SOILS FERTILIZERS. 423 



of soil and subsoil water vary in the same wide limits as the ratio between 

 atmospheric water that penetrates into the soil and that which evaporates. 

 The content of these elements in the subsoil water is said to vary with the 

 locality, from season to season and from year to year. 



The continuous introduction of sulphur from the atmosphere is considered 

 a necessary condition for vegetation and soil evolution, on account of the rapid 

 impoverishment of the soil in sulphur by weathering and leaching. In soils and 

 subsoils in which no underground water is formed the accumulation of sulphur 

 and chlorin compounds due to atmospheric precipitation will, in a brief period, 

 from a geological view-point render a soil too saline for most cultivated crops. 

 On tlie other hand, the formation of a relatively insignificant quantity of sub- 

 soil water is sufficient to prevent an accumulation of these compounds. 



Compiled analyses are reported to show that the cultivated crops are rela- 

 tively rich in sulphur, which, expressed as SOs and referred to air-dry mat- 

 ter, ranges in the grain of cereals from 0.29 to 0.45 per cent, and in straw 

 0.26 to 0.55 per cent, while clover hay contains 0.41, lucem hay 0.50, peas 0.45, 

 beans 0.58, soy beans 0.85, turnips 1.85, and cabbage 2.05 per cent. 



It is concluded that in certain cases an impoverishment of the soil as to sul- 

 phur is possible, and, consequently, that sometimes for a succession of heavy 

 crops the application of fertilizers containing sulphur becomes necessary. Ap- 

 parently, the circulation of chlorin consists chiefly in a mechanical transport 

 between the land, the seas, and the atmosphere, while the circulation of sul- 

 phur is much more complicated ; on the one hand, passing continuously from 

 Inorganic to organic form and vice versa, and on tJie other hand, undergoing 

 oxidation and reduction, largely by bacterial activity. 



The occurrence of arsenic in soils, J. E. Greaves {Biochcm. Bui., 2 (WIS), 

 No. 8, pp. 519-52S). — From a study of the arsenic content of many western 

 orchard soils the author concludes that " some virgin soils contain arsenic In 

 appreciable quantities which comes from the decay of the native rocks. Many 

 cultivated orchard soils contain it in large proportions, but there is no uniform 

 relationship between the total quantity of arsenic in different soils and the 

 water-soluble arsenic of these soils. A soil containing over 100 parts per mil- 

 lion of total arsenic contained much less water-soluble arsenic than did a soil 

 carrying only 5 parts per million of total arsenic. The solubility of the arsenic 

 found in a soil is governed largely by the salts in the soil and the form in which 

 the arsenic is applied. 



" Different portions of the same soil, to which equivalent quantities of various 

 so-called insoluble arsenical compounds had been added, showed great dissimi- 

 larities in water-soluble arsenic content. The portion to which Paris green was 

 added contained four times as much water-soluble arsenic as did a portion of 

 the same soil to which an equivalent quantity of lead arsenate had been applied. 

 Arsenic trisulphid, when first applied to soil, is less soluble than lead arsenate, 

 but as time progresses, at least in some soils, the arsenic trisulphid becomes 

 more soluble. For this reason lead arsenate is probably safer than any of the 

 other arsenical insecticides." 



The influence of arsenic upon the biological transformation of nitrogen in 

 soils, J. E. Greaves (Biochcm. Bui., S {WIS), No. 9, pp. 2-16; ahs. in Jour. 

 Chem. Soc. [London], 106 (191^), No. 616, I, p. »57).— Experiments were con- 

 ducted to determine the effects of different amounts of sodium arsenate, zinc 

 arsenite, lead arsenate, arsenic trisulphid, and Paris green on the ammonification 

 and nitrification of dried blood in a sandy loam soil rich in calcium and iron, 

 and abundantly supplied with plant food with the exception of nitrogen, 

 33788°— No. 



