arterial tension and cardiac hypertrophy, and the history of syphilis, tuberculosis, etc., will usually indicate amyloid disease. From the urine alone it is impossible to distinguish with certainty between these two conditions. It should be said, however, that in amyloid infiltration the total solids and the total quantity of urea are usually higher than in chronic interstitial nephritis, but such a rule is by no means invariable, since amyloid disease is often accompanied by a chronic disease that very much diminishes the metabolism.

As previously stated, in considering the diagnosis of this disease the physical examination and clinical history should always be carefully weighed along with the characteristics

of the urine.

The duration of this disease is largely dependent on the cause. As a rule, it extends over a period of several years -from ten to fifteen; sometimes a longer, and occasionally a much shorter, time.

The prognosis depends rather on the condition with which this renal affection is associated. As a rule, it is grave.

CHAPTER IX.

DISEASES OF THE KIDNEYS (CONTINUED).

TUBERCULOSIS OF THE KIDNEYS.

It

Primary tuberculosis of the kidneys is not very rare. occurs in two distinct forms-viz., local caseating tuberculosis and acute miliary tuberculosis. The latter form is always associated with tuberculosis in other parts of the body, such as phthisis pulmonalis and tubercular meningitis. This form rarely gives rise to distinct urinary symptoms. Local caseating tuberculosis, on the other hand, usually results in urinary symptoms to a marked degree, and it is this form that deserves special consideration in this connection.

The substance of the kidney may contain only a few, or there may be a large number of, tubercular nodules. The process very soon involves the pelvis of the kidney, and in a majority of the cases not only the pelvis but the ureter as well, and sometimes the bladder and prostate. It may be difficult to say in advanced cases whether the disease has started in the bladder, prostate, or seminal vesicles, and crept up the ureters, or whether it started in the kidneys and proceeded downward. Osler believes that in the majority of cases the latter is true, and the infection is through the blood. One kidney alone may be involved, and the disease creeps down the ureter and may involve the mucous membrane of the bladder to a greater or less extent. The process is common in the middle period of life, but it may occur in the extremes of age. It is more frequent in males than in

females.

Prominent Symptoms.-The symptoms are usually those of chronic pyelitis. The urine may be purulent for years, and there may be little or no distress. Even before the bladder becomes involved micturition is often frequent, and many instances are mistaken for cystitis. The condi

tion may be in progress for many years without marked impairment of health. In cases in which the disease becomes advanced and both organs are affected, constitutional symptoms are more marked. General tuberculosis is common. Intermittent hematuria is of frequent occurrence, denoting ulcerative changes in the mucous membrane of the tubules of the kidney.

Physical examination may detect special tenderness on one side, or the kidney may be palpable in front on deep pressure; but a tuberculous kidney seldom causes a large tumor. Occasionally, the ureter becomes occluded and pyonephrosis results; but this is rare in comparison with its frequency in calculous pyelitis.

Character of the Urine.-Early in tuberculosis of the kidney the urine is only slightly altered from the normal. There may be the slightest trace of albumin, and the sediment may contain only a very few leucocytes and an occasional blood globule. When, however, the disease becomes more advanced and ulcerative changes have begun, the urine will usually have the following characteristics :

Quantity. The total quantity of urine for twenty-four hours is generally increased, although it may be normal or diminished.

Color.-Pale. The urine is usually more or less turbid, due to the pus, blood, etc., in suspension.

Reaction. Generally acid, except when the urine contains an abundance of blood, when it may be faintly acid or alkaline.

Specific Gravity.-Usually below the normal-1010 to 1015, or thereabouts.

Normal Solids.-Both relatively and absolutely, dimin ished. If there is general advanced tuberculosis, the solids will be absolutely very low.

Albumin. The quantity of albumin is dependent, in the first place, on the amount of destruction of the kidney, and, secondly, on the amount of pus and blood present.

disintegration of the renal tissue is marked, the albumin is usually high, approximating from 4 to 1⁄2 of 1 per cent. If, on the other hand, the tubercular process is localized and not extensive, the amount of albumin may not exceed a slight trace, or trace.

