a clear fluid, rarely turbid or purulent. The kidney appears tough, and upon section the knife meets with much resistance (leathery consistency). On viewing the cut surface it will be found that the entire width of the kidney is decreased, but the cortical portion suffers most, so that it is narrowed, and occasionally forms but a faint rim. The marked narrowing of this part of the kidney is due to the fact that it is the most delicate, while the medullary portion contains a stronger supporting structure, so that when the newly formed connective tissue in the cortex contracts, the cortex suffers most. The pelvis of the kidney occasionally may be larger than normal on account of the contraction of the organ, but it is always so on account of the disproportion in size. In chronic nephritis due to gout and lead-poisoning it not infrequently happens that infarcts are found that contain uric. acid deposits or calcareous infiltration. Microscopic examination reveals the interstitial change as being more marked at certain points, but particularly localized in the cortex. The fibrous connective tissue is found to separate many of the tubules, and there also appears here and there marked cellular infiltration of round cells and leukocytes. The epithelial cells lining the tubules show granular and fatty degeneration in limited areas, but the greater number of the epithelial cells appear normal, and in stained preparations the nucleus of these cells has its normal selective power for the basic stains. The epithelial cells of the Malpighian bodies may also show similar changes. As the new-formed fibrous tissue contracts, some of the tubules and glomeruli atrophy, many of them being completely replaced by areas (or whorls) of sclerotic tissue. When the contraction takes place around the tubule at some distance from the Malpighian body, and blocks up the lumen, a cyst forms, which has previously been described, and this appears under the microscope as a large space. The arteries are also thickened, the intima, the media, or the adventitia showing sclerotic changes; and often the outer coat is continuous with the surrounding new-formed fibrous tissue. It will also be noted that in some areas the glomeruli and tubules are hypertrophied, they being larger than normal, and the lumina of the tubules being well marked. The veins rarely show any change, but occasionally the outer coat is thickened. From the narrowing of the lumina of the arteries anastomotic changes arise. The heart in this form of nephritis shows marked hypertrophy; this in the greater number of cases is

chiefly limited to the left ventricle, but may involve the entire organ. It is also frequently associated with dilatation. Arteriosclerosis of many of the blood-vessels of the body frequently causes chronic interstitial nephritis. Congenital narrowing of the aorta in young chlorotic individuals has been noted, which subsequently gives rise to chronic contracted kidney. A contracted kidney is found on the postmortem table which during life may not have given rise to characteristic symp

toms.

Symptoms. The symptoms may be so ill defined as to escape detection. As a rule, muscular weakness and lassitude. develop. There is gradual loss of appetite, dyspepsia sometimes appearing. Headache, pain in the neck and back, irritability of temper, loss of memory, and sleeplessness are all early symptoms. The amount of urine is greatly increased, from 3000 to 6000 c.c. being passed in a day; it is clear, acid in reaction, and of a pale, slightly greenish color. The specific gravity is low-from 1004 to 1012. Albumin, if present at all, is found in very small amounts; it may be absent altogether. The amount of urea eliminated is diminished. Some few hyaline casts may be discovered upon microscopic examination. The important characteristic symptoms relate to the circulatory system, consisting of marked hypertrophy of the left ventricle. The arterial tension is increased. The pulse is firm. There is an accentuated ringing sound at the aortic cartilage; the apex-beat is forcible and heaving. As long as compensation is maintained no symptoms are developed; however, dilatation and cardiac insufficiency soon arise. There is shortness of breath upon slight exertion, and palpitation, and gradually the symptoms of edema of the lungs appear. The patient is pale, and the eyelids may be slightly swollen. The skin of the body is dry, there being but slight tendency to sweating. Marked anemia of the chlorotic type is present. Edema, as a rule, is absent; when it occurs, it is due to secondary parenchymatous changes or failure of compensation. The eye symptoms are important, albuminuric retinitis being common in this condition.

Complications.-Cerebral hemorrhage is a frequent complication. Inflammation of the serous membranes is common. Peritonitis, pericarditis, pleurisy, pleurisy with effusion, chronic pericarditis, bronchopneumonia, lobar pneumonia, neuroretinitis and retinal hemorrhages, and edema of the glottis are all complications.

Prognosis. When the disease has once become established, there is no likelihood of a cure. The patient may live for a number of years, the average duration of life being from three to five years.

Treatment. The treatment in regard to general hygiene, diet, and so on, is the same as in other forms of renal disease. Diuretics are not indicated. Iodid of potassium is a valuable drug, continued for weeks at a time. For the palpitation and cardiac difficulty nitroglycerin is of use. Complications must be treated as they arise.

AMYLOID DISEASE OF THE KIDNEY.

This is a disease of the kidney often associated with chronic parenchymatous nephritis; it may, however, exist independently. When it is present, other organs besides the kidney are frequently affected.

Etiology. The condition occurs most often in cachectic individuals. It may arise at any period of life, but most frequently between the ages of twenty and thirty, and it is found in both sexes. Pulmonary tuberculosis, empyema, bronchiectasis, abscess formations of various tissues, especially of bone, chronic malaria, and syphilis are all predisposing causes.

Pathology. The organ is usually increased in size, sometimes being twice that of the normal kidney, and closely resembling the large white kidney. The fibrous capsule strips quite readily, the kidney being of a dull yellow color. It is of a tough, bacony consistency. On section, the cortical portion is increased in width, the Malpighian bodies often standing out prominently as small, white, glistening points. When treated with Lugol's solution, the characteristic amyloid reaction is obtained, the Malpighian bodies and the bloodvessels particularly being stained a mahogany brown, while the surrounding kidney structure is a light yellow. The reaction is better illustrated with some of the anilin dyes. (For Amyloid Reaction, see p. 520.) Cirrhotic changes not infrequently are found associated with this condition. The organ, under such circumstances, is of about normal size, very tough, and upon microscopic examination reveals the increased fibrous connective tissue. Parenchymatous changes are also associated.

Symptoms. The disease is always preceded by some chronic process, very frequently a suppurative one. The