1!»16] SOILS FERTILIZERS. 23 



but not with neutral silicates. The heat developed is proportional to the 

 acidity, indicating a chemical ratlier than a physical reaction. The acidity of 

 aluminum silicates is not only in proportion to the ratio of AI2O3 to SiOs but also 

 in proportion to the water of constitution. The greater the proportion of Vvater 

 in the silicate the more acid is the reaction. Heating and the consequent driv- 

 ing off of water of constitution in acid aluminum silicates lower the acidity 

 until all the water is removed when neutrality is reached. Ignition of acid soils 

 also destroys the acidity. Much of the harmful acidity of acid soils is due to 

 the presence of toxic acid salts of aluminum and iron. The immediate effect 

 of the addition of soluble fertilizer salts of the strong acids (nitric, hydro- 

 chloric, and sulphuric) to acid soils is to increase the soluble acid salts of 

 aluminum and iron." 



In field and laboratory experiments it was found that " soils treated for 20 

 years with acid phosphate show less acidity than soils that liave never had 

 acid phosphate. Acid soils and silicates treated in tlie laboratory with acid 

 phosphate show less soluble acidity than untreated soils and silicates." 



A new method of estimating soil acidity, in which the catalysis of ethyl 

 acetate is taken as a measure of the solubility, is described, which is used 

 together with the potassium nitrate method of Hopkins, Knox, and Pettit and 

 the limewater method of Veitch (E. S. R., 14, p. 111). 



Phosphatic fertilizers and the root system of beets, V. I. Sazanov {Zhur. 

 Opytn. Agron., 16 (1915), No. 2, pp. 14-0-165, figs. IS; abs. in Clxem. Abs., 9 

 (1915), No. 17, p. 2419). — Box experiments on chernozem soil to determine the 

 influence of superphosphate on the development of the root system of beets 

 are reported. 



It was found that soluble phosphoric acid was fixed in the layer of chernozem 

 soil to which it was added, and that no considerable amount of phosphoric acid 

 was displaced and transferred from one layer to another. Superphosphate was 

 favorable to the extensive development of beet roots, notaI:>ly in the layer of 

 soil to which it was added. No similar influence of superphosphate on the roots 

 of wheat and rye was observed. 



Phosphate rock, W. H. Waggaman (In The Mineral Industry: Its Statistics, 

 Technology, and Trade During 1914- Neio York and London: McGraw-Hill 

 Book Co., 1915, vol. 23, pp. 584-601).— This article deals with the production of 

 phosphates in the United States and in foreign countries, it being stated that the 

 world's production of phosphate rock in 1913 amounted to over 6,780,000 tons. 

 In 1914 the total output was less than 4,000,000 tons, of which the United 

 States produced 2,752,971 tons and consumed 1,823,978 tons. Methods for the 

 production of soluble phosphate from phosphate rock are briefly described, and 

 a bibliography of works bearing on the subject is appended. 



Potassium salts, S. H. Dolbeab (In The Mineral Industry: Its Statistics, 

 Technology, and Trade During 1914- New York and London: McGraio-Hill 

 Book Co., 1915, vol. 23, pp. 611-622). — This report deals with the sources and 

 production of potash salts in the United States and foreign countries and the 

 imports and exports of the same, with special reference to the years 1010 to 

 1914. A bibliography of works bearing on the subject is appended. 



Investigation of sources of potash in Texas, W. B. Phillips (Trans. Amer. 

 Inst. Mining Engin., 51 (1916), pp. 438-450, figs. 3). — This is a discussion of the 

 potash resources of Texas, from which it is concluded that the only hopeful 

 outlook for the existence of workable sources of potash salts in Texas is in the 

 direction already indicated by Udden (E. S. R., 34, p. 2G) and in the region 

 southeast of and bordering on New Mexico. 

 43795°— No. 1—16 3 



