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Devices for Percolating Air Through Soils 



There is on the market a standard set of appliances adapted 

 to the study of soil physics. Simple experiments to demon- 

 strate the percolation of air and water through soils, capillarity, 

 water retaining capacity, etc., are of value in connection with the 

 study of respiration. An appliance is often used in connection 

 with the experiments relating to the percolation of air through 

 soils which is defective and unreliable, and the writer has made 



Fig. 4. Device for percolating air through soils. 



use for a number of years of a form similar to that shown in 

 figure 4. The principles underlying the present device for 

 demonstrating the percolation of air through soils are not per- 

 fect, but the defects are of more theoretical than practical impor- 

 tance and could be easily remedied if necessary. The device 



