edit. p. 800. Also Paper by Author, Med. Chir. Trans. 1860, p. 239. intertubular formation, it may be pertinent to state, that as far as the author's observation has gone, the enormous cystic kidneys which sometimes occur appear to result simply from an extravagant extension of the process which has been described. When the kidneys have been apparently transformed into a collection of large cysts, however great the increase of size may be, the microscope generally shows that the renal structure which remains is altered in the manner characteristic of granular degeneration; and it may be added that the symptoms in such cases are such as belong to that disease. tion to cir culation. From the particulars which have been brought forward- Obstrucfrom the replacement of the natural structure of the organ by contractile fibrous tissue-it might be presumed that the circulation through it would become greatly obstructed; and by experiment this is found to be the case. It is not necessary to repeat the details of experiments which have been already published, but it was found by passing water through the blood vessels of various natural and diseased kidneys, that with granular degeneration the kidney could not, on an average, transmit one quarter as much water as passed through a healthy kidney under the same circumstances. The experiments were made by passing water with a fixed pressure and temperature, into the renal artery, and measuring the amount which escaped by the vein in a certain time.* *Med. Chir. Trans. 1860, p. 243. CHAPTER VIII. CLINICAL HISTORY OF THE DISEASE. Ir will be convenient, before proceeding to the symptoms and effects of granular degeneration, to consider its distribution between the sexes, the ages at which it is liable to occur, the conditions or morbid tendencies, if any exist, which predispose to it, and the circumstances, external to the body or arising from within, which have the direct power of producing the disease. Chiefly affects the male sex. SEX. The male sex is more liable than the female to granular degeneration of the kidneys. The difference is even more decided than is the case with tubal nephritis. Taking 250 cases collected from the St. George's records, extending over a period of ten years, in each case this form of kidney being distinctly described as found at the post-mortem examination, 165 of the subjects were male, 85 female; the proportion being nearly 2 to 1. In 67 fatal cases under my own observation, in which the condition of the kidney was ascertained after death, 46 were male, 21 female, again a proportion of about 2 to 1. It will presently be shown that some of the causes of the disorder particularly affect the male sex. In a great number of cases the disease is associated with gout, or with lead poisoning. Gout seldom affects women, while, from the nature of their occupations, women are little exposed to the influence of lead. These circumstances may go a great way towards accounting for the unequal distribution of the disease between the sexes. AGE. years. The disease affects a period of life which is almost exempt Belongs to from tubal nephritis. Resulting, as it does, from gradual advancing alterations of structure, and often the consequence of antecedent disease, it is seldom developed in early life. It is almost unknown before the age of 20. The author's experience has never furnished him with an example, the earliest age at which he has seen it fatal being 24. One case, however, is recorded in the hospital books, which ended at the unusually early age of 18; and this may be said to be the earliest period at which the disease has been known to cause death. Rare under the age of 30, the disorder becomes more common as 40 approaches, and about the age of 50 attains its greatest Most frequency. It, however, is very fatal for the whole time often between 40 and 60, after which, though productive of a ing at much smaller number of deaths, it continues to number its victims to the extreme limits of human life. The collection of cases already referred to from the St. George's books contains two instances where this form of disease was described as occurring at the age of 82, and up to this age it must be regarded as frequent, allowing for the small number of persons left alive at this advanced period. The accompanying table will show the distribution of the disease at different periods of life, distinguishing those cases which have come under my own notice, and those which are derived from the hospital records. Table showing the Age at which Granular Degeneration ends Fatally. terminat about fifty. Age in Years Number Fatal at stated Number Fatal at stated Number Fatal at stated Period Period |