Abstract
By the use of two sorts of water, acidic (pH 5.0) and alkaline (pH 11.0), mechanical analyses were made after International B method. Acidic water was produced by the addition of acetic acid, and alkaline water, by ammonium hydrate. After the results with two soils, contrast to each other, it was concluded that the clay part in a volcanic ashy soil (SiO_2/Al_2O_3 was about 1) was more got in acidic water, while that in an ordinary alluvial soil (SiO_2/Al_2O_3 was more than 2) in alkaline water.
