EXPERIMENT STATION BULLETINS. 



527 



outer two holes, two horizontally bent glass tubes of very small diameter. 

 The straight vertical tubes served the purpose of adding water to the 

 compartments and bringing the level of the water to a standard position. 

 On the horizontally bent tubes was intended to read any thermal diffusion 

 of water. The vertical tubes were either left open or closed. 



The possibility of thermo-osmose was studied in kaolin and in two 



FIG. 6. APPARATUS FOR STUDYING THERMO-OSMOTIG PHENOMENA IN SOILS. 



different kinds of clay, of different thickness of membrane. The tem- 

 perature amplitudes employed were 0°-20°, 0°- 40°, 0°-60° C. In a large 

 number of trials no thermo-osmose was observed : no movement of water 

 occurred in either direction. 



The failure of obtaining any results led to the conclusion that either 

 the method was not sufficiently perfected, or that there is no thermo- 

 osmotic phenomena in soils. In the opinion of the writer the latter con- 

 clusion is more probable. 



