1917] SOILS FERTILIZERS. 323 



The composition of some Thomas meals, C. J. van Raaij ( Verslag. 

 Landbouwk. Onder::oek. Rijkslandbnuwproefstat. [Netherla7ids'\, No. 20 {1911), 

 pp. 27-34). — Analyses and tests of samples of Thomas meal imported into Hol- 

 land after the oxitbreak of the European war are reported. They are divided 

 into those containing from 7 to S per cent of phosphoric acid, considered low- 

 sni-ade, and those containing 15 to 19 per cent. A characteristic of both types 

 of meal was a high content of silica, which is attributed to the addition of sand 

 during manufacture to increase the citrate .solubility. The contents of alumina, 

 magnesia, and calcium oxid were somewhat above normal in the low-grade 

 meals and they also contained considerable iron. These constituents were 

 present in normal quantities in the higher-grade meals. 



The higher-grade meals are considered to be by-products of processes similar 

 to the Thomas process, and their chemical composition should not interfere 

 appreciably with their agi'icultural value. The use of low-grade meals, on the 

 other hand, is considered uneconomical, especially on account of their high iron 

 content. 



The assimilation of phosphoric acid from phosphorites by cereals, I. V. 

 fAKUsHKiN {Iz RezuVt. Veget. Opytov Lab. Rabot {Rec. Trav. Lab. Agron.), 

 Moslcov. Selsk. Khos. Inst., 10 (1914), pp. 66-84, figs. 6; Izv. Moskov. Selsk. 

 Khos. Inst. (Ann. Inst. Agron. Moscou), 22 {1916), No. 1, pp. 66-84, figs. 6).— 

 Tests of certain Russian phosphorites on wheat in sand cultures showed that 

 these phosphorites were from 60 to 70 per cent as effective as superphosphate. 

 From 10 to 15 per cent of the phosphoric acid was soluble in alkaline ammoniiim 

 citrate which dissolves only traces of phosphoric acid from ordinary phos- 

 phorites. 



The assimilation of phosphoric acid of phosporite by plants under different 

 conditions of nutrition, P. V. Chirikov (T. V. Tchirikov) {Is. RezuVt. Veget. 

 Opytov Lab. Rabot {Rec. Trav. Lab. Agron.), Moskov. Selsk. Khoz. Inst., 10 

 {1914), PP- 149-171, figs. 4i I^v. Moskov. Selsk. Khoz. Inst. {Ann. Inst. Agron. 

 Moscou), 22 {1916), No. 1, pp. 149-171, figs. 4)- — Experiments are reported 

 which showed that Spcrgula arvensis, TrifoUum resupinatum, Vicia faba, and 

 Onobrychis sativa grown with phosphorite contained appreciable amounts of 

 phosphoric acid, while Andropogon sorghum,, Panicum gennanicum, Zea mays, 

 and Camelina sativa showed little power of assimilation of phosphorite. The 

 yields of cereals were greater with small amounts of lime in solution than with 

 large. The plants which utilized the phosphorites best appeared least sensitive 

 to changes in the composition of the nutritive solution. 



The value of diphosphate, I. V. Iakushkin (J. V. Jakouchkine) {Iz 

 RezuVt. Veget. Opytov Lab. Rabot {Rec. Trav. Lab. Agron.), Moskov. Selsk. 

 Khoz. Inst., to {1914), pp. 51-65, figs. 6; Izv. Moskov. Selsk. Khoz. hist. {Ann. 

 Inst. Agron. Moscou), 22 {1916), No. 1, pp. 51-65, figs. 6). — It is pointed out 

 that the phosphoric acid of precipitated phosphate (disphosphate) is much 

 more soluble in water than that of Thomas slag. Experiments are reported 

 which show that on the rich black soils of southern Russia the precipitated 

 phosphate is equal, and in some cases superior, to superphosphate for millet and 

 sugar beets. 



Causes influencing' the solubility of difficultly soluble phosphates in 

 citric acid, A. Atta {Ann. Chim. Appl. [Rome^, 6 {1916), No. 3-4, pp. 119-131, 

 fig. 1). — Continuing studies previously reported (E. S. R., 36, p. 626), experi- 

 ments on the influence of salts of manganese, iron, aluminum, and magnesium 

 in mineral phosphates and phosphatic slags on the solubility of the phosphoric 

 acid therein are reported. 



It was found that the secondary constituents of phosphatic slag may be 

 divided into two groups, (1) those which interfere with the solubility in citric 



