SOILS FERTILIZERS. 623 



The estimated available phosphate rock in this region is given as 1,347,370,000 

 long tons, which, added to the estimates for areas previously surveyed, gives a 

 total tonnage for the area covered by detailed surveys to date of 2,663,290,000 

 long tons. 



The chemical analyses already made indicate that clean rock from the thick 

 workable beds usually maintains an average of over 32 per cent of phosphoric 

 acid, but this percentage is increased somewhat in the weathered outcrops of 

 the phosphate beds. The phosphate usually contains less than 1 per cent of 

 iron or aluminum and hence is of good quality for the manufacture of super- 

 phosphates. 



It is stated that too little is at present known concerning the land and the 

 marine conditions that prevailed during the process of formation of the phos- 

 phate deposits to permit the formulation of a satisfactory hypothesis. 



Note on certain phosphate deposits in western Madagascar, P. de la 

 Bathie {Gouvt. G6n. Madagascar. Feuille Mens. Inform. Agr. et Com., 1914, 

 Nos. 20, pp. 8-10; 21, pp. 10-12). — Phosphatic nodules associated with marl and 

 containing from 20 to 50 per cent of tricalcium phosphate are described. 



The effect of ensilage fermentation and animal digestion on the solu- 

 bility of phosphoric acid in phosphate rock, C. A. Mooebs (Jour. Itidus, and 

 Engin. Chem., 6 (1914), No. 6, pp. 487, //88).— Ileferring to an article by Forbes 

 and Fritz (E. S. R.. 31, p. 422), reporting results which indicate that the ensiling 

 process may be used to render floats soluble and hence available both to ani- 

 mals and plants, the author reports expeiiments made at the Tennessee Experi- 

 ment Station in which 2 lbs. of finely ground phosphate rock was mixed with 

 over 100 lbs. of corn at the time the silo was filled and the resulting silage 

 fed to cattle, with the result that although the silage was excellent in odor 

 and appearance the animals refused to eat it after a short time. Extraction 

 with 1 per cent nitric acid showed that the solubility of the phosphoric acid of 

 the phosphate rock in the dung of the animals fed phosphated silage was in- 

 creased only 3.28 per cent of the total phosiihoric acid. 



" Based on the assumption that all of the phosphoric acid was voided in the 

 dung, the data at hand indicate that a reversion of the soluble phosphoric acid 

 took place during the process of animal digestion. The general conclusion is 

 indicated that the silo does not offer a practical means of making the phos- 

 phoric acid of phosiihate rock available for plant use." 



The effects of the ensilage process on the solubility and metabolism of 

 floats, E. B. Forbes (Jour. Indus, and Engin. Chem., 6 (1914), ^o. 7, p. 605). — 

 This is a reply to the criticisms by Mooers in the article noted above. 



The effects of the ensilage process on the solubility and metabolism of 

 floats, C. A. MooEKS (Jour. Indus, and Engin. Chem., 6 (1914), No. 8, p. 695). — 

 A further discussion of this subject. 



Potash (Mich. Geol. and Biol. Survey Pub. 13, Geol. Ser. 10 (1913), pp. 93- 

 96). — The possibility of the discovery of potash salts associated with Michigan 

 brines is briefly discussed. While the limited evidence so far collected is 

 largely negative, the conclusion that there is no possibility of potash salts being 

 found within the limits of the State is not considered warranted. Some of the 

 difficulties and possibilities of drilling for potash salts are pointed out. 



The lime factor theory, O. Loew (Die Lehre vom Kalkfaktor. Berlin, 1914, 

 pp. 31. fig. 1). — Investigations bearing on this subject are critically reviewed. 



The question of sulphur in agriculture, E. Mii;GE (Rev. 8ci. [Paris], 52 



(1914), I, No. 25, pp. 778-784)- — Investigations on this subject are reviewed in 



relation to their bearing on the direct and indirect action of sulphur on the 



growth of plants, but attention is called particularly to a theory explaining the 



64822°— No. 7—14 3 



