The contents of phosphatase in pathological tissue taken from the stomach and the duodenum were investigated histochemically and the following results were obtained.
1) The contents of alkaline phosphatase taken from stomach cancer was twice as high in the pathological portion than that in the normal portion, while the acid phosphatase content in the pathological portion was thrice as high as in the normal portion. In stomach ulcer, there was little increase in the content of phosphatase in the pathological tissue, but it was not so definitely as in cancer.
2) In cases of stomach cancer, stomach sarcoma, duodenal ulcer or stomach ulcer, the phosphatase reaction of the corresponding microscopic specimens of the stomach were tested. A positive result of alkaline phosphatase was obtained in all cases, but in normal stomach the reaction was definitely negative. Acid phosphatase gave an undefinite result but in cancer the phosphatase activity was greater than in other diseases.