Some of these which have been suggested probably have to do with local irritant action on the digestive organs, as we have previously seen that local irritation undoubtedly plays an important part in the determination of the actual time of occurrence and site of the cancerous disease. Thus, some have ascribed cancer to hot food or drink, or to stimulating drink, condiments, etc. It is quite possible that these contribute to the development of cancer in the pylorus, irritating the secreting cells in their passage. Mayo says: “In civilized man one-third of all cancers are seated in the stomach. This is not known to be the case in uncivilized man or in animals. There should, therefore, be something—some one cause—which causes this preponderance. The acid secretion may favor its development, for when we come to the colon, also with an acid secretion, we again meet with cancer, and we seldom see it in the alkaline, small intestine. Gastric ulcer, which may be pre-cancerous, is connected with hyperacidity.” In Scandinavia cancer of the stomach is remarkably frequent, according to Soëgaard, thus, of 1235 cases in Norway, 73.9 per cent. were in that location. In our last lecture we found that cancer in general was connected with a lowered alkalescence of the blood, and all our studies show hyperacidity to be related to cancer genesis; and nitrogenous acidity, or uric acid (purin, xanthin, etc.), undoubtedly plays a great part in inducing malignant action in tissues, as Haig has so long contended, even in regard to cancer. The increasing frequency of cancer of the mouth, œsophagus, and stomach in men certainly looks toward an irritating character of substances which traverse these regions, including alcoholic drinks, and the irritant effect of tobacco should not be overlooked in regard to mouth lesions. But of the millions who use tobacco only very few are affected with cancer, and only those who are predisposed thereto by some metabolic disturbance, whose true character and other manifestations are not yet fully determined. We have already referred to the practice of so-called betel chewing in the Far East as a frequent cause of cancer within the mouth, also to the wearing of the Kangri charcoal baskets in India, for warmth, causing a burn on the front of the body which may develop into epithelioma; it is claimed, however, by some that of the many cases of “Kangri burn,” but few result in epithelioma.