桑葉

I) We made a study of the quantitative changes of the chemical constituents of mulberry leaves during the course of twenty-four hours. 2) The amount of water contained in the leaves was largest both at sunrise and at midnight, was smallest in broad daylight, and was smaller at sunset than at day break. The dry matters in the leaves showed inverse results. At sunrise and at midnight, we found difficulty in measuring the amount of water in the mulberry leaves, owing to the presence of dew-drops on the leaves. 3) Of the carbohydrates, the amounts of the total carbohydrates converted by dilute hydrochloric acid, and the cold water soluble carbohydrates in the dry and the fresh matters in the leaves were smallest at sunrise, and, increasing by degrees, were largest at sunset. 4) Of the carbohydrates, the amount of the reducing sugars both in the dry and the fresh matters in the leaves was smallest at sunrise, and increasing by degrees, was largest in broad daylight, and then, after decreasing a little at sunset and increasing again at midnight, took a decreasing turn until sunrise. 5) Of the nitrogen compounds, the amounts of the total nitrogen and the albuminoid nitrogen in the fresh matters in the leaves showed practically no changes, but in the dry matters in the leaves were largest at sunrise, were smallest both at noon and at three o'clock p.m., and were smaller at sunset than at sunrise. 6) Of the nitrogen compounds, the amount of the non-albuminoid nitrogen, such as the nitrogen precipitated by phosphotungstic acid and the nitrogen not precipitated by the same precipitant, (as in the case of the total nitrogen and the albuminoid nitrogen) showed practically no change in the fresh matters in the leaves, but, in the dry matters in the leaves, showed a tendency to be largest at sunrise, to be smallest in broad daylight, and to be smaller at sunset than at sunrise.