AGRICULTURAL BOTANY. 425 



from the soil and plant, and that absorption of water vapor, by soil was but 

 slightly increased (about 98 lbs. per acre). The evaporation of water from 

 the soil and plant was not influenced by kainit fertilizing, either absolutely or 

 relatively, so long as there was no increase in yield of crop. When there was 

 an increase in yield, however, there was a reduction in the relative utilization 

 of water. This, however, is an effect not confined exclusively to potash salts, 

 but is shown by fertilizing materials in general when an increase of yield 

 results from their use. 



The composition of muds from Columbus Marsh, Nevada, W. B. Hicks 

 {U. 8. Geol. Survey, Prof. Paper No. 95-A {1915), pp. 11, fig. 1).—An investi- 

 gation of these muds as a possible source of potash is reported. 



Analyses of water from wells sunk to varying depths in the muds, as well 

 as of surface muds, indicate the presence of small amounts of potash associated 

 with large amounts of sodium chlorid and other salts, principally sulphates, 

 carbonates, and borates. The high percentages of soluble salts in the muds 

 usually corresponded to low percentages of potash in the salts. " It is believed 

 that a large part of the potassium in the muds has been absorbed from sur- 

 rounding or percolating solutions and is held in a loosely combined form, 

 probably by colloids. Such a conclusion offers an explanation of the apparent 

 disappearance of the potassium from the brines and saline deposits of the 

 desert-basin regions." 



The manufacture of fluosilicates and their use, A. Hutin (Rev. Chim. 

 Indus., 25 {1914), No. 295, pp. 188, 189; ahs. in Jour. Soc. Chem. Indus., 34 

 {1915), No. 2, p. 93). — Attention is called to the fact that most mineral phos- 

 phates contain fluorin, which in the manufacture of superphosphate is con- 

 verted into hydrofluosilicie acid and allowed to go to waste. A simple and 

 cheap method of preventing this waste is described. The method consists 

 essentially of drawing the gases from the superphosphate chamber through a 

 lead-lined tower in which they meet a spray of brine, resulting in the forma- 

 tion of sodium silicofluorid, which can be separated by filtration. 



Contributions of the chemist to the fertilizer industry, H. W. Wallace 

 (Jour. Indus, and Engin. Chem., 7 {1915), No. 4, p. 281). — ^This is a brief state- 

 ment of the role which the chemist has played in building up the fertilizer 

 industry. 



AGRICULTURAL BOTANY. 



ITutritional physiology of higher plants, V. Geafe {Erndhrungsphysiolo- 

 gisches PraktiJcum dcr hoheren Pflanzen. Berlin: Paul Parey, 1914, pp. X+494, 

 figs. 186). — ^This book is intended as an aid to laboratox-y work, and its field 

 lies somewhat between that of the usual laboratory courses in plant physiology, 

 on the one hand, and that of a methodology for biochemical investigations, on 

 the other, dealing more particularly with the chemical and physical phases 

 of the nutritional physiology of plants. It is intended primarily for the use of 

 scientific investigators, and secondarily for scientific agriculturists and stu- 

 dents. It covers a wide range of technique related to the factors, processes, 

 and products concerned in higher plant life. 



Nutritive exchanges in plants. The role of protoplasm, P. MAzfi {Compt. 

 Rend. Acad. Sci. [Paris], 159 {1914), No. 24, pp. 809-811).— In order to test the 

 role of protoplasm in the nutritive exchange of plants with their external 

 medium, the action of heat on maize and of chloroform on beets was employed. 

 The effects as tabulated are held to show that it is the protoplasm which 

 regulates the nutritive relations of the plant with the external medium, inde- 

 pendently of osmosis. 



