The author has stated previously that the gaseous metabolism of animal increases to a certain extent through the administration of oxidizable substances. Then the present investigation was carried out to decide whether the oxidizable substance has any intensifying effect upon the respiration of tissue aud if so, to observe how to intensify it.
Measuring the methylen blue-de-colourisation time of frog's muscle by Thunberg-Ahlgren's method, it is shortend most remarkably when fresh lotus rhizome juice or lemon juice was administered but only a little in the case of tea-extract or 6% glucose liquid. Lotus rhizome juice oxidized with air has no effect. In short the tissue respiration seems to be intensified in proportion to the oxidizable substance administered. But comparing this with the results obtained by the oxidization test, which has been adopted in our laboratory, most of the oxidizable substance intensifies the tissue respiration in proportion to the degree of light intensity emitted, but there are some few exceptions.