22 



EXPERIMENT STATION RECORD. 



covered by the experiments. The losses of plant food in the drainage were as 

 follows : 



Losses of plant food in drainage icater from loam and sandy soils in pounds 



per acre. 



On a new method of measuring the capillary lift of soils, C. J. Lynde and 

 H. A. Dupii6 (Jour. Amer. 8oc. Agron., 5 {1913), No. 2, pp. 107-116, figs. 5).— 

 The apparatus used in the method proposed, which is similar to that of Aske- 

 nasy (E. S. R., 7, p. 19), consists essentially >f an ordinary glass funnel 4 cm. 

 in diameter connected with a thick-walled capillary tube about 90 cm. long by 

 means of a piece of rubber tubing. This joint is water sealed by means of " a 

 glass tube, 2 cm. in diameter and 15 cm. long, closed at the bottom with a rub- 

 ber stopper through which the capillary tube passes. The seal is filled with 

 water and prevents air from entering about the rubber tube." 



In using this apparatus a 6-gm. sample of soil is allowed to stand over night 

 in water. It is then boiled for a short time to expel air. The funnel is fitted 

 with a cotton cloth filter 2 cm. in diameter. A cup of a centrifuge is filled with 

 distilled water previously boiled to expel the air and the funnel with its filter 

 is placed in the cup, being supported by the rim of the cup. Part of the hot 

 mixture of soil and water is poured into the funnel and the soil is settled by 

 centrifuging. This process is repeated with more soil and water until the soil 

 is well above the edge of the cloth filter. The capillary tube with the rubber 

 tube attached is then filled with water previously boiled to expel air, and the 

 funnel is inserted in the rubber tube, care being taken in doing this not to allow 

 air to enter the funnel or tube and to avoid disturbing the soil. The lower end of 

 the capillary tube is placed in a cup of mercury and the water seal is filled 

 with boiled distilled water. When evaporation sets in from the surface of the 

 soil in the funnel the mercury rises in the capillary tube and the maximum 

 capillary lift is found by multiplying the length of the mercury column in centi- 

 meters by 13.6 and adding the length in centimeters of the water column from 

 the top of the mercury column to the middle of the soil layer. 



The advantages claimed for this method are that the moisture moves through 

 a very short column of wet soil, reducing friction to a minimum; the time 

 required to make a measurement is greatly reduced ; and the final measurement 

 is a fairly accurate index of the capillary lift of the soil, being approximately 

 three times that measured by the old method. By this method the capillary 

 lift of soil constituents was found to be greater the finer the grains, and a com- 

 parison of the calculated and observed lifts showed that the observed lifts fell 

 between the calculated limits in every case except that of clay. The capillary 

 lift of clay was measured under pressures equal to, gi*eater than, and less than 

 one atmosphere, and the results showed that the capillary lift observed by this 

 method is limited by the pressure of the atmosphere and that, therefore, the 

 maYlmnm lift under a pressure of one atmosphere can not exceed 34 ft. 



