32 EXPERIMENT STATION RECORD. 



I i h,- calcareous soils, represented by 53 analyses, are very fertile and less 

 tenacious than the preceding. 



-mis of the Oxford formation, represented by 90 analyses, arc Btrong, rich, 

 ( layej ca Icareons soils. 



(6) Ferruginous clays and sands, represented by 230 analyses, arc very poor soils, 

 extremely deficient in lime and phosphoric acid. 



On the determination of the available constituents of the soil, ('. V. Garola 

 < .-. Congrea Tnternat. Chim. Appl., 1896, Tl,pp. 143-150).— Determinations of the potash 

 and phosphoric acid iii fertilized and unfertilized soils soluble in strong nitric acid 

 I LOO CC. of nitric acid 1.1 sp. gr. and 50 cc. water to each 50 gm. soil), 2 per cent 

 citric acid, and nitric acid of the same acidity (0.013 per cent of hydrogen) as the 

 average found by Dyer in the juice of plant roots. 1 



The relation between the amounts of phosphoric acid soluble in these different 

 reagents and the productiveness of the soil, as well as the influence of applications 

 of different phosphates upon the amount and availability of the phosphoric acid of 

 the soil, are discussed. 



FERTILIZERS. 



On Wiborgh phosphate, its manufacture and agricultural value, 

 L. F. Nilson (7v. Landt. AJcad. Hdndl. Tidskr., 37 (1898), No. 1, pp. 

 49-63). — This new fertilizer, which promises to become of the highest 

 agricultural importance, is manufactured by a process invented by 

 J. Wiborgh, of the Technological Institute of Stockholm (Sweden). 

 Briefly stated, the phosphate is prepared by fusing a thorough mixture 

 of finely comminuted mineral phosphates, like apatite, and feldspar, 

 with powdered sodium carbonate at a temperature of from 100 to 

 1,000° C. The reaction which takes place has been studied in a series 

 of experiments by the author, and is expressed by the following 

 formulas: 



CaFl 3 . itCaO. 3P 2 6 +3Na 2 0. C<) J = 2Na.-0. lOCaO. 3P 2 O s +2NaFl+3C0 2 . K,0. Al.o,.. 

 6SiO>+2Na -O. C0 2 =K 2 0. 2Na,0. AW),. 6SiO,+2CO,. 



The composition of the resulting product is shown by the following 

 analysis: Phosphoric acid 27.01, silica 9.99, sulphuric acid (SO.,) 0.27, 

 potassium oxid 1.54, sodium oxid 11.09, calcium oxid .'18.12, magnesium 

 ox id 2.88, iron and aluminum oxids 4.5, and fluorin (and errors of 

 analysis) 1 per cent. 



The Wiborgh phosphate maybe easily ground to an exceedingly fine 

 powder of linionite color. It dissolves in hydrochloric acid without 

 residue, and is but slightly soluble in water even at higher tempera- 

 tures. It is easily soluble in ammonium citrate solution, its percentage 

 solubility being on the average 95 per cent, having been determined 

 by Scandinavian and German chemists at from 93 to 90 per cent. The 

 citrate solubility of the phosphate increases with the proportion of 

 sodium carbonate used in fusing the apatite, up to the theoretical 

 amount required for the reaction to take place, which is about 30 parts 

 of sodium carbonate per 100 parts of apatite, the latter containing 

 about 17 parts of feldspar. 



'.Tour. Chem. Soc. j London], 1894, p. 115; Chem. News, 69 (1894), p. 113 (E. S. R. 

 5, p. 1013). 



