1030 EXPERIMENT STATION RECORD. 



The causes of injury to plants by alkali are explained. "Field work 

 in the alkali soils at Billings Las shown that when the concentration 

 of the salts in active solution in the soil moisture is as high as 1 per 

 cent the limit of most cultivated plants is reached." The injury is due 

 to the fact that when "the concentration of the soil solutions becomes 

 greater than a 1 per cent solution the osmotic pressure of the solution 

 outside of the cell is greater than the pressure of the solution inside 

 the cell and the cell is unable to absorb water." (See also abstract of 

 Wyoming Station Bulletin 39, p. 1025.) 



"It has been found that the solid grains of soil have the remarkable power of 

 absorbing or concentrating a portion of the salts on their surface and thus with- 

 drawing them from active solution. This is of the greatest practical importance, 

 as otherwise the soil moisture would quickly become saturated with salts and ren- 

 dered totally unfit for agricultural plants. As a matter of fact, in consequence of 

 this condensing power, in no case was the concentration of the soil moisture found 

 to exceed 3 per cent, although the salts were quite soluble and were crystallized 

 out on the surface of the ground." 



Soil temperatures, L. U. Carpenter et al. (Colorado Sta. Bid. 49, 

 pp. 55-63, Jig. 1). — The weekly averages of soil temperatures (recorded 

 by two sets of thermometers) down to depths of 6 ft. are reported, and 

 the effect of irrigation on the temperature of the soil is discussed. 



" [One set of soil thermometers was so situated in a grass plat] that the irrigation 

 of the lawn flooded to a depth of some inches the ground where the instruments 

 were placed, and the irrigation was continued long enough to saturate the ground 

 underneath. 



" The temperature at a depth of 6 ft. had been nearly uniform at 62° for a number 

 of weeks before the date of irrigation on August 12. 



"With the application of water it is noticed that the temperature immediately 

 rises, reaching a temperature of 71° almost immediately after. The temperature fell 

 almost immediately after the irrigation, so that during the next 3 days it had fallen 

 to 64.5°. On August 16 the irrigation was repeated, and this time the effect of this, 

 added to the effect of the first, was to increase the temperature to 75.5°. The tem- 

 perature dropped rapidly to 69°, aud then dropped gradually, not again reaching 62° 

 until October. The effect of irrigation on the plat of ground and its vicinity was 

 felt for more than a month. 



"The effect on the temperature at 2 ft. and at 3 ft. in depth was much the same. 

 At the first irrigation the temperature at 2 ft. was increased over that at the lower 

 depths. At the second irrigation the effect on the deep thermometers was almost as 

 great as upon the 2- ft. thermometer. 



"For the depths less than 2 ft. the diurnal lluctuation ls'marked. . . . The shal- 

 lower thermometers also show the cooling effect from evaporation so much that their 

 temperatures fell below the deeper ones." 



The air and the methods of hygrometry, A. and H. Wolpekt (Die Luft und die 

 Meihoden der Hygrometrie. Berlin: W. #• S. Loewenthal, 1899, pp. XXII-\-3SS, figs. 108). 



The maximum amount of chlorids in sea air, A. Gactier (Compt. Rend. Acad. 

 Sci. Paris, 128 (1S99), No. 12, pp. 715, 716). — The author found in the air of the Atlan- 

 tic Ocean 0.00462 gm. of chlorin, corresponding to 0.022 gm. of sodium chlorid per 

 cubic meter of air. 



The absence of iodin in the free state or in the form of iodated gas in the air 

 of the region of Toulouse, F. Garrigou (Compt. Bend. Acad. Sci. Paris, 128 (1899), 

 No. 14, pp. 8S4, 885). 



