Studies on the Previons Treatment of Soils for Mechanical Analysis by Elutriation Method. (I). : On the "Onji", Allitic Volcanogenous Soil (1).

Abstract

Studies was made on complete dispersion of "Onji" (allitic volcanogenous soil) as previous treatment for mechanical analysis by elutriation. Satisfactory result was obtained by the following procedure : 5 g of sample, taken in 1 l shaking bottle, was added with 500 ml. of 5% oxalic acid solution. The solution was heated previously at about 30℃ before the addition. The bottle with the sample was shakened for one hour by shaking machine. For "Onji" with humus, it was necessary to add 30〜50 ml. of 30% H_2O_2 to the soil on the water bath, to decompose humus before the addition of oxalic acid. Solubility of various fresh minerals by 5% oxalic acid was found almost negligible.