818 EXPERIMENT STATION RECORD. 



rliloritl, and sodium nitrate alone or combined witb soli extract and soil gave 

 results indicating that the increased tolerance of \vlie;it seedlings to these salts 

 when used in soil as compared with water solutions and soil extract solutions 

 was due to the absorptive power of the soil for the salts. This conclusion is 

 sustained by the facts that (1) the soil as* shown by chemical analysis actually 

 exerted considerable absorptive power for certain of the salts, (2) in case of the 

 nitrate, upon which the soil exerted no absorptive power, there was no effect on 

 the tolerance, and (3) tolerance increased with the increase of the absorptive 

 power, both factors being lowest in the quartz, higher in the unmanured soil, 

 and highest in the manured soil. 



The colloids of cultivated soils, P. Eiirenberg (ZtscJir. Angnv. Cliem., 21 

 (190S) No. Jjl, p. 2122). — This is an abstract of a paper read before the eightieth 

 convention of the German Association of Naturalists and Physicians. 



Soil colloids are classitied and discussed with reference -to their properties 

 and behavior, particularly their tlocculation or coagulation under the influence 

 of low and high temperatures, drying, admixture of sand, alkali salts, lime com- 

 pounds, physiological and biological processes, ether, and carbon bisulphid. 



The article emphasizes the importance of the colloids in maintaining culti- 

 vated soils in proper condition. 



Topographic mapping' of bottom lands in Illinois, E. W. McCbary {Engin. 

 News, GO UD08), No. 13, pp. 333, 534).— This article explains briefly the methods 

 pursued by the State Geological Survey in cooperation with the U. S. (ieological 

 Survey in the topographic mapping of portions of the drainage areas of the 

 Kaskaskia, Big Muddy, and Embarras rivers. 



Superficial and agricultural geology — Ireland, No. 2. — Soils, G. H. Kinahan 

 (Dublin, IDOS; rev. in Chcm. Trude Jour., J,3 (1908), No. 1116, p. 333).— This 

 book contains in its introduction a discussion of agriculture in general and Irish 

 agriculture in particular. Particular attention is also given to the bog soils and 

 bog agriculture. 



Soil analyses, A. Amos and E. J. Russell {Jour. Southeast. Agr. Col. Wye, 

 1907, No. to, pp. 215-2JiO). — As a part of a complete survey which is to be 

 reported in full later, this article describes different classes of soils — sandy 

 soils, loams, calcareous soils, and clay soils — as typified by soils of Surrey, Kent, 

 and Lincolnshire, of which analyses are given. 



Deli soils, J. G. C. Vbiens {Meded. Deli-1'roefstat. Medan, 2 .(1908), No. 3, 

 pp. 175-236}. — Analyses of a large number of Deli tobacco soils are reported, 

 the word Deli in this case being used to cover the whole of the east coast of 

 Simiatra where the Deli tobacco is grown. 



On the weathering of soils and the value of mineralogical-petrographic 

 soil analysis, A. von 'Sigmond {Foldtani Kozlonii, 38 {1908), No. 3-), pp. 220- 

 230). — Mineralogical-petrographic studies of various Hungarian soils, the results 

 of which confirm the conclusions of Delage and Lagatu (E. S. 11., 17, p. 841) are 

 I'eported. The importance of such studies is emphasized. 



The alkali soils of the great Hungarian Alfbld, I'. Treitz {Fiihltani Koz- 

 lony, 38 (1908), No. 1-2, pp. 106-131, pi. 1, fig. /).— These soils are described 

 and their origin and composition ai'e discussed. 



The author concludes from his studies of these soils that the soluble salts 

 found in them are derived from the ash constituents of the plants produced on 

 the soil, and that the first and most necessary condition for the formation of 

 sodium compounds, particularly the carbonate, is a calcareous subsoil, carbonates 

 of the alkalis being formed by the action of calcium carbonate on the humates, 

 sulphates, and chlorids of the alkalis. During the wet season of the year the 

 carbonate of soda dissolved iu the soil moisture of the upper layers of the 



