Ilynde-uupré] 



ON OSMOSIS IN SOILS 



75 



Conclusion. The movement can be reversed and this indicates 

 that it is produced by osmosis. 



FIFTH TEST. HOW LONG WILL THE FLOW CONTINUE ? 



To determine how long the flow would continue, two tubes were 

 set up as shown in Fig. 2, and daily observations on the flow were 

 made. The test was started on Jan. 15, 1915, and at this date, May 

 15, 1915, the average daily flow is almost as great as it was at the 

 beginning. Table 5 gives: the average daily flow for each 10 day 

 period; the total flow to date in linear centimetres; the total flow 

 in c.c. ; the total flow in c.c. per square centimetre of soil surface. 



Measurement of tube 1: depth of soil 6-5 cm.; inside diameter 

 1 -4 cm.; area of cross section 1 -54 sq. cm.; m.easuring tube, 1 linear 

 centimetre = •OSS c.c; electrical resistance of the solution 2,700 

 ohms at 16°C. 



Measurements of tube 2 : depth of soil 6 • 6 cm ; inside diameter 

 1-5 cm.; area of cross-section 1-77 sq. cm.; measuring tube, 1 linear 

 centimetre =• 0385 c.c; electrical resistance of the solution 2,700 

 ohms at 16°C. 



Electrical resistance of •02N KCl with the same plates 380 ohms 

 at 18°. Electrical resistance of distilled water 50,000 ohms. 



Table 5. 

 Giving the Daily Flow in linear centimetres, the total flow to date, in 



CM. AND c.c. and THE TOTAL FLOW TO DATE IN C.C PER SQ. CM. 



Conclusion. It appears that the flow will continue for a long time. 



