Abstract
"Sirasu" is the name of the gray coarse volcanic sand accumulated here and there in this prefecture. It is used in a relatively large quantity in agriculture, especially in the stable and the compost manure. The physical composition and properties were studied. The result are summalized as follows : 1. It consist of 91.5% fine soil and 8.5% gravel on an average. 2. The fine soil contains a large qnantity of coarseand fine sand and a small quantity of silt and clay in general. 3. The specific gravity is between 2.156 and 2.328,and the mean is 2.276. 4. The pH range is from 6.5 to 5.5.
