748 EXPERIMENT STATION RECORD. 



deposit of c;irl)onate uf liine "found almost everywhere on the under sides of loose* 

 stones or in the upper portions of basaltic outcrops when covered with loose stones, 

 sand, soil, etc.," and the other a deep-blue film consisting of salts of iron and man- 

 ganese, occurring on the surface of the less recent lava. 



The author concludes from his study of the water resources of the region that "the 

 surface water supply at present available is largely wasted, and can by proper econ- 

 omy be made to yield 2 or 3 times the service now obtained from it." He believes 

 "it is practicable to use for irrigation the entire summer flow of all the streams 

 reaching the Snake Elver Plains." Another means of more fully utilizing the water 

 supply is by constructing reservoirs, suitable sites for which have been located. 

 There is evidence that the supply may be still further largely increased by the 

 sinking of properly constructed artesian wells. 



Studies on humus, T. Schloesing {Compt. Rend. Acad.Sci. Paris, 135 {1903), No. 

 in, pp. noi-iiO-')). — Using methods similar to those employed in the study of the dis- 

 tribution of iron oxid in soils (E. 8. R., 14, p. 18), the author found that in humus 

 soils the proportion of organic matter adhering to the soil particles increases as the 

 size of the particles decreases, i. e., from 0.4 per cent in the coarse sand particles to 

 5.4 per cent in the clay of one soil, and from 0.15 per cent in the coarse sand to 4.14 

 per cent in the clay of another. The method used in separating the different grades 

 of ])articles is described. Potassium chlorid (5 gm. per liter) was successfully used 

 to precipitate the clay particles without simultaneous precipitation of alkaline humates. 

 The organic matter adhering to the particles was determined by combustion with 

 copper oxid in the usual way, it being assumed in the calculation of the results that 

 the organic matter contained 50 iier cent carbon. The author advances the theory that 

 the organic matter adhering to the soil particles has been precipitated ujjon them 

 from the soil solutions and is alternately dissolved and precipitated as the soil solu- 

 tions become diluted or concentrated. If this be true, it constitutes an important 

 reserve or store of plant food. 



A contribution to the study of tropical soils, J. D. Kobus and T. Mark {Jour. 

 Ijmdir., 50 {1002), Xo. 4, PP- -289-302). — This article briefly discusses the value of 

 chemical analysis as a means of determining the fertilizer requirements of soils, review- 

 ing investigations on the subject, and reports the results of analyses of the solutions 

 obtained by 5 successive extractions of 2 Javanese soils of volcanic origin with 2, 4, 

 and 8 per cent hydrochloric acid, boiling for 2 hours, in each case, and by 24 hours 

 extraction with cold concentrated hydrochloric acid. The proportion of solvent used 

 was larger than that ordinarily employed. The author concludes that the 2 per cent 

 acid extract gave results most accurately indicating the available potash and phos- 

 phoric acid of the soils. 



Banana soils of Jamaica, II, H. H. Cousins {Bid. I)cpt. Agr. Jamaica, 1 {1903), 

 No. 1, pp. 1-17) . — A preliminary analysis of some of the banana soils of Jamaica has 

 been previously announced (E. S. R., 13, p. 633). The work has been continued, and 

 in the present report physical and chemical analyses are given of about 30 of the 

 most prominent l)anana soils of Jamaica. Fertilizer experiments were carried out on 

 the soils examined. The results indicate that as a whole commercial fertilizers need 

 not be used on Jamaica soils in the production of bananas for many years to come. 

 The soil analyses, considered in the light of subsequent fertilizer experiments based 

 on them, are believed to show that the analyses alone are sufficient evidence on 

 which to base practical advice as to soils for banana cultivation. 



Greensand marl, A. L. Parsons {Mineral Resources of the United States. Dept. 

 Interior, f. ,S'. Geol. Survey, 1901, pp. 823-827). — This article briefly discusses the 

 occurrence and classification of greensand formations and tlie production and use of 

 the marls. Compiled analyses of characteristic marls from New Jersey, Maryland, 

 and N'irginia, and a bibliography are given. 



Further contribution to the question, Can plant analysis show the ferti- 

 lizer requirements of soils? C. von Seelhorst, H. Behn, and J. Wilms {Jour. 



