Abstract
In order to examine the hydrogen-ion concentration of various tissues, rats with or without Fujinawa's sarcoma were stained vitally with neutral red or fluorescein, the former being a basic dye changing its beautiful fluorescence colour from red to yellow at pH 6, 8-7, 0 and the latter, an acid dye, showing also beautiful yellow fluorescence colour only in the acid part of the tissue. The relative alkalinity of various tissues examined can be arranged as follows in the descending order of acidity : sarcoma, skin > cortical part of brain > cortical part of kidney, outer layer of heart, lung, muscle, spleen > inner layer of heart, thalamus > basal part of brain > medullary part of kidney, liver. Among various factors affecting 'the reaction of the animal tissue, the increase in body-weight and the advancement of pregnancy were found to make it less and less alkaline. The development of tumor, however, had a slighter influence than that of growth of the animal so far as the latter was not in a state of cachexia when it became considerably more acid independent of the bodyweight. [Cf. original (Japanese) p. 156.]
