SOILS FERTILIZERS. 329 



describes a number of processes for treating phosphate rock In the manufacture 

 of phosphoric acid and phosphatic fertilizers, which are classified as follows : 



"(1) Acid treatment, which includes the manufacture of superphosphate and 

 phosphoric acid, (2) combined heating and acid treatment, (3) double decom- 

 position by means of a silicate or an alkali, (4) processes used in connection 

 with the steel industry, (5) processes In which the phosphorus or phosphoric 

 acid is volatilized, (6) treatment dealing with the production of two or more 

 fertilizer elements, (7) electrolysis, (8) enrichment or concentration of phos- 

 phates, (9) processes and apparatus for the mechanical treatment of phos- 

 phates, and (10) miscellaneous processes." 



A classified list of patented processes is appended. 



The Elliston phosphate field, Montana, R. W. Stone and C. A. Bonine 

 {U. S. Ocol. Surrey Bui. 580 {1915), pp. S13-3S3, pi. i).— The geology of this 

 field is described and it is stated that the phosphate rock is readily dis- 

 tinguished by its finely oolitic texture, thin bluish-white coating on weathered 

 surfaces, heavy specific gravity, and peculiar odor. A map of the field and 

 analytical data indicate tliat in the north half of the field, covering about 7 

 square miles, a bed of phosphate rock ranging in thickness from 3 to 5 ft. 

 and averaging approximately 65 per cent in tricalcium phosphate outcrops for 

 miles, which, it is estimated, contains about 70,956,032 tons of phosphate rock. 

 It is estimated that the south half of the field covers about 1.5 square miles 

 and contains, on the basis of an average thickness of 4 ft., 15,204,864 tons of 

 phosphate rock. 



Some properties of phosphorites from Seng^lei, L V. flKUSHKiN and P. I. 

 Kbivobokov (Iz RezuVt. Veget. Opytox Lab. Rabot, 9 (1913), pp. 160-166).— 

 Studies of the chemical properties of these phosphorites with reference to the 

 availability of their phosphoric acid content to gi-aminaceous plants are reported. 

 The original phosphorites and the weathered and decomposed phosphate mass 

 were studied separately. 



It was found that the latter in comparison to the former contained more 

 insoluble residue, more iron and alumina, and considerably less calcium oxid, 

 sulphuric acid, and carbon dioxid. The ammonium citrate extract of the 

 former was colorless and contained only traces of phosphoric acid, while the 

 extract of the latter was highly colored and contained important quantities of 

 phosphoric acid, a little more lime, and considerably more iron than that of 

 the former. Decomposition of the phosphorite frequently was accompanied by 

 the formation of considerable quantities of iron phosphates. 



Extraction of phosphoric acid from natural phosphates, I, A. "V. Kazakov 

 (Iz RezuVt. Veget. Opytov Lab. Rabot, 9 (1913), pp. 51-10, figs. .J).— A review 

 of the literature bearing on the subject and a theoretical chemical discussion 

 of the minimum possible sulphur trioxid and calcium oxid contents of extracts 

 of phosphates are followed by the results of quantitative analysis for sulphur 

 trioxid and calcium oxid of a series of extracts obtained by treatment of ground 

 Viatka phosphates with different amounts of sulphuric acid, the purpose of 

 which was to determine standards for optimum conditions. In this connection 

 the author proposes a rapid method for determining such standards, based on 

 qualitative tests for the presence of phosphates of calcium, aluminum, and 

 iron. 



The results show that the method of qualitative tests not only can replace the 

 method of quantitative determination of the calcium oxid and sulphur trioxid 

 but proves the presence or absence of phosphates of calcium, aluminum, and 

 iron in the extract. In drawing this conclusion the author made a comparison 

 of the standards determined empirically with those theoretically determined 

 on the basis of the chemical composition of the Viatka phosphates. The em- 



