SOILS FERTILIZERS. 215 



different soils in dry and in wet localities, and as influenced by deiJtb, color 

 and texture, fei'tilizers, and cultivation, are reported. 



Soils in a wet locality maintained a lower temperature than those in a dry 

 locality. This is attributed to the cooling effect of the rainfall with its subse- 

 quent evai)oratiou, to direct sea breezes, and to the absorption of radiant heat 

 by clouds. 



The temperature of the soil at 3 in., at G a. m., was 72° F. and increased to 

 a maxiujum of 91° at 1 p. m. There was a quick drop after sunset. The 

 temperature at 6 in. remained more constant, and was lower during the day 

 than at 3 in. but higher at night. "At a depth of 1 ft., the temperature re- 

 ii'.ained nearly constant during the day, but it was 2° lower at night than during 

 the day. The maximum temiierature was 85°. At a depth of 2 ft., the tempera- 

 ture was 83°, and remained constant day and night. A heaNT?- shower of rain 

 lowered the temperature by 1"° on another occasion. . . . 



"The sand plat was warmer at 1 p. m. than the soils of the other plats, and 

 was cooler at 7 a. m. The temperature of the untouched sand at 1 p. m. was 

 99° ; that of the cultivated sand 90°. The temperature of the dry sand had a 

 diurnal range of 2G° ; this was considerably greater than that of the air. In 

 the case of all the plats, the effect of water in leveling up the specific heats 

 was clearly indicated. At 1 p. m. the clay was warmer than the humus plat, 

 but cooler at 7 a. m. The lime plat (untouched) was 13° cooler at 1 p. m. 

 than the sand plat (untouched), and the lime plat also possessed the lowest 

 diurnal range, which amounted to 6 to 8°." 



Cultivating, particularly forking and plowing, had a cooling effect. " Rolling 

 warmed the soil in dry weather, but had the opposite effect when the land was 

 wet. As' regards ridging or banking up, the important fact was brought out 

 that land cultivated in this manner from east to west is at least 3° warmer 

 during the day than when the soil is ridged north and south. At a depth of 

 3 in. the difference would be at least G°. The well-known fact that wind cools 

 the soil was also supported by observations made in sheltered and unsheltered 

 places. The soil under pasture was rather cooler than arable soil, and cover- 

 ing arable soil with light trash lowered the temperature during the day by 4°." 

 Soil shiided with cacao plants was 31° cooler at 1 p. m. than soil exposed to 

 the sun, and at 7 a. m. it was cooler by 3°. 



Studies of the heat conductivity of some soil types, H. Karsten (Internat. 

 Mitt. Bodenlc, 1 {1012), No. 6, pp. o2.i-5.',3, figs. 4).— Studies of the theory of 

 heat transference in masses of spherical bodies, and determinations of the same 

 in soils of different structure and moisture content, are reported, using a modi- 

 fication of the Christiansen apparatus. The theory that the heat conductivity 

 of spherical, homogeneous bodies of the same size is independent of the length 

 of their radii was substantiated. The heat transference was influenced by the 

 structure and particularly by the moisti.re content of the soil. 



Suspensions and the phenomena of absorption, S. Arrhenius (Rev. Sci. 

 \ Paris}. .',9 (1911), I, No. 15, pp. Jf-'f9-Jio6) . — This is a mathematical discussion 

 of the laws and phenomena of absoii>tion in solutions, based on investigations 

 by different authors. 



The plant and the salts of the soil, X. il. Ttilaikov (Zhur. Opytn. Agron. 

 (Russ. Jour. Expt. Landic), 13 {1912), No. 1, pp. 27-53, figs. 4; at)S. in Internat. 

 Inst. Agr. [Rome], Bui. Bur. Agr. Intel, and Plant Diseases, 3 (1912), No. 6, p. 

 1297) — It is stated as a result of studies that the water-soluble nounutrient salts 

 of the soil had a decided influence on the growth of vegetation, both in its 

 earliest and in its last stages of development. 



In the earliest stages of growth the action of the salts was physical, in that 

 it brought about a certain degree of osmotic pressure and thereby regulated 



