Abstract
1. The total analyses were made on so-called suspensoid and emulsoid clays which were obtained from uncultivated, residual, mineral soils of various geological and petrographical origin. The results were arranged in tables according to the geological classification of the soil. 2. As compared with the results now obtained, the formerly reported results indicate that the alluvial, rice-field soil colloids are characteristic in composition in that they are markedly poorer in alumina and more rich in silica and iron oxide than the other sorts of colloids. The alluvial soils are generally poor in colloidal material. Most of the surface soils contain almost no emulsoid clays. 3. Comparison of the emulsoid clay with the suspensoid clay from the same soil, shows in general, a marked decrease in strong bases, titana and manganese oxide ; and increase in loss on ignition. It also indicates a slight decrease in silica and a slight increase in sesquioxides with many exceptions. 4. The diluvial soil colloids, especially the colloids from the bolcanic ash soil, contain a relatively large amount of ignition loss and of alumina. 5. Next to the alluvial soil colloids, the tertiary, mesozoic and paleozoic colloids are generally rich in silica. The colloids originated from sandstone, shale, conglomerate, quartzite and granitic soils contain a large amount of silica, whereas the colloids from the volcanic ash soil have comparatively its small quantity. 6. The variation in amount of alumina contained in the residual soil, is markedly small, and it may be assumed as fairly constant. 7. The variation in lime content seems also to be small. However, the colloid from limestone contains a large amount of lime. 8. The soil colloids originated from those rocks which are remarkably rich in magnesia -i. e. talc schist, chlorite schist, pyroxenite, amphybolite etc.-show the presence of a large amount of magnesia. 9. The molecular ratios, SiO_2/R_2O_3 and SiO_2/Al_2O_3 of the emulsoid clay are generally a little lower than that of the suspensoid clay. The approximate values will be seen in the following table. [table]
