AMINOSIS, the abnormal presence of amino-acids in the organism. Proteins are made up of long chains of amino-acids. In the process of metabolism the proteins are split up into their constituent amino-acids. Some of these acids are used in the synthesis of new body proteins, but the majority are further re duced by oxidation and deaminization, to carbon dioxide and water. The amine radical is synthesized into urea and excreted as such. In certain abnormalities of metabolism, this change does not take place and the body loses the power of converting the amino-acids into their normal end products. In these circum stances we find amino-acids in the urine. There are several types in this group. The most important form Is when homogenistic acid is found in the urine. This substance, in the presence of oxygen and alkali, gives the urine a dark brown colour.