The quantity of the eliminated uric acid being diminished, its retention in the body explains why gout is so frequent in people with thyroid insufficiency, and why these persons so often complain of rheumatic pains. As we have shown in our above-mentioned communication, gout is due to a degenerative change in the thyroid and kidneys, with retention of uric acid as a sequel. The presence of albumin in quantities greater than 0.5 gramme to the liter is of grave import, and denotes important change in the kidneys. Smaller quantities, or just a trace, may not be of great importance. Traces of albumin occur from a great number of causes, and are often due to the passage of toxic products through the kidney which this organ eliminates, as one of its main functions is to eliminate toxic products from the body. More serious than small quantities of albumin is the appearance of casts and renal epithelium. These, if present, indicate a destructive process in the kidneys. Even the occasional occurrence of hyalin casts is not without danger, for, according to Professor Senator,[140] of Berlin, hyalin casts are formed by degeneration of the epithelium of the convoluted tubules, which play an important rôle in the separation of solid products from the blood into the urine. The loss of these structures means a hampering of the most important function of the kidneys. Even when we find only one such cast in one or two specimens, we must not forget that a pint of the urine may contain a very large number, and thus every day large quantities of valuable kidney elements are wasted and one of the most important functions in our body is hindered. Therefore we must not pass by such a condition of things without serious thought for the future of such persons. The length of their lives will largely depend upon their diet, just as in cirrhosis of the liver. If these persons are addicted to an abundant meat diet, their chances of longevity will certainly be smaller than with milk and vegetable food. As we have seen, the liver is constantly dealing with poisons arising from the decomposition of albuminous food, especially meats. The kidneys are destined to eliminate such products from the blood and pass them out with the urine. We will treat of this subject later in a separate chapter. Footnote 140: Die Erkrankungen der Nieren, second edition, Berlin, 1906. In patients with diseases of the kidneys, the condition of the skin is of the utmost importance, as the skin is our second kidney. Therefore patients with thyroid insufficiency have less chance of a long life if their kidneys are in any way incapacitated.