Sediment.-Abundant. Chiefly pus, which is usually free, but may be more or less clumped; the pus may be

markedly degenerated. Many small round cells, some of which are usually fatty. Hyaline and granular casts, some of larger diameter, are usually present, but they may be so obscured by the pus as to escape detection. Blood is gen

erally present, but sometimes in small amount; it may, however, be very abundant, intermittent hematuria being a common symptom of this disease. The sediment also contains tubercle bacilli.

To distinguish the condition from a calculous pyelitis is often difficult. Hemorrhage may be present in both conditions, though not nearly so frequently in the tuberculous disease. The diagnosis rests on three points: (1) The detection of some focus of tuberculosis, as in the testes; (2) the presence of tubercle bacilli in the sediment; and (3) the use of tuberculin. In women the kidney involved is now easily determined by catheterizing the ureters after the plan. introduced by Kelly, of Baltimore. Dr. Edw. Reynolds, has recently reported a case of early tuberculosis of the kidney, in which the author had the opportunity of making a careful study of the urine, and in which catheterization of the ureters led to the location of the disease.

Detection of Tubercle Bacilli in the Urinary Sediment.

Either centrifugalize the urine or allow the sediment to settle by gravity; decant the supernatant urine, and wash twice by decantation with distilled water. After the second washing, centrifugalize. The sediment is then taken up by means of a pipette and placed on from four to eight coverglasses, which have been carefully cleansed in nitric acid and then in alcohol. Care should be exercised not to get too much sediment on the cover-glasses, for the layer may, after drying, be too thick, especially if there is much pus in the sediment. These cover-glass preparations are then dried by placing them on an iron or copper plate, under which is placed a very small flame (about 1/4 of an inch in height will suffice), the main object being to get very gentle heat so that the specimens will be dried slowly and without being charred. Stain the dried preparations with either carbol-fuchsin (Ziehl-Neelson) or aniline water. and fuchsin (Koch-Ehrlich) in the usual manner. Decolorize in 20 per cent. nitric acid, wash in water, and, finally, still 1" Johns Hopkins Bulletin," Nov., 1898, p. 253.

166

further decolorize in 70 per cent. alcohol for at least ten minutes. Then stain with an aqueous solution of methyleneblue, mount, and examine.

It is very important that the preparations should be thoroughly decolorized in alcohol in order to be able to distinguish between tubercle bacilli and smegma bacilli; the latter being quite readily decolorized by this means, while the former are not affected. A very close resemblance exists between these two organisms. At times the smegma bacillus appears thicker than the tubercle bacillus, and sometimes the ends have a clubbed appearance, but this is not true in all instances; consequently, the data thus far at hand are of no differential importance. Smegma bacilli are not uncommon in the urine of both male and female, particularly in the urine of those who are not cleanly. It is obvious that special care should be taken in procuring a specimen that is to be examined for tubercle bacilli. Since in those individuals who are not cleanly the smegma collect about the genitalia, it is essential that these parts be thoroughly cleansed before the urine is voided. A still better procedure is to procure a catheter specimen, if possible. Attention to these details contributes materially to a satisfactory result of the examination.

Tubercle bacilli in the urine are usually arranged in groups (Plate 9), although they may occur singly. They may be present in large numbers and easily found; on the other hand, they may be rare and escape detection even after prolonged examination. The fact that tubercle bacilli can not be found in a urinary sediment does not, then, prove their absence. In all suspicious cases a portion of the sediment (1⁄2 to I c.c.) should be injected into the peritoneal cavity of a guinea-pig. If the bacilli are present, the animal will develop tuberculosis in from six to eight weeks; if not present, the animal will not be affected by the inoculation. This constitutes the safest method for the detection of tubercle bacilli in urine.

RENAL CALCULUS.

Calculi may originate in the secreting structure of the kidney,-usually in the tubules,-forming cavities for their location in the parenchyma of the organ.

Renal calculus is usually unilateral, though there are