Transactions of The Royal Society of Canada 



SECTION III 

 Series III SEPTEMBER 1915 Vol. IX 



On Osmosis in Soils. 



By C. J. Lynde, Ph.D., Professor of Physics, and J. V. DuPRÉ, B.A., 



Research Assistant under the Dominion Grant for Agriculture, 



Macdonald College. 



(Presented by Prof. H. T. Barnes). 



(Read at May Meeting, 1915). 



The results given in previous papers^ indicate (1) that clay 

 subsoil acts as a partial semi-permeable membrane when prepared 

 as described below: (2) that water moves through the soil from points 

 at which the soil solution has a low salt content to points at which 

 it has a high salt content. 



THE object of THIS WORK. 



Thé object of the work herein described was to apply many 

 different tests to these phenomena in order to gain new evidence 

 as to whether or not water does move through the soil from a weak 

 soil solution toward a strong soil solution and whether or not this 

 movement is due to osmosis. 



Unless otherwise stated, the soil used in all these tests was pre- 

 pared as follows: 30 g. of moist clay subsoil was placed in a shaker 

 bottle with 150 c.c. of distilled water and 10 drops of strong ammonia. 

 It was shaken for 2 hours and then boiled gently for half an hour to 

 expel the ammonia. 



This method of preparation was adopted after experiments had 

 been made to determine (1) whether the soil should be shaken with 

 ammonia or without ; (2) the minimum effective quantity of ammonia ; 

 (3) the minimum effective time of shaking; (4) whether the soil mud 

 should be boiled to expel ammonia. 



In each experiment duplicate tubes were set up as shown in Fig. 1 , 

 and the soil solution was allowed to rise in the measuring tubes until 

 the maximum pressures had developed. 

 1 See papers listed at the end of this paper. 



Sec. Ill, 1915— 5a 



