THE SOIL 117 



or forty-eight hours, or until the water has risen to the 

 top of the soil, to ascertain the weight of water absorbed. 

 This should be calculated to 100 parts of soil. If 

 necessary, water must be added to the saucer from time 

 to time in order to ensure that the soil in the tube is 

 always in contact with water. Comparisons should be 

 made of the weight of water absorbed by sand, clay, and 

 garden-mould ; sand absorbs the least and clay the 

 most water. 



The following experiment will demonstrate the 

 influence of capillarity in bringing water from the sub- 

 soil to the surface. Take two large pots, or two tubs or 

 deep boxes, fill one with soil in the ordinary way for 

 sowing seeds, as described on page 15. Fill the other 

 in the same way, but in filling place a layer of fine wire- 

 gauze horizontally across the box or tub, about 4 or 

 5 inches below the surface of the soil. This gauze will 

 serve to interrupt the capillary connections between the 

 subsoil and the surface. Sow seeds of barley, grass, or 

 other shallow-rooted plants (more than one kind may 

 be used) and place the boxes, pots, or tubs side by side 

 out-of-doors. Give a little water until the plants are 

 established, and then leave them dependent on the 

 rainfall. Record the rate of growth and development of 

 the two sets of seedlings, and determine the effect of 

 restricting the capillary flow of water. In a very wet 

 season the pots, etc., should be screened from excessive 

 rainfall. 



Take a small ball of clay this may be obtained 

 from the subsoil of the garden let it dry in the air for 

 a day or two, and then put it into the kitchen fire for 



