抄録
Geographical and geological discriptions, together with the historical reviews of the volcanic activities since 9th century of the Mt. Yake-yama (Yake: to burn, yama: mountain) in Niigata prefecture are given Logarithmic equations representing the curves of the vertical sections of the mountain are numerically given. The temperature of the fumarole at the height of 2200 metre above the sea-level, is measured and found to be 99.1°C. The greater part of the fumarole gas is water vapour (as much as ca. 97%) and among other constituents of which carbon dioxide predominates the proportion of H2S to SO2 is determined: the gas is passed immediately into the aqueous suspension of CdCO3 or ZnCO3 and the resulting sulphite and sulphide are separated and analyzed gravimetrically as BaSO4 respectively. The percentage composition is found as follows: CO2 89.6; N2 3.7, H2S 5.4, SO2 1.1, O2 0.3; CO, CH4 and CnH2n nil. The activity of this volcano seems to be in the course of decay.
