SOILS FERTILIZEES. 821 



with the jilkali carhonates. The solubility ... is greatly increased by the 

 addition of carbon dioxid to the solution, tlie solubility being less at the higlier 

 temperatures. [It] passes through a maximum as the concentration of sodium 

 chlorid increases, but in the presence of carbon dioxid this solubility is de- 

 pressed by addition of sodium chlorid. The solubility in solutions of sodium 

 sulphate is increased by increasing the concentration of the latter." 



The solubility of calcium carbonate in certain aqueous solutions, F. K. 

 Cameron and W. (>. KomNsoN (A?>«. in Science, n. set:, 26 {1901), No. 660, p. 

 24O). — This is an abstract of a paper read before the Toronto meeting of the 

 American Chemical Society. 



The authors conclude that " calcium carbonate is much more soluble in po- 

 tassium sulphate solutions than in potassium chlorid solutions. In solutions 

 of potassium chlcn-id it passes through a maximum. When the system is satu- 

 rated with carlx)n dioxid at atmospheric pressure the calcium carbonate is again 

 more soluble in the more dilute potassium sulphate solutions than in those of 

 potassium chlorid, where again it passes through a maximum. In the more 

 concentrated potassium sulphate solutions syngenite is formed." 



The solubility of calcium carbonate in aqueous solutions of potassium 

 chlorid and potassium sulphate at 25°, F. K. Cameron and W. O. Komnson 

 (Joio: 7^7(//.s\ Chciii., 11 (IDOl), Xo. ,S. pp. 577-580).— This article is based upon 

 data which are also reported in the article noted above. 



The solubility of certain salts present in alkali soils, F. K. Cameron, J. M. 

 Bell, and W. O. Robinson {Jour. Phys. Chcm., 11 {1907), No. 5, pp. 396-420, 

 figfi. 6). — This paper reports the results of a study of solubility in 9 combina- 

 tions of salts occurring in alkali soils, namely, (1) calcium chlorid and sodium 

 chlorid, (2) sodium chlorid and sodium sulphate, (3) sodium chlorid, sodium 

 sulphate, and calcium sulphate, (4) sodium chlorid and calcium carbonate, (.5) 

 sodium chlorid, calcium carbonate, and carbon dioxid, (6) sodium sulphate and 

 calcium carbonate. (7) sodium sulphate, sodium chlorid. and calcium carbonate, 

 (8) sodium sulphate, sodium chlorid. calcium sulphate, and calcium carbonate, 

 and (!)) sodium suU)hate. sodium chlorid, calcium sulphate, calcium carbonate, 

 and carbon dioxid. These are considered typical systems encountered in study- 

 ing the chemistry of alkali in soils of arid regions, and the conditions were 

 made to approximate as nearly as possible those prevailing in the field. 



The results obtained are discussed in some detail and the methods used are 

 described. " Incidentally it has been shown that solid calcium chlorid is not 

 to be expected normally as a component of alkali soils, nor is anhydrite to be 

 expected normally where the salts of sodiinn and calcium predominate. Fur- 

 ther, it has been sliown that under certain conditions of concentration a 

 double sulphate of calcium and sodium can exist. At higher temperatures this 

 double salt is the well-known mineral glauberite; at lower temperatures the 

 double salt has been shown to have the composition 2CaS04.3NaS04." 



A contribution to the chemistry and physiological action of the humic 

 acids, E. A. Robertson, J. C. Irvine, and Mildred E. Uobson {Bio-Vliciii. Jour.. 

 2 {1907), No. 10, pp. Ji5S-J,79, pis. 2. fif/s. 3; ahs. in Jour. Sor. Chcm. Indus., 

 26 {1907), No. 23, p. 12'i8). — Studies of the chemical com]H)sition of various 

 samples of natural and artificial humic acids and of the effect of the acids and 

 their salts on fungi are reported. The results are sununarlzed as follows: 



"(1) Natural humic acid obtained from peat varies greatly in composition, 

 according to the method of preparation. When prepared through the ammo- 

 nium salt the percentage of carbon is lower, and that of nitrogen is higlier, 

 than when prepared from the potassimn salt. 



"(2) Natural Inunic acid contains more combined nitrogen and less niefh- 

 oxyl than the artificial forms. 



