WATER SOILS. 127 



definite relation can be found, then the determinations of the capillary riwe in dry 

 soils are without value. (4) It is consequently important that investigators in this 

 line should determine the limit of capillary movement in moist soils in which they 

 are interested, both to obtain reliable data regarding the extent of capillary action 

 and to determine the ratio of capillary action in dry and moist soil. (5) The true 

 limit of capillary movement may be determined by finding the limiting height of a 

 soil column from the upper surface of which evapoi-ation proceeds at a finite, con- 

 tinuous, and approximately uniform rate, the supply being obtained from a reservoir 

 at the l)ase of the column. The rate of evaporation may be determined directly by 

 weighing the system, or less accurately by measuring the height of the water in the 

 reservoir. (6) For Sea Island soil we have found the capillary rise in dry soil to be 

 only 37 cm., while the limiting value of cax^illary movement in a vertical column of 

 moist soil is not less than 165 cm., or 4.5 times as great. (7) The rate at which water 

 can be supplied at a given point by capillary action through soil columns of various 

 heights is of fundamental importance Avhen the plant is dependent upon capillary 

 movement for its water supply. This determination can readily be made by the 

 methods described." 



Filtration of suspended clay from soil solutions (pp. 31-40, fig. 1). — The difficulty of 

 securing satisfactory filti'ation of solutions containing suspended clay obtained in 

 soil analysis is pointed out, and a light, portable apparatus, consisting essentially of 

 an unglazed porcelain filter tube connected with a filter pump, which has been 

 devised and used with success in the Bureau of Soils, is descrilted. 



Contribution to the study of tlie solution of phosphoric acid, in the soil solu- 

 tions, (t. Patukel {Ann. Agron., 28 {1902), No. 8, pp. 385-398).— From the results 

 of studies of soils of different kinds, with and without the addition of superphos- 

 l>hates, following in the main the method proposed by Schloesing (E. S. R., 11, p. 

 S21) , the author concludes that the generally accepted view that the greater activity 

 of superjihosphate as a fertilizer is due to the fact that the phosphoric acid is widely 

 diffused in the soil and precipitated in a fine state of division, which i-endert it easily 

 assimilable hj plants, is not true in all cases, especially in light, sandy soils poor in 

 lime and having little absorptive power for the superphosphate. He found that in 

 such soils a portion of the superphosphate added was still solu])le after the lapse of 

 several months. The results confirm those reported by Schloesing in indicating that 

 ])lants take up all of their phosphoric acid in soluble form, and that the soil solutions 

 play an important role in sui:iplying this soluble phosphoric acid for the use of the 

 plant. 



On a method of determining' the heat generated when soils are moistened, 

 A. MiTsciiEKLicii {Landw. Jahrh., 31 {1902), No. 4,PP- 577-604, figs. 5).— In continua- 

 tion of a previous article (E. S. R., 13, p. 833) the author describes a new drying 

 apparatus for use in his method based on the heat generated on moisten hig soils 

 {Benetziingsu'dnne) and I'eports a large number of experiments on different kinds of 

 soil to test the accuracy of the n^ethod. 



Soil survey in Salt River Valley, T. H. Means {Arizona Sta. Bid. 40, pp. 

 .'87-330, j)ls. 4, figs. 8, maps 3) . — A reprint from the report on field operations of the 

 Division of Soils of this Department for 1900 (E. S. R., 13, p. 924). 



Soil investigations, F. T. Snuxr {Canada Expt. Farms "Rpts. 1901, pp. 140-152). — 

 ]\liscellaneous investigations are reported, including chemical analyses (total and 

 available constituents) of 2 samples of soils from British Columbia, 2 from Ontario, 

 5 from Nova Scotia, and 1 from Prince Edward Island, with suggestions as to their 

 fertilizer requirements and treatment. Examinations of several soils with reference 

 to availaVjle lime and a study of the relation of cover crops and cultivation to soil 

 moisture are also reported. The observed losses of water from the soil were much 

 larger in that under crop (clover) than in that which had been cultivated. 



The sampling of soils, J. W. Leather {Jour. Clicm. Soc. \_London], 81 {1902) , No. 



