I 



WATER SOILS. 329 



conducted outside, where tlie soils were exposed to the full intiuence of the suu and 

 wind. Temperatures were observed every hour from 8 a. m. to 8 p. m." From the 

 data obtained, i-urves are platted which show the rise and fall of temperature. The 

 humus, as a rule, reached a higher temperature than any other soil, the dark potting 

 soil standing next, followed by the open clay, heavy clay, and fine white sand. The 

 differences in the temperature are ascribed to variations in the color, the darker 

 samples being warmer than the lighter. It was also observed that the humus 

 remained steadily warmer than the other soils, thus proving an exception to the rule 

 that a soil which warms rapidly is likely to part witli the heat readily. 



On the relations of the soil solutions to the phosphates used as fertilizers, 

 T. Schloesinct (Ann. Set. Agron., 1901, I, Xo. 3, pp. 406-424). — This article records 

 observations on the solubility of tricalcium phosphate in solutions of carbon dioxid 

 of different strengths saturated with calcium bicarbonate and free from this substance, 

 and in water free from carbon dioxid. The methods of preparing the tricalcium 

 phosphate and the solution of carbon dioxid and calcium bicarbonate are described, 

 as well as those used in determining the solubility of the phosphate in the various 

 solutions. The results reported show that the phosphate dissolved in the carbon 

 dioxid solutions in proportion to their strength, l)ut that it was not sensibly soluble 

 in such solutions when saturated with calcium carbonate. The bearing of these facts 

 on the behavior in the soil of soluble phosphates applied as fertilizers and on the 

 formation of phosphate deposits is discussed. 



Sources of the constituents of Minnesota soils, C. W. Hall [Bui. Minnesota 

 Acad. Nat. Sei., 3 {1901), Xo. 3, pp. 3SS-406). — This article discusses the formation 

 of soils and the various agents which have taken part in it, and the chemical compo- 

 sition of Minnesota soils and of the rocks from which they have been derived based 

 upon analyses compiled from various sources. 



"The rocks of Minnesota are classified under 5 groups: (1) Acid crystallines, (2) 

 basic crystallines, (3) sandstones and quartzites, (4) calcareous shales, and (5) the 

 carbonates. Among these, granitic rocks and basic eruptive, which occupy large 

 areas beneath the drift in the northern and western portions of the State, furnish 

 many important food elements, particularly alkalis and alkaline earths. 



"The sandstones and quartzites among the most barren soil producers have 

 mingled with other substances their beneficent uses. The calcareous and siliceous 

 shales spring from widely divergent geologic periods and bring to the making of soils 

 somewhat different physical and chemical factors. Their influence is wholesome 

 and strengthening. Finally the carbonates come before the eye in this chemical 

 review. They yield, for soil making, carbonic acid, lime, magnesia, and small quan- 

 tities of other compounds. When the condition of a soil is reached, but a small 

 percentage of these rocks is left, l;)ut this is a substantial i^art and enters into the 

 constitution of the best soils of the State. They appear in full force in the south- 

 eastern corner of the State where stands a portion of that old glacial island, a tract 

 over which the ice did not flow during the period when all the rest of the State was 

 buried dee}) beneath the glacier." 



Solubility of gypsum in aqueous solutions of sodium chlorid, F. K. C.\merox 

 and F. D. (tardner [Froe. Soc. Prom. Agr. Sei., 1900, pp. ISO, 161). — A brief note on 

 some studies on this subject made in the Division of Soils of this Department. 



Report of the Valuiki Agricultural Experiment Station (Government of 

 Samara), 1895-96, V. S. Bogdax {St. Petirshiny : Department of .[(jrieultare, 1900, 

 pp. 1£6; aba. in Set sk. Klivz. i Lijesoe., 199 {1900), Oet., pp. 23o-l<^37) .—Among the 

 articles of interest in this report is one discussing the reclamation of alkali soils by 

 proper management of the rainfall and the culture of plants which take up large 

 amounts of alkali in their growth, and another on the influence of the character of 

 the soil on the composition of the wheat grain. Experiments showed that with the 

 increase of the salt content of alkali soils the nitrogen and ash contents of the wheat 



