We have not yet arrived at such a clear knowledge of metabolism as to understand just where the fault lies in these cases of seeming perfect health, with the beginning of a neoplasm which may eventuate so disastrously. But we do know that what passes for good health is often fictitious, and is quite compatible with even grave disorders of various kinds. It is more than possible that the apparent well-being of the patient with beginning cancer, which is often observed to be associated with uricacidemia, points also to the correctness of our thesis in regard to its internal causation. As remarked in one of my former lectures, quoting Ribert, “no one has ever seen the beginning of mammary cancer” and no one will ever see the beginnings of cancer of internal organs. But, whatever may be thought of Haig’s theories or statements regarding uric acid, there is no question but that many maladies of many kinds have their origin in the concatenation of processes which has long been recognized clinically as lithemia. Personally I believe that sooner or later it will be generally recognized that the starting point of cancer occurs in some cell or cells, previously normal, probably as the result of local irritation, in which there is a deposit of some of the elements of faulty nitrogenous partition, induced by undue ingestion of animal protein: and that the malignant, reproductive process in the cells is kept up by a continuance of the same supply of imperfectly disintegrated nitrogenous matter. The condition of the urine furnishes a most invaluable indicator and guide as to the systemic derangements and their correction. This has not reference to the presence of sugar, albumin, or casts, but rather to other features, reflecting the manner in which metabolism is performed. This subject was gone into pretty thoroughly in my former lectures, but must be briefly considered here, because of the great importance of the subject. It is well known that, while the products of the digestion and disassimilation of carbohydrates and fats pass off by the lungs, generally without harm, those of protein and salts are eliminated by the kidneys, and may be the cause of various systemic derangements. The urine, therefore, when most carefully analyzed volumetrically, exhibits in the clearest possible manner how the metabolism is carried on and where the error lies. From a study of hundreds of complete volumetric analyses of urine in dozens of cancer patients, both in the very early and late stages of the disease, I have found that this excretion almost invariably exhibits departures from normal which are significant. First to be mentioned is the relation of the total solids excreted daily to the body weight of the individual; for it is evident that a person weighing 200 pounds should pass off more than a smaller person. The following table represents fairly well the total solids that should pass daily in order to maintain a healthy equilibrium: