c. Cyeatini» often appears in diabetic urine in quantities that could hardly be reached in health-1.5 to 2 gm. per diem. The cause of this profuse excretion is to be found in the nature of the diet, for who ever eats a large amount of creatinin-containing meat must excrete correspondingly large quantities of this substance. A second source of creatinin is present when the patient, as so often happens in diabetes, consumes his own muscular tissue (cf. p. 89).
d. Uric Acid.—When proper methods of research are employed, normal or only slightly increased amounts of uric acid are found in the urine (Startz "). Contrary results are due to the employment of faulty methods. According to some French authors, there are cases of diabetes which are accompanied by an increased excretion of uric acid, and other cases in which uricacicluria and glycosuria alternate. These cases are referred by the writers who report them to " diabetes alternaus." e. Albltmi;)."—Statements concerning the frequency of albuminu ria in diabetes vary greatly, the numerous statistics given making the percentage all the way from 10 to 68.7 (Bouchard, Fiirbringer, Schmitz, Salles, Bussiere). The albuminuria is almost always slight. Pathological anatomy teaches us that sufferers from diabetes seldom have perfectly healthy kidneys. Perhaps the organ becomes diseased in consequence of the enormous tax put upon it by the ex cretion of such large quantities of water, nitrogenous substances, and sugar. Others believe that the kidneys are poisoned by the definite products of metabolism in the diabetic organism. Albertoni, Tram busti, and Nesti inculpate the aceto-acetic acid. Nothing definite, however, is known on this point. Concerning the transition of dia betes into granular contracted kidney, see p. 86.
4. Xon-Yitrogenous Organic Substances.—a. Acetone, aceto-acetic acid, and beta-oxybutyric acid are the most frequently encountered of these substances. All these bodies, especially the first two, have been made the subjects of numerous publications ; the literature in deed is so voluminous as hardly to be gone through with. I have myself made an exhaustive study of these bodies, not only in dia betes but in other diseases as well, and I must, in order not to draw the discussion out to too great lengths, confine myself in general to the expression of my own views. The common source of acetone, aceto
acetic acid, and oxybutyric acid is without doubt albumin. During the normal decomposition of albumin in health at most only traces of acetone (about one centigram) are excreted. In eases in which the amount of acetone is increased and the other substances appear in the urine, either (1) There is a splitting up of the albumin molecule as regards its non-nitrogenous derivatives, which normally does not take place, or (2) The normal decomposition proceeds as far as the formation of the above-mentioned substances, and then ceases, or finally (3) These substances are formed through the decomposition of certain kinds of albumin only, while they are absent in the decom position of the ordinary albumin of the food.
We cannot answer these questions definitely until the still dis puted point as to whether acetone and the other bodies are normal intermediate products of the retrogressive metamorphosis of albumin, is settled.
Acetone and acid have so many points in common that they doubtless owe their origin to one and the same process affecting the albumin molecule, and indeed it appears probable that aceto-acetic acid is the mother-substance of acetone. When but little aceto-acetic acid is formed the entire amount becomes converted into acetone, hut when a large amount is formed a part of it appears in the urine together with the acetone. The conversion of the acid into acetone possibly takes place in the urine, but in addition to this it certainly occurs within the tissues or in the blood, as the volatile acetone is found in the expired air. Since aceto-acetic acid, even outside of the body, is transformed with extreme facility into acetone, there is nothing against the probability of this assumption.
I called attention two years ago to the fact that always, whenever large quantities of acetone and aceto-acetic acid appear in the urine, the albumin of the body is being destroyed—in consequence either of insufficient nourishment, starvation, or of a poisoning of the proto plasm by enterogenous toxines and bacterial products. I have con cluded from that that the formation of these substances takes place only during the decomposition of the albumin of the body, and never during that of the albumin of the food.