The human body, in its normal or its pathologic state is the theater of the toxic elaborations carried on either by the organism itself, or by the microbes which are normal inhabitants, or by those which are guests of the alimentary canal.
In the first rank come the mineral substances taken with our food, even the most inoffensive, particularly on account of the mineral matters; then the products of physiologic secretion, the products of digestion, and toxic substances resulting from intestinal putrefactions. The poisons which exist in the tissue and in the intestinal canal are likewise found in the urine, either natural or modified by oxidation. In every disease of the intestinal canal there is an increase of urinary (indican) poison. There is an increase also in intestinal obstruction and strangulation. The blood, therefore, is the necessary medium between the seat of the formation of these poisons and their place