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stances, but, moreover it has been shown by Gautier that certain alkaloids which he terms leucomaines, having poisonous properties, are formed within the living organism and independently of the action of bacteria—waste or effete debris—by the accumulation of which in the system the vital processes are arrested. As examples of these he gives betain, guanin, xanthin, kreatinin &c. The accumulation of these substances in the system is prevented either by their destruction by oxidation, or by their elimination through the agency of the kidneys and liver. That products are formed in the living body which, if not eliminated, produce poisonous effects is well shown in cases, for example, of uraemia, gout or diabetes. The majority of observers are of opinion that uraemia is not solely due to the effect of an excess of urea or of ammonium carbonate in the blood, but to the poisonous action, in addition, of such substances as kreatin, kreatinin and other extractives or waste materials which have accumulated in the system from defective excretion by the kidneys. In gout we have uric acid exerting its poisonous effects on the nervous centres, and modifying the nutrition of parts of the body. In diabetes we have not only in some cases the formation of glucose taking place in the system, even when saccharine and starchy foods are withheld, but we have also evidence of some abnormal molecular change in the constitution of the tissues, as shown by the marked tendency to carbuncle and to tuberculosis of the lungs. As the disease advances we have symptoms of drowsiness showing themselves, the result of some abnormal product in the blood acting on the nervous system; later on acetone appears in the urine, and in general, not long after this stage has been reached death takes place. In the Croonian lectures for 1886 I endeavoured to show that there were grounds for regarding living albuminous compounds as made